Mathematical Modeling of Theoretical Cryptosporidium Inactivation in Full-Scale Ozonation Reactors

Conditions for theoretical inactivation of Cryptosporidium by ozone could be achieved at full-scale facilities if their design is appropriate. To perform this task correctly the chemical engineer's approach for process design must be applied. This paper discusses the basic equations the estimation of the disinfection efficiency of different ozone reacting systems. Available kinetic data have been integrated in a global model accounting for the hydrodynamics and mass transfer performances of the ozonation reactor. Thus the proposed method allows one to predict Cryptosporidium inactivation level in a given ozonation system. However, if a specified disinfection goal is to be achieved for Cryptosporidium with the developed model it is also possible to choose and optimize the design of the ozone reactor.     

Digital screening methodology for the directed evolution of transglycosidases

Engineering of glycosidases with efficient transglycosidasesactivity is an alternative to glycosyltransferases or glycosynthasesfor the synthesis of oligosaccharides and glycoconjugates. However,the engineering of transglycosidases by directed evolution methodologiesis hampered by the lack of efficient screening systems for sugar-transferactivity. We report here the development of digital imaging-basedhigh-throughput screening methodology for the directed evolutionof glycosidases into transgalactosidases. Using this methodology,we detected transglycosidase mutants in intact Escherichia colicells by digital imaging monitoring of the activation of non-or low-hydrolytic mutants by an acceptor substrate. We screenedseveral libraries of mutants of β-glycosidase from Thermusthermophilus using this methodology and found variants withup to a 70-fold overall increase in the transglycosidase/hydrolysisactivity ratio. Using natural disaccharide acceptors, thesetransglycosidase mutants were able to synthesise trisaccharides,as a mixture of two regioisomers, with up to 76% yield.     

Dislocations at Prismatic Fracture Surfaces in Sapphire

Single-crystal sapphire exhibits a highly anisotropic fracture behavior. The surfaces of specimens fractured along prismatic planes are wavy, with fractographic features appearing as small areas of contrast under an optical microscope. Optical microscopy, atomic force microscopy, X-ray topography, and confocal microscopy are used to demonstrate a correlation between the areas of contrast and dislocations penetrating the sample surface. The surface features are argued to be a consequence of the stress field surrounding the dislocations, which deflect the crack approximately 10 nm normal to the surface as the crack cuts the dislocations. The lateral extent of measurable surface deflection is of the order of 5 μm. These images can be compared directly to show the equivalence of the position of the dislocations observed by X-ray topography and the surface contrast observed optically.     

Contribution to the textural characterisation of Filtrasorb 400 and other commercial activated carbons commonly used for water treatment

The textural characteristics of three commercial activated carbons, Filtrasorb 400 (F400), Industrial React High Affinity and Picabiol, commonly used in water treatment, are reinvestigated. Nitrogen physisorption isotherms are determined in the range P/P ₀ = [4 × 10⁻⁷–0.998] and processed using BET, α_S (Sing), Dubinin–Radushkevich and Density Functional Theory methods. In addition, fractal dimensions are determined by the Frenkel–Halsey–Hill procedure. Since F400 is often considered as a reference material in studies on the adsorption of solutes in aqueous solutions, a review of the textural characteristics of this carbon is carried out. The results obtained in this work using the different methods are consistent and a critical crossed comparison of these results allows discussing the limitations of the methods used. In particular, the impact of the P/P ₀ range considered on S _BET value is examined. In addition, the accuracy of the BET specific surface area is assessed in the light of information from recent literature.     

Numerical Modeling of Inclusion Behavior in Liquid Metal Processing

Thermomechanical performance of metallic alloys is directly related to the metal cleanliness that has always been a challenge for metallurgists. During liquid metal processing, particles can grow or decrease in size either by mass transfer with the liquid phase or by agglomeration/fragmentation mechanisms. As a function of numerical density of inclusions and of the hydrodynamics of the reactor, different numerical modeling approaches are proposed; in the case of an isolated particle, the Lagrangian technique coupled with a dissolution model is applied, whereas in the opposite case of large inclusion phase concentration, the population balance equation must be solved. Three examples of numerical modeling studies achieved at Institut Jean Lamour are discussed. They illustrate the application of the Lagrangian technique (for isolated exogenous inclusion in titanium bath) and the Eulerian technique without or with the aggregation process: for precipitation and growing of inclusions at the solidification front of a Maraging steel, and for endogenous inclusions in the molten steel bath of a gas-stirred ladle, respectively.     

Additive manufacturing of alumina parts by indirect selective laser sintering and post processing

Innovative powder preparation and post-processing techniques can be employed to obtain high density ceramic parts by means of indirect selective laser sintering. Thermally induced phase separation (TIPS) was used to produce polymer and polymer–ceramic composite particles. The effect of polymer concentration, cooling rate, stirring and alumina particles on polymer and polymer–ceramic composite particles was investigated. Homogeneous spherical alumina–polypropylene (PP) composite powder was synthesized by TIPS for selective laser sintering (SLS). Green Al₂O₃–PP component parts with a density of 34% could be produced by conventional SLS of the polymer under optimized laser power, scan speed, scan spacing and powder preheating temperature. Various post-processing techniques like pressure infiltration (PI), warm isostatic pressing (WIPing) or a combination of both were applied to increase the green density of the Al₂O₃–PP SLM parts. Infiltrating the open porosity green SLS parts with a 30 vol% alumina-powder based ethanol suspension allowed to increase the sintered density, i.e. after polymer debinding and pressureless sintering in air at 1600 °C, from 38 to 64% of the theoretical density (TD). WIPing of the SLS and SLS/infiltrated green parts at 135 °C and 64 MPa allowed raising the green density up to 93 and 83% TD and a sintered density up to 89 and 88% TD, respectively.     

Mass Spectrometry-Based Proteomics Reveal Alcohol Dehydrogenase 1B as a Blood Biomarker Candidate to Monitor Acetaminophen-Induced Liver Injury

Acute liver injury (ALI) is a severe disorder resulting from excessive hepatocyte cell death, and frequently caused by acetaminophen intoxication. Clinical management of ALI progression is hampered by the dearth of blood biomarkers available. In this study, a bioinformatics workflow was developed to screen omics databases and identify potential biomarkers for hepatocyte cell death. Then, discovery proteomics was harnessed to select from among these candidates those that were specifically detected in the blood of acetaminophen-induced ALI patients. Among these candidates, the isoenzyme alcohol dehydrogenase 1B (ADH1B) was massively leaked into the blood. To evaluate ADH1B, we developed a targeted proteomics assay and quantified ADH1B in serum samples collected at different times from 17 patients admitted for acetaminophen-induced ALI. Serum ADH1B concentrations increased markedly during the acute phase of the disease, and dropped to undetectable levels during recovery. In contrast to alanine aminotransferase activity, the rapid drop in circulating ADH1B concentrations was followed by an improvement in the international normalized ratio (INR) within 10–48 h, and was associated with favorable outcomes. In conclusion, the combination of omics data exploration and proteomics revealed ADH1B as a new blood biomarker candidate that could be useful for the monitoring of acetaminophen-induced ALI.