Surprising torsional barrier reduction in the coupled methyl internal rotations of 2,3-dimethylfuran observed by microwave spectroscopy.

The microwave spectrum of 2,3-dimethylfuran was investigated using a Fourier-transform microwave spectrometer under supersonic expansion. The molecule possesses two inequivalent methyl internal rotors, causing the splitting of each rotational transition into five torsional species. A total of 337 torsional transitions were assigned and fitted in a global fit with the program XIAM, where accurate and physically meaningful geometry and internal rotation parameters could be deduced. The different torsional species were also fitted separately with the program SFLAMS to validate the assignment. Both the global fit and the separate fits achieved standard deviations close to the measurement accuracy. The barriers to internal rotation of the ortho- and meta-methyl rotors, which are in direct proximity, were determined to be 298.274(12) cm-1 and 237.6891(47) cm-1, respectively. These values are radically lower than the respective barriers of 412.9 cm-1 and 380.5 cm-1 found for the steric-free methyl groups in 2-methylfuran and 3-methylfuran. This observation appears to be driven primarily by electrostatic effects rather than being adequately accounted for by steric effects. The experiments were accompanied by quantum chemical calculations. Benchmarking the rotational constants revealed that the MP2/6-31G(d,p) level of theory might be helpful to guide the microwave spectral assignment of methylfuran derivatives.

"Vis-à-Vis Training" to Improve Emotional and Executive Competences in Very Preterm Children: A Pilot Study and Randomised Controlled Trial.

BACKGROUND/OBJECTIVES: Premature birth can lead to socio-emotional, behavioural and executive problems that impact quality of life and school performance in the long term. The aim of this pilot study was to evaluate the feasibility and efficacy of a 12-week computerised training called Vis-à-vis to enhance these competencies in a cohort of very preterm (VPT) children aged 6 to 9. METHODS: This pilot randomised controlled trial included 45 children born before 32 gestational weeks. Socio-emotional, behavioural and executive competencies were evaluated at three time points using computerised tasks, neuropsychological tests and questionnaires. RESULTS: Among the eligible VPT children, 20% (n = 45) accepted to be part of the study, and 40% (n = 18) dropped out. Finally, 60% (n = 27) of the enrolled participants completed the study. Results showed a significant improvement in emotion knowledge and recognition immediately after the completion of the training. CONCLUSIONS: Overall, our results indicate that the implementation of this type of computerised training is feasible, but the overall compliance is unsatisfactory given the high dropout rate. Nevertheless, the positive effect of the training on emotion recognition encourages further exploration of these kinds of interventions to prevent adverse consequences in children born too soon.

Coupled internal rotations and 14N quadrupole hyperfine structure of 2,4-dimethylpyrrole investigated by microwave spectroscopy and quantum chemistry.

The microwave spectrum of 2,4-dimethylpyrrole was investigated using a Fourier-transform microwave spectrometer in a supersonic expansion. Torsional splittings arising from two inequivalent methyl internal rotors in combination with hyperfine splittings due to the nuclear quadrupole coupling of the 14N nucleus were observed. The experiments were accompanied by quantum chemical calculations. A total of 1561 rotational lines were assigned and fitted in global fits using the programs XIAM and BELGI-Cs-2Tops-hyperfine, both achieved the measurement accuracy of 4 kHz. Local separate fits were also performed to verify the correctness of the assignment. Accurate experimental molecular and internal rotation parameters could be deduced and compared to the calculated ones. The barrier to internal rotation of the 2-methyl rotor was determined to be 277.830(26) cm-1, essentially the same as the value of about 280 cm-1 found for 2-methylpyrrole but lower than the value of 317 cm-1 found for 2,5-dimethylpyrrole. The torsional barrier value of the 4-methyl rotor is 262.210(27) cm-1, slightly higher than the value of 246 cm-1 found for 3-methylpyrrole. Benchmarking the rotational constants for 2,4- and 2,5-dimethylpyrrole revealed that the MP2/6-31G(d,p) level could be helpful to guide the assignment of microwave spectra of pyrrole derivatives.

A global rho-axis method for fitting asymmetric tops with one methyl internal rotor and two 14N nuclei: Application of BELGI-2N to the microwave spectra of four methylimidazole isomers.

A number of internal rotation codes can deal with the combination of one or two internal rotors with one 14N quadrupole nucleus, but once it comes to two 14N nuclei, no such code is available even for the case of one internal rotor. We present here the extension of our internal rotor program called BELGI-2N using the rho-axis method global approach to deal with compounds containing one methyl rotor and two weakly coupling 14N nuclei. To test our new code, we applied it to the microwave data recorded for N-methylimidazole, 2-methylimidazole, 4-methylimidazole, and 5-methylimidazole using a chirped-pulse Fourier transform microwave spectrometer in the 7.0-18.5 GHz frequency range. Compared to the previously published study, BELGI-2N was able to (i) significantly increase the number of assigned and fitted lines, (ii) fit the complete datasets considering both the internal rotation and the 14N nuclear quadrupole coupling effects simultaneously, and (iii) achieve standard deviations within the measurement accuracy for all methylimidazole isomers.

Amygdala volumes and associations with socio-emotional competencies in preterm youth: cross-sectional and longitudinal data.

BACKGROUND: Socio-emotional difficulties often result from very preterm (VPT) birth. The amygdala's developmental trajectory, including its nuclei, has been recognized as a significant factor in observed difficulties. This study aims to assess the relationship between amygdala volume and socio-emotional competencies in VPT children and adolescents. METHODS: Socio-emotional competencies were assessed, and amygdala volumes, including subnuclei, were extracted automatically from structural scans in a cross-sectional cohort of VPT (n = 75) and full-term (FT, n = 41) aged 6-14 years. Group differences in amygdala volumes were assessed using ANCOVA, and associations with socio-emotional competencies were studied using partial least squares correlation (PLSC). In a VPT subgroup, additional longitudinal data with amygdala volumes at term-equivalent age (TEA) were manually extracted, growth rates calculated, and associations with school-age socio-emotional competencies investigated using PLSC. RESULTS: Using cross-sectional data at school-age, amygdala volumes displayed comparable developmental patterns between the VPT and the FT groups. Greater volumes were associated with more emotional regulation difficulties in VPT and lower affect recognition competencies in FT. In the longitudinal VPT subgroup, no significant associations were found between amygdala volume trajectory and socio-emotional competencies. CONCLUSION: Although our findings suggest typical amygdala development after VPT birth, further research is necessary to elucidate the developmental trajectory of amygdala and the role of resilience factors. IMPACT: In our cohort, amygdala volumes, including subnuclei, displayed comparable developmental trajectories between the very preterm and the full-term groups. Higher amygdala volumes at school-age were associated with higher emotional regulation difficulties in the very-preterm born group, and with lower affect recognition abilities in full-term born children and adolescents. In a subgroup of very-preterm children and adolescents followed from birth to school-age, no significant associations were found between amygdala volumes at term-equivalent age and socio-emotional competencies at school-age.

Impact of a mindfulness-based intervention on neurobehavioral functioning and its association with large-scale brain networks in preterm young adolescents.

AIM: Adolescents born very preterm (VPT; <32 weeks of gestation) face an elevated risk of executive, behavioral, and socioemotional difficulties. Evidence suggests beneficial effects of mindfulness-based intervention (MBI) on these abilities. This study seeks to investigate the association between the effects of MBI on executive, behavioral, and socioemotional functioning and reliable changes in large-scale brain networks dynamics during rest in VPT young adolescents who completed an 8-week MBI program. METHODS: Neurobehavioral assessments and resting-state functional magnetic resonance imaging were performed before and after MBI in 32 VPT young adolescents. Neurobehavioral abilities in VPT participants were compared with full-term controls. In the VPT group, dynamic functional connectivity was extracted by using the innovation-driven coactivation patterns framework. The reliable change index was used to quantify change after MBI. A multivariate data-driven approach was used to explore associations between MBI-related changes on neurobehavioral measures and temporal brain dynamics. RESULTS: Compared with term-born controls, VPT adolescents showed reduced executive and socioemotional functioning before MBI. After MBI, a significant improvement was observed for all measures that were previously reduced in the VPT group. The increase in executive functioning, only, was associated with reliable changes in the duration of activation of large-scale brain networks, including frontolimbic, amygdala-hippocampus, dorsolateral prefrontal, and visual networks. CONCLUSION: The improvement in executive functioning after an MBI was associated with reliable changes in large-scale brain network dynamics during rest. These changes encompassed frontolimbic, amygdala-hippocampus, dorsolateral prefrontal, and visual networks that are related to different executive processes including self-regulation, attentional control, and attentional awareness of relevant sensory stimuli.

The Heavy Atom Structure, "cis effect" on Methyl Internal Rotation, and 14N Nuclear Quadrupole Coupling of 1-Cyanopropene from Quantum Chemical and Microwave Spectroscopic Analysis.

The microwave spectrum of 1-cyanopropene (crotonitrile) was remeasured using two pulsed molecular jet Fourier transform microwave spectrometers operating from 2.0 to 40.0 GHz. The molecule exists in two isomer forms, E and Z, with respect to the orientation between the methyl and the cyano groups. The spectrum of the Z isomer is more intense. Due to internal rotation of the methyl group, doublets containing A and E torsional species were found for all rotational transitions. Hyperfine splittings arising from the 14N nuclear quadrupole coupling were resolved. The heavy atom structure of the Z isomer was determined by observation of 13C and 15N isotopologue spectra in natural abundances. The experimental results were supported by quantum chemistry. The complex spectral patterns were analyzed and fitted globally, and the barriers to methyl internal rotation are determined to be 478.325(28) cm-1 and 674.632(76) cm-1 for the Z and E isomers, respectively. The non-bonded intramolecular electrostatic attraction between the methyl group and the 1-cyano substituent overcomes steric hindrance, leading to higher stability of the Z isomer. The consequence is a slight opening of 3.2° of the C(1)-C(2)-C(3) angle and a radical decrease of the methyl torsional barrier in the Z isomer due to steric repulsion.

Low barriers to internal rotation in the microwave spectrum of 2,5-dimethylfluorobenzene.

We investigated the rotational spectrum of 2,5-dimethylfluorobenzene containing coupled large amplitude motions of two methyl groups in the frequency range from 2 to 26.5 GHz using a pulsed molecular jet Fourier transform microwave spectrometer. The internal rotation of two inequivalent methyl groups with low torsional barriers (around 16 and 226 cm-1) causes splittings of all rotational transitions into quintets with separations of up to hundreds of MHz between the torsional components. Spectral analysis and modeling of the observed splittings were performed using the programs XIAM and BELGI-Cs-2Tops, whereby the latter achieved measurement accuracy. The methyl internal rotation can be used to examine the electronic and steric environments around the methyl group because they affect the methyl torsional barrier. Electronic properties play a particularly important role in aromatic molecules in the presence of a π-conjugated double bond system. The experimental results were compared with those of quantum chemistry. Benchmark calculations resulted in the conclusion that the B3LYP-D3BJ/6-311++G(d,p) level of theory can be recommended for predicting rotational constants to guide the microwave spectral assignment of dimethylfluorobenzenes in particular and toluene derivatives in general.

Approaching the free rotor limit: extremely low methyl torsional barrier observed in the microwave spectrum of 2,4-dimethylfluorobenzene.

The microwave spectrum of 2,4-dimethylfluorobenzene was recorded using a molecular jet Fourier transform microwave spectrometer in the frequency range from 2.0 to 26.5 GHz. The spectral assignment and modeling were challenging due to the large tunnelling splittings resulting from the very low barrier to internal rotation of the p-methyl group that approaches the free rotor limit. Internal rotation splittings arising from two inequivalent o- and p-methyl groups were observed, analysed and modelled using the modified version of the XIAM code and the BELGI-Cs-2Tops code, giving a root-mean-square deviation of 549.1 kHz and 4.5 kHz, respectively, for a data set of 885 rotational lines. The torsional barriers of the o- and p-methyl groups were determined to be 227.039(51) cm-1 and 3.23(40) cm-1, respectively. The V3 barrier observed for the p-methyl group is lower than in any other para-methyl substituted toluene derivatives with coupled internal rotations, becoming the lowest value ever observed to date. The barrier to internal rotation of the o-methyl group next to a fluorine atom is consistently around 220 cm-1, as confirmed by comparing it to barriers observed in other toluene derivatives. The experimental rotational constants were compared to those obtained by quantum chemical calculations.

Self-Regulation of Attention in Children in a Virtual Classroom Environment: A Feasibility Study.

Attention is a crucial cognitive function that enables us to selectively focus on relevant information from the surrounding world to achieve our goals. Impairments in sustained attention pose challenges, particularly in children with attention deficit hyperactivity disorder, a neurodevelopmental disorder characterized by impulsive and inattentive behavior. While psychostimulant medications are the most effective ADHD treatment, they often yield unwanted side effects, making it crucial to explore non-pharmacological treatments. We propose a groundbreaking protocol that combines electroencephalography-based neurofeedback with virtual reality (VR) as an innovative approach to address attention deficits. By integrating a virtual classroom environment, we aim to enhance the transferability of attentional control skills while simultaneously increasing motivation and interest among children. The present study demonstrates the feasibility of this approach through an initial assessment involving a small group of healthy children, showcasing its potential for future evaluation in ADHD children. Preliminary results indicate high engagement and positive feedback. Pre- and post-protocol assessments via EEG and fMRI recordings suggest changes in attentional function. Further validation is required, but this protocol is a significant advancement in neurofeedback therapy for ADHD. The integration of EEG-NFB and VR presents a novel avenue for enhancing attentional control and addressing behavioral challenges in children with ADHD.

Low Barrier Methyl Internal Rotations and 14N Quadrupole Coupling in the Microwave Spectrum of 2,4-Dimethylthiazole.

The microwave spectrum of 2,4-dimethylthiazole was recorded using a pulsed molecular jet Fourier-transform microwave spectrometer operating in the frequency range from 2.0 to 26.5 GHz. Torsional splittings into quintets were observed for all rotational transitions due to internal rotations of two inequivalent methyl groups. Hyperfine structures arising from the nuclear quadrupole coupling of the 14N nucleus were fully resolved. The microwave spectra were analyzed using the modified version of the XIAM code and the BELGI-Cs-2Tops-hyperfine code. The barriers to methyl internal rotation of the 4- and 2-methyl groups were determined to be 396.707(25) cm-1 and 19.070(58) cm-1, respectively. The very low barrier hindering the 2-methyl torsion was a challenge for the spectral analysis and modeling, and separately fitting the five torsional species together with combination difference loops was the key for a successful assignment. The methyl torsional barriers were compared with those of other thiazole derivatives, showing the influence of the methyl group position on the barrier height. The experimental results were supported by quantum chemical calculations.

Cortical alterations after very preterm birth and the association with socio-emotional abilities from childhood to early adolescence.

Very preterm birth (VPT; <32 weeks' gestation) leads to a situation where crucial steps of brain development occur in an abnormal ex utero environment, translating to vulnerable cortical and subcortical development. Associated with this atypical brain development, children and adolescents born VPT are at a high risk of socio-emotional difficulties. In the current study, we unravel developmental changes in cortical gray matter (GM) concentration in VPT and term-born controls aged 6-14 years, together with their associations with socio-emotional abilities. T1-weighted images were used to estimate signal intensities of brain tissue types in a single voxel (GM, white matter, and cortico-spinal fluid) and extract GM concentration disentangled from the presence of partial volume effects (PVEs). General linear model analysis was used to compare groups. Socio-emotional abilities were assessed and associations with GM concentration were explored using univariate and multivariate analyses. The effects of prematurity were far-reaching, with intricated patterns of increases and decreases of GM concentration mainly in frontal, temporal, parietal, and cingular regions. Better socio-emotional abilities were associated with increased GM concentration in regions known to be involved in such process for both groups. Our findings suggest that the trajectory of brain development following VPT birth may be fundamentally distinctive and impact socio-emotional abilities.

The Microwave Rotational Electric Resonance (RER) Spectrum of Benzothiazole.

The microwave spectra of benzothiazole were measured in the frequency range 2-26.5 GHz using a pulsed molecular jet Fourier transform microwave spectrometer. Hyperfine splittings arising from the quadrupole coupling of the 14N nucleus were fully resolved and analyzed simultaneously with the rotational frequencies. In total, 194 and 92 hyperfine components of the main species and the 34S isotopologue, respectively, were measured and fitted to measurement accuracy using a semi-rigid rotor model supplemented by a Hamiltonian accounting for the 14N nuclear quadrupole coupling effect. Highly accurate rotational constants, centrifugal distortion constants, and 14N nuclear quadrupole coupling constants were deduced. A large number of method and basis set combinations were used to optimize the molecular geometry of benzothiazole, and the calculated rotational constants were compared with the experimentally determined constants in the course of a benchmarking effort. The similar value of the χcc quadrupole coupling constant when compared to other thiazole derivatives indicates only very small changes of the electronic environment at the nitrogen nucleus in these compounds. The small negative inertial defect of -0.056 uÅ2 hints that low-frequency out-of-plane vibrations are present in benzothiazole, similar to the observation for some other planar aromatic molecules.

Revealing Internal Rotation and 14N Nuclear Quadrupole Coupling in the Atmospheric Pollutant 4-Methyl-2-nitrophenol: Interplay of Microwave Spectroscopy and Quantum Chemical Calculations.

The structure and interactions of oxygenated aromatic molecules are of atmospheric interest due to their toxicity and as precursors of aerosols. Here, we present the analysis of 4-methyl-2-nitrophenol (4MNP) using chirped pulse and Fabry-Pérot Fourier transform microwave spectroscopy in combination with quantum chemical calculations. The rotational, centrifugal distortion, and 14N nuclear quadrupole coupling constants of the lowest-energy conformer of 4MNP were determined as well as the barrier to methyl internal rotation. The latter has a value of 106.4456(8) cm-1, significantly larger than those from related molecules with only one hydroxyl or nitro substituent in the same para or meta positions, respectively, as 4MNP. Our results serve as a basis to understand the interactions of 4MNP with atmospheric molecules and the influence of the electronic environment on methyl internal rotation barrier heights.

Simulation and Verification of the Direct Current Electric Field on Fabricating High Porosity f-MWCNTs Thin Films by Electrophoretic Deposition Technique.

Electrophoretic deposition (EPD) is the potential process in high porosity thin films' fabrication or complex surface coating for perovskite photovoltaics. Here, the electrostatic simulation is introduced to optimize the EPD cell design for the cathodic EPD process based on functionalized multiwalled carbon nanotubes (f-MWCNTs). The similarity between the thin film structure and the electric field simulation is evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM) results. The thin-film surface at the edge has a higher roughness (Ra) compared to the center position (16.48 > 10.26 nm). The f-MWCNTs at the edge position tend to be twisted and bent due to the torque of the electric field. The Raman results show that f-MWCNTs with low defect density are more easily to be positively charged and deposited on the ITO surface. The distribution of oxygen and aluminum atoms in the thin film reveals that the aluminum atoms tend to have adsorption/electrostatic attraction to the interlayer defect positions of f-MWCNTs without individually depositing onto the cathode. Finally, this study can reduce the cost and time for the scale-up process by optimizing the input parameters for the complete cathodic electrophoretic deposition process through electric field inspection.

Benchmarking quantum chemical methods for accurate gas-phase structure predictions of carbonyl compounds: the case of ethyl butyrate.

High-resolution spectroscopy techniques play a pivotal role to validate and efficiently benchmark available methods from quantum chemistry. In this work, we analyzed the microwave spectrum of ethyl butyrate within the scope of a systematic investigation to benchmark state-of-the-art exchange-correlation functionals and ab initio methods, to accurately predict the lowest energy conformers of carbonyl compounds in their isolated state. Under experimental conditions, we observed two distinct conformers, one of Cs and one of C1 symmetry. As reported earlier in the cases of some ethyl and methyl alkynoates, structural optimizations of the most abundant conformer that exhibits a C1 symmetry proved extremely challenging for several quantum chemical levels. To probe the sensitivity of different methods and basis sets, we use the identified soft-degree of freedom in proximity to the carbonyl group as an order parameter. The results of our study provide useful insight for spectroscopists to select an adapted method for structure prediction of carbonyl compounds based on their available computational resources, suggesting a reasonable trade-off between accuracy and CPU cost. At the same time, our observations and the resulting sets of highly accurate experimental constants from high-resolution spectroscopy experiments give an appeal to theoretical groups to look further into this seemingly simple family of chemical compounds, which may prove useful for the further development and parametrization of theoretical methods in computational chemistry.

The effect of mindfulness-based intervention on neurobehavioural functioning and its association with white-matter microstructural changes in preterm young adolescents.

Very preterm (VPT) young adolescents are at high risk of executive, behavioural and socio-emotional difficulties. Previous research has shown significant evidence of the benefits of mindfulness-based intervention (MBI) on these abilities. This study aims to assess the association between the effects of MBI on neurobehavioral functioning and changes in white-matter microstructure in VPT young adolescents who completed an 8-week MBI program. Neurobehavioural assessments (i.e., neuropsychological testing, parents- and self-reported questionnaires) and multi-shell diffusion MRI were performed before and after MBI in 32 VPT young adolescents. Combined diffusion tensor imaging (DTI) and neurite orientation dispersion and density imaging (NODDI) measures were extracted on well-defined white matter tracts (TractSeg). A multivariate data-driven approach (partial least squares correlation) was used to explore associations between MBI-related changes on neurobehavioural measures and microstructural changes. The results showed an enhancement of global executive functioning using parent-reported questionnaire after MBI that was associated with a general pattern of increase in fractional anisotropy (FA) and decrease in axonal dispersion (ODI) in white-matter tracts involved in executive processes. Young VPT adolescents with lower gestational age at birth showed the greatest gain in white-matter microstructural changes after MBI.

Corpus callosum structural characteristics in very preterm children and adolescents: Developmental trajectory and relationship to cognitive functioning.

Previous studies suggest that structural alteration of the corpus callosum, i.e., the largest white matter commissural pathway, occurs after a preterm birth in the neonatal period and lasts across development. The present study aims to unravel corpus callosum structural characteristics across childhood and adolescence in very preterm (VPT) individuals, and their associations with general intellectual, executive and socio-emotional functioning. Neuropsychological assessments, T1-weighted and multi-shell diffusion MRI were collected in 79 VPT and 46 full term controls aged 6-14 years. Volumetric, diffusion tensor and neurite orientation dispersion and density imaging (NODDI) measures were extracted on 7 callosal portions using TractSeg. A multivariate data-driven approach (partial least squares correlation) and a cohort-based age normative modelling approach were used to explore associations between callosal characteristics and neuropsychological outcomes. The VPT and a full-term control groups showed similar trends of white-matter maturation over time, i.e., increase FA and reduced ODI, in all callosal segments, that was associated with increase in general intellectual functioning. However, using a cohort-based age-related normative modelling, findings show atypical pattern of callosal development in the VPT group, with reduced callosal maturation over time that was associated with poorer general intellectual and working memory functioning, as well as with lower gestational age.

Large-scale brain network dynamics in very preterm children and relationship with socio-emotional outcomes: an exploratory study.

BACKGROUND: Children born very preterm (VPT; <32 weeks' gestation) are at high risk of neurodevelopmental and behavioural difficulties associated with atypical brain maturation, including socio-emotional difficulties. The analysis of large-scale brain network dynamics during rest allows us to investigate brain functional connectivity and its association with behavioural outcomes. METHODS: Dynamic functional connectivity was extracted by using the innovation-driven co-activation patterns framework in VPT and full-term children aged 6-9 to explore changes in spatial organisation, laterality and temporal dynamics of spontaneous large-scale brain activity (VPT, n = 28; full-term, n = 12). Multivariate analysis was used to explore potential biomarkers for socio-emotional difficulties in VPT children. RESULTS: The spatial organisation of the 13 retrieved functional networks was comparable across groups. Dynamic features and lateralisation of network brain activity were also comparable for all brain networks. Multivariate analysis unveiled group differences in associations between dynamical functional connectivity parameters with socio-emotional abilities. CONCLUSION: In this exploratory study, the group differences observed might reflect reduced degrees of maturation of functional architecture in the VPT group in regard to socio-emotional abilities. Dynamic features of functional connectivity could represent relevant neuroimaging markers and inform on potential mechanisms through which preterm birth leads to neurodevelopmental and behavioural disorders. IMPACT: Spatial organisation of the retrieved resting-state networks was comparable between school-aged very preterm and full-term children. Dynamic features and lateralisation of network brain activity were also comparable across groups. Multivariate pattern analysis revealed different patterns of association between dynamical functional connectivity parameters and socio-emotional abilities in the very preterm and full-term groups. Findings suggest a reduced degree of maturation of the functional architecture in the very preterm group in association with socio-emotional abilities.