Charge‐Transfer Interactions: An Efficient Tool for Recycling Bis(oxazoline)‐Copper Complexes in Asymmetric Henry Reactions

An anthracenyl‐modified chiral bis(oxazoline) copper complex has been demonstrated to efficiently promote nitroaldol reactions between structurally varying aldehydes and nitromethane or nitroethane. The catalyst was recovered through formation of a charge transfer complex between the chiral ligand and trinitrofluorenone and its subsequent precipitation with pentane. The efficiency of this procedure was proved through several consecutive catalytic cycles that allowed the sturdy formation of the expected product with a high enantioselectivity. The catalyst′s stability was also put to the test in an original multi‐substrate procedure. Following the same recovery concept, a new heterogeneous procedure was tested for which trinitrofluorenone was covalently linked to a silica support. Asymmetric heterogeneous catalysis was performed under these conditions as one of the few examples demonstrating the potential catalyst recycling in nitroaldol reactions through reversible, non‐covalent interactions.     

Impact of biofouling on diffusive gradient in thin film measurements in water

The technique of diffusive gradient in thin film (DGT) is commonly used to assess metal contamination in natural waters. In this paper, we assess the effect of biofouling on DGT measured labile concentrations in water and investigate whether an additional nuclepore polycarbonate membrane on the surface of DGT devices can limit biofilm growth. Simultaneous field deployments of DGT equipped with and without the additional membrane in a canal receiving wastewater were compared. The effect of the biofilm was also assessed in controlled laboratory experiments, completed by the experimental determination of several metals diffusion coefficients in the hydrogel and membrane systems. The biofilms effect was problematic only from the 10th day of accumulation. Accumulation of some elements is highly biased by the presence of a thick biofilm (Zn, Ni, Cd). The polycarbonate membrane improved the quantification of Cd and Ni but adversely affects the quantification of Cr and Co. A kinetic model is proposed to explain the biofilm role on the DGT measurement. Depending on the metals of interest, it is possible to limit bias due to biofilms by using an additional polycarbonate membrane.     

Risk and protection factors in fatal accidents

This paper aims at addressing the interest and appropriateness of performing accident severity analyses that are limited to fatal accident data. Two methodological issues are specifically discussed, namely the accident-size factors (the number of vehicles in the accident and their level of occupancy) and the comparability of the baseline risk. It is argued that - although these two issues are generally at play in accident severity analyses - their effects on, e.g., the estimation of survival probability, are exacerbated if the analysis is limited to fatal accident data. As a solution, it is recommended to control for these effects by (1) including accident-size indicators in the model, (2) focusing on different sub-groups of road-users while specifying the type of opponent in the model, so as to ensure that comparable baseline risks are worked with. These recommendations are applied in order to investigate risk and protection factors of car occupants involved in fatal accidents using data from a recently set up European Fatal Accident Investigation database (Reed and Morris, 2009). The results confirm that the estimated survival probability is affected by accident-size factors and by type of opponent. The car occupants’ survival chances are negatively associated with their own age and that of their vehicle. The survival chances are also lower when seatbelt is not used. Front damage, as compared to other damaged car areas, appears to be associated with increased survival probability, but mostly in the case in which the accident opponent was another car. The interest of further investigating accident-size factors and opponent effects in fatal accidents is discussed.     

Metabolic effects in mice of cream processing: Direct ultra-high-temperature process lowers high-fat-induced adipose tissue inflammation

Although UHT heat treatment is being optimized to improve the stability and functional properties of dairy products, its metabolic effects remain scarcely known. As such, we studied the effect of the type of UHT process on lipid metabolism, intestinal barrier, and inflammation in mice. Nine-week-old male C57Bl/6J mice were fed a diet composed of nonlipidic powder mixed with different UHT dairy creams (final: 13% milkfat) for 1 or 4 wk. All creams contained 0.02% of thickener (carrageenan) and were treated via either (1) classical indirect heating process (Th), (2) indirect process at higher temperature (Th+), or (3) direct process by steam injection (ThD). Plasma, epididymal adipose tissue (EAT), and intestine were analyzed. Multivariate principal component analyses were used to identify differential effects of processes. Th+ differed by a globally higher liver damage score compared with that of the other creams. After 4 wk, the duodenal expression of lipid absorption genes fatty acid binding protein 4 (Fatp4) and microsomal triglycerides transfer protein (Mttp) was lower in the Th+ versus Th group. Expression in the colon of tight junction protein zonula occludens 1 (Zo1) and of some endoplasmic reticulum stress markers was lower in both Th+ and ThD versus the Th group. In EAT, ThD had lower gene expression of several inflammatory markers after 4 wk. Some differential effects may be related to heat-induced physicochemical changes of creams. The type of cream UHT process differentially affected metabolic parameters in mice after a 4-wk fat-rich diet, partly due to cream structure. Altogether, direct steam injection process induced the lowest early markers of high-fat-induced metabolic inflammation in EAT.     

Metabolic effects in mice of cream formulation: Addition of both thickener and emulsifier does not alter lipid metabolism but modulates mucus cells and intestinal endoplasmic reticulum stress

Additives stabilize or improve the organoleptic or functional properties (or both) of many dairy products including whipping cream. Their influence on the metabolic effect of dairy cream is scarcely known. We tested the hypothesis that added emulsifier (lactic acid esters of mono- and diglycerides; MAG/DAG), thickener (carrageenan, CGN), or both, could modify the metabolic effect, notably in the intestine and liver. Nine-week-old male C57Bl/6J mice were fed UHT cream (indirect treatment) mixed with nonlipidic powder (final: 13% milkfat) for 1 or 4 wk. We compared creams (1) without additive (Ctl), (2) with thickener (Th), 0.02% of κ-CGN, and (3) with both thickener and emulsifier, 0.1% of MAG/DAG esters (Th/Em). We analyzed plasma parameters, intestine, and liver. Fasting glycemia, insulinemia, triglyceridemia, nonesterified fatty acids, body weight gain, and liver weight did not differ among groups. After 1 wk, Th/Em had higher expression in the duodenum of some of the genes involved in (1) intestinal lipid absorption and (2) tight junction proteins versus Ctl and Th. After 4 wk, mucus cell number in the small intestine was higher in Th/Em versus Ctl and Th. Genes involved in endoplasmic reticulum (ER) stress in the duodenum were more expressed in Th/Em after 1 wk. After 4 wk, in the colon, a higher expression of ER stress genes was observed for Th versus Th/Em and Ctl. Liver damage score was not altered by additives. Adding both CGN (0.02%) and MAG/DAG esters (0.1%) in dairy cream did not result in deleterious outcomes in mice after 4 wk regarding lipid metabolism, intestinal permeability, and liver disorders. The longer term effect of intestinal ER stress modulation deserves further investigation.     

The formation and evolution of oxide particles in oxide-dispersion-strengthened ferritic steels during processing

The fabrication of oxide-dispersion-strengthened (ODS) steels is a multi-stage process involving powder ball milling, degassing and consolidation by hot isostatic pressing. Y is introduced by mechanical alloying (MA) with either Y₂O₃ or Fe₂Y so a high density of Y–Ti–O-based oxide nanoparticles is formed. The evolution of ～2 nm oxide nanoparticles and larger >5 nm grain boundary oxides has been studied at each step of the processing. The nanoparticle dispersions produced in material MA with Fe₂Y were comparable to those produced by alloying with Y₂O₃. Hence the majority of oxygen which forms the nanoparticles must be incorporated from the atmosphere during MA, rather than being introduced via the alloying additions. During mechanical alloying, a high density of subnanometer particles are formed (2.5 ± 0.5 × 10²⁴ m^?3). The oxygen content of the nanoparticles decreases slightly on annealing, and then the composition of the nanoparticles remains constant throughout subsequent processing stages. The nanoparticle size increases during processing up to ～2 nm radius, while the number density decreases to 4 ± 0.5 × 10²³ m^?3. Grain boundary oxides (>5 nm) have a Ti–Cr–O-rich shell, and contain no Y before consolidation, but have similar core composition to the matrix nanoparticles after consolidation. The formation of the larger grain boundary oxides is shown to take place during the degassing and consolidation stages, and this occurs at the expense of the nanoparticles in the matrix. This work provides a mechanistic understanding of the importance of controlling the oxygen content in the powder during MA, and the resulting impact on the formation of the ODS microstructure.     

LCA tool for the environmental evaluation of potable water production

Environmental impact assessment will soon become a compulsory phase in future potable water production projects, especially when alternative treatment processes such as desalination are considered. An impact assessment tool is therefore developed for the environmental evaluation of potable water production. The evaluation method used is the life cycle assessment (LCA) method. The quick and easy assessment of energetic and environmental performances contributes to determine the weak points of potable water production processes or the best suited treatment in a specific context. Studies of some potable water supply scenarios (groundwater treatment, ultrafiltration, nanofiltration, seawater reverse osmosis and thermal distillation associated to water transfer) are presented in order to illustrate the environmental information drawn from this tool. The main source of impacts is shown to be electricity production for plant operation. Improvement levers are presented for impact reduction and for the objective comparison between alternative and conventional water treatment processes.     

Matrix-assisted laser desorption/ionization-ion mobility separation-mass spectrometry imaging of vinblastine in whole body tissue sections

During early-stage drug development, drug and metabolite distribution studies are carried out in animal tissues using a range of techniques, particularly whole body autoradiography (WBA). While widely employed, WBA has a number of limitations, including the following: expensive synthesis of radiolabeled drugs and analyte specificity and identification. WBA only images the radiolabel. MALDI MSI has been shown previously to be advantageous for imaging the distribution of a range of drugs and metabolites in whole body sections. Ion mobility separation (IMS) adds a further separation step to imaging experiments; demonstrated here is MALDI-IMS-MS whole body imaging of rats dosed at 6 mg/kg i.v. with an anticancer drug, vinblastine and shown is the distribution of the precursor ion m/z 811.4 and several product ions including m/z 793, 751, 733, 719, 691, 649, 524, and 355. The distribution of vinblastine within the ventricles of the brain is also depicted. Clearly demonstrated in these data are the removal of interfering isobaric ions within the images of m/z 811.4 and also of the transition m/z 811-751, resulting in a higher confidence in the imaging data. Within this work, IMS has shown to be advantageous in both MS and MS/MS imaging experiments by separating vinblastine from an endogenous isobaric lipid.