Shear-induced structural transitions of a micellar cubic phase during large amplitude oscillatory shear flow is studied with time-resolved oscillatory rheological small angle neutron scattering. This technique allows us to resolve the structural changes within a cycle of oscillation. By applying a strain rate near the critical melting shear rate, melting and recrystallization occurs in a cyclic mode. The maximum degree of order is observed when the shear stress reaches a plateau value during the large amplitude oscillatory shear cycle, whereas melting is maximized at the strain rate wave peaks. This structural evolution confirms the cyclic mechanism of sticking and sliding of 2D hexagonal close-packed layers [I. W. Hamley et al., Phys. Rev. E 58, 7620 (1998)].
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http://dx.doi.org/10.1103/PhysRevLett.108.258301 | DOI Listing |
iScience
January 2025
IRCCS E. Medea Scientific Institute, Epilepsy Unit, 31015 Conegliano (TV), Italy.
Temporal lobe epilepsy (TLE) is characterized by alterations of brain dynamic on a large-scale associated with altered cognitive functioning. Here, we aimed at analyzing dynamic reconfiguration of brain activity, using the neural fingerprint approach, to delineate subject-specific characteristics and their cognitive correlates in TLE. We collected 10 min of resting-state scalp-electroencephalography (EEG, 128 channels), free from epileptiform activity, from 68 TLE patients and 34 controls.
View Article and Find Full Text PDFPsychol Med
January 2025
Department of Radiology, Washington University School of Medicine, St. Louis, MO, USA.
Despite depression being a leading cause of global disability, neuroimaging studies have struggled to identify replicable neural correlates of depression or explain limited variance. This challenge may, in part, stem from the intertwined state (current symptoms; variable) and trait (general propensity; stable) experiences of depression.Here, we sought to disentangle state from trait experiences of depression by leveraging a longitudinal cohort and stratifying individuals into four groups: those in remission ('trait depression group'), those with large longitudinal severity changes in depression symptomatology ('state depression group'), and their respective matched control groups (total analytic = 1030).
View Article and Find Full Text PDFInt J Gynaecol Obstet
January 2025
Department of Obstetrics and Gynaecology, Hamdard Institute of Medical Sciences and Research, Jamia Hamdard, Delhi, India.
Objective: This study compares ambulatory glycemic profile and glycemic variability between pregnant women diagnosed with type 2 diabetes mellitus (T2DM) receiving pharmacotherapy and healthy pregnant women without diabetes and assesses their correlation with fetal outcome.
Method: This was a case-control study involving 60 pregnant women (40 with T2DM and 20 healthy controls) in the third trimester of pregnancy. A flash glucose monitor device was applied over the upper arm to obtain the ambulatory glucose profile.
Nat Commun
January 2025
Department of Chemistry, KAIST, Daejeon, Republic of Korea.
Despite its profound significance, the molecular structural changes near the transition state, driven by the vibronic coupling, have remained largely unexplored, leaving a crucial aspect of chemical reactions shrouded in uncertainty. Herein, the dynamical behavior of the reactive flux on the verge of chemical bond breakage was revealed through the spectroscopic characterization of a large amplitude vibrational motion. Highly excited internal rotor states of S methylamine (CHND) report on the structural change as the molecule approaches the transition state, indicating that the quasi-free internal rotation is strongly coupled to the reaction coordinate as their energies near the maximum of the reaction barrier for the N-D chemical bond predissociation.
View Article and Find Full Text PDFJ Neurosci
January 2025
Neuroscience and Cognitive Science Program, University of Maryland, College Park, Maryland, 20742.
Hearing is an active process in which listeners must detect and identify sounds, segregate and discriminate stimulus features, and extract their behavioral relevance. Adaptive changes in sound detection can emerge rapidly, during sudden shifts in acoustic or environmental context, or more slowly as a result of practice. Although we know that context- and learning-dependent changes in the sensitivity of auditory cortical (ACX) neurons support many aspects of perceptual plasticity, the contribution of subcortical auditory regions to this process is less understood.
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