No abstract

The Sendai Framework for Disaster Risk Reduction 2015-2030 recognizes the strong connection between health and disasters and promotes the concept of health resilience throughout. Several of the seven global targets stated in the Sendai Framework are directly related to health in terms of reducing disaster mortality, the number of affected people, disaster damage to critical infrastructure, and disruption of basic services such as health facilities. The Sendai Framework also maintains close coordination with other United Nations landmark agreements relevant to health such as the Sustainable Development Goals. However, the measurement of healthrelated indicators is challenging. Issues arise, for example, in linking deaths to disasters because of the complex interplay between exposure, risk, vulnerability, and hazards. The lack of a universal classification of disasters also means that recording of health data in disasters is not standardized. Developing the guidelines to enable data on the indicators to be collected and reported to support the Sendai targets requires detailed thinking, time, and consultation with a diverse range of stakeholders. Strong collaboration and partnership will be vital to achieving success.

The controlled complex coacervation of oppositely charged hyaluronic acid (M ≈ 800-1000 kg mol) and chitosan (M ≈ 160 kg mol, degree of acetylation = 15%) led to hydrogels with controllable properties in terms of elasticity and strength. In this work, we performed desalting by dialysis of high ionic strength solutions of mixed polyelectrolytes and showed that the control of the pH during the polyelectrolyte assembly greatly impacts the mechanical properties of the hydrogel. First, for pHs from 5.5 to 7.5, a slight coacervation was observed due to low chitosan protonation and poor polyelectrolyte associations. Then, for pHs from 3.0 to 5.5, coacervation and syneresis led to free-standing and easy to handle hydrogels. Finally, for pHs from 2.0 to 3.0 (close to the pK of the hyaluronic acid), we observed the unusual stretchability of these hydrogels that could arise from the pre-folding of hyaluronic acid chains while physical crosslinking was achieved by hyaluronic acid/chitosan polyelectrolyte complexation.