Notes

High-throughput hit-squad tackle trypanosomes.
Polychlorinated dioxins and dibenzofurans (PCDD/Fs) are highly toxic contaminants that are strictly regulated and monitored in the environment and food to reduce human exposure. Recently, the increasing occurrence of polybrominated dioxins and dibenzofurans (PBDD/Fs) in the environment is raising concerns about the impact on human health by the combined exposure to chlorinated and brominated analogues of dioxins. Toxicological properties of PBDD/Fs relative to PCDD/Fs have not been firmly established, and brominated dioxins are not included in routine monitoring programs. In this study, we set out to determine human-relevant congener-specific potency values for a range of brominated and chlorinated dioxin congeners, based on their aryl hydrocarbon receptor (AhR)-mediated mode of toxic action. Transactivation of the AhR was measured using dioxin-responsive (DR) CALUX reporter gene assays. Because of known species-differences in dioxin-mediated toxicity, we developed and used a HepG2 human liver cell-based DR human CALUX assay that is a variant of the rodent-based DR CALUX. CAY10444 manufacturer The assay was found to be highly inducible and stable, with low variations between independent measurements. Using both DR CALUX assays in an automated high-throughput mode we found that overall PBDD/Fs were as potent as PCDD/Fs in inducing AhR transactivation, but congener-specific differences were observed. We also observed species-specific differences in sensitivity and potency when comparing DR human REP values to those obtained in the rat-based DR CALUX. Finally, we observed significant differences between WHO-TEF values and DR human REP values, suggesting that actual WHO-TEF values may underestimate the hazards associated with exposure of humans to dioxins.Soil contaminated by combinations of heavy metals and organic pollutants has become an increasingly prominent environmental issue. Developing efficient technologies to synchronously decontaminate such co-contaminated sites is challenging and imperative. In our previous study for the treatment of Copper (Cu) and pyrene contaminated soil, electrokinetics (EK) coupled acidic permanganate (PM) performed best for degradation of pyrene near the injection spot, but it unfortunately prevented the migration of Cu. In order to further enhance the removal efficiency of these contaminants, in this study, batch experiments were conducted to investigate the feasibility of delivering PM by EK under regular refreshment of acidoxidant along with amplification of voltage gradient. The results showed that PM can be transported from cathode to anode to S2 section (near the anode) with a slow mass transfer rate via electromigration and reversed electroosmotic flow, and further delivery was achieved when Cu and pyrene were coexisted. The reaction of pyrene with PM produced a lower soil pH condition, which was conductive to the transport of Cu, and the existence of Cu promoted the migration of PM. The coexistence of Cu and pyrene favored the removal efficiency of the pollutants, and 92.8% of Cu and 70.7% of pyrene were removed after 15 d EK treatment. Thus, EK + acidic PM with regularly supplement of oxidant is appropriate to achieve complete mass depletion of heavy metals and PAHs, especially in low buffered soils.It is unclear how biochar can affect P availability in soil, especially in field under continuous application. In this study, a field experiment was conducted to study the effect of 2-years application of biochar on P availability, P fractionation, P sorption and release in a clay soil. The biochar in this study was produced from rice straw through pyrolysis at 700°C. As compared with no fertilizer treatment (CK) and chemical fertilizer treatment (CF), the biochar application with chemical fertilizer treatment (BCF) significantly increased total P and available P content in soil. And BCF treatment significantly increased resin P, NaHCO3-extracted P, Fe/Al-Po and HCl-extracted P but decreased Fe/Al-Pi and residual P as compared with CF treatment. Surprisingly, BCF treatment showed higher sorption capacity and release capacity of soil P than that of CF treatment. These results imply that continuous application of biochar for 2-years in field may adsorbed P through physical sorption rather than chemical reaction and then improve P availability in soil.Mechanistic insight into protein binding by poly- and perfluoroalkyl substances (PFASs) is critical to understanding how PFASs distribute and accumulate within the body and to developing predictive models within and across classes of PFASs. Fluorine nuclear magnetic resonance spectroscopy (19F NMR) has proven to be a powerful, yet underutilized tool to study PFAS binding; chemical shifts of each fluorine group reflect the local environment along the length of the PFAS molecule. Using bovine serum albumin (BSA), we report dissociation constants, Kd, for four common PFASs well below reported critical micelle concentrations (CMCs) - perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexanesulfonic acid (PFHxS), and perfluorooctanesulfonic acid (PFOS) - as a function of temperature in phosphate buffered saline. Kd values were determined based on the difluoroethyl group adjacent to the anionic headgroups and the terminal trifluoromethyl groups. Our results indicate that the hydrophobic tails exhibit greater binding affinity relative to the headgroup, and that the binding affinities are generally consistent with previous results showing that greater PFAS hydrophobicity leads to greater protein binding. However, the binding mechanism was dominated by entropic hydrophobic interactions attributed to desolvation of the PFAS tails within the hydrophobic cavities of the protein and on the surface of the protein. In addition, PFNA appears to form hemimicelles on the protein surfaces below reported CMC values. This work provides a renewed approach to utilizing 19F NMR for PFAS-protein binding studies and a new perspective on the role of solvent entropy.Distribution and elimination of petroleum products can be predicted in aerobic wastewater treatment plants (WWTPs) using models such as multimedia fate model SimpleTreat. An advantage of the SimpleTreat model is that it only requires a few basic properties of a chemical in wastewater to calculate partitioning, biodegradation and ultimately emissions to air, surface water and produced sludge. The SimpleTreat model structure reflects a WWTP scheme. However, refinery WWTPs typically incorporate more advanced treatment processes such as dissolved air flotation (DAF), a process that clarifies wastewaters by the removal of suspended matter such as oil or solids. The objective of this work was to develop a WWTP removal model that includes DAF treatment. To understand how including a DAF in the model affects the predicted concentrations of petroleum constituents in effluent, we replaced the primary sedimentation module in SimpleTreat with a module simulating DAF. Subsequently, we compared results from the WWTP-DAF model with results obtained with the original SimpleTreat model for a library of over 1500 representative hydrocarbon constituents.
My Website: https://www.selleckchem.com/products/cay10444.html