Self-healing and self-cleaning clear coating.

Coatings exhibiting both self-cleaning and self-healing properties are envisioned for a wide range of applications. Herein we report a simple fabrication approach toward poly(urea-urethane) (PU) coatings having self-healing and self-cleaning properties. The self-cleaning component is a poly(dimethylsiloxane) (PDMS), which is affordable in cost and also has a lower environmental footprint relative to its fluorinated counterpart. The self-healing properties are imparted by dynamic urea bonds of the matrix. The obtained surfaces are evaluated for their anti-smudge properties such as water-, oil- and ink-repellency, as well as optical properties. The self-healing properties of these coatings are evaluated by making scores with a doctor blade and monitoring the healing under different conditions using optical microscopy. The resultant coatings are also investigated for their good mechanical properties. The surface chemical compositions are determined x-ray photoelectron spectroscopy, while atomic force microscopy is used for microstructural analysis of these coatings.

Thiamine Assays-Advances, Challenges, and Caveats.

Thiamine (vitamin B1) is essential to the health of all living organisms and deficiency has long been associated with diseases in animals such as fish, birds, alligators, and domesticated ruminant mammals. Thiamine is also implicated in several human diseases including Alzheimer's, diabetes, dementia, depression and, most notably, Wernicke-Korsakoff syndrome and Beriberi disease. Yet, highly sensitive and specific detection of thiamine remains an analytical challenge, as pM to nm levels of thiamine need to be detected in environmental and human samples, respectively, various phosphorylated variants need to be discriminated, and rapid on-site detection would be highly desirable. Furthermore, appropriate sample preparation is mandatory, owing to the complexity of the relevant sample matrices including fish tissues, ocean water, and body fluids. This Review has two objectives. First, it provides a thorough overview of analytical techniques published for thiamine detection over the last 15 years. Second, it describes the principles of analytical approaches that are based on biorecognition and may open up new avenues for rapid and high-throughput thiamine analysis. Most notably, periplasmic binding proteins, ribozymes, and aptamers are of particular interest, as they function as bioaffinity recognition elements that can fill an important assay technology gap, owing to the unavailability of thiamine-specific commercial antibodies. Finally, the authors provide brief evaluations of key outcomes of the major assay concepts and suggest how innovative techniques could help develop sensitive and specific thiamine analytical test systems.