Dialysis system

Sodium hydrogen zirconium phosphate [34370-53-17 is an ion-exchange material used in portable kidney dialysis systems which regenerate and reckculate the dialysate solution. The solution picks up urea during the dialysis. The urea reacts with urease to form ammonia, which is absorbed by the sodium hydrogen zirconium phosphate. 

Reverse Osmosis Membrane Cleaning. Citric acid solutions are used to remove iron, calcium, and other cations that foul ceUulose acetate and other membranes in reverse osmosis and electro dialysis systems. Citric acid solutions can solubilize and remove these cations without damaging the membranes (94—96). 

Artificial heart Kidney-dialysis system Artificial blood (synthetic oxygen carriers)... 

Distribution of241 Am in a dialysis system containing sediment, phytoplankton, and detrital matter established that a substantial amount of americium accumulated in all three phases both in fresh and marine waters (NRC 1981). The adsorption process was not reversible and the longer the americium was adsorbed, the more difficult the chemical was to desorb. Appreciable amounts of americium have been shown to adsorb to bacterial cells such as those found in the Waste Isolation Pilot Plant in New Mexico (Francis et al. 1998). There is a potential that americium attached to biocolloids may facilitate its transport from the waste site. 

Ottiger, C. Wunderli-Allenspach, H., Partition behavior of acids and bases in a phosphatidylcholine liposome-buffer equilibrium dialysis system, Eur. J. Pharm. Sci. 5, 223-231 (1997). 

Brain tissue Homogenization in coid 0.01 M NaOH. Centrifuge and resuspend pellet add zinc acetate and ascorbic acid readjust pH use continuous flow gas dialysis system to separate sulfide. Gas dialysis/ion chromatography with ECD 0.02 pg/g 95-100% Goodwin et al. 1989... 

In this method the sample is acidified and the inorganic carbon is removed with nitrogen. An aliquot is resampled for analyses. Buffered persulfate is added and the sample is irradiated in the ultraviolet destructor for about 9 min. The hydroxylamine is added and the sample stream passes into the dialysis system. The carbon dioxide generated diffuses through the gas-permeable silicon membrane. A weakly buffered phenolphthalein indicator solution is used as the recipent stream, and the colour intensity of this solution decreases proportionately to the change in pH caused by the absorbed carbon dioxide... 

We have recently turned our attention to cellulose-heparin, blood-compatible, nanoporous composite membranes for use in kidney dialysis (Murugesan et al., 2006a, b). Advanced kidney dialysis system contains heparin covalently bound to the surface of biomaterials to reduce clotting effects. Our new approach relies instead on composite materials. Unfortunately, no technology has been available to... 

Hemodialysis Topiramate is cleared by hemodialysis 4 to 6 times greater than in a healthy individual a prolonged period of dialysis may cause topiramate levels to fall below that required to maintain an antiseizure effect. To avoid rapid drops in topiramate plasma concentration during hemodialysis, a supplemental dose of topiramate may be required. The actual adjustment should take into account 1) the duration of the dialysis period, 2) the clearance rate of the dialysis system being used, and 3) the effective renal clearance of topiramate in the patient being dialyzed. 

A process similar to osmosis is dialysis. In dialysis, a dialyzing membrane allows both solvent and minute solute particles of a certain size to pass. The passage of these particles, like osmosis, is from a region of high concentration to a region of low concentration. Our kidneys are a dialysis system responsible for the removal of toxic wastes from the blood. In artificial dialysis, blood is circulated through dialysis tubes made of membranes, which are immersed in a clean solution that lacks the wastes in the blood. The impurities are filtered out of the blood as they move across the walls of the dialyzing tubes. 

Dialysis procedures are relatively slow when mass transfer is based only on diffusion. These procedures do not offer particular selectivity when they are concurrently used for extraction and cleanup purposes, because many low-molecular-weight sample components along with the analyte can pass through the membrane. Dialysis systems must be renewed frequently, automation is difficult except for the continous-flow systems, and there is a significant temperature dependence. 

Concentration Method. The concentration procedure that was developed and evaluated was a RO-Donnan dialysis system (4). The initial objective during method development was to conduct membranescreening tests to evaluate the suitability of various RO and ion-exchange membranes. The four membranes considered for final evaluation on the basis of solute rejection, chlorine stability, and artifact production were the cellulose acetate and FT-30 (Film Tec) RO membranes, the Nafion cation-exchange membrane, and the ION AC MA 3475 anion-exchange membrane. 

The dialysis system is low cost and includes valves, pumps, capillary dialysis cartridges, and reservoirs. The number and the types of the dialysis cartridges can be varied, for example, two or more cartridges can be connected in a consecutive mode. Several types of disposable cartridges a available that differ in the total surface area available, void volume, and ultraLltration rate. 

All potentials vs. screen-printed pseudo Ag/AgCl reference, except values marked with double-dagger (J), which are vs. screen-printed Ag/Pd, and 02 those marked with asterisk ( ), which are vs. Ag/3M AgCl double-junction reference electrode. Abbreviations LDH lactate dehydrogenase, LOD lactate oxidase, PVA-SbQ styrlpyridinium-modified poly(vinyl alcohol), FIA flow injection analysis. aLinear ranges using a dialysis system. 

Ultrasonic vibration (49 kHz) of a PZT disk adhered to a Si chip through a thin Si diaphragm was used for degassing in a portable dialysis system. When the dissolved 02 in the dialysate is reduced to 6 ppm (from 8 ppm), no 02 gas bubbles will be generated inside the dialyzer during normal operation [404]. 

Yang, Z., Matsumoto, S., Maeda, R., A prototype of ultrasonic micro-degassing device for portable dialysis system, Sensors Actuators A 2002, 95, 274-280. 

In hemodialysis, blood from the patient flows on one side of a membrane and a specially prepared dialysis solution is fed to the other side. Waste material in the blood such as urea, excess acids, and electrolytes diffuse into the dialysate the blood is then returned to the patient, as shown in Fig. 48. A patient typically undergoes dialysis three times per week in sessions lasting several hours each. Modern dialysis systems combine sophisticated monitoring and control functions to ensure safe operation. Regenerated cellulose was the first material used in hemodialysis membranes because of its biocompatibility and low cost it remains the most popular choice. Subsequently, high-permeability dialysis membranes derived from cellulose esters, modified polysulfone, or polyacrylonitrile copolymers have also gained wide acceptance because of the shorter sessions they make possible. 

Scale-up of cell cultures makes use of suspension cultures (erythropoietic cells or microcarriers) or, less often use of capillary beds (hollow fibre systems or glass bead columns), but these suffer from the same disadvantages seen with smaller scale cultures ( 3.4.4). In particular, nutrients are depleted as the medium flows through long columns or beds and high rates of flow coupled with recirculation are often employed. Nevertheless, Organon have used a hollow fibre dialysis system for production of monoclonal antibodies (Schonherr et al., 1985). Invitron s hollow fibre system has been used to produce cell conditioned media and the Cell-Pharm System (Jencons Ltd. Appendix 3) will produce up to 20 g cell secreted product per month. 

One salient example of the need for degassing in the clinical field and of the effectiveness of ultrasound for this purpose is a prototype of ultrasonic micro-degassing device for portable dialysis systems. The bubbles inside these systems reduce the effective exchange surface area, which is extremely important here [104]. 

L. Clinical effects of a sorbent suspension dialysis system in treatment of hepatic coma (the Biologic-DT). Intern. J. Artif. Org. 1992 15 151-161... 

Several isotopic methods have been used to accurately estimate the free hormone fraction, including equilibrium tracer dialysis, ultrafiltration, Sephadex chromatography, and polyacrylamide gel filtration. However, these techniques are very cumbersome and time consuming for routine clinical use and, with the exception of equilibrium tracer dialysis, have found little practical application. Unfortunately the free hormone fraction as estimated in normal sera by equilibrium tracer dialysis varies substantially among laboratories. Methodological difficulties include the presence of residual impurities in the tracer, the temperature and duration of dialysis, tlie adsorption of tracer by components of the dialysis system, and the in vitro generation of free fatty acids. ... 

Based on Donnan s [18, 19] and Onsager s [41, 42] fundamental works, the theories for Donnan dialysis systems were developed [20-26, 32-36]. The BAHLM system could be considered as two DD systems, operating in consecutive order, continuously in one module (see Fig. 6.2) the first is composed of feed/LM and the second is composed of LM/strip compartments, separated by ion-exchange membranes. Therefore, the Kedem-Katchalsky equations [43, 44] can be applied to our case ... 

As was shown in the BAHLM model for transport kinetics, the values of the overaU mass-transfer coefficients govern the location (i ax) and the maximum quantity (Ofemax) of the metal species in the LM phase (see Eqs (27) and (28)). At Ormax Qf, the BAHLM is working mainly as a Donnan dialysis system, in which the loaded carrier solution is a treated feed. In this... 

Copper used in the wiring of dialysis systems may be leached in an acidic medium. It then diffuses into the blood, causing hemolysis. Symptoms consist of flushing, chills, nausea, vomiting, abdominal cramps, and diarrhea. This problem can be avoided by deionization of the dialysis water. The deionizer should be checked periodically to assure it is not being exhausted (M23). 

The use of tubular Donnan dialysis systems has stimulated attempts to provide predictive models, principally for industrially oriented applications. Ng and Snyder (39) have recently published one such attempt applied to dialysis of nickel(II) into a sulfuric acid receiver solution. Correlations between mass transport coefficient and Reynolds number are reported, and the factors controlling transport over a range of nickel concentrations are discussed. 

A significant leap forward was made in 1988 by Spirin et al. [4], who developed a continuous-flow apparatus for the continuous supplementation of reaction mixtures with substrates required for protein synthesis and continuous removal of reaction by-products. In this way, it was shown that the activity of a cell-free system could be sustained for many hours, compared with batch-mode reactions which became inactive after approximately 45 minutes. Since then, many reports have been made describing the use of simple dialysis systems [3, 5] that can maintain the high productivity of a reaction over many hours, without the use of a cumbersome apparatus. 

What is an advantage of a hollow-fiber dialysis system ... 

XiE RY and Christian GD (1986) Serum lithium analysis by coated wire lithium ion selective electrodes in a flow injection analysis dialysis system. Anal Chem 58 1806-1810. 

Figure 4.37. Schematic diagram of a flow-injection serial dynamic dialysis system in which the acceptor part of a dialysis unit constitutes the sample loop of a rotary injection valve (RV). RP, reagent pump SP, sample pump RCl and RC2, reaction coils and W, waste. (From Ref. 1268 by permission of Elsevier Scientific Publishing Co.)...

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