On Oxygen Activation at Rutile- and Anatase-TiO2

The rutile form of titanium dioxide (r-TiO2) usually shows a photocatalytic activity lower than that of anatase-TiO2 (a-TiO2). Nevertheless, there are numerous examples of sometimes unexpectedly high activity of r-TiO2. This material may appear to be particularly useful when a noncomplete and selective photocatalytic oxidation of organic substrates is required. On the basis of literature examples and our own studies, we compare the photocatalytic activities of r-TiO2, a-TiO2, and r-TiO2/a-TiO2 composites. Because of a significantly better oxygen adsorption at the surface of r-TiO2 and a lower redox potential of the excited electron, more efficient O2•– production takes place at the surface of rutile. As a consequence, generation of 1O2 (involving O2 reduction and the subsequent oxidation of superoxide) and reduction of H2O2 to OH– and HO• are also favored with this material. Therefore, r-TiO2 can be considered to be a particularly good photocatalyst for activation of molecular oxygen. On the other hand, a-TiO2 appears to be a stronger oxidant. In its presence, efficient HO• generation (the result of water or surface hydroxyl group oxidation) and oxidation of H2O2 to O2•– are observed

Breast Cancer Mortality in the Americas and Australasia over the Period 1980–2017 with Predictions for 2025

Substantial progress has been made in the diagnosis, management, and treatment of breast cancer over the last decades. This has affected mortality rates but has also led to inequality in epidemiological trends between different regions of the world. We extracted death certification data for breast cancer from the World Health Organization database. We analyzed trends in breast cancer mortality in selected countries from America, Asia, and Oceania over the 1980–2017 period and predicted numbers of deaths and rates for 2025. In North America, we observed decreased breast cancer mortality, reaching a rate of about 13/100,000 women in 2017. In Latin American countries, breast cancer mortality rates did not consistently decrease. The highest decreases in mortality were observed in Australia. Mortality trends in Asian countries remained among the lowest globally. We have predicted decreased mortality from breast cancer in 2025 for most of the analyzed countries. The epidemiological situation regarding breast cancer mortality is expected to change in the coming years. Advancements in diagnosis and treatment of breast cancer must be extended in various areas of the world to obtain global control of breast cancer mortality