from typing import Dict


def extract_descriptors(descriptor_str: str) -> Dict[str, bool]:
    """
    Convert a string of MeSH descriptors to a dictionary (skip over the labels).
    String has the form (but all on one line):
        D000900 Anti-Bacterial Agents N | D001424 Bacterial Infections N |
        D004352 Drug Resistance, Microbial N | D006801 Humans N |
        D019966 Substance-Related Disorders N
    :param descriptor_str: MeSH descriptors for PubMed abstract
    :return: dictionary mapping MeSH identifier to boolean is this descriptor a
             major topic for this abstract
    """
    retval = {}
    descriptors = descriptor_str.split(' | ')
    for des in descriptors:
        des_parts = des.split()
        retval[des_parts[0]] = des_parts[-1].upper() == 'Y'
    return retval