Molecular Framework of Mouse Endothelial Cell Dysfunction during Inflammation: A Proteomics Approach

A key aspect of cytokine-induced changes as observed in sepsis is the dysregulated activation of endothelial cells (ECs), initiating a cascade of inflammatory signaling leading to leukocyte adhesion/migration and organ damage. The therapeutic targeting of ECs has been hampered by concerns regarding organ-specific EC heterogeneity and their response to inflammation. Using in vitro and in silico analysis, we present a comprehensive analysis of the proteomic changes in mouse lung, liver and kidney ECs following exposure to a clinically relevant cocktail of proinflammatory cytokines. Mouse lung, liver and kidney ECs were incubated with TNF-α/IL-1β/IFN-γ for 4 or 24 h to model the cytokine-induced changes. Quantitative label-free global proteomics and bioinformatic analysis performed on the ECs provide a molecular framework for the EC response to inflammatory stimuli over time and organ-specific differences. Gene Ontology and PANTHER analysis suggest why some organs are more susceptible to inflammation early on, and show that, as inflammation progresses, some protein expression patterns become more uniform while additional organ-specific proteins are expressed. These findings provide an in-depth understanding of the molecular changes involved in the EC response to inflammation and can support the development of drugs targeting ECs within different organs. Data are available via ProteomeXchange (identifier PXD031804).     

Electrode kinetics by hydrodynamic voltammetry—study of ferrous-ferric, ferrocyanide-ferricyanide and iodide-iodine systems

Using rotated and circulatory electrolysis cells, rate parameters of electrode processes have been determined at stationary conical and cylindrical platinum microclectrodes in flowing solutions, under judiciously controlled hydrodynamic conditions. Virtually ideal laminar flow was maintained at velocities up to 700 cm/s. Normally reversible d.c. current/voltage waves were made “irreversible in shape”, due to enhancement of convective mass transfer. Thus specific electron-transfer rate constants, ranging up to an estimated limit of 10 cm/s, could be evaluated by a simple and unambiguous “wave analysis” procedure. The electro-oxidation of iodide to iodine, in perchloric acid in the absence of triiodide, is governed by second-order kinetics. A mechanism is proposed to account for this remarkable finding.     

Microbes versus microbes: control of pathogens in the food chain

Foodborne illness continues as a considerable threat to public health. Despite improved hygiene management systems and increased regulation, pathogenic bacteria still contaminate food, causing sporadic cases of illness and disease outbreaks worldwide. For many centuries, microbial antagonism has been used in food processing to improve food safety. An understanding of the mode of action of this microbial antagonism has been gained in recent years and potential applications in food and feed safety are now being explored. This review focuses on the potential opportunities presented, and the limitations, of using microbial antagonism as a biocontrol mechanism to reduce contamination along the food chain; including animal feed as its first link. © 2014 Society of Chemical Industry     

Semiconductor/Polymer Nanocomposites of Acrylates and Nanocrystalline Silicon by Laser‐Induced Thermal Polymerization

In this work, a novel method for the preparation of polymer/semiconductor nanocomposites is presented. The nanocomposite is directly prepared from a suspension of nanocrystalline silicon (nc‐Si) in bulk vinyl monomers (acrylates) and focused heating of the nc‐Si by irradiation with a pulsed laser at 532 nm wavelength. The silicon nanocrystals are the inorganic component of the composite and simultaneously act as initiation points of the free radical polymerization forming the hybrid composite. By this method, patterned nanocomposite films with thicknesses up to ≈250 µm can be readily prepared. Furthermore, the polymerization kinetics were investigated for different reaction conditions such as irradiation time, laser intensity, nc‐Si content, and addition of radical initiators.

     

Applications of analytical electron microscopy to guide the design of boron carbide

Compositional analysis of boron carbide on nanometer length scales to examine or interpret atomic mechanisms, for example, solid-state amorphization or grain-boundary segregation, is challenging. This work reviews advancements in high-resolution microanalysis to characterize multiple generations of boron carbide. First, ζ-factor microanalysis will be introduced as a powerful (scanning) transmission electron microscopy ((S)TEM) analytical framework to accurately characterize boron carbide. Three case studies involving the application of ζ-factor microanalysis will then be presented: (1) accurate stoichiometry determination of B-doped boron carbide using ζ-factor microanalysis and electron energy loss spectroscopy, (2) normalized quantification of silicon grain-boundary segregation in Si-doped boron carbide, and (3) calibration of a scanning electron microscope X-ray energy-dispersive spectroscopy (XEDS) system to measure compositional homogeneity differences of B/Si-doped arc-melted boron carbides in the as-melted and annealed conditions. Overall, the improvement and application of advanced analytical tools have helped better understand processing–microstructure–property relationships and successfully manufacture high-performance ceramics.