Turbulence of magnetohydrodynamic waves in nature and in the laboratory is generally cross-helical or nonbalanced, in that the energies of Alfvén waves moving in opposite directions along the guide magnetic field are unequal. Based on high-resolution numerical simulations it is proposed that such turbulence spontaneously generates a condensate of the residual energy E(v) - E(b) at small field-parallel wave numbers. As a result, the energy spectra of Alfvén waves are generally not scale invariant in an inertial interval of limited extent. In the limit of an infinite Reynolds number, the universality is asymptotically restored at large wave numbers, and both spectra attain the scaling E(k) proportional to k(perpendicular)(-2). The generation of a condensate is apparently related to the breakdown of mirror symmetry in nonbalanced turbulence.
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http://dx.doi.org/10.1103/PhysRevLett.103.225001 | DOI Listing |
J Infect Chemother
January 2025
Disease Control and Prevention Center, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo 162-8655, Japan.
Objective: The duration of viral shedding and criteria for de-isolation in the hospital among immunocompromised patients with coronavirus disease 2019 (COVID-19) remain unclear. This study aimed to evaluate viral shedding duration in immunocompromised patients infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2.
Methods: A prospective cohort study was performed at 2 tertiary medical centers in Japan during the Omicron epidemic waves from July 2022 to January 2023.
Arch Gerontol Geriatr
January 2025
Department of Nursing, Harbin Medical University, Daqing, Heilongjiang 163319, China. Electronic address:
Objectives: To investigate the relationship between estimated glucose disposal rates (eGDR) and the progression of frailty, using longitudinal data.
Methods: We analyzed four waves of data from the China Health and Retirement Longitudinal Study (CHARLS) from 2011 to 2018, involving 6,778 middle-aged and older adults. eGDR was calculated using a specific formula, categorizing participants into high and low eGDR groups based on the lowest quartile (8.
Neurotherapeutics
January 2025
Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Chile. Electronic address:
Acute brain injuries (ABIs) encompass a broad spectrum of primary injuries such as ischemia, hypoxia, trauma, and hemorrhage that converge into secondary injury where some mechanisms show common determinants. In this regard, astroglial connexin and pannexin channels have been shown to play an important role. These channels are transmembrane proteins sharing similar topology and form gateways between adjacent cells named gap junctions (GJs) and pores into unopposed membranes named hemichannels (HCs).
View Article and Find Full Text PDFProg Neurobiol
January 2025
Institute of Biomedical Investigations August Pi i Sunyer (IDIBAPS), Systems Neuroscience, 08036 Barcelona, Spain; Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain. Electronic address:
Elucidating human cerebral cortex function is essential for understanding the physiological basis of both healthy and pathological brain states. We obtained extracellular local field potential recordings from cortical slices of neocortical tissue from refractory epilepsy patients. Multi-electrode recordings were combined with histological information, providing a two-dimensional spatiotemporal characterization of human cortical dynamics in control conditions and following modulation of the excitation/inhibition balance.
View Article and Find Full Text PDFUltrason Sonochem
January 2025
School of Engineering Computing and Mathematics, Oxford Brookes University, Oxford, UK; Department of Materials, University of Oxford, Oxford, UK.
This study experimentally investigates the role of cavitation-induced shock waves in initiating and destabilizing capillary (surface) waves on a droplet surface, preceding atomization. Acoustic emissions and interfacial wave dynamics were simultaneously monitored in droplets of different liquids (water, isopropyl alcohol and glycerol), using a calibrated fiber-optic hydrophone and high-speed imaging. Spectral analysis of the hydrophone data revealed distinct subharmonic frequency peaks in the acoustic spectrum correlated with the wavelength of capillary waves, which were optically captured during the onset of atomization from the repetitive imploding bubbles.
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