Exotic orbits due to spin-spin coupling around Kerr black holes

We report exotic orbital phenomena of spinning test particles orbiting around a Kerr black hole, i.e., some orbits of spinning particles are asymmetrical about the equatorial plane. When a nonspinning test particle orbits around a Kerr black hole in a strong field region, due to relativistic orbital precessions, the pattern of trajectories is symmetrical about the equatorial plane of the Kerr black hole. However, the patterns of the spinning particles' orbit are no longer symmetrical about the equatorial plane for some orbital configurations and large spins. We argue that these asymmetrical patterns come from the spin-spin interactions between spinning particles and Kerr black holes, because the directions of spin-spin forces can be arbitrary, and distribute asymmetrically about the equatorial plane.Comment: 15 pages, 20 figure

Neuroprotective effects of α-lipoic acid against hypoxic– ischemic brain injury in neonatal rats

Purpose: To explore the neuroprotective efficacy of α-lipoic acid (ALA) against hypoxic-ischemic encephalopathy (HIE) in neonatal rats.Methods: Forty-eight rats (P7-pups) were randomly assigned to one of four groups: group I received saline; group II (HI) underwent unilateral carotid artery ligation and hypoxia (92 % N2 and 8 % O2) for 2.5 h; and groups III and IV (ALA 50 and 100) were treated with 50 or 100 mg ALA/kg for 7 days prior to against hypoxic-ischemic (HI) insult. Cerebral antioxidant status, edema, and the levels of inflammatory markers were determined.Results: ALA administration substantially (p < 0.01) attenuated both cerebral infarct area and degree of edema while decreasing the levels of several inflammatory markers (TNF-α, NF-p65, IL-1β, IL-6). In addition, in the ALA groups, antioxidant enzyme (SOD, CAT, GSH) activities were significantly elevated,while the expressions of TNF-α and IL-1β protein were significantly (p < 0.01) down-regulated.Conclusion: The neuroprotective efficacy of ALA in HIE can be attributed to its suppression of both oxidative stress and the levels of inflammatory markers.Keywords: Hypoxic–ischemic brain injury, α-Lipoic acid, Cerebral infarct area, Edema, Antioxidants, Inflammatory marker