Search results for " resin"
showing 10 items of 268 documents
Hyaluronic acid and its derivatives in drug delivery and imaging: Recent advances and challenges.
2015
Hyaluronic acid (HA) is a biodegradable, biocompatible, nontoxic, and non-immunogenic glycosaminoglycan used for various biomedical applications. The interaction of HA with the CD44 receptor, whose expression is elevated on the surface of many types of tumor cells, makes this polymer a promising candidate for intracellular delivery of imaging and anticancer agents exploiting a receptor-mediated active targeting strategy. Therefore, HA and its derivatives have been most investigated for the development of several carrier systems intended for cancer diagnosis and therapy. Nonetheless, different and important delivery applications of the polysaccharide have also been described, including gene …
Aloin delivery on buccal mucosa: ex vivo studies and design of a new locoregional dosing system
2014
Context: Chemoprevention of potential malignant disorders or cancerous lesions that affect oral mucosae requires extended duration of treatment. Locoregional delivery of natural products could represent a promising strategy for this purpose. Objective: To investigate the aptitude of aloin to permeate through, or accumulate in, the buccal mucosa and to develop a new prolonged oro-mucosal drug delivery system. Materials and Methods: Permeation/accumulation of aloin from Curacao Aloe (containing 50% barbaloin) was evaluated ex vivo, using porcine buccal mucosa as the most useful model to simulate human epithelium. Oro-mucosal matrix tablets were prepared by dispersing aloin (10% w/w) in Eudrag…
Adsorption of Db and its homologues Nb and Ta, and the pseudo-homologue Pa on anion-exchange resin in HF solution
2009
Anion-exchange chromatography of element 105, dubnim (Db), produced in the 206 Cm( 19 F, 5n) 262 Db reaction is investigated together with the homologues Nb and Ta, and the pseudo-homologue Pa in 13.9 M hydrofluoric acid (HF) solution. The distribution coefficient (K d ) of Db on an anion-exchange resin is successfully determined by running cycles of 1702 chromatographic column separations. The result clearly indicates that the adsorption of Db on the resin is significantly different from that of the homologues and that the adsorption of anionic fluoro complexes of these elements decreases in the sequence of Ta ≈ Nb > Db > Pa.
Sealing capacity of a photochromatic flowable composite as protective base in nonvital dental bleaching.
2006
Aim To evaluate microleakage of a flowable composite used as a protective isolating base, applied with different adhesive systems. Methodology Seventy root-filled teeth were divided into seven groups. A flowable composite base (Tetric Flow Chroma) was used with three adhesive techniques (Syntac, Excite, Excite DCS; in the three cases with and without acid etching) and in a control group without dentine conditioning or adhesive placement. A 30% hydrogen peroxide solution was applied for 24 h in the pulp chambers, followed by the placement of a dye (silver nitrate) for 4 h. Each tooth was sectioned longitudinally, and examined under 4× magnification to assess the tooth/restoration dye leaka…
Microleakage in Class II composite restorations with margins below the CEJ: in vitro evaluation of different restorative techniques.
2012
Objectives: The purpose of this in vitro study was to evaluate the microleakage in "deep" Class II composite restorations with gingival cavosurface margin below the CEJ (cemento-enamel junction) and restored with different techniques. Study Design: Fifty human teeth were used. In each tooth two standardized Class II slot cavities (on mesial and on distal surfaces) were prepared: the buccolingual extension of the cavities was 4 mm; the gingival wall was located in dentin/cementum (2 mm beyond the CEJ). The prepared teeth were randomly assigned to 5 experimental groups (of 10 specimens and 20 cavities each) and restored. Group 1: Filtek TM Supreme XTE Flowable (3MESPE) + Universal Filtek Supr…
Marginal integrity of different resin-based composites for posterior teeth: an in vitro dye-penetration study on eight resin-composite and compomer-/…
2002
Abstract Objective: To determine improvements in marginal adaptation of resin-based composite restorative systems by means of flow-composites (Solitaire 2/Gluma Solid Bond, Solitaire 2/Flow Line/Gluma Solid Bond, Point 4/Optibond Solo Plus, Point 4/Revolution/Optibond Solo Plus) and to determine the equality of simplified bonding systems (Solitaire 2/Gluma Comfort Bond, Tetric Ceram/Tetric Flow/Excite, Dyract AP/Prime & Bond NT/NRC, Pertac II/Prompt-L-Pop) in marginal gap formation. Methods: The marginal dye penetration (2% methylene-blue) was investigated separately for the approximal boxes of Class II mod-cavities with one cervical margin of the approximal box within enamel, the other wit…
Highly selective generation of vanillin by anodic degradation of lignin: a combined approach of electrochemistry and product isolation by adsorption
2015
The oxidative degradation of lignin into a variety of valuable products has been under investigation since the first half of the last century. Especially, the chance to claim this cheap, abundant and renewable source for the production of the important aroma chemical vanillin (1) was one of the major driving forces of lignin research. So far most of the developed methods fail in technical application since no viable concept for work-up is included. This work represents a combined approach of electrochemical conversion of Kraft lignin and product recovery by adsorption on a strongly basic anion exchange resin. Electrolysis conditions are optimized regarding reaction temperatures below 100 °C…
POLYMER ELECTROSPUN NANOFIBERS AS INTERLEAVES FOR ENANCHEMENT OF CFRP LAMINATES DELAMINATION RESISTANCE
2019
Electrospinning process is a technique to produce nanoscale fibers that has evinced more interest in recent years due to its versatility and potential for applications in several applications. The mall size and the concomitant ultra-high specific surface area of electrospun nanofibers make them suitable for several applications, such as tissue engineering, biosensors, filtration and advanced polymer composites (1). In particular for carbon fiber reinforced polymers (CFRPs) the huge specific surface area of electrospun nanofibers results in very large interfacial area between nanofibers and polymer matrix and therefore leads to substantial improvement of fiber-matrix interfacial interactions…
Combined effects of electric toothbrushing and dentifrice on artificial stain removal : an in vitro study
2018
This in vitro study aimed to clarify the combined effect of electric toothbrushing and dentifrice on the removal of artificial stain. Twenty-five bovine incisors were cut at the cervix and the crown was embedded in auto-cured acrylic resin. Specimens were abraded using #240 SiC paper to obtain a flat enamel surface, and 20 specimens were treated with 10% citric acid / 3% ferric chloride solution followed by 1% tannic acid solution to produce surface staining. They were divided into four groups: 1) brushing with an electric toothbrush and whitening dentifrice (group S+B); 2) brushing with an electric toothbrush and fluoride dentifrice (group S+C); 3) brushing with an electric toothbrush and …
Application of Gas Chromatography coupled with Mass Spectroscopy (GC/MS) to the analysis of archaeological ceramic amphorae belonging to the Carthagi…
2017
<p class="Abstract"><span lang="EN-US">The aim of this preliminary work was to identify characteristic compounds in 7 underwater marine ceramic amphorae sherds dating from the period of the battle of the Egadi Islands that decided the end of the First Punic War (241 B.C.) by Gas Chromatography coupled with Mass Spectroscopy (GC/MS).</span></p>