IMPORTANCE Studies examining the association of low to moderate drinking with various cognitive functions have yielded mixed findings. OBJECTIVE To investigate whether associations exist between low to moderate alcohol drinking and cognitive function trajectories or rates of change in cognitive function from middle age to older age among US adults. DESIGN, SETTING, AND PARTICIPANTS A prospective cohort study of participants drawn from the Health and Retirement Study (HRS), a nationally representative sample of US adults, with mean (SD) follow-up of 9.1 (3.1) years. In total, 19 887 participants who had their cognitive functions measured in the HRS starting in 1996 through 2008 and who had participated in at least 3 biennial surveys were included. The data analysis was conducted from June to November 2019. EXPOSURES Alcohol consumption and aging. MAIN OUTCOMES AND MEASURES Trajectories and annual rates of change for the cognitive domains of mental status, word recall, and vocabulary and for the total cognitive score, which was the sum of the mental status and word recall scores. Participants were clustered into 2 cognitive function trajectories for each cognition measure assessed based on their scores at baseline and through at least 3 biennial surveys: a consistently low trajectory (representing low cognitive scores throughout the study period) and a consistently high trajectory (representing high cognitive scores throughout the study period). RESULTS The mean (SD) age of 19 887 participants was 61.8 (10.2) years, and the majority of the HRS participants were women (11 943 [60.1%]) and of white race/ethnicity (16 950 [85.2%]). Low to moderate drinking (<8 drinks per week for women and <15 drinks per week for men) was significantly associated with a consistently high cognitive function trajectory and a lower rate of cognitive decline.

Metal-hydride-catalyzed hydroalkylation of 1,3-dienes with enolizable carbonyl compounds is an atom- and step-economical method for preparing chiral molecules with allylic stereocenters. Although high diastereo- and enantioselectivities have been achieved for many coupling partners, aldehydes have not yet been used for this purpose because they are less stable than other carbonyl compounds under basic conditions and they have the potential to rapidly epimerize at the α-position. Moreover, stereodivergent hydroalkylation reactions of 1,3-dienes to access complementary diastereomers with vicinal stereocenters is challenging. Herein, we describe a synergistic palladium/amine catalyst system that allowed us to achieve the first stereodivergent hydroalkylation reactions of 1,3-dienes with aldehydes. By choosing an appropriate combination of chiral palladium and amine catalysts, we could obtain either syn or anti coupling products, and this method therefore provides highly diastereo- and enantioselective access to complementary diastereomers of chiral aldehydes with α,β-vicinal stereocenters. Density functional theory calculations revealed a mechanism involving PdH formation and migratory insertion into the alkene, followed by C–C bond formation. The origin of the stereoselectivities was investigated by means of distortion/interaction analysis.

To achieve ultrasensitive detection of trace targets through solution-based surface-enhanced Raman spectroscopy (SERS), direct adsorption of the target molecules on a SERS-active surface is vital. In this work, cetyltrimethylammonium bromide (CTAB)-capped gold nano-bipyramids (Au BPs) with different aspect ratios (ARs) are prepared and the surface is successfully modified by a simple ligand exchange method. Cysteamine-capped gold nanobipyramids (cyst-Au BPs) are obtained by means of replacement of CTAB by cysteamine using Au−S covalent bonding and applied in the solution-based SERS detection of different pigment molecules, which always have weak affinity to the gold surface. The hydrogen bonding between the pigment molecule and cysteamine causes the aggregation of Au BPs to generate local electromagnetic field enhancement. The influence of the AR and concentration of Au BPs on SERS properties is investigated. The SERS detection of weak-affinity molecules to an extremely low limit shows that the cyst-Au BPs are highly sensitive compared to CTAB-capped Au BPs. The limit of detection (LOD) of allura red as low as 0.1 ppb and that of sunset yellow as low as 1 ppb show that the proposed strategy has many advantages due to its simplicity and fast and rapid detection for the sensitivity analysis of weak-affinity molecules.

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