Search results for " Resins"
showing 10 items of 155 documents
Liquid chromatography‐Orbitrap Tribrid high‐resolution mass spectrometry using data dependent‐tandem mass spectrometry with triple stage fragmentatio…
2021
A new, fast, and automatic approach has been applied for the tentative identification of unknown substances released by food contact epoxy resin after performing a migration test with food simulant. This approach combines intelligent data acquisition with AcquireX linked to liquid chromatography-Orbitrap Tribrid high-resolution mass spectrometry using data dependent-tandem mass spectrometry with triple stage fragmentation coupled to Compound Discoverer™ software for automated data processing and compound identification. The identification of the observed features was performed using a set of identification criteria, including exact mass, isotope pattern, tandem mass spectrometry spectra mat…
[The in vitro effect of the addition of ion exchange resins on the bioavailability of electrolytes in artificial enteral feeding formulas].
2008
Objective: To determine in vitro free ion concentration in 3 standard artificial enteral feeding formulas following the addition of ion exchange resins. Method: Three standard types of AEF were chosen: Osmolite HN®, Nutrison Standard®, and Isosource Standard®. The ion exchange resins used were: sodium polystyrene sulfonate and calcium polystyrene sulfonate. In a beaker were mixed 100 mL of AEF with 1.5 g or 3 g of ion exchange resins for 48 hours at 37oC. Subsequently, the samples were precipitated and the supernatant obtained was used for determining the concentrations of calcium, magnesium, sodium, and potassium ions. Results: The addition of sodium polystyrene sulfonate to different type…
Fibrin Sealants in Dura Sealing: A Systematic Literature Review.
2016
BACKGROUND:Fibrin sealants are widely used in neurosurgery to seal the suture line, provide watertight closure, and prevent cerebrospinal fluid leaks. The aim of this systematic review is to summarize the current efficacy and safety literature of fibrin sealants in dura sealing and the prevention/treatment of cerebrospinal fluid leaks. METHODS:A comprehensive electronic literature search was run in the following databases: Cochrane Database of Systematic Reviews, Cochrane Central Resister of Controlled Trials, clinicaltrials.gov, MEDLINE/PubMed, and EMBASE. Titles and abstracts of potential articles of interest were reviewed independently by 3 of the authors. RESULTS:A total of 1006 databas…
The effect of glass ionomer and adhesive cements on substance P expression in human dental pul
2013
Objectives: The purpose of this study was to quantify the effect of glass ionomer and adhesive cements on SP expression in healthy human dental pulp. Study Design: Forty pulp samples were obtained from healthy premolars where extraction was indicated for orthodontic reasons. In thirty of these premolars a Class V cavity preparation was performed and teeth were equally divided in three groups: Experimental Group I: Glass Ionomer cement was placed in the cavity. Experimental Group II: Adhesive Cement was placed in the cavity. Positive control group: Class V cavities only. The remaining ten healthy premolars where extracted without treatment and served as a negative control group. All pulp sam…
Differential staining of mucin granules from epoxy resin sections by a phosphotungstic acid-methyl green procedure.
1991
After treatment of epoxy resin semithin sections from glutaraldehyde fixed rat large intestine with 5% aqueous phosphotungstic acid (PTA), staining with unpurified 0.2% solutions of methyl green at 60 C for 5 min produces a color differentiation between mucin granules of goblet cells. Some mucin granules and the glycocalyx appear deep green while the remaining granules, luminal mucin and collagen fibers are pink. The known contamination of unpurified methyl green with crystal violet seems to be responsible for the pink staining reaction of the latter structures, which also present an orange-red fluorescence under green exciting light. Electron microscopic observations show selective contras…
New insights into the composition of historical remedies and pharmaceutical formulations: the identification of natural resins and balsams by gas chr…
2020
AbstractThe present paper reports one of the first studies on the identification of natural resins and balsams in modern era drug formulations. Gas chromatography coupled with mass spectrometry (GC-MS) was applied to investigate the composition of ancient remedies and pharmaceutical formulations coming from the Spezieria di Santa Maria della Scala in Rome, founded at the end of the seventeenth century by the Discalced Carmelites. The obtained results highlight the presence of complex mixtures containing resinaceous and lipidic-based compounds. Thanks to the detection of characteristic markers, it was possible to identify several natural resins, such as guaiacum resin, ladano resin and scamm…
Poly(N-isopropylacrylamide)-gated Fe3O4/SiO2 core shell nanoparticles with expanded mesoporous structures for the temperature triggered release of ly…
2015
Core-shell nanoparticles comprised of Fe3O4 cores and a mesoporous silica shell with an average expanded pore size of 6.07 nm and coated with a poly(N-isopropylacrylamide) (PNIPAM) layer (CS MSNs EP PNIPAM) were prepared and characterized. The nanoparticles was loaded with (Ru(bipy)3 2+) dye or an antibacterial enzyme, lysozyme, to obtain CS MSNs EP PNIPAM Ru(bipy)3 2+ and CS MSNs EP PNIPAM Lys, respectively. The lysozyme loading was determined to be 160 mg/g of nanoparticle. It was seen that Ru(bipy)3 2+ and lysozyme release was minimal at a room temperature of 25 ºC while at physiological temperature (37 º C), abrupt release was observed. The applicability of the CS MSNs EP PNIPAM Lys was…
Ion-exchange high-performance liquid chromatography of nucleotides and polypeptides on new types of ion-exchange sorbents, based on polystyrene-coate…
1991
A novel type of ion exchanger was prepared by multipoint covalent binding of polystyrene chains onto the surface of porous silica followed by polymer-analogous modification of the bonded layer. Both anion and cation exchangers were synthesized and examined in the separation of nucleotides and proteins. Rapid and efficient separation of basic polypeptides on strong anion exchangers and that of acidic polypeptides on strong cation exchangers could be achieved. For the separation of complete mixtures of polypeptides the application of zwitter-ionic ion exchangers can be recommended.
Ion-exchange fibers and drugs: a transient study.
2003
The objective of this study was to theoretically model and experimentally measure the kinetics and extent of drug release from different ion-exchange materials using an in-house-designed flow-cell. Ion-exchange fibers (staple fibers and fiber cloth) were compared with commercially available ion-exchange materials (resins and gels). The functional ion-exchange groups in all the materials were weak -COOH or strong -SO3H groups. The rate and extent of drug release from the fibers (staple fiber>fiber cloth) was much higher than that from the resin or the gel. An increase in the hydrophilicity of the model drugs resulted in markedly higher rates of drug release from the fibers (nadolol>metoprolo…