98%
921
2 minutes
20
A novel method is presented for generating radiation using the beat wave of a bifrequency laser pulse to excite plasma oscillations in a plasma slab that has a density gradient. The plasma wave is localized where it is excited resonantly and becomes a plasma oscillator that produces a beam of radially polarized, terahertz radiation. Particle-in-cell simulations and a theoretical analysis are used to demonstrate its main characteristics, such as its narrow bandwidth. The radiator should have useful applications including driving terahertz-band particle accelerators and for pump-probe experiments.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1103/PhysRevLett.134.015001 | DOI Listing |
J Elect Propuls
September 2025
Department of Aerospace Engineering, Universidad Carlos III de Madrid, Leganés, Spain.
The collisionless cross-field electron transport in an plasma configuration, representative of a Hall thruster, is studied using bispectral analysis on the data of a fully-kinetic simulation. The nonlinear, in-phase interaction of the oscillations of the azimuthal electric field and the electron density, both tied to the fundamental electron cyclotron drift instability (ECDI) mode, is found to be the main driver of electron transport. Higher-wavenumber ECDI modes do not drive anomalous transport directly; however, they are nonlinearly coupled with each other and with the fundamental ECDI mode.
View Article and Find Full Text PDFCirc Res
September 2025
Department of Pediatrics, Child Health Research Center, University of Virginia School of Medicine, Charlottesville. (H.Y., M.Y., D.M., F.X., J.P.S., S.C., L.F.A., S.M., R.A.G., M.L.S.S.-L.).
Background: Juxtaglomerular cells are sensors that control blood pressure and fluid-electrolyte homeostasis. They are arranged as clusters at the tip of each afferent arteriole. In response to decreased blood pressure or extracellular fluid volume, juxtaglomerular cells secrete renin, initiating an enzymatic cascade that culminates in the production of Ang II (angiotensin II), a potent vasoconstrictor that restores blood pressure and fluid-electrolyte homeostasis.
View Article and Find Full Text PDFFish Physiol Biochem
August 2025
The New Zealand Institute for Plant and Food Research Limited, Nelson, 7043, New Zealand.
Promoting swimming in aquaculture has been proposed to enhance fish welfare. This study investigated the effects of 6 h of swimming on stress, immune, metabolic, and antioxidant status of juvenile rainbow trout (Oncorhynchus mykiss). Fish (n = 8) were individually subjected to one of four experimental conditions: minimal water flow (control, < 0.
View Article and Find Full Text PDFRespir Res
August 2025
Department of Pediatrics, University of Utah, Salt Lake City, UT, USA.
Background: AVR-48 is a small molecule that modulates toll-like receptor 4 (TLR4) activity, changing macrophage phenotype from pro- to anti-inflammatory and increasing the anti-inflammatory cytokine IL-10. Treatment with AVR-48 via intraperitoneal injection effectively prevented hyperoxia-induced pathology in a newborn mouse model of bronchopulmonary dysplasia (BPD).
Objective: To evaluate the early and late-stage efficacy of AVR-48 in preventing BPD and associated complications in a mechanically ventilated preterm lamb model that mimics human BPD.
Clin Proteomics
August 2025
Department of Clinical Biochemistry, Copenhagen University Hospital - Bispebjerg, Nielsine Nielsens Vej 4B, Copenhagen, Denmark.
Background: Plasma is the most used clinical specimen, yet diurnal variation in plasma proteins remains largely unexplored. We aimed to identify diurnally-regulated proteins in healthy individuals and assess their potential diagnostic implications, and highlight how diurnal awareness can advance future biomarker research.
Methods: Twenty-four healthy young individuals were studied under highly controlled conditions.