Effect of Separate and Combined Toxicity of Bisphenol A and Zinc on the Soil Microbiome

The research objective was established by taking into account common sources of soil contamination with bisphenol A (B) and zinc (Zn²⁺), as well as the scarcity of data on the effect of metabolic pathways involved in the degradation of organic compounds on the complexation of zinc in soil. Therefore, the aim of this study was to determine the spectrum of soil homeostasis disorders arising under the pressure of both the separate and combined toxicity of bisphenol A and Zn²⁺. With a broad pool of indicators, such as indices of the effect of xenobiotics (IF_X), humic acid (IF_H), plants (IF_P), colony development (CD), ecophysiological diversity (EP), the Shannon–Weaver and the Simpson indices, as well as the index of soil biological fertility (BA₂₁), the extent of disturbances was verified on the basis of enzymatic activity, microbiological activity, and structural diversity of the soil microbiome. A holistic character of the study was achieved, having determined the indicators of tolerance (IT) of Sorghum Moench (S) and Panicum virgatum (P), the ratio of the mass of their aerial parts to roots (PR), and the SPAD leaf greenness index. Bisphenol A not only failed to perform a complexing role towards Zn²⁺, but in combination with this heavy metal, had a particularly negative effect on the soil microbiome and enzymatic activity. The NGS analysis distinguished certain unique genera of bacteria in all objects, representing the phyla Actinobacteriota and Proteobacteria, as well as fungi classified as members of the phyla Ascomycota and Basidiomycota. Sorghum Moench (S) proved to be more sensitive to the xenobiotics than Panicum virgatum (P).     

Laser ablation inductively coupled plasma mass spectrometry assisted insight into ion-selective membranes

Laser ablation inductively coupled plasma mass spectrometry was used to evaluate ion depth profiles across ion-selective membranes. Advantageously, this approach does not require incorporation of additional components (e.g., chromoionophore) in the membrane composition, as compared to that used in typical potentiometric applications. Moreover, comparison of the distribution of ions in differently pretreated membranes is possible. Concentration profiles of primary and interfering agent (Na+) ions were recorded, for example, of Pb2+-selective poly(vinyl chloride)-based membranes. It was found that the contents and the distribution of Pb(2+) and Na+ ions across the membrane is strongly dependent on the composition of the solutions to which both sides of the membrane are exposed during preconditioning and on the plasticizer included in the membrane formulation. Typical plasticizers, bis(2-ethylhexyl sebacate) (DOS) and the more polar 2-nitrophenyl octyl ether (o-NPOE), were used. It was found that faster ion transport occurs for o-NPOE, and the membrane saturation with Pb2+ ions was achieved within less than 20 h for a 400-microm-thick membrane. In the case of the less polar plasticizer DOS, due to slower rate of ion transport, even after 20 h, the Pb2+ concentration gradients were still visible within the membrane. On the basis of concentration profiles, primary ion diffusion coefficients in both membranes were calculated, and the value obtained for o-NPOE containing membrane was found to be approximately 2 times higher than for its DOS-plasticized counterpart.     

A DNA-Micropatterned Surface for Propagating Biomolecular Signals by Positional on-off Assembly of Catalytic Nanocompartments

Signal transduction is pivotal for the transfer of information between and within living cells. The composition and spatial organization of specified compartments are key to propagating soluble signals. Here, a high-throughput platform mimicking multistep signal transduction which is based on a geometrically defined array of immobilized catalytic nanocompartments (CNCs) that consist of distinct polymeric nanoassemblies encapsulating enzymes and DNA or enzymes alone is presented. The dual role of single entities or tandem CNCs in providing confined but communicating spaces for complex metabolic reactions and in protecting encapsulated compounds from denaturation is explored. To support a controlled spatial organization of CNCs, CNCs are patterned by means of DNA hybridization to a microprinted glass surface. Specifically, CNC-functionalized DNA microarrays are produced where individual reaction compartments are kept in close proximity by a distinct geometrical arrangement to promote effective communication. Besides a remarkable versatility and robustness, the most prominent feature of this platform is the reversibility of DNA-mediated CNC-anchoring which renders it reusable. Micropatterns of polymer-based nanocompartment assemblies offer an ideal scaffold for the development of the next generation responsive and communicative soft-matter analytical devices for applications in catalysis and medicine.     

ARS: an integrated package for shared-variable and message-passing computations in object-based systems

This paper describes the ARS library package, which supports two implementation versions of an object-based system: a shared-variable and a message-passing version. The two versions have the same object structure and synchronisation but differ in their process structure and inter-process communication models. Thus, the mechanisms related to the uniform features are common for the two versions, but the process multiplexing mechanisms differ. As a consequence, the performance characteristics of the two versions of a system related to uniform features are similar, while those related to the process multiplexing differ significantly. We present an overview of the computational model supported by the ARS package, the internal structure of the package and compare overheads in two versions of an object-based system supported by the package. © 1998 John Wiley & Sons, Ltd.     

Optical and Mechanical Properties of Thin PTFE Films,Deposited from a Gas Phase

Thin polytetrafluoroethylene (PTFE) films are produced by deposition from a gas phase by two methods: electron-enhanced vacuum deposition (EVD) and EVD + low-temperature plasma (LTP). Structure, morphology, and composition of the films are studied by IR spectroscopy, atomic force microscopy, and X-ray photoelectron spectroscopy. They are close to the structure of bulk PTFE. The roughness of the films’ surface is changed with gas pressure and LTP power variations. Films are transparent from UV to near-infrared regions. Refractive and extinction indices and their anisotropy are measured by spectral ellipsometry. They are tuned by variations of deposition conditions. Hardness and Young modulus of the films are increased if EVD + low power LTP is used for film deposition. Use of EVD + LTP also increases thermal stability of the films. Contact angle of the films corresponds to the bulk PTFE. The PTFE molecules oriented are preferentially in perpendicular direction to the substrate surface.