Search results for "icone"
showing 10 items of 95 documents
Designing Medical Devices Based on Silicon Polymeric Material with Controlled Release of Local Anesthetics
2012
The drug delivery systems that are the object of this article take the form of a polymer matrix made of silicone containing a drug. These devices can be used as patches for local dermal applications releasing the drug in a controlled manner. The model active agent, lidocaine hydrochloride was chosen from the range of local anesthetics. When the drug is restricted to the surface, it is released more rapidly than when it is allowed to spread evenly throughout the silicon structure. When hydrophilic polymers such as PVA and HEC are mixed in with the lidocaine hydrochloride and deposited on the surface of the polymer matrix, we observed that the burst effect was eliminated without modifying the…
Study by FT-IR spectroscopy of ageing of adhesives used in restoration of archaeological glass objects
1999
Abstract A study by FT-IR spectroscopy which aims to compare the stability of five polymers, Araldit XW396/XW 397, Vitralit 7256, Loctite 350, Desmodur N 75/Viacryl SM 564/65 and Krafft silicone commonly used in the restoration of archaeological glass objects when subjected to thermal ageing, UV light ageing and cyclic ageing in SO 2 pollutant chamber has been carried out. Two series of test specimens were prepared in order to reproduce the two methods of application of polymers commonly used in restoration treatments as adhesive and consolidant or coating of glass fragments. Modifications in the chain or side chain structure of polymers, alterations of carbonyl groups in Araldit and isocya…
Preparation of actuating fibres of oriented main-chain liquid crystalline elastomers by a wetspinning process
2011
We present a versatile method to prepare oriented fibres with a defined thickness from main-chain liquid crystalline elastomers. A microfluidic setup is utilized to inject a solution of a photocrosslinkable smectic A main-chain polymer into a co-flowing stream of silicone oil. Diffusion of the solvent into the oil yields solid polymer filaments that are crosslinked in a continuous way by UV-irradiation. The obtained fibres are highly oriented and show a reversible and significant contraction during the liquid crystal's phase transition.
Aligned microcontact printing of biomolecules on microelectronic device surfaces
2001
Microcontact printing (/spl mu/CP) of extracellular matrix proteins is a fascinating approach to control cell positioning and outgrowth, which is essential in the development of applications ranging from cellular biosensors to tissue engineering. Microelectronic devices can be used to detect the activity from a large number of recording sites over the long term. However, signals from cells can only be recorded at small sensitive spots. Here, the authors present an innovative setup to perform aligned /spl mu/CP of extracellular matrix proteins on microelectronic devices in order to guide the growth of electrogenic cells specifically to these sensitive spots. The authors' system is based on t…
Physicochemical Surface Properties of Various Intraocular Lenses
2001
<i>Purpose:</i> It is of major interest to understand how intraocular lens (IOL) surfaces interact with aqueous humor or tissues after implantation. Important parameters to describe the physicochemical surface properties are the contact angle and critical surface tension. Therefore, we performed measurements of the contact angle and critical surface tension of several commercially available IOLs. <i>Setting:</i> Department of Ophthalmology, Johannes Gutenberg University, Mainz, University Eye Hospital, Tübingen, and Max Planck Institute for Polymer Research, Mainz, Germany. <i>Methods:</i> A total of 17 commercially available standard quality IOL types (6…
Tear Film Surface Quality in Modern Daily Disposable Contact Lens Wear
2021
Objectives As reported previously, tear film surface quality (TFSQ) should be considered in contact lens (CL) fitting. This study followed noninvasive keratograph tear film break-up time (NIKBUT) in CL wearers for 12 months to validate its clinical utility in predicting CL performance. Methods Fifty-five subjects (M/F=17/38) aged 26±4 years were prescribed silicone hydrogel or hydrogel CLs. The study included baseline measurements without CLs; 2 visits for CL fitting and control; follow-up after 3, 6, and 12 months of CL wear; and postwear visit without CLs. Ocular Surface Disease Index (OSDI), 8-Item Contact Lens Dry Eye Questionnaire (CLDEQ-8), first and mean NIKBUT (F/M-NIKBUT), fluoresc…
Effectiveness of semi-permeable dressings to treat radiation-induced skin reactions. A systematic review
2017
The aim of this systematic review is to assess the available evidence concerning the effectiveness of semi-permeable dressings, on the full range of skin reactions, related to radiation therapy in cancer patients, from local erythema to moist desquamation, including subjective symptoms such as pain, discomfort, itchiness, burning and the effect on daily life activities. The bibliographic search was carried out looking for Randomised Clinical Trials (RCTs) indexed in PubMed, Cinhal, Cochrane plus and Biblioteca Nacional de Salud, published in the English and Spanish language, between 2010 and 2015. Data extraction and evaluation of study quality was undertaken by peer reviewers using the Cri…
Dynamic in vitro dehydration patterns of unworn and worn silicone hydrogel contact lenses.
2008
Purpose: To evaluate the effect of wear on dynamic in vitro dehydration of silicone hydrogel (Si-Hi) contact lens (CL) using a previously described gravimetric procedure. Methods: Five different silicone hydrogel (Si-Hi) contact lenses (CL) were evaluated after being worn by patients under daily wear conditions for 15 days to 1 month. Lenses were conditioned and disinfected with a multipurpose solution after each day of wear. Lenses were left to dehydrate in an analytical balance under controlled conditions of temperature and relative humidity and the results compared with data from new lens samples of the same power and material. Several quantitative parameters were obtained and compared b…
Gastric Banding for Treatment of Morbid Obesity: Preliminary Results.
1995
Background: gastric banding (GB) has been used for treatment of morbid obesity. Methods: a banding device, introduced by Broadbent and consisting of a self-blocking nylon strip covered with a silicone tube, was used in 13 patients who have completed 1-year follow-up. This device was used for its mechanical properties, biocompatibility, ease of insertion and low cost. Results: at 1 year, mean excess weight loss was 51.6%, with all but one patient losing more than 25% of excess weight. Associated illnesses resolved. There were two complications (15%): one patient required band removal for self-induced vomiting and one patient required repair of an incisional hernia. Conclusions: GB has had go…
A diagnostic trap for the dermatopathologist: granulomatous reactions from cutaneous microimplants for cosmetic purposes.
2007
We present a case of late granulomatous reactions from silicone that first appeared in a site different from that of the injection causing an incorrect diagnosis of liposarcoma in the beginning. The histological picture was a cystic-macrophagic granuloma in both the injection site (upper lip) and the migrating site (paranasal regions). We think that the foreign body has undergone an antigravity migration from the upper lip to the right paranasal region. To our knowledge, such a phenomenon has not been yet reported in literature.