Observation of heavy spin-orbit excitons propagating in a nonmagnetic background: The case of (Ba,Sr)2YIrO6

We present a combined experimental and theoretical study of the elementary magnetic excitations in Ba2YIrO6 and Sr2YIrO6 - the two most intensively discussed candidates for a new type of magnetic instability caused by exciton condensation. For both materials, high-resolution resonant inelastic x-ray scattering (RIXS) at the Ir L3 edge reveals sharp excitations around 370 and 650 meV energy loss, which we identify as triplet and quintet spin-orbit excitons. While the momentum-dependent RIXS spectra reveal that both the triplet and the quintet propagate coherently within the nonmagnetic background of the singlet sites, these modes remain fully gapped. The Ir-Ir exchange interactions in both double perovskites are therefore not strong enough to overcome the magnetic gap and, hence, our results exclude an intrinsic magnetic instability due to a condensation of magnetic excitations for both Ba2YIrO6 and Sr2YIrO6

Early Retinal Findings Following Cooling in Neonatal Encephalopathy

BACKGROUND AND AIM:  Perinatal HI (hypoxia-ischemia)-related visual defects including blindness are known to be associated with ischemic lesions in intracerebral visual pathways and ischemic retinal damage (IRD). Intraocular hemorrhages (IOH) such as retinal hemorrhage (RH), which may result from perinatal HI, can cause IRD by various mechanisms. We aimed to evaluate the early retinal findings in neonates with moderate-to-severe neonatal encephalopathy (NE) who underwent TH and its relationship between coagulation status, amplitude-integrated electroencephalography (aEEG) patterns, and magnetic resonance imaging-magnetic resonance spectroscopy (MRI-MRS) findings. METHOD AND PATIENTS:  A total of 31 newborn infants who underwent moderate-to-severe NE and TH included in the study. Coagulation parameters were taken immediately before starting TH, and daily during TH period. aEEG records were obtained during TH and rewarming period.Binocular indirect ophthalmoscopic examination (BIOE) and MRI-MRS scanning were performed when TH protocol completed. RESULTS:  Total 13 (41.9%) patients had abnormal BIOE findings. Ten of them were (77%) IOH, other findings are as follows: RH (n = 7), optic disc hemorrhage (n = 2), and vitreous hemorrhage (n = 1). Initial coagulation status was not related to IOH. Worsened aEEG and MRI-MRS results were not related to BIOE findings. CONCLUSION:  Frequency of IOH is high in newborns with NE who underwent TH being independent from severity of MRS-MRI findings, aEEG pattern, and disturbed coagulation status

Corrosion Behavior of Galvanized Steel Exposed to Fusarium oxysporum f. sp. cumini Isolated from a Natural Biofilm

Fusarium spp. are prevalent fungi in water systems and also in biofilm layers developing upon metal surfaces associated with these systems. The present study investigated (i) the presence of Fusarium sp. in biofilms on galvanized steel surface exposed to potable water, and (ii) the effect of Fusarium sp. on corrosion behaviour of galvanized steel by electrochemical methods. The natural biofilm was formed on the galvanized steel surface in a laboratory-scaled test system. Molecular characterization of the tentative Fusarium isolate was carried out by sequencing of the internal transcribed spacer (ITS) regions. The metal coupons were exposed for 336 h to potato dextrose broth medium inoculated with Fusarium sp. The biofilm formation and corrosion products on the metal surfaces were investigated by scanning electron microscopy. The ITS sequences showed that the Fusarium sp. isolate was closely related to Fusarium oxysporum f. sp. cumini (98.97%). The electrochemical analysis revealed that although the test medium was corrosive for the metal, the presence of F. oxysporum f. sp. cumini accelerated the corrosion of galvanized steel. According to the results, this is the first study showing the presence of Fusarium sp. in the natural biofilm formed on the galvanized steel surface and also the effect of Fusarium sp. on corrosion behavior of the galvanized steel in aqueous environment