Interior-architectured ZnO nanostructure for enhanced electrical conductivity via stepwise fabrication process.

Fabrication of ZnO nanostructure via direct patterning based on sol-gel process has advantages of low-cost, vacuum-free, and rapid process and producibility on flexible or non-uniform substrates. Recently, it has been applied in light-emitting devices and advanced nanopatterning. However, application as an electrically conducting layer processed at low temperature has been limited by its high resistivity due to interior structure. In this paper, we report interior-architecturing of sol-gel-based ZnO nanostructure for the enhanced electrical conductivity. Stepwise fabrication process combining the nanoimprint lithography (NIL) process with an additional growth process was newly applied. Changes in morphology, interior structure, and electrical characteristics of the fabricated ZnO nanolines were analyzed. It was shown that filling structural voids in ZnO nanolines with nanocrystalline ZnO contributed to reducing electrical resistivity. Both rigid and flexible substrates were adopted for the device implementation, and the robustness of ZnO nanostructure on flexible substrate was verified. Interior-architecturing of ZnO nanostructure lends itself well to the tunability of morphological, electrical, and optical characteristics of nanopatterned inorganic materials with the large-area, low-cost, and low-temperature producibility.

Pipeline embolization device for giant internal carotid artery aneurysms: 9-month follow-up results of two cases.

The pipeline™ embolization device (PED) is a braided, tubular, bimetallic endoluminal implant used for occlusion of intracranial aneurysms through flow disruption along the aneurysm neck. The authors report on two cases of giant internal carotid artery aneurysm treated with the PED. In the first case, an aneurysm measuring 26.4 mm was observed at the C3-C4 portion of the left internal carotid artery in a 64-year-old woman who underwent magnetic resonance imaging (MRI) for dizziness and diplopia. In the second case, MRI showed an aneurysm measuring 25 mm at the C4-C5 portion of the right internal carotid artery in a 39-year-old woman with right ptosis and diplopia. Each giant aneurysm was treated with deployment of a PED (3.75 mm diameter/20 mm length and 4.5 mm diameter/25 mm length, respectively). Nine months later, both cases showed complete radiological occlusion of the giant intracranial aneurysm and sac shrinkage. We suggest that use of the PED can be a therapeutic option for giant intracranial aneurysms.

Surgical strategies for ruptured blister-like aneurysms arising from the internal carotid artery: a clinical analysis of 18 consecutive patients.

BACKGROUND: Ruptured blister-like aneurysms arising at non-branching sites of the internal carotid artery (BLICAA's) sometimes cause disaster during aneurysm repair because of their characteristic configurations. Our study was designed to establish the best surgical strategies for such aneurysms. METHOD: Eighteen BLICAA's (0.9% of all treated aneurysms) treated at our institute from January 1994 to July 2006 were retrospectively analysed using the database and imaging studies. We assessed the management outcome with the modified Rankin Scale (mRS). The average follow-up period was 17 months. FINDINGS: Their ages ranged from 30 to 68 years with a mean age of 50. There were 16 females, and two males). The angiographic diameter of the aneurysmal sac sranged from 1.4 to 5 mm with a mean diameter of 2.5 mm. The common origins were dorso-medial (n = 7) or dorsal (n = 6) wall of the ICA. Fifteen patients underwent wrapping with cellulose fabric and clipping. Of the remainder, each underwent direct clipping, suturing, or trapping. The overall outcome was mRS 1 in 11 patients (78.0%), two in three patients, three in one patient, one in one patient, and five in two patients. Intra-operative premature rupture occurred in six patients. There was no rebleeding during the follow-up period. Cerebral infarctions following carotid trapping after premature rupture and stenosis after suturing of perforated carotid wall were causes of mortality. The causes of morbidity included initial brain insult and vasospasm. CONCLUSIONS: The surgeon should be ware of the high risk of premature rupture during dissection of BLICAA's. Wrapping with cellulose fabric (Bemsheet) and holding clipping technique could be chosen as the optimal surgical modality for prevention of rebleeding from these lesions.

Management of intracranial cavernous malformation in pediatric patients.

OBJECTIVE: Cavernous malformations (CMs) are vascular malformations affecting any part of the central nervous system. CMs in the pediatric age group are known to be different from those of adults both in origin and clinical characteristics. In this paper, we report our experience in managing CMs in pediatric patients. MATERIALS AND METHODS: Between January 1994 and December 2006, 33 patients younger than 20 years of age with intracranial CMs were treated with microsurgery or radiosurgery. We retrospectively reviewed the presentation and treatment of these 33 patients (18 boys and 15 girls; average age 11.6 years). RESULTS: The most common symptom at presentation was seizure (19 children, 57.6%). The most common type of CM, classified on the basis of magnetic resonance imaging, was type II (18, 54.5%). The supratentorial compartment was the most frequent location (27, 71.8%), and only six CMs (18.2%) were observed in the infratentorial compartment. Microsurgery was performed on 25 patients (75.8%), and radiosurgery was performed on eight patients (24.2%). The overall post-treatment results were positive. Only two children (6.1%) had persistent presurgical neurological signs, although the treatment ameliorated them. No progression of the preoperative neurological signs or onset of new neurological deficits was seen in any of the patients. In our patient group, the microsurgical removal of CMs resulted in the prevention of recurrent hemorrhage and the control of seizure disorders in all cases. CONCLUSIONS: Our results suggest that pediatric patients with symptomatic CMs should be treated surgically because of the risk of recurrent hemorrhaging and the general benefits of CM removal.

Intravascular ultrasound assessment of patterns of arterial remodeling in the absence of significant reference segment plaque burden in patients with coronary artery disease.

OBJECTIVES: We evaluated the impact of reference vessel segment plaque burden on lesion remodeling. Intravascular ultrasound (IVUS) assessment of lesion remodeling compares lesions to reference segments. However, reference segments are rarely disease-free and, therefore, have also undergone remodeling changes. METHODS: Pre-intervention IVUS was obtained in 274 patients with right coronary artery lesions selected because the right coronary artery has less tapering and fewer side branches than the left anterior descending or left circumflex artery. Standard IVUS definitions were used. Patients were divided according to reference vessel segment plaque burden: group A (minimal reference disease, n = 91), both proximal and distal reference plaque burden <20%; group B (n = 91), either proximal or distal reference plaque burden 20% to 40% but both < or =40%; and group C (n = 92), either proximal or distal reference plaque burden >40%. RESULTS: The remodeling index measured 0.98 +/- 0.16 in group A (range, 0.68 to 1.47), 1.04 +/- 0.18 in group B (range, 0.67 to 1.91), and 1.04 +/- 0.15 in group C (range, 0.74 to 1.70), analysis of variance p = 0.0208 (p = 0.0234 group A vs. group B and p = 0.0012 group A vs. group C, but p = 0.8 group B vs. group C). Positive, intermediate, and negative remodeling were observed in 24 (26%), 24 (26%), and 43 lesions (48%) in group A; 36 (40%), 28 (30%), and 27 lesions (30%) in group B; and 34 (37%), 39 (42%), and 19 lesions (21%) in group C, respectively (p = 0.0022). CONCLUSIONS: Negative remodeling occurs commonly in coronary lesions with minimal reference segment disease. Negative remodeling is not just an "artifact" introduced by comparing lesions to diseased reference segments.

Intravascular ultrasound analysis of nonstented adjacent segments in diffuse in-stent restenosis treated with radiation therapy with a rhenium-188-filled balloon.

The effects of beta-radiation therapy on nonstented adjacent segments in in-stent restenosis have not been sufficiently evaluated. beta-radiation therapy for in-stent restenosis was performed with a (188)Re-MAG(3)-filled balloon. We evaluated the effects of beta-radiation therapy on nonstented adjacent segments in in-stent restenosis by intravascular ultrasound (IVUS) analysis in 50 patients who received radiation therapy vs. 9 control patients. The changes (Delta = follow-up - postintervention) of the external elastic membrane (EEM), the lumen, and other IVUS variables were compared between the segments that received radiation therapy and the control segments. The significant differences between the two groups were as follows: Delta EEM area was 0.3 mm(2) in the radiation vs. -1.0 mm(2) in the control (P = 0.005) and Delta lumen area was 0.2 mm(2) vs. -1.3 mm(2), respectively (P < 0.001). In conclusion, compared with the changes of vessel shrinkage in the control group, significant vessel enlargement occurred in the nonstented adjacent segments that received radiation therapy.