in this study, an efficient and facile technique for preparing graphene oxide in suspension and powder forms was presented based on a modification on hummers' method followed by an additional ultrasonic process. the method involved the provision of graphene oxide from graphite by reaction of potassium permanganate and sulfuric acid with stabilizing the medium complex. furthermore, this stu...

Moisture from the breath is a ubiquitous water energy source. The inability to continuously provide molecules limits its application in moisture-induced electricity generation. This study first develops an electricity-sustainable breath-moisture-induced generator (BMIEG) during intermittent exhalations. fabricated by end-to-end connection of two equal asymmetric regional sandwich structural gra...

abdominal aortic coarctation is an extremely rare vascular pathology. its etiology can be congenital or acquired. here we present a case of acquired infrarenal abdominal coarctation in a 66-year-old woman who complained of low back and legs pain. she had no signs of resting lower limb ischemia, with diminished distal pulses and normal blood pressure in upper and lower extremities. magnetic reso...

importance of covalent bonded two-dimensional monolayer nanostructures and also hydrocarbons is undeniably responsible for creation of new fascinating materials like polyphenylene polymer, a hydrocarbon super honeycomb network, so-called porous graphene. the mechanical properties of porous graphene such as its young’s modulus, poisson’s ratio and the bulk modulus as the determinative properties...

direct electron transferring of glucose oxidase was investigated   on reduced graphene and graphene oxide templates. the direct electrochemistry   glucose oxidase on   graphene showed a cyclic voltammograms corresponding to the fad/fadh 2   redox couple with an anodic, cathodic and formal potential of -430, -460 and   -445 mv, respectively in 0.1 m phosphate buffer solution and air saturated   ...

graphene-based nanocomposites are newly emerged materials with a wide range of applications such as in supercapacitors electrode. the high conductivity and ability for passing electric current, makes graphene an appropriate new item to be used in cells. electroactive transition metal oxides, owing fast reversible redox pairs, are used to store electrical charge. furthermore, the graphene/nio na...

BACKGROUND Expandable screws have greater pullout strength than conventional screws. The purpose of this study was to compare the biomechanical stability provided by a new built-in expandable anterior spinal fixation system with that of 2 commonly used anterior fixation systems, the Z-Plate and the Kaneda, in a porcine partial vertebral corpectomy model. METHODS Eighteen porcine thoracolumbar...

OBJECTIVES Several endoscopic techniques have been proposed for the management of post-sphincterotomy bleeding. Lately, self-expandable metal stents deployment has gained popularity especially as a rescue therapy when other endoscopic techniques fail. METHODS-RESULTS We report the case report of a massive post-sphincterotomy bleeding in a patient with a self-expandable metal stent in the bili...

graphene, after its first production in 2004 have received lots of attentions from researchers because of its unique properties. high mobility, high sensitivity, high selectivity and high surface area make graphene excellent choice for bio application. one of promising graphene base device that has amazingly high sensitivity is graphene field-effect transistor (gfet). this review selectively su...

because of production process and constrains conditions, circular graphene sheet may be opposed to structural defect and pin hole, respectively. some of the defects and pin hole on a circular graphene sheet can be considered as an eccentric hole on the sheet. hence, analyzing behavior of circular graphene sheet with an eccentric hole is important. free vibration of an eccentric annular graphene...