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The microtubule-associated protein tau gene (MAPT) rs242557 variant is associated with multiple tauopathies and dementia. This study investigated whether it was correlated with brain tau-PET uptake in non-demented elders. Ninety non-demented elders were identified from the Alzheimer's Disease Neuroimaging Initiative cohort. We compared standardized uptake value ratios (SUVRs) of tau-PET tracer 18F-AV-1451 between rs242557 variant carriers and non-carriers in 25 regions of interest (ROIs). The minor allele A was associated with increased hippocampus 18F-AV-1451 uptake in non-demented elders (left: β = 0.111, Bonferroni corrected p = 0.035; right: β = 0.103, Bonferroni corrected p = 0.031). Aβ-positive participants (left: β = 0.206, Bonferroni corrected p = 0.029; right: β = 0.198, Bonferroni corrected p = 0.035) and APOE ε4 non-carriers (left: β = 0.140, Bonferroni corrected p = 0.006; right: β = 0.134, Bonferroni corrected p = 0.004) exhibited approximately the same findings in hippocampus. Considering no obvious associations in other regions, we confirmed the significant correlation of MAPT rs242557 risk variant with increased hippocampus tau deposition in non-demented elders. With higher magnitude signals in the hippocampus that is more likely to be uniquely affected in AD, the tau PET ligand 18F-AV-1451 seemed to possess a specific binding property for AD-like tau pathology.

Background: Recent genetic research identified a protective factor against late-onset Alzheimer's disease (AD) in Caucasians, a variant called rs3747742-C in the TREML2 gene. However, the roles of other TREML2 variants in AD have not been fully explored. Objective: We conducted a focused analysis of 16 TREML2 variants, examining their connection to AD by studying their correlation with cerebrospinal fluid (CSF) proteins, neuroimage, and cognition in the Alzheimer's Disease Neuroimaging Initiative database (ADNI). Methods: A multiple linear regression model was utilized to estimate potential associations between TREML2 genotypes and various endophenotypes in the entire ADNI sample at baseline, with age, gender, years of education, and APOE ɛ4 status included as covariates. To examine changes in clinical outcomes over time, linear mixed-effects models were employed. Results: We found that the SNP rs17328707-A was associated with higher ADNI-VS scores, smaller ventricles, and larger middle temporal volume at baseline. The SNP rs6915083-G was linked to lower CSF t-tau and p-tau levels, and higher CSF Aβ levels. The SNP rs9394766-G was associated with a smaller hippocampus and larger ventricles at baseline. In longitudinal cohorts, the rs6915083-G SNP was associated with changes in ADNI-MEM and ADNI-EF scores, as well as the rate of hippocampal and middle temporal atrophy. Conclusion: Our findings reveal that TREML2 gene variants have different effects on AD. Two variants are protective, while one may be a risk factor. This enhances our understanding of AD genetics and could guide future research and personalized treatments. [ABSTRACT FROM AUTHOR]

The charge migration mechanism across the surface heterojunction constructed on an anatase TiO2 nanocrystal is still under debate. To solve this longstanding question, we present a systematic study of the band edges (vs. standard hydrogen electrode, SHE) of aqueous TiO2 interfaces with anatase (101), (100) and (001) surfaces, using a combination of density functional theory-based molecular dynamics (DFTMD) and efficient computational SHE (cSHE) methods. Our calculations show that the conduction band minimum (CBM) of the (101) surface is lower than that of (001) and (100) surfaces, which is thermodynamically favorable for electrons migrating to the (101) surface through the surface heterojunction, while the hole preferentially accumulates on the (100) surface due to its highest valence band minimum (VBM). In addition, we qualitatively explore the facet-dependent photocatalytic activity of anatase TiO2. Due to the possession of both the beneficial atomic structure (with 100% undercoordinated Ti5c atoms at the surface) and electronic structure (more strongly oxidizing holes in the VBM and efficient electron–hole spatial separation separation), the (001) surface exhibits the most efficient photocatalytic performance for water oxidation. Furthermore, it is confirmed that the use of simplified theoretical models neglecting the detailed atomic structures of water at the aqueous interface is inadequate to predict the band alignment of semiconductors relative to water redox potentials, so that it may result in substantial errors in evaluating the photocatalytic performance of materials to be used for water splitting. [ABSTRACT FROM AUTHOR]

The interaction of water with TiO2 plays an important role in electrochemistry, geochemistry and environmental science. Yet, whether water spontaneously dissociates on a defect-free TiO2 surface is still in dispute. To solve this apparently simple but longstanding question, we present a systematic study of aqueous TiO2 interfaces with low-index stoichiometric anatase (101), (001) and (100) surfaces, using a combination of density functional theory based molecular dynamics (DFTMD) and free energy perturbation (FEP) methods. Our simulations show that on a defect-free (101) surface, molecular adsorption is thermodynamically stable due to the more acidic Ti2OH+ site than the TiOH2 site. In contrast, a mixed molecular-dissociative conformation is adopted on both (001) and (100) surfaces because of the existence of two kinds of Ti2OH+ sites with markedly different pKa values for the (001) surface and the comparable pKa values of TiOH2 and Ti2OH+ sites for the (100) surface, respectively. In addition, an interesting finding is that the pKa values for TiOH2 sites are approximately equal on these three surfaces and thereby we regard that the water adsorption state on anatase TiO2 surfaces is mainly dependent on the acid–base chemistry of the Ti2OH+ site. Kinetic analysis further verified the water adsorption features by the calculations of energy barriers for water dissociation and revealed that it is favorable for water dissociation into a terminal hydroxyl with the help of intermediate water molecules, which act as a water proton relay to reduce strain in the transition state. [ABSTRACT FROM AUTHOR]

The development and utilization of versatile metal–organic framework (MOF) materials for fluorescence applications have received the attention of many researchers. In this study, we constructed a versatile luminescent Cl-decorated CPM-5 (CPM-5-Cl) by employing InCl3 and H3BTC in a DMF/H2O/HCl solvent system. The as-synthesized CPM-5-Cl was characterized using PXRD, SEM, EDX mapping, and TGA–DTG. Interestingly, CPM-5-Cl exhibited not only excellent thermal and water stability but also unique solid-state fluorescence emission performance. The CIE coordinate and luminescence photo under UV light indicated CPM-5-Cl as a promising candidate for blue light-emitting diodes. Furthermore, as a ratiometric thermometer, CPM-5-Cl exhibited highly sensitive temperature sensing over a wide temperature range (80–300 K), and the maximum relative sensitivity of CPM-5-Cl reached 3.08% K−1 at 300 K. Moreover, CPM-5-Cl exhibited high selectivity for Fe3+ detection with low detection limits (2.25 × 10−4 M) in aqueous solution. It was tested for anti-interference properties, recyclability, and the mechanism of Fe3+ sensing. Our research provides new opportunities for the design and synthesis of versatile fluorescent In-MOFs. [ABSTRACT FROM AUTHOR]