The study will investigate the biomarkers of Aβ and Tau seeds in plasma detected by Alzheimer's disease (AD) related seeds quantitative detector (AD-seeds-detector), and their sensitivity and specificity in diagnosing AD, compared with those from age-matched cognitively normal controls, and those with other types of dementia. To perform a high throughput analysis of the amount of Aβ and Tau seeds, the investigators have developed an AD-seeds-detector, in which a fluorescence microplate reader was combined with an oscillating mixer or water-bath-type ultrasonicator