Complex sentence: His publications during that time led in later years to allegations that his scientific work had been contaminated by Nazi sympathies: his published writing during the Nazi period included support for Nazi ideas of "racial hygiene" couched in pseudoscientific metaphors.
Split into simpler sentences: His publications during that time led in later years to allegations that his scientific work had been contaminated by Nazi sympathies. His published writing during the Nazi period included support for Nazi ideas of "racial hygiene" couched in pseudoscientific metaphors.