ABSTRACT
In this work, usage of a hybrid polymeric ion exchange resin and a polymeric ion exchange membrane in the same unit to remove Li+ from aqueous solutions was reported. The effects of the applied potential difference to the electrodes, the flow rate of the Li-containing solution, the presence of coexisting ions (Na+, K+, Ca2+, Ba2+, and Mg2+), and the influence of the electrolyte concentration in the anode and cathode chambers on Li+ removal were investigated. At 20 V, 99% of Li+ was removed from the Li-containing solution. In addition, a decrease in the flow rate of the Li-containing solution from 2 to 1 L/h resulted in a decrease in the removal rate from 99 to 94%. Similar results were obtained when the concentration of Na2SO4 was decreased from 0.01 to 0.005 M. The selectivity test showed that the simultaneous presence of monovalent ions such as Na+ and K+ did not change the removal rate of Li+. However, the presence of divalent ions, Ca2+, Mg2+, and Ba2+, reduced the removal rate of Li+. Under optimal conditions, the mass transport coefficient of Li+ was found as 5.39 × 10-4 m/s, and the specific energy consumption was found as 106.2 W h/g LiCl. Electrodeionization provided stable performance in terms of the removal rate and transport of Li+ from the central compartment to the cathode compartment.
ABSTRACT
Serum adenosine deaminase (ADA) has been previously proposed to predict disease activity in patients with rheumatoid arthritis (RA). The aim of this study was to investigate the level of serum ADA, and the relationship between ADA and disease activity markers, in a group of patients with RA. A hundred and 10 patients with a diagnosis of RA were recruited from outpatient clinic of Rheumatology Unit. Demographic properties comprising age, gender, disease duration and drugs were recorded. Disease activity based on disease activity score (DAS)28-erythrocyte sedimentation rate (ESR) and DAS28- C reactive protein (CRP,) ESR, CRP levels, as well as pain by visual analog scale and rheumatoid factor (RF) were recorded. Serum ADA levels (IU/L) were determined in all RA patients and in 55 age and sex similar healthy control subjects. Ninety-six female and 14 male RA patients with a mean age of 54.32±11.51, and with a mean disease duration of 11.5±9.13 years were included to the study. The control group comprised of 48 female and 7 male healthy subjects. 35.5% of the patients were on methotrexate (MTX) and 64.5% of patients were on combined DMARDs or combined MTX and anti-TNF therapies. The mean serum ADA level was statistically higher in RA patients than in control subjects (27.01±10.6 IU/L vs 21.8 ±9.9 IU/L). The mean values of ESR (23.2±14.8 mm/h), CRP (1.71±1.11mg/dL), pain by VAS (37.2±27.1), DAS28-ESR (2.72±0.77), DAS28 CRP (1.37±0.5) were not correlated with ADA levels (p>0.05). Our results have shown that serum ADA levels are higher in RA patients than in controls but were not related with any of the disease activity markers. We conclude that ADA in the serum may not be a reliable biochemical marker to predict disease activity in patients with RA.
