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Purpose: Seizures are often followed by a period of transient neurological dysfunction and postictal alterations in cerebral blood flow may underlie these symptoms. Recent animal studies have shown reduced local cerebral blood flow at the seizure onset zone (SOZ) lasting approximately 1 h following seizures. Using arterial spin labelling (ASL) MRI, we observed postictal hypoperfusion at the SOZ in 75% of patients. The clinical implementation of ASL as a tool to identify the SOZ is hampered by the limited availability of MRI on short notice. Computed tomography perfusion (CTP) also measures blood flow and may circumvent the logistical limitations of MRI. Thus, we aimed to measure the extent of postictal hypoperfusion using CTP. Methods: Fourteen adult patients with refractory focal epilepsy admitted for presurgical evaluation were prospectively recruited and underwent CTP scanning within 80 min of a habitual seizure. Patients also underwent a baseline scan after they were seizure-free for > 24 h. The acquired scans were qualitatively assessed by two reviewers by visual inspection and quantitatively assessed through a subtraction pipeline to identify areas of significant postictal hypoperfusion. Results: Postictal blood flow reductions of > 15 ml/100 g−1/min−1 were seen in 12/13 patients using the quantitative method of analysis. In 10/12 patients, the location of the hypoperfusion was partially or fully concordant with the presumed SOZ. In all patients, additional areas of scattered hypoperfusion were seen in areas corresponding to seizure spread. Conclusion: CTP can reliably measure postictal hypoperfusion which is maximal at the presumed SOZ. [ABSTRACT FROM AUTHOR]

A novel 3 %Ru/CeZrGdO nanocatalyst was synthesized by the wet impregnation method and evaluated for its catalytic activity in dry and steam reforming of methane at atmospheric pressure, seven various temperatures (from 500 to 800 °C) and two different gas hourly space velocity values (7000, 10,500 h). The thermogravimetric diagrams of the used catalysts did not illustrate any carbon deposition on the catalysts applied in both the dry and steam reforming processes and this valuable phenomenon was supported by the scanning electron microscopy images. The low onset reduction temperature in the temperature-programmed reduction profile of the 3 %Ru/CeZrGdO at 183.21 °C reflected much convenient reducibility/oxygen mobility property of the catalyst. Comparing the CH conversions in the dry reforming (92 %) and steam reforming (97 %) reactions using the gas hourly space velocity = 10,500 h at 800 °C indicated higher efficiency of the steam reforming process. The time on stream experiments for the dry and steam reforming reactions exhibited that the CH and CO conversions are almost constant (and even they are slightly increased in the dry reforming) after 30 h reflecting the catalyst outstanding stability with time, absence of coke deposition and catalyst very high activity. [ABSTRACT FROM AUTHOR]