WorldWideScience

Sample records for effective beta particle

  1. An application of Brookhaven National Laboratory's hot particle methodology for determining the most effective beta particle energy in causing skin ulcers

    International Nuclear Information System (INIS)

    Schaefer, C.

    1994-11-01

    The purpose of this project was to compare the effectiveness of hot particles with different energy betas in producing ulcers on skin. The sources were man-made hot particles similar in size and activity to those found in the commercial nuclear power industry. Four different particle types were used. These were thulium (Tm-170) with a 0.97 MeV maximum energy beta, ytterbium (Yb-175) with a maximum beta energy of 0.47 MeV, scandium (Sc-46) with a 0.36 MeV beta, which was used as a surrogate for cobalt-60 (0.31 MeV beta) and uranium (in the carbide form) with an average maximum beta energy of about 2.5 MeV. Since higher energy beta particles penetrate further in skin, they will affect a higher number and different populations of target cells. The experiments were designed as threshold studies such that the dose needed to produce ulcers ten percent of the time (ED 10%) for each particle type could be compared against each other

  2. An application of Brookhaven National Laboratory`s hot particle methodology for determining the most effective beta particle energy in causing skin ulcers

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, C.

    1994-11-01

    The purpose of this project was to compare the effectiveness of hot particles with different energy betas in producing ulcers on skin. The sources were man-made hot particles similar in size and activity to those found in the commercial nuclear power industry. Four different particle types were used. These were thulium (Tm-170) with a 0.97 MeV maximum energy beta, ytterbium (Yb-175) with a maximum beta energy of 0.47 MeV, scandium (Sc-46) with a 0.36 MeV beta, which was used as a surrogate for cobalt-60 (0.31 MeV beta) and uranium (in the carbide form) with an average maximum beta energy of about 2.5 MeV. Since higher energy beta particles penetrate further in skin, they will affect a higher number and different populations of target cells. The experiments were designed as threshold studies such that the dose needed to produce ulcers ten percent of the time (ED 10%) for each particle type could be compared against each other.

  3. Beta delayed particle emission in light nuclei

    International Nuclear Information System (INIS)

    Riisager, K.; Gabelmann, H.

    1991-01-01

    A short discussion of theoretical treatments of beta delayed particle emission is followed by a presentation of data on the newly found beta delayed deuteron decay of 6 He. This decay cannot be described properly with existing theories. (author) 8 refs.; 3 figs

  4. Beta particle energy spectra shift due to self-attenuation effects in environmental sources

    Directory of Open Access Journals (Sweden)

    Thomas Theakston Alton

    2017-10-01

    Full Text Available In order to predict and control the environmental and health impacts of ionizing radiation in environmental sources such as groundwater, it is necessary to identify the radionuclides present. Beta-emitting radionuclides are frequently identified by measuring their characteristic energy spectra. The present work shows that self-attenuation effects from volume sources result in a geometry-dependent shift in the characteristic spectra, which needs to be taken into account in order to correctly identify the radionuclides present. These effects are shown to be compounded due to the subsequent shift in the photon spectra produced by the detector, in this case an inorganic solid scintillator (CaF2:Eu monitored using a silicon photomultiplier. Using tritiated water as an environmentally relevant, and notoriously difficult to monitor case study, analytical predictions for the shift in the energy spectra as a function of depth of source have been derived. These predictions have been validated using Geant4 simulations and experimental results measured using bespoke instrumentation.

  5. Problems at the Development of personal Beta-particle dosemeters-Beta Particle dosemeters-

    International Nuclear Information System (INIS)

    Helmstadter, K.; Ambrosi, P.

    2002-01-01

    Workplaces at which beta radiation might significantly contribute to the doses to the extremities are increasingly found in radiation therapy, radiation source production and nuclear plants. for the measurement of the individual beta-particle dose, personal dosemeters for fingers, arms and legs are needed. Intercomparison measurements organised from 1996 by the PTB have shown that some dosemeter types based on TLD are suitable for this purpose and can be used as legal dosemeters for both photon and beta radiation. Also, some electronic personal photon dosemeters are investigated in beta radiation fields. it turned out that a few types are also sensitive to beta radiation and measure the personal dose equivalent rate to the skin with a low energy dependence. Only their wearing position is by far not optimal foe extremity dosimetry because they are worn on the chest. Advantages and disadvantages are discussed. The characterisation of workplaces is carried out by measuring dose profiles using area dosemeters. Investigations performed with several commercial types of these dosemeters furnish information about the selection of the suitable measuring device and its correct practical use. the development of improved dosemeters has to towards smaller detectors and higher sensitivity. Personal dosemeters have to be robust and acceptable to the user, which generally is not achieved for beta extremity dosemeters. It is an additional problem that even such dosemeters cannot always be worn in the appropriate place. (Author)

  6. Beta-particle dosimetry in radiation synovectomy

    International Nuclear Information System (INIS)

    Johnson, L.S.; Barnes, C.L.; Spitzer, A.I.; Sledge, C.B.

    1995-01-01

    Beta-particle dosimetry of various radionuclides used in the treatment of rheumatoid arthritis was estimated using Monte Carlo radiation transport simulation coupled with experiments using reactor-produced radionuclides and radiachromic film dosimeters inserted into joint phantoms and the knees of cadavers. Results are presented as absorbed dose factors (cGy-cm 2 /MBq-s) versus depth in a mathematical model of the rheumatoid joint which includes regions of bone, articular cartilage, joint capsule, and tissue (synovium) found in all synovial joints. The factors can be used to estimate absorbed dose and dose rate distributions in treated joints. In particular, guidance is provided for those interested in (a) a given radionuclide's therapeutic range, (b) the amount of radioactivity to administer on a case-by-case basis, (c) the expected therapeutic dose to synovium, and (d) the radiation dose imparted to other, nontarget components in the joint, including bone and articular cartilage. (orig.). With 6 figs., 6 tabs

  7. Effects of 17Beta-estradiol on cognitive performance of ovariectomized female rats exposed to 56Fe particles

    Science.gov (United States)

    On exploratory class missions to other planets astronauts will be exposed to types and doses of radiation (HZE particles) that are not experienced in low earth orbit. While it is likely that the crew will consist of both male and female astronauts, there has been little research on the effects of ...

  8. Hot beta particles in the lung: Results from dogs exposed to fission product radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, F.F.; Griffith, W.C.; Hobbs, C.H. [and others

    1995-12-01

    The Chernobyl nuclear reactor accident resulted in the release of uranium dioxide fuel and fission product radionuclides into the environment with the fallout of respirable, highly radioactive particles that have been termed {open_quotes}hot beta particles.{close_quotes} There is concern that these hot beta particles (containing an average of 150-20,000 Bq/particle), when inhaled and deposited in the lung, may present an extraordinary hazard for the induction of lung cancer. We reviewed data from a group of studies in dogs exposed to different quantities of beta-emitting radionuclides with varied physical half-lives to determine if those that inhaled hot beta particles were at unusual risk for lung cancer. This analysis indicates that the average dose to the lung is adequate to predict biologic effects of lung cancer for inhaled beta-emitting radionuclides in the range of 5-50 Gy to the lung and with particle activities in the range of 0.10-50 Bq/particle.

  9. Kinematic shifts of beta -delayed particles as a probe of beta - nu angular correlations

    CERN Document Server

    Clifford, E T H; Evans, H C; Fästermann, T; Hagberg, E; Hardy, J C; Jackson, K P; Koslowsky, V T; Schmeing, H; Schrewe, U J

    1981-01-01

    Beta-delayed particles undergo a kinematic shift in energy due to recoil motion of the daughter nucleus following beta decay. A careful measurement of this energy shift can be used to establish the ratio of vector to axial vector components in beta transitions. Alpha-beta coincidence data for the beta-delayed alpha decay of /sup 20/Na have been obtained. Component ratios for 6 transitions including the superallowed branch are found. Limits on charge dependent mixing with the analogue state are deduced for 5 states in /sup 20/Ne*. For the superallowed branch the axial vector component is found; the polar vector component is deduced and establishes a value for the vector weak coupling constant of G/sub V/=(1.355+or-0.036)*10/sup -49/ erg cm /sup 3/. (13 refs).

  10. Program BETA for simulation of particle decays and reactions

    International Nuclear Information System (INIS)

    Takhtamyshev, G.G.; Merkulova, T.A.

    1997-01-01

    Program BETA is designed for simulation of particle decays and reactions. The program also produces integration over the phase space and decay rate or the reaction cross section are calculated as a result of such integration. At the simulation process the adaptive random number generator SMART may be used, what is found to be useful for some difficult cases

  11. New data on the self-absorption of betas in cobalt-60 hot particles

    International Nuclear Information System (INIS)

    Lantz, M.W.; Steward, J.B.

    1988-01-01

    The authors demonstrated that standard dose calculation methods for hot particles could seriously overestimate the beta dose rate component to skin. The reason-self-absorption within an activated satellite particle that has a finite thickness can lead to dramatic reductions in beta output, as compared to that predicted by calculation models that assume the particle has zero thickness. In this paper, the authors demonstrate the self-absorption effect with a particle model and confirmed it with measurements on two high-activity Co-60 particles found at the Palo Verde Nuclear Power Station. The authors then described a method for using an Eberline RO-2 ion chamber survey instrument to estimate the beta dose rate reduction related to self-absorption within a particle. This method relied on the comparison of the uncorrected beta/gamma ratio [(open window-closed window) divided-by closed window] for a particle expected of exhibiting self-absorption to the ratio obtained for a particle of zero thickness

  12. SCALING PARAMETERS FOR HOT-PARTICLE BETA DOSIMETRY.

    Science.gov (United States)

    Mangini, Colby D; Hamby, David M

    2016-12-01

    Scaling of dose-point kernel (DPK) values for beta particles transmitted by high-Z sources will overestimate dose at shallow depths while underestimating dose at greater depths due to spectral hardening. A new model has been developed based on a determination of the amount of monoenergetic electron absorption that occurs in a given source thickness through the use of EGSnrc (Electron Gamma Shower) Monte Carlo simulations. Integration over a particular beta spectrum provides the beta-particle DPK following self-absorption as a function of source thickness and radial depth in water, thereby accounting for spectral hardening that may occur in higher-Z materials. Beta spectra of varying spectral shapes and endpoint energies were used to test the model for select source materials with 7.42 ≤ Z ≤ 94. The results demonstrate that significant improvements can be made to DPK-based dosimetry models when dealing with high-Z volumetric sources. This new scaling model is currently being used to improve the accuracy of the beta-dosimetry calculations in VARSKIN 5. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Fusion alpha-particle losses in a high-beta rippled tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Bunno, M.; Nakamura, Y. [Graduate School of Energy Science, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Suzuki, Y. [National Institute for Fusion Science, Toki 509-5292 (Japan); Shinohara, K.; Matsunaga, G. [Japan Atomic Energy Agency, Naka, Ibaraki 311-0193 (Japan); Tani, K. [Nippon Advanced Technology, Naka, Ibaraki 311-0102 (Japan)

    2013-08-15

    In tokamak plasmas, the confinement of energetic ions depends on the magnetic field structure. If the plasma pressure is finite, the equilibrium current (i.e., the Pfirsch-Schlüter current and diamagnetic current) flows in the plasma to maintain the magnetohydrodynamic (MHD) equilibrium. These plasma currents generate poloidal and toroidal magnetic field and alter the field structure. Moreover, if we consider the non-axisymmetry of magnetic field structures such as toroidal field (TF) ripples, the non-axisymmetric component of the equilibrium current can alter TF ripples themselves. When the plasma beta becomes high, the changes in the field structure due to the equilibrium current might affect the confinement of energetic ions significantly. We intend to clarify how these currents alter the field structure and affect the confinement of alpha particles in high-beta plasma. The MHD equilibrium is calculated using VMEC and the orbits of fusion alpha particles are followed by using the fully three-dimensional magnetic field orbit-following Monte Carlo code. In relatively low-beta plasma (e.g., the volume-averaged beta value <β>≤2%), the changes in the magnetic field component due to the plasma current negligibly affect the confinement of alpha particles except for the Shafranov shift effect. However, for <β>≥3%, the diamagnetic effect reduces the magnetic field strength and significantly increases alpha-particle losses. In these high-beta cases, the non-axisymmetric field component generated by the equilibrium current also increases these losses, but not as effectively as compared to the diamagnetic effect.

  14. Radiosensitivity of Prostate Cancer Cell Lines for Irradiation from Beta Particle-emitting Radionuclide ¹⁷⁷Lu Compared to Alpha Particles and Gamma Rays.

    Science.gov (United States)

    Elgqvist, Jörgen; Timmermand, Oskar Vilhelmsson; Larsson, Erik; Strand, Sven-Erik

    2016-01-01

    The purpose of the present study was to investigate the radiosensitivity of the prostate cancer cell lines LNCaP, DU145, and PC3 when irradiated with beta particles emitted from (177)Lu, and to compare the effect with irradiation using alpha particles or gamma rays. Cells were irradiated with beta particles emitted from (177)Lu, alpha particles from (241)Am, or gamma rays from (137)Cs. A non-specific polyclonal antibody was labeled with (177)Lu and used to irradiate cells in suspension with beta particles. A previously described in-house developed alpha-particle irradiator based on a (241)Am source was used to irradiate cells with alpha particles. External gamma-ray irradiation was achieved using a standard (137)Cs irradiator. Cells were irradiated to absorbed doses equal to 0, 0.5, 1, 2, 4, 6, 8, or 10 Gy. The absorbed doses were calculated as mean absorbed doses. For evaluation of cell survival, the tetrazolium-based WST-1 assay was used. After irradiation, WST-1 was added to the cell solutions, incubated, and then measured for level of absorbance at 450 nm, indicating the live and viable cells. LNCaP, DU145, and PC3 cell lines all had similar patterns of survival for the different radiation types. No significant difference in surviving fractions were observed between cells treated with beta-particle and gamma-ray irradiation, represented for example by the surviving fraction values (mean±SD) at 2, 6, and 10 Gy (SF2, SF6, and SF10) for DU145 after beta-particle irradiation: 0.700±0.090, 0.186±0.050 and 0.056±0.010, respectively. A strong radiosensitivity to alpha particles was observed, with SF2 values of 0.048±0.008, 0.018±0.006 and 0.015±0.005 for LNCaP, DU145, and PC3, respectively. The surviving fractions after irradiation using beta particles or gamma rays did not differ significantly at the absorbed dose levels and dose rates used. Irradiation using alpha particles led to a high level of cell killing. The results show that the beta-particle emitter

  15. High beta plasma observations in Earth's Ring Current: Waves and particle oscillations, and drift-mirror instability.

    Science.gov (United States)

    Soto-chavez, A. R.; Lanzerotti, L. J.; Cohen, R. J.; Gerrard, A. J.; Manweiler, J. W.; Kim, H.

    2016-12-01

    We report on high beta ( > 1) plasma observations made by the RBSPICE instruments onboard the Van Allen Probes spacecraft. The data presented covers almost two years of continuous measurements (March 9, 2013 to December 31, 2014). This coverage provides an unprecedented opportunity to identify and characterize high-beta plasma occurrences in the inner magnetosphere and their characteristics. It is known that high-beta events involve complex plasma physics dynamics. These events can also have global effects on Earth's magnetosphere. Here we show that on July 6, 2013 (one of many high-beta events) a Pc5 (˜ 2.5 min period) wave was locally generated in the magnetosphere through the drift-mirror instability. We describe the wave characteristics and its effects on particle modulations, specifically ring current ions (˜ 50-500 keV).

  16. Heat shock protein-90-beta facilitates enterovirus 71 viral particles assembly

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Robert Y.L., E-mail: yuwang@mail.cgu.edu.tw [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Kuo, Rei-Lin [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Medical Biotechnology and Laboratory Science and Graduate Program of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Ma, Wei-Chieh [Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Huang, Hsing-I [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Medical Biotechnology and Laboratory Science and Graduate Program of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Yu, Jau-Song [Department of Cell and Molecular Biology, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Molecular Medicine Research Center, Chang Gung University, Tao-Yuan 333, Taiwan (China); Yen, Sih-Min [Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Huang, Chi-Ruei [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333 Taiwan (China); Shih, Shin-Ru [Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China); Department of Medical Biotechnology and Laboratory Science and Graduate Program of Biomedical Sciences, College of Medicine, Chang Gung University, Tao-Yuan 333, Taiwan (China)

    2013-09-01

    Molecular chaperones are reported to be crucial for virus propagation, but are not yet addressed in Human Enterovirus 71 (EV71). Here we describe the specific association of heat shock protein-90-beta (Hsp90β), but not alpha form (Hsp90α), with EV71 viral particles by the co-purification with virions using sucrose density gradient ultracentrifugation, and by the colocalization with viral particles, as assessed by immunogold electron microscopy. The reduction of the Hsp90β protein using RNA interference decreased the correct assembly of viral particles, without affecting EV71 replication levels. Tracking ectopically expressed Hsp90β protein associated with EV71 virions revealed that Hsp90β protein was transmitted to new host cells through its direct association with infectious viral particles. Our findings suggest a new antiviral strategy in which extracellular Hsp90β protein is targeted to decrease the infectivity of EV71 and other enteroviruses, without affecting the broader functions of this constitutively expressed molecular chaperone. - Highlights: • Hsp90β is associated with EV71 virion and is secreted with the release virus. • Hsp90β effects on the correct assembly of viral particles. • Viral titer of cultured medium was reduced in the presence of geldanamycin. • Viral titer was also reduced when Hsp90β was suppressed by siRNA treatment. • The extracellular Hsp90β was also observed in other RNA viruses-infected cells.

  17. Heat shock protein-90-beta facilitates enterovirus 71 viral particles assembly

    International Nuclear Information System (INIS)

    Wang, Robert Y.L.; Kuo, Rei-Lin; Ma, Wei-Chieh; Huang, Hsing-I; Yu, Jau-Song; Yen, Sih-Min; Huang, Chi-Ruei; Shih, Shin-Ru

    2013-01-01

    Molecular chaperones are reported to be crucial for virus propagation, but are not yet addressed in Human Enterovirus 71 (EV71). Here we describe the specific association of heat shock protein-90-beta (Hsp90β), but not alpha form (Hsp90α), with EV71 viral particles by the co-purification with virions using sucrose density gradient ultracentrifugation, and by the colocalization with viral particles, as assessed by immunogold electron microscopy. The reduction of the Hsp90β protein using RNA interference decreased the correct assembly of viral particles, without affecting EV71 replication levels. Tracking ectopically expressed Hsp90β protein associated with EV71 virions revealed that Hsp90β protein was transmitted to new host cells through its direct association with infectious viral particles. Our findings suggest a new antiviral strategy in which extracellular Hsp90β protein is targeted to decrease the infectivity of EV71 and other enteroviruses, without affecting the broader functions of this constitutively expressed molecular chaperone. - Highlights: • Hsp90β is associated with EV71 virion and is secreted with the release virus. • Hsp90β effects on the correct assembly of viral particles. • Viral titer of cultured medium was reduced in the presence of geldanamycin. • Viral titer was also reduced when Hsp90β was suppressed by siRNA treatment. • The extracellular Hsp90β was also observed in other RNA viruses-infected cells

  18. Null functions in three-dimensional imaging of alpha and beta particles.

    Science.gov (United States)

    Ding, Yijun; Caucci, Luca; Barrett, Harrison H

    2017-11-17

    Null functions of an imaging system are functions in the object space that give exactly zero data. Hence, they represent the intrinsic limitations of the imaging system. Null functions exist in all digital imaging systems, because these systems map continuous objects to discrete data. However, the emergence of detectors that measure continuous data, e.g. particle-processing (PP) detectors, has the potential to eliminate null functions. PP detectors process signals produced by each particle and estimate particle attributes, which include two position coordinates and three components of momentum, as continuous variables. We consider Charged-Particle Emission Tomography (CPET), which relies on data collected by a PP detector to reconstruct the 3D distribution of a radioisotope that emits alpha or beta particles, and show empirically that the null functions are significantly reduced for alpha particles if ≥3 attributes are measured or for beta particles with five attributes measured.

  19. BETA DOSE RATES FROM NEUTRON-IRRADIATED URANIUM-235 CARBIDE PARTICLES,

    Science.gov (United States)

    Small highly radioactive particles could be injected into the biosphere from the re-entry and burnup of a nuclear propulsion reactor. This would...using tissue equivalent electrodes. The beta dose from the irradiated particles delivered to a segment of tissue can be calculated using a rate law derived from the experimental values.

  20. Monte Carlo simulation of beta particle-induced bremsstrahlung doses.

    Science.gov (United States)

    Mrdja, D; Bikit, K; Bikit, I; Slivka, J; Forkapic, S; Knezevic, J

    2018-03-01

    It is well known that protection from the external irradiation produced by beta emitters is simpler than the corresponding shielding of radioactive sources that emit gamma radiation. This is caused by the relatively strong absorption (i.e. short range) of electrons in different materials. However, for strong beta sources specific attention should be paid to the bremsstrahlung radiation induced in the source encapsulation (matrix), especially for emitters with relatively high beta-endpoint energy (1 MeV) that are frequently used in nuclear medicine. In the present work, the bremsstrahlung spectra produced in various materials by the following beta emitters, Sr-90 (together with its daughter Y-90), P-32 and Bi-210, were investigated by Monte Carlo simulations using Geant4 software. In these simulations, it is supposed that the point radioactive sources are surrounded by cylindrically shaped capsules made from different materials: Pb, Cu, Al, glass and plastic. For the case of Y-90(Sr-90) in cylindrical lead and aluminum capsules, the dimensions of these capsules have also been varied. The absorbed dose rates from bremsstrahlung radiation were calculated for cases where the encapsulated point source is placed at a distance of 30 mm from the surface of a water cylinder with a mass of 75 kg (approximately representing the human body). The bremsstrahlung dose rate and bremsstrahlung spectrum from the Y-90(Sr-90) point source encapsulated in an Al capsule were also measured experimentally and compared with the corresponding simulation results. In addition, the bremsstrahlung radiation risk for medical staff in therapies using Y-90 was considered in simulations, relating to finger dose as well as whole-body dose during preparation and injection of this radioisotope. The corresponding annual doses were obtained for medical workers for specified numbers of Y-90 applications to patients.

  1. The Inertia Weight Updating Strategies in Particle Swarm Optimisation Based on the Beta Distribution

    Directory of Open Access Journals (Sweden)

    Petr Maca

    2015-01-01

    Full Text Available The presented paper deals with the comparison of selected random updating strategies of inertia weight in particle swarm optimisation. Six versions of particle swarm optimization were analysed on 28 benchmark functions, prepared for the Special Session on Real-Parameter Single Objective Optimisation at CEC2013. The random components of tested inertia weight were generated from Beta distribution with different values of shape parameters. The best analysed PSO version is the multiswarm PSO, which combines two strategies of updating the inertia weight. The first is driven by the temporally varying shape parameters, while the second is based on random control of shape parameters of Beta distribution.

  2. Development of a Cerenkov radiation sensor to detect low-energy beta-particles.

    Science.gov (United States)

    Yoo, Wook Jae; Han, Ki-Tek; Shin, Sang Hun; Seo, Jeong Ki; Jeon, Dayeong; Lee, Bongsoo

    2013-11-01

    We fabricated a novel fiber-optic Cerenkov radiation sensor using a Cerenkov radiator for measuring beta-particles. Instead of employing a scintillator, transparent liquids having various refractive indices were used as a Cerenkov radiator to serve as a sensing material. The experimental results showed that the amount of Cerenkov radiation due to the interaction with beta-particles increased as the refractive index of the Cerenkov radiator was increased as a results of a decrease of the Cerenkov threshold energy for electrons. © 2013 Elsevier Ltd. All rights reserved.

  3. Alpha and beta particle induced scintillations in liquid and solid neon

    CERN Document Server

    Michniak, R A; McKinsey, D N; Doyle, J M

    2002-01-01

    Scintillations induced by alpha and beta particles in liquid and solid neon are studied and their light yield measured. Charged particle scintillation in neon is primarily in the extreme ultraviolet (EUV). We detect this EUV light by converting it to blue using a wavelength shifting fluor and detecting the blue light with a photomultiplier tube. It is observed that liquid neon is a somewhat less-efficient scintillator than liquid helium for both alpha and beta radiation while the light yield in solid neon is greater than in liquid helium. Based on our measurements of the relative light yields of liquid and solid neon to liquid helium whose absolute light yield has previously been determined, we find that an alpha source in liquid neon produces up to 5900 photons per MeV while a beta source produces up to 7400 photons per MeV. In solid neon, we find that an alpha particle produces up to 9300 photons per MeV while a beta particle produces up to 17,000 photons per MeV. We observe a significant dependence of the ...

  4. Heavy particle effects

    International Nuclear Information System (INIS)

    Yao, Y.P.

    1981-01-01

    There are two problems discussed, both of which have to do with dissimilar magnitudes in mass. Theoretically, we can devise the large difference in mass as observed by decreeing some vev, v/sub i/ to be much bigger than the other; or, we can assume that some couplings g/sub i/ are much stronger. These two different assumptions give rise to entirely different patterns of interaction in the resulting theory. The first way to generate a mass hierarchy can be called the soft way, because in the zeroth order, the large mass scale leaves its foot print merely in a few effective parameters of the residual theory. The effective theory is renormalizable, sans anomaly. In this limit, the heavy particles decouple. The second assumption (g/sub j/ much greater than g/sub j'/) to create mass hierarchy does a lot of violence to a theory. Effects of the large mass scale will be felt by the system left behind in many ways. An infinite number of parameters are needed to summarize the effects in this limit. This is called the hard limit. It follows that the resulting effective Lagrangian, if in fact it makes sense to construct one at all, will be non-polynomial and apparently non-renormalizable

  5. Near-infrared turbidity of beta-FeOOH particle suspensions

    International Nuclear Information System (INIS)

    Berdahl, P.; Espinoza, L.H.; Littlejohn, D.; Lucas, D.; Perry, D.L.

    1999-01-01

    Near-infrared transmission spectroscopy can be complicated by the light scattering from heterogeneous materials. To examine an evolving system exhibiting such light scattering, transmission spectra are obtained during the hydrolysis of iron chloride solutions. At first, the resulting turbid suspension of cigar-shaped beta-FeOOH particles exhibits single-particle scattering, including a Rayleigh regime (attenuation proportional to the fourth power of the wavenumber). At later times, the scattering increases strongly as the particles aggregate, and becomes proportional to the wavenumber squared, consistent with scattering models which interpret the structure of aggregates in terms of a fractal dimension roughly equal to 2

  6. Accounting for the self-absorption of betas in cobalt-60 hot particles

    International Nuclear Information System (INIS)

    Lantz, M.W.; Steward, J.B.

    1988-01-01

    This paper reports that the assumptions used dose calculations can be overly conservative for discrete hot particles (activated satellite chips and irradiated fuel fragments) due to self-absorption of betas within the particles. Using data from tests with a Co-60 hot particle, a model is developed to estimate the dose reduction factor afforded by self-absorption in a satellite chip with a known thickness. The model can be applied indirectly using ion chamber survey instrument readings (the thickness of the particle does not have to be measured). Tests with Co-60 particles found at the Palo Verde Nuclear Generating Station verify that self-absorption is significant -- in one case, a dose reduction factor of 7 was measured in a satellite chip with a visible thickness

  7. The radiological significance of beta emitting hot particles released from the Chernobyl nuclear power plant

    International Nuclear Information System (INIS)

    Hofmann, W.; Crawford-Brown, D.J.; Martonen, T.B.

    1988-01-01

    In order to assess radiological hazards associated with inhalation of beta emitting hot particles detected in fall-out from the Chernobyl incident, radiation doses and lung cancer risk are calculated for a hot particle composed entirely of 103 Ru. Lung cancer risk estimates are based upon an initiation-promotion model of carcinogenesis. In the immediate vicinity of a hot particle, calculations indicate that doses may be extremely high, so that all cells are killed and no tumour will arise. At intermediate distances, however, the probability for lung cancer induction exhibits a distinct maximum. Risk enhancement factors, computed relative to a uniform radionuclide distribution of equal activity, are highest for intermediate activities and hot particles moving in the lung. While the risk from inhalation of 103 Ru hot particles might, indeed, exceed that from all other exposure pathways of the Chernobyl fall-out, it still lies within normal fluctuations of radon progeny induced lung cancer risk. (author)

  8. Double beta decays and related subjects for particle and nuclear physics

    International Nuclear Information System (INIS)

    Ejiri, Hiroyasu

    1991-01-01

    Present status and some perspectives in 1990's are briefly given on double beta decays and related subjects. Subjects discussed are as follows I) Double beta decays without neutrinos, which require lepton number non-conservations and finite neutrino mass. II) Double beta decays followed by two neutrinos. III) Double weak processes with strangeness change ΔS = 2, leading to the H particle with 6 quarks of ss uu dd. IV) Charge non-conservation and electron decays. These are very rare nuclear processes studied by Ultra RAre-process NUclear Spectroscopy (URANUS). It is shown that URANUS is an important detector frontier of non-accelerator nuclear physics in 1990's. (orig.)

  9. Thermoluminescence of europium-doped zinc oxide exposed to beta particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Iriqui R, J. L.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R. [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83000 Hermosillo, Sonora (Mexico); Castano, V. M., E-mail: jorgeiriqui@gimmunison.com [UNAM, Instituto de Fisica, Centro de Fisica Aplicada y Tecnologia Avanzada, Apdo. Postal 1-1010, 76000 Queretaro, Qro. (Mexico)

    2015-10-15

    Full text: Zn O is a promising material for a range of optoelectronics applications, due to its direct wide band gap (E{sub g} ∼3.3 eV at 300 K) and large exciton binding energy (60 MeV). Its applications include UV light emitters, varistors, surface acoustic wave devices, piezoelectric transducers, and chemical and gas sensing. Rare-earth activation of phosphors has long been seen as an effective process since coupling energy into the rare-earth-ion site, either by ionization, charge exchange or a resonance energy process, results in light production. It is reported that Europium modifies the response thermoluminescence (Tl) for pure zinc oxide, when is irradiated with X-ray, created a peak at 365 degrees C. In this work, Zn O:Eu phosphors were synthesized by a chemical method. Some samples were exposed to beta particle irradiation for doses ranging from 1 up to 100 Gy. Tl response as a function of dose is linear throughout the studied dose range. The glow curve exhibits three maxima, centered at 176, 279 and 340 degrees C. The reusability studies obtained after ten repeated cycles of annealing irradiation readout for the Zn O:Eu shows that the variation in the Tl response is ten percent and tends to stabilization. The results indicate that these new Zn O:Eu phosphors are promising detectors and dosimeters for beta radiation. The structural and morphological characterization was carried out by X-ray diffraction and scanning electron microscopy, respectively. (Author)

  10. The implications of particle energy and acidic media on gross alpha and gross beta determination using liquid scintillation

    Energy Technology Data Exchange (ETDEWEB)

    Zapata-Garcia, D. [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain); Llaurado, M., E-mail: montse.llaurado@ub.edu [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain); Rauret, G. [Laboratori de Radiologia Ambiental (LRA), Departament de Quimica Analitica, Universitat de Barcelona, Marti i Franques, 1-11 Planta 3, E-08028 Barcelona (Spain)

    2012-04-15

    The interaction of humans with radioactivity present in the environment from natural and artificial sources necessitates an evaluation of its risk on human health. Gross alpha and gross beta activities can provide a rapid evaluation of the radioactive content of a sample and can be simultaneously determined by using liquid scintillation counters. However, calibration of the liquid scintillation counter is required and is affected by many factors, such as particle energy and the acidity of the media. This study investigates what effect the particle energy used for calibration has on misclassification and how to account for this misclassification in routine measurements. The variability in measurement produced by the final pH, as well as any acids used in sample treatment, was also studied. These results showed that the most commonly used acid for these types of analyses, HNO{sub 3}, produced a high amount of misclassifications at very low pH. The results improved when HCl was used to adjust the sample to low pH. - Highlights: Black-Right-Pointing-Pointer We study the effect of alpha and beta energies on PSA optimisation. Black-Right-Pointing-Pointer The optimum PSA shifts to higher values as the alpha energy increases. Beta energies do not affect it. Black-Right-Pointing-Pointer We study the effect of pH on the simultaneous determination of gross alpha/beta activities. Black-Right-Pointing-Pointer HNO{sub 3} produces a high amount of misclassification at very low pH. Black-Right-Pointing-Pointer The results improve when HCl is used to adjust the sample to low pH.

  11. Application of the beta-ray absorption method to the measurement of particles in the air

    Energy Technology Data Exchange (ETDEWEB)

    Ise, Hiroaki; Nakamura, Masaru; Maeno, Tomokazu; Tanizaki, Yoshiyuki [Tokyo Metropolitan Isotope Research Center (Japan)

    1996-03-01

    With a view to facilitating the application of the micro-mass measuring technology which utilizes the beta-ray absorption method to the field of measurement of particles in the air, we have developed a multipurpose device to capture and evaluate the particles. It is applicable to a wide range of measurement of particles such as suspended particulate matters (SPM), dust falls and source particles. We have also made a study on its performance. As a result of our study on the material of the filter, which was carried out to improve the accuracy of measurement by beta-ray absorption method taking into consideration the application of such methods as the component analysis by PIXE, it was clarified that the combination of the polycarbonate membrane filter and the glass fiber filter coated with Teflon is excellent in performance. Moreover we also made a study on a simple measuring method of SPM, which will make it possible to measure the mass concentration of captured SPM even if its amount is very small, based on the data obtained by the automatic measuring device which is always monitoring one hour value of mass concentration of SPM through the beta-ray absorption method. As a result, we found that the combined method of the beta-ray absorption method the laser light scattering method and the filtration capturing/color differential method is excellent. So, we suggested a new measuring method derived from the color differential method and the sensual evaluation method. It will make it possible to measure SPM with an accuracy in the order of microgram. (author)

  12. Modeling early physical and chemical events for DNA damage induced by photons and tritium beta particles

    Energy Technology Data Exchange (ETDEWEB)

    Moiseenko, V. [McMaster Univ., Dept. of Physics and Astronomy, Hamilton, Ontario (Canada); Waker, A.J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Prestwich, W.V. [McMaster Univ., Dept. of Physics and Astronomy, Hamilton, Ontario (Canada)

    1998-02-01

    A method has been developed to model production of single-strand breaks (SSB) and double-strand breaks (DSB) in Deoxyribo Nucleic Acid (DNA) by ionizing radiations. Modeling is carried out by Monte Carlo means and includes consideration of direct energy depositions in DNA molecules, production of chemical species following water radiolysis, diffusion of chemical species, and their interactions with each other and DNA. Computer-generated electron tracks in liquid water are used to model energy deposition and to derive the initial localization of chemical species. Atomistic representation of the DNA with a first hydration shell is used to derive direct energy depositions in DNA molecules and the resulting consequences, and to derive coordinates of reactive sites for modeling of the chemical stage of radiation damage. Diffusion of chemical species is followed in time, and the reactions of species with each other and DNA are considered to occur in an encounter-controlled manner. Time of diffusion follow-up is restricted to 10{sup -12}- 10{sup -9} s, which yields a diffusion length of hydroxyl radicals comparable to that in the cellular environment. DNA SSB are assumed to result from any direct energy depositions in the sugar/phosphate moiety, ionizations in water molecules bound to sugar/phosphate and hydroxyl attacks on deoxyribose. DSB are assumed to result from two SSB on opposite strands separated by 10 or fewer base pairs. Photon radiations in the energy range 70 keV-1 MeV and tritium beta particles are considered. It is shown that for naked DNA in B-form (the configuration thought to be most biologically relevant) the effectiveness of tritium for SSB and DSB production is, within statistical uncertainties, comparable to photon radiation with energies in the range 70 keV-1 MeV, although a tendency for increased DSB production has been observed for 70 keV photons that represent orthovoltage X-rays and for tritium beta particles. It is predicted that hydroxyl

  13. Modeling early physical and chemical events for DNA damage induced by photons and tritium beta particles

    International Nuclear Information System (INIS)

    Moiseenko, V.; Waker, A.J.; Prestwich, W.V.

    1998-02-01

    A method has been developed to model production of single-strand breaks (SSB) and double-strand breaks (DSB) in Deoxyribo Nucleic Acid (DNA) by ionizing radiations. Modeling is carried out by Monte Carlo means and includes consideration of direct energy depositions in DNA molecules, production of chemical species following water radiolysis, diffusion of chemical species, and their interactions with each other and DNA. Computer-generated electron tracks in liquid water are used to model energy deposition and to derive the initial localization of chemical species. Atomistic representation of the DNA with a first hydration shell is used to derive direct energy depositions in DNA molecules and the resulting consequences, and to derive coordinates of reactive sites for modeling of the chemical stage of radiation damage. Diffusion of chemical species is followed in time, and the reactions of species with each other and DNA are considered to occur in an encounter-controlled manner. Time of diffusion follow-up is restricted to 10 -12 - 10 -9 s, which yields a diffusion length of hydroxyl radicals comparable to that in the cellular environment. DNA SSB are assumed to result from any direct energy depositions in the sugar/phosphate moiety, ionizations in water molecules bound to sugar/phosphate and hydroxyl attacks on deoxyribose. DSB are assumed to result from two SSB on opposite strands separated by 10 or fewer base pairs. Photon radiations in the energy range 70 keV-1 MeV and tritium beta particles are considered. It is shown that for naked DNA in B-form (the configuration thought to be most biologically relevant) the effectiveness of tritium for SSB and DSB production is, within statistical uncertainties, comparable to photon radiation with energies in the range 70 keV-1 MeV, although a tendency for increased DSB production has been observed for 70 keV photons that represent orthovoltage X-rays and for tritium beta particles. It is predicted that hydroxyl radicals react

  14. In vivo biotinylation of recombinant beta-glucosidase enables simultaneous purification and immobilization on streptavidin coated magnetic particles

    DEFF Research Database (Denmark)

    Alftrén, Johan; Ottow, Kim Ekelund; Hobley, Timothy John

    2013-01-01

    Beta-glucosidase from Bacillus licheniformis was in vivo biotinylated in Escherichia coli and subsequently immobilized directly from cell lysate on streptavidin coated magnetic particles. In vivo biotinylation was mediated by fusing the Biotin Acceptor Peptide to the C-terminal of beta...

  15. Radiation thickness gauge using beta particle sensitivity controlled open air corona streamer counter

    International Nuclear Information System (INIS)

    Fouad, L.; El-Hazek, S.; El-Araby, S.

    1999-01-01

    Beta particles have been used extensively in radio gauging applications when measurements of foil thicknesses are desired. Using beta particle open air corona streamer counter (point-grid-plane) as a thickness gauge is presented. This gauge consists of two similar counters with two similar Sr-90 beta sources. One counter-source combination is called standard unit, and the other counter-source combination is called measuring unit in which the required foil thickness can be measured by inserting it between the source and the counter. The signals from the counters are amplified with the same gain factor and the net difference between their responses is measured using specially designed electronic circuit. By this way any change that takes place in the operating medium (variation of parameters of open air i.e. temperature, humidity...etc) can similarly affect the two units, the errors in the measurements caused by them are cancelled, and the only response is due to the measured foil thickness. A theoretical model is suggested to explain and analyze the overall response of the gauge system and calculate the calibration thickness gauge constant. All theoretical findings are confirmed by experiments

  16. Health effects of exhaust particles

    Energy Technology Data Exchange (ETDEWEB)

    Pihlava, T.; Uuppo, M.; Niemi, S.

    2013-11-01

    This report introduces general information about diesel particles and their health effects. The purpose of this report is to introduce particulate matter pollution and present some recent studies made regarding the health effects of particulate matter. The aim is not to go very deeply into the science, but instead to keep the text understandable for the average layman. Particulate matter is a complex mixture of extremely small particles and liquid droplets. These small particles are made up of a number of components that include for example acids, such as nitrates and sulphates, as well as organic chemicals, metals and dust particles from the soil. Particulate matter comes from several sources, such as transportation emissions, industrial emissions, forest fires, cigarette smoke, volcanic ash and climate variations. Particles are divided into coarse particles with diameters less than 10 ..m, fine particles with diameters smaller than 2.5 ..m and ultra-fine particles with diameters less than 0.1 ..m. The particulate matter in diesel exhaust gas is a highly complex mixture of organic, inorganic, solid, volatile and partly volatile compounds. Many of these particles do not form until they reach the air. Many carcinogenic compounds have been found in diesel exhaust gas and it is considered carcinogenic to humans. Particulate matter can cause several health effects, such as premature death in persons with heart or lung disease, cancer, nonfatal heart attacks, irregular heartbeat, aggravated asthma, decreased lung function and an increase in respiratory symptoms, such as irritation of the airways, coughing or difficulty breathing. It is estimated that in Finland about 1300 people die prematurely due to particles and the economic loss in the EU due to the health effects of particles can be calculated in the billions. Ultra-fine particles are considered to be the most harmful to human health. Ultrafine particles usually make the most of their quantity and surface area

  17. Applications of Beta Particle Detection for Synthesis and Usage of Radiotracers Developed for Positron Emission Tomography

    Science.gov (United States)

    Dooraghi, Alex Abreu

    Positron Emission Tomography (PET) is a noninvasive molecular imaging tool that requires the use of a radioactive compound or radiotracer which targets a molecular pathway of interest. We have developed and employed three beta particle radiation detection systems to advance PET. Specifically, the goals of these systems are to: 1. Automate dispensing of solutions containing a positron emitting isotope. 2. Monitor radioactivity on-chip during synthesis of a positron emitting radiotracer. 3. Assay cellular uptake on-chip of a positron emitting radiotracer. Automated protocols for measuring and dispensing solutions containing radioisotopes are essential not only for providing an optimum environment for radiation workers, but also to ensure a quantitatively accurate workflow. For the first project, we describe the development and performance of a system for automated radioactivity distribution of beta particle emitting radioisotopes such as fluorine-18 (F-18). Key to the system is a radiation detector in-line with a peristaltic pump. The system demonstrates volume accuracy within 5 % for volumes of 20 muL or greater. When considering volumes of 20 muL or greater, delivered radioactivity is in agreement with the requested radioactivity as measured with the dose calibrator. The integration of the detector and pump leads to a flexible system that can accurately dispense solutions containing F-18 in radioactivity concentrations directly produced from a cyclotron (~ 0.1-1 mCi/muL), to low activity concentrations intended for preclinical mouse scans (~ 1-10 muCi/muL), and anywhere in between. Electrowetting on dielectric (EWOD) is an attractive microfluidic platform for batch synthesis of PET radiotracers. Visualization of radioisotopes on-chip is critical for synthesis optimization and technological development. For the second project, we describe the development and performance of a Cerenkov/real-time imaging system for PET radiotracer synthesis on EWOD. We also investigate

  18. Gallium Arsenide detectors for X-ray and electron (beta particle) spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lioliou, G.; Barnett, A.M.

    2016-11-11

    Results characterizing GaAs p{sup +}-i-n{sup +} mesa photodiodes with a 10 µm i layer for their spectral response under illumination of X-rays and beta particles are presented. A total of 22 devices, having diameters of 200 µm and 400 µm, were electrically characterized at room temperature. All devices showed comparable characteristics with a measured leakage current ranging from 4 nA/cm{sup 2} to 67 nA/cm{sup 2} at an internal electric field of 50 kV/cm. Their unintentionally doped i layers were found to be almost fully depleted at 0 V due to their low doping density. {sup 55}Fe X-ray spectra were obtained using one 200 µm diameter device and one 400 µm diameter device. The best energy resolution (FWHM at 5.9 keV) achieved was 625 eV using the 200 µm and 740 eV using the 400 µm diameter device, respectively. Noise analysis showed that the limiting factor for the energy resolution of the system was the dielectric noise; if this noise was eliminated by better design of the front end of the readout electronics, the achievable resolution would be 250 eV. {sup 63}Ni beta particle spectra obtained using the 200 µm diameter device showed the potential utility of these detectors for electron and beta particle detection. The development of semiconductor electron spectrometers is important particularly for space plasma physics; such devices may find use in future space missions to study the plasma environment of Jupiter and Europa and the predicted electron impact excitation of water vapor plumes from Europa hypothesized as a result of recent Hubble Space Telescope (HST) UV observations.

  19. Physical consequences of the alpha/beta rule which accurately calculates particle masses

    Energy Technology Data Exchange (ETDEWEB)

    Greulich, Karl Otto [Fritz Lipmann Institute, Beutenbergstr.11, D07745 Jena (Germany)

    2015-07-01

    Using the fine structure constant α (=1/137.036), the proton vs. electron mass ratio β (= 1836.2) and the integers m and n, the α/β rule: m{sub particle} = α{sup -n} x β m x 27.2 eV/c{sup 2} allows almost exact calculation of particle masses. (K.O.Greulich, DPG Spring meeting 2014, Mainz, T99.4) With n=2, m=0 the electron mass becomes 510.79 keV/c{sup 2} (experimental 511 keV/c{sup 2}) With n=2, m=1 the proton mass is 937.9 MeV/c{sup 2} (literature 938.3 MeV/c{sup 2}). For n=3 and m=1 a particle with 128.6 GeV/c{sup 2} close to the reported Higgs mass, is expected. For n=14 and m=-1 the Planck mass results. The calculated masses for gauge bosons and for quarks have similar accuracy. All masses fit into the same scheme (the alpha/beta rule), indicating that non of these particle masses play an extraordinary role. Particularly, the Higgs Boson, often termed the *God particle* plays in this sense no extraordinary role. In addition, particle masses are intimately correlated with the fine structure constant α. If particle masses have been constant over all times, α must have been constant over these times. In addition, the ionization energy of the hydrogen atom (13.6 eV) needs to have been constant if particle masses have been unchanged or vice versa. In conclusion, the α/β rule needs to be taken into account when cosmological models are developed.

  20. Study of the $\\beta$-delayed Particle Emission of $^{17}$Ne

    CERN Multimedia

    2002-01-01

    We intend to investigate the charged particle decay modes from the excited states of $^{17}$F populated in the $\\beta^+$- decay of $^{17}$Ne. In particular, we propose to study the proton decay branches to $^{16}$O states which are unstable to $\\alpha$- decay. We plan to use the recently developed ISOLDE Si-ball detector array in order to efficiently detect the charged particles in a wide solid angle. We ask for a total of 12 shifts, including 9 shifts for $^{17}$Ne and 3 shifts for stable beam and calibrations. We request the use of a Mg oxide target coupled to a plasma ion source with cooled transfer line or, if possible, to the new MINIMONOECRIS. We would like to make use of the ISOLDE VME DAQ and CERN data storage system.

  1. The effect of Leiber Beta-S on selected immunity indicators in calves

    Directory of Open Access Journals (Sweden)

    Roman Wójcik

    2014-01-01

    Full Text Available A wide variety of dietary supplements containing polysaccharides are being introduced on the market. One of them is Leiber Beta-S (β-1,3/1,6-D-glucan whose immunostimulatory effects have not yet been fully evaluated, in particular in polygastric animals. The aim of this study was to evaluate the effect of this supplement on selected indicators of cellular and humoral immunity in calves. The experiment was performed on 14 calves aged 30 ± 2 days, divided into two equal groups of control and experimental animals. The feed administered to calves of the experimental group was supplemented with Leiber Beta-S at 50 mg/kg body weight, whereas control calves were administered standard farm-made feed without supplementation. Blood was sampled before the experiment (day 0 and on days 15, 30 and 60 to determine the immunity indicators (proliferative response of lipopolysaccharide- and concanavalin A-stimulated lymphocytes, respiratory burst activity, potential killing activity of phagocytes, gamma globulin concentrations, lysozyme activity, ceruloplasmin activity and biochemical indicator (total protein concentrations. Diet supplemented with Leiber Beta-S stimulated the immune system of calves. Significant differences between the experimental and the control group were found in lysozyme and ceruloplasmin activity, gamma globulin concentrations, potential killing activity of phagocytes, proliferative response of lymphocytes (P P < 0.05. No differences were found in the serum total protein between the experimental and the control group. This study reports for the first time the effect of Leiber Beta-S (β-1,3/1,6-D-glucan on selected biochemical and immunity indicators in calves.

  2. Thermoluminescence of new Cu doped ZnO phosphors exposed to beta particle irradiation

    International Nuclear Information System (INIS)

    Burruel I, S.E.; Cruz V, C.; Grijalva M, H.; Bernal, R.; Castano, V.M.

    2007-01-01

    Full text: Recently, we reported on the striking thermoluminescence (TL), optically stimulated luminescence and afterglow properties of beta particle irradiated ZnO nano phosphors obtained by thermal annealing of chemically synthesized ZnS. In order to improve the general stimulated luminescence characteristics of this new phosphor, we have fabricated new Cu doped ZnO phosphors by carrying out the chemical modification of the chemically deposited ZnS powder with a copper complex before a thermal treatment at 700 C during 24 h under air atmosphere Some samples were exposed to beta particle irradiation in the 0.005 - 2 56 kGy dose range in order to investigate their dosimetric capabilities under ionizing radiation. The Cu ZnO samples exhibited more linear TL response as a function of dose than that obtained by the ZnO phosphors. Moreover, the TL fading features were improved by the doping; for instance, the integrated TL of ZnO samples fades to 42% of its initial value 15 h after irradiation, compared with 84% of the new ZnO:Cu phosphors. The Cu incorporation also seems to be responsible for a change in the TL kinetics, since the TL maximum does not shift with dose, unlike the observed in ZnO samples. (Author)

  3. Ascorbic Acid and Beta-Carotene Alleviate Oxidative Effect of ...

    African Journals Online (AJOL)

    Ascorbic Acid and Beta-Carotene Alleviate Oxidative Effect of London King Size® Cigarette Smoke on Tissue Lipids. ... Malondialdehyde production in the tissues was reduced by ascorbic acid and or beta-carotene given daily to the rats. It is implied that ascorbic acid or ... http://dx.doi.org/10.4314/njhbs.v2i1.11451.

  4. Conformation, molecular packing and field effect mobility of regioregular beta,beta'-dihexylsexithiophiophene

    DEFF Research Database (Denmark)

    Kiriy, N.; Kiriy, A.; Bocharova, V.

    2004-01-01

    by the pulse-radiolysis time-resolved microwave conductivity (PR-TRMC) technique was found to be Sigmamu(min) = 3.9 x 10(-3) cm(2) V-1 s(-1), which is comparable with the PR-TRMC mobility found for alpha,omega-DH6T. The field-effect mobility (FEM) of beta,beta'-DH6T was found to be on the order of 10(-5) cm(2......) V-1 s(-1), which is considerably less than the FEM of alpha,omega-DH6T. To understand the reason for such poor macroscopic electrical properties, the conformation and the molecular packing of beta,beta'-DH6T were systematically studied by means of UV-vis spectroscopy, scanning electron microscopy...... less dense crystalline packing than alpha,omega-DH6T. In contrast to the almost upright orientation of alpha,omega-DH6T molecules against the substrate (tilt angle about 68), the long axis of beta,beta'-DH6T molecules and the surface plane form an angle of similar to20degrees. Thus, the crystalline...

  5. Trend of Gross Beta Radioactivity in Air Particles and Rainwater of around the Domestic Nuclear Power Plants

    International Nuclear Information System (INIS)

    Yeom, Jungmin; Shin, Daeyewn; Kim, Soongpyung; Ju, Sundong; OH, Youngsoo; Kim, Byunggyu; Kim, Sunsik

    2014-01-01

    Investigating items can be distinguished into two parts, regional radiation and concentrations of environmental radioactivity, and in environmental radioactivity, to access the internal exposure dose, gross beta-radioactivity of particles in air and rainwater specimen are being tested. Gross beta-radioactivity quickly shows whether radiation is unusual or no since most of nuclide released in radioactive emergency while operating an atomic energy facility emits beta rays, and the method used to test it is simple. Looking at the years of analyzed results of particles in air and rainwater around the facility for gross beta-radioactivity, they have a constant trend. The cause of the trend was investigated with a doubt that something else rather than operation of a nuclear power plant might have caused this trend. Due to high gross beta radioactivity concentration in winter, sometimes, radioactivity concentration five times higher than reported last five years average gross beta radioactivity concentration is detected. Looking at the contents investigated above, we can see nuclear power plants have correlation with surrounding gross beta radioactivity concentration. Precipitation has negative correlation, and the weight of air particles and concentration of component element have positive correlation. Our country is influenced by northwest wind in winter. China which is located northwest, has heavy air pollution and smog due to industrialization and there was a report saying it is affecting Korea. Therefore, not because of management of power plants but because of change in season, it can be misunderstood that operating power plants is causing the increased gross beta radioactivity concentration. Based on this investigation, more research to find various causes of gross beta radioactivity concentration in winter is necessary

  6. Effective particle magnetic moment of multi-core particles

    Energy Technology Data Exchange (ETDEWEB)

    Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden); Wetterskog, Erik; Svedlindh, Peter [Department of Engineering Sciences, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Lak, Aidin; Ludwig, Frank [Institute of Electrical Measurement and Fundamental Electrical Engineering, TU Braunschweig, D‐38106 Braunschweig Germany (Germany); IJzendoorn, Leo J. van [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Westphal, Fritz; Grüttner, Cordula [Micromod Partikeltechnologie GmbH, D ‐18119 Rostock (Germany); Gehrke, Nicole [nanoPET Pharma GmbH, D ‐10115 Berlin Germany (Germany); Gustafsson, Stefan; Olsson, Eva [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Johansson, Christer, E-mail: christer.johansson@acreo.se [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden)

    2015-04-15

    In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.

  7. Effective particle magnetic moment of multi-core particles

    International Nuclear Information System (INIS)

    Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian; Wetterskog, Erik; Svedlindh, Peter; Lak, Aidin; Ludwig, Frank; IJzendoorn, Leo J. van; Westphal, Fritz; Grüttner, Cordula; Gehrke, Nicole; Gustafsson, Stefan; Olsson, Eva; Johansson, Christer

    2015-01-01

    In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm

  8. Helium burning: a further measurement of the beta-delayed alpha-particle emission of 16 Na

    International Nuclear Information System (INIS)

    Gai, Moshe

    1997-01-01

    The 12 C (α,γ) 16 O is a key (but still unknown) reaction in helium burning. Several attempts to constrain the p-wave S-factor at Helium burning temperatures (200 M K) using the beta-delayed alpha-particle emission of 16 N have been made. However, some discrepancy exists between the spectra measured at Settle and that of TRIUMF. We have improved our previous study of the beta-delayed alpha-particle emission of 16 N by improving our statistical sample (by more than a factor of 5), improving the energy resolution of the experiment (by 20%), and in understanding our line shape, deduced from measured quantities. Our newly measured spectrum of the beta-delayed alpha-particle emission of 16 N is consistent with the Seattle ('95) data, as well as an earlier experiment performed at Mains ('71) and is not consistent with the TRIUMF ('94) data. (author)

  9. The effect of tachykinin neuropeptides on amyloid {beta} aggregation

    Energy Technology Data Exchange (ETDEWEB)

    Flashner, Efrat [The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904 (Israel); Raviv, Uri, E-mail: raviv@chem.ch.huji.ac.il [The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904 (Israel); Friedler, Assaf, E-mail: assaf@chem.ch.huji.ac.il [The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 91904 (Israel)

    2011-04-01

    Research highlights: {yields} Mechanistic explanation of how tachykinin neuropeptides reduce A{beta}-induced neurotoxicity. {yields} Biophysical studies suggest that tachykinins do not modulate the distribution of A{beta} oligomeric states, but rather may incorporate into the fibrils. {yields} A possible strategy to inhibit toxicity of amyloid fibrils. -- Abstract: A hallmark of Alzheimer's disease is production of amyloid {beta} peptides resulting from aberrant cleavage of the amyloid precursor protein. Amyloid {beta} assembles into fibrils under physiological conditions, through formation of neurotoxic intermediate oligomers. Tachykinin peptides are known to affect amyloid {beta} neurotoxicity in cells. To understand the mechanism of this effect, we studied how tachykinins affect A{beta}(1-40) aggregation in vitro. Fibrils grown in the presence of tachykinins exhibited reduced thioflavin T (ThT) fluorescence, while their morphology, observed in transmission electron microscopy (TEM), did not alter. Cross linking studies revealed that the distribution of low molecular weight species was not affected by tachykinins. Our results suggest that there may be a specific interaction between tachykinins and A{beta}(1-40) that allows them to co-assemble. This effect may explain the reduction of A{beta}(1-40) neurotoxicity in cells treated with tachykinins.

  10. Nanoscale size dependence in the conjugation of amyloid beta and ovalbumin proteins on the surface of gold colloidal particles

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, K; Briglio, N M; Hartati, D Sri; Tsang, S M W; MacCormac, J E; Welchons, D R [Department of Chemistry, State University of New York College at Geneseo, One College Circle, Geneseo, NY 14454 (United States)], E-mail: yokoyama@geneseo.edu

    2008-09-17

    Absorption spectroscopy was utilized to investigate the conjugation of amyloid {beta} protein solution (A{beta}{sub 1-40}) and chicken egg albumin (ovalbumin) with various sizes of gold colloidal nanoparticles for various pHs, ranging from pH 2 to pH 10. The pH value that indicates the colour change, pH{sub o}, exhibited colloidal size dependence for both A{beta}{sub 1-40} and ovalbumin coated particles. In particular, A{beta}{sub 1-40} coated gold colloidal particles exhibited non-continuous size dependence peaking at 40 and 80 nm, implying that their corresponding cage-like structures provide efficient net charge cancellation at these core sizes. Remarkably, only the pH{sub o} value for ovalbumin coated 80 nm gold colloid was pH>7, and a specific cage-like structure is speculated to have a positive net charge facing outward when ovalbumin self-assembles over this particular gold colloid. The previously reported reversible colour change between pH 4 and 10 took place only with A{beta}{sub 1-40} coated 20 nm gold colloids; this was also explored with ovalbumin coated gold colloids. Interestingly, gold colloidal nanoparticles showed a quasi-reversible colour change when they were coated with ovalbumin for all test sizes. The ovalbumin coated gold colloid was found to maintain reversible properties longer than A{beta}{sub 1-40} coated gold colloid.

  11. Biological effects of heavy particles

    International Nuclear Information System (INIS)

    Sabatier, L.; Martins, B.; Dutrillaux, B.

    1991-01-01

    The usual definitions of biological dose and biological dosimetry do not fit in case of particles with high linear energy transfer (LET). The dose corresponds to an average value which is not representative of the highly localized energy transfer due to heavy ions. Fortunately, up to now, a biological dosimetry following an exposure to high LET particles is necessary only for cosmonauts. In radiotherapy applications, one exactly knows the nature and energy of incident particle beams. The quality requirements for a good biodosimeter include reliable relation between dose and effect, weak sensitivity to individual variations, reliability and stability of acquired informations against the time delay between exposure and measurements. Nothing is better than the human lymphocyte to be used for measurements that fulfil these requirements. In the case of a manned spaceship, the irradiation dose corresponds to a wide range of radiation (protons, neutrons, heavy ions), and making a dosimetry as well as defining it are of current concern. As yet, there exist two possible definitions, which reduce the dose either to a proton or to a neutron equivalent one. However, such an approximation is not a faithful representation of the irradiation effects and in particular, the long-term effects may be quite different. In the future, it is reasonable to expect an evolution towards technics that enable identifying irradiated cells and quantifying precisely their radiation damage in order to reconstruct the spectrum of particles received by a given cosmonaut in a given time. Let us emphasize that the radiation hazards due to a short stay in space are quite minor, but in the case of a travel to Mars, they cannot be neglected [fr

  12. Numerical prediction effects of particle-particle collisions on gas-particle flows in swirl chamber

    International Nuclear Information System (INIS)

    Liu Yang; Liu Xue; Li Guohui; Jiang Lixiang

    2011-01-01

    In this paper, a unified-second-order-moment two-phase turbulent model incorporating into the kinetic theory of granular flows for considering particle-particle collision (USM-θ) is proposed to study the turbulent gas-particle flows in swirl chamber. Anisotropy of gas-solid two-phase stress and the interaction between two-phase stresses are fully considered by constructing a two-phase Reynolds stress model and a transport equation of two-phase stress correlation. Sommerfeld et al. (1991) experimental data is used to quantitatively validate USM-θ and USM model for analysis the effects of particle-particle collision. Numerical predicted results show that time-averaged velocity and fluctuation velocity of gas and particle using particle temperature model are better than those of without particle temperature model. Maximum particle concentration and temperature located at thin shear layer adjacent to wall surface due to particle inertia. Small-scale particle fluctuation due to particle-particle collision is smaller than large-scale gas-particle turbulence fluctuation. Particle-particle collision leads to the redistribution dissipation of Reynolds stress and particle turbulence kinetic energy.

  13. Particle image velocimetry in viscoelastic fluids and particle interaction effects

    Science.gov (United States)

    Mirsepassi, Alireza; Rankin, Derek Dunn

    2014-01-01

    Two main assumptions in laser doppler velocimetry and particle image velocimetry (PIV) are that tracer particles are following the flow faithfully and that they are not interacting hydrodynamically or affecting the flow field. It has been shown, however, that particles in polymeric fluids even in low volumetric concentrations ( ϕ PIV measurements. We chose a highly viscoelastic and shear thinning fluid and confirmed that particle string formation does occur rapidly in a simple shear flow of this fluid. Then, we measured via PIV, the fully developed velocity profile in the mid-plane of a square channel over a wide range of particle loadings 0.005-0.2 % v/v. The measurements confirm that despite the chaining process, there is no discernible effect of particle interaction on PIV velocity measurements.

  14. Cellular uptake of beta-carotene from protein stabilized solid lipid nano-particles prepared by homogenization-evaporation method

    Science.gov (United States)

    Using a homogenization-evaporation method, beta-carotene (BC) loaded nano-particles were prepared with different ratios of food-grade sodium caseinate (SC), whey protein isolate (WPI), or soy protein isolate (SPI) to BC and evaluated for their physiochemical stability, in vitro cytotoxicity, and cel...

  15. Effects of selective beta 1- and beta 2-adrenoreceptor agonists and antagonists on intraocular pressure in the cat.

    Science.gov (United States)

    Colasanti, B K; Trotter, R R

    1981-01-01

    Ocular tension of cats was measured after topical administration of the selective beta 1-adrenergic agonist CGP 7760B, the selective beta 1-adrenergic antagonist atenolol, the selective beta 2-adrenergic agonist salbutamol, the selective beta 2-adrenergic antagonist H 35/25, and the mixed beta 1- and beta 2-adrenergic antagonist timolol. Although atenolol did not alter intraocular pressure, CGP 7760B produced a modest decrease amounting to 3 to 4 mm Hg. Salbutamol, H 35/25, and timolol each produced a dose-dependent lowering of ocular tension, with maximal reductions amounting to 7, 5, and 5 mm Hg, respectively. Sympathetically denervated cat eyes showed supersensitivity to the pressure-lowering effect of salbutamol. In contrast, sympathectomy markedly reduced the effects of H 35/25 and timolol on ocular tension. Eyes rendered subsensitive to the pressure-lowering effects of cholinomimetics by chronic echothiophate treatment likewise showed diminished responsiveness to H 35/25 and timolol. Pretreatment with timolol (3 hr) completely abolished the pressure-lowering effect of salbutamol, and pretreatment with atenolol likewise completely antagonized the effect of CGP 7760B. These results suggest that beta-adrenergic receptors in the anterior segment of the cat eye are predominantly beta 2. Although beta-adrenergic antagonists apparently exert their effects on ocular tension by action at beta-adrenergic receptors, a cholinergic mechanism may be involved as well.

  16. Effects of the delta-hole channel in the double beta decay

    International Nuclear Information System (INIS)

    Hirsch, Jorge; Bauer, Eduardo; Krmpotic, Francisco

    1989-01-01

    Recently the half lives of the double beta decay have been calculated in such a way that they coincide for the first time with the experimental values. This has been done using the quasiparticle RPA formalism (QRPA) and the dependence of the transition amplitude of the particle-particle channel of the residual interaction. A more realistic estimation should include the effects of the delta-hole excitations (Δ-h) that are responsible for a significant reduction of the Gamow-Teller transitions intensity and that appear as virtual intermediate states in the calculation of the double beta decay amplitude. In this paper, the effect of the Δ-h channel is studied within the QRPA formalism and shown that the explicit inclusion of the Δ-h states for this particular process is equivalent to the renormalization of the axial coupling constant. (Author) [es

  17. Exchange effects in double beta decay

    International Nuclear Information System (INIS)

    Stephenson, G.J. Jr.; Goldman, T.; Maltman, K.R.; Schmidt, K.E.

    1988-01-01

    The motivation underlying the resurgence of interest in double beta decay is the hope that the observation of or limits on the 0-neutrino mode will provide information about the nature of the neutrino. This clearly requires confidence in the nuclear matrix elements involved in the transition. The shell model calculations do not agree well with the geochemical values for 130 Te, which has lead to a spate of papers offering specific fixes for the problem. In this contribution we shall not comment on any of the specific nuclear calculations, rather we make some remarks which should be relevant to any model calculation

  18. Response-surface models for deterministic effects of localized irradiation of the skin by discrete {beta}/{gamma} -emitting sources

    Energy Technology Data Exchange (ETDEWEB)

    Scott, B.R.

    1995-12-01

    Individuals who work at nuclear reactor facilities can be at risk for deterministic effects in the skin from exposure to discrete {Beta}- and {gamma}-emitting ({Beta}{gamma}E) sources (e.g., {Beta}{gamma}E hot particles) on the skin or clothing. Deterministic effects are non-cancer effects that have a threshold and increase in severity as dose increases (e.g., ulcer in skin). Hot {Beta}{gamma}E particles are {sup 60}Co- or nuclear fuel-derived particles with diameters > 10 {mu}m and < 3 mm and contain at least 3.7 kBq (0.1 {mu}Ci) of radioactivity. For such {Beta}{gamma}E sources on the skin, it is the beta component of the dose that is most important. To develop exposure limitation systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for systems that adequately control exposure of workers to discrete {Beta}{gamma}E sources, models are needed for evaluating the risk of deterministic effects of localized {Beta} irradiation of the skin. The purpose of this study was to develop dose-rate and irradiated-area dependent, response-surface models for evaluating risks of significant deterministic effects of localized irradiation of the skin by discrete {Beta}{gamma}E sources and to use modeling results to recommend approaches to limiting occupational exposure to such sources. The significance of the research results as follows: (1) response-surface models are now available for evaluating the risk of specific deterministic effects of localized irradiation of the skin; (2) modeling results have been used to recommend approaches to limiting occupational exposure of workers to {Beta} radiation from {Beta}{gamma}E sources on the skin or on clothing; and (3) the generic irradiated-volume, weighting-factor approach to limiting exposure can be applied to other organs including the eye, the ear, and organs of the respiratory or gastrointestinal tract and can be used for both deterministic and stochastic effects.

  19. Particle shape effects on subvisible particle sizing measurements.

    Science.gov (United States)

    Cavicchi, Richard E; Carrier, Michael J; Cohen, Joshua B; Boger, Shir; Montgomery, Christopher B; Hu, Zhishang; Ripple, Dean C

    2015-03-01

    Particle analysis tools for the subvisible (shape in comparison studies, we have used the methods of photolithography to create rods and disks. Although the rods are highly monodisperse, the instruments produce broadened peaks and report mean size parameters that are different for different instruments. We have fabricated a microfluidic device that simultaneously performs ESZ and FI measurements on each particle to elucidate the causes of discrepancies and broadening. Alignment of the rods with flow causes an oversizing by FI and undersizing by ESZ. FI also oversizes rods because of the incorrect edge definition that results from diffraction and imperfect focus. We present an improved correction algorithm for this effect that reduces discrepancies for rod-shaped particles. Tumbling of particles is observed in the microfluidic ESZ/FI and results in particle oversizing and breadth of size distribution for the monodisperse rods. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  20. Agonist-induced desensitization of beta-adrenoceptor function in humans. Subtype-selective reduction in beta 1- or beta 2-adrenoceptor-mediated physiological effects by xamoterol or procaterol

    NARCIS (Netherlands)

    Brodde, O. E.; Daul, A.; Michel-Reher, M.; Boomsma, F.; Man in 't Veld, A. J.; Schlieper, P.; Michel, M. C.

    1990-01-01

    We investigated the effects of beta 2- (procaterol 2 x 50 micrograms/day for 9 days) and beta 1- (xamoterol 2 x 200 mg/day for 14 days) adrenoceptor agonists on lymphocyte beta 2-adrenoceptor density and beta 1- and beta 2-adrenoceptor in vivo function (assessed as isoprenaline-infusion-evoked

  1. The effects of beta-carotene and vitamin E on erythrocytes lipid peroxidation in beta-thalassemia patients

    Directory of Open Access Journals (Sweden)

    Soleiman Mahjoub

    2007-12-01

    Full Text Available BACKGROUND: Thalassemia is the most common hereditary disease in the world. Thalassemic erythrocytes are exposed to higher oxidative stress and lipid peroxidation. The aim of this study was to investigate the effects of beta-carotene and vitamin E on erythrocytes lipid peroxidation in beta-thalassemia patients.
    METHODS: A prospective double-blind, placebo-controlled study of the effect of beta-carotene and vitamin E on lipid peroxidation in erythrocytes membranes was performed on 120 beta-thalassemia major patients in four groups. The patients were supplemented for 4 weeks as follows: group 1 with beta-carotene (13 mg/day, group 2 with vitamin E (550 mg/day, group 3 with beta-carotene plus vitamin E and group 4 with placebo. We prepared all capsules for 4 roups in the same shape and color. Measurements of serum beta-carotene and vitamin E were performed by high performance
    liquid chromatography. After preparation of ghost cells from blood specimens, malondialdehyde (MDA was determined as index of lipid peroxidation in erythrocytes membranes before and after treatment. RESULTS: The levels of serum beta-carotene and vitamin E were significantly lower and MDA concentrations in erythrocytes membranes were significantly higher in beta-thalassemia patients compared to controls (P<0.001. In groups that treated with vitamin supplements for 4-weeks, lipid peroxidation rates were significantly reduced after treatment (P<0.001, but in placebo group there was not significant difference (P>0.05.
    CONCLUSIONS: Our findings provide evidence that an oral treatment with beta-carotene and vitamin E can significantly reduce lipid peroxidation of erythrocytes membranes and could be useful in management of beta-thalassemia major patients. KEYWORDS: Beta-thalassemia major, beta-carotene, vitamin E, malondialdehyde, lipid peroxidation.

  2. Thermoluminescent response of CaSO{sub 4}: Dy + PTFE to beta particles; Respuesta termoluminiscente de CaSO{sub 4}: Dy + PTFE a particulas beta

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre C, A.; Azorin N, J. [Colegio de Bachilleres No. 13, Xochimilco-Tepepan, 16000 Mexico D.F. (Mexico)

    2000-07-01

    In this work the results of studying the thermoluminescent properties of CaSO{sub 4}: Dy + PTFE are presented when it is irradiated with beta particles. The conclusion was the obtention of the Tl response curve in function of dose is that to desexcite the dosemeters at temperature 300 C during 30 minutes and after that were irradiated at different times in groups and to do the reading of dosemeter, it can be observed that a greater irradiation time major is the Tl response and this depends of the material has been used. (Author)

  3. Fractional energy absorption from beta-emitting particles in the rat lung

    International Nuclear Information System (INIS)

    Snipes, M.B.

    1977-01-01

    Forty-four male, Fischer-344 rats were exposed nose-only to an aerosol of 144 Ce in fused aluminosilicate particles to obtain a relatively insoluble lung burden of this material. Twenty-eight rats, ages 12 to 25 weeks with body weights of 183 to 337 grams were analyzed seven to nine days after exposure; lung burdens were 13 to 82 nCi. An additional group of 16 rats was exposed when 12 weeks old and maintained for six months prior to analysis; body weights and lung burdens at six months after exposure ranged from 276 to 368 grams and 16 to 46 nCi, respectively. Lungs were analyzed, inflated and deflated in a 4π beta spectrometer to determine fractional energy absorption for 144 Ce. Over the relatively narrow range of sizes, 0.88 to 1.66 grams, for lungs in this study the average fractional energy absorption and its standard deviation was 0.23 +- 0.078 for the inflated lung and 0.40 +- 0.087 for the deflated lung

  4. Health Effects of Ozone and Particle Pollution

    Science.gov (United States)

    ... this page: Health Effects of Ozone and Particle Pollution Two types of air pollution dominate in the ... So what are ozone and particle pollution? Ozone Pollution It may be hard to imagine that pollution ...

  5. Particle effects on fish gills

    DEFF Research Database (Denmark)

    Lu, Cao; Kania, Per W.; Buchmann, Kurt

    2018-01-01

    Particles composed of inorganic, organic and/or biological materials occur in both natural water bodies and aquaculture facilities. They are expected to affect fish health through a direct chemical, mechanical and biological interaction with gills during ventilation but the nature of the reactions...... and the relative importance of mechanical versus chemical and biological stimulation are unknown. The present work presents an immune gene expression method for evaluation of gill disturbance and sets a baseline for the mechanical influence on fish gills of chemically inert spherical particles. The method may...... be applied to investigate particle impact at different combinations of temperature, fish size, water quality and particle composition. Spherical polystyrene particles (diameters 0.2 μm, 1 μm, 20 μm, 40 μm and 90 μm) were adopted as the particle model and the rainbow trout (Oncorhynchus mykiss) fingerlings...

  6. Microstructure and rheology of particle stabilized emulsions: Effects of particle shape and inter-particle interactions.

    Science.gov (United States)

    Katepalli, Hari; John, Vijay T; Tripathi, Anubhav; Bose, Arijit

    2017-01-01

    Using fumed and spherical silica particles of similar hydrodynamic size, we investigated the effects of particle shape and inter-particle interactions on the formation, stability and rheology of bromohexadecane-in-water Pickering emulsions. The interparticle interactions were varied from repulsive to attractive by modifying the salt concentration in the aqueous phase. Optical microscope images revealed smaller droplet sizes for the fumed silica stabilized emulsions. All the emulsions remained stable for several weeks. Cryo-SEM images of the emulsion droplets showed a hexagonally packed single layer of particles at oil-water interfaces in emulsions stabilized with silica spheres, irrespective of the nature of the inter-particle interactions. Thus, entropic, excluded volume interactions dominate the fate of spherical particles at oil-water interfaces. On the other hand, closely packed layers of particles were observed at oil-water interfaces for the fumed silica stabilized emulsions for both attractive and repulsive interparticle interactions. At the high salt concentrations, attractive inter-particles interactions led to aggregation of fumed silica particles, and multiple layers of these particles were then observed on the droplet surfaces. A network of fumed silica particles was also observed between the emulsion droplets, suggesting that enthalpic interactions are responsible for the determining particle configurations at oil-water interfaces as well as in the aqueous phase. Steady shear viscosity measurements over a range of shear stresses, as well as oscillatory shear measurements at 1Hz confirm the presence of a network in fumed silica suspensions and emulsions, and the lack of such a network when spherical particles are used. The fractal structure of fumed silica leads to several contact points and particle interlocking in the water as well as on the bromohexadecane-water interfaces, with corresponding effects on the structure and rheology of the emulsions

  7. Analysis of Deep Level Defects in GaN p-i-n Diodes after Beta Particle Irradiation

    Directory of Open Access Journals (Sweden)

    Sofiane Belahsene

    2015-12-01

    Full Text Available The effect of beta particle irradiation (electron energy 0.54 MeV on the electrical characteristics of GaN p-i-n diodes is investigated by current-voltage (I-V, capacitance-voltage (C-V and deep-level transient spectroscopy (DLTS measurements. The experimental studies show that, for the as-grown samples, three electron traps are found with activation energies ranging from 0.06 to 0.81 eV and concentrations ranging from 1.2 × 1014 to 3.6 × 1015 cm−3, together with one hole trap with energy depth of 0.83 eV and concentration of 8 × 1014 cm−3. It has been found that the irradiation has no effect on these intrinsic defects. The irradiation affected only a shallow donor level close to Ec [0.06 eV-0.18 eV] on the p-side of the p-i-n junction.

  8. Glucose regulates rat beta cell number through age-dependent effects on beta cell survival and proliferation.

    Directory of Open Access Journals (Sweden)

    Zerihun Assefa

    Full Text Available BACKGROUND: Glucose effects on beta cell survival and DNA-synthesis suggest a role as regulator of beta cell mass but data on beta cell numbers are lacking. We examined outcome of these influences on the number of beta cells isolated at different growth stages in their population. METHODS: Beta cells from neonatal, young-adult and old rats were cultured serum-free for 15 days. Their number was counted by automated whole-well imaging distinguishing influences on cell survival and on proliferative activity. RESULTS: Elevated glucose (10-20 versus 5 mmol/l increased the number of living beta cells from 8-week rats to 30%, following a time- and concentration-dependent recruitment of quiescent cells into DNA-synthesis; a glucokinase-activator lowered the threshold but did not raise total numbers of glucose-recruitable cells. No glucose-induced increase occurred in beta cells from 40-week rats. Neonatal beta cells doubled in number at 5 mmol/l involving a larger activated fraction that did not increase at higher concentrations; however, their higher susceptibility to glucose toxicity at 20 mmol/l resulted in 20% lower living cell numbers than at start. None of the age groups exhibited a repetitively proliferating subpopulation. CONCLUSIONS: Chronically elevated glucose levels increased the number of beta cells from young-adult but not from old rats; they interfered with expansion of neonatal beta cells and reduced their number. These effects are attributed to age-dependent differences in basal and glucose-induced proliferative activity and in cellular susceptibility to glucose toxicity. They also reflect age-dependent variations in the functional heterogeneity of the rat beta cell population.

  9. Glucose Regulates Rat Beta Cell Number through Age-Dependent Effects on Beta Cell Survival and Proliferation

    Science.gov (United States)

    Steyaert, Christophe; Stangé, Geert; Martens, Geert A.; Ling, Zhidong; Hellemans, Karine; Pipeleers, Daniel

    2014-01-01

    Background Glucose effects on beta cell survival and DNA-synthesis suggest a role as regulator of beta cell mass but data on beta cell numbers are lacking. We examined outcome of these influences on the number of beta cells isolated at different growth stages in their population. Methods Beta cells from neonatal, young-adult and old rats were cultured serum-free for 15 days. Their number was counted by automated whole-well imaging distinguishing influences on cell survival and on proliferative activity. Results Elevated glucose (10–20 versus 5 mmol/l) increased the number of living beta cells from 8-week rats to 30%, following a time- and concentration-dependent recruitment of quiescent cells into DNA-synthesis; a glucokinase-activator lowered the threshold but did not raise total numbers of glucose-recruitable cells. No glucose-induced increase occurred in beta cells from 40-week rats. Neonatal beta cells doubled in number at 5 mmol/l involving a larger activated fraction that did not increase at higher concentrations; however, their higher susceptibility to glucose toxicity at 20 mmol/l resulted in 20% lower living cell numbers than at start. None of the age groups exhibited a repetitively proliferating subpopulation. Conclusions Chronically elevated glucose levels increased the number of beta cells from young-adult but not from old rats; they interfered with expansion of neonatal beta cells and reduced their number. These effects are attributed to age-dependent differences in basal and glucose-induced proliferative activity and in cellular susceptibility to glucose toxicity. They also reflect age-dependent variations in the functional heterogeneity of the rat beta cell population. PMID:24416358

  10. Effects of Beta-Glucan on Performance of Broiler Rabbits

    Directory of Open Access Journals (Sweden)

    Martin Fik

    2016-10-01

    Full Text Available An experiment was conducted in order to evaluate the effects of beta glucan on selected breeding properties of broiler rabbits. The goal was to compare the results in two groups of animals, which were administered different beta glucan doses, during a period of time between weaning (day 42 after the birth and day 84 after the birth. Control group K was administered per oral suspension of Sulfacox, preparation against coccidiosis. Experimental group E1 was served a per oral water suspension of beta glucan powder, in concentration 5 g/L for every 5 kg of body weight. Experimental group E2 was served a per oral water suspension of beta glucan powder, in concentration 10 g/L for every 5 kg of body weight. At day 84 after the birth, control group C average body weight was 2515.75g, compared to 2459.88g in group E1 and 2455.77g in group E2. Two mortalities were noted in control group C between day 49 and 63, compared to two mortalities in group E1 and one mortality in group E2 during the same period of time. In all cases, coccidiosis was the reason for mortalities. In all animals, no statistically significant differences in selected breeding properties were observed.

  11. Isotope Effects in the Bonds of beta-CrOOH and beta-CrOOD

    DEFF Research Database (Denmark)

    Nørlund Christensen, A.; Hansen, P.; Lehmann, M. S.

    1976-01-01

    Samples of orthorhombic chromium oxide hydroxide, beta -CrOOH, and the deuterated compound, beta -CrOOD, were prepared hydrothermally. The crystal structures were determined by powder profile refinement technique using neutron diffraction data. Unit cells are: beta -CrOOH: a equals 4. 862(2) A, b...... equals 4. 298(a) A, c equals 2. 995(1) A; beta -CrOOD: a equals 4. 873(5) A, b equals 4. 332(7) A, c equals 2. 963(2) A, with Z equals 2. The space group is P2//1nm or Pnnm....

  12. Effect of beta limits on reactor performance in EBT

    International Nuclear Information System (INIS)

    Uckan, N.A.; Spong, D.A.; Nelson, D.B.

    1981-01-01

    Because of uncertainties in extrapolating results of simplified models to a reactor plasma, the parameters that influence the beta limits cannot be determined accurately at the present time. Also, the reasonable changes within the models and/or assumptions are seen to affect the core beta limits by almost an order of magnitde. Hence, at the present, these limits cannot be used as a rigid (and reliable) requirement for ELMO Bumpy Torus (EBT) reactor engineering considerations. However, sensitivity studies can be carried out to determine the boundaries of the operating regime and to demonstrate the effects of various modes, assumptions, and models on reactor performance (Q value). First, the modes believed to limit the core β and ring plasma performance are discussed, and the simplifications and/or assumptions involved in deriving these limits are highlighted. Then, the implications of these limits for a reactor are given

  13. Influence of hydrophobic Teflon particles on the structure of amyloid beta-peptide

    NARCIS (Netherlands)

    Giacomelli, C.E.; Norde, W.

    2003-01-01

    The amyloid beta-protein (Abeta) constitutes the major peptide component of the amyloid plaque deposits of Alzheimer's disease in humans. The Abeta changes from a nonpathogenic to a pathogenic conformation resulting in self-aggregation and deposition of the peptide. It has been established that

  14. Particle penetration and radiation effects

    CERN Document Server

    Sigmund, Peter

    This book, which has evolved from the author’s lectures at the University of Copenhagen and the University of Southern Denmark, draws on his experience as an active researcher in the interaction of charged particles with matter over more than forty years. The emphasis is on the theoretical description of fundamental phenomena, and much attention has been given to classic topics such as: Rutherford scattering; the theory of particle stopping as developed by Bohr, Bethe, Bloch and Lindhard; the statistical description of energy loss as developed by Bohr, Bothe, Williams and Landau; and numerous more recent developments. An attempt has been made to provide at least one complete derivation of a theoretical description for all central aspects. The presentation is intended to respect the ideas of the original authors, but much effort has been invested in establishing a unified and appealing notation consistent with present-day standards. It is intended that this volume will satisfy a long-standing need for a text...

  15. Accounting for beta-particle energy loss to cortical bone via paired-image radiation transport (PIRT)

    International Nuclear Information System (INIS)

    Shah, Amish P.; Rajon, Didier A.; Patton, Phillip W.; Jokisch, Derek W.; Bolch, Wesley E.

    2005-01-01

    Current methods of skeletal dose assessment in both medical physics (radionuclide therapy) and health physics (dose reconstruction and risk assessment) rely heavily on a single set of bone and marrow cavity chord-length distributions in which particle energy deposition is tracked within an infinite extent of trabecular spongiosa, with no allowance for particle escape to cortical bone. In the present study, we introduce a paired-image radiation transport (PIRT) model which provides a more realistic three-dimensional (3D) geometry for particle transport in the skeletal site at both microscopic and macroscopic levels of its histology. Ex vivo CT scans were acquired of the pelvis, cranial cap, and individual ribs excised from a 66-year male cadaver (BMI of 22.7 kg m -2 ). For the three skeletal sites, regions of trabecular spongiosa and cortical bone were identified and segmented. Physical sections of interior spongiosa were taken and subjected to microCT imaging. Voxels within the resulting microCT images were then segmented and labeled as regions of bone trabeculae, endosteum, active marrow, and inactive marrow through application of image processing algorithms. The PIRT methodology was then implemented within the EGSNRC radiation transport code whereby electrons of various initial energies are simultaneously tracked within both the ex vivo CT macroimage and the CT microimage of the skeletal site. At initial electron energies greater than 50-200 keV, a divergence in absorbed fractions to active marrow are noted between PIRT model simulations and those estimated under existing techniques of infinite spongiosa transport. Calculations of radionuclide S values under both methodologies imply that current chord-based models may overestimate the absorbed dose to active bone marrow in these skeletal sites by 0% to 27% for low-energy beta emitters ( 33 P, 169 Er, and 177 Lu), by ∼4% to 49% for intermediate-energy beta emitters ( 153 Sm, 186 Re, and 89 Sr), and by ∼14% to

  16. Preservation of the positive lusitropic effect of beta-adrenoceptors stimulation in diabetic cardiomyopathy.

    Science.gov (United States)

    Amour, Julien; Loyer, Xavier; Michelet, Pierre; Birenbaum, Aurélie; Riou, Bruno; Heymes, Christophe

    2008-10-01

    In diabetic cardiomyopathy, diastolic dysfunction results in part from sarcoplasmic reticulum abnormalities affecting both phospholamban and sarcoplasmic reticulum Ca2+ uptake (SERCA2a). Consequently, the positive lusitropic effect of beta-adrenoceptors stimulation could be altered, and beta3-adrenoceptor over-expression may play a role, as previously demonstrated with an altered positive inotropic effect. In this study, we tested the hypothesis that the beta-adrenergic positive lusitropic effect is altered in diabetic cardiomyopathy, and that beta3-adrenoceptor over-expression is involved. beta-adrenergic responses were investigated in vivo (dobutamine-echocardiography) and in vitro (papillary muscle preparation) in healthy and diabetic rats killed 4 (4W) and 12 (12W) wk after IV streptozotocin injection. The effect of beta3-adrenoceptor pathway inhibition by S-cyanopindolol (selective beta3-adrenoceptor antagonist) or by NG-nitro-L-arginine-methyl-ester (nonselective nitric oxide synthase inhibitor) on the lusitropic response to isoproterenol (nonselective beta-adrenoceptors agonist) was studied in vitro. Western blots were performed to quantify the protein expressions of beta1- and beta3-adrenoceptors, phospholamban, and SERCA2a. Data are presented as mean percentages of baseline+/-sd. Despite the increased phospholamban/SERCA2a protein ratio and documented diastolic dysfunction, the positive lusitropic effect of beta-adrenoceptors stimulation was preserved in vivo (dobutamine) and in vitro (isoproterenol) in 4W and 12W diabetic, compared with healthy, rats. The beta3-adrenoceptor was up-regulated whereas beta1-adrenoceptor was down-regulated in 4W and 12W diabetic, compared with healthy, rats. Nevertheless, S-cyanopindolol or NG-nitro-L-arginine-methyl-ester had no lusitropic effect. The positive lusitropic effect of beta-adrenoceptor stimulation was preserved in diabetic cardiomyopathy. beta3-adrenoceptor over-expression does not seem to affect this process.

  17. Effects of alpha particles on zebrafish embryos

    International Nuclear Information System (INIS)

    Yum, E.H.W.; Choi, V.W.Y.; Yu, K.N.; Li, V.W.T.; Cheng, S.H.

    2008-01-01

    Full text: Ionizing radiation such as X-ray and alpha particles can damage cellular macromolecules, which can lead to DNA single- and double-strand breaks. In the present work, we studied the effects of alpha particles on dechorionated zebrafish embryos. Thin polyallyldiglycol carbonate (PADC) films with a thickness of 16 μm were prepared from commercially available PADC films (with thickness of 100 μm) by chemical etching and used as support substrates for holding zebrafish embryos for alpha-particle irradiation. These films recorded alpha-particle hit positions, quantified the number and energy of alpha particles actually incident on the embryo cells, and thus enabled the calculation of the dose absorbed by the embryo cells. Irradiation was made at 1.25 hours post fertilization (hpf) with various absorbed dose. TdT-mediated dUTP Nick-End Labeling (TUNEL) assay was performed on the embryos at different time stages after irradiation. Marked apoptosis was detected only in embryos at earlier time stages. The results showed that DNA double-strand break during zebrafish embryogenesis can be induced by alpha-particle irradiation, which suggests that zebrafish is a potential model for assessing the effects of alpha-particle radiation

  18. URODYNAMIC EFFECTS OF BETA-ADRENOBLOCKERS: NEBIVOLOL ADVANTAGES

    Directory of Open Access Journals (Sweden)

    M. P. Savenkov

    2008-01-01

    Full Text Available Aim. To compare urodynamic effects of beta-blockers with different selectivity (propranolol, metoprolol, nebivolol in patients with arterial hypertension (HT and concomitant benign prostatic hyperplasia (BPH.Material and methods. 32 patients (aged 67,5 y.o. in average with HT of 1-2 stages were involved in the study. All patients had BPH (prostate volume >40 sm3 , increase of residual urine volume with moderate or severe low urinary tract symptoms (IPSS 8-25 and reduction of maximum urine flow rate to 5-13 ml/s. The urodynamic effect of beta-blockers was estimated by changes of urination frequency and uroflowmetry indices after single taking and 14-day therapy.Results. Propranolol and metoprolol led to aggravation of urination disorders. Nebivolol resulted in soft urodilating and urostimulating effects. It led to urination improvement and reduced a risk of urodynamic disorders.Conclusion. Urodynamic effects of cardiovascular drugs should be considered by practitioners especially in treatment of elderly patients.

  19. Therapeutic effect of beta radiation on onychomycosis: An innovative treatment

    International Nuclear Information System (INIS)

    Afroz, S.; Islam, N.; Rashid, H.; Shahidullah, M.; Ali, S.; Islam, S.K.M.; Hossain, S.; Ali, N.

    2005-01-01

    Full text: Onychomycosis is the most frequent cause of nail disease and the most prevalent type of dermatophytosis in Bangladesh. The humid and warm climate of this tropical country is congenial for the growth of fungi. Therapeutic limitations of conventional antimycotic agents in respect of low cure rates, high relapse rate, inherent side effects, long duration of treatment and high cost in treating onychomycosis have provided clear incentives to explore alternative forms of treatment procedure. The objectives of the present thesis work were: (i) To use beta radiation as a curative therapy for Onychomycosis, optimisation of its dosages and to promote an innovative clinical development in the field of therapeutic application of nuclear medicine; (ii) To assess the efficacy of beta radiation either alone or in combination with conventional antifungal therapy; and (iii) To reduce the duration of drug exposure and cost of treatment for onychomycosis. This is a PhD research work under the University of Dhaka and was sponsored by the Ministry of Science and Information and Communication Technology, Government of the people's republic of Bangladesh. This study is an open, randomised and controlled trial to verify the efficacy of beta radiation in patients with onychomycosis. Using the appropriate statistical formula, sample size of the study population was determined and in each group 92 patients were assigned. With an assumption of patients drop out and for better statistical analysis, a total of 330 patients, who fulfilled the inclusion criterion having diagnosed to have onychomycosis clinically and mycological were randomly allocated to enter in therapeutic regimen. Study population was randomised in three groups. Group A (n =110) received griseofulvin orally 500 mg once daily for 12-16 weeks; Group B (n=110) received beta radiation, 500 rads bi-weekly for 3 weeks (total 2500 rads); and Group C (n=110) received combined beta radiation (total 2500 rads in 3 weeks) and

  20. Effects of drugs on beta-endorphin and cortisol in smokers

    International Nuclear Information System (INIS)

    Du Tongxin; Wang Zizheng; Wang Shukui

    2001-01-01

    The authors observed the effects of drugs on beta-endorphin and cortisol in smokers and their correlation. The levels of plasma beta-endorphin and cortisol of smokers before and after cigarette withdrawal were detected by radioimmunoassay (RIA). The Levels of plasma beta-endorphin and cortisol in smokers is significantly higher than in controls. After natural withdrawal, the levels of plasma cortisol increased significantly, while beta-endorphin decreased significantly. After drug treatment, the levels of beta-endorphin and cortisol balanced. The drugs may play the role of cigarette withdrawal by improving the secretion of endogenous opium and the axis of hypothalamus-pituitary adrenal

  1. Atualizações sobre beta-hidroxi-beta-metilbutirato: suplementação e efeitos sobre o catabolismo de proteínas New findings on beta-hydroxy-beta-methylbutyirate: supplementation and effects on the protein catabolism

    Directory of Open Access Journals (Sweden)

    Everson Araújo Nunes

    2008-04-01

    Full Text Available O beta-hidroxi-beta-metilbutirato, metabólito do aminoácido leucina, vem sendo utilizado como suplemento alimentar, em situações específicas, com o intuito de aumentar ou manter a massa isenta de gordura. Os relatos dos efeitos do beta-hidroxi-beta-metilbutirato em estudos recentes fizeram crescer as expectativas sobre sua utilização em casos patológicos. Também foram demonstrados melhores resultados, quando da sua ingestão, no treinamento de força em indivíduos iniciantes e em idosos. Em humanos o beta-hidroxi-beta-metilbutirato tem sido usado como agente anti-catabólico, e em modelos animais foi demonstrado ser eficaz em inibir a atividade de vias proteolíticas em células musculares de indivíduos caquéticos in vitro e in vivo. Os mecanismos participantes desses processos envolvem: a inibição da atividade do sistema ubiquitina proteossoma ATP-dependente, a inibição de vias de sinalização com participação da proteína quinase C-alfa e a diminuição da concentração citoplasmática do fator nuclear - kappa B livre, eventos relacionados ao decréscimo da proteólise em células musculares.The leucine metabolite beta-hydroxy-beta-methylbutyrate has been used as a nutritional supplement in specific situations to prevent losing or to increase lean mass. Recent studies showed interesting results of beta-hydroxy-beta-methylbutyrate supplementation in certain disease states. Better results have also been demonstrated when it is taken by starters or old individuals doing strength training. In humans, beta-hydroxy-beta-methylbutyrate has been used as an anticatabolic agent and in animal models it has been demonstrated to be effective in inhibiting the activity of the proteolytic pathways in muscle cells of extremely weak individuals in vivo and in vitro. The mechanisms that participate in this process involve: inhibition of the ATP-ubiquitin-proteasome pathway, inhibition of the signalization pathways involving protein kinase C

  2. Is the treatment effect of IFN-beta restored after the disappearance of neutralizing antibodies?

    DEFF Research Database (Denmark)

    Sorensen, P S; Koch-Henriksen, Nils; Flachs, Esben Meulengracht

    2008-01-01

    OBJECTIVE: To establish whether multiple sclerosis (MS) patients, who have lost the therapeutic effect of interferon-beta (IFN-beta) owing to neutralizing antibodies (NAbs) and subsequently revert from a NAb-positive to a NAb-negative state under continued IFN-beta-1b therapy, regain clinical...... effect after reversion. BACKGROUND: Several studies have shown that a significant proportion of patients treated with IFN-beta develop NAbs that hamper or abolish the therapeutic effect of IFN-beta. However, some patients, who become NAb-positive under treatment with IFN-beta-1b, may revert to a NAb......-positive and reverted to a NAb-negative state regained treatment effect with the relapse rate as before the NAb-positive period adjusting for the effect of time, and the relapse rate was the same as in the permanently NAb-negative patients in corresponding time periods. The relapse rate ratio comparing the NAb...

  3. Fabrication and characterization of new LiF: Eu3+ sintered phosphors exposed to beta particles

    International Nuclear Information System (INIS)

    Garcia H, A.R.; Cruz V, C.; Bernal, R.; Barboza F, M.; Kitis, G.; Castano, V.M.

    2006-01-01

    Pellet-shaped LiF:Eu 3+ phosphors were synthesized by sintering. To improve their thermoluminescence characteristics, different growth conditions were used. Thermal annealing at 750 C during 5 h under air atmosphere provided the samples with highest sensitivity. Characteristic glow curves exhibit an absolute maximum centered at 203 C, and another less intense peak between 250 and 300 C. The first peak has a position very suitable for dosimetry applications. Beta irradiated samples displayed a thermoluminescence response that increases as the radiation dose increased in the 0.16 - 42.0 Gy range. A fast fading of less than 20 % occurs in the first 10 s after irradiation, followed by a remarkable stability at room temperature. Computerized glow curve deconvolution of experimental data obtained applying the McKeever method to resolve the individual peaks revealed that the glow curves fits to nine individual peaks. Activation energies were computed by using the initial rise method. (Author)

  4. The relative effectiveness of inhaled alpha- and beta-emitting radionuclides in producing lung cancer

    International Nuclear Information System (INIS)

    Boecker, B.B.; Hahn, F.F.; Muggenburg, B.A.; Guilmetter, R.A.; Griffith, W.C.; McClellan, R.O.

    1988-01-01

    Proper assessment of a long-term human health risks associated with inhaled radionuclides requires knowledge of dose to critical cells and tissues and relationships between dose and effect for different biological end points. Results from epidemiological studies of exposed human populations provided important information for such assessments. However, because the types of exposures are limited, these results need to be supplemented with more detailed information on dosimetry and biological effects available through studies in laboratory animals and in vitro systems. To provide health risk information for inhaled fission product and actinide aerosols, life-span studies are being conducted using beagle dogs and other species at the Lovelace Inhalation Toxicology Research Institute (ITRI). Results of two life-span studies in dogs involving inhalation of the beta emitter 91 Y in fused aluminosilicate particles or the alpha emitter 239 PuO 2 are reported here

  5. Metabolic effects of beta2-agonists in relation to exercise performance

    DEFF Research Database (Denmark)

    Kalsen, Anders

    2015-01-01

    athletes. The present PhD thesis is based on four manuscripts in which the acute effects of beta2-agonists on exercise performance were investigated. The aims were 1) to investigate whether supratherapeutic inhalation of beta2-agonists enhances muscle strength, anaerobic performance and aerobic performance...... that supratherapeutic inhalation of beta2-agonists increases muscle strength and improves performance during maximal sprinting lasting up to ~ 60 s, whereas no effect was observed on exercise lasting more than ~ 180 s. The ergogenic effects of beta2-agonists on power output during maximal sprinting requires......Beta2-agonists are frequently used in the treatment of asthma and exercise-induced bronchoconstriction in elite athletes. However, aside from a bronchodilatory effect, beta2-agonists have also been shown to improve exercise performance, which makes these substances subjected to misuse by elite...

  6. Metabolic effects of beta2-agonists in relation to exercise performance

    DEFF Research Database (Denmark)

    Kalsen, Anders

    2015-01-01

    Beta2-agonists are frequently used in the treatment of asthma and exercise-induced bronchoconstriction in elite athletes. However, aside from a bronchodilatory effect, beta2-agonists have also been shown to improve exercise performance, which makes these substances subjected to misuse by elite...... athletes. The present PhD thesis is based on four manuscripts in which the acute effects of beta2-agonists on exercise performance were investigated. The aims were 1) to investigate whether supratherapeutic inhalation of beta2-agonists enhances muscle strength, anaerobic performance and aerobic performance...... that supratherapeutic inhalation of beta2-agonists increases muscle strength and improves performance during maximal sprinting lasting up to ~ 60 s, whereas no effect was observed on exercise lasting more than ~ 180 s. The ergogenic effects of beta2-agonists on power output during maximal sprinting requires...

  7. Correcting for particle size effects on plasma actuator particle image velocimetry measurements

    Science.gov (United States)

    Masati, A.; Sedwick, R. J.

    2018-01-01

    Particle image velocimetry (PIV) is often used to characterize plasma actuator flow, but particle charging effects are rarely taken into account. A parametric study was conducted to determine the effects of particle size on the velocity results of plasma actuator PIV experiments. Results showed that smaller particles more closely match air flow velocities than larger particles. The measurement uncertainty was quantified by deconvolving the particle image diameter from the correlation diameter. The true air velocity was calculated by linearly extrapolating to the zero-size particle diameter.

  8. Beta Emission and Bremsstrahlung

    Energy Technology Data Exchange (ETDEWEB)

    Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-13

    Bremsstrahlung is continuous radiation produced by beta particles decelerating in matter; different beta emitters have different endpoint energies; high-energy betas interacting with high-Z materials will more likely produce bremsstrahlung; depending on the data, sometimes all you can say is that a beta emitter is present.

  9. Dielectric Polarization and Particle Shape Effects

    Directory of Open Access Journals (Sweden)

    Ari Sihvola

    2007-01-01

    Full Text Available This article reviews polarizability properties of particles and clusters. Especially the effect of surface geometry is given attention. The important parameter of normalized dipolarizability is studied as function of the permittivity and the shape of the surface of the particle. For nonsymmetric particles, the quantity under interest is the average of the three polarizability dyadic eigenvalues. The normalized polarizability, although different for different shapes, has certain universal characteristics independent of the inclusion form. The canonical shapes (sphere, spheroids, ellipsoids, regular polyhedra, circular cylinder, semisphere, double sphere are studied as well as the correlation of surface parameters with salient polarizability properties. These geometrical and surface parameters are essential in the material modeling problems in the nanoscale.

  10. Synergistic Effect of Hyperglycemia and Suppression on Adult Mouse Islet Beta Cell Replication

    Directory of Open Access Journals (Sweden)

    Szu-Tah Chen

    2012-01-01

    Full Text Available The complementary role of hyperglycemia and suppression on islet beta cell regeneration was investigated in a syngeneic mouse model. gene silencing was performed by infecting islets of C57BL/6 with shRNA lentiviral particles. At 54 hours after viral infection, protein content in cultured targeting islets was 22% of that in freshly isolated islets. Six days after transplantation to diabetic mice, targeting islet graft had considerably more cells with Ki67-staining nuclei than nontargeting islets. The mice in the targeting-islet group had a significantly shorter duration of temporary hyperglycaemia than mice in the non-targeting-islet group. The long-term ex vivo beneficial effect of silencing on graft function was also indicated by the significantly higher cumulative cure rate for diabetes in mice receiving 200 targeting islets than that in mice receiving 200 non-targeting islets. Our data suggest that hyperglycemia and persistent suppression have a synergistic effect on islet beta cell replication in adult mice.

  11. Thermoluminescent characterization of thin films of aluminium oxide irradiated with beta particles

    International Nuclear Information System (INIS)

    Villagran, E.; Escobar A, L.; Camps, E.; Gonzalez, P.R.

    2002-01-01

    By means of the laser ablation technique has been settled thin films of aluminium oxide on kapton substrates. These films present thermoluminescent response (Tl) when being exposed to beta radiation of a Sr 90 - Y 90 source (E max = 2.28 MeV). The brilliance curves show two peaks, one of them in 112 C degrees and the other one in 180 C degrees. The peak of low temperature is faded in some hours, whereas the high temperature one is more stable, showing a fading in the 15% order after three days of the irradiation. The Tl kinetic parameters were determined using the computerized deconvolution of the brilliance curve (CGDC). The results show that the high temperature peak is composed by four peaks which obey a second order kinetics with their maximum located at 165.7, 188.1, 215.3, and 246.5 C degrees. The depth of the traps (E) has values in the interval between 1.4 and 2.0 eV. The study of the dose response relation, show that the material presents a linear behavior in a dose interval from 150 mGy to 50 Gy. The obtained thin films of aluminium oxide could be a useful tool due to their potential applications in clinical dosimetry, in the determination of distributions of doses produced by penetrating weakly radiation, as well as in interfaces dosimetry. (Author)

  12. Effect of Beta-Carotene on Oxidative Stress and Expression of Cardiac Connexin 43

    Energy Technology Data Exchange (ETDEWEB)

    Novo, Rosangela; Azevedo, Paula S.; Minicucci, Marcos F.; Zornoff, Leonardo A. M., E-mail: lzornoff@fmb.unesp.br; Paiva, Sergio A. R. [Faculdade de Medicina de Botucatu - Universidade Estadual Paulista ' Júlio de Mesquita Filho' , Botucatu, SP (Brazil)

    2013-09-15

    Intervention studies have shown an increased mortality in patients who received beta-carotene. However, the mechanisms involved in this phenomenon are still unknown. Evaluate the influence of beta-carotene on oxidative stress and the expression of connexin 43 in rat hearts. Wistar rats, weighing approximately 100 g, were allocated in two groups: Control Group (n = 30), that received the diet routinely used in our laboratory, and Beta-Carotene Group (n = 28), which received beta-carotene (in crystal form, added and mixed to the diet) at a dose of 500 mg of beta carotene/kg of diet. The animals received the treatment until they reached 200-250g, when they were sacrificed. Samples of blood, liver and heart were collected to perform Western blotting and immunohistochemistry for connexin 43; morphometric studies, dosages of beta carotene by high performance liquid chromatography as well as reduced glutathione, oxidized glutathione and lipids hydroperoxides were performed by biochemical analysis. Beta-carotene was detected only in the liver of Beta-Carotene Group animals (288 ± 94.7 μg/kg). Levels of reduced/ oxidized glutathione were higher in the liver and heart of Beta-Carotene Group animals (liver - Control Group: 42.60 ± 1.62; liver - Beta-Carotene Group: 57.40 ± 5.90; p = 0.04; heart: - Control Group: 117.40 ± 1.01; heart - Beta-Carotene Group: 121.81 ± 1.32 nmol/mg protein; p = 0.03). The content of total connexin 43 was larger in Beta-Carotene Group. Beta-carotene demonstrated a positive effect, characterized by the increase of intercellular communication and improvement of anti-oxidizing defense system. In this model, mechanism does not explain the increased mortality rate observed with the beta-carotene supplementation in clinical studies.

  13. Risk assessment of hot beta-particles from the Chernobyl fallout in Bulgaria

    International Nuclear Information System (INIS)

    Uzunov, I.

    1993-01-01

    Research on hot particles (HP) was carried out in the Laboratory of Dosimetry and Radiation Protection. Field measurements with a Geiger-counter led to early discovery of HP on the ground in May 1986. Laboratory measurements of HP activity followed and their nuclide composition was determined. The carcinogenic risk of HP is discussed on the basis of a computer model assuming the radiation as initiator and all other factors as stimulators for cell proliferation (promoters). It is found that in the case of low radiation dose the probability for cancer is almost directly proportional to the number of cell divisions while at high radiation dose the slope is nearly vertical and reaches saturation point at about 5 cell divisions. An estimation of the number of inhaled HP was made by investigation of air filters. It is concluded that, besides iodine, inhaled HP are the most hazardous factor of the Chernobyl fallout. For some critical groups of the population, engaged in dusty outdoor operations, the carcinogenic risk was estimates as high as 0.1 - 1%. An average activity of 50 Bq per retained particle is proposed. It is stressed that Bulgarian population had not been informed adequately and no protection measures against HP intake had been taken. 3 figs., 12 refs

  14. Dimers of beta 2-glycoprotein I mimic the in vitro effects of beta 2-glycoprotein I-anti-beta 2-glycoprotein I antibody complexes

    NARCIS (Netherlands)

    Lutters, B. C.; Meijers, J. C.; Derksen, R. H.; Arnout, J.; de Groot, P. G.

    2001-01-01

    Anti-beta(2)-glycoprotein I antibodies are thought to cause lupus anticoagulant activity by forming bivalent complexes with beta(2)-glycoprotein I (beta(2)GPI). To test this hypothesis, chimeric fusion proteins were constructed of the dimerization domain (apple 4) of factor XI and beta(2)GPI. Both a

  15. Requirements regarding dose rate and exposure time for killing of tumour cells in beta particle radionuclide therapy

    Science.gov (United States)

    Eriksson, Veronika; Stenerlöw, Bo; Lundqvist, Hans

    2006-01-01

    Purpose The purpose of this study was to identify combinations of dose rate and exposure time that have the potential to provide curative treatment with targeted radionuclide therapy applying low dose rate beta irradiation. Methods Five tumour cell lines, U-373MG and U-118MG gliomas, HT-29 colon carcinoma, A-431 cervical squamous carcinoma and SKBR-3 breast cancer, were used. An experimental model with 105 tumour cells in each sample was irradiated with low dose rate beta particles. The criterion for successful treatment was absence of recovery of cells during a follow-up period of 3 months. The initial dose rates were in the range 0.1–0.8 Gy/h, and the cells were continuously exposed for 1, 3 or 7 days. These combinations covered dose rates and doses achievable in targeted radionuclide therapy. Results Continuous irradiation with dose rates of 0.2–0.3 and 0.4–0.6 Gy/h for 7 and 3 days, respectively, could kill all cells in each tumour cell sample. These treatments gave total radiation doses of 30–40 Gy. However, when exposed for just 24 h with about 0.8 Gy/h, only the SKBR-3 cells were successfully treated; all the other cell types recovered. There were large cell type-dependent variations in the growth delay patterns for the cultures that recovered. The U-118MG cells were most resistant and the U-373MG and SKBR-3 cells most sensitive to the treatments. The HT-29 and A-431 cells were intermediate. Conclusion The results serve as a guideline for the combinations of dose rate and exposure time necessary to kill tumour cells when applying low dose rate beta irradiation. The shift from recovery to “cure” fell within a narrow range of dose rate and exposure time combinations. PMID:16718515

  16. Effects of HZE particles on astronauts

    International Nuclear Information System (INIS)

    Curtis, S.B.; Townsend, L.W.; Wilson, J.W.

    1991-01-01

    Outside the effective shielding provided by Earth's magnetic field, space travelers will experience penetrating high-energy galactic cosmic rays, which reach the orbit of earth isotropically and with fluxes that vary smoothly over an 11-yr interval that is related to the 11-yr cycle of solar activity. This radiation consists of protons (Z=1) up to uranium (Z=92). There is an abundance of even--over odd-Z nuclei, with several local peaks in abundance when plotted as a function of Z. A prominent peak occurs in the iron abundance (Z=26) and is presumably related to the richness of iron in the galactic cosmic ray sources. The iron component is particularly important in a biological assessment of risk. High-energy particles with Z>2 have been called (high Z and energy) (HZE) particles. These particles are a concern in the evaluation of radiation risk because (a) they are highly ionizing and cause considerable damage as they penetrate biological tissue, and (b) they undergo nuclear interactions within the spacecraft shielding and the bodies of the astronauts themselves to produce lighter, more penetrating and sometimes highly ionizing secondaries. Considerably more ground-based cellular and animal experimentation is in order with high-energy heavy-ion beams before definitive statements can be made on the risk of HZE particles to humans outside the geomagnetosphere

  17. Effects of HZE particles on astronauts

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, S.B. (Lawrence Berkeley Lab., CA (United States)); Townsend, L.W.; Wilson, J.W. (National Aeronautics and Space Administration, Langley, CA (United States))

    1991-01-01

    Outside the effective shielding provided by Earth's magnetic field, space travelers will experience penetrating high-energy galactic cosmic rays, which reach the orbit of earth isotropically and with fluxes that vary smoothly over an 11-yr interval that is related to the 11-yr cycle of solar activity. This radiation consists of protons (Z=1) up to uranium (Z=92). There is an abundance of even--over odd-Z nuclei, with several local peaks in abundance when plotted as a function of Z. A prominent peak occurs in the iron abundance (Z=26) and is presumably related to the richness of iron in the galactic cosmic ray sources. The iron component is particularly important in a biological assessment of risk. High-energy particles with Z>2 have been called (high Z and energy) (HZE) particles. These particles are a concern in the evaluation of radiation risk because (a) they are highly ionizing and cause considerable damage as they penetrate biological tissue, and (b) they undergo nuclear interactions within the spacecraft shielding and the bodies of the astronauts themselves to produce lighter, more penetrating and sometimes highly ionizing secondaries. Considerably more ground-based cellular and animal experimentation is in order with high-energy heavy-ion beams before definitive statements can be made on the risk of HZE particles to humans outside the geomagnetosphere.

  18. The effect of transforming growth factor beta1 (TGF-beta1) on the regenerate bone in distraction osteogenesis.

    Science.gov (United States)

    Ozkan, Korhan; Eralp, Levent; Kocaoglu, Mehmet; Ahishali, Bulent; Bilgic, Bilge; Mutlu, Zihni; Turker, Mehmet; Ozkan, Feyza Unlu; Sahin, Kemal; Guven, Melih

    2007-04-01

    Distraction osteogenesis is a well established clinical treatment for limb length discrepancy and skeletal deformities. Transforming growth factor beta 1 (TGF-beta1) is a multifunctional peptide which controls proliferation and expression of cells specific to bone like chondrocytes, osteoblasts, osteoclasts including mesenchymal precursor cells. To decrease the external fixation time with increasing the strength of regenerate (newly formed bone after distraction) we tested the effect of locally applied transforming growth factor beta 1 on distraction osteogenesis. A total of 28 mature female white New zealand rabbits weighing 3,5 kg-4,5 kg were studied. 10 animals were belonging to biomechanical testing group (5 for the study and 5 for the control subgroups), and the others were to histology group. In biomechanical group after tibial osteotomy TGF-beta1 was applied subperiosteally for 5 days just proximal to osteotomy site. Control group received only the solvent. Seven days after tibial osteotomy distraction was started at a rate of 0.25 mm/12 hours for 3 weeks with a unilateral fixator. Rabbits were sacrificed at the end of a consolidation period 8 week after tibial osteotomy. We assessed density of the elongation zone of rabbit tibial bones with the computed tomography. Then biomechanical parametres were assessed using the torsional testing using the material testing machine. In histology group rabbits were classified as control and study (rabbits that were given TGF-beta1). Rabbits were sacrificed at the end of first week, second week and fourth week also at the end of consolidation period 8 week after tibial osteotomy. Immunohistochemical and histologic parameters were examined. Biomechanical testing was applied as torsional testing. These values are used in determination of maximal loading, stiffness and energy absorbed during testing (brittleness). The histomorphometric examination looked for the differences between the study and control groups in terms of

  19. Effects of beta-adrenergic blockers on drug-induced tremors.

    Science.gov (United States)

    Iwata, S; Nomoto, M; Fukuda, T

    1993-03-01

    We studied the effect of various kinds of beta-adrenergic blockers on oxotremorine-, harmaline- and thyrotropin-releasing hormone (TRH)-induced tremors in mice. To investigate what property of beta-blockers plays the main role in suppressing tremor, we employed five beta-blockers (propranolol, atenolol, butoxamine, pindolol, and arotinolol). All drugs suppressed oxotremorine-induced tremors but none reduced harmaline-induced tremors. Even though TRH-induced tremors were decreased significantly only by propranolol and high doses of arotinolol, all drugs had a tendency to reduce the tremor. We concluded that neuropharmacological mechanisms underlying to harmaline-induced tremors were different from those of TRH- and oxotremorine-induced tremors and that features of beta-blockers (beta 1- or beta 2-selectivity, intrinsic sympathomimetic activity, and membrane stabilizing activity) did not primarily contribute to the suppression of tremors.

  20. The effect of hexapole and vertical fields on {alpha}-particle confinement in heliotron configurations

    Energy Technology Data Exchange (ETDEWEB)

    Isaev, M.Yu. [RRC ' Kurchatov Institute' , Nuclear Fusion Institute, Moscow (Russian Federation); Watanabe, K.Y.; Yokoyama, M.; Yamazaki, K. [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2003-03-01

    Collisionless mono-energetic {alpha}-particle confinement in three-dimensional magnetic fields obtained from the magnetic coils of the Large Helical Device (LHD) is calculated. It is found that the inward shift of magnetic axis due to the vertical field improves the {alpha}-particle confinement. In contrast to the vertical field, both large positive and negative hexapole fields do not improve the confinement. The study of the {beta} effect and Mercier criterion calculations for different hexapole fields are also presented. (author)

  1. Effect of Particle Size on Shear Stress of Magnetorheological Fluids

    Directory of Open Access Journals (Sweden)

    Chiranjit Sarkar

    2015-05-01

    Full Text Available Magnetorheological fluids (MRF, known for their variable shear stress contain magnetisable micrometer-sized particles (few micrometer to 200 micrometers in a nonmagnetic carrier liquid. To avoid settling of particles, smaller sized (3-10 micrometers particles are preferred, while larger sized particles can be used in MR brakes, MR clutches, etc. as mechanical stirring action in those mechanisms does not allow particles to settle down. Ideally larger sized particles provide higher shear stress compared to smaller sized particles. However there is need to explore the effect of particle sizes on the shear stress. In the current paper, a comparison of different particle sizes on MR effect has been presented. Particle size distributions of iron particles were measured using HORIBA Laser Scattering Particle Size Distribution Analyser. The particle size distribution, mean sizes and standard deviations have been presented. The nature of particle shapes has been observed using scanning electron microscopy. To explore the effect of particle sizes, nine MR fluids containing small, large and mixed sized carbonyl iron particles have been synthesized. Three concentrations (9%, 18% and 36% by volume for each size of particles have been used. The shear stresses of those MRF samples have been measured using ANTON PAAR MCR-102 Rheometer. With increase in volume fraction of iron particles, the MR fluids synthesized using “mixed sized particles” show better shear stress compared to the MR fluids containing “smaller sized spherical shaped particles” and “larger sized flaked shaped particles” at higher shear rate.

  2. Fabrication and characterization of new NaF: Eu3+ sintered phosphors exposed to beta particle irradiation

    International Nuclear Information System (INIS)

    Bernal, R.; Garcia H, A.R.; Cruz V, C.; Kitis, G.; Castano, V.M.

    2007-01-01

    Full text: NaF:Eu 3+ phosphors were synthesized by sintering after mixing NaF and EuCI 3 in an aqueous solution. The sintering conditions were thermal annealing at 750 C during 5 h under air atmosphere. When a 5 C/s heating rate was used, the characteristic glow curves of beta particle irradiated samples exhibit two TL maxima located at 128 C and 225 C, being the higher temperature peak the most intense. A peak located between 200 and 250 C is considered to have a position very suitable to assure good thermal stability of the stored TL, for which this phosphor is attractive for radiation dosimetry. The TL increased proportionally to dose increase in the range investigated (from 0.0083 to 42.5 Gy), with a linear behavior below 10 Gy followed by a sub linear one for higher doses. Under storage after irradiation, the peak at 225 C displayed a remarkable stability, and the TL fading revealed that the peak at 128 C is not a single peak. The sensitivity of this new phosphor relative to the TLD-100 dosimeter is ca. 1. (Author)

  3. Evaluation of thermoluminescent dosimeters (TLDs) of two different designs for beta particle and low energy photon dosimetry

    International Nuclear Information System (INIS)

    Nugent, K.J.; Ahmed, A.B.; Groer, P.G.

    1992-11-01

    The purpose of this research was to compare the response of the thermoluminescent dosimeters (TLDs) currently used at Martin Marietta Energy Systems with that of a newly designed TLD which is now under consideration. The new TLD consists of a thicker chip in element No. 3 and a thinner, more opaque mylar filter over this same element. The goals were to determine if the new (proposed) TLD would perform significantly different from the old (current) TLD when measuring dose equivalents from beta particles and low energy photons (x-rays) and to find out if changing from the old to the new design would require that modifications be made to the calibration factors currently used in the dose calculation algorithm. To accomplish these objectives, tests were performed using both types of dosimeters placed under identical conditions. Their responses were then compared and analyzed. It was concluded that the new TLDs would allow for the detection of lower levels of radiation and give more precise readouts at very low (i.e., background) levels in addition to the obvious advantages of the new design, such as, a thicker, more durable chip and a more opaque mylar. It was also determined that no adjustments to the calibration factors would be necessary in switching to the new design

  4. Effect of Addition of Cereal Based Beta-glucan on Technological and Functional Properties of Foods

    Directory of Open Access Journals (Sweden)

    Nihal Şimşekli

    2015-01-01

    Full Text Available Nowadays usage of dietary fibers in foods has been increasing duo to revealing of health benefits. Beta-glucans found especially in oats and barley, are polysaccharide and source of water-soluble dietary fiber. Positive effects of beta-glucans like healing coronary-heart disease, lowering blood cholesterol level, balancing blood sugar level and preventing obesity, made beta-glucans widespread functional food components for producing various foods. In addition to beneficial physiological effects of beta-glucans, they texturize, gelatinize, emulsify and stabilize the foods. They increase viscosity, replace fat and enhance rheological properties in cereal, meat and dairy products. They are also used to produce packing material depending on their mechanical properties and molecular weights. In this review, effects of addition of cereal based beta-glucans on technological and functional properties of various foods are revealed based on previous studies.

  5. EFFECTS OF EFFECTS OF PARTICLE SIZE DISTRIBUTION ...

    African Journals Online (AJOL)

    eobe

    Bioremediation has been proven to be the most effective method of cleaning up oil contaminated soils through the application of nutrients and microor the application of nutrients and microorganism. Hence, this ganism. Hence, this ganism. Hence, this research presents the research presents the research presents the ...

  6. Effect of glucose infusion on endurance performance after beta-adrenoceptor blocker administration

    NARCIS (Netherlands)

    van Baak, M.A.; Mooij, J.M.

    1994-01-01

    Effect of glucose infusion on endurance performance after beta-adrenoceptor blocker administration. Van Baak MA, Mooij JM. Department of Human Biology, University of Limburg, Maastricht, The Netherlands. To investigate the effect of glucose (Glc) infusion on endurance performance after

  7. Effect of beta-escin sodium on endothelial cells proliferation, migration and apoptosis.

    Science.gov (United States)

    Wang, Xu-Hua; Xu, Bo; Liu, Jing-Tao; Cui, Jing-Rong

    2008-01-01

    beta-Escin, the major active compound in extracts of the horse chestnut Aesculus hippocastanum seed, has shown clinically significant activity in chronic venous insufficiency (CVI). Our previous studies had shown that beta-escin sodium inhibited angiogenesis in chick chorioallantoic membrane (CAM) and in aortic disk assay. In this study, we explored the direct effect of beta-escin sodium on proliferation, migration and apoptosis in human umbilical vein endothelial cells (HUVECs) and ECV304 cells. Sulforhodamine B (SRB) assay showed that beta-escin sodium (10, 20, 40 microg/ml) inhibited endothelial cells (ECs) proliferation dose-dependently. beta-escin sodium also induced ECs apoptosis at 40 microg/ml. Cell migration was evaluated by an improved wound assay: barren spot assay. And the direct effect on cell motility excluding influence of cell proliferation was examined by High Content Screening (HCS, Cellomics) assay. The data indicated that beta-escin sodium suppressed ECs migration and cell motility. Western blot results suggested that beta-escin sodium acts on ECs possibly by increasing expression of thrombospondin-1 (TSP-1), and decreasing expression of PKC-alpha and activation of p44/42 mitogen-activated protein kinase (ERK) and p38 mitogen-activated protein kinase (p38 MAPK). Our findings give the evidence that beta-escin sodium might have potential anti-angiogenic activity via its direct effects on ECs.

  8. Effect of beta-alanine, with and without sodium bicarbonate, on 2000-m rowing performance.

    Science.gov (United States)

    Hobson, Ruth M; Harris, Roger C; Martin, Dan; Smith, Perry; Macklin, Ben; Gualano, Bruno; Sale, Craig

    2013-10-01

    To examine the effect of beta-alanine only and beta-alanine with sodium bicarbonate supplementation on 2,000-m rowing performance. Twenty well-trained rowers (age 23 ± 4 y; height 1.85 ± 0.08 m; body mass 82.5 ± 8.9 kg) were assigned to either a placebo or beta-alanine (6.4 g · d(-1) for 4 weeks) group. A 2,000-m rowing time trial (TT) was performed before supplementation (Baseline) and after 28 and 30 days of supplementation. The post supplementation trials involved supplementation with either maltodextrin or sodium bicarbonate in a double-blind, crossover design, creating four study conditions (placebo with maltodextrin; placebo with sodium bicarbonate; beta-alanine with maltodextrin; beta-alanine with sodium bicarbonate). Blood lactate, pH, bicarbonate, and base excess were measured pre-TT, immediately post-TT and at TT+5 min. Performance data were analyzed using magnitude based inferences. Beta-alanine supplementation was very likely to be beneficial to 2,000-m rowing performance (6.4 ± 8.1 s effect compared with placebo), with the effect of sodium bicarbonate having a likely benefit (3.2 ± 8.8 s). There was a small (1.1 ± 5.6 s) but possibly beneficial additional effect when combining chronic beta-alanine supplementation with acute sodium bicarbonate supplementation compared with chronic beta-alanine supplementation alone. Sodium bicarbonate ingestion led to increases in plasma pH, base excess, bicarbonate, and lactate concentrations. Both chronic beta-alanine and acute sodium bicarbonate supplementation alone had positive effects on 2,000-m rowing performance. The addition of acute sodium bicarbonate to chronic beta-alanine supplementation may further enhance rowing performance.

  9. Rheology behavior and optimal damping effect of granular particles in a non-obstructive particle damper

    Science.gov (United States)

    Zhang, Kai; Chen, Tianning; Wang, Xiaopeng; Fang, Jianglong

    2016-03-01

    To explore the optimal damping mechanism of non-obstructive particle dampers (NOPDs), research on the relationship between the damping performance of NOPDs and the motion mode of damping particles in NOPDs was carried out based on the rheological properties of vibrated granular particles. Firstly, the damping performance of NOPDs under different excitation intensity and gap clearance was investigated via cantilever system experiments, and an approximate evaluation of the effective mass and effective damping of NOPDs was performed by fitting the experimental data to an equivalent single-degree-of-freedom (SDOF) system with no damping particles. Then the phase diagrams which could show the motion mode of damping particles under different excitation intensity and gap clearance were obtained via a series of vibration table tests. Moreover, the dissipation characteristic of damping particles was explored by the discrete element method (DEM). The study results indicate that when NOPDs play the optimal damping effect the granular Leidenfrost effect whereby the entire particle bed in NOPDs is levitated above the vibrating base by a layer of highly energetic particles is observed. Finally, the damping characteristics of NOPDs was explained by collisions and frictions between particle-particle and particle-wall based on the rheology behavior of damping particles and a new dissipation mechanism was first proposed for the optimal damping performance of NOPDs.

  10. Cholesterol-lowering effect of beta-glucan from oat bran in mildly hypercholesterolemic subjects may decrease when beta-glucan is incorporated into bread and cookies

    NARCIS (Netherlands)

    Kerckhoffs, D.A.J.M.; Hornstra, G.; Mensink, R.P.

    2003-01-01

    Cholesterol-lowering effect of beta-glucan from oat bran in mildly hypercholesterolemic subjects may decrease when beta-glucan is incorporated into bread and cookies. Kerckhoffs DA, Hornstra G, Mensink RP. Department of Human Biology, Maastricht University, Maastricht, The Netherlands. BACKGROUND:

  11. Effect of beta-adrenergic receptor antagonists on nicotine-induced tail-tremor in rats.

    Science.gov (United States)

    Suemaru, K; Gomita, Y; Furuno, K; Araki, Y

    1993-09-01

    The effects of various beta-adrenergic receptor antagonists on nicotine-induced tail-tremor were investigated in rats. Atenolol (5 and 10 mg/kg, IP), arotinolol (5 and 10 mg/kg, IP), and carteolol (5 and 10 mg/kg, IP), hydrophilic beta-adrenergic receptor antagonists, did not affect the tail-tremor induced by nicotine given at a dose of 0.5 mg/kg SC. However, propranolol (5-20 mg/kg, IP) and pindolol (5-20 mg/kg, IP), nonselective and lipophilic beta-adrenergic receptor antagonists, did suppress the tail-tremor dose dependently. In contrast, metoprolol (5-20 mg/kg, IP), lipophilic and beta 1-selective adrenergic receptor antagonists, did not show such an effect. These results suggest that nicotine-induced tail-tremors may be mediated through central beta 2-adrenergic receptors as an appearance and developmental mechanism.

  12. Finite beta effects on turbulent transport in tokamak plasmas

    International Nuclear Information System (INIS)

    Hein, Tobias

    2011-01-01

    The research on the transport properties of magnetically confined plasmas plays an essential role towards the achievement of practical nuclear fusion energy. An economically viable fusion reactor is expected to operate at high plasma pressure. This implies that the detailed study of the impact of electromagnetic effects, whose strength increases with increasing pressure, is of critical importance. In the present work, the electromagnetic effects on the particle, momentum and heat transport channels have been investigated, with both analytical and numerical calculations. Transport processes due to a finite plasma pressure have been identified, their physical mechanisms have been explained, and their contributions have been quantified, showing that they can be significant under experimentally relevant conditions.

  13. Effects of particle production during inflation

    International Nuclear Information System (INIS)

    Romano, Antonio Enea; Sasaki, Misao

    2008-01-01

    The impact of particle production during inflation on the primordial curvature perturbation spectrum is investigated both analytically and numerically. We obtain an oscillatory behavior on small scales, while on large scales the spectrum is unaffected. The amplitude of the oscillations is proportional to the number of coupled fields, their mass, and the square of the coupling constant. The oscillations are due to a discontinuity in the second time derivative of the inflaton, arising from a temporary violation of the slow-roll conditions. A similar effect on the power spectrum should be produced also in other inflationary models where the slow-roll conditions are temporarily violated.

  14. Effects of heat treatment and pectin addition on beta-lactoglobulin allergenicity.

    Science.gov (United States)

    Peyron, Stéphane; Mouécoucou, Justine; Frémont, Sophie; Sanchez, Christian; Gontard, Nathalie

    2006-07-26

    The specific effects of heat treatment and/or addition of low/high-methylated pectin (LMP/HMP) on the allergenicity of beta-lactoglobulin (beta-Lg) and its hydrolysis products were investigated through a two-step in vitro digestion approach. beta-Lg was first hydrolyzed by pepsin and then by a trypsin/chymotrypsin (T/C) mixture done in a dialysis bag with a molecular weight cutoff of 1000. The protein digestion was followed by SDS-PAGE electrophoresis performed on each digestion product, and their in vitro allergenicity was analyzed by immunoblotting. Such procedure was applied on beta-Lg samples mixed with the two kinds of pectin before or after heating (80 degrees C, 25 min) to determine the respective impact of heat treatment and pectin addition. Heat denaturation improved significantly the susceptibility of beta-Lg against the pepsin and the T/C. This effect, which was coupled to a reduction in immunoreactivity of the digested beta-Lg, appeared to be distinctively modulated by LMP and HMP. Through nonspecific interaction with the beta-Lg, pectin could reduce the accessibility of cleavage sites and/or epitope sequences. This mechanism of action is discussed in relation to the intra- and intermolecular interactions between beta-Lg and pectin initiated under the experimental conditions.

  15. Effect of particle-particle interactions on the acoustic radiation force in an ultrasonic standing wave

    Energy Technology Data Exchange (ETDEWEB)

    Lipkens, Bart, E-mail: blipkens@wne.edu [Mechanical Engineering, Western New England University, Springfield, Massachusetts, 01119 (United States); Ilinskii, Yurii A., E-mail: ilinskii@gmail.com; Zabolotskaya, Evgenia A., E-mail: zheniazabolotskaya@gmail.com [Applied Research Laboratories, The University of Texas at Austin, Austin, Texas 78713–8029 (United States)

    2015-10-28

    Ultrasonic standing waves are widely used for separation applications. In MEMS applications, a half wavelength standing wave field is generated perpendicular to a laminar flow. The acoustic radiation force exerted on the particle drives the particle to the center of the MEMS channel, where concentrated particles are harvested. In macro-scale applications, the ultrasonic standing wave spans multiple wavelengths. Examples of such applications are oil/water emulsion splitting [1], and blood/lipid separation [2]. In macro-scale applications, particles are typically trapped in the standing wave, resulting in clumping or coalescence of particles/droplets. Subsequent gravitational settling results in separation of the secondary phase. An often used expression for the radiation force on a particle is that derived by Gorkov [3]. The assumptions are that the particle size is small relative to the wavelength, and therefore, only monopole and dipole scattering contributions are used to calculate the radiation force. This framework seems satisfactory for MEMS scale applications where each particle is treated separately by the standing wave, and concentrations are typically low. In macro-scale applications, particle concentration is high, and particle clumping or droplet coalescence results in particle sizes not necessarily small relative to the wavelength. Ilinskii et al. developed a framework for calculation of the acoustic radiation force valid for any size particle [4]. However, this model does not take into account particle to particle effects, which can become important as particle concentration increases. It is known that an acoustic radiation force on a particle or a droplet is determined by the local field. An acoustic radiation force expression is developed that includes the effect of particle to particle interaction. The case of two neighboring particles is considered. The approach is based on sound scattering by the particles. The acoustic field at the location of

  16. The effect of beta-adrenoceptor antagonists on the alpha-adrenoceptor blockade produced by phenoxybenzamine.

    Science.gov (United States)

    Sankaranarayanan, A; Sharma, P L

    1977-05-01

    The effect of beta-adrenoceptor antagonists on the irreversible alpha-adrenoceptor blockade produced by phenoxybenzamine was studied in dogs. The pressor effects of adrenaline were revived after the inhibition by the alpha-receptor block by (+/-) propranolol, (-) INPEA, (+/-) MJ 1999 and (+/-) butoxamine. The enantiomers (+) propranolol and (+) INPEA were ineffective in this regard. (+/-) Practolol also did not revive the pressor effect of the amines. The alpha-receptor mediated effect of the amines, in the nictitating membrana-receptor blockade. It is concluded that (1) blockade of the peripheral (beta-2) receptors is essential for the revival of the pressor effects, (2) local anesthetic effect of the beta-antagonists is not involved. Further work using a series of doses of agonists and antagonists of alpha-and beta-receptors is indicated to clarify the nature of this drug-interaction.

  17. In vitro effects of Beta-2 agonists on skeletal muscle differentiation, hypertrophy, and atrophy.

    Science.gov (United States)

    Wannenes, Francesca; Magni, Loretta; Bonini, Matteo; Dimauro, Ivan; Caporossi, Daniela; Moretti, Costanzo; Bonini, Sergio

    2012-06-01

    : Beta-2 agonists are widely used in the treatment of asthma and chronic obstructive pulmonary disease for their effect on airway smooth muscle relaxation. They also act on skeletal muscle, although their reported ergogenic effect is controversial. : To evaluate the in vitro effects of short-acting and long-acting beta-2 agonists on adrenergic receptor (ADR) expression, hypertrophy, and atrophy markers, in a skeletal muscle cell line. : The C2C12 cell line was used as a model of skeletal muscle differentiation. ADR messenger RNA expression was evaluated in proliferating myoblasts, committed cells, and differentiated myotubes, in basal conditions and after treatment with 10 M clenbuterol, salbutamol, salmeterol, and formoterol. Effect of beta-2 agonists on gene and protein expression of hypertrophy and atrophy markers was assessed in differentiated myotubes. : Our study shows that beta-2 ADR messenger RNA was expressed and progressively increased during cell differentiation. Beta-2 agonist treatment did not affect its expression. Skeletal muscle hypertrophy markers (fast and slow myosin, myogenin) were not modulated by any of the beta-2 agonists evaluated. However, clenbuterol induced a significant, dose-dependent downregulation of skeletal muscle atrophy genes (atrogin-1, MuRF-1, and cathepsin L). : The reported ergogenic effect of beta-2 agonists, if any, should be considered as drug-specific and not class-specific and that of clenbuterol is mediated by the inhibition of the atrophic pathway.

  18. Strategic Design of an Effective beta-Lactamase Inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Pattanaik, P.; Bethel, C; Hujer, A; Hujer, K; Distler, A; Taracila, M; Anderson, V; Fritsche, T; Jones, R; et. al.

    2009-01-01

    In an effort to devise strategies for overcoming bacterial beta-lactamases, we studied LN-1-255, a 6-alkylidene-2'-substituted penicillin sulfone inhibitor. By possessing a catecholic functionality that resembles a natural bacterial siderophore, LN-1-255 is unique among beta-lactamase inhibitors. LN-1-255 combined with piperacillin was more potent against Escherichia coli DH10B strains bearing bla(SHV) extended-spectrum and inhibitor-resistant beta-lactamases than an equivalent amount of tazobactam and piperacillin. In addition, LN-1-255 significantly enhanced the activity of ceftazidime and cefpirome against extended-spectrum cephalosporin and Sme-1 containing carbapenem-resistant clinical strains. LN-1-255 inhibited SHV-1 and SHV-2 beta-lactamases with nm affinity (K(I) = 110 +/- 10 and 100 +/- 10 nm, respectively). When LN-1-255 inactivated SHV beta-lactamases, a single intermediate was detected by mass spectrometry. The crystal structure of LN-1-255 in complex with SHV-1 was determined at 1.55A resolution. Interestingly, this novel inhibitor forms a bicyclic aromatic intermediate with its carbonyl oxygen pointing out of the oxyanion hole and forming hydrogen bonds with Lys-234 and Ser-130 in the active site. Electron density for the 'tail' of LN-1-255 is less ordered and modeled in two conformations. Both conformations have the LN-1-255 carboxyl group interacting with Arg-244, yet the remaining tails of the two conformations diverge. The observed presence of the bicyclic aromatic intermediate with its carbonyl oxygen positioned outside of the oxyanion hole provides a rationale for the stability of this inhibitory intermediate. The 2'-substituted penicillin sulfone, LN-1-255, is proving to be an important lead compound for novel beta-lactamase inhibitor design.

  19. Effects Of Amitryptilin Administration on Rat Sera and Brain Beta-endorphins

    Directory of Open Access Journals (Sweden)

    Radivoj Jadrić

    2006-11-01

    Full Text Available The aim of our study was to establish the influence of antidepressive drugs on serum and brain beta-endorphins in experimental animals. Experiment was performed on albino Wistar rats. Antidepressant amitryptiline was used, and for quantification of sera and brain beta-endorphins RIA technique. Our results showed difference between sera and brain beta-endorphins concentration in amitryptiline pretreated animals, vs. those in serum and brain of control group treated with 0.95% NaCl. This study shows that use of psychoactive drugs have influence on sera and brain beta-endorphins concentration. Beta-endorphins could be of great importance, used as markers for evaluation of antidepressant drug effects.

  20. Effects of ultrasound on Transforming Growth Factor-beta genes in bone cells

    Directory of Open Access Journals (Sweden)

    J Harle

    2005-12-01

    Full Text Available Therapeutic ultrasound (US is a widely used form of biophysical stimulation that is increasingly applied to promote fracture healing. Transforming growth factor-beta (TGF-beta, which is encoded by three related but different genes, is known to play a major part in bone growth and repair. However, the effects of US on the expression of the TGF-beta genes and the physical acoustic mechanisms involved in initiating changes in gene expression in vitro, are not yet known. The present study demonstrates that US had a differential effect on these TGF-beta isoforms in a human osteoblast cell line, with the highest dose eliciting the most pronounced up-regulation of both TGF-beta1 and TGF-beta3 at 1 hour after treatment and thereafter declining. In contrast, US had no effect on TGF-beta2 expression. Fluid streaming rather than thermal effects or cavitation was found to be the most likely explanation for the gene responses observed in vitro.

  1. Effects of beta-glucan addition to a probiotic containing yogurt.

    Science.gov (United States)

    Vasiljevic, T; Kealy, T; Mishra, V K

    2007-09-01

    This study investigated the effects of addition of beta-glucan from 2 different cereal sources (oat and barley) on growth and metabolic activity of Bifidobacterium animalis ssp. lactis (Bb-12) as determined by plating on a selective medium in yogurt during prolonged cold storage. These yogurt batches were compared to unsupplemented and inulin supplemented controls. All batches were also assessed for syneresis. Oat beta-glucan addition resulted in improved probiotic viability and stability comparable to that of inulin. It also enhanced lactic and propionic acid production. The barley beta-glucan addition suppressed proteolytic activity more than that from oat. These improvements were hindered by greater syneresis caused likely by thermodynamic incompatibility. Small amplitude oscillatory measurements of acidified model mixture of beta-glucan/skim milk solids showed formation of casein gel within the beta-glucan network. Binary mixtures of beta-glucan and skim milk solids had apparent pseudoplastic and non-Newtonian behavior governed mainly by beta-glucan contribution. Above critical concentrations, the mixtures underwent phase separation with the lower phase rich in protein. The phase diagram also showed that the addition of beta-glucan may be possible at or below 0.24 w/w%.

  2. Central effects of beta-endorphins on glucose homeostasis in the conscious dog

    Energy Technology Data Exchange (ETDEWEB)

    Radosevich, P.M.; Lacy, D.B.; Brown, L.L.; Williams, P.E.; Abumrad, N.N.

    1989-02-01

    The effects of centrally administered beta-endorphins on glucose homeostasis in the conscious dog were studied. Intracerebroventricular administration of beta-endorphin (0.2 mg/h) caused a 70% increase in plasma glucose. The mechanism of the hyperglycemia was twofold: there was an early increase in glucose production and a late inhibition of glucose clearance. These changes are explained by marked increases in plasma epinephrine (30-fold) and norepinephrine (6-fold) that occurred during infusion of beta-endorphin. Central administration of beta-endorphin also resulted in increased levels of adrenocorticotropic hormone and cortisol. In addition there was an increase in plasma insulin but no increase in plasma glucagon. Intravenous administration of beta-endorphin did not alter glucose homeostasis. Intracerebroventricular administration of acetylated beta-endorphin did not perturb glucose kinetics or any of the hormones that changed during infusion of the unacetylated peptide. We conclude that beta-endorphin acts centrally to cause hyperglycemia by stimulating sympathetic outflow and the pituitary-adrenal axis. Acetylation of beta-endorphin abolishes the in vivo activity of the peptide.

  3. Central effects of beta-endorphins on glucose homeostasis in the conscious dog

    International Nuclear Information System (INIS)

    Radosevich, P.M.; Lacy, D.B.; Brown, L.L.; Williams, P.E.; Abumrad, N.N.

    1989-01-01

    The effects of centrally administered beta-endorphins on glucose homeostasis in the conscious dog were studied. Intracerebroventricular administration of beta-endorphin (0.2 mg/h) caused a 70% increase in plasma glucose. The mechanism of the hyperglycemia was twofold: there was an early increase in glucose production and a late inhibition of glucose clearance. These changes are explained by marked increases in plasma epinephrine (30-fold) and norepinephrine (6-fold) that occurred during infusion of beta-endorphin. Central administration of beta-endorphin also resulted in increased levels of adrenocorticotropic hormone and cortisol. In addition there was an increase in plasma insulin but no increase in plasma glucagon. Intravenous administration of beta-endorphin did not alter glucose homeostasis. Intracerebroventricular administration of acetylated beta-endorphin did not perturb glucose kinetics or any of the hormones that changed during infusion of the unacetylated peptide. We conclude that beta-endorphin acts centrally to cause hyperglycemia by stimulating sympathetic outflow and the pituitary-adrenal axis. Acetylation of beta-endorphin abolishes the in vivo activity of the peptide

  4. Alpha and beta adrenergic effects on metabolism in contracting, perfused muscle

    DEFF Research Database (Denmark)

    Richter, Erik; Ruderman, N B; Galbo, H

    1982-01-01

    was obtained by epinephrine in a physiological concentration (2.4 X 10(-8) M) and alpha- and beta-adrenergic blockade by 10(-5) M phentolamine and propranolol, respectively. Epinephrine enhanced net glycogenolysis during contractions most markedly in slow-twitch red fibers. In these fibers the effect...... was mediated by alpha- as well as by beta-adrenergic stimulation, the latter involving production of cAMP, phosphorylase activation and synthase inactivation. In contrast, in fast-twitch fibers only beta-adrenergic mechanisms were involved in the glycogenolytic effect of epinephrine. Moreover, inactivation...

  5. Osteoprotegerin mediates tumor-promoting effects of Interleukin-1beta in breast cancer cells.

    Science.gov (United States)

    Chung, Stephanie Tsang Mui; Geerts, Dirk; Roseman, Kim; Renaud, Ashleigh; Connelly, Linda

    2017-02-01

    It is widely recognized that inflammation promotes breast cancer invasion and metastasis. Given the complex nature of the breast tumor inflammatory microenvironment, much remains to be understood of the molecular mechanisms that govern these effects. We have previously shown that osteoprotegerin knockdown in breast cancer cells resulted in reduced invasion and metastasis. Here we present novel insight into the role of osteoprotegerin in inflammation-driven tumor progression in breast cancer by investigating the link between osteoprotegerin, macrophages and the potent pro-inflammatory cytokine Interleukin-1beta. We used human breast cancer cell lines to investigate the effects of Interleukin-1beta treatment on osteoprotegerin secretion as measured by ELISA. We analyzed public datasets containing human breast cancer genome-wide mRNA expression data to reveal a significant and positive correlation between osteoprotegerin mRNA expression and the mRNA expression of Interleukin-1beta and of monocyte chemoattractant protein CC-chemokine ligand 2. Osteoprotegerin, Interleukin-1beta and CC-chemokine ligand 2 mRNA levels were also examined by qPCR on cDNA from normal and cancerous human breast tissue. We determined the effect of Interleukin-1beta-producing macrophages on osteoprotegerin expression by co-culturing breast cancer cells and differentiated THP-1 macrophages. Immunohistochemistry was performed on human breast tumor tissue microarrays to assess macrophage infiltration and osteoprotegerin expression. To demonstrate that osteoprotegerin mediated functional effects of Interleukin-1beta we performed cell invasion studies with control and OPG siRNA knockdown on Interleukin-1beta-treated breast cancer cells. We report that Interleukin-1beta induces osteoprotegerin secretion, independent of breast cancer subtype and basal osteoprotegerin levels. Co-culture of breast cancer cells with Interleukin-1beta-secreting macrophages resulted in a similar increase in osteoprotegerin

  6. Effects of gamma irradiation on the physical and structural properties of {beta}-glucan

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Eui-Hong [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Graduate School of Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of); Kim, Jae-Hun [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Sung, Nak-Yun [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Department of Food Science and Nutrition, Chungnam University, Daejon 305-764 (Korea, Republic of); Choi, Jong-il [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Lim, Seong-Taek [Graduate School of Biotechnology, Korea University, Seoul 136-701 (Korea, Republic of); Kim, Kwang-Hoon; Yook, Hong-Sun [Department of Food Science and Nutrition, Chungnam University, Daejon 305-764 (Korea, Republic of); Byun, Myung-Woo [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Lee, Ju-Woon [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: sjwlee@kaeri.re.kr

    2008-06-15

    This study was carried out to evaluate the effect of gamma irradiation on the physical and structural properties of {beta}-glucan. {beta}-Glucan solution (10%, w/v) was exposed to a cobalt-60 source (10, 30, and 50 kGy). Gel permeation chromatography data showed that the average molecular weight of irradiated {beta}-glucan significantly decreased as the irradiation dose increased. In addition, gamma irradiation improved the solubility and decreased the viscosity of {beta}-glucan by the radiolysis of the glycosidic bonds, and this effect was dependent upon the absorbed dose. Fourier transform infrared spectroscopy results showed that the functional groups of {beta}-glucan were not significantly affected by gamma irradiation. Scanning electron microscopy results showed that the irradiated {beta}-glucan was deformed into smaller granules. Therefore, gamma irradiation could be used in commercial processes as an effective method to resolve the physical problems involved in the use of {beta}-glucan with high viscosity and low solubility.

  7. 75 FR 4877 - In the Matter of Beta Gamma Nuclear Radiology; Confirmatory Order Modifying License (Effective...

    Science.gov (United States)

    2010-01-29

    ... Gamma Nuclear Radiology; Confirmatory Order Modifying License (Effective Immediately) I Beta Gamma Nuclear Radiology (BGNR) (Licensee) is the holder of medical License No. 52-25542-01, issued by the U.S...

  8. The ATM kinase signaling induced by the low-energy {beta}-particles emitted by {sup 33}P is essential for the suppression of chromosome aberrations and is greater than that induced by the energetic {beta}-particles emitted by {sup 32}P

    Energy Technology Data Exchange (ETDEWEB)

    White, Jason S.; Yue Ning [Department of Radiation Oncology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States); Hu Jing [Department of Pharmacology and Chemical Biology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States); Bakkenist, Christopher J., E-mail: bakkenistcj@upmc.edu [Department of Radiation Oncology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States); Department of Pharmacology and Chemical Biology, University of Pittsburgh Medical School, Hillman Cancer Center, Research Pavilion, Suite 2.6, 5117 Centre Avenue, Pittsburgh, PA 15213-1863 (United States)

    2011-03-15

    Ataxia-telangiectasia mutated (ATM) encodes a nuclear serine/threonine protein kinase whose activity is increased in cells exposed to low doses of ionizing radiation (IR). Here we examine ATM kinase activation in cells exposed to either {sup 32}P- or {sup 33}P-orthophosphate under conditions typically employed in metabolic labelling experiments. We calculate that the absorbed dose of IR delivered to a 5 cm x 5 cm monolayer of cells incubated in 2 ml media containing 1 mCi of the high-energy (1.70 MeV) {beta}-particle emitter {sup 32}P-orthophosphate for 30 min is {approx}1 Gy IR. The absorbed dose of IR following an otherwise identical exposure to the low-energy (0.24 MeV) {beta}-particle emitter {sup 33}P-orthophosphate is {approx}0.18 Gy IR. We show that low-energy {beta}-particles emitted by {sup 33}P induce a greater number of ionizing radiation-induced foci (IRIF) and greater ATM kinase signaling than energetic {beta}-particles emitted by {sup 32}P. Hence, we demonstrate that it is inappropriate to use {sup 33}P-orthophosphate as a negative control for {sup 32}P-orthophosphate in experiments investigating DNA damage responses to DNA double-strand breaks (DSBs). Significantly, we show that ATM accumulates in the chromatin fraction when ATM kinase activity is inhibited during exposure to either radionuclide. Finally, we also show that chromosome aberrations accumulate in cells when ATM kinase activity is inhibited during exposure to {approx}0.36 Gy {beta}-particles emitted by {sup 33}P. We therefore propose that direct cellular exposure to {sup 33}P-orthophosphate is an excellent means to induce and label the IR-induced, ATM kinase-dependent phosphoproteome.

  9. Effect of copper (II) ion against elongation behavior of amyloid {beta} fibrils on liposome membranes

    Energy Technology Data Exchange (ETDEWEB)

    Shimanouchi, T.; Onishi, R.; Kitaura, N.; Umakoshi, H.; Kuboi, R. [Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka (Japan)

    2012-01-15

    The fibril growth behavior of amyloid {beta} protein (A{beta}) on cell membranes is relating to the progression of Alzheimer's disease. This growth behavior of A{beta} fibrils is sensitively affected by the metal ions, neurotransmitters, or bioreactive substrate. The inhibitory effect of those materials was quantitatively estimated from the viewpoints of ''crystal growth''. In a bulk aqueous solution, copper (II) ion showed the strong inhibitory effect on the growth of A{beta} fibrils. Meanwhile, the addition of a closed-phospholipid bilayer membrane (liposome) could reduce the above inhibitory effect of copper (II) ion. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Effect of particle shapes on effective strain gradient of SiC particle reinforced aluminum composites

    Science.gov (United States)

    Liu, X.; Cao, D. F.; Mei, H.; Lei, Z. T.; Liu, L. S.

    2013-03-01

    The stress increments depend not only on the plastic strain but also on the gradient of plastic strain, when the characteristic length scale associated with non-uniform plastic deformation is on the order of microns. In the present research, the Taylor-based nonlocal theory of plasticity (TNT plasticity), with considering both geometrically necessary dislocations and statistically stored dislocations, is applied to investigated the effect of particle shapes on the strain gradient and mechanical properties of SiC particle reinforced aluminum composites (SiC/Al composites). Based on this theory, a two-dimensional axial symmetry cell model is built in the ABAQUS finite element code through its USER-ELEMENT (UEL) interface. Some comparisons with the classical plastic theory demonstrate that the effective stress predicted by TNT plasticity is obviously higher than that predicted by classical plastic theory. The results also demonstrate that the irregular particles cause higher effective gradient strain which is attributed to the fact that angular shape particles give more geometrically.

  11. Theoretical aspects of effects of high-energy particles on MHD modes

    International Nuclear Information System (INIS)

    Villard, L.; Brunner, S.; Vaclavik, J.

    1994-01-01

    In this paper we adopt a global approach. The TAEs are computed globally in true toroidal geometry consistent with an ideal MHD equilibrium. Kinetic effects (damping and driving mechanisms) and fast particles are treated perturbatively. More precisely, we first obtain the global eigenmodes an then use these given eigenmode fields to evaluate the global overall wave-particle power transfer assuming given fast particle density profiles. The marginal stability point is obtained by scaling the number of fast particles so that the overall power transfer is zero. The wave-particle power transfers are evaluated using the drift-kinetic equations. The paper is structured as follows: In section two, the plasma model in toroidal geometry is briefly presented. The expressions for the DKE powers are derived for the various species in the companion paper in these proceedings. In section 3 we show the results of our model applied to a wide variety of plasma parameters. In particular, the critical volume-averaged fast particle beta corresponding to marginal stability, f > cr , is calculated for a wide range of bulk plasma parameters and fast particle profile widths. We discuss the results in section 4 and draw some conclusions in section 5.(author) 13 figs., 21 refs

  12. Effect of Nano-Scale Roughness on Particle Wetting and on Particle-Mediated Emulsion Stability

    Science.gov (United States)

    San Miguel, Adriana; Behrens, Sven

    2012-02-01

    Colloidal particles can strongly adsorb to liquid interfaces and stabilize emulsions against droplet coalescence, the effectiveness of which depends crucially on the particle wettability. From the study of macroscopic solids, surface wetting is known to be influenced strongly by nano-scale roughness (as seen e.g. in the ``Lotus effect'' or in anti-fog coatings); similarly, strong effects of particle roughness on particle-stabilized emulsions should be expected. Here we report the first experimental study of particle wetting and particle-mediated emulsion stability in which particle roughness could be varied continuously without varying the surface chemistry. We demonstrate an enabling method for preparing particles and macroscopic substrates with tunable nano-roughness and correlate the extent of roughness quantitatively with surface wetting (measured via the three-phase contact angle) and with emulsion stability (quantifiable via the maximum capillary pressure). Our results confirm a dramatic influence of roughness on wetting, emulsion stability, and even the type of emulsion formed (o/w vs. w/o) upon mixing oil with an aqueous particle dispersion. Whether particle roughness benefits emulsion stability or not is seen to depend on both the size and shape of the surface features.

  13. Effects of TGF-betas and a specific antagonist on apoptosis of immature rat male germ cells in vitro.

    Science.gov (United States)

    Konrad, L; Keilani, M M; Laible, L; Nottelmann, U; Hofmann, R

    2006-05-01

    Massive apoptosis of pubertal male germ cells is important for the development of functional spermatogenesis in the adult testis. Although the trigger(s) for male germ cell loss at puberty remain undefined, we have hypothesized that transforming growth factor-betas (TGF-betas) play an active role. Here we demonstrate that the three mammalian TGF-beta isoforms, TGF-beta1, TGF-beta2 and TGF-beta3, induce distinct apoptosis of pubertal spermatogonia and spermatocytes in a dose-dependent manner. Induction of male germ cell death by activation of caspase-3 was most pronounced with TGF-beta2 compared to TGF-beta1 and TGF-beta3. Furthermore, we found colocalization of activated caspase-3 with apoptotic protease-activating factor-1 (Apaf-1) in apoptotic germ cells, thus indicating the importance of the intrinsic mitochondrial pathway in TGF-beta-induced apoptosis. The specificity of the TGF-beta effects was proven by addition of recombinant latency-associated peptide against TGF-beta1 (rLAP-TGF-beta1) which completely abolished TGF-beta1-induced and TGF-beta3-induced germ cell apoptosis. Although TGF-beta2-triggered germ cell death also was significantly reduced by rLAP-TGF-beta1, inhibition was not maximal. Our results suggest that the three TGF-beta isoforms induce apoptosis of pubertal male germ cells via the mitochondrial pathway in vitro and are thus likely candidates involved in the excessive first wave of apoptosis of male germ cells during puberty.

  14. Status of international benchmark experiment for effective delayed neutron fraction ({beta}eff)

    Energy Technology Data Exchange (ETDEWEB)

    Okajima, S.; Sakurai, T.; Mukaiyama, T. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-03-01

    To improve the prediction accuracy of the {beta}eff, the program of the international benchmark experiment (Beta Effect Reactor Experiment for a New International Collaborative Evaluation: BERNICE) was planned. This program composed of two parts; BERNICE-MASURCA and BERNICE-FCA. The former one was carried out in the fast critical facility MASURCA of CEA, FRANCE between 1993 and 1994. The latter one started in the FCA, JAERI in 1995 and still is going. In these benchmark experiments, various experimental techniques have been applied for in-pile measurements of the {beta}eff. The accuracy of the measurements was better than 3%. (author)

  15. The effect of oral supplementation with a combination of beta-hydroxy-beta-methylbutyrate, arginine and glutamine on wound healing: a retrospective analysis of diabetic haemodialysis patients

    OpenAIRE

    Sipahi, Savas; Gungor, Ozkan; Gunduz, Mehmet; Cilci, Mehmet; Demirci, Mustafa Cahit; Tamer, Ali

    2013-01-01

    Background Diabetes is an important reason for end-stage renal failure and diabetic foot wounds worsen the life qualities of these patients. Protein and amino acid support accelerates the wound healing. The purpose of this retrospective study is to examine the effect of beta-hydroxy-beta-methylbutyrate, arginine and glutamine (Abound?) supplementation on the wound healing. Methods A total of 11 diabetic dialysis patients were included in this retrospective study aiming to evaluate the effect ...

  16. The effects of cysteamine on thyrotropin and immunoreactive beta-endorphin secretion in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Millard, W.J.; Sagar, S.M.; Badger, T.M.; Carr, D.B.; Arnold, M.A.; Spindel, E.; Kasting, N.W.; Martin, J.B.

    1983-02-01

    We examined the effects of the thiol agent cysteamine (CSH), which is known to deplete the hypothalamus of immunoreactive somatostatin, on physiological TSH and beta- endorphin secretion in the adult male rat. CSH at doses of 90 and 300 mg/kg CSH produced a rapid decline in plasma TSH, whereas a dose of 30 mg/kg did not alter plasma TSH levels. After the higher doses of CSH, TSH levels in the blood remained lower than control values on day 2, but returned to normal by 1 week. This decrease in TSH within the plasma was not associated with a reduction in hypothalamic TRH concentrations. The TSH response to 500 ng/kg TRH was normal in CSH-treated animals. Blockade of norepinephrine synthesis with diethyldithiocarbamate (500 mg/kg) or fusaric acid (100 mg/kg) inhibited TSH secretion in a manner similar to that of CSH. beta-Endorphin-like immunoreactivity (bet-End-LI) was elevated in the plasma immediately after CSH (300 mg/kg) administration. This was associated with a 58% reduction in anterior pituitary beta-End-LI and no change in hypothalmic beta-End-LI. Plasma beta-End-LI returned to normal on day 2. The increase in plasma beta-End-LI induced by immobilization stress was not compromised by CSH treatment. The observed effects of CSH on both TSH and beta-End-LI are consistent with a reduction in central norepinephrine neurotransmission through the known actin of CSH to inhibit dopamine-beta-hydroxylase. Acute stress may play a role as well in the observed changes in TSH and beta-End-LI secretion.

  17. Measurement of the proton recoil spectrum in neutron beta decay with the spectrometer aSPECT. Study of systematic effects

    International Nuclear Information System (INIS)

    Konrad, Gertrud Emilie

    2012-01-01

    Free neutron decay, n→pe anti ν e , is the simplest nuclear beta decay, well described as a purely left-handed, vector minus axial-vector interaction within the framework of the Standard Model (SM) of elementary particles and fields. Due to its highly precise theoretical description, neutron beta decay data can be used to test certain extensions to the SM. Possible extensions require, e.g., new symmetry concepts like left-right symmetry, new particles, leptoquarks, supersymmetry, or the like. Precision measurements of observables in neutron beta decay address important open questions of particle physics and cosmology, and are generally complementary to direct searches for new physics beyond the SM in high-energy physics. In this doctoral thesis, a measurement of the proton recoil spectrum with the neutron decay spectrometer aSPECT is described. From the proton spectrum the antineutrinoelectron angular correlation coefficient a can be derived. In our first beam time at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz in Munich, Germany (2005-2006), background instabilities due to particle trapping and the electronic noise level of the proton detector prevented us from presenting a new value for a. In the latest beam time at the Institut Laue-Langevin (ILL) in Grenoble, France (2007-2008), the trapped particle background has been reduced sufficiently and the electronic noise problem has essentially been solved. For the first time, a silicon drift detector was used. As a result of the data analysis, we identified and fixed a problem in the detector electronics which caused a significant systematic error. The target figure of the latest beam time was a new value for a with a total relative error well below the present literature value of 4 %. A statistical accuracy of about 1.4% was reached, but we could only set upper limits on the correction of the problem in the detector electronics, which are too high to determine a meaningful result. The present doctoral

  18. Measurement of the proton recoil spectrum in neutron beta decay with the spectrometer aSPECT. Study of systematic effects

    Energy Technology Data Exchange (ETDEWEB)

    Konrad, Gertrud Emilie

    2012-01-24

    Free neutron decay, n{yields}pe anti {nu}{sub e}, is the simplest nuclear beta decay, well described as a purely left-handed, vector minus axial-vector interaction within the framework of the Standard Model (SM) of elementary particles and fields. Due to its highly precise theoretical description, neutron beta decay data can be used to test certain extensions to the SM. Possible extensions require, e.g., new symmetry concepts like left-right symmetry, new particles, leptoquarks, supersymmetry, or the like. Precision measurements of observables in neutron beta decay address important open questions of particle physics and cosmology, and are generally complementary to direct searches for new physics beyond the SM in high-energy physics. In this doctoral thesis, a measurement of the proton recoil spectrum with the neutron decay spectrometer aSPECT is described. From the proton spectrum the antineutrinoelectron angular correlation coefficient a can be derived. In our first beam time at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz in Munich, Germany (2005-2006), background instabilities due to particle trapping and the electronic noise level of the proton detector prevented us from presenting a new value for a. In the latest beam time at the Institut Laue-Langevin (ILL) in Grenoble, France (2007-2008), the trapped particle background has been reduced sufficiently and the electronic noise problem has essentially been solved. For the first time, a silicon drift detector was used. As a result of the data analysis, we identified and fixed a problem in the detector electronics which caused a significant systematic error. The target figure of the latest beam time was a new value for a with a total relative error well below the present literature value of 4 %. A statistical accuracy of about 1.4% was reached, but we could only set upper limits on the correction of the problem in the detector electronics, which are too high to determine a meaningful result. The present

  19. Differential effects of BMP-2 and TGF-beta1 on chondrogenic differentiation of adipose derived stem cells

    DEFF Research Database (Denmark)

    Mehlhorn, A T; Niemeyer, P; Kaschte, K

    2007-01-01

    OBJECTIVES: This article addresses the interaction of transforming growth factor beta1 (TGF-beta1) and bone morphogenic protein 2 (BMP-2) during osteo-chondrogenic differentiation of adipose-derived adult stem cells (ASC). TGF-beta1 was expected to modulate the BMP-2-induced effects through...

  20. Effect of mixing rate on Beta-carotene production and extraction by dunaliella salina in two-phase bioreactors

    NARCIS (Netherlands)

    Hejazi, M.; Andrysiewicz, E.; Tramper, J.; Wijffels, R.H.

    2003-01-01

    beta-Carotene has many applications in the food, cosmetic, and pharmaceutical industries; Dunaliella salina is currently the main source for natural beta-carotene. We have investigated the effect of mixing rate and whether it leads to the facilitated release of beta-carotene from the cells of

  1. Effects of Particles Collision on Separating Gas–Particle Two-Phase Turbulent Flows

    KAUST Repository

    Sihao, L. V.

    2013-10-10

    A second-order moment two-phase turbulence model incorporating a particle temperature model based on the kinetic theory of granular flow is applied to investigate the effects of particles collision on separating gas–particle two-phase turbulent flows. In this model, the anisotropy of gas and solid phase two-phase Reynolds stresses and their correlation of velocity fluctuation are fully considered using a presented Reynolds stress model and the transport equation of two-phase stress correlation. Experimental measurements (Xu and Zhou in ASME-FED Summer Meeting, San Francisco, Paper FEDSM99-7909, 1999) are used to validate this model, source codes and prediction results. It showed that the particles collision leads to decrease in the intensity of gas and particle vortices and takes a larger effect on particle turbulent fluctuations. The time-averaged velocity, the fluctuation velocity of gas and particle phase considering particles colli-sion are in good agreement with experimental measurements. Particle kinetic energy is always smaller than gas phase due to energy dissipation from particle collision. Moreover, axial– axial and radial–radial fluctuation velocity correlations have stronger anisotropic behaviors. © King Fahd University of Petroleum and Minerals 2013

  2. The effect of selected classical music and spontaneous imagery on plasma beta-endorphin.

    Science.gov (United States)

    McKinney, C H; Tims, F C; Kumar, A M; Kumar, M

    1997-02-01

    This study explored the effect of music and imagery on plasma beta-endorphin in 78 undergraduates. Subjects screened for relevant psychological and health criteria were assigned to music imaging, silent imaging, music listening, and control conditions. Subjects donated 15 ml of blood prior to and following the 2-hr intervention period. There were no group differences in potential confounding variables. Split-plot factorial analysis controlling for individual differences in pretest level of beta-endorphin revealed that those in the music imaging group experienced a significant pre-post decline in beta-endorphin, while no other group demonstrated any significant pre-post difference. These data suggest that music imaging may lower peripheral beta-endorphin levels in healthy subjects. Further exploration of the effects of music and imagery interventions on physiology and health may be warranted.

  3. Early and continuing effects of combined alpha and beta irradiation of the lung:

    Energy Technology Data Exchange (ETDEWEB)

    Scott, B.R.; Hahn, F.F.; Snipes, M.B.; Newton, G.J.; Eidson, A.F.; Mauderly, J.L.; Boecker, B.B.

    1988-03-01

    This report summarizes an inhalation exposure experiment that concerns early and continuing effects of combined alpha and beta irradiation of the lung of rats. Both morbidity at 18 months and mortality within 18 months after exposure were examined for rats exposed to the beta-emitter /sup 147/Pm, the alpha-emitter /sup 238/Pu, or both combined. The results were used to validate hazard-function models that were developed (1)for pulmonary functional morbidity at 18 months and (2) for lethality from radiation pneumonitis and pulmonary fibrosis within 18 months. Both models were found to adequately predict the experimental observations after combined chronic alpha and beta irradiation of the lung. A relative biological effectiveness of approximately 7 was obtained for /sup 238/Pu alpha radiation compared to /sup 147/Pm beta radiation for both pulmonary functional morbidity and lethality from radiation pneumonitis and pulmonary fibrosis. 12 refs., 16 figs., 11 tabs.

  4. Redistribution of retained particles. Effect of hyperpnea

    International Nuclear Information System (INIS)

    Valberg, P.A.; Wolff, R.K.; Mauderly, J.L.

    1985-01-01

    The effect of postexposure hyperpnea on clearance of particles deposited in the lungs of adult male beagle dogs was examined. Sedated dogs inhaled an insoluble 67 Gg 2 O 3 (T 1/2 . 78 h) aerosol (0.12 micron AMD) for one half hour on three separate occasions. Following aerosol exposures 1 and 2, dogs were assigned to either an eupneic (EUP) or hyperpneic (HYP) group and clearance was followed noninvasively for 9 days by whole body counting and gamma camera analysis. After exposure 2, EUP and HYP assignments were interchanged so that each dog was studied under both conditions. Hyperpnea was induced by housing dogs in an atmosphere of 7% CO 2 in air, 6 h per day. Carbon dioxide inhalation increased VE a factor of 3.7 +/- 0.9 (SD). The authors found that pulmonary clearance was retarded by CO 2 -stimulated hyperpnea in 7 of 8 dogs. Following aerosol exposure 3, dogs were divided between EUP and HYP and subsequently were killed in pairs at 3 h, 1 day, 3 days, and 7 days. Distribution of activity in body organs was examined, and translocation to the hilar lymph nodes was followed. Both retention distribution and removal of activity by saline lavage were measured in postmortem lungs. The percentage of lavaged activity associated with pulmonary macrophages increased from 44% at 3 h after exposure to 91% at 4 and 7 days after exposure. Examination of dried lung slices by autoradiography showed clearance of particles from airways and formation of a more punctate distribution in the retained activity at increasing times after exposure. Distinctive differences between HYP and EUP dogs were not seen

  5. Biological effect of low-dose application beta-radiation on the gingival mucosa of dogs

    International Nuclear Information System (INIS)

    Ippolitov, Yu.A.; Kovtun, N.N.; Timofeev, L.V.

    1999-01-01

    Biological effect of low-dose application beta-radiation on the gingival mucosa of dogs is studied. Obtained data illustrate the interactions between tissues in local exposure of live tissue to beta-radiation and determine the threshold total dose as 400 sGy. Higher doses lead to secondary changes in the gingival mucosa after which the tissue barrier does not recover [ru

  6. Effects of Two Surfactants and Beta-Cyclodextrin on Beta-Cypermethrin Degradation by Bacillus licheniformis B-1.

    Science.gov (United States)

    Zhao, Jiayuan; Chi, Yuanlong; Liu, Fangfang; Jia, Dongying; Yao, Kai

    2015-12-23

    The biodegradation efficiency of beta-cypermethrin (β-CY) is low especially at high concentrations mainly due to poor contact between this hydrophobic pesticide and microbial cells. In this study, the effects of two biodegradable surfactants (Tween-80 and Brij-35) and β-cyclodextrin (β-CD) on the growth and cell surface hydrophobicity (CSH) of Bacillus licheniformis B-1 were studied. Furthermore, their effects on the solubility, biosorption, and degradation of β-CY were investigated. The results showed that Tween-80 could slightly promote the growth of the strain while Brij-35 and β-CD exhibited little effect on its growth. The CSH of strain B-1 and the solubility of β-CY were obviously changed by using Tween-80 and Brij-35. The surfactants and β-CD could enhance β-CY biosorption and degradation by the strain, and the highest degradation was obtained in the presence of Brij-35. When the surfactant or β-CD concentration was 2.4 g/L, the degradation rate of β-CY in Brij-35, Tween-80, and β-CD treatments was 89.4%, 50.5%, and 48.1%, respectively. The half-life of β-CY by using Brij-35 was shortened by 69.1 h. Beta-CY content in the soil with both strain B-1 and Brij-35 decreased from 22.29 mg/kg to 4.41 mg/kg after incubation for 22 d. This work can provide a promising approach for the efficient degradation of pyrethroid pesticides by microorganisms.

  7. Photochemical reactions in dehydrated photosynthetic organisms, leaves, chloroplasts and photosystem II particles: reversible reduction of pheophytin and chlorophyll and oxidation of {beta}-carotene

    Energy Technology Data Exchange (ETDEWEB)

    Shuvalov, Vladimir A.; Heber, Ulrich

    2003-11-01

    Photoreactions of dehydrated leaves, isolated broken chloroplasts and PSII membrane fragments of spinach (Spinacia oleracea) were studied at different air humidities and compared with photoreactions of dry fronds of a fern, Polypodium vulgare, and a dry lichen, Parmelia sulcata, which in contrast to spinach are insensitive to photoinactivation in the dry state. Even in very dry air, P700 in the reaction center of photosystem I of dry leaves was oxidized, and the primary quinone acceptor Q{sub A} in the reaction center of photosystem II was photoreduced by low light. These reactions were only very slowly reversed in the dark and saturated under low light intensity. Light-minus-dark difference absorption spectra of the dry leaves, isolated chloroplasts and PSII membrane fragments measured at higher light intensities revealed absorbance changes of {beta}-carotene at 500 nm (light-dependent bleaching) and 980 nm (light-dependent band formation) and bleaching of chlorophyll at 436 and 680 nm with appearance of bands at 450 and 800 nm. Decrease of chlorophyll fluorescence upon strong illumination indicated photoaccumulation of a quencher. All these changes were kinetically related and readily reversible. They are interpreted to show light-induced oxidation of {beta}-carotene (Car) and reduction of chlorophyll-680 (Chl-680) in the reaction center of photosystem II of the dried leaves, chloroplasts and photosystem II particles. The fluorescence quencher was suggested to be Chl-680{sup -} or Car{sup +} in close proximity to P680, the primary electron donor. Appreciable photoaccumulation of reduced pheophytin was only observed in dry leaves after Q{sub A} reduction had been lost during heat treatment of hydrated leaves prior to dehydration. The observations are interpreted to show light-dependent cyclic electron flow within the reaction center of photosystem II in which Chl-680 (or Pheo) is reduced by P680* and Car is oxidized by P680{sup +} with consequent recombination of

  8. Particle size, magnetic field, and blood velocity effects on particle retention in magnetic drug targeting.

    Science.gov (United States)

    Cherry, Erica M; Maxim, Peter G; Eaton, John K

    2010-01-01

    A physics-based model of a general magnetic drug targeting (MDT) system was developed with the goal of realizing the practical limitations of MDT when electromagnets are the source of the magnetic field. The simulation tracks magnetic particles subject to gravity, drag force, magnetic force, and hydrodynamic lift in specified flow fields and external magnetic field distributions. A model problem was analyzed to determine the effect of drug particle size, blood flow velocity, and magnetic field gradient strength on efficiency in holding particles stationary in a laminar Poiseuille flow modeling blood flow in a medium-sized artery. It was found that particle retention rate increased with increasing particle diameter and magnetic field gradient strength and decreased with increasing bulk flow velocity. The results suggest that MDT systems with electromagnets are unsuitable for use in small arteries because it is difficult to control particles smaller than about 20 microm in diameter.

  9. Effects of chronic delta-9-THC treatment on cardiac beta-adrenoceptors in rats

    Energy Technology Data Exchange (ETDEWEB)

    Evans, E.B.; Seifen, E.; Kennedy, R.H.; Kafiluddi, R.; Paule, M.G.; Scallet, A.C.; Ali, S.F.; Slikker, W. Jr.

    1987-10-01

    This study was designed to determine if chronic treatment with delta-9-tetrahydrocannabinol (THC) alters cardiac beta-adrenoceptors in the rat. Following daily oral administration of 10 or 20 mg/kg THC or an equivalent volume of control solvent for 90 days, rats were sacrificed, and sarcolemmal membranes were prepared from ventricular myocardium. Beta-adrenoceptor density and binding affinity estimated with (-)(/sup 3/H)dihydroalprenolol; a beta-adrenergic antagonist, were not significantly affected by treatment with THC when compared to vehicle controls. These results suggest that the tolerance to cardiovascular effects of THC which develops during chronic exposure in the rat is not associated with alterations in cardiac beta-adrenoceptors as monitored by radiolabeled antagonist binding.

  10. The effects of glucagon-like peptide-1 on the beta cell

    DEFF Research Database (Denmark)

    Vilsbøll, Tina

    2009-01-01

    Type 2 diabetes is a progressive disease characterized by insulin resistance and impaired beta-cell function. Treatments that prevent further beta-cell decline are therefore essential for the management of type 2 diabetes. Glucagon-like peptide-1 (GLP-1) is an incretin hormone that is known...... to stimulate glucose-dependent insulin secretion. Furthermore, GLP-1 appears to have multiple positive effects on beta cells. However, GLP-1 is rapidly degraded by dipeptidyl peptidase-4 (DPP-4), which limits the clinical relevance of GLP-1 for the treatment of type 2 diabetes. Two main classes of GLP-1-based...... with type 2 diabetes, as assessed by homoeostasis model assessment-B analysis and proinsulin : insulin ratio. Additionally, liraglutide and exenatide are able to enhance first- and second-phase insulin secretion and are able to restore beta-cell sensitivity to glucose. Preclinical studies have shown...

  11. Physics of new methods of charged particle acceleration collective effects in dense charged particle ensembles

    CERN Document Server

    Bonch-Osmolovsky, A G

    1994-01-01

    This volume discusses the theory of new methods of charged particle acceleration and its physical and mathematical descriptions. It examines some collective effects in dense charged particle ensembles, and traces the history of the development of the field of accelerator physics.

  12. Beta-methyl-xyloside: positive effect on xylanase induction in Cellulomonas flavigena.

    Science.gov (United States)

    Hidalgo-Lara, Marìa Eugenia; Farrés, G S Amelia; Montes-Horcasitas, María Del Carmen

    2005-08-01

    Synthesis of extracellular xylanase in Cellulomonas flavigena is induced in the presence of xylan and sugarcane bagasse as substrates. The essential factors for efficient production of xylanase are the appropriate medium composition and an inducing substrate. The increase in xylanase production levels in C. flavigena were tested with a number of carbon sources and different culture conditions. Xylose, arabinose, glycerol and glucose did not induce xylanase production in this microorganism. beta-Methyl-xyloside (beta-mx), a structural analog of xylobiose, also did not induce xylanase when used as the sole carbon source, but when xylan or sugar cane bagasse was supplemented with beta-mx, extracellular xylanase production increased by 25 or 46%, respectively. The response of C. flavigena to xylan plus beta-mx was accompanied by a significant accumulation of reducing sugar, an effect not observed with the combination sugarcane bagasse plus beta-mx as substrate. To our knowledge, this is the first report on the effect of beta-mx on the induction of xylanase in C. flavigena.

  13. Effects of concomitant use of fibroblast growth factor (FGF)-2 with beta-tricalcium phosphate ({beta}-TCP) on the beagle dog 1-wall periodontal defect model

    Energy Technology Data Exchange (ETDEWEB)

    Anzai, Jun, E-mail: anzai_jun@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan); Kitamura, Masahiro, E-mail: kitamura@dent.osaka-u.ac.jp [Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nozaki, Takenori, E-mail: tnozaki@dent.osaka-u.ac.jp [Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nagayasu, Toshie, E-mail: nagayasu_toshie@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Terashima, Akio, E-mail: terashima_akio@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Asano, Taiji, E-mail: asano_taiji@kaken.co.jp [Pharmacology Department, Central Research Laboratories, Kaken Pharmaceutical Co., Ltd., 14, Shinomiya, Minamigawara-cho, Yamashina-ku, Kyoto 607-8042 (Japan); Murakami, Shinya, E-mail: ipshinya@dent.osaka-u.ac.jp [Department of Periodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2010-12-17

    Research highlights: {yields} Concomitant use of FGF-2 and {beta}-TCP (an osteo-conductive scaffold) significantly promotes periodontal regeneration in the severe periodontitis model (1-wall defect model) of beagle dog. {yields} FGF-2 enhanced new bone formation via {beta}-TCP at the defects. {yields} In particular, FGF-2 dramatically regenerated new periodontal ligament and cementum formations at the defects, that is one of the most important healing outcomes during the process of periodontal regeneration. {yields} Epithelial downgrowth (undesirable wound healing) was decreased by administration of FGF-2. {yields} This manuscript indicates for the first time that concomitant use of FGF-2 and {beta}-TCP is efficacious in regenerating periodontal tissue following severe destruction of the tissue by progression of periodontitis. -- Abstract: The effects of concomitant use of fibroblast growth factor-2 (FGF-2) and beta-tricalcium phosphate ({beta}-TCP) on periodontal regeneration were investigated in the beagle dog 1-wall periodontal defect model. One-wall periodontal defects were created in the mesial portion of both sides of the mandibular first molars, and 0.3% FGF-2 plus {beta}-TCP or {beta}-TCP alone was administered. Radiographic evaluation was performed at 0, 3, and 6 weeks. At 6 weeks, the periodontium with the defect site was removed and histologically analyzed. Radiographic findings showed that co-administration of FGF-2 significantly increased bone mineral contents of the defect sites compared with {beta}-TCP alone. Histologic analysis revealed that the length of the regenerated periodontal ligament, the cementum, distance to the junctional epithelium, new bone height, and area of newly formed bone were significantly increased in the FGF-2 group. No abnormal inflammatory response or ankylosis was observed in either group. These findings indicate the efficacy of concomitant use of FGF-2 and {beta}-TCP as an osteoconductive material for periodontal

  14. Beta Blockers

    Science.gov (United States)

    ... may not work as effectively for people of African heritage and older people, especially when taken without ... conditions/high-blood-pressure/in-depth/beta-blockers/ART-20044522 . Mayo Clinic Footer Legal Conditions and Terms ...

  15. Effective Lagrangians in elementary particle physics

    International Nuclear Information System (INIS)

    Trahern, C.G.

    1982-01-01

    Non-linear effective Lagrangians are constructed to represent the low energy phenomenology of elementary particles. As approximate descriptions of the dynamics of hadrons, these models simulate the expected (but unproven) behavior of more complex theories such as quantum Chromo-dynamics [QCD]. A general formalism for non-linear models was developed in the late 1960's by Coleman, Wess and Zumino. This dissertation utilizes and extends their work by incorporating some of the advances that have been made in the understanding of quantum field theories in the last decade. In particular the significance of spatial boundary conditions for interpreting the ground state behavior of the non-linear models is investigated. In addition the existence of a dual theory for the non-linear model is discussed. For experimental purposes duality refers to the possibility that in different enrgy regimes there may be wholly distinct kinds of excitations in the physical spectrum. Corresponding to these phenomenological distinctions are mutually exclusive mathematical descriptions. A familiar example is the duality of electric and magnetic charge in electro-dynamics. If magnetic charges do exist, they are expected to be extremely massive states that are unobservable up to very high energies. The analysis of such states within electrodynamics shows that one cannot describe both electric and magnetic charges without admitting the presence of singularities in the electric potential. A completely analogous form of duality is found and discussed for the non-linear models

  16. The effect of smoking cessation pharmacotherapies on pancreatic beta cell function

    International Nuclear Information System (INIS)

    Woynillowicz, Amanda K.; Raha, Sandeep; Nicholson, Catherine J.; Holloway, Alison C.

    2012-01-01

    The goal of our study was to evaluate whether drugs currently used for smoking cessation (i.e., nicotine replacement therapy, varenicline [a partial agonist at nicotinic acetylcholine receptors (nAChR)] and bupropion [which acts in part as a nAChR antagonist]) can affect beta cell function and determine the mechanism(s) of this effect. INS-1E cells, a rat beta cell line, were treated with nicotine, varenicline and bupropion to determine their effects on beta cell function, mitochondrial electron transport chain enzyme activity and cellular/oxidative stress. Treatment of INS-1E cells with equimolar concentrations (1 μM) of three test compounds resulted in an ablation of normal glucose-stimulated insulin secretion by the cells. This disruption of normal beta cell function was associated with mitochondrial dysfunction since all three compounds tested significantly decreased the activity of mitochondrial electron transport chain enzyme activity. These results raise the possibility that the currently available smoking cessation pharmacotherapies may also have adverse effects on beta cell function and thus glycemic control in vivo. Therefore whether or not the use of nicotine replacement therapy, varenicline and bupropion can cause endocrine changes which are consistent with impaired pancreatic function warrants further investigation. -- Highlights: ► Smoking cessation drugs have the potential to disrupt beta cell function in vitro. ► The effects of nicotine, varenicline and bupropion are similar. ► The impaired beta cell function is mediated by mitochondrial dysfunction. ► If similar effects are seen in vivo, these drugs may increase the risk of diabetes.

  17. The effect of smoking cessation pharmacotherapies on pancreatic beta cell function

    Energy Technology Data Exchange (ETDEWEB)

    Woynillowicz, Amanda K. [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Raha, Sandeep [Department of Pediatrics, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Nicholson, Catherine J. [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada); Holloway, Alison C., E-mail: hollow@mcmaster.ca [Department of Obstetrics and Gynecology, McMaster University, Hamilton, ON, Canada L8N 3Z5 (Canada)

    2012-11-15

    The goal of our study was to evaluate whether drugs currently used for smoking cessation (i.e., nicotine replacement therapy, varenicline [a partial agonist at nicotinic acetylcholine receptors (nAChR)] and bupropion [which acts in part as a nAChR antagonist]) can affect beta cell function and determine the mechanism(s) of this effect. INS-1E cells, a rat beta cell line, were treated with nicotine, varenicline and bupropion to determine their effects on beta cell function, mitochondrial electron transport chain enzyme activity and cellular/oxidative stress. Treatment of INS-1E cells with equimolar concentrations (1 μM) of three test compounds resulted in an ablation of normal glucose-stimulated insulin secretion by the cells. This disruption of normal beta cell function was associated with mitochondrial dysfunction since all three compounds tested significantly decreased the activity of mitochondrial electron transport chain enzyme activity. These results raise the possibility that the currently available smoking cessation pharmacotherapies may also have adverse effects on beta cell function and thus glycemic control in vivo. Therefore whether or not the use of nicotine replacement therapy, varenicline and bupropion can cause endocrine changes which are consistent with impaired pancreatic function warrants further investigation. -- Highlights: ► Smoking cessation drugs have the potential to disrupt beta cell function in vitro. ► The effects of nicotine, varenicline and bupropion are similar. ► The impaired beta cell function is mediated by mitochondrial dysfunction. ► If similar effects are seen in vivo, these drugs may increase the risk of diabetes.

  18. The clinical effect of neutralizing antibodies against interferon-beta is independent of the type of interferon-beta used for patients with relapsing-remitting multiple sclerosis

    DEFF Research Database (Denmark)

    Koch-Henriksen, N.; Sorensen, P.S.; Bendtzen, K.

    2009-01-01

    OBJECTIVE: To establish whether the clinical effect of neutralizing antibodies (NAbs) against interferon-beta (IFN beta) depends on the type of IFNbeta (1a or 1b) used for treatment of patients with relapsing-remitting multiple sclerosis (MS). INTRODUCTION: NAbs against IFN beta-1b appear faster...... was considered as NAb-positive. We used a mixed logistic regression analysis in which NAb-status (three levels), IFN beta-preparation, and time since treatment started were included as explanatory variables, and relapse rate as response variable. RESULTS: In 1,309 patients, who were observed for 21,958 months......, 32.3% were classified as NAb-positive. The odds-ratio (OR) for relapses in NAb-positive months compared with NAb-negative months was 1.25; P = 0.02. The risk of relapses was higher with Betaferon than with Rebif22 (OR 1.26; P independent of whether...

  19. The effect of beta-adrenergic blockade after encoding on memory of an emotional event.

    Science.gov (United States)

    van Stegeren, Anda H; Everaerd, Walter; Gooren, Louis J G

    2002-09-01

    Animal and human studies lend support to the hypothesis that enhanced memory associated with emotional experiences involves activation of the beta-adrenergic system. Evidence for the role of noradrenaline in emotional memory in humans has been gathered from experimental studies where blockade of the beta-adrenergic system with a beta-blocker selectively impaired long-term memory for an emotionally arousing story (a slide show), when the beta-blocker was given before subjects were confronted with the emotional stimuli. The purpose of this study was to test whether effective beta-adrenergic blockade occurring only after the stage of encoding has a similar impairing effect on memory. In a double blind experimental design, 60 healthy adult subjects received randomly one tablet of either propranolol (Inderal, 40 mg) or placebo. Drugs were administered just before the slide show begun and (in view of its pharmacokinetics) propranolol reaches peak levels 1 h after drug intake. Physiological arousal was monitored by heart rate and blood pressure. Half of the beta-blocker and placebo groups watched either a neutral or an arousal version of an 11-slide presentation. Memory performance was tested with a surprise free recall and recognition test 1 week later. Memory performance, specifically for the second phase in which emotional elements were introduced, was better in subjects who viewed the arousal version than subjects who saw the neutral version of the slide show. However, no effect of the beta-blocker condition was found. This experiment does not support a role for noradrenaline in the post-encoding phase and on the later processes of consolidation and retrieval. Although it remains possible that with a different dosage or timing protocol a post-treatment effect of noradrenaline in humans can be found, this experiment could not find support for it.

  20. Adrenoceptor blocking effects of arotinolol, a new combined alpha- and beta-adrenoceptor blocking agent.

    Science.gov (United States)

    Miyagishi, A; Nakahara, H; Hara, Y

    1984-10-01

    In isolated tissues and anesthetized animals, beta- and alpha-adrenoceptor blocking properties of arotinolol were studied in comparison with those of other typical adrenoceptor antagonists. The following order of beta-adrenoceptor blocking activities were obtained in isolated tissues: arotinolol = pindolol greater than propranolol = oxprenolol = alprenolol greater than or equal to labetalol for beta 1-adrenoceptors (guinea-pig right atrium) and pindolol = oxprenolol = arotinolol greater than propranolol greater than labetalol for beta 2-adrenoceptors (guinea-pig trachea). In anesthetized cats, arotinolol was about 9 and 25 times more potent than propranolol, about 30 and 100 times more potent than labetalol in blocking beta 1- and beta 2-adrenoceptors, respectively. Furthermore arotinolol showed a competitive antagonistic effect on phenylephrine-induced contraction of isolated rat aortic strips. The relative order of alpha 1-adrenoceptor blocking potencies was as follows: prazosin greater than phentolamine greater than labetalol greater than arotinolol = yohimbine. Presynaptic alpha 2-adrenoceptor blocking action of arotinolol was also assessed in isolated rat vas deferens and arotinolol was revealed to be a much weaker presynaptic alpha 2-adrenoceptor antagonist. In anesthetized rats arotinolol was 4-5 times less potent than labetalol and about 26 times less potent than phentolamine in blocking alpha 1-adrenoceptors. Thus, as for the selectivity for 2 subtypes of alpha-adrenoceptors, arotinolol showed a selectivity for alpha 1-adrenoceptors over presynaptic alpha 2-adrenoceptors.

  1. Differential effects of 3 beta blockers on lipid peroxidation in hyperthyroid muscle.

    Science.gov (United States)

    Asayama, K; Hayashibe, H; Dobashi, K; Kato, K

    1990-08-01

    To determine whether beta blockade protects against the acceleration of lipid peroxidation in hyperthyroid rat soleus (slow-oxidative) muscle, in vivo chronic (3 weeks) effects of 3 beta blockers with different ancillary properties on mitochondrial oxidative enzymes, antioxidant enzymes, and thiobarbituric acid-reactive substances were investigated. The rats were rendered hyperthyroid by the administration of thyroxine and treated simultaneously with either carteolol (a nonselective blocker with partial agonist activity; 30 mg/kg/day), atenolol (a beta 1-selective blocker; 50 mg/kg/day), or arotinolol (a nonselective blocker with weak alpha-blocking action; 50 mg/kg/day) over a 3 week period. Hyperthyroidism induced tachycardia, an increase in the mitochondrial oxidative enzymes, manganese (mitochondrial) superoxide dismutase and thiobarbituric acid-reactive substances, and a decrease in the other antioxidant enzymes. The tachycardia was alleviated completely by either atenolol or arotinolol, but partially by carteolol. Arotinolol, but neither carteolol nor atenolol, inhibited the increase in oxidative enzymes and thiobarbituric acid-reactive substances. The levels of antioxidant enzymes were minimally affected by the beta-blocker treatment. Beta 2-, and possibly alpha- as well, but not beta 1-, blockade suppressed mitochondrial hypermetabolism and protected against peroxidative injury in the hyperthyroid soleus muscle. Partial agonist activity was not beneficial.

  2. Effects of stress and. beta. -funal trexamine pretreatment on morphine analgesia and opioid binding in rats

    Energy Technology Data Exchange (ETDEWEB)

    Adams, J.U.; Andrews, J.S.; Hiller, J.M.; Simon, E.J.; Holtzman, S.G.

    1987-12-28

    This study was essentially an in vivo protection experiment designed to test further the hypothesis that stress induces release of endogenous opiods which then act at opioid receptors. Rats that were either subjected to restraint stress for 1 yr or unstressed were injected ICV with either saline or 2.5 ..mu..g of ..beta..-funaltrexamine (..beta..-FNA), an irreversible opioid antagonist that alkylates the mu-opioid receptor. Twenty-four hours later, subjects were tested unstressed for morphine analgesia or were sacrificed and opioid binding in brain was determined. (/sup 3/H)D-Ala/sup 2/NMePhe/sup 4/-Gly/sup 5/(ol)enkephalin (DAGO) served as a specific ligand for mu-opioid receptors, and (/sup 3/H)-bremazocine as a general ligand for all opioid receptors. Rats injected with saline while stressed were significantly less sensitive to the analgesic action of morphine 24 hr later than were their unstressed counterparts. ..beta..-FNA pretreatment attenuated morphine analgesia in an insurmountable manner. Animals pretreated with ..beta..-FNA while stressed were significantly more sensitive to the analgesic effect of morphine than were animals that received ..beta..-FNA while unstressed. ..beta..-FNA caused small and similar decreases in (/sup 3/H)-DAGO binding in brain of both stressed and unstressed animals. 35 references, 2 figures, 2 tables.

  3. The Effect of Particle Properties on Hot Particle Spot Fire Ignition

    Science.gov (United States)

    Zak, Casey David

    The ignition of natural combustible material by hot metal particles is an important fire ignition pathway by which wildland and wildland-urban-interface spot fires are started. There are numerous cases reported of wild fires started by clashing power-lines or from sparks generated by machines or engines. Similarly there are many cases reported of fires caused by grinding, welding and cutting sparks. Up to this point, research on hot particle spot fire ignition has largely focused on particle generation and transport. A small number of studies have examined what occurs after a hot particle contacts a natural fuel bed, but until recently the process remained poorly understood. This work describes an investigation of the effect of particle size, temperature and thermal properties on the ability of hot particles to cause flaming ignition of cellulosic fuel beds. Both experimental and theoretical approaches are used, with a focus on understanding the physics underlying the ignition process. For the experimental study, spheres of stainless steel, aluminum, brass and copper are heated in a tube furnace and dropped onto a powdered cellulose fuel bed; the occurrence of flaming ignition or lack thereof is visually observed and recorded. This procedure is repeated a large number of times for each metal type, varying particle diameter from 2 to 11 mm and particle temperature between 575 and 1100°C. The results of these experiments are statistically analyzed to find approximate ignition boundaries and identify boundary trends with respect to the particle parameters of interest. Schlieren images recorded during the ignition experiments are also used to more accurately describe the ignition process. Based on these images, a simple theoretical model of hot particle spot fire ignition is developed and used to explore the experimental trends further. The model under-predicts the minimum ignition temperatures required for small spheres, but agrees qualitatively with the experimental

  4. TGF-beta1 release from biodegradable polymer microparticles: its effects on marrow stromal osteoblast function

    Science.gov (United States)

    Lu, L.; Yaszemski, M. J.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

    2001-01-01

    BACKGROUND: Controlled release of transforming growth factor-beta1 (TGF-beta1) to a bone defect may be beneficial for the induction of a bone regeneration cascade. The objectives of this work were to assess the feasibility of using biodegradable polymer microparticles as carriers for controlled TGF-beta1 delivery and the effects of released TGF-beta1 on the proliferation and differentiation of marrow stromal cells in vitro. METHODS: Recombinant human TGF-beta1 was incorporated into microparticles of blends of poly(DL-lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG). Fluorescein isothiocynate-labeled bovine serum albumin (FITC-BSA) was co-encapsulated as a porogen. The effects of PEG content (0, 1, or 5% by weight [wt%]) and buffer pH (3, 5, or 7.4) on the protein release kinetics and the degradation of PLGA were determined in vitro for as long as 28 days. Rat marrow stromal cells were seeded on a biodegradable poly(propylene fumarate) (PPF) substrate. The dose response and biological activity of released TGF-beta1 was determined after 3 days in culture. The effects of TGF-beta1 released from PLGA/PEG microparticles on marrow stromal cell proliferation and osteoblastic differentiation were assessed during a 21-day period. RESULTS: TGF-beta1 was encapsulated along with FITC-BSA into PLGA/PEG blend microparticles and released in a multiphasic fashion including an initial burst for as long as 28 days in vitro. Increasing the initial PEG content resulted in a decreased cumulative mass of released proteins. Aggregation of FITC-BSA occurred at lower buffer pH, which led to decreased release rates of both proteins. The degradation of PLGA was increased at higher PEG content and significantly accelerated at acidic pH conditions. Rat marrow stromal cells cultured on PPF substrates showed a dose response to TGF-beta1 released from the microparticles similar to that of added TGF-beta1, indicating that the activity of TGF-beta1 was retained during microparticle

  5. Numerical investigation of adhesion effects on solid particles filtration efficiency

    Science.gov (United States)

    Shaffee, Amira; Luckham, Paul; Matar, Omar K.

    2017-11-01

    Our work investigate the effectiveness of particle filtration process, in particular using a fully-coupled Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) approach involving poly-dispersed, adhesive solid particles. We found that an increase in particle adhesion reduces solid production through the opening of a wire-wrap type filter. Over time, as particle agglomerates continuously deposit on top of the filter, layer upon layer of particles is built on top of the filter, forming a particle pack. It is observed that with increasing particle adhesion, the pack height build up also increases and hence decreases the average particle volume fraction of the pack. This trend suggests higher porosity and looser packing of solid particles within the pack with increased adhesion. Furthermore, we found that the pressure drop for adhesive case is lower compared to non-adhesive case. Our results suggest agglomerating solid particles has beneficial effects on particle filtration. One important application of these findings is towards designing and optimizing sand control process for a hydrocarbon well with excessive sand production which is major challenge in oil and gas industry. Funding from PETRONAS and RAEng UK for Research Chair (OKM) gratefully acknowledged.

  6. Dynamic Flow Impacts Cell-Particle Interactions: Sedimentation and Particle Shape Effects.

    Science.gov (United States)

    Björnmalm, Mattias; Faria, Matthew; Chen, Xi; Cui, Jiwei; Caruso, Frank

    2016-10-17

    The interaction of engineered particles with biological systems determines their performance in biomedical applications. Although standard static cell cultures remain the norm for in vitro studies, modern models mimicking aspects of the dynamic in vivo environment have been developed. Herein, we investigate fundamental cell-particle interactions under dynamic flow conditions using a simple and self-contained device together with standard multiwell cell culture plates. We engineer two particle systems and evaluate their cell interactions under dynamic flow, and we compare the results to standard static cell cultures. We find substantial differences between static and dynamic flow conditions and attribute these to particle shape and sedimentation effects. These results demonstrate how standard static assays can be complemented by dynamic flow assays for a more comprehensive understanding of fundamental cell-particle interactions.

  7. Effects of beta-alanine supplementation and interval training on physiological determinants of severe exercise performance.

    Science.gov (United States)

    Gross, Micah; Boesch, Chris; Bolliger, Christine S; Norman, Barbara; Gustafsson, Thomas; Hoppeler, Hans; Vogt, Michael

    2014-02-01

    We aimed to manipulate physiological determinants of severe exercise performance. We hypothesized that (1) beta-alanine supplementation would increase intramuscular carnosine and buffering capacity and dampen acidosis during severe cycling, (2) that high-intensity interval training (HIT) would enhance aerobic energy contribution during severe cycling, and (3) that HIT preceded by beta-alanine supplementation would have greater benefits. Sixteen active men performed incremental cycling tests and 90-s severe (110 % peak power) cycling tests at three time points: before and after oral supplementation with either beta-alanine or placebo, and after an 11-days HIT block (9 sessions, 4 × 4 min), which followed supplementation. Carnosine was assessed via MR spectroscopy. Energy contribution during 90-s severe cycling was estimated from the O2 deficit. Biopsies from m. vastus lateralis were taken before and after the test. Beta-alanine increased leg muscle carnosine (32 ± 13 %, d = 3.1). Buffering capacity and incremental cycling were unaffected, but during 90-s severe cycling, beta-alanine increased aerobic energy contribution (1.4 ± 1.3 %, d = 0.5), concurrent with reduced O2 deficit (-5.0 ± 5.0 %, d = 0.6) and muscle lactate accumulation (-23 ± 30 %, d = 0.9), while having no effect on pH. Beta-alanine also enhanced motivation and perceived state during the HIT block. There were no between-group differences in adaptations to the training block, namely increased buffering capacity (+7.9 ± 11.9 %, p = 0.04, d = 0.6, n = 14) and glycogen storage (+30 ± 47 %, p = 0.04, d = 0.5, n = 16). Beta-alanine did not affect buffering considerably, but has beneficial effects on severe exercise metabolism as well as psychological parameters during intense training phases.

  8. Effects of radioactive hot particles on pig skin

    International Nuclear Information System (INIS)

    Kaurin, D.G.; Baum, J.W.; Schaefer, C.W.

    1997-06-01

    The purpose of these studies was to determine the incidence and severity of lesions resulting from very localized deposition of dose to skin from small ( 2 at 70 μm depth unless noted otherwise) using Sc-46, Yb-175, Tm-170, and fissioned UC 2 isotopes having maximum beta-particle energies from about 0.3 to 3 MeV. Erythema and scabs (indicating ulceration) were scored for up to 71 days post-irradiation. The responses followed normal cumulative probability distributions, and therefore, no true threshold could be defined. Hence, 10 and 50% scab incidence rates were deduced using probit analyses. The lowest dose which produced 10% incidence was about 1 Gy for Yb-175 (0.5 MeV maximum energy) beta particle exposures, and about 3 to 9 Gy for other isotopes. The histopathology of lesions was determined at several doses. Single exposures to doses as large as 1,790 Gy were also given, and results were observed for up to 144 days post-exposure. Severity of detriment was estimated by analyzing the results in terms of lesion diameter, persistence, and infection. Over 1,100 sites were exposed. Only two exposed sites became infected after doses near 5000 Gy; the lesions healed quickly on treatment. 105 refs., 145 figs., 47 tabs

  9. Effect of. beta. -endorphin on catecholamine levels in rat hypothalamus and cerebral cortex

    Energy Technology Data Exchange (ETDEWEB)

    Slavnov, V.N.; Valueva, G.V.; Markov, V.V.; Luchitskii, E.V.

    1986-10-01

    The authors studied the effect of beta-endorphin on catecholamine concentrations in the hypothalmus and cerebral cortex in rats, as a contribution to the explanation of the mechanism of action of this peptide on certain pituitary trophic functions. Concentrations of dopamine, noradrenalin, and adrenalin were determined by a radioenzymatic method. A Mark 3 scintillation system was used for radiometric investigation of the samples. The results of these experiments indicate that beta-endorphin has a marked effect on brain catecholamine levels mainly in the hypothalamus.

  10. The modulatory effect of adaptive deep brain stimulation on beta bursts in Parkinson's disease.

    Science.gov (United States)

    Tinkhauser, Gerd; Pogosyan, Alek; Little, Simon; Beudel, Martijn; Herz, Damian M; Tan, Huiling; Brown, Peter

    2017-04-01

    Adaptive deep brain stimulation uses feedback about the state of neural circuits to control stimulation rather than delivering fixed stimulation all the time, as currently performed. In patients with Parkinson's disease, elevations in beta activity (13-35 Hz) in the subthalamic nucleus have been demonstrated to correlate with clinical impairment and have provided the basis for feedback control in trials of adaptive deep brain stimulation. These pilot studies have suggested that adaptive deep brain stimulation may potentially be more effective, efficient and selective than conventional deep brain stimulation, implying mechanistic differences between the two approaches. Here we test the hypothesis that such differences arise through differential effects on the temporal dynamics of beta activity. The latter is not constantly increased in Parkinson's disease, but comes in bursts of different durations and amplitudes. We demonstrate that the amplitude of beta activity in the subthalamic nucleus increases in proportion to burst duration, consistent with progressively increasing synchronization. Effective adaptive deep brain stimulation truncated long beta bursts shifting the distribution of burst duration away from long duration with large amplitude towards short duration, lower amplitude bursts. Critically, bursts with shorter duration are negatively and bursts with longer duration positively correlated with the motor impairment off stimulation. Conventional deep brain stimulation did not change the distribution of burst durations. Although both adaptive and conventional deep brain stimulation suppressed mean beta activity amplitude compared to the unstimulated state, this was achieved by a selective effect on burst duration during adaptive deep brain stimulation, whereas conventional deep brain stimulation globally suppressed beta activity. We posit that the relatively selective effect of adaptive deep brain stimulation provides a rationale for why this approach could

  11. Effect of Nɛ-carboxymethyllysine on oxidative stress and the glutathione system in beta cells

    Directory of Open Access Journals (Sweden)

    Daniëlle M.P.H.J. Boesten

    2014-01-01

    Full Text Available One of the pathways involved in the pathogenesis of diabetic complications is the formation of excessive levels of advanced glycation end (AGE products. Nɛ-carboxymethyllysine (CML is one of the best-characterized AGEs. Because little is known about the effects of AGEs on pancreatic beta cells, we investigated the effect of CML on human pancreatic cells and determined the activity and gene expression of glutathione system components. CML at a concentration of 0.5 mM induced cell death in human pancreatic beta cells, which was accompanied by increased intracellular oxidative stress. No changes in the gene expression of the receptor for AGEs (RAGE were found, although an increase in the level of a target cytokine of RAGE after CML exposure was observed. Additionally we found that CML lowered the levels of GSH and affected the activity and expression of other components of the glutathione system. These changes indicate that the cells are even more vulnerable for oxidative stress after exposure to CML. Since beta cells are low in antioxidant enzymes and repair for oxidized DNA, CML, but most likely also other AGEs, accelerates beta cell dysfunction and increases beta cell death during chronic hyperglycemia.

  12. Effects of transforming growth factor beta 1 on the regulation of osteoclastic development and function

    International Nuclear Information System (INIS)

    Hattersley, G.; Chambers, T.J.

    1991-01-01

    Transforming growth factor (TGF) beta 1 is a multifunctional cytokine with powerful effects on osteoblastic cells. Its role in the regulation of osteoclast generation and function, however, is unclear. It has been reported both to stimulate and to inhibit resorption in organ culture and to inhibit multinuclear cell formation in bone marrow cultures. We tested the effects of TGF-beta 1 on bone resorption by osteoclasts isolated from neonatal rat long bones. We found potent stimulation of osteoclastic bone resorption, mediated by osteoblastic cells, with an EC50 of 10 pg/ml, considerably lower than that of well-documented osteotropic hormones. Stimulation was not mediated by Swiss mouse 3T3 cells, a nonosteoblastic cell line. TGF-beta 1 strongly inhibited the generation of calcitonin receptor (CTR)-positive cells in mouse bone marrow cultures, but as for isolated osteoclasts, bone resorption per CTR-positive cell was increased. The inhibition of CTR-positive cell formation was associated with suppression of maturation of other bone marrow derivatives and may be related more to the known ability of TGF-beta 1 to suppress the proliferation of primitive hematopoietic cells than to a specific role of TGF-beta 1 in osteoclast generation

  13. The effects of Tai Chi practice on intermuscular beta coherence and the rubber hand illusion

    Directory of Open Access Journals (Sweden)

    Catherine eKerr

    2016-02-01

    Full Text Available Tai Chi (TC is a slow-motion contemplative exercise that is associated with improvements in sensorimotor measures, including decreased force variability, enhanced tactile acuity, and improved proprioception, especially in elderly populations. Here, we carried out two studies evaluating the effect of TC practice on measures associated with sensorimotor processing. In study 1, we evaluated TC’s effects on an oscillatory parameter associated with motor function, beta rhythm (15-30 Hz coherence, focusing specifically on beta rhythm intermuscular coherence (IMC, which is tightly coupled to beta corticomuscular coherence (CMC. We utilized electromyography (EMG to compare beta IMC in older TC practitioners with age-matched controls, as well as novices with advanced TC practitioners. Given previous findings of elevated, maladaptive beta coherence in older subjects, we hypothesized that increased TC practice would be associated with a monotonic decrease in beta IMC, but rather discovered that novice practitioners manifested higher beta IMC than both controls and advanced practitioners, forming an inverted U-shaped practice curve. This finding suggests that TC practice elicits complex changes in sensory and motor processes over the developmental lifespan of TC training. In study 2, we focused on somatosensory (e.g., tactile and proprioceptive responses to the Rubber Hand Illusion (RHI in a middle-aged TC group, assessing whether responses to the illusion became dampened with greater cumulative practice. As hypothesized, TC practice was associated with decreased likelihood to misattribute tactile stimulation during the RHI to the rubber hand, although there was no effect of TC practice on measures of proprioception or on subjective reports of ownership. These studies provide preliminary evidence that TC practice modulates beta network coherence in a non-linear fashion, perhaps as a result of the focus on not only efferent motor but also afferent sensory

  14. Effects of q and high beta on tokamak stability

    International Nuclear Information System (INIS)

    Brickhouse, N.S.; Callen, J.D.; Dexter, R.N.

    1984-08-01

    In the Columbia University Torus II tokamak plasmas have been studied with volume averaged toroidal beta values as high as 15%. Experimental equilibria have been compared with a 2D free boundary MHD equilibrium code PSEC. The stability of these equilibria has been computed using PEST, the predictions of which are compatible with an observed instability in Torus II which may be characterized as a high toroidal mode number ballooning fluctuation. In the University of Wisconsin Tokapole II tokamak disruptive instability behavior is investigated, with plasma able to be confined on closed magnetic surfaces in the scrape-off region, as the cylindrical edge safety factor is varied from q approx. 3 to q approx. 0.5. It is observed that at q/sub a/ approx. 3 major disruption activity occurs without current terminations, at q/sub a/ less than or equal to 2 well-confined plasmas are obtained without major disruption, and at q/sub a/ approx. 0.5 only partial reconnection accompanies minor disruptions

  15. Effects of charged particles on human tumor cells

    Directory of Open Access Journals (Sweden)

    Kathryn D Held

    2016-02-01

    Full Text Available The use of charged particle therapy in cancer treatment is growing rapidly, in large part because the exquisite dose localization of charged particles allows for higher radiation doses to be given to tumor tissue while normal tissues are exposed to lower doses and decreased volumes of normal tissues are irradiated. In addition, charged particles heavier than protons have substantial potential clinical advantages because of their additional biological effects including greater cell killing effectiveness, decreased radiation resistance of hypoxic cells in tumors and reduced cell cycle dependence of radiation response. These biological advantages depend on many factors such as endpoint, cell or tissue type, dose, dose rate or fractionation, charged particle type and energy, and oxygen concentration. This review summarizes the unique biological advantages of charged particle therapy and highlights recent research and areas of particular research needs, such as quantification of Relative Biological Effectiveness (RBE for various tumor types and radiation qualities, role of genetic background of tumor cells in determining response to charged particles, sensitivity of cancer stem-like cells to charged particles, role of charged particles in tumors with hypoxic fractions and importance of fractionation, including use of hypofractionation, with charged particles.

  16. Effective dielectric response of dispersions of graded particles

    Science.gov (United States)

    Sushko, M. Ya.

    2017-12-01

    Based upon our compact group approach and the Hashin-Shtrikman variational theorem, we propose a solution, which effectively incorporates many-particle effects in concentrated systems, to the problem of the effective quasistatic permittivity of dispersions of graded dielectric particles. After the theory is shown to recover existing analytical results and simulation data for dispersions of hard dielectric spheres with power-law permittivity profiles, we use it to describe the effective dielectric response of nonconducting polymer-ceramic composites modeled as dispersions of dielectric core-shell particles. Possible generalizations of the results are specified.

  17. Highly effective portable beta spectrometer for precise depth selective electron Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Aldiyarov, N.U.; Kadyrzhanov, K.K.; Seytimbetov, A.M.; Zhdanov, V.S.

    2007-01-01

    Full text: More broad application of the nuclear-physical method of precise Depth Selective Electron Moessbauer Spectroscopy (DS EMS) is limited by insufficient accessibility of highly-effective beta spectrometers with acceptable resolution. It should be mentioned that the method DS EMS is realized at a combined installation that consists of a highly-effective beta spectrometer and a conventional portable nuclear gamma-resonance spectrometer. Yet few available beta spectrometers have sophisticated design and controlling; in most cases they are cumbersome. All the attempts to simplify beta spectrometers resulted in noticeable worsening of depth resolution for the DS EMS method making the measurements non precise. There is currently an obvious need in a highly-effective portable easily controlled beta spectrometer. While developing such portable beta spectrometer, it is more promising to use as basis a simpler spectrometer, which has ratio of sample size to spectrometer size of about five times. The paper presents an equal-arm version of a highly-effective portable beta spectrometer with transverse heterogeneous sector magnetic field that assures double focusing. The spectrometer is equipped with a large-area non-equipotential source (a sample under investigation) and a position-sensitive detector. This portable spectrometer meets all requirements for achievement of the DS EMS depth resolution close to the physical limit and demonstrates the following main characteristics: equilibrium orbit radius ρ 0 = 80 mm, instrumental energy resolution 0.6 % at solid angle 1 % of 4π steradian, area of non-equipotential source ∼ 80 mm 2 , registration by position-sensitive detector of ∼ 10 % of the energy interval. Highly-effective portable beta spectrometer assures obtaining Moessbauer data with depth resolution close to physical limit of the DS EMS method. So in measurements at conversion and Auger electrons with energies of about units of keV and above, the achieved

  18. Effect of low-molecular-weight beta-cyclodextrin polymer on release of drugs from mucoadhesive buccal film dosage forms.

    Science.gov (United States)

    Arakawa, Yotaro; Kawakami, Shigeru; Yamashita, Fumiyoshi; Hashida, Mitsuru

    2005-09-01

    We investigated the effect of low-molecular-weight beta-cyclodextrin (beta-CyD) polymer on in vitro release of two drugs with different lipophilicities (i.e., lidocaine and ketoprofen) from mucoadhesive buccal film dosage forms. When beta-CyD polymer was added to hydroxypropylcellulose (HPC) or polyvinylalcohol (PVA) film dosage forms, the release of lidocaine into artificial saliva (pH 5.7) was reduced by 40% of the control. In contrast, the release of ketoprofen from the polymer film was enhanced by addition of beta-CyD polymer to the vehicle. When lidocaine and ketoprofen was incubated with beta-CyD polymer in the artificial saliva, concentration of free lidocaine molecules decreased in a beta-CyD polymer concentration-dependent manner. The association constant with beta-CyD polymer was 6.9+/-0.6 and 520+/-90 M(-1) for lidocaine and ketoprofen, respectively. Retarded release of the hydrophilic lidocaine by beta-CyD polymer might be due to the decrease in thermodynamic activity by inclusion complex formation, whereas enhanced release of the lipophilic ketoprofen by the beta-CyD polymer might be due to prevention of recrystallization occurring after contacting the film with aqueous solution. Thus, effects of low-molecular-weight beta-CyD polymer to the drug release rate from film dosage forms would vary according to the strength of interaction with and the solubility of active ingredient.

  19. Effects of radioactive hot particles on pig skin

    Energy Technology Data Exchange (ETDEWEB)

    Kaurin, D.G.; Baum, J.W.; Schaefer, C.W. [and others

    1997-06-01

    The purpose of these studies was to determine the incidence and severity of lesions resulting from very localized deposition of dose to skin from small (< 0.5 mm) discrete radioactive particles as produced in the work environments of nuclear reactors. Hanford mini-pigs were exposed, both on a slightly off the skin, to localized replicate doses from 0.31 to 64 Gy (averaged over 1 cm{sup 2} at 70 {mu}m depth unless noted otherwise) using Sc-46, Yb-175, Tm-170, and fissioned UC{sub 2} isotopes having maximum beta-particle energies from about 0.3 to 3 MeV. Erythema and scabs (indicating ulceration) were scored for up to 71 days post-irradiation. The responses followed normal cumulative probability distributions, and therefore, no true threshold could be defined. Hence, 10 and 50% scab incidence rates were deduced using probit analyses. The lowest dose which produced 10% incidence was about 1 Gy for Yb-175 (0.5 MeV maximum energy) beta particle exposures, and about 3 to 9 Gy for other isotopes. The histopathology of lesions was determined at several doses. Single exposures to doses as large as 1,790 Gy were also given, and results were observed for up to 144 days post-exposure. Severity of detriment was estimated by analyzing the results in terms of lesion diameter, persistence, and infection. Over 1,100 sites were exposed. Only two exposed sites became infected after doses near 5000 Gy; the lesions healed quickly on treatment. 105 refs., 145 figs., 47 tabs.

  20. Effect of ventilation pressure on alveolar fluid clearance and beta-agonist responses in mice.

    Science.gov (United States)

    Yu, Erin N Z; Traylor, Zachary P; Davis, Ian C

    2009-10-01

    High tidal volume ventilation is detrimental to alveolar fluid clearance (AFC), but effects of ventilation pressure (P) on AFC are unknown. In anesthetized BALB/c mice ventilated at constant tidal volume (8 ml/kg), mean AFC rate was 12.8% at 6 cmH(2)O P, but increased to 37.3% at 18 cmH(2)O P. AFC rate declined at 22 cmH(2)O P, which also induced lung damage. Increased AFC at 18 cmH(2)O P did not result from elevated plasma catecholamines, hypercapnia, or hypocapnia, but was due to augmented Na(+) and Cl(-) absorption. PKA agonists and beta-agonists stimulated AFC at 10 cmH(2)O P by upregulating amiloride-sensitive Na(+) transport. However, at 18 cmH(2)O P, PKA agonists and beta-agonists reduced AFC. At 15 cmH(2)O P, the AFC rate was intermediate (mean 26.6%), and forskolin and beta-agonists had no effect. Comparable P dependency of AFC and beta-agonist responsiveness was found in C57BL/6 mice. The effect on AFC of increasing P to 18 cmH(2)O was blocked by adenosine deaminase or an A(2b)-adenosine receptor antagonist, and could be mimicked by adenosine in mice ventilated at 10 cmH(2)O P. Modulation of adenosine signaling also resulted in altered responsiveness to beta-agonists. These findings indicate that, in the normal mouse lung, basal AFC rates and responses to beta-agonists are impacted by ventilation pressure in an adenosine-dependent manner.

  1. Stereoselective and nonstereoselective effects of ibuprofen enantiomers on mitochondrial beta-oxidation of fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Freneaux, E.; Fromenty, B.; Berson, A.; Labbe, G.; Degott, C.; Letteron, P.; Larrey, D.; Pessayre, D. (Unite de Recherches de Physiolopathologie Hepatique (INSERM U-24), Hopital Beaujon, Clichy (France))

    1990-11-01

    The effects of the R-(-) and S-(+)ibuprofen enantiomers were first studied in vitro with mouse liver mitochondria incubated in the presence of various concentrations of exogenous coenzyme A. In the presence of a low concentration of coenzyme A (2.5 microM), the R-(-)enantiomer (which forms an acylcoenzyme A) inhibited stereoselectively the beta oxidation of (1-{sup 14}C)palmitic acid but not that of (1-{sup 14}C)palmitoyl-L-carnitine (which can directly enter the mitochondria). In the presence, however, of a concentration of coenzyme A (50 microM) reproducing that present in liver cell cytosol, both enantiomers (2 mM) slightly inhibited the beta oxidation of (1-{sup 14}C)palmitic acid and markedly inhibited the beta oxidation of (1-{sup 14}C)octanoic acid and (1-{sup 14}C)butyric acid. In vivo, both enantiomers (1 mmol.kg-1) similarly inhibited the formation of ({sup 14}C)CO{sub 2} from (1-{sup 14}C)fatty acids. Both enantiomers similarly decreased plasma ketone bodies. Both similarly increased hepatic triglycerides, and both produced mild microvesicular steatosis of the liver. We conclude that both ibuprofen enantiomers inhibit beta oxidation of fatty acids in vitro and in vivo. In addition, the R-(-)enantiomer may stereoselectively sequester coenzyme A; at low concentrations of coenzyme A in vitro, this may stereoselectively inhibit the mitochondrial uptake and beta oxidation of long chain fatty acids.

  2. Effect of beta-lactoglobulin polymorphism and seasonality on bovine milk composition.

    Science.gov (United States)

    Botaro, Bruno G; Lima, Ygor V R; Aquino, Adriana A; Fernandes, Raquel H R; Garcia, José F; Santos, Marcos V

    2008-05-01

    The objective was to evaluate the effect of beta-lactoglobulin (beta-lg) polymorphism and seasonality on milk composition (fat, lactose, total solids, milk urea nitrogen, total protein, true protein, casein and somatic cell counts) of Holstein and Girolando cows. Milk and blood samples from 278 Holsteins cows and 156 Girolando cows were taken during two dry seasons and two rainy seasons, for milk composition analysis and to determine beta-lg genotypes, respectively. BB genotype was the most frequent for both breeds, followed by AA genotype for Holstein (BB>AA>AB) and by AB for Girolando cows (BB>AB>AA). No differences were found in milk compositional characteristics among genetic variants of beta-lg (AA, AB and BB) either between Holstein or Girolando cows. No association between milk composition and beta-lg genetic polymorphism was observed. During the dry season, independently of the breed considered, higher contents of lactose, true protein, casein and casein:true protein ratio were found.

  3. Stereoselective and nonstereoselective effects of ibuprofen enantiomers on mitochondrial beta-oxidation of fatty acids

    International Nuclear Information System (INIS)

    Freneaux, E.; Fromenty, B.; Berson, A.; Labbe, G.; Degott, C.; Letteron, P.; Larrey, D.; Pessayre, D.

    1990-01-01

    The effects of the R-(-) and S-(+)ibuprofen enantiomers were first studied in vitro with mouse liver mitochondria incubated in the presence of various concentrations of exogenous coenzyme A. In the presence of a low concentration of coenzyme A (2.5 microM), the R-(-)enantiomer (which forms an acylcoenzyme A) inhibited stereoselectively the beta oxidation of [1- 14 C]palmitic acid but not that of [1- 14 C]palmitoyl-L-carnitine (which can directly enter the mitochondria). In the presence, however, of a concentration of coenzyme A (50 microM) reproducing that present in liver cell cytosol, both enantiomers (2 mM) slightly inhibited the beta oxidation of [1- 14 C]palmitic acid and markedly inhibited the beta oxidation of [1- 14 C]octanoic acid and [1- 14 C]butyric acid. In vivo, both enantiomers (1 mmol.kg-1) similarly inhibited the formation of [ 14 C]CO 2 from [1- 14 C]fatty acids. Both enantiomers similarly decreased plasma ketone bodies. Both similarly increased hepatic triglycerides, and both produced mild microvesicular steatosis of the liver. We conclude that both ibuprofen enantiomers inhibit beta oxidation of fatty acids in vitro and in vivo. In addition, the R-(-)enantiomer may stereoselectively sequester coenzyme A; at low concentrations of coenzyme A in vitro, this may stereoselectively inhibit the mitochondrial uptake and beta oxidation of long chain fatty acids

  4. The quantum brownian particle and memory effects

    International Nuclear Information System (INIS)

    Britani, J.R.; Mizrahi, S.S.; Pimentel, B.M.

    1991-01-01

    The Quantum Brownian particle, immersed in a heat bath, is described by a statistical operator whose evolution is ruled by a Generalized Master Equation (GME). The heat bath degrees of freedom are considered to be either white noise or coloured noise correlated,while the GME is considered under either the Markov or Non-Markov approaches. The comparison between these considerations are fully developed and their physical meaning is discussed. (author)

  5. Shortwave radiative effects of unactivated aerosol particles in clouds

    International Nuclear Information System (INIS)

    Ackerman, T.; Baker, M.B.

    1977-01-01

    Clouds in some polluted areas may contain high concentrations of anthropogenic aerosol particles. The possible role of these particles in perturbing the optical and dynamical properties of the clouds is an important question for climate studies. The direct radiative effects of unactivated aerosol particles in stable stratus clouds have been calculated at lambda=0.5μm. Several simplifying asumptions have been made relating the behavior of such particles in the high humidity enviornment within the cloud to their physicochemical make-up. It is shown that the energy absorbed by particles within the clouds may be, for realistic concentrations, comparable to the latent heat released and thus may play a significant role in cloud dynamics in some areas. These results are shown to be relatively insensitive to the assumptions about the particle properties within the cloud

  6. Effects of beta-blockers and nicardipine on oxotremorine-induced tremor in common marmosets.

    Science.gov (United States)

    Mitsuda, M; Nomoto, M; Iwata, S

    1999-10-01

    Effects of beta-blockers (propranolol, arotinolol and nipradilol) and a Ca2+ channel blocker (nicardipine) on oxotremorine-induced tremor were studied in common marmosets. Generalized tremor was elicited by an intraperitoneal administration of 0.25 mg/kg oxotremorine. Intensity of the tremor was classified into 7 degrees, and it was evaluated every 10 min. The total intensity of oxotremorine-induced tremor for each drug was expressed as "points", which were the sum of tremor intensity scores evaluated every 10 min up to 190 min following the administration of oxotremorine. Beta-blockers significantly suppressed the tremor. On the other hand, the Ca2+ channel blocker exacerbated the tremor.

  7. Effect of limestone particle size on bone quality characteristics of ...

    African Journals Online (AJOL)

    A study was conducted to determine the effect of different limestone particle sizes in layer diets on bone quality characteristics at end-of-lay hens. Calcitic limestone (360 g Ca/kg DM) that is extensively used in commercial poultry diets was obtained from a specific South African source. Limestone particles were graded as ...

  8. Effect of limestone particle size on egg production and eggshell ...

    African Journals Online (AJOL)

    Different limestone particle sizes had no effect on any of the tested egg production and eggshell quality parameters. These results suggested that larger particles limestone are not necessarily essential to provide sufficient Ca2+ to laying hens for egg production and eggshell quality at end-of-lay, provided that the dietary Ca ...

  9. Beta particle detection efficiency of the radiation sensor made from a mixture of polyaniline and titanium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, M., E-mail: tamuram@hep.sc.niigata-u.ac.jp [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Carlit Holdings Co., Ltd., Tokyo 104-0031 (Japan); Miyata, H., E-mail: miyata@hep.sc.niigata-u.ac.jp [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Department of Physics, Niigata University, Niigata 950-2181 (Japan); Katsumata, M. [Department of Physics, Niigata University, Niigata 950-2181 (Japan); Matsuda, K.; Ueno, T.; Ito, D. [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan); Suzuki, T. [Carlit Holdings Co., Ltd., Tokyo 104-0031 (Japan)

    2016-08-21

    We developed a new real-time radiation sensor using an organic semiconductor and measured its β-particle detection sensitivity. This sensor is fabricated by simply combining a p-type semiconductor, polyaniline (Pani), with an n-type semiconductor, TiO{sub 2}, and processing the compound. Since Pani and TiO{sub 2} are both inexpensive materials, the sensor can be fabricated at a lower cost than inorganic semiconductor sensors. The signal of each fabricated sensor was measured by a charge sensitive ADC for the irradiation of β-particles. The response signal data of the ADC for each irradiation was measured to calculate the detection efficiency of the detector. The maximum detection efficiency measured as β-particle sensitivity of the sensor was 1%. This β-particle sensitivity is higher than that reported of Pani sensors in the past.

  10. Effects of ethanol on pancreatic beta-cell death: interaction with glucose and fatty acids.

    Science.gov (United States)

    Dembele, Korami; Nguyen, K Hoa; Hernandez, Tiffany A; Nyomba, B L Grégoire

    2009-04-01

    Western lifestyle plays an important role in the prevalence of type 2 diabetes by causing insulin resistance and pancreatic beta-cell dysfunction, a prerequisite for the development of diabetes. High fat diet and alcohol are major components of the western diet. The aim of the present study was to investigate the effects of ethanol and fatty acids on beta-cell survival and metabolism. We treated the rat beta-cell line RINm5F with ethanol, a mixture of palmitic and oleic acids, or both. Reactive oxygen species (ROS) were determined by (5-(and-6)-chloromethyl-2',7'-dichlorodihydrofluorescein diacetate) (CM-H2DCFDA) fluorescence assay, and mitochondrial activity was assessed by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) reduction assay and by determining ATP production. Cell viability was assessed with a cell counter and trypan blue exclusion, and the mode of cell death by Hoechst33342 and propidium iodide staining. With both ethanol and fatty acid treatments, MTT reduction and ATP production decreased, whereas ROS production increased. Ethanol treatment had no effect on cell number, whereas fatty acid treatment reduced the cell number. Cell incubation with ethanol, fatty acids, or both increased the number of Hoechst 33342-positive nuclei. However, the majority of nuclei from fatty acid-treated cells were stained with propidium iodide, indicating a loss of plasma membrane integrity. We conclude that both ethanol and fatty acids generate cellular oxidative stress, and affect mitochondrial function in RINm5F beta-cells. However, ethanol causes beta-cell death by apoptosis, whereas fatty acids cause cell death predominantly by necrosis. It is not known whether these results are applicable to human beta-cells.

  11. The effect of suppressor of cytokine signaling 3 on GH signaling in beta-cells

    DEFF Research Database (Denmark)

    Rønn, Sif G; Hansen, Johnny A; Lindberg, Karen

    2002-01-01

    GH is an important regulator of cell growth and metabolism. In the pancreas, GH stimulates mitogenesis as well as insulin production in beta-cells. The cellular effects of GH are exerted mainly through activation of the Janus kinase-signal transducer and activator of transcription (STAT) pathway...

  12. Effect of the gamma radiation of cobalt 60 on the beta carotids present in the carrot

    International Nuclear Information System (INIS)

    Perez Lopez, Sergio Victor Hugo

    1997-01-01

    In the present work it was investigated the effect of the gamma radiation of cobalt 60 on the beta carotid's in the carrot (daucus carota), using for it three different radiation dose (100, 150 and 200 kilo-rad) and analyzing them by means of the liquid chromatography technique of high resolution (HPLC)

  13. Spare receptors for beta-adrenoceptor-mediated positive inotropic effects of catecholamines in the human heart

    NARCIS (Netherlands)

    Brown, L.; Deighton, N. M.; Bals, S.; Söhlmann, W.; Zerkowski, H. R.; Michel, M. C.; Brodde, O. E.

    1992-01-01

    We studied whether the human heart has spare receptors for beta-adrenoceptor-mediated positive inotropic effects. Thus, we assessed in right atria and left papillary muscles of patients with different degrees of heart failure under identical experimental conditions affinity (pKI values from

  14. The effect of backscattering on the beta dose absorbed by individual quartz grains

    DEFF Research Database (Denmark)

    Autzen, Martin; Guérin, G.; Murray, A. S.

    2017-01-01

    We describe the effect on dose rates and over-dispersion (OD) of changing the spectrum of energies to which grains of various shapes and volumes are exposed during beta irradiation, either by changing the backscattering medium or attenuating the incident spectrum. Dose rates are found to increase...

  15. Effects of putrescine, cadaverine, spermine, spermidine and beta-phenylethylamine on cultured bovine mammary epithelial cells

    DEFF Research Database (Denmark)

    Fusi, Eleonora; Baldi, Antonella; Cheli, Federica

    2008-01-01

    A bovine mammary epithelial cell line (BME-UV1) and three-dimensional collagen primary bovine organoids were used to evaluate the effects of cadaverine, putrescine, spermine, spermicline and beta-phenylethylamine on mammary epithelial cells. Each biogenic amine was diluted in several concentratio...

  16. Effect of iron on pancreatic beta cell function and insulin resistance ...

    African Journals Online (AJOL)

    Background: Increase in total body iron store has been reported in the aetiology and development of diabetes mellitus. The effect of iron supplementation in female with respect to the incidence of diabetes mellitus was investigated on the pancreatic beta cell function and insulin resistance in normal female rats. Methods: ...

  17. Effect of Soybean Sprouting and Beta-Glucanase Treatment of Wet ...

    African Journals Online (AJOL)

    Effect of Soybean Sprouting and Beta-Glucanase Treatment of Wet Milled Soybean on the Chemical Properties of Soymilk from Different Varieties of Soybean. ... Sugars were also qualitatively and quantitatively analyzed with thin layer chromatography and spectrophotometry respectively. Proximate composition and dietary ...

  18. A chemically stable analogue, 9 beta-methyl carbacyclin, with similar effects to epoprostenol (prostacyclin, PGI2) in man.

    OpenAIRE

    O'Grady, J; Hedges, A; Whittle, B J; Al-Sinawi, L A; Mekki, Q A; Burke, C; Moody, S G; Moti, M J; Hassan, S

    1984-01-01

    The effects of 9 beta-methyl carbacyclin, a chemically stable analogue of epoprostenol (prostacyclin, PGI2) were studied, in comparison with epoprostenol, both in vitro and in vivo in man. In vitro 9 beta-methyl carbacyclin and epoprostenol inhibited platelet aggregation induced by ADP, collagen, the endoperoxide analogue U46619 and arachidonic acid. The potency of 9 beta-methyl carbacyclin relative to epoprostenol was comparable in ADP and collagen-aggregated platelet rich plasma (PRP), 9 be...

  19. The effects of beta acids from hops (Humulus lupulus L.)on mortality of Varroa destructor (Acari: Varroidae)

    Science.gov (United States)

    Beta acids from hop plants (Humulus lupulus L.) reduce feeding and oviposition behaviors and increase mortality in certain phytophagous mites. These compounds were tested for their effects on Varroa destructor (Anderson and Trueman) mortality. The effects of hops beta acids (HBA) on honey bee (Apis ...

  20. Hexagon POPE: effective particles and tree level resummation

    Energy Technology Data Exchange (ETDEWEB)

    Córdova, Lucía [Perimeter Institute for Theoretical Physics,Waterloo, Ontario N2L 2Y5 (Canada); Department of Physics and Astronomy & Guelph-Waterloo Physics Institute,University of Waterloo,Waterloo, Ontario N2L 3G1 (Canada)

    2017-01-12

    We present the resummation of the full Pentagon Operator Product Expansion series of the hexagon Wilson loop in planar N=4 SYM at tree level. We do so by considering the one effective particle states formed by a fundamental flux tube excitation and an arbitrary number of the so called small fermions which are then integrated out. We derive the one effective particle measures at finite coupling. By evaluating these measures at tree level and summing over all one effective particle states we reproduce the full 6 point tree level amplitude.

  1. Interferons beta have vasoconstrictive and procoagulant effects: a woman who developed livedo reticularis and Raynaud phenomenon in association with interferon beta treatment for multiple sclerosis.

    Science.gov (United States)

    Rot, Uroš; Ledinek, Alenka Horvat

    2013-12-01

    A 31-year-old woman with MS developed livedo reticularis and secondary Raynaud phenomenon 2.5 years after introduction of interferon beta-1b. The symptoms disappeared after withdrawal of the drug. Livedo reticularis and Raynaud phenomenon as well as pulmonary arterial hypertension, venous sinus thrombosis, pulmonary embolism and renal thrombotic microangiopathy have all been described in association with interferon beta therapy. These complications strongly suggest that type I interferons have vasoconstrictive and procoagulant effects with potentially serious systemic complications. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Stimulated-emission effects in particle creation near black holes

    Energy Technology Data Exchange (ETDEWEB)

    Wald, R.M.

    1976-06-15

    It has recently been shown that if a black hole is formed by gravitational collapse, spontaneous particle creation will occur and a thermal spectrum of all species of particles will be emitted to infinity if the quantum matter was initially in the vacuum state. In this paper we investigate the stimulated-emission effects which occur if particles are present initially. We show in general that for a Hermitian scalar field in an external potential or in curved, asymptotically flat spacetime, stimulated-emission effects can occur precisely in those modes for which there is spontaneous particle creation from the vacuum. For the case of a Schwarzschild black hole, this result appears paradoxical, since spontaneous emission occurs at late times but there is no classical analog of stimulated emission at late times. The resolution of this paradox is that in order to induce emission of particles which emerge at late times one must send in particles at early times, so that they reach the black hole very near the instant of its formation. However, enormous energy is required of these incoming particles in order to stimulate emission of particles which emerge at late times. Thus, for a Schwarzschild black hole, even if particles are initially present (with limited energy) they will induce emission only at early times; at late times one will see only the spontaneously emitted blackbody thermal radiation. For the case of a Kerr black hole stimulated emission can be induced by particles sent in at late times with the appropriate frequencies and angular dependence. If the number of incoming particles is large, this quantum stimulated emission just gives the classical superradiant scattering. (AIP)

  3. Stimulated-emission effects in particle creation near black holes

    International Nuclear Information System (INIS)

    Wald, R.M.

    1976-01-01

    It has recently been shown that if a black hole is formed by gravitational collapse, spontaneous particle creation will occur and a thermal spectrum of all species of particles will be emitted to infinity if the quantum matter was initially in the vacuum state. In this paper we investigate the stimulated-emission effects which occur if particles are present initially. We show in general that for a Hermitian scalar field in an external potential or in curved, asymptotically flat spacetime, stimulated-emission effects can occur precisely in those modes for which there is spontaneous particle creation from the vacuum. For the case of a Schwarzschild black hole, this result appears paradoxical, since spontaneous emission occurs at late times but there is no classical analog of stimulated emission at late times. The resolution of this paradox is that in order to induce emission of particles which emerge at late times one must send in particles at early times, so that they reach the black hole very near the instant of its formation. However, enormous energy is required of these incoming particles in order to stimulate emission of particles which emerge at late times. Thus, for a Schwarzschild black hole, even if particles are initially present (with limited energy) they will induce emission only at early times; at late times one will see only the spontaneously emitted blackbody thermal radiation. For the case of a Kerr black hole stimulated emission can be induced by particles sent in at late times with the appropriate frequencies and angular dependence. If the number of incoming particles is large, this quantum stimulated emission just gives the classical superradiant scattering

  4. Lack of effect of chronic calcium antagonist treatment on beta 1- and beta 2-adrenoceptors in right atria from patients with or without heart failure

    NARCIS (Netherlands)

    Brodde, O. E.; Hundhausen, H. J.; Zerkowski, H. R.; Michel, M. C.

    1992-01-01

    1. We studied the effects of chronic calcium antagonist (calcium entry blocker, CEB; nifedipine, verapamil, diltiazem) treatment on beta-adrenoceptor density (assessed by (-)-[125I]-iodocyanopindolol [ICYP] binding) and subtype distribution in right atria from 65 patients without apparent heart

  5. Mass transfer effects in hygroscopic measurements of aerosol particles

    Directory of Open Access Journals (Sweden)

    M. N. Chan

    2005-01-01

    Full Text Available The tandem differential mobility analyzer (TDMA has been widely utilized to measure the hygroscopicity of laboratory-generated and atmospheric submicrometer particles. An important concern in investigating the hygroscopicity of the particles is if the particles have attained equilibrium state in the measurements. We present a literature survey to investigate the mass transfer effects in hygroscopicity measurements. In most TDMA studies, a residence time in the order of seconds is used for humidification (or dehumidification. NaCl and (NH42SO4 particles are usually used to verify the equilibrium measurements during this residence time, which is presumed to be sufficient for other particles. There have been observations that not all types of submicrometer particles, including atmospheric particles, attain their equilibrium sizes within this time scale. We recommend that experimentation with different residence times be conducted and that the residence time should be explicitly stated in future TDMA measurements. Mass transfer effects may also exist in the measurements of other properties related to the water uptake of atmospheric particles such as relative humidity dependent light scattering coefficients and cloud condensation nuclei activity.

  6. Effect of Ionizing Beta Radiation on the Mechanical Properties of Poly(ethylene under Thermal Stress

    Directory of Open Access Journals (Sweden)

    Bednarik Martin

    2016-01-01

    Full Text Available It was found in this study, that ionizing beta radiation has a positive effect on the mechanical properties of poly(ethylene. In recent years, there have been increasing requirements for quality and cost effectiveness of manufactured products in all areas of industrial production. These requirements are best met with the polymeric materials, which have many advantages in comparison to traditional materials. The main advantages of polymer materials are especially in their ease of processability, availability, and price of the raw materials. Radiation crosslinking is one of the ways to give the conventional plastics mechanical, thermal, and chemical properties of expensive and highly resistant construction polymers. Several types of ionizing radiation are used for crosslinking of polymers. Each of them has special characteristics. Electron beta and photon gamma radiation are used the most frequently. The great advantage is that the crosslinking occurs after the manufacturing process at normal temperature and pressure. The main purpose of this paper has been to determine the effect of ionizing beta radiation on the tensile modulus, strength and elongation of low and high density polyethylene (LDPE and HDPE. These properties were examined in dependence on the dosage of the ionizing beta radiation (non-irradiated samples and those irradiated by dosage 99 kGy were compared and on the test temperature. Radiation cross-linking of LDPE and HDPE results in increased tensile strength and modulus, and decreased of elongation. The measured results indicate that ionizing beta radiation treatment is effective tool for improvement of mechanical properties of LDPE and HDPE under thermal stress.

  7. Power output and efficiency of beta-emitting microspheres

    International Nuclear Information System (INIS)

    Cheneler, David; Ward, Michael

    2015-01-01

    Current standard methods to calculate the dose of radiation emitted during medical applications by beta-minus emitting microspheres rely on an over-simplistic formalism. This formalism is a function of the average activity of the radioisotope used and the physiological dimensions of the patient only. It neglects the variation in energy of the emitted beta particle due to self-attenuation, or self-absorption, effects related to the finite size of the sphere. Here it is assumed the sphere is comprised of a pure radioisotope with beta particles being emitted isotropically throughout the material. The full initial possible kinetic energy distribution of a beta particle is taken into account as well as the energy losses due to scattering by other atoms in the microsphere and bremsstrahlung radiation. By combining Longmire’s theory of the mean forward range of charged particles and the Rayleigh distribution to take into account the statistical nature of scattering and energy straggling, the linear attenuation, or self-absorption, coefficient for beta-emitting radioisotopes has been deduced. By analogy with gamma radiation transport in spheres, this result was used to calculate the rate of energy emitted by a beta-emitting microsphere and its efficiency. Comparisons to standard point dose kernel formulations generated using Monte Carlo data show the efficacy of the proposed method. Yttrium-90 is used as a specific example throughout, as a medically significant radioisotope, frequently used in radiation therapy for treating cancer. - Highlights: • Range-energy relationship for the beta particles in yttrium-90 is calculated. • Formalism for the semi-analytical calculation of self-absorption coefficients. • Energy-dependent self-absorption coefficient calculated for yttrium-90. • Flux rate of beta particles from a self-attenuating radioactive sphere is shown. • The efficiency of beta particle emitting radioactive microspheres is calculated

  8. Effective field theory of thermal Casimir interactions between anisotropic particles.

    Science.gov (United States)

    Haussman, Robert C; Deserno, Markus

    2014-06-01

    We employ an effective field theory (EFT) approach to study thermal Casimir interactions between objects bound to a fluctuating fluid surface or interface dominated by surface tension, with a focus on the effects of particle anisotropy. The EFT prescription disentangles the constraints imposed by the particles' boundaries from the calculation of the interaction free energy by constructing an equivalent point particle description. The finite-size information is captured in a derivative expansion that encodes the particles' response to external fields. The coefficients of the expansion terms correspond to generalized tensorial polarizabilities and are found by matching the results of a linear response boundary value problem computed in both the full and effective theories. We demonstrate the versatility of the EFT approach by constructing the general effective Hamiltonian for a collection of particles of arbitrary shapes. Taking advantage of the conformal symmetry of the Hamiltonian, we discuss a straightforward conformal mapping procedure to systematically determine the polarizabilities and derive a complete description for elliptical particles. We compute the pairwise interaction energies to several orders for nonidentical ellipses as well as their leading-order triplet interactions and discuss the resulting preferred pair and multibody configurations. Furthermore, we elaborate on the complications that arise with pinned particle boundary conditions and show that the powerlike corrections expected from dimensional analysis are exponentially suppressed by the leading-order interaction energies.

  9. Biophysical evaluation of the radioprotective role of thiola and olive oil during the treatment of some eye lesions with beta particles

    International Nuclear Information System (INIS)

    Mahmoud, S.S.; Gamal, M.M.

    2003-01-01

    This study was conducted to evaluate the radioactive efficacy of topical application of the radioprotector thiola alone or when combined with olive oil on the biophysical characteristics of lens lipids. Two groups of New Zealand white rabbits were used in this study. The first group (thiola group) was topically applied with thiola thirty minutes and one minute before the treatment with two doses of beta particles (24Gy and 100 Gy). The second group (olive oil and thipla group) was also received thiola as in the first group then olive oil was topically applied after the irradiationand countinue daily till decapitation. The lens lipids were studied using UV-spectroscopy, fourier transform infrared spectroscopy and phase transition measurement. In additio, cholesterol and phospholipids concentrations were measured. The resulted typical absorption spectra of the lens lipids indicated that the native lipid peak was shifted towards higher wave length for both doses (24 Gy and 100 Gy) in both olive oil group and the thiola group. The results also indicated that there were fluctuated changes in lens stability and fluidity concomintant with conformational and compositional changes in both groups. It may be concluded from the present study that application of thiola alone or combined with olive oil seems to be promising tool in preventing the peroxidation of lens lipids induced by beta radiation tretments

  10. Effect of acute ethanol on beta-endorphin secretion from rat fetal hypothalamic neurons in primary cultures

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, D.K.; Minami, S. (Washington State Univ., Pullman (USA))

    1990-01-01

    To characterize the effect of ethanol on the hypothalamic {beta}-endorphin-containing neurons, rat fetal hypothalamic neurons were maintained in primary culture, and the secretion of {beta}-endorphin ({beta}-EP) was determined after ethanol challenges. Constant exposure to ethanol at doses of 6-50 mM produced a dose-dependent increase in basal secretion of {beta}-EP from these cultured cells. These doses of ethanol did not produce any significant effect on cell viability, DNA or protein content. The stimulated secretion of {beta}-EP following constant ethanol exposure is short-lasting. However, intermittent ethanol exposures maintained the ethanol stimulatory action on {beta}-EP secretion for a longer time. The magnitude of the {beta}-EP response to 50 mM ethanol is similar to that of the {beta}-EP response to 56 mM of potassium. Ethanol-stimulated {beta}-EP secretion required extracellular calcium and was blocked by a calcium channel blocker; a sodium channel blocker did not affect ethanol-stimulated secretion. These results suggest that the neuron culture system is a useful model for studying the cellular mechanisms involved in the ethanol-regulated hypothalamic opioid secretion.

  11. Effects of bacteria-produced human alpha, beta, and gamma interferons on in vitro immune functions.

    Science.gov (United States)

    Shalaby, M R; Weck, P K; Rinderknecht, E; Harkins, R N; Frane, J W; Ross, M J

    1984-04-01

    The effects of bacteria-produced human interferons (HuIFN) alpha, beta, and gamma on in vitro immune functions of human peripheral blood mononuclear cells (PBMC) were studied. Proliferative response to phytohemagglutinin was significantly inhibited by the addition of HuIFN-alpha 2 or HuIFN-beta at 10, 100, or 1000 U/ml. In contrast, HuIFN-gamma showed suppressive activities only when added at 1000 U/ml. HuIFN-alpha 2 or HuIFN-beta caused significant inhibition of human mixed-lymphocyte reaction (MLR) as measured by [3H]thymidine incorporation. Similar inhibition was caused by HuIFN-gamma when it was added only at very low concentrations (1 U/ml); 10, 100, or 1000 U/ml resulted in no or only a modest increase in MLR. All three interferons exhibited dose-related effects on PWM-induced immunoglobulin synthesis in cultures of PBMC. These data demonstrate that purified interferons produced by recombinant DNA technology can significantly alter in vitro immune functions and that HuIFN-gamma has properties which are different from those of HuIFN-alpha 2 or HuIFN-beta.

  12. Preequilibrium particles and mean-field effects from particle-particle correlations in heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Ardouin, D.; Basrak, Z.; Remaud, B.; Sebille, F. (Nantes Univ., 44 (France). Lab. de Physique Nucleaire); Schuck, P. (Grenoble-1 Univ., 38 (France). Inst. des Sciences Nucleaires); Peghaire, A.; Saint-Laurent, F.; Delagrange, H.; Doubre, H.; Gregoire, C.; Kyanowski, A.; Mittig, W.; Peter, J. (Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)); Viyogi, Y.P. (Variable Energy Cyclotron Centre, Calcutta (India) Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)); Quebert, J. (CEA Centre d' Etudes Nucleaires de Bordeaux-Gradignan, 33 - Gradignan (France)); Gelbke, C.K.; Lynch, W.G.; Maier, M.; Pochodzalla, J. (National Superconducting Cyclotron Lab., East Lansing, MI (USA)); Bizard, G.; Lefebvres, F.; Tamain, B. (Caen Univ., 14 (France). Lab. de Physique Corpusculaire)

    1990-08-06

    Preequilibrium two-particle correlation functions at large relative momenta are shown to contain persisting mean-field effects at intermediate energies. These findings stem from simultaneous experimental and theoretical studies (using the Landau-Vlasov equation) of the systems {sup 40}Ar+Au and Ar+Ti at E/A=60 MeV. In the theoretical study are also included experimental data at lower energy (E/A=25 MeV) from other groups. (orig.).

  13. Preequilibrium particles and mean-field effects from particle-particle correlations in heavy-ion collisions

    International Nuclear Information System (INIS)

    Ardouin, D.; Basrak, Z.; Remaud, B.; Sebille, F.; Viyogi, Y.P.; Quebert, J.; Gelbke, C.K.; Lynch, W.G.; Maier, M.; Pochodzalla, J.; Bizard, G.; Lefebvres, F.; Tamain, B.

    1990-01-01

    Preequilibrium two-particle correlation functions at large relative momenta are shown to contain persisting mean-field effects at intermediate energies. These findings stem from simultaneous experimental and theoretical studies (using the Landau-Vlasov equation) of the systems 40 Ar+Au and Ar+Ti at E/A=60 MeV. In the theoretical study are also included experimental data at lower energy (E/A=25 MeV) from other groups. (orig.)

  14. Use of isotope effects to characterize intermediates in mechanism-based inactivation of dopamine beta-monooxygenase by beta-chlorophenethylamine

    International Nuclear Information System (INIS)

    Bossard, M.J.; Klinman, J.P.

    1990-01-01

    A mechanism for beta-chlorophenethylamine inhibition of dopamine beta-monooxygenase has been postulated in which bound alpha-aminoacetophenone is generated followed by an intramolecular redox reaction to yield a ketone-derived radical cation as the inhibitory species. Based on the assumption that the ketone radical is the inhibitory intermediate, an analogous system was predicted and verified. In the present study, the role of alpha-aminoacetophenone as the proposed intermediate in the inactivation by beta-chlorophenethylamine was examined in greater detail. From the interdependence of tyramine and alpha-aminoacetophenone concentrations, ketone inactivation is concluded to occur at the substrate site as opposed to potential binding at the reductant-binding site. Using beta-[2-1H]- and beta-[2-2H]chlorophenethylamine, the magnitude of the deuterium isotope effect on inactivation under second-order conditions has been found to be identical to that observed under catalytic turnover, D(kappa inact/Ki) = D(kappa cat/Km) = 6-7. By contrast, the isotope effect on inactivation under conditions of substrate and oxygen saturation, D kappa inact = 2, is 3-fold smaller than that seen on catalytic turnover, D kappa cat = 6. This reduced isotope effect for inactivation is attributed to a normal isotope effect on substrate hydroxylation followed by an inverse isotope effect on the partitioning of the enol of alpha-aminoacetophenone between oxidation to a radical cation versus protonation to regenerate ketone. These findings are unusual in that two isotopically sensitive steps are present in the inactivation pathway whereas only one is observable in turnover

  15. Fluid rheological effects on particle migration in rectangular microchannels

    Science.gov (United States)

    Li, Di; Xuan, Xiangchun

    2017-11-01

    There has been an increasing interest in the use of viscoelastic solutions for particle focusing and separation in microfluidic devices. These passive manipulations arise from the flow induced elastic lift force that interacts with the inertial lift force for an enhanced control of particle motions. The rheological properties of the suspending fluid are supposed to have a significant impact on particle migration in microchannels. We present in this work an experimental investigation of the elastic and/or inertial focusing of polystyrene particles suspended in the flow of four types of fluids with varying rheological properties through a straight rectangular microchannel. Such a fundamental study is expected to provide useful data for fluid rheological effects on particle migration, which may be used to validate theoretical models. Clemson SEED Grant.

  16. .beta.-Polypropylene/wood flour composites: effects of specific .beta.-nucleation and coupling agent on mechanical behaviour

    Czech Academy of Sciences Publication Activity Database

    Kotek, Jiří; Kelnar, Ivan; Synková, Hana; Starý, Zdeněk; Baldrian, Josef

    2007-01-01

    Roč. 103, č. 1 (2007), s. 506-511 ISSN 0021-8995 R&D Projects: GA ČR GP106/02/P027 Institutional research plan: CEZ:AV0Z40500505 Keywords : .beta.-polypropylene * wood flour * mechanical behavior Subject RIV: JI - Composite Materials Impact factor: 1.008, year: 2007

  17. The effects of ketotifen on beta-adrenergic activity in asthmatics.

    Science.gov (United States)

    Gove, R I; Burge, P S; Stableforth, D E; Skinner, C

    1988-01-01

    In order to examine a possible mechanism of action of ketotifen in asthma, a double-blind study was undertaken to determine whether ketotifen showed any effects on the beta-adrenergic system in asthmatic patients. The effects of ketotifen 1 mg b.i.d. for one month on the changes in spirometry, plasma potassium and serum glucose nebulized salbutamol was compared with placebo. In addition the degree of inhibition caused by local salbutamol on the wheal volume due to intradermal prostaglandin E and bradykinin, was compared following ketotifen and placebo. Nebulized salbutamol produced consistent improvements in spirometry and changes in potassium and glucose levels. Local salbutamol significantly decreased the wheal volume induced by intradermal prostaglandin E and bradykinin. However, none of these salbutamol-induced effects were altered following ketotifen or placebo. Ketotifen, in the doses used, has no demonstrable effect on the beta-adrenergic system in asthmatic patients.

  18. Effects of 17 beta-estradiol on radiation transformation in vitro; inhibition of effects by protease inhibitors

    International Nuclear Information System (INIS)

    Kennedy, A.R.; Weichselbaum, R.R.

    1981-01-01

    We have investigated the effects of 17 beta-estradiol, given both alone and with X-irradiation, on the induction of malignant transformation in vitro. Treatment with 10(-6)M 17 beta-estradiol for 6 weeks, or 10(-5)M 17 beta-estradiol for only 5 days, induced malignant transformation in C3H 10T1/2 cells. Estradiol also acted as a cocarcinogen for X-ray induced transformation; the results indicate an additive effect when the cells were exposed to both agents together. The protease inhibitors antipain and leupeptin suppressed estradiol induced transformation as well as the additive effect observed for estradiol-radiation transformation

  19. Effects of 17 beta-estradiol on radiation transformation in vitro; inhibition of effects by protease inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, A.R.; Weichselbaum, R.R.

    1981-01-01

    We have investigated the effects of 17 beta-estradiol, given both alone and with X-irradiation, on the induction of malignant transformation in vitro. Treatment with 10(-6)M 17 beta-estradiol for 6 weeks, or 10(-5)M 17 beta-estradiol for only 5 days, induced malignant transformation in C3H 10T1/2 cells. Estradiol also acted as a cocarcinogen for X-ray induced transformation; the results indicate an additive effect when the cells were exposed to both agents together. The protease inhibitors antipain and leupeptin suppressed estradiol induced transformation as well as the additive effect observed for estradiol-radiation transformation.

  20. The effect of noise on beta-cell burst period

    DEFF Research Database (Denmark)

    Pedersen, Morten Gram; Sørensen, Mads Peter

    2006-01-01

    isolated and coupled cells has been suggested to be due to stochastic fluctuations of the plasma membrane ions channels, which are supposed to have a stronger effect on single cells than on cells situated in clusters (the channel sharing hypothesis). This effect of noise has previously been studied based...... system, but with a quantitative description of the effect of noise. This approach supports previous investigations of the channel sharing hypothesis....... on numerical simulations. We show here how the application of two recent methods allows an analytic treatment of the stochastic effects on the location of the saddle-node and homoclinic bifurcations, which determine the burst period. Thus, the stochastic system can be analyzed similarly to the deterministic...

  1. Effect of Ionizing Beta Radiation on the Mechanical Properties of Poly(ethylene) under Thermal Stress

    OpenAIRE

    Bednařík, Martin; Maňas, David; Maňas, Miroslav; Mizera, Aleš; Řezníček, Martin

    2016-01-01

    It was found in this study, that ionizing beta radiation has a positive effect on the mechanical properties of poly(ethylene). In recent years, there have been increasing requirements for quality and cost effectiveness of manufactured products in all areas of industrial production. These requirements are best met with the polymeric materials, which have many advantages in comparison to traditional materials. The main advantages of polymer materials are especially in their ease of processabili...

  2. Fabrication and characterization of new LiF: Eu{sup 3+} sintered phosphors exposed to beta particles

    Energy Technology Data Exchange (ETDEWEB)

    Garcia H, A.R.; Cruz V, C. [Depto. de Investigacion en Polimeros y Materiales de la Universidad de Sonora, A.P. 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R.; Barboza F, M. [Universidad de Sonora, A.P. 5-088, 83190 Hermosillo, Sonora (Mexico); Kitis, G. [Nuclear Physics Laboratory, Aristotle University of Thessaloniki, 54124 (Greece); Castano, V.M. [IFUNAM, A.P. 1-1010, 76000 Queretaro (Mexico)

    2006-07-01

    Pellet-shaped LiF:Eu{sup 3+} phosphors were synthesized by sintering. To improve their thermoluminescence characteristics, different growth conditions were used. Thermal annealing at 750 C during 5 h under air atmosphere provided the samples with highest sensitivity. Characteristic glow curves exhibit an absolute maximum centered at 203 C, and another less intense peak between 250 and 300 C. The first peak has a position very suitable for dosimetry applications. Beta irradiated samples displayed a thermoluminescence response that increases as the radiation dose increased in the 0.16 - 42.0 Gy range. A fast fading of less than 20 % occurs in the first 10 s after irradiation, followed by a remarkable stability at room temperature. Computerized glow curve deconvolution of experimental data obtained applying the McKeever method to resolve the individual peaks revealed that the glow curves fits to nine individual peaks. Activation energies were computed by using the initial rise method. (Author)

  3. PGC-1alpha and PGC-1beta have both similar and distinct effects on myofiber switching toward an oxidative phenotype

    DEFF Research Database (Denmark)

    Mortensen, Ole Hartvig; Frandsen, Lis; Schjerling, Peter

    2006-01-01

    Peroxisome proliferator-activated receptor-gamma coactivator-1alpha and -1beta (PGC-1alpha and PGC-1beta) were overexpressed by adenovirus-mediated gene transfer in cultures of primary rat skeletal muscle cells derived from neonatal myoblasts. Effects on muscle fiber type transition and metabolism...

  4. Small particles big effect? - Investigating ice nucleation abilities of soot particles

    Science.gov (United States)

    Mahrt, Fabian; David, Robert O.; Lohmann, Ulrike; Stopford, Chris; Wu, Zhijun; Kanji, Zamin A.

    2017-04-01

    Atmospheric soot particles are primary particles produced by incomplete combustion of biomass and/or fossil fuels. Thus soot mainly originates from anthropogenic emissions, stemming from combustion related processes in transport vehicles, industrial and residential uses. Such soot particles are generally complex mixtures of black carbon (BC) and organic matter (OM) (Bond et al., 2013; Petzold et al., 2013), depending on the sources and the interaction of the primary particles with other atmospheric matter and/or gases BC absorbs solar radiation having a warming effect on global climate. It can also act as a heterogeneous ice nucleating particle (INP) and thus impact cloud-radiation interactions, potentially cooling the climate (Lohmann, 2002). Previous studies, however, have shown conflicting results concerning the ice nucleation ability of soot, limiting the ability to predict its effects on Earth's radiation budget. Here we present a laboratory study where we systematically investigate the ice nucleation behavior of different soot particles. Commercial soot samples are used, including an amorphous, industrial carbon frequently used in coatings and coloring (FW 200, Orion Engineered Carbons) and a fullerene soot (572497 ALDRICH), e.g. used as catalyst. In addition, we use soot generated from a propane flame Combustion Aerosol Standard Generator (miniCAST, JING AG), as a proxy for atmospheric soot particles. The ice nucleation ability of these soot types is tested on size-selected particles for a wide temperature range from 253 K to 218 K, using the Horizontal Ice Nucleation Chamber (HINC), a Continuous Flow Diffusion Chamber (CFDC) (Kanji and Abbatt, 2009). Ice nucleation results from these soot surrogates will be compared to chemically more complex real world samples, collected on filters. Filters will be collected during the 2016/2017 winter haze periods in Beijing, China and represent atmospheric soot particles with sources from both industrial and residential

  5. Charged-particle mutagenesis II. Mutagenic effects of high energy charged particles in normal human fibroblasts

    Science.gov (United States)

    Chen, D. J.; Tsuboi, K.; Nguyen, T.; Yang, T. C.

    1994-10-01

    The biological effects of high LET charged particles are a subject of great concern with regard to the prediction of radiation risk in space. In this report, mutagenic effects of high LET charged particles are quantitatively measured using primary cultures of human skin fibroblasts, and the spectrum of induced mutations are analyzed. The LET of the charged particles ranged from 25 KeV/μm to 975 KeV/gmm with particle energy (on the cells) between 94 - 603 MeV/u. The X-chromosome linked hypoxanthine guanine phosphoribosyl transferase (hprt) locus was used as the target gene. Exposure to these high LET charged particles resulted in exponential survival curves; whereas, mutation induction was fitted by a linear model. The Relative Biological Effect (RBE) for cell-killing ranged from 3.73 to 1.25, while that for mutant induction ranged from 5.74 to 0.48. Maximum RBE values were obtained at the LET of 150 keV/μm. The inactivation cross-section (αi) and the action-section for mutant induction (αm) ranged from 2.2 to 92.0 μm2 and 0.09 to 5.56 × 10-3 μm2, respectively. The maximum values were obtained by 56Fe with an LET of 200 keV/μm. The mutagenicity (αm/αi) ranged from 2.05 to 7.99 × 10-5 with the maximum value at 150 keV/μm. Furthermore, molecular analysis of mutants induced by charged particles indicates that higher LET beams are more likely to cause larger deletions in the hprt locus.

  6. Effective particle size from molecular dynamics simulations in fluids

    Science.gov (United States)

    Ju, Jianwei; Welch, Paul M.; Rasmussen, Kim Ø.; Redondo, Antonio; Vorobieff, Peter; Kober, Edward M.

    2018-04-01

    We report molecular dynamics simulations designed to investigate the effective size of colloidal particles suspended in a fluid in the vicinity of a rigid wall where all interactions are defined by smooth atomic potential functions. These simulations are used to assess how the behavior of this system at the atomistic length scale compares to continuum mechanics models. In order to determine the effective size of the particles, we calculate the solvent forces on spherical particles of different radii as a function of different positions near and overlapping with the atomistically defined wall and compare them to continuum models. This procedure also then determines the effective position of the wall. Our analysis is based solely on forces that the particles sense, ensuring self-consistency of the method. The simulations were carried out using both Weeks-Chandler-Andersen and modified Lennard-Jones (LJ) potentials to identify the different contributions of simple repulsion and van der Waals attractive forces. Upon correction for behavior arising the discreteness of the atomic system, the underlying continuum physics analysis appeared to be correct down to much less than the particle radius. For both particle types, the effective radius was found to be ˜ 0.75σ , where σ defines the length scale of the force interaction (the LJ diameter). The effective "hydrodynamic" radii determined by this means are distinct from commonly assumed values of 0.5σ and 1.0σ , but agree with a value developed from the atomistic analysis of the viscosity of such systems.

  7. Effective particle size from molecular dynamics simulations in fluids

    Science.gov (United States)

    Ju, Jianwei; Welch, Paul M.; Rasmussen, Kim Ø.; Redondo, Antonio; Vorobieff, Peter; Kober, Edward M.

    2017-12-01

    We report molecular dynamics simulations designed to investigate the effective size of colloidal particles suspended in a fluid in the vicinity of a rigid wall where all interactions are defined by smooth atomic potential functions. These simulations are used to assess how the behavior of this system at the atomistic length scale compares to continuum mechanics models. In order to determine the effective size of the particles, we calculate the solvent forces on spherical particles of different radii as a function of different positions near and overlapping with the atomistically defined wall and compare them to continuum models. This procedure also then determines the effective position of the wall. Our analysis is based solely on forces that the particles sense, ensuring self-consistency of the method. The simulations were carried out using both Weeks-Chandler-Andersen and modified Lennard-Jones (LJ) potentials to identify the different contributions of simple repulsion and van der Waals attractive forces. Upon correction for behavior arising the discreteness of the atomic system, the underlying continuum physics analysis appeared to be correct down to much less than the particle radius. For both particle types, the effective radius was found to be ˜ 0.75σ , where σ defines the length scale of the force interaction (the LJ diameter). The effective "hydrodynamic" radii determined by this means are distinct from commonly assumed values of 0.5σ and 1.0σ , but agree with a value developed from the atomistic analysis of the viscosity of such systems.

  8. Effects of transforming growth factor-beta1 and vascular endothelial growth factor 165 gene transfer on Achilles tendon healing.

    Science.gov (United States)

    Hou, Yu; Mao, ZeBin; Wei, XueLei; Lin, Lin; Chen, LianXu; Wang, HaiJun; Fu, Xin; Zhang, JiYing; Yu, Changlong

    2009-07-01

    Repaired Achilles tendons typically take weeks before they are strong enough to handle physiological loads. Gene therapy is a promising treatment for Achilles tendon defects. The aim of the present study was to evaluate the histological/biomechanical effects of Transforming growth factor-beta1 (TGF-beta1) and vascular endothelial growth factor 165 (VEGF(165)) gene transfer on Achilles tendon healing in rabbits. Bone Marrow-Derived Mesenchymal Stem Cells (BMSCs) were transduced with adenovirus carrying human TGF-beta1 cDNA (Ad-TGF-beta1), human VEGF(165) cDNA (Ad-VEGF(165)), or both (PIRES-TGF-beta1/VEGF(165)) Viruses, no cDNA (Ad-GFP), and the BMSCs without gene transfer and the intact tendon were used as control. BMSCs were surgically implanted into the experimentally injured Achilles tendons. TGF-beta1 distribution, cellularity, nuclear aspect ratio, nuclear orientation angle, vascular number, collagen synthesis, and biomechanical features were measured at 1, 2, 4, and 8 weeks after surgery. The TGF-beta1 and TGF beta 1/VEGF(165) co-expression groups exhibited improved parameters compared with other groups, while the VEGF(165) expression group had a negative impact. In the co-expression group, the angiogenesis effects of VEGF(165) were diminished by TGF-beta1, while the collagen synthesis effects of TGF-beta1 were unaltered by VEGF(165). Thus treatment with TGF-beta1 cDNA-transduced BMSCs grafts is a promising therapy for acceleration and improvement of tendon healing, leading to quicker recovery and improved biomechanical properties of Achilles tendons.

  9. Hypoglycemic and beta cell protective effects of andrographolide analogue for diabetes treatment

    Directory of Open Access Journals (Sweden)

    Larrick James W

    2009-07-01

    Full Text Available Abstract Background While all anti-diabetic agents can decrease blood glucose level directly or indirectly, few are able to protect and preserve both pancreatic beta cell mass and their insulin-secreting functions. Thus, there is an urgent need to find an agent or combination of agents that can lower blood glucose and preserve pancreatic beta cells at the same time. Herein, we report a dual-functional andrographolide-lipoic acid conjugate (AL-1. The anti-diabetic and beta cell protective activities of this novel andrographolide-lipoic acid conjugate were investigated. Methods In alloxan-treated mice (a model of type 1 diabetes, drugs were administered orally once daily for 6 days post-alloxan treatment. Fasting blood glucose and serum insulin were determined. Pathologic and immunohistochemical analysis of pancreatic islets were performed. Translocation of glucose transporter subtype 4 in soleus muscle was detected by western blot. In RIN-m cells in vitro, the effect of AL-1 on H2O2-induced damage and reactive oxidative species production stimulated by high glucose and glibenclamide were measured. Inhibition of nuclear factor kappa B (NF-κB activation induced by IL-1β and IFN-γ was investigated. Results In alloxan-induced diabetic mouse model, AL-1 lowered blood glucose, increased insulin and prevented loss of beta cells and their dysfunction, stimulated glucose transport protein subtype 4 (GLUT4 membrane translocation in soleus muscles. Pretreatment of RIN-m cells with AL-1 prevented H2O2-induced cellular damage, quenched glucose and glibenclamide-stimulated reactive oxidative species production, and inhibited cytokine-stimulated NF-κB activation. Conclusion We have demonstrated that AL-1 had both hypoglycemic and beta cell protective effects which translated into antioxidant and NF-κB inhibitory activity. AL-1 is a potential new anti-diabetic agent.

  10. Beta(2) adrenergic receptors mediate important electrophysiological effects in human ventricular myocardium.

    Science.gov (United States)

    Lowe, M D; Rowland, E; Brown, M J; Grace, A A

    2001-07-01

    To define the effects of beta(2) adrenergic receptor stimulation on ventricular repolarisation in vivo. Prospective study. Tertiary referral centre. 85 patients with coronary artery disease and 22 normal controls. Intravenous and intracoronary salbutamol (a beta(2) adrenergic receptor selective agonist; 10-30 microg/min and 1-10 microg/min), and intravenous isoprenaline (a mixed beta(1)/beta(2) adrenergic receptor agonist; 1-5 microg/min), infused during fixed atrial pacing. QT intervals, QT dispersion, monophasic action potential duration. In patients with coronary artery disease, salbutamol decreased QT(onset) and QT(peak) but increased QT(end) duration; QT(onset)-QT(peak) and QT(peak)-QT(end) intervals increased, resulting in T wave prolongation (mean (SEM): 201 (2) ms to 233 (2) ms; p salbutamol (controls), and 70 (1) ms baseline v 108 (3) ms salbutamol (coronary artery disease); p action potential duration at 90% repolarisation shortened during intracoronary infusion of salbutamol, from 278 (4.1) ms to 257 (3.8) ms (p mechanism whereby catecholamines acting through this receptor subtype may trigger ventricular arrhythmias.

  11. Dual aminergic regulation of central beta adrenoceptors. Effect of atypical antidepressants and 5-hydroxytryptophan

    Energy Technology Data Exchange (ETDEWEB)

    Manier, D.H.; Gillespie, D.D.; Sulser, F.

    1989-06-01

    Nonlinear regression analysis of agonist competition binding curves reveals that the (/sup 3/H)-dihydroalprenolol-labeled receptor population with low affinity for isoproterenol is increased by p-chlorophenylalanine (PCPA) and this increase is abolished by 5-hydroxytryptophan (5-HTP) in vivo. Desipramine (DMI) decreased the beta adrenoceptor population with high agonist affinity to the same degree in PCPA-treated animals as in control animals, thus explaining the reported discrepancy between beta adrenoceptor number and responsiveness of the beta adrenoceptor-coupled adenylate cyclase system. Mianserin also selectively reduced the beta adrenoceptor population with high agonist affinity in membrane preparations of normal animals, whereas fluoxetine selectively abolished the upregulation of the low affinity sites in reserpinized animals and had no effect on either receptor population from brain of normal animals. The results emphasize the importance of nonlinear regression analysis of agonist competition binding for the interpretation of drug action and encourage the pursuit of the molecular neurobiology of the serotonin (5-HT)/norepinephrine (NE) link in brain.

  12. Dual aminergic regulation of central beta adrenoceptors. Effect of atypical antidepressants and 5-hydroxytryptophan

    International Nuclear Information System (INIS)

    Manier, D.H.; Gillespie, D.D.; Sulser, F.

    1989-01-01

    Nonlinear regression analysis of agonist competition binding curves reveals that the [ 3 H]-dihydroalprenolol-labeled receptor population with low affinity for isoproterenol is increased by p-chlorophenylalanine (PCPA) and this increase is abolished by 5-hydroxytryptophan (5-HTP) in vivo. Desipramine (DMI) decreased the beta adrenoceptor population with high agonist affinity to the same degree in PCPA-treated animals as in control animals, thus explaining the reported discrepancy between beta adrenoceptor number and responsiveness of the beta adrenoceptor-coupled adenylate cyclase system. Mianserin also selectively reduced the beta adrenoceptor population with high agonist affinity in membrane preparations of normal animals, whereas fluoxetine selectively abolished the upregulation of the low affinity sites in reserpinized animals and had no effect on either receptor population from brain of normal animals. The results emphasize the importance of nonlinear regression analysis of agonist competition binding for the interpretation of drug action and encourage the pursuit of the molecular neurobiology of the serotonin (5-HT)/norepinephrine (NE) link in brain

  13. Effectiveness of interferon-beta and temozolomide combination therapy against temozolomide-refractory recurrent anaplastic astrocytoma

    Directory of Open Access Journals (Sweden)

    Arai Hajime

    2007-08-01

    Full Text Available Abstract Background Malignant gliomas recur even after extensive surgery and chemo-radiotherapy. Although a relatively novel chemotherapeutic agent, temozolomide (TMZ, has demonstrated promising activity against recurrent glioma, the effects last only a few months and drug resistance develops thereafter in most cases. Induction of O6-methylguanine-DNA methyltransferase (MGMT in tumors is considered to be responsible for resistance to TMZ. Interferon-beta has been reported to suppress MGMT in an experimental glioma model. Here we report a patient with TMZ-refractory anaplastic astrocytoma (AA who was treated successfully with a combination of interferon-beta and TMZ. Case presentation A patient with recurrent AA after radiation-chemotherapy and stereotactic radiotherapy was treated with TMZ. After 6 cycles, the tumor became refractory to TMZ, and the patient was treated with interferon-beta at 3 × 106 international units/body, followed by 5 consecutive days of 200 mg/m2 TMZ in cycles of 28 days. After the second cycle the tumor decreased in size by 50% (PR. The tumor showed further shrinkage after 8 months and the patient's KPS improved from 70% to 100%. The immunohistochemical study of the initial tumor specimen confirmed positive MGMT protein expression. Conclusion It is considered that interferon-beta pre-administration increased the TMZ sensitivity of the glioma, which had been refractory to TMZ monotherapy.

  14. Modeling the effects of repeated systemic administrations of small activity amounts In radionuclide therapy with beta emitters

    International Nuclear Information System (INIS)

    Calderon, Carlos; Gonzalez, Joaquin; Cepero, Janet; Colom, Camila; Rodriguez, Juan C.

    2008-01-01

    Full text: Good results for radionuclide therapy treatments where repeated short time spaced systemic injection of small activity amounts are given have been reported. Bone marrow and kidneys are usually considered as dose-limiting organs in radionuclide therapy. The treatments in radionuclide therapy with repeated administration could be optimized if irradiation effects in those one might be estimated. Xeno-grafted mice is the often biological model used during the evaluation of candidates for radionuclide therapy. A mathematical model of tumor cell kinetics was combined with another one reported for marrow cell kinetics which allows the calculation of marrow cell survival and proliferation in response to different irradiation schemes. Radionuclide therapy treatment with repeated administrations with radiopharmaceuticals labeled with beta emitters were simulated. The effects on fast-growing and slow-growing tumors were evaluated, as well as radiosensitive and radioresistant tumors. For more realistic estimation of absorbed dose in mice organs the cross-irradiation due to high energy beta particles was included into the MIRD's formula. Tumor and kidneys responses to the irradiation were estimated on the linear-quadratic model framework which was adapted for a multi-exponential dose rate function describing radionuclide therapy treatments with repeated administrations. Published values for murine tumors kinetics, marrows cellular turnover rates and radiosensitivities were used during the calculations. Iso-effective schemes were also determined varying the interval between fractions and the number of administration. For a given tolerated level of thrombocytopenia and absorbed dose in kidneys an optimal regime of radionuclide therapy with repeated administration could be found. The mathematical model presented here allows the prediction of the nadir and duration of thrombocytopenia, the effects on kidneys and the tumor cell response to various treatment schemes

  15. Characterization of GLP-1 effects on beta-cell function after meal ingestion in humans

    DEFF Research Database (Denmark)

    Ahrén, Bo; Holst, Jens Juul; Mari, Andrea

    2003-01-01

    OBJECTIVE: Glucagon-like peptide 1 (GLP-1) is an incretin that augments insulin secretion after meal intake and is developed for treatment of type 2 diabetes. As a novel therapeutic agent, characteristics of its beta-cell effects are important to establish. Previously, beta-cell effects of GLP-1...... have been characterized in humans during graded intravenous infusions of glucose, whereas its effects after more physiological stimuli, like meal intake, are not known. RESEARCH DESIGN AND METHODS: Eight women (aged 69 years, fasting glucose 3.7-10.3 mmol/l, BMI 22.4-43.9 kg/m(2)) who had fasted...... meal augments insulin secretion in humans by a dose...

  16. Negative effect of 17-beta-estradiol on growth parameters of goldfish (Carassius auratus

    Directory of Open Access Journals (Sweden)

    Reza Tarkhani

    2015-03-01

    Full Text Available Objective: To evaluate the effects of 17-beta-estradiol on growth factors of goldfish (Carassius auratus. Methods: To perform the test, 17-beta-estradiol was given 3 months period to fish at different doses as followed: control group, Group 1: 10 mg/kg food, Group 2: 25 mg/kg food and Group 3: 50 mg/kg food. For this purpose, a solution of hormone in pure ethanol used to spray on food. Feeding was done 3 times daily as an appetite. Comparing the mean values measured for length and weight using ANOVA. Results: Indicated with increase length and weight, the effects of the hormone get more distinct, so that with increase concentration of hormone, reduce weight and length. Conclusions: Estradiol along with testosterone and progesterone regulates final stages of oocyte maturation and ovulation. Various studies have proven the different concentrations of this hormone has different effects on the growth of different fishes.

  17. Effect of particle shape on mechanical behaviors of rocks: a numerical study using clumped particle model.

    Science.gov (United States)

    Rong, Guan; Liu, Guang; Hou, Di; Zhou, Chuang-Bing

    2013-01-01

    Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied.

  18. The effects of realistic pancake solenoids on particle transport

    Science.gov (United States)

    Gu, X.; Okamura, M.; Pikin, A.; Fischer, W.; Luo, Y.

    2011-05-01

    Solenoids are widely used to transport or focus particle beams. Usually, they are assumed as being ideal solenoids with a high axial-symmetry magnetic field. Using the Vector Fields Opera program, we modeled asymmetrical solenoids with realistic geometry defects, caused by finite conductor and current jumpers. Their multipole magnetic components were analyzed with the Fourier fit method; we present some possible optimized methods for them. We also discuss the effects of "realistic" solenoids on low energy particle transport. The findings in this paper may be applicable to the lower energy particle transport system design.

  19. Bandwagon effects and error bars in particle physics

    International Nuclear Information System (INIS)

    Jeng, Monwhea

    2007-01-01

    We study historical records of experiments on particle masses, lifetimes, and widths, both for signs of expectation bias, and to compare actual errors with reported error bars. We show that significant numbers of particle properties exhibit 'bandwagon effects': reported values show trends and clustering as a function of the year of publication, rather than random scatter about the mean. While the total amount of clustering is significant, it is also fairly small; most individual particle properties do not display obvious clustering. When differences between experiments are compared with the reported error bars, the deviations do not follow a normal distribution, but instead follow an exponential distribution for up to ten standard deviations

  20. Bandwagon effects and error bars in particle physics

    Science.gov (United States)

    Jeng, Monwhea

    2007-02-01

    We study historical records of experiments on particle masses, lifetimes, and widths, both for signs of expectation bias, and to compare actual errors with reported error bars. We show that significant numbers of particle properties exhibit "bandwagon effects": reported values show trends and clustering as a function of the year of publication, rather than random scatter about the mean. While the total amount of clustering is significant, it is also fairly small; most individual particle properties do not display obvious clustering. When differences between experiments are compared with the reported error bars, the deviations do not follow a normal distribution, but instead follow an exponential distribution for up to ten standard deviations.

  1. The effect of particle shape and size on cellular uptake.

    Science.gov (United States)

    Zheng, M; Yu, J

    2016-02-01

    Particle shape and size have been well-recognized to exhibit important effect on drug delivery and as an excellent candidate for drug delivery applications. The recent advances in the "top-down" and "bottom-up" approaches make it possible to develop different shaped and sized polymeric nanostructures, which provide a chance to tailor the shape of the nanostructures as a drug carrier. Presently, a large amount of cellular uptake data is available for particle shape and size effect on drug delivery. However, the effect has not been well formulated or described quantitatively. In the present paper, the dynamic process of the effects of particle shape and size on cellular uptake is analyzed, quantitative expression for the influence of particle shape and size on cellular uptake is proposed on the basis of local geometric feature of particle shape and diffusion approach of a particle in a medium rationally, and the relevant parameters in the formulation are determined by the available test data. The results indicate the validity of the present formulations.

  2. Aspartate beta-decarboxylase from Alcaligenes faecalis: carbon-13 kinetic isotope effect and deuterium exchange experiments

    International Nuclear Information System (INIS)

    Rosenberg, R.M.; O'Leary, M.H.

    1985-01-01

    The authors have measured the 13 C kinetic isotope effect at pH 4.0, 5.0, 6.0, and 6.5 and in D 2 O at pH 5.0 and the rate of D-H exchange of the alpha and beta protons of aspartic acid in D 2 O at pH 5.0 for the reaction catalyzed by the enzyme aspartate beta-decarboxylase from Alcaligenes faecalis. The 13 C kinetic isotope effect, with a value of 1.0099 +/- 0.0002 at pH 5.0, is less than the intrinsic isotope effect for the decarboxylation step, indicating that the decarboxylation step is not entirely rate limiting. The authors have been able to estimate probable values of the relative free energies of the transition states of the enzymatic reaction up to and including the decarboxylation step from the 13 C kinetic isotope effect and the rate of D-H exchange of alpha-H. The pH dependence of the kinetic isotope effect reflects the pKa of the pyridine nitrogen of the coenzyme pyridoxal 5'-phosphate but not that of the imine nitrogen. A mechanism is proposed for the exchange of aspartate beta-H that is consistent with the stereochemistry suggested earlier

  3. Effect of HZE particles and space hadrons on bacteriophages

    International Nuclear Information System (INIS)

    Iurov, S.S.; Akoev, I.G.; Leonteva, G.A.

    1983-01-01

    The effects of particle radiation of the type encountered in space flight on bacteriophages are investigated. Survival and mutagenesis were followed in dry film cultures or liquid suspensions of T4Br(+) bacteriophage exposed to high-energy (HZE) particles during orbital flight, to alpha particles and accelerator-generated hardrons in the laboratory, and to high-energy cosmic rays at mountain altitudes. The HZE particles and high-energy hadrons are found to have a greater relative biological efficiency than standard gamma radiation, while exhibiting a highly inhomogeneous spatial structure in the observed biological and genetic effects. In addition, the genetic lesions observed are specific to the type of radiation exposure, consisting primarily of deletions and multiple lesions of low revertability, with mode of action depending on the linear energy transfer. 18 references

  4. Effects of Kaolin particle size and annealing temperature on the ...

    African Journals Online (AJOL)

    The effects of kaolin particle sizes on the resistivity of zinc-kaolin composite resistors have been investigated. The composite resistors have been produced from kaolin particle sizes ranging from 0.063 mm to 0.5 mm. The resistors were produced in a mould to a dimension of 65 mm x 6.5 mm x 3.2 mm with dry zinc and ...

  5. Towards Measurements of Chiral Effects Using Identified Particles from STAR

    Czech Academy of Sciences Publication Activity Database

    Wen, Lw.; Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Bielčík, J.; Bielčíková, Jana; Chaloupka, P.; Federič, Pavol; Rusňák, Jan; Rusňáková, O.; Šimko, Miroslav; Šumbera, Michal; Vértési, Robert

    2017-01-01

    Roč. 967, č. 11 (2017), s. 756-759 ISSN 0375-9474 R&D Projects: GA MŠk LG15001; GA MŠk LM2015054 Institutional support: RVO:61389005 Keywords : STAR collaboration * chiral magnetic effect * chiral magnetic wave * gamma correlation * k(K) parameter Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 1.916, year: 2016

  6. Size-dependent nonlocal effects in plasmonic semiconductor particles

    DEFF Research Database (Denmark)

    Maack, Johan Rosenkrantz; Mortensen, N. Asger; Wubs, Martijn

    2017-01-01

    Localized surface plasmons (LSP) in semiconductor particles are expected to exhibit spatial nonlocal response effects as the geometry enters the nanometer scale. To investigate these nonlocal effects, we apply the hydrodynamic model to nanospheres of two different semiconductor materials: intrinsic...... InSb and n-doped GaAs. Our results show that the semiconductors indeed display nonlocal effects, and that these effects are even more pronounced than in metals. In a 150 nm InSb particle at 300 K, the LSP frequency is blueshifted 35%, which is orders of magnitude larger than the blueshift in a metal...... particle of the same size. This property, together with their tunability, makes semiconductors a promising platform for experiments in nonlocal effects. Copyright (C)EPLA, 2017...

  7. Effect of beta-alanine and carnosine supplementation on muscle contractility in mice.

    Science.gov (United States)

    Everaert, Inge; Stegen, Sanne; Vanheel, Bert; Taes, Youri; Derave, Wim

    2013-01-01

    Enhanced carnosine levels have been shown to be ergogenic for high-intensity exercise performances, although the role of carnosine in the control of muscle function is poorly understood. Therefore, the aim of this study was to investigate the effect of long-term supplementation with increasing doses of carnosine and beta-alanine on muscle carnosine, anserine, and taurine levels and on in vitro contractility and fatigue in mice. Male Naval Medical Research Institute mice (n = 66) were control fed or supplemented with either carnosine (0.1%, 0.5%, or 1.8%) or beta-alanine (0.6 or 1.2%) in their drinking water for 8-12 wk. Soleus and extensor digitorum longus (EDL) were tested for in vitro contractile properties, and carnosine, anserine, and taurine content were measured in EDL and tibialis anterior by high-performance liquid chromatography. Only supplementation with 1.8% carnosine and 1.2% beta-alanine resulted in markedly higher carnosine (up to +160%) and anserine levels (up to +46%) compared with control mice. Beta-alanine supplementation (1.2%) resulted in increased fatigue resistance in the beginning of the fatigue protocol in soleus (+2%-4%) and a marked leftward shift of the force-frequency relation in EDL (10%-31% higher relative forces). Comparable with humans, beta-alanine availability seems to be the rate-limiting step for synthesis of muscle histidine-containing dipeptides in mice. Moreover, muscle histidine-containing dipeptides loading in mice moderately and muscle dependently affects excitation-contraction coupling and fatigue.

  8. Effect of hydrostatic pressure of various magnitudes on osteoarthritic chondrocytes exposed to IL-1beta.

    Science.gov (United States)

    Fioravanti, Antonella; Collodel, Giulia; Petraglia, Angela; Nerucci, Fabiola; Moretti, Elena; Galeazzi, Mauro

    2010-08-01

    Several in vitro studies have shown the importance of mechanical compression or hydrostatic pressure (HP) as a modulator of cartilage metabolism. The present study was undertaken to evaluate the in vitro effects of cyclical low HP (1-5 MPa) and continuous high HP (24 MPa) applied in the presence or absence of interleukin (IL)-1beta on human osteoarthritis (OA) chondrocytes. Chondrocytes obtained from OA cartilage were cultivated for 48 h and then exposed to pressurization in the presence or absence of IL-1beta. After pressurization, the culture medium was collected to detect the amount of proteoglycans (PG) and nitric oxide (NO) and the chondrocytes were immediately fixed for transmission electron microscopy (TEM) and processed for immunocytochemistry to localize the inducible nitric oxide synthase (iNOS). A significant increase in the level of PG and a small, non-significant, decrease in NO production were observed upon exposure to cyclical low HP. On the other hand, exposure to continuous high HP resulted in a significant decrease in the PG levels and a significant increase in NO production. The presence of IL-1beta led to a significant decrease in PG levels as well as a significant increase in NO production. The cyclical low HP did not increase the PG levels significantly but caused a statistically significant decrease in NO production in cultures damaged with IL-1beta. The continuous high HP in chondrocyte cultures stimulated with IL-1beta did not significantly decrease PG production, but significantly increased NO production. The results concerning metabolic production were further confirmed by morphological findings obtained by TEM and immunocytochemical studies. The findings of this study confirmed that the response of chondrocytes varies with magnitude and frequency of HP. These findings are important to understand aetiopathogenetic mechanisms of OA and to find out which type of physical activity may be best suited for the prevention and therapy of OA.

  9. Effect of experimenter-delivered and self-administered cocaine on extracellular beta-endorphin levels in the nucleus accumbens.

    Science.gov (United States)

    Roth-Deri, I; Zangen, A; Aleli, M; Goelman, R G; Pelled, G; Nakash, R; Gispan-Herman, I; Green, T; Shaham, Y; Yadid, G

    2003-03-01

    Beta-endorphin is an endogenous opioid peptide that has been hypothesized to be involved in the behavioral effects of drugs of abuse including psychostimulants. Using microdialysis, we studied the effect of cocaine on extracellular levels of beta-endorphin in the nucleus accumbens, a brain region involved in the reinforcing effects of psychostimulant drugs. Experimenter-delivered cocaine (2 mg/kg, i.v.) increased extracellular beta-endorphin immunoreactive levels in the nucleus accumbens, an effect attenuated by 6-hydroxy-dopamine lesions or systemic administration of the D1-like receptor antagonist, SCH-23390 (0.25 mg/kg, i.p.). The effect of cocaine on beta-endorphin release in the nucleus accumbens was mimicked by a local perfusion of dopamine (5 microm) and was blocked by coadministration of SCH-23390 (10 microm). Self-administered cocaine (1 mg/kg/infusion, i.v.) also increased extracellular beta-endorphin levels in the nucleus accumbens. In addition, using functional magnetic resonance imaging, we found that cocaine (1 mg/kg, i.v.) increases regional brain activity in the nucleus accumbens and arcuate nucleus. We demonstrate an increase in beta-endorphin release in the nucleus accumbens following experimenter-delivered and self-administered cocaine mediated by the local dopaminergic system. These findings suggest that activation of the beta-endorphin neurons within the arcuate nucleus-nucleus accumbens pathway may be important in the neurobiological mechanisms underlying the behavioral effects of cocaine.

  10. Transport effects due to particle erosion mechanisms. [in planetary rings

    Science.gov (United States)

    Durisen, R. H.

    1984-01-01

    Various processes can erode the surfaces of planetary ring particles. Recent estimates for Saturn's rings suggest that a centimeter-thick surface layer could be eroded from an isolated ring particle in less than 1000 yr by meteoroid impacts alone. The atoms, molecules, and chips ejected from ring particles by erosion will arc across the rings along elliptical orbits. For moderate ring optical depths, ejecta will be absorbed or inelastically scattered upon reintersecting the ring plane. Continuous exchange of ejecta between different ring regions can lead to net radial transport of mass and angular momentum, to changes in particle sizes, and to the buildup of chip regoliths several centimeters deep on the surfaces of ring particles. Because most of the erosional ejecta are not lost but merely exchanged over short distances, the net erosion rate of the surfaces of these ring particles will be much less than that estimated for an isolated particle. Numerical solutions for time-dependent ballistic transport under various assumptions suggest pile-up and spillover effects especially near regions of preexisting high optical depth contrast, such as the inner edges of A and B rings. Global redistribution could be significant over billions of years. Other features in planetary ring systems may be influenced by ballistic transport.

  11. Testosterone sorption and desorption: Effects of soil particle size

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Yong, E-mail: yqi01@unomaha.edu [Civil Engineering Dept., University of Nebraska-Lincoln at Omaha Campus, Omaha, NE 68182 (United States); Zhang, Tian C. [Civil Engineering Dept., University of Nebraska-Lincoln at Omaha Campus, Omaha, NE 68182 (United States); Ren, Yongzheng [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-08-30

    Graphical abstract: - Highlights: • Smaller soil particles have higher sorption and lower desorption rates. • The sorption capacity ranks as clay > silt > sand. • Small particles like clays have less potential for desorption. • Colloids (clays) have high potential to facilitate the transport of hormones in soil–water environments. - Abstract: Soils contain a wide range of particles of different diameters with different mobility during rainfall events. Effects of soil particles on sorption and desorption behaviors of steroid hormones have not been investigated. In this study, wet sieve washing and repeated sedimentation methods were used to fractionate the soils into five ranges. The sorption and desorption properties and related mechanisms of testosterone in batch reactors filled with fractionated soil particles were evaluated. Results of sorption and desorption kinetics indicate that small soil particles have higher sorption and lower desorption rates than that of big ones. Thermodynamic results show the sorption processes are spontaneous and exothermal. The sorption capacity ranks as clay > silt > sand, depending mainly on specific surface area and surface functional groups. The urea control test shows that hydrogen bonding contributes to testosterone sorption onto clay and silt but not on sand. Desorption tests indicate sorption is 36–65% irreversible from clay to sand. Clays have highest desorption hysteresis among these five soil fractions, indicating small particles like clays have less potential for desorption. The results provide indirect evidence on the colloid (clay)-facilitated transport of hormones (micro-pollutants) in soil environments.

  12. Chemical imaging of catalyst deactivation during the conversion of renewables at the single particle level: etherification of biomass-based polyols with alkenes over H-Beta zeolites.

    Science.gov (United States)

    Parvulescu, Andrei N; Mores, Davide; Stavitski, Eli; Teodorescu, Cristian M; Bruijnincx, Pieter C A; Gebbink, Robertus J M Klein; Weckhuysen, Bert M

    2010-08-04

    The etherification of biomass-based alcohols with various linear alpha-olefins under solvent-free conditions was followed in a space- and time-resolved manner on 9 microm large H-Beta zeolite crystals by confocal fluorescence microscopy. This allowed us to visualize the interaction with the substrate and distribution of the coke products into the catalyst at the level of an individual zeolite crystal during the etherification process. The spectroscopic information obtained on the micrometer-scale zeolite was in line with the results obtained with bulk characterization techniques and further confirmed by the catalytic results obtained both for micrometer-scale and nanoscale zeolites. This allowed us to explain the influence of the substrate type (glycerol, glycols, and alkenes) and zeolite properties (Si/Al ratio and particle size) on the etherification activity. The etherification of the biomass-based alcohols takes place mainly on the external surface of the zeolite particles. The gradual blockage of the external surface of the zeolite results in a partial or total loss of etherification activity. The deactivation could be attributed to olefin oligomerization. The high conversions obtained in the etherification of 1,2-propylene glycol with long linear alkenes (up to 80%) and the pronounced deactivation of the zeolite observed in the etherification of glycerol with long linear alkenes (max. 20% conversion) were explained by the spectroscopic measurements and is due to differences in the adsorption, i.e., in the center of the zeolite particle for glycerol and on the external surface in the case of glycols.

  13. Effect of Surface Modification and Macrophage Phenotype on Particle Internalization

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Daniel [Iowa State University; Phan, Ngoc [Iowa State University; Isely, Christopher [Iowa State University; Bruene, Lucas [Iowa State University; Bratlie, Kaitlin M [Ames Laboratory

    2014-11-10

    Material properties play a key role in the cellular internalization of polymeric particles. In the present study, we have investigated the effects of material characteristics such as water contact angle, zeta potential, melting temperature, and alternative activation of complement on particle internalization for pro-inflammatory, pro-angiogenic, and naïve macrophages by using biopolymers (~600 nm), functionalized with 13 different molecules. Understanding how material parameters influence particle internalization for different macrophage phenotypes is important for targeted delivery to specific cell populations. Here, we demonstrate that material parameters affect the alternative pathway of complement activation as well as particle internalization for different macrophage phenotypes. Here, we show that the quantitative structure–activity relationship method (QSAR) previously used to predict physiochemical properties of materials can be applied to targeting different macrophage phenotypes. These findings demonstrated that targeted drug delivery to macrophages could be achieved by exploiting material parameters.

  14. RBE [relative biological effectiveness] of tritium beta radiation to gamma radiation and x-rays analyzed by both molecular and genetic methods

    International Nuclear Information System (INIS)

    Lee, W.R.

    1988-01-01

    The relative biological effectiveness (RBE) of tritium beta radiation to 60 Co gamma radiation was determined using sex-linked recessive lethals (SLRL) induced in Drosophila melanogaster spermatozoa as the biological effect. The SLRL test, a measure of mutations induced in germ cells transmitted through successive generations, yields a linear dose-response curve in the range used in these experiments. From these ratios of the slopes of the 3 H beta and the 60 Co gamma radiation linear dose response curves, an RBE of 2.7 is observed. When sources of error are considered, this observation suggests that the tritium beta particle is 2.7 ± 0.3 times more effective per unit of energy absorbed in inducing gene mutations transmitted to successive generation than 60 Co gamma radiation. Ion tracks with a high density of ions (high LET) are more efficient than tracks with a low ion density (low LET) in inducing transmissible mutations, suggesting interaction among products of ionization. Molecular analysis of x-ray induced mutations shows that most mutations are deletions ranging from a few base pairs as determined from sequence data to multi locus deletions as determined from complementation tests and Southern blots. 14 refs., 1 fig

  15. Integral validation of the effective beta parameter for the MOX reactors and incinerators; Validation integrale des estimations du parametre beta effectif pour les reacteurs Mox et incinerateurs

    Energy Technology Data Exchange (ETDEWEB)

    Zammit-Averlant, V

    1998-11-19

    {beta}{sub eff}, which represents the effective delayed neutron fraction, is an important parameter for the reactor nominal working as well as for studies of its behaviour in accidental situation. In order to improve the safety of nuclear reactors, we propose here to validate its calculation by using the ERANOS code with ERALIB1 library and by taking into account all the fission process physics through the {nu} energy dependence. To validate the quality of this calculation formalism, we calculated uncertainties as precisely as possible. The experimental values of {beta}{sub eff}, as well their uncertainties, have also been re-evaluated for consistency, because these `experimental` values actually contain a calculated component. We therefore obtained an entirely coherent set of calculated and measured {beta}{sub eff}. The comparative study of the calculated and measured values pointed out that the JEF2.2 {nu}{sub d} are already sufficient because the (E-C)/C are inferior to 3 % in average and in their uncertainly bars. The experimental uncertainties, even if lightly superior to those previously edited, remain inferior to the uncertainties of the calculated values. This allowed us to fit {nu}{sub d} with {beta}{sub eff}. This adjustment has brought an additional improvement on the recommendations of the {nu}{sub d} average values, for the classical scheme (thermal energy, fast energy) and for the new scheme which explains the {nu}{sub d} energy dependence. {beta}{sub eff}, for MOX or UOX fuel assemblies in thermal or fast configurations, can therefore be obtained with an uncertainty due to the nuclear data of about 2.0 %. (author) 110 refs.

  16. Differential effect on serum neopterin and serum beta 2-microglobulin is induced by treatment in Pneumocystis carinii pneumonia

    DEFF Research Database (Denmark)

    Benfield, T L; Schattenkerk, J K; Hofmann, B

    1994-01-01

    Forty-three human immunodeficiency virus-infected patients with Pneumocystis carinii pneumonia (PCP) were enrolled in a study of adjunctive corticosteroid treatment for 10 days versus placebo, in addition to antimicrobial treatment. Levels of neopterin and beta 2-microglobulin (beta 2M) were...... determined in consecutive serum samples. Initiation of antimicrobial treatment resulted in significantly increased neopterin levels, whereas beta 2M levels slightly decreased from pretreatment levels. In patients treated with corticosteroid, both neopterin and beta 2M decreased, by approximately 50......% and approximately 30%, respectively, and returned to baseline after discontinuation of corticosteroid treatment. Antimicrobial treatment alone did not affect either neopterin or beta 2M in healthy controls. Results indicate that treatment has a differential effect on the immune response: increased macrophage...

  17. Rapid effects of phytoestrogens on human colonic smooth muscle are mediated by oestrogen receptor beta.

    LENUS (Irish Health Repository)

    Hogan, A M

    2012-02-01

    Epidemiological studies have correlated consumption of dietary phytoestrogens with beneficial effects on colon, breast and prostate cancers. Genomic and non-genomic mechanisms are responsible for anti-carcinogenic effects but, until now, the effect on human colon was assumed to be passive and remote. No direct effect on human colonic smooth muscle has previously been described. Institutional research board approval was granted. Histologically normal colon was obtained from the proximal resection margin of colorectal carcinoma specimens. Circular smooth muscle strips were microdissected and suspended under 1g of tension in organ baths containing oxygenated Krebs solution at 37 degrees C. After an equilibration period, tissues were exposed to diarylpropionitrile (DPN) (ER beta agonist) and 1,3,5-tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT) (ER alpha agonist) or to the synthetic phytoestrogen compounds genistein (n=8), daidzein (n=8), fisetin (n=8) and quercetin (n=8) in the presence or absence of fulvestrant (oestrogen receptor antagonist). Mechanism of action was investigated by inhibition of downstream pathways. The cholinergic agonist carbachol was used to induce contractile activity. Tension was recorded isometrically. Phytoestrogens inhibit carbachol-induced colonic contractility. In keeping with a non-genomic, rapid onset direct action, the effect was within minutes, reversible and similar to previously described actions of 17 beta oestradiol. No effect was seen in the presence of fulvestrant indicating receptor modulation. While the DPN exerted inhibitory effects, PPT did not. The effect appears to be reliant on a p38\\/mitogen activated protein kinase mediated induction of nitric oxide production in colonic smooth muscle. The present data set provides the first description of a direct effect of genistein, daidzein, fisetin and quercetin on human colonic smooth muscle. The presence of ER in colonic smooth muscle has been functionally proven and the beta

  18. Effects of Particle Size Distribution on Bioremediation of Crude Oil ...

    African Journals Online (AJOL)

    Bioremediation has been proven to be the most effective method of cleaning up oil contaminated soils through the application of nutrients and microorganism. Hence, this research presents the effects of particle size distribution on bioremediation of crude oil polluted sandy soils. Six different soil samples were sieved using ...

  19. Shielding effectiveness of superconductive particles in plastics

    International Nuclear Information System (INIS)

    Pienkowski, T.; Kincaid, J.; Lanagan, M.T.; Poeppel, R.B.; Dusek, J.T.; Shi, D.; Goretta, K.C.

    1988-09-01

    The ability to cool superconductors with liquid nitrogen instead of liquid helium has opened the door to a wide range of research. The well known Meissner effect, which states superconductors are perfectly diamagnetic, suggests shielding applications. One of the drawbacks to the new ceramic superconductors is the brittleness of the finished material. Because of this drawback, any application which required flexibility (e.g., wire and cable) would be impractical. Therefore, this paper presents the results of a preliminary investigation into the shielding effectiveness of YBa 2 Cu 3 O/sub 7-x/ both as a composite and as a monolithic material. Shielding effectiveness was measured using two separate test methods. One tested the magnetic (near field) shielding, and the other tested the electromagnetic (far field) shielding. No shielding was seen in the near field measurements on the composite samples, and only one heavily loaded sample showed some shielding in the far field. The monolithic samples showed a large amount of magnetic shielding. 5 refs., 5 figs

  20. Particle contamination effects in EUVL: enhanced theory for the analytical determination of critical particle sizes

    Science.gov (United States)

    Brandstetter, Gerd; Govindjee, Sanjay

    2012-03-01

    Existing analytical and numerical methodologies are discussed and then extended in order to calculate critical contamination-particle sizes, which will result in deleterious effects during EUVL E-chucking in the face of an error budget on the image-placement-error (IPE). The enhanced analytical models include a gap dependant clamping pressure formulation, the consideration of a general material law for realistic particle crushing and the influence of frictional contact. We present a discussion of the defects of the classical de-coupled modeling approach where particle crushing and mask/chuck indentation are separated from the global computation of mask bending. To repair this defect we present a new analytic approach based on an exact Hankel transform method which allows a fully coupled solution. This will capture the contribution of the mask indentation to the image-placement-error (estimated IPE increase of 20%). A fully coupled finite element model is used to validate the analytical models and to further investigate the impact of a mask back-side CrN-layer. The models are applied to existing experimental data with good agreement. For a standard material combination, a given IPE tolerance of 1 nm and a 15 kPa closing pressure, we derive bounds for single particles of cylindrical shape (radius × height < 44 μm) and spherical shape (diameter < 12 μm).

  1. Memory effect for particle scattering in odd spacetime dimensions

    Science.gov (United States)

    Satishchandran, Gautam; Wald, Robert M.

    2018-01-01

    We investigate the gravitational memory effect for linearized perturbations off of Minkowski space in odd spacetime dimensions d by examining the effects of gravitational radiation from classical point particle scattering. We also investigate analogous memory effects for electromagnetic and scalar radiation. We find that there is no gravitational memory effect in all odd dimensions. For scalar and electromagnetic fields, there is no memory effect for d ≥7 ; for d =3 there is an infinite momentum memory effect, whereas for d =5 there is no momentum memory effect but the displacement of a test particle will grow unboundedly with time. Our results are further elucidated by analyzing the memory effect for any slowly moving source of compact spatial support in odd dimensions.

  2. BETA digital beta radiometer

    International Nuclear Information System (INIS)

    Borovikov, N.V.; Kosinov, G.A.; Fedorov, Yu.N.

    1989-01-01

    Portable transportable digital beta radiometer providing for measuring beta-decay radionuclide specific activity in the range from 5x10 -9 up to 10 -6 Cu/kg (Cu/l) with error of ±25% is designed and introduced into commercial production for determination of volume and specific water and food radioactivity. The device specifications are given. Experience in the BETA radiometer application under conditions of the Chernobyl' NPP 30-km zone has shown that it is convenient for measuring specific activity of the order of 10 -8 Cu/kg, and application of a set of different beta detectors gives an opportunity to use it for surface contamination measurement in wide range of the measured value

  3. Self-assembly of a novel beta-In2S3 nanostructure exhibiting strong quantum confinement effects.

    Science.gov (United States)

    Zhang, Wu; Ma, Dekun; Huang, Zhen; Tang, Qun; Xie, Qin; Qian, Yitai

    2005-05-01

    The 3D beta-In2S3 flowerlike architecture assembled from nanoflakes was prepared via a novel complex-precursor assisted (CPA) solvothermal route. The as-prepared beta-In2S3 powder was characterized by X-ray diffraction pattern (XRD), X-ray photoelectron spectra (XPS), transition electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), ultraviolet-visible light (UV-vis) spectra, and photoluminescence spectrum. The novel 3D beta-In2S3 nanostructure exhibit a strong quantum confinement effect. FT-IR spectra were used to investigate the coordinative chemical effect in the complex. A possible mechanism was discussed.

  4. Improvements to the on-line mass separator, RAMA, and the beta-delayed charged-particle emission of proton-rich sd shell nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ognibene, Theodore Joseph [Lawrence Berkeley National Lab., CA (United States). Nuclear Science Div.

    1996-03-01

    To overcome the extreme difficulties encountered in the experimental decay studies of proton drip line nuclei, several techniques have been utilized, including a helium-jet transport system, particle identification detectors and mass separation. Improvements to the ion source/extraction region of the He-jet coupled on-line Recoil Atom Mass Analyzer (RAMA) and its target/ion source coupling resulted in significant increases in RAMA efficiencies and its mass resolution, as well as reductions in the overall transit time. At the 88-Inch Cyclotron at LBNL, the decays of 31Cl, 27P and 28P, with half-lives of 150 msec, 260 msec and 270.3 msec, respectively, were examined using a he-jet and low-energy gas ΔE-gas ΔE-silicon E detector telescopes. Total beta-delayed proton branches of 0.3% and 0.07% in 31Cl and 27P, respectively, were estimated. Several proton peaks that had been previously assigned to the decay of 31Cl were shown to be from the decay of 25Si. In 27P, two proton groups at 459 ± 14 keV and 610 ± 11 keV, with intensities of 7 ± 3% and 92 ± 4% relative to the main (100%) group were discovered. The Gamow-Teller component of the preceding beta-decay of each observed proton transition was compared to results from shell model calculations. Finally, a new proton transition was identified, following the β-decay of 28P, at 1,444 ± 12 keV with a 1.7 ± 0.5% relative intensity to the 100% group. Using similar low-energy detector telescopes and the mass separator TISOL at TRIUMF, the 109 msec and 173 msec activities, 17Ne and 33Ar, were studied. A new proton group with energy 729 ± 15 keV was observed following the beta-decay of 17Ne. Several discrepancies between earlier works as to the energies, intensities and assignments of several proton transitions from 17Ne and 33Ar were resolved.

  5. Improvements to the on-line mass separator, RAMA, and the beta-delayed charged-particle emission of proton-rich sd shell nuclei

    International Nuclear Information System (INIS)

    Ognibene, T.J.

    1996-03-01

    To overcome the extreme difficulties encountered in the experimental decay studies of proton drip line nuclei, several techniques have been utilized, including a helium-jet transport system, particle identification detectors and mass separation. Improvements to the ion source/extraction region of the He-jet coupled on-line Recoil Atom Mass Analyzer (RAMA) and its target/ion source coupling resulted in significant increases in RAMA efficiencies and its mass resolution, as well as reductions in the overall transit time. At the 88-Inch Cyclotron at LBNL, the decays of 31 Cl, 27 P and 28 P, with half-lives of 150 msec, 260 msec and 270.3 msec, respectively, were examined using a he-jet and low-energy gas ΔE-gas ΔE-silicon E detector telescopes. Total beta-delayed proton branches of 0.3% and 0.07% in 31 Cl and 27 P, respectively, were estimated. Several proton peaks that had been previously assigned to the decay of 31 Cl were shown to be from the decay of 25 Si. In 27 P, two proton groups at 459 ± 14 keV and 610 ± 11 keV, with intensities of 7 ± 3% and 92 ± 4% relative to the main (100%) group were discovered. The Gamow-Teller component of the preceding beta-decay of each observed proton transition was compared to results from shell model calculations. Finally, a new proton transition was identified, following the β-decay of 28 P, at 1,444 ± 12 keV with a 1.7 ± 0.5% relative intensity to the 100% group. Using similar low-energy detector telescopes and the mass separator TISOL at TRIUMF, the 109 msec and 173 msec activities, 17 Ne and 33 Ar, were studied. A new proton group with energy 729 ± 15 keV was observed following the beta-decay of 17 Ne. Several discrepancies between earlier works as to the energies, intensities and assignments of several proton transitions from 17 Ne and 33 Ar were resolved

  6. Superbubbles and Energetic Particles in the Galaxy. I: Collective effects of particle acceleration

    OpenAIRE

    Parizot, E.; Marcowith, A.; van der Swaluw, E.; Bykov, A. M.; Tatischeff, V.

    2004-01-01

    Observations indicate that most massive stars in the Galaxy appear in groups, called OB associations, where their strong wind activity generates large structures known as superbubbles, inside which the subsequent supernovae (SNe) explode, in tight space and time correlation. Acknowledging this fact, we investigate four main questions: 1) does the clustering of massive stars and SN explosions influence the particle acceleration process usually associated with SNe, and induce collective effects...

  7. Particle dynamics and particle heat and mass transfer in thermal plasmas. Part I. The motion of a single particle without thermal effects

    International Nuclear Information System (INIS)

    Pfender, E.; Lee, Y.C.

    1985-01-01

    A particle injected into a thermal plasma will experience a number of effects which are not present in an ordinary gas. In this paper effects exerted on the motionof a particle will be reviewed and analyzed in the context of thermal plasma processing of materials. The primary purpose of this paper is an assessment of the relative importance of various effects on particle motion. Computer experiments are described, simulating motion of a spherical particle in a laminar, confined plasma jet or in a turbulent, free plasma jet. Particle sizes range from 5 to 50 μ and as sample materials alumina and tungsten are considered. The results indicate that (i) the correction term required for the viscous drag coefficient due to strongly varying properties is the most important factor; (ii) non-continum effects are important for particle sizes <10 μ at atmospheric pressure and these effects will be enhanced for smaller particles and/or reduced pressures; (iii) the Basset history term is negligible, unless relatively large and light particles are considered over long processing distances; (iv) thermophoresis is not crucial for the injection of particles into thermal plasma; (v) turbulent dispersion becomes important for particle <10 μ in diameter

  8. Effect of {beta}{sub 1} adrenergic receptor blockade on myocardial blood flow and vasodilatory capacity

    Energy Technology Data Exchange (ETDEWEB)

    Boettcher, M.; Czernin, J.; Sun, K. [Univ. of California, Los Angeles, CA (United States)] [and others

    1997-03-01

    The {beta}{sub 1} receptor blockade reduces cardiac work and may thereby lower myocardial blood flow (MBF) at rest. The effect of {beta}{sub 1} receptor blockade on hyperemic MBF is unknown. To evaluate the effect of selective {beta}{sub 1} receptor blockade on MBF at rest and during dipyridamole induced hyperemia, 10 healthy volunteers (8 men, 2 women, mean age 24 {+-} 5 yr) were studied using {sup 13}N-ammonia PET (two-compartment model) under control conditions and again during metoprolol (50 mg orally 12 hr and 1 hr before the study). The resting rate pressure product (6628 {+-} 504 versus 5225 {+-} 807) and heart rate (63 {+-} 6-54 {plus_minus} 5 bpm) declined during metoprolol (p < 0.05). Similarly, heart rate and rate pressure product declined from the baseline dipyridamole study to dipyridamole plus metoprolol (p < 0.05). Resting MBF declined in proportion to cardiac work by approximately 20% from 0.61 {+-} 0.09-0.51 {+-} 0.10 ml/g/min (p < 0.05). In contrast, hyperemic MBF increased when metoprolol was added to dipyridamole (1.86 {plus_minus} 0.27 {+-} 0.45 ml/g/min; p<0.05). The decrease in resting MBF together with the increase in hyperemic MBF resulted in a significant increase in the myocardial flow reserve during metoprolol (3.14 {+-} 0.80-4.61 {+-} 0.68; p<0.01). The {beta}{sub 1} receptor blockade increases coronary vasodilatory capacity and myocardial flow reserve. However, the mechanisms accounting for this finding remain uncertain. 32 refs., 2 figs., 2 tabs.

  9. Effect of natural {beta}-carotene supplementation in children exposed to radiation from the Chernobyl accident

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Amotz, A. [Israel Oceanographic and Limnological Research, Haifa (Israel); Yatziv, S. [Pediatric Department, Hadassah University Hospital, Jerusalem (Israel); Sela, M. [Maxillary-Facial Rehabilitation, Hadassah University Hospital, Jerusalem (Israel); Greenberg, S.; Rachmilevich, B.; Shwarzman, M.; Weshler, Z. [Sharett Institute of Oncology, Hadassah University Hospital, Jerusalem (Israel)

    1998-10-01

    Attempts were made to evaluate 709 children (324 boys and 385 girls) who had been exposed long-term to different doses of radiation during and after the Chernobyl accident and had moved to Israel between 1990 and 1994. Upon arrival, all of them underwent a check-up for most common clinical disorders and were then divided into three groups according to their residences (distance from the reactor) and the level of irradiation exposure: no radiation, <5 Ci/m{sup 2}, and >5 Ci/m{sup 2}, respectively. Blood serum analyses for total carotenoids, retinol, {alpha}-tocopherol and oxidized conjugated dienes in 262 of the children showed increased HPLC levels of conjugated dienes, indicating increased levels of oxidation of in vivo blood lipids in children from the contaminated areas. The levels were higher in girls than in boys. Some 57 boys and 42 girls were given a basal diet with a diurnal supplementation of 40 mg natural 9-cis and all-trans equal isomer mixture {beta}-carotene in a capsulated powder form of the alga Dunaliella bardawil, for a period of 3 months. Blood serum analyses were regularly conducted before supplementation to determine the baseline effect of radiation exposure to the children, after 1 and 3 months of natural {beta}-carotene supplementation. After supplementation, the levels of the oxidized conjugated dienes decreased in the children`s sera without any significant changes in the level of total carotenoids, retinol or {alpha}-tocopherol. Other common blood biochemicals were within the normal range for all tests and no statistical differences before or after supplementation of {beta}-carotene were noted. High pressure liquid chromatography (HPLC) analyses for carotenoids in the blood detected mainly oxycarotenoids, and to a lesser extent, all-trans {beta}-carotene, {alpha}-carotene, but not 9-cis {beta}-carotene. The results suggest that irradiation increases the susceptibility of lipids to oxidation in the Chernobyl children and that natural {beta

  10. Effects of amines on particle growth observed in new particle formation events

    Science.gov (United States)

    Tao, Ye; Ye, Xingnan; Jiang, Shuqing; Yang, Xin; Chen, Jianmin; Xie, Yuanyuan; Wang, Ruyu

    2016-01-01

    Particle size distributions in the range of 0.01-10 µm were measured in urban Shanghai in the summer of 2013 using a Wide-range Particle Spectrometer (WPS). Size-segregated aerosol samples were collected concurrently using a Micro-Orifice Uniform Deposit Impactor (MOUDI), which aided our in-depth understanding of the new particle formation (NPF) mechanism in the polluted Yangtze River Delta area. During the observations, 16 NPF events occurred at high temperatures (~34.7°C) on clear and sunny days. In the ammonium-poor PM1.0 (particulate matter less than 1.0 µm), sulfate and ammonium accounted for 92% of the total water-soluble inorganic species. Six aminiums were detected in these MOUDI samples, among which the group of diethylaminium and trimethylaminium (DEAH+ + TMAH+) was the most abundant. The very high level of aminiums (average concentration up to 86.4 ng m-3 in PM1.8), together with highly acidic aerosols, provided insight into the frequent NPF events. The high mass ratio of total aminiums to NH4+ (>0.2 for PM0.056) further highlighted the important role of amines in promoting NPF. The concentration of DEAH+ + TMAH+ in new particles below 180 nm was strongly correlated with aerosol phase acidity, indicating that acid-base reactions dominated the aminium formation in NPF events. The unexpected enhancement of DEAH+ + TMAH+ on a nonevent day was attributed to the transportation of an SO2 plume. Our results reveal that the heterogeneous uptake of amines is dominated by the acid-base reaction mechanism, which can effectively contribute to particle growth in NPF events.

  11. Interaction between corticosteroid and beta-agonist drugs. Biochemical and cardiovascular effects in normal subjects.

    Science.gov (United States)

    Taylor, D R; Wilkins, G T; Herbison, G P; Flannery, E M

    1992-08-01

    The aim of this study was to investigate whether the administration of prednisone potentiates any of the acute biochemical and cardiovascular effects of high-dose inhaled beta-agonist drugs. These agents are known to cause dose-related changes in plasma potassium and glucose, as well as ECG changes in heart rate, corrected QT interval (QTc), T wave, and U wave. On theoretical grounds, the concomitant use of systemic corticosteroids might enhance these actions. Twenty-four healthy subjects were randomized to receive one of three treatments: salbutamol 5 mg or fenoterol 5 mg or normal saline solution. Each drug was administered twice, 30 min apart by nebulizer, and the procedure was repeated after each subject had received prednisone 30 mg daily for one week. Plasma potassium and glucose levels were measured, and ECGs were obtained after each treatment, together with 12-h Holter monitoring for arrhythmias. Changes in plasma potassium and glucose following nebulized beta-agonist were significantly greater after treatment with prednisone. Baseline potassium level fell from 3.75 mmol/L (95 percent CI 3.61, 3.89) to 3.50 mmol/L (95 percent CI 3.36, 3.64), and thereafter all values were significantly lower at each time point (p = 0.003). The lowest mean plasma potassium was obtained 90 min after fenoterol administration with prednisone pretreatment: 2.78 mmol/L (95 percent CI 2.44, 3.13). Increases in heart rate and QTc interval following both beta-agonist drugs were significant, but T-wave amplitude reductions did not reach significance. Prednisone treatment did not significantly alter the cardiovascular responses. Supraventricular and ventricular ectopic activity was related to beta-agonist use, but no potentiating effect was noted following steroid treatment. We conclude that the acute biochemical effects of beta-agonist administration are augmented by prior treatment with prednisone, but this is not the case for ECG effects. However, the degree of hypokalemia noted as

  12. Understanding particle size and distance driven competition of interparticle interactions and effective single-particle anisotropy.

    Science.gov (United States)

    Pacakova, B; Mantlikova, A; Niznansky, D; Kubickova, S; Vejpravova, J

    2016-05-25

    Magnetic response of single-domain nanoparticles (NPs) in concentrated systems is strongly affected by mutual interparticle interactions. However, particle proximity significantly influences single-particle effective anisotropy. To solve which of these two phenomena plays a dominant role in the magnetic response of real NP systems, systematic study on samples with well-defined parameters is required. In our work, we prepared a series of nanocomposites constituted of highly-crystalline and well-isolated CoFe2O4 NPs embedded in an amorphous SiO2 matrix using a single-molecule precursor method. This preparation method enabled us to reach a wide interval of particle size and concentration. We observed that the characteristic parameters of the single-domain state (coercivity, blocking temperature) and dipole-dipole interaction energy ([Formula: see text]) scaled with each other and increased with increasing [Formula: see text], where d XRD was the NP diameter and r was the interparticle distance. Our results are in excellent agreement with Monte-Carlo simulations of the particle growth. Moreover, we demonstrated that the contribution of [Formula: see text] acting as an additional energetic barrier to the superspin reversal or as an average static field did not sufficiently explain how the concentrated NP systems responded to an external magnetic field. Alternations in the blocking temperature and coercivity of our NP systems accounted for reformed relaxations of the NP superspins and modified effective anisotropy energy of the interacting NPs. Therefore, the concept of modified NP effective anisotropy explains the magnetic response of our concentrated NP systems better than the concept of the energy barrier influenced by interparticle interactions.

  13. [Antihypertensive effect of arotinolol (S-596), a new adrenergic beta blocking agent, on experimental hypertension].

    Science.gov (United States)

    Hara, Y; Nakahara, H; Miyagishi, A; Nakatani, H

    1983-08-01

    Effects of a new adrenergic beta-blocking agent, arotinolol (S-596), on the blood pressure and heart rate were assessed in comparison with those of other beta-blocking agents in deoxycorticosterone acetate (DOCA)-saline induced and spontaneously hypertensive rats (SHR). The relationship between the antihypertensive effect and the beta- or alpha-adrenoceptor blocking action of S-596 was also investigated in normotensive conscious rats. In the rat, a cannula was implanted chronically in a femoral artery, from which blood pressure was recorded. The test drugs were administered orally once a day for 14 days at several dose levels. The development of hypertension in DOCA-saline treated rats was clearly retarded with the consecutive oral administration of propranolol (100 mg/kg/day) and hydrochlorothiazide (10 mg/kg/day), but not with S-596 (20, 50 and 100 mg/kg/day) or pindolol (10 mg/kg/day). On the other hand, in SHR, S-596 (more than 10 mg/kg/day) propranolol (50 mg/kg/day), pindolol (10 mg/kg/day), labetalol (100 mg/kg/day) and hydrochlorothiazide (10 mg/kg/day) produced definite antihypertensive effects after the chronic administration. In normotensive conscious rats, the vasodepressor responses induced by isoproterenol were reduced by the beta-blocking agents at lower dose levels than those required for development of antihypertensive effects. The acute effects on blood pressure were determined in hypertensive rats during the chronic treatment with the test drugs. In either type of hypertension, S-596, (10-50 mg/kg/day) showed a depressor effect at 4 and/or 8 hr after administration. In normotensive conscious rats, S-596 antagonized the pressor responses to phenylephrine at doses more than 30 mg/kg. It is therefore suggested that an adrenergic alpha-blocking property is at least partly involved in the hypotensive effect of S-596 as labetalol. In the experiment of acute effect in SHR, pindolol and labetalol showed prominent hypotensive effect after the 1st

  14. X particle effect for 6Li reaction rates calculations

    International Nuclear Information System (INIS)

    Kocak, G.; Balantekin, A. B.

    2009-01-01

    The inferred primordial 6 L i-7 L i abundances are different from standard big bang nucleosynthesis results, 6 L i is 1000 times larger and 7 L i is 3 times smaller than the big bang prediction. In big bang nucleosynthesis, negatively charged massive X particles a possible solution to explain this primordial Li abundances problem [1]. In this study, we consider only X particle effect for nuclear reactions to obtain S-factor and reaction rates for Li. All S-factors calculated within the Optical Model framework for d(α,γ)6 L i system. We showed that the enhancement effect of massive negatively charged X particle for 6 L i system reaction rate.(author)

  15. Particle size effects on protein and virus-like particle adsorption on perfusion chromatography media.

    Science.gov (United States)

    Wu, Yige; Abraham, Dicky; Carta, Giorgio

    2015-01-02

    The resin structure, chromatographic behavior, and adsorption kinetics of proteins and virus-like-particles (VLPs) are studied for POROS HS 20 and POROS HS 50 (23 and 52 μm mean diameter, respectively) to determine the effects of particle size on perfusion chromatography and to determine the predictive ability of available models. Transmission electron microscopy (TEM) and inverse size-exclusion chromatography (iSEC) show similar structures for the two resins, both containing 200-1000 nm pores that transect a network of much smaller pores. For non-binding conditions, trends of the height equivalent to a theoretical plate (HETP) as a function of reduced velocity are consistent with perfusion. The estimated intraparticle flow fractions for these conditions are 0.0018 and 0.00063 for POROS HS 20 and HS 50, respectively. For strong binding conditions, confocal laser scanning microscopy (CLSM) shows asymmetrical intraparticle concentrations profiles and enhanced rates of IgG adsorption on POROS HS 20 at 1000 cm/h. The corresponding effective diffusivity under flow is 2-3 times larger than for non-flow conditions and much larger than observed for POROS HS 50, consistent with available models. For VLPs, however, adsorption is confined to a thin layer near the particle surface for both resins, suggesting that the bound VLPs block the pores. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Differential effects of ongoing EEG beta and theta power on memory formation.

    Science.gov (United States)

    Scholz, Sebastian; Schneider, Signe Luisa; Rose, Michael

    2017-01-01

    Recently, elevated ongoing pre-stimulus beta power (13-17 Hz) at encoding has been associated with subsequent memory formation for visual stimulus material. It is unclear whether this activity is merely specific to visual processing or whether it reflects a state facilitating general memory formation, independent of stimulus modality. To answer that question, the present study investigated the relationship between neural pre-stimulus oscillations and verbal memory formation in different sensory modalities. For that purpose, a within-subject design was employed to explore differences between successful and failed memory formation in the visual and auditory modality. Furthermore, associative memory was addressed by presenting the stimuli in combination with background images. Results revealed that similar EEG activity in the low beta frequency range (13-17 Hz) is associated with subsequent memory success, independent of stimulus modality. Elevated power prior to stimulus onset differentiated successful from failed memory formation. In contrast, differential effects between modalities were found in the theta band (3-7 Hz), with an increased oscillatory activity before the onset of later remembered visually presented words. In addition, pre-stimulus theta power dissociated between successful and failed encoding of associated context, independent of the stimulus modality of the item itself. We therefore suggest that increased ongoing low beta activity reflects a memory promoting state, which is likely to be moderated by modality-independent attentional or inhibitory processes, whereas high ongoing theta power is suggested as an indicator of the enhanced binding of incoming interlinked information.

  17. Differential effects of ongoing EEG beta and theta power on memory formation.

    Directory of Open Access Journals (Sweden)

    Sebastian Scholz

    Full Text Available Recently, elevated ongoing pre-stimulus beta power (13-17 Hz at encoding has been associated with subsequent memory formation for visual stimulus material. It is unclear whether this activity is merely specific to visual processing or whether it reflects a state facilitating general memory formation, independent of stimulus modality. To answer that question, the present study investigated the relationship between neural pre-stimulus oscillations and verbal memory formation in different sensory modalities. For that purpose, a within-subject design was employed to explore differences between successful and failed memory formation in the visual and auditory modality. Furthermore, associative memory was addressed by presenting the stimuli in combination with background images. Results revealed that similar EEG activity in the low beta frequency range (13-17 Hz is associated with subsequent memory success, independent of stimulus modality. Elevated power prior to stimulus onset differentiated successful from failed memory formation. In contrast, differential effects between modalities were found in the theta band (3-7 Hz, with an increased oscillatory activity before the onset of later remembered visually presented words. In addition, pre-stimulus theta power dissociated between successful and failed encoding of associated context, independent of the stimulus modality of the item itself. We therefore suggest that increased ongoing low beta activity reflects a memory promoting state, which is likely to be moderated by modality-independent attentional or inhibitory processes, whereas high ongoing theta power is suggested as an indicator of the enhanced binding of incoming interlinked information.

  18. Effect of 11 beta-hydroxysteroid dehydrogenase-1 inhibition on hepatic glucose metabolism in the conscious dog.

    Science.gov (United States)

    Edgerton, Dale S; Basu, Rita; Ramnanan, Christopher J; Farmer, Tiffany D; Neal, Doss; Scott, Melanie; Jacobson, Peer; Rizza, Robert A; Cherrington, Alan D

    2010-05-01

    Inactive cortisone is converted to active cortisol within the liver by 11 beta-hydroxysteroid dehydrogenase-1 (11 beta-HSD1), and impaired regulation of this process may be related to increased hepatic glucose production (HGP) in individuals with type 2 diabetes. The primary aim of this study was to investigate the effect of acute 11 beta-HSD1 inhibition on HGP and fat metabolism during insulin deficiency. Sixteen conscious, 42-h-fasted, lean, healthy dogs were studied. Somatostatin was infused to create insulin deficiency, and the animals were treated with a specific 11 beta-HSD1 inhibitor (compound 531) or placebo for 5 h. 11 beta-HSD1 inhibition completely suppressed hepatic cortisol production, and this attenuated the increase in HGP that occurred during insulin deficiency. PEPCK and glucose-6-phosphatase expression were decreased when 11 beta-HSD1 was inhibited, but gluconeogenic flux was unchanged, implying an effect on glycogenolysis. Since inhibition of hepatic cortisol production reduces HGP during insulin deficiency, 11 beta-HSD1 is a potential therapeutic target for the treatment of excess glucose production that occurs in diabetes.

  19. Toxicity, mutagenicity, and behavioral effects of {beta}-CIT, a ligand for dopamine transporter exploration by SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Emond, P.; Farde, L.; Chalon, S.; Belzung, C.; Mauclaire, V.; Chiron, J. P.; Halldin, C.; Besnard, J.C.; Guilloteau, D

    1998-05-01

    The cocaine analog {beta}-CIT is one of the most used compounds for SPET examination of the dopamine transporter in drug abuse and Parkinson's disease. However, the toxicity of this agent has not yet been studied. We report here acute toxicity, mutagenicity, and effect on locomotor activity of {beta}-CIT. Acute toxicity experiments were performed in mice and rats. The LD50 values were about 20 mg and 5 mg for mice and rats, respectively. There was no sex difference. The mutagenicity was evaluated using the Ames' test. No mutagenic effect was observed for {beta}-CIT. Effects on locomotor activity were measured in mice using the open-field test. {beta}-CIT increased locomotion (+65%) when injected at a dose of 0.312 mg/kg; the maximal increase (+205%) was observed at a dose of 1.25 mg/kg; at higher doses, the effect was decreased slightly. These pharmacological findings are in agreement with an inhibitory effect of {beta}-CIT at the dopamine transporter. We conclude that with no mutagenic effects and LD50 more than 6 orders of magnitude higher than the routinely used doses in PET or SPET, it can be assumed that {beta}-CIT can be safely used as a radioligand in humans.

  20. Effects of ocular surface strontium-90 beta radiotherapy in dogs latently infected with canine herpesvirus-1.

    Science.gov (United States)

    Nicklin, Amanda M; McEntee, Margaret C; Ledbetter, Eric C

    2014-12-05

    Latent canine herpesvirus-1 (CHV-1) infections are common in domestic dogs, but stimuli causing viral reactivation and recrudescent disease are poorly understood. Immunosuppressive pharmaceuticals are currently the only experimentally established triggers for recurrent ocular CHV-1 infection in dogs; however, ocular CHV-1 shedding has been reported clinically following strontium-90 beta radiotherapy of the ocular surface and it has been speculated that radiotherapy can directly induce viral reactivation. Strontium-90 is used as a beta radiation source for the treatment of a variety of neoplastic and immune-mediated canine ocular surface diseases. In the present study, the effects of ocular surface strontium-90 beta radiotherapy in dogs latently infected with CHV-1 were evaluated. Ten mature dogs with experimentally induced latent CHV-1 infections were randomly divided into two groups: one group received a single fraction 50 Gy radiation dose in one application from a strontium-90 ophthalmic applicator and the second group received sham radiotherapy. Dogs were then monitored for 45 days for recurrent ocular CHV-1 infection using clinical and virological outcome measures. Clinical ophthalmic examinations, ocular sample CHV-1 PCR assays, and serum CHV-1 virus neutralizing antibody assays were performed at specified intervals. No abnormalities suggestive of recurrent CHV-1 ocular disease were observed on clinical examination in any dog during the study. Ocular viral shedding was not detected and CHV-1 virus neutralizing titers remained stable in all dogs. A single fraction 50 Gy radiation dose administered to the ocular surface by strontium-90 beta radiotherapy did not result in detectable recurrent ocular CHV-1 infection in mature dogs with experimentally induced latent infection. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Effect of magnetic field on beta processes in a relativistic moderately degenerate plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ognev, I. S., E-mail: ognev@uniyar.ac.ru [Yaroslavl State University (Russian Federation)

    2016-10-15

    The effect of a magnetic field of arbitrary strength on the beta decay and crossing symmetric processes is analyzed. A covariant calculation technique is used to derive the expression for the squares of S-matrix elements of these reactions, which is also valid in reference frames in which the medium moves as a single whole along magnetic field lines. Simple analytic expressions obtained for the neutrino and antineutrino emissivities for a moderately degenerate plasma fully characterize the emissivity and absorbability of the studied medium. It is shown that the approximation used here is valid for core collapse supernovae and accretion disks around black holes; beta processes in these objects are predominantly neutrino reactions. The analytic expressions obtained for the emissivities can serve as a good approximation for describing the interaction of electron neutrinos and antineutrinos with the medium of the objects in question and hold for an arbitrary magnetic field strength. Due to their simplicity, these expressions can be included in the magnetohydrodynamic simulation of supernovae and accretion disks to calculate neutrino and antineutrino transport in them. The rates of beta processes and the energy and momentum emitted in them are calculated for an optically transparent matter. It is shown that the macroscopic momentum transferred in the medium increases linearly with the magnetic field strength and can substantially affect the dynamics of supernovae and accretion disks in the regions of a degenerate matter. It is also shown that the rates of beta processes and the energy emission for a magnetic field strength of B ≲ 10{sup 15} G typical of supernovae and accretion disks are lower than in the absence of field. This suppression is stronger for reactions with neutrinos.

  2. Effects of surface slope on erosion rates of quartz particles

    OpenAIRE

    Lodge, Phillip.

    2006-01-01

    Modeling sediment erosion is important in a wide range of environmental problems. The effects of various environmental factors on erosion rates have been studied, but the effects of surface slope on erosion rates of a wide range of sediments have not been quantified. The effects of surface slope, both in the direction of flow (pitch) and perpendicular to the flow (roll), on erosion rates of quartz particles were investigated using the Sediment Erosion at Depth Flume (Sedflume). US Navy (US...

  3. The bone regenerative effect of platelet-rich plasma in combination with an osteoconductive material in rat cranial defects.

    NARCIS (Netherlands)

    Plachokova, A.S.; Dolder, J. van den; Stoelinga, P.J.W.; Jansen, J.A.

    2006-01-01

    The effect of platelet-rich plasma (PRP) on bone regeneration, in combination with an osteoconductive material, was evaluated in a rat model. Cranial defects, 6.2 mm in diameter, were filled with HA/beta-TCP particles, HA/beta-TCP particles combined with PRP and HA/beta-TCP particles combined with

  4. CCN activation experiments with adipic acid: effect of particle phase and adipic acid coatings on soluble and insoluble particles

    Directory of Open Access Journals (Sweden)

    S. S. Hings

    2008-07-01

    Full Text Available Slightly soluble atmospherically relevant organic compounds may influence particle CCN activity and therefore cloud formation. Adipic acid is a frequently employed surrogate for such slightly soluble organic materials. The 11 published experimental studies on the CCN activity of adipic acid particles are not consistent with each other nor do they, in most cases, agree with the Köhler theory. The CCN activity of adipic acid aerosol particles was studied over a significantly wider range of conditions than in any previous single study. The work spans the conditions of the previous studies and also provides alternate methods for producing "wet" (deliquesced solution droplets and dry adipic acid particles without the need to produce them by atomization of aqueous solutions. The experiments suggest that the scatter in the previously published CCN measurements is most likely due to the difficulty of producing uncontaminated adipic acid particles by atomization of solutions and possibly also due to uncertainties in the calibration of the instruments. The CCN activation of the small (dm<150 nm initially dry particles is subject to a deliquescence barrier, while for the larger particles the activation follows the Köhler curve. Wet adipic acid particles follow the Köhler curve over the full range of particle diameters studied. In addition, the effect of adipic acid coatings on the CCN activity of both soluble and insoluble particles has also been studied. When a water-soluble core is coated by adipic acid, the CCN-hindering effect of particle phase is eliminated. An adipic acid coating on hydrophobic soot yields a CCN active particle. If the soot particle is relatively small (dcore≤102 nm, the CCN activity of the coated particles approaches the deliquescence line of adipic acid, suggesting that the total size of the particle determines CCN activation and the soot core acts as a scaffold.

  5. CCN activation experiments with adipic acid: effect of particle phase and adipic acid coatings on soluble and insoluble particles

    Science.gov (United States)

    Hings, S. S.; Wrobel, W. C.; Cross, E. S.; Worsnop, D. R.; Davidovits, P.; Onasch, T. B.

    2008-07-01

    Slightly soluble atmospherically relevant organic compounds may influence particle CCN activity and therefore cloud formation. Adipic acid is a frequently employed surrogate for such slightly soluble organic materials. The 11 published experimental studies on the CCN activity of adipic acid particles are not consistent with each other nor do they, in most cases, agree with the Köhler theory. The CCN activity of adipic acid aerosol particles was studied over a significantly wider range of conditions than in any previous single study. The work spans the conditions of the previous studies and also provides alternate methods for producing "wet" (deliquesced solution droplets) and dry adipic acid particles without the need to produce them by atomization of aqueous solutions. The experiments suggest that the scatter in the previously published CCN measurements is most likely due to the difficulty of producing uncontaminated adipic acid particles by atomization of solutions and possibly also due to uncertainties in the calibration of the instruments. The CCN activation of the small (dm<150 nm) initially dry particles is subject to a deliquescence barrier, while for the larger particles the activation follows the Köhler curve. Wet adipic acid particles follow the Köhler curve over the full range of particle diameters studied. In addition, the effect of adipic acid coatings on the CCN activity of both soluble and insoluble particles has also been studied. When a water-soluble core is coated by adipic acid, the CCN-hindering effect of particle phase is eliminated. An adipic acid coating on hydrophobic soot yields a CCN active particle. If the soot particle is relatively small (dcore≤102 nm), the CCN activity of the coated particles approaches the deliquescence line of adipic acid, suggesting that the total size of the particle determines CCN activation and the soot core acts as a scaffold.

  6. effect of limestone particle size on bone quality of layers

    African Journals Online (AJOL)

    UFS

    Peer-reviewed paper: 10th World Conference on Animal Production. 41. Effect of limestone particle size on bone quality characteristics of hens at end-of-lay. F.H. de Witt. #. , N.P. Kuleile .... 18 g), were obtained from a commercial egg producer and randomly allocated to the three treatments (n. = 23). At 70 weeks of age, ...

  7. Effect of Particle Acceleration Process on the Flare Characteristics of ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    J. Astrophys. Astr. (2002) 23, 95–99. Effect of Particle Acceleration Process on the Flare Characteristics of. Blazars. S. Bhattacharyya, S. Sahayanathan & C. L. Kaul Nuclear Research Laboratory,. Bhabha Atomic Research Centre, Mumbai 400 085, India. Abstract. Following the kinetic equation approach, we study the flare.

  8. Effects of particle size and surrounding media on optical radiation ...

    Indian Academy of Sciences (India)

    Abstract. The optical radiation efficiency (η), the ratio of scattering cross-section to extinction cross-section, of spherical metal nanoparticles (M = Al, Ag, Au and Cu) surrounded by glass and water was calculated using classical electrostatics. The effect of varying particle diameter (∼100 nm) on η was also studied for free ...

  9. Differential effect of adrenocorticosteroids on 11 beta-hydroxysteroid dehydrogenase bioactivity at the anterior pituitary and hypothalamus in rats.

    Science.gov (United States)

    Idrus, R B; Mohamad, N B; Morat, P B; Saim, A; Abdul Kadir, K B

    1996-08-01

    11 beta-Hydroxysteroid dehydrogenase (11 beta-OHSD) is a microsomal enzyme that catalyzes the dehydrogenation of cortisol (F) to cortisone (E) in man and corticosterone (B) to 11-dehydrocorticosterone (A) in rats. 11 beta-OHSD has been identified in a wide variety of tissues. The differential distribution of 11 beta-OHSD suggests that this enzyme has locally defined functions that vary from region to region. The aim of this study was to investigate the effects of the glucocorticoids B and dexamethasone (DM), the mineralocorticoid deoxycorticosterone (DOC), and the inhibitors of 11 beta-OHSD glycyrrhizic acid (Gl) and glycyrrhetinic acid (GE) on 11 beta-OHSD bioactivity at the hypothalamus (HT) and anterior pituitary (AP). Male Wistar rats were treated with GI or were adrenalectomized (ADX) and treated with either B, DM, or DOC for 7 days. All treatments were in vivo except GE, which was used in vitro. At the end of treatment, homogenates of HT and AP were assayed for 11 beta-OHSD bioactivity, expressed as the percentage conversion of B to A in the presence of NADP, 11 beta-OHSD bioactivity is significantly higher (P < 0.0001) in the AP compared with the HT. Adrenalectomy significantly increased the enzyme activity in the AP (P < 0.05), an effect reversed by B or DM. ADX rats treated with DOC showed decreased enzyme activity in the AP (P < 0.001) but increased the activity in the HT (P < 0.0001). Gl increased activity in both HT and AP, whereas GE decreased activity significantly. We conclude that the modulation of 11 beta-OHSD is both steroid specific and tissue specific.

  10. Granular Leidenfrost effect: experiment and theory of floating particle clusters.

    Science.gov (United States)

    Eshuis, Peter; van der Weele, Ko; van der Meer, Devaraj; Lohse, Detlef

    2005-12-16

    Granular material is vertically vibrated in a 2D container: above a critical shaking strength, and for a sufficient number of beads, a crystalline cluster is elevated and supported by a dilute gaseous layer of fast beads underneath. We call this phenomenon the granular Leidenfrost effect. The experimental observations are explained by a hydrodynamic model featuring three dimensionless control parameters: the energy input S, the number of particle layers F, and the inelasticity of the particle collisions epsilon. The (S,F) phase diagram, in which the Leidenfrost state lies between the purely solid and gas phases, shows accurate agreement between experiment and theory.

  11. Effect of beta-adrenergic blockade on elevated arterial compliance and low systemic vascular resistance in cirrhosis

    DEFF Research Database (Denmark)

    Møller, S; Bendtsen, F; Henriksen, Jens Henrik Sahl

    2001-01-01

    ) of 17.8 mmHg, and responded to beta-blocker treatment with a significant reduction in the HVPG (-16%; P beta-adrenergic blockade (1.27 versus 1.29 ml/mmHg, +2%, ns), whereas...... with beta-blockers, but the effect of this treatment on arterial compliance has not been investigated. The aim of the present study was therefore to assess the effects of propranolol on the arterial compliance of patients with cirrhosis. METHODS: Twenty patients with cirrhosis underwent a haemodynamic...... with beta-blockers increases small vessel (arteriolar) vascular tone towards the normal level, but does not affect the elevated compliance of the larger arteries in patients with cirrhosis....

  12. Multidimensional and memory effects on diffusion of a particle

    International Nuclear Information System (INIS)

    Bao, Jing-Dong

    2001-01-01

    The diffusion of an overdamped Brownian particle in the two-dimensional (2D) channel bounded periodically by a parabola is studied, where the particle is subject to an additive white or colored noise. The diffusion rate constant D * of the particle is evaluated by the quasi-2D approximation and the effective potential approach, and the theoretical result is compared with the Langevin simulation. The properties of the diffusion rate constant are stressed for weak and strong noise cases. It is shown that, in an entropy channel, the value of D * in units of Q decreases with increasing intensity of the colored noise. In the presence of energetic barriers, a nonmonotonic behavior of the reduced diffusion rate constant D * Q -1 as a function of the noise intensity is shown

  13. Hysteresis effects in the cores of particle accelerator magnets

    CERN Document Server

    AUTHOR|(CDS)2086181; Schoerling, Daniel

    A study of the hysteresis effects in the cores of particle accelerator magnets has been performed in the framework of the work presented in this thesis. This study has been focused on normal conducting particle accelerator magnets whose cores are manufactured using ferromagnetic materials. The magnetic circuits have been modelled using the developed models: one model for the magnetic circuit and one for the magnetization of the material in the core. The parameters of the magnetic circuit model have been identified with the help of simulations which rely on the finite element method (Opera 3D), while the parameters of the magnetic hysteresis model have been identified through experimental measurements performed using a method developed in the framework of this work. The modelling results have been validated by means of experimental measurements performed on two magnets: one small size magnet which has been specifically designed and manufactured, and one magnet which is currently used in a particle accelerator ...

  14. The effect of second-phase particles on the corrosion and struture of Zircaloy-4

    International Nuclear Information System (INIS)

    Cortie, M.B.

    1982-10-01

    The effect of heat treatment and second-phase particles on the corrosion resistance and microstructure of Zircaloy-4 has been examined. In particular the effect of precipitates on the rate and mechanism of high-temperature, high-pressure water or steam corrosion is discussed. Measurements of corrosion rate are presented for specimens which have received various heat treatments. The heat treatments studied included a fast cool from the beta field, prolonged annealing at temperatures ranging from 500 degrees Celsius to 1 100 degrees Celsius as well as combinations of the above. The fabrication of a small quantity of Zircaloy-4 strip was undertaken and the methods used and observations made are recorded. The wide range of microstructures produced in Zircaloy-4 by the heat treatments and fabrication procedures utilized are described and discussed with optical or electron microscope photographs showing the important features. Qualitative and semi-quantitative chemical analyses of the second-phase particles were carried out by both the scanning electron microscope and Auger spectroscopy. Evidence for the existence of a tin-rich precipitate in Zircaloy-4 is presented and discussed

  15. NOx Effects on Photochemical Aging of Urban Wet Particles

    Science.gov (United States)

    Lim, Y. B.; Seo, J.; Kim, J. Y.; Turpin, B. J.

    2017-12-01

    Aqueous chemistry in aerosol liquid water (ALW) has been considered an important pathway of particle formation, which is expected to improve current models; however, little is known about NOx effects on aqueous chemistry in wet urban particulate matter (PM). Here we show photochemical aging of wet aerosols at modest urban conditions conducted in a smog chamber and provide atmospheric evidence of these chamber reactions. At high relative humidity, HNO3, the main sink of photochemistry of NOx, initiates water uptake into aerosols and ALW in turn facilitates aqueous chemistry. The hygroscopic growth was significant, and aqueous chemistry led to mainly non-radical products, such as organonitrates and oligomers. This multiphase chemistry contributes to particle aging during a haze event in Seoul, a megacity in East Asia. PM2.5 at Seoul, a downwind site at high NOx conditions, and reference PM2.5 at Deokjeok Island, an upwind site that has no emission source, during winter including the haze period were analyzed. Chemical components of Seoul haze particles can be explained by photochemical aging of transported particles in the presence of NOx. East Asian megacities including Seoul suffer from high concentration particles, yet the formation is poorly understood. Our finding of chemical aging and secondary formation highlights the importance of multiphase reactions, including gas-phase photochemistry at high NOx and aqueous chemistry in ALW, which need to be incorporated into air quality models to improve predictions for public health.

  16. Effect of particle shape on capillary forces acting on particles at the air-water interface.

    Science.gov (United States)

    Chatterjee, Nirmalya; Flury, Markus

    2013-06-25

    The capillary forces exerted by moving air-water interfaces can dislodge particles from stationary surfaces. The magnitude of the capillary forces depends on particle shape, orientation, and surface properties, such as contact angle and roughness. The objective was to quantify, both experimentally and theoretically, capillary force variations as an air-water interface moves over the particles. We measured capillary forces as a function of position, i.e., force-position curves, on particles of different shape by using force tensiometry. The particles (5 mm nominal size) were made of polyacrylate and were fabricated using a 3D printer. Experimental measurements were compared with theoretical calculations. We found that force-position curves could be classified into in three categories according to particle shapes: (1) curves for particles with round cross sections, such as spheroidal particles, (2) curves for particles with fixed cross sections, such cylindrical or cubical particles, and (3) curves for particles with tapering cross sections, such as prismatic or tetrahedral particles. Spheroidal particles showed a continuously varying capillary force. Cylindrical or cubical particles showed pronounced pinning of the air-water interface line at edges. The pinning led to an increased capillary force, which was relaxed when the interface snapped off from the edges. Particles with tapering cross section did not show pinning and showed reduced capillary forces as the air-water interface line perimeter and displacement cross section continuously decrease when the air-water interface moved over the particles.

  17. Experimental Study on Effects of Particle Shape and Operating Conditions on Combustion Characteristics of Single Biomass Particles

    DEFF Research Database (Denmark)

    Momeni, M.; Yin, Chungen; Kær, Søren Knudsen

    2013-01-01

    An experimental study is performed to investigate the ignition, devolatilization, and burnout of single biomass particles of various shapes and sizes under process conditions that are similar to those in an industrial combustor. A chargecoupled device (CCD) camera is used to record the whole...... combustion process. For the particles with similar volume (mass), cylindrical particles are found to lose mass faster than spherical particles and the burnout time is shortened by increasing the particle aspect ratio (surface area). The conversion times of cylindrical particles with almost the same surface...... area/volume ratio are very close to each other. The ignition, devolatilization, and burnout times of cylindrical particles are also affected by the oxidizer temperature and oxygen concentration, in which the oxygen concentration is found to have a more pronounced effect on the conversion times at lower...

  18. Effects of Plyometric Training and Beta-Alanine Supplementation on Maximal-Intensity Exercise and Endurance in Female Soccer Players

    OpenAIRE

    Rosas, Fabi?n; Ram?rez-Campillo, Rodrigo; Mart?nez, Cristian; Caniuqueo, Alexis; Ca?as-Jamet, Rodrigo; McCrudden, Emma; Meylan, Cesar; Moran, Jason; Nakamura, F?bio Y.; Pereira, Lucas A.; Loturco, Irineu; Diaz, Daniela; Izquierdo, Mikel

    2017-01-01

    Abstract Plyometric training and beta-alanine supplementation are common among soccer players, although its combined use had never been tested. Therefore, a randomized, double-blind, placebo-controlled trial was conducted to compare the effects of a plyometric training program, with or without beta-alanine supplementation, on maximal-intensity and endurance performance in female soccer players during an in-season training period. Athletes (23.7 ? 2.4 years) were assigned to either a plyometri...

  19. Effect of fluid and particle inertia on the rotation of an oblate spheroidal particle suspended in linear shear flow

    Science.gov (United States)

    Rosén, T.; Do-Quang, M.; Aidun, C. K.; Lundell, F.

    2015-05-01

    This work describes the inertial effects on the rotational behavior of an oblate spheroidal particle confined between two parallel opposite moving walls, which generate a linear shear flow. Numerical results are obtained using the lattice Boltzmann method with an external boundary force. The rotation of the particle depends on the particle Reynolds number, Rep=G d2ν-1 (G is the shear rate, d is the particle diameter, ν is the kinematic viscosity), and the Stokes number, St =α Rep (α is the solid-to-fluid density ratio), which are dimensionless quantities connected to fluid and particle inertia, respectively. The results show that two inertial effects give rise to different stable rotational states. For a neutrally buoyant particle (St =Rep ) at low Rep, particle inertia was found to dominate, eventually leading to a rotation about the particle's symmetry axis. The symmetry axis is in this case parallel to the vorticity direction; a rotational state called log-rolling. At high Rep, fluid inertia will dominate and the particle will remain in a steady state, where the particle symmetry axis is perpendicular to the vorticity direction and has a constant angle ϕc to the flow direction. The sequence of transitions between these dynamical states were found to be dependent on density ratio α , particle aspect ratio rp, and domain size. More specifically, the present study reveals that an inclined rolling state (particle rotates around its symmetry axis, which is not aligned in the vorticity direction) appears through a pitchfork bifurcation due to the influence of periodic boundary conditions when simulated in a small domain. Furthermore, it is also found that a tumbling motion, where the particle symmetry axis rotates in the flow-gradient plane, can be a stable motion for particles with high rp and low α .

  20. Effect of fluid and particle inertia on the rotation of an oblate spheroidal particle suspended in linear shear flow.

    Science.gov (United States)

    Rosén, T; Do-Quang, M; Aidun, C K; Lundell, F

    2015-05-01

    This work describes the inertial effects on the rotational behavior of an oblate spheroidal particle confined between two parallel opposite moving walls, which generate a linear shear flow. Numerical results are obtained using the lattice Boltzmann method with an external boundary force. The rotation of the particle depends on the particle Reynolds number, Re(p)=Gd(2)ν(-1) (G is the shear rate, d is the particle diameter, ν is the kinematic viscosity), and the Stokes number, St=αRe(p) (α is the solid-to-fluid density ratio), which are dimensionless quantities connected to fluid and particle inertia, respectively. The results show that two inertial effects give rise to different stable rotational states. For a neutrally buoyant particle (St=Re(p)) at low Re(p), particle inertia was found to dominate, eventually leading to a rotation about the particle's symmetry axis. The symmetry axis is in this case parallel to the vorticity direction; a rotational state called log-rolling. At high Re(p), fluid inertia will dominate and the particle will remain in a steady state, where the particle symmetry axis is perpendicular to the vorticity direction and has a constant angle ϕ(c) to the flow direction. The sequence of transitions between these dynamical states were found to be dependent on density ratio α, particle aspect ratio r(p), and domain size. More specifically, the present study reveals that an inclined rolling state (particle rotates around its symmetry axis, which is not aligned in the vorticity direction) appears through a pitchfork bifurcation due to the influence of periodic boundary conditions when simulated in a small domain. Furthermore, it is also found that a tumbling motion, where the particle symmetry axis rotates in the flow-gradient plane, can be a stable motion for particles with high r(p) and low α.

  1. Taking account of the recoil effect under a light particle scattering on two heavy particles

    International Nuclear Information System (INIS)

    Peresypkin, V.V.

    1978-01-01

    Proceeding from the Faddeev equations the derivation of the Bruekner formula describing a light particle scattering by a system of two fixed force centers is presented. Using the zero-range two-particle potential and assuming the ratio of the incident particle mass to the heavy particle mass to be a small perturbation parameter the correction to the Bruekner formula is obtained taking into account the heavy particle recoil

  2. Fast Sausage Modes in Magnetic Tubes with Continuous Transverse Profiles: Effects of a Finite Plasma Beta

    Science.gov (United States)

    Chen, Shao-Xia; Li, Bo; Xiong, Ming; Yu, Hui; Guo, Ming-Zhe

    2016-12-01

    While standing fast sausage modes in flare loops are often invoked to interpret quasi-periodic pulsations (QPPs) in solar flares, it is unclear as to how they are influenced by the combined effects of a continuous transverse structuring and a finite internal plasma beta ({β }{{I}}). We derive a generic dispersion relation governing linear sausage waves in straight magnetic tubes for which plasma pressure is not negligible, and the density and temperature inhomogeneities of essentially arbitrary form take place in a layer of arbitrary width. Focusing on fast modes, we find that {β }{{I}} only weakly influences {k}{{c}}, the critical longitudinal wavenumber separating the leaky from trapped modes. Likewise, for both trapped and leaky modes, the periods P in units of the transverse fast time depend only weakly on {β }{{I}}, which is compatible with the fact that the effective wave vectors of fast sausage modes are largely perpendicular to the background magnetic field. However, a weak {β }{{I}} dependence of the damping times τ is seen only when the length-to-radius ratio L/R is ˜50% larger than some critical value π /({k}{{c}}R), which itself rather sensitively depends on the density contrast, profile steepness, as well as on how the transverse structuring is described. In the context of QPPs, we conclude that the much simpler zero-beta theory can be employed for trapped modes, as long as one sees the deduced internal Alfvén speed as actually being the fast speed. In contrast, effects due to a finite beta in flare loops should be considered when leaky modes are exploited.

  3. Three-particle effects observed in two-particle correlation measurements

    International Nuclear Information System (INIS)

    Pochodzalla, J.; Friedman, W.A.; Gelbke, C.K.; Lynch, W.G.; Maier, M.; Bizard, G.; Lefebvres, F.; Tamain, B.; Quebert, J.

    1985-01-01

    Correlations between coincident alpha particles and protons were measured for 40 Ar induced reactions on 197 Au at E/A=60 MeV. The correlation function exhibits features not expected from free α-p interactions. These include a pronounced maximum at low relative momenta, qapprox.=15 MeV/c, and a dependence of the 5 Li ground state peak on the total 5 Li energy and decay kinematics. These anomalies are explained by considering the contribution of the decay of 9 B, and the effects of the Coulomb field, due to the reaction residue, on the decay of 5 Li. (orig.)

  4. Three-particle effects observed in two-particle correlation measurements. [60 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Pochodzalla, J.; Friedman, W.A.; Gelbke, C.K.; Lynch, W.G.; Maier, M.; Ardouin, D.; Delagrange, H.; Doubre, H.; Gregoire, C.; Kyanowski, A.; Mittig, W.; Peghaire, A.; Peter, J.; Saint-Laurent, F.; Viyogi, Y.P.; Zwieglinski, B.; Bizard, G.; Lefebvres, F.; Tamain, B.; Quebert, J.

    1985-10-31

    Correlations between coincident alpha particles and protons were measured for UAr induced reactions on ZXAu at E/A=60 MeV. The correlation function exhibits features not expected from free -p interactions. These include a pronounced maximum at low relative momenta, qapprox.=15 MeV/c, and a dependence of the VLi ground state peak on the total VLi energy and decay kinematics. These anomalies are explained by considering the contribution of the decay of ZB, and the effects of the Coulomb field, due to the reaction residue, on the decay of VLi. (orig.).

  5. Ventricular electrical instability in the conscious dog: effects of psychologic stress and beta adrenergic blockade.

    Science.gov (United States)

    Matta, R J; Lawler, J E; Lown, B

    1976-11-04

    The effect of psychologic stress on cardiac vulnerability was examined in 10 conscious dogs. The repetitive extrasystole threshold was employed as a measure of susceptibility to ventricular fibrillation. Instrumental aversive conditioning constituted a stressful environment. The repetitive extrasystole threshold decreased by nearly 50 percent during 3 days in which the animals were exposed to the stressful environment. When Tolamolol hydrochloride, a cardioselective beta adrenoceptor blocking agent, was administered before a stress session, the repetitive extrasystole threshold was unaltered from the control value. Thus, stress-evoked changes in cardiac vulnerability are mediated through the sympathetic nervous system.

  6. Effects of Alkali and Counter Ions in Sn-Beta Catalyzed Carbohydrate Conversion

    DEFF Research Database (Denmark)

    Elliot, Samuel G.; Tolborg, Søren; Madsen, Robert

    2018-01-01

    and are herein addressed experimentally through kinetic experiments and isotope tracking. Alkali ions have a differential effect in competing reaction pathways: they promote the rate of carbon-carbon bond breakage of carbohydrate substrates, but decrease the rates of competing dehydration pathways. Further......Alkali ions have been shown to strongly influence the catalytic behavior of stannosilicates in the conversion of carbohydrates. An effect of having alkali ions present is a pronounced increase in selectivity towards methyl lactate. Mechanistic details of this effect have remained obscure...... addition of alkali inhibits activity of Sn-Beta in all major reaction pathways. The alkali effects on product distributions and on rates of product formation are similar, thus pointing to a kinetic reaction control and to irreversible reaction steps in the main pathways. Additionally, an effect...

  7. Effect of beta-adrenergic antagonists on bioluminescence control in three species of brittlestars (Echinodermata: Ophiuroidea).

    Science.gov (United States)

    Dupont, S; Mallefet, J; Vanderlinden, C

    2004-05-01

    The role of adrenaline in the nervous control of bioluminescence in three brittlestar species, Amphiura filiformis, Amphipholis squamata, and Ophiopsila aranea, was assessed by testing two different beta-adrenergic antagonists (propranolol and labetalol) over a wide concentration range (10(-10)-10(-3)M). We compared the effects of analogues (active vs. inactive) of the same substance (L- and D-enantiomers of propranolol). Propranolol presented both specific and nonspecific effects: (i) nonspecific effects were observed at the higher concentrations tested (10(-4) and 10(-3)M) in all three species; (ii) specific effects were detected only at the lower concentrations tested (10(-6)-10(-5)M). In A. squamata, the involvement of adrenaline in the nervous control of luminescence is supported by propranolol and labetolol specific inhibition. The neuropharmacological implications of nonspecific effects, the involvement of adrenaline and the interspecific differences in the brittlestar nervous control of bioluminescence are discussed.

  8. Experimental and theoretical study of dielectrophoretic particle trapping in arrays of insulating structures: Effect of particle size and shape.

    Science.gov (United States)

    Saucedo-Espinosa, Mario A; Lapizco-Encinas, Blanca H

    2015-05-01

    Insulator-based dielectrophoresis (iDEP) employs insulating structures embedded in a microchannel to produce electric field gradients. This contribution presents a detailed analysis of the regions within an iDEP system where particles are likely to be retained due to dielectrophoretic trapping in a microchannel with an array of cylindrical insulating structures. The effects of particle size and shape on dielectrophoretic trapping were analyzed by employing 1 and 2 μm polystyrene particles and Escherichia coli cells. This research aims to study the mechanism behind dielectrophoretic trapping and develop a deeper understanding of iDEP systems. Mathematical modeling with COMSOL Multiphysics was employed to assess electrokinetic and dielectrophoretic particle velocities. Experiments were carried out to determine the location of dielectrophoretic barriers that block particle motion within an iDEP microchannel; this supported the estimation of a correction factor to match experiments and simulations. Particle velocities were predicted with the model, demonstrating how the different forces acting on the particles are in equilibrium when particle trapping occurs. The results showed that particle size and shape have a significant effect on the magnitude, location, and shape of the regions of dielectrophoretic trapping of particles, which are defined by DEP isovelocity lines and EK isovelocity lines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Effects of the quantum vacuum in particle physics and cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, Juri

    2014-11-26

    In this work we investigate numerous effects of virtual particles on processes relevant for particle physics and cosmology. A central question is, whether radiative spontaneous electroweak symmetry breaking can be combined with neutrino mass generation, we find that the answer is affirmative. We discuss the implication of the RSSB on the neutrino mass phenomenology and low-energy observables. Furthermore, by comparing the models to experimental data we find that several anomalies in the present observations favour particular scenarios over the pure Standard Model hypothesis. We are able to show, that the presence of sterile neutrinos with active-sterile mixing of order 10{sup -3} and masses in the TeV range leads to a reduced invisible decay width of the Z-boson and can bring the NuTeV observations in agreement with theoretical expectations. The models we discuss naturally incorporate long lived particles which can serve as dark matter candidates and we investigate this phenomenologically. We find that the combination of the requirements leads to interesting constraints on the model and parameter space. We find that loop induced electromagnetic moments for the neutral dark matter candidates, lead to interactions with charged particles. We use this and derive new constraints from existing XENON100 and LUX data. In addition we study how vacuum effects can backreact on a given geometry in electromagnetism and semiclassical gravity. We find that in the case of gravity the conformal set up plays a special role and indicate several ideas for further investigation of this topic.

  10. Effect of alpha particles on bacteriophage T4Br(+)

    International Nuclear Information System (INIS)

    Leonteva, G.A.; Akoev, I.G.; Grigorev, A.E.

    1983-01-01

    The effects of heavy particle radiation, which is believed to be responsible for the high relative biological effectiveness (RBE) of space hadrons, on bacteriophages are investigated. Dry film cultures of bacteriophage T4 were irradiated with 5.3 MeV Po-210 alpha particles to doses from 5 to 60 Gray, and compared with cultures irradiated by Co-60 gamma radiation. Examination of the exponential dose-response curves for bacteriophage survival indicates an RBE of 4.68 for the alpha particles. The r-mutation frequency per 10,000 surviving phages is found to peak at 7.1 at doses between 65 and 85 Gray for gamma radiation, however it declines steadily from a level of 10.2 per 10,000 survivors with increasing dose of alpha radiation. Comparison of the mutation frequencies at the same levels of lethality and the spectra of mutations produced by the two types of radiation indicates alpha and gamma radiation to differ as well in the mechanisms of mutation production. It is concluded that the observed high RBE of space hadrons cannot be explained by the presence of high-energy particles in the secondary radiation. 13 references

  11. Particle shape effects on the stress response of granular packings.

    Science.gov (United States)

    Athanassiadis, Athanasios G; Miskin, Marc Z; Kaplan, Paul; Rodenberg, Nicholas; Lee, Seung Hwan; Merritt, Jason; Brown, Eric; Amend, John; Lipson, Hod; Jaeger, Heinrich M

    2014-01-07

    We present measurements of the stress response of packings formed from a wide range of particle shapes. Besides spheres these include convex shapes such as the Platonic solids, truncated tetrahedra, and triangular bipyramids, as well as more complex, non-convex geometries such as hexapods with various arm lengths, dolos, and tetrahedral frames. All particles were 3D-printed in hard resin. Well-defined initial packing states were established through preconditioning by cyclic loading under given confinement pressure. Starting from such initial states, stress-strain relationships for axial compression were obtained at four different confining pressures for each particle type. While confining pressure has the largest overall effect on the mechanical response, we find that particle shape controls the details of the stress-strain curves and can be used to tune packing stiffness and yielding. By correlating the experimentally measured values for the effective Young's modulus under compression, yield stress and energy loss during cyclic loading, we identify trends among the various shapes that allow for designing a packing's aggregate behavior.

  12. POTENTIAL PATHOPHYSIOLOGICAL MECHANISMS OF ULTRAFINE PARTICLE TOXIC EFFECTS IN HUMANS

    Directory of Open Access Journals (Sweden)

    JASMINA JOVIĆ-STOŠIĆ

    2008-03-01

    Full Text Available Epidemiological and clinical studies suggested the association of the particulate matter ambient air pollution and the increased morbidity and mortality, mainly from respiratory and cardiovascular diseases. The size of particles has great influence on their toxicity, because it determines the site in the respiratory tract where they deposit. The most well established theory explaining the mechanisms behind the increased toxicity of ultrafine particles (UFP, < 0.1 µm is that it has to do with the increased surface area and/or the combination with the increased number of particles. Biological effects of UFP are also determined by their shape and chemical composition, so it is not possible to estimate their toxicity in a general way. General hypothesis suggested that exposure to inhaled particles induces pulmonary alveolar inflammation as a basic pathophysiological event, triggering release of various proinflammatory cytokines. Chronic inflammation is a very important underlying mechanism in the genesis of atherosclerosis and cardiovascular diseases. UFP can freely move through the circulation, but their effects on the secondary organs are not known yet, so more studies on recognizing toxicological endpoints of UFP are needed. Determination of UFP toxicity and the estimation of their internal and biologically active dose are necessary for the evidence based conclusions connecting air pollution by UFP and human diseases.

  13. Power output and efficiency of beta-emitting microspheres

    Science.gov (United States)

    Cheneler, David; Ward, Michael

    2015-01-01

    Current standard methods to calculate the dose of radiation emitted during medical applications by beta-minus emitting microspheres rely on an over-simplistic formalism. This formalism is a function of the average activity of the radioisotope used and the physiological dimensions of the patient only. It neglects the variation in energy of the emitted beta particle due to self-attenuation, or self-absorption, effects related to the finite size of the sphere. Here it is assumed the sphere is comprised of a pure radioisotope with beta particles being emitted isotropically throughout the material. The full initial possible kinetic energy distribution of a beta particle is taken into account as well as the energy losses due to scattering by other atoms in the microsphere and bremsstrahlung radiation. By combining Longmire's theory of the mean forward range of charged particles and the Rayleigh distribution to take into account the statistical nature of scattering and energy straggling, the linear attenuation, or self-absorption, coefficient for beta-emitting radioisotopes has been deduced. By analogy with gamma radiation transport in spheres, this result was used to calculate the rate of energy emitted by a beta-emitting microsphere and its efficiency. Comparisons to standard point dose kernel formulations generated using Monte Carlo data show the efficacy of the proposed method. Yttrium-90 is used as a specific example throughout, as a medically significant radioisotope, frequently used in radiation therapy for treating cancer.

  14. Gas interaction effects on lunar bonded particles and their implications

    International Nuclear Information System (INIS)

    Mukherjee, N.R.

    1976-01-01

    Some of the bonded particles of lunar soil samples separated upon exposure to reactive gases such as oxygen, water vapor, their mixtures, acids and bases have been studied. The bondings between particles susceptible to gas disruption seemed to be generally weak and appeared to have taken place via highly radiation-damaged layers at the particle surfaces. The amorphous layers with an average thickness of about 0.05 μm were produced by the solar wind exposure of about 2000 years. Therefore, the solar wind was responsible for the formation of these weak bondings and also probably responsible for disruption of these bondings. Apollo 11 and 12 landed in the equatorial region and about 1500 km apart. Thus, the solar wind effects on materials at these sites should have been about the same and the proportion of bonded particles separated by reactive gas exposure should also have been about the same; but the number of separations observed was about 2.7 (average) times greater in the Apollo 11 soil sample than in the Apollo 12 soil sample. This finding suggests that the number of weakly bonded particles and probably the solar-wind damaged amorphous layer particles at these sites was about in the same proportion. It is, therefore, considered that materials from certain depth (practically not exposed to the solar wind) of another site were transported and mixed during recent years (considerably less than 2000 years) with the original materials of the Apollo 12 site. This is consistent with the conclusions made by other investigators

  15. Utility of atropine in patients under beta-blocker effect during exercise stress echocardiography

    International Nuclear Information System (INIS)

    Munera, Ana G; Restrepo, Gustavo; Aristizabal, Dagnovar; Cubides, Carlos A

    2006-01-01

    The objective is to assess the usefulness of adding atropine 0.5 to 1.0 mg by intravenous injection during peak exercise in patients under beta-blocker effect that are subjected to exercise stress echocardiography. Population: exercise stress echocardiography was performed in 73 patients receiving beta-blocking agents with basal heart rate below 60 beats per minute (BPM). Two groups were established at random: group I (18 patients that did not receive atropine during maximal exercise) and group II (50 patients from whom 28 received 0.5 mg atropine IV 30 seconds to one minute before concluding the exercise and 22 patients who received 1.0 mg atropine IV 30 seconds to one minute before its conclusion). From a demographic point of view, there were no differences between the two groups. Mean age was 59 ± 10.8 years (57% male). Most of the patients received metoprolol (87%) and no significant statistical differences in relation with the doses were found in these two groups. At the end of the exercise, the patients had a mean heart rate of 84% from their maximal heart rate (MHR). The values post-exercise were 76% at 30 seconds, 68% at 60 sec., 62% at 90 sec., and 59% of the maximal heart rate at 120 sec. When comparing the percentage of the maximal heart rate achieved in maximal exercise and the one observed during the first 120 sec. after exercise, no statistically significant difference was observed between the two groups (p > 0.05). Conclusion: during the performance of stress exercise echocardiography, the administration of intravenous atropine was of no use for incrementing the peak heart rate post-exercise in patients with significant beta-blocker effect (basal heart rate < 60 BPM)

  16. Effect of chronic metoprolol and coronary occlusion (CO) on cardiac beta receptor density in cats

    Energy Technology Data Exchange (ETDEWEB)

    Lathers, C.M.; Spivey, W.H.; Levin, R.M.

    1986-03-05

    The effect of metoprolol (M) on beta receptor density (BRD) was examined. M (5 mg/kg, p.o., b.i.d.) was given for 2 and 8 wks prior to CO of the left anterior descending artery (LAD) at its origin. BRD, determined by binding of /sup 3/H-dihydroalprenol, was examined in the myocardium (LA = left atrium, RA = right atrium, LV1 = proximal LAD distribution, LV = 2 distal LAD distribution, LV3 = posterior left ventricle, RV = right ventricle, and S = septum. A 2 factor ANOVA followed by simple effect and Newman-Keuls post hoc tests revealed that M produced no effect in BRD in LA, RA, LV2, or S. M increased BRD in LV1, LV3, and RV after 2 wk when compared to no M. In addition, BRD in LV3 and RV were also greater at 2 wk than after 8 wk M. The data indicate that there are regional differences in the beta adrenergic receptor densities among the areas of the heart and within the left ventricle. Chronic dosing with M produced increased BRD in only some of the areas of the heart. These differences may be related to functional differences in the various areas of the heart after CO.

  17. Responsiveness of beta-escin-permeabilized rabbit gastric gland model: effects of functional peptide fragments.

    Science.gov (United States)

    Akagi, K; Nagao, T; Urushidani, T

    1999-09-01

    We established a beta-escin-permeabilized gland model with the use of rabbit isolated gastric glands. The glands retained an ability to secrete acid, monitored by [14C]aminopyrine accumulation, in response to cAMP, forskolin, and histamine. These responses were all inhibited by cAMP-dependent protein kinase inhibitory peptide. Myosin light-chain kinase inhibitory peptide also suppressed aminopyrine accumulation, whereas the inhibitory peptide of protein kinase C or that of calmodulin kinase II was without effect. Guanosine-5'-O-(3-thiotriphosphate) (GTPgammaS) abolished cAMP-stimulated acid secretion concomitantly, interfering with the redistribution of H+-K+-ATPase from tubulovesicles to the apical membrane. To identify the targets of GTPgammaS, effects of peptide fragments of certain GTP-binding proteins were examined. Although none of the peptides related to Rab proteins showed any effect, the inhibitory peptide of Arf protein inhibited cAMP-stimulated secretion. These results demonstrate that our new model, the beta-escin-permeabilized gland, allows the introduction of relatively large molecules, e.g., peptides, into the cell, and will be quite useful for analyzing signal transduction of parietal cell function.

  18. Effects of aerodynamic particle interaction in turbulent non-dilute particle-laden flow

    DEFF Research Database (Denmark)

    Salewski, Mirko; Fuchs, Laszlo

    2008-01-01

    Aerodynamic four-way coupling models are necessary to handle two-phase flows with a dispersed phase in regimes in which the particles are neither dilute enough to neglect particle interaction nor dense enough to bring the mixture to equilibrium. We include an aerodynamic particle interaction model...... levels in the flow then decrease. The impact of the stochastic particle description on the four-way coupling model is shown to be relatively small. If particles are also allowed to break up according to a wave breakup model, the particles become polydisperse. An ad hoc model for handling polydisperse...

  19. Protective effect of niacinamide on interleukin-1beta-induced annulus fibrosus type II collagen degeneration in vitro.

    Science.gov (United States)

    Duan, Deyu; Yang, Shuhua; Shao, Zengwu; Wang, Hong; Xiong, Xiaoqian

    2007-02-01

    The protective effect of niacinamide on interleukin-1beta (IL-1beta)-induced annulus fibrosus (AF) type II collagen degeneration in vitro and the mechanism were investigated. Chiba's intervertebral disc (IVD) culture models in rabbits were established and 48 IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups: normal control group, niacinamide-treated group, type II collagen degneration group (IL-1beta) and treatment group (niacinamide+IL-1beta). After culture for one week, AFs were collected for inducible nitric oxide synthase (iNOS), cysteine containing aspartate specific protease-3 (Caspase-3) and type II collagen immunohistochemical examination, and type II collagen reverse transcription polymerase chain reaction (RT-PCR). The results showed that rate of iNOS positive staining AF cells in the 4 groups was 17.6%, 10.9%, 73.9% and 19.3% respectively. The positive rate in treatment group was significantly lower than in the type II collagen degeneration group (Pniacinamide could effectively inhibit IL-1beta stimulated increase of iNOS and Caspase-3 in AF, and alleviate IL-1beta-caused destruction and synthesis inhibition of type II collagen. Niacinamide is of potential for clinical treatment of IVD degeneration.

  20. Detection of hard {beta} radiation in water using the Cerenkov effect; Detection des {beta} durs dans l'eau par effet Cerenkov

    Energy Technology Data Exchange (ETDEWEB)

    Turck, B. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-01-01

    The light emitted from a liquid during the passage of a particle of sufficiently high energy can be used to determine the contamination of water by {beta}-emitters. The detector based on this principle requires no special treatment of the water. Particular attention has been paid to the optical yield of the detector. However the excellent sensitivity to which this principle leads can only be attained if the background noise is considerably reduced. The electronics associated with detector make it possible to detect a contamination of 8 x 10{sup -8} {mu}c/cm{sup 3} of strontium-90 in water in about ten minutes. The apparatus presents the double advantage of having a high sensitivity and of being easy to use. Its characteristics make it possible for it to be used for the continuous control of water. (author) [French] La lumiere emise au sein d'un liquide au passage d'une particule suffisamment energetique peut permettre de determiner la contamination d'une eau en emetteurs {beta}. Le detecteur realise sur ce principe ne necessite aucun traitement special de l'eau. Un soin tout particulier a ete apporte a l'etude du rendement optique du detecteur. Cependant l'excellente sensibilite attachee au principe ne peut etre utilisee que si l'on reduit considerablement le bruit de fond. L'electronique associee au detecteur permet de reperer l'existence d'une contamination de 8 x 10{sup -8} {mu}c/cm{sup 3} de strontium-90 dans l'eau en un temps d'une dizaine de minutes. L'appareil presente l'avantage d'allier une grande sensibilite a la facilite d'emploi. Ses performances autorisent son utilisation au controle continu des eaux. (auteur)

  1. Infrared reflectance spectra: effects of particle size, provenance and preparation

    Science.gov (United States)

    Su, Yin-Fong; Myers, Tanya L.; Brauer, Carolyn S.; Blake, Thomas A.; Forland, Brenda M.; Szecsody, J. E.; Johnson, Timothy J.

    2014-10-01

    We have recently developed methods for making more accurate infrared total and diffuse directional - hemispherical reflectance measurements using an integrating sphere. We have found that reflectance spectra of solids, especially powders, are influenced by a number of factors including the sample preparation method, the particle size and morphology, as well as the sample origin. On a quantitative basis we have investigated some of these parameters and the effects they have on reflectance spectra, particularly in the longwave infrared. In the IR the spectral features may be observed as either maxima or minima: In general, upward-going peaks in the reflectance spectrum result from strong surface scattering, i.e. rays that are reflected from the surface without bulk penetration, whereas downward-going peaks are due to either absorption or volume scattering, i.e. rays that have penetrated or refracted into the sample interior and are not reflected. The light signals reflected from solids usually encompass all such effects, but with strong dependencies on particle size and preparation. This paper measures the reflectance spectra in the 1.3 - 16 micron range for various bulk materials that have a combination of strong and weak absorption bands in order to observe the effects on the spectral features: Bulk materials were ground with a mortar and pestle and sieved to separate the samples into various size fractions between 5 and 500 microns. The median particle size is demonstrated to have large effects on the reflectance spectra. For certain minerals we also observe significant spectral change depending on the geologic origin of the sample. All three such effects (particle size, preparation and provenance) result in substantial change in the reflectance spectra for solid materials; successful identification algorithms will require sufficient flexibility to account for these parameters.

  2. Effects of beta-carotene supplementation on chick growth, immune status and behaviour in the grey partridge, Perdix perdix.

    Science.gov (United States)

    Cucco, M; Guasco, B; Malacarne, G; Ottonelli, R

    2006-11-01

    Carotenoids are important for various functions during chick development. Since these pigments cannot be synthesized, they can be considered limited resources that the mother optimally allocates between herself and her offspring (maternal effect). Some studies have examined the effects of carotenoids on growth and immune function but little is known about their role in behaviour. In this study of the grey partridge, we conducted two supplementation experiments: (1) laying females were fed with beta-carotene enriched or impoverished diets; (2) chicks were fed directly with beta-carotene enriched or impoverished diets. We then evaluated the effects of this carotenoid on chick growth, immunocompetence and anti-predator behaviour (reactions to a raptor model). In the first experiment, the beta-carotene enriched diet given to mothers did not cause any difference in chick physiology. In the second experiment, beta-carotene supplementation of chicks had a significant beneficial effect on their growth and immune response, although their behavioural reactions did not differ in relation to the diet. Therefore, beta-carotene supplementation had beneficial effects on growth and immunocompetence only when directly supplied to chicks. The beneficial effect reported in other species for begging or pecking behaviours was not confirmed for the anti-predator behaviour of grey partridge chicks.

  3. Simple detection method of amyloid-beta peptide using p-FET with optical filtering layer and magnetic particle

    Science.gov (United States)

    Kim, Kwan-Soo; Kim, Chang-Beom; Song, Ki-Bong

    2013-05-01

    This article describes a novel method for detection of amyloid-β (Aβ) peptide that utilizes a photo-sensitive field-effect transistor (p-FET). According to a recent study, Aβ protein is known to play a central role in the pathogenesis of Alzheimer's disease (AD). Accordingly, we investigated the variation of photo current of the p-FET generated by the magnetic beads conjugated with Aβ peptides which are placed on the p-FET sensing areas. Additionally, in order to amplify the output signal, we used the lock-in amplifier (LIA) and confirmed the generating the photo current by a small incident light power under 100 μW. It means that it is possible to simply detect a certain protein using magnetic beads conjugated with Aβ peptide and fluorescent label located on the p-FET device. Therefore, in this paper, we suggest that our method could detect tiny amounts of Aβ peptide for early diagnosis of AD using the p-FET devices.

  4. Effect of Hypertriglyceridemia on Beta Cell Mass and Function in ApoC3 Transgenic Mice.

    Science.gov (United States)

    Liu, Yun-Zi; Cheng, Xiaoyun; Zhang, Ting; Lee, Sojin; Yamauchi, Jun; Xiao, Xiangwei; Gittes, George; Qu, Shen; Jiang, Chun-Lei; Dong, H Henry

    2016-07-08

    Hypertriglyceridemia results from increased production and decreased clearance of triglyceride-rich very low-density lipoproteins, a pathological condition that accounts for heightened risk of ischemic vascular diseases in obesity and type 2 diabetes. Despite its intimate association with insulin resistance, whether hypertriglyceridemia constitutes an independent risk for beta cell dysfunction in diabetes is unknown. Answering this fundamental question is stymied by the fact that hypertriglyceridemia is intertwined with hyperglycemia and insulin resistance in obese and diabetic subjects. To circumvent this limitation, we took advantage of apolipoprotein C3 (ApoC3)-transgenic mice, a model with genetic predisposition to hypertriglyceridemia. We showed that ApoC3-transgenic mice, as opposed to age/sex-matched wild-type littermates, develop hypertriglyceridemia with concomitant elevations in plasma cholesterol and non-esterified fatty acid levels. Anti-insulin and anti-glucagon dual immunohistochemistry in combination with morphometric analysis revealed that ApoC3-transgenic and wild-type littermates had similar beta cell and alpha cell masses as well as islet size and architecture. These effects correlated with similar amplitudes of glucose-stimulated insulin secretion and similar degrees of postprandial glucose excursion in ApoC3-transgenic versus wild-type littermates. Oil Red O histology did not visualize lipid infiltration into islets, correlating with the lack of ectopic triglyceride and cholesterol depositions in the pancreata of ApoC3-transgenic versus wild-type littermates. ApoC3-transgenic mice, despite persistent hypertriglyceridemia, maintained euglycemia under both fed and fasting conditions without manifestation of insulin resistance and fasting hyperinsulinemia. Thus, hypertriglyceridemia per se is not an independent risk factor for beta cell dysfunction in ApoC3 transgenic mice. © 2016 by The American Society for Biochemistry and Molecular Biology

  5. Characterization of the effects of adenosine 5'-[beta-thio]-diphosphate in rat liver.

    OpenAIRE

    Keppens, S.; Vandekerckhove, A.; De Wulf, H.

    1993-01-01

    1. In rat liver cells micromolar concentrations of adenosine 5'-[beta-thio]diphosphate (ADP beta S), activate glycogen phosphorylase by an adenosine 3':5'-cyclic monophosphate (cyclic AMP)- independent mechanism. 2. As with adenosine 5'-triphosphate (ATP), ADP beta S also inhibits the rise in cyclic AMP after glucagon. 3. Cytosolic Ca2+ measured in single cells is rapidly increased with a pattern similar for ADP beta S and for ATP. 4. At variance with ATP, ADP beta S hardly increases inositol...

  6. Quantitative assessment of the effects of beta-glucan consumption on serum lipid profile and glucose level in hypercholesterolemic subjects.

    Science.gov (United States)

    Zhu, X; Sun, X; Wang, M; Zhang, C; Cao, Y; Mo, G; Liang, J; Zhu, S

    2015-08-01

    A growing body of evidence suggests that beta-glucan derived from oats or barley can reduce cardiovascular disease risk through reductions in serum lipids. However, the effects of beta-glucan on lipid changes in hypercholesterolemic patient groups are inconsistent. The objective of this study was to identify and quantify the effect of beta-glucan, a marker of water-soluble fiber, on various lipid parameters and glucose level in hypercholesterolemic subjects. We performed a comprehensive literature search to identify the relevant randomized controlled trials (RCTs) that investigated the effects of beta-glucan consumption in hypercholesterolemic subjects. Mean differences (MDs) and 95% confidence intervals (CIs) were calculated for net changes in lipid concentrations by using fixed-effects or random-effects models according to heterogeneity. Publication bias, sensitivity analysis and subgroup analyses were also performed. Seventeen eligible RCTs with 916 subjects were included in the meta-analysis. The pooled result showed that beta-glucan consumption in hypercholesterolemic population significantly lowered the total cholesterol (TC) (MD, -0.26 mmol/L; 95% CI, -0.33 to -0.18; P consumption significantly decreased TC and LDL-cholesterol concentrations but did not affect TG, HDL-cholesterol, and glucose concentrations in hypercholesterolemic subjects. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. The attachment of colloidal particles to environmentally relevant surfaces and the effect of particle shape.

    Science.gov (United States)

    McNew, Coy P; Kananizadeh, Negin; Li, Yusong; LeBoeuf, Eugene J

    2017-02-01

    Despite the prevalence of nonspherical colloidal particles, the role of particle shape in the transport of colloids is largely understudied. This study investigates the attachment of colloidal particles onto environmentally relevant surfaces while varying particle shape and ionic strength. Using quartz crystal microbalance and atomic force microscopy measurements, the role of particle shape was elucidated and possible mechanisms discussed. The attachment of both spherical and stretched polystyrene colloidal particles onto a smooth alginate-coated silica surface showed qualitative agreement with DLVO theory. Attachment onto a Harpeth humic acid (HHA) surface, however, significantly deviated from DLVO theory due to its high surface heterogeneity and extended confirmation from the silica surface. This extended confirmation provided increased potential for spherical particle entanglement, while the enlarged major axis of the stretched particles hindered their ability to attach. As ionic strength increased, the HHA layer condensed and provided less potential for spherical particle entanglement and therefore the selectivity for spherical particle attachment vanished. The findings presented in this study suggest that colloidal particle shape may play a complex and important role in predicting the transport of colloidal particles, especially in the presence of natural organic matter-coated surfaces. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Transport of carbon ion test particles and hydrogen recycling in the plasma of the Columbia tokamak HBT'' (High Beta Tokamak)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jian-Hua.

    1990-01-01

    Carbon impurity ion transport is studied in the Columbia High Beta Tokamak (HBT), using a carbon tipped probe which is inserted into the plasma (n{sub e} {approx} 1 {minus} 5 {times} 10{sup 14} (cm{sup {minus}3}), T{sub e} {approx} 4 {minus} 10 (eV), B{sub t} {approx} 0.2 {minus} 0.4(T)). Carbon impurity light, mainly the strong lines of C{sub II}(4267A, emitted by the C{sup +} ions) and C{sub III} (4647A, emitted by the C{sup ++} ions), is formed by the ablation or sputtering of plasma ions and by the discharge of the carbon probe itself. The diffusion transport of the carbon ions is modeled by measuring the space-and-time dependent spectral light emission of the carbon ions with a collimated optical beam and photomultiplier. The point of emission can be observed in such a way as to sample regions along and transverse to the toroidal magnetic field. The carbon ion diffusion coefficients are obtained by fitting the data to a diffusion transport model. It is found that the diffusion of the carbon ions is classical'' and is controlled by the high collisionality of the HBT plasma; the diffusion is a two-dimensional problem and the expected dependence on the charge of the impurity ion is observed. The measurement of the spatial distribution of the H{sub {alpha}} emissivity was obtained by inverting the light signals from a 4-channel polychromator, the data were used to calculate the minor-radial influx, the density, and the recycling time of neutral hydrogen atoms or molecules. The calculation shows that the particle recycling time {tau}{sub p} is comparable with the plasma energy confinement time {tau}{sub E}; therefore, the recycling of the hot plasma ions with the cold neutrals from the walls is one of the main mechanisms for loss of plasma energy.

  9. Effect of pressure overload on cardioprotection of mitochondrial KATP channels and GSK-3beta: interaction with the MPT pore.

    Science.gov (United States)

    Mozaffari, Mahmood S; Schaffer, Stephen W

    2008-05-01

    The mitochondrial permeability transition (MPT) pore may serve as the end-effector of cardioprotective mechanisms, namely the mitochondrial K(ATP) channels and glycogen synthase kinase-3beta (GSK-3beta). We recently showed that augmented MPT pore induction contributes to pressure overload-induced exacerbation of infarct size. This study tests the hypotheses that (i) elevation in perfusion pressure attenuates cardioprotection associated with activation of mitochondrial KATP channels or inhibition of GSK-3beta and (ii) perfusion pressure modulates the regulation of the MPT pore by mitochondrial KATP channels and/or GSK-3beta. Langendorff-perfused hearts were subjected to a regional ischemia-reperfusion insult at a perfusion pressure of either 80 or 160 cm H2O. The perfusion medium contained no drug, diazoxide (80 micromol/l; mitochondrial KATP channel opener), lithium chloride (LiCl, 1 mmol/l; nonselective inhibitor of GSK-3beta), SB-216763 (3 micromol/l; selective inhibitor of GSK-3beta), cyclosporine A (0.2 micromol/l; inhibitor of MPT pore induction), glibenclamide (50 micromol/l; inhibitor of KATP channels), and the combination of cyclosporine A and glibenclamide or the combination of glibenclamide and LiCl. The increase in perfusion pressure in the absence of a drug caused larger infarcts, an effect associated with poorer recovery of function following ischemia reperfusion. Treatment with either diazoxide or cyclosporine A reduced infarct size at both perfusion pressures but in contrast to diazoxide, cyclosporine A was more protective at the higher pressure. On the other hand, LiCl and SB-216763 reduced infarct size at both pressures, with the effect more marked at the higher perfusion pressure. Glibenclamide did not affect infarct size but eliminated the cardioprotective effect of cyclosporine A while having no effect on LiCl-induced cardioprotection. Perfusion pressure primarily affects GSK-3beta-mediated regulation of MPT pore formation in the ischemic

  10. Effect of dust particle polarization on scattering processes in complex plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kodanova, S. K.; Ramazanov, T. S.; Bastykova, N. Kh.; Moldabekov, Zh. A. [Institute for Experimental and Theoretical Physics, Al-Farabi Kazakh National University, 71 Al-Farabi Str., 050040 Almaty (Kazakhstan)

    2015-06-15

    Screened interaction potentials in dusty plasmas taking into account the polarization of dust particles have been obtained. On the basis of screened potentials scattering processes for ion-dust particle and dust particle-dust particle pairs have been studied. In particular, the scattering cross section is considered. The scattering processes for which the dust grain polarization is unimportant have been found. The effect of zero angle dust particle-dust particle scattering is predicted.

  11. [Effect of sulfonation of polyethersulfone sheets on the adsorption of beta2-microglobulin].

    Science.gov (United States)

    Cheng, Liping; Sun, Shudong; Yue, Yilun; Huang, Jia; Mao, Huayi; Liang, Bo

    2005-06-01

    This study was performed to evaluate the adsorption of beta2-microglobulin(beta2 M) by blood dialysis membrane materials which are polyethersulfone (PES), sulfonated polyethersulfones, (PES-SO3Na-I and PES-SO3Na-I ) in vitro incubated in human serum and radiolabeled beta2M (125I-beta2 M) solution respectively. In these experiments, the materials were incubated in 125I-beta2 M solution and human serum at the appointed time ranging from 15 minutes to four hours at 37 degrees C, and then the amounts of 125I-beta2M and serum beta2M adsorbed by materials were measured by radioimmunoassay (RIA). In the 125I-beta2 M system, amounts of 125I-beta2M adsorbed by the materials decreased in sequence of PES-SO3 Na-II > PES-SO3Na-I > PES. In the serum system, amounts of beta2M adsorbed reached maximums at 30 minutes and the final adsorptions decreased in sequence of PES-SO3Na-II > PES-SO3Na-I > PES. Sulfonated PES removes beta2M more than PES does and the adsorption of beta2M increases with the increase in the degree of sulfonation. Its ability to remove significant amount of beta2M may result in less beta2M available for incorporation into amyloid. The use of PES-SO3Na membranes lessens the likelihood of dialysis-related amyloidosis (DRA) development, which remains a major source of morbidity for patients treated with long-term hemodialysis.

  12. Lack of effect of beta-cyclodextrin and its water-soluble derivatives on in vitro drug transport across rat intestinal epithelium.

    Science.gov (United States)

    Zheng, Ying; Zuo, Zhong; Chow, Albert H L

    2006-02-17

    The present study aimed to investigate whether beta-cyclodetxrin (beta-CD) and its water-soluble derivatives, hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and sulfobutyl ether beta-cyclodextrin (SBE-beta-CD), exert any effects on the permeation of two drug transport markers (propranolol and lucifer yellow) across rat intestinal epithelium. Rat ileum was stripped of its serosa and mounted inside an Ussing Chamber. Apparent permeability coefficients (P(app)) of the markers from the mucosal to serosal side of the tissue were determined at 37 degrees C in the presence and absence of the beta-cyclodextrins on the mucosal side. Potential difference (PD) was constantly monitored during each experiment to ensure maintenance of the viability and integrity of the tissue. Pre-incubation with 1% beta-CD, 1% HP-beta-CD or 1.48% SBE-beta-CD on the mucosal side for 30 min did not significantly alter the PD and the propranolol permeability (p>0.05). Co-incubation with 1% beta-CD or 1% HP-beta-CD exerted no significant effect on the P(app) of both propranolol and lucifer yellow (p>0.05), but co-incubation with 1.48% SBE-beta-CD lowered the P(app) of propranolol from (1.71+/-0.44)x10(-5) to (0.19+/-0.04)x10(-5)cm/s, which may be ascribed to the molecular complexation of propranolol with SBE-beta-CD. All three beta-cyclodextrins exert no apparent impact on both (passive) transcellar and paracellular drug transports.

  13. The magnitude and effects of extreme solar particle events

    Directory of Open Access Journals (Sweden)

    Jiggens Piers

    2014-06-01

    Full Text Available The solar energetic particle (SEP radiation environment is an important consideration for spacecraft design, spacecraft mission planning and human spaceflight. Herein is presented an investigation into the likely severity of effects of a very large Solar Particle Event (SPE on technology and humans in space. Fluences for SPEs derived using statistical models are compared to historical SPEs to verify their appropriateness for use in the analysis which follows. By combining environment tools with tools to model effects behind varying layers of spacecraft shielding it is possible to predict what impact a large SPE would be likely to have on a spacecraft in Near-Earth interplanetary space or geostationary Earth orbit. Also presented is a comparison of results generated using the traditional method of inputting the environment spectra, determined using a statistical model, into effects tools and a new method developed as part of the ESA SEPEM Project allowing for the creation of an effect time series on which statistics, previously applied to the flux data, can be run directly. The SPE environment spectra is determined and presented as energy integrated proton fluence (cm−2 as a function of particle energy (in MeV. This is input into the SHIELDOSE-2, MULASSIS, NIEL, GRAS and SEU effects tools to provide the output results. In the case of the new method for analysis, the flux time series is fed directly into the MULASSIS and GEMAT tools integrated into the SEPEM system. The output effect quantities include total ionising dose (in rads, non-ionising energy loss (MeV g−1, single event upsets (upsets/bit and the dose in humans compared to established limits for stochastic (or cancer-causing effects and tissue reactions (such as acute radiation sickness in humans given in grey-equivalent and sieverts respectively.

  14. Nuclear beta decay induced by intense electromagnetic fields: Basic theory

    International Nuclear Information System (INIS)

    Reiss, H.R.

    1983-01-01

    A basic formalism is developed for the theory of the effect on nuclear beta decay of an intense, plane-wave electromagnetic field. Interactions of the field with both the nuclear particles and the decay electron are included. The formalism is developed from first principles, including a derivation of transition probabilities between explicitly time-dependent asymptotic states. Interaction of the field with the nucleus is analyzed in terms of separation of the nucleus into an inert core and a fragment. The field interacts with the fragment, consisting of the nucleons which are candidates for beta decay, plus any other nucleons angular-momentum coupled to them in initial or final states. A separation of variables in the dynamical equations for the nucleus into center-of-mass and relative coordinates for the core and fragment shows direct charge coupling even for a fragment consisting entirely of neutrons. The transition formalism involves specific intense-field wave functions both for the nucleus and for the beta particle. Complete results are presented for total transition probability per unit time for intense-field-coupled nuclear beta decay. A much simplified formalism is given for the special case of very high field intensity at very low frequency. The results then bear a formal resemblance to ordinary beta decay theory, but they contain specific field effects in the beta particle spectral function, and in the nuclear interaction matrix elements. This is the first of a series of papers on this subject

  15. Dose-response effects of estrogenic mycotoxins (zearalenone, alpha- and beta-zearalenol) on motility, hyperactivation and the acrosome reaction of stallion sperm

    OpenAIRE

    Filannino, Angela; Stout, Tom AE; Gadella, Bart M; Sostaric, Edita; Pizzi, Flavia; Colenbrander, Ben; Dell'Aquila, Maria Elena; Minervini, Fiorenza

    2011-01-01

    Abstract Background The aim of this study was to investigate the in vitro effects of the Fusarium fungus-derived mycotoxin, zearalenone and its derivatives alpha-zearalenol and beta-zearalenol on motility parameters and the acrosome reaction of stallion sperm. Since the toxic effects of zearalenone and its derivatives are thought to result from their structural similarity to 17beta-estradiol, 17beta-estradiol was used as a positive control for 'estrogen-like' effects. Methods Stallion spermat...

  16. Influences of Substrate Adhesion and Particle Size on the Shape Memory Effect of Polystyrene Particles.

    Science.gov (United States)

    Cox, Lewis M; Killgore, Jason P; Li, Zhengwei; Long, Rong; Sanders, Aric W; Xiao, Jianliang; Ding, Yifu

    2016-04-19

    Formulations and applications of micro- and nanoscale polymer particles have proliferated rapidly in recent years, yet knowledge of their mechanical behavior has not grown accordingly. In this study, we examine the ways that compressive strain, substrate surface energy, and particle size influence the shape memory cycle of polystyrene particles. Using nanoimprint lithography, differently sized particles are programmed into highly deformed, temporary shapes in contact with substrates of differing surface energies. Atomic force microscopy is used to obtain in situ measurements of particle shape recovery kinetics, and scanning electron microscopy is employed to assess differences in the profiles of particles at the conclusion of the shape memory cycle. Finally, finite element models are used to investigate the growing impact of surface energies at smaller length scales. Results reveal that the influence of substrate adhesion on particle recovery is size-dependent and can become dominating at submicron length scales.

  17. Experimental studies of the early effects of inhaled beta-emitting radionuclides for nuclear accident risk assessment: Phase 2 report

    Energy Technology Data Exchange (ETDEWEB)

    Scott, B.R.; Hahn, F.F.; Newton, G.J.; Snipes, M.B.; Damon, E.G.; Mauderly, J.L.; Boecker, B.B.; Gray, D.H.

    1987-11-01

    This report summarizes a series of experiments concerning the effect of linear energy transfer and temporal radiation dose pattern to the lung from inhaled beta-emitting radionuclides. The results were used to test the validity of a hazard-function mathematical model for predicting death from radiation pneumonitis. Both morbidity and mortality within 18 months after exposure were examined in rats exposed to beta-emitting radionuclides, giving brief or protracted irradiation of the lung or having weak or strong beta emissions. Protraction of the radiation dose to the lung from a half-time in the lung of less than three days to a half-time with a long-term component of about 150 days has a sparing effect. The median lethal dose for the protracted irradiation is about 1.7 times the median lethal dose for the brief irradiation. Low energy beta emissions from /sup 147/Pm have a similar effectiveness in producing lethal injury as high energy beta emissions from /sup 90/Sr. Changes in three parameters of morbidity were measured: body weight, hematology and pulmonary function; only changes in pulmonary function correlated well with pulmonary radiation injury. The doses of radiation required to produce impaired function, however, were not significantly different from those that produced death. The hazard-function model for predicting death from radiation pneumonitis, which was developed from previously obtained data for inhalation exposures of dogs to beta-emitting radionuclides, adequately predicted the median lethal doses for rats receiving one of several different beta dose rate patterns to the lung, thus strengthening the validity of the mathematical model. 23 refs., 41 figs., 12 tabs.

  18. Zone II flexor tendon repair: effects of vitamins A, E, beta-carotene.

    Science.gov (United States)

    Greenwald, D P; Sharzer, L A; Padawer, J; Levenson, S M; Seifter, E

    1990-07-01

    Ninety-six adult Leghorn chickens each had the flexor profundus tendon in each middle toe sharply divided in Zone II with immediate repair (pentobarbital, ketamine anesthesia). Animals were then randomly assigned to receive unsupplemented standard chick chow or the chow supplemented with vitamin A (150,000 IU/kg chow), Vitamin E (1000 IU/kg chow), or beta-carotene (90 mg/kg chow). Eight animals from each of the four groups were examined at 7, 30, or 45 days post repair. After sacrifice, in situ composite wound breaking strength was measured in the amputated toe by constant speed tensiometry. Vitamin A-supplemented animals demonstrated breaking strength more than double that of control at each postoperative test day, while those animals receiving supplemental Vitamin E had breaking strength less than half that of control at Day 7 and Day 45. These results are statistically significant. Tensiometry curves differed markedly at all time points among the groups: Vitamin A curves being broader, higher, and having more spikes. These differences in the tensiometry curves, both qualitative and quantitative, may be due to differences in intrinsic tendon healing or to differences in adhesion formation or a combination of both. beta-Carotene supplementation had modest effect. We conclude that supplemental dietary vitamin A increases the breaking strength of composite tendon wounds and that supplemental dietary vitamin E decreases it.

  19. Effect of beta and gamma neurofeedback on memory and intelligence in the elderly.

    Science.gov (United States)

    Staufenbiel, S M; Brouwer, A-M; Keizer, A W; van Wouwe, N C

    2014-01-01

    Recent research showed a correlation between cognitive decline and a decrease of EEG gamma activity. In the present double-blind randomized control study, we investigated whether gamma and beta neurofeedback protocols, that have been shown to modulate performance on cognitive control and memory in young adults, also leads to increased brain activity and cognitive performance in elderly. Twenty older adults either performed eight 30-min gamma neurofeedback session or beta neurofeedback session within a period of 21 days. Cognitive performance was determined before and after the training through an IQ and memory task and we added a subjective well-being questionnaire. Both neurofeedback training protocols resulted in a significant increase of the brain activity within each training session, suggesting that the aging brain is still trainable. However, we found no effects on cognitive performance or transfer of the feedback beyond the trainings. We discuss several possible reasons for the lack of training on rest measurements and cognition and ways to improve the feedback protocols for future studies. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Beta radiation effects in sup 1 sup 3 sup 7 Cs-substituted pollucite

    CERN Document Server

    Hess, N J; Conradson, S D; Weber, W J

    2000-01-01

    The effect of high-energy beta radiation on the long-range and local structure of sup 1 sup 3 sup 7 Cs-substituted CsAlSi sub 2 O sub 6 (pollucite) was studied by X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) techniques at the Cs K-edge. Analysis of the XRD pattern of pollucite with an absorbed dose of 10 sup 1 sup 8 beta decays/g using Rietveld analysis indicates a 0.5-1% volume expansion of the tetrahedral structure as measured at 50 K and a minor displacement of the Cs cation toward the face of one of the six-membered rings. Analysis of the real-space pair-distribution function obtained from Fourier transformation of the diffraction pattern indicates significant correlated movement of the (Si,Al)-O pairs and large static disorder between Cs-O pairs. Analysis of the Cs K-edge XAS revealed substantial contributions from the Cs atomic X-ray absorption. This likely results from the exceedingly long Cs-O bond distances in the pollucite structure, which diminish the fine structure of the XAS os...

  1. Few active mechanisms of the neutrinoless double beta-decay and effective mass of Majorana neutrinos

    CERN Document Server

    Simkovic, Fedor; Faessler, Amand

    2010-01-01

    It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay (0nbb-decay). By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, assuming the observation of the 0nbb-decay in three different nuclei, e.g., 76Ge, 100Mo and 130Te, and just three lepton number violating mechanisms (light and heavy neutrino mass mechanisms as well as R-parity breaking SUSY mechanism) being active, there are only four different solutions for the lepton violating parameters, provided that they are relatively real. In particular, assuming evidence of the 0nbb-decay of 76Ge, the effective neutrino Majorana mass |m_bb| can be almost uniquely extracted by utilizing other existing constraints (cosmological observations and tritium beta-decay ex...

  2. Effect of Particle Size on Shear Stress of Magnetorheological Fluids

    OpenAIRE

    Chiranjit Sarkar; Harish Hirani

    2015-01-01

    Magnetorheological fluids (MRF), known for their variable shear stress contain magnetisable micrometer-sized particles (few micrometer to 200 micrometers) in a nonmagnetic carrier liquid. To avoid settling of particles, smaller sized (3-10 micrometers) particles are preferred, while larger sized particles can be used in MR brakes, MR clutches, etc. as mechanical stirring action in those mechanisms does not allow particles to settle down. Ideally larger sized particles provide higher shear str...

  3. Effects of Na and Ca on particle size; Effect of filtering on UV absorbance

    Data.gov (United States)

    U.S. Environmental Protection Agency — Effects of Na and Ca on particle size; Effect of filtering on UV absorbance. This dataset is associated with the following publication: Bouchard, D., C. Knightes, X....

  4. 3D Simulations of Space Charge Effects in Particle Beams

    International Nuclear Information System (INIS)

    Adelmann, A.

    2002-10-01

    For the first time, it is possible to calculate the complicated three-dimensional proton accelerator structures at the Paul Scherrer Institut (PSI). Under consideration are external and self effects, arising from guiding and space-charge forces. This thesis has as its theme the design, implementation and validation of a tracking program for charged particles in accelerator structures. This work form part of the discipline of Computational Science and Engineering (CSE), more specifically in computational accelerator modelling. The physical model is based on the collisionless Vlasov-Maxwell theory, justified by the low density (∼ 10 9 protons/cm 3 ) of the beam and of the residual gas. The probability of large angle scattering between the protons and the residual gas is then sufficiently low, as can be estimated by considering the mean free path and the total distance a particle travels in the accelerator structure. (author)

  5. Effect of hot α-particles on ion cyclotron absorption

    International Nuclear Information System (INIS)

    Cairns, R.A.; Kay, A.; Lashmore-Davies, C.N.

    1987-01-01

    Ion cyclotron heating involves mode conversion of the incident fast wave to a Bernstein mode, which is generally stongly damped and only propagates in a localized region of the plasma. The usual theoretical approach to this problem involves solution of fourth or higher order equations, but by treating the Bernstein mode as a driven response to the fast wave we obtain a simple second order equation. Comparison of its solutions with those of higher order equations shows that this approach gives good results. The same method can be used to consider the effect of a small population of hot α-particles on ion cyclotron heating, since it does away with the need for a small larmor radius expansion. The results indicate that a small concentration of α-particles can absorb a substantial fraction of the incident energy

  6. 3D Simulations of Space Charge Effects in Particle Beams

    Energy Technology Data Exchange (ETDEWEB)

    Adelmann, A

    2002-10-01

    For the first time, it is possible to calculate the complicated three-dimensional proton accelerator structures at the Paul Scherrer Institut (PSI). Under consideration are external and self effects, arising from guiding and space-charge forces. This thesis has as its theme the design, implementation and validation of a tracking program for charged particles in accelerator structures. This work form part of the discipline of Computational Science and Engineering (CSE), more specifically in computational accelerator modelling. The physical model is based on the collisionless Vlasov-Maxwell theory, justified by the low density ({approx} 10{sup 9} protons/cm{sup 3}) of the beam and of the residual gas. The probability of large angle scattering between the protons and the residual gas is then sufficiently low, as can be estimated by considering the mean free path and the total distance a particle travels in the accelerator structure. (author)

  7. The KCNE1 beta-subunit exerts a transient effect on the KCNQ1 K+ channel

    DEFF Research Database (Denmark)

    Poulsen, Asser Nyander; Klærke, Dan Arne

    2007-01-01

      The KCNE1 beta-subunit is a modulatory one-trans-membrane segment accessory protein that alters KCNQ1 K(+) channel current characteristics, though it is not required for channel expression. The KCNE1 and KCNQ1 interaction was investigated by looking for effects of expression time on channel...... currents in Xenopus laevis oocytes. We found that long-time expression of KCNQ1+KCNE1 (2-14 days) resulted in gradual changes in current characteristics resembling a disappearance of KCNE1 from the oocyte plasma membrane. Towards the end of the expression period the current of oocytes expressing KCNQ1+KCNE......1 was indistinguishable from those expressing KCNQ1 alone. No time dependent effect was seen in oocytes expressing KCNQ1 alone or a concatamer of KCNQ1 and KCNE1. Brefeldin A was tested, showing that measured current was independent of exocytosis (decreased capacitance) thus eliminating a continuous...

  8. ION EFFECTS IN THE APS PARTICLE ACCUMULATOR RING

    Energy Technology Data Exchange (ETDEWEB)

    Calvey, J.; Harkay, K.; Yao, CY.

    2017-06-25

    Trapped ions in the APS Particle Accumulator Ring (PAR) lead to a positive coherent tune shift in both planes, which increases along the PAR cycle as more ions accumulate. This effect has been studied using an ion simulation code developed at SLAC. After modifying the code to include a realistic vacuum profile, multiple ionization, and the effect of shaking the beam to measure the tune, the simulation agrees well with our measurements. This code has also been used to evaluate the possibility of ion instabilities at the high bunch charge needed for the APS-Upgrade.

  9. Cataractogenic effects of heavy charged particles in mice

    International Nuclear Information System (INIS)

    Ainsworth, E.J.; Jose, J.G.; Yang, V.V.; Barker, M.E.

    1980-01-01

    The effects of heavy charged particles on the crystalline lens of the eye of mice are important because this tissue has proven susceptible to other forms of high-LET radiation. This report summarizes the results currently available from a prospectively designed study to explore the LET dependence of the cataractogenic process. The present results are consistent with a high cataractogenic effect at 100 keV/μm, because plateau argon 40 ions, with an LET in this range, produce higher average cataracts scores at 9, 11 and 13 months than do carbon 12 or neon 20 ions. In the electron micrographs, significant changes were observed from the controls

  10. Comparison of the effects of inhaled {sup 239}PuO{sub 2} and {beta}- emitting radionuclides on the incidence of lung carcinomas in laboratory animals

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, F.F.; Griffith, W.C.; Boecker, B.B.; Muggenburg, B.A.; Lundgren, D.L.

    1991-12-31

    The health effects of inhaling radioactive particles when the lung is the primary organ irradiated were studied in rats and Beagle dogs. The animals were exposed to aerosols of {sup 239}PuO{sub 2} or fission-product radionuclides in insoluble forms and observed for their life span. Lung carcinomas were the primary late-occuring effect. The incidence rate for lung carcinomas was modeled using a proportional hazard rate model. Linear functions predominated below 5 Gy to the lung. The life-time risk for lung carcinomas per 10{sup 4} Gy for beta emitters was 60 for rats and 65 for dogs, and for {sup 239}PuO{sub 2} it was 1500 for rats and 2300 for dogs.

  11. Atomic effects of beta decay in astrophysics and in elementary particle physics

    International Nuclear Information System (INIS)

    Zonghua, Chen.

    1988-01-01

    The thesis consists mainly of two parts. The first part is a study of the bound-state β decay of 187 Re and its application in Astrophysics. There existed an uncertainty in the ratio ρ b of bound-state to continuum β decay of 187 Re in both theory and experiment. A more definite theoretical result of ρ b ∼ 1% is obtained by using single-configuration and multi-configuration Hartree-Fock-Dirac approximations. The results obtained are close to those obtained by Williams, Fowler, and Koonin by a modified Thomas-Fermi model. The bound-state β decay of 187 Re at high temperatures is also studied. The second part of the thesis is a generalization of the Thomas-Fermi results of various energy contribution to the ground-state energy of a neutral atom. An analytical expression for the ratio of the electron-electron to electron-nuclear interaction is obtained by the corrected Thomas-Fermi result, the ratio obtained gives a better agreement with the Hartree-Fock numerical results

  12. Effect of in vitro degradation of poly(D,L-lactide)/beta-tricalcium composite on its shape-memory properties.

    Science.gov (United States)

    Zheng, Xiaotong; Zhou, Shaobing; Yu, Xiongjun; Li, Xiaohong; Feng, Bo; Qu, Shuxin; Weng, Jie

    2008-07-01

    The in vitro degradation characteristic and shape-memory properties of poly(D,L-lactide) (PDLLA)/beta-tricalcium phosphate (beta-TCP) composites were investigated because of their wide application in biomedical fields. In this article, PDLLA and crystalline beta-TCP were compounded and interesting shape-memory behaviors of the composite were first investigated. Then, in vitro degradation of the PDLLA/beta-TCP composites with weight ratios of 1:1, 2:1, and 3:1 was performed in phosphate buffer saline solution (PBS) (154 mM, pH 7.4) at 37 degrees C. The effect of in vitro degradation time for PDLLA/beta-TCP composites on shape-memory properties was studied by scanning electron microscopy, differential scanning calorimetry, gel permeation chromatography, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The changes of structural morphology, glass transition temperature (T(g)), molecular weight, and weight loss of composites matrix and pH change of degradation medium indicated that shape-memory effects at different degradation time were nonlinearly influenced because of the breaking down of polymer chain and the formation of degradation products. Furthermore, the results from XRD and FTIR implied that the degradation products, for example, hydroxyapatite (HA), calcium hydrogen phosphate (CaHPO(4)), and calcium pyrophosphate (Ca(2)P(2)O(7)) phases also had some effects on shape-memory properties during the degradation. 2007 Wiley Periodicals, Inc.

  13. Effects of plaque, psychological stress and gender on crevicular Il-1beta and Il-1ra secretion.

    Science.gov (United States)

    Waschul, Bernd; Herforth, Armin; Stiller-Winkler, Renate; Idel, Helga; Granrath, Nicole; Deinzer, Renate

    2003-03-01

    The study aimed to analyse (a) whether the effects of psychological stress and of experimental gingivitis on interleukin-1beta (Il-1beta) described before are compensated by concomitant increases in Il-1 receptor antagonist (Il-1ra), and (b) whether there do exist any gender differences in the Il-1 responses to experimental gingivitis and to psychological stress. Thirteen medical students participating in a major academic exam (seven males, six females) and 14 medical students without academic stress (eight males, six females) refrained from oral hygiene in two antagonistic quadrants for 28 days (plaque) while they maintained oral hygiene in the remaining quadrants (hygiene). Weekly crevicular fluid samples of plaque and hygiene sites were assayed for Il-1beta and Il-1ra. Neither stress nor experimental gingivitis exerted significant effects on Il-1ra. In controls, we observed significant gender and gender x time effects on Il-1beta; comparing stress groups, gender x time and stress x gender x time interactions became significant. Women show a reduced Il-1beta response to plaque at rest and an increased response under stress. Similar results were found with respect to bleeding on probing. Gender must be controlled in studies on periodontal responses to pathogens. Stress plays a role in these responses.

  14. Sodium fluorocitrate having protective effect on palmitate-induced beta cell death improves hyperglycemia in diabetic db/db mice.

    Science.gov (United States)

    Jung, Ik-Rak; Choi, Sung-E; Hong, Seung A; Hwang, Yoonjung; Kang, Yup

    2017-10-10

    Beta cell loss and insulin resistance play roles in the pathogenesis of type 2 diabetes. Elevated levels of free fatty acids in plasma might contribute to the loss of beta cells. The objective of this study was to find a chemical that could protect against palmitate-induced beta cell death and investigate whether such chemical could improve hyperglycemia in mouse model of type 2 diabetes. Sodium fluorocitrate (SFC), an aconitase inhibitor, was found to be strongly and specifically protective against palmitate-induced INS-1 beta cell death. However, the protective effect of SFC on palmitate-induced cell death was not likely to be due to its inhibitory activity for aconitase since inhibition or knockdown of aconitase failed to protect against palmitate-induced cell death. Since SFC inhibited the uptake of palmitate into INS-1 cells, reduced metabolism of fatty acids was thought to be involved in SFC's protective effect. Ten weeks of treatment with SFC in db/db diabetic mice reduced glucose level but remarkably increased insulin level in the plasma. SFC improved impairment of glucose-stimulated insulin release and also reduced the loss of beta cells in db/db mice. Conclusively, SFC possessed protective effect against palmitate-induced lipotoxicity and improved hyperglycemia in mouse model of type 2 diabetes.

  15. Effects of pituitary beta-endorphin secretagogues on the concentration of beta-endorphin in rat cerebrospinal fluid : evidence for a role of vasopressin in the regulation of brain beta-endorphin release

    NARCIS (Netherlands)

    Barna, I; Sweep, C G; Veldhuis, H D; Wiegant, V M; De Wied, D

    The concentration of beta-endorphin-immunoreactivity (beta E-IR) in cerebrospinal fluid (CSF) and plasma of rats was determined following intracerebroventricular (ICV) treatment of conscious animals with substances known to stimulate the release of beta E and other pro-opiomelanocortin

  16. Effects of Initial Particle Distribution on an Energetic Dispersal of Particles

    Science.gov (United States)

    Rollin, Bertrand; Ouellet, Frederick; Koneru, Rahul; Garno, Joshua; Durant, Bradford

    2017-11-01

    Accurate predictions of the late time solid particle cloud distribution ensuing an explosive dispersal of particles is an extremely challenging problem for compressible multiphase flow simulations. The source of this difficulty is twofold: (i) The complex sequence of events taking place. Indeed, as the blast wave crosses the surrounding layer of particles, compaction occurs shortly before particles disperse radially at high speed. Then, during the dispersion phase, complex multiphase interactions occurs between particles and detonation products. (ii) Precise characterization of the explosive and particle distribution is virtually impossible. In this numerical experiment, we focus on the sensitivity of late time particle cloud distributions relative to carefully designed initial distributions, assuming the explosive is well described. Using point particle simulations, we study the case of a bed of glass particles surrounding an explosive. Constraining our simulations to relatively low initial volume fractions to prevent reaching of the close packing limit, we seek to describe qualitatively and quantitatively the late time dependency of a solid particle cloud on its distribution before the energy release of an explosive. This work was supported by the U.S. DoE, NNSA, Advanced Simulation and Computing Program, as a Cooperative Agreement under the Predictive Science Academic Alliance Program, under Contract No. DE-NA0002378.

  17. Study on effective particle diameters and coolability of particulate beds packed with irregular multi-size particles

    International Nuclear Information System (INIS)

    Thakre, S.; Ma, W.; Kudinov, P.; Bechta, S.

    2013-08-01

    One of the key questions in severe accident research is the coolability of the debris bed, i.e., whether decay heat can be completely removed by the coolant flow into the debris bed. Extensive experimental and analytical work has been done to substantiate the coolability research. Most of the available experimental data is related to the beds packed with single size (mostly spherical) particles, and less data is available for multi-size/irregular-shape particles. There are several analytical models available, which rely on the mean particle diameter and porosity of the bed in their predictions. Two different types of particles were used to investigate coolability of particulate beds at VTT, Finland. The first type is irregular-shape Aluminum Oxide gravel particles whose sizes vary from 0.25 mm to 10 mm, which were employed in the STYX experiment programme (2001-2008). The second type is spherical beads of Zirconium silicate whose sizes vary between 0.8 mm to 1 mm, which were used in the COOLOCE tests (Takasuo et al., 2012) to study the effect of multi-dimensional flooding on coolability. In the present work, the two types of particles are used in the POMECO-FL and POMECO-HT test facility to obtain their effective particle diameters and dryout heat flux of the beds, respectively. The main idea is to check how the heaters' orientations (vertical in COOLOCE vs. horizontal in POMECO-HT) and diameters (6 mm in COOLOCE vs. 3 mm in POMECO-HT) affect the coolability (dryout heat flux) of the test beds. The tests carried out on the POMECO-FL facility using a bed packed with aluminum oxide gravel particles show the effective particle diameter of the gravel particles is 0.65 mm, by which the frictional pressure gradient can be predicted by the Ergun equation. After the water superficial velocity is higher than 0.0025 m/s, the pressure gradient is underestimated. The effective particle diameter of the zirconium particles is found as 0.8 mm. The dryout heat flux is measured on

  18. Commercial reference shape standards use in the study of particle shape effect on laser diffraction particle size analysis.

    Science.gov (United States)

    Kelly, Richard N; Kazanjian, Jacqueline

    2006-05-26

    The purpose of this paper is to describe the use of LGC Promochem AEA 1001 to AEA 1003 monosized fiber-analog shape standards in the study of the effect of particle shape on laser diffraction (LD) particle size analysis (psa). The psa of the AEA standards was conducted using LD psa systems from Beckman Coulter, Horiba, and Malvern Instruments. Flow speed settings, sample refractive index values, and sample cell types were varied to examine the extent to which the shape effect on LD psa results is modified by these variables. The volume and number probability plots resulting from these measurements were each characterized by a spread in the particle size distribution that roughly extended from the breadth to the longest dimension of the particles. For most of the selected sample refractive index values, the volume probability plots were characterized by apparent bimodal distributions. The results, therefore, provide experimental verification of the conclusions from theoretical studies of LD psa system response to monosized elliptical particles in which this apparent bimodality was the predicted result in the case of flow-oriented particles. The data support the findings from previous studies conducted over the past 10 years that have called into question the verity of the tenets of, and therefore the value of the application of, the equivalent spherical volume diameter theory and the random particle orientation model to the interpretation of LD psa results from measurements made on nonspherical particles.

  19. Mechanical loading prevents the stimulating effect of IL-1{beta} on osteocyte-modulated osteoclastogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, Rishikesh N.; Bakker, Astrid D.; Everts, Vincent [Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Research Institute MOVE, Amsterdam (Netherlands); Klein-Nulend, Jenneke, E-mail: j.kleinnulend@acta.nl [Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Research Institute MOVE, Amsterdam (Netherlands)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer Osteocyte incubation with IL-1{beta} stimulated osteocyte-modulated osteoclastogenesis. Black-Right-Pointing-Pointer Conditioned medium from IL-1{beta}-treated osteocytes increased osteoclastogenesis. Black-Right-Pointing-Pointer IL-1{beta} upregulated RANKL and downregulated OPG gene expression by osteocytes. Black-Right-Pointing-Pointer CYR61 is upregulated in mechanically stimulated osteocytes. Black-Right-Pointing-Pointer Mechanical loading of osteocytes may abolish IL-1{beta}-induced osteoclastogenesis. -- Abstract: Inflammatory diseases such as rheumatoid arthritis are often accompanied by higher plasma and synovial fluid levels of interleukin-1{beta} (IL-1{beta}), and by increased bone resorption. Since osteocytes are known to regulate bone resorption in response to changes in mechanical stimuli, we investigated whether IL-1{beta} affects osteocyte-modulated osteoclastogenesis in the presence or absence of mechanical loading of osteocytes. MLO-Y4 osteocytes were pre-incubated with IL-1{beta} (0.1-1 ng/ml) for 24 h. Cells were either or not subjected to mechanical loading by 1 h pulsating fluid flow (PFF; 0.7 {+-} 0.3 Pa, 5 Hz) in the presence of IL-1{beta} (0.1-1 ng/ml). Conditioned medium was collected after 1 h PFF or static cultures. Subsequently mouse bone marrow cells were seeded on top of the IL-1{beta}-treated osteocytes to determine osteoclastogenesis. Conditioned medium from mechanically loaded or static IL-1{beta}-treated osteocytes was added to co-cultures of untreated osteocytes and mouse bone marrow cells. Gene expression of cysteine-rich protein 61 (CYR61/CCN1), receptor activator of nuclear factor kappa-B ligand (RANKL), and osteoprotegerin (OPG) by osteocytes was determined immediately after PFF. Incubation of osteocytes with IL-1{beta}, as well as conditioned medium from static IL-1{beta}-treated osteocytes increased the formation of osteoclasts. However, conditioned medium from mechanically loaded IL

  20. Effects of beetroot (Beta vulgaris) preparations on the Maillard reaction products in milk and meat-protein model systems

    NARCIS (Netherlands)

    Rackauskienea, I.; Pukalskas, A.; Rimantas Venskutonis, P.; Fiore, A.M.; Troise, A.D.; Fogliano, V.

    2015-01-01

    The effects of beetroots (Beta vulgaris) on the formation of Maillard reaction (MR) products possessing health, nutritional and sensory implications were studied. The effect of dried beetroot juice on the formation of Ne-(carboxymethyl)lysine (CML) and Ne-(2-furoylmethyl)-L-lysine (furosine) was

  1. Medroxyprogesterone acetate attenuates long-term effects of 17 beta-estradiol in coronary arteries from hyperlipidemic rabbits

    DEFF Research Database (Denmark)

    Pedersen, Susan H.; Nielsen, Lars Bo; Mortensen, Alicja

    2006-01-01

    Objective: The progestin component in hormone replacement treatment may oppose the effects of estrogen on vascular function. This study examined the effect of long-term treatment with 17 beta-estradiol (E-2) alone and in combination with two progestins on K+ and Ca2+-mediated mechanisms in coronary...

  2. Use of studies with laboratory animals to assess the potential early health effects of combined internal alpha and beta irradiation

    International Nuclear Information System (INIS)

    Scott, B.R.; Hahn, F.F.; Guilmette, R.A.; Muggenburg, B.A.; Snipes, M.B.; Boecker, B.B.; McClellan, R.O.

    1986-01-01

    The potential health impacts of radionuclides released in nuclear accidents are of major concern to the public and to regulatory and other governmental agencies. One mode of potential exposure is by inhalation of airborne radionuclides, which could lead to combined internal irradiation by high (alpha) and low (beta) linear energy transfer (LET) radiations. Epidemiological data for health effects of human inhalation exposure are too limited to derive reliable estimates of risks of potential health effects. However, results of studies in which beagle dogs were exposed by inhalation to insoluble radioactive aerosols can be used to estimate expected effects in humans. Data for mortality from radiation pneumonitis and pulmonary fibrosis caused by internal irradiation of dog lungs by alpha or beta radiations are used to derive the relative biological effectiveness (RBE) of alpha irradiation compared to beta irradiation; predict the expected combined effects of alpha and beta irradiation of dog lungs; and extrapolate the results to humans. The extrapolation to humans assumed that, for similar ages at exposure, dog and human lungs have similar sensitivities to lung irradiation. Results of theoretical calculations related to mortality from early effects indicated that the synergistic effects of high- and low-LET radiations should depend on the percentages of the total dose contributed by high- and low-LET radiations, and for very low or very high doses, synergistic effects should be negligible. 23 refs., 8 figs

  3. Medroxyprogesterone acetate attenuates long-term effects of 17beta-estradiol in coronary arteries from hyperlipidemic rabbits

    DEFF Research Database (Denmark)

    Pedersen, S. H.; Nielsen, L. B.; Mortensen, A

    2006-01-01

    OBJECTIVE: The progestin component in hormone replacement treatment may oppose the effects of estrogen on vascular function. This study examined the effect of long-term treatment with 17beta-estradiol (E(2)) alone and in combination with two progestins on K(+) and Ca(2+)-mediated mechanisms...

  4. Effect of gamma-irradiation on the whitening activity of {beta}-glucan

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Hun; Sung, Nak Yun; Jung, Pil Moon; Choi, Jong Il; Kim, Jin Kyu; Lee, Ju Woon [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of); Byun, Eui Hong [Chungnam Naitonal University, Daejeon (Korea, Republic of)

    2010-09-15

    This study evaluated the change in whitening activity of {beta}-glucan by gamma-irradiation. Tyrosinase inhibition was significantly increased in the samples with 30, 50, 10 kGy irradiated {beta}-glucan. Melanin synthesis of irradiated {beta}-glucan was measured from B16BL6 melanoma cell line treated with {alpha}-melanin stimulating hormone. Melanin synthesis was increased in the {alpha}-melanin stimulating hormone added group. However, it was decreased in the groups of 30, 50 and 100 kGy gamma-irradiated {beta}-glucan treated with {alpha}-melanin stimulating hormone. These results indicate that gamma irradiated {beta}-glucan may elevate the whitening activity. Therefore, gamma-irradiated {beta}-glucan could be used for nutraceutical foods in cosmetic industry.

  5. Efimov effect, Thomas effect and model dependence of three-particle observables

    International Nuclear Information System (INIS)

    Adhikari, S.K.; Delfino, A.; Frederico, T.; Goldman, I.D.; Tomio, L.

    1987-01-01

    It is demonstrated for the three-dimensional three-particle system that a divergence arising from essentially the same singularity structure of the Kernel of the scattering integral equation is responsible for both the Efimov and Thomas effects. The above divergence implies that the results of three-particle dynamical calculation be sensitive to the details of the two-particle interaction. In two-dimensional systems the above divergence is absent and consequently the three-particle observables become essentially model independent. (M.W.O.) [pt

  6. Effects of cholinergic and beta-adrenergic blockade on orthostatic tolerance in healthy subjects

    Science.gov (United States)

    Convertino, V. A.; Sather, T. M.

    2000-01-01

    Cardiovascular responses during a graded lower body negative pressure (LBNP) protocol were compared before and after atropine and propranolol administration to test the hypothesis that both sympathetic and parasympathetic control of cardio-acceleration are associated with syncopal predisposition to orthostatic stress in healthy subjects. Eleven men were categorized into two groups having high (HT, N = 6) or low (LT, N = 5) tolerance based on their total time before the onset of presyncopal symptoms. HT and LT groups were similar in physical characteristics, fitness, and baseline cardiovascular measurements. Atropine treatment had no effect on LBNP tolerance or mean arterial pressure at presyncope, despite an atropine-induced increase in heart rate. Propranolol treatment reduced (p<0.05) LBNP tolerance in both groups. Diminished LBNP tolerance after propranolol administration was associated with reductions in cardiac output, whereas increase in systemic peripheral resistance from baseline to presyncope was unaffected by propranolol. Reduction in cardiac output and LBNP tolerance after beta blockade reflected a chronotropic effect because lower LBNP tolerance for the HT (-50%) and LT (-39%) groups was associated with dramatic reductions (p <0.05) in the magnitude of LBNP-induced tachycardia without significant effects on stroke volume at presyncope. Absence of an atropine-induced difference in cardiac output and systemic peripheral resistance between HT and LT groups failed to support the notion that cardiac vagal withdrawal represents a predominant mechanism that could account for differences in orthostatic tolerance. Because a reduction in LBNP tolerance in both HT and LT groups after propranolol treatment was most closely associated with reduced tachycardia, the data suggest that a primary autonomically mediated mechanism for maintenance of mean arterial pressure and orthostatic tolerance in healthy subjects is beta adrenergic-induced tachycardia.

  7. Long-term effects of beta-blocker use on lung function in Japanese patients with chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Oda N

    2017-04-01

    Full Text Available Naohiro Oda,1 Nobuaki Miyahara,1,2 Hirohisa Ichikawa,3 Yasushi Tanimoto,4 Kazuhiro Kajimoto,5 Makoto Sakugawa,6 Haruyuki Kawai,7 Akihiko Taniguchi,1 Daisuke Morichika,1 Mitsune Tanimoto,1 Arihiko Kanehiro,1 Katsuyuki Kiura1 1Department of Allergy and Respiratory Medicine, Okayama University Hospital, 2Department of Medical Technology, Okayama University Graduate School of Health Sciences, Okayama, 3Department of Respiratory Medicine, KKR Takamatsu Hospital, Takamatsu, 4Department of Respiratory Medicine, National Hospital Organization Minami-Okayama Medical Center, Okayama, 5Department of Respiratory Medicine, Kobe Red Cross Hospital, Kobe, 6Department of Respiratory Medicine, Okayama Red Cross Hospital, 7Department of Respiratory Medicine, Okayama Saiseikai Hospital, Okayama, Japan Background: Some recent studies have suggested that beta-blocker use in patients with chronic obstructive pulmonary disease (COPD is associated with a reduction in the frequency of acute exacerbations. However, the long-term effects of beta-blocker use on lung function of COPD patients have hardly been evaluated. Patients and methods: We retrospectively reviewed 31 Japanese COPD patients taking beta-blockers for >1 year and 72 patients not taking them. The association between beta-blocker use and the annual change in forced expiratory volume in 1 second (FEV1 was assessed. Results: At baseline, patient demographic characteristics were as follows: 97 males (mean age 67.0±8.2 years; 32 current smokers; and Global Initiative for Chronic Obstructive Lung disease (GOLD stages I: n=26, II: n=52, III: n=19, and IV: n=6. Patients taking beta-blockers exhibited a significantly lower forced vital capacity (FVC, FEV1, and %FVC, and a more advanced GOLD stage. The mean duration of beta-blocker administration was 2.8±1.7 years. There were no differences in the annual change in FEV1 between patients who did and did not use beta-blockers (-7.6±93.5 mL/year vs -4.7±118.9 m

  8. [Effects of ionizing radiation on scintillators and other particle detectors

    International Nuclear Information System (INIS)

    Proudfoot, J.

    1992-01-01

    It is my task to summarise the great variety of topics (covering a refreshing mix of physics, chemistry and technology) presented at this conference, which has focused on the effects of ionising radiation on scintillators and other particle detectors. One of the reasons and the central interest of many of the participants was the use of such detectors in experiments at two future large hadron colliders: the Superconducting Super Collider to be operating outside of Dallas in the United States by the turn of the decade and its European counterpart the Large Hadron Collider to be operating outside of Geneva in Switzerland on a similar time scale. These accelerators are the ''apple of the high energy physicist's eye.'' Their goal is to uncover the elusive Higgs particle and thereby set the cornerstone in our current knowledge of elementary particle interactions. This is the Quest, and from this lofty height the presentations rapidly moved on to the specific questions of experimental science: how such an experiment is carried out; why radiation damage is an issue; how radiation damage affects detectors; which factors affect radiation damage characteristics; which factors are not affected by radiation damage; and how better detectors may be constructed. These were the substance of this conference

  9. Comparison of the molecular effects of the mycotoxins beta-zearalenol and deoxynivalenol in porcine endometrial cells--a review.

    Science.gov (United States)

    Wollenhaupt, Karin; Tomek, W; Tiemann, Ute

    2007-03-01

    The mycotoxins beta-zearalenol (beta-ZOL) and deoxynivalenol (DON) produce toxic effects that result in diseases in humans and animals. The molecular mechanisms that control the mycotoxin-mediated effects are far from being completely understood. Various results show that these mycotoxins could inhibit cell proliferation. In the present short communication, the influence of beta-ZOL and DON on the abundance and phosphorylation state of kinases that are included in regulation of the initiation of mRNA translation (which is correlated with cell proliferation) was compared in porcine endometrial cells (PEC). Our results indicate that these mycotoxins modulate the expression and phosphorylation of these factors in a different manner. Whereas beta-ZOL mainly had an impact on the biological activity of the extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), protein kinase B (Akt), eukaryotic initiation factor 4E (eIF4E) and its repressor 4E binding protein 1 (4E-BP1), DON reduced the abundance of p38 MAPk, Akt and specific 4E-BP1 bands. In summary, these results indicate that beta-ZOL influences molecular events that are included in the initiation of mRNA translation in the porcine endometrium but DON does not alter such processes clearly.

  10. Effects of energetic particle precipitation on the atmospheric electric circuit

    International Nuclear Information System (INIS)

    Reagan, J.B.; Meyerott, R.E.; Evans, J.E.; Imhof, W.L.; Joiner, R.G.

    1983-01-01

    The solar particle event (SPE) of August 1972 is one of the largest that has occurred in the last 20 years. Since it is so well documented, it can serve as a good example of a major perturbation to the atmospheric electric system. In this paper, ion production rates and conductivities from the ground to 80 km at the peak intensity of the event on August 4 and for 30, 35, and 40 km for the 6-day duration of the event are presented. At the peak of the event, the proton and electron precipitation currents, the ohmic current, and the vertical electric field are calculated inside the polar cap. The particle precipitation currents at this time greatly exceed the normal air earth current at altitudes above 30 km and produce reversals in the vertical electric field at 28 km and above. Calculations are presented of the vertical electric field at altitudes near 30 km where balloon measurements were made. Good agreement between the calculated and the measured vertical electric field verifies our ability to calculate disturbed conductivities at these altitudes from satellite measurements of proton spectra incident on the atmosphere. Despite the fact that at the peak of the event the vertical electric field near 30 km was shorted out by the solar particles and that the current carried by the solar particles exceeded the fair weather air-earth current density in the stratosphere by large factors, it is concluded that the largest effect of an SPE of this magnitude on the atmospheric electric circuit is due to the Forbush decrease in the galactic cosmic ray flux rather than to the large increase in solar proton flux

  11. Effect of beta-blocker therapy on functional status in patients with heart failure--a meta-analysis

    DEFF Research Database (Denmark)

    Abdulla, Jawdat; Køber, Lars; Christensen, Erik

    2005-01-01

    Association (NYHA) classification and exercise tolerance in chronic heart failure. METHODS AND RESULTS: We selected 28 RCTs evaluating beta-blocker versus placebo in addition to ACE inhibitor therapy. Combined results of 23 RCTs showed that beta-blockers improved NYHA class by at least one class with odds...... ratio (OR) 1.80 (1.33-2.43) poxygen uptake and 9 RCTs evaluating 6-min walk distance showed that beta-blockers had no significant effect...... compared with placebo, p=0.484, and p=0.730, respectively. Combined results of the 23 RCTs showed significant reducing effect on all cause mortality with OR=0.69 (0.59-0.82) ptherapy improves dyspnoea and prolongs exercise...

  12. Effect of indirect non-thermal plasma on particle size distribution and composition of diesel engine particles

    Science.gov (United States)

    Linbo, GU; Yixi, CAI; Yunxi, SHI; Jing, WANG; Xiaoyu, PU; Jing, TIAN; Runlin, FAN

    2017-11-01

    To explore the effect of the gas source flow rate on the actual diesel exhaust particulate matter (PM), a test bench for diesel engine exhaust purification was constructed, using indirect non-thermal plasma technology. The effects of different gas source flow rates on the quantity concentration, composition, and apparent activation energy of PM were investigated, using an engine exhaust particle sizer and a thermo-gravimetric analyzer. The results show that when the gas source flow rate was large, not only the maximum peak quantity concentrations of particles had a large drop, but also the peak quantity concentrations shifted to smaller particle sizes from 100 nm to 80 nm. When the gas source flow rate was 10 L min-1, the total quantity concentration greatly decreased where the removal rate of particles was 79.2%, and the variation of the different mode particle proportion was obvious. Non-thermal plasma (NTP) improved the oxidation ability of volatile matter as well as that of solid carbon. However, the NTP gas source rate had little effects on oxidation activity of volatile matter, while it strongly influenced the oxidation activity of solid carbon. Considering the quantity concentration and oxidation activity of particles, a gas source flow rate of 10 L min-1 was more appropriate for the purification of particles.

  13. The stimulatory effect of growth hormone, prolactin, and placental lactogen on beta-cell proliferation is not mediated by insulin-like growth factor-I

    DEFF Research Database (Denmark)

    Billestrup, N; Nielsen, Jens Høiriis

    1991-01-01

    The effects of GH, PRL, and placental lactogen (PL) on the proliferation of pancreatic beta-cells in vitro were studied as well as the possible effect of insulin-like growth factor-I (IGF-I) in mediating this effect. Proliferating beta-cells were identified by staining with a monoclonal antibody ...

  14. Effect of long-acting beta2 agonists on exacerbation rates of asthma in children

    DEFF Research Database (Denmark)

    Bisgaard, Hans

    2003-01-01

    The purpose of this analysis was to examine the effect of long-acting beta(2)-adrenoceptor agonists (LABAs) on the asthma exacerbation rate in pediatric patients. Randomized controlled trials (RCT) that included the use of LABAs to treat symptoms of pediatric asthma in children on inhaled...... corticosteroids, that reported asthma exacerbation rates, and that were published as full papers in peer-reviewed journals were retrieved from a search of the medical literature. Eight studies were identified that fulfilled these criteria. An exacerbation was defined as deterioration in a patient's asthma...... requiring a change in prescribed medication or not defined but reported as an asthma exacerbation or an asthma-related hospitalization. Analysis of data from the eight studies revealed no apparent protection from an asthma exacerbation among children on a LABA compared to patients on comparator treatment...

  15. Annealing Effect on Corrosion Behavior of the Beta-Quenched HANA Alloy

    International Nuclear Information System (INIS)

    Kim, Hyun Gil; Kim, Il Hyun; Choi, Byung Kwan; Park, Sang Yoon; Park, Jeong Yong; Jeong, Yong Hwan

    2009-01-01

    The advanced fuel cladding materials named as HANA cladding have been developed at KAERI for application of high burn-up and that cladding showed an improved performance in both in-pile and out-of-pile conditions. However, the cladding performance could be changed by the annealing conditions during the tube manufacturing process. Especially, the corrosion resistance is considerably sensitive to their microstructure which is determined by a manufacturing process in the high Nb-containing zirconium alloys. They reported that the corrosion properties of the Nb-containing Zr alloys were considerably affected by the microstructure conditions such as the Nb concentration in the matrix and the second phase types. Therefore, the corrosion behavior of HANA cladding having the high Nb could be considerably affected by the annealing time and temperatures. The purpose of this study is focused on the annealing effect of the beta quenched HANA alloy to obtain the optimum annealing conditions

  16. Effects of feeding Beta vulgaris saccharifera bulb for fattening desert lambs under tropical conditions of Sudan

    Directory of Open Access Journals (Sweden)

    M D Mohammed

    2012-12-01

    Full Text Available Aim: The objective of this study was to evaluate the effects of introducing Sugar Beet bulb as a cheap substitute for grains in rations formulated for sheep fattening. Materials and Methods: This trial was conducted at the Experimental unit of Rural Development and extension center, Faculty of animal production, University of Gezira. Twenty four Sudanese desert lambs (Ashgur ecotype were purchased from local markets to assess the effects of replacing grain with Sugar Beet (Beta vulgaris saccharifera Bulb on feed lot performance, carcass traits under tropical conditions of Sudan. Sugar Beet bulb was incorporated in three rations with a control ration (A: control, B, C, D at percentages of 0, 11, 22, and 33. Results: The results showed that total weight gain and daily feed intake in group D were significantly different at (P<0.05 where values of 5.59±1.73 and 0.94± 0.13 kg were recorded. Total weight gain, daily dry matter intake, daily energy intake and feed conversion ratio were in the range of 10.67- 5.59, 1.03-0.83, 0.33-0.27and 11.77- 7.70 kg respectively. Treatments showed no significant differences at (P<0.05 for slaughter weight, empty body weight, dressing % on slaughter weight basis and dressing % on empty weight basis, the obtained results for these traits were 27.78-25.37, 24.76- 22.22, 45.80- 43.45% and 51.41- 49.65%. Carcass cuts (Leg, Loin, Rack, Plate and Neck & shoulder weight and percentages showed no significant differences among treatments. Conclusion: It is concluded that replacing expensive grains with Beta vulgaris bulb can be practiced in sheep fattening project up to 22% with excellent results. [Vet. World 2012; 5(6.000: 330-334

  17. Can Beta Blockers Cause Weight Gain?

    Science.gov (United States)

    Beta blockers: Do they cause weight gain? Can beta blockers cause weight gain? Answers from Sheldon G. ... can occur as a side effect of some beta blockers, especially the older ones, such as atenolol ( ...

  18. Adrenergic receptor effects and antihypertensive actions of beta-adrenoceptor-blocking agents with ancillary properties.

    Science.gov (United States)

    Imai, S; Nakahara, H; Nakazawa, M; Takeda, K

    1988-01-01

    The acute antihypertensive effects and possible underlying mechanisms of 3 beta-adrenergic-blocking drugs with alpha-blocking activity, i.e. labetalol, drugs with alpha-blocking activity, i.e. labetalol, nipradilol and arotinolol, were studied in conscious spontaneously hypertensive rats (SHR) and compared with the effects of prazosin, propranolol and hydralazine. Prazosin produced a dose-dependent antihypertensive effect which paralleled inhibition of the pressor response to phenylephrine. Labetalol (30 mg/kg), nipradilol (30 and 100 mg/kg) and arotinolol (30 and 100 mg/kg) also produced a fall in blood pressure. However, inhibition of the pressor response to phenylephrine was not seen in association with the antihypertensive effect after the lower dose of nipradilol and arotinolol. Propranolol (100 mg/kg) did not lower blood pressure. These results suggest that a mechanism(s) other than an alpha-adrenergic-blocking effect plays a role in the acute antihypertensive effects produced by the lower dose of nipradilol and arotinolol.

  19. Effects of Alkali-Metal Ions and Counter Ions in Sn-Beta-Catalyzed Carbohydrate Conversion.

    Science.gov (United States)

    Elliot, Samuel G; Tolborg, Søren; Madsen, Robert; Taarning, Esben; Meier, Sebastian

    2018-02-26

    Alkali-metal ions have recently been shown to strongly influence the catalytic behavior of stannosilicates in the conversion of carbohydrates. An effect of having alkali-metal ions present is a pronounced increase in selectivity towards methyl lactate. Mechanistic details of this effect have remained obscure and are herein addressed experimentally through kinetic experiments and isotope tracking. The presence of alkali-metal ions has a differential effect in competing reaction pathways and promotes the rate of carbon-carbon bond breakage of carbohydrate substrates, but decreases the rates of competing dehydration pathways. Further addition of alkali-metal ions inhibits the activity of Sn-Beta in all major reaction pathways. The alkali-metal effects on product distribution and on the rate of product formation are similar, thus pointing to a kinetic reaction control and to irreversible reaction steps in the main pathways. Additionally, an effect of the accompanying basic anions is shown, supposedly facilitating the cation exchange and eliciting a different concentration-dependent effect to that of neutral alkali-metal salts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. The effects of beta alanine plus creatine administration on performance during repeated bouts of supramaximal exercise in sedentary men.

    Science.gov (United States)

    Okudan, N; Belviranli, M; Pepe, H; Gökbel, H

    2015-11-01

    The aim of this study was to investigate the effects of beta alanine and/or creatine supplementation on performance during repeated bouts of supramaximal exercise in sedentary men. Forty-four untrained healthy men (aged 20-22 years, weight: 68-72 kg, height: 174-178 cm) participated in the present study. After performing the Wingate Test (WAnT) for three times in the baseline exercise session, the subjects were assigned to one of four treatment groups randomly: 1) placebo (P; 10 g maltodextrose); 2) creatine (Cr; 5 g creatine plus 5 g maltodextrose); 3) beta-alanine (β-ALA; 1,6 g beta alanine plus 8,4 g maltodextrose); and 4) beta-alanine plus creatine (β-ALA+Cr; 1,6 g beta alanine plus 5 g creatine plus 3,4 g maltodextrose). Participants were given the supplements orally twice a day for 22 consecutive days, then four times a day for the following 6 days. After 28 days, the second exercise session was applied during which peak power (PP) and mean power (MP) were measured and fatigue index (FI) was calculated. PP and MP decreased and FI increased in all groups during exercise before and after the treatment. During the postsupplementation session PP2 and PP3 increased in creatine supplemented group (from 642.7±148.6 to 825.1±205.2 in PP2 and from 522.9±117.5 to 683.0±148.0 in PP3, respectively). However, MP increased in β-ALA+Cr during the postsupplementation compared to presupplementation in all exercise sessions (from 586.2±55.4 to 620.6±49.6 in MP1, from 418.1±37.2 to 478.3±30.3 in MP2 and from 362.0±41.3 to 399.1±3 in MP3, respectively). FI did not change with beta alanine and beta alanine plus creatine supplementation during the postsupplementation exercise session. Beta-alanine and beta alanine plus creatine supplementations have strong performance enhancing effect by increasing mean power and delaying fatigue Index during the repeated WAnT.

  1. Experimental and Simulation Analysis of Radiation of the Beta Emitting Sources in a Magnetic Field

    Directory of Open Access Journals (Sweden)

    Berrin Çavuşoğlu

    2017-06-01

    Full Text Available Objective: The behavior of beta particles under the magnetic field was investigated both theoretically and experimentally based on the assumption of reducing the damage to the normal tissues created by using magnetic field in radionuclide therapy. Methods: A water-filled spherical medium and a beta particle source was formed by using Geant4 simulation software for the theoretical study. After applying a homogenous magnetic field, the volume of points at which the particles interact with the medium was calculated by determining particle range. The range of beta particles was examined using yttrium-90 source and Gafchromic films for the experimental study. The setup was kept in normal room conditions and in the magnetic resonance imaging device. Then the irradiated films were analyzed by creating isodose curves. Results: With the increase of the magnetic field, the number of hits at the center was increased, but the number of hits at the outer boundaries decreased inversely proportional to the strength of the magnetic field. The change perpendicular to the magnetic field was greater as compared to the change parallel to the magnetic field. The volume of hits of beta particles got smaller with the increase of the magnetic field. Conclusion: When magnetic field is increased, the decrease in the number of interactions at the outer boundaries became more pronounced in the perpendicular direction to the magnetic field. The effect of magnetic field was more apparent for higher energy beta particles than lower energy particles.

  2. Effects of beta-adrenergic blockers with different ancillary properties on lipid peroxidation in hyperthyroid rat cardiac muscle.

    Science.gov (United States)

    Asayama, K; Dobashi, K; Hayashibe, H; Kato, K

    1989-10-01

    To determine whether beta-blockade protects rat heart against thyroxine (T4)-induced accelelation of lipid peroxidation, in vivo effects of 3 beta-blockers with different ancillary properties on the mitochondrial oxidative enzyme, antioxidant enzymes and lipid peroxide were investigated. The rats were rendered hyperthyroid by adding T4 to their drinking water for 3 weeks and were treated simultaneously with either carteolol (a blocker with partial agonist activity; 30 mg/kg/day), atenolol (50 mg/kg/day) or arotinolol (a blocker with weak alpha-blocking action; 50 mg/kg/day). The T4-induced tachycardia was alleviated completely by either atenolol or arotinolol, but only partially by carteolol. Cytochrome c oxidase activity in the heart muscle was increased by T4 with a parallel increase in manganese (mitochondrial) superoxide dismutase. Atenolol, but neither carteolol nor arotinolol, suppressed this increase. Similarly, the T4-induced acceleration of lipid peroxidation was suppressed by atenolol alone. Glutathione peroxidase was markedly decreased, and both copper zinc (cytosolic) superoxide dismutase and catalase were also decreased or tended to be decreased by T4. The levels of these 3 enzymes were only minimally affected by the beta-blocker treatments. These results suggest that beta-blockade suppresses mitochondrial hypermetabolism and protects heart muscle against oxidative stress in hyperthyroidism, and that the ancillary properties of beta-blockers such as partial agonist activity and alpha-blocking action negate the protection.

  3. Thermal stability and aggregation of creatine kinase from rabbit skeletal muscle. Effect of 2-hydroxypropyl-beta-cyclodextrin.

    Science.gov (United States)

    Maloletkina, Olga I; Markossian, Kira A; Belousova, Lyubov V; Kleimenov, Sergey Yu; Orlov, Victor N; Makeeva, Valentina F; Kurganov, Boris I

    2010-05-01

    Effect of 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on thermal aggregation of creatine kinase from rabbit skeletal muscle (RMCK) at 48 degrees C has been studied using dynamic light scattering. An increase in the duration of the lag period on the kinetic curves of aggregation, registered as an increment of the light scattering intensity in time, has been observed in the presence of HP-beta-CD. It has been shown that the initial parts of the dependences of the hydrodynamic radius (R(h)) of the protein aggregates on time follow the exponential law. The reciprocal value of parameter t(2R) (t(2R) is the time interval over which the R(h) value is doubled) was used to characterize the rate of aggregation. A 10-fold decrease in the 1/t(2R) value was observed in the presence of 76mM HP-beta-CD. Judging from the data on the kinetics of RMCK inactivation and the data on differential scanning calorimetry of RMCK, HP-beta-CD does not affect the rate of RMCK unfolding.

  4. Acute and timing effects of beta-hydroxy-beta-methylbutyrate (HMB on indirect markers of skeletal muscle damage

    Directory of Open Access Journals (Sweden)

    Manninen Anssi H

    2009-02-01

    Full Text Available Abstract Background While chronic β-Hydroxy β-Methylbutyrate (HMB supplementation (≥ 2 wk lowers exercise induced muscle damage, its acute or timing effects have not been examined. The purpose of this study was to investigate the acute and timing effects of oral HMB supplementation on serum creatine kinase (CK, lactate dehydrogenase (LDH, muscle soreness, and maximal voluntary contraction (MVC. Methods Sixteen non-resistance trained men (22 ± 2 yrs were assigned to HMB-Pre or HMB-Post groups. In a crossover design, all subjects performed 55 maximal eccentric knee extension/flexion contractions on 2 occasions on either the right or left leg. HMB-Pre (N = 8 randomly received 3 grams of either a placebo or HMB before and a placebo after exercise. HMB-Post (N = 8 received a placebo before and either 3 grams of HMB or a placebo after exercise. Muscle damage tests were recorded before, at 8, 24, 48, and 72 hrs post exercise. Results There was a reduction in MVC and an increase in soreness in the quadriceps and hamstrings following exercise (p p = 0.07, there was no time × group effect. Serum indices of damage increased, peaking at 48 hrs for CK (773% (p p Conclusion Our findings suggest no clear acute or timing effects of HMB supplementation. However, consuming HMB before exercise appeared to prevent increases in LDH.

  5. Effect of particle size on degree of inversion in ferrites

    International Nuclear Information System (INIS)

    Siddique, M.; Butt, N.M.

    2012-01-01

    Ferrites with the spinel structure are important materials because of their structural, magnetic and electrical properties. The suitability of these materials depends on both the intrinsic behavior of the material and the effects of the grain size. Moessbauer spectroscopy was employed to investigate the cation distribution and degree of inversion in bulk and nano sized particles of CuFe/sub 2/O/sub 4/, MnFe/sub 2/O/sub 4/ and NiFe/sub 2/O/sub 4/ ferrites. The Moessbauer spectra of all bulk ferrites showed complete magnetic behavior, whereas nanoparticle ferrites showed combination of ferromagnetic and superparamagnetic components. Moreover, the cation distribution in nanoparticle materials was also found to be different to that of their bulk counterparts indicating the particle size dependency. The inversion of Cu and Ni ions in bulk sample was greater than that of nanoparticles; whereas the inversion of Mn ions was less in bulk material as compared to the nanoparticles. Hence the degree of inversion decreased in CuFe/sub 2/O/sub 4/ and NiFe/sub 2/O/sub 4/ samples whereas, it increased in MnFe/sub 2/O/sub 4/ as the particle size decreased and thus showed the anomalous behavior in this case. The nanoparticle samples also showed paramagnetic behaviour due to superparamagnetism and this effect is more prominent in MnFe/sub 2/O/sub 4/. Moessbauer spectra of bulk and nanoparticles CuFe/sub 2/O/sub 4/ is shown. (Orig./A.B.)

  6. Speculative Betas

    OpenAIRE

    Harrison Hong; David Sraer

    2012-01-01

    We provide a model for why high beta assets are more prone to speculative overpricing than low beta ones. When investors disagree about the common factor of cash-flows, high beta assets are more sensitive to this macro-disagreement and experience a greater divergence-of-opinion about their payoffs. Short-sales constraints for some investors such as retail mutual funds result in high beta assets being over-priced. When aggregate disagreement is low, expected return increases with beta due to r...

  7. Effect of iron on pancreatic beta cell function and insulin resistance

    African Journals Online (AJOL)

    Dr Olaleye

    the incidence of diabetes mellitus was investigated on the pancreatic beta cell function and insulin resistance in normal ... hyperglycaemia, insulin resistance, hyperinsulinaemia, inflammation and pancreatic beta cell dysfunction thus predisposing the ..... and antioxidant status in alpha-thalassemia major: iron overload and ...

  8. Chemokine receptor expression on B cells and effect of interferon-beta in multiple sclerosis

    DEFF Research Database (Denmark)

    Sørensen, Torben Lykke; Roed, Hanne; Sellebjerg, Finn

    2002-01-01

    We investigated the B-cell expression of chemokine receptors CXCR3, CXCR5 and CCR5 in the blood and cerebrospinal fluid (CSF) from patients in relapse of multiple sclerosis (MS) and in neurological controls. Chemokine receptor expression was also studied in interferon-beta-treated patients with r......, and chemokine receptor expression was not affected by interferon-beta treatment....

  9. Effect of preoperative beta-blockade on perioperative mortality in coronary surgery

    NARCIS (Netherlands)

    ten Broecke, P. W. C.; de Hert, S. G.; Mertens, E.; Adriaensen, H. F.

    2003-01-01

    BACKGROUND: Many preoperative factors can influence perioperative mortality in cardiac surgery. Because the perioperative use of beta-blocking agents may reduce perioperative cardiac complications in non-cardiac surgery, we considered the possibility that beta-blocking agents could improve survival

  10. Effect van beta-HCH op humana mamma tumorcellen (MCF-7)

    NARCIS (Netherlands)

    Coosen R; Thijssen JHH; van Velsen FL; Loeber JG

    1985-01-01

    Beta-HCH induceert in analogie met oestrogenen de synthese van de progesteron receptor op een dosis-gerelateerde wijze vanaf 10-7 M tot ongeveer 2,5x10-5 M (verzadigde oplossing). Een beta-HCH-metaboliet, 2,4,6-trichloorfenol (TCF), veroorzaakt in veel mindere mate inductie bij veel hogere

  11. The effect of bed non-uniformities and porosity of particles on dryout in boiling particle beds

    International Nuclear Information System (INIS)

    Macbeth, R.V.; Mogford, D.J.; Willshire, S.J.

    1988-03-01

    This report relates to an on-going experimental programme concerned with the coolability of beds of reactor core debris or rubble immersed in a liquid coolant, as might occur in an accident situation. The objectives are to develop experimental techniques, improve the understanding of bed cooling mechanisms, determine dry-out limitations of various bed configurations and particle shapes and sizes and devise ways of improving bed coolability. The report concentrates on a recently discovered effect on bed coolability of particle porosity, such as exists in fragmented UO 2 fuel pellets. It is shown that porosity can lower bed dry-out powers by a factor of 4 or 5. A mechanism which explains the effect is presented. The report also gives results of bed non-uniformities obtained by mixing glass particles with the dielectrically heated 'ferrite' particles used in the experiments. (author)

  12. The Effect of Tacrolimus on Reactive Oxygen Species and Total Antioxidant Status in Pancreatic Beta Cell Line.

    Science.gov (United States)

    Namvaran, Fatemeh; Sharifi, Ali; Namvaran, Mohamad Mehdi; Maruf, Neda; Azarpira, Negar

    2015-12-01

    The mechanism responsible for the development of posttransplant diabetes mellitus associated with tacrolimus treatment remains unclear. To investigate the possible effect of tacrolimus on the development of impaired glucose tolerance in transplant recipients, this study focused on early and second phase insulin secretion, which may be affected by reactive oxygen species under tacrolimus therapy. We measured the anti-oxidant status and reactive oxygen species levels before and after tacrolimus treatment. The pro-duction of reactive oxygen species was determined by flow cytometry. Total antioxidant status was measured using total antioxidant status kits. The antioxidant status decreased while reactive oxygen species level increased significantly (P = .032) CONCLUSIONS: Tacrolimus treatment resulted in dose- and time-dependent increases in the production of reactive oxygen species by beta cells. The antioxidant status decreased in beta cells after tacrolimus treatment. Increased production of reactive oxygen species and decreased antioxidant status by tacrolimus in beta cells may lead to some adverse events.

  13. Effects of beta-adrenergic blockade on endurance and short-time performance in respect to individual muscle fiber composition.

    Science.gov (United States)

    Kaiser, P; Rössner, S; Karlsson, J

    1981-02-01

    Nine physically active males were studied three times with four different exercise tests after administration of placebo, 0.1 g atenolol, or 0.08 g propranolol in random order. The test modals were: bicycle ergometer exercise at 50% of VO2max, peak torque during knee extension, the Wingate muscle power test, and 2000 m track running. Muscle fiber composition had previously been determined. In subjects with a high percentage of slow-twitch fibers the beta-blockers caused a more marked impairment in the exercising muscles. This effect was more pronounced with the unselective beta-blocker propranolol than with atenolol. One interpretation of our findings is that peripheral sympathetic beta 2-receptors in skeletal muscles may contribute to regulating muscle metabolism.

  14. Magnitude of intrinsic isotope effects in the dopamine beta-monooxygenase reaction.

    Science.gov (United States)

    Miller, S M; Klinman, J P

    1983-06-21

    Intrinsic primary hydrogen isotope effects (kH/kD) have been obtained for the carbon-hydrogen bond cleavage step catalyzed by dopamine beta-monooxygenase. Irreversibility of this step is inferred from the failure to observe back-exchange of tritium from TOH into substrate under conditions of dopamine turnover; this result cannot be due to solvent inaccessibility at the enzyme active site, since we will demonstrate [Ahn, N., & Klinman, J. P. (1983) Biochemistry (following paper in this issue)] that a solvent-derived proton or triton must be at the enzyme active site prior to substrate activation. As shown by Northrop [Northrop, D. B. (1975) Biochemistry 14, 2644], for enzymatic reactions in which the carbon-hydrogen bond cleavage step is irreversible, comparison of D(V/K) to T(V/K) allows an explicit solution for kH/kD. Employing a double-label tracer method, we have been able to measure deuterium isotope effects on Vmax/Km with high precision, D(V/K) = 2.756 +/- 0.054 at pH 6.0. The magnitude of the tritium isotope effect under comparable experimental conditions is T(V/K) = 6.079 +/- 0.220, yielding kH/kD = 9.4 +/- 1.3. This result was obtained in the presence of saturating concentrations of the anion activator fumarate. Elimination of fumarate from the reaction mixture leads to high observed values for isotope effects on Vmax/Km, together with an essentially invariant value for kH/kD = 10.9 +/- 1.9. Thus, the large disparity between isotope effects, plus or minus fumarate, cannot be accounted for by a change in kH/kD, and we conclude a role for fumarate in the modulation of the partitioning of enzyme-substrate complex between catalysis and substrate dissociation. On the basis of literature correlations of primary hydrogen isotope effects and the thermodynamic properties of hydrogen transfer reactions, the very large magnitude of kH/kD = 9.4-10.9 for dopamine beta-monooxygenase suggests an equilibrium constant not very far from unity for the carbon-hydrogen bond

  15. Effect of transforming growth factor-beta1 on decorin expression and muscle morphology during chicken embryonic and posthatch growth and development.

    Science.gov (United States)

    Li, X; Velleman, S G

    2009-02-01

    During skeletal muscle development, transforming growth factor-beta1 (TGF-beta1) is a potent inhibitor of muscle cell proliferation and differentiation, as well as a regulator of extracellular matrix (ECM) production. Decorin, a member of the small leucine-rich ECM proteoglycans, binds to TGF-beta1 and modulates TGF-beta1-dependent cell growth stimulation or inhibition. The expression of decorin can be regulated by TGF-beta1 during muscle proliferation and differentiation. How TGF-beta1 affects decorin and muscle growth, however, has not been well documented in vivo. The present study investigated the effect of TGF-beta1 on decorin expression and intracellular connective tissue development during skeletal muscle growth. Exogenous TGF-beta1 significantly decreased the number of myofibers in a given area at both 1 d and 6 wk posthatch. The TGF-beta1-treated muscle had a significant decrease in decorin mRNA expression at embryonic day (ED) 10, whereas protein amounts decreased at 17 ED and 1 d posthatch compared to the control muscle. Decorin was localized in both the endomysium and perimysium in the control pectoralis major muscle. Transforming growth factor-beta1 reduced decorin in both the endomysium and perimysium from 17 ED to 6 wk posthatch. Compared to the control muscle, the perimysium space in the pectoralis major muscle was dramatically decreased by TGF-beta1 during embryonic development through posthatch growth. Because decorin regulates collagen fibrillogenesis, a major component of the ECM, the reduction of decorin by TGF-beta1 treatment may cause the irregular formation of collagen fibrils, leading to the decrease in endomysium and perimysium space. The results from the current study suggest that the effect of TGF-beta1 on decorin expression and localization was likely associated with altered development of the perimysium and the regulation of muscle fiber development.

  16. Effect of age on upregulation of the cardiac adrenergic beta receptors

    International Nuclear Information System (INIS)

    Tumer, N.; Houck, W.T.; Roberts, J.

    1990-01-01

    Radioligand binding studies were performed to determine whether upregulation of postjunctional beta receptors occurs in sympathectomized hearts of aged animals. Fischer 344 rats 6, 12, and 24 months of age (n = 10) were used in these experiments. To produce sympathectomy, rats were injected with 6-hydroxydopamine hydrobromide (6-OHDA; 2 x 50 mg/kg iv) on days 1 and 8; the animals were decapitated on day 15. The depletion of norepinephrine in the heart was about 86% in each age group. 125I-Iodopindolol (IPIN), a beta adrenergic receptor antagonist, was employed to determine the affinity and total number of beta adrenergic receptors in the ventricles of the rat heart. The maximal number of binding sites (Bmax) was significantly elevated by 37%, 48%, and 50% in hearts from sympathectomized 6-, 12-, and 24-month-old rats, respectively. These results indicate that beta receptor mechanisms in older hearts can respond to procedures that cause upregulation of the beta adrenergic receptors

  17. Morphological Evolution of Block Copolymer Particles: Effect of Solvent Evaporation Rate on Particle Shape and Morphology.

    Science.gov (United States)

    Shin, Jae Man; Kim, YongJoo; Yun, Hongseok; Yi, Gi-Ra; Kim, Bumjoon J

    2017-02-28

    Shape and morphology of polymeric particles are of great importance in controlling their optical properties or self-assembly into unusual superstructures. Confinement of block copolymers (BCPs) in evaporative emulsions affords particles with diverse structures, including prolate ellipsoids, onion-like spheres, oblate ellipsoids, and others. Herein, we report that the evaporation rate of solvent from emulsions encapsulating symmetric polystyrene-b-polybutadiene (PS-b-PB) determines the shape and internal nanostructure of micron-sized BCP particles. A distinct morphological transition from the ellipsoids with striped lamellae to the onion-like spheres was observed with decreasing evaporation rate. Experiments and dissipative particle dynamics (DPD) simulations showed that the evaporation rate affected the organization of BCPs at the particle surface, which determined the final shape and internal nanostructure of the particles. Differences in the solvent diffusion rates in PS and PB at rapid evaporation rates induced alignment of both domains perpendicular to the particle surface, resulting in ellipsoids with axial lamellar stripes. Slower evaporation rates provided sufficient time for BCP organization into onion-like structures with PB as the outermost layer, owing to the preferential interaction of PB with the surroundings. BCP molecular weight was found to influence the critical evaporation rate corresponding to the morphological transition from ellipsoid to onion-like particles, as well as the ellipsoid aspect ratio. DPD simulations produced morphologies similar to those obtained from experiments and thus elucidated the mechanism and driving forces responsible for the evaporation-induced assembly of BCPs into particles with well-defined shapes and morphologies.

  18. Effect of low mass dark matter particles on the Sun

    CERN Document Server

    Taoso, Marco; Meynet, Georges; Bertone, Gianfranco; Eggenberger, Patrick

    2010-01-01

    We study the effect of dark matter (DM) particles in the Sun, focusing in particular on the possible reduction of the solar neutrinos flux due to the energy carried away by DM particles from the innermost regions of the Sun, and to the consequent reduction of the temperature of the solar core. We find that in the very low-mass range between 4 and 10 GeV, recently advocated to explain the findings of the DAMA and CoGent experiments, the effects on neutrino fluxes are detectable only for DM models with very small, or vanishing, self-annihilation cross section, such as the so-called asymmetric DM models, and we study the combination of DM masses and Spin Dependent cross sections which can be excluded with current solar neutrino data. Finally, we revisit the recent claim that DM models with large self-interacting cross sections can lead to a modification of the position of the convective zone, alleviating or solving the solar composition problem. We show that when the `geometric' upper limit on the capture rate i...

  19. Solar particle effects on minor components of the Polar atmosphere

    Directory of Open Access Journals (Sweden)

    A. Damiani

    2008-02-01

    Full Text Available Solar activity can influence the Earth's environment, and in particular the ozone layer, by direct modulation of the e.m. radiation or through variability of the incoming cosmic ray flux (solar and galactic particles. In particular, solar energetic particles (SEPs provide additional external energy to the terrestrial environment; they are able to interact with the minor constituents of the atmospheric layer and produce ionizations, dissociations, dissociative ionizations and excitations. This paper highlights the SEP effects on the chemistry of the upper atmosphere by analysing some SEP events recorded during 2005 in the descending phase of the current solar cycle. It is shown that these events can lead to short- (hours and medium- (days term ozone variations through catalytic cycles (e.g. HOx and NOx increases. We focus attention on the relationship between ozone and OH data (retrieved from MLS EOS AURA for four SEP events: 17 and 20 January, 15 May and 8 September. We confirm that SEP effects are different on the night and day hemispheres at high latitudes.

  20. Health effects assessment of exposure to particles from wood smoke

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Elsa; Dybdahl, M. (Technical Univ. of Denmark, National Food Institute, Dept. of Toxicology and Risk Assessment, Soeborg (Denmark)); Larsen, Poul Bo (Danish Environmental Protection Agency, Copenhagen (Denmark))

    2008-07-01

    The number of residential wood burning devices has increased in Denmark during the latest years and it has been estimated that there in 2005 were about 551,000 wood stoves and about 48,000 wood boilers in Denmark. This has resulted in an increased exposure of the general Danish population to pollutants associated with residential wood smoke. New Danish monitoring results on particulate matter (PM) in ambient air have shown elevated PM levels in areas with many wood stoves, particularly during wintertime when wood burning is common. Due to the size distribution of wood smoke particles essentially all will be contained in the PM{sub 2.5} fraction. It has been estimated that about 17,665 tonnes PM{sub 2.5} per year (2005) in Denmark come from residential wood combustion. Therefore, there is an increasing concern that adverse human health effects might be associated with the increased exposure to residential wood smoke. This project has been set up in order to review the scientific literature concerning adverse health effects of pollutants associated with residential wood smoke with the main focus on particulate matter and to quantify and evaluate, if possible, the impact on human health of the increased exposure to particles in residential wood smoke. (au)

  1. Effects of amino acid substitutions at beta 131 on the structure and properties of hemoglobin: evidence for communication between alpha 1 beta 1- and alpha 1 beta 2-subunit interfaces.

    Science.gov (United States)

    Chang, Chung-ke; Simplaceanu, Virgil; Ho, Chien

    2002-04-30

    Substitutions of Asn, Glu, and Leu for Gln at the beta131 position of the hemoglobin molecule result in recombinant hemoglobins (rHbs) with moderately lowered oxygen affinity and high cooperativity compared to human normal adult hemoglobin (Hb A). The mutation site affects the hydrogen bonds present at the alpha(1)beta(1)-subunit interface between alpha103His and beta131Gln as well as that between alpha122His and beta35Tyr. NMR spectroscopy shows that the hydrogen bonds are indeed perturbed; in the case of rHb (beta131Gln --> Asn) and rHb (beta131Gln --> Leu), the perturbations are propagated to the other alpha(1)beta(1)-interface H-bond involving alpha122His and beta35Tyr. Proton exchange measurements also detect faster exchange rates for both alpha(1)beta(1)-interface histidine side chains of the mutant rHbs in 0.1 M sodium phosphate buffer at pH 7.0 than for those of Hb A under the same conditions. In addition, the same measurements in 0.1 M Tris buffer at pH 7.0 show a much slower exchange rate for mutant rHbs and Hb A. One of the mutants, rHb (beta131Gln --> Asn), shows the conformational exchange of its interface histidines, and exchange rate measurements have been attempted. We have also conducted studies on the reactivity of the SH group of beta93Cys (a residue located in the region of the alpha(1)beta(2)-subunit interface) toward p-mercuribenzoate, and our results show that low-oxygen-affinity rHbs have a more reactive beta93Cys than Hb A in the CO form. Our results indicate that there is communication between the alpha(1)beta(1)- and alpha(1)beta(2)-subunit interfaces, and a possible communication pathway for the cooperative oxygenation of Hb A that allows the alpha(1)beta(1)-subunit interface to modulate the functional properties in conjunction with the alpha(1)beta(2) interface is proposed.

  2. Effect of beta-adrenoceptor blockers on human ether-a-go-go-related gene (HERG) potassium channels

    DEFF Research Database (Denmark)

    Dupuis, Delphine S; Klaerke, Dan A; Olesen, Søren-Peter

    2005-01-01

    -1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol hydrochloride) blocked the HERG channel with similar affinity, whereas the beta1-receptor antagonists metoprolol and atenolol showed weak effects. Further, the four compounds blocked HERG channels expressed in a mammalian HEK293 cell line...

  3. Effect of aspirin on the Wnt/beta-catenin pathway is mediated via protein phosphatase 2A

    NARCIS (Netherlands)

    Bos, C. L.; Kodach, L. L.; van den Brink, G. R.; Diks, S. H.; van Santen, M. M.; Richel, D. J.; Peppelenbosch, M. P.; Hardwick, J. C. H.

    2006-01-01

    Nonsteroidal anti-inflammatory drugs show chemopreventive efficacy in colon cancer, but the mechanism behind this remains unclear. Elucidating this mechanism is seen as vital to the development of new chemopreventive agents. We studied the effects of aspirin on the oncogenic Wnt/beta-catenin pathway

  4. Effects of acute beta-adrenoceptor blockade with metoprolol on the renal response to dopamine in normal humans

    DEFF Research Database (Denmark)

    Olsen, Niels Vidiendal; Lang-Jensen, T; Hansen, J M

    1994-01-01

    The present study investigated the contribution of adrenergic beta 1-receptor stimulation to the cardiovascular and renal effects of low-dose dopamine in eight normal, water-loaded humans. Metoprolol (100 mg) or placebo was administered orally at 08.00 h in a randomized, double-blind fashion on two...

  5. Effect of four medicinal plants on amyloid-beta induced neurotoxicity in SH-SY5Y Cells

    CSIR Research Space (South Africa)

    Adewusi, EA

    2013-01-01

    Full Text Available Amyloid-beta peptide (Aß) is implicated in the pathogenesis of Alzheimer’s disease (AD), a neurodegenerative disorder. This study was designed to determine the effect of four medicinal plants used to treat neurodegenerative diseases on Aß...

  6. The effect of particle size on the morphology and thermodynamics of diblock copolymer/tethered-particle membranes

    International Nuclear Information System (INIS)

    Zhang, Bo; Edwards, Brian J.

    2015-01-01

    A combination of self-consistent field theory and density functional theory was used to examine the effect of particle size on the stable, 3-dimensional equilibrium morphologies formed by diblock copolymers with a tethered nanoparticle attached either between the two blocks or at the end of one of the blocks. Particle size was varied between one and four tenths of the radius of gyration of the diblock polymer chain for neutral particles as well as those either favoring or disfavoring segments of the copolymer blocks. Phase diagrams were constructed and analyzed in terms of thermodynamic diagrams to understand the physics associated with the molecular-level self-assembly processes. Typical morphologies were observed, such as lamellar, spheroidal, cylindrical, gyroidal, and perforated lamellar, with the primary concentration region of the tethered particles being influenced heavily by particle size and tethering location, strength of the particle-segment energetic interactions, chain length, and copolymer radius of gyration. The effect of the simulation box size on the observed morphology and system thermodynamics was also investigated, indicating possible effects of confinement upon the system self-assembly processes

  7. Marked over expression of uncoupling protein-2 in beta cells exerts minor effects on mitochondrial metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Hals, Ingrid K., E-mail: ingrid.hals@ntnu.no [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Ogata, Hirotaka; Pettersen, Elin [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Ma, Zuheng; Bjoerklund, Anneli [Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm (Sweden); Skorpen, Frank [Department of Laboratory Medicine, NTNU, Trondheim (Norway); Egeberg, Kjartan Wollo [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Grill, Valdemar [Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm (Sweden)

    2012-06-29

    Highlights: Black-Right-Pointing-Pointer The impact of UCP-2 over expression on mitochondrial function is controversial. Black-Right-Pointing-Pointer We tested mitochondrial functions at defined levels of overexpression. Black-Right-Pointing-Pointer We find minor increases of fatty acid oxidation and uncoupling. Black-Right-Pointing-Pointer Effects were seen only at high level (fourfold) of over expression. Black-Right-Pointing-Pointer Hence it is doubtful whether these effects are of importance in diabetes. -- Abstract: Evidence is conflicting as to the impact of elevated levels of uncoupling protein-2 (UCP-2) on insulin-producing beta cells. Here we investigated effects of a fourfold induction of UCP-2 protein primarily on mitochondrial parameters and tested for replication of positive findings at a lower level of induction. We transfected INS-1 cells to obtain a tet-on inducible cell line. A 48 h exposure to 1 {mu}g/ml of doxycycline (dox) induced UCP-2 fourfold (424 {+-} 113%, mean {+-} SEM) and 0.1 {mu}g/ml twofold (178 {+-} 29%, n = 3). Fourfold induced cells displayed normal viability (MTT, apoptosis), normal cellular insulin contents and, glucose-induced insulin secretion (+27 {+-} 11%) as well as D-[U-{sup 14}C]-glucose oxidation (+5 {+-} 9% at 11 mM glucose). Oxidation of [1-{sup 14}C]-oleate was increased from 4088 to 5797 fmol/{mu}g prot/2 h at 3.3 mM glucose, p < 0.03. Oxidation of L-[{sup 14}C(U)]-glutamine was unaffected. Induction of UCP-2 did not significantly affect measures of mitochondrial membrane potential (Rhodamine 123) or mitochondrial mass (Mitotracker Green) and did not affect ATP levels. Oligomycin-inhibited oxygen consumption (a measure of mitochondrial uncoupling) was marginally increased, the effect being significant in comparison with dox-only treated cells, p < 0.05. Oxygen radicals, assessed by dichlorofluorescin diacetate, were decreased by 30%, p < 0.025. Testing for the lower level of UCP-2 induction did not reproduce any of the

  8. Effect of silica particle size on macrophage inflammatory responses.

    Directory of Open Access Journals (Sweden)

    Toshimasa Kusaka

    Full Text Available Amorphous silica particles, such as nanoparticles (<100 nm diameter particles, are used in a wide variety of products, including pharmaceuticals, paints, cosmetics, and food. Nevertheless, the immunotoxicity of these particles and the relationship between silica particle size and pro-inflammatory activity are not fully understood. In this study, we addressed the relationship between the size of amorphous silica (particle dose, diameter, number, and surface area and the inflammatory activity (macrophage phagocytosis, inflammasome activation, IL-1β secretion, cell death and lung inflammation. Irrespective of diameter size, silica particles were efficiently internalized by mouse bone marrow-derived macrophages via an actin cytoskeleton-dependent pathway, and induced caspase-1, but not caspase-11, activation. Of note, 30 nm-1000 nm diameter silica particles induced lysosomal destabilization, cell death, and IL-1β secretion at markedly higher levels than did 3000 nm-10000 nm silica particles. Consistent with in vitro results, intra-tracheal administration of 30 nm silica particles into mice caused more severe lung inflammation than that of 3000 nm silica particles, as assessed by measurement of pro-inflammatory cytokines and neutrophil infiltration in bronchoalveolar lavage fluid of mice, and by the micro-computed tomography analysis. Taken together, these results suggest that silica particle size impacts immune responses, with submicron amorphous silica particles inducing higher inflammatory responses than silica particles over 1000 nm in size, which is ascribed not only to their ability to induce caspase-1 activation but also to their cytotoxicity.

  9. Effect of sodium bicarbonate and Beta-alanine on repeated sprints during intermittent exercise performed in hypoxia.

    Science.gov (United States)

    Saunders, Bryan; Sale, Craig; Harris, Roger C; Sunderland, Caroline

    2014-04-01

    To investigate the separate and combined effects of sodium bicarbonate and beta-alanine supplementation on repeated sprints during simulated match play performed in hypoxia. Study A: 20 recreationally active participants performed two trials following acute supplementation with either sodium bicarbonate (0.3 g·kg-1BM) or placebo (maltodextrin). Study B: 16 recreationally active participants were supplemented with either a placebo or beta-alanine for 5 weeks (6.4 g·day-1 for 4 weeks, 3.2 g·day-1 for 1 week), and performed one trial before supplementation (with maltodextrin) and two following supplementation (with sodium bicarbonate and maltodextrin). Trials consisted of 3 sets of 5 × 6 s repeated sprints performed during a football specific intermittent treadmill protocol performed in hypoxia (15.5% O2). Mean (MPO) and peak (PPO) power output were recorded as the performance measures. Study A: Overall MPO was lower with sodium bicarbonate than placebo (p = .02, 539.4 ± 84.5 vs. 554.0 ± 84.6 W), although there was no effect across sets (all p > .05). Study B: There was no effect of beta-alanine, or cosupplementation with sodium bicarbonate, on either parameter, although there was a trend toward higher MPO with sodium bicarbonate (p = .07). The effect of sodium bicarbonate on repeated sprints was equivocal, although there was no effect of beta-alanine or cosupplementation with sodium bicarbonate. Individual variation may have contributed to differences in results with sodium bicarbonate, although the lack of an effect with beta-alanine suggests this type of exercise may not be influenced by increased buffering capacity.

  10. Resummation and renormalization in effective theories of particle physics

    CERN Document Server

    Jakovac, Antal

    2015-01-01

    Effective models of strong and electroweak interactions are extensively applied in particle physics phenomenology, and in many instances can compete with large-scale numerical simulations of Standard Model physics. These contexts include but are not limited to providing indications for phase transitions and the nature of elementary excitations of strong and electroweak matter. A precondition for obtaining high-precision predictions is the application of some advanced functional techniques to the effective models, where the sensitivity of the results to the accurate choice of the input parameters is under control and the insensitivity to the actual choice of ultraviolet regulators is ensured. The credibility of such attempts ultimately requires a clean renormalization procedure and an error estimation due to a necessary truncation in the resummation procedure. In this concise primer we discuss systematically and in sufficient technical depth the features of a number of approximate methods, as applied to vario...

  11. Particle shape effects in vitro and in vivo.

    Science.gov (United States)

    Harris, Bradley J; Dalhaimer, Paul

    2012-06-01

    Particles that have the potential to deliver imaging agents and drugs to cells and tissue now have many different shapes and sizes. This diversity in particle shape could provide new options for potential treatments of diseases because geometry affects biodistribution. However, the myriad of particle shapes now available increases the number of variables or parameters that must be taken into consideration for the drug delivery field to understand particle-cell interactions. This is especially true when the shape of a particle is a tunable parameter along with particle chemistry, charge, and hydrophobicity. Here we review the impact of shape on particle-cell interactions in vitro and the ramifications of different particle geometries on circulation, biodistribution, localization to tumors, and toxicology in rodents.

  12. Particle size effect on velocity of gold particle embedded laser driven plastic targets

    Directory of Open Access Journals (Sweden)

    Dhareshwar L.J.

    2013-11-01

    Full Text Available A scheme to enhance the target foil velocity has been investigated for a direct drive inertial fusion target. Polymer PVA (polyvinyl alcohol or (C2H4On target foils of thickness 15–20 μm were used in plain form and also embedded with gold in the nano-particle (Au-np or micro-particle (Au-mp form. Nano-particles were of 20–50 nm and micro-particles of 2–3 μm in size. 17% higher target velocity was measured for foils embedded with nano-particle gold (Au-np as compared to targets embedded with micro-particles gold (Au-mp. The weight of gold in both cases was in the range 40–55% of the full target weight (atomic percentage of about 22%. Experiments were performed with the single beam of the Prague Asterix Laser System (PALS at 0.43 μm wavelength (3ω of the fundamental wavelength, 120 Joule energy and 300 psec pulse duration. Laser intensity on the target was about 1015 W/cm2. A simple model has been proposed to explain the experimental results.

  13. THYMUS PEPTIDES (THYMULIN, THYMOSIN ALPHA 1 AND THYMOSIN BETA 4 INHIBITING EFFECTS ON THE INTRINSIC BLOOD COAGULATION PATHWAY IN RATS

    Directory of Open Access Journals (Sweden)

    Negrin Negrev

    2017-08-01

    Full Text Available Thymus peptides (thymulin, thymosin alpha 1 and thymosin beta 4 inhibiting effects on the intrinsic blood coagulation pathway in rats Background and purpose: Hemostasis is a basic homeostatic mechanism protecting the body from thrombosis or haemorrhage. A number of pathological conditions, including multiple endocrine disorders modulate the balance between pro- and anticoagulation factors and establish conditions of hyper- or hypocoagulability. Endocrine effects of thymus gland on blood coagulation are not completely elucidated, and data existing on the theme are relatively scarce and partially controversial. The present study was designed to investigate thymus peptides (thymulin, thymosin alpha 1 and thymosin beta 4 effects on key intrinsic pathway plasma clotting factors XII, XI, IX, X and activated partial thromboplastin time (aPTT – a principal marker of blood coagulation via intrinsic pathway of hemocoagulation, in rats. Materials and methods: Plasma clotting factor activities and aPTT were studied on 52 male Wistar intact rats after 3 day s.c. application of the thymic peptides envisaged using routine kinetic coagulometry. Results of the study indicate a significant reduction of FXII activity by thymulin and thymosin alpha 1, and FXI and FIX activity by thymulin and thymosin beta 4. Conclusion: Upper results support the conclusion that thymus peptides thymulin, thymosin alpha 1 and thymosin beta 4 application in rats imposes a distinct tendency of hypocoagulability.

  14. Beta2-microglobulin.

    Science.gov (United States)

    Drüeke, Tilman B; Massy, Ziad A

    2009-01-01

    Among the uremic toxins in the "middle molecule" range, beta2-microglobulin (beta2-M) is certainly one of the most frequently studied compounds. Its serum level increases with the progression of chronic kidney disease, to reach very high concentrations in patients with end-stage kidney disease. It is the major protein component of dialysis-related amyloidosis, a dramatic complication which results from high extracellular concentration and posttranslational modification of beta2-M and a number of other promoters of amyloid fibril formation and deposition in osteo-articular tissues. Effective removal of beta2-M can be achieved with highly effective hemodialysis and hemodiafiltration techniques but predialysis session serum levels cannot be normalized. The prevalence and severity of beta2-M amyloidosis appear to have decreased in the last 20 years, although its occurrence may simply be delayed.

  15. Effects of beta-hydroxy-beta-methylbutyrate (HMB on exercise performance and body composition across varying levels of age, sex, and training experience: A review

    Directory of Open Access Journals (Sweden)

    Wilson Jacob M

    2008-01-01

    Full Text Available Abstract The leucine metabolite beta-hydroxy-beta-methylbutyrate (HMB has been extensively used as an ergogenic aid; particularly among bodybuilders and strength/power athletes, who use it to promote exercise performance and skeletal muscle hypertrophy. While numerous studies have supported the efficacy of HMB in exercise and clinical conditions, there have been a number of conflicting results. Therefore, the first purpose of this paper will be to provide an in depth and objective analysis of HMB research. Special care is taken to present critical details of each study in an attempt to both examine the effectiveness of HMB as well as explain possible reasons for conflicting results seen in the literature. Within this analysis, moderator variables such as age, training experience, various states of muscle catabolism, and optimal dosages of HMB are discussed. The validity of dependent measurements, clustering of data, and a conflict of interest bias will also be analyzed. A second purpose of this paper is to provide a comprehensive discussion on possible mechanisms, which HMB may operate through. Currently, the most readily discussed mechanism has been attributed to HMB as a precursor to the rate limiting enzyme to cholesterol synthesis HMG-coenzyme A reductase. However, an increase in research has been directed towards possible proteolytic pathways HMB may operate through. Evidence from cachectic cancer studies suggests that HMB may inhibit the ubiquitin-proteasome proteolytic pathway responsible for the specific degradation of intracellular proteins. HMB may also directly stimulate protein synthesis, through an mTOR dependent mechanism. Finally, special care has been taken to provide future research implications.

  16. Effects of Genetically Modified Milk Containing Human Beta-Defensin-3 on Gastrointestinal Health of Mice.

    Directory of Open Access Journals (Sweden)

    Xin Chen

    Full Text Available This study was performed to investigate the effects of genetically modified (GM milk containing human beta-defensin-3 (HBD3 on mice by a 90-day feeding study. The examined parameters included the digestibility of GM milk, general physical examination, gastric emptying function, intestinal permeability, intestinal microflora composition of mice, and the possibility of horizontal gene transfer (HGT. The emphasis was placed on the effects on gastrointestinal (GI tract due to the fact that GI tract was the first site contacting with food and played crucial roles in metabolic reactions, nutrition absorption and immunity regulation in the host. However, the traditional methods for analyzing the potential toxicological risk of GM product pay little attention on GI health. In this study, the results showed GM milk was easy to be digested in simulated gastric fluid, and it did not have adverse effects on general and GI health compared to conventional milk. And there is little possibility of HGT. This study may enrich the safety assessment of GM product on GI health.

  17. The effect of Leiber Beta-S (1,3-1,6-β-D-glucan on the phagocytic activity and oxidative metabolism of peripheral blood granulocytes and monocytes in calves

    Directory of Open Access Journals (Sweden)

    Roman Wójcik

    2014-01-01

    Full Text Available The effect of the Leiber Beta-S (1,3-1,6-β-D-glucan dietary supplement on the phagocytic activity (Phagotest and oxidative metabolism (Phagoburst of peripheral blood granulocytes and monocytes in calves was determined by flow cytometry. Fourteen animals were divided into two groups: a control group without dietary supplementation and an experimental group administered 50 mg/kg body weight/day of 1,3-1,6-β-D-glucan for 60 days. At the beginning of the experiment (day 0 and on days 15, 30 and 60, blood was sampled from the jugular vein to determine and compare immunological indicators. Leiber Beta-S significantly influenced (P ≤ 0.05, P ≤ 0.01, P ≤ 0.001 the percentages of phagocytic granulocytes (days 15 and 30 and monocytes (days 15, 30 and 60, and the percentage of bacteria engulfed by granulocytes (days 15 and 30 and monocytes (day 30. Leiber Beta-S increased the percentage of cells generating a respiratory burst in the population of granulocytes stimulated with fMLP (N-formyl-met-leu-phe (day 15, PMA (4-phorbol-12-β-myristate-13-acetate and Escherichia coli bacteria (days 15 and 30, and in the population of monocytes stimulated with fMLP (day 30, PMA (days 30 and 60 and E. coli (days 15, 30 and 60. The analyzed supplement increased mean fluorescence intensity in granulocytes stimulated with E. coli and fMLP (days 15 and 30 and PMA (days 30 and 60 as well as in monocytes stimulated with PMA, E. coli and fMLP (day 60. The findings of this study contribute to a better understanding of the effects of Leiber Beta-S on phagocytosis in calves, which have not been investigated to date.

  18. Re-entering fast ion effects on NBI heating power in high-beta plasmas of the Large Helical Device

    International Nuclear Information System (INIS)

    Seki, Ryosuke; Watanabe, Kiyomasa; Funaba, Hisamichi; Suzuki, Yasuhiro; Sakakibara, Satoru; Ohdachi, Satoshi; Matsumoto, Yutaka; Hamamatsu, Kiyotaka

    2011-10-01

    We calculate the heating power of the neutral beam injection (NBI) in the = 4.8% high-beta discharge achieved in the Large Helical Device (LHD). We investigate the difference of the heating efficiency and the heating power profile between with and without the re-entering fast ion effects. When the re-entering fast ion effects are taken into account, the heating efficiency in the co injection of the NBI (co-NBI case) is improved and it is about 1.8 times larger than that without the re-entering effects. In contrast, the heating efficiency with the re-entering effects in the counter injection of the NBI (ctr-NBI case) rarely differs from that without the re-entering ones. We also study the re-entering fast ion effects on the transport properties in the LHD high beta discharges. It is found that the tendency of the thermal conductivities on the beta value is not so much sensitive with and without the re-entering effects. In addition, we investigate the difference in the re-entering fast ion effects caused by the field strength and the magnetic configuration. In the co-NBI case, the re-entering fast ion effects on the heating efficiency increases with the decrease of the field strength. In the contrast, the re-entering fast ion effects in the ctr-NBI case rarely differs by changing the field strength. (author)

  19. Biosorbents prepared from wood particles treated with anionic polymer and iron salt: Effect of particle size on phosphate adsorption

    Science.gov (United States)

    Thomas L. Eberhardt; Soo-Hong Min

    2008-01-01

    Biomass-based adsorbents have been widely studied as a cost-effective and environmentally-benign means to remove pollutants and nutrients from water. A two-stage treatment of aspen wood particles with solutions of carboxymethyl cellulose (CMC) and ferrous chloride afforded a biosorbent that was effective in removing phosphate from test solutions. FTIR spectroscopy of...

  20. Reinforced polypropylene composites: effects of chemical compositions and particle size.

    Science.gov (United States)

    Ashori, Alireza; Nourbakhsh, Amir

    2010-04-01

    In this work, the effects of wood species, particle sizes and hot-water treatment on some physical and mechanical properties of wood-plastic composites were studied. Composites of thermoplastic reinforced with oak (Quercus castaneifolia) and pine (Pinus eldarica) wood were prepared. Polypropylene (PP) and maleic anhydride grafted polypropylene (MAPP) were used as the polymer matrix and coupling agent, respectively. The results showed that pine fiber had significant effect on the mechanical properties considered in this study. This effect is explained by the higher fiber length and aspect ratio of pine compared to the oak fiber. The hot-water treated (extractive-free) samples, in both wood species, improved the tensile, flexural and impact properties, but increased the water absorption for 24h. This work clearly showed that lignocellulosic materials in both forms of fiber and flour could be effectively used as reinforcing elements in PP matrix. Furthermore, extractives have marked effects on the mechanical and physical properties. Copyright 2009 Elsevier Ltd. All rights reserved.

  1. Effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation depend on treatment dose, treatment duration and meal contents

    Energy Technology Data Exchange (ETDEWEB)

    Arakawa, Masayuki; Ebato, Chie; Mita, Tomoya [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Hirose, Takahisa [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Kawamori, Ryuzo [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Center for Beta Cell Biology and Regeneration, Juntendo University School of Medicine, Tokyo (Japan); Sportology Center, Juntendo University School of Medicine, Tokyo (Japan); Fujitani, Yoshio, E-mail: fujitani@juntendo.ac.jp [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Center for Therapeutic Innovations in Diabetes, Juntendo University School of Medicine, Tokyo (Japan); Watada, Hirotaka, E-mail: hwatada@juntendo.ac.jp [Department of Medicine, Metabolism and Endocrinology, Juntendo University School of Medicine, Tokyo (Japan); Sportology Center, Juntendo University School of Medicine, Tokyo (Japan)

    2009-12-18

    Beta-cell proliferation is regulated by various metabolic demands including peripheral insulin resistance, obesity, and hyperglycemia. In addition to enhancement of glucose-induced insulin secretion, agonists for glucagon-like peptide-1 receptor (GLP-1R) stimulate proliferation and inhibit apoptosis of beta-cells, thereby probably preserve beta-cell mass. To evaluate the beta-cell preserving actions of GLP-1R agonists, we assessed the acute and chronic effects of exendin-4 on beta-cell proliferation, mass and glucose tolerance in C57BL/6J mice under various conditions. Short-term administration of high-dose exendin-4 transiently stimulated beta-cell proliferation. Comparative transcriptomic analysis showed upregulation of IGF-1 receptor and its downstream effectors in islets. Treatment of mice with exendin-4 daily for 4 weeks (long-term administration) and feeding high-fat diet resulted in significant inhibition of weight gain and improvement of glucose tolerance with reduced insulin secretion and beta-cell mass. These findings suggest that long-term GLP-1 treatment results in insulin sensitization of peripheral organs, rather than enhancement of beta-cell proliferation and function, particularly when animals are fed high-fat diet. Thus, the effects of exendin-4 on glucose tolerance, insulin secretion, and beta-cell proliferation largely depend on treatment dose, duration of treatment and meal contents. While GLP-1 enhances proliferation of beta-cells in some diabetic mice models, our results suggest that GLP-1 stimulates beta-cell growth only when expansion of beta-cell mass is required to meet metabolic demands.

  2. Effects of interferon beta-1b on black holes in multiple sclerosis over a 6-year period with monthly evaluations.

    Science.gov (United States)

    Bagnato, Francesca; Gupta, Shiva; Richert, Nancy D; Stone, Roger D; Ohayon, Joan M; Frank, Joseph A; McFarland, Henry F

    2005-11-01

    Chronic, hypointense black holes (BHs) are recognized as a sign of permanent damage in patients with multiple sclerosis. Although the effects of interferon beta-1b in reducing the formation of new BHs are established, it is not clear whether the drug may reduce BH duration after these lesions are formed. To analyze the effects of interferon beta-1b in reducing the duration of T1 BHs in patients with multiple sclerosis. Patients were clinically assessed and imaged monthly over a 36-month natural history phase and 36-month therapy phase. Numbers of contrast-enhanced lesions and newly formed BHs were counted on each scan. Each BH was counted until it was no longer seen. Outpatient service of the Neuroimmunology Branch at the National Institutes of Health, Bethesda, Md. Six patients with relapsing-remitting multiple sclerosis were included. One patient did not form any BHs during the therapy phase. Analyses were performed on the remaining 5 individuals. Interferon beta-1b at the dosage of 8 million international units every other day. Number and duration (in months) of newly formed BHs. Rate of BH accumulation decreased with treatment (P = .01), but Kaplan-Meier models revealed that the duration of BHs did not shorten (chi2(1) = 2.47, P = .12). Interferon beta-1b reduces the frequency of new BH formation but does not appear to decrease their duration in time. Analyses with larger patient cohorts are needed to confirm these preliminary findings.

  3. Effects of 17beta-estradiol and xenoestrogens on mouse embryonic stem cells.

    Science.gov (United States)

    Jung, Eui-Man; Choi, Kyung-Chul; Yu, Frank H; Jeung, Eui-Bae

    2010-09-01

    Xenoestrogens such as 4-tert-octylphenol (OP) and 4-nonylphenol (NP) can adversely affect the reproductive and immune systems from their estrogenic effects in target cells. In this study, we investigated the effects of xenoestrogens on the expression of undifferentiation markers in mouse embryonic stem (ES) cells and of cardiomyocyte differentiation markers in mouse embryoid body (EB) cells induced to differentiate into cardiomyocytes from ES cells. The expressions of undifferentiation markers (Oct4, Sox2, Zfp206, and Rex-1) and cardiomyocyte differentiation markers (alpha-MHC, beta-MHC, ANF, and MLC-2V) were determined by semi- and quantitative real-time PCR. Treatment with E(2) or OP and NP induced an increase in Oct4 expression at the transcriptional level in a dose- and time-dependent manner. However, no difference was observed in the expression of Sox2, Zfp206 or Rex-1 genes in ES cells, suggesting that E(2) may be an Oct4 enhancer in ES cells. Induction of Oct4 expression by E(2) and xenoestrogens (OP and NP) did not change the methylation pattern of the Oct4-promoter and was not affected by treatment with a demethylating agent, 5-azacytidine. Taken together, these results suggest that E(2) and xenoestrogens may impact on the undifferentiation process of ES and EB cells, and retain ES cells in an undifferentiated state. Copyright 2010 Elsevier Ltd. All rights reserved.

  4. Traffic effects on soil compaction and sugar beet (Beta vulgaris L.) taproot quality parameters

    International Nuclear Information System (INIS)

    Marinello, F.; Pezzuolo, A.; Cillis, D.; Chiumenti, A.; Sartori, L.

    2017-01-01

    Soil compaction is a critical issue in agriculture having a significant influence on crop growth. Sugar beet (Beta vulgaris L.) is accounted as a crop susceptible to compaction. Reduction of leaf area, final yield, and root quality parameters are reported in compacted soils. The most obvious visual indicator of topsoil compaction is root depth affected by agricultural tractor and machinery traffic up on the soil. Such indicators are mainly correlated to initial soil condition, tyre features, and number of passages. Monitoring and controlling frequency and position of machine traffic across the field, in such a way that passages are completed on specific, well-defined tracks, can assist with minimization of compaction effects on soil. The objective of the present work was to analyze the subsoil compaction during the growing period of sugar beet with different farming approaches including controlled traffic passages and random traffic. To this end, tests were carried out following each agro technical operation using penetrometer readings in order to monitor the state of cone-index after each step. In addition, at the harvesting time, root quality parameters were analyzed with particular attention to length and regularity of the taproot, total length, circumference, mass, and above-ground biomass. Such parameters were usefully implemented in order to evaluate the effects of controlled traffic passages compared to the random traffic in a cultivation of sugar beet. Results highlight how an increase in crop yield, derived from samples monitored, higher than 10% can be expected with implementation of a careful traffic management.

  5. Traffic effects on soil compaction and sugar beet (Beta vulgaris L.) taproot quality parameters

    Energy Technology Data Exchange (ETDEWEB)

    Marinello, F.; Pezzuolo, A.; Cillis, D.; Chiumenti, A.; Sartori, L.

    2017-09-01

    Soil compaction is a critical issue in agriculture having a significant influence on crop growth. Sugar beet (Beta vulgaris L.) is accounted as a crop susceptible to compaction. Reduction of leaf area, final yield, and root quality parameters are reported in compacted soils. The most obvious visual indicator of topsoil compaction is root depth affected by agricultural tractor and machinery traffic up on the soil. Such indicators are mainly correlated to initial soil condition, tyre features, and number of passages. Monitoring and controlling frequency and position of machine traffic across the field, in such a way that passages are completed on specific, well-defined tracks, can assist with minimization of compaction effects on soil. The objective of the present work was to analyze the subsoil compaction during the growing period of sugar beet with different farming approaches including controlled traffic passages and random traffic. To this end, tests were carried out following each agro technical operation using penetrometer readings in order to monitor the state of cone-index after each step. In addition, at the harvesting time, root quality parameters were analyzed with particular attention to length and regularity of the taproot, total length, circumference, mass, and above-ground biomass. Such parameters were usefully implemented in order to evaluate the effects of controlled traffic passages compared to the random traffic in a cultivation of sugar beet. Results highlight how an increase in crop yield, derived from samples monitored, higher than 10% can be expected with implementation of a careful traffic management.

  6. Micro-seeding and soft template effects on the control of polymorph and morphology of HMX micro particles in solvent-antisolvent process

    Directory of Open Access Journals (Sweden)

    Sajjad Damiri

    2017-12-01

    Full Text Available A seeding strategy was developed in the preparation of cyclotetramethylenetetranitramine (HMX explosive micro-particles by solvent-antisolvent method, to control their polymorphs from dangerous gamma (γ type to the desired and standard beta (β form with the size distribution of <10.0 μm, by using a low concentration of β-HMX fine particles as micro-seed in the antisolvent medium. All products were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM, and dynamic light scattering particle size analyzer. In the next step, the effective factors on the sizes and morphologies of micro-particles in the presence and absence of two soft templates of poly (ethylene glycol-400 (PEG-400 polymer and coconut fatty acid diethanolamide (lauramide surfactant were investigated. The results of experiments showed that using of water-soluble PEG-400 in the low antisolvent temperatures leads to the production of very spherical particles. Also non-ionic surfactant of lauramide, direct the crystal growth to needle-like structures. The advantages of this method are its capability for the simple production of β-HMX micro-particles in the large scale production process, with the various crystal structures and particles size distributions.

  7. Effect of particle size on the glass transition.

    Science.gov (United States)

    Larsen, Ryan J; Zukoski, Charles F

    2011-05-01

    The glass transition temperature of a broad class of molecules is shown to depend on molecular size. This dependency results from the size dependence of the pair potential. A generalized equation of state is used to estimate how the volume fraction at the glass transition depends on the size of the molecule, for rigid molecule glass-formers. The model shows that at a given pressure and temperature there is a size-induced glass transition: For molecules larger than a critical size, the volume fraction required to support the effective pressure due to particle attractions is above that which characterizes the glassy state. This observation establishes the boundary between nanoparticles, which exist in liquid form only as dispersions in low molecular weight solvents and large molecules which form liquids that have viscosities below those characterized by the glassy state.

  8. Effect of particle size on the thermoluminescent response of hydroxyapatite

    International Nuclear Information System (INIS)

    Barrera V, A.; Zarate M, J.; Contreras, M. E.; Rivera M, T.

    2016-10-01

    We present the study of the structural characterization and the thermoluminescent response of the hydroxyapatite as a function of the calcination temperature and the effect of the particle size. For precipitation synthesis, calcium nitrate (Ca(NO 3 ) 2 and dibasic ammonium phosphate ((NH 4 ) 2 HPO 4 ) were used as precursors and ammonium hydroxide (NH 4 OH) as a ph controlling agent. The characterization of the samples was carried out by the techniques of X-ray diffraction, scanning electron microscopy and infrared spectroscopy. The powders obtained are composed of hydroxyapatite, with a different degree of dehydroxylation. The thermoluminescent characterization indicates that at higher calcination temperature there is a higher thermoluminescent response, the calcined powders at 1300 degrees Celsius show a very well defined brightness curve with a higher intensity, with its maximum intensity located at a temperature of 210 degrees Celsius, which indicates that this material can be used as a dosimeter. (Author)

  9. Effects of heavy particle irradiation on central nervous system

    International Nuclear Information System (INIS)

    Nojima, Kumie; Nakadai, Taeko; Khono, Yukio

    2006-01-01

    Effects of low dose heavy particle radiation to central nervous system were studied using human embryonal carcinoma (Ntera2=NT2) and Human neuroblastoma cell (NB1). They exposed to heavy ions and X ray 80% confluent cells in culture bottles. The cells were different type about growth and differentiation in the neuron. The apoptosis profile was measured by AnnexinV-EGFP, PI stained and fluorescence-activated cell sorter (FACS). Memory and learning function of adult mice were studied using water maze test after carbon- or iron-ion irradiation. Memory functions were rapidly decreased after irradiation both ions. Iron -ion group were recovered 20 weeks after irradiation C-ion group were recovered 25 weeks after irradiation. Tier memory were still keep at over 100 weeks after irradiation. (author)

  10. Characterization of Beta-leptinotarsin-h and the Effects of Calcium Flux Antagonists on its Activity

    National Research Council Canada - National Science Library

    Crosland, Richard D; Fitch, Richard W; Hines, Harry B

    2005-01-01

    ...+ influx through presynaptic Ca2+ channels. Analysis of partial amino acid sequences revealed that beta-leptinotarsin-h is a unique protein with significant similarity to only one other protein, the juvenile hormone esterase of Leptinotarsa...

  11. Effect of aerobic exercise on Pancreas Beta-cells function in adult obese males

    Directory of Open Access Journals (Sweden)

    Mojtaba Eizadi

    2014-08-01

    Conclusion: Aerobic exercise training increases beta cells function and decreases FBS in obese men. These findings support the hypothesis that regular physical activity postpones the occurrence of type 2 diabetes in adult obese subjects.

  12. Effects of beta-1,3-glucan from Septoria tritici on structural defence responses in wheat

    DEFF Research Database (Denmark)

    Shetty, N.P.; Jensen, J.D.; Knudsen, A.

    2009-01-01

    The accumulation of the pathogenesis-related (PR) proteins beta-1,3-glucanase and chitinase and structural defence responses were studied in leaves of wheat either resistant or susceptible to the hemibiotrophic pathogen Septoria tritici. Resistance was associated with an early accumulation of beta...... showing the highly localized accumulation of defence proteins in the vicinity of the pathogen. Isoform analysis of beta-1,3-glucanase from the apoplastic fluid revealed that resistance was associated with the accumulation of an endo-beta-1,3-glucanase, previously implicated in defence against pathogens......, and a protein with identity to ADPG pyrophosphatase (92%) and germin-like proteins (93%), which may be involved in cell wall reinforcement. In accordance with this, glycoproteins like extensin were released into the apoplast and callose accumulated to a greater extent in cell walls, whereas lignin...

  13. Effect of long-term transfusion therapy on the glycometabolic status and pancreatic beta cell function in patients with beta Thalassemia major

    Directory of Open Access Journals (Sweden)

    Kamalakshi G Bhat

    2014-01-01

    Full Text Available Background: Diabetes mellitus is a major complication of iron overload in patients with beta thalassemia major. Design: This is a descriptive study conducted in a Tertiary Care Teaching Hospital to analyze beta cell function and insulin resistance, and their relation to iron overload status in beta thalassemia major. Fasting glucose, two-hour post load glucose, fasting insulin, alanine amino transaminase (ALT, and ferritin were used as outcome measures. The homeostatic model assessment (HOMA model was used to calculate the beta cell function and insulin resistance index. Results: Of the 30 cases, 20% had impaired fasting glucose, 3.3% had impaired glucose tolerance, and none had diabetes. Fasting glucose was not significant between the cases and controls (P = 0.113. Fasting insulin (P = 0.001, ferritin (P = 0.001, and ALT (P = 0.001 levels were significantly high in the cases. Insulin resistance index was significantly higher in the cases (P = 0.001 as also the beta cell function (P = 0.001. With increase in age and the number of units transfused there is a decline in beta cell function, fasting insulin, and insulin resistance after attaining the maximum level. This suggests that initial insulin resistance is followed by insulin depletion due to loss of beta cell function, leading to diabetes mellitus. Conclusion: Impaired glucose tolerance (IGT and insulin resistance precede the onset of insulin-dependent diabetes and adequate chelation therapy is essential for delaying the onset or for prevention of diabetes.

  14. Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study.

    Directory of Open Access Journals (Sweden)

    Marina Yazigi Solis

    Full Text Available Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d(-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1 and on cognitive function before and after exercise in trained cyclists (Study 2.In Study 1, seven healthy vegetarians (3 women and 4 men and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation, with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task being performed before and after exercise on each occasion.In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99 or omnivores (p = 0.27; nor was there any effect when data from both groups were pooled (p = 0.19. Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27. In study 2, exercise improved cognitive function across all tests (P 0.05 of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise.28 d of beta-alanine supplementation at 6.4 g d(-1 appeared not to influence brain homocarnosine/carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists.

  15. Energetic particle emission: preequilibrium emission and cooperative effects

    Energy Technology Data Exchange (ETDEWEB)

    Sapienza, P.; Coniglione, R.; Colonna, M.; Migneco, E.; Agodi, C.; Alba, R.; Bellia, G.; Zoppo, A. Del; Finocchiaro, P.; Greco, V.; Loukachine, K.; Maiolino, C.; Piattelli, P.; Santonocito, D. [INFN Lab. Nazionale del Sud, Via A. Doria 44, Catania (Italy); Colonna, N. [INFN, Bari (Italy); Bruno, M.; D Agostino, M.; Mastinu, P.F. [INFN and Dipartimento di Fisica, Bologna (Italy); Gramegna, F. [INFN Laboratorio Nazionale di Legnaro, Padova (Italy); Iori, I.; Fabbietti, L.; Moroni, A. [INFN and Dipartimento di Fisica, Milano (Italy); Margagliotti, G.V.; Milazzo, P.M.; Rui, R.; Vannini, G. [INFN and Dipartimento di Fisica, Trieste (Italy); Blumenfeld, Y.; Scarpaci, J.A. [Institut de Physique Nucleaire, IN2P3CNRS, F91406 Orsay (France)

    2001-09-01

    Full text: The {sup 58} Ni +{sup 58} Ni reaction at 30 A MeV was investigated at Laboratori Nazionale del Sud with the MEDEA and MULTICS apparatus. Energetic protons were detected in coincidence with photons, light charged particles (Z = 1, 2) (LCP) and intermediate and heavy fragments on an event by event basis. Protons with energy extending up to almost 20% of the total available energy, namely much larger than expected by coupling the relative motion with a sharp nucleon Fermi momentum distribution (kinematical limit), were measured in our experiment. We have also investigated the average proton multiplicity as a function of the number of participating nucleons A{sub part} (b) and a striking behavior with increasing energy is found. Indeed, the experimental proton multiplicity (full squares) displays the expected linear dependence on A{sub part} (b) for energy close to the kinematical limit (60 {<=} Ep {<=} 80 MeV), while the multiplicity of extremely energetic protons (130 {<=} Ep {<=} 150 MeV) exhibits an almost quadratic increase with A{sub part}. The comparison with BNV calculations which include the momentum dependence in the effective potential shows that the features of the energetic proton emission are well reproduced up to {approx_equal} 110 MeV while this approach fails to explain the almost quadratic dependence on the number of participant nucleons of the yield of very energetic protons (E{sub p}{sup NN} {>=} 130 MeV). So, the observed behavior calls for the introduction of mechanisms beyond the mean field and two body nucleon-nucleon collisions such as cooperative effects. In conclusions, these results shed some light on the emission of extremely energetic protons and can improve the understanding of the mechanism responsible for deep subthreshold particle production. Moreover, the detailed comparison with dynamical calculations allows to get a deeper insight on the first non equilibrated stage of the reaction where the highest temperatures and

  16. Shape Effect on Particle-Lipid Bilayer Membrane Association, Cellular Uptake, and Cytotoxicity.

    Science.gov (United States)

    Tree-Udom, Thapakorn; Seemork, Jiraporn; Shigyou, Kazuki; Hamada, Tsutomu; Sangphech, Naunpun; Palaga, Tanapat; Insin, Numpon; Pan-In, Porntip; Wanichwecharungruang, Supason

    2015-11-04

    Although computer simulation and cell culture experiments have shown that elongated spherical particles can be taken up into cells more efficiently than spherical particles, experimental investigation on effects of these different shapes over the particle-membrane association has never been reported. Therefore, whether the higher cellular uptake of an elongated spherical particles is a result of a better particle-membrane association as suggested by some calculation works or a consequence of its influence on other cellular trans-membrane components involved in particle translocation process, cannot be concluded. Here, we study the effect of particle shape on the particle-membrane interaction by monitoring the association between particles of various shapes and lipid bilayer membrane of artificial cell-sized liposomes. Among the three shaped lanthanide-doped NaYF4 particles, all with high shape purity and uniformity, similar crystal phase, and surface chemistry, the elongated spherical particle shows the highest level of membrane association, followed by the spherical particle with a similar radius, and the hexagonal prism-shaped particle, respectively. The free energy of membrane curvature calculated based on a membrane indentation induced by a particle association indicates that among the three particle shapes, the elongated spherical particle give the most stable membrane curvature. The elongated spherical particles show the highest cellular uptake into cytosol of human melanoma (A-375) and human liver carcinoma (HepG2) cells when observed through a confocal laser scanning fluorescence microscope. Quantitative study using flow cytometry also gives the same result. The elongated spherical particles also possess the highest cytotoxicity in A-375 and normal skin (WI-38) cell lines, comparing to the other two shaped particles.

  17. Subtype-selective modulation of human beta 1- and beta 2-adrenoceptor function by beta-adrenoceptor agonists and antagonists

    NARCIS (Netherlands)

    Brodde, O. E.; Daul, A.; Michel, M. C.

    1990-01-01

    In healthy volunteers a 14-day treatment with the selective beta 1-adrenoceptor agonist xamoterol (2 x 200 mg/day) desensitized beta 1-adrenoceptor-mediated physiological effects, but did not affect beta 2-adrenoceptor-mediated effects; in contrast, a 9-day treatment with the selective beta

  18. Side effects of Deferasirox Iron Chelation in Patients with Beta Thalassemia Major or Intermedia

    Directory of Open Access Journals (Sweden)

    Murtadha Al-Khabori

    2013-03-01

    Full Text Available Objectives: Chelating agents remain the mainstay in reducing the iron burden and extending patient survival in homozygous beta-thalassemia but adverse and toxic effects may increase with the institution and long term use of this essential therapy. This study aimed to estimate the incidence of deferasirox (DFX side effects in patients with thalassemia major or intermedia.Methods: A retrospective study of 72 patients (mean age: 20.3±0.9 yrs; 36 male, 36 female with thalassemia major or intermedia treated at Sultan Qaboos University Hospital, Oman, was performed to assess the incidence of side effects related to deferasirox over a mean of 16.7 month follow-up period.Results: Six patients experienced rashes and 6 had gastro-intestinal upset. DFX was discontinued in 18 patients for the following reasons: persistent progressive rise(s in serum creatinine (7 patients; 40% mean serum creatinine rise from baseline, feeling unwell (2, severe diarrhea (1, pregnancy (1, death unrelated to chelator (2 and rise in serum transaminases (2. Three patients were reverted to desferoxamine and deferiprone combination therapy as DFX was no longer biochemically effective after 18 months of therapy. There was no correlation between baseline serum ferritin and serum creatinine or a rise in serum creatinine. Cardiac MRI T2* did not change with DFX therapy. However, there was an improvement in liver MRI T2* (p=0.013.Conclusion: Renal side effects related to deferasirox appear to be higher than those reported in published clinical trials. Further larger studies are required to confirm these findings.

  19. Effects of oil dispersants on settling of marine sediment particles and particle-facilitated distribution and transport of oil components.

    Science.gov (United States)

    Cai, Zhengqing; Fu, Jie; Liu, Wen; Fu, Kunming; O'Reilly, S E; Zhao, Dongye

    2017-01-15

    This work investigated effects of three model oil dispersants (Corexit EC9527A, Corexit EC9500A and SPC1000) on settling of fine sediment particles and particle-facilitated distribution and transport of oil components in sediment-seawater systems. All three dispersants enhanced settling of sediment particles. The nonionic surfactants (Tween 80 and Tween 85) play key roles in promoting particle aggregation. Yet, the effects varied with environmental factors (pH, salinity, DOM, and temperature). Strongest dispersant effect was observed at neutral or alkaline pH and in salinity range of 0-3.5wt%. The presence of water accommodated oil and dispersed oil accelerated settling of the particles. Total petroleum hydrocarbons in the sediment phase were increased from 6.9% to 90.1% in the presence of Corexit EC9527A, and from 11.4% to 86.7% for PAHs. The information is useful for understanding roles of oil dispersants in formation of oil-sediment aggregates and in sediment-facilitated transport of oil and PAHs in marine eco-systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. [Particle pollution effects on the risk of cardiovascular diseases].

    Science.gov (United States)

    Massamba, V K; Coppieters, Y; Mercier, G; Collart, P; Levêque, A

    2014-02-01

    The effects of air pollution on health are quite well-documented and the influence of particulate pollution on morbidity and mortality from myocardial infarction and stroke is increasingly evident. The objective of this literature review is to identify and synthesize articles on the impact of air pollution by PM10 and PM2.5 of myocardial infarction and stroke. A total of 14 studies were reported on the effects of PM10 and five on the effects of PM2.5. Nine out of 14 studies for PM10 and two studies of five for PM2.5 have found a significant association with myocardial infarction and/or stroke. Particle composition according to location, study period and population must be considered in interpreting the results on the health effects of air pollution. The integration of these elements is important for decision making in tune with social and economic conditions specific to each environment. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  1. Metabolism of sitosteryl beta-D-glucoside and its nutritional effects in rats

    Energy Technology Data Exchange (ETDEWEB)

    Weber, N.

    1988-01-01

    (4-14C)Sitosteryl beta-D-glucoside, intragastrically administered to rats, was not absorbed by the intestinal mucosa. At three hr after the application, radioactivity was concentrated almost exclusively in the digesta of stomach, small intestine as well as cecum and colon, whereas only low proportions of radioactively labeled compounds were found in the various tissues of the gastrointestinal tract. Minor proportions of labeled metabolites of (4-14C)sitosteryl beta-D-glucoside, such as sitosterol and sitosteryl esters, were formed in the small intestine in vivo and in slices of small intestine in vitro. In the tissues of cecum and colon as well as the digesta derived from them, high proportions of labeled coprositostanol, i.e. 24 alpha-ethyl-5 beta-cholestan-3 beta-ol, that obviously had been formed by bacterial degradation of the substrate were detected. The feeding of sitosteryl beta-D-glucoside (0.5 g/kg body weight X day) over a period of four weeks did not alter significantly body weights or organ weights of rats. Analyses of steryl lipids of the various organs and tissues confirmed the findings obtained with the radioactive substrate: neither sitosteryl beta-D-glucoside nor sitosterol or sitosteryl esters derived therefrom had been transported in appreciable amounts to organs and tissues outside the alimentary canal during the feeding period. Minor proportions of unmetabolized sitosteryl beta-D-glucoside were detected in the tissues of stomach and intestine, whereas large proportions of the substrate were found in feces of rats that had received the sitosteryl beta-D-glucoside-containing diet; coprositostanol was found in feces of these animals in high proportions as well.

  2. Ultraviolet (UV) disinfection of grey water: particle size effects.

    Science.gov (United States)

    Winward, G P; Avery, L M; Stephenson, T; Jefferson, B

    2008-02-01

    The impact of water quality on the ultraviolet (UV) disinfection of grey water was investigated with reference to urban water reuse. Direct UV disinfection of grey water did not meet the stringent California State Title 22 criteria for unrestricted urban water reuse due to the presence of particulate material ranging from or = 2000 microm in size. Grey water was manipulated by settling to produce fractions of varying particle size distributions and blending was employed post-disinfection to extract particle-associated coliforms (PACs). The efficacy of UV disinfection was found to be linked to the particle size of the grey water fractions. The larger particle size fractions with a mean particle size of 262 microm and above were observed to shield more coliforms from UV light than did the smaller particles with a mean particle size below 119 microm. Up to 70% of total coliforms in the larger particle size fractions were particle-associated following a UV dose (fluence) of 260 mJ.cm(-2) and would remain undetected by standard coliform enumeration techniques. Implications for urban water reuse are discussed and recommendations made for grey water treatment to ensure removal of particle-associated indicator bacteria and pathogens prior to UV disinfection.

  3. Inhibitory effect of different product analogues on {beta}-alanine synthase: A thermodynamic and fluorescence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Andujar-Sanchez, Montserrat; Martinez-Gomez, Ana Isabel; Martinez-Rodriguez, Sergio; Clemente-Jimenez, Josefa Maria; Heras-Vazquez, Francisco Javier Las; Rodriguez-Vico, Felipe [Departamento de Quimica Fisica, Bioquimica y Quimica Inorganica, Facultad de Ciencias Experimentales, Universidad de Almeria, Carretera de Sacramento s/n, La Canada de San Urbano, Almeria 04120 (Spain); Jara-Perez, Vicente [Departamento de Quimica Fisica, Bioquimica y Quimica Inorganica, Facultad de Ciencias Experimentales, Universidad de Almeria, Carretera de Sacramento s/n, La Canada de San Urbano, Almeria 04120 (Spain)], E-mail: vjara@ual.es

    2009-02-15

    The enzyme N-carbamoyl-{beta}-alanine amidohydrolase catalyse the hydrolysis of N-carbamoyl-{beta}-alanine or N-carbamoyl-{beta}-aminoisobutyric acid to {beta}-alanine or 3-aminoisobutyric acid, under the release of carbon-dioxide and ammonia. This work studies the inhibition of N-carbamoyl-{beta}-alanine amidohydrolase from Agrobacterium tumefaciens C58 (At{beta}car) by different carboxylic acid compounds that differ in number of carbons, and position and size of ramification, while the binding thermodynamics of the inhibitors are studied by isothermal titration calorimetry (ITC) and fluorescence. From the binding constants and inhibition studies, we conclude that propionate is the most efficient inhibitor among those tested. Substitution of the linear alkyl acids in positions 2 and 3 resulted in a drastic decrease of the affinity. The thermodynamic parameters show that a conformational change is triggered upon ligand binding. Binding enthalpy {delta}H{sub b} is negative in all cases for all ligands, and thus, Van der Waals interactions and hydrogen bonding are most probably the major sources for this term. The process is entropically favoured at all temperatures and pH studied, most probably due to the liberation of water molecules accompanying the conformational change of the enzyme.

  4. Effects of digestion protocols on the isolation and characterization of metal-metal wear particles. I. Analysis of particle size and shape.

    Science.gov (United States)

    Catelas, I; Bobyn, J D; Medley, J B; Krygier, J J; Zukor, D J; Petit, A; Huk, O L

    2001-06-05

    Isolation of metal wear particles from hip simulator lubricants or tissues surrounding implants is a challenging problem because of small particle size, their tendency to agglomerate, and their potential for chemical degradation by digestion reagents. To provide realistic measurements of size, shape, and composition of metal wear particles, it is important to optimize particle isolation and minimize particle changes due to the effects of the reagents. In this study (Part I of II), transmission electron microscopy (TEM) was used to examine and compare the effects of different isolation protocols, using enzymes or alkaline solutions, on the size and shape of three different types of cobalt-based alloy particles produced from metal-metal bearings. The effect on particle composition was examined in a subsequent study (Part II). Large particles (particles (particle size and to a lesser extent particle shape. For both large particles and small particles generated in water, the changes in size were more extensive after alkaline than after enzymatic protocols and increased with alkaline concentration and time in solution, up to twofold at 2 h and threefold at 48 h. However, when isolating particles from 95% serum, an initial protective effect of serum proteins and/or lipids was observed. Because of this protective effect, there was no significant difference in particle size and shape for both oval and needle-shaped particles after 2 h in 2N KOH and after enzymatic treatments. However, round particles were significantly smaller after 2 h in 2N KOH than after enzymatic treatments. Particle composition may also have been affected by the 2N KOH treatment, as suggested by a difference in particle contrast under TEM, an issue examined in detail in Part II. Copyright 2001 John Wiley & Sons, Inc. J Biomed Mater Res 55: 320-329, 2001

  5. Effects of beta-hydroxybutyrate and isoproterenol on lipolysis in isolated adipocytes from periparturient dairy cows and cows with clinical ketosis

    NARCIS (Netherlands)

    van der Drift, S. G. A.; Everts, R. R.; Houweling, M.; van Leengoed, L. A. M. G.; Stegeman, J. A.; Tielens, A. G. M.; Jorritsma, R.

    An in vitro model was used to investigate effects of beta-hydroxybutyrate and isoproterenol (beta-adrenergic receptor agonist) on lipolysis in isolated adipocytes from late pregnant and recently calved dairy cows (n = 5) and cows with clinical ketosis (n =3). Incubation with 3.0 mmol/L

  6. Role of TGF-beta1 and MAP kinases in the antiproliferative effect of aspirin in human vascular smooth muscle cells.

    Directory of Open Access Journals (Sweden)

    Santiago Redondo

    2010-03-01

    Full Text Available We aimed to test the antiproliferative effect of acetylsalicylic acid (ASA on vascular smooth muscle cells (VSMC from bypass surgery patients and the role of transforming growth factor beta 1 (TGF-beta1.VSMC were isolated from remaining internal mammary artery from patients who underwent bypass surgery. Cell proliferation and DNA fragmentation were assessed by ELISA. Protein expression was assessed by Western blot. ASA inhibited BrdU incorporation at 2 mM. Anti-TGF-beta1 was able to reverse this effect. ASA (2 mM induced TGF-beta1 secretion; however it was unable to induce Smad activation. ASA increased p38(MAPK phosphorylation in a TGF-beta1-independent manner. Anti-CD105 (endoglin was unable to reverse the antiproliferative effect of ASA. Pre-surgical serum levels of TGF-beta1 in patients who took at antiplatelet doses ASA were assessed by ELISA and remained unchanged.In vitro antiproliferative effects of aspirin (at antiinflammatory concentration on human VSMC obtained from bypass patients are mediated by TGF-beta1 and p38(MAPK. Pre-surgical serum levels of TGF- beta1 from bypass patients who took aspirin at antiplatelet doses did not change.

  7. Beta-cell function, incretin effect, and incretin hormones in obese youth along the span of glucose tolerance from normal to prediabetes to Type 2 diabetes

    Science.gov (United States)

    Using the hyperglycemic and euglycemic clamp, we demonstrated impaired Beta-cell function in obese youth with increasing dysglycemia. Herein we describe oral glucose tolerance test (OGTT)-modeled Beta-cell function and incretin effect in obese adolescents spanning the range of glucose tolerance. Bet...

  8. ICI 182,780 has agonistic effects and synergizes with estradiol-17 beta in fish liver, but not in testis

    Directory of Open Access Journals (Sweden)

    Power Deborah M

    2006-12-01

    Full Text Available Abstract Background ICI 182,780 (ICI belongs to a new class of antiestrogens developed to be pure estrogen antagonists and, in addition to its therapeutic use, it has been used to knock-out estrogen and estrogen receptor (ER actions in several mammalian species. In the present study, the effects and mechanism of action of ICI were investigated in the teleost fish, sea bream (Sparus auratus. Methods Three independent in vivo experiments were performed in which mature male tilapia (Oreochromis mossambicus or sea bream received intra-peritoneal implants containing estradiol-17 beta (E2, ICI or a combination of both compounds. The effects of E2 and ICI on plasma calcium levels were measured and hepatic and testicular gene expression of the three ER subtypes, ER alpha, ER beta a and ER beta b, and the estrogen-responsive genes, vitellogenin II and choriogenin L, were analyzed by semi-quantitative RT-PCR in sea bream. Results E2 treatment caused an increase in calcium levels in tilapia, while ICI alone had no noticeable effect, as expected. However, pretreatment with ICI synergistically potentiated the effect of E2 on plasma calcium in both species. ICI mimicked some E2 actions in gene expression in sea bream liver upregulating ER alpha, vitellogenin II and choriogenin L, although, unlike E2, it did not downregulate ER beta a and ER beta b. In contrast, no effects of E2 or ICI alone were detected in the expression of ERs in testis, while vitellogenin II and choriogenin L were upregulated by E2 but not ICI. Finally, pretreatment with ICI had a synergistic effect on the hepatic E2 down-regulation of ER beta b, but apparently blocked the ER alpha up-regulation by E2. Conclusion These results demonstrate that ICI has agonistic effects on several typical estrogenic responses in fish, but its actions are tissue-specific. The mechanisms for the ICI agonistic activity are still unknown; although the ICI induced up-regulation of ER alpha mRNA could be one of

  9. Effects of beta-carotene supplementation on adipose tissue thermogenic capacity in ferrets (Mustela putorius furo).

    Science.gov (United States)

    Sánchez, Juana; Fuster, Antonia; Oliver, Paula; Palou, Andreu; Picó, Catalina

    2009-12-01

    We previously described that the intake of pharmacological doses of beta-carotene (BC) resulted in higher body weight gain in the ferret (Mustela putorius furo), an animal model that resembles human subjects in terms of intestinal BC absorption and metabolism. These results were some way unexpected considering the condition of BC as a vitamin A precursor and the previous data in rodents showing these compounds as thermogenic activators. Here, we aimed to characterise in the ferret whether the mentioned changes in body weight could be explained by changes in adipose tissue thermogenic capacity. We studied the effects of 6-month supplementation with BC (0.8 and 3.2 mg/kg per d) on adipose tissue morphology and uncoupling protein-1 (UCP1) content. BC supplementation resulted in higher body weight (the high dose), induced depot- and dose-dependent hypertrophy of white adipocytes, decreased the amount of brown-like multilocular adipocytes in the retroperitoneal depot and decreased UCP1 content in different fat depots. To ascertain whether BC effects could be mediated by retinoic acid (RA), 1 week supplementation with RA (0.25 and 25 mg/kg per d) was also studied. RA treatment resulted in a slight decrease in adiposity, decreased cell lipid accumulation and increased UCP1 content, suggesting that the effects of BC on thermogenic capacity are not through RA. In conclusion, RA, but not BC, may have in the ferret comparable effects with those described in rodents, whereas differences concerning BC and RA treatments may be attributable to the different BC metabolism in the present animal model with a lower conversion of BC to RA compared with rodents.

  10. Joint Effect of Particle Charge and Adsorbable Foreign Gases on Vapor Condensation on Fine Aerosol Particles

    Czech Academy of Sciences Publication Activity Database

    Levdansky, V.V.; Smolík, Jiří; Moravec, Pavel

    2008-01-01

    Roč. 35, č. 10 (2008), s. 1246-1248 ISSN 0735-1933 R&D Projects: GA AV ČR(CZ) IAA400720804 Institutional research plan: CEZ:AV0Z40720504 Keywords : charged particle * adsorption * condensation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.332, year: 2008

  11. Understanding particle size and distance driven competition of interparticle interactions and effective single-particle anisotropy

    Czech Academy of Sciences Publication Activity Database

    Pacáková, Barbara; Mantlíková, Alice; Nižňanský, D.; Kubíčková, Simona; Vejpravová, Jana

    2016-01-01

    Roč. 28, č. 20 (2016), 1-11, č. článku 206004. ISSN 0953-8984 R&D Projects: GA ČR(CZ) GA15-01953S Institutional support: RVO:68378271 Keywords : magnetic nanoparticles * single-particle anisotropy * dipolar energy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.649, year: 2016

  12. Genetic effects analysis of myeloid leukemia factor 2 and T cell receptor-beta on resistance to coccidiosis in chickens.

    Science.gov (United States)

    Kim, E-S; Hong, Y H; Lillehoj, H S

    2010-01-01

    Associations between the parameters of resistance to coccidiosis and SNP in 3 candidate genes located on chromosome 1 [T cell receptor-beta (TCR-beta), myeloid leukemia factor 2 (MLF2), and lymphotactin] were determined. Single nucleotide polymorphisms were genotyped in 24 F1 generation and 290 F2 generation birds. Four SNP were identified in the lymphotactin gene, 12 were located in the TCR-beta gene, and 4 in the MLF2 gene. At various times after experimental infection of the F2 generation with Eimeria maxima, BW, fecal oocyst shedding, and biochemical parameters were measured as parameters of coccidiosis resistance. Single marker association test was applied to determine the associations between the 20 SNP and the parameters of coccidiosis resistance. The maximum additive genetic effect on disease resistance of an SNP in MLF2 was explained by BW (P = 0.0002). The SNP in MLF2 significantly associated with BW was also associated with fecal oocyst shedding (P = 0.001). Four SNP associated with oocyst shedding were found within the coding region of TCR-beta (P coccidiosis resistance in chickens.

  13. Effect of transforming growth factor-beta1 on embryonic and posthatch muscle growth and development in normal and low score normal chicken.

    Science.gov (United States)

    Li, X; Velleman, S G

    2009-02-01

    During skeletal muscle development, transforming growth factor-beta1 (TGF-beta1) is a potent inhibitor of muscle cell proliferation and differentiation. The TGF-beta1 signal is carried by Smad proteins into the cell nucleus, inhibiting the expression of key myogenic regulatory factors including MyoD and myogenin. However, the molecular mechanism by which TGF-beta1 inhibits muscle cell proliferation and differentiation has not been well documented in vivo. The present study investigated the effect of TGF-beta1 on in vivo skeletal muscle growth and development. A chicken line, Low Score Normal (LSN) with reduced muscling and upregulated TGF-beta1 expression, was used and compared to a normal chicken line. The injection of TGF-beta1 at embryonic day (ED) 3 significantly reduced the pectoralis major (p. major) muscle weight in the normal birds at 1 wk posthatch, whereas no significant difference was observed in the LSN birds. The difference between normal and LSN birds in response to TGF-beta1 is likely due to different levels of endogenous TGF-beta1 where the LSN birds have increased TGF-beta1 expression in their p. major muscle at both 17 ED and 6 wk posthatch. Smad3 expression was reduced by TGF-beta1 from 10 ED to 1 wk posthatch in normal p. major muscle. Unlike Smad3, Smad7 expression was not significantly affected by TGF-beta1 until posthatch in both normal and LSN p. major muscle. Expression of MyoD was reduced 35% by TGF-beta1 during embryonic development in normal p. major muscle, whereas LSN p. major muscle showed a delayed decrease at 1 d posthatch in MyoD expression in response to the TGF-beta1 treatment. Myogenin expression was reduced 29% by TGF-beta1 after hatch in normal p. major muscle. In LSN p. major muscle, TGF-beta1 treatment significantly decreased myogenin expression by 43% at 1 d posthatch and 32% at 1 wk posthatch. These data suggested that TGF-beta1 reduced p. major muscle growth by inhibiting MyoD and myogenin expression during both embryonic

  14. Nonlinear effects of energetic particle driven instabilities in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Bruedgam, Michael

    2010-03-25

    In a tokamak plasma, a population of superthermal particles generated by heating methods can lead to a destabilization of various MHD modes. Due to nonlinear wave-particle interactions, a consequential fast particle redistribution reduces the plasma heating and can cause severe damages to the wall of the fusion device. In order to describe the wave-particle interaction, the drift-kinetic perturbative HAGIS code is applied which evolves the particle trajectories and the waves nonlinearly. For a simulation speed-up, the 6-d particle phase-space is reduced by the guiding centre approach to a 5-d description. The eigenfunction of the wave is assumed to be invariant, but its amplitude and phase is altered in time. A sophisticated {delta}/f-method is employed to model the change in the fast particle distribution so that numerical noise and the excessive number of simulated Monte-Carlo points are reduced significantly. The original code can only calculate the particle redistribution inside the plasma region. Therefore, a code extension has been developed during this thesis which enlarges the simulation region up to the vessel wall. By means of numerical simulations, this thesis addresses the problem of nonlinear waveparticle interactions in the presence of multiple MHD modes with significantly different eigenfrequencies and the corresponding fast particle transport inside the plasma. In this context, a new coupling mechanism between resonant particles and waves has been identified that leads to enhanced mode amplitudes and fast particle losses. The extension of the code provides for the first time the possibility of a quantitative and qualitative comparison between simulation results and recent measurements in the experiment. The findings of the comparison serve as a validation of both the theoretical model and the interpretation of the experimental results. Thus, a powerful interface tool has been developed for a deeper insight of nonlinear wave-particle interaction

  15. Slow cortical potential and theta/beta neurofeedback training in adults: effects on attentional processes, and motor system excitability

    Directory of Open Access Journals (Sweden)

    Petra eStuder

    2014-07-01

    Full Text Available Neurofeedback (NF is being successfully applied, among others, in children with ADHD and as a peak performance training in healthy subjects. However, the neuronal mechanisms mediating a successful NF training have not yet been sufficiently uncovered for both theta/beta (T/B, and slow cortical potential (SCP training, two protocols established in NF in ADHD. In the present randomized controlled investigation in adults without a clinical diagnosis (n = 59, the specificity of the effects of these two NF protocols on attentional processes, and motor system excitability were to be examined, focusing on the underlying neuronal mechanisms. NF training consisted of 10 double sessions, and self-regulation skills were analyzed. Pre- and post-training assessments encompassed performance and event-related potential measures during an attention task, and motor system excitability assessed by transcranial magnetic stimulation. Some NF protocol specific effects have been obtained. However, due to the limited sample size medium effects didn’t reach the level of significance. Self-regulation abilities during negativity trials of the SCP training were associated with increased contingent negative variation amplitudes, indicating improved resource allocation during cognitive preparation. Theta/beta training was associated with increased response speed and decreased target-P3 amplitudes after successful theta/beta regulation suggested reduced attentional resources necessary for stimulus evaluation. Motor system excitability effects after theta/beta training paralleled the effects of methylphenidate. Overall, our results are limited by the non-sufficiently acquired self-regulation skills, but some specific effects between good and poor learners could be described. Future studies with larger sample sizes and sufficient acquisition of self-regulation skills are needed to further evaluate the protocol specific effects on attention and motor system excitability

  16. Effects of continuous and interrupted orthodontic force on interleukin-1beta and prostaglandin E2 production in gingival crevicular fluid.

    Science.gov (United States)

    Lee, Kee-Joon; Park, Young-Chel; Yu, Hyung-Seog; Choi, Seong-Ho; Yoo, Yun-Jung

    2004-02-01

    The purpose of this study was to evaluate the effects of a light continuous force and an interrupted force with weekly reactivation on interleukin-1beta (IL-1beta) and prostaglandin E(2) (PGE(2)); possible interactions between these 2 potent mediators of the bone resorption process were assessed in vivo. Ten healthy young adults (mean age 20.6 years, 2 men, 8 women) with 4 premolars extracted were assessed. In each subject, 1 maxillary canine (E1) received continuous force with a nickel-titanium coil spring. The opposite canine (E2) received an interrupted force with a screw-attached retractor; the force was reactivated weekly by 2 turns of the screw. An antagonistic canine was used as a control. Gingival crevicular fluid was collected from the distal side of each tooth, 10 times in 3 weeks, and IL-1beta and PGE(2) levels were measured. For E1, the IL-1beta level showed a significant elevation at 24 hours and then decreased and maintained an insignificant but high mean concentration, compared with the control site. The PGE(2) level showed a significant elevation at 24 hours and then decreased. For E2, a significant elevation of IL-1beta level was observed at 24 hours and a greater significant elevation at 24 hours after the first reactivation, compared with the control sites. The PGE(2) level increased significantly at 24 hours and remained high for 1 week. The synergistic up-regulation of PGE(2) by appliance reactivation and secreted IL-1beta was not evident with either type of force after 1 week. Both experimental sites showed significant tooth movement compared with the control sites at 3 weeks; however, there was no significant difference between the 2 experimental sites. A well-controlled mechanical stress with timely reactivation can effectively upregulate IL-1beta secretion, but there might be limitations in increasing the mediator levels, because of the feedback mechanisms in vivo. In addition, the analysis of crevicular fluid is a useful method for

  17. Space Weather Effects Produced by the Ring Current Particles

    Science.gov (United States)

    Ganushkina, Natalia; Jaynes, Allison; Liemohn, Michael

    2017-11-01

    One of the definitions of space weather describes it as the time-varying space environment that may be hazardous to technological systems in space and/or on the ground and/or endanger human health or life. The ring current has its contributions to space weather effects, both in terms of particles, ions and electrons, which constitute it, and magnetic and electric fields produced and modified by it at the ground and in space. We address the main aspects of the space weather effects from the ring current starting with brief review of ring current discovery and physical processes and the Dst-index and predictions of the ring current and storm occurrence based on it. Special attention is paid to the effects on satellites produced by the ring current electrons. The ring current is responsible for several processes in the other inner magnetosphere populations, such as the plasmasphere and radiation belts which is also described. Finally, we discuss the ring current influence on the ionosphere and the generation of geomagnetically induced currents (GIC).

  18. Effects of inspiratory resistance, inhaled beta-agonists and histamine on canine tracheal blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, W.T.; Baile, E.M.; Brancatisano, A.; Pare, P.D.; Engel, L.A. (Dept. of Respiratory Medicine, Westmead Hospital, Westmead, NSW (Australia))

    1992-01-01

    Tracheobronchial blood flow is potentially important in asthma as it could either influence the clearance of mediators form the airways, thus affecting the duration and severity of bronchoispasm, or enhance oedema formation with a resultant increase in airflow obstruction. In anaesthetized dogs, spontaneously breathing via a tracheostomy, we investigated the effects of three interventions which are relevant to acute asthma attacks and could potentially influence blood flow and its distribution to the mucosa and remaining tissues of the trachea: (1) increased negative intrathoracic pressure swings (-25[+-]1 cmH[sub 2]O) induced by an inspiratory resistance; (2) variable inhaled doses of a beta-adrenoceptor-agonist (terbutaline); and (3) aerosolized histamine sufficient to produce a threefold increase in pulmonary resistance. Microspheres labelled with different radioisotopes were used to measure blood flow. Resistive breathing did not influence tracheobronchial blood flow. Following a large dose of terbutaline, mucosal blood flow (Qmb) increased by 50%. After inhaled histamine, Qmb reached 265% of the baseline value. We conclude that, whereas increased negative pressure swings do not influence tracheobronchial blood flow or its distribution, inhalation of aerosolized terbutaline, corresponding to a conventionally nebulized dose, increases mucosal blood flow. Our results also confirm that inhaled histamine, in a dose sufficient to produce moderate bronchoconstriction, increases tracheal mucosal blood flow in the area of deposition. (au).

  19. Effects of zinc toxicity on sugar beet (Beta vulgaris L.) plants grown in hydroponics.

    Science.gov (United States)

    Sagardoy, R; Morales, F; López-Millán, A-F; Abadía, A; Abadía, J

    2009-05-01

    The effects of high Zn concentration were investigated in sugar beet (Beta vulgaris L.) plants grown in a controlled environment in hydroponics. High concentrations of Zn sulphate in the nutrient solution (50, 100 and 300 microm) decreased root and shoot fresh and dry mass, and increased root/shoot ratios, when compared to control conditions (1.2 microm Zn). Plants grown with excess Zn had inward-rolled leaf edges and a damaged and brownish root system, with short lateral roots. High Zn decreased N, Mg, K and Mn concentrations in all plant parts, whereas P and Ca concentrations increased, but only in shoots. Leaves of plants treated with 50 and 100 microm Zn developed symptoms of Fe deficiency, including decreases in Fe, chlorophyll and carotenoid concentrations, increases in carotenoid/chlorophyll and chlorophyll a/b ratios and de-epoxidation of violaxanthin cycle pigments. Plants grown with 300 microm Zn had decreased photosystem II efficiency and further growth decreases but did not have leaf Fe deficiency symptoms. Leaf Zn concentrations of plants grown with excess Zn were high but fairly constant (230-260 microg.g(-1) dry weight), whereas total Zn uptake per plant decreased markedly with high Zn supply. These data indicate that sugar beet could be a good model to investigate Zn homeostasis mechanisms in plants, but is not an efficient species for Zn phytoremediation.

  20. Effects of inspiratory resistance, inhaled beta-agonists and histamine on canine tracheal blood flow

    International Nuclear Information System (INIS)

    Kelly, W.T.; Baile, E.M.; Brancatisano, A.; Pare, P.D.; Engel, L.A.

    1992-01-01

    Tracheobronchial blood flow is potentially important in asthma as it could either influence the clearance of mediators form the airways, thus affecting the duration and severity of bronchoispasm, or enhance oedema formation with a resultant increase in airflow obstruction. In anaesthetized dogs, spontaneously breathing via a tracheostomy, we investigated the effects of three interventions which are relevant to acute asthma attacks and could potentially influence blood flow and its distribution to the mucosa and remaining tissues of the trachea: 1) increased negative intrathoracic pressure swings (-25±1 cmH 2 O) induced by an inspiratory resistance; 2) variable inhaled doses of a beta-adrenoceptor-agonist (terbutaline); and 3) aerosolized histamine sufficient to produce a threefold increase in pulmonary resistance. Microspheres labelled with different radioisotopes were used to measure blood flow. Resistive breathing did not influence tracheobronchial blood flow. Following a large dose of terbutaline, mucosal blood flow (Qmb) increased by 50%. After inhaled histamine, Qmb reached 265% of the baseline value. We conclude that, whereas increased negative pressure swings do not influence tracheobronchial blood flow or its distribution, inhalation of aerosolized terbutaline, corresponding to a conventionally nebulized dose, increases mucosal blood flow. Our results also confirm that inhaled histamine, in a dose sufficient to produce moderate bronchoconstriction, increases tracheal mucosal blood flow in the area of deposition. (au)

  1. Investigation on the effects of beta and gamma irradiation on conducting polymers for sensor applications

    Science.gov (United States)

    Kane, Marie C.; Lascola, Robert J.; Clark, Elliot A.

    2010-12-01

    Two conductive polymers were evaluated to be the active materials in a sensor device for the detection of beta radiation. This was accomplished by characterizing the changes in conductivity of electrically conducting polymer films caused by exposure to tritium gas for varying lengths of time. The behavior of these materials when exposed to gamma radiation was also studied to gain further insight into the mechanism of conductivity degradation by ionizing radiation. Two types of conductive polymer, polyaniline (PANi) and poly(3,4-ethylenedioxythiophene) (PEDOT), were chosen as candidate materials for their widespread commercial use. The change of surface resistance (conductivity) of PANi and PEDOT films when exposed to gamma radiation in both air and deuterium environments was evaluated as well as tritium exposures in 10 4 and 10 5 Pa gas. Raman and absorbance spectra of gamma irradiated samples were obtained to determine the mechanism of conductivity degradation in both polymers. Post-irradiation gas analysis of the samples contained in deuterium revealed very little (or no) hydrogen in the containment vessel, indicating that hydrogen-deuterium isotopic exchange was not responsible for the decrease in surface conductivity due to gamma exposure. The effects of irradiation-induced oxidation were also studied for both conductive polymers during gamma irradiation. It was concluded that chain scission via free radical formation and chain cross-linking are most likely the two dominant mechanisms for conductivity change and not de-protonation of the polymer.

  2. The effects of beta acids from hops (Humulus lupulus) on mortality of Varroa destructor (Acari: Varroidae).

    Science.gov (United States)

    Degrandi-Hoffman, Gloria; Ahumada, Fabiana; Probasco, Gene; Schantz, Lloyd

    2012-12-01

    Hop (Humulus lupulus L.) beta acids (HBA) were tested for miticidal effects on varroa destructor Anderson and Trueman, a parasitic mite of the honey bee (Apis mellifera L.). When varroa were placed on bees that had topical applications of 1 % HBA, there was 100 % mite mortality. Bee mortality was unaffected. Cardboard strips saturated with HBA and placed in colonies resulted in mite drop that was significantly greater than in untreated hives. HBA was detected on about 60 % of the bees in colonies during the first 48 h after application. Mite drop in colonies lasted for about 7 days with the highest drop occurring in the first 2-3 days after treatment. There was a reduction in the percentages of bees with HBA and in the amounts on their bodies after 7 days. Bee and queen mortality in the colonies were not affected by HBA treatments. When cardboard strips saturated with HBA were put in packages of bees, more than 90 % of the mites were killed without an increase in bee mortality. HBA might have potential to control varroa when establishing colonies from packages or during broodless periods.

  3. Kinetics of beta2-microglobulin and phosphate during hemodialysis: effects of treatment frequency and duration.

    Science.gov (United States)

    Leypoldt, John K

    2005-01-01

    Current understanding of beta2-microglobulin (beta2M) and phosphate (or inorganic phosphorus) kinetics during hemodialysis is reviewed. The postdialysis:predialysis concentration ratio for beta2M is determined by dialyzer clearance for beta2M, treatment time, patient body size (specifically, extracellular fluid volume), and total ultrafiltration volume during the treatment. Evaluation of these treatment parameters can be used to calculate dialyzer clearance for beta2M; however, such calculated values are only approximations, since they neglect intradialytic generation, nonrenal (nondialyzer) clearance, and postdialysis rebound of beta2M. The detailed kinetics of beta2M during hemodialysis are best described using a two-compartment model. Theoretical predictions from such two-compartment models suggest that the product of dialyzer clearance for beta2M and weekly treatment duration, independent of treatment frequency, is the main determinant of plasma beta2M concentrations. The kinetics of phosphate removal during hemodialysis are incompletely understood. Phosphate is removed from both extracellular and intracellular compartments during hemodialysis; the plasma phosphate concentration levels off after the first 1 or 2 hours of treatment and plasma concentrations can rebound even before therapy is complete. Increases in dialyzer clearance of phosphate have been previously achieved only by increasing dialysis membrane surface area or by the use of hemodiafiltration. A four-compartment model of phosphate kinetics proposed recently by Spalding et al. suggests that the major barrier to phosphate removal is limited transfer of phosphate between the intracellular and extracellular compartments, although other complex factors also play important roles. Theoretical predictions using the model of Spalding et al. suggest that increasing either treatment frequency or treatment duration can increase phosphate removal. The kinetics of beta2M are representative of middle molecules

  4. Minor long-term changes in weight have beneficial effects on insulin sensitivity and beta-cell function in obese subjects

    DEFF Research Database (Denmark)

    Rosenfalck, A M; Hendel, Helle Westergren; Rasmussen, M H

    2002-01-01

    To evaluate the long-term effect of changes in body composition induced by weight loss on insulin sensitivity (SI), non-insulin mediated glucose disposal, glucose effectiveness (SG)and beta-cell function....

  5. Additive effects of beta-alanine and sodium bicarbonate on upper-body intermittent performance.

    Science.gov (United States)

    Tobias, Gabriel; Benatti, Fabiana Braga; de Salles Painelli, Vitor; Roschel, Hamilton; Gualano, Bruno; Sale, Craig; Harris, Roger C; Lancha, Antonio Herbert; Artioli, Guilherme Gianinni

    2013-08-01

    We examined the isolated and combined effects of beta-alanine (BA) and sodium bicarbonate (SB) on high-intensity intermittent upper-body performance in judo and jiu-jitsu competitors. 37 athletes were assigned to one of four groups: (1) placebo (PL)+PL; (2) BA+PL; (3) PL+SB or (4) BA+SB. BA or dextrose (placebo) (6.4 g day⁻¹) was ingested for 4 weeks and 500 mg kg⁻¹ BM of SB or calcium carbonate (placebo) was ingested for 7 days during the 4th week. Before and after 4 weeks of supplementation, the athletes completed four 30-s upper-body Wingate tests, separated by 3 min. Blood lactate was determined at rest, immediately after and 5 min after the 4th exercise bout, with perceived exertion reported immediately after the 4th bout. BA and SB alone increased the total work done in +7 and 8 %, respectively. The co-ingestion resulted in an additive effect (+14 %, p < 0.05 vs. BA and SB alone). BA alone significantly improved mean power in the 2nd and 3rd bouts and tended to improve the 4th bout. SB alone significantly improved mean power in the 4th bout and tended to improve in the 2nd and 3rd bouts. BA+SB enhanced mean power in all four bouts. PL+PL did not elicit any alteration on mean and peak power. Post-exercise blood lactate increased with all treatments except with PL+PL. Only BA+SB resulted in lower ratings of perceived exertion (p = 0.05). Chronic BA and SB supplementation alone equally enhanced high-intensity intermittent upper-body performance in well-trained athletes. Combined BA and SB promoted a clear additive ergogenic effect.

  6. Neutrinoless double beta decay in chiral effective field theory: lepton number violation at dimension seven

    Science.gov (United States)

    Cirigliano, V.; Dekens, W.; de Vries, J.; Graesser, M. L.; Mereghetti, E.

    2017-12-01

    We analyze neutrinoless double beta decay (0 νββ) within the framework of the Standard Model Effective Field Theory. Apart from the dimension-five Weinberg operator, the first contributions appear at dimension seven. We classify the operators and evolve them to the electroweak scale, where we match them to effective dimension-six, -seven, and -nine operators. In the next step, after renormalization group evolution to the QCD scale, we construct the chiral Lagrangian arising from these operators. We develop a power-counting scheme and derive the two-nucleon 0 νββ currents up to leading order in the power counting for each lepton-number-violating operator. We argue that the leading-order contribution to the decay rate depends on a relatively small number of nuclear matrix elements. We test our power counting by comparing nuclear matrix elements obtained by various methods and by different groups. We find that the power counting works well for nuclear matrix elements calculated from a specific method, while, as in the case of light Majorana neutrino exchange, the overall magnitude of the matrix elements can differ by factors of two to three between methods. We calculate the constraints that can be set on dimension-seven lepton-number-violating operators from 0 νββ experiments and study the interplay between dimension-five and -seven operators, discussing how dimension-seven contributions affect the interpretation of 0 νββ in terms of the effective Majorana mass m ββ .

  7. Liver-protecting effects of table beet (Beta vulgaris var. rubra) during ischemia-reperfusion.

    Science.gov (United States)

    Váli, László; Stefanovits-Bányai, Eva; Szentmihályi, Klára; Fébel, Hedvig; Sárdi, Eva; Lugasi, Andrea; Kocsis, Ibolya; Blázovics, Anna

    2007-02-01

    Table beet (Beta vulgaris var. rubra) contains important bioactive agents (betaine and polyphenols), which have a wide range of physiologic effects. Because nutritive antioxidants may reduce the occurrence of complications and postoperative mortality, dietary intake of polyphenols and vitamins before surgery may greatly contribute to the survival of patients. Our aim was to determine the liver-protecting properties of bioactive substances of table beet in a model of ischemia-reperfusion injury of the rat. Wistar rats were divided into two groups: non-treated (n = 24) and fed with table beet (n = 8). For 10 days the second group was treated with lyophilized table beet (2 g/kg body weight daily) mixed into the rat chow. Hepatic ischemia was maintained for 45 min, followed by 15 min of reperfusion. Ischemia-reperfusion was carried out on animals from both groups. Chemiluminescent intensity, H-donating ability, reducing power, free SH group concentration, Randox-total antioxidant status, glutathione peroxidase, and superoxide dismutase activities were determined by luminometry and spectrophotometry. Fatty acid (Shimadzu GC) and metal ion (inductively coupled plasma optical emission spectrometry) concentrations were observed in the liver. As a result of feeding, global parameters (H-donating ability, reducing power, free SH group concentration) and enzymatic antioxidants (glutathione peroxidase and superoxide dismutase) of the liver were found to increase significantly, which indicated that the treatment had a positive effect on its redox state. The increase found in zinc and copper content may protect the hepatocytes against oxidative stress because these elements are required for the function of superoxide dismutase enzymes. In the table beet group the concentration of short-chain fatty acids decreased, whereas that of long-chain fatty acids increased. The changes in metal element and fatty acid concentrations confirmed that these elements have an essential function

  8. The effect of transforming growth factor beta on human neuroendocrine tumor BON cell proliferation and differentiation is mediated through somatostatin signaling.

    Science.gov (United States)

    Leu, Frank P; Nandi, Minesh; Niu, Congrong

    2008-06-01

    The dual effect of the ubiquitous inflammatory cytokine transforming growth factor beta1 (TGF beta) on cellular proliferation and tumor metastasis is intriguing but complex. In epithelial cell- and neural cell-derived tumors, TGF beta serves as a growth inhibitor at the beginning of tumor development but later becomes a growth accelerator for transformed tumors. The somatostatin (SST) signaling pathway is a well-established antiproliferation signal, and in this report, we explore the interplay between the SST and TGF beta signaling pathways in the human neuroendocrine tumor cell line BON. We defined the SST signaling pathway as a determinant for neuroendocrine tumor BON cells in responding to TGF beta as a growth inhibitor. We also determined that TGF beta induces the production of SST and potentially activates the negative growth autocrine loop of SST, which leads to the downstream induction of multiple growth inhibitory effectors: protein tyrosine phosphatases (i.e., SHPTP1 and SHPTP2), p21(Waf1/Cip1), and p27(Kip1). Concurrently, TGF beta down-regulates the growth accelerator c-Myc protein and, collectively, they establish a firm antiproliferation effect on BON cells. Additionally, any disruption in the activation of either the TGF beta or SST signaling pathway in BON leads to "reversible" neuroendocrine-mesenchymal transition, which is characterized by the loss of neuroendocrine markers (i.e., chromogranin A and PGP 9.5), as well as the altered expression of mesenchymal proteins (i.e., elevated vimentin and Twist and decreased E-cadherin), which has previously been associated with elevated metastatic potential. In summary, TGF beta-dependent growth inhibition and differentiation is mediated by the SST signaling pathway. Therefore, any disruption of this TGF beta-SST connection allows BON cells to respond to TGF beta as a growth accelerator instead of a growth suppressor. This model can potentially apply to other cell types that exhibit a similar interaction of

  9. [Inhibitory effect of kappa/beta-carrageenan from red alga Tichocarpus crinitus on the development of a potato virus X infection in leaves of Datura stramonium L].

    Science.gov (United States)

    Nagorskaia, V P; Reunov, A V; Lapshina, L A; Ermak, I M; Barabanova, A O

    2010-01-01

    The effect of kappa/beta-carrageenan from red alda Tichocarpus crinitus on the development of a potato virus X (PVX) infection in the leaves of Datura stramonium L. has been studied. The treatment of leaves with carrageenan stimulates a protein synthesis in the cells, causing an increase in the size of nucleoli and in the number of mitochondria and membranes of the granular endoplasmic reticulum. At the same time, such treatment slightly stimulates lytic processes, causing an increase in the number of agranular endoplasmic reticulum cisterns, dictyosomes, and cytoplasmic vacuoles and the formation of cytoplasmic zones, transparent to electron microscopy. The carrageenan-induced stimulation of lytic processes results in the destruction of viral particles and can be considered as one of the defense mechanisms, preventing the intracellular accumulation of viruses. The carrageenan-stimulated formation of PVX-specific laminar structures, able to bind viral particles and, therefore, prevent their intracellular translocation and reproduction, represents another carrageenan-induced mechanism of the antiviral defense in plant cells.

  10. BHR equations re-derived with immiscible particle effects

    Energy Technology Data Exchange (ETDEWEB)

    Schwarzkopf, John Dennis [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Horwitz, Jeremy A. [Stanford Univ., CA (United States)

    2015-05-01

    Compressible and variable density turbulent flows with dispersed phase effects are found in many applications ranging from combustion to cloud formation. These types of flows are among the most challenging to simulate. While the exact equations governing a system of particles and fluid are known, computational resources limit the scale and detail that can be simulated in this type of problem. Therefore, a common method is to simulate averaged versions of the flow equations, which still capture salient physics and is relatively less computationally expensive. Besnard developed such a model for variable density miscible turbulence, where ensemble-averaging was applied to the flow equations to yield a set of filtered equations. Besnard further derived transport equations for the Reynolds stresses, the turbulent mass flux, and the density-specific volume covariance, to help close the filtered momentum and continuity equations. We re-derive the exact BHR closure equations which include integral terms owing to immiscible effects. Physical interpretations of the additional terms are proposed along with simple models. The goal of this work is to extend the BHR model to allow for the simulation of turbulent flows where an immiscible dispersed phase is non-trivially coupled with the carrier phase.

  11. Effects of heavy particle irradiation on central nervous system

    International Nuclear Information System (INIS)

    Nojima, Kumie; Liu Cuihua; Nagaoka, Shunji

    2003-01-01

    Effects of low dose heavy particle radiation to central nervous system were studied using mouse neonatal brain cells in culture exposed to heavy ions and X ray at fifth days of the culture. The subsequent biological effects were evaluated by an induction of apoptosis and the survivability of neurons focusing on the dependencies of the animal strains with different genetic types, and linear energy transfer (LET) of the different nucleons. Of the three mouse strains tested, severe combined immunodeficiency (SCID), B6 and C3H, used for brain cell culture, SCID was the most sensitive and C3H the least sensitive to both X-ray and carbon ion (290 MeV/n) when compared by 10% apoptotic induction. The LET dependency was compared with using SCID cells exposing to different ions, (X, C, Si, Ar, and Fe). Although no detectable LET dependency was observed at higher dose than 1 Gy, an enhancement was observed in the high LET region and at lower dose than 0.5 Gy. The survivability profiles of the neurons were different in the mouse strains and ions. Memory and learning function of adult mice were studied using water maze test after localized carbon- or iron-ion irradiation to hippocampus area. (author)

  12. Effects of heavy particle irradiation on central nervous system

    International Nuclear Information System (INIS)

    Nojima, Kumie; Nakadai, Taeko; Khono, Yukio; Nagaoka, Shunji

    2004-01-01

    Effects of low dose heavy particle radiation to central nervous system were studied using mouse neonatal brain cells in culture exposed to heavy ions and X ray at fifth days of the culture. The subsequent biological effects were evaluated by an induction of apoptosis and the survivability of neurons focusing on the dependencies of the animal strains with different genetic types, and linear energy transfer (LET) of the different nucleons. Of the three mouse strains tested, SCID, B6, B6C3F1 and C3H, used for brain cell culture, SCID was the most sensitive. Radiation sensitivity of these cells ware SCID>B6>B6C3F1>C3H to both X-ray and carbon ion (290 MeV/n) when compared by 10% apoptotic induction. The LET dependency was compared with using SCID cells exposing to different ions, (X, C, Si, Ar, and Fe). Although no detectable LET dependency was observed at higher dose than 1 Gy, an enhancement was observed in the high LET region and at lower dose than 0.5 Gy. The survivability profiles of the neurons were different in the mouse strains and ions. Memory and learning function of adult mice were studied using water maze test after localized carbon- or iron-ion irradiation to hippocampus area. Memory function were rapidly decrease after irradiation both ions. C-ion group were recovered 20 weeks after irradiation, but Iron group were different. (author)

  13. Effect of duct orientation on particle deposition in the human ...

    African Journals Online (AJOL)

    The simulations of macron size particles (1-5 μm) show that the existence of alveolar re-circulation and gravity orientation are key factors in determining the deposition in the last four generations of the human respiratory tract. Keywords: duct orientation, particle deposition, respiratory tract, discretization approach

  14. Effects of particle size and moisture content on the apparent ...

    African Journals Online (AJOL)

    It was further observed that the flours with smaller particle size produced pastes which were more viscous with more suspended and less sedimented or less aggregated particles; and hence are more likely suitable for the processing of most quality traditional foods like Kunu, Tuwo (Hausa); nri-oka, akamu (Ibo); eko, kokoro ...

  15. Effects of solar radiation on the orbits of small particles

    Science.gov (United States)

    Lyttleton, R. A.

    1976-01-01

    A modification of the Robertson (1937) equations of particle motion in the presence of solar radiation is developed which allows for partial reflection of sunlight as a result of rapid and varying particle rotations caused by interaction with the solar wind. The coefficients and forces in earlier forms of the equations are compared with those in the present equations, and secular rates of change of particle orbital elements are determined. Orbital dimensions are calculated in terms of time, probable sizes and densities of meteoric and cometary particles are estimated, and times of infall to the sun are computed for a particle moving in an almost circular orbit and a particle moving in an elliptical orbit of high eccentricity. Changes in orbital elements are also determined for particles from a long-period sun-grazing comet. The results show that the time of infall to the sun from a highly eccentric orbit is substantially shorter than from a circular orbit with a radius equal to the mean distance in the eccentric orbit. The possibility is considered that the free orbital kinetic energy of particles drawn into the sun may be the energy source for the solar corona.

  16. Health effects assessment of exposure to particles from wood smoke

    DEFF Research Database (Denmark)

    Nielsen, Elsa; Dybdahl, Marianne; Larsen, Poul Bo

    551,000 wood stoves and 48,000 wood boilers and the particle emission from these sources make up the most dominant source of particle emission in DK. It is estimated that this emission contributes to an annual increased PM2.5 level of 0.6 microgram/m³. From the dose-response relationships used...

  17. Effect of prolonged exposure to sublethal concentrations of DDT and DDE on protein expression in human pancreatic beta cells.

    Science.gov (United States)

    Pavlikova, Nela; Smetana, Pavel; Halada, Petr; Kovar, Jan

    2015-10-01

    Pollution of the environment represents one of less explored potential reasons for the worldwide epidemic of type 2 diabetes. One of the most prevalent organochlorine pollutants remains the pesticide DDT and its degradation product DDE. Despite some epidemiologic correlations between levels of DDT and DDE in human organism and the prevalence of diabetes, there is almost no information about the exact targets of these compounds inside pancreatic beta cells. To detect functional areas of pancreatic beta cells that could be affected by exposure to DDT and DDE, we analyzed changes in protein expression in the NES2Y human pancreatic beta cell line exposed to three sublethal concentrations (0.1 μM, 1 μM, 10 μM) of DDT and DDE for 1 month. Protein separation and identification was achieved using high-resolution 2D-electrophoresis, computer analysis and mass spectrometry. With these techniques, four proteins were found downregulated after exposure to 10 μM DDT: three cytoskeletal proteins (cytokeratin 8, cytokeratin 18 and actin) and one protein involved in glycolysis (alpha-enolase). Two proteins were downregulated after exposure to 10 μM DDE: cytokeratin 18 and heterogenous nuclear ribonucleoprotein H1 (HNRH1). These changes correlate with previously described effects of other stress conditions (e.g. exposure to palmitate, hyperglycemia, imidazoline derivative, and cytokines) on protein expression in pancreatic beta cells. We conclude that cytoskeletal proteins and their processing, glucose metabolism, and mRNA processing may represent targets affected by exposure to conditions hostile to pancreatic beta cells, including exposure to DDT and DDE. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Beneficial effects of beta-blockers on left ventricular function and cellular energy reserve in patients with heart failure.

    Science.gov (United States)

    Spoladore, Roberto; Fragasso, Gabriele; Perseghin, Gianluca; De Cobelli, Francesco; Esposito, Antonio; Maranta, Francesco; Calori, Giliola; Locatelli, Massimo; Lattuada, Guido; Scifo, Paola; Del Maschio, Alessandro; Margonato, Alberto

    2013-08-01

    Beta-blockers have been shown to improve left ventricular (LV) function in patients with heart failure. The aim of this study is to non-invasively assess, by means of in vivo 31P-magnetic resonance spectroscopy (31P-MRS), the effects of beta-blockers on LV cardiac phosphocreatine and adenosine triphosphate (PCr/ATP) ratio in patients with heart failure. Ten heart failure patients on full medical therapy were beta-blocked by either carvedilol or bisoprolol. Before and after 3 months of treatment, exercise testing, 2D echocardiography, MRS, New York Heart Association (NYHA) class, ejection fraction (EF), maximal rate-pressure product and exercise metabolic equivalent system (METS) were evaluated. Relative concentrations of PCr and ATP were determined by cardiac 31P-MRS. After beta-blockade, NYHA class decreased (from 2.2 ± 0.54 to 1.9 ± 0.52, P = 0.05), whereas EF (from 33 ± 7 to 44 ± 6%, P = 0.0009) and METS (from 6.74 ± 2.12 to 8.03 ± 2.39, P = 0.01) increased. Accordingly, the mean cardiac PCr/ATP ratio increased by 33% (from 1.48 ± 0.22 to 1.81 ± 0.48, P = 0.03). Beta-blockade-induced symptomatic and functional improvement in patients with heart failure is associated to increased PCr/ATP ratio, indicating preservation of myocardial high-energy phosphate levels. © 2012 The Authors Fundamental and Clinical Pharmacology © 2012 Société Française de Pharmacologie et de Thérapeutique. Published by John Wiley & Sons Ltd.

  19. Cytotoxicity effects induced by Zearalenone metabolites, alpha Zearalenol and beta Zearalenol, on cultured Vero cells.

    Science.gov (United States)

    Othmen, Zouhour Ouanes-Ben; Golli, Emna El; Abid-Essefi, Salwa; Bacha, Hassen

    2008-10-30

    Zearalenone (Zen) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium. It has been implicated in several mycotoxicosis in farm animals and in humans. The major metabolites of this mycotoxin in various species are alpha and beta Zearalenol. In vivo, Zen is mainly reduced to these alcoholic metabolites which cause reproductive tract disorders and impaired fertility due to their estrogenic activities. In this study, we examined the cytotoxicity of alpha and beta Zearalenol in cultured cells. For this purpose, the MTT assay was carried out and the influence of alpha and beta Zearalenol on protein and DNA syntheses was assessed. To evaluate the cell stress caused by these two metabolites, oxidative stress measured by MDA induction and stress protein induction (Hsp 70, Hsp 27) were tested. Results showed that alpha and beta Zearalenol were metabolites that caused cytotoxicity by inhibiting cell viability, protein and DNA syntheses and inducing oxidative damage and over-expression of stress proteins. However, the Zen metabolites exhibited lower toxicity than Zen, with beta zearalenol being the more active of the two metabolites.

  20. Drift of suspended ferromagnetic particles due to the Magnus effect

    Science.gov (United States)

    Denisov, S. I.; Pedchenko, B. O.

    2017-01-01

    A minimal system of equations is introduced and applied to study the drift motion of ferromagnetic particles suspended in a viscous fluid and subjected to a time-periodic driving force and a nonuniformly rotating magnetic field. It is demonstrated that the synchronized translational and rotational oscillations of these particles are accompanied by their drift in a preferred direction, which occurs under the action of the Magnus force. We calculate both analytically and numerically the drift velocity of particles characterized by single-domain cores and nonmagnetic shells and show that there are two types of drift, unidirectional and bidirectional, which can be realized in suspensions composed of particles with different core-shell ratios. The possibility of using the phenomenon of bidirectional drift for the separation of core-shell particles in suspensions is also discussed.

  1. Effective modification of particle surface properties using ultrasonic water mist

    DEFF Research Database (Denmark)

    Genina, Natalja; Räikkönen, Heikki; Heinämäki, Jyrki

    2009-01-01

    The goal of the present study was to design a new technique to modify particle surface properties and, through that, to improve flowability of poorly flowing drug thiamine hydrochloride and pharmaceutical sugar lactose monohydrate of two different grades. The powdered particles were supplied...... properties. It was found that rapid exposition of pharmaceutical materials by water mist resulted in the improvement of powder technical properties. The evident changes in flowability of coarser lactose were obviously due to smoothing of particle surface and decreasing in the level of fines with very slight...... increment in particle size. The changes in thiamine powder flow were mainly due to narrowing in particle size distribution where the tendency for better flow of finer lactose was related to surface and size modifications. The aqueous mist application did not cause any alteration of the crystal structures...

  2. Effects of cigarette smoke exposure on nicotinic acetylcholine receptor subunits {alpha}7 and {beta}2 in the sudden infant death syndrome (SIDS) brainstem

    Energy Technology Data Exchange (ETDEWEB)

    Machaalani, Rita, E-mail: rita.machaalani@sydney.edu.au [Department of Medicine, The University of Sydney, NSW 2006 (Australia); Bosch Institute, The University of Sydney, NSW 2006 (Australia); The Children' s Hospital at Westmead, NSW 2145 (Australia); Say, Meichien [Department of Medicine, The University of Sydney, NSW 2006 (Australia); Bosch Institute, The University of Sydney, NSW 2006 (Australia); Waters, Karen A. [Department of Medicine, The University of Sydney, NSW 2006 (Australia); Bosch Institute, The University of Sydney, NSW 2006 (Australia); The Children' s Hospital at Westmead, NSW 2145 (Australia)

    2011-12-15

    It is postulated that nicotine, as the main neurotoxic constituent of cigarette smoke, influences SIDS risk through effects on nicotinic acetylcholine receptors (nAChRs) in brainstem nuclei that control respiration and arousal. This study compared {alpha}7 and {beta}2 nAChR subunit expression in eight nuclei of the caudal and rostral medulla and seven nuclei of the pons between SIDS (n = 46) and non-SIDS infants (n = 14). Evaluation for associations with known SIDS risk factors included comparison according to whether infants had a history of exposure to cigarette smoke in the home, and stratification for sleep position and gender. Compared to non-SIDS infants, SIDS infants had significantly decreased {alpha}7 in the caudal nucleus of the solitary tract (cNTS), gracile and cuneate nuclei, with decreased