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Background: Personality traits have been proposed as risk factors for depressive symptoms. However, the neural mechanism behind these relationships is unclear. This study examined the possible mediating effect of resting-state functional connectivity networks on these relationships. Methods: Data from 153 healthy Germans were obtained from the MPI-Leipzig Mind-Brain-Body: Neuroanatomy & Connectivity Protocol database. Network-based statistics were used to identify significant functional connectivity networks that were positively and negatively associated with the personality traits of neuroticism, conscientiousness, and extraversion, with and without demographical covariates. Mediation analyses were performed for each personality trait and depressive symptoms with the significant positive and negative network strengths of the respective personality traits as mediators. Results: Neuroticism, conscientiousness, and extraversion were significantly correlated with depressive symptoms. Network-based statistics identified patterns of functional connectivity that were significantly associated with neuroticism and conscientiousness. After controlling for demographical covariates, significant conscientiousness-associated and extraversion-associated networks emerged. Mediation analysis concluded that only the neuroticism-positive network mediated the effect of neuroticism on depressive symptoms. When age and sex were controlled, the extraversion-positive network completely mediated the effect of extraversion on depressive symptoms. Conclusions: These findings revealed that patterns of intrinsic functional networks predict personality traits and suggest that the relationship between personality traits and depressive symptoms may in part be due to their common patterns of intrinsic functional networks. [ABSTRACT FROM AUTHOR]

Porphyrin‐based metal‐organic frameworks (MOFs) have received great attention for solar photochemistry applications. Manipulating the direction of energy (exciton) migration plays an essential role in boosting the light‐harvesting efficiency of porphyrin‐based MOFs. Here, based on the time‐dependent exciton‐exciton annihilation rate, an optical control of directional exciton migration is demonstrated in cobalt‐porphyrin surface‐supported MOF nanofilms (Co‐TCPP SURMOFs). Utilizing photocarrier densities or lattice temperature as the control knob, the dynamic form of exciton migration in Co‐TCPP SURMOFs can be switched between the nearest‐neighbor 1D interaction and the quasi‐isotropic 2D interaction, which is well explained using a diffusion model of exciton‐exciton scattering. This results provide an optical approach to regulating exciton migration in MOFs, which enhances understanding of the excitonic behavior in artificial light harvesters. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) nanocrystals are promising for optoelectronic and microelectronic technologies. However, the performance of 2D nanocrystal light-emitting diodes (LEDs) remains limited. Here, exciton dynamics are rationally controlled by both shell engineering and device engineering, obtaining colloidal quantum well LEDs (CQW-LEDs) with superior performance. The formation of CQW films on charge transport layers shows an excellent photoluminescence quantum yield of 76.63%. An unreported relationship among Auger lifetime, electron confinement energy, and external quantum efficiency (EQE) in 2D nanocrystal devices is directly observed. The optimized CQW-LEDs possess a maximum power efficiency of 6.04 lm W−1 and a current efficiency of 9.20 cd A−1, setting record efficiencies for 2D nanocrystal red LEDs. Additionally, a remarkable EQE of 13.43% has been achieved, accompanied by an exceptionally low efficiency roll-off. Significantly, EQE for flexible CQW-LEDs is 42-fold higher than the previous best results. Furthermore, active-matrix CQW-LEDs on printed circuit boards are developed. The findings not only unlock new possibilities for controlling exciton dynamics but also provide an alternative strategy to achieve high-performance 2D nanocrystal based applications. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Patients with Alzheimer's disease present with difficulty in lexical retrieval and reversal of the concreteness effect in nouns. Little is known about the phenomena before the onset of symptoms. We anticipate early linguistic signs in the speech of people who suffer from amnestic mild cognitive impairment (MCI). Here, we report the results of a corpus‐linguistic approach to the early detection of cognitive impairment. METHODS: One hundred forty‐eight English‐speaking Singaporeans provided natural speech data, on topics of their choice; 74 were diagnosed with single‐domain MCI (38 amnestic, 36 non‐amnestic), 74 cognitively healthy. The recordings yield 267,310 words, which are tagged for parts of speech. We calculate the per‐minute word counts and concreteness scores of all tagged words, nouns, and verbs in the dataset. RESULTS: Compared to controls, subjects with amnestic MCI produce fewer but more abstract nouns. Verbs are not affected. DISCUSSION: Slower retrieval of nouns and the reversal of the concreteness effect in nouns are manifested in natural speech and can be detected early through corpus‐based analysis. Highlights: Reversal of the concreteness effect is manifested in patients with Alzheimer's disease (AD) and semantic dementia.The paper reports a corpus‐based analysis of natural speech by people with amnestic and non‐amnestic mild cognitive impairment (MCI) and cognitively healthy controls.People with amnestic MCI produce fewer and more abstract nouns than people with non‐amnestic MCI and healthy controls. Verbs appear to be unaffected.The imageability problem can be detected in natural everyday speech by people with amnestic MCI, which carries a higher risk of conversion to AD. [ABSTRACT FROM AUTHOR]

Background: Cognitive frailty, defined as having both physical frailty and cognitive impairment that does not satisfy the criteria for Major Neurocognitive Disorder, represents an elevated risk for morbidity. Hence, it is crucial to mitigate such risks. Physical activity interventions have been found effective in protecting against physical frailty and cognitive deterioration. This pilot RCT examines if smartwatches and mobile phone applications can help to increase physical activity, thereby improving physical and cognitive outcomes. Methods: Older individuals (n = 60) aged 60 to 85 years old will have their physical activity tracked using a smartwatch. The subjects will be randomized into two arms: one group will receive daily notification prompts if they did not reach the recommended levels of PA; the control group will not receive prompts. Outcome variables of physical activity level, neurocognitive scores, and physical frailty scores will be measured at baseline, T1 (3 months), and T2 (6 months). Sleep quality, levels of motivation, anxiety, and depression will be controlled for in our analyses. We hypothesize that the intervention group will have higher levels of physical activity resulting in improved cognitive and physical outcomes at follow-up. This study was approved by the National University of Singapore's Institutional Review Board on 17 August 2020 (NUS-IRB Ref. No.: H-20-038). Discussion: Wearable sensors technology could prove useful by facilitating self-management in physical activity interventions. The findings of this study can justify the use of technology in physical activity as a preventive measure against cognitive frailty in older adults. This intervention also complements the rapidly rising use of technology, such as smartphones and wearable health devices, in our lives today. Registration details: This study has been retrospectively registered on clinicaltrials.gov on 5th January 2021 (NCT Identifier: NCT04692974), after the first participant was recruited. [ABSTRACT FROM AUTHOR]