National Geographic's 100 best images of the year–curated from 106 photographers, 121 stories, and more than two million photographs. Leonardo’s “Mona Lisa” is believed to depict Lisa ...

In general: For men in their 40s and 50s: A PSA score greater than 2.5 ng/ml is considered abnormal. The median PSA for this age range is 0.6 to 0.7 ng/ml. For men in their 60s: A PSA score greater ...