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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. Lg Attenuation Modeling in the Middle East

    Science.gov (United States)

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

    2008-12-01

    We present a broadband tomographic model of Lg attenuation in the Middle East derived from source- and site-corrected amplitudes. The study region spans from Turkey through the Arabian Peninsula and Iran to Pakistan, Afghanistan, and northwest India. 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. 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. We will discuss the updated method and implications of this parameterization. A conjugate gradient method is used to tomographically invert the amplitude dataset of over 8000 paths. We solve for Q variation, as well as site and source terms, for a wide range of frequencies ranging from 0.5 -- 10 Hz. 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 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). This research was performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under contract number DE-AC52-07NA27344. This is LLNL contribution LLNL-ABS-406761.

  7. Cranking model and attenuation of Coriolis interaction

    International Nuclear Information System (INIS)

    Description of rotational bands of odd deformed nuclei in the self-consistent Cranking model (SCM) is given. Causes of attenuation of the Coriolis interaction in the nuclei investigated are studied, and account of bound of one-particle degrees of freedom with rotation of the Hartree-Fock-Bogolyubov (HFB) self-consistent method is introduced additionally to SCM for qualitative agreement with experimental data. Merits and shortages of SCM in comparison with the quadruparticle-rotor (QR) model are discussed. All know ways for constructing the Hamiltonian QR model (or analog of such Hamiltonian) on the basis of the microscopic theory are shown to include two more approximations besides others: quasi-particle-rotational interaction leading to pair break is taken into account in the second order of the perturbation theory; some exchange diagrams are neglected among diagrams of the second order according to this interaction. If one makes the same approximations in SCM instead of HFB method, then the dependence of level energies on spin obtained in this case is turned out to be close to the results of the QR model. Besides, the problem on renormalization of matrix elements of quasi-rotational interaction occurs in such nonself-consistent approach as in the QR model. In so far as the similar problem does not occur in SCM, one can make the conclusion that the problem of attenuation of Coriolis interaction involves the approximations given above

  8. 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.

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

    Czech Academy of Sciences Publication Activity Database

    Brázda, Vladimír; Fišer, Ondřej; Svoboda, Jaroslav

    BELLINGHAM: SPIE-INT SOC OPTICAL ENGINEERING, 2011 - (Majumdar, A.; Davis, C.), 81620N/1-81620N /8. (SPIE. Proceedings of SPIE. 8162). ISBN 978-0-8194-8772-8. ISSN 0277-786X. [Conference on Free- Space and Atmospheric Laser Communications /11./. San Diego (US), 24.08.2011-25.08.2011] R&D Projects: GA MŠk OC09027; GA ČR(CZ) GAP102/11/1376 Institutional research plan: CEZ:AV0Z30420517 Keywords : FSO link * atmospheric attenuation * attenuation prediction * attenuation modeling Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=1268911

  11. 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...

  12. 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.

  13. 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.

  14. Inverse problems of ultrasound tomography in models with attenuation

    International Nuclear Information System (INIS)

    We develop efficient methods for solving inverse problems of ultrasound tomography in models with attenuation. We treat the inverse problem as a coefficient inverse problem for unknown coordinate-dependent functions that characterize both the speed cross section and the coefficients of the wave equation describing attenuation in the diagnosed region. We derive exact formulas for the gradient of the residual functional in models with attenuation, and develop efficient algorithms for minimizing the gradient of the residual by solving the conjugate problem. These algorithms are easy to parallelize when implemented on supercomputers, allowing the computation time to be reduced by a factor of several hundred compared to a PC. The numerical analysis of model problems shows that it is possible to reconstruct not only the speed cross section, but also the properties of the attenuating medium. We investigate the choice of the initial approximation for iterative algorithms used to solve inverse problems. The algorithms considered are primarily meant for the development of ultrasound tomographs for differential diagnosis of breast cancer. (paper)

  15. 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

  16. 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].

  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. 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.

  20. 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.

  1. 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.

  2. Subduction zone guided waves: 3D modelling and attenuation effects

    Science.gov (United States)

    Garth, T.; Rietbrock, A.

    2013-12-01

    Hz (needed for dispersion analysis) for the large model area that is considered. Simulations with a variety of quality factors (Q) at different parts of the subduction zone have been run to investigate how seismic attenuation affects the observed dispersed waveforms. We show that the low Q in the mantle wedge can improve the fit of the dispersed waveforms. A low Q in the low velocity waveguide structure however means that the delayed high frequency energy has very low amplitude, and so is not seen clearly at the surface. The Q of the low velocity crustal waveguide must therefore be greater than 250, suggesting that melting does not occur in the subducted oceanic crust at depths of 220 km or less. The velocity contrast seen at these depths must therefore be due to compositional variations. Benchmarking 2D elastic models with the 3D case shows that 2D models give a good approximation of 3D subduction zone waveguide structure. Visco-elastic simulations show that attenuation in the mantle wedge affects the observed dispersion, but the low velocity waveguide itself does not have significantly reduced Q. This work is an example of how the increasing computing power coupled with well-defined model boundaries can allow high resolution 3D modelling to be applied to specific structures of interest.

  3. 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

  4. The development of attenuation compensation models of fluorescence spectroscopy signals

    Science.gov (United States)

    Dremin, Victor V.; Zherebtsov, Evgeny A.; Rafailov, Ilya E.; Vinokurov, Andrey Y.; Novikova, Irina N.; Zherebtsova, Angelina I.; Litvinova, Karina S.; Dunaev, Andrey V.

    2016-04-01

    This study examines the effect of blood absorption on the endogenous fluorescence signal intensity of biological tissues. Experimental studies were conducted to identify these effects. To register the fluorescence intensity, the fluorescence spectroscopy method was employed. The intensity of the blood flow was measured by laser Doppler flowmetry. We proposed one possible implementation of the Monte Carlo method for the theoretical analysis of the effect of blood on the fluorescence signals. The simulation is constructed as a four-layer skin optical model based on the known optical parameters of the skin with different levels of blood supply. With the help of the simulation, we demonstrate how the level of blood supply can affect the appearance of the fluorescence spectra. In addition, to describe the properties of biological tissue, which may affect the fluorescence spectra, we turned to the method of diffuse reflectance spectroscopy (DRS). Using the spectral data provided by the DRS, the tissue attenuation effect can be extracted and used to correct the fluorescence spectra.

  5. 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...

  6. Experimental Test of a New Precision Model for Microwave Rotary Vane Attenuators

    DEFF Research Database (Denmark)

    Guldbrandsen, Tom; Guldbrandsen, Birthe; Warner, Frank L.; Herman, Peter; Parkes, Gordon W.;

    1983-01-01

    Detailed measurements of scattering parameters have been made on a precision rotary vane attenuator (RVA) with high-resolution, direct angular readout. The aim of the measurements has been to test if the RVA can be used as a primary standard of attenuation by taking advantage of a precision model...

  7. 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.

  8. 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 $\

  9. 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 $\

  10. 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...

  11. 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.

  12. SU-E-T-233: Modeling Linac Couch Effects On Attenuation and Skin Dose

    International Nuclear Information System (INIS)

    Purpose: Treatment couch tops in medical LINAC rooms lead to attenuation to beams penetrating them, plus higher skin dose which can become a significant concern with the high fraction doses associated with Stereotactic Body Radiation Therapy. This work measures the attenuation and shallow depth dose due to a BrainLab couch, and studies the modeling of the couch top in our treatment planning system (TPS) as a uniform solid material with homogeneous density. Methods: LINAC photon beams of size 10×10 cm and nominal energy 6 MV were irradiated from different gantry angles on a stack of solid water. Depth dose were measured with two types of parallel plate chambers, MPPK and Markus. In the Philips Pinnacle TPS, the couch was modeled as a slab with varying thickness and density. A digital phantom of size 30×30×10 cm with density 1 g/cc was created to simulate the measurement setup. Both the attenuation and skin dose effects due to the couch were studied. Results: An orthogonal attenuation rate of 3.2% was observed with both chamber measurements. The attenuation can be modeled by couch models of varying thicknesses. Once the orthogonal attenuation was modeled well, the oblique beam attenuation in TPS agreed with measurement within 1.5%. The depth dose at shallow depth (0.5 cm) was also shown to be modeled correctly within 1.5% of the measurement using a 12 mm thick couch model with density of 0.9 g/cc. Agreement between calculation and measurement diverges at very shallow depths (≤1 mm) but remains acceptable (<5%) with the aforementioned couch model parameters. Conclusion: Modeling the couch top as a uniform solid in a treatment planning system can predict both the attenuation and surface dose simultaneously well within clinical tolerance in the same model

  13. A linear model approach for ultrasonic inverse problems with attenuation and dispersion.

    Science.gov (United States)

    Carcreff, Ewen; Bourguignon, Sébastien; Idier, Jérôme; Simon, Laurent

    2014-07-01

    Ultrasonic inverse problems such as spike train deconvolution, synthetic aperture focusing, or tomography attempt to reconstruct spatial properties of an object (discontinuities, delaminations, flaws, etc.) from noisy and incomplete measurements. They require an accurate description of the data acquisition process. Dealing with frequency-dependent attenuation and dispersion is therefore crucial because both phenomena modify the wave shape as the travel distance increases. In an inversion context, this paper proposes to exploit a linear model of ultrasonic data taking into account attenuation and dispersion. The propagation distance is discretized to build a finite set of radiation impulse responses. Attenuation is modeled with a frequency power law and then dispersion is computed to yield physically consistent responses. Using experimental data acquired from attenuative materials, this model outperforms the standard attenuation-free model and other models of the literature. Because of model linearity, robust estimation methods can be implemented. When matched filtering is employed for single echo detection, the model that we propose yields precise estimation of the attenuation coefficient and of the sound velocity. A thickness estimation problem is also addressed through spike deconvolution, for which the proposed model also achieves accurate results. PMID:24960708

  14. Attenuation of surface waves due to monsoon rains: A model study for the north Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Vethamony, P.; Kumar, B.P.; Sarma, Y.V.B.

    The dynamic interaction of intense rain with waves based on momentum exchange is applied to a second generation wave model to predict wave attenuation during monsoon. The scheme takes into account the characteristics of rain and wave parameters...

  15. 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-...

  16. 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...

  17. 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

  18. Measurement of gamma attenuation for ANR end shield model using CaSO4:Dy phosphor

    International Nuclear Information System (INIS)

    Highlights: ► Designing of Advanced Nuclear Reactor (ANR) end shield model. ► Measurement of gamma attenuation factor using CaSO4:Dy TL phosphor. ► Measurement of gamma attenuation factor under different conditions. ► Use of gamma attenuation factor for the actual end shield of ANR. ► Radiation level in the accessible area of ANR well below the permissible limit. - Abstract: In the present study, gamma attenuation factors were measured for End shield model of Advanced Nuclear Reactor (ANR). The model is of the size 700 × 700 × 1250 mm3 and made of steel ball and water mixture with 2 × 2 lattice locations at the centre of the model. The measurements were carried out using CaSO4:Dy TL phosphor. The streaming of gamma rays (includes core gamma, fission product gamma, activation gamma and capture gamma) was found to be attenuated by a factor of about 1500–4000 at a distance of 1125 mm from the incident face of the model, when it is filled with the mixture of water and steel ball. The corresponding exposure rate of streaming gamma rays was found to be about 1.2–2 R/h. The attenuation factors derived from the study was used for the designing of actual End shield for ANR

  19. 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.

  20. 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...

  1. Attenuation of Coriolis interaction in rotational model with truncated single-particle basis

    International Nuclear Information System (INIS)

    Attenuation of Coriolis interaction in frames of combined variant of rotational model based on σ-factor method is calculated. The given model makes use of representations of self-consistent cranking model to describe valent nucleons and phenomenological model based on solution of differential equation to establish core rotation frequency dependence on spin with availability of aligned angular momentum. Concrete calculations are carried out on the example of 164Er, which yrast-band peculiarities are caused by availability of aligned angular momentum. Estimated yrast-band energies confirm applicability of σ-factor method used in solutions of truncated basis problems to description of attenuation of Coriolis interaction

  2. 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.

  3. Improving Earthquake-Explosion Discrimination using Attenuation Models of the Crust and Upper Mantle

    Energy Technology Data Exchange (ETDEWEB)

    Pasyanos, M E; Walter, W R; Matzel, E M; Rodgers, A J; Ford, S R; Gok, R; Sweeney, J J

    2009-07-06

    In the past year, we have made significant progress on developing and calibrating methodologies to improve earthquake-explosion discrimination using high-frequency regional P/S amplitude ratios. Closely-spaced earthquakes and explosions generally discriminate easily using this method, as demonstrated by recordings of explosions from test sites around the world. In relatively simple geophysical regions such as the continental parts of the Yellow Sea and Korean Peninsula (YSKP) we have successfully used a 1-D Magnitude and Distance Amplitude Correction methodology (1-D MDAC) to extend the regional P/S technique over large areas. However in tectonically complex regions such as the Middle East, or the mixed oceanic-continental paths for the YSKP the lateral variations in amplitudes are not well predicted by 1-D corrections and 1-D MDAC P/S discrimination over broad areas can perform poorly. We have developed a new technique to map 2-D attenuation structure in the crust and upper mantle. We retain the MDAC source model and geometrical spreading formulation and use the amplitudes of the four primary regional phases (Pn, Pg, Sn, Lg), to develop a simultaneous multi-phase approach to determine the P-wave and S-wave attenuation of the lithosphere. The methodology allows solving for attenuation structure in different depth layers. Here we show results for the P and S-wave attenuation in crust and upper mantle layers. When applied to the Middle East, we find variations in the attenuation quality factor Q that are consistent with the complex tectonics of the region. For example, provinces along the tectonically-active Tethys collision zone (e.g. Turkish Plateau, Zagros) have high attenuation in both the crust and upper mantle, while the stable outlying regions like the Indian Shield generally have low attenuation. In the Arabian Shield, however, we find that the low attenuation in this Precambrian crust is underlain by a high-attenuation upper mantle similar to the nearby Red

  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. Dose attenuation by a carbon fiber linac couch and modeling with a treatment planning system

    International Nuclear Information System (INIS)

    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 treatment couch in a Varian Clinac 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 XiO 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).

  6. On the Impact of Building Attenuation Models in VANET Simulations of Urban Scenarios

    Directory of Open Access Journals (Sweden)

    Luis Urquiza-Aguiar

    2015-01-01

    Full Text Available 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 occasionally offer very accurate results. We compare three approaches to model the impact of buildings in the channel model of simulated VANETs in two urban scenarios. The simulation results for our evaluation scenarios of a traffic-efficiency application indicate that modeling the influence of buildings in urban areas as the total absence of communication between vehicles gives similar results to modeling such influence in a more realistic fashion and could be considered a conservative bound in the performance metrics.

  7. 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

  8. 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.

  9. A numerical study on turbulence attenuation model for liquid droplet impingement erosion

    International Nuclear Information System (INIS)

    Research highlights: → Applying a carrier turbulence algorithm attenuation to liquid droplet impingement (LDI) phenomena in two phase flow. → Proposing a computational procedure to LDI erosion rate in a bent pipe. → Investigating the carrier turbulence attenuation influence to the LDI erosion rate. - Abstract: The bent pipe wall thinning has been often found at the elbow of the drain line and the high-pressure secondary feed-water bent pipe in the nuclear reactors. The liquid droplet impingement (LDI) erosion could be regarded to be one of the major causes and is a significant issue of the thermal hydraulics and structural integrity in aging and life extension for nuclear power plants safety. In this paper two-phase numerical simulations are conducted for standard elbow geometry, typically the pipe diameter is 170 mm. The turbulence attenuation in vapor-droplets flow is analysed by a damping function on the energy spectrum basis of single phase flow. Considering the vapor turbulent kinetic energy attenuation due to the involved droplets, a computational fluid dynamic (CFD) tool has been adopted by using two-way vapor-droplet coupled system. This computational fluid model is built up by incompressible Reynolds Averaged Navier-Stoke equations using standard k-ε model and the SIMPLE algorithm, and the numerical droplet model adopts the Lagrangian approach, a general LDI erosion prediction procedure for bent pipe geometry has been performed to supplement the CFD code. The liquid droplets diameter, velocity, volume concentration are evaluated for the effects of carrier turbulence attenuation. The result shows that carrier turbulence kinetic energy attenuation is proved to be an important effect for LDI erosion rate when investigating the bent pipe wall thinning phenomena.

  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. 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...

  14. 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.

  15. Attenuation of numerical artefacts in the modelling of fluid interfaces

    Science.gov (United States)

    Evrard, Fabien; van Wachem, Berend G. M.; Denner, Fabian

    2015-11-01

    Numerical artefacts in the modelling of fluid interfaces, such as parasitic currents or spurious capillary waves, present a considerable problem in two-phase flow modelling. Parasitic currents result from an imperfect evaluation of the interface curvature and can severely affect the flow, whereas spatially underresolved (spurious) capillary waves impose strict limits on the time-step and, hence, dictate the required computational resources for surface-tension-dominated flows. By applying an additional shear stress term at the fluid interface, thereby dissipating the surface energy associated with small wavelengths, we have been able to considerably reduce the adverse impact of parasitic currents and mitigate the time-step limit imposed by capillary waves. However, a careful choice of the applied interface viscosity is crucial, since an excess of additional dissipation compromises the accuracy of the solution. We present the derivation of the additional interfacial shear stress term, explain the underlying physical mechanism and discuss the impact on parasitic currents and interface instabilities based on a variety of numerical experiments. We acknowledge financial support from the Engineering and Physical Sciences Research Council (EPSRC) through Grant No. EP/M021556/1 and from PETROBRAS.

  16. 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.

  17. Sympathectomy attenuates excitability of dorsal root ganglion neurons and pain behaviour in a lumbar radiculopathy model

    OpenAIRE

    Iwase, T; Takebayashi, T; Tanimoto, K; Terashima, Y.; Miyakawa, T.; Kobayashi, T.; Tohse, N.; Yamashita, T

    2012-01-01

    Objectives In order to elucidate the influence of sympathetic nerves on lumbar radiculopathy, we investigated whether sympathectomy attenuated pain behaviour and altered the electrical properties of the dorsal root ganglion (DRG) neurons in a rat model of lumbar root constriction. Methods Sprague-Dawley rats were divided into three experimental groups. In the root constriction group, the left L5 spinal nerve root was ligated proximal to the DRG as a lumbar radiculopathy model. In the root con...

  18. 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.

  19. 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...

  20. 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

  1. Relating wave attenuation to pancake ice thickness, using field measurements and model results

    Science.gov (United States)

    Doble, Martin J.; De Carolis, Giacomo; Meylan, Michael H.; Bidlot, Jean-Raymond; Wadhams, Peter

    2015-06-01

    Wave attenuation coefficients (α, m-1) were calculated from in situ data transmitted by custom wave buoys deployed into the advancing pancake ice region of the Weddell Sea. Data cover a 12 day period as the buoy array was first compressed and then dilated under the influence of a passing low-pressure system. Attenuation was found to vary over more than 2 orders of magnitude and to be far higher than that observed in broken-floe marginal ice zones. A clear linear relation between α and ice thickness was demonstrated, using ice thickness from a novel dynamic/thermodynamic model. A simple expression for α in terms of wave period and ice thickness was derived, for application in research and operational models. The variation of α was further investigated with a two-layer viscous model, and a linear relation was found between eddy viscosity in the sub-ice boundary layer and ice thickness.

  2. Comparison of reactive transport model predictions for natural attenuation processes occurring at chlorinated solvent contaminated site

    Science.gov (United States)

    Chiu, H. M.; Tsai, C. H.; Lai, K. H.; Chen, J. S.

    2014-12-01

    Prediction of an analytical model and numerical model, namely BIOCLOR and HYDRODEOCHEM, for a test scenario involving the natural attenuations of dissolved solvent at chlorinated contaminated site are compared. Two models make same predictions for PCE, TCE and DCE and considerable different predictions for VC and ETH for the case of all species having identical retardation factors. Significant discrepancies between two models are observed for all species when retardation coefficients are considered to be different for all species. These differences can be attributed to the basic assumption that all the species have the same retardation factors embedded in BIOCHLOR.

  3. A microwave propagation model for estimation of effective attenuation coefficients in a vegetation canopy

    International Nuclear Information System (INIS)

    This article presents a detailed theoretical model for propagation of microwave in a layer of vegetation medium. The vegetation medium is modeled by a layer of randomly distributed dielectric circular disks and cylinders, representing the leaves and the stems, respectively. Propagation of wave in such a medium is taken as a transport of energy problem, and is formulated by a Monte Carlo method. Interactions of wave with the vegetation components are treated as a sequence of multiple scattering events between the photon flux and the scatterers. A Monte Carlo algorithm is used to track these collision processes, and the energy of the photon leaving the vegetation layer is collected. With sufficient number of photon histories, the ensemble averages of the photon energy are used to calculate the attenuation coefficients of the wave through the vegetation layer. Our simulation results indicate that attenuation coefficients calculated using this multiple scattering model may differ from those given by a simple single scattering model. Effects on the attenuation coefficients by various parameters such as moisture content, scatterer's size, and volume fraction are studied. Comparisons of the calculated results are made with the measured data and good match is obtained. (author)

  4. Attenuation of disturbances introduced by dynamic links in precision motion systems using model-based observers

    OpenAIRE

    Hoogerkamp, M.; Waiboer, R.R.; Dijk, van, B.W.; Aarts, R.G.K.M.

    2014-01-01

    This paper presents an extension to the Unknown Input Disturbance Observer (UIDO) and the Disturbance Estimation Filter (DEF). This extension enables the inclusion of the mechanics of dynamic links to the observer model, in order to attenuate the specific disturbances introduced by those dynamic links. A design method of the state space feedback gain based on the dynamics, and an observer gain based on basic Kalman filter theory is given. It is shown how the observer is designed for a practic...

  5. Evaluation of the FASTCHEM model for predicting leachate attenuation at fossil power plants

    International Nuclear Information System (INIS)

    The Tennessee Valley Authority (TVA) has applied the model FASTCHEM to identify retardation mechanisms and predict solute transport at two fossil power plants. FASTCHEM (acronym for fly ash and flue gas desulfurization sludge transport and geochemistry) was developed to model the adsorption, ion exchange. and precipitation of major anions, major cations, and heavy metals in a two-dimensional groundwater flow regime. The capacity of the soil to attenuate leachate components was modelled at two power plants. Predictions show significant precipitation of barium and adsorption and ion exchange for cadmium, chromium and zinc. Several critical details in applying FASTCHEM are addressed in this paper

  6. 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.

  7. HIGH-RESOLUTION SEISMIC VELOCITY AND ATTENUATION MODELS OF THE CAUCASUS-CASPIAN REGION

    Energy Technology Data Exchange (ETDEWEB)

    Mellors, R; Gok, R; Sandvol, E

    2007-07-10

    The southwest edge of Eurasia is a tectonically and structurally complex region that includes the Caspian and Black Sea basins, the Caucasus Mountains, and the high plateaus south of the Caucasus. Crustal and upper mantle velocities show great heterogeneity in this region and regional phases display variations in both amplitudes and travel time. Furthermore, due to a lack of quality data, the region has largely been unexplored in terms of the detailed lithospheric seismic structure. A unified high-resolution 3D velocity and attenuation model of the crust and upper mantle will be developed and calibrated. This model will use new data from 23 new broadband stations in the region analyzed with a comprehensive set of techniques. Velocity models of the crust and upper mantle will be developed using a joint inversion of receiver functions and surface waves. The surface wave modeling will use both event-based methods and ambient noise tomography. Regional phase (Pg, Pn, Sn, and Lg) Q model(s) will be constructed using the new data in combination with existing data sets. The results of the analysis (both attenuation and velocity modeling) will be validated using modeling of regional phases, calibration with selected events, and comparison with previous work. Preliminary analyses of receiver functions show considerable variability across the region. All results will be integrated into the KnowledgeBase.

  8. 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.

  9. 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

  10. Pore-scale modeling of pore structure effects on P-wave scattering attenuation in dry rocks.

    Directory of Open Access Journals (Sweden)

    Zizhen Wang

    Full Text Available Underground rocks usually have complex pore system with a variety of pore types and a wide range of pore size. The effects of pore structure on elastic wave attenuation cannot be neglected. We investigated the pore structure effects on P-wave scattering attenuation in dry rocks by pore-scale modeling based on the wave theory and the similarity principle. Our modeling results indicate that pore size, pore shape (such as aspect ratio, and pore density are important factors influencing P-wave scattering attenuation in porous rocks, and can explain the variation of scattering attenuation at the same porosity. From the perspective of scattering attenuation, porous rocks can safely suit to the long wavelength assumption when the ratio of wavelength to pore size is larger than 15. Under the long wavelength condition, the scattering attenuation coefficient increases as a power function as the pore density increases, and it increases exponentially with the increase in aspect ratio. For a certain porosity, rocks with smaller aspect ratio and/or larger pore size have stronger scattering attenuation. When the pore aspect ratio is larger than 0.5, the variation of scattering attenuation at the same porosity is dominantly caused by pore size and almost independent of the pore aspect ratio. These results lay a foundation for pore structure inversion from elastic wave responses in porous rocks.

  11. 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...

  12. LERC-SLAM - THE NASA LEWIS RESEARCH CENTER SATELLITE LINK ATTENUATION MODEL PROGRAM (IBM PC VERSION)

    Science.gov (United States)

    Manning, R. M.

    1994-01-01

    The frequency and intensity of rain attenuation affecting the communication between a satellite and an earth terminal is an important consideration in planning satellite links. The NASA Lewis Research Center Satellite Link Attenuation Model Program (LeRC-SLAM) provides a static and dynamic statistical assessment of the impact of rain attenuation on a communications link established between an earth terminal and a geosynchronous satellite. The program is designed for use in the specification, design and assessment of satellite links for any terminal location in the continental United States. The basis for LeRC-SLAM is the ACTS Rain Attenuation Prediction Model, which uses a log-normal cumulative probability distribution to describe the random process of rain attenuation on satellite links. The derivation of the statistics for the rainrate process at the specified terminal location relies on long term rainfall records compiled by the U.S. Weather Service during time periods of up to 55 years in length. The theory of extreme value statistics is also utilized. The user provides 1) the longitudinal position of the satellite in geosynchronous orbit, 2) the geographical position of the earth terminal in terms of latitude and longitude, 3) the height above sea level of the terminal site, 4) the yearly average rainfall at the terminal site, and 5) the operating frequency of the communications link (within 1 to 1000 GHz, inclusive). Based on the yearly average rainfall at the terminal location, LeRC-SLAM calculates the relevant rain statistics for the site using an internal data base. The program then generates rain attenuation data for the satellite link. This data includes a description of the static (i.e., yearly) attenuation process, an evaluation of the cumulative probability distribution for attenuation effects, and an evaluation of the probability of fades below selected fade depths. In addition, LeRC-SLAM calculates the elevation and azimuth angles of the terminal

  13. Shadow Detection Using Tricolor Attenuation Model Enhanced with Adaptive Histogram Equalization

    Directory of Open Access Journals (Sweden)

    Jyothisree V.

    2013-05-01

    Full Text Available Shadows create significant problems in many computer vision and image analysis tasks such as objectrecognition, object tracking, and image segmentation. For a machine, it is very difficult to distinguishbetween a shadow and a real object. As a result, an object recognition system may incorrectly recognize ashadow region as an object. So the detection of shadows in images will enhance the performance of manymachine vision tasks. This paper implements a shadow detection method, which is based on TricolorAttenuation Model (TAM enhanced with adaptive histogram equalization (AHE. TAM uses the concept ofintensity attenuation of pixels in the shadow region which is different for the three color channels. Itoriginates from the idea that if the minimum attenuated color channel is subtracted from the maximumattenuated one, the shadow areas become darker in the resulting TAM image. But this resulting image willbe of low contrast due to the high correlation among R, G and B color channels. In order to enhance thecontrast, adaptive histogram equalization is used. The incorporation of AHE significantly improved thequality of the detected shadow region.

  14. Activated protein C attenuates acute lung injury and apoptosis in a hyperoxic animal model.

    Science.gov (United States)

    Husari, Ahmad W; Khayat, Aline; Awdeh, Haitham; Hatoum, Hadi; Nasser, Michel; Mroueh, Salman M; Zaatari, Ghazi; El-Sabban, Marwan; Dbaibo, Ghassan S

    2010-05-01

    Evidence suggests that activated protein C (APC) attenuates acute lung injury (ALI) through antithrombotic and anti-inflammatory mechanisms. The aim of this study was to determine the effects of APC on ALI in adult rats exposed to hyperoxic environment. Rats were divided into control, hyperoxia, hyperoxia + APC, and APC. Hyperoxia and hyperoxia + APC were exposed to 1, 3, and 5 days of hyperoxia. Hyperoxia + APC and APC were injected with APC (5 mg/kg, i.p.) every 12 h. Control and hyperoxia received isotonic sodium chloride solution injection. Measurement of wet to dry ratio and albumin leak demonstrated significant improvement in hyperoxia + APC when compared with hyperoxia. Apoptosis, as measured by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, was significantly reduced in hyperoxia + APC when compared with hyperoxia. Histological evaluation of lung sections showed significant reduction in inflammation, edema, and in the number of marginating neutrophils in hyperoxia + APC as compared with hyperoxia. Transcriptional expression of lung inflammatory mediators demonstrated a time-dependent surge in the levels TNF-alpha, IL-1beta, and IL-6 in response to hyperoxia that was attenuated with APC administration in the presence of hyperoxia. In this rat model, APC attenuates lung injury and the expression of inflammatory mediators in ALI secondary to hyperoxia. PMID:19851127

  15. 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.

  16. 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.

  17. Explaining anisotropic macroseismic fields in terms of fault zone attenuation-A simple model

    Science.gov (United States)

    Sovic, Ivica; Sariri, Kristina

    2016-06-01

    In this work, we present a simple model of anisotropic macroseismic field based on the assumption that local and regional geological structures change the shape of the isotropic macroseismic field (as expected in 1D media). Local geological structures, like water saturated stratified media, may increase intensity level by multiple reflections, constructive interference and resonant effects, but inelastic attenuation, significantly stronger in water-saturated soils, as well as destructive interference, may decrease intensities. On the other hand, large geological structures like seismotectonically active fault zones decrease intensities due to energy redistribution and inelastic attenuation. This model has been developed for the Karst region of the Outer Dinarides where site effects may be neglected because of specific building construction. Neglecting of site effects simplifies the model, so we just need a map of seismically active faults acting as modulator of macroseismic field. In order to demonstrate how the model works, we have calculated the standard error for 10 earthquakes and the macroseismic fields for three of them with epicenters in the Outer Dinarides and compared the model to empiric isoseismals.

  18. Natural attenuation of BTEX compounds: model development and field-scale application.

    Science.gov (United States)

    Lu, G; Clement, T P; Zheng, C; Wiedemeier, T H

    1999-01-01

    Benzene, toluene, ethyl benzene and xylene (BTEX) dissolved into ground water and migrated from a light nonaqueous phase liquid (LNAPL) source in a sandy aquifer near a petroleum, oil, and lubricants (POL) facility at Hill Air Force Base (AFB), Utah. Field observations indicated that microbially mediated BTEX degradation using multiple terminal electron-accepting processes including aerobic respiration, denitrification, Fe(III) reduction, sulfate reduction, and methanogenesis has occurred in the aquifer. To study the transport and transformation of dissolved BTEX compounds under natural conditions, a reactive flow and transport model incorporating biochemical multispecies interactions and BTEX was developed. The BTEX, oxygen, nitrate, Fe(II), sulfate, and methane plumes calculated by the model agree reasonably well with field observations. The first-order biodegradation rate constants, estimated based on model calibration are 0.051, 0.031, 0.005, 0.004, and 0.002 day(-1) for aerobic respiration, denitrification, Fe(III), sulfate reduction, and methanogenesis, respectively. The results of a sensitivity analysis show that the saturated aquifer thickness, hydraulic conductivity, and reaction rate constants are the most critical parameters controlling the natural attenuation of BTEX at this site. The hydraulic conductivity and aquifer thickness were found to be the key factors affecting the restoration of oxygen, nitrate, and sulfate after their interaction with the BTEX plume. The multispecies reactive transport modeling effort, describing BTEX degradation mediated by multiple electron-accepting processes, represents one of the few attempts to date to quantify a complete sequence of natural attenuation processes with a detailed field data set. Because the case study is representative of many petroleum-product contaminated sites, the results and insights obtained from this study are of general interest and relevance to other fuel-hydrocarbon natural attenuation sites

  19. 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.

  20. 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 ...

  1. Analytical model for the excitation of leaky surface plasmon polaritons in the attenuated total reflection configuration

    Science.gov (United States)

    Jia, Hongwei; Xie, Yunya; Liu, Haitao; Zhong, Ying

    2016-05-01

    We propose a fully-analytical model for the excitation of leaky surface plasmon polariton (SPP) in the attenuated total reflection (ATR) configuration under illumination by a finite-width beam of electromagnetic wave. The model is built up on the basis of the general unconjugated-form reciprocity theorem and is able to predict the excitation amplitude and phase of the leaky SPP at a quantitative level. The validity of the model is carefully supported through a comparison with the numerical results obtained with the mode orthogonality. With the model a physical understanding of the resonant excitation of the leaky SPP is achieved and the optimal parameters such as the incidence angle and the beam width to ensure an efficient SPP excitation are demonstrated for design tasks.

  2. 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.

  3. 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.

  4. Model testing of a 10-kg high explosive blast attenuation maze

    International Nuclear Information System (INIS)

    The basement area of the proposed High Explosive Applications Facility (HEAF) at the Lawrence Livermore National Laboratory includes 10-kg HE assembly and process cells, and a 10-kg corridor for the transport of up to 10 kg of HE from the receiving dock to the cells and to the experimental firing tanks. Previous model experiments developed a process cell-maze configuration that attenuated the effects of an accidental 10-kg detonation to acceptable levels (maximum of 10 to 11 psi reflected). This document reports 1/8-scale model tests conducted to confirm the maze design and to determine the blast pressures in adjacent areas in the final HEAF building configuration. In addition, pressure/time information was obtained at selected points in the model expansion chamber to provide the architect-engineer with information for structural design

  5. 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.

  6. 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.

  7. HIGH-RESOLUTION SEISMIC VELOCITY AND ATTENUATION MODELS OF THE CAUCASUS-CASPIAN REGION

    Energy Technology Data Exchange (ETDEWEB)

    Mellors, R; Gok, R; Pasyanos, M; Skobeltsyn, G; Teoman, U; Godoladze, T; Sandvol, E

    2008-07-01

    The southwest edge of Eurasia is a tectonically and structurally complex region that includes the Caspian and Black Sea basins, the Caucasus Mountains, and the high plateaus south of the Caucasus. Using data from 25 broadband stations located in the region, new estimates of crustal and upper mantle thickness, velocity structure, and attenuation are being developed. Receiver functions have been determined for all stations. Depth to Moho is estimated using slant stacking of the receiver functions, forward modeling, and inversion. Moho depths along the Caspian and in the Kura Depression are in general poorly constrained using only receiver functions due to thick sedimentary basin sediments. The best fitting models suggest a low velocity upper crust with Moho depths ranging from 30 to 40 km. Crustal thicknesses increase in the Greater Caucasus with Moho depths of 40 to 50 km. Pronounced variations with azimuth of source are observed indicating 3D structural complexity and upper crustal velocities are higher than in the Kura Depression to the south. In the Lesser Caucasus, south and west of the Kura Depression, the crust is thicker (40 to 50 km) and upper crustal velocities are higher. Work is underway to refine these models with the event based surface wave dispersion and ambient noise correlation measurements from continuous data. Regional phase (Lg and Pg) attenuation models as well as blockage maps for Pn and Sn are being developed. Two methods are used to estimate Q: the two-station method to estimate inter-station Q and the reversed, two-station, two event method. The results are then inverted to create Lg and Pg Q maps. Initial results suggest substantial variations in both Pg and Lg Q in the region. A zone of higher Pg Q extends west from the Caspian between the Lesser and Greater Caucasus and a narrow area of higher Lg Q is observed.

  8. 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.

  9. Neuregulin-1 attenuates cognitive function impairments in a transgenic mouse model of Alzheimer's disease

    Science.gov (United States)

    Ryu, J; Hong, B-H; Kim, Y-J; Yang, E-J; Choi, M; Kim, H; Ahn, S; Baik, T-K; Woo, R-S; Kim, H-S

    2016-01-01

    The neuregulin (NRG) family of epidermal growth factor-related proteins is composed of a wide variety of soluble and membrane-bound proteins that exert their effects via the tyrosine kinase receptors ErbB2-ErbB4. In the nervous system, the functions of NRG1 are essential for peripheral myelination, the establishment and maintenance of neuromuscular and sensorimotor systems and the plasticity of cortical neuronal circuits. In the present study, we report that an intracerebroventricular infusion of NRG1 attenuated cognitive impairments in 13-month-old Tg2576 mice, an animal model of Alzheimer's disease (AD). In addition, according to Golgi-Cox staining, NRG1 rescued the reduction in the number of dendritic spines detected in the brains of Tg2576 mice compared with vehicle (PBS)-infused mice. This result was also corroborated in vitro as NRG1 attenuated the oligomeric amyloid beta peptide1-42 (Aβ1-42)-induced decrease in dendritic spine density in rat primary hippocampal neuron cultures. NRG1 also alleviated the decrease in neural differentiation induced by oligomeric Aβ1-42 in mouse fetal neural stem cells. Collectively, these results suggest that NRG1 has a therapeutic potential for AD by alleviating the reductions in dendritic spine density and neurogenesis found in AD brains. PMID:26913607

  10. 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

  11. 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.

  12. 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...

  13. 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

  14. 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.

  15. Validation of mathematical models to describe fluid dynamics of a cold riser by gamma ray attenuation

    International Nuclear Information System (INIS)

    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

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. Computational Modeling of Micro-Crack Induced Attenuation in CFRP Composites

    Science.gov (United States)

    Roberts, R. A.; Leckey, C. A. C.

    2012-01-01

    A computational study is performed to determine the contribution to ultrasound attenuation in carbon fiber reinforced polymer composite laminates of linear elastic scattering by matrix micro-cracking. Multiple scattering approximations are benchmarked against exact computational approaches. Results support linear scattering as the source of observed increased attenuation in the presence of micro-cracking.

  1. Computational modeling of micro-crack induced attenuation in CFRP composites

    Science.gov (United States)

    Roberts, R. A.; Leckey, C. A. C.

    2013-01-01

    A computational study is performed to determine the contribution to ultrasound attenuation in carbon fiber reinforced polymer composite laminates of linear elastic scattering by matrix micro-cracking. Multiple scattering approximations are benchmarked against exact computational approaches. Results support linear scattering as the source of observed increased attenuation in the presence of micro-cracking.

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

    International Nuclear Information System (INIS)

    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

  4. 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.

  5. 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.

  6. Concurrent attenuation of, and energy harvesting from, surface vibrations: experimental verification and model validation

    International Nuclear Information System (INIS)

    Fundamental studies in vibrational energy harvesting consider the electromechanically coupled devices to be excited by uniform base vibration. Since many harvester devices are mass–spring systems, there is a clear opportunity to exploit the mechanical resonance in a fashion identical to tuned mass dampers to simultaneously suppress the vibration of the host structure via reactive forces while converting the ‘absorbed’ vibration into electrical power. This paper presents a general analytical model for the coupled electro-elastic dynamics of a vibrating panel to which distributed energy harvesting devices are attached. One such device is described which employs a corrugated piezoelectric spring layer. The model is validated by comparison to measured elastic and electric frequency response functions. Tests on an excited panel show that the device, contributing 1% additional mass to the structure, concurrently attenuates the lowest panel mode accelerance by >20 dB while generating 0.441 µW for a panel drive acceleration of 3.29 m s−2. Adjustment of the load resistance connected to the piezoelectric spring layer verifies the analogy between the present harvester device and an electromechanically stiffened and damped vibration absorber. The results show that maximum vibration suppression and energy harvesting objectives occur for nearly the same load resistance in the harvester circuit. (paper)

  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. 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.

  9. 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.

  10. 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

  11. 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

  12. 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

  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. 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.

  15. 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

  16. 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

  17. 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

  18. 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

  19. 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.

    and analysis of P-wave attenuation anisotropy in transversely isotropic media Yaping Zhu1, Ilya Tsvankin2, Pawan Dewangan3, and Kasper van Wijk4 ABSTRACT Anisotropic attenuation can provide sensitive attributes for fracture detection and lithology...-preserving migration, and seismic fracture detec- tion. INTRODUCTION Most existing publications on seismic anisotropy are devoted to the influence of angular velocity variation in purely elastic media on the traveltimes and amplitudes of seismic waves. It is likely...

  20. Seismic modelling study of P-wave attenuation and velocity dispersion in patchy-saturated porous media

    International Nuclear Information System (INIS)

    Seismic wave propagation in patchy-saturated porous media is studied by numerical simulation in time domain at the seismic frequency band (1–1000 Hz). The models consist of hundreds of representative elementary volumes (REVs), where the REV is partially saturated with water and gas pockets. Seismic modelling experiments are implemented in a traditional way, with ‘periodic’ boundary conditions applied to get rid of undrained boundary conditions at the outer edges of the REVs. The characteristics of confining pressure, induced pore pressure, solid particle velocities and Darcy filtration velocities are analysed. The snapshots show that strong pore pressure gradients are generated across the interface between gas and water phases, and significant fluid flow occurs. The conversion of a fast P-wave into a dissipating slow P-wave takes place at seismic frequencies, and the converted slow P-wave diffuses strongly in both gas- and water-saturated phases. These numerical results can help us to understand the loss mechanism at seismic frequencies. Then, P-wave attenuation and velocity dispersion of a heterogeneous REV are calculated during traditional seismic modelling at seismic frequencies. The numerical results show good agreement with theoretical predictions obtained from patchy saturation theory. Furthermore, the effects of different fluid distributions on P-wave attenuation and velocity dispersion are analysed numerically. A series of experiments are implemented by considering large, small and random gas-patchy inclusions. The decrease of gas pocket size makes the peak frequency move towards high frequencies. Random distribution of gas patches may affect both the peak attenuation and peak frequencies. Seismic attenuation caused by Biot global flow, elastic scattering and wave-induced fluid flow (WIFF) associated with patchy saturation are computed numerically. The results show that the contribution of Biot’s global flow and scattering to the overall

  1. Ketamine attenuates osteoarthritis of the knee via modulation of inflammatory responses in a rabbit model.

    Science.gov (United States)

    Lu, Wei; Wang, Lin; Wo, Chunxin; Yao, Jing

    2016-06-01

    The aim of the present study was to investigate the efficacy of ketamine in attenuating osteoarthritis (OA) and modulating the expression of inflammatory mediators. A rabbit OA model was established by knee immobilization using plaster bandages. After six weeks, rabbits were randomly allocated into four groups (n=6/group): Normal saline, Ket60, Ket100, and Ket200 and twice a week for four weeks the rabbits received an intra‑articular injection of saline, or 60, 100 or 200 µmol/l ketamine, respectively. One week after the final injection, samples of synovial membrane, synovial fluid and articular cartilage were isolated. The pathological changes were assessed by general observation, hematoxylin and eosin staining and Alcian blue/periodic‑acid Schiff staining. Cartilage pathology was assessed using Mankin's scoring system. Tumor necrosis factor (TNF)‑α and interleukin (IL)‑10 levels in the synovial fluid were measured by enzyme‑linked immunosorbent assays. The nuclear factor (NF)‑κB p65 subunit expression level in cartilage samples was determined by immunohistochemistry. OA was characterized by morphological changes in the articular surface, cartilage lesions, infiltration of inflammatory cells and a significantly increased Mankin's score. Elevated TNF‑α and reduced IL-10 levels in the synovial fluid, along with increased p65 expression levels in the cartilage were observed in OA rabbits. Intra‑articular injection of ketamine ameliorated the pathological characteristics of OA, reduced the Mankin's score, decreased TNF‑α and NF‑κB p65 expression levels, and increased the level of IL‑10 expression in a dose-dependent manner. Thus is was demonstrated that Ketamine suppresses the inflammatory response in OA by modulating inflammatory mediator expression levels in a rabbit model of OA. PMID:27109206

  2. Modelling and measurement of inter-speed attenuation effects on dosimetry of I-125 seed implants for prostate brachytherapy

    International Nuclear Information System (INIS)

    Full text: TG43 based dose calculations for prostate permanent 1-125 seed implants ignore the effects of inter-seed attenuation (lSA). This study investigates the magnitude of ISA effects in simple seed arrangements and clinical implants using Monte Carlo (MC) simulation techniques. MC results are verified with experimental dose measurements. lSA effects for Oncura model 6711 and Thinseed (9011) are compared. MC simulations were performed with MCNPX v2.5.0. Seed models 6711 and 9011 were simulated singly to verify the accuracy of the model by comparison to previously published data. Then simple two seed arrangements and full clinical implant arrangements were simulated to assess ISA effects and consequences for typical patient DYH parameters. Experimental dose measurements using a MOSFET in a PMMA phantom were used to validate MC simulation results. Close agreement with published data was achieved for both seed models. Two seed arrangements demonstrate significant attenuation along the source transverse axis with the 90 II being slightly less attenuating. Clinical simulations show that ISA has significant effects on clinical dose-volume histogram (DYH) parameters. Experimental dose measurements agree with MC simulation results. Conclusion The study demonstrates the need to take account of ISA effects in permanent 1-125 seed implant treatments for accurate dosimetry. Ongoing work will investigate post implant dosimetry using MC simulation to determine in which circumstances ISA effects are clinically significant.

  3. Exercise during early, but not late abstinence, attenuates subsequent relapse vulnerability in a rat model.

    Science.gov (United States)

    Beiter, R M; Peterson, A B; Abel, J; Lynch, W J

    2016-01-01

    Exercise has shown promise as a nonpharmacological intervention for addiction, with evidence suggesting a potential utility for relapse prevention. In humans, exercise as an intervention is typically introduced well after the initiation of abstinence, yet neurobiological data from preclinical studies suggest that it may be more effective if initiated during early abstinence. Here, using rat models, we determined whether the beneficial effects of exercise on relapse vulnerability depends on when exercise is first initiated, during early versus late abstinence. Once rats (n=47) acquired cocaine self-administration, they were given 24-h access to cocaine (1.5 mg/kg per infusion) under a discrete trial procedure (four infusions per hour) for 10 days. The rats then began a 14-day abstinence period in which they had access (2 h per day) to a locked wheel throughout abstinence (sedentary) or an unlocked wheel during early (days 1-7), late (days 8-14) or throughout (days 1-14) abstinence (n=10-14 per group). Cocaine seeking, as assessed under an extinction/cued-induced reinstatement procedure, was examined on day 15 of abstinence. Exercise beginning during early abstinence robustly attenuated subsequent cocaine seeking, and this effect persisted even when exercise ended on the seventh day of abstinence. In contrast, exercise during late abstinence was not effective and these animals displayed high levels of cocaine seeking similar to those observed in sedentary animals. These results indicate that the timing of exercise availability differentially impacts cocaine seeking with results suggesting that exercise during early, but not late, abstinence may provide long-term protection against cocaine relapse. PMID:27115123

  4. 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...

  5. 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...

  6. Modeling of Fog and Smoke Attenuation in Free Space Optical Communications Link Under Controlled Laboratory Conditions

    Czech Academy of Sciences Publication Activity Database

    Ijaz, M.; Ghassemlooy, Z.; Pešek, J.; Fišer, Ondřej; Le Minh, H.; Bentley, E.

    2013-01-01

    Roč. 31, č. 11 (2013), s. 1720-1726. ISSN 0733-8724 R&D Projects: GA ČR(CZ) GAP102/11/1376 Institutional support: RVO:68378289 Keywords : Fog attenuation * free space optics * smoke attenuation * visibility Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 2.862, year: 2013 http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6497447&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D6497447

  7. Hot water extract of wheat bran attenuates white matter injury in a rat model of vascular dementia.

    Science.gov (United States)

    Lim, Sun Ha; Lee, Jongwon

    2014-09-01

    Vascular dementia is characterized by white matter lesions involving the demyelination and activation of astrocytes and microglia. In a previous study, we showed that the supernatant of a laboratory-scale, hot water extract of ground whole wheat (TALE) attenuated white matter injury and astrocytic activation in a rat model of bilateral common carotid artery occlusion (BCCAO). In the present study, we made several modifications to the hot water extraction process to remove starch and enable large-scale production. We used wheat bran (WB), which contains less starch, instead of ground whole wheat. In addition, we removed starch granules with a decanter before hot water extraction. The final product, wheat bran extract (WBE), contained 2.42% arabinose, a surrogate marker of arabinoxylan, which is an active constituent of WBE. Supplementation of the rat model of BCCAO with WBE (400 mg/kg/day) for 33 days attenuated white matter injury, which was assessed by Luxol Fast Blue staining, in the corpus callosum (cc) and optic tract (opt) regions. Attenuation of white matter injury in the opt region was accompanied by improvement of the pupillary light reflex. Immunochemical staining revealed that supplementation with WBE reduced astrocytic activation in the cc and opt regions and reduced microglial activation in the opt region. These findings indicate that supplementation with WBE is effective at attenuating white matter injury accompanied by the inhibition of astrocytic and microglial activation. Therefore, extracts from WB, a cheap by-product of wheat milling, can be developed as a nutraceutical to prevent vascular dementia, a disease for which there is no approved pharmaceutical treatment. PMID:25320711

  8. 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.

  9. 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

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

    Czech Academy of Sciences Publication Activity Database

    Fišer, Ondřej; Brázda, V.; Wilfert, O.

    Bellingham: Society of Photo-Optical Instrumentation Engineers, 2015. (Proceedings of SPIE). ISBN 978-1-62841-780-7. ISSN 0277-786X. [SPIE Optics + Photonics. San Diego (US), 10.08.2015-12.08.2015] R&D Projects: GA MŠk(CZ) LD13036 Institutional support: RVO:68378289 Keywords : free space optics * attenuation * visibility * rain rate * turbulence * sonic temperature Subject RIV: DG - Athmosphere Sciences, Meteorology http://proceedings.spiedigitallibrary.org/proceeding.aspx?articleid=2456202

  11. A linear model approach for ultrasonic inverse problems with attenuation and dispersion

    OpenAIRE

    Carcreff, Ewen; Bourguignon, Sébastien; Idier, Jérôme; Simon, Laurent

    2014-01-01

    Ultrasonic inverse problems such as spike train deconvolution, synthetic aperture focusing or tomography aim to reconstruct spatial properties of an object (discontinuities, delaminations, flaws, \\textit{etc.}) from noisy and incomplete measurements. They require an accurate description of the data acquisition process. Dealing with frequency-dependent attenuation and dispersion is therefore crucial since both phenomena modify the wave shape as the travel distance increases. In an inversion co...

  12. 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...

  13. Study of unsteady natural convection induced by absorption of radiation based on a three-waveband attenuation model

    International Nuclear Information System (INIS)

    The present study considers unsteady natural convection induced by the absorption of radiation for possible applications in the water quality management for the shallow regions of lakes and reservoirs. The direct absorption of the incoming radiation by the water body forms a stable thermal stratification, whilst residual radiation reaching the bottom bathymetry is re-emitted as a boundary flux, forming an unstable thermal stratification, which is a potential source for a Rayleigh-Benard type instability. The bottom boundary layer instability drives intermittent vertical convection in the form of rising plumes. The plume rise is, however, limited by the stable thermal stratification due to the direct absorption, which is controlled by the attenuation coefficient of water. The attenuation coefficient is therefore an important parameter in determining the plume rise and the associated vertical mixing. The wavelength dependency of the attenuation coefficient of water is accounted for by using a three-waveband model. A theoretical prediction is made for the plume rise distance, which represents the region of vigorous mixing. Two-dimensional numerical simulation provides verification for the accuracy of the theoretical prediction.

  14. 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.

  15. 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

  16. 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

  17. Flexible graphene based microwave attenuators.

    Science.gov (United States)

    Byun, Kisik; Ju Park, Yong; Ahn, Jong-Hyun; Min, Byung-Wook

    2015-02-01

    We demonstrate flexible 3 dB and 6 dB microwave attenuators using multilayer graphene grown by the chemical vapor deposition method. On the basis of the characterized results of multilayer graphene and graphene-Au ohmic contacts, the graphene attenuators are designed and measured. The flexible graphene-based attenuators have 3 dB and 6 dB attenuation with a return loss of less than -15 dB at higher than 5 GHz. The devices have shown durability in a bending cycling test of 100 times. The circuit model of the attenuator based on the characterized results matches the experimental results well. PMID:25590144

  18. Flexible graphene based microwave attenuators

    International Nuclear Information System (INIS)

    We demonstrate flexible 3 dB and 6 dB microwave attenuators using multilayer graphene grown by the chemical vapor deposition method. On the basis of the characterized results of multilayer graphene and graphene–Au ohmic contacts, the graphene attenuators are designed and measured. The flexible graphene-based attenuators have 3 dB and 6 dB attenuation with a return loss of less than −15 dB at higher than 5 GHz. The devices have shown durability in a bending cycling test of 100 times. The circuit model of the attenuator based on the characterized results matches the experimental results well. (paper)

  19. 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.

  20. Maximum Rain-Rate Evaluations in Aegean Archipelagos Hellas for Rain Attenuation Modeling at Microwave Frequencies

    Directory of Open Access Journals (Sweden)

    Evangelia Karagianni

    2016-04-01

    Full Text Available By utilizing meteorological data such as relative humidity, temperature, pressure, rain rate and precipitation duration at eight (8 stations in Aegean Archipelagos from six recent years (2007 – 2012, the effect of the weather on Electromagnetic wave propagation is studied. The EM wave propagation characteristics depend on atmospheric refractivity and consequently on Rain-Rate which vary in time and space randomly. Therefore the statistics of radio refractivity, Rain-Rate and related propagation effects are of main interest. This work investigates the maximum value of rain rate in monthly rainfall records, for a 5 min interval comparing it with different values of integration time as well as different percentages of time. The main goal is to determine the attenuation level for microwave links based on local rainfall data for various sites in Greece (L-zone, namely Aegean Archipelagos, with a view on improved accuracy as compared with more generic zone data available. A measurement of rain attenuation for a link in the S-band has been carried out and the data compared with prediction based on the standard ITU-R method.

  1. 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...

  2. 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

  3. Attenuation caused by infrequently updated covariates in survival analysis

    DEFF Research Database (Denmark)

    Andersen, Per Kragh; Liestøl, Knut

    Attenuation; Cox regression model; Measurement errors; Survival analysis; Time-dependent covariates......Attenuation; Cox regression model; Measurement errors; Survival analysis; Time-dependent covariates...

  4. 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

  5. Attrition of schistosomes in an irradiation-attenuated cercarial immunization model of Schistosoma mansoni

    International Nuclear Information System (INIS)

    The attrition of Schistosoma mansoni challenge worms was studied in irradiation-attenuated cercaria-immunized mice as a function of site and time. The peak recovery of schistosomula from the lungs of immunized mice was delayed 2 days in comparison with non-immunized controls. The difference between the peak recoveries of control and immunized mice accounted for about half of the final attrition observed at the 7-week adult worm stge. Hepatic-mesenteric vein worm recoveries obtained 10 to 42 days after challenge were reduced in most cases at least as much as the 49-day counts. Somewhat higher reductions were observed at 14 to 28 days than at 49 days, confirming the evidence of delayed migration obtained at the lung phase. These findings, coupled with histologic observations, indicate that at least half of the worm elimination attributable to immunization occurs 8 or more days after the challenge infection

  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. 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

  10. 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

  11. 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.

  12. [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

  13. PARP Inhibition Attenuates Histopathological Lesion in Ischemia/Reperfusion Renal Mouse Model after Cold Prolonged Ischemia

    Directory of Open Access Journals (Sweden)

    Raimundo M. G. del Moral

    2013-01-01

    Full Text Available We test the hypothesis that PARP inhibition can decrease acute tubular necrosis (ATN and other renal lesions related to prolonged cold ischemia/reperfusion (IR in kidneys preserved at 4°C in University of Wisconsin (UW solution. Material and Methods. We used 30 male Parp1+/+ wild-type and 15 male Parp10/0 knockout C57BL/6 mice. Fifteen of these wild-type mice were pretreated with 3,4-dihydro-5-[4-(1-piperidinylbutoxyl]-1(2H-isoquinolinone (DPQ at a concentration of 15 mg/kg body weight, used as PARP inhibitor. Subgroups of mice were established (A: IR 45 min/6 h; B: IR + 48 h in UW solution; and C: IR + 48 h in UW solution plus DPQ. We processed samples for morphological, immunohistochemical, ultrastructural, and western-blotting studies. Results. Prolonged cold ischemia time in UW solution increased PARP-1 expression and kidney injury. Preconditioning with PARP inhibitor DPQ plus DPQ supplementation in UW solution decreased PARP-1 nuclear expression in renal tubules and renal damage. Parp10/0 knockout mice were more resistant to IR-induced renal lesion. In conclusion, PARP inhibition attenuates ATN and other IR-related renal lesions in mouse kidneys under prolonged cold storage in UW solution. If confirmed, these data suggest that pharmacological manipulation of PARP activity may have salutary effects in cold-stored organs at transplantation.

  14. Pharmacologic attenuation of pelvic pain in a murine model of interstitial cystitis

    Directory of Open Access Journals (Sweden)

    Schaeffer Anthony J

    2009-11-01

    Full Text Available Abstract Background Interstitial cystitis/painful bladder syndrome (IC/PBS is a bladder disease that causes debilitating pelvic pain of unknown origin, and IC/PBS symptoms correlate with elevated bladder lamina propria mast cell counts. Similar to IC/PBS patients, pseudorabies virus (PRV infection in mice induces a neurogenic cystitis associated with bladder lamina propria mast cell accumulation and pelvic pain. We evaluated several drugs to determine the effectiveness of reducing PRV-induced pelvic pain. Methods Neurogenic cystitis was induced by the injection of Bartha's strain of PRV into the abductor caudalis dorsalis tail base muscle of female C57BL/6 mice. Therapeutic modulation of pelvic pain was assessed daily for five days using von Frey filament stimulation to the pelvic region to quantify tactile allodynia. Results Significant reduction of PRV-induced pelvic pain was observed for animals treated with antagonists of neurokinin receptor 1 (NK1R and histamine receptors. In contrast, the H1R antagonist hydroxyzine, proton pump inhibitors, a histamine receptor 3 agonist, and gabapentin had little or no effect on PRV-induced pelvic pain. Conclusion These data demonstrate that bladder-associated pelvic pain is attenuated by antagonists of NK1R and H2R. Therefore, NK1R and H2Rrepresent direct therapeutic targets for pain in IC/PBS and potentially other chronic pain conditions.

  15. Ultrasonic Attenuation in Zircaloy-4

    International Nuclear Information System (INIS)

    In this work the relationship between Zircaloy-4 grain size and ultrasonic attenuation behavior was studied for longitudinal waves in the frequency range of 10-90 MHz. The attenuation was analyzed as a function of frequency for samples with different mechanical and heat treatments having recrystallized and Widmanstatten structures with different grain size. The attenuation behavior was analyzed by different scattering models, depending on grain size, wavelength and frequency

  16. 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...... and biogeochemical transformation model of the discharge of a TCE plume into a stream, and to determine which parameters most strongly affect pollutant discharge concentrations. Here biological kinetics and the interaction with the soil matrix are implemented in PHREEQC. The ability of PHREEQC to deal...

  17. 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...

  18. 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

  19. 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.

  20. Water Extract of Dolichos lablab Attenuates Hepatic Lipid Accumulation in a Cellular Nonalcoholic Fatty Liver Disease Model.

    Science.gov (United States)

    Im, A-Rang; Kim, Yun Hee; Lee, Hye Won; Song, Kwang Hoon

    2016-05-01

    Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease that is rising in prevalence worldwide. Therapeutic strategies for patients with NAFLD are limited by a lack of effective drugs. In this report, we show that Dolichos lablab water extract (DLL-Ex) protects against free fatty acid (FFA)-induced lipid accumulation and attenuates expression of genes involved in lipid droplet accumulation in cellular NAFLD models. The hepatoprotective effects and underlying mechanism of DLL-Ex were assessed using an in vitro cellular model in which NAFLD was simulated by inducing excessive FFA influx into hepatocytes. HepG2 cells were treated with DLL-Ex and FFAs for 24 h, after which intracellular lipid content was observed by using Nile Red and Oil Red O staining. Quantitative real-time polymerase chain reaction was used to measure expression levels of genes related to FFA-mediated cellular energy depletion. Western blotting was used to measure protein levels of phosphorylated c-Jun N-terminal kinase, AMP-activated protein kinase alpha (AMPKα), and peroxisome proliferator-activated receptor γ coactivator 1 alpha. In HepG2 cells, DLL-Ex inhibited expression of CD36, which regulates fatty acid uptake, as well as BODIPY-labeled fatty acid uptake. Additionally, DLL-Ex significantly attenuated FFA-mediated cellular energy depletion and mitochondrial membrane depolarization. Furthermore, DLL-Ex enhanced phosphorylation of AMPK, indicating that AMPK is a critical regulator of DLL-Ex-mediated inhibition of hepatic lipid accumulation, possibly through its antioxidative effect. These results demonstrate that DLL-Ex exerts potent anti-NAFLD activity, suggesting that it could be a potential adjuvant treatment for patients with NAFLD. PMID:27152979

  1. Validation of a fluid dynamic model in a cold riser measuring catalyst concentration by gamma ray attenuation

    International Nuclear Information System (INIS)

    Simulated and experimental data of a cold riser were compared to validate a fluid dynamic model and a good agreement was found. The mathematical model described the fluid dynamic behavior of the riser in a FCC - fluid catalyst cracking type unit. In the circulating fluidized bed, air and catalyst were the components, the riser is a glass tube of 2.3 m long and 0.032 m in diameter. A computational CLP controls the unit operation and the maintenance of a steady state working regime. Measurements of the air flow, pressure drop and catalyst are continuously taken for monitoring the process variables. The solid concentration in circulating flow was determined by gamma attenuation measurements with a 241Am source and a NaI(Tl) detector coupled to a multichannel analyzer. Volumetric fraction measurements were taken using a Beer-Lambert based equation. Fluid dynamic models were selected from literature according to the basic equations formulated to describe the behavior of a solid-gas system. Three one-dimensional models were initially adopted and simulation tests with literature data were carried out. By means of a program written in the MATLAB software language the solution of the equations were obtained. One model was finally validated comparing the calculated data with experimental for the fluid dynamic variables: volumetric fraction (axial profile), solid and gas velocity and slip ratio between the two components. The results are given in graphics for the correlations of experimental and simulated data. The calculated values approximation was evaluated following the validation criterion of a maximum 10 % error. The validated model shows a good agreement for the experimental conditions: catalyst density of 2 - 5 kg/m3, gas velocity of 3 - 6 m/s and slip ratio values between 1 and 2. Under these conditions it can be stated the a one-dimensional model can satisfactorily describe the fluid dynamic behavior of a small diameter riser as in the cold model studied. (author)

  2. A non membrane-targeted human soluble CD59 attenuates choroidal neovascularization in a model of age related macular degeneration.

    Directory of Open Access Journals (Sweden)

    Siobhan M Cashman

    Full Text Available Age related macular degeneration (AMD is the most common cause of blindness amongst the elderly. Approximately 10% of AMD patients suffer from an advanced form of AMD characterized by choroidal neovascularization (CNV. Recent evidence implicates a significant role for complement in the pathogenesis of AMD. Activation of complement terminates in the incorporation of the membrane attack complex (MAC in biological membranes and subsequent cell lysis. Elevated levels of MAC have been documented on choroidal blood vessels and retinal pigment epithelium (RPE of AMD patients. CD59 is a naturally occurring membrane bound inhibitor of MAC formation. Previously we have shown that membrane bound human CD59 delivered to the RPE cells of mice via an adenovirus vector can protect those cells from human complement mediated lysis ex vivo. However, application of those observations to choroidal blood vessels are limited because protection from MAC- mediated lysis was restricted only to the cells originally transduced by the vector. Here we demonstrate that subretinal delivery of an adenovirus vector expressing a transgene for a soluble non-membrane binding form of human CD59 can attenuate the formation of laser-induced choroidal neovascularization and murine MAC formation in mice even when the region of vector delivery is distal to the site of laser induced CNV. Furthermore, this same recombinant transgene delivered to the intravitreal space of mice by an adeno-associated virus vector (AAV can also attenuate laser-induced CNV. To our knowledge, this is the first demonstration of a non-membrane targeting CD59 having biological potency in any animal model of disease in vivo. We propose that the above approaches warrant further exploration as potential approaches for alleviating complement mediated damage to ocular tissues in AMD.

  3. 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.

  4. 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

  5. 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

  6. 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)

  7. 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.

  8. 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

  9. 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 ...

  10. Modelling and measuring the atmospheric excess attenuation over flat terrain during night time conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ziemann, A.; Balogh, K.; Arnold, K. [Universitaet Leipzig fuer Meteorologie, Leipzig (Germany)

    2007-08-15

    The sound-ray model SMART (Sound propagation model of the atmosphere using ray-tracing) simulates the modified sound propagation due to sound-ray refraction in a stratified and moving atmosphere. The study was focussed on the influence of refraction on the sound propagation because this effect can result in a significant deviation from the straight-ray approximation used by the acoustic tomography and by the SODAR technique. For validation of the simulated data a measuring campaign was carried out over flat terrain in autumn 2004. The comparison of the modelled with measured data during clear night conditions with strong temperature inversion shows a satisfactory agreement, which leads to the conclusion that the important effect of refraction on outdoor sound propagation is reliably described by the model SMART. (orig.)

  11. Modelling of wave propagation and attenuation in the Osaka sedimentary basin, western Japan, during the 2013 Awaji Island earthquake

    Science.gov (United States)

    Asano, Kimiyuki; Sekiguchi, Haruko; Iwata, Tomotaka; Yoshimi, Masayuki; Hayashida, Takumi; Saomoto, Hidetaka; Horikawa, Haruo

    2016-03-01

    On 2013 April 13, an inland earthquake of Mw 5.8 occurred in Awaji Island, which forms the western boundary of the Osaka sedimentary basin in western Japan. The strong ground motion data were collected from more than 100 stations within the basin and it was found that in the Osaka Plain, the pseudo velocity response spectra at a period of around 6.5 s were significantly larger than at other stations of similar epicentral distance outside the basin. The ground motion lasted longer than 3 min in the Osaka Plain where its bedrock depth spatially varies from approximately 1 to 2 km. We modelled long-period (higher than 2 s) ground motions excited by this earthquake, using the finite difference method assuming a point source, to validate the present velocity structure model and to obtain better constraint of the attenuation factor of the sedimentary part of the basin. The effect of attenuation in the simulation was included in the form of Q(f) = Q0(f/f0), where Q0 at a reference frequency f0 was given by a function of the S-wave velocity, Q0 = αVS. We searched for appropriate Q0 values by changing α for a fixed value of f0 = 0.2 Hz. It was found that values of α from 0.2 to 0.5 fitted the observations reasonably well, but that the value of α = 0.3 performed best. Good agreement between the observed and simulated velocity waveforms was obtained for most stations within the Osaka Basin in terms of both amplitude and ground motion duration. However, underestimation of the pseudo velocity response spectra in the period range of 5-7 s was recognized in the central part of the Osaka Plain, which was caused by the inadequate modelling of later phases or wave packets in this period range observed approximately 2 min after the direct S-wave arrival. We analysed this observed later phase and concluded that it was a Love wave originating from the direction of the east coast of Awaji Island.

  12. 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...

  13. 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...... ultrasound pulse, which includes a maximum likelihood attenuation estimator, is derived. The results of this correspondence are of great importance for deconvolution and attenuation imaging in medical ultrasound...

  14. 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

  15. 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

  16. 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.

  17. 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

  18. Numerical Modeling of Tsunami Bore Attenuation and Extreme Hydrodynamic Impact Forces Using the SPH Method

    Science.gov (United States)

    Piche, Steffanie

    Understanding the impact of coastal forests on the propagation of rapidly advancing onshore tsunami bores is difficult due to complexity of this phenomenon and the large amount of parameters which must be considered. The research presented in the thesis focuses on understanding the protective effect of the coastal forest on the forces generated by the tsunami and its ability to reduce the propagation and velocity of the incoming tsunami bore. Concern for this method of protecting the coast from tsunamis is based on the effectiveness of the forest and its ability to withstand the impact forces caused by both the bore and the debris carried along by it. The devastation caused by the tsunami has been investigated in recent examples such as the 2011 Tohoku Tsunami in Japan and the Indian Ocean Tsunami which occurred in 2004. This research examines the reduction of the spatial extent of the tsunami bore inundation and runup due to the presence of the coastal forest, and attempts to quantify the impact forces induced by the tsunami bores and debris impact on the structures. This research work was performed using a numerical model based on the Smoothed Particle Hydrodynamics (SPH) method which is a single-phase three-dimensional model. The simulations performed in this study were separated into three sections. The first section focused on the reduction of the extent of the tsunami inundation and the magnitude of the bore velocity by the coastal forest. This section included the analysis of the hydrodynamic forces acting on the individual trees. The second section involved the numerical modeling of some of the physical laboratory experiments performed by researchers at the University of Ottawa, in cooperation with colleagues from the Ocean, Coastal and River Engineering Lab at the National Research Council, Ottawa, in an attempt to validate the movement and impact forces of floating driftwood on a column. The final section modeled the movement and impact of floating debris

  19. Shot-noise in resistive-diode mixers and the attenuator noise model

    Science.gov (United States)

    Kerr, A. R.

    1979-01-01

    The representation of a pumped exponential diode, operating as a mixer, by an equivalent lossy network, is reexamined. It is shown that the model is correct provided the network has ports for all sideband frequencies at which (real) power flow can occur between the diode and its embedding. The temperature of the equivalent network is eta/2 times the physical temperature of the diode. The model is valid only if the series resistance and nonlinear capacitance of the diode are negligible. Expressions are derived for the input and output noise temperature and the noise-temperature ratio of ideal mixers. Some common beliefs concerning noise-figure and noise-temperature ratio are shown to be incorrect.

  20. 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...

  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. Uranium ISR mine closure - general concepts and model-based simulation of natural attenuation for South-Australian mine sites

    International Nuclear Information System (INIS)

    Full text: Heathgate operates the Beverley uranium mine and is currently developing the nearby Beverley Four Mile project on behalf of a Quasar Resources-Alliance Resources joint venture. Both sites are located on the arid plane between the Flinders Rangers and Lake Frome, approximately 550 km North of Adelaide in South Australia. In-situ recovery (ISR) technology has been thoroughly adapted to the local conditions and is applied in a moderately acidic milieu, mobilizing uranium in the mineralized aquifers by oxidation with hydrogen peroxide mainly. In particular, the optimization of ISR technology under the local constraints resulted in a stringent minimization of waste water volumes from U processing (discharged to abandoned wellfields in isolated 'bathtub' aquifers) without producing radioactive solid waste. Natural attenuation (NA) is acknowledged as an appropriate control measure for ISR mines to avoid impacts on the aquifer environment surrounding the ISR wellfields. Data from the Beverley operation in a series of confined, nearly stagnant aquifers indicate that NA has considerably reduced the impact of ISR on groundwater and that a return approaching pre-mining conditions can be expected to occur in time. In order to demonstrate the effect of NA in post-mining scenarios for the new operation a comprehensive work program including: ' Groundwater flow modelling ' Geochemical laboratory test work ' Geochemical modelling (reactive transport) and ' Ongoing, iterative NA modelling validation and assessment has been established, also considering comprehensive mineralogical data from core investigations. In both the Beverley and the Beverley Four Mile deposits, uranium is found as coffinite in fine to coarse grained quartzose sands, whereas both ISR chemistry and NA are mainly defined by the most reactive minerals pyrite (reducing), calcite (neutralizing), kaolinite (neutralizing) as well as other silt/clay minerals with some ion-exchange capacities. A reactive

  3. 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.

  4. Esculetin Attenuates Th2 and Th17 Responses in an Ovalbumin-Induced Asthmatic Mouse Model.

    Science.gov (United States)

    Hongyan, Long

    2016-04-01

    The purpose of the current study was to investigate the anti-asthmatic effect of esculetin (ES) and explore its potential mechanism with a mouse model of allergic asthma. A total number of 50 mice were randomly assigned to five groups: control, model, dexamethasone (Dex, 2 mg/kg), and ES (20 mg/kg, 40 mg/kg). Mouse asthma model was developed with the sensitization and challenge of ovalbumin (OVA). The levels of IgE in serum, eosinophilia infiltration, Th2/Th17 cytokines, Th17 cell frequency, histological condition, and the protein expressions of RORγt, GATA3 were detected. Our study demonstrated that ES inhibited, OVA-induced eosinophil count, interleukin-4 (IL-4), IL-5, IL-13, and IL-17A levels were recovered in bronchoalveolar lavage fluid. Flow cytometry (FCM) studies revealed that ES substantially inhibited Th17 cells' percentage. Western blot study also indicated that ES downregulated RORγt and GATA3 expressions. Meanwhile, ES had beneficial effects on the histological alteration. These findings suggested that ES might effectively ameliorate the progression of asthma and could be used as a therapy for patients with allergic asthma. PMID:26797918

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

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

    Science.gov (United States)

    Pelisch, Nicolas; Dan, Takashi; Ichimura, Atsuhiko; Sekiguchi, Hiroki; Vaughan, Douglas E; van Ypersele de Strihou, Charles; Miyata, Toshio

    2015-01-01

    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. PMID:25915660

  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

    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

  8. 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

  9. Ebselen Attenuates Lung Injury in Experimental Model of Carrageenan-Induced Pleurisy in Rats.

    Science.gov (United States)

    Petronilho, Fabricia; Florentino, Drielly; Silvestre, Fernanda; Danielski, Lucineia Gainski; Nascimento, Diego Zapelini; Vieira, Andriele; Kanis, Luiz Alberto; Fortunato, Jucelia Jeremias; Badawy, Marwa; Barichello, Tatiana; Quevedo, Joao

    2015-08-01

    The study evaluates the role of Ebselen (Eb), an organoselenium compound in animal model of acute lung injury induced by carrageenan (CG). Wistar rats received saline or 2 % λ-carrageenan in the pleural cavity, and treatment with Eb (50 mg/kg intragastrically) or dexamethasone (Dx) (0.5 mg/kg intraperitoneal) after CG administration. After 4 h, rats were euthanized and the pleural exudate removed for analysis of the total cell count, total protein, lactate dehydrogenase, and nitrite/nitrate. Moreover, lung tissue were removed to verify the myeloperoxidase activity and oxidative damage. Eb showed anti-inflammatory activity by inhibiting leukocyte influx, myeloperoxidase activity, and nitrite/nitrate concentration. Eb presented with an anti-inflammatory activity similar to Dx and an antioxidant activity better than Dx. This study suggests that Eb plays an important role against the oxidative damage associated with anti-inflammatory activity in animal model of acute lung injury, proving to be similar or potentially more effective than Dx. PMID:25616904

  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. Tanshinone IIA Attenuates Renal Fibrosis after Acute Kidney Injury in a Mouse Model through Inhibition of Fibrocytes Recruitment

    Science.gov (United States)

    Jiang, Chunming; Shao, Qiuyuan; Jin, Bo; Zhang, Miao

    2015-01-01

    Acute kidney injury (AKI) is associated with an increased risk of developing advanced chronic kidney disease (CKD). Yet, effective interventions to prevent this conversion are unavailable for clinical practice. In this study, we examined the beneficial effects of Tanshinone IIA on renal fibrosis in a mouse model of folic acid induced AKI. We found that Tanshinone IIA treatment significantly attenuated the folic acid elicited kidney dysfunction on days 3, 14, and 28. This effect was concomitant with a much lessened accumulation of fibronectin and collagen in tubulointerstitium 28 days after folic acid injury, denoting an ameliorated renal fibrosis. The kidney protective and antifibrotic effect of Tanshinone IIA was likely attributable to an early inhibition of renal recruitment of fibrocytes positive for both CD45 and collagen I. Mechanistically, Tanshinone IIA treatment not only markedly diminished renal expression of chemoattractants for fibrocytes such as TGFβ1 and MCP-1, but also significantly reduced circulating fibrocytes at the acute phase of kidney injury. These data suggested that Tanshinone IIA might be a novel therapy for preventing progression of CKD after AKI. PMID:26885500

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

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    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.

  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. PMID:27040812

  14. Dependences of the attenuation and the backscatter coefficients on the frequency and the porosity in bovine trabecular bone: application of the binary mixture model

    International Nuclear Information System (INIS)

    The present study aims to investigate the dependences of the attenuation and the backscatter coefficients on the frequency and the porosity in bovine trabecular bone in vitro. The frequency dependent attenuation and backscatter coefficients were measured in 22 bovine femoral trabecular bone samples over a frequency range from 1.4 to 3.0 MHz by using a pair of transducers with a diameter of 12.7 mm and a center frequency of 2.25 MHz. The binary mixture model for ultrasonic scattering in trabecular bone, in which trabecular bone is assumed to be an isotropic binary mixture composed of a bone matrix and marrow, was applied to predict the measurements. The experimental results showed that the attenuation and the backscatter coefficients increased with increasing frequency from 1.4 to 3.0 MHz and decreased with increasing porosity from 66.9 to 91.5%. The predictions of the binary mixture model showed good agreements with the measurements, suggesting that scattering may be the dominant attenuation mechanism in dense bovine trabecular bone at frequencies from 1.4 to 3.0 MHz.

  15. Isotopic modelling of the significance of bacterial sulphate reduction for phenol attenuation in a contaminated aquifer

    Science.gov (United States)

    Spence, Michael J.; Bottrell, Simon H.; Thornton, Steven F.; Lerner, David N.

    2001-12-01

    A Triassic sandstone aquifer polluted with a mixture of phenolic hydrocarbons has been investigated by means of high-resolution groundwater sampling. Samples taken at depth intervals of 1 m have revealed the presence of a diving pollutant plume with a sharply defined upper margin. Concentrations of pollutant phenols exceed 4 g/l in the plume core, rendering it sterile but towards the diluted upper margin evidence for bacterial sulphate reduction (BSR) has been obtained. Groundwaters have been analysed for both δ34S-SO 4 and δ18O-SO 4. Two reservoirs have been identified with distinct sulphate-oxygen isotope ratios. Groundwater sulphate ( δ18O-SO 4=3-5‰) outside the plume shows a simple linear mixing trend with an isotopically uniform pollutant sulphate reservoir ( δ18O-SO 4=10-12‰) across the plume margin. The sulphur isotope ratios do not always obey a simple mixing relation, however, at one multilevel borehole, enrichment in 34SO 4 at the plume margin is inversely correlated with sulphate concentration. This and the presence of 34S-depleted dissolved sulphide indicate that enrichment in 34SO 4 is the result of bacterial sulphate reduction. δ34S analysis of trace hydrogen sulphide within the plume yielded an isotope enrichment factor ( ɛ) of -9.4‰ for present-day bacterial sulphate reduction. This value agrees with a long-term estimate (-9.9‰) obtained from a Rayleigh model of the sulphate reduction process. The model was also used to obtain an estimate of the pre-reduction sulphate concentration profile with depth. The difference between this and the present-day profiles then gave a mass balance for sulphate consumption. The organic carbon mineralisation that would account for this sulphate loss is shown to represent only 0.1‰ of the phenol concentration in this region of the plume. Hence, the contribution of bacterial sulphate reduction to biodegradation has thus far been small. The highest total phenolic concentration (TPC) at which there is

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

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    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. Thalidomide attenuates airway hyperresponsiveness and eosinophilic inflammation in a murine model of allergic asthma.

    Science.gov (United States)

    Asano, Toshiaki; Kume, Hiroaki; Taki, Fumitaka; Ito, Satoru; Hasegawa, Yoshinori

    2010-01-01

    Asthma is characterized by chronic eosinophilic inflammation and hyperresponsiveness of the airways. We hypothesized that thalidomide, which has numerous immunomodulatory properties, may have anti-inflammatory effects in allergic asthma. BALB/c mice sensitized and challenged with ovalbumin (OVA) were treated orally with thalidomide (30, 100, or 300 mg/kg) or a vehicle. When thalidomide was administered to OVA-challenged mice, the number of eosinophils in bronchoalveolar lavage fluid (BALF) was significantly decreased. The numbers of inflammatory cells other than eosinophils were not reduced by thalidomide. Thalidomide inhibited the elevated levels of interleukin-5 (IL-5) and tumor necrosis factor-alpha (TNF-alpha) in BALF by OVA challenges. Histological analysis of the lung revealed that both the infiltration of inflammatory cells and the hyperplasia of goblet cells were significantly suppressed by thalidomide treatment. Furthermore, thalidomide significantly inhibited the response to methacholine induced by OVA challenges. Taken together, thalidomide treatment decreased airway inflammation and hyperresponsiveness in a murine model of allergic asthma. These results might provide an opportunity for the development of novel therapeutics to treat severe asthma. PMID:20522972

  18. Modeling relaxation length and density of acacia mangium wood using gamma - ray attenuation technique

    International Nuclear Information System (INIS)

    Wood density measurement is related to the several factors that influence wood quality. In this paper, density, relaxation length and half-thickness value of eight ages, 3, 5, 7, 10, 11, 13 and 15 year-old of Acacia mangium wood were determined using gamma radiation from 137Cs source. Results show that Acacia mangium tree of age 3 year has the highest relaxation length of 83.33 cm and least density of 0.43 gcm-3, while the tree of age 15 year has the least Relaxation length of 28.56 cm and highest density of 0.76 gcm-3. Results also show that the 3 year-old Acacia mangium wood has the highest half thickness value of 57.75 cm and 15 year-old tree has the least half thickness value of 19.85 cm. Two mathematical models have been developed for the prediction of density, variation with relaxation length and half-thickness value of different age of tree. A good agreement (greater than 85% in most cases) was observed between the measured values and predicted ones. Very good linear correlation was found between measured density and the age of tree (R2 = 0.824), and between estimated density and Acacia mangium tree age (R2 = 0.952). (Author)

  19. Rosmarinic Acid Attenuates Airway Inflammation and Hyperresponsiveness in a Murine Model of Asthma.

    Science.gov (United States)

    Liang, Zhengmin; Xu, Yangfeng; Wen, Xuemei; Nie, Haiying; Hu, Tingjun; Yang, Xiaofeng; Chu, Xiao; Yang, Jian; Deng, Xuming; He, Jiakang

    2016-01-01

    Rosmarinic acid (RA) has numerous pharmacologic effects, including anti-oxidant, anti-inflammatory, and analgesic effects. This study aimed to evaluate the preventive activity of RA in a murine model of asthma and to investigate its possible molecular mechanisms. Female BALB/c mice sensitized and challenged with ovalbumin (Ova) were pretreated with RA (5, 10 or 20 mg/kg) at 1 h before Ova challenge. The results demonstrated that RA markedly inhibited increases in inflammatory cells and Th2 cytokines in the bronchoalveolar lavage fluid (BALF), significantly reduced the total IgE and Ova-specific IgE concentrations, and greatly ameliorated airway hyperresponsiveness (AHR) compared with the control Ova-induced mice. Histological analyses showed that RA substantially decreased the number of inflammatory cells and mucus hypersecretion in the airway. In addition, our results suggested that the protective effects of RA might be mediated by the suppression of ERK, JNK and p38 phosphorylation and activation of nuclear factor-κB (NF-κB). Furthermore, RA pretreatment resulted in a noticeable reduction in AMCase, CCL11, CCR3, Ym2 and E-selectin mRNA expression in lung tissues. These findings suggest that RA may effectively delay the progression of airway inflammation. PMID:27304950

  20. Rosmarinic Acid Attenuates Airway Inflammation and Hyperresponsiveness in a Murine Model of Asthma

    Directory of Open Access Journals (Sweden)

    Zhengmin Liang

    2016-06-01

    Full Text Available Rosmarinic acid (RA has numerous pharmacologic effects, including anti-oxidant, anti-inflammatory, and analgesic effects. This study aimed to evaluate the preventive activity of RA in a murine model of asthma and to investigate its possible molecular mechanisms. Female BALB/c mice sensitized and challenged with ovalbumin (Ova were pretreated with RA (5, 10 or 20 mg/kg at 1 h before Ova challenge. The results demonstrated that RA markedly inhibited increases in inflammatory cells and Th2 cytokines in the bronchoalveolar lavage fluid (BALF, significantly reduced the total IgE and Ova-specific IgE concentrations, and greatly ameliorated airway hyperresponsiveness (AHR compared with the control Ova-induced mice. Histological analyses showed that RA substantially decreased the number of inflammatory cells and mucus hypersecretion in the airway. In addition, our results suggested that the protective effects of RA might be mediated by the suppression of ERK, JNK and p38 phosphorylation and activation of nuclear factor-κB (NF-κB. Furthermore, RA pretreatment resulted in a noticeable reduction in AMCase, CCL11, CCR3, Ym2 and E-selectin mRNA expression in lung tissues. These findings suggest that RA may effectively delay the progression of airway inflammation.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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

  7. Rotary antenna attenuator

    Science.gov (United States)

    Dickinson, R. M.; Hardy, J. C.

    1969-01-01

    Radio frequency attenuator, having negligible insertion loss at minimum attenuation, can be used for making precise antenna gain measurements. It is small in size compared to a rotary-vane attenuator.

  8. The Implications of ACTS Technology on the Requirements of Rain Attenuation Modeling for Communication System Specification and Analysis at 30/20 GHz and Beyond

    Science.gov (United States)

    Manning, Robert M.

    1996-01-01

    The advent of the use of the Ka-Band for space communications, coupled with the introduction of digital modulation techniques as well as multiple-beam methodology for satellites, has deemed it necessary to reassess the plethora of rain attenuation prediction models in use. The Advanced Communication Technology Satellite (ACTS) Project, undertaken by the National Aeronautics and Space Administration in 1983, offered such challenges to rain attenuation prediction modeling. Up to 1983, no such single modeling formalism existed that could fill such requirements. Not even the work done by the NASA Propagation Experimenters (NAPEX) Group had envisioned such requirements, so no dynamic Ka-Band data existed from which one could draw conclusions. In this paper, the basic rudiments of what has become to be known as the 'ACTS Rain Attenuation Prediction Model' will be presented. The concept of rain fade mitigation control availability will be introduced. A new evaluation is then presented for the performance of satellite communication systems, in particular, those to be operating within the Ka-Band and above, that will necessarily employ some type of dynamic rain fade mitigation procedure.

  9. Uranium ISR Mine Closure — General Concepts and Model-Based Simulation of Natural Attenuation for South-Australian Mine Sites

    International Nuclear Information System (INIS)

    Heathgate has demonstrated the effect of natural attenuation (NA) in post in-situ recovery (ISR) aquifer regions during the operation of the Beverley mine since 2001. Enhanced natural attenuation (ENA) has been considered as the key component of the mine closure concept for the new Beverley Four Mile (BFM) project, complemented by an extensive monitoring program. Data from batch and column tests for BFM core samples was used to calibrate a reactive transport model, whose application in conjunction with the hydrological modelling of the BFM aquifer has shown that NA will result in the restoration of the aquifer in time. ENA within a staged mine development program under the site-specific circumstances is discussed. (author)

  10. Protective effects of geraniol (a monoterpene) in a diabetic neuropathy rat model: attenuation of behavioral impairments and biochemical perturbations.

    Science.gov (United States)

    Prasad, Sathya N; Muralidhara

    2014-09-01

    Involvement of oxidative stress, inflammatory response, and mitochondrial dysfunction in the development of diabetic neuropathy (DN) is well appreciated. The present study examines the potential of geraniol (GE), a well-known phytoconstituent commonly found in lemon, spices, rose oil, etc., to attenuate DN-associated oxidative/nitrosative stress by employing a streptozotocin (STZ) diabetic rat model. STZ-induced diabetic rats provided with oral supplements of GE (100 mg/kg bw/day, 8 weeks) exhibited significant improvement in tail-flick latency (sensory function) and the narrow beam test (motor function). Terminally, elevated levels of oxidative markers (reactive oxygen species, malondialdehyde, hydroperoxides) in cytosol of the sciatic nerve (SN) and in selected regions of the brain of diabetic rats were markedly reduced by GE supplements. Furthermore, GE significantly diminished the levels of protein carbonyls (a measure of protein oxidation) and nitrites in diabetic rats. In addition, in mitochondria, GE supplements restored the activities of enzymes, such as complexes I-III, succinate dehydrogenase, and citrate synthase, in brain regions of diabetic rats, with a concomitant reduction in the levels of oxidative markers. GE significantly lowered the enhanced cytosolic calcium levels and acetylcholinesterase activity in the SN and the brain regions of diabetic rats. Depleted dopamine levels evident in the SN and the cortex/striatum among diabetic rats were restored by GE. From our data, we hypothesize that GE may be a promising therapeutic candidate in the management of DN in humans. Further understanding of the molecular mechanisms of its neuromodulatory effects is essential in order to exploit its therapeutic efficacy. PMID:24752916

  11. EBM84 attenuates airway inflammation and mucus hypersecretion in an ovalbumin-induced murine model of asthma.

    Science.gov (United States)

    Shin, In Sik; Lee, Mee Young; Jeon, Woo Young; Shin, Na Ra; Seo, Chang Seob; Ha, Hyekyung

    2013-04-01

    EBM84 is a traditional herbal medicine and a combination of extracts obtained from Pinellia ternata and Zingiber officinale. It is traditionally used to treat vomiting, nausea, sputum and gastrointestinal disorders, and functions is an effective expectorant. In this study, we evaluated the protective effects of EBM84 on asthmatic responses, particularly mucus hypersecretion in an ovalbumin (OVA)-induced murine model of asthma. We also analyzed EBM84 composition using high performance liquid chromatography. Animals were sensitized on days 0 and 14 via intraperitoneal injection using 20 µg OVA. On days 21, 22 and 23 after initial sensitization, the mice received an airway challenge with OVA (1% w/v in PBS) for 1 h using an ultrasonic nebulizer (NE-U12). EBM84 was administered by gavage to the mice at doses of 16.9, 33.8 and 67.5 mg/kg once daily from days 18 to 23. EBM84 administration significantly lowered elevated levels of interleukin (IL)-4, IL-13, eotaxin and immunoglobulin (Ig)E in the bronchoalveolar lavage fluid or plasma. Airway inflammation and mucus hypersecretion were attenuated following EBM84 administration. EBM84 also inhibited the overexpression of mucin 5AC (MUC5AC) induced by OVA challenge in lung tissue. This result was consistent with the immunohistochemistry results. Our results indicate that EBM84 effectively inhibited airway inflammation and mucus hypersecretion via the downregulation of T helper 2 (Th2) cytokines, which reduced MUC5AC expression. Therefore, EBM84 has potential as a useful medicine for the treatment of allergic asthma. PMID:23403738

  12. 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.

  13. 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...

  14. 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.

  15. Selective inducible nitric oxide synthase inhibition attenuates organ dysfunction and elevated endothelin levels in LPS-induced DIC model rats.

    Science.gov (United States)

    Asakura, H; Asamura, R; Ontachi, Y; Hayashi, T; Yamazaki, M; Morishita, E; Miyamoto, K-I; Nakao, S

    2005-05-01

    We examined the role of nitric oxide (NO) produced by an inducible isoform of NO synthase (iNOS) using N[6]-(iminoethyl)-lysine (L-NIL), a selective iNOS inhibitor, in the rat model of lipopolysaccharide (LPS)-induced disseminated intravascular coagulation (DIC) and investigated changes in organ function, plasma levels of NOX (metabolites of NO) and endothelin. We induced experimental DIC by the sustained infusion of 30 mg kg(-1) LPS for 4 h via the tail vein. We then investigated the effect of L-NIL (6 mg kg(-1), from - 0.5 to 4 h) on LPS-induced DIC. Blood was withdrawn at 4 and 8 h, and all four groups (LPS with or without L-NIL at 4 and 8 h) consisted of eight rats. Three of the animals in the 8-h LPS group died, and we examined blood samples from five rats in this group. None of the other rats died. The LPS-induced elevation of creatinine, alanine aminotransferase, glomerular fibrin deposition and plasminogen activator inhibitor was significantly suppressed by L-NIL coadministration, although L-NIL did not affect the platelet count, fibrinogen concentration or the level of thrombin-antithrombin complex. Moreover, plasma levels of the D-dimer that reflect the lysis of cross-linked fibrin were significantly increased by L-NIL coadministration in the LPS-induced DIC model. Plasma levels of NOX and endothelin were obviously increased by LPS infusion. However, both levels were significantly suppressed in the LPS + L-NIL group, when compared with the LPS group. Although mean arterial pressure (MAP) was significantly decreased between 2 and 8 h compared with the control in the LPS group, this depression was significantly attenuated in the LPS + L-NIL group. Our results suggest that NO induced by iNOS contributes to hypotension (depressed MAP), the progression of hepatic and renal dysfunction, microthrombus deposition and elevated endothelin levels in the rat model of LPS-induced DIC. PMID:15869603

  16. 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

  17. 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.

  18. Intranigral administration of substance P receptor antagonist attenuated levodopa-induced dyskinesia in a rat model of Parkinson's disease.

    Science.gov (United States)

    Yang, Xinxin; Zhao, Hui; Shi, Hongjuan; Wang, Xiaoying; Zhang, Shenyang; Zhang, Zunsheng; Zu, Jie; Zhang, Wei; Shen, Xia; Cui, Guiyun; Hua, Fang

    2015-09-01

    Levodopa (L-dopa) remains the most effective drug in the treatment of Parkinson's disease (PD). However, L-dopa-induced dyskinesia (LID) has hindered its use for PD patients. The mechanisms of LID are not fully understood. Substance P (SP) receptor antagonist has been shown to reduce parkinsonism in animal models of PD, and ameliorate LID in PD rats. But the concrete mechanism is not fully understood. To address this issue, we produced a rat model of PD using 6-hydroxydompamine (6-OHDA) injections, and valid PD rats were intranigrally administrated with different doses of SP receptor antagonist LY303870 (5 nmol/day, 10 nmol/day and 20 nmol/day) following L-dopa (6 mg/kg/day, i.p.) plus benserazide (12 mg/kg/day, i.p.) for 23 days. We found that nigral SP levels were increased on days 3, 7 and 14 and decreased on day 21 after 6-hydroxydompamine lesions. But nigral SP levels kept increasing after repeated L-dopa administration in PD rats. Intranigral administration of low and moderate LY303870 reduced abnormal involuntary movements (AIMs) while improving motor deficits in PD rats treated with L-dopa plus benserazide. Microdialysis revealed that LY303870 (10 nmol/day) treatment attenuated the increase of striatal dopamine and the reduction of γ-aminobutyric acid in ventromedial thalamus of PD rats primed with L-dopa. Additionally, LY303870 (10 nmol/day) treatment prior to L-dopa administration reduced the phosphorylated levels of dopamine- and cyclic adenosine monophosphate-regulated phosphoprotein of 32 kDa at Thr 34 and extracellular signal-regulated kinases 1/2 as well as the levels of activity-regulated cytoskeleton-associated protein and Penk in L-dopa-primed PD rats. Taken together, these data showed that low and moderate SP receptor antagonists LY303870 could ameliorate LID via neurokinin 1 receptor without affecting therapeutic effect of L-dopa. PMID:26001615

  19. Effect of Dosage and Vaccination Route on Transmission of a Live Attenuated Mycoplasma gallesepticum Vaccine: A Broiler Model

    Science.gov (United States)

    Mycoplasma gallisepticum (MG) is an economically significant pathogen of poultry species and among the table egg sector of the poultry industry, live attenuated strains of MG are commonly utilized to limit production losses associated with MG-induced disease. The vaccine, however, may be problemati...

  20. 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.

  1. 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.

  2. DC attenuation meter

    Science.gov (United States)

    Hargrove, Douglas L.

    2004-09-14

    A portable, hand-held meter used to measure direct current (DC) attenuation in low impedance electrical signal cables and signal attenuators. A DC voltage is applied to the signal input of the cable and feedback to the control circuit through the signal cable and attenuators. The control circuit adjusts the applied voltage to the cable until the feedback voltage equals the reference voltage. The "units" of applied voltage required at the cable input is the system attenuation value of the cable and attenuators, which makes this meter unique. The meter may be used to calibrate data signal cables, attenuators, and cable-attenuator assemblies.

  3. 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.

  4. 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

  5. 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.

  6. 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...

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

    OpenAIRE

    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. Vi...

  8. 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...

  9. 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 ...

  10. 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

  11. 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.

  12. Pressure surge attenuator

    Science.gov (United States)

    Christie, Alan M.; Snyder, Kurt I.

    1985-01-01

    A pressure surge attenuation system for pipes having a fluted region opposite crushable metal foam. As adapted for nuclear reactor vessels and heads, crushable metal foam is disposed to attenuate pressure surges.

  13. Highly accurate stability-preserving optimization of the Zener viscoelastic model, with application to wave propagation in the presence of strong attenuation

    Science.gov (United States)

    Blanc, Émilie; Komatitsch, Dimitri; Chaljub, Emmanuel; Lombard, Bruno; Xie, Zhinan

    2016-04-01

    This paper concerns the numerical modelling of time-domain mechanical waves in viscoelastic media based on a generalized Zener model. To do so, classically in the literature relaxation mechanisms are introduced, resulting in a set of the so-called memory variables and thus in large computational arrays that need to be stored. A challenge is thus to accurately mimic a given attenuation law using a minimal set of relaxation mechanisms. For this purpose, we replace the classical linear approach of Emmerich & Korn with a nonlinear optimization approach with constraints of positivity. We show that this technique is more accurate than the linear approach. Moreover, it ensures that physically meaningful relaxation times that always honour the constraint of decay of total energy with time are obtained. As a result, these relaxation times can always be used in a stable way in a modelling algorithm, even in the case of very strong attenuation for which the classical linear approach may provide some negative and thus unusable coefficients.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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

  19. Catastrophic breakdown of the Caves model for quantum noise in some phase-insensitive linear amplifiers or attenuators based on atomic systems

    Science.gov (United States)

    Zhou, Minchuan; Zhou, Zifan; Shahriar, Selim M.

    2016-03-01

    When considering the effect of quantum noise (QN) in a phase-insensitive linear amplifier or attenuator, it is customary to use the single-channel Caves model (SC-CM). Although this model is valid in simple situations, such as the presence of a beam splitter, it is not necessarily valid when a system with many degrees of freedom is involved. In order to address this issue, we consider in this paper various atomic transitions corresponding to amplification or attenuation using the master-equation- (ME-) based approach to model the QN and to compare the results with the SC-CM. For a four-level system that consists of a transition producing a broad gain peak and a transition producing an absorption dip, which results in perfect transparency at the center, we observe a catastrophic breakdown of the SC-CM. We also show that for a general two-level atomic system, the SC-CM does not apply, except in the limiting case when only either amplification or attenuation exists. A special case where the two models predict the same result is a Λ-type three-level electromagnetically induced transparency (EIT) system in which the QN at zero detuning vanishes while the system is in the dark state. We also study an optically pumped five-level gain EIT system which has a perfect transparency dip superimposed on a gain profile and yields the negative dispersion suitable for use in enhancing the sensitivity-bandwidth product of an interferometric gravitational wave detector. In this case, we find that, for some set of parameters, the QN is vanishingly small at the center of the dip, and the SC-CM agrees closely with the ME model. However, we also find that for some other set of parameters, the SC-SM model disagrees strongly with the ME model. All these cases illustrate a wide range of variations in the degree of disagreement between the predictions of the SC-CM and the ME approaches.

  20. 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

  1. Joint Interpretation of Multi-parameter Tomographic Models (e.g., Seismic P and S Velocity, Anisotropy, Attenuation): A Neural Network Approach

    Science.gov (United States)

    Bauer, K.

    2008-12-01

    Seismic tomography can provide a set of models which represent different properties of the same target region. A typical example is the development of coincident P and S velocity cross sections from travel time tomography. Other applications may include additional determination of attenuation and anisotropy. Self-organizing maps (SOM) are powerful neural network techniques to classify and interpret multi-attribute data sets. The coincident tomographic images are translated to a set of data vectors in order to train a Kohonen layer. The total gradient of the model vectors is determined for the trained SOM and a watershed segmentation algorithm is used to visualize and map the lithological clusters with well-defined seismic signatures. The principal working flow is demonstrated for a synthetic data set. Further examples include P and S velocity tomography across a sub-volcanic ring complex in Namibia, and combination of velocity, anisotropy, and attenuation tomography to characterize gas hydrate bearing sediments in the Mackenzie Delta, NW Canada.

  2. 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.

  3. 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.

  4. 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 ...

  5. 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.

  6. 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

  7. 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.

  8. 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.

  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. 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.

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

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    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.

  12. 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

  13. 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.

  14. 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.

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

    Science.gov (United States)

    Modi, Khushbu K; Roy, Avik; Brahmachari, Saurabh; Rangasamy, Suresh B; Pahan, Kalipada

    2015-01-01

    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. PMID:26102198

  16. 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

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Ultrasound fields in an attenuating medium

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Gandhi,, D; O'Brien,, W.D., Jr.

    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 the...... spatial impulse response, whereas the field cannot readily be found for an attenuating medium. In this paper we present a simulation program capable of calculating the field in a homogeneous attenuating medium. The program splits the aperture into rectangles and uses a far-field approximation for each of...... the rectangles and sums all contributions to arrive at the spatial impulse response for the aperture and field point. This approach makes it possible to model all transducer apertures, and the program can readily calculate the emitted, pulse-echo and continuous wave field. Attenuation is included by...

  20. 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.

  1. Application of the Polynomial-Based Least Squares and Total Least Squares Models for the Attenuated Total Reflection Fourier Transform Infrared Spectra of Binary Mixtures of Hydroxyl Compounds.

    Science.gov (United States)

    Shan, Peng; Peng, Silong; Zhao, Yuhui; Tang, Liang

    2016-03-01

    An analysis of binary mixtures of hydroxyl compound by Attenuated Total Reflection Fourier transform infrared spectroscopy (ATR FT-IR) and classical least squares (CLS) yield large model error due to the presence of unmodeled components such as H-bonded components. To accommodate these spectral variations, polynomial-based least squares (LSP) and polynomial-based total least squares (TLSP) are proposed to capture the nonlinear absorbance-concentration relationship. LSP is based on assuming that only absorbance noise exists; while TLSP takes both absorbance noise and concentration noise into consideration. In addition, based on different solving strategy, two optimization algorithms (limited-memory Broyden-Fletcher-Goldfarb-Shanno (LBFGS) algorithm and Levenberg-Marquardt (LM) algorithm) are combined with TLSP and then two different TLSP versions (termed as TLSP-LBFGS and TLSP-LM) are formed. The optimum order of each nonlinear model is determined by cross-validation. Comparison and analyses of the four models are made from two aspects: absorbance prediction and concentration prediction. The results for water-ethanol solution and ethanol-ethyl lactate solution show that LSP, TLSP-LBFGS, and TLSP-LM can, for both absorbance prediction and concentration prediction, obtain smaller root mean square error of prediction than CLS. Additionally, they can also greatly enhance the accuracy of estimated pure component spectra. However, from the view of concentration prediction, the Wilcoxon signed rank test shows that there is no statistically significant difference between each nonlinear model and CLS. PMID:26810185

  2. 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).

  3. 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....

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

    International Nuclear Information System (INIS)

    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

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

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2010-05-01

    Full Text Available Abstract Background 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. Methods 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. Results 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. Conclusions 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. 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

  7. 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

  8. 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

  9. 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.

  10. 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

  11. 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

  12. Attenuation Tomography of the Upper Mantle

    Science.gov (United States)

    Adenis, A.; Debayle, E.; Ricard, Y. R.

    2014-12-01

    We present a 3-D model of surface wave attenuation in the upper mantle. The model is constrained by a large data set of fundamental and higher Rayleigh mode observations. This data set consists of about 1,800,000 attenuation curves measured in the period range 50-300s by Debayle and Ricard (2012). A careful selection allows us to reject data for which measurements are likely biased by the poor knowledge of the scalar seismic moment or by a ray propagation too close to a node of the source radiation pattern. For each epicenter-station path, elastic focusing effects due to seismic heterogeneities are corrected using DR2012 and the data are turned into log(1/Q). The selected data are then combined in a tomographic inversion using the non-linear least square formalism of Tarantola and Valette (1982). The obtained attenuation maps are in agreement with the surface tectonic for periods and modes sensitive to the top 200km of the upper mantle. Low attenuation regions correlate with continental shields while high attenuation regions are located beneath young oceanic regions. The attenuation pattern becomes more homogeneous at depths greater than 200 km and the maps are dominated by a high quality factor signature beneath slabs. We will discuss the similarities and differences between the tomographies of seismic velocities and of attenuations.

  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. 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.

  15. RADIO FREQUENCY ATTENUATOR

    Science.gov (United States)

    Giordano, S.

    1963-11-12

    A high peak power level r-f attenuator that is readily and easily insertable along a coaxial cable having an inner conductor and an outer annular conductor without breaking the ends thereof is presented. Spaced first and second flares in the outer conductor face each other with a slidable cylindrical outer conductor portion therebetween. Dielectric means, such as water, contact the cable between the flares to attenuate the radio-frequency energy received thereby. The cylindrical outer conductor portion is slidable to adjust the voltage standing wave ratio to a low level, and one of the flares is slidable to adjust the attenuation level. An integral dielectric container is also provided. (AFC)

  16. A statistical rain attenuation prediction model with application to the advanced communication technology satellite project. 3: A stochastic rain fade control algorithm for satellite link power via non linear Markow filtering theory

    Science.gov (United States)

    Manning, Robert M.

    1991-01-01

    The dynamic and composite nature of propagation impairments that are incurred on Earth-space communications links at frequencies in and above 30/20 GHz Ka band, i.e., rain attenuation, cloud and/or clear air scintillation, etc., combined with the need to counter such degradations after the small link margins have been exceeded, necessitate the use of dynamic statistical identification and prediction processing of the fading signal in order to optimally estimate and predict the levels of each of the deleterious attenuation components. Such requirements are being met in NASA's Advanced Communications Technology Satellite (ACTS) Project by the implementation of optimal processing schemes derived through the use of the Rain Attenuation Prediction Model and nonlinear Markov filtering theory.

  17. 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.

  18. 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.

  19. 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; Hadamitzky, Martin; Pankratova, Stanislava; Wendt, Hannes; Bock, Elisabeth; Berezin, Vladimir; Potschka, Heidrun

    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...

  20. 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.

  1. 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

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

    Science.gov (United States)

    Arteaga-Velázquez, J. C.; Apel, W. D.; Bekk, K.; Bertaina, M.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; Di Pierro, F.; Doll, P.; Engel, R.; Engler, J.; Fuchs, B.; Fuhrmann, D.; Gherghel-Lascu, A.; Gils, H. J.; Glasstetter, R.; Grupen, C.; Haungs, A.; Heck, D.; Hörandel, J. R.; Huber, D.; Huege, T.; Kampert, K.-H.; Kang, D.; Klages, H. O.; Link, K.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Oehlschläger, J.; Ostapchenko, S.; Palmieri, N.; Petcu, M.; Pierog, T.; Rebel, H.; Roth, M.; Schieler, H.; Schoo, S.; Schröder, F. G.; Sima, O.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Weindl, A.; Wochele, J.; Zabierowski, J.

    2015-08-01

    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.

  3. PARP inhibition attenuates early brain injury through NF-κB/MMP-9 pathway in a rat model of subarachnoid hemorrhage.

    Science.gov (United States)

    Chen, Ting; Wang, Wei; Li, Jian-Ru; Xu, Hang-Zhe; Peng, Yu-Cong; Fan, Lin-Feng; Yan, Feng; Gu, Chi; Wang, Lin; Chen, Gao

    2016-08-01

    Poly (ADP-ribose) polymerases (PARPs) play an important role in a range of neurological disorders, however, the role of PARP in early brain injury after subarachnoid hemorrhage (SAH) remains unclear. This study was designed to explore the role and the potential mechanisms of PARP in early brain injury after SAH. Eighty-nine male SD rats were randomly divided into the Sham group, SAH+Vehicle group and SAH+PARP inhibitor (PJ34) group. An endovascular perforation model was used to induce SAH in rats. PJ34 (10mg/kg) or vehicle (0.9% NaCl) was intraperitoneally administered at 5min and 8h after SAH induction. Mortality, SAH grades, neurological function, evans blue extravasation, brain edema, immunofluorescence staining and western blotting were performed. PJ34 reduced BBB permeability and brain edema, improved neurological function and attenuated neuronal cell death in the rat model of SAH. Moreover, PJ34 inhibited the nuclear translocation of NF-κB, decreased the expression of the proinflammatory cytokines IL-1ß, IL-6 and TNF-α, reduced the expression of MMP-9, prevented the degradation of tight junction proteins, and decreased microglia activation. These data indicated that PARP inhibition through PJ34 might be an important therapeutic drug for SAH. PMID:27157545

  4. Evaluation of the moisture prediction capability of near-infrared and attenuated total reflectance fourier transform infrared spectroscopy using superdisintegrants as model compounds.

    Science.gov (United States)

    Uppaluri, Sai G; Bompelliwar, Sai K; Johnson, Paul R; Gupta, Mali R; Al-Achi, Antoine; Stagner, William C; Haware, Rahul V

    2014-12-01

    The superdisintegrants (SDs) moisture content measurement by near-infrared (NIR) spectroscopy and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy has been evaluated against thermogravimetric analysis as a reference method. SDs with varying moisture content were used to build calibration and independent model verification data sets. Calibration models were developed based on the water-specific NIR and ATR-FTIR spectral regions using partial least-square regression methods. Because of the NIR water low molar absorptivity, NIR spectroscopy handled higher moisture content (∼81%, w/w) than ATR-FTIR (∼25%, w/w). A two-way ANOVA test was performed to compare R(2) values obtained from measured and predicted moisture content (5%-25%, w/w) of SDs. No statistically significant difference was observed between the predictability of NIR and ATR-FTIR methods (p = 0.3504). However, the interactions between the two independent variables, SDs, and analytical methods were statistically significant (p = 0.0002), indicating that the predictability of the analytical method is material dependent. Thus, it would be important to recognize this highly dependent material and analytical method interaction when using NIR moisture analysis in process analytical technology to analyze and control critical quality and performance attributes of raw materials during processing with the goal of ensuring final product quality attributes. PMID:25332106

  5. 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.

  6. 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

  7. Attenuator And Conditioner

    Science.gov (United States)

    Anderson, Gene R.; Armendariz, Marcelino G.; Carson, Richard F.; Bryan, Robert P.; Duckett, III, Edwin B.; Kemme, Shanalyn Adair; McCormick, Frederick B.; Peterson, David W.

    2006-04-04

    An apparatus and method of attenuating and/or conditioning optical energy for an optical transmitter, receiver or transceiver module is disclosed. An apparatus for attenuating the optical output of an optoelectronic connector including: a mounting surface; an array of optoelectronic devices having at least a first end; an array of optical elements having at least a first end; the first end of the array of optical elements optically aligned with the first end of the array of optoelectronic devices; an optical path extending from the first end of the array of optoelectronic devices and ending at a second end of the array of optical elements; and an attenuator in the optical path for attenuating the optical energy emitted from the array of optoelectronic devices. Alternatively, a conditioner may be adapted in the optical path for conditioning the optical energy emitted from the array of optoelectronic devices.

  8. 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 ...

  9. 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...

  10. 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

  11. 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.

  12. Neuropeptide deficient mice have attenuated nociceptive, vascular, and inflammatory changes in a tibia fracture model of complex regional pain syndrome

    OpenAIRE

    Guo Tian-Zhi; Wei Tzuping; Shi Xiaoyou; Li Wen-Wu; Hou Saiyun; Wang Liping; Tsujikawa Kazutake; Rice Kenner C; Cheng Kejun; Clark David J; Kingery Wade S

    2012-01-01

    Abstract Background Distal limb fracture in man can induce a complex regional pain syndrome (CRPS) with pain, warmth, edema, and cutaneous inflammation. In the present study substance P (SP, Tac1−/−) and CGRP receptor (RAMP1−/−) deficient mice were used to investigate the contribution of neuropeptide signaling to CRPS-like changes in a tibia fracture mouse model. Wildtype, Tac1−/−, and RAMP1−/− mice underwent tibia fracture and casting for 3 weeks, then the cast was removed and hindpaw mechan...

  13. 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

    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...... and biogeochemical transformation model of the discharge of a TCE plume into a stream, and to determine which parameters most strongly affect pollutant discharge concentrations. Here biological kinetics and the interaction with the soil matrix are implemented in PHREEQC. The ability of PHREEQC to deal...

  14. 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

  15. 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

  16. 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

  17. 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

  18. Attenuated ventricular β-adrenergic response and reduced repolarization reserve in a rabbit model of chronic heart failure

    DEFF Research Database (Denmark)

    Nissen, Jakob Dahl; Thomsen, Morten Bækgaard; Bentzen, Bo Hjorth; Diness, Jonas Goldin; Diness, Thomas Goldin; Jespersen, Thomas; Grunnet, Morten

    2012-01-01

    Animal models of pacing-induced heart failure (HF) are often associated with high acute mortality secondary to high pacing frequencies. The present study therefore exploits lower-frequency left ventricular pacing (300 beats per minute) in rabbits for 11 weeks to produce chronic HF with low acute...... mortality but profound structural, functional, and electrical remodeling and compare with nonpaced controls. Pacing increased heart weight/body weight ratio and decreased left ventricular fractional shortening in tachypaced only. Electrocardiogram recordings during sinus rhythm revealed QTc prolongation in...... paced animals. Ventricular arrhythmias or sudden death was not observed. Isoproterenol increased heart rate similarly in both groups but showed a blunted QT-shortening effect in tachypaced rabbits compared with controls. Langendorff experiments revealed significant monophasic action potential duration...

  19. P2X7 Receptor Antagonism Attenuates the Intermittent Hypoxia-induced Spatial Deficits in a Murine Model of Sleep Apnea Via Inhibiting Neuroinflammation and Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Yan Deng

    2015-01-01

    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.

  20. 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

  1. 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

  2. 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

  3. 7-nitroindazole attenuates 6-hydroxydopamine-induced spatial learning deficits and dopamine neuron loss in a presymptomatic animal model of Parkinson's disease.

    Science.gov (United States)

    Haik, Kristi L; Shear, Deborah A; Hargrove, Chad; Patton, Jared; Mazei-Robison, Michelle; Sandstrom, Michael I; Dunbar, Gary L

    2008-04-01

    Parkinson's disease (PD) is a neurodegenerative disorder in which loss of dopaminergic (DA) neurons (>50%) in the substantia nigra (SN) precedes most of the overt motor symptoms, making early diagnosis and treatment interventions difficult. Because PD has been associated with free radicals generated by nitric oxide, this study tested whether treatments of 7-nitroindazole (7NI), a nitric-oxide-synthase inhibitor, could reduce cognitive deficits that often emerge before overt motor symptoms in a presymptomatic rat model of PD. Rats were given intraperitoneal injections of 50 mg/kg 7NI (or vehicle) just before receiving bilateral, intrastriatal injections of the DA-toxin, 6-hydroxydopamine (6-OHDA). The rats were then given a battery of motor tasks, and their learning ability was assessed using a spatial reversal task in a water-T maze. Results indicate that 7NI treatments attenuate 6-OHDA-induced spatial learning deficits and protect against DA cell loss in the SN, suggesting that 7NI may have potential as an early, presymptomatic pharmacotherapy for PD. PMID:18489022

  4. Generation of an attenuated Salmonella-delivery strains expressing adhesin and toxin antigens for progressive atrophic rhinitis, and evaluation of its immune responses in a murine model.

    Science.gov (United States)

    Byeon, Hoyeon; Hur, Jin; Kim, Bo Ram; Lee, John Hwa

    2014-09-01

    An expression/secretion plasmid containing genes encoding the FimA, CP39, PtfA, ToxA and F1P2 antigens associated with porcine pneumonic pasteurellosis and progressive atrophic rhinitis (PAR) was constructed and harbored in an attenuated Salmonella Typhimurium, which was used as the vaccine candidate. The immune responses induced by this delivery strain were investigated in a murine model. Each antigen secreted from the delivery strain was confirmed by Western blot analysis. Thirty BALB/c mice were divided equally into two groups; group A were intranasally inoculated with the mixture of the five delivery strains, and group B were inoculated with sterile PBS. In group A, all antigen-specific serum IgG were significantly increased compared to those of group B from the 2nd week post-inoculation (WPI) till the 8th WPI. All antigen-specific mucosal IgA in group A were also significantly greater than those of group B. In addition, the significant splenic lymphocyte proliferative responses, the elevations of CD3(+)CD4(+), CD3(+)CD8(+) and B-cell populations, and the induction of IFN-γ expression in group A were observed. In conclusion, the mixture of five delivery strains expressing specific antigen for these diseases was found to be capable of inducing significant humoral and cellular immune responses. PMID:25045826

  5. 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.

  6. 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

  7. 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

  8. Systemic pregabalin attenuates facial hypersensitivity and noxious stimulus-evoked release of glutamate in medullary dorsal horn in a rodent model of trigeminal neuropathic pain.

    Science.gov (United States)

    Kumar, Naresh; Cherkas, Pavel S; Varathan, Vidya; Miyamoto, Makiko; Chiang, Chen Yu; Dostrovsky, Jonathan O; Sessle, Barry J; Coderre, Terence J

    2013-05-01

    Pregabalin is effective in treating many neuropathic pain conditions. However, the mechanisms of its analgesic effects remain poorly understood. The aim of the present study was to determine whether pregabalin suppresses facial mechanical hypersensitivity and evoked glutamate release in the medullary dorsal horn (MDH) in a rodent model of trigeminal neuropathic pain. Nociceptive mechanical sensitivity was assessed pre-operatively, and then post-operatively 1h following pregabalin or vehicle (saline) treatment on post-operative days 2 and 5 following infraorbital nerve transection (IONX). In addition, an in vivo microdialysis probe was inserted into the exposed medulla post-operatively and dialysate samples were collected. Glutamate release was then evoked by mustard oil (MO) application to the tooth pulp, and the effects of pregabalin or vehicle were examined on the MDH glutamate release. Glutamate concentrations in the dialysated samples were determined by HPLC, and data analyzed by ANOVA. IONX animals (but not control animals) showed facial mechanical hypersensitivity for several days post-operatively. In addition, tooth pulp stimulation with MO evoked a transient release of glutamate in the MDH of IONX animals. Compared to vehicle, administration of pregabalin significantly attenuated the facial mechanical hypersensitivity as well as the MO-evoked glutamate release in MDH. This study provides evidence in support of recent findings pointing to the usefulness of pregabalin in the treatment of orofacial neuropathic pain. PMID:23454190

  9. Modelling natural attenuation of heavy-metal groundwater contamination in the Selebi-Phikwe mining area, Botswana

    Science.gov (United States)

    Schwartz, M. O.; Kgomanyane, J.

    2008-04-01

    Seepage from a tailings dam is the major source of groundwater pollution in the Selebi-Phikwe area, where mining of sulphidic nickel-copper-cobalt ore started in 1973 and will continue until 2014. The seepage water has a pH in the range of 1.7-2.8 and is strongly enriched in SO4 2- (5,680 g/L) and heavy metals (6,230 μg/L Ni, 1,860 μg/L Cu and 410 μg/L Co). The fracture aquifer affected by pollution from the dam exhibits a remarkable capacity of heavy-metal sorption. Most of the Ni, Cu and Co is scavenged at less than 500 m distance downgradient from the polluting source, whereas SO4 2- is not immobilized significantly. The heavy-metal sorption process is assumed to be due to surface complexation, which is supported by a relatively high groundwater pH (in the range of 6.2-7.8 at >200 m distance from the tailings dam). The objective of this study is to demonstrate that the sorption process can be incorporated into a realistic three-dimensional reactive-transport groundwater model that is implicitly charge-balanced. The simulations are performed with the PHAST1.2 program, which is based on the HST3D flow and transport code and the hydrochemical PHREEQC2.12 code.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. The increased potassium intake improves cognitive performance and attenuates histopathological markers in a model of Alzheimer's disease.

    Science.gov (United States)

    Cisternas, Pedro; Lindsay, Carolina B; Salazar, Paulina; Silva-Alvarez, Carmen; Retamales, Rocio M; Serrano, Felipe G; Vio, Carlos P; Inestrosa, Nibaldo C

    2015-12-01

    Alzheimer's disease (AD) is a neurodegenerative disorder characterized by hallmarks that include an accumulation of amyloid-β peptide (Aβ), inflammation, oxidative stress and synaptic dysfunction, which lead to a decrease in cognitive function. To date, the onset and progression of AD have been associated with pathologies such as hypertension and diabetes. Hypertension, a disease with a high incidence worldwide, is characterized by a chronic increase in blood pressure. Interestingly, this disease has a close relationship to the eating behavior of patients because high Na(+) intake is a significant risk factor for hypertension. In fact, a decrease in Na(+) consumption, along with an increase in K(+) intake, is a primary non-pharmacological approach to preventing hypertension. In the present work, we examined whether an increase in K(+) intake affects the expression of certain neuropathological markers or the cognitive performance of a murine model of AD. We observed that an increase in K(+) intake leads to a change in the aggregation pattern of the Aβ peptide, a partial decrease in some epitopes of tau phosphorylation and improvement in the cognitive performance. The recovery in cognitive performance was correlated with a significant improvement in the generation of long-term potentiation. We also observed a decrease in markers related to inflammation and oxidative stress such as glial fibrillary acidic protein (GFAP), interleukin 6 (IL-6) and 4-hydroxynonenal (4-HNE). Together, our data support the idea that changes in diet, such as an increase in K(+) intake, may be important in the prevention of AD onset as a non-pharmacological therapy. PMID:26391254

  15. 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

  16. 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

  17. Sustained Neural Stem Cell-Based Intraocular Delivery of CNTF Attenuates Photoreceptor Loss in the nclf Mouse Model of Neuronal Ceroid Lipofuscinosis.

    Directory of Open Access Journals (Sweden)

    Wanda Jankowiak

    Full Text Available A sustained intraocular administration of neurotrophic factors is among the strategies aimed at establishing treatments for currently untreatable degenerative retinal disorders. In the present study we have analyzed the neuroprotective effects of a continuous neural stem (NS cell-based intraocular delivery of ciliary neurotrophic factor (CNTF on photoreceptor cells in the nclf mouse, an animal model of the neurodegenerative lysosomal storage disorder variant late infantile neuronal ceroid lipofuscinosis (vLINCL. To this aim, we genetically modified adherently cultivated NS cells with a polycistronic lentiviral vector encoding a secretable variant of CNTF together with a Venus reporter gene (CNTF-NS cells. NS cells for control experiments (control-NS cells were modified with a vector encoding the reporter gene tdTomato. Clonal CNTF-NS and control-NS cell lines were established using fluorescent activated cell sorting and intravitreally grafted into 14 days old nclf mice at the onset of retinal degeneration. The grafted cells preferentially differentiated into astrocytes that were attached to the posterior side of the lenses and the vitreal side of the retinas and stably expressed the transgenes for at least six weeks, the latest post-transplantation time point analyzed. Integration of donor cells into host retinas, ongoing proliferation of grafted cells or adverse effects of the donor cells on the morphology of the host eyes were not observed. Quantitative analyses of host retinas two, four and six weeks after cell transplantation revealed the presence of significantly more photoreceptor cells in eyes with grafted CNTF-NS cells than in eyes with grafted control-NS cells. This is the first demonstration that a continuous intraocular administration of a neurotrophic factor attenuates retinal degeneration in an animal model of neuronal ceroid lipofuscinosis.

  18. Modelling the fate of six common pharmaceuticals in a small stream: quantification of attenuation and retention in different stream-specific environments

    Science.gov (United States)

    Riml, Joakim; Wörman, Anders; Kunkel, Uwe; Radke, Michael

    2013-04-01

    Detection of pharmaceutical residues in streaming waters is common in urbanized areas. Although the occurrence and source of these micropollutants is known, their behavior in these aquatic ecosystems is still only partly understood. Specifically, quantitative information of biogeochemical processes in stream-specific environments where predominant reactions occur is often missing. In an attempt to address this knowledge gap, we performed simultaneous tracer tests in Säva Brook, Sweden, with bezafibrate, clofibric acid, diclofenac, ibuprofen, metoprolol and naproxen, as well as with the more inert solutes uranine and Rhodamine WT. The breakthrough curves at five successive sampling stations along a 16 km long stream reach were evaluated using a coupled physical-biogeochemical model framework containing surface water transport together with a representation of transient storage in slow/immobile zones of the stream. The multi-tracer experiment opens for decoupling of hydrological and biogeochemical contribution to the fate, and by linking impact and sensitivity analyses to relative significance of model parameters the most important processes for each contaminant were elucidated. Specifically for Säva Brook, the proposed methodology revealed that the pharmaceutical-contaminated stream water remained in the storage zones for times corresponding to 5-25% of the flow time of the stream. Furthermore, the results indicate a great variability in terms of predominant biogeochemical processes between the different contaminants. Rapid reactions occurring in the transient storage zone attenuated both ibuprofen and clofibric acid, and we conclude that a major degradation pathway for these contaminants was biodegradation in the hyporheic zone. In contrast, bezafibrate, metoprolol, and naproxen were mainly affected by sorption both in the storage zone and the main channel, while diclofenac displayed negligible effects of biogeochemical reactions.

  19. Statistical analysis of accurate prediction of local atmospheric optical attenuation with a new model according to weather together with beam wandering compensation system: a season-wise experimental investigation

    Science.gov (United States)

    Arockia Bazil Raj, A.; Padmavathi, S.

    2016-07-01

    Atmospheric parameters strongly affect the performance of Free Space Optical Communication (FSOC) system when the optical wave is propagating through the inhomogeneous turbulent medium. Developing a model to get an accurate prediction of optical attenuation according to meteorological parameters becomes significant to understand the behaviour of FSOC channel during different seasons. A dedicated free space optical link experimental set-up is developed for the range of 0.5 km at an altitude of 15.25 m. The diurnal profile of received power and corresponding meteorological parameters are continuously measured using the developed optoelectronic assembly and weather station, respectively, and stored in a data logging computer. Measured meteorological parameters (as input factors) and optical attenuation (as response factor) of size [177147 × 4] are used for linear regression analysis and to design the mathematical model that is more suitable to predict the atmospheric optical attenuation at our test field. A model that exhibits the R2 value of 98.76% and average percentage deviation of 1.59% is considered for practical implementation. The prediction accuracy of the proposed model is investigated along with the comparative results obtained from some of the existing models in terms of Root Mean Square Error (RMSE) during different local seasons in one-year period. The average RMSE value of 0.043-dB/km is obtained in the longer range dynamic of meteorological parameters variations.

  20. Radiofrequency attenuator and method

    Science.gov (United States)

    Warner, Benjamin P.; McCleskey, T. Mark; Burrell, Anthony K.; Agrawal, Anoop; Hall, Simon B.

    2009-11-10

    Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3 C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

  1. 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.

  2. 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

  3. 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

  4. Rebamipide Attenuates Mandibular Condylar Degeneration in a Murine Model of TMJ-OA by Mediating a Chondroprotective Effect and by Downregulating RANKL-Mediated Osteoclastogenesis

    Science.gov (United States)

    Izawa, Takashi; Mori, Hiroki; Shinohara, Tekehiro; Mino-Oka, Akiko; Hutami, Islamy Rahma; Iwasa, Akihiko; Tanaka, Eiji

    2016-01-01

    Temporomandibular joint osteoarthritis (TMJ-OA) is characterized by progressive degradation of cartilage and changes in subchondral bone. It is also one of the most serious subgroups of temporomandibular disorders. Rebamipide is a gastroprotective agent that is currently used for the treatment of gastritis and gastric ulcers. It scavenges reactive oxygen radicals and has exhibited anti-inflammatory potential. The aim of this study was to investigate the impact of rebamipide both in vivo and in vitro on the development of cartilage degeneration and osteoclast activity in an experimental murine model of TMJ-OA, and to explore its mode of action. Oral administration of rebamipide (0.6 mg/kg and 6 mg/kg) was initiated 24 h after TMJ-OA was induced, and was maintained daily for four weeks. Rebamipide treatment was found to attenuate cartilage degeneration, to reduce the number of apoptotic cells, and to decrease the expression levels of matrix metalloproteinase-13 (MMP-13) and inducible nitric oxide synthase (iNOS) in TMJ-OA cartilage in a dose-dependent manner. Rebamipide also suppressed the activation of transcription factors (e.g., NF-κB, NFATc1) and mitogen-activated protein kinases (MAPK) by receptor activator of nuclear factor kappa-B ligand (RANKL) to inhibit the differentiation of osteoclastic precursors, and disrupted the formation of actin rings in mature osteoclasts. Together, these results demonstrate the inhibitory effects of rebamipide on cartilage degradation in experimentally induced TMJ-OA. Furthermore, suppression of oxidative damage, restoration of extracellular matrix homeostasis of articular chondrocytes, and reduced subchondral bone loss as a result of blocked osteoclast activation suggest that rebamipide is a potential therapeutic strategy for TMJ-OA. PMID:27123995

  5. 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

  6. Pressure surge attenuator

    International Nuclear Information System (INIS)

    A pressure surge attenuation arrangement comprises crushable metal foam disposed adjacent regions adapted to be expanded by a pressure surge. In a pipe system such region consists of a thin walled inner pipe surrounded by a housing with crushable metal foam disposed in the space between the housing and the inner pipe. (author)

  7. Tritium Attenuation by Distillation

    International Nuclear Information System (INIS)

    The objective of this study was to determine how a 100 Area distillation system could be used to reduce to a satisfactory low value the tritium content of the dilute moderator produced in the 100 Area stills, and whether such a tritium attenuator would have sufficient capacity to process all this material before it is sent to the 400 Area for reprocessing

  8. Natural attenuation of herbicides

    DEFF Research Database (Denmark)

    Tuxen, Nina; Højberg, Anker Lajer; Broholm, Mette Martina;

    2002-01-01

    A field injection experiment in a sandy, aerobic aquifer showed that two phenoxy acids MCPP (mecoprop) and dichlorprop were degraded within I in downgradient of the injection wells after an apparent lag period. The plume development and microbial measurements indicated that microbial growth gover...... observations may be important for application of natural attenuation as a remedy in field scale systems....

  9. 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

  10. 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 ...

  11. EFFECTS OF RAIN ATTENUATION ON SATELLITE COMMUNICATION LINK

    Directory of Open Access Journals (Sweden)

    G. N. Ezeh

    2014-06-01

    Full Text Available Rain attenuation is a major challenge to microwave satellite communication especially at frequencies above 10 GHz, causing unavailability of signals most of the time. Rain attenuation predictions have become one of the vital considerations while setting up a satellite communication link. In this study, rain attenuation models, cumulative distribution curves and other analytical tools for successful prediction of rain attenuation are presented. A three year Rain rate data was obtained from the Nigeria Meteorological Agency (NIMET database in addition to experimental data. Of the three prediction models used in the study, Ajayi model gave the range of values closest to the experimental data. A correctional factor was determined as 1.0988 and used to modify the Ajayi model. This modification to Ajayi’s model enabled its rain attenuation values conform more closely to the experimental result.

  12. A compact rotary vane attenuator

    Science.gov (United States)

    Nixon, D. L.; Otosh, T. Y.; Stelzried, C. T.

    1969-01-01

    Rotary vane attenuator, when used as a front end attenuator, introduces an insertion loss that is proportional to the angle of rotation. New technique allows the construction of a shortened compact unit suitable for most installations.

  13. Photon attenuation by intensifying screens

    International Nuclear Information System (INIS)

    The photon attenuation by intensifying screens of different chemical composition has been determined. The attenuation of photons between 20 keV and 120 keV was measured by use of a multi-channel analyzer and a broad bremsstrahlung distribution. The attenuation by the intensifying screens was hereby determined simultaneously at many different monoenergetic photon energies. Experimentally determined attenuations were found to agree well with attenuation calculated from mass attenuation coefficients. The attenuation by the screens was also determined at various bremsstrahlung distributions, simulating those occurring behind the patient in various diagnostic X-ray examinations. The high attenuation in some of the intensifying screens form the basis for an analysis of the construction of asymmetric screen pairs. Single screen systems are suggested as a favourable alternative to thick screen pair systems. (Author)

  14. 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.

  15. 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.

  16. Enabling photon counting detectors with dynamic attenuators

    Science.gov (United States)

    Hsieh, Scott S.; Pelc, Norbert J.

    2014-03-01

    Photon-counting x-ray detectors (PCXDs) are being investigated as a replacement for conventional x-ray detectors because they promise several advantages, including better dose efficiency, higher resolution and spectral imaging. However, many of these advantages disappear when the x-ray flux incident on the detector is too high. We recently proposed a dynamic, piecewise-linear attenuator (or beam shaping filter) that can control the flux incident on the detector. This can restrict the operating range of the PCXD to keep the incident count rate below a given limit. We simulated a system with the piecewise-linear attenuator and a PCXD using raw data generated from forward projected DICOM files. We investigated the classic paralyzable and nonparalyzable PCXD as well as a weighted average of the two, with the weights chosen to mimic an existing PCXD (Taguchi et al, Med Phys 2011). The dynamic attenuator has small synergistic benefits with the nonparalyzable detector and large synergistic benefits with the paralyzable detector. Real PCXDs operate somewhere between these models, and the weighted average model still shows large benefits from the dynamic attenuator. We conclude that dynamic attenuators can reduce the count rate performance necessary for adopting PCXDs.

  17. Downhole pressure attenuation apparatus

    International Nuclear Information System (INIS)

    This patent describes a process for preventing damage to tool strings and other downhole equipment in a well caused by pressures produced during detonation of one or more downhole explosive devices. It comprises adding to a tool string at least one pressure attenuating apparatus for attenuating the peak pressure wave and quasi-static pressure pulse produced by the explosive devices, the pressure attenuating apparatus including an initially closed relief vent including tubing means supporting a plurality of charge port assemblies each including an explosive filled shaped charge and a prestressed disc, the shaped charges interconnected by a detonating cord, the amount of explosive in each shaped charge being sufficient to rupture its associated disc without damaging surrounding tubular bodies in the well, and a vent chamber defined by the tubing means and providing a liquid free volume, and opening the relief vent substantially contemporaneously with downhole explosive device detonation by detonating the shaped charges to rupture the discs of the charge port assemblies

  18. Selective p38α mitogen-activated protein kinase inhibitor attenuates lung inflammation and fibrosis in IL-13 transgenic mouse model of asthma

    Directory of Open Access Journals (Sweden)

    Jing Ying Ma

    2008-11-01

    Full Text Available Jing Ying Ma1, Satyanarayana Medicherla1, Irene Kerr, Ruban Mangadu, Andrew A Protter, Linda S Higgins1Scios Inc, Fremont, CA, USA 1Jing Ying Ma and Satyanarayana Medicherla contributed equally to this workAbstract: p38 Mitogen-activated protein kinase (MAPK plays a critical role in the activation of inflammatory cells. We investigated the anti-inflammatory effects of a p38α-selective MAPK inhibitor (SD-282 in a mouse transgenic (CC10:IL-13 asthma model. The CC-10-driven over-expression of IL-13 in the mouse lung/airway has been shown to result in a remarkable phenotype recatitulating many features of asthma and characterized by eosinophilic and mononuclear inflammation, with airway epithelial cell hypertrophy, mucus cell metaplasia, the hyperproduction of neutral and acidic mucus, the deposition of Charcot–Leyden-like crystal, and airway sub-epitheilial fibrosis. Here we show how activated p38 MAPK can be observed in the lungs at the onset of asthma ie, around 8 weeks of age in both female and male mice. We also show that administration of a p38α MAPK selective inhibitor, SD-282 at 30 or 90 mg/kg, twice a day for a period of four weeks beginning at the onset of asthma, significantly reduced the inflammation (p < 0.001; hyperplasia of airway epithelium (p < 0.05; goblet cell metaplasia and mucus hypersecretion (p < 0.001 and reduced lung remodeling and fibrosis (p < 0.01, alleviating the severity of lung damage as measured by a composite score (p < 0.05. Furthermore, SD-282 significantly reduced activated p38 MAPK in the lymphocytes and epithelial cells (p < 0.001. Simultaneously, identical studies were conducted with an anti-fibrotic TGFβR1 kinase inhibitor (SD-208 which demonstrated anti-fibrotic but not anti-inflammatory properties. These findings suggest that the p38α-selective MAPK inhibitor may have dual therapeutic potential in attenuating both the inflammatory component and the fibrotic component of asthma and other Th2

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. The Coriolis attenuation problem in 235U

    International Nuclear Information System (INIS)

    A new version of the particle-rotor model, featuring diagonalization of a state-dependent pairing force and the full recoil term, has been applied to 235U. A significant improvement is obtained in the description of the Coriolis coupled K=5/2, 7/2 and 9/2 rotational bands. No ad hoc Coriolis attenuation factors are used. (orig.)

  4. The attenuation of the periodic table

    International Nuclear Information System (INIS)

    Unique among models of nuclear structure, the face-centered-cubic (FCC) lattice model predicts the attenuation of the periodic table at Z < 110 and the impossibility of superheavy nuclei. The total binding energies of superheavy nuclei in the FCC model (109 < Z < 127) were calculated on the basis of parameters obtained from a least-squares best-fit for 914 nuclei (Z < 99). No indication of increased stability is found for any of the transuranic elements

  5. Lattice Boltzmann simulations of attenuation-driven acoustic streaming

    International Nuclear Information System (INIS)

    We show that lattice Boltzmann simulations can be used to model the attenuation-driven acoustic streaming produced by a travelling wave. Comparisons are made to analytical results and to the streaming pattern produced by an imposed body force approximating the Reynolds stresses. We predict the streaming patterns around a porous material in an attenuating acoustic field

  6. Novel monohydroxamate drugs attenuate myocardial reperfusion-induced arrhythmias

    DEFF Research Database (Denmark)

    Collis, C S; Rice-Evans, C; Davies, Michael Jonathan

    1996-01-01

    The novel monohydroxamates N-methyl hexanoylhydroxamic acid, N-methyl acetohydroxamic acid, and N-methyl butyrohydroxamic acid have antioxidant and iron chelating properties. They attenuated reperfusion-induced contractile dysfunction following long periods of ischaemia (50 min) in the isolated rat......, particularly N-methyl acetohydroxamic acid, attenuate reperfusion-induced arrhythmias in this model when introduced during the ischaemic period....

  7. Divergent Immunomodulating Effects of Probiotics on T Cell Responses to Oral Attenuated Human Rotavirus Vaccine and Virulent Human Rotavirus Infection in a Neonatal Gnotobiotic Piglet Disease Model

    OpenAIRE

    Chattha, Kuldeep S; Vlasova, Anastasia N.; Kandasamy, Sukumar; Rajashekara, Gireesh; Saif, Linda J.

    2013-01-01

    Rotaviruses (RVs) are a leading cause of childhood diarrhea. Current oral vaccines are not effective in impoverished countries where the vaccine is needed most. Therefore, alternative affordable strategies are urgently needed. Probiotics can alleviate diarrhea in children and enhance specific systemic and mucosal Ab responses, but the T cell responses are undefined. In this study, we elucidated the T cell and cytokine responses to attenuated human RV (AttHRV) and virulent human RV (HRV) in gn...

  8. 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

  9. Study of RF Signal Attenuation of Human Heart

    OpenAIRE

    Kedar Nath Sahu; Challa Dhanunjaya Naidu; M. Satyam; K. Jaya Sankar

    2015-01-01

    A study of ultrawideband pulse propagation modeling through human body for all frequencies from 0.1 to 10.5 GHz is presented. Reflection coefficient and signal attenuation are computed from the model considering the variation of heart dimension with respect to time unlike a fixed dimension of heart used in earlier models. The performance of cardiac activity is studied from the change of signal attenuation. This estimation may help in the design of a noninvasive diagnostic system using ultrawi...

  10. Chopping-Wheel Optical Attenuator

    Science.gov (United States)

    Leviton, Douglas B.

    1988-01-01

    Star-shaped rotating chopping wheel provides adjustable time-averaged attenuation of narrow beam of light without changing length of optical path or spectral distribution of light. Duty cycle or attenuation factor of chopped beam controlled by adjusting radius at which beam intersects wheel. Attenuation factor independent of wavelength. Useful in systems in which chopping frequency above frequency-response limits of photodetectors receiving chopped light. Used in systems using synchronous detection with lock-in amplifiers.

  11. Comparison of hyperspectral measurements of the attenuation and scattering coefficients spectra with modeling results in the north-eastern Baltic Sea

    Science.gov (United States)

    Sipelgas, Liis; Raudsepp, Urmas

    2015-11-01

    The spectral variations in the attenuation and scattering coefficients measured with a hyperspectral ac-spectra (Wetlabs) instrument were analyzed from a dataset collected in the vicinity of commercial harbors on the Estonian coast of the Gulf of Finland, Baltic Sea. In total, the measured TSM concentration varied from 0.4 to 30 mg L-1 and the concentration of Chl a varied from values below the detection limit (0.05) to 23 mg m-3. The reliability of the power law describing the particle attenuation cp (λ) and scattering bp(λ) coefficients was evaluated by means of a determination coefficient (R2). The power law described the particle attenuation spectra with high accuracy (R2 > 0.67), giving the dataset an average cp (λ) slope of 1.3. In the case of particle scattering coefficients, the power law did not represent the whole dataset. Depending on a particular spectrum, the R2 varied from 0 to 1.0 and the slope varied from 1.15 to -0.56. Decomposition of bp(λ) into dominant modes using principal component analyses resulted in the first principal mode accounting for the power law dependence of bp(λ), i.e. the "mineral-type" spectrum, and the second and third mode representing the characteristic bp(λ) of dominant algal particles, i.e. the "algae-type" spectrum. From our dataset we estimated that if Chl a concentration is above 10 mg m-3 or below 5 mg m-3 then most likely the "algae-type" or the "mineral-type" spectrum is dominant, respectively. There was strong linear relationship (R2 > 0.92) between TSM concentration and cp(555) and bp(555),irrespective of the dominant shape of the particle scattering spectra. The estimated TSM-specific attenuation and scattering coefficients at 555 nm were 0.8 m2 g-1 and 0.68 m2 g-1, respectively. Corresponding values for water samples with a dominant "mineral-type" spectrum were 0.85 m2 g-1 and 0.73 m2 g-1, respectively and for water samples with a dominant "algae-type" spectrum were 0.64 m2 g-1 and 0.52 m2 g-1, respectively.

  12. LINE-ABOVE-GROUND ATTENUATOR

    Science.gov (United States)

    Wilds, R.B.; Ames, J.R.

    1957-09-24

    The line-above-ground attenuator provides a continuously variable microwave attenuator for a coaxial line that is capable of high attenuation and low insertion loss. The device consists of a short section of the line-above- ground plane type transmission lime, a pair of identical rectangular slabs of lossy material like polytron, whose longitudinal axes are parallel to and indentically spaced away from either side of the line, and a geared mechanism to adjust amd maintain this spaced relationship. This device permits optimum fineness and accuracy of attenuator control which heretofore has been difficult to achieve.

  13. Fiber optic attenuator

    Science.gov (United States)

    Buzzetti, Mike F. (Inventor)

    1994-01-01

    A fiber optic attenuator of the invention is a mandrel structure through which a bundle of optical fibers is wrapped around in a complete circle. The mandrel structure includes a flexible cylindrical sheath through which the bundle passes. A set screw on the mandrel structure impacts one side of the sheath against two posts on the opposite side of the sheath. By rotating the screw, the sheath is deformed to extend partially between the two posts, bending the fiber optic bundle to a small radius controlled by rotating the set screw. Bending the fiber optic bundle to a small radius causes light in each optical fiber to be lost in the cladding, the amount depending upon the radius about which the bundle is bent.

  14. 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.

  15. 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.

  16. 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...

  17. Adjustable Optical-Fiber Attenuator

    Science.gov (United States)

    Buzzetti, Mike F.

    1994-01-01

    Adjustable fiber-optic attenuator utilizes bending loss to reduce strength of light transmitted along it. Attenuator functions without introducing measurable back-reflection or insertion loss. Relatively insensitive to vibration and changes in temperature. Potential applications include cable television, telephone networks, other signal-distribution networks, and laboratory instrumentation.

  18. Electrically tunable hot-silicon terahertz attenuator

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Minjie [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Vajtai, Robert; Ajayan, Pulickel M. [Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Kono, Junichiro, E-mail: kono@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005 (United States)

    2014-10-06

    We have developed a continuously tunable, broadband terahertz attenuator with a transmission tuning range greater than 10{sup 3}. Attenuation tuning is achieved electrically, by simply changing the DC voltage applied to a heating wire attached to a bulk silicon wafer, which controls its temperature between room temperature and ∼550 K, with the corresponding free-carrier density adjusted between ∼10{sup 11 }cm{sup −3} and ∼10{sup 17 }cm{sup −3}. This “hot-silicon”-based terahertz attenuator works most effectively at 450–550 K (corresponding to a DC voltage variation of only ∼7 V) and completely shields terahertz radiation above 550 K in a frequency range of 0.1–2.5 THz. Both intrinsic and doped silicon wafers were tested and demonstrated to work well as a continuously tunable attenuator. All behaviors can be understood quantitatively via the free-carrier Drude model taking into account thermally activated intrinsic carriers.

  19. Electrically tunable hot-silicon terahertz attenuator

    International Nuclear Information System (INIS)

    We have developed a continuously tunable, broadband terahertz attenuator with a transmission tuning range greater than 103. Attenuation tuning is achieved electrically, by simply changing the DC voltage applied to a heating wire attached to a bulk silicon wafer, which controls its temperature between room temperature and ∼550 K, with the corresponding free-carrier density adjusted between ∼1011 cm−3 and ∼1017 cm−3. This “hot-silicon”-based terahertz attenuator works most effectively at 450–550 K (corresponding to a DC voltage variation of only ∼7 V) and completely shields terahertz radiation above 550 K in a frequency range of 0.1–2.5 THz. Both intrinsic and doped silicon wafers were tested and demonstrated to work well as a continuously tunable attenuator. All behaviors can be understood quantitatively via the free-carrier Drude model taking into account thermally activated intrinsic carriers.

  20. 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.

  1. 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)

  2. Shock propagation and attenuation in Green River oil shale

    International Nuclear Information System (INIS)

    Shock waves produced by planar impact of thin plates onto samples of oil shale are monitored with time-resolved velocity interferometer diagnostics. Peak shock stresses are below the Hugoniot elastic limit. Stress wave measurements at successive sample thickness are analysed to determine the experimental shock energy attenuation with propagation distance. Shock attenuation is attributed to stress wave scattering at planes of oil shale kerogen within the shale matrix. Wave scattering from planar defects are evaluated from a shock physics perspective and a scattering model is constructed that sensibly reproduces the experimental observation of shock energy attenuation.

  3. 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

  4. 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.

  5. Comparison between Immunization Routes of Live Attenuated Salmonella Typhimurium Strains Expressing BCSP31, Omp3b, and SOD of Brucella abortus in Murine Model

    Science.gov (United States)

    Kim, Won K.; Moon, Ja Y.; Kim, Suk; Hur, Jin

    2016-01-01

    Live, attenuated Salmonella Typhimurium vaccine candidate expressing BCSP31, Omp3b, and SOD proteins of Brucella abortus was constructed. Thirty BALB/c mice were divided equally into three groups, Group A, were intraperitoneally (IP) inoculated with 100 μl of approximately 1.2 × 106 colony-forming units (CFUs)/ml of the Salmonella containing vector only in 100 μl as a control. And groups B and C mice were orally and IP immunized with approximately 1.2 × 109 CFU/ml of the mixture of three delivery strains in 10 μl and IP immunized with approximately 1.2 × 106 CFU/ml of the mixture in 100 μl, respectively. The serum IgG, TNF-α and IFN-γ concentrations in groups B (except Omp3b) and C were significantly higher than those in group A. Following challenge with B. abortus strain 544; challenge strain was detected <103 CFU from the spleen of all mice of group C. These results suggest that IP immunization with the mixture of the vaccine candidate can induce immune responses, and can effectively protect mice against brucellosis. PMID:27148232

  6. Murine immunization by cesium-137 irradiation attenuated Schistosoma mansoni cercariae

    International Nuclear Information System (INIS)

    Cesium-137, becoming a more readily available ionizing gamma radiation source for laboratory use, was shown to effectively attenuate Schistosoma mansoni cercariae for vaccine production. In parallel comparison studies with the murine model, cesium-137 attenuated cercariae consistently afforded better protection than did the cobalt-60 prepared vaccine. Dose-response data indicated that the optimal total irradiation with cesium-137 was between 45 and 50 Krad

  7. Murine immunization by cesium-137 irradiation attenuated Schistosoma mansoni cercariae

    Energy Technology Data Exchange (ETDEWEB)

    Stek, M. Jr.; Minard, P.; Cruess, D.F.

    1984-06-01

    Cesium-137, becoming a more readily available ionizing gamma radiation source for laboratory use, was shown to effectively attenuate Schistosoma mansoni cercariae for vaccine production. In parallel comparison studies with the murine model, cesium-137 attenuated cercariae consistently afforded better protection than did the cobalt-60 prepared vaccine. Dose-response data indicated that the optimal total irradiation with cesium-137 was between 45 and 50 Krad.

  8. Self-attenuation correction in the environmental sample gamma spectrometry

    International Nuclear Information System (INIS)

    Self-attenuation corrections were calculated for gamma ray spectrometry of environmental samples with densities from 0.42 g/ml up to 1.59 g/ml, measured in Marinelli beakers and polyethylene flasks. These corrections are to be used when the counting efficiency is calculated for water measured in the same geometry. The model of Debertin for Marinelli beaker, numerical integration and experimental linear attenuation coefficients were used. (author). 3 refs., 4 figs., 6 tabs

  9. Action-related auditory ERP attenuation: Paradigms and hypotheses.

    Science.gov (United States)

    Horváth, János

    2015-11-11

    A number studies have shown that the auditory N1 event-related potential (ERP) is attenuated when elicited by self-induced or self-generated sounds. Because N1 is a correlate of auditory feature- and event-detection, it was generally assumed that N1-attenuation reflected the cancellation of auditory re-afference, enabled by the internal forward modeling of the predictable sensory consequences of the given action. Focusing on paradigms utilizing non-speech actions, the present review summarizes recent progress on action-related auditory attenuation. Following a critical analysis of the most widely used, contingent paradigm, two further hypotheses on the possible causes of action-related auditory ERP attenuation are presented. The attention hypotheses suggest that auditory ERP attenuation is brought about by a temporary division of attention between the action and the auditory stimulation. The pre-activation hypothesis suggests that the attenuation is caused by the activation of a sensory template during the initiation of the action, which interferes with the incoming stimulation. Although each hypothesis can account for a number of findings, none of them can accommodate the whole spectrum of results. It is suggested that a better understanding of auditory ERP attenuation phenomena could be achieved by systematic investigations of the types of actions, the degree of action-effect contingency, and the temporal characteristics of action-effect contingency representation-buildup and -deactivation. This article is part of a Special Issue entitled SI: Prediction and Attention. PMID:25843932

  10. 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

  11. 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

  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

    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.

  13. 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

  14. 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.

  15. 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).

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. Ultrasound velocity and attenuation of liquid 4He in aerogel

    International Nuclear Information System (INIS)

    The ultrasound velocity and attenuation of liquid 4He in various porosity aerogels were measured for a frequency of 10 MHz. The superfluid transition temperature was suppressed by aerogel which was determined as a dip of sound velocity and a attenuation peak. Sound velocity in this composite system depended seriously on the aerogel porosity. An aerogel-4He composite model, in which normal fluid was clamped to aerogel strand gave almost satisfactory temperature and aerogel porosity dependence of the sound velocity. The sound attenuation in aerogel was considerably larger than that in bulk liquid. That in the normal phase had small porosity dependence. However, that in the superfluid phase decreased with decreasing temperature and became constant at low temperatures. The attenuation peak ascribed to roton-phonon interaction was not observed in aerogel-4He system

  2. 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.

  3. 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

  4. 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.

  5. Impact of MR based attenuation correction on neurological PET studies

    Science.gov (United States)

    Su, Yi; Rubin, Brian B.; McConathy, Jonathan; Laforest, Richard; Qi, Jing; Sharma, Akash; Priatna, Agus; Benzinger, Tammie L.S.

    2016-01-01

    Hybrid positron emission tomography (PET) and magnetic resonance (MR) scanners have become a reality in recent years with the benefits of reduced radiation exposure, reduction of imaging time, and potential advantages in quantification. Appropriate attenuation correction remains a challenge. Biases in PET activity measurements were demonstrated using the current MR based attenuation correction technique. We aim to investigate the impact of using standard MRAC technique on the clinical and research utility of PET/MR hybrid scanner for amyloid imaging. Methods Florbetapir scans were obtained on 40 participants on a Biograph mMR hybrid scanner with simultaneous MR acquisition. PET images were reconstructed using both MR and CT derived attenuation map. Quantitative analysis was performed for both datasets to assess the impact of MR based attenuation correction to absolute PET activity measurements as well as target to reference ratio (SUVR). Clinical assessment was also performed by a nuclear medicine physician to determine amyloid status based on the criteria in the FDA prescribing information for florbetapir. Results MR based attenuation correction led to underestimation of PET activity for most part of the brain with a small overestimation for deep brain regions. There is also an overestimation of SUVR values with cerebellar reference. SUVR measurements obtained from the two attenuation correction methods were strongly correlated. Clinical assessment of amyloid status resulted in identical classification as positive or negative regardless of the attenuation correction methods. Conclusions MR based attenuation correction cause biases in quantitative measurements. The biases may be accounted for by a linear model, although the spatial variation cannot be easily modelled. The quantitative differences however did not affect clinical assessment as positive or negative. PMID:26823562

  6. 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.

  7. 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...

  8. An empirical model that uses light attenuation and plant nitrogen status to predict within-canopy nitrogen distribution and upscale photosynthesis from leaf to whole canopy

    OpenAIRE

    Louarn, Gaëtan; Frak, Elzbieta; Zaka, Serge; Prieto, Jorge; Lebon, Eric

    2015-01-01

    Modelling the spatial and temporal distribution of leaf nitrogen is central to specify photosynthetic parameters and simulate canopy photosynthesis. Leaf photosynthetic parameters depend both on local light availability and whole plant N status. The interaction between these two levels of integration has generally been modelled by assuming an optimal canopy functioning, which is not supported by experiments. During this study we examined how a set of empirical relationships with measurable pa...

  9. 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-...

  10. 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.)

  11. 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.)

  12. Coriolis attenuation in the rare earth region

    International Nuclear Information System (INIS)

    It is shown that the observed rotational band structure in a number of odd-proton and odd-neutron nuclei situated in the rare earth region, can be reproduced in the particle-rotor model without any ad hoc reduction of the Coriolis matrix elements if a value of the pairing gap parameter, which is about 30-40% of that deduced from the corresponding odd-even mass difference, is used. The importance of the proper choice of the pairing gap parameter in the study of the Coriolis attenuation problem is emphasised. (orig.)

  13. Lateral Variations Of Macroseismic Intensity Attenuation In Italy

    Science.gov (United States)

    Carletti, F.; Gasperini, P.

    Using the Italian unified intensity database, a tomographic type study of the attenua- tion of macroseismic intensity on the Italian territory has been carried out on the basis of a bilinear model recently proposed by Gasperini (2001). The spatial variations of the attenuation coefficients on meshes with sides of 50 and 25 km have been computed. By checkerboard and restore tests, with a realistic standard error of one intensity de- gree, we verified that our dataset of about 20000 paths is able to well reproduce the imposed patterns. The comparison of inversion results with crustal and upper mantle seismic wave tomography of the Italian area show a fairly good agreement between high attenuation and low velocity areas (Northern and central Apennines) and between low attenuation and high velocity ones (Po valley and Adriatic coast). The resulting attenuation pattern also agrees with a set of Nonparametric Attenuation Functions (NAF) describing the attenuation of crustal phases in different regions of Italy and shows a rather strong correspondence with heat-flow data. This study also furnished a compilation of average local residuals that have been correlated with the geological, geotechnical and morphological characteristics of sites.

  14. 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…

  15. 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...

  16. 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...

  17. Attenuation of Vrancea events revisited

    International Nuclear Information System (INIS)

    New aspects of the frequency-dependent attenuation of the seismic waves traveling from Vrancea subcrustal sources toward NW (Transylvanian Basin) and SE (Romanian Plain) are evidenced by the recent experimental data made available by the CALIXTO'99 tomography experiment. The observations validate the previous theoretical computations performed for the assessment, by means of a deterministic approach, of the seismic hazard in Romania. They reveal an essential aspect of the seismic ground motion attenuation, that has important implications on the probabilistic assessment of seismic hazard from Vrancea intermediate-depth earthquakes. The attenuation toward NW is shown to be a much stronger frequency-dependent effect than the attenuation toward SE and the seismic hazard computed by the deterministic approach fits satisfactorily well the observed ground motion distribution in the low-frequency band (< 1 Hz). The apparent contradiction with the historically-based intensity maps arises mainly from a systematic difference in the vulnerability (buildings eigenperiod) of the buildings in the intra- and extra-Carpathians regions. (author)

  18. 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.

  19. 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...

  20. 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...

  1. Oral Administration of Gintonin Attenuates Cholinergic Impairments by Scopolamine, Amyloid-β Protein, and Mouse Model of Alzheimer’s Disease

    OpenAIRE

    Kim, Hyeon-Joong; Shin, Eun-Joo; Lee, Byung-Hwan; Choi, Sun-Hye; Jung, Seok-Won; Cho, Ik-Hyun; Hwang, Sung-Hee; Kim, Joon Yong; Han, Jung-Soo; Chung, ChiHye; Jang, Choon-Gon; Rhim, Hyewon; Kim, Hyoung-Chun; Nah, Seung-Yeol

    2015-01-01

    Gintonin is a novel ginseng-derived lysophosphatidic acid (LPA) receptor ligand. Oral administration of gintonin ameliorates learning and memory dysfunctions in Alzheimer’s disease (AD) animal models. The brain cholinergic system plays a key role in cognitive functions. The brains of AD patients show a reduction in acetylcholine concentration caused by cholinergic system impairments. However, little is known about the role of LPA in the cholinergic system. In this study, we used gintonin to i...

  2. Calculation and validation of the use of effective attenuation coefficient for attenuation correction in In-111 SPECT

    International Nuclear Information System (INIS)

    Nuclear medicine tracers using 111In as a radiolabel are increasing in their use, especially in the domain of oncologic imaging. In these applications, it often is critical to have the capability of quantifying radionuclide uptake and being able to relate it to the biological properties of the tumor. However, images from single photon emission computed tomography (SPECT) can be degraded by photon attenuation, photon scattering, and collimator blurring; without compensation for these effects, image quality can be degraded, and accurate and precise quantification is impossible. Although attenuation correction for SPECT is becoming more common, most implementations can only model single energy radionuclides such as 99mTc and 123I. Thus, attenuation correction for 111In is challenging because it emits two photons (171 and 245 keV) at nearly equal rates (90.2% and 94% emission probabilities). In this paper, we present a method of calculating a single 'effective' attenuation coefficient for the dual-energy emissions of 111In, and that can be used to correct for photon attenuation in radionuclide images acquired with this radionuclide. Using this methodology, we can derive an effective linear attenuation coefficient μeff and an effective photon energy Eeff based on the emission probabilities and linear attenuation coefficients of the 111In photons. This approach allows us to treat the emissions from 111In as a single photon with an effective energy of 210 keV. We obtained emission projection data from a tank filled with a uniform solution of 111In. The projection data were reconstructed using an iterative maximum-likelihood algorithm with no attenuation correction, and with attenuation correction assuming photon energies of 171, 245, and 210 keV (the derived Eeff). The reconstructed tomographic images demonstrate that the use of no attenuation correction, or correction assuming photon energies of 171 or 245 keV introduces inaccuracies into the reconstructed radioactivity

  3. 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)

  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. Ferrite attenuator modulation improves antenna performance

    Science.gov (United States)

    Hooks, J. C.; Larson, S. G.; Shorkley, F. H.; Williams, B. T.

    1970-01-01

    Ferrite attenuator inserted into appropriate waveguide reduces the gain of the antenna element which is causing interference. Modulating the ferrite attenuator to change the antenna gain at the receive frequency permits ground tracking until the antenna is no longer needed.

  7. Tat-ATOX1 inhibits streptozotocin-induced cell death in pancreatic RINm5F cells and attenuates diabetes in a mouse model.

    Science.gov (United States)

    Ahn, Eun Hee; Kim, Dae Won; Shin, Min Jea; Ryu, Eun Ji; Yong, Ji In; Chung, Seok Young; Cha, Hyun Ju; Kim, Sang Jin; Choi, Yeon Joo; Kim, Duk-Soo; Cho, Sung-Woo; Lee, Keunwook; Cho, Yoon Shin; Kwon, Hyeok Yil; Park, Jinseu; Eum, Won Sik; Choi, Soo Young

    2016-07-01

    Antioxidant 1 (ATOX1) functions as an antioxidant against hydrogen peroxide and superoxide, and therefore may play a significant role in many human diseases, including diabetes mellitus (DM). In the present study, we examined the protective effects of Tat-ATOX1 protein on streptozotocin (STZ)-exposed pancreatic insulinoma cells (RINm5F) and in a mouse model of STZ-induced diabetes using western blot analysis, immunofluorescence staining and MTT assay, as well as histological and biochemical analysis. Purified Tat-ATOX1 protein was efficiently transduced into RINm5F cells in a dose- and time-dependent manner. Additionally, Tat-ATOX1 protein markedly inhibited reactive oxygen species (ROS) production, DNA damage and the activation of Akt and mitogen activated protein kinases (MAPKs) in STZ-exposed RINm5F cells. In addition, Tat-ATOX1 protein transduced into mice pancreatic tissues and significantly decreased blood glucose and hemoglobin A1c (HbA1c) levels as well as the body weight changes in a model of STZ-induced diabetes. These results indicate that transduced Tat-ATOX1 protein protects pancreatic β-cells by inhibiting STZ-induced cellular toxicity in vitro and in vivo. Based on these findings, we suggest that Tat-ATOX1 protein has potential applications as a therapeutic agent for oxidative stress-induced diseases including DM. PMID:27222268

  8. 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.

  9. 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).

  10. 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

  11. 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

  12. 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.

  13. 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

  14. Polymerized nano-curcumin attenuates neurological symptoms in EAE model of multiple sclerosis through down regulation of inflammatory and oxidative processes and enhancing neuroprotection and myelin repair.

    Science.gov (United States)

    Mohajeri, Maryam; Sadeghizadeh, Majid; Najafi, Farhood; Javan, Mohammad

    2015-12-01

    Multiple Sclerosis (MS) is an inflammatory demyelinating disorder of central nervous system (CNS). Polyphenol curcumin has been used in traditional medicine as an effective drug for a variety of diseases. Different formulations of curcumin are introduced to increase its stability and effectiveness. Here we have examined the effect of polymerized form of nano-curcumin (PNC) on experimental autoimmune encephalomyelitis (EAE) as an animal model of MS. EAE was induced in female Lewis rats and PNC or curcumin was daily administrated intraperitonealy from day 12-29 post immunization. When the prophylactic effect of PNC was under investigation, rats received PNC from the first day of immunization. Treatment with PNC resulted in decreased scores of disease in therapeutic and prophylactic administration when compared with control group. Staining by luxol fast blue and H&E and immuno-staining of lumbar spinal cord cross sections, confirmed a significant decrease in the amounts of demyelination, inflammation and BBB breaking down. Gene expression studies in lumbar spinal cord showed a corrected balance of pro-inflammatory and anti-inflammatory genes expression, decreased oxidative stress, improved remyelination and increased progenitor cell markers after treatment with PNC. Our results demonstrated an efficient therapeutic effect of PNC as an anti-inflammatory and anti-oxidative stress agent, with significant effects on the EAE scores and myelin repair mechanisms. PMID:26211978

  15. 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.

  16. The effect of sulindac, a non-steroidal anti-inflammatory drug, attenuates inflammation and fibrosis in a mouse model of chronic pancreatitis

    Directory of Open Access Journals (Sweden)

    Bai Han

    2012-08-01

    Full Text Available Abstract Background Chronic pancreatitis is characterized by progressive fibrosis, pain and loss of exocrine and endocrine functions. The long-standing chronic pancreatitis and its associated pancreatic fibrosis are the most common pathogenic events involved in human pancreatic carcinogenesis, but the therapeutic strategies to chronic pancreatitis and the chemoprevention of pancreatic carcinogenesis are very limited. Methods We investigated the effect of sulindac, a non-steroidal anti-inflammatory drug (NSAID, on inhibition of chronic pancreatitis in a caerulein induced chronic pancreatitis mouse model. Results Sulindac significantly reduced the severity of chronic pancreatitis including the extent of acini loss, inflammatory cell infiltration and stromal fibrosis. The protein expression of phosphorylation of MEK/ERK was inhibited in the chronic pancreatic tissues by sulindac treatment as measured by Western blot assay. The levels of inflammatory cytokines including TNF-α and MCP-1 were also significantly decreased with sulindac treatment, as well as the expression of TGF-β, PDGF-β, SHH and Gli in the chronic pancreatic tissue detected by qPCR assay and confirmed by western blot assay. The activation of pancreatic satellet cells was also inhibited by sulindac as measured by the activity of α-smooth muscle actin (α-SMA in the pancreatic tissue of chronic pancreatitis. Conclusions Sulindac is a promising reagent for the treatment of chronic pancreatitis via inhibition of inflammatory cell infiltration and stromal fibrosis, the inhibitory effect of sulindac on chronic pancreatitis may through targeting the activation ERK/MAPK signaling pathway.

  17. Possible solution of the Coriolis attenuation problem

    International Nuclear Information System (INIS)

    The most consistently useful simple model for the study of odd deformed nuclei, the particle-rotor model (strong-coupling limit of the core-particle coupling model) has nevertheless been beset by a long-standing problem: It is necessary in many cases to introduce an ad hoc parameter that reduces the size of the Coriolis interaction coupling the collective and single-particle motions. Of the numerous suggestions put forward for the origin of this supplementary interaction, none of those actually tested by calculations has been accepted as the solution of the problem. In this paper we seek a solution for the difficulty within the framework of a general formalism that starts from the spherical shell model and is capable of treating an arbitrary linear combination of multipole and pairing forces. With the restriction of the interaction to the familiar sum of a quadrupole multipole force and a monopole pairing force, we have previously studied a semimicroscopic version of the formalism whose framework is nevertheless more comprehensive than any previously applied to the problem. We obtained solutions for low-lying bands of several strongly deformed odd rare-earth nuclei and found good agreement with experiment, except for an exaggerated staggering of levels for K=(1)/(2) bands, which can be understood as a manifestation of the Coriolis attenuation problem. We argue that within the formalism utilized, the only way to improve the physics is to add interactions to the model Hamiltonian. We verify that by adding a magnetic dipole interaction of essentially fixed strength, we can fit the K=(1)/(2) bands without destroying the agreement with other bands. In addition we show that our solution also fits 163Er, a classic test case of Coriolis attenuation that we had not previously studied. copyright 1997 The American Physical Society

  18. Cobalt Protoporphyrin Improves Heart Function by Attenuating Cardiac Beta-oxidation and Restoring Redox Balance in an Animal Model of Experimental Diabetes

    Directory of Open Access Journals (Sweden)

    NaderG.Abraham

    2012-06-01

    Full Text Available Myocardial dysfunction and coronary macro/microvascular alterations are the hallmarks of diabetic cardiomyopathy and are ascribed to increased oxidative stress and altered nitric oxide synthase (NOS activity. We hypothesize that pretreatment by cobalt-protoporphyrin IX (CoPP ameliorates both myocardial function and coronary circulation in streptozotocin(STZ-induced diabetic rats. Isolated hearts from diabetic rats in Langendorff configuration displayed lower left ventricular (LV function and higher coronary resistance (CR compared to hearts from control animals. CoPP treatment of diabetic animals (0.3mg/100g body weight i.p., once a week for three weeks significantly increased all the contractile/relaxation indexes (p<0.01, while decreasing CR (p<0.01. CoPP enhanced HO-1 protein levels and reduced oxidative/nitrosative stress in diabetic animals, as indicated by the significant (p<0.05 decrease in heart GSSG/GSHtotal, O2-, malondialdehyde (MDA, and 3-nitrotyrosine levels. CoPP increased adiponectin levels and phosphorylation of AKT and AMPK and reversed the eNOS/iNOS expression imbalance observed in the untreated diabetic heart. Furthermore, after CoPP treatment, a rise in malonylCoA as well as a decrease in acetylCoA was observed in diabetic hearts. In this experimental model of diabetic cardiomyopathy, CoPP treatment improved both cardiac function and coronary flow by blunting oxidative/nitrosative stress, restoring eNOS/ iNOS expression balance and increasing HO-1 levels, thereby favoring improvement in both endothelial function and insulin sensitivity.

  19. 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

  20. Low-dose benznidazole treatment results in parasite clearance and attenuates heart inflammatory reaction in an experimental model of infection with a highly virulent Trypanosoma cruzi strain.

    Science.gov (United States)

    Cevey, Ágata Carolina; Mirkin, Gerardo Ariel; Penas, Federico Nicolás; Goren, Nora Beatriz

    2016-04-01

    Chagas disease, caused by Trypanosoma cruzi, is the main cause of dilated cardiomyopathy in the Americas. Antiparasitic treatment mostly relies on benznidazole (Bzl) due to Nifurtimox shortage or unavailability. Both induce adverse drug effects (ADE) of varied severity in many patients, leading to treatment discontinuation or abandonment. Since dosage may influence ADE, we aimed to assess Bzl efficacy in terms of parasiticidal and anti-inflammatory activity, using doses lower than those previously reported. BALB/c mice infected with the T. cruzi RA strain were treated with different doses of Bzl. Parasitaemia, mortality and weight change were assessed. Parasite load, tissue infiltrates and inflammatory mediators were studied in the heart. Serum creatine kinase (CK) activity was determined as a marker of heart damage. The infection-independent anti-inflammatory properties of Bzl were studied in an in vitro model of LPS-treated cardiomyocyte culture. Treatment with 25 mg/kg/day Bzl turned negative the parasitological parameters, induced a significant decrease in IL-1β, IL-6 and NOS2 in the heart and CK activity in serum, to normal levels. No mortality was observed in infected treated mice. Primary cultured cardiomyocytes treated with Bzl showed that inflammatory mediators were reduced via inhibition of the NF-κB pathway. A Bzl dose lower than that previously reported for treatment of experimental Chagas disease exerts adequate antiparasitic and anti-inflammatory effects leading to parasite clearance and tissue healing. This may be relevant to reassess the dose currently used for the treatment of human Chagas disease, aiming to minimize ADE. PMID:26862474

  1. 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.

  2. 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.

  3. 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.

  4. Antagonism of the adenosine A2A receptor attenuates akathisia-like behavior induced with MP-10 or aripiprazole in a novel non-human primate model.

    Science.gov (United States)

    Bleickardt, Carina J; Kazdoba, Tatiana M; Jones, Nicholas T; Hunter, John C; Hodgson, Robert A

    2014-03-01

    Akathisia is a subset of the larger antipsychotic side effect profile known as extrapyramidal syndrome (EPS). It is associated with antipsychotic treatment and is characterized as a feeling of inner restlessness that results in a compulsion to move. There are currently no primate models available to assess drug-induced akathisia; the present research was designed to address this shortcoming. We developed a novel rating scale based on both the Barnes Akathisia Rating Scale (BARS) and the Hillside Akathisia Scale (HAS) to measure the objective, observable incidence of antipsychotic-induced akathisia-like behavior in Cebus apella non-human primates (NHPs). To induce akathisia, we administered the atypical antipsychotic aripiprazole (1 mg/kg) or the selective phosphodiesterase 10A (PDE10A) inhibitor MP-10 (1-3 mg/kg). Treatment with both compounds produced significantly greater akathisia scores on the rating scale than vehicle treatment. Characteristic behaviors observed included vocalizations, stereotypies, teeth grinding, restless limb movements, and hyperlocomotion. Adenosine A2A receptor antagonists have previously been shown to be effective in blocking antipsychotic-induced EPS in primates. The selective A2A receptor antagonist, SCH 412348 (10-30 mg/kg), effectively reduced or reversed akathisia-like behavior induced by both aripiprazole and MP-10. This work represents the first NHP measurement scale of akathisia and demonstrates that NHPs are responsive to akathisia-inducing agents. As such, it provides a useful tool for the preclinical assessment of putative antipsychotics. In addition, these results provide further evidence of the utility of A2A receptor antagonists for the treatment of antipsychotic-induced movement disorders. PMID:24211858

  5. 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.

  6. 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. Context discovery using attenuated Bloom filters in ad-hoc networks

    OpenAIRE

    Liu, Fei; Heijenk, Geert; Braun, Torsten; Carle, Georg; Fahmy, Sonia; Koucheryavy, Yevgeni

    2006-01-01

    A novel approach to performing context discovery in ad-hoc networks based on the use of attenuated Bloom filters is proposed in this paper. In order to investigate the performance of this approach, a model has been developed. This document describes the model and its validation. The model has been implemented in Matlab, and some results are also shown in this document. Attenuated Bloom filters appear to be a very promising approach for context discovery in ad hoc networks.

  2. 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.

  3. Antiallodynic effects of alpha lipoic acid in an optimized RR-EAE mouse model of MS-neuropathic pain are accompanied by attenuation of upregulated BDNF-TrkB-ERK signaling in the dorsal horn of the spinal cord.

    Science.gov (United States)

    Khan, Nemat; Gordon, Richard; Woodruff, Trent M; Smith, Maree T

    2015-06-01

    Neuropathic pain may affect patients with multiple sclerosis (MS) even in early disease. In an experimental autoimmune encephalomyelitis (EAE)-mouse model of MS, chronic alpha lipoic acid (ALA) treatment reduced clinical disease severity, but MS-neuropathic pain was not assessed. Hence, we investigated the pain-relieving efficacy and mode of action of ALA using our optimized relapsing-remitting (RR)-EAE mouse model of MS-associated neuropathic pain. C57BL/6 mice were immunized with MOG35-55 and adjuvants (Quil A and pertussis toxin) to induce RR-EAE; sham-mice received adjuvants only. RR-EAE mice received subcutaneous ALA (3 or 10 mg kg(-1) day(-1)) or vehicle for 21 days (15-35 d.p.i.; [days postimmunization]); sham-mice received vehicle. Hindpaw hypersensitivity was assessed blinded using von Frey filaments. Following euthanasia (day 35 d.p.i.), lumbar spinal cords were removed for immunohistochemical and molecular biological assessments. Fully developed mechanical allodynia in the bilateral hindpaws of vehicle-treated RR-EAE mice was accompanied by marked CD3(+) T-cell infiltration, microglia activation, and increased brain-derived neurotrophic factor (BDNF)-tyrosine kinase B (TrkB) signaling in the dorsal horn of the lumbar spinal cord. Consequently, phospho-ERK, a marker of central sensitization in neuropathic pain, was upregulated in the spinal dorsal horn. Importantly, hindpaw hypersensitivity was completely attenuated in RR-EAE mice administered ALA at 10 mg kg(-1) day(-1) but not 3 mg kg(-1) day(-1). The antiallodynic effect of ALA (10 mg kg(-1) day(-1)) was associated with a marked reduction in the aforementioned spinal dorsal horn markers to match their respective levels in the vehicle-treated sham-mice. Our findings suggest that ALA at 10 mg kg(-1) day(-1) produced its antiallodynic effects in RR-EAE mice by reducing augmented CD3(+) T-cell infiltration and BDNF-TrkB-ERK signaling in the spinal dorsal horn. PMID:26171221

  4. Differential dust attenuation in CALIFA galaxies

    Science.gov (United States)

    Vale Asari, N.; Cid Fernandes, R.; Amorim, A. L.; Lacerda, E. A. D.; Schlickmann, M.; Wild, V.; Kennicutt, R. C.

    2016-06-01

    Dust attenuation has long been treated as a simple parameter in SED fitting. Real galaxies are, however, much more complicated: The measured dust attenuation is not a simple function of the dust optical depth, but depends strongly on galaxy inclination and the relative distribution of stars and dust. We study the nebular and stellar dust attenuation in CALIFA galaxies, and propose some empirical recipes to make the dust treatment more realistic in spectral synthesis codes. By adding optical recombination emission lines, we find better constraints for differential attenuation. Those recipes can be applied to unresolved galaxy spectra, and lead to better recovered star formation rates.

  5. Prediction of spectral acceleration response ordinates based on PGA attenuation

    Science.gov (United States)

    Graizer, V.; Kalkan, E.

    2009-01-01

    Developed herein is a new peak ground acceleration (PGA)-based predictive model for 5% damped pseudospectral acceleration (SA) ordinates of free-field horizontal component of ground motion from shallow-crustal earthquakes. The predictive model of ground motion spectral shape (i.e., normalized spectrum) is generated as a continuous function of few parameters. The proposed model eliminates the classical exhausted matrix of estimator coefficients, and provides significant ease in its implementation. It is structured on the Next Generation Attenuation (NGA) database with a number of additions from recent Californian events including 2003 San Simeon and 2004 Parkfield earthquakes. A unique feature of the model is its new functional form explicitly integrating PGA as a scaling factor. The spectral shape model is parameterized within an approximation function using moment magnitude, closest distance to the fault (fault distance) and VS30 (average shear-wave velocity in the upper 30 m) as independent variables. Mean values of its estimator coefficients were computed by fitting an approximation function to spectral shape of each record using robust nonlinear optimization. Proposed spectral shape model is independent of the PGA attenuation, allowing utilization of various PGA attenuation relations to estimate the response spectrum of earthquake recordings.

  6. 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 $\\sqrt{H}$.

  7. 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)

  8. Mathematical approach to determine the linear attenuation coefficient without collimator in gamma-ray spectrometry

    International Nuclear Information System (INIS)

    The linear attenuation coefficient is an important factor in the correction of self-attenuation. In this study, a cone beam from a source of ∼1 μCi was utilised, not equipped with the collimator, and a complete geometric configuration was mathematically modelled. Samples of NaCl, Na2CO3 and (NH4)2SO4 were used to verify the mathematical model. The linear attenuation coefficient can be calculated within ∼4 % of difference in the cylindrical sample at energies of 59.5, 121.8, 244.7, 344.2 and 444.0 keV. (authors)

  9. Mathematical approach to determine the linear attenuation coefficient without collimator in gamma-ray spectrometry.

    Science.gov (United States)

    Kim, Chang-Jong; Cho, Yoon-Hae; Byun, Jong-In; Yun, Ju-Yong

    2013-07-01

    The linear attenuation coefficient is an important factor in the correction of self-attenuation. In this study, a cone beam from a source of ∼1 μCi was utilised, not equipped with the collimator, and a complete geometric configuration was mathematically modelled. Samples of NaCl, Na2CO3 and (NH4)2SO4 were used to verify the mathematical model. The linear attenuation coefficient can be calculated within ∼4 % of difference in the cylindrical sample at energies of 59.5, 121.8, 244.7, 344.2 and 444.0 keV. PMID:23230217

  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. Coriolis attenuation effect on the band crossing frequency of 164Er96

    International Nuclear Information System (INIS)

    The accurate solutions to the low-lying eigenstates of the cranked shell model Hamiltonian are obtained by the particle number-conserving treatment, in which Coriolis attenuation is considered. Compared with experiments, the results are much better than before

  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. Docking-mechanism attenuator with electromechanical damper

    Science.gov (United States)

    Syromyatnikov, V. S.

    1971-01-01

    Theoretical and practical problems involved in the application of electromechanical damping for spacecraft docking-mechanism attenuation are discussed. Some drawbacks of hydraulic dampers used for the purpose are pointed out. The basic scheme of the attenuator with the electromechanical damper is given.

  14. Theory of standing spin-wave attenuation

    International Nuclear Information System (INIS)

    Exchange attenuation of standing spin waves is calculated for an ultrathin magnetic of the order of exchange length thick. Because of the boundary conditions the wave vectors of spin waves in such films high values that are proportional to the inverse film thickness. The exchange attenuation at such wave vectors becomes dominant and can result in smearing of the standing spin wave spectrum

  15. Mantle-Lid P Wave Attenuation in the Korean Peninsula

    Science.gov (United States)

    Lee, K.; Hong, T.

    2012-12-01

    The mantle-lid P wave, Pn, is the first arrival phase in regional distances. The Pn waves are widely analyzed for estimation of event sizes. Also, it is known that analysis of Pn waves is effective for discrimination of nuclear explosions from natural earthquakes. The attenuation of Pn waves provides us information on medium properties in mantle lid. It is crucial to understand the nature of Pn attenuation for correct estimation of event sizes from Pn amplitudes. We investigate the lateral variation of Pn attenuation in the mantle lid of the Korean Peninsula from vertical regional seismograms for events around the Korean Peninsula and Japanese islands. The number of events is 149, and the focal depths are less than 50 km. The seismic records with signal-to-noise ratios greater than 1.5 are analyzed. The number of stations is 121. The Pn quality factors are calculated using a two-station method in which ratios of Pn displacement spectra of stations on the same azimuths are used. The power-law frequency dependence term is estimated using a least-squares fitting for quality factors at frequencies from 0.37 Hz to 25 Hz. The number of station pairs is 3317. The average quality factor at 1 Hz is determined to be about 67, which is consistent with previous studies. We present the resultant Pn attenuation model, and discuss the correlations with geological and geophysical properties in the medium.

  16. Context discovery using attenuated Bloom filters in ad-hoc networks

    OpenAIRE

    Liu, Fei; Heijenk, Geert

    2007-01-01

    A novel approach to performing context discovery in ad-hoc networks based on the use of attenuated Bloom filters is proposed in this paper. A Bloom filter is an efficient spacesaving data structure to represent context information. Attenuated Bloom filters are used to advertise the availability of context information multiple hops away, and to guide queries to discover it. In order to investigate the performance of this approach, a model has been developed. This paper describes the model and ...

  17. World-wide link availability for geostationary and critically inclined orbits including rain attenuation effects

    Science.gov (United States)

    Schwab, L. M.

    1981-01-01

    Link availability for constellations of satellites in geostationary and critically inclined orbits is computed using a predictor model based on the Crane 8 region worldwide rain attenuation model. The results are contrasted to percent Earth visibility computations which do not include rain attenuation. For geostationary satellite constellations, the quantitative relationship for Earth coverage vs link margin vs availability vs number of satellites is described by a set of parametric curves.

  18. 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.

  19. 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...

  20. 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.

  1. 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.

  2. 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...

  3. 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...

  4. Plasmodium falciparum: attenuation by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Waki, S.; Yonome, I.; Suzuki, M.

    1983-12-01

    The effect of irradiation on the in vitro growth of Plasmodium falciparum was investigated. The cultured malarial parasites at selected stages of development were exposed to gamma rays and the sensitivity of each stage was determined. The stages most sensitive to irradiation were the ring forms and the early trophozoites; late trophozoites were relatively insensitive. The greatest resistance was shown when parasites were irradiated at a time of transition from the late trophozoite and schizont stages to young ring forms. The characteristics of radiosensitive variation in the parasite cycle resembled that of mammalian cells. Growth curves of parasites exposed to doses of irradiation upto 150 gray had the same slope as nonirradiated controls but parasites which were exposed to 200 gray exhibited a growth curve which was less steep than that for parasites in other groups. Less than 10 organisms survived from the 10(6) parasites exposed to this high dose of irradiation; the possibility exists of obtaining radiation-attenuated P. falciparum.

  5. Beta attenuation transmission system (BATS)

    International Nuclear Information System (INIS)

    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/cm2, of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A 90Sr 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 (μP) 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

  6. 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.

  7. 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.

  8. Attenuation of thermal radiative heat fluxes by water curtain

    International Nuclear Information System (INIS)

    On offshore oil and gas platforms, thermal or infra-red radiation emitted from hydrocarbon flares can have serious consequences on the safety and integrity of both personnel and equipment. At the temperatures of emission (∼ 1600 K), water is an excellent absorber of infra-red radiation, and this study investigates the potential for using a 'curtain' formed from a water spray to attenuate incident thermal radiation. A relatively simple model is devised to estimate the attenuation characteristics of a continuous layer of water, with further modification for the case of a spray It is found that a 120 deg. fog nozzle with an exit radius of r0 = 10 mm, supplied with 600 litres/minute of water at 3.5 bar, will provide adequate (down to a level of 1.9 kW/m2) attenuation for flame temperatures up to 2400 K. The dynamics of sprays are extremely complex and the current model does not consider interactions between aerodynamic drag, heat transfer, shape, size and distribution of droplets or surface tension effects. There appears to be potential for further refinement of the model, but this requires in-situ measurements. (author)

  9. 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

  10. Passive Underwater Noise Attenuation Using Large Encapsulated Air Bubbles.

    Science.gov (United States)

    Lee, Kevin M; Wochner, Mark S; Wilson, Preston S

    2016-01-01

    Measurements demonstrating low-frequency underwater sound attenuation using arrays of large, tethered, stationary encapsulated bubbles to surround a sound source were compared with various effective medium models for the acoustic dispersion relationship in bubbly liquids. Good agreement was observed between measurements for the large bubbles (on the order of 10 cm) at frequencies below 1 kHz and a model originally intended to describe the acoustic behavior of ultrasound contrast agents. The primary goal is to use the model for designing encapsulated-bubble-based underwater noise abatement systems and to reduce uncertainty in system performance. PMID:26611010

  11. Crustal attenuation characteristics in northwestern Turkey in the range from 1 to 10 Hz

    OpenAIRE

    Bindi, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Milano-Pavia, Milano, Italia; Parolai, S.; GeoForschungsZentrum Potsdam Telegrafenberg; Grosser, H.; GeoForschungsZentrum Potsdam Telegrafenberg; Milkereit, C.; GeoForschungsZentrum Potsdam Telegrafenberg; Karakisa, S.; Ministry of Public Works and Settlement General Directorate of Disaster Affairs Earthquake Research Department

    2006-01-01

    We have analyzed the aftershocks (ML 4.5) following the 1999 Izmit earthquake (Mw 7.4) to infer the frequency-dependent attenuation characteristics of both P and S waves, in the frequency range from 1 to 10 Hz and in the distance range from 10 to 140 km. A linear-predictive model is assumed to describe the spectral amplitudes in terms of attenuation and source contributions. The results show that both P and S waves undergo a strong attenuation along ray paths shorter than 40 k...

  12. Primary attenuation coefficient of a p(66)/Be(40) neutron therapy beam

    International Nuclear Information System (INIS)

    The concept of primary and scattered dose components of a radiotherapy beam is commonly used in radiotherapy planning. Four different methods which have been used for photon beams, were applied to determine the primary dose linear attenuation coefficient in water in a p(66)/Be(40) neutron beam. They were: the extrapolation of measured tissue-maximum ratios to zero field size; linear attenuation measurements; dose measurements in phantom with and without a central axis attenuator; and fitting a central axis kerma model, based on convolution techniques, to measured percentage depth dose data. 15 refs., 3 figs., 1 tab

  13. 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.

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.)

  19. 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.

  20. 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...

  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. Transient hepatic attenuation differences in neonates

    International Nuclear Information System (INIS)

    A transient hepatic attenuation difference (THAD) is a hepatic perfusion anomaly seen on contrast-enhanced CT scans caused by an alteration in the dual blood supply of the liver. Although THADs have been described in adolescents and adults, they have not previously been described in neonates. We describe the appearance and evaluate the frequency of THADs in neonates ≤1 month of age compared to other infants younger than 2 years. A retrospective study was performed looking at all CT angiograms from 2000 to 2007 in infants <2 years of age. The incidence of THADs was compared among four age groups. Significance was determined using a logistic regression model. The study included 128 CT angiograms. A THAD was seen in 9/26 infants <1 month of age, in 3/50 infants 1 to 6 months of age, in 1/23 infants 6 months to 1 year of age, and in 1/29 infants 1 to 2 years of age. A THAD was found significantly more frequently in infants <1 month of age than in the older age groups (P<0.05). THADs are benign entities that can be seen normally in the neonatal age group. When the characteristic appearance is seen on CT, no further imaging is needed. (orig.)

  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. Sildenafil attenuates placental ischemia-induced hypertension.

    Science.gov (United States)

    George, Eric M; Palei, Ana C; Dent, Edward A; Granger, Joey P

    2013-08-15

    Preeclampsia is a complication of pregnancy that is marked by hypertension, proteinuria, and maternal endothelial dysfunction. A central factor in the etiology of the disease is the development of placental hypoxia/ischemia, which releases pathogenic soluble factors. There is currently no effective treatment for preeclampsia, but the phosphodiesterase-5 (PDE-5) inhibitor sildenafil has been suggested, as PDE-5 is enriched in the uterus, and its antagonism could improve uteroplacental function. Here, we report in the reduced uterine perfusion pressure (RUPP) rat model that administration of oral sildenafil is effective in attenuating placental ischemia-induced hypertension during gestation. RUPP animals have significantly elevated arterial pressure compared with control animals (132 ± 3 vs. 100 ± 2 mmHg; P PDE-5/β-actin ratio (1 ± 0.14 vs. 1.63 ± 0.18; P < 0.05) expression with a resulting reduction in renal medullary cGMP (1.5 ± 0.15 vs. 0.99 ± 0.1 pmol/μg protein, P < 0.05) compared with controls. Although sildenafil had no effect on renal medullary cGMP in control animals, it significantly increased cGMP in RUPP animals (1.3 ± 0.1 pmol/μg protein; P < 0.05). These data suggest that sildenafil might provide an effective therapeutic option for the management of hypertension during preeclampsia. PMID:23785075

  6. 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.

  7. Post-Retrieval Extinction Attenuates Cocaine Memories

    OpenAIRE

    Sartor, Gregory C.; Aston-Jones, Gary

    2013-01-01

    Recent studies have shown that post-retrieval extinction training attenuates fear and reward-related memories in both humans and rodents. This noninvasive, behavioral approach has the potential to be used in clinical settings to treat maladaptive memories that underlie several psychiatric disorders, including drug addiction. However, few studies to date have used a post-retrieval extinction approach to attenuate addiction-related memories. In the current study, we attempted to disrupt cocaine...

  8. Brucellosis: The Case for Live, Attenuated Vaccines

    OpenAIRE

    Ficht, Thomas A.; Kahl-McDonagh, Melissa M.; Arenas-Gamboa, Angela M.; Rice-Ficht, Allison C.

    2009-01-01

    The successful control of animal brucellosis and associated reduction in human exposure has limited the development of human brucellosis vaccines. However, the potential use of Brucella in bioterrorism or biowarfare suggests that direct intervention strategies are warranted. Although the dominant approach has explored the use of live attenuated vaccines, side-effects associated with their use has prevented widespread use in humans. Development of live, attenuated Brucella vaccines that are sa...

  9. Investigation of photon attenuation coefficients for marble

    International Nuclear Information System (INIS)

    The total linear attenuation coefficients μ (cm-1) have been obtained using the XCOM program at photon energies of 1 keV to 1 GeV for six different natural marbles produced in different places in Turkey. The individual contribution of photon interaction processes to the total linear attenuation coefficients for marble has been investigated. The calculated results were also compared with the measurements. The results obtained for marble were also compared with concrete. (note)

  10. 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).

  11. Rain-rate estimates for an attenuating radar

    Science.gov (United States)

    Meneghini, R.

    1978-01-01

    An iterative method has been used to produce rain-rate estimates for an attenuating frequency radar. An infinite number of higher-order estimates are shown to converge in the limit to the Hitschfeld-Bordan solution under certain conditions. An error analysis was performed by a model accounting for the randomness of the radar return power, the k-Z, Z-R relations, and offsets in the radar calibration constant. Since the behavior of the estimates strongly depends on system errors, the choice of the best estimate requires a knowledge of the variance and range of offsets in meteorological data and the calibration constant. As the errors increase, the use of the lower orders avoids significant overpredictions. In order to obtain reliable rain-rate predictions in the presence of realistic errors, an antenna pointing angles away from the horizontal at frequencies in the lower end of the X-band may be used. Such antenna configurations insure low attenuation.

  12. 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.

  13. 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...

  14. 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...

  15. Attenuation of cosmogenic 10Be production in the first 20 cm below a rock surface

    International Nuclear Information System (INIS)

    Cosmogenic 10Be has been measured in short drill cores taken from a glacially polished cliff surface. The high-resolution concentration depth profile is compared to theoretical profiles of various attenuation lengths and different shapes near the surface. Preliminary modeling results shows that long apparent attenuation lengths and perhaps a non-decreasing or 'flat' section right below the surface are best suited to bring experiment and theory into agreement

  16. 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.

  17. 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.

  18. The ultraviolet attenuation law in backlit spiral galaxies

    Energy Technology Data Exchange (ETDEWEB)

    Keel, William C. [Department of Physics and Astronomy, University of Alabama, Box 870324, Tuscaloosa, AL 35487 (United States); Manning, Anna M. [Stennis Space Center, MS 39522 (United States); Holwerda, Benne W. [ESA-ESTEC, Keplerlaan 1, 2201-AZ Noordwijk (Netherlands); Lintott, Chris J. [Astrophysics, Oxford University, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Schawinski, Kevin, E-mail: wkeel@ua.edu, E-mail: ammanning@bama.ua.edu, E-mail: bholwerd@rssd.esa.int, E-mail: Twitter@BenneHolwerda, E-mail: cjl@astro.ox.ac.uk, E-mail: Twitter@chrislintott, E-mail: kevin.schawinski@phys.ethz.ch, E-mail: Twitter@kevinschawinski [Institute for Astronomy, ETH Zürich, Wolfgang-Pauli-Strasse 27, CH-8093 Zurich (Switzerland)

    2014-02-01

    The effective extinction law (attenuation behavior) in galaxies in the emitted ultraviolet (UV) regime is well known only for actively star-forming objects and combines effects of the grain properties, fine structure in the dust distribution, and relative distributions of stars and dust. We use Galaxy Evolution Explorer, XMM Optical Monitor, and Hubble Space Telescope (HST) data to explore the UV attenuation in the outer parts of spiral disks which are backlit by other UV-bright galaxies, starting with the candidate list of pairs provided by Galaxy Zoo participants. New optical images help to constrain the geometry and structure of the target galaxies. Our analysis incorporates galaxy symmetry, using non-overlapping regions of each galaxy to derive error estimates on the attenuation measurements. The entire sample has an attenuation law across the optical and UV that is close to the Calzetti et al. form; the UV slope for the overall sample is substantially shallower than found by Wild et al., which is a reasonable match to the more distant galaxies in our sample but not to the weighted combination including NGC 2207. The nearby, bright spiral NGC 2207 alone gives an accuracy almost equal to the rest of our sample, and its outer arms have a very low level of foreground starlight. Thus, this widespread, fairly 'gray' law can be produced from the distribution of dust alone, without a necessary contribution from differential escape of stars from dense clouds. Our results indicate that the extrapolation needed to compare attenuation between backlit galaxies at moderate redshifts from HST data, and local systems from Sloan Digital Sky Survey and similar data, is mild enough to allow the use of galaxy overlaps to trace the cosmic history of dust in galaxies. For NGC 2207, HST data in the near-UV F336W band show that the covering factor of clouds with small optical attenuation becomes a dominant factor farther into the UV, which opens the possibility that

  19. The ultraviolet attenuation law in backlit spiral galaxies

    International Nuclear Information System (INIS)

    The effective extinction law (attenuation behavior) in galaxies in the emitted ultraviolet (UV) regime is well known only for actively star-forming objects and combines effects of the grain properties, fine structure in the dust distribution, and relative distributions of stars and dust. We use Galaxy Evolution Explorer, XMM Optical Monitor, and Hubble Space Telescope (HST) data to explore the UV attenuation in the outer parts of spiral disks which are backlit by other UV-bright galaxies, starting with the candidate list of pairs provided by Galaxy Zoo participants. New optical images help to constrain the geometry and structure of the target galaxies. Our analysis incorporates galaxy symmetry, using non-overlapping regions of each galaxy to derive error estimates on the attenuation measurements. The entire sample has an attenuation law across the optical and UV that is close to the Calzetti et al. form; the UV slope for the overall sample is substantially shallower than found by Wild et al., which is a reasonable match to the more distant galaxies in our sample but not to the weighted combination including NGC 2207. The nearby, bright spiral NGC 2207 alone gives an accuracy almost equal to the rest of our sample, and its outer arms have a very low level of foreground starlight. Thus, this widespread, fairly 'gray' law can be produced from the distribution of dust alone, without a necessary contribution from differential escape of stars from dense clouds. Our results indicate that the extrapolation needed to compare attenuation between backlit galaxies at moderate redshifts from HST data, and local systems from Sloan Digital Sky Survey and similar data, is mild enough to allow the use of galaxy overlaps to trace the cosmic history of dust in galaxies. For NGC 2207, HST data in the near-UV F336W band show that the covering factor of clouds with small optical attenuation becomes a dominant factor farther into the UV, which opens the possibility that

  20. 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.