Researchers find the proton conductivity of jelly found in the Ampullae of Lorenzini of sharks and skates to be unusually high.

A chitin nanofiber-silk biomimetic nanocomposite with enhanced mechanical properties is self-assembled from solution to yield ultrafine chitin nanofibers embedded in a silk matrix.

We demonstrate ultrastrong and flexible hydrogels by self-assembling chitin nanofiber in the presence of gelatin methacryloyl. We tune the mechanical properties of the hydrogel with chitin nanofiber content and show proof-of-concept applications in engineering vascular tissue.

Engineered tissues require enhanced organization of cells and extracellular matrix (ECM) for proper function. To promote cell organization, substrates with controlled micro- and nanopatterns have been developed as supports for cell growth, and to induce cellular elongation and orientation via contact guidance. Micropatterned ultra-thin biodegradable substrates are desirable for implantation in the host tissue. These substrates, however, need to be mechanically robust to provide substantial support for the generation of new tissues, to be easily retrievable, and to maintain proper handling characteristics. Here, we introduce ultra–thin (<10 μm), self-assembled chitin nanofiber substrates micropatterned with replica molding for engineering cell sheets. These substrates are biodegradable, mechanically strong, yet flexible, and easily manipulated into the desired shape. As a proof-of-concept, fibroblast cell proliferation, elongation, and alignment were studied on the developed substrates with different pattern dimensions. On the optimized substrates, the majority of the cells aligned (<10°) along the major axis of micropatterned features. With the ease of fabrication and mechanical robustness, the substrates presented herein can be utilized as versatile system for the engineering and delivery of ordered tissue in applications such as myocardial repair.

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By modulating the degree of cross-linking, this lightweight composite can be tuned with a range of mechanical properties.

Bioactive glass particles (0.42SiO(2)-0.15CaO-0.23Na(2)O-0.20ZnO) of varying size (<90 μm and 425-850 μm) were synthesized and coated with silver (Ag) to produce Ag coated particles (PAg). These were compared against the uncoated analogous particles (Pcon.). Surface area analysis determined that Ag coating of the glass particles resulted in increased the surface area from 2.90 to 9.12 m(2)/g (90 μm) and 1.09-7.71 m(2)/g (425-850 μm). Scanning electron microscopy determined that the Ag coating remained at the surface and there was little diffusion through the bulk. Antibacterial (Escherichia coli--13 mm and Staphylococcus epidermidis--12 mm) and antifungal testing (Candida albicans--7.7 mm) determined that small Ag-coated glass particles exhibited the largest inhibition zones compared to uncoated particles. pH analysis determined an overall higher pH consider in the smaller particles, where after 24 h the large uncoated and Ag coated particles were 8.27 and 8.74 respectively, while the smaller uncoated and Ag coated particles attained pH values of 9.63 and 9.35 respectively.

5,11,17,26,27,arene (1) has been used for the preparation of a graphite coated thorium ion-selective electrode (Th 4+ -ISE). The plasticized PVC membrane containing 30% PVC, 58% ortho-nitrophenyloctylether (NPOE), 4% sodium tetraphenylborate (NaTPB) and 8% ionophore was directly coated on a graphite rod. This sensor gave good Nernstian responses with a slope of 15.5 ± 0.1 mV/decade over a concentration range of 1´10 -5 -11 0 -3 M of thorium ions with a limit of detection of 7.9´10 -6 M. The dynamic response time of the electrode to achieve a steady potential was found to be about 15 seconds. The potential of the prepared sensor was independent of the pH variation in the range 2.3-4.0. The selectivity relative to several mono-, di-and tri-valent metal ions, i.e. Li + , Na + , K + , Ag + , NH 4 + , Sr 2+ , Mn 2+ , Fe 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , Cd 2+ , La 3+ , Sm 3+ , Dy 3+ , Er 3+ and Y 3+ was examined. This electrode can be used for 6 months without any considerable divergences in the potential response. The sensor was successfully used as an indicator electrode for the potentiometric titration of a thorium solution using a standard solution of EDTA.