84 research outputs found
Designing & Building a Microwave Plasma Reactor for Graphene Synthesis
Graphene’s remarkable electrical, optical, and chemical properties make it a promising successor to indium tin oxide for applications in flexible, transparent electronics. However, efforts to manufacture graphene have been hindered by inefficient synthesis and transfer methods. Chemical vapor deposition (CVD) is commonly used to produce graphene. CVD starts with a blank surface onto which a chemical vapor is deposited to create a single graphene layer. CVD requires extreme temperatures, so only substrates with high melting points are applicable, like metals. This excludes insulative substrates such as polymers which are essential to transparent and flexible devices. Therefore, a subsequent process transfers the graphene sheet from the metal substrate onto an insulating one. During this transfer, the graphene sheet is usually deformed. On the other hand, microwave plasma chemical vapor deposition (MPCVD) enhances this approach by lowering the process temperature, thereby eliminating the need for substrate transfer. Here, we design and build a custom MPCVD reactor to directly deposit graphene on insulating substrates for applications in flexible, transparent electronics
Calcific Myonecrosis of the Antetibial Area
Calcific myonecrosis is a rare late post-traumatic condition, in which a single muscle is replaced by a fusiform mass with central liquefaction and peripheral calcification. Compartment syndrome is suggested to be the underlying cause. The resulting mass may expand with time due to recurrent intralesional hemorrhage into the chronic calcified mass. A diagnosis may be difficult due to the long time between the original trauma and the symptoms of calcific myonecrosis. We encountered a 53-year-old male patient diagnosed with calcific myonecrosis in the lower leg. We report the case with a review of the relevant literature
Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures
Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo
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