Bacteria homologus to Aeromonas capable of microcystin degradation

Water blooms dominated by cyanobacteria are capable of producing hepatotoxins known as microcystins. These toxins are dangerous to people and to the environment. Therefore, for a better understanding of the biological termination of this increasingly common phenomenon, bacteria with the potential to degrade cyanobacteria-derived hepatotoxins and the degradative activity of culturable bacteria were studied. Based on the presence of the mlrA gene, bacteria with a homology to the Sphingopyxis and Stenotrophomonas genera were identified as those presenting potential for microcystins degradation directly in the water samples from the Sulejów Reservoir (SU, Central Poland). However, this biodegrading potential has not been confirmed in in vitro experiments. The degrading activity of the culturable isolates from the water studied was determined in more than 30 bacterial mixes. An analysis of the biodegradation of the microcystin-LR (MC-LR) together with an analysis of the phylogenetic affiliation of bacteria demonstrated for the first time that bacteria homologous to the Aeromonas genus were able to degrade the mentioned hepatotoxin, although the mlrA gene was not amplified. The maximal removal efficiency of MC-LR was 48%. This study demonstrates a new aspect of interactions between the microcystin-containing cyanobacteria and bacteria from the Aeromonas genus.The authors would like to acknowledge the European Cooperation in Science and Technology, COST Action ES 1105 “CYANOCOST - Cyanobacterial blooms and toxins in water resources: Occurrence, impacts and management” for adding value to this study through networking and knowledge sharing with European experts and researchers in the field. The Sulejów Reservoir is a part of the Polish National Long- Term Ecosystem Research Network and the European LTER site

Influence of the Cu-Te composition and microstructure on the resistive switching of Cu-Te/Al(2)O(3)/Si cells

In this letter, we explore the influence of the Cu(x)Te(1-x) layer composition (0.2 0.7 leads to large reset power, similar to pure-Cu electrodes, x < 0.3 results in volatile forming properties. The intermediate range 0.5< x < 0.7 shows optimum memory properties, featuring improved control of filament programming using <5 mu A as well as state stability at 85 degrees C. The composition-dependent programming control and filament stability are closely associated with the phases in the Cu(x)Te(1-x) layer and are explained as related to the chemical affinity between Cu and Te. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3621835

Introduction of WO3 Layer in a Cu-Based Al2O3 Conductive Bridge RAM System for Robust Cycling and Large Memory Window

In this paper, we optimize a WO3\Al2O3 bilayer serving as the electrolyte of a conductive bridge RAM device using a Cu-based supply layer. By introducing a WO3 layer formed by thermal oxidation of a W plug, the hourglass shape of the conductive filament is desirably controlled, enabling excellent switching behavior. We demonstrate a clear improvement of the microstructure and density of the WO3 layer by increasing the oxidation time and temperature, resulting in a strong increase of the high-resistance-state breakdown voltage. The high quality WO3 microstructure allows thus the use of a larger reset pulse amplitude resulting both in larger memory window and failure-free write cycling.1197Ysciescopu

Te-based chalcogenide materials for selector applications

The implementation of dense, one-selector one-resistor (1S1R), resistive switching memory arrays, can be achieved with an appropriate selector for correct information storage and retrieval. Ovonic threshold switches (OTS) based on chalcogenide materials are a strong candidate, but their low thermal stability is one of the key factors that prevents rapid adoption by emerging resistive switching memory technologies. A previously developed map for phase change materials is expanded and improved for OTS materials. Selected materials from different areas of the map, belonging to binary Ge-Te and Si-Te systems, are explored. Several routes, including Si doping and reduction of Te amount, are used to increase the crystallization temperature. Selector devices, with areas as small as 55 x 55 nm(2), were electrically assessed. Sub-threshold conduction models, based on Poole-Frenkel conduction mechanism, are applied to fresh samples in order to extract as-processed material parameters, such as trap height and density of defects, tailoring of which could be an important element for designing a suitable OTS material. Finally, a glass transition temperature estimation model is applied to Te-based materials in order to predict materials that might have the required thermal stability. A lower average number of p-electrons is correlated with a good thermal stability

Anomalous diffusion and Tsallis statistics in an optical lattice

We point out a connection between anomalous quantum transport in an optical lattice and Tsallis' generalized thermostatistics. Specifically, we show that the momentum equation for the semiclassical Wigner function that describes atomic motion in the optical potential, belongs to a class of transport equations recently studied by Borland [PLA 245, 67 (1998)]. The important property of these ordinary linear Fokker--Planck equations is that their stationary solutions are exactly given by Tsallis distributions. Dissipative optical lattices are therefore new systems in which Tsallis statistics can be experimentally studied.Comment: 4 pages, 1 figur

Microscopic origin of random telegraph noise fluctuations in aggressively scaled RRAM and its impact on read disturb variability

Random telegraph noise (RTN) is an important intrinsic phenomenon of any logic or memory device that is indicative of the reliability and stochastic variability in its performance. In the context of the resistive random access memory (RRAM), RTN becomes a key criterion that determines the read disturb immunity and memory window between the low (LRS) and high resistance states (HRS). With the drive towards ultra-low power memory (low reset current) and aggressive scaling to 10 × 10 nm2 area, contribution of RTN is significantly enhanced by every trap (vacancy) in the dielectric. The underlying mechanisms governing RTN in RRAM are yet to be fully understood. In this study, we aim to decode the role of conductance fluctuations caused by oxygen vacancy transport and inelastic electron trapping and detrapping processes. The influence of resistance state (LRS, shallow and deep HRS), reset depth and reset stop voltage (VRESET-STOP) on the conductance variability is also investigated. © 2013 IEEE

The effect of deformation conditions on the rheological properties of the Al 5754 alloy

The article presents the results of rheological testing of Al 5754 alloy in series 5xxx, obtained for deformation parameters corresponding to the process of extrusion of large-size sections on presses. The effect of deformation conditions on the variations in yield stress magnitude was determined. Then, using the least squares method., the actual values of the coefficients of the mathematical model describing the rheological properties of the material under investigation were determined, thus obtaining grounds for conducting the model studies of the extrusion process based on numerical methods

Long-term follow-up of MCL patients treated with single-agent ibrutinib: updated safety and efficacy results

Ibrutinib, an oral inhibitor of Bruton tyrosine kinase, is approved for patients with mantle cell lymphoma (MCL) who have received one prior therapy. We report the updated safety and efficacy results from the multicenter, open-label phase 2 registration trial of Ibrutinib (median 26.7-month follow-up). Patients (N = 111) received oral ibrutinib 560 mg once daily, and those with stable disease or better could enter a long-term extension study. The primary end point was overall response rate (ORR). The median patient age was 68 years (range, 40-84), with a median of 3 prior therapies (range, 1-5). The median treatment duration was 8.3 months; 46% of patients were treated for \u3e12 months, and 22% were treated for \u3e= 2 years. The ORR was 67% (23% complete response), with a median duration of response of 17.5 months. The 24-month progression-free survival and overall survival rates were 31% (95% confidence interval [Cl], 22.3-40.4) and 47% (95% Cl, 37.1-56.9), respectively. The most common adverse events (AEs) in \u3e30% of patients included diarrhea (54%), fatigue (50%), nausea (33%), and dyspnea (32%). The most frequent grade \u3e= 3 infections included pneumonia (8%), urinary tract infection (4%), and cell ulitis (3%). Grade bleeding events in \u3e= 2% of patients were hematuria (2%) and subdural hematoma (2%). Common all-grade hematologic AEs were thrombocytopenia (22%), neutropenia (19%), and anemia (18%). The prevalence of infection, diarrhea, and bleeding was highest for the first 6 months of therapy and less thereafter. With longer follow-up, ibrutinib continues to demonstrate durable responses and favorable safety in relapsed/refractory MCL. The trial is registered to www.ClinicalTrials.gov as #NCT01236391