SEARCH · Search PubMed
Results for “ION EXCHANGE”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
[Synthetic ion exchange resins].
Explore the source record for details and available documents.
Ion-exchange chromatography method for the purification of genomic DNA fraction from Mycobacterium bovis Bacillus Calmette-Guérin.
The goal of this study was to provide practical strategies for purifying genomic DNA fraction from Mycobacterium bovis Bacillus Calmette-Guérin (BCG-DNA) by ion-exchange chromatography. A multistep process was developed to purify BCG-DNA. The process consisted of sonication, heating, trypsin digestion, ion-exchange chromatography, gel-filter chromatography, and lyophilization. After ion-exchange chromatography, BCG-DNA was highly purified and possessed potent biological effects. The methods described were efficient and had good reproducibility. Further, this was the first reported chromatography method to purify BCG-DNA.
Effect of ion-exchange site and eluent modifiers on the anion-exchange of carboxylic acids.
The chromatographic behavior of carboxylic acids has been investigated, on three different latex-based anion-exchange columns, in order to define the effect of the ion-exchange site structure on selectivity. The analytical columns produced are characterized by alkyl amines containing zero, one or two hydroxyl groups on the anion-exchange functional site. Divalent carboxylic acids, namely fumaric, maleic, trans-beta-hydromuconic, trans,trans-muconic, oxalic, malonic, succinic, glutaric, adipic, malic, tartaric and mucic acids, have been chosen as test solutes. The performance of the three stationary phases has been studied employing NaOH eluents and has been discussed with respect to the different hydrophilicity of the ion-exchange sites and analytes. Considering on previous results obtained using organic solvents (methanol and acetonitrile) with carbonate eluents on a highly hydrophilic column, the performance of the three exchangers has also been studied using acetonitrile, methanol and n-propanol. The chromatographic behavior was similar for the three columns studied, but the different organic solvents gave variations in selectivity. In order to characterize these differences, particle size measurements of the latices were performed both in pure water and in the presence of each organic solvent studied.
Separation of nucleic acids by high-performance ion-exchange chromatography.
Separation of various nucleic acids was evaluated by high-performance ion-exchange chromatography on non-porous resin, TSKgel DNA-NPR. A 1 kb ladder DNA was studied as a model DNA on operational variables like flow rate, gradient time, temperature, sample load, etc.. As results, various DNA fragments were well separated within 15 min by 20 min linear gradient at a flow rate between 0.5 and 0.75 ml/min at room temperature while the resolutin was dependent on molecular weight of the sample. The relationship between sample load and its peak area was examined on polymerase chain reaction (PCR) product. The product was found to be quantitatively recovered even with nanogram loads. The detection limit was 3.8 ng at signal to noise level (S/N) of 3. This non-porous ion-exchanger also showed high resolution on separation of ther nucleic acids like transfer RNA, oligonucleotides (single-stranded) DNA.
Calcium exchange diffusion in a porous phospholipid ion-exchange membrane.
Explore the source record for details and available documents.
Connective tissue responses to some heavy metals. I. Sodium loaded ion exchange beads as a control: histology and ultrastructure.
Ion exchange resin beads (Amberlite IR-120) were implanted into loose connective tissue as the vehicle for cations in both control and experimental studies. Beads were loaded with sodium for control purposes or with the metal of interest for subsequent experimental studies. When single control beads were implanted in the loose connective tissue of the rat pinna, they were well accepted by tissue and permitted rapid healing. The bead implantation initially produced minimal inflammatory disruption and subsequent repair at the bead-tissue interface which rapidly matured leaving no fibro-collagenous capsule. Some minor geometric rearrangement occurred in the alignment of the connective tissue to compensate for the physical presence of the bead. This system provides a valid control for studies of the effects of metal cations on tissue inflammation and repair--free from anionic complications, surface phenomena or systemic interference.
Synthesis of CdSnO(3).3H(2)O nanocubes via ion exchange and their thermal decompositions to cadmium stannate.
Uniform crystalline CdSnO3.3H2O nanocubes with a 28-35 nm edge length have been obtained via the ion-exchange reaction of Na2Sn(OH)6 in a CdSO4 aqueous solution, assisted by ultrasonic treatment. Precursor Na2Sn(OH)6 crystals were prepared via hydrothermal treatment in an ethanol/water solution. The formation of CdSnO3.3H2O nanocubes resulted from the strain during the ion-exchange process. The influences of reaction conditions, such as ion-exchange (ultrasonic treatment) duration, solvent constitutes, surfactant, and pH on the formation of CdSnO3.3H2O crystals were described. Crystalline CdSnO3 and Cd2SnO4 have been obtained by thermal treatment at 300 and 500 degrees C, respectively, for 5 h under an inert-gas protecting condition using CdSnO3.3H2O nanocubes as the precursor. The cube shape of CdSnO3.3H2O was sustained after thermal decomposition to CdSnO3.
The K+ liquid ion exchange electrode system: responses to drugs and neurotransmitters.
K+-sensitive liquid ion exchange electrode systems respond with a slow potential change to acetylcholine, choline, anticholinergic drugs, biogenic amines, and glutamic acid. The response threshold has been defined, and in most cases it is at extremely low concentrations (10(-7)-10(-5)M). The direction of the potential change varies, but in most instances it is additive to that produced by external K+. The K+ electrode system is further sensitive to decreasing pH, within a narrow and possibly physiological range of pH. These findings suggest that small measured changes in extracellular K+ are biased by the chemosensitivity of the liquid ion exchange electrode system to some compounds of physiological importance.
Identification of membrane transport processes in renal cells, by means of liquid ion exchanger microelectrodes.
The development of liquid-ion-exchanger microelectrodes displaying tip diameters less than or equal to 1 micron has permitted direct measurement of the transmembrane chemical and electrochemical gradients of several permeant ion species in cells of small size. We have used Cl- and H+ resins to study the intracellular Cl- activity (alpha iCl) and cell pH (pHi) in the proximal tubule of Necturus kidney. These determinations were performed in association with perfusion of peritubular capillaries by several artificial solutions, in order to assess the dependence of alpha iCl and pHi on the composition of physiologic plasma constituents and selected inhibitors. The main findings are: Intracellular chloride activity, alpha iCl, is higher than the theoretical value predicted from electrochemical equilibrium. Peritubular application of SITS resulted in a decrease of alpha iCl and increase of pHi; these observations are taken to indicate that Cl- uptake is achieved across the basolateral membrane in exchange for HCO-3 by a mechanism sensitive to SITS. Na+ removal from peritubular fluid elicited a small reduction of alpha iCl, suggesting the presence of carrier-mediated Cl--Na+ cotransport from interstitium to cell, contributing to the rise of alpha iCl above equilibrium. In conclusion, two carrier-mediated processes (Cl-/HCO-3 exchange and Cl--Na+ symport) located at the basolateral membrane of the proximal tubule may account for the establishment of alpha iCl values above equilibrium, at steady state. The physiologic role of these carriers is discussed in relation to proximal electrolyte absorption.
Separation of 90Y from 90Sr using zirconium vanadate as the ion exchanger.
The sorption and desorption behaviour of several radionuclides, including 241Am, 152,154Eu, 233U, 137Cs, 90Sr and 90Y was studied under varying acidities using zirconium vanadate as ion exchanger. The sorption follows the order: Cs > Eu > Am >Y > U, while Sr was not taken up by the ion exchanger. A radiochemical separation scheme for the 90Y daughter from its 90Sr parent using zirconium vanadate ion exchanger has been developed. The exchanger was synthesized and characterized in our laboratory.
High-performance ion-exchange chromatography with in-line complexation of bisphosphonates and their quality control in pharmaceutical preparations.
An ion-exchange chromatographic method using an anion-exchange column was developed for the analysis of a number of bisphosphonates. The bisphosphonates were in-line complexed by copper(II) ions and added to the acidic eluent, to yield an UV-absorbing complex. Chromatographic parameters were studied for eight different bisphosphonates, particularly amino-1-hydroxyalkyl-1,1-bisphosphonates; special attention was paid to the relationship between retention and complex formation. The method was applied to the quality control of pamidronate injection concentrate and olpadronate tablets. The lower detection limit was 8 ng of disodium pamidronate, and the inter-assay precision was 1.0% for both pamidronate and olpadronate standard solutions and 1.8% for a 3 mg ml-1 disodium pamidronate injection concentrate. The method was compared with a previously described ion-exchange chromatographic method with conductivity detection, without copper(II) ions in the eluent.
Adsorption of inulinases in ion-exchange columns.
The use of adsorption columns packed with ion-exchange resins for recovering, concentrating and purifying proteins is now widespread. The present work consists of a study on the dynamic behavior of adsorption columns that uses two kinds of adsorbents: a cationic and an anionic resin. A frontal analysis of the columns was performed with experimental data obtained from Fructozyme, a mixture of inulinase enzymes. The parameters of a Langmuir type of isotherm and adsorption kinetics were obtained from experimental tests in a batch system. A numerical technique based on orthogonal collocation and a fourth-order Runge-Kutta method was coupled with a nonlinear optimization method to predict the coefficients of the rate equations, which are fundamental for scale-up purposes.
Synthesis, characterization, and ion exchange behavior of antimony(V) phosphate: selective adsorption of cadmium and mercury on its column.
Antimony(V) phosphate has been prepared as a new inorganic ion exchanger suitable for the selective adsorption of cadmium and mercury, the two chief polluting metals. The materials possesses good ion exchange capacity and stability, both thermal and chemical. It has also been characterized and an empirical formula has been proposed on the basis of its chemical analysis and certain instrumental studies like infrared spectroscopy, X-rays, thermogravimetry, derivative thermogravimetry, differential thermal analysis, and pH titrations.
Isolation of oestriol-16 (17?)-glucosiduronate by means of an ion exchange resin.
Explore the source record for details and available documents.
[Demineralization of the water by ion exchange. 2].
Explore the source record for details and available documents.