Development of Pre-set Counter-rotating Streamwise Vortices in Wavy Channel

KAUST Repository

Budiman, A.C.; Mitsudharmadi, Hatsari; Bouremel, Y.; Winoto, S.H.; Low, H.T.

2015-01-01

Development of counter-rotating streamwise vortices in a rectangular channel with one-sided wavy surface has been experimentally quantified using hot-wire anemometry. The wavy surface has fixed amplitude of 3.75 mm. The counter-rotating vortices are pre-set by means of a sawtooth pattern cut at the leading edge of the wavy surface. Variations of the central streamwise velocity Uc with a channel gap H = 35 mm and 50 mm (corresponding to a Reynolds number from 1600 to 4400) change the instability of the flow which can be distinguished from the velocity contours at a certain spanwise plane. The streamwise velocity contours and turbulence intensity for Reynolds number Re = 3100 and H = 35 mm show the disappearance of the mushroom-like vortices prior to turbulence near the second peak of the wavy surface, while for higher Re, this phenomenon occurs earlier. Under certain conditions, for example, for Re = 4400 and H = 50 mm, the splitting of the vortices can also be observed.

Radical Polymerization of Styrene and Styrene–Butylmethacrylate in a Counterrotating Twin Screw Extruder

NARCIS (Netherlands)

Goot, A.J. van der; Janssen, L.P.B.M.

1997-01-01

This article describes the copolymerization of styrene–butylmethacrylate (St-BMA) and the homopolymerization of styrene (St) in a counterrotating twin screw extruder. The effect of prepolymerization on both the product properties and process was studied. It turned out that the process of reactive

Radical polymerization of styrene and styrene-butylmethacrylate in a counterrotating twin screw extruder

NARCIS (Netherlands)

vanderGoot, AJ; Janssen, LPB

1997-01-01

This article describes the copolymerization of styrene-butylmethacrylate (St-BMA) and the homopolymerization of styrene (St) in a counterrotating twin screw extruder. The effect of prepolymerization on both the product properties and process was studied. It turned out that the process of reactive

An Approximate Model for the Performance and Acoustic Predictions of Counterrotating Propeller Configurations. M.S. Thesis

Science.gov (United States)

Denner, Brett William

1989-01-01

An approximate method was developed to analyze and predict the acoustics of a counterrotating propeller configuration. The method employs the analytical techniques of Lock and Theodorsen as described by Davidson to predict the steady performance of a counterrotating configuration. Then, a modification of the method of Lesieutre is used to predict the unsteady forces on the blades. Finally, the steady and unsteady loads are used in the numerical method of Succi to predict the unsteady acoustics of the propeller. The numerical results are compared with experimental acoustic measurements of a counterrotating propeller configuration by Gazzaniga operating under several combinations of advance ratio, blade pitch, and number of blades. In addition, a constant-speed commuter-class propeller configuration was designed with the Davidson method and the acoustics analyzed at three advance ratios. Noise levels and frequency spectra were calculated at a number of locations around the configuration. The directivity patterns of the harmonics in both the horizontal and vertical planes were examined, with the conclusion that the noise levels of the even harmonics are relatively independent of direction whereas the noise levels of the odd harmonics are extremely dependent on azimuthal direction in the horizontal plane. The equations of Succi are examined to explain this behavior.

Streamwise counter-rotating vortices generated by triangular leading edge pattern in flat plate boundary layer

KAUST Repository

Hasheminejad, S. M.; Mitsudharmadi, Hatsari; Winoto, S. H.; Lua, K. B.; Low, H. T.

2016-01-01

A series of flow visualizations were conducted to qualitatively study the development of streamwise counter-rotating vortices over a flat plate induced by triangular patterns at the leading edge of a flat plate. The experiments were carried out

Counter-rotating vortex pairs in the wake of a vertical axis wind turbine

Science.gov (United States)

Rolin, Vincent; Porté-Agel, Fernando

2017-04-01

Despite the rising popularity of vertical axis wind turbines, or VAWTs, the wakes behind these machines is much less well understood than those behind horizontal axis wind turbines, or HAWTs. A thorough understanding of wakes is important as they can cause turbines in wind farms to produce less power than anticipated and increase the fatigue loading on turbines due to vibrations. In order to gain a deeper understanding of the wake behind a vertical axis wind turbine in atmospheric flow stereo-PIV is implemented in a boundary-layer wind tunnel to produce snapshots of the 3-component velocity field in the wake at various downstream positions. The boundaries of the wake are readily observed due to the high velocity gradients and turbulence present here. Two pairs of counter-rotating vortices similar to those in the wake of yawed HAWTs are also observed. An examination of the momentum fluxes behind the turbine demonstrates that the mean flow induced by these vortices entrains a large quantity of momentum from the unperturbed boundary layer flow above the wake. This effect proves to play an even more significant role than turbulence in reintroducing momentum into the wake. In order to comprehend why the VAWT produces these vortices we modify the double-multiple stream-tube model typically used to predict VAWT performance to incorporate crosswind forces. The similarity between VAWT and yawed HAWT wakes is found not to be coincidental as both cases feature rotors which exert a lateral thrust on the incoming wind which leads to the creation of counter-rotating vortex pairs.

MUSE observations of the counter-rotating nuclear ring in NGC 7742

Science.gov (United States)

Martinsson, Thomas P. K.; Sarzi, Marc; Knapen, Johan H.; Coccato, Lodovico; Falcón-Barroso, Jesús; Elmegreen, Bruce G.; de Zeeuw, Tim

2018-04-01

Aims: We present results from MUSE observations of the nearly face-on disk galaxy NGC 7742. This galaxy hosts a spectacular nuclear ring of enhanced star formation, which is unusual in that it is hosted by a non-barred galaxy, and because this star formation is most likely fuelled by externally accreted gas that counter-rotates with respect to its main stellar body. Methods: We used the MUSE data to derive the star-formation history (SFH) and accurately measure the stellar and ionized-gas kinematics of NGC 7742 in its nuclear, bulge, ring, and disk regions. Results: We have mapped the previously known gas counter-rotation well outside the ring region and deduce the presence of a slightly warped inner disk, which is inclined at approximately 6° compared to the outer disk. The gas-disk inclination is well constrained from the kinematics; the derived inclination 13.7° ± 0.4° agrees well with that derived from photometry and from what one expects using the inverse Tully-Fisher relation. We find a prolonged SFH in the ring with stellar populations as old as 2-3 Gyr and an indication that the star formation triggered by the minor merger event was delayed in the disk compared to the ring. There are two separate stellar components: an old population that counter-rotates with the gas, and a young one, concentrated to the ring, that co-rotates with the gas. We recover the kinematics of the old stars from a two-component fit, and show that combining the old and young stellar populations results in the erroneous average velocity of nearly zero found from a one-component fit. Conclusions: The spatial resolution and field of view of MUSE allow us to establish the kinematics and SFH of the nuclear ring in NGC 7742. We show further evidence that this ring has its origin in a minor merger event, possibly 2-3 Gyr ago. Data used for the flux and kinematic maps (Figs. 1 and 3-5) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or

Design, Analysis, Hybrid Testing and Orientation Control of a Floating Platform with Counter-Rotating Vertical-Axis Wind Turbines

Science.gov (United States)

Kanner, Samuel Adam Chinman

The design and operation of two counter-rotating vertical-axis wind turbines on a floating, semi-submersible platform is studied. The technology, called the Multiple Integrated and Synchronized Turbines (MIST) platform has the potential to reduce the cost of offshore wind energy per unit of installed capacity. Attached to the platform are closely-spaced, counter-rotating turbines, which can achieve a higher power density per planform area because of synergistic interaction effects. The purpose of the research is to control the orientation of the platform and rotational speeds of the turbines by modifying the energy absorbed by each of the generators of the turbines. To analyze the various aspects of the platform and wind turbines, the analysis is drawn from the fields of hydrodynamics, electromagnetics, aerodynamics and control theory. To study the hydrodynamics of the floating platform in incident monochromatic waves, potential theory is utilized, taking into account the slow-drift yaw motion of the platform. Steady, second-order moments that are spatially dependent (i.e., dependent on the platform's yaw orientation relative to the incident waves) are given special attention since there are no natural restoring yaw moment. The aerodynamics of the counter-rotating turbines are studied in collaboration with researchers at the UC Berkeley Mathematics Department using a high-order, implicit, large-eddy simulation. An element flipping technique is utilized to extend the method to a domain with counter-rotating turbines and the effects from the closely-spaced turbines is compared with existing experimental data. Hybrid testing techniques on a model platform are utilized to prove the controllability of the platform in lieu of a wind-wave tank. A 1:82 model-scale floating platform is fabricated and tested at the UC Berkeley Physical-Model Testing Facility. The vertical-axis wind turbines are simulated by spinning, controllable actuators that can be updated in real-time of

Subcycle interference upon tunnel ionization by counter-rotating two-color fields

Science.gov (United States)

Eckart, S.; Kunitski, M.; Ivanov, I.; Richter, M.; Fehre, K.; Hartung, A.; Rist, J.; Henrichs, K.; Trabert, D.; Schlott, N.; Schmidt, L. Ph. H.; Jahnke, T.; Schöffler, M. S.; Kheifets, A.; Dörner, R.

2018-04-01

We report on three-dimensional (3D) electron momentum distributions from single ionization of helium by a laser pulse consisting of two counter-rotating circularly polarized fields (390 and 780 nm). A pronounced 3D low-energy structure and subcycle interferences are observed experimentally and reproduced numerically using a trajectory-based semiclassical simulation. The orientation of the low-energy structure in the polarization plane is verified by numerical simulations solving the time-dependent Schrödinger equation.

Development of Streamwise Counter-Rotating Vortices in Flat Plate Boundary Layer Pre-set by Leading Edge Patterns

KAUST Repository

Hasheminejad, S.M.; Mitsudharmadi, Hatsari; Winoto, S.H.; Low, H.T.; Lua, K.B.

2017-01-01

Development of streamwise counter-rotating vortices induced by leading edge patterns with different pattern shape is investigated using hot-wire anemometry in the boundary layer of a flat plate. A triangular, sinusoidal and notched patterns

Design and Numerical Analysis of a Novel Counter-Rotating Self-Adaptable Wave Energy Converter Based on CFD Technology

Directory of Open Access Journals (Sweden)

Chongfei Sun

2018-03-01

Full Text Available The lack of an efficient and reliable power supply is currently one of the bottlenecks restricting the practical application of unmanned ocean detectors. Wave energy is the most widely distributed ocean energy, with the obvious advantages of high energy density and predictability. In this paper, a novel wave energy converter (WEC for power supply of low-power unmanned ocean detectors is proposed, which is a small-scale counter-rotating self-adaptive point absorber-type WEC. The double-layer counter-rotating absorbers can achieve the torque balance of the whole device. Besides, the self-adaptation of the blade to the water flow can maintain a unidirectional continuous rotation of the single-layer absorber. The WEC has several advantages, including small occupied space, simple exchange process and convenient modular integration. It is expected to meet the power demand of low-power ocean detectors. Through modeling and CFD analysis, it was found that the power and efficiency characteristics of WEC are greatly influenced by the relative flow velocity, the blade angle of the absorber and the interaction between the upper and lower absorbers. A physical prototype of the WEC was made and some related experiments were conducted to verify the feasibility of WEC working principle and the reliability of CFD analysis.

Confocal microscopy of colloidal dispersions in shear flow using a counter-rotating cone-plate shear cell

International Nuclear Information System (INIS)

Derks, Didi; Wisman, Hans; Blaaderen, Alfons van; Imhof, Arnout

2004-01-01

We report on novel possibilities for studying colloidal suspensions in a steady shear field in real space. Fluorescence confocal microscopy is combined with the use of a counter-rotating cone-plate shear cell. This allows imaging of individual particles in the bulk of a sheared suspension in a stationary plane. Moreover, this plane of zero velocity can be moved in the velocity gradient direction while keeping the shear rate constant. The colloidal system under study consists of rhodamine labelled PMMA spheres in a nearly density and refractive index matched mixture of cyclohexylbromide and cis-decalin. We show measured flow profiles in both the fluid and the crystalline phase and find indications for shear banding in the case of a sheared crystal. Furthermore, we show that, thanks to the counter-rotating principle of the cone-plate shear cell, a layer of particles in the bulk of a sheared crystalline suspension can be imaged for a prolonged time, with the result that their positions can be tracked

Finite-thickness effect on speed of a counter-rotating vortex pair at high Reynolds numbers

Science.gov (United States)

Habibah, Ummu; Nakagawa, Hironori; Fukumoto, Yasuhide

2018-03-01

We establish a general formula for the translational speed of a counter-rotating vortex pair, valid for thick cores, moving in an incompressible fluid with and without viscosity. We extend to higher order the method of matched asymptotic expansions developed by Ting and Tung (1965 Phys. Fluids 8 1039–51). The solution of the Euler or the Navier–Stokes equations is constructed in the form of a power series in a small parameter, the ratio of the core radius to the distance between the core centers. For a viscous vortex pair, the small parameter should be \\sqrt{ν /{{Γ }}} where ν is the kinematic viscosity of the fluid and Γ is the circulation of each vortex. A correction due to the effect of finite thickness of the vortices to the traveling speed makes its appearance at fifth order. A drastic simplification is achieved of expressing it solely in terms of the strength of the second-order quadrupole field associated with the elliptical deformation of the core. For a viscous vortex pair, we exploit the conservation law for the hydrodynamic impulse to derive the growth of the distance between the vortices, which is cubic in time.

Tip Vortex and Wake Characteristics of a Counterrotating Open Rotor

Science.gov (United States)

VanZante, Dale E.; Wernet, Mark P.

2012-01-01

One of the primary noise sources for Open Rotor systems is the interaction of the forward rotor tip vortex and blade wake with the aft rotor. NASA has collaborated with General Electric on the testing of a new generation of low noise, counterrotating Open Rotor systems. Three-dimensional particle image velocimetry measurements were acquired in the intra-rotor gap of the Historical Baseline blade set. The velocity measurements are of sufficient resolution to characterize the tip vortex size and trajectory as well as the rotor wake decay and turbulence character. The tip clearance vortex trajectory is compared to results from previously developed models. Forward rotor wake velocity profiles are shown. Results are presented in a form as to assist numerical modeling of Open Rotor system aerodynamics and acoustics.

A counter-rotating vortex pair in inviscid fluid

Science.gov (United States)

Habibah, Ummu; Fukumoto, Yasuhide

2017-12-01

We study the motion of a counter-rotating vortex pair with the circulations ±Γ move in incompressible fluid. The assumption is made that the core is very thin, that is the core radius σ is much smaller than the vortex radius d such that ɛ = σ/d ≪ 1. With this condition, the method of matched asymptotic expansion is employed. The solutions of the Navier-Stokes equations and the Biot-Savart law, regarding the inner and outer solutions respectively, are constructed in the form of a small parameter. An asymptotic expansion of the Biot-Savart law near the vortex core provides with the matching condition for an asymptotic expansion for limiting the Navier-Stokes equations for large radius r. The general formula of an anti-parallel vortex pair is established. At leading order O(ɛ0), we apply the special case in inviscid fluid, the Rankine vortex, a circular vortex of uniform vorticity. Furthermore at leading order O(ɛ5) we show the traveling speed of a vortex pair.

Contributions of the wall boundary layer to the formation of the counter-rotating vortex pair in transverse jets

KAUST Repository

SCHLEGEL, FABRICE

2011-04-08

Using high-resolution 3-D vortex simulations, this study seeks a mechanistic understanding of vorticity dynamics in transverse jets at a finite Reynolds number. A full no-slip boundary condition, rigorously formulated in terms of vorticity generation along the channel wall, captures unsteady interactions between the wall boundary layer and the jet - in particular, the separation of the wall boundary layer and its transport into the interior. For comparison, we also implement a reduced boundary condition that suppresses the separation of the wall boundary layer away from the jet nozzle. By contrasting results obtained with these two boundary conditions, we characterize near-field vortical structures formed as the wall boundary layer separates on the backside of the jet. Using various Eulerian and Lagrangian diagnostics, it is demonstrated that several near-wall vortical structures are formed as the wall boundary layer separates. The counter-rotating vortex pair, manifested by the presence of vortices aligned with the jet trajectory, is initiated closer to the jet exit. Moreover tornado-like wall-normal vortices originate from the separation of spanwise vorticity in the wall boundary layer at the side of the jet and from the entrainment of streamwise wall vortices in the recirculation zone on the lee side. These tornado-like vortices are absent in the case where separation is suppressed. Tornado-like vortices merge with counter-rotating vorticity originating in the jet shear layer, significantly increasing wall-normal circulation and causing deeper jet penetration into the crossflow stream. © 2011 Cambridge University Press.

Counterrotating-Shoulder Mechanism for Friction Stir Welding

Science.gov (United States)

Nunes, Arthur C., Jr.

2007-01-01

A counterrotating-shoulder mechanism has been proposed as an alternative to the mechanism and fixtures used in conventional friction stir welding. The mechanism would internally react most or all of the forces and torques exerted on the workpiece, making it unnecessary to react the forces and torques through massive external fixtures. In conventional friction stir welding, a rotating pin tool is inserted into, and moved along, a weld seam. As the pin tool moves, it stirs together material from the opposite sides of the seam to form the weld. A large axial plunge force must be exerted upon the workpiece through and by the pin tool and a shoulder attached above the pin tool in order to maintain the pressure necessary for the process. The workpiece is secured on top of an anvil, which supports the workpiece against the axial plunge force and against the torque exerted by the pin tool and shoulder. The anvil and associated fixtures must be made heavy (and, therefore, are expensive) to keep the workpiece stationary. In addition, workpiece geometries must be limited to those that can be accommodated by the fixtures. The predecessor of the proposed counterrotating-shoulder mechanism is a second-generation, self-reacting tool, resembling a bobbin, that makes it possible to dispense with the heavy anvil. This tool consists essentially of a rotating pin tool with opposing shoulders. Although the opposing shoulders maintain the necessary pressure without need to externally apply or react a large plunge force, the torque exerted on the workpiece remains unreacted in the absence of a substantial external fixture. Depending on the RPM and the thickness of the workpiece, the torque can be large. The proposed mechanism (see figure) would include a spindle attached to a pin tool with a lower shoulder. The spindle would be coupled via splines to the upper one of three bevel gears in a differential drive. The middle bevel gear would be the power-input gear and would be coupled to the

Design, experimental analysis, and unsteady Reynolds-averaged Navier-Stokes simulation of laboratory-scale counter-rotating vertical-axis turbines in marine environment

Science.gov (United States)

Doan, Minh; Padricelli, Claudrio; Obi, Shinnosuke; Totsuka, Yoshitaka

2017-11-01

We present the torque and power measurement of laboratory-scale counter-rotating vertical-axis hydrokinetic turbines, built around a magnetic hysteresis brake as the speed controller and a Hall-effect sensor as the rotational speed transducer. A couple of straight-three-bladed turbines were linked through a transmission of spur gears and timing pulleys and coupled to the electronic instrumentation via flexible shaft couplers. A total of 8 experiments in 2 configurations were conducted in the water channel facility (4-m long, 0.3-m wide, and 0.15-m deep). Power generation of the turbines (0.06-m rotor diameter) was measured and compared with that of single turbines of the same size. The wakes generated by these experiments were also measured by particle image velocimetry (PIV) and numerically simulated by unsteady Reynolds-averaged Navier-Stokes (URANS) simulation using OpenFOAM. Preliminary results from wake measurement indicated the mechanism of enhanced power production behind the counter-rotating configuration of vertical-axis turbines. Current address: Politecnico di Milano.

Performance Limiting Flow Processes in High-State Loading High-Mach Number Compressors

National Research Council Canada - National Science Library

Tan, Choon S

2008-01-01

In high-stage loading high-Mach number (HLM) compressors, counter-rotating pairs of discrete vortices are shed at the trailing edge of the upstream blade row at a frequency corresponding to the downstream rotor blade passing frequency...

Observing pure effects of counter-rotating terms without ultrastrong coupling: A single photon can simultaneously excite two qubits

Science.gov (United States)

Wang, Xin; Miranowicz, Adam; Li, Hong-Rong; Nori, Franco

2017-12-01

The coherent process that a single photon simultaneously excites two qubits has recently been theoretically predicted by Garziano et al. [L. Garziano, V. Macrì, R. Stassi, O. Di Stefano, F. Nori, and S. Savasta, One Photon Can Simultaneously Excite two or More Atoms, Phys. Rev. Lett. 117, 043601 (2016), 10.1103/PhysRevLett.117.043601]. We propose a different approach to observe a similar dynamical process based on a superconducting quantum circuit, where two coupled flux qubits longitudinally interact with the same resonator. We show that this simultaneous excitation of two qubits (assuming that the sum of their transition frequencies is close to the cavity frequency) is related to the counter-rotating terms in the dipole-dipole coupling between two qubits, and the standard rotating-wave approximation is not valid here. By numerically simulating the adiabatic Landau-Zener transition and Rabi-oscillation effects, we clearly verify that the energy of a single photon can excite two qubits via higher-order transitions induced by the longitudinal couplings and the counter-rotating terms. Compared with previous studies, the coherent dynamics in our system only involves one intermediate state and, thus, exhibits a much faster rate. We also find transition paths which can interfere. Finally, by discussing how to control the two longitudinal-coupling strengths, we find a method to observe both constructive and destructive interference phenomena in our system.

Design and aero-acoustic analysis of a counter-rotating wind turbine

Science.gov (United States)

Agrawal, Vineesh V.

Wind turbines have become an integral part of the energy business because they are one of the most economical and reliable sources of renewable energy. Conventional wind turbines are capable of capturing less than half of the energy present in the wind. Hence, to make the wind turbines more efficient, it is important to increase their performance. A horizontal axis wind turbine with multiple rotors is one concept that can achieve a higher power conversion rate. Also, a concern for wind energy is the noise generated by wind turbines. Hence, an investigation into the acoustic behavior of a multi-rotor horizontal axis wind turbine is required. In response to the need of a wind turbine design with higher power coefficient, a unique design of a counter-rotating horizontal axis wind turbine (CR-HAWT) is proposed. The Blade Element Momentum (BEM) theory is used to aerodynamically design the blades of the two rotors. Modifications are made to the BEM theory to accommodate the interaction of the two rotors. The tower effect on the noise generation of the downwind rotor is investigated. Predictions are made for the total noise generated by the wind turbine at its design operating conditions. A total power coefficient of 65.2% is predicted for the proposed CR-HAWT design. A low tip speed ratio is chosen to minimize the noise generation. The aeroacoustic analysis of the CR-HAWT shows that the noise generated at its design operating conditions is within an acceptable range. Thus, the CR-HAWT is predicted to be a quiet wind turbine with a high power coefficient, making it highly desirable for small wind turbine applications.

Numerical investigations of passive scalar transport in Taylor-Couette flows: Counter-rotation effect

Science.gov (United States)

Ouazib, Nabila; Salhi, Yacine; Si-Ahmed, El-Khider; Legrand, Jack; Degrez, G.

2017-07-01

Numerical methods for solving convection-diffusion-reaction (CDR) scalar transport equation in three-dimensional flow are used in the present investigation. The flow is confined between two concentric cylinders both the inner cylinder and the outer one are allowed to rotate. Direct numerical simulations (DNS) have been achieved to study the effects of the gravitational and the centrifugal potentials on the stability of incompressible Taylor-Couette flow. The Navier-Stokes equations and the uncoupled convection-diffusion-reaction equation are solved using a spectral development in one direction combined together with a finite element discretization in the two remaining directions. The complexity of the patterns is highlighted. Since, it increases as the rotation rates of the cylinders increase. In addition, the effect of the counter-rotation of the cylinders on the mass transfer is pointed out.

Investigation of the Unsteady Total Pressure Profile Corresponding to Counter-Rotating Vortices in an Internal Flow Application

Science.gov (United States)

Gordon, Kathryn; Morris, Scott; Jemcov, Aleksandar; Cameron, Joshua

2013-11-01

The interaction of components in a compressible, internal flow often results in unsteady interactions between the wakes and moving blades. A prime example in which this flow feature is of interest is the interaction between the downstream rotor blades in a transonic axial compressor with the wake vortices shed from the upstream inlet guide vane (IGV). Previous work shows that a double row of counter-rotating vortices convects downstream into the rotor passage as a result of the rotor blade bow shock impinging on the IGV. The rotor-relative time-mean total pressure distribution has a region of high total pressure corresponding to the pathline of the vortices. The present work focuses on the relationship between the magnitude of the time-mean rotor-relative total pressure profile and the axial spacing between the IGV and the rotor. A survey of different axial gap sizes is performed in a two-dimensional computational study to obtain the sensitivity of the pressure profile amplitude to IGV-rotor axial spacing.

High thermal conductivity connector having high electrical isolation

Science.gov (United States)

Nieman, Ralph C.; Gonczy, John D.; Nicol, Thomas H.

1995-01-01

A method and article for providing a low-thermal-resistance, high-electrical-isolation heat intercept connection. The connection method involves clamping, by thermal interference fit, an electrically isolating cylinder between an outer metallic ring and an inner metallic disk. The connection provides durable coupling of a heat sink and a heat source.

Development of Streamwise Counter-Rotating Vortices in Flat Plate Boundary Layer Pre-set by Leading Edge Patterns

KAUST Repository

Hasheminejad, S.M.

2017-04-03

Development of streamwise counter-rotating vortices induced by leading edge patterns with different pattern shape is investigated using hot-wire anemometry in the boundary layer of a flat plate. A triangular, sinusoidal and notched patterns with the same pattern wavelength λ of 15mm and the same pattern amplitude A of 7.5mm were examined for free-stream velocity of 3m/s. The results show a good agreement with earlier studies. The inflection point on the velocity profile downstream of the trough of the patterns at the beginning of the vortex formation indicates that the vortices non-linearly propagate downstream. An additional vortex structure was also observed between the troughs of the notched pattern.

High voltage isolation transformer

Science.gov (United States)

Clatterbuck, C. H.; Ruitberg, A. P. (Inventor)

1985-01-01

A high voltage isolation transformer is provided with primary and secondary coils separated by discrete electrostatic shields from the surfaces of insulating spools on which the coils are wound. The electrostatic shields are formed by coatings of a compound with a low electrical conductivity which completely encase the coils and adhere to the surfaces of the insulating spools adjacent to the coils. Coatings of the compound also line axial bores of the spools, thereby forming electrostatic shields separating the spools from legs of a ferromagnetic core extending through the bores. The transformer is able to isolate a high constant potential applied to one of its coils, without the occurrence of sparking or corona, by coupling the coatings, lining the axial bores to the ferromagnetic core and by coupling one terminal of each coil to the respective coating encasing the coil.

High-Voltage Isolation Transformer

Science.gov (United States)

Clatterbuck, C. H.; Ruitberg, A. P.

1985-01-01

Arcing and field-included surface erosion reduced by electrostatic shields around windings and ferromagnetic core of 80-kilovolt isolation transformer. Fabricated from high-resistivity polyurethane-based material brushed on critical surfaces, shields maintained at approximately half potential difference of windings.

Engineering & Performance of DuoTurbo: Microturbine with Counter-Rotating Runners

Science.gov (United States)

Biner, D.; Hasmatuchi, V.; Violante, D.; Richard, S.; Chevailler, S.; Andolfatto, L.; Avellan, F.; Münch, C.

2016-11-01

Considering the nuclear phase-out strategy of several European countries and the future tendency to promote renewable energies, the exploitation of small hydropower sites (industrial partners. The modular in-line “plug & play” technology requires low investment, reaching economic feasibility with an available power between 5 kW and 25 kW. One stage of the microturbine consists of two axial counter-rotating runners that form a compact independent unit. Each runner of the turbine holds its own rim generator, the DuoTurbo-configuration involving that each hydraulic runner is integral with each electrical rotor. The possibility of stacking several stages in series enables covering quite a wide range of hydraulic power and, thus, recovering a maximum of energy dissipated in release valves of water supply systems. The present work introduces the global concept of the implemented prototype of the DuoTurbo-microturbine, to target a maximal injected power of 5 kW for a discharge of 9 l/s and a head of 24.5 m per stage. The main features of the hydraulic, the mechanical, the electrical and the electronic design are presented. The hydraulic performance is, then, assessed using CFD simulations for the expected operating range. Finally, the performance measurements of the single-stage prototype installed in the hydraulic test rig of the HES-SO Valais//Wallis are presented.

Design analysis of a self-acting spiral-groove ring seal for counter-rotating shafts

Science.gov (United States)

Dirusso, E.

1983-01-01

A self-acting spiral groove inter-shaft ring seal of nominal 16.33 cm (6.43 in.) diameter for sealing fan bleed air between counter-rotating hafts in advanced turbofan engines was analyzed. The analysis focused on the lift force characteristics of the spiral grooves. A NASA Lewis developed computer program for predicting the performance of gas lubricated face seals was used to optimize the spiral groove geometry to produce maximum lift force. Load capacity curves (lift force as function of film thickness) were generated for four advanced turbofan engine operating conditions at relative seal speeds ranging from 17,850 to 29,800 rpm, sealed air pressures from 6 to 42 N/sq cm (9 to 60 psi) absolute and temperatures from 95 deg to 327 C (203 deg to 620 F). The relative seal sliding speed range was 152 to 255 m/sec (500 to 836 ft/sec). The analysis showed that the spiral grooves are capable of producing sufficient lift force such that the ring seal will operate in a noncontacting mode over the operating range of typical advanced turbofan engines.

Numerical Investigation on the Influence of Hot Streak Temperature Ratio in a High-Pressure Stage of Vaneless Counter-Rotating Turbine

Directory of Open Access Journals (Sweden)

Zhao Qingjun

2007-01-01

Full Text Available The results of recent studies have shown that combustor exit temperature distortion can cause excessive heat load of high-pressure turbine (HPT rotor blades. The heating of HPT rotor blades can lead to thermal fatigue and degrade turbine performance. In order to explore the influence of hot streak temperature ratio on the temperature distributions of HPT airfoil surface, three-dimensional multiblade row unsteady Navier-Stokes simulations have been performed in a vaneless counter-rotating turbine (VCRT. The hot streak temperature ratios from 1.0 (without hot streak to 2.4 were used in these numerical simulations, including 1.0, 1.2, 1.6, 2.0, and 2.4 temperature ratios. The hot streak is circular in shape with a diameter equal to 25% of the span. The center of the hot streak is located at 50% of span and 0% of pitch (the leading edge of the HPT stator vane. The predicted results show that the hot streak is relatively unaffected as it migrates through the HPT stator. The hot streak mixes with the vane wake and convects towards the pressure surface (PS of the HPT rotor when it moves over the vane surface of the HPT stator. The heat load of the HPT rotor increases with the increase of the hot streak temperature ratio. The existence of the inlet temperature distortion induces a thin layer of cooler air in the HPT rotor, which separates the PS of the HPT rotor from the hotter fluid. The numerical results also indicating the migration characteristics of the hot streak in the HPT rotor are predominated by the combined effects of secondary flow and buoyancy. The combined effects that induce the high-temperature fluid migrate towards the hub on the HPT rotor. The effect of the secondary flow on the hotter fluid increases as the hot streak temperature ratio is increased. The influence of buoyancy is directly proportional to the hot streak temperature ratio. The predicted results show that the increase of the hot streak temperature ratio trends to increase

Deflection and trapping of a counter-rotating vortex pair by a flat plate

Science.gov (United States)

Nitsche, Monika

2017-12-01

The interaction of a counter-rotating vortex pair (dipole) with a flat plate in its path is studied numerically. The vortices are initially separated by a distance D (dipole size) and placed far upstream of a plate of length L . The plate is centered on the dipole path and inclined relative to it at an incident angle βi. At first, the plate is held fixed in place. The vortices approach the plate, travel around it, and then leave as a dipole with unchanged velocity but generally a different travel direction, measured by a transmitted angle βt. For certain plate angles the transmitted angle is highly sensitive to changes in the incident angle. The sensitivity increases as the dipole size decreases relative to the plate length. In fact, for sufficiently small values of D /L , singularities appear: near critical values of βi, the dipole trajectory undergoes a topological discontinuity under changes of βi or D /L . The discontinuity is characterized by a jump in the winding number of one vortex around the plate, and in the time that the vortices take to leave the plate. The jumps occur repeatedly in a self-similar, fractal fashion, within a region near the critical values of βi, showing the existence of incident angles that trap the vortices, which never leave the plate. The number of these trapping regions increases as the parameter D /L decreases, and the dependence of the motion on βi becomes increasingly complex. The simulations thus show that even in this apparently simple scenario, the inviscid dynamics of a two-point-vortex system interacting with a stationary wall is surprisingly rich. The results are then applied to separate an incoming stream of dipoles by an oscillating plate.

Streamwise counter-rotating vortices generated by triangular leading edge pattern in flat plate boundary layer

KAUST Repository

Hasheminejad, S. M.

2016-01-05

A series of flow visualizations were conducted to qualitatively study the development of streamwise counter-rotating vortices over a flat plate induced by triangular patterns at the leading edge of a flat plate. The experiments were carried out for a Reynolds number based on the pattern wavelength (λ) of 3080. The results depict the onset, development and breakdown of the vortical structures within the flat plate boundary layer. Moreover, the effect of one spanwise array of holes with diameter of 0.2λ (=3 mm) was examined. This investigation was done on two different flat plates with holes placed at the location x/λ = 2 downstream of the troughs and peaks. The presence of holes after troughs does not show any significant effect on the vortical structures. However, the plate with holes after peaks noticeably delays the vortex breakdown. In this case, the “mushroom-like” vortices move away from the wall and propagate downstream with stable vortical structures. The vortex growth is halted further downstream but start to tilt aside.

High Current Planar Transformer for Very High Efficiency Isolated Boost DC-DC Converters

DEFF Research Database (Denmark)

Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

2014-01-01

This paper presents a design and optimization of a high current planar transformer for very high efficiency dc-dc isolated boost converters. The analysis considers different winding arrangements, including very high copper thickness windings. The analysis is focused on the winding ac-resistance a......This paper presents a design and optimization of a high current planar transformer for very high efficiency dc-dc isolated boost converters. The analysis considers different winding arrangements, including very high copper thickness windings. The analysis is focused on the winding ac......-resistance and transformer leakage inductance. Design and optimization procedures are validated based on an experimental prototype of a 6 kW dcdc isolated full bridge boost converter developed on fully planar magnetics. The prototype is rated at 30-80 V 0-80 A on the low voltage side and 700-800 V on the high voltage side...... with a peak efficiency of 97.8% at 80 V 3.5 kW. Results highlights that thick copper windings can provide good performance at low switching frequencies due to the high transformer filling factor. PCB windings can also provide very high efficiency if stacked in parallel utilizing the transformer winding window...

Highly Dense Isolated Metal Atom Catalytic Sites

DEFF Research Database (Denmark)

Chen, Yaxin; Kasama, Takeshi; Huang, Zhiwei

2015-01-01

-ray diffraction. A combination of electron microscopy images with X-ray absorption spectra demonstrated that the silver atoms were anchored on five-fold oxygen-terminated cavities on the surface of the support to form highly dense isolated metal active sites, leading to excellent reactivity in catalytic oxidation......Atomically dispersed noble-metal catalysts with highly dense active sites are promising materials with which to maximise metal efficiency and to enhance catalytic performance; however, their fabrication remains challenging because metal atoms are prone to sintering, especially at a high metal...... loading. A dynamic process of formation of isolated metal atom catalytic sites on the surface of the support, which was achieved starting from silver nanoparticles by using a thermal surface-mediated diffusion method, was observed directly by using in situ electron microscopy and in situ synchrotron X...

Compact, Lightweight, High Voltage Propellant Isolators, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — TA&T, Inc. proposes an enabling fabrication process for high voltage isolators required in high power solar electric and nuclear electric propulsion (SEP and...

Multiobjective Optimization of a Counterrotating Type Pump-Turbine Unit Operated at Turbine Mode

Directory of Open Access Journals (Sweden)

Jin-Hyuk Kim

2014-05-01

Full Text Available A multiobjective optimization for improving the turbine output and efficiency of a counterrotating type pump-turbine unit operated at turbine mode was carried out in this work. The blade geometry of both the runners was optimized using a hybrid multiobjective evolutionary algorithm coupled with a surrogate model. Three-dimensional Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model were discretized by finite volume approximations and solved on hexahedral grids to analyze the flow in the pump-turbine unit. As major hydrodynamic performance parameters, the turbine output and efficiency were selected as objective functions with two design variables related to the hub profiles of both the runner blades. These objectives were numerically assessed at twelve design points selected by Latin hypercube sampling in the design space. Response surface approximation models for the objectives were constructed based on the objective function values at the design points. A fast nondominated sorting genetic algorithm for the local search coupled with the response surface approximation models was applied to determine the global Pareto-optimal solutions. The trade-off between the two objectives was determined and described with respect to the Pareto-optimal solutions. The results of this work showed that the turbine outputs and efficiencies of optimized pump-turbine units were simultaneously improved in comparison to the reference unit.

Vacuum Bloch-Siegert shift in Landau polaritons with ultra-high cooperativity

Science.gov (United States)

Li, Xinwei; Bamba, Motoaki; Zhang, Qi; Fallahi, Saeed; Gardner, Geoff C.; Gao, Weilu; Lou, Minhan; Yoshioka, Katsumasa; Manfra, Michael J.; Kono, Junichiro

2018-06-01

A two-level system resonantly interacting with an a.c. magnetic or electric field constitutes the physical basis of diverse phenomena and technologies. However, Schrödinger's equation for this seemingly simple system can be solved exactly only under the rotating-wave approximation, which neglects the counter-rotating field component. When the a.c. field is sufficiently strong, this approximation fails, leading to a resonance-frequency shift known as the Bloch-Siegert shift. Here, we report the vacuum Bloch-Siegert shift, which is induced by the ultra-strong coupling of matter with the counter-rotating component of the vacuum fluctuation field in a cavity. Specifically, an ultra-high-mobility two-dimensional electron gas inside a high-Q terahertz cavity in a quantizing magnetic field revealed ultra-narrow Landau polaritons, which exhibited a vacuum Bloch-Siegert shift up to 40 GHz. This shift, clearly distinguishable from the photon-field self-interaction effect, represents a unique manifestation of a strong-field phenomenon without a strong field.

Counter-rotating type axial flow pump unit in turbine mode for micro grid system

International Nuclear Information System (INIS)

Kasahara, R; Takano, G; Komaki, K; Murakami, T; Kanemoto, T

2012-01-01

Traditional type pumped storage system contributes to adjust the electric power unbalance between day and night, in general. This serial research proposes the hybrid power system combined the wind power unit with the pump-turbine unit, to provide the constant output for the grid system, even at the suddenly fluctuating/turbulent wind. In the pumping mode, the pump should operate unsteadily at not only the normal but also the partial discharge. The operation may be unstable in the rising portion of the head characteristics at the lower discharge, and/or bring the cavitation at the low suction head. To simultaneously overcome both weak points, the authors have proposed a superior pump unit that is composed of counter-rotating type impellers and a peculiar motor with double rotational armatures. This paper discusses the operation at the turbine mode of the above unit. It is concluded with the numerical simulations that this type unit can be also operated acceptably at the turbine mode, because the unit works so as to coincide the angular momentum change through the front runners/impellers with that thorough the rear runners/impellers, namely to take the axial flow at not only the inlet but also the outlet without the guide vanes.

Counter-rotating effects and entanglement dynamics in strongly coupled quantum-emitter-metallic-nanoparticle structures

Science.gov (United States)

Iliopoulos, Nikos; Thanopulos, Ioannis; Yannopapas, Vassilios; Paspalakis, Emmanuel

2018-03-01

We study the spontaneous emission of a two-level quantum emitter next to a plasmonic nanoparticle beyond the Markovian approximation and the rotating-wave approximation (RWA) by combining quantum dynamics and classical electromagnetic calculations. For emitters with decay times in the picosecond to nanosecond time regime, as well as located at distances from the nanoparticle up to its radius, the dynamics with and without the RWA and the transition from the non-Markovian to the Markovian regime are investigated. For emitters with longer decay times, the Markov approximation proves to be adequate for distances larger than half the nanoparticle radius. However, the RWA is correct for all distances of the emitter from the nanoparticle. For short decay time emitters, the Markov approximation and RWA are both inadequate, with only the RWA becoming valid again at a distance larger than half the nanoparticle radius. We also show that the entanglement dynamics of two initially entangled qubits interacting independently with the nanoparticle may have a strong non-Markovian character when counter-rotating effects are included. Interesting effects such as entanglement sudden death, periodic entanglement revival, entanglement oscillations, and entanglement trapping are further observed when different initial two-qubit states and different distances between the qubit and the nanoparticle are considered.

THE GRAFTING OF MALEIC-ANHYDRIDE ON HIGH-DENSITY POLYETHYLENE IN AN EXTRUDER

NARCIS (Netherlands)

GANZEVELD, KJ; JANSSEN, LPBM

The grafting of maleic anhydride (MAH) on high density polyethylene in a counter-rotating twin screw extruder has been studied. As the reaction kinetics appear to be affected by mass transfer, good micro mixing in the extruder is important. Due to the competing mechanisms of increasing mixing and

Direct numerical simulation of a compressible boundary-layer flow past an isolated three-dimensional hump in a high-speed subsonic regime

Science.gov (United States)

De Grazia, D.; Moxey, D.; Sherwin, S. J.; Kravtsova, M. A.; Ruban, A. I.

2018-02-01

In this paper we study the boundary-layer separation produced in a high-speed subsonic boundary layer by a small wall roughness. Specifically, we present a direct numerical simulation (DNS) of a two-dimensional boundary-layer flow over a flat plate encountering a three-dimensional Gaussian-shaped hump. This work was motivated by the lack of DNS data of boundary-layer flows past roughness elements in a similar regime which is typical of civil aviation. The Mach and Reynolds numbers are chosen to be relevant for aeronautical applications when considering small imperfections at the leading edge of wings. We analyze different heights of the hump: The smaller heights result in a weakly nonlinear regime, while the larger result in a fully nonlinear regime with an increasing laminar separation bubble arising downstream of the roughness element and the formation of a pair of streamwise counterrotating vortices which appear to support themselves.

High Isolation Dual-Polarized Patch Antenna with Hybrid Ring Feeding

Directory of Open Access Journals (Sweden)

Xian-Jing Lin

2017-01-01

Full Text Available This paper presents a hybrid ring feeding dual-polarized patch antenna with high isolation in a wide working band. The proposed antenna consists of a circular radiating patch printed on the upper horizontal substrate, two pairs of Γ shaped strips printed on two vertical substrates, and a hybrid ring feeding network printed on the lower two horizontal substrates. The proposed antenna adopts Γ shape strips coupled feeding structure to achieve a wide operating band. Furthermore, a hybrid ring feeding structure with high isolation in a wide bandwidth, which is firstly proposed, is applied as feeding network. When one port is excited, the feeding network can realize twice the power cancellation. Thus, high ports isolation characteristics can be obtained. A prototype of the proposed antenna is fabricated and measured. Measured results show that the 10 dB reflection coefficient bandwidths of the two ports are both about 38.7%, with port isolation higher than 40 dB through most of the band, and the cross-polarizations are below −24 dB.

Biosecurity measures in 48 isolation facilities managing highly infectious diseases.

Science.gov (United States)

Puro, Vincenzo; Fusco, Francesco M; Schilling, Stefan; Thomson, Gail; De Iaco, Giuseppina; Brouqui, Philippe; Maltezou, Helena C; Bannister, Barbara; Gottschalk, René; Brodt, Hans-Rheinhard; Ippolito, Giuseppe

2012-06-01

Biosecurity measures are traditionally applied to laboratories, but they may also be usefully applied in highly specialized clinical settings, such as the isolation facilities for the management of patients with highly infectious diseases (eg, viral hemorrhagic fevers, SARS, smallpox, potentially severe pandemic flu, and MDR- and XDR-tuberculosis). In 2009 the European Network for Highly Infectious Diseases conducted a survey in 48 isolation facilities in 16 European countries to determine biosecurity measures for access control to the facility. Security personnel are present in 39 facilities (81%). In 35 facilities (73%), entrance to the isolation area is restricted; control methods include electronic keys, a PIN system, closed-circuit TV, and guards at the doors. In 25 facilities (52%), identification and registration of all staff entering and exiting the isolation area are required. Access control is used in most surveyed centers, but specific lacks exist in some facilities. Further data are needed to assess other biosecurity aspects, such as the security measures during the transportation of potentially contaminated materials and measures to address the risk of an "insider attack."

Method for strontium isolation from high-mineralized water

International Nuclear Information System (INIS)

Evzhanov, Kh.; Andriyasova, G.M.

1983-01-01

A method to isolate strontium from high-mineralized waters containing sodium, magnesium, calcium and strontium chlorides, which differ from the prototype method in a considerable decrease in energy consumption with the preservation of a high degree of Sr, Mg and Ca isolation selectivity, has been suggested. According to the method suggested mineralized waters are treated with alkali (NaOH) in the amount of 95-97% of stoichiometry by magnesium, then after separation of magnesium hydroxide precipitate mother liquor is treated with sodium carbonate in the amount of 50-60% of stoichiometry by calcium. After separation of calcium carbonate precipitate mother liquor is treated with NaOH in the amount of 130-135% of stoichiometry by calcium. After separation of calcium hydroxide precipitate from mother liquor by means of sodium carbonate introduction strontium carbonate is isolated. The degree of strontium extraction in the form of SrCO 3 constitutes 90.5% of its content in the initial solution. The method presented can be used for strontium separation from natural and waste waters

The interaction of counter-rotating strained vortex pairs with a third vortex

International Nuclear Information System (INIS)

Higgins, Keith; Ooi, Andrew; Chong, M S; Ruetten, Markus

2009-01-01

The vortex dynamics caused by the interaction of counter-rotating Burgers vortex pairs with a third Burgers vortex in a straining flow is investigated numerically. These interactions blend vortex merging and cancellation effects, and the aim is to investigate how the third vortex might influence the evolution of the vortex pair. Many different choices of initial conditions for the pair and third vortex exist, so attention is restricted to a class of initial conditions in which the vortex pair initially moves in the general direction of vortex 3, and the distance from vortex 3 to the line of free propagation of the vortex pair is the 'offset' parameter δ. A series of calculations with 0≤δ≤4 reveals three types of intermediate-time vortex dynamics that are called merging, swapping and switching. The evolution of the vortex core separation and core vorticity level diagnostics are used to determine the points of transition from merging to swapping and switching. In the longer term, vortex merging, cancellation and straining reduces the three vortices to a single vortex. Other diagnostics of interest are also monitored, including the spatial distributions of the rate of viscous dissipation and terms contributing to the vorticity transport equation. During the merging phase for the case with δ=0, double-peak and double-trough structures are observed in the dissipation-rate contours. In addition, the diffusion of vorticity dominates the vortex-stretching effect near vortex 1 during its absorbtion by vortex 3. Finally, the dynamics of the three vortices are also examined by computing a co-rotating angular velocity and stream function. A series of peaks in the co-rotating angular velocity is found to be associated with the conservation of angular momentum and interactions with a 'ghost' vortex in the co-rotating stream function.

Very High Frequency Galvanic Isolated Offline Power Supply

DEFF Research Database (Denmark)

Pedersen, Jeppe Arnsdorf

During the last decades many researchers have turned their attention to raising the operation frequency of power converters to the very high frequency (VHF) range going from 30 MHz to 300 MHz. Increasing the operating frequency of a power converter leads to smaller energy storing components...... inverters with a single combined rectifier. The converter designed to deliver 9 W to a 60 V LED load and is achieving an efficiency of 89.4% and a power density of 2.14 W3 . The development of this converter proof that offline VHF converter can be implemented with high efficiencies even for low power applications...... are described together with the possibility of using capacitors as the power galvanic isolation, both methods of creating galvanic isolation are implemented in converters. Regarding EMC a series of converters with different filter implementations are examined. The results from the conducted mea-surement from 150...

High Rate of Resistance to Quinupristin-Dalfopristin in Enterococcus faecium Clinical Isolates from Korea

Science.gov (United States)

Oh, Won Sup; Ko, Kwan Soo; Song, Jae-Hoon; Lee, Mi Young; Park, Sulhee; Peck, Kyong Ran; Lee, Nam Yong; Kim, Choon-Kwan; Lee, Hyuck; Kim, Shin-Woo; Chang, Hyun-Ha; Kim, Yeon-Sook; Jung, Sook-In; Son, Jun Seong; Yeom, Joon-Sup; Ki, Hyun Kyun; Woo, Gun-Jo

2005-01-01

We tested the in vitro susceptibilities of 603 enterococcal isolates from eight tertiary-care hospitals in Korea. The quinupristin-dalfopristin resistance rate in Enterococcus faecium was very high (25 isolates, 10.0%). It was suggested that both clonal spread and the sporadic emergence of quinupristin-dalfopristin-resistant isolates may explain the high prevalence of quinupristin-dalfopristin resistance in Korea. PMID:16304198

Counter-rotating type tidal stream power unit boarded on pillar (performances and flow conditions of tandem propellers)

Science.gov (United States)

Usui, Yuta; Kanemoto, Toshiaki; Hiraki, Koju

2013-12-01

The authors have invented the unique counter-rotating type tidal stream power unit composed of the tandem propellers and the double rotational armature type peculiar generator without the traditional stator. The front and the rear propellers counter-drive the inner and the outer armatures of the peculiar generator, respectively. The unit has the fruitful advantages that not only the output is sufficiently higher without supplementary equipment such as a gearbox, but also the rotational moment hardly act on the pillar because the rotational torque of both propellers/armatures are counter-balanced in the unit. This paper discusses experimentally the performances of the power unit and the effects of the propeller rotation on the sea surface. The axial force acting on the pillar increases naturally with the increase of not only the stream velocity but also the drag of the tandem propellers. Besides, the force vertical to the stream also acts on the pillar, which is induced from the Karman vortex street and the dominant frequencies appear owing to the front and the rear propeller rotations. The propeller rotating in close to the sea surface brings the abnormal wave and the amplitude increases as the stream velocity is faster and/or the drag is stronger.

Sheppard-Taylor Isolated High Boost DC-DC Converter

DEFF Research Database (Denmark)

Chub, Andrii; Siwakoti, Yam Prasad; Vinnikov, Dmitri

2017-01-01

This paper presents a new galvanically isolated step-up dc-dc converter intended for low-power but high step-up applications. The proposed converter is capable of regulating output voltage within a wide range of the input voltage or load variations. In contrast to competitors, the converter can...

Title: High-level cefotaxime-resistant Proteus mirabilis strain isolated ...

African Journals Online (AJOL)

oaca

High-level cefotaxime-resistant Proteus mirabilis strain isolated from a Tunisian .... UV- visible) at 37°C. Specific activity is calculated on depending of. Ross and ..... Performance standards for antimicrobial susceptibility testing;. Seventeenth ...

A high voltage gain quasi Z-source isolated DC/DC converter

DEFF Research Database (Denmark)

Siwakoti, Yam P.; Blaabjerg, Frede; Loh, Poh Chiang

2014-01-01

A compact quasi-Z-source DC/DC converter is presented with high voltage gain, isolated output, and improved efficiency. The improvements in size and performance were achieved by using a square wave inverter with only two output switches driving an isolating transformer in push-pull mode, followed...... by a voltage doubling output rectifier. The converter is well-suited to applications requiring a high voltage gain, especially renewable energy sources such as photovoltaic and fuel-cell power supplies. To demonstrate the converter's performance a prototype designed to output 400 V at 500 W was constructed...

Self-oscillating Galvanic Isolated Bidirectional Very High Frequency DC-DC Converter

DEFF Research Database (Denmark)

Pedersen, Jeppe Arnsdorf; Madsen, Mickey Pierre; Knott, Arnold

2015-01-01

This paper describes a galvanic isolated bidirectional Very High Frequency (VHF = 30 MHz - 300MHz) ClassE converter. The reason for increasing the switching frequency is to minimize the passive components in the converter. To make the converter topology bidirectional the rectifier has to be synch......This paper describes a galvanic isolated bidirectional Very High Frequency (VHF = 30 MHz - 300MHz) ClassE converter. The reason for increasing the switching frequency is to minimize the passive components in the converter. To make the converter topology bidirectional the rectifier has...

Integrated hybrid vibration isolator with feedforward compensation for fast high-precision positioning X/Y tables

International Nuclear Information System (INIS)

Yan, T H; Li, Q; Xu, C; Pu, H Y; Chen, X D

2010-01-01

The design, realization and control technologies of a high-performance hybrid microvibration isolator for ultra-high-precision high-speed moving X/Y tables are presented in this paper—the novel isolator with integrated passive–active high level of damping. The passive damping was implemented using air-springs in both vertical and horizontal directions, with parallel linear motors in two directions to realize the active damping and the positioning functions. It is an actual hybrid isolation system because its air-spring can also be controlled through the pneumatic loop. The isolation servo system also has fast positioning capability via the feedforward compensation for the moving tables. Compared with the conventional filtered reference type control algorithms that rely on the assumption for the adaptive filter and the controlled system, in which the disturbance is estimated from the residual signal, the feedforward compensation here shows high effectiveness of vibration isolation and high-precision positioning performance for its platform. The performance of feedforward compensation has been enhanced via an efficient state estimation adaptive algorithm, the fast Kalman filter. Finally, experimental demonstration has been shown for the prototype system and the results have verified the effectiveness of the proposed isolator system design and the adaptive control algorithm for substantially enhanced damping of the platform system with the moving X/Y tables

High glucose impairs superoxide production from isolated blood neutrophils

DEFF Research Database (Denmark)

Perner, A; Nielsen, S E; Rask-Madsen, J

2003-01-01

Superoxide (O(2)(-)), a key antimicrobial agent in phagocytes, is produced by the activity of NADPH oxidase. High glucose concentrations may, however, impair the production of O(2)(-) through inhibition of glucose-6-phosphate dehydrogenase (G6PD), which catalyzes the formation of NADPH. This study...... measured the acute effects of high glucose or the G6PD inhibitor dehydroepiandrosterone (DHEA) on the production of O(2)(-) from isolated human neutrophils....

Isolation of high-quality total RNA from leaves of Myrciaria dubia "CAMU CAMU".

Science.gov (United States)

Gómez, Juan Carlos Castro; Reátegui, Alina Del Carmen Egoavil; Flores, Julián Torres; Saavedra, Roberson Ramírez; Ruiz, Marianela Cobos; Correa, Sixto Alfredo Imán

2013-01-01

Myrciaria dubia is a main source of vitamin C for people in the Amazon region. Molecular studies of M. dubia require high-quality total RNA from different tissues. So far, no protocols have been reported for total RNA isolation from leaves of this species. The objective of this research was to develop protocols for extracting high-quality total RNA from leaves of M. dubia. Total RNA was purified following two modified protocols developed for leaves of other species (by Zeng and Yang, and by Reid et al.) and one modified protocol developed for fruits of the studied species (by Silva). Quantity and quality of purified total RNA were assessed by spectrophotometric and electrophoretic analysis. Additionally, quality of total RNA was evaluated with reverse-transcription polymerase chain reaction (RT-PCR). With these three modified protocols we were able to isolate high-quality RNA (A260nm/A280nm >1.9 and A260nm/A230nm >2.0). Highest yield was produced with the Zeng and Yang modified protocol (384±46µg ARN/g fresh weight). Furthermore, electrophoretic analysis showed the integrity of isolated RNA and the absence of DNA. Another proof of the high quality of our purified RNA was the successful cDNA synthesis and amplification of a segment of the M. dubia actin 1 gene. We report three modified protocols for isolation total RNA from leaves of M. dubia. The modified protocols are easy, rapid, low in cost, and effective for high-quality and quantity total RNA isolation suitable for cDNA synthesis and polymerase chain reaction.

Active vibration isolation of high precision machines

CERN Document Server

Collette, C; Artoos, K; Hauviller, C

2010-01-01

This paper provides a review of active control strategies used to isolate high precisionmachines (e.g. telescopes, particle colliders, interferometers, lithography machines or atomic force microscopes) from external disturbances. The objective of this review is to provide tools to develop the best strategy for a given application. Firstly, the main strategies are presented and compared, using single degree of freedom models. Secondly, the case of huge structures constituted of a large number of elements, like particle colliders or segmented telescopes, is considered.

Isolation of high quality RNA from pistachio (Pistacia vera L.) and other woody plants high in secondary metabolites.

Science.gov (United States)

Moazzam Jazi, Maryam; Rajaei, Saideh; Seyedi, Seyed Mahdi

2015-10-01

The quality and quantity of RNA are critical for successful downstream transcriptome-based studies such as microarrays and RNA sequencing (RNA-Seq). RNA isolation from woody plants, such as Pistacia vera, with very high amounts of polyphenols and polysaccharides is an enormous challenge. Here, we describe a highly efficient protocol that overcomes the limitations posed by poor quality and low yield of isolated RNA from pistachio and various recalcitrant woody plants. The key factors that resulted in a yield of 150 μg of high quality RNA per 200 mg of plant tissue include the elimination of phenol from the extraction buffer, raising the concentration of β-mercaptoethanol, long time incubation at 65 °C, and nucleic acid precipitation with optimized volume of NaCl and isopropyl alcohol. Also, the A260/A280 and A260/A230 of extracted RNA were about 1.9-2.1and 2.2-2.3, respectively, revealing the high purity. Since the isolated RNA passed highly stringent quality control standards for sensitive reactions, including RNA sequencing and real-time PCR, it can be considered as a reliable and cost-effective method for RNA extraction from woody plants.

Rapid isolation of high molecular weight DNA from single dried ...

African Journals Online (AJOL)

ANAND

For studying genetic diversity in populations of predatory coccinellid, Cryptolaemus montrouzieri. Mulsant (Coccinellidae: Coleoptera), our attempts to isolate high quality DNA from individual adult beetle using several previously reported protocols and even modifications were quite unsuccessful as the insect size was small ...

Status of technology for isolating high-level radioactive wastes in geologic repositories

International Nuclear Information System (INIS)

Klingsberg, C.; Duguid, J.

1980-10-01

This report attempts to summarize the status of scientific and technological knowledge relevant to long-term isolation of high-level and transuranic wastes in a mined geologic repository. It also identifies and evaluates needed information and identifies topics in which work is under way or needed to reduce uncertainties. The major findings and conclusions on the following topics are presented: importance of the systems approach; prospects for successful isolation of wastes; need for site-specific investigations; human activities in the future; importance of modelling; disposal of transuranic wastes; status of technology of isolation barriers, performance assessment, site selection and characterization, and potential host rocks

CHARACTERIZATION OF A NEW BACILLUS-STEAROTHERMOPHILUS ISOLATE - A HIGHLY THERMOSTABLE ALPHA-AMYLASE-PRODUCING STRAIN

NARCIS (Netherlands)

WIND, RD; BUITELAAR, RM; EGGINK, G; HUIZING, HJ; DIJKHUIZEN, L

A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known alpha-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable alpha-amylase. The half-time of inactivation of this

Sustainability of High-Level Isolation Capabilities among US Ebola Treatment Centers.

Science.gov (United States)

Herstein, Jocelyn J; Biddinger, Paul D; Gibbs, Shawn G; Le, Aurora B; Jelden, Katelyn C; Hewlett, Angela L; Lowe, John J

2017-06-01

To identify barriers to maintaining and applying capabilities of US high-level isolation units (HLIUs) used during the Ebola virus disease outbreak, during 2016 we surveyed HLIUs. HLIUs identified sustainability challenges and reported the highly infectious diseases they would treat. HLIUs expended substantial resources in development but must strategize models of sustainability to maintain readiness.

Quality assurance during fabrication of high-damping rubber isolation bearings

Energy Technology Data Exchange (ETDEWEB)

Way, D.; Greaves, W.C. [Base Isolation Consultants, Inc., San Francisco, CA (United States)

1995-12-01

Successful implementation of a high-damping rubber (HDR) base isolation project requires the application of Quality Assurance/Quality Control (QA/QC) methodology through all phases of the bearing fabrication process. HDR base isolation bearings must be fabricated with uniform physical characteristics while being produced in large quantities. To satisfy this requirement, manufacturing processes must be controlled. Prototype tests that include dynamic testing of small samples of rubber are necessary. Stringent full scale bearing testing must be carried out prior to beginning production, during which manufacturing is strictly regulated by small rubber sample and production bearing testing. All such activities should be supervised and continuously inspected by independent and experienced QA/QC personnel.

Magnetically coupled high-gain Y-source isolated DC/DC converter

DEFF Research Database (Denmark)

Siwakoti, Yam P.; Loh, Poh Chiang; Blaabjerg, Frede

2014-01-01

A new form of magnetically coupled DC/DC converter is proposed for medium power applications (250 W to 2 kW), requiring a high-voltage gain, short inductive charging time and galvanic isolation. The proposed converter can be realised using a unique Y-source impedance network and a two-switch push...

Mapping of Geographically Isolated Wetlands of Western Siberia Using High Resolution Space Images

Science.gov (United States)

Dyukarev, E.; Pologova, N.; Dyukarev, A.; Lane, C.; Autrey, B. C.

2014-12-01

Using the remote sensing data for integrated study of natural objects is actual for investigation of difficult to access areas of West Siberia. The research of this study focuses on determining the extent and spectral signatures of isolated wetlands within Ob-Tom Interfluve area using Landsat and Quickbird space images. High-resolution space images were carefully examined and wetlands were manually delineated. Wetlands have clear visible signs at the high resolution space images. 567 wetlands were recognized as isolated wetlands with the area about 10 000 ha (of 2.5% of the study area). Isolated wetlands with area less 2 ha are the most frequent. Half of the total amount of wetlands has area less than 6.4 ha. The largest isolated wetland occupies 797 ha, and only 5% have area more than 50 ha. The Landsat 7 ETM+ data were used for analysis of vegetation structure and spectral characteristics of wetlands. The masked isolated wetlands image was classified into 12 land cover classes using ISODATA unsupervised classification. The attribution of unsupervised classification results allowed us to clearly recognize 7 types of wetlands: tall, low and sparse ryams (Pine-Shrub-Sphagnum community), open wetlands with shrub, moss or sedge cover, and open water objects. Analysis of spectral profiles for all classes has shown that Landsat spectral bands 4 and 5 have higher variability. These bands allow to separate wetland classed definitely. Accuracy assessment of isolated wetland map shows a good agreement with expert field data. The work was supported by grants ISTC № 4079.

Isolation of high quality graphene from Ru by solution phase intercalation

Science.gov (United States)

Koren, E.; Sutter, E.; Bliznakov, S.; Ivars-Barcelo, F.; Sutter, P.

2013-09-01

We introduce a method for isolating graphene grown on epitaxial Ru(0001)/α-Al2O3. The strong graphene/Ru(0001) coupling is weakened by electrochemically driven intercalation of hydrogen underpotentially deposited in aqueous KOH solution, which allows the penetration of water molecules at the graphene/Ru(0001) interface. Following these electrochemically driven processes, the graphene can be isolated by electrochemical hydrogen evolution and transferred to arbitrary supports. Raman and transport measurements demonstrate the high quality of the transferred graphene. Our results show that intercalation, typically carried out in vacuum, can be extended to solution environments for graphene processing under ambient conditions.

High Proportions of Multidrug-Resistant Acinetobacter spp. Isolates in a District in Western India: A Four-Year Antibiotic Susceptibility Study of Clinical Isolates

Directory of Open Access Journals (Sweden)

Ingvild Odsbu

2018-01-01

Full Text Available The purpose of the study was to determine the proportions of multidrug-resistant (MDR Acinetobacter spp. isolates from the district of Nashik in Western India during the period from 2011–2014. Antibacterial susceptibility testing of isolates from inpatients and outpatients was performed using Kirby–Bauer disc diffusion method to determine inhibitory zone diameters. Proportions of non-susceptible isolates were calculated from the antibacterial susceptibility data. MDR was defined as an isolate being non-susceptible to at least one antibacterial agent in at least three antibacterial categories. The change in proportions of MDR isolates; extended-spectrum β-lactamase (ESBL-producing isolates; and non-susceptible isolates to specific antibacterial categories over calendar time was investigated by logistic regression. The proportions of MDR and ESBL-producing isolates ranged from 89.4% to 95.9% and from 87.9% to 94.0%; respectively. The proportions of non-susceptible isolates to aminoglycosides; carbapenems; antipseudomonal penicillins/β-lactamase inhibitors; cephalosporins; folate pathway inhibitors; or penicillins/β-lactamase inhibitors exceeded 77.5%. Proportions of fluoroquinolone and tetracycline non-susceptible isolates ranged from 65.3% to 83.3% and from 71.3% to 75.9%; respectively. No changes in trends were observed over time; except for a decreasing trend in fluoroquinolone non-susceptible isolates (OR = 0.75 (95% CI, 0.62–0.91. Significantly higher proportions of non-susceptible; MDR and ESBL-producing isolates were found among isolates from the respiratory system compared to isolates from all other specimen types (p < 0.05. High proportions of MDR Acinetobacter spp. isolates were observed in the period from 2011–2014. Antimicrobial stewardship programmes are needed to prevent the emergence and spread of antibiotic resistance.

Highly leukemogenic radiation leukemia virus isolate is a thymotropic, immunosuppressive retrovirus with a unique RNA structure

Energy Technology Data Exchange (ETDEWEB)

Ben David, Y.; Kotler, M.; Yefenof, E.

1987-04-15

Clones of N-, B- and NB-fibrotropic viruses were isolated from weakly (D-RadLV) and strongly (A-RadLV) leukomogenic RadLV preparations. A highly leukemogenic, thymotropic virus (TV) was isolated by ex-vivo infection of thymocytes with A-RadLV. This virus could not be isolated from D-RadLV. Two-dimensional fingerprint analysis suggested that TV recombines unique RNA sequences with RNA genomic material derived from a B-tropic endogenous virus. C57BL/6 (B6) mice injected with B- or NB-fibrotropic clones, but not with TV or N-tropic viral clones, developed reactive T lymphocytes (Tr), capable of differentiating into anti-tumor cytotoxic cells. The N-tropic virus isolates were non-immunogenic in B6 mice whereas the TV isolate induced suppressor T lymphocytes (Ts) that abrogated a potential Tr response. These results suggest that emergence of highly leukemogenic RadLV involves activation of endogenous fibrotropic virus which is immunogenic in its natural host strain (B6). This virus can further recombine with other retroviral genetic sequences, resulting in a suppressogenic and thymotropic, highly leukemogenic virus.

Optimizing the Isolation of Microfibrillated Bamboo in High Pressure Enzymatic Hydrolysis

Directory of Open Access Journals (Sweden)

N. A. Sri Aprilia

2015-07-01

Full Text Available Bleached bamboo fiber was treated with a high pressure enzymatic hydrolysis (HPEH process in order to produce microfibrillated bamboo fiber (MBF. Mixture design of experiments was utilized to determine the optimal constituents of fiber, enzymes, and water for the HPEH process on the isolation yield of the MBF. Results showed the optimal combination for the maximal yield isolation of the MBF was 1 g fiber, 1 g enzyme, and 1 L water at 90 MPa and 70 °C. The influence of the reaction time of the HPEH process (6 to 48 h was also evaluated in this study. Morphological and thermal property analyses of untreated and treated bamboo fibers revealed that the HPEH process was effective for removing non-cellulosic components from the fibers. Thus, the HPEH process is an effective method for the isolation of the MBF, with the benefits of elevated crystallinity and thermal stability.

Three-Dimensional Vibration Isolator for Suppressing High-Frequency Responses for Sage III Contamination Monitoring Package (CMP)

Science.gov (United States)

Li, Y.; Cutright, S.; Dyke, R.; Templeton, J.; Gasbarre, J.; Novak, F.

2015-01-01

The Stratospheric Aerosol and Gas Experiment (SAGE) III - International Space Station (ISS) instrument will be used to study ozone, providing global, long-term measurements of key components of the Earth's atmosphere for the continued health of Earth and its inhabitants. SAGE III is launched into orbit in an inverted configuration on SpaceX;s Falcon 9 launch vehicle. As one of its four supporting elements, a Contamination Monitoring Package (CMP) mounted to the top panel of the Interface Adapter Module (IAM) box experiences high-frequency response due to structural coupling between the two structures during the SpaceX launch. These vibrations, which were initially observed in the IAM Engineering Development Unit (EDU) test and later verified through finite element analysis (FEA) for the SpaceX launch loads, may damage the internal electronic cards and the Thermoelectric Quartz Crystal Microbalance (TQCM) sensors mounted on the CMP. Three-dimensional (3D) vibration isolators were required to be inserted between the CMP and IAM interface in order to attenuate the high frequency vibrations without resulting in any major changes to the existing system. Wire rope isolators were proposed as the isolation system between the CMP and IAM due to the low impact to design. Most 3D isolation systems are designed for compression and roll, therefore little dynamic data was available for using wire rope isolators in an inverted or tension configuration. From the isolator FEA and test results, it is shown that by using the 3D wire rope isolators, the CMP high-frequency responses have been suppressed by several orders of magnitude over a wide excitation frequency range. Consequently, the TQCM sensor responses are well below their qualification environments. It is indicated that these high-frequency responses due to the typical instrument structural coupling can be significantly suppressed by a vibration passive control using the 3D vibration isolator. Thermal and contamination

Isolation and analysis of high quality nuclear DNA with reduced organellar DNA for plant genome sequencing and resequencing

Directory of Open Access Journals (Sweden)

Zdepski Anna

2011-05-01

Full Text Available Abstract Background High throughput sequencing (HTS technologies have revolutionized the field of genomics by drastically reducing the cost of sequencing, making it feasible for individual labs to sequence or resequence plant genomes. Obtaining high quality, high molecular weight DNA from plants poses significant challenges due to the high copy number of chloroplast and mitochondrial DNA, as well as high levels of phenolic compounds and polysaccharides. Multiple methods have been used to isolate DNA from plants; the CTAB method is commonly used to isolate total cellular DNA from plants that contain nuclear DNA, as well as chloroplast and mitochondrial DNA. Alternatively, DNA can be isolated from nuclei to minimize chloroplast and mitochondrial DNA contamination. Results We describe optimized protocols for isolation of nuclear DNA from eight different plant species encompassing both monocot and eudicot species. These protocols use nuclei isolation to minimize chloroplast and mitochondrial DNA contamination. We also developed a protocol to determine the number of chloroplast and mitochondrial DNA copies relative to the nuclear DNA using quantitative real time PCR (qPCR. We compared DNA isolated from nuclei to total cellular DNA isolated with the CTAB method. As expected, DNA isolated from nuclei consistently yielded nuclear DNA with fewer chloroplast and mitochondrial DNA copies, as compared to the total cellular DNA prepared with the CTAB method. This protocol will allow for analysis of the quality and quantity of nuclear DNA before starting a plant whole genome sequencing or resequencing experiment. Conclusions Extracting high quality, high molecular weight nuclear DNA in plants has the potential to be a bottleneck in the era of whole genome sequencing and resequencing. The methods that are described here provide a framework for researchers to extract and quantify nuclear DNA in multiple types of plants.

Genotyping of Listeria monocytogenes isolates from poultry carcasses using high resolution melting (HRM) analysis.

Science.gov (United States)

Sakaridis, Ioannis; Ganopoulos, Ioannis; Madesis, Panagiotis; Tsaftaris, Athanasios; Argiriou, Anagnostis

2014-01-02

An outbreak situation of human listeriosis requires a fast and accurate protocol for typing Listeria monocytogenes . Existing techniques are either characterized by low discriminatory power or are laborious and require several days to give a final result. Polymerase chain reaction (PCR) coupled with high resolution melting (HRM) analysis was investigated in this study as an alternative tool for a rapid and precise genotyping of L. monocytogenes isolates. Fifty-five isolates of L. monocytogenes isolated from poultry carcasses and the environment of four slaughterhouses were typed by HRM analysis using two specific markers, internalin B and ssrA genes. The analysis of genotype confidence percentage of L. monocytogenes isolates produced by HRM analysis generated dendrograms with two major groups and several subgroups. Furthermore, the analysis of the HRM curves revealed that all L. monocytogenes isolates could easily be distinguished. In conclusion, HRM was proven to be a fast and powerful tool for genotyping isolates of L. monocytogenes .

Identification of factors that influence the stiffness of high-damping elastomer seismic isolation bearings

International Nuclear Information System (INIS)

Kulak, R.F.; Hughes, T.H.

1994-01-01

During the past decade, high-damping elastomer, steel-laminated seismic isolation bearings have gained acceptance as a device for isolating large buildings and structures from earthquake damage. In the United States, architectural engineering firms custom design isolators for each project and ten have the isolators manufactured by one of less than a hand-full of manufactures. The stiffness of the bearing is the single most important design parameter that the molded bearing must meet because it determines the fundamental frequency of the isolation system. This paper reports on recent research that examined several factors that cause real and potential variations to the stiffness of the bearing. The resulting changes to the fundamental frequency of the isolated structure are quantified for each factor. The following were examined: (1) dimensional tolerances, (2) frequency effects, (3) temperature effects, (4) cyclical effects, and (5) aging effects. It was found that geometric variations barely affect the stiffness whereas temperature variations greatly affect the stiffness

Prevalence of HIV infection in seronegative high-risk individuals examined by virus isolation and PCR

DEFF Research Database (Denmark)

Nielsen, C; Teglbjærg, Lars Stubbe; Pedersen, C

1991-01-01

HIV seronegative individuals with high-risk behavior were tested for HIV infection by sensitive virus isolation techniques using T4 lymphocytes and monocyte/macrophages, and by detection of proviral DNA using PCR with three different sets of nested primers. No evidence of HIV infection was found...... among the 31 seronegative high-risk subjects, either by virus isolation of by PCR (97.5% confidence limits, 0-11). Our results indicate that ongoing HIV infection in seronegative persons at high risk of infection is a rare event....

Geologic isolation of nuclear waste at high latitudes: the role of ice sheets

Science.gov (United States)

Person, M.; McIntosh, J.; Iverson, N.; Neuzil, C.E.; Bense, V.

2012-01-01

Geologic isolation of high-level nuclear waste from the biosphere requires special consideration in countries at high latitudes (>40°N) owing to the possibility of future episodes of continental glaciation (Talbot 1999). It is now widely recognized that Pleistocene continental glaciations have had a profound effect on rates of sediment erosion (Cuffey & Paterson 2010) and deformation including tectonic thrusting (Pedersen 2005) as well as groundwater flow (Person et al. 2007; Lemieux et al. 2008a,b,c). In addition, glacial mechanical loads may have generated anomalous, or fossil, pore pressures within certain clay-rich confining units (e.g. Vinard et al. 2001). Because high-level nuclear wastes must be isolated from the biosphere as long as 1 million years (McMurry et al. 2003), the likelihood of one or more continental ice sheets overrunning high-latitude sites must be considered.

Highly pathogenic avian influenza virus (H5N1) isolated from whooper swans, Japan.

Science.gov (United States)

Uchida, Yuko; Mase, Masaji; Yoneda, Kumiko; Kimura, Atsumu; Obara, Tsuyoshi; Kumagai, Seikou; Saito, Takehiko; Yamamoto, Yu; Nakamura, Kikuyasu; Tsukamoto, Kenji; Yamaguchi, Shigeo

2008-09-01

On April 21, 2008, four whooper swans were found dead at Lake Towada, Akita prefecture, Japan. Highly pathogenic avian influenza virus of the H5N1 subtype was isolated from specimens of the affected birds. The hemagglutinin (HA) gene of the isolate belongs to clade 2.3.2 in the HA phylogenetic tree.

Analysis of clinical isolates of Helicobacter pylori in Pakistan reveals high degrees of pathogenicity and high frequencies of antibiotic resistance.

Science.gov (United States)

Rasheed, Faisal; Campbell, Barry James; Alfizah, Hanafiah; Varro, Andrea; Zahra, Rabaab; Yamaoka, Yoshio; Pritchard, David Mark

2014-10-01

Antibiotic resistance in Helicobacter pylori contributes to failure in eradicating the infection and is most often due to point and missense mutations in a few key genes. The antibiotic susceptibility profiles of H. pylori isolates from 46 Pakistani patients were determined by Etest. Resistance and pathogenicity genes were amplified, and sequences were analyzed to determine the presence of mutations. A high percentage of isolates (73.9%) were resistant to metronidazole (MTZ), with considerable resistance to clarithromycin (CLR; 47.8%) and amoxicillin (AML; 54.3%) also observed. Relatively few isolates were resistant to tetracycline (TET; 4.3%) or to ciprofloxacin (CIP; 13%). However, most isolates (n = 43) exhibited resistance to one or more antibiotics. MTZ-resistant isolates contained missense mutations in oxygen-independent NADPH nitroreductase (RdxA; 8 mutations found) and NADH flavin oxidoreductase (FrxA; 4 mutations found). In the 23S rRNA gene, responsible for CLR resistance, a new point mutation (A2181G) and 4 previously reported mutations were identified. Pathogenicity genes cagA, dupA, and vacA s1a/m1 were detected frequently in isolates which were also found to be resistant to MTZ, CLR, and AML. A high percentage of CagA and VacA seropositivity was also observed in these patients. Phylogenetic analysis of partial sequences showed uniform distribution of the 3' region of cagA throughout the tree. We have identified H. pylori isolates in Pakistan which harbor pathogenicity genes and worrying antibiotic resistance profiles as a result of having acquired multiple point and missense mutations. H. pylori eradication regimens should therefore be reevaluated in this setting. © 2014 John Wiley & Sons Ltd.

Occurrence of aminoglycoside-modifying enzymes among isolates of Escherichia coli exhibiting high levels of aminoglycoside resistance isolated from Korean cattle farms.

Science.gov (United States)

Belaynehe, Kuastros Mekonnen; Shin, Seung Won; Hong-Tae, Park; Yoo, Han Sang

2017-08-01

This study investigated 247 Escherichia coli isolates collected from four cattle farms to characterize aminoglycoside-modifying enzyme (AME) genes, their plasmid replicons and transferability. Out of 247 isolates a high number of isolates (total 202; 81.78%) were found to be resistant to various antibiotics by disc diffusion. Of the 247 strains, 139 (56.3%) were resistant to streptomycin, and other antibiotic resistances followed as tetracycline (12.15%), ampicillin (7%), chloramphenicol (5.7%) and trimethoprim-sulfamethoxazole (0.8%). Among 247 isolates B1 was the predominant phylogenetic group identified comprising 151 isolates (61.1%), followed by groups A (27.9%), D (7%) and B2 (4%). Out of 139 isolates investigated for AME, 130 (93.5%) isolates carried at least one AME gene. aph3″-1a and aph3″-1b (46%) were the principal genes detected, followed by aac3-IVa (34.5%). ant2″-1a was the least detected gene (2.2%). Nine (6.5%) strains carried no AME genes. Twelve (63.2%) among 19 isolates transferred an AME gene to a recipient and aph3΄-1a was the dominant transferred gene. Transferability mainly occurred via the IncFIB replicon type (52.6%). Pulsed-field gel electrophoresis typing demonstrated a higher degree of diversity with 14 distinct cluster types. This result suggests that commensal microflora from food-producing animals has a tremendous ability to harbor and transfer AME genes, and poses a potential risk by dissemination of resistance to humans through the food chain. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

High-grade renal injuries are often isolated in sports-related trauma.

Science.gov (United States)

Patel, Darshan P; Redshaw, Jeffrey D; Breyer, Benjamin N; Smith, Thomas G; Erickson, Bradley A; Majercik, Sarah D; Gaither, Thomas W; Craig, James R; Gardner, Scott; Presson, Angela P; Zhang, Chong; Hotaling, James M; Brant, William O; Myers, Jeremy B

2015-07-01

Most high-grade renal injuries (American Association for Surgery of Trauma (AAST) grades III-V) result from motor vehicle collisions associated with numerous concomitant injuries. Sports-related blunt renal injury tends to have a different mechanism, a solitary blow to the flank. We hypothesized that high-grade renal injury is often isolated in sports-related renal trauma. We identified patients with AAST grades III-V blunt renal injuries from four level 1 trauma centres across the United States between 1/2005 and 1/2014. Patients were divided into "Sport" or "Non-sport" related groups. Outcomes included rates of hypotension (systolic blood pressure 110bpm), concomitant abdominal injury, and procedural/surgical intervention between sports and non-sports related injury. 320 patients met study criteria. 18% (59) were sports-related injuries with the most common mechanisms being skiing, snowboarding and contact sports (25%, 25%, and 24%, respectively). Median age was 24 years for sports and 30 years for non-sports related renal injuries (p=0.049). Males were more commonly involved in sports related injuries (85% vs. 72%, p=0.011). Median injury severity score was lower for sports related injuries (10 vs. 27, pinjury scale scores. Sports related trauma was more likely to be isolated without other significant injury (69% vs. 39% (psports and non-sports renal injuries (p=0.30). Sports injuries had lower transfusion (7% vs. 47%, psports vs. 18% non-sports, p=0.95). High-grade sports-related blunt renal trauma is more likely to occur in isolation without other abdominal or thoracic injuries and clinicians must have a high suspicion of renal injury with significant blows to the flank during sports activities. Copyright © 2015 Elsevier Ltd. All rights reserved.

Antimicrobial susceptibilities and molecular typing of neisseria gonorrhoeae isolates at a medical centre in Taiwan, 2001-2013 with an emphasis on high rate of azithromycin resistance among the isolates.

Science.gov (United States)

Liu, Yen-Hung; Huang, Yu-Tsung; Liao, Chun-Hsing; Hsueh, Po-Ren

2018-05-01

A high prevalence of gonococcal resistance to various antimicrobials and Neisseria gonorrhoeae isolates exhibiting resistance to extended-spectrum cephalosporins have been reported in the past few decades. A total of 226 N. gonorrhoeae isolates obtained from the National Taiwan University Hospital from 2001 to 2013 were evaluated. The minimum inhibitory concentrations (MICs) of the isolates to antimicrobials were determined by the agar dilution method and interpreted using the 2017 clinical breakpoints or epidemiological cut-off values recommended by the Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility Testing (EUCAST). The genetic relatedness of these isolates was determined by multilocus sequence typing. None of the isolates was resistant to ceftriaxone and cefotaxime, and the resistance rates to cefixime, spectinomycin, cefpodoxime, ciprofloxacin, and penicillin were 0.4%, 0.4%, 13.3%, 91.6%, and 87.6%, respectively. The rate of isolates resistant to azithromycin was 14.6% (EUCAST criteria), which is higher than in previous surveillance studies. A total of 57 sequence types (ST) were identified, and ST1901, ST7365, and ST1927 prevailed. Isolates of ST8143 emerged after 2011. ST1901 isolates had relatively higher MIC values for ceftriaxone and azithromycin than those of the other STs. In conclusion, ceftriaxone remains an effective drug of choice for gonorrhoeal management in Taiwan. High rates of azithromycin resistance among N. gonorrhoeae isolates were found. The circulating ST1901 strains with high MIC values for ceftriaxone and azithromycin and the emerging ST8143 strains were alarming. Copyright © 2018 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

High-grade renal injuries are often isolated in sports-related trauma

OpenAIRE

Patel, Darshan P.; Redshaw, Jeffrey D.; Breyer, Benjamin N.; Smith, Thomas G.; Erickson, Bradley A.; Majercik, Sarah D.; Gaither, Thomas W.; Craig, James R.; Gardner, Scott; Presson, Angela P.; Zhang, Chong; Hotaling, James M.; Brant, William O.; Myers, Jeremy B.

2015-01-01

© 2015 Elsevier Ltd. All rights reserved. Introduction: Most high-grade renal injuries (American Association for Surgery of Trauma (AAST) grades III-V) result from motor vehicle collisions associated with numerous concomitant injuries. Sports-related blunt renal injury tends to have a different mechanism, a solitary blow to the flank. We hypothesized that high-grade renal injury is often isolated in sports-related renal trauma. Material and methods: We identified patients with AAST grades III...

High-throughput isolation of giant viruses in liquid medium using automated flow cytometry and fluorescence staining.

Directory of Open Access Journals (Sweden)

Jacques Yaacoub Bou Khalil

2016-01-01

Full Text Available The isolation of giant viruses using amoeba co-culture is tedious and fastidious. Recently, the procedure was successfully associated with a method that detects amoebal lysis on agar plates. However, the procedure remains time-consuming and is limited to protozoa growing on agar. We present here advances for the isolation of giant viruses. A high-throughput automated method based on flow cytometry and fluorescent staining was used to detect the presence of giant viruses in liquid medium. Development was carried out with the Acanthamoeba polyphaga strain widely used in past and current co-culture experiments. The proof of concept was validated with virus suspensions: artificially contaminated samples but also environmental samples from which viruses were previously isolated. After validating the technique, and fortuitously isolating a new Mimivirus, we automated the technique on 96-well plates and tested it on clinical and environmental samples using other protozoa. This allowed us to detect more than ten strains of previously known species of giant viruses and 7 new strains of a new virus lineage. This automated high-throughput method demonstrated significant time saving, and higher sensitivity than older techniques. It thus creates the means to isolate giant viruses at high speed.

Discrimination of Single-Copy IS6110 DNA Fingerprints of Mycobacterium tuberculosis Isolates by High-Resolution Minisatellite-Based Typing

OpenAIRE

Lee, Ann S. G.; Tang, Lynn L. H.; Lim, Irene H. K.; Bellamy, Richard; Wong, Sin-Yew

2002-01-01

Seven isoniazid-resistant isolates with mutations in the NADH dehydrogenase (ndh) gene were molecularly typed by IS6110-based restriction fragment length polymorphism analysis. All seven isolates with the R268H mutation had identical 1.4-kb IS6110 fingerprints. High-resolution minisatellite-based typing discriminated five of these isolates; two isolates were identical.

Discrimination of single-copy IS6110 DNA fingerprints of Mycobacterium tuberculosis isolates by high-resolution minisatellite-based typing.

Science.gov (United States)

Lee, Ann S G; Tang, Lynn L H; Lim, Irene H K; Bellamy, Richard; Wong, Sin-Yew

2002-02-01

Seven isoniazid-resistant isolates with mutations in the NADH dehydrogenase (ndh) gene were molecularly typed by IS6110-based restriction fragment length polymorphism analysis. All seven isolates with the R268H mutation had identical 1.4-kb IS6110 fingerprints. High-resolution minisatellite-based typing discriminated five of these isolates; two isolates were identical.

A Minimized MIMO-UWB Antenna with High Isolation and Triple Band-Notched Functions

Science.gov (United States)

Kong, Yuanyuan; Li, Yingsong; Yu, Kai

2016-11-01

A compact high isolation MIMO-UWB antenna with triple frequency rejection bands is proposed for UWB communication applications. The proposed MIMO-UWB antenna consists of two identical UWB antennas and each antenna element has a semicircle ring shaped radiation patch fed by a bend microstrip feeding line for covering the UWB band, which operates from 2.85 GHz to 11.79 GHz with an impedance bandwidth of 122.1 %. By etching a L-shaped slot on the ground plane, and embedding an "anchor" shaped stub into the patch and integrating an open ring under the semicircle shaped radiation patch, three notch bands are realized to suppress WiMAX (3.3-3.6 GHz), WLAN(5.725-5.825 GHz) and uplink of X-band satellite (7.9-8.4 GHz) signals. The high isolation with S21<-20 dB in most UWB band is obtained by adding a protruded decoupling structure. The design procedure of the MIMO-UWB antenna is given in detail. The proposed MIMO-UWB antenna is simulated, fabricated and measured. Experimental results demonstrate that the proposed MIMO-UWB antenna has a stable gain, good impedance match, high isolation, low envelope correlation coefficient and good radiation pattern at the UWB operating band and it can provide three designated notch bands.

Soy protein isolate inhibits hepatic tumor promotion in mice fed a high-fat liquid diet.

Science.gov (United States)

Mercer, Kelly E; Pulliam, Casey F; Pedersen, Kim B; Hennings, Leah; Ronis, Martin Jj

2017-03-01

Alcoholic and nonalcoholic fatty liver diseases are risk factors for development of hepatocellular carcinoma, but the underlying mechanisms are poorly understood. On the other hand, ingestion of soy-containing diets may oppose the development of certain cancers. We previously reported that replacing casein with a soy protein isolate reduced tumor promotion in the livers of mice with alcoholic liver disease after feeding a high fat ethanol liquid diet following initiation with diethylnitrosamine. Feeding soy protein isolate inhibited processes that may contribute to tumor promotion including inflammation, sphingolipid signaling, and Wnt/β-catenin signaling. We have extended these studies to characterize liver tumor promotion in a model of nonalcoholic fatty liver disease produced by chronic feeding of high-fat liquid diets in the absence of ethanol. Mice treated with diethylnitrosamine on postnatal day 14 were fed a high-fat liquid diet made with casein or SPI as the sole protein source for 16 weeks in adulthood. Relative to mice fed normal chow, a high fat/casein diet led to increased tumor promotion, hepatocyte proliferation, steatosis, and inflammation. Replacing casein with soy protein isolate counteracted these effects. The high fat diets also resulted in a general increase in transcripts for Wnt/β-catenin pathway components, which may be an important mechanism, whereby hepatic tumorigenesis is promoted. However, soy protein isolate did not block Wnt signaling in this nonalcoholic fatty liver disease model. We conclude that replacing casein with soy protein isolate blocks development of steatosis, inflammation, and tumor promotion in diethylnitrosamine-treated mice fed high fat diets. Impact statement The impact of dietary components on cancer is a topic of great interest for both the general public and the scientific community. Liver cancer is currently the second leading form of cancer deaths worldwide. Our study has addressed the effect of the protein

High Prevalence of Multiple Drug Resistance among ESBLs-Producing Klebsiella pneumoniae Isolated from Hospitalized Patients in Isfahan, Iran

Directory of Open Access Journals (Sweden)

Zahra Tahanasab

2017-02-01

Full Text Available Background:   This study was to evaluate the prevalence of CTX-Mand TEM type ESBLs-producing K. pneumoniae and determination of MDR, XDR, and PDR phenotypes of these isolates as well as find out the genetic relationship and molecular typing of these isolates using phenotypic and genotypic methods.Methods:   Non-repetitive 96 K. pneumonia isolates were isolated from hospitalized patients in Al-Zahra hospital of Isfahan, Iran. The antibiotic susceptibility test was assessed for 20 antibiotics using Kirby-Bauer disk diffusion method. The frequency of ESBL-producing isolates was determined by phenotypic confirmatory test. All ESBLs-producing isolates were assessed for blaTEM and blaCTX-M genes using PCR method. Molecular typing was performed by enterobacterial repetitive intergenic consensus sequence-based PCR (ERIC-PCR.Results:  Among 96 isolates, 58 isolates (60.4% were ESBL-producers. In this study, 85.7% and 30.3% of ESBL-producing isolates showed MDR and XDR phenotypes, respectively. No PDR isolate was found. PCR amplification on ESBL-producing isolates showed that 47 (81% isolates were carried blaTEM gene, while blaCTX-M was detected in all isolates (100%. ERIC-PCR typing was characterized the high genetic similarity among ESBL-producing K. pneumonia isolates and revealed 32 band pattern for the isolates. Conclusion:  This study showed high prevalence of important ESBL genes (blaCTX-M and blaTEM genes among the K. pneumoniae isolated from in-patients. Constant following of ESBLs, also identification of their types, in bacteria isolated from hospitalized patients has an important clinical impact. It can provide valuable information for the choice of appropriate antibacterial therapy and decrease of antibiotic resistance.

A safe inexpensive method to isolate high quality plant and fungal ...

African Journals Online (AJOL)

STORAGESEVER

2008-08-18

Aug 18, 2008 ... quality DNA from plant and fungal species. This method uses potassium acetate to remove proteins and polysaccharides in an SDS extraction buffer. Further DNA purification is achieved using a low salt. CTAB treatment. This SDS/CTAB protocol was used to isolate high quality genomic DNA subject to.

Use of Nonspecific, Glutamic Acid-Free, Media and High Glycerol or High Amylase as Inducing Parameters for Screening Bacillus Isolates Having High Yield of Polyglutamic Acid.

Science.gov (United States)

Baxi, Nandita N

2014-01-01

Out of fifty-five Bacillus isolates obtained from ten different regional locations and sources, seven showed the ability to consistently produce specific extracellular polymeric substance (EPS) on rich as well as synthetic but nonspecific media which did not contain glutamic acid. The isolates were identified as either Bacillus licheniformis or Bacillus subtilis. The EPS from all isolates was resistant to alpha protease, proteinase K, and was thus of high molecular weight. Further it was detected after SDS-PAGE by methylene blue but not by coomassie blue R staining as in case of proteins with high proportion of acidic amino acids. Cell-free EPS, after acid hydrolysis, showed absence of carbohydrates and presence of only glutamic acid. Thus the native the EPS from all seven isolates was confirmed to be gamma polyglutamic acid (PGA) and not exopolysaccharide. The Bacillus isolate T which produced maximum polymer on all media tested had higher amylase: protease activity as compared to other strains. If inoculum was developed in rich medium as compared to synthetic medium, the PGA produced increased by twofold in the subsequent synthetic production medium. Similarly, use of inoculum consisting of young and vegetative cells also increased the PGA production by twofold though amount of inoculum did not affect yield of PGA. Though PGA was produced in even in the absence of glutamic acid supplementation in the production medium by all isolates, the yield of PGA increased by fourfold in the presence glutamic acid and the maximum yield was 30 g/l for isolate K. The supplementation of glutamine instead of glutamic acid into the medium caused an increase in the viscosity of the non-Newtonian solution of PGA.

Evaluation of PCR and high-resolution melt curve analysis for differentiation of Salmonella isolates.

Science.gov (United States)

Saeidabadi, Mohammad Sadegh; Nili, Hassan; Dadras, Habibollah; Sharifiyazdi, Hassan; Connolly, Joanne; Valcanis, Mary; Raidal, Shane; Ghorashi, Seyed Ali

2017-06-01

Consumption of poultry products contaminated with Salmonella is one of the major causes of foodborne diseases worldwide and therefore detection and differentiation of Salmonella spp. in poultry is important. In this study, oligonucleotide primers were designed from hemD gene and a PCR followed by high-resolution melt (HRM) curve analysis was developed for rapid differentiation of Salmonella isolates. Amplicons of 228 bp were generated from 16 different Salmonella reference strains and from 65 clinical field isolates mainly from poultry farms. HRM curve analysis of the amplicons differentiated Salmonella isolates and analysis of the nucleotide sequence of the amplicons from selected isolates revealed that each melting curve profile was related to a unique DNA sequence. The relationship between reference strains and tested specimens was also evaluated using a mathematical model without visual interpretation of HRM curves. In addition, the potential of the PCR-HRM curve analysis was evaluated for genotyping of additional Salmonella isolates from different avian species. The findings indicate that PCR followed by HRM curve analysis provides a rapid and robust technique for genotyping of Salmonella isolates to determine the serovar/serotype.

High pathogenicity and strong immunogenicity of a Chinese isolate of Eimeria magna Pérard, 1925.

Science.gov (United States)

Tao, Geru; Wang, Yunzhou; Li, Chao; Gu, Xiaolong; Cui, Ping; Fang, Sufang; Suo, Xun; Liu, Xianyong

2017-06-01

Coccidia infection of rabbits with one or several species of parasites of the genus Eimeria causes coccidiosis, a disease leading to huge economic losses in the rabbit industry. Eimeria magna, one of the causal agents of rabbit coccidiosis, was characterized as mildly pathogenic and moderately immunogenic in previous studies. In this study, we identified a Chinese isolate of E. magna by testing its biological features (oocyst morphology and size, prepatent time) and sequencing its internal transcribed spacer 1 (ITS-1) DNA fragment. This isolate is highly pathogenic; infection of rabbits with only 1×10 2 oocysts caused a 55% reduction in weight gain in 14days. In addition, immunization with 1×10 2 oocysts prevented body weight loss against re-infection with 5×10 4 oocysts, indicating the high immunogenicity of this isolate. Our study described the distinctive phenotype of the Chinese isolate of E. magna and contributed to the research of geographic variation of rabbit coccidia. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis and wafer-level design of a high-order silicon vibration isolator for resonating MEMS devices

International Nuclear Information System (INIS)

Yoon, Sang Won; Lee, Sangwoo; Najafi, Khalil; Perkins, Noel C

2011-01-01

This paper presents the analysis and preliminary design, fabrication, and measurement for mechanical vibration-isolation platforms especially designed for resonating MEMS devices including gyroscopes. Important parameters for designing isolation platforms are specified and the first platform (in designs with cascaded multiple platforms) is crucial for improving vibration-isolation performance and minimizing side-effects on integrated gyroscopes. This isolation platform, made from a thick silicon wafer substrate for an environment-resistant MEMS package, incorporates the functionalities of a previous design including vacuum packaging and thermal resistance with no additional resources. This platform consists of platform mass, isolation beams, vertical feedthroughs, and bonding pads. Two isolation platform designs follow from two isolation beam designs: lateral clamped–clamped beams and vertical torsion beams. The beams function simultaneously as mechanical springs and electrical interconnects. The vibration-isolation platform can yield a multi-dimensional, high-order mechanical low pass filter. The isolation platform possesses eight interconnects within a 12.2 × 12.2 mm 2 footprint. The contact resistance ranges from 4–11 Ω depending on the beam design. Vibration measurements using a laser-Doppler vibrometer demonstrate that the lateral vibration-isolation platform suppresses external vibration having frequencies exceeding 2.1 kHz.

Isolation of xanthyletin, an inhibitor of ants' symbiotic fungus, by high-speed counter-current chromatography.

Science.gov (United States)

Cazal, Cristiane de Melo; Domingues, Vanessa de Cássia; Batalhão, Jaqueline Raquel; Bueno, Odair Corrêa; Filho, Edson Rodrigues; da Silva, Maria Fátima G Fernandes; Vieira, Paulo Cezar; Fernandes, João Batista

2009-05-08

Xanthyletin, an inhibitor of symbiotic fungus (Leucoagaricus gongylophorus) of leaf-cutting ant (Atta sexdens rubropilosa), as well as suberosin, seselin and xanthoxyletin were isolated from Citrus sinensis grafted on Citrus limonia. A two-phase solvent system composed of hexane/ethanol/acetonitrile/water (10:8:1:1, v/v) was used for the high-speed counter-current chromatographic isolation of xanthyletin with high yield and over 99% purity as determined by liquid and gas chromatography with mass spectrometry detection. Identifications were performed by UV spectra, IR spectra, (1)H NMR and (13)C NMR.

A high-throughput splinkerette-PCR method for the isolation and sequencing of retroviral insertion sites

DEFF Research Database (Denmark)

Uren, Anthony G; Mikkers, Harald; Kool, Jaap

2009-01-01

sites has been a major limitation to performing screens on this scale. Here we present a method for the high-throughput isolation of insertion sites using a highly efficient splinkerette-PCR method coupled with capillary or 454 sequencing. This protocol includes a description of the procedure for DNA......Insertional mutagens such as viruses and transposons are a useful tool for performing forward genetic screens in mice to discover cancer genes. These screens are most effective when performed using hundreds of mice; however, until recently, the cost-effective isolation and sequencing of insertion...

A Stewart isolator with high-static-low-dynamic stiffness struts based on negative stiffness magnetic springs

Science.gov (United States)

Zheng, Yisheng; Li, Qingpin; Yan, Bo; Luo, Yajun; Zhang, Xinong

2018-05-01

In order to improve the isolation performance of passive Stewart platforms, the negative stiffness magnetic spring (NSMS) is employed to construct high static low dynamic stiffness (HSLDS) struts. With the NSMS, the resonance frequencies of the platform can be reduced effectively without deteriorating its load bearing capacity. The model of the Stewart isolation platform with HSLDS struts is presented and the stiffness characteristic of its struts is studied firstly. Then the nonlinear dynamic model of the platform including both geometry nonlinearity and stiffness nonlinearity is established; and its simplified dynamic model is derived under the condition of small vibration. The effect of nonlinearity on the isolation performance is also evaluated. Finally, a prototype is built and the isolation performance is tested. Both simulated and experimental results demonstrate that, by using the NSMS, the resonance frequencies of the Stewart isolator are reduced and the isolation performance in all six directions is improved: the isolation frequency band is increased and extended to a lower-frequency level.

Chem I Supplement. Chemistry Related to Isolation of High-Level Nuclear Waste.

Science.gov (United States)

Hoffman, Darleane C.; Choppin, Gregory R.

1986-01-01

Discusses some of the problems associated with the safe disposal of high-level nuclear wastes. Describes several waste disposal plans developed by various nations. Outlines the multiple-barrier concept of isolation in deep geological questions associated with the implementation of such a method. (TW)

Matrix isolation-infrared and mass spectrometric studies of high-temperature molecules

International Nuclear Information System (INIS)

Dickinson, S.

1987-08-01

Matrix isolation-infrared spectroscopy and mass spectrometry have been developed at AEE Winfrith to study the high-temperature vapour species which could be generated during a hypothetical severe reactor accident. The principles of the techniques and the instruments are described in detail, and examples of their application to specific systems discussed. Although these examples refer to high-temperature chemical species which are relevant to reactor safety assessments, the techniques are equally applicable to other processes where the characterisation of transient vapour-phase species is required. (author)

High depth, whole-genome sequencing of cholera isolates from Haiti and the Dominican Republic.

Science.gov (United States)

Sealfon, Rachel; Gire, Stephen; Ellis, Crystal; Calderwood, Stephen; Qadri, Firdausi; Hensley, Lisa; Kellis, Manolis; Ryan, Edward T; LaRocque, Regina C; Harris, Jason B; Sabeti, Pardis C

2012-09-11

Whole-genome sequencing is an important tool for understanding microbial evolution and identifying the emergence of functionally important variants over the course of epidemics. In October 2010, a severe cholera epidemic began in Haiti, with additional cases identified in the neighboring Dominican Republic. We used whole-genome approaches to sequence four Vibrio cholerae isolates from Haiti and the Dominican Republic and three additional V. cholerae isolates to a high depth of coverage (>2000x); four of the seven isolates were previously sequenced. Using these sequence data, we examined the effect of depth of coverage and sequencing platform on genome assembly and identification of sequence variants. We found that 50x coverage is sufficient to construct a whole-genome assembly and to accurately call most variants from 100 base pair paired-end sequencing reads. Phylogenetic analysis between the newly sequenced and thirty-three previously sequenced V. cholerae isolates indicates that the Haitian and Dominican Republic isolates are closest to strains from South Asia. The Haitian and Dominican Republic isolates form a tight cluster, with only four variants unique to individual isolates. These variants are located in the CTX region, the SXT region, and the core genome. Of the 126 mutations identified that separate the Haiti-Dominican Republic cluster from the V. cholerae reference strain (N16961), 73 are non-synonymous changes, and a number of these changes cluster in specific genes and pathways. Sequence variant analyses of V. cholerae isolates, including multiple isolates from the Haitian outbreak, identify coverage-specific and technology-specific effects on variant detection, and provide insight into genomic change and functional evolution during an epidemic.

High depth, whole-genome sequencing of cholera isolates from Haiti and the Dominican Republic

Directory of Open Access Journals (Sweden)

Sealfon Rachel

2012-09-01

Full Text Available Abstract Background Whole-genome sequencing is an important tool for understanding microbial evolution and identifying the emergence of functionally important variants over the course of epidemics. In October 2010, a severe cholera epidemic began in Haiti, with additional cases identified in the neighboring Dominican Republic. We used whole-genome approaches to sequence four Vibrio cholerae isolates from Haiti and the Dominican Republic and three additional V. cholerae isolates to a high depth of coverage (>2000x; four of the seven isolates were previously sequenced. Results Using these sequence data, we examined the effect of depth of coverage and sequencing platform on genome assembly and identification of sequence variants. We found that 50x coverage is sufficient to construct a whole-genome assembly and to accurately call most variants from 100 base pair paired-end sequencing reads. Phylogenetic analysis between the newly sequenced and thirty-three previously sequenced V. cholerae isolates indicates that the Haitian and Dominican Republic isolates are closest to strains from South Asia. The Haitian and Dominican Republic isolates form a tight cluster, with only four variants unique to individual isolates. These variants are located in the CTX region, the SXT region, and the core genome. Of the 126 mutations identified that separate the Haiti-Dominican Republic cluster from the V. cholerae reference strain (N16961, 73 are non-synonymous changes, and a number of these changes cluster in specific genes and pathways. Conclusions Sequence variant analyses of V. cholerae isolates, including multiple isolates from the Haitian outbreak, identify coverage-specific and technology-specific effects on variant detection, and provide insight into genomic change and functional evolution during an epidemic.

Pulmonary Vein Isolation by High Intensity Focused Ultrasound

Directory of Open Access Journals (Sweden)

Matthias Antz

2007-04-01

Full Text Available Pulmonary vein isolation (PVI using radiofrequency current (RFC ablation is a potentially curative treatment option for patients with atrial fibrillation (AF. The shortcomings of the RFC technology (technically challenging, long procedure times, complications steadily kindle the interest in new energy sources and catheter designs. High intensity focused ultrasound (HIFU has the ability to precisely focus ultrasound waves in a defined area with a high energy density. HIFU balloon catheters (BC positioned at the PV ostia appear to be an ideal tool to transmit the ablation energy in a circumferential manner to the PV ostia and may therefore bear substantial advantage over conventional ablation catheters in PVI procedures. In clinical trials the HIFU BC has shown promising success rates similar to RFC catheter ablation for PVI in patients with AF. However, procedure times are still long and serious complications have been observed. Therefore, it may be a valuable alternative to the conventional techniques in selected patients but further clinical trials have to be initiated.

High Resolution 3D Experimental Investigation of Flow Structures and Turbulence Statistics in the Viscous and Buffer Layer

Science.gov (United States)

Sheng, Jian; Malkiel, Edwin; Katz, Joseph

2006-11-01

Digital Holographic Microscopy is implemented to perform 3D velocity measurement in the near-wall region of a turbulent boundary layer in a square channel over a smooth wall at Reτ=1,400. The measurements are performed at a resolution of ˜1μm over a sample volume of 1.5x2x1.5mm (x^+=50, y^+=60, z^+=50), sufficient for resolving buffer layer structures and for measuring the instantaneous wall shear stress distributions from velocity gradients in the sublayer. The data provides detailed statistics on the spatial distribution of both wall shear stress components along with the characteristic flow structures, including streamwise counter-rotating vortex pairs, multiple streamwise vortices, and rare hairpins. Conditional sampling identifies characteristic length scales of 70 wall units in spanwise and 10 wall units in wall-normal direction. In the region of high stress, the conditionally averaged flow consists of a stagnation-like sweeping motion induced by a counter rotating pair of streamwise vortices. Regions with low stress are associated with ejection motion, also generated by pairs of counter-rotating vortices. Statistics on the local strain and geometric alignment between strain and vorticity shows that the high shear generating vortices are inclined at 45 to streamwise direction, indicating that vortices are being stretched. Results of on-going analysis examines statistics of helicity, strain and impacts of near-wall structures.

Isolation facilities for highly infectious diseases in Europe--a cross-sectional analysis in 16 countries.

Directory of Open Access Journals (Sweden)

Stefan Schilling

Full Text Available BACKGROUND: Highly Infectious Diseases (HIDs are (i easily transmissible form person to person; (ii cause a life-threatening illness with no or few treatment options; and (iii pose a threat for both personnel and the public. Hence, even suspected HID cases should be managed in specialised facilities minimizing infection risks but allowing state-of-the-art critical care. Consensus statements on the operational management of isolation facilities have been published recently. The study presented was set up to compare the operational management, resources, and technical equipment among European isolation facilities. Due to differences in geography, population density, and national response plans it was hypothesized that adherence to recommendations will vary. METHODS AND FINDINGS: Until mid of 2010 the European Network for Highly Infectious Diseases conducted a cross-sectional analysis of isolation facilities in Europe, recruiting 48 isolation facilities in 16 countries. Three checklists were disseminated, assessing 44 items and 148 specific questions. The median feedback rate for specific questions was 97.9% (n = 47/48 (range: n = 7/48 (14.6% to n = 48/48 (100%. Although all facilities enrolled were nominated specialised facilities' serving countries or regions, their design, equipment and personnel management varied. Eighteen facilities fulfilled the definition of a High Level Isolation Unit'. In contrast, 24 facilities could not operate independently from their co-located hospital, and five could not ensure access to equipment essential for infection control. Data presented are not representative for the EU in general, as only 16/27 (59.3% of all Member States agreed to participate. Another limitation of this study is the time elapsed between data collection and publication; e.g. in Germany one additional facility opened in the meantime. CONCLUSION: There are disparities both within and between European countries regarding the design

Cluster of Neisseria gonorrhoeae Isolates With High-level Azithromycin Resistance and Decreased Ceftriaxone Susceptibility, Hawaii, 2016.

Science.gov (United States)

Katz, Alan R; Komeya, Alan Y; Kirkcaldy, Robert D; Whelen, A Christian; Soge, Olusegun O; Papp, John R; Kersh, Ellen N; Wasserman, Glenn M; O'Connor, Norman P; O'Brien, Pamela S; Sato, Douglas T; Maningas, Eloisa V; Kunimoto, Gail Y; Tomas, Juval E

2017-09-15

The Centers for Disease Control and Prevention (CDC) currently recommends dual therapy with ceftriaxone and azithromycin for gonorrhea to ensure effective treatment and slow emergence of antimicrobial resistance. Since 2013, the prevalence of reduced azithromycin susceptibility increased in the United States; however, these strains were highly susceptible to cephalosporins. We identified a cluster of Neisseria gonorrhoeae isolates with high-level azithromycin resistance, several of which also demonstrated decreased ceftriaxone susceptibility. Eight N. gonorrhoeae isolates collected from 7 patients on Oahu, Hawaii, seen 21 April 2016 through 10 May 2016 underwent routine Etest antimicrobial susceptibility testing by the Hawaii Department of Health. All demonstrated elevated azithromycin minimum inhibitory concentrations (MICs) >256 μg/mL and elevated ceftriaxone MICs (≥0.125 μg/mL). Isolates were sent to the University of Washington and CDC for confirmatory agar dilution testing; sequence data were sent to CDC for analysis. All patients were interviewed and treated, and when possible, partners were interviewed, tested, and treated. All isolates had azithromycin MICs >16 µg/mL and 5 had ceftriaxone MICs = 0.125 µg/mL by agar dilution. All isolates were β-lactamase positive and were resistant to penicillin, tetracycline, and ciprofloxacin. Genomic analysis revealed genetic relatedness. No patients reported recent travel or antibiotic use, and no male patients reported male sex partners. All patients were successfully treated. This cluster of genetically related gonococcal isolates with decreased ceftriaxone susceptibility and high-level azithromycin resistance may bring the threat of treatment failure in the United States with the current recommended dual therapy one step closer. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

High frequency of silver resistance genes in invasive isolates of Enterobacter and Klebsiella species.

Science.gov (United States)

Sütterlin, S; Dahlö, M; Tellgren-Roth, C; Schaal, W; Melhus, Å

2017-07-01

Silver-based products have been marketed as an alternative to antibiotics, and their consumption has increased. Bacteria may, however, develop resistance to silver. To study the presence of genes encoding silver resistance (silE, silP, silS) over time in three clinically important Enterobacteriaceae genera. Using polymerase chain reaction (PCR), 752 bloodstream isolates from the years 1990-2010 were investigated. Age, gender, and ward of patients were registered, and the susceptibility to antibiotics and silver nitrate was tested. Clonality and single nucleotide polymorphism were assessed with repetitive element sequence-based PCR, multi-locus sequence typing, and whole-genome sequencing. Genes encoding silver resistance were detected most frequently in Enterobacter spp. (48%), followed by Klebsiella spp. (41%) and Escherichia coli 4%. Phenotypical resistance to silver nitrate was found in Enterobacter (13%) and Klebsiella (3%) isolates. The lowest carriage rate of sil genes was observed in blood isolates from the neonatology ward (24%), and the highest in blood isolates from the oncology/haematology wards (66%). Presence of sil genes was observed in international high-risk clones. Sequences of the sil and pco clusters indicated that a single mutational event in the silS gene could have caused the phenotypic resistance. Despite a restricted consumption of silver-based products in Swedish health care, silver resistance genes are widely represented in clinical isolates of Enterobacter and Klebsiella species. To avoid further selection and spread of silver-resistant bacteria with a high potential for healthcare-associated infections, the use of silver-based products needs to be controlled and the silver resistance monitored. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Systems and methods for enhancing isolation of high-temperature reactor containments

Energy Technology Data Exchange (ETDEWEB)

Peterson, Per F.

2017-09-26

A high-temperature containment-isolation system for transferring heat from a nuclear reactor containment to a high-pressure heat exchanger is presented. The system uses a high-temperature, low-volatility liquid coolant such as a molten salt or a liquid metal, where the coolant flow path provides liquid free surfaces a short distance from the containment penetrations for the reactor hot-leg and the cold-leg, where these liquid free surfaces have a cover gas maintained at a nearly constant pressure and thus prevent high-pressures from being transmitted into the reactor containment, and where the reactor vessel is suspended within a reactor cavity with a plurality of refractory insulator blocks disposed between an actively cooled inner cavity liner and the reactor vessel.

Effect of high fat and high sugar diet on insulin binding and insulin action in isolated rat adipocytes

OpenAIRE

岡﨑,悟

1987-01-01

To clarify on a cellular basis the mechanism of the diabetogenic effect of the westernized diet, insulin binding, insulin stimulated 3-o-methylglucose uptake and glucose oxidation were studied in isolated adipocytes from rats fed experimental diets : low fat-no sugar diet (energy ratio of 10% fat, 70% starch, a model of the traditional Japanese diet), high fat-high sugar diet (40% fat, 20% starch, 20% sugar, a model of the westernized diet), low fat-high sugar diet (10% fat, 50% starch, 20% s...

Characterization of high temperature-tolerant rhizobia isolated from Prosopis juliflora grown in alkaline soil.

Science.gov (United States)

Kulkarni, Suneeta; Nautiyal, Chandra Shekhar

1999-10-01

A method was developed for the fast screening and selection of high-temperature tolerant rhizobial strains from root nodules of Prosopis juliflora growing in alkaline soils. The high-temperature tolerant rhizobia were selected from 2,500 Rhizobium isolates with similar growth patterns on yeast mannitol agar plates after 72 h incubation at 30 and 45 degrees C, followed by a second screening at 47.5 degrees C. Seventeen high-temperature tolerant rhizobial strains having distinguishable protein band patterns were finally selected for further screening by subjecting them to temperature stress up to 60 degrees C in yeast mannitol broth for 6 h. The high-temperature tolerant strains were NBRI12, NBRI329, NBRI330, NBRI332, and NBRI133. Using this procedure, a large number of rhizobia from root nodules of P. juliflora were screened for high-temperature tolerance. The assimilation of several carbon sources, tolerance to high pH and salt stress, and ability to nodulate P. juliflora growing in a glasshouse and nursery of the strains were studied. All five isolates had higher plant dry weight in the range of 29.9 to 88.6% in comparison with uninoculated nursery-grown plants. It was demonstrated that it is possible to screen in nature for superior rhizobia exemplified by the isolation of temperature-tolerant strains, which established effective symbiosis with nursery-grown P. juliflora. These findings indicate a correlation between strain performance under in vitro stress in pure culture and strain behavior under symbiotic conditions. Pure culture evaluation may be a useful tool in search for Rhizobium strains better suited for soil environments where high temperature, pH, and salt stress constitutes a limitation for symbiotic biological nitrogen fixation.

High-throughput genome sequencing of two Listeria monocytogenes clinical isolates during a large foodborne outbreak

Directory of Open Access Journals (Sweden)

Trout-Yakel Keri M

2010-02-01

Full Text Available Abstract Background A large, multi-province outbreak of listeriosis associated with ready-to-eat meat products contaminated with Listeria monocytogenes serotype 1/2a occurred in Canada in 2008. Subtyping of outbreak-associated isolates using pulsed-field gel electrophoresis (PFGE revealed two similar but distinct AscI PFGE patterns. High-throughput pyrosequencing of two L. monocytogenes isolates was used to rapidly provide the genome sequence of the primary outbreak strain and to investigate the extent of genetic diversity associated with a change of a single restriction enzyme fragment during PFGE. Results The chromosomes were collinear, but differences included 28 single nucleotide polymorphisms (SNPs and three indels, including a 33 kbp prophage that accounted for the observed difference in AscI PFGE patterns. The distribution of these traits was assessed within further clinical, environmental and food isolates associated with the outbreak, and this comparison indicated that three distinct, but highly related strains may have been involved in this nationwide outbreak. Notably, these two isolates were found to harbor a 50 kbp putative mobile genomic island encoding translocation and efflux functions that has not been observed in other Listeria genomes. Conclusions High-throughput genome sequencing provided a more detailed real-time assessment of genetic traits characteristic of the outbreak strains than could be achieved with routine subtyping methods. This study confirms that the latest generation of DNA sequencing technologies can be applied during high priority public health events, and laboratories need to prepare for this inevitability and assess how to properly analyze and interpret whole genome sequences in the context of molecular epidemiology.

High-level radioactive waste isolation by incorporation in silicate rock

International Nuclear Information System (INIS)

Schwartz, L.L.; Cohen, J.J.; Lewis, A.E.; Braun, R.L.

1978-01-01

A number of technical possibilities for isolating high-level radioactive materials have been theoretically investigated at various times and places. Isolating such wastes deep underground to ensure long term removal from the biosphere is one such possibility. The present concept involves as a first step creating the necessary void space at considerable depth, say 2 to 5 km, in a very-low-permeability silicate medium such as shale. Waste in dry, calcined or vitrified form is then lowered into the void space, and the access hole or shaft sealed. Energy released by the radioactive decay raises the temperature to a point where the surrounding rock begins to melt. The waste is then dissolved in it. The extent of this melt region grows until the heat generated is balanced by conduction away from the molten zone. Resolidification then begins, and ends when the radioactive decay has progressed to the point that the temperature falls below the melting point of the rock-waste solution. Calculations are presented showing the growth and resolidification process. A nuclear explosion is one way of creating the void space. (author)

Efficient methods for isolating five phytochemicals from Gentiana macrophylla using high-performance countercurrent chromatography.

Science.gov (United States)

Rho, Taewoong; Jung, Mila; Lee, Min Won; Chin, Young-Won; Yoon, Kee Dong

2016-12-01

Efficient high-performance countercurrent chromatography methods were developed to isolate five typical compounds from the extracts of Gentiana macrophylla. n-Butanol-soluble extract of G. macrophylla contained three hydrophilic iridoids, loganic acid (1), swertiamarin (2) and gentiopicroside (3), and a chromene derivative, macrophylloside D (4) which were successfully isolated by flow rate gradient (1.5 mL/min in 0-60 min, 5.0 mL/min in 60-120 min), and consecutive flow rate gradient HPCCC using n-butanol/0.1% aqueous trifluoroacetic acid (1:1, v/v, normal phase mode) system. The yields of 1-4 were 22, 16, 122, and 6 mg, respectively, with purities over 97% in a flow rate gradient high-performance countercurrent chromatography, and consecutive flow rate gradient high-performance countercurrent chromatography gave 1, 2, 3 (54, 41, 348 mg, respectively, purities over 97%) and 4 (13 mg, purity at 95%) from 750 mg of sample. The main compound in methylene chloride soluble extract, 2-methoxyanofinic acid, was successfully separated by n-hexane/ethyl acetate/methanol/water (4:6:4:6, v/v/v/v, flow-rate: 4 mL/min, reversed phase mode) condition. The structures of five isolates were elucidated by 1 H, 13 C NMR and ESI-Q-TOF-MS spectroscopic data which were compared with previously reported values. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chromatographic Monoliths for High-Throughput Immunoaffinity Isolation of Transferrin from Human Plasma

Directory of Open Access Journals (Sweden)

Irena Trbojević-Akmačić

2016-06-01

Full Text Available Changes in protein glycosylation are related to different diseases and have a potential as diagnostic and prognostic disease biomarkers. Transferrin (Tf glycosylation changes are common marker for congenital disorders of glycosylation. However, biological interindividual variability of Tf N-glycosylation and genes involved in glycosylation regulation are not known. Therefore, high-throughput Tf isolation method and large scale glycosylation studies are needed in order to address these questions. Due to their unique chromatographic properties, the use of chromatographic monoliths enables very fast analysis cycle, thus significantly increasing sample preparation throughput. Here, we are describing characterization of novel immunoaffinity-based monolithic columns in a 96-well plate format for specific high-throughput purification of human Tf from blood plasma. We optimized the isolation and glycan preparation procedure for subsequent ultra performance liquid chromatography (UPLC analysis of Tf N-glycosylation and managed to increase the sensitivity for approximately three times compared to initial experimental conditions, with very good reproducibility. This work is licensed under a Creative Commons Attribution 4.0 International License.

The SPES High Power ISOL production target

Science.gov (United States)

Andrighetto, A.; Corradetti, S.; Ballan, M.; Borgna, F.; Manzolaro, M.; Scarpa, D.; Monetti, A.; Rossignoli, M.; Silingardi, R.; Mozzi, A.; Vivian, G.; Boratto, E.; De Ruvo, L.; Sattin, N.; Meneghetti, G.; Oboe, R.; Guerzoni, M.; Margotti, A.; Ferrari, M.; Zenoni, A.; Prete, G.

2016-11-01

SPES (Selective Production of Exotic Species) is a facility under construction at INFN-LNL (Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro), aimed to produce intense neutron-rich radioactive ion beams (RIBs). These will be obtained using the ISOL (Isotope Separation On-Line) method, bombarding a uranium carbide target with a proton beam of 40MeV energy and currents up to 200μA. The target configuration was designed to obtain a high number of fissions, up to 1013 per second, low power deposition and fast release of the produced isotopes. The exotic isotopes generated in the target are ionized, mass separated and re-accelerated by the ALPI superconducting LINAC at energies of 10AMeV and higher, for masses in the region of A = 130 amu , with an expected rate on the secondary target up to 109 particles per second. In this work, recent results on the R&D activities regarding the SPES RIB production target-ion source system are reported.

Isolation, pointing, and suppression (IPS) system for high-performance spacecraft

Science.gov (United States)

Hindle, Tim; Davis, Torey; Fischer, Jim

2007-04-01

Passive mechanical isolation is often times the first step taken to remedy vibration issues on-board a spacecraft. In many cases, this is done with a hexapod of axial members or struts to obtain the desired passive isolation in all six degrees-of-freedom (DOF). In some instances, where the disturbance sources are excessive or the payload is particularly sensitive to vibration, additional steps are taken to improve the performance beyond that of passive isolation. Additional performance or functionality can be obtained with the addition of active control, using a hexapod of hybrid (passive/active) elements at the interface between the payload and the bus. This paper describes Honeywell's Isolation, Pointing, and Suppression (IPS) system. It is a hybrid isolation system designed to isolate a sensitive spacecraft payload with very low passive resonant break frequencies while affording agile independent payload pointing, on-board payload disturbance rejection, and active isolation augmentation. This system is an extension of the work done on Honeywell's previous Vibration Isolation, Steering, and Suppression (VISS) flight experiment. Besides being designed for a different size payload than VISS, the IPS strut includes a dual-stage voice coil design for improved dynamic range as well as improved low-noise drive electronics. In addition, the IPS struts include integral load cells, gap sensors, and payloadside accelerometers for control and telemetry purposes. The associated system-level control architecture to accomplish these tasks is also new for this program as compared to VISS. A summary of the IPS system, including analysis and hardware design, build, and single axis bipod testing will be reviewed.

Isolation of a highly pathogenic influenza virus from turkeys.

Science.gov (United States)

McNulty, M S; Allan, G M; McCracken, R M; McParland, P J

1985-01-01

An influenza virus was isolated from turkeys with an acute disease causing 30% mortality. The virus was subtyped as H5 N8. The nomenclature A/turkey/Ireland/83 (H5 N8) is proposed for this isolate. The virus had an ICPI of 1.80 to 1.85 for 1-day-old chicks and an IVPI of 2.74 for 6-week-old chickens. Following oronasal inoculation of juvenile and adult turkeys, chickens and ducks with the isolate, 100% mortality occurred in turkeys and chickens. No clinical signs were observed in inoculated ducks, but all developed serum antibody titres against the virus.

Isolation and evaluation of a high H{sub 2}-producing lab isolate from cow dung

Energy Technology Data Exchange (ETDEWEB)

Pandey, Anjana; Sinha, Pallavi [Nanotechnology and Molecular Biology Lab, Department of Biotechnology, University of Allahabad, Allahabad-211002, Uttar Pradesh (India); Kotay, Shireen Meher; Das, Debabrata [Department of Biotechnology, Indian Institute of Technology, Kharagpur-721302, West Bengal (India)

2009-09-15

Hydrogen producing bacterial strain was isolated from Indian cow dung and identified of the bacterial family Enterobacteriaceae. This lab isolate was differentiated from Citrobacter Y-19 at molecular level by using RAPD, PCR based technique, and OPO-03{sub 460} and OPO-17{sub 800} RAPD marker for this specific strain (lab isolate) was identified. Fermentative studies were investigated for important parameters, starting with pH of the culture, temperature, inoculum age and inoculum volume, initial substrate concentration and different substrates. Among different substrates, dextrose and sucrose were the preferred substrates for hydrogen production. The optimal starting pH of the culture was found to be 5.0. The H{sub 2} production increased with increase in temperature up to 30 C. The maximum value of H{sub 2} production was recorded when inoculum volume was 12.5% of the culture broth and inoculum age was 14 h. Under batch fermentation conditions, the maximum hydrogen production rate and yield were 355.2 ml l{sup -1} h{sup -1} and 2.1 mol/mol glucose (conversion 35%), respectively. These results indicate that this lab isolate is an ideal hydrogen producer. (author)

Characterizing clinical isolates of Acanthamoeba castellanii with high resistance to polyhexamethylene biguanide in Taiwan

Directory of Open Access Journals (Sweden)

Fu-Chin Huang

2017-10-01

Conclusion: Our results confirm the existence of clinical isolates of A. castellanii with high resistance to PHMB in Taiwan and present the alternative drug tolerance of A. castellanii in addition to the transformation of pseudocyst/cyst.

Non-periodic multi-slit masking for a single counter rotating 2-disc chopper and channeling guides for high resolution and high intensity neutron TOF spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Bartkowiak, M.; Hofmann, T.; Stüßer, N.

2017-02-01

Energy resolution is an important design goal for time-of-flight instruments and neutron spectroscopy. For high-resolution applications, it is required that the burst times of choppers be short, going down to the µs-range. To produce short pulses while maintaining high neutron flux, we propose beam masks with more than two slits on a counter-rotating 2-disc chopper, behind specially adapted focusing multi-channel guides. A novel non-regular arrangement of the slits ensures that the beam opens only once per chopper cycle, when the masks are congruently aligned. Additionally, beam splitting and intensity focusing by guides before and after the chopper position provide high intensities even for small samples. Phase-space analysis and Monte Carlo simulations on examples of four-slit masks with adapted guide geometries show the potential of the proposed setup.

Isolated transient aphasia at emergency presentation is associated with a high rate of cardioembolic embolism.

Science.gov (United States)

Wasserman, Jason K; Perry, Jeffrey J; Dowlatshahi, Dar; Stotts, Grant; Sivilotti, Marco L A; Worster, Andrew; Emond, Marcel; Sutherland, Jane; Stiell, Ian G; Sharma, Mukul

2015-11-01

A cardiac source is often implicated in strokes where the deficit includes aphasia. However, less is known about the etiology of isolated aphasia during transient ischemic attack (TIA). Our objective was to determine whether patients with isolated aphasia are likely to have a cardioembolic etiology for their TIA. We prospectively studied a cohort of TIA patients in eight tertiary-care emergency departments. Patients with isolated aphasia were identified by the treating physician at the time of emergency department presentation. Patients with dysarthria (i.e., a phonation disturbance) were not included. Potential cardiac sources for embolism were defined as atrial fibrillation on history, electrocardiogram, Holter monitor, atrial fibrillation on echocardiography, or thrombus on echocardiography. Of the 2,360 TIA patients identified, 1,155 had neurological deficits at the time of the emergency physician assessment and were included in this analysis, and 41 had isolated aphasia as their only neurological deficit. Patients with isolated aphasia were older (73.9±10.0 v. 67.2±14.5 years; p=0.003), more likely to have a history of heart failure (9.8% v. 2.6%; p=0.027), and were twice as likely to have any cardiac source of embolism (22.0% v. 10.6%; p=0.037). Isolated aphasia is associated with a high rate of cardioembolic sources of embolism after TIA. Emergency patients with isolated aphasia diagnosed with a TIA warrant a rapid and thorough assessment for a cardioembolic source.

Experimental Investigation of a Base Isolation System Incorporating MR Dampers with the High-Order Single Step Control Algorithm

Directory of Open Access Journals (Sweden)

Weiqing Fu

2017-03-01

Full Text Available The conventional isolation structure with rubber bearings exhibits large deformation characteristics when subjected to infrequent earthquakes, which may lead to failure of the isolation layer. Although passive dampers can be used to reduce the layer displacement, the layer deformation and superstructure acceleration responses will increase in cases of fortification earthquakes or frequently occurring earthquakes. In addition to secondary damages and loss of life, such excessive displacement results in damages to the facilities in the structure. In order to overcome these shortcomings, this paper presents a structural vibration control system where the base isolation system is composed of rubber bearings with magnetorheological (MR damper and are regulated using the innovative control strategy. The high-order single-step algorithm with continuity and switch control strategies are applied to the control system. Shaking table test results under various earthquake conditions indicate that the proposed isolation method, compared with passive isolation technique, can effectively suppress earthquake responses for acceleration of superstructure and deformation within the isolation layer. As a result, this structural control method exhibits excellent performance, such as fast computation, generic real-time control, acceleration reduction and high seismic energy dissipation etc. The relative merits of the continuity and switch control strategies are also compared and discussed.

High Rates of Non-Tuberculous Mycobacteria Isolation in Mozambican Children with Presumptive Tuberculosis.

Directory of Open Access Journals (Sweden)

Elisa López-Varela

Full Text Available Non-tuberculous mycobacteria (NTM can cause disease which can be clinically and radiologically undistinguishable from tuberculosis (TB, posing a diagnostic and therapeutic challenge in high TB settings. We aim to describe the prevalence of NTM isolation and its clinical characteristics in children from rural Mozambique.This study was part of a community TB incidence study in children <3 years of age. Gastric aspirate and induced sputum sampling were performed in all presumptive TB cases and processed for smear testing using fluorochrome staining and LED Microscopy, liquid and solid culture, and molecular identification by GenoType® Mycobacterium CM/AS assays.NTM were isolated in 26.3% (204/775 of children. The most prevalent NTM species was M. intracellulare (N = 128, followed by M. scrofulaceum (N = 35 and M. fortuitum (N = 9. Children with NTM were significantly less symptomatic and less likely to present with an abnormal chest radiograph than those with M. tuberculosis. NTM were present in 21.6% of follow-up samples and 25 children had the same species isolated from ≥2 separate samples. All were considered clinically insignificant and none received specific treatment. Children with NTM isolates had equal all cause mortality and likelihood of TB treatment as those with negative culture although they were less likely to have TB ruled out.NTM isolation is frequent in presumptive TB cases but was not clinically significant in this patient cohort. However, it can contribute to TB misdiagnosis. Further studies are needed to understand the epidemiology and the clinical significance of NTM in children.

Vortex Generator Induced Flow in a High Re Boundary Layer

DEFF Research Database (Denmark)

Velte, Clara Marika; Braud, C.; Coudert, S.

2014-01-01

Stereoscopic Particle Image Velocimetry measurements have been conducted in cross-planes behind three different geometries of Vortex Generators (VGs) in a high Reynolds number boundary layer. The VGs have been mounted in a cascade producing counter-rotating vortices and the downstream flow...... development was examined. Three VG geometries were investigated: rectangular, triangular and cambered. The various VG geometries tested are seen to produce different impacts on the boundary layer flow. Helical symmetry of the generated vortices is confirmed for all investigated VG geometries in this high...... Reynolds number boundary layer. From the parameters resulting from this analysis, it is observed at the most upstream measurement position that the rectangular and triangular VGs produce vortices of similar size, strength and velocity induction whilst the cambered VGs produce smaller and weaker vortices...

Vortex Generator Induced Flow in a High Re Boundary Layer

DEFF Research Database (Denmark)

Velte, Clara Marika; Braud, C.; Coudert, S.

2012-01-01

Stereoscopic Particle Image Velocimetry measurements have been conducted in cross-planes behind three different geometries of Vortex Generators (VGs) in a high Reynolds number boundary layer. The VGs have been mounted in a cascade producing counter-rotating vortices and the downstream flow...... development was examined. Three VG geometries were investigated: rectangular, triangular and cambered. The various VG geometries tested are seen to produce different impacts on the boundary layer flow. Helical symmetry of the generated vortices is confirmed for all investigated VG geometries in this high...... Reynolds number boundary layer. From the parameters resulting from this analysis, it is observed at the most upstream measurement position that the rectangular and triangular VGs produce vortices of similar size, strength and velocity induction whilst the cambered VGs produce smaller and weaker vortices...

A simple and rapid method for isolation of high quality genomic DNA from fruit trees and conifers using PVP.

Science.gov (United States)

Kim, C S; Lee, C H; Shin, J S; Chung, Y S; Hyung, N I

1997-03-01

Because DNA degradation is mediated by secondary plant products such as phenolic terpenoids, the isolation of high quality DNA from plants containing a high content of polyphenolics has been a difficult problem. We demonstrate an easy extraction process by modifying several existing ones. Using this process we have found it possible to isolate DNAs from four fruit trees, grape (Vitis spp.), apple (Malus spp.), pear (Pyrus spp.) and persimmon (Diospyros spp.) and four species of conifer, Pinus densiflora, Pinus koraiensis,Taxus cuspidata and Juniperus chinensis within a few hours. Compared with the existing method, we have isolated high quality intact DNAs (260/280 = 1.8-2.0) routinely yielding 250-500 ng/microl (total 7.5-15 microg DNA from four to five tissue discs).

Antimicrobial activity of filamentous fungi isolated from highly antibiotic-contaminated river sediment

Science.gov (United States)

Svahn, K. Stefan; Göransson, Ulf; El-Seedi, Hesham; Bohlin, Lars; Larsson, D.G. Joakim; Olsen, Björn; Chryssanthou, Erja

2012-01-01

Background Filamentous fungi are well known for their production of substances with antimicrobial activities, several of which have formed the basis for the development of new clinically important antimicrobial agents. Recently, environments polluted with extraordinarily high levels of antibiotics have been documented, leading to strong selection pressure on local sentinel bacterial communities. In such microbial ecosystems, where multidrug-resistant bacteria are likely to thrive, it is possible that certain fungal antibiotics have become less efficient, thus encouraging alternative strategies for fungi to compete with bacteria. Methods In this study, sediment of a highly antibiotic-contaminated Indian river was sampled in order to investigate the presence of cultivable filamentous fungi and their ability to produce substances with antimicrobial activity. Results Sixty one strains of filamentous fungi, predominantly various Aspergillus spp. were identified. The majority of the Aspergillus strains displayed antimicrobial activity against methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing Escherichia coli, vancomycin-resistant Enterococcus faecalis and Candida albicans. Bioassay-guided isolation of the secondary metabolites of A. fumigatus led to the identification of gliotoxin. Conclusion This study demonstrated proof of principle of using bioassay-guided isolation for finding bioactive molecules. PMID:22957125

Antimicrobial activity of filamentous fungi isolated from highly antibiotic-contaminated river sediment

Directory of Open Access Journals (Sweden)

K. Stefan Svahn

2012-05-01

Full Text Available Background: Filamentous fungi are well known for their production of substances with antimicrobial activities, several of which have formed the basis for the development of new clinically important antimicrobial agents. Recently, environments polluted with extraordinarily high levels of antibiotics have been documented, leading to strong selection pressure on local sentinel bacterial communities. In such microbial ecosystems, where multidrug-resistant bacteria are likely to thrive, it is possible that certain fungal antibiotics have become less efficient, thus encouraging alternative strategies for fungi to compete with bacteria. Methods: In this study, sediment of a highly antibiotic-contaminated Indian river was sampled in order to investigate the presence of cultivable filamentous fungi and their ability to produce substances with antimicrobial activity. Results: Sixty one strains of filamentous fungi, predominantly various Aspergillus spp. were identified. The majority of the Aspergillus strains displayed antimicrobial activity against methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing Escherichia coli, vancomycin-resistant Enterococcus faecalis and Candida albicans. Bioassay-guided isolation of the secondary metabolites of A. fumigatus led to the identification of gliotoxin. Conclusion: This study demonstrated proof of principle of using bioassay-guided isolation for finding bioactive molecules.

High-power and long-pulse operation of TE{sub 31,11} mode gyrotron

Energy Technology Data Exchange (ETDEWEB)

Ikeda, Ryosuke, E-mail: ikeda.ryosuke@jaea.go.jp; Kajiwara, Ken; Oda, Yasuhisa; Takahashi, Koji; Sakamoto, Keishi

2015-10-15

Highlights: • We are under development of TE{sub 31,11} mode gyrotron to aim ITER specification. • HE{sub 11} mode purity reached 96% of ITER specification. • Mode competition was suppressed in initial phase of oscillation by anode voltage control. • Maximum output power of 1.2 MW was achieved. • Steady state operation of 500 MJ was achieved. - Abstract: The ITER electron cyclotron system is designed to inject a 20 MW RF beam by using twenty-four 170 GHz/1 MW gyrotrons. JAEA is currently developing a gyrotron having a high-order mode (TE{sub 31,11}) to reduce the heat load in the cavity resonator and achieve an output power greater than 1 MW. The measured radiation profile at the front of the diamond window agreed with the results of the calculation. In order to suppress RF loss in the equatorial and upper port launchers, a high-quality HE{sub 11} mode is required at the exit of the matching optics unit (MOU). An HE{sub 11} mode purity of 96% was achieved by finely adjusting the two mirrors in the MOU. During the oscillation start-up phase, mode competition with counter-rotating TE{sub 29,12} mode was observed on the higher magnetic field side which caused arcing and pressure increase in the gyrotron. To avoid the counter-rotating TE{sub 29,12} mode from being excited, a start-up scenario that controls the voltage between the anode and cathode electrodes at the initial phase of operation was introduced, which was able to achieve a stable start-up of TE{sub 31,11} mode. A 1.2 MW output power having a total electric efficiency of 43% was obtained in high-power experiments. In steady-state operation, a 1000 s oscillation length and output power of 0.51 MW was achieved.

Robust DNA Isolation and High-throughput Sequencing Library Construction for Herbarium Specimens.

Science.gov (United States)

Saeidi, Saman; McKain, Michael R; Kellogg, Elizabeth A

2018-03-08

Herbaria are an invaluable source of plant material that can be used in a variety of biological studies. The use of herbarium specimens is associated with a number of challenges including sample preservation quality, degraded DNA, and destructive sampling of rare specimens. In order to more effectively use herbarium material in large sequencing projects, a dependable and scalable method of DNA isolation and library preparation is needed. This paper demonstrates a robust, beginning-to-end protocol for DNA isolation and high-throughput library construction from herbarium specimens that does not require modification for individual samples. This protocol is tailored for low quality dried plant material and takes advantage of existing methods by optimizing tissue grinding, modifying library size selection, and introducing an optional reamplification step for low yield libraries. Reamplification of low yield DNA libraries can rescue samples derived from irreplaceable and potentially valuable herbarium specimens, negating the need for additional destructive sampling and without introducing discernible sequencing bias for common phylogenetic applications. The protocol has been tested on hundreds of grass species, but is expected to be adaptable for use in other plant lineages after verification. This protocol can be limited by extremely degraded DNA, where fragments do not exist in the desired size range, and by secondary metabolites present in some plant material that inhibit clean DNA isolation. Overall, this protocol introduces a fast and comprehensive method that allows for DNA isolation and library preparation of 24 samples in less than 13 h, with only 8 h of active hands-on time with minimal modifications.

The population genetics of Pseudomonas aeruginosa isolates from different patient populations exhibits high-level host specificity.

Directory of Open Access Journals (Sweden)

Rosa van Mansfeld

Full Text Available OBJECTIVE: To determine whether highly prevalent P. aeruginosa sequence types (ST in Dutch cystic fibrosis (CF patients are specifically linked to CF patients we investigated the population structure of P. aeruginosa from different clinical backgrounds. We first selected the optimal genotyping method by comparing pulsed-field gel electrophoresis (PFGE, multilocus sequence typing (MLST and multilocus variable number tandem-repeat analysis (MLVA. METHODS: Selected P. aeruginosa isolates (n = 60 were genotyped with PFGE, MLST and MLVA to determine the diversity index (DI and congruence (adjusted Rand and Wallace coefficients. Subsequently, isolates from patients admitted to two different ICUs (n = 205, from CF patients (n = 100 and from non-ICU, non-CF patients (n = 58, of which 19 were community acquired were genotyped with MLVA to determine distribution of genotypes and genetic diversity. RESULTS: Congruence between the typing methods was >79% and DIs were similar and all >0.963. Based on costs, ease, speed and possibilities to compare results between labs an adapted MLVA scheme called MLVA9-Utrecht was selected as the preferred typing method. In 363 clinical isolates 252 different MLVA types (MTs were identified, indicating a highly diverse population (DI  = 0.995; CI  = 0.993-0.997. DI levels were similarly high in the diverse clinical sources (all >0.981 and only eight genotypes were shared. MTs were highly specific (>80% for the different patient populations, even for similar patient groups (ICU patients in two distinct geographic regions, with only three of 142 ICU genotypes detected in both ICUs. The two major CF clones were unique to CF patients. CONCLUSION: The population structure of P. aeruginosa isolates is highly diverse and population specific without evidence for a core lineage in which major CF, hospital or community clones co-cluster. The two genotypes highly prevalent among Dutch CF patients appeared unique to CF patients

Isolation and characterization of a highly evolved type 3 vaccine-derived poliovirus in China.

Science.gov (United States)

Zhang, Xiaowei; Qin, Chong; Li, Wei; Zheng, Zhenhua; Wang, Hanzhong; Cui, Zongqiang

2017-06-15

In this study, we report the identification and characterization of a highly evolved type 3 vaccine-derived poliovirus (VDPV) strain designated as WIV14, isolated in 2014 from a 4-year-old child suspected of having an enteroviral infection in China. Complete genome sequence of WIV14 revealed multiple nucleotide substitutions when compared with the attenuated poliovirus (PV) Sabin 3, including the reversion of three major attenuation sites to wild type. From the nucleotide divergence for the P1/capsid region, we estimated that the evolution time of WIV14 was more than 7 years, indicating the possible long time of replication. WIV14 strain seemed to have differences in biological characteristics compared with attenuated PV strains, such as being non-temperature-sensitive and producing large plaques. The current isolation of a highly divergent type 3 VDPV gives an idea of the risk of emergent VDPV strains, and emphasizes the importance of maintaining high vaccination coverage and herd immunity against PVs in China. Copyright © 2017 Elsevier B.V. All rights reserved.

State Recognition of High Voltage Isolation Switch Based on Background Difference and Iterative Search

Science.gov (United States)

Xu, Jiayuan; Yu, Chengtao; Bo, Bin; Xue, Yu; Xu, Changfu; Chaminda, P. R. Dushantha; Hu, Chengbo; Peng, Kai

2018-03-01

The automatic recognition of the high voltage isolation switch by remote video monitoring is an effective means to ensure the safety of the personnel and the equipment. The existing methods mainly include two ways: improving monitoring accuracy and adopting target detection technology through equipment transformation. Such a method is often applied to specific scenarios, with limited application scope and high cost. To solve this problem, a high voltage isolation switch state recognition method based on background difference and iterative search is proposed in this paper. The initial position of the switch is detected in real time through the background difference method. When the switch starts to open and close, the target tracking algorithm is used to track the motion trajectory of the switch. The opening and closing state of the switch is determined according to the angle variation of the switch tracking point and the center line. The effectiveness of the method is verified by experiments on different switched video frames of switching states. Compared with the traditional methods, this method is more robust and effective.

Dual R3R5 tropism characterizes cerebrospinal fluid HIV-1 isolates from individuals with high cerebrospinal fluid viral load.

Science.gov (United States)

Karlsson, Ulf; Antonsson, Liselotte; Ljungberg, Bengt; Medstrand, Patrik; Esbjörnsson, Joakim; Jansson, Marianne; Gisslen, Magnus

2012-09-10

To study the use of major and alternative coreceptors by HIV-1 isolates obtained from paired plasma and cerebrospinal fluid (CSF) samples. Paired plasma and CSF isolates from HIV-1-infected individuals with varying clinical, virologic, and immunologic parameters were assessed for the ability to infect indicator cells expressing a panel of coreceptors with documented expression in the central nervous system (CNS). HIV-1 isolates obtained from plasma and CSF in 28 individuals with varying viral load, CD4 T-cell counts, and with or without AIDS-defining disease were analyzed for the ability to infect NP2.CD4 cells stably expressing a panel of HIV coreceptors (CCR5, CXCR4, CCR3, CXCR6, GPR1, APJ, ChemR23, RDC-1 or BLT1). All isolates from both plasma and CSF utilized CCR5 and/or CXCR4. However, the ability to use both CCR3 and CCR5 (R3R5) was more pronounced in CSF isolates and correlated with high CSF viral load and low CD4 T-cell count. Notably, four out of five CSF isolates of subtype C origin exhibited CXCR6 use, which coincided with high CSF viral load despite preserved CD4 T-cell counts. The use of other alternative coreceptors was less pronounced. Dual-tropic R3R5 HIV-1 isolates in CSF coincide with high CSF viral load and low CD4 T-cell counts. Frequent CXCR6 use by CSF-derived subtype C isolates indicates that subtype-specific differences in coreceptor use may exist that will not be acknowledged when assessing plasma virus isolates. The findings may also bare relevance for HIV-1 replication within the CNS, and consequently, for the neuropathogenesis of AIDS.

Isolated Systolic Hypertension: A Health Concern?

Science.gov (United States)

Isolated systolic hypertension: A health concern? Is having a high top number (systolic) blood pressure, but a normal bottom number (diastolic) ... mm Hg, you have a common type of high blood pressure called isolated systolic hypertension. Isolated systolic hypertension can ...

Isolation of an H5N8 Highly Pathogenic Avian Influenza Virus Strain from Wild Birds in Seoul, a Highly Urbanized Area in South Korea.

Science.gov (United States)

Kwon, Jung-Hoon; Lee, Dong-Hun; Jeong, Jei-Hyun; Yuk, Seong-Su; Erdene-Ochir, Tseren-Ochir; Noh, Jin-Yong; Hong, Woo-Tack; Jeong, Sol; Gwon, Gyeong-Bin; Lee, Sang-Won; Choi, In-Soo; Song, Chang-Seon

2017-07-01

Asian-lineage H5 highly pathogenic avian influenza viruses (HPAIV) have caused recurrent outbreaks in poultry and wild birds. In January 2014, H5N8 HPAIV caused outbreaks in South Korea and subsequently spread to East Asia, Europe, and North America. We report the isolation of an H5N8 HPAIV strain from wild birds in Seoul, the most-developed city in South Korea. We analyzed the complete genome sequence of this isolate and estimated its origin using a phylogenetic analysis. The Seoul H5N8 isolate clustered phylogenetically with strains isolated from migratory wild birds but was distinct from Korean poultry isolates. This H5N8 virus was likely introduced into the urbanized city by migratory wild birds. Therefore, wild bird habitats in urbanized areas should be carefully monitored for HPAIV.

Identification of protoplast-isolation responsive microRNAs in Citrus reticulata Blanco by high-throughput sequencing.

Science.gov (United States)

Xu, Xiaoyong; Xu, Xiaoling; Zhou, Yipeng; Zeng, Shaohua; Kong, Weiwen

2017-01-01

Protoplast isolation is a stress-inducing process, during which a variety of physiological and molecular alterations take place. Such stress response affects the expression of totipotency of cultured protoplasts. MicroRNAs (miRNAs) play important roles in plant growth, development and stress responses. However, the underlying mechanism of miRNAs involved in the protoplast totipotency remains unclear. In this study, high-throughput sequencing technology was used to sequence two populations of small RNA from calli and callus-derived protoplasts in Citrus reticulata Blanco. A total of 67 known miRNAs from 35 families and 277 novel miRNAs were identified. Among these miRNAs, 18 known miRNAs and 64 novel miRNAs were identified by differentially expressed miRNAs (DEMs) analysis. The expression patterns of the eight DEMs were verified by qRT-PCR. Target prediction showed most targets of the miRNAs were transcription factors. The expression levels of half targets showed a negative correlation to those of the miRNAs. Furthermore, the physiological analysis showed high levels of antioxidant activities in isolated protoplasts. In short, our results indicated that miRNAs may play important roles in protoplast-isolation response.

Identification of Brucella spp. isolated from human brucellosis in Malaysia using high-resolution melt (HRM) analysis.

Science.gov (United States)

Mohamed Zahidi, Jama'ayah; Bee Yong, Tay; Hashim, Rohaidah; Mohd Noor, Azura; Hamzah, Siti Hawa; Ahmad, Norazah

2015-04-01

Molecular approaches have been investigated to overcome difficulties in identification and differentiation of Brucella spp. using conventional phenotypic methods. In this study, high-resolution melt (HRM) analysis was used for rapid identification and differentiation of members of Brucella genus. A total of 41 Brucella spp. isolates from human brucellosis were subjected to HRM analysis using 4 sets of primers, which identified 40 isolates as Brucella melitensis and 1 as Brucella canis. The technique utilized low DNA concentration and was highly reproducible. The assay is shown to be a useful diagnostic tool, which can rapidly differentiate Brucella up to species level. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

A Multifunctional Isolated and Non-Isolated Dual Mode Converter for Renewable Energy Conversion Applications

Directory of Open Access Journals (Sweden)

Yiwang Wang

2017-11-01

Full Text Available In this paper, a multifunctional isolated and non-isolated dual-mode low-power converter was designed for renewable energy conversion applications such as photovoltaic power generation to achieve different operating modes under bi-directional electrical conversion. The proposed topology consists of a bidirectional non-isolated DC/DC circuit and an isolated converter with a high-frequency transformer, which merge the advantages of both the conventional isolated converter and non-isolated converter with the combination of the two converter technologies. Compared with traditional converters, the multifunctional converter can not only realize conventional bi-directional functions, but can also be applied for many different operation modes and meet the high output/input ratio demands with the two converter circuits operating together. A novel control algorithm was proposed to achieve the various functions of the proposed converter. An experimental platform based on the proposed circuit was established. Both the simulation and experimental results indicated that the proposed converter could provide isolated and non-isolated modes in different applications, which could meet different practical engineering requirements.

Hydrodistillation-adsorption method for the isolation of water-soluble, non-soluble and high volatile compounds from plant materials.

Science.gov (United States)

Mastelić, J; Jerković, I; Blazević, I; Radonić, A; Krstulović, L

2008-08-15

Proposed method of hydrodistillation-adsorption (HDA) on activated carbon and hydrodistillation (HD) with solvent trap were compared for the isolation of water-soluble, non-soluble and high volatile compounds, such as acids, monoterpenes, isothiocyanates and others from carob (Certonia siliqua L.), rosemary (Rosmarinus officinalis L.) and rocket (Eruca sativa L.). Isolated volatiles were analyzed by GC and GC/MS. The main advantages of HDA method over ubiquitous HD method were higher yields of volatile compounds and their simultaneous separation in three fractions that enabled more detail analyses. This method is particularly suitable for the isolation and analysis of the plant volatiles with high amounts of water-soluble compounds. In distinction from previously published adsorption of remaining volatile compounds from distillation water on activated carbon, this method offers simultaneous hydrodistillation and adsorption in the same apparatus.

High resistance rate against 15 different antibiotics in aerobic gram-negative bacteria isolates of cardiology intensive care unit patients

Directory of Open Access Journals (Sweden)

Küçükates E

2002-01-01

Full Text Available Aerobic gram negative bacteria were isolated and examined microbiologically from various clinical samples of 602 patients hospitalized between January 1997 and December 2000 in surgical and coronary intensive care units (ICUs. A total of 827 isolates were obtained from 602 patients. The majority of microorganisms were isolated from the respiratory tract (50.3% and blood (39.9%. Pseudomonas spp. were the most frequently isolated gram negative species (32.7%, followed by Acinetobacter spp. (24.0% and Klebsiella pneumoniae (19.4%. High resistance rates to all antibiotics studied were observed. Imipenem and meropenem were the most effective antibiotics against gram negatives.

Dynamic isolation technologies in negative pressure isolation wards

CERN Document Server

Xu, Zhonglin

2017-01-01

This book presents novel design principles and technologies for dynamic isolation based on experimental studies. These approaches have now become the local standard in Beijing and are currently being promoted for use nationwide. Further, the book provides details of measures and guidelines for the design process. Departing from the traditional understanding that isolation wards should be designed with high negative pressure, airtight doors and fresh air, it establishes the basis for designing biological clean rooms, including isolation wards, using a simple and convenient scientific approach. This book is intended for designers, engineers, researchers, hospital management staff and graduate students in heating ventilation air conditioning (HVAC), air cleaning technologies and related areas.

High terbinafine resistance in Trichophyton interdigitale isolates in Delhi, India harbouring mutations in the squalene epoxidase gene.

Science.gov (United States)

Singh, Ashutosh; Masih, Aradhana; Khurana, Ananta; Singh, Pradeep Kumar; Gupta, Meenakshi; Hagen, Ferry; Meis, Jacques F; Chowdhary, Anuradha

2018-03-25

In the last few years, infections caused by dermatophytes along with a concomitant increase in the number of difficult to treat cases have increasingly been recognised, indicating that dermatophytosis remains a challenging public health problem. The majority of infections are caused by Trichophyton rubrum and Trichophyton mentagrophytes complex. Terbinafine, an allylamine antifungal used orally and topically is considered to be a first-line drug in the therapy of dermatophyte infections. Terbinafine resistance has been predominately attributed to point mutations in the squalene epoxidase (SQLE) target gene a key enzyme in the ergosterol biosynthetic pathway leading to single amino acid substitutions. Here, we report the largest series of 20 terbinafine-resistant Trichophyton interdigitale isolates obtained predominately from cases of tinea corporis/cruris in three hospitals in Delhi, India exhibiting elevated MICs (4 to ≥32 μg/mL) to terbinafine and all harbouring single-point mutations Leu393Phe or Phe397Leu in the SQLE gene. In 12 (60%) T. interdigitale isolates, the Phe397Leu substitution was observed, whereas in the remaining 8 (40%) isolates the substitution Leu393Phe was reported for the first time in T. interdigitale. Furthermore, 10 susceptible T. interdigitale isolates (0.125-2 μg/mL) had a wild-type genotype. Remarkably, considerably high terbinafine resistance rate of 32% was observed among 63 T. interdigitale isolates identified by sequencing of the internal transcribed spacer region. This high level of terbinafine resistance of Indian dermatophyte isolates is worrisome warranting antifungal susceptibility testing and mutation analysis for monitoring this emerging resistance. © 2018 Blackwell Verlag GmbH.

High Throughput Microplate Respiratory Measurements Using Minimal Quantities Of Isolated Mitochondria

Science.gov (United States)

Rogers, George W.; Brand, Martin D.; Petrosyan, Susanna; Ashok, Deepthi; Elorza, Alvaro A.; Ferrick, David A.; Murphy, Anne N.

2011-01-01

Recently developed technologies have enabled multi-well measurement of O2 consumption, facilitating the rate of mitochondrial research, particularly regarding the mechanism of action of drugs and proteins that modulate metabolism. Among these technologies, the Seahorse XF24 Analyzer was designed for use with intact cells attached in a monolayer to a multi-well tissue culture plate. In order to have a high throughput assay system in which both energy demand and substrate availability can be tightly controlled, we have developed a protocol to expand the application of the XF24 Analyzer to include isolated mitochondria. Acquisition of optimal rates requires assay conditions that are unexpectedly distinct from those of conventional polarography. The optimized conditions, derived from experiments with isolated mouse liver mitochondria, allow multi-well assessment of rates of respiration and proton production by mitochondria attached to the bottom of the XF assay plate, and require extremely small quantities of material (1–10 µg of mitochondrial protein per well). Sequential measurement of basal, State 3, State 4, and uncoupler-stimulated respiration can be made in each well through additions of reagents from the injection ports. We describe optimization and validation of this technique using isolated mouse liver and rat heart mitochondria, and apply the approach to discover that inclusion of phosphatase inhibitors in the preparation of the heart mitochondria results in a specific decrease in rates of Complex I-dependent respiration. We believe this new technique will be particularly useful for drug screening and for generating previously unobtainable respiratory data on small mitochondrial samples. PMID:21799747

High throughput microplate respiratory measurements using minimal quantities of isolated mitochondria.

Directory of Open Access Journals (Sweden)

George W Rogers

Full Text Available Recently developed technologies have enabled multi-well measurement of O(2 consumption, facilitating the rate of mitochondrial research, particularly regarding the mechanism of action of drugs and proteins that modulate metabolism. Among these technologies, the Seahorse XF24 Analyzer was designed for use with intact cells attached in a monolayer to a multi-well tissue culture plate. In order to have a high throughput assay system in which both energy demand and substrate availability can be tightly controlled, we have developed a protocol to expand the application of the XF24 Analyzer to include isolated mitochondria. Acquisition of optimal rates requires assay conditions that are unexpectedly distinct from those of conventional polarography. The optimized conditions, derived from experiments with isolated mouse liver mitochondria, allow multi-well assessment of rates of respiration and proton production by mitochondria attached to the bottom of the XF assay plate, and require extremely small quantities of material (1-10 µg of mitochondrial protein per well. Sequential measurement of basal, State 3, State 4, and uncoupler-stimulated respiration can be made in each well through additions of reagents from the injection ports. We describe optimization and validation of this technique using isolated mouse liver and rat heart mitochondria, and apply the approach to discover that inclusion of phosphatase inhibitors in the preparation of the heart mitochondria results in a specific decrease in rates of Complex I-dependent respiration. We believe this new technique will be particularly useful for drug screening and for generating previously unobtainable respiratory data on small mitochondrial samples.

Classification of large circulating tumor cells isolated with ultra-high throughput microfluidic Vortex technology

Science.gov (United States)

Che, James; Yu, Victor; Dhar, Manjima; Renier, Corinne; Matsumoto, Melissa; Heirich, Kyra; Garon, Edward B.; Goldman, Jonathan; Rao, Jianyu; Sledge, George W.; Pegram, Mark D.; Sheth, Shruti; Jeffrey, Stefanie S.; Kulkarni, Rajan P.; Sollier, Elodie; Di Carlo, Dino

2016-01-01

Circulating tumor cells (CTCs) are emerging as rare but clinically significant non-invasive cellular biomarkers for cancer patient prognosis, treatment selection, and treatment monitoring. Current CTC isolation approaches, such as immunoaffinity, filtration, or size-based techniques, are often limited by throughput, purity, large output volumes, or inability to obtain viable cells for downstream analysis. For all technologies, traditional immunofluorescent staining alone has been employed to distinguish and confirm the presence of isolated CTCs among contaminating blood cells, although cells isolated by size may express vastly different phenotypes. Consequently, CTC definitions have been non-trivial, researcher-dependent, and evolving. Here we describe a complete set of objective criteria, leveraging well-established cytomorphological features of malignancy, by which we identify large CTCs. We apply the criteria to CTCs enriched from stage IV lung and breast cancer patient blood samples using the High Throughput Vortex Chip (Vortex HT), an improved microfluidic technology for the label-free, size-based enrichment and concentration of rare cells. We achieve improved capture efficiency (up to 83%), high speed of processing (8 mL/min of 10x diluted blood, or 800 μL/min of whole blood), and high purity (avg. background of 28.8±23.6 white blood cells per mL of whole blood). We show markedly improved performance of CTC capture (84% positive test rate) in comparison to previous Vortex designs and the current FDA-approved gold standard CellSearch assay. The results demonstrate the ability to quickly collect viable and pure populations of abnormal large circulating cells unbiased by molecular characteristics, which helps uncover further heterogeneity in these cells. PMID:26863573

Determination of optimum shape and dimensions of anode high-voltage isolators for gaseous proportional counters

International Nuclear Information System (INIS)

Jelen, K.; Jagusztyn, W.

1975-01-01

The influence of the shape and dimensions of the high-voltage anode-to-cathods isolator on the regularity of the electrostatic field distribution along the anode of a cylindrical gaseous proportional counter is studied. For a counter of fixed dimensions, the length and diameter of the glass isolators were optimized to disrupt as little as possible the regularity of the field distribution in the active volume of the counter. Results of calculations are in agreement with experimental data. The obtained results provide a basis for obtaining a correct ratio of the active volume of the counter to its total volume. (author)

Yeast Isolation for Bioethanol Production

Directory of Open Access Journals (Sweden)

EKA RURIANI

2012-09-01

Full Text Available We have isolated 12 yeast isolates from five different rotten fruits by using a yeast glucose chloramphenicol agar (YGCA medium supplemented with tetracycline. From pre-screening assay, four isolates exhibited higher substrate (glucose-xylose consumption efficiency in the reaction tube fermentation compared to Saccharomyces cerevisiae dan Saccharomyces ellipsoids as the reference strains. Based on the fermentation process in gooseneck flasks, we observed that two isolates (K and SB showed high fermentation efficiency both in sole glucose and mixed glucose-xylose substrate. Moreover, isolates K and SB produced relatively identical level of ethanol concentration compared to the reference strains. Isolates H and MP could only produce high levels of ethanol in glucose fermentation, while only half of that amount of ethanol was detected in glucose-xylose fermentation. Isolate K and SB were identified as Pichia kudriavzeevii (100% based on large sub unit (LSU ribosomal DNA D1/D2 region.

Transport and acceleration of the high-current ion beam in magneto-isolated gap

International Nuclear Information System (INIS)

Karas', V.I.; Kornilov, E.A.; Manuilenko, O.V.; Fedorovskaya, O.V.; Tarakanov, V.P.

2015-01-01

The possibility of transportation and acceleration of the high-current ion beam in the magneto-isolated gap has been demonstrated. Found the parameters of the system and beams (the magnetic field produced by the coils with opposing currents, the size of the system, and the parameters of the beams), under which the uniform acceleration of the high-current ion beam all along the gap length is realized. It is shown that the quality of the ion beam, during transport and acceleration, at the exit of the gap is acceptable for many technological applications.

High prevalence of methicillin-resistant coagulase-negative staphylococci isolated from a university environment in Thailand.

Science.gov (United States)

Seng, Rathanin; Leungtongkam, Udomluk; Thummeepak, Rapee; Chatdumrong, Wassana; Sitthisak, Sutthirat

2017-06-01

The present study was conducted to isolate and characterize the molecular epidemiology of the methicillin-resistant staphylococci in the general university environment, where all five locations; the library, restrooms, canteens, computer rooms and outdoor surfaces, are in common use by a large population of students. We used Mannitol Salt Agar (MSA) supplemented with 4 μg/ml of oxacillin to screen the methicillin-resistant staphylococci. The species level was identified by PCR of rdr (Staphylococcus epidermidis), groESL (Staphylococcus haemolyticus) and nuc (Staphylococcus aureus and Staphylococcus warneri) genes and DNA sequencing of tuf and dnaJ genes. The susceptibility patterns of the isolates were determined using the disk diffusion method. Antibiotic and disinfectant resistance genes, together with SCCmec types, were detected by the PCR method. The methicillin resistant-staphylococci were isolated from 41 of 200 samples (20.5%), and all of them were found to be methicillin-resistant coagulase negative staphylococci (MR-CoNS). The library had the highest percentage of contamination, with 43.3% of the samples found to be contaminated. All isolates belonged to 6 different species including S. haemolyticus, S. epidermidis, S. warneri, S. cohnii, S. saprophyticus and S. hominis. The antimicrobial resistance rates were highest against penicillin (100%), then cefoxitin (73.1%), erythromycin (73.1%) and oxacillin (68.3%). Altogether, the isolates were approximately 61.0% multidrug resistant (MDR), with the S. epidermidis isolates being the most multidrug resistant. The prevalence of the qacA/B gene was detected in 63.4% of the isolates, and SCCmec could be typed in 43.9% (18/41) of the isolates. The type range was: II (n = 1), IVd (n = 1), I (n = 2), V (n = 6), IVa (n = 8) and untypeable (n = 23). This result indicates that these university environments are contaminated with methicillin-resistant coagulase negative staphylococci that carry various SCCmec types and

Vibration isolation and damping in high precision equipment

Science.gov (United States)

Bukkems, B.; Ruijl, T.; Simons, J.

2017-06-01

All systems located in a laboratory environment or factory are subject to disturbances. These disturbances can either come from the surroundings, e.g. floor-induced vibrations, or from the system itself, e.g. stage-induced vibrations. In many cases it is needed to minimize the effect of these disturbances. This can either be done by isolating the system from its disturbance source or by applying damping to the system. In this paper we present various cases in which we have effectively reduced the impact of disturbances on the system's performance, either by improving its isolation system, by minimizing the impact of stage reaction forces, or by designing polymer damping into the system.

Fault detection and isolation of high temperature proton exchange membrane fuel cell stack under the influence of degradation

DEFF Research Database (Denmark)

Jeppesen, Christian; Araya, Samuel Simon; Sahlin, Simon Lennart

2017-01-01

This study proposes a data-drive impedance-based methodology for fault detection and isolation of low and high cathode stoichiometry, high CO concentration in the anode gas, high methanol vapour concentrations in the anode gas and low anode stoichiometry, for high temperature PEM fuel cells....... The fault detection and isolation algorithm is based on an artificial neural network classifier, which uses three extracted features as input. Two of the proposed features are based on angles in the impedance spectrum, and are therefore relative to specific points, and shown to be independent of degradation......, contrary to other available feature extraction methods in the literature. The experimental data is based on a 35 day experiment, where 2010 unique electrochemical impedance spectroscopy measurements were recorded. The test of the algorithm resulted in a good detectability of the faults, except for high...

High prevalence of biofilm synergy among bacterial soil isolates in cocultures indicates bacterial interspecific cooperation

DEFF Research Database (Denmark)

Ren, Dawei; Madsen, Jonas Stenløkke; Sørensen, Søren Johannes

2015-01-01

of single-species biofilms, indicating that all the individual strains benefit from inclusion in the multispecies community. Our results show a high prevalence of synergy in biofilm formation in multispecies consortia isolated from a natural bacterial habitat and suggest that interspecific cooperation...

Physics in isolation

International Nuclear Information System (INIS)

Anon.

1986-01-01

In late May, about 330 physicists made their way up to isolated and beautiful Lake Louise high in the Canadian Rockies about 100 miles west of Calgary in a second effort to increase interactions between particle and nuclear physicists. The conference series aims to foster exciting and diverse physics by bringing the different physicists together somewhere which is so isolated that they must interact with each other. The formula worked very well and isolated Lake Louise was a huge success

Physics in isolation

Energy Technology Data Exchange (ETDEWEB)

Anon.

1986-09-15

In late May, about 330 physicists made their way up to isolated and beautiful Lake Louise high in the Canadian Rockies about 100 miles west of Calgary in a second effort to increase interactions between particle and nuclear physicists. The conference series aims to foster exciting and diverse physics by bringing the different physicists together somewhere which is so isolated that they must interact with each other. The formula worked very well and isolated Lake Louise was a huge success.

Comparative Evaluation of Three-Phase Isolated Matrix-Type PFC Rectifier Concepts for High Efficiency 380VDC Supplies of Future Telco and Data Centers

DEFF Research Database (Denmark)

Cortes, Patricio; Bortis, Dominik; Pittini, Riccardo

2014-01-01

rectifier and in many cases a mains transformer is used to provide galvanic isolation. In order to achieve a high efficiency in the DC voltage generation and to implement the required isolation, a single-stage concept, such as a matrix-type rectifier that enables PFC functionality and galvanic isolation...... in a single conversion, can be beneficial. In addition, due to the fact that with the matrix-type rectifier the galvanic isolation is performed with a high-frequency transformer, this results in a more compact rectifier system compared to conventional systems where the mains-frequency isolation transformer...... is located at the input of the PFC rectifier. In this paper, an overview of isolated matrix-type PFC rectifier topologies is given and a new converter circuit is proposed, analyzed and comparatively evaluated against another promising PFC rectifier concept, the phase-modular IMY-rectifier....

High incidence of recurrent copy number variants in patients with isolated and syndromic Müllerian aplasia.

Science.gov (United States)

Nik-Zainal, Serena; Strick, Reiner; Storer, Mekayla; Huang, Ni; Rad, Roland; Willatt, Lionel; Fitzgerald, Tomas; Martin, Vicki; Sandford, Richard; Carter, Nigel P; Janecke, Andreas R; Renner, Stefan P; Oppelt, Patricia G; Oppelt, Peter; Schulze, Christine; Brucker, Sara; Hurles, Matthew; Beckmann, Matthias W; Strissel, Pamela L; Shaw-Smith, Charles

2011-03-01

Congenital malformations involving the Müllerian ducts are observed in around 5% of infertile women. Complete aplasia of the uterus, cervix, and upper vagina, also termed Müllerian aplasia or Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome, occurs with an incidence of around 1 in 4500 female births, and occurs in both isolated and syndromic forms. Previous reports have suggested that a proportion of cases, especially syndromic cases, are caused by variation in copy number at different genomic loci. In order to obtain an overview of the contribution of copy number variation to both isolated and syndromic forms of Müllerian aplasia, copy number assays were performed in a series of 63 cases, of which 25 were syndromic and 38 isolated. A high incidence (9/63, 14%) of recurrent copy number variants in this cohort is reported here. These comprised four cases of microdeletion at 16p11.2, an autism susceptibility locus not previously associated with Müllerian aplasia, four cases of microdeletion at 17q12, and one case of a distal 22q11.2 microdeletion. Microdeletions at 16p11.2 and 17q12 were found in 4/38 (10.5%) cases with isolated Müllerian aplasia, and at 16p11.2, 17q12 and 22q11.2 (distal) in 5/25 cases (20%) with syndromic Müllerian aplasia. The finding of microdeletion at 16p11.2 in 2/38 (5%) of isolated and 2/25 (8%) of syndromic cases suggests a significant contribution of this copy number variant alone to the pathogenesis of Müllerian aplasia. Overall, the high incidence of recurrent copy number variants in all forms of Müllerian aplasia has implications for the understanding of the aetiopathogenesis of the condition, and for genetic counselling in families affected by it.

UV light-induced survival response in a highly radiation-resistant isolate of the Moraxella-acinetobacter group

International Nuclear Information System (INIS)

Keller, L.C.; Thompson, T.L.; Maxcy, R.B.

1982-01-01

A highly radiation-resistant member of the Moraxella-Acinetobacter group, isolate 4, obtained from meat, was studied to determine the effect of preexposure to UV radiation on subsequent UV light resistance. Cultures that were preexposed to UV light and incubated for a short time in plate count broth exhibited increased survival of a UV light challenge dose. This response was inhibited in the presence of chloramphenicol. Frequencies of mutation to streptomycin, trimethoprim, and sulfanilamide resistance remained the same after the induction of this survival response and were not altered by treatment with mutagens, with the exception of mutation to streptomycin resistance after γ-irradiation or nitrosoguanidine or methyl methane sulfonate treatment. The results indicated that isolate 4 has a UV light-inducible UV light resistance mechanism which is not associated with increased mutagenesis. The characteristics of the radiation resistance response in this organism are similar to those of certain other common food contaminants. Therefore, considered as part of the total microflora of meat, isolate 4 and the other radiation-resistant Moraxella-Acinetobacter isolates should not pose unique problems in a proposed radappertizaton process

Isolation of Anti-Ricin Protective Antibodies Exhibiting High Affinity from Immunized Non-Human Primates

Directory of Open Access Journals (Sweden)

Tal Noy-Porat

2016-03-01

Full Text Available Ricin, derived from the castor bean plant Ricinus communis, is one of the most potent and lethal toxins known, against which there is no available antidote. To date, the use of neutralizing antibodies is the most promising post-exposure treatment for ricin intoxication. The aim of this study was to isolate high affinity anti-ricin antibodies that possess potent toxin-neutralization capabilities. Two non-human primates were immunized with either a ricin-holotoxin- or subunit-based vaccine, to ensure the elicitation of diverse high affinity antibodies. By using a comprehensive set of primers, immune scFv phage-displayed libraries were constructed and panned. A panel of 10 antibodies (five directed against the A subunit of ricin and five against the B subunit was isolated and reformatted into a full-length chimeric IgG. All of these antibodies were found to neutralize ricin in vitro, and several conferred full protection to ricin-intoxicated mice when given six hours after exposure. Six antibodies were found to possess exceptionally high affinity toward the toxin, with KD values below pM (koff < 1 × 10−7 s−1 that were well correlated with their ability to neutralize ricin. These antibodies, alone or in combination, could be used for the development of a highly-effective therapeutic preparation for post-exposure treatment of ricin intoxication.

High-frequency rugose exopolysaccharide production by Vibrio cholerae strains isolated in Haiti.

Directory of Open Access Journals (Sweden)

Mustafizur Rahman

Full Text Available In October, 2010, epidemic cholera was reported for the first time in Haiti in over 100 years. Establishment of cholera endemicity in Haiti will be dependent in large part on the continued presence of toxigenic V. cholerae O1 in aquatic reservoirs. The rugose phenotype of V. cholerae, characterized by exopolysaccharide production that confers resistance to environmental stress, is a potential contributor to environmental persistence. Using a microbiologic medium promoting high-frequency conversion of smooth to rugose (S-R phenotype, 80 (46.5% of 172 V. cholerae strains isolated from clinical and environmental sources in Haiti were able to convert to a rugose phenotype. Toxigenic V. cholerae O1 strains isolated at the beginning of the epidemic (2010 were significantly less likely to shift to a rugose phenotype than clinical strains isolated in 2012/2013, or environmental strains. Frequency of rugose conversion was influenced by incubation temperature and time. Appearance of the biofilm produced by a Haitian clinical rugose strain (altered biotype El Tor HC16R differed from that of a typical El Tor rugose strain (N16961R by confocal microscopy. On whole-genome SNP analysis, there was no phylogenetic clustering of strains showing an ability to shift to a rugose phenotype. Our data confirm the ability of Haitian clinical (and environmental strains to shift to a protective rugose phenotype, and suggest that factors such as temperature influence the frequency of transition to this phenotype.

High-temperature ethanol production using thermotolerant yeast newly isolated from Greater Mekong Subregion

Directory of Open Access Journals (Sweden)

Atiya Techaparin

Full Text Available Abstract The application of high-potential thermotolerant yeasts is a key factor for successful ethanol production at high temperatures. Two hundred and thirty-four yeast isolates from Greater Mekong Subregion (GMS countries, i.e., Thailand, The Lao People's Democratic Republic (Lao PDR and Vietnam were obtained. Five thermotolerant yeasts, designated Saccharomyces cerevisiae KKU-VN8, KKU-VN20, and KKU-VN27, Pichia kudriavzevii KKU-TH33 and P. kudriavzevii KKU-TH43, demonstrated high temperature and ethanol tolerance levels up to 45 °C and 13% (v/v, respectively. All five strains produced higher ethanol concentrations and exhibited greater productivities and yields than the industrial strain S. cerevisiae TISTR5606 during high-temperature fermentation at 40 °C and 43 °C. S. cerevisiae KKU-VN8 demonstrated the best performance for ethanol production from glucose at 37 °C with an ethanol concentration of 72.69 g/L, a productivity of 1.59 g/L/h and a theoretical ethanol yield of 86.27%. The optimal conditions for ethanol production of S. cerevisiae KKU-VN8 from sweet sorghum juice (SSJ at 40 °C were achieved using the Box-Behnken experimental design (BBD. The maximal ethanol concentration obtained during fermentation was 89.32 g/L, with a productivity of 2.48 g/L/h and a theoretical ethanol yield of 96.32%. Thus, the newly isolated thermotolerant S. cerevisiae KKU-VN8 exhibits a great potential for commercial-scale ethanol production in the future.

Numerical study of internal flow in twin screw extruder and its mixing performance analysis

International Nuclear Information System (INIS)

Kim, Nak Soo; Kim, Hong Bum; Lee, Jae Wook

2006-01-01

We analyzed the non-Newtonian and non-isothermal flow in the melt conveying zone in co-rotating and counter-rotating screw extruder system with the commercial code, STAR-CD, and compared the mixing performance with respect to screw speed and rotating direction. The viscosity of fluid was described by power-law model. The dynamics of mixing was studied numerically by tracking the motion of particles in a twin screw extruder system. The extent of mixing was characterized in terms of the residence time distribution and average strain. The results showed that high screw speed decreases the residence time but increases the shear rate. Therefore higher screw speed increases the strain and has better mixing performance. Counter-rotating screw extruder system and co-rotating screw extruder has the similar shear rate with the same screw speed in spite of different rotating direction. However, the counter-rotating screw has good mixing performance, which is resulted from longer residence time than that of co-rotating screw extruder

High similarity between isolates of pepino mosaic virus suggests a common origin

NARCIS (Netherlands)

Verhoeven, J.Th.J.; Vlugt, van der R.A.A.; Roenhorst, J.W.

2003-01-01

The almost simultaneous outbreaks of Pepino mosaic virus in tomato crops in different European and non-European countries, was reason to have a closer look at the relationship between these isolates and the original isolate from pepino. Fifteen isolates from tomato from different locations and the

Bacteria isolated from pristine high altitude environments in the Argentinean Andean wetlands: plasmid profile and multiple antibiotic resistance

International Nuclear Information System (INIS)

Dib, J.R.; Martinez, M.A.; Sineriz, F.; Farias, M.E.

2005-01-01

Full text: Andean wetlands, placed in the North-Western Argentine at 4,600 m altitude, are attractive for both, environmental and biotechnology studies. Most of these wetlands are completely remote and inaccessible, having a high salinity and metal contents, a wide range of daily temperature changes, and an important intensity of solar UV-B radiation. Bacteria isolated from these environments were identified by 16SrDNA sequence and resulted in Gram-positive colored bacteria. Interesting features, to our knowledge never reported so far from bacteria isolates from these pristine high altitude lake-environments, such as similar plasmids profiles and multiple antibiotic resistances are the focus of this work. At least two plasmids were found in all isolates studied by using modifications of the alkaline Iysis method. Their preliminary characterization in this work includes size, incompatibility group through PCR, genetic transference to suitable hosts by transformation and conjugation, and studies of possible relationships of them with antibiotic resistances. (author)

The spa typing of methicillin-resistant Staphylococcus aureus isolates by High Resolution Melting (HRM) analysis.

Science.gov (United States)

Fasihi, Yasser; Fooladi, Saba; Mohammadi, Mohammad Ali; Emaneini, Mohammad; Kalantar-Neyestanaki, Davood

2017-09-06

Molecular typing is an important tool for control and prevention of infection. A suitable molecular typing method for epidemiological investigation must be easy to perform, highly reproducible, inexpensive, rapid and easy to interpret. In this study, two molecular typing methods including the conventional PCR-sequencing method and high resolution melting (HRM) analysis were used for staphylococcal protein A (spa) typing of 30 Methicillin-resistant Staphylococcus aureus (MRSA) isolates recovered from clinical samples. Based on PCR-sequencing method results, 16 different spa types were identified among the 30 MRSA isolates. Among the 16 different spa types, 14 spa types separated by HRM method. Two spa types including t4718 and t2894 were not separated from each other. According to our results, spa typing based on HRM analysis method is very rapid, easy to perform and cost-effective, but this method must be standardized for different regions, spa types, and real-time machinery.

Isolation and Pharmacological Evaluation of Minor Cannabinoids from High-Potency Cannabis sativa.

Science.gov (United States)

Radwan, Mohamed M; ElSohly, Mahmoud A; El-Alfy, Abir T; Ahmed, Safwat A; Slade, Desmond; Husni, Afeef S; Manly, Susan P; Wilson, Lisa; Seale, Suzanne; Cutler, Stephen J; Ross, Samir A

2015-06-26

Seven new naturally occurring hydroxylated cannabinoids (1-7), along with the known cannabiripsol (8), have been isolated from the aerial parts of high-potency Cannabis sativa. The structures of the new compounds were determined by 1D and 2D NMR spectroscopic analysis, GC-MS, and HRESIMS as 8α-hydroxy-Δ(9)-tetrahydrocannabinol (1), 8β-hydroxy-Δ(9)-tetrahydrocannabinol (2), 10α-hydroxy-Δ(8)-tetrahydrocannabinol (3), 10β-hydroxy-Δ(8)-tetrahydrocannabinol (4), 10α-hydroxy-Δ(9,11)-hexahydrocannabinol (5), 9β,10β-epoxyhexahydrocannabinol (6), and 11-acetoxy-Δ(9)-tetrahydrocannabinolic acid A (7). The binding affinity of isolated compounds 1-8, Δ(9)-tetrahydrocannabinol, and Δ(8)-tetrahydrocannabinol toward CB1 and CB2 receptors as well as their behavioral effects in a mouse tetrad assay were studied. The results indicated that compound 3, with the highest affinity to the CB1 receptors, exerted the most potent cannabimimetic-like actions in the tetrad assay, while compound 4 showed partial cannabimimetic actions. Compound 2, on the other hand, displayed a dose-dependent hypolocomotive effect only.

Broadband Millimeter-Wave In-Phase and Out-of-Phase Waveguide Dividers with High Isolation

Science.gov (United States)

Dong, Jun; Liu, Yu; Yang, Ziqiang; Peng, Hao; Yang, Tao

2015-11-01

In this paper, two novel broadband in-phase and out-of-phase waveguide power dividers with high isolation are presented. Based on the substrate-integrated waveguide (SIW) divider and SIW-to-waveguide transition circuit, two kinds of E-plane waveguide dividers have been implemented. Due to the features of in-phase and out-of-phase performances, the proposed waveguide dividers can provide much more flexibilities than that of conventional E-plane waveguide T-junction. A broadband phase and amplitude performances are achieved across the whole Ka-band owing to the wideband characteristic of the SIW divider and transition circuits. To minimize the size and loss of the divider, a compact and low-loss SIW-to-waveguide transition circuit has been developed using the antisymmetric tapered probes. Two prototypes of the Ka-band waveguide dividers, including the in-phase and out-of-phase types, have been fabricated and measured. Measured results show that the isolation, input return loss, output return loss, amplitude imbalance, and phase imbalance of the in-phase divider are better than 15.5, 13.1, 10.8, 0.4 dB, and 3.50, while those of the out-of-phase divider are better than 15.0, 13.4, 10.4, 0.5 dB, and 3.60, respectively, over the frequency range from 26.5 to 40 GHz. The measured results agree well with the simulated ones. Considering their wide bandwidth, high isolation, good port matching performance, and compact configuration, the two types of waveguide dividers can be good candidates for broadband applications in millimeter-wave waveguide systems.

Isolation and Purification of Oridonin from the Whole Plant of Isodon rubescens by High-Speed Counter-Current Chromatography

Directory of Open Access Journals (Sweden)

ChunYue Yu

2011-09-01

Full Text Available Semi-preparative high-speed counter-current chromatography (HSCCC was successfully used for isolation and purification of oridonin from Isodon rubescens by using a two-phase-solvent system composed of n-hexane-ethyl acetate-methanol-water (2.8:5:2.8:5, v/v/v/v. The targeted compound isolated, collected and purified by HSCCC was analyzed by high performance liquid chromatography (HPLC. A total of 40.6 mg of oridonin with the purity of 73.5% was obtained in less than 100 min from 100 mg of crude Isodon rubescens extract. The chemical structure of the compound was identified by IR, 1H-NMR and 13C-NMR.

High Isolation Single-Pole Four-Throw RF MEMS Switch Based on Series-Shunt Configuration

Directory of Open Access Journals (Sweden)

Tejinder Singh

2014-01-01

Full Text Available This paper presents a novel design of single-pole four-throw (SP4T RF-MEMS switch employing both capacitive and ohmic switches. It is designed on high-resistivity silicon substrate and has a compact area of 1.06 mm2. The series or ohmic switches have been designed to provide low insertion loss with good ohmic contact. The pull-in voltage for ohmic switches is calculated to be 7.19 V. Shunt or capacitive switches have been used in each port to improve the isolation for higher frequencies. The proposed SP4T switch provides excellent RF performances with isolation better than 70.64 dB and insertion loss less than 0.72 dB for X-band between the input port and each output port.

Qualification of high damping seismic isolation bearings for the ALMR

International Nuclear Information System (INIS)

Tajirian, F.F.; Gluekler, E.L.; Chen, W.P.; Kelly, J.M.

1992-01-01

The Advanced Liquid Metal Reactor (ALMR) seismic isolation system consists of high damping steel-laminated elastomeric bearings. This type of bearing is used worldwide to isolate buildings and large critical components. A comprehensive testing program has been developed to qualify the use of this system for the ALMR. The program includes material characterization tests, various scale bearing tests, full-size bearing tests, shake table tests, and long-term aging tests. The main tasks and objectives of this program are described in the paper. Additionally, a detailed assessment of completed ALMR bearing test results will be provided. This assessment will be mainly based on half-scale bearing tests performed at the Earthquake Engineering Research Center (EERC) of the University of California at Berkeley and at the Energy Technology Engineering Center (ETEC). These tests were funded by the U.S. Department of Energy (DOE). Both static and dynamic tests were performed. Bearings with two types of end connections were tested: dowelled and bolted. The parameters examined will include the vertical, horizontal stiffness and damping of the bearings under different loading conditions up to failure. This will determine the available margins in the bearings above the design vertical load and horizontal displacement. Additionally, the self-centering capability of the bearings after an earthquake will be addressed. On the basis of these findings, recommendations can be made if necessary, to improve current manufacturing procedures, quality control, and procurement specifications. (author)

Preparative isolation and purification of theaflavins and catechins by high-speed countercurrent chromatography.

Science.gov (United States)

Wang, Kunbo; Liu, Zhonghua; Huang, Jian-an; Dong, Xinrong; Song, Lubing; Pan, Yu; liu, Fang

2008-05-15

High-speed countercurrent chromatography (HSCCC) has been applied for the separation of theaflavins and catechins. The HSCCC run was carried out with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water-acetic acid (1:5:1:5:0.25, v/v) by eluting the lower aqueous phase at 2 ml/min at 700 rpm. The results indicated that pure theaflavin, theaflavins-3-gallate, theaflavins-3'-gallate and theaflavin-3,3'-digallate could be obtained from crude theaflavins sample and black tea. The structures of the isolated compounds were positively confirmed by (1)H NMR and (13)C NMR, MS analysis, HPLC data and TLC data. Meanwhile, catechins including epigallocatechin gallate, gallocatechin gallate, epicatechin gallate and epigallocatechin were isolated from the aqueous extract of green tea by using the same solvent system. This study developed a modified method combined with enrichment theaflavins method by using HSCCC for separation of four individual theaflavins, especially for better separation of theaflavins monogallates.

An alternative model for the origin of gaps in circumstellar disks

OpenAIRE

Vorobyov, Eduard I.; Regaly, Zsolt; Guedel, Manuel; Lin, D. N. C.

2016-01-01

Motivated by recent observational and numerical studies suggesting that collapsing protostellar cores may be replenished from the local environment, we explore the evolution of protostellar cores submerged in the external counter-rotating environment. These models predict the formation of counter-rotating disks with a deep gap in the gas surface density separating the inner disk (corotating with the star) and the outer counter-rotating disk. The properties of these gaps are compared to those ...

New high temperature plasma ion source for the TRISTAN ISOL facility

International Nuclear Information System (INIS)

Piotrowski, A.; Gill, R.L.; McDonald, D.C.

1986-08-01

A vigorous program of ion source development at TRISTAN has led to several types of ion sources that are especially suited to extended operation at a reactor-based ISOL facility. The latest of these is a high temperature plasma ion source in which a 5 gm 235 U target is located in the cathode and can be heated to 2500 0 C. The ion source has a lifetime of >1000 hours and produces a wide array of elements, including Pd. Off-line investigations indicate that the source functions primarily in an electron impact mode of ionization and exhibits typical ionzation efficiencies of >30% for Xe

Radioactive waste isolation in salt: peer review of the Office of Nuclear Waste Isolation's report on Functional Design Criteria for a Repository for High-Level Radioactive Waste

International Nuclear Information System (INIS)

Hambley, D.F.; Russell, J.E.; Busch, J.S.; Harrison, W.; Edgar, D.E.; Tisue, M.W.

1984-08-01

This report summarizes Argonne's review of the Office of Nuclear Waste Isolation's (ONWI's) draft report entitled Functional Design Criteria for High-Level Nuclear Waste Repository in Salt, dated January 23, 1984. Recommendations are given for improving the ONWI draft report

High level of resistance to aztreonam and ticarcillin in Pseudomonas aeruginosa isolated from soil of different crops in Brazil.

Science.gov (United States)

Pitondo-Silva, André; Martins, Vinicius Vicente; Fernandes, Ana Flavia Tonelli; Stehling, Eliana Guedes

2014-03-01

Pseudomonas aeruginosa can be found in water, soil, plants and, human and animal fecal samples. It is an important nosocomial pathogenic agent characterized by an intrinsic resistance to multiple antimicrobial agents and the ability to develop high-level (acquired) multidrug resistance through some mechanisms, among them, by the acquisition of plasmids and integrons, which are mobile genetic elements. In this study, 40 isolates from Brazilian soil were analyzed for antibiotic resistance, presence of integrons and plasmidial profile. The results demonstrated that the vast majority of the isolates have shown resistance for aztreonam (92.5%, n=37) and ticarcillin (85%, n=34), four isolates presented plasmids and eight isolates possess the class 1 integron. These results demonstrated that environmental isolates of P. aeruginosa possess surprising antibiotic resistance profile to aztreonam and ticarcillin, two antimicrobial agents for clinical treatment of cystic fibrosis patients and other infections occurred by P. aeruginosa. Copyright © 2014 Elsevier B.V. All rights reserved.

Computational design of high efficiency release targets for use at ISOL facilities

CERN Document Server

Liu, Y

1999-01-01

This report describes efforts made at the Oak Ridge National Laboratory to design high-efficiency-release targets that simultaneously incorporate the short diffusion lengths, high permeabilities, controllable temperatures, and heat-removal properties required for the generation of useful radioactive ion beam (RIB) intensities for nuclear physics and astrophysics research using the isotope separation on-line (ISOL) technique. Short diffusion lengths are achieved either by using thin fibrous target materials or by coating thin layers of selected target material onto low-density carbon fibers such as reticulated-vitreous-carbon fiber (RVCF) or carbon-bonded-carbon fiber (CBCF) to form highly permeable composite target matrices. Computational studies that simulate the generation and removal of primary beam deposited heat from target materials have been conducted to optimize the design of target/heat-sink systems for generating RIBs. The results derived from diffusion release-rate simulation studies for selected t...

Seminational surveillance of fungemia in Denmark: notably high rates of fungemia and numbers of isolates with reduced azole susceptibility

DEFF Research Database (Denmark)

Arendrup, Maiken Cavling; Fuursted, Kurt; Gahrn-Hansen, Bente

2005-01-01

laboratory systems documented a continuous increase of candidemia cases since the early 1990s. For the 272 susceptibility-tested isolates, MICs of amphotericin B and caspofungin were within the limits expected for the species or genus. However, decreased azole susceptibility, defined as a fluconazole MIC...... of >8 microg/ml and/or itraconazole MIC of >0.125 microg/ml, was detected for 11 Candida isolates that were neither C. glabrata nor C. krusei. Including intrinsically resistant fungi, we detected decreased susceptibility to fluconazole and/or itraconazole in 87 (32%) current Danish bloodstream fungal...... isolates. We showed a continuous increase of fungemia in Denmark and an annual rate in 2003 to 2004 higher than in most other countries. The proportion of bloodstream fungal isolates with reduced susceptibility to fluconazole and/or itraconazole was also notably high....

High Prevalence of Escherichia coli-Producing CTX-M-15 Extended-Spectrum Beta-Lactamases in Poultry and Human Clinical Isolates in Romania.

Science.gov (United States)

Maciuca, Iuliana E; Williams, Nicola J; Tuchilus, Cristina; Dorneanu, Olivia; Guguianu, Eleonora; Carp-Carare, Catalin; Rimbu, Cristina; Timofte, Dorina

2015-12-01

Use of antibiotics in food animals may contribute to development and spread of resistant organisms, particularly so in some countries. The aim of this study was two-fold; first, to establish the prevalence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in chicken production in a region within Romania. Second, to study the relatedness of ESBL-producing E. coli isolates recovered from broilers, abattoir workers where the chickens were slaughtered and from the human clinical specimens from two regional hospitals. The results indicated a very high (69%) rate of carriage of ESBL and AmpC-producing E. coli in chickens with 36% CTX-M producers. Sequencing showed that chickens in Romania have the highest worldwide prevalence (53%) of blaCTX-M-15 reported in poultry E. coli isolates. The majority (53%) of the extended-spectrum cephalosporin-resistant E. coli carried plasmid-mediated blaampC genes, mostly blaCMY-2 type, one of the highest prevalences reported in Europe. The predominant CTX-M type found in the human clinical E. coli isolates was blaCTX-M-15 and most isolates coharbored blaOXA-1, blaTEM, and aac(6')-ib-cr. The majority (60%) of the human clinical isolates belonged to the pandemic virulent clone B2-ST131. The clonal relationship between broiler and the human CTX-M-producing E. coli isolates was assessed by macrorestriction pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), which indicated strain diversity with no common STs found between human and poultry isolates. Moreover, IncI1 was the most prevalent replicon found in broiler ESBL-producing E. coli isolates and also in transconjugants, indicating that plasmids and not clonal spread may play a role in the transfer of blaCTX-M genes. This study identifies a high prevalence of ESBL-producing E. coli from broiler chickens in Romania with a high occurrence incidence of blaCTX-M-15, which reflects the main ESBL type found in human E. coli infections in this

Demequina lutea sp. nov., isolated from a high Arctic permafrost soil.

Science.gov (United States)

Finster, Kai Waldemar; Herbert, Rodney Andrew; Kjeldsen, Kasper Urup; Schumann, Peter; Lomstein, Bente Aagaard

2009-04-01

Two Gram-stain-positive, pigmented, non-motile, non-spore-forming, pleomorphic, rod-shaped bacteria (strains SV45(T) and SV47), isolated from a permafrost soil collected from the Adventdalen valley, Spitsbergen, northern Norway, have been characterized taxonomically using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the two permafrost isolates formed a distinct phyletic line within the suborder Micrococcineae of the order Actinomycetales. DNA-DNA hybridization analyses indicate that strains SV45(T) and SV47 are closely related (60-69 % relatedness) and belong to the same species, although they show slightly different colony pigmentation. The closest phylogenetic neighbour was Demequina aestuarii JC2054(T), with 96 % 16S rRNA gene sequence similarity. Optimum growth of SV45(T) and SV47 occurred aerobically in the absence of NaCl, but both isolates tolerated up to 2 % NaCl (w/v) in the growth medium. Growth under anaerobic conditions was slow and weak. The peptidoglycan of both isolates was of the A4beta type with l-ornithine as the diamino acid and serine as a component of the interpeptide bridge with either d-aspartate (SV45(T)) or d-glutamate (SV47) as the N-terminal amino acid. The major fatty acids present in both isolates were C(15 : 0) (3.2-8.6 %), iso-C(16 : 0) (5.0-8.9 %), anteiso-C(15 : 0) (59.4-61.5 %), anteiso-C(17 : 0) (4.1-8.8 %) and anteiso-C(15 : 1) (4.4-6.4 %). Isoprenoid quinones were present at exceptionally low levels in both isolates, and only demethylmenaquinone DMK-9(H(4)) could be identified with any degree of confidence. Phylogenetic analysis and differences in physiological and biochemical characteristics between the strains and Demequina aestuarii JC2054(T) indicate that these isolates belong to a novel species within the genus Demequina, for which the name Demequina lutea sp. nov. is proposed. The type strain is SV45(T) (=LMG 24795(T) =DSM 19970(T)).

Tracing the External Origin of the AGN Gas Fueling Reservoir

Directory of Open Access Journals (Sweden)

Sandra I. Raimundo

2018-01-01

Full Text Available Near-infrared observations of the active galaxy MCG–6-30-15 provide strong evidence that its molecular gas fueling reservoir is of external origin. MCG–6-30-15 has a counter-rotating core of stars within its central 400 pc and a counter-rotating disc of molecular gas that extends as close as ~50–100 pc from the central black hole. The gas counter-rotation establishes that the gas reservoir in the center of the galaxy originates from a past external accretion event. In this contribution we discuss the gas and stellar properties of MCG–6-30-15, its past history and how the findings on this galaxy can be used to understand AGN fueling in S0 galaxies with counter-rotating structures.

Dielectric isolation for power integrated circuits; Isolation dielectrique enterree pour les circuits integres de puissance

Energy Technology Data Exchange (ETDEWEB)

Zerrouk, D.

1997-07-18

Considerable efforts have been recently directed towards integrating onto the same chip, sense or protection elements that is low voltage analog and/or digital control circuitry together with high voltage/high current devices. Most of these so called `smart power` devices use either self isolation, junction isolation or Silicon-On-Insulator (SOI) to integrate low voltage elements with vertical power devices. Dielectric isolation is superior to the other isolation techniques such as self isolation or junction isolation. Thesis work consists of the study of the feasibility of a dielectric technology based on the melting and the solidification in a Rapid Thermal Processing furnace (RTP), of thick polysilicon films deposited on oxide. The purpose of this technique is to obtain substrate with localized SOI structures for smart power applications. SOI technology offers significant potential advantages, such as non-occurrence of latch-up in CMOS structures, high packaging density, low parasitic capacitance and the possibility of 3D structures. In addition, SOI technology using thick silicon films (10-100 {mu}m) offers special advantages for high voltage integrated circuits. Several techniques have been developed to form SOI films. Zone melting recrystallization is one of the most promising for localized SOI. The SOI structures have first been analyzed in term of extended defects. N-channel MOSFET`s transistors have also been fabricated in the SOI substrates and electrically characterized (threshold voltages, off-state leakage current, mobilities,...). The SOI transistors exhibit good characteristics, although inferior to witness transistors. The recrystallized silicon films are therefore found to be suitable for the fabrication of SOI devices. (author) 106 refs.

High prevalence of plasmid-mediated 16S rRNA methylase gene rmtB among Escherichia coli clinical isolates from a Chinese teaching hospital

Directory of Open Access Journals (Sweden)

Zhang Xue-qing

2010-06-01

Full Text Available Abstract Background Recently, production of 16S rRNA methylases by Gram-negative bacilli has emerged as a novel mechanism for high-level resistance to aminoglycosides by these organisms in a variety of geographic locations. Therefore, the spread of high-level aminoglycoside resistance determinants has become a great concern. Methods Between January 2006 and July 2008, 680 distinct Escherichia coli clinical isolates were collected from a teaching hospital in Wenzhou, China. PCR and DNA sequencing were used to identify 16S rRNA methylase and extended-spectrum β-lactamase (ESBL genes, including armA and rmtB, and in situ hybridization was performed to determine the location of 16S rRNA methylase genes. Conjugation experiments were subsequently performed to determine whether aminoglycoside resistance was transferable from the E. coli isolates via 16S rRNA methylase-bearing plasmids. Homology of the isolates harboring 16S rRNA methylase genes was determined using pulse-field gel electrophoresis (PFGE. Results Among the 680 E. coli isolates, 357 (52.5%, 346 (50.9% and 44 (6.5% isolates were resistant to gentamicin, tobramycin and amikacin, respectively. Thirty-seven of 44 amikacin-resistant isolates harbored 16S rRNA methylase genes, with 36 of 37 harboring the rmtB gene and only one harboring armA. The positive rates of 16S rRNA methylase genes among all isolates and amikacin-resistant isolates were 5.4% (37/680 and 84.1% (37/44, respectively. Thirty-one isolates harboring 16S rRNA methylase genes also produced ESBLs. In addition, high-level aminoglycoside resistance could be transferred by conjugation from four rmtB-positive donors. The plasmids of incompatibility groups IncF, IncK and IncN were detected in 34, 3 and 3 isolates, respectively. Upstream regions of the armA gene contained ISCR1 and tnpU, the latter a putative transposase gene,. Another putative transposase gene, tnpD, was located within a region downstream of armA. Moreover, a

Isolation, characterization, virulence and immunogenicity testing of field isolates of Pasteurella multocida, Staphylococcus aureus, and Streptococcus agalactiae in laboratory settings.

Science.gov (United States)

Qudratullah; Muhammad, G; Saqib, M; Bilal, M Qamar

2017-08-01

The present study was designed to investigate isolation, characterization, virulence and immunogenicity testing of field isolates of Pasteurella multocida, Staphylococcus aureus, and Streptococcus agalactiae in rabbits and mice. Isolates of P. multocida, S. aureus and Str. agalactiae recovered from field cases of Hemorragic septicemia and mastitis were scrutinized for virulence/pathogenicity and immunogenicity. Mouse LD 50 of P. multocida showed that P. multocida isolate No.1 was more virulent than isolates No. 2 and 3. Virulence of isolate No.1S. aureus and Str. agalactiae revealed that 100, 80% rabbits died within 18h of inoculation. Seven-digit numerical profiles of these 4 isolates with API ® Staph test strips isolates, No.1 (6736153) showed good identification (S. aureus id=90.3%). Indirect ELISA-based serum antibody titers to P. multocida isolate No.1, S. aureus No.1, Str. agalactiae, isolate No.1 elicited high antibody titers 1.9, 1.23, 1.12 respectively. All the pathogens of Isolate No. 1 (P. multocida, S. aureus Str. agalactiae), were high antibody than others isolates. Copyright © 2017 Elsevier B.V. All rights reserved.

A New Approach to High Efficincy in Isolated Boost Converters for High-Power Low-Voltage Fuel Cell Apllications

DEFF Research Database (Denmark)

Nymand, Morten; Andersen, Michael A. E.

2008-01-01

A new low-leakage-inductance low-resistance design approach to low-voltage high-power isolated boost converters is presented. Very low levels of parasitic circuit inductances are achieved by optimizing transformer design and circuit lay-out. Primary side voltage clamp circuits can be eliminated...... by the use of power MOSFETs fully rated for repetitive avalanche. Voltage rating of primary switches can now be reduced, significantly reducing switch on-state losses. Finally, silicon carbide rectifying diodes allow fast diode turn-off, further reducing losses. Test results from a 1.5 kW full-bridge boost...... converter verify theoretical analysis and demonstrate very high efficiency. Worst case efficiency, at minimum input voltage maximum power, is 96.8 percent and maximum efficiency reaches 98 percent....

High-level pullulan production by Aureobasidium pullulans var. melanogenium P16 isolated from mangrove system.

Science.gov (United States)

Ma, Zai-Chao; Fu, Wen-Juan; Liu, Guang-Lei; Wang, Zhi-Peng; Chi, Zhen-Ming

2014-06-01

After over 100 strains of Aureobasidium spp. isolated from mangrove system were screened for their ability to produce exopolysaccharide (EPS), it was found that Aureobasidium pullulans var. melanogenium P16 strain among them could produce high level of EPS. Under the optimal conditions, 65.3 g/L EPS was produced by the P16 strain within 120 h at flask level. During 10-L batch fermentation, when the medium contained 120.0 g/L sucrose, 67.4 g/L of EPS and 23.1 g/L of cell dry weight in the culture were obtained within 120 h, leaving 0.78 g/L of reducing sugar and 11.4 g/L of total sugar in the fermented medium. It should be stressed that during the fermentation, no melanin was observed. After purification, the purified EPS was confirmed to be pullulan. This is the first time to report that A. pullulans var. melanogenium P16 strain isolated from the mangrove system can produce high level of pullulan.

DNA-A of a highly pathogenic Indian cassava mosaic virus isolated from Jatropha curcas causes symptoms in Nicotiana benthamiana.

Science.gov (United States)

Wang, Gang; Sun, Yanwei; Xu, Ruirui; Qu, Jing; Tee, Chuansia; Jiang, Xiyuan; Ye, Jian

2014-04-01

Jatropha curcas mosaic disease (JcMD) is a newly emerging disease that has been reported in Africa and India. Here, we report the complete nucleotide sequence of a new Indian cassava mosaic virus isolate (ICMV-SG) from Singapore. Infection of ICMV-SG showed more severe JcMD in Jatropha curcas and Nicotiana benthamiana than the other ICMV isolates reported previously, though ICMV-SG shares high sequence identity with the other ICMV isolates. Agroinfectious DNA-A alone sufficiently induced systemic symptoms in N. benthamiana, but not in J. curcas. Results from agroinfection assays showed that systemic infection of ICMV-SG in J. curcas required both DNA-A and DNA-B components.

High quality RNA isolation from Aedes aegypti midguts using laser microdissection microscopy

Directory of Open Access Journals (Sweden)

Gobert Geoffrey N

2011-05-01

Full Text Available Abstract Background Laser microdissection microscopy (LMM has potential as a research tool because it allows precise excision of target tissues or cells from a complex biological specimen, and facilitates tissue-specific sample preparation. However, this method has not been used in mosquito vectors to date. To this end, we have developed an LMM method to isolate midgut RNA using Aedes aegypti. Results Total RNA was isolated from Ae. aegypti midguts that were either fresh-frozen or fixed with histological fixatives. Generally, fresh-frozen tissue sections are a common source of quality LMM-derived RNA; however, our aim was to develop an LMM protocol that could inactivate pathogenic viruses by fixation, while simultaneously preserving RNA from arbovirus-infected mosquitoes. Three groups (10 - 15 mosquitoes per group of female Ae. aegypti at 24 or 48-hours post-blood meal were intrathoracically injected with one of seven common fixatives (Bouin's, Carnoy's, Formoy's, Cal-Rite, 4% formalin, 10% neutral buffered formalin, or zinc formalin to evaluate their effect on RNA quality. Total RNA was isolated from the fixed abdomens using a Trizol® method. The results indicated that RNA from Carnoy's and Bouin's fixative samples was comparable to that of fresh frozen midguts (control in duplicate experiments. When Carnoy's and Bouin's were used to fix the midguts for the LMM procedure, however, Carnoy's-fixed RNA clearly showed much less degradation than Bouin's-fixed RNA. In addition, a sample of 5 randomly chosen transcripts were amplified more efficiently using the Carnoy's treated LMM RNA than Bouin's-fixed RNA in quantitative real-time PCR (qRT-PCR assays, suggesting there were more intact target mRNAs in the Carnoy's fixed RNA. The yields of total RNA ranged from 0.3 to 19.0 ng per ~3.0 × 106 μm2 in the LMM procedure. Conclusions Carnoy's fixative was found to be highly compatible with LMM, producing high quality RNA from Ae. aegypti midguts while

Rapid screening of rpoB and katG mutations in Mycobacterium tuberculosis isolates by high-resolution melting curve analysis

Directory of Open Access Journals (Sweden)

M Haeili

2014-01-01

Full Text Available Background: Early detection of multidrug-resistant tuberculosis (MDR-TB is essential to prevent its transmission in the community and initiate effective anti-TB treatment regimen. Materials and Methods: High-resolution melting curve (HRM analysis was evaluated for rapid detection of resistance conferring mutations in rpoB and katG genes. We screened 95 Mycobacterium tuberculosis clinical isolates including 20 rifampin resistant (RIF-R, 21 isoniazid resistant (INH-R and 54 fully susceptible (S isolates determined by proportion method of drug susceptibility testing. Nineteen M. tuberculosis isolates with known drug susceptibility genotypes were used as references for the assay validation. The nucleotide sequences of the target regions rpoB and katG genes were determined to investigate the frequency and type of mutations and to confirm HRM results. Results: HRM analysis of a 129-bp fragment of rpoB allowed correct identification of 19 of the 20 phenotypically RIF-R and all RIF-S isolates. All INH-S isolates generated wild-type HRM curves and 18 out of 21 INH-R isolates harboured any mutation in 109-bp fragment of katG exhibited mutant type HRM curves. However, 1 RIF-R and 3 INH-R isolates were falsely identified as susceptible which were confirmed for having no mutation in their target regions by sequencing. The main mutations involved in RIF and INH resistance were found at codons rpoB531 (60% of RIF-R isolates and katG315 (85.7% of INH-R isolates, respectively. Conclusion: HRM was found to be a reliable, rapid and low cost method to characterise drug susceptibility of clinical TB isolates in resource-limited settings.

Three distinct clones of carbapenem-resistant Acinetobacter baumannii with high diversity of carbapenemases isolated from patients in two hospitals in Kuwait

Directory of Open Access Journals (Sweden)

N.A. Al-Sweih

2012-02-01

Full Text Available Summary: Objectives: This study was undertaken to investigate the clonal relatedness of multidrug-resistant (MDR Acinetobacter baumannii isolates collected from patients in two teaching hospitals in Kuwait. Materials and methods: Clinically significant consecutive isolates of A. baumannii obtained from patients in the Mubarak (36 and Adan (58 hospitals over a period of 6 months were studied. These isolates were identified using molecular methods, and their antimicrobial susceptibility was determined by the Etest method. The mechanism of resistance to carbapenem was investigated by PCR, and pulsed-field gel electrophoresis (PFGE was used to determine the clonal relatedness of MDR isolates. Results: Of the 94 isolates investigated, 80 (85.1% were multidrug resistant (MDR. The A. baumannii PFGE clone A and subclone A1 were the most prevalent in patients infected with MDR isolates. Fifty-five (94.8% and 15 (41.7% of the MDR isolates from the Adan and Mubarak hospitals, respectively, belonged to PFGE clone A; isolates in this group showed higher resistance rates to antibiotics than isolates form other groups. Of the 94 isolates, 40 (42.6% were resistant to either imipenem or meropenem or to both (CRAB. Most CRAB isolates (29/40 or 72.5% carried bla genes, which code for MBL (VIM-2 and IMP-1 enzymes. Two isolates harbored blaOXA-23. Conclusion: Three distinct clones of CRAB were isolated, providing evidence of a high diversity of carbapenemases among our geographically related isolates. Keywords: MDR A. baumannii, Genotypes, bla genes, Kuwait hospitals

Isolation, Identification, and Characterization of a New Highly Pathogenic Field Isolate of Mycobacterium avium spp. avium

Directory of Open Access Journals (Sweden)

Liangquan Zhu

2018-01-01

Full Text Available Avian tuberculosis is a chronic, contagious zoonotic disease affecting birds, mammals, and humans. The disease is most often caused by Mycobacterium avium spp. avium (MAA. Strain resources are important for research on avian tuberculosis and vaccine development. However, there has been little reported about the newly identified MAA strain in recent years in China. In this study, a new strain was isolated from a fowl with symptoms of avian tuberculosis by bacterial culture. The isolated strain was identified to be MAA by culture, staining, and biochemical and genetic analysis, except for different colony morphology. The isolated strain was Ziehl-Zeelsen staining positive, resistant to p-nitrobenzoic acid, and negative for niacin production, Tween-80 hydrolysis, heat stable catalase and nitrate production. The strain had the DnaJ gene, IS1245, and IS901, as well. Serum agglutination indicated that the MAA strain was of serotype 1. The MAA strain showed strong virulence via mortality in rabbits and chickens. The prepared tuberculin of the MAA strain had similar potency compared to the MAA reference strain and standard tuberculin via a tuberculin skin test. Our studies suggested that this MAA strain tends to be a novel subtype, which might enrich the strain resource of avian tuberculosis.

Virulence profiles and innate immune responses against highly lethal, multidrug-resistant nosocomial isolates of Acinetobacter baumannii from a tertiary care hospital in Mexico

Science.gov (United States)

Gayosso-Vázquez, Catalina; Fernández-Vázquez, José Luis; Jarillo-Quijada, Ma Dolores; Rivera-Benítez, César; Santos-Preciado, José Ignacio

2017-01-01

Virulence profiles and innate immune responses were studied in Acinetobacter baumannii from nosocomial infections collected over one year in a tertiary care hospital in Mexico. A. baumannii were identified by VITEK 2 System followed by susceptibility tests. Carbapenemase genes, active efflux mechanism to imipenem and meropenem and outer membrane proteins profile were analyzed to evaluate their role on the activity of carbapenem resistance. All isolates were genotyped by pulsed field gel electrophoresis. The ability to form biofilm was determined on a polystyrene surface. The resistance to complement was determined with a pooled human normal serum and TNFα release by infected macrophages was determined by ELISA. The 112 isolates from this study were associated with a 52% of mortality. All were resistance to β-lactams, fluoroquinolones, and trimethroprim-sulfamethoxal, 96 and 90% were resistant to meropenem and imipenem, respectively, but with high susceptibility to polymyxin B, colistin and tigecyclin. Isolates were classified in 11 different clones. Most isolates, 88% (99/112), were metallo-β-lactamases and carbapenemases producers, associated in 95% with the presence of blaOXA-72 gene. Only 4/99 and 1/99 of the carbapenem-resistant isolates were related to efflux mechanism to meropenem or imipenem resistance, respectively. The loss of expression of 22, 29, and/or 33-36-kDa proteins was detected in 8/11 of the clinical isolates with resistance to carbapenem. More than 96% (108/112) of the isolates were high producers of biofilms on biotic surfaces. Finally, all isolates showed variable resistance to normal human serum activity and were high inductors of TNFα release by macrophages. In summary, these results suggest that multidrug-resistant A. baumannii can persist in the hospital environment through its ability to form biofilms. The high mortality observed was due to their ability to survive normal human serum activity and capability to induce potent

Mycobacterial RNA isolation optimized for non-coding RNA: high fidelity isolation of 5S rRNA from Mycobacterium bovis BCG reveals novel post-transcriptional processing and a complete spectrum of modified ribonucleosides.

Science.gov (United States)

Hia, Fabian; Chionh, Yok Hian; Pang, Yan Ling Joy; DeMott, Michael S; McBee, Megan E; Dedon, Peter C

2015-03-11

A major challenge in the study of mycobacterial RNA biology is the lack of a comprehensive RNA isolation method that overcomes the unusual cell wall to faithfully yield the full spectrum of non-coding RNA (ncRNA) species. Here, we describe a simple and robust procedure optimized for the isolation of total ncRNA, including 5S, 16S and 23S ribosomal RNA (rRNA) and tRNA, from mycobacteria, using Mycobacterium bovis BCG to illustrate the method. Based on a combination of mechanical disruption and liquid and solid-phase technologies, the method produces all major species of ncRNA in high yield and with high integrity, enabling direct chemical and sequence analysis of the ncRNA species. The reproducibility of the method with BCG was evident in bioanalyzer electrophoretic analysis of isolated RNA, which revealed quantitatively significant differences in the ncRNA profiles of exponentially growing and non-replicating hypoxic bacilli. The method also overcame an historical inconsistency in 5S rRNA isolation, with direct sequencing revealing a novel post-transcriptional processing of 5S rRNA to its functional form and with chemical analysis revealing seven post-transcriptional ribonucleoside modifications in the 5S rRNA. This optimized RNA isolation procedure thus provides a means to more rigorously explore the biology of ncRNA species in mycobacteria. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

New highly divergent Plum pox virus isolates infecting sour cherry in Russia.

Science.gov (United States)

Chirkov, Sergei; Ivanov, Peter; Sheveleva, Anna; Zakubanskiy, Alexander; Osipov, Gennady

2017-02-01

Unusual Plum pox virus (PPV) isolates (named Tat isolates) were discovered on sour cherry (Prunus cerasus) in Russia. They failed to be recognized by RT-PCR using commonly employed primers specific to the strains C or CR (the only ones that proved able to infect sour cherry) as well as to the strains M and W. Some of them can be detected by RT-PCR using the PPV-D-specific primers P1/PD or by TAS-ELISA with the PPV-C-specific monoclonal antibody AC. Phylogenetic analysis of the 3'-terminal genomic region assigned the Tat isolates into the cluster of cherry-adapted strains. However, they grouped separately from the C and CR strains and from each other as well. The sequence divergence of the Tat isolates is comparable to the differences between the known PPV strains. They may represent new group(s) of cherry-adapted isolates which do not seem to belong to any known strain of the virus. Copyright © 2016. Published by Elsevier Inc.

Flavonoids from the flowers of Impatiens glandulifera Royle isolated by high performance countercurrent chromatography.

Science.gov (United States)

Vieira, Mariana N; Winterhalter, Peter; Jerz, Gerold

2016-01-01

Impatiens glandulifera Royle (Balsaminaceae) is an annual herb from the Himalaya region, currently widespread along European river systems and one of the most important neophyte invading plants in Germany. Exploring the effects of allelopathic plant chemicals is important for the understanding of its ecological impacts in the process of suppression of indigenous plant species. To investigate the chemical composition of Impatiens glandulifera flowers (IGFs) using high performance countercurrent chromatography (HPCCC). The flowers of Impatiens glandulifera were manually separated and extracted with ethanol. LC-ESI-MS/MS was used to characterise the crude extract of IGF. The various flavonoids detected were isolated by HPCCC using of methyl tert-butyl ether-acetonitrile-water (2:2:3, v/v/v). The combination of the data provided by preparative ESI-MS/MS metabolite profiling, LC-ESI-MS/MS, UV-vis and 1D/2D-NMR spectroscopic analysis was used to elucidate the structures of the isolated compounds. HPCCC runs led to the direct isolation of pure dihydromyricetin (ampelopsin), eriodictyol-7-O-glucoside, kaempferol-3-O-glucoside (astragalin) and kaempferol-3-O-6"-malonyl-glucoside, as well as the pre-purification of kaempferol-3-O-rhamno-rhamnosyldiglucoside, quercetin-3-O-galactoside (hyperoside), quercetin and kaempferol in a single step. This is the first report on the flavonoid composition of the species Impatiens glandulifera. The developed protocol was successfully used to isolate the main flavonoids from the crude extract of IGFs. This combined HPCCC and HPLC procedure could be applied to the fast fractionation and recovery of flavonoid derivatives of other plant extracts. Copyright © 2016 John Wiley & Sons, Ltd.

Clotrimazole is highly effective in vitro against feline Sporothrix brasiliensis isolates.

Science.gov (United States)

Gagini, Thalita; Borba-Santos, Luana Pereira; Messias Rodrigues, Anderson; Pires de Camargo, Zoilo; Rozental, Sonia

2017-11-01

Sporothrix brasiliensis, the most virulent species in the Sporothrix schenckii complex, is responsible for the ongoing epidemics of human and animal sporotrichosis in Brazil. Feline outbreaks are usually driven by S. brasiliensis and followed by extensive transmission to humans. Itraconazole is the first-line treatment for both feline and human sporotrichosis; however, reduced sensitivity is an emerging issue. Thus, we investigated the effect of the widely used antifungal clotrimazole - alone or in combination with itraconazole - against the pathogenic (yeast) form of feline and human S. brasiliensis isolates, in vitro. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) values were determined for treatment with clotrimazole and itraconazole, as monotherapy or in combination. In addition, the effect of the drugs on neutral lipid levels and the yeast ultrastructure were evaluated by flow cytometry and transmission electron microscopy (TEM), respectively. The MIC and MFC values show that clotrimazole was more effective than itraconazole against feline S. brasiliensis isolates, while human isolates were more sensitive to itraconazole. Similarly to itraconazole, treatment with clotrimazole induced statistically significant neutral lipid accumulation in S. brasiliensis yeasts, and treated yeasts displayed irregularities in the cell membrane and a thicker cell wall when observed by TEM. Clotrimazole increased the antifungal activity of itraconazole in combination assays, with a synergistic effect for two feline isolates. The strong activity of clotrimazole against feline S. brasiliensis isolates suggests that this drug is potentially a new alternative for the treatment of feline sporotrichosis, alone or in combination with itraconazole.

Molecular characterization of two high-level ceftriaxone-resistant Neisseria gonorrhoeae isolates detected in Catalonia, Spain.

Science.gov (United States)

Cámara, Jordi; Serra, Judit; Ayats, Josefina; Bastida, Teresa; Carnicer-Pont, Dolors; Andreu, Antònia; Ardanuy, Carmen

2012-08-01

The aim of this study was to characterize the first two extended-spectrum cephalosporin-resistant and multidrug-resistant (MDR) Neisseria gonorrhoeae isolates collected from two sexually related patients (men who have sex with men) in Spain. Antimicrobial susceptibility was studied by Etest. Genes involved in quinolone, ceftriaxone and multidrug resistance were amplified by PCR and sequenced in both directions. The isolates were typed by N. gonorrhoeae multi-antigen sequence typing (NG-MAST). The two isolates had the same MDR profile, showing resistance to penicillin (MIC 0.094 mg/L; β-lactamase negative), ceftriaxone (MIC 1.5 mg/L), cefixime (MIC 1.5 mg/L), cefotaxime (MIC 1 mg/L), ciprofloxacin (MIC >32 mg/L) and tetracycline (MIC 1.5 mg/L). NG-MAST showed that both isolates belonged to sequence type (ST) 1407 (porB-908 and tbpB-110). Ciprofloxacin resistance was due to amino acid substitutions in GyrA (S91F and D95G) and ParC (S87R). An A deletion in the promoter of the MtrCDE efflux pump (mtrR) was detected. No changes were detected in the pilQ gene. The outer membrane protein PorB showed two substitutions at G120K and A121N. An L421P substitution was observed in the PBP1A (ponA) sequence. The sequence of PBP2 (penA) showed a mosaic structure related to genotype XXXIV with a single additional amino acid substitution (A501P). This genotype was identical to a recently described French isolate (F89). This is the first reported case of high-level extended-spectrum cephalosporin-resistant N. gonorrhoeae transmission. The molecular typing and MDR genotype suggest possible European spread of this strain, highlighting the need for surveillance and the importance of testing the susceptibility of N. gonorrhoeae to extended-spectrum cephalosporins.

Optimisation of high-quality total ribonucleic acid isolation from cartilaginous tissues for real-time polymerase chain reaction analysis.

Science.gov (United States)

Peeters, M; Huang, C L; Vonk, L A; Lu, Z F; Bank, R A; Helder, M N; Doulabi, B Zandieh

2016-11-01

Studies which consider the molecular mechanisms of degeneration and regeneration of cartilaginous tissues are seriously hampered by problematic ribonucleic acid (RNA) isolations due to low cell density and the dense, proteoglycan-rich extracellular matrix of cartilage. Proteoglycans tend to co-purify with RNA, they can absorb the full spectrum of UV light and they are potent inhibitors of polymerase chain reaction (PCR). Therefore, the objective of the present study is to compare and optimise different homogenisation methods and RNA isolation kits for an array of cartilaginous tissues. Tissue samples such as the nucleus pulposus (NP), annulus fibrosus (AF), articular cartilage (AC) and meniscus, were collected from goats and homogenised by either the MagNA Lyser or Freezer Mill. RNA of duplicate samples was subsequently isolated by either TRIzol (benchmark), or the RNeasy Lipid Tissue, RNeasy Fibrous Tissue, or Aurum Total RNA Fatty and Fibrous Tissue kits. RNA yield, purity, and integrity were determined and gene expression levels of type II collagen and aggrecan were measured by real-time PCR. No differences between the two homogenisation methods were found. RNA isolation using the RNeasy Fibrous and Lipid kits resulted in the purest RNA (A260/A280 ratio), whereas TRIzol isolations resulted in RNA that is not as pure, and show a larger difference in gene expression of duplicate samples compared with both RNeasy kits. The Aurum kit showed low reproducibility. For the extraction of high-quality RNA from cartilaginous structures, we suggest homogenisation of the samples by the MagNA Lyser. For AC, NP and AF we recommend the RNeasy Fibrous kit, whereas for the meniscus the RNeasy Lipid kit is advised.Cite this article: M. Peeters, C. L. Huang, L. A. Vonk, Z. F. Lu, R. A. Bank, M. N. Helder, B. Zandieh Doulabi. Optimisation of high-quality total ribonucleic acid isolation from cartilaginous tissues for real-time polymerase chain reaction analysis. Bone Joint Res 2016

Channel-closing effects in strong-field ionization by a bicircular field

Science.gov (United States)

Milošević, D. B.; Becker, W.

2018-03-01

Channel-closing effects, such as threshold anomalies and resonantlike intensity-dependent enhancements in strong-field ionization by a bicircular laser field are analyzed. A bicircular field consists of two coplanar corotating or counter-rotating circularly polarized fields having different frequencies. For the total detachment rate of a negative ion by a bicircular field we observe threshold anomalies and explain them using the Wigner threshold law and energy and angular momentum conservation. For the corotating bicircular case, these effects are negligible, while for the counter-rotating case they are pronounced and their position depends on the magnetic quantum number of the initial state. For high-order above-threshold ionization of rare-gas atoms by a counter-rotating bicircular laser field we observe very pronounced intensity-dependent enhancements. We find all four types of threshold anomalies known from collision theory. Contrary to the case of linear polarization, channel-closing effects for a bicircular field are visible also in the cutoff region of the electron energy spectrum, which is explained using quantum-orbit theory.

Isolation of radiation resistant fungal strains from highly radioactive field

International Nuclear Information System (INIS)

Adam, Y.M.; Aziz, N.H.; Attaby, H.S.H.

1995-01-01

This study examined the radiation resistance of fungal flora isolated from the hot-lab around the radiation sources, cobalt 137 and radium 226 . The predominant mould species were: Aspergillus flavus, A. Niger, penicillium chrysogenum, cladosporium herbarum, fusarium oxysporum and alternaria citri. The D 10 values of F. Oxysporum; 2.00 KGy, A. Flavus; 1.40 KGy, P. chrysogenum; 1.15 KGy, and A. citri; 0.95 KGy, are about 1.67, 3.10, 1.92 and 1.36 folds as the D 1 0 values of the same isolates recovered from soil

Carbapenem inactivation: a very affordable and highly specific method for phenotypic detection of carbapenemase-producing Pseudomonas aeruginosa isolates compared with other methods.

Science.gov (United States)

Akhi, Mohammad Taghi; Khalili, Younes; Ghotaslou, Reza; Kafil, Hossein Samadi; Yousefi, Saber; Nagili, Behroz; Goli, Hamid Reza

2017-06-01

This investigation was undertaken to compare phenotypic and molecular methods for detection of carbapenemase-producing Pseudomonas aeruginosa. A total of 245 non-duplicated isolates of P. aeruginosa were collected from hospitalized patients. Disc diffusion method was used to identify carbapenem-resistant bacteria. Three phenotypic methods, including Modified Hodge Test (MHT), Modified Carba NP (MCNP) test and Carbapenem Inactivation Method (CIM) were used for investigation of carbapenemase production. In addition, polymerase chain reaction (PCR) was used to detect carbapenemase encoding genes. Of 245 P. aeruginosa isolates investigated, 121 isolates were carbapenem-resistant. Among carbapenem-resistant isolates, 40, 39 and 35 isolates exhibited positive results using MHT, MCNP test and CIM, respectively. PCR indicated the presence of carbapenemase genes in 35 of carbapenem-resistant isolates. MHT showed low sensitivity and specificity for carbapenemase detection among P. aeruginosa isolates in comparison to PCR. CIM was most affordable and highly specific than MCNP test compared with the molecular method.

Isolation, characterization and toxicity of native Bacillus thuringiensis isolates from different hosts and habitats in Iran

Directory of Open Access Journals (Sweden)

Ghassemi-Kahrizeh Akbar

2017-09-01

Full Text Available Bacillus thuringiensis is a Gram-positive, aerobic, facultative anaerobic and endospore-forming bacterium. Different strains of this species have the ability to produce parasporal crystalline inclusions which are toxic to larvae of different insect orders and other invertebrates and cause rapid death of the host. To determine the importance of this species in microbial control, we collected native strains and studied their virulence on the diamondback moth, Plutella xylostella. More than 148 samples were collected from Alborz, Guilan and Mazandaran Provinces. Experimental samples, including soil samples from forests, fruit gardens, agricultural fields, diseased and dead larvae, were transferred to a laboratory in sterile plastic containers. For evaluating B. thuringiensis isolates virulence, a cabbage leaf dip method with 106 cell · ml−1 concentration of various Bt isolates was applied to diamondback moths. Larval mortality was recorded 72 h after treatment. Based on bioassay results, all isolates were classified into three high, medium and low virulence groups. Protein level characterization based on the SDS-PAGE gel analysis showed that two isolates from a high virulence group have proteins of high molecular masses of 121 and 109 kDa. Results revealed that there is a positive correlation between protein masses and virulence of isolates. In addition, this research introduced nine strains that are highly toxic to P. xylostella and would be valuable as insecticidal agents for controlling lepidopteran pests.

Nickel nanoparticle decorated graphene for highly selective isolation of polyhistidine-tagged proteins

Science.gov (United States)

Liu, Jia-Wei; Yang, Ting; Ma, Lin-Yu; Chen, Xu-Wei; Wang, Jian-Hua

2013-12-01

Nickel nanoparticle decorated graphene (GP-Ni) is prepared by one-pot hydrothermal reduction of graphene oxide and nickel cations by hydrazine hydrate in the presence of poly(sodium-p-styrenesulfonate) (PSS). The GP-Ni hybrid is characterized by XRD, TEM, SEM, XPS, Raman and FT-IR spectra, demonstrating the formation of poly-dispersed nickel nanoparticles with an average size of 83 nm attached on the surface of graphene sheets. The GP-Ni hybrid exhibits ferromagnetic behavior with a magnetization saturation of 31.1 emu g-1 at 10 000 Oersted (Oe). The GP-Ni also possesses favorable stability in aqueous medium and rapid magnetic response to an external magnetic field. These make it a novel magnetic adsorbent for the separation/isolation of His6-tagged recombinant proteins from a complex sample matrix (cell lysate). The targeted protein species is captured onto the surface of the GP-Ni hybrid via specific metal affinity force between polyhistidine groups and nickel nanoparticles. The SDS-PAGE assay indicates highly selective separation of His6-tagged Smt A from cell lysate. The GP-Ni hybrid displays favorable performance on the separation/isolation of His6-tagged recombinant proteins with respect to the commercial NTA-Ni2+ column.

Draft Genome Sequence of Komagataeibacter rhaeticus Strain AF1, a High Producer of Cellulose, Isolated from Kombucha Tea.

Science.gov (United States)

Dos Santos, Renato Augusto Corrêa; Berretta, Andresa A; Barud, Hernane da Silva; Ribeiro, Sidney José Lima; González-García, Laura Natalia; Zucchi, Tiago Domingues; Goldman, Gustavo H; Riaño-Pachón, Diego M

2014-07-24

Here, we present the draft genome sequence of Komagatabaeicter rhaeticus strain AF1, which was isolated from Kombucha tea and is capable of producing high levels of cellulose. Copyright © 2014 dos Santos et al.

Isolation rooms for highly infectious diseases: an inventory of capabilities in European countries

DEFF Research Database (Denmark)

Fusco, F M; Puro, V; Baka, A

2009-01-01

Isolation of patients with highly infectious diseases (HIDs) in hospital rooms with adequate technical facilities is essential to reduce the risk of spreading disease. The European Network for Infectious Diseases (EUNID), a project co-funded by European Commission and involving 16 European Union...... on prevailing circumstances. Sporadic HID cases can be managed in the available HIRs. HIRs could also have a role in the initial phases of an influenza pandemic. However, large outbreaks due to natural or to bioterrorist events will need management strategies involving healthcare facilities other than HIRs....

ISOLATION OF GLYCOSIDES FROM THE BARKS OF ILEX ROTUNDA BY HIGH-SPEED COUNTER-CURRENT CHROMATOGRAPHY

Science.gov (United States)

Wang, Chun; Chao, Zhimao; Sun, Wen; Wu, Xiaoyi; Ito, Yoichiro

2013-01-01

Semi-preparative and preparative high-speed counter-current chromatography (HSCCC) were successfully used for isolation of glycosides from 50% ethanol extract of the dried barks of Ilex rotunda Thunb. (Aquifoliaceae) by using a two-phase solvent system composed of ethyl acetate-n-butanol-water (1:6:7, v/v/v). From 1.0 g of the extract, syringaresinol 4',4"-di-o-β-d-glucopyranoside (I, 20.2 mg),, syringin (II, 56.8 mg), sinapaldehyde glucoside (III, 26.2 mg),, syringaresinol 4'-o-β-d-glucopyranoside (IV, 20.4 mg), and pedunculoside (V, 45.1 mg) were obtained by one run of TBE-1000A HSCCC instrument with 1000 mL of column volume. Their structures were identified by IR, MS, and 1H and 13C NMR studies. Glycoside I was isolated from this plant for the first time. PMID:25132792

ISOLATION OF GLYCOSIDES FROM THE BARKS OF ILEX ROTUNDA BY HIGH-SPEED COUNTER-CURRENT CHROMATOGRAPHY.

Science.gov (United States)

Wang, Chun; Chao, Zhimao; Sun, Wen; Wu, Xiaoyi; Ito, Yoichiro

2014-04-01

Semi-preparative and preparative high-speed counter-current chromatography (HSCCC) were successfully used for isolation of glycosides from 50% ethanol extract of the dried barks of Ilex rotunda Thunb. (Aquifoliaceae) by using a two-phase solvent system composed of ethyl acetate-n-butanol-water (1:6:7, v/v/v). From 1.0 g of the extract, syringaresinol 4',4"-di-o-β-d-glucopyranoside ( I , 20.2 mg),, syringin ( II , 56.8 mg), sinapaldehyde glucoside ( III , 26.2 mg),, syringaresinol 4'-o-β-d-glucopyranoside ( IV , 20.4 mg), and pedunculoside ( V , 45.1 mg) were obtained by one run of TBE-1000A HSCCC instrument with 1000 mL of column volume. Their structures were identified by IR, MS, and 1 H and 13 C NMR studies. Glycoside I was isolated from this plant for the first time.

Fault detection and isolation of high temperature proton exchange membrane fuel cell stack under the influence of degradation

Science.gov (United States)

Jeppesen, Christian; Araya, Samuel Simon; Sahlin, Simon Lennart; Thomas, Sobi; Andreasen, Søren Juhl; Kær, Søren Knudsen

2017-08-01

This study proposes a data-drive impedance-based methodology for fault detection and isolation of low and high cathode stoichiometry, high CO concentration in the anode gas, high methanol vapour concentrations in the anode gas and low anode stoichiometry, for high temperature PEM fuel cells. The fault detection and isolation algorithm is based on an artificial neural network classifier, which uses three extracted features as input. Two of the proposed features are based on angles in the impedance spectrum, and are therefore relative to specific points, and shown to be independent of degradation, contrary to other available feature extraction methods in the literature. The experimental data is based on a 35 day experiment, where 2010 unique electrochemical impedance spectroscopy measurements were recorded. The test of the algorithm resulted in a good detectability of the faults, except for high methanol vapour concentration in the anode gas fault, which was found to be difficult to distinguish from a normal operational data. The achieved accuracy for faults related to CO pollution, anode- and cathode stoichiometry is 100% success rate. Overall global accuracy on the test data is 94.6%.

A new high-temperature plasma ion source for the TRISTAN ISOL facility

International Nuclear Information System (INIS)

Piotrowski, A.; Gill, R.L.; McDonald, D.C.

1987-01-01

A vigorous program of ion-source development at TRISTAN has led to several types of ion sources that are especially suited to extended operation at a reactor-based ISOL facility. The latest of these is a high-temperature plasma ion source in which a 5-g 235 U target is located in the cathode and can be heated to 2500 0 C. The ion source has a lifetime of >1000 h and produces a wide array of elements, including palladium. Off-line investigations indicate that the source functions primarily in an electron impact mode of ionization and exhibits typical ionization efficiencies of >30% for xenon. (orig.)

A new high-temperature plasma ion source for the TRISTAN ISOL facility

International Nuclear Information System (INIS)

Piotrowski, A.; Gill, R.L.; McDonald, D.C.

1987-01-01

A vigorous program of ion-source development at TRISTAN has led to several types of ion sources that are especially suited to extended operation at a reactor-based ISOL facility. The latest of these is a high-temperature plasma ion source in which a 5-g /sup 235/U target is located in the cathode and can be heated to 2500 0 C. The ion source has a lifetime of > 1000 h and produces a wide array of elements, including palladium. Off-line investigations indicate that the source functions primarily in an electron impact mode of ionization and exhibits typical ionization efficiencies of > 30% for xenon

Computerized precision control of a synchronous high voltage discharge switch for the beam separation system of the LEP e+/e- collider

International Nuclear Information System (INIS)

Dieperink, J.H.; Finnigan, A.; Kalbreier, W.; Keizer, R.L.; Laffin, M.; Mertens, V.

1989-01-01

Electrostatic separators are used to separate the beams in LEP. The counter-rotating beams are eventually brought into collision in the four low beta insertions, using switches to discharge simultaneously four high voltage (HV) circuits. Each switch consists of four spark gaps mounted in a pressure vessel. A reduction of the gap widths below the self ignition instance by electric motors results in the initiation of the discharges. Synchronization is ensured by the electrical coupling of the electrodes connected to the ground. The design and performance of the computerized precision control of the discharge switch are described. The dynamic characteristics of the prototype switch are also presented. 5 refs., 5 figs

Isolation of rat adrenocortical mitochondria

Energy Technology Data Exchange (ETDEWEB)

Solinas, Paola [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Fujioka, Hisashi [Electron Microscopy Facility, Department of Pharmacology, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Tandler, Bernard [Department of Biological Sciences, School of Dental Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Hoppel, Charles L., E-mail: charles.hoppel@case.edu [Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States); Department of Medicine, Center for Mitochondrial Disease, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 (United States)

2012-10-12

Highlights: Black-Right-Pointing-Pointer A method for isolation of adrenocortical mitochondria from the adrenal gland of rats is described. Black-Right-Pointing-Pointer The purified isolated mitochondria show excellent morphological integrity. Black-Right-Pointing-Pointer The properties of oxidative phosphorylation are excellent. Black-Right-Pointing-Pointer The method increases the opportunity of direct analysis of adrenal mitochondria from small animals. -- Abstract: This report describes a relatively simple and reliable method for isolating adrenocortical mitochondria from rats in good, reasonably pure yield. These organelles, which heretofore have been unobtainable in isolated form from small laboratory animals, are now readily accessible. A high degree of mitochondrial purity is shown by the electron micrographs, as well as the structural integrity of each mitochondrion. That these organelles have retained their functional integrity is shown by their high respiratory control ratios. In general, the biochemical performance of these adrenal cortical mitochondria closely mirrors that of typical hepatic or cardiac mitochondria.

High rate of non-susceptibility to metronidazole and clindamycin in anaerobic isolates: Data from a clinical laboratory from Karachi, Pakistan.

Science.gov (United States)

Sheikh, Sadia Omer; Jabeen, Kauser; Qaiser, Saba; Ahsan, Syed Tanwir; Khan, Erum; Zafar, Afia

2015-06-01

Due to increasing resistance amongst anaerobic pathogens periodic surveillance of resistance has been recommended in regional/local settings. Anaerobic antimicrobial susceptibility testing is not routinely performed in many laboratories in Pakistan, hence absence of local data may lead to inappropriate empirical therapy in serious cases. 121 clinically significant anaerobic strains (26/121; 21% bacteremic isolates) were isolated and saved from 2010 to 2011. Susceptibility testing against metronidazole, clindamycin, co-amoxiclav, meropenem, piperacillin/tazobactam, linezolid and gatifloxacin was performed by determining minimum inhibitory concentrations (MICs). A high proportion of non-susceptible strains to metronidazole (10% of 121 isolates) and clindamycin (12% of 121 isolates) was seen, most noticeable in Bacteroides fragilis. Three Bacteroides species strains were non-susceptible to both metronidazole and clindamycin. One strain of Clostridium species was fully resistant to metronidazole and had intermediate resistance to clindamycin. No resistance to any of the other tested antibiotics was seen. Resistance to metronidazole was higher in bacteremic vs. non bacteremic isolates (p = value 0.07). In our setting where there is a high usage of empirical metronidazole and clindamycin for the treatment of serious anaerobic infections clinicians should be aware of increased resistance to these agents. Periodic surveillance of resistance to anti-anaerobic drugs especially metronidazole and clindamycin should be performed to generate antibiogram and guide appropriate empiric therapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Large-scale Isolation of Highly Pure "Untouched" Regulatory T Cells in a GMP Environment for Adoptive Cell Therapy.

Science.gov (United States)

Haase, Doreen; Puan, Kia Joo; Starke, Mireille; Lai, Tuck Siong; Soh, Melissa Yan Ling; Karunanithi, Iyswariya; San Luis, Boris; Poh, Tuang Yeow; Yusof, Nurhashikin; Yeap, Chun Hsien; Phang, Chew Yen; Chye, Willis Soon Yuan; Chan, Marieta; Koh, Mickey Boon Chai; Goh, Yeow Tee; Bertin-Maghit, Sebastien; Nardin, Alessandra; Ho, Liam Pock; Rotzschke, Olaf

2015-01-01

Adoptive cell therapy is an emerging treatment strategy for a number of serious diseases. Regulatory T (Treg) cells represent 1 cell type of particular interest for therapy of inflammatory conditions, as they are responsible for controlling unwanted immune responses. Initial clinical trials of adoptive transfer of Treg cells in patients with graft-versus-host disease were shown to be safe. However, obtaining sufficient numbers of highly pure and functional Treg cells with minimal contamination remains a challenge. We developed a novel approach to isolate "untouched" human Treg cells from healthy donors on the basis of negative selection using the surface markers CD49d and CD127. This procedure, which uses an antibody cocktail and magnetic beads for separation in an automated system (RoboSep), was scaled up and adapted to be compatible with good manufacturing practice conditions. With this setup we performed 9 Treg isolations from large-scale leukapheresis samples in a good manufacturing practice facility. These runs yielded sufficient numbers of "untouched" Treg cells for immediate use in clinical applications. The cell preparations consisted of viable highly pure FoxP3-positive Treg cells that were functional in suppressing the proliferation of effector T cells. Contamination with CD4 effector T cells was cell types did not exceed 2% in the final product. Remaining isolation reagents were reduced to levels that are considered safe. Treg cells isolated with this procedure will be used in a phase I clinical trial of adoptive transfer into leukemia patients developing graft-versus-host disease after stem cell transplantation.

Could High Mental Demands at Work Offset the Adverse Association Between Social Isolation and Cognitive Functioning? Results of the Population-Based LIFE-Adult-Study.

Science.gov (United States)

Rodriguez, Francisca S; Schroeter, Matthias L; Witte, A Veronica; Engel, Christoph; Löffler, Markus; Thiery, Joachim; Villringer, Arno; Luck, Tobias; Riedel-Heller, Steffi G

2017-11-01

The study investigated whether high mental demands at work, which have shown to promote a good cognitive functioning in old age, could offset the adverse association between social isolation and cognitive functioning. Based on data from the population-based LIFE-Adult-Study, the association between cognitive functioning (Verbal Fluency Test, Trail Making Test B) and social isolation (Lubben Social Network Scale) as well as mental demands at work (O*NET database) was analyzed via linear regression analyses adjusted for age, sex, education, and sampling weights. Cognitive functioning was significantly lower in socially isolated individuals and in individuals working in low mental demands jobs-even in old age after retirement and even after taking into account the educational level. An interaction effect suggested stronger effects of mental demands at work in socially isolated than nonisolated individuals. The findings suggest that working in high mental-demand jobs could offset the adverse association between social isolation and cognitive functioning. Further research should evaluate how interventions that target social isolation and enhance mentally demanding activities promote a good cognitive functioning in old age. Copyright © 2017 American Association for Geriatric Psychiatry. Published by Elsevier Inc. All rights reserved.

A High Isolation MIMO Antenna without Decoupling Structure for LTE 700 MHz

Directory of Open Access Journals (Sweden)

Yanjie Wu

2015-01-01

Full Text Available This paper presents a long-term evolution (LTE 700 MHz band multiple-input-multiple-output (MIMO antenna, and high isolation between the two symmetrical antenna elements is obtained without introducing extra decoupling structure. Each antenna element is a combination antenna of PIFA and a meander monopole antenna. The end of the PIFA and the meander monopole antenna are, respectively, overlapped with the 50 Ω microstrip feed line, the two overlapping areas produce additional capacitance which can be considered decoupling structures to enhance the isolation for the MIMO antenna, as well as the impedance matching of the antenna elements. The MIMO antenna is etched on FR4 PCB board with dimensions of 71 × 40 × 1.6 mm3; the edge-to-edge separation of the two antenna elements is only nearly 0.037 λ at 700 MHz. Both simulation and measurement results are used to confirm the MIMO antenna performance; the operating bandwidth is 698–750 MHz with S11≤−6 dB and S21≤−23 dB.

Perspectives of application of synthetic diamonds in polyurethane compositions for development of new high thermal conductivity system of isolation of powerful turbogenerators

International Nuclear Information System (INIS)

Kensits'kij, O.G.; Vigovs'kij, O.V.; Khvalyin, D.Yi.

2017-01-01

Reviewed and analyzed components of modern high-voltage insulation of electrical machines. The expediency of increasing of heat-conducting properties of the system of isolation of stator winding of powerful turbogenerators is justified. The main ways of improving heat transfer in the insulation system the stator windings of the turbogenerators are presented and analyzed. Perspectives of application of composite material based on polyurethane with additives of synthetic diamonds for development of new high thermal conductivity system of isolation of powerful electrical machines are analyzed. The technology by which was created the prototype of the insulating material with the application of diamond powder in a polyurethane composition is described. Executed laboratory experimental researches of the electrophysical parameters of the sample developed insulating material. That showed the perspective of this direction of perfection of isolation.

Isolation and identification of highly pathogenic avian influenza virus subtype H5N1 in peafowl (Pavo cristatus).

Science.gov (United States)

Ismail, Mahmoud Moussa; Khan, Owais Ahmed; Cattoli, Giovanni; Lu, Huaguang

2010-03-01

An outbreak of highly pathogenic avian influenza (HPAI) virus subtype H5N1 was first diagnosed in a "backyard" flock of peafowl (Pavo cristatus) raised on palace premises in the Kingdom of Saudi Arabia in December 3, 2007. The flock consisted of 40 peafowl, and their ages ranged from 3 to 5 years old. Affected birds suffered from depression, anorexia, and white diarrhea. Four dead birds were submitted for HPAI diagnosis at the Central Veterinary Diagnostic Laboratory in Riyadh. Brain and liver tissues and tracheal and cloacal swabs were taken from the dead birds and processed for a real-time reverse transcriptase (RT)-PCR test and virus isolation in specific-pathogen-free embryonating chicken eggs. The H5N1 subtype of avian influenza virus was isolated from the four dead birds and identified by a real-time RT-PCR before and after egg inoculation. The virus isolates were characterized as HPAI H5N1 virus by sequencing analysis. Phylogenetic comparisons revealed that the H5N1 viruses isolated from peafowl belong to the genetic clade 2.2 according to the World Health Organization nomenclature. The peafowl H5N1 virus falls into 2.2.2 sublineage II and clusters with the H5N1 viruses isolated from poultry in Saudi Arabia in 2007-08.

Effect of isolation techniques on the characteristics of pigeon pea (Cajanus cajan) protein isolates.

Science.gov (United States)

Adenekan, Monilola K; Fadimu, Gbemisola J; Odunmbaku, Lukumon A; Oke, Emmanuel K

2018-01-01

In this study, the effect of different isolation techniques on the isolated proteins from pigeon pea was investigated. Water, methanol, ammonium sulfate, and acetone were used for the precipitation of proteins from pigeon pea. Proximate composition, and antinutritional and functional properties of the pigeon pea flour and the isolated proteins were measured. Data generated were statistically analyzed. The proximate composition of the water-extracted protein isolate was moisture 8.30%, protein 91.83%, fat 0.25%, ash 0.05%, and crude fiber 0.05%. The methanol-extracted protein isolate composition was moisture 7.87%, protein 91.83%, fat 0.17%, and ash 0.13%, while crude fiber and carbohydrates were not detected. The composition of the ammonium sulfate-extracted protein isolate was moisture 7.73%, protein 91.73%, fat 0.36, ash 0.13%, and crude fiber 0.67%. The acetone-extracted protein isolate composition was moisture 8.03%, protein 91.50%, ash 0.67%, and fat 0.30%, but crude fiber and carbohydrates were not detected. The isolate precipitated with ammonium sulfate displayed the highest foaming capacity (37.63%) and foaming stability (55.75%). Isolates precipitated with methanol and acetone had the highest water absorption capacity (160%). Pigeon pea protein isolates extracted with methanol and ammonium sulfate had the highest oil absorption capacity of 145%. Protein isolates recovered through acetone and methanol had the highest emulsifying capacity of 2.23% and emulsifying stability of 91.47%, respectively. The proximate composition of the recovered protein isolates were of high purity. This shows the efficiency of the extraction techniques. The isolates had desirable solubility index. All the isolation techniques brought significant impact on the characteristics of the isolated pigeon pea protein.

Single spore isolation and morphological characterization of local Malaysian isolates of rice blast fungus Magnoporthe grisea

Science.gov (United States)

Mishra, Ankitta; Ratnam, Wickneswari; Bhuiyan, Md Atiqur Rahman; Ponaya, Ariane; Jena, Khisord K.

2015-09-01

Rice blast is a destructive disease, caused by the fungal pathogen Magnaporthe grisea. It causes considerable damage to rice and leads to crop loss in rice growing regions worldwide. Although fungicides can be used to control rice blast, they generate additional cost in rice production and contamination of environment and food. Therefore, the use of resistant varieties is thought to be one of the most economically and environmentally efficient ways of crop protection from the disease. Six new local Malaysian isolates of M. grisea were isolated using single spore isolation method. Five isolates were from infected leaf samples collected from Kompleks Latihan MADA, Kedah and one was from Kelantan. These isolates were identified using morphological characteristics and microscopic studies and later confirmed by ITSequences. These isolates were induced to sporulate and used for greenhouse screening on two differential rice varieties: Mahsuri (susceptible) and Pongsu Seribu 2 (resistant). Among the 6 isolates, isolate number 3 was found to be the most virulent showing high sporulation while isolate number 4 was very slow growing, and the least virulent.

High prevalence of methicillin resistance and PVL genes amongStaphylococcus aureus isolates from the nares and skin lesions of pediatric patients with atopic dermatitis

Energy Technology Data Exchange (ETDEWEB)

Cavalcante, F.S. [Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Abad, E.D. [Instituto de Puericultura e Pediatria Martagão Gesteira, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Lyra, Y.C. [Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Saintive, S.B.; Ribeiro, M. [Instituto de Puericultura e Pediatria Martagão Gesteira, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil); Ferreira, D.C. [Centre for Ecological and Evolutionary Studies (Microbial Ecology), Faculty of Mathematics and Natural Science, University of Groningen, Groningen (Netherlands); Programa de Pós Graduação em Odontologia, Universidade Estácio de Sá, Rio de Janeiro, RJ (Brazil); Santos, K.R.N. dos [Departamento de Microbiologia Médica, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ (Brazil)

2015-05-08

Staphylococcus aureus is highly prevalent among patients with atopic dermatitis (AD), and this pathogen may trigger and aggravate AD lesions. The aim of this study was to determine the prevalence of S. aureus in the nares of pediatric subjects and verify the phenotypic and molecular characteristics of the isolates in pediatric patients with AD. Isolates were tested for antimicrobial susceptibility, SCCmectyping, and Panton-Valentine Leukocidin (PVL) genes. Lineages were determined by pulsed-field gel electrophoresis and multilocus sequence typing (MLST). AD severity was assessed with the Scoring Atopic Dermatitis (SCORAD) index. Among 106 patients, 90 (85%) presented S. aureus isolates in their nares, and 8 also presented the pathogen in their skin infections. Two patients had two positive lesions, making a total of 10 S. aureusisolates from skin infections. Methicillin-resistant S. aureus(MRSA) was detected in 24 (26.6%) patients, and PVL genes were identified in 21 (23.3%), including 6 (75%) of the 8 patients with skin lesions but mainly in patients with severe and moderate SCORAD values (P=0.0095). All 24 MRSA isolates were susceptible to trimethoprim/sulfamethoxazole, while 8 isolates had a minimum inhibitory concentration (MIC) to mupirocin >1024 μg/mL. High lineage diversity was found among the isolates including USA1100/ST30, USA400/ST1, USA800/ST5, ST83, ST188, ST718, ST1635, and ST2791. There was a high prevalence of MRSA and PVL genes among the isolates recovered in this study. PVL genes were found mostly among patients with severe and moderate SCORAD values. These findings can help clinicians improve the therapies and strategies for the management of pediatric patients with AD.

High prevalence of methicillin resistance and PVL genes amongStaphylococcus aureus isolates from the nares and skin lesions of pediatric patients with atopic dermatitis

International Nuclear Information System (INIS)

Cavalcante, F.S.; Abad, E.D.; Lyra, Y.C.; Saintive, S.B.; Ribeiro, M.; Ferreira, D.C.; Santos, K.R.N. dos

2015-01-01

Staphylococcus aureus is highly prevalent among patients with atopic dermatitis (AD), and this pathogen may trigger and aggravate AD lesions. The aim of this study was to determine the prevalence of S. aureus in the nares of pediatric subjects and verify the phenotypic and molecular characteristics of the isolates in pediatric patients with AD. Isolates were tested for antimicrobial susceptibility, SCCmectyping, and Panton-Valentine Leukocidin (PVL) genes. Lineages were determined by pulsed-field gel electrophoresis and multilocus sequence typing (MLST). AD severity was assessed with the Scoring Atopic Dermatitis (SCORAD) index. Among 106 patients, 90 (85%) presented S. aureus isolates in their nares, and 8 also presented the pathogen in their skin infections. Two patients had two positive lesions, making a total of 10 S. aureusisolates from skin infections. Methicillin-resistant S. aureus(MRSA) was detected in 24 (26.6%) patients, and PVL genes were identified in 21 (23.3%), including 6 (75%) of the 8 patients with skin lesions but mainly in patients with severe and moderate SCORAD values (P=0.0095). All 24 MRSA isolates were susceptible to trimethoprim/sulfamethoxazole, while 8 isolates had a minimum inhibitory concentration (MIC) to mupirocin >1024 μg/mL. High lineage diversity was found among the isolates including USA1100/ST30, USA400/ST1, USA800/ST5, ST83, ST188, ST718, ST1635, and ST2791. There was a high prevalence of MRSA and PVL genes among the isolates recovered in this study. PVL genes were found mostly among patients with severe and moderate SCORAD values. These findings can help clinicians improve the therapies and strategies for the management of pediatric patients with AD

Antimicrobial activity and high thermostability of a novel BLIS secreted by Enterococcus Mundtii isolated from Lebanese cow’s milk

Directory of Open Access Journals (Sweden)

Imad AL Kassaa

2016-12-01

Full Text Available AL Kassaa, I., Safourim, N., Mostafa, N. and Hamze, M. Antimicrobial activity and high thermostability of a novel BLIS secreted by Enterococcus Mundtii isolated from lebanese cow’s milk. 2016. Lebanese Science Journal, 17(2: 166-176. Lactic acid bacteria (LAB are used in many fields such as fermentation agents, increasing nutritional value and improving organoleptic quality of food. Also they are used as probiotics and preservatives against pathogens and spoilage microbes by producing antimicrobial substances such as bacteriocins. Fifty cow’s milk samples were collected and 175 LAB isolates were isolated and identified by using biochemical method. Fifteen isolates showed an antimicrobial activity against Listeria monocytogenes ATCC® 19115™. One strain, BL4 which showed the strongest activity, was chosen to extract and characterize its antimicrobial substance in order to evaluate its potential use as a new food protective agent. This strain was identified as Enterococcus mundtii by pyrosequencing method. The active substance was extracted using solvent method. This Bacteriocin like Inhibitory Substances “BLIS” can support a high temperature (121 ˚C for a long time and resist pH variation. The BLIS BL4 can be considered as a peptide active against many food pathogen and food-spoilage microbes, such as Listeria monocytogenes and Penicillium spp. BLIS BL4 can be used in food application as bio-preservative to reduce food-spoilage and food-borne diseases in food products.

Isoproterenol attenuates high vascular pressure-induced permeability increases in isolated rat lungs.

Science.gov (United States)

Parker, J C; Ivey, C L

1997-12-01

To separate the contributions of cellular and basement membrane components of the alveolar capillary barrier to the increased microvascular permeability induced by high pulmonary venous pressures (Ppv), we subjected isolated rat lungs to increases in Ppv, which increased capillary filtration coefficient (Kfc) without significant hemorrhage (31 cmH2O) and with obvious extravasation of red blood cells (43 cmH2O). Isoproterenol (20 microM) was infused in one group (Iso) to identify a reversible cellular component of injury, and residual blood volumes were measured to assess extravasation of red blood cells through ruptured basement membranes. In untreated lungs (High Ppv group), Kfc increased 6.2 +/- 1.3 and 38.3 +/- 15.2 times baseline during the 31 and 43 cmH2O Ppv states. In Iso lungs, Kfc was 36.2% (P Kfc increases at moderate Ppv, possibly because of an endothelial effect, but it did not affect red cell extravasation at higher vascular pressures.

Newcastle Disease Viruses Causing Recent Outbreaks Worldwide Show Unexpectedly High Genetic Similarity to Historical Virulent Isolates from the 1940s

Science.gov (United States)

Dimitrov, Kiril M.; Lee, Dong-Hun; Williams-Coplin, Dawn; Olivier, Timothy L.; Miller, Patti J.

2016-01-01

Virulent strains of Newcastle disease virus (NDV) cause Newcastle disease (ND), a devastating disease of poultry and wild birds. Phylogenetic analyses clearly distinguish historical isolates (obtained prior to 1960) from currently circulating viruses of class II genotypes V, VI, VII, and XII through XVIII. Here, partial and complete genomic sequences of recent virulent isolates of genotypes II and IX from China, Egypt, and India were found to be nearly identical to those of historical viruses isolated in the 1940s. Phylogenetic analysis, nucleotide distances, and rates of change demonstrate that these recent isolates have not evolved significantly from the most closely related ancestors from the 1940s. The low rates of change for these virulent viruses (7.05 × 10−5 and 2.05 × 10−5 per year, respectively) and the minimal genetic distances existing between these and historical viruses (0.3 to 1.2%) of the same genotypes indicate an unnatural origin. As with any other RNA virus, Newcastle disease virus is expected to evolve naturally; thus, these findings suggest that some recent field isolates should be excluded from evolutionary studies. Furthermore, phylogenetic analyses show that these recent virulent isolates are more closely related to virulent strains isolated during the 1940s, which have been and continue to be used in laboratory and experimental challenge studies. Since the preservation of viable viruses in the environment for over 6 decades is highly unlikely, it is possible that the source of some of the recent virulent viruses isolated from poultry and wild birds might be laboratory viruses. PMID:26888902

Isolation of cellulose microfibrils - An enzymatic approach

Directory of Open Access Journals (Sweden)

Sain, M.

2006-11-01

Full Text Available Isolation methods and applications of cellulose microfibrils are expanding rapidly due to environmental benefits and specific strength properties, especially in bio-composite science. In this research, we have success-fully developed and explored a novel bio-pretreatment for wood fibre that can substantially improve the microfibril yield, in comparison to current techniques used to isolate cellulose microfibrils. Microfibrils currently are isolated in the laboratory through a combination of high shear refining and cryocrushing. A high energy requirement of these procedures is hampering momentum in the direction of microfibril isolation on a sufficiently large scale to suit potential applications. Any attempt to loosen up the microfibrils by either complete or partial destruction of the hydrogen bonds before the mechanical process would be a step forward in the quest for economical isolation of cellulose microfibrils. Bleached kraft pulp was treated with OS1, a fungus isolated from Dutch Elm trees infected with Dutch elm disease, under different treatment conditions. The percentage yield of cellulose microfibrils, based on their diameter, showed a significant shift towards a lower diameter range after the high shear refining, compared to the yield of cellulose microfibrils from untreated fibres. The overall yield of cellulose microfibrils from the treated fibres did not show any sizeable decrease.

Isolation and characterization of viable Toxoplasma gondii isolates revealed possible high frequency of mixed infection in feral cats ( Felis domesticus) from St Kitts, West Indies.

Science.gov (United States)

Dubey, J P; Moura, L; Majumdar, D; Sundar, N; Velmurugan, G V; Kwok, O C H; Kelly, P; Krecek, R C; Su, C

2009-05-01

Cats are essential in the epidemiology of Toxoplasma gondii because they are the only hosts that can excrete the environmentally resistant oocysts in nature. Samples of serum, feces, and tissues from feral cats from St Kitts, West Indies were examined for T. gondii infection. Antibodies to T. gondii were assayed by the modified agglutination test, and found in 71 of 96 (73.9%) of cats with titres of 1:10 in six, 1: 20 in six,1:40 in seven,1: 80 in three, 1: 160 in 10, 1:320 in 13, 1:640 in nine, and 1:1,280 or higher in 17. Tissues of 10 cats were bio-assayed in mice. Toxoplasma gondii was isolated from tissues of 7 cats; from hearts of 6, from tongue of 5, and brains of 3 cats. All 7 isolates were avirulent for mice. Toxoplasma gondii oocysts were not found in the feces of 51 cats. Genotyping of these 7 T. gondii isolates by 10 multi-locus PCR-RFLP markers, including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, and an apicoplast marker, Apico, revealed 4 genotypes, including clonal Type II, Type III and 2 unique genotypes. Five of the 7 cats had infection with 2 genotypes, indicating high frequency of mixed infection in the cat population on the St Kitts island.

Fragility estimation for seismically isolated nuclear structures by high confidence low probability of failure values and bi-linear regression

International Nuclear Information System (INIS)

Carausu, A.

1996-01-01

A method for the fragility estimation of seismically isolated nuclear power plant structure is proposed. The relationship between the ground motion intensity parameter (e.g. peak ground velocity or peak ground acceleration) and the response of isolated structures is expressed in terms of a bi-linear regression line, whose coefficients are estimated by the least-square method in terms of available data on seismic input and structural response. The notion of high confidence low probability of failure (HCLPF) value is also used for deriving compound fragility curves for coupled subsystems. (orig.)

High resolution UHPLC-MS characterization and isolation of main compounds from the antioxidant medicinal plant Parastrephia lucida (Meyen

Directory of Open Access Journals (Sweden)

Carlos Echiburu-Chau

2017-11-01

Full Text Available High-resolution mass spectrometry is currently used to determine the mass of biologically active compounds in medicinal plants and food and UHPLC-Orbitrap is a relatively new technology that allows fast fingerprinting and metabolomics analysis. Forty-two metabolites including several phenolic acids, flavonoids, coumarines, tremetones and ent-clerodane diterpenes were accurately identified for the first time in the resin of the medicinal plant Parastrephia lucida (Asteraceae a Chilean native species, commonly called umatola, collected in the pre-cordillera and altiplano regions of northern Chile, by means of UHPLC-PDA-HR-MS. This could be possible by the state of the art technology employed, which allowed well resolved total ion current peaks and the proposal of some biosynthetic relationships between the compounds detected. Some mayor compounds were also isolated using HSCCC. The ethanolic extract showed high total polyphenols content and significant antioxidant capacity. Furthermore, several biological assays were performed that determined the high antioxidant capacity found for the mayor compound isolated from the plant, 11- p-coumaroyloxyltremetone.

Characterization of Leishmania isolates from Nepalese patients with visceral leishmaniasis.

Science.gov (United States)

Pandey, Kishor; Yanagi, Testuo; Pandey, Basu Dev; Mallik, Arun Kumar; Sherchand, Jeevan Bahadur; Kanbara, Hiroji

2007-05-01

In Nepal, visceral leishmaniasis (VL) is endemic in 13 districts of the central and eastern regions. A total of 166 bone-marrow aspirates were obtained from patients with suspected VL. Ninety-seven were identified as positive by microscopy, and 29 of those were successfully isolated and cultured. We characterized these isolates by molecular analysis and by their ability to infect mice. PCR-restriction fragment length polymorphism analysis of the mini-exon and the cysteine proteinase b gene showed that all isolates were Leishmania donovani, and the restriction pattern of the Nepalese isolates corresponded to the standard Indian strain of L. donovani but differed from that of the Kenyan strain. The single-strand conformation polymorphism analysis of ribosomal internal transcribed spacer showed no genetic heterogeneity within Nepalese isolates. Intraperitoneal inoculation with the promastigotes of all isolates resulted in amastigote proliferation in the spleen of 20 nude mice, of which ten isolates were highly infective, and ten were moderately infective, including one BALB/c mouse. Of the 20 amastigotes isolated from the spleen of nude mice, only the ten highly infective isolates infected BALB/c mice, of which, two isolates were considered to have low infectivity, three isolates were considered to be moderately infective, and five isolates were considered to be highly infective.

Reynolds-Averaged Turbulence Model Assessment for a Highly Back-Pressured Isolator Flowfield

Science.gov (United States)

Baurle, Robert A.; Middleton, Troy F.; Wilson, L. G.

2012-01-01

The use of computational fluid dynamics in scramjet engine component development is widespread in the existing literature. Unfortunately, the quantification of model-form uncertainties is rarely addressed with anything other than sensitivity studies, requiring that the computational results be intimately tied to and calibrated against existing test data. This practice must be replaced with a formal uncertainty quantification process for computational fluid dynamics to play an expanded role in the system design, development, and flight certification process. Due to ground test facility limitations, this expanded role is believed to be a requirement by some in the test and evaluation community if scramjet engines are to be given serious consideration as a viable propulsion device. An effort has been initiated at the NASA Langley Research Center to validate several turbulence closure models used for Reynolds-averaged simulations of scramjet isolator flows. The turbulence models considered were the Menter BSL, Menter SST, Wilcox 1998, Wilcox 2006, and the Gatski-Speziale explicit algebraic Reynolds stress models. The simulations were carried out using the VULCAN computational fluid dynamics package developed at the NASA Langley Research Center. A procedure to quantify the numerical errors was developed to account for discretization errors in the validation process. This procedure utilized the grid convergence index defined by Roache as a bounding estimate for the numerical error. The validation data was collected from a mechanically back-pressured constant area (1 2 inch) isolator model with an isolator entrance Mach number of 2.5. As expected, the model-form uncertainty was substantial for the shock-dominated, massively separated flowfield within the isolator as evidenced by a 6 duct height variation in shock train length depending on the turbulence model employed. Generally speaking, the turbulence models that did not include an explicit stress limiter more closely

Configurable Radiation Hardened High Speed Isolated Interface ASIC, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — NVE Corporation will design and build an innovative, low cost, flexible, configurable, radiation hardened, galvanically isolated, interface ASIC chip set that will...

A PD-SOI based DTI-LOCOS combined cross isolation technique for minimizing TID radiation induced leakage in high density memory

International Nuclear Information System (INIS)

Qiao Fengying; Pan Liyang; Wu Dong; Liu Lifang; Xu Jun

2014-01-01

In order to minimize leakage current increase under total ionizing dose (TID) radiation in high density memory circuits, a new isolation technique, combining deep trench isolation (DTI) between the wells, local oxidation of silicon (LOCOS) isolation between the devices within the well, and a P-diffused area in order to limit leakage at the isolation edge is implemented in partly-depleted silicon-on-insulator (PD-SOI) technology. This radiation hardening technique can minimize the layout area by more than 60%, and allows flexible placement of the body contact. Radiation hardened transistors and 256 Kb flash memory chips are designed and fabricated in a 0.6 μm PD-SOI process. Experiments show that no obvious increase in leakage current is observed for single transistors under 1 Mrad(Si) radiation, and that the 256 Kb memory chip still functions well after a TID of 100 krad(Si), with only 50% increase of the active power consumption in read mode. (semiconductor devices)

Isolation of Lactic Acid Bacteria with High Biological Activity from Local Fermented Dairy Products

Directory of Open Access Journals (Sweden)

B. Munkhtsetseg

2009-12-01

Full Text Available The thirty-two strains of lactic acid bacteria were isolated from the Mongolian traditional fermented dairy products, among them 25 strains show antimicrobial activity against test microorganisms including Escherichia coli , Staphylococcus aureus , Enterococcus faecalis , Pseudom о nas aeruginosa . Protease sensitivity assay demonstrated that the antimicrobial substances produced by isolates А 23, Т 2 are bacteriocins as their antibacterial activities were eliminated completely after treatment with protease. Identi fi cation of bacteria is being carried out. Among the isolates 22 strains show protease enzyme producing activity. The selected strains isolated from mare’s fermented milk (airag or kumis and yoghurt (tarag show the speci fi c protease activity from 7.9 μ g/ml to 11.9 μ g/ml. The strain T2, isolated from yoghurt exhibited the highest proteolytic activity.

Seismic isolation in New Zealand

International Nuclear Information System (INIS)

Skinner, R.I.; Robinson, W.H.; McVerry, G.H.

1989-01-01

Bridges, buildings, and industrial equipment can be given increased protection from earthquake damage by limiting the earthquake attack through seismic isolation. A broad summary of the seismic responses of base-isolated structures is of considerable assistance for their preliminary design. Seismic isolation as already used in New Zealand consists of a flexible base or support combined with some form of energy-dissipating device, usually involving the hysteretic working of steel or lead. This paper presents examples of the New Zealand experience, where seismic isolation has been used for 42 bridges, 3 buildings, a tall chimney, and high-voltage capacitor banks. Additional seismic response factors, which may be important for nuclear power plants, are also discussed briefly

High Manganese Tolerance and Biooxidation Ability of Serratia marcescens Isolated from Manganese Mine Water in Minas Gerais, Brazil

Directory of Open Access Journals (Sweden)

Natália R. Barboza

2017-10-01

Full Text Available Manganese is an important metal for the maintenance of several biological functions, but it can be toxic in high concentrations. One of the main forms of human exposure to metals, such as manganese (Mn, is the consumption of solar salt contaminated. Mn-tolerant bacteria could be used to decrease the concentration of this metal from contaminated sites through safer environmental-friendly alternative technology in the future. Therefore, this study was undertaken to isolate and identify Mn resistant bacteria from water samples collected from a Mn mine in the Iron Quadrangle region (Minas Gerais, Brazil. Two bacterial isolates were identified as Serratia marcescens based on morphological, biochemical, 16S rDNA gene sequencing and phylogeny analysis. Maximum resistance of the selected isolates against increasing concentrations of Mn(II, up to 1200 mg L-1 was determined in solid media. A batch assay was developed to analyze and quantify the Mn removal capacities of the isolates. Biological Mn removal capacities of over 55% were detected for both isolates. Whereas that mechanism like biosorption, precipitation and oxidation could be explaining the Mn removal, we seek to give an insight into some of the molecular mechanisms adopted by S. marcescens isolates. For this purpose, the following approaches were adopted: leucoberbelin blue I assay, Mn(II oxidation by cell-free filtrate and electron microscopy and energy-dispersive X-ray spectroscopy analyses. Overall, these results indicate that S. marcescens promotes Mn removal in an indirect mechanism by the formation of Mn oxides precipitates around the cells, which should be further explored for potential biotechnological applications for water recycling both in hydrometallurgical and mineral processing operations.

DQ High genotypic diversity among methicillin-resistant Staphylococcus pseudintermedius isolated from canine infections in Denmark

DEFF Research Database (Denmark)

Damborg, Peter; Moodley, Arshnee; Aalbaek, Bent

2016-01-01

genotypic diversity and antimicrobial resistance of clinical MRSP isolates obtained from dogs, including dogs sampled on multiple occasions, in Denmark over a six-year period. For that purpose a total of 46 clinical MRSP isolates obtained from 36 dogs between 2009 and 2014 were subjected to antimicrobial...... susceptibility testing, multilocus-sequence typing (MLST) and SCCmec typing. Results: Twenty-three sequence types were identified with ST71, mostly associated with SCCmec II-III, as the most common occurring in 13 dogs. Among the remaining 33 isolates, 19 belonged to clonal complex (CC) 258 comprising ST258...... resistant and almost all CC258 isolates being susceptible. Sixteen of the 19 CC258 isolates had oxacillin MICs of 0.5 g/L, whereas MICs for CC71 isolates were consistently above 4 g/L. Four of five dogs representing multiple isolates had distinct STs on different sampling events. Conclusions: The overall...

High-resolution observations of the near-surface wind field over an isolated mountain and in a steep river canyon

Science.gov (United States)

B. W. Butler; N. S. Wagenbrenner; J. M. Forthofer; B. K. Lamb; K. S. Shannon; D. Finn; R. M. Eckman; K. Clawson; L. Bradshaw; P. Sopko; S. Beard; D. Jimenez; C. Wold; M. Vosburgh

2015-01-01

A number of numerical wind flow models have been developed for simulating wind flow at relatively fine spatial resolutions (e.g., 100 m); however, there are very limited observational data available for evaluating these high-resolution models. This study presents high-resolution surface wind data sets collected from an isolated mountain and a steep river canyon. The...

Characterization of H5N6 highly pathogenic avian influenza viruses isolated from wild and captive birds in the winter season of 2016-2017 in Northern Japan.

Science.gov (United States)

Hiono, Takahiro; Okamatsu, Masatoshi; Matsuno, Keita; Haga, Atsushi; Iwata, Ritsuko; Nguyen, Lam Thanh; Suzuki, Mizuho; Kikutani, Yuto; Kida, Hiroshi; Onuma, Manabu; Sakoda, Yoshihiro

2017-09-01

On 15 November 2016, a black swan that had died in a zoo in Akita prefecture, northern Japan, was strongly suspected to have highly pathogenic avian influenza (HPAI); an HPAI virus (HPAIV) belonging to the H5N6 subtype was isolated from specimens taken from the bird. After the initial report, 230 cases of HPAI caused by H5N6 viruses from wild birds, captive birds, and domestic poultry farms were reported throughout the country during the winter season. In the present study, 66 H5N6 HPAIVs isolated from northern Japan were further characterized. Phylogenetic analysis of the hemagglutinin gene showed that the H5N6 viruses isolated in northern Japan clustered into Group C of Clade 2.3.4.4 together with other isolates collected in Japan, Korea and Taiwan during the winter season of 2016-2017. The antigenicity of the Japanese H5N6 isolate differed slightly from that of HPAIVs isolated previously in Japan and China. The virus exhibited high pathogenicity and a high replication capacity in chickens, whereas virus growth was slightly lower in ducks compared with that of an H5N8 HPAIV isolate collected in Japan in 2014. Comprehensive analyses of Japanese isolates, including those from central, western, and southern Japan, as well as rapid publication of this information are essential for facilitating greater control of HPAIVs. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

Surface morphology of chitin highly related with the isolated body part of butterfly (Argynnis pandora).

Science.gov (United States)

Kaya, Murat; Bitim, Betül; Mujtaba, Muhammad; Koyuncu, Turgay

2015-11-01

This study was conducted to understand the differences in the physicochemical properties of chitin samples isolated from the wings and the other body parts except the wings (OBP) of a butterfly species (Argynnis pandora). The same isolation method was used for obtaining chitin specimens from both types of body parts. The chitin content of the wings (22%) was recorded as being much higher than the OBP (8%). The extracted chitin samples were characterized via FT-IR, TGA, XRD, SEM, and elemental analysis techniques. Results of these characterizations revealed that the chitins from both structures (wings and OBP) were very similar, except for their surface morphologies. SEM results demonstrated one type of surface morphology for the wings and four different surface morphologies for the OBP. Therefore, it can be hypothesized that the surface morphology of the chitin is highly related with the body part. Copyright © 2015 Elsevier B.V. All rights reserved.

Static and dynamic stability of pneumatic vibration isolators and systems of isolators

Science.gov (United States)

Ryaboy, Vyacheslav M.

2014-01-01

Pneumatic vibration isolation is the most widespread effective method for creating vibration-free environments that are vital for precise experiments and manufacturing operations in optoelectronics, life sciences, microelectronics, nanotechnology and other areas. The modeling and design principles of a dual-chamber pneumatic vibration isolator, basically established a few decades ago, continue to attract attention of researchers. On the other hand, behavior of systems of such isolators was never explained in the literature in sufficient detail. This paper covers a range of questions essential for understanding the mechanics of pneumatic isolation systems from both design and application perspectives. The theory and a model of a single standalone isolator are presented in concise form necessary for subsequent analysis. Then the dynamics of a system of isolators supporting a payload is considered with main attention directed to two aspects of their behavior: first, the static stability of payloads with high positions of the center of gravity; second, dynamic stability of the feedback system formed by mechanical leveling valves. The direct method of calculating the maximum stable position of the center of gravity is presented and illustrated by three-dimensional stability domains; analytic formulas are given that delineate these domains. A numerical method for feedback stability analysis of self-leveling valve systems is given, and the results are compared with the analytical estimates for a single isolator. The relation between the static and dynamic phenomena is discussed.

Isolation of aramid nanofibers for high strength multiscale fiber reinforced composites

Science.gov (United States)

Lin, Jiajun; Patterson, Brendan A.; Malakooti, Mohammad H.; Sodano, Henry A.

2018-03-01

Aramid fibers are famous for their high specific strength and energy absorption properties and have been intensively used for soft body armor and ballistic protection. However, the use of aramid fiber reinforced composites is barely observed in structural applications. Aramid fibers have smooth and inert surfaces that are unable to form robust adhesion to polymeric matrices due to their high crystallinity. Here, a novel method to effectively integrate aramid fibers into composites is developed through utilization of aramid nanofibers. Aramid nanofibers are prepared from macroscale aramid fibers (such as Kevlar®) and isolated through a simple and scalable dissolution method. Prepared aramid nanofibers are dispersible in many polymers due to their improved surface reactivity, meanwhile preserve the conjugated structure and likely the strength of their macroscale counterparts. Simultaneously improved elastic modulus, strength and fracture toughness are observed in aramid nanofiber reinforced epoxy nanocomposites. When integrated in continuous fiber reinforced composites, aramid nanofibers can also enhance interfacial properties by forming hydrogen bonds and π-π coordination to bridge matrix and macroscale fibers. Such multiscale reinforcement by aramid nanofibers and continuous fibers results in strong polymeric composites with robust mechanical properties that are necessary and long desired for structural applications.

Isolation contactor state control system

Energy Technology Data Exchange (ETDEWEB)

Bissontz, Jay E.

2017-05-16

A controller area network (CAN) installed on a hybrid electric vehicle provides one node with control of high voltage power distribution system isolation contactors and the capacity to energize a secondary electro-mechanical relay device. The output of the secondary relay provides a redundant and persistent backup signal to the output of the node. The secondary relay is relatively immune to CAN message traffic interruptions and, as a result, the high voltage isolation contactor(s) are less likely to transition open in the event that the intelligent output driver should fail.

Verification and improvement of analytical modeling of seismic isolation bearings and isolated structures

International Nuclear Information System (INIS)

Forni, M.; La Grotteria, M.; Martelli, A.; Bertola, S.; Bettinali, F.; Dusi, A.; Bergamo, G.; Bonacina, G.

2002-01-01

Due to the complexity of dynamic behaviour of seismic isolation (SI) devices, high cost of their tests and non-negligible number of devices having excellent potential for nuclear applications, several countries judged of great interest to extend validation of their numerical models of such devices to the analysis of experimental data obtained by others. Thus, a four-years Coordinated Research Program (CRP) on Intercomparison of Analysis Methods for Isolated Nuclear Structures, proposed by ENEA (1995), was endorsed by the IAEA in 1995. There, Italy was jointly represented by ENEA, ENEL and ISMES, and supplied test results concerning both High Damping Rubber Bearings (HDRBs) and the MISS (Model of Isolated Steel Structure) mock-up, which had been isolated using such bearings. Test data provided by Italy to the other countries were also re-analysed to improve mathematical models. Aim of this final report is to summarise, after a brief description of the devices and structures considered, the most important results and conclusions of the numerical analyses carried out by Italy. For more detailed information, especially as far as the execution of the tests and the implementation of the numerical models are concerned, please refer to the technical reports presented by Italy to the Research Coordination Meetings (RCMs). (author)

Genotypic and phenotypic diversity of Ralstonia pickettii and Ralstonia insidiosa isolates from clinical and environmental sources including High-purity Water.

LENUS (Irish Health Repository)

Ryan, Michael P

2011-08-30

Abstract Background Ralstonia pickettii is a nosocomial infectious agent and a significant industrial contaminant. It has been found in many different environments including clinical situations, soil and industrial High Purity Water. This study compares the phenotypic and genotypic diversity of a selection of strains of Ralstonia collected from a variety of sources. Results Ralstonia isolates (fifty-nine) from clinical, industrial and environmental origins were compared genotypically using i) Species-specific-PCR, ii) PCR and sequencing of the 16S-23S rRNA Interspatial region (ISR) iii) the fliC gene genes, iv) RAPD and BOX-PCR and v) phenotypically using biochemical testing. The species specific-PCR identified fifteen out of fifty-nine designated R. pickettii isolates as actually being the closely related species R. insidiosa. PCR-ribotyping of the 16S-23S rRNA ISR indicated few major differences between the isolates. Analysis of all isolates demonstrated different banding patterns for both the RAPD and BOX primers however these were found not to vary significantly. Conclusions R. pickettii species isolated from wide geographic and environmental sources appear to be reasonably homogenous based on genotypic and phenotypic characteristics. R. insidiosa can at present only be distinguished from R. pickettii using species specific PCR. R. pickettii and R. insidiosa isolates do not differ significantly phenotypically or genotypically based on environmental or geographical origin.

Genetic Variability of Beauveria bassiana and a DNA Marker for Environmental Monitoring of a Highly Virulent Isolate Against Cosmopolites sordidus.

Science.gov (United States)

Ferri, D V; Munhoz, C F; Neves, P M O; Ferracin, L M; Sartori, D; Vieira, M L C; Fungaro, M H P

2012-12-01

The banana weevil Cosmopolites sordidus (Germar) is one of a number of pests that attack banana crops. The use of the entomopathogenic fungus Beauveria bassiana as a biological control agent for this pest may contribute towards reducing the application of chemical insecticides on banana crops. In this study, the genetic variability of a collection of Brazilian isolates of B. bassiana was evaluated. Samples were obtained from various geographic regions of Brazil, and from different hosts of the Curculionidae family. Based on the DNA fingerprints generated by RAPD and AFLP, we found that 92 and 88 % of the loci were polymorphic, respectively. The B. bassiana isolates were attributed to two genotypic clusters based on the RAPD data, and to three genotypic clusters, when analyzed with AFLP. The nucleotide sequences of nuclear ribosomal DNA intergenic spacers confirmed that all isolates are in fact B. bassiana. Analysis of molecular variance showed that variability among the isolates was not correlated with geographic origin or hosts. A RAPD-specific marker for isolate CG 1024, which is highly virulent to C. sordidus, was cloned and sequenced. Based on the sequences obtained, specific PCR primers BbasCG1024F (5'-TGC GGC TGA GGA GGA CT-3') and BbasCG1024R (5'-TGC GGC TGA GTG TAG AAC-3') were designed for detecting and monitoring this isolate in the field.

Evolutionary genetics of highly pathogenic H5N1 avian influenza viruses isolated from whooper swans in northern Japan in 2008.

Science.gov (United States)

Usui, Tatsufumi; Yamaguchi, Tsuyoshi; Ito, Hiroshi; Ozaki, Hiroichi; Murase, Toshiyuki; Ito, Toshihiro

2009-12-01

In April and May 2008, highly pathogenic avian influenza viruses subtype H5N1 were isolated from dead or moribund whooper swans in Aomori, Akita and Hokkaido prefectures in northern Japan. To trace the genetic lineage of the isolates, the nucleotide sequences of all eight genes were determined and phylogenetically analyzed. The Japanese strains were nearly identical to chicken viruses isolated in Russia in April 2008 and closely related to viruses isolated from dead wild birds in Hong Kong in 2007-2008. Their HA genes clustered in clade 2.3.2. On the other hand, NA and the other internal genes were closely related to those of clade 2.3.4 viruses (genotype V) whose NP genes originated from an HA clade 2.3.2 virus. In conclusion, the H5N1 viruses isolated in Japan, Russia and Hong Kong were derived from a common ancestor virus belonging to genotype V that was generated from genetic reassortment events between viruses of HA clades 2.3.2 and 2.3.4.

BWR reactor water cleanup system flexible wedge gate isolation valve qualification and high energy flow interruption test

International Nuclear Information System (INIS)

DeWall, K.G.; Steele, R. Jr.

1989-10-01

This report presents the results of research performed to develop technical insights for the NRC effort regarding Generic Issue 87, ''Failure of HPCI Steam Line Without Isolation.'' Volume III of this report contains the data and findings from the original research performed to assess the qualification of the valves and reported in EGG-SSRE-7387, ''Qualification of Valve Assemblies in High Energy BWR Systems Penetrating Containment.'' We present the original work here to complete the documentation trail. The recommendations contained in Volume III of this report resulted in the test program described in Volume I and II. The research began with a survey to characterize the population of normally open containment isolation valves in those process lines that connect to the primary system and penetrate containment. The qualification methodology used by the various manufacturers identified in the survey is reviewed and deficiencies in that methodology are identified. Recommendations for expanding the qualification of valve assemblies for high energy pipe break conditions are presented. 11 refs., 1 fig., 2 tabs

Isolating GaSb Membranes Grown Metamorphically on GaAs Substrates Using Highly Selective Substrate Removal Etch Processes

Science.gov (United States)

Renteria, E. J.; Muniz, A. J.; Addamane, S. J.; Shima, D. M.; Hains, C. P.; Balakrishnan, G.

2015-05-01

The etch rates of NH4OH:H2O2 and C6H8O7:H2O2 for GaAs and GaSb have been investigated to develop a selective etch for GaAs substrates and to isolate GaSb epilayers grown on GaAs. The NH4OH:H2O2 solution has a greater etch rate differential for the GaSb/GaAs material system than C6H8O7:H2O2 solution. The selectivity of NH4OH:H2O2 for GaAs/GaSb under optimized etch conditions has been observed to be as high as 11,000 ± 2000, whereas that of C6H8O7:H2O2 has been measured up to 143 ± 2. The etch contrast has been verified by isolating 2- μm-thick GaSb epilayers that were grown on GaAs substrates. GaSb membranes were tested and characterized with high- resolution x-ray diffraction and atomic force microscopy.

Isolated elliptically polarized attosecond soft X-ray with high-brilliance using polarization gating of harmonics from relativistic plasmas at oblique incidence.

Science.gov (United States)

Chen, Zi-Yu; Li, Xiao-Ya; Li, Bo-Yuan; Chen, Min; Liu, Feng

2018-02-19

The production of intense isolated attosecond pulse is a major goal in ultrafast research. Recent advances in high harmonic generation from relativistic plasma mirrors under oblique incidence interactions gave rise to photon-rich attosecond pulses with circular or elliptical polarization. However, to achieve an isolated elliptical attosecond pulse via polarization gating using currently available long driving pulses remains a challenge, because polarization gating of high harmonics from relativistic plasmas is assumed only possible at normal or near-normal incidence. Here we numerically demonstrate a scheme around this problem. We show that via control of plasma dynamics by managing laser polarization, it is possible to gate an intense single attosecond pulse with high ellipticity extending to the soft X-ray regime at oblique incidence. This approach thus paves the way towards a powerful tool enabling high-time-resolution probe of dynamics of chiral systems and magnetic materials with current laser technology.

Isolation and Characterization of Antithrombin Peptides from the ...

African Journals Online (AJOL)

Purpose: To isolate and characterize the antithrombin compounds of Malaysian leeches' saliva collection (LSC) for use as anticoagulant proteins and peptides. Method: Reversed phase - high performance liquid chromatography (RP-HPLC) was used to isolate all proteins from LSC. All isolated proteins were tested for ...

Process optimization of a deep trench isolation structure for high voltage SOI devices

International Nuclear Information System (INIS)

Zhu Kuiying; Qian Qinsong; Zhu Jing; Sun Weifeng

2010-01-01

The process reasons for weak point formation of the deep trench on SOI wafers have been analyzed in detail. An optimized trench process is also proposed. It is found that there are two main reasons: one is over-etching laterally of the silicon on the surface of the buried oxide caused by a fringe effect; and the other is the slow growth rate of the isolation oxide in the concave silicon corner of the trench bottom. In order to improve the isolation performance of the deep trench, two feasible ways for optimizing the trench process are proposed. The improved process thickens the isolation oxide and rounds sharp silicon corners at their weak points, increasing the applied voltage by 15-20 V at the same leakage current. The proposed new trench isolation process has been verified in the foundry's 0.5-μm HV SOI technology. (semiconductor devices)

Low reproductive isolation and highly variable levels of gene flow reveal limited progress towards speciation between European river and brook lampreys.

Science.gov (United States)

Rougemont, Q; Gaigher, A; Lasne, E; Côte, J; Coke, M; Besnard, A-L; Launey, S; Evanno, G

2015-12-01

Ecologically based divergent selection is a factor that could drive reproductive isolation even in the presence of gene flow. Population pairs arrayed along a continuum of divergence provide a good opportunity to address this issue. Here, we used a combination of mating trials, experimental crosses and population genetic analyses to investigate the evolution of reproductive isolation between two closely related species of lampreys with distinct life histories. We used microsatellite markers to genotype over 1000 individuals of the migratory parasitic river lamprey (Lampetra fluviatilis) and freshwater-resident nonparasitic brook lamprey (Lampetra planeri) distributed in 10 sympatric and parapatric population pairs in France. Mating trials, parentage analyses and artificial fertilizations demonstrated a low level of reproductive isolation between species even though size-assortative mating may contribute to isolation. Most parapatric population pairs were strongly differentiated due to the joint effects of geographic distance and barriers to migration. In contrast, we found variable levels of gene flow between sympatric populations ranging from panmixia to moderate differentiation, which indicates a gradient of divergence with some population pairs that may correspond to alternative morphs or ecotypes of a single species and others that remain partially isolated. Ecologically based divergent selection may explain these variable levels of divergence among sympatric population pairs, but incomplete genome swamping following secondary contact could have also played a role. Overall, this study illustrates how highly differentiated phenotypes can be maintained despite high levels of gene flow that limit the progress towards speciation. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Plutonium interaction with a bacterial strain isolated from the waste isolation pilot plant (WIPP) environment

International Nuclear Information System (INIS)

Strietelmeier, B.A.; Kraus, S.M.; Leonard, P.A.; Triay, I.R.

1996-01-01

This work was conducted as part of a series of experiments to determine the association and interaction of various actinides with bacteria isolated from the WIPP site. The majority of bacteria that exist at the site are expected to be halophiles, or extreme halophiles, due to the high concentration of salt minerals at the location. Experiments were conducted to determine the toxicity of plutonium-n-239, neptunium-237 and americium-243 to several species of these halophiles and the results were reported elsewhere. As an extension of these experiments, we report an investigation of the type of association that occurs between 239 Pu and the isolate WIPP-1A, isolated by staff at Brookhaven National Laboratory, when grown in a high-salt, defined medium. Using scanning electron microscopy (SEM) techniques, we demonstrate a surface association of the 239 Pu with the bacterial cells

Genetic isolation and morphological divergence mediated by high-energy rapids in two cichlid genera from the lower Congo rapids

Directory of Open Access Journals (Sweden)

Stiassny Melanie LJ

2010-05-01

Full Text Available Abstract Background It is hypothesized that one of the mechanisms promoting diversification in cichlid fishes in the African Great Lakes has been the well-documented pattern of philopatry along shoreline habitats leading to high levels of genetic isolation among populations. However lake habitats are not the only centers of cichlid biodiversity - certain African rivers also contain large numbers of narrowly endemic species. Patterns of isolation and divergence in these systems have tended to be overlooked and are not well understood. Results We examined genetic and morphological divergence among populations of two narrowly endemic cichlid species, Teleogramma depressum and Lamprologus tigripictilis, from a 100 km stretch of the lower Congo River using both nDNA microsatellites and mtDNA markers along with coordinate-based morphological techniques. In L. tigripictilis, the strongest genetic break was concordant with measurable phenotypic divergence but no morphological disjunction was detected for T. depressum despite significant differentiation at mtDNA and nDNA microsatellite markers. Conclusions The genetic markers revealed patterns of philopatry and estimates of genetic isolation that are among the highest reported for any African cichlid species over a comparable geographic scale. We hypothesize that the high levels of philopatry observed are generated and maintained by the extreme hydrology of the lower Congo River.

A SEISMIC DESIGN OF NUCLEAR REACTOR BUILDING STRUCTURES APPLYING SEISMIC ISOLATION SYSTEM IN A HIGH SEISMICITY REGION –A FEASIBILITY CASE STUDY IN JAPAN-

Directory of Open Access Journals (Sweden)

TETSUO KUBO

2014-10-01

Full Text Available A feasibility study on the seismic design of nuclear reactor buildings with application of a seismic isolation system is introduced. After the Hyogo-ken Nanbu earthquake in Japan of 1995, seismic isolation technologies have been widely employed for commercial buildings. Having become a mature technology, seismic isolation systems can be applied to NPP facilities in areas of high seismicity. Two reactor buildings are discussed, representing the PWR and BWR buildings in Japan, and the application of seismic isolation systems is discussed. The isolation system employing rubber bearings with a lead plug positioned (LRB is examined. Through a series of seismic response analyses using the so-named standard design earthquake motions covering the design basis earthquake motions obtained for NPP sites in Japan, the responses of the seismic isolated reactor buildings are evaluated. It is revealed that for the building structures examined herein: (1 the responses of both isolated buildings and isolating LRBs fulfill the specified design criteria; (2 the responses obtained for the isolating LRBs first reach the ultimate condition when intensity of motion is 2.0 to 2.5 times as large as that of the design-basis; and (3 the responses of isolated reactor building fall below the range of the prescribed criteria.

Observation of Single Isolated Electrons of High Transverse Momentum in Events with Missing Transverse Energy at the CERN pp Collider

DEFF Research Database (Denmark)

Banner, M.; Kofoed-Hansen, O.

1983-01-01

We report the results of a search for single isolated electrons of high transverse momentum at the CERN collider. Above 15 GeV/c, four events are found having large missing transverse energy along a direction opposite in azimuth to that of the high-pT electron. Both the configuration of the events...

Molecular characterization of Mycobacterium tuberculosis isolates from Tanga, Tanzania: First insight of MIRU-VNTR and microarray-based spoligotyping in a high burden country.

Science.gov (United States)

Hoza, Abubakar S; Mfinanga, Sayoki G; Moser, Irmgard; König, Brigitte

2016-05-01

Molecular typing of Mycobacterium tuberculosis(MTB) has greatly enhanced the understanding of the population structure of MTB isolates and epidemiology of tuberculosis (TB). To characterize prevalent genotypes of MTB, microarrays‑based spoligotyping and mycobacterial interspersed repetitive unit‑variable number of tandem repeats (MIRU‑VNTR) were applied on 80 isolates collected from primary health care facilities in Tanga, North‑eastern Tanzania. A total of 18 distinct spoligotypes were identified. The lineages by order of their predominance were EAI and CAS families (26.25%, 21 isolates each), LAM family and T super‑family (10%, 8 isolates each), MANU family (3.75%, 3 isolates), Beijing family (2.5%, 2 isolates) and S family (1.25%, 1 isolate). Overall, sixteen (20%) strains could not be allocated to any lineage according to the SITVIT_WEB database. The allelic diversity (h) for specific MIRU‑VNTR loci showed a considerable variation ranging from 0.826 of VNTR locus 3192 to 0.141 of VNTR locus 2059. The allelic diversity for 11 loci (VNTR 3192, 2996, 2165, 960, 4052, 424, 4156, 2531, 1644, 802 and 3690) exceeded 0.6, indicating highly discriminatory power. Seven loci (VNTR 2163b, 2401, 1955, 577, 4348, 2687 and 580) showed moderate discrimination (0.3 ≤ h ≥ 0.6), and three loci (VNTR3007, 154 and 2059) were less polymorphic. The present study suggests that the TB cases in Tanga might be caused by a diverse array of MTB strain families that may be indicative of a cosmopolitan population with frequent migration and travel. Microarray‑based spoligotyping and MIRU‑VNTR could be reliable tools in detecting different MTB genotypes in high burden settings. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Isolation and identification of cow-origin Cryptosporidium isolates in Hefei].

Science.gov (United States)

Sun, Tao; Liu, Wei; Wang, Ju-Hua; Xue, Xiu-Heng; Zhao, Chang-Cheng; Li, Pei-Ying

2011-12-01

To isolate cow-origin Cryptosporidium in Hefei, and identify its species. 285 dairy cattle fecal samples collected from a farm in Hefei were examined by using floating saturated solution of sucrose and modified acid-fast staining. Cryptosporidium oocysts were isolated and purified from positive fecal samples. Genetic DNA was extracted to be the template. According to the sequence of 18S rRNA gene and HSP70 gene from Cryptosporidium sp., the primers were designed and synthesized. The PCR products were amplified by PCR and nested-PCR. The nested PCR products were cloned and sequenced. Homology searches and phylogenic tree construction were done by DNAStar software. Five fecal samples were positive by morphological methods with an infection rate of 1.8% (5/285). Oocysts from the 5 positive fecal samples were elliptical or ovoid detected by using floating saturated solution of sucrose and modified acid-fast staining with the size of 7.37 microm x 6.13 microm and 7.58 microm x 6.20 microm, and a shape index of 1.20 and 1.22, respectively. Nested-PCR resulted in a 18S rRNA and HSP70 gene fragments with approximately 250 bp and 325 bp, respectively. The five isolates showed a high level of nucleic acid identity with sequence data of the 18S rRNA gene of Cryptosporidium andersoni (DQ989573), and they were clustered in the same clade. The highest HSP70 gene sequence identity was found among the five isolates and other reported C. andersoni isolates (AY954892 and DQ989576), and they were placed into the same clade. The cow-origin Cryptosporidium isolates derived from Hefei is Cryptosporidium andersoni.

Recent advances in micro-vibration isolation

Science.gov (United States)

Liu, Chunchuan; Jing, Xingjian; Daley, Steve; Li, Fengming

2015-05-01

Micro-vibration caused by disturbance sources onboard spacecraft can severely degrade the working environment of sensitive payloads. Some notable vibration control methods have been developed particularly for the suppression or isolation of micro-vibration over recent decades. Usually, passive isolation techniques are deployed in aerospace engineering. Active isolators, however, are often proposed to deal with the low frequency vibration that is common in spacecraft. Active/passive hybrid isolation has also been effectively used in some spacecraft structures for a number of years. In semi-active isolation systems, the inherent structural performance can be adjusted to deal with variation in the aerospace environment. This latter approach is potentially one of the most practical isolation techniques for micro-vibration isolation tasks. Some emerging advanced vibration isolation methods that exploit the benefits of nonlinearity have also been reported in the literature. This represents an interesting and highly promising approach for solving some challenging problems in the area. This paper serves as a state-of-the-art review of the vibration isolation theory and/or methods which were developed, mainly over the last decade, specifically for or potentially could be used for, micro-vibration control.

Enhanced discrimination of highly clonal ST22-methicillin-resistant Staphylococcus aureus IV isolates achieved by combining spa, dru, and pulsed-field gel electrophoresis typing data.

LENUS (Irish Health Repository)

Shore, Anna C

2010-05-01

ST22-methicillin-resistant Staphylococcus aureus type IV (ST22-MRSA-IV) is endemic in Irish hospitals and is designated antibiogram-resistogram type-pulsed-field group (AR-PFG) 06-01. Isolates of this highly clonal strain exhibit limited numbers of pulsed-field gel electrophoresis (PFGE) patterns and spa types. This study investigated whether combining PFGE and spa typing with DNA sequencing of the staphylococcal cassette chromosome mec element (SCCmec)-associated direct repeat unit (dru typing) would improve isolate discrimination. A total of 173 MRSA isolates recovered in one Irish hospital during periods in 2007 and 2008 were investigated using antibiogram-resistogram (AR), PFGE, spa, dru, and SCCmec typing. Isolates representative of each of the 17 pulsed-field group 01 (PFG-01) spa types identified underwent multilocus sequence typing, and all isolates were ST22. Ninety-seven percent of isolates (168 of 173) exhibited AR-PFG 06-01 or closely related AR patterns, and 163 of these isolates harbored SCCmec type IVh. The combination of PFGE, spa, and dru typing methods significantly improved discrimination of the 168 PFG-01 isolates, yielding 65 type combinations with a Simpson\\'s index of diversity (SID) of 96.53, compared to (i) pairwise combinations of spa and dru typing, spa and PFGE typing, and dru and PFGE typing, which yielded 37, 44, and 43 type combinations with SIDs of 90.84, 91.00, and 93.57, respectively, or (ii) individual spa, dru, and PFGE typing methods, which yielded 17, 17, and 21 types with SIDs of 66.9, 77.83, and 81.34, respectively. Analysis of epidemiological information for a subset of PFG-01 isolates validated the relationships inferred using combined PFGE, spa, and dru typing data. This approach significantly enhances discrimination of ST22-MRSA-IV isolates and could be applied to epidemiological investigations of other highly clonal MRSA strains.

High-order harmonic generation spectra and isolated attosecond pulse generation with a two-color time delayed pulse

International Nuclear Information System (INIS)

Feng Liqiang; Chu Tianshu

2012-01-01

Highlights: ► Investigation of HHG spectra and single isolated attosecond pulse generation. ► Irradiation from a model Ne atom by two-color time delayed pulse. ► Observation of time delay effect and relative phase effect. ► Revelation of the optimal condition for generating isolated attosecond pulse. ► Generation of a single isolated attosecond pulse of 45as. - Abstract: In this paper, we theoretically investigate the delay time effect on the high-order harmonic generation (HHG) when a model Ne atom is exposed to a two-color time delayed pulse, consisting of a 5fs/800 nm fundamental field and a 20fs/2000 nm controlling field. It shows that the HHG spectra are strongly sensitive to the delay time between the two laser fields, in particular, for the zero carrier-envelope phase (CEP) φ case (corresponding to the 800 nm fundamental field), the maximum cutoff energy has been achieved at zero delay time. However, with the introduction of the CEP (φ = 180°), the delay effect on HHG is changed, exhibiting a ‘U’ structure harmonic emission from −1 T to 1 T. In addition, the combinations of different controlling pulse frequencies and pulse intensities have also been considered, showing the similar results as the original controlling field case, but with some characteristics. Finally, by properly superposing the optimal harmonic spectrum, an isolated 45as pulse is generated without phase compensation.

Measuring protected-area isolation and correlations of isolation with land-use intensity and protection status.

Science.gov (United States)

Seiferling, Ian S; Proulx, Raphaël; Peres-Neto, Pedro R; Fahrig, Lenore; Messier, Christian

2012-08-01

Protected areas cover over 12% of the terrestrial surface of Earth, and yet many fail to protect species and ecological processes as originally envisioned. Results of recent studies suggest that a critical reason for this failure is an increasing contrast between the protected lands and the surrounding matrix of often highly altered land cover. We measured the isolation of 114 protected areas distributed worldwide by comparing vegetation-cover heterogeneity inside protected areas with heterogeneity outside the protected areas. We quantified heterogeneity as the contagion of greenness on the basis of NDVI (normalized difference vegetation index) values, for which a higher value of contagion indicates less heterogeneous land cover. We then measured isolation as the difference between mean contagion inside the protected area and mean contagion in 3 buffer areas of increasing distance from the protected-area border. The isolation of protected areas was significantly positive in 110 of the 114 areas, indicating that vegetation cover was consistently more heterogeneous 10-20 km outside protected areas than inside their borders. Unlike previous researchers, we found that protected areas in which low levels of human activity are allowed were more isolated than areas in which high levels are allowed. Our method is a novel way to assess the isolation of protected areas in different environmental contexts and regions. ©2011 Society for Conservation Biology.

The requirement for freshly isolated human colorectal cancer (CRC) cells in isolating CRC stem cells.

Science.gov (United States)

Fan, F; Bellister, S; Lu, J; Ye, X; Boulbes, D R; Tozzi, F; Sceusi, E; Kopetz, S; Tian, F; Xia, L; Zhou, Y; Bhattacharya, R; Ellis, L M

2015-02-03

Isolation of colorectal cancer (CRC) cell populations enriched for cancer stem cells (CSCs) may facilitate target identification. There is no consensus regarding the best methods for isolating CRC stem cells (CRC-SCs). We determined the suitability of various cellular models and various stem cell markers for the isolation of CRC-SCs. Established human CRC cell lines, established CRC cell lines passaged through mice, patient-derived xenograft (PDX)-derived cells, early passage/newly established cell lines, and cells directly from clinical specimens were studied. Cells were FAC-sorted for the CRC-SC markers CD44, CD133, and aldehyde dehydrogenase (ALDH). Sphere formation and in vivo tumorigenicity studies were used to validate CRC-SC enrichment. None of the markers studied in established cell lines, grown either in vitro or in vivo, consistently enriched for CRC-SCs. In the three other cellular models, CD44 and CD133 did not reliably enrich for stemness. In contrast, freshly isolated PDX-derived cells or early passage/newly established CRC cell lines with high ALDH activity formed spheres in vitro and enhanced tumorigenicity in vivo, whereas cells with low ALDH activity did not. PDX-derived cells, early passages/newly established CRC cell lines and cells from clinical specimen with high ALDH activity can be used to identify CRC-SC-enriched populations. Established CRC cell lines should not be used to isolate CSCs.

Tiamulin resistance in porcine Brachyspira pilosicoli isolates.

Science.gov (United States)

Pringle, M; Landén, A; Franklin, A

2006-02-01

There are few studies on antimicrobial susceptibility of Brachyspira pilosicoli, therefore this study was performed to investigate the situation among isolates from pigs. The tiamulin and tylosin susceptibility was determined by broth dilution for 93 and 86 porcine B. pilosicoli isolates, respectively. The isolates came from clinical samples taken in Swedish pig herds during the years 2002 and 2003. The tylosin minimal inhibitory concentration (MIC) was >16 microg/ml for 50% (n=43) of the isolates tested. A tiamulin MIC >2 microg/ml was obtained for 14% (n=13) of the isolates and these were also tested against doxycycline, salinomycin, valnemulin, lincomycin and aivlosin. For these isolates the susceptibility to salinomycin and doxycycline was high but the MICs for aivlosin varied. The relationship between the 13 tiamulin resistant isolates was analyzed by pulsed-field gel electrophoresis (PFGE). Among the 13 isolates 10 different PFGE patterns were identified.

Biosorption of cadmium by Brevundimonas sp. ZF12 strain, a novel biosorbent isolated from hot-spring waters in high background radiation areas

International Nuclear Information System (INIS)

Masoudzadeh, Nasrin; Zakeri, Fardideh; Lotfabad, Tayebe bagheri; Sharafi, Hakimeh; Masoomi, Fatemeh; Zahiri, Hoseein Shahbani; Ahmadian, Gholamreza; Noghabi, Kambiz Akbari

2011-01-01

Highlights: ► Isolation and characterization of a novel cadmium-biosorbent (Brevundimonas sp. ZF12) from high background radiation areas. ► Brevundimonas sp. ZF12 caused 50% removal of cadmium at the concentration level of 250 ppm. ► Solution pH values used for the reusability study have powerful desorptive features to recover Cd ions sorbed onto the biomass. ► This is the first study carried out so far for the cadmium removal from aqueous solutions by a novel biosorbent Brevundimonas sp. ZF12. ► In our opinion, the isolate can be an attractive alternative to remove the cadmium-containing wastewaters. - Abstract: The aim of this study is to screen cadmium biosorbing bacterial strains isolated from soils and hot-springs containing high concentrations of radium ( 226 Ra) in Ramsar using a batch system. Brevundimonas sp. ZF12 strain isolated from the water with high 226 Ra content caused 50% removal of cadmium at a concentration level of 250 ppm. The biosorption equilibrium data are fitted well by the Langmuir adsorption isotherm and kinetic studies indicated that the biosorption follows pseudo second-order model. The effect of different physico-chemical parameters like biomass concentration, pH, cadmium concentration, temperature and contact time on cadmium sorption was also investigated using FTIR, SEM and XRD analytical techniques. A high desorption efficiency (above 90%) was obtained using a pH range of 2.0–4.0. Reusability of the biomass was examined under consecutive biosorption–desorption cycles repeated thrice. In conclusion, Brevundimonas sp. ZF12 is proposed as an excellent cadmium biosorbent that may have important applications in Cd removal from wastewaters.

Serratia sp. ZF03: an efficient radium biosorbent isolated from hot-spring waters in high background radiation areas.

Science.gov (United States)

Zakeri, Farideh; Noghabi, Kambiz Akbari; Sadeghizadeh, Majid; Kardan, Mohammad Reza; Masoomi, Fatemeh; Farshidpour, Mohammad Reza; Atarilar, Ali

2010-12-01

The aim of this study is to isolate and characterize (226)Ra biosorbing indigenous bacterial strains from soils and hot-springs containing high concentrations of (226)Ra by using biochemical and molecular approaches. Fifteen bacteria were isolated and their phylogenetic affiliations were determined based on their 16S rRNA gene and the two most relevant hypervariable regions of this gene; V3 and V6 analysis. A pigmented Serratia sp. ZF03 strain isolated from the water with (226)Ra content of 50471 mBq l(-1), caused 70% removal of (226)Ra at a radioactivity level of 50 Bq ml(-1), after 5 min and 75-80% in equilibrium time of 1 h, depending on the particular biosorption system and experimental conditions studied. The biosorption equilibrium was described by Langmuir and Freundlich isotherm models. Kinetic studies indicated that the biosorption follows pseudo-second-order kinetics. Effect of different physico-chemical parameters on (226)Ra sorption, FTIR, SEM and TEM analysis were also investigated. 2010 Elsevier Ltd. All rights reserved.

Isolation and characterization of virus of highly pathogenic avian influenza H5 subtype of chicken from outbreaks in Indonesia

Directory of Open Access Journals (Sweden)

Agus Wiyono

2004-03-01

Full Text Available A study on the isolation and characterization of Highly Pathogenic Avian Influenza of chicken from outbreaks in Indonesia was conducted at Indonesian Research Institute for Veterinary Science. Outbreaks of avian disease had been reported in Indonesia since August 2003 affecting commercial layer, broiler, quail, and ostrich and also native chicken with showing clinical signs such as cyanosis of wattle and comb, nasal discharges and hypersalivation, subcutaneous ptechiae on foot and leg, diarre and sudden high mortality. The aim of this study is to isolate and characterize the causal agent of the disease. Samples of serum, feather follicle, tracheal swab, as well as organs of proventriculus, intestine, caecal tonsil, trachea and lungs were collected from infected animals. Serum samples were tested haemaglutination/haemaglutination inhibition to Newcastle Disease and Egg Drop Syndrome viruses. Isolation of virus of the causal agent of the outbreak was conducted from samples of feather follicle, tracheal swab, and organs using 11 days old specific pathogen free (SPF embryonated eggs. The isolated viruses were then characterised by agar gel precipitation test using swine influenza reference antisera, by haemaglutination inhibition using H1 to H15 reference antisera, and by electron microscope examination. The pathogenicity of the viruses was confirmed by intravenous pathogenicity index test and its culture in Chicken Embryo Fibroblast primary cell culture without addition of trypsin. The study revealed that the causative agent of the outbreaks of avian disease in Indonesia was avian influenza H5 subtype virus based upon serological tests, virus isolation and characterization using swine influenza reference antisera, and electron microscope examination. While subtyping of the viruses using H1 to H15 reference antisera suggested that the virus is very likely to be an avian influenza H5N1 subtype virus. The pathogenicity test confirmed that the viruses

Ultra-High Pressure Homogenization enhances physicochemical properties of soy protein isolate-stabilized emulsions.

Science.gov (United States)

Fernández-Ávila, C; Escriu, R; Trujillo, A J

2015-09-01

The effect of Ultra-High Pressure Homogenization (UHPH, 100-300MPa) on the physicochemical properties of oil-in-water emulsions prepared with 4.0% (w/v) of soy protein isolate (SPI) and soybean oil (10 and 20%, v/v) was studied and compared to emulsions treated by conventional homogenization (CH, 15MPa). CH emulsions were prepared with non-heated and heated (95°C for 15min) SPI dispersions. Emulsions were characterized by particle size determination with laser diffraction, rheological properties using a rotational rheometer by applying measurements of flow curve and by transmission electron microscopy. The variation on particle size and creaming was assessed by Turbiscan® analysis, and visual observation of the emulsions was also carried out. UHPH emulsions showed much smaller d 3.2 values and greater physical stability than CH emulsions. The thermal treatment of SPI prior CH process did not improve physical stability properties. In addition, emulsions containing 20% of oil exhibited greater physical stability compared to emulsions containing 10% of oil. Particularly, UHPH emulsions treated at 100 and 200MPa with 20% of oil were the most stable due to low particle size values (d 3.2 and Span), greater viscosity and partial protein denaturation. These results address the physical stability improvement of protein isolate-stabilized emulsions by using the emerging UHPH technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Different Babesia canis isolates, different diseases.

Science.gov (United States)

Schetters, T P; Moubri, K; Précigout, E; Kleuskens, J; Scholtes, N C; Gorenflot, A

1997-11-01

Using surface immunofluorescence isolate-specific antigens were detected on the membrane of erythrocytes infected with Babesia parasites. In addition, the strains reacted differently with Plasmagel in that the European isolate (B.c. canis) could be purified on Plasmagel effectively, whereas infected erythrocytes of the South-African isolate (B.c. rossi) could not. Experimental infection of dogs with Babesia canis isolates from geographically different areas revealed different pathology. The European isolate obtained from France exhibited transient parasitaemia, usually below 1%, associated with low PCV values and congestion of internal organs. Clinical disease was correlated with an effect on the coagulation system, and not with peripheral parasitaemia. Infection of dogs with South-African-derived isolate induced high parasitaemia usually much higher than 1%, which required chemotherapeutic treatment. In these animals clinical disease was correlated with peripheral parasitaemia and not with parameters of the coagulation system. The results show that the etiology of disease caused by these isolates of B.c. canis and B.c. rossi is different. This might have implications for the development of vaccines against these infections.

ISOLATION OF GLYCOSIDES FROM THE BARKS OF ILEX ROTUNDA BY HIGH-SPEED COUNTER-CURRENT CHROMATOGRAPHY

OpenAIRE

Wang, Chun; Chao, Zhimao; Sun, Wen; Wu, Xiaoyi; Ito, Yoichiro

2013-01-01

Semi-preparative and preparative high-speed counter-current chromatography (HSCCC) were successfully used for isolation of glycosides from 50% ethanol extract of the dried barks of Ilex rotunda Thunb. (Aquifoliaceae) by using a two-phase solvent system composed of ethyl acetate-n-butanol-water (1:6:7, v/v/v). From 1.0 g of the extract, syringaresinol 4',4"-di-o-β-d-glucopyranoside (I, 20.2 mg),, syringin (II, 56.8 mg), sinapaldehyde glucoside (III, 26.2 mg),, syringaresinol 4'-o-β-d-glucopyra...

Seismic isolation structure for pool-type LMFBR - isolation building with vertically isolated floor for NSSS

International Nuclear Information System (INIS)

Sakurai, A.; Shiojiri, H.; Aoyagi, S.; Matsuda, T.; Fujimoto, S.; Sasaki, Y.; Hirayama, H.

1987-01-01

The NSSS isolation floor vibration characteristics were made clear. Especially, the side support bearing (rubber bearing) is effective for horizontal floor motion restraint and rocking motion control. Seismic isolation effects for responses of the reactor components can be sufficiently expected, using the vertical seismic isolation floor. From the analytical and experimental studies, the following has been concluded: (1) Seismic isolation structure, which is suitable for large pool-type LMFBR, were proposed. (2) Seismic response characteristics of the seismic isolation structure were investigated. It was made clear that the proposed seismic isolation (Combination of the isolated building and the isolated NSSS floor) was effective. (orig./HP)

Magnetic Quasi-Phase Matching All-Fiber Isolator

Directory of Open Access Journals (Sweden)

Chunte A. Lu

2010-01-01

Full Text Available We have experimentally demonstrated an all-fiber optical isolator with 20 dB isolation. The result shows that the quasi-phase matching technique via a meter-long magnet array is highly feasible to generate more than 45 degrees of Faraday rotation in the fibers. The all-fiber isolator can also be temperature tuned to operate between 1048 nm and 1066 nm wavelength.

Enhancing pesticide degradation using indigenous microorganisms isolated under high pesticide load in bioremediation systems with vermicomposts.

Science.gov (United States)

Castillo Diaz, Jean Manuel; Delgado-Moreno, Laura; Núñez, Rafael; Nogales, Rogelio; Romero, Esperanza

2016-08-01

In biobed bioremediation systems (BBSs) with vermicomposts exposed to a high load of pesticides, 6 bacteria and 4 fungus strains were isolated, identified, and investigated to enhance the removal of pesticides. Three different mixtures of BBSs composed of vermicomposts made from greenhouse (GM), olive-mill (OM) and winery (WM) wastes were contaminated, inoculated, and incubated for one month (GMI, OMI and WMI). The inoculums maintenance was evaluated by DGGE and Q-PCR. Pesticides were monitored by HPLC-DAD. The highest bacterial and fungal abundance was observed in WMI and OMI respectively. In WMI, the consortia improved the removal of tebuconazole, metalaxyl, and oxyfluorfen by 1.6-, 3.8-, and 7.7-fold, respectively. The dissipation of oxyfluorfen was also accelerated in OMI, with less than 30% remaining after 30d. One metabolite for metalaxyl and 4 for oxyfluorfen were identified by GC-MS. The isolates could be suitable to improve the efficiency of bioremediation systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

Isolation of high-quality DNA in 16 aromatic and medicinal Colombian species using silica-based extraction columns

Directory of Open Access Journals (Sweden)

Vega Vela Nelson Enrique

2011-12-01

Full Text Available

Aromatic and medicinal plant species are a valuable resource for research and development of pharmaceutical, cosmetic, crop protection and nutritional agents, due to the high amount of bioactive phytochemicals that they contain. However, these compounds are a major obstacle in the isolation of high-quality DNA suitable for genetic analyses. In this paper, we report a protocol that optimizes the use of the cationic detergent CTAB and the reductant β-mercaptoethanol in cell lysis. The elimination of plant secondary metabolites such as polysaccharides and polyphenols, that typically co-isolate with DNA, was achieved using the chemical denaturing properties of the guanidinium cation, which together with the adsorbent chemical specificity of the silica, resulted in the purification of high-quality DNA suitable for digestion with restriction enzymes and optimal for PCR amplification of AFLP-type molecular markers. This protocol was evaluated on 16 Colombian aromatic and medicinal plant species promising for their essential oils. The results allow suggesting that this procedure might be appropriate for other species, tissues and sample types recalcitrant to DNA extraction.

Antagonistic Activity of Trichoderma ISolates against Sclerotium rolfsii : Screening of Efficient Isolates from Morocco Soils for Biological Control

Directory of Open Access Journals (Sweden)

N. Khattabi

2004-12-01

Full Text Available Seventy Trichoderma spp. isolates collected from different regions of Morocco were tested for their capacity to inhibit in vitro mycelial growth of Sclerotium rolfsii, and for their effect on the viability of S. rolfsii sclerotia in the soil. The Trichoderma spp. isolates inhibited mycelial growth of S. rolfsii to various degrees, with 52% of isolates expressing an average inhibition, varying between 45 and 55%. The effect on the viability of sclerotia in the soil also varied between isolates of Trichoderma, with the majority (84% having a slight effect. A group of twenty isolates identified as Trichoderma harzianum when tested in sterilized soil, significantly reduced sclerotial viability though not in natural soil. Four of these isolates (Nz, Kb2, Kb3 and Kf1 showed good antagonistic activity against S. rolfsii and were also highly competitive in natural soil. These isolates would therefore be candidates for development in biological control program.

Isolation of thermotolerant, halotolerant, facultative biosurfactant-producing bacteria.

Science.gov (United States)

Ghojavand, H; Vahabzadeh, F; Mehranian, M; Radmehr, M; Shahraki, Kh A; Zolfagharian, F; Emadi, M A; Roayaei, E

2008-10-01

Several facultative bacterial strains tolerant to high temperature and salinity were isolated from the oil reservoir brines of an Iranian oil field (Masjed-I Soleyman). Some of these isolates were able to grow up to 60 degrees C and at high concentration of NaCl (15% w/v). One of the isolates grew at 40 degrees C, while it was able to grow at 15% w/v NaCl. Tolerances to NaCl levels decreased as the growth temperatures were increased. Surfactant production ability was detected in some of these isolates. The use of biosurfactant is considered as an effective mechanism in microbial-enhanced oil recovery processes detected in some of these isolates. The surfactant producers were able to grow at high temperatures and salinities to about 55 degrees C and 10% w/v, respectively. These isolates exhibited morphological and physiological characteristics of the Bacillus genus. The partial sequencing of the 16S ribosomal deoxyribonucleic acid gene of the selected isolates was assigned them to Bacillus subtilis group. The biosurfactant produced by these isolates caused a substantial decrease in the surface tension of the culture media to 26.7 mN/m. By the use of thin-layer chromatography technique, the presence of the three compounds was detected in the tested biosurfactant. Infrared spectroscopy and (1)H nuclear magnetic resonance analysis were used, and the partial structural characterization of the biosurfactant mixture of the three compounds was found to be lipopeptidic in nature. The possibility of use of the selected bacterial strains reported, in the present study, in different sectors of the petroleum industry has been addressed.

Isolated photosystem I reaction centers on a functionalized gated high electron mobility transistor.

Science.gov (United States)

Eliza, Sazia A; Lee, Ida; Tulip, Fahmida S; Mostafa, Salwa; Greenbaum, Elias; Ericson, M Nance; Islam, Syed K

2011-09-01

In oxygenic plants, photons are captured with high quantum efficiency by two specialized reaction centers (RC) called Photosystem I (PS I) and Photosystem II (PS II). The captured photon triggers rapid charge separation and the photon energy is converted into an electrostatic potential across the nanometer-scale (~6 nm) reaction centers. The exogenous photovoltages from a single PS I RC have been previously measured using the technique of Kelvin force probe microscopy (KFM). However, biomolecular photovoltaic applications require two-terminal devices. This paper presents for the first time, a micro-device for detection and characterization of isolated PS I RCs. The device is based on an AlGaN/GaN high electron mobility transistor (HEMT) structure. AlGaN/GaN HEMTs show high current throughputs and greater sensitivity to surface charges compared to other field-effect devices. PS I complexes immobilized on the floating gate of AlGaN/GaN HEMTs resulted in significant changes in the device characteristics under illumination. An analytical model has been developed to estimate the RCs of a major orientation on the functionalized gate surface of the HEMTs. © 2011 IEEE

Isolated Photosystem I Reaction Centers on a Functionalized Gated High Electron Mobility Transistor

Energy Technology Data Exchange (ETDEWEB)

Eliza, Sazia A. [University of Tennessee, Knoxville (UTK); Lee, Ida [ORNL; Tulip, Fahmida S [ORNL; Islam, Syed K [University of Tennessee, Knoxville (UTK); Mostafa, Salwa [University of Tennessee, Knoxville (UTK); Greenbaum, Elias [ORNL; Ericson, Milton Nance [ORNL

2011-01-01

In oxygenic plants, photons are captured with high quantum efficiency by two specialized reaction centers (RC) called Photosystem I (PS I) and Photosystem II (PS II). The captured photon triggers rapid charge separation and the photon energy is converted into an electrostatic potential across the nanometer-scale nm reaction centers. The exogenous photovoltages from a single PS I RC have been previously measured using the technique of Kelvin force probe microscopy (KFM). However, biomolecular photovoltaic applications require two-terminal devices. This paper presents for the first time, a micro-device for detection and characterization of isolated PS I RCs. The device is based on an AlGaN/GaN high electron mobility transistor (HEMT) structure. AlGaN/GaN HEMTs show high current throughputs and greater sensitivity to surface charges compared to other field-effect devices. PS I complexes immobilized on the floating gate of AlGaN/GaN HEMTs resulted in significant changes in the device characteristics under illumination. An analytical model has been developed to estimate the RCs of a major orientation on the functionalized gate surface of the HEMTs.

Pharmacologic management of isolated low high-density lipoprotein syndrome.

Science.gov (United States)

Bermúdez, Valmore; Cano, Raquel; Cano, Clímaco; Bermúdez, Fernando; Arraiz, Nailet; Acosta, Luis; Finol, Freddy; Pabón, María Rebeca; Amell, Anilsa; Reyna, Nadia; Hidalgo, Joaquin; Kendall, Paúl; Manuel, Velasco; Hernández, Rafael

2008-01-01

High-density lipoprotein (HDL) cholesterol is a heterogeneous group of lipoproteins exhibiting a variety of properties like prostacyclin production stimulation, decrease in platelet aggregation, endothelial cell apoptosis inhibition, and low-density lipoprotein oxidation blockade. Epidemiologic studies have shown an inverse relation between HDL cholesterol levels and cardiovascular risk. Low HDL cholesterol is associated with increased risk for myocardial infarction, stroke, sudden death, peripheral artery disease, and postangioplasty restenosis. In contrast, high HDL levels are associated with longevity and protection against atherosclerotic disease development. Given the evolving epidemic of obesity, diabetes mellitus, and metabolic syndrome, the prevalence of low HDL will continue to rise. In the United States, low HDL is present in 35% of men, 15% of women, and approximately 63% of patients with coronary artery disease. Data extracted from the Framingham study highlight that 1-mg increase in HDL levels decreases by 2% to 3% the risk of cardiovascular disease. There is no doubt regarding clinical importance about isolated low HDL, but relatively few clinicians consider a direct therapeutic intervention of this dyslipidemia. In this sense, lifestyle measures should be the first-line strategy to manage low HDL levels. On the other hand, pharmacologic options include niacin, fibrates, and statins. Fibrates appear to reduce risk preferentially in patients with low HDL with metabolic syndrome, whereas statins reduce risk across all levels of HDL. Torcetrapib, a cholesteryl esters transfer protein inhibitor, represented a hope to raise this lipoprotein; however, all clinical trials on this drug had ceased after ILLUMINATE, RADIANCE and ERASE trials had recorded an increase in mortality, rates of myocardial infarction, angina, and heart failure. In the near future, drugs as beta-glucans, Apo-A1 mimetic peptides, and ACAT inhibitors, are the new promises to treat this

Interaction Effect of Social Isolation and High Dose Corticosteroid on Neurogenesis and Emotional Behavior.

Science.gov (United States)

Chan, Jackie N-M; Lee, Jada C-D; Lee, Sylvia S P; Hui, Katy K Y; Chan, Alan H L; Fung, Timothy K-H; Sánchez-Vidaña, Dalinda I; Lau, Benson W-M; Ngai, Shirley P-C

2017-01-01

Hypercortisolemia is one of the clinical features found in depressed patients. This clinical feature has been mimicked in animal studies via application of exogenous corticosterone (CORT). Previous studies suggested that CORT can induce behavioral disturbance in anxious-depressive like behavior, which is associated with suppressed neurogenesis. Hippocampal neurogenesis plays an important role in adult cognitive and behavioral regulation. Its suppression may thus lead to neuropsychiatric disorders. Similar to the effects of CORT on the animals' depression-like behaviors and neurogenesis, social deprivation has been regarded as one factor that predicts poor prognosis in depression. Furthermore, social isolation is regarded as a stressor to social animals including experimental rodents. Hence, this study aims to examine if social isolation would induce further emotional or anxiety-like behavior disturbance and suppress neurogenesis in an experimental model that was repeatedly treated with CORT. Sprague-Dawley rats were used in this study to determine the effects of different housing conditions, either social isolated or group housing, in vehicle-treated control and CORT-treated animals. Forced swimming test (FST), open field test (OFT) and social interaction test (SIT) were used to assess depression-like, anxiety-like and social behaviors respectively. Immunohistochemistry was performed to quantify the number of proliferative cells and immature neurons in the hippocampus, while dendritic maturation of immature neurons was analyzed by Sholl analysis. Social isolation reduced latency to immobility in FST. Furthermore, social isolation could significantly reduce the ratio of doublecortin and bromodeoxyuridine (BrdU) positive cells of the neurogenesis assay under CORT-treated condition. The current findings suggested that the behavioral and neurological effect of social isolation is dependent on the condition of hypercortisolemia. Furthermore, social isolation may

A pooled analysis of the association of isolated low levels of high-density lipoprotein cholesterol with cardiovascular mortality in Japan.

Science.gov (United States)

Hirata, Takumi; Sugiyama, Daisuke; Nagasawa, Shin-Ya; Murakami, Yoshitaka; Saitoh, Shigeyuki; Okayama, Akira; Iso, Hiroyasu; Irie, Fujiko; Sairenchi, Toshimi; Miyamoto, Yoshihiro; Yamada, Michiko; Ishikawa, Shizukiyo; Miura, Katsuyuki; Ueshima, Hirotsugu; Okamura, Tomonori

2017-07-01

Low levels of serum high-density lipoprotein cholesterol (HDL-C) have been shown to be associated with increased risk of coronary heart disease (CHD). However, because this is usually observed in the context of other lipid abnormalities, it is not known whether isolated low serum HDL-C levels are an independent risk factor for CHD. We performed a large pooled analysis in Japan using data from nine cohorts with 41,206 participants aged 40-89 years who were free of cardiovascular disease at baseline. We divided participants into three groups: isolated low HDL-C, non-isolated low HDL-C, and normal HDL-C. Cohort-stratified Cox proportional hazards models were used to estimate multivariate-adjusted hazard ratios (HRs) for death due to CHD, ischemic stroke, and intracranial cerebral hemorrhage; during a 12.9-year follow-up, we observed 355, 286, and 138 deaths, respectively, in these groups. Non-isolated low HDL-C was significantly associated with increased risk of CHD compared with normal HDL-C (HR 1.37, 95 % confidence interval (CI) 1.04-1.80); however, isolated low HDL-C was not. Although isolated low HDL-C was significantly associated with decreased risk of CHD (HR 0.51, 95 % CI 0.29-0.89) in women, it was significantly associated with increased risk of intracranial cerebral hemorrhage in all participants (HR 1.62, 95 % CI 1.04-2.53) and in men (HR 2.00, 95 % CI 1.04-3.83). In conclusion, isolated low HDL-C levels are not associated with increased risk of CHD in Japan. CHD risk may, therefore, be more strongly affected by serum total cholesterol levels in this population.

The enzymatic hydrolysis of soy protein isolate by Corolase PP under high hydrostatic pressure and its effect on bioactivity and characteristics of hydrolysates.

Science.gov (United States)

Guan, Haining; Diao, Xiaoqin; Jiang, Fan; Han, Jianchun; Kong, Baohua

2018-04-15

Enzymatic hydrolysis of soy protein isolate by Corolase PP under high hydrostatic pressure conditions was studied and the effects of hydrolysis on antioxidant and antihypertensive activities were investigated. As observed, high hydrostatic pressure (80-300MPa) enhanced the hydrolytic efficiency of Corolase PP and decreased the surface hydrophobicity of the hydrolysates. Hydrolysates obtained at 200MPa for 4h had higher bioactivities (reducing power, ABTS radical-scavenging and ACE inhibitory activities). The molecular weight (MW) determination indicated that hydrolysis at high hydrostatic pressure could increase the production of small peptides (hydrostatic pressure combined with Corolase PP treatments could be used as a potential technology to produce bioactive peptides from soy protein isolate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Numerical Solutions for Nonlinear High Damping Rubber Bearing Isolators: Newmark's Method with Netwon-Raphson Iteration Revisited

Science.gov (United States)

Markou, A. A.; Manolis, G. D.

2018-03-01

Numerical methods for the solution of dynamical problems in engineering go back to 1950. The most famous and widely-used time stepping algorithm was developed by Newmark in 1959. In the present study, for the first time, the Newmark algorithm is developed for the case of the trilinear hysteretic model, a model that was used to describe the shear behaviour of high damping rubber bearings. This model is calibrated against free-vibration field tests implemented on a hybrid base isolated building, namely the Solarino project in Italy, as well as against laboratory experiments. A single-degree-of-freedom system is used to describe the behaviour of a low-rise building isolated with a hybrid system comprising high damping rubber bearings and low friction sliding bearings. The behaviour of the high damping rubber bearings is simulated by the trilinear hysteretic model, while the description of the behaviour of the low friction sliding bearings is modeled by a linear Coulomb friction model. In order to prove the effectiveness of the numerical method we compare the analytically solved trilinear hysteretic model calibrated from free-vibration field tests (Solarino project) against the same model solved with the Newmark method with Netwon-Raphson iteration. Almost perfect agreement is observed between the semi-analytical solution and the fully numerical solution with Newmark's time integration algorithm. This will allow for extension of the trilinear mechanical models to bidirectional horizontal motion, to time-varying vertical loads, to multi-degree-of-freedom-systems, as well to generalized models connected in parallel, where only numerical solutions are possible.

Does the mortality risk of social isolation depend upon socioeconomic factors?

Science.gov (United States)

Patterson, Andrew C

2016-10-01

This study considers whether socioeconomic status influences the impact of social isolation on mortality risk. Using data from the Alameda County Study, Cox proportional hazard models indicate that having a high income worsens the mortality risk of social isolation. Education may offset risk, however, and the specific pattern that emerges depends on which measures for socioeconomic status and social isolation are included. Additionally, lonely people who earn high incomes suffer especially high risk of accidents and suicides as well as cancer. Further research is needed that contextualizes the health risks of social isolation within the broader social environment. © The Author(s) 2015.

New Data on Vaccine Antigen Deficient Bordetella pertussis Isolates

Directory of Open Access Journals (Sweden)

Valérie Bouchez

2015-09-01

Full Text Available Evolution of Bordetella pertussis is driven by natural and vaccine pressures. Isolates circulating in regions with high vaccination coverage present multiple allelic and antigenic variations as compared to isolates collected before introduction of vaccination. Furthermore, during the last epidemics reported in regions using pertussis acellular vaccines, isolates deficient for vaccine antigens, such as pertactin (PRN, were reported to reach high proportions of circulating isolates. More sporadic filamentous hemagglutinin (FHA or pertussis toxin (PT deficient isolates were also collected. The whole genome of some recent French isolates, deficient or non-deficient in vaccine antigens, were analyzed. Transcription profiles of the expression of the main virulence factors were also compared. The invasive phenotype in an in vitro human tracheal epithelial (HTE cell model of infection was evaluated. Our genomic analysis focused on SNPs related to virulence genes known to be more likely to present allelic polymorphism. Transcriptomic data indicated that isolates circulating since the introduction of pertussis vaccines present lower transcription levels of the main virulence genes than the isolates of the pre-vaccine era. Furthermore, isolates not producing FHA present significantly higher expression levels of the entire set of genes tested. Finally, we observed that recent isolates are more invasive in HTE cells when compared to the reference strain, but no multiplication occurs within cells.

Kinetics of microstructure formation of high-pressure induced gel from a whey protein isolate

Science.gov (United States)

He, Jin-Song; Yang, Hongwei; Zhu, Wanpeng; Mu, Tai-Hua

2010-03-01

The kinetic process of pressure-induced gelation of whey protein isolate (WPI) solutions was studied using in situ light scattering. The relationship of the logarithm of scattered light intensity (I) versus time (t) was linear after the induced time and could be described by the Cahn-Hilliard linear theory. With increasing time, the scattered intensity deviated from the exponential relationship, and the time evolution of the scattered light intensity maximum Im and the corresponding wavenumber qm could be described in terms of the power-law relationship as Im~fβ and qm~f-α, respectively. These results indicated that phase separation occurred during the gelation of WPI solutions under high pressure.

Isolation and characterization of highly pathogenic avian influenza virus subtype H5N1 from donkeys

Science.gov (United States)

2010-01-01

Background The highly pathogenic H5N1 is a major avian pathogen that crosses species barriers and seriously affects humans as well as some mammals. It mutates in an intensified manner and is considered a potential candidate for the possible next pandemic with all the catastrophic consequences. Methods Nasal swabs were collected from donkeys suffered from respiratory distress. The virus was isolated from the pooled nasal swabs in specific pathogen free embryonated chicken eggs (SPF-ECE). Reverse transcriptase polymerase chain reaction (RT-PCR) and sequencing of both haemagglutingin and neuraminidase were performed. H5 seroconversion was screened using haemagglutination inhibition (HI) assay on 105 donkey serum samples. Results We demonstrated that H5N1 jumped from poultry to another mammalian host; donkeys. Phylogenetic analysis showed that the virus clustered within the lineage of H5N1 from Egypt, closely related to 2009 isolates. It harboured few genetic changes compared to the closely related viruses from avian and humans. The neuraminidase lacks oseltamivir resistant mutations. Interestingly, HI screening for antibodies to H5 haemagglutinins in donkeys revealed high exposure rate. Conclusions These findings extend the host range of the H5N1 influenza virus, possess implications for influenza virus epidemiology and highlight the need for the systematic surveillance of H5N1 in animals in the vicinity of backyard poultry units especially in endemic areas. PMID:20398268

Schizosaccharomyces isolation method

Directory of Open Access Journals (Sweden)

Benito Santiago

2014-01-01

Full Text Available This study discusses the optimization of a selective and differential medium which would facilitate the isolation of Schizosaccharomyces (a genus with a low incidence compared to other microorganisms to select individuals from this genus for industrial purposes, especially in light of the recent recommendation of the use of yeasts from this genus in the wine industry by the International Organisation of Vine and Wine, or to detect the presence of such yeasts, for those many authors who consider them food spoilers. To this end, we studied various selective differential agents based on the main physiological characteristics of these species, such as their high resistances to high concentrations of sugar, sulfur dioxide, sorbic acid, benzoic acid, acetic acid or malo ethanolic fermentation. This selective medium is based on the genus resistance to the antibiotic actidione and its high resistance to inhibitory agents such as benzoic acid. Malic acid was used as a differential factor due to the ability of this genus to metabolise it to ethanol, which allows detecting of the degradation of this compound. Lastly, the medium was successfully used to isolate strains of Schizosaccharomyces pombe from honey and honeycombs.

Isolation and Characterization of Avian Influenza Viruses, Including Highly Pathogenic H5N1, from Poultry in Live Bird Markets in Hanoi, Vietnam, in 2001

Science.gov (United States)

Nguyen, Doan C.; Uyeki, Timothy M.; Jadhao, Samadhan; Maines, Taronna; Shaw, Michael; Matsuoka, Yumiko; Smith, Catherine; Rowe, Thomas; Lu, Xiuhua; Hall, Henrietta; Xu, Xiyan; Balish, Amanda; Klimov, Alexander; Tumpey, Terrence M.; Swayne, David E.; Huynh, Lien P. T.; Nghiem, Ha K.; Nguyen, Hanh H. T.; Hoang, Long T.; Cox, Nancy J.; Katz, Jacqueline M.

2005-01-01

Since 1997, outbreaks of highly pathogenic (HP) H5N1 and circulation of H9N2 viruses among domestic poultry in Asia have posed a threat to public health. To better understand the extent of transmission of avian influenza viruses (AIV) to humans in Asia, we conducted a cross-sectional virologic study in live bird markets (LBM) in Hanoi, Vietnam, in October 2001. Specimens from 189 birds and 18 environmental samples were collected at 10 LBM. Four influenza A viruses of the H4N6 (n = 1), H5N2 (n = 1), and H9N3 (n = 2) subtypes were isolated from healthy ducks for an isolation frequency of over 30% from this species. Two H5N1 viruses were isolated from healthy geese. The hemagglutinin (HA) genes of these H5N1 viruses possessed multiple basic amino acid motifs at the cleavage site, were HP for experimentally infected chickens, and were thus characterized as HP AIV. These HA genes shared high amino acid identities with genes of other H5N1 viruses isolated in Asia during this period, but they were genetically distinct from those of H5N1 viruses isolated from poultry and humans in Vietnam during the early 2004 outbreaks. These viruses were not highly virulent for experimentally infected ducks, mice, or ferrets. These results establish that HP H5N1 viruses with properties similar to viruses isolated in Hong Kong and mainland China circulated in Vietnam as early as 2001, suggest a common source for H5N1 viruses circulating in these Asian countries, and provide a framework to better understand the recent widespread emergence of HP H5N1 viruses in Asia. PMID:15767421

A highly efficient nonchemical method for isolating live nematodes (Caenorhabditis elegans) from soil during toxicity assays.

Science.gov (United States)

Kim, Shin Woong; Moon, Jongmin; An, Youn-Joo

2015-01-01

The success of soil toxicity tests using Caenorhabditis elegans may depend in large part on recovering the organisms from the soil. However, it can be difficult to learn the International Organization for Standardization/ASTM International recovery process that uses the colloidal silica flotation method. The present study determined that a soil-agar isolation method provides a highly efficient and less technically demanding alternative to the colloidal silica flotation method. Test soil containing C. elegans was arranged on an agar plate in a donut shape, a linear shape, or a C curve; and microbial food was placed outside the soil to encourage the nematodes to leave the soil. The effects of ventilation and the presence of food on nematode recovery were tested to determine the optimal conditions for recovery. A linear arrangement of soil on an agar plate that was sprinkled with microbial food produced nearly 83% and 90% recovery of live nematodes over a 3-h and a 24-h period, respectively, without subjecting the nematodes to chemical stress. The method was tested using copper (II) chloride dihydrate, and the resulting recovery rate was comparable to that obtained using colloidal silica flotation. The soil-agar isolation method portrayed in the present study enables live nematodes to be isolated with minimal additional physicochemical stress, making it a valuable option for use in subsequent sublethal tests where live nematodes are required. © 2014 SETAC.

Preliminary screening of bacterial isolates from mining wastes

Directory of Open Access Journals (Sweden)

Rodino S.,

2016-05-01

Full Text Available Developing innovative biotechnology for obtaining new resources of high tech critical metals is strongly influenced by the need to reduce the potential risk of shortages, to support the development of industry at European level. To set up these new technologies is essential to isolate strains with high potential in bioleaching of ore, tailings and mine wastes and bioaccumulation of high tech critical metals. Microorganisms are capable of mediating metal and mineral bioprecipitation. In this paper are presented preliminary studies performed for the isolation of strains existing in mining residues containing high tech critical metals. Were used samples collected from various depths in an area of mining wastes containing high tech critical metals. The samples were fine grounded and the powder was washed with sterile saline water. Exact quantities of samples were dispersed in sterile saline water, shaken for a period of 60 minutes, diluted and plated in triplicate on selective agar. After several steps were isolated 3 strains of gram negative bacteria.

High-Efficiency Isolated Photovoltaic Microinverter Using Wide-Band Gap Switches for Standalone and Grid-Tied Applications

Directory of Open Access Journals (Sweden)

Yu-Chen Liu

2018-03-01

Full Text Available An isolated photovoltaic micro-inverter for standalone and grid-tied applications is designed and implemented to achieve high efficiency. System configuration and design considerations, including the proposed active-clamp forward-flyback resonant converter for the DC-DC stage and a dual-frequency full-bridge inverter for the DC-AC stage, are analyzed and discussed. A prototype microinverter system is built and tested. Experimental results verify the feasibility of the proposed system, which achieves 95% power conversion efficiency at full load.

Isolation and characterization of thermotolerant ethanol-fermenting ...

African Journals Online (AJOL)

Thermotolerant yeasts, which are expected to be applicable for high-temperature fermentation as an economical process, were isolated from four provinces in Laos. Of these yeasts, five isolates exhibited stronger fermentation abilities in a 16% sugars-containing medium of glucose, sucrose, sugarcane or molasses at 40°C ...

Comparison of multi-drug resistant environmental methicillin-resistant Staphylococcus aureus [MRSA] isolated from recreational beaches and high touch surfaces in built environments

Directory of Open Access Journals (Sweden)

Marilyn C Roberts

2013-04-01

Full Text Available Over the last decade community-acquired methicillin-resistant Staphylococcus aureus [MRSA] has emerged as a major cause of disease in the general population with no health care exposure or known classical risk factors for MRSA infections. The potential community reservoirs have not been well defined though certain strains such as ST398 and USA300 have been well studied in some settings. MRSA has been isolated from recreational beaches, high-touch surfaces in homes, universities and other community environmental surfaces. However, in most cases the strains were not characterized to determine if they are related to community-acquired or hospital-acquired clinical strains. We compared 55 environmental MRSA from 805 samples including sand, fresh and marine water samples from local marine and fresh water recreational beaches (n=296, high touch surfaces on the University of Washington campus (n=294, surfaces in UW undergraduate housing (n=85, and the local community (n=130. Eleven USA300, representing 20% of the isolates, were found on the UW campus surfaces, student housing surfaces and on the community surfaces but not in the recreational beach samples from the Northwest USA. Similarly, the predominant animal ST133 was found in the recreational beach samples but not in the high touch surface samples. All USA300 isolates were multi-drug resistant carrying 2-6 different antibiotic resistance genes coding for kanamycin, macrolides and/or macrolides-lincosamides-streptogramin B and tetracycline, with the majority [72%] carrying 4-6 different antibiotic resistance genes. A surprising 98% of the 55 MRSA isolates were resistant to other classes of antibiotics and most likely represent reservoirs for these genes in the environment.

Random inbreeding, isonymy, and population isolates in Argentina.

Science.gov (United States)

Dipierri, José; Rodríguez-Larralde, Alvaro; Barrai, Italo; Camelo, Jorge López; Redomero, Esperanza Gutiérrez; Rodríguez, Concepción Alonso; Ramallo, Virginia; Bronberg, Rubén; Alfaro, Emma

2014-07-01

Population isolates are an important tool in identifying and mapping genes of Mendelian diseases and complex traits. The geographical identification of isolates represents a priority from a genetic and health care standpoint. The purpose of this study is to analyze the spatial distribution of consanguinity by random isonymy (F ST) in Argentina and its relationship with the isolates previously identified in the country. F ST was estimated from the surname distribution of 22.6 million electors registered for the year 2001 in the 24 provinces, 5 geographical regions, and 510 departments of the country. Statistically significant spatial clustering of F ST was determined using the SaTScan V5.1 software. F ST exhibited a marked regional and departamental variation, showing the highest values towards the North and West of Argentina. The clusters of high consanguinity by random isonymy followed the same distribution. Recognized Argentinean genetic isolates are mainly localized at the north of the country, in clusters of high inbreeding. Given the availability of listings of surnames in high-capacity storage devices for different countries, estimating F ST from them can provide information on inbreeding for all levels of administrative subdivisions, to be used as a demographic variable for the identification of isolates within the country for public health purposes.

Experimental investigation of acoustic streaming in a cylindrical wave guide up to high streaming Reynolds numbers.

Science.gov (United States)

Reyt, Ida; Bailliet, Hélène; Valière, Jean-Christophe

2014-01-01

Measurements of streaming velocity are performed by means of Laser Doppler Velocimetry and Particle Image Velociimetry in an experimental apparatus consisting of a cylindrical waveguide having one loudspeaker at each end for high intensity sound levels. The case of high nonlinear Reynolds number ReNL is particularly investigated. The variation of axial streaming velocity with respect to the axial and to the transverse coordinates are compared to available Rayleigh streaming theory. As expected, the measured streaming velocity agrees well with the Rayleigh streaming theory for small ReNL but deviates significantly from such predictions for high ReNL. When the nonlinear Reynolds number is increased, the outer centerline axial streaming velocity gets distorted towards the acoustic velocity nodes until counter-rotating additional vortices are generated near the acoustic velocity antinodes. This kind of behavior is followed by outer streaming cells only and measurements in the near wall region show that inner streaming vortices are less affected by this substantial evolution of fast streaming pattern. Measurements of the transient evolution of streaming velocity provide an additional insight into the evolution of fast streaming.

Nanophotonic Optical Isolator Controlled by the Internal State of Cold Atoms

Directory of Open Access Journals (Sweden)

Clément Sayrin

2015-12-01

Full Text Available The realization of nanophotonic optical isolators with high optical isolation even at ultralow light levels and low optical losses is an open problem. Here, we employ the link between the local polarization of strongly confined light and its direction of propagation to realize low-loss nonreciprocal transmission through a silica nanofiber at the single-photon level. The direction of the resulting optical isolator is controlled by the spin state of cold atoms. We perform our experiment in two qualitatively different regimes, i.e., with an ensemble of cold atoms where each atom is weakly coupled to the waveguide and with a single atom strongly coupled to the waveguide mode. In both cases, we observe simultaneously high isolation and high forward transmission. The isolator concept constitutes a nanoscale quantum optical analog of microwave ferrite resonance isolators, can be implemented with all kinds of optical waveguides and emitters, and might enable novel integrated optical devices for fiber-based classical and quantum networks.

Isolation and Characterization of Thermophilic Bacteria from Jordanian Hot Springs: Bacillus licheniformis and Thermomonas hydrothermalis Isolates as Potential Producers of Thermostable Enzymes.

Science.gov (United States)

Mohammad, Balsam T; Al Daghistani, Hala I; Jaouani, Atef; Abdel-Latif, Saleh; Kennes, Christian

2017-01-01

The aim of this study was the isolation and characterization of thermophilic bacteria from hot springs in Jordan. Ten isolates were characterized by morphological, microscopic, biochemical, molecular, and physiological characteristics. Sequencing of the 16S rDNA of the isolates followed by BLAST search revealed that nine strains could be identified as Bacillus licheniformis and one isolate as Thermomonas hydrothermalis . This is the first report on the isolation of Thermomonas species from Jordanian hot springs. The isolates showed an ability to produce some thermostable enzymes such as amylase, protease, cellulose, gelatins, and lecithin. Moreover, the UPGMA dendrogram of the enzymatic characteristics of the ten isolates was constructed; results indicated a high phenotypic diversity, which encourages future studies to explore further industrial and environmental applications.

Isolation and Characterization of Thermophilic Bacteria from Jordanian Hot Springs: Bacillus licheniformis and Thermomonas hydrothermalis Isolates as Potential Producers of Thermostable Enzymes

Directory of Open Access Journals (Sweden)

Balsam T. Mohammad

2017-01-01

Full Text Available The aim of this study was the isolation and characterization of thermophilic bacteria from hot springs in Jordan. Ten isolates were characterized by morphological, microscopic, biochemical, molecular, and physiological characteristics. Sequencing of the 16S rDNA of the isolates followed by BLAST search revealed that nine strains could be identified as Bacillus licheniformis and one isolate as Thermomonas hydrothermalis. This is the first report on the isolation of Thermomonas species from Jordanian hot springs. The isolates showed an ability to produce some thermostable enzymes such as amylase, protease, cellulose, gelatins, and lecithin. Moreover, the UPGMA dendrogram of the enzymatic characteristics of the ten isolates was constructed; results indicated a high phenotypic diversity, which encourages future studies to explore further industrial and environmental applications.

New non-linear control strategy for non-isolated DC/DC converter with high voltage ratio

Energy Technology Data Exchange (ETDEWEB)

Shahin, A.; Huang, B.; Martin, J.P.; Pierfederici, S.; Davat, B. [Groupe de Recherche en Electronique et en Electrotechnique de Nancy - INPL - Nancy Universite, 2, Avenue de la Foret de Haye, 54516 Vandoeuvre-les-Nancy Cedex (France)

2010-01-15

In this paper, a non-isolated DC/DC converter with high voltage ratio is proposed to allow the interface between a low voltage power source like fuel cell and a high voltage DC bus. To take into account the low voltage-high density characteristics of power sources, a cascaded structure composed of two sub-converters has been chosen and allows obtaining a high voltage ratio. The choice of each sub-converter is based on the requirements of the source and its performances. Consequently, we have chosen a three-interleaved boost converter as the 1st sub-converter whereas the 2nd sub-converter is a three-level boost converter. The control of the whole system is realized thanks to energetic trajectories planning based on flatness properties of the system. The control of both the current and the balance of voltage across the output serial capacitors of the three-level boost converter is ensured by non-linear controllers based on a new non-linear model. Experimental results allow validating the proposed power architecture and its associated control. (author)

New non-linear control strategy for non-isolated DC/DC converter with high voltage ratio

International Nuclear Information System (INIS)

Shahin, A.; Huang, B.; Martin, J.P.; Pierfederici, S.; Davat, B.

2010-01-01

In this paper, a non-isolated DC/DC converter with high voltage ratio is proposed to allow the interface between a low voltage power source like fuel cell and a high voltage DC bus. To take into account the low voltage-high density characteristics of power sources, a cascaded structure composed of two sub-converters has been chosen and allows obtaining a high voltage ratio. The choice of each sub-converter is based on the requirements of the source and its performances. Consequently, we have chosen a three-interleaved boost converter as the 1st sub-converter whereas the 2nd sub-converter is a three-level boost converter. The control of the whole system is realized thanks to energetic trajectories planning based on flatness properties of the system. The control of both the current and the balance of voltage across the output serial capacitors of the three-level boost converter is ensured by non-linear controllers based on a new non-linear model. Experimental results allow validating the proposed power architecture and its associated control.

Design of S-Band Phased Array Antenna with High Isolation Using Broadside Coupled Split Ring Resonator

Directory of Open Access Journals (Sweden)

Sungyoun Hwang

2018-04-01

Full Text Available In this paper, a method of designing a Vivaldi type phased array antenna (PAA which operates at S-band (2.8–3.3 GHz is presented. The presented antenna uses broadside coupled split ring resonators (BC-SRRs for high isolation, wide field of view, and good active S-parameter characteristics. As an example, we design a 1 × 8 array antenna with various BC-SRR structures using theory and EM simulations. The antenna is fabricated and measured to verify the design. With the BC-SRR implemented between the two radiating elements, the isolation is shown to be enhanced by 6 dB, up to 23 dB. The scan angle is shown to be within ±53° based on a −10 dB active reflection coefficient. The operation of the scan angle is possible within ±60° with a little larger reflection coefficient (−7 dB to −8 dB. The proposed design with BC-SRRs is expected to be useful for PAA applications.

Genetic characterisation of tigecycline-resistant Enterobacter spp. in blood isolates causing bacteraemia.

Science.gov (United States)

Cha, Min Kyeong; Kang, Cheol-In; Park, Ga Eun; Kim, So Hyun; Chung, Doo Ryeon; Peck, Kyong Ran; Song, Jae-Hoon

2018-01-05

Tigecycline (TIG) is one of the most important antimicrobial agents used to treat infections by multidrug-resistant bacteria. However, rates of TIG-resistant pathogens have increased recently. This study was conducted to identify the antimicrobial susceptibility profiles and to investigate the role of efflux pumps in high-level TIG-resistant Enterobacter spp. isolates causing bacteraemia. A total of 323 Enterobacter spp. causing bacteraemia were collected from eight hospitals in various regions of South Korea. Minimum inhibitory concentrations (MICs) were determined by the broth microdilution method and Etest. Expression levels of the efflux pump gene acrA and its regulators (ramA and rarA) were examined by quantitative real-time PCR. Isolate relatedness was determined by multilocus sequence typing (MLST). Among the 323 clinical isolates included in this study, 37 (11.5%) were TIG-non-susceptible, of which 8 isolates were highly resistant to TIG with MICs of 8mg/L (4 isolates) or 16mg/L (4 isolates). All high-level TIG-resistant isolates showed increased expression of acrA (0.93-13.3-fold) and ramA (1.4-8.2-fold). Isolates with a tigecycline MIC of 16mg/L also showed overexpression of rarA compared with TIG-susceptible isolates. In this study, overexpression of acrA, ramA and rarA was observed in high-level TIG-resistant Enterobacter spp. isolates. We suggest that rarA might be involved in the regulation of acrA overexpression in high-level TIG-resistant Enterobacter spp. isolates. Efflux pump-mediated resistance should be closely monitored because it could be indirectly attributed to the use of other antibiotics transported by the same efflux pump. Copyright © 2017. Published by Elsevier Ltd.

Comparative analysis of the full genome of Helicobacter pylori isolate Sahul64 identifies genes of high divergence.

Science.gov (United States)

Lu, Wei; Wise, Michael J; Tay, Chin Yen; Windsor, Helen M; Marshall, Barry J; Peacock, Christopher; Perkins, Tim

2014-03-01

Isolates of Helicobacter pylori can be classified phylogeographically. High genetic diversity and rapid microevolution are a hallmark of H. pylori genomes, a phenomenon that is proposed to play a functional role in persistence and colonization of diverse human populations. To provide further genomic evidence in the lineage of H. pylori and to further characterize diverse strains of this pathogen in different human populations, we report the finished genome sequence of Sahul64, an H. pylori strain isolated from an indigenous Australian. Our analysis identified genes that were highly divergent compared to the 38 publically available genomes, which include genes involved in the biosynthesis and modification of lipopolysaccharide, putative prophage genes, restriction modification components, and hypothetical genes. Furthermore, the virulence-associated vacA locus is a pseudogene and the cag pathogenicity island (cagPAI) is not present. However, the genome does contain a gene cluster associated with pathogenicity, including dupA. Our analysis found that with the addition of Sahul64 to the 38 genomes, the core genome content of H. pylori is reduced by approximately 14% (∼170 genes) and the pan-genome has expanded from 2,070 to 2,238 genes. We have identified three putative horizontally acquired regions, including one that is likely to have been acquired from the closely related Helicobacter cetorum prior to speciation. Our results suggest that Sahul64, with the absence of cagPAI, highly divergent cell envelope proteins, and a predicted nontransportable VacA protein, could be more highly adapted to ancient indigenous Australian people but with lower virulence potential compared to other sequenced and cagPAI-positive H. pylori strains.

Genetic diversity among brazilian isolates of beauveria bassiana: comparisons with non-brazilian isolates and other beauveria species

Science.gov (United States)

Fernandes, E.K.K.; Moraes, A.M.L.; Pacheco, R.S.; Rangel, D.E.N.; Miller, M.P.; Bittencourt, V.R.E.P.; Roberts, D.W.

2009-01-01

Aims: The genetic diversity of Beauveria bassiana was investigated by comparing isolates of this species to each other (49 from different geographical regions of Brazil and 4 from USA) and to other Beauveria spp. Methods and Results: The isolates were examined by multilocus enzyme electrophoresis (MLEE), amplified fragment length polymorphism (AFLP), and rDNA sequencing. MLEE and AFLP revealed considerable genetic variability among B. bassiana isolates. Several isolates from South and Southeast Brazil had high similarity coefficients, providing evidence of at least one population with clonal structure. There were clear genomic differences between most Brazilian and USA B. bassiana isolates. A Mantel test using data generated by AFLP provided evidence that greater geographical distances were associated with higher genetic distances. AFLP and rDNA sequencing demonstrated notable genotypic variation between B. bassiana and other Beauveria spp. Conclusion: Geographical distance between populations apparently is an important factor influencing genotypic variability among B. bassiana populations in Brazil. Significance and Impact of the Study: This study characterized many B. bassiana isolates. The results indicate that certain Brazilian isolates are considerably different from others and possibly should be regarded as separate species from B. bassiana sensu latu. The information on genetic variation among the Brazilian isolates, therefore, will be important to comprehending the population structure of B. bassiana in Brazil. ?? 2009 The Society for Applied Microbiology.

Isolation and characterization of Ethanologenbacterium HitB49 gen. nov. sp. nov., an anaerobic, high hydrogen-producing bacterium with a special ethanol-type-fermentation

Energy Technology Data Exchange (ETDEWEB)

Lin, M. [Harbin Inst. of Technology, Harbin, HL (China). School of Municipal and Environmental Engineering]|[Nanyang Technological Univ., Singapore (Singapore). Inst. of Environmental Science and Engineering; Ren, N.Q.; Wang, A.J. [Harbin Inst. of Technology, Harbin, HL (China). School of Municipal and Environmental Engineering; Liang, D.T.; Tay, J.H. [Nanyang Technological Univ., Singapore (Singapore). Inst. of Environmental Science and Engineering

2004-07-01

Hydrogen, an important future energy source, can be produced by several fermentative microorganisms. The factor that prevents widespread biohydrogen production is the difficulty in isolating the ideal high hydrogen-producing bacterium (HPB). In this study, the Hungate technology was used to isolate and cultivate 210 strains of dominant fermentative bacteria. They were isolated from 6 sludges with ethanol-type fermentation (ETF) bioreactors. The study examined the production of hydrogen in pH 4, very low pH in ETF. The maximum rate in the biohydrogen-producing reactor was promising under continuous flow condition. The novel genus of HPB was Ethanologenbacterium Hit, of which strain B49 belonged to the ETF bacteria.

Kinetics of microstructure formation of high-pressure induced gel from a whey protein isolate

International Nuclear Information System (INIS)

He Jinsong; Yang Hongwei; Zhu Wanpeng; Mu Taihua

2010-01-01

The kinetic process of pressure-induced gelation of whey protein isolate (WPI) solutions was studied using in situ light scattering. The relationship of the logarithm of scattered light intensity (I) versus time (t) was linear after the induced time and could be described by the Cahn-Hilliard linear theory. With increasing time, the scattered intensity deviated from the exponential relationship, and the time evolution of the scattered light intensity maximum I m and the corresponding wavenumber q m could be described in terms of the power-law relationship as I m ∼f β and q m ∼f -α , respectively. These results indicated that phase separation occurred during the gelation of WPI solutions under high pressure.

Study of the Mechanical Properties and Vibration Isolation Performance of a Molecular Spring Isolator

Directory of Open Access Journals (Sweden)

Muchun Yu

2016-01-01

Full Text Available Molecular Spring Isolator (MSI is a novel passive vibration isolation technique, providing High-Static-Low-Dynamic (HSLD stiffness based on the use of molecular spring material. The molecular spring material is a solid-liquid mixture consisting of water and hydrophobic nanoporous materials. Under a certain level of external pressure, water molecules can intrude into the hydrophobic pores of nanoporous materials, developing an additional solid-liquid interface. Such interfaces are able to store, release, and transform mechanical energy, providing properties like mechanical spring. Having been only recently developed, the basic mechanic properties of a MSI have not been studied in depth. This paper focuses on the stiffness influence factors, the dynamic frequency response, and the vibration isolation performance of a MSI; these properties help engineers to design MSIs for different engineering applications. First, the working mechanism of a MSI is introduced from a three-dimensional general view of the water infiltration massive hydrophobic nanoporous pores. Next, a wide range of influence factors on the stiffness properties of MSI are studied. In addition, the frequency response functions (FRFs of the MSI vibration isolation system are studied utilizing the matching method based on equivalent piecewise linear (EPL system. Finally, the vibration isolation properties of MSI are evaluated by force transmissibility.

Isolation of Lactic Acid Bacteria with High Biological Activity from Local Fermented Dairy Products

OpenAIRE

B. Munkhtsetseg; M. Margad-Erdene; B. Batjargal

2009-01-01

The thirty-two strains of lactic acid bacteria were isolated from the Mongolian traditional fermented dairy products, among them 25 strains show antimicrobial activity against test microorganisms including Escherichia coli , Staphylococcus aureus , Enterococcus faecalis , Pseudom о nas aeruginosa . Protease sensitivity assay demonstrated that the antimicrobial substances produced by isolates А 23, Т 2 are bacterio...

Isolation and Purification of Unstable Iridoid Glucosides from Traditional Chinese Medicine by Preparative High Performance Liquid Chromatography Coupled with Solid-phase Extraction

Institute of Scientific and Technical Information of China (English)

无

2011-01-01

An efficient preparative method was successfully developed for isolation and purification of unstable components from medicinal plant extracts, using a combined method of preparative high performance liquid chro-matography（HPLC） and solid-phase extraction（SPE）. The aim of this study was to obtain an effective method with high preparative efficiency and importantly to avoid the transformation of unstable compounds. The preparative HPLC system was based on an LC/MS controlled four-channel autopurification system. The SPE method was performed with a C18 packing material to trap the target compounds and to remove the acidic additive derived from the mobile phase. Using this method, the unstable iridoid glucosides（IGs） as model compounds were successfully isolated and purified from the extract of Hedyotis diffusa Willd. Six IGs（including one new minor IG） and one nucleotide compound were simultaneously obtained, each with a purity of 〉91% as determined by HPLC. The structures of the isolated compounds were identified by UPLC/Q-TOF MS, UV, 1D and/or 2D NMR. It was demonstrated that the combination of preparative HPLC with SPE is a versatile tool for preparative purification of unstable compounds from complex natural products.

A parylene-filled-trench technique for thermal isolation in silicon-based microdevices

International Nuclear Information System (INIS)

Lei Yinhua; Wang Wei; Li Ting; Jin Yufeng; Zhang Haixia; Li Zhihong; Yu Huaiqiang; Luo Yingcun

2009-01-01

Microdevices prepared in a silicon substrate have been widely used in versatile fields due to the matured silicon-based microfabrication technique and the excellent physical properties of silicon material. However, the high thermal conductivity of silicon restricts its application in most thermal microdevices, especially devices comprising different temperature zones. In this work, a parylene-filled-trench technique was optimized to realize high-quality thermal isolation in silicon-based microdevices. Parylene C, a heat transfer barricading material, was deposited on parallel high-aspect-ratio trenches, which surrounded the isolated target zones. After removing the remnant silicon beneath the trenches by deep reactive ion etching from the back side, a high-quality heat transfer barrier was obtained. By using narrow trenches, only 5 µm thick parylene was required for a complete filling, which facilitated multi-layer interconnection thereafter. The parylene filling performance inside the high-aspect-ratio trench was optimized by two approaches: multiple etch–deposition cycling and trench profile controlling. A 4 × 6 array, in which each unit was kept at a constant temperature and was well thermally isolated individually, was achieved on a silicon substrate by using the present parylene-filled-trench technique. The preliminary experimental results indicated that the present parylene-filled-trench structure exhibited excellent thermal isolation performance, with a very low power requirement of 0.134 mW (K mm 2 ) −1 for heating the isolated silicon unit and a high thermal isolation efficiency of 72.5% between two adjacent units. Accompanied with high-quality isolation performance, the microdevices embedded the present parylene-filled-trench structure to retain a strong mechanical connection larger than 400 kPa between two isolated zones, which is very important for a high-reliability-required micro-electro-mechanical-system (MEMS) device. Considering its room

Isolation and characterization of highly pathogenic avian influenza virus subtype H5N1 from donkeys

Directory of Open Access Journals (Sweden)

Abdel-Ghany Ahmad E

2010-04-01

Full Text Available Abstract Background The highly pathogenic H5N1 is a major avian pathogen that crosses species barriers and seriously affects humans as well as some mammals. It mutates in an intensified manner and is considered a potential candidate for the possible next pandemic with all the catastrophic consequences. Methods Nasal swabs were collected from donkeys suffered from respiratory distress. The virus was isolated from the pooled nasal swabs in specific pathogen free embryonated chicken eggs (SPF-ECE. Reverse transcriptase polymerase chain reaction (RT-PCR and sequencing of both haemagglutingin and neuraminidase were performed. H5 seroconversion was screened using haemagglutination inhibition (HI assay on 105 donkey serum samples. Results We demonstrated that H5N1 jumped from poultry to another mammalian host; donkeys. Phylogenetic analysis showed that the virus clustered within the lineage of H5N1 from Egypt, closely related to 2009 isolates. It harboured few genetic changes compared to the closely related viruses from avian and humans. The neuraminidase lacks oseltamivir resistant mutations. Interestingly, HI screening for antibodies to H5 haemagglutinins in donkeys revealed high exposure rate. Conclusions These findings extend the host range of the H5N1 influenza virus, possess implications for influenza virus epidemiology and highlight the need for the systematic surveillance of H5N1 in animals in the vicinity of backyard poultry units especially in endemic areas.

Isolation of Flavonoids From Wild Aquilaria sinensis Leaves by an Improved Preparative High-Speed Counter-Current Chromatography Apparatus.

Science.gov (United States)

Yang, Mao-Xun; Liang, Yao-Guang; Chen, He-Ru; Huang, Yong-Fang; Gong, Hai-Guang; Zhang, Tian-You; Ito, Yoichiro

2018-01-01

Four flavonoids including apigenin-7,4'-dimethylether, genkwanin, quercetin, and kaempferol were isolated in a preparative or semi-preparative scale from the leaves of wild Aquilaria sinensis using an improved preparative high-speed counter-current chromatography apparatus. The separations were performed with a two-phase solvent system composed of hexane-ethyl acetate, methanol-water at suitable volume ratios. The obtained fractions were analyzed by HPLC, and the identification of each target compound was carried out by ESI-MS and NMR. The yields of the above four target flavonoids were 4.7, 10.0, 11.0 and 4.4%, respectively. All these four flavonoids exhibited nitrite scavenging activities with the clearance rate of 12.40 ± 0.20%, 5.84 ± 0.03%, 28.10 ± 0.17% and 5.19 ± 0.11%, respectively. Quercetin was originally isolated from the Thymelaeaceae family, while kaempferol was isolated from the Aquilaria genus for the first time. In cytotoxicity test these two flavonoids exhibited moderate inhibitory activities against HepG2 cells with the IC50 values of 12.54 ± 1.37 and 38.63 ± 4.05 μM, respectively. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

ALDH1-high ovarian cancer stem-like cells can be isolated from serous and clear cell adenocarcinoma cells, and ALDH1 high expression is associated with poor prognosis.

Directory of Open Access Journals (Sweden)

Takafumi Kuroda

Full Text Available Cancer stem-like cells (CSCs/cancer-initiating cells (CICs are defined as a small population of cancer cells that have high tumorigenicity. Furthermore, CSCs/CICs are resistant to several cancer therapies, and CSCs/CICs are therefore thought to be responsible for cancer recurrence after treatment and distant metastasis. In epithelial ovarian cancer (EOC cases, disease recurrence after chemotherapy is frequently observed, suggesting ovarian CSCs/CICs are involved. There are four major histological subtypes in EOC, and serous adenocarcinoma and clear cell adenocarcinoma are high-grade malignancies. We therefore analyzed ovarian CSCs/CICs from ovarian carcinoma cell lines (serous adenocarcinoma and clear cell adenocarcinoma and primary ovarian cancer cells in this study. We isolated ovarian CSCs/CICs as an aldehyde dehydrogenase 1 high (ALDH1(high population from 6 EOC cell lines (3 serous adenocarcinomas and 3 clear cell adenocarcinomas by the ALDEFLUOR assay. ALDH1(high cells showed greater sphere-forming ability, higher tumorigenicity and greater invasive capability, indicating that ovarian CSCs/CICs are enriched in ALDH1(high cells. ALDH1(high cells could also be isolated from 8 of 11 primary ovarian carcinoma samples. Immunohistochemical staining revealed that higher ALDH1 expression levels in ovary cancer cases are related to poorer prognosis in both serous adenocarcinoma cases and clear cell adenocarcinoma cases. Taken together, the results indicate that ALDH1 is a marker for ovarian CSCs/CICs and that the expression level of ALDH1 might be a novel biomarker for prediction of poor prognosis.

Molecular detection of an atypical, highly resistant, clonal Pseudomonas aeruginosa isolate in cystic fibrosis patients.

LENUS (Irish Health Repository)

Keating, Deirdre

2013-03-01

The identification of Pseudomonas aeruginosa (P. aeruginosa) isolates in sputum from cystic fibrosis (CF) patients can be challenging due to the multitude of phenotypic changes isolates undergo during adaptation to the microenvironment of the CF lung.

Isolation, identification and characterization of Bacillus amyloliquefaciens BZ-6, a bacterial isolate for enhancing oil recovery from oily sludge.

Science.gov (United States)

Liu, Wuxing; Wang, Xiaobing; Wu, Longhua; Chen, Mengfang; Tu, Chen; Luo, Yongming; Christie, Peter

2012-06-01

Over 100 biosurfactant-producing microorganisms were isolated from oily sludge and petroleum-contaminated soil from Shengli oil field in north China. Sixteen of the bacterial isolates produced biosurfactants and reduced the surface tension of the growth medium from 71 to treat oily sludge and the recovery efficiencies of oil from oily sludge were determined. The oil recovery efficiencies of different isolates ranged from 39% to 88%. Bacterial isolate BZ-6 was found to be the most efficient strain and the three phases (oil, water and sediment) were separated automatically after the sludge was treated with the culture medium of BZ-6. Based on morphological, physiological characteristics and molecular identification, isolate BZ-6 was identified as Bacillus amyloliquefaciens. The biosurfactant produced by isolate BZ-6 was purified and analyzed by high performance liquid chromatography-electrospray ionization tandem mass spectrometry. There were four ion peaks representing four different fengycin A homologues. Copyright © 2012. Published by Elsevier Ltd.

Criteria: waste tank isolation and stabilization

Energy Technology Data Exchange (ETDEWEB)

Metz, W.P.; Ogren, W.E.

1976-09-01

The crystallized Hanford high-level wastes stored in single-shell underground tanks consist of sludges and salt cakes covered with supernatural liquor. Purpose of stabilization and isolation is to reduce the releases and losses as a result of a loss of tank integrity. The tanks will be modified so that no inadvertent liquid additions can be made. Criteria for the isolation and stabilization are given and discussed briefly. (DLC)

Criteria: waste tank isolation and stabilization

International Nuclear Information System (INIS)

Metz, W.P.; Ogren, W.E.

1976-09-01

The crystallized Hanford high-level wastes stored in single-shell underground tanks consist of sludges and salt cakes covered with supernatural liquor. Purpose of stabilization and isolation is to reduce the releases and losses as a result of a loss of tank integrity. The tanks will be modified so that no inadvertent liquid additions can be made. Criteria for the isolation and stabilization are given and discussed briefly

Status report on activities on seismic isolation in Italy

International Nuclear Information System (INIS)

Martelli, A.; Bettinali, F.

1992-01-01

The development of seismic isolation and its application to structures other than bridges were started in Italy in 1988. Considerable efforts are being devoted to this technique, both because it can already be widely used in civil buildings (where it is particularly attractive for constructions that are critical for emergency and disaster planning), and due to the very promising perspectives for application to the industrial plants. In particular, ENEA is also quite interested in verifying the applicability of seismic isolation to the high risk plants, including the innovative nuclear reactors. The correct development of seismic isolation, for a future wide use in all the domains of interest - including high risk and other industrial plants - requires that a sufficient number of applications to civil buildings is -undertaken, so as to improve the knowledge on the design and behaviour of isolated structures. It also requires seismic monitoring of isolated constructions. This is the reason why all the ongoing studies in Italy - including those of ENEA and ENEL - are based at present on applications to civil buildings. To the aforesaid aims, R and D work is also needed: such a work, together with the experience acquired on actual isolated buildings, is essential to set up adequate design rules. On the other hand, development of design rules must be carried out in parallel, in order to determine the features of the necessary research activities. Until now, our development work has been focussed on the high damping steel-laminated rubber bearings, which have been adopted for most isolated buildings in Italy. It consists of: [a] the set-up of proposals for design rules and guidelines; [b] experiments on bearing materials, individual bearings, isolated structure mock-ups, and actual isolated buildings; [c] development and validation of simplified and detailed numerical models of bearings and structures. Furthermore, support is being provided to the designers of isolated

Streptomyces aridus sp. nov., isolated from a high altitude Atacama Desert soil and emended description of Streptomyces noboritoensis Isono et al. 1957.

Science.gov (United States)

Idris, Hamidah; Labeda, David P; Nouioui, Imen; Castro, Jean Franco; Del Carmen Montero-Calasanz, Maria; Bull, Alan T; Asenjo, Juan A; Goodfellow, Michael

2017-05-01

A polyphasic study was undertaken to determine the taxonomic status of a Streptomyces strain which had been isolated from a high altitude Atacama Desert soil and shown to have bioactive properties. The strain, isolate H9 T , was found to have chemotaxonomic, cultural and morphological properties that place it in the genus Streptomyces. 16S rRNA gene sequence analyses showed that the isolate forms a distinct branch at the periphery of a well-delineated subclade in the Streptomyces 16S rRNA gene tree together with the type strains of Streptomyces crystallinus, Streptomyces melanogenes and Streptomyces noboritoensis. Multi-locus sequence analysis (MLSA) based on five house-keeping gene alleles showed that isolate H9 T is closely related to the latter two type strains and to Streptomyces polyantibioticus NRRL B-24448 T . The isolate was distinguished readily from the type strains of S. melanogenes, S. noboritoensis and S. polyantibioticus using a combination of phenotypic properties. Consequently, the isolate is considered to represent a new species of Streptomyces for which the name Streptomyces aridus sp. nov. is proposed; the type strain is H9 T (=NCIMB 14965 T =NRRL B65268 T ). In addition, the MLSA and phenotypic data show that the S. melanogenes and S. noboritoensis type strains belong to a single species, it is proposed that S. melanogenes be recognised as a heterotypic synonym of S. noboritoensis for which an emended description is given.

Perceived Social Isolation and Outcomes in Patients With Heart Failure.

Science.gov (United States)

Manemann, Sheila M; Chamberlain, Alanna M; Roger, Véronique L; Griffin, Joan M; Boyd, Cynthia M; Cudjoe, Thomas K M; Jensen, Daniel; Weston, Susan A; Fabbri, Matteo; Jiang, Ruoxiang; Finney Rutten, Lila J

2018-05-23

Perceived social isolation has been shown to have a negative impact on health outcomes, particularly among older adults. However, these relationships have not been fully examined among patients with heart failure. Residents from 11 southeast Minnesota counties with a first-ever International Classification of Diseases, Ninth Revision ( ICD-9 ) code 428 for heart failure between January 1, 2013, and March 31, 2015 (N=3867), were prospectively surveyed to measure perceived social isolation. A total of 2003 patients returned the survey (response rate, 52%); 1681 patients completed all questions and were retained for analysis. Among these patients (53% men; mean age, 73 years), ≈19% (n=312) had moderate perceived social isolation and 6% (n=108) had high perceived social isolation. After adjustment, patients reporting moderate perceived social isolation did not have an increased risk of death, hospitalizations, or emergency department visits compared with patients reporting low perceived social isolation; however, patients reporting high perceived social isolation had >3.5 times increased risk of death (hazard ratio, 3.74; 95% confidence interval [CI], 1.82-7.70), 68% increased risk of hospitalization (hazard ratio, 1.68; 95% CI, 1.18-2.39), and 57% increased risk of emergency department visits (hazard ratio, 1.57; 95% CI, 1.09-2.27). Compared with patients who self-reported low perceived social isolation, patients reporting moderate perceived social isolation had a 16% increased risk of outpatient visits (rate ratio, 1.16; 95% CI, 1.03-1.31), whereas those reporting high perceived social isolation had a 26% increased risk (rate ratio, 1.26; 95% CI, 1.04-1.53). In patients with heart failure, greater perceived social isolation is associated with an increased risk of death and healthcare use. Assessing perceived social isolation during the clinical encounter with a brief screening tool may help identify patients with heart failure at greater risk of poor outcomes. �

EFFECT OF HIGHLY ACTIVE ANTIRETROVIRAL THERAPY ON VAGINAL Candida spp. ISOLATION IN HIV-INFECTED COMPARED TO HIV-UNINFECTED WOMEN

Directory of Open Access Journals (Sweden)

Silvia de Souza Dantas ALCZUK

2015-04-01

Full Text Available Vulvovaginal candidiasis (VVC in HIV-infected women contributed to the impairment of their quality of life. The aim of this study was to evaluate the effect of highly active antiretroviral therapy (HAART use on the vaginal Candida spp. isolation in HIV-infected compared to HIV-uninfected women. This cross-sectional study included 178 HIV-infected (HIV group and 200 HIV-uninfected women (control that were studied at the Specialized Assistance Service (SAE for sexually transmitted diseases (STD/AIDS of the city of Maringá, Brazil, from April 1 to October 30, 2011. The yeasts were isolated and identified by phenotypic and molecular methods. The in vitro antifungal susceptibility to fluconazole, itraconazole, nystatin and amphotericin B was tested by the reference microdilution method. Higher frequencies of total vaginal Candida spp. isolation were found in the HIV-infected group than in the control group. However, both groups showed a similar frequency of colonization and VVC. Although C. albicans was the most frequent and sensitive to azolics and polyenes in both HIV-infected and uninfected women, the emerging resistance of C. glabrata to amphotericin B in the HIV-infected women was observed. Although higher frequency of vaginal Candida spp. isolation had been observed in the HIV-infected than in HIV-uninfected women, colonization and VVC showed similar frequency in both groups, indicating that HAART appears to protect against vaginal colonization and VVC.

Isolation and determination of cultural characteristics of a new highly CO2 tolerant fresh water microalgae

International Nuclear Information System (INIS)

Yue Lihong; Chen Weigong

2005-01-01

Fresh water microalgae, which has high CO 2 tolerance, were isolated and its cultural characteristics were investigated. The ZY-1 strain was identified as genus Chlorella. It showed maximum growth at 10% (v/v) CO 2 enriched air flowing condition, and a good growth rate in a broad range of physically controllable conditions, including CO 2 concentration up to 70% (v/v), CO 2 enriched air flow rate, temperature and pH value. The results indicated the feasibility of the ZY-1 strain for fixing CO 2 from stack gases

Numerical Solutions for Nonlinear High Damping Rubber Bearing Isolators: Newmark’s Method with Netwon-Raphson Iteration Revisited

Directory of Open Access Journals (Sweden)

Markou A.A.

2018-03-01

Full Text Available Numerical methods for the solution of dynamical problems in engineering go back to 1950. The most famous and widely-used time stepping algorithm was developed by Newmark in 1959. In the present study, for the first time, the Newmark algorithm is developed for the case of the trilinear hysteretic model, a model that was used to describe the shear behaviour of high damping rubber bearings. This model is calibrated against free-vibration field tests implemented on a hybrid base isolated building, namely the Solarino project in Italy, as well as against laboratory experiments. A single-degree-of-freedom system is used to describe the behaviour of a low-rise building isolated with a hybrid system comprising high damping rubber bearings and low friction sliding bearings. The behaviour of the high damping rubber bearings is simulated by the trilinear hysteretic model, while the description of the behaviour of the low friction sliding bearings is modeled by a linear Coulomb friction model. In order to prove the effectiveness of the numerical method we compare the analytically solved trilinear hysteretic model calibrated from free-vibration field tests (Solarino project against the same model solved with the Newmark method with Netwon-Raphson iteration. Almost perfect agreement is observed between the semi-analytical solution and the fully numerical solution with Newmark’s time integration algorithm. This will allow for extension of the trilinear mechanical models to bidirectional horizontal motion, to time-varying vertical loads, to multi-degree-of-freedom-systems, as well to generalized models connected in parallel, where only numerical solutions are possible.

Seismic isolation design guidelines for KALIMER(Revision A)

International Nuclear Information System (INIS)

Yoo, B; Koo, Gyeong Hoi; Lee, J. H.

2000-04-01

The main purpose of this report is to develop the seismic isolation design guideline for KALIMER(Korea Advanced LIquid MEtal Reactor). The proposed design rules(revision A) are only applicable to the seismic isolation design with using the high damping laminated rubber bearings. When using other seismic isolation devices and applying to 3-dimensional isolation, the proposed guidelines shall be modified and added with proper research data. The rules described in this report are based on the research results performed up to now but needed to be upgraded and verified with more detail research works for the future

Isolation barriers between petunia axillaris and Petunia integrifolia (Solanaceae).

Science.gov (United States)

Dell'olivo, Alexandre; Hoballah, Maria Elena; Gübitz, Thomas; Kuhlemeier, Cris

2011-07-01

The isolation barriers restricting gene flow between populations or species are of crucial interest for understanding how biological species arise and how they are maintained. Few studies have examined the entire range of possible isolation barriers from geographic isolation to next generation hybrid viability. Here, we present a detailed analysis of isolation barriers between two flowering plant species of the genus Petunia (Solanaceae). Petunia integrifolia and P. axillaris feature divergent pollination syndromes but can produce fertile hybrids when crossed in the laboratory. Both Petunia species are primarily isolated in space but appear not to hybridize in sympatry. Our experiments demonstrate that pollinator isolation is very high but not strong enough to explain the absence of hybrids in nature. However, pollinator isolation in conjunction with male gametic isolation (i.e., pollen-pistil interaction) can explain the lack of natural hybridization, while postzygotic isolation barriers are low or nonexistent. Our study supports the notion that reproductive isolation in flowering plants is mainly caused by pre- rather than postzygotic isolation mechanisms. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Experiments on seismic isolation in Italy

International Nuclear Information System (INIS)

Bonacina, G.; Bettinali, F.; Martelli, A.; Olivieri, M.

1992-01-01

Static and dynamic tests have been performed in Italy on high damping steel-laminated elastomer bearings in various scales, rubber specimens and structures isolated by means of such bearings, in the framework of studies in progress to support seismic isolation development. Tests on rubber specimens and bearings have already provided important data (vertical and horizontal stiffness, damping, creep, temperature, aging and scale effects, etc.), necessary for the development and validation of numerical models, comparison with the test results of isolated structure mockups and actual buildings, and improvement of design guidelines. Dynamic experiments of structures concerned both full-scale and scaled isolated structure mock-ups and actual isolated buildings (one of those forming the SIP Administration Center at Ancona, an isolated house at Squillace, Calabria). Both snap-back tests and forced excitation experiments were performed, to rather large displacements. The latter were both sinusoidal and (on a 1/4 scale mock-up) seismic, with one- and multidirectional simultaneous excitations. Test results have already demonstrated the adequacy of seismic isolation and have provided data useful for the comparison with single bearing test results and validation of numerical models for the analysis of isolated structures. This paper reports the main features and results of tests performed or in progress. Further tests planned have been mentioned in the Status Report. Numerical analysis of measured data and guidelines development have been discussed in separate technical papers. (author)

Antibiotic resistance of Verotoxigenic Escherichia coli isolated from vegetables

Directory of Open Access Journals (Sweden)

mojtaba boniadian

2017-01-01

Full Text Available Introduction: Human gastrointestinal disease caused by verotoxigenic Escherichia coli has been diagnosed for recent decades. Escherichia coli O157:H7 is the most important serotype of verotoxigenic Escherichia coli that cause hemolytic uremic syndrome and hemorrhagic colitis in humans. This study was conducted to determine the occurrence of verotoxigenic E. coli and antibiotic resistance of the isolates from vegetables. Materials and methods: A total of 500 fresh vegetable samples were collected randomly from retail shops in Shahrekord, Iran. E. coli was isolated and identified using bacteriological and biochemical tests. PCR method was used to identify the rbfE, stx1, stx2 and eae genes. Also, antibiotic resistance of the isolates was determined by disk diffusion method. Results: The results represented that among 25 isolates possess virulence genes, 40, 12 and 4% of the isolates contained eaeA, STx2, and both genes, respectively. But none of them contained H7, STx1, and rfbE genes. The antibiotic resistance pattern demonstrated that the isolates were highly resistant to Gentamycin and cefotoxime. Discussion and conclusion: The results of this study showed that the presence of verotoxigenic E.coli in vegetables; and high resistance of the isolates to antibiotics could be hazardous for public health.

Demequina lutea sp. nov., isolated from a high Arctic permafrost soil

DEFF Research Database (Denmark)

Finster, Kai; Herbert, Rodney Andrew; Kjeldsen, Kasper Urup

2009-01-01

Two Gram-stain-positive, pigmented, non-motile, non-spore-forming, pleomorphic, rod-shaped bacteria (strains SV45T and SV47), isolated from a permafrost soil collected from the Adventdalen valley, Spitsbergen, northern Norway, have been characterized taxonomically using a polyphasic approach...

Isolating GaSb membranes grown metamorphically on GaAs substrates using highly selective substrate removal etch processes

Energy Technology Data Exchange (ETDEWEB)

Lavrova, Olga [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Electrical and Computer Engineering. Center for High Technology Materials; Balakrishnan, Ganesh [Univ. of New Mexico, Albuquerque, NM (United States). Dept. of Electrical and Computer Engineering. Center for High Technology Materials

2017-02-24

The etch rates of NH₄OH:H₂O₂ and C₆H₈O₇:H₂O₂ for GaAs and GaSb have been investigated to develop a selective etch for GaAs substrates and to isolate GaSb epilayers grown on GaAs. The NH₄OH:H₂O₂ solution has a greater etch rate differential for the GaSb/GaAs material system than C₆H₈O₇:H₂O₂ solution. The selectivity of NH₄OH:H₂O₂ for GaAs/GaSb under optimized etch conditions has been observed to be as high as 11471 ± 1691 whereas that of C₆H₈O₇:H₂O₂ has been measured up to 143 ± 2. The etch contrast has been verified by isolating 2 μm thick GaSb epi-layers that were grown on GaAs substrates. GaSb membranes were tested and characterized with high-resolution X-Ray diffraction (HR-XRD) and atomic force microscopy (AFM).

Secure Enclaves: An Isolation-centric Approach for Creating Secure High Performance Computing Environments

Energy Technology Data Exchange (ETDEWEB)

Aderholdt, Ferrol [Tennessee Technological Univ., Cookeville, TN (United States); Caldwell, Blake A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hicks, Susan Elaine [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Koch, Scott M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Naughton, III, Thomas J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pelfrey, Daniel S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Pogge, James R [Tennessee Technological Univ., Cookeville, TN (United States); Scott, Stephen L [Tennessee Technological Univ., Cookeville, TN (United States); Shipman, Galen M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sorrillo, Lawrence [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2017-01-01

High performance computing environments are often used for a wide variety of workloads ranging from simulation, data transformation and analysis, and complex workflows to name just a few. These systems may process data at various security levels but in so doing are often enclaved at the highest security posture. This approach places significant restrictions on the users of the system even when processing data at a lower security level and exposes data at higher levels of confidentiality to a much broader population than otherwise necessary. The traditional approach of isolation, while effective in establishing security enclaves poses significant challenges for the use of shared infrastructure in HPC environments. This report details current state-of-the-art in virtualization, reconfigurable network enclaving via Software Defined Networking (SDN), and storage architectures and bridging techniques for creating secure enclaves in HPC environments.

Kinetics of microstructure formation of high-pressure induced gel from a whey protein isolate

Energy Technology Data Exchange (ETDEWEB)

He Jinsong; Yang Hongwei; Zhu Wanpeng [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Mu Taihua, E-mail: mutaihuacaas@126.co [Institute of Agro-Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing 100094 (China)

2010-03-01

The kinetic process of pressure-induced gelation of whey protein isolate (WPI) solutions was studied using in situ light scattering. The relationship of the logarithm of scattered light intensity (I) versus time (t) was linear after the induced time and could be described by the Cahn-Hilliard linear theory. With increasing time, the scattered intensity deviated from the exponential relationship, and the time evolution of the scattered light intensity maximum I{sub m} and the corresponding wavenumber q{sub m} could be described in terms of the power-law relationship as I{sub m}{approx}f{sup {beta}} and q{sub m}{approx}f{sup -}{alpha}, respectively. These results indicated that phase separation occurred during the gelation of WPI solutions under high pressure.

Toxigenic potential of Fusarium graminearum isolated from maize of northwest Argentina

Directory of Open Access Journals (Sweden)

D.A. Sampietro

2013-01-01

Full Text Available Twenty six isolates of Fusarium graminearum from grains of maize hybrids harvested in ±west Argentina were grown on autoclaved rice grain to assess their ability to produce type B trichothecenes. Chemical analysis indicated that 38% of isolates were nivalenol (NIV producers only, 31% were major NIV producers with high DON(deoxynivalenol/NIV ratios, 8% were major DON producers with minor NIV production, and 23% were DON producers only. Isolates showed a high variability in their toxigenic potential which was not related to fungal biomass. The distribution of the different chemotypes as well as the high and the low trichothecene-producing Fusarium isolates could not be associated to a geographical origin. Our results confirmed for the first time that isolates of Fusarium graminearum from maize of northwest Argentina are able to produce DON and NIV. A substancial contamination with both NIV and DON is likely in maize from northwest Argentina. Their contents should be quantified in regional surveillances for mycotoxin contamination.

Isolation and characterization of a novel nitrobenzene-degrading bacterium with high salinity tolerance: Micrococcus luteus.

Science.gov (United States)

Zheng, Chunli; Qu, Baocheng; Wang, Jing; Zhou, Jiti; Wang, Jing; Lu, Hong

2009-06-15

Strain Z3 was isolated from nitrobenzene-contaminated sludge. Strain Z3 was able to utilize nitrobenzene as a sole source of carbon, nitrogen and energy under aerobic condition. Based on the morphology, physiological biochemical characteristics, and 16S rDNA sequence, strain Z3 was identified as Micrococcus luteus. Strain Z3 completely degraded nitrobenzene with initial concentration of 100, 150, 200, and 250 mg L(-1) within 70, 96, 120 and 196 h, respectively. Kinetics of nitrobenzene degradation was described using the Andrews equation. The kinetic parameters were as follows: q(max)=1.19 h(-1), K(s)=29.11 mg L(-1), and K(i)=94.00 mg L(-1). Strain Z3 had a high salinity tolerance. It degraded 200 mg L(-1) nitrobenzene completely in 5% NaCl (w/w%). Strain Z3 therefore could be an excellent candidate for the bio-treatment of nitrobenzene industrial wastewaters with high salinity. This is the first report on the degradation of nitrobenzene by M. luteus and the degradation of nitrobenzene achieved in such a high salinity.

Isolation of high-quality total RNA from rumen anaerobic bacteria and fungi, and subsequent detection of glycoside hydrolases.

Science.gov (United States)

Wang, Pan; Qi, Meng; Barboza, Perry; Leigh, Mary Beth; Ungerfeld, Emilio; Selinger, L Brent; McAllister, Tim A; Forster, Robert J

2011-07-01

The rumen is one of the most powerful fibrolytic fermentation systems known. Gene expression analyses, such as reverse transcription PCR (RT-PCR), microarrays, and metatranscriptomics, are techniques that could significantly expand our understanding of this ecosystem. The ability to isolate and stabilize representative RNA samples is critical to obtaining reliable results with these procedures. In this study, we successfully isolated high-quality total RNA from the solid phase of ruminal contents by using an improved RNA extraction method. This method is based on liquid nitrogen grinding of whole ruminal solids without microbial detachment and acid guanidinium - phenol - chloroform extraction combined with column purification. Yields of total RNA were as high as 150 µg per g of fresh ruminal content. The typical large subunit/small subunit rRNA ratio ranged from 1.8 to 2.0 with an RNA integrity number (Agilent Technologies) greater than 8.5. By eliminating the detachment step, the resulting RNA was more representative of the complete ecosystem. Our improved method removed a major barrier limiting analysis of rumen microbial function from a gene expression perspective. The polyA-tailed eukaryotic mRNAs obtained have successfully been applied to next-generation sequencing, and metatranscriptomic analysis of the solid fraction of rumen contents revealed abundant sequences related to rumen fungi.

High potential of adhesion to biotic and abiotic surfaces by opportunistic Staphylococcus aureus strains isolated from orthodontic appliances.

Science.gov (United States)

Merghni, Abderrahmen; Ben Nejma, Mouna; Dallel, Ines; Tobji, Samir; Ben Amor, Adel; Janel, Sébastien; Lafont, Frank; Aouni, Mahjoub; Mastouri, Maha

2016-02-01

Orthodontic and other oral appliances act as reservoir of opportunistic pathogens that can easily become resistant to antibiotics and cause systemic infections. The aim of this study was to investigate the ability of Staphylococcus aureus strains isolated from healthy patients with orthodontic appliances, to adhere to biotic (HeLa cells) and abiotic surfaces (polystyrene and dental alloy). Adhesive ability to polystyrene was tested by crystal violet staining and quantitative biofilm production on dental alloy surfaces was evaluated by MTT reduction assay. In addition, the presence of icaA and icaD genes was achieved by polymerase chain reaction (PCR). Qualitative biofilm production revealed that 70.6% of strains were slime producers. The metabolic activity of S. aureus biofilms on dental alloy surfaces was high and did not differ between tested strains. Moreover, all the isolates were adhesive to HeLa cells and 94% of them harbor icaA and icaD genes. Considerable adhesion and internalization capacity to the epithelial HeLa cells and strong biofilm production abilities together, with a high genotypic expression of icaA/icaD genes are an important equipment of S. aureus to colonize orthodontic appliances and eventually to disseminate towards other body areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

A safe inexpensive method to isolate high quality plant and fungal ...

African Journals Online (AJOL)

The most commonly used plant DNA isolation methods use toxic and hazardous chemicals (phenol, chloroform), which require special equipment to minimize exposure and may limit their use in certain environments. Commercial DNA extraction kits are convenient and usually safe, but their availability to certain developing ...

Extracellular Xylanolytic and Pectinolytic Hydrolase Production by Aspergillus flavus Isolates Contributes to Crop Invasion

Directory of Open Access Journals (Sweden)

Jay E. Mellon

2015-08-01

Full Text Available Several atoxigenic Aspergillus flavus isolates, including some being used as biocontrol agents, and one toxigenic isolate were surveyed for the ability to produce extracellular xylanolytic and pectinolytic hydrolases. All of the tested isolates displayed good production of endoxylanases when grown on a medium utilizing larch xylan as a sole carbon substrate. Four of the tested isolates produced reasonably high levels of esterase activity, while the atoxigenic biocontrol agent NRRL 21882 isolate esterase level was significantly lower than the others. Atoxigenic A. flavus isolates 19, 22, K49, AF36 (the latter two are biocontrol agents and toxigenic AF13 produced copious levels of pectinolytic activity when grown on a pectin medium. The pectinolytic activity levels of the atoxigenic A. flavus 17 and NRRL 21882 isolates were significantly lower than the other tested isolates. In addition, A. flavus isolates that displayed high levels of pectinolytic activity in the plate assay produced high levels of endopolygalacturonase (pectinase P2c, as ascertained by isoelectric focusing electrophoresis. Isolate NRRL 21882 displayed low levels of both pectinase P2c and pectin methyl esterase. A. flavus appears capable of producing these hydrolytic enzymes irrespective of aflatoxin production. This ability of atoxigenic isolates to produce xylanolytic and pectinolytic hydrolases mimics that of toxigenic isolates and, therefore, contributes to the ability of atoxigenic isolates to occupy the same niche as A. flavus toxigenic isolates.

Survival of marine heterotrophic flagellates isolated from the surface and the deep sea at high hydrostatic pressure: Literature review and own experiments

Science.gov (United States)

Živaljić, Suzana; Schoenle, Alexandra; Nitsche, Frank; Hohlfeld, Manon; Piechocki, Julia; Reif, Farina; Shumo, Marwa; Weiss, Alexandra; Werner, Jennifer; Witt, Madeleine; Voss, Janine; Arndt, Hartmut

2018-02-01

Although the abyssal seafloor represents the most common benthic environment on Earth, eukaryotic microbial life at abyssal depths is still an uncharted territory. This is in striking contrast to their potential importance regarding the material flux and bacteria consumption in the deep sea. Flagellate genotypes determined from sedimentary DNA deep-sea samples might originate from vital deep-sea populations or from cysts of organisms sedimented down from surface waters. The latter one may have never been active under deep-sea conditions. We wanted to analyze the principal ability of cultivable heterotrophic flagellates of different phylogenetic groups (choanoflagellates, ancyromonads, euglenids, kinetoplastids, bicosoecids, chrysomonads, and cercozoans) to survive exposure to high hydrostatic pressure (up to 670 bar). We summarized our own studies and the few available data from literature on pressure tolerances of flagellates isolated from different marine habitats. Our results demonstrated that many different flagellate species isolated from the surface waters and deep-sea sediments survived drastic changes in hydrostatic pressure. Barophilic behavior was also recorded for several species isolated from the deep sea indicating their possible genetic adaptation to high pressures. This is in accordance with records of heterotrophic flagellates present in environmental DNA surveys based on clone libraries established for deep-sea environments.

Good quality Vitis RNA obtained from an adapted DNA isolation protocol

Directory of Open Access Journals (Sweden)

Isabel Baiges

2003-03-01

Full Text Available Grapevine is a woody plant, whose high carbohydrate and phenolic compound contents usually interferes with nucleic acid isolation. After we tried several protocols for isolating RNA from the Vitis rootstock Richter- 110 (R-110 with little or no success, we adapted a method reported to be satisfactory for grapevine DNA isolation, to extract RNA. With slight protocol modifications, we succeeded to obtain polysaccharide- and phenolic-free RNA preparations from all vegetative tissues, without excessive sample handling. RNA isolated by the reported method permitted to obtain highly pure mRNA (messenger RNA to construct a cDNA (complementary DNA library and allowed gene transcription analysis by reverse Northern, which guarantees RNA integrity. This method may also be suitable for other plant species with high polysaccharide or phenolic contents.

Evaluation of prevalence of low and high level mupirocin resistance in methicillin resistant staphylococcus aureus isolates at a tertiary care hospital

International Nuclear Information System (INIS)

Nizamuddin, S.; Irfan, S.; Zafar, A.

2011-01-01

To evaluate the trend of mupirocin resistance in MRSA, isolated at the Clinical Microbiology Laboratory of a tertiary care hospital. Methods: A total of 200 MRSA strains recovered over a 2 year period from various body sites were tested using the 5 and 200 mu g discs of mupirocin to detect its resistance. Results: High level and low level mupirocin resistance were detected in zero and 1 % of MRSA strains, respectively. Resistance to other non beta lactam antibiotics was also high. No MRSA strains were found to be resistant to vancomycin and tegicycline. Conclusion: Mupirocin resistance was found to be very low among local clinical isolates of MRSA. Its judicious use to decolonize nasal carriers should be promoted among hospitalized patients to avoid further transmission and infections due to prevalent endemic MRSA strains in any health care setting. Concomitantly, regular surveillance and effective infection control initiatives are desirable to reduce the incidence of health care associated infections due to MRSA and also of mupirocin resistance. (author)

Cavitation enhances coagulated size during pulsed high-intensity focussed ultrasound ablation in an isolated liver perfusion system.

Science.gov (United States)

Zhao, Lu-Yan; Liu, Shan; Chen, Zong-Gui; Zou, Jian-Zhong; Wu, Feng

2016-11-24

To investigate whether cavitation enhances the degree of coagulation during pulsed high-intensity focussed ultrasound (HIFU) in an isolated liver perfusion system. Isolated liver was treated by pulsed HIFU or continuous-wave HIFU with different portal vein flow rates. The cavitation emission during exposure was recorded, and real-time ultrasound images were used to observe changes in the grey scale. The coagulation size was measured and calculated. HIFU treatment led to complete coagulation necrosis and total cell destruction in the target regions. Compared to exposure at a duty cycle (DC) of 100%, the mean volumes of lesions induced by 6 s exposure at DCs of 50% and 10% were significantly larger (P cavitation activity for the pulsed-HIFU (P > .05). For continuous-wave HIFU exposure, there was a significant decrease in the necrosis volume and cavitation activity for exposure times of 1, 2, 3, 4, and 6 s with increasing portal perfusion rates. Perfusion flow rates negatively influence cavitation activity and coagulation volume. Ablation is significantly enhanced during pulsed HIFU exposure compared with continuous-wave HIFU.

Isolated galaxies

International Nuclear Information System (INIS)

Einasto, Maret

1990-01-01

To test for the possible presence of really isolated galaxies, which form a randomly distributed population in voids, we compare the distribution of most isolated galaxies in an observed sample with distributions of the same number of random points using the nearest neighbour test. The results show that the random population of really isolated galaxies does not exist - even the most isolated galaxies are connected with systems of galaxies, forming their outlying parts. (author)

Screening concepts for the isolation of biosurfactant producing microorganisms.

Science.gov (United States)

Walter, Vanessa; Syldatk, Christoph; Hausmann, Rudolf

2010-01-01

This chapter gives an overview of current methods for the isolation of biosurfactant producing microbes. The common screening methods for biosurfactants are presented. Sampling and isolation of bacteria are the basis for screening of biosurfactant producing microbes. Hydrocarbon-contaminated sites are the most promising for the isolation of biosurfactant producing microbes, but many strains have also been isolated from undisturbed sites. In subsequent steps the isolates have to be characterized in order to identify the strains which are interesting for a further investigation. Several techniques have been developed for identifying biosurfactant producing strains. Most of them are directly based on the surface or interfacial activity of the culture supernatant. Apart from that, some screening methods explore the hydrophobicity of the cell surface. This trait also gives an indication on biosurfactant production. In recent years automation and miniaturization have led to the development of high throughput methods for screening. High throughput screening (HTS) for analyzing large amounts of potential candidates or whole culture collections is reflected in the end. However, no new principals have been introduced by HTS methods.

Heat resistance of thermoduric enterococci isolated from milk.

Science.gov (United States)

McAuley, Catherine M; Gobius, Kari S; Britz, Margaret L; Craven, Heather M

2012-03-15

Enterococci are reported to survive pasteurisation but the extent of their survival is unclear. Sixty-one thermoduric enterococci isolates were selected from laboratory pasteurised milk obtained from silos in six dairy factories. The isolates were screened to determine log(10) reductions incurred after pasteurisation (63°C/30 min) and ranked from highest to lowest log(10) reduction. Two isolates each of Enterococcus faecalis, Enterococcus faecium, Enterococcus durans and Enterococcus hirae, exhibiting the median and the greatest heat resistance, as well as E. faecalis ATCC 19433, were selected for further heat resistance determinations using an immersed coil apparatus. D values were calculated from survival curves plotted from viable counts obtained after heating isolates in Brain Heart Infusion Broth at 63, 69, 72, 75 and 78°C followed by rapid cooling. At 72°C, the temperature employed for High Temperature Short Time (HTST) pasteurisation (72°C/15s), the D values extended from 0.3 min to 5.1 min, depending on the isolate and species. These data were used to calculate z values, which ranged from 5.0 to 9.8°C. The most heat sensitive isolates were E. faecalis (z values 5.0, 5.7 and 7.5°C), while the most heat resistant isolates were E. durans (z values 8.7 and 8.8°C), E. faecium (z value 9.0°C) and E. hirae (z values 8.5 and 9.8°C). The data show that heat resistance in enterococci is highly variable. Copyright © 2011 Elsevier B.V. All rights reserved.

A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability

Science.gov (United States)

Wang, Qi; Hou, Yubin; Wang, Junting; Lu, Qingyou

2013-11-01

We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d31 coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices.

A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability

International Nuclear Information System (INIS)

Wang, Qi; Wang, Junting; Lu, Qingyou; Hou, Yubin

2013-01-01

We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d 31 coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices

A high-stability scanning tunneling microscope achieved by an isolated tiny scanner with low voltage imaging capability.

Science.gov (United States)

Wang, Qi; Hou, Yubin; Wang, Junting; Lu, Qingyou

2013-11-01

We present a novel homebuilt scanning tunneling microscope (STM) with high quality atomic resolution. It is equipped with a small but powerful GeckoDrive piezoelectric motor which drives a miniature and detachable scanning part to implement coarse approach. The scanning part is a tiny piezoelectric tube scanner (industry type: PZT-8, whose d31 coefficient is one of the lowest) housed in a slightly bigger polished sapphire tube, which is riding on and spring clamped against the knife edges of a tungsten slot. The STM so constructed shows low back-lashing and drifting and high repeatability and immunity to external vibrations. These are confirmed by its low imaging voltages, low distortions in the spiral scanned images, and high atomic resolution quality even when the STM is placed on the ground of the fifth floor without any external or internal vibration isolation devices.

prevalence and antifungal susceptibility of candida species isolated

African Journals Online (AJOL)

User

Candida species isolated from HVS specimens were Candida albicans (n=19, 48.7%), Can- dida glabrata .... C test kits. The isolates were stored ... problem that causes significant morbidity and affects the .... from both urinary and high vaginal specimens followed by ... drugs that are used in the treatment of infec- tions due ...

EMPLACEMENT DRIFT ISOLATION DOOR CONTROL SYSTEM

International Nuclear Information System (INIS)

N.T. Raczka

1998-01-01

The purpose of this analysis is to review and refine key design concepts related to the control system presently under consideration for remotely operating the emplacement drift isolation doors at the potential subsurface nuclear waste repository at Yucca Mountain. This analysis will discuss the key design concepts of the control system that may be utilized for remotely monitoring, opening, and closing the emplacement drift isolation doors. The scope and primary objectives of this analysis are to: (1) Discuss the purpose and function of the isolation doors (Presented in Section 7.1). (2) Review the construction of the isolation door and other physical characteristics of the doors that the control system will interface with (Presented in Section 7.2). (3) Discuss monitoring and controlling the operation of the isolation doors with a digital control system (either a Programmable Logic Controller (PLC) system or a Distributed Control System (DCS)) (Presented in Section 7.3). (4) Discuss how all isolation doors can be monitored and controlled from a subsurface central control center (Presented in Section 7.4). This analysis will focus on the development of input/output (I/O) counts including the types of I/O, redundancy and fault tolerance considerations, and processor requirements for the isolation door control system. Attention will be placed on operability, maintainability, and reliability issues for the system operating in the subsurface environment with exposure to high temperatures and radiation

"I Feel Trapped": The Tension Between Personal and Structural Factors of Social Isolation and the Desire for Social Integration Among Older Residents of a High-Crime Neighborhood.

Science.gov (United States)

Portacolone, Elena; Perissinotto, Carla; Yeh, Jarmin Christine; Greysen, S Ryan

2018-01-18

The aim of this study was to examine the factors contributing to the social isolation of older residents of a high-crime neighborhood through the in-depth examination of their lived experiences. A deeper understanding of factors contributing to social isolation can allow policymakers and health care providers to create policies and programs to alleviate the social isolation of these vulnerable and understudied individuals. Participants were recruited through the support of the Housing Authority and Police and Fire Departments of Richmond, California, a town with a high-crime rate. Fifty-nine ethnographic interviews were conducted with 20 individuals of 58-95 years of age. Transcripts and fieldnotes were analyzed with a focus on the specific factors contributing the social isolation of participants. An overarching theme of tension between personal and structural factors of social isolation and desire for social integration emerged from qualitative content analysis. A tension emerged between a longing to participate in society and the immersion in a reality so dense with obstacles that made participation in society difficult to attain. Four specific themes also emerged. Three themes demonstrated underlying factors of social isolation stemming from the personal sphere and the physical and social environment. The fourth theme illustrated participants' desire for social integration. Findings demonstrate the salience of interventions and programs to make neighborhoods safe and accessible to older residents. Findings also suggest a need to reframe the conceptual framework for social isolation to better measure and alleviate this public health problem. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A reliable protocol for the isolation of viable, chondrogenically differentiated human mesenchymal stem cells from high-density pellet cultures.

Science.gov (United States)

Ullah, Mujib; Hamouda, Houda; Stich, Stefan; Sittinger, Michael; Ringe, Jochen

2012-12-01

Administration of chondrogenically differentiated mesenchymal stem cells (MSC) is discussed as a promising approach for the regenerative treatment of injured or diseased cartilage. The high-density pellet culture is the standard culture for chondrogenic differentiation, but cells in pellets secrete extracellular matrix (ECM) that they become entrapped in. Protocols for cell isolation from pellets often result in cell damage and dedifferentiation towards less differentiated MSC. Therefore, our aim was to develop a reliable protocol for the isolation of viable, chondrogenically differentiated MSC from high-density pellet cultures. Human bone marrow MSC were chondrogenically stimulated with transforming growth factor-β3, and the cartilaginous structure of the pellets was verified by alcian blue staining of cartilage proteoglycans, antibody staining of cartilage collagen type II, and quantitative real-time reverse-transcription polymerase chain reaction of the marker genes COL2A1 and SOX9. Trypsin and collagenases II and P were tested alone or in combination, and for different concentrations and times, to find a protocol for optimized pellet digestion. Whereas trypsin was not able to release viable cells, 90-min digestion with 300 U of collagenase II, 20 U of collagenase P, and 2 mM CaCl2 worked quite well and resulted in about 2.5×10(5) cells/pellet. The protocol was further optimized for the separation of released cells and ECM from each other. Cells were alcian blue and collagen type II positive and expressed COL2A1 and SOX9, verifying a chondrogenic character. However, they had different morphological shapes. The ECM was also uniformly alcian blue and collagen type II positive but showed different organizational and structural forms. To conclude, our protocol allows the reliable isolation of a defined number of viable, chondrogenically differentiated MSC from high-density pellet cultures. Such cells, as well as the ECM components, are of interest as

High-fat diet-induced insulin resistance does not increase plasma anandamide levels or potentiate anandamide insulinotropic effect in isolated canine islets.

Science.gov (United States)

Woolcott, Orison O; Richey, Joyce M; Kabir, Morvarid; Chow, Robert H; Iyer, Malini S; Kirkman, Erlinda L; Stefanovski, Darko; Lottati, Maya; Kim, Stella P; Harrison, L Nicole; Ionut, Viorica; Zheng, Dan; Hsu, Isabel R; Catalano, Karyn J; Chiu, Jenny D; Bradshaw, Heather; Wu, Qiang; Kolka, Cathryn M; Bergman, Richard N

2015-01-01

Obesity has been associated with elevated plasma anandamide levels. In addition, anandamide has been shown to stimulate insulin secretion in vitro, suggesting that anandamide might be linked to hyperinsulinemia. To determine whether high-fat diet-induced insulin resistance increases anandamide levels and potentiates the insulinotropic effect of anandamide in isolated pancreatic islets. Dogs were fed a high-fat diet (n = 9) for 22 weeks. Abdominal fat depot was quantified by MRI. Insulin sensitivity was assessed by the euglycemic-hyperinsulinemic clamp. Fasting plasma endocannabinoid levels were analyzed by liquid chromatography-mass spectrometry. All metabolic assessments were performed before and after fat diet regimen. At the end of the study, pancreatic islets were isolated prior to euthanasia to test the in vitro effect of anandamide on islet hormones. mRNA expression of cannabinoid receptors was determined in intact islets. The findings in vitro were compared with those from animals fed a control diet (n = 7). Prolonged fat feeding increased abdominal fat content by 81.3±21.6% (mean±S.E.M, Pcanines, high-fat diet-induced insulin resistance does not alter plasma anandamide levels or further potentiate the insulinotropic effect of anandamide in vitro.

Isolation and Identification of Spoilage Fungi Associated With Rice ...

African Journals Online (AJOL)

The spoilage fungi isolated were Aspergillus species, Rhizopus, Penicilluim, Fusarium, Eurotium, Mucor, Geotrichum, Alternaria, Cladosporium and Actinomyces species. The predominant spoilage fungi in the grains were Aspergillus species. The populations of some spoilage fungi isolated from the grains were not high ...

High Radiation Tolerant Ceramic Voltage Isolator (Non-optical Gate Driver), Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The goal of the Phase I effort is to design, develop and demonstrate a novel solid-state ceramic-based voltage isolator and demonstrate its potential to provide a...

Ocular TRUST: nationwide antimicrobial susceptibility patterns in ocular isolates.

Science.gov (United States)

Asbell, Penny A; Colby, Kathryn A; Deng, Sophie; McDonnell, Peter; Meisler, David M; Raizman, Michael B; Sheppard, John D; Sahm, Daniel F

2008-06-01

Ocular Tracking Resistance in U.S. Today (TRUST) annually evaluates in vitro antimicrobial susceptibility of Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae to ciprofloxacin, gatifloxacin, levofloxacin, moxifloxacin, penicillin, azithromycin, tobramycin, trimethoprim, and polymyxin B in national samples of ocular isolates. Laboratory investigation. Prospectively collected ocular isolates (197 S. aureus, 49 S. pneumoniae, and 32 H. influenzae) from 35 institutions and archived ocular isolates (760 S. pneumoniae and 356 H. influenzae) from 34 institutions were tested by an independent, central laboratory. Mean minimum inhibitory concentrations that would inhibit growth of 90% of the tested isolates (MIC(90)) were interpreted as susceptible, intermediate, or resistant according to standardized breakpoints for systemic treatment. S. aureus isolates were classified as methicillin susceptible (MSSA) or methicillin resistant (MRSA). MSSA or MRSA susceptibility patterns were virtually identical for the fluoroquinolones, that is, MSSA susceptibility was 79.9% to 81.1% and MRSA susceptibility was 15.2%. Trimethoprim was the only agent tested with high activity against MRSA. All S. pneumoniae isolates were susceptible to gatifloxacin, levofloxacin, and moxifloxacin; 89.8% were susceptible to ciprofloxacin. H. influenzae isolates were 100% susceptible to all tested agents but trimethoprim. Ocular TRUST 1 data were consistent with the eight-year longitudinal sample of archived ocular isolates. The fluoroquinolones were consistently active in MSSA, S. pneumoniae, and H. influenzae. After more than a decade of intensive ciprofloxacin and levofloxacin use as systemic therapy, 100% of ocular S. pneumoniae isolates were susceptible to gatifloxacin, levofloxacin, and moxifloxacin; nonsusceptibility to ciprofloxacin was less than 15%. High-level in vitro MRSA resistance suggests the need to consider alternative therapy to fluoroquinolones when MRSA is a

The current status of seismic isolation technology in the United States

International Nuclear Information System (INIS)

Kelly, J.M.

1992-01-01

Seismic isolation is at the present time in a very active state of development. Many new types of isolation systems are being explored and elastomeric isolators, the system which has been employed on almost all isolation systems completed to date, continue to undergo improvements. At least one dozen large projects, either new or the retrofit of existing buildings, have been completed and design studies are underway for at least another one dozen large projects. A large experimental research project for isolators with nuclear reactor application has been carried out over the past few years at EERC. This program has involved shake table testing and the testing of full-scale and model isolators. A wide variety of isolators have been tested including low-shape factor, moderate-shape factor, and very high-shape factor elastomer bearings. The range of elastomers that have been tested include low-damping, high-damping, and very low-modulus compounds. Full-size and model isolators have been tested to failure in several failure modes and the safety margins for isolation systems have been established. The test results have shown that properly designed and manufactured isolators for nuclear reactor applications can sustain levels of loading beyond any possible seismic input and demonstrate that failure of an isolation system cannot occur before failure of the isolated structure. Thus, the use of isolation can only have beneficial contributions to the protection of nuclear facilities, internal piping, and equipment. The presentation will review the latest developments in the implementation of base isolation and describe the results of the test program for its application to nuclear facilities. (author)

Isolation of nucleoli from Ehrlich ascites tumor cells and dynamics of nascent RNA within isolated nucleoli.

Science.gov (United States)

Thiry, Marc; Ploton, Dominique

2008-01-01

Here we describe a new, rapid method for isolating nucleoli from Ehrlich tumor cells that preserves their morphological integrity and high transcriptional activity. Until now, methods for isolation of nucleoli were generally assumed to empty one of their three main compartments, the fibrillar center, of its contents. This new method consists of sonicating cells in an isotonic medium containing MgSO(4), spermidine, and spermine, followed by separation of nucleoli through a Percoll density gradient. Using the nonisotopic approach of labelling with BrUTP, we have further investigated the dynamics of nascent ribosomal RNAs (rRNAs) within morphologically intact isolated nucleoli at the electron microscope level. We show that ribosomal transcripts are elongated in the cortex of the fibrillar center and then enter the surrounding dense fibrillar component.

First report of Tasmanian sheep strain (G2) genotype isolated from Iranian goat using the high resolution melting (HRM) analysis.

Science.gov (United States)

Hosseini-Safa, Ahmad; Mohag Hegh, Mohammad Ali; Pestechian, Nader; Ganji, Maryam; Mohammadi, Rasoul; Mahmoudi Lamouki, Reza; Rostami-Nejad, Mohammad

2016-12-01

The present study was aimed to evaluate E. granulosus genotypes isolated from goats using HRM analysis in Isfahan province. Cystic echincoccosis, so-called hydatidosis, is widespread infection caused by the larval stage of Echinococcus granulosus . This is an important zoonotic disease worldwide, especially in the developing countries such as Iran. To date, molecular studies mainly based on the mitochondrial DNA sequences have identified distinct genotypes termed G1-G10 which can differ in some characteristics such as the growth and infectivity to different intermediate hosts or the survival rate in the definitive hosts that are important for the development of control strategies. From August to December 2014, 1341 goats were investigated and hydatid cysts were collected from the liver and lungs of 43 infected goats in Isfahan province abattoirs, Isfahan, Iran. Total genomic DNA was extracted from each sample, amplified for the presence of polymorphism of mitochondrial gene coding for cytochrome c oxidase subunit 1 (CO1), using high resolution melting curve (HRM) method. the results of HRM analysis using the sequence of CO1 gene for 43 Echinococcus granulosus isolates from goats showed 31, 2 and 10 isolates were identified as G1, G2, and G3 genotypes, respectively. G1 is the predominant genotype in the isolated goat samples in Isfahan province, and the presence of G2 strain was reported for the first time in goat in Iran.

Educational Pathways to Remote Employment in Isolated Communities

Directory of Open Access Journals (Sweden)

David Denkenberger

2015-01-01

Full Text Available Those who live in isolated communities often lack reliable, skilled employment opportunities, which fundamentally undermines their human security. For individuals who wish to remain in their isolated communities for family, religious, philosophical or other reasons, their attachment to their communities creates a disincentive for higher education. This promotes low educational achievement, which in turn results in low socioeconomic status, lack of social mobility, and a generational cycle of poverty. The human misery that results from such a feedback loop is observed in isolated communities throughout North America, including aboriginal communities in Canada. Fortunately, maturation of information and communication technologies now offers individuals the potential to gain high-skilled employment while living in an isolated community, using both (i virtual work/remote work and (ii remote training and education. To examine that potential, this study: 1 categorizes high-skill careers that demand a higher education and are widely viable for remote work, 2 examines options for obtaining the required education remotely, and 3 performs an economic analysis of investing in remote education, quantifying the results in return on investment. The results show that the Internet has now opened up the possibility of both remote education and remote work. Though the investment in college education is significant, there are loans available and the return on investment is generally far higher than the interest rate on the loans. The results identified several particularly promising majors and dozens of high-income careers. The ability to both obtain an education and employment remotely offers the potential to lift many people living in isolated communities out of poverty, reduce inequality overall, and provide those living in isolated communities with viable means of employment security, which not only allows personal sustainability, but also the potential for

Isolation and mass spectrometry of transcription factor complexes.

Science.gov (United States)

Sebastiaan Winkler, G; Lacomis, Lynne; Philip, John; Erdjument-Bromage, Hediye; Svejstrup, Jesper Q; Tempst, Paul

2002-03-01

Protocols are described that enable the isolation of novel proteins associated with a known protein and the subsequent identification of these proteins by mass spectrometry. We review the basics of nanosample handling and of two complementary approaches to mass analysis, and provide protocols for the entire process. The protein isolation procedure is rapid and based on two high-affinity chromatography steps. The method does not require previous knowledge of complex composition or activity and permits subsequent biochemical characterization of the isolated factor. As an example, we provide the procedures used to isolate and analyze yeast Elongator, a histone acetyltransferase complex important for transcript elongation, which led to the identification of three novel subunits.

Bacterial microflora isolated from the bark surface of poplars growing in areas where air pollution is very high

Directory of Open Access Journals (Sweden)

Krystyna Przybył

2015-01-01

Full Text Available In the autumn of 1976 bacteria of the genera Bacillus, Pseudomonas, Flavobacterium, Erwinia and Cellulomonas were isolated from the bark surface of poplars growing in protective belts around several industrial plants. It was found that the qualitative and quantitative composition of the surface bacterial microflora changes in dependence on the degree of resistance of the poplars to the action of the dust emitted by the industrial establishment and containing high amounts of heavy metals.

Molecular Characterization of Geographically Different Banana bunchy top virus Isolates in India.

Science.gov (United States)

Selvarajan, R; Mary Sheeba, M; Balasubramanian, V; Rajmohan, R; Dhevi, N Lakshmi; Sasireka, T

2010-10-01

Banana bunchy top disease (BBTD) caused by Banana bunchy top virus (BBTV) is one of the most devastating diseases of banana and poses a serious threat for cultivars like Hill Banana (Syn: Virupakshi) and Grand Naine in India. In this study, we have cloned and sequenced the complete genome comprised of six DNA components of BBTV infecting Hill Banana grown in lower Pulney hills, Tamil Nadu State, India. The complete genome sequence of this hill banana isolate showed high degree of similarity with the corresponding sequences of BBTV isolates originating from Lucknow, Uttar Pradesh State, India, and from Fiji, Egypt, Pakistan, and Australia. In addition, sixteen coat protein (CP) and thirteen replicase genes (Rep) sequences of BBTV isolates collected from different banana growing states of India were cloned and sequenced. The replicase sequences of 13 isolates showed high degree of similarity with that of South Pacific group of BBTV isolates. However, the CP gene of BBTV isolates from Shervroy and Kodaikanal hills of Tamil Nadu showed higher amino acid sequence variability compared to other isolates. Another hill banana isolate from Meghalaya state had 23 nucleotide substitutions in the CP gene but the amino acid sequence was conserved. This is the first report of the characterization of a complete genome of BBTV occurring in the high altitudes of India. Our study revealed that the Indian BBTV isolates with distinct geographical origins belongs to the South Pacific group, except Shervroy and Kodaikanal hill isolates which neither belong to the South Pacific nor the Asian group.

Mechanism of leakage of ion-implantation isolated AlGaN/GaN MIS-high electron mobility transistors on Si substrate

Science.gov (United States)

Zhang, Zhili; Song, Liang; Li, Weiyi; Fu, Kai; Yu, Guohao; Zhang, Xiaodong; Fan, Yaming; Deng, Xuguang; Li, Shuiming; Sun, Shichuang; Li, Xiajun; Yuan, Jie; Sun, Qian; Dong, Zhihua; Cai, Yong; Zhang, Baoshun

2017-08-01

In this paper, we systematically investigated the leakage mechanism of the ion-implantation isolated AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) on Si substrate. By means of combined DC tests at different temperatures and electric field dependence, we demonstrated the following original results: (1) It is proved that gate leakage is the main contribution to OFF-state leakage of ion-implantation isolated AlGaN/GaN MIS-HEMTs, and the gate leakage path is a series connection of the gate dielectric Si3N4 and Si3N4-GaN interface. (2) The dominant mechanisms of the leakage current through LPCVD-Si3N4 gate dielectric and Si3N4-GaN interface are identified to be Frenkel-Poole emission and two-dimensional variable range hopping (2D-VRH), respectively. (3) A certain temperature annealing could reduce the density of the interface state that produced by ion implantation, and consequently suppress the interface leakage transport, which results in a decrease in OFF-state leakage current of ion-implantation isolated AlGaN/GaN MIS-HEMTs.

Relativistic thick discs in the Kerr-de Sitter backgrounds

International Nuclear Information System (INIS)

Slany, Petr; StuchlIk, Zdenek

2005-01-01

Perfect fluid tori with a uniform distribution of the specific angular momentum, l(r, θ) = const, orbiting the Kerr-de Sitter black holes or naked singularities are studied. It is well known that the structure of equipotential surfaces of such marginally stable tori reflects the basic properties of any tori with a general distribution of the specific angular momentum. Closed equipotential surfaces corresponding to stationary thick discs are allowed only in the spacetimes admitting stable circular geodesics. The last closed surface crosses itself in the cusp(s) enabling the outflow of matter from the torus due to the violation of hydrostatic equilibrium. The inner cusp enables an accretion onto the central object. The influence of the repulsive cosmological constant, Λ > 0, on the equipotential surfaces lies in the existence of the outer cusp (with a stabilizing effect on the thick discs) and in the strong collimation of open equipotential surfaces along the rotational axis. Both the effects take place near a so-called static radius where the gravitational attraction is just balanced by the cosmic repulsion. The outer cusp enables excretion, i.e., the outflow of matter from the torus into the outer space. The plus-family discs (which are always co-rotating in the black-hole backgrounds but can be counter-rotating, even with negative energy of the fluid elements, in some naked-singularity backgrounds) are thicker and more extended than the minus-family ones (which are always counter-rotating in all backgrounds). For co-rotating discs in the naked-singularity spacetimes, the potential well between the centre of the disc and its edges at the cusps is usually much higher than in the black-hole spacetimes. If the parameters of naked-singularity spacetimes are very close to the parameters of extreme black-hole spacetimes, the family of possible disc-like configurations includes members with two isolated discs where the inner one is always a counter-rotating accretion

Financial aspects of a seismic base isolation system for a steel high-rack structure

Directory of Open Access Journals (Sweden)

Kilar, V.

2013-12-01

Full Text Available The paper deals with the effects and costs of implementing a base isolation system for the mitigation of the seismic risk of an existing steel rack structure. Different realistic distributions of the payload mass and occupancy levels, which form different plan asymmetric variants, have been analysed. The results obtained by the pushover analysis (N2 method are presented as top floor envelopes and as plastic hinge damage patterns. In the presented cost study, the cost of the implementation of the proposed base isolation system is compared with the estimated costs of structural repairs to the damaged structural members of the superstructure, as well as with estimated expenses of the downtime period. The results have shown that base isolation is, in general, not economically feasible for lower ground motion intensities, whereas it could be of great benefit in the case of moderate and high intensities, especially if the downtime period is taken into account.El presente artículo trata sobre los efectos y costes de implementación de un sistema de aislamiento en cimentación para la mitigación del riesgo sísmico de la estructura de un bastidor de acero en altura prexistente. Se han analizado diferentes distribuciones realistas de la masa contribuyente y de los niveles de ocupación, conformando diferentes variantes asimétricas en planta. Se presentan los resultados obtenidos mediante el método N2 (análisis estático incremental no lineal como envolventes de las plantas superiores y como patrones de deterioro en estado plástico. En el estudio de costos presentado, el coste de implementación del sistema de aislamiento propuesto se compara con los costes estimados de reparación de los elementos superestructurales y los costes derivados del período de desocupación. Los resultados muestran que, en general, el aislamiento en la base no resulta viable económicamente para movimientos de baja intensidad, pero puede ser muy beneficioso en el caso de

VIBRATION ISOLATION SYSTEM PROBABILITY ANALYSIS

Directory of Open Access Journals (Sweden)

Smirnov Vladimir Alexandrovich

2012-10-01

Full Text Available The article deals with the probability analysis for a vibration isolation system of high-precision equipment, which is extremely sensitive to low-frequency oscillations even of submicron amplitude. The external sources of low-frequency vibrations may include the natural city background or internal low-frequency sources inside buildings (pedestrian activity, HVAC. Taking Gauss distribution into account, the author estimates the probability of the relative displacement of the isolated mass being still lower than the vibration criteria. This problem is being solved in the three dimensional space, evolved by the system parameters, including damping and natural frequency. According to this probability distribution, the chance of exceeding the vibration criteria for a vibration isolation system is evaluated. Optimal system parameters - damping and natural frequency - are being developed, thus the possibility of exceeding vibration criteria VC-E and VC-D is assumed to be less than 0.04.

Molecular characterization and phylogenetic analysis of highly pathogenic Vibrio alginolyticus strains isolated during mortality outbreaks in cultured Ruditapes decussatus juvenile.

Science.gov (United States)

Mechri, Badreddine; Monastiri, Abir; Medhioub, Amel; Medhioub, Mohamed Nejib; Aouni, Mahjoub

2017-10-01

In the summer of 2008 and 2009, a series of mortalities in growing out seeds of R. decussatus juveniles were occurred in the eastern Tunisian littoral. Nine predominant bacterial strains were isolated from dead and moribund juveniles and characterized as Vibrio alginolyticus. These isolates were subjected to biochemical and molecular characterization. All the Vibrio strains were tested for their susceptibility against the most widely used antibiotic in aquaculture as well as, the assessment of the presence of erythromycin (emrB) and tetracycline (tetS) resistance genes among the tested bacteria. The degree of genetic relatedness between V. alginolyticus strains was evaluated on the basis of the Entero-Bacterial Repetitive Intergenic Consensus (ERIC) and the Random Amplification of Polymorphic DNA-PCR (RAPD-PCR) approaches. We also looked for siderophore activity and the ability to grow under iron limitation. Furthermore, the pathogenic potential of the tested isolates was evaluated using R. decussatus larva and juveniles as infection models. On antimicrobial susceptibility test, Vibrio strains exhibited total resistance to at least four antibiotics. The MICs data revealed that flumequine and oxolinic acid were the most effective antibiotics to control the studied bacteria. Results also showed that studied antibiotics resistance genes were widely disseminated in the genome of V. alginolyticus strains. Both ERIC and RAPD-PCR fingerprinting showed the presence of genetic variation among Vibrio isolates. However, RAPD typing exhibited a higher discriminative potential than ERIC-PCR. Besides, we reported here for the first time the co-production of catechol and hydroxamte by V. alginolyticus species. The challenge experiment showed that most of Vibrio isolates caused high mortality rates for both larva and juveniles at 48-h post-exposure to a bacterial concentration of 10 6  CFU/ml. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solid-phase glycan isolation for glycomics analysis.

Science.gov (United States)

Yang, Shuang; Zhang, Hui

2012-12-01

Glycosylation is one of the most significant protein PTMs. The biological activities of proteins are dramatically changed by the glycans associated with them. Thus, structural analysis of the glycans of glycoproteins in complex biological or clinical samples is critical in correlation with the functions of glycans with diseases. Profiling of glycans by HPLC-MS is a commonly used technique in analyzing glycan structures and quantifying their relative abundance in different biological systems. Methods relied on MS require isolation of glycans from negligible salts and other contaminant ions since salts and ions may interfere with the glycans, resulting in poor glycan ionization. To accomplish those objectives, glycan isolation and clean-up methods including SPE, liquid-phase extraction, chromatography, and electrophoresis have been developed. Traditionally, glycans are isolated from proteins or peptides using a combination of hydrophobic and hydrophilic columns: proteins and peptides remain on hydrophobic absorbent while glycans, salts, and other hydrophilic reagents are collected as flowthrough. The glycans in the flowthrough are then purified through graphite-activated carbon column by hydrophilic interaction LC. Yet, the drawback in these affinity-based approaches is nonspecific binding. As a result, chemical methods by hydrazide or oxime have been developed for solid-phase isolation of glycans with high specificity and yield. Combined with high-resolution MS, specific glycan isolation techniques provide tremendous potentials as useful tools for glycomics analysis. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Experimental studies of the seismic response of structures incorporating base-isolation systems

International Nuclear Information System (INIS)

Kelly, J.M.; Aiken, I.D.

1991-01-01

This paper reviews some of the achievements of the Earthquake Engineering Research Center (EERC) at the University of California at Berkeley in the last few years. Component tests on single isolators are described. Tests on plain and high-damping natural-rubber bearings, lead-rubber bearings, sliding bearings, and bearings incorporating uplift resistance mechanisms have been performed. High-shear strain tests on large (up to full scale) elastomeric bearings have been conducted to determine the stability characteristics and limit states of the isolators. Performance evaluation studies using the earthquake simulator to test large-scale model isolated structures have been carried out for a variety of isolation systems and structures. Uplift studies of slender base-isolated buildings and investigation of the behavior of base-isolated skew bridge decks have been studied. This paper aims to highlight those areas where progress has been made. (orig./HP)

Using Euler buckling springs for vibration isolation

CERN Document Server

Winterflood, J; Blair, D G

2002-01-01

Difficulties in obtaining ideal vertical vibration isolation with mechanical springs are identified as being due to the mass of the elastic element which is in turn due to its energy storage requirement. A new technique to minimize this energy is presented - being an Euler column undergoing elastic buckling. The design of a high performance vertical vibration isolation stage based on this technique is presented together with its measured performance.

Using Euler buckling springs for vibration isolation

International Nuclear Information System (INIS)

Winterflood, J; Barber, T; Blair, D G

2002-01-01

Difficulties in obtaining ideal vertical vibration isolation with mechanical springs are identified as being due to the mass of the elastic element which is in turn due to its energy storage requirement. A new technique to minimize this energy is presented - being an Euler column undergoing elastic buckling. The design of a high performance vertical vibration isolation stage based on this technique is presented together with its measured performance

Genotoxicological Evaluation of NUTRALYS Pea Protein Isolate

OpenAIRE

Aouatif, Chentouf; Looten, Ph.; Parvathi, M. V. S.; Raja Ganesh, S.; Paranthaman, V.

2013-01-01

NUTRALYS Pea Protein Isolate, a protein supplement, is a high-quality source of protein which is primarily emulsifying functional protein. We evaluated the genotoxic potential of NUTRALYS isolated from dry yellow pea, using three established genotoxicity tests (AMES test in vitro chromosomal aberration test, and in vivo micronucleus test) employing OECD guidelines under GLP conditions. In the bacterial reverse mutation test, NUTRALYS did not show positive responses in strains detecting point ...

Molecular characterization, fitness and mycotoxin production of benzimidazole-resistant isolates of Penicillium expansum.

Science.gov (United States)

Malandrakis, Anastasios A; Markoglou, Anastasios N; Konstantinou, Sotiris; Doukas, Eleftherios G; Kalampokis, John F; Karaoglanidis, George S

2013-04-01

Penicillium expansum field-strains resistant to benzimidazole fungicides were isolated in high frequency from decayed apple fruit collected from packinghouses and processing industries located in the region of Imathia, N. Greece. In vitro fungitoxicity tests resulted in the identification of two different resistant phenotypes: highly (BEN-HR) and moderately (BEN-MR) carbendazim-resistant. Thirty seven percent of the isolated P. expansum strains belonged to the BEN-HR phenotype, carried no apparent fitness penalties and exhibited resistance levels higher than 60 based on EC50 values. Cross resistance studies with other benzimidazole fungicides showed that all BEN-HR and BEN-MR isolates were also less sensitive to benomyl and thiabendazole. Fungitoxicity tests on the response of BEN-HR isolates to fungicides belonging to other chemical classes revealed no cross-resistance relationships between benzimidazoles and the phenylpyrrole fludioxonil, the dicarboximide iprodione, the anilinopyrimidine cyprodinil, the QoI pyraclostrobin, the imidazole imazalil and the triazole tebuconazole, indicating that a target-site modification is probably responsible for the BEN-HR phenotype observed. Contrary to the above, some BEN-MR isolates exhibited an increased sensitivity to cyprodinil compared to benzimidazole-sensitive ones. BEN-MR isolates had fitness parameters similar to the benzimidazole-sensitive isolates except for conidia production which appeared significantly decreased. Analysis of mycotoxin production (patulin and citrinin) showed that all benzimidazole-resistant isolates produced mycotoxins at concentrations significantly higher than sensitive isolates both on culture medium and on artificially inoculated apple fruit. Comparison of the β-tubulin gene DNA sequence between resistant and sensitive isolates revealed a point mutation resulting from the E198A substitution of the corresponding protein in most but not all HR isolates tested. Molecular analysis of the �

Isolation and biological activity of frankiamide.

Science.gov (United States)

Haansuu, J P; Klika, K D; Söderholm, P P; Ovcharenko, V V; Pihlaja, K; Haahtela, K K; Vuorela, P M

2001-07-01

An antibiotic produced by the symbiotic actinomycete Frankia strain AiPs1 was isolated from culture broth using optimized thin-layer chromatography and high-performance liquid chromatography (HPLC) methods. The novel compound that was isolated, dubbed frankiamide, displayed antimicrobial activity against all 14 Gram-positive bacterial strains and six pathogenic fungal strains tested. The pathogenic actinomycete Clavibacter michiganensis and the oomycete Phytophthora were especially susceptible. In addition to displaying antimicrobial activity, frankiamide also strongly inhibited 45Ca(2+) fluxes in clonal rat pituitary GH4C1 tumor cells and was comparable to a frequently used calcium antagonist, verapamil hydrochloride. The results of HPLC analysis, supported by both nuclear magnetic resonance and mass spectroscopy studies, showed that frankiamide has a high affinity for Na(+) ions.

Comparison of constitutive and thiabendazole-induced expression of five cytochrome P450 genes in fourth-stage larvae of Haemonchus contortus isolates with different drug susceptibility identifies one gene with high constitutive expression in a multi-resistant isolate

Directory of Open Access Journals (Sweden)

Esra Yilmaz

2017-12-01

Full Text Available Benzimidazoles (BZs remain amongst the most widely used anthelmintic drug classes against gastro-intestinal nematode infections, although their efficacy is increasingly compromised by resistance. The primary underlying mechanisms for BZ resistance are single-nucleotide polymorphisms (SNPs in the isotype 1 β-tubulin gene causing the substitutions F167Y, E198A or F200Y. However, resistance is believed to be multi-genic and previous studies have shown that isolates carrying 90–100% F200Y can vary considerably in their resistance level in the egg hatch assay (EHA. Cytochrome P450 monooxygenases (CYPs are associated with drug resistance in mammals and arthropods and have been considered as mediators of anthelmintic resistance. In Caenorhabditis elegans, several members of the CYP34/35 and CYP31 families are BZ and/or xenobiotic inducible and thiabendazole (TBZ is metabolised by CYP35D1. Here, expression of all 5 CYPs closely related to the C. elegans CYP34/35 and CYP31 families was investigated in fourth-stage larvae of two susceptible and three BZ-resistant Haemonchus contortus isolates following in vitro exposure to TBZ for 3 and 6 h using real-time RT-PCR. The resistance status of all isolates was determined using EHAs and quantification of resistance-associated β-tubulin SNPs using pyrosequencing. While none of the CYPs was TBZ inducible, constitutive expression of CYP34/35 family member HCOI100383400 was significantly 2.4–3.7-fold higher in the multi-drug resistant WR isolate with the strongest BZ resistance phenotype compared to susceptible and intermediate-level BZ-resistant isolates. Although this increase is only moderate, HCOI100383400 might still be involved in high-level BZ resistance by further decreasing susceptibility in isolates already carrying 100% of a β-tubulin SNP causing BZ resistance. Lower transcript levels were observed for all CYPs in the intermediately resistant IRE isolate in comparison to the susceptible Hc

Characterisation of a highly pathogenic H5N1 clade 2.3.2 influenza virus isolated from swans in Shanghai, China.

Science.gov (United States)

Zhao, Guo; Zhong, Lei; Lu, Xinlun; Hu, Jiao; Gu, Xiaobing; Kai, Yan; Song, Qingqing; Sun, Qing; Liu, Jinbao; Peng, Daxin; Wang, Xiaoquan; Liu, Xiaowen; Liu, Xiufan

2012-02-01

In spring 2009, one strain of H5N1 clade 2.3.2 virus was isolated from wild swans in Shanghai, indicating the importance of the wild swan in the ecology of this highly pathogenic avian influenza virus (HPAIV) in Eastern China. Pathogenicity experiments conducted in this study indicated that the virus was highly pathogenic for chickens but lowly pathogenic for mammalian hosts, as evidenced by reduced infection of mice. The analysis of complete genome sequences and genetic evolution showed that A/Swan/Shanghai/10/09 (SW/SH/09) may be derived from the strain A/silky chicken/Shantou/475/2004 (CK/ST/04), which is homologous to the influenza viruses isolated from chicken, duck, pika, little egret, swan, mandarin duck and bar-headed goose in China Hunan, China Qinghai, Mongolia, Russia, Japan, Korea, Laos and Hong Kong during 2007-2011, indicating that the virus has retro-infected diverse wild birds from chicken, and significant spread of the virus is still ongoing through overlapping migratory flyways. On the basis of the molecular analysis, we also found that there was a deletion of the glycosylation site (NSS) in amino acid 156 of the hemagglutinin (HA) protein when compared with that of the other Clade 2.3.2 viruses isolated between 2007 and 2011. More importantly, the sequence analysis of SW/SH/09 virus displayed the drug-resistant mutations on the matrix protein (M2) and neuraminidase (NA) genes.

pirABvp-Bearing Vibrio parahaemolyticus and Vibrio campbellii Pathogens Isolated from the Same AHPND-Affected Pond Possess Highly Similar Pathogenic Plasmids

Directory of Open Access Journals (Sweden)

Xuan Dong

2017-10-01

Full Text Available Acute hepatopancreatic necrosis disease (AHPND is a severe shrimp disease originally shown to be caused by virulent strains of Vibrio parahaemolyticus (VPAHPND. Rare cases of AHPND caused by Vibrio species other than V. parahaemolyticus were reported. We compared an AHPND-causing V. campbellii (VCAHPND and a VPAHPND isolate from the same AHPND-affected pond. Both strains are positive for the virulence genes pirABvp. Immersion challenge test with Litopenaeus vannamei indicated the two strains possessed similar pathogenicity. Complete genome comparison showed that the pirABvp-bearing plasmids in the two strains were highly homologous, and they both shared high homologies with plasmid pVA1, the reported pirABvp-bearing plasmid. Conjugation and DNA-uptake genes were found on the pVA1-type plasmids and the host chromosomes, respectively, which may facilitate the dissemination of pirABvp. Novel variations likely driven by ISVal1 in the genetic contexts of the pirABvp genes were found in the two strains. Moreover, the VCAHPND isolate additionally contains multiple antibiotic resistance genes, which may bring difficulties to control its future outbreak. The dissemination of the pirABvp in non-parahaemolyticus Vibrio also rises the concern of missing detection in industrial settings since the isolation method currently used mainly targeting V. parahaemolyticus. This study provides timely information for better understanding of the causes of AHPND and molecular epidemiology of pirABvp and also appeals for precautions to encounter the dissemination of the hazardous genes.

Isolation, Characterization and Identification of Microalgae from the Red Sea

KAUST Repository

Luque Alanís, Patricio

2013-05-01

Eukaryotic microalgae from the Red Sea were isolated, characterized and identified with the purpose of building a culture collection that will serve future research activities in the area of industrial microbiology. Seven sampling locations were surveyed using an in-house designed isolation protocol. Microalgae enrichment was carried out in vitro using the streak plate method and fluorescence activated cell sorting approaches. Colonial and cellular microscopy, growth media preference assays, as well as temperature, pH and salinity tolerance tests were carried out to describe the isolates. DNA extraction, PCR amplification, template sequencing and in silico analyses were carried out to identify the isolates and arrange them in a proper phylogenetic description. In total, 129 isolates were obtained. From these, only 39 were selected for characterization given their increased ability of accumulating large amounts of biomass in solid and liquid media in relatively short periods of time. All of these have a green color, are unicellular, non-motile, photosynthetic organisms and have a cell size ranging from 5 to 8 µm. More than half of them showed growth preference in Walne media, followed by F/2, MN and BG-11 SW. Maximum temperature tolerance of all organisms was around 38 ºC, while optimum growth was observed close to 25 ºC. pH preference was diverse and three groups were identified: acidic (6), intermediate (8 - 9) and alkaline (> 10) growing isolates. Salinity tests showed an overall growth preference at 25 PSU, approximately 10 units lower than that found at the sampling stations. Most isolates showed diminished growth at high salinity and high pH, except for OS3S1b which grew well in both cases, and could be an interesting strain to study further. Twenty four isolates were related to Ulvophyceae sp. MBIC10591 by BLAST approaches with a maximum identity of 96 - 97%. A maximum likelihood phylogenetic tree was created for these isolates, relative to the BLAST hits

Isolation of high-salinity-tolerant bacterial strains, Enterobacter sp., Serratia sp., Yersinia sp., for nitrification and aerobic denitrification under cyanogenic conditions.

Science.gov (United States)

Mpongwana, N; Ntwampe, S K O; Mekuto, L; Akinpelu, E A; Dyantyi, S; Mpentshu, Y

2016-01-01

Cyanides (CN(-)) and soluble salts could potentially inhibit biological processes in wastewater treatment plants (WWTPs), such as nitrification and denitrification. Cyanide in wastewater can alter metabolic functions of microbial populations in WWTPs, thus significantly inhibiting nitrifier and denitrifier metabolic processes, rendering the water treatment processes ineffective. In this study, bacterial isolates that are tolerant to high salinity conditions, which are capable of nitrification and aerobic denitrification under cyanogenic conditions, were isolated from a poultry slaughterhouse effluent. Three of the bacterial isolates were found to be able to oxidise NH(4)-N in the presence of 65.91 mg/L of free cyanide (CN(-)) under saline conditions, i.e. 4.5% (w/v) NaCl. The isolates I, H and G, were identified as Enterobacter sp., Yersinia sp. and Serratia sp., respectively. Results showed that 81% (I), 71% (G) and 75% (H) of 400 mg/L NH(4)-N was biodegraded (nitrification) within 72 h, with the rates of biodegradation being suitably described by first order reactions, with rate constants being: 4.19 h(-1) (I), 4.21 h(-1) (H) and 3.79 h(-1) (G), respectively, with correlation coefficients ranging between 0.82 and 0.89. Chemical oxygen demand (COD) removal rates were 38% (I), 42% (H) and 48% (G), over a period of 168 h with COD reduction being highest at near neutral pH.

The effect of high mesencephalic transection (cerveau isolé) and pentobarbital on basal forebrain mechanisms of EEG synchronization.

Science.gov (United States)

Obál, F; Benedek, G; Szikszay, M; Obál, F

1979-01-01

A study was made of the effects of high mesencephalic transection (cerveau isolé) and low doses of pentobarbital on the cortical synchronizations elicited in acute immobilized cats by (a) low frequency stimulation of the lateral hypothalamus (HL) and nucleus ventralis anterior thalami (VA) and (b) by low and high frequency stimulation of the laterobasal preoptic region (RPO) and olfactory tubercle (TbOf). The results obtained were as follows: (1) The synchronizations induced by basal forebrain stimulations were found to survive in acute cerveau isolé cats, moreover, even a facilitation of the synchronizing effect were observed. (2) A gradual facilitation was observed upon TbOf and RPO stimulation, while in the case of VA and HL stimulations, the facilitation appeared immediately after the transection. (3) Low doses of pentobarbital depressed the cortical effects of TbOf stimulation, while an increase of the synchronizing effect of low frequency VA and HL stimulation was found. The observations suggested that (i) the synchronizing mechanism in the ventral part of the basal forebrain (RPO and TbOf) differs from that of the thalamus and HL; (ii) the basal forebrain synchronizing mechanism is effective without the contribution of the brain stem; (iii) the mechanism responsible for the synchronizing effect of low frequency HL stimulation is similar as that described for the thalamus.

Isolation of the highly pathogenic and zoonotic agent Burkholderia pseudomallei from a pet green Iguana in Prague, Czech Republic.

Science.gov (United States)

Elschner, Mandy C; Hnizdo, Jan; Stamm, Ivonne; El-Adawy, Hosny; Mertens, Katja; Melzer, Falk

2014-11-28

Melioidosis caused by Burkholderia (B.) pseudomallei is an endemic zoonotic disease mainly reported from northern Australia and Southeast Asia. In Europe, cases of human melioidosis have been reported only from patients travelling to endemic regions. Besides humans, B. pseudomallei has a very broad host range in domestic and wild animals. There are some reports about importation of B. pseudomallei-infected animals from endemic areas into Europe. The present report describes the first case of B. pseudomallei infection of a pet iguana in Europe. In a 5-year-old pet Iguana iguana living in a private household in Prague, Czech Republic, B. pseudomallei was isolated from pus of an abscess. The isolate VB976100 was identified by Vitek®2, MALDI-TOF mass spectrometry and polymerase chain reaction as B. pseudomallei. The molecular typing resulted in multi-locus sequence type 436 hitherto, which has been found only once worldwide in a B. pseudomallei strain isolated in the USA and originating from Guatemala. The identification as internal transcribed spacer type G indicates a close relatedness to strains mainly isolated in the Western Hemisphere. These findings support the hypothesis that the iguana became infected in this region or in a breeding facility through contact to other infected animals. The present case highlights the risk of importation of the highly pathogenic and zoonotic B. pseudomallei into non-endemic regions through animal trade. Therefore, veterinarians treating animals from these areas and physicians examining patients owning such animals should include melioidosis in differential diagnosis whenever specific symptoms appear. Furthermore, veterinary authorities responsible for supervision of traders and pet shops should be aware of this risk of zoonotic transmission.

Isolation and Molecular Characterization of Brucella Isolates in Cattle Milk in Uganda

Directory of Open Access Journals (Sweden)

Denis Rwabiita Mugizi

2015-01-01

Full Text Available Brucellosis is endemic in livestock and humans in Uganda and its transmission involves a multitude of risk factors like consumption of milk from infected cattle. To shed new light on the epidemiology of brucellosis in Uganda the present study used phenotypic and molecular approaches to delineate the Brucella species, biovars, and genotypes shed in cattle milk. Brucella abortus without a biovar designation was isolated from eleven out of 207 milk samples from cattle in Uganda. These isolates had a genomic monomorphism at 16 variable number tandem repeat (VNTR loci and showed in turn high levels of genetic variation when compared with other African strains or other B. abortus biovars from other parts of the world. This study further highlights the usefulness of MLVA as an epidemiological tool for investigation of Brucella infections.

Antimicrobial Susceptibility Pattern of Enterococci Isolated From Patients in Tehran

Directory of Open Access Journals (Sweden)

Horieh Saderi

2015-11-01

Full Text Available Background: Enterococci are one of the most common nosocomial pathogens and the emergence of multidrug-resistant strains has been increasing. Objectives: We studied the antimicrobial susceptibility of enterococci isolated from different clinical specimens of patients in Tehran. Materials and Methods: From the beginning of April 2013 to the end of June 2013, a total of 146 enterococci were isolated from the Pars General Hospital in Tehran. The antimicrobial susceptibility pattern of the isolates against ampicillin, clindamaycin, ciprofloxacin, erythromycin, levofloxacin, linezolid, nitrofurantoin, tetracycline, and vancomycin was determined using the disk diffusion method according to the guidelines of clinical laboratory standards institute (CLSI. Results: The rates of resistance were high to clindamycin, tetracycline, and erythromycin (97.2%, 89%, and 74.5%, respectively; moderate to ciprofloxacilin and levofloxacilin (40.6% and 36.4%, respectively; and low to ampicillin and nitrofurantoin (13.8% and 3.5%, respectively. All isolates were linezolid sensitive. Vancomycin-resistant enterococci (VRE accounted for 9.6% of the isolates. Conclusions: VRE and a high rate of resistance to some of antimicrobial agents were found among the enterococci isolated from patients in Tehran. These findings highlight the importance of regular supervision of antimicrobial susceptibilities.

Genotyping of rifampin-resistant Mycobacterium tuberculosis isolates from Western Turkey

International Nuclear Information System (INIS)

Cavasoglu, Cengiz; Bilgic, Altinay; Durmaz, Riza; Gunal, Selami

2004-01-01

Although the rate of multiple drug resistance is high there is no published data on the transmission rate of drug-resistant strains of Mycobacterium tuberculosis in the Aegean region of Western Turkey that are based on molecular methods. IS6110 and pTBN12 restriction fragment lengthpolymorphism (RFLP) methods were used for typing Mycobacterium tuberculosis isolated from 26 sputum samples from 26 patients. 19 of rifampin-resistant isolates (73.1%) contained 6 to 11 copies of 156110. Eighteen different IS6110 DNA fingerprint patterns were observed in the 26 rifampin resistant isolates. 23 of the 26 rifampin-resistant isolates were also resistant to isoniazid. When evaluated together, both methods yielded 21 (80.9%) different banding patterns and the level of clustering was 34.6%. The average number per pattern was 1.23 (26/21). IS6110 fingerprinting suggests that the rifampin-resistant isolates obtained from the Aegean region had a relatively high clustering rate and were clonally related. These findings showed that the rifampin-resistant isolates are actively transmitted between patients. Urgent measures should be taken to prevent the spread of these resistant strains. (author)

High-pressure size exclusion chromatography analysis of dissolved organic matter isolated by tangential-flow ultra filtration

Science.gov (United States)

Everett, C.R.; Chin, Y.-P.; Aiken, G.R.

1999-01-01

A 1,000-Dalton tangential-flow ultrafiltration (TFUF) membrane was used to isolate dissolved organic matter (DOM) from several freshwater environments. The TFUF unit used in this study was able to completely retain a polystyrene sulfonate 1,800-Dalton standard. Unaltered and TFUF-fractionated DOM molecular weights were assayed by high-pressure size exclusion chromatography (HPSEC). The weight-averaged molecular weights of the retentates were larger than those of the raw water samples, whereas the filtrates were all significantly smaller and approximately the same size or smaller than the manufacturer-specified pore size of the membrane. Moreover, at 280 nm the molar absorptivity of the DOM retained by the ultrafilter is significantly larger than the material in the filtrate. This observation suggests that most of the chromophoric components are associated with the higher molecular weight fraction of the DOM pool. Multivalent metals in the aqueous matrix also affected the molecular weights of the DOM molecules. Typically, proton-exchanged DOM retentates were smaller than untreated samples. This TFUF system appears to be an effective means of isolating aquatic DOM by size, but the ultimate size of the retentates may be affected by the presence of metals and by configurational properties unique to the DOM phase.

Whole Genome Sequencing of Enterovirus species C Isolates by High-throughput Sequencing: Development of Generic Primers

Directory of Open Access Journals (Sweden)

Maël Bessaud

2016-08-01

Full Text Available Enteroviruses are among the most common viruses infecting humans and can cause diverse clinical syndromes ranging from minor febrile illness to severe and potentially fatal diseases. Enterovirus species C (EV-C consists of more than 20 types, among which the 3 serotypes of polioviruses, the etiological agents of poliomyelitis, are included. Biodiversity and evolution of EV-C genomes are shaped by frequent recombination events. Therefore, identification and characterization of circulating EV-C strains require the sequencing of different genomic regions.A simple method was developed to sequence quickly the entire genome of EV-C isolates. Four overlapping fragments were produced separately by RT-PCR performed with generic primers. The four amplicons were then pooled and purified prior to be sequenced by high-throughput technique.The method was assessed on a panel of EV-Cs belonging to a wide-range of types. It can be used to determine full-length genome sequences through de novo assembly of thousands of reads. It was also able to discriminate reads from closely related viruses in mixtures.By decreasing the workload compared to classical Sanger-based techniques, this method will serve as a precious tool for sequencing large panels of EV-Cs isolated in cell cultures during environmental surveillance or from patients, including vaccine-derived polioviruses.

Is the High Cu Tolerance of Trichoderma atroviride Isolated from the Cu-Polluted Sediment Due to Adaptation? An In Vitro Toxicological Study

International Nuclear Information System (INIS)

Yap, C.K.; Yazdani, M.; Abdullah, F.; Tan, S.G.

2011-01-01

The tolerance of Cu by Trichoderma atroviride, a tolerant fungus isolated from the drainage surface sediment of the Serdang Industrial Area was investigated under in vitro conditions. Only this fungus species can tolerate up to 600 mg/ L of Cu on solid medium Potato Dextrose Agar based on the isolation of the most tolerant fungus from the polluted sediment. Toxicity test performed on T. atroviride, showed a maximum tolerance at 300 mg/L of Cu concentration when grown in liquid medium Potato Dextrose Broth (PDB). The EC 50 value of the isolate was 287.73 mg/ L of Cu concentration in PDB. The Cu concentration in the drainage surface sediment, where the T. atroviride was isolated from, was 347.64 μg/ g while the geochemical distributions of the non-resistant and resistant fractions of Cu were 99.6 and 0.4 %, respectively. The sediment data indicated that the drainage had greatly received anthropogenic Cu from the nearby industries which are involved in the manufacturing of plastics and electronic products. The present findings indicate that the high Cu tolerance showed by T. atroviride could be due to the well adaptation of the fungus to the Cu polluted sediment. Therefore, T. atroviride could be a potential bioremediator of Cu pollution in the freshwater ecosystem. (author)

Genomic diversity of Escherichia isolates from diverse habitats.

Directory of Open Access Journals (Sweden)

Seungdae Oh

Full Text Available Our understanding of the Escherichia genus is heavily biased toward pathogenic or commensal isolates from human or animal hosts. Recent studies have recovered Escherichia isolates that persist, and even grow, outside these hosts. Although the environmental isolates are typically phylogenetically distinct, they are highly related to and phenotypically indistinguishable from their human counterparts, including for the coliform test. To gain insights into the genomic diversity of Escherichia isolates from diverse habitats, including freshwater, soil, animal, and human sources, we carried out comparative DNA-DNA hybridizations using a multi-genome E. coli DNA microarray. The microarray was validated based on hybridizations with selected strains whose genome sequences were available and used to assess the frequency of microarray false positive and negative signals. Our results showed that human fecal isolates share two sets of genes (n>90 that are rarely found among environmental isolates, including genes presumably important for evading host immune mechanisms (e.g., a multi-drug transporter for acids and antimicrobials and adhering to epithelial cells (e.g., hemolysin E and fimbrial-like adhesin protein. These results imply that environmental isolates are characterized by decreased ability to colonize host cells relative to human isolates. Our study also provides gene markers that can distinguish human isolates from those of warm-blooded animal and environmental origins, and thus can be used to more reliably assess fecal contamination in natural ecosystems.

Virulence Factors and Antibiotic Susceptibility of Staphylococcus aureus Isolates in Ready-to-Eat Foods: Detection of S. aureus Contamination and a High Prevalence of Virulence Genes

Directory of Open Access Journals (Sweden)

Suat Moi Puah

2016-02-01

Full Text Available Staphylococcus aureus is one of the leading causes of food poisoning. Its pathogenicity results from the possession of virulence genes that produce different toxins which result in self-limiting to severe illness often requiring hospitalization. In this study of 200 sushi and sashimi samples, S. aureus contamination was confirmed in 26% of the food samples. The S. aureus isolates were further characterized for virulence genes and antibiotic susceptibility. A high incidence of virulence genes was identified in 96.2% of the isolates and 20 different virulence gene profiles were confirmed. DNA amplification showed that 30.8% (16/52 of the S. aureus carried at least one SE gene which causes staphylococcal food poisoning. The most common enterotoxin gene was seg (11.5% and the egc cluster was detected in 5.8% of the isolates. A combination of hla and hld was the most prevalent coexistence virulence genes and accounted for 59.6% of all isolates. Antibiotic resistance studies showed tetracycline resistance to be the most common at 28.8% while multi-drug resistance was found to be low at 3.8%. In conclusion, the high rate of S. aureus in the sampled sushi and sashimi indicates the need for food safety guidelines.

Microbiological and molecular characterization of Staphylococcus hominis isolates from blood.

Directory of Open Access Journals (Sweden)

Soraya Mendoza-Olazarán

Full Text Available BACKGROUND: Among Coagulase-Negative Staphylococci (CoNS, Staphylococcus hominis represents the third most common organism recoverable from the blood of immunocompromised patients. The aim of this study was to characterize biofilm formation, antibiotic resistance, define the SCCmec (Staphylococcal Chromosomal Cassette mec type, and genetic relatedness of clinical S. hominis isolates. METHODOLOGY: S. hominis blood isolates (n = 21 were screened for biofilm formation using crystal violet staining. Methicillin resistance was evaluated using the cefoxitin disk test and the mecA gene was detected by PCR. Antibiotic resistance was determined by the broth microdilution method. Genetic relatedness was determined by pulsed-field gel electrophoresis (PFGE and SCCmec typed by multiplex PCR using two different methodologies described for Staphylococcus aureus. RESULTS: Of the S. hominis isolates screened, 47.6% (10/21 were categorized as strong biofilm producers and 23.8% (5/21 as weak producers. Furthermore, 81% (17/21 of the isolates were methicillin resistant and mecA gene carriers. Resistance to ampicillin, erythromycin, and trimethoprim was observed in >70% of isolates screened. Each isolate showed a different PFGE macrorestriction pattern with similarity ranging between 0-95%. Among mecA-positive isolates, 14 (82% harbored a non-typeable SCCmec type: eight isolates were not positive for any ccr complex; four contained the mec complex A ccrAB1 and ccrC, one isolate contained mec complex A, ccrAB4 and ccrC, and one isolate contained the mec complex A, ccrAB1, ccrAB4, and ccrC. Two isolates harbored the association: mec complex A and ccrAB1. Only one strain was typeable as SCCmec III. CONCLUSIONS: The S. hominis isolates analyzed were variable biofilm producers had a high prevalence of methicillin resistance and resistance to other antibiotics, and high genetic diversity. The results of this study strongly suggested that S. hominis isolates harbor

Sagnac interferometry with coherent vortex superposition states in exciton-polariton condensates

Science.gov (United States)

Moxley, Frederick Ira; Dowling, Jonathan P.; Dai, Weizhong; Byrnes, Tim

2016-05-01

We investigate prospects of using counter-rotating vortex superposition states in nonequilibrium exciton-polariton Bose-Einstein condensates for the purposes of Sagnac interferometry. We first investigate the stability of vortex-antivortex superposition states, and show that they survive at steady state in a variety of configurations. Counter-rotating vortex superpositions are of potential interest to gyroscope and seismometer applications for detecting rotations. Methods of improving the sensitivity are investigated by targeting high momentum states via metastable condensation, and the application of periodic lattices. The sensitivity of the polariton gyroscope is compared to its optical and atomic counterparts. Due to the large interferometer areas in optical systems and small de Broglie wavelengths for atomic BECs, the sensitivity per detected photon is found to be considerably less for the polariton gyroscope than with competing methods. However, polariton gyroscopes have an advantage over atomic BECs in a high signal-to-noise ratio, and have other practical advantages such as room-temperature operation, area independence, and robust design. We estimate that the final sensitivities including signal-to-noise aspects are competitive with existing methods.

Biological Traits of Botrytis cinerea Pers. Isolates Differently Sensitive to Dicarboximides

Directory of Open Access Journals (Sweden)

Brankica Tanović

2007-01-01

Full Text Available A study of biological characteristics of both field and laboratory isolates revealed that highly resistant isolates were morphologically different from their original wild types. The majority of them were less pathogenic and produced less sclerotia than the original ones.Significant negative correlation between osmotic sensitivity and the degree of resistance was recorded. The correlation between micelium growth rate and resistance to dicarboximides was also significant and negative. Growth medium, acidity and growth temperature had less effect on the micelium growth rate of the highly resistant isolates than on the sensitive ones.

Chromobacterium sphagni sp. nov., an insecticidal bacterium isolated from Sphagnum bogs.

Science.gov (United States)

Blackburn, Michael B; Farrar, Robert R; Sparks, Michael E; Kuhar, Daniel; Mitchell, Ashaki; Gundersen-Rindal, Dawn E

2017-09-01

Sixteen isolates of Gram-reaction-negative, motile, violet-pigmented bacteria were isolated from Sphagnum bogs in West Virginia and Maine, USA. 16S rRNA gene sequences and fatty acid analysis revealed a high degree of relatedness among the isolates, and genome sequencing of two isolates, IIBBL 14B-1T and IIBBL 37-2 (from West Virginia and Maine, respectively), revealed highly similar genomic sequences. The average nucleotide identity (gANI) calculated for these two isolates was found to be in excess of 99 %, but did not exceed 88 % when comparing either isolate with genomic sequences of Chromobacterium violaceum ATCC 12472T, C. haemolyticum DSM 19808T, C. piscinae ND17, C. subtsugae PRAA4-1T, C. vaccinii MWU205T or C. amazonense CBMAI 310T. Collectively, gANI and 16S rRNA gene sequence comparisons suggested that isolates IIBBL 14B-1T and IIBBL 37-2 were most closely related to C. subtsugae, but represented a distinct species. We propose the name Chromobacterium sphagni sp. nov. for this taxon; the type strain is IIBBL 14B-1T (=NRRL B-67130T=JCM 31882T).

Experimental Study of Vibration Isolation Characteristics of a Geometric Anti-Spring Isolator

Directory of Open Access Journals (Sweden)

Lixun Yan

2017-07-01

Full Text Available In order to realize low-frequency vibration isolation, a novel geometric anti-spring isolator consisting of several cantilever blade springs are developed in this paper. The optimal design parameters of the geometric anti-spring isolator for different nonlinear geometric parameters are theoretically obtained. The transmissibility characteristic of the geometric anti-spring isolator is investigated through mathematical simulation. A geometric anti-spring isolator with a nonlinear geometric parameter of 0.92 is designed and its vibration isolation performance and nonlinearity characteristic is experimentally studied. The experiment results show that the designed isolator has good low-frequency vibration isolation performance, of which the initial isolation frequency is less than 3.6 Hz when the load weight is 21 kg. The jump phenomena of the response of the isolator under linear frequency sweep excitation are observed, and this result demonstrates that the geometric anti-spring isolator has a complex nonlinearity characteristics with the increment of excitation amplitude. This research work provides a theoretical and experimental basis for the application of the nonlinear geometric anti-spring low-frequency passive vibration isolation technology in engineering practice.

Molecular characterization of partial fusion gene and C-terminus extension length of haemagglutinin-neuraminidase gene of recently isolated Newcastle disease virus isolates in Malaysia

Directory of Open Access Journals (Sweden)

Berhanu Ayalew

2010-08-01

Full Text Available Abstract Background Newcastle disease (ND, caused by Newcastle disease virus (NDV, is a highly contagious disease of birds and has been one of the major causes of economic losses in the poultry industry. Despite routine vaccination programs, sporadic cases have occasionally occurred in the country and remain a constant threat to commercial poultry. Hence, the present study was aimed to characterize NDV isolates obtained from clinical cases in various locations of Malaysia between 2004 and 2007 based on sequence and phylogenetic analysis of partial F gene and C-terminus extension length of HN gene. Results The coding region of eleven NDV isolates fusion (F gene and carboxyl terminal region of haemagglutinin-neuraminidase (HN gene including extensions were amplified by reverse transcriptase PCR and directly sequenced. All the isolates have shown to have non-synonymous to synonymous base substitution rate ranging between 0.081 - 0.264 demonstrating presence of negative selection. Analysis based on F gene showed the characterized isolates possess three different types of protease cleavage site motifs; namely 112RRQKRF117, 112RRRKRF117 and 112GRQGRL117 and appear to show maximum identities with isolates in the region such as cockatoo/14698/90 (Indonesia, Ch/2000 (China, local isolate AF2240 indicating the high similarity of isolates circulating in the South East Asian countries. Meanwhile, one of the isolates resembles commonly used lentogenic vaccine strains. On further characterization of the HN gene, Malaysian isolates had C-terminus extensions of 0, 6 and 11 amino acids. Analysis of the phylogenetic tree revealed that the existence of three genetic groups; namely, genotype II, VII and VIII. Conclusions The study concluded that the occurrence of three types of NDV genotypes and presence of varied carboxyl terminus extension lengths among Malaysian isolates incriminated for sporadic cases.

Molecular characterization of partial fusion gene and C-terminus extension length of haemagglutinin-neuraminidase gene of recently isolated Newcastle disease virus isolates in Malaysia.

Science.gov (United States)

Berhanu, Ayalew; Ideris, Aini; Omar, Abdul R; Bejo, Mohd Hair

2010-08-08

Newcastle disease (ND), caused by Newcastle disease virus (NDV), is a highly contagious disease of birds and has been one of the major causes of economic losses in the poultry industry. Despite routine vaccination programs, sporadic cases have occasionally occurred in the country and remain a constant threat to commercial poultry. Hence, the present study was aimed to characterize NDV isolates obtained from clinical cases in various locations of Malaysia between 2004 and 2007 based on sequence and phylogenetic analysis of partial F gene and C-terminus extension length of HN gene. The coding region of eleven NDV isolates fusion (F) gene and carboxyl terminal region of haemagglutinin-neuraminidase (HN) gene including extensions were amplified by reverse transcriptase PCR and directly sequenced. All the isolates have shown to have non-synonymous to synonymous base substitution rate ranging between 0.081 - 0.264 demonstrating presence of negative selection. Analysis based on F gene showed the characterized isolates possess three different types of protease cleavage site motifs; namely 112RRQKRF117, 112RRRKRF117 and 112GRQGRL117 and appear to show maximum identities with isolates in the region such as cockatoo/14698/90 (Indonesia), Ch/2000 (China), local isolate AF2240 indicating the high similarity of isolates circulating in the South East Asian countries. Meanwhile, one of the isolates resembles commonly used lentogenic vaccine strains. On further characterization of the HN gene, Malaysian isolates had C-terminus extensions of 0, 6 and 11 amino acids. Analysis of the phylogenetic tree revealed that the existence of three genetic groups; namely, genotype II, VII and VIII. The study concluded that the occurrence of three types of NDV genotypes and presence of varied carboxyl terminus extension lengths among Malaysian isolates incriminated for sporadic cases.

Performance and scalability of isolated DC-DC converter topologies in low voltage, high current applications

Energy Technology Data Exchange (ETDEWEB)

Vaisanen, V.

2012-07-01

Fuel cells are a promising alternative for clean and efficient energy production. A fuel cell is probably the most demanding of all distributed generation power sources. It resembles a solar cell in many ways, but sets strict limits to current ripple, common mode voltages and load variations. The typically low output voltage from the fuel cell stack needs to be boosted to a higher voltage level for grid interfacing. Due to the high electrical efficiency of the fuel cell, there is a need for high efficiency power converters, and in the case of low voltage, high current and galvanic isolation, the implementation of such converters is not a trivial task. This thesis presents galvanically isolated DC-DC converter topologies that have favorable characteristics for fuel cell usage and reviews the topologies from the viewpoint of electrical efficiency and cost efficiency. The focus is on evaluating the design issues when considering a single converter module having large current stresses. The dominating loss mechanism in low voltage, high current applications is conduction losses. In the case of MOSFETs, the conduction losses can be efficiently reduced by paralleling, but in the case of diodes, the effectiveness of paralleling depends strongly on the semiconductor material, diode parameters and output configuration. The transformer winding losses can be a major source of losses if the windings are not optimized according to the topology and the operating conditions. Transformer prototyping can be expensive and time consuming, and thus it is preferable to utilize various calculation methods during the design process in order to evaluate the performance of the transformer. This thesis reviews calculation methods for solid wire, litz wire and copper foil winding losses, and in order to evaluate the applicability of the methods, the calculations are compared against measurements and FEM simulations. By selecting a proper calculation method for each winding type, the winding

Search for Wh Production Using High-P_T Isolated Like-Sign Dilepton Events in 1.96-TeV Proton-Antiproton Collisions

Energy Technology Data Exchange (ETDEWEB)

Wakisaka, Takayuki [Osaka City Univ. (Japan)

2009-04-01

The thesis describes search for the neutral Higgs production associated with the W boson using high-P_T isolated like-sign (LS) dilepton events in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV.

Are Isolated Indigenous Populations Headed toward Extinction?

Directory of Open Access Journals (Sweden)

Robert S Walker

Full Text Available At least 50 indigenous groups spread across lowland South America remain isolated and have only intermittent and mostly hostile interactions with the outside world. Except in emergency situations, the current policy of governments in Brazil, Colombia, and Peru towards isolated tribes is a "leave them alone" strategy, in which isolated groups are left uncontacted. However, these no-contact policies are based on the assumption that isolated populations are healthy and capable of persisting in the face of mounting external threats, and that they can maintain population viability in the long-term. Here, we test this assumption by tracking the sizes and movements of cleared horticultural areas made by 8 isolated groups over the last 10-14 years. We used deforestation data derived from remote sensing Landsat satellite sensors to identify clearings, and those were then validated and assessed with high-resolution imagery. We found only a single example of a relatively large and growing population (c. 50 cleared ha and 400 people, whereas all of the other 7 groups exhibited much smaller villages and gardens with no sizable growth through time. These results indicated that the smaller groups are critically endangered, and it prompts an urgent re-thinking of policies toward isolated populations, including plans for well-organized contacts that may help save lives and rescue isolated indigenous populations from imminent extinction.

Are Isolated Indigenous Populations Headed toward Extinction?

Science.gov (United States)

Walker, Robert S; Kesler, Dylan C; Hill, Kim R

2016-01-01

At least 50 indigenous groups spread across lowland South America remain isolated and have only intermittent and mostly hostile interactions with the outside world. Except in emergency situations, the current policy of governments in Brazil, Colombia, and Peru towards isolated tribes is a "leave them alone" strategy, in which isolated groups are left uncontacted. However, these no-contact policies are based on the assumption that isolated populations are healthy and capable of persisting in the face of mounting external threats, and that they can maintain population viability in the long-term. Here, we test this assumption by tracking the sizes and movements of cleared horticultural areas made by 8 isolated groups over the last 10-14 years. We used deforestation data derived from remote sensing Landsat satellite sensors to identify clearings, and those were then validated and assessed with high-resolution imagery. We found only a single example of a relatively large and growing population (c. 50 cleared ha and 400 people), whereas all of the other 7 groups exhibited much smaller villages and gardens with no sizable growth through time. These results indicated that the smaller groups are critically endangered, and it prompts an urgent re-thinking of policies toward isolated populations, including plans for well-organized contacts that may help save lives and rescue isolated indigenous populations from imminent extinction.

Metabolic versatility of Gram-positive microbial isolates from contaminated river sediments

International Nuclear Information System (INIS)

Narancic, Tanja; Djokic, Lidija; Kenny, Shane T.; O’Connor, Kevin E.; Radulovic, Vanja; Nikodinovic-Runic, Jasmina; Vasiljevic, Branka

2012-01-01

Highlights: ► Thirty-four isolated Gram-positive bacteria could degrade wide range of aromatic pollutants. ► Nine isolates could grow in the presence of extremely high levels of heavy metals. ► Twelve isolates accumulated polyphosphate, 3 polyhydroxybutyrate, 4 exopolysaccharides. ► The incidence of multiple antibiotic resistance markers among isolates was low. - Abstract: Gram-positive bacteria from river sediments affected by the proximity of a petrochemical industrial site were isolated and characterized with respect to their ability to degrade a wide range of aromatic compounds. In this study we identified metabolically diverse Gram-positive bacteria capable of growth on wide range aromatic compounds in the presence of heavy metals and with the ability to accumulate biopolymers. Thirty-four isolates that were able to use 9 or more common aromatic pollutants, such as benzene, biphenyl, naphthalene etc. as a sole source of carbon and energy included members of Bacillus, Arthrobacter, Rhodococcus, Gordonia, Streptomyces, and Staphylococcus genus. Rhodococcus sp. TN105, Gordonia sp. TN103 and Arthrobacter sp. TN221 were identified as novel strains. Nine isolates were able to grow in the presence of one or more metals (mercury, cadmium, nickel) at high concentration (100 mM). Seven isolates could degrade 15 different aromatic compounds and could grow in the presence of one or more heavy metals. Two of these isolates were resistant to multiple antibiotics including erythromycin and nalidixic acid. One third of isolates could accumulate at least one biopolymer. Twelve isolates (mainly Bacillus sp. and Arthrobacter sp.) accumulated polyphosphate, 3 Bacillus sp. accumulated polyhydroxybutyrate, while 4 isolates could accumulate exopolysaccharides.

Molecular cloning of cellulase genes from indigenous bacterial isolates

International Nuclear Information System (INIS)

Jong Bor Chyan; Pauline Liew Woan Ying; Mat Rasol Awang

2006-01-01

Indigenous cellulolytic bacterial isolates having high activities in degrading carboxymethyl cellulose (CMC) were isolated from local environments. Identification of these isolates were performed by molecular techniques. By using polymerase chain reaction (PCR) techniques, PCR products encoding cellulase gene were amplified from the total genomic DNAs. Purified PCR product was successfully cloned and expressed in Escherichia coli host system. The complete nucleotide sequences of the cellulase genes determined. The analysis of amino acid sequences deduced from the genes indicated that the cloned DNA fragments show high homology to those of endoglucanase genes of family GH5. All cloned genes consist of an N-terminal signal peptide, a catalytic domain of family 5 glycosyl hydrolase and a cellulose-binding domain of family III. (Author)

Isolation and screening of strains producing high amounts of rutin degrading enzymes from Fagopyrum tataricum seeds.

Science.gov (United States)

Zheng, Ya-Di; Luo, Qing-Lin; Zhou, Mei-Liang; Wang, De-Zhou; Zhang, Ye-Dong; Shao, Ji-Rong; Zhu, Xue-Mei; Tang, Yu

2013-02-01

The rutin degrading enzyme (RDE) was isolated and purified from tartary buckwheat seeds. The RDE was purified about 11.34-fold and its final yield was 3.5%, which was very low, due to our purification strategy of giving priority to purity over yield. The RDE molecular weight was estimated to be about 60 kDa. When rutin was used as substrate, an optimal enzyme activity was seen at around pH 5.0 and 40 °C. Strains isolation strategy characterized by the use of rutin as sole carbon source in enrichment cultures was used to isolate RDE-producing strains. Then the active strains were identified by morphology characterization and 18s rDNA-ITS (Internal Transcribed Spacer) gene sequencing. Three isolates coded as B3, W2, Y2 were successfully isolated from fusty Fagopyrum tataricum flour cultures. Strain B3 possessed the highest unit activity among these three strains, and its total activity reached up to 171.0 Unit. The active isolate (B3) could be assigned to Penicillium farinosum. When the Penicillium farinosum strains were added to tartary buckwheat flour cultures at pH 5.0, 30 °C after 5 days fermentation, the quercetin production raised up to 1.78 mg/l, almost 5.1 times higher than the fermentation without the above active strains. Hence, a new approach was available to utilize microorganism-aided fermentation for effective quercetin extraction from Fagopyrum tataricum seeds. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isolated DC-DC Converter for Bidirectional Power Flow Controlling with Soft-Switching Feature and High Step-Up/Down Voltage Conversion

Directory of Open Access Journals (Sweden)

Chih-Lung Shen

2017-03-01

Full Text Available In this paper, a novel isolated bidirectional DC-DC converter is proposed, which is able to accomplish high step-up/down voltage conversion. Therefore, it is suitable for hybrid electric vehicle, fuel cell vehicle, energy backup system, and grid-system applications. The proposed converter incorporates a coupled inductor to behave forward-and-flyback energy conversion for high voltage ratio and provide galvanic isolation. The energy stored in the leakage inductor of the coupled inductor can be recycled without the use of additional snubber mechanism or clamped circuit. No matter in step-up or step-down mode, all power switches can operate with soft switching. Moreover, there is a inherit feature that metal–oxide–semiconductor field-effect transistors (MOSFETs with smaller on-state resistance can be adopted because of lower voltage endurance at primary side. Operation principle, voltage ratio derivation, and inductor design are thoroughly described in this paper. In addition, a 1-kW prototype is implemented to validate the feasibility and correctness of the converter. Experimental results indicate that the peak efficiencies in step-up and step-down modes can be up to 95.4% and 93.6%, respectively.

Seismic Isolation Studies and Applications for Nuclear Facilities

International Nuclear Information System (INIS)

Choun, Young Sun

2005-01-01

Seismic isolation, which is being used worldwide for buildings, is a well-known technology to protect structures from destructive earthquakes. In spite of the many potential advantages of a seismic isolation, however, the applications of a seismic isolation to nuclear facilities have been very limited because of a lack of sufficient knowledge about the isolation practices. The most important advantage of seismic isolation applications in nuclear power plants is that the safety and reliability of the plants can be remarkably improved through the standardization of the structures and equipment regardless of the seismic conditions of the sites. The standardization of structures and equipment will reduce the capital cost and design/construction schedule for future plants. Also, a seismic isolation can facilitate decoupling of the design and development for equipment, piping, and components due to the use of the generic in-structure response spectra associated with the standardized plant. Moreover, a seismic isolation will improve the plant safety margin against the design basis earthquake (DBE) as well as a beyond design basis seismic event due to its superior seismic performance. A number of seismic isolation systems have been developed and tested since 1970s, and some of them have been applied to conventional structures in several countries of high seismicity. In the nuclear field, there have been many studies on the applicability of such seismic isolation systems, but the application of a seismic isolation is very limited. Currently, there are some discussions on the application of seismic isolation systems to nuclear facilities between the nuclear industries and the regulatory agencies in the U.S.. In the future, a seismic isolation for nuclear facilities will be one of the important issues in the nuclear industry. This paper summarizes the past studies and applications of a seismic isolation in the nuclear industry

Multi-Wavelength Polarimetry of Isolated Neutron Stars

Directory of Open Access Journals (Sweden)

Roberto P. Mignani

2018-03-01

Full Text Available Isolated neutron stars are known to be endowed with extreme magnetic fields, whose maximum intensity ranges from 10 12 – 10 15 G, which permeates their magnetospheres. Their surrounding environment is also strongly magnetized, especially in the compact nebulae powered by the relativistic wind from young neutron stars. The radiation from isolated neutron stars and their surrounding nebulae is, thus, supposed to bring a strong polarization signature. Measuring the neutron star polarization brings important information about the properties of their magnetosphere and of their highly magnetized environment. Being the most numerous class of isolated neutron stars, polarization measurements have been traditionally carried out for radio pulsars, hence in the radio band. In this review, I summarize multi-wavelength linear polarization measurements obtained at wavelengths other than radio both for pulsars and other types of isolated neutron stars and outline future perspectives with the upcoming observing facilities.

A Single Switch Dual Output Non-Isolated Boost Converter

DEFF Research Database (Denmark)

Klimczak, Pawel; Munk-Nielsen, Stig

2008-01-01

There are many applications for high gain dc-dc converters. In several of these applications galvanic isolation is not required, but there are some safety issues regarding missing isolation and leakage current. Usage of a half-bridge inverter and a dual dc-link may solve this issues. In this paper...

[Isolation and characterization of vaginal lactobacilli producing hydrogen peroxide].

Science.gov (United States)

Pashaian, M M; Oganesian, G G

2011-01-01

Isolation and characteristics of vaginal lactobacilli that actively generate H2O2 and have high antagonistic activity. Staphylococcus aureus 8956, Escherichia coli 8852, Klebsiella pneumoniae 8795 and Candida albicans 5646 were used as target-strains. Skim milk and MRS medium were used for lactobacilli isolation and cultivation. Antagonism was studied in complete agar and Saburo medium. Merckoquant peroxide test (Merck) stripes were used for the determination of H2O2. Antibacterial activity was determined by diffusion into agar. Specific culture growth rate was determined by conventional method, acidification of the culture medium--by pH-meter. 12 strains were isolated from vaginal smears of healthy women. These strains have an ability to ferment milk among which a highly active H2O2 producer was isolated and attributed to Lactobacillus delbrueckii by the results of 16S rRNA and alpha-subunit RNA polymerase gene sequence analysis (16S rDNA and rpoA genes are registered in GenBank, numbers HQ379171 and HQ379180 respectively). L. delbrueckii MH-10 bacterial cells were characterized by specific growth speed 1.26 per hour, reaching a maximum titer of 2 x 10(9) PFU/ml with lowering medium pH to 4.0. Under aerated conditions H2O2 concentration reached 100 microg/ml or more. L. delbrueckii MH-10 has high antibacterial activity against S. aureus, E. coli, K. pneumoniae. L. delbrueckii MH-10 isolate is an active H2O2 producer, has high growth speed and broad antibacterial activity spectrum, is a perspective candidate for the development of probiotic preparation for the prophylaxis and therapy of vaginoses.

Target materials for exotic ISOL beams

CERN Document Server

Gottberg, A

2016-01-01

The demand for intensity, purity, reliability and availability of short-lived isotopes far from stability is steadily high, and considerably exceeding the supply. In many cases the ISOL (Isotope Separation On-Line) method can provide beams of high intensity and purity. Limitations in terms of accessible chemical species and minimum half-life are driven mainly by chemical reactions and physical processes inside of the thick target. A wide range of materials are in use, ranging from thin metallic foils and liquids to refractory ceramics, while poly-phasic mixed uranium carbides have become the reference target material for most ISOL facilities world-wide. Target material research and development is often complex and especially important post-irradiation analyses are hindered by the high intrinsic radiotoxicity of these materials. However, recent achievements have proven that these investigations are possible if the effort of different facilities is combined, leading to the development of new material matrices t...

Complete genome sequences of three tomato spotted wilt virus isolates from tomato and pepper plants in Korea and their phylogenetic relationship to other TSWV isolates.

Science.gov (United States)

Lee, Jong-Seung; Cho, Won Kyong; Kim, Mi-Kyeong; Kwak, Hae-Ryun; Choi, Hong-Soo; Kim, Kook-Hyung

2011-04-01

Tomato spotted wilt virus (TSWV) infects numerous host plants and has three genome segments, called L, M and S. Here, we report the complete genome sequences of three Korean TSWV isolates (TSWV-1 to -3) infecting tomato and pepper plants. Although the nucleotide sequence of TSWV-1 genome isolated from tomato is very different from those of TSWV-2 and TSWV-3 isolated from pepper, the deduced amino acid sequences of the five TSWV genes are highly conserved among all three TSWV isolates. In phylogenetic analysis, deduced RdRp protein sequences of TSWV-2 and TSWV-3 were clustered together with two previously reported isolates from Japan and Korea, while TSWV-1 grouped together with a Hawaiian isolate. A phylogenetic tree based on N protein sequences, however, revealed four distinct groups of TSWV isolates, and all three Korean isolates belonged to group II, together with many other isolates, mostly from Europe and Asia. Interestingly, most American isolates grouped together as group I. Together, these results suggested that these newly identified TSWV isolates might have originated from an Asian ancestor and undergone divergence upon infecting different host plants.

Characterization of Clade 2.3.2.1 H5N1 Highly Pathogenic Avian Influenza Viruses Isolated from Wild Birds (Mandarin Duck and Eurasian Eagle Owl in 2010 in Korea

Directory of Open Access Journals (Sweden)

Youn-Jeong Lee

2013-04-01

Full Text Available Starting in late November 2010, the H5N1 highly pathogenic avian influenza (HPAI virus was isolated from many types of wild ducks and raptors and was subsequently isolated from poultry in Korea. We assessed the genetic and pathogenic properties of the HPAI viruses isolated from a fecal sample from a mandarin duck and a dead Eurasian eagle owl, the most affected wild bird species during the 2010/2011 HPAI outbreak in Korea. These viruses have similar genetic backgrounds and exhibited the highest genetic similarity with recent Eurasian clade 2.3.2.1 HPAI viruses. In animal inoculation experiments, regardless of their originating hosts, the two Korean isolates produced highly pathogenic characteristics in chickens, ducks and mice without pre-adaptation. These results raise concerns about veterinary and public health. Surveillance of wild birds could provide a good early warning signal for possible HPAI infection in poultry as well as in humans.

Xerophilic mycopopulations isolated from rapeseeds (Brassica napus

Directory of Open Access Journals (Sweden)

Škrinjar Marija M.

2013-01-01

Full Text Available This paper presents the results of an investigation related to mycological populations of rapeseed samples produced in the Institute of Field and Vegetable Crops in Novi Sad (location: Rimski Šančevi, Novi Sad, with a special emphasis on the potentially toxigenic mycopopulations. Mycological investigations were performed on the samples that were treated with 4% solution of Na-hypochlorite, and on the ones that were not submitted to this treatment. Isolation and determination of total mould count was carried out using Dichloran Glycerol Agar (DG18. The identification of isolated moulds was done according to modern keys for fungal determination. From 20 untreated tested samples, 17 were contaminated with moulds (10.0 to 4.7x102 cfu/g. When the samples were treated with 4% solution of Na-hypochlorite, moulds were isolated only form 4 samples, and the total mould count ranged from 10.0 to 60.0 cfu/g. In the isolated mycopopulations, xerophilic moulds dominated, especially those from the genera Aspergillus, Eurotium and Penicillium. In the isolated mycopopulations, high degree of isolated species belonged to toxigenic species from the genera Alternaria, Aspergillus, Fusarium, Eurotium and Penicillium. [Projekat Ministarstva nauke Republike Srbije, br. III46009 i br.TR31025

High efficiency isolated DC/DC converter inherently optimized for fuel cell applications

DEFF Research Database (Denmark)

Petersen, Lars Press; Jensen, Lasse Crone; Larsen, Martin Norgaard

2013-01-01

The isolated full-bridge boost converter has been suggested as the best choice for fuel cell applications. Comparisons have been carried out in the literature using both stress factors and experimental verified designs to determine the optimal converter. Never the less, this paper suggests...

Isolated/Non-Isolated Quad-Inverter Configuration for Multilevel Symmetrical/Asymmetrical Dual Six-Phase Star-Winding Converter

DEFF Research Database (Denmark)

Padmanaban, Sanjeevi Kumar; Hontz, Michael R.; Khanna, Raghav

2016-01-01

This article presents the developments of a novel isolated/non-isolated quad inverter configuration for multilevel dual six-phase (twelve-phase) star-winding converter. The modular circuit consists of four standard voltage source inverters (VSIs). Each VSI is incorporated with one bi-directional ...... systems, electrical vehicles, AC tractions, and `More-Electric Aircraft' propulsion systems....... converter is numerically modeled using Matlab/PLECS simulation software and the predicted behavior of the system is analyzed and presented. Good agreement is obtained between these results and the theoretical analysis. Suitable applications for the converter include (low-voltage/high-current) medium power...

THE AGORA HIGH-RESOLUTION GALAXY SIMULATIONS COMPARISON PROJECT. II. ISOLATED DISK TEST

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji-hoon [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Agertz, Oscar [Department of Physics, University of Surrey, Guildford, Surrey, GU2 7XH (United Kingdom); Teyssier, Romain; Feldmann, Robert [Centre for Theoretical Astrophysics and Cosmology, Institute for Computational Science, University of Zurich, Zurich, 8057 (Switzerland); Butler, Michael J. [Max-Planck-Institut für Astronomie, D-69117 Heidelberg (Germany); Ceverino, Daniel [Zentrum für Astronomie der Universität Heidelberg, Institut für Theoretische Astrophysik, D-69120 Heidelberg (Germany); Choi, Jun-Hwan [Department of Astronomy, University of Texas, Austin, TX 78712 (United States); Keller, Ben W. [Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1 (Canada); Lupi, Alessandro [Institut d’Astrophysique de Paris, Sorbonne Universites, UPMC Univ Paris 6 et CNRS, F-75014 Paris (France); Quinn, Thomas; Wallace, Spencer [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Revaz, Yves [Institute of Physics, Laboratoire d’Astrophysique, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Gnedin, Nickolay Y. [Particle Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States); Leitner, Samuel N. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Shen, Sijing [Kavli Institute for Cosmology, University of Cambridge, Cambridge, CB3 0HA (United Kingdom); Smith, Britton D., E-mail: me@jihoonkim.org [Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ (United Kingdom); Collaboration: AGORA Collaboration; and others

2016-12-20

Using an isolated Milky Way-mass galaxy simulation, we compare results from nine state-of-the-art gravito-hydrodynamics codes widely used in the numerical community. We utilize the infrastructure we have built for the AGORA High-resolution Galaxy Simulations Comparison Project. This includes the common disk initial conditions, common physics models (e.g., radiative cooling and UV background by the standardized package Grackle) and common analysis toolkit yt, all of which are publicly available. Subgrid physics models such as Jeans pressure floor, star formation, supernova feedback energy, and metal production are carefully constrained across code platforms. With numerical accuracy that resolves the disk scale height, we find that the codes overall agree well with one another in many dimensions including: gas and stellar surface densities, rotation curves, velocity dispersions, density and temperature distribution functions, disk vertical heights, stellar clumps, star formation rates, and Kennicutt–Schmidt relations. Quantities such as velocity dispersions are very robust (agreement within a few tens of percent at all radii) while measures like newly formed stellar clump mass functions show more significant variation (difference by up to a factor of ∼3). Systematic differences exist, for example, between mesh-based and particle-based codes in the low-density region, and between more diffusive and less diffusive schemes in the high-density tail of the density distribution. Yet intrinsic code differences are generally small compared to the variations in numerical implementations of the common subgrid physics such as supernova feedback. Our experiment reassures that, if adequately designed in accordance with our proposed common parameters, results of a modern high-resolution galaxy formation simulation are more sensitive to input physics than to intrinsic differences in numerical schemes.

The heterogeneity of socially isolated older adults: a social isolation typology.

Science.gov (United States)

Machielse, Anja

2015-01-01

Recent statistics show a growing number of older adults who are living alone and are socially isolated. It is against this background that, in recent years, many interventions have been developed to address social isolation among the elderly. Evaluative studies show that most interventions are hardly effective, though. An important reason for this is the heterogeneity of the socially isolated. This article offers insight into this heterogeneity by presenting a typology with different profiles of socially isolated older adults and the intervention implications of this typology. The typology is derived from an extensive qualitative study on socially isolated elderly individuals in the Netherlands. The typology imposes some degree of order to a diversity of circumstances, ambitions, and possibilities of the socially isolated elderly, thereby deepening the understanding of the heterogeneity of this population. The definition of social isolation used in this study starts from a societal angle of incidence, namely the current policy context of Western European welfare states, in which governments emphasize the importance of independence and self-reliance of their citizens. Developed from that perspective, the typology provides a theoretical basis for applying interventions aimed at increasing self-reliance of social isolated elderly. This perspective on social isolation also has consequences for the way in which the effectiveness of interventions to alleviate social isolation is assessed.

The isolation and partial characterization of a highly pathogenic herpesvirus from the harbor seal (Phoca vitulina).

NARCIS (Netherlands)

A.D.M.E. Osterhaus (Albert); H. Yang (Hong); H.E.M. Spijkers (Ine); J. Groen (Jan); J.S. Teppema; G. van Steenis (Bert)

1985-01-01

textabstractThis report describes the first isolation and partial characterization of a herpesvirus from the harbor seal (Phoca vitulina). The virus was isolated during a disease outbreak in a group of young seals nursed in a seal orphanage in The Netherlands. Almost half of the seals died with

Linear drag law for high-Reynolds-number flow past an oscillating body

Science.gov (United States)

Agre, Natalie; Childress, Stephen; Zhang, Jun; Ristroph, Leif

2016-07-01

An object immersed in a fast flow typically experiences fluid forces that increase with the square of speed. Here we explore how this high-Reynolds-number force-speed relationship is affected by unsteady motions of a body. Experiments on disks that are driven to oscillate while progressing through air reveal two distinct regimes: a conventional quadratic relationship for slow oscillations and an anomalous scaling for fast flapping in which the time-averaged drag increases linearly with flow speed. In the linear regime, flow visualization shows that a pair of counterrotating vortices is shed with each oscillation and a model that views a train of such dipoles as a momentum jet reproduces the linearity. We also show that appropriate scaling variables collapse the experimental data from both regimes and for different oscillatory motions into a single drag-speed relationship. These results could provide insight into the aerodynamic resistance incurred by oscillating wings in flight and they suggest that vibrations can be an effective means to actively control the drag on an object.

Conjunctival sac bacterial flora isolated prior to cataract surgery

Directory of Open Access Journals (Sweden)

Suto C

2012-01-01

a history of allergic conjunctivitis. Methicillin-resistant coagulase-negative staphylococci showed a significantly higher detection rate in diabetic patients than nondiabetic patients (20.3% versus 7.0%, P < 0.05. The percentage of all isolates resistant to levofloxacin, cefmenoxime, and tobramycin was 14.0%, 15.2%, and 17.9%, respectively, with no significant differences among these drugs.Conclusion: The high bacterial isolation rate in patients >60 years old and the high methicillin-resistant coagulase-negative staphylococci isolation rate in patients with diabetes are important to consider for prevention of perioperative infections.Keywords: endophthalmitis, cataract surgery, conjunctival sac, bacterial flora, diabetes mellitus

Isolation, Characterization, and Functional Role of the High-Potential Iron-Sulfur Protein (HiPIP) from Rhodoferax fermentans

DEFF Research Database (Denmark)

Hochkoeppler, A.; Kofod, P.; Ferro, G.

1995-01-01

A new high-potential iron-sulfur protein (HiPIP) has been isolated and purified to homogeneity from the soluble fraction obtained from light-grown cells of the facultative photoheterotrophic bacterium Rhodoferax fermentans. The new protein was identified as a HiPIP by virtue of its molecular...... other sources and, in particular, the iron content is consistent with the presence of one [Fe4S4] cubane cluster per molecule. The isoelectric pH values of the two redox forms are consistent with a basic protein. Kinetic studies of HiPIP oxidation, performed by monitoring the absorbance changes induced...

Low pulmonary artery flush perfusion pressure combined with high positive end-expiratory pressure reduces oedema formation in isolated porcine lungs

International Nuclear Information System (INIS)

Schumann, Stefan; Schließmann, Stephan J; Wagner, Giskard; Goebel, Ulrich; Priebe, Hans-Joachim; Guttmann, Josef; Kirschbaum, Andreas

2010-01-01

Flush perfusion of the pulmonary artery with organ protection solution is a standard procedure before lung explantation. However, rapid flush perfusion may cause pulmonary oedema which is deleterious in the lung transplantation setting. In this study we tested the hypotheses that high pulmonary perfusion pressure contributes to the development of pulmonary oedema and positive end-expiratory pressure (PEEP) counteracts oedema formation. We expected oedema formation to increase weight and decrease compliance of the lungs on the basis of a decrease in alveolar volume as fluid replaces alveolar air spaces. The pulmonary artery of 28 isolated porcine lungs was perfused with a low-potassium dextrane solution at low (mean 27 mmHg) or high (mean 40 mmHg) pulmonary artery pressure (PAP) during mechanical ventilation at low (4 cmH 2 O) or high (8 cmH 2 O) PEEP, respectively. Following perfusion and storage, relative increases in lung weight were smaller (p < 0.05) during perfusion at low PAP (62 ± 32% and 42 ± 26%, respectively) compared to perfusion at high PAP (133 ± 54% and 87 ± 30%, respectively). Compared to all other PAP–PEEP combinations, increases in lung weight were smallest (44 ± 9% and 27 ± 12%, respectively), nonlinear intratidal lung compliance was largest (46% and 17% respectively, both p < 0.05) and lung histology showed least infiltration of mononuclear cells in the alveolar septa, and least alveolar destruction during the combination of low perfusion pressure and high PEEP. The findings suggest that oedema formation during pulmonary artery flush perfusion in isolated and ventilated lungs can be reduced by choosing low perfusion pressure and high PEEP. PAP–PEEP titration to minimize pulmonary oedema should be based on lung mechanics and PAP monitoring

High prevalence of non-clonal imipenem-nonsusceptible Enterobacter spp. isolates in Korea and their association with porin down-regulation.

Science.gov (United States)

Lee, Ji-Young; Hong, Yoon-Kyoung; Lee, Haejeong; Ko, Kwan Soo

2017-01-01

We investigated the prevalence and clonal distribution of imipenem-nonsusceptible Enterobacter clinical isolates from hospitals in Korea and the contributions of various mechanisms to imipenem nonsusceptibility. The in vitro antimicrobial susceptibility to imipenem of 357 non-duplicated Enterobacter isolates obtained from eight geographically distant tertiary care hospitals in Korea was evaluated. Imipenem-nonsusceptible Enterobacter isolates were genotyped. Additionally, β-lactamase genes were screened using PCR, and the expression of efflux pump and porin genes was investigated using quantitative RT-PCR. A total of 31 isolates (8.7%) were not susceptible to imipenem. Clonal diversity of 17 imipenem-nonsusceptible E. cloacae isolates was demonstrated by multilocus sequence typing. Fourteen imipenem-nonsusceptible E. aerogenes isolates were found to be distantly genetically related by an ERIC-PCR analysis. Expression levels of porin ompD and ompK35 genes were decreased in all imipenem-nonsusceptible E. cloacae and E. aerogenes isolates. However, only two isolates were found positive for bla IMP and bla VIM genes, and expression of the efflux pump gene, acrB, was not associated with reduced imipenem susceptibility. Imipenem resistance seems to have occurred independently in most of the imipenem-nonsusceptible isolates in this study, and decreased porin expression was found to be the main mechanism underlying this reduced susceptibility to imipenem. Copyright © 2016 Elsevier Inc. All rights reserved.

Application of Shape Memory Alloys in Seismic Isolation: A Review

Directory of Open Access Journals (Sweden)