EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369

Adsorption of Lead from Aqueous Solution onto Untreated Orange Barks: Equilibrium, Kinetics and Thermodynamics

Adsorption can be used as a cost effective and efficient technique for the removal of toxic heavy metals from wastewater. Waste materials with no further treatment such as orange barks from commercial oranges may act as adsorbent for the removal of lead. Batch kinetic and equilibrium experiments were conducted to study the effects of contact time, adsorbent dose, initial pH, particle size, initial concentration of lead and temperature. Three adsorption isotherm models namely, Langmuir, Freundlich and Dubinin-Radushkevich were used to analyse the equilibrium data. The Langmuir isotherm which provided the best correlation for Pb2+ adsorption onto orange barks shows that the adsorption was favourable and the maximum adsorption capacity found was equal to 112.359 mg.g-1. Thermodynamic parameters were evaluated and the adsorption was exothermic. The equilibrium was achieved less than 30 min. The adsorption kinetic data was fitted with first and second order kinetic models. Finally it was concluded that the lead adsorption kinetic onto orange barks was well fitted by second order kinetic model rather than first order model. The results suggest that orange barks have high possibility to be used as effective and economical adsorbent for Pb2+ removal

Performances of metals modified activated carbons for fluoride removal from aqueous solutions

Abstract The present research work focused on the activated carbon (AC) preparation from dates waste followed by its surface modification by incipient wetness impregnation using different metals: Ca, Co, Mg and Al. The obtained results showed that the AC-Al presented the best removal efficiency of the fluoride. The prepared activated carbons (AC) and (AC-Al) were characterized by several techniques. The optimization study of the AC-Al impregnation conditions was investigated by varying the impregnation time and the Al loading. Batch experiments were carried out to investigate the effect of certain operating parameters on the removal percentage. Several isotherm models were applied

Optimal Extractive Separation of Chromium(VI) from Acidic Chloride and Nitrate Media by Commercial Amines: Equilibrium Modeling Through Linear Solvation Energy Relation

Data for the extraction of chromium, Cr(VI), from aqueous acidic chloride and nitrate solutions by Alamine 300 (tertiary amine)/xylene and di-n-octyl amine (DOA)/xylene solvent systems (298 K) have been subjected to formulation of an optimization structure for an effective Cr(VI) separation. The optimization approach uses a derivative variation method to efficiently identify the optimization range through analyzing the first-order derivatives of the optimized quantity and the nonlinear deviation profile of the derivative value. The main characteristics of it are simplicity and suitability for generalization. Optimum Cr(VI) removal efficiencies, defined both experimentally and analytically, range from about 70 to 90% for Alamine 300 and from 50 to 70% for DOA, being dependent about equally strongly on the types and concentration levels of the amine, acid, and the transferred Cr(VI) species. These dependencies are rationalized in terms of the interactions that take place in the equilibrium phases. Three independent variables, i.e. the concentrations of the amine, acid, and Cr(VI), are adequate for expressing the nonlinear dependence of the optimized extraction factor (E, Z(t)) on the properties of relevant system. Modeling efforts based on the LSER (linear solvation energy relation) principles and the mass-action law methodology have shown considerable success. The proposed LSER-based solvation model using nine physical descriptors of the solvent and ion provides relatively reliable fits with a mean error of 9%, and satisfies established limiting behavior of the physical event. A critical comparison of the present method with the other commonly used reactive extraction methods on an efficiency basis has been carried out