{'fraction_non_alphanumeric': 0.01752577319587629, 'fraction_numerical': 0.007216494845360825, 'mean_word_length': 5.5608108108108105, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Vitreous carbon: a new material for middle ear ventilation tubes.

Synthetic allotropic carbons have been used for nearly 20 years as biomedical implants. Vitreous carbons in particular appear to possess very favourable biocompatibility characteristics. The middle ear compatibility of Sigradur has been tested in the mastoid bulla of gerbils. The period of implantation varied from 1 to 13 months. Light and electron-microscopic examination revealed good middle ear tolerance of the material, especially when the surface had not been modelled. Our animal experiments suggest that this material could be suitable for ventilation tubes, but was less ideal for ossicular replacement prostheses, particularly because of the specific surface properties. Consequently, we have used such carbon ventilation tubes in 38 patients. The results obtained using this material were excellent thanks to the favourable biocompatibility, advantageous surface properties, and low weight.