Did armor and magic resist lose efficiency this patch?

I have no basis for this assumption, but ever since the patch hit it feels like i'm taking way more damage on all champions i play than i did just half a week ago. Matchups i've played hundreds of times using the exact same builds suddenly become skewed against me (as a tank player) where in the past my items would negate a certain amount of damage, now it's like i take two or three more times damage than before.