Search results for "PTFE"
showing 10 items of 11 documents
Ultrasonic Welding of PBT-GF30 (70% Polybutylene Terephthalate + 30% Fiber Glass) and Expanded Polytetrafluoroethylene (e-PTFE)
2021
The ultrasonic welding of polymeric materials is one of the methods often used in practice. However, each couple of material subjected to ultrasonic welding is characterized by different values of technological parameters. Therefore, the main objective of the research presented in this paper is to optimize the parameters for the ultrasonic welding of two materials, namely PBT-GF30 (70% polybutylene terephthalate + 30% fiber glass) and expanded polytetrafluoroethylene (e-PTFE). In this sense, the research was carried out considering a plate-type part made of PBT-GF30, which had a thickness of 2.1 mm, and a membrane-type part made of e-PTFE, with a thickness of 0.3 mm. The condition imposed o…
Time-kill assays of amphotericin B plus anidulafungin against Candida tropicalis biofilms formed on two different biomaterials.
2017
Purpose: To determine the fungicidal activity by time-killing assays of amphotericin B (AMB) combined with anidulafungin (ANF) against biofilms of 2 clinical isolates of Candida tropicalis and the reference strain ATCC® 750, developed on polytetrafluoroethylene (PTFE) and titanium, using the CDC Biofilm Reactor (CBR) as an in vitro model. Methods: Biofilms were developed for 24 hours on the disk surfaces and then exposed to AMB (40 mg/L), ANF (8 mg/L), alone and combined. At predetermined time points after drug exposure, biofilms were removed from the disk surface by vortexing-sonication to quantify viable biofilm cells. Results: Drug activity was dependent on strain and time. After exposur…
E-PTFE (Gore-Tex) implant with or without low-dosage mitomycin-C as an adjuvant in penetrating glaucoma surgery: 2 year randomized clinical trial.
2008
Purpose: To test the expanded polytetrafluoroethylene (ePTFE) as a new adjuvant in trabeculectomy. Methods: Consecutive glaucoma surgical inpatients were observed at the Department of Ophthalmology of Palermo University. Sixty patients (60 eyes) were randomly assigned to undergo trabeculectomy (T), trabeculectomy with mitomycin-C (TMMC), with ePTFE (TG) or with mitomycin-C and ePTFE (TGMMC). Postoperative visits were scheduled at 24 hr, 7 days, 1, 3, 6, 12, 18 and 24 months. Complete success and qualified success were assessed at two target intraocular pressure (IOP) levels – £21 and £17 mmHg – by Kaplan–Meier curves. Results: The postoperative IOP reduction was significant (P < 0.01) at th…
ePTFE ‐based biomedical devices: An overview of surgical efficiency
2021
International audience; Polytetrafluoroethylene (PTFE) is a ubiquitous material used for implants and medical devices in general because of its high biocompatibility and inertness: blood vessel, heart, table jawbone, nose, eyes, or abdominal wall can benefit from its properties in case of disease or injury. Its expanded version, ePTFE is an improved version of PTFE with better mechanical properties, which extends its medical applications. A material as frequently used as ePTFE with these exceptional properties deserves a review of its main uses, developments, and possibility of improvements. In this systematic review, we examined clinical trials related to ePTFE-based medical devices from t…
Resource or waste? A perspective of plastics degradation in soil with a focus on end-of-life options.
2018
‘Capable-of-being-shaped’ synthetic compounds are prevailing today over horn, bone, leather, wood, stone, metal, glass, or ceramic in products that were previously left to natural materials. Plastic is, in fact, economical, simple, adaptable, and waterproof. Also, it is durable and resilient to natural degradation (although microbial species capable of degrading plastics do exist). In becoming a waste, plastic accumulation adversely affects ecosystems. The majority of plastic debris pollutes waters, accumulating in oceans. And, the behaviour and the quantity of plastic, which has become waste, are rather well documented in the water, in fact. This review collects existing information on pla…
Use of tailored intraperitoneal ePTFE dual mesh in permagna inguinal hernia
2012
Here we report a case of a giant inguinoscrotal hernia in an elderly patients treated by means of an open positioning of intraperitoneal ePTFE dual mesh. In patients with giant inguinoscrotal hernia the forceful introduction of viscera in abdominal cavity and primary wall closure is burnened from respiratory complication, abdominal compartment syndrome, and defects in wound healing thus exposing the patients to further morbidity and mortality risk. The management of these patients is difficult because of the high occurrence of morbidity factors that affect the success on intervention independently of the technique of surgical repair. The tension- free technique we adopted consented us to ob…
USO DELLA PROTESI INTRAPERITONEALE IN PTFE IN UN GRANDE LAPAROCELE DOPO TRAPIANTO RENALE : CASE REPORT
2008
Introduzione Il caso riguarda il trattamento chirurgico con l’utilizzo di protesi intraperitoneale dual mash PTFE di un laparocele in un paziente di 55 aa sottoposto a precedente trapianto di rene. Tale complicanza derivava da un urinoma per la necrosi massiva dell’uretrere distale del graft; per cui il pz. è stato sottoposto a reintervento in 2 giornata post trapianto con ricostruzione del piano del muscolo aponeurotico. A circa un mese dal trapianto comparsa di tumefazione in sede incisionale, che rapidamente si è evoluta fino a raggiungere le caratteristiche del grande laparocele.Gli esami strumentali evidenziavano la presenza dell’omento e del piccolo intestino nel sacco erniario. Mater…
USE OF INTRAPERITONEAL PTFE DUAL-MESH IN A GIANT INCISIONAL HERNIA AFTER RENAL TRANSPLANTATION: A CASE REPORT
2008
Objectives: We evaluated the incidence of incisional hernia after kidney transplantation, predisposing factors and the results of surgical repair of a giant incisional hernia by intraperitoneal PTFE dual mesh. Patients and methods: We report our experience about an incisional hernia in a 55 years male after renal transplantation treated with an intraperitoneal dual mesh prosthesis. The cause of incisional hernia was probably due to an urinoma for a total necrosis of distal graft ureter that needed to reopen in 2sd day post transplant with primary fascial approximation. Thirty days after transplantation we discovered a large incisional hernia that rapidly became monstrous with migration of o…
Polytetrafluoroethylene Films in Rigid Polyurethane Foams' Dielectric Permittivity Measurements with a One-Side Access Capacitive Sensor.
2021
As a non-metallic composite material, widely applied in industry, rigid polyurethane (PUR) foams require knowledge of their dielectric properties. In experimental determination of PUR foams’ dielectric properties protection of one-side capacitive sensor’s active area from adverse effects caused by the PUR foams’ test objects has to be ensured. In the given study, the impact of polytetrafluoroethylene (PTFE) films, thickness 0.20 mm and 0.04 mm, in covering or simulated coating the active area of one-side access capacitive sensor’ electrodes on the experimentally determined true dielectric permittivity spectra of rigid PUR foams is estimated. Penetration depth of the low frequency excitation…
A PTFE membrane for the in situ extraction of dissolved gases in natural waters: Theory and applications
2005
A new method for extracting dissolved gases in natural waters has been developed and tested, both in the laboratory and in the field. The sampling device consists of a polytetrafluroethylene (PTFE) tube (waterproof and gas permeable) sealed at one end and connected to a glass sample holder at the other end. The device is pre-evacuated and subsequently dipped in water, where the dissolved gases permeate through the PTFE tube until the pressure inside the system reaches equilibrium. A theoretical model describing the time variation in partial gas pressure inside a sampling device has been elaborated, combining the mass balance and "Solution-Diffusion Model" (which describes the gas permeation…