Polymer molecules in a flow undergo a coil-stretch phase transition on an increase of the velocity gradients. Model-independent identification and characterization of the transition in a random flow has been lacking so far. Here we suggest to use the entropy of the extension statistics as a proper measure due to strong fluctuations around the transition. We measure experimentally the entropy as a function of the local Weisenberg number and show that it has a maximum, which identifies and quantifies the transition. We compare the new approach with the traditional one based on the theory using either linear Oldroyd-B or nonlinear finite extensible nonlinear elastic polymer models.
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http://dx.doi.org/10.1103/PhysRevE.103.033107 | DOI Listing |
Domest Anim Endocrinol
January 2025
BIOFITER-IUCA, Universidad de Zaragoza, Facultad de Veterinaria, Miguel Servet 177, 50013 Zaragoza, Spain. Electronic address:
This review presents recent findings on the effect of melatonin on ram spermatozoa. This hormone regulates seasonal reproduction in the ovine species through the hypothalamic-pituitary-gonadal axis, but it also exerts direct effects on spermatogenesis, seminal quality and fertility. In the testis, melatonin stimulates blood flow to this organ, but it also appears to be involved in the differentiation of spermatogonial stem cells and the secretion of testosterone through the MT1 and MT2 receptors.
View Article and Find Full Text PDFJ Neural Eng
January 2025
Department of Neuroscience, Northwestern University, 303 East Chicago Ave, Chicago, Illinois, 60611, UNITED STATES.
Objective: Creating an intracortical brain-computer interface (iBCI) capable of seamless transitions between tasks and contexts would greatly enhance user experience. However, the nonlinearity in neural activity presents challenges to computing a global iBCI decoder. We aimed to develop a method that differs from a globally optimized decoder to address this issue.
View Article and Find Full Text PDFBrain
January 2025
Institute of Neurological Sciences and Psychiatry, Hacettepe University, 06100, Ankara, Turkey.
Cortical spreading depolarization (CSD), the neurophysiological event believed to underlie aura, may trigger migraine headaches through inflammatory signaling that originates in neurons and spreads to the meninges via astrocytes. Increasing evidence from studies on rodents and migraine patients supports this hypothesis. The transition from pro-inflammatory to anti-inflammatory mechanisms is crucial for resolving inflammation.
View Article and Find Full Text PDFJ Phys Chem B
January 2025
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
Reline, which is composed of choline chloride and urea in a molar ratio of 1:2, is the first and most extensively studied deep eutectic solvent (DES). In certain applications, reline is blended with organic solvents, dimethyl sulfoxide (DMSO) in most cases, to gain improved properties. Therefore, it is crucial to have a profound understanding of the impact of DMSO on the dynamics and structures of the species in the binary mixtures.
View Article and Find Full Text PDFInorg Chem
January 2025
Department of Chemistry, University of Patras, Patras 265 04, Greece.
A new [DyBiOCl(saph)] () Werner-type cluster has been prepared, which is the first Dy/Bi polynuclear compound with no metal-metal bond and one of the very few Ln-Bi (Ln = lanthanide) heterometallic complexes reported to date. The molecular compound has been deliberately transformed to its 1-D analogue [DyBiO(N)(saph)] () via the replacement of the terminal Cl ions by end-to-end bridging N groups. The overall metallic skeleton of (and ) can be described as consisting of a diamagnetic {Bi} unit with an elongated trigonal bipyramidal topology, surrounded by a magnetic {Dy} equilateral triangle, which does not contain μ-oxo/hydroxo/alkoxo groups.
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