Post-mortem volatiles of vertebrate tissue

Volatile emission during vertebrate decay is a complex process that is understood incompletely. It depends on many factors. The main factor is the metabolism of the microbial species present inside and on the vertebrate. In this review, we combine the results from studies on volatile organic compounds (VOCs) detected during this decay process and those on the biochemical formation of VOCs in order to improve our understanding of the decay process. Micro-organisms are the main producers of VOCs, which are by- or end-products of microbial metabolism. Many microbes are already present inside and on a vertebrate, and these can initiate microbial decay. In addition, micro-organisms from the environment colonize the cadaver. The composition of microbial communities is complex, and communities of different species interact with each other in succession. In comparison to the complexity of the decay process, the resulting volatile pattern does show some consistency. Therefore, the possibility of an existence of a time-dependent core volatile pattern, which could be used for applications in areas such as forensics or food science, is discussed. Possible microbial interactions that might alter the process of decay are highlighted

Antiviral Silencing and Suppression of Gene Silencing in Plants

RNA silencing is an evolutionary conserved sequence-specific gene inactivation mechanism that contributes to the control of development, maintains heterochromatin, acts in stress responses, DNA repair and defends against invading nucleic acids like transposons and viruses. In plants RNA silencing functions as one of the main immune systems. RNA silencing process involves the small RNAs and trans factor components like Dicers, Argonautes and RNA-dependent RNA poly- merases. To deal with host antiviral silencing responses viruses evolved mecha- nisms to avoid or counteract this, most notably through expression of viral suppressors of RNA silencing. Due to the overlap between endogenous and antiviral silencing pathways while blocking antiviral pathways viruses also impact endogenous silencing processes. Here we provide an overview of antiviral silencing pathway, host factors implicated in it and the crosstalk between antiviral and endogenous branches of silencing. We summarize the current status of knowledge about the viral counter-defense strategies acting at various steps during virus infection in plants with the focus on representative, well studied silencing suppres- sor proteins. Finally we discuss future challenges of the antiviral silencing and counter-defense research field

Hybrid chalcogenide nanoparticles: 2D-WS2 nanocrystals inside nested WS2 fullerenes

The MOCVD assisted formation of nested WS2 inorganic fullerenes (IF-WS2) was performed by enhancing surface diffusion with iodine, and fullerene growth was monitored by taking TEM snapshots of intermediate products. The internal structure of the core-shell nanoparticles was studied using scanning electron microscopy (SEM) after cross-cutting with a focused ion beam (FIB). Lamellar reaction intermediates were found occluded in the fullerene particles. In contrast to carbon fullerenes, layered metal chalcogenides prefer the formation of planar, plate-like structures where the dangling bonds at the edges are stabilized by excess S atoms. The effects of the reaction and annealing temperatures on the composition and morphology of the final product were investigated, and the strength of the WS2 shell was measured by intermittent contact-mode AFM. The encapsulated lamellar structures inside the hollow spheres may lead to enhanced tribological activities

Interaction of Alkaline Metal Cations with Oxidic Surfaces: Effect on the Morphology of SnO2 Nanoparticles

Reaction pathways to SnO2 nanomaterials through the hydrolysis of hydrated tin tetrachloride precursors were investigated. The products were prepared solvothermally starting from hydrated tin tetrachloride and various (e.g., alkali) hydroxides. The influence of the precursor base on the final morphology of the nanomaterials was studied. X-ray powder diffraction (XRD) data indicated the formation of rutile-type SnO2. Transmission electron microscopy (TEM) studies revealed different morphologies that were formed with different precursor base cations. Data from molecular dynamics (MD) simulations provide theoretical evidence that the adsorption of the cations of the precursor base to the faces of the growing SnO2 nanocrystals is crucial for the morphology of the nanostructures. RI Birkel, Alexander/D-6123-2011; Tremel, Wolfgang/D-8125-2011; Mugnaioli, Enrico/E-6237-2011; Loges, Niklas/F-2479-201

Interaction of Alkaline Metal Cations with Oxidic Surfaces: Effect on the Morphology of SnO2 Nanoparticles

Reaction pathways to SnO2 nanomaterials through the hydrolysis of hydrated tin tetrachloride precursors were investigated. The products were prepared solvothermally starting from hydrated tin tetrachloride and various (e.g., alkali) hydroxides. The influence of the precursor base on the final morphology of the nanomaterials was studied. X-ray powder diffraction (XRD) data indicated the formation of rutile-type SnO2. Transmission electron microscopy (TEM) studies revealed different morphologies that were formed with different precursor base cations. Data from molecular dynamics (MD) simulations provide theoretical evidence that the adsorption of the cations of the precursor base to the faces of the growing SnO2 nanocrystals is crucial for the morphology of the nanostructures. © 2009 American Chemical Society

The early allergic response in small airways of human precision-cut lung slices

The early allergic response in small airways of human precision-cut lung slice