ABSTRACT
@#Arteriovenous malformation (AVM) in children is uncommon occurrence defined as presence of arteriovenous shunting through coiled and tortuous vascular connections. We discussed a case of a 3-year old girl presented with acute left facial asymmetry and right-sided limb weakness. Neurological examination revealed MRC scale of 0 out of 5 for power on her right side. Magnetic Resonance Angiography (MRA) revealed bilateral thalamic AVM. Surgical resection was not advisable in view of deep-seated location. Paediatric AVM most often become apparent following rupture with majority presents with headache. Ruptured paediatric AVM carries high burden of morbidity and mortality. Paediatric intracranial haemorrhage posed tremendous concern regarding its long-term outcome. Treatment would be more appropriate sooner rather than later especially for those presented with ruptured AVM. Surgical resection remains the gold standard treatment for all accessible paediatric AVMs with embolization and radiosurgery as adjunctive therapies. AVM in paediatric population is rare but carries grim prognosis.
ABSTRACT
In this work, the piezoresistive effects of defective graphene used on a flexible pressure sensor are demonstrated. The graphene used was deposited at substrate temperatures of 750, 850 and 1000 °C using the hot-filament thermal chemical vapor deposition method in which the resultant graphene had different defect densities. Incorporation of the graphene as the sensing materials in sensor device showed that a linear variation in the resistance change with the applied gas pressure was obtained in the range of 0 to 50 kPa. The deposition temperature of the graphene deposited on copper foil using this technique was shown to be capable of tuning the sensitivity of the flexible graphene-based pressure sensor. We found that the sensor performance is strongly dominated by the defect density in the graphene, where graphene with the highest defect density deposited at 750 °C exhibited an almost four-fold sensitivity as compared to that deposited at 1000 °C. This effect is believed to have been contributed by the scattering of charge carriers in the graphene networks through various forms such as from the defects in the graphene lattice itself, tunneling between graphene islands, and tunneling between defect-like structures.
