Biodegradable polymer which, edible films have gained more attention due to their environmentally-friendly characteristics, vast variety and availability, non-toxicity, and low cost. Biodegradable polymers have a long history, and since many are natural products, the precise timeline of their discovery and use cannot be accurately traced. One of the first medicinal uses of a biodegradable polymer was the catgut suture, which dates back to at least 100 AD. The first catgut sutures were made from the intestines of sheep, but modern catgut sutures are made from purified collagen extracted from the small intestines of cattle, sheep, or goats. The concept of synthetic
Musical Instrument Museum (Volgograd) more. During his lifetime, Evgeny Nikolayevich was often called "doctor of music". Once he gave a rare instrument "Gavioli" — a mixture of harmonium and Ariston, and the harmony, the flute master could have restored himself, while having no prior instruction or experience of playing the instrument. It was also said that Pushkin could restore a unique instrument from the chips. He both repaired and modified instruments. His excellence and expertise with musical instruments is such that he in order not to wake his home, made a device that helped gently cover the strings to mute the sounds. In 1986,