Understanding and controlling the electronic properties of two-dimensional materials are crucial for their potential applications in nano- and optoelectronics. Monolayer transition metal dichalcogenides have garnered significant interest due to their strong light-matter interaction and extreme sensitivity of the band structure to the presence of photogenerated electron-hole pairs. In this study, we investigate the transient electronic structure of monolayer WS on a graphene substrate after resonant excitation of the A-exciton using time- and angle-resolved photoemission spectroscopy.
View Article and Find Full Text PDFIntroduction: Population-level substance use research primarily relies on self-reports, which often underestimate actual use. Hair analyses offer a more objective estimate; however, longitudinal studies examining concordance are lacking. Previous studies showed that specific psychological and behavioral characteristics are associated with a higher likelihood of underreporting substance use, but the longitudinal stability of these associations remains unclear.
View Article and Find Full Text PDFWe performed multiscale simulations of analyte sorption and diffusion in hierarchical porosity models of monolithic silica columns for reversed-phase liquid chromatography to investigate how the mean mesopore size of the chromatographic bed and the analyte-specific interaction with the chromatographic interface influence the analyte diffusivity at various length scales. The reproduced experimental conditions comprised the retention of six analyte compounds of low to moderate solute polarity on a silica-based, endcapped, C stationary phase with water‒acetonitrile and water-methanol mobile phases whose elution strength was varied via the volumetric solvent ratio. Detailed information about the analyte-specific interfacial dynamics received from molecular dynamics simulations was incorporated through appropriate linker schemes into Brownian dynamics diffusion simulations in three hierarchical porosity models received from physical reconstructions of silica monoliths with a mean macropore size of 1.
View Article and Find Full Text PDFWe examined early adolescent predictors of later distress and adaptive coping in early adulthood, using data from a prospective longitudinal cohort study ( = 786). In early adolescence (age 13), we assessed indicators of mental health (internalizing symptoms), stressor exposure (cumulative stressful life events), and family socialization (supportive parent-child interactions). In early adulthood (age 22), during the first COVID-19-related Swiss national lockdown, we assessed cumulative pandemic-related stressors, distress (poor well-being, hopelessness, and perceived disruptions to life) and adaptive coping.
View Article and Find Full Text PDFAdolescent friendships of positive quality promote well-being for decades to come. But what impedes the development of positive friendship quality? The present study examined whether maternal depressive symptoms during early childhood predict children's friendship quality into adolescence, and whether observed negative parenting behavior and children's earlier friendship quality, social skills, and their own depressive symptoms in middle childhood mediate these associations. We used six waves of data from a prospective longitudinal community sample ( = 396).
View Article and Find Full Text PDFAssociations among self-control, substance use (e.g., tobacco and cannabis use), and violence perpetration have been documented during the adolescent years, but the direction of these associations is not well understood.
View Article and Find Full Text PDFSociol Health Illn
January 2025
By focusing on the experiences of employees living with coeliac disease as evidenced in UK employment tribunal cases, this paper interrogates the way practices of exclusion are performed in legal and organisational contexts that purport to promote values of inclusion. In paying attention to how differences are constructed and negotiated, the paper unpacks the way organisational practices mobilise an array of workplace mechanisms to produce complex dynamics of exclusion. Applying Laclau and Mouffe's logics of equivalence and difference, we show how questionable impulses and practices emerge in a workplace environment characterised by unclarity and vagueness.
View Article and Find Full Text PDFThe quantal content of an evoked postsynaptic response is typically determined by dividing it by the average spontaneous miniature response. However, this approach is challenged by the notion that different synaptic vesicle pools might drive spontaneous and evoked release. Here, we "silence" synaptic vesicles through pharmacological alkalinization and subsequently rescue them by optogenetic acidification.
View Article and Find Full Text PDFTransition metal dichalcogenides (TMDs) are quantum confined systems with interesting optoelectronic properties, governed by Coulomb interactions in the monolayer (1L) limit, where strongly bound excitons provide a sensitive probe for many-body interactions. Here, we use two-dimensional electronic spectroscopy (2DES) to investigate many-body interactions and their dynamics in 1L-WS at room temperature and with sub-10 fs time resolution. Our data reveal coherent interactions between the strongly detuned A and B exciton states in 1L-WS.
View Article and Find Full Text PDFEmitter dephasing is one of the key issues in the performance of solid-state single-photon sources. Among the various sources of dephasing, acoustic phonons play a central role in adding decoherence to the single-photon emission. Here, we demonstrate that it is possible to tune and engineer the coherence of photons emitted from a single WSe_{2} monolayer quantum dot via selectively coupling it to a spectral cavity resonance.
View Article and Find Full Text PDFMass transport through the mesopore space of a reversed-phase liquid chromatography (RPLC) column depends on the properties of the chromatographic interface, particularly on the extent of the organic-solvent ditch that favors the analyte surface diffusivity. Through molecular dynamics simulations in cylindrical RPLC mesopore models with pore diameters between 6 and 12 nm we systematically trace the evolution of organic-solvent ditch overlap due to spatial confinement in the mesopore space of RPLC columns for small-molecule separations. Each pore model of a silica-based, endcapped, C-stationary phase is equilibrated with two mobile phases of comparable elution strength, namely 70/30 (v/v) water/acetonitrile and 60/40 (v/v) water/methanol, to consider the influence of the mobile-phase composition on the onset of organic-solvent ditch overlap.
View Article and Find Full Text PDFInt J Parasitol Parasites Wildl
August 2024
Interlayer exciton diffusion is studied in atomically reconstructed MoSe_{2}/WSe_{2} heterobilayers with suppressed disorder. Local atomic registry is confirmed by characteristic optical absorption, circularly polarized photoluminescence, and g-factor measurements. Using transient microscopy we observe propagation properties of interlayer excitons that are independent from trapping at moiré- or disorder-induced local potentials.
View Article and Find Full Text PDFEur Child Adolesc Psychiatry
August 2024
Adolescence is a critical period for early identification and intervention of borderline personality disorder (BPD). Risk-taking and self-harm behaviors (RSB) have been identified as promising early markers of BPD and correlates of depression in school-based samples. The present study aimed, first, to examine the association between RSB and BPD in a clinical sample of adolescents and, second, to examine whether RSB are also linked to depression.
View Article and Find Full Text PDFReversed-phase liquid chromatography (RPLC) operates with water-organic solvent (W-OS) mobile phases where preferential solvation (PS) of solutes is likely. To investigate the relevance of the solute solvation shell in the mobile phase for RPLC retention, we combine data from molecular dynamics simulations of small, neutral solutes (six analytes and two dead time markers) in W-methanol (MeOH) and W-acetonitrile (ACN) mixtures with corresponding retention data obtained on an RPLC column over a wide range of W/OS ratios. Data derived from Kirkwood-Buff integrals show PS by the OS for analytes vs low or negative PS for dead time markers.
View Article and Find Full Text PDFObjective: Epidemiological studies increasingly use hair samples to assess people's cumulative exposure to steroid hormones, but how the use of different psychoactive substances may affect steroid hormone levels in hair is, so far, largely unknown. The current study addresses this gap by establishing the substance exposure correlates of cortisol, cortisone, and testosterone in hair, while also accounting for a number of relevant covariates.
Method: Data came from a large urban community-sample of young adults with a high prevalence of substance use (N = 1002, mean age=20.
Life course epidemiology seeks to understand the intricate relationships between risk factors and health outcomes across different stages of life to inform prevention and intervention strategies to optimize health throughout the lifespan. However, extant evidence has predominantly been based on separate analyses of data from individual birth cohorts or panel studies, which may not be sufficient to unravel the complex interplay of risk and health across different contexts. We highlight the importance of a multi-study perspective that enables researchers to: (a) Compare and contrast findings from different contexts and populations, which can help identify generalizable patterns and context-specific factors; (b) Examine the robustness of associations and the potential for effect modification by factors such as age, sex, and socioeconomic status; and (c) Improve statistical power and precision by pooling data from multiple studies, thereby allowing for the investigation of rare exposures and outcomes.
View Article and Find Full Text PDFUnlabelled: Historic declines in young people's mental health began to emerge before the COVID-19 pandemic. In the face of this youth mental health crisis, the pandemic constituted a naturalistic stressor paradigm that came with the potential to uncover new knowledge for the science of risk and resilience. Surprisingly, approximately 19-35% of people reported better well-being in the first few months of the COVID-19 pandemic than before.
View Article and Find Full Text PDFCorrelated quantum phenomena in one-dimensional (1D) systems that exhibit competing electronic and magnetic order are of strong interest for the study of fundamental interactions and excitations, such as Tomonaga-Luttinger liquids and topological orders and defects with properties completely different from the quasiparticles expected in their higher-dimensional counterparts. However, clean 1D electronic systems are difficult to realize experimentally, particularly for magnetically ordered systems. Here, we show that the van der Waals layered magnetic semiconductor CrSBr behaves like a quasi-1D material embedded in a magnetically ordered environment.
View Article and Find Full Text PDFJ Am Acad Child Adolesc Psychiatry
July 2023
Objective: Large-scale epidemiological research often uses self-reports to determine the prevalence of illicit substance use. Self-reports may suffer from inaccurate reporting but can be verified with objective measures. This study examined the following: the prevalence of illicit and non-medical substance use with self-reports and hair toxicology, the convergence of self-reported and objectively quantified substance use, and the correlates of under- and overreporting.
View Article and Find Full Text PDFOptoelectronic properties of van der Waals homostructures can be selectively engineered by the relative twist angle between layers. Here, we study the twist-dependent moiré coupling in MoSe_{2} homobilayers. For small angles, we find a pronounced redshift of the K-K and Γ-K excitons accompanied by a transition from K-K to Γ-K emission.
View Article and Find Full Text PDFFast transport of retained analytes in reversed-phase liquid chromatography occurs through surface diffusion in the organic-solvent (OS)-enriched interfacial "ditch" region between the hydrophobic stationary phase and the water (W)-OS mobile phase. Through molecular dynamics simulations that recover the OS excess adsorption isotherms of a typical C-stationary phase for methanol and acetonitrile, we explore the relation between OS properties, OS excess adsorption, and surface diffusion. The emerging molecular-level picture attributes the mobile-phase contribution to surface diffusion to the hydrogen-bond capability and the eluting power of the OS.
View Article and Find Full Text PDFObjectives: First, to leverage 15 years of longitudinal data, from child ages 2 to 17, to examine whether maternal depressive symptoms in early and middle childhood and in adolescence predict their child's unhealthy behaviors during adolescence. Second, to examine whether the timing of maternal depressive symptoms or specific unhealthy behaviors matter and whether child depressive symptoms and body mass index explain these associations.
Methods: Data came from a prospective-longitudinal community sample with multi-informant data (N = 213) from child ages 2 to17.