{'fraction_non_alphanumeric': 0.04896421845574388, 'fraction_numerical': 0.011299435028248588, 'mean_word_length': 5.074285714285714, '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}}
[The ultrastructure and argentophilic properties of the nucleolus organizer and centromeric regions of the chromosomes in early mouse embryogenesis].

The Ag-staining of metaphase chromosomes in one-cell mouse embryos shows that the nucleolus organizer regions (NORs) are Ag-negative, whereas centromeric regions (CRs) are Ag-positive. Starting from 8-16-cell embryos, NORs stained by AgNO3 constantly, CRs remaining argentophobic. On the ultrathin sections of multicell embryos, Ag(+)-NORs differ from the chromosomal arms: they consist of loosely filaments about 6-8 nm in diameter, characterized by a low electron density. On the contrary, at one-cell stage Ag(-)-NORs are not morphologically identified: chromosomal bodies consist of uniform DNP-fibrils about 20 nm in diameter. These data permit to suppose that extended rDNA may form supranucleosomal and nucleosomal DNP-fibrils in the absence of Ag-proteins. The Ag(+)- and Ag(-)-CRs contain 10-20 nm DNP-fibrils mainly, although their density at multicell stages is higher than in one-cell mouse embryos.