Design of acidochromic dyes for facile preparation of pH sensor layers.

Eight new acidochromic dyes have been synthesised that can be used for optically monitoring pH in the range from 3 to 12. Their corresponding pK(a) values have been both measured and calculated theoretically by means of density functional theory. The synthesis of these new dyes is facile without the need for chromatographic purification. The dyes can be covalently linked to polymers containing hydroxyl functions such as cellulose, polyurethane hydrogel, and hydroxyalkyl methacrylate. The resulting sensor layers exhibit significant colour changes both in the UV and in the visible spectral range.

[Infections caused by piercing and tattoos--a review]. / Infektionen durch Piercing und Tattoos--eine Ubersicht.

Piercing, i.e. perforation of skin or mucous membranes in order to attach mostly metallic jewelery as well as multicolored skin tattooing have become more popular than ever before and a considerable number of (young) people practise these methods of body art which are supposed to increase the individuality. But there is a lot of side effects, among them especially infections. The most important bacteria cultivated from such patients are Staphylococcus aureus, group A streptococci and Pseudomonas aeruginosa. Viruses which can be transmitted by piercing or tattooing are especially hepatitis B virus and hepatitis C virus. Besides local bacterial infections also systemic infections (sepsis, endocarditis) occur. The main aspects of diagnostics, therapy and prevention are discussed.