Metal objects were used for various purposes like in the production, decoration, and painting of metallic coins, kitchenwares, and as structural components from ancient ages to the present. Metal extraction and processing ability became one of the important factors to determine the development level of society. For this reason, repairing and protecting the ancient artifacts buried underground or in an aqueous environment that recovered from the archaeological excavations and historical sites is extremely important to protect the history and cultural heritage of society. Historical artifacts are very fragile against environmental factors after their removal from the dig sites and thus rapid intervention procedures are required. Furthermore, historical artifacts exhibited without an application of a protective coating can easily corrode at an increased rate against atmospheric conditions over time. Therefore, developing new approaches for the preservation of metallic objects of cultural heritage has significant importance. It is necessary to know the type of metal to be processed as the coating to be developed for protection will be determined according to the type of metal. Primarily, metal surfaces must be cleansed from the corroded layer followed by developing and applying a structure able to isolate the metal from the environment in order to prevent corrosion. Various materials such as waxes, oils and greases, polymers, glasses and glassy enamels, metallic, and organic coatings have been used to develop corrosion-resistant coatings. Soluble corrosion inhibitors have also been used, which can promote the spontaneous formation of a protective barrier film on surfaces. The structures to be used in the protection of the ancient artifacts must have specific features:• must not cause a change in color and has to preserve authenticity in visual appearance,• easy to apply,• low cost,• reversibility in some cases, i.e. easy to remove from the surface,• environmentally friendly, non-toxic. In this review, the methods commonly used for the protection of archaeological artifacts are examined and their advantages and disadvantages are stated.
Işıkla aktive olan fotodinamik tedavi (FDT), uzun zamandan beri dermatoloji, kanseroloji, kulak burun boğaz, jinekoloji, gastroenteroloji, üroloji vb. Çeşitli hastalıklar için onaylanmış bir tedavi türüdür. FDT'de kullanılan FS, uygun dalga boyunda ışığı absorblayarak reaktif oksijen türlerini (ROS) oluşturabilen bir maddedir. ROS, hedef hücrelerde mutajenik veya genotoksik etki olmadan sitotoksik etkiler üreterek antimikrobiyal aktivite göstermektedir. Ek olarak, bu süreçte mikroorganizmalar da direnç geliştiremezler. Fotosensitizör maddede bulunan kromofor gruplar spesifik dalga boyundaki ışığa maruz kalmasıyla hücreleri öldürme yeteneğine sahip olan reaktif oksijen türleri (ROS) ve reaktif azot (RNS) gibi zararlı radikallerin üretimi; ışığın dalga boyuna, şiddetine, kullanılan PS'ün miktarına ve çeşidine bağlıdır. Bu araştırmada oluşan bu reaktif türlerin konsantrasyonu çeşitli faktörler ile ayarlanarak vücut dokularına zarar vermeden hasarlı dokuda enfeksiyona neden olabilecek iç ve dış kaynaklı mikroorganizmalardan arındırması öngörülmektedir. Ayrıca fotosensitizör boyar maddenin içerisine sabitlendiği hidrojel yara örtüsünün; yaranın nem dengesini koruması, doku oluşumunu arttırıcı etki göstermesi, yarayı soğutarak acıyı azaltması, gaz geçişini optimum düzeyde tutarak ortam kaynaklı kontaminasyonu engellemesi, matriks sisteminin emici özelliği sayesinde hasarlı doku üzerindeki fazla sıvıyı emerek yaranın daha çabuk iyileşmesine katkı sağlaması gibi fiziksel özelliklere sahip olması hedeflenmiştir.
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