Atypical Growing Pattern of Superficial Temporal Artery Pseudoaneurysm.

Superficial temporal artery pseudoaneurysm is rare and usually caused by trauma. Pseudoaneurysms have been reported to occur most frequently from 2 to 6 weeks after trauma and they range from 1 to 3 cm in diameter. The authors present a case of a patient with an atypical delayed rapid growing pseudoaneurysm, who had undergone neurosurgery after head trauma 20 years ago.A 72-year-old woman underwent craniotomy and extradural hemorrhage removal through a left temporoparietal incision caused by head trauma after a traffic accident 20 years prior. The mass of less than 1 cm in diameter was incidentally found by magnetic resonance imaging 8 years ago. However, the patient had no symptoms and the pseudoaneurysm was not considered a significant finding. Several weeks ago, the patient recognized a palpable mass by chance. She observed it without any medical evaluation and treatment. However, the size of the mass suddenly increased without the patient undergoing trauma. It presented as a soft, pulsating round mass of about 3 cm in diameter. Under general anesthesia, the mass was removed without problems. It was a round-shaped mass of 2.2 cm × 2.4 cm in diameter. The transverse cross-section evidenced it was filled with blood clots. The biopsy revealed a dilated vascular wall with an organized thrombus and neovascularization, which are characteristic for a thrombosed pseudoaneurysm.Thus, given that a pseudoaneurysm can grow at any time, medical doctors should strongly consider surgical removal as opposed to simple observation.

Facile synthesis of one-dimensional iron-oxide/carbon hybrid nanostructures as electrocatalysts for oxygen reduction reaction in alkaline media.

One-dimensional iron-oxide/carbon hybrid nano tubular structures were synthesized via anodic aluminium oxide (AAO) template method. Highly unform iron oxide nanoparticles and carbon structures were formed simultaneously on the wall surface of the AAO template from an iron-oleate precursor by solventless thermal decomposition method. The 1D iron-oxide/carbon nanostructures were obtained after removing the AAO template. The typical size of the iron oxide nanoparticles was - 6 nm, and the nanoparticles had a crystalline structure of maghemite (γ-Fe2O3), which was determined from the HRTEM and X-ray diffraction (XRD). This nanocrystalline spinel structure could provide more active sites for oxygen reduction reaction (ORR) catalysis due to the higher specific surface area and numerous defects. As an ORR catalyst, the hybrid nanotubes showed higher limiting mass activity (8.8 A/g) and a more positive onset potential (-0.241 V, vs. Hg/HgCl) than iron oxide nanoparticles in alkaline media. This electrocatalytic activity of the nanocomposites is mainly attributed to the synergetic effects of the iron oxide nanoparticles and carbon matrix in the one-dimensional nanostructure.

A chemically activated graphene-encapsulated LiFePO4 composite for high-performance lithium ion batteries.

A composite of modified graphene and LiFePO4 has been developed to improve the speed of charging-discharging and the cycling stability of lithium ion batteries using LiFePO4 as a cathode material. Chemically activated graphene (CA-graphene) has been successfully synthesized via activation by KOH. The as-prepared CA-graphene was mixed with LiFePO4 to prepare the composite. Microscopic observation and nitrogen sorption analysis have revealed the surface morphologies of CA-graphene and the CA-graphene/LiFePO4 composite. Electrochemical properties have also been investigated after assembling coin cells with the CA-graphene/LiFePO4 composite as a cathode active material. Interestingly, the CA-graphene/LiFePO4 composite has exhibited better electrochemical properties than the conventional graphene/LiFePO4 composite as well as bare LiFePO4, including exceptional speed of charging-discharging and excellent cycle stability. That is because the CA-graphene in the composite provides abundant porous channels for the diffusion of lithium ions. Moreover, it acts as a conducting network for easy charge transfer and as a divider, preventing the aggregation of LiFePO4 particles. Owing to these properties of CA-graphene, LiFePO4 could demonstrate enhanced and stably long-lasting electrochemical performance.