Anti-Estradiol monoclonal antibody, clone N506344

The aim of the present study was to develop a generic rat physiologically based kinetic (PBK) model that includes a novel testing strategy where active biliary excretion is incorporated using estradiol-17 beta glucuronide (E(2)17 beta G) as the model substance. A major challenge was the definition of the scaling factor for the in vitro to in vivo conversion of the PBK-model parameter V-max. In vitro values for the V-max and K-m for transport of E(2)17 beta G were found in the literature in four different studies based on experiments with primary rat hepatocytes. The required scaling factor was defined based on fitting the PBK model-based predicted values to reported experimental data on E(2)17 beta G blood levels and cumulative biliary E(2)17 beta G excretion. This resulted in a scaling factor of 129 mg protein/g liver. With this scaling factor the PBK model predicted the in vivo data for blood and cumulative biliary E(2)17 beta G levels with on average of less than 1.8-fold deviation. The study provides a proof of principle on how biliary excretion can be included in a generic PBK model using primary hepatocytes to define the kinetic parameters that describe the biliary excretion.

The discharge and consequent occurrence of antibiotics in the environment has led to increasing concerns because their presence can promote the development of resistance genes, which in turn pose a significant health risk. A key process to control the transport and risk of antibiotics is adsorption. Thus, we investigated the adsorption mechanisms of six typical antibiotics onto a MnFe2O4@cellulose activated carbon (CAC) hybrid combining batch adsorption experiments and quantum chemical calculations. In the single-adsorbate adsorption systems, the solid-phase concentrations of the adsorbates varied from 152.8 to 395.7 mg/g, which were dependent on the adsorption affinity and molecular structures or sizes of the antibiotics. Chemisorption was the main adsorption mechanism, and it was driven by p-d electronic conjugation and cation-n interactions. In the competitive adsorption systems, the solid-phase concentrations of both primary (sulfamethazi ne, SMT) and secondary (the other five antibiotics) adsorbates decreased significantly. The decrease ratio of SMT varied from 15.42% to 67.28% while that of the secondary adsorbates varied from 14.13% to 52.74%. The "competition" strength was depended on the adsorption energy and the overlapping of adsorption sites. We believe that these findings will provide a better understanding of the adsorption characteristics of typical antibiotics and facilitate the strategy developing for the removal of antibiotics from the aqueous phase. (C) 2020 Elsevier B.V. All rights reserved.