ABSTRACT
Epoxy-based nanocomposites can be ideal electromagnetic interference (EMI)-shielding materials owing to their lightness, chemical inertness, and mechanical durability. However, poor conductivity and brittleness of the epoxy resin are challenges for fast-growing portable and flexible EMI-shielding applications, such as smart wristband, medical cloth, aerospace, and military equipment. In this study, we explored hybrid nanofillers of single-walled carbon nanotubes (SWCNT)/reduced graphene oxide (rGO) as conductive inks and polyester fabrics (PFs) as a substrate for flexible EMI-shielding composites. The highest electrical conductivity and fracture toughness of the SWCNT/rGO/PF/epoxy composites were 30.2 S m-1 and 38.5 MPa m1/2, which are ~ 270 and 65% enhancement over those of the composites without SWCNTs, respectively. Excellent mechanical durability was demonstrated by stable electrical conductivity retention during 1000 cycles of bending test. An EMI-shielding effectiveness of ~ 41 dB in the X-band frequency of 8.2-12.4 GHz with a thickness of 0.6 mm was obtained with an EM absorption-dominant behavior over a 0.7 absorption coefficient. These results are attributed to the hierarchical architecture of the macroscale PF skeleton and nanoscale SWCNT/rGO networks, leading to superior EMI-shielding performance. We believe that this approach provides highly flexible and robust EMI-shielding composites for next-generation wearable electronic devices.
ABSTRACT
PURPOSE: During crossover femoro-femoro-popliteal sequential bypass (CFFPB) surgery in ilio-femoral occlusive disease, proximal anastomosis of the femoro-popliteal bypass is usually performed distal to the distal anastomosis of the crossover femoro-femoral bypass. If not, it is done with a piggyback configuration. Another method is a side-to-side anastomosis. Its benefit is that this is the only anastomosis made. And it is less bulky compared with the piggyback configuration. This study was aimed to investigate the long-term outcome of CFFPB using side-to-side anastomosis. METHODS: From Sep 2006 to Aug 2012, 21 patients who underwent CFFPB using side-to-side anastomosis were enrolled. Externally supported polytetrafluoroethylene graft was used as a conduit in all patients. Patient demographic data and procedure details were investigated. Primary graft patency was calculated using the Kaplan-Meier method. RESULTS: The mean age of patients was 79 years (range, 62-81 years) and males were 17 (81%). Fifteen patients (71%) had critical limb ischemia. Inflow arteries comprised of 16 common femoral artery (CFA), 4 superficial femoral artery (SFA), and 1 deep femoral artery (DFA). Side-to-side anastomosis was performed on the CFA in 11, SFA in 2, and DFA in 8 patients. During the mean follow-up period of 21 months (1-60 months), 8 patients died. The 1-, 3-, and 5-year primary patency rates were 76%, 63%, and 63%. CONCLUSION: Long-term patency of CFFPB using side-to-side anastomosis was acceptable. It can be one of the treatment options for patients with ilio-femoral occlusive disease.
