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[Display omitted] • Characterizing the heterogeneity of individual cognitive aging from a mitochondrial perspective. • Comprehensively assessing brain resilience through genetic metrics. • Individuals' levels of brain resilience were comprehensively measured by eight pathological characteristics. • The performance of PRS models could be efficiently improved by incorporating mitochondria-related loci. • Significant implications for the prevention and intervention of Alzheimer's disease. Identification of high-risk people for Alzheimer's disease (AD) is critical for prognosis and early management. Longitudinal epidemiologic studies have observed heterogeneity in the brain and cognitive aging. Brain resilience was described as above-expected cognitive function. The "resilience" framework has been shown to correlate with individual characteristics such as genetic factors and age. Besides, accumulative evidence has confirmed the association of mitochondria with the pathogenesis of AD. However, it is challenging to assess resilience through genetic metrics, in particular incorporating mitochondria-associated loci. In this paper, we first demonstrated that polygenic risk scores (PRS) could characterize individuals' resilience levels. Then, we indicated that mitochondria-associated loci could improve the performance of PRSs, providing more reliable measurements for the prevention and diagnosis of AD. The discovery (N = 1,550) and independent validation samples (N = 2,090) were used to construct nine types of PRSs containing mitochondria-related loci (PRSMT) from both biological and statistical aspects and combined them with known AD risk loci derived from genome-wide association studies (GWAS). Individuals' levels of brain resilience were comprehensively measured by linear regression models using eight pathological characteristics. It was found that PRSs could characterize brain resilience levels (e.g., Pearson correlation test P min = 7.96 × 10 - 9 ). Moreover, the performance of PRS models could be efficiently improved by incorporating a small number of mitochondria-related loci (e.g., Pearson correlation test P improved from 1.41 × 10 - 3 to 6.09 × 10 - 6 ). PRSs' ability to characterize brain resilience was validated. More importantly, by incorporating some mitochondria-related loci, the performance of PRSs in measuring brain resilience could be significantly improved. Our findings imply that mitochondria may play an important role in brain resilience, and targeting mitochondria may open a new door to AD prevention and therapy. [ABSTRACT FROM AUTHOR]

BACKGROUND Diethylenetriaminepentaacetic acid (DTPA) dissolution and reprecipitation (DDARP) method is used frequently to eliminate encapsulated nitrate during barite precipitation. However, the effect of DDARP on barite precipitated from different kinds of natural water is rarely reported, particularly it is not clear whether the DDARP method plays a role in eliminating the effect of organic matter on barite from organic-rich water samples. OBJECTIVES To obtain more accurate sulfate oxygen isotope values, using the modified DDARP method and identify the factors affecting the oxygen isotope values of barite from natural water samples. METHODS Element Analyzer (EA) coupled with Isotope Ratio Mass Spectrometry (IRMS) was used to determine the oxygen isotope values of original and purified barite. RESULTS After purification, oxygen isotope values of high grade barite reagent show little variations, indicating that purification of high grade barite reagent is not needed and it can be directly used as the laboratory standard. However, oxygen isotope values of barite from Yellow River water have large variations from 0.6 to 1.0 with an average of 0.8‰, indicating that it is necessary to purify natural water barite. The differences in oxygen isotope values between original and purified barite from natural water samples vary from -0.4‰ to +1.9‰, and the average differences of oxygen isotope values are 0.7‰, 0.2‰, 0.3‰, -0.3‰, 0.1‰ and 1.4‰ for dissolved detergent, groundwater, river water, sewage, dissolved fertilizer, and rainwater, respectively. The large positive differences of oxygen isotope values (from +0.5‰ to +1.9‰) between original and purified barite is found in rainwater samples due to nitrate encapsulated in barite, which is related to the high molar ratio of nitrate to sulfate in rainwater (from 0.2 to 1.9 with an average of 0.7). The negative differences of oxygen isotope values (from -0.2‰ to 0.4‰) are observed in sewage with respect to the organic matter encapsulated in barite from organic-rich sewage, suggesting that the purification method can remove organic interference. CONCLUSIONS The modified DDARP method works well in eliminating nitrate and organic matter encapsulated in barite. It can be used to purify barite to obtain more accurate oxygen isotope values of sulfate in natural water samples. The proposed method can be used as a standard purification method for water body sulfate oxygen isotope determination.