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Rheumatoid arthritis (RA) is a chronic autoimmune disease caused by established chronic inflammation. Neopterin levels have extensively been considered as a marker of immune activation during inflammation. In this study, we performed a systematic evaluation and meta-analysis to elucidate the overall relationship between neopterin concentration and RA disease activity. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, a systematic review was conducted using PubMed, Google Scholar, Web of Science, and Scopus from 2000 to August 2020. The Newcastle-Ottawa scale was used to assess the quality of eligible studies. The effect size (ES) and corresponding 95% confidence intervals (CIs) were calculated to evaluate this association. A total of 15 studies out of 98 met our inclusion criteria. The pooled analysis found that patients with RA had high level of neopterin; however, no statistically significant association was found between neopterin levels with high, intermediate, and low diseases activity score (DAS)-28 (ES =11.18, 95% CI: 6.02 to 16.34, and I2 = 91.8%; and ES = 8.57, 95% CI: 6.41 to 10.37, and I2 = 99.5%; and ES =12.45, 95% CI: -1.68 to 26.58, and I2 = 99.0%, respectively). Our results indicated that the neopterin concentration does not seem to have any substantial impact on the RA disease activity.

A series of 1-(4-(2-allylphenoxy)butyl)piperidin-1-ium halides (4a-d) was synthesized and characterized via spectroscopic methods (FTIR, 1 H NMR). The corrosion inhibition of the synthesized halides on carbon steel in water-salt-hydrocarbon environment, saturated with H2 S, was investigated. For this purpose, a series of techniques such as gravimetric measurement, potentiodynamic polarisation, and scanning electron microscope (SEM) were used and some thermodynamic parameters of corrosion process (Δ Gads. , ΔH0 ads. , Δ S0 ads. ) were evaluated. The steel surface was checked by SEM, and the steel surface showed good surface coverage. The results showed that the synthesized compounds at the concentrations 125, 150 mg ×L-1 have corrosion inhibition activity of 78%-95% by gravimetric measurements and 81%-92% by potentiodynamic measurements at 100, 150 mg ×L-1. The biological activity was examined against sulphate-reducing bacteria (SRB). It was revealed that at the concentration of compounds 4c and 4d, 100 mg ×L-1, the antibacterial activity was 100%.

Liquid–liquid equilibria (LLE) for the aqueous polyethylene glycol 4000 (PEG4000) + di-sodium tartrate system and the vapor–liquid equilibria (VLE) of the corresponding binary aqueous systems (i.e. PEG4000 + water and di-sodium tartrate + water) have been determined experimentally at T = (298.15, 308.15 and 318.15) K. The effects of temperature on the binodals and tie-lines for the investigated aqueous two-phase system (ATPS), as well as the water activities obtained from the VLE data for the aforementioned binary aqueous systems have been studied. Furthermore, the modified local composition segment-based NRTL and Wilson models, proposed recently by Sadeghi to describe the VLE of several aqueous polymer–salt systems, have been used for the correlation of the phase behavior of the studied systems. Good agreement was obtained with the experimental VLE data with these models. For the studied ATPS, while the successful regeneration of the experimental LLE data were demonstrated with the modified NRTL and Wilson models, especially with the unrestricted parameters, no satisfactory results were obtained for the temperatures 308.15 and 318.15 K, using the modified Wilson model with restricted parameters in which the binary model parameters between water and the segments of polymer or salt obtained from the VLE data. Results are also compared with those obtained from the extended NRTL and the extended Wilson models.