Search results for "Tetrafluoroethylene"
showing 10 items of 38 documents
Indoor and outdoor determination of pesticides in air by ion mobility spectrometry.
2016
Abstract The use of ion mobility spectrometry (IMS) has been evaluated as analytical methodology to detect and evaluate the occupational exposure to pesticides. The developed IMS methodology was used, in positive and negative modes, to determine the presence of pesticides in air and to evaluate possible inhalation exposures of workers and users based on active sampling on Teflon membranes and direct thermal desorption IMS. The negative IMS mode was used to determine bensulfuron, clorpyrifos, diniconazole, diuron, flutolanil and imidacloprid, while the positive mode was employed to evaluate formetanate, metalaxyl, metamitrone, metribuzin, paclobutrazol and pirimicarb. The IMS measurements pr…
Polyurethane and PTFE membranes for guided bone regeneration: histopathological and ultrastructural evaluation.
2010
Made available in DSpace on 2013-08-12T18:17:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Made available in DSpace on 2013-09-30T18:35:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:04:24Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T14:04:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Objective: The purpose of this study was to research a membrane material for use in guided bone regeneration. Study design: In this study, 25 male Wistar rats were used to analyze the biocompatibility and degradation process of biomembranes. The morphol…
Deep seroma after incisional hernia repair. Case reports and review of the literature.
2015
Wound-related complications are common after incisional hernia repair with mesh; seroma formation is the most frequent problem. The formation of a deep seroma has been rarely reported in the literature.In one year, September 2012-2013, 136 patients underwent surgery for incisional hernia repair, both elective and urgent.The following complications were observed: one dislocation of polypropylene prosthesis, a massive relapsed seroma and two deep seromas described in this article. A 63- years-old female underwent open incisional hernia repair with an intraperitoneal PTFE patch. She developed recurrent seroma under the mesh drained percutaneously, and finally the prosthesis was removed. A 72- …
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…
Identification of optimal device combinations for the chimney endovascular aneurysm repair technique within the PERICLES registry
2018
Abstract Objective The ideal stent combination for chimney endovascular aneurysm repair remains undetermined. Therefore, we sought to identify optimal aortic and chimney stent combinations that are associated with the best outcomes by analyzing the worldwide collected experience in the PERformance of chImney technique for the treatment of Complex aortic pathoLogiES (PERICLES) registry. Methods The PERICLES registry was reviewed for patients with pararenal aortic disease electively treated from 2008 to 2014. Eleven different aortic devices were identified with three distinct subgroups: group A (n = 224), nitinol/polyester; group B (n = 105), stainless steel/polyester; and group C (n = 69), n…
External polytetrafluoroethylene reinforcement of varicose autologous vein grafts in peripheral bypass surgery produces durable bypass function
2017
Abstract Objective Use of autologous veins as peripheral bypass graft may become critical in the presence of significant varicose degeneration of the harvested vein. External support of such dilated veins with standard polytetrafluoroethylene (PTFE) prostheses was recommended as an option to use these veins for peripheral bypass. A single-center experience with this technique regarding long-term graft function, secondary reinterventions, and potential graft degeneration is presented. Methods Between January 1995 and January 2006, there were 54 patients with varicose veins who underwent 57 consecutive infrainguinal vein bypass operations with PTFE reinforcement in 57 limbs. Indications for s…
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…
A Generalized Method for High‐Speed Fluorination of Metal Oxides by Spark Plasma Sintering Yields Ta 3 O 7 F and TaO 2 F with High Photocatalytic Act…
2021
A general method to carry out the fluorination of metal oxides with poly(tetrafluoroethylene) (PTFE, Teflon) waste by spark plasma sintering (SPS) on a minute scale with Teflon is reported. The potential of this new approach is highlighted by the following results. i) The tantalum oxyfluorides Ta3 O7 F and TaO2 F are obtained from plastic scrap without using toxic or caustic chemicals for fluorination. ii) Short reaction times (minutes rather than days) reduce the process time the energy costs by almost three orders of magnitude. iii) The oxyfluorides Ta3 O7 F and TaO2 F are produced in gram amounts of nanoparticles. Their synthesis can be upscaled to the kg range with industrial sintering …
ePTFE functionalization for medical applications
2021
Abstract Polytetrafluoroethylene (PTFE) is a ubiquitous material used in implants and medical devices in general due to its high biocompatibility and inertness; blood vessels, heart, jawbone, nose, eyes, or abdominal wall can benefit from its properties in the case of disease or injury. Its expanded version, ePTFE, is an improved version of PTFE with better mechanical properties, which extend its medical applications. However, ePTFE implants often lack improvement in properties such as antibacterial, antistenosis, or tissue integration properties. Improvements in these properties by several strategies of functionalization for medical purposes are discussed in this review. Covalent and non-c…
Hemostatic agents in endodontic surgery of maxillary molars : a randomized controlled pilot study of polytetrafluoroethylene (PTFE) strips as an adju…
2019
Background Hemostasis is of critical importance in endodontic surgery. Studies on bleeding control in maxillary molars are scarce. The present study compares the efficacy of two hemostatic techniques in controlling bleeding in endodontic surgery. Material and Methods A randomized two-arm pilot study involving 30 patients with peri-radicular lesions in maxillary molars (first and second molars) was carried out including the following hemostatic agents: polytetrafluoroethylene (PTFE) strips as an adjunct to epinephrine impregnated gauze (test group; n = 15) and aluminum chloride (Expasyl™) (control; n = 15). Bleeding control was independently assessed by the surgeon and by two blinded observe…