Chemical Vapor Synthesis of Nonagglomerated Nickel Nanoparticles by In-Flight Coating.

Nickel (Ni) nanoparticles (NPs) prepared through vapor-phase synthesis (VPS) are preferred for multilayer ceramic capacitor electrodes due to their high purity and crystallinity advantages. Agglomerated Ni NPs are usually generated using VPS but are undesirable because they cause various problems such as low packing density and electrical shorts. This study proposes the use of coating-assisted chemical vapor synthesis (CVS) for agglomerate inhibition using NaCl or KCl as a coating agent. We have found that the agglomeration ratio, 34.40%, for conventional CVS, can be reduced to 4.80% in the proposed method by in-flight coating with KCl at 900 °C by image analysis using field-emission scanning electron microscopy. Furthermore, the X-ray diffraction and X-ray fluorescence analyses confirm that the NaCl and KCl coating agent can be removed by washing with distilled water. We believe that this coating process can be used to inhibit the formation of agglomerates during the CVS of Ni NPs.

Immediate CT findings following embolization of cerebral aneurysms: suggestion of blood-brain barrier or vascular permeability change.

INTRODUCTION: Although endovascular techniques are widely used for the treatment of cerebral aneurysms, the immediate postprocedural brain CT findings have not been reported. Therefore, in the present study we assessed the immediate postprocedural brain CT findings following the uneventful coil embolization of cerebral aneurysms. METHODS: Included in the study were 59 patients with 61 cerebral aneurysms after uncomplicated coil embolization. Acute subarachnoid hemorrhage was present with 32 of the 61 aneurysms. All patients underwent a brain CT scan just before and within 2 h after the endovascular treatment. If the postprocedural CT scan revealed any new findings, a follow-up CT scan and/or MRI were performed within 24 h. The variables related to the abnormal CT findings were also evaluated. RESULTS: Among the 61 immediate brain CT scans, 26 (43%) showed abnormal findings, including cortical contrast enhancement (n=21, 34%), subarachnoid contrast enhancement (n=8, 13%), intraventricular contrast enhancement (n=5, 8%), and striatal contrast enhancement (n=2, 3%). Single or mixed CT findings were also seen. None of the 61 aneurysms was associated with new neurological symptoms after endovascular treatment, and all patients made an uneventful recovery. Abnormal findings were more likely to be found with lower body weight and with increased corrected amounts of contrast material and heparin (P<0.05). CONCLUSION: After uneventful endovascular treatment of cerebral aneurysms, the immediate brain CT findings can reveal various patterns of abnormal contrast enhancement. Recognizing the immediate brain CT findings is important, as they can mimic various diseases.

Antegrade recanalization of parent artery in internal trapping of vertebral artery dissecting aneurysm: a case report.

BACKGROUND: We describe a case involving technical success with internal trapping using controllable detachable coils yet antegrade recanalization of the occluded vertebral artery, in the vertebral artery dissecting aneurysm. Possible explanations for the antegrade recanalization of the occluded vertebral artery and lessons from the case are also discussed. CASE DESCRIPTION: A 42-year-old woman with a history of stupor (Hunt and Hess grade III) and right vertebral artery dissecting aneurysm, was admitted to our hospital. Endovascular treatment was performed. The dissecting aneurysm and affected right vertebral artery were both completely occluded, whereas the right PICA was preserved. Nine months after the embolization, follow-up angiography was performed, which revealed recanalization of the occluded right vertebral artery with a normal arterial configuration and antegrade flow into the basilar artery. The recanalized vertebral artery was located just superior and lateral to the deployed coil meshes. It was decided that no further intervention was needed. At the last clinical follow-up 15 months after the initial treatment, the patient was fully recovered. CONCLUSION: Even in the case of technical angiographic success in the endovascular management of a dissecting aneurysm, a prompt follow-up angiography is still crucial. Plus, if the false lumen cannot be separated from the true lumen, treatment with just a stent may not be adequate.