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Sample records for attenuation ncq models

  1. Nonlinear viscoelastic wave propagation: an extension of Nearly Constant Attenuation (NCQ) models

    CERN Document Server

    Delépine, Nicolas; Bonnet, Guy; Semblat, Jean-François

    2009-01-01

    Hysteretic damping is often modeled by means of linear viscoelastic approaches such as ?nearly constant Attenuation (NCQ)? models. These models do not take into account nonlinear effects either on the stiffness or on the damping, which are well known features of soil dynamic behavior. The aim of this paper is to propose a mechanical model involving nonlinear viscoelastic behavior for isotropic materials. This model simultaneously takes into account nonlinear elasticity and nonlinear damping. On the one hand, the shear modulus is a function of the excitation level; on the other, the description of viscosity is based on a generalized Maxwell body involving non-linearity. This formulation is implemented into a 1D finite element approach for a dry soil. The validation of the model shows its ability to retrieve low amplitude ground motion response. For larger excitation levels, the analysis of seismic wave propagation in a nonlinear soil layer over an elastic bedrock leads to results which are physically satisfact...

  2. Preparation and preliminary biological evaluation of [[sup 18]F]NCQ-115: a new selective reversible dopamine D2 receptor ligand

    Energy Technology Data Exchange (ETDEWEB)

    Najafi, A.; Peterson, A.; Buchsbaum, M. (California Univ., Irvine, CA (United States). Dept. of Psychiatry); O' Dell, S.; Weihmuller, F. (California Univ., Irvine , CA (United States). Dept. of Psychobiology)

    1993-05-01

    [sup 18]F-labeled dopamine D2 antagonist, NCQ-115 ((+)-(R)-5-bromo-N-((fluorobenzyl)-2-pyrrolidinyl)-methyl-2,3-dime thoxybenzamide), was successfully prepared using a remotely controlled system. [[sup 18]F]Fluoride was reacted with the trifluoromethanesulfonate salt of 4-(trimethylamino)benzaldehyde. The product was first reduced with LAH, and then reacted with thionyl bromide to yield [sup 18]F-labeled 4-fluorobenzylbromide. [[sup 18]F]4-fluorobenzylbromide was then reacted with the pyrrolidine precursor (NCQ-282) to yield the product [[sup 18]F]NCQ-115 contaminated with unreacted starting material. The product was purified by reverse phase chromatography yielding [[sup 18]F]NCQ-115 with a specific activity of more than 1400 Ci/mmol. Autoradiographic and biodistribution data following injection of [[sup 18]F]NCQ-115 in rats revealed the regional uptake of striatum/cerebellum to be 3.2 at 30 min post-injection. (author).

  3. Precision Model for Microwave Rotary Vane Attenuator

    DEFF Research Database (Denmark)

    Guldbrandsen, Tom

    1979-01-01

    A model for a rotary vane attenuator is developed to describe the attenuator reflection and transmission coefficients in detail. All the parameters of the model can be measured in situ, i.e., without diassembling any part. The tranmission errors caused by internal reflections are calculated from ...

  4. Autoradiographic comparison of [125I]epidepride and [125I]NCQ 298 binding to human brain extrastriated dopamine receptors.

    Science.gov (United States)

    Hall, H; Halldin, C; Jerning, E; Osterlund, M; Farde, L; Sedvall, G

    1997-07-01

    Extrastriatal D2-dopamine receptors can be visualised in the monkey and human brain using the benzamides [11C]- and [76Br]FLB 457 in PET and [123I]epidepride in SPECT but not with the salicylamide analogues [76Br]FLB 463 and [123I]NCQ 298. To clarify the background for the differences in binding seen in vivo, we have compared the in vitro binding of [125I]epidepride and [123I]NCQ 298, using human whole hemisphere autoradiography. The images obtained with any radioligand showed detailed distribution with very dense binding in the putamen and the caudate nucleus and with the same detailed extrastriatal distribution. Thus, the divergent results obtained in vivo cannot be explained by different binding properties of the extrastriatal receptors. PMID:9290072

  5. Autoradiographic comparison of [125I]epidepride and [125I]NCQ 298 binding to human brain extrastriated dopamine receptors

    International Nuclear Information System (INIS)

    Extrastriatal D2-dopamine receptors can be visualized in the monkey and human brain using the benzamides [11C]- and [76Br]FLB 457 in PET and [123I]epidepride in SPECT but not with the salicylamide analogues [76Br]FLB 463 and [123I]NCQ 298. To clarify the background for the differences in binding seen in vivo, we have compared the in vitro binding of [125I]epidepride and [125I]NCQ 298, using human whole hemisphere autoradiography. The images obtained with any radioligand showed detailed distribution with very dense binding in the putamen and the caudate nucleus and with the same detailed extrastriatal distribution. Thus, the divergent results obtained in vivo cannot be explained by different binding properties of the extrastriatal receptors

  6. Towards a Global Upper Mantle Attenuation Model

    Science.gov (United States)

    Karaoglu, Haydar; Romanowicz, Barbara

    2015-04-01

    Global anelastic tomography is crucial for addressing the nature of heterogeneity in the Earth's interior. The intrinsic attenuation manifests itself through dispersion and amplitude decay. These are contaminated by elastic effects such as (de)focusing and scattering. Therefore, mapping anelasticity accurately requires separation of elastic effects from the anelastic ones. To achieve this, a possible approach is to try and first predict elastic effects through the computation of seismic waveforms in a high resolution 3D elastic model, which can now be achieved accurately using numerical wavefield computations. Building upon the recent construction of such a whole mantle elastic and radially anisotropic shear velocity model (SEMUCB_WM1, French and Romanowicz, 2014), which will be used as starting model, our goal is to develop a higher resolution 3D attenuation model of the upper mantle based on full waveform inversion. As in the development of SEMUCB_WM1, forward modeling will be performed using the spectral element method, while the inverse problem will be treated approximately, using normal mode asymptotics. Both fundamental and overtone time domain long period waveforms (T>60s) will be used from a dataset of over 200 events observed at several hundred stations globally. Here we present preliminary results of synthetic tests, exploring different iterative inversion strategies.

  7. Autoradiographic comparison of [{sup 125}I]epidepride and [{sup 125}I]NCQ 298 binding to human brain extrastriated dopamine receptors

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Haakan; Halldin, Christer; Jerning, Eva; Oesterlund, Marie; Farde, Lars; Sedvall, Goeran

    1997-07-01

    Extrastriatal D{sub 2}-dopamine receptors can be visualized in the monkey and human brain using the benzamides [{sup 11}C]- and [{sup 76}Br]FLB 457 in PET and [{sup 123}I]epidepride in SPECT but not with the salicylamide analogues [{sup 76}Br]FLB 463 and [{sup 123}I]NCQ 298. To clarify the background for the differences in binding seen in vivo, we have compared the in vitro binding of [{sup 125}I]epidepride and [{sup 125}I]NCQ 298, using human whole hemisphere autoradiography. The images obtained with any radioligand showed detailed distribution with very dense binding in the putamen and the caudate nucleus and with the same detailed extrastriatal distribution. Thus, the divergent results obtained in vivo cannot be explained by different binding properties of the extrastriatal receptors.

  8. WAVE ATTENUATION OVER MUD BED: A PSEUDO-PLASTIC MODEL

    Institute of Scientific and Technical Information of China (English)

    Zhang Qing-he; Onyx W.H. Wai; Joseph H. W. Lee

    2003-01-01

    A two-layer model, with the upper layer being the perfect fluid and the lower layer being the pseudo-plastic fluid describing water wave attenuation over mud bed, was established. A simplified method based on the principle of equivalent work was applied to solve the boundary value problems. The computational results of the model show that the two-layer perfect fluid model and the perfect-viscous fluid model are all special cases of the present model. The complex nonlinear properties of wave attenuation over mud bed, can be explained by the present model, e.g., the wave dissipation rate decreases with the wave height in certain cases, while the small wave propagates over mud bed with less energy dissipation and large wave attenuates rapidly in other cases. Other factors influencing the wave attenuation were also discussed.

  9. Broadband Lg Attenuation Modeling in the Middle East

    Energy Technology Data Exchange (ETDEWEB)

    Pasyanos, M E; Matzel, E M; Walter, W R; Rodgers, A J

    2008-08-21

    We present a broadband tomographic model of Lg attenuation in the Middle East derived from source- and site-corrected amplitudes. Absolute amplitude measurements are made on hand-selected and carefully windowed seismograms for tens of stations and thousands of crustal earthquakes resulting in excellent coverage of the region. A conjugate gradient method is used to tomographically invert the amplitude dataset of over 8000 paths over a 45{sup o} x 40{sup o} region of the Middle East. We solve for Q variation, as well as site and source terms, for a wide range of frequencies ranging from 0.5-10 Hz. We have modified the standard attenuation tomography technique to more explicitly define the earthquake source expression in terms of the seismic moment. This facilitates the use of the model to predict the expected amplitudes of new events, an important consideration for earthquake hazard or explosion monitoring applications. The attenuation results have a strong correlation to tectonics. Shields have low attenuation, while tectonic regions have high attenuation, with the highest attenuation at 1 Hz is found in eastern Turkey. The results also compare favorably to other studies in the region made using Lg propagation efficiency, Lg/Pg amplitude ratios and two-station methods. We tomographically invert the amplitude measurements for each frequency independently. In doing so, it appears the frequency-dependence of attenuation is not compatible with the power law representation of Q(f), an assumption that is often made.

  10. Model-based design of growth-attenuated viruses.

    Directory of Open Access Journals (Sweden)

    Kwang-Il Lim

    2006-09-01

    Full Text Available Live-virus vaccines activate both humoral and cell-mediated immunity, require only a single boosting, and generally provide longer immune protection than killed or subunit vaccines. However, growth of live-virus vaccines must be attenuated to minimize their potential pathogenic effects, and mechanisms of attenuation by conventional serial-transfer viral adaptation are not well-understood. New methods of attenuation based on rational engineering of viral genomes may offer a potentially greater control if one can link defined genetic modifications to changes in virus growth. To begin to establish such links between genotype and growth phenotype, we developed a computer model for the intracellular growth of vesicular stomatitis virus (VSV, a well-studied, nonsegmented, negative-stranded RNA virus. Our model incorporated established regulatory mechanisms of VSV while integrating key wild-type infection steps: hijacking of host resources, transcription, translation, and replication, followed by assembly and release of progeny VSV particles. Generalization of the wild-type model to allow for genome rearrangements matched the experimentally observed attenuation ranking for recombinant VSV strains that altered the genome position of their nucleocapsid gene. Finally, our simulations captured previously reported experimental results showing how altering the positions of other VSV genes has the potential to attenuate the VSV growth while overexpressing the immunogenic VSV surface glycoprotein. Such models will facilitate the engineering of new live-virus vaccines by linking genomic manipulations to controlled changes in virus gene-expression and growth.

  11. Outdoor FSO Communications Under Fog: Attenuation Modeling and Performance Evaluation

    KAUST Repository

    Esmail, Maged Abdullah

    2016-07-18

    Fog is considered to be a primary challenge for free space optics (FSO) systems. It may cause attenuation that is up to hundreds of decibels per kilometer. Hence, accurate modeling of fog attenuation will help telecommunication operators to engineer and appropriately manage their networks. In this paper, we examine fog measurement data coming from several locations in Europe and the United States and derive a unified channel attenuation model. Compared with existing attenuation models, our proposed model achieves a minimum of 9 dB, which is lower than the average root-mean-square error (RMSE). Moreover, we have investigated the statistical behavior of the channel and developed a probabilistic model under stochastic fog conditions. Furthermore, we studied the performance of the FSO system addressing various performance metrics, including signal-to-noise ratio (SNR), bit-error rate (BER), and channel capacity. Our results show that in communication environments with frequent fog, FSO is typically a short-range data transmission technology. Therefore, FSO will have its preferred market segment in future wireless fifth-generation/sixth-generation (5G/6G) networks having cell sizes that are lower than a 1-km diameter. Moreover, the results of our modeling and analysis can be applied in determining the switching/thresholding conditions in highly reliable hybrid FSO/radio-frequency (RF) networks.

  12. Modeling of aqueous foam blast wave attenuation

    Science.gov (United States)

    Del Prete, E.; Chinnayya, A.; Hadjadj, A.; Domergue, L.; Haas, J.-F.; Imbert, B.

    The use of aqueous foams enables the mitigation of blast waves induced by the explosion of energetic materials. The two-phase confinement gives rise to interphase interactions between the gaseous and liquid phases, which role have been emphasized in shock-tube studies with solid foams [1, 2]. Multifluid formalism enables the thermo-mechanical disequilibria between phases to be taken into account. The flow model ensures the correct estimation of the acoustic impedance of the two-phase media. As for the numerical scheme, Riemann solvers are used to describe the microscopic fluid interactions, the summation of which provides the multiphase flux. The role of the different transfer mechanisms is evaluated in the case where the liquid ligaments of the foam matrix have been shattered into droplets by the shock impingement. Characteristics of blast waves in heterogeneous media leads to a decrease of overpressure. The numerical results have been compared favorably to experimental data [3, 4].

  13. Modeling transmission and scatter for photon beam attenuators.

    Science.gov (United States)

    Ahnesjö, A; Weber, L; Nilsson, P

    1995-11-01

    The development of treatment planning methods in radiation therapy requires dose calculation methods that are both accurate and general enough to provide a dose per unit monitor setting for a broad variety of fields and beam modifiers. The purpose of this work was to develop models for calculation of scatter and transmission for photon beam attenuators such as compensating filters, wedges, and block trays. The attenuation of the beam is calculated using a spectrum of the beam, and a correction factor based on attenuation measurements. Small angle coherent scatter and electron binding effects on scattering cross sections are considered by use of a correction factor. Quality changes in beam penetrability and energy fluence to dose conversion are modeled by use of the calculated primary beam spectrum after passage through the attenuator. The beam spectra are derived by the depth dose effective method, i.e., by minimizing the difference between measured and calculated depth dose distributions, where the calculated distributions are derived by superposing data from a database for monoenergetic photons. The attenuator scatter is integrated over the area viewed from the calculation point of view using first scatter theory. Calculations are simplified by replacing the energy and angular-dependent cross-section formulas with the forward scatter constant r2(0) and a set of parametrized correction functions. The set of corrections include functions for the Compton energy loss, scatter attenuation, and secondary bremsstrahlung production. The effect of charged particle contamination is bypassed by avoiding use of dmax for absolute dose calibrations. The results of the model are compared with scatter measurements in air for copper and lead filters and with dose to a water phantom for lead filters for 4 and 18 MV. For attenuated beams, downstream of the buildup region, the calculated results agree with measurements on the 1.5% level. The accuracy was slightly less in situations

  14. Modeling transmission and scatter for photon beam attenuators.

    Science.gov (United States)

    Ahnesjö, A; Weber, L; Nilsson, P

    1995-11-01

    The development of treatment planning methods in radiation therapy requires dose calculation methods that are both accurate and general enough to provide a dose per unit monitor setting for a broad variety of fields and beam modifiers. The purpose of this work was to develop models for calculation of scatter and transmission for photon beam attenuators such as compensating filters, wedges, and block trays. The attenuation of the beam is calculated using a spectrum of the beam, and a correction factor based on attenuation measurements. Small angle coherent scatter and electron binding effects on scattering cross sections are considered by use of a correction factor. Quality changes in beam penetrability and energy fluence to dose conversion are modeled by use of the calculated primary beam spectrum after passage through the attenuator. The beam spectra are derived by the depth dose effective method, i.e., by minimizing the difference between measured and calculated depth dose distributions, where the calculated distributions are derived by superposing data from a database for monoenergetic photons. The attenuator scatter is integrated over the area viewed from the calculation point of view using first scatter theory. Calculations are simplified by replacing the energy and angular-dependent cross-section formulas with the forward scatter constant r2(0) and a set of parametrized correction functions. The set of corrections include functions for the Compton energy loss, scatter attenuation, and secondary bremsstrahlung production. The effect of charged particle contamination is bypassed by avoiding use of dmax for absolute dose calibrations. The results of the model are compared with scatter measurements in air for copper and lead filters and with dose to a water phantom for lead filters for 4 and 18 MV. For attenuated beams, downstream of the buildup region, the calculated results agree with measurements on the 1.5% level. The accuracy was slightly less in situations

  15. Modeling of aqueous foam blast wave attenuation

    Directory of Open Access Journals (Sweden)

    Domergue L.

    2011-01-01

    Full Text Available The use of aqueous foams enables the mitigation of blast waves induced by the explosion of energetic materials. The two-phase confinement gives rise to interphase interactions between the gaseous and liquid phases, which role have been emphasized in shock-tube studies with solid foams [1, 2]. Multifluid formalism enables the thermo-mechanical disequilibria between phases to be taken into account. The flow model ensures the correct estimation of the acoustic impedance of the two-phase media. As for the numerical scheme, Riemann solvers are used to describe the microscopic fluid interactions, the summation of which provides the multiphase flux. The role of the different transfer mechanisms is evaluated in the case where the liquid ligaments of the foam matrix have been shattered into droplets by the shock impingement. Characteristics of blast waves in heterogeneous media leads to a decrease of overpressure. The numerical results have been compared favorably to experimental data [3, 4].

  16. Attenuating wind turbine loads through model based individual pitch control

    DEFF Research Database (Denmark)

    Thomsen, Sven Creutz; Niemann, Hans Henrik; Poulsen, Niels Kjølstad

    2009-01-01

    In this paper we consider wind turbine load attenuation through model based control. Asymmetric loads caused by the wind field can be reduced by pitching the blades individually. To this end we investigate the use of stochastic models of the wind which can be included in a model based individual...... pitch controller design. In this way the variability of the wind can be estimated and compensated for by the controller. The wind turbine model is in general time-variant due to its rotational nature. For this reason the modeling and control is carried out in so-called multiblade coordinates...

  17. Wave attenuation model for dephasing and measurement of conditional times

    Indian Academy of Sciences (India)

    A M Jayannavar; Colin Benjamin

    2002-08-01

    Inelastic scattering induces dephasing in mesoscopic systems. An analysis of previous models to simulate inelastic scattering in such systems is presented and a relatively new model based on wave attenuation is introduced. The problem of Aharonov–Bohm (AB) oscillations in conductance of a mesoscopic ring is studied. We show that the conductance is symmetric under flux reversal and the visibility of AB oscillations decays to zero as a function of the incoherence parameter, signaling dephasing. Further the wave attenuation model is applied to a fundamental problem in quantum mechanics, that of the conditional (reflection/transmission) times spent in a given region of space by a quantum particle before scattering off from that region.

  18. Forward- vs. Inverse Problems in Modeling Seismic Attenuation

    Science.gov (United States)

    Morozov, I. B.

    2015-12-01

    Seismic attenuation is an important property of wave propagation used in numerous applications. However, the attenuation is also a complex phenomenon, and it is important to differentiate between its two typical uses: 1) in forward problems, to model the amplitudes and spectral contents of waves required for hazard assessment and geotechnical engineering, and 2) in inverse problems, to determine the physical properties of the subsurface. In the forward-problem sense, the attenuation is successfully characterized in terms of empirical parameters of geometric spreading, radiation patterns, scattering amplitudes, t-star, alpha, kappa, or Q. Arguably, the predicted energy losses can be correct even if the underlying attenuation model is phenomenological and not sufficiently based on physics. An example of such phenomenological model is the viscoelasticity based on the correspondence principle and the Q-factor assigned to the material. By contrast, when used to invert for in situ material properties, models addressing the specific physics are required. In many studies (including in this session), a Q-factor is interpreted as a property of a point within the subsurface; however this property is only phenomenological and may be physically insufficient or inconsistent. For example, the bulk or shear Q at the same point can be different when evaluated from different wave modes. The cases of frequency-dependent Q are particularly prone of ambiguities such as trade-off with the assumed background geometric spreading. To rigorously characterize the in situ material properties responsible for seismic-wave attenuation, it is insufficient to only focus on the seismic energy loss. Mechanical models of the material need to be considered. Such models can be constructed by using Lagrangian mechanics. These models should likely contain no Q but will be based on parameters of microstructure such as heterogeneity, fractures, or fluids. I illustrate several such models based on viscosity

  19. Study of number of constituent quark scaling of elliptic flow in heavy-ion collisions using transport model

    CERN Document Server

    Singha, Subhash

    2016-01-01

    We studied the number of constituent quark scaling (NCQ) behaviour of elliptic flow ($v_{2}$) under the framework of A Multi-Phase Transport model (AMPT) at both top-RHIC and LHC energies. The NCQ-scaling in $v_{2}$ holds at top-RHIC energy with AMPT string melting version, while it breaks in Pb+Pb collisions at LHC energy using the same framework. The breaking of NCQ-scaling at LHC energy has been studied by varying the magnitude of parton-parton scattering cross-section and lifetime of hadronic cascade as implemented in AMPT. We find that the breaking of NCQ scaling in Pb+Pb collisions at $\\sqrt{s_{NN}}$ =2.76 TeV is independent of the magnitude of parton-parton cross-section and the later stage hadronic interactions. Further we observed that scaling holds in a small collision system like Si+Si at $\\sqrt{s_{NN}}$ = 2.76 TeV. We discussed that the breaking of NCQ scaling is possibly due to high phase-space density of constituents quarks in Pb+Pb collisions at $\\sqrt{s_{NN}}$ = 2.76 TeV.

  20. A two-component rain model for the prediction of attenuation statistics

    Science.gov (United States)

    Crane, R. K.

    1982-01-01

    A two-component rain model has been developed for calculating attenuation statistics. In contrast to most other attenuation prediction models, the two-component model calculates the occurrence probability for volume cells or debris attenuation events. The model performed significantly better than the International Radio Consultative Committee model when used for predictions on earth-satellite paths. It is expected that the model will have applications in modeling the joint statistics required for space diversity system design, the statistics of interference due to rain scatter at attenuating frequencies, and the duration statistics for attenuation events.

  1. Modeling classic attenuation regulation of gene expression in bacteria.

    Science.gov (United States)

    Lyubetsky, Vassily A; Pirogov, Sergey A; Rubanov, Lev I; Seliverstov, Alexander V

    2007-02-01

    A model is proposed primarily for the classical RNA attenuation regulation of gene expression through premature transcription termination. The model is based on the concept of the RNA secondary structure macrostate within the regulatory region between the ribosome and RNA-polymerase, on hypothetical equation describing deceleration of RNA-polymerase by a macrostate and on views of transcription and translation initiation and elongation, under different values of the four basic model parameters which were varied. A special effort was made to select adequate model parameters. We first discuss kinetics of RNA folding and define the concept of the macrostate as a specific parentheses structure used to construct a conventional set of hairpins. The originally developed software that realizes the proposed model offers functionality to fully model RNA secondary folding kinetics. Its performance is compared to that of a public server described in Ref. 1. We then describe the delay in RNA-polymerase shifting to the next base or its premature termination caused by an RNA secondary structure or, herefrom, a macrostate. In this description, essential concepts are the basic and excited states of the polymerase first introduced in Ref. 2: the polymerase shifting to the next base can occur only in the basic state, and its detachment from DNA strand - only in excited state. As to the authors' knowledge, such a model incorporating the above-mentioned attenuation characteristics is not published elsewhere. The model was implemented in an application with command line interface for running in batch mode in Windows and Linux environments, as well as a public web server.(3) The model was tested with a conventional Monte Carlo procedure. In these simulations, the estimate of correlation between the premature transcription termination probability p and concentration c of charged amino acyl-tRNA was obtained as function p(c) for many regulatory regions in many bacterial genomes, as well as

  2. Northern California Seismic Attenuation: 3-D Qp and Qs models

    Science.gov (United States)

    Eberhart-Phillips, D. M.

    2015-12-01

    The northern California crust exhibits a wide range of rock types and deformation processes which produce pronounced heterogeneity in regional attenuation. Using local earthquakes, 3-D Qp and Qs crustal models have been obtained for this region which includes the San Andreas fault system, the Central Valley, the Sierra Nevada batholith, and the Mendocino subduction volcanic system. Path attenuation t* values were determined from P and S spectra of 959 spatially distributed earthquakes, magnitude 2.5-6.0 from 2005-2014, using 1254 stations from NCEDC networks and IRIS Mendocino and Sierra Nevada temporary arrays. The t* data were used in Q inversions, using existing hypocenters and 3-D velocity models, with basic 10-km node spacing. The uneven data coverage was accounted for with linking of nodes into larger areas in order to provide useful Q images across the 3-D volume. The results at shallow depth (< 2 km) show very low Q in the Sacramento Delta, the Eureka area, and parts of the Bay Area. In the brittle crust, fault zones that have high seismicity exhibit low Q. In the lower crust, low Q is observed along fault zones that have large cumulative displacement and have experienced grain size reduction. Underlying active volcanic areas, low Q features are apparent below 20-km depth. Moderately high Q is associated with igneous rocks of the Sierra Nevada and Salinian block, while the Franciscan subduction complex shows moderately low Q. The most prominent high Q feature is related to the Great Valley Ophiolite.

  3. Modeling of polychromatic attenuation using computed tomography reconstructed images

    Science.gov (United States)

    Yan, C. H.; Whalen, R. T.; Beaupre, G. S.; Yen, S. Y.; Napel, S.

    1999-01-01

    This paper presents a procedure for estimating an accurate model of the CT imaging process including spectral effects. As raw projection data are typically unavailable to the end-user, we adopt a post-processing approach that utilizes the reconstructed images themselves. This approach includes errors from x-ray scatter and the nonidealities of the built-in soft tissue correction into the beam characteristics, which is crucial to beam hardening correction algorithms that are designed to be applied directly to CT reconstructed images. We formulate this approach as a quadratic programming problem and propose two different methods, dimension reduction and regularization, to overcome ill conditioning in the model. For the regularization method we use a statistical procedure, Cross Validation, to select the regularization parameter. We have constructed step-wedge phantoms to estimate the effective beam spectrum of a GE CT-I scanner. Using the derived spectrum, we computed the attenuation ratios for the wedge phantoms and found that the worst case modeling error is less than 3% of the corresponding attenuation ratio. We have also built two test (hybrid) phantoms to evaluate the effective spectrum. Based on these test phantoms, we have shown that the effective beam spectrum provides an accurate model for the CT imaging process. Last, we used a simple beam hardening correction experiment to demonstrate the effectiveness of the estimated beam profile for removing beam hardening artifacts. We hope that this estimation procedure will encourage more independent research on beam hardening corrections and will lead to the development of application-specific beam hardening correction algorithms.

  4. FSO and radio link attenuation: meteorological models verified by experiment

    Science.gov (United States)

    Brazda, Vladimir; Fiser, Ondrej; Svoboda, Jaroslav

    2011-09-01

    Institute of Atmospheric Physics of Czech Academy measures atmospheric attenuation on 60 m experimental FSO link on 830 and 1550 nm for more than three years. Visibility sensors and two 3D sonic anemometers on both transmitting and receiving site, rain gauge and many sensors enabling the refractivity index computation are spaced along the optical link. Meteorological visibility, wind turbulent energy, sonic temperature, structure index and rain rate are correlated with measured attenuation. FSO link attenuation dependence on the above mentioned parameters is analyzed. The paper shows also basic statistical behavior of the long-term FSO signal level and also the simulation of hybrid link techniques.

  5. An experimental model of ice floe induced attenuation of ocean waves

    CERN Document Server

    Toffoli, Alessandro; Bennetts, Luke G; Meylan, Michael H; Cavaliere, Claudio; Babanin, Alexandr

    2014-01-01

    An experimental model of ocean wave attenuation due to interactions with an ice floe is presented. Evolution of mechanically-generated, regular waves is monitored in front and in the lee of a solitary, square floe, made of a synthetic material. Results confirm dependence of attenuation on the period of the incident wave. Results also indicate dependence of attenuation on the depth of wave overwash on the floe.

  6. Grim19 Attenuates DSS Induced Colitis in an Animal Model.

    Science.gov (United States)

    Kim, Jae-Kyung; Lee, Seung Hoon; Lee, Seon-Young; Kim, Eun-Kyung; Kwon, Jeong-Eun; Seo, Hyeon-Beom; Lee, Han Hee; Lee, Bo-In; Park, Sung-Hwan; Cho, Mi-La

    2016-01-01

    DSS induced colitis is a chronic inflammatory disease characterized by inflammation in the gastrointestinal tract, which destabilizes the gut and induces an uncontrolled immune response. Although DSS induced colitis is generally thought to develop as a result of an abnormally active intestinal immune system, its pathogenesis remains unclear. Gene associated with retinoid interferon induced mortality (Grim) 19 is an endogenous specific inhibitor of STAT3, which regulates the expression of proinflammatory cytokines. In this study, we investigated the influence of GRIM19 in a DSS induced colitis mouse model. We hypothesized that Grim19 would ameliorate DSS induced colitis by altering STAT3 activity and intestinal inflammation. Grim19 ameliorated DSS induced colitis severity and protected intestinal tissue. The expression of STAT3 and proinflammatory cytokines such as IL-1β and TNF-α in colon and lymph nodes was decreased significantly by Grim19. Moreover, DSS induced colitis progression in a Grim19 transgenic mouse line was inhibited in association with a reduction in STAT3 and IL-17 expression. These results suggest that Grim19 attenuates DSS induced colitis by suppressing the excessive inflammatory response mediated by STAT3 activation.

  7. Grim19 Attenuates DSS Induced Colitis in an Animal Model

    Science.gov (United States)

    Kim, Jae-kyung; Lee, Seung Hoon; Lee, Seon-Young; Kim, Eun-Kyung; Kwon, Jeong-Eun; Seo, Hyeon-Beom; Lee, Han Hee; Lee, Bo-In; Park, Sung-Hwan; Cho, Mi-La

    2016-01-01

    DSS induced colitis is a chronic inflammatory disease characterized by inflammation in the gastrointestinal tract, which destabilizes the gut and induces an uncontrolled immune response. Although DSS induced colitis is generally thought to develop as a result of an abnormally active intestinal immune system, its pathogenesis remains unclear. Gene associated with retinoid interferon induced mortality (Grim) 19 is an endogenous specific inhibitor of STAT3, which regulates the expression of proinflammatory cytokines. In this study, we investigated the influence of GRIM19 in a DSS induced colitis mouse model. We hypothesized that Grim19 would ameliorate DSS induced colitis by altering STAT3 activity and intestinal inflammation. Grim19 ameliorated DSS induced colitis severity and protected intestinal tissue. The expression of STAT3 and proinflammatory cytokines such as IL-1β and TNF-α in colon and lymph nodes was decreased significantly by Grim19. Moreover, DSS induced colitis progression in a Grim19 transgenic mouse line was inhibited in association with a reduction in STAT3 and IL-17 expression. These results suggest that Grim19 attenuates DSS induced colitis by suppressing the excessive inflammatory response mediated by STAT3 activation. PMID:27258062

  8. Radiative Transfer Model of Dust Attenuation Curves in Clumpy, Galactic Environments

    CERN Document Server

    Seon, Kwang-Il

    2016-01-01

    The attenuation of starlight by dust in galactic environments is investigated through models of radiative transfer in a spherical, clumpy ISM. Extinction properties for MW, LMC, and SMC dust types are considered. It is illustrated that the attenuation curves are primarily determined by the wavelength dependence of absorption rather than by the underlying extinction (absorption+scattering) curve. Attenuation curves consistent with the "Calzetti attenuation curve" are found by assuming the silicate-carbonaceous dust model for the MW, but with the 2175A absorption bump suppressed or absent. The discrepancy between our results and previous work that claimed the SMC-type dust to be the most likely origin of the Calzetti curve is ascribed to the difference in adopted albedos; this study uses the theoretically calculated albedos whereas the previous ones adopted empirically derived albedos from observations of reflection nebulae. It is also found that the model attenuation curves calculated with the MW dust are well...

  9. Study on p-Wave Attenuation in Hydrate-Bearing Sediments Based on BISQ Model

    Directory of Open Access Journals (Sweden)

    Chuanhui Li

    2013-01-01

    Full Text Available In hydrate-bearing sediments, the elastic wave attenuation characteristics depend on the elastic properties of the sediments themselves on the one hand, and on the other hand, they also depend on the hydrate occurrence state and hydrate saturation. Since the hydrate-bearing sediments always have high porosity, so they show significant porous medium characteristics. Based on the BISQ porous medium model which is the most widely used model to study the attenuation characteristics in the porous media, we focused on p-wave attenuation in hydrate-bearing sediments in Shenhu Area, South China Sea, especially in specific seismic frequency range, which lays a foundation for the identification of gas hydrates by using seismic wave attenuation in Shenhu Area, South China Sea. Our results depict that seismic wave attenuation is an effective attribute to identify gas hydrates.

  10. Nuclear Attenuation of high energy two-hadron system in the string model

    CERN Document Server

    Akopov, N; Akopov, Z

    2007-01-01

    Nuclear attenuation of the two-hadron system is considered in the string model. The two-scale model and its improved version with two different choices of constituent formation time and sets of parameters obtained earlier for the single hadron attenuation, are used to describe available experimental data for the $z$-dependence of subleading hadron, whereas satisfactory agreement with the experimental data has been observed. A model prediction for $\

  11. Nuclear Attenuation of high energy two-hadron system in the string model

    OpenAIRE

    Akopov, N.; Grigoryan, L.; Akopov, Z.(DESY, 22603 Hamburg, Germany)

    2006-01-01

    Nuclear attenuation of the two-hadron system is considered in the string model. The two-scale model and its improved version with two different choices of constituent formation time and sets of parameters obtained earlier for the single hadron attenuation, are used to describe available experimental data for the $z$-dependence of subleading hadron, whereas satisfactory agreement with the experimental data has been observed. A model prediction for $\

  12. On the impact of building attenuation models in urban VANET simulations

    OpenAIRE

    Luis Urquiza-Aguiar; Carolina Tripp-Barba; José Estrada-Jiménez; Mónica Aguilar Igartua

    2015-01-01

    Buildings are important elements of cities for VANETs, since these obstacles may attenuate communications between vehicles. Consequently, the impact of buildings has to be considered as part of the attenuation model in VANET simulations of urban scenarios. However, the more elaborated the model, the more information needs to be processed during the simulation, which implies longer processing times. This complexity in simulations is not always worth it, because simplified channel models occasi...

  13. Settlement prediction model of slurry suspension based on sedimentation rate attenuation

    Directory of Open Access Journals (Sweden)

    Shuai-jie GUO

    2012-03-01

    Full Text Available This paper introduces a slurry suspension settlement prediction model for cohesive sediment in a still water environment. With no sediment input and a still water environment condition, control forces between settling particles are significantly different in the process of sedimentation rate attenuation, and the settlement process includes the free sedimentation stage, the log-linear attenuation stage, and the stable consolidation stage according to sedimentation rate attenuation. Settlement equations for sedimentation height and time were established based on sedimentation rate attenuation properties of different sedimentation stages. Finally, a slurry suspension settlement prediction model based on slurry parameters was set up with a foundation being that the model parameters were determined by the basic parameters of slurry. The results of the settlement prediction model show good agreement with those of the settlement column experiment and reflect the main characteristics of cohesive sediment. The model can be applied to the prediction of cohesive soil settlement in still water environments.

  14. Introducing atmospheric attenuation within a diffusion model for room-acoustic predictions (L)

    OpenAIRE

    Billon, Alexis; Picaut, Judicaël; FOY, Cédric; Valeau, Vincent; SAKOUT, Anas

    2008-01-01

    This paper presents an extension of a diffusion model for room acoustics to handle the atmospheric attenuation. This phenomenon is critical at high frequencies and in large rooms to obtain correct acoustic predictions. An additional term is introduced in the diffusion equation as well as in the diffusion constant, in order to take the atmospheric attenuation into account. The modified diffusion model is then compared with the statistical theory and a cone-tracing software. Three typical room-...

  15. Rule-based modeling of transcriptional attenuation at the tryptophan operon

    OpenAIRE

    Kuttler, Céline; Lhoussaine, Cédric; Nebut, Mirabelle

    2010-01-01

    International audience Transcriptional attenuation at E.coli's tryptophan operon is a prime example of RNA-mediated gene regulation. In this paper, we present a discrete stochastic model of the fine-grained control of attenuation, based on chemical reactions. Stochastic simulation of our model confirms results that were previously obtained by master or differential equations. Our approach is easier to understand than master equations, although mathematically well founded. It is compact due...

  16. A blind deconvolution method for attenuative materials based on asymmetrical Gaussian model.

    Science.gov (United States)

    Jin, Haoran; Chen, Jian; Yang, Keji

    2016-08-01

    During propagation in attenuative materials, ultrasonic waves are distorted by frequency-dependent acoustic attenuation. As a result, reference signals for blind deconvolution in attenuative materials are asymmetrical and should be accurately estimated by considering attenuation. In this study, an asymmetrical Gaussian model is established to estimate the reference signals from these materials, and a blind deconvolution method based on this model is proposed. Based on the symmetrical Gaussian model, the asymmetrical one is formulated by adding an asymmetrical coefficient. Upon establishing the model, the reference signal for blind deconvolution is determined via maximum likelihood estimation, and the blind deconvolution is implemented with an orthogonal matching pursuit algorithm. To verify the feasibility of the established model, spectra of ultrasonic signals from attenuative polyethylene plates with different thicknesses are measured and estimated. The proposed blind deconvolution method is applied to the A-scan signal and B-scan image from attenuative materials. Results demonstrate that the proposed method is capable of separating overlapping echoes and therefore achieves a high temporal resolution. PMID:27586747

  17. A practical MGA-ARIMA model for forecasting real-time dynamic rain-induced attenuation

    Science.gov (United States)

    Gong, Shuhong; Gao, Yifeng; Shi, Houbao; Zhao, Ge

    2013-05-01

    novel and practical modified genetic algorithm (MGA)-autoregressive integrated moving average (ARIMA) model for forecasting real-time dynamic rain-induced attenuation has been established by combining genetic algorithm ideas with the ARIMA model. It is proved that due to the introduction of MGA into the ARIMA(1,1,7) model, the MGA-ARIMA model has the potential to be conveniently applied in every country or area by creating a parameter database used by the ARIMA(1,1,7) model. The parameter database is given in this paper based on attenuation data measured in Xi'an, China. The methods to create the parameter databases in other countries or areas are offered, too. Based on the experimental results, the MGA-ARIMA model has been proved practical for forecasting dynamic rain-induced attenuation in real time. The novel model given in this paper is significant for developing adaptive fade mitigation technologies at millimeter wave bands.

  18. Nonlinear Acoustics FDTD method including Frequency Power Law Attenuation for Soft Tissue Modeling

    CERN Document Server

    Jiménez, Noé; Sánchez-Morcillo, Víctor; Camarena, Francisco; Hou, Yi; Konofagou, Elisa E

    2014-01-01

    This paper describes a model for nonlinear acoustic wave propagation through absorbing and weakly dispersive media, and its numerical solution by means of finite differences in time domain method (FDTD). The attenuation is based on multiple relaxation processes, and provides frequency dependent absorption and dispersion without using computational expensive convolutional operators. In this way, by using an optimization algorithm the coefficients for the relaxation processes can be obtained in order to fit a frequency power law that agrees the experimentally measured attenuation data for heterogeneous media over the typical frequency range for ultrasound medical applications. Our results show that two relaxation processes are enough to fit attenuation data for most soft tissues in this frequency range including the fundamental and the first ten harmonics. Furthermore, this model can fit experimental attenuation data that do not follow exactly a frequency power law over the frequency range of interest. The main...

  19. Comparison of viscoelastic-type models for ocean wave attenuation in ice-covered seas

    Science.gov (United States)

    Mosig, Johannes E. M.; Montiel, Fabien; Squire, Vernon A.

    2015-09-01

    Continuum-based models that describe the propagation of ocean waves in ice-infested seas are considered, where the surface ocean layer (including ice floes, brash ice, etc.) is modeled by a homogeneous viscoelastic material which causes waves to attenuate as they travel through the medium. Three ice layer models are compared, namely a viscoelastic fluid layer model currently being trialed in the spectral wave model WAVEWATCH III® and two simpler viscoelastic thin beam models. All three models are two dimensional. A comparative analysis shows that one of the beam models provides similar predictions for wave attenuation and wavelength to the viscoelastic fluid model. The three models are calibrated using wave attenuation data recently collected in the Antarctic marginal ice zone as an example. Although agreement with the data is obtained with all three models, several important issues related to the viscoelastic fluid model are identified that raise questions about its suitability to characterize wave attenuation in ice-covered seas. Viscoelastic beam models appear to provide a more robust parameterization of the phenomenon being modeled, but still remain questionable as a valid characterization of wave-ice interactions generally.

  20. Using a LIDAR Vegetation Model to Predict UHF SAR Attenuation in Coniferous Forests

    Directory of Open Access Journals (Sweden)

    Alan Swanson

    2009-03-01

    Full Text Available Attenuation of radar signals by vegetation can be a problem for target detection and GPS reception, and is an important parameter in models describing vegetation backscatter. Here we first present a model describing the 3D distribution of stem and foliage structure based on small footprint scanning LIDAR data. Secondly we present a model that uses ray-tracing methodology to record detailed interactions between simulated radar beams and vegetation components. These interactions are combined over the SAR aperture and used to predict two-way attenuation of the SAR signal. Accuracy of the model is demonstrated using UHF SAR observations of large trihedral corner reflectors in coniferous forest stands. Our study showed that the model explains between 66% and 81% of the variability in observed attenuation.

  1. Telmisartan attenuates chronic ciclosporin A nephrotoxicity in a pig model

    DEFF Research Database (Denmark)

    Cibulskyte, Donata; pedersen, michael; Hørlyck, Arne;

    2007-01-01

    .064). A significant increase in renal volume was seen in both groups, but tended to be lower in the CsA + telmisartan pigs at 54 weeks (P = 0.097). Telmisartan did not reduce MAP, RBF or rGFR. CONCLUSIONS: Long-term CsA treatment causes histopathological changes in the porcine kidney similar to those observed...... in humans and results in renal enlargement. Telmisartan attenuates the CsA-induced histopathological changes and enlargement in the pig kidney.......BACKGROUND: We have previously demonstrated renal enlargement in pigs treated with ciclosporin A (CsA) 10 mg/kg/day orally for 6 months. The aim of the study was to investigate the effect of oral CsA (10 mg/kg/day) for 12 months on kidney structure and function and the potential renoprotective role...

  2. Sensitivity of modeled ocean heat content to errors in short wave radiation and its attenuation with depth

    Science.gov (United States)

    Shulman, Igor; Gould, Richard W.; Anderson, Stephanie; Sakalaukus, Peter

    2016-05-01

    Short wave radiation (SWR) and its attenuation with depth have a major impact on the vertical distribution of the oceanic water temperature, dynamical processes, and ocean-atmosphere interactions. In numerical modeling of oceanic processes, the SWR usually comes from the atmospheric model predictions, while the short wave attenuation schemes are internally prescribed (estimated) inside the oceanic dynamical model. It has been reported that atmospheric models show a tendency to overestimate the shortwave radiation due to underestimation of predicted low-level clouds. Most existing schemes to specify the attenuation of SWR with depth in numerical models are based on: the Jerlov (1976) water-types classification; climatological estimates of attenuation coefficients or from the biological model predictions of light-absorbing and scattering water constituents. All of the above attenuation schemes are prone to introducing errors in the attenuation of short wave radiation with depth. As a result, we have to deal with two types of errors in the oceanic modeling: those due to the incorrect specification of the magnitude of SWR at the surface (from the atmospheric model), and those due to inaccurate vertical attenuation of SWR (prescribed in the oceanic model). We have developed an approach for estimating errors in the oceanic model heat budget due to errors in surface values of SWR and in its attenuation with depth. Based on this approach, we present examples illustrating sensitivities of the heat budget of the water column to the changes in specification of surface SWR and its attenuation.

  3. Economic Game Theory to Model the Attenuation of Virulence of an Obligate Intracellular Bacterium.

    Science.gov (United States)

    Tago, Damian; Meyer, Damien F

    2016-01-01

    Diseases induced by obligate intracellular pathogens have a large burden on global human and animal health. Understanding the factors involved in the virulence and fitness of these pathogens contributes to the development of control strategies against these diseases. Based on biological observations, a theoretical model using game theory is proposed to explain how obligate intracellular bacteria interact with their host. The equilibrium in such a game shows that the virulence and fitness of the bacterium is host-triggered and by changing the host's defense system to which the bacterium is confronted, an evolutionary process leads to an attenuated strain. Although, the attenuation procedure has already been conducted in practice in order to develop an attenuated vaccine (e.g., with Ehrlichia ruminantium), there was a lack of understanding of the theoretical basis behind this process. Our work provides a model to better comprehend the existence of different phenotypes and some underlying evolutionary mechanisms for the virulence of obligate intracellular bacteria.

  4. Economic Game Theory to Model the Attenuation of Virulence of an Obligate Intracellular Bacterium

    Science.gov (United States)

    Tago, Damian; Meyer, Damien F.

    2016-01-01

    Diseases induced by obligate intracellular pathogens have a large burden on global human and animal health. Understanding the factors involved in the virulence and fitness of these pathogens contributes to the development of control strategies against these diseases. Based on biological observations, a theoretical model using game theory is proposed to explain how obligate intracellular bacteria interact with their host. The equilibrium in such a game shows that the virulence and fitness of the bacterium is host-triggered and by changing the host's defense system to which the bacterium is confronted, an evolutionary process leads to an attenuated strain. Although, the attenuation procedure has already been conducted in practice in order to develop an attenuated vaccine (e.g., with Ehrlichia ruminantium), there was a lack of understanding of the theoretical basis behind this process. Our work provides a model to better comprehend the existence of different phenotypes and some underlying evolutionary mechanisms for the virulence of obligate intracellular bacteria. PMID:27610355

  5. Economic Game Theory to Model the Attenuation of Virulence of an Obligate Intracellular Bacterium.

    Science.gov (United States)

    Tago, Damian; Meyer, Damien F

    2016-01-01

    Diseases induced by obligate intracellular pathogens have a large burden on global human and animal health. Understanding the factors involved in the virulence and fitness of these pathogens contributes to the development of control strategies against these diseases. Based on biological observations, a theoretical model using game theory is proposed to explain how obligate intracellular bacteria interact with their host. The equilibrium in such a game shows that the virulence and fitness of the bacterium is host-triggered and by changing the host's defense system to which the bacterium is confronted, an evolutionary process leads to an attenuated strain. Although, the attenuation procedure has already been conducted in practice in order to develop an attenuated vaccine (e.g., with Ehrlichia ruminantium), there was a lack of understanding of the theoretical basis behind this process. Our work provides a model to better comprehend the existence of different phenotypes and some underlying evolutionary mechanisms for the virulence of obligate intracellular bacteria. PMID:27610355

  6. Modeling of wave attenuation by vegetation with XBeach

    NARCIS (Netherlands)

    Van Rooijen, A.A.; Van Thiel de Vries, J.S.M.; McCall, R.T.; Van Dongeren, A.R.; Roelvink, J.A.; Reniers, A.J.H.M.

    2015-01-01

    Over the past decades the effect of vegetation (e.g. kelp, mangroves, sea grass) on nearshore coastal processes has received more and more attention. In recent years several numerical wave models have been extended to include this effect. In the current study, the numerical storm impact model XBeach

  7. A simple model for deep tissue attenuation correction and large organ analysis of Cerenkov luminescence imaging

    Science.gov (United States)

    Habte, Frezghi; Natarajan, Arutselvan; Paik, David S.; Gambhir, Sanjiv S.

    2014-03-01

    Cerenkov luminescence imaging (CLI) is an emerging cost effective modality that uses conventional small animal optical imaging systems and clinically available radionuclide probes for light emission. CLI has shown good correlation with PET for organs of high uptake such as kidney, spleen, thymus and subcutaneous tumors in mouse models. However, CLI has limitations for deep tissue quantitative imaging since the blue-weighted spectral characteristics of Cerenkov radiation attenuates highly by mammalian tissue. Large organs such as the liver have also shown higher signal due to the contribution of emission of light from a greater thickness of tissue. In this study, we developed a simple model that estimates the effective tissue attenuation coefficient in order to correct the CLI signal intensity with a priori estimated depth and thickness of specific organs. We used several thin slices of ham to build a phantom with realistic attenuation. We placed radionuclide sources inside the phantom at different tissue depths and imaged it using an IVIS Spectrum (Perkin-Elmer, Waltham, MA, USA) and Inveon microPET (Preclinical Solutions Siemens, Knoxville, TN). We also performed CLI and PET of mouse models and applied the proposed attenuation model to correct CLI measurements. Using calibration factors obtained from phantom study that converts the corrected CLI measurements to %ID/g, we obtained an average difference of less that 10% for spleen and less than 35% for liver compared to conventional PET measurements. Hence, the proposed model has a capability of correcting the CLI signal to provide comparable measurements with PET data.

  8. Therapeutic attenuation of mitochondrial dysfunction and oxidative stress in neurotoxin models of Parkinson's disease

    OpenAIRE

    Stack, Edward C.; Ferro, Joellyn L.; Kim, Jinho; Del Signore, Steven J.; Goodrich, Sarah; Matson, Samantha; Hunt, Bonnie B.; Cormier, Kerry; Smith, Karen; Matson, Wayne R.; Ryu, Hoon; Ferrante, Robert J.

    2008-01-01

    Therapeutic attenuation of mitochondrial dysfunction and oxidative stress in neurotoxin models of Parkinson?s disease correspondence: Corresponding author. GRECC Unit 182B, Bedford VA Medical Center, 200 Springs Road, Bedford, MA 01730, USA. Tel.: +1 781 687 2908; fax: +1 781 687 3515. (Ferrante, Robert J.) (Ferrante, Robert J.) Department of Neurology, Boston University School of Medicine - Boston--> , MA 02118--> ...

  9. Experimental Study and Numerical Modeling of Wave Induced Pore Pressure Attenuation Inside a Rubble Mound Breakwater

    DEFF Research Database (Denmark)

    Troch, Peter; Rouck, Julien De; Burcharth, Hans Falk

    2003-01-01

    attenuation is studied using experimental data (in Section 2) and using a numerical wave flume (in Section 3). The experimental study includes the analysis of large scale data from a physical breakwater model and prototype data from the Zeebrugge breakwater. The large scale data are taken from literature...

  10. The particle-rotor model and the coriolis attenuation problem in 163Er

    International Nuclear Information System (INIS)

    The energy spectrum of 163Er has been calculated within the particle-rotor model. Two approximations for the intrinsic motion have been studied: the BCS and the diagonalization method. It is shown that the positive parity i(sub 13/2) decoupled band can be reproduced using the diagonalization method without an ad-hoc attenuation factor. (Auth.)

  11. Key Considerations in the Modeling of Tropical Maritime Microwave Attenuations

    OpenAIRE

    Yee Hui Lee; Yu Song Meng

    2015-01-01

    This paper presents some key considerations for modeling of over-sea radio-wave propagations in 5 GHz band. The summarized information is based on a series of measurement campaigns which were recently carried out in the tropical maritime environments near Singapore. Multiray propagations and ducting of radio waves have been highlighted and considered in over-sea path loss modeling and prediction. It is noted that the sea-surface reflection is an important contribution in the received field, w...

  12. Radiation Background and Attenuation Model Validation and Development

    Energy Technology Data Exchange (ETDEWEB)

    Peplow, Douglas E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Santiago, Claudio P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-08-05

    This report describes the initial results of a study being conducted as part of the Urban Search Planning Tool project. The study is comparing the Urban Scene Simulator (USS), a one-dimensional (1D) radiation transport model developed at LLNL, with the three-dimensional (3D) radiation transport model from ORNL using the MCNP, SCALE/ORIGEN and SCALE/MAVRIC simulation codes. In this study, we have analyzed the differences between the two approaches at every step, from source term representation, to estimating flux and detector count rates at a fixed distance from a simple surface (slab), and at points throughout more complex 3D scenes.

  13. Key Considerations in the Modeling of Tropical Maritime Microwave Attenuations

    Directory of Open Access Journals (Sweden)

    Yee Hui Lee

    2015-01-01

    Full Text Available This paper presents some key considerations for modeling of over-sea radio-wave propagations in 5 GHz band. The summarized information is based on a series of measurement campaigns which were recently carried out in the tropical maritime environments near Singapore. Multiray propagations and ducting of radio waves have been highlighted and considered in over-sea path loss modeling and prediction. It is noted that the sea-surface reflection is an important contribution in the received field, while the duct layers could enhance the radio-wave propagations. Our studies also show that the refracted ray inside evaporation duct could be a strong ray for short-range near sea-surface applications and needs to be properly evaluated.

  14. An updated analytic model for the attenuation by the intergalactic medium

    CERN Document Server

    Inoue, Akio K; Iwata, Ikuru

    2014-01-01

    We present an updated version of the so-called Madau model for the attenuation by the intergalactic neutral hydrogen against the radiation from distant objects. First, we derive a distribution function of the intergalactic absorbers from the latest observational statistics of the Ly$\\alpha$ forest, Lyman limit systems, and damped Ly$\\alpha$ systems. The distribution function excellently reproduces the observed redshift evolutions of the Ly$\\alpha$ depression and of the mean-free-path of the Lyman continuum simultaneously. Then, we derive a set of the analytic functions which describe the mean intergalactic attenuation curve for objects at $z>0.5$. Our new model predicts, for some redshifts, more than 0.5--1 mag different attenuation magnitudes through usual broad-band filters relative to the original Madau model. Such a difference would cause uncertainty of the photometric redshift of 0.2, in particular, at $z\\simeq3$--4. Finally, we find a more than 0.5 mag overestimation of the Lyman continuum attenuation i...

  15. Prediction of heat recovery steam generator (HRSG) noise attenuation using scale model testing

    Energy Technology Data Exchange (ETDEWEB)

    Bracken, M.; Barman, M.; Gambino, V. [Aercoustics Engineering Limited, Toronto, ON (Canada)

    1996-08-01

    An investigation was undertaken to determine whether scale modelling was effective for the study of (1) reactive attenuation on the gas flow path of heat recovery steam generators (HRSGs), (2) attenuation due to diffusion and scattering of sound, and (3) propagation loss due to flow resistivity of the tube bundles. MIDAS, a state-of-the-art measurement system, suitable for use with small models, and a microphone capable of ultrasonic measurement, were used. The noise source used was supplied by a high voltage spark source. The methodology used in the study, and some of the initial results of the scale model testing were described. A review of the initial results showed that it will be possible to model reactive effects, viscous loss and diffusion and scattering. 2 refs., 1 fig.

  16. Pretreatment with Darbepoetin Attenuates Renal Injury in a Rat Model of Cisplatin-Induced Nephrotoxicity

    OpenAIRE

    Choi, Dae Eun; Jeong, Jin Young; Lim, Beom Jin; Lee, Kang Wook; Shin, Young-Tai; Na, Ki-Ryang

    2009-01-01

    Background/Aims Darbepoetin alfa (DPO) exhibits comparable renoprotective effects to erythropoietin (EPO) in several animal models of acute renal injury. We examined whether DPO also attenuated renal injury in a rat model of cisplatin nephrotoxicity. Methods Male Spague-Dawley rats were divided into four groups: untreated, DPO-treated, cisplatin-injected, and DPO-treated cisplatin-injected. DPO pretreatment was conducted 24 hours after and just before cisplatin administration. Ninety-six hour...

  17. Modeling future scenarios of light attenuation and potential seagrass success in a eutrophic estuary

    Science.gov (United States)

    del Barrio, Pilar; Ganju, Neil K.; Aretxabaleta, Alfredo L.; Hayn, Melanie; García, Andrés; Howarth, Robert W.

    2014-01-01

    Estuarine eutrophication has led to numerous ecological changes, including loss of seagrass beds. One potential cause of these losses is a reduction in light availability due to increased attenuation by phytoplankton. Future sea level rise will also tend to reduce light penetration and modify seagrass habitat. In the present study, we integrate a spectral irradiance model into a biogeochemical model coupled to the Regional Ocean Model System (ROMS). It is linked to a bio-optical seagrass model to assess potential seagrass habitat in a eutrophic estuary under future nitrate loading and sea-level rise scenarios. The model was applied to West Falmouth Harbor, a shallow estuary located on Cape Cod (Massachusetts) where nitrate from groundwater has led to eutrophication and seagrass loss in landward portions of the estuary. Measurements of chlorophyll, turbidity, light attenuation, and seagrass coverage were used to assess the model accuracy. Mean chlorophyll based on uncalibrated in-situ fluorometry varied from 28 μg L−1 at the landward-most site to 6.5 μg L−1 at the seaward site, while light attenuation ranged from 0.86 to 0.45 m-1. The model reproduced the spatial variability in chlorophyll and light attenuation with RMS errors of 3.72 μg L−1 and 0.07 m-1 respectively. Scenarios of future nitrate reduction and sea-level rise suggest an improvement in light climate in the landward basin with a 75% reduction in nitrate loading. This coupled model may be useful to assess habitat availability changes due to eutrophication and sediment resuspension and fully considers spatial variability on the tidal timescale.

  18. IRON PRECIPITATION AND ARSENIC ATTENUATION - ASSESSMENT OF ARSENIC NATURAL ATTENUATION OF THE SUBSURFACE USING A GEOCHEMICAL MODEL (PHREEQC)

    Science.gov (United States)

    Laboratory experiments show that amorphous and poorly crystallized ferric iron hydroxides have much greater capacity to attenuate arsenic compared to clays and other aluminosilicate minerals. Studies (e.g., Lin and Qvarfort, 1996) showed that a sudden change in geochemical condit...

  19. Ginsenoside Re Attenuates Neuroinflammation in a Symptomatic ALS Animal Model.

    Science.gov (United States)

    Cai, Mudan; Yang, Eun Jin

    2016-01-01

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by the progressive loss of upper and lower motor neurons, which cause paralysis and respiratory dysfunction. There is currently no permanently effective drug for patients with ALS. Ginsenoside Re (G-Re), one of the most active ingredients of ginseng, has pharmacological activities that affect a number of targets. To investigate the effects of G-Re on neuroinflammation, we used G-Re (2.5[Formula: see text][Formula: see text]g/g) at the Joksamni acupressure point (ST36) once every other day for one week. To evaluate G-Re function in symptomatic human-superoxide dismutase 1 (hSOD1[Formula: see text] transgenic mice, immunohistochemistry and Western blot analysis were performed with the spinal cord of symptomatic hSOD1(G93A) transgenic mice. Here, we report that G-Re exhibits potent neuroprotective effects against neuroinflammation in a murine model of ALS. G-Re treatment reduced the loss of motor neurons and active-microglia-related expression of Iba-1 in the spinal cord of symptomatic hSOD1(G93A) transgenic mice. In addition, compared with age-matched hSOD1(G93A) mice, G-Re-treated hSOD1(G93A) mice showed a significant reduction in expression of pro-inflammatory proteins such as CD14 and TNF-[Formula: see text] protein related to TLR4 signaling pathway. G-Re administration also led to a decrease in cell death-related phospho-p38 protein levels, and had an antioxidative effect by reducing HO1 expression. Together, our data suggest that G-Re could have potent anti-neuroinflammatory effects on ALS by inhibiting the TLR4 pathway. PMID:27080948

  20. A model for dependent default with hyperbolic attenuation effect and valuation of credit default swap

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A hyperbolic function is introduced to reflect the attenuation effect of one firm's default to its partner. If two firms are competitors (copartners), the default intensity of one firm will decrease (increase) abruptly when the other firm defaults. As time goes on, the impact will decrease gradually until extinct. In this model, the joint distribution and marginal distributions of default times are derived by employing the change of measure, and the fair swap premium of a credit default swap (CDS) can be valued.

  1. Azithromycin attenuates airway inflammation in a mouse model of viral bronchiolitis

    Directory of Open Access Journals (Sweden)

    Brody Steven L

    2010-06-01

    Full Text Available Abstract Background Viral bronchiolitis is the leading cause of hospitalization in young infants. It is associated with the development of childhood asthma and contributes to morbidity and mortality in the elderly. Currently no therapies effectively attenuate inflammation during the acute viral infection, or prevent the risk of post-viral asthma. We hypothesized that early treatment of a paramyxoviral bronchiolitis with azithromycin would attenuate acute and chronic airway inflammation. Methods Mice were inoculated with parainfluenza type 1, Sendai Virus (SeV, and treated daily with PBS or azithromycin for 7 days post-inoculation. On day 8 and 21 we assessed airway inflammation in lung tissue, and quantified immune cells and inflammatory mediators in bronchoalveolar lavage (BAL. Results Compared to treatment with PBS, azithromycin significantly attenuated post-viral weight loss. During the peak of acute inflammation (day 8, azithromycin decreased total leukocyte accumulation in the lung tissue and BAL, with the largest fold-reduction in BAL neutrophils. This decreased inflammation was independent of changes in viral load. Azithromycin significantly attenuated the concentration of BAL inflammatory mediators and enhanced resolution of chronic airway inflammation evident by decreased BAL inflammatory mediators on day 21. Conclusions In this mouse model of paramyxoviral bronchiolitis, azithromycin attenuated acute and chronic airway inflammation. These findings demonstrate anti-inflammatory effects of azithromycin that are not related to anti-viral activity. Our findings support the rationale for future prospective randomized clinical trials that will evaluate the effects of macrolides on acute viral bronchiolitis and their long-term consequences.

  2. Losartan attenuates renal interstitial fibrosis and tubular cell apoptosis in a rat model of obstructive nephropathy.

    Science.gov (United States)

    He, Ping; Li, Detian; Zhang, Beiru

    2014-08-01

    Ureteral obstruction leads to renal injury and progresses to irreversible renal fibrosis, with tubular cell atrophy and apoptosis. There is conflicting evidence concerning whether losartan (an angiotensin II type I receptor antagonist) mitigates renal interstitial fibrosis and renal tubular epithelial cell apoptosis following unilateral ureteral obstruction (UUO) in animal models. The aim of this study was to investigate the effect and mechanism of losartan on renal tubular cell apoptosis and renal fibrosis in a rat model of UUO. The rats were subjected to UUO by ureteral ligation and were treated with dimethyl sulfoxide (control) or losartan. The controls underwent sham surgery. The renal tissues were collected 3, 5, 7 and 14 days after surgery for measurement of various indicators of renal fibrosis. UUO increased the expression levels of α‑smooth muscle actin and collagen I, and the extent of renal tubular fibrosis and apoptosis in a time‑dependent manner. Losartan treatment partially attenuated these responses. Progression of renal interstitial fibrosis was accompanied by phosphorylation of signal transducer and activator of transcription 3 (STAT3) and altered the expression levels of two apoptosis‑related proteins (Bax and Bcl2). Losartan treatment also partially attenuated these responses. The results indicated that losartan attenuated renal fibrosis and renal tubular cell apoptosis in a rat model of UUO. This effect appeared to be mediated by partial blockage of STAT3 phosphorylation.

  3. Ultrasonic attenuation model for measuring particle size and inverse calculation of particle size distribution in mineral slurries

    Institute of Scientific and Technical Information of China (English)

    HE Gui-chun; NI Wen

    2006-01-01

    Based on various ultrasonic loss mechanisms, the formula of the cumulative mass percentage of minerals with different particle sizes was given, with which the particle size distribution was integrated into an ultrasonic attenuation model. And then the correlations between the ultrasonic attenuation and the pulp density, and the particle size were obtained. The derived model was combined with the experiment and the analysis of experimental data to determine the inverse model relating ultrasonic attenuation coefficient with size distribution. Finally, an optimization method of inverse parameter, genetic algorithm was applied for particle size distribution. The results of inverse calculation show that the precision of measurement was high.

  4. Economic game theory to model the attenuation of virulence of an obligate intracellular bacterium

    Directory of Open Access Journals (Sweden)

    Damian Tago

    2016-08-01

    Full Text Available Diseases induced by obligate intracellular pathogens have a large burden on global human and animal health. Understanding the factors involved in the virulence and fitness of these pathogens contributes to the development of control strategies against these diseases. Based on biological observations, a theoretical model using game theory is proposed to explain how obligate intracellular bacteria interact with their host. The equilibrium in such a game shows that the virulence and fitness of the bacterium is host-triggered and by changing the host’s defense system to which the bacterium is confronted, an evolutionary process leads to an attenuated strain. Although, the attenuation procedure has already been conducted in practice in order to develop an attenuated vaccine (e.g. with Ehrlichia ruminantium, there was a lack of understanding of the theoretical basis behind this process. Our work provides a model to better comprehend the existence of different phenotypes and some underlying evolutionary mechanisms for the virulence of obligate intracellular bacteria.

  5. Activation of farnesoid X receptor attenuates hepatic injury in a murine model of alcoholic liver disease

    International Nuclear Information System (INIS)

    Highlights: •FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. •Activation of FXR attenuated alcohol-induced liver injury and steatosis. •Activation of FXR attenuated cholestasis and oxidative stress in mouse liver. -- Abstract: Alcoholic liver disease (ALD) is a common cause of advanced liver disease, and considered as a major risk factor of morbidity and mortality worldwide. Hepatic cholestasis is a pathophysiological feature observed in all stages of ALD. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily, and plays an essential role in the regulation of bile acid, lipid and glucose homeostasis. However, the role of FXR in the pathogenesis and progression of ALD remains largely unknown. Mice were fed Lieber-DeCarli ethanol diet or an isocaloric control diet. We used a specific agonist of FXR WAY-362450 to study the effect of pharmacological activation of FXR in alcoholic liver disease. In this study, we demonstrated that FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR by specific agonist WAY-362450 protected mice from the development of ALD. We also found that WAY-362450 treatment rescued FXR activity, suppressed ethanol-induced Cyp2e1 up-regulation and attenuated oxidative stress in liver. Our results highlight a key role of FXR in the modulation of ALD development, and propose specific FXR agonists for the treatment of ALD patients

  6. Activation of farnesoid X receptor attenuates hepatic injury in a murine model of alcoholic liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Weibin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Science, Fudan University, Shanghai 200032 (China); Zhu, Bo; Peng, Xiaomin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Zhou, Meiling, E-mail: meilingzhou2012@gmail.com [Department of Radiology, Zhongshan Hospital of Fudan University and Shanghai Institute of Medical Imaging, Shanghai 200032 (China); Jia, Dongwei, E-mail: jiadongwei@fudan.edu.cn [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Gu, Jianxin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Science, Fudan University, Shanghai 200032 (China)

    2014-01-03

    Highlights: •FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. •Activation of FXR attenuated alcohol-induced liver injury and steatosis. •Activation of FXR attenuated cholestasis and oxidative stress in mouse liver. -- Abstract: Alcoholic liver disease (ALD) is a common cause of advanced liver disease, and considered as a major risk factor of morbidity and mortality worldwide. Hepatic cholestasis is a pathophysiological feature observed in all stages of ALD. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily, and plays an essential role in the regulation of bile acid, lipid and glucose homeostasis. However, the role of FXR in the pathogenesis and progression of ALD remains largely unknown. Mice were fed Lieber-DeCarli ethanol diet or an isocaloric control diet. We used a specific agonist of FXR WAY-362450 to study the effect of pharmacological activation of FXR in alcoholic liver disease. In this study, we demonstrated that FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR by specific agonist WAY-362450 protected mice from the development of ALD. We also found that WAY-362450 treatment rescued FXR activity, suppressed ethanol-induced Cyp2e1 up-regulation and attenuated oxidative stress in liver. Our results highlight a key role of FXR in the modulation of ALD development, and propose specific FXR agonists for the treatment of ALD patients.

  7. GENERALIZED ASYMMETRIC HYSTERESIS MODEL OF CONTROLLABLE MAGNETORHEOLOGICAL DAMPER FOR VEHICLE SUSPENSION ATTENUATION

    Institute of Scientific and Technical Information of China (English)

    Wang Enrong; Ma Xiaoqing; Su Chunyi; Rakheja Subhash

    2004-01-01

    A generalized model is synthesized to characterize the asymmetric hysteresis force-velocity (F-v) properties of the magneto-rheological (MR) fluids damper.The model is represented as a function of the command current,excitation frequency,and displacement amplitude,based on the symmetric and asymmetric sigmoid functions.The symmetric hysteresis damping properties of the controllable MR-damper and properties of the conventional passive hydraulic damper can also be described by the proposed model.The validity of the model is verified by experiments,which show that the results calculated from the model are consistent with the measured data.In addition,it is shown that the model applies to a wide vibration frequency range.The proposed model has potential application in vehicle suspension design employing the symmetry MR-damper,and also in developing the asymmetry MR-damper especially for the vehicle suspension attenuation.

  8. Vadose zone-attenuated artificial recharge for input to a ground water model.

    Science.gov (United States)

    Nichols, William E; Wurstner, Signe K; Eslinger, Paul W

    2007-01-01

    Accurate representation of artificial recharge is requisite to calibration of a ground water model of an unconfined aquifer for a semiarid or arid site with a vadose zone that imparts significant attenuation of liquid transmission and substantial anthropogenic liquid discharges. Under such circumstances, artificial recharge occurs in response to liquid disposal to the vadose zone in areas that are small relative to the ground water model domain. Natural recharge, in contrast, is spatially variable and occurs over the entire upper boundary of a typical unconfined ground water model. An improved technique for partitioning artificial recharge from simulated total recharge for inclusion in a ground water model is presented. The improved technique is applied using data from the semiarid Hanford Site. From 1944 until the late 1980s, when Hanford's mission was the production of nuclear materials, the quantities of liquid discharged from production facilities to the ground vastly exceeded natural recharge. Nearly all hydraulic head data available for use in calibrating a ground water model at this site were collected during this period or later, when the aquifer was under the diminishing influence of the massive water disposals. The vadose zone is typically 80 to 90 m thick at the Central Plateau where most production facilities were located at this semiarid site, and its attenuation of liquid transmission to the aquifer can be significant. The new technique is shown to improve the representation of artificial recharge and thereby contribute to improvement in the calibration of a site-wide ground water model.

  9. Analyzing Signal Attenuation in PFG Anomalous Diffusion via a Modified Gaussian Phase Distribution Approximation Based on Fractal Derivative Model

    CERN Document Server

    Lin, Guoxing

    2016-01-01

    Pulsed field gradient (PFG) has been increasingly employed to study anomalous diffusions in Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI). However, the analysis of PFG anomalous diffusion is complicated. In this paper, a fractal derivative model based modified Gaussian phase distribution method is proposed to describe PFG anomalous diffusion. By using the phase distribution obtained from the effective phase shift diffusion method based on fractal derivatives, and employing some of the traditional Gaussian phase distribution approximation techniques, a general signal attenuation expression for free fractional diffusion is derived. This expression describes a stretched exponential function based attenuation, which is distinct from both the exponential attenuation for normal diffusion obtained from conventional Gaussian phase distribution approximation, and the Mittag-Leffler function based attenuation for anomalous diffusion obtained from fractional derivative. The obtained signal attenu...

  10. Input-dependent wave attenuation in a critically-balanced model of cortex.

    Directory of Open Access Journals (Sweden)

    Xiao-Hu Yan

    Full Text Available A number of studies have suggested that many properties of brain activity can be understood in terms of critical systems. However it is still not known how the long-range susceptibilities characteristic of criticality arise in the living brain from its local connectivity structures. Here we prove that a dynamically critically-poised model of cortex acquires an infinitely-long ranged susceptibility in the absence of input. When an input is presented, the susceptibility attenuates exponentially as a function of distance, with an increasing spatial attenuation constant (i.e., decreasing range the larger the input. This is in direct agreement with recent results that show that waves of local field potential activity evoked by single spikes in primary visual cortex of cat and macaque attenuate with a characteristic length that also increases with decreasing contrast of the visual stimulus. A susceptibility that changes spatial range with input strength can be thought to implement an input-dependent spatial integration: when the input is large, no additional evidence is needed in addition to the local input; when the input is weak, evidence needs to be integrated over a larger spatial domain to achieve a decision. Such input-strength-dependent strategies have been demonstrated in visual processing. Our results suggest that input-strength dependent spatial integration may be a natural feature of a critically-balanced cortical network.

  11. Alphavirus mutator variants present host-specific defects and attenuation in mammalian and insect models.

    Directory of Open Access Journals (Sweden)

    Kathryn Rozen-Gagnon

    2014-01-01

    Full Text Available Arboviruses cycle through both vertebrates and invertebrates, which requires them to adapt to disparate hosts while maintaining genetic integrity during genome replication. To study the genetic mechanisms and determinants of these processes, we use chikungunya virus (CHIKV, a re-emerging human pathogen transmitted by the Aedes mosquito. We previously isolated a high fidelity (or antimutator polymerase variant, C483Y, which had decreased fitness in both mammalian and mosquito hosts, suggesting this residue may be a key molecular determinant. To further investigate effects of position 483 on RNA-dependent RNA-polymerase (RdRp fidelity, we substituted every amino acid at this position. We isolated novel mutators with decreased replication fidelity and higher mutation frequencies, allowing us to examine the fitness of error-prone arbovirus variants. Although CHIKV mutators displayed no major replication defects in mammalian cell culture, they had reduced specific infectivity and were attenuated in vivo. Unexpectedly, mutator phenotypes were suppressed in mosquito cells and the variants exhibited significant defects in RNA synthesis. Consequently, these replication defects resulted in strong selection for reversion during infection of mosquitoes. Since residue 483 is conserved among alphaviruses, we examined the analogous mutations in Sindbis virus (SINV, which also reduced polymerase fidelity and generated replication defects in mosquito cells. However, replication defects were mosquito cell-specific and were not observed in Drosophila S2 cells, allowing us to evaluate the potential attenuation of mutators in insect models where pressure for reversion was absent. Indeed, the SINV mutator variant was attenuated in fruit flies. These findings confirm that residue 483 is a determinant regulating alphavirus polymerase fidelity and demonstrate proof of principle that arboviruses can be attenuated in mammalian and insect hosts by reducing fidelity.

  12. Numerical investigation of wave attenuation by vegetation using a 3D RANS model

    Science.gov (United States)

    Marsooli, Reza; Wu, Weiming

    2014-12-01

    Vegetation has been recognized as an important natural shoreline protection against storm surges and waves. Understanding of wave-vegetation interaction is essential for assessing the ability of vegetation patches, such as wetlands, to mitigate storm damages. In this study the wave attenuation by vegetation is investigated numerically using a 3-D model which solves the Reynolds-Averaged Navier-Stokes equations (RANS) by means of a finite-volume method based on collocated hexahedron mesh. A mixing length model is used for turbulence closure of the RANS equations. The water surface boundary is tracked using the Volume-of-Fluid (VOF) method with the Compressive Interface Capturing Scheme for Arbitrary Meshes (CICSAM) to solve the VOF advection equation. The presence of vegetation is taken into account by adding the vegetation drag and inertia forces to the momentum equations. The model is validated by several laboratory experiments of short wave propagation through vegetation over flat and sloping beds. The comparisons show good agreement between the measured data and calculated results, but the swaying motion of flexible vegetation which is neglected in this study can influence the accuracy of the wave height predictions. The model is then applied to one of the validation tests with different vegetation properties, revealing that the wave height attenuation by vegetation depends not only on the wave conditions, but also the vegetation characteristics such as vegetation height and density.

  13. Paroxetine Attenuates the Development and Existing Pain in a Rat Model of Neurophatic Pain

    OpenAIRE

    Zarei, Malek; Sabetkasaei, Masoumeh; Moini Zanjani, Taraneh

    2014-01-01

    Background: P2X4 receptor (P2X4R), a purinoceptor expressed in activated spinal microglia, plays a key role in the pathogenesis of neuropathic pain. Spinal nerve injury induces up-regulation of P2X4R on activated microglia in the spinal cord, and blockade of this receptor can reduce neuropathic pain. The present study was undertaken to determine whether paroxetine, an inhibitor of P2X4R, could attenuate allodynia and hyperalgesia in chronic constriction injury (CCI) model of neuropathic pain ...

  14. Alpha 1 Antitrypsin Inhibits Dendritic Cell Activation and Attenuates Nephritis in a Mouse Model of Lupus.

    Science.gov (United States)

    Elshikha, Ahmed S; Lu, Yuanqing; Chen, Mong-Jen; Akbar, Mohammad; Zeumer, Leilani; Ritter, Andrea; Elghamry, Hanaa; Mahdi, Mahmoud A; Morel, Laurence; Song, Sihong

    2016-01-01

    Systemic lupus erythematosus (SLE) is an autoimmune disorder with a worldwide distribution and considerable mortality and morbidity. Although the pathogenesis of this disease remains elusive, over-reactive dendritic cells (DCs) play a critical role in the disease development. It has been shown that human alpha-1 antitrypsin (hAAT) has protective effects in type 1 diabetes and rheumatoid arthritis mouse models. In the present study, we tested the effect of AAT on DC differentiation and functions, as well as its protective effect in a lupus-prone mouse model. We showed that hAAT treatment significantly inhibited LPS (TLR4 agonist) and CpG (TLR9 agonist) -induced bone-marrow (BM)-derived conventional and plasmacytoid DC (cDC and pDC) activation and reduced the production of inflammatory cytokines including IFN-I, TNF-α and IL-1β. In MRL/lpr mice, hAAT treatment significantly reduced BM-derived DC differentiation, serum autoantibody levels, and importantly attenuated renal pathology. Our results for the first time demonstrate that hAAT inhibits DC activation and function, and it also attenuates autoimmunity and renal damage in the MRL/lpr lupus model. These results imply that hAAT has a therapeutic potential for the treatment of SLE in humans. PMID:27232337

  15. Assessment Of Coronary Artery Aneurysms Using Transluminal Attenuation Gradient And Computational Modeling In Kawasaki Disease Patients

    Science.gov (United States)

    Grande Gutierrez, Noelia; Kahn, Andrew; Shirinsky, Olga; Gagarina, Nina; Lyskina, Galina; Fukazawa, Ryuji; Owaga, Shunichi; Burns, Jane; Marsden, Alison

    2015-11-01

    Kawasaki Disease (KD) can result in coronary artery aneurysms (CAA) in up to 25% of patients, putting them at risk of thrombus formation, myocardial infarction and sudden death. Clinical guidelines recommend CAA diameter >8 mm as the arbitrary criterion for initiating systemic anticoagulation. KD patient specific modeling and flow simulations suggest that hemodynamic data can predict regions at increased risk of thrombosis. Transluminal Attenuation Gradient (TAG) is determined from the change in radiological attenuation per vessel length and has been proposed as a non-invasive method for characterizing coronary stenosis from CT Angiography. We hypothesized that CAA abnormal flow could be quantified using TAG. We computed hemodynamics for patient specific coronary models using a stabilized finite element method, coupled numerically to a lumped parameter network to model the heart and vascular boundary conditions. TAG was quantified in the major coronary arteries. We compared TAG for aneurysmal and normal arteries and we analyzed TAG correlation with hemodynamic and geometrical parameters. Our results suggest that TAG may provide hemodynamic data not available from anatomy alone. TAG represents a possible extension to standard CTA that could help to better evaluate the risk of thrombus formation in KD.

  16. Modeling the attenuated total reflectance infrared (ATR-FTIR) spectrum of apatite

    Science.gov (United States)

    Aufort, Julie; Ségalen, Loïc; Gervais, Christel; Brouder, Christian; Balan, Etienne

    2016-06-01

    Attenuated total reflectance (ATR) infrared spectra were measured on a synthetic and a natural fluorapatite sample. A modeling approach based on the computation of the Fresnel reflection coefficient between the ATR crystal and the powder sample was used to analyze the line shape of the spectra. The dielectric properties of the samples were related to those of pure fluorapatite using an effective medium approach, based on Maxwell-Garnett and Bruggeman models. The Bruggeman effective medium model leads to a very good agreement with the experimental data recorded on the synthetic fluorapatite sample. The poorer agreement observed on the natural sample suggests a more significant heterogeneity of the sample at a characteristic length scale larger than the mid-infrared characteristic wavelength, i.e., about 10 micrometers. The results demonstrate the prominent role of macroscopic electrostatic effects over fine details of the microscopic structure in determining the line shape of strong ATR bands.

  17. Modelling of 3D Attenuation Structure in the Mantle Using a Waveform Approach: Successes and Challenges

    Science.gov (United States)

    Romanowicz, B. A.; Gung, Y.

    2003-12-01

    The study of lateral variations in Q in the upper mantle at the global scale is generally addressed using isolated phases in the seismogram (for example fundamental mode surface wave spectra), which limits the sampling and therefore the resolution of Q structure that can be achieved. The use of isolated phases has the advantage of working directly with amplitudes, thus making it easier to detect contamination of the anelastic attenuation signal by elastic focusing and scattering, a key problem in attenuation tomography. We here discuss recent progress on a waveform modeling approach, which allows us to work with entire seismograms and exploit the information contained both in fundamental mode surface waves, overtones and body waves. The method is based on a normal mode approach and proceeds iteratively. In the first step, we invert for 3D elastic structure using the NACT approach (Non-linear Asymptotic Coupling Theory; Li and Romanowicz, 1995), which aligns the phase part of the observed and synthetic seismograms. In the second step, we invert for Q. The crucial issue is how to account for elastic effects in the amplitudes (focusing)- we discuss asymptotic versus more exact methods to address this problem and illustrate the effects on the resulting models. We discuss prominent features in the lateral variations in Q in the upper mantle, their evolution with depth, and their relation with elastic structure, in particular from the point of view of resolving upwellings and the large scale signature of plumes.

  18. Neuritin attenuates cognitive function impairments in tg2576 mouse model of Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Yoori Choi

    Full Text Available Neuritin, also known as CPG15, is a neurotrophic factor that was initially discovered in a screen to identify genes involved in activity-dependent synaptic plasticity. Neuritin plays multiple roles in the process of neural development and synaptic plasticity, although its binding receptor(s and downstream signaling effectors remain unclear. In this study, we found that the cortical and hippocampal expression of neuritin is reduced in the brains of Alzheimer's disease (AD patients and demonstrated that viral-mediated expression of neuritin in the dentate gyrus of 13-month-old Tg2576 mice, an AD animal model, attenuated a deficit in learning and memory as assessed by a Morris water maze test. We also found that neuritin restored the reduction in dendritic spine density and the maturity of individual spines in primary hippocampal neuron cultures prepared from Tg2576 mice. It was also shown that viral-mediated expression of neuritin in the dentate gyrus of 7-week-old Sprague-Dawley rats increased neurogenesis in the hippocampus. Taken together, our results demonstrate that neuritin restores the reduction in dendritic spine density and the maturity of individual spines in primary hippocampal neurons from Tg2576 neurons, and also attenuates cognitive function deficits in Tg2576 mouse model of AD, suggesting that neuritin possesses a therapeutic potential for AD.

  19. Neuritin attenuates cognitive function impairments in tg2576 mouse model of Alzheimer's disease.

    Science.gov (United States)

    Choi, Yoori; Lee, Kihwan; Ryu, Junghwa; Kim, Hyoun Geun; Jeong, A Young; Woo, Ran-Sook; Lee, Jun-Ho; Hyun, Jin Won; Hahn, Seokyung; Kim, Joung-Hun; Kim, Hye-Sun

    2014-01-01

    Neuritin, also known as CPG15, is a neurotrophic factor that was initially discovered in a screen to identify genes involved in activity-dependent synaptic plasticity. Neuritin plays multiple roles in the process of neural development and synaptic plasticity, although its binding receptor(s) and downstream signaling effectors remain unclear. In this study, we found that the cortical and hippocampal expression of neuritin is reduced in the brains of Alzheimer's disease (AD) patients and demonstrated that viral-mediated expression of neuritin in the dentate gyrus of 13-month-old Tg2576 mice, an AD animal model, attenuated a deficit in learning and memory as assessed by a Morris water maze test. We also found that neuritin restored the reduction in dendritic spine density and the maturity of individual spines in primary hippocampal neuron cultures prepared from Tg2576 mice. It was also shown that viral-mediated expression of neuritin in the dentate gyrus of 7-week-old Sprague-Dawley rats increased neurogenesis in the hippocampus. Taken together, our results demonstrate that neuritin restores the reduction in dendritic spine density and the maturity of individual spines in primary hippocampal neurons from Tg2576 neurons, and also attenuates cognitive function deficits in Tg2576 mouse model of AD, suggesting that neuritin possesses a therapeutic potential for AD. PMID:25101829

  20. Hyperoxygenation attenuated a murine model of atopic dermatitis through raising skin level of ROS.

    Directory of Open Access Journals (Sweden)

    Hyung-Ran Kim

    Full Text Available Atopic dermatitis (AD is a chronic inflammatory skin disease resulting from excessive stimulation of immune cells. Traditionally, reactive oxygen species (ROS have been implicated in the progression of inflammatory diseases, but several opposing observations suggest the protective role of ROS in inflammatory disease. Recently, we demonstrated ROS prevented imiquimod-induced psoriatic dermatitis through enhancing regulatory T cell function. Thus, we hypothesized AD might also be attenuated in elevated levels of ROS through tissue hyperoxygenation, such as by hyperbaric oxygen therapy (HBOT or applying an oxygen-carrying chemical, perfluorodecalin (PFD. Elevated levels of ROS in the skin have been demonstrated directly by staining with dihydroethidum as well as indirectly by immunohistochemistry (IHC for indoleamine 2,3-dioxygenase (IDO. A murine model of AD was developed by repeated application of a chemical irritant (1% 2,4-dinitrochlorobenzene and house dust mite (Dermatophagoide farinae extract on one ear of BALB/c mice. The results showed treatment with HBOT or PFD significantly attenuated AD, comparably with 0.1% prednicarbate without any signs of side effects, such as telangiectasia. The expressions of interleukin-17A and interferon-γ were also decreased in the AD lesions by treatment with HBOT or PFD. Enhanced expression of IDO and reduced level of hypoxia-inducible factor-1α, in association with increased frequency of FoxP3+ regulatory T cells in the AD lesions, might be involved in the underlying mechanism of oxygen therapy. Taken together, it was suggested that tissue hyperoxygenation, by HBOT or treatment with PFD, might attenuate AD through enhancing skin ROS level.

  1. Evaluation of a bilinear model for attenuation correction using CT numbers generated from a parametric method.

    Science.gov (United States)

    Martinez, L C; Calzado, A

    2016-01-01

    A parametric model is used for the calculation of the CT number of some selected human tissues of known compositions (Hi) in two hybrid systems, one SPECT-CT and one PET-CT. Only one well characterized substance, not necessarily tissue-like, needs to be scanned with the protocol of interest. The linear attenuation coefficients of these tissues for some energies of interest (μ(i)) have been calculated from their tabulated compositions and the NIST databases. These coefficients have been compared with those calculated with the bilinear model from the CT number (μ(B)i). No relevant differences have been found for bones and lung. In the soft tissue region, the differences can be up to 5%. These discrepancies are attributed to the different chemical composition for the tissues assumed by both methods.

  2. Restoring Spinal Noradrenergic Inhibitory Tone Attenuates Pain Hypersensitivity in a Rat Model of Parkinson's Disease

    Science.gov (United States)

    Wang, Bing; Chen, Li-Hua

    2016-01-01

    In the present study, we investigated whether restoring descending noradrenergic inhibitory tone can attenuate pain in a PD rat model, which was established by stereotaxic infusion of 6-hydroxydopamine (6-OHDA) into the bilateral striatum (CPu). PD rats developed thermal and mechanical hypersensitivity at the 4th week after surgery. HPLC analysis showed that NE content, but not dopamine or 5-HT, significantly decreased in lumbar spinal cord in PD rats. Additional noradrenergic depletion by injection of N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) aggravated pain hypersensitivity in PD rats. At the 5th week after injection of 6-OHDA, systemic treatment with pharmacological norepinephrine (NE) precursor droxidopa (L-DOPS) or α2 adrenoceptor agonist clonidine significantly attenuated thermal and mechanical pain hypersensitivity in PD rats. Furthermore, application of norepinephrine (NE) and 5-hydroxytryptamine (5-HT) reuptake inhibitors duloxetine, but not 5-HT selective reuptake inhibitors sertraline, significantly inhibited thermal and mechanical pain hypersensitivity in PD rats. Systemic administration of Madopar (L-DOPA) or the D2/D3 agonist pramipexole slightly inhibited the thermal, but not mechanical, hypersensitivity in PD rats. Thus, our study revealed that impairment of descending noradrenergic system may play a key role in PD-associated pain and restoring spinal noradrenergic inhibitory tone may serve as a novel strategy to manage PD-associated pain. PMID:27747105

  3. The attenuation of concentrations model: a new method for assessing mercury mobility in sediments

    Directory of Open Access Journals (Sweden)

    Julio C. Wasserman

    2004-02-01

    Full Text Available In this work we propose a new approach for the determination of the mobility of mercury in sediments based on spatial distribution of concentrations. We chose the Tainheiros Cove, located in the Todos os Santos Bay, Brazil, as the study area, for it has a history of mercury contamination due to a chloro-alkali plant that was active during 12 years. Twenty-six surface sediment samples were collected from the area and mercury concentrations were measured by cold vapour atomic absorption spectrophotometry. A contour map was constructed from the results, indicating that mercury accumulated in a "hot spot" where concentrations reach more than 1 µg g-1. The model is able to estimate mobility of mercury in the sediments based on the distances between iso-concentration contours that determines an attenuation of concentrations factor. Values of attenuation ranged between 0.0729 (East of the hot spot, indicating higher mobility to 0.7727 (North of the hot spot, indicating lower mobility.

  4. Oligomannan Prebiotic Attenuates Immunological, Clinical and Behavioral Symptoms in Mouse Model of Inflammatory Bowel Disease

    Science.gov (United States)

    Ferenczi, Szilamér; Szegi, Krisztián; Winkler, Zsuzsanna; Barna, Teréz; Kovács, Krisztina J.

    2016-01-01

    Inflammatory bowel disease shows increasing prevalence, however its pathomechanism and treatment is not fully resolved. Prebiotics are non-digestible carbohydrates which might provide an alternative to treat inflammatory conditions in the gut due to their positive effects either on the microbiome or through their direct effect on macrophages and mucosa. To test the protective effects of an oligomannan prebiotic, yeast cell wall mannooligosaccharide (MOS) was administered in dextran-sulphate-sodium (DSS)-induced mouse model of acute colitis. MOS reduced DSS-induced clinical- (weight loss, diarrhea) and histological scores (mucosal damage) as well as sickness-related anxiety. DSS treatment resulted in changes in colon microbiome with selective increase of Coliform bacteria. MOS administration attenuated colitis-related increase of Coliforms, normalized colonic muc2 expression and attenuated local expression of proinflammatory cytokines IL-1a, IL1b, IL6, KC, G-CSF and MCP1 as well as toll-like receptor TLR4 and NLRP3 inflammasome. Some of the protective effects of MOS were likely be mediated directly through local macrophages because MOS dose-dependently inhibited IL-1b and G-CSF induction following in vitro DSS challenge and IL1a, IL1b, G-SCF-, and IL6 increases after LPS treatment in mouse macrophage cell line RAW264.7. These results highlight oligomannan prebiotics as therapeutic functional food for testing in clinical trials. PMID:27658624

  5. Valproic acid attenuates the multiple-organ dysfunction in a rat model of septic shock

    Institute of Scientific and Technical Information of China (English)

    SHANG You; JIANG Yuan-xu; Ding Ze-jun; Shen Ai-ling; XU San-peng; YUAN Shi-ying; YAO Shang-long

    2010-01-01

    Background Valproic acid (VPA) improves early survival and organ function in a highly lethal poly-trauma and hemorrhagic shock model or other severe insults. We assessed whether VPA could improve organ function in a rat model of septic shock and illustrated the possible mechanisms.Methods Forty Sprague-Dawley rats were randomly assigned to four groups (n=10): control group, VPA group, LPS group, and LPS+VPA group. Lipopolysaccharide (LPS) (10 mg/kg) was injected intravenously to replicate the experimental model of septic shock. Rats were treated with VPA (300 mg/kg, i.v.) or saline. Six hours after LPS injection,blood was sampled for gas analysis, measurement of serum alanine aminotransferase, aspartate aminotransferase,urine nitrogen, creatinine and tumor necrosis factor-alpha. Lung, liver and kidney were collected for histopathological assessment. In addition, myeloperoxidase activity and tumor necrosis factor-α in pulmonary tissue were measured.Acetylation of histone H3 in lung was also evaluated by Western blotting.Results LPS resulted in a significant decrease in PaO2, which was increased by VPA administration followed LPS injection. In addition, LPS also induced an increase in the serum levels of alanine aminotransferase, aspartate aminotransferase, urine nitrogen, creatinine, and tumor necrosis factor-alpha. However, these increases were attenuated in the LPS+VPA group. The lungs, liver and kidneys from the LPS group were significantly damaged compared with the control group. However, the damage was attenuated in the LPS+VPA group. Myeloperoxidase activity and tumor necrosis factor-alpha levels in pulmonary tissue increased significantly in the LPS group compared with the control group. These increases were significantly inhibited in the LPS+VPA group. Acetylation of histone H3 in lung tissue in the LPS group was inhibited compared with the control. However, the level of acetylation of histone H3 in the LPS+VPA group was markedly elevated in contrast to the

  6. Granulocyte colony stimulating factor attenuates inflammation in a mouse model of amyotrophic lateral sclerosis

    Directory of Open Access Journals (Sweden)

    Giniatullina Raisa

    2011-06-01

    Full Text Available Abstract Background Granulocyte colony stimulating factor (GCSF is protective in animal models of various neurodegenerative diseases. We investigated whether pegfilgrastim, GCSF with sustained action, is protective in a mouse model of amyotrophic lateral sclerosis (ALS. ALS is a fatal neurodegenerative disease with manifestations of upper and lower motoneuron death and muscle atrophy accompanied by inflammation in the CNS and periphery. Methods Human mutant G93A superoxide dismutase (SOD1 ALS mice were treated with pegfilgrastim starting at the presymptomatic stage and continued until the end stage. After long-term pegfilgrastim treatment, the inflammation status was defined in the spinal cord and peripheral tissues including hematopoietic organs and muscle. The effect of GCSF on spinal cord neuron survival and microglia, bone marrow and spleen monocyte activation was assessed in vitro. Results Long-term pegfilgrastim treatment prolonged mutant SOD1 mice survival and attenuated both astro- and microgliosis in the spinal cord. Pegfilgrastim in SOD1 mice modulated the inflammatory cell populations in the bone marrow and spleen and reduced the production of pro-inflammatory cytokine in monocytes and microglia. The mobilization of hematopoietic stem cells into the circulation was restored back to basal level after long-term pegfilgrastim treatment in SOD1 mice while the storage of Ly6C expressing monocytes in the bone marrow and spleen remained elevated. After pegfilgrastim treatment, an increased proportion of these cells in the degenerative muscle was detected at the end stage of ALS. Conclusions GCSF attenuated inflammation in the CNS and the periphery in a mouse model of ALS and thereby delayed the progression of the disease. This mechanism of action targeting inflammation provides a new perspective of the usage of GCSF in the treatment of ALS.

  7. A model for strong attenuation and dispersion of seismic P-waves in a partially saturated fractured reservoir

    Institute of Scientific and Technical Information of China (English)

    BRAJANOVSKI; Miroslav; MüLLER; Tobias; M; PARRA; Jorge; O

    2010-01-01

    In this work we interpret the data showing unusually strong velocity dispersion of P-waves (up to 30%) and attenuation in a relatively narrow frequency range. The cross-hole and VSP data were measured in a reservoir, which is in the porous zone of the Silurian Kankakee Limestone Formation formed by vertical fractures within a porous matrix saturated by oil, and gas patches. Such a medium exhibits significant attenuation due to wave-induced fluid flow across the interfaces between different types of inclusions (fractures, fluid patches) and background. Other models of intrinsic attenuation (in particular squirt flow models) cannot explain the amount of observed dispersion when using realistic rock properties. In order to interpret data in a satisfactory way we develop a superposition model for fractured porous rocks accounting also for the patchy saturation effect.

  8. PREDICTING ATTENUATION OF VIRUSES DURING PERCOLATION IN SOILS: 2. USER'S GUIDE TO THE VIRULO 1.0 COMPUTER MODEL

    Science.gov (United States)

    In the EPA document Predicting Attenuation of Viruses During Percolation in Soils 1. Probabilistic Model the conceptual, theoretical, and mathematical foundations for a predictive screening model were presented. In this current volume we present a User's Guide for the computer mo...

  9. Neuregulin-1 attenuates mitochondrial dysfunction in a rat model of heart failure

    Institute of Scientific and Technical Information of China (English)

    GUO Yong-fang; ZHANG Xiao-xia; LIU Yong; DUAN Hong-yan; JIE Bing-zhang; WU Xue-si

    2012-01-01

    Background Mitochondrial dysfunction plays a pivotal role in the progression of left ventricular (LV) remodeling and heart failure (HF).Recombinant human neuregulin-1 (rhNRG-1)improves cardiac function in models of experimental HF and in clinical trials; however,its impact on mitochondrial function during chronic HF remains largely unknown.The purpose of this study was to investigate whether rhNRG-1 could attenuate the functional and structural changes that occur in cardiac mitochondria in a rat model of HF induced by myocardial infarction.Methods Sixty adult rats underwent sham or coronary ligation to induce HF.Four weeks after ligation,29 animals with LV ejective fraction <50% were randomized to receive either vehicle or rhNRG-1 (10 μg·kg-1·d-1,I.V.) for 10 days,another 12 sham-operated animals were given no treatment.Echocardiography was used to determine physiological changes.Mitochondrial membrane potential (MMP),respiratory function and tissue adenosine triphosphate (ATP) production were analyzed.Cytochrome c expression and cardiomyocyte apoptosis were determined.Oxidative stress was evaluated by reactive oxygen species production using fluorescence assays and gene expression of glutathione peroxidase measured by real-time quantitative PCR.Results Compared with sham-operated animals,vehicle treated HF rats exhibited severe LV remodeling and dysfunction,significant mitochondrial dysfunction,increased mitochondrial cytochrome c release,increased myocyte apoptosis and enhanced oxidative stress.Short-term treatment with rhNRG-1 significantly attenuated LV remodeling and cardiac function.Concomitant with this change,mitochondrial dysfunction was significantly attenuated; with ATP production,MMP and respiratory function restored,cytochrome c release and apoptosis inhibited,and oxidative stress reduced.Conclusion The present study demonstrated that rhNRG-1 can significantly improve LV remodeling and cardiac function in the failing heart,this beneficial effect

  10. Small interference RNA targeting vascular endothelial growth factor gene effectively attenuates retinal neovascularization in mice model

    Institute of Scientific and Technical Information of China (English)

    KONG Yi-chun; SUN Bei; ZHAO Kan-xing; HAN Mei; WANG Yu-chuan

    2013-01-01

    Background The mechanism of retinal neovascularization is not understood completely.Many growth factors are involved in the process of retinal neovascularization,such as vascular endothelial growth factor (VEGF) and pigment epithelium-deprived factor (PEDF),which are the representatives of angiogenic and antiangiogenic molecules respectively.Oxygen induced retinopathy (OIR) is a useful model to investigate retinal neovascularization.The present study was conducted to investigate the feasibility of small interference RNA (siRNA) targeting VEGF gene in attenuating oxygen induced retinopathy (OIR) by regulating VEGF to PEDF ratio (VEGF/PEDF).Methods In vitro,cultured EOMA cells were transfected with VEGF-siRNA (psi-HITM/EGFPNEGF siRNA) and LipofectamineTM 2000 for 24,48,and 72 hours,respectively.Expression of VEGF mRNA was evaluated by real time polymerase chain reaction (PCR) and the level of VEGF protein was analyzed by Western blotting.In vivo,OIR model mice were established,the mice (C57BL/6J) received an intra-vitreal injection of 1 μl of mixture of psi-HITM/EGFPNEGF siRNA and Lipofectamine 2000.Expressions of retinal VEGF and PEDF protein were measured by Western blotting,retinal neovascularization was observed by fluorescein angiography,and quantified.Results In vitro psi-HITM/EGFP/VEGF siRNA treatment significantly reduced VEGF mRNA and protein expression.In vivo,with decreased VEGF and VEGF-PEDF ratio,significant attenuation of neovascular tufts,avascular regions,tortuous,and dilated blood vessels were observed in the interfered animals.Conclusions VEGF plays an important role in OIR,and the transfection of VEGF-siRNA can effectively downregulate VEGF expression in vivo,accompanied by the downregulation of VEGF-PEDF ratio,and simultaneous attenuation of retinal neovascularization was also observed.These findings suggest that VEGF/PEDF may serve as a potential target in the treatment of retinal neovascularization and RNA interference targeting VEGF expression

  11. STRATEGIC MODEL TO ATTENUATE THE RURAL INEQUALITIES IN THE SOUTH – WEST REGION

    Directory of Open Access Journals (Sweden)

    EMILIA UNGUREANU

    2011-01-01

    Full Text Available In the achievement of the work „Strategic Model to Attenuate the Rural Inequalities in the South – West Region” we took into consideration the performance of two types of objectives: main and specific ones. Within the general objectives we considered: developing theoretical approach to combat the rural inequalities; strategic plans addressed to combat the rural inequalities and identifying the socio-economic strategic measures dedicated to the promotion of necessary measures in order to combat the social inequalities. And regarding the specific objectives was to establish the SWOT analysis and the elaboration of strategic plans in local profile, based on clusters. The rural space analysis in the South-West region was made at the level of local administrative units, the lowest local level from which is collected and then published statistical information. Using of this local level is a prerequisite for obtaining positive results with a high fidelity degree.

  12. Modelling of Wave Attenuation Induced by Multi-Purpose Floating Structures

    DEFF Research Database (Denmark)

    Stratigaki, Vasiliki; Troch, Peter; Stallard, Tim;

    2014-01-01

    , polychromatic, long- and short-crested irregular waves), WEC response and modification of the wave field have been measured to provide data for the understanding of WEC farm interactions and for the evaluation of farm interaction numerical models. A first extensive wave farm database is established......Experiments have been performed in the Shallow Water Wave Basin of DHI (Hørsholm, Denmark) within the EU FP7 Hydralab Programme, on large farms of up to 25 heaving point absorber type Wave Energy Converters (WECs). For a range of geometric lay-out configurations and wave conditions (regular....... The experimental arrangement and the obtained database are presented, as well as results for wave height attenuation downwave of the farms. For long-crested irregular waves, up to 18.1 % and 20.8 % reduction in significant wave height is observed downwave of the 5x5-WEC rectilinear and staggered farm, respectively...

  13. STRATEGIC MODEL FOR ATTENUATING RURAL INEQUITIES IN SOUTH-MUNTENIA REGION

    Directory of Open Access Journals (Sweden)

    CRISTINA BÂLDAN

    2011-01-01

    Full Text Available In carrying out the paper: “Strategic model for attenuating rural inequities in South-Muntenia Region”, I had like primary goals the accomplishment of two kinds of objectives: general objectives and specific objectives. For the general objectives, I followed: developing the approach theoretical mode for combating rural inequities; the development of strategic plans for approaching the rural inequities combat and identifying strategic socio-economic measures dedicated for promoting necessary measures for combating social inequities. And the specific objectives had like goals the SWOT analysis and the development of strategic plans in local profile, based on clusters. The analysis of rural area in South-Muntenia Region has been made at the level of local administrative-territorial units, the smallest territorial level from which is collecting and after the statistic information is published. Utilizing this kind of territorial level is a positive premise for obtaining results with a high accurate degree.

  14. Different atmospheric effects causing FSO link attenuation: experimental results and modelling in Czech Republic

    Science.gov (United States)

    Fiser, Ondrej; Brazda, Vladimir; Wilfert, Otakar

    2015-10-01

    The four year FSO link attenuation measurement concurrently with most important meteorological parameters was performed at our mountain observatory Milesovka. In this contribution we summarize and classify different atmospheric phenomena after the FSO link attenuation quantity. For all particular phenomena the CD curves, typical events and simple dependences on relevant atmospheric parameter(s) are presented. We consider the following phenomena (approximate specific attenuation in dB/km in brackets): 1. Fog and cloud (hundreds dB/km) 2. Rain and snow (tens dB/km) 3. Atmospheric turbulence (unit dB) 4. Clear air attenuation due to water vapour (unit dB or less)

  15. Measuring and Modeling of the Dielectric Properties and Attenuation of Vegetation

    Science.gov (United States)

    Ulaby, F. T.

    1984-01-01

    The dielectric properties of vegetation material--primarily agricultural plants--as a function of moisture content and microwave frequency was measured and used to develop dielectric mixing models for the vegetation-water mixture. A model for the loss factor of a vegetation canopy was also developed. During the first phase of this investigation, three waveguide transmission systems covering from 1 to 2-GHz, from 3.5 to 6.5-GHz, and from 7.5 to 8.5-GHz bands were constructed and calibrated. By measuring the magnitude and phase of the field transmission coefficient of a given sample, it was possible to calculate the real and imaginary parts of the complex dielectric constant of the sample. Measurements were made for numerous samples of leaves and stalks of wheat and corn, and for wheat heads. Also, dielectric measurements were made of the liquid included in the vegetation material after extraction by mechanical means. The propagation loss is more than an order of magnitude greater than had previously been assumed. Various types of dielectric mixing models were investigated in terms of the available data, and a propagation model was developed and evaluated against direct canopy attenuation measurements. The canopy measurements were made by transmitting a signal from a radar antenna mounted atop a truck-mounted boom, and using a small antenna mounted on a rail beneath the canopy to receive it.

  16. Marine Mammal Brucella Reference Strains Are Attenuated in a BALB/c Mouse Model.

    Science.gov (United States)

    Nymo, Ingebjørg H; Arias, Maykel A; Pardo, Julián; Álvarez, María Pilar; Alcaraz, Ana; Godfroid, Jacques; Jiménez de Bagüés, María Pilar

    2016-01-01

    Brucellosis is a zoonosis of worldwide distribution with numerous animal host species. Since the novel isolation of Brucella spp. from marine mammals in 1994 the bacteria have been isolated from various marine mammal hosts. The marine mammal reference strains Brucella pinnipedialis 12890 (harbour seal, Phoca vitulina) and Brucella ceti 12891 (harbour porpoise, Phocoena phocoena) were included in genus Brucella in 2007, however, their pathogenicity in the mouse model is pending. Herein this is evaluated in BALB/c mice with Brucella suis 1330 as a control. Both marine mammal strains were attenuated, however, B. ceti was present at higher levels than B. pinnipedialis in blood, spleen and liver throughout the infection, in addition B. suis and B. ceti were isolated from brains and faeces at times with high levels of bacteraemia. In B. suis-infected mice serum cytokines peaked at day 7. In B. pinnipedialis-infected mice, levels were similar, but peaked predominantly at day 3 and an earlier peak in spleen weight likewise implied an earlier response. The inflammatory response induced pathology in the spleen and liver. In B. ceti-infected mice, most serum cytokine levels were comparable to those in uninfected mice, consistent with a limited inflammatory response, which also was indicated by restricted spleen and liver pathology. Specific immune responses against all three strains were detected in vitro after stimulation of splenocytes from infected mice with the homologous heat-killed brucellae. Antibody responses in vivo were also induced by the three brucellae. The immunological pattern of B. ceti in combination with persistence in organs and limited pathology has heretofore not been described for other brucellae. These two marine mammal wildtype strains show an attenuated pattern in BALB/c mice only previously described for Brucella neotomea.

  17. Levetiracetam attenuates rotenone-induced toxicity: A rat model of Parkinson's disease.

    Science.gov (United States)

    Erbaş, Oytun; Yılmaz, Mustafa; Taşkıran, Dilek

    2016-03-01

    Levetiracetam (LEV), a second-generation anti-epileptic drug, is used for treatment of both focal and generalized epilepsy. Growing body of evidence suggests that LEV may have neuroprotective effects. The present study was undertaken to investigate the neuroprotective effects of LEV on rotenone-induced Parkinson's disease (PD) in rats. Twenty-four adult Sprague-Dawley rats were infused with rotenone (3 μg/μl in DMSO) or vehicle (1 μl DMSO) into the left substantia nigra pars compacta (SNc) under stereotaxic surgery. PD model was assessed by rotational test ten days after drug infusion. The valid PD rats were randomly distributed into two groups; Group 1 (n=8) and Group 2 (n=8) were administered saline (1 ml/kg/day, i.p.) and LEV (600 mg/kg/day, i.p.) through 21 days, respectively. The effects of LEV treatment were evaluated by behavioral (rotation score), biochemical (brain homovalinic acid level and oxidant/antioxidant status) and immunohistochemical (tyrosine hydroxylase) parameters. Apomorphine-induced rotations in PD rats were significantly suppressed by LEV treatment. While unilateral rotenone lesion induced a dramatic loss of dopaminergic neurons both in the striatum and SNc, LEV treatment significantly attenuated the degenerative changes in dopaminergic neurons. Furthermore, LEV significantly decreased lipid peroxide levels, a marker of lipid peroxidation, and induced glutathione levels, catalase and superoxide dismutase activity in PD rats compared with saline group. We conclude that LEV may have beneficial effects on dopaminergic neurons against rotenone-induced injury. The underlying mechanism may be associated with the attenuation of oxidative stress. PMID:26896611

  18. Marine Mammal Brucella Reference Strains Are Attenuated in a BALB/c Mouse Model

    Science.gov (United States)

    Nymo, Ingebjørg H.; Arias, Maykel A.; Pardo, Julián; Álvarez, María Pilar; Alcaraz, Ana; Godfroid, Jacques; Jiménez de Bagüés, María Pilar

    2016-01-01

    Brucellosis is a zoonosis of worldwide distribution with numerous animal host species. Since the novel isolation of Brucella spp. from marine mammals in 1994 the bacteria have been isolated from various marine mammal hosts. The marine mammal reference strains Brucella pinnipedialis 12890 (harbour seal, Phoca vitulina) and Brucella ceti 12891 (harbour porpoise, Phocoena phocoena) were included in genus Brucella in 2007, however, their pathogenicity in the mouse model is pending. Herein this is evaluated in BALB/c mice with Brucella suis 1330 as a control. Both marine mammal strains were attenuated, however, B. ceti was present at higher levels than B. pinnipedialis in blood, spleen and liver throughout the infection, in addition B. suis and B. ceti were isolated from brains and faeces at times with high levels of bacteraemia. In B. suis-infected mice serum cytokines peaked at day 7. In B. pinnipedialis-infected mice, levels were similar, but peaked predominantly at day 3 and an earlier peak in spleen weight likewise implied an earlier response. The inflammatory response induced pathology in the spleen and liver. In B. ceti-infected mice, most serum cytokine levels were comparable to those in uninfected mice, consistent with a limited inflammatory response, which also was indicated by restricted spleen and liver pathology. Specific immune responses against all three strains were detected in vitro after stimulation of splenocytes from infected mice with the homologous heat-killed brucellae. Antibody responses in vivo were also induced by the three brucellae. The immunological pattern of B. ceti in combination with persistence in organs and limited pathology has heretofore not been described for other brucellae. These two marine mammal wildtype strains show an attenuated pattern in BALB/c mice only previously described for Brucella neotomea. PMID:26959235

  19. Screening of Mycobacterium avium subsp. paratuberculosis Mutants for Attenuation in a Bovine Monocyte-Derived Macrophage Model

    Directory of Open Access Journals (Sweden)

    Elise A Lamont

    2014-06-01

    Full Text Available Vaccination remains a major tool for prevention and progression of Johne’s disease, a chronic enteritis of ruminants worldwide. Currently there is only one licensed vaccine within the United States and two vaccines licensed internationally against Johne’s disease. All licensed vaccines reduce fecal shedding of Mycobacterium avium subsp. paratuberculosis (MAP and delay disease progression. However, there are no available vaccines that prevent disease onset. A joint effort by the Johne’s Disease Integrated Program (JDIP, a USDA-funded consortium, and USDA- APHIS/VS sought to identify transposon insertion mutant strains as vaccine candidates in part of a three phase study. The focus of the Phase I study was to evaluate MAP mutant attenuation in a well-defined in vitro bovine monocyte-derived macrophage (MDM model. Attenuation was determined by colony forming unit (CFUs counts and slope estimates. Based on CFU counts alone, the MDM model did not identify any mutant that significantly differed from the wild-type control, MAP K-10. Slope estimates using mixed models approach identified six mutants as being attenuated. These were enrolled in protection studies involving murine and baby goat vaccination-challenge models. MDM based approach identified trends in attenuation but this did not correlate with protection in a natural host model. These results suggest the need for alternative strategies for Johne’s disease vaccine candidate screening and evaluation.

  20. Laboratory model study of the effect of aeration on axial velocity attenuation of turbulent jet flows in plunge pool

    Institute of Scientific and Technical Information of China (English)

    邓军; 张法星; 田忠; 许唯临; 刘斌; 卫望汝

    2015-01-01

    In the laboratory model experiment, the velocities of the jet flow along the axis are measured, using the CQY−Z8a velocity-meter. The velocity attenuations of the jet flow along the axis under different conditions are studied. The effects of the aeration concentration, the initial jet velocity at the entry and the thickness of the jet flow on the velocity attenuation of the jet flow are analyzed. It is seen that the velocity attenuation of the jet flow along the axis sees a regular variation. It is demonstrated by the test results that under the experimental conditions, the velocity along the axis decreases linearly. The higher the air concentration is, the faster the velocity will be decayed. The absolute value of the slopeK increases with the rise of the air concentration. The relationship can be defined as=a+bKACK. The coefficientA is 0.03 under the experimental conditions. With the low air concentration of the jet flow, the thinner the jet flow is, the faster the velocity will be decayed. With the increase of the air concentra- tion, the influence of the thickness of the jet flow on the velocity attenuation is reduced. When the air concentration is increased to a certain value, the thickness of the jet flow may not have any influence on the velocity attenuation. The initial jet velocity itself at the entry has no influence on the variation of the velocity attenuation as the curves of the velocity attenuation at different velocities at the entry are practically parallel, even coinciding one with another. Therefore, improving the air concentration of the jet flow and disper- sing the jet flow in the plunge pool could reduce the influence of the jet flow on the scour.

  1. Brazilian red propolis attenuates hypertension and renal damage in 5/6 renal ablation model.

    Directory of Open Access Journals (Sweden)

    Flávio Teles

    Full Text Available The pathogenic role of inflammation and oxidative stress in chronic kidney disease (CKD is well known. Anti-inflammatories and antioxidant drugs has demonstrated significant renoprotection in experimental nephropathies. Moreover, the inclusion of natural antioxidants derived from food and herbal extracts (such as polyphenols, curcumin and lycopene as an adjuvant therapy for slowing CKD progression has been largely tested. Brazilian propolis is a honeybee product, whose anti-inflammatory, antimicrobial and antioxidant effects have been widely shown in models of sepsis, cancer, skin irritation and liver fibrosis. Furthermore, previous studies demonstrated that this compound promotes vasodilation and reduces hypertension. However, potential renoprotective effects of propolis in CKD have never been investigated. The aim of this study was to evaluate the effects of a subtype of Brazilian propolis, the Red Propolis (RP, in the 5/6 renal ablation model (Nx. Adult male Wistar rats underwent Nx and were divided into untreated (Nx and RP-treated (Nx+RP groups, after 30 days of surgery; when rats already exhibited marked hypertension and proteinuria. Animals were observed for 90 days from the surgery day, when Nx+RP group showed significant reduction of hypertension, proteinuria, serum creatinine retention, glomerulosclerosis, renal macrophage infiltration and oxidative stress, compared to age-matched untreated Nx rats, which worsened progressively over time. In conclusion, RP treatment attenuated hypertension and structural renal damage in Nx model. Reduction of renal inflammation and oxidative stress could be a plausible mechanism to explain this renoprotection.

  2. Pitfalls in urinary stone identification using CT attenuation values: Are we getting the same information on different scanner models?

    Energy Technology Data Exchange (ETDEWEB)

    Grosjean, Romain, E-mail: r.grosjean@chu-nancy.fr [IADI Laboratory, INSERM-U947, Nancy-University, Allée du Morvan, 54500 Vandoeuvre-les-Nancy (France); Daudon, Michel, E-mail: michel.daudon@tnn.aphp.fr [IADI Laboratory, INSERM-U947, Nancy-University, Allée du Morvan, 54500 Vandoeuvre-les-Nancy (France); Chammas, Mario F., E-mail: mariochammas@usp.br [University of Sao Paulo – Division of Urology, Av. Dr. Enéas de Carvalho Aguiar, 255, 7" o Andar – s. 7123, São Paulo (Brazil); Claudon, Michel, E-mail: m.claudon@chu-nancy.fr [IADI Laboratory, INSERM-U947, Nancy-University, Allée du Morvan, 54500 Vandoeuvre-les-Nancy (France); Eschwege, Pascal, E-mail: peschwege@yahoo.com [Department of Urology, Brabois Hospital, University Hospital of Nancy, Allée du Morvan, 54511 Vandoeuvre-les-Nancy (France); Felblinger, Jacques, E-mail: j.felblinger@chu-nancy.fr [IADI Laboratory, INSERM-U947, Nancy-University, Allée du Morvan, 54500 Vandoeuvre-les-Nancy (France); Hubert, Jacques, E-mail: j.hubert@chu-nancy.fr [Department of Urology, Brabois Hospital, University Hospital of Nancy, Allée du Morvan, 54511 Vandoeuvre-les-Nancy (France)

    2013-08-15

    Introduction: Evaluate the capability of different Computed Tomography scanners to determine urinary stone compositions based on CT attenuation values and to evaluate potential differences between each model. Methods: 241 human urinary stones were obtained and their biochemical composition determined. Four different CT scanners (Siemens, Philips, GEMS and Toshiba) were evaluated. Mean CT-attenuation values and the standard deviation were recorded separately and compared with a t-paired test. Results: For all tested CT scanners, when the classification of the various types of stones was arranged according to the mean CT-attenuation values and to the confidence interval, large overlappings between stone types were highlighted. The t-paired test showed that most stone types could not be identified. Some types of stones presented mean CT attenuation values significantly different from one CT scanner to another. At 80 kV, the mean CT attenuation values obtained with the Toshiba Aquilion were significantly different from those obtained with the Siemens Sensation. On the other hand, mean values obtained with the Philips Brilliance were all significantly equal to those obtained with the Siemens Sensation and with the Toshiba Aquilion. At 120 kV mean CT attenuation values of uric acid, cystine and struvite stones obtained with the Philips model are significantly different from those obtained with the Siemens and the Toshiba but equal to those obtained with the GE 64. Conclusions: According to our study, there is a great variability when different brands and models of scanners are compared directly. Furthermore, the CT scan analysis and HU evaluation appears to gather insufficient information in order to characterize and identify the composition of renal stones.

  3. Role of wetlands in attenuation of storm surges using coastal circulation model (ADCIRC), Chesapeake Bay region

    Science.gov (United States)

    Deb, Mithun; Ferreira, Celso; Lawler, Seth

    2014-05-01

    The Chesapeake Bay, Virginia is subject to storm surge from extreme weather events nearly year-round; from tropical storms and hurricanes during the summer and fall, (e.g., hurricanes Isabel [2003] and Sandy [2012]), and from nor'easters during the winter (e.g., winter storms Nemo and Saturn [2013]). Coastal wetlands can deliver acute fortification against incoming hurricane storm surges. Coastal wetlands and vegetation shape the hydrodynamics of storm surge events by retaining water and slowing the propagation of storm surge, acting as a natural barrier to flooding. Consequently, a precise scheme to quantify the effect of wetlands on coastal surge levels was also prerequisite. Two wetland sites were chosen in the Chesapeake Bay region for detailed cataloging of vegetation characteristics, including: height, stem diameter, and density. A framework was developed combining these wetlands characterizations with numerical simulations. Storms surges were calculated using Coastal circulation model (ADCIRC) coupled to a wave model (SWAN) forced by an asymmetric hurricane vortex model using an unstructured mesh (comprised of 1.8 million nodes) under a High Performance Computing environment. The Hurricane Boundary Layer (HBL) model was used to compute wind and pressure fields for historical tropical storms and for all of the synthetic storms. Wetlands were characterized in the coupled numerical models by bathymetric and frictional resistance. Multiple model simulations were performed using historical hurricane data and hypothetical storms to compare the predicted storm surge inundation resulting from various levels of wetlands expansion or reduction. The results of these simulations demonstrate the efficacy of wetlands in storm surge attenuation and also the outcome will scientifically support planning of wetlands restoration projects with multi-objective benefits for society.

  4. Zn/Ga−DFO iron–chelating complex attenuates the inflammatory process in a mouse model of asthma

    Directory of Open Access Journals (Sweden)

    Haim Bibi

    2014-01-01

    Conclusion: In this mouse model of allergic asthma, Zn/Ga−DFO attenuated allergic airway inflammation. The beneficial effects of treatment were in accord with iron overload abatement in asthmatic lungs by Zn/Ga−DFO. The findings in both cellular and tissue levels supported the existence of a significant anti-inflammatory effect of Zn/Ga−DFO.

  5. Bifidobacterium lactis attenuates onset of inflammation in a murine model of colitis

    Institute of Scientific and Technical Information of China (English)

    David Philippe; Stéphanie Blum; Laurent Favre; Francis Foata; Oskar Adolfsson; Genevieve Perruisseau-Carrier; Karine Vidal; Gloria Reuteler; Johanna Dayer-Schneider; Christoph Mueller

    2011-01-01

    AIM: To assess the anti-inflammatory effect of the probiotic Bifidobacterium lactis (B. lactis ) in an adoptive transfer model of colitis. METHODS: Donor and recipient mice received either B. lactis or bacterial culture medium as control (deMan Rogosa Sharpe) in drinking water for one week prior to transfer of a mix of naive and regulatory T cells until sacrifice. RESULTS: All recipient mice developed signs of colonic inflammation, but a significant reduction of weight loss was observed in B. lactis -fed recipient mice compared to control mice. Moreover, a trend toward a diminution of mucosal thickness and attenuated epithelial damage was revealed. Colonic expression of pro-inflammatory and T cell markers was significantly reduced in B. lactis - fed recipient mice compared to controls. Concomitantly, forkhead box protein 3, a marker of regulatory T cells, was significantly up-regulated by B. lactis . CONCLUSION: Daily oral administration of B. lactis was able to reduce inflammatory and T cells mediators and to promote regulatory T cells specific markers in a mouse model of colitis.

  6. Calcitriol attenuates cardiac remodeling and dysfunction in a murine model of polycystic ovary syndrome.

    Science.gov (United States)

    Gao, Ling; Cao, Jia-Tian; Liang, Yan; Zhao, Yi-Chao; Lin, Xian-Hua; Li, Xiao-Cui; Tan, Ya-Jing; Li, Jing-Yi; Zhou, Cheng-Liang; Xu, Hai-Yan; Sheng, Jian-Zhong; Huang, He-Feng

    2016-05-01

    Polycystic ovary syndrome (PCOS) is a complex reproductive and metabolic disorder affecting 10 % of reproductive-aged women, and is well associated with an increased prevalence of cardiovascular risk factors. However, there are few data concerning the direct association of PCOS with cardiac pathologies. The present study aims to investigate the changes in cardiac structure, function, and cardiomyocyte survival in a PCOS model, and explore the possible effect of calcitriol administration on these changes. PCOS was induced in C57BL/6J female mice by chronic dihydrotestosterone administration, as evidenced by irregular estrous cycles, obesity and dyslipidemia. PCOS mice progressively developed cardiac abnormalities including cardiac hypertrophy, interstitial fibrosis, myocardial apoptosis, and cardiac dysfunction. Conversely, concomitant administration of calcitriol significantly attenuated cardiac remodeling and cardiomyocyte apoptosis, and improved cardiac function. Molecular analysis revealed that the beneficial effect of calcitriol was associated with normalized autophagy function by increasing phosphorylation levels of AMP-activated protein kinase and inhibiting phosphorylation levels of mammalian target of rapamycin complex. Our findings provide the first evidence for the presence of cardiac remodeling in a PCOS model, and vitamin D supplementation may be a potential therapeutic strategy for the prevention and treatment of PCOS-related cardiac remodeling.

  7. Abietic acid attenuates allergic airway inflammation in a mouse allergic asthma model.

    Science.gov (United States)

    Gao, Yi; Zhaoyu, Liu; Xiangming, Fang; Chunyi, Lin; Jiayu, Pan; Lu, Shen; Jitao, Chen; Liangcai, Chen; Jifang, Liu

    2016-09-01

    Abietic acid (AA), one of the terpenoids isolated from Pimenta racemosa var. grissea, has been reported to have anti-inflammatory and immunomodulatory effects. However, the anti-allergic effects of AA remain unclear. The aim of this study was to investigate the anti-allergic effects of AA in an ovalbumin (OVA)-induced asthma murine model. The model of mouse asthma was established by induction of OVA. AA (10, 20, 40mg/kg) was administered by oral gavage 1h after the OVA treatment on days 21 to 23. At 24h after the last challenge, bronchoalveolar lavage fluid (BALF) and lung tissues were collected to assess pathological changes, cytokines production, and NF-κB expression. The results showed that AA attenuated lung histopathologic changes, inflammatory cells infiltration, and bronchial hyper-responsiveness. AA also inhibited OVA-induced the nitric oxide (NO), IL-4, IL-5, IL-13, and OVA-specific IgE production, as well as NF-κB activation. In conclusion, the current study demonstrated that AA exhibited protective effects against OVA-induced allergic asthma in mice and the possible mechanism was involved in inhibiting NF-κB activation. PMID:27318791

  8. Time-domain simulation of constitutive relations for nonlinear acoustics including relaxation for frequency power law attenuation media modeling

    Science.gov (United States)

    Jiménez, Noé; Camarena, Francisco; Redondo, Javier; Sánchez-Morcillo, Víctor; Konofagou, Elisa E.

    2015-10-01

    We report a numerical method for solving the constitutive relations of nonlinear acoustics, where multiple relaxation processes are included in a generalized formulation that allows the time-domain numerical solution by an explicit finite differences scheme. Thus, the proposed physical model overcomes the limitations of the one-way Khokhlov-Zabolotskaya-Kuznetsov (KZK) type models and, due to the Lagrangian density is implicitly included in the calculation, the proposed method also overcomes the limitations of Westervelt equation in complex configurations for medical ultrasound. In order to model frequency power law attenuation and dispersion, such as observed in biological media, the relaxation parameters are fitted to both exact frequency power law attenuation/dispersion media and also empirically measured attenuation of a variety of tissues that does not fit an exact power law. Finally, a computational technique based on artificial relaxation is included to correct the non-negligible numerical dispersion of the finite difference scheme, and, on the other hand, improve stability trough artificial attenuation when shock waves are present. This technique avoids the use of high-order finite-differences schemes leading to fast calculations. The present algorithm is especially suited for practical configuration where spatial discontinuities are present in the domain (e.g. axisymmetric domains or zero normal velocity boundary conditions in general). The accuracy of the method is discussed by comparing the proposed simulation solutions to one dimensional analytical and k-space numerical solutions.

  9. Epistemic uncertainty and limitations of the κ0 model for near-surface attenuation at hard rock sites

    Science.gov (United States)

    Edwards, Benjamin; Ktenidou, Olga-Joan; Cotton, Fabrice; Abrahamson, Norman; Van Houtte, Chris; Fäh, Donat

    2015-09-01

    The determination of near-surface attenuation for hard rock sites is an important issue in a wide range of seismological applications, particularly seismic hazard analysis. In this article we choose six hard to very-hard rock sites (Vs30 1030-3000 m s-1) and apply a range of analysis methods to measure the observed attenuation at distance based on a simple exponential decay model with whole-path attenuation operator κr. The κr values are subsequently decoupled from path attenuation (Q) so as to obtain estimates of near-surface attenuation (κ0). Five methods are employed to measure κr which can be split into two groups: broad-band methods and high-frequency methods. Each of the applied methods has advantages and disadvantages, which are explored and discussed through the comparison of results from common data sets. In our first step we examine the variability of the individual measured κr values. Some variation between methods is expected due to simplifications of source, path, and site effects. However, we find that significant differences arise between attenuation measured on individual recordings, depending on the method employed or the modelling decisions made during a particular approach. Some of the differences can be explained through site amplification effects: although usually weak at rock sites, amplification may still lead to bias of the measured κr due to the chosen fitting frequency bandwidth, which often varies between methods. At some sites the observed high-frequency spectral shape was clearly different to the typical κr attenuation model, with curved or bi-linear rather than linear decay at high frequencies. In addition to amplification effects this could be related to frequency-dependent attenuation effects [e.g. Q( f )]: since the κr model is implicitly frequency independent, κr will in this case be dependent on the selected analysis bandwidth. In our second step, using the whole-path κr data sets from the five approaches, we investigate

  10. Epistemic Uncertainty and Limitations of the Kappa0 model for Near-surface Attenuation at Hard Rock Sites

    Science.gov (United States)

    Edwards, Benjamin

    2016-04-01

    The determination of near-surface attenuation for hard rock sites is an important issue in a wide range of seismological applications, particularly seismic hazard analysis. In this article we choose six hard to very-hard rock sites (Vs30 1030 to 3000 m/s) and apply a range of analysis methods to measure the observed attenuation at distance based on a simple exponential decay model with whole-path attenuation operator κ. The κ values are subsequently decoupled from path attenuation (Q) so as to obtain estimates of near-surface attenuation (κ0). Five methods are employed to measure κ which can be split into two groups: broadband methods and high-frequency methods. Each of the applied methods has advantages and disadvantages, which are explored and discussed through the comparison of results from common datasets. In our first step we examine the variability of the individual measured κ values. Some variation between methods is expected due to simplifications of source, path, and site effects. However, we find that significant differences arise between attenuation measured on individual recordings, depending on the method employed or the modelling decisions made during a particular approach. Some of the differences can be explained through site amplification effects: although usually weak at rock sites, amplification may still lead to bias of the measured κ due to the chosen fitting frequency bandwidth, which often varies between methods. At some sites the observed high-frequency spectral shape was clearly different to the typical κ attenuation model, with curved or bi-linear rather than linear decay at high frequencies. In addition to amplification effects this could be related to frequency-dependent attenuation effects (e.g., Q(f)): since the κ model is implicitly frequency independent, κ will in this case be dependent on the selected analysis bandwidth. In our second step, using the whole-path κ datasets from the five approaches, we investigate the

  11. Physical modeling and analysis of P-wave attenuation anisotropy in transversely isotropic media

    Digital Repository Service at National Institute of Oceanography (India)

    Zhu, Y.; Tsvankin, I.; Dewangan, P.; Van Wijk, K.

    phase attenuation coefficient A governed by the Thomsen- style attenuation-anisotropy parameters H9280Q and H9254Q. Whereas the symmetry axis of the angle-dependent coefficient Aprac- tically coincides with that of the velocity function, the magni- tude... and Tsvankin H208492004, 2006H20850 introduced Thomsen-style attenuation parameters H9280Q, H9254Q, and H9253Q de- rived from the Q-matrix for transversely isotropic H20849TIH20850 media and used the new notation to obtain simple approximations for the angle...

  12. Ferric Carboxymaltose-Mediated Attenuation of Doxorubicin-Induced Cardiotoxicity in an Iron Deficiency Rat Model

    Directory of Open Access Journals (Sweden)

    Jorge Eduardo Toblli

    2014-01-01

    Full Text Available Since anthracycline-induced cardiotoxicity (AIC, a complication of anthracycline-based chemotherapies, is thought to involve iron, concerns exist about using iron for anaemia treatment in anthracycline-receiving cancer patients. This study evaluated how intravenous ferric carboxymaltose (FCM modulates the influence of iron deficiency anaemia (IDA and doxorubicin (3–5 mg per kg body weight [BW] on oxidative/nitrosative stress, inflammation, and cardiorenal function in spontaneously hypertensive stroke-prone (SHR-SP rats. FCM was given as repeated small or single total dose (15 mg iron per kg BW, either concurrent with or three days after doxorubicin. IDA (after dietary iron restriction induced cardiac and renal oxidative stress (markers included malondialdehyde, catalase, Cu,Zn-superoxide dismutase, and glutathione peroxidase, nitrosative stress (inducible nitric oxide synthase and nitrotyrosine, inflammation (tumour necrosis factor-alpha and interleukin-6, and functional/morphological abnormalities (left ventricle end-diastolic and end-systolic diameter, fractional shortening, density of cardiomyocytes and capillaries, caveolin-1 expression, creatinine clearance, and urine neutrophil gelatinase-associated lipocalin that were aggravated by doxorubicin. Notably, iron treatment with FCM did not exacerbate but attenuated the cardiorenal effects of IDA and doxorubicin independent of the iron dosing regimen. The results of this model suggest that intravenous FCM can be used concomitantly with an anthracycline-based chemotherapy without increasing signs of AIC.

  13. Activation of farnesoid X receptor attenuates hepatic injury in a murine model of alcoholic liver disease.

    Science.gov (United States)

    Wu, Weibin; Zhu, Bo; Peng, Xiaomin; Zhou, Meiling; Jia, Dongwei; Gu, Jianxin

    2014-01-01

    Alcoholic liver disease (ALD) is a common cause of advanced liver disease, and considered as a major risk factor of morbidity and mortality worldwide. Hepatic cholestasis is a pathophysiological feature observed in all stages of ALD. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily, and plays an essential role in the regulation of bile acid, lipid and glucose homeostasis. However, the role of FXR in the pathogenesis and progression of ALD remains largely unknown. Mice were fed Lieber-DeCarli ethanol diet or an isocaloric control diet. We used a specific agonist of FXR WAY-362450 to study the effect of pharmacological activation of FXR in alcoholic liver disease. In this study, we demonstrated that FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR by specific agonist WAY-362450 protected mice from the development of ALD. We also found that WAY-362450 treatment rescued FXR activity, suppressed ethanol-induced Cyp2e1 up-regulation and attenuated oxidative stress in liver. Our results highlight a key role of FXR in the modulation of ALD development, and propose specific FXR agonists for the treatment of ALD patients. PMID:24269813

  14. Inhibition of classical complement activation attenuates liver ischaemia and reperfusion injury in a rat model.

    Science.gov (United States)

    Heijnen, B H M; Straatsburg, I H; Padilla, N D; Van Mierlo, G J; Hack, C E; Van Gulik, T M

    2006-01-01

    Activation of the complement system contributes to the pathogenesis of ischaemia/reperfusion (I/R) injury. We evaluated inhibition of the classical pathway of complement using C1-inhibitor (C1-inh) in a model of 70% partial liver I/R injury in male Wistar rats (n = 35). C1-inh was administered at 100, 200 or 400 IU/kg bodyweight, 5 min before 60 min ischaemia (pre-I) or 5 min before 24 h reperfusion (end-I). One hundred IU/kg bodyweight significantly reduced the increase of plasma levels of activated C4 as compared to albumin-treated control rats and attenuated the increase of alanine aminotransferase (ALT). These effects were not better with higher doses of C1-inh. Administration of C1-inh pre-I resulted in lower ALT levels and higher bile secretion after 24 h of reperfusion than administration at end-I. Immunohistochemical assessment indicated that activated C3, the membrane attack complex C5b9 and C-reactive protein (CRP) colocalized in hepatocytes within midzonal areas, suggesting CRP is a mediator of I/R-induced, classical complement activation in rats. Pre-ischaemic administration of C1-inh is an effective pharmacological intervention to protect against liver I/R injury.

  15. Finite-difference numerical modelling of gravitoacoustic wave propagation in a windy and attenuating atmosphere

    Science.gov (United States)

    Brissaud, Quentin; Martin, Roland; Garcia, Raphaël F.; Komatitsch, Dimitri

    2016-07-01

    Acoustic and gravity waves propagating in planetary atmospheres have been studied intensively as markers of specific phenomena such as tectonic events or explosions or as contributors to atmosphere dynamics. To get a better understanding of the physics behind these dynamic processes, both acoustic and gravity waves propagation should be modelled in a 3-D attenuating and windy atmosphere extending from the ground to the upper thermosphere. Thus, in order to provide an efficient numerical tool at the regional or global scale, we introduce a finite difference in the time domain (FDTD) approach that relies on the linearized compressible Navier-Stokes equations with a background flow (wind). One significant benefit of such a method is its versatility because it handles both acoustic and gravity waves in the same simulation, which enables one to observe interactions between them. Simulations can be performed for 2-D or 3-D realistic cases such as tsunamis in a full MSISE-00 atmosphere or gravity-wave generation by atmospheric explosions. We validate the computations by comparing them to analytical solutions based on dispersion relations in specific benchmark cases: an atmospheric explosion, and a ground displacement forcing.

  16. Animal models of psychopathology: the establishment, maintenance, attenuation, and persistence of head-banging by pigeons.

    Science.gov (United States)

    Layng, T V; Andronis, P T; Goldiamond, I

    1999-03-01

    Investigators of animal models of psychopathology have typically introduced experimental conditions so that an animal's behavior progressively deviates from a baseline of routine laboratory behavior toward a pattern which resembles human psychopathological behavior in some form of S, then R relation. The present experiments report consequential contingency procedures for bringing head-to-wall head-banging by an animal under experimental control and analysis. The first two experiments examined the establishment and maintenance by reinforcement of head-banging by pigeons. The final two experiments examined the occurrence of head-banging, under conditions of extinction and limited reinforcement, when an alternative behavior, i.e., key-pecking, was reinforced under a variety of reinforcement schedules. Extinguished and infrequently reinforced head-banging was found to recur under a variety of conditions including the reinforcement of the more "normal" alternative behavior. To the extent that human patterns are governed by similar functional relations, the data may be of relevance in the analysis of the maintenance, attenuation, and recurrence of human patterns designated as pathological. Further, the permanent elimination of a disturbing pattern may be difficult, and the recurrence of a disturbing pattern might properly be considered a likely and "normal" outcome of basic behavioral processes. PMID:10365865

  17. Propensity of Withania somnifera to Attenuate Behavioural, Biochemical, and Histological Alterations in Experimental Model of Stroke.

    Science.gov (United States)

    Sood, Abhilasha; Kumar, Aditya; Dhawan, Devinder K; Sandhir, Rajat

    2016-10-01

    The present study was designed to evaluate the beneficial effects of Withania somnifera (WS) pre-supplementation on middle cerebral artery occlusion (MCAO) model of ischemic stroke. Ischemic stroke was induced in the rats by inserting intraluminal suture for 90 min, followed by reperfusion injury for 24 h. The animals were assessed for locomotor functions (by neurological deficit scores, narrow beam walk and rotarod test), cognitive and anxiety-like behavioural functions (by morris water maze and elevated plus maze test). MCAO animals showed significant impairment in locomotor and cognitive functions. Neurobehavioural changes were accompanied by decreased acetylcholinesterase activity, increased oxidative stress in terms of enhanced lipid peroxidation and lowered thiol levels in the MCAO animals. In addition, MCAO animals had cerebral infarcts and the presence of pycnotic nuclei. Single-photon emission computerized tomography (SPECT) of MCAO animals revealed a cerebral infarct as a hypoactive area. On the other hand, pre-supplementation with WS (300 mg/kg body weight) for 30 days to MCAO animals was effective in restoring the acetylcholinesterase activity, lipid peroxidation, thiols and attenuated MCAO induced behavioural deficits. WS significantly reduced the cerebral infarct volume and ameliorated histopathological alterations. Improved blood flow was observed in the SPECT images from the brain regions of ischemic rats pre-treated with WS. The results of the study showed a protective effect of WS supplementation in ischemic stroke and are suggestive of its potential application in stroke management. PMID:26718711

  18. Simvastatin delivery via inhalation attenuates airway inflammation in a murine model of asthma.

    Science.gov (United States)

    Xu, Lan; Dong, Xing-wei; Shen, Liang-liang; Li, Fen-fen; Jiang, Jun-xia; Cao, Rui; Yao, Hong-yi; Shen, Hui-juan; Sun, Yun; Xie, Qiang-min

    2012-04-01

    The dose-response of the pleiotropic effects of statins on airway inflammation has not yet been established and may differ from that of their cholesterol-lowering effects. High oral doses of statins may have adverse effects, and it may be possible to overcome the side effects and low clinical efficacy by administering statins via inhalation. In this study, we hypothesize that simvastatin is a potential anti-inflammatory drug with biological and pharmacokinetic properties suitable for delivery by the inhaled route. Mice were immunized with ovalbumin (OVA) and then challenged with aerosol OVA. Simvastatin was locally delivered by inhalation (i.h.) and intratracheal injection (i.t.) or systematically delivered by intraperitoneal injection (i.p.) and gavage (i.g.) during the OVA challenge. In a mouse model of asthma, i.h. simvastatin significantly and dose-dependently attenuated airway inflammation, remodeling and hyperresponsiveness in a RhoA-dependent pathway. Upon comparing the pharmacodynamics, i.h. simvastatin had a more potent effect than that of i.g. and i.p. simvastatin, and the i.h. or i.t. delivery routes led to a higher drug concentration in local lung tissue and a lower drug concentration in the plasma than that obtained by the i.g. These results suggest that simvastatin is a potential anti-inflammatory drug for airway inflammatory diseases with properties suitable for delivery by inhalation, which will probably reduce the side effects and increase clinical efficacy. PMID:22326624

  19. Fasudil attenuates aggregation of α-synuclein in models of Parkinson's disease.

    Science.gov (United States)

    Tatenhorst, Lars; Eckermann, Katrin; Dambeck, Vivian; Fonseca-Ornelas, Luis; Walle, Hagen; Lopes da Fonseca, Tomás; Koch, Jan C; Becker, Stefan; Tönges, Lars; Bähr, Mathias; Outeiro, Tiago F; Zweckstetter, Markus; Lingor, Paul

    2016-01-01

    Parkinson's disease (PD) is the most common neurodegenerative movement disorder, yet disease-modifying treatments do not currently exist. Rho-associated protein kinase (ROCK) was recently described as a novel neuroprotective target in PD. Since alpha-synuclein (α-Syn) aggregation is a major hallmark in the pathogenesis of PD, we aimed to evaluate the anti-aggregative potential of pharmacological ROCK inhibition using the isoquinoline derivative Fasudil, a small molecule inhibitor already approved for clinical use in humans. Fasudil treatment significantly reduced α-Syn aggregation in vitro in a H4 cell culture model as well as in a cell-free assay. Nuclear magnetic resonance spectroscopy analysis revealed a direct binding of Fasudil to tyrosine residues Y133 and Y136 in the C-terminal region of α-Syn. Importantly, this binding was shown to be biologically relevant using site-directed mutagenesis of these residues in the cell culture model. Furthermore, we evaluated the impact of long-term Fasudil treatment on α-Syn pathology in vivo in a transgenic mouse model overexpressing human α-Syn bearing the A53T mutation (α-Syn(A53T) mice). Fasudil treatment improved motor and cognitive functions in α-Syn(A53T) mice as determined by Catwalk(TM) gait analysis and novel object recognition (NOR), without apparent side effects. Finally, immunohistochemical analysis revealed a significant reduction of α-Syn pathology in the midbrain of α-Syn(A53T) mice after Fasudil treatment. Our results demonstrate that Fasudil, next to its effects mediated by ROCK-inhibition, directly interacts with α-Syn and attenuates α-Syn pathology. This underscores the translational potential of Fasudil as a disease-modifying drug for the treatment of PD and other synucleinopathies. PMID:27101974

  20. Excessive lever pressing following post-training signal attenuation in rats: a possible animal model of obsessive compulsive disorder?

    Science.gov (United States)

    Joel, D; Avisar, A

    2001-08-27

    This study aimed at developing a rat model of obsessive compulsive disorder based on the hypothesis that a deficient response feedback mechanism underlies obsessions and compulsions. Rats were trained to lever press for food, whose delivery was signaled by the presentation of a compound stimulus (light+tone). Subsequently, the classical contingency between the stimulus and food was extinguished (signal attenuation). Experiment 1 showed that this manipulation resulted in increased lever pressing during a subsequent extinction test, which was highly correlated with an increase in the number of trials on which the rat did not attempt to collect the food reward. This behavioral pattern was not evident in an extinction test not preceded by signal attenuation (Experiment 2), suggesting that the latter is a crucial factor in the development of this behavioral pattern. Excessive lever pressing was attenuated by the selective serotonin re-uptake inhibitor, fluoxetine (10 mg/kg; Experiment 3), but not by the anxiolytic drug, diazepam (2 mg/kg; Experiment 4). Based on these results we propose that post-training signal attenuation may provide a rat model of obsessive compulsive disorder. PMID:11377731

  1. Asparagus racemosus attenuates anxiety-like behavior in experimental animal models.

    Science.gov (United States)

    Garabadu, Debapriya; Krishnamurthy, Sairam

    2014-05-01

    Asparagus racemosus Linn. (AR) is used worldwide as a medicinal plant. In the present study, the anxiolytic activity of standardized methanolic extract of root of AR (MAR) was evaluated in open-field test (OFT), hole-board, and elevated plus maze (EPM) tests. Rats received oral pretreatment of MAR in the doses of 50, 100, and 200 mg/kg daily for 7 days and then were evaluated for the anxiolytic activity in different animal models. Both MAR (100 and 200 mg/kg) and diazepam (1 mg/kg, p.o.) increased the grooming behavior, number of central squares crossed, and time spent in the central area during OFT. Further, MAR (100 and 200 mg/kg) increased the head-dip and head-dip/sniffing behavior, and decreased sniffing activity in hole-board test. Furthermore, MAR (100 and 200 mg/kg) increased the percentage entries and time spent to open arm in EPM test paradigm. The anxiolytic activity in the experimental models was similar to that of diazepam. MAR (100 and 200 mg/kg) enhanced the level of amygdalar serotonin and norepinephrine. It also increased the expression of 5-HT2A receptors in the amygdala. In another set of experiment, flumazenil attenuated the anxiolytic effect of minimum effective dose of MAR (100 mg/kg) in OFT, hole-board, and EPM tests, indicating GABAA-mediated mechanism. Moreover, the anxiolytic dose of MAR did not show sedative-like effect in OFT and EPM tests compared to diazepam (6 mg/kg, p.o.). Thus, the anxiolytic response of MAR may involve GABA and serotonergic mechanisms. These preclinical data show that AR can be a potential agent for treatment of anxiety disorders.

  2. Natural Attenuation model and degrading bacterial community of 1,1,1-Trichloroethane contaminant in Shallow Groundwater in Shanghai

    Directory of Open Access Journals (Sweden)

    Qiang eLu

    2015-08-01

    Full Text Available Natural attenuation is an effective and feasible technology for controlling groundwater contamination. This study investigated the potential effectiveness and mechanisms of natural attenuation of 1,1,1-trichloroethane (TCA contaminants in in Shallow Groundwater in Shanghai by using a column simulation experiment, reactive transport model, and 16S rRNA gene clone library. The results indicated that the majority of the contaminant mass was present at 2-6 m in depth, the contaminated area was approximately 1000 m2, and natural attenuation processes were occurring at the site. The effluent breakthrough curves from the column experiments demonstrated that the effectiveness of TCA natural attenuation in the groundwater accorded with the advection-dispersion-reaction equation. The kinetic parameter of adsorption and biotic dehydrochlorination of TCA was 0.068 m3/kg and 0.0045 d-1. The contamination plume was predicted to diminish and the maximum concentration of TCA decreased to 280 μg/L. The bacterial community in situ groundwater belonged to Trichococcus, Geobacteraceae, Geobacter, Mucilaginibacter and Arthrobacter.

  3. A Unified Statistical Rain-Attenuation Model for Communication Link Fade Predictions and Optimal Stochastic Fade Control Design Using a Location-Dependent Rain-Statistic Database

    Science.gov (United States)

    Manning, Robert M.

    1990-01-01

    A static and dynamic rain-attenuation model is presented which describes the statistics of attenuation on an arbitrarily specified satellite link for any location for which there are long-term rainfall statistics. The model may be used in the design of the optimal stochastic control algorithms to mitigate the effects of attenuation and maintain link reliability. A rain-statistics data base is compiled, which makes it possible to apply the model to any location in the continental U.S. with a resolution of 0-5 degrees in latitude and longitude. The model predictions are compared with experimental observations, showing good agreement.

  4. Ultrasound Attenuation in Biological Tissue Predicted by the Modified Doublet Mechanics Model

    Institute of Scientific and Technical Information of China (English)

    JIANG Xin; LIU Xiao-Zhou; WU Jun-Ru

    2009-01-01

    Experimental results have shown that in the megahertz frequency range the relationship between the acoustic attenuation coefficient in soft tissues and frequency is nearly linear. The classical continuum mechanics (CCM),which assumes that the material is uniform and continuous, fails to explain this relationship particularly in the high megahertz range. Doublet mechanics (DM) is a new elastic theory which takes the discrete nature of material into account. The current DM theory however does not consider the loss. We revise the doublet mechanics (DM)theory by including the loss term, and calculate the attenuation of a soft tissue as a function of frequency using the modified the DM theory (MDM). The MDM can now well explain the nearly linear relationship between the acoustic attenuation coefficient in soft tissues and frequency.

  5. Dixon sequence with superimposed model-based bone compartment provides highly accurate PET/MR attenuation correction of the brain

    OpenAIRE

    Koesters, Thomas; Friedman, Kent P.; Fenchel, Matthias; Zhan, Yiqiang; Hermosillo, Gerardo; Babb, James; Jelescu, Ileana O.; Faul, David; Boada, Fernando E.; Shepherd, Timothy M.

    2016-01-01

    Simultaneous PET/MR of the brain is a promising new technology for characterizing patients with suspected cognitive impairment or epilepsy. Unlike CT though, MR signal intensities do not provide a direct correlate to PET photon attenuation correction (AC) and inaccurate radiotracer standard uptake value (SUV) estimation could limit future PET/MR clinical applications. We tested a novel AC method that supplements standard Dixon-based tissue segmentation with a superimposed model-based bone com...

  6. Combination of Epinephrine with Esmolol Attenuates Post-Resuscitation Myocardial Dysfunction in a Porcine Model of Cardiac Arrest

    OpenAIRE

    Qian Zhang; Chunsheng Li

    2013-01-01

    BACKGROUND: Recent experimental and clinical studies have indicated that the β-adrenergic effect of epinephrine significantly increases the severity of post resuscitation myocardial dysfunction. The aim of the study was to investigate whether the short-acting β₁-selective adrenergic blocking agent, esmolol, would attenuate post resuscitation myocardial dysfunction in a porcine model of cardiac arrest. METHODS AND RESULTS: After 8 min of untreated ventricular fibrillation and 2 min of basic li...

  7. Modelling the attenuation in the ATHENA finite elements code for the ultrasonic testing of austenitic stainless steel welds.

    Science.gov (United States)

    Chassignole, B; Duwig, V; Ploix, M-A; Guy, P; El Guerjouma, R

    2009-12-01

    Multipass welds made in austenitic stainless steel, in the primary circuit of nuclear power plants with pressurized water reactors, are characterized by an anisotropic and heterogeneous structure that disturbs the ultrasonic propagation and makes ultrasonic non-destructive testing difficult. The ATHENA 2D finite element simulation code was developed to help understand the various physical phenomena at play. In this paper, we shall describe the attenuation model implemented in this code to give an account of wave scattering phenomenon through polycrystalline materials. This model is in particular based on the optimization of two tensors that characterize this material on the basis of experimental values of ultrasonic velocities attenuation coefficients. Three experimental configurations, two of which are representative of the industrial welds assessment case, are studied in view of validating the model through comparison with the simulation results. We shall thus provide a quantitative proof that taking into account the attenuation in the ATHENA code dramatically improves the results in terms of the amplitude of the echoes. The association of the code and detailed characterization of a weld's structure constitutes a remarkable breakthrough in the interpretation of the ultrasonic testing on this type of component.

  8. Edaravone attenuates ischemia-reperfusion injury by inhibiting oxidative stress in a canine lung transplantation model

    Institute of Scientific and Technical Information of China (English)

    XU Jin-zhi; SHEN Bao-zhong; LI Ye; ZHANG Tong; XU Wan-hai; LIU Xiao-wei; LU Hong-guang

    2008-01-01

    .Conclusions Edaravone attenuates IR-induced lung injury and preserves lung function by inhibiting oxidative stress and decreasing leukocyte extravasation in a canine lung transplantation model.

  9. Overexpression of dimethylarginine dimethylaminohydrolase 1 attenuates airway inflammation in a mouse model of asthma.

    Directory of Open Access Journals (Sweden)

    Kayla G Kinker

    Full Text Available Levels of asymmetric dimethylarginine (ADMA, an endogenous inhibitor of nitric oxide synthase, are increased in lung, sputum, exhaled breath condensate and plasma samples from asthma patients. ADMA is metabolized primarily by dimethylarginine dimethylaminohydrolase 1 (DDAH1 and DDAH2. We determined the effect of DDAH1 overexpression on development of allergic inflammation in a mouse model of asthma. The expression of DDAH1 and DDAH2 in mouse lungs was determined by RT-quantitative PCR (qPCR. ADMA levels in bronchoalveolar lavage fluid (BALF and serum samples were determined by mass spectrometry. Wild type and DDAH1-transgenic mice were intratracheally challenged with PBS or house dust mite (HDM. Airway inflammation was assessed by bronchoalveolar lavage (BAL total and differential cell counts. The levels of IgE and IgG1 in BALF and serum samples were determined by ELISA. Gene expression in lungs was determined by RNA-Seq and RT-qPCR. Our data showed that the expression of DDAH1 and DDAH2 was decreased in the lungs of mice following HDM exposure, which correlated with increased ADMA levels in BALF and serum. Transgenic overexpression of DDAH1 resulted in decreased BAL total cell and eosinophil numbers following HDM exposure. Total IgE levels in BALF and serum were decreased in HDM-exposed DDAH1-transgenic mice compared to HDM-exposed wild type mice. RNA-Seq results showed downregulation of genes in the inducible nitric oxide synthase (iNOS signaling pathway in PBS-treated DDAH1-transgenic mice versus PBS-treated wild type mice and downregulation of genes in IL-13/FOXA2 signaling pathway in HDM-treated DDAH1-transgenic mice versus HDM-treated wild type mice. Our findings suggest that decreased expression of DDAH1 and DDAH2 in the lungs may contribute to allergic asthma and overexpression of DDAH1 attenuates allergen-induced airway inflammation through modulation of Th2 responses.

  10. Erythronium japonicum attenuates histopathological lung abnormalities in a mouse model of ovalbumin-induced asthma.

    Science.gov (United States)

    Seo, Ji-Hye; Bang, Mi-Ae; Kim, Gyeyeop; Cho, Seung Sik; Park, Dae-Hun

    2016-05-01

    Asthma is a chronic lung condition that can induce mucus hypersecretion and pulmonary obstruction and may even cause death, particularly in children and older individuals. Erythronium japonicum (E. japonicum) is a traditional herb used in Korea and East Asian countries that has been found to exert free radical scavenging activity and anti-proliferative effects in human colorectal carcinoma cells. In the present study, we evaluated the anti-asthmatic effects of an extract of E. japonicum in a mouse model of ovalbumin (OVA)‑induced asthma. Female BALB/c mice were sensitized with an intraperitoneal injection of OVA and aluminum hydroxide hydrate on days 1 and 8 and then received the following treatments on days 21 to 25: i) control (no treatment), ii) sterilized tap water (given orally), iii) 1 mg/kg/day dexamethasone (administered orally), iv) 60 mg/kg/day E. japonicum extract, and v) 600 mg/kg/day E. japonicum extract. On the same days, all the mice except those in the control group were challenged 1 h later with nebulized 5% OVA for 30 min. We found that treatment with E. japonicum extract suppressed the OVA-induced increase in the number of white blood cells and decreased the IgE level in the bronchoalveolar lavage fluid samples obtained from the mice. Histopathological analysis of the lung tissues revealed that E. japonicum attenuated the asthma-related morphological changes in the mouse lung tissue, including the increased secretion of mucus in the bronchioles, eosinophil infiltration around the bronchioles and vessels, and goblet cell and epithelial cell hyperplasia. Immunohistochemical analysis revealed that treatment with E. japonicum extract suppressed the OVA-induced proliferation of T helper cells (CD4+) and B cells (CD19+) in the mouse lung tissue. Furthermore, treatment with E. japonicum extract modulated the expression of both T helper 2 cell-related factors [GATA binding protein 3 (GATA-3), tumor necrosis factor

  11. Model of counterparty risk with geometric attenuation and valuation of CDS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    To investigate the impact of microstructure interdependency of a counterparty explicitly, a geometric function is introduced in one firm's default intensity to reflect the attenuation behavior of the impact of its counterparty firm's default. The general joint distribution and marginal distributions of default times are derived by employing the change of measure. The fair premium of a vanilla CDS (credit default swap) is obtained in continuous and discrete contexts, respectively. The swap premium in a discr...

  12. A Generalized Lossy Transmission-Line Model for Tunable Graphene-Based Transmission Lines with Attenuation Phenomenon

    Science.gov (United States)

    Wu, Yongle; Qu, Meijun; Liu, Yuanan

    2016-08-01

    To investigate the frequency shift phenomenon by inserting graphene, a generalized lossy transmission-line model and the related electrical parameter-extraction theory are proposed in this paper. Three kinds of graphene-based transmission lines with attenuation phenomenon including microstrip line, double-side parallel strip line, and uniplanar coplanar waveguide are analyzed under the common conditions where different chemical potentials are loaded on graphene. The values of attenuation constant and phase constant, and the real and imaginary parts of the characteristic impedance of transmission lines are extracted to analyze in details. When the attenuation constant and the reactance part of the characteristic impedance are approximately equal to zero, this kind of transmission line has low or zero insertion loss. On the contrary, the transmission line is under the radiation mode with obvious insertion loss. The phase constant changes linearly under the transmission mode and can be varied with changing of chemical potentials which attributes to the property of frequency tunability. Furthermore, a bandwidth reconfigurable uniplanar coplanar waveguide power divider is simulated to demonstrate that this theory can be applied to the design of three-port devices. In summary, this work provides a strong potential approach and design theory to help design other kinds of terahertz and mid-infrared reconfigurable devices.

  13. A statistical rain attenuation prediction model with application to the advanced communication technology satellite project. Part 2: Theoretical development of a dynamic model and application to rain fade durations and tolerable control delays for fade countermeasures

    Science.gov (United States)

    Manning, Robert M.

    1987-01-01

    A dynamic rain attenuation prediction model is developed for use in obtaining the temporal characteristics, on time scales of minutes or hours, of satellite communication link availability. Analagous to the associated static rain attenuation model, which yields yearly attenuation predictions, this dynamic model is applicable at any location in the world that is characterized by the static rain attenuation statistics peculiar to the geometry of the satellite link and the rain statistics of the location. Such statistics are calculated by employing the formalism of Part I of this report. In fact, the dynamic model presented here is an extension of the static model and reduces to the static model in the appropriate limit. By assuming that rain attenuation is dynamically described by a first-order stochastic differential equation in time and that this random attenuation process is a Markov process, an expression for the associated transition probability is obtained by solving the related forward Kolmogorov equation. This transition probability is then used to obtain such temporal rain attenuation statistics as attenuation durations and allowable attenuation margins versus control system delay.

  14. Surface-wave amplitude analysis for array data with non-linear waveform fitting: Toward high-resolution attenuation models of the upper mantle

    Science.gov (United States)

    Hamada, K.; Yoshizawa, K.

    2013-12-01

    Anelastic attenuation of seismic waves provides us with valuable information on temperature and water content in the Earth's mantle. While seismic velocity models have been investigated by many researchers, anelastic attenuation (or Q) models have yet to be investigated in detail mainly due to the intrinsic difficulties and uncertainties in the amplitude analysis of observed seismic waveforms. To increase the horizontal resolution of surface wave attenuation models on a regional scale, we have developed a new method of fully non-linear waveform fitting to measure inter-station phase velocities and amplitude ratios simultaneously, using the Neighborhood Algorithm (NA) as a global optimizer. Model parameter space (perturbations of phase speed and amplitude ratio) is explored to fit two observed waveforms on a common great-circle path by perturbing both phase and amplitude of the fundamental-mode surface waves. This method has been applied to observed waveform data of the USArray from 2007 to 2008, and a large-number of inter-station amplitude and phase speed data are corrected in a period range from 20 to 200 seconds. We have constructed preliminary phase speed and attenuation models using the observed phase and amplitude data, with careful considerations of the effects of elastic focusing and station correction factors for amplitude data. The phase velocity models indicate good correlation with the conventional tomographic results in North America on a large-scale; e.g., significant slow velocity anomaly in volcanic regions in the western United States. The preliminary results of surface-wave attenuation achieved a better variance reduction when the amplitude data are inverted for attenuation models in conjunction with corrections for receiver factors. We have also taken into account the amplitude correction for elastic focusing based on a geometrical ray theory, but its effects on the final model is somewhat limited and our attenuation model show anti

  15. A model for filtered backprojection reconstruction artifacts due to time-varying attenuation values in perfusion C-arm CT

    Energy Technology Data Exchange (ETDEWEB)

    Fieselmann, Andreas; Hornegger, Joachim [Department of Computer Science, Pattern Recognition Lab, Friedrich-Alexander University of Erlangen-Nuremberg, Martensstr. 3, 91058 Erlangen (Germany); Dennerlein, Frank; Deuerling-Zheng, Yu; Boese, Jan [Siemens AG, Healthcare Sector, Angiography and Interventional X-Ray Systems, Siemensstr. 1, 91301 Forchheim (Germany); Fahrig, Rebecca, E-mail: andreas.fieselmann@informatik.uni-erlangen.de [Department of Radiology, Lucas MRS Center, Stanford University, 1201 Welch Road, Palo Alto, CA 94305 (United States)

    2011-06-21

    Filtered backprojection is the basis for many CT reconstruction tasks. It assumes constant attenuation values of the object during the acquisition of the projection data. Reconstruction artifacts can arise if this assumption is violated. For example, contrast flow in perfusion imaging with C-arm CT systems, which have acquisition times of several seconds per C-arm rotation, can cause this violation. In this paper, we derived and validated a novel spatio-temporal model to describe these kinds of artifacts. The model separates the temporal dynamics due to contrast flow from the scan and reconstruction parameters. We introduced derivative-weighted point spread functions to describe the spatial spread of the artifacts. The model allows prediction of reconstruction artifacts for given temporal dynamics of the attenuation values. Furthermore, it can be used to systematically investigate the influence of different reconstruction parameters on the artifacts. We have shown that with optimized redundancy weighting function parameters the spatial spread of the artifacts around a typical arterial vessel can be reduced by about 70%. Finally, an inversion of our model could be used as the basis for novel dynamic reconstruction algorithms that further minimize these artifacts.

  16. A model for filtered backprojection reconstruction artifacts due to time-varying attenuation values in perfusion C-arm CT

    Science.gov (United States)

    Fieselmann, Andreas; Dennerlein, Frank; Deuerling-Zheng, Yu; Boese, Jan; Fahrig, Rebecca; Hornegger, Joachim

    2011-06-01

    Filtered backprojection is the basis for many CT reconstruction tasks. It assumes constant attenuation values of the object during the acquisition of the projection data. Reconstruction artifacts can arise if this assumption is violated. For example, contrast flow in perfusion imaging with C-arm CT systems, which have acquisition times of several seconds per C-arm rotation, can cause this violation. In this paper, we derived and validated a novel spatio-temporal model to describe these kinds of artifacts. The model separates the temporal dynamics due to contrast flow from the scan and reconstruction parameters. We introduced derivative-weighted point spread functions to describe the spatial spread of the artifacts. The model allows prediction of reconstruction artifacts for given temporal dynamics of the attenuation values. Furthermore, it can be used to systematically investigate the influence of different reconstruction parameters on the artifacts. We have shown that with optimized redundancy weighting function parameters the spatial spread of the artifacts around a typical arterial vessel can be reduced by about 70%. Finally, an inversion of our model could be used as the basis for novel dynamic reconstruction algorithms that further minimize these artifacts.

  17. Interleukin 17A evoked mucosal damage is attenuated by cannabidiol and anandamide in a human colonic explant model.

    Science.gov (United States)

    Harvey, B S; Sia, T C; Wattchow, D A; Smid, S D

    2014-02-01

    Interleukin 17A (IL-17A) is a cytokine linked to inflammatory bowel disease. We investigated IL-17A expression in human colonic mucosa, whether IL-17A can elicit colonic mucosal damage in a human explant model and modulate gastrointestinal epithelial permeability in cell culture. We also tested if select cannabinoid ligands, shown to be protective in colitis models could attenuate damage caused by IL-17A. In addition, the ability of pro-inflammatory cytokines TNF-α and IL-1β to modulate levels of IL-17A in the explant colitis model was also explored. IL-17A incubation caused significant mucosal epithelial and crypt damage which were attenuated following hydrocortisone treatment, and also reduced following anandamide or cannabidiol incubation. IL-17A-evoked mucosal damage was also associated with an increase in matrix metalloprotease activity. However, IL-17A did not induce any significant changes in epithelial permeability in confluent Caco-2 cell monolayers over a 48h incubation period. IL-17A was located predominantly in human mucosal epithelium together with IL-17C, but both IL-17A and IL-17C were also expressed in the lamina propria and submucosa. Incubation of human colonic mucosal tissue or Caco-2 cells with pro-inflammatory cytokines TNF-α and IL-1β however did not alter IL-17A expression. These results indicate IL-17A has a widespread distribution in the human colon and the capacity to elicit mucosal damage which can be attenuated by cannabinoid ligands. PMID:24238999

  18. Teriflunomide attenuates immunopathological changes in the Dark Agouti rat model of experimental autoimmune encephalomyelitis

    Directory of Open Access Journals (Sweden)

    Garth E. Ringheim

    2013-10-01

    Full Text Available Teriflunomide is an oral disease-modifying therapy recently approved in several locations for relapsing forms of multiple sclerosis. To gain insight into the effects of teriflunomide, immunocyte population changes were measured during progression of experimental autoimmune encephalomyelitis in Dark Agouti rats. Treatment with teriflunomide attenuated levels of spinal cord-infiltrating T cells, natural killer cells, macrophages, and neutrophils. Teriflunomide also mitigated the disease-induced changes in immune cell populations in the blood and spleen suggesting an inhibitory effect on pathogenic immune responses.

  19. Photoacoustic Imaging Taking into Account Attenuation

    CERN Document Server

    Kowar, Richard

    2010-01-01

    First, we review existing attenuation models and discuss their causality properties, which we believe to be essential for algorithms for inversion with attenuated data. Then, we survey causality properties of common attenuation models. We also derive integro-differential equations which the attenuated waves are satisfying. In addition we discuss the ill--conditionness of the inverse problem for calculating the unattenuated wave from the attenuated one.

  20. Mesenchymal Stem Cell Attenuates Neutrophil-predominant Inflammation and Acute Lung Injury in an In Vivo Rat Model of Ventilator-induced Lung Injury

    OpenAIRE

    Tian-Shun Lai; Zhi-Hong Wang; Shao-Xi Cai

    2015-01-01

    Background: Subsequent neutrophil (polymorphonuclear neutrophil [PMN])-predominant inflammatory response is a predominant feature of ventilator-induced lung injury (VILI), and mesenchymal stem cell (MSC) can improve mice survival model of endotoxin-induced acute lung injury, reduce lung impairs, and enhance the repair of VILI. However, whether MSC could attenuate PMN-predominant inflammatory in the VILI is still unknown. This study aimed to test whether MSC intervention could attenuate the PM...

  1. Predicting attenuant and resonant 2-cycles in periodically forced discrete-time two-species population models.

    Science.gov (United States)

    Morena, Matthew A; Franke, John E

    2012-01-01

    Periodic environments may either enhance or suppress a population via resonant or attenuant cycles. We derive signature functions for predicting the responses of two competing populations to 2-periodic oscillations in six model parameters. Two of these parameters provide a non-trivial equilibrium and two provide the carrying capacities of each species in the absence of the other, but the remaining two are arbitrary and could be intrinsic growth rates. Each signature function is the sign of a weighted sum of the relative strengths of the oscillations of the perturbed parameters. Periodic environments are favourable for populations when the signature function is positive and are deleterious if the signature function is negative. We compute the signature functions of four classical, discrete-time two-species populations and determine regions in parameter space which are either favourable or detrimental to the populations. The six-parameter models include the Logistic, Ricker, Beverton-Holt, and Hassell models.

  2. A novel random void model and its application in predicting void content of composites based on ultrasonic attenuation coefficient

    Science.gov (United States)

    Lin, Li; Zhang, Xiang; Chen, Jun; Mu, Yunfei; Li, Ximeng

    2011-06-01

    A novel two-dimensional random void model (RVM) based on random medium theory and a statistical method is proposed to describe random voids in composite materials. The spatial autocorrelation function and statistical parameters are used to describe the large-scale heterogeneity from the composite matrix and the small-scale heterogeneities of elastic fluctuations from random voids, the values of which are determined by statistical data from microscopic observations of void morphology. A RVM for CFRP (carbon fiber reinforced polymer) composite specimens with void content of 0.03-4.62% is presented. It is found that the geometric morphology of voids from the RVM presents good matches to the microscopic images. Calculations of ultrasonic attenuation coefficients from the RVM at 5 MHz are much closer to the experiments than those from the previous deterministic model. Furthermore, the RVM can also cover abnormal coefficients from unusually large voids, which unpredictably occur during the composite preparation and have a detrimental effect on the strength and mechanical properties of the components. The significant enhancements in description of void morphology and quantitative correlation between void content and ultrasonic attenuation coefficient make this method a good candidate for predicting void content of composite materials non-destructively.

  3. Carnosine attenuates early brain injury through its antioxidative and anti-apoptotic effects in a rat experimental subarachnoid hemorrhage model.

    Science.gov (United States)

    Zhang, Zong-yong; Sun, Bao-liang; Yang, Ming-feng; Li, Da-wei; Fang, Jie; Zhang, Shuai

    2015-03-01

    Carnosine (β-alanyl-L-histidine) has been demonstrated to provide antioxidative and anti-apoptotic roles in the animal of ischemic brain injuries and neurodegenerative diseases. The aim of this study was to examine whether carnosine prevents subarachnoid hemorrhage (SAH)-induced early brain injury (EBI) in rats. We found that intraperitoneal administration of carnosine improved neurobehavioral deficits, attenuated brain edema and blood-brain barrier permeability, and decreased reactive oxygen species level at 48 h following SAH in rat models. Carnosine treatment increased tissue copper/zinc superoxide dismutase (CuZn-SOD) and glutathione peroxidase (GSH-Px) enzymatic activities, and reduced post-SAH elevated lactate dehydrogenase (LDH) activity, the concentration of malondialdehyde (MDA), 3-nitrotyrosine (3-NT), 8-hydroxydeoxyguanosine (8-OHDG), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) in rats. Furthermore, carnosine treatment attenuated SAH-induced microglia activation and cortical neuron apoptosis. These results indicated that administration of carnosine may provide neuroprotection in EBI following SAH in rat models. PMID:25179154

  4. Live Cell Analysis and Mathematical Modeling Identify Determinants of Attenuation of Dengue Virus 2'-O-Methylation Mutant.

    Directory of Open Access Journals (Sweden)

    Bianca Schmid

    2015-12-01

    Full Text Available Dengue virus (DENV is the most common mosquito-transmitted virus infecting ~390 million people worldwide. In spite of this high medical relevance, neither a vaccine nor antiviral therapy is currently available. DENV elicits a strong interferon (IFN response in infected cells, but at the same time actively counteracts IFN production and signaling. Although the kinetics of activation of this innate antiviral defense and the timing of viral counteraction critically determine the magnitude of infection and thus disease, quantitative and kinetic analyses are lacking and it remains poorly understood how DENV spreads in IFN-competent cell systems. To dissect the dynamics of replication versus antiviral defense at the single cell level, we generated a fully viable reporter DENV and host cells with authentic reporters for IFN-stimulated antiviral genes. We find that IFN controls DENV infection in a kinetically determined manner that at the single cell level is highly heterogeneous and stochastic. Even at high-dose, IFN does not fully protect all cells in the culture and, therefore, viral spread occurs even in the face of antiviral protection of naïve cells by IFN. By contrast, a vaccine candidate DENV mutant, which lacks 2'-O-methylation of viral RNA is profoundly attenuated in IFN-competent cells. Through mathematical modeling of time-resolved data and validation experiments we show that the primary determinant for attenuation is the accelerated kinetics of IFN production. This rapid induction triggered by mutant DENV precedes establishment of IFN-resistance in infected cells, thus causing a massive reduction of virus production rate. In contrast, accelerated protection of naïve cells by paracrine IFN action has negligible impact. In conclusion, these results show that attenuation of the 2'-O-methylation DENV mutant is primarily determined by kinetics of autocrine IFN action on infected cells.

  5. Deficiency of aldose reductase attenuates inner retinal neuronal changes in a mouse model of retinopathy of prematurity.

    Science.gov (United States)

    Fu, Zhongjie; Nian, Shen; Li, Suk-Yee; Wong, David; Chung, Sookja K; Lo, Amy C Y

    2015-09-01

    Retinopathy of prematurity (ROP) is a leading cause of childhood blindness where vascular abnormality and retinal dysfunction are reported. We showed earlier that genetic deletion of aldose reductase (AR), the rate-limiting enzyme in the polyol pathway, reduced the neovascularization through attenuating oxidative stress induction in the mouse oxygen-induced retinopathy (OIR) modeling ROP. In this study, we further investigated the effects of AR deficiency on retinal neurons in the mouse OIR. Seven-day-old wild-type and AR-deficient mice were exposed to 75 % oxygen for 5 days and then returned to room air. Electroretinography was used to assess the neuronal function at postnatal day (P) 30. On P17 and P30, retinal cytoarchitecture was examined by morphometric analysis and immunohistochemistry for calbindin, protein kinase C alpha, calretinin, Tuj1, and glial fibrillary acidic protein. In OIR, attenuated amplitudes and delayed implicit time of a-wave, b-wave, and oscillatory potentials were observed in wild-type mice, but they were not significantly changed in AR-deficient mice. The morphological changes of horizontal, rod bipolar, and amacrine cells were shown in wild-type mice and these changes were partly preserved with AR deficiency. AR deficiency attenuated the Müller cell gliosis induced in OIR. Our observations demonstrated AR deficiency preserved retinal functions in OIR and AR deficiency could partly reduce the extent of retinal neuronal histopathology. These findings suggested a therapeutic potential of AR inhibition in ROP treatment with beneficial effects on the retinal neurons. PMID:25921391

  6. Dissolved plume attenuation with DNAPL source remediation, aqueous decay and volatilization — Analytical solution, model calibration and prediction uncertainty

    Science.gov (United States)

    Parker, Jack C.; Park, Eungyu; Tang, Guoping

    2008-11-01

    A vertically-integrated analytical model for dissolved phase transport is described that considers a time-dependent DNAPL source based on the upscaled dissolution kinetics model of Parker and Park with extensions to consider time-dependent source zone biodecay, partial source mass reduction, and remediation-enhanced source dissolution kinetics. The model also considers spatial variability in aqueous plume decay, which is treated as the sum of aqueous biodecay and volatilization due to diffusive transport and barometric pumping through the unsaturated zone. The model is implemented in Excel/VBA coupled with (1) an inverse solution that utilizes prior information on model parameters and their uncertainty to condition the solution, and (2) an error analysis module that computes parameter covariances and total prediction uncertainty due to regression error and parameter uncertainty. A hypothetical case study is presented to evaluate the feasibility of calibrating the model from limited noisy field data. The results indicate that prediction uncertainty increases significantly over time following calibration, primarily due to propagation of parameter uncertainty. However, differences between the predicted performance of source zone partial mass reduction and the known true performance were reasonably small. Furthermore, a clear difference is observed between the predicted performance for the remedial action scenario versus that for a no-action scenario, which is consistent with the true system behavior. The results suggest that the model formulation can be effectively utilized to assess monitored natural attenuation and source remediation options if careful attention is given to model calibration and prediction uncertainty issues.

  7. Dissolved plume attenuation with DNAPL source remediation, aqueous decay and volatilization--analytical solution, model calibration and prediction uncertainty.

    Science.gov (United States)

    Parker, Jack C; Park, Eungyu; Tang, Guoping

    2008-11-14

    A vertically-integrated analytical model for dissolved phase transport is described that considers a time-dependent DNAPL source based on the upscaled dissolution kinetics model of Parker and Park with extensions to consider time-dependent source zone biodecay, partial source mass reduction, and remediation-enhanced source dissolution kinetics. The model also considers spatial variability in aqueous plume decay, which is treated as the sum of aqueous biodecay and volatilization due to diffusive transport and barometric pumping through the unsaturated zone. The model is implemented in Excel/VBA coupled with (1) an inverse solution that utilizes prior information on model parameters and their uncertainty to condition the solution, and (2) an error analysis module that computes parameter covariances and total prediction uncertainty due to regression error and parameter uncertainty. A hypothetical case study is presented to evaluate the feasibility of calibrating the model from limited noisy field data. The results indicate that prediction uncertainty increases significantly over time following calibration, primarily due to propagation of parameter uncertainty. However, differences between the predicted performance of source zone partial mass reduction and the known true performance were reasonably small. Furthermore, a clear difference is observed between the predicted performance for the remedial action scenario versus that for a no-action scenario, which is consistent with the true system behavior. The results suggest that the model formulation can be effectively utilized to assess monitored natural attenuation and source remediation options if careful attention is given to model calibration and prediction uncertainty issues. PMID:18502537

  8. Probucol attenuates atrial autonomic remodeling in a canine model of atrial fibrillation produced by prolonged atrial pacing

    Institute of Scientific and Technical Information of China (English)

    GONG Yong-tai; LI Wei-min; LI Yue; YANG Shu-sen; SHENG Li; YANG Ning; SHAN Hong-bo; XUE Hong-jie; LIU Wei; YANG Bao-feng; DONG De-li; LI Bao-xin

    2009-01-01

    Background We hypothesize that increased atrial oxidative stress and inflammation may play an important role in atrial nerve sprouting and heterogeneous sympathetic hyperinnervation during atrial fibrillation (AF). To test the hypothesis, we examined whether the antioxidant and anti-inflammatory treatment with probucol attenuates atrial autonomic remodeling in a canine model of AF produced by prolonged rapid right atrial pacing. Methods Twenty-one dogs were divided into a sham-operated group, a control group and a probucol group. Dogs in the control group and probucol group underwent right atrial pacing at 400 beats per minute for 6 weeks, and those in the probucol group received probucol 1 week before rapid atrial pacing until pacing stopped. After 6-week rapid atrial pacing, general properties including left atrial structure and function, atrial hemodynamics and the inducibility and duration of AF were measured in all the groups. Atrial oxidative stress markers and serum C-reactive protein (CRP) concentration were estimated. The degree of nerve sprouting and sympathetic innervation at the right atrial anterior wall (RAAW) and the left atrial anterior wall (LAAW) were quantified by immunohistochemistry, atdal norepinephrine contents were also detected. Atrial beta-nerve growth factor (beta-NGF) mRNA and protein expression at the RAAW and LAAW were assessed by real-time quantitative RT-PCR and Western blotting respectively. Results Atrial tachypacing induced significant nerve sprouting and heterogeneous sympathetic hyperinnervation, and the magnitude of nerve sprouting and hyperinnervation was higher in the RAAW than in the LAAW. Atrial beta-NGF mRNA and protein levels were significantly increased at the RAAW and LAAW, and the upregulation of beta-NGF expression was greater at the RAAW than at the LAAW in the control group. The beta-NGF protein level was positively correlated with the density of sympathetic nerves in all groups. Probucol decreased the increase of

  9. Partially hydrolyzed guar gum attenuates the severity of pouchitis in a rat model of ileal J pouch-anal anastomosis.

    Science.gov (United States)

    Atila, Koray; Terzi, Cem; Canda, Aras Emre; Akhisaroglu, Serpil Tanriverdi; Avci, Hatice Sanli; Sarioglu, Sulen; Oktay, Gulgun; Gulay, Zeynep

    2009-03-01

    We aimed to evaluate the efficacy of treatment with partially hydrolyzed guar gum (PHGG) using a rat model of ileal pouch-anal anastomosis and pouchitis. In the J pouch groups, tissue myeloperoxidase activities were significantly higher than native myeloperoxidase activities (P = 0.020; P = 0.015; P = 0.004, respectively). A statistically significant difference in total histological score was detected in the J pouch + 5% dextran sulfate sodium (DSS) group, compared to the J pouch control and the J pouch + 5% DSS + PHGG groups (P < 0.01 and P < 0.01, respectively). There was a significant overgrowth of aerobes and anaerobes in the J pouch + 5% DSS group. This study demonstrated that rectal administration of PHGG attenuates the severity of pouchitis in a rat model. In conclusion, PHGG may be an additional therapeutic strategy for the treatment of pouchitis. PMID:18594969

  10. Vanillin Attenuated Behavioural Impairments, Neurochemical Deficts, Oxidative Stress and Apoptosis Against Rotenone Induced Rat Model of Parkinson's Disease.

    Science.gov (United States)

    Dhanalakshmi, Chinnasamy; Janakiraman, Udaiyappan; Manivasagam, Thamilarasan; Justin Thenmozhi, Arokiasamy; Essa, Musthafa Mohamed; Kalandar, Ameer; Khan, Mohammed Abdul Sattar; Guillemin, Gilles J

    2016-08-01

    Vanillin (4-hydroxy-3-methoxybenzaldehyde), a pleasant smelling organic aromatic compound, is widely used as a flavoring additive in food, beverage, cosmetic and drug industries. It is reported to cross the blood brain barrier and also displayed antioxidant and neuroprotective activities. We previously reported the neuroprotective effect of vanillin against rotenone induced in in vitro model of PD. The present experiment was aimed to analyze the neuroprotective effect of vanillin on the motor and non-motor deficits, neurochemical variables, oxidative, anti-oxidative indices and the expression of apoptotic markers against rotenone induced rat model of Parkinson's disease (PD). Rotenone treatment exhibited motor and non-motor impairments, neurochemical deficits, oxidative stress and apoptosis, whereas oral administration of vanillin attenuated the above-said indices. However further studies are needed to explore the mitochondrial protective and anti-inflammatory properties of vanillin, as these processes play a vital role in the cause and progression of PD. PMID:27038927

  11. Vanillin Attenuated Behavioural Impairments, Neurochemical Deficts, Oxidative Stress and Apoptosis Against Rotenone Induced Rat Model of Parkinson's Disease.

    Science.gov (United States)

    Dhanalakshmi, Chinnasamy; Janakiraman, Udaiyappan; Manivasagam, Thamilarasan; Justin Thenmozhi, Arokiasamy; Essa, Musthafa Mohamed; Kalandar, Ameer; Khan, Mohammed Abdul Sattar; Guillemin, Gilles J

    2016-08-01

    Vanillin (4-hydroxy-3-methoxybenzaldehyde), a pleasant smelling organic aromatic compound, is widely used as a flavoring additive in food, beverage, cosmetic and drug industries. It is reported to cross the blood brain barrier and also displayed antioxidant and neuroprotective activities. We previously reported the neuroprotective effect of vanillin against rotenone induced in in vitro model of PD. The present experiment was aimed to analyze the neuroprotective effect of vanillin on the motor and non-motor deficits, neurochemical variables, oxidative, anti-oxidative indices and the expression of apoptotic markers against rotenone induced rat model of Parkinson's disease (PD). Rotenone treatment exhibited motor and non-motor impairments, neurochemical deficits, oxidative stress and apoptosis, whereas oral administration of vanillin attenuated the above-said indices. However further studies are needed to explore the mitochondrial protective and anti-inflammatory properties of vanillin, as these processes play a vital role in the cause and progression of PD.

  12. Kaempferol Attenuates Myocardial Ischemic Injury via Inhibition of MAPK Signaling Pathway in Experimental Model of Myocardial Ischemia-Reperfusion Injury

    Directory of Open Access Journals (Sweden)

    Kapil Suchal

    2016-01-01

    Full Text Available Kaempferol (KMP, a dietary flavonoid, has antioxidant, anti-inflammatory, and antiapoptotic effects. Hence, we investigated the effect of KMP in ischemia-reperfusion (IR model of myocardial injury in rats. We studied male albino Wistar rats that were divided into sham, IR-control, KMP-20 + IR, and KMP 20 per se groups. KMP (20 mg/kg; i.p. was administered daily to rats for the period of 15 days, and, on the 15th day, ischemia was produced by one-stage ligation of left anterior descending coronary artery for 45 min followed by reperfusion for 60 min. After completion of surgery, rats were sacrificed; heart was removed and processed for biochemical, morphological, and molecular studies. KMP pretreatment significantly ameliorated IR injury by maintaining cardiac function, normalizing oxidative stress, and preserving morphological alterations. Furthermore, there was a decrease in the level of inflammatory markers (TNF-α, IL-6, and NFκB, inhibition of active JNK and p38 proteins, and activation of ERK1/ERK2, a prosurvival kinase. Additionally, it also attenuated apoptosis by reducing the expression of proapoptotic proteins (Bax and Caspase-3, TUNEL positive cells, and increased level of antiapoptotic proteins (Bcl-2. In conclusion, KMP protected against IR injury by attenuating inflammation and apoptosis through the modulation of MAPK pathway.

  13. Association of the Host Immune Response with Protection Using a Live Attenuated African Swine Fever Virus Model

    Science.gov (United States)

    Carlson, Jolene; O’Donnell, Vivian; Alfano, Marialexia; Velazquez Salinas, Lauro; Holinka, Lauren G.; Krug, Peter W.; Gladue, Douglas P.; Higgs, Stephen; Borca, Manuel V.

    2016-01-01

    African swine fever (ASF) is a lethal hemorrhagic disease of swine caused by a double-stranded DNA virus, ASF virus (ASFV). There is no vaccine to prevent the disease and current control measures are limited to culling and restricting animal movement. Swine infected with attenuated strains are protected against challenge with a homologous virulent virus, but there is limited knowledge of the host immune mechanisms generating that protection. Swine infected with Pretoriuskop/96/4 (Pret4) virus develop a fatal severe disease, while a derivative strain lacking virulence-associated gene 9GL (Pret4Δ9GL virus) is completely attenuated. Swine infected with Pret4Δ9GL virus and challenged with the virulent parental virus at 7, 10, 14, 21, and 28 days post infection (dpi) showed a progressive acquisition of protection (from 40% at 7 dpi to 80% at 21 and 28 dpi). This animal model was used to associate the presence of host immune response (ASFV-specific antibody and interferon (IFN)-γ responses, or specific cytokine profiles) and protection against challenge. With the exception of ASFV-specific antibodies in survivors challenged at 21 and 28 dpi, no association between the parameters assessed and protection could be established. These results, encompassing data from 65 immunized swine, underscore the complexity of the system under study, suggesting that protection relies on the concurrence of different host immune mechanisms. PMID:27782090

  14. Restoring Spinal Noradrenergic Inhibitory Tone Attenuates Pain Hypersensitivity in a Rat Model of Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Lei-Fang Cao

    2016-01-01

    Full Text Available In the present study, we investigated whether restoring descending noradrenergic inhibitory tone can attenuate pain in a PD rat model, which was established by stereotaxic infusion of 6-hydroxydopamine (6-OHDA into the bilateral striatum (CPu. PD rats developed thermal and mechanical hypersensitivity at the 4th week after surgery. HPLC analysis showed that NE content, but not dopamine or 5-HT, significantly decreased in lumbar spinal cord in PD rats. Additional noradrenergic depletion by injection of N-(2-chloroethyl-N-ethyl-2-bromobenzylamine (DSP-4 aggravated pain hypersensitivity in PD rats. At the 5th week after injection of 6-OHDA, systemic treatment with pharmacological norepinephrine (NE precursor droxidopa (L-DOPS or α2 adrenoceptor agonist clonidine significantly attenuated thermal and mechanical pain hypersensitivity in PD rats. Furthermore, application of norepinephrine (NE and 5-hydroxytryptamine (5-HT reuptake inhibitors duloxetine, but not 5-HT selective reuptake inhibitors sertraline, significantly inhibited thermal and mechanical pain hypersensitivity in PD rats. Systemic administration of Madopar (L-DOPA or the D2/D3 agonist pramipexole slightly inhibited the thermal, but not mechanical, hypersensitivity in PD rats. Thus, our study revealed that impairment of descending noradrenergic system may play a key role in PD-associated pain and restoring spinal noradrenergic inhibitory tone may serve as a novel strategy to manage PD-associated pain.

  15. Resveratrol attenuates acute kidney injury by inhibiting death receptor‑mediated apoptotic pathways in a cisplatin‑induced rat model.

    Science.gov (United States)

    Hao, Qiufa; Xiao, Xiaoyan; Zhen, Junhui; Feng, Jinbo; Song, Chun; Jiang, Bei; Hu, Zhao

    2016-10-01

    Acute kidney injury is a clinical syndrome characterized by a loss of renal function and acute tubular necrosis. Resveratrol exerts a wide range of pharmacological effects based on its anti‑inflammatory, antioxidant and cytoprotective properties. The present study aimed to evaluate whether resveratrol attenuates acute kidney injury in a cisplatin‑induced rat model and to investigate the potential mechanisms involved. Rats were randomly divided into four treatment groups: control, cisplatin, resveratrol, and cisplatin plus resveratrol. Rats exposed to cisplatin displayed acute kidney injury, identified by analysis of renal function and histopathological observation. Resveratrol significantly ameliorated the increased serum creatinine, blood urea nitrogen, renal index and histopathological damage induced by cisplatin. Furthermore, compared with untreated control animals, cisplatin lead to significantly increased expression of Fas ligand, tumor necrosis factor‑α (TNF‑α), caspase‑8 and Bcl‑2 associated protein X apoptosis regulator (Bax), and decreased expression of anti‑apoptosis regulators, BH3 interacting domain death agonist (BID) and B cell lymphoma 2 apoptosis regulator (Bcl‑2). Administration of resveratrol significantly reversed the cisplatin‑induced alteration in these apoptosis‑associated proteins. In conclusion, these findings suggest that resveratrol attenuates cisplatin‑induced acute kidney injury through inactivation of the death receptor‑mediated apoptotic pathway, and may provide a new therapeutic strategy to ameliorate the process of acute kidney injury. PMID:27600998

  16. Lycopene attenuates Aβ1-42 secretion and its toxicity in human cell and Caenorhabditis elegans models of Alzheimer disease.

    Science.gov (United States)

    Chen, Wei; Mao, Liuqun; Xing, Huanhuan; Xu, Lei; Fu, Xiang; Huang, Liyingzi; Huang, Dongling; Pu, Zhijun; Li, Qinghua

    2015-11-01

    Growing evidence suggests concentration of lycopene was reduced in plasma of patients with Alzheimer disease (AD). Lycopene, a member of the carotenoid family, has been identified as an antioxidant to attenuate oxidative damage and has neuroprotective role in several AD models. However, whether lycopene is involved in the pathogenesis of AD and molecular underpinnings are elusive. In this study, we found that lycopene can significantly delay paralysis in the Aβ1-42-transgenic Caenorhabditis elegans strain GMC101. Lycopene treatment reduced Aβ1-42 secretion in SH-SY5Y cells overexpressing the Swedish mutant form of human β-amyloid precursor protein (APPsw). Next, we found lycopene can down-regulate expression level of β-amyloid precursor protein(APP) in APPsw cells. Moreover, lycopene treatment can not change endogenous reactive oxygen species level and apoptosis in APPsw cells. However, lycopene treatment protected against H2O2-induced oxidative stress and copper-induced damage in APPsw cells. Collectively, our data support that elevated lycopene contributes to the lower pathogenesis of AD. Our findings suggest that increasing lycopene in neurons may be a novel approach to attenuate onset and development of AD.

  17. Physical and statistical modeling of attenuation due to atmospheric hydrometeors on free-space optical links at 850 and 1550 nm

    Science.gov (United States)

    Grabner, Martin; Kvicera, Vaclav

    2012-10-01

    Atmospheric hydrometeors such as rain and fog may cause attenuation of an optical signal and degrade the performance of free-space optical (FSO) systems. For efficient design of the FSO links, attenuation characteristics must be predicted by sufficiently reliable models that have been tested on experimental data. A long term experiment on the FSO links operating at 850 and 1550 nm wavelengths is conducted in Prague. The path lengths are 100 and 853 m. Received power fluctuations on the FSO links and relevant meteorological quantities such as rain intensity and liquid water content of fog are measured simultaneously. The relationships between the physical parameters of hydrometeors and path attenuation are analyzed and compared with theoretical relations derived using the Mie scattering theory together with some natural assumptions about the physical properties of scattering particles such as droplet size distribution of different types of hydrometeors. Long term statistics of attenuation are obtained and availability performance of the experimental FSO links is assessed. The method for predicting attenuation statistics based on physical and statistical models is introduced and the errors of the proposed models with respect to measured data are analyzed. The models are compared with the existing empirical relationships derived from other FSO experiments and differences are discussed.

  18. [Optical properties and remote sensing retrieval model of diffuse attenuation coefficient of Taihu Lake water body].

    Science.gov (United States)

    Le, Cheng-Feng; Li, Yun-Mei; Zha, Yong; Sun, De-Yong; Wang, Li-Zhen

    2009-02-01

    The spectral and chemical analytical data of Taihu Lake water quality in Nov. 8-22, 2007 were used to analyze the spectral characteristics of diffuse attenuation coefficient (Kd) of the water body in autumn and related affecting factors. On the basis of this analysis, the Kd at band 490 nm, Kd (490), was used as a variable to build the relationship between Kd and remote sensing reflectance. The results indicated that within the scope of visible band, the Kd of the water body at most locations of Taihu Lake presented an exponent decreasing trend with the increase of wave length. Due to the higher concentration of phytoplankton in some locations, a peak value of Kd was presented at band 675 nm. Non-organic suspended particles, because of their higher content in suspended sediment, had larger effects on Kd than organic suspended ones. There was a good correlation between Kd and remote sensing reflectance. Taking Rrs (550), Rrs (675) and Rrs (731) as independent variables and doing regression analysis with Kd (490), a good linear relationship was found between Kd (490) and Rrs (731), and multi-variate linear regression analysis using variables Rrs (550), Rrs (675) and Rrs (731) could get better effect (R2 > 0.96) than the regression analysis using variable Rrs (731). PMID:19459373

  19. Frequency Dependent Attenuation Revisited

    CERN Document Server

    Richard, Kowar; Xavier, Bonnefond

    2009-01-01

    The work is inspired by thermo-and photoacoustic imaging, where recent efforts are devoted to take into account attenuation and varying wave speed parameters. In this paper we study causal equations describing propagation of attenuated pressure waves. We review standard models like frequency power laws and and the thermo-viscous equation. The lack of causality of standard models in the parameter range relevant for photoacoustic imaging requires to derive novel equations. The main ingredients for deriving causal equations are the Kramers-Kronig relation and the mathematical concept of linear system theory. The theoretical results of this work are underpined by numerical experiments.

  20. The CNTF-derived peptide mimetic Cintrofin attenuates spatial-learning deficits in a rat post-status epilepticus model

    DEFF Research Database (Denmark)

    Russmann, Vera; Seeger, Natalie; Zellinger, Christina;

    2013-01-01

    Ciliary neurotrophic growth factor is considered a potential therapeutic agent for central nervous system diseases. We report first in vivo data of the ciliary neurotrophic growth factor peptide mimetic Cintrofin in a rat post-status epilepticus model. Cintrofin prevented long-term alterations...... in the number of doublecortin-positive neuronal progenitor cells and attenuated the persistence of basal dendrites. In contrast, Cintrofin did neither affect acute status epilepticus-associated alterations in hippocampal cell proliferation and neurogenesis nor reveal any relevant effect on seizure activity....... Whereas status epilepticus caused a significant disturbance in spatial learning in reversed peptide-treated rats, the performance of Cintrofin-treated rats did not differ from controls. The study confirms that Cintrofin comprises an active sequence mimicking effects of its parent molecule. While the data...

  1. Modeling and Experiment of the Suspended Seismometer Concept for Attenuating the Contribution of Tilt Motion in Horizontal Measurements

    CERN Document Server

    Matichard, F; Mittleman, R; McInnis, M; Biscans, S; Dooley, K L; Sohier, H; Lauriero, A; Paris, H; Koch, J; Knothe, P; Carbajo, A; Dufort, C

    2016-01-01

    Tilt-horizontal coupling in inertial sensors limits the performance of active isolation systems such as those used in gravitational wave detectors. Inertial rotation sensors can be used to subtract the tilt component from the signal produced by horizontal inertial sensors, but such techniques are often limited by the sensor noise of the tilt measurement. A different approach is to mechanically filter the tilt transmitted to the horizontal inertial sensor, as discussed in this article. This technique does not require an auxiliary rotation sensor, and can produce a lower noise measurement. The concept investigated uses a mechanical suspension to isolate the inertial sensor from input tilt. Modeling and simulations show that such a configuration can be used to adequately attenuate the tilt transmitted to the instrument, while maintaining translation sensitivity in the frequency band of interest. The analysis is supported by experimental results showing that this approach is a viable solution to overcome the tilt...

  2. Planetary Ices Attenuation Properties

    Science.gov (United States)

    McCarthy, Christine; Castillo-Rogez, Julie C.

    In this chapter, we review the topic of energy dissipation in the context of icy satellites experiencing tidal forcing. We describe the physics of mechanical dissipation, also known as attenuation, in polycrystalline ice and discuss the history of laboratory methods used to measure and understand it. Because many factors - such as microstructure, composition and defect state - can influence rheological behavior, we review what is known about the mechanisms responsible for attenuation in ice and what can be inferred from the properties of rocks, metals and ceramics. Since attenuation measured in the laboratory must be carefully scaled to geologic time and to planetary conditions in order to provide realistic extrapolation, we discuss various mechanical models that have been used, with varying degrees of success, to describe attenuation as a function of forcing frequency and temperature. We review the literature in which these models have been used to describe dissipation in the moons of Jupiter and Saturn. Finally, we address gaps in our present knowledge of planetary ice attenuation and provide suggestions for future inquiry.

  3. Notoginsenoside R1 attenuates atherosclerotic lesions in ApoE deficient mouse model.

    Directory of Open Access Journals (Sweden)

    Chenglin Jia

    Full Text Available AIMS: Atherosclerosis is the primary cause of cardiovascular diseases and stroke. The current study evaluated the interventional effects of a naturally occurring compound Notoginsenoside R1 (NR1 on atherosclerosis in ApoE-/- mice. METHODS AND RESULTS: The atherosclerotic lesion was significantly alleviated by NR1 treatment and this attenuation was marked by reduction in lipid deposition, fibrosis and oxidative stress. Increased serum levels of GSH and SOD and decreased level of MDH were observed in NR1-treated ApoE-/- mice. NR1 treatment also significantly decreased the levels of CHO, TG, ox-LDL and increased the level of HDL. Additionally, the levels of inflammatory cytokines including IL-2, IL-6, TNF-α and γ-IFN were markedly reduced in NR1-treated ApoE-/- mice. Furthermore, significantly increased aortic expression of miR-26a, miR-21, miR-126a, miR-132, miR-146 and miR-155 and decreased expression of miR-20a and miR-92a were observed in the vehicle-treated ApoE-/- mice. While NR1 treatment led to a significant reduction in the expression of miR-21, miR-26a, miR-126 and increased expression of miR-20a. CONCLUSION: Collectively, our results demonstrated for the first time the anti-atherosclerotic effects of NR1, which could be in part mediated through its multiple targeting effects on inflammation, oxidative stress, lipid metabolism and microRNA expression. These results therefore justify further evaluation of NR1 as a therapeutic agent treating atherosclerosis.

  4. Osthole attenuates hepatic injury in a rodent model of trauma-hemorrhage.

    Science.gov (United States)

    Yu, Huang-Ping; Liu, Fu-Chao; Tsai, Yung-Fong; Hwang, Tsong-Long

    2013-01-01

    Recent evidences show that osthole possesses anti-inflammatory properties and protective effects following shock-like states, but the mechanism of these effects remains unknown. The p38 mitogen-activated protein kinase (p38 MAPK) pathway exerts anti-inflammatory effects in injury. The aim of this study was to investigate whether p38 MAPK plays any role in the osthole-mediated attenuation of hepatic injury after trauma-hemorrhage. Male Sprague-Dawley rats underwent trauma-hemorrhage (mean blood pressure maintained at approximately 35-40 mmHg for 90 minutes), followed by fluid resuscitation. During resuscitation, a single dose of osthole (3 mg/kg, intravenously) with and without a p38 MAPK inhibitor SB-203580 (2 mg/kg, intravenously), SB-203580 or vehicle was administered. Plasma alanine aminotransferase (ALT) with aspartate aminotransferase (AST) concentrations and various hepatic parameters were measured (n = 8 rats/group) at 24 hours after resuscitation. The results showed that trauma-hemorrhage increased hepatic myeloperoxidase activity, intercellular adhesion molecule-1 and interleukin-6 levels, and plasma ALT and AST concentrations. These parameters were significantly improved in the osthole-treated rats subjected to trauma-hemorrhage. Osthole treatment also increased hepatic phospho-p38 MAPK expression compared with vehicle-treated trauma-hemorrhaged rats. Co-administration of SB-203580 with osthole abolished the osthole-induced beneficial effects on the above parameters and hepatic injury. These results suggest that the protective effect of osthole administration on alleviation of hepatic injury after trauma-hemorrhage, which is, at least in part, through p38 MAPK-dependent pathway. PMID:23755293

  5. Combination of epinephrine with esmolol attenuates post-resuscitation myocardial dysfunction in a porcine model of cardiac arrest.

    Directory of Open Access Journals (Sweden)

    Qian Zhang

    Full Text Available BACKGROUND: Recent experimental and clinical studies have indicated that the β-adrenergic effect of epinephrine significantly increases the severity of post resuscitation myocardial dysfunction. The aim of the study was to investigate whether the short-acting β₁-selective adrenergic blocking agent, esmolol, would attenuate post resuscitation myocardial dysfunction in a porcine model of cardiac arrest. METHODS AND RESULTS: After 8 min of untreated ventricular fibrillation and 2 min of basic life support, 24 pigs were randomized to three groups (n = 8 per group, which received central venous injection of either epinephrine combined with esmolol (EE group, epinephrine (EP group, or saline (SA group. Hemodynamic status and blood samples were obtained at 0, 30, 60, 120, 240 and 360 min after return of spontaneous circulation (ROSC. Surviving pigs were euthanatized at 24 h after ROSC, and the hearts were removed for analysis by electron microscopy, Western blotting, quantitative real-time polymerase chain reaction, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL assay. Compared with the EP and SA groups, EE group had a better outcome in hemodynamic function, (improved dp/dt maxima and minima and cardiac output (P<0.05, and improved oxygen metabolism (oxygen delivery and oxygen consumption (P<0.05, which suggesting that EE can protect myocardial tissue from injury and improve post-resuscitation myocardial dysfunction. The protective effect of EE also correlated with reducing cardiomyocyte apoptosis, evidenced by reducing TUNEL-positive cells, increasing anti-apoptotic Bcl-2/Bax ratio and suppression of caspase-3 activity in myocardium. CONCLUSIONS: Esmolol, a short-acting β₁-selective adrenergic blocking agent, given during CPR has significant effects on attenuating post resuscitation myocardial dysfunction. The current study provides a potential pharmacologic target for post resuscitation myocardial dysfunction.

  6. A blueberry-enriched diet attenuates nephropathy in a rat model of hypertension via reduction in oxidative stress.

    Directory of Open Access Journals (Sweden)

    Carrie M Elks

    Full Text Available To assess renoprotective effects of a blueberry-enriched diet in a rat model of hypertension. Oxidative stress (OS appears to be involved in the development of hypertension and related renal injury. Pharmacological antioxidants can attenuate hypertension and hypertension-induced renal injury; however, attention has shifted recently to the therapeutic potential of natural products as antioxidants. Blueberries (BB have among the highest antioxidant capacities of fruits and vegetables.Male spontaneously hypertensive rats received a BB-enriched diet (2% w/w or an isocaloric control diet for 6 or 12 weeks or 2 days. Compared to controls, rats fed BB-enriched diet for 6 or 12 weeks exhibited lower blood pressure, improved glomerular filtration rate, and decreased renovascular resistance. As measured by electron paramagnetic resonance spectroscopy, significant decreases in total reactive oxygen species (ROS, peroxynitrite, and superoxide production rates were observed in kidney tissues in rats on long-term dietary treatment, consistent with reduced pathology and improved function. Additionally, measures of antioxidant status improved; specifically, renal glutathione and catalase activities increased markedly. Contrasted to these observations indicating reduced OS in the BB group after long-term feeding, similar measurements made in rats fed the same diet for only 2 days yielded evidence of increased OS; specifically, significant increases in total ROS, peroxynitrite, and superoxide production rates in all tissues (kidney, brain, and liver assayed in BB-fed rats. These results were evidence of "hormesis" during brief exposure, which dissipated with time as indicated by enhanced levels of catalase in heart and liver of BB group.Long-term feeding of BB-enriched diet lowered blood pressure, preserved renal hemodynamics, and improved redox status in kidneys of hypertensive rats and concomitantly demonstrated the potential to delay or attenuate development

  7. Use of noise attenuation modeling in managing missile motor detonation activities.

    Science.gov (United States)

    McFarland, Michael J; Watkins, Jeffrey W; Kordich, Micheal M; Pollet, Dean A; Palmer, Glenn R

    2004-03-01

    The Sound Intensity Prediction System (SIPS) and Blast Operation Overpressure Model (BOOM) are semiempirical sound models that are employed by the Utah Test and Training Range (UTTR) to predict whether noise levels from the detonation of large missile motors will exceed regulatory thresholds. Field validation of SIPS confirmed that the model was effective in limiting the number of detonations of large missile motors that could potentially result in a regulatory noise exceedance. Although the SIPS accurately predicted the impact of weather on detonation noise propagation, regulators have required that the more conservative BOOM model be employed in conjunction with SIPS in evaluating peak noise levels in populated areas. By simultaneously considering the output of both models, in 2001, UTTR detonated 104 missile motors having net explosive weights (NEW) that ranged between 14,960 and 38,938 lb without a recorded public noise complaint. Based on the encouraging results, the U.S. Department of Defense is considering expanding the application of these noise models to support the detonation of missile motors having a NEW of 81,000 lb. Recent modeling results suggest that, under appropriate weather conditions, missile motors containing up to 96,000 lb NEW can be detonated at the UTTR without exceeding the regulatory noise limit of 134 decibels (dB).

  8. Tomography of atomic number and density of materials using dual-energy imaging and the Alvarez and Macovski attenuation model

    Science.gov (United States)

    Paziresh, M.; Kingston, A. M.; Latham, S. J.; Fullagar, W. K.; Myers, G. M.

    2016-06-01

    Dual-energy computed tomography and the Alvarez and Macovski [Phys. Med. Biol. 21, 733 (1976)] transmitted intensity (AMTI) model were used in this study to estimate the maps of density (ρ) and atomic number (Z) of mineralogical samples. In this method, the attenuation coefficients are represented [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)] in the form of the two most important interactions of X-rays with atoms that is, photoelectric absorption (PE) and Compton scattering (CS). This enables material discrimination as PE and CS are, respectively, dependent on the atomic number (Z) and density (ρ) of materials [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976)]. Dual-energy imaging is able to identify sample materials even if the materials have similar attenuation coefficients at single-energy spectrum. We use the full model rather than applying one of several applied simplified forms [Alvarez and Macovski, Phys. Med. Biol. 21, 733 (1976); Siddiqui et al., SPE Annual Technical Conference and Exhibition (Society of Petroleum Engineers, 2004); Derzhi, U.S. patent application 13/527,660 (2012); Heismann et al., J. Appl. Phys. 94, 2073-2079 (2003); Park and Kim, J. Korean Phys. Soc. 59, 2709 (2011); Abudurexiti et al., Radiol. Phys. Technol. 3, 127-135 (2010); and Kaewkhao et al., J. Quant. Spectrosc. Radiat. Transfer 109, 1260-1265 (2008)]. This paper describes the tomographic reconstruction of ρ and Z maps of mineralogical samples using the AMTI model. The full model requires precise knowledge of the X-ray energy spectra and calibration of PE and CS constants and exponents of atomic number and energy that were estimated based on fits to simulations and calibration measurements. The estimated ρ and Z images of the samples used in this paper yield average relative errors of 2.62% and 1.19% and maximum relative errors of 2.64% and 7.85%, respectively. Furthermore, we demonstrate that the method accounts for the beam hardening effect in density (ρ) and

  9. Extraction procedure compared to attenuation model to assess heavy metals mobility in sediments from Sepetiba Bay, Rio de Janeiro

    International Nuclear Information System (INIS)

    , for Zn, and as level 1, for Cd, Cu, Pb and Ni, according to the CONAMA 344/04 act. A geostatistical approach is presented, the attenuation of concentrations model, which aims to estimate metal mobility in sediments. The proposed model showed the highest attenuation values for Zn, Cd, Cu and Pb in the northeastern region, indicating that the mobility of these metals is low in this region, suggesting low availability, which is in good agreement with the results obtained by the SIGMA[SEM]/[AVS] model. These results indicate good possibilities of applying this model in metal contamination studies in estuarine ecosystems. (author)

  10. Exercise intervention increases spontaneous locomotion but fails to attenuate dopaminergic system loss in a progressive MPTP model in aged mice.

    Science.gov (United States)

    Hood, Rebecca L; Liguore, William A; Moore, Cynthia; Pflibsen, Lacey; Meshul, Charles K

    2016-09-01

    While exercise is commonly recommended for PD patients to improve motor function, little is known about the disease-altering potential of exercise. Although others have demonstrated neuroprotective or neurorestorative effects of exercise in animal models of PD, the majority of these studies utilize young animals. In order to assess the effects of exercise intervention in a more clinically relevant model, we have subjected aged mice to progressive 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) lesioning and daily treadmill exercise, initiated early in the course of the disease. The MPTP model elicited a 55% reduction in striatal TH as measured by immunohistochemistry compared to sedentary controls, and exercise did not attenuate this loss in exercised MPTP animals. Furthermore, striatal TH and DAT loss, as assessed by western blotting, were not significantly impacted by treadmill exercise in MPTP-lesioned mice. We did find an increase in spontaneous locomotion in exercised mice that was not decreased by MPTP lesioning. This finding may be due, in part, to an increase in TH expression in the motor cortex in exercised MPTP mice. PMID:27350080

  11. A DJ-1 Based Peptide Attenuates Dopaminergic Degeneration in Mice Models of Parkinson's Disease via Enhancing Nrf2.

    Directory of Open Access Journals (Sweden)

    Nirit Lev

    Full Text Available Drugs currently used for treating Parkinson's disease patients provide symptomatic relief without altering the neurodegenerative process. Our aim was to examine the possibility of using DJ-1 (PARK7, as a novel therapeutic target for Parkinson's disease. We designed a short peptide, named ND-13. This peptide consists of a 13 amino acids segment of the DJ-1-protein attached to 7 amino acids derived from TAT, a cell penetrating protein. We examined the effects of ND-13 using in vitro and in vivo experimental models of Parkinson's disease. We demonstrated that ND-13 protects cultured cells against oxidative and neurotoxic insults, reduced reactive oxygen species accumulation, activated the protective erythroid-2 related factor 2 system and increased cell survival. ND-13 robustly attenuated dopaminergic system dysfunction and in improved the behavioral outcome in the 6-hydroxydopamine mouse model of Parkinson's disease, both in wild type and in DJ-1 knockout mice. Moreover, ND-13 restored dopamine content in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine mouse model. These findings validate DJ-1 as a promising therapeutic target in Parkinson's disease and identify a novel peptide with clinical potential, which may be significant for a broader range of neurological diseases, possibly with an important impact for the neurosciences.

  12. An empirical assessment of exposure measurement errors and effect attenuation in bi-pollutant epidemiologic models

    Science.gov (United States)

    Using multipollutant models to understand the combined health effects of exposure to multiple pollutants is becoming more common. However, the complex relationships between pollutants and differing degrees of exposure error across pollutants can make health effect estimates from ...

  13. Assimilation of remotely-sensed diffuse attenuation data to improve the simulation of a marine ecosystem model

    Science.gov (United States)

    Ciavatta, Stefano; Torres, Ricardo; Martinez-Vicente, Victor; Smyth, Timothy; Dall'Olmo, Giorgio; Polimene, Luca; Allen, Icarus

    2014-05-01

    Biogeochemical processes in shelf seas and coastal areas can determine the health and productivity of local systems and are important terms of the global carbon budget. The quantitative characterization of the spatial-temporal evolution of biogeochemical variables in shelf-seas is thus relevant in the framework of marine system management and climate change studies In this work we evaluate, for the first time, whether the assimilation of remotely-sensed diffuse attenuation coefficient data into a marine ecosystem model can improve the simulation of key biogeochemical variables and processes in a shelf sea. A localized Ensemble Kalman filter was used to assimilate weekly SeaWiFS data of diffuse light attenuation coefficient, i.e. Kd(443), into an ecosystem model of the western English Channel, for the simulation of year 2006. The spatial distributions of (unassimilated) surface chlorophyll from SeaWiFS, and eighteen time series of biogeochemical and optical data measured weekly at the monitoring station L4 were used to evaluate the system performance. A comparative assimilation experiment was run by using SeaWiFS chlorophyll data. We found that Kd(443) assimilation reduced the root mean square error and improved the correlation with the assimilated satellite observations in the largest part area of the WEC. The error for the (unassimilated) chlorophyll tended to decrease as well, but the estimates deteriorated in some parts of the study area. Assimilation of Kd(443) provided better estimates of the (unassimilated) in situ data when compared with both the reference simulation and chlorophyll assimilation. Indeed, model RMSE and bias of the estimates decreased for more than a half of the variables, and the skill metrics resulted in general better for the assimilation of the optical data. Importantly, assimilation of Kd(443) impacted the simulation of biogeochemical fluxes and ecosystem processes (e.g. shifted the simulated food web towards the microbial loop), and in

  14. Oral Bromelain Attenuates Inflammation in an Ovalbumin-Induced Murine Model of Asthma

    OpenAIRE

    Secor, Eric R.; Carson, William F.; Anurag Singh; Mellisa Pensa; Guernsey, Linda A.; Craig M. Schramm; Thrall, Roger S.

    2008-01-01

    Bromelain, a widely used pineapple extract with cysteine protease activity, has been shown to have immunomodulatory effects in a variety of immune system models. The purpose of the present study was to determine the effects of orally administered bromelain in an ovalbumin (OVA)-induced murine model of acute allergic airway disease (AAD). To establish AAD, female C57BL/6J mice were sensitized with intraperitoneal (i.p.) OVA/alum and then challenged with OVA aerosols for 3 days. Mice were gavag...

  15. Inhibition of neutrophil elastase attenuates airway hyperresponsiveness and inflammation in a mouse model of secondary allergen challenge: neutrophil elastase inhibition attenuates allergic airway responses

    Directory of Open Access Journals (Sweden)

    Koga Hikari

    2013-01-01

    Full Text Available Abstract Background Chronic asthma is often associated with neutrophilic infiltration in the airways. Neutrophils contain elastase, a potent secretagogue in the airways, nonetheless the role for neutrophil elastase as well as neutrophilic inflammation in allergen-induced airway responses is not well defined. In this study, we have investigated the impact of neutrophil elastase inhibition on the development of allergic airway inflammation and airway hyperresponsiveness (AHR in previously sensitized and challenged mice. Methods BALB/c mice were sensitized and challenged (primary with ovalbumin (OVA. Six weeks later, a single OVA aerosol (secondary challenge was delivered and airway inflammation and airway responses were monitored 6 and 48 hrs later. An inhibitor of neutrophil elastase was administered prior to secondary challenge. Results Mice developed a two-phase airway inflammatory response after secondary allergen challenge, one neutrophilic at 6 hr and the other eosinophilic, at 48 hr. PAR-2 expression in the lung tissues was enhanced following secondary challenge, and that PAR-2 intracellular expression on peribronchial lymph node (PBLN T cells was also increased following allergen challenge of sensitized mice. Inhibition of neutrophil elastase significantly attenuated AHR, goblet cell metaplasia, and inflammatory cell accumulation in the airways following secondary OVA challenge. Levels of IL-4, IL-5 and IL-13, and eotaxin in BAL fluid 6 hr after secondary allergen challenge were significantly suppressed by the treatment. At 48 hr, treatment with the neutrophil elastase inhibitor significantly reduced the levels of IL-13 and TGF-β1 in the BAL fluid. In parallel, in vitro IL-13 production was significantly inhibited in spleen cells from sensitized mice. Conclusion These data indicate that neutrophil elastase plays an important role in the development of allergic airway inflammation and hyperresponsiveness, and would suggest that the

  16. Inhibition of classical complement activation attenuates liver ischaemia and reperfusion injury in a rat model

    NARCIS (Netherlands)

    B.H.M. Heijnen; I.H. Straatsburg; N.D. Padilla; G.J. Mierlo; C.E. Hack; T.M. van Gulik

    2006-01-01

    Activation of the complement system contributes to the pathogenesis of ischaemia/reperfusion (I/R) injury. We evaluated inhibition of the classical pathway of complement using C1-inhibitor (C1-inh) in a model of 70% partial liver I/R injury in male Wistar rats (n = 35). C1-inh was administered at 10

  17. Histone deacetylase inhibitor treatment attenuates coagulation imbalance in a lethal murine model of sepsis

    DEFF Research Database (Denmark)

    Zhao, Ting; Li, Yongqing; Liu, Baoling;

    2014-01-01

    with suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor (HDACI), improves survival in a lethal model of cecal ligation and puncture (CLP) in mice, but its effect on coagulation remains unknown. The goal of this study was to quantify the impact of SAHA treatment on coagulopathy in sepsis. METHODS...

  18. A stochastic model of range profiles of raindrop size distributions: application to radar attenuation correction

    NARCIS (Netherlands)

    Berne, A.D.; Uijlenhoet, R.

    2005-01-01

    To analyze the influence of the spatial variability of the raindrop size distribution (DSD) on rainfall estimation using weather radar, a stochastic model is proposed in order to simulate range profiles of DSDs and consequently profiles of rainfall intensity, radar reflectivity and specific attenuat

  19. Focal axonal swellings and associated ultrastructural changes attenuate conduction velocity in central nervous system axons: a computer modeling study.

    Science.gov (United States)

    Kolaric, Katarina V; Thomson, Gemma; Edgar, Julia M; Brown, Angus M

    2013-08-01

    The constancy of action potential conduction in the central nervous system (CNS) relies on uniform axon diameter coupled with fidelity of the overlying myelin providing high-resistance, low capacitance insulation. Whereas the effects of demyelination on conduction have been extensively studied/modeled, equivalent studies on the repercussions for conduction of axon swelling, a common early pathological feature of (potentially reversible) axonal injury, are lacking. The recent description of experimentally acquired morphological and electrical properties of small CNS axons and oligodendrocytes prompted us to incorporate these data into a computer model, with the aim of simulating the effects of focal axon swelling on action potential conduction. A single swelling on an otherwise intact axon, as occurs in optic nerve axons of Cnp1 null mice caused a small decrease in conduction velocity. The presence of single swellings on multiple contiguous internodal regions (INR), as likely occurs in advanced disease, caused qualitatively similar results, except the dimensions of the swellings required to produce equivalent attenuation of conduction were significantly decreased. Our simulations of the consequences of metabolic insult to axons, namely, the appearance of multiple swollen regions, accompanied by perturbation of overlying myelin and increased axolemmal permeability, contained within a single INR, revealed that conduction block occurred when the dimensions of the simulated swellings were within the limits of those measured experimentally, suggesting that multiple swellings on a single axon could contribute to axonal dysfunction, and that increased axolemmal permeability is the decisive factor that promotes conduction block. PMID:24303138

  20. Purpurogallin, a Natural Phenol, Attenuates High-Mobility Group Box 1 in Subarachnoid Hemorrhage Induced Vasospasm in a Rat Model

    Directory of Open Access Journals (Sweden)

    Chih-Zen Chang

    2014-01-01

    Full Text Available High-mobility group box 1 (HMGB1 was shown to be an important extracellular mediator involved in vascular inflammation of animals following subarachnoid hemorrhage (SAH. This study is of interest to examine the efficacy of purpurogallin, a natural phenol, on the alternation of cytokines and HMGB1 in a SAH model. A rodent double hemorrhage SAH model was employed. Basilar arteries (BAs were harvested to examine HMGB1 mRNA and protein expression (Western blot. CSF samples were to examine IL-1β, IL-6, IL-8, and TNF-α (rt-PCR. Deformed endothelial wall, tortuous elastic lamina, and necrotic smooth muscle were observed in the vessels of SAH groups but were absent in the purpurogallin group. IL-1β, IL-6, and TNF-α in the SAH only and SAH plus vehicle groups were significantly elevated (P<0.01. Purpurgallin dose-dependently reduced HMGB1 protein expression. Likewise, high dose purpurogallin reduced TNF-α and HMGB1 mRNA levels. In conclusion, purpurogallin exerts its neuroinflammation effect through the dual effect of inhibiting IL-6 and TNF-α mRNA expression and reducing HMGB1 protein and mRNA expression. This study supports purpurogallin could attenuate both proinflammatory cytokines and late-onset inflammasome in SAH induced vasospasm.

  1. Antibody-Mediated Inhibition of TNFR1 Attenuates Disease in a Mouse Model of Multiple Sclerosis

    OpenAIRE

    Williams, Sarah K.; Olaf Maier; Roman Fischer; Richard Fairless; Sonja Hochmeister; Aleksandar Stojic; Lara Pick; Doreen Haar; Sylvia Musiol; Maria K Storch; Klaus Pfizenmaier; Ricarda Diem

    2014-01-01

    Tumour necrosis factor (TNF) is a proinflammatory cytokine that is known to regulate inflammation in a number of autoimmune diseases, including multiple sclerosis (MS). Although targeting of TNF in models of MS has been successful, the pathological role of TNF in MS remains unclear due to clinical trials where the non-selective inhibition of TNF resulted in exacerbated disease. Subsequent experiments have indicated that this may have resulted from the divergent effects of the two TNF receptor...

  2. Aerobic Exercise Attenuates Airway Inflammatory Responses in a Mouse Model of Atopic Asthma

    OpenAIRE

    Pastva, Amy; Estell, Kim; Schoeb, Trenton R.; Atkinson, T. Prescott; Schwiebert, Lisa M

    2004-01-01

    Recent reports indicate that aerobic exercise improves the overall physical fitness and health of asthmatic patients. The specific exercise-induced improvements in the pathology of asthma and the mechanisms by which these improvements occur, however, are ill-defined; thus, the therapeutic potential of exercise in the treatment of asthma remains unappreciated. Using an OVA-driven mouse model, we examined the role of aerobic exercise in modulating inflammatory responses associated with atopic a...

  3. Modeling Gamma-Ray Attenuation in High-Redshift GeV Spectra

    CERN Document Server

    Gilmore, Rudy C; Primack, Joel R; Somerville, Rachel S

    2008-01-01

    We present two models for the cosmological UV background light, and calculate the opacity of GeV gamma--rays out to redshift 9. The contributors to the background include 2 possible quasar emissivities, and output from star--forming galaxies as determined by recent a semi--analytic model (SAM) of structure formation. The SAM used in this work is based upon a hierarchical build-up of structure in a $\\Lambda$CDM universe and is highly successful in reproducing a variety of observational parameters. Above 1 Rydberg energy, ionizing radiation is subject to reprocessing by the IGM, which we treat using our radiative transfer code, CUBA. The two models for quasar emissivity differing above z = 2.3 are chosen to match the ionization rates observed using flux decrement analysis and the higher values of the line-of-sight proximity effect. We also investigate the possibility of a flat star formation rate density at z $>5$. We conclude that observations of gamma--rays from 10 to 100 GeV by Fermi (GLAST) and the next gen...

  4. Oral Bromelain Attenuates Inflammation in an Ovalbumin-Induced Murine Model of Asthma

    Directory of Open Access Journals (Sweden)

    Eric R. Secor

    2008-01-01

    Full Text Available Bromelain, a widely used pineapple extract with cysteine protease activity, has been shown to have immunomodulatory effects in a variety of immune system models. The purpose of the present study was to determine the effects of orally administered bromelain in an ovalbumin (OVA-induced murine model of acute allergic airway disease (AAD. To establish AAD, female C57BL/6J mice were sensitized with intraperitoneal (i.p. OVA/alum and then challenged with OVA aerosols for 3 days. Mice were gavaged with either (phosphate buffered salinePBS or 200 mg/kg bromelain in PBS, twice daily for four consecutive days, beginning 1 day prior to OVA aerosol challenge. Airway reactivity and methacholine sensitivity, bronchoalveolar lavage (BAL cellular differential, Th2 cytokines IL-5 and IL-13, and lung histology were compared between treatment groups. Oral bromelain-treatment of AAD mice demonstrated therapeutic efficacy as evidenced by decreased methacholine sensitivity (P ≤ 0.01, reduction in BAL eosinophils (P ≤ 0.02 and IL-13 concentrations (P ≤ 0.04 as compared with PBS controls. In addition, oral bromelain significantly reduced BAL CD19+ B cells (P ≤ 0.0001 and CD8+ T cells (P ≤ 0.0001 in AAD mice when compared with controls. These results suggest that oral treatment with bromelain had a beneficial therapeutic effect in this murine model of asthma and bromelain may also be effective in human conditions.

  5. Plasminogen Activator Inhibitor-1 Antagonist TM5484 Attenuates Demyelination and Axonal Degeneration in a Mice Model of Multiple Sclerosis.

    Directory of Open Access Journals (Sweden)

    Nicolas Pelisch

    Full Text Available Multiple sclerosis (MS is characterized by inflammatory demyelination and deposition of fibrinogen in the central nervous system (CNS. Elevated levels of a critical inhibitor of the mammalian fibrinolitic system, plasminogen activator inhibitor 1 (PAI-1 have been demonstrated in human and animal models of MS. In experimental studies that resemble neuroinflammatory disease, PAI-1 deficient mice display preserved neurological structure and function compared to wild type mice, suggesting a link between the fibrinolytic pathway and MS. We previously identified a series of PAI-1 inhibitors on the basis of the 3-dimensional structure of PAI-1 and on virtual screening. These compounds have been reported to provide a number of in vitro and in vivo benefits but none was tested in CNS disease models because of their limited capacity to penetrate the blood-brain barrier (BBB. The existing candidates were therefore optimized to obtain CNS-penetrant compounds. We performed an in vitro screening using a model of BBB and were able to identify a novel, low molecular PAI-1 inhibitor, TM5484, with the highest penetration ratio among all other candidates. Next, we tested the effects on inflammation and demyelination in an experimental allergic encephalomyelitis mice model. Results were compared to either fingolimod or 6α-methylprednisolone. Oral administration of TM5484 from the onset of signs, ameliorates paralysis, attenuated demyelination, and axonal degeneration in the spinal cord of mice. Furthermore, it modulated the expression of brain-derived neurotrophic factor, which plays a protective role in neurons against various pathological insults, and choline acetyltransferase, a marker of neuronal density. Taken together, these results demonstrate the potential benefits of a novel PAI-1 inhibitor, TM5484, in the treatment of MS.

  6. CMV infection attenuates the disease course in a murine model of multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Istvan Pirko

    Full Text Available Recent evidence in multiple sclerosis (MS suggests that active CMV infection may result in more benign clinical disease. The goal of this pilot study was to determine whether underlying murine CMV (MCMV infection affects the course of the Theiler's murine encephalitis virus (TMEV induced murine model of MS. A group of eight TMEV-infected mice were co-infected with MCMV at 2 weeks prior to TMEV infection while a second group of TMEV-infected mice received MCMV two weeks post TMEV. We also used 2 control groups, where at the above time points MCMV was replaced with PBS. Outcome measures included (1 monthly monitoring of disability via rotarod for 8 months; (2 in vivo MRI for brain atrophy studies and (3 FACS analysis of brain infiltrating lymphocytes at 8 months post TMEV infection. Co-infection with MCMV influenced the disease course in mice infected prior to TMEV infection. In this group, rotarod detectable motor performance was significantly improved starting 3 months post-infection and beyond (p≤0.024. In addition, their brain atrophy was close to 30% reduced at 8 months, but this was only present as a trend due to low power (p = 0.19. A significant reduction in the proportion of brain infiltrating CD3+ cells was detected in this group (p = 0.026, while the proportion of CD45+ Mac1+ cells significantly increased (p = 0.003. There was also a strong trend for a reduced proportion of CD4+ cells (p = 0.17 while CD8 and B220+ cell proportion did not change. These findings support an immunomodulatory effect of MCMV infection in this MS model. Future studies in this co-infection model will provide insight into mechanisms which modulate the development of demyelination and may be utilized for the development of novel therapeutic strategies.

  7. SU-F-BRE-10: Methods to Simulate and Measure the Attenuation for Modeling a Couch Top with Rails for FFF Treatment Delivery On the Varian Edge Linac

    Energy Technology Data Exchange (ETDEWEB)

    Gulam, M; Gardner, S; Zhao, B; Snyder, K; Song, K; Li, H; Gordon, J; Wen, N; Chetty, I [Henry Ford Health System, Detroit, MI (United States); Kearns, W [Varian Medical Systems, Clemmons, NC (United States)

    2014-06-15

    Purpose: To measure attenuation for modelling of the KVue Couchtop for 6X and 10X FFF SRS/SBRT treatment Methods: Treatment planning simulation studies were done using 6X FFF beams to estimate the dosimetric impact of KVue couchtops (including the Q-Fix IGRT [carbon fiber] and Calypso [nonconductive Kevlar material]) with a structure model obtained from a research workstation (Eclipse, advanced planning interface (API) v13). Prior to installation on the Varian Edge linac, the couchtop along with (Kevlar) rails were CT scanned with the rails at various positions. An additional scan with the couchtop 15cm above the CT table top was obtained with 20cm solid water to facilitate precised/indexed data acquisition. Measurements for attenuation were obtained for field sizes of 2, 4 and 10 cm{sup 2} at 42 gantry angles including 6 pairs of opposing fields and other angles for oblique delivery where the beams traversed the couchtop and or rails. The delivery was fully automated with xml scripts running in developer mode. The results were then used to determine an accurate structure model for AAA (Eclipse v11) planning of IMRT and RapidArc delivery. Results: The planning simulation relative dose attenuation for oblique entry was not significantly different than the Exact IGRT or BrainLab iBeam couch except that the rails added 6% additional attenuation. The relative attenuation measurements for PA, PA (rails: inner position), oblique, oblique (rails: outer position), oblique (rails: inner position) were: −2.0%, −2.5%, −15.6%, −2.5%, −5.0% for 6X FFF and −1.4%, −1.5%, −12.2%, − 2.5%, −5.0% for 10X FFF with slight decrease in attenuation versus field size. A Couch structure model (with HU values) was developed. Calculation compared to measurement showed good agreement except for oblique (rails: outer position) where differences approached a magnitude of 6%. Conclusion: A model of the couch structures has been developed accounting for attenuation for FFF

  8. SU-F-BRE-10: Methods to Simulate and Measure the Attenuation for Modeling a Couch Top with Rails for FFF Treatment Delivery On the Varian Edge Linac

    International Nuclear Information System (INIS)

    Purpose: To measure attenuation for modelling of the KVue Couchtop for 6X and 10X FFF SRS/SBRT treatment Methods: Treatment planning simulation studies were done using 6X FFF beams to estimate the dosimetric impact of KVue couchtops (including the Q-Fix IGRT [carbon fiber] and Calypso [nonconductive Kevlar material]) with a structure model obtained from a research workstation (Eclipse, advanced planning interface (API) v13). Prior to installation on the Varian Edge linac, the couchtop along with (Kevlar) rails were CT scanned with the rails at various positions. An additional scan with the couchtop 15cm above the CT table top was obtained with 20cm solid water to facilitate precised/indexed data acquisition. Measurements for attenuation were obtained for field sizes of 2, 4 and 10 cm2 at 42 gantry angles including 6 pairs of opposing fields and other angles for oblique delivery where the beams traversed the couchtop and or rails. The delivery was fully automated with xml scripts running in developer mode. The results were then used to determine an accurate structure model for AAA (Eclipse v11) planning of IMRT and RapidArc delivery. Results: The planning simulation relative dose attenuation for oblique entry was not significantly different than the Exact IGRT or BrainLab iBeam couch except that the rails added 6% additional attenuation. The relative attenuation measurements for PA, PA (rails: inner position), oblique, oblique (rails: outer position), oblique (rails: inner position) were: −2.0%, −2.5%, −15.6%, −2.5%, −5.0% for 6X FFF and −1.4%, −1.5%, −12.2%, − 2.5%, −5.0% for 10X FFF with slight decrease in attenuation versus field size. A Couch structure model (with HU values) was developed. Calculation compared to measurement showed good agreement except for oblique (rails: outer position) where differences approached a magnitude of 6%. Conclusion: A model of the couch structures has been developed accounting for attenuation for FFF beams

  9. Afzelin attenuates asthma phenotypes by downregulation of GATA3 in a murine model of asthma.

    Science.gov (United States)

    Zhou, Wenbo; Nie, Xiuhong

    2015-07-01

    Asthma is a serious health problem causing significant mortality and morbidity globally. Persistent airway inflammation, airway hyperresponsiveness, increased immunoglobulin E (IgE) levels and mucus hypersecretion are key characteristics of the condition. Asthma is mediated via a dominant T-helper 2 (Th2) immune response, causing enhanced expression of Th2 cytokines. These cytokines are responsible for the various pathological changes associated with allergic asthma. To investigate the anti-asthmatic potential of afzelin, as well as the underlying mechanisms involved, its anti-asthmatic potential were investigated in a murine model of asthma. In the present study, BALB/c mice were systemically sensitized using ovalbumin (OVA) followed by aerosol allergen challenges. The effect of afzelin on airway hyperresponsiveness, eosinophilic infiltration, Th2 cytokine and OVA‑specific IgE production in a mouse model of asthma were investigated. It was found that afzelin‑treated groups suppressed eosinophil infiltration, allergic airway inflammation, airway hyperresponsiveness, OVA-specific IgE and Th2 cytokine secretion. The results of the present study suggested that the therapeutic mechanism by which afzelin effectively treats asthma is based on reduction of Th2 cytokine via inhibition of GATA-binding protein 3 transcription factor, which is the master regulator of Th2 cytokine differentiation and production. PMID:25738969

  10. Recombinant human deoxyribonuclease attenuates oxidative stress in a model of eosinophilic pulmonary response in mice.

    Science.gov (United States)

    da Cunha, Aline Andrea; Nuñez, Nailê Karine; de Souza, Rodrigo Godinho; Vargas, Mauro Henrique Moraes; Silveira, Josiane Silva; Antunes, Géssica Luana; Schmitz, Felipe; de Souza Wyse, Angela Terezinha; Jones, Marcus Herbert; Pitrez, Paulo Márcio

    2016-02-01

    The inflammatory cells infiltrating the airways produce several mediators, such as reactive oxygen species (ROS). ROS and the oxidant-antioxidant imbalance might play an important role in the modulation of airways inflammation. In order to avoid the undesirable effects of ROS, various endogenous antioxidant strategies have evolved, incorporating both enzymatic and non-enzymatic mechanisms. Recombinant human deoxyribonuclease (rhDNase) in clinical studies demonstrated a reduction in sputum viscosity, cleaving extracellular DNA in the airways, and facilitating mucus clearance, but an antioxidant effect was not studied so far. Therefore, we evaluated whether the administration of rhDNase improves oxidative stress in a murine model of asthma. Mice were sensitized by two subcutaneous injections of ovalbumin (OVA), on days 0 and 7, followed by three lung challenges with OVA on days 14, 15, and 16. On days 15 and 16, after 2 h of the challenge with OVA, mice received 1 mg/mL of rhDNase in the lungs. Bronchoalveolar lavage fluid and lung tissue were obtained on day 17, for inflammatory and oxidative stress analysis. We showed that rhDNase did not alter the population of inflammatory cells, such as eosinophil cells, in OVA-treated rhDNase group but significantly improved oxidative stress in lung tissue, by decreasing oxygen reactive species and increasing superoxide dismutase/catalase ratio, glutathione peroxidase activity, and thiol content. Our data provide the first evidence that rhDNase decreases some measures of oxidative stress and antioxidant status in a murine model of asthma, with a potential antioxidant effect to be further studied in human asthma. PMID:26738487

  11. Disruption of MeCP2 attenuates circadian rhythm in CRISPR/Cas9-based Rett syndrome model mouse.

    Science.gov (United States)

    Tsuchiya, Yoshiki; Minami, Yoichi; Umemura, Yasuhiro; Watanabe, Hitomi; Ono, Daisuke; Nakamura, Wataru; Takahashi, Tomoyuki; Honma, Sato; Kondoh, Gen; Matsuishi, Toyojiro; Yagita, Kazuhiro

    2015-12-01

    Methyl-CpG-binding protein 2 (Mecp2) is an X-linked gene encoding a methylated DNA-binding nuclear protein which regulates transcriptional activity. The mutation of MECP2 in humans is associated with Rett syndrome (RTT), a neurodevelopmental disorder. Patients with RTT frequently show abnormal sleep patterns and sleep-associated problems, in addition to autistic symptoms, raising the possibility of circadian clock dysfunction in RTT. In this study, we investigated circadian clock function in Mecp2-deficient mice. We successfully generated both male and female Mecp2-deficient mice on the wild-type C57BL/6 background and PER2(Luciferase) (PER2(Luc)) knock-in background using the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system. Generated Mecp2-deficient mice recapitulated reduced activity in mouse models of RTT, and their activity rhythms were diminished in constant dark conditions. Furthermore, real-time bioluminescence imaging showed that the amplitude of PER2(Luc)-driven circadian oscillation was significantly attenuated in Mecp2-deficient SCN neurons. On the other hand, in vitro circadian rhythm development assay using Mecp2-deficient mouse embryonic stem cells (ESCs) did not show amplitude changes of PER2(Luc) bioluminescence rhythms. Together, these results show that Mecp2 deficiency abrogates the circadian pacemaking ability of the SCN, which may be a therapeutic target to treat the sleep problems of patients with RTT.

  12. Pyruvate dehydrogenase kinase 2 and 4 gene deficiency attenuates nociceptive behaviors in a mouse model of acute inflammatory pain.

    Science.gov (United States)

    Jha, Mithilesh Kumar; Rahman, Md Habibur; Park, Dong Ho; Kook, Hyun; Lee, In-Kyu; Lee, Won-Ha; Suk, Kyoungho

    2016-09-01

    Pyruvate dehydrogenase (PDH) kinases (PDKs) 1-4, expressed in peripheral and central tissues, regulate the activity of the PDH complex (PDC). The PDC is an important mitochondrial gatekeeping enzyme that controls cellular metabolism. The role of PDKs in diverse neurological disorders, including neurometabolic aberrations and neurodegeneration, has been described. Implications for a role of PDKs in inflammation and neurometabolic coupling led us to investigate the effect of genetic ablation of PDK2/4 on nociception in a mouse model of acute inflammatory pain. Deficiency in Pdk2 and/or Pdk4 in mice led to attenuation of formalin-induced nociceptive behaviors (flinching, licking, biting, or lifting of the injected paw). Likewise, the pharmacological inhibition of PDKs substantially diminished the nociceptive responses in the second phase of the formalin test. Furthermore, formalin-provoked paw edema formation and mechanical and thermal hypersensitivities were significantly reduced in Pdk2/4-deficient mice. Formalin-driven neutrophil recruitment at the site of inflammation, spinal glial activation, and neuronal sensitization were substantially lessened in the second or late phase of the formalin test in Pdk2/4-deficient animals. Overall, our results suggest that PDK2/4 can be a potential target for the development of pharmacotherapy for the treatment of acute inflammatory pain. © 2016 Wiley Periodicals, Inc. PMID:26931482

  13. Naringin attenuates granule cell dispersion in the dentate gyrus in a mouse model of temporal lobe epilepsy.

    Science.gov (United States)

    Jang, Hannah; Jeong, Kyoung Hoon; Kim, Sang Ryong

    2016-07-01

    Morphological abnormalities of the dentate gyrus (DG) are an important phenotype in the hippocampus of patients with temporal lobe epilepsy. We recently reported that naringin, a bioflavonoid in grapefruit and citrus fruits, exerts beneficial effects in the kainic acid (KA) mouse model of epilepsy. We found that naringin treatment reduced seizure activities and decreased autophagic stress and neuroinflammation in the hippocampus following in vivo lesion with KA. However, it remains unclear whether naringin may also attenuate seizure-induced morphological changes in the DG, collectively known as granule cell dispersion (GCD). To clarify whether naringin treatment reduces GCD, we evaluated the effects of intraperitoneal injection of naringin on GCD and activation of mammalian target of rapamycin complex 1 (mTORC1), an important regulator of GCD, following intrahippocampal injection of KA. Our results showed that naringin treatment significantly reduced KA-induced GCD and mTORC1 activation, which was confirmed by assessing the phosphorylated form of the mTORC1 substrate, 4E-BP1, in the hippocampus. These results suggest that naringin treatment may help prevent epilepsy-induced hippocampal injury by inhibiting mTORC1 activation and thereby reducing GCD in the hippocampus in vivo.

  14. PD-L1 Blockade Attenuated Sepsis-Induced Liver Injury in a Mouse Cecal Ligation and Puncture Model

    Directory of Open Access Journals (Sweden)

    Weimin Zhu

    2013-01-01

    Full Text Available Liver plays a major role in hypermetabolism and produces acute phase proteins during systemic inflammatory response syndrome and it is of vital importance in host defense and bacteria clearance. Our previous studies indicated that programmed death-1 (PD-1 and its ligand programmed death ligand-1 (PD-L1 are crucial modulators of host immune responses during sepsis. Our current study was designed to investigate the role of PD-L1 in sepsis-induced liver injury by a mouse cecal ligation and puncture (CLP model. Our results indicated that there was a significant increase of PD-L1 expression in liver after CLP challenge compared to sham-operated controls, in terms of levels of mRNA transcription and immunohistochemistry. Anti-PD-L1 antibody significantly alleviated the morphology of liver injury in CLP mice. Anti-PD-L1 antibody administration decreased ALT and AST release in CLP mice, decreased the levels of tumor necrosis factor (TNF-α, interleukin (IL-6, and IL-10 mRNA in liver after sepsis challenge. Thus, anti-PD-L1 antibody might have a therapeutic potential in attenuating liver injury in sepsis.

  15. Naringin attenuates granule cell dispersion in the dentate gyrus in a mouse model of temporal lobe epilepsy.

    Science.gov (United States)

    Jang, Hannah; Jeong, Kyoung Hoon; Kim, Sang Ryong

    2016-07-01

    Morphological abnormalities of the dentate gyrus (DG) are an important phenotype in the hippocampus of patients with temporal lobe epilepsy. We recently reported that naringin, a bioflavonoid in grapefruit and citrus fruits, exerts beneficial effects in the kainic acid (KA) mouse model of epilepsy. We found that naringin treatment reduced seizure activities and decreased autophagic stress and neuroinflammation in the hippocampus following in vivo lesion with KA. However, it remains unclear whether naringin may also attenuate seizure-induced morphological changes in the DG, collectively known as granule cell dispersion (GCD). To clarify whether naringin treatment reduces GCD, we evaluated the effects of intraperitoneal injection of naringin on GCD and activation of mammalian target of rapamycin complex 1 (mTORC1), an important regulator of GCD, following intrahippocampal injection of KA. Our results showed that naringin treatment significantly reduced KA-induced GCD and mTORC1 activation, which was confirmed by assessing the phosphorylated form of the mTORC1 substrate, 4E-BP1, in the hippocampus. These results suggest that naringin treatment may help prevent epilepsy-induced hippocampal injury by inhibiting mTORC1 activation and thereby reducing GCD in the hippocampus in vivo. PMID:27040812

  16. Lactobacillus rhamnosus HN001 attenuates allergy development in a pig model.

    Directory of Open Access Journals (Sweden)

    Debra J Thomas

    Full Text Available BACKGROUND: Probiotics have been studied as immunomodulatory agents of allergy. Several human probiotic trials tracking the development of eczema and other forms of allergy have yielded inconsistent results. A recent infant study demonstrated that pre and postnatal Lactobacillus rhamnosus HN001 (HN001 supplementation decreased the prevalence of eczema and IgE associated eczema. However, the influence of HN001 on the incidence of wheeze, asthma, and/or other allergic manifestations has yet to be reported. OBJECTIVE: This study was conducted to determine the effects of the probiotic HN001 on the development of allergic lung disease in a pig model. METHODS: Allergy was induced by a series of subcutaneous and intratracheal sensitizations with Ascaris suum allergen (ASA during a six week time frame in post-weanling pigs supplemented daily with HN001, or without supplementation. One week following final sensitization intradermal skin tests and respiratory challenges were conducted. RESULTS: In response to intradermal and respiratory challenges, ASA-sensitized pigs fed HN001 had less severe skin flare reactions, smaller increases in pleural pressure, and trends towards lower changes in arterial oxygen and carbon dioxide partial pressure levels compared to control pigs. The frequency of ASA-specific IFN-γ-secreting peripheral blood mononuclear cells, as well as the amount of IL-10 produced by ASA-specific cells, was of greater magnitude in probiotic-fed pigs compared to control animals. These observations suggest that differences in clinical responses to the allergen challenges may be related to probiotic-induced modulation of Th1 (IFN-γ and regulatory (IL-10 cytokine expression. CONCLUSIONS: Probiotic supplementation decreased the severity of allergic skin and lung responses in allergen-sensitized pigs with a corresponding increase in IFN-γ expression. A similar correlation between certain allergic responses and increased IFN-γ expression has been

  17. EP1 DISRUPTION ATTENUATES END-ORGAN DAMAGE IN A MOUSE MODEL OF HYPERTENSION

    Science.gov (United States)

    Swan, Christina E.; Boyd, Kelli L.; Harris, Raymond C.; Zent, Roy; Breyer, Richard M.

    2012-01-01

    PGE2 is a major prostanoid found in the kidney and vasculature contributing to the regulation of blood pressure. The PGE2 receptor EP1 has been shown to contribute to hypertension by mediating angiotensin II-dependent vasoconstriction, although its precise role is incompletely characterized. Disruption of the EP1 receptor in C57BL/6J mice reduced the incidence of mortality during severe hypertension induced by uninephrectomy, deoxycorticosterone acetate, and angiotensin II. Mortality was dependent on all components of the model. Death was a result of aortic aneurysm rupture or occurred after development of anasarca, each of which was reduced in EP1−/− mice. Mean arterial pressure was increased in treated EP1+/+ and EP1−/− mice, however this elevation was significantly lower in EP1−/− mice. Blood pressure reduction via administration of hydralazine phenocopied EP1−/− mice. Thus reduction in blood pressure by disruption of EP1 reduced incidence of mortality and decreased organ damage suggesting that EP1 receptor blockade may be a viable target for anti-hypertensive therapy. PMID:23006735

  18. Jatrorrhizine hydrochloride attenuates hyperlipidemia in a high-fat diet-induced obesity mouse model.

    Science.gov (United States)

    Yang, Weiwei; She, Liping; Yu, Kun; Yan, Shan; Zhang, Xuefeng; Tian, Xiaoyi; Ma, Shuren; Zhang, Xiwen

    2016-10-01

    Jatrorrhizine hydrochloride (JH) is an active component of the traditional Chinese herb Coptis chinensis, which has been used to prevent and treat metabolic disorders. Hyperlipidemia is one of the principal factors underlying numerous metabolic diseases, including diabetes and obesity. Therefore, the aim of the present study was to investigate the lipid lowering effects of JH treatment in vivo in an obesity mouse model. JH-treated hyperlipidemic mice exhibited a reduction in body weight, as well as improved glucose tolerance and insulin sensitivity. In addition, JH‑treated hyperlipidemic mice exhibited reduced serum triglyceride, total cholesterol and low‑density lipoprotein cholesterol levels, as well as increased high‑density lipoprotein cholesterol levels compared with untreated mice fed a high‑fat diet. Notably, JH treatment ameliorated the pathophysiological changes observed in the livers of hyperlipidemic mice. At the molecular level, JH downregulated the hepatic mRNA expression levels of SREBP‑1c and FAS, and induced PPAR‑α and CPT1A mRNA expression in hyperlipidemic mice. These findings suggest that JH ameliorates hyperlipidemia via the suppression of lipogenesis and the enhancement of lipid oxidation in the liver. PMID:27573054

  19. Polyhydroxylated fullerene nanoparticles attenuate brain infarction and oxidative stress in rat model of ischemic stroke

    Science.gov (United States)

    Vani, Javad Rasouli; Mohammadi, Mohammad Taghi; Foroshani, Mahsa Sarami; Jafari, Mahvash

    2016-01-01

    Oxidative stress is the common underlying mechanism of damage in ischemic stroke. Therefore, we aimed to evaluate the possible protective effects of polyhydroxylated fullerene derivatives on brain infarction and oxidative/nitrosative stress in a rat model of ischemic stroke. The experiment was performed by four groups of rats (each; n=12); Sham, Control ischemia, and ischemic treatment groups (Pretreatment and Posttreatment). Brain ischemia was induced by 90 min middle cerebral artery occlusion (MCAO) followed by 24 hours reperfusion. Rats received fullerene nanoparticles at dose of 1 mg/kg 30 min before MCAO and immediately after beginning of reperfusion. Infarct volume, contents of malondialdehyde (MDA), glutathione (GSH) and nitrate as well as superoxide dismutase (SOD) activity were assessed 24 hours after termination of MCAO. Brain infarct volume was 310 ± 21 mm3 in control group. Administration of fullerene nanoparticles before and after MCAO significantly decreased the infarct volume by 53 % (145 ± 45 mm3) and 81 % (59 ± 13 mm3), respectively. Ischemia also enhanced MDA and nitrate contents of ischemic hemispheres by 45 % and 25 % , respectively. Fullerene nanoparticles considerably reduced the MDA and nitrate contents of ischemic hemispheres before MCAO by 58 % and 17 % , respectively, and after MCAO by 38 % and 21 % , respectively. Induction of MCAO significantly decreased GSH content (19 % ) and SOD activity (52 % ) of ischemic hemispheres, whereas fullerene nanoparticles increased the GSH content and SOD activity of ischemic hemispheres by 19 % and 52 % before MCAO, respectively, and 21 % and 55 % after MCAO, respectively. Our findings indicate that fullerene nanoparticles, as a potent scavenger of free radicals, protect the brain cells against ischemia/reperfusion injury and inhibit brain oxidative/nitrosative damage.

  20. Rapamycin Blocks Fibrocyte Migration and Attenuates Bronchiolitis Obliterans in a Murine Model

    Science.gov (United States)

    Gillen, Jacob R.; Zhao, Yunge; Harris, David A.; LaPar, Damien J.; Stone, Matthew L.; Fernandez, Lucas G.; Kron, Irving L.; Lau, Christine L.

    2014-01-01

    Background Fibrocytes are integral in the development of fibroproliferative disease. The CXCL12/CXCR4 chemokine axis has been shown to play a central role in fibrocyte migration and the development of bronchiolitis obliterans post lung transplantation. Inhibition of the mTOR (mammalian target of rapamycin) pathway with rapamycin has been shown to decrease expression of both CXCR4 and its receptor agonist, CXCL12. Thus, we hypothesize that rapamycin treatment would decrease fibrocyte trafficking into tracheal allografts and prevent bronchiolitis obliterans. Methods A total alloantigenic mismatch, murine heterotopic tracheal transplant model of bronchiolitis obliterans was used. Animals were either treated with rapamycin or dimethyl sulfoxide (DMSO) for 14 days post tracheal transplant. Fibrocyte levels were assessed via flow cytometry, and allograft neutrophil, CD3+ T-cell, macrophage, and smooth muscle actin levels were assessed via immunohistochemistry. Tracheal luminal obliteration was assessed on hematoxylin and eosin stains. Results Compared to DMSO controls, rapamycin-treated mice showed a significant decrease in fibrocyte levels in tracheal allografts. Fibrocytes levels in recipient’s blood showed a similar pattern, although not statistically significant. Furthermore, animals treated with rapamycin showed a significant decrease in tracheal allograft luminal obliteration compared to controls. Based on immunohistochemistry analyses, populations of α-SMA positive cells, neutrophils, CD3+ T-cells, and macrophages were all decreased in rapamycin-treated allograft versus DMSO controls. Conclusions Rapamycin effectively reduces recruitment of fibrocytes into tracheal allografts and mitigates development of tracheal luminal fibrosis. Further studies are needed to determine the cellular and molecular mechanisms that mediate the protective effect of rapamycin against bronchiolitis obliterans. PMID:23561805

  1. Puerarin Attenuates Ovalbumin-Induced Lung Inflammation and Hemostatic Unbalance in Rat Asthma Model

    Directory of Open Access Journals (Sweden)

    Feng Dong

    2014-01-01

    Full Text Available Aim. We aimed to investigate and evaluate the preventive activity of puerarin on the ovalbumin-induced asthma rat model. Materials and Methods. Male Wistar rats were sensitized intraperitoneally on days 0, 7, and 14 and challenged to ovalbumin intratracheally on day 21. Groups of sensitized rats were treated randomly either with placebo, puerarin, dexamethasone, or puerarin combined with dexamethasone, from days 15 to 20. Inflammatory markers, including cell counts in bronchoalveolar lavage fluid (BALF, inflammatory cytokines, histopathology, and coagulation parameters, such as coagulation tests and the activity of coagulation factors, were analyzed. Results. Puerarin significantly inhibited the recruitment of inflammatory cells in BALF and lung tissue. At the same time, the release of IL-4, IL-10, and IFN-γ in serum and the expression of mRNAs in lung tissue homogenate were changed by puerarin. Administration of puerarin also effectively rectified the coagulation disorder in asthmatic rats, such as prothrombin time (PT (P<0.01, thrombin time (TT (P<0.05, fibrinogen (FIB (P<0.01,the activity of factor II (FII (P<0.01, the activity of factor V (FV (P<0.05, the activity of factor VII (FVII (P<0.05, the activity of factor X (FX (P<0.05, the activity of factor VIII (FVIII (P<0.01, the activity of factor IX (FIX (P<0.05, and the activity of factor XII (FXII (P<0.05. Conclusions. Our results provide a clue that puerarin was useful for the preventive of allergic airway disease in rodents.

  2. Pregabalin attenuates place escape/avoidance behavior in a rat model of spinal cord injury.

    Science.gov (United States)

    Baastrup, Cathrine; Jensen, Troels Staehelin; Finnerup, Nanna Brix

    2011-01-25

    Spinal cord injury (SCI) pain in humans is difficult to treat, and the lack of valid methods to measure behavior comparable to the complex human pain experience preclinically represents an important obstacle to finding better treatments for this type of central pain. The place escape/avoidance paradigm (PEAP) relies on the active choice of an animal between its natural preference for a dark environment or pain relief, and it has been suggested to measure the affective-motivational component of pain. We have modified the method to a T10 spinal cord contusion model (SCC) of at-level central neuropathic pain in Sprague-Dawley rats. In order to demonstrate sensitivity to change in escape/avoidance behavior and thus the applicability of the PEAP method to predict drug efficacy, we investigated the effect of pregabalin (30 mg/kg) treatment in a randomized design. SCC animals displayed increased escape/avoidance behavior postinjury, indicating at-level mechanical hypersensitivity. Second, we found no correlation between state anxiety levels in SCC animals (elevated plus maze) and PEAP behavior, suggesting that the PEAP measurement is not biased by differences in anxiety levels. Third, we demonstrated a decrease in escape/avoidance behavior in response to treatment with the analgesic drug pregabalin. Thus, the PEAP may be applicable as a surrogate correlate of human pain. In conclusion, the primary finding in this study was a sensitivity to change in escape/avoidance behavior induced by pharmacological modulation with analgesics, supporting the use of the PEAP as a central outcome measure in preclinical SCI pain research. PMID:21070753

  3. Field-scale model for the natural attenuation of uranium at the Hanford 300 area using high performance computing

    Energy Technology Data Exchange (ETDEWEB)

    Lichtner, Peter C [Los Alamos National Laboratory; Hammond, Glenn E [PNNL

    2009-01-01

    Three-dimensional reactive flow and transport simulations are carried out to better understand the persistence of uranium [U(VI)] at the Hanford 300 Area bordering the Columbia River. The massively parallel code PFLOTRAN developed under a DOE SciDAC-2 project is employed in the simulations. The calculations were carried out on 4096 processor cores on ORNL's Jaguar XT4 & 5 Cray supercomputers with run times on the order of 6 hours, equivalent to several years if performed on a single processor with sufficient memory. A new conceptual model is presented for understanding present-day and future attenuation rates of U(VI) at the 300 Area site. Unique to the conceptual model is the recognition of three distinct phases in the evolution of the site corresponding to: (I) initial emplacement of waste; (II) present-day conditions of slow leaching of U(VI) from the Hanford sediments; and (III) the complete removal of non-labile U(VI) from the source region. This work focuses on Phase II. Both labile and non-labile forms of U(VI) are included in the model as sorbed and mineralized forms of U(VI), respectively. The non-labile form plays an important role in providing a long-term source of U(VI) as it slowly leaches out of the Hanford sediment. Rapid fluctuations in the Columbia River stage on hourly, weekly and seasonal time scales are found to' playa major role in determining the migration behavior of U(VI). The calculations demonstrate that U(VI) is released into the Columbia River at a highly fluctuating rate in a ratchet-like behavior with nonzero U(VI) flux occurring only during flow from contaminated sediment into the river. The cumulative flux, however, is found to increase approximately linearly with time. The flow rate and U(VI) flux into the Columbia River predicted by the model is highly sensitive to the value used in the conductance boundary condition at the river-sediment interface. By fitting the conductance to the measured piezometric head at well 399

  4. Low-intensity aerobic exercise training attenuates airway inflammation and remodeling in a rat model of steroid-resistant asthma

    Institute of Scientific and Technical Information of China (English)

    Qin Qingwu; Chen Xi; Feng Juntao; Qin Ling; Hu Chengping

    2014-01-01

    were less sensitive to DXM treatment.Anti-HMGB1 treatment attenuated airway hyperresponsiveness,inflammation,and remodeling in SRA rats to a certain extent and was accompanied by lower levels of IL-17 ((369.2±126.7) vs.(780.5±261.7) pg/ml in control SRA rats) in BALF (P <0.05).Low-intensity aerobic exercise training decreased the expression of both HMGB1 ((14.1±2.9) vs.(21.2±4.5) ng/ml in control SRA rats) and IL-17 ((545.3±148.6) vs.(780.5±261.7) pg/ml in control SRA rats) in BALF (all P <0.05) and was accompanied by improved airway hyperresponsiveness,inflammation,and remodeling in SRA rats (all P <0.05).Conclusions Low-intensity aerobic exercise training attenuated airway hyperresponsiveness,inflammation,and remodeling in a rat model of SPA.Decreased HMGB1 and IL-17 levels in BALF by aerobic exercise training at least partly contributed to the improvements of SPA.

  5. Reducing C-terminal-truncated alpha-synuclein by immunotherapy attenuates neurodegeneration and propagation in Parkinson's disease-like models.

    Science.gov (United States)

    Games, Dora; Valera, Elvira; Spencer, Brian; Rockenstein, Edward; Mante, Michael; Adame, Anthony; Patrick, Christina; Ubhi, Kiren; Nuber, Silke; Sacayon, Patricia; Zago, Wagner; Seubert, Peter; Barbour, Robin; Schenk, Dale; Masliah, Eliezer

    2014-07-01

    Parkinson's disease (PD) and dementia with Lewy bodies (DLB) are common neurodegenerative disorders of the aging population, characterized by progressive and abnormal accumulation of α-synuclein (α-syn). Recent studies have shown that C-terminus (CT) truncation and propagation of α-syn play a role in the pathogenesis of PD/DLB. Therefore, we explored the effect of passive immunization against the CT of α-syn in the mThy1-α-syn transgenic (tg) mouse model, which resembles the striato-nigral and motor deficits of PD. Mice were immunized with the new monoclonal antibodies 1H7, 5C1, or 5D12, all directed against the CT of α-syn. CT α-syn antibodies attenuated synaptic and axonal pathology, reduced the accumulation of CT-truncated α-syn (CT-α-syn) in axons, rescued the loss of tyrosine hydroxylase fibers in striatum, and improved motor and memory deficits. Among them, 1H7 and 5C1 were most effective at decreasing levels of CT-α-syn and higher-molecular-weight aggregates. Furthermore, in vitro studies showed that preincubation of recombinant α-syn with 1H7 and 5C1 prevented CT cleavage of α-syn. In a cell-based system, CT antibodies reduced cell-to-cell propagation of full-length α-syn, but not of the CT-α-syn that lacked the 118-126 aa recognition site needed for antibody binding. Furthermore, the results obtained after lentiviral expression of α-syn suggest that antibodies might be blocking the extracellular truncation of α-syn by calpain-1. Together, these results demonstrate that antibodies against the CT of α-syn reduce levels of CT-truncated fragments of the protein and its propagation, thus ameliorating PD-like pathology and improving behavioral and motor functions in a mouse model of this disease. PMID:25009275

  6. Maximum likelihood estimation of the attenuated ultrasound pulse

    DEFF Research Database (Denmark)

    Rasmussen, Klaus Bolding

    1994-01-01

    The attenuated ultrasound pulse is divided into two parts: a stationary basic pulse and a nonstationary attenuation pulse. A standard ARMA model is used for the basic pulse, and a nonstandard ARMA model is derived for the attenuation pulse. The maximum likelihood estimator of the attenuated ultra...

  7. Valproate Attenuates Nitroglycerin-Induced Trigeminovascular Activation by Preserving Mitochondrial Function in a Rat Model of Migraine

    Science.gov (United States)

    Li, Ruxian; Liu, Yushuang; Chen, Nan; Zhang, Yitong; Song, Ge; Zhang, Zhongling

    2016-01-01

    Background Migraine is a chronic disease that interferes with life quality and work productivity. Valproate shows protective effects against migraine, yet the underlying mechanisms are unclear. This study aimed to evaluate the potential effect of valproate on migraine using a rat model of nitroglycerin-induced trigeminovascular activation, as well as to explore the underlying mechanism. Material/Methods Intraperitoneal injection of nitroglycerin was conducted to induce trigeminovascular activation in rats. To explore the protective effect of valproate, a low dose (100 mg/kg) or a high dose (200 mg/kg) of valproate was intraperitoneally injected into rats, and then the levels of 5-hydroxytryptamine and nitric oxide in the peripheral blood were examined. The mtDNA copy number and the protein levels of peroxisome proliferator-activated receptor-γ coactivator 1α, mitochondrial transcription factor A, and peroxisome proliferator-activated receptor-γ in the spinal trigeminal nucleus were detected to evaluate the biogenesis of mitochondria. The mitochondrial energy metabolism was determined by the mitochondrial membrane potential and the levels of adenosine triphosphate, cytochrome C oxidase, and reactive oxygen species. Results Valproate attenuated nitroglycerin-induced trigeminovascular activation in rats, with reduced scratching behavior and restored 5-hydroxytryptamine and nitric oxide levels. Moreover, the mitochondrial energy metabolism and the biogenesis of mitochondria were preserved by valproate in nitroglycerin-treated rats. Conclusions The protective effect of valproate against migraine may be achieved through the modulation of mitochondrial biogenesis and function. Our study provides evidence for the potential use of valproate in the treatment of migraine. PMID:27618395

  8. Nitrogen attenuation in the Connecticut River, northeastern USA; a comparison of mass balance and N2 production modeling approaches

    Science.gov (United States)

    Smith, T.E.; Laursen, A.E.; Deacon, J.R.

    2008-01-01

    Two methods were used to measure in-stream nitrogen loss in the Connecticut River during studies conducted in April and August 2005. A mass balance on nitrogen inputs and output for two study reaches (55 and 66 km), at spring high flow and at summer low flow, was computed on the basis of total nitrogen concentrations and measured river discharges in the Connecticut River and its tributaries. In a 10.3 km subreach of the northern 66 km reach, concentrations of dissolved N2 were also measured during summer low flow and compared to modeled N2 concentrations (based on temperature and atmospheric gas exchange rates) to determine the measured "excess" N2 that indicates denitrification. Mass balance results showed no in-stream nitrogen loss in either reach during April 2005, and no nitrogen loss in the southern 55 km study reach during August 2005. In the northern 66 km reach during August 2005, however, nitrogen output was 18% less than the total nitrogen inputs to the reach. N2 sampling results gave an estimated rate of N2 production that would remove 3.3% of the nitrogen load in the river over the 10.3 km northern sub-reach. The nitrogen losses measured in the northern reach in August 2005 may represent an approximate upper limit for nitrogen attenuation in the Connecticut River because denitrification processes are most active during warm summer temperatures and because the study was performed during the annual low-flow period when total nitrogen loads are small. ?? 2008 Springer Science+Business Media B.V.

  9. Deliberate attenuation of chikungunya virus by adaptation to heparan sulfate-dependent infectivity: a model for rational arboviral vaccine design.

    Science.gov (United States)

    Gardner, Christina L; Hritz, Jozef; Sun, Chengqun; Vanlandingham, Dana L; Song, Timothy Y; Ghedin, Elodie; Higgs, Stephen; Klimstra, William B; Ryman, Kate D

    2014-02-01

    Mosquito-borne chikungunya virus (CHIKV) is a positive-sense, single-stranded RNA virus from the genus Alphavirus, family Togaviridae, which causes fever, rash and severe persistent polyarthralgia in humans. Since there are currently no FDA licensed vaccines or antiviral therapies for CHIKV, the development of vaccine candidates is of critical importance. Historically, live-attenuated vaccines (LAVs) for protection against arthropod-borne viruses have been created by blind cell culture passage leading to attenuation of disease, while maintaining immunogenicity. Attenuation may occur via multiple mechanisms. However, all examined arbovirus LAVs have in common the acquisition of positively charged amino acid substitutions in cell-surface attachment proteins that render virus infection partially dependent upon heparan sulfate (HS), a ubiquitously expressed sulfated polysaccharide, and appear to attenuate by retarding dissemination of virus particles in vivo. We previously reported that, like other wild-type Old World alphaviruses, CHIKV strain, La Réunion, (CHIKV-LR), does not depend upon HS for infectivity. To deliberately identify CHIKV attachment protein mutations that could be combined with other attenuating processes in a LAV candidate, we passaged CHIKV-LR on evolutionarily divergent cell-types. A panel of single amino acid substitutions was identified in the E2 glycoprotein of passaged virus populations that were predicted to increase electrostatic potential. Each of these substitutions was made in the CHIKV-LR cDNA clone and comparisons of the mutant viruses revealed surface exposure of the mutated residue on the spike and sensitivity to competition with the HS analog, heparin, to be primary correlates of attenuation in vivo. Furthermore, we have identified a mutation at E2 position 79 as a promising candidate for inclusion in a CHIKV LAV.

  10. Silymarin attenuated hepatic steatosis through regulation of lipid metabolism and oxidative stress in a mouse model of nonalcoholic fatty liver disease (NAFLD)

    OpenAIRE

    Ni, Xunjun; Wang, Haiyan

    2016-01-01

    Silymarin, which derived from the milk thistle plant (silybum marianum), has been used for centuries as a natural remedy for diseases of the liver and biliary tract. Considering the therapeutic potential to liver disease, we tested efficacy of silymarin on hepatic steatosis with a high fat diet (HFD)-induced mouse model of non-alcoholic fatty liver disease (NAFLD), and investigated possible effects on lipid metabolic pathways. In our study, silymarin could attenuate the hepatic steatosis, whi...

  11. A constant stress-drop model for producing broadband synthetic seismograms: Comparison with the next generation attenuation relations

    Science.gov (United States)

    Frankel, A.

    2009-01-01

    Broadband (0.1-20 Hz) synthetic seismograms for finite-fault sources were produced for a model where stress drop is constant with seismic moment to see if they can match the magnitude dependence and distance decay of response spectral amplitudes found in the Next Generation Attenuation (NGA) relations recently developed from strong-motion data of crustal earthquakes in tectonically active regions. The broadband synthetics were constructed for earthquakes of M 5.5, 6.5, and 7.5 by combining deterministic synthetics for plane-layered models at low frequencies with stochastic synthetics at high frequencies. The stochastic portion used a source model where the Brune stress drop of 100 bars is constant with seismic moment. The deterministic synthetics were calculated using an average slip velocity, and hence, dynamic stress drop, on the fault that is uniform with magnitude. One novel aspect of this procedure is that the transition frequency between the deterministic and stochastic portions varied with magnitude, so that the transition frequency is inversely related to the rise time of slip on the fault. The spectral accelerations at 0.2, 1.0, and 3.0 sec periods from the synthetics generally agreed with those from the set of NGA relations for M 5.5-7.5 for distances of 2-100 km. At distances of 100-200 km some of the NGA relations for 0.2 sec spectral acceleration were substantially larger than the values of the synthetics for M 7.5 and M 6.5 earthquakes because these relations do not have a term accounting for Q. At 3 and 5 sec periods, the synthetics for M 7.5 earthquakes generally had larger spectral accelerations than the NGA relations, although there was large scatter in the results from the synthetics. The synthetics showed a sag in response spectra at close-in distances for M 5.5 between 0.3 and 0.7 sec that is not predicted from the NGA relations.

  12. Combined treatment with olmesartan medoxomil and amlodipine besylate attenuates atherosclerotic lesion progression in a model of advanced atherosclerosis

    Directory of Open Access Journals (Sweden)

    Sievers P

    2015-07-01

    Full Text Available Philipp Sievers,1 Lorenz Uhlmann,2 Sevil Korkmaz-Icöz,3 Christian Fastner,1 Florian Bea,1 Erwin Blessing,1 Hugo A Katus,1 Michael R Preusch11Department of Internal Medicine III, 2Institute of Medical Biometry and Informatics, 3Department of Cardiac Surgery, University of Heidelberg, Heidelberg, GermanyIntroduction: Besides their blood pressure-lowering effects, olmesartan medoxomil and amlodipine besylate exhibit additional anti-inflammatory mechanisms in atherosclerosic disease. Most of the studies investigating the effects of atherosclerosis focused on early atherosclerotic lesions, whereas lesions in human disease, at the time when medical treatment is started, are already well established. Therefore, we set up a model of advanced atherosclerosis and investigated the effects of olmesartan medoxomil, amlodipine besylate, and the combination of both on atherosclerotic lesion size and lesion composition.Materials and methods: Olmesartan medoxomil (1 mg/kg/day, amlodipine besylate (1.5 mg/kg/day, and the combination of both was added to chow and was fed to apolipoprotein E-deficient (ApoE-/- mice at 25 weeks of age. Mice were sacrificed after 25 weeks of drug administration and perfused with formalin. Innominate arteries were dissected out and paraffin embedded. Serial sections were generated, and lesion sizes and their composition – such as minimal thickness of the fibrous cap, size of the necrotic core, and presence of calcification – were analyzed. Electrophoretic mobility shift assays were used to detect DNA-binding activity of the transcription factor nuclear factor-kappa B (NF-κB in aortic tissue.Results: Treatment with the combination of olmesartan medoxomil and amlodipine besylate led to a significant reduction in atherosclerotic lesion size in ApoE-/- mice (olmesartan medoxomil/amlodipine besylate: 122,277±6,795 µm2, number [n]=14; versus control: 177,502±10,814 µm2, n=9; P<0.001. Treatment with amlodipine besylate (n=5 alone

  13. Atrial natriuretic peptide attenuates inflammatory responses on oleic acid-induced acute lung injury model in rats

    Institute of Scientific and Technical Information of China (English)

    ZHU Yao-bin; ZHANG Yan-bo; LIU Dong-hai; LI Xiao-feng; LIU Ai-jun; FAN Xiang-ming; QIAO Chen-hui

    2013-01-01

    Background An inflammatory response leading to organ dysfunction and failure continues to be a major problem after injury in many clinical conditions such as sepsis,severe burns,and trauma.It is increasingly recognized that atrial natriuretic peptide (ANP) possesses a broad range of biological activities,including effects on endothelial function and inflammation.A recent study has revealed that ANP exerts anti-inflammatory effects.In this study we tested the effects of human ANP (hANP) on lung injury in a model of oleic acid (OA)-induced acute lung injury (ALl) in rats.Methods Rats were randomly assigned to three groups (n=6 in each group).Rats in the control group received a 0.9% solution of NaCl (1 ml.kg1.h-1) by continuous intravenous infusion,after 30 minutes a 0.9% solution of NaCl (1 ml/kg) was injected intravenously,and then the 0.9% NaCl infusion was restarted.Rats in the ALl group received a 0.9% NaCl solution (1 ml·kg-1·h-1) intravenous infusion,after 30 minutes OA was injected intravenously (0.1 ml/kg),and then the 0.9% NaCl infusion was restarted.Rats in the hANP-treated ALI group received a hANP (0.1μg·kg-1·min-1) infusion,after 30 minutes OA was injected intravenously (0.1 ml/kg),and then the hANP infusion was restarted.The anti-inflammation effects of hANP were evaluated by histological examination and determination of serum cytokine levels.Results Serum intedeukin (IL)-1β,IL-6,IL-10 and tumor necrosis factor (TNF) α were increased in the ALI group at six hours.The levels of all factors were significantly lower in the hANP treated rats (P <0.005).Similarly,levels of IL-1β,IL-6,IL-10 and TNF-α were higher in the lung tissue in the ALI group at six hours.hANP treatment significantly reduced the levels of these factors in the lungs (P <0.005).Histological examination revealed marked reduction in interstitial congestion,edema,and inflammation.Conclusion hANP can attenuate inflammation in an OA-induced lung injury in rat model.

  14. MicroRNA-155 Deficiency Attenuates Liver Steatosis and Fibrosis without Reducing Inflammation in a Mouse Model of Steatohepatitis.

    Directory of Open Access Journals (Sweden)

    Timea Csak

    Full Text Available MicroRNAs (miRs regulate hepatic steatosis, inflammation and fibrosis. Fibrosis is the consequence of chronic tissue damage and inflammation. We hypothesized that deficiency of miR-155, a master regulator of inflammation, attenuates steatohepatitis and fibrosis.Wild type (WT and miR-155-deficient (KO mice were fed methionine-choline-deficient (MCD or -supplemented (MCS control diet for 5 weeks. Liver injury, inflammation, steatosis and fibrosis were assessed.MCD diet resulted in steatohepatitis and increased miR-155 expression in total liver, hepatocytes and Kupffer cells. Steatosis and expression of genes involved in fatty acid metabolism were attenuated in miR-155 KO mice after MCD feeding. In contrast, miR-155 deficiency failed to attenuate inflammatory cell infiltration, nuclear factor κ beta (NF-κB activation and enhanced the expression of the pro-inflammatory cytokines tumor necrosis factor alpha (TNFα and monocyte chemoattractant protein-1 (MCP1 in MCD diet-fed mice. We found a significant attenuation of apoptosis (cleaved caspase-3 and reduction in collagen and α smooth muscle actin (αSMA levels in miR-155 KO mice compared to WTs on MCD diet. In addition, we found attenuation of platelet derived growth factor (PDGF, a pro-fibrotic cytokine; SMAD family member 3 (Smad3, a protein involved in transforming growth factor-β (TGFβ signal transduction and vimentin, a mesenchymal marker and indirect indicator of epithelial-to-mesenchymal transition (EMT in miR-155 KO mice. Nuclear binding of CCAAT enhancer binding protein β (C/EBPβ a miR-155 target involved in EMT was significantly increased in miR-155 KO compared to WT mice.Our novel data demonstrate that miR-155 deficiency can reduce steatosis and fibrosis without decreasing inflammation in steatohepatitis.

  15. An attempt to model the relationship between MMI attenuation and engineering ground-motion parameters using artificial neural networks and genetic algorithms

    Directory of Open Access Journals (Sweden)

    G-A. Tselentis

    2010-12-01

    Full Text Available Complex application domains involve difficult pattern classification problems. This paper introduces a model of MMI attenuation and its dependence on engineering ground motion parameters based on artificial neural networks (ANNs and genetic algorithms (GAs. The ultimate goal of this investigation is to evaluate the target-region applicability of ground-motion attenuation relations developed for a host region based on training an ANN using the seismic patterns of the host region. This ANN learning is based on supervised learning using existing data from past earthquakes. The combination of these two learning procedures (that is, GA and ANN allows us to introduce a new method for pattern recognition in the context of seismological applications. The performance of this new GA-ANN regression method has been evaluated using a Greek seismological database with satisfactory results.

  16. Development of prophylactic recombinant HPV58-attenuated Shigeila live vector vaccine and evaluation of its protective efficacy and immunogenicity in the guinea pig keratoconjunctivitis model

    Institute of Scientific and Technical Information of China (English)

    Wensheng Li; Hongli Liu; Xiaofeng Yang; Jin Zheng; Yili Wang; Lusheng Si

    2009-01-01

    To develop a prophylactic recombinant HPV58L1-attenuated Shigella live vector vaccine and evaluate its protective efficacy and immunogenicity in the guinea pig keratoconjunctivitis model, the HPV58L1 gene was cloned into vector pUCmt, and then subcloned into the suicide vector pCVD442. The recombinant plasmid pCVD442-HPV58L1 was introduced into attenuated Shigella (sf301:△virG) with the helper plasmid PRK2013 by filter mating. The positive colonies were harvested and confirmed by polymerase chain reaction. The expression of the HPV58L1 protein with a molecu-lar weight of 60 kDa was confirmed by western blot. The ability of the interested protein to self-assemble into virus-like particles was identified by transmission electron microscope, and murine erythrocyte hemagglu-tination assay. The guinea pig keratoconjunctivitis model was used to evaluate the protective efficacy and immunogenicity of the vaccine. Animal experiments showed that there was no keratoconjunctivitis occurred in the immunized group (HPV58-attenuated Shigella), and the serum levels of anti-HPV58L1-IgG and -IgA were obviously increased (P0.05). Enzyme-linked immunosorbent spot assay showed that HPV58L1-specific IgA-antibody-secreting cells (ASC) and IgG-ASC of spleen and lymph nodes were also obviously increased (P<0.01). In this study, a recombi-nant HPV58L1-attenuated Shigella live vector vaccine was successfully constructed, and it could induce strong humoral immune responses in the immunized animals, and induce protective antibody production.

  17. Inhibition of Src kinase activity attenuates amyloid associated microgliosis in a murine model of Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Dhawan Gunjan

    2012-07-01

    Full Text Available Abstract Background Microglial activation is an important histologic characteristic of the pathology of Alzheimer’s disease (AD. One hypothesis is that amyloid beta (Aβ peptide serves as a specific stimulus for tyrosine kinase-based microglial activation leading to pro-inflammatory changes that contribute to disease. Therefore, inhibiting Aβ stimulation of microglia may prove to be an important therapeutic strategy for AD. Methods Primary murine microglia cultures and the murine microglia cell line, BV2, were used for stimulation with fibrillar Aβ1-42. The non-receptor tyrosine kinase inhibitor, dasatinib, was used to treat the cells to determine whether Src family kinase activity was required for the Aβ stimulated signaling response and subsequent increase in TNFα secretion using Western blot analysis and enzyme-linked immunosorbent assay (ELISA, respectively. A histologic longitudinal analysis was performed using an AD transgenic mouse model, APP/PS1, to determine an age at which microglial protein tyrosine kinase levels increased in order to administer dasatinib via mini osmotic pump diffusion. Effects of dasatinib administration on microglial and astroglial activation, protein phosphotyrosine levels, active Src kinase levels, Aβ plaque deposition, and spatial working memory were assessed via immunohistochemistry, Western blot, and T maze analysis. Results Aβ fibrils stimulated primary murine microglia via a tyrosine kinase pathway involving Src kinase that was attenuated by dasatinib. Dasatinib administration to APP/PS1 mice decreased protein phosphotyrosine, active Src, reactive microglia, and TNFα levels in the hippocampus and temporal cortex. The drug had no effect on GFAP levels, Aβ plaque load, or the related tyrosine kinase, Lyn. These anti-inflammatory changes correlated with improved performance on the T maze test in dasatinib infused animals compared to control animals. Conclusions These data suggest that amyloid

  18. K(Ca3.1 channel-blockade attenuates airway pathophysiology in a sheep model of chronic asthma.

    Directory of Open Access Journals (Sweden)

    Joanne Van Der Velden

    Full Text Available BACKGROUND: The Ca(2+-activated K(+ channel K(Ca3.1 is expressed in several structural and inflammatory airway cell types and is proposed to play an important role in the pathophysiology of asthma. The aim of the current study was to determine whether inhibition of K(Ca3.1 modifies experimental asthma in sheep. METHODOLOGY AND PRINCIPAL FINDINGS: Atopic sheep were administered either 30 mg/kg Senicapoc (ICA-17073, a selective inhibitor of the K(Ca3.1-channel, or vehicle alone (0.5% methylcellulose twice daily (orally. Both groups received fortnightly aerosol challenges with house dust mite allergen for fourteen weeks. A separate sheep group received no allergen challenges or drug treatment. In the vehicle-control group, twelve weeks of allergen challenges resulted in a 60±19% increase in resting airway resistance, and this was completely attenuated by treatment with Senicapoc (0.25±12%; n = 10, P = 0.0147. The vehicle-control group had a peak-early phase increase in lung resistance of 82±21%, and this was reduced by 58% with Senicapoc treatment (24±14%; n = 10, P = 0.0288. Senicapoc-treated sheep also demonstrated reduced airway hyperresponsiveness, requiring a significantly higher dose of carbachol to increase resistance by 100% compared to allergen-challenged vehicle-control sheep (20±5 vs. 52±18 breath-units of carbachol; n = 10, P = 0.0340. Senicapoc also significantly reduced eosinophil numbers in bronchoalveolar lavage taken 48 hours post-allergen challenge, and reduced vascular remodelling. CONCLUSIONS: These findings suggest that K(Ca3.1-activity contributes to allergen-induced airway responses, inflammation and vascular remodelling in a sheep model of asthma, and that inhibition of K(Ca3.1 may be an effective strategy for blocking allergen-induced airway inflammation and hyperresponsiveness in humans.

  19. Attenuation in silica-based optical fibers

    DEFF Research Database (Denmark)

    Wandel, Marie Emilie

    2006-01-01

    absorption peaks in order to investigate the cause of an unusual high attenuation in a series of transmission fibers. Strong indications point to Ni2+ in octahedral coordination as being the cause of the high attenuation. The attenuation of fibers having a high core refractive index is analyzed and the cause...... well as the viscosity profile a lower attenuation of high index fibers can be obtained. The design of dispersion compensating fibers using the super mode approach is described, the object being to design dispersion compensating fibers for dispersion compensating fiber modules having a low attenuation......, described by a high figure of merit. The major trade offs encountered when designing dispersion compensating fibers with high figure of merit are to obtain a very negative dispersion, low attenuation and low micro bend loss at the same time. The model for predicting the attenuation of high index fibers is...

  20. Glyoxalase-1 overexpression reduces endothelial dysfunction and attenuates early renal impairment in a rat model of diabetes

    DEFF Research Database (Denmark)

    Brouwers, Olaf; Niessen, Petra M G; Miyata, Toshio;

    2014-01-01

    of streptozotocin. Mesenteric arteries were isolated to study ex vivo vascular reactivity with a wire myograph and kidneys were processed for histological examination. Glycation was determined by mass spectrometry and immunohistochemistry. Markers for inflammation, endothelium dysfunction and renal dysfunction were...... podocyte number and diabetes-induced elevation of urinary markers albumin, osteopontin, kidney-inflammation-molecule-1 and nephrin) were attenuated by Glo1 overexpression. In line with this, downregulation of Glo1 in cultured endothelial cells resulted in increased expression of inflammation...

  1. MicroRNA-155 Deficiency Attenuates Liver Steatosis and Fibrosis without Reducing Inflammation in a Mouse Model of Steatohepatitis

    OpenAIRE

    Csak, Timea; Bala, Shashi; Lippai, Dora; Kodys, Karen; Catalano, Donna; Iracheta-Vellve, Arvin; Szabo, Gyongyi

    2015-01-01

    Background & Aim MicroRNAs (miRs) regulate hepatic steatosis, inflammation and fibrosis. Fibrosis is the consequence of chronic tissue damage and inflammation. We hypothesized that deficiency of miR-155, a master regulator of inflammation, attenuates steatohepatitis and fibrosis. Methods Wild type (WT) and miR-155-deficient (KO) mice were fed methionine-choline-deficient (MCD) or -supplemented (MCS) control diet for 5 weeks. Liver injury, inflammation, steatosis and fibrosis were assessed. Re...

  2. Modeling and Forecasting of Depletion of Additives in Car Engine Oils Using Attenuated Total Reflectance Fast Transform Infrared Spectroscopy

    OpenAIRE

    Ronald Nguele; Hikmat Said Al-Salim; Khalid Mohammad

    2014-01-01

    On average, additives make up to 7% of a typical lubricant base. Commonly, they are blended with lube oils to enhance specific features thereby improving their qualities. Ultimately, additives participate in the performance of car engine oils. Using an analytical tool, attenuated total reflectance fast transform infrared spectroscopy, various grades of car engine oils, at different mileages, were analyzed. Sulfate oxidation and wear were found to trigger chemical processes which, in the long ...

  3. Joint Inflammation and Early Degeneration Induced by High-Force Reaching Are Attenuated by Ibuprofen in an Animal Model of Work-Related Musculoskeletal Disorder

    Directory of Open Access Journals (Sweden)

    Jeffrey B. Driban

    2011-01-01

    Full Text Available We used our voluntary rat model of reaching and grasping to study the effect of performing a high-repetition and high-force (HRHF task for 12 weeks on wrist joints. We also studied the effectiveness of ibuprofen, administered in the last 8 weeks, in attenuating HRHF-induced changes in these joints. With HRHF task performance, ED1+ and COX2+ cells were present in subchondral radius, carpal bones and synovium; IL-1alpha and TNF-alpha increased in distal radius/ulna/carpal bones; chondrocytes stained with Terminal deoxynucleotidyl Transferase- (TDT- mediated dUTP-biotin nick end-labeling (TUNEL increased in wrist articular cartilages; superficial structural changes (e.g., pannus and reduced proteoglycan staining were observed in wrist articular cartilages. These changes were not present in normal controls or ibuprofen treated rats, although IL-1alpha was increased in reach limbs of trained controls. HRHF-induced increases in serum C1,2C (a biomarker of collagen I and II degradation, and the ratio of collagen degradation to synthesis (C1,2C/CPII; the latter a biomarker of collage type II synthesis were also attenuated by ibuprofen. Thus, ibuprofen treatment was effective in attenuating HRHF-induced inflammation and early articular cartilage degeneration.

  4. A new model for the vertical spectral diffuse attenuation coefficient of downwelling irradiance in turbid coastal waters: validation with in situ measurements.

    Science.gov (United States)

    Simon, Arthi; Shanmugam, Palanisamy

    2013-12-01

    The vertical spectral diffuse attenuation coefficient of Kd is an important optical property related to the penetration and availability of light underwater, which is of fundamental interest in studies of ocean physics and biology. Models developed in the recent decades were mainly based on theoretical analyses and numerical (radiative transfer) simulations to estimate this property in optically deep waters, thus leaving inadequate knowledge of its variability at multiple depths and wavelengths, covering a wide range of solar incident geometry, in turbid coastal waters. In the present study, a new model is developed to quantify the vertical, spatial and temporal variability of K(d) at multiple wavelengths and to quantify its dependence with respect to solar incident geometry under differing sky conditions. Thus, the new model is derived as a function of inherent optical properties (IOPs - absorption a and backscattering b(b)), solar zenith angle and depth parameters. The model results are rigorously evaluated using time-series and discrete in situ data from clear and turbid coastal waters. The K(d) values derived from the new model are found to agree with measured data within the mean relative error 0.02~6.24% and R² 0.94~0.99. By contrast, the existing models have large errors when applied to the same data sets. Statistical results of the new model for the vertical spectral distribution of K(d) in clear oceanic waters (for different solar zenith and in-water conditions) are also good when compared to those of the existing models. These results suggest that the new model can provide an improved interpretation about the variation of the vertical spectral diffuse attenuation coefficient of downwelling irradiance, which will have important implications for ocean physics, biogeochemical cycles and underwater applications in both relatively clear and turbid coastal waters. PMID:24514558

  5. Imaging Rayleigh wave attenuation with USArray

    Science.gov (United States)

    Bao, Xueyang; Dalton, Colleen A.; Jin, Ge; Gaherty, James B.; Shen, Yang

    2016-07-01

    The EarthScope USArray provides an opportunity to obtain detailed images of the continental upper mantle at an unprecedented scale. The majority of mantle models derived from USArray data to date contain spatial variations in seismic-wave speed; however, in many cases these data sets do not by themselves allow a non-unique interpretation. Joint interpretation of seismic attenuation and velocity models can improve upon the interpretations based only on velocity and provide important constraints on the temperature, composition, melt content, and volatile content of the mantle. The surface wave amplitudes that constrain upper-mantle attenuation are sensitive to factors in addition to attenuation, including the earthquake source excitation, focusing and defocusing by elastic structure, and local site amplification. Because of the difficulty of isolating attenuation from these other factors, little is known about the attenuation structure of the North American upper mantle. In this study, Rayleigh wave traveltime and amplitude in the period range 25-100 s are measured using an interstation cross-correlation technique, which takes advantage of waveform similarity at nearby stations. Several estimates of Rayleigh wave attenuation and site amplification are generated at each period, using different approaches to separate the effects of attenuation and local site amplification on amplitude. It is assumed that focusing and defocusing effects can be described by the Laplacian of the traveltime field. All approaches identify the same large-scale patterns in attenuation, including areas where the attenuation values are likely contaminated by unmodelled focusing and defocusing effects. Regionally averaged attenuation maps are constructed after removal of the contaminated attenuation values, and the variations in intrinsic shear attenuation that are suggested by these Rayleigh wave attenuation maps are explored.

  6. Mesenchymal Stem Cell Attenuates Neutrophil-predominant Inflammation and Acute Lung Injury in an In Vivo Rat Model of Ventilator-induced Lung Injury

    Directory of Open Access Journals (Sweden)

    Tian-Shun Lai

    2015-01-01

    Full Text Available Background: Subsequent neutrophil (polymorphonuclear neutrophil [PMN]-predominant inflammatory response is a predominant feature of ventilator-induced lung injury (VILI, and mesenchymal stem cell (MSC can improve mice survival model of endotoxin-induced acute lung injury, reduce lung impairs, and enhance the repair of VILI. However, whether MSC could attenuate PMN-predominant inflammatory in the VILI is still unknown. This study aimed to test whether MSC intervention could attenuate the PMN-predominate inflammatory in the mechanical VILI. Methods: Sprague-Dawley rats were ventilated for 2 hours with large tidal volume (20 mL/kg. MSCs were given before or after ventilation. The inflammatory chemokines and gas exchange were observed and compared dynamically until 4 hours after ventilation, and pulmonary pathological change and activation of PMN were observed and compared 4 hours after ventilation. Results: Mechanical ventilation (MV caused significant lung injury reflected by increasing in PMN pulmonary sequestration, inflammatory chemokines (tumor necrosis factor-alpha, interleukin-6 and macrophage inflammatory protein 2 in the bronchoalveolar lavage fluid, and injury score of the lung tissue. These changes were accompanied with excessive PMN activation which reflected by increases in PMN elastase activity, production of radical oxygen series. MSC intervention especially pretreatment attenuated subsequent lung injury, systemic inflammation response and PMN pulmonary sequestration and excessive PMN activation initiated by injurious ventilation. Conclusions: MV causes profound lung injury and PMN-predominate inflammatory responses. The protection effect of MSC in the VILI rat model is related to the suppression of the PMN activation.

  7. Mesenchymal Stem Cell Attenuates Neutrophil-predominant Inflammation and Acute Lung Injury in an In Vivo Rat Model of Ventilator-induced Lung Injury

    Institute of Scientific and Technical Information of China (English)

    Tian-Shun Lai; Zhi-Hong Wang; Shao-Xi Cai

    2015-01-01

    Background:Subsequent neutrophil (polymorphonuclear neutrophil [PMN])-predominant inflammatory response is a predominant feature of ventilator-induced lung injury (VILI),and mesenchymal stem cell (MSC) can improve mice survival model of endotoxin-induced acute lung injury,reduce lung impairs,and enhance the repair of VILI.However,whether MSC could attenuate PMN-predominant inflammatory in the VILI is still unknown.This study aimed to test whether MSC intervention could attenuate the PMN-predominate inflammatory in the mechanical VILI.Methods:Sprague-Dawley rats were ventilated for 2 hours with large tidal volume (20 mL/kg).MSCs were given before or after ventilation.The inflammatory chemokines and gas exchange were observed and compared dynamically until 4 hours after ventilation,and pulmonary pathological change and activation of PMN were observed and compared 4 hours after ventilation.Results:Mechanical ventilation (MV) caused significant lung injury reflected by increasing in PMN pulmonary sequestration,inflammatory chemokines (tumor necrosis factor-alpha,interleukin-6 and macrophage inflammatory protein 2) in the bronchoalveolar lavage fluid,and injury score of the lung tissue.These changes were accompanied with excessive PMN activation which reflected by increases in PMN elastase activity,production of radical oxygen series.MSC intervention especially pretreatment attenuated subsequent lung injury,systemic inflammation response and PMN pulmonary sequestration and excessive PMN activation initiated by injurious ventilation.Conclusions:MV causes profound lung injury and PMN-predominate inflammatory responses.The protection effect of MSC in the VILI rat model is related to the suppression of the PMN activation.

  8. A physically-modified saline suppresses neuronal apoptosis, attenuates tau phosphorylation and protects memory in an animal model of Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Khushbu K Modi

    Full Text Available Alzheimer's disease (AD, the leading cause of dementia in the aging population, is characterized by the presence of neuritic plaques, neurofibrillary tangles and extensive neuronal apoptosis. Neuritic plaques are mainly composed of aggregates of amyloid-β (Aβ protein while neurofibrillary tangles are composed of the hyperphosphorylated tau protein. Despite intense investigations, no effective therapy is currently available to halt the progression of this disease. Here, we have undertaken a novel approach to attenuate apoptosis and tau phosphorylation in cultured neuronal cells and in a transgenic animal model of AD. RNS60 is a 0.9% saline solution containing oxygenated nanobubbles that is generated by subjecting normal saline to Taylor-Couette-Poiseuille (TCP flow under elevated oxygen pressure. In our experiments, fibrillar Aβ1-42, but not the reverse peptide Aβ42-1, induced apoptosis and cell death in human SHSY5Y neuronal cells. RNS60, but not NS (normal saline, RNS10.3 (TCP-modified saline without excess oxygen or PNS60 (saline containing excess oxygen without TCP modification, attenuated Aβ(1-42-induced cell death. RNS60 inhibited neuronal cell death via activation of the type 1A phosphatidylinositol-3 (PI-3 kinase-Akt-BAD pathway. Furthermore, RNS60 also decreased Aβ(1-42-induced tau phosphorylation via (PI-3 kinase-Akt-mediated inhibition of GSK-3β. Similarly, RNS60 treatment suppressed neuronal apoptosis, attenuated Tau phosphorylation, inhibited glial activation, and reduced the burden of Aβ in the hippocampus and protected memory and learning in 5XFAD transgenic mouse model of AD. Therefore, RNS60 may be a promising pharmaceutical candidate in halting or delaying the progression of AD.

  9. Gamma-Glutamyl Cysteine Attenuates Tissue Damage and Enhances Tissue Regeneration in a rat Model of Lead-Induced Nephrotoxicity.

    Science.gov (United States)

    Salama, Samir A; Arab, Hany H; Maghrabi, Ibrahim A; Hassan, Memy H; AlSaeed, Mohammed S

    2016-09-01

    Lead is a biohazardous metal that is commonly involved in human illness including renal injury. Although it is a non-redox reactive metal, lead-induced renal injury is largely based on oxidative stress. The current work aimed at exploring the possible protective effect of γ-glutamyl cysteine (γGC) against lead-induced renal injury. Rats were allocated to normal and γGC control groups, lead-treated group, and lead and γGC-treated group. γGC alleviated lead-induced renal injury as evidenced by attenuation of histopathological aberration, amelioration of oxidative injury as demonstrated by significant reduction in lipid and protein oxidation, elevation of total antioxidant capacity, and glutathione level. The activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) was significantly elevated. γGC significantly decreased levels of the proinflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1β and the activity of the apoptotic marker caspase-3. In addition, γGC reduced kidney lead content, enhanced weight gain, and improved renal function as demonstrated by reduced serum levels of urea and creatinine. Importantly, γGC upregulated proliferating cell nuclear antigen (PCNA) expression, denoting enhanced renal regenerative capacity. Together, our findings highlight evidence for alleviating effects of γGC against lead-induced renal injury that is potentially mediated through diminution of oxidative tissue injury, reduction of inflammatory response, attenuation of apoptosis, and enhancement of renal regenerative capacity.

  10. Gamma-Glutamyl Cysteine Attenuates Tissue Damage and Enhances Tissue Regeneration in a rat Model of Lead-Induced Nephrotoxicity.

    Science.gov (United States)

    Salama, Samir A; Arab, Hany H; Maghrabi, Ibrahim A; Hassan, Memy H; AlSaeed, Mohammed S

    2016-09-01

    Lead is a biohazardous metal that is commonly involved in human illness including renal injury. Although it is a non-redox reactive metal, lead-induced renal injury is largely based on oxidative stress. The current work aimed at exploring the possible protective effect of γ-glutamyl cysteine (γGC) against lead-induced renal injury. Rats were allocated to normal and γGC control groups, lead-treated group, and lead and γGC-treated group. γGC alleviated lead-induced renal injury as evidenced by attenuation of histopathological aberration, amelioration of oxidative injury as demonstrated by significant reduction in lipid and protein oxidation, elevation of total antioxidant capacity, and glutathione level. The activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) was significantly elevated. γGC significantly decreased levels of the proinflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and IL-1β and the activity of the apoptotic marker caspase-3. In addition, γGC reduced kidney lead content, enhanced weight gain, and improved renal function as demonstrated by reduced serum levels of urea and creatinine. Importantly, γGC upregulated proliferating cell nuclear antigen (PCNA) expression, denoting enhanced renal regenerative capacity. Together, our findings highlight evidence for alleviating effects of γGC against lead-induced renal injury that is potentially mediated through diminution of oxidative tissue injury, reduction of inflammatory response, attenuation of apoptosis, and enhancement of renal regenerative capacity. PMID:26767370

  11. Photonic Crystal Fiber Attenuator

    Institute of Scientific and Technical Information of China (English)

    Joo Beom Eom; Hokyung Kim; Jinchae Kim; Un-Chul Paek; Byeong Ha Lee

    2003-01-01

    We propose a novel fiber attenuator based on photonic crystal fibers. The difference in the modal field diameters of a conventional single mode fiber and a photonic crystal fiber was used. A variable optical attenuator was also achieved by applying macro-bending on the PCF part of the proposed attenuator

  12. Sentence Recognition Prediction for Hearing-impaired Listeners in Stationary and Fluctuation Noise With FADE: Empowering the Attenuation and Distortion Concept by Plomp With a Quantitative Processing Model.

    Science.gov (United States)

    Kollmeier, Birger; Schädler, Marc René; Warzybok, Anna; Meyer, Bernd T; Brand, Thomas

    2016-01-01

    To characterize the individual patient's hearing impairment as obtained with the matrix sentence recognition test, a simulation Framework for Auditory Discrimination Experiments (FADE) is extended here using the Attenuation and Distortion (A+D) approach by Plomp as a blueprint for setting the individual processing parameters. FADE has been shown to predict the outcome of both speech recognition tests and psychoacoustic experiments based on simulations using an automatic speech recognition system requiring only few assumptions. It builds on the closed-set matrix sentence recognition test which is advantageous for testing individual speech recognition in a way comparable across languages. Individual predictions of speech recognition thresholds in stationary and in fluctuating noise were derived using the audiogram and an estimate of the internal level uncertainty for modeling the individual Plomp curves fitted to the data with the Attenuation (A-) and Distortion (D-) parameters of the Plomp approach. The "typical" audiogram shapes from Bisgaard et al with or without a "typical" level uncertainty and the individual data were used for individual predictions. As a result, the individualization of the level uncertainty was found to be more important than the exact shape of the individual audiogram to accurately model the outcome of the German Matrix test in stationary or fluctuating noise for listeners with hearing impairment. The prediction accuracy of the individualized approach also outperforms the (modified) Speech Intelligibility Index approach which is based on the individual threshold data only.

  13. Silymarin attenuated hepatic steatosis through regulation of lipid metabolism and oxidative stress in a mouse model of nonalcoholic fatty liver disease (NAFLD).

    Science.gov (United States)

    Ni, Xunjun; Wang, Haiyan

    2016-01-01

    Silymarin, which derived from the milk thistle plant (silybum marianum), has been used for centuries as a natural remedy for diseases of the liver and biliary tract. Considering the therapeutic potential to liver disease, we tested efficacy of silymarin on hepatic steatosis with a high fat diet (HFD)-induced mouse model of non-alcoholic fatty liver disease (NAFLD), and investigated possible effects on lipid metabolic pathways. In our study, silymarin could attenuate the hepatic steatosis, which was proved by both Oil Red O staining and hepatic triglyceride (TG) level determination. Furthermore, compared with INT-747, a potent and selective FXR agonist, silymarin could preserve plasmatic high-density lipoprotein cholesterol (HDL-C) to a higher level and low-density lipoprotein cholesterol (LDL-C) to a lower level, which benefited more to the circulation system. Through real-time PCR analysis, we clarified a vital protective role of silymarin in mRNA regulation of genes involved in lipid metabolism and oxidative stress. It was also shown that silymarin had no effects on body weight, food intake, and liver transaminase. Taken together, silymarin could attenuate hepatic steatosis in a mouse model of NAFLD through regulation of lipid metabolism and oxidative stress, and benefit to the circulation system. All these findings shed new light on NAFLD treatment. PMID:27158393

  14. Fresh frozen plasma resuscitation attenuates platelet dysfunction compared with normal saline in a large animal model of multisystem trauma

    DEFF Research Database (Denmark)

    Sillesen, Martin; Johansson, Pär I; Rasmussen, Lars S;

    2014-01-01

    BACKGROUND: Platelet dysfunction following trauma has been identified as an independent predictor of mortality. We hypothesized that fresh frozen plasma (FFP) resuscitation would attenuate platelet dysfunction compared with 0.9% normal saline (NS). METHODS: Twelve swine were subjected...... volume FFP (n = 6) and monitored for 6 hours. Platelet function was assessed by adenosine diphosphate (ADP)-induced platelet aggregation at baseline, after 2 hours of shock following resuscitation, and 6 hours after resuscitation. Fibrinogen levels and markers of platelet activation (transforming growth...... factor β [TGF-β], sP-Selectin, and CD40L) as well as endothelial injury (intercellular adhesion molecule 1 [ICAM-1], vascular cell adhesion molecule 1 [VCAM-1]) were also assayed. Thromboelastography was used to measure clotting activity. RESULTS: ADP-induced platelet aggregation was significantly higher...

  15. A biogeochemical transport model to simulate the attenuation of chlorinated hydrocarbon contaminant fluxes across the groundwater-surface water interface

    DEFF Research Database (Denmark)

    Malaguerra, Flavio; Binning, Philip John; Albrechtsen, Hans-Jørgen

    2009-01-01

    Chlorinated hydrocarbons originating from point sources are amongst the most prevalent contaminants of ground water and surface water resources. Riparian zones may play an important role in the attenuation of contaminant concentrations when contaminant plumes flow from groundwater to surface water...... because of the occurrence of redox gradients, strongly reductive conditions and high biological activity. In order to meet the expectations of the EU Water Framework Directive, an evaluation of the impact of such plumes on surface water is needed. The aim of this work is to develop a groundwater transport...... number of geochemical processes, allows the simulation of soil geochemical transformations when microbial by-products are released to surface water, and the consideration of non-linear feedbacks on bacterial growth and pollutant transformations. Sensitivity analysis is performed through Monte Carlo...

  16. A simple model of ultrasound propagation in a cavitating liquid. Part I: Theory, nonlinear attenuation and traveling wave generation

    CERN Document Server

    Louisnard, Olivier

    2013-01-01

    The bubbles involved in sonochemistry and other applications of cavitation oscillate inertially. A correct estimation of the wave attenuation in such bubbly media requires a realistic estimation of the power dissipated by the oscillation of each bubble, by thermal diffusion in the gas and viscous friction in the liquid. Both quantities and calculated numerically for a single inertial bubble driven at 20 kHz, and are found to be several orders of magnitude larger than the linear prediction. Viscous dissipation is found to be the predominant cause of energy loss for bubbles small enough. Then, the classical nonlinear Caflish equations describing the propagation of acoustic waves in a bubbly liquid are recast and simplified conveniently. The main harmonic part of the sound field is found to fulfill a nonlinear Helmholtz equation, where the imaginary part of the squared wave number is directly correlated with the energy lost by a single bubble. For low acoustic driving, linear theory is recovered, but for larger ...

  17. Oridonin Attenuates Synaptic Loss and Cognitive Deficits in an Aβ1-42-Induced Mouse Model of Alzheimer's Disease.

    Directory of Open Access Journals (Sweden)

    Sulei Wang

    Full Text Available Synaptic loss induced by beta-amyloid (Aβ plays a critical role in the pathophysiology of Alzheimer's disease (AD, but the mechanisms underlying this process remain unknown. In this study, we found that oridonin (Ori rescued synaptic loss induced by Aβ1-42 in vivo and in vitro and attenuated the alterations in dendritic structure and spine density observed in the hippocampus of AD mice. In addition, Ori increased the expression of PSD-95 and synaptophysin and promoted mitochondrial activity in the synaptosomes of AD mice. Ori also activated the BDNF/TrkB/CREB signaling pathway in the hippocampus of AD mice. Furthermore, in the Morris water maze test, Ori reduced latency and searching distance and increased the number of platform crosses in AD mice. These data suggest that Ori might prevent synaptic loss and improve behavioral symptoms in Aβ1-42-induced AD mice.

  18. Design of model-based disturbance attenuation for linear motor%直线电机的基于模型扰动抑制设计

    Institute of Scientific and Technical Information of China (English)

    张凤; 郭庆鼎; 勾丽丽; 王飞

    2001-01-01

    This paper adopts Model- Based Disturbance Attenuation (MBDA) method to attenuates external disturbances such as frictional forces, cutting forces, load variations for a permanent magnet linear AC synchronous motor (PMLSM) with high precision and micro -feed. The MBDA uses the nominal plant which is in parallel form with the plant and the output feedback. The error signal, which is the difference between the plant output and the nominal plant output, is fed back through a compensator. (IP) controller is designed in velocity loop so as to meet the requirement of fast tracking and resist disturbance greatly. Simulation results verify that this control method has fast response speed and strong disturbance attenuation, it also can effectively increase processing precision.%针对高精度、微进给永磁直线交流同步电机驱动系统,采用基于模型的扰动抑制方法,对诸如摩擦力、切削力、负载变动之类的扰动进行抑制.同时针对速度环设计了积分-比例(IP)控制器,以满足系统快速跟踪指令的要求,并具有较强的抗扰动能力.仿真结果表明,该控制方法响应速度快,抗干扰能力强,且能有效地提高加工精度.

  19. Resistant starch and exercise independently attenuate weight regain on a high fat diet in a rat model of obesity

    Directory of Open Access Journals (Sweden)

    Johnson Ginger C

    2011-07-01

    Full Text Available Abstract Background Long-term weight reduction remains elusive for many obese individuals. Resistant starch (RS and exercise may be useful for weight maintenance. The effects of RS, with or without exercise, on weight regain was examined during relapse to obesity on a high carbohydrate, high fat (HC/HF diet. Methods Obesity-prone rats were fed ad libitum for 16 weeks then weight reduced on a low fat diet to induce a 17% body weight loss (weight reduced rats. Weight reduced rats were maintained on an energy-restricted low fat diet for 18 weeks, with or without a daily bout of treadmill exercise. Rats were then allowed free access to HC/HF diet containing low (0.3% or high (5.9% levels of RS. Weight regain, energy balance, body composition, adipocyte cellularity, and fuel utilization were monitored as rats relapsed to obesity and surpassed their original, obese weight. Results Both RS and exercise independently attenuated weight regain by reducing the energy gap between the drive to eat and suppressed energy requirements. Exercise attenuated the deposition of lean mass during relapse, whereas its combination with RS sustained lean mass accrual as body weight returned. Early in relapse, RS lowered insulin levels and reduced the deposition of fat in subcutaneous adipose tissue. Exercise cessation at five weeks of relapse led to increased weight gain, body fat, subcutaneous adipocytes, and decreased lean mass; all detrimental consequences to overall metabolic health. Conclusions These data are the first to show the complimentary effects of dietary RS and regular exercise in countering the metabolic drive to regain weight following weight loss and suggest that exercise cessation, in the context of relapse on a HC/HF diet, may have dire metabolic consequences.

  20. Pharmacological preconditioning with erythropoietin attenuates the organ injury and dysfunction induced in a rat model of hemorrhagic shock

    Directory of Open Access Journals (Sweden)

    Kiran K. Nandra

    2013-05-01

    Pre-treatment with erythropoietin (EPO has been demonstrated to exert tissue-protective effects against ‘ischemia-reperfusion’-type injuries. This protection might be mediated by mobilization of bone marrow endothelial progenitor cells (EPCs, which are thought to secrete paracrine factors. These effects could be exploited to protect against tissue injury induced in cases where hemorrhage is foreseeable, for example, prior to major surgery. Here, we investigate the effects of EPO pre-treatment on the organ injury and dysfunction induced by hemorrhagic shock (HS. Recombinant human EPO (1000 IU/kg/day i.p. was administered to rats for 3 days. Rats were subjected to HS on day 4 (pre-treatment protocol. Mean arterial pressure was reduced to 35±5 mmHg for 90 minutes, followed by resuscitation with 20 ml/kg Ringer’s lactate for 10 minutes and 50% of the shed blood for 50 minutes. Rats were sacrificed 4 hours after the onset of resuscitation. EPC (CD34+/flk-1+ cell mobilization was measured following the 3-day pre-treatment with EPO and was significantly increased compared with rats pre-treated with phosphate-buffered saline. EPO pre-treatment significantly attenuated organ injury and dysfunction (renal, hepatic and neuromuscular caused by HS. In livers from rats subjected to HS, EPO enhanced the phosphorylation of Akt (activation, glycogen synthase kinase-3β (GSK-3β; inhibition and endothelial nitric oxide synthase (eNOS; activation. In the liver, HS also caused an increase in nuclear translocation of p65 (activation of NF-κB, which was attenuated by EPO. This data suggests that repetitive dosing with EPO prior to injury might protect against the organ injury and dysfunction induced by HS, by a mechanism that might involve mobilization of CD34+/flk-1+ cells, resulting in the activation of the Akt-eNOS survival pathway and inhibition of activation of GSK-3β and NF-κB.

  1. AT1R blocker losartan attenuates intestinal epithelial cell apoptosis in a mouse model of Crohn's disease.

    Science.gov (United States)

    Liu, Tian-Jing; Shi, Yong-Yan; Wang, En-Bo; Zhu, Tong; Zhao, Qun

    2016-02-01

    Angiotensin II, which is the main effector of the renin‑angiotensin system, has an important role in intestinal inflammation via the angiotensin II type 1 receptor (AT1R). The present study aimed to investigate the protective effects of the AT1R blocker losartan on 2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced colitis. Losartan was administered to male adult C57BL/6 J mice 2 weeks prior to the induction of colitis, and images of the whole colon were captured to record changes, scored according to a microscopic scoring system, and reverse transcription-quantitative polymerase chain reaction were performed in order to investigate colonic inflammation. In addition, intestinal epithelial barrier permeability was evaluated, and intestinal epithelial cell (IEC) apoptosis was measured using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and apoptosis-related protein expression levels were detected by western blotting. Losartan was able to attenuate TNBS-induced body weight loss and colonic damage. Furthermore, T helper 1-mediated proinflammatory cytokines were suppressed by losartan, and gut permeability was largely preserved. TUNEL staining revealed reduced IEC apoptosis in the losartan-treated mice. Losartan also increased the B-cell lymphoma 2 (Bcl2)/Bcl-2-associated X protein (Bax) ratio and suppressed caspase-3 induction. These results suggested that the AT1R blocker losartan may attenuate TNBS-induced colitis by inhibiting the apoptosis of IECs. The effects of losartan were partially mediated through increasing the Bcl-2/Bax ratio and subsequently suppressing the induction of the proapoptotic mediator caspase-3.

  2. AT1R blocker losartan attenuates intestinal epithelial cell apoptosis in a mouse model of Crohn's disease.

    Science.gov (United States)

    Liu, Tian-Jing; Shi, Yong-Yan; Wang, En-Bo; Zhu, Tong; Zhao, Qun

    2016-02-01

    Angiotensin II, which is the main effector of the renin‑angiotensin system, has an important role in intestinal inflammation via the angiotensin II type 1 receptor (AT1R). The present study aimed to investigate the protective effects of the AT1R blocker losartan on 2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced colitis. Losartan was administered to male adult C57BL/6 J mice 2 weeks prior to the induction of colitis, and images of the whole colon were captured to record changes, scored according to a microscopic scoring system, and reverse transcription-quantitative polymerase chain reaction were performed in order to investigate colonic inflammation. In addition, intestinal epithelial barrier permeability was evaluated, and intestinal epithelial cell (IEC) apoptosis was measured using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and apoptosis-related protein expression levels were detected by western blotting. Losartan was able to attenuate TNBS-induced body weight loss and colonic damage. Furthermore, T helper 1-mediated proinflammatory cytokines were suppressed by losartan, and gut permeability was largely preserved. TUNEL staining revealed reduced IEC apoptosis in the losartan-treated mice. Losartan also increased the B-cell lymphoma 2 (Bcl2)/Bcl-2-associated X protein (Bax) ratio and suppressed caspase-3 induction. These results suggested that the AT1R blocker losartan may attenuate TNBS-induced colitis by inhibiting the apoptosis of IECs. The effects of losartan were partially mediated through increasing the Bcl-2/Bax ratio and subsequently suppressing the induction of the proapoptotic mediator caspase-3. PMID:26676112

  3. LF-15 & T7, synthetic peptides derived from tumstatin, attenuate aspects of airway remodelling in a murine model of chronic OVA-induced allergic airway disease.

    Directory of Open Access Journals (Sweden)

    Karryn T Grafton

    Full Text Available BACKGROUND: Tumstatin is a segment of the collagen-IV protein that is markedly reduced in the airways of asthmatics. Tumstatin can play an important role in the development of airway remodelling associated with asthma due to its anti-angiogenic properties. This study assessed the anti-angiogenic properties of smaller peptides derived from tumstatin, which contain the interface tumstatin uses to interact with the αVβ3 integrin. METHODS: Primary human lung endothelial cells were exposed to the LF-15, T3 and T7 tumstatin-derived peptides and assessed for cell viability and tube formation in vitro. The impact of the anti-angiogenic properties on airways hyperresponsiveness (AHR was then examined using a murine model of chronic OVA-induced allergic airways disease. RESULTS: The LF-15 and T7 peptides significantly reduced endothelial cell viability and attenuated tube formation in vitro. Mice exposed to OVA+ LF-15 or OVA+T7 also had reduced total lung vascularity and AHR was attenuated compared to mice exposed to OVA alone. T3 peptides reduced cell viability but had no effect on any other parameters. CONCLUSION: The LF-15 and T7 peptides may be appropriate candidates for use as novel pharmacotherapies due to their small size and anti-angiogenic properties observed in vitro and in vivo.

  4. Ultrasound transmission attenuation tomography using energy-scaled amplitude ratios

    Science.gov (United States)

    Chen, Ting; Shin, Junseob; Huang, Lianjie

    2016-04-01

    Ultrasound attenuation of breast tumors is related to their types and pathological states, and can be used to detect and characterize breast cancer. Particularly, ultrasound scattering attenuation can infer the margin properties of breast tumors. Ultrasound attenuation tomography quantitatively reconstructs the attenuation properties of the breast. Our synthetic-aperture breast ultrasound tomography system with two parallel transducer arrays records both ultrasound reflection and transmission signals. We develop an ultrasound attenuation tomography method using ultrasound energy-scaled amplitude decays of ultrasound transmission signals and conduct ultrasound attenuation tomography using a known sound-speed model. We apply our ultrasound transmission attenuation tomography method to a breast phantom dataset, and compare the ultrasound attenuation tomography results with conventional beamforming ultrasound images obtained using reflection signals. We show that ultrasound transmission attenuation tomography complements beamforming images in identifying breast lesions.

  5. Attenuation by spinal cord stimulation of a nociceptive reflex generated by colorectal distention in a rat model.

    Science.gov (United States)

    Greenwood-Van Meerveld, Beverley; Johnson, Anthony C; Foreman, Robert D; Linderoth, Bengt

    2003-02-28

    The mechanisms underlying the cause and treatment of visceral pain of gastrointestinal origin are poorly understood. Previous clinical studies have shown that spinal cord stimulation (SCS) attenuates neuropathic and ischemic pain, and animal experiments have provided knowledge about probable physiological mechanisms. The goal of the present study was to investigate whether SCS influences colonic sensitivity in a conscious rat. A visceromotor behavioral response (VMR), induced by colorectal distention, was used to quantify the level of colonic sensitivity. Under anesthesia, an electrode (cathode) was placed on the dorsal surface of the spinal cord at L1. One week after implantation of the SCS electrode, the effects of stimulation delivered with different intensities (50 Hz, 0.2 ms for 30 min) on colonic sensitivity were determined. Nociceptive levels of colorectal distention (60 mm Hg for 10 min) induced an enhanced VMR quantified as an increased number of abdominal muscle contractions compared to controls in which the balloon catheter was inserted into the colorectal region but not distended. Colonic sensitization with acetic acid increased the VMR to innocuous levels of colorectal distention (30 mm Hg for 10 min). We found that SCS induced a significant depression of the VMR produced by colorectal distention in both normal rats and those with sensitized colons. The suppressive effect of SCS on colonic sensitivity suggests that SCS may have therapeutic potential for the treatment of visceral pain of gastrointestinal origin associated with abdominal cramping and painful abdominal spasms. PMID:12559199

  6. Repetitive Hyperbaric Oxygenation Attenuates Reactive Astrogliosis and Suppresses Expression of Inflammatory Mediators in the Rat Model of Brain Injury

    Directory of Open Access Journals (Sweden)

    Irena Lavrnja

    2015-01-01

    Full Text Available The exact mechanisms by which treatment with hyperbaric oxygen (HBOT exerts its beneficial effects on recovery after brain injury are still unrevealed. Therefore, in this study we investigated the influence of repetitive HBOT on the reactive astrogliosis and expression of mediators of inflammation after cortical stab injury (CSI. CSI was performed on male Wistar rats, divided into control, sham, and lesioned groups with appropriate HBO. The HBOT protocol was as follows: 10 minutes of slow compression, 2.5 atmospheres absolute (ATA for 60 minutes, and 10 minutes of slow decompression, once a day for 10 consecutive days. Data obtained using real-time polymerase chain reaction, Western blot, and immunohistochemical and immunofluorescence analyses revealed that repetitive HBOT applied after the CSI attenuates reactive astrogliosis and glial scarring, and reduces expression of GFAP (glial fibrillary acidic protein, vimentin, and ICAM-1 (intercellular adhesion molecule-1 both at gene and tissue levels. In addition, HBOT prevents expression of CD40 and its ligand CD40L on microglia, neutrophils, cortical neurons, and reactive astrocytes. Accordingly, repetitive HBOT, by prevention of glial scarring and limiting of expression of inflammatory mediators, supports formation of more permissive environment for repair and regeneration.

  7. Repetitive Hyperbaric Oxygenation Attenuates Reactive Astrogliosis and Suppresses Expression of Inflammatory Mediators in the Rat Model of Brain Injury

    Science.gov (United States)

    Lavrnja, Irena; Parabucki, Ana; Dacic, Sanja; Savic, Danijela; Pantic, Igor; Stojiljkovic, Mirjana; Pekovic, Sanja

    2015-01-01

    The exact mechanisms by which treatment with hyperbaric oxygen (HBOT) exerts its beneficial effects on recovery after brain injury are still unrevealed. Therefore, in this study we investigated the influence of repetitive HBOT on the reactive astrogliosis and expression of mediators of inflammation after cortical stab injury (CSI). CSI was performed on male Wistar rats, divided into control, sham, and lesioned groups with appropriate HBO. The HBOT protocol was as follows: 10 minutes of slow compression, 2.5 atmospheres absolute (ATA) for 60 minutes, and 10 minutes of slow decompression, once a day for 10 consecutive days. Data obtained using real-time polymerase chain reaction, Western blot, and immunohistochemical and immunofluorescence analyses revealed that repetitive HBOT applied after the CSI attenuates reactive astrogliosis and glial scarring, and reduces expression of GFAP (glial fibrillary acidic protein), vimentin, and ICAM-1 (intercellular adhesion molecule-1) both at gene and tissue levels. In addition, HBOT prevents expression of CD40 and its ligand CD40L on microglia, neutrophils, cortical neurons, and reactive astrocytes. Accordingly, repetitive HBOT, by prevention of glial scarring and limiting of expression of inflammatory mediators, supports formation of more permissive environment for repair and regeneration. PMID:25972624

  8. Modeling and Forecasting of Depletion of Additives in Car Engine Oils Using Attenuated Total Reflectance Fast Transform Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Ronald Nguele

    2014-11-01

    Full Text Available On average, additives make up to 7% of a typical lubricant base. Commonly, they are blended with lube oils to enhance specific features thereby improving their qualities. Ultimately, additives participate in the performance of car engine oils. Using an analytical tool, attenuated total reflectance fast transform infrared spectroscopy, various grades of car engine oils, at different mileages, were analyzed. Sulfate oxidation and wear were found to trigger chemical processes which, in the long run, cause lubricant degradation while carbonyl oxidation was observed to occur only at a slow rate. Based upon data obtained from infrared spectra and using a curve fitting technique, mathematical equations predicting the theoretical rates of chemical change due to the aforementioned processes were examined. Additive depletions were found to obey exponential regression rather than polynomial. Moreover, breakpoint (breakpoint is used here to denote the initiation of deterioration of additives and critical mileage (critical mileage defines the distance at which the lubricant is chemically unusable of both samples were determined.

  9. Curcumin attenuates the middle cerebral artery occlusion-induced reduction in γ-enolase expression in an animal model.

    Science.gov (United States)

    Gim, Sang-Ah; Lee, So-Ra; Shah, Fawad-Ali; Koh, Phil-Ok

    2015-12-01

    Curcumin exerts a protective effect in cerebral ischemia through its anti-oxidant and anti-inflammatory activities. γ-enolase is a glycolytic enzyme expressed in neurons that is known to exerts a neuroprotective effect. We investigated whether curcumin regulates γ-enolase expression in focal cerebral ischemic injury in rats. Middle cerebral artery occlusion (MCAO) was performed to induce focal cerebral ischemia. Adult male rats were injected intraperitoneally with either vehicle or curcumin (50 mg/kg) 1 h after MCAO and cerebral cortex tissues were isolated 24 h after MCAO. We found that MCAO-induced injury resulted in a reduction in γ-enolase expression in vehicle-treated animals using a proteomics approach. However, this reduction was attenuated in animals with MCAO treated with curcumin. Reverse-transcription PCR and Western blot analyses also showed that curcumin treatment prevented the MCAO injury-induced reduction in γ-enolase expression. The results of this study suggest that curcumin exerts its neuroprotective function in focal cerebral ischemia by regulating the expression of γ-enolase. PMID:26755923

  10. Variable laser attenuator

    Science.gov (United States)

    Foltyn, Stephen R.

    1988-01-01

    The disclosure relates to low loss, high power variable attenuators comprng one or more transmissive and/or reflective multilayer dielectric filters. The attenuator is particularly suitable to use with unpolarized lasers such as excimer lasers. Beam attenuation is a function of beam polarization and the angle of incidence between the beam and the filter and is controlled by adjusting the angle of incidence the beam makes to the filter or filters. Filters are selected in accordance with beam wavelength.

  11. Simulation of Cloud-aerosol Lidar with Orthogonal Polarization (CALIOP Attenuated Backscatter Profiles Using the Global Model of Aerosol Processes (GLOMAP

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    Young Stuart

    2016-01-01

    Full Text Available To permit the calculation of the radiative effects of atmospheric aerosols, we have linked our aerosol-chemical transport model (CTMGLOMAP to a new radiation module (UKCARADAER. In order to help assess and improve the accuracy of the radiation code, in particular the height dependence of the predicted scattering, we have developed a module that simulates attenuated backscatter (ABS profiles that would be measured by the satellite-borne Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP if it were to sample an atmosphere with the same aerosol loading as predicted by the CTM. Initial results of our comparisons of the predicted ABS profiles with actual CALIOP data are encouraging but some differences are noted, particularly in marine boundary layers where the scattering is currently under-predicted and in dust layers where it is often over-predicted. The sources of these differences are being investigated.

  12. The set valued unified model of dispersion and attenuation for wave propagation in dielectric (and anelastic media

    Directory of Open Access Journals (Sweden)

    M. Caputo

    1998-06-01

    Full Text Available Since the dispersion and attenuation properties of dielectric and anelastic media, in the frequency domain, are expressed by similar formulae, as shown experimentally by Cole and Cole (1941 and Bagley and Torvik (1983, 1986 respectively, we note that the same properties may be represented in the time domain by means of an equation of the same form; this is obtained by introducing derivatives of fractional order into the system functions of the media. The Laplace Transforms (LT of such system functions contain fractional powers of the imaginary frequency and are, therefore, multivalued functions defined in the Riemann Sheets (RS of the function. We determine the response of the medium (dielectric o anelastic to a generic signal summing the time domain representation due to the branches of the solutions in the RSs of the LT. It is found that, if the initial conditions are equal in all the RSs, the solution is a sum of two exponentials with complex exponents, if the initial conditions are different in some of the RSs, then a transient for each of those RSs is added to the exponentials. In all cases a monochromatic wave is split into a set of waves with the same frequency and slightly different wavelengths which interfere and disperse. As a consequence a monochromatic electromagnetic wave with frequency around 1 MHz in water has a relevant dispersion and beats generating a tunnel effect. In the atmosphere of the Earth the dispersion of a monochromatic wave with frequency around 1 GHz, like those used in tracking artificial satellites, has a negligible effect on the accuracy of the determination of the position of the satellites and the positioning of the bench marks on the Earth. We also find the split eigenfunctions of the free modes of infinite plates and shells made of dielectric and anelastic media.

  13. Regulation of Th17/Treg function contributes to the attenuation of chronic airway inflammation by icariin in ovalbumin-induced murine asthma model.

    Science.gov (United States)

    Wei, Ying; Liu, Baojun; Sun, Jing; Lv, Yubao; Luo, Qingli; Liu, Feng; Dong, Jingcheng

    2015-06-01

    Icariin which is a flavonoid glucoside isolated from Epimedium brevicornu Maxim, has been reported to have anti-osteoporotic, anti-inflammatory and anti-depressant-like activities. In this study, we observed the effect of icariin on airway inflammation of ovalbumin (OVA)-induced murine asthma model and the associated regulatory mode on T-helper (Th)17 and regulatory T (Treg) cell function. Our data revealed that chronic OVA inhalation induced a dramatic increase in airway resistance (RL) and decrease in the lung dynamic compliance (Cdyn), and icariin and DEX treatment caused significant attenuation of such airway hyperresponsiveness (AHR). BALF cell counts demonstrated that icariin and DEX led to a prominent reduction in total leukocyte as well as lymphocyte, eosinophil, neutrophil, basophil and monocyte counts. Histological analysis results indicated that icariin and DEX alleviated the inflammatory cells infiltrating into the peribronchial tissues and goblet cells hyperplasia and mucus hyper-production. Flow cytometry test demonstrated that icariin or DEX administration resulted in a significant percentage reduction in CD4+RORγt+ T cells and elevation of CD4+Foxp3+ T cells in BALF. Furthermore, icariin or DEX caused a significant reduction in IL-6, IL-17 and TGF-β level in BALF. Unfortunately, icariin had no effect on IL-10 level in BALF. Western blot assay found that icariin or DEX suppressed RORγt and promoted Foxp3 expression in the lung tissue. qPCR analysis revealed that icariin and DEX resulted in a notable decrease in RORγt and increase in Foxp3 mRNA expression in isolated spleen CD4+ T cell. In conclusion, our results suggested that icariin was effective in the attenuation of AHR and chronic airway inflammatory changes in OVA-induced murine asthma model, and this effect was associated with regulation of Th17/Treg responses, which indicated that icariin may be used as a potential therapeutic method to treat asthma with Th17/Treg imbalance phenotype

  14. Rapamycin improves motor function, reduces 4-hydroxynonenal adducted protein in brain, and attenuates synaptic injury in a mouse model of synucleinopathy

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    Xiang Bai

    2015-08-01

    Full Text Available Background: Synucleinopathy is any of a group of age-related neurodegenerative disorders including Parkinson's disease, multiple system atrophy, and dementia with Lewy Bodies, which is characterized by α-synuclein inclusions and parkinsonian motor deficits affecting millions of patients worldwide. But there is no cure at present for synucleinopathy. Rapamycin has been shown to be neuroprotective in several in vitro and in vivo synucleinopathy models. However, there are no reports on the long-term effects of RAPA on motor function or measures of neurodegeneration in models of synucleinopathy. Methods: We determined whether long-term feeding a rapamycin diet (14 ppm in diet; 2.25 mg/kg body weight/day improves motor function in neuronal A53T α-synuclein transgenic mice (TG and explored underlying mechanisms using a variety of behavioral and biochemical approaches. Results: After 24 weeks of treatment, rapamycin improved performance on the forepaw stepping adjustment test, accelerating rotarod and pole test. Rapamycin did not alter A53T α-synuclein content. There was no effect of rapamycin treatment on midbrain or striatal monoamines or their metabolites. Proteins adducted to the lipid peroxidation product 4-hydroxynonenal were decreased in brain regions of both wild-type and TG mice treated with rapamycin. Reduced levels of the presynaptic marker synaptophysin were found in several brain regions of TG mice. Rapamycin attenuated the loss of synaptophysin protein in the affected brain regions. Rapamycin also attenuated the loss of synaptophysin protein and prevented the decrease of neurite length in SH-SY5Y cells treated with 4-hydroxynonenal. Conclusion: Taken together, these data suggest that rapamycin, an FDA approved drug, may prove useful in the treatment of synucleinopathy.

  15. Selective Cathepsin S Inhibition with MIV-247 Attenuates Mechanical Allodynia and Enhances the Antiallodynic Effects of Gabapentin and Pregabalin in a Mouse Model of Neuropathic Pain.

    Science.gov (United States)

    Hewitt, Ellen; Pitcher, Thomas; Rizoska, Biljana; Tunblad, Karin; Henderson, Ian; Sahlberg, Britt-Louise; Grabowska, Urszula; Classon, Björn; Edenius, Charlotte; Malcangio, Marzia; Lindström, Erik

    2016-09-01

    Cathepsin S inhibitors attenuate mechanical allodynia in preclinical neuropathic pain models. The current study evaluated the effects when combining the selective cathepsin S inhibitor MIV-247 with gabapentin or pregabalin in a mouse model of neuropathic pain. Mice were rendered neuropathic by partial sciatic nerve ligation. MIV-247, gabapentin, or pregabalin were administered alone or in combination via oral gavage. Mechanical allodynia was assessed using von Frey hairs. Neurobehavioral side effects were evaluated by assessing beam walking. MIV-247, gabapentin, and pregabalin concentrations in various tissues were measured. Oral administration of MIV-247 (100-200 µmol/kg) dose-dependently attenuated mechanical allodynia by up to approximately 50% reversal when given as a single dose or when given twice daily for 5 days. No behavioral deficits were observed at any dose of MIV-247 tested. Gabapentin (58-350 µmol/kg) and pregabalin (63-377 µmol/kg) also inhibited mechanical allodynia with virtually complete reversal at the highest doses tested. The minimum effective dose of MIV-247 (100 µmol/kg) in combination with the minimum effective dose of pregabalin (75 µmol/kg) or gabapentin (146 µmol/kg) resulted in enhanced antiallodynic efficacy without augmenting side effects. A subeffective dose of MIV-247 (50 µmol/kg) in combination with a subeffective dose of pregabalin (38 µmol/kg) or gabapentin (73 µmol/kg) also resulted in substantial efficacy. Plasma levels of MIV-247, gabapentin, and pregabalin were similar when given in combination as to when given alone. Cathepsin S inhibition with MIV-247 exerts significant antiallodynic efficacy alone, and also enhances the effect of gabapentin and pregabalin without increasing side effects or inducing pharmacokinetic interactions.

  16. Cinnamon and Its Metabolite Sodium Benzoate Attenuate the Activation of p21rac and Protect Memory and Learning in an Animal Model of Alzheimer's Disease.

    Directory of Open Access Journals (Sweden)

    Khushbu K Modi

    Full Text Available This study underlines the importance of cinnamon, a commonly used natural spice and flavoring material, and its metabolite sodium benzoate (NaB in attenuating oxidative stress and protecting memory and learning in an animal model of Alzheimer's disease (AD. NaB, but not sodium formate, was found to inhibit LPS-induced production of reactive oxygen species (ROS in mouse microglial cells. Similarly, NaB also inhibited fibrillar amyloid beta (Aβ- and 1-methyl-4-phenylpyridinium(+-induced microglial production of ROS. Although NaB reduced the level of cholesterol in vivo in mice, reversal of the inhibitory effect of NaB on ROS production by mevalonate, and geranylgeranyl pyrophosphate, but not cholesterol, suggests that depletion of intermediates, but not end products, of the mevalonate pathway is involved in the antioxidant effect of NaB. Furthermore, we demonstrate that an inhibitor of p21rac geranylgeranyl protein transferase suppressed the production of ROS and that NaB suppressed the activation of p21rac in microglia. As expected, marked activation of p21rac was observed in the hippocampus of subjects with AD and 5XFAD transgenic (Tg mouse model of AD. However, oral feeding of cinnamon (Cinnamonum verum powder and NaB suppressed the activation of p21rac and attenuated oxidative stress in the hippocampus of Tg mice as evident by decreased dihydroethidium (DHE and nitrotyrosine staining, reduced homocysteine level and increased level of reduced glutathione. This was accompanied by suppression of neuronal apoptosis, inhibition of glial activation, and reduction of Aβ burden in the hippocampus and protection of memory and learning in transgenic mice. Therefore, cinnamon powder may be a promising natural supplement in halting or delaying the progression of AD.

  17. Stormwater Attenuation by Green Roofs

    Science.gov (United States)

    Sims, A.; O'Carroll, D. M.; Robinson, C. E.; Smart, C. C.

    2014-12-01

    Innovative municipal stormwater management technologies are urgently required in urban centers. Inadequate stormwater management can lead to excessive flooding, channel erosion, decreased stream baseflows, and degraded water quality. A major source of urban stormwater is unused roof space. Green roofs can be used as a stormwater management tool to reduce roof generated stormwater and generally improve the quality of runoff. With recent legislation in some North American cities, including Toronto, requiring the installation of green roofs on large buildings, research on the effectiveness of green roofs for stormwater management is important. This study aims to assess the hydrologic response of an extensive sedum green roof in London, Ontario, with emphasis on the response to large precipitation events that stress municipal stormwater infrastructure. A green roof rapidly reaches field capacity during large storm events and can show significantly different behavior before and after field capacity. At field capacity a green roof has no capillary storage left for retention of stormwater, but may still be an effective tool to attenuate peak runoff rates by transport through the green roof substrate. The attenuation of green roofs after field capacity is linked to gravity storage, where gravity storage is the water that is temporarily stored and can drain freely over time after field capacity has been established. Stormwater attenuation of a modular experimental green roof is determined from water balance calculations at 1-minute intervals. Data is used to evaluate green roof attenuation and the impact of field capacity on peak flow rates and gravity storage. In addition, a numerical model is used to simulate event based stormwater attenuation. This model is based off of the Richards equation and supporting theory of multiphase flow through porous media.

  18. ATTENUATION AND FLANKING TRANSMISSION IN LIGHTWEIGHT STRUCTURES

    DEFF Research Database (Denmark)

    Brunskog, Jonas; Lhomond, Alice; Ohlrich, Mogens

    2007-01-01

    In this paper the attenuation and flanking transmissions of impact noise in lightweight building structures is studied using a modal approach. The structural field is mainly analysed, putting the main attention to the parts being important in the modelling. The amount of attenuation produced by the...... periodically reinforcing beams used in lightweight building structures is analysed. The consequence of these factors in modelling flanking transmission is also discussed....

  19. Dose attenuation by a carbon fiber linac couch and modeling with a treatment planning system; Medida de la atenuacion producida por la mesa de tratamiento de un acelerador lineal y su modelado en un sistema de planificacion

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Galiano, P.; Garcia Sancho, J.M.; Crelgo, D.; Pamos, M.; Fernandez, J.; Vivanco, J.

    2010-07-01

    The purpose of this work is to investigate the attenuation caused by a carbon fiber linac treatment couch and the ability of a commercial radiotherapy treatment planning system to simulate it. The attenuation caused by an Exact{copyright} treatment couch in a Varian{copyright} Clinac{copyright} 2100 C/D was characterized in detail. Both 6 MV and 18 MV photon beams were studied. The treatment couch was modeled and incorporated to Elekta{copyright} XiO{copyright} treatment planning system. Measured and computed attenuation values were compared. As a result we found that the attenuation caused by this complex treatment couch is strongly dependent on the incidence angle of the beam. The measured attenuation values reach 16% for 6 MV and 10% for 18 MV. The model incorporated to the treatment planning software allows reducing the differences between measured and calculated data below 2.5% and 2.0% for 6 MV and 18 MV respectively. In conclusion, it is strongly recommended accounting for the perturbation caused by this carbon fiber treatment couch when the beam intersects it. The treatment planning system studied can simulate this treatment couch accurately. Clinical implementation of the described method requires a reliable procedure to reproduce the same patient geometry in the treatment delivery and planning. (Author).

  20. Coupling of Realistic Rate Estimates with Genomics for Assessing Contaminant Attenuation and Long-Term Plume Containment - Task 4: Modeling - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Robert C. Starr

    2005-10-31

    seven plumes at 24 DOE facilities were screened, and 14 plumes were selected for detailed examination. In the plumes selected for further study, spatial changes in the concentration of a conservative co-contaminant were used to compensate for the effects of mixing and temporal changes in TCE release from the contaminant source. Decline in TCE concentration along a flow path in excess of the co contaminant concentration decline was attributed to cometabolic degradation. This study indicated that TCE was degraded in 9 of the 14 plumes examined, with first order degradation half-lives ranging from about 1 to 12 years. TCE degradation in about two-thirds of the plumes examined suggests that cometabolism of TCE in aerobic groundwater is a common occurrence, in contrast to the conventional wisdom that TCE is recalcitrant in aerobic groundwater. The degradation half-life values calculated in this study are short enough that natural attenuation may be a viable remedy in many aerobic plumes. Computer modeling of groundwater flow and contaminant transport and degradation is frequently used to predict the evolution of groundwater plumes, and for evaluating natural attenuation and other remedial alternatives. An important aspect of a computer model is the mathematical approach for describing degradation kinetics. A common approach is to assume that degradation occurs as a first-order process. First order kinetics are easily incorporated into transport models and require only a single value (a degradation half-life) to describe reaction kinetics. The use of first order kinetics is justified in many cases because more elaborate kinetic equations often closely approximate first order kinetics under typical field conditions. A previous modeling study successfully simulated the INL TCE plume using first order degradation kinetics. TCE cometabolism is the result of TCE reacting with microbial enzymes that were produced for other purposes, such as oxidizing a growth substrate to obtain

  1. Mucosal Immunization with Live Attenuated Francisella novicida U112ΔiglB Protects against Pulmonary F. tularensis SCHU S4 in the Fischer 344 Rat Model

    Science.gov (United States)

    Signarovitz, Aimee L.; Ray, Heather J.; Yu, Jieh-Juen; Guentzel, M. N.; Chambers, James P.; Klose, Karl E.; Arulanandam, Bernard P.

    2012-01-01

    The need for an efficacious vaccine against Francisella tularensis is a consequence of its low infectious dose and high mortality rate if left untreated. This study sought to characterize a live attenuated subspecies novicida-based vaccine strain (U112ΔiglB) in an established second rodent model of pulmonary tularemia, namely the Fischer 344 rat using two distinct routes of vaccination (intratracheal [i.t.] and oral). Attenuation was verified by comparing replication of U112ΔiglB with wild type parental strain U112 in F344 primary alveolar macrophages. U112ΔiglB exhibited an LD50>107 CFU compared to the wild type (LD50 = 5×106 CFU i.t.). Immunization with 107 CFU U112ΔiglB by i.t. and oral routes induced antigen-specific IFN-γ and potent humoral responses both systemically (IgG2a>IgG1 in serum) and at the site of mucosal vaccination (respiratory/intestinal compartment). Importantly, vaccination with U112ΔiglB by either i.t. or oral routes provided equivalent levels of protection (50% survival) in F344 rats against a subsequent pulmonary challenge with ∼25 LD50 (1.25×104 CFU) of the highly human virulent strain SCHU S4. Collectively, these results provide further evidence on the utility of a mucosal vaccination platform with a defined subsp. novicida U112ΔiglB vaccine strain in conferring protective immunity against pulmonary tularemia. PMID:23118885

  2. Mucosal immunization with live attenuated Francisella novicida U112ΔiglB protects against pulmonary F. tularensis SCHU S4 in the Fischer 344 rat model.

    Directory of Open Access Journals (Sweden)

    Aimee L Signarovitz

    Full Text Available The need for an efficacious vaccine against Francisella tularensis is a consequence of its low infectious dose and high mortality rate if left untreated. This study sought to characterize a live attenuated subspecies novicida-based vaccine strain (U112ΔiglB in an established second rodent model of pulmonary tularemia, namely the Fischer 344 rat using two distinct routes of vaccination (intratracheal [i.t.] and oral. Attenuation was verified by comparing replication of U112ΔiglB with wild type parental strain U112 in F344 primary alveolar macrophages. U112ΔiglB exhibited an LD(50>10(7 CFU compared to the wild type (LD(50 = 5 × 10(6 CFU i.t.. Immunization with 10(7 CFU U112ΔiglB by i.t. and oral routes induced antigen-specific IFN-γ and potent humoral responses both systemically (IgG2a>IgG1 in serum and at the site of mucosal vaccination (respiratory/intestinal compartment. Importantly, vaccination with U112ΔiglB by either i.t. or oral routes provided equivalent levels of protection (50% survival in F344 rats against a subsequent pulmonary challenge with ~25 LD(50 (1.25 × 10(4 CFU of the highly human virulent strain SCHU S4. Collectively, these results provide further evidence on the utility of a mucosal vaccination platform with a defined subsp. novicida U112ΔiglB vaccine strain in conferring protective immunity against pulmonary tularemia.

  3. GlyT-1 Inhibition Attenuates Attentional But Not Learning or Motivational Deficits of the Sp4 Hypomorphic Mouse Model Relevant to Psychiatric Disorders.

    Science.gov (United States)

    Young, Jared W; Kamenski, Mary E; Higa, Kerin K; Light, Gregory A; Geyer, Mark A; Zhou, Xianjin

    2015-11-01

    Serious mental illness occurs in 25% of the general population, with many disorders being neurodevelopmental, lifelong, and debilitating. The wide variation and overlap in symptoms across disorders increases the difficulty of research and treatment development. The NIMH Research Domain of Criteria initiative aims to improve our understanding of the molecular and behavioral consequences of specific neurodevelopmental mechanisms across disorders, enabling targeted treatment development. The transcription factor Specificity Protein 4 (SP4) is important for neurodevelopment and is genetically associated with both schizophrenia and bipolar disorder. Reduced Sp4 expression in mice (hypomorphic) reproduces several characteristics of psychiatric disorders. We further tested the utility of Sp4 hypomorphic mice as a model organism relevant to psychiatric disorders by assessing cognitive control plus effort and decision-making aspects of approach motivation using cross-species-relevant tests. Sp4 hypomorphic mice exhibited impaired attention as measured by the 5-Choice Continuous Performance Test, an effect that was attenuated by glycine type-1 transporter (GlyT-1) inhibition. Hypomorphic mice also exhibited reduced motivation to work for a reward and impaired probabilistic learning. These deficits may stem from affected anticipatory reward, analogous to anhedonia in patients with schizophrenia and other psychiatric disorders. Neither positive valence deficit was attenuated by GlyT-1 treatment, suggesting that these and the attentional deficits stem from different underlying mechanisms. Given the association of SP4 gene with schizophrenia and bipolar disorder, the present studies provide support that personalized GlyT-1 inhibition may treat attentional deficits in neuropsychiatric patients with low SP4 levels. PMID:25907107

  4. Neurotrophic effects of a cyanine dye via the PI3K-Akt pathway: attenuation of motor discoordination and neurodegeneration in an ataxic animal model.

    Directory of Open Access Journals (Sweden)

    Hitomi Ohta

    Full Text Available BACKGROUND: Neurotrophic factors may be future therapeutic agents for neurodegenerative disease. In the screening of biologically active molecules for neurotrophic potency, we found that a photosensitizing cyanine dye, NK-4, had remarkable neurotrophic activities and was a potent radical scavenger. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we evaluated the effect of NK-4 on the protection of neurons against oxidative damage and investigated the associated intracellular signaling pathways. Subsequently, we evaluated the effect of NK-4 in an animal model of neurodegeneration. In vitro, NK-4 showed dose-dependent protection of PC12 cells from toxicity induced by oxidative stress caused by hydrogen peroxide (H(2O(2 or 6-hydroxydopamine (6-OHDA. Comparison of extracellular signal-regulated kinase signaling pathways between treatment with NK-4 and nerve growth factor (NGF using K252a, an inhibitor of the NGF receptor TrkA, revealed that NK-4 activity occurs independently of NGF receptors. LY294002, a phosphatidylinositol 3-kinase (PI3K inhibitor, blocked the protective effect of NK-4, and NK-4 caused activation of Akt/protein kinase B, a downstream effector of PI3K. These results suggest that the neuroprotective effects of NK-4 are mediated by the PI3K-Akt signaling pathway. NK-4 treatment also attenuated stress-induced activation of SAPK/JNK, which suggests that NK-4 activates a survival signaling pathway and inhibits stress-activated apoptotic pathways independently of the TrkA receptor in neuronal cells. In vivo, administration of NK-4 improved motor coordination in genetic ataxic hamsters, as assessed by rota-rod testing. Histological analysis showed that cerebellar atrophy was significantly attenuated by NK-4 treatment. Notably, the Purkinje cell count in the treated group was threefold higher than that in the vehicle group. CONCLUSIONS/SIGNIFICANCE: These results suggest that NK-4 is a potential agent for therapy for neurodegenerative

  5. Residual hepatocellular carcinoma after oxaliplatin treatment has increased metastatic potential in a nude mouse model and is attenuated by Songyou Yin

    International Nuclear Information System (INIS)

    The opposite effects of chemotherapy, which enhance the malignancy of treated cancers such as hepatocellular carcinoma (HCC), are not well understood. We investigated this phenomenon and corresponding mechanisms to develop a novel approach for improving chemotherapy efficacy in HCC. Human hepatocellular carcinoma cell lines HepG2 (with low metastatic potential) and MHCC97L (with moderate metastatic potential) were used for the in vitro study. An orthotopic nude mouse model of human HCC was developed using MHCC97L cells. We then assessed the metastatic potential of surviving tumor cells after in vitro and in vivo oxaliplatin treatment. The molecular changes in surviving tumor cells were evaluated by western blot, immunofluorescence, and immunohistochemistry. The Chinese herbal extract Songyou Yin (composed of five herbs) was investigated in vivo to explore its effect on the metastatic potential of oxaliplatin-treated cancer cells. MHCC97L and HepG2 cells surviving oxaliplatin treatment showed enhanced migration and invasion in vitro. Residual HCC after in vivo oxaliplatin treatment demonstrated significantly increased metastasis to the lung (10/12 vs. 3/12) when re-inoculated into the livers of new recipient nude mice. Molecular changes consistent with epithelial-mesenchymal transition (EMT) were observed in oxaliplatin-treated tumor tissues and verified by in vitro experiments. The Chinese herbal extract Songyou Yin (4.2 and 8.4 g/kg) attenuated EMT and inhibited the enhanced metastatic potential of residual HCC in nude mice (6/15 vs. 13/15 and 3/15 vs. 13/15, respectively). The surviving HCC after oxaliplatin treatment underwent EMT and demonstrated increased metastatic potential. Attenuation of EMT by Songyou Yin may improve the efficacy of chemotherapy in HCC

  6. Clonorchis sinensis-derived total protein attenuates airway inflammation in murine asthma model by inducing regulatory T cells and modulating dendritic cell functions

    International Nuclear Information System (INIS)

    Highlights: → Treatment with Clonorchis sinensis-derived total protein attenuates OVA-induced airway inflammation and AHR to methacholine. → Induction of CD4+CD25+Foxp3+ T cells and IL-10 along with suppression of splenocyte proliferation by C. sinensis-derived total protein. → C. sinensis-derived total protein interferes with the expression of co-stimulatory molecules in DCs. -- Abstract: Asthma is characterized by Th2-mediated inflammation, resulting in airway hyperresponsiveness (AHR) through airway remodeling. Recent epidemiological and experimental reports have suggested an inverse relationship between the development of allergy and helminth infections. Infection by Clonorchis sinensis, a liver fluke that resides in the bile duct of humans, is endemic predominantly in Asia including Korea and China. Using a murine model for asthma, we investigated the effects of C. sinensis-derived total protein (Cs-TP) on allergen-induced airway inflammation and the mechanism underlying the protective effects of Cs-TP administration on asthma. Treatment with Cs-TP attenuated OVA-induced airway inflammation and methacholine-induced AHR, as well as eosinophilia development, lymphocyte infiltration into the lung, and goblet cell metaplasia. This protective effect of Cs-TP is associated with markedly reduced OVA-specific IgE and Th1/Th2 cytokine production. Moreover, Cs-TP increased the number of CD4+CD25+Foxp3+ regulatory T (Treg) cells as well as their suppressive activity. In fact, proliferation of OVA-restimulated splenocytes was suppressed significantly. Cs-TP also inhibited the expression of such co-stimulatory molecules as CD80, CD86, and CD40 in LPS- or OVA-stimulated dendritic cells (DCs), suggesting that Cs-TP could interfere with the capacity of airway DCs to prime naive T cells. These data demonstrate the capacity of C. sinensis to ameliorate allergic asthma and broaden our understanding of the paradoxical relationship between the allergic immune response and

  7. Mechanical ventilation with high tidal volumes attenuates myocardial dysfunction by decreasing cardiac edema in a rat model of LPS-induced peritonitis

    Directory of Open Access Journals (Sweden)

    Smeding Lonneke

    2012-03-01

    Full Text Available Abstract Background Injurious mechanical ventilation (MV may augment organ injury remote from the lungs. During sepsis, myocardial dysfunction is common and increased endothelial activation and permeability can cause myocardial edema, which may, among other factors, hamper myocardial function. We investigated the effects of MV with injuriously high tidal volumes on the myocardium in an animal model of sepsis. Methods Normal rats and intraperitoneal (i.p. lipopolysaccharide (LPS-treated rats were ventilated with low (6 ml/kg and high (19 ml/kg tidal volumes (Vt under general anesthesia. Non-ventilated animals served as controls. Mean arterial pressure (MAP, central venous pressure (CVP, cardiac output (CO and pulmonary plateau pressure (Pplat were measured. Ex vivo myocardial function was measured in isolated Langendorff-perfused hearts. Cardiac expression of endothelial vascular cell adhesion molecule (VCAM-1 and edema were measured to evaluate endothelial inflammation and leakage. Results MAP decreased after LPS-treatment and Vt-dependently, both independent of each other and with interaction. MV Vt-dependently increased CVP and Pplat and decreased CO. LPS-induced peritonitis decreased myocardial function ex vivo but MV attenuated systolic dysfunction Vt-dependently. Cardiac endothelial VCAM-1 expression was increased by LPS treatment independent of MV. Cardiac edema was lowered Vt-dependently by MV, particularly after LPS, and correlated inversely with systolic myocardial function parameters ex vivo. Conclusion MV attenuated LPS-induced systolic myocardial dysfunction in a Vt-dependent manner. This was associated with a reduction in cardiac edema following a lower transmural coronary venous outflow pressure during LPS-induced coronary inflammation.

  8. Assessment of an Underwater Light Attenuation Model Using Bio-optical Data Collected in Monterey Bay, CA.

    Science.gov (United States)

    Penta, B.; Goode, W.; Blum, M.; Lamb, E.; Shulman, I.; Jolliff, J.; Anderson, S.; Derada, S.

    2008-12-01

    A new model for the underwater propagation of photosynthetically available radiation (PAR) based on inherent optical properties (IOP) has been developed for use in marine ecosystem models. This "pseudo- spectral," IOP-based model has improved accuracy compared to standard Lambert-Beer law schemes while being appreciably more computationally efficient than multi-spectral optical models. IOP input to the model can originate from an ecosystem model, remote sensing observations, in-situ data, or any combination thereof. To assess the utility of this new light model, we employ a bio-optical data set collected in Monterey Bay, California during May and June 2008 as part of the Naval Research Laboratory's Bio-Optical Studies of Predictability and Assimilation for the Coastal Environment (BIOSPACE) program. A diverse set of sampling platforms included satellites, gliders, autonomous underwater vehicles, profiling moorings (SEPTR), a ship- towed platform (ScanFish MK II), and ship-based profiling and water sampling. Predictions derived from an ecosystem model using different parameterizations of the IOP-based light scheme are compared.

  9. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Gary Mavko; Jack Dvorkin

    2002-01-01

    In Section 1 of this first report we will describe the work we are doing to collect and analyze rock physics data for the purpose of modeling seismic attenuation from other measurable quantities such as porosity, water saturation, clay content and net stress. This work and other empirical methods to be presented later, will form the basis for ''Q pseudo-well modeling'' that is a key part of this project. In Section 2 of this report, we will show the fundamentals of a new method to extract Q, dispersion, and attenuation from field seismic data. The method is called Gabor-Morlet time-frequency decomposition. This technique has a number of advantages including greater stability and better time resolution than spectral ratio methods.

  10. Inhibition of spinal UCHL1 attenuates pain facilitation in a cancer-induced bone pain model by inhibiting ubiquitin and glial activation

    Science.gov (United States)

    Cheng, Wei; Chen, Yuan-Li; Wu, Liang; Miao, Bei; Yin, Qin; Wang, Jin-Feng; Fu, Zhi-Jian

    2016-01-01

    The present study examined alterations of spinal ubiquitin C-terminal hydrolase L1 (UCHL1), ubiquitin expression and glial activation in the cancer-induced bone pain rats. Furthermore, whether inhibition of spinal UCHL1 could alleviate cancer-induced bone pain was observed. The CIBP model was established by intrathecal Walker 256 mammary gland carcinoma cells in SD rats. The rats of CIBP developed significant pain facilitation in the Von Frey test. Double immunofluorescence analyses revealed that in the spines of CIBP rats, ubiquitin co-localized with NeuN, Iba-1 or GFAP; UCHL1 and NeuN were co-expressed and UCHL1 also co-localized with ubiquitin. The CIBP model induced up-regulation of ubiquitin and UCHL1 in the spines, as well as glial activation. Inhibition of spinal UCHL1 attenuated pain facilitation by down-regulation of ubiquitin expression and glial activation. in the CIBP rats. Our data suggests that UCHL1/ubiquitin distributed and increased in the spines of CIBP rats, that glial activation also increased in the CIBP model and that inhibition of spinal UCHL1 may be an effective method to alleviate cancer-induced bone pain. PMID:27508024

  11. Infection in a rat model reactivates attenuated virulence after long-term axenic culture of Acanthamoeba spp

    OpenAIRE

    Carolina De Marco Verissimo; Vinicius Jose Maschio; Ana Paula Folmer Correa; Adriano Brandelli; Marilise Brittes Rott

    2013-01-01

    Prolonged culturing of many microorganisms leads to the loss of virulence and a reduction of their infective capacity. However, little is known about the changes in the pathogenic strains of Acanthamoeba after long culture periods. Our study evaluated the effect of prolonged culturing on the invasiveness of different isolates of Acanthamoeba in an in vivo rat model. ATCC strains of Acanthamoeba, isolates from the environment and clinical cases were evaluated. The in vivo model was effective i...

  12. Landing gear noise attenuation

    Science.gov (United States)

    Moe, Jeffrey W. (Inventor); Whitmire, Julia (Inventor); Kwan, Hwa-Wan (Inventor); Abeysinghe, Amal (Inventor)

    2011-01-01

    A landing gear noise attenuator mitigates noise generated by airframe deployable landing gear. The noise attenuator can have a first position when the landing gear is in its deployed or down position, and a second position when the landing gear is in its up or stowed position. The noise attenuator may be an inflatable fairing that does not compromise limited space constraints associated with landing gear retraction and stowage. A truck fairing mounted under a truck beam can have a compliant edge to allow for non-destructive impingement of a deflected fire during certain conditions.

  13. A novel p38α MAPK inhibitor suppresses brain proinflammatory cytokine up-regulation and attenuates synaptic dysfunction and behavioral deficits in an Alzheimer's disease mouse model

    Directory of Open Access Journals (Sweden)

    McNamara Laurie K

    2007-09-01

    Full Text Available Abstract Background An accumulating body of evidence is consistent with the hypothesis that excessive or prolonged increases in proinflammatory cytokine production by activated glia is a contributor to the progression of pathophysiology that is causally linked to synaptic dysfunction and hippocampal behavior deficits in neurodegenerative diseases such as Alzheimer's disease (AD. This raises the opportunity for the development of new classes of potentially disease-modifying therapeutics. A logical candidate CNS target is p38α MAPK, a well-established drug discovery molecular target for altering proinflammatory cytokine cascades in peripheral tissue disorders. Activated p38 MAPK is seen in human AD brain tissue and in AD-relevant animal models, and cell culture studies strongly implicate p38 MAPK in the increased production of proinflammatory cytokines by glia activated with human amyloid-beta (Aβ and other disease-relevant stressors. However, the vast majority of small molecule drugs do not have sufficient penetrance of the blood-brain barrier to allow their use as in vivo research tools or as therapeutics for neurodegenerative disorders. The goal of this study was to test the hypothesis that brain p38α MAPK is a potential in vivo target for orally bioavailable, small molecules capable of suppressing excessive cytokine production by activated glia back towards homeostasis, allowing an improvement in neurologic outcomes. Methods A novel synthetic small molecule based on a molecular scaffold used previously was designed, synthesized, and subjected to analyses to demonstrate its potential in vivo bioavailability, metabolic stability, safety and brain uptake. Testing for in vivo efficacy used an AD-relevant mouse model. Results A novel, CNS-penetrant, non-toxic, orally bioavailable, small molecule inhibitor of p38α MAPK (MW01-2-069A-SRM was developed. Oral administration of the compound at a low dose (2.5 mg/kg resulted in attenuation of

  14. Infection in a rat model reactivates attenuated virulence after long-term axenic culture of Acanthamoeba spp

    Directory of Open Access Journals (Sweden)

    Carolina De Marco Verissimo

    2013-11-01

    Full Text Available Prolonged culturing of many microorganisms leads to the loss of virulence and a reduction of their infective capacity. However, little is known about the changes in the pathogenic strains of Acanthamoeba after long culture periods. Our study evaluated the effect of prolonged culturing on the invasiveness of different isolates of Acanthamoeba in an in vivo rat model. ATCC strains of Acanthamoeba, isolates from the environment and clinical cases were evaluated. The in vivo model was effective in establishing the infection and differentiating the pathogenicity of the isolates and re-isolates. The amoebae cultured in the laboratory for long periods were less virulent than those that were recently isolated, confirming the importance of passing Acanthamoeba strains in animal models.

  15. Graphene-based Electronically Tuneable Microstrip Attenuator

    Directory of Open Access Journals (Sweden)

    L. Pierantoni

    2014-06-01

    Full Text Available This paper presents the design of a graphene- based electronically tuneable microstrip attenuator operating at a frequency of 5 GHz. The use of graphene as a variable resistor is discussed and the modelling of its electromagnetic properties at microwave frequencies is fully addressed. The design of the graphene-based attenuator is described. The structure integrates a patch of graphene, whose characteristics can range from being a fairly good conductor to a highly lossy material, depending on the applied voltage. By applying the proper voltage through two high-impedance bias lines, the surface resistivity of graphene can be modified, thereby changing the insertion loss of the microstrip attenuator.

  16. Nondestructive assay in complex, self-attenuating radioactive materials by gamma spectroscopy: A mathematical model and empirical determination of error

    Science.gov (United States)

    Soukup, James David

    2001-12-01

    Over the past several years, portable High Purity Germanium (HPGe) gamma spectroscopy systems have been used with nondestructive assay techniques to characterize waste items at Los Alamos National Laboratory (LANL) and other Department of Energy (DOE) sites. Accurate quantification of the radionuclide contamination required that an analytical model be developed. The resulting model, based on a point kernel volumetric approach, is used to translate the raw spectral information into total activity for each detected radionuclide. Using uncollimated, in situ counting techniques, a relatively high-efficiency n-type HPGe detector, a portable laptop computer, and a multi-channel analyzer, the nondestructive assay system has superior detection limits with state of-the-art accuracy. Not only can the system be used to successfully count drums, but also large items such as 90 cubic foot boxes, gloveboxes and heavy machinery. Additionally, contaminated materials such as floors, walls, soil and water have been characterized with the same model. Because of the versatility of the model and the very low detection limits attainable, tremendous cost savings have been realized from low-level/TRU waste segregation activities, and free-release/low-level determinations. The model has been used to determine the activity in a number of contaminated and spiked items and matrices with both known and unknown quantities. In an extensive study to determine the empirical accuracy of the model, a number of measurements were made on sources of known activity. The results show that measurement errors of 20 to 50 percent are achieved, depending on item size, geometry and radionuclide contamination. For larger items, results were typically 30 to 50 percent from the known value. Measurements of smaller and homogeneously contaminated items showed that the measurement errors were the same order of magnitude as the uncertainty of the source (10 to 20 percent). Furthermore, although individual error

  17. Sodium-Glucose Linked Cotransporter-2 Inhibition Does Not Attenuate Disease Progression in the Rat Remnant Kidney Model of Chronic Kidney Disease.

    Directory of Open Access Journals (Sweden)

    Yanling Zhang

    Full Text Available Pharmacological inhibition of the proximal tubular sodium-glucose linked cotransporter-2 (SGLT2 leads to glycosuria in both diabetic and non-diabetic settings. As a consequence of their ability to modulate tubuloglomerular feedback, SGLT2 inhibitors, like agents that block the renin-angiotensin system, reduce intraglomerular pressure and single nephron GFR, potentially affording renoprotection. To examine this further we administered the SGLT2 inhibitor, dapagliflozin, to 5/6 (subtotally nephrectomised rats, a model of progressive chronic kidney disease (CKD that like CKD in humans is characterised by single nephron hyperfiltration and intraglomerular hypertension and where angiotensin converting enzyme inhibitors and angiotensin receptor blockers are demonstrably beneficial. When compared with untreated rats, both sham surgery and 5/6 nephrectomised rats that had received dapagliflozin experienced substantial glycosuria. Nephrectomised rats developed hypertension, heavy proteinuria and declining GFR that was unaffected by the administration of dapagliflozin. Similarly, SGLT2 inhibition did not attenuate the extent of glomerulosclerosis, tubulointerstitial fibrosis or overexpression of the profibrotic cytokine, transforming growth factor-ß1 mRNA in the kidneys of 5/6 nephrectomised rats. While not precluding beneficial effects in the diabetic setting, these findings indicate that SGLT2 inhibition does not have renoprotective effects in this classical model of progressive non-diabetic CKD.

  18. Confronting the EPOS-LHC model predictions on the charged particle and muon attenuation lengths of EAS with the measurements of the KASCADE-Grande observatory

    Directory of Open Access Journals (Sweden)

    Arteaga-Velázquez J.C.

    2015-01-01

    Full Text Available KASCADE-Grande was an air-shower experiment designed to study cosmic rays between 1016 and 1018 eV. The instrument was located at the site of the Karlsruhe Institute of Technology, Germany at an altitude of 110 m a.s.l. and covered an area of 0.5 km2. KASCADE-Grande consisted of several detector systems dedicated to measure different components of the EAS generated by the primary cosmic rays, i.e., the muon and the electron contents of the air-shower. With such a number of EAS observables and the precision of the measurements, the KASCADE-Grande data can be used to not only study in detail the properties of cosmic rays but also to test the predictions of hadronic-interaction models. In this work, in particular, the attenuation lengths of the muon number and the charged number of particles of EAS in the atmosphere were extracted from the KASCADE-Grande data and the results were compared with the predictions of the new EPOS-LHC hadronic-interaction model.

  19. Pre-Conditioning with CDP-Choline Attenuates Oxidative Stress-Induced Cardiac Myocyte Death in a Hypoxia/Reperfusion Model

    Directory of Open Access Journals (Sweden)

    Héctor González-Pacheco

    2014-01-01

    Full Text Available Background. CDP-choline is a key intermediate in the biosynthesis of phosphatidylcholine, which is an essential component of cellular membranes, and a cell signalling mediator. CDP-choline has been used for the treatment of cerebral ischaemia, showing beneficial effects. However, its potential benefit for the treatment of myocardial ischaemia has not been explored yet. Aim. In the present work, we aimed to evaluate the potential use of CDP-choline as a cardioprotector in an in vitro model of ischaemia/reperfusion injury. Methods. Neonatal rat cardiac myocytes were isolated and subjected to hypoxia/reperfusion using the coverslip hypoxia model. To evaluate the effect of CDP-choline on oxidative stress-induced reperfusion injury, the cells were incubated with H2O2 during reperfusion. The effect of CDP-choline pre- and postconditioning was evaluated using the cell viability MTT assay, and the proportion of apoptotic and necrotic cells was analyzed using the Annexin V determination by flow cytometry. Results. Pre- and postconditioning with 50 mg/mL of CDP-choline induced a significant reduction of cells undergoing apoptosis after hypoxia/reperfusion. Preconditioning with CDP-choline attenuated postreperfusion cell death induced by oxidative stress. Conclusion. CDP-choline administration reduces cell apoptosis induced by oxidative stress after hypoxia/reperfusion of cardiac myocytes. Thus, it has a potential as cardioprotector in ischaemia/reperfusion-injured cardiomyocytes.

  20. Early post-stressor intervention with minocycline, a second-generation tetracycline, attenuates post-traumatic stress response in an animal model of PTSD.

    Science.gov (United States)

    Levkovitz, Yechiel; Fenchel, Daphna; Kaplan, Zeev; Zohar, Joseph; Cohen, Hagit

    2015-01-01

    We assessed the effects of minocycline, a tetracycline with anti-inflammatory, anti-apoptotic and neuroprotective capacities, in an animal model of post-traumatic stress disorder (PTSD). Rats were exposed to psychogenic stress and treated 1h later with minocycline or saline. Behavioral measures included the elevated plus-maze (EPM) and acoustic startle response (ASR) 7 days post stress-exposure. One day after behavioral testing, animals were exposed to a trauma cue and freezing response was assessed. Local levels of cytokines interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the hippocampus, frontal cortex (FC) and hypothalamus were then examined. Minocycline attenuated anxious-like behaviors in stress-exposed rats. In addition, decreased levels of cytokines were measured in exposed rats treated with minocycline compared to their counterparts treated with saline. This study suggests a potential use of minocycline in preventing physiological and behavioral alternations resulting from acute exposure to psychological stress. As this is the first study to report beneficial outcomes for minocycline treatment in an animal model of PTSD, further investigations of the use of minocycline in stress-related conditions with emphasis on PTSD is needed. PMID:25487770

  1. Sodium-Glucose Linked Cotransporter-2 Inhibition Does Not Attenuate Disease Progression in the Rat Remnant Kidney Model of Chronic Kidney Disease

    Science.gov (United States)

    Zhang, Yanling; Thai, Kerri; Kepecs, David M.; Gilbert, Richard E.

    2016-01-01

    Pharmacological inhibition of the proximal tubular sodium-glucose linked cotransporter-2 (SGLT2) leads to glycosuria in both diabetic and non-diabetic settings. As a consequence of their ability to modulate tubuloglomerular feedback, SGLT2 inhibitors, like agents that block the renin-angiotensin system, reduce intraglomerular pressure and single nephron GFR, potentially affording renoprotection. To examine this further we administered the SGLT2 inhibitor, dapagliflozin, to 5/6 (subtotally) nephrectomised rats, a model of progressive chronic kidney disease (CKD) that like CKD in humans is characterised by single nephron hyperfiltration and intraglomerular hypertension and where angiotensin converting enzyme inhibitors and angiotensin receptor blockers are demonstrably beneficial. When compared with untreated rats, both sham surgery and 5/6 nephrectomised rats that had received dapagliflozin experienced substantial glycosuria. Nephrectomised rats developed hypertension, heavy proteinuria and declining GFR that was unaffected by the administration of dapagliflozin. Similarly, SGLT2 inhibition did not attenuate the extent of glomerulosclerosis, tubulointerstitial fibrosis or overexpression of the profibrotic cytokine, transforming growth factor-ß1 mRNA in the kidneys of 5/6 nephrectomised rats. While not precluding beneficial effects in the diabetic setting, these findings indicate that SGLT2 inhibition does not have renoprotective effects in this classical model of progressive non-diabetic CKD. PMID:26741142

  2. A model of gender prejudice, power, and discrimination: How hierarchy-enhancing factors predominate over hierarchy-attenuating factors

    OpenAIRE

    Kleinlogel E. P.; Dietz J; Faniko, K. (ed.); Lorenzi-Cioldi, F. (ed.); Sarrasin, O. (ed.); Mayor, E. (ed.)

    2015-01-01

    Gender inequalities remain an issue in our society and particularly in the workplace. Several factors can explain this gender difference in top-level managerial positions such as career ambitions but also biases against women. In our chapter, we propose a model explaining why gender inequalities and particularly discrimination against women is still present in our societies despite social norms and existing legislation on gender equality. To this purpose, we review research on discrimination ...

  3. Focal axonal swellings and associated ultrastructural changes attenuate conduction velocity in central nervous system axons: a computer modeling study

    OpenAIRE

    Kolaric, Katarina V; Thomson, Gemma; Edgar, Julia M; Brown, Angus M.

    2013-01-01

    The constancy of action potential conduction in the central nervous system (CNS) relies on uniform axon diameter coupled with fidelity of the overlying myelin providing high-resistance, low capacitance insulation. Whereas the effects of demyelination on conduction have been extensively studied/modeled, equivalent studies on the repercussions for conduction of axon swelling, a common early pathological feature of (potentially reversible) axonal injury, are lacking. The recent description of ex...

  4. FLLL31, a derivative of curcumin, attenuates airway inflammation in a multi-allergen challenged mouse model.

    Science.gov (United States)

    Yuan, Shaopeng; Cao, Shuhua; Jiang, Rentao; Liu, Renping; Bai, Jinye; Hou, Qi

    2014-07-01

    Signal transducer and activator of transcription protein 3 (STAT3), one of the major regulators of inflammation, plays multiple roles in cellular transcription, differentiation, proliferation, and survival in human diseases. Dysregulation of STAT3 is related to the severe airway inflammation associated with asthma. FLLL31 is a newly developed compound based on the herbal medicine curcumin, which specifically suppresses the activation of STAT3. However, the function of FLLL31 on inflammatory diseases, especially on the regulation of airway inflammation, has not been fully studied. In our prior investigations, we developed a mouse model that was challenged with a mixture of DRA allergens (including house dust mite, ragweed, and Aspergillums species) to mimic the severe airway inflammation observed in human patients. In this study, we performed a series of experiments on the inflammatory regulation activities of FLLL31 in both in vitro cultured cells and our in vivo DRA-challenged mouse model. Our results show that FLLL31 exhibits anti-inflammatory effects on macrophage activation, lymphocyte differentiation, and pro-inflammatory factor production. Importantly, FLLL31 significantly inhibited airway inflammation and recruitment of inflammatory cells in the DRA-challenged mouse model. Based on these results, we conclude that FLLL31 is a potential therapeutic agent that can be used against severe airway inflammation diseases. PMID:24819716

  5. Seismic Attenuation Inversion with t* Using tstarTomog.

    Energy Technology Data Exchange (ETDEWEB)

    Preston, Leiph

    2014-09-01

    Seismic attenuation is defined as the loss of the seismic wave amplitude as the wave propagates excluding losses strictly due to geometric spreading. Information gleaned from seismic waves can be utilized to solve for the attenuation properties of the earth. One method of solving for earth attenuation properties is called t*. This report will start by introducing the basic theory behind t* and delve into inverse theory as it pertains to how the algorithm called tstarTomog inverts for attenuation properties using t* observations. This report also describes how to use the tstarTomog package to go from observed data to a 3-D model of attenuation structure in the earth.

  6. Specific allergen immunotherapy attenuates allergic airway inflammation in a rat model of Alstonia scholaris pollen induced airway allergy.

    Science.gov (United States)

    Datta, Ankur; Moitra, Saibal; Hazra, Iman; Mondal, Somnath; Das, Prasanta Kumar; Singh, Manoj Kumar; Chaudhuri, Suhnrita; Bhattacharya, Debanjan; Tripathi, Santanu Kumar; Chaudhuri, Swapna

    2016-01-01

    Pollen grains are well established to be an important cause of respiratory allergy. Current pharmacologic therapies for allergic asthma do not cure the disease. Allergen specific immunotherapy is the only treatment method which re-directs the immune system away from allergic response leading to a long lasting effect. The mechanism by which immunotherapy achieves this goal is an area of active research world-wide. The present experimental study was designed to develop an experimental model of allergic lung inflammation based on a relevant human allergen, Alstonia scholaris pollen, and to establish the immunological and cellular features of specific allergen immunotherapy using this same pollen extract. Our results revealed that Alstonia scholaris pollen sensitization and challenge causes eosinophilic airway inflammation with mucin hypersecretion. This is associated with increased total IgE, increased expression of FcɛRI on lung mast cells and increased levels of IL-4, IL-5 & IL-13 as confirmed by ELISA, in-situ immunofluorescence and FACS assay. Allergen specific immunotherapy reduced airway inflammation and also decreased total IgE level, FcɛRI expression, IL-4, IL-5 & IL-13 levels. It was further noted that the reduction of these levels was more by intra-nasal route than by intra-peritoneal route. Thus we present a novel animal model of Alstonia scholaris pollen allergic disease and specific allergen immunotherapy which will pave the way towards the development of better treatment modalities. PMID:26667977

  7. In vivo efficacy of trans-cinnamaldehyde, carvacrol, and thymol in attenuating Listeria monocytogenes infection in a Galleria mellonella model.

    Science.gov (United States)

    Upadhyay, Abhinav; Venkitanarayanan, Kumar

    2016-07-01

    Listeria monocytogenes is a major foodborne pathogen that causes life-threatening illnesses in humans. With emergence of antibiotic resistance in L. monocytogenes, there is considerable interest in testing the efficacy of alternative therapies for controlling listeriosis in humans. This study investigated the efficacy of three phytochemicals, namely trans-cinnamaldehyde (TC), carvacrol (CR), and thymol (TY) in reducing L. monocytogenes virulence in the recently established invertebrate model, Galleria mellonella. In addition, the effect of phytochemicals on the transcription of antimicrobial peptide genes in G. mellonella (responsible for host defense) was investigated using real-time quantitative polymerase chain reaction. G. mellonella larvae were inoculated with L. monocytogenes (10(5) CFU/larvae) either with or without the subinhibitory concentration (chemical concentration not inhibiting bacterial growth) of phytochemicals. The larvae were incubated at 37 °C for 5 days, and their mortality was scored at 24-h intervals. The transcriptional response of the defense genes was studied in inoculated and uninoculated larvae at 6 h post challenge. The experiments were repeated at least six times with replicates. All phytochemicals enhanced the survival rates of G. mellonella infected with lethal doses of L. monocytogenes (P monocytogenes (P < 0.05). Results suggest that TC, CR, and TY could potentially be used to control listeriosis. Further investigation in an appropriate mammalian model is warranted. PMID:27094514

  8. Eugenol in combination with lactic acid bacteria attenuates Listeria monocytogenes virulence in vitro and in invertebrate model Galleria mellonella.

    Science.gov (United States)

    Upadhyay, Abhinav; Upadhyaya, Indu; Mooyottu, Shankumar; Venkitanarayanan, Kumar

    2016-06-01

    Listeria monocytogenes is a human enteric pathogen that causes severe foodborne illness in high-risk populations. Crossing the intestinal barrier is the first critical step for Listeria monocytogenes infection. Therefore, reducing L. monocytogenes colonization and invasion of intestinal epithelium and production of virulence factors could potentially control listeriosis in humans. This study investigated the efficacy of sub-inhibitory concentration (SIC) of the plant-derived antimicrobial eugenol, either alone, or in combination with five lactic acid bacteria (LAB), namely Bifidobacterium bifidum (NRRL-B41410), Lactobacillus reuteri (B-14172), Lactobacillus fermentum (B-1840), Lactobacillus plantarum (B-4496) and Lactococcus lactis subspecies lactis (B-633) in reducing Listeria monocytogenes adhesion to and invasion of human intestinal epithelial cells (Caco-2). Additionally, the effect of the aforementioned treatments on Listeria monocytogenes listeriolysin production, epithelial E-cadherin binding and expression of virulence genes was investigated. Moreover, the in vivo efficacy of eugenol-LAB treatments in reducing Listeria monocytogenes virulence in the invertebrate model Galleria mellonella was studied. Eugenol and LAB, either alone or in combination, significantly reduced Listeria monocytogenes adhesion to and invasion of intestinal cells (P eugenol-LAB treatments decreased Listeria monocytogenes haemolysin production, E-cadherin binding and virulence gene expression (P eugenol-LAB treatments significantly enhanced the survival rates of G. mellonella infected with lethal doses of Listeria monocytogenes (P eugenol either alone or in combination with LAB, and justify further investigations in a mammalian model. PMID:27002648

  9. Specific allergen immunotherapy attenuates allergic airway inflammation in a rat model of Alstonia scholaris pollen induced airway allergy.

    Science.gov (United States)

    Datta, Ankur; Moitra, Saibal; Hazra, Iman; Mondal, Somnath; Das, Prasanta Kumar; Singh, Manoj Kumar; Chaudhuri, Suhnrita; Bhattacharya, Debanjan; Tripathi, Santanu Kumar; Chaudhuri, Swapna

    2016-01-01

    Pollen grains are well established to be an important cause of respiratory allergy. Current pharmacologic therapies for allergic asthma do not cure the disease. Allergen specific immunotherapy is the only treatment method which re-directs the immune system away from allergic response leading to a long lasting effect. The mechanism by which immunotherapy achieves this goal is an area of active research world-wide. The present experimental study was designed to develop an experimental model of allergic lung inflammation based on a relevant human allergen, Alstonia scholaris pollen, and to establish the immunological and cellular features of specific allergen immunotherapy using this same pollen extract. Our results revealed that Alstonia scholaris pollen sensitization and challenge causes eosinophilic airway inflammation with mucin hypersecretion. This is associated with increased total IgE, increased expression of FcɛRI on lung mast cells and increased levels of IL-4, IL-5 & IL-13 as confirmed by ELISA, in-situ immunofluorescence and FACS assay. Allergen specific immunotherapy reduced airway inflammation and also decreased total IgE level, FcɛRI expression, IL-4, IL-5 & IL-13 levels. It was further noted that the reduction of these levels was more by intra-nasal route than by intra-peritoneal route. Thus we present a novel animal model of Alstonia scholaris pollen allergic disease and specific allergen immunotherapy which will pave the way towards the development of better treatment modalities.

  10. Safranal of Crocus sativus L. inhibits inducible nitric oxide synthase and attenuates asthma in a mouse model of asthma.

    Science.gov (United States)

    Bukhari, Syed Imran; Pattnaik, Bijay; Rayees, Sheikh; Kaul, Sanjana; Dhar, Manoj K

    2015-04-01

    The present study involves evaluation of antioxidant potential of Crocus sativus and its main constituents, safranal (SFN) and crocin (CRO), in bronchial epithelial cells, followed antiinflammatory potential of the active constituent safranal, in a murine model of asthma. To investigate the antioxidizing potential of Crocus sativus and its main constituents in bronchial epithelial cells, the stress was induced in these cells by a combination of different cytokines that resulted in an increase in nitric oxide production (NO), induced nitric oxide synthase (iNOS) levels, peroxynitrite ion generation, and cytochrome c release. Treatment with saffron and its constituents safranal and crocin resulted in a decrease of NO, iNOS levels, peroxynitrite ion generation, and prevented cytochrome c release. However, safranal significantly reduced oxidative stress in bronchial epithelial cells via iNOS reduction besides preventing apoptosis in these cells. In the murine model of asthma study, antiinflammatory role of safranal was characterized by increased airway hyper-responsiveness, airway cellular infiltration, and epithelial cell injury. Safranal pretreatment to these allergically inflamed mice lead to a significant decrease in airway hyper-responsiveness and airway cellular infiltration to the lungs. It also reduced iNOS production, bronchial epithelial cell apoptosis, and Th2 type cytokine production in the lungs.

  11. Field-scale model for the natural attenuation of uranium at the Hanford 300 Area using high-performance computing

    Science.gov (United States)

    Hammond, Glenn E.; Lichtner, Peter C.

    2010-09-01

    High-resolution, three-dimensional, reactive flow and transport simulations are carried out to describe the migration of hexavalent uranium [U(VI)] at the Hanford 300 Area bordering the Columbia River and to better understand the persistence of the uranium plume at the site. The computer code PFLOTRAN developed under a DOE SciDAC-2 project is employed in the simulations that are executed on ORNL's Cray XT4/XT5 supercomputer Jaguar. The conceptual model used in the simulations is based on the recognition of three distinct phases or time periods in the evolution of the U(VI) plume. These correspond to (1) initial waste emplacement; (2) initial presence of both labile and nonlabile U(VI) with an evolved U(VI) plume extending from the source region to the river boundary, representing present-day conditions; and (3) the complete removal of all nonlabile U(VI) and labile U(VI) in the vadose zone. This work focuses primarily on modeling Phase II using equilibrium and multirate sorption models for labile U(VI) and a continuous source release of nonlabile U(VI) in the South Process Pond through dissolution of metatorbernite as a surrogate mineral. For this case, rapid fluctuations in the Columbia River stage combined with the slow release of nonlabile U(VI) from contaminated sediment are found to play a predominant role in determining the migration behavior of U(VI) with sorption only a second-order effect. Nevertheless, a multirate model was essential in explaining breakthrough curves obtained from laboratory column experiments using the same sediment and is demonstrated to be important in Phase III. The calculations demonstrate that U(VI) is discharged to the river at a highly fluctuating rate in a ratchet-like behavior as the river stage rises and falls. The high-frequency fluctuations must be resolved in the model to calculate the flux of U(VI) at the river boundary. By time averaging the instantaneous flux to average out noise superimposed on the river stage

  12. Icariin attenuates glucocorticoid insensitivity mediated by repeated psychosocial stress on an ovalbumin-induced murine model of asthma.

    Science.gov (United States)

    Li, Bei; Duan, Xiaohong; Xu, Changqing; Wu, Jinfeng; Liu, Baojun; Du, Yiji; Luo, Qingli; Jin, Hualiang; Gong, Weiyi; Dong, Jingcheng

    2014-04-01

    Evidence shows that psychosocial stress exacerbates asthma, but there is little intervention to alleviate negative effects of psychosocial stress on asthma. We investigated the role of icariin in anti-inflammation and anti-anxiety potential in a murine model combined psychosocial stress with allergic exposure. The results indicated that icariin administered remarkable increased activity in the center of the open field, reversed airway hyperresponsivenesss, reduced inflammatory cytokine infiltration to the lung and whole body and also in part recovered glucocorticoid responsiveness. Furthermore, our data also showed that icariin significantly inhibited increases of corticosterone and markedly increased glucocorticoid receptor mRNA and protein expression in the lungs of mice exposed to both stress and allergen. Collectively, we speculate that inducing glucocorticoid receptor modulation might be the potential mechanisms of icariin to facilitate corticosteroid responsiveness of cytokine production.

  13. Activation of angiotensin-converting enzyme 2 (ACE2) attenuates allergic airway inflammation in rat asthma model.

    Science.gov (United States)

    Dhawale, Vaibhav Shrirang; Amara, Venkateswara Rao; Karpe, Pinakin Arun; Malek, Vajir; Patel, Deep; Tikoo, Kulbhushan

    2016-09-01

    Angiotensin-I converting enzyme (ACE) is positively correlated to asthma, chronic obstructive pulmonary disease (COPD), acute respiratory distress syndrome (ARDS) and is highly expressed in lungs. ACE2, the counteracting enzyme of ACE, was proven to be protective in pulmonary, cardiovascular diseases. In the present study we checked the effect of ACE2 activation in animal model of asthma. Asthma was induced in male wistar rats by sensitization and challenge with ovalbumin and then treated with ACE2 activator, diminazene aceturate (DIZE) for 2weeks. 48h after last allergen challenge, animals were anesthetized, blood, BALF, femoral bone marrow lavage were collected for leucocyte count; trachea for measuring airway responsiveness to carbachol; lungs and heart were isolated for histological studies and western blotting. In our animal model, the characteristic features of asthma such as altered airway responsiveness to carbachol, eosinophilia and neutrophilia were observed. Western blotting revealed the increased pulmonary expression of ACE1, IL-1β, IL-4, NF-κB, BCL2, p-AKT, p-p38 and decreased expression of ACE2 and IκB. DIZE treatment prevented these alterations. Intraalveolar interstitial thickening, inflammatory cell infiltration, interstitial fibrosis, oxidative stress and right ventricular hypertrophy in asthma control animals were also reversed by DIZE treatment. Activation of ACE2 by DIZE conferred protection against asthma as evident from biochemical, functional, histological and molecular parameters. To the best of our knowledge, we report for the first time that activation of ACE2 by DIZE prevents asthma progression by altering AKT, p38, NF-κB and other inflammatory markers. PMID:27343405

  14. Systemic administration of Rosmarinus officinalis attenuates the inflammatory response induced by carrageenan in the mouse model of pleurisy.

    Science.gov (United States)

    da Rosa, Julia Salvan; Facchin, Bruno Matheus; Bastos, Juliana; Siqueira, Mariana Araújo; Micke, Gustavo Amadeu; Dalmarco, Eduardo Monguilhott; Pizzolatti, Moacir Geraldo; Fröde, Tânia Silvia

    2013-11-01

    Rosmarinus officinalis, also named rosemary, is a native plant from the Mediterranean region that is useful for the treatment of inflammatory diseases. Studies using experimental models and/or in vitro tests have shown the important biological effects of rosemary. In this context, the mechanism of the anti-inflammatory activity of rosemary must be investigated to support the discovery of new substances with anti-inflammatory effects. The aim of the present study was to investigate the anti-inflammatory effects of crude extract oil free obtained from the leaves of rosemary in an animal model of inflammation, thus evaluating its medicinal use for the treatment of inflammatory conditions. Also its ethanol, hexane, and ethyl acetate fractions, as well as its isolated compounds carnosol and rosmarinic acid were analyzed. Swiss mice were used for the in vivo experiments. The effect of this herb on the inhibition of the leukocytes, exudation, myeloperoxidase, and adenosine-deaminase activities, nitrite/nitrate, interleukin 17A, and interleukin 10 levels and mRNA expression was determined. The crude extract and its derived fractions, in addition to its isolated compounds, inhibited leukocytes and decreased exudation and myeloperoxidase and adenosine-deaminase activities, as well as nitrite/nitrate and interleukin 17A levels and mRNA expression, besides increasing interleukin 10 levels and mRNA expression. Rosemary showed important anti-inflammatory activity by inhibiting leukocytes and decreasing exudation. These effects were associated with a decrease in the proinflammatory parameters (myeloperoxidase, adenosine-deaminase, nitrite/nitrate, and interleukin 17A) and an increase in the anti-inflammatory cytokine (interleukin 10). This study confirms the anti-inflammatory properties of rosemary and validates its use in folk medicine to treat inflammatory diseases such as rheumatism and asthma. PMID:24288274

  15. Clonorchis sinensis-derived total protein attenuates airway inflammation in murine asthma model by inducing regulatory T cells and modulating dendritic cell functions

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Young-Il [Div. of Malaria and Parasitic Diseases, Korea Centers for Disease Control and Prevention, Osong (Korea, Republic of); Kim, Seung Hyun [Div. of AIDS, National Institute of Health, Korea Centers for Disease Control and Prevention, Osong (Korea, Republic of); Ju, Jung Won; Cho, Shin Hyeong; Lee, Won Ja [Div. of Malaria and Parasitic Diseases, Korea Centers for Disease Control and Prevention, Osong (Korea, Republic of); Park, Jin Wook; Park, Yeong-Min [Dept. of Microbiology and Immunology, College of Medicine, Pusan National University, Yang-San (Korea, Republic of); Lee, Sang Eun, E-mail: ondalgl@cdc.go.kr [Div. of Malaria and Parasitic Diseases, Korea Centers for Disease Control and Prevention, Osong (Korea, Republic of)

    2011-04-22

    Highlights: {yields} Treatment with Clonorchis sinensis-derived total protein attenuates OVA-induced airway inflammation and AHR to methacholine. {yields} Induction of CD4{sup +}CD25{sup +}Foxp3{sup +} T cells and IL-10 along with suppression of splenocyte proliferation by C. sinensis-derived total protein. {yields} C. sinensis-derived total protein interferes with the expression of co-stimulatory molecules in DCs. -- Abstract: Asthma is characterized by Th2-mediated inflammation, resulting in airway hyperresponsiveness (AHR) through airway remodeling. Recent epidemiological and experimental reports have suggested an inverse relationship between the development of allergy and helminth infections. Infection by Clonorchis sinensis, a liver fluke that resides in the bile duct of humans, is endemic predominantly in Asia including Korea and China. Using a murine model for asthma, we investigated the effects of C. sinensis-derived total protein (Cs-TP) on allergen-induced airway inflammation and the mechanism underlying the protective effects of Cs-TP administration on asthma. Treatment with Cs-TP attenuated OVA-induced airway inflammation and methacholine-induced AHR, as well as eosinophilia development, lymphocyte infiltration into the lung, and goblet cell metaplasia. This protective effect of Cs-TP is associated with markedly reduced OVA-specific IgE and Th1/Th2 cytokine production. Moreover, Cs-TP increased the number of CD4{sup +}CD25{sup +}Foxp3{sup +} regulatory T (Treg) cells as well as their suppressive activity. In fact, proliferation of OVA-restimulated splenocytes was suppressed significantly. Cs-TP also inhibited the expression of such co-stimulatory molecules as CD80, CD86, and CD40 in LPS- or OVA-stimulated dendritic cells (DCs), suggesting that Cs-TP could interfere with the capacity of airway DCs to prime naive T cells. These data demonstrate the capacity of C. sinensis to ameliorate allergic asthma and broaden our understanding of the paradoxical

  16. Oral infection with the Salmonella enterica serovar Gallinarum 9R attenuated live vaccine as a model to characterise immunity to fowl typhoid in the chicken

    Directory of Open Access Journals (Sweden)

    Beal Richard

    2005-09-01

    Full Text Available Abstract Background Salmonella enterica serovar Gallinarum (S. Gallinarum is the causative agent of fowl typhoid, a severe systemic disease of chickens that results in high mortality amongst infected flocks. Due to its virulence, the immune response to S. Gallinarum is poorly characterised. In this study we have utilised infection by the live attenuated S. Gallinarum 9R vaccine strain in inbred chickens to characterise humoral, cellular and cytokine responses to systemic salmonellosis. Results Infection with 9R results in a mild systemic infection. Bacterial clearance at three weeks post infection coincides with increases in circulating anti-Salmonella antibodies, increased T cell proliferation to Salmonella challenge and increased expression of interferon gamma. These responses peak at four weeks post infection, then decline. Only modest increases of expression of the pro-inflammatory cytokine interleukin-1β were detected early in the infection. Conclusion Infection of chickens with the 9R vaccine strain induces a mild form of systemic salmonellosis. This induces both cellular and humoral immune responses, which peak soon after bacterial clearance. Unlike enteric-associated Salmonella infections the immune response is not prolonged, reflecting the absence of persistence of Salmonella in the gastrointestinal tract. The findings here indicate that the use of the S. Gallinarum 9R vaccine strain is an effective model to study immunity to systemic salmonellosis in the chicken and may be employed in further studies to determine which components of the immune response are needed for protection.

  17. Asiaticoside: attenuation of neurotoxicity induced by MPTP in a rat model of Parkinsonism via maintaining redox balance and up-regulating the ratio of Bcl-2/Bax.

    Science.gov (United States)

    Xu, Chang-Liang; Wang, Qi-Zhi; Sun, Ling-Mei; Li, Xiu-Min; Deng, Ji-Min; Li, Lu-Fan; Zhang, Jin; Xu, Rong; Ma, Shi-Ping

    2012-01-01

    In this study, we investigated the neuroprotective effects of asiaticoside, a triterpenoid saponin isolated from the Chinese medicinal herb Centella asiatica, in the rats model of Parkinsonism induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Rats were first injected with MPTP. One day after surgery, asiaticoside was administered and the behavioral tests were assessed. On 14th day, the rats were sacrificed, substantia nigra (SN) and striatum were dissected, and then dopamine (DA) and its metabolites in striatum and malonyldialdehyde (MDA) contents, reduced glutathione (GSH) level and gene expression level in SN were estimated. Treatment with asiaticoside was found to protect dopaminergic neuron by antagonizing MPTP induced neurotoxicity and to improve locomotor dysfunction. Asiaticoside significantly attenuated the MPTP-induced reduction of dopamine in the striatum. The content of MDA was significantly decreased while the GSH level was significantly increased in asiaticoside-treated groups. In addition, asiaticoside increased the Bcl-2/Bax ratio. These results indicated that asiaticoside was effective in reversing MPTP induced Parkinsonism via its neuroprotective effects including antioxidant activity, maintaining the metabolic balance of DA, and increasing ratio of Bcl-2/Bax.

  18. Repeated administration of almonds increases brain acetylcholine levels and enhances memory function in healthy rats while attenuates memory deficits in animal model of amnesia.

    Science.gov (United States)

    Batool, Zehra; Sadir, Sadia; Liaquat, Laraib; Tabassum, Saiqa; Madiha, Syeda; Rafiq, Sahar; Tariq, Sumayya; Batool, Tuba Sharf; Saleem, Sadia; Naqvi, Fizza; Perveen, Tahira; Haider, Saida

    2016-01-01

    Dietary nutrients may play a vital role in protecting the brain from age-related memory dysfunction and neurodegenerative diseases. Tree nuts including almonds have shown potential to combat age-associated brain dysfunction. These nuts are an important source of essential nutrients, such as tocopherol, folate, mono- and poly-unsaturated fatty acids, and polyphenols. These components have shown promise as possible dietary supplements to prevent or delay the onset of age-associated cognitive dysfunction. This study investigated possible protective potential of almond against scopolamine induced amnesia in rats. The present study also investigated a role of acetylcholine in almond induced memory enhancement. Rats in test group were orally administrated with almond suspension (400 mg/kg/day) for four weeks. Both control and almond-treated rats were then divided into saline and scopolamine injected groups. Rats in the scopolamine group were injected with scopolamine (0.5 mg/kg) five minutes before the start of each memory test. Memory was assessed by elevated plus maze (EPM), Morris water maze (MWM) and novel object recognition (NOR) task. Cholinergic function was determined in terms of hippocampal and frontal cortical acetylcholine content and acetylcholinesterase activity. Results of the present study suggest that almond administration for 28 days significantly improved memory retention. This memory enhancing effect of almond was also observed in scopolamine induced amnesia model. Present study also suggests a role of acetylcholine in the attenuation of scopolamine induced amnesia by almond. PMID:26548495

  19. Topical application of a G-Quartet aptamer targeting nucleolin attenuates choroidal neovascularization in a model of age-related macular degeneration.

    Science.gov (United States)

    Leaderer, Derek; Cashman, Siobhan M; Kumar-Singh, Rajendra

    2015-11-01

    Choroidal neovascularization (CNV) associated with the 'wet' form of age related macular degeneration (AMD) is one of the most common causes of central vision loss among the elderly. The 'wet' form of AMD is currently treated by intravitreal delivery of anti-VEGF agents. However, intravitreal injections are associated with complications and long-term inhibition of VEGF leads to macular atrophy. Thus, there is currently an unmet need for the development of therapies for CNV that target molecules other than VEGF. Here, we describe nucleolin as a novel target for the 'wet' form of AMD. Nucleolin was found on the surface of endothelial cells that migrate from the choroid into the subretinal space in the laser-induced model of 'wet' AMD. AS1411 is a previously described G-quartet oligonucleotide that has been shown to bind nucleolin. We found that AS1411 inhibited the formation of tubes by human umbilical vein endothelial cells (HUVECs) by approximately 27.4% in vitro. AS1411 co-localized with the site of laser induced CNV in vivo. Intravitreally injected AS1411 inhibited laser-induced CNV by 37.6% and attenuated infiltration of macrophages by 40.3%. Finally, topical application of AS1411 led to a 43.4% reduction in CNV. Our observations have potential implications for the development of therapies for CNV and specifically for the 'wet' form of AMD. PMID:26368850

  20. N(1)-(quinolin-2-ylmethyl)butane-1,4-diamine, a polyamine analogue, attenuated injury in in vitro and in vivo models of cerebral ischemia.

    Science.gov (United States)

    Cen, Juan; Liu, Lu; He, Ling; Liu, Man; Wang, Chao-Jie; Ji, Bian-Sheng

    2012-11-01

    It has been widely recognized that glutamate (Glu)-induced cytotoxicity, intracellular calcium overload and excessive free radical production are the key players in the development and progression of ischemic brain injury. Since MK-801, an antagonist of N-methyl-d-aspartate (NMDA) receptor, showed many adverse reactions that hampered its clinical applications, development of safe and effective agent for the treatment of cerebral ischemia is eagerly required. This study was to investigate the effects of N(1)-(quinolin-2-ylmethyl)butane-1,4-diamine (QMA), a polyamine analogue, on the in vitro and in vivo models of cerebral ischemic damage. The results revealed that pretreatment with QMA could attenuate Glu, putrescine (Put) and oxygen-glucose deprivation (OGD)-induced cell death, lipid peroxidation as well as the elevation of reactive oxygen species (ROS) and intracellular [Ca(2+)](i) in pheochromocytoma (PC12) cells and in rat primary cortical neurons. The results also demonstrated that QMA could inhibit NMDA-mediated intracellular [Ca(2+)](i) accumulation in rat primary cortical neurons and reduce brain infarct volume in middle cerebral artery occlusion (MCAO) rats. The present report suggested that polyamines played a crucial role in the pathological processes of cerebral ischemic damage and that QMA or other novel polyamine analogues could be promising therapeutic candidates for stroke by virtue of their anti-hypoxia and antioxidation property.

  1. Hydrogen sulfide attenuates spatial memory impairment and hippocampal neuroinflammation in beta-amyloid rat model of Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Xuan Aiguo

    2012-08-01

    Full Text Available Abstract Background Endogenously produced hydrogen sulfide (H2S may have multiple functions in brain. An increasing number of studies have demonstrated its anti-inflammatory effects. In the present study, we investigated the effect of sodium hydrosulfide (NaHS, a H2S donor on cognitive impairment and neuroinflammatory changes induced by injections of Amyloid-β1-40 (Aβ1-40, and explored possible mechanisms of action. Methods We injected Aβ1-40 into the hippocampus of rats to mimic rat model of Alzheimer’s disease (AD. Morris water maze was used to detect the cognitive function. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL assay was performed to detect neuronal apoptosis. Immunohistochemistry analyzed the response of glia. The expression of interleukin (IL-1β and tumor necrosis factor (TNF-α was measured by enzyme-linked immunosorbent assay (ELISA and quantitative real-time polymerase chain reaction (qRT-PCR. The expression of Aβ1-40, phospho-p38 mitogen-activated protein kinase (MAPK, phospho-p65 Nuclear factor (NF-κB, and phospho-c-Jun N-terminal Kinase (JNK was analyzed by western blot. Results We demonstrated that pretreatment with NaHS ameliorated learning and memory deficits in an Aβ1-40 rat model of AD. NaHS treatment suppressed Aβ1-40-induced apoptosis in the CA1 subfield of the hippocampus. Moreover, the over-expression in IL-1β and TNF-α as well as the extensive astrogliosis and microgliosis in the hippocampus induced by Aβ1-40 were significantly reduced following administration of NaHS. Concomitantly, treatment with NaHS alleviated the levels of p38 MAPK and p65 NF-κB phosphorylation but not JNK phosphorylation that occurred in the Aβ1-40-injected hippocampus. Conclusions These results indicate that NaHS could significantly ameliorate Aβ1-40-induced spatial learning and memory impairment, apoptosis, and neuroinflammation at least in part via the inhibition of p38 MAPK and p65 NF

  2. Hippophae salicifolia D.Don berries attenuate cerebral ischemia reperfusion injury in a rat model of middle cerebral artery occlusion

    Institute of Scientific and Technical Information of China (English)

    Santhrani Thakur; Pradeepthi Chilikuri; Bindu Pulugurtha; Lavanya Yaidikar

    2015-01-01

    Objective: To investigate the protective effect of Hippophae salicifolia D.Don (H. salicifolia) berries extract against cerebral reperfusion injury induced neurobehavioral and neurochemical changes in a rat model of middle cerebral artery occlusion (MCAO). Methods: Rats were pretreated with alcoholic extract of H. salicifolia (250 and 500 mg/kg) for 14 d and focal cerebral ischemia was induced by MCAO. After 60 min of MCAO, reperfused for 24 h, a battery of behavioral tests were assessed the extent of neurological deficits. Infarct volume and brain edema were measured in 2,3,5-triphenyltetrazolium chloride stained brain sections. TNF-α, oxidative stress parameters like reduced glutathione, calcium, glutamate, malondialdehyde and apoptotic parameters like caspase-3, and caspase-9 were estimated in the brain homogenates. Results:Pretreatment with alcoholic extract of H. salicifolia at doses of 250 and 500 mg/kg significantly improved the neurobehavioral alterations and reduced the infarct volume, edema induced by ischemia reperfusion injury. H. salicifolia significantly prevented ischemia induced increase in malondialdehyde, glutamate, calcium, caspase-3, caspase-9 and TNF-αlevels as compared to ischemic animals. Conclusions: Our results indicate that H. salicifolia mitigated the ischemia reperfusion induced neuronal damage.

  3. Olive phenolics as c-Met inhibitors: (-)-Oleocanthal attenuates cell proliferation, invasiveness, and tumor growth in breast cancer models.

    Science.gov (United States)

    Akl, Mohamed R; Ayoub, Nehad M; Mohyeldin, Mohamed M; Busnena, Belnaser A; Foudah, Ahmed I; Liu, Yong-Yu; Sayed, Khalid A Ei

    2014-01-01

    Dysregulation of the Hepatocyte growth factor (HGF)/c-Met signaling axis upregulates diverse tumor cell functions, including cell proliferation, survival, scattering and motility, epithelial-to-mesenchymal transition (EMT), angiogenesis, invasion, and metastasis. (-)-Oleocanthal is a naturally occurring secoiridoid from extra-virgin olive oil, which showed antiproliferative and antimigratory activity against different cancer cell lines. The aim of this study was to characterize the intracellular mechanisms involved in mediating the anticancer effects of (-)-oleocanthal treatment and the potential involvement of c-Met receptor signaling components in breast cancer. Results showed that (-)-oleocanthal inhibits the growth of human breast cancer cell lines MDA-MB-231, MCF-7 and BT-474 while similar treatment doses were found to have no effect on normal human MCF10A cell growth. In addition, (-)-oleocanthal treatment caused a dose-dependent inhibition of HGF-induced cell migration, invasion and G1/S cell cycle progression in breast cancer cell lines. Moreover, (-)-oleocanthal treatment effects were found to be mediated via inhibition of HGF-induced c-Met activation and its downstream mitogenic signaling pathways. This growth inhibitory effect is associated with blockade of EMT and reduction in cellular motility. Further results from in vivo studies showed that (-)-oleocanthal treatment suppressed tumor cell growth in an orthotopic model of breast cancer in athymic nude mice. Collectively, the findings of this study suggest that (-)-oleocanthal is a promising dietary supplement lead with potential for therapeutic use to control malignancies with aberrant c-Met activity. PMID:24849787

  4. Ursolic acid attenuates oxidative stress in nigrostriatal tissue and improves neurobehavioral activity in MPTP-induced Parkinsonian mouse model.

    Science.gov (United States)

    Rai, Sachchida Nand; Yadav, Satyndra Kumar; Singh, Divakar; Singh, Surya Pratap

    2016-01-01

    Parkinson's disease (PD) is characterized by a slow and progressive degeneration of dopaminergic neurons in substantia nigra pars compacta (SNpc) region of brain. Oxidative stress and inflammation plays important role in the neurodegeneration and development of PD. Ursolic Acid (UA: 3β-hydroxy-urs-12-en-28-oic acid) is a natural pentacyclic triterpenoid found in various medicinal plants. Its anti-inflammatory and antioxidant activity is a well-established fact. In this paper, the neuroprotective efficiency of UA in MPTP induced PD mouse model has been explored. For this purpose, we divided 30 mice into 5 different groups; first was control, second was MPTP-treated, third, fourth and fifth were different doses of UA viz., 5 mg/kg, 25 mg/kg, and 50 mg/kg body weight (wt) respectively, along with MPTP. After 21 days of treatment, different behavioral parameters and biochemical assays were conducted. Tyrosine hydroxylase (TH) immunostaining of SN dopaminergic neurons as well as HPLC quantification of dopamine and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanilic acid (HVA) were also performed. Our results proved that, UA improves behavioral deficits, restored altered dopamine level and protect dopaminergic neurons in the MPTP intoxicated mouse. Among three different doses, 25 mg/kg body wt was the most effective dose for the PD. This work reveals the potential of UA as a promising drug candidate for PD treatment. PMID:26686287

  5. Seizure-like activity in a juvenile Angelman syndrome mouse model is attenuated by reducing Arc expression.

    Science.gov (United States)

    Mandel-Brehm, Caleigh; Salogiannis, John; Dhamne, Sameer C; Rotenberg, Alexander; Greenberg, Michael E

    2015-04-21

    Angelman syndrome (AS) is a neurodevelopmental disorder arising from loss-of-function mutations in the maternally inherited copy of the UBE3A gene, and is characterized by an absence of speech, excessive laughter, cognitive delay, motor deficits, and seizures. Despite the fact that the symptoms of AS occur in early childhood, behavioral characterization of AS mouse models has focused primarily on adult phenotypes. In this report we describe juvenile behaviors in AS mice that are strain-independent and clinically relevant. We find that young AS mice, compared with their wild-type littermates, produce an increased number of ultrasonic vocalizations. In addition, young AS mice have defects in motor coordination, as well as abnormal brain activity that results in an enhanced seizure-like response to an audiogenic challenge. The enhanced seizure-like activity, but not the increased ultrasonic vocalizations or motor deficits, is rescued in juvenile AS mice by genetically reducing the expression level of the activity-regulated cytoskeleton-associated protein, Arc. These findings suggest that therapeutic interventions that reduce the level of Arc expression have the potential to reverse the seizures associated with AS. In addition, the identification of aberrant behaviors in young AS mice may provide clues regarding the neural circuit defects that occur in AS and ultimately allow new approaches for treating this disorder. PMID:25848016

  6. Voluntary Running Attenuates Memory Loss, Decreases Neuropathological Changes and Induces Neurogenesis in a Mouse Model of Alzheimer's Disease.

    Science.gov (United States)

    Tapia-Rojas, Cheril; Aranguiz, Florencia; Varela-Nallar, Lorena; Inestrosa, Nibaldo C

    2016-01-01

    Alzheimer's disease (AD) is a neurodegenerative disorder characterized by loss of memory and cognitive abilities, and the appearance of amyloid plaques composed of the amyloid-β peptide (Aβ) and neurofibrillary tangles formed of tau protein. It has been suggested that exercise might ameliorate the disease; here, we evaluated the effect of voluntary running on several aspects of AD including amyloid deposition, tau phosphorylation, inflammatory reaction, neurogenesis and spatial memory in the double transgenic APPswe/PS1ΔE9 mouse model of AD. We report that voluntary wheel running for 10 weeks decreased Aβ burden, Thioflavin-S-positive plaques and Aβ oligomers in the hippocampus. In addition, runner APPswe/PS1ΔE9 mice showed fewer phosphorylated tau protein and decreased astrogliosis evidenced by lower staining of GFAP. Further, runner APPswe/PS1ΔE9 mice showed increased number of neurons in the hippocampus and exhibited increased cell proliferation and generation of cells positive for the immature neuronal protein doublecortin, indicating that running increased neurogenesis. Finally, runner APPswe/PS1ΔE9 mice showed improved spatial memory performance in the Morris water maze. Altogether, our findings indicate that in APPswe/PS1ΔE9 mice, voluntary running reduced all the neuropathological hallmarks of AD studied, reduced neuronal loss, increased hippocampal neurogenesis and reduced spatial memory loss. These findings support that voluntary exercise might have therapeutic value on AD.

  7. Addition of Sodium Pyruvate to Stored Red Blood Cells Attenuates Liver Injury in a Murine Transfusion Model

    Science.gov (United States)

    2016-01-01

    RBCs undergo numerous changes during storage and stored RBCs may induce adverse effects, ultimately resulting in organ injury in transfusion recipients. We tested the hypothesis that the addition of SP to stored RBCs would improve the quality of the stored RBCs and mitigate liver injury after transfusion in a murine model. RBCs were harvested from C57BL/6J mice and stored for 14 days in CPDA-1 containing either a solution of SP in saline or saline alone. Haemolysis, the 24-hour posttransfusion recovery, the oxygen-carrying capacity, and the SOD activity of stored RBCs were evaluated. The plasma biochemistry, hepatic MDA level, MPO activity, IL-6, TNF-α concentrations, and histopathology were measured two hours after the transfusion of stored RBCs. Compared with RBCs stored in CPDA-1 and saline, the addition of SP to stored RBCs restored their oxygen-carrying capacity and SOD activity, reduced the AST activity, BUN concentrations, and LDH activity in the plasma, and decreased the MDA level, MPO activity, and concentrations of IL-6 and TNF-α in the liver. These data indicate that the addition of SP to RBCs during storage has a beneficial effect on storage lesions in vitro and subsequently alleviates liver injury after the transfusion of stored RBCs in vivo.

  8. Aged Garlic Extract Attenuates Neuronal Injury in a Rat Model of Spinal Cord Ischemia/Reperfusion Injury.

    Science.gov (United States)

    Cemil, Berker; Gokce, Emre Cemal; Kahveci, Ramazan; Gokce, Aysun; Aksoy, Nurkan; Sargon, Mustafa Fevzi; Erdogan, Bulent; Kosem, Bahadir

    2016-06-01

    Garlic has been used as a food as well as a component of traditional medicine. Aged garlic extract (AGE) is claimed to promote human health through antioxidant/anti-inflammatory activities with neuroprotective effects. We evaluated the possible beneficial effect of AGE neurologically, pathologically, ultrastructurally, and biochemically in a spinal cord ischemia-reperfusion (I/R) model of rats. Twenty-four Sprague-Dawley rats were divided into three groups: sham (no I/R), I/R, and AGE (I/R+AGE); each group consisted of eight animals. Animals were evaluated neurologically with the Basso, Beattie, and Bresnahan (BBB) scoring system. The spinal cord tissue samples were harvested for pathological and ultrastructural examinations. Oxidative products (Malondialdehyde, nitric oxide), antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase), inflammatory cytokines (tissue tumor necrosis factor alpha, interleukin-1), and caspase-3 activity were analyzed. The AGE group had significantly higher BBB scores than the I/R group. Pathologically, AGE group revealed reduced degree of ischemia and spinal cord edema. Ultrastructural results also showed preservation of tissue structure in the AGE group. Oxidative product levels of the I/R group were significantly higher than both the other groups, and antioxidant enzyme levels of AGE group were significantly higher than the I/R group. There was also significant difference between the sham and AGE groups in terms of total antioxidant enzyme levels. Furthermore, AGE treatment significantly reduced the inflammatory cytokines and caspase-3 activity than the I/R group. This study demonstrates the considerable neuroprotective effect of AGE on the neurological, pathological, ultrastructural, and biochemical status of rats with I/R-induced spinal cord injury. PMID:27183321

  9. Olive phenolics as c-Met inhibitors: (--Oleocanthal attenuates cell proliferation, invasiveness, and tumor growth in breast cancer models.

    Directory of Open Access Journals (Sweden)

    Mohamed R Akl

    Full Text Available Dysregulation of the Hepatocyte growth factor (HGF/c-Met signaling axis upregulates diverse tumor cell functions, including cell proliferation, survival, scattering and motility, epithelial-to-mesenchymal transition (EMT, angiogenesis, invasion, and metastasis. (--Oleocanthal is a naturally occurring secoiridoid from extra-virgin olive oil, which showed antiproliferative and antimigratory activity against different cancer cell lines. The aim of this study was to characterize the intracellular mechanisms involved in mediating the anticancer effects of (--oleocanthal treatment and the potential involvement of c-Met receptor signaling components in breast cancer. Results showed that (--oleocanthal inhibits the growth of human breast cancer cell lines MDA-MB-231, MCF-7 and BT-474 while similar treatment doses were found to have no effect on normal human MCF10A cell growth. In addition, (--oleocanthal treatment caused a dose-dependent inhibition of HGF-induced cell migration, invasion and G1/S cell cycle progression in breast cancer cell lines. Moreover, (--oleocanthal treatment effects were found to be mediated via inhibition of HGF-induced c-Met activation and its downstream mitogenic signaling pathways. This growth inhibitory effect is associated with blockade of EMT and reduction in cellular motility. Further results from in vivo studies showed that (--oleocanthal treatment suppressed tumor cell growth in an orthotopic model of breast cancer in athymic nude mice. Collectively, the findings of this study suggest that (--oleocanthal is a promising dietary supplement lead with potential for therapeutic use to control malignancies with aberrant c-Met activity.

  10. A focused salivary gland infection with attenuated MCMV: an animal model with prevention of pathology associated with systemic MCMV infection.

    Science.gov (United States)

    Pilgrim, Mark J; Kasman, Laura; Grewal, Jasvir; Bruorton, Mary E; Werner, Phil; London, Lucille; London, Steven D

    2007-06-01

    While the salivary gland has been recognized as an important effector site of the common mucosal immune system, a useful model for studying anti-viral salivary gland immune responses in vivo and for exploring the role of the salivary gland within the common mucosal system has been lacking. Murine cytomegalovirus (MCMV) is a beta-herpesvirus that displays a strong tropism for the salivary gland and produces significant morbidity in susceptible mice when introduced by intraperitoneal (i.p.) inoculation. This study tested the hypothesis that MCMV morbidity and pathology could be reduced by injecting the virus directly the submandibular salivary gland (intraglandular (i.g.)), using either in vivo derived MCMV or the less virulent, tissue-culture-derived MCMV (tcMCMV). Peak salivary gland viral titers were completely unaffected by infection route (i.p vs. i.g.) after inoculation with either MCMV or tcMCMV. However, i.g. tcMCMV inoculation reduced viremia in all systemic tissues tested compared to i.p. inoculation. Furthermore, systemic organ pathology observed in the liver and spleen after i.p. inoculation with either MCMV or tcMCMV was completely eliminated by i.g. inoculation with tcMCMV. Cellular infiltrates in the salivary glands, after i.p. or i.g. inoculation were composed of both B and T cells, indicating the potential for a local immune response to occur in the salivary gland. These results demonstrate that a focused MCMV infection of the salivary gland without systemic organ pathology is possible using i.g. delivery of tcMCMV. PMID:17320076

  11. Minocycline Attenuates Depressive-Like Behaviour Induced by Rat Model of Testicular Torsion: Involvement of Nitric Oxide Pathway.

    Science.gov (United States)

    Saravi, Seyed Soheil Saeedi; Mousavi, Seyyedeh Elaheh; Saravi, Seyed Sobhan Saeedi; Dehpour, Ahmad Reza

    2016-04-01

    Testicular torsion/detorsion (T/D) can induce depression in pre- and post-pubertal patients. This study was conducted to investigate the psychological impact of testicular torsion and mechanism underlying its depressive-like behaviour, as well as antidepressant-like activity of minocycline and possible involvement of nitric oxide (NO)/cyclic GMP pathway in this paradigm in male rats undergoing testicular T/D. Unilateral T/D was performed in 36 male adult Wistar rats, and different doses of minocycline were injected alone or combined with N(ω) -nitro-l-arginine methyl ester (l-NAME), non-specific NO synthase (NOS) inhibitor; aminoguanidine (AG), specific inducible NOS inhibitor; l-arginine, an NO precursor; and selective PDE5I, sildenafil. After assessment of locomotor activity in open-field test, immobility times were recorded in the forced swimming test (FST). Moreover, 30 days after testicular T/D, testicular venous testosterone and serum nitrite concentrations were measured. A correlation was observed between either a decrease in plasma testosterone or an increase in serum nitrite concentrations with prolongation in immobility time in the testicular T/D-operated rats FST. Minocycline (160 mg/kg) exerted the highest significant antidepressant-like effect in the operated rats in the FST (p < 0.001). Furthermore, combination of subeffective doses of minocycline (80 mg/kg) and either l-NAME (10 mg/kg) or AG (50 mg/kg) demonstrated a significant robust antidepressant-like activity in T/D group (p < 0.01). Consequently, NO/cGMP pathway was involved in testicular T/D-induced depressive-like behaviour and antidepressant-like activity of minocycline in the animal model. Moreover, a contribution was observed between either decreased testosterone or elevated serum nitrite levels and depressive-like behaviour following testicular T/D. PMID:26381433

  12. KR-31543 reduces the production of proinflammatory molecules in human endothelial cells and monocytes and attenuates atherosclerosis in mouse model.

    Science.gov (United States)

    Choi, Jae-Hoon; Yoo, Ji-Young; Kim, Sun-Ok; Yoo, Sung-Eun; Oh, Goo Taeg

    2012-12-31

    KR-31543, (2S, 3R, 4S)-6-amino-4-[N-(4-chlorophenyl)- N-(2-methyl-2H-tetrazol-5-ylmethyl) amino]-3,4-dihydro- 2-dimethyoxymethyl-3-hydroxy-2-methyl-2H-1-benz opyran is a new neuroprotective agent for ischemiareperfusion damage. It has also been reported that KR-31543 has protective effects on lipid peroxidation and H₂O₂-induced reactive oxygen species production. In this study, we investigated the anti-inflammatory and anti-atherogenic properties of KR-31543. We observed that KR-31543 treatment reduced the production of MCP-1, IL-8, and VCAM-1 in HUVECs, and of MCP-1 and IL-6 in THP-1 human monocytes. We also examined the effect of KR-31543 on monocytes migration in vitro. KR-31543 treatment effectively reduced the migration of THP-1 human monocytes to the HUVEC monolayer in a dose-dependent manner. We next examined the effects of this compound on atherogenesis in LDL receptor deficient (Ldlr ⁻/⁻) mice. After 10 weeks of western diet, the formation of atherosclerotic lesion in aorta was reduced in the KR-31543-treated group compared to the control group. The accumulation of macrophages in lesion was also reduced in KR-31543 treated group. However, the plasma levels of total cholesterol, HDL, LDL, and triglyceride were not affected by KR-31543 treatment. Taken together, these results show that KR-31543 has anti-inflammatory properties on human monocytes and endothelial cells, and inhibits fatty streak lesion formation in mouse model of atherosclerosis, suggesting the potential of KR-31543 for the treatment for atherosclerosis.

  13. Cognitive training at a young age attenuates deficits in the zQ175 mouse model of HD

    Directory of Open Access Journals (Sweden)

    Paul C.P. Curtin

    2016-01-01

    Full Text Available Huntington’s Disease (HD is a progressive neurodegenerative disorder that causes motor, cognitive, and psychiatric symptoms. In these experiments, we tested if operant training at an early age affected adult cognitive deficits in the zQ175 KI Het (zQ175 mouse model of HD. In Experiment 1 we trained zQ175 mice in a fixed-ratio/progressive ratio (FR/PR task to assay learning and motivational deficits. We found pronounced deficits in response rates and task engagement in naïve adult zQ175 mice (32-33 weeks age, while deficits in zQ175 mice trained from 6-7 weeks age were either absent or less severe. When those mice were re-tested as adults, FR/PR performance deficits were absent or otherwise less severe than deficits observed in naïve adult zQ175 relative to wild type (WT mice. In Experiment 2, we used a Go/No-go operant task to assess the effects of early cognitive testing on response inhibition deficits in zQ175 mice. We found that zQ175 mice that began testing at 7-8 weeks did not exhibit deficits in Go/No-go testing, but when re-tested at 28-29 weeks age exhibited an initial impairment that diminished with training. These transient deficits were nonetheless mild relative to deficits observed among adult zQ175 mice without prior testing experience. In Experiment 3 we trained mice in a two-choice visual discrimination test to evaluate cognitive flexibility. As in prior experiments, we found performance deficits were mild or absent in mice that started training at 6-9 weeks of age, while deficits in naive mice exposed to training at 28-29 weeks were severe. Re-testing mice at 28-29 weeks age, were previously trained starting at 6-9 weeks, revealed that deficits in learning and cognitive flexibility were absent or reduced relative to effects observed in naive adults. In Experiment 4, we tested working memory deficits with a delayed non-match to position (DNMTP test. Mice with prior experience exhibited mild working memory deficits, with males

  14. Attenuation characteristics of ground motions in northern China

    Institute of Scientific and Technical Information of China (English)

    黄玉龙; 赵兴权; 罗奇峰

    2002-01-01

    Four recently developed attenuation models are calibrated by using a very limited amount of strong motion data recorded in China. The research shows that the attenuation characteristics of the earthquake shaking in northern China are similar to those in the western US. The supporting evidence includes Q factors, preliminary results of kappa values, stress drop,shear wave velocity profile in the shallow earth crust, areas enclosed by the isoseismals of Modified Mercalli Intensity V. From these comparisons of different attenuation models, it is recommended that the Crouse and McGuire spectral attenuation model could possibly be used for northern China.

  15. Cognitive Training at a Young Age Attenuates Deficits in the zQ175 Mouse Model of HD.

    Science.gov (United States)

    Curtin, Paul C P; Farrar, Andrew M; Oakeshott, Stephen; Sutphen, Jane; Berger, Jason; Mazzella, Matthew; Cox, Kimberly; He, Dansha; Alosio, William; Park, Larry C; Howland, David; Brunner, Daniela

    2015-01-01

    Huntington's Disease (HD) is a progressive neurodegenerative disorder that causes motor, cognitive, and psychiatric symptoms. In these experiments, we tested if operant training at an early age affected adult cognitive deficits in the zQ175 KI Het (zQ175) mouse model of HD. In Experiment 1 we trained zQ175 mice in a fixed-ratio/progressive ratio (FR/PR) task to assay learning and motivational deficits. We found pronounced deficits in response rates and task engagement in naïve adult zQ175 mice (32-33 weeks age), while deficits in zQ175 mice trained from 6-7 weeks age were either absent or less severe. When those mice were re-tested as adults, FR/PR performance deficits were absent or otherwise less severe than deficits observed in naïve adult zQ175 relative to wild type (WT) mice. In Experiment 2, we used a Go/No-go operant task to assess the effects of early cognitive testing on response inhibition deficits in zQ175 mice. We found that zQ175 mice that began testing at 7-8 weeks did not exhibit deficits in Go/No-go testing, but when re-tested at 28-29 weeks age exhibited an initial impairment that diminished with training. These transient deficits were nonetheless mild relative to deficits observed among adult zQ175 mice without prior testing experience. In Experiment 3 we trained mice in a two-choice visual discrimination test to evaluate cognitive flexibility. As in prior experiments, we found performance deficits were mild or absent in mice that started training at 6-9 weeks of age, while deficits in naive mice exposed to training at 28-29 weeks were severe. Re-testing mice at 28-29 weeks age, were previously trained starting at 6-9 weeks, revealed that deficits in learning and cognitive flexibility were absent or reduced relative to effects observed in naive adults. In Experiment 4, we tested working memory deficits with a delayed non-match to position (DNMTP) test. Mice with prior experience exhibited mild working memory deficits, with males zQ175 exhibiting

  16. Mechanisms of geometrical seismic attenuation

    Directory of Open Access Journals (Sweden)

    Igor B. Morozov

    2011-07-01

    Full Text Available In several recent reports, we have explained the frequency dependence of the apparent seismic quality-factor (Q observed in many studies according to the effects of geometrical attenuation, which was defined as the zero-frequency limit of the temporal attenuation coefficient. In particular, geometrical attenuation was found to be positive for most waves traveling within the lithosphere. Here, we present three theoretical models that illustrate the origin of this geometrical attenuation, and we investigate the causes of its preferential positive values. In addition, we discuss the physical basis and limitations of both the conventional and new attenuation models. For waves in media with slowly varying properties, geometrical attenuation is caused by variations in the wavefront curvature, which can be both positive (for defocusing and negative (for focusing. In media with velocity/density contrasts, incoherent reflectivity leads to geometrical-attenuation coefficients which are proportional to the mean squared reflectivity and are always positive. For «coherent» reflectivity, the geometrical attenuation is approximately zero, and the attenuation process can be described according to the concept of «scattering Q». However, the true meaning of this parameter is in describing the mean reflectivity within the medium, and not that of the traditional resonator quality factor known in mechanics. The general conclusion from these models is that non-zero and often positive levels of geometrical attenuation are common in realistic, heterogeneous media, both observationally and theoretically. When transformed into the conventional Q-factor form, this positive geometrical attenuation leads to Q values that quickly increase with frequency. These predictions show that the positive frequency-dependent Q observed in many datasets might represent artifacts of the transformations of the attenuation coefficients into Q.

  1. Clonorchis sinensis-derived total protein attenuates airway inflammation in murine asthma model by inducing regulatory T cells and modulating dendritic cell functions.

    Science.gov (United States)

    Jeong, Young-Il; Kim, Seung Hyun; Ju, Jung Won; Cho, Shin Hyeong; Lee, Won Ja; Park, Jin Wook; Park, Yeong-Min; Lee, Sang Eun

    2011-04-22

    Asthma is characterized by Th2-mediated inflammation, resulting in airway hyperresponsiveness (AHR) through airway remodeling. Recent epidemiological and experimental reports have suggested an inverse relationship between the development of allergy and helminth infections. Infection by Clonorchis sinensis, a liver fluke that resides in the bile duct of humans, is endemic predominantly in Asia including Korea and China. Using a murine model for asthma, we investigated the effects of C. sinensis-derived total protein (Cs-TP) on allergen-induced airway inflammation and the mechanism underlying the protective effects of Cs-TP administration on asthma. Treatment with Cs-TP attenuated OVA-induced airway inflammation and methacholine-induced AHR, as well as eosinophilia development, lymphocyte infiltration into the lung, and goblet cell metaplasia. This protective effect of Cs-TP is associated with markedly reduced OVA-specific IgE and Th1/Th2 cytokine production. Moreover, Cs-TP increased the number of CD4(+)CD25(+)Foxp3(+) regulatory T (Treg) cells as well as their suppressive activity. In fact, proliferation of OVA-restimulated splenocytes was suppressed significantly. Cs-TP also inhibited the expression of such co-stimulatory molecules as CD80, CD86, and CD40 in LPS- or OVA-stimulated dendritic cells (DCs), suggesting that Cs-TP could interfere with the capacity of airway DCs to prime naïve T cells. These data demonstrate the capacity of C. sinensis to ameliorate allergic asthma and broaden our understanding of the paradoxical relationship between the allergic immune response and helminth infection. PMID:21440530

  2. β-Caryophyllene, a phytocannabinoid attenuates oxidative stress, neuroinflammation, glial activation, and salvages dopaminergic neurons in a rat model of Parkinson disease.

    Science.gov (United States)

    Ojha, Shreesh; Javed, Hayate; Azimullah, Sheikh; Haque, M Emdadul

    2016-07-01

    Parkinson disease (PD) is a neurodegenerative disease characterized by progressive dopaminergic neurodegeneration in the substantia nigra pars compacta (SNc) area. The present study was undertaken to evaluate the neuroprotective effect of β-caryophyllene (BCP) against rotenone-induced oxidative stress and neuroinflammation in a rat model of PD. In the present study, BCP was administered once daily for 4 weeks at a dose of 50 mg/kg body weight prior to a rotenone (2.5 mg/kg body weight) challenge to mimic the progressive neurodegenerative nature of PD. Rotenone administration results in oxidative stress as evidenced by decreased activities of superoxide dismutase, catalase, and depletion of glutathione with a concomitant rise in lipid peroxidation product, malondialdehyde. Rotenone also significantly increased pro-inflammatory cytokines in the midbrain region and elevated the inflammatory mediators such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in the striatum. Further, immunohistochemical analysis revealed loss of dopaminergic neurons in the SNc area and enhanced expression of ionized calcium-binding adaptor molecule-1 (Iba-1) and glial fibrillary acidic protein (GFAP), indicators of microglia activation, and astrocyte hypertrophy, respectively, as an index of inflammation. However, treatment with BCP rescued dopaminergic neurons and decreased microglia and astrocyte activation evidenced by reduced Iba-1 and GFAP expression. BCP in addition to attenuation of pro-inflammatory cytokines and inflammatory mediators such as COX-2 and iNOS, also restored antioxidant enzymes and inhibited lipid peroxidation as well as glutathione depletion. The findings demonstrate that BCP provides neuroprotection against rotenone-induced PD and the neuroprotective effects can be ascribed to its potent antioxidant and anti-inflammatory activities. PMID:27316720

  3. Determination of the transient vibrations of a rigid rotor attenuated by a semiactive magnetorheological damping device by means of computational modelling

    Directory of Open Access Journals (Sweden)

    Zapoměl J.

    2013-12-01

    Full Text Available Unbalance is the principal source of increase of time varying forces transmitted between the rotor and its stationary part. Their magnitudes can be considerably reduced if the rotor is flexibly suspended and if the damping devices are added to the support elements. Their damping effect must be high for low rotor velocities and small for velocities approximately higher than the critical one to minimize the transmitted forces and the vibrations amplitude. This implies to achieve maximum efficiency of the damping elements, their damping effect has to be adaptable to the current operating conditions. Such technological solution is offered by application of a squeeze film magnetorheological damper. Its hybrid variant consisting of two damping units (one controllable in a serial arrangement is investigated in this paper. The damping takes place in two concentric lubricating films formed by normal and magnetorheological oils. The damper is equipped with an electric coil generating magnetic flux passing through the layer of the magnetorheological fluid. As resistance against its flow depends on magnetic induction, changing magnitude of the applied current enables to control the damping force. In the computational model, the rotor is considered to be absolutely rigid, unbalanced and the damping elements are represented by force couplings. The goal of the analysis is to study influence of the investigated magnetorheological damper on behaviour of a rigid rotor during different transient regimes. A special attention is focused on passing the rotor through the critical speed and on planning the dependence of the applied current on speed of the rotor rotation to achieve the optimum compromise between minimizing the transmitted forces and maximum attenuation of the rotor vibrations.

  4. Long-Term Treatment with Losartan Attenuates Seizure Activity and Neuronal Damage Without Affecting Behavioral Changes in a Model of Co-morbid Hypertension and Epilepsy.

    Science.gov (United States)

    Tchekalarova, Jana D; Ivanova, Natasha; Atanasova, Dimitrina; Pechlivanova, Daniela M; Lazarov, Nikolai; Kortenska, Lidia; Mitreva, Rumiana; Lozanov, Valentin; Stoynev, Alexander

    2016-08-01

    Over the last 10 years, accumulated experimental and clinical evidence has supported the idea that AT1 receptor subtype is involved in epilepsy. Recently, we have shown that the selective AT1 receptor antagonist losartan attenuates epileptogenesis and exerts neuroprotection in the CA1 area of the hippocampus in epileptic Wistar rats. This study aimed to verify the efficacy of long-term treatment with losartan (10 mg/kg) after kainate-induced status epilepticus (SE) on seizure activity, behavioral and biochemical changes, and neuronal damage in a model of co-morbid hypertension and epilepsy. Spontaneous seizures were video- and EEG-monitored in spontaneously hypertensive rats (SHRs) for a 16-week period after SE. The behavior was analyzed by open field, elevated plus maze, sugar preference test, and forced swim test. The levels of serotonin in the hippocampus and neuronal loss were estimated by HPLC and hematoxylin and eosin staining, respectively. The AT1 receptor antagonism delayed the onset of seizures and alleviated their frequency and duration during and after discontinuation of treatment. Losartan showed neuroprotection mostly in the CA3 area of the hippocampus and the septo-temporal hilus of the dentate gyrus in SHRs. However, the AT1 receptor antagonist did not exert a substantial influence on concomitant with epilepsy behavioral changes and decreased 5-HT levels in the hippocampus. Our results suggest that the antihypertensive therapy with an AT1 receptor blocker might be effective against seizure activity and neuronal damage in a co-morbid hypertension and epilepsy. PMID:26464042

  5. Vitamin A deficiency impairs adaptive B and T cell responses to a prototype monovalent attenuated human rotavirus vaccine and virulent human rotavirus challenge in a gnotobiotic piglet model.

    Directory of Open Access Journals (Sweden)

    Kuldeep S Chattha

    Full Text Available Rotaviruses (RV are a major cause of gastroenteritis in children. Widespread vitamin A deficiency is associated with reduced efficacy of vaccines and higher incidence of diarrheal infections in children in developing countries. We established a vitamin A deficient (VAD gnotobiotic piglet model that mimics subclinical vitamin A deficiency in children to study its effects on an oral human rotavirus (HRV vaccine and virulent HRV challenge. Piglets derived from VAD and vitamin A sufficient (VAS sows were orally vaccinated with attenuated HRV or mock, with/without supplemental vitamin A and challenged with virulent HRV. Unvaccinated VAD control piglets had significantly lower hepatic vitamin A, higher severity and duration of diarrhea and HRV fecal shedding post-challenge as compared to VAS control pigs. Reduced protection coincided with significantly higher innate (IFNα cytokine and CD8 T cell frequencies in the blood and intestinal tissues, higher pro-inflammatory (IL12 and 2-3 fold lower anti-inflammatory (IL10 cytokines, in VAD compared to VAS control pigs. Vaccinated VAD pigs had higher diarrhea severity scores compared to vaccinated VAS pigs, which coincided with lower serum IgA HRV antibody titers and significantly lower intestinal IgA antibody secreting cells post-challenge in the former groups suggesting lower anamnestic responses. A trend for higher serum HRV IgG antibodies was observed in VAD vs VAS vaccinated groups post-challenge. The vaccinated VAD (non-vitamin A supplemented pigs had significantly higher serum IL12 (PID2 and IFNγ (PID6 compared to vaccinated VAS groups suggesting higher Th1 responses in VAD conditions. Furthermore, regulatory T-cell responses were compromised in VAD pigs. Supplemental vitamin A in VAD pigs did not fully restore the dysregulated immune responses to AttHRV vaccine or moderate virulent HRV diarrhea. Our findings suggest that that VAD in children in developing countries may partially contribute to more

  6. Giardia duodenalis infection reduces granulocyte infiltration in an in vivo model of bacterial toxin-induced colitis and attenuates inflammation in human intestinal tissue.

    Directory of Open Access Journals (Sweden)

    James A Cotton

    Full Text Available Giardia duodenalis (syn. G. intestinalis, G. lamblia is a predominant cause of waterborne diarrheal disease that may lead to post-infectious functional gastrointestinal disorders. Although Giardia-infected individuals could carry as much as 106 trophozoites per centimetre of gut, their intestinal mucosa is devoid of overt signs of inflammation. Recent studies have shown that in endemic countries where bacterial infectious diseases are common, Giardia infections can protect against the development of diarrheal disease and fever. Conversely, separate observations have indicated Giardia infections may enhance the severity of diarrheal disease from a co-infecting pathogen. Polymorphonuclear leukocytes or neutrophils (PMNs are granulocytic, innate immune cells characteristic of acute intestinal inflammatory responses against bacterial pathogens that contribute to the development of diarrheal disease following recruitment into intestinal tissues. Giardia cathepsin B cysteine proteases have been shown to attenuate PMN chemotaxis towards IL-8/CXCL8, suggesting Giardia targets PMN accumulation. However, the ability of Giardia infections to attenuate PMN accumulation in vivo and how in turn this effect may alter the host inflammatory response in the intestine has yet to be demonstrated. Herein, we report that Giardia infection attenuates granulocyte tissue infiltration induced by intra-rectal instillation of Clostridium difficile toxin A and B in an isolate-dependent manner. This attenuation of granulocyte infiltration into colonic tissues paralled decreased expression of several cytokines associated with the recruitment of PMNs. Giardia trophozoite isolates that attenuated granulocyte infiltration in vivo also decreased protein expression of cytokines released from inflamed mucosal biopsy tissues collected from patients with active Crohn's disease, including several cytokines associated with PMN recruitment. These results demonstrate for the first time

  7. Implications of a composite source model and seismic wave attenuation for the observed simplicity of small earthquakes and reported duration of earthquake initial phase

    OpenAIRE

    Singh, S.K.; Ordaz, M.; Mikumo, T.; Pacheco, J.; Valdéz, C.; P Mandal

    1998-01-01

    An examination of P waves recorded on near-source, velocity seismograms generally shows that most small earthquakes (Mw < 2 to 3) are simple. On the other hand, larger earthquakes (Mw ≧ 4) are most often complex. The simplicity of the seismograms of Mw < 2 to 3 events may reflect the simplicity of the source (and, hence, may imply that smaller and larger earthquakes are not self-similar) or may be a consequence of attenuation of seismic waves. To test whether the attenuation is the cause, we ...

  8. Pre-treatment with bone marrow-derived mesenchymal stem cells inhibits systemic intravascular coagulation and attenuates organ dysfunction in lipopolysaccharide-induced disseminated intravascular coagulation rat model

    Institute of Scientific and Technical Information of China (English)

    WANG Biao; WU Shu-ming; WANG Tao; LIU Kai; ZHANG Gong; ZHANG Xi-quan; YU Jian-hua; LIU Chuan-zhen; FANG Chang-cun

    2012-01-01

    attenuate organ dysfunction and inhibit systemic intravascular coagulation effectively via the regulatory effect on immune ceils and proinflammatory cytokines in LPS-induced DIG rat model.

  9. Large-Scale Aquifer Test at the Bemidji, Minnesota, Oil-Spill Site: Implications for Modeling Multiphase Flow, Natural Attenuation, and LNAPL Remediation

    Science.gov (United States)

    Herkelrath, W. N.; Delin, G. N.

    2005-12-01

    A large-scale aquifer test was carried out at a crude oil spill site near Bemidji, Minnesota. The spill occurred in 1979 when a pipeline ruptured, spreading oil over a large area and creating three subsurface "pools" of high oil saturation near the water table. USGS scientists, in cooperation with researchers from several universities, have investigated the fate and transport of separate phase oil and hydrocarbons dissolved in ground water at this site since 1983. The primary goal of the aquifer test was to estimate parameters used in modeling processes such as subsurface flow of oil and water as well as natural attenuation of dissolved hydrocarbons in the plume. A secondary goal was to evaluate the effects of the oil on the parameters. Our aquifer test was carried out in July 2005 beneath the "north" oil pool, which occupies a 20x100 meter footprint. Prior to the test, the water table was about 6 meters below land surface, and the oil thickness in wells at the center of the pool was about 0.4 meters. A pumping well was installed near the center of the oil pool and screened 4-10 meters below the floating oil. During the test, water was pumped out at about 240 liters/min for 48 hours. Water levels were monitored in 21 wells that were screened below the water table and did not contain oil. Data loggers and pressure transducers were used to monitor 17 of these wells, and 4 wells were measured by hand using a tape. In 20 other wells that were screened at the water table and contained oil, depths to the oil-air and oil-water interfaces were monitored by hand using an oil-interface meter. Preliminary results indicate that oil thickness in wells within about 5 meters of the pumped well increased rapidly during the test to more than a meter. Oil also entered the top of the pumped well screen and filled the well bore to a thickness of about 3 meters. Preliminary analysis of water table drawdown vs. time data implies that the horizontal hydraulic conductivity is about 60 m

  10. Prophylactic combined supplementation of choline and docosahexaenoic acid attenuates vascular cognitive impairment and preserves hippocampal cell viability in rat model of chronic cerebral hypoperfusion ischemic brain injury

    Directory of Open Access Journals (Sweden)

    G. Sivakumar

    2015-06-01

    Conclusion: Prophylactic combined Cho-DHA suppl. may be envisaged as an effective preventive strategy to attenuate VCI and neuronal injury in high-risk individuals susceptible for a future event of an ischemic stroke. [Int J Basic Clin Pharmacol 2015; 4(3.000: 522-530

  11. Study of the safety, immunogenicity and efficacy of attenuated and killed Leishmania (Leishmania major vaccines in a rhesus monkey (Macaca mulatta model of the human disease

    Directory of Open Access Journals (Sweden)

    VF Amaral

    2002-10-01

    Full Text Available We have compared the efficacy of two Leishmania (Leishmania major vaccines, one genetically attenuated (DHFR-TS deficient organisms, the other inactivated [autoclaved promastigotes (ALM with bacillus Calmete-Guérin (BCG], in protecting rhesus macaques (Macaca mulatta against infection with virulent L. (L. major. Positive antigen-specific recall proliferative response was observed in vaccinees (79% in attenuated parasite-vaccinated monkeys, versus 75% in ALM-plus-BCG-vaccinated animals, although none of these animals exhibited either augmented in vitro gamma interferon (IFN-g production or positive delayed-type hypersensitivity (DTH response to the leishmanin skin test prior to the challenge. Following challenge, there were significant differences in blastogenic responses (p < 0.05 between attenuated-vaccinated monkeys and naïve controls. In both vaccinated groups very low levels of antibody were found before challenge, which increased after infective challenge. Protective immunity did not follow vaccination, in that monkeys exhibited skin lesion at the site of challenge in all the groups. The most striking result was the lack of pathogenicity of the attenuated parasite, which persisted in infected animals for up to three months, but were incapable of causing disease under the conditions employed. We concluded that both vaccine protocols used in this study are safe in primates, but require further improvement for vaccine application.

  12. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Naum Derzhi; Gary Mavko; Jack Dvorkin

    2003-12-01

    We have developed and tested technology for a new type of direct hydrocarbon detection. The method uses inelastic rock properties to greatly enhance the sensitivity of surface seismic methods to the presence of oil and gas saturation. These methods include use of energy absorption, dispersion, and attenuation (Q) along with traditional seismic attributes like velocity, impedance, and AVO. Our approach is to combine three elements: (1) a synthesis of the latest rock physics understanding of how rock inelasticity is related to rock type, pore fluid types, and pore microstructure, (2) synthetic seismic modeling that will help identify the relative contributions of scattering and intrinsic inelasticity to apparent Q attributes, and (3) robust algorithms that extract relative wave attenuation attributes from seismic data. This project provides: (1) Additional petrophysical insight from acquired data; (2) Increased understanding of rock and fluid properties; (3) New techniques to measure reservoir properties that are not currently available; and (4) Provide tools to more accurately describe the reservoir and predict oil location and volumes. These methodologies will improve the industry's ability to predict and quantify oil and gas saturation distribution, and to apply this information through geologic models to enhance reservoir simulation. We have applied for two separate patents relating to work that was completed as part of this project.

  13. Disruption of the sigS gene attenuates the local innate immune response to Staphylococcus aureus in a mouse mastitis model.

    Science.gov (United States)

    Peton, Vincent; Breyne, Koen; Rault, Lucie; Demeyere, Kristel; Berkova, Nadia; Meyer, Evelyne; Even, Sergine; Le Loir, Yves

    2016-04-15

    Staphylococcus aureus (S. aureus) is a major pathogen involved in ruminant mastitis and present worldwide. Clinical signs of S. aureus mastitis vary considerably and are largely dependent on strain-specific factors. A comparison of two S. aureus strains that reproducibly induced either severe (O11) or mild (O46) mastitis in ewes revealed that the transcriptional regulator sigS was mutated in O46 (Le Maréchal et al., 2011. PLoS One. 6 (11) e27354. doi:10.1371/journal.pone.0027354). In the present paper, we analysed the sigS sequence in 18 other S. aureus strains isolated from goat or ewe mastitis and found a 4-bp deletion similar to that of the O46 sigS gene in three strains associated with subclinical ewe mastitis. This sigS gene was disrupted in strain O11 (O11ΔsigS), so our aim was to investigate its involvement in the severity of infections in the context of mastitis. The wild type (wt) and mutant strains were then characterized in vitro to determine the involvement of sigS in the response S. aureus under various stress conditions, and assess its influence on the cytotoxicity of the pathogen, its invasive capacity and biofilm formation. The strains were compared in vivo in an experimental mouse mastitis model in which clinical signs and cytokine production were evaluated at 24h post-infection. While no significant differences in the effect on bacterial growth between O11 and O11ΔsigS were observed either in vitro or in vivo, a significantly weaker in vivo production of interleukin (IL)-1α, IL-1β, and Tumor Necrosis Factor (TNF)-α was measured in the mammary glands infected with the mutant strain, suggesting that infection with O11ΔsigS induced an attenuated local innate immune response. These results suggest an impact of sigS disruption on S. aureus pathogenesis in a ruminant mastitis context. This disruption is probably involved in, and may partly explain, the milder symptoms previously observed in S. aureus O46-induced mastitis in ewes.

  14. Disruption of the sigS gene attenuates the local innate immune response to Staphylococcus aureus in a mouse mastitis model.

    Science.gov (United States)

    Peton, Vincent; Breyne, Koen; Rault, Lucie; Demeyere, Kristel; Berkova, Nadia; Meyer, Evelyne; Even, Sergine; Le Loir, Yves

    2016-04-15

    Staphylococcus aureus (S. aureus) is a major pathogen involved in ruminant mastitis and present worldwide. Clinical signs of S. aureus mastitis vary considerably and are largely dependent on strain-specific factors. A comparison of two S. aureus strains that reproducibly induced either severe (O11) or mild (O46) mastitis in ewes revealed that the transcriptional regulator sigS was mutated in O46 (Le Maréchal et al., 2011. PLoS One. 6 (11) e27354. doi:10.1371/journal.pone.0027354). In the present paper, we analysed the sigS sequence in 18 other S. aureus strains isolated from goat or ewe mastitis and found a 4-bp deletion similar to that of the O46 sigS gene in three strains associated with subclinical ewe mastitis. This sigS gene was disrupted in strain O11 (O11ΔsigS), so our aim was to investigate its involvement in the severity of infections in the context of mastitis. The wild type (wt) and mutant strains were then characterized in vitro to determine the involvement of sigS in the response S. aureus under various stress conditions, and assess its influence on the cytotoxicity of the pathogen, its invasive capacity and biofilm formation. The strains were compared in vivo in an experimental mouse mastitis model in which clinical signs and cytokine production were evaluated at 24h post-infection. While no significant differences in the effect on bacterial growth between O11 and O11ΔsigS were observed either in vitro or in vivo, a significantly weaker in vivo production of interleukin (IL)-1α, IL-1β, and Tumor Necrosis Factor (TNF)-α was measured in the mammary glands infected with the mutant strain, suggesting that infection with O11ΔsigS induced an attenuated local innate immune response. These results suggest an impact of sigS disruption on S. aureus pathogenesis in a ruminant mastitis context. This disruption is probably involved in, and may partly explain, the milder symptoms previously observed in S. aureus O46-induced mastitis in ewes. PMID:27016756

  15. Control algorithms for dynamic attenuators

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, Scott S., E-mail: sshsieh@stanford.edu [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Pelc, Norbert J. [Department of Radiology, Stanford University, Stanford California 94305 and Department of Bioengineering, Stanford University, Stanford, California 94305 (United States)

    2014-06-15

    Purpose: The authors describe algorithms to control dynamic attenuators in CT and compare their performance using simulated scans. Dynamic attenuators are prepatient beam shaping filters that modulate the distribution of x-ray fluence incident on the patient on a view-by-view basis. These attenuators can reduce dose while improving key image quality metrics such as peak or mean variance. In each view, the attenuator presents several degrees of freedom which may be individually adjusted. The total number of degrees of freedom across all views is very large, making many optimization techniques impractical. The authors develop a theory for optimally controlling these attenuators. Special attention is paid to a theoretically perfect attenuator which controls the fluence for each ray individually, but the authors also investigate and compare three other, practical attenuator designs which have been previously proposed: the piecewise-linear attenuator, the translating attenuator, and the double wedge attenuator. Methods: The authors pose and solve the optimization problems of minimizing the mean and peak variance subject to a fixed dose limit. For a perfect attenuator and mean variance minimization, this problem can be solved in simple, closed form. For other attenuator designs, the problem can be decomposed into separate problems for each view to greatly reduce the computational complexity. Peak variance minimization can be approximately solved using iterated, weighted mean variance (WMV) minimization. Also, the authors develop heuristics for the perfect and piecewise-linear attenuators which do not requirea priori knowledge of the patient anatomy. The authors compare these control algorithms on different types of dynamic attenuators using simulated raw data from forward projected DICOM files of a thorax and an abdomen. Results: The translating and double wedge attenuators reduce dose by an average of 30% relative to current techniques (bowtie filter with tube current

  16. Microwave attenuation with composite of copper microwires

    Energy Technology Data Exchange (ETDEWEB)

    Gorriti, A.G.; Marin, P. [Instituto de Magnetismo Aplicado, (UCM-ADIF-CSIC) and Departamento de Fisica de Materiales (UCM). P.O. Box 155, Las Rozas, Madrid 28230 (Spain); Cortina, D. [Micromag S.L., Las Rozas, Madrid 28230 (Spain); Hernando, A., E-mail: antonio.hernando@adif.e [Instituto de Magnetismo Aplicado, (UCM-ADIF-CSIC) and Departamento de Fisica de Materiales (UCM). P.O. Box 155, Las Rozas, Madrid 28230 (Spain); Micromag S.L., Las Rozas, Madrid 28230 (Spain)

    2010-05-15

    It is shown that copper microwires composite media attenuates microwave reflection of metallic surfaces. We show how the distance to the metallic surface, as well as the length and volume fraction of microwires, determine the frequency of maximum absorption and the return loss level. Furthermore, we were able to fit the experimental results with a theoretical model based on Maxwell-Garnett mixing formula.

  17. Hadron attenuation at HERMES and JLab

    OpenAIRE

    Falter, T.; Cassing, W.; Gallmeister, K.; Mosel, U.

    2005-01-01

    We investigate the attenuation of hadrons in deep inelastic lepton-nucleus scattering in the kinematical regime of the HERMES and Jefferson Lab experiments. The calculation is carried out in the framework of a BUU transport model. Our results indicate a strong influence of (pre)hadronic final state interactions on the observed multiplicity ratios.

  18. Attenuation of neuroinflammation by dexmedetomidine is associated with activation of a cholinergic anti-inflammatory pathway in a rat tibial fracture model.

    Science.gov (United States)

    Zhu, Ya-Juan; Peng, Ke; Meng, Xiao-Wen; Ji, Fu-Hai

    2016-08-01

    Sustained neuroinflammation contributes to the pathogenesis of postoperative cognitive dysfunction. Dexmedetomidine, a selective α-2 adrenergic receptor agonist, exhibits a protective role in the brain. This study investigated whether dexmedetomidine pretreatment attenuates neuroinflammation induced by tibial fracture in rats, as well as the mechanism by which dexmedetomidine provides its neuroprotection. In our study, we observed that tibial fracture significantly increased the levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) and the expression of nuclear factor-kappa B (NF-κB) in the hippocampus. Overexpression of microglial (CD11b) and astrocytic (GFAP) responses to injury were observed in the hippocampus. Dexmedetomidine pretreatment significantly suppressed the inflammatory responses, as evidenced by lower TNF-α and IL-1β levels, significantly inhibited NF-κB activity, and alleviated overexpression of microglia and astrocytes in the hippocampus. However, pretreatment with dexmedetomidine failed to attenuate cytokine responses and activity of NF-κB, CD11b and GFAP after vagotomy or treatment with methyllycaconitine, an α-7 nicotinic acetylcholine receptor (α7nAChR) antagonist. These results suggest that pretreatment with dexmedetomidine may attenuate neuroinflammation caused by tibial fracture in rats through vagal-dependent and α7nAChR-dependent mechanisms. PMID:27163720

  19. Diazoxide Attenuates Postresuscitation Brain Injury in a Rat Model of Asphyxial Cardiac Arrest by Opening Mitochondrial ATP-Sensitive Potassium Channels.

    Science.gov (United States)

    Wu, Haidong; Wang, Peng; Li, Yi; Wu, Manhui; Lin, Jiali; Huang, Zitong

    2016-01-01

    Objective. We investigated whether and how diazoxide can attenuate brain injury after cardiopulmonary resuscitation (CPR) by selective opening of mitochondrial ATP-sensitive potassium (mitoKATP) channels. Methods. Adult male Sprague-Dawley rats with induced cerebral ischemia (n = 10 per group) received an intraperitoneal injection of 0.1% dimethyl sulfoxide (1 mL; vehicle group), diazoxide (10 mg/kg; DZ group), or diazoxide (10 mg/kg) plus 5-hydroxydecanoate (5 mg/kg; DZ + 5-HD group) 30 min after CPR. The control group (sham group, n = 5) underwent sham operation, without cardiac arrest. Mitochondrial respiratory control rate (RCR) was determined. Brain cell apoptosis was assessed using TUNEL staining. Expression of Bcl-2, Bax, and protein kinase C epsilon (PKCε) in the cerebral cortex was determined by Western blotting and immunohistochemistry. Results. The neurological deficit scores (NDS) in the vehicle group decreased significantly at 24 h and 48 h after CPR. Diazoxide significantly improved NDS and mitochondrial RCR after CPR at both time points; 5-HD cotreatment abolished these effects. Diazoxide decreased TUNEL-positive cells following CPR, upregulated Bcl-2 and PKCε, downregulated Bax, and increased the Bcl-2/Bax ratio; 5-HD cotreatment reversed these effects. Conclusions. Diazoxide attenuates postresuscitation brain injury, protects mitochondrial function, inhibits brain cell apoptosis, and activates the PKC pathway by opening mitoKATP channels. PMID:27648441

  20. Particle size characterization by ultrasonic attenuation spectra

    Institute of Scientific and Technical Information of China (English)

    Mingxu Su; Minghua Xue; Xiaoshu Cai; Zhitao Shang; Feng Xu

    2008-01-01

    This paper contributes to extracting information from signals of broadband ultrasonic attenuation spectrum for effective utilization in particle size characterization. The single particle scattering model and the coupled-phase model are formulated simultaneously, the relationship between particle size distribution and ultrasonic spectrum is established, and a convergence criterion for calculation is quantified. Demonsa'ation inversion by the optimum regularization factor method is carded out to yield typical numerical results for discussion. With the experimental set-up developed by the Institute of Particle and Two-Phase Flow Measurement (IPTFM) at the University of Shanghai for Science and Technology, sand sediment particle size is measured by attenuation spectrum and analyzed using the above inversion algorithm and theoretical models. To validate the proposed ultrasonic spectrum particle sizing method, results are compared with those obtained by microscopy.

  1. PID Gain Tuning for Disturbance Attenuation FRIT Method

    Science.gov (United States)

    Masuda, Shiro

    This review paper shows a PID gains tuning method from one-shot experimental data generated by test signal added at input signal in an off-line manner, so that the output signal could follow the prescribed reference model output. We call the method a “disturbance attenuation FRIT method” because the test signal added at input signal is a benchmark signal evaluating disturbance attenuation property. The experimental result for helicopter attitude control model is demonstrated to show the effectiveness of the disturbance attenuation FRIT method.

  2. Earth/Mars Landing Impact Attenuation Using Foam Project

    Data.gov (United States)

    National Aeronautics and Space Administration — On a previous ICA, a test correlated excel based software tool was developed using the innovative Stress?Energy method to better model impact attenuation using...

  3. Periportal low-attenuation: a CT sign of lymphatic obstruction

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hoon; Kim, Chong Soo; Yang, Doo Hyun; Lee, Sang Yong; Lee, Young Whan; Chung, Gyung Ho; Han, Young Min; Sohn, Myung Hee; Choi, Ki Chul [Chonbuk National University College of Medicine, Jeonju (Korea, Republic of)

    1995-07-15

    Periportal low attenuation, defined as a low attenuation rim around the portal vein and its branches which is seen on contrast material-enhanced CT scans, has been described in a variety of conditions. We tried to document that lymphatic obstruction is one of the major cause of periportal low attenuation. We retrospectively analyzed 57 cases of periportal low attenuation of abdominal CT scans and also reviewed the surgical records in 32 cases. Lymph node enlargement in the hepatoduodenal ligament which is a main lymphatic channel from the liver were analyzed the calculated the ratio of the transeverse diameter between the inferior vena cava and the aorta at the level of right adrenal gland. After complete surgical interruption of the lymphatic drainage from the liver in a dog, follow up CT scans were obtained and correlated with pathologic findings. Fifty patients (88%) had underlying disease which could cause impairment of lymphatic drainage. Periportal low attenuation was identified in several clinical conditions, including surgical lymph node dissection, lymphadenopathy in the hepatoduodenal ligament, blunt trauma. In animal model, CT scan showed prominent periportal low attenuation at 5 days after surgery. Histologic examination revealed numerous dilated lymphatic vessels and a marked lymphedema in the connective tissues surrounding the portal vein and its major branches. One of the major cause of periportal low attenuation was impaired lymphatic drainage and periportal low attenuation corresponding to the numerous dilated lymphatic vessels and a marked lymphedema in the connective tissues surrounding the portal vein and its major branches.

  4. 用椭圆衰减关系模型计算任意场点烈度及地震动参数的数值方法%AN ALGORITHM FOR ARBITRARY ENGINEERING SITE EARTHQUAKE INTENSITY OR MOTION PARAMETER USING ELLIPSOID ATTENUATION MODEL

    Institute of Scientific and Technical Information of China (English)

    石建梁; 闫庆民; 葛秋莹

    2011-01-01

    用椭圆衰减关系计算地震动或地震烈度,比较经典的做法是建立极坐标系,采用极坐标方程的方法.给出了一种在直角坐标系中即可求解的用椭圆衰减关系计算地震动或地震烈度的数值计算方法.另外,地震动椭圆衰减关系,应满足一定的模型要求,才能更客观地反映实际的地震动衰减物理过程.本算法的附加功能能够鉴别非标准的椭圆衰减关系.%The classic method using ellipsoid attenuation model to reckon earthquake intensity or motion parameter is establishing a polar coordinate system, then solving a polar equation.The author introduced a numerical computing method in rectangular coordinates for reckoning earthquake intensity or motion parameter using ellipsoid attenuation model.In addition, any correct ellipsoid attenuation model must fit some model conditions in order to express actual earthquake attenuation process.This algorithm can also distinguish the nonstandard ellipsoid attenuation model.

  5. Seismic attenuation in fractured media

    International Nuclear Information System (INIS)

    The prime objective of this paper is to quantitatively estimate seismic attenuation caused by fractures with different physical parameters. In seismic wave simulation, the fractured media are treated as the anisotropic media and fractures are represented by frequency-dependent elastic constants. Based on numerical experiments with three different parameters, namely viscosity, porosity and the Lamé parameters, this paper has the following observations. First, seismic attenuation is not affected by the viscosity within fractures, although it increases with the increase of porosity and decreases with the increase of the Lamé parameters within fractures. Among the latter two parameters, seismic attenuation is more sensitive to the Lamé parameters than to the porosity. Second, for the attenuation anisotropy, low frequencies have more anisotropic effect than high frequencies. For example, a 50 Hz wavefield has the strongest anisotropy effect if compared to 100 and 150 Hz wavefields. The attenuation anisotropy for low frequency (say 50 Hz) is more sensitive to the viscosity than the porosity and the Lamé parameters have the weakest effect among these three parameters. These observations suggest that low-frequency seismic attenuation, and especially the attenuation anisotropy in low frequency, would have great potential for fluid discrimination within fractured media. (paper)

  6. PDGF-C induces maturation of blood vessels in a model of glioblastoma and attenuates the response to anti-VEGF treatment.

    Directory of Open Access Journals (Sweden)

    Emmanuelle di Tomaso

    Full Text Available Recent clinical trials of VEGF inhibitors have shown promise in the treatment of recurrent glioblastomas (GBM. However, the survival benefit is usually short-lived as tumors escape anti-VEGF therapies. Here we tested the hypothesis that Platelet Derived Growth Factor-C (PDGF-C, an isoform of the PDGF family, affects GBM progression independent of VEGF pathway and hinders anti-VEGF therapy.We first showed that PDGF-C is present in human GBMs. Then, we overexpressed or downregulated PDGF-C in a human GBM cell line, U87MG, and grew them in cranial windows in nude mice to assess vessel structure and function using intravital microscopy. PDGF-C overexpressing tumors had smaller vessel diameters and lower vascular permeability compared to the parental or siRNA-transfected tumors. Furthermore, vessels in PDGF-C overexpressing tumors had more extensive coverage with NG2 positive perivascular cells and a thicker collagen IV basement membrane than the controls. Treatment with DC101, an anti-VEGFR-2 antibody, induced decreases in vessel density in the parental tumors, but had no effect on the PDGF-C overexpressing tumors.These results suggest that PDGF-C plays an important role in glioma vessel maturation and stabilization, and that it can attenuate the response to anti-VEGF therapy, potentially contributing to escape from vascular normalization.

  7. Curcumin Attenuates Beta-Amyloid-Induced Neuroinflammation via Activation of Peroxisome Proliferator-Activated Receptor-Gamma Function in a Rat Model of Alzheimer's Disease.

    Science.gov (United States)

    Liu, Zun-Jing; Li, Zhong-Hao; Liu, Lei; Tang, Wen-Xiong; Wang, Yu; Dong, Ming-Rui; Xiao, Cheng

    2016-01-01

    Neuroinflammation is known to have a pivotal role in the pathogenesis of Alzheimer's disease (AD), and curcumin has been reported to have therapeutical effects on AD because of its anti-inflammatory effects. Curcumin is not only a potent PPARγ agonist, but also has neuroprotective effects on cerebral ischemic injury. However, whether PPARγ activated by curcumin is responsible for the anti-neuroinflammation and neuroprotection on AD remains unclear, and needs to be further investigated. Here, using both APP/PS1 transgenic mice and beta-amyloid-induced neuroinflammation in mixed neuronal/glial cultures, we showed that curcumin significantly alleviated spatial memory deficits in APP/PS1 mice and promoted cholinergic neuronal function in vivo and in vitro. Curcumin also reduced the activation of microglia and astrocytes, as well as cytokine production and inhibited nuclear factor kappa B (NF-κB) signaling pathway, suggesting the beneficial effects of curcumin on AD are attributable to the suppression of neuroinflammation. Attenuation of these beneficial effects occurred when co-administrated with PPARγ antagonist GW9662 or silence of PPARγ gene expression, indicating that PPARγ might be involved in anti-inflammatory effects. Circular dichroism and co-immunoprecipitation analysis showed that curcumin directly bound to PPARγ and increased the transcriptional activity and protein levels of PPARγ. Taking together, these data suggested that PPARγ might be a potential target of curcumin, acting to alleviate neuroinflammation and improve neuronal function in AD. PMID:27594837

  8. High-Methionine Diet Attenuates Severity of Arthritis and Modulates IGF-I Related Gene Expressions in an Adjuvant Arthritis Rats Model

    Science.gov (United States)

    2016-01-01

    Rheumatoid arthritis, a synthesized form of adjuvant arthritis exhibited throughout many animal species, inhibits liver function and circulation of IGF-I and contributes to the degradation of skeletal muscle mass. One of the primary goals of the present study is determining whether a high-Methionine (high-Met) diet is capable of reducing the adverse effects of arthritis, namely, loss of body mass. Following adjuvant injection, forty arthritic rats were randomly assigned to either a control group with a basal diet or a high-Met group with the same basal diet + 0.5% Methionine. After 14 days all rats were terminated. The high-Met group exhibited an increase in body weight and food intake in comparison with the control group (P < 0.05). High-Met diet debilitated arthritis-induced surges in the gastrocnemius in both atrogin-1 and the MuRF1 expressions; however, it was observed to have little to no effect on atrogin-1 and MuRF1 gene expression in soleus. At the same time, high-Met diet rats experienced a rise in IGF-I, with lowering of IGFBP-3 gene expression in the gastrocnemius and the soleus. These data suggest that arthritis severity can be partly attenuated by high-Met diet. PMID:27738392

  9. Waves in fragmented geomaterials with impact attenuation

    Science.gov (United States)

    Dyskin, Arcady; Pasternak, Elena

    2016-04-01

    Attenuation of waves in geomaterials, such as seismic waves is usually attributed to energy dissipation due to the presence of viscous fluid and/or viscous cement between the constituents. In fragmented geomaterials such as blocky rock mass there is another possible source of energy dissipation - impacting between the fragments. This can be characterised by the coefficient of restitution, which is the ratio between the rotational velocities after and before the impact. In particular, this manifests itself in the process of mutual rotations of the fragments/blocks, whereby in the process of oscillation different ends of the contacting faces of the fragments are impacting. During the rotational oscillations the energy dissipation is concentrated in the neutral position that is the one in which the relative rotation between two fragments is zero. We show that in a simple system of two fragments this dissipation is equivalent, in a long run, to the presence of viscous damper between the fragments (the Voigt model of visco-elasticity). Generalisation of this concept to the material consisting of many fragments leads to a Voigt model of wave propagation where the attenuation coefficient is proportional to the logarithm of restitution coefficient. The waves in such a medium show slight dispersion caused by damping and strong dependence of the attenuation on the wave frequency.

  10. Rain Attenuation Prediction for Terrestrial Microwave Link in Bangladesh

    Directory of Open Access Journals (Sweden)

    HOSSAIN Sakir

    2014-05-01

    Full Text Available Rain attenuation is a major shortcoming of microwave transmission. As a subtropical country, Bangladesh is one of the highest rainy areas of the world. Thus, designing a terrestrial microwave link is a serious challenge to the engineers. In this paper, the annual rain rate and monthly variation of rate are predicted for different percentage of time of the year from the measured rainfall data. Using ITU rain model for terrestrial microwave communication, the rain attenuation is predicted for five major cities of Bangladesh, namely Dhaka, Chittagong, Rajshahi, Sylhet, and Khulna. It is found that rain attenuation is the most severe in Sylhet and least in Rajshahi. The attenuation is estimated for different frequency and polarization. A horizontally polarized signal encounters 15% more rain attenuation than that of vertically polarized signal. It is also found that attenuation in Rajshahi is about 20% lesser than that in Sylhet. Thus, the horizontally polarized transmission in Rajshahi experiences about 5% less attenuation than the vertically polarized transmission in Sylhet.

  11. MicroRNA-24 Attenuates Neointimal Hyperplasia in the Diabetic Rat Carotid Artery Injury Model by Inhibiting Wnt4 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Jian Yang

    2016-05-01

    Full Text Available The long-term stimulation of hyperglycemia greatly increases the incidence of vascular restenosis (RS after angioplasty. Neointimal hyperplasia after vascular injury is the pathological cause of RS, but its mechanism has not been elucidated. MicroRNA-24 (miR-24 has low expression in the injured carotid arteries of diabetic rats. However, the role of miR-24 in the vascular system is unknown. In this study, we explore whether over-expression of miR-24 could attenuate neointimal formation in streptozotocin (STZ-induced diabetic rats. Adenovirus (Ad-miR-24-GFP was used to deliver the miR-24 gene to injured carotid arteries in diabetic rats. The level of neointimal hyperplasia was examined by hematoxylin-eosin (HE staining. Vascular smooth muscle cell (VSMC proliferation in the neointima was evaluated by immunostaining for proliferating cell nuclear antigen (PCNA. The mRNA levels of miR-24, PCNA, wingless-type MMTV integration site family member 4 (Wnt4, disheveled-1 (Dvl-1, β-catenin and cell cycle-associated molecules (Cyclin D1, p21 were determined by Quantitative Real-Time PCR (qRT-PCR. PCNA, Wnt4, Dvl-1, β-catenin, Cyclin D1 and p21 protein levels were measured by Western blotting analysis. STZ administration decreased plasma insulin and increased fasting blood glucose in Sprague-Dawley (SD rats. The expression of miR-24 was decreased in the carotid artery after a balloon injury in diabetic rats, and adenoviral transfection (Ad-miR-24-GFP increased the expression of miR-24. Over-expression of miR-24 suppressed VSMC proliferation and neointimal hyperplasia in diabetic rats at 14 days. Furthermore, compared with Sham group, the mRNA and protein levels of PCNA, Wnt4, Dvl-1, β-catenin, and Cyclin D1 were strikingly up-regulated in the carotid arteries of diabetic rats after a balloon injury. Interestingly, up-regulation of miR-24 significantly reduced the mRNA and protein levels of these above molecules. In contrast, the change trend in p21 m

  12. Diallylsulfide attenuates excessive collagen production and apoptosis in a rat model of bleomycin induced pulmonary fibrosis through the involvement of protease activated receptor-2

    International Nuclear Information System (INIS)

    Pulmonary fibrosis (PF) can be a devastating lung disease. It is primarily caused by inflammation leading to severe damage of the alveolar epithelial cells. The pathophysiology of PF is not yet been clearly defined, but studying lung parenchymal injury by involving reactive oxygen species (ROS) through the activation of protease activated receptor-2 (PAR-2) may provide promising results. PAR-2 is a G-protein coupled receptor is known to play an important role in the development of PF. In this study, we investigated the inhibitory role of diallylsulfide (DAS) against ROS mediated activation of PAR-2 and collagen production accompanied by epithelial cell apoptosis. Bleomycin induced ROS levels may prompt to induce the expression of PAR-2 as well as extracellular matrix proteins (ECM), such as MMP 2 and 9, collagen specific proteins HSP-47, α-SMA, and cytokines IL-6, and IL-8RA. Importantly DAS treatment effectively decreased the expression of all these proteins. The inhibitory effect of DAS on profibrotic molecules is mediated by blocking the ROS level. To identify apoptotic signaling as a mediator of PF induction, we performed apoptotic protein expression, DNA fragmentation analysis and ultrastructural details of the lung tissue were performed. DAS treatment restored all these changes to near normalcy. In conclusion, treatment of PF bearing rats with DAS results in amelioration of the ROS production, PAR-2 activation, ECM production, collagen synthesis and alveolar epithelial cell apoptosis during bleomycin induction. We attained the first evidence that treatment of DAS decreases the ROS levels and may provide a potential therapeutic effect attenuating bleomycin induced PF. - Highlights: • DAS inhibits PAR-2 activity; bleomycin stimulates PAR-2 activity. • Increase in PAR-2 activity is correlated with pulmonary fibrosis • DAS reduces pro-inflammatory activity linked to facilitating pulmonary fibrosis. • DAS inhibits apoptosis of alveolar epithelial cells

  13. Inhalation of the BK(Ca-opener NS1619 attenuates right ventricular pressure and improves oxygenation in the rat monocrotaline model of pulmonary hypertension.

    Directory of Open Access Journals (Sweden)

    Marc Revermann

    Full Text Available BACKGROUND: Right heart failure is a fatal consequence of chronic pulmonary hypertension (PH. The development of PH is characterized by increased proliferation of vascular cells, in particular pulmonary artery smooth muscle cells (PASMCs and pulmonary artery endothelial cells. In the course of PH, an escalated right ventricular (RV afterload occurs, which leads to increased perioperative morbidity and mortality. BK(Ca channels are ubiquitously expressed in vascular smooth muscle cells and their opening induces cell membrane hyperpolarization followed by vasodilation. Moreover, BK activation induces anti-proliferative effects in a multitude of cell types. On this basis, we hypothesized that treatment with the nebulized BK channel opener NS1619 might be a therapy option for pulmonary hypertension and tested this in rats. METHODS: (1 Rats received monocrotaline injection for PH induction. Twenty-four days later, rats were anesthetized and NS1619 or the solvent was administered by inhalation. Systemic hemodynamic parameters, RV hemodynamic parameters, and blood gas analyses were measured before as well as 30 and 120 minutes after inhalation. (2 Rat PASMCs were stimulated with PDGF-BB in the presence and absence of NS1619. AKT, ERK1 and ERK2 activation were investigated by western blot analyses, and relative cell number was determined 48 hours after stimulation. RESULTS: Inhalation of a 12 µM and 100 µM NS1619 solution significantly reduced RV pressure without affecting systemic arterial pressure. Blood gas analyses demonstrated significantly reduced carbon dioxide and improved oxygenation in NS1619-treated animals pointing towards a considerable pulmonary shunt-reducing effect. In PASMC's, NS1619 (100 µM significantly attenuated PASMC proliferation by a pathway independent of AKT and ERK1/2 activation. CONCLUSION: NS1619 inhalation reduces RV pressure and improves oxygen supply and its application inhibits PASMC proliferation in vitro. Hence, BK

  14. Structural simulation of adenosine phosphate via plumbagin and zoledronic acid competitively targets JNK/Erk to synergistically attenuate osteoclastogenesis in a breast cancer model.

    Science.gov (United States)

    Qiao, H; Wang, T-y; Yu, Z-f; Han, X-g; Liu, X-q; Wang, Y-g; Fan, Q-m; Qin, A; Tang, T-t

    2016-01-01

    The treatment of breast cancer-induced osteolysis remains a challenge in clinical settings. Here, we explored the effect and mechanism of combined treatment with zoledronic acid (ZA) and plumbagin (PL), a widely investigated component derived from Plumbago zeylanica, against breast cancer-induced osteoclastogenesis. We found that the combined treatment with PL and ZA suppressed cell viability of precursor osteoclasts and synergistically inhibited MDA-MB-231-induced osteoclast formation (combination index=0.28) with the abrogation of recombinant mouse receptor activator of nuclear factor-κB ligand (RANKL)-induced activation of NF-κB/MAPK (nuclear factor-κB/mitogen-activated protein kinase) pathways. Molecular docking suggested a putative binding area within c-Jun N-terminal kinase/extracellular signal-regulated kinase (JNK/Erk) protease active sites through the structural mimicking of adenosine phosphate (ANP) by the spatial combination of PL with ZA. A homogeneous time-resolved fluorescence assay further illustrated the direct competitiveness of the dual drugs against ANP docking to phosphorylated JNK/Erk, contributing to the inhibited downstream expression of c-Jun/c-Fos/NFATc-1 (nuclear factor of activated T cells, cytoplasmic, calcineurin-dependent 1). Then, in vivo testing demonstrated that the combined administration of PL and ZA attenuated breast cancer growth in the bone microenvironment. Additionally, these molecules prevented the destruction of proximal tibia, with significant reduction of tartrate-resistant acid phosphatase (TRAcP)-positive osteoclast cells and potentiation of apoptotic cancer cells, to a greater extent when combined than when the drugs were applied independently. Altogether, the combination treatment with PL and ZA could significantly and synergistically suppress osteoclastogenesis and inhibit tumorigenesis both in vitro and in vivo by simulating the spatial structure of ANP to inhibit competitively phosphorylation of c-Jun N

  15. Diallylsulfide attenuates excessive collagen production and apoptosis in a rat model of bleomycin induced pulmonary fibrosis through the involvement of protease activated receptor-2

    Energy Technology Data Exchange (ETDEWEB)

    Kalayarasan, Srinivasan, E-mail: kalaivasanbio@gmail.com; Sriram, Narayanan; Soumyakrishnan, Syamala; Sudhandiran, Ganapasam, E-mail: sudhandiran@yahoo.com

    2013-09-01

    Pulmonary fibrosis (PF) can be a devastating lung disease. It is primarily caused by inflammation leading to severe damage of the alveolar epithelial cells. The pathophysiology of PF is not yet been clearly defined, but studying lung parenchymal injury by involving reactive oxygen species (ROS) through the activation of protease activated receptor-2 (PAR-2) may provide promising results. PAR-2 is a G-protein coupled receptor is known to play an important role in the development of PF. In this study, we investigated the inhibitory role of diallylsulfide (DAS) against ROS mediated activation of PAR-2 and collagen production accompanied by epithelial cell apoptosis. Bleomycin induced ROS levels may prompt to induce the expression of PAR-2 as well as extracellular matrix proteins (ECM), such as MMP 2 and 9, collagen specific proteins HSP-47, α-SMA, and cytokines IL-6, and IL-8RA. Importantly DAS treatment effectively decreased the expression of all these proteins. The inhibitory effect of DAS on profibrotic molecules is mediated by blocking the ROS level. To identify apoptotic signaling as a mediator of PF induction, we performed apoptotic protein expression, DNA fragmentation analysis and ultrastructural details of the lung tissue were performed. DAS treatment restored all these changes to near normalcy. In conclusion, treatment of PF bearing rats with DAS results in amelioration of the ROS production, PAR-2 activation, ECM production, collagen synthesis and alveolar epithelial cell apoptosis during bleomycin induction. We attained the first evidence that treatment of DAS decreases the ROS levels and may provide a potential therapeutic effect attenuating bleomycin induced PF. - Highlights: • DAS inhibits PAR-2 activity; bleomycin stimulates PAR-2 activity. • Increase in PAR-2 activity is correlated with pulmonary fibrosis • DAS reduces pro-inflammatory activity linked to facilitating pulmonary fibrosis. • DAS inhibits apoptosis of alveolar epithelial cells.

  16. H2 Treatment Attenuated Pain Behavior and Cytokine Release Through the HO-1/CO Pathway in a Rat Model of Neuropathic Pain.

    Science.gov (United States)

    Chen, Yajun; Chen, Hongguang; Xie, Keliang; Liu, Lingling; Li, Yuan; Yu, Yonghao; Wang, Guolin

    2015-10-01

    Neuropathic pain (NP) is characterized by persistent pain, tactile allodynia, or hyperalgesia. Peripheral nerve injury contributes to rapid progress of inflammatory response and simultaneously generates neuropathic pain. Hydrogen (H2) has anti-inflammation, anti-apoptosis, and anti-oxidative stress effects. Therefore, we hypothesized that H2 treatment could alleviate allodynic and hyperalgesic behaviors and the release of inflammatory factors in rats with neuropathic pain. Peripheral neuropathic pain was established by chronic constriction injury of sciatic nerve in rats. H2 was given twice through intraperitoneal injection at a daily dose of 10 mL/kg during days 1-7 after the operation. Hyperalgesia and allodynia were tested, pro-inflammatory factors of dorsal root ganglia (DRG) and the spinal cord were measured by enzyme-linked immunosorbent assay (ELISA) during days 1-14 after the operation, and heme oxygenase (HO)-1 messenger RNA (mRNA) and protein expression and activities were measured at day 14 after sciatic nerve injury in rats. After Sn (IV) protoporphyrin IX dihydrochloride (SnPP)-IX, hemin, and carbon monoxide-releasing molecule (CORM)-2 had been given for chronic constriction injury (CCI) in rats, the above indicators were assessed. We found that H2 clearly inhibited hyperalgesia and allodynia in neuropathic pain and also attenuated the pro-inflammatory cytokines TNF-α, IL-1β, and high-mobility group box (HMGB) 1. H2 improved HO-1 mRNA and protein expression and activities in the process of pain. SnPP-IX reversed the inhibitory effect of H2 on hyperalgesia and allodynia and on pro-inflammatory cytokines in DRG and the spinal cord. The antinociceptive and anti-inflammatory effects of H2 were involved in the activation of HO-1/CO signaling during neuropathic pain in rats. PMID:25820467

  17. Estimation of compressional seismic wave attenuation of carbonate rocks in Abu Dhabi, United Arab Emirates

    Science.gov (United States)

    Bouchaala, Fateh; Ali, Mohammed Y.; Farid, Asam

    2014-07-01

    The subsurface geology of Abu Dhabi in the United Arab Emirates is primarily composed of carbonate rocks. Such media are known to be highly heterogeneous. Very few studies have attempted to estimate attenuation in carbonate rocks. In Abu Dhabi no attenuation profile has been published. This study provides the first seismic wave attenuation profiles in Abu Dhabi using dense array of VSP data. We estimated three attenuation profiles: the apparent, the scattering, and the intrinsic attenuations. The apparent attenuation profile was computed using amplitude decay and spectral-ratio methods. The scattering attenuation profile was estimated using a generalized reflection-transmission matrix forward model. It is usually estimated from the sonic log, but to be more consistent with the apparent attenuation, we succeeded in this paper to estimate it from the VSP data. We subtracted the scattering attenuation from the apparent attenuation to deduce the intrinsic attenuation. The results of the study indicate that the scattering attenuation is significant compared to the published studies that are mainly based on clastic rocks. The high scattering attenuation can reach up to 0.02. It can be explained by the strong heterogeneity of the carbonate rocks. This study demonstrates that the Simsima and Rus Formations have considerable scattering and intrinsic attenuations. These formations are considered aquifers in Abu Dhabi; we therefore interpreted this high intrinsic attenuation zones to be due to the heterogeneity and to the fluids contained in these formations. The Umm-Er-Radhuma Formation is a more homogenous formation with limited aquifer potential. Hence, scattering and intrinsic attenuations of the Umm-Er-Radhuma Formation are low.

  18. An analysis of seismic attenuation in random porous media

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The attenuation of seismic wave in rocks has been one of the interesting research topics, but till now no poroelasticity models can thoroughly explain the strong attenuation of wave in rocks. In this paper, a random porous medium model is designed to study the law of wave propagation in complex rocks based on the theory of Biot poroelasticity and the general theory of stochastic process. This model sets the density of grain, porosity, permeability and modulus of frame as random parameters in space, and only one fluid infiltrates in rocks for the sake of better simulation effect in line with real rocks in earth strata. Numerical simulations are implemented. Two different inverse quality factors of fast P-wave are obtained by different methods to assess attenuation through records of virtual detectors in wave field (One is amplitude decay method in time domain and the other is spectral ratio method in frequency domain). Comparing the attenuation results of random porous medium with those of homogeneous porous medium, we conclude that the attenuation of seismic wave of homogeneous porous medium is far weaker than that of random porous medium. In random porous media, the higher heterogeneous level is, the stronger the attenuation becomes, and when heterogeneity σ = 0.15 in simulation, the attenuation result is consistent with that by actual observation. Since the central frequency (50 Hz) of source in numerical simulation is in earthquake band, the numerical results prove that heterogeneous porous structure is one of the important factors causing strong attenuation in real stratum at intermediate and low frequency.

  19. Nuclear Attenuation of Charged Mesons in Deep Inelastic Scattering

    CERN Document Server

    Akopov, N Z; Grigoryan, L A

    2002-01-01

    We propose extended version of stationary string model to describe the nuclear attenuation. This model takes into account flavour content of particles and allows to include into consideration all hadrons created from string. The predictions of the model are compared with experimental results obtained by HERMES collaboration (DESY) on different nuclei (N and Kr).

  20. Estimation of Water Vapour Attenuation And Rain Attenuation

    Directory of Open Access Journals (Sweden)

    K.Kalyana Srinivas

    2015-04-01

    Full Text Available Attenuation due to and water vapour and rain can severely degrade the radio wave propagation at centimeter or millimeter wavelengths. It restricts the path length of radio communication systems and limits the use of higher frequencies for line-of-sight microwave links and satellite communications. The attenuation will pose a greater problem to communication as the frequency of occurrence of heavy rain increases.In a tropical region, like Malaysia, where excessive rainfall is a common phenomenon throughout the year, the knowledge of the rain attenuation at the frequency of operation is extremely required for the design of a reliable terrestrial and earth space communication link at a particular location.

  1. P2X7 Receptor Antagonism Attenuates the Intermittent Hypoxia-induced Spatial Deficits in a Murine Model of Sleep Apnea Via Inhibiting Neuroinflammation and Oxidative Stress

    Institute of Scientific and Technical Information of China (English)

    Yan Deng; Xue-Ling Guo; Xiao Yuan; Jin Shang; Die Zhu; Hui-Guo Liu

    2015-01-01

    Background:The mechanism of the neural injury caused by chronic intermittent hypoxia (CIH) that characterizes obstructive sleep apnea syndrome (OSAS) is not clearly known.The purpose of this study was to investigate whether P2X7 receptor (P2X7R) is responsible for the CIH-induced neural injury and the possible pathway it involves.Methods:Eight-week-old male C57BL/6 mice were used.For each exposure time point,eight mice divided in room air (RA) and IH group were assigned to the study of P2X7R expression.Whereas in the 21 days-Brilliant Blue G (BBG,a selective P2X7R antagonist) study,48 mice were randomly divided into CIH group,BBG-treated CIH group,RA group and BBG-treated RA group.The hippocampus P2X7R expression was determined by Western blotting and real-time polymerase chain reaction (PCR).The spatial learning was analyzed by Morris water maze.The nuclear factor kappa B (NFκB) and NADPH oxidase 2 (NOX2) expressions were analyzed by Westem blotting.The expressions of tumor necrosis factor α,interleukin 1 β (IL-β),IL-18,and IL-6 were measured by real-time PCR.The malondialdehyde and superoxide dismutase levels were detected by colorimetric method.Cell damage was evaluated by Hematoxylin and Eosin staining and Terminal Transferase dUTP Nick-end Labeling method.Results:The P2X7R mRNA was elevated and sustained after 3-day IH exposure and the P2X7R protein was elevated and sustained after 7-day IH exposure.In the BBG study,the CIH mice showed severer neuronal cell damage and poorer performance in the behavior test.The increased NFκB and NOX2 expressions along with the inflammation injury and oxidative stress were also observed in the CIH group.BBG alleviated CIH-induced neural injury and consequent functional deficits.Conclusions:The P2X7R antagonism attenuates the CIH-induced neuroinflammation,oxidative stress,and spatial deficits,demonstrating that the P2X7R is an important therapeutic target in the cognition deficits accompanied OSAS.

  2. Lithium attenuates cannabinoid-induced dependence in the animal model: involvement of phosphorylated ERK1/2 and GSK-3β signaling pathways.

    Directory of Open Access Journals (Sweden)

    Hamid Reza Rahimi

    2014-09-01

    Full Text Available Cannabis is one of the most banned drugs in the world. Cannabinoid-induced dependence or withdrawal signs are indicated by the result of complex molecular mechanisms including upstream protein kinases (PKs, such as an extracellular signal regulated kinase1/2 (ERK1/2 and downstream glycogen synthase kinase-3β (GSK-3β, which lead to neuronal plasticity. In this study, we examined the protective effect of lithium (Li as a potent ERK1/2 and GSK-3β modulator to prevent the development of dependence on cannabinoids. For this purpose, rats were treated twice daily with increasing doses of WIN 55,212-2 (WIN, 2-8 mg/kg, intraperitoneally (i.p., for five consecutive days. AM251 (AM, 2 mg/kg, a cannabinoid antagonist, was injected i.p to induce manifestations of abstinence in rat dependency on WIN, and the subsequent withdrawal signs were recorded. To evaluate the preventive effect of Li, the rats were pre-treated with Li (10 mg/kg, i.p. twice daily, 30 minutes before every injection of WIN. SL327, as an ERK1/2 inhibitor, was also injected (SL, 50 mg/kg, i.p. 30 minutes before the last doses of WIN in separate groups. The p-ERK1/2, total ERK1/2, p-GSK-3β and total GSK-3β expressions were determined with Western blot method after 60 minutes, prior to the Li, WIN or AM injections. Li and SL pre-treatment attenuated the global withdrawal signs in regarding their modulation effect on the up-regulation of p-ERK1/2 cascade enhanced by AM injection. Furthermore, the p-GSK-3β expression was up-regulated with SL and Li pre-treatment against AM injection, without alteration on the total contents of ERK1/2 and GSK-3β level. Therefore, p-ERK1/2 and p-GSK-3β pathways are involved in the cannabinoid-induced dependence. However, no crosstalk was indicated between these two pathways. In conclusion, Li neuroprotectionwith regard to cannabinoid abstinence may occur through the regulation of the p-ERK1/2 cascade inconsequent of p-GSK-3β signaling pathways in rats.

  3. Galectin-3 Ablation Enhances Liver Steatosis, but Attenuates Inflammation and IL-33-Dependent Fibrosis in Obesogenic Mouse Model of Nonalcoholic Steatohepatitis.

    Science.gov (United States)

    Jeftic, Ilija; Jovicic, Nemanja; Pantic, Jelena; Arsenijevic, Nebojsa; Lukic, Miodrag L; Pejnovic, Nada

    2015-01-01

    The importance of Galectin-3 (Gal-3) in obesity-associated liver pathology is incompletely defined. To dissect the role of Gal-3 in fibrotic nonalcoholic steatohepatitis (NASH), Gal-3-deficient (LGALS3(-/-)) and wild-type (LGALS3(+/+)) C57Bl/6 mice were placed on an obesogenic high fat diet (HFD, 60% kcal fat) or standard chow diet for 12 and 24 wks. Compared to WT mice, HFD-fed LGALS3(-/-) mice developed, in addition to increased visceral adiposity and diabetes, marked liver steatosis, which was accompanied with higher expression of hepatic PPAR-γ, Cd36, Abca-1 and FAS. However, as opposed to LGALS3(-/-) mice, hepatocellular damage, inflammation and fibrosis were more extensive in WT mice which had an elevated number of mature myeloid dendritic cells, proinflammatory CD11b(+)Ly6C(hi) monocytes/macrophages in liver, peripheral blood and bone marrow, and increased hepatic CCL2, F4/80, CD11c, TLR4, CD14, NLRP3 inflammasome, IL-1β and NADPH-oxidase enzymes mRNA expression. Thus, obesity-driven greater steatosis was uncoupled with attenuated fibrotic NASH in Gal-3-deficient mice. HFD-fed WT mice had a higher number of hepatocytes that strongly expressed IL-33 and hepatic CD11b(+)IL-13(+) cells, increased levels of IL-33 and IL-13 and up-regulated IL-33, ST2 and IL-13 mRNA in liver compared with LGALS3(-/-) mice. IL-33 failed to induce ST2 upregulation and IL-13 production by LGALS3(-/-) peritoneal macrophages in vitro. Administration of IL-33 in vivo enhanced liver fibrosis in HFD-fed mice in both genotypes, albeit to a significantly lower extent in LGALS3(-/-) mice, which was associated with less numerous hepatic IL-13-expressing CD11b(+) cells. The present study provides evidence of a novel role for Gal-3 in regulating IL-33-dependent liver fibrosis. PMID:26018806

  4. Natural Biological Attenuation of Benzene in Groundwater

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Benzene has been found in subsurface unsaturated soil and groundwater beneath a petro-chemical plant. Although the groundwater contained several mg/L of benzene in the area immediately beneath the source, benzene was not detected in monitoring wells approximately 800m down stream. All kinds of physical processes such as adsorption and advection/dispersion are considered to account for the observed attenuation. The results indicated that the attenuation was primarily due to natural biological processes occurring within the aquifer. The evidence for the natural bioremediation of benzene from the groundwater included: (1) analysis of groundwater chemistry, (2) laboratory studies demonstrating benzene biodegradation in aquifer samples, and (3) computer simulations examining benzene transport. Laboratory experiments indicated that for conditions similar to those in the plume, the aerobic degradation of benzene by the naturally occurring microorganisms in the polluted groundwater samples was quite rapid with a half-life time of from 5 to 15 days. In situ analyses indicated the level of dissolved oxygen in the groundwater was over 2mg/L. Thus, oxygen should not limit the biodegradation. In fact, the benzene was also shown to degrade under anaerobic conditions. The results from the modeling simulations indicate that biodegradation is the dominant process influencing attenuation of the benzene.

  5. Validation of mathematical models to describe fluid dynamics of a cold riser by gamma ray attenuation; Validacao de modelos matematicos para descrever a fluidodinamica de um riser utilizando atenuacao gama

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Ana Cristina Bezerra Azedo de

    2004-12-15

    The fluid dynamic behavior of a riser in a cold type FCC model was investigated by means of catalyst concentration distribution measured with gamma attenuation and simulated with a mathematical model. In the riser of the cold model, MEF, 0,032 m in diameter, 2,30 m in length the fluidized bed, whose components are air and FCC catalyst, circulates. The MEF is operated by automatic control and instruments for measuring fluid dynamic variables. An axial catalyst concentration distribution was measured using an Am-241 gamma source and a NaI detector coupled to a multichannel provided with a software for data acquisition and evaluation. The MEF was adapted for a fluid dynamic model validation which describes the flow in the riser, for example, by introducing an injector for controlling the solid flow in circulation. Mathematical models were selected from literature, analyzed and tested to simulate the fluid dynamic of the riser. A methodology for validating fluid dynamic models was studied and implemented. The stages of the work were developed according to the validation methodology, such as data planning experiments, study of the equations which describe the fluidodynamic, computational solvers application and comparison with experimental data. Operational sequences were carried out keeping the MEF conditions for measuring catalyst concentration and simultaneously measuring the fluid dynamic variables, velocity of the components and pressure drop in the riser. Following this, simulated and experimental values were compared and statistical data treatment done, aiming at the required precision to validate the fluid dynamic model. The comparison tests between experimental and simulated data were carried out under validation criteria. The fluid dynamic behavior of the riser was analyzed and the results and the agreement with literature were discussed. The adopt model was validated under the MEF operational conditions, for a 3 to 6 m/s gas velocity in the riser and a slip

  6. Lg Attenuation of the Western United States

    Science.gov (United States)

    Gallegos, A. C.; Ranasinghe, N. R.; Ni, J.; Sandvol, E. A.

    2014-12-01

    Lg waveforms recorded by EarthScope's Transportable Array (TA) are used to estimate Lg Q in the Western United States (WUS). Attenuation is calculated based on Lg spectral amplitudes filtered at a narrow band from 0.5 to 1.5 Hz with a central frequency of 1 Hz. The two-station and reverse two-station techniques were used to calculate Qo values. 398 events occurring from 2005 to 2009 and ranging from magnitude 3 to magnitude 6 were used in this study. The geometric spreading term can be determined by using a three-dimensional linear fit of the amplitude ratios versus epicentral distances to two stations. The slope of this line provides the geometric spreading term we use to calculate Lg Qo values of WUS. The results show high Q regions (low attenuation) corresponding to the Colorado Plateau (CP), the Rocky Mountains (RM), the Columbia Plateau (COP), and the Sierra Nevada Mountains (SNM). Regions of low Q (high attenuation) are seen along the Snake River Plain (SRP), the Rio Grande Rift (RGR), the Cascade Mountains (CM), and in east and west of the Basin and Range (BR) where tectonic activity is more active than the central part of the BR. A positive correlation between high heat flow, recent tectonic activity and Q was observed. Areas with low heat flow, thin sediment cover, and no recent tectonic activity were observed to have consistently high Q. These new models use two-station and reversed two-station methods and provide a comparison with previous studies and better constrain regions with high attenuation. This increase in detail can improve high frequency ground motion predictions of future large earthquakes for more accurate hazard assessment and improve overall understanding of the structure and assemblage of the WUS.

  7. The attenuation and the attenuators: strategies and tactics

    Directory of Open Access Journals (Sweden)

    Antonio Briz

    2013-12-01

    Full Text Available This work is inscribed in a research project (ES.POR.ATENUAÇÃO that seeks to analyze and explain the attenuator activity in different regional varieties of Spanish and Portuguese, in order to perform, subsequently, different contrastive intralinguistic and interlinguistic studies. In this article, we explain some of the theoretical and methodological principles on which are based the qualitative and quantitative analysis. And especially, we will refer to the concept of attenuation (Briz 1995, 2002, 2003, 2005, 2007a, 2012.

  8. Multi-transmitting formula for attenuating waves

    Institute of Scientific and Technical Information of China (English)

    陈少林; 廖振鹏

    2003-01-01

    The MTF is extended to case of attenuating incident wave by introducing an attenuation coefficient. The reflection coefficients of this modified MTF and MTF areevaluated and compared when an attenuating wave impinges on the boundary, and the results demonstrate that MTF can be used to absorb slightly attenuating wavesand the modified MTF is more capable of absorbing heavily attenuating waves than MTF. The accuracy of modified MTF is also tested by numerical examples of fluid saturated porous media.

  9. Attenuation of laser generated ultrasound in steel at high temperatures; comparison of theory and experimental measurements.

    Science.gov (United States)

    Kube, Christopher M

    2016-08-01

    This article reexamines some recently published laser ultrasound measurements of the longitudinal attenuation coefficient obtained during annealing of two steel samples (DP600 and S550). Theoretical attenuation models based on perturbation theory are compared to these experimental measurements. It is observed that the Rayleigh attenuation formulas provide the correct qualitative agreement, but overestimate the experimental values. The more general theoretical attenuation model considered here demonstrates strong quantitative agreement, which highlights the applicability of the model during real-time metal processing. PMID:27235777

  10. Sound attenuation in magnetorheological fluids

    Science.gov (United States)

    Rodríguez-López, J.; Elvira, L.; Resa, P.; Montero de Espinosa, F.

    2013-02-01

    In this work, the attenuation of ultrasonic elastic waves propagating through magnetorheological (MR) fluids is analysed as a function of the particle volume fraction and the magnetic field intensity. Non-commercial MR fluids made with iron ferromagnetic particles and two different solvents (an olive oil based solution and an Araldite-epoxy) were used. Particle volume fractions of up to 0.25 were analysed. It is shown that the attenuation of sound depends strongly on the solvent used and the volume fraction. The influence of a magnetic field up to 212 mT was studied and it was found that the sound attenuation increases with the magnetic intensity until saturation is reached. A hysteretic effect is evident once the magnetic field is removed.

  11. Josephson tunnel junction microwave attenuator

    DEFF Research Database (Denmark)

    Koshelets, V. P.; Shitov, S. V.; Shchukin, A. V.;

    1993-01-01

    A new element for superconducting electronic circuitry-a variable attenuator-has been proposed, designed, and successfully tested. The principle of operation is based on the change in the microwave impedance of a superconductor-insulator-superconductor (SIS) Josephson tunnel junction when dc biased...... at different points in the current-voltage characteristic. Both numerical calculations based on the Tien-Gordon theory and 70-GHz microwave experiments have confirmed the wide dynamic range (more than 15-dB attenuation for one stage) and the low insertion loss in the ''open'' state. The performance of a fully...... integrated submillimeter receiver circuit which comprises a flux-flow oscillator (FFO) as local oscillator, a superconducting variable attenuator, and a microwave SIS detector with tuned-out capacitance is also reported....

  12. X-Ray Attenuation Cell

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D.; Toor, A.

    2000-03-03

    To minimize the pulse-to-pulse variation, the LCLS FEL must operate at saturation, i.e. 10 orders of magnitude brighter spectral brilliance than 3rd-generation light sources. At this intensity, ultra-high vacuums and windowless transport are required. Many of the experiments, however, will need to be conducted at a much lower intensity thereby requiring a reliable means to reduce the x-ray intensity by many orders of magnitude without increasing the pulse-to-pulse variation. In this report we consider a possible solution for controlled attenuation of the LCLS x-ray radiation. We suggest using for this purpose a windowless gas-filled cell with the differential pumping. Although this scheme is easily realizable in principle, it has to be demonstrated that the attenuator can be made short enough to be practical and that the gas loads delivered to the vacuum line of sight (LOS) are acceptable. We are not going to present a final, optimized design. Instead, we will provide a preliminary analysis showing that the whole concept is robust and is worth further study. The spatial structure of the LCLS x-ray pulse at the location of the attenuator is shown in Fig. 1. The central high-intensity component, due to the FEL, has a FWHM of {approx}100 {micro}m. A second component, due to the undulator's broad band spontaneous radiation is seen as a much lower intensity ''halo'' with a FWHM of 1 mm. We discuss two versions of the attenuation cell. The first is directed towards a controlled attenuation of the FEL up to the 4 orders of magnitude in the intensity, with the spontaneous radiation halo being eliminated by collimators. In the second version, the spontaneous radiation is not sacrificed but the FEL component (as well as the first harmonic of the spontaneous radiation) gets attenuated by a more modest factor up to 100. We will make all the estimates assuming that the gas used in the attenuator is Xenon and that the energy of the FEL is 8.25 keV. At

  13. An anti-interleukin-2 receptor drug attenuates thelper 1 lymphocytes-mediated inflammation in an acute model of endotoxin-induced uveitis

    OpenAIRE

    Mérida, S.; Sancho Tello, M.; Navea, A; Almansa, Inmaculada; Muriach Saurí, María; Bosch Morell, F.

    2014-01-01

    The aim of the present study was to evaluate the anti-inflammatory efficacy of Daclizumab, an anti-interleukin-2 receptor drug, in an experimental uveitis model upon a subcutaneous injection of lipopolysaccharide into Lewis rats, a valuable model for ocular acute inflammatory processes. The integrity of the blood-aqueous barrier was assessed 24 h after endotoxin-induced uveitis by evaluating two parameters: cell count and protein concentration in aqueous humors. The histopathology...

  14. Two-layer earth model corrections to theMLTWA estimates of intrinsic- and scattering-attenuation obtained in a uniform half-space

    OpenAIRE

    Del Pezzo, E.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia; Bianco, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione OV, Napoli, Italia

    2010-01-01

    Following the numerical scheme of Yoshimoto we synthesized seismogram envelopes in the multiple scattering framework.We supposed the earth model constituted by a inhomogeneous crust overlying a transparent mantle. In this model velocity is assumed depth-dependent through a continuous function of the depth, v = v(h); Moho discontinuity is approximated by a sharp increase of the velocity around the crust–mantle boundary; inhomogeneity in the crust is parametrized through a depth-...

  15. Diffusion-weighted MR imaging of metastatic abdominal and pelvic tumours is sensitive to early changes induced by a VEGF inhibitor using alternative diffusion attenuation models

    International Nuclear Information System (INIS)

    To assess the utility of diffusion weighted imaging for monitoring early treatment effects associated with a VEGF inhibitor. Twenty-nine patients with metastatic abdominal and pelvic tumours were recruited and imaged with DW-MRI: twice at baseline, and after 7 and 28 days of treatment with cediranib. Tumour measures were derived using mono-exponential, bi-exponential and stretched-exponential models, and parameter repeatability and treatment effects seen after 7 and 28 days were assessed. Correlations with volume changes and DCE-MRI metrics were also assessed. Diffusion coefficient repeatabilities from all models were < 6 %; f and D* (bi-exponential) were 22 % and 44 %; α (stretched-exponential) was 4.2 %. Significant increases in the diffusion coefficients from all models were observed at day 28 but not day 7. Significant decreases in D* and f.D* were observed at day 7 and in f at day 28; significant increases in α were observed at both time-points. Weak correlations between DW-MRI changes and volume changes and DCE-MRI changes were observed. DW-MRI is sensitive to early and late treatment changes caused by a VEGF inhibitor using non-mono-exponential models. Evidence of over-fitting using the bi-exponential model suggests that the stretched-exponential model is best suited to monitor such changes. (orig.)

  16. Diffusion-weighted MR imaging of metastatic abdominal and pelvic tumours is sensitive to early changes induced by a VEGF inhibitor using alternative diffusion attenuation models

    Energy Technology Data Exchange (ETDEWEB)

    Orton, Matthew R. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Institute of Cancer Research, Sutton, Surrey (United Kingdom); Messiou, Christina; DeSouza, Nandita [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Royal Marsden NHS Foundation Trust, Department of Radiology, Sutton, Surrey (United Kingdom); Collins, David; Leach, Martin O. [Institute of Cancer Research and Royal Marsden NHS Foundation Trust, CRUK and EPSRC Cancer Imaging Centre, Sutton, Surrey (United Kingdom); Morgan, Veronica A. [Royal Marsden NHS Foundation Trust, Department of Radiology, Sutton, Surrey (United Kingdom); Tessier, Jean; Young, Helen [Early Clinical Development, AstraZeneca, Macclesfield (United Kingdom)

    2016-05-15

    To assess the utility of diffusion weighted imaging for monitoring early treatment effects associated with a VEGF inhibitor. Twenty-nine patients with metastatic abdominal and pelvic tumours were recruited and imaged with DW-MRI: twice at baseline, and after 7 and 28 days of treatment with cediranib. Tumour measures were derived using mono-exponential, bi-exponential and stretched-exponential models, and parameter repeatability and treatment effects seen after 7 and 28 days were assessed. Correlations with volume changes and DCE-MRI metrics were also assessed. Diffusion coefficient repeatabilities from all models were < 6 %; f and D* (bi-exponential) were 22 % and 44 %; α (stretched-exponential) was 4.2 %. Significant increases in the diffusion coefficients from all models were observed at day 28 but not day 7. Significant decreases in D* and f.D* were observed at day 7 and in f at day 28; significant increases in α were observed at both time-points. Weak correlations between DW-MRI changes and volume changes and DCE-MRI changes were observed. DW-MRI is sensitive to early and late treatment changes caused by a VEGF inhibitor using non-mono-exponential models. Evidence of over-fitting using the bi-exponential model suggests that the stretched-exponential model is best suited to monitor such changes. (orig.)

  17. Targeting Dyrk1A with AAVshRNA Attenuates Motor Alterations in TgDyrk1A, a Mouse Model of Down Syndrome

    OpenAIRE

    Ortiz-Abalia, Jon; Sahún, Ignasi; Altafaj, Xavier; Andreu, Núria; Estivill, Xavier; Dierssen, Mara; Fillat, Cristina

    2008-01-01

    Genetic-dissection studies carried out with Down syndrome (DS) murine models point to the critical contribution of Dyrk1A overexpression to the motor abnormalities and cognitive deficits displayed in DS individuals. In the present study we have used a murine model overexpressing Dyrk1A (TgDyrk1A mice) to evaluate whether functional CNS defects could be corrected with an inhibitory RNA against Dyrk1A, delivered by bilateral intrastriatal injections of adeno-associated virus type 2 (AAVshDyrk1A...

  18. Restoration of Dopamine Release Deficits during Object Recognition Memory Acquisition Attenuates Cognitive Impairment in a Triple Transgenic Mice Model of Alzheimer's Disease

    Science.gov (United States)

    Guzman-Ramos, Kioko; Moreno-Castilla, Perla; Castro-Cruz, Monica; McGaugh, James L.; Martinez-Coria, Hilda; LaFerla, Frank M.; Bermudez-Rattoni, Federico

    2012-01-01

    Previous findings indicate that the acquisition and consolidation of recognition memory involves dopaminergic activity. Although dopamine deregulation has been observed in Alzheimer's disease (AD) patients, the dysfunction of this neurotransmitter has not been investigated in animal models of AD. The aim of this study was to assess, by in vivo…

  19. Compact plasmonic variable optical attenuator

    DEFF Research Database (Denmark)

    Leosson, Kristjan; Rosenzveig, Tiberiu; Hermannsson, Pétur Gordon;

    2008-01-01

    We demonstrate plasmonic nanowire-based thermo-optic variable optical attenuators operating in the 1525-1625 nm wavelength range. The devices have a footprint as low as 1 mm, extinction ratio exceeding 40 dB, driving voltage below 3 V, and full modulation bandwidth of 1 kHz. The polarization...

  20. Simultaneous inversion for velocity and attenuation by waveform tomography

    Science.gov (United States)

    Gao, Fengxia; Wang, Yanghua

    2016-08-01

    Seismic waveform tomography can invert for the velocity and attenuation (Q- 1) variations simultaneously. For this simultaneous inversion, we propose two strategies for waveform tomography. First, we analyze the contributions of the real part and the imaginary part of the gradients, associated with the velocity and attenuation parameters respectively, and determine that the combination of the real part of the gradient subvector for the velocity parameter and the imaginary part of the gradient subvector for the attenuation parameter would produce an optimal inversion result. Second, we attempt to balance the sensitivities of the objective function to the velocity and the attenuation parameters. Considering the magnitude differences between these two-type parameters in the simultaneous inversion, we apply preliminarily a normalization to both the velocity model and the attenuation model. However, for balancing their sensitivities, we further adjust the corresponding model updates using a tuning factor. We determine this tuning parameter adaptively, based on the sensitivities of these two parameters, at each iteration. Numerical tests demonstrate the feasibility and reliability of these two strategies in full waveform inversion.

  1. Chronic escitalopram treatment attenuated the accelerated rapid eye movement sleep transitions after selective rapid eye movement sleep deprivation: a model-based analysis using Markov chains

    OpenAIRE

    Kostyalik, Diána; Vas, Szilvia; Kátai, Zita; Kitka, Tamás; Gyertyán, István; Bagdy, Gyorgy; Tóthfalusi, László

    2014-01-01

    Background Shortened rapid eye movement (REM) sleep latency and increased REM sleep amount are presumed biological markers of depression. These sleep alterations are also observable in several animal models of depression as well as during the rebound sleep after selective REM sleep deprivation (RD). Furthermore, REM sleep fragmentation is typically associated with stress procedures and anxiety. The selective serotonin reuptake inhibitor (SSRI) antidepressants reduce REM sleep time and increas...

  2. Neuroprotective effect of novel cognitive enhancer noopept on AD-related cellular model involves the attenuation of apoptosis and tau hyperphosphorylation

    OpenAIRE

    Ostrovskaya, Rita U; Vakhitova, Yulia V; Kuzmina, Uliyana Sh; Salimgareeva, Milyausha Kh; Zainullina, Liana F; Gudasheva, Tatiana A; Vakhitov, Vener A; Seredenin, Sergey B

    2014-01-01

    Background Noopept (N-phenyl-acetyl-L-prolylglycine ethyl ester) was constructed as a dipeptide analog of the standard cognition enhancer, piracetam. Our previous experiments have demonstrated the cognition restoring effect of noopept in several animal models of Alzheimer disease (AD). Noopept was also shown to prevent ionic disbalance, excitotoxicity, free radicals and pro-inflammatory cytokines accumulation, and neurotrophine deficit typical for different kinds of brain damages, including A...

  3. Determination of rain attenuation from electromagnetic scattering by spherical raindrops: Theory and experiment

    Science.gov (United States)

    Odedina, M. O.; Afullo, T. J.

    2010-02-01

    The forward scattering amplitudes for the spherical raindrops are determined for all raindrop sizes at different frequencies by using the Mie scattering theory. The real parts of the extinction cross sections are used to generate power law models at different frequencies. These are integrated over different established raindrop-size distribution models to formulate rain attenuation models. Using the developed rain attenuation models with 5 year rain rate statistics at R0.01 determined in previous work, the specific rain attenuation is computed. The experimental results obtained from the horizontally polarized signal level measurements recorded in Durban for different rain attenuation bounds are compared with the theoretical results. Finally, the best theoretical model is used to estimate the seasonal cumulative distribution of rain attenuation for Durban, South Africa.

  4. Genetic ablation of Bcl-x attenuates invasiveness without affecting apoptosis or tumor growth in a mouse model of pancreatic neuroendocrine cancer.

    Directory of Open Access Journals (Sweden)

    Jeffrey H Hager

    Full Text Available Tumor cell death is modulated by an intrinsic cell death pathway controlled by the pro- and anti-apoptotic members of the Bcl-2 family. Up-regulation of anti-apoptotic Bcl-2 family members has been shown to suppress cell death in pre-clinical models of human cancer and is implicated in human tumor progression. Previous gain-of-function studies in the RIP1-Tag2 model of pancreatic islet carcinogenesis, involving uniform or focal/temporal over-expression of Bcl-x(L, demonstrated accelerated tumor formation and growth. To specifically assess the role of endogenous Bcl-x in regulating apoptosis and tumor progression in this model, we engineered a pancreatic beta-cell-specific knockout of both alleles of Bcl-x using the Cre-LoxP system of homologous recombination. Surprisingly, there was no appreciable effect on tumor cell apoptosis rates or on tumor growth in the Bcl-x knockout mice. Other anti-apoptotic Bcl-2 family members were expressed but not substantively altered at the mRNA level in the Bcl-x-null tumors, suggestive of redundancy without compensatory transcriptional up-regulation. Interestingly, the incidence of invasive carcinomas was reduced, and tumor cells lacking Bcl-x were impaired in invasion in a two-chamber trans-well assay under conditions mimicking hypoxia. Thus, while the function of Bcl-x in suppressing apoptosis and thereby promoting tumor growth is evidently redundant, genetic ablation implicates Bcl-x in selectively facilitating invasion, consistent with a recent report documenting a pro-invasive capability of Bcl-x(L upon exogenous over-expression.

  5. Δ122p53, a mouse model of Δ133p53α, enhances the tumor-suppressor activities of an attenuated p53 mutant

    OpenAIRE

    Slatter, T L; Hung, N. Van; Bowie, S; Campbell, H.; Rubio, C; Speidel, D; Wilson, M.; Baird, M.; Royds, J. A.; Braithwaite, A W

    2015-01-01

    Growing evidence suggests the Δ133p53α isoform may function as an oncogene. It is overexpressed in many tumors, stimulates pathways involved in tumor progression, and inhibits some activities of wild-type p53, including transactivation and apoptosis. We hypothesized that Δ133p53α would have an even more profound effect on p53 variants with weaker tumor-suppressor capability. We tested this using a mouse model heterozygous for a Δ133p53α-like isoform (Δ122p53) and a p53 mutant with weak tumor-...

  6. Edaravone attenuates hippocampal damage in an infant mouse model of pneumococcal meningitis by reducing HMGB1 and iNOS expression via the Nrf2/HO-1 pathway

    Science.gov (United States)

    Li, Zheng; Ma, Qian-qian; Yan, Yan; Xu, Feng-dan; Zhang, Xiao-ying; Zhou, Wei-qin; Feng, Zhi-chun

    2016-01-01

    Aim: Edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) is a free radical scavenger that has shown potent antioxidant, anti-inflammatory and neuroprotective effects in variety of disease models. In this study, we investigated whether edaravone produced neuroprotective actions in an infant mouse model of pneumococcal meningitis. Methods: C57BL/6 mice were infected on postnatal d 11 by intracisternal injection of a certain inoculum of Streptococcus pneumoniae. The mice received intracisternal injection of 10 μL of saline containing edaravone (3 mg/kg) once a day for 7 d. The severity of pneumococcal meningitis was assessed with a clinical score. In mice with severe meningitis, the survival rate from the time of infection to d 8 after infection was analyzed using Kaplan-Meier curves. In mice with mild meningitis, the CSF inflammation and cytokine levels in the hippocampus were analyzed d 7 after infection, and the clinical neurological deficit score was evaluated using a neurological scoring system d 14 after infection. The nuclear factor (erythroid-derived 2)-like 2 knockout (Nrf2 KO) mice and heme oxygenase-1 knockout (HO-1 KO) mice were used to confirm the involvement of Nrf2/HO-1 pathway in the neuroprotective actions of edaravone. Results: In mice with severe meningitis, edaravone treatment significantly increased the survival rate (76.4%) compared with the meningitis model group (32.2%). In mice with mild meningitis, edaravone treatment significantly decreased the number of leukocytes and TNF- levels in CSF, as well as the neuronal apoptosis and protein levels of HMGB1 and iNOS in the hippocampus, but did not affect the high levels of IL-10 and IL-6 in the hippocampus. Moreover, edaravone treatment significantly improved the neurological function of mice with mild meningitis. In Nrf2 KO or HO-1 KO mice with the meningitis, edaravone treatment was no longer effective in improving the survival rate of the mice with severe meningitis (20.2% and 53.6%, respectively

  7. Ultrasonic attenuation in the mixed state of Nb-26 at.% Hf

    International Nuclear Information System (INIS)

    The ultrasonic attenuation in the mixed state of Nb-26 at.% Hf was measured at T = 4.14 K, using shear waves with frequencies 5 to 140 MHz. The data cannot be interpreted in terms of the theories of Houghton and Maki and of Cerdeira and Houghton. On the other hand, the measured attenuation is in good agreement with the phenomenological model of Shapira and Neuringer for the attenuation in the mixed state. (author)

  8. Attenuation of Shocks through Porous Media

    Science.gov (United States)

    Lind, Charles A.; Cybyk, Bohdan Z.; Boris, Jay P.

    1998-11-01

    Structures designed to mitigate the effects of blast and shock waves are important for both accidental and controlled explosions. The net effect of these mitigating structures is to reduce the strength of the transmitted shock thereby reducing the dynamic pressure loading on nearby objects. In the present study, the attenuation of planar blast and shock waves by passage through structured media is numerically studied with the FAST3D model. The FAST3D model is a state-of-the-art, portable, three-dimensional computational fluid dynamics model based on Flux-Corrected Transport and uses the Virtual Cell Embedding algorithm for simulating complex geometries. The effects of media placement, spacing, orientation, and area blockage are parametrically studied to enhance the understanding of the complex processes involved and to determine ways to minimize the adverse effects of these blast waves.

  9. Suppression of MAPK and NF-κ B pathways by schisandrin B contributes to attenuation of DSS-induced mice model of inflammatory bowel disease.

    Science.gov (United States)

    Liu, Weidong; Liu, Yang; Wang, Zhi; Yu, Ting; Lu, Qin; Chen, Hong

    2015-09-01

    Schisandrin B (Sch B), the most abundant dibenzocyclooctadiene lignan isolated from the traditional Chinese medicinal herb Schisandra chinensis (Turcz.) Baill, possesses various biological activities, such as hepatic protection, anti-tumor, anti-inflammatory and anti-cardiovascular properties. However, the effect of Sch B on inflammatory bowel disease (IBD) is not yet known. The aim of this study was to investigate whether Sch B has protective effect against dextran sulfate sodium (DSS)-induced colitis in a mouse model. The acute mouse model of IBD was induced by drinking 2.5% DSS water for 5 days. Sch B was administered orally in doses of 10, 40, and 100 mg/kg respectively. It significantly reduced concentration of TNF-α, IL-1β, INF-γ and IL-6 in colon tissue as well as the mRNA expression levels. In addition, we demonstrated that Sch B blocked the phosphorylation of IκBα, nuclear factor-κB (NF-κB) p65, p38 mitogen-activated protein kinase (MAPK), c-Jun NH2-terminal kinase, and extracellular signal regulated kinase in DSS-induced acute colitis. In conclusion, these results indicated that Sch B could exert beneficial effects on experimental IBD induced by DSS and may represent a novel treatment strategy for IBD.

  10. Protease inhibitor-induced nausea and vomiting is attenuated by a peripherally acting, opioid-receptor antagonist in a rat model

    Directory of Open Access Journals (Sweden)

    Mehendale Sangeeta R

    2009-08-01

    Full Text Available Abstract Background Protease inhibitors such as ritonavir can cause nausea and vomiting which is the most common reason for discontinuation. Rats react to nauseous and emetic stimuli by increasing their oral intake of non-nutritive substances like kaolin, known as pica behavior. In this study, we evaluated the effects of methylnaltrexone, a peripherally acting mu-opioid receptor antagonist that does not affect analgesia, on ritonavir-induced nausea and vomiting in a rat pica model. Results We observed that 24 to 48 hr after administration of oral ritonavir 20 mg/kg, kaolin consumption increased significantly in rats (P P P Conclusion These results suggest that methylnaltrexone may have potential clinical utility in reducing nausea and vomiting in HIV patients who take ritonavir.

  11. An anti-interleukin-2 receptor drug attenuates T- helper 1 lymphocytes-mediated inflammation in an acute model of endotoxin-induced uveitis.

    Directory of Open Access Journals (Sweden)

    Salvador Mérida

    Full Text Available The aim of the present study was to evaluate the anti-inflammatory efficacy of Daclizumab, an anti-interleukin-2 receptor drug, in an experimental uveitis model upon a subcutaneous injection of lipopolysaccharide into Lewis rats, a valuable model for ocular acute inflammatory processes. The integrity of the blood-aqueous barrier was assessed 24 h after endotoxin-induced uveitis by evaluating two parameters: cell count and protein concentration in aqueous humors. The histopathology of all the ocular structures (cornea, lens, sclera, choroid, retina, uvea, and anterior and posterior chambers was also considered. Enzyme-linked immunosorbent assays of the aqueous humor samples were performed to quantify the levels of the different chemokine and cytokine proteins. Similarly, a biochemical analysis of oxidative stress-related markers was also assessed. The inflammation observed in the anterior chamber of the eyes when Daclizumab was administered with endotoxin was largely prevented since the aqueous humor protein concentration substantially lowered concomitantly with a significant reduction in the uveal and vitreous histopathological grading. Th1 lymphocytes-related cytokines, such as Interleukin-2 and Interferon-γ, also significantly reduced with related anti-oxidant systems recovery. Daclizumab treatment in endotoxin-induced uveitis reduced Th1 lymphocytes-related cytokines, such as Interleukin-2 and Interferon gamma, by about 60-70% and presented a preventive role in endotoxin-induced oxidative stress. This antioxidant protective effect of Daclizumab may be related to several of the observed Daclizumab effects in our study, including IL-6 cytokine regulatory properties and a substantial concomitant drop in INFγ. Concurrently, Daclizumab treatment triggered a significant reduction in both the uveal histopathological grading and protein concentration in aqueous humors, but not in cellular infiltration.

  12. ENHANCEMENTS TO NATURAL ATTENUATION: SELECTED CASE STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, K; W. H. Albright, W; E. S. Becvar, E; C. H. Benson, C; T. O. Early, T; E. Hood, E; P. M. Jardine, P; M. Lorah, M; E. Majche, E; D. Major, D; W. J. Waugh, W; G. Wein, G; O. R. West, O

    2007-05-15

    In 2003 the US Department of Energy (DOE) embarked on a project to explore an innovative approach to remediation of subsurface contaminant plumes that focused on introducing mechanisms for augmenting natural attenuation to achieve site closure. Termed enhanced attenuation (EA), this approach has drawn its inspiration from the concept of monitored natural attenuation (MNA).

  13. Chlorine signal attenuation in concrete.

    Science.gov (United States)

    Naqvi, A A; Maslehuddin, M; ur-Rehman, Khateeb; Al-Amoudi, O S B

    2015-11-01

    The intensity of prompt gamma-ray was measured at various depths from chlorine-contaminated silica fume (SF) concrete slab concrete specimens using portable neutron generator-based prompt gamma-ray setup. The intensity of 6.11MeV chloride gamma-rays was measured from the chloride contaminated slab at distance of 15.25, 20.25, 25.25, 30.25 and 35.25cm from neutron target in a SF cement concrete slab specimens. Due to attenuation of thermal neutron flux and emitted gamma-ray intensity in SF cement concrete at various depths, the measured intensity of chlorine gamma-rays decreases non-linearly with increasing depth in concrete. A good agreement was noted between the experimental results and the results of Monte Carlo simulation. This study has provided useful experimental data for evaluating the chloride contamination in the SF concrete utilizing gamma-ray attenuation method.

  14. Wogonin, a plant flavone from Scutellariae radix, attenuated ovalbumin-induced airway inflammation in mouse model of asthma via the suppression of IL-4/STAT6 signaling.

    Science.gov (United States)

    Ryu, Eun Kyung; Kim, Tae-Hyun; Jang, Eun Jeong; Choi, Yoon Suk; Kim, Seon Tae; Hahm, Ki Baik; Lee, Ho-Jae

    2015-09-01

    Bronchial asthma is a chronic inflammatory disease of the airways characterized by a marked infiltration of eosinophils at the site of inflammation. Eotaxins are potent chemoattractants for eosinophils and play important roles in pathogenesis of asthma. In the course of screening for eotaxin-3 inhibitors, we found that wogonin showed potent inhibitory activity of interleukin-4 (IL-4)-induced eotaxin-3 expression in BEAS-2B cells. In this study, we examined the effects of wogonin on IL-4/STAT6 signaling pathway and biological implication in a mouse model of asthma. Wogonin inhibited IL-4-induced activation and nuclear translocation of STAT6 which plays a key role in either the transcription of STAT6-response genes or Th2 cytokine-mediated inflammation. Oral administration of wogonin significantly reduced activation of STAT6 in the lung and the expression of eotaxin and RANTES in bronchoalveolar lavage fluids. Histological examination of lung tissue demonstrated that wogonin significantly inhibited allergen-induced eosinophilic inflammation. Administration of wogonin reduced the total IgE and ovalbumin-specific IgE levels compared with the ovalbumin-challenged group. All of these data demonstrated that wogonin could alleviate airway inflammation through inhibition of STAT6 activation induced by Th2 cytokines. Our finding implicates a potential therapeutic value of wogonin in the treatment of asthma through regulation of IL-4/STAT6 signaling pathway. PMID:26388667

  15. Chenodeoxycholic acid attenuates ovalbumin-induced airway inflammation in murine model of asthma by inhibiting the T(H)2 cytokines.

    Science.gov (United States)

    Shaik, Firdose Begum; Panati, Kalpana; Narasimha, Vydyanath R; Narala, Venkata Ramireddy

    2015-08-01

    Asthma is a complex highly prevalent airway disease that is a major public health problem for which current treatment options are inadequate. Recently, farnesoid X receptor (FXR) has been shown to exert anti-inflammatory actions in various disease conditions, but there have been no reported investigations of Chenodeoxycholic acid (CDCA), a natural FXR agonist, in allergic airway inflammation. To test the CDCA effectiveness in airway inflammation, ovalbumin (OVA)-induced acute murine asthma model was established. We found that lung tissue express FXR and CDCA administration reduced the severity of the murine allergic airway disease as assessed by pathological and molecular markers associated with the disease. CDCA treatment resulted in fewer infiltrations of cells into the airspace and peribronchial areas, and decreased goblet cell hyperplasia, mucus secretion and serum IgE levels which was increased in mice with OVA-induced allergic asthma. The CDCA treatment further blocked the secretion of TH2 cytokines (IL-4, IL-5 and IL-13) and proinflammatory cytokine TNF-α indicate that the FXR and its agonists may have potential for treating allergic asthma. PMID:26067554

  16. 散粒体结构中振动能量衰减的模型建立%Vibration energy attenuation model in granular structure

    Institute of Scientific and Technical Information of China (English)

    蒋红英; 鲁进步; 慕青松

    2013-01-01

    基于水平振动荷载下砂石层的实验研究,对于砂石层内部颗粒动力响应情况进行了细观分析,分析了沿深度方向能量快速耗散的变化规律,提出了能量耗散的主要原因是散射和剪阻,运用随机理论推导出了水平振动下颗粒动力响应的概率模型.为散体材料结构的耗能减震深入研究提供了理论基础.%In this paper, based on the experimenter of the gravel layer under the level of vibration load, study on dynamic response in the gravel pile, micro-analysis the dissipation of energy variation along the depth of granular structure. Analysis of the rapid dissipation of energy along the depth, and two reason of scattering and shear resistance are proposed. It use of stochastic theory to deduces the probability model of the particle dynamic response. Which above provides a basis for research of granular material structure of the energy dissipation in-depth study.

  17. A water extract of Samchulkunbi-tang attenuates airway inflammation by inhibiting inos and MMP-9 activities in an ovalbumin-induced murine asthma model

    Directory of Open Access Journals (Sweden)

    Lee Mee Young

    2012-12-01

    Full Text Available Abstract Background In this study, we investigated the effect of Samchulkunbi-tang water extract (SCTE in an established mouse model of ovalbumin (OVA-induced allergic asthma. The effects of SCTE on the production of Th1 and Th2 cytokines, eotaxin, and total and OVA-specific immunoglobulin E, inducible nitric oxide synthase expression, and matrix metalloproteinase-9 activity were measured. Methods Mice were sensitized on days 0 and 14 with an intraperitoneal injection of 20 μg ovalbumin (OVA emulsified in 2 mg aluminum hydroxide in 200 μL PBS buffer. On days 21, 22, and 23, mice received an airway exposure to OVA (1%, w/v, in PBS for 1 h. SCTE was administered orally to mice at doses of 200 and 400 mg/kg per day from days 18 to 23. Results SCTE reduced the number of inflammatory cells, cytokines, and chemokines in bronchoalveolar lavage fluids and iNOS expression and MMP-9 activity in mouse lung tissue. Histological studies using hematoxylin & eosin and periodic acid-schiff staining showed that SCTE substantially inhibited OVA-induced inflammatory cell infiltration in lung tissue and goblet cell hyperplasia in the airway. SCTE also reduced IL-4 and IL-13 expression in concanavalin-A-stimulated splenocytes. These results were similar to those obtained with montelukast as a positive control. Conclusions Collectively, these results suggest that SCTE may be an effective oral treatment for allergic airway inflammation by virtue of its anti-inflammatory activity.

  18. Plasma levels of liver-specific miR-122 is massively increased in a porcine cardiogenic shock model and attenuated by hypothermia.

    Science.gov (United States)

    Andersson, Patrik; Gidlöf, Olof; Braun, Oscar O; Götberg, Matthias; van der Pals, Jesper; Olde, Björn; Erlinge, David

    2012-02-01

    Tissue-specific circulating micro-RNAs (miRNAs) are released into the blood after organ injury. In an ischemic porcine cardiogenic shock model, we investigated the release pattern of cardiac-specific miR-208b and liver-specific miR-122 and assessed the effect of therapeutic hypothermia on their respective plasma levels. Pigs were anesthetized, and cardiogenic shock was induced by inflation of a percutaneous coronary intervention balloon in the proximal left anterior descending artery for 40 min followed by reperfusion. After fulfillment of the predefined shock criteria, the pigs were randomized to hypothermia (33°C, n = 6) or normothermia (38°C, n = 6). Circulating miRNAs were extracted from plasma and measured with quantitative real-time polymerase chain reaction (PCR). Tissue specificity was assessed by miRNA extraction from porcine tissues followed by quantitative real-time PCR. In vitro, the release of miR-122 from a cultured hepatocyte cell line exposed to either hypoxia or acidosis was assessed by real-time PCR. miR-122 was found to be highly liver specific, whereas miR-208b was expressed exclusively in the heart. In the control group, ischemic cardiogenic shock induced a 460,000-fold and a 63,000-fold increase in plasma levels of miR-122 (P cardiogenic shock and that therapeutic hypothermia significantly reduces the levels of miR-122.

  19. Comprehensive study of photon attenuation through different construction matters by Monte Carlo Simulation

    International Nuclear Information System (INIS)

    The main goal of this work is focused on testing the applicability of Geant4 electromagnetic models for studying mass attenuations for different types of composite materials at 59.5, 80, 356, 661.6, 1173.2 and 1332.5 keV photon energies. The simulated results of mass attenuation coefficients were compared with the experimental and theoretical data for the same samples and a good agreement has been observed. The results indicate that this process can be followed to determine the data on the attenuation of gamma-rays with the several energies in different materials. - Highlights: • We measure mass attenuation of gamma rays through different materials. • We model a design of a simple model using Geant-4 Monte Carlo Simulation for calculating mass attenuation of different composite materials. • We compare the model with the theoretical calculation of NIST XCOM code

  20. A Focused Salivary Gland Infection with attenuated MCMV: An Animal Model with Prevention of Pathology Associated with Systemic MCMV Infection1, 2

    Science.gov (United States)

    Pilgrim, Mark J.; Kasman, Laura; Grewal, Jasvir; Bruorton, Mary E.; Werner, Phil; London, Lucille; London, Steven D.

    2010-01-01

    While the salivary gland has been recognized as an important effector site of the common mucosal immune system, a useful model for studying anti-viral salivary gland immune responses in vivo and for exploring the role of the salivary gland within the common mucosal system has been lacking. Murine cytomegalovirus (MCMV) is a beta-herpesvirus that displays a strong tropism for the salivary gland and produces significant morbidity in susceptible mice when introduced by intraperitoneal (i.p.) inoculation. This study tested the hypothesis that MCMV morbidity and pathology could be reduced by injecting the virus directly the submandibular salivary gland (intraglandular (i.g.)), using either in vivo derived MCMV or the less virulent, tissue culture-derived MCMV (tcMCMV). Peak salivary gland viral titers were completely unaffected by infection route (i.p vs. i.g.) after inoculation with either MCMV or tcMCMV. However, i.g. tcMCMV inoculation reduced viremia in all systemic tissues tested compared to i.p. inoculation. Further, systemic organ pathology observed in the liver and spleen after i.p. inoculation with either MCMV or tcMCMV was completely eliminated by i.g. inoculation with tcMCMV. Cellular infiltrates in the salivary glands, after i.p. or i.g. inoculation were composed of both B and T cells, indicating the potential for a local immune response to occur in the salivary gland. These results demonstrate that a focused MCMV infection of the salivary gland without systemic organ pathology is possible using i.g. delivery of tcMCMV. PMID:17320076

  1. Final Project Report - Coupled Biogeochemical Process Evaluation for Conceptualizing Trichloriethylene Co-Metabolism: Co-Metabolic Enzyme Activity Probes and Modeling Co-Metabolism and Attenuation

    Energy Technology Data Exchange (ETDEWEB)

    Starr, Robert C; Orr, Brennon R; Lee, M Hope; Delwiche, Mark

    2010-02-26

    Trichloroethene (TCE) (also known as trichloroethylene) is a common contaminant in groundwater. TCE is regulated in drinking water at a concentration of 5 µg/L, and a small mass of TCE has the potential to contaminant large volumes of water. The physical and chemical characteristics of TCE allow it to migrate quickly in most subsurface environments, and thus large plumes of contaminated groundwater can form from a single release. The migration and persistence of TCE in groundwater can be limited by biodegradation. TCE can be biodegraded via different processes under either anaerobic or aerobic conditions. Anaerobic biodegradation is widely recognized, but aerobic degradation is less well recognized. Under aerobic conditions, TCE can be oxidized to non hazardous conditions via cometabolic pathways. This study applied enzyme activity probes to demonstrate that cometabolic degradation of TCE occurs in aerobic groundwater at several locations, used laboratory microcosm studies to determine aerobic degradation rates, and extrapolated lab-measured rates to in situ rates based on concentrations of microorganisms with active enzymes involved in cometabolic TCE degradation. Microcosms were constructed using basalt chips that were inoculated with microorganisms to groundwater at the Idaho National Laboratory Test Area North TCE plume by filling a set of Flow-Through In Situ Reactors (FTISRs) with chips and placing the FTISRs into the open interval of a well for several months. A parametric study was performed to evaluate predicted degradation rates and concentration trends using a competitive inhibition kinetic model, which accounts for competition for enzyme active sites by both a growth substrate and a cometabolic substrate. The competitive inhibition kinetic expression was programmed for use in the RT3D reactive transport package. Simulations of TCE plume evolution using both competitive inhibition kinetics and first order decay were performed.

  2. Vorinostat, an HDAC inhibitor attenuates epidermoid squamous cell carcinoma growth by dampening mTOR signaling pathway in a human xenograft murine model

    Energy Technology Data Exchange (ETDEWEB)

    Kurundkar, Deepali; Srivastava, Ritesh K.; Chaudhary, Sandeep C. [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States); Ballestas, Mary E. [Department of Pediatrics Infectious Disease, Children' s of Alabama, School of Medicine, University of Alabama at Birmingham, AL (United States); Kopelovich, Levy [Division of Cancer Prevention, National Cancer Institute, 6130 Executive Blvd., Suite 2114, Bethesda, MD 20892 (United States); Elmets, Craig A. [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, 1530 3rd Avenue South, VH 509, Birmingham, AL 35294-0019 (United States)

    2013-01-15

    Histone deacetylase (HDAC) inhibitors are potent anticancer agents and show efficacy against various human neoplasms. Vorinostat is a potent HDAC inhibitor and has shown potential to inhibit growth of human xenograft tumors. However, its effect on the growth of skin neoplasm remains undefined. In this study, we show that vorinostat (2 μM) reduced expression of HDAC1, 2, 3, and 7 in epidermoid carcinoma A431 cells. Consistently, it increased acetylation of histone H3 and p53. Vorinostat (100 mg/kg body weight, IP) treatment reduced human xenograft tumor growth in highly immunosuppressed nu/nu mice. Histologically, the vorinostat-treated tumor showed features of well-differentiation with large necrotic areas. Based on proliferating cell nuclear antigen (PCNA) staining and expression of cyclins D1, D2, E, and A, vorinostat seems to impair proliferation by down-regulating the expression of these proteins. However, it also induced apoptosis. The mechanism by which vorinostat blocks proliferation and makes tumor cells prone to apoptosis, involved inhibition of mTOR signaling which was accompanied by reduction in cell survival AKT and extracellular-signal regulated kinase (ERK) signaling pathways. Our data provide a novel mechanism-based therapeutic intervention for cutaneous squamous cell carcinoma (SCC). Vorinostat may be utilized to cure skin neoplasms in organ transplant recipient (OTR). These patients have high morbidity and surgical removal of these lesions which frequently develop in these patients, is difficult. -- Highlights: ► Vorinostat reduces SCC growth in a xenograft murine model. ► Vorinostat dampens proliferation and induces apoptosis in tumor cells. ► Diminution in mTOR, Akt and ERK signaling underlies inhibition in proliferation. ► Vorinostat by inhibiting HDACs inhibits epithelial–mesenchymal transition.

  3. Rearing in an enriched environment attenuated hyperactivity and inattention in the Spontaneously Hypertensive Rats, an animal model of Attention-Deficit Hyperactivity Disorder.

    Science.gov (United States)

    Botanas, Chrislean Jun; Lee, Hyelim; de la Peña, June Bryan; Dela Peña, Irene Joy; Woo, Taeseon; Kim, Hee Jin; Han, Doug Hyun; Kim, Bung-Nyun; Cheong, Jae Hoon

    2016-03-01

    Attention-deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder, characterized by symptoms of hyperactivity, inattention, and impulsivity. It is commonly treated with psychostimulants that typically begins during childhood and lasts for an extended period of time. However, there are concerns regarding the consequences of chronic psychostimulant treatment; thus, there is a growing search for an alternative management for ADHD. One non-pharmacological management that is gaining much interest is environmental enrichment. Here, we investigated the effects of rearing in an enriched environment (EE) on the expression of ADHD-like symptoms in the Spontaneously Hypertensive Rats (SHRs), an animal model of ADHD. SHRs were reared in EE or standard environment (SE) from post-natal day (PND) 21 until PND 49. Thereafter, behavioral tests that measure hyperactivity (open field test [OFT]), inattention (Y-maze task), and impulsivity (delay discounting task) were conducted. Additionally, electroencephalography (EEG) was employed to assess the effects of EE on rat's brain activity. Wistar-Kyoto (WKY) rats, the normotensive counterpart of the SHRs, were used to determine whether the effects of EE were specific to a particular genetic background. EE improved the performance of the SHRs and WKY rats in the OFT and Y-maze task, but not the delay discounting task. Interestingly, EE induced significant EEG changes in WKY rats, but not in the SHRs. These findings show that rearing environment may play a role in the expression of ADHD-like symptoms in the SHRs and that EE may be considered as a putative complementary approach in managing ADHD symptoms.

  4. Felodipine attenuates vascular inflammation in a fructose-induced rat model of metabolic syndrome via the inhibition of NF-кB activation

    Institute of Scientific and Technical Information of China (English)

    Hong-wei TAN; Shan-shun XING; Xiu-ping BI; Li LI; Hui-ping GONG; Ming ZHONG; Yun ZHANG; Wei ZHANG

    2008-01-01

    Aim:Metabolic syndrome is associated with an increased incidence of athero-sclerosis. Clinical studies have shown that calcium channel blockers (CCB) inhibit the progression of atherosclerosis. However, the underlying mechanism is unclear. We investigated the inhibitory effect of felodipine on adhesion mo-lecular expression and macrophage infiltration in the aorta of high fructose-fed rats (FFR). Methods: Male Wistar rats were given 10% fructose in drinking water. After 32 weeks of high fructose feeding, they were treated with felodipine (5 mg·kg-1·d-1) for 6 weeks. The control rats were given a normal diet and water. The aortic expression of intercellular adhesion molecule-1 (ICAM-1) and vas-cular cell adhesion molecule-1 (VCAM-1) and the infiltration of macrophages were measured by real-time RT-PCR and/or immunohistochemistry. NF-кB activity was measured by electrophoretic mobility shift assay (EMSA). Results: After 32 weeks of high fructose feeding, FFR displayed increased body weight, systolic blood pressure (SBP), serum insulin, and triglycerides when compared with the control rats. The aortic expressions of ICAM-I and VCAM-1 were significantly increased in FFR than in the control rats and accompanied by the increased activity of NF-кB. FFR also showed significantly increased CD68-positive macrophages in the aortic wall. After treatment with felodipine, SBP, serum insulin, and the homeostasis model assessment decreased significantly. In addition to reducing ICAM-1 and VCAM-1, felodipine decreased macrophages in the aortic wall. EMSA revealed that felodipine inhibited NF-кB activation in FFR. Conclusion: Felodipine inhibited vessel wall inflammation. The inhibition of NF-кB may be involved in the modulation of vascular inflammatory response by CCB in metabolic syndrome.

  5. Vorinostat, an HDAC inhibitor attenuates epidermoid squamous cell carcinoma growth by dampening mTOR signaling pathway in a human xenograft murine model

    International Nuclear Information System (INIS)

    Histone deacetylase (HDAC) inhibitors are potent anticancer agents and show efficacy against various human neoplasms. Vorinostat is a potent HDAC inhibitor and has shown potential to inhibit growth of human xenograft tumors. However, its effect on the growth of skin neoplasm remains undefined. In this study, we show that vorinostat (2 μM) reduced expression of HDAC1, 2, 3, and 7 in epidermoid carcinoma A431 cells. Consistently, it increased acetylation of histone H3 and p53. Vorinostat (100 mg/kg body weight, IP) treatment reduced human xenograft tumor growth in highly immunosuppressed nu/nu mice. Histologically, the vorinostat-treated tumor showed features of well-differentiation with large necrotic areas. Based on proliferating cell nuclear antigen (PCNA) staining and expression of cyclins D1, D2, E, and A, vorinostat seems to impair proliferation by down-regulating the expression of these proteins. However, it also induced apoptosis. The mechanism by which vorinostat blocks proliferation and makes tumor cells prone to apoptosis, involved inhibition of mTOR signaling which was accompanied by reduction in cell survival AKT and extracellular-signal regulated kinase (ERK) signaling pathways. Our data provide a novel mechanism-based therapeutic intervention for cutaneous squamous cell carcinoma (SCC). Vorinostat may be utilized to cure skin neoplasms in organ transplant recipient (OTR). These patients have high morbidity and surgical removal of these lesions which frequently develop in these patients, is difficult. -- Highlights: ► Vorinostat reduces SCC growth in a xenograft murine model. ► Vorinostat dampens proliferation and induces apoptosis in tumor cells. ► Diminution in mTOR, Akt and ERK signaling underlies inhibition in proliferation. ► Vorinostat by inhibiting HDACs inhibits epithelial–mesenchymal transition.

  6. Knock out of S1P3 receptor signaling attenuates inflammation and fibrosis in bleomycin-induced lung injury mice model.

    Directory of Open Access Journals (Sweden)

    Ken Murakami

    Full Text Available Sphingosine-1-phosphate (S1P is a bioactive sphingolipid metabolite involved in many critical cellular processes, including proliferation, migration, and angiogenesis, through interaction with a family of five G protein-coupled receptors (S1P1-5. Some reports have implicated S1P as an important inflammatory mediator of the pathogenesis of airway inflammation, but the role of S1P3 in the pathogenesis of lung diseases is not completely understood. We used S1P3-deficient (knockout (KO mice to clarify the role of S1P3 receptor signaling in the pathogenesis of pulmonary inflammation and fibrosis using a bleomycin-induced model of lung injury. On the seventh day after bleomycin administration, S1P3 KO mice exhibited significantly less body weight loss and pulmonary inflammation than wild-type (WT mice. On the 28th day, there was less pulmonary fibrosis in S1P3 KO mice than in WT mice. S1P3 KO mice demonstrated a 56% reduction in total cell count in bronchoalveolar lavage fluid (BALF collected on the seventh day compared with WT mice; however, the differential white blood cell profiles were similar. BALF analysis on the seventh day showed that connective tissue growth factor (CTGF levels were significantly decreased in S1P3 KO mice compared with WT mice, although no differences were observed in monocyte chemotactic protein-1 (MCP-1 or transforming growth factor β1 (TGF-β1 levels. Finally, S1P levels in BALF collected on the 7th day after treatment were not significantly different between WT and S1P3 KO mice. Our results indicate that S1P3 receptor signaling plays an important role in pulmonary inflammation and fibrosis and that this signaling occurs via CTGF expression. This suggests that this pathway might be a therapeutic target for pulmonary fibrosis.

  7. Analysis of multiscale scattering and poroelastic attenuation in a real sedimentary rock sequence

    Science.gov (United States)

    Hackert; Parra

    2000-06-01

    Compressional waves in heterogeneous permeable media experience attenuation from both scattering and induced pore scale flow of the viscous saturating fluid. For a real, finely sampled sedimentary sequence consisting of 255 layers and covering 30 meters of depth, elastic and poroelastic computer models are applied to investigate the relative importance of scattering and fluid-flow attenuation. The computer models incorporate the known porosity, permeability, and elastic properties of the sand/shale sequence in a binary medium, plane layered structure. The modeled elastic scattering attenuation is well described by stochastic medium theory if two-length scale statistics are applied to reflect the relative thickness of the shale layers when compared to the sand layers. Under the poroelastic Biot/squirt flow model, fluid-flow attenuation from the moderate permeability (10(-14) m2) sands may be separated in the frequency domain from the attenuation due to the low permeability (5 x 10(-17) m2) shale layers. Based on these models, the overall attenuation is well approximated by the sum of the scattering attenuation from stochastic medium theory and the volume weighted average of the attenuations of the sequence member rocks. These results suggest that a high permeability network of sediments or fractures in a lower permeability host rock may have a distinct separable attenuation signature, even if the overall volume of high permeability material is low. Depending on the viscosity of the saturating fluid, the magnitude of the flow-based attenuation can dominate or be dominated by the scattering attenuation at typical sonic logging frequencies (approximately 10 kHz).

  8. Characteristics of coda wave attenuation in Yunnan area

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The characteristic of seismic coda wave attenuation in Yunnan area in 7 frequency-bands range from 1 Hz to 20 Hz was estimated by using the local earthquake's waveform data recorded from 22 Yunnan digital seismic stations.Coda attenuation Q-c1 of each station was firstly calculated by single scattering method. Then, mean free path Le and seismic albedo Bo of each station were calculated, and scattering attenuation Q-1s and intrinsic attenuation Q-1i were separated from total attenuation Q-1t by multiple lapse time window analysis based on the multiple scattering model in uniform random isotropic scattering medium. The attenuating characteristics in Yunnan show that most value of Le are in 10~30 km, with maximal within 2~6 Hz;Bo are about 0.5 at 1~2 Hz, but less than 0.5at other frequency-bands, which means Q-1i is comparable with Q-1s at 1~2 Hz, and after 1~2 Hz, Q-1i is greater than Q-1s and dominates the attenuation process. Q-1c is close to Q-1i at other frequency bands except 1~2 Hz.Results show that Q-1 especially Qs-1 varies spatially, Q-1 in eastern Yunnan zone is a bit higher than in northwestern Yunnan zone;northwestern Yunnan zone higher than southwestern Yunnan zone. Comparing with other results in global, Qs-1 in Yunnan is lower than the global average value among these results, Q-1i is higher than the global average value, and Q-1t lies the middle among these results.

  9. Extended safety and efficacy studies of the attenuated Brucella vaccine candidates 16 M(Delta)vjbR and S19(Delta)vjbR in the immunocompromised IRF-1-/- mouse model.

    Science.gov (United States)

    Arenas-Gamboa, A M; Rice-Ficht, A C; Fan, Y; Kahl-McDonagh, M M; Ficht, T A

    2012-02-01

    The global distribution of brucellosis and high incidence in certain areas of the world warrant the development of a safer and efficacious vaccine. For the past 10 years, we have focused our attention on the development of a safer, but still highly protective, live attenuated vaccine for human and animal use. We have demonstrated the safety and protective efficacy of the vaccine candidates 16 MΔvjbR and S19ΔvjbR against homologous and heterologous challenge in multiple immunocompetent animal models, including mice and deer. In the present study, we conducted a series of experiments to determine the safety of the vaccine candidates in interferon regulatory factor-1-knockout (IRF-1(-/-)) mice. IRF-1(-/-) mice infected with either wild-type Brucella melitensis 16 M or the vaccine strain Brucella abortus S19 succumb to the disease within the first 3 weeks of infection, which is characterized by a marked granulomatous and neutrophilic inflammatory response that principally targets the spleen and liver. In contrast, IRF-1(-/-) mice inoculated with either the 16 MΔvjbR or S19ΔvjbR vaccine do not show any clinical or major pathological changes associated with vaccination. Additionally, when 16 MΔvjbR- or S19ΔvjbR-vaccinated mice are challenged with wild-type Brucella melitensis 16M, the degree of colonization in multiple organs, along with associated pathological changes, is significantly reduced. These findings not only demonstrate the safety and protective efficacy of the vjbR mutant in an immunocompromised mouse model but also suggest the participation of lesser-known mechanisms in protective immunity against brucellosis. PMID:22169089

  10. Vinpocetine attenuates lipid accumulation and atherosclerosis formation

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Yujun [Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, 601 Elmwood Ave, Rochester, NY 14642 (United States); Li, Jian-Dong [Center for Inflammation, Immunity and Infection, and Department of Biology, Georgia State University, Atlanta, GA 30303 (United States); Yan, Chen, E-mail: Chen_Yan@urmc.rochester.edu [Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, 601 Elmwood Ave, Rochester, NY 14642 (United States)

    2013-05-10

    Highlights: •Vinpocetine attenuates hyperlipidemia-induced atherosclerosis in a mouse model. •Vinpocetine antagonizes ox-LDL uptake and accumulation in macrophages. •Vinpocetine blocks the induction of ox-LDL receptor LOX-1 in vitro and in vivo. -- Abstract: Atherosclerosis, the major cause of myocardial infarction and stroke, is a chronic arterial disease characterized by lipid deposition and inflammation in the vessel wall. Cholesterol, in low-density lipoprotein (LDL), plays a critical role in the pathogenesis of atherosclerosis. Vinpocetine, a derivative of the alkaloid vincamine, has long been used as a cerebral blood flow enhancer for treating cognitive impairment. Recent study indicated that vinpocetine is a potent anti-inflammatory agent. However, its role in the pathogenesis of atherosclerosis remains unexplored. In the present study, we show that vinpocetine significantly reduced atherosclerotic lesion formation in ApoE knockout mice fed with a high-fat diet. In cultured murine macrophage RAW264.7 cells, vinpocetine markedly attenuated oxidized LDL (ox-LDL) uptake and foam cell formation. Moreover, vinpocetine greatly blocked the induction of ox-LDL receptor 1 (LOX-1) in cultured macrophages as well as in the LOX-1 level in atherosclerotic lesions. Taken together, our data reveal a novel role of vinpocetine in reduction of pathogenesis of atherosclerosis, at least partially through suppressing LOX-1 signaling pathway. Given the excellent safety profile of vinpocetine, this study suggests vinpocetine may be a therapeutic candidate for treating atherosclerosis.

  11. Vinpocetine attenuates lipid accumulation and atherosclerosis formation

    International Nuclear Information System (INIS)

    Highlights: •Vinpocetine attenuates hyperlipidemia-induced atherosclerosis in a mouse model. •Vinpocetine antagonizes ox-LDL uptake and accumulation in macrophages. •Vinpocetine blocks the induction of ox-LDL receptor LOX-1 in vitro and in vivo. -- Abstract: Atherosclerosis, the major cause of myocardial infarction and stroke, is a chronic arterial disease characterized by lipid deposition and inflammation in the vessel wall. Cholesterol, in low-density lipoprotein (LDL), plays a critical role in the pathogenesis of atherosclerosis. Vinpocetine, a derivative of the alkaloid vincamine, has long been used as a cerebral blood flow enhancer for treating cognitive impairment. Recent study indicated that vinpocetine is a potent anti-inflammatory agent. However, its role in the pathogenesis of atherosclerosis remains unexplored. In the present study, we show that vinpocetine significantly reduced atherosclerotic lesion formation in ApoE knockout mice fed with a high-fat diet. In cultured murine macrophage RAW264.7 cells, vinpocetine markedly attenuated oxidized LDL (ox-LDL) uptake and foam cell formation. Moreover, vinpocetine greatly blocked the induction of ox-LDL receptor 1 (LOX-1) in cultured macrophages as well as in the LOX-1 level in atherosclerotic lesions. Taken together, our data reveal a novel role of vinpocetine in reduction of pathogenesis of atherosclerosis, at least partially through suppressing LOX-1 signaling pathway. Given the excellent safety profile of vinpocetine, this study suggests vinpocetine may be a therapeutic candidate for treating atherosclerosis

  12. On the effectiveness of mangroves in attenuating cyclone induced waves

    NARCIS (Netherlands)

    Narayan, S.; Suzuki, T.; Stive, M.J.F.; Verhagen, H.J.; Ursem, W.N.J.; Ranasinghe, R.

    2010-01-01

    A study of the effectiveness of mangroves in attenuating cyclone- induced waves was done using the SWAN 40.81 numerical model. Hydraulic parameters during extreme events and local mangrove vegetation parameters were estimated for the Kanika Sands mangrove island near the upcoming Dhamra Port in Oris

  13. Seismic motion attenuation relations in Sichuan and adjacent areas

    Institute of Scientific and Technical Information of China (English)

    LEI Jian-cheng; GAO Meng-tan; YU Yan-xiang

    2007-01-01

    The Sichuan and adjacent areas is divided into southwest China region (SWCR) and Sichuan Basin region (SCBR) according to tectonic backgrounds and seismic damage distribution features. 96 modern destructive earthquakes in SWCR and 40 in SCBR are gathered respectively. All their magnitude parameters are checked. Based on the statistic relations between epicentral intensity and magnitude as well as relation between sensible radius and magnitude, the near and far field seismic intensity attenuation features are represented and controlled. And then the seismic intensity attenuation relations along major axis, minor axis and mean axis are established separately. The systematic deviations of surface wave magnitude between China seismograph network and U.S. seismograph network are considered in this paper. By making use of the new attenuation relations of bedrock horizontal ground acceleration response spectrum in west U.S., the attenuation relations of bedrock horizontal ground acceleration response spectrum in SWCR and SCBR are digital transformed based on the attenuation model considering acceleration saturation of distance and magnitude in near field.

  14. The behavioural depression of hippocampal kindled rats is attenuated by subcutaneous and intracerebroventricular naltrexone

    NARCIS (Netherlands)

    Cottrell, G.A.; Nyakas, C.; Bohus, B.

    1984-01-01

    1. Two questions were asked: Does naltrexone attenuate the behavioural depression (BD) in other models of limbic epilepsy besides amygdala kindling? Does intracerebroventricular (ICV) administration produce the same effects as subcutaneous injection i.e., attenuation of the BD. 2. Male wistar rats

  15. Measurment and Interpretation of Seismic Attenuation for Hydrocarbon Exploration

    Energy Technology Data Exchange (ETDEWEB)

    Michael Batzle; Luca Duranti; James Rector; Steve Pride

    2007-12-31

    This research project is the combined effort of several leading research groups. Advanced theoretical work is being conducted at the Lawrence Berkeley National Laboratory. Here, the fundamental controls on loss mechanisms are being examined, primarily by use of numerical models of heterogeneous porous media. At the University of California, Berkeley, forward modeling is combined with direct measurement of attenuation. This forward modeling provides an estimate of the influence of 1/Q on the observed seismic signature. Direct measures of losses in Vertical Seismic Profiles (VSPs) indicate mechanisms to separate scattering versus intrinsic losses. At the Colorado School of Mines, low frequency attenuation measurements are combined with geologic models of deep water sands. ChevronTexaco is our corporate cosponsor and research partner. This corporation is providing field data over the Genesis Field, Gulf of Mexico. In addition, ChevronTexaco has rebuilt and improved their low frequency measurement system. Soft samples representative of the Genesis Field can now be measured for velocities and attenuations under reservoir conditions. Throughout this project we have: Assessed the contribution of mechanical compaction on time-lapse monitoring; Developed and tested finite difference code to model dispersion and attenuation; Heterogeneous porous materials were modeled and 1/Q calculated vs. frequency; 'Self-affine' heterogeneous materials with differing Hurst exponent modeled; Laboratory confirmation was made of meso-scale fluid motion influence on 1/Q; Confirmed theory and magnitude of layer-based scattering attenuation at Genesis and at a shallow site in California; Scattering Q's of between 40 and 80 were obtained; Measured very low intrinsic Q's (2-20) in a partially saturated vadose zone VSP; First field study to separate scattering and intrinsic attenuation in real data set; Revitalized low frequency device at ChevronTexaco's Richmond lab

  16. Numerical simulation of nonlinear acoustic attenuation of multi-component gas mixture

    Institute of Scientific and Technical Information of China (English)

    YAN Shu; WANG Shu

    2009-01-01

    The direct simulation Monte Carlo (DSMC) method was introduced to model the acoustic propagation in multi-component gas mixtures. And a theoretical predictive model of acoustic attenuation was proposed, which does not rely on experiential parameters. The acoustic attenuation spectra of various multi-component gas mixtures, consisting of nitrogen, oxygen, carbon dioxide, methane and water, were estimated by the DSMC method. The sound frequency range of interest is from 8 MHz to 232 MHz. Compared with the result of the relaxation attenuation based on the DL model plus that of the classical attenuation calculated by the Stokes-Kirchhoff formula, the estimations of acoustic attenuation of our model agreed with them. The precision of the model depends upon the understanding of the physical mechanism of molecule collision from which the attenuation arises. In addition, the result of our model shows that the characters of the frequency-dependent acoustic attenuation rely on the composition of the gas mixtures. And this could lead to the development of smart acoustic gas sensors capable of quantitatively determining gas composition in various environments and processes.

  17. Attenuation of neutrons through ducts and labyrinths

    CERN Document Server

    Mauro, Egidio

    2009-01-01

    Monte Carlo simulations have been performed for the attenuation of neutron radiation produced at proton accelerators through ducts and labyrinths of various design, and the results are compared with the predictions made by analytical expressions available in the literature. The results show that the so-called universal transmission curves are an appropriate and simple tool applicable in many situations, when the radiation source is not in direct view of the duct mouth. This is not the case for point sources located in front of the duct. The simulations showed that it is not possible to apply the same models because the transmission factor is strongly dependent on the cross-sectional area of the duct. A universal expression has been derived to estimate the neutron transmission through a straight duct of length d and cross-sectional area A in direct view of the source, which only depends on A and on a small set of numerical coefficients.

  18. Attenuation of ultrasonic waves in rolled metals

    Science.gov (United States)

    Yang, Liyong; Turner, Joseph A.

    2004-12-01

    Scattering of ultrasonic waves in polycrystals with texture is studied in this article. The attenuations of the three wave modes are determined as a function of dimensionless frequency and propagation direction, respectively, for given orientation distribution coefficients (ODCs). The calculation is done in the case of a statistically orthorhombic sample made up of cubic crystallites. The wave propagation and scattering model is formulated by the Dyson equation using an anisotropic Green's function approach. Within the limits of the first-order smoothing approximation, the Dyson equation is solved in the spatial Fourier transform domain. The results presented are shown to be directional dependent, frequency dependent, and especially dependent on the texture coefficients (ODCs) for the quasilongitudinal and two quasishear waves. The theoretical results presented may be used to improve the understanding of the microstructure during recrystallization processes. .

  19. Magnetoelectric Composite Based Microwave Attenuator

    Science.gov (United States)

    Tatarenko, A. S.; Srinivasan, G.

    2005-03-01

    Ferrite-ferroelectric composites are magnetoelectric (ME) due to their response to elastic and electromagnetic force fields. The ME composites are characterized by tensor permittivity, permeability and ME susceptibility. The unique combination of magnetic, electrical, and ME interactions, therefore, opens up the possibility of electric field tunable ferromagnetic resonance (FMR) based devices [1]. Here we discuss an ME attenuator operating at 9.3 GHz based on FMR in a layered sample consisting of lead magnesium niobate-lead titanate bonded to yttrium iron garnet (YIG) film on a gadolinium gallium garnet substrate. Electrical tuning is realized with the application of a control voltage due to ME effect; the shift is 0-15 Oe as E is increased from 0 to 3 kV/cm. If the attenuator is operated at FMR, the corresponding insertion loss will range from 25 dB to 2 dB. 1. S. Shastry and G. Srinivasan, M.I. Bichurin, V.M. Petrov, A.S. Tatarenko. Phys. Rev. B, 70 064416 (2004). - supported by grants the grants from the National Science Foundation (DMR-0302254), from Russian Ministry of Education (Å02-3.4-278) and from Universities of Russia Foundation (UNR 01.01.026).

  20. Active acoustic leak detection for LMFBR steam generator. Sound attenuation due to bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Kumagai, Hiromichi; Sakuma, Toshio [Central Research Inst. of Electric Power Industry, Komae, Tokyo (Japan). Komae Research Lab.

    1995-06-01

    In the steam generators (SG) of LMFBR, it is necessary to detect the leakage of water from tubes of heat exchangers as soon as it occurs. The active acoustic detection method has drawn general interest owing to its short response time and reduction of the influence of background noise. In this paper, the application of the active acoustic detection method for SG is proposed, and sound attenuation by bubbles is investigated experimentally. Furthermore, using the SG sector model, sound field characteristics and sound attenuation characteristics due to injection of bubbles are studied. It is clarified that the sound attenuation depends upon bubble size as well as void fraction, that the distance attenuation of sound in the SG model containing heat transfer tubes is 6dB for each two-fold increase of distance, and that emitted sound attenuates immediately upon injection of bubbles. (author).

  1. Evidence of magma activation beneath the Lunayyir basaltic field (Saudi Arabia from attenuation tomography

    Directory of Open Access Journals (Sweden)

    I. Koulakov

    2014-06-01

    Full Text Available We present a seismic attenuation model for the crust beneath the Cenozoic basaltic field of Lunayyir (western Saudi Arabia, where a strong seismic swarm occurred in 2009. The tomography inversion uses the envelope shape of the S wave seismograms from over 300 strong events (M > 3.5. The resulting attenuation structures appear to be consistent with the distribution of seismic velocities. The obtained 3-D attenuation model distinguishes the low-attenuation zones down to 5 km depth corresponding to the rigid basaltic cover. At greater depths, we detect a high-attenuation anomaly coinciding with the main seismicity cluster. We propose that this zone corresponds to the upper part of the conduit area ascending from deeper magma sources. According to the distributions of local events, fluids and melts from this conduit appear to reach a depth of ~2 km, but were not able to reach the surface and cause the eruption in 2009.

  2. Wave Dispersion and Attenuation in Partially Saturated Sandstones

    Institute of Scientific and Technical Information of China (English)

    NIE Jian-Xin; YANG Ding-Hui; YANG Hui-Zhu

    2004-01-01

    @@ We investigate the wave dispersion and attenuation in partially water-saturated sandstones based on the improved Biot/squirt (BISQ) model in which the saturation is introduced. Numerical experiments indicate that the phase velocity of the fast P-wave decreases as the saturation increases in the low-frequency range (102-104 Hz), and reaches the minimum at the full-saturation state. The behaviour of the phase velocity varying with the saturation in the high-frequency range (104-106 Hz), however, is opposite to that in the low-frequency range. The peak value of P-wave attenuation increases with increasing saturation, and is the maximum at the fully saturated state. Numerical models and experiments show that the improved BISQ model is better than the traditional Gassmann-Biot model.

  3. Study of rain attenuation in Ka band for satellite communication in South Korea

    Science.gov (United States)

    Shrestha, Sujan; Choi, Dong-You

    2016-10-01

    The important factor to be considered in the link budget estimation for satellite communication systems, operating at frequencies above 10 GHz is the rain attenuation. Scattering and absorption are the main concern for system designers at these frequency bands. This has resulted in the need for suitable prediction models that can best provide estimates of attenuation due to rain with available information of rain attenuation data. Researchers have developed models that can be used to estimate 1-min rainfall attenuation distribution for earth space link but there is still some confusion with regard to choosing the right model to predict attenuation for the location of interest. In this context, the existing prediction models need to be tested against the measured results. This paper presents studies on rain attenuation at 19.8 GHz, which specifies the performance parameters for Ka-Band under earth space communication system. It presents the experimental result of rain rates and rain-induced attenuation in 19.8 and 20.73 GHz for vertical and circular polarization respectively. The received signal data for rain attenuation and rain rate were collected at 10 s intervals over a three year periods from 2013 to 2015. The data highlights the impact of clear air variation and rain fade loss. Rain rate data was measured through OTT Parsivel. During the observation period, rain rates of about 50 mm/h and attenuation values of 11.6 dB for 0.01% of the time were noted. The experimental link was set up at Korea Radio Promotion Association, Mokdong, Seoul. Out of several models, this paper present discussion and comparison of ITU-R P.618-12, Unified Method, Dissanayake Allnutt and Haidara (DAH), Simple Attenuation (SAM), Crane Global and Ramachandran and Kumar models. The relative error margin of 27.51, 89.84,72.46% and 67.24, 130.84, 166.48% are obtained for 0.1%, 0.01% and 0.001% of the time for 19.8 and 20.73 GHz under vertical and circular polarization respectively from ITU

  4. Attenuation of Rayleigh Surface Waves in a Porous Material

    Institute of Scientific and Technical Information of China (English)

    DEBBOUB Salima; BOUMA(I)ZA Youcef; BOUDOUR Amar; TAHRAOUI Tarek

    2012-01-01

    Using acoustic microscopy at higher frequency,we show the velocity evolutions of surface acoustic waves,in particular Rayleigh waves that depend on porosity for a mesoporous silicon layer.The velocities are obtained from different V(z) curves,which are determined experimentally at a frequency of 600MHz.The analysis of V(z) data yields attenuation that is directly dependent on porosity.On the other hand,αN attenuation has been modeled and allows us to investigate its influence on the velocity VR of the propagation for Rayleigh waves.%Using acoustic microscopy at higher frequency, we show the velocity evolutions of surface acoustic waves, in particular Rayleigh waves that depend on porosity for a mesoporous silicon layer. The velocities are obtained from different V(z) curves, which are determined experimentally at a frequency of 600 MHz. The analysis of V(z) data yields attenuation that is directly dependent on porosity. On the other hand, αN attenuation has been modeled and allows us to investigate its influence on the velocity VR of the propagation for Rayleigh waves.

  5. PAUT inspection of copper canister: Structural attenuation and POD formulation

    Science.gov (United States)

    Gianneo, A.; Carboni, M.; Mueller, C.; Ronneteg, U.

    2016-02-01

    For inspection of thick-walled (50mm) copper canisters for final disposal of spent nuclear fuel in Sweden, ultrasonic inspection using phased array technique (PAUT) is applied. Because thick-walled copper is not commonly used as a structural material, previous experience on Phased Array Ultrasonic Testing for this type of application is limited. The paper presents the progress in understanding the amplitudes and attenuation changes acting on the Phased Array Ultrasonic Testing inspection of copper canisters. Previous studies showed the existence of a low pass filtering effect and a heterogeneous grain size distribution along the depth, thus affecting both the detectability of defects and their "Probability of Detection" determination. Consequently, the difference between the first and second back wall echoes were not sufficient to determine the local attenuation (within the inspection range), which affects the signal response for each individual defect. Experimental evaluation of structural attenuation was carried out onto step-wedge samples cut from full-size, extruded and pierced & drawn, copper canisters. Effective attenuation values has been implemented in numerical simulations to achieve a Multi Parameter Probability of Detection and to formulate a Model Assisted Probability of Detection through a Monte-Carlo extraction model.

  6. Ultrasound fields in an attenuating medium

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Gandhi,, D; O'Brien,, W.D., Jr.

    1993-01-01

    Ultrasound fields propagating in tissue will undergo changes in shape not only due to diffraction, but also due to the frequency dependent attenuation. Linear fields can be fairly well predicted for a non-attenuating medium like water by using the Tupholme-Stepanishen method for calculating...... it into a frequency dependent part and frequency independent part. The latter results in an attenuation factor that is multiplied onto the responses from the individual elements, and the frequency dependent part is handled by attenuating the basic one-dimensional pulse. The influence on ultrasound fields from...

  7. Occurrence and in-stream attenuation of wastewater-derived pharmaceuticals in Iberian rivers.

    Science.gov (United States)

    Acuña, Vicenç; von Schiller, Daniel; García-Galán, Maria Jesús; Rodríguez-Mozaz, Sara; Corominas, Lluís; Petrovic, Mira; Poch, Manel; Barceló, Damià; Sabater, Sergi

    2015-01-15

    A multitude of pharmaceuticals enter surface waters via discharges of wastewater treatment plants (WWTPs), and many raise environmental and health concerns. Chemical fate models predict their concentrations using estimates of mass loading, dilution and in-stream attenuation. However, current comprehension of the attenuation rates remains a limiting factor for predictive models. We assessed in-stream attenuation of 75 pharmaceuticals in 4 river segments, aiming to characterize in-stream attenuation variability among different pharmaceutical compounds, as well as among river segments differing in environmental conditions. Our study revealed that in-stream attenuation was highly variable among pharmaceuticals and river segments and that none of the considered pharmaceutical physicochemical and molecular properties proved to be relevant in determining the mean attenuation rates. Instead, the octanol-water partition coefficient (Kow) influenced the variability of rates among river segments, likely due to its effect on sorption to sediments and suspended particles, and therefore influencing the balance between the different attenuation mechanisms (biotransformation, photolysis, sorption, and volatilization). The magnitude of the measured attenuation rates urges scientists to consider them as important as dilution when aiming to predict concentrations in freshwater ecosystems.

  8. Ultrasonic attenuation in cuprate superconductors

    Indian Academy of Sciences (India)

    T Gupta; D M Gaitonde

    2002-05-01

    We calculate the longitudinal ultrasonic attenuation rate (UAR) in clean d-wave superconductors in the Meissner and the mixed phases. In the Meissner phase we calculate the contribution of previously ignored processes involving the excitation of a pair of quasi-holes or quasi-particles. There is a contribution ∝ in the regime B ≪ F ≪ 0 and a contribution ∝ 1/ in the regime F ≪ B ≪ 0. We find that these contributions to the UAR are large and cannot be ignored. In the mixed phase, using a semi-classical description, we calculate the electronic quasi-particle contribution to the UAR which at very low , has a independent term proportional to $\\sqrt{H}$.

  9. Attenuation characteristics of gypsum wallboard

    International Nuclear Information System (INIS)

    Increased cost of lead is promoting enhanced usage of common building materials for shielding in diagnostic medical and dental facilities where only a few half-value layers (HVLs) are needed. Attenuation of primary beam X-ray photons in gypsum wallboard as a function of kVp, filtration, and wallboard thickness have been measured. Findings, obtained using a Victoreen 555 with an 0.1 DAS probe in poor geometry, are substantially in agreement with the sparse data in the literature but extend to thicker wall configurations and different kVp and filtration parameters. These findings are of value in maximizing the benefit/cost ratio for diagnostic shielding, and strengthen the conviction that, where used for shielding purposes, common building materials must be installed carefully and HVL-depth dependence considered thoroughly. (author)

  10. Suspended sediment profiles derived from spectral attenuation coefficients measurements using neural network method

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, G.; Suresh, T.; Matondkar, S.G.P.; Desa, E.; Kamath, S.S.

    total suspended matter values from water samples obtained at discrete depths at the same location. An artificial neural network (ANN) model has been used to derive suspended matter from the spectral values of beam attenuation coefficients measured using...

  11. Lung attenuation measurements in healthy young adults.

    NARCIS (Netherlands)

    Smit, H.J.M.; Golding, R.P.; Schramel, F.M.N.H.; Devillé, W.L.; Manoliu, R.A.; Postmus, P.E.

    2003-01-01

    Background: High-resolution computed tomography (HRCT) attenuation measurements may be more sensitive in finding early emphysematous changes in relatively young subjects than lung function measurements. Objectives: To define lung attenuation parameters in smokers and never-smokers. Methods: A prospe

  12. Simple parameterization of nuclear attenuation data

    CERN Document Server

    Akopov, N; Akopov, Z

    2007-01-01

    Based on the nuclear attenuation data obtained by the HERMES experiment on nitrogen and krypton nuclei, it is shown that the nuclear attenuation $R_M^{h}$ can be parametrised in a form of a linear polynomial $P_1=a_{11}$ + $\\tau a_{12}$, where $\\tau$ is the formation time, which depends on the energy of the virtual photon $\

  13. Engineering attenuated virulence of a Theileria annulata-infected macrophage.

    Directory of Open Access Journals (Sweden)

    Nadia Echebli

    Full Text Available Live attenuated vaccines are used to combat tropical theileriosis in North Africa, the Middle East, India, and China. The attenuation process is empirical and occurs only after many months, sometimes years, of in vitro culture of virulent clinical isolates. During this extensive culturing, attenuated lines lose their vaccine potential. To circumvent this we engineered the rapid ablation of the host cell transcription factor c-Jun, and within only 3 weeks the line engineered for loss of c-Jun activation displayed in vitro correlates of attenuation such as loss of adhesion, reduced MMP9 gelatinase activity, and diminished capacity to traverse Matrigel. Specific ablation of a single infected host cell virulence trait (c-Jun induced a complete failure of Theileria annulata-transformed macrophages to disseminate, whereas virulent macrophages disseminated to the kidneys, spleen, and lungs of Rag2/γC mice. Thus, in this heterologous mouse model loss of c-Jun expression led to ablation of dissemination of T. annulata-infected and transformed macrophages. The generation of Theileria-infected macrophages genetically engineered for ablation of a specific host cell virulence trait now makes possible experimental vaccination of calves to address how loss of macrophage dissemination impacts the disease pathology of tropical theileriosis.

  14. Body Wave Crustal Attenuation Characteristics in the Garhwal Himalaya, India

    Science.gov (United States)

    Negi, Sanjay S.; Paul, Ajay; Joshi, Anand; Kamal

    2015-06-01

    We estimate frequency-dependent attenuation of P and S waves in Garhwal Himalaya using the extended coda normalization method for the central frequencies 1.5, 2, 3, 4, 6, 8, 10, 12, and 16 Hz, with earthquake hypocentral distance ranging from 27 to 200 km. Forty well-located local earthquake waveforms were used to study the seismic attenuation characteristics of the Garhwal Himalaya, India, as recorded by eight stations operated by Wadia Institute of Himalayan Geology, Dehradun, India, from 2007 to 2012. We find frequency-dependent P and S wave quality factors as defined by the relations Q P = 56 ± 8 f 0.91±0.002 and Q S = 151 ± 8 f 0.84±0.002 by fitting a power-law frequency dependence model for the estimated values over the whole region. Both the Q P and Q S values indicate strong attenuation in the crust of Garhwal Himalaya. The ratio of Q S/ Q P > 1 obtained for the entire analyzed frequency range suggests that the scattering loss is due to a random and high degree of heterogeneities in the earth medium, playing an important role in seismic wave attenuation in the Himalayan crust.

  15. Live attenuated S. Typhimurium vaccine with improved safety in immuno-compromised mice.

    Directory of Open Access Journals (Sweden)

    Balamurugan Periaswamy

    Full Text Available Live attenuated vaccines are of great value for preventing infectious diseases. They represent a delicate compromise between sufficient colonization-mediated adaptive immunity and minimizing the risk for infection by the vaccine strain itself. Immune defects can predispose to vaccine strain infections. It has remained unclear whether vaccine safety could be improved via mutations attenuating a vaccine in immune-deficient individuals without compromising the vaccine's performance in the normal host. We have addressed this hypothesis using a mouse model for Salmonella diarrhea and a live attenuated Salmonella Typhimurium strain (ssaV. Vaccination with this strain elicited protective immunity in wild type mice, but a fatal systemic infection in immune-deficient cybb(-/-nos2(-/- animals lacking NADPH oxidase and inducible NO synthase. In cybb(-/-nos2(-/- mice, we analyzed the attenuation of 35 ssaV strains carrying one additional mutation each. One strain, Z234 (ssaV SL1344_3093, was >1000-fold attenuated in cybb(-/-nos2(-/- mice and ≈100 fold attenuated in tnfr1(-/- animals. However, in wt mice, Z234 was as efficient as ssaV with respect to host colonization and the elicitation of a protective, O-antigen specific mucosal secretory IgA (sIgA response. These data suggest that it is possible to engineer live attenuated vaccines which are specifically attenuated in immuno-compromised hosts. This might help to improve vaccine safety.

  16. An ice-sheet-wide framework for englacial attenuation from ice-penetrating radar data

    Science.gov (United States)

    Jordan, T. M.; Bamber, J. L.; Williams, C. N.; Paden, J. D.; Siegert, M. J.; Huybrechts, P.; Gagliardini, O.; Gillet-Chaulet, F.

    2016-07-01

    Radar inference of the bulk properties of glacier beds, most notably identifying basal melting, is, in general, derived from the basal reflection coefficient. On the scale of an ice sheet, unambiguous determination of basal reflection is primarily limited by uncertainty in the englacial attenuation of the radio wave, which is an Arrhenius function of temperature. Existing bed-returned power algorithms for deriving attenuation assume that the attenuation rate is regionally constant, which is not feasible at an ice-sheet-wide scale. Here we introduce a new semi-empirical framework for deriving englacial attenuation, and, to demonstrate its efficacy, we apply it to the Greenland Ice Sheet. A central feature is the use of a prior Arrhenius temperature model to estimate the spatial variation in englacial attenuation as a first guess input for the radar algorithm. We demonstrate regions of solution convergence for two input temperature fields and for independently analysed field campaigns. The coverage achieved is a trade-off with uncertainty and we propose that the algorithm can be "tuned" for discrimination of basal melt (attenuation loss uncertainty ˜ 5 dB). This is supported by our physically realistic ( ˜ 20 dB) range for the basal reflection coefficient. Finally, we show that the attenuation solution can be used to predict the temperature bias of thermomechanical ice sheet models and is in agreement with known model temperature biases at the Dye 3 ice core.

  17. Genetically Attenuated Plasmodium berghei Liver Stages Persist and Elicit Sterile Protection Primarily via CD8 T Cells

    OpenAIRE

    Mueller, Ann-Kristin; Deckert, Martina; Heiss, Kirsten; Goetz, Kristin; Matuschewski, Kai; Schlüter, Dirk

    2007-01-01

    Live-attenuated Plasmodium liver stages remain the only experimental model that confers complete sterile protection against malaria. Irradiation-attenuated Plasmodium parasites mediate protection primarily by CD8 T cells. In contrast, it is unknown how genetically attenuated liver stage parasites provide protection. Here, we show that immunization with uis3(−) sporozoites does not cause breakthrough infection in T and B-cell-deficient rag1−/− and IFN-γ−/− mice. However, protection was abolish...

  18. A Simulation of the Optical Attenuation of TPB Coated Light-guide Detectors

    CERN Document Server

    Jones, B J P

    2013-01-01

    This note describes simple simulations which were performed in order to understand the attenuation behaviors of acrylic light-guides operated in air and argon, which were characterized in \\cite{Baptista:2012bf}. Whilst these simulations are only at the level of sophistication of a toy model, they illustrate interesting non-exponential light attenuation effects and the differences between operating light-guide based detectors in argon and air environments. We investigate the effects of surface absorption, surface roughness and wavelength dependence, and use a model tuned on the light-guide attenuation curve measured in air to make a prediction of the light-guide attenuation curve in argon. This curve is compared with data from a liquid argon test stand, and an improvement over a simple exponential model is observed.

  19. A simulation of the optical attenuation of TPB coated light-guide detectors

    Science.gov (United States)

    Jones, B. J. P.

    2013-10-01

    This note is provided as a supplementary section to accompany the paper [1] which has been included in these proceedings. It describes some simple simulations which were performed in order to understand the attenuation behaviors of acrylic light-guides operated in air and argon, which were characterized in [2]. Whilst these simulations are only at the level of sophistication of a toy model, they illustrate interesting non-exponential light attenuation effects and the differences between operating light-guide based detectors in argon and air environments. We investigate the effects of surface absorption, surface roughness and wavelength dependence, and use a model tuned on the light-guide attenuation curve measured in air to make a prediction of the light-guide attenuation curve in argon. This curve is compared with data from a liquid argon test stand, and an improvement over a simple exponential model is observed.

  20. Live attenuated intranasal influenza vaccine.

    Science.gov (United States)

    Esposito, Susanna; Montinaro, Valentina; Groppali, Elena; Tenconi, Rossana; Semino, Margherita; Principi, Nicola

    2012-01-01

    Annual vaccination is the most effective means of preventing and controlling influenza epidemics, and the traditional trivalent inactivated vaccine (TIV) is by far the most widely used. Unfortunately, it has a number of limitations, the most important of which is its poor immunogenicity in younger children and the elderly, the populations at greatest risk of severe influenza. Live attenuated influenza vaccine (LAIV) has characteristics that can overcome some of these limitations. It does not have to be injected because it is administered intranasally. It is very effective in children and adolescents, among whom it prevents significantly more cases of influenza than the traditional TIV. However, its efficacy in adults has not been adequately documented, which is why it has not been licensed for use by adults by the European health authorities. LAIV is safe and well tolerated by children aged > 2 y and adults, but some concerns arisen regarding its safety in younger children and subjects with previous asthma or with recurrent wheezing. Further studies are needed to solve these problems and to evaluate the possible role of LAIV in the annual vaccination of the general population.

  1. Beta attenuation transmission system (BATS)

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, R.C.; Fullbright, H.J.

    1977-01-01

    The beta attenuation transmission system (BATS) is an automated radiation gauge designed for quantitative measurement of component thickness in explosive detonators. The BATS was designed and built by Group M-1, the Nondestructive Testing Group, of the Los Alamos Scientific Laboratory to measure the areal thickness, in mg/cm/sup 2/, of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A /sup 90/Sr source is collimated by a 0.25 x 1.59-mm slit, and the transmitted beta-particle flux is detected by a plastic scintillator, coupled to a photomultiplier tube. The detonator is transported through the radiation beam by a leadscrew, ballnut, stepping-motor combination. Continuous analog position data are available, derived from the output from a linear-actuated potentiometer attached to the scanner. A linear electrometer amplifies the detected signal, which is then integrated for a preselected time, to obtain the desired statistical accuracy. A microprocessor (..mu..P) is used to control the scanner position and to make the data readings at the assigned positions. The data are stored, and, at the completion of the scan, are processed into the desired format. The final answer is displayed to the operator or output to a peripheral device for permanent record. The characteristics of the radiation source, the collimator, the signal detection and conditioning, and the final results are described in detail. The scanner and the microprocessor control system are briefly outlined.

  2. Attenuation of diacylglycerol second messengers

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, W.R.; Ganong, B.R.; Bell, R.M.

    1986-05-01

    Diacylglycerol(DAG) derived from phosphatidylinositol activates protein kinase C in agonist-stimulated cells. At least two pathways may contribute to the attenuation of the DAG signal: (1) phosphorylation to phosphatidic acid(PA) by DAG kinase(DGK), and (2) deacylation by DAG and monoacylglycerol lipases. A number of DAG analogs were tested as substrates and inhibitors of partially purified pig brain DGK. Two analogs were potent inhibitors in vitro, 1-monooleoylglycerol(MOG,K/sub I/ = 91 ..mu..M) and diotanoylethyleneglycol (diC/sub 8/EG, K/sub I/ = 58 ..mu..M). These compounds were tested in human platelets. DiC/sub 8/EG inhibited (70 - 100%) (/sup 32/P/sub i/) incorporation into PA in thrombin-stimulated platelets. Under these conditions the DAG signal was somewhat long-lived but was still metabolized, presumably by the lipase pathway. MOG treatment elevated DAG levels up to 4-fold in unstimulated platelets. The DAG formed was in a pool where it did not activate protein kinase C. Thrombin-stimulation of MOG-treated platelets resulted in DAG levels 10-fold higher than control platelets. This appears to be due to the inability of these platelets to metabolize agonist-linked DAG via the lipase pathway. The development of specific inhibitors of DAG kinase and DAG lipase, in conjunction with mass quantification of DAG levels as used here, will provide further insights into the regulation of DAG second messengers.

  3. Extragalactic Background Light and Gamma-Ray Attenuation

    OpenAIRE

    Primack, Joel R.; Dominguez, Alberto; Gilmore, Rudy C.; Somerville, Rachel S.

    2011-01-01

    Data from (non-) attenuation of gamma rays from active galactic nuclei (AGN) and gamma ray bursts (GRBs) give upper limits on the extragalactic background light (EBL) from the UV to the mid-IR that are only a little above the lower limits from observed galaxies. These upper limits now rule out some EBL models and purported observations, with improved data likely to provide even stronger constraints. We present EBL calculations both based on multiwavelength observations of thousands of galaxie...

  4. Clarithromycin attenuates mastectomy-induced acute inflammatory response

    OpenAIRE

    Chow, Louis W. C.; Yuen, Kwok-Yung; Woo, Patrick C. Y.; Wei, William I.

    2000-01-01

    Based on the observation that administration of clarithromycin led to an attenuation of the inflammatory response induced by surgical trauma in a guinea pig model, we investigated the potential beneficial effects of clarithromycin on the local and systemic inflammatory response in patients undergoing mastectomy in an open-label prospective study. During a 16-month period, 54 patients who underwent mastectomy were randomly divided into two groups. In one group, the patients received oral clari...

  5. Guided wave attenuation in coated pipes buried in sand

    Science.gov (United States)

    Leinov, Eli; Cawley, Peter; Lowe, Michael J. S.

    2016-02-01

    Long-range guided wave testing (GWT) is routinely used for the monitoring and detection of corrosion defects in above ground pipelines in various industries. The GWT test range in buried, coated pipelines is greatly reduced compared to aboveground pipelines due to energy leakage into the embedding soil. In this study, we aim to increase test ranges for buried pipelines. The effect of pipe coatings on the T(0,1) and L(0,2) guided wave attenuation is investigated using a full-scale experimental apparatus and model predictions. Tests are performed on a fusion-bonded epoxy (FBE)-coated 8" pipe, buried in loose and compacted sand over a frequency range of 10-35 kHz. The application of a low impedance coating is shown to effectively decouple the influence of the sand on the ultrasound leakage from the buried pipe. We demonstrate ultrasonic isolation of a buried pipe by coating the pipe with a Polyethylene (PE)-foam layer that has a smaller impedance than both pipe and sand and the ability to withstand the overburden load from the sand. The measured attenuation in the buried PE-foam-FBE-coated pipe is substantially reduced, in the range of 0.3-1.2 dBm-1 for loose and compacted sand conditions, compared to buried FBE-coated pipe without the PE-foam, where the measured attenuation is in the range of 1.7-4.7 dBm-1. The acoustic properties of the PE-foam are measured independently using ultrasonic interferometry technique and used in model predictions of guided wave propagation in a buried coated pipe. Good agreement is found between the attenuation measurements and model predictions. The attenuation exhibits periodic peaks in the frequency domain corresponding to the through-thickness resonance frequencies of the coating layer. The large reduction in guided wave attenuation for PE-coated pipes would lead to greatly increased GWT test ranges, so such coatings would be attractive for new pipeline installations.

  6. Identification of the attenuation potential of a karst aquifer by an artificial dualtracer experiment with caffeine.

    Science.gov (United States)

    Hillebrand, Olav; Nödler, Karsten; Licha, Tobias; Sauter, Martin; Geyer, Tobias

    2012-10-15

    Little is known with respect to the attenuation capacity of karst aquifers. Even less is known about the risk posed by emerging micropollutants in these systems. In order to identify the attenuation potential of karst aquifers in-situ and to estimate the risk posed by micropollutants, a dualtracer test was conducted in this study in order to investigate differential transport in the subsurface: The reactive compound caffeine was used as a tracer to indicate the attenuation capacity within the aquifer in-situ. Due to the low limit of quantification, only small amounts of caffeine needed to be injected. To calibrate a model and to visualize the attenuation of caffeine a conservative reference tracer (uranine) is injected simultaneously. The methodology is tested in a well-characterised karst system in southwest Germany. The results indicate a significantly higher attenuation rate than was expected for karst aquifers. The attenuation is decribed as a first-order process. The corresponding half-life is 104 h. This low half-life suggests that a generally assumed low natural attenuation capacity of karst aquifers is unjustified. The observed mass loss of caffeine illustrates the potential of caffeine to be used as reactive tracer for indicating in-situ attenuation capacity within highly hydraulically conductive systems, such as karst aquifers. Due to the high attenuation rate of caffeine it does not pose a threat as a long-time contaminant. In combination with a conservative reference tracer an economical and environmentally benign method is presented in this manuscript for the in-situ determination of the attenuation capacity of highly conductive aquifer systems. PMID:22877878

  7. Variation of diffuse attenuation coefficient of downwelling irradiance in the Arctic Ocean

    Institute of Scientific and Technical Information of China (English)

    WANG Weibo; ZHAO Jinping

    2014-01-01

    The diffuse attenuation coefficient (Kd) for downwelling irradiance is calculated from solar irradiance data measured in the Arctic Ocean during 3rd and 4th Chinese National Arctic Research Expedition (CHINARE), including 18 stations and nine stations selected for irradiance profiles in sea water respectively. In this study, the variation of attenuation coefficient in the Arctic Ocean was studied, and the following results were ob-tained. First, the relationship between attenuation coefficient and chlorophyll concentration in the Arctic Ocean has the form of a power function. The best fit is at 443 nm, and its determination coefficient is more than 0.7. With increasing wavelength, the determination coefficient decreases abruptly. At 550 nm, it even reaches a value lower than 0.2. However, the exponent fitted is only half of that adapted in low-latitude ocean because of the lower chlorophyll-specific absorption in the Arctic Ocean. The upshot was that, in the case of the same chlorophyll concentration, the attenuation caused by phytoplankton chlorophyll in the Arctic Ocean is lower than in low-latitude ocean. Second, the spectral model, which exhibits the relationship of attenuation coefficients between 490 nm and other wavelength, was built and provided a new method to estimate the attenuation coefficient at other wavelength, if the attenuation coefficient at 490 nm was known. Third, the impact factors on attenuation coefficient, including sea ice and sea water mass, were discussed. The influence of sea ice on attenuation coefficient is indirect and is determined through the control of enter-ing solar radiation. The linear relationship between averaging sea ice concentration (ASIC, from 158 Julian day to observation day) and the depth of maximum chlorophyll is fitted by a simple linear equation. In addition, the sea water mass, such as the ACW (Alaskan Coastal Water), directly affects the amount of chlo-rophyll through taking more nutrient, and results in the

  8. Comprehensive study of photon attenuation through different construction matters by Monte Carlo Simulation

    Science.gov (United States)

    Medhat, M. E.

    2015-02-01

    The main goal of this work is focused on testing the applicability of Geant4 electromagnetic models for studying mass attenuations for different types of composite materials at 59.5, 80, 356, 661.6, 1173.2 and 1332.5 keV photon energies. The simulated results of mass attenuation coefficients were compared with the experimental and theoretical data for the same samples and a good agreement has been observed. The results indicate that this process can be followed to determine the data on the attenuation of gamma-rays with the several energies in different materials.

  9. Material grain size characterization method based on energy attenuation coefficient spectrum and support vector regression.

    Science.gov (United States)

    Li, Min; Zhou, Tong; Song, Yanan

    2016-07-01

    A grain size characterization method based on energy attenuation coefficient spectrum and support vector regression (SVR) is proposed. First, the spectra of the first and second back-wall echoes are cut into several frequency bands to calculate the energy attenuation coefficient spectrum. Second, the frequency band that is sensitive to grain size variation is determined. Finally, a statistical model between the energy attenuation coefficient in the sensitive frequency band and average grain size is established through SVR. Experimental verification is conducted on austenitic stainless steel. The average relative error of the predicted grain size is 5.65%, which is better than that of conventional methods.

  10. Ground motion attenuation relation for small to moderate earthquakes in Fujian region, China

    Institute of Scientific and Technical Information of China (English)

    JIN Xing; KANG Lan-chi; OU Yi-ping

    2008-01-01

    We collect 1974 broad-band velocity records of 94 earthquakes (ML=2.8-4.9, △=13~462 km) from seven stations of the Fujian Seismic Network from March 1999 to March 2007. Using real-time simulation, we obtain the corre-sponding acceleration and then adopt different models to analyze the seismic data. As a result, a new attenuation relationship between PGA and PGV of the small and moderate earthquakes on bedrock site in Fujian region is established. The Yongchun earthquake occurred recently verifies the attenuation relationship well. This paper pro-vides a new approach for studying the ground motion attenuation relationship using velocity records.

  11. Advanced reconstruction of attenuation maps using SPECT emission data only

    Science.gov (United States)

    Salomon, André; Goedicke, Andreas; Aach, Til

    2009-02-01

    Today, attenuation corrected SPECT, typically performed using CT or Gadolinium line source based transmission scans, is more and more becoming standard in many medical applications. Moreover, the information about the material density distribution provided by these scans is key for other artifact compensation approaches in advanced SPECT reconstruction. Major drawbacks of these approaches are the additional patient radiation and hardware/maintenance costs as well as the additional workflow effort, e.g. if the CT scans are not performed on a hybrid scanner. It has been investigated in the past, whether it is possible to recover this structural information solely from the SPECT scan data. However, the investigated methods often result in noticeable image artifacts due to cross-dependences between attenuation and activity distribution estimation. With the simultaneous reconstruction method presented in this paper, we aim to effectively prevent these typical cross-talk artifacts using a-priori known atlas information of a human body. At first, an initial 3D shape model is coarsely registered to the SPECT data using anatomical landmarks and each organ structure within the model is identified with its typical attenuation coefficient. During the iterative reconstruction based on a modified ML-EM scheme, the algorithm simultaneously adapts both, the local activity estimation and the 3D shape model in order to improve the overall consistency between measured and estimated sinogram data. By explicitly avoiding topology modifications resulting in a non-anatomical state, we ensure that the estimated attenuation map remains realistic. Several tests with simulated as well as real patient SPECT data were performed to test the proposed algorithm, which demonstrated reliable convergence behaviour in both cases. Comparing the achieved results with available reference data, an overall good agreement for both cold as well as hot activity regions could be observed (mean deviation: -5.98%).

  12. Effect of duct shape, Mach number, and lining construction on measured suppressor attenuation and comparison with theory

    Science.gov (United States)

    Olsen, W. A.; Krejsa, E. A.; Coats, J. W.

    1972-01-01

    Noise attenuation was measured for several types of cylindrical suppressors that use a duct lining composed of honeycomb cells covered with a perforated plate. The experimental technique used gave attenuation data that were repeatable and free of noise floors and other sources of error. The suppressor length, the effective acoustic diameter, suppressor shape and flow velocity were varied. The agreement among the attenuation data and two widely used analytical models was generally satisfactory. Changes were also made in the construction of the acoustic lining to measure their effect on attenuation. One of these produced a very broadband muffler.

  13. Attenuation layer for magnetostatic wave (MSW) absorbers

    Science.gov (United States)

    Glass, H. L.; Adkins, L. R.; Stearns, F. S.

    1984-09-01

    A new technique has been developed for the suppression of MSW end reflections which give rise to passband ripple. The basic idea is to provide a thin film of highly attenuating epitaxial material at the ends of a MSW delay line while preserving high quality YIG in the active region of the device. The GGG wafer preparation is a three step process which involves: (1) the growth of the attenuation layer, (2) the removal of this layer from the central region of the wafer and (3) the growth of high quality YIG on the remaining structure. Delay lines using the attenuation layer for end terminations have been evaluated experimentally and compared to devices utilizing other termination methods. The results indicate that the attenuation layer method produces ripple suppression characteristics which are the equal of those obtained with other termination techniques. The advantage of this new method lies in its suitability for large quantity fabrication requirements.

  14. Radiation-attenuated vaccine for lungworm disease

    International Nuclear Information System (INIS)

    The work done at the Indian Veternary Research Institute, Izatnagar, on the development of a vaccine for lungworm diseases is reported. Research work done includes: (1) studies on the epidemiology and the incidence of the lungworm infections, (ii) studies on the radiation-attenuated lungworm Dictyocaulus filaria vaccine, (iii) studies on other parasites using ionizing radiation, (iv) incidence of lungworm infection in sheep in Jammu and Kashmir State, (v) suitable dose of gamma radiation for attenuation, (vi) laboratory studies with radiation-attenuated D. filaria vaccine, (vii) serology of D. filaria infection, (viii) field trials with the radiation-attenuated vaccine, (ix) immune response of previously exposed lambs to vaccination, (x) comparative susceptibility of sheep and goats to infection with D. filaria, (xi) quantitative studies of D. filaria in lambs and (xii) production and supply of lungworm vaccine. (A.K.)

  15. Effect of grain size distribution on attenuation and backscattered grain noise

    International Nuclear Information System (INIS)

    The attenuation and backscattered grain noises in pure irons were measured. From the backscattered grain noise FOM (Figure-of-merit) which is a material dependent parameter were obtained by using independent scattering model. Attenuation coefficients and FOM's were compared with the results calculated by LPM theory and the general scattering model, respectively. Although the absolute values were not exactly same between measured and calculated results, the dependencies of them on the average grain size could be confirmed. The effect of grain size distribution on attenuation and backscattered grain noise was analyzed. The different scattering mechanisms according to the ratio of wavelength to grain size were applied to the analysis of the attenuation and backscattering even in a specimen.

  16. Mass attenuation coefficients of composite materials by Geant4, XCOM and experimental data: comparative study

    Science.gov (United States)

    Medhat, M. E.; Singh, V. P.

    2014-09-01

    The main goal of this present study is focused on testing the applicability of Geant4 electromagnetic models for studying mass attenuations coefficients for different types of composite materials at 59.5, 80, 356, 661.6, 1173.2 and 1332.5 keV photon energies. The simulated results of mass attenuation coefficients were compared with the experimental and theoretical XCOM data for the same samples and a good agreement has been observed. The results indicate that this process can be followed to determine the data on the attenuation of gamma rays with the several energies in different materials. The modeling for photon interaction parameters was standard for any type of composite samples. The Geant4 code can be utilized for gamma ray attenuation coefficients for the sample at different energies, which may sometimes be impractical by experiment investigation.

  17. Attenuation of concentration fluctuations of water vapor and other trace gases in turbulent tube flow

    DEFF Research Database (Denmark)

    Massman, W.J.; Ibrom, Andreas

    2008-01-01

    of EC-related tube attenuation effects have either not considered this issue at all or have only examined it superficially. Nonetheless, the attenuation of water vapor fluctuations is clearly much greater than might be expected from a passive tracer in turbulent tube flow. This study reexamines...... the turbulent tube flow issue for both passive and sorbing tracers with the intent of developing a physically-based semi-empirical model that describes the attenuation associated with water vapor fluctuations. Toward this end, we develop a new model of tube flow dynamics (radial profiles of the turbulent......Recent studies with closed-path eddy covariance (EC) systems have indicated that the attenuation of fluctuations of water vapor concentration is dependent upon ambient relative humidity, presumably due to sorption/desorption of water molecules at the interior surface of the tube. Previous studies...

  18. Phase Aberration and Attenuation Effects on Acoustic Radiation Force-Based Shear Wave Generation.

    Science.gov (United States)

    Carrascal, Carolina Amador; Aristizabal, Sara; Greenleaf, James F; Urban, Matthew W

    2016-02-01

    Elasticity is measured by shear wave elasticity imaging (SWEI) methods using acoustic radiation force to create the shear waves. Phase aberration and tissue attenuation can hamper the generation of shear waves for in vivo applications. In this study, the effects of phase aberration and attenuation in ultrasound focusing for creating shear waves were explored. This includes the effects of phase shifts and amplitude attenuation on shear wave characteristics such as shear wave amplitude, shear wave speed, shear wave center frequency, and bandwidth. Two samples of swine belly tissue were used to create phase aberration and attenuation experimentally. To explore the phase aberration and attenuation effects individually, tissue experiments were complemented with ultrasound beam simulations using fast object-oriented C++ ultrasound simulator (FOCUS) and shear wave simulations using finite-element-model (FEM) analysis. The ultrasound frequency used to generate shear waves was varied from 3.0 to 4.5 MHz. Results: The measured acoustic pressure and resulting shear wave amplitude decreased approximately 40%-90% with the introduction of the tissue samples. Acoustic intensity and shear wave displacement were correlated for both tissue samples, and the resulting Pearson's correlation coefficients were 0.99 and 0.97. Analysis of shear wave generation with tissue samples (phase aberration and attenuation case), measured phase screen, (only phase aberration case), and FOCUS/FEM model (only attenuation case) showed that tissue attenuation affected the shear wave generation more than tissue aberration. Decreasing the ultrasound frequency helped maintain a focused beam for creation of shear waves in the presence of both phase aberration and attenuation.

  19. Extended Safety and Efficacy Studies of the Attenuated Brucella Vaccine Candidates 16MΔvjbR and S19ΔvjbR in the Immunocompromised IRF-1−/− Mouse Model

    OpenAIRE

    Arenas-Gamboa, A. M.; Rice-Ficht, A C; Fan, Y.; Kahl-McDonagh, M. M.; Ficht, T A

    2012-01-01

    The global distribution of brucellosis and high incidence in certain areas of the world warrant the development of a safer and efficacious vaccine. For the past 10 years, we have focused our attention on the development of a safer, but still highly protective, live attenuated vaccine for human and animal use. We have demonstrated the safety and protective efficacy of the vaccine candidates 16MΔvjbR and S19ΔvjbR against homologous and heterologous challenge in multiple immunocompetent animal m...

  20. Backscatter and attenuation characterization of ventricular myocardium

    Science.gov (United States)

    Gibson, Allyson Ann

    2009-12-01

    This Dissertation presents quantitative ultrasonic measurements of the myocardium in fetal hearts and adult human hearts with the goal of studying the physics of sound waves incident upon anisotropic and inhomogeneous materials. Ultrasound has been used as a clinical tool to assess heart structure and function for several decades. The clinical usefulness of this noninvasive approach has grown with our understanding of the physical mechanisms underlying the interaction of ultrasonic waves with the myocardium. In this Dissertation, integrated backscatter and attenuation analyses were performed on midgestational fetal hearts to assess potential differences in the left and right ventricular myocardium. The hearts were interrogated using a 50 MHz transducer that enabled finer spatial resolution than could be achieved at more typical clinical frequencies. Ultrasonic data analyses demonstrated different patterns and relative levels of backscatter and attenuation from the myocardium of the left ventricle and the right ventricle. Ultrasonic data of adult human hearts were acquired with a clinical imaging system and quantified by their magnitude and time delay of cyclic variation of myocardial backscatter. The results were analyzing using Bayes Classification and ROC analysis to quantify potential advantages of using a combination of two features of cyclic variation of myocardial backscatter over using only one or the other feature to distinguish between groups of subjects. When the subjects were classified based on hemoglobin A1c, the homeostasis model assessment of insulin resistance, and the ratio of triglyceride to high-density lipoprotein-cholesterol, differences in the magnitude and normalized time delay of cyclic variation of myocardial backscatter were observed. The cyclic variation results also suggested a trend toward a larger area under the ROC curve when information from magnitude and time delay of cyclic variation is combined using Bayes classification than when

  1. Photochemical Attenuation of Pesticides in Prairie Potholes

    Science.gov (United States)

    Zeng, T.; Arnold, W. A.

    2013-12-01

    DOM appeared to exert the largest effects on the overall photodegradation. Furthermore, a suite of second-order rate constants for reactions of pesticides with PPRIs were derived based on the quenching effect on observed reaction rate constants and measured steady-state concentrations of PPRIs. These rate constants may find practical utility for estimating DOM photochemical reaction rates in addition to data traditionally estimated from model compounds. Overall, our work contributed to a systematic evaluation of the potential for photochemical attenuation of pesticides in near-surface pothole water. Given recent incentives to expand agriculture in the PPR for production of organic crops and corn-based biofuels, this research also calls for the need to properly conserve prairie potholes and to develop regionally-specific, sustainable water resource management and land use strategies.

  2. Silibinin attenuates allergic airway inflammation in mice

    International Nuclear Information System (INIS)

    Highlights: ► Silibinin diminishes ovalbumin-induced inflammatory reactions in the mouse lung. ► Silibinin reduces the levels of various cytokines into the lung of allergic mice. ► Silibinin prevents the development of airway hyperresponsiveness in allergic mice. ► Silibinin suppresses NF-κB transcriptional activity. -- Abstract: Allergic asthma is a chronic inflammatory disease regulated by coordination of T-helper2 (Th2) type cytokines and inflammatory signal molecules. Silibinin is one of the main flavonoids produced by milk thistle, which is reported to inhibit the inflammatory response by suppressing the nuclear factor-kappa B (NF-κB) pathway. Because NF-κB activation plays a pivotal role in the pathogenesis of allergic inflammation, we have investigated the effect of silibinin on a mouse ovalbumin (OVA)-induced asthma model. Airway hyperresponsiveness, cytokines levels, and eosinophilic infiltration were analyzed in bronchoalveolar lavage fluid and lung tissue. Pretreatment of silibinin significantly inhibited airway inflammatory cell recruitment and peribronchiolar inflammation and reduced the production of various cytokines in bronchoalveolar fluid. In addition, silibinin prevented the development of airway hyperresponsiveness and attenuated the OVA challenge-induced NF-κB activation. These findings indicate that silibinin protects against OVA-induced airway inflammation, at least in part via downregulation of NF-κB activity. Our data support the utility of silibinin as a potential medicine for the treatment of asthma.

  3. Silibinin attenuates allergic airway inflammation in mice

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yun Ho [Department of Anatomy, Medical School, Institute for Medical Sciences, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Jin, Guang Yu [Department of Radiology, Yanbian University Hospital, YanJi 133002 (China); Guo, Hui Shu [Centralab, The First Affiliated Hospital of Dalian Medical University, Dalian 116011 (China); Piao, Hong Mei [Department of Respiratory Medicine, Yanbian University Hospital, YanJi 133000 (China); Li, Liang chang; Li, Guang Zhao [Department of Anatomy and Histology and Embryology, Yanbian University School of Basic Medical Sciences, 977 Gongyuan Road, YanJi 133002, Jilin (China); Lin, Zhen Hua [Department of Pathology, Yanbian University School of Basic Medical Sciences, YanJi 133000 (China); Yan, Guang Hai, E-mail: ghyan@ybu.edu.cn [Department of Anatomy and Histology and Embryology, Yanbian University School of Basic Medical Sciences, 977 Gongyuan Road, YanJi 133002, Jilin (China)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer Silibinin diminishes ovalbumin-induced inflammatory reactions in the mouse lung. Black-Right-Pointing-Pointer Silibinin reduces the levels of various cytokines into the lung of allergic mice. Black-Right-Pointing-Pointer Silibinin prevents the development of airway hyperresponsiveness in allergic mice. Black-Right-Pointing-Pointer Silibinin suppresses NF-{kappa}B transcriptional activity. -- Abstract: Allergic asthma is a chronic inflammatory disease regulated by coordination of T-helper2 (Th2) type cytokines and inflammatory signal molecules. Silibinin is one of the main flavonoids produced by milk thistle, which is reported to inhibit the inflammatory response by suppressing the nuclear factor-kappa B (NF-{kappa}B) pathway. Because NF-{kappa}B activation plays a pivotal role in the pathogenesis of allergic inflammation, we have investigated the effect of silibinin on a mouse ovalbumin (OVA)-induced asthma model. Airway hyperresponsiveness, cytokines levels, and eosinophilic infiltration were analyzed in bronchoalveolar lavage fluid and lung tissue. Pretreatment of silibinin significantly inhibited airway inflammatory cell recruitment and peribronchiolar inflammation and reduced the production of various cytokines in bronchoalveolar fluid. In addition, silibinin prevented the development of airway hyperresponsiveness and attenuated the OVA challenge-induced NF-{kappa}B activation. These findings indicate that silibinin protects against OVA-induced airway inflammation, at least in part via downregulation of NF-{kappa}B activity. Our data support the utility of silibinin as a potential medicine for the treatment of asthma.

  4. Statins attenuate polymethylmethacrylate-mediated monocyte activation.

    LENUS (Irish Health Repository)

    Laing, Alan J

    2012-02-03

    BACKGROUND: Periprosthetic osteolysis precipitates aseptic loosening of components, increases the risk of periprosthetic fracture and, through massive bone loss, complicates revision surgery and ultimately is the primary cause for failure of joint arthroplasty. The anti-inflammatory properties of HMG-CoA reductase inhibitors belonging to the statin family are well recognized. We investigated a possible role for status in initiating the first stage of the osteolytic cycle, namely monocytic activation. METHODS: We used an in vitro model of the human monocyte\\/macrophage inflammatory response to poly-methylmethacrylate (PMMA) particles after pretreat-ing cells with cerivastatin, a potent member of the statin family. Cell activation based upon production of TNF-alpha and MCP-1 cytokines was analyzed and the intracellular Raf-MEK-ERK signal transduction pathway was evaluated using western blot analysis, to identify its role in cell activation and in any cerivastatin effects observed. RESULTS: We found that pretreatment with cerivastatin significantly abrogates the production of inflammatory cytokines TNF-alpha and MCP-1 by human monocytes in response to polymethylmethacrylate particle activation. This inflammatory activation and attenuation appear to be mediated through the intracellular Raf-MEK-ERK pathway. INTERPRETATION: We propose that by intervening at the upstream activation stage, subsequent osteoclast activation and osteolysis can be suppressed. We believe that the anti-inflammatory properties of statins may potentially play a prophylactic role in the setting of aseptic loosening, and in so doing increase implant longevity.

  5. Electron Effective-Attenuation-Length Database

    Science.gov (United States)

    SRD 82 NIST Electron Effective-Attenuation-Length Database (PC database, no charge)   This database provides values of electron effective attenuation lengths (EALs) in solid elements and compounds at selected electron energies between 50 eV and 2,000 eV. The database was designed mainly to provide EALs (to account for effects of elastic-eletron scattering) for applications in surface analysis by Auger-electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS).

  6. Simulating atmospheric free-space optical propagation: rainfall attenuation

    Science.gov (United States)

    Achour, Maha

    2002-04-01

    With recent advances and interest in Free-Space Optics (FSO) for commercial deployments, more attention has been placed on FSO weather effects and the availability of global weather databases. The Meteorological Visual Range (Visibility) is considered one of the main weather parameters necessary to estimate FSO attenuation due to haze, fog and low clouds. Proper understanding of visibility measurements conducted throughout the years is essential. Unfortunately, such information is missing from most of the databases, leaving FSO players no choice but to use the standard visibility equation based on 2% contrast and other assumptions on the source luminance and its background. Another challenge is that visibility is measured using the visual wavelength of 550 nm. Extrapolating the measured attenuations to longer infrared wavelengths is not trivial and involves extensive experimentations. Scattering of electromagnetic waves by spherical droplets of different sizes is considered to simulate FSO scattering effects. This paper serves as an introduction to a series of publications regarding simulation of FSO atmospheric propagation. This first part focuses on attenuation due to rainfall. Additional weather parameters, such as rainfall rate, temperature and relative humidity are considered to effectively build the rain model. Comparison with already published experimental measurement is performed to validate the model. The scattering cross section due to rain is derived from the density of different raindrop sizes and the raindrops fall velocity is derived from the overall rainfall rate. Absorption due the presence of water vapor is computed using the temperature and relative humidity measurements.

  7. Experimental and theoretical studies on visible light attenuation in water

    CERN Document Server

    Simpson, A; Cho, H J; Liu, H

    2014-01-01

    In this study we describe lab experiments on determining the above water reflectance Rrs coefficient, and the water attenuation coefficient Kd for fresh water. Different types of screens (totally absorbent, gray, etc.) were submerged in water (0-0.6 m) and illuminated from outside. The spectral density of the water leaving radiance was measured for different depths. The results were ran by a code which took into account the geometry of the incident irradiation, the geometry of the screen under water, and boundary conditions at the water surface provided by the radiation transfer theory. From the experimental data and our model we obtain the spectral distribution of the attenuation coefficient for fresh water and compared it with other data in literature. These experiments, performed in the Nonlinear Wave Lab at ERAU# represent just a preliminary calibration of the experimental protocol. More tests with water of different degrees of turbidity, and possibly wave filed at the water surface are in progress and wi...

  8. Electroacupuncture attenuates neuropathic pain after brachial plexus injury

    Institute of Scientific and Technical Information of China (English)

    Shenyu Zhang; Hailiang Tang; Junming Zhou; Yudong Gu

    2014-01-01

    Electroacupuncture has traditionally been used to treat pain, but its effect on pain following brachial plexus injury is still unknown. In this study, rat models of an avulsion injury to the left brachial plexus root (associated with upper-limb chronic neuropathic pain) were given electroacu-puncture stimulation at bilateralQuchi(LI11),Hegu(LI04),Zusanli(ST36) andYanglingquan (GB34). After electroacupuncture therapy, chronic neuropathic pain in the rats’ upper limbs was signiifcantly attenuated. Immunolfuorescence staining showed that the expression of β-endorphins in the arcuate nucleus was signiifcantly increased after therapy. Thus, experimental ifndings indi-cate that electroacupuncture can attenuate neuropathic pain after brachial plexus injury through upregulatingβ-endorphin expression.

  9. Design and Simulation of Microwave Attenuators for Superconducting Quantum Devices

    Science.gov (United States)

    Lefebvre, Jay; Yeh, Jen-Hao; Wellstood, Frederick; Palmer, Benjamin

    We have found that dephasing times for quantum superconducting transmons operating nominally at T = 20 mK can be limited by thermal photons in the read-out cavity due to non-equilibrium noise on our input microwave line. In an effort to reduce this noise, we have used finite-element simulations to design attenuators that provide better thermalization of the input microwave signals being delivered to our devices. Our thermal simulations incorporate both electron-phonon decoupling effects due to dissipated power in each element of the attenuator as well as phonon thermal conduction and Kapitza boundary effects. We combine the resulting thermal map with a thermal noise model of each dissipative element of the filter to estimate the effective noise temperature of our filter design.

  10. Received Power Attenuation Analysis Based on Wavelet for Reflection-Style Optical Antenna Deformations in Free-Space Laser Communications

    OpenAIRE

    Wanqing Xie; Liying Tan; Jing Ma; Yang Liu

    2011-01-01

    Diversified deformations on reflection-style optical antennas caused by processing technique and complex outer-space environment in free-space laser communications are modeled by wavelet analysis. Influence due to the deformations on received power is studied by distortion attenuation factor based on the model. Theoretical and numerical analysis shows that distortion attenuation factor increases with shift factor of the model, decreases with dilation factor of the model, and decreases with ir...

  11. Novel Vaccine against Venezuelan Equine Encephalitis Combines Advantages of DNA Immunization and a Live Attenuated Vaccine

    OpenAIRE

    Tretyakova, Irina; Lukashevich, Igor S; Glass, Pamela; Wang, Eryu; Weaver, Scott; Pushko, Peter

    2012-01-01

    DNA vaccines combine remarkable genetic and chemical stability with proven safety and efficacy in animal models, while remaining less immunogenic in humans. In contrast, live-attenuated vaccines have the advantage of inducing rapid, robust, long-term immunity after a single-dose vaccination. Here we describe novel iDNA vaccine technology that is based on an infectious DNA platform and combines advantages of DNA and live attenuated vaccines. We applied this technology for vaccination against i...

  12. In-Situ Measurement of Relative Attenuation Length of Gadolinium-Loaded Liquid Scintillator Using Source Data at RENO Experiment

    CERN Document Server

    Kim, H S; Choi, J H; Choi, W Q; Choi, Y; Jang, H I; Jang, J S; Joo, K K; Kim, B R; Kim, J Y; Kim, S B; Kim, W; Kwon, E; Lee, D H; Lim, I T; Pac, M Y; Park, I G; Park, J S; Park, R G; Seo, H; Seo, S H; Seon, Y G; Shin, C D; Yeo, I S; Yu, I

    2016-01-01

    We present an in-situ method of measuring the relative attenuation length of gadolinium-loaded liquid scintillator in the RENO detectors using radioactive source calibration data without requiring any PMT performance model. We observed the degradation of the attenuation length of the gadolinium-loaded liquid scintillator in the RENO detectors by ~50% over a period of about 4 years.

  13. Optimal Acoustic Attenuation of Weakly Compressible Media Permeated with Air Bubbles

    Institute of Scientific and Technical Information of China (English)

    LIANG Bin; CHENG Jian-Chun

    2007-01-01

    Based on fuzzy logic (FL) and genetic algorithm (GA), we present an optimization method to obtain the optimal acoustic attenuation of a longitudinal acoustic wave propagating in a weakly compressible medium permeated with air bubbles. In the optimization, the parameters of the size distribution of bubbles in the medium are optimized for providing uniformly high acoustic attenuation in the frequency band of interest. Compared with other traditional optimization methods, the unique advantage of the present method is that it can locate the global optimum quickly and effectively in need of knowing the mathematical model precisely. As illustrated by a numerical simulation, the method is effective and essential in enhancing the acoustic attenuation of such a medium in an optimal manner. The bubbly medium with optimized structural parameters can effectively attenuate longitudinal waves at intermediate frequencies with an acoustic attenuation approximating a constant value of 10(dB/cm). Such bubbly media with optimal acoustic attenuations may be applied to design acoustic absorbent by controlling broader attenuation band and higher efficiency.

  14. Attenuation compensation for least-squares reverse time migration using the viscoacoustic-wave equation

    KAUST Repository

    Dutta, Gaurav

    2014-10-01

    Strong subsurface attenuation leads to distortion of amplitudes and phases of seismic waves propagating inside the earth. Conventional acoustic reverse time migration (RTM) and least-squares reverse time migration (LSRTM) do not account for this distortion, which can lead to defocusing of migration images in highly attenuative geologic environments. To correct for this distortion, we used a linearized inversion method, denoted as Qp-LSRTM. During the leastsquares iterations, we used a linearized viscoacoustic modeling operator for forward modeling. The adjoint equations were derived using the adjoint-state method for back propagating the residual wavefields. The merit of this approach compared with conventional RTM and LSRTM was that Qp-LSRTM compensated for the amplitude loss due to attenuation and could produce images with better balanced amplitudes and more resolution below highly attenuative layers. Numerical tests on synthetic and field data illustrated the advantages of Qp-LSRTM over RTM and LSRTM when the recorded data had strong attenuation effects. Similar to standard LSRTM, the sensitivity tests for background velocity and Qp errors revealed that the liability of this method is the requirement for smooth and accurate migration velocity and attenuation models.

  15. Acetate supplementation attenuates lipopolysaccharide-induced neuroinflammation.

    Science.gov (United States)

    Reisenauer, Chris J; Bhatt, Dhaval P; Mitteness, Dane J; Slanczka, Evan R; Gienger, Heidi M; Watt, John A; Rosenberger, Thad A

    2011-04-01

    Glyceryl triacetate (GTA), a compound effective at increasing circulating and tissue levels of acetate was used to treat rats subjected to a continual 28 day intra-ventricular infusion of bacterial lipopolysaccharide (LPS). This model produces a neuroinflammatory injury characterized by global neuroglial activation and a decrease in choline acetyltransferase immunoreactivity in the basal forebrain. During the LPS infusion, rats were given a daily treatment of either water or GTA at a dose of 6 g/kg by oral gavage. In parallel experiments, free-CoA and acetyl-CoA levels were measured in microwave fixed brains and flash frozen heart, liver, kidney and muscle following a single oral dose of GTA. We found that a single oral dose of GTA significantly increased plasma acetate levels by 15 min and remained elevated for up to 4 h. At 30 min the acetyl-CoA levels in microwave-fixed brain and flash frozen heart and liver were increased at least 2.2-fold. The concentrations of brain acetyl-CoA was significantly increased between 30 and 45 min following treatment and remained elevated for up to 4 h. The concentration of free-CoA in brain was significantly decreased compared to controls at 240 min. Immunohistochemical and morphological analysis demonstrated that a daily treatment with GTA significantly reduced the percentage of reactive glial fibrillary acidic protein-positive astrocytes and activated CD11b-positive microglia by 40-50% in rats subjected to LPS-induced neuroinflammation. Further, in rats subjected to neuroinflammation, GTA significantly increased the number of choline acetyltransferase (ChAT)-positive cells by 40% in the basal forebrain compared to untreated controls. These data suggest that acetate supplementation increases intermediary short chain acetyl-CoA metabolism and that treatment is potentially anti-inflammatory and neuroprotective with regards to attenuating neuroglial activation and increasing ChAT immunoreactivity in this model. PMID:21272004

  16. Predicting spectral and PAR light attenuation in Greenlandic coastal waters

    DEFF Research Database (Denmark)

    Murray, Ciarán; Markager, Stiig; Stedmon, Colin

    present models for spectral and PAR (photosynthetically active radiation) attenuation in two contrasting Greenlandic fjords, Godthåbsfjord (SW Greenland) and Young Sound (NE Greenland). The fjords differ in the character and concentrations of optically active components present: dissolved organic material...... (CDOM), phytoplankton pigments and inorganic particles. These differences are due in part to hydrography and to the sources of meltwater: respectively, fjord-terminating and land-terminating glaciers. We present a model to explain the variation in spectral and PAR irradiance in terms of the variation...

  17. Predicting Spectral and PAR Light Attenuation in Greenlandic Coastal Waters

    DEFF Research Database (Denmark)

    Murray, Ciarán; Stedmon, Colin A.; Markager, Stiig

    present models for spectral and PAR (photosynthetically active radiation) attenuation in two contrasting Greenlandic fjords, Godthåbsfjord (SW Greenland) and Young Sound (NE Greenland). The fjords differ in the character and concentrations of optically active components present: dissolved organic material...... (CDOM), phytoplankton pigments and inorganic particles. These differences are due in part to hydrography and to the sources of meltwater: respectively, fjord-terminating and land-terminating glaciers. We present a model to explain the variation in spectral and PAR irradiance in terms of the variation...

  18. Seismic attenuation due to wave-induced flow

    Energy Technology Data Exchange (ETDEWEB)

    Pride, S.R.; Berryman, J.G.; Harris, J.M.

    2003-10-09

    Analytical expressions for three P-wave attenuation mechanisms in sedimentary rocks are given a unified theoretical framework. Two of the models concern wave-induced flow due to heterogeneity in the elastic moduli at mesoscopic scales (scales greater than grain sizes but smaller than wavelengths). In the first model, the heterogeneity is due to lithological variations (e.g., mixtures of sands and clays) with a single fluid saturating all the pores. In the second model, a single uniform lithology is saturated in mesoscopic ''patches'' by two immiscible fluids (e.g., air and water). In the third model, the heterogeneity is at ''microscopic'' grain scales (broken grain contacts and/or micro-cracks in the grains) and the associated fluid response corresponds to ''squirt flow''. The model of squirt flow derived here reduces to proper limits as any of the fluid bulk modulus, crack porosity, and/or frequency is reduced to zero. It is shown that squirt flow is incapable of explaining the measured level of loss (10{sup -2} < Q{sup -1} < 10{sup -1}) within the seismic band of frequencies (1 to 10{sup 4} Hz); however, either of the two mesoscopic scale models easily produce enough attenuation to explain the field data.

  19. The attenuate hyperalgesia effect of intrathecal U0126 in a rat model of bone cancer pain%骨癌痛大鼠鞘内注射U0126的抗痛觉过敏作用

    Institute of Scientific and Technical Information of China (English)

    李彩芳; 杨建平; 王丽娜; 刘磊; 胡计嬅; 刘思兰

    2011-01-01

    目的 研究鞘内注射(it)U0126对骨癌痛大鼠机械痛敏的影响和对脊髓背角磷酸化cAMP反应元件结合蛋白(pCREB)表达的影响,探讨ERK-CREB信号转导通路在骨癌痛中的作用.方法 ① 40只成年♀SD大鼠分为5组,假模型组Ⅰ和骨癌痛模型组Ⅱ、Ⅲ、Ⅳ、Ⅴ.建模后d 10每只大鼠分别it 10 μg U0126、5%二甲亚砜10 μl和U0126 0.1、1、10 μg(U0126溶于10 μl 5%二甲亚砜中),测机械性缩爪阈值(MWT)和双下肢负重差(WBD);② 25只成年♀SD大鼠分为5组,T1、T2和T3组在制作骨癌痛模型后d 10,it U0126 10 μg后1、6、24 h处死大鼠,M组为模型对照组,it 5%二甲亚砜10 μl后6 h处死大鼠,S组为空白对照组.免疫组化方法测定L4-6术侧脊髓背角pCREB免疫反应阳性神经元数量.结果 鞘内注射U0126 1 μg和10 μg明显逆转了骨癌痛引起的机械痛敏;鞘内注射10 μg U0126明显减少脊髓背角pCREB表达,且效果至少可持续6 h.结论 ERK-CREB通路可能参与骨癌痛.%Aim To investigate the effect of intrathecal ( i. t. ) U0126( MAPK kinase inhibitor ) on the mechanical hyperalgesia and the expression of phosphorylated cAMP response element binding protein( pCREB ) in the dorsal horn of spinal cord following bone cancer pain in rats , trying to evaluate the role played by ERKCREB signal transmission pathway in the mechanism of bone cancer pain. Methods ① 40 adult female SD rats were divided into five groups. Sham group Ⅰ and bone cancer pain ( BCP ) group rats Ⅱ . Ⅲ , Ⅳ , Ⅴ received a bolus of 10 μg U0126. 5% DMSO 10 μl,U0126 0. 1, 1, 10 μg i. t. respectively on the 10th day after the model was made. Mechanical withdrawal threshold ( MWT ) and weight bearing difference ( WBD ) were measured;②25 adult female SD rats were divided into five groups. On the lOth day after the model was made, BCP rats of group T1 , T2 and T3 were killed at 1, 6. 24 h after i. t. U0126 10 μg respectively. In group M, rats produced bone

  20. Stacking coda waves to resolve the scattering and attenuation structure of Southern California

    Science.gov (United States)

    Wang, W.; Shearer, P. M.

    2015-12-01

    Seismic attenuation is caused by two factors, scattering and intrinsic absorption. Charactering the scattering and attenuation properties and the power spectrum of crustal heterogeneity is a fundamental problem for informing strong ground motion estimates at high frequencies, where scattering and attenuation effects are critical. Determining the relative amount of attenuation caused by scattering and intrinsic absorption has been a long-standing interest of seismologists. The wavetrain following the direct body-wave phases is called the coda and is caused by scattered energy. Many studies have analyzed local-event coda to infer crustal and upper-mantle scattering strength and intrinsic attenuation. Here we describe a comprehensive study of coda behavior in Southern California to resolve scattering and intrinsic attenuation structure. First, we apply an envelope-function stacking method to 287,410 seismograms from 6928 geographically dispersed events of M ≥ 1.8 from 1981-2005. The results are presented as spatial averages as a function of distance, source depth, and frequency. Second, we use a Monte Carlo seismic phonon algorithm to simulate the effects of depth-dependent scattering and intrinsic attenuation, which computes scattering probabilities and scattering angles based on theoretical results for random heterogeneity models. This method has the advantage of including both P- and S-wave scattering and is energy conserving even for multiple scattering models. The input 1-D velocity model can be layered to incorporate reflected phases, such as PmP and SmS, to better fit the observations. We will summarize our results for the average scattering and attenuation properties of the southern California crust and the implications for strong ground motion predictions.

  1. Aspects of flow attenuation performance of retention ponds

    Science.gov (United States)

    Wallis, S. G.; Morgan, C. T.; Heal, K.

    2003-04-01

    The work reported here is part of a wider modelling study into the performance of sustainable urban drainage systems (SUDS) in Scotland. Developments that increase the urbanisation of catchments are now required by the Scottish Environment Protection Agency to include SUDS to protect receiving watercourses from flooding and water quality deterioration. Here we report specifically on some initial simulations of storm water retention ponds. These are normally wet storage facilities that provide both flow attenuation and water quality treatment (from settlement of suspended solids and biological treatment of some pollutants). Here we focus on the flow attenuation characteristics. A sensitivity analysis was performed on a model of a cylindrical pond with outflow through a V-notch weir. The aim of the simulations was to help us to learn about the flow attenuation characteristics of retention ponds, so that later work could be properly focused on the key issues. In addition the flow simulation model underpins later models of water quality and sedimentation, so it was important to ensure that its simulations were realistic. The inflows were constructed using an isosceles triangular inflow hydrograph with a peak flow of 50 l/s, a storm duration of 3.2 hours and a total inflow volume of 288 l. Values of four pond parameters were varied to test model sensitivity: radius, weir angle, weir crest elevation and initial water level. Sensitivity was investigated by observing the changes in several flow attenuation performance indicators. These were total outflow volume, peak outflow and the following three time delays: peak time delay (lag between peaks of outflow and inflow hydrographs), centroid time delay (lag between centroids of outflow and inflow hydrographs) and initial time delay (lag between the initial rise of the outflow and inflow hydrographs). Simulations were carried out using a simple Euler discretisation of the storage routing equation. A time step of 1.5 minutes

  2. THE SCENARIOS APPROACH TO ATTENUATION-BASED REMEDIES FOR INORGANIC AND RADIONUCLIDE CONTAMINANTS

    Energy Technology Data Exchange (ETDEWEB)

    Vangelas, K.; Rysz, M.; Truex, M.; Brady, P.; Newell, C.; Denham, M.

    2011-08-04

    Guidance materials based on use of conceptual model scenarios were developed to assist evaluation and implementation of attenuation-based remedies for groundwater and vadose zones contaminated with inorganic and radionuclide contaminants. The Scenarios approach is intended to complement the comprehensive information provided in the US EPA's Technical Protocol for Monitored Natural Attenuation (MNA) of Inorganic Contaminants by providing additional information on site conceptual models and extending the evaluation to consideration of Enhanced Attenuation approaches. The conceptual models incorporate the notion of reactive facies, defined as units with hydrogeochemical properties that are different from surrounding units and that react with contaminants in distinct ways. The conceptual models also incorporate consideration of biogeochemical gradients, defined as boundaries between different geochemical conditions that have been induced by waste disposal or other natural phenomena. Gradients can change over time when geochemical conditions from one area migrate into another, potentially affecting contaminant mobility. A recognition of gradients allows the attenuation-affecting conditions of a site to be projected into the future. The Scenarios approach provides a stepwise process to identify an appropriate category of conceptual model and refine it for a specific site. Scenario materials provide links to pertinent sections in the EPA technical protocol and present information about contaminant mobility and important controlling mechanism for attenuation-based remedies based on the categories of conceptual models.

  3. Ground Attenuation of Railroad Noise

    DEFF Research Database (Denmark)

    Makarewicz, R.; Rasmussen, Karsten Bo; Kokowski, P.

    1996-01-01

    The influence of ground effect on railroad noise is described using the concept of the peak A-weighted sound exposure level, and A-weighted sound exposure level. The train is modelled by a continuous line of incoherent point sources that have a cosine directivity. The ground effect is included...... by the Weyl van der Pol solution with the single parameter model of the ground impedance. The method of determining of the referenced A-weighted power spectrum is presented....

  4. Attenuation Tomography of Sierra Negra Volcano of the Galapagos Archipelago

    Science.gov (United States)

    Rodd, R.; Lees, J. M.

    2014-12-01

    Following relocation of events with the double-difference location algorithm (HypoDD), we apply tomographic methods to extract 3D attenuation models illuminating the plumbing system of the Sierra Negra Caldera of the Galapagos Archipelago. The dataset consists of 1737 events recorded from July 2009 to June 2011 on the 17-station SIGNET broadband seismic array. We use t* spectral decay methods for both P- and S- phases with the clustered locations to highlight locations where significant variations in Q suggest the presence of magma melt. While the presence of a magma sill, at least 2 km depth, is indicated by InSAR and GPS studies, the delineated magma body has not been explored in detail. The lower bound of the proposed magma accumulation is still under question and thus forms the primary target of this research. Melt replenishment and degassing of the magma sill is believed to cause inflation and/or deflation of the caldera floor. Imaging the extent of the magma sill will provide insight into the feeder system and deformation process of the Sierra Negra caldera. Detailed relocation, Qp and Qs inversion, as well as estimates of the scattering attenuation using coda-normalization technique will be presented. The close relationship between seismic attenuation and the thermal state of the magmatic system suggests we can distinguish melt and/or fluid regions within the Sierra Negra plumbing system.

  5. Comparison of non-attenuation corrected and attenuation corrected myocardial perfusion SPE

    Directory of Open Access Journals (Sweden)

    Hasan Raza

    2016-09-01

    Conclusion: This study demonstrates that CT based attenuation corrected Tc-99mm sestamibi SPECT myocardial perfusion imaging significantly improved the specificity of the RCA territory compared with non-attenuation corrected Tc-99mm sestamibi SPECT myocardial perfusion imaging in both genders irrespective of BMI.

  6. Relationship between comfort and attenuation measurements for two types of earplugs

    Directory of Open Access Journals (Sweden)

    David C Byrne

    2011-01-01

    Full Text Available Noise-induced hearing loss is almost always preventable if properly fitted hearing protectors are worn to reduce exposure. Many individuals choose not to wear hearing protection because it may interfere with effective communication in the workplace or it may be uncomfortable. Hearing protector comfort has not received the same amount of attention as noise reduction capability. The present study was conducted to evaluate the comfort level of two different types of insert earplugs as well as the attenuation levels achieved by the earplugs. Attenuation levels were obtained with a commercially available earplug fit-test system, and the comfort ratings were obtained by questionnaire. The primary research objective was to determine whether hearing protector comfort was related to measured attenuation values. A linear mixed effects model provided evidence for an inverse relationship between comfort and attenuation.

  7. Measuring soil sydric content by the attenuation of a microwave signal

    International Nuclear Information System (INIS)

    Measuring soil water content by means of microwave signal attenuation. The attenuation of microwave signal was used to measure the moisture of various soils. Samples of three soils with different textures and organic matter contents were used. The attenuation of the transmitted electromagnetic signal was measured for each sample with different values of soil moisture. Linear regression models were used to fit the experimental values obtained, and the 95% prediction interval was estimated for the attenuation. From the comparison between the moisture values obtained with this method and those of the gravimetric method, the advantages of the first one are seen, both in speed and in the possibility to estimate the in situ moisture, even if this method has a greater relative error. This method would be useful to operate an automatic control irrigation system, preventing hydric stress when the values of soil moisture reach near field capacity. (author)

  8. Research on High Frequency Amplitude Attenuation of Electric Fast Transient Generator

    Directory of Open Access Journals (Sweden)

    Huafu Zhang

    2013-01-01

    Full Text Available In order to solve the amplitude attenuation of electric fast transient (EFT generator operating in high frequency, the charging and discharging process of energy storage capacitor in EFT generator are analyzed, the main circuit voltage variation mathematical model is established, the parameters of main loop circuit and the parameters of switch driving waveform which affect burst amplitude are discussed. Through the simulation, this paper puts forward effective methods to overcome burst amplitude attenuation in high frequency. The simulation results show that when the frequency is low, the duty ratio of drive signal have little effect on energy storage capacitor voltage amplitude attenuation. when the charging resistance is less than 500 Ω, the duty ratio of drive signal is less than 0.125, the repetition frequency of burst reaches 1.2 MHz, the amplitude attenuation of energy storage capacitor voltage is less than 9%, the amplitude of burst satisfies IEC61000-4-4 standards.

  9. Arsenic cycling in hydrocarbon plumes: secondary effects of natural attenuation

    Science.gov (United States)

    Cozzarelli, Isabelle M.; Schreiber, Madeline E.; Erickson, Melinda L.; Ziegler, Brady A.

    2016-01-01

    Monitored natural attenuation is widely applied as a remediation strategy at hydrocarbon spill sites. Natural attenuation relies on biodegradation of hydrocarbons coupled with reduction of electron acceptors, including solid phase ferric iron (Fe(III)). Because arsenic (As) adsorbs to Fe-hydroxides, a potential secondary effect of natural attenuation of hydrocarbons coupled with Fe(III) reduction is a release of naturally occurring As to groundwater. At a crude-oil-contaminated aquifer near Bemidji, Minnesota, anaerobic biodegradation of hydrocarbons coupled to Fe(III) reduction has been well documented. We collected groundwater samples at the site annually from 2009 to 2013 to examine if As is released to groundwater and, if so, to document relationships between As and Fe inside and outside of the dissolved hydrocarbon plume. Arsenic concentrations in groundwater in the plume reached 230 µg/L, whereas groundwater outside the plume contained less than 5 µg/L As. Combined with previous data from the Bemidji site, our results suggest that (1) naturally occurring As is associated with Fe-hydroxides present in the glacially derived aquifer sediments; (2) introduction of hydrocarbons results in reduction of Fe-hydroxides, releasing As and Fe to groundwater; (3) at the leading edge of the plume, As and Fe are removed from groundwater and retained on sediments; and (4) downgradient from the plume, patterns of As and Fe in groundwater are similar to background. We develop a conceptual model of secondary As release due to natural attenuation of hydrocarbons that can be applied to other sites where an influx of biodegradable organic carbon promotes Fe(III) reduction.

  10. Arctigenin, a Potent Ingredient of Arctium lappa L., Induces Endothelial Nitric Oxide Synthase and Attenuates Subarachnoid Hemorrhage-Induced Vasospasm through PI3K/Akt Pathway in a Rat Model.

    Science.gov (United States)

    Chang, Chih-Zen; Wu, Shu-Chuan; Chang, Chia-Mao; Lin, Chih-Lung; Kwan, Aij-Lie

    2015-01-01

    Upregulation of protein kinase B (PKB, also known as Akt) is observed within the cerebral arteries of subarachnoid hemorrhage (SAH) animals. This study is of interest to examine Arctigenin, a potent antioxidant, on endothelial nitric oxide synthase (eNOS) and Akt pathways in a SAH in vitro study. Basilar arteries (BAs) were obtained to examine phosphatidylinositol-3-kinase (PI3K), phospho-PI3K, Akt, phospho-Akt (Western blot) and morphological examination. Endothelins (ETs) and eNOS evaluation (Western blot and immunostaining) were also determined. Arctigenin treatment significantly alleviates disrupted endothelial cells and tortured internal elastic layer observed in the SAH groups (p Arctigenin (p Arctigenin might exert dural effects in preventing SAH-induced vasospasm through upregulating eNOS expression via the PI3K/Akt signaling pathway and attenuate endothelins after SAH. Arctigenin shows therapeutic promise in the treatment of cerebral vasospasm following SAH. PMID:26539501

  11. Kelvin-Voigt黏弹性介质地震波场数值模拟与衰减特征%NUMERICAL MODELING AND ATTENUATION CHARACTERISTICS OF SEISMIC WAVEFIELD IN KELVIN-VOIGT VISCOELASTIC MEDIA

    Institute of Scientific and Technical Information of China (English)

    严红勇; 刘洋

    2012-01-01

    利用高阶交错网格有限差分模拟Kelvin-Voigt黏弹性介质中传播的地震波,同时将完全匹配层吸收边界条件引入到其边界处理中.数值模拟结果表明,完全匹配层吸收边界效果好,高阶有限差分能模拟得到的黏弹性介质波场精度较高.对模拟的黏弹性波场进行分析,表明介质的粘滞性使地震反射波的能量变弱,高频衰减明显,并比低频衰减得快,主频向低频方向移动,有效频带变窄,即降低了地震波的分辨率;并且反射转换波比反射纵波要衰减得快;而且还随着传播距离的增加,其峰值频率也逐渐降低.通过数值模拟分析具有不同的粘滞系数介质对地震波的吸收和衰减,结果表明随着粘滞系数的增大,地下介质对地震波的吸收衰减更明显.%This paper uses finite difference algorithm of high-order staggered-grid simula