There is agreement on the usefulness of defining frailty in clinical settings as well as on its main dimensions. However, additional research is needed before an operative definition of frailty can be established.

Introduction 6592 1.1. Historic Perspective 6592 1.2. Achievements in Sol−Gel Technology 6594 2. Sol−Gel Chemistry and Methods for Functional Materials 6595 3. Emerging Applications of Silica-Based Materials 6599 3.1. Materials for Controlled Release 6599 3.1.1. Controlled Release of Fragrances and Aromas 6599 3.1.2. Controlled Release of APIs 6600 3.1.3. Controlled Release of Biocides 6602 3.2. Inks and Coatings 6603 3.3. Catalysis for Fine and Specialty Chemicals 6604 3.4. Nanocomposites 6606 3.4.1. Silica Matrix Nanocomposites 6606 3.4.2. Polymer Matrix Nanocomposites 6609 3.5. Ceramic Membranes 6610 4.

Hydrogen production via photocatalytic water splitting using sunlight has enormous potential in solving the worldwide energy and environmental crisis. The key challenge in this process is to develop efficient photocatalysts which must satisfy several criteria such as high chemical and photochemical stability, effective charge separation and strong sunlight absorption. The combination of different semiconductors to create composite materials offers a promising way to achieve efficient photocatalysts because doing so can improve the charge separation, light absorption and stability of the photocatalysts. In this review article, we summarized the most recent studies on semiconductor composites for hydrogen production under visible light irradiation. After a general introduction about the photocatalysis phenomenon, typical heterojunctions of widely studied heterogeneous semiconductors, including titanium dioxide, cadmium sulfide and graphitic carbon nitride are discussed in detail.

Community-based care can impact favourably on rates of institutionalisation and costs. Comprehensive approaches to program restructuring are necessary, as cost-effectiveness depends on characteristics of the system of care. Expansion of successful programmes to achieve widespread use remains a critical challenge.