Improving Printability of Polytetrafluoroethylene (PTFE) with the Help of Plasma Pre-Treatment.

Polytetrafluoroethylene (PTFE) is a potential candidate for the fabrication of flexible electronics devices and electronics with applications in various extreme environments, mainly due to its outstanding chemical and physical properties. However, to date, the utilization of PTFE in printing trials has been limited due to the material's low surface tension and wettability, which do not ensure good adhesion of the printing ink at the level of the substrate. Within this paper, successful printing of PTFE is realized after pre-treating the surface of the substrate with the help of dielectric barrier discharge non-thermal plasma. The efficiency of the pre-treatment is demonstrated with respect to both silver- and carbon-based inks that are commercially available, and finally, the long-lasting pre-treatment effect is demonstrated for periods of time spanning from minutes to days. The experimental results are practically paving the way toward large-scale utilization of PTFE as substrate in fabricating printed electronics in harsh working environments. After 3 s of plasma treatment of the foil, the WCA decreased from approximately 103° to approximately 70°. The resolution of the printed lines of carbon ink was not time dependent and was unmodified, even if the printing was realized within 1 min from the time of applying the pre-treatment or 10 days later. The evaluation of the surface tension (σ) measured with Arcotest Ink Pink showed an increase in σ up to 40 < σ < 42 mN/m for treated Teflon foil and from σ < 30 mN/m corresponding to the untreated substrate. The difference in resolution was distinguishable when increasing the width of the printed lines from 500 µm to 750 µm, but when increasing the width from 750 µm to 1000 µm, the difference was minimal.

Lateral circumflex femoral artery false aneurysm as a complication of intertrochanteric hip fracture with displaced lesser trochanter.

We present a patient who suffered an unstable intertrochanteric hip fracture and underwent osteosynthesis with a trochanteric nail. During the postoperative period, he presented a pseudoaneurysm of the lateral circumflex branch of the deep femoral artery secondary to a displaced fracture of the lesser trochanter. With the suspected diagnosis due to indirect clinical and radiological signs and confirmation by Doppler ultrasound and computed tomography angiography, a transverse arterial embolization with resolution of the symptoms was carried out. The pseudoaneurysm of the deep femoral artery or its branches is a very rare complication after intertrochanteric hip fractures, which must be taken into account in the late appearance of edema and hematoma in the thigh and evidence of medial and superior displacement of the lesser trochanter. The diagnosis is confirmed by CT angiography and the treatment by percutaneous arterial embolization has good results without the need of excising the lesser trochanter.

Intradural disc herniation and epidural gas: something more than a casual association?

STUDY DESIGN: The case of a patient with an intradural disc herniation associated with gas in the spinal canal is presented. OBJECTIVE: To alert spine surgeons to this potential association. SUMMARY OF BACKGROUND DATA: This association was described previously in five patients, a fact that seems surprising given the relative rarity of both intraspinal gas and intradural herniations. METHODS: The case is presented of a female patient with lumbosciatic pain who developed an incomplete cauda equina syndrome. An asymmetric discopathy of the L2-L3 space and a gas bubble with disc material within the spinal canal was noticed in the radiologic explorations. The literature and the authors' experience are reviewed with the aim of confirming the frequency of intradural herniation in association with gas in the spinal canal. RESULTS: A laminoarthrectomy of the involved space was performed followed by direct intradural examination, which revealed a disc fragment that was excised. An instrumented L2-L3 arthrodesis was performed. Postoperative evolution was satisfactory. To date, the authors have found this association in 2% of the patients with intraspinal gas. CONCLUSION: The potential presence of an intradural disc herniation must always be considered when performing an open discectomy on a patient whose CT scan study shows the presence of epidural gas. This association is particularly striking given the relative rarity of intradural herniations and intraspinal gas. In the event that no clear disc herniation was found, an intradural examination may be indicated to justify clinical signs and symptoms or previous radiologic studies.