Inspired by the mussel byssus adhesiveness, a highly hydrated polymeric structure is designed to combine, for the first time, a set of interesting features for load-bearing purposes. These characteristics include: i) a compressive strength and stiffness in the MPa range, ii) toughness and the ability to recover it upon successive cyclic loading, iii) the ability to quickly self-heal upon rupture, iv) the possibility of administration through minimally invasive techniques, such as by injection, v) the swelling ratio being adjusted to space-filling applications, and vi) cytocompatibility. Owing to these characteristics and the mild conditions employed, the encapsulation of very unstable and sensitive cargoes is possible, highlighting their potential to researchers in the biomedical field for the repair of load-bearing soft tissues, or to be used as an encapsulation platform for a variety of biological applications such as disease models for drug screening and therapies in a more realistic mechanical environment. Moreover, given the simplicity of this methodology and the enhanced mechanical performance, this strategy can be expanded to applications in other fields, such as agriculture and electronics. As such, it is anticipated that the proposed strategy will constitute a new, versatile, and cost-effective tool to produce engineered polymeric structures for both science and technology.

An inexpensive one-pot route to self-healing hydrogels with pH-tunable modulus is presented. Hydrogels were formed by reacting tannic acid, trivalent metal ions and polyallylamine. Below pH 8 the hydrogels were supramolecular while above, covalent cross-linking strengthened the hydrogels. From concentrated mixtures, threads were spun, acting as water sensitive mechanical locks.

Mussel-inspired hydrogels held together by reversible catecholato-metal coordination bonds have recently drawn great attention owing to their attractive self-healing, viscoelastic and adhesive properties together with their pH-responsive nature. A major challenge in these systems is to orchestrate the degree of catechol oxidation that occurs under alkaline conditions in air and has a great impact on the aforementioned properties because it introduces irreversible covalent cross-links to the system, which stiffens the hydrogels but consume catechols needed for self-healing. Herein, we present a catechol-based hydrogel design that allows for the degree of oxidative covalent cross-linking to be controlled. Double cross-linked hydrogels with tunable stiffness are constructed by adding the oxidizable catechol analogue, tannic acid, to an oxidation-resistant hydrogel construct held together by coordination of the dihydroxy functionality of 1-(2'-carboxyethyl)-2-methyl-3-hydroxy-4-pyridinone to trivalent metal ions. By varying the amount of tannic acid, the hydrogel stiffness can be customized to a given application while retaining the self-healing capabilities of the hydrogel's coordination chemical component.

Minimal basis full valence CI calculations of potential curves are reported for more than 300 low-lying states of O2, O+2, and O2+2. A large number of new bound states of O+2 and some metastable states of O2+2 are predicted, and from a comparison with known states of O2 and O+2, predictions are made for the spectroscopic constants of the as yet experimentally unknown states.

Total cross sections for electron capture by H+ (250-600 keV), 4He+ and 4He++ (0.3-2 MeV) incident on atomic and molecular hydrogen have been measured. A directly heated tungsten oven provided an atomic-hydrogen target, and the degree of dissociation of molecular hydrogen and the target-thickness calibration were performed utilizing earlier results reported by Shah and Gilbody.