Sleep health (SH) is considered a key determinant of human physiological and psychological well-being. In line with this, previous studies have found that poor sleep is associated with various ...psychiatric disorders, in particular, with anxiety and depression. Although little is known about the neural mechanisms underlying these associations, recent findings suggest that essential dimensions of SH are associated with altered amygdala reactivity (AR); however, evidence to date is inconsistent and reliant on small sample sizes.
To address this problem, the current preregistered study investigated associations between SH and AR to negative facial expressions in the UK Biobank cohort (25,758 participants). Drawing on a large sample size and consistent data acquisition, 5 dimensions of SH (insomnia symptoms, sleep duration, daytime sleepiness, chronotype, and sleep medication) were examined.
Exploratory analyses revealed that short sleep duration was associated with decreased AR. The remaining SH dimensions and a composite measure of all SH dimensions were not associated with AR.
To our knowledge, this is the largest study to test associations between SH and AR. Habitual short sleep duration may be associated with decreased AR, possibly indicating compensation for impaired prefrontal processes and hampered emotion regulation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The transition-metal complex M o ( P H 3 ) 5 H 2 is known to exist in three possible isomeric forms, including a nonclassical, σ-bound dihydrogen complex and two classical dihydride isomers. As such, ...it has served as a model complex for the energies of conversion between these limiting structural regimes. In the present study, ab initio molecular dynamics computer simulations, combined with enhanced sampling techniques, were utilized to directly assess the degree of motion and isomerization of the dihydrogen/dihydride moieties in this complex. Ligand rotations (for both the H2 unit and the phosphine units) were found to be dominant in the low-temperature (298 K) regime, and the classical thermodynamic distribution showed no probability of thermally accessing dihydride forms, although unrestrained molecular dynamics trajectories showed fleeting configurations outside of the σ–H2 configuration. Simulations at higher temperatures surprisingly revealed new tri-hydride isomers that are energetically competitive with the σ–H2 and cis-/trans-dihydride isomers. Low-energy pathways to hydrogen/hydride transfer and phosphine dissociation were readily accessible, which considerably expands the known isomeric flexibility of this complex.
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IJS, KILJ, NUK, PNG, UL, UM
Photochromic molecules are of great interest as light-driven molecular switches in research fields of material and life sciences. In particular, fast T-type photochromic molecules with half-life ...times of the thermal back reaction (t 1/2) on the order of milliseconds can change not only their color but also their physicochemical properties only under photoirradiation. Herein, we report fast T-type photochromic crystals with the t 1/2 on the order of milliseconds composed of a diarylbenzene by utilizing intramolecular CH–N hydrogen bonding interactions. Our results would lead to novel photoresponsive crystalline materials whose color and physicochemical properties can be modulated only under photoirradiation.
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IJS, KILJ, NUK, PNG, UL, UM
Many chemical methods have been developed to favor a particular product in transformations of compounds that have two or more reactive sites. We explored a different approach to site selectivity ...using vibrational strong coupling (VSC) between a reactant and the vacuum field of a microfluidic optical cavity. Specifically, we studied the reactivity of a compound bearing two possible silyl bond cleavage sites-Si-C and Si-O, respectively-as a function of VSC of three distinct vibrational modes in the dark. The results show that VSC can indeed tilt the reactivity landscape to favor one product over the other. Thermodynamic parameters reveal the presence of a large activation barrier and substantial changes to the activation entropy, confirming the modified chemical landscape under strong coupling.
Both tetrel and pnicogen bonds are known to be induced through σ-/π-holes. This work reports computational and experimental evidence of the carbonyl carbon of acetone hosting a tetrel bond by ...dispersion rather electrostatic forces, for the first time, while phosphorus of POCl3 sustains pnicogen bonding via the σ-hole. Heterodimers of POCl3 with acetone (CH3COCH3) have been isolated within inert gas matrixes of Ar and N2 at 12 K. Characteristic vibrational bands at PO stretching of POCl3 and CO stretching of CH3COCH3 have been obtained in support of the computations. The potential energy surface has been traced computationally using ab initio and density functional methods. CH3COCH3 harboring such a tetrel bond, in itself, is quite intriguing. The interplay of these interactions has been comprehended by the quantum theory of atoms in molecules, natural bond orbital, energy decomposition, electrostatic potential mapping, and noncovalent interaction analyses.
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IJS, KILJ, NUK, PNG, UL, UM
The adsorption forms of NO on Ir n + (n = 3–6) clusters were investigated using infrared multiple photon dissociation (IRMPD) spectroscopy and density functional theory (DFT) calculations. Spectral ...features indicative both for molecular NO adsorption (the NO stretching vibration in the 1800–1900 cm–1 range) and for dissociative NO adsorption (the terminal Ir–O vibration around 940 cm–1) were observed, elucidating the co-existence of molecular and dissociative adsorption of NO. In all calculated structures for molecular adsorption, NO is adsorbed via the N atom on on-top sites. For dissociative adsorption, the O atom adsorbs exclusively on on-top sites (μ1) of the clusters, whereas the N atom is found on either a bridge (μ2) or a hollow (μ3) site. For Ir5 + and Ir6 +, the N atom is also found on the on-top sites. The observed propensity for NO dissociation on Ir n + (n = 3–6) is higher than that for Rh6 +, which can be explained by the higher metal-oxygen bond strengths for iridium.
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IJS, KILJ, NUK, PNG, UL, UM
Recent progress in the gas‐phase activation of methane is discussed. We demonstrate that cluster size, charge state, and ligands crucially affect both the reactivity and selectivity of metal‐mediated ...bond activation processes. We outline the important role that relativistic effects and spin densities play and discuss the paradigm of two‐state reactivity in thermal reactions. State‐of‐the‐art mass‐spectrometry based experiments, in conjunction with electronic structure calculations, permit identification of the elementary steps at a strictly molecular level and thus allow to uncover mechanistic features for four types of reactions: (i) metal‐mediated dehydrogenation of methane, (ii) ligand‐switch processes of the type ML + CH4 → M(CH3) + HL, (iii) hydrogen‐atom ion as the crucial step in the oxidative coupling of methane, and (iv) the mechanism of the challenging CH4→CH3OH conversion.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Intermolecular interactions, stereodynamics, and coupled potential energy surfaces (PESs) all play a significant role in determining the outcomes of molecular collisions. A detailed knowledge of such ...processes is often essential for a proper interpretation of spectroscopic observations. For example, nitric oxide (NO), an important radical in combustion and atmospheric chemistry, is commonly quantified using laser-induced fluorescence on the A 2Σ+ ← X 2Π transition band. However, the electronic quenching of NO (A 2Σ+) with other molecular species provides alternative nonradiative pathways that compete with fluorescence. While the cross sections and rate constants of NO (A 2Σ+) electronic quenching have been experimentally measured for a number of important molecular collision partners, the underlying photochemical mechanisms responsible for the electronic quenching are not well understood. In this paper, we describe the development of high-quality PESs that provide new physical insights into the intermolecular interactions and conical intersections that facilitate the branching between the electronic quenching and scattering of NO (A 2Σ+) with H2, N2, and CO. The PESs are calculated at the EOM-EA-CCSD/d-aug-cc-pVTZ//EOM-EA-CCSD/aug-cc-pVDZ level of theory, an approach that ensures a balanced treatment of the valence and Rydberg electronic states and an accurate description of the open-shell character of NO. Our PESs show that H2 is incapable of electronically quenching NO (A 2Σ+) at low collision energies; instead, the two molecules will likely undergo scattering. The PESs of NO (A 2Σ+) with N2 and CO are highly anisotropic and demonstrate evidence of electron transfer from NO (A 2Σ+) into the lowest unoccupied molecular orbital of the collision partner, that is, the harpoon mechanism. In the case of ON + CO, the PES becomes strongly attractive at longer intermolecular distances and funnels population to a conical intersection between NO (A 2Σ+) + CO and NO (X 2Π) + CO. In contrast, for ON + N2, the conical intersection is preceded by an ∼0.40 eV barrier. Overall, our work shines new light into the impact of coupled PESs on the nonadiabatic dynamics of open-shell systems.
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IJS, KILJ, NUK, PNG, UL, UM
Researchers assert that affective responses to seemingly minor daily events have long-term implications for mental health, yet this phenomenon has rarely been investigated. In the current study, we ...examined how levels of daily negative affect and affective reactivity in response to daily stressors predicted general affective distress and self-reported anxiety and depressive disorders 10 years after they were first assessed. Across eight consecutive evenings, participants (N = 711; age = 25 to 74 years) reported their daily stressors and their daily negative affect. Increased levels of negative affect on nonstressor days were related to general affective distress and symptoms of an affective disorder 10 years later. Heightened affective reactivity to daily stressors predicted greater general affective distress and an increased likelihood of reporting an affective disorder. These findings suggest that the average levels of negative affect that people experience and how they respond to seemingly minor events in their daily lives have long-term implications for their mental health.
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BFBNIB, NMLJ, NUK, OILJ, PNG, SAZU, UKNU, UL, UM, UPUK
Heart rate variability has received growing attention in the depression literature, with several recent meta-analyses indicating that lower resting heart rate variability is associated with ...depression. However, the role of fluctuations in heart rate variability (or reactivity) in response to stress in depression remains less clear. The present review provides a systematic examination of the literature on heart rate variability reactivity to a laboratory-induced stressor task and depression, including 26 studies of reactivity in heart rate variability and clinical depression, remitted (or history of) depression, and subthreshold depression (or symptom-level depression) among adults, adolescents, and children. In addition to reviewing the findings of these studies, methodological considerations and conceptual gaps in the literature are addressed. We conclude by highlighting the importance of investigating the potential transactional relationship between heart rate variability reactivity and depression and possible mechanisms underlying this relationship.
•Blunted reactivity of HRV may be associated with current depression in adults.•Further testing is needed for HRV reactivity among youth and adults with subthreshold and remitted depression.•Studies indicate the importance of contextual factors in the HRV reactivity- depression link.•Further research is needed to examine development, sex and curvilinear patterns.•Transactional Model of HRV Reactivity to Stress and Depression is proposed.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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