WorldWideScience

Sample records for coplanar congener kanechlor

  1. Effects of in ovo exposure to PCBs (coplanar congener, kanechlor mixture, hydroxylated metabolite) on the developing cell-mediated immunity in chickens

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, J.; Matsuda, M.; Kawano, M.; Wakimoto, T. [Faculty of Agriculture, Ehime Univ., Matsuyama, Ehime (Japan); Kashima, Y. [Dept. of Hygiene, Yokohama City Univ. School of Medicine, Yokohama (Japan)

    2004-09-15

    Polychlorinated biphenyls (PCBs) are wide spread environmental contaminants and known to cause various adverse effects on health of human and wildlife. Immune system is one of the several targets for toxic effects of PCBs and its normal balance is often disrupted by the exposure of the compounds. For example, PCBs may induce immune suppression and result in increased susceptibility to bacterial and viral infections, or conversely, excessive immune enhancement may cause adverse outcomes including as autoimmune disease and anergy. Therefore immune function is regarded as one of an important endpoint in toxicological risk assessment. There are a number of studies shown that neonatal organisms perinatally exposed to polyhalogenated aromatic hydrocarbons (PHAHs) such as PCBs have severer effects on their immune system than adult. Dioxins and coplanar PCB congeners, structurally planar PHAHs are known to have high affinity for aryl hydrocarbon receptor (AhR). 2,3,7,8-tetrachlorinated dibenzo-p-dioxin (TCDD) have the strongest affinity among such compounds and these are considered to act on immune system through AhR. On the other hand, such as non-planar PCB congeners with low affinity for AhR, which are abundantly contained in commercial PCB preparations have non-additive (antagonistic) effects on immune function. Prenatal exposure of TCDD to rodent induced abnormal lymphoid development in the thymus and thymus-dependent immune functions were remarkably disturbed. Although several experimental studies in mammals have been carried out on the developmental immunotoxicity of PCBs, there are still limited information available on avian species. Thus in this study, prenatal exposure to low level of PCBs and the effects on the developing immune system were investigated with chicken as a model animal of avian species, especially it is focused on the cell-mediated immune function.

  2. Coplanar PCB congeners increase uterine weight and frontal cortical dopamine in the developing rat: implications for developmental neurotoxicity.

    Science.gov (United States)

    Seegal, Richard F; Brosch, Karl O; Okoniewski, Richard J

    2005-07-01

    We show that developmental exposure of the laboratory rat to the coplanar polychlorinated biphenyl (PCB) congener 3,4,3',4'-tetrachlorobiphenyl (TCB) and the structurally similar congener 3,4,5,3',4'-pentachlorobiphenyl (PtCB) elevates dopamine (DA) concentrations in the prefrontal cortex (PFC). To determine whether these coplanar congeners are estrogenic, and may thus contribute to the elevations in PFC DA, we measured uterine wet weight (UWW) in prepubertal rats exposed to TCB or PtCB. For comparison, additional animals were exposed to either the ortho-substituted congener 2,4,2',4'-tetrachlorobiphenyl (o-TCB) or 3,4,5,3',4',5'-hexachlorobiphenyl (HCB), a coplanar congener highly resistant to metabolism. Both TCB and PtCB increased UWW, but this effect was blocked after exposure to the anti-estrogen ICI 182,780. Neither o-TCB nor HCB altered UWW. These results demonstrate that certain coplanar PCB congeners and/or their metabolites, are estrogenic, and suggest that exposure during critical periods of neuronal development may increase central DA concentrations, and by inference, alter behavior.

  3. Congener-specific bioaccumulation of PCBs in different water bird species

    OpenAIRE

    Zimmermann, Gaby; Dietrich, Daniel R.; Schmid, Peter; Schlatter, Christian

    1997-01-01

    The bioaccumulation behaviour of single PCB congeners in three trophic levels of a food chain in an aquatic ecosystem was studied. Congener-specific biotransfer factors were calculated comparing PCB concentrations in tissues of 4 water bird species with the contents measured in their food source. The coplanar PCBs were of particular interest.The maximum concentrations of individual PCB congeners detected in mussels, fish and birds were 0.5, 4, and 26 μg/g extractable lipids, respectively. In ...

  4. Compact superconducting coplanar microwave beam splitters

    Energy Technology Data Exchange (ETDEWEB)

    Baust, Alexander; Haeberlein, Max; Goetz, Jan; Hoffmann, Elisabeth; Menzel, Edwin P.; Schwarz, Manuel J.; Wulschner, Friedrich; Zhong, Ling; Deppe, Frank; Marx, Achim; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TUM, Garching (Germany); Kalb, Norbert; Losinger, Thomas [Physik-Department, TUM, Garching (Germany)

    2012-07-01

    The recent evolution of circuit quantum electrodynamics systems making use of standing-wave microwave modes towards setups for propagating quantum microwaves has triggered the need for low-loss superconducting microwave beam splitters. Such a device should have ports compatible with the coplanar geometry relevant for circuit QED and, at the same time, be compact allowing for scalability. This combination presents fundamental and technological challenges. In this work, we present the fabrication and characterization of various compact superconducting coplanar microwave beam splitters. In addition, we discuss efforts towards a tunable beam splitter.

  5. Coplanar waveguide feed for microstrip patch antennas

    Science.gov (United States)

    Smith, R. L.; Williams, J. T.

    1992-01-01

    A coplanar waveguide (CPW) loop is shown to be an effective low VSWR feed for microstrip antennas. The low VSWR transition between the CPW and the antenna is obtained without the use of a matching circuit, and it is relatively insensitive to the position of the antenna and the feed.

  6. Uptake of polychlorodibenzo-p-dioxins, polychlorodibenzofurans and coplanar polychlorobiphenyls in chickens.

    Science.gov (United States)

    Pirard, Catherine; De Pauw, Edwin

    2005-05-01

    Twelve chickens raised according to commercial standards were fed a diet containing about 30 ng total toxic equivalent (TEQ)/kg for 10 weeks. Persistent pollutants were introduced into the poultry feed via recycled oil to mimic contamination conditions closely resembling those occurring during the Belgian crisis five years ago. Absorption of congeners with the same chlorination degree did not seem to depend on the substitution, demonstrating that unlike for cows, no preferential absorption for 2,3,7,8-substituted compounds could be remarked for chickens. As already observed, absorption decreased with increasing number of chlorines and was not linearly dependent on the octanol/water partition coefficient. On the other hand, no real differences were observed in the absorption of coplanar polychlorinated biphenyls (c-PCBs) with regard to degree of chlorination. When monitored during the course of experiment, concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and c-PCBs in excreta reached an apparent steady state after 5 weeks. Only 2,3,7,8-substituted dioxins or furans were found in tissues and eggs. All organs showed the same congener profile and similar lipid-normalized concentration, except for the liver. Bioconcentration factors were evaluated, highlighting that the liver preferentially retained highly chlorinated congeners. No depletion of dioxin and PCB concentration was observed after 8 and 14 weeks of control diet, but high inter-individual variation occurs.

  7. Tunable coplanar waveguide resonator with nanowires

    Institute of Scientific and Technical Information of China (English)

    周渝; 郏涛; 翟计全; 汪橙; 钟先茜; 曹志敏; 孙国柱; 康琳; 吴培亨

    2015-01-01

    A tunable superconducting half-wavelength coplanar waveguide resonator (CPWR) with Nb parallel nanowires ∼300 nm in width embedded in the center conductor was designed, fabricated, and measured. The frequency shift and the amplitude attenuation of the resonance peak under irradiation of 404-nm pulse laser were observed with different light powers at 4.2 K. The RF power supplied to such a CPWR can serve as current bias, which will affect the light response of the resonator.

  8. Nanoscale constrictions in superconducting coplanar waveguide resonators

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Mark David; Naether, Uta; Ciria, Miguel; Zueco, David; Luis, Fernando, E-mail: fluis@unizar.es [Instituto de Ciencia de Materiales de Aragón, CSIC—Universidad de Zaragoza, 50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Sesé, Javier [Instituto de Nanociencia de Aragón, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza (Spain); Atkinson, James; Barco, Enrique del [Department of Physics, University of Central Florida, Orlando, Florida 32816 (United States); Sánchez-Azqueta, Carlos [Dpto. de Ingeniería Electrónica y Telecomunicaciones, Universidad de Zaragoza, 50009 Zaragoza (Spain); Majer, Johannes [Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna (Austria)

    2014-10-20

    We report on the design, fabrication, and characterization of superconducting coplanar waveguide resonators with nanoscopic constrictions. By reducing the size of the center line down to 50 nm, the radio frequency currents are concentrated and the magnetic field in its vicinity is increased. The device characteristics are only slightly modified by the constrictions, with changes in resonance frequency lower than 1% and internal quality factors of the same order of magnitude as the original ones. These devices could enable the achievement of higher couplings to small magnetic samples or even to single molecular spins and have applications in circuit quantum electrodynamics, quantum computing, and electron paramagnetic resonance.

  9. High-Tc superconductor coplanar waveguide filter

    Science.gov (United States)

    Chew, Wilbert; Bajuk, Louis J.; Cooley, Thomas W.; Foote, Marc C.; Hunt, Brian D.; Rascoe, Daniel L.; Riley, A. L.

    1991-01-01

    Coplanar waveguide (CPW) low-pass filters made of YBa2Cu3O(7-delta) (YBCO) on LaAlO3 substrates, with dimensions suited for integrated circuits, were fabricated and packaged. A complete filter gives a true idea of the advantages and difficulties in replacing thin-film metal with a high-temperature superconductor in a practical circuit. Measured insertion losses in liquid nitrogen were superior to the loss of a similar thin-film copper filter throughout the 0- to 9.5-GHz passband. These results demonstrate the performance of fully patterned YBCO in a practical CPW structure after sealing in a hermetic package.

  10. Dosimetric comparison between coplanar and non coplanar field radiotherapy for ethmoid sinus cancer

    Directory of Open Access Journals (Sweden)

    Serre Antoine

    2007-09-01

    Full Text Available Abstract Background To compare non coplanar field (NCF with coplanar field (CF -intensity-modulated radiotherapy (IMRT planning for ethmoid cancer. Methods Seven patients treated with NCF IMRT for ethmoid cancer were studied. A CF IMRT optimization was prepared with the same constraints as for the NCF treatment. The maximum point doses (D max obtained for the different optic pathway structures (OPS should differ no more than 3% from those achieved with the NCF IMRT plan. The distribution of the dose in the target volume and in the critical structures was compared between the two techniques, as well as the Conformity (CI and the Homogeneity Indexes (HI in the target volume. Results We noted no difference between the two techniques in the OPS for the D1, D2, and D5%, in the inner ear and controlateral lens for the average Dmax, in the temporo-mandibular joints for the average mean dose, in the cord and brainstem for the average D1%. The dose-volume histograms were slightly better with the NCF treatment plan for the planning target volume (PTV with a marginally better HI but no impact on CI. We found a great improvement in the PTV coverage with the CF treatment plan for two patients with T4 tumors. Conclusion IMRT is one of the treatment options for ethmoid cancer. The PTV coverage is optimal without compromising the protection of the OPS. The impact of non coplanar versus coplanar set up is very slight.

  11. MXene-on-Paper Coplanar Microsupercapacitors

    KAUST Repository

    Kurra, Narendra

    2016-09-05

    A simple and scalable direct laser machining process to fabricate MXene-on-paper coplanar microsupercapacitors is reported. Commercially available printing paper is employed as a platform in order to coat either hydrofluoric acid-etched or clay-like 2D Ti3C2 MXene sheets, followed by laser machining to fabricate thick-film MXene coplanar electrodes over a large area. The size, morphology, and conductivity of the 2D MXene sheets are found to strongly affect the electrochemical performance due to the efficiency of the ion-electron kinetics within the layered MXene sheets. The areal performance metrics of Ti3C2 MXene-on-paper microsupercapacitors show very competitive power-energy densities, comparable to the reported state-of-the-art paper-based microsupercapacitors. Various device architectures are fabricated using the MXene-on-paper electrodes and successfully demonstrated as a micropower source for light emitting diodes. The MXene-on-paper electrodes show promise for flexible on-paper energy storage devices. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. NEW RESULTS FROM TESTING OF COPLANAR-GRID CDZNTE DETECTOR.

    Energy Technology Data Exchange (ETDEWEB)

    CARINI, G.A.; ET AL.

    2005-07-31

    New results from studies of coplanar-grid CdZnTe (CZT) detectors are presented. The coplanar-grid detectors, were investigated by using a highly collimated X-ray beam available at Brookhaven's National Synchrotron Light Source and by applying a pulse-shape analysis. The coplanar-grid detector operates as a single-carrier device. Despite the fact that its operational principle is well known and has been investigated by many groups in the past, we found some new details that may explain the performance limits of these types of devices. The experimental results have been confirmed by extensive computer modeling.

  13. Optimal impulsive ellipse-to-circle coplanar rendezvous

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The problem of ellipse-to-circle coplanar rendezvous with chaser spacecraft in low eccentricity was investigated in this paper.With reference frame established in the centroid of the target spacecraft,the process of ellipse-to-circle coplanar rendezvous was described by the relative equations based on cy-lindrical reference frame,and then the solutions and distributions of optimal rendezvous models of a kind of close ellipse-to-circle coplanar rendezvous were provided.The simulation results showed that the guidance law based on the optimal rendezvous model in this research has good performance,and that the distributions of optimal rendezvous models of ellipse-to-circle coplanar rendezvous with the chaser spacecraft in low eccentricity are similar,albeit with slight difference,to those of rendezvous between close circular orbits.The work in this paper is a useful extension to Prussing’s optimal ren-dezvous theory between close circular orbits.

  14. Coplanar interdigitated grid detector with single electrode readout

    Science.gov (United States)

    Luke, Paul N.

    2001-01-01

    The coplanar interdigitated grid technique with single electrode readout provides substantial spectral performance improvement over that of conventional full-area planar electrode detectors and over coplanar interdigitated grid detectors which measure the difference between the induced charge signals from two interdigitated coplanar grid electrodes. The signal from only one interdigitated grid electrode is read out. The signal response is optimized by changing the relative areas of the two grid electrodes and the bias applied across the detector. Only one preamplifier is needed and signal subtraction is not necessary. This eliminates the electronic noise contribution from the additional preamplifier used in the normal coplanar grid implementation, and conventional single-amplifier detector electronics can be used.

  15. Ultrathin low-frequency sound absorbing panels based on coplanar spiral tubes or coplanar Helmholtz resonators

    Science.gov (United States)

    Cai, Xiaobing; Guo, Qiuquan; Hu, Gengkai; Yang, Jun

    2014-09-01

    Performance of classic sound absorbing materials strictly depends on their thickness, with a minimum of one-quarter wavelength to reach full sound absorption. In this paper, we report ultrathin sound absorbing panels that completely absorb sound energy with a thickness around one percent of wavelength. The strategy is to bend and coil up quarter-wavelength sound damping tubes into 2D coplanar ones, and embed them into a matrix to form sound absorbing panel. Samples have been designed and fabricated by 3D printing. Efficacies of sound absorption by these panels were validated through good agreement between theoretical analysis and experimental measurements.

  16. Ultra-Wideband Coplanar-Fed Monopoles: A Comparative Study

    Directory of Open Access Journals (Sweden)

    J. Jilkova

    2008-04-01

    Full Text Available The paper provides an experimental comparison of four types of ultra-wideband coplanar-fed planar monopole antennas. Parameters of the open stub completed by an L-shaped monopole and the cross monopole were adopted from the literature. The forked monopole and the coplanar monopole were fabricated and measured. Monopoles were compared from the viewpoint of the impedance bandwidth, gain, directivity patterns and dimensions.

  17. LHC data and cosmic ray coplanarity at superhigh energies

    CERN Document Server

    Mukhamedshin, Rauf

    2016-01-01

    A new phenomenological model FANSY 2.0 is designed, which makes it possible to simulate hadron interactions via traditional QGSM-type particle generation as well as coplanar generation of most energetic particles, observed in cosmic ray experiments. FANSY 2.0 reproduces a lot of LHC (ALICE, ATLAS, CMS, TOTEM, LHCf) data. Results of model simulations are compared with LHC data. Problems of coplanarity are considered and a testing experiment is proposed.

  18. Congener Production in Blood Samples During Preparation and Storage

    DEFF Research Database (Denmark)

    Felby, Søren; Nielsen, Erik

    1995-01-01

    Retsmedicin, congener production, preparation, head space GC, acetone, isobutanol, storage, blood samples, n-propanol, methanol, methylethylketone......Retsmedicin, congener production, preparation, head space GC, acetone, isobutanol, storage, blood samples, n-propanol, methanol, methylethylketone...

  19. Correlations of emission concentrations among PCDDs/PCDFs, co-planar PCBs and HCB from major thermal stationary sources

    Energy Technology Data Exchange (ETDEWEB)

    Kim, S.C.; Choe, S.H.; Na, J.G.; Hwang, S.R.; Lee, Z.H.; Chang, J.Y.; Cho, H.J. [National Institute of Environmental Research, Inchon (Korea)

    2004-09-15

    Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofuran (PCDFs), polychlorinated biphenyls (PCBs), and hexachlorobenzene (HCB) are known as unintentionally produced chemicals (UPCs) from a variety of manufacturing and thermal processes. The UPCs are contained in products as impurities or byproducts in the manufacturing processes of chlorinated pesticides and solvents, and in the bleaching process of pulp. In particular, thermal processes such as incinerator and melting or smelting furnaces produce theses chemicals as products of incomplete combustion (PICs), which are resulted from the insufficient 3Ts for complete combustion: temperature, time, and turbulence. These characteristics of UPCs, therefore, lead to difficulty not only in estimating the formation and emission concentrations but also in applying removal technologies for these chemicals. In addition, PCDDs/PCDFs and PCBs have many congeners of 210 and 209 types, respectively, and are emitted into the atmosphere at trace levels. Thus, the analysis of the emission concentration of UPCs requires a precise sampling and analytical procedure, which is time-consuming and high cost-consumable work. Some articles6,7, which discussed municipal solid waste (MSW) incinerators, have proposed the prediction of the emission level of PCDDs/PCDFs with simply measured indicators, such as operating parameters or other low-molecular-weight chemicals in flue gas. In the present study, major stationary emission sources of UPCs, such as MSW incinerators, sintering furnaces, and smelting furnaces in the ferrous and nonferrous metal industry were selected for an investigation of the emission levels of UPCs. HCB, which has single congener and can be more simply measured by gaschromatographic separation than PCDDs/PCDFs or co-planar PCBs, was used as an indicator to evaluate the correlation of emission concentrations among UPCs and to predict the emission level of PCDDs/PCDFs and co-planar PCBs.

  20. Line segment matching and reconstruction via exploiting coplanar cues

    Science.gov (United States)

    Li, Kai; Yao, Jian

    2017-03-01

    This paper introduces a new system for reconstructing 3D scenes from Line Segments (LS) on images. A new LS matching algorithm and a novel 3D LS reconstruction algorithm are incorporated into the system. Two coplanar cues that indicates image LSs are coplanar in physical (3D) space are extensively exploited in both algorithms: (1) adjacent image LSs are coplanar in space in a high possibility; (2) the projections of coplanar 3D LSs in two images are related by the same planar homography. Based on these two cues, we efficiently match LSs from two images firstly in pairs through matching the V-junctions formed by adjacent LSs, and secondly in individuals by exploiting local homographies. We extract for each V-junction a scale and affine invariant local region to match V-junctions from two images. The local homographies estimated from V-junction matches are used to match LSs in individuals. To get 3D LSs from the obtained LS matches, we propose to first estimate space planes from clustered LS matches and then back-project image LSs onto the space planes. Markov Random Field (MRF) is introduced to help more reliable LS match clustering. Experiments shows our LS matching algorithm significantly improves the efficiency of state-of-the-art methods while achieves comparable matching performance, and our 3D LS reconstruction algorithm generates more complete and detailed 3D scene models using much fewer images.

  1. Experimental Evaluation of a Coplanar Airborne Separation Display

    NARCIS (Netherlands)

    Ellerbroek, J.; Brantegem, K. C. R.; Van Paassen, M. M.; Mulder, M.

    2013-01-01

    Two experiments, an active conflict resolution task and a passive situation awareness assessment, were conducted that compared two versions of a constraint-based coplanar airborne separation assistance display. A baseline display showed a maneuver space based on 2-D projections of traffic and perfor

  2. Thin foil silicon solar cells with coplanar back contacts

    Science.gov (United States)

    Ho, F.; Iles, P. A.; Baraona, C. R.

    1981-01-01

    To fabricate 50 microns thick, coplanar back contact (CBC) silicon solar cells, wraparound junction design was selected and proved to be effective. The process sequence used, the cell design, and the cell performance are described. CBC cells with low solar absorptance have shown AMO efficiencies to 13%, high cells up to 14%; further improvements are projected with predictable optimization.

  3. Comportamiento de Laminaciones Coplanares y No Coplanares en Acero API5L X52 Simuladas mediante Elementos Finitos Behavior of Coplanar and Non-Coplanar Laminations in API5L X52 Steel Simulated by Finite Elements

    Directory of Open Access Journals (Sweden)

    Alberto Servin

    2009-01-01

    Full Text Available Se determina el comportamiento mecánico de laminaciones simples y escalonadas modeladas por elementos finitos en condiciones no lineales de esfuerzo-deformación, para comprender la secuencia de la interacción de los campos de esfuerzos en los extremos de la grietas. Se estableció una matriz de simulación variando la extensión circunferencial de las laminaciones, con espesor del tubo de 610mm de diámetro, con separación vertical y horizontal para el caso de laminaciones escalonadas. Se determino la función de distribución de esfuerzos en la región de las laminaciones en función de la presión en la grieta y en el tubo. Se estableció la presión que origina alcanzar la cedencia y resistencia ultima del material API5L X52, determinando que las laminaciones simples cuya extensión circunferencial va de 24 a 127 mm, soportan 50% más de presión de cedencia que las laminaciones escalonadas, y el 100% más de presión máxima permisible. Basados en la graficas presión versus radio de las laminaciones se concluye que las laminaciones no coplanares representan mayor riesgo de agrietamiento en una tubería.The mechanical behavior of the coplanar and non coplanar laminations by finite element using non lineal material conditions was determined, with the purpose of knowing the interaction sequence of the stress fields in the crack tips. The analysis includes a matrix simulation considering the circumferential length lamination, wall thickness of the pipe 610mm diameter, with vertical and horizontal distance for non coplanar laminations. The stress distribution in the laminations regions as a function of the internal pressures in the cracks and pipe were determined. The simulations done allowed defining the yield and the strength pressure that reach the mechanical properties of the API 5L X52. It was found that coplanar laminations with 24 at 127mm of circumferential length resist 50% more yield pressure than the non coplanar laminations and

  4. Asymmetrical coupled coplanar-type transmission lines with anisotropic substrates

    Science.gov (United States)

    Kitazawa, T.; Hayashi, Y.; Mittra, R.

    1986-07-01

    Various types of transmission lines with anisotropic substances were investigated for use in microwave and millimeter wave integrated circuits. These include single and coupled striplines, slot lines, and coplanar-type transmission lines. The coplanar-type transmission lines (CTLs) are promising because of their easy adaptation to shunt element connections. The application of coupled coplanar-type transmission lines (C-CTLs) were studied based on the quasistatic and hybrid mode formulations and accurate numerical values are available for the cases with isotropic and/or anisotropic substrates. However, most of them assume structural symmetry. The theoretical approach for the asymmetrical version is available only for the propagation constant of the case with a single isotropic substrate. The analytical method for the general structure of asymmetrical C-CTLs with an anisotropic substrate. This method includes both the hybrid mode and the quasistatic formulations and is useful for accurately computing the characteristics impedances as well as propagation constants of various types of assymetrical C-CTLs.

  5. Exposure to coplanar PCBs induces endothelial cell inflammation through epigenetic regulation of NF-κB subunit p65

    Science.gov (United States)

    Liu, Dandan; Perkins, Jordan T.; Petriello, Michael C.; Hennig, Bernhard

    2015-01-01

    Epigenetic modifications of DNA and histones alter cellular phenotypes without changing genetic codes. Alterations of epigenetic marks can be induced by exposure to environmental pollutants and may contribute to associated disease risks. Here we test the hypothesis that endothelial cell dysfunction induced by exposure to polychlorinated biphenyls (PCBs) is mediated in part though histone modifications. In this study, human vascular endothelial cells were exposed to physiologically relevant concentrations of several PCBs congeners (e.g., PCBs 77, 118, 126 and 153) followed by quantification of inflammatory gene expression and changes of histone methylation. Only exposure to coplanar PCBs 77 and 126 induced the expression of histone H3K9 trimethyl demethylase jumonji domain-containing protein 2B (JMJD2B) and nuclear factor-kappa B (NF-κB) subunit p65, activated NF-κB signaling as evidenced by nuclear translocation of p65, and up-regulated p65 target inflammatory genes, such as interleukin (IL)-6, C-reactive protein (CRP), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and IL-1α/β. The increased accumulation of JMJD2B in the p65 promoter led to a depletion of H3K9me3 repression mark, which accounts for the observed up-regulation of p65 and associated inflammatory genes. JMJD2B gene knockdown confirmed a critical role for this histone demethylase in mediating PCB-induced inflammation of the vascular endothelium. Finally, it was determined, via chemical inhibition, that PCB-induced up-regulation of JMJD2B was estrogen receptor-alpha (ER-α) dependent. These data suggest that coplanar PCBs may exert endothelial cell toxicity through changes in histone modifications. PMID:26519613

  6. Congener-specific metabolism and sequestration of dioxin-like compounds by cytochrome P450 1A induced in the liver of crows from Tokyo, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, M.; Iwata, H.; Tanabe, S. [Ehime Univ., Matsuyama (Japan); Yoneda, K.; Hashimoto, T. [Japan Wildlife Research Center, Tokyo (Japan)

    2004-09-15

    Jungle crow (JC; Corvus macrorhynchos) is a useful bioindicator for monitoring contaminants in urban areas, because this species is residential, occupies a same habitat as human, and feeds variety of foods including domestic waste and garbage. Therefore, JCs may accumulate environmental contaminants such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs), which are released by human activities. Induction of cytochrome P450 (CYP) 1A is a responsive mechanism elicited by exposure to dioxinlike compounds including PCDDs/DFs and Co-PCBs. Toxicokinetic behavior of dioxin-like compounds in organisms is controlled by excretion, metabolism and absorption. These processes are, at least partly, dependent on CYP1A expression in addition to chemical structure and number of chlorine substitution of each congener. Low chlorinated congeners such as 2378-T{sub 4}CDD, 2378- T{sub 4}CDF, 12378-P{sub 5}CDD and 33'44'-PCB were easily metabolized by CYP1A1/2 in rat liver microsomes. PCDDs/DFs accumulate in hepatic tissue to a greater extent than adipose tissue in rats and mice. Recent study using transgenic CYP1A2 knockout mice demonstrated that CYP1A2 is responsible for the sequestration of 2378-T{sub 4}CDD and 23478-P{sub 5}CDF in hepatic tissue. Therefore, CYP1A is considered as a key factor responsible for toxicokinetics of dioxin-like compounds. However, there's no comprehensive data on the contribution of CYP1A to the toxicokinetics of dioxin-like congeners in wild populations. In this study, we investigated contamination levels of PCDDs/DFs and Co-PCBs in liver and breast muscle of JCs from Tokyo, Japan, and interactions of dioxin-like congeners with hepatic CYP to elucidate congener-specific toxicokinetics related to CYP expression in JC.

  7. Geometry of magnetosonic shocks and plane-polarized waves: Coplanarity Variance Analysis (CVA)

    Science.gov (United States)

    Scudder, J. D.

    2005-02-01

    Minimum Variance Analysis (MVA) is frequently used for the geometrical organization of a time series of vectors. The Coplanarity Variance Analysis (CVA) developed in this paper reproduces the layer geometry involving coplanar magnetosonic shocks or plane-polarized wave trains (including normals and coplanarity directions) 300 times more precisely (CVA technique exploits the eigenvalue degeneracy of the covariance matrix present at planar structures to find a consistent normal to the coplanarity plane of the fluctuations. Although Tangential Discontinuities (TDs) have a coplanarity plane, the eigenvalues of their covariance matrix are usually not degenerate; accordingly, CVA does not misdiagnose TDs as shocks or plane-polarized waves. Together CVA and MVA may be used to sort between the hypotheses that the time series is caused by a one-dimensional current layer that has magnetic disturbances that are (1) coplanar, linearly polarized (shocks/plane waves), (2) intrinsically helical (rotational/tangential discontinuities), or (3) neither 1 nor 2.

  8. Levels and congener profiles of PCBs and PCDD/Fs in blue shark (Prionace glauca) liver from the South-Eastern Mediterranean Sea (Italy).

    Science.gov (United States)

    Storelli, Maria Maddalena; Barone, Grazia; Storelli, Arianna; Marcotrigiano, Giuseppe Onofrio

    2011-01-01

    Liver of blue shark (Prionace glauca) specimens from the South-Eastern Mediterranean Sea were analyzed for the presence of polychlorinated biphenyls (PCBs), including coplanar congeners, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). PCBs were the dominant chemicals, followed by PCDFs and PCDDs. The pattern of PCB congener concentrations in the hepatic tissue was dominated by higher chlorinated compounds. The specific profile of toxic PCDD/F congeners was characterized mainly by 2,3,7,8-TCDF and 2,3,7,8-TCDD, followed by 1,2,3,6,7,8-HxCDD and 2,3,4,6,7,8-HxCDF. The total 2,3,7,8-TCDD toxic equivalent (TEQs) was 149 pg g⁻¹ lipid wt. The profile of TEQ shows that PCDDs present the greatest risk to this species contributing to total toxicity with a percentage approximately of 60%, while the contribution of PCDFs and DL-PCBs is almost the same being 22.4% and 21.6%, respectively. Further investigations are urgently needed to characterize the PCDD/Fs contamination levels not only in elasmobranch fish but in all Mediterranean marine biota. Copyright © 2010 Elsevier Ltd. All rights reserved.

  9. Coplanar waveguide flux qubit suitable for quantum annealing

    Science.gov (United States)

    Quintana, Chris; Chen, Yu; Sank, D.; Kafri, D.; Megrant, A.; White, T. C.; Shabani, A.; Barends, R.; Campbell, B.; Chen, Z.; Chiaro, B.; Dunsworth, A.; Fowler, A.; Jeffrey, E.; Kelly, J.; Lucero, E.; Mutus, J. Y.; Neeley, M.; Neill, C.; O'Malley, P. J. J.; Roushan, P.; Vainsencher, A.; Wenner, J.; Martinis, J. M.

    We introduce the ''fluxmon'' flux qubit, designed with the goal of practical quantum annealing. The qubit's capacitance and linear inductance are provided by a coplanar waveguide on a low loss substrate, minimizing dielectric dissipation and in principle allowing for GHz-scale inter-qubit coupling in a highly connected tunable architecture. Utilizing a dispersive microwave readout scheme, we characterize single-qubit noise and dissipation, and present a simple tunable inter-qubit coupler. We discuss tradeoffs between coherence and coupling in a quantum annealing architecture. This work was supported by Google Inc. and by the NSF GRFP.

  10. Spatial trends of polybrominated diphenyl ether (PBDE) congeners

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spatial trends of polybrominated diphenyl ether (PBDE) congeners were analyzed in young of the year bluefish collected along the U.S. Atlantic coastline from...

  11. Integral dose investigation of non-coplanar treatment beam geometries in radiotherapy.

    Science.gov (United States)

    Nguyen, Dan; Dong, Peng; Long, Troy; Ruan, Dan; Low, Daniel A; Romeijn, Edwin; Sheng, Ke

    2014-01-01

    Automated planning and delivery of non-coplanar plans such as 4π radiotherapy involving a large number of fields have been developed to take advantage of the newly available automated couch and gantry on C-arm gantry linacs. However, there is an increasing concern regarding the potential changes in the integral dose that needs to be investigated. A digital torso phantom and 22 lung and liver stereotactic body radiation therapy (SBRT) patients were included in the study. The digital phantom was constructed as a water equivalent elliptical cylinder with a major axis length of 35.4 cm and minor axis of 23.6 cm. A 4.5 cm diameter target was positioned at varying depths along the major axis. Integral doses from intensity modulated, non-coplanar beams forming a conical pattern were compared against the equally spaced coplanar beam plans. Integral dose dependence on the phantom geometry and the beam number was also quantified. For the patient plans, the non-coplanar and coplanar beams and fluences were optimized using a column generation and pricing approach and compared against clinical VMAT plans using two full (lung) or partial coplanar arcs (liver) entering at the side proximal to the tumor. Both the average dose to the normal tissue volume and the total volumes receiving greater than 2 Gy (V2) and 5 Gy (V5) were evaluated and compared. The ratio of integral dose from the non-coplanar and coplanar plans depended on the tumor depth for the phantom; for tumors shallower than 10 cm, the non-coplanar integral doses were lower than coplanar integral doses for non-coplanar angles less than 60°. Similar patterns were observed in the patient plans. The smallest non-coplanar integral doses were observed for tumor 6-8 cm deep. For the phantom, the integral dose was independent of the number of beams, consistent with the liver SBRT patients but the lung SBRT patients showed slight increase in the integral dose when more beams were used. Larger tumor size and larger patient

  12. Assimilation efficiency of PBDE congeners in Chinook salmon.

    Science.gov (United States)

    Dietrich, Joseph P; Strickland, Stacy A; Hutchinson, Greg P; Van Gaest, Ahna L; Krupkin, Alex B; Ylitalo, Gina M; Arkoosh, Mary R

    2015-03-17

    Polybrominated diphenyl ether (PBDE) flame retardants are environmental contaminants that can accumulate in biota. PBDE accumulation in an organism depends on exposure, assimilation efficiency, and elimination/metabolism. Net assimilation efficiency represents the fraction of the contaminant that is retained in the organism after exposure. In the present study, congener-specific estimates of net PBDE assimilation efficiencies were calculated from dietary exposures of juvenile Chinook salmon. The fish were exposed to one to eight PBDE congeners up to 1500 ng total PBDEs/g food. Mean assimilation efficiencies varied from 0.32 to 0.50 for BDE congeners 28, 47, 99, 100, 153, and 154. The assimilation efficiency of BDE49 was significantly greater than 100%, suggesting biotransformation from higher brominated congeners. Whole body concentrations of BDE49 significantly increased with both exposure to increasing concentrations of BDE99 and decreasing fish lipid levels, implying lipid-influenced debromination of BDE99 to BDE49. Excluding BDE49, PBDE assimilation efficiency was not significantly related to the numbers of congeners in the diets, or congener hydrophobicity, but was greater in foods with higher lipid levels. Estimates of PBDE assimilation efficiency can be used in bioaccumulation models to assess threats from PBDE exposure to Chinook salmon health and recovery efforts, as well as to their predators.

  13. On non-coplanar Hohmann Transfer using angles as parameters

    CERN Document Server

    Rincon, Angel; Lacruz, Elvis; Abellan, Gabriel; Diaz, Sttiwuer

    2015-01-01

    We study a more complex case of Hohmann orbital transfer of a satellite by considering non-coplanar and elliptical orbits, instead of planar and circular orbits. We use as parameter the angle between the initial and transference planes that minimizes the energy, and therefore the fuel of a satellite, through the application of two non-tangential impulses for all possible cases. We found an analytical expression that minimizes the energy for each configuration. Some reasonable physical constraints are used: we apply impulses at perigee or apogee of the orbit, we consider the duration of the impulse to be short compared to the duration of the trip, we take the nodal line of three orbits to be coincident and the three semimajor axes to lie in the same plane. We study the only four possible cases but assuming non-coplanar elliptic orbits. In addition, we validate our method through a numerical solution obtained by using some of the actual orbital elements of Sputnik I and Vanguard I satellites. For these orbits, ...

  14. Laser Vision Measurement System and Assessment Method for SMIC Lead Coplanarity

    Institute of Scientific and Technical Information of China (English)

    SUN Changku; QIU Yu; XUE Xiaojie; YE Shenghua

    2000-01-01

    In this paper, a successful application of line-structured laser sensor, involved in SMIC chip lead coplanarity measurement, is presented. With the experimental measurement system and its corresponding mathematics model, a contact-datum-plane assessment of SMIC chip lead coplanarity is developed to provide method for on-line measurement.

  15. Calculation of S11 Parameter of Coplanar Strip and Influence of Technology Process

    Directory of Open Access Journals (Sweden)

    Karel Heindl

    2006-01-01

    Full Text Available The paper is focused on a calculation of the S11 parameter of the coplanar strips. The primary parameterscalculations of the coplanar strips are described in the first part. The scattering parameters are defined. The calculation of the S11 parameter and the comparison with the measured values are showed in the last part of the work.

  16. Energy flow analysis of out-of-plane vibration in coplanar coupled finite Mindlin plates

    Directory of Open Access Journals (Sweden)

    Park Young-Ho

    2015-01-01

    Full Text Available In this paper, an Energy Flow Analysis (EFA for coplanar coupled Mindlin plates was performed to estimate their dynamic responses at high frequencies. Mindlin plate theory can consider the effects of shear distortion and rotatory inertia, which are very important at high frequencies. For EFA for coplanar coupled Mindlin plates, the wave transmission and reflection relationship for progressing out-of-plane waves (out-of-plane shear wave, bending dominant flexural wave, and shear dominant flexural wave in coplanar coupled Mindlin plates was newly derived. To verify the validity of the EFA results, numerical analyses were performed for various cases where coplanar coupled Mindlin plates are excited by a harmonic point force, and the energy flow solutions for coplanar coupled Mindlin plates were compared with the classical solutions in the various conditions.

  17. Be discs in binary systems I. Coplanar orbits

    CERN Document Server

    Panoglou, Despina; Vieira, Rodrigo G; Cyr, Isabelle H; Jones, Carol E; Okazaki, Atsuo T; Rivinius, Thomas

    2016-01-01

    Be stars are surrounded by outflowing circumstellar matter structured in the form of decretion discs. They are often members of binary systems, where it is expected that the decretion disc interacts both radiatively and gravitationally with the companion. In this work we study how various orbital (period, mass ratio, eccentricity) and disc (viscosity) parameters affect the disc structure in coplanar systems. We simulate such binaries with the use of a smoothed particle hydrodynamics code. The main effects of the secondary on the disc are its truncation and the accumulation of material inwards of truncation. In circular or nearly circular prograde orbits, the disc maintains a rotating, constant in shape, configuration, which is locked to the orbital phase. The disc is smaller in size, more elongated and more massive for low viscosity parameter, small orbital separation and/or high mass ratio. Highly eccentric orbits are more complex, with the disc structure and total mass strongly dependent on the orbital phas...

  18. Magnetic hysteresis effects in superconducting coplanar microwave resonators

    Energy Technology Data Exchange (ETDEWEB)

    Bothner, D.; Gaber, T.; Kemmler, M.; Gruenzweig, M.; Ferdinand, B.; Koelle, D.; Kleiner, R. [Universitaet Tuebingen (Germany); Wuensch, S.; Siegel, M. [Karlsruher Institut fuer Technologie (Germany); Mikheenko, P.; Johansen, T.H. [University of Oslo (Norway)

    2013-07-01

    We present experimental data regarding the impact of external magnetic fields on quality factor and resonance frequency of superconducting microwave resonators in a coplanar waveguide geometry. In particular we focus on the influence of magnetic history and show with the assistance of numerical calculations that the found hysteretic behaviour can be well understood with a highly inhomogeneous microwave current density in combination with established field penetration models for type-II superconducting thin films. Furthermore we have used magneto-optical imaging techniques to check the field distribution which we have assumed in our calculations. Finally, we demonstrate that and how the observed hysteretic behaviour can be used to optimize and tune the resonator performance for possible hybrid quantum sytems in magnetic fields.

  19. Optimized Coplanar Waveguide Resonators for a Superconductor-Atom Interface

    CERN Document Server

    Beck, M A; Booth, D; Pritchard, J D; Saffman, M; McDermott, R

    2016-01-01

    We describe the design and characterization of superconducting coplanar waveguide cavities tailored to facilitate strong coupling between superconducting quantum circuits and single trapped Rydberg atoms. For initial superconductor-atom experiments at 4.2 K, we show that resonator quality factors above $10^4$ can be readily achieved. Furthermore, we demonstrate that the incorporation of thick-film copper electrodes at a voltage antinode of the resonator provides a route to enhance the zero-point electric fields of the resonator in a trapping region that is 40 $\\mu$m above the chip surface, thereby minimizing chip heating from scattered trap light. The combination of high resonator quality factor and strong electric dipole coupling between the resonator and the atom should make it possible to achieve the strong coupling limit of cavity quantum electrodynamics with this system.

  20. In vitro toxicity profiling of ultrapure non-dioxin-like polychlorinated biphenyl congeners and their relative toxic contribution to PCB mixtures in humans.

    Science.gov (United States)

    Hamers, Timo; Kamstra, Jorke H; Cenijn, Peter H; Pencikova, Katerina; Palkova, Lenka; Simeckova, Pavlina; Vondracek, Jan; Andersson, Patrik L; Stenberg, Mia; Machala, Miroslav

    2011-05-01

    The toxic equivalency concept used for the risk assessment of polychlorinated biphenyls (PCBs) is based on the aryl hydrocarbon receptor (AhR)-mediated toxicity of coplanar dioxin-like (DL) PCBs. Most PCBs in the environment, however, are non-dioxin-like (NDL) PCBs that cannot adopt a coplanar structure required for AhR activation. For NDL-PCBs, no generally accepted risk concept is available because their toxicity is insufficiently characterized. Here, we systematically determined in vitro toxicity profiles for 24 PCBs regarding 10 different mechanisms of action. Prior to testing, NDL-PCB standards were purified to remove traces of DL compounds. All NDL-PCBs antagonized androgen receptor activation and inhibited gap junctional intercellular communication (GJIC). Lower chlorinated NDL-PCBs were weak estrogen receptor (ER) agonists, whereas higher chlorinated NDL-PCBs were weak ER antagonists. Several NDL-PCBs inhibited estradiol-sulfotransferase activity and bound to transthyretin (TTR) but with much weaker potencies than reported for hydroxylated PCB metabolites. AhR-mediated expression of uridine-glucuronyl transferase isozyme UGT1A6 was induced by DL-PCBs only. Hierarchical cluster analysis of the toxicity profiles yielded three separate clusters of NDL-PCBs and a fourth cluster of reference DL-PCBs. Due to small differences in relative potency among congeners, the highly abundant indicator PCBs 28, 52, 101, 118, 138, 153, and 180 also contributed most to the antiandrogenic, (anti)estrogenic, antithyroidal, tumor-promoting, and neurotoxic potencies calculated for PCB mixtures reported in human samples, whereas the most potent AhR-activating DL-PCB-126 contributed at maximum 0.2% to any of these calculated potencies. PCB-168 is recommended as an additional indicator congener, given its relatively high abundance and antiandrogenic, TTR-binding, and GJIC-inhibiting potencies.

  1. Ionisation differential cross section measurements for N2 at low incident energy in coplanar and non-coplanar geometries

    Science.gov (United States)

    Sakaamini, Ahmad; Amami, Sadek; Murray, Andrew James; Ning, Chuangang; Madison, Don

    2016-10-01

    Ionisation triple differential cross sections have been determined experimentally and theoretically for the neutral molecule N2 over a range of geometries from coplanar to the perpendicular plane. Data were obtained at incident electron energies ∼10 and ∼20 eV above the ionisation potential of the 3σ g, 1π u and 2σ g states, using both equal and non-equal outgoing electron energies. The data were taken with the incident electron beam in the scattering plane (ψ = 0°), at 45° to this plane and orthogonal to the plane (ψ = 90°). The set of nine measured differential cross sections at a given energy were then inter-normalised to each other. The data are compared to new calculations using various distorted wave methods, and differences between theory and experiment are discussed.

  2. Electrode Design of Cylindrical Coplanar-grid CdZnTe Detector by Finite Element Methods

    Institute of Scientific and Technical Information of China (English)

    JIN Wei; SANG Wen-bin; ZHANG Qi; MIN Jia-Hua; SHEN Yan

    2004-01-01

    Cylindrical coplanar- grid configurations, which offer a lot of advantages over established designs,can effectively overcome the problem of poor hole collection. Finite element analysis is utilized for simulating the potential distribution of the cylindrical coplanar-grid detector under different models by varying the widths of grid and pitch of electrodes. In addition, a modified grid pattern has been discussed to improve the weighting potential match between two grids. In this way, the geometry of electrodes for cylindrical coplanar- grid detectors is optimized.

  3. Grounded coplanar waveguide defected ground structure enabled mulitlayered passive circuits

    Science.gov (United States)

    Schlieter, Daniel Benjamin

    Passive circuits are essential to microwave and millimeter-wave (mm-wave) frequency design, especially as new commercial applications emerge for complementary metal-oxide semiconductor (CMOS) integrated circuits. However, it is challenging to design distributed passive circuits for CMOS due to the substrate loss and thin dielectric layers of the back-end-of-line (BEOL). Furthermore, distributed passive circuits need to be adapted for compactness and integration while overcoming these challenges and maintaining high performance. Grounded coplanar waveguide defected ground structures meet this need for compact and integrable passive circuits by utilizing the top and bottom ground planes of the transmission line to implement circuit elements. Defected ground structures (DGS) are distributed elements realized by etching specific patterns into the ground planes of transmission lines. These structures can be used in conjunction with the center conductor of planar transmission lines to reduce circuit size and/or improve performance. By implementing DGS in grounded coplanar waveguide (GCPW) multiple resonances and higher impedances can be achieved. The resonant-based GCPW DGS are more compact than their microstrip and CPW counterparts and fit well into the vertical technology of back-end-of-line CMOS. This research demonstrates up to 80% size reduction at 5.8GHz by realizing spiral-shaped DGS in GCPW and applying the resulting GCPW DGS unit cell to a dual-behavior band-pass filter. The filter has been scaled to 60GHz and realized in a 130nm CMOS process by using floating metal strips to reduce the impact of the lossy silicon substrate. The impedance-based GCPW DGS, called EG-GCPW, have up to a 20:1 impedance ratio on Rogers RT/DuroidRTM 5880 and an impedance ratio of 15:1 on a benzocyclobutene post-CMOS process. These high impedance ratios increased the power division ratio of an unequal Wilkinson power divider to 7:1 and reduced the size of a stepped impedance low

  4. Carbon dioxide conversion by means of coplanar dielectric barrier discharges

    Science.gov (United States)

    Schiorlin, Milko; Klink, Rouven; Brandenburg, Ronny

    2016-08-01

    To face the worldwide problem of anthropogenic carbon dioxide (CO2) emission new techniques have to be developed. One approach for carbon capture utilization (CCU) is the conversion of CO2 to more valuable chemicals, e.g., carbon monoxide (CO) by means of non-thermal plasma generated at ambient conditions and supplied by excess energy from renewable sources. This paper reports about the effect of the admixture of inert gases, namely nitrogen or argon to CO2 in a coplanar dielectric barrier discharge (DBD). Systematic experiments were conducted to investigate the effects of applied voltage, frequency, flowrate and CO2 concentration in the influent. The composition of products, energy efficiency and yield were determined. Within the investigated parameter ranges, the maximum conversion of CO2 to CO efficiency of 1% was achieved when the specific input energy was 190 J L-1, whereas the maximum CO yield of 0.7% was achieved when the specific input energy was 210 J L-1. In conclusion, the energy efficiency can be significantly increased by operating the plasma in a diluted CO2 gas. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

  5. Optimization and experimental verification of coplanar interdigital electroadhesives

    Science.gov (United States)

    Guo, J.; Bamber, T.; Chamberlain, M.; Justham, L.; Jackson, M.

    2016-10-01

    A simplified and novel theoretical model for coplanar interdigital electroadhesives has been presented in this paper. The model has been verified based on a mechatronic and reconfigurable testing platform, and a repeatable testing procedure. The theoretical results have shown that, for interdigital electroadhesive pads to achieve the maximum electroadhesive forces on non-conductive substrates, there is an optimum electrode width/space between electrodes (width/space) ratio, approximately 1.8. On conductive substrates, however, the width/space ratio should be as large as possible. The 2D electrostatic simulation results have shown that, the optimum ratio is significantly affected by the existence of the air gap and substrate thickness variation. A novel analysis of the force between the electroadhesive pad and the substrate has highlighted the inappropriateness to derive the normal forces by the division of the measured shear forces and the friction coefficients. In addition, the electroadhesive forces obtained in a 5 d period in an ambient environment have highlighted the importance of controlling the environment when testing the pads to validate the models. Based on the confident experimental platform and procedure, the results obtained have validated the theoretical results. The results are useful insights for the investigation into environmentally stable and optimized electroadhesives.

  6. Coplanar (, 3) differential cross-section of He atom

    Indian Academy of Sciences (India)

    R Choubisa; A S Bhullar; K K Sud

    2003-06-01

    We present in this paper the results of our calculation of five-fold differential cross-section (FDCS) for (, 3) process on He atom in low momentum transfer and high electron impact energy in shake-off mechanism. The formalism has been developed in Born approximation using plane waves, Byron and Joachain as well as Le Sech and correlated BBK-type wave functions respectively for incident and scattered, bound and ejected electrons. The angular distribution of FDCS of our calculation is presented in various modes of coplanar geometry and comparison is made with the available experimental data. We observe that the present calculation is able to reproduce the trend of the experimental data. However, it differs in magnitude from the experiment. The present theory does not predict four-peak structure in summed mutual angle mode for lower excess ejected electron energies. We also discuss the importance of momentum transfer, post-collision interaction (PCI) and ion participation in the (, 3) process in constant 12 mode.

  7. Coplanar three-beam interference and phase edge dislocations

    Science.gov (United States)

    Patorski, Krzysztof; SłuŻewski, Łukasz; Trusiak, Maciej; Pokorski, Krzysztof

    2016-12-01

    We present a comprehensive analysis of grating three-beam interference to discover a broad range of the ratio of amplitudes A of +/-1 diffraction orders and the zero order amplitude C providing phase edge dislocations. We derive a condition A/C > 0.5 for the occurrence of phase edge dislocations in three-beam interference self-image planes. In the boundary case A/C = 0.5 singularity conditions are met in those planes (once per interference field period), but the zero amplitude condition is not accompanied by an abrupt phase change. For A/C > 0.5 two adjacent singularities in a single field period show opposite sign topological charges. The occurrence of edge dislocations for selected values of A/C was verified by processing fork fringes obtained by introducing the fourth beam in the plane perpendicular to the one containing three coplanar diffraction orders. Two fork pattern processing methods are described, 2D CWT (two-dimensional continuous wavelet transform) and 2D spatial differentiation.

  8. Coplanar back contacts for thin silicon solar cells

    Science.gov (United States)

    Storti, G.; Scheinine, A.; Whitehouse, D.; Wohlgemuth, J.; Wrigley, C.; Giuliano, M.

    1981-01-01

    The type of coplanar back contact solar cell described was constructed with interdigitated n(+) and p(+) type regions on the back of the cell, such that both contacts are made on the back with no metallization grid on the front. This cell construction has several potential advantages over conventional cells for space use namely, convenience of interconnects, lower operating temperatures and higher efficiency due to the elimination of grid shadowing. However, the processing is more complex, and the cell is inherently more radiation sensitive. The latter problem can be reduced substantially by making the cells very thin (approximately 50 micrometers). Two types of interdigitated back contact cells are possible, the types being dependent on the character of the front surface. The front surface field cell has a front surface region that is of the same conductivity type as the bulk but is more heavily doped. This creates an electric field at the surface which repels the minority carriers. The tandem junction cell has a front surface region of a conductivity type that is opposite to that of the bulk. The junction thus created floats to open circuit voltage on illumination and injects carriers into the bulk which then can be collected at the rear junction. For space use, the front surface field cell is potentially more radiation resistant than the tandem junction cell because the flow of minority carriers (electrons) into the bulk will be less sensitive to the production of recombination centers, particularly in the space charge region at the front surface.

  9. Limits of dose escalation in lung cancer: a dose-volume histogram analysis comparing coplanar and non-coplanar techniques

    Energy Technology Data Exchange (ETDEWEB)

    Derycke, S.; Van Duyse, B.; Schelfhout, J.; De Neve, W.

    1995-12-01

    To evaluate the feasibility of dose escalation in radiotherapy of inoperable lung cancer, a dose-volume histogram analysis was performed comparing standard coplanar (2D) with non-coplanar (3D) beam arrangements on a non-selected group of 20 patients planned by Sherouse`s GRATISTM 3D-planning system. Serial CT-scanning was performed and 2 Target Volumes (Tvs) were defined. Gross Tumor Volume (GTV) defined a high-dose Target Volume (TV-1). GTV plus location of node stations with > 10% probability of invasion (Minet et al.) defined an intermediate-dose Target Volume (TV-2). However, nodal regions which are incompatible with cure were excluded from TV-2. These are ATS-regions 1, 8, 9 and 14 all left and right as well as heterolateral regions. For 3D-planning, Beam`s Eye View selected (by an experienced planner) beam arrangements were optimised using Superdot, a method of target dose-gradient annihilation developed by Sherouse. A second 3D-planning was performed using 4 beam incidences with maximal angular separation. The linac`s isocenter for the optimal arrangement was located at the geometrical center of gravity of a tetraheder, the tetraheder`s comers being the consecutive positions of the virtual source. This ideal beam arrangement was approximated as close as possible, taking into account technical limitations (patient-couch-gantry collisions). Criteria for tolerance were met if no points inside the spinal cord exceeded 50 Gy and if at least 50% of the lung volume received less than 20Gy. If dose regions below 50 Gy were judged acceptable at TV-2, 2D- as well as 3D-plans allow safe escalation to 80 Gy at TV-1. When TV-2 needed to be encompassed by isodose surfaces exceeding 50Gy, 3D-plans were necessary to limit dose at the spinal cord below tolerance. For large TVs dose is limited by lung tolerance for 3D-plans. An analysis (including NTCP-TCP as cost functions) of rival 3D-plans is being performed.

  10. Design aspects and comparison between high Tc superconducting coplanar waveguide and microstrip line

    Science.gov (United States)

    Kong, K. S.; Bhasin, K. B.; Itoh, T.

    1991-01-01

    The high T sub c superconducting microstrip line and coplanar waveguide are compared in terms of the loss characteristics and the design aspects. The quality factor Q values for each structure are compared in respect to the same characteristic impedance with the comparable dimensions of the center conductor of the coplanar waveguide and the strip of the microstrip line. Also, the advantages and disadvantages for each structure are discussed in respect to passive microwave circuit applications.

  11. Design aspects and comparison between high T(sub c) superconducting coplanar waveguide and microstrip line

    Science.gov (United States)

    Kong, K. S.; Bhasin, K. B.; Itoh, T.

    1991-01-01

    The high T sub c superconducting microstrip line and coplanar waveguide are compared in terms of the loss characteristics and the design aspects. The quality factor Q values for each structure are compared in respect to the same characteristic impedance with the comparable dimensions of the center conductor of the coplanar waveguide and the strip of the microstrip line. Also, the advantages and disadvantages for each structure are discussed in respect to passive microwave circuit applications.

  12. Inhibitory effects of whisky congeners on melanogenesis in mouse B16 melanoma cells.

    Science.gov (United States)

    Ohguchi, Kenji; Koike, Minako; Suwa, Yoshihide; Koshimizu, Seiichi; Mizutani, Yuki; Nozawa, Yoshinori; Akao, Yukihiro

    2008-04-01

    We examined the effect of whisky congeners, substances other than ethanol in whisky, on melanogenesis in mouse B16 melanoma cells. Treatment with whisky congeners significantly blocked melanogenesis. Our results indicate that the inhibitory effects of whisky congeners on melanogenesis is due to direct inhibition of tyrosinase activity and to suppression of tyrosinase protein levels.

  13. Hot Jupiters from Coplanar High-eccentricity Migration

    Science.gov (United States)

    Petrovich, Cristobal

    2015-05-01

    We study the possibility that hot Jupiters (HJs) are formed through the secular gravitational interactions between two planets in eccentric orbits with relatively low mutual inclinations (≲ 20{}^\\circ ) and friction due to tides raised on the planet by the host star. We term this migration mechanism Coplanar High-eccentricity Migration (CHEM) because, like disk migration, it allows for migration to occur on the same plane in which the planets formed. CHEM can operate from the following typical initial configurations: (i) the inner planet in a circular orbit and the outer planet with an eccentricity ≳ 0.67 for {{m}in}/{{m}out}{{({{a}in}/{{a}out})}1/2}≲ 0.3; (ii) two eccentric (≳ 0.5) orbits for {{m}in}/{{m}out}{{({{a}in}/{{a}out})}1/2}≲ 0.16. A population synthesis study of hierarchical systems of two giant planets using the observed eccentricity distribution of giant planets shows that CHEM produces HJs with low stellar obliquities (≲ 30{}^\\circ ), with a semi-major axis distribution that matches the observations, and at a rate that can account for their observed occurrence. A different mechanism is needed to create large obliquity HJs, either a different migration channel or a mechanism that tilts the star or the protoplanetary disk. CHEM predicts that HJs should have distant (a≳ 5 AU) and massive (most likely ˜1-3 times more massive than the HJ) companions with relatively low mutual inclinations (≲ 20{}^\\circ ) and moderately high eccentricities (e˜ 0.2-0.5).

  14. Bioaccumulation of toxaphene congeners in the lake superior food web

    Science.gov (United States)

    Muir, D.C.G.; Whittle, D.M.; De Vault, D. S.; Bronte, C.R.; Karlsson, H.; Backus, S.; Teixeira, C.

    2004-01-01

    The bioaccumulation and biotransformation of toxaphene was examined in the food webs of Lake Superior and Siskiwit Lake (Isle Royale) using congener specific analysis as well as stable isotope ratios of carbon and nitrogen to characterize food webs. Toxaphene concentrations (calculated using technical toxaphene) in lake trout (Salvelinus namaycush) from the western basin of Lake Superior (N = 95) averaged (±SD) 889 ± 896 ng/g wet wt and 60 ± 34 ng/g wet wt in Siskiwit Lake. Major congeners in lake trout were B8-789 (P38), B8-2226 (P44), B9-1679 (P50), and B9-1025 (P62). Toxaphene concentrations were found to vary seasonally, especially in lower food web organisms in Lake Superior and to a lesser extent in Siskiwit Lake. Toxaphene concentrations declined significantly in lake herring (Coregonus artedii), rainbow smelt (Omerus mordax), and slimy sculpin (Cottus cognatus) as well as in zooplankton (> 102 &mn;m) and Mysis (Mysis relicta) between May and October. The seasonal variation may reflect seasonal shifts in the species abundance within the zooplankton community. Trophic magnification factors (TMF) derived from regressions of toxaphene congener concentrations versus δ15N were > 1 for most octa- and nonachlorobornanes in Lake Superior except B8-1413 (P26) and B9-715. Log bioaccumulation factors (BAFs) for toxaphene congeners in lake trout (ng/g lipid/ng/L dissolved) ranged from 4.54 to 9.7 and were significantly correlated with log octanol-water partition coefficients. TMFs observed for total toxaphene and congener B9-1679 in Lake Superior were similar to those in Arctic lakes, as well as to previous studies in the Great Lakes, which suggests that the bioaccumulation behavior of toxaphene is similar in pelagic food webs of large, cold water systems. However, toxaphene concentrations were lower in lake trout from Siskiwit Lake and lakes in northwestern Ontario than in Lake Superior possibly because of shorter food chains and greater reliance on zooplankton or

  15. Usefulness of Non-coplanar Helical Tomotherapy Using Variable Axis Baseplate

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jin Sook; Chung, Yoon Sun; Lee, Ik Jae; Shin, Dong Bong; Kim, Jong Dae; Kim, Sei Joon; Jeon, Mi Jin; Chok, Yoon Jin; Kim, Ki Kwang; Lee, Seul Bee [Dept. of Radiation Oncology, Gangnam Severance Hospital, Seoul (Korea, Republic of)

    2011-03-15

    Helical Tomotherapy allows only coplanar beam delivery because it does not allow couch rotation. We investigated a method to introduce non-coplanar beam by tilting a patient's head for Tomotherapy. The aim of this study was to compare intrafractional movement during Tomotherapy between coplanar and non-coplanar patient's setup. Helical Tomotherapy was used for treating eight patients with intracranial tumor. The subjects were divided into three groups: one group (coplanar) of 2 patients who lay on S-plate with supine position and wore thermoplastic mask for immobilizing the head, second group (non-coplanar) of 3 patients who lay on S-plate with supine position and whose head was tilted with Variable Axis Baseplate and wore thermoplastic mask, and third group (non-coplanar plus mouthpiece) of 3 patients whose head was tilted and wore a mouthpiece immobilization device and thermoplastic mask. The patients were treated with Tomotherapy after treatment planning with Tomotherapy Planning System. Megavoltage computed tomography (MVCT) was performed before and after treatment, and the intrafractional error was measured with lateral(X), longitudinal(Y), vertical(Z) direction movements and vector ({radical}x{sup 2}+{radical}y{sup 2}+{radical}z{sup 2}) value for assessing overall movement. Intrafractional error was compared among three groups by taking the error of MVCT taken after the treatment. As the correction values (X, Y, Z) between MVCT image taken after treatment and CT-simulation image are close to zero, the patient movement is small. When the mean values of movement of each direction for non-coplanar setup were compared with coplanar setup group, X-axis movement was decreased by 13%, but Y-axis and Z-axis movement were increased by 109% and 88%, respectively. Movements of Y-axis and Z-axis with non-coplanar setup were relatively greater than that of X-axis since a tilted head tended to slip down. The mean of X-axis movement of the group who used a

  16. Evaluation of the accuracy of the HexaPOD evo RT system using non-coplanar beams in lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Se Wuk; Cho, Kang Chul; Lee, Sang Kyoo; Kim, Joo Ho; Cho, Jeong Hee [Dept. of Radiation Oncology, Yonsei Cancer Center, Seoul (Korea, Republic of)

    2015-12-15

    The aim of this study, evaluate the accuracy of HeaxPOD evo RT system using the non-coplanar beam. 13 treatment plans are used which applied non-coplanar beams and 10 treatment plans which coplanar beams are used. the correction value what adjust to 6D couch is determined by each patient's setup errors only rotation direction. The study executed followings. first, Applying the correction value, measure the point dose and calculate the γ -index(γ=3% / 3 mm , γ =2%/ 2 mm). second, acquire data as previous methods without correction by HexaPOD. For comparing the two results, we find out the more precise applying HexaPOD by point dose 0.2% in coplanar and non-coplanar. in the case of γ-index<1(γ=3% / 3 mm), more precise 2.2% in coplanar and 7% in Non-coplanar. Particularly, γ - index<1(2% / 2 mm) show the difference 9.2% in coplanar and 15.1% non-coplanar between apply HexaPOD and dose not apply HexaPOD. Using the HexaPOD is more precise than without HexaPOD. It suggests that HexaPOD evo RT system is very useful for precise and high dose delivery.

  17. Non-coplanar volumetric-modulated arc therapy (VMAT) for craniopharyngiomas reduces radiation doses to the bilateral hippocampus: A planning study comparing dynamic conformal arc therapy, coplanar VMAT, and non-coplanar VMAT

    OpenAIRE

    Uto, Megumi; Mizowaki, Takashi; OGURA, KENGO; Hiraoka, Masahiro

    2016-01-01

    Background Recent studies suggest that radiation-induced injuries to the hippocampus play important roles in compromising neurocognitive functioning for patients with brain tumors and it could be important to spare the hippocampus using modern planning methods for patients with craniopharyngiomas. As bilateral hippocampus are located on the same level as the planning target volume (PTV) in patients with craniopharyngioma, it seems possible to reduce doses to hippocampus using non-coplanar bea...

  18. Assessment of the toxic potential of PCB congener 81 (3,4,4[prime],5-tetrachlorobiphenyl) to fish in relation to other non-ortho-substituted PCB congeners

    Energy Technology Data Exchange (ETDEWEB)

    Harris, G.E.; Kiparissis, Y.; Metcalfe, C.D. (Trent Univ., Peterborough, Ontario (Canada). Environmental and Resource Studies Program)

    1994-09-01

    PCB congener 81 (3,4,4[prime],5-tetrachlorobiphenyl) has been detected in fish tissues from various sites in North America. The embryotoxicity of this compound to medaka (Oryzias latipes) and the induction of hepatic aryl hydrocarbon hydroxylase (AHH) in rainbow trout (Oncorhynchus mykiss) were determined to assess the toxic potency of this compound relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and two other non-ortho-substituted PCB compounds, congener 77 (3,3[prime],4,4[prime]-tetrachlorobiphenyl) and congener 126 (3,3[prime],4,4[prime],5-pentachlorobiphenyl). The TCDD toxic equivalency factors (TEFs) estimated for congener 81 from two end points in the medaka embryotoxicity assay were 0.0014 (from mortality data) and 0.006 (from swim bladder inflation data). The TEF estimated for congener 81 from data on AHH induction in rainbow trout was 0.004. All TEFs were greater than those estimated for congener 77 but were less than the TEFs estimated for congener 126. On the basis of these toxicity data, it is suggested that this congener may contribute significantly to the toxic burden of planar halogenated aromatic hydrocarbon in fish.

  19. Eccentricity generation in hierarchical triple systems with non-coplanar and initially circular orbits

    CERN Document Server

    Georgakarakos, Nikolaos

    2014-01-01

    In a previous paper, we developed a technique for estimating the inner eccentricity in coplanar hierarchical triple systems on initially circular orbits, with comparable masses and with well separated components, based on an expansion of the rate of change of the Runge-Lenz vector. Now, the same technique is extended to non-coplanar orbits. However, it can only be applied to systems with ${I_{0}140.77^{\\circ}}$, where ${I}$ is the inclination of the two orbits, because of complications arising from the so-called 'Kozai effect'. The theoretical model is tested against results from numerical integrations of the full equations of motion.

  20. Levels and congener distributions of PCDDs, PCDFs and non-ortho PCBs in Belgian foodstuffs--assessment of dietary intake.

    Science.gov (United States)

    Focant, J F; Eppe, G; Pirard, C; Massart, A C; André, J E; De Pauw, E

    2002-07-01

    Congener-specific analyses of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs) and 4 non-ortho (coplanar) polychlorinated biphenyls (cPCBs) were performed on 197 foodstuffs samples of animal origin from Belgium during years 2000 and 2001. All investigated matrices (except horse) present background levels lower than the Belgian non-commercialization value of 5 pg TEQ/g fat. Pork was the meat containing the lowest concentration of both PCDD/Fs and cPCBs. The mean background concentration of 2,3,7,8-TCDD toxicity equivalent in milk was 1.1 pg/g of fat, with a congener distribution typical of non-contaminated milk. The relative contribution of 2,3,7,8-TCDD, 2,3,7,8-TCDF, 1,2,3,7,8-PeCDD and 2,3,4,7,8-PeCDF to the PCDD/Fs TEQ was 85+/-7.9% for all investigated matrices. The cPCBs contribution to the total TEQ was 47+/-19.0% for products of terrestrial species and 69+/-20.0% for aquatic species. Once the contribution of cPCBs was added to the TEQ, few foodstuffs such as horse, sheep, beef, eggs and cheese presented levels above the future European guidelines that currently only include PCDD/Fs but will be re-evaluated later in order to include 'dioxin-like' PCBs. Based on levels measured in the samples, the estimation of the dietary intake was 65.3 pg WHO-TEQ/day for PCDD/Fs only (1.00 pg WHO-TEQ/kg bw/day, for a 65 kg person) and 132.9 pg WHO-TEQ/day if cPCBs were included (2.04 pg WHO-TEQ/kg bw/day, for a 65 kg person). Meat (mainly beef), dairy products, and fish each account for roughly one third of the intake.

  1. Incubation stage and polychlorinated biphenyl (PCB) congener patterns in an altricial and precocial bird species.

    Science.gov (United States)

    Custer, Christine M; Custer, Thomas W; Thyen, Stefan; Becker, Peter H

    2014-12-01

    The composition of polychlorinated biphenyl (PCB) congeners was compared between non-incubated and embryonated eggs of tree swallows (Tachycineta bicolor) and little terns (Sterna albifrons) to determine if measurable changes in PCB congeners occurred during the embryonic period. There was no indication of changes in PCB congener patterns over the incubation period in tree swallows in 1999 and 2000 at a site with very high PCB exposure or a site with more modest PCB exposure. Additionally, congeners known to be either quickly metabolized or conserved based on experimental studies did not generally respond as predicted. Similarly, PCB congener patterns in eggs of little terns from Bottsand, Schleswig-Holstein, Germany, did not differ between non-incubated and embryonated eggs. The results from both species suggest that the stage of incubation is not an important consideration when evaluating PCB congener patterns; comparisons and assessments can be made with eggs collected at all stages of incubation.

  2. The Optimal Price Policy of Congener Software Product

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    From the viewpoint of market behavior to a certain softwaredevelopment company, it's very important to decide the suitable price to deploy its product. Especially face to the opponents who sale the congener product in the current market. According to the requirement of market economy and software engineering , accurate estimation of software price and its amount of sales are useful to a certain software provider to build a proper development project and software pro ducts' target parameters. Here we analysis the factors which affect the price of the congener software product in the same market, and calculate the weight of t hese factors to it's price on the current market. With the help of principles of the non-cooperative games, we built a model base on AHP methods. Use this model , we can get the optimal price to release our software product and the biggest turnover. At the end of this paper, we use a numerical example to explain how to use our model

  3. 3D printed biomimetic whisker-based sensor with co-planar capacitive sensing

    NARCIS (Netherlands)

    Delamare, John; Sanders, Remco; Krijnen, Gijs

    2016-01-01

    This paper describes the development of a whisker sensor for tactile purposes and which is fabricated by 3D printing. Read-out consists of a capacitive measurement of a co-planar capacitance which is affected by a dielectric that is driven into the electric field of the capacitance. The current impl

  4. Characterisation and optimisation of a coplanar waveguide fed logarithmic spiral antenna

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne; Appel-Hansen, Jørgen

    2000-01-01

    A cavity backed coplanar waveguide (CPW) to coplanar strip (CPS)-fed logarithmic uniplanar spiral antenna, which covers a 9 to 1 bandwidth with a return loss better than 10 dB from 0.4 to 3.8 GHz is presented. A wideband balun is used to accomplish the transition from the unbalanced CPW transmiss......A cavity backed coplanar waveguide (CPW) to coplanar strip (CPS)-fed logarithmic uniplanar spiral antenna, which covers a 9 to 1 bandwidth with a return loss better than 10 dB from 0.4 to 3.8 GHz is presented. A wideband balun is used to accomplish the transition from the unbalanced CPW...... pattern, due to the absorbing material. Only half of the input power is transformed into radiated power due to the presence of the absorber. The simulated performance of the spiral antenna is very promising. The simulations indicated that the antenna has a radiation efficiency of more than 70...

  5. Measuring the complex permittivity tensor of uniaxial biological materials with coplanar waveguide transmission line

    Science.gov (United States)

    A simple and accurate technique is described for measuring the uniaxial permittivity tensor of biological materials with a coplanar waveguide transmission-line configuration. Permittivity tensor results are presented for several chicken and beef fresh meat samples at 2.45 GHz....

  6. Design and modeling of inductors, capacitors and coplanar waveguides at tens of GHz frequencies

    CERN Document Server

    Aryan, Naser Pour

    2015-01-01

    This book describes the basic principles of designing and modelling inductors, MIM capacitors and coplanar waveguides at frequencies of several tens of GHz. The author explains the design and modelling of key, passive elements, such as capacitors, inductors and transmission lines that enable high frequency MEMS operating at frequencies in the orders of tens of GHz.

  7. 3D printed biomimetic whisker-based sensor with co-planar capacitive sensing

    NARCIS (Netherlands)

    Delamare, John; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

    2016-01-01

    This paper describes the development of a whisker sensor for tactile purposes and which is fabricated by 3D printing. Read-out consists of a capacitive measurement of a co-planar capacitance which is affected by a dielectric that is driven into the electric field of the capacitance. The current impl

  8. A comparison study of on-chip short pulse generation circuits based on a coplanar waveguide

    Institute of Scientific and Technical Information of China (English)

    邹焕; 耿永涛; 王平山; 李家胤

    2011-01-01

    A few traditional pulse-forming circuits are implemented in a commercial 0.13 μm digital complementary-metal-oxide-semiconductor (CMOS) technology. These circuits, based on a coplanar waveguide, are analyzed and compared through CadenceTM Spectre simulati

  9. Bio- and chemical syntheses of mangiferin and congeners.

    Science.gov (United States)

    Ehianeta, Teddy Stephen; Laval, Stéphane; Yu, Biao

    2016-09-10

    Mangiferin (2C-β-d-glucopyranosyl-1,3,6,7-tetrahydroxyxanthone) is a xanthone C-glycoside occurring in many plant species. Composed of a glucose unit C1→2 linked to a 1,3,6,7-tetrahydroxyxanthone aglycone, mangiferin exhibits a wide range of biological activities, which recently renewed its interest as a potential pharmacophore. Mangiferin is mainly isolated after extraction procedures from natural sources alongside with its isoforms isomangiferin, homomangiferin, and neomangiferin. However, enzymatic and chemical approaches have been developed to access these phytochemicals, which address the challenging construction of the C-glycosidic linkage. In addition, both approaches have been exploited to modify the aglycone and the sugar moiety in order to afford analogues with specific and improved pharmacological activities. Herein, we provide a comprehensive review on the biosynthesis and chemical synthesis of mangiferin and its congeners. © 2016 BioFactors, 42(5):445-458, 2016.

  10. Congenic mice: cutting tools for complex immune disorders.

    Science.gov (United States)

    Rogner, Ute C; Avner, Philip

    2003-03-01

    Autoimmune diseases are, in general, under complex genetic control and subject to strong interactions between genetics and the environment. Greater knowledge of the underlying genetics will provide immunologists with a framework for study of the immune dysregulation that occurs in such diseases. Ascertaining the number of genes that are involved and their characterization have, however, proven to be difficult. Improved methods of genetic analysis and the availability of a draft sequence of the complete mouse genome have markedly improved the outlook for such research, and they have emphasized the advantages of mice as a model system. In this review, we provide an overview of the genetic analysis of autoimmune diseases and of the crucial role of congenic and consomic mouse strains in such research.

  11. Polybrominated diphenyl ether congener (BDE-100) induces mitochondrial impairment.

    Science.gov (United States)

    Pereira, Lílian Cristina; de Souza, Alecsandra Oliveira; Dorta, Daniel Junqueira

    2013-06-01

    Brominated flame retardants are used in various consumer products to increase their resistance to fire and/or high temperatures. Polybrominated diphenyl ethers (PBDEs) are representatives of this class and among the most widely used congeners, and BDE-100 is produced on a large scale. There is a lack of toxicological data about these compounds, which has recently become a matter of concern to the scientific community. The mitochondria are recognized as the main energy-producing organelles, as well as playing a vital role in the maintenance of many cell functions. Therefore, mitochondria were used in the present work as an experimental model to evaluate the effects of the BDE-100 congeners at concentrations ranging from 0.1 μM to 50 μM. The results showed that high concentrations of BDE-100 were able to induce mitochondrial alterations. It was observed that the substance had an affinity for the hydrophilic portion of the mitochondrial membrane, as monitored by ANS, inhibiting the glutamate + malate-stimulated mitochondrial respiration and also inducing dissipation of the mitochondrial membrane potential, deregulation of calcium homoeostasis and mitochondrial swelling, the latter being insensitive to cyclosporin A (CsA) but partially inhibited by Ruthenium Red and N-ethyl maleimide. In addition, a significant reduction in mitochondrial ATP content was found, but on the other hand, no oxidative stress was observed after exposure of the mitochondria to BDE-100. These results show the key role of mitochondria in the cytotoxicity induced by BDE-100.

  12. Comparative developmental toxicity of planar PCB congeners by egg injection

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, D.J.; Melancon, M.J.; Eisemann, J.D.; Klein, P.N. [National Biological Service, Laurel, MD (United States). Patuxent Environmental Science Center

    1995-12-31

    The utility of egg injection studies for predicting potential embryotoxicity of PCBs and TCDD compares favorably with feeding studies. The effects of PCB congeners 3,3{prime}4,4{prime}-tetraCB (PCB 77), 2,3,3{prime},4,4{prime}-pentaCB (PCB 105), 3,3{prime},4,4{prime},5-pentaCB (PCB 126) and 2,2{prime},4,4{prime},5,5{prime}-hexaCB (PCB 153) were examined on embryonic development in chickens (Gallus gallus), northern bobwhite (Colinus virginianus), American kestrels (Falco sparverius), and common terns (Sterna hirundo) through hatching following air cell injections on day 4. The estimated LD{sub 50}s for these congeners in chickens were approximately 0.4 ppb, 2.6 ppb, 3326 ppb, and greater than 14,000 ppb, respectively; low effect levels (10--20% embryonic mortality) were 0.2 ppb, 1.2 ppb, 900 ppb, and 14,000 ppb respectively. The estimated LD{sub 50} for PCB 126 was 48 ppb for bobwhite, 65 ppb for American kestrels, and 104 ppb for common terns. The estimated LD{sub 50} for PCB 77 was 688 ppb for American kestrels. one or more hepatic microsomal cytochrome P450-linked monooxygenases including ethoxyresorufin-O-deethylase was assayed for each species. For PCB 126, the order of responsiveness of cytochrome P450 induction was: chicken > common tern > American kestrel > bobwhite, with chicken being approximately 100 times more responsive than common tern. These values are compared to existing Toxic Equivalency Factors (TEFs) including bioassay-derived ones.

  13. Global pollution monitoring of polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) using skipjack tuna as bioindicator

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, D.; Watanabe, M.; Subraminian, A.N.; Tanabe, S. [Ehime Univ. (Japan); Tanaka, H. [National Research Inst. of Fisheries and Environment of Inland Sea (Japan); Fillmann, G. [Fundacao Univ. Federal do Rio Grande (Brazil); Lam, P.K.S.; Zheng, G.J. [City Univ. of Hong Kong (Hong Kong); Muchtar, M.; Razak, H. [Indonesian Inst. of Sciences (Indonesia); Prudente, M. [De La Salle Univ. (Philippines); Chung, K. [Sungkyunkwan Univ. (Korea)

    2004-09-15

    Worldwide contamination by dioxins and related compounds, such as polychlorinated dibenzop- dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) representing persistent organic pollutants (POPs) have been of great concern due to their persistency in the environment, highly bioaccumulative nature and adverse effects on wildlife and humans. Several studies on air samples and marine organisms from open seas suggested a long range transport of these compounds through atomosphere. Although several investigators have monitored dioxins pollution in localized areas, information on the global distribution of dioxins which can explain their atomospheric transport, behavior and fate are still limited. Skipjack tuna is primarily distributed from offshore waters to open seas in tropical and temperate regions almost all over the world such as the Pacific, Atlantic and Indian Oceans6. This species is an important commercial fish and its ecology and biology has been well studied. Moreover, suitability of skipjack tuna for global monitoring of organic pollutants (DDTs, HCHs PBDEs, organotins, etc.) has been established in our previous report, indicating that migration pattern, growth stage and sex of these animals have no or little effect on the variations of POPs residue levels in their bodies. Hence this species reflected POPs pollution levels in seawater when and where they were collected, caused by the rapid equilibrium partitioning between seawater and body lipid. These facts made skipjack tuna a suitable bioindicator for monitoring the contamination status of dioxins and related compounds. The objectives of this study are to elucidate the global distribution of dioxins (PCDD/Fs and coplanar PCBs) in offshore waters and open seas, and to understand the transport and behaviour of these chemicals using skipjack tuna as bioindicator.

  14. Global pollution monitoring of polychlorinated dibenzo-p-dioxins (PCDDs), furans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) using skipjack tuna as bioindicator

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, D.; Watanabe, M.; Subraminian, A.N.; Tanabe, S. [Ehime Univ. (Japan); Tanaka, H. [National Research Inst. of Fisheries and Environment of Inland Sea (Japan); Fillmann, G. [Fundacao Univ. Federal do Rio Grande (Brazil); Lam, P.K.S.; Zheng, G.J. [City Univ. of Hong Kong (Hong Kong); Muchtar, M.; Razak, H. [Indonesian Inst. of Sciences (Indonesia); Prudente, M. [De La Salle Univ. (Philippines); Chung, K. [Sungkyunkwan Univ. (Korea)

    2004-09-15

    Worldwide contamination by dioxins and related compounds, such as polychlorinated dibenzop- dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (coplanar PCBs) representing persistent organic pollutants (POPs) have been of great concern due to their persistency in the environment, highly bioaccumulative nature and adverse effects on wildlife and humans. Several studies on air samples and marine organisms from open seas suggested a long range transport of these compounds through atomosphere. Although several investigators have monitored dioxins pollution in localized areas, information on the global distribution of dioxins which can explain their atomospheric transport, behavior and fate are still limited. Skipjack tuna is primarily distributed from offshore waters to open seas in tropical and temperate regions almost all over the world such as the Pacific, Atlantic and Indian Oceans6. This species is an important commercial fish and its ecology and biology has been well studied. Moreover, suitability of skipjack tuna for global monitoring of organic pollutants (DDTs, HCHs PBDEs, organotins, etc.) has been established in our previous report, indicating that migration pattern, growth stage and sex of these animals have no or little effect on the variations of POPs residue levels in their bodies. Hence this species reflected POPs pollution levels in seawater when and where they were collected, caused by the rapid equilibrium partitioning between seawater and body lipid. These facts made skipjack tuna a suitable bioindicator for monitoring the contamination status of dioxins and related compounds. The objectives of this study are to elucidate the global distribution of dioxins (PCDD/Fs and coplanar PCBs) in offshore waters and open seas, and to understand the transport and behaviour of these chemicals using skipjack tuna as bioindicator.

  15. Half-life of each dioxin and PCB congener in the human body

    Energy Technology Data Exchange (ETDEWEB)

    Ogura, Isamura [National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan)

    2004-09-15

    It is well known that dioxin and PCB congeners accumulate in the human body. For assessing their toxicological risk, it is important to know the half-life of each congener in the human body. This study summarizes the overall half-lives of congeners in humans as reported in the literature, and compares them with the half-lives due to fecal and sebum excretions, as estimated by data on the concentrations of congeners in feces and sebum in the literature. In addition, the overall half-lives of congeners for the general Japanese population were estimated from the data on dietary intakes and concentrations in the human body reported by the municipalities.

  16. Superconducting Pb as material for coplanar waveguide resonators on GaAs substrates

    Energy Technology Data Exchange (ETDEWEB)

    Köpke, M., E-mail: m.koepke@fkf.mpg.de; Weis, J., E-mail: j.weis@fkf.mpg.de

    2014-11-15

    Highlights: • We investigate Pb as a material for superconducting coplanar waveguide resonators. • It is easily processed, has high T{sub C}, and high tolerance against magnetic fields. • Corrosion during aging is present, but shown to be acceptable. - Abstract: We investigate Pb as a material for superconducting coplanar waveguide resonators. It is easily fabricated, has relatively high tolerance against magnetic fields, and possesses high T{sub C}. It thus combines the advantages of the most widely used superconductors, Al and Nb, which is especially beneficial for experiments on (Al,Ga)As-based heterostructures. Its main disadvantage is corrosion during aging which we have shown to be present, but acceptable on GaAs substrates.

  17. Interactions of Nucleic Acid Bases with Temozolomide. Stacked, Perpendicular, and Coplanar Heterodimers.

    Science.gov (United States)

    Kasende, Okuma Emile; Nziko, Vincent de Paul N; Scheiner, Steve

    2016-09-01

    Temozolomide (TMZ) was paired with each of the five nucleic acid bases, and the potential energy surface searched for all minima, in the context of dispersion-corrected density functional theory and MP2 methods. Three types of arrangements were observed, with competitive stabilities. Coplanar H-bonding structures, reminiscent of Watson-Crick base pairs were typically the lowest in energy, albeit by a small amount. Also very stable were perpendicular arrangements that included one or more H-bonds. The two monomers were stacked approximately parallel to one another in the third category, some of which contained weak and distorted H-bonds. Dispersion was found to be a dominating attractive force, largest for the stacked structures, and smallest for the coplanar dimers.

  18. Study of Temperature Characteristics of Micromachined Suspended Coplanar Waveguides for Biosensing Applications

    Directory of Open Access Journals (Sweden)

    Lijie Li

    2011-03-01

    Full Text Available In the recent development on biosensors, coplanar waveguide based microwave dielectric sensors have been attracting more and more attentions. In this paper, microwave performance of a suspended coplanar waveguide subject to temperature variations, particularly in a small range, is studied. The prototype is realized through a MEMS fabrication foundry. The thermal transfer analysis of the device is conducted using finite element method, and the microwave properties of the device are characterized. One of the results shows that at 20 GHz, the S11 has decreased by 7.4%, and S21 has increased by 3.5% when the voltage applied to the heaters varies from 9 V to 29 V.

  19. Extraction of glass-wafers electrical properties based on S-parameters measurements of coplanar waveguides

    OpenAIRE

    Mendes, P. M.; Polyakov, A.; Bartek, M.; Burghartz, J.N.; Correia, J.H.

    2003-01-01

    The measured S-parameters of a coplanar waveguide (CPW) propagating the dominant mode were used to obtain the electrical permittivity and the dielectric loss tangent of three different glass wafers: non-alkaline Schott AF45, Corning Pyrex #7740 and Hoya SD-2. These properties were obtained up to 10 GHz. The obtained values were used together with the CPW model in ADS to obtain the simulated S-parameters for the used CPW cell. The obtained results shows good agreement b...

  20. Millimeter-wave integrated circuits based on novel probe microstrip line and coplanar stripline exciters

    OpenAIRE

    Iezhov, Oleksandr; Omelianenko, Mykhaylo

    2009-01-01

    Novel designs of compact integrated waveguide exciters of microstrip line and coplanar stipline are presented in the paper. An E-plane microstrip 0-π phase-shift modulator with independent p-i-n diode control networks has been designed at 24 GHz on the basis of proposed exciters. The total length of the integrated circuit substrate including exciters is no more than 0.62 of waveguide wavelength.

  1. Transparent, low-power pressure sensor matrix based on coplanar-gate graphene transistors.

    Science.gov (United States)

    Sun, Qijun; Kim, Do Hwan; Park, Sang Sik; Lee, Nae Yoon; Zhang, Yu; Lee, Jung Heon; Cho, Kilwon; Cho, Jeong Ho

    2014-07-16

    A novel device architecture for preparing a transparent and low-voltage graphene pressure-sensor matrix on plastic and rubber substrates is demonstrated. The coplanar gate configuration of the graphene transistor enables a simplified procedure. The resulting devices exhibit excellent device performance, including a high transparency of ca. 80% in the visible range, a low operating voltage less than 2 V, a high pressure sensitivity of 0.12 kPa(-1) , and excellent mechanical durability over 2500 cycles.

  2. Non-coplanar automatic beam orientation selection in cranial IMRT: a practical methodology

    Energy Technology Data Exchange (ETDEWEB)

    Llacer, Jorge [EC Engineering Consultants LLC, 130 Forest Hill Drive, Los Gatos, CA 95032 (United States); Li Sicong [Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE 68198 (United States); Agazaryan, Nzhde; Solberg, Timothy D [Department of Radiation Oncology, University of California, Los Angeles, CA 90095 (United States); Promberger, Claus [BrainLAB AG, Kapellenstrasse 12, 85622 Feldkirchen (Germany)], E-mail: escalivat@jllacer.com, E-mail: sl1@unmc.edu, E-mail: NAgazaryan@mednet.ucla.edu, E-mail: claus.promberger@brainlab.com, E-mail: Timothy.Solberg@utsouthwestern.edu

    2009-03-07

    This paper proposes a method for automatic selection of beam orientations in non-coplanar cranial IMRT. Methods of computer vision, beam's eye view techniques and neural networks are used to define a new geometry-based methodology that leads to treatment plans for cranial lesions that are comparable in quality to those generated by experienced radiation physicists. The automatic beam selection (ABS) process can be carried out in clinically useful computation times, in 1 min or less for most cases. In the process of describing the ABS process, it is shown that the cranial beam orientation optimization problem is mathematically ill posed, with the expectation that a large number of solutions will lead to similar results. Nevertheless, there are better and worse solutions and we show that the proposed ABS process, by its design, has to lead to one of the better ones. We have carried out extensive tests with 14 patients with beam selection tasks ranging from the rather simple to quite complex. The ABS process has always yielded optimizations with results that are considered good for clinic use. Seven-beam coplanar optimizations for some of the patients have also been investigated. Comparisons with non-coplanar optimizations indicate in which cases the simpler coplanar plans can be used to advantage. Parameters used in the comparisons are dose-volume histograms, minimum and maximum PTV doses, equivalent uniform doses for the PTV and OARs, and treatment volume, conformity and normal tissue indices. It is felt that the current ABS methodology is ready for extensive clinical tests.

  3. Vision Servo Motion Control and Error Analysis of a Coplanar XXY Stage for Image Alignment Motion

    Directory of Open Access Journals (Sweden)

    Hau-Wei Lee

    2013-01-01

    Full Text Available In recent years, as there is demand for smart mobile phones with touch panels, the alignment/compensation system of alignment stage with vision servo control has also increased. Due to the fact that the traditional stacked-type XYθ stage has cumulative errors of assembly and it is heavy, it has been gradually replaced by the coplanar stage characterized by three actuators on the same plane with three degrees of freedom. The simplest image alignment mode uses two cameras as the equipments for feedback control, and the work piece is placed on the working stage. The work piece is usually engraved/marked. After the cameras capture images and when the position of the mark in the camera is obtained by image processing, the mark can be moved to the designated position in the camera by moving the stage and using alignment algorithm. This study used a coplanar XXY stage with 1 μm positioning resolution. Due to the fact that the resolution of the camera is about 3.75 μm per pixel, thus a subpixel technology is used, and the linear and angular alignment repeatability of the alignment system can achieve 1 μm and 5 arcsec, respectively. The visual servo motion control for alignment motion is completed within 1 second using the coplanar XXY stage.

  4. Buoyancy effects in vertical rectangular duct with coplanar magnetic field and single sided heat load

    Energy Technology Data Exchange (ETDEWEB)

    Kirillov, I.R. [NIIEFA – JSC “D.V. Efremov Institute of Electrophysical Apparatus”, St. Petersburg, 196641 (Russian Federation); Obukhov, D.M., E-mail: obukhov@sintez.niiefa.spb.su [NIIEFA – JSC “D.V. Efremov Institute of Electrophysical Apparatus”, St. Petersburg, 196641 (Russian Federation); Genin, L.G. [MPEI – National Research University “Moscow Power Engineering Institute”, 14 Krasnokazarmennaya str., Moscow (Russian Federation); Sviridov, V.G.; Razuvanov, N.G.; Batenin, V.M.; Belyaev, I.A. [JIHT – Joint Institute of High Temperatures of the Russian Academy of Science, 13/19, Igorskaya str., Moscow (Russian Federation); Poddubnyi, I.I. [MPEI – National Research University “Moscow Power Engineering Institute”, 14 Krasnokazarmennaya str., Moscow (Russian Federation); Pyatnitskaya, N.Yu. [JIHT – Joint Institute of High Temperatures of the Russian Academy of Science, 13/19, Igorskaya str., Moscow (Russian Federation)

    2016-03-15

    Highlights: • Heat transfer in vertical duct mercury flow in coplanar magnetic field is studied. • Mean velocity, temperature and temperature pulsations are measured. • Buoyancy influence on heat transfer is found. - Abstract: This article investigates an effect which was found out in downward flow of liquid metal (LM) in vertical rectangular duct in coplanar magnetic field (MF). The experiments have been performed on facility which located in JIHT. This facility is magneto hydrodynamic (MHD) mercury close-loop. The temperature field measurements have been performed at one side heating conditions in coplanar magnetic field. The averaged temperature fields, wall temperature distributions and statistical characteristics of temperature fluctuation have been obtained. The strong influence of counter thermo-gravitational convection (TGC) on average and fluctuation parameters has been observed. The influence of TGC in magnetic field leads to developing of temperature low-frequency fluctuations with high magnitude. The temperature fluctuation amplitude in a wide range of operating conditions is higher than turbulence level.

  5. PLATFORM DEFORMATION PHASE CORRECTION FOR THE AMiBA-13 COPLANAR INTERFEROMETER

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Yu-Wei; Lin, Kai-Yang; Huang, Yau-De; Ho, Paul T. P.; Chen, Ming-Tang; Locutus Huang, Chih-Wei; Koch, Patrick M.; Nishioka, Hiroaki; Umetsu, Keiichi; Han, Chih-Chiang; Li, Chao-Te; Martin-Cocher, Pierre; Oshiro, Peter [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Proty Wu, Jiun-Huei; Cheng, Tai-An; Fu, Szu-Yuan; Wang, Fu-Cheng [Department of Physics, Institute of Astrophysics, and Center for Theoretical Sciences, National Taiwan University, Taipei 10617, Taiwan (China); Liu, Guo-Chin [Department of Physics, Tamkang University, 251-37 Tamsui, New Taipei City, Taiwan (China); Molnar, Sandor M. [Leung Center for Cosmology and Particle Astrophysics, National Taiwan University, Taipei 10617, Taiwan (China); Chang, Yu-Yen, E-mail: ywliao@asiaa.sinica.edu.tw, E-mail: jhpw@phys.ntu.edu.tw [Max-Planck-Institut fuer Astronomie, Koenigstuhl 17, D-69117 Heidelberg (Germany)

    2013-05-20

    We present a new way to solve the platform deformation problem of coplanar interferometers. The platform of a coplanar interferometer can be deformed due to driving forces and gravity. A deformed platform will induce extra components into the geometric delay of each baseline and change the phases of observed visibilities. The reconstructed images will also be diluted due to the errors of the phases. The platform deformations of The Yuan-Tseh Lee Array for Microwave Background Anisotropy (AMiBA) were modeled based on photogrammetry data with about 20 mount pointing positions. We then used the differential optical pointing error between two optical telescopes to fit the model parameters in the entire horizontal coordinate space. With the platform deformation model, we can predict the errors of the geometric phase delays due to platform deformation with a given azimuth and elevation of the targets and calibrators. After correcting the phases of the radio point sources in the AMiBA interferometric data, we recover 50%-70% flux loss due to phase errors. This allows us to restore more than 90% of a source flux. The method outlined in this work is not only applicable to the correction of deformation for other coplanar telescopes but also to single-dish telescopes with deformation problems. This work also forms the basis of the upcoming science results of AMiBA-13.

  6. Development of Gas Ionization Chambers with Coplanar Electrodes for Alpha-ray Spectrometry

    Science.gov (United States)

    Iwasaki, Kenta; Tanaka, Naomichi; Murakami, Kohei; Kusano, Hiroki; Shibamura, Eido; Hasebe, Nobuyuki; Miyajima, Mitsuhiro

    A large-area alpha-ray spectrometer is required to measure the low level alpha emitters in environmental samples, which may be distributed in the vicinity of nuclear power plants. A gas ionization chamber with a coplanar electrode has attractive features such as with mechanical ruggedness, easy handling, easy fabrication of large electrode, and relatively well-known performance. We have investigated the performance of a gas ionization chamber with a coplanar electrode for alpha-ray spectrometry, particularly in the energy resolution. The present experiment shows that the energy resolution in the full width at half maximum (FWHM) is 129 keV (= 2.7%) for alpha-rays from Np with an energy of 4.78 MeV, 120 keV (= 2.2%) for those with 5.49 MeV from Am, and 109 keV (= 1.9%) for those with 5.81 MeV from Cm. It is found that the energy resolution obtained at the present experiment is dominated in the electronic noise caused by the large capacitance existed between the collecting anode (CA) and non-collecting anode (NCA) in the coplanar electrode.

  7. Coplanar UHF RFID tag antenna with U-shaped inductively coupled feed for metallic applications.

    Science.gov (United States)

    Salman, Karrar Naji; Ismail, Alyani; Raja Abdullah, Raja Syamsul Azmir; Saeedi, Tale

    2017-01-01

    In this paper, we present a novel compact, coplanar, tag antenna design for metallic objects. Electrically small antenna has designed for a UHF RFID (860-960 MHz) based on a proximity-coupled feed through. Furthermore, two symmetrical Via-loaded coplanar grounds fed by a U-shaped inductively coupled feed through an embedded transmission line. This configuration results in an antenna with dimensions of 31 × 19.5 × 3.065 mm3 at 915 MHz, and the total gain for the antenna is 0.12 dBi. The Via-loaded coplanar and U-shaped inductively coupled feeds allow the antenna to provide flexible tuning in terms of antenna impedance. In addition, a figure of merit is applied for the proposed tag antenna, and the results are presented. The read range is measured to be 4.2 m, which is very close to simulated values. This antenna measurement shows very good agreement with simulations.

  8. Characterization of coplanar grid CZT detectors with highly collimated x-ray beam

    Science.gov (United States)

    Carini, Gabriella A.; Bolotnikov, Aleksey E.; Camarda, Giuseppe S.; Wright, Gomez W.; De Geronimo, Gianluigi; Siddons, D. P.; James, Ralph B.

    2004-10-01

    CdZnTe detectors demonstrated great potentials for detection of gamma radiation. However, energy resolution of CdZnTe detectors is significantly affected by uncollected holes which have low mobility and short lifetime. To overcome this deleterious effects upon energy resolution special detector designs have to be implemented. The most practical of them are the small pixel effect device, the co-planar grid device, and the virtual Frisch-grid device. We routinely use a highly collimated high-intensity X-ray beams provided by National Synchrotron Light Source (NSLS) facility at Brookhaven National Laboratory to study of CdZnTe material and performances of the different types of devices on the micron-scale. This powerful tool allows us to evaluate electronic properties of the material, device performance, uniformity of the detector responses, effects related to the device's contact pattern and electric field distribution, etc. In particular, in this paper we present new results obtained from the performance studies of 15 x 15 x 7.5 mm3 coplanar-grid devices coupled to readout ASIC. We observed the effect of the strip contacts comprising the grids on the energy resolution of the coplanar-grid device.

  9. Comparison of coplanar and noncoplanar intensity-modulated radiation therapy and helical tomotherapy for hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    Tai Hung-Chi

    2010-05-01

    Full Text Available Abstract Background To compare the differences in dose-volume data among coplanar intensity modulated radiotherapy (IMRT, noncoplanar IMRT, and helical tomotherapy (HT among patients with hepatocellular carcinoma (HCC and portal vein thrombosis (PVT. Methods Nine patients with unresectable HCC and PVT underwent step and shoot coplanar IMRT with intent to deliver 46 - 54 Gy to the tumor and portal vein. The volume of liver received 30Gy was set to keep less than 30% of whole normal liver (V30 Results HT provided better uniformity for the planning-target volume dose coverage than both IMRT techniques. The noncoplanar IMRT technique reduces the V10 to normal liver with a statistically significant level as compared to HT. The constraints for the liver in the V30 for coplanar IMRT vs. noncoplanar IMRT vs. HT could be reconsidered as 21% vs. 17% vs. 17%, respectively. When delivering 50 Gy and 60-66 Gy to the tumor bed, the constraints of mean dose to the normal liver could be less than 20 Gy and 25 Gy, respectively. Conclusion Noncoplanar IMRT and HT are potential techniques of radiation therapy for HCC patients with PVT. Constraints for the liver in IMRT and HT could be stricter than for 3DCRT.

  10. A study on the microwave responses of YBCO and TBCCO thin films by coplanar resonator technique

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    YBa2CuaO7(YBCO) thin films have been prepped by thermal coevaporation on LaAlO3 (LAO) substrates, and Tl2Ba2CaCu2O8(TBCCO) thin films are synthesized by magnetron sputtering method on LAO substrates. The transition temperature Tc is 90 K for YBCO/LAO and 104K for TBCCO/LAO. Microwave responses of the films are studied systematically by coplanar resonator technique. Energu gaps of the films obtained are △0 = 1.04kBTc for YBCO films and △0 = 0.84kBTc for TBCCO films by analysing the temperature dependence of resonant frequencies of coplanar resonator. Penetration depth at 0K λ0 = 198 nm for YBCO films and λ0 = 200 nm for TBCCO films could also be obtained by using the weak coupling theory and two fluid theory. Results of penetration depth and energy gap confirm the weak coupling properties of the films. In addition, microwave surface resistances Rs of YBCO/LAO and TBCCO/LAO are also investigated by analysing the quality factor and insert loss of the coplanar resonator. Surface resistance of TBCCO/LAO is less than that of YBCO/LAO, so that TBCCO/LAO films may have more potential applications.

  11. Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like coplanar polychlorinated biphenyls in mackerel obtained from the Japanese market, 1999-2003.

    Science.gov (United States)

    Nakatani, Tadashi; Yamano, Testuo

    2017-09-01

    This study analysed the concentrations and toxic-equivalent (TEQ) levels of dioxin congeners in mackerel commercially available in Japan in early 2000s. The content of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like coplanar polychlorinated biphenyls (DL-PCBs) was determined in 17 mackerel samples from different areas. TEQ levels in mackerel muscle were 0.78 pg TEQ g(-)(1) wet weight (wt) on average (range = 0.21-2.26 pg TEQ g(-)(1) wet wt) for PCDD/Fs (PCDDs plus PCDFs), 2.81 pg TEQ g(-)(1) wet wt on average (range = 1.02-8.5 pg TEQ g(-)(1) wet wt) for DL-PCBs, and 3.59 pg TEQ g(-)(1) wet wt on average (range = 1.24-10.8 pg g(-)(1) wet wt) for dioxins (PCDD/Fs plus DL-PCBs). The results revealed somewhat higher TEQ levels for dioxins compared with the other data for fish and shellfish in the Japanese market. TEQ levels were well correlated with mackerel body weight; the main contributors were tetra- and penta-CDD/Fs, some hexa-CDD/Fs, and all 12 DL-PCBs, which are known to have high bioaccumulation potential. In particular, PCB 126 was mostly responsible for the observed correlation of DL-PCB and dioxins-TEQ levels with mackerel body weight. The average daily intake of dioxins in terms of TEQ through mackerel consumption was estimated to be 4.81 pg TEQ/person/day, accounting for 7% of the total intake of dioxins-TEQ through fish and shellfish in Japan.

  12. Brown Norway chromosome 1 congenic reduces symptoms of renal disease in fatty Zucker rats.

    Science.gov (United States)

    Warden, Craig H; Slupsky, Carolyn; Griffey, Stephen M; Bettaieb, Ahmed; Min, Esther; Le, Anh; Fisler, Janis S; Hansen, Susan; Haj, Fawaz; Stern, Judith S

    2014-01-01

    We previously reported that a congenic rat with Brown Norway (BN) alleles on chromosome 1 reduces renal disease of 15-week old fatty Zucker rats (ZUC). Development of renal disease in fatty BN congenic and fatty ZUC rats from 9 through 28 weeks is now examined. Analysis of urine metabolites by (1)H nuclear magnetic resonance (NMR) spectroscopy revealed a significantly increased urinary loss of glucose, myo-inositol, urea, creatine, and valine in ZUC. Food intake was lower in the BN congenic rats at weeks 9-24, but they weighed significantly more at 28 weeks compared with the ZUC group. Fasting glucose was significantly higher in ZUC than congenic and adiponectin levels were significantly lower in ZUC, but there was no significant genotype effect on Insulin levels. Glucose tolerance tests exhibited no significant differences between ZUC and congenic when values were normalized to basal glucose levels. Quantitative PCR on livers revealed evidence for higher gluconeogenesis in congenics than ZUC at 9 weeks. Plasma urea nitrogen and creatinine were more than 2-fold higher in 28-week ZUC. Twelve urine protein markers of glomerular, proximal and distal tubule disease were assayed at three ages. Several proteins that indicate glomerular and proximal tubular disease increased with age in both congenic and ZUC. Epidermal growth factor (EGF) level, a marker whose levels decrease with distal tubule disease, was significantly higher in congenics. Quantitative histology of 28 week old animals revealed the most significant genotype effect was for tubular dilation and intratubular protein. The congenic donor region is protective of kidney disease, and effects on Type 2 diabetes are likely limited to fasting glucose and adiponectin. The loss of urea together with a small increase of food intake in ZUC support the hypothesis that nitrogen balance is altered in ZUC from an early age.

  13. A modeling approach to compare ΣPCB concentrations between congener-specific analyses

    Science.gov (United States)

    Gibson, Polly P.; Mills, Marc A.; Kraus, Johanna M.; Walters, David M.

    2017-01-01

    Changes in analytical methods over time pose problems for assessing long-term trends in environmental contamination by polychlorinated biphenyls (PCBs). Congener-specific analyses vary widely in the number and identity of the 209 distinct PCB chemical configurations (congeners) that are quantified, leading to inconsistencies among summed PCB concentrations (ΣPCB) reported by different studies. Here we present a modeling approach using linear regression to compare ΣPCB concentrations derived from different congener-specific analyses measuring different co-eluting groups. The approach can be used to develop a specific conversion model between any two sets of congener-specific analytical data from similar samples (similar matrix and geographic origin). We demonstrate the method by developing a conversion model for an example data set that includes data from two different analytical methods, a low resolution method quantifying 119 congeners and a high resolution method quantifying all 209 congeners. We used the model to show that the 119-congener set captured most (93%) of the total PCB concentration (i.e., Σ209PCB) in sediment and biological samples. ΣPCB concentrations estimated using the model closely matched measured values (mean relative percent difference = 9.6). General applications of the modeling approach include (a) generating comparable ΣPCB concentrations for samples that were analyzed for different congener sets; and (b) estimating the proportional contribution of different congener sets to ΣPCB. This approach may be especially valuable for enabling comparison of long-term remediation monitoring results even as analytical methods change over time. 

  14. Adenosine Amine Congener as a Cochlear Rescue Agent

    Directory of Open Access Journals (Sweden)

    Srdjan M. Vlajkovic

    2014-01-01

    Full Text Available We have previously shown that adenosine amine congener (ADAC, a selective A1 adenosine receptor agonist, can ameliorate noise- and cisplatin-induced cochlear injury. Here we demonstrate the dose-dependent rescue effects of ADAC on noise-induced cochlear injury in a rat model and establish the time window for treatment. Methods. ADAC (25–300 μg/kg was administered intraperitoneally to Wistar rats (8–10 weeks old at intervals (6–72 hours after exposure to traumatic noise (8–16 kHz, 110 dB sound pressure level, 2 hours. Hearing sensitivity was assessed using auditory brainstem responses (ABR before and 12 days after noise exposure. Pharmacokinetic studies investigated ADAC concentrations in plasma after systemic (intravenous administration. Results. ADAC was most effective in the first 24 hours after noise exposure at doses >50 μg/kg, providing up to 21 dB protection (averaged across 8–28 kHz. Pharmacokinetic studies demonstrated a short (5 min half-life of ADAC in plasma after intravenous administration without detection of degradation products. Conclusion. Our data show that ADAC mitigates noise-induced hearing loss in a dose- and time-dependent manner, but further studies are required to establish its translation as a clinical otological treatment.

  15. Contrasting patterns of transgenerational plasticity in ecologically distinct congeners.

    Science.gov (United States)

    Sultan, Sonia E; Barton, Kasey; Wilczek, Amity M

    2009-07-01

    Stressful parental environments can influence offspring size and development either adaptively or maladaptively, yet little is known about species' differences in this complex aspect of phenotypic plasticity. We performed a reciprocal split-brood experiment to compare transgenerational plasticity in response to drought stress in two closely related annual plant species. We raised inbred replicate parent plants of eight genotypes per species in dry vs. moist soil to generate offspring of each genetic line that differed only in parental environment, then monitored seedling development in both dry and moist conditions. Individuals of the two species expressed contrasting patterns of transgenerational plasticity for traits important to seedling drought tolerance. In Polygonum persicaria, a weedy generalist found in moist, dry, and variably dry sites, drought-stressed plants produced offspring with longer and more rapidly extending root systems and greater biomass when growing in dry soil. In contrast, in P. hydropiper, a non-weedy congener restricted to moist habitats, the offspring of drought-stressed parents had reduced root system development and seedling biomass in dry soil. In P. persicaria, transgenerational and immediate adaptive plasticity combined to produce drought-adapted seedling phenotypes. These results make clear that characteristic patterns of transgenerational plasticity can contribute to ecological diversity among species.

  16. Minimum fuel coplanar aeroassisted orbital transfer using collocation and nonlinear programming

    Science.gov (United States)

    Shi, Yun Yuan; Young, D. H.

    1991-01-01

    The fuel optimal control problem arising in coplanar orbital transfer employing aeroassisted technology is addressed. The mission involves the transfer from high energy orbit (HEO) to low energy orbit (LEO) without plane change. The basic approach here is to employ a combination of propulsive maneuvers in space and aerodynamic maneuvers in the atmosphere. The basic sequence of events for the coplanar aeroassisted HEO to LEO orbit transfer consists of three phases. In the first phase, the transfer begins with a deorbit impulse at HEO which injects the vehicle into a elliptic transfer orbit with perigee inside the atmosphere. In the second phase, the vehicle is optimally controlled by lift and drag modulation to satisfy heating constraints and to exit the atmosphere with the desired flight path angle and velocity so that the apogee of the exit orbit is the altitude of the desired LEO. Finally, the second impulse is required to circularize the orbit at LEO. The performance index is maximum final mass. Simulation results show that the coplanar aerocapture is quite different from the case where orbital plane changes are made inside the atmosphere. In the latter case, the vehicle has to penetrate deeper into the atmosphere to perform the desired orbital plane change. For the coplanar case, the vehicle needs only to penetrate the atmosphere deep enough to reduce the exit velocity so the vehicle can be captured at the desired LEO. The peak heating rates are lower and the entry corridor is wider. From the thermal protection point of view, the coplanar transfer may be desirable. Parametric studies also show the maximum peak heating rates and the entry corridor width are functions of maximum lift coefficient. The problem is solved using a direct optimization technique which uses piecewise polynomial representation for the states and controls and collocation to represent the differential equations. This converts the optimal control problem into a nonlinear programming problem

  17. Modular methodology for determination of polychlorinated biphenyls in soil as Aroclors and individual congeners

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, J.R.; Grange, A.H.; Herron, N.R. [Lockheed Environmental Systems & Technologies Co., Las Vegas, NV (United States)] [and others

    1996-07-01

    A comprehensive screening and confirmatory method was developed for monitoring polychlorinated biphenyls (PCBs), both as Aroclors and as individual congeners. This approach incorporates extraction, extract cleanup, and analysis modules designed to match cost, time, and data quality requirements. Soxhlet, sonication, supercritical fluid, and accelerated solvent extractions were evaluated. Carbon chromatographic cleanup procedures were used for separation of congeners on the basis of ortho substitutions, which permitted calculation of toxicity equivalents. Individual congener determinations, congener total histograms, and peak comparison techniques for Aroclor identification were elaborated by using high and low resolution mass spectrometric data. A screening procedure based on immunoassay using the Ohmicron PCB RaPID Assay{trademark} kit gave results comparable to those obtained by gas chromatography with electron capture detection in the range 0.40-230 ppm, when the appropriate Aroclor calibrator was used. 21 refs., 3 figs., 4 tabs.

  18. The Identification of Congeners and Aliens by Drosophila Larvae.

    Directory of Open Access Journals (Sweden)

    Francisco Del Pino

    Full Text Available We investigated the role of Drosophila larva olfactory system in identification of congeners and aliens. We discuss the importance of these activities in larva navigation across substrates, and the implications for allocation of space and food among species of similar ecologies. Wild type larvae of cosmopolitan D. melanogaster and endemic D. pavani, which cohabit the same breeding sites, used species-specific volatiles to identify conspecifics and aliens moving toward larvae of their species. D. gaucha larvae, a sibling species of D. pavani that is ecologically isolated from D. melanogaster, did not respond to melanogaster odor cues. Similar to D. pavani larvae, the navigation of pavani female x gaucha male hybrids was influenced by conspecific and alien odors, whereas gaucha female x pavani male hybrid larvae exhibited behavior similar to the D. gaucha parent. The two sibling species exhibited substantial evolutionary divergence in processing the odor inputs necessary to identify conspecifics. Orco (Or83b mutant larvae of D. melanogaster, which exhibit a loss of sense of smell, did not distinguish conspecific from alien larvae, instead moving across the substrate. Syn97CS and rut larvae of D. melanogaster, which are unable to learn but can smell, moved across the substrate as well. The Orco (Or83b, Syn97CS and rut loci are necessary to orient navigation by D. melanogaster larvae. Individuals of the Trana strain of D. melanogaster did not respond to conspecific and alien larval volatiles and therefore navigated randomly across the substrate. By contrast, larvae of the Til-Til strain used larval volatiles to orient their movement. Natural populations of D. melanogaster may exhibit differences in identification of conspecific and alien larvae. Larval locomotion was not affected by the volatiles.

  19. The Identification of Congeners and Aliens by Drosophila Larvae

    Science.gov (United States)

    Del Pino, Francisco; Jara, Claudia; Pino, Luis; Medina-Muñoz, María Cristina; Alvarez, Eduardo; Godoy-Herrera, Raúl

    2015-01-01

    We investigated the role of Drosophila larva olfactory system in identification of congeners and aliens. We discuss the importance of these activities in larva navigation across substrates, and the implications for allocation of space and food among species of similar ecologies. Wild type larvae of cosmopolitan D. melanogaster and endemic D. pavani, which cohabit the same breeding sites, used species-specific volatiles to identify conspecifics and aliens moving toward larvae of their species. D. gaucha larvae, a sibling species of D. pavani that is ecologically isolated from D. melanogaster, did not respond to melanogaster odor cues. Similar to D. pavani larvae, the navigation of pavani female x gaucha male hybrids was influenced by conspecific and alien odors, whereas gaucha female x pavani male hybrid larvae exhibited behavior similar to the D. gaucha parent. The two sibling species exhibited substantial evolutionary divergence in processing the odor inputs necessary to identify conspecifics. Orco (Or83b) mutant larvae of D. melanogaster, which exhibit a loss of sense of smell, did not distinguish conspecific from alien larvae, instead moving across the substrate. Syn97CS and rut larvae of D. melanogaster, which are unable to learn but can smell, moved across the substrate as well. The Orco (Or83b), Syn97CS and rut loci are necessary to orient navigation by D. melanogaster larvae. Individuals of the Trana strain of D. melanogaster did not respond to conspecific and alien larval volatiles and therefore navigated randomly across the substrate. By contrast, larvae of the Til-Til strain used larval volatiles to orient their movement. Natural populations of D. melanogaster may exhibit differences in identification of conspecific and alien larvae. Larval locomotion was not affected by the volatiles. PMID:26313007

  20. Use of herbarium data to evaluate weediness in five congeners.

    Science.gov (United States)

    Hanan-A, Ana M; Vibrans, Heike; Cacho, N Ivalú; Villaseñor, José L; Ortiz, Enrique; Gómez-G, Vinicio A

    2015-01-01

    It is often desirable to quantify a plant's relative weediness or synanthropy, that is, the degree to which a species associates with human-caused disturbance, in order to study and understand the biology, ecology and evolution of weeds and invasive plants. Herbarium specimens are among the most accessible and verifiable sources of data on distribution and habitat. However, the habitat distribution of species may not be reflected accurately by herbarium specimen data, due to well-known biases in plant collection. Here, we assess how well herbarium specimens reflect species' weediness, when compared with direct field surveys. We used five species of Melampodium (Asteraceae) and classified their degree of weediness with a modification of Nuorteva's synanthropy index, based on herbarium specimens. We then modelled the distribution of our focal species in Mexico using MaxEnt and identified a polygon of ∼3000 km(2) in the state of Nayarit, Mexico, where there was a high probability of finding all five species. Systematic field searches in the target area documented all visible populations of four species along major and minor roads. Then we, again, classified their degree of weediness with the synanthropy index, based now on field data, and compared. We found that herbarium data were an accurate predictor of a species' weediness relative to its congeners despite the well-documented skew of herbarium data towards natural areas, which our data reflected as well. So, herbarium data can be used to classify species' weediness relative to each other, but not in absolute terms, if the specimens were correctly identified and none of the species were subject to particular collection bias. This study is the first attempt to compare herbarium and field data on this subject and may be relevant for other types of investigations based on herbarium data. Our work also highlights the usefulness of distribution models based on herbarium specimens.

  1. A GCMSD/ECD method for the simultaneous determination of toxaphene and toxaphene congeners.

    Science.gov (United States)

    Maceachen, D Cameron; Cocks, Nigel

    2002-10-01

    The methodology presented combines mass selective detection technology for routine automated total toxaphene determinations with electron capture detection confirmation of congener results. Total toxaphene values were calculated using a custom developed series of data analysis macroinstructions (macros) that eliminate potential interferences and collate peak areas. These macros create multi-level calibration tables with results automatically corrected for surrogate and performance standards. It is possible to produce congener data that provides results from both detectors in one report from a single injection.

  2. Human liver morphine UDP-glucuronyl transferase enantioselectivity and inhibition by opioid congeners and oxazepam.

    OpenAIRE

    Wahlström, A; Pacifici, G. M.; Lindström, B; Hammar, L.; Rane, A.

    1988-01-01

    1. Morphine uridine diphosphate glucuronyl transferase (UDP-GT) was studied in human liver microsomes. The (-)- and (+)-morphine enantiomers were used as substrates and inhibitors, such as oxazepam and various opioid congeners were employed to characterize the different glucuronidation pathways. The kinetics of the oxazepam inhibition were studied in the rat liver. 2. The overall glucuronidation of (+)-morphine was higher than that of (-)-morphine. The morphine congeners tested, potently inhi...

  3. Organic anion transporting polypeptides in the hepatic uptake of PBDE congeners in mice

    Energy Technology Data Exchange (ETDEWEB)

    Pacyniak, Erik [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Hagenbuch, Bruno [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); The University of Kansas Cancer Center, Kansas City, KS (United States); Klaassen, Curtis D. [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Lehman-McKeeman, Lois [Bristol Myers Squibb Co., Princeton, NJ (United States); Guo, Grace L., E-mail: lguo@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States)

    2011-11-15

    BDE47, BDE99 and BDE153 are the predominant polybrominated diphenyl ether (PBDE) congeners detected in humans and can induce drug metabolizing enzymes in the liver. We have previously demonstrated that several human liver organic anion transporting polypeptides (humans: OATPs; rodents: Oatps) can transport PBDE congeners. Mice are commonly used to study the toxicity of chemicals like the PBDE congeners. However, the mechanism of the hepatic PBDE uptake in mice is not known. Therefore, the purpose of the current study was to test the hypothesis that BDE47, BDE99, and BDE153 are substrates of mouse hepatic Oatps (Oatp1a1, Oatp1a4, Oatp1b2, and Oatp2b1). We used Human Embryonic Kidney 293 (HEK293) cells transiently expressing individual Oatps and quantified the uptake of BDE47, BDE99, and BDE153. Oatp1a4, Oatp1b2, and Oatp2b1 transported all three PBDE congeners, whereas Oatp1a1 did transport none. Kinetic studies demonstrated that Oatp1a4 and Oatp1b2 transported BDE47 with the greatest affinity, followed by BDE99 and BDE153. In contrast, Oatp2b1 transported all three PBDE congeners with similar affinities. The importance of hepatic Oatps for the liver accumulation of BDE47 was confirmed using Oatp1a4-, and Oatp1b2-null mice. -- Highlights: Black-Right-Pointing-Pointer PBDE congeners are substrates of OATPs expressed in human hepatocytes. Black-Right-Pointing-Pointer Mice are commonly used to study the toxicity of chemicals like the PBDE congeners. Black-Right-Pointing-Pointer Oatp1a4, Oatp1b2, and Oatp2b1 transported all three PBDE congeners in vitro. Black-Right-Pointing-Pointer In vivo Oatp1a4 plays a minor and Oatp1b2 a major role in BDE47 liver accumulation.

  4. Production of WTC.ZI-zi rat congenic strain and its pathological and genetic analyses.

    Science.gov (United States)

    Kuramoto, T; Yamasaki, K; Kondo, A; Nakajima, K; Yamada, M; Serikawa, T

    1998-04-01

    A new rat congenic strain, WTC.ZI-zi, was produced after eleven generations of backcrossing between ZI strain as a donor strain and WTC strain as an inbred partner. WTC.ZI-zi/zi homozygous rats generally exhibit more conspicuous body tremor and much earlier occurrence of flaccid paresis than the original ZI strain. The average life span of the congenic strain is approximately nine months, which is also much shorter than that of the original ZI strain. Pathological analysis of the central nervous system of the congenic strain revealed more aggravated vacuolation and hypomyelination than in the original ZI strain. Establishment of the genetic profile with microsatellite markers showed that the congenic strain was genetically almost identical to the WTC strain except for a small chromosome segment bearing the zitter gene. Analysis of markers in this region implied that the length of the donor segment was approximately 13.4 centimorgans which corresponded to 0.65% of the total genome. Thus, these results suggested that expressional alterations of zitter gene were due to replacement of the genetic background from the original ZI strain to the WTC strain. Furthermore, the WTC.ZI-zi congenic strain could provide a refined tool for the analysis of zitter mutation, because the congenic strain has a strict control strain, WTC, and the length of the donor chromosome is genetically defined.

  5. Net trophic transfer efficiencies of polychlorinated biphenyl congeners to lake whitefish (Coregonus clupeaformis) from their food

    Science.gov (United States)

    Madenjian, C.P.; O'Connor, D.V.; Rediske, R.R.; O'Keefe, J. P.; Pothoven, S.A.

    2008-01-01

    Lake whitefish (Coregonus clupeaformis) were fed rainbow smelt (Osmerus mordax) in four laboratory tanks over a 133-d experiment. At the start of the experiment, 10 to 14 of the fish in each tank were sacrificed, and the concentrations of 40 polychlorinated biphenyl (PCB) congeners within these fish were determined. Polychlorinated biphenyl congener concentrations were also determined in the 15 lake whitefish remaining in each of the four tanks at the end of the experiment as well as in the rainbow smelt fed to the lake whitefish. Each lake whitefish was weighed at the start and the end of the experiment, and the amount of food eaten by the lake whitefish during the experiment was tracked. Using these measurements, net trophic transfer efficiency (??) from the rainbow smelt to the lake whitefish in each of the four tanks was calculated for each of the 40 PCB congeners. Results showed that ?? decreased exponentially as log KOW for the congeners increased from 6 to 8. Further, ?? averaged 0.70 for the tetrachloro congeners but averaged only 0.45 for the higher chlorinated congeners. ?? 2008 SETAC.

  6. Coplanar VMAT vs. noncoplanar VMAT in the treatment of sinonasal cancer.

    Science.gov (United States)

    Zhong-Hua, Ning; Jing-Ting, Jiang; Xiao-Dong, Li; Jin-Ming, Mu; Jun-Chong, Mo; Jian-Xue, Jin; Ming, Gao; Qi-Lin, Li; Wen-Dong, Gu; Lu-Jun, Chen; Hong-Lei, Pei

    2015-01-01

    Previous studies showed that noncoplanar intensity-modulated radiotherapy (NC-IMRT) for sinonasal cancer is superior to coplanar intensity-modulated radiotherapy (IMRT). Volumetric-modulated arc therapy (VMAT) is a newly introduced treatment modality, and the performance of noncoplanar VMAT for sinonasal cancer has not been well described to date. To compare the dosimetry difference of noncoplanar VMAT (NC-VMAT), coplanar VMAT (co-VMAT), and NC-IMRT for sinonasal cancer. Ten postoperative patients with sinonasal cancer were randomly selected for planning with NC-VMAT, co-VMAT, and NC-IMRT. Two planning target volumes (PTVs) were contoured representing high-risk and low-risk regions set to receive a median absorbed dose (D50%) of 68 Gy and 59 Gy, respectively. The homogeneity index (HI), conformity index (CI), dose-volume histograms (DVHs), and delivery efficiency were all evaluated. Both NC-VMAT and co-VMAT showed superior dose homogeneity and conformity in PTVs compared with NC-IMRT. There was no significant difference between NC-VMAT and co-VMAT in PTV coverage. Both VMAT plans provided a better protection for organs at risk (OARs) than NC-IMRT plans, and NC-VMAT showed a small improvement over co-VMAT in sparing of OARs. For peripheral doses, the doses to breast, thyroid, and larynx in the NC-IMRT plans were significantly higher than those in both VMAT plans. Compared to NC-VMAT, co-VMAT significantly reduced peripheral doses. NC-VMAT and co-VMAT reduced the average delivery time by 63.2 and 64.2%, respectively, in comparison with NC-IMRT. No differences in delivery efficiency were observed between the two VMAT plans. Compared to NC-VMAT, co-VMAT showed similar PTV coverage and comparable OAR sparing but significantly reduced peripheral doses and positioning uncertainty. We propose to give priority to coplanar VMAT in the treatment of sinonasal cancer.

  7. Finite Ground Coplanar (FGC) Waveguide: Characteristics and Advantages Evaluated for Radiofrequency and Wireless Communication Circuits

    Science.gov (United States)

    Ponchak, George E.

    1999-01-01

    Researchers in NASA Lewis Research Center s Electron Device Technology Branch are developing transmission lines for radiofrequency and wireless circuits that are more efficient, smaller, and make lower cost circuits possible. Traditionally, radiofrequency and wireless circuits have employed a microstrip or coplanar waveguide to interconnect the various electrical elements that comprise a circuit. Although a coplanar waveguide (CPW) is widely viewed as better than a microstrip for most applications, it too has problems. To solve these problems, NASA Lewis and the University of Michigan developed a new version of a coplanar waveguide with electrically narrow ground planes. Through extensive numerical modeling and experimental measurements, we have characterized the propagation constant of the FGC waveguide, the lumped and distributed circuit elements integrated in the FGC waveguide, and the coupling between parallel transmission lines. Although the attenuation per unit length is higher for the FGC waveguide because of higher conductor loss, the attenuation is comparable when the ground plane width is twice the center conductor width as shown in the following graph. An upper limit to the line width is derived from observations that when the total line width is greater than ld/2, spurious resonances due to the parallel plate waveguide mode are established. Thus, the ground plane width must be less than ld/4 where ld is the wavelength in the dielectric. Since the center conductor width S is typically less than l/10 to maintain good transverse electromagnetic mode characteristics, it follows that a ground plane width of B = 2S would also be electrically narrow. Thus, we can now treat the ground strips of the FGC waveguide the same way that the center conductor is treated.

  8. SU-E-T-436: Fluence-Based Trajectory Optimization for Non-Coplanar VMAT

    Energy Technology Data Exchange (ETDEWEB)

    Smyth, G; Bamber, JC; Bedford, JL [Joint Department of Physics at The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, London (United Kingdom); Evans, PM [Centre for Vision, Speech and Signal Processing, University of Surrey, Guildford (United Kingdom); Saran, FH; Mandeville, HC [The Royal Marsden NHS Foundation Trust, Sutton (United Kingdom)

    2015-06-15

    Purpose: To investigate a fluence-based trajectory optimization technique for non-coplanar VMAT for brain cancer. Methods: Single-arc non-coplanar VMAT trajectories were determined using a heuristic technique for five patients. Organ at risk (OAR) volume intersected during raytracing was minimized for two cases: absolute volume and the sum of relative volumes weighted by OAR importance. These trajectories and coplanar VMAT formed starting points for the fluence-based optimization method. Iterative least squares optimization was performed on control points 24° apart in gantry rotation. Optimization minimized the root-mean-square (RMS) deviation of PTV dose from the prescription (relative importance 100), maximum dose to the brainstem (10), optic chiasm (5), globes (5) and optic nerves (5), plus mean dose to the lenses (5), hippocampi (3), temporal lobes (2), cochleae (1) and brain excluding other regions of interest (1). Control point couch rotations were varied in steps of up to 10° and accepted if the cost function improved. Final treatment plans were optimized with the same objectives in an in-house planning system and evaluated using a composite metric - the sum of optimization metrics weighted by importance. Results: The composite metric decreased with fluence-based optimization in 14 of the 15 plans. In the remaining case its overall value, and the PTV and OAR components, were unchanged but the balance of OAR sparing differed. PTV RMS deviation was improved in 13 cases and unchanged in two. The OAR component was reduced in 13 plans. In one case the OAR component increased but the composite metric decreased - a 4 Gy increase in OAR metrics was balanced by a reduction in PTV RMS deviation from 2.8% to 2.6%. Conclusion: Fluence-based trajectory optimization improved plan quality as defined by the composite metric. While dose differences were case specific, fluence-based optimization improved both PTV and OAR dosimetry in 80% of cases.

  9. Analysis of "total toxaphene" and selected single congeners in biota by ion trap HRGC-EI-MS/MS using congener-optimized parent ion dissociations.

    Science.gov (United States)

    Skopp, Sonja; Oehme, Michael; Chu, Fong Lam; Yeboah, Faustinus; Chan, Hing Man

    2002-06-15

    A method for the quantification of selected toxaphene congeners as well as "total toxaphene" was developed based on electron ionization (EI) tandem (MS/MS) ion trap mass spectrometry (MS) and a combination of fragment ion dissociations. Congeners were separated by high-resolution gas chromatography. Compared to conventional EI low-resolution MS, a 5-20-fold gain in sensitivity could be obtained for octa- or nonachlorinated compounds such as toxaphene #26 and #62 (according to Parlar nomenclature), allowing for their detection in the low picogram range in biota. In addition, response factors for important congeners such as #26, #32, #40/41, #42, #44, #50, and #62 deviated not more than a factor of 2, which is much less as compared to negative ion chemical ionization. This reduces the risk for systematic errors when determining total toxaphene on the basis of a limited number of reference compounds or the technical mixture. Furthermore, chlordanes and polychlorinated biphenyls did not interfere when applying the proposed MS/MS technique. The applicability of the method was tested by determining both total toxaphene and levels of selected congeners in six Arctic wildlife samples collected from Nunavut, Canada, as well as by repetitive analyses of the SRM 1588 certified reference material.

  10. Coplanar Electrode Layout Optimized for Increased Sensitivity for Electrical Impedance Spectroscopy

    DEFF Research Database (Denmark)

    Clausen, Casper Hyttel; Skands, Gustav Erik; Bertelsen, Christian Vinther;

    2015-01-01

    This work describes an improvement in the layout of coplanar electrodes for electrical impedance spectroscopy. We have developed, fabricated, and tested an improved electrode layout, which improves the sensitivity of an impedance flow cytometry chip. The improved chip was experimentally tested...... and compared to a chip with a conventional electrode layout. The improved chip was able to discriminate 0.5 mu m beads from 1 mu m as opposed to the conventional chip. Furthermore, finite element modeling was used to simulate the improvements in electrical field density and uniformity between the electrodes...... of the new electrode layout. Good agreement was observed between the model and the obtained experimental results....

  11. Mammalian Cytochrome P450-Dependent Metabolism of Polychlorinated Dibenzo-p-dioxins and Coplanar Polychlorinated Biphenyls

    OpenAIRE

    Hideyuki Inui; Toshimasa Itoh; Keiko Yamamoto; Shin-Ichi Ikushiro; Toshiyuki Sakaki

    2014-01-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and coplanar polychlorinated biphenyls (PCBs) contribute to dioxin toxicity in humans and wildlife after bioaccumulation through the food chain from the environment. The authors examined human and rat cytochrome P450 (CYP)-dependent metabolism of PCDDs and PCBs. A number of human CYP isoforms belonging to the CYP1 and CYP2 families showed remarkable activities toward low-chlorinated PCDDs. In particular, human CYP1A1, CYP1A2, and CYP1B1 showed high ac...

  12. Eccentricity generation in hierarchical triple systems with coplanar and initially circular orbits

    CERN Document Server

    Georgakarakos, Nikolaos

    2014-01-01

    We develop a technique for estimating the inner eccentricity in hierarchical triple systems with well separated components. We investigate systems with initially circular and coplanar orbits and comparable masses. The technique is based on an expansion of the rate of change of the Runge-Lenz vector for calculating short period terms by using first order perturbation theory. The combination of the short period terms with terms arising from octupole level secular theory, results in the derivation of a rather simple formula for the eccentricity of the inner binary. The theoretical results are tested against numerical integrations of the full equations of motion. Comparison is also made with other results on the subject.

  13. Driving Rydberg-Rydberg transitions from a co-planar microwave waveguide

    CERN Document Server

    Hogan, S D; Merkt, F; Thiele, T; Filipp, S; Wallraff, A

    2011-01-01

    The coherent interaction between ensembles of helium Rydberg atoms and microwave fields in the vicinity of a solid-state co-planar waveguide is reported. Rydberg-Rydberg transitions, at frequencies between 25 GHz and 38 GHz, have been studied for states with principal quantum numbers in the range 30 - 35 by selective electric-field ionization. An experimental apparatus cooled to 100 K was used to reduce effects of blackbody radiation. Inhomogeneous, stray electric fields emanating from the surface of the waveguide have been characterized in frequency- and time-resolved measurements and coherence times of the Rydberg atoms on the order of 250 ns have been determined.

  14. SU-F-BRB-10: A Statistical Voxel Based Normal Organ Dose Prediction Model for Coplanar and Non-Coplanar Prostate Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Tran, A; Yu, V; Nguyen, D; Woods, K; Low, D; Sheng, K [UCLA, Los Angeles, CA (United States)

    2015-06-15

    Purpose: Knowledge learned from previous plans can be used to guide future treatment planning. Existing knowledge-based treatment planning methods study the correlation between organ geometry and dose volume histogram (DVH), which is a lossy representation of the complete dose distribution. A statistical voxel dose learning (SVDL) model was developed that includes the complete dose volume information. Its accuracy of predicting volumetric-modulated arc therapy (VMAT) and non-coplanar 4π radiotherapy was quantified. SVDL provided more isotropic dose gradients and may improve knowledge-based planning. Methods: 12 prostate SBRT patients originally treated using two full-arc VMAT techniques were re-planned with 4π using 20 intensity-modulated non-coplanar fields to a prescription dose of 40 Gy. The bladder and rectum voxels were binned based on their distances to the PTV. The dose distribution in each bin was resampled by convolving to a Gaussian kernel, resulting in 1000 data points in each bin that predicted the statistical dose information of a voxel with unknown dose in a new patient without triaging information that may be collectively important to a particular patient. We used this method to predict the DVHs, mean and max doses in a leave-one-out cross validation (LOOCV) test and compared its performance against lossy estimators including mean, median, mode, Poisson and Rayleigh of the voxelized dose distributions. Results: SVDL predicted the bladder and rectum doses more accurately than other estimators, giving mean percentile errors ranging from 13.35–19.46%, 4.81–19.47%, 22.49–28.69%, 23.35–30.5%, 21.05–53.93% for predicting mean, max dose, V20, V35, and V40 respectively, to OARs in both planning techniques. The prediction errors were generally lower for 4π than VMAT. Conclusion: By employing all dose volume information in the SVDL model, the OAR doses were more accurately predicted. 4π plans are better suited for knowledge-based planning than

  15. Instrument configuration for dual-Doppler lidar coplanar scans: METCRAX II

    Science.gov (United States)

    Cherukuru, Nihanth Wagmi; Calhoun, Ronald; Lehner, Manuela; Hoch, Sebastian W.; Whiteman, C. David

    2015-01-01

    The second Meteor Crater Experiment (METCRAX II) was designed to study downslope-windstorm-type flows occurring at the Barringer Meteorite Crater in Arizona. Two Doppler wind lidars were deployed to perform a coplanar dual-Doppler lidar analysis to capture the two-dimensional (2-D) vertical structure of these flows in the crater basin. This type of analysis allows the flow to be resolved on a 2-D Cartesian grid constructed in the range height indicator scan overlap region. Previous studies have shown that the dominant error in the coplanar dual-Doppler analysis mentioned above is due to the under sampling of radial velocities. Hence, it is necessary to optimize the setup and choose a scan strategy that minimizes the under sampling of radial velocities and provides a good spatial as well as temporal coverage of these short-lived events. A lidar simulator was developed using a large Eddy simulation wind field to optimize the lidar parameters for METCRAX II field experiment. A retrieval technique based on the weighted least squares technique with weights calculated based on the relative location of the lidar range gate centers to the grid intersection point was developed. The instrument configuration was determined by comparing the simulator retrievals to the background wind field and taking into account the limitations of commercially available lidars.

  16. Control of polymer-packing orientation in thin films through synthetic tailoring of backbone coplanarity

    KAUST Repository

    Chen, Mark S.

    2013-10-22

    Controlling solid-state order of π-conjugated polymers through macromolecular design is essential for achieving high electronic device performance; yet, it remains a challenge, especially with respect to polymer-packing orientation. Our work investigates the influence of backbone coplanarity on a polymer\\'s preference to pack face-on or edge-on relative to the substrate. Isoindigo-based polymers were synthesized with increasing planarity by systematically substituting thiophenes for phenyl rings in the acceptor comonomer. This increasing backbone coplanarity, supported by density functional theory (DFT) calculations of representative trimers, leads to the narrowing of polymer band gaps as characterized by ultraviolet-visible-near infrared (UV-vis-NIR) spectroscopy and cyclic voltammetry. Among the polymers studied, regiosymmetric II and TII polymers exhibited the highest hole mobilities in organic field-effect transistors (OFETs), while in organic photovoltaics (OPVs), TBII polymers that display intermediate levels of planarity provided the highest power conversion efficiencies. Upon thin-film analysis by atomic force microscropy (AFM) and grazing-incidence X-ray diffraction (GIXD), we discovered that polymer-packing orientation could be controlled by tuning polymer planarity and solubility. Highly soluble, planar polymers favor face-on orientation in thin films while the less soluble, nonplanar polymers favor an edge-on orientation. This study advances our fundamental understanding of how polymer structure influences nanostructural order and reveals a new synthetic strategy for the design of semiconducting materials with rationally engineered solid-state properties. © 2013 American Chemical Society.

  17. An Experimental and Numerical Study on Cracking Behavior of Brittle Sandstone Containing Two Non-coplanar Fissures Under Uniaxial Compression

    Science.gov (United States)

    Yang, Sheng-Qi; Tian, Wen-Ling; Huang, Yan-Hua; Ranjith, P. G.; Ju, Yang

    2016-04-01

    To understand the fracture mechanism in all kinds of rock engineering, it is important to investigate the fracture evolution behavior of pre-fissured rock. In this research, we conducted uniaxial compression experiments to evaluate the influence of ligament angle on the strength, deformability, and fracture coalescence behavior of rectangular prismatic specimens (80 × 160 × 30 mm) of brittle sandstone containing two non-coplanar fissures. The experimental results show that the peak strength of sandstone containing two non-coplanar fissures depends on the ligament angle, but the elastic modulus is not closely related to the ligament angle. With the increase of ligament angle, the peak strength decreased at a ligament angle of 60°, before increasing up to our maximum ligament angle of 120°. Crack initiation, propagation, and coalescence were all observed and characterized from the inner and outer tips of pre-existing non-coplanar fissures using photographic monitoring. Based on the results, the sequence of crack evolution in sandstone containing two non-coplanar fissures was analyzed in detail. In order to fully understand the crack evolution mechanism of brittle sandstone, numerical simulations using PFC2D were performed for specimens containing two non-coplanar fissures under uniaxial compression. The results are in good agreement with the experimental results. By analyzing the stress field, the crack evolution mechanism in brittle sandstone containing two non-coplanar fissures under uniaxial compression is revealed. These experimental and numerical results are expected to improve the understanding of the unstable fracture mechanism of fissured rock engineering structures.

  18. Net trophic transfer efficiencies of polychlorinated biphenyl congeners to lake trout (Salvelinus namaycush) from its prey

    Science.gov (United States)

    Madenjian, Charles P.; David, Solomon R.; Rediske, Richard R.; O’Keefe, James P.

    2012-01-01

    Lake trout (Salvelinus namaycush) were fed bloater (Coregonus hoyi) in eight laboratory tanks over a 135-d experiment. At the start of the experiment, four to nine fish in each tank were sacrificed, and the concentrations of 75 polychlorinated biphenyl (PCB) congeners within these fish were determined. Polychlorinated biphenyl congener concentrations were also determined in the 10 lake trout remaining in each of the eight tanks at the end of the experiment as well as in the bloater fed to the lake trout. Each lake trout was weighed at the start and the end of the experiment, and the amount of food eaten by the lake trout was recorded. Using these measurements, net trophic transfer efficiency (γ) from the bloater to the lake trout in each of the eight tanks was calculated for each of the 75 congeners. Results showed that γ did not vary significantly with the degree of chlorination of the PCB congeners, and γ averaged 0.66 across all congeners. However,γ did show a slight, but significant, decrease as logKOW increased from 6.0 to 8.2. Activity level of the lake trout did not have a significant effect on γ.

  19. Separation of 26 toxaphene congeners and measurement in air particulate matter SRMs compared to technical toxaphene SRM 3067.

    Science.gov (United States)

    Vander Pol, Stacy S; Kucklick, John R; Leigh, Stefan D; Porter, Barbara J; Schantz, Michele M

    2010-05-01

    Toxaphene is a complex technical mixture that has been found ubiquitously in the environment but has caused issues for analysis, especially of individual congeners. This paper reports the elution order of 26 major toxaphene congeners on three gas chromatographic columns. The three different stationary phases generally had similar elution orders for the toxaphene congeners, but fewer co-elutions occurred on a low-bleed, low-polarity column. These congeners (except for two that co-eluted and were not added to the calibration mixture) were examined in air particulate matter standard reference materials (SRMs), 1648a, 1649a, and 1649b as well as SRM 3067 toxaphene in methanol for assignment of reference values. SRM 3067 had mass fractions an order of magnitude greater than the air particulate SRMs, which ranged from 0.568 +/- 0.018 ng g(-1) dry mass (B9-2006 in SRM 1648a) to 12.9 +/- 0.20 ng g(-1) dry mass (B9-715 (P 58) in SRM 1649a). The three air particulate SRMs all had different mass fractions and proportions of congeners relative to the sum of the toxaphene congeners. SRM 3067 may be useful as a technical mixture toxaphene congener calibrant. SRMs 1648a and 1649b will serve as reference materials for the analysis of 21 (three congeners were not included due to values below the detection limit or a potential polychlorinated biphenyl co-elution) toxaphene congeners in atmospheric particulate samples.

  20. Comparison of PCB congener profiles in tissues of PCB-treated rats

    Energy Technology Data Exchange (ETDEWEB)

    Kania-Korwel, I.; Ludewig, G.; Robertson, L.W.; Lehmler, H.J. [Dept. of Occupational and Environmental Health, Univ. of Iowa, Iowa City (United States); Hornbuckle, K.C.; Peck, A. [Dept. of Civil and Environmental Engineering, Univ. of Iowa, Iowa City (United States); Sulkowski, W.W. [Dept. of Environmental Chemistry and Technology, Univ. of Silesia, Katowice (Poland)

    2004-09-15

    Information on the congener-specific distribution of PCBs in tissues of laboratory animals after exposure to technical or environmental PCB mixtures is limited. Typically PCB levels and profiles from adipose tissue, liver, blood and occasionally brain are reported. In the work presented here 120 PCB congeners were extracted from 9 tissues of rats exposed to two different PCB mixtures. One mixture was Aroclor 1254, a well studied technical mixture. The second mixture was an environmental mixture obtained after extraction of soil contaminated with Chlorofen, a highly chlorinated Polish PCB mixture. The study was designed to investigate how different chlorination levels and the structure of PCB congeners affect their distribution and total concentration in selected tissues. Principal Component Analysis and Hierarchical Cluster Analysis were employed to compare tissues of Aroclor and soil extract-treated animals.

  1. Qualitative Properties of Orbits for Minimum-Fuel Impulsive Transfers between Circular Coplanar Orbits with a Given Launch Time

    Science.gov (United States)

    Kirpichnikov, S. N.; Vorobyev, A. Yu.; Teterin, S. N.

    2003-09-01

    The coplanar problem of minimizing propellant consumption in impulsive transfer between circular boundary orbits is investigated. The launch time and the initial configuration of objects on the boundary orbits are specified arbitrarily. The qualitative properties of optimal two-impulse trajectories and their optimality in the class of multi-impulse transfers are studied.

  2. Extensions to the quasi-static expressions for the line parameters of coplanar waveguide with relatively thick conductors

    Science.gov (United States)

    Co-planar waveguide (CPW) transmission line can be configured as a sensor to measure the complex permittivity of biological materials. By placing a material with unknown permittivity on the CPW and measuring the scattering parameters with a vector network analyzer, the characteristic impedance and e...

  3. An ultra-wideband dielectric material characterization method using grounded coplanar waveguide and genetic algorithm optimization

    Science.gov (United States)

    Hadjloum, Massinissa; El Gibari, Mohammed; Li, Hongwu; Daryoush, Afshin S.

    2015-10-01

    An ultra-wideband complex permittivity extraction method is reported here using numerical fitting of scattering parameters to measured results. A grounded coplanar waveguide transmission line is realized on an unknown dielectric material, whose dielectric constant and loss tangent are extracted by the best fitting of the simulated magnitude, |S21|, and phase, ϕ21, of forward scattering parameter using an electromagnetic full-wave simulator (high frequency structure simulator) to the measured results. The genetic algorithm is employed for optimum rapid extraction, where errors between the numerically simulated and measured S21 (|S21| and ϕ21) are minimized in an iterative manner. As long as the convergence criterion is not satisfied, modifications to dielectric properties are made with this genetic algorithm implemented in Matlab. Feasibility of this extraction technique is validated on benzocyclobutane polymer from 10 MHz to 40 GHz.

  4. CIRCULARLY POLARIZED SLOTTED APERTURE ANTENNA WITH COPLANAR WAVEGUIDE FED FOR BROADBAND APPLICATIONS

    Directory of Open Access Journals (Sweden)

    B. T. P. MADHAV

    2016-02-01

    Full Text Available Coplanar waveguide fed circularly polarized microstrip patch antenna performance evaluation is presented in this paper. The broadband characteristics are attained by placing open end slot at the lower side of the antenna. The proposed design has the return loss of less than -10dB and VSWR<2 in the desired band of operation. A gain of 3dB to 4dB is attained in the desired band with good radiation characteristics and a suitable axial ratio of less than 3 dB is attained in the prescribed band of operation. Proposed antenna is fabricated on the FR4 substrate with dielectric constant of 4.4. Parametric analysis with change in substrate permittivity also performed and the optimized dimensions are presented in this work.

  5. Self-aligned coplanar amorphous indium zinc oxide thin-film transistors with high performance

    Science.gov (United States)

    Park, Jae Chul; Lee, Ho-Nyeon

    2015-01-01

    Self-aligned coplanar amorphous indium zinc oxide thin-film transistors (a-IZO TFTs) were fabricated. The a-IZO TFTs had a field-effect mobility of μFE = 24.4 cm2 V-1 s-1, a subthreshold slope of 180 mV/dec, and an on/off ratio of 109. As the channel length decreased, the threshold voltage VTH shifted to more negative voltages, and μFE increased due to the diffused carriers from the contact regions. The intrinsic field-effect mobility was estimated to be 15.05 cm2 V-1 s-1 in the linear mode and 13.28 cm2 V-1 s-1 in saturation mode. Under positive/negative bias-temperature-illumination stress, the shift in VTH was less than ±0.7 V after 11,000 s.

  6. A note on the total least squares problem for coplanar points

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.L.

    1994-09-01

    The Total Least Squares (TLS) fit to the points (x{sub k}, y{sub k}), k = 1, {hor_ellipsis}, n, minimizes the sum of the squares of the perpendicular distances from the points to the line. This sum is the TLS error, and minimizing its magnitude is appropriate if x{sub k} and y{sub k} are uncertain. A priori formulas for the TLS fit and TLS error to coplanar points were originally derived by Pearson, and they are expressed in terms of the mean, standard deviation and correlation coefficient of the data. In this note, these TLS formulas are derived in a more elementary fashion. The TLS fit is obtained via the ordinary least squares problem and the algebraic properties of complex numbers. The TLS error is formulated in terms of the triangle inequality for complex numbers.

  7. Design of an Ultra-Wideband Transition from Double-Sided Parallel Stripline to Coplanar Waveguide

    Directory of Open Access Journals (Sweden)

    Young-Gon Kim

    2013-01-01

    Full Text Available A design method of an ultra-wideband transition from double-sided parallel stripline (DSPSL to coplanar waveguide (CPW is proposed based on analytical expressions of characteristic impedance. The conformal mapping is used to obtain the characteristic impedance for each section of the transition within 3.7% accuracy as compared with the EM simulation results. An efficient and clear guideline for the design of the transition is proposed. The implemented transition performs less than 0.6 dB insertion loss per transition for frequencies from 40 MHz to 12 GHz and less than 1.2 dB insertion loss to 27 GHz, which well exceeds the previous results in the literature.

  8. The geometry of three-dimensional measurement from paired coplanar x-ray images.

    Science.gov (United States)

    Baumrind, S; Moffitt, F H; Curry, S

    1983-10-01

    This article outlines the geometric principles which underlie the process of making craniofacial measurements in three dimensions by combining information from pairs of coplanar x-ray images. The main focus is upon the rationale of the method rather than upon the computational details. We stress particularly the importance of having available accurate measurements as to the relative positions of the x-ray tubes and the film plane. The use of control arrays of radiopaque "points" whose projected images upon the film plane allow the retrospective calculation of the spatial relationship between the x-ray tubes and the film plane is explained. Finally, the question of correcting for movement of the subject between two films of an image pair is considered briefly.

  9. Planar self-aligned imprint lithography for coplanar plasmonic nanostructures fabrication

    KAUST Repository

    Wan, Weiwei

    2014-03-01

    Nanoimprint lithography (NIL) is a cost-efficient nanopatterning technology because of its promising advantages of high throughput and high resolution. However, accurate multilevel overlay capability of NIL required for integrated circuit manufacturing remains a challenge due to the high cost of achieving mechanical alignment precision. Although self-aligned imprint lithography was developed to avoid the need of alignment for the vertical layered structures, it has limited usage in the manufacture of the coplanar structures, such as integrated plasmonic devices. In this paper, we develop a new process of planar self-alignment imprint lithography (P-SAIL) to fabricate the metallic and dielectric structures on the same plane. P-SAIL transfers the multilevel imprint processes to a single-imprint process which offers higher efficiency and less cost than existing manufacturing methods. Such concept is demonstrated in an example of fabricating planar plasmonic structures consisting of different materials. © 2014 Springer-Verlag Berlin Heidelberg.

  10. Uniplanar Millimeter-Wave Log-Periodic Dipole Array Antenna Fed by Coplanar Waveguide

    Directory of Open Access Journals (Sweden)

    Guohua Zhai

    2013-01-01

    Full Text Available A uniplanar millimeter-wave broadband printed log-periodic dipole array (PLPDA antenna fed by coplanar waveguide (CPW is introduced. This proposed structure consists of several active dipole elements, feeding lines, parallel coupled line, and the CPW, which are etched on a single metallic layer of the substrate. The parallel coupled line can be optimized to act as a transformer between the CPW and the PLPDA antenna. Meanwhile, this transform performs the task of a balun to achieve a wideband, low cost, low loss, simple directional antenna. The uniplanar nature makes the antenna suitable to be integrated into modern printed communication circuits, especially the monolithic millimeter-wave integrated circuits (MMIC. The antenna has been carefully examined and measured to present the return loss, far-field patterns, and antenna gain.

  11. On the Nonlinear Stability of Plane Parallel Shear Flow in a Coplanar Magnetic Field

    Science.gov (United States)

    Xu, Lanxi; Lan, Wanli

    2016-10-01

    Lyapunov direct method has been used to study the nonlinear stability of laminar flow between two parallel planes in the presence of a coplanar magnetic field for streamwise perturbations with stress-free boundary planes. Two Lyapunov functions are defined. By means of the first, it is proved that the transverse components of the perturbations decay unconditionally and asymptotically to zero for all Reynolds numbers and magnetic Reynolds numbers. By means of the second, it is showed that the other components of the perturbations decay conditionally and exponentially to zero for all Reynolds numbers and the magnetic Reynolds numbers below π ^2/2M , where M is the maximum of the absolute value of the velocity field of the laminar flow.

  12. Three-dimensional x-ray stereometry from paired coplanar images: a progress report.

    Science.gov (United States)

    Baumrind, S; Moffitt, F H; Curry, S

    1983-10-01

    More than fifty years ago, Broadbent reported the development of a three-dimensional cephalometric method which complexed information from pairs of x-ray images oriented in two planes at right angles to each other. Empirical problems have prevented the routine clinical use of this "biplanar" method, notwithstanding its obvious conceptual brilliance. The present article reports on recent work toward the development of an alternative method of three-dimensional cephalometry in which the two images of each x-ray pair are positioned in the same plane rather than being at right angles to each other. It is believed that this "coplanar" method avoids many of the technical problems that have limited the use of the Broadbent method.

  13. CyberArc: a non-coplanar-arc optimization algorithm for CyberKnife

    Science.gov (United States)

    Kearney, Vasant; Cheung, Joey P.; McGuinness, Christopher; Solberg, Timothy D.

    2017-07-01

    The goal of this study is to demonstrate the feasibility of a novel non-coplanar-arc optimization algorithm (CyberArc). This method aims to reduce the delivery time of conventional CyberKnife treatments by allowing for continuous beam delivery. CyberArc uses a 4 step optimization strategy, in which nodes, beams, and collimator sizes are determined, source trajectories are calculated, intermediate radiation models are generated, and final monitor units are calculated, for the continuous radiation source model. The dosimetric results as well as the time reduction factors for CyberArc are presented for 7 prostate and 2 brain cases. The dosimetric quality of the CyberArc plans are evaluated using conformity index, heterogeneity index, local confined normalized-mutual-information, and various clinically relevant dosimetric parameters. The results indicate that the CyberArc algorithm dramatically reduces the treatment time of CyberKnife plans while simultaneously preserving the dosimetric quality of the original plans.

  14. Dispersion characteristics of optically excited coplanar striplines - Comprehensive full-wave analysis

    Science.gov (United States)

    Phatak, Dhananjay S.; Defonzo, A. P.; Das, Nirod K.

    1990-11-01

    A comprehensive full-wave formulation is developed to evaluate the dispersion and losses for coplanar striplines on substrates of finite and infinite thicknesses is presented. The loss mechanisms incorporated in the analysis are substrate losses and dielectric material losses. The method of Das and Pozar (1987) is generalized to include a complex propagation vector and can be used over a wide frequency range. A large range of line dimensions can also be handled, limits being set by the accuracy of the moment method. Metal losses can also be incorporated into this analysis by applying the appropriate boundary conditions for lossy metal. Analytically, the excitation of substrate modes is shown to correspond to the occurrence of the poles of the Green function in the reaction integrals. Results of the full-wave analysis are in good agreement with those obtained by established theory.

  15. Coplanar Electrode Layout Optimized for Increased Sensitivity for Electrical Impedance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Casper Hyttel Clausen

    2014-12-01

    Full Text Available This work describes an improvement in the layout of coplanar electrodes for electrical impedance spectroscopy. We have developed, fabricated, and tested an improved electrode layout, which improves the sensitivity of an impedance flow cytometry chip. The improved chip was experimentally tested and compared to a chip with a conventional electrode layout. The improved chip was able to discriminate 0.5 μm beads from 1 μm as opposed to the conventional chip. Furthermore, finite element modeling was used to simulate the improvements in electrical field density and uniformity between the electrodes of the new electrode layout. Good agreement was observed between the model and the obtained experimental results.

  16. Significance of coplanar macrocells to corrosion in concrete-embedded steel

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, P. [Univ. Autonoma de Nuevo Leon (Mexico); Ramirez, E. [Inst. de Investigacion Tecnologica Industrial y de Normas Tecnicas, Lima (Peru); Feliu, S.; Gonzalez, J.A. [Centro Nacional de Investigaciones Metalurgicas, Madrid (Spain); Lopez, W. [CEMEX, S.A. Monterrey (Mexico)

    1999-03-01

    The influence of microcells and galvanic macrocells on the corrosion kinetics of concrete-embedded steel was investigated experimentally. Nine stainless steel/carbon steel coplanar macrocouples in cathodic-to-anodic ratios of 0.02 to 50 were cast in concrete slabs made from cement, sand, and water in a 1:3:0:5 proportion plus 2% calcium chloride (CaCl{sub 2}) per cement weight. Corrosion potential (E{sub corr}), galvanic current (i{sub g}), polarization resistance (R{sub p}), and impedance measurements from 100 kHz to 0.01 Hz were made for the two metals, coupled and uncoupled. i{sub g} data provided by a zero resistance ammeter led to potentially underestimated corrosion rates for anodic areas, whereas R{sub p} measurements provided fairly reliable corrosion rates. Macrocells polarized anodic areas very slightly at points where an anodic and a cathodic process took place simultaneously.

  17. Characterization of a large CdZnTe coplanar quad-grid semiconductor detector

    CERN Document Server

    Ebert, Joachim; Gehre, Daniel; Hagner, Caren; Heidrich, Nadine; Klingenberg, Rainer; Kröninger, Kevin; Nitsch, Christian; Oldorf, Christian; Quante, Thomas; Rajek, Silke; Rebber, Henning; Rohatsch, Katja; Tebrügge, Jan; Temminghoff, Robert; Theinert, Robert; Timm, Jan; Wonsak, Björn; Zatschler, Stefan; Zuber, Kai

    2015-01-01

    The COBRA collaboration aims to search for neutrinoless double beta-decay of $^{116}$Cd. A demonstrator setup with 64 CdZnTe semiconductor detectors, each with a volume of 1cm$^3$, is currently being operated at the LNGS underground laboratory in Italy. This paper reports on the characterization of a large (2 $\\times$ 2 $\\times$ 1.5)cm$^3$ CdZnTe detector with a new coplanar-grid design for applications in $\\gamma$-ray spectroscopy and low-background operation. Several studies of electric properties as well as of the spectrometric performance, like energy response and resolution, are conducted. Furthermore, measurements including investigating the operational stability and a possibility to identify multiple-scattered photons are presented.

  18. Diffuse coplanar surface barrier discharge -- basic properties and its application in surface treatment of nonwovens

    Science.gov (United States)

    Kovacik, Dusan; Rahel, Jozef; Kubincova, Jana; Zahoranova, Anna; Cernak, Mirko

    2009-10-01

    In recent years, low temperature atmospheric pressure plasma surface treatments have become a hot topic because of the potential of fast and efficient in-line processing fabrication without expensive vacuum equipment. A major problem of atmospheric pressure treatment in air is insufficient treatment uniformity because, particularly at the higher plasma power densities, the air plasma has the tendency of filamentation and transition into an arc discharge. Diffuse coplanar surface barrier discharge (DCSBD) plasma source has been developed to overcome these problems. This type of discharge enables to generate macroscopically homogeneous thin (˜ 0.3 mm) plasma layer with power density of some 100 W/cm^3 practically in any gas without admixture of He. It was found that the ambient air plasma of DCSBD is capable to make lightweight polypropylene nonwoven fabrics permanently hydrophilic, without any pinholing and with low power consumption of some 1 kWh/kg.

  19. Electron impact ionization of Li+ (ls2) in the coplanar equal energy-sharing geometry

    Institute of Scientific and Technical Information of China (English)

    贾祥富; 刘明海

    2002-01-01

    In this paper, the triple differential cross section for the low-energy electron impact ionization of the Li+ ionis considered in the coplanar equal energy-sharing kinematics at an incident energy of 114.083eV. The emergence of structures in the calculated cross sections is explained in terms of isolated two-body final-state interactions and three-body coupling. The cross section shows two peaks originating from ‘classical' sequential two-body collisions. The position of these peaks is determined by two-body final-state interactions. In addition, it is demonstrated that the signature of three-body interactions is carried by the magnitude and ratio of these two peaks. The direct and exchange amplitudes are also considered.

  20. UHF coplanar-slot antenna for aircraft-to-satellite data communications

    Science.gov (United States)

    Myhre, R. W.

    1979-01-01

    The initiative for starting the Aircraft-to-Satellite Data Relay (ASDAR) Program came from a recognition that much of the world's weather originates in the data sparse area of the tropics which are primarily ocean. The ASDAR system consists of (1) a data acquisition and control unit to acquire, store and format these data; (2) a clock to time the data sampling and transmission periods; and (3) a transmitter and low-profile upper hemisphere coverage antenna to relay the formatted data via satellite to the National Weather Service ground stations, as shown schematically. The low-profile antenna is a conformal antenna based on the coplanar-slot approach. The antenna is circular polarized and has an on-axis gain of nearly 2.5 dB and a HPBW greater than 90 deg. The discussion covers antenna design, radiation characteristics, flight testing, and system performance.

  1. Orbital instability of close-in exomoons in non-coplanar systems

    CERN Document Server

    Hong, Yu-Cian; Nicholson, Philip D; Lunine, Jonathan I

    2015-01-01

    This work shows the dynamical instability that can happen to close-in satellites when planet oblateness is not accounted for in non-coplanar multiplanet systems. Simulations include two secularly interacting Jupiter-mass planets mutually inclined by 10 degrees, with the host planet either oblate or spherical. With a spherical host planet, moons within a critical planetocentric distance experience high inclinations and in some cases high eccentricities, while more distant moons orbit stably with low inclinations and eccentricities, as expected. These counter-intuitive dynamical phenomena disappear with an oblate host planet, in which case the moons' Laplace plane transitions from the host planet's equatorial plane to the host planet's precessing orbital plane as their semi-major axes increase, and all moons are dynamically stable with very mild changes in orbits. Direct perturbation from the perturbing planet has been investigated and ruled out as an explanation for the behavior of the innermost satellites, th...

  2. A Reconfigurable Coplanar Waveguide Bowtie Antenna Using an Integrated Ferroelectric Thin-Film Varactor

    Directory of Open Access Journals (Sweden)

    K. C. Pan

    2012-01-01

    Full Text Available A novel printed antenna with a frequency reconfigurable feed network is presented. The antenna consists of a bowtie structure patch radiating element in the inner space of an annulus that is on a nongrounded substrate with a ferroelectric (FE Barium Strontium Titanate (BST thin film. The bowtie patch is fed by a coplanar waveguide (CPW transmission line that also includes a CPW-based BST shunt varactor. Reconfiguration of the compact 8 mm × 8 mm system has been demonstrated by shifting the antenna system’s operating frequency 500 MHz in the 7–9 GHz band by applying a DC voltage bias.

  3. Simulation of the superconducting multiturn flux transformer integrated with a coplanar resonator

    Science.gov (United States)

    Yi, H. R.; Zhang, Y.; Klein, N.

    2000-06-01

    The analysis of the structure of a superconducting multiturn flux transformer integrated with a coplanar resonator for radio-frequency superconducting quantum interference devices is described. Electromagnetic simulations indicate that the loss is dominated by the high loss tangent of the dielectric film used for the separation of the upper and lower superconducting films. The simulated current distribution at its resonant frequency shows that the highest current density is distributed on the multiturn input coil. This current distribution leads to a very high loss when the loss tangent of the dielectric film is high. However, for the same loss tangent of the dielectric film, it is possible to get a reasonably high unloaded quality factor by providing a normal shunt for the multiturn input coil.

  4. Inactivation of Escherichia coli on PTFE surfaces by diffuse coplanar surface barrier discharge

    Science.gov (United States)

    Tučeková, Zlata; Koval'ová, Zuzana; Zahoranová, Anna; Machala, Zdenko; Černák, Mirko

    2016-08-01

    The non-equilibrium plasma of diffuse coplanar surface barrier discharge (DCSBD) was tested for decontamination of bacteria Escherichia coli on polymer surfaces. We investigated the optical parameters of DCSBD plasma generated in synthetic air with different relative humidity. Our study was provided to estimate the main plasma components active during the DCSBD plasma degradation of E. coli contamination prepared on polytetrafluoroethylene (PTFE, Teflon) surface, in ambient air at atmospheric pressure. The DCSBD plasma was characterized by means of electrical measurements and optical emission spectroscopy. The inactivation of E. coli bacteria was evaluated by standard microbiological cultivation (CFU plate counting). The experimental results of the germicidal efficiency obtained for short plasma exposure times proved the effectiveness of DCSBD plasma for the polymer surface decontamination. Contribution to the topical issue "6th Central European Symposium on Plasma Chemistry (CESPC-6)", edited by Nicolas Gherardi, Ester Marotta and Cristina Paradisi

  5. Quasidiscrete microwave solitons in a split-ring-resonator-based left-handed coplanar waveguide.

    Science.gov (United States)

    Veldes, G P; Cuevas, J; Kevrekidis, P G; Frantzeskakis, D J

    2011-04-01

    We study the propagation of quasidiscrete microwave solitons in a nonlinear left-handed coplanar waveguide coupled with split-ring resonators. By considering the relevant transmission line analog, we derive a nonlinear lattice model which is studied analytically by means of a quasidiscrete approximation. We derive a nonlinear Schrödinger equation, and find that the system supports bright envelope soliton solutions in a relatively wide subinterval of the left-handed frequency band. We perform systematic numerical simulations, in the framework of the nonlinear lattice model, to study the propagation properties of the quasidiscrete microwave solitons. Our numerical findings are in good agreement with the analytical predictions, and suggest that the predicted structures are quite robust and may be observed in experiments.

  6. Electromagnetic Modeling of Distributed-Source-Excitation of Coplanar Waveguides: Applications to Traveling-Wave Photomixers

    Science.gov (United States)

    Pasqualini, Davide; Neto, Andrea; Wyss, Rolf A.

    2001-01-01

    In this work an electromagnetic model and subsequent design is presented for a traveling-wave, coplanar waveguide (CPW) based source that will operate in the THz frequency regime. The radio frequency (RF) driving current is a result of photoexcitation of a thin GaAs membrane using two frequency-offset lasers. The GaAs film is grown by molecular-beam-epitaxy (MBE) and displays sub-ps carrier lifetimes which enable the material conductivity to be modulated at a very high rate. The RF current flows between electrodes deposited on the GaAs membrane which are biased with a DC voltage source. The electrodes form a CPW and are terminated with a double slot antenna that couples the power to a quasi-optical system. The membrane is suspended above a metallic reflector to launch all radiation in one direction. The theoretical investigation and consequent design is performed in two steps. The first step consists of a direct evaluation of the magnetic current distribution on an infinitely extended coplanar waveguide excited by an impressed electric current distributed over a finite area. The result of the analysis is the difference between the incident angle of the laser beams and the length of the excited area that maximizes the RF power coupled to the CPW. The optimal values for both parameters are found as functions of the CPW and membrane dimensions as well as the dielectric constants of the layers. In the second step, a design is presented of a double slot antenna that matches the CPW characteristic impedance and gives good overall performance. The design is presently being implemented and measurements will soon be available.

  7. Congener-specific polychlorinated biphenyl patterns in eggs of aquatic birds from the lower Laguna Madre, Texas

    Science.gov (United States)

    Mora, Miguel A.

    1996-01-01

    Eggs from four aquatic bird species nesting in the Lower Laguna Madre, Texas, were collected to determine differences and similarities in the accumulation of congener-specific polychlorinated biphenyls (PCBs) and to evaluate PCB impacts on reproduction. Because of the different toxicities of PCB congeners, it is important to know which congeners contribute most to total PCBs. The predominant PCB congeners were 153, 138, 180, 110, 118, 187, and 92. Collectively, congeners 153, 138, and 180 accounted for 26 to 42% of total PCBs. Congener 153 was the most abundant in Caspian terns (Sterna caspia) and great blue herons (Ardea herodias) and congener 138 was the most abundant in snowy egrets (Egretta thula) and tricolored herons (Egretta tricolor). Principal component analysis indicated a predominance of higher chlorinated biphenyls in Caspian terns and great blue herons and lower chlorinated biphenyls in tricolored herons. Snowy egrets had a predominance of pentachlorobiphenyls. These results suggest that there are differences in PCB congener patterns in closely related species and that these differences are more likely associated with the species' diet rather than metabolism. Total PCBs were significantly greater (p Laguna Madre were below concentrations known to affect bird reproduction.

  8. Congener-specific polychlorinated biphenyl patterns in eggs of aquatic birds from the Lower Laguna Madre, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Mora, M.A. [Texas A and M Univ., College Station, TX (United States)

    1996-06-01

    Eggs from four aquatic bird species nesting in the Lower Laguna Madre, Texas, were collected to determine differences and similarities in the accumulation of congener-specific polychlorinated biphenyls (PCBs) and to evaluate PCB impacts on reproduction. Because of the different toxicities of PCB congeners, it is important to know which congeners contribute most to total PCBs. The predominant PCB congeners were 153, 138, 180, 110, 118, 187, and 92. Collectively, congeners 153, 138, and 180 accounted for 26 to 42% of total PCBs. Congener 153 was the most abundant in Caspian terns (Sterna caspia) and great blue herons (Ardea herodias) and congener 138 was the most abundant in snowy egrets (Egretta thula) and tricolored herons (Egretta tricolor). Principal component analysis indicated a predominance of higher chlorinated biphenyls in Caspian terns and great blue herons and lower chlorinated biphenyls in tricolored herons. Snowy egrets had a predominance of pentachlorobiphenyls. These results suggest that there are differences in PCB congener patterns in closely related species and that these differences are more likely associated with the species` diet rather than metabolism. Total PCBs were significantly greater (p < 0.05) in Caspian terns than in the other species. Overall, PCBs in eggs of birds from the Lower Laguna Madre were below concentrations known to affect bird reproduction.

  9. Predicting sediment sorption coefficients for linear alkylbenzenesulfonate congeners from polyacrylate-water partition coefficients at different salinities.

    NARCIS (Netherlands)

    Rico Rico, A.; Droge, S.T.J.; Hermens, J.L.M.

    2010-01-01

    The effect of the molecular structure and the salinity on the sorption of the anionic surfactant linear alkylbenzenesulfonate (LAS) to marine sediment has been studied. The analysis of several individual LAS congeners in seawater and of one specific LAS congener at different dilutions of seawater wa

  10. Very mild disease phenotype of congenic CftrTgH(neoim)Hgu cystic fibrosis mice

    NARCIS (Netherlands)

    B. Tóth (Balázs); M. Wilke (Martina); F. Stanke (Frauke); M. Dorsch (Martina); S. Jansen (Silke); D. Wedekind (Dirk); N. Charizopoulou (Nikoletta); A.G. Bot (Alice); M. Burmester (Marion); S. Leonhard-Marek (Sabine); H.R. de Jonge (Hugo); H.J. Hedrich; G. Breves (Gerhard); B. Tümmler (Burkhard)

    2008-01-01

    textabstractBackground: A major boost to cystic fibrosis disease research was given by the generation of various mouse models using gene targeting in embryonal stem cells. Moreover, the introduction of the same mutation on different inbred strains generating congenic strains facilitated the search f

  11. ANALYSIS OF CHIRAL PESTICIDES AND POLYCHLORINATED BIPHENYL CONGENERS IN ENVIRONMENTAL SAMPLES

    Science.gov (United States)

    Over 25 % of pesticides and other toxic organic pollutants are chiral, as are 19 of the 209 polychlorinated biphenyl (PCB) congeners; that is, they exist as two mirror image species called enantiomers (PCB enantiomers are called atropisomers). The enantiomers of a chiral compound...

  12. [Determination of seven toxaphene congeners in ginseng and milkvetch root by gas chromatography tandem mass spectrometry].

    Science.gov (United States)

    Tian, Shaoqiong; Mao, Xiuhong; Miao, Shui; Jia, Zhengwei; Wang, Ke; Ji, Shen

    2012-01-01

    A novel method for the determination of representative toxaphene congeners in traditional Chinese herbal medicines was developed. Ginseng and Milkvetch Root were selected as the samples and seven toxaphene congeners were selected as the monitoring objects. The samples were extracted by accelerated solvent extraction with cyclohexane-acetone (9:1, v/v), then cleaned-up by Florisil solid phase extraction with hexane as the eluent and the residues were detected by gas chromatography-electron ionization tandem mass spectrometry (GC-EI-MS/MS) in multiple reaction monitoring (MRM) mode. The performance was demonstrated by the analysis of Ginseng and Milkvetch Root samples spiked with toxaphene congeners at three concentration levels of 0.005, 0.01 and 0.1 mg/kg. The recoveries ranged from 72.4% to 105% with the relative standard deviations (RSDs) of 0.96%-10.4%. The limits of detection (LODs) were 0.2-1.7 microg/kg. This method is sensitive and efficient in the aspect of extraction, and can be applied to monitor the residue of toxaphene congeners in Ginseng and Milkvetch Root.

  13. DIFFERENTIAL EFFECTS OF TWO LOTS OF AROCLOR 1254R: CONGENER ANALYSIS AND NEUROCHEMICAL ENDPOINTS.

    Science.gov (United States)

    IntroductionPolychlorinated biphenyls (PCBs) are widely used in industry as heat transfer and dielectric fluids for transformers and capacitors1. PCBs were commercially produced as AroclorR mixtures in USA by the chlorination of biphenyl. Although all 209 congeners can be syn...

  14. Micelles versus Ribbons: How Congeners Drive the Self-Assembly of Acidic Sophorolipid Biosurfactants.

    Science.gov (United States)

    Dhasaiyan, Prabhu; Le Griel, Patrick; Roelants, Sophie; Redant, Emile; Van Bogaert, Inge N A; Prevost, Sylvain; Prasad, B L V; Baccile, Niki

    2017-03-17

    Sophorolipids (SLs), a class of microbially derived biosurfactants, are reported by different research groups to have different self-assembled structures (either micelles or giant ribbons) under the same conditions. Here we explore the reasons behind these contradictory results and attribute these differences to the role of specific congeners that are present in minute quantities. We show that a sample composed of a majority of oleic acid (C18:1) sophorolipid in the presence of only 0.5 % (or more) of congeners with stearic acid (C18:0) or linoleic acid (C18:2) results in the formation of micelles that are stable over long periods of time. Conversely, the presence of only 10 to 15 % of congeners with a stearic acid chain gives fibrillar structures instead of micelles. To study the mechanisms responsible, oleic acid SLs devoid of any other congeners were prepared. Very interestingly, this sample can self-assemble into either micelles or fibers depending on minute modifications to the self-assembly conditions. The findings are supported by light scattering, small-angle X-ray scattering, transmission electron microscopy under cryogenic conditions, high-pressure liquid chromatography, and NMR spectroscopy.

  15. Congener specificity in the accumulation of dioxins and dioxin-like compounds in zucchini plants grown hydroponically.

    Science.gov (United States)

    Inui, Hideyuki; Wakai, Taketo; Gion, Keiko; Yamazaki, Kiyoshi; Kim, Yun-Seok; Eun, Heesoo

    2011-01-01

    Zucchini cultivars Cucurbita pepo subsp. ovifera cv. Patty Green and subsp. pepo cv. Gold Rush were cultivated hydroponically in a nutrient solution supplemented with a mixture of dioxins and dioxin-like compounds. Patty Green and Gold Rush showed low and high accumulation of these compounds in the aerial parts respectively. In both cultivars, the accumulation of each congener negatively depended on its hydrophobicity. This suggests that desorption and solubilization were partly responsible for congener specificity of accumulation, since this was not found in soil experiments. In contrast, no clear difference in accumulation in the roots was observed between the cultivars, whereas the translocation factors, which are indicators of efficient translocation from the roots to the aerial parts, differed among the congeners hydrophobicity-dependently. There were positive correlations between accumulation in the roots and the hydrophobicity of the polychlorinated biphenyl congeners in both cultivars. These results indicate that translocation was also partly responsible for the congener specificity and accumulation concentrations.

  16. Elimination Rates of Dioxin Congeners in Former Chlorophenol Workers from Midland, Michigan

    Science.gov (United States)

    Collins, James J.; Bodner, Kenneth M.; Wilken, Michael; Bodnar, Catherine M.

    2012-01-01

    Background: Exposure reconstructions and risk assessments for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other dioxins rely on estimates of elimination rates. Limited data are available on elimination rates for congeners other than TCDD. Objectives: We estimated apparent elimination rates using a simple first-order one-compartment model for selected dioxin congeners based on repeated blood sampling in a previously studied population. Methods: Blood samples collected from 56 former chlorophenol workers in 2004–2005 and again in 2010 were analyzed for dioxin congeners. We calculated the apparent elimination half-life in each individual for each dioxin congener and examined factors potentially influencing elimination rates and the impact of estimated ongoing background exposures on rate estimates. Results: Mean concentrations of all dioxin congeners in the sampled participants declined between sampling times. Median apparent half-lives of elimination based on changes in estimated mass in the body were generally consistent with previous estimates and ranged from 6.8 years (1,2,3,7,8,9-hexachlorodibenzo-p-dioxin) to 11.6 years (pentachlorodibenzo-p-dioxin), with a composite half-life of 9.3 years for TCDD toxic equivalents. None of the factors examined, including age, smoking status, body mass index or change in body mass index, initial measured concentration, or chloracne diagnosis, was consistently associated with the estimated elimination rates in this population. Inclusion of plausible estimates of ongoing background exposures decreased apparent half-lives by approximately 10%. Available concentration-dependent toxicokinetic models for TCDD underpredicted observed elimination rates for concentrations dioxin compounds. PMID:23063871

  17. Correlation between human maternal-fetal placental transfer and molecular weight of PCB and dioxin congeners/isomers.

    Science.gov (United States)

    Mori, Chisato; Nakamura, Noriko; Todaka, Emiko; Fujisaki, Takeyoshi; Matsuno, Yoshiharu; Nakaoka, Hiroko; Hanazato, Masamichi

    2014-11-01

    Establishing methods for the assessment of fetal exposure to chemicals is important for the prevention or prediction of the child's future disease risk. In the present study, we aimed to determine the influence of molecular weight on the likelihood of chemical transfer from mother to fetus via the placenta. The correlation between molecular weight and placental transfer rates of congeners/isomers of polychlorinated biphenyls (PCBs) and dioxins was examined. Twenty-nine sample sets of maternal blood, umbilical cord, and umbilical cord blood were used to measure PCB concentration, and 41 sample sets were used to analyze dioxins. Placental transfer rates were calculated using the concentrations of PCBs, dioxins, and their congeners/isomers within these sample sets. Transfer rate correlated negatively with molecular weight for PCB congeners, normalized using wet and lipid weights. The transfer rates of PCB or dioxin congeners differed from those of total PCBs or dioxins. The transfer rate for dioxin congeners did not always correlate significantly with molecular weight, perhaps because of the small sample size or other factors. Further improvement of the analytical methods for dioxin congeners is required. The findings of the present study suggested that PCBs, dioxins, or their congeners with lower molecular weights are more likely to be transferred from mother to fetus via the placenta. Consideration of chemical molecular weight and transfer rate could therefore contribute to the assessment of fetal exposure. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Comparison of a new noncoplanar intensity-modulated radiation therapy technique for craniospinal irradiation with 3 coplanar techniques

    DEFF Research Database (Denmark)

    Hansen, Anders T; Lukacova, Slavka; Lassen-Ramshad, Yasmin A.;

    2015-01-01

    patient using the noncoplanar IMRT-based technique, a coplanar IMRT-based technique, and a coplanar volumetric-modulated arch therapy (VMAT) technique. Dosimetry data for all patients were compared with the corresponding data from the conventional treatment plans. The new noncoplanar IMRT technique......When standard conformal x-ray technique for craniospinal irradiation is used, it is a challenge to achieve satisfactory dose coverage of the target including the area of the cribriform plate, while sparing organs at risk. We present a new intensity-modulated radiation therapy (IMRT), noncoplanar...... technique, for delivering irradiation to the cranial part and compare it with 3 other techniques and previously published results. A total of 13 patients who had previously received craniospinal irradiation with standard conformal x-ray technique were reviewed. New treatment plans were generated for each...

  19. A Ka-band monolithic low phase noise coplanar waveguide oscillator using InAlAs/InGaAs HBT

    Science.gov (United States)

    Cui, Delong; Hsu, Shawn; Pavlidis, Dimitris; Chin, Patrick; Block, Tom

    2002-02-01

    A Ka-band oscillator has been designed, fabricated and tested using InAlAs/InGaAs HBTs. Coplanar waveguide technology has been employed to improve the Q-factor of the circuit. An output power of 2.6 dBm with DC to RF conversion efficiency of 7.8% was measured at 31.7 GHz. Low phase noise of -87 and -112 dBc/Hz were achieved at an offset frequency of 100 kHz and 1 MHz respectively. These low phase noise values can be attributed to the low 1/ f noise of the InAlAs/InGaAs HBT devices and the coplanar design used for the circuit.

  20. Mach-Zehnder Type Annealed Proton Exchange Waveguide and Coplanar Waveguide Modulation Electrode LiNbO3 Intensity Modulator

    Institute of Scientific and Technical Information of China (English)

    HE Jian; ZHU Xue-jun

    2007-01-01

    The characteristics of a conventional LiNbO3 intensity modulator made up of a Mach-Zehnder(MZ) type annealed proton exchange(APE) waveguide and coplanar waveguide(CPW) modulation electrode are presented. The APE waveguide characteristics and their relations with process parameters are analyzed. At the same time, the electrical characteristics of modulation electrode, such as modulation voltage, microwave effective index associated with modulation bandwidth, characteristics impedance, are also investigated in detail.

  1. 8-AminoBODIPYs: cyanines or hemicyanines? The effect of the coplanarity of the amino group on their optical properties.

    Science.gov (United States)

    Osorio-Martínez, Carlos A; Urías-Benavides, Arlette; Gómez-Durán, C F Azael; Bañuelos, Jorge; Esnal, Ixone; López Arbeloa, Iñigo; Peña-Cabrera, Eduardo

    2012-06-15

    The role of the amino group twisting ability in the BODIPY photophysics for nonsterically hindered and constrained molecular structures was studied. When a coplanar disposition of the amino and the BODIPY core is feasible, a hemicyanine-like delocalized π-system gives rise to novel blue and efficient BODIPY laser dyes. The key role of such rotamer is confirmed by newly synthesized derivatives where the amino and the BODIPY core are electronically decoupled by steric repulsions.

  2. Co-sputtered Mo/Re superconducting coplanar resonators compatible with carbon nanotube growth

    Energy Technology Data Exchange (ETDEWEB)

    Blien, Stefan; Stiller, Peter L.; Goetz, Karl; Vavra, Ondrej; Huber, Thomas; Mayer, Thomas; Strunk, Christoph; Huettel, Andreas K. [Institute for Experimental and Applied Physics, University of Regensburg, 93040 Regensburg (Germany)

    2016-07-01

    Carbon nanotubes are simultaneously prototypical single electron tunneling devices and nano-electromechanical resonators. In particular for ''ultraclean'' devices, where the nanotube is grown in a last fabrication step over pre-existing chip structures, highly regular quantum spectra and high mechanical quality factors emerge. Targeting optomechanical experiments, a coupling of these devices to on-chip superconducting coplanar waveguide resonators is highly desirable. The conditions for in-situ growth of carbon nanotubes over metal contacts are quite detrimental to most superconductors: the CVD growth process takes place in a hydrogen/methane atmosphere heated up to 900 {sup circle} C. We present data on transmission line resonators fabricated of a co-sputtered molybdenum rhenium alloy that withstand CVD and remain superconducting with critical temperatures up to 8K after growth. Resonant operation at cryogenic temperatures is demonstrated, and the behaviour is highly consistent with a combination of Mattis-Bardeen theory and two-level systems in the substrate.

  3. Miniature Coplanar Implantable Antenna on Thin and Flexible Platform for Fully Wireless Intracranial Pressure Monitoring System

    Directory of Open Access Journals (Sweden)

    M. Waqas A. Khan

    2017-01-01

    Full Text Available Minimally invasive approach to intracranial pressure monitoring is desired for long-term diagnostics. The monitored pressure is transmitted outside the skull through an implant antenna. We present a new miniature (6 mm × 5 mm coplanar implant antenna and its integration on a sensor platform to establish a far-field data link for the sensor readout at distances of 0.5 to 1 meter. The implant antenna was developed using full-wave electromagnetic simulator and measured in a liquid phantom mimicking the dielectric properties of the human head. It achieved impedance reflection coefficient better than −10 dB from 2.38 GHz to 2.54 GHz which covers the targeted industrial, scientific, and medical band. Experiments resulted in an acceptable peak gain of approximately −23 dBi. The implant antenna was submerged in the liquid phantom and interfaced to a 0.5 mW voltage controlled oscillator. To verify the implant antenna performance as a part of the ICP monitoring system, we recorded the radiated signal strength using a spectrum analyzer. Using a half-wavelength dipole as the receiving antenna, we captured approximately −58.7 dBm signal at a distance of 1 m from the implant antenna which is well above for the reader with sensitivity of −80 dBm.

  4. Multi-frequency spin manipulation using rapidly tunable superconducting coplanar waveguide microresonators

    Science.gov (United States)

    Asfaw, A. T.; Sigillito, A. J.; Tyryshkin, A. M.; Schenkel, T.; Lyon, S. A.

    2017-07-01

    In this work, we demonstrate the use of frequency-tunable superconducting NbTiN coplanar waveguide microresonators for multi-frequency pulsed electron spin resonance (ESR) experiments. By applying a bias current to the center pin, the resonance frequency (˜7.6 GHz) can be continuously tuned by as much as 95 MHz in 270 ns without a change in the quality factor of 3000 at 2 K. We demonstrate the ESR performance of our resonators by measuring donor spin ensembles in silicon and show that adiabatic pulses can be used to overcome magnetic field inhomogeneities and microwave power limitations due to the applied bias current. We take advantage of the rapid tunability of these resonators to manipulate both phosphorus and arsenic spins in a single pulse sequence, demonstrating pulsed double electron-electron resonance. Our NbTiN resonator design is useful for multi-frequency pulsed ESR and should also have applications in experiments where spin ensembles are used as quantum memories.

  5. Underlying Architecture of Planetary Systems Based on Kepler Data: Number of Planets and Coplanarity

    Science.gov (United States)

    Fang, Julia; Margot, J. L.

    2012-10-01

    We investigated the underlying architecture of planetary systems by deriving the distribution of planet multiplicity (number of planets) and the distribution of orbital inclinations based on the sample of planet candidates discovered by the Kepler mission. The scope of our study included solar-like stars and planets with orbital periods less than 200 days and with radii between 1.5 and 30 Earth radii, and was based on Kepler planet candidates detected during Quarters 1 through 6. Our analysis improves on previous work by including all available quarters, extending to 200-day periods, and fitting models to observables such as normalized transit duration ratios that contain information on mutual orbital inclinations; these improvements lend to a deeper investigation of the intrinsic distributions of planetary systems. We created models of planetary systems with different distributions of planet multiplicity and orbital inclinations, simulated observations of these systems by Kepler, and compared the number and properties of the transits of detectable objects to actual Kepler planet detections. Based on the underlying distributions of our best-fit models, 75-80% of planetary systems have 1 or 2 planets with orbital periods less than 200 days. In addition, over 85% of planets have orbital inclinations less than 3 degrees. This high degree of coplanarity is comparable to that seen in our Solar System, with the exception of Mercury. These results provide important constraints and insights into theories of planet formation and evolution.

  6. Formation of striations in large-gap coplanar dielectric barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Xiaofei [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); He, Feng, E-mail: hefeng@bit.edu.cn [School of Physics, Beijing Institute of Technology, Beijing 100081 (China); Ouyang, Jiting [School of Physics, Beijing Institute of Technology, Beijing 100081 (China)

    2012-06-04

    Striations in a large-gap coplanar dielectric barrier discharge (DBD) have been investigated by experiment and numerical simulation. The discharge current was measured and the images of infra-red (IR) radiation striation were obtained by an intensified charge-coupled device (ICCD) camera with nanosecond exposure time. The discharge processes are simulated by particle-in-cell/Monte Carlo collision (PIC/MCC) code. The calculated current and the distribution of Xe{sup ⁎} during a single pulse were compared with the experiment. The results show that there are two series of striations corresponding to two stages of discharge. The striations of the second stage are generated as the potential changed remarkably, while the distribution of surface charge almost keeps unchanged. The electric field induced by the space charges plays a key role in the formation of the striations. The stratified wall charge is only a consequence of the stratified spatial field and the striations. -- Highlights: ► IR radiation images of striations were compared with PIC/MCC simulation results. ► Space charge plays a key role in striation formation. ► Stratified wall charge is considered as a consequence of the striations.

  7. Planar architecture for microstrip interfaced packaging of coplanar-waveguide-based radio frequency microelectromechanical system switches

    Science.gov (United States)

    Singh, Shailendra; Giridhar, Malalahalli Sreenivasamurthy; Rao, Cheemalamarri Venkata Narasimha; Bhalke, Sangam; Islam, Rifqul

    2015-01-01

    This paper describes the architecture of microstrip (MS) interfaced packaging of a coplanar-waveguide (CPW)-based radio frequency microelectromechanical systems (RF MEMS) switch in a hermetic metal-ceramic RF package. The switch is integrated along with CPW to MS (CPW-MS) transitions within the package itself. This makes the MS interfaced packaged switch module readily mountable on MS based RF boards and subsystems. The CPW-MS transition for the package was designed as a separate off-chip entity on an alumina substrate and utilizes via hole. The integrated three-dimensional model of the package consisting of the RF MEMS switch and the transitions was simulated using high frequency structure simulator. The realized module shows an insertion loss of 0.2 and 1.1 dB at 100 MHz and 7 GHz, respectively. The measured isolation is better than 60 dB at 100 MHz and 30 dB at 7 GHz. The return loss is better than 15 dB up to 7 GHz. The estimated packaging and transitioning loss is 0.5 dB at 5 GHz. This packaging architecture is a planar solution for the MS interfaced packaging of CPW based RF MEMS switches for designers who do not have access to high-end technologies, such as zero-level packaging, through silicon via or low temperature co-fired ceramics.

  8. Template-stripped, ultraflat gold surfaces with coplanar, embedded titanium micropatterns.

    Science.gov (United States)

    Venkataraman, Nagaiyanallur V; Pei, Jia; Cremmel, Clément V M; Rossi, Antonella; Spencer, Nicholas D

    2013-08-01

    Ultraflat gold surfaces with coplanar, embedded titanium micropatterns, exhibiting extremely low roughness over the entire surface, have been obtained by a modified template-stripping procedure. Titanium is deposited onto photolithographically predefined regions of a silicon template. Following photoresist lift-off, the entire surface is backfilled with gold, template stripping is conducted, and an ultraflat micropatterned surface is revealed. Atomic force microscopy confirms a roughness of surface-chemical maps of the patterned surfaces have been obtained by means of imaging X-ray photoelectron spectroscopy (i-XPS) as well as time-of-flight secondary-ion mass spectrometry (ToF-SIMS). They confirm the presence of well-separated Ti and Au regions, with a chemical contrast that is sharp (as determined by ToF-SIMS) and complete (as determined by i-XPS) across the Ti-Au interface. Thus, a surface has been fabricated that is physically homogeneous down to the nanoscale incorporating chemically distinct micropatterns consisting of two different metals, with totally contrasting surface chemistries.

  9. Novel Micromachined Coplanar Waveguide Transmission Lines for Application in Millimeter-Wave Circuits

    Science.gov (United States)

    Park, Jae-Hyoung; Baek, Chang-Wook; Jung, Sanghwa; Kim, Hong-Teuk; Kwon, Youngwoo; Kim, Yong-Kweon

    2000-12-01

    In this paper, novel micromachined coplanar waveguide(CPW) transmission lines for application in millimeter-wave circuits are proposed. Two types of transmission lines with the length of 1 cm are fabricated and the measured characteristics are compared with those of the conventional CPW transmission line. One is the elevated CPW(ECPW) transmission line and the other is the overlay CPW(OCPW) line. These transmission lines are composed of 3-μm-thick electroplated gold lines with overhanging parts. By elevating the metal lines from the substrate using micromachining technology, the conductor and substrate dielectric loss can be reduced and easily integrated with conventional monolithic microwave integrated circuits. Compared with the conventional CPW line showing 2.65 dB/cm insertion loss at 50 GHz, the loss can be reduced to 1.9 dB/cm and 1.25 dB/cm at 50 GHz in the case of the ECPW and OCPW transmission lines, respectively. Also, the OCPW transmission line shows that the insertion loss does not vary with the change of the characteristic impedance. As shown in the measured and simulated results, the insertion loss is maintained below 1.4 dB/cm over wide impedance ranges.

  10. Oscillatory motion of water droplets in kerosene above co-planar electrodes in microfluidic chips

    Directory of Open Access Journals (Sweden)

    Pavel Beránek

    2014-06-01

    Full Text Available We experimentally observed oscillatory motion of water droplets in microfluidic systems with coplanar microelectrodes under imposed DC electric fields. Two-electrode arrangement with no bipolar electrode and eight-electrode arrangement with six bipolar microelectrodes were investigated. Kerosene was used as the continuous phase. We studied the dependences of the oscillation frequency on the electric field intensity and ionic strength of the water phase. We found that the electric field dependence is strongly nonlinear and discussed possible reasons of this phenomenon, e.g., the droplet deformation at electrode edges that affects the charge transfer between the electrode and droplet or the interplay between the Coulomb force on free charge and the dielectrophoretic force. Our experiments further revealed that the oscillation frequency decreases with growing salt concentration in the two-electrode arrangement, but increases in the eight-electrode arrangement, which was attributed to surface tension related processes and electrochemical processes on the bipolar electrodes. Finally, we analyzed the effects of the electric field on the oscillatory motion by means of a simplified mathematical model. It was shown that the electric force imposed on the droplet charge is the key factor to induce the oscillations and the dielectrophoretic force significantly contributes to the momentum transfer at the electrode edges. For the same electric field strength, the model is able to predict the same oscillation frequency as that observed in the experiments.

  11. Fluorescence (TALIF) measurement of atomic hydrogen concentration in a coplanar surface dielectric barrier discharge

    Science.gov (United States)

    Mrkvičková, M.; Ráheľ, J.; Dvořák, P.; Trunec, D.; Morávek, T.

    2016-10-01

    Spatially and temporally resolved measurements of atomic hydrogen concentration above the dielectric of coplanar barrier discharge are presented for atmospheric pressure in 2.2% H2/Ar. The measurements were carried out in the afterglow phase by means of two-photon absorption laser-induced fluorescence (TALIF). The difficulties of employing the TALIF technique in close proximity to the dielectric surface wall were successfully addressed by taking measurements on a suitable convexly curved dielectric barrier, and by proper mathematical treatment of parasitic signals from laser-surface interactions. It was found that the maximum atomic hydrogen concentration is situated closest to the dielectric wall from which it gradually decays. The maximum absolute concentration was more than 1022 m-3. In the afterglow phase, the concentration of atomic hydrogen above the dielectric surface stays constant for a considerable time (10 μs-1 ms), with longer times for areas situated farther from the dielectric surface. The existence of such a temporal plateau was explained by the presented 1D model: the recombination losses of atomic hydrogen farther from the dielectric surface are compensated by the diffusion of atomic hydrogen from regions close to the dielectric surface. The fact that a temporal plateau exists even closest to the dielectric surface suggests that the dielectric surface acts as a source of atomic hydrogen in the afterglow phase.

  12. Induction of heme oxygenase-1 by whisky congeners in human endothelial cells.

    Science.gov (United States)

    Suzuki, Keiko; Nemoto, Asuka; Tanaka, Izumi; Koshimizu, Seiichi; Suwa, Yoshihide; Ishihara, Hiroshi

    2010-08-01

    It is expected that the production of the cytoprotective heme oxygenase-1 (HO-1) protein in endothelial cells would reduce severity of vascular injuries, while phenolic compounds are known to induce HO-1 mRNA and protein in various cells. We investigated the activation of HO-1 by whisky, which contains various phenolic substances. The congeners of whisky stored from 4 to 18 y in oak barrels were shown to induce an increase of HO-1 protein in human umbilical vein endothelial cells, while those of freshly distilled whisky spirit exhibited no activity. To determine the compounds with potent HO-1-inducing activity among the whisky congeners, several chemicals that had been reported to exist in whisky or oak barrels were screened, and coniferyl aldehyde and sinapyl aldehyde showed the activity. Thus, compounds that emerged in whisky during barrel storage induced cytoprotective protein, HO-1, in human endothelial cells.

  13. Accumulation and depletion of polychlorinated biphenyl (PCB) congeners in the housefly (musca domestica, L. )

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, L.G. (Univ. of Illinois, Urbana (United States)); Storr-Hansen, E. (National Environmental Research Inst., Soeborg (Denmark))

    1992-01-01

    Polychlorinated biphenyl (PCB) residues in food chains and in the environment are dynamic complex mixtures and there is considerable interest in the disposition as well as toxicities of individual congeners. The persistence and biological activities of PCBs are intimately associated with microsomal monooxygenases. The house fly, Musca domestica (L.), has long been a standard organism for studies of pesticide toxicology and has an active and well-defined microsomal monooxygenase system. These oxidases in the fly can be induced by PCBs. It was considered of interest to provide data which may indicate whether or not the relatively large and mobile biomass of insects in general may play a role in the global disposition of PCBs. It was also of interest to determine if the house fly could serve as a model for determining the relative accumulation, elimination, and toxicities of individual PCB congeners.

  14. Germ-line reinsertions of AKR murine leukemia virus genomes in Akv-1 congenic mice.

    Science.gov (United States)

    Rowe, W P; Kozak, C A

    1980-08-01

    Congenic mouse strains NIH,Akv-1 and NIH,Akv-2 carry the two high ecotropic virus-inducing loci of the AKR mouse on the NIH Swiss genetic background. Progeny tests of animals in three separate congenic families show that both Avk-1 and Akv-2 are stably transmitted as classical mendelian loci in these mice. However, during the process of inbreeding, additional chromosomal viral loci were detected in several NIH.Akv-1 sublines. These loci appeared only in the progeny of virus-positive females. They segregate with mendelian ratios, are unlinked to markers on chromsome 7 near Akv-1, and are phenotypically expressed as high-virus-inducing loci. The generation of new loci for viurs induction, no doubt resulting from the rare germ-line reintegration of the endogenous ectropic provirus, represents a unique form of gene duplication and rearrangement.

  15. Polychlorinated biphenyls and breast cancer: A congener-specific meta-analysis.

    Science.gov (United States)

    Leng, Ling; Li, Jing; Luo, Xiu-mei; Kim, Jun-young; Li, Yi-meng; Guo, Xue-mei; Chen, Xi; Yang, Qiao-yun; Li, Guang; Tang, Nai-jun

    2016-03-01

    The incidence of breast cancer is related to various risk factors, especially that the environmental and lifestyle factors account for major contribution at the rate of 70% to 95% over all. However, there still remains some controversy over the epidemiological evidence regarding the effects of environmental carcinogens on the risk of breast cancer. We conducted a quantitative meta-analysis aiming at full evaluation of the effects of polychlorinated biphenyls (PCBs) on breast cancer in a congener-specific fashion. Four online literature databases were systematically searched before 1st January 2015, for studies stating correlation between PCB congeners and breast cancer. The Newcastle-Ottawa Scale was used to evaluate the quality of the studies that were included in our analysis. Sixteen studies were included in our final meta-analysis after screening based on the priori inclusion criteria. Nine PCB congeners were reported by more than two studies and they were presented in detail. The pooled Odds Ratios (ORs) showed a significant increase in the risk of breast cancer in individuals with higher plasma/fat levels of PCB 99 (OR: 1.36; 95% CI: 1.02 to 1.80), PCB 183 (OR: 1.56; 95% CI: 1.25 to 1.95) and PCB 187 (OR: 1.18; 95% CI: 1.01 to 1.39). Besides, the outcomes did not support a relationship between dioxin-like PCB congeners and the risk of breast cancer. The results of our meta-analysis imply that PCB 99, PCB 183 and PCB 187 would increase the risk of breast cancer. The mechanism of this increased risk may be by the induction of the CYP2B family in cytochrome P450 enzymes.

  16. Congenic Mesenchymal Stem Cell Therapy Reverses Hyperglycemia in Experimental Type 1 Diabetes

    OpenAIRE

    2010-01-01

    OBJECTIVE A number of clinical trials are underway to test whether mesenchymal stem cells (MSCs) are effective in treating various diseases, including type 1 diabetes. Although this cell therapy holds great promise, the optimal source of MSCs has yet to be determined with respect to major histocompatibility complex matching. Here, we examine this question by testing the ability of congenic MSCs, obtained from the NOR mouse strain, to reverse recent-onset type 1 diabetes in NOD mice, as well a...

  17. Synthesis and antiprotozoal properties of pentamidine congeners bearing the benzofuran motif.

    Science.gov (United States)

    Bakunov, Stanislav A; Bakunova, Svetlana M; Bridges, Arlene S; Wenzler, Tanja; Barszcz, Todd; Werbovetz, Karl A; Brun, Reto; Tidwell, Richard R

    2009-09-24

    Forty-eight cationically substituted pentamidine congeners possessing benzofuran rings were synthesized by a copper mediated heteroannulation of substituted o-iodophenols with phenyl acetylenes. Activities of compounds 1-48 against Trypanosoma brucei rhodesiense, Plasmodium falciparum, and Leishmania donovani and cytotoxicities for mammalian cells were influenced by the nature of cationic substituents, placement of the benzofuran fragment, and the length of the carbon linker between aromatic moieties. Several dications exhibited superior antiplasmodial and antileishmanial potencies compared to pentamidine.

  18. Occurrence and congeners specific of polychlorinated biphenyls in agricultural soils from Southern Jiangsu, China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jian-ying; QIU Li-min; HE Jia; LIAO Yuan; LUO Yong-ming

    2007-01-01

    A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls(PCBs)in order to assess the levels of pollution,sources,area distribution,and potential risk for the environment.All methods were rigorously tested and an adequate quality control was ensured.Only one site had no PCBs residues,and the highest total PCBs concentration in the surface soils was 32.83 ng/g.The average concentration in all the soil samples was 4.13ng/g.signaling low-level pollution.Tetra-,penta-,and hexa-chlorinated biphenyls were dominant speoes in soil samples,accounnng for more than 75%of ΣPCBs in the soil samples.PCB118 was the most abundant congener in all the samples.The PCB118 Was about 20%of ΣPCBs.The soil organic matter content showed only a weak correlation with the levels of all PCB congeners,in which a better correlation was noted for the more volatile lighter PCB congeners than for the heavier homologues.To a certain extent,the sources and land use seemed to influence the levels of PCBs.

  19. Congenic mice reveal genetic epistasis and overlapping disease loci for autoimmune diabetes and listeriosis.

    Science.gov (United States)

    Wang, Nancy; Elso, Colleen M; Mackin, Leanne; Mannering, Stuart I; Strugnell, Richard A; Wijburg, Odilia L; Brodnicki, Thomas C

    2014-08-01

    The nonobese diabetic (NOD) mouse strain serves as a genomic standard for assessing how allelic variation for insulin-dependent diabetes (Idd) loci affects the development of autoimmune diabetes. We previously demonstrated that C57BL/6 (B6) mice harbor a more diabetogenic allele than NOD mice for the Idd14 locus when introduced onto the NOD genetic background. New congenic NOD mouse strains, harboring smaller B6-derived intervals on chromosome 13, now localize Idd14 to an ~18-Mb interval and reveal a new locus, Idd31. Notably, the B6 allele for Idd31 confers protection against diabetes, but only in the absence of the diabetogenic B6 allele for Idd14, indicating genetic epistasis between these two loci. Moreover, congenic mice that are more susceptible to diabetes are more resistant to Listeria monocytogenes infection. This result co-localizes Idd14 and Listr2, a resistance locus for listeriosis, to the same genomic interval and indicates that congenic NOD mice may also be useful for localizing resistance loci for infectious disease.

  20. An invasive plant alters phenotypic selection on the vegetative growth of a native congener.

    Science.gov (United States)

    Beans, Carolyn M; Roach, Deborah A

    2015-02-01

    The ecological consequences of plant competition have frequently been tested, but the evolutionary outcomes of these interactions have gone largely unexplored. The study of species invasions can make an important contribution to this field of research by allowing us to watch ecological and evolutionary processes unfold as a novel species is integrated into a plant community. We explored the ecological and evolutionary impact of an invasive jewelweed, Impatiens glandulifera, on a closely related native congener, I. capensis and asked: (1) Does the presence of the invasive jewelweed alter the fitness of native jewelweed populations? (2) Does the invasive jewelweed affect the vegetative growth of the native congener? and (3) Does the invasive jewelweed alter phenotypic selection on the vegetative traits of the native congener? We used a greenhouse competition experiment, an invasive species removal field experiment, and a survey of natural populations. We show that when the invasive jewelweed is present, phenotypic selection favors native jewelweed individuals investing less in rapid upward growth and more in branching and fruiting potential through the production of nodes. This research demonstrates that invasive plants have the potential to greatly alter natural selection on native competitors. Studies investigating altered selection in invaded communities can reveal the potential evolutionary impact of invasive competitors, while deepening our understanding of the more general role of competition in driving plant evolution and permitting species coexistence. © 2015 Botanical Society of America, Inc.

  1. Analysis of six relevant toxaphene congeners in biological samples using ion trap MS/MS.

    Science.gov (United States)

    Gouteux, Bruno; Lebeuf, Michel; Trottier, Steve; Gagné, Jean-Pierre

    2002-10-01

    The quantification of six polychlorinated bornanes (CHBs) was studied using ion trap MS/MS. The significance of the selection of parent ions (Ip) and daughter ions (Id) on the detection of these toxaphene congeners was assessed in standard solution and biological samples. Our results indicate that different Ip and Id, selected at either low or high mass-to-charge (m/z) ratios, influence drastically the response factor of the CHBs and the chemical noise observed. For the octachlorinated toxaphene congeners (Parlar-26 (P-26), Parlar-40/41 (P-40/41), Parlar-44 (P-44)), the detection performance of the ion trap MS/MS is similar whether Ip and Id were chosen at low or high m/z ratios. However, the selection of Ip and Id at high m/z ratios clearly enhances the detection of the nonachlorinated toxaphene congeners (Parlar-50 (P-50), Parlar-62 (P-62)). The improved method, which selects Ip and Id at low m/z ratios for P-26, P-40/41 and P-44 and at high m/z ratios for P-50 and P-62, permitted to obtain low detection limits as well as repeatable and accurate results.

  2. Monodomain dynamics for rigid rod and platelet suspensions in strongly coupled coplanar linear flow and magnetic fields. II. Kinetic theory

    Science.gov (United States)

    Forest, M. Gregory; Sircar, Sarthok; Wang, Qi; Zhou, Ruhai

    2006-10-01

    We establish reciprocity relations of the Doi-Hess kinetic theory for rigid rod macromolecular suspensions governed by the strong coupling among an excluded volume potential, linear flow, and a magnetic field. The relation provides a reduction of the flow and field driven Smoluchowski equation: from five parameters for coplanar linear flows and magnetic field, to two field parameters. The reduced model distinguishes flows with a rotational component, which map to simple shear (with rate parameter) subject to a transverse magnetic field (with strength parameter), and irrotational flows, for which the reduced model consists of a triaxial extensional flow (with two extensional rate parameters). We solve the Smoluchowski equation of the reduced model to explore: (i) the effect of introducing a coplanar magnetic field on each sheared monodomain attractor of the Doi-Hess kinetic theory and (ii) the coupling of coplanar extensional flow and magnetic fields. For (i), we show each sheared attractor (steady and unsteady, with peak axis in and out of the shearing plane, periodic and chaotic orbits) undergoes its own transition sequence versus magnetic field strength. Nonetheless, robust predictions emerge: out-of-plane degrees of freedom are arrested with increasing field strength, and a unique flow-aligning or tumbling/wagging limit cycle emerges above a threshold magnetic field strength or modified geometry parameter value. For (ii), irrotational flows coupled with a coplanar magnetic field yield only steady states. We characterize all (generically biaxial) equilibria in terms of an explicit Boltzmann distribution, providing a natural generalization of analytical results on pure nematic equilibria [P. Constantin, I. Kevrekidis, and E. S. Titi, Arch. Rat. Mech. Anal. 174, 365 (2004); P. Constantin, I. Kevrekidis, and E. S. Titi, Discrete and Continuous Dynamical Systems 11, 101 (2004); P. Constantin and J. Vukadinovic, Nonlinearity 18, 441 (2005); H. Liu, H. Zhang, and P

  3. Dechlorination of the dietary nona-chlorinated toxaphene congeners 62 and 50 into the octa-chlorinated toxaphene congeners 44 and 40 in zebrafish (Danio rerio) and Atlantic salmon (Salmo salar)

    Energy Technology Data Exchange (ETDEWEB)

    Berntssen, M.H.G., E-mail: marc.berntssen@nifes.no [National Institute of Nutrition and Seafood Research (NIFES), Postbox 2029 Nordnes, 5817 Bergen (Norway); Lundebye, A.-K.; Hop-Johannessen, L.; Lock, E.-J. [National Institute of Nutrition and Seafood Research (NIFES), Postbox 2029 Nordnes, 5817 Bergen (Norway)

    2012-05-15

    Graphical abstract: - Abstract: The relative feed-to-fish accumulation and possible biotransformation of the nona-chlorinated toxaphene congeners currently included in EU-legislation (CHB-50 and -62) and the octa-chlorinated congeners recommended by the European Food Safety Authority to be included in future surveillance of fish samples (CHB-40, 41, and 44) were investigated in the present study. Model fish Danio rerio were fed either (a) diets spiked with a combination as well as the pure individual toxaphene congeners CHB-50 or 62 or (b) diets spiked with the combination of CHB N-Ary-Summation 50 + 62 and/or CHB N-Ary-Summation 40 + 41 + 44. In addition, seawater adapted Atlantic salmon smolts were fed technical toxaphene enriched feeds for 62 days. Zebrafish fed a diet containing CHB-50 and CHB-62 accumulated newly formed CHB-40 and 41 and CHB-44, respectively. The biomagnifications factors (BMF) of the toxaphene congeners in Atlantic salmon muscle from the feeds spiked with technical toxaphene were significantly correlated with their relative lipophilicity (expressed as log K{sub ow}). An exception was CHB-44 which had a higher BMF than could be expected from its specific log K{sub ow}, reflecting that CHB-44 is a metabolite formed under dietary exposure to CHB-62. This paper reports the in vivo dechlorination of nona-chlorinated toxaphene congeners into octa-chlorinated congeners in feeding trials with a model fish (zebrafish) and an oily food fish (Atlantic salmon).

  4. Dechlorination of the dietary nona-chlorinated toxaphene congeners 62 and 50 into the octa-chlorinated toxaphene congeners 44 and 40 in zebrafish (Danio rerio) and Atlantic salmon (Salmo salar).

    Science.gov (United States)

    Berntssen, M H G; Lundebye, A-K; Hop-Johannessen, L; Lock, E-J

    2012-05-15

    The relative feed-to-fish accumulation and possible biotransformation of the nona-chlorinated toxaphene congeners currently included in EU-legislation (CHB-50 and -62) and the octa-chlorinated congeners recommended by the European Food Safety Authority to be included in future surveillance of fish samples (CHB-40, 41, and 44) were investigated in the present study. Model fish Danio rerio were fed either (a) diets spiked with a combination as well as the pure individual toxaphene congeners CHB-50 or 62 or (b) diets spiked with the combination of CHB ∑50+62 and/or CHB ∑40+41+44. In addition, seawater adapted Atlantic salmon smolts were fed technical toxaphene enriched feeds for 62 days. Zebrafish fed a diet containing CHB-50 and CHB-62 accumulated newly formed CHB-40&41 and CHB-44, respectively. The biomagnifications factors (BMF) of the toxaphene congeners in Atlantic salmon muscle from the feeds spiked with technical toxaphene were significantly correlated with their relative lipophilicity (expressed as logK(ow)). An exception was CHB-44 which had a higher BMF than could be expected from its specific logK(ow), reflecting that CHB-44 is a metabolite formed under dietary exposure to CHB-62. This paper reports the in vivo dechlorination of nona-chlorinated toxaphene congeners into octa-chlorinated congeners in feeding trials with a model fish (zebrafish) and an oily food fish (Atlantic salmon).

  5. Distinguishing PCB Isomeric Congeners with their Gas Chromatographic and Mass Spectrometric Ortho Effect using Comprehensive Gas Chromatography

    Science.gov (United States)

    The 209 polychlorinated biphenyl (PCB) congeners and associated nine isomeric groups (nine groups of PCBs with the same degree of chlorination) have been long recorded as high endocrine disrupting chemicals in the environment. Difficult analytical problems exist, in those frequen...

  6. Beam’s-eye-view imaging during non-coplanar lung SBRT

    Energy Technology Data Exchange (ETDEWEB)

    Yip, Stephen S. F., E-mail: syip@lroc.harvard.edu; Rottmann, Joerg; Berbeco, Ross I. [Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, Massachusetts 02115 (United States)

    2015-12-15

    Purpose: Beam’s-eye-view (BEV) imaging with an electronic portal imaging device (EPID) can be performed during lung stereotactic body radiation therapy (SBRT) to monitor the tumor location in real-time. Image quality for each patient and treatment field depends on several factors including the patient anatomy and the gantry and couch angles. The authors investigated the angular dependence of automatic tumor localization during non-coplanar lung SBRT delivery. Methods: All images were acquired at a frame rate of 12 Hz with an amorphous silicon EPID. A previously validated markerless lung tumor localization algorithm was employed with manual localization as the reference. From ten SBRT patients, 12 987 image frames of 123 image sequences acquired at 48 different gantry–couch rotations were analyzed. δ was defined by the position difference of the automatic and manual localization. Results: Regardless of the couch angle, the best tracking performance was found in image sequences with a gantry angle within 20° of 250° (δ = 1.40 mm). Image sequences acquired with gantry angles of 150°, 210°, and 350° also led to good tracking performances with δ = 1.77–2.00 mm. Overall, the couch angle was not correlated with the tracking results. Among all the gantry–couch combinations, image sequences acquired at (θ = 30°, ϕ = 330°), (θ = 210°, ϕ = 10°), and (θ = 250°, ϕ = 30°) led to the best tracking results with δ = 1.19–1.82 mm. The worst performing combinations were (θ = 90° and 230°, ϕ = 10°) and (θ = 270°, ϕ = 30°) with δ > 3.5 mm. However, 35% (17/48) of the gantry–couch rotations demonstrated substantial variability in tracking performances between patients. For example, the field angle (θ = 70°, ϕ = 10°) was acquired for five patients. While the tracking errors were ≤1.98 mm for three patients, poor performance was found for the other two patients with δ ≥ 2.18 mm, leading to average tracking error of 2.70 mm. Only one

  7. Mammalian Cytochrome P450-Dependent Metabolism of Polychlorinated Dibenzo-p-dioxins and Coplanar Polychlorinated Biphenyls

    Directory of Open Access Journals (Sweden)

    Hideyuki Inui

    2014-08-01

    Full Text Available Polychlorinated dibenzo-p-dioxins (PCDDs and coplanar polychlorinated biphenyls (PCBs contribute to dioxin toxicity in humans and wildlife after bioaccumulation through the food chain from the environment. The authors examined human and rat cytochrome P450 (CYP-dependent metabolism of PCDDs and PCBs. A number of human CYP isoforms belonging to the CYP1 and CYP2 families showed remarkable activities toward low-chlorinated PCDDs. In particular, human CYP1A1, CYP1A2, and CYP1B1 showed high activities toward monoCDDs, diCDDs, and triCDDs but no detectable activity toward 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-tetraCDD. Large amino acids located at putative substrate-recognition sites and the F-G loop in rat CYP1A1 contributed to the successful metabolism of 2,3,7,8-tetraCDD. Rat, but not human, CYP1A1 metabolized 3,3',4,4',5-pentachlorobiphenyl (CB126 to two hydroxylated metabolites. These metabolites are probably less toxic than is CB126, due to their higher solubility. Homology models of human and rat CYP1A1s and CB126 docking studies indicated that two amino acid differences in the CB126-binding cavity were important for CB126 metabolism. In this review, the importance of CYPs in the metabolism of dioxins and PCBs in mammals and the species-based differences between humans and rats are described. In addition, the authors reveal the molecular mechanism behind the binding modes of dioxins and PCBs in the heme pocket of CYPs.

  8. Mammalian cytochrome P450-dependent metabolism of polychlorinated dibenzo-p-dioxins and coplanar polychlorinated biphenyls.

    Science.gov (United States)

    Inui, Hideyuki; Itoh, Toshimasa; Yamamoto, Keiko; Ikushiro, Shin-Ichi; Sakaki, Toshiyuki

    2014-08-13

    Polychlorinated dibenzo-p-dioxins (PCDDs) and coplanar polychlorinated biphenyls (PCBs) contribute to dioxin toxicity in humans and wildlife after bioaccumulation through the food chain from the environment. The authors examined human and rat cytochrome P450 (CYP)-dependent metabolism of PCDDs and PCBs. A number of human CYP isoforms belonging to the CYP1 and CYP2 families showed remarkable activities toward low-chlorinated PCDDs. In particular, human CYP1A1, CYP1A2, and CYP1B1 showed high activities toward monoCDDs, diCDDs, and triCDDs but no detectable activity toward 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-tetraCDD). Large amino acids located at putative substrate-recognition sites and the F-G loop in rat CYP1A1 contributed to the successful metabolism of 2,3,7,8-tetraCDD. Rat, but not human, CYP1A1 metabolized 3,3',4,4',5-pentachlorobiphenyl (CB126) to two hydroxylated metabolites. These metabolites are probably less toxic than is CB126, due to their higher solubility. Homology models of human and rat CYP1A1s and CB126 docking studies indicated that two amino acid differences in the CB126-binding cavity were important for CB126 metabolism. In this review, the importance of CYPs in the metabolism of dioxins and PCBs in mammals and the species-based differences between humans and rats are described. In addition, the authors reveal the molecular mechanism behind the binding modes of dioxins and PCBs in the heme pocket of CYPs.

  9. High levels of structural diversity observed in microcystins from Microcystis CAWBG11 and characterization of six new microcystin congeners.

    Science.gov (United States)

    Puddick, Jonathan; Prinsep, Michèle R; Wood, Susanna A; Kaufononga, Sangata A F; Cary, Stephen Craig; Hamilton, David P

    2014-11-13

    Microcystins (MCs) are cyclic peptides produced by cyanobacteria, which can be harmful to humans and animals when ingested. Differences in the coding of the non‑ribosomal peptide synthetase/polyketide synthase enzyme complex responsible for microcystin production have resulted in more than 100 microcystin variants being reported to date. The microcystin diversity of Microcystis CAWBG11 was investigated using matrix-assisted laser desorption/ionization-time of flight mass spectrometry and liquid chromatography-mass spectrometry. This revealed that CAWBG11 simultaneously produced 21 known microcystins and six new congeners: [Asp3] MC-RA, [Asp3] MC-RAba, [Asp3] MC-FA, [Asp3] MC-WA, MC-FAba and MC-FL. The new congeners were putatively characterized by tandem mass spectrometry and chemical derivatization. A survey of the microcystin congeners produced by 49 cyanobacterial strains documented in scientific literature showed that cyanobacteria generally produce four microcystin congeners, but strains which produce up to 47 microcystin congeners have been reported. Microcystis CAWBG11 (which produces at least 27 congeners) was positioned in the top ten percentile of the strains surveyed, and showed fluidity of the amino acids incorporated into both position two and position four.

  10. Coplanar VMAT vs. noncoplanar VMAT in the treatment of sinonasal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Zhong-Hua; Mu, Jin-Ming; Mo, Jun-Chong; Gao, Ming; Li, Qi-Lin; Gu, Wen-Dong; Pei, Hong-Lei [The Third Affiliated Hospital, Soochow University, Department of Radiation Oncology, Changzhou (China); Jiang, Jing-Ting; Li, Xiao-Dong; Chen, Lu-Jun [The Third Affiliated Hospital, Soochow University, Department of Tumor Biological Treatment, Changzhou (China); Jin, Jian-Xue [Elekta China Co. Ltd, Department of Radiation Physics, Beijing, Chaoyang District (China)

    2014-10-08

    Previous studies showed that noncoplanar intensity-modulated radiotherapy (NC-IMRT) for sinonasal cancer is superior to coplanar intensity-modulated radiotherapy (IMRT). Volumetric-modulated arc therapy (VMAT) is a newly introduced treatment modality, and the performance of noncoplanar VMAT for sinonasal cancer has not been well described to date. To compare the dosimetry difference of noncoplanar VMAT (NC-VMAT), coplanar VMAT (co-VMAT), and NC-IMRT for sinonasal cancer. Ten postoperative patients with sinonasal cancer were randomly selected for planning with NC-VMAT, co-VMAT, and NC-IMRT. Two planning target volumes (PTVs) were contoured representing high-risk and low-risk regions set to receive a median absorbed dose (D{sub 50} {sub %}) of 68 Gy and 59 Gy, respectively. The homogeneity index (HI), conformity index (CI), dose-volume histograms (DVHs), and delivery efficiency were all evaluated. Both NC-VMAT and co-VMAT showed superior dose homogeneity and conformity in PTVs compared with NC-IMRT. There was no significant difference between NC-VMAT and co-VMAT in PTV coverage. Both VMAT plans provided a better protection for organs at risk (OARs) than NC-IMRT plans, and NC-VMAT showed a small improvement over co-VMAT in sparing of OARs. For peripheral doses, the doses to breast, thyroid, and larynx in the NC-IMRT plans were significantly higher than those in both VMAT plans. Compared to NC-VMAT, co-VMAT significantly reduced peripheral doses. NC-VMAT and co-VMAT reduced the average delivery time by 63.2 and 64.2 %, respectively, in comparison with NC-IMRT. No differences in delivery efficiency were observed between the two VMAT plans. Compared to NC-VMAT, co-VMAT showed similar PTV coverage and comparable OAR sparing but significantly reduced peripheral doses and positioning uncertainty. We propose to give priority to coplanar VMAT in the treatment of sinonasal cancer. (orig.) [German] Fruehere Studien zeigten, dass die nichtkoplanare intensive modulierte

  11. Estimated PBDE and PBB Congeners in soil from an electronics waste disposal site.

    Science.gov (United States)

    Wang, H-M; Yu, Y-J; Han, M; Yang, S-W; Li, Q; Yang, Y

    2009-12-01

    This study estimated PBDE and PBB congener emissions into the environment from three different e-waste disposal sites that consisted of rude broilers (RB), acid baths (AB) and end-up dumps (ED). Different PBDE and PBB congener profiles were analyzed, and some of their emission sources were discussed. For the examined sites, the levels of SigmaPBB and SigmaPBDE were highest at ED (SigmaPBB 1943.86 ng/g, dw; SigmaPBDE 990.87 ng/g, dw), followed by RB (SigmaPBB 704.58 ng/g, dw; SigmaPBDE 799.27 ng/g, dw) and finally AB (SigmaPBB 108.78 ng/g, dw; SigmaPBDE 171.18 ng/g, dw). PBE-209 (AB 48.67 ng/g, 28.43%; RB 160.23 ng/g, 20.05%; ED 234.12 ng/g, 23.63%) and PBE-203 (AB 51.23 ng/g, 29.93%; RB 130.34 ng/g, 16.31%; ED 93.41 ng/g, 9.43%) exhibited the highest concentrations when compared to the other congeners. Furthermore, high levels of deca-BDE (BDE-209) were observed in AB (48.67 ng/g, 28.43%) and RB sites (160.23 ng/g, 20.05%), which was in accordance with the large amount of these materials in electronics products in China.

  12. Levels of toxaphene congeners in white whales (Delphinapterus leucas) from Svalbard, Norway.

    Science.gov (United States)

    Andersen, G; Føreid, S; Skaare, J U; Jenssen, B M; Lydersen, C; Kovacs, K M

    2006-03-15

    This study reports concentrations of three pesticide toxaphene congeners (CHBs; CHB-26, -50 and -62) from the blubber of ten adult, male white whales (Delphinapterus leucas) from Svalbard, Norway. The CHB congeners that occurred at the highest levels in the blubber of the white whales were, as expected, CHB-26 (4636+/-1992 (SD) ng/g l.w.) and CHB-50 (6579+/-2214 ng/g l.w.); CHB-62 (232+/-231 ng/g l.w.) was also present, but at much lower concentrations. The mean level of the sum of the three CHBs (SigmaCHBs = 11,447+/-4208 ng/g l.w.) in this study is more than twice the mean concentrations of the well-known organochlorine (OC) pollutants SigmaDDTs (sum of pp'-DDT, pp'-DDE, pp'-DDD) and SigmaPCBs (sum of 27 PCB congeners) previously reported from the same individual white whales. The concentrations of CHBs in white whales from Svalbard are at the high end of the range for concentrations of these compounds compared to other Arctic white whale populations. Additionally, the contribution of CHBs to the overall OC burden is larger in white whales from Svalbard compared with their counterparts from other areas in the Arctic. Male white whales from Svalbard have several orders of magnitude higher concentrations of SigmaCHBs compared to seals and polar bears (Ursus maritimus) from the same area. The high levels of CHBs in these whales, and their dominance in the OC pattern, suggests that white whales in Svalbard are exposed to high levels of this group of contaminants. Further studies are needed to investigate possible effects of CHBs and other OC contaminants on the white whale population in Svalbard.

  13. Introducing DartMouse: The Mouse Speed Congenic Facility at Dartmouth Medical School

    Science.gov (United States)

    Trask, H.; Tomlinson, C.; Fiering, S.; Gorham, J.D.; Muirhead, K.

    2010-01-01

    CF-9 DartMouse™ is the Mouse Speed Congenic Facility at Dartmouth Medical School. Use of DartMouse allows for the rapid introgression of modified genes onto any inbred strain of mouse. Speed congenic strains of mice are achievable in 5 generations (1 to 1.5 years), versus 10 generations (∼3 years) required by conventional back-crossing. The application of DartMouse services saves both money and time for researchers using the laboratory mouse for any number of pre-clinical disease models. DartMouse is a complete service facility that works closely with clients at and outside of Dartmouth, helping to design appropriate breeding schemes to optimize back-crossing speed and efficiency. Clients supply mouse tail snips. DartMouse isolates genomic DNA, performs and analyzes complete genome-wide scans, and returns data in graphical and spreadsheet formats. DartMouse discusses results with clients and makes specific recommendations on breeder selection. DartMouse uses “SNP-Chip” technology on an Illumina BeadStation 500 Platform. Chips use a 377 SNP array covering the mouse genome with an average interval density of <7 cM. Turnaround time from receipt of tails to results is typically <2 weeks. One of DartMouse's most popular services is the “background check” in which the genetic background of supposedly fully back-crossed mice can be thoroughly assessed across all chromosomes. DartMouse was inaugurated in the summer of 2008, and received ARRA-funding in the fall of 2009. Our plans are to make DartMouse a regional and national core facility for the generation of speed congenic mice and for the verification of genetic background for conventionally back-crossed mice.

  14. Lack of effects of a "sobering" product, "Eezup!", on the blood ethanol and congener alcohol concentration.

    Science.gov (United States)

    Wunder, Cora; Hain, Sarah; Koelzer, Sarah C; Paulke, Alexander; Verhoff, Marcel A; Toennes, Stefan W

    2017-09-01

    The lifestyle product 'Eezup!' appeared on the German market and promised to normalize energy metabolism. Among vitamins (B1, B2, B6, C, E and zinc), rice protein and fructose the addition of alcohol dehydrogenase and catalase enzymes is a novel approach. The product was advertised as capable of boosting the rate of alcohol elimination. Seventeen subjects (11 men, 6 women, 19-58 years old), participated in a two-way crossover drinking study. Unfiltered wheat beer (4.4g% alcohol content) was drank within one hour to reach blood alcohol concentrations of 1‰ (1g/kg whole blood). On one day "Eezup!" was taken according to the manufacturer's instructions before and after drinking which was substituted for a placebo on the second test day. Blood samples were taken during 9h and ethanol and congener alcohols were determined. A comparison of Cmax, tmax, area under the curve (AUC) for ethanol and congener alcohols, and the hourly elimination rate of ethanol (β60) was performed to investigate an effect of Eezup!. Ethanol concentrations (Cmax) were in the range of 0,63-1,00‰ (median 0,85‰) and 0.62-1.22‰ (median 0.84‰) in the placebo and "Eezup!" condition, respectively, and not statistically different. Also tmax (1-2.5h) and AUCs did not differ. The ethanol elimination rates were 0.16‰/h (0.14-0.19‰/h) and 0.17‰/h (0.14-0.22 ‰/h) in the placebo and "Eezup!" condition without significant difference. The pharmacokinetic parameters of the congener alcohols (1-propanol, isobutanol, 3-methyl-1-butanol, 2-methyl-1-butanol) as well as of methanol did also not differ. The results of the present study failed to show any effect of the sobering product "Eezup!" on the amount of ethanol and congener alcohols absorbed (Cmax, tmax, AUC) and on the ethanol elimination rate (β60). Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Congener Specific Analysis of Polychlorinated Biphenyls (PCBs) in Human Blood Serum from Croatia

    OpenAIRE

    Krauthacker, Blanka; Reiner, Elsa

    2000-01-01

    A gas-chromatographic method on capillary columns is described for measuring concentrations of total PCBs and of six PCB congeners, PCB-28, PCB-52, PCB-101, PCB-138, PCB-153 and PCB-180, in human blood serum. Recovery of compounds was evaluated, and the repeatability and reproducibility of the results tested on samples analysed on the same day and over a period of two years. The method was verified in an international AQA Study in three rounds of measurements. The method was applied for the a...

  16. New GLC analysis of urushiol congeners in different plant parts of poison ivy, Toxicodendron radicans.

    Science.gov (United States)

    Craig, J C; Waller, C W; Billets, S; Elsohly, M A

    1978-04-01

    Methods are presented for the direct GLC analysis of the catechol C15 alkenyl side-chain congeners contained in the urushiol fraction of poison ivy (Toxicodendron radicans) and the C17 homologs of poison oak (Toxicodendron diversilobum). A number of liquid phases were investigated and demonstrated varying degrees of separation. The methods developed were applied to the analysis of the urushiol fractions obtained from different plant parts of poison ivy. The effects of extraction before and after drying demonstrated tht a larger percentage of urushiol was obtained when the fresh plant material was extracted with ethanol.

  17. Symmetry and coplanarity of organic molecules affect their packing and photovoltaic properties in solution-processed solar cells.

    Science.gov (United States)

    Lan, Shang-Che; Raghunath, Putikam; Lu, Yueh-Hsin; Wang, Yi-Chien; Lin, Shu-Wei; Liu, Chih-Ming; Jiang, Jian-Ming; Lin, Ming-Chang; Wei, Kung-Hwa

    2014-06-25

    In this study we synthesized three acceptor-donor-acceptor (A-D-A) organic molecules, TB3t-BT, TB3t-BTT, and TB3t-BDT, comprising 2,2'-bithiophene (BT), benzo[1,2-b:3,4-b':5,6-d″]trithiophene (BTT), and benzo[1,2-b;4,5-b']dithiophene (BDT) units, respectively, as central cores (donors), terthiophene (3t) as π-conjugated spacers, and thiobarbituric acid (TB) units as acceptors. These molecules display different degrees of coplanarity as evidenced by the differences in dihedral angles calculated from density functional theory. By using differential scanning calorimetry and X-ray diffractions for probing their crystallization characteristics and molecular packing in active layers, we found that the symmetry and coplanarity of molecules would significantly affect the melting/crystallization behavior and the formation of crystalline domains in the blend film with fullerene, PC61BM. TB3t-BT and TB3t-BDT, which each possess an inversion center and display high crystallinity in their pristine state, but they have different driving forces in crystallization, presumably because of different degrees of coplanarity. On the other hand, the asymmetrical TB3t-BTT behaved as an amorphous material even though it possesses a coplanar structure. Among our tested systems, the device comprising as-spun TB3t-BDT/PC61BM (6:4, w/w) active layer featured crystalline domains and displayed the highest power conversion efficiency (PCE) of 4.1%. In contrast, the as-spun TB3t-BT/PC61BM (6:4, w/w) active layer showed well-mixed morphology and with a device PCE of 0.2%; it increased to 3.9% after annealing the active layer at 150 °C for 15 min. As for TB3t-BTT, it required a higher content of fullerene in the TB3t-BTT/PC61BM (4:6, w/w) active layer to optimize its device PCE to 1.6%.

  18. Theoretical calculation of triple differential cross sections of 3s orbital of argon in coplanar symmetric (e, 2e) reaction

    Institute of Scientific and Technical Information of China (English)

    Wu Xing-Ju; Chen Xiang-Jun; Shan Xu; Chen Li-Qing; Xu Ke-Zun

    2004-01-01

    The triple differential cross section for the low-energy electron impact ionization of inner-valence 3s orbital of argon has been calculated using the modified distorted wave Born approximation in coplanar symmetric energy-sharing geometry. Satisfactory agreement between theory and experiment is achieved when the polarization and post-collisional interaction (PCI) are included in the calculations. It is shown that the polarization and PCI effects play a very important role in the case of argon at low incident energies.

  19. Fabrication and characterization of a co-planar detector in diamond for low energy single ion implantation

    Science.gov (United States)

    Abraham, J. B. S.; Aguirre, B. A.; Pacheco, J. L.; Vizkelethy, G.; Bielejec, E.

    2016-08-01

    We demonstrate low energy single ion detection using a co-planar detector fabricated on a diamond substrate and characterized by ion beam induced charge collection. Histograms are taken with low fluence ion pulses illustrating quantized ion detection down to a single ion with a signal-to-noise ratio of approximately 10. We anticipate that this detection technique can serve as a basis to optimize the yield of single color centers in diamond. The ability to count ions into a diamond substrate is expected to reduce the uncertainty in the yield of color center formation by removing Poisson statistics from the implantation process.

  20. Design and performance evaluation of a coplanar multimodality scanner for rodent imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lage, E; Vaquero, J J; Sisniega, A; Tapias, G; Abella, M; Rodriguez-Ruano, A; Desco, M [Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Espana, S [Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense, Madrid (Spain); Ortuno, J E [Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Zaragoza (Spain); Udias, A [Departamento de Estadistica e Investigacion Operativa, Universidad Rey Juan Carlos, Fuenlabrada (Spain)], E-mail: elage@mce.hggm.es

    2009-09-21

    This work reports on the development and performance evaluation of the VrPET/CT, a new multimodality scanner with coplanar geometry for in vivo rodent imaging. The scanner design is based on a partial-ring PET system and a small-animal CT assembled on a rotatory gantry without axial displacement between the geometric centers of both fields of view (FOV). We report on the PET system performance based on the NEMA NU-4 protocol; the performance characteristics of the CT component are not included herein. The accuracy of inter-modality alignment and the imaging capability of the whole system are also evaluated on phantom and animal studies. Tangential spatial resolution of PET images ranged between 1.56 mm at the center of the FOV and 2.46 at a radial offset of 3.5 cm. The radial resolution varies from 1.48 mm to 1.88 mm, and the axial resolution from 2.34 mm to 3.38 mm for the same positions. The energy resolution was 16.5% on average for the entire system. The absolute coincidence sensitivity is 2.2% for a 100-700 keV energy window with a 3.8 ns coincident window. The scatter fraction values for the same settings were 11.45% for a mouse-sized phantom and 23.26% for a rat-sized phantom. The peak noise equivalent count rates were also evaluated for those phantoms obtaining 70.8 kcps at 0.66 MBq/cc and 31.5 kcps at 0.11 MBq/cc, respectively. The accuracy of inter-modality alignment is below half the PET resolution, and the image quality of biological specimens agrees with measured performance parameters. The assessment presented in this study shows that the VrPET/CT system is a good performance small-animal imager, while the cost derived from a partial ring detection system is substantially reduced as compared with a full-ring PET tomograph.

  1. Short-chain chlorinated paraffins (SCCPs) in surface soil from a background area in China: occurrence, distribution, and congener profiles.

    Science.gov (United States)

    Wang, Xue-Tong; Zhang, Yuan; Miao, Yi; Ma, Ling-Ling; Li, Yuan-Cheng; Chang, Yue-Ya; Wu, Ming-Hong

    2013-07-01

    Short-chain chlorinated paraffins (SCCPs) are extremely complex technical mixtures of polychlorinated n-alkanes with carbon chain lengths from C10 to C13 and chlorine content between 49 and 70%. SCCPs are under consideration for inclusion in the Stockholm Convention on persistent organic pollutants. SCCPs have been used extensively in industrial production, but little is known about the pollution level in soil environment in China. In this study, levels and distribution of SCCPs in soil samples from Chongming Island were analyzed. Concentrations of total SCCPs in soil samples ranged from 0.42 to 420 ng g(-1), with a median of 9.6 ng g(-1). The ubiquitous occurrence of SCCPs in Chongming Island implied that long-range atmospheric transport and soil-air exchange may be the most important pathways for SCCP contamination in the background area. The localized SCCP contamination could be derived from an unidentified source. Hierarchical cluster analysis indicated that C13- and C11-congeners were predominant in most soils and C10- and C12-congeners dominated in the remaining soils. Cl7- and Cl8-congeners were on the average the most dominant chlorine congeners in nearly all soils. Principal component analysis suggested that the separation of even and odd carbon chain congeners occurred during long-range atmospheric transport and aging in soil in the study area.

  2. Levels and congener specific profiles of PBDEs in human breast milk from China: implication on exposure sources and pathways.

    Science.gov (United States)

    Sudaryanto, Agus; Kajiwara, Natsuko; Tsydenova, Oyuna V; Isobe, Tomohiko; Yu, Hongxia; Takahashi, Shin; Tanabe, Shinsuke

    2008-11-01

    Fourteen PBDE congeners from mono- to deca-BDE were determined in breast milk of primiparous mothers from two locations in East China, i.e. Nanjing (n=9), an urban area, and Zhoushan (n=10), a semi rural coastal area. PBDEs were detected in all the human breast milk samples of the present study, indicating that general population in these two locations are widely exposed to these pollutants. Relatively higher concentrations of PBDEs were found in the milk of mothers from Nanjing than Zhoushan, suggesting the existence of significant sources of PBDEs in urban areas. PBDE levels in the present study were similar to those in European countries, but one or two orders of magnitude lower than in North America. Except for BDE-3, all congeners from di- to deca-BDE were detected in the samples of the present study. BDE-209, a congener considered to have less bioavailability, was detected in about 50% of the samples at concentrations higher than that of other congeners. Other higher brominated congeners, such as BDE-153, -197 and -207, were also prominent in the present study, which is different from the pattern generally observed in previous studies on human milk as well as biota samples. These results may indicate that the inhabitants of Nanjing and Zhoushan are exposed to location specific sources of PBDEs.

  3. Chemical fingerprinting and phylogenetic mapping of saponin congeners from three tropical holothurian sea cucumbers.

    Science.gov (United States)

    Bondoc, Karen Grace V; Lee, Hyeyoung; Cruz, Lourdes J; Lebrilla, Carlito B; Juinio-Meñez, Marie Antonette

    2013-01-01

    Holothurians are sedentary marine organisms known to produce saponins (triterpene glycosides), secondary metabolites exhibiting a wide range of biological activities. In this paper, we investigated the saponin contents of semi-purified and membranolytic HPLC fractionated extracts from the body wall of three species of Holothuriidae as an attempt to examine its chemical diversity in relation to phylogenetic data. MALDI-FTICR MS and nano-HPLC-chip Q-TOF MS were used for mass profiling and isomer separation, respectively giving a unique chemical saponin fingerprint. Moreover, the methods used yield the highest number of congeners. However, saponin concentration, bioactivity and chemical diversity had no apparent relationship. MS fingerprint showed the presence of holothurinosides, which was observed for the first time in other Holothuria genera besides the basally positioned Holothuria forskali. This congener is proposed to be a primitive character that could be used for taxonomic purposes. The phylogenetic mapping also showed that the glycone part of the compound evolved from non-sulfated hexaosides to sulfated tetraosides, which have higher membranolytic activity and hydrophilicity, the two factors affecting the total ecological activity (i.e. chemical defense) of these compounds. This might be an adaptation to increase the fitness of the organism.

  4. SAR of Sponge-Inspired Hemibastadin Congeners Inhibiting Blue Mussel PhenolOxidase

    Directory of Open Access Journals (Sweden)

    Hendrik Niemann

    2015-05-01

    Full Text Available Hemibastadin derivatives, including the synthetically-derived 5,5′-dibromohemibastadin-1 (DBHB, are potent inhibitors of blue mussel phenoloxidase (PO, which is a key enzyme involved in the firm attachment of this invertebrate to substrates and, thus, a promising molecular target for anti-fouling research. For a systematic investigation of the enzyme inhibitory activity of hemibastadin derivatives, we have synthesized nine new congeners, which feature structural variations of the DBHB core structure. These structural modifications include, e.g., different halogen substituents present at the aromatic rings, different amine moieties linked to the (E-2-(hydroxyimino-3-(4-hydroxyphenylpropionic acid, the presence of free vs. substituted aromatic hydroxyl groups and a free vs. methylated oxime group. All compounds were tested for their inhibitory activity towards the target enzyme in vitro, and IC50 values were calculated. Derivatives, which structurally closely resemble sponge-derived hemibastadins, revealed superior enzyme inhibitory properties vs. congeners featuring structural moieties that are absent in the respective natural products. This study suggests that natural selection has yielded structurally-optimized antifouling compounds.

  5. Linking habitat use of Hudson River striped bass to accumulation of polychlorinated biphenyl congeners

    Energy Technology Data Exchange (ETDEWEB)

    Ashley, J.T.F.; Secor, D.H.; Zlokovitz, E.; Wales, S.Q.; Baker, J.E.

    2000-03-15

    Since 1976, the commercial striped bass fishery in the Hudson River (NY) has been closed due to total polychlorinated biphenyl (t-PCB) concentrations that exceed the US Food and Drug Administration's advisory level of 2 {micro}g/g-wet weight. Extensive monitoring of Hudson River striped bass demonstrated much more variability in t-PCB levels among individual striped bass than could be explained by their age, sex, or lipid contents. To investigate the possible role of differential habitat use among subpopulations of striped bass in controlling their PCB exposures, 70 fish collected throughout the Hudson River estuary and Long Island Sound in 1994--1995 were analyzed for PCB congeners, and their lifetime migration behaviors were estimated by otolith microchemistry. The mean salinity encountered during the fish's last growth season prior to capture was inversely correlated with the t-PCB body burden. Striped bass permanently residing in fresh and oligohaline portions of the estuary adjacent to known PCB sources had elevated t-PCB levels and congeneric patterns with higher proportions of di-, tri-, and tetrachlorobiphenyls. Conversely, fish spending the majority of their life in more saline waters of the estuary or migrating frequently throughout the salinity gradient contained lower PCB levels composed of more highly chlorinated congeners. The approach used in this study allows habitat use to be incorporated into exposure assessments for anadromous fish species such as striped bass.

  6. Microhabitat distribution of two Florida scrub endemic plants in comparison to their habitat-generalist congeners.

    Science.gov (United States)

    Maliakal-Witt, Satya; Menges, Eric S; Denslow, J S

    2005-03-01

    Habitat-specialist species may be restricted to a narrower range of microhabitats than habitat-generalist species. We addressed this hypothesis by comparing microhabitats of two pairs of congeners that differ in habitat specificity and co-occur in one distinct habitat type, Florida rosemary scrub. We characterized microhabitats of rosemary scrub specialists, Polygonella basiramia and Lechea cernua, their habitat-generalist congeners, Polygonella robusta and Lechea deckertii, and random points in the rosemary scrub habitat. Plants of both habitat specialists occurred in microhabitats with significantly more bare sand than plants of habitat-generalist species and random points. Plants of all four species occurred in microhabitats that were farther from dominant shrubs, Ceratiola and Quercus spp., than random points. Seedlings of both habitat specialists grew larger in bare sand microhabitats, whereas ground lichens and litter did not affect seedling growth of the habitat generalists. As the time since fire increases, bare sand cover decreases, Ceratiola density increases, Quercus density remains constant, and shrubs become taller. Physical characteristics, such as soil temperature, soil carbon, and soil moisture, differ slightly with respect to microhabitat. Our results suggest that P. basiramia and L. cernua are specialized on bare sand microhabitats that characterize their preferred habitat, rosemary scrub. Microhabitat specialization may limit the distribution of these rare species.

  7. Very mild disease phenotype of congenic CftrTgH(neoimHgu cystic fibrosis mice

    Directory of Open Access Journals (Sweden)

    Leonhard-Marek Sabine

    2008-04-01

    Full Text Available Abstract Background A major boost to cystic fibrosis disease research was given by the generation of various mouse models using gene targeting in embryonal stem cells. Moreover, the introduction of the same mutation on different inbred strains generating congenic strains facilitated the search for modifier genes. From the original CftrTgH(neoimHgu mouse model with a divergent genetic background (129/Sv, C57BL/6, HsdOla:MF1 two inbred mutant mouse strains CF/1-CftrTgH(neoimHgu and CF/3-CftrTgH(neoimHgu had been generated using strict brother × sister mating. CF/1-CftrTgH(neoimHgu and CF/3-CftrTgH(neoimHgu mice were fertile and showed normal growth and lifespan. In this work the CftrTgH(neoimHgu insertional mutation was backcrossed from CF/3-CftrTgH(neoimHgu onto the inbred backgrounds C57BL/6J and DBA/2J generating congenic animals in order to clarify the differential impact of the Cftr mutation and the genetic background on the disease phenotype of the cystic fibrosis mutant mice. Clinical and electrophysiological features of the two congenic strains were compared with those of CF/1-CftrTgH(neoimHgu and CF/3-CftrTgH(neoimHgu and wild type controls. Results Under the standardized housing conditions of the animal facility, the four mouse strains CF/1-CftrTgH(neoimHgu, CF/3-CftrTgH(neoimHgu, D2.129P2(CF/3-CftrTgH(neoimHgu and B6.129P2(CF/3-CftrTgH(neoimHgu exhibited normal life expectancy. Growth of congenic cystic fibrosis mice was comparable with that of wild type controls. All mice but D2.129P2(CF/3-CftrTgH(neoimHgu females were fertile. Short circuit current measurements revealed characteristic response profiles of the HsdOla:MF1, DBA/2J and C57BL/6J backgrounds in nose, ileum and colon. All cystic fibrosis mouse lines showed the disease-typical hyperresponsiveness to amiloride in the respiratory epithelium. The mean chloride secretory responses to carbachol or forskolin were 15–100% of those of the cognate wild type control animals

  8. Rectangular waveguide-to-coplanar waveguide transitions at U-band using e-plane probe and wire bonding

    DEFF Research Database (Denmark)

    Dong, Yunfeng; Johansen, Tom Keinicke; Zhurbenko, Vitaliy

    2016-01-01

    This paper presents rectangular waveguide-to-coplanar waveguide (CPW) transitions at U-band (40–60 GHz) using E-plane probe and wire bonding. The designs of CPWs based on quartz substrate with and without aluminum cover are explained. The single and double layer rectangular waveguide-to-CPW trans......This paper presents rectangular waveguide-to-coplanar waveguide (CPW) transitions at U-band (40–60 GHz) using E-plane probe and wire bonding. The designs of CPWs based on quartz substrate with and without aluminum cover are explained. The single and double layer rectangular waveguide......-to-CPW transitions using E-plane probe and wire bonding are designed. The proposed rectangular waveguide-to-CPW transition using wire bonding can provide 10 GHz bandwidth at U-band and does not require extra CPWs or connections between CPWs and chips. A single layer rectangular waveguide-to-CPW transition using E......-plane probe with aluminum package has been fabricated and measured to validate the proposed transitions. To the authors' best knowledge, this is the first time that a wire bonding is used as a probe for rectangular waveguide-to-CPW transition at U-band....

  9. Physical and plasmachemical aspects of diffuse coplanar barrier discharge as a novel atmospheric-pressure plasma source

    Science.gov (United States)

    Cernak, M.; Kovacik, D.; Zahoranova, A.; Rahel, J.

    2008-07-01

    Collaborating Czech and Slovakian university teams have recently developed an innovative plasma source, the so-called Diffuse Coplanar Surface Barrier Discharge (DCSBD), which has the potential to move a step closer to the industry requirement for in-line treatment of low-added-value materials using a highly-nonequlibrium ambient air plasma (Simor et al. 2002, The idea is to generate a thin (on the order of 0.1 mm) layer of highly-nonequlibrium plasma with a high power density (up to 100 W/cm^3) in the immediate vicinity of the treated surface and bring it into a close contact with the treated surface. Comparing to atmospheric-pressure glow discharge, volume dielectric barrier discharge, and plasma jet plasmas, such a diffuse plasma layer is believed to provide substantial advantages in energy consumption, exposure time, and technical simplicity. A brief outline of physical mechanism and basic properties of DCSBD will given using the results of emission spectroscopy, high-speed camera, and spatially resolved cross-correlation spectroscopy studies. The presentation will review also a current state of the art in in-line plasma treatment of low-cost materials and opportunities for the use of the so-called Diffuse Coplanar Surface Dielectric Barrier Discharge (DCSBD). The results obtained on the ambient air plasma treatments of textile, paper, wood, and glass illustrate that DCSBD offers outstanding performance with extremely low energy consumption for large area, uniform surface modifications of materials under continuous process conditions.

  10. Toxicity and 7-ethoxyresorufin O-deethylase-inducing potency of coplanar polychlorinated biphenyls (PCBs) in chick embryos

    Energy Technology Data Exchange (ETDEWEB)

    Brunstroem, B.; Andersson, L.

    1988-10-01

    The toxicities of the coplanar polychlorinated biphenyls 3,3',4,4'-tetrachlorobiphenyl (TCB), 3,3',4,4',5-pentachlorobiphenyl (PeCB) and 3,3',4,4',5,5'-hexachlorobiphenyl (HCB) were compared in a 72-h study on chick embryos. The substances were injectied into the air sacs of hens's eggs preincubated for 7 days. Mortality was measured 72 h later and corresponding LD/sub 50/ values were calculated. The rank order of toxicity was PeCB>TCB>HCB. Using the same injection procedure, the potencies of these chlorobiphenyls with regard to their induction of hepatic 7-ethoxyresorufin O-deethylase activity were compared. The ranking order of the substances as inducers was the same as their order when ranked according to toxicity. The three coplanar chlorobiphenyls were considerably more toxic and potent as inducers than the non-planar 2,2',4,4',5,5'-hexachlorobiphenyl. In a 2-week toxicity study, PeCB and HCB were injected into the yolks of hens' eggs preincubated for 4 days. PeCB was about 50-fold more potent than HCB in causing embryonic death. Both substances caused abnormalities, including edema, liver lesions, microphthalmia and beak deformities.

  11. Concentration of polychlorinated biphenyl (PCB) congeners in the muscle of Clarias gariepinus and sediment from inland rivers of southwestern Nigeria and estimated potential human health consequences.

    Science.gov (United States)

    Adeogun, Aina O; Chukwuka, Azubuike V; Okoli, Chukwunonso P; Arukwe, Augustine

    2016-01-01

    The distributions of polychlorinated biphenyl (PCB) congeners were determined in sediment and muscle of the African sharptooth catfish (Clarias gariepinus) from the Ogun and Ona rivers, southwest Nigeria. In addition, the effect of PCB congeners on condition factor (CF) and associated human health risk was assessed using muscle levels for a noncarcinogenic hazard quotient (HQ) calculation. Elevated concentrations of high-molecular-weight (HMW) PCB congeners were detected in sediment and fish downstream of discharge points of both rivers. A significant reduction in fish body weight and CF was observed to correlate with high PCB congener concentrations in the Ona River. A principal component (PC) biplot revealed significant site-related PCB congener distribution patterns for HMW PCB in samples from the Ogun River (71.3%), while the Ona River (42.6%) showed significant PCB congener patterns for low-molecular-weight (LMW) congeners. Biota-sediment accumulation factor (BSAF) was higher downstream for both rivers, presenting PCB congener-specific accumulation patterns in the Ona River. Significant decreases in fish body weight, length and CF were observed downstream compared to upstream in the Ona River. The non-carcinogenic HQ of dioxin-like congener 189 downstream in both rivers exceeded the HQ = 1 threshold for children and adults for both the Ogun and Ona rivers. Overall, our results suggest that industrial discharges contribute significantly to PCB inputs into these rivers, with potential for significant health implications for neighboring communities that utilize these rivers for fishing and other domestic purposes.

  12. Determination of toxaphene specific congeners in fish liver oil and feedingstuff using gas chromatography coupled to high resolution mass spectrometry.

    Science.gov (United States)

    Veyrand, Bruno; Venisseau, Anaïs; Marchand, Philippe; Antignac, Jean-Philippe; Le Bizec, Bruno

    2008-04-01

    A new method for the determination of nine toxaphene specific congeners in fish liver oil and feedingstuff has been developed. The samples were extracted using pressurized liquid extraction followed by a purification on silica and florisil columns. Identification and quantification were conducted using GC-(EI)-HRMS, and comparison with MS/MS detection was performed, using electron ionization and negative chemical ionization. Limits of detection were ranged from 0.01 to 0.22 microg kg(-1) (12% moisture) as required for feed samples. The calibration curves showed a good linearity for all congeners (R(2)>0.99). Repeatability was below 9% for all the congeners and recoveries were in-between 73 and 86%. This analytical method was applied to the quantification of thirteen real samples collected within national monitoring plans for further risk assessment.

  13. SU-E-T-217: Comprehensive Dosimetric Evaluation On 3D-CRT, IMRT and Non-Coplanar Arc Treatment for Prone Accelerated Partial Breast Irradiation (APBI)

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, T; Yan, Y; Ramirez, E; Lee, P; Jiang, S; Gu, X [UT Southwestern Medical Center, Dallas, TX (United States)

    2015-06-15

    Purpose: Accelerated partial breast irradiation (APBI) is an effective treatment for early stage breast-cancer. Irradiation in a prone position can mitigate breast motion and spare heart and lung. In this study, a comprehensive study is performed to evaluate various treatment techniques for prone APBI treatment including: 3D-CRT, IMRT, co-planar and non-coplanar partial arcs treatment. Methods: In this treatment planning study, a left breast patient treated in prone position in our clinic was imported into Varian Eclipse TPS. Six beams tangential to chest wall were used in both 3D-CRT and IMRT plans. These six beams were coplanar in a transactional plane achieved by both gantry and couch rotation. A 60-beam IMRT plan was also created to explore the maximum benefit of co-planar IMRT. Within deliverable couch rotation range (±30°), partial arc treatment plans with one and up to ten couch positions were generated for comparison. For each plan, 30Gy in 6 fractions was prescribed to 95% PTV volume. Critical dosimetric parameters, such as conformity index, mean, maximum, and volume dose of organ at risk, are evaluated. Results: The conformity indexes (CI) are 3.53, 3.17, 2.21 and 1.08 respectively to 3D-CRT, 6-beam IMRT, 60-beam IMRT, and two-partial-arcs coplanar plans. However, arc plans increase heart dose. CI for non-coplanar arc plans decreases from 1.19 to 1.10 when increases couch positions. Maximum dose in ipsilateral lung (1.98 to 1.13 Gy), and heart (0.62 to 0.43 Gy) are steadily decreased with the increased number of non-coplanar arcs. Conclusions: The dosimetric evaluation results show that partial arc plans have improved CIs compared to conventional 3D-CRT and IMRT plans. Increasing number of partial arcs decreases lung and heart dose. The dosimetric benefit obtained from non-coplanar arcs should be considered with treatment delivery time.

  14. Theoretical calculation of the triple differential cross sections of the 2p orbital of argon in a coplanar highly asymmetric (e, 2e) reaction

    Institute of Scientific and Technical Information of China (English)

    葛自明; 周雅君; 吕志伟; 王治文

    2002-01-01

    The triple differential cross sections of the 2p electron of argon in a coplanar highly asymmetric geometry have beencalculated with the modified distorted wave Born approximation (DWBA) and the target Hartree-Fock approximationmethods. The damping polarization of the semi-classical short-range potentials and the Mee factor are included in thedistorting potentials of the modified DWBA. Theoretical results are compared with a recent experiment. The dynamicmechanism of inner shell ionization in a coplanar highly asymmetric geometry (e, 2e) reaction are also discussed.

  15. Reduction of thyroid hormone levels by methylsulfonyl metabolites of polychlorinated biphenyl congeners in rats

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Yoshihisa; Shibahara, Tomoo; Kimura, Ryohei [School of Pharmaceutical Sciences, University of Shizuoka (Japan); Haraguchi, Koichi; Masuda, Yoshito [Daiichi College of Pharmaceutical Sciences, Fukuoka (Japan)

    1998-07-01

    Male Sprague-Dawley rats received four consecutive intraperitoneal doses of four kinds of methylsulfonyl (MeSO{sub 2}) metabolites of polychlorinated biphenyl (PCB) congeners: 3-MeSO{sub 2}-2,2`,3`,4`,5,6-hexachlorobiphenyl (3-MeSO{sub 2}-CB132); 3-MeSO{sub 2}-2,2`,3`,4`, 5,5`-hexachlorobiphenyl (3-MeSO{sub 2}-CB141); 3-MeSO{sub 2}-2,2`,4`,5,5`,6-hexachlorobiphenyl (3-MeSO{sub 2}-CB149) and 4-MeSO{sub 2}-2,2`,4`,5,5`,6-hexachlorobiphenyl (4-MeSO{sub 2}-CB149). The congeners were major MeSO{sub 2}-PCBs determined in human milk, liver and adipose tissue, and the aim was to determine their effect on thyroid hormone levels. All four tested MeSO{sub 2} metabolites (20 {mu}mol/kg once daily for 4 days) reduced serum total thyroxine levels by 22-44% at a much lower dose than phenobarbital (PB; 431 {mu}mol/kg once daily for 4 days) on days 2, 3, 4 and 7 after the final doses. Total triiodothyronine levels were reduced 37% by treatment with 4-MeSO{sub 2}-CB149 at day 7. A 30% increase in thyroid weight was produced by 3-MeSO{sub 2}-CB141 treatment. Total cytochrome P450 content was increased by 3-MeSO{sub 2}-CB132, 3-MeSO{sub 2}-CB141 and 3-MeSO{sub 2}-CB149, but not by 4-MeSO{sub 2}-CB149. Thus, it is likely that the 3-MeSO{sub 2}-hexachlorobiphenyls and 4-MeSO{sub 2}-CB149 could influence the thyroid hormone metabolism by different mechanism(s). The results show that tested 3- and 4-MeSO{sub 2} metabolites of PCB congeners reduce thyroid hormone levels much more than PB in rats. Our finding suggests that the metabolites may act as endocrine-disrupters. (orig.) With 2 figs., 1 tab., 25 refs.

  16. iCycle: Integrated, multicriterial beam angle, and profile optimization for generation of coplanar and noncoplanar IMRT plans

    Energy Technology Data Exchange (ETDEWEB)

    Breedveld, Sebastiaan; Storchi, Pascal R. M.; Voet, Peter W. J.; Heijmen, Ben J. M. [Department of Radiation Oncology, Erasmus MC Rotterdam, Groene Hilledijk 301, 3075 EA Rotterdam (Netherlands)

    2012-02-15

    Purpose: To introduce iCycle, a novel algorithm for integrated, multicriterial optimization of beam angles, and intensity modulated radiotherapy (IMRT) profiles. Methods: A multicriterial plan optimization with iCycle is based on a prescription called wish-list, containing hard constraints and objectives with ascribed priorities. Priorities are ordinal parameters used for relative importance ranking of the objectives. The higher an objective priority is, the higher the probability that the corresponding objective will be met. Beam directions are selected from an input set of candidate directions. Input sets can be restricted, e.g., to allow only generation of coplanar plans, or to avoid collisions between patient/couch and the gantry in a noncoplanar setup. Obtaining clinically feasible calculation times was an important design criterium for development of iCycle. This could be realized by sequentially adding beams to the treatment plan in an iterative procedure. Each iteration loop starts with selection of the optimal direction to be added. Then, a Pareto-optimal IMRT plan is generated for the (fixed) beam setup that includes all so far selected directions, using a previously published algorithm for multicriterial optimization of fluence profiles for a fixed beam arrangement Breedveld et al.[Phys. Med. Biol. 54, 7199-7209 (2009)]. To select the next direction, each not yet selected candidate direction is temporarily added to the plan and an optimization problem, derived from the Lagrangian obtained from the just performed optimization for establishing the Pareto-optimal plan, is solved. For each patient, a single one-beam, two-beam, three-beam, etc. Pareto-optimal plan is generated until addition of beams does no longer result in significant plan quality improvement. Plan generation with iCycle is fully automated. Results: Performance and characteristics of iCycle are demonstrated by generating plans for a maxillary sinus case, a cervical cancer patient, and a

  17. On the beam direction search space in computerized non-coplanar beam angle optimization for IMRT-prostate SBRT.

    Science.gov (United States)

    Rossi, Linda; Breedveld, Sebastiaan; Heijmen, Ben J M; Voet, Peter W J; Lanconelli, Nico; Aluwini, Shafak

    2012-09-01

    In a recent paper, we have published a new algorithm, designated 'iCycle', for fully automated multi-criterial optimization of beam angles and intensity profiles. In this study, we have used this algorithm to investigate the relationship between plan quality and the extent of the beam direction search space, i.e. the set of candidate beam directions that may be selected for generating an optimal plan. For a group of ten prostate cancer patients, optimal IMRT plans were made for stereotactic body radiation therapy (SBRT), mimicking high dose rate brachytherapy dosimetry. Plans were generated for five different beam direction input sets: a coplanar (CP) set and four non-coplanar (NCP) sets. For CP treatments, the search space consisted of 72 orientations (5° separations). The NCP CyberKnife (CK) space contained all directions available in the robotic CK treatment unit. The fully non-coplanar (F-NCP) set facilitated the highest possible degree of freedom in selecting optimal directions. CK(+) and CK(++) were subsets of F-NCP to investigate some aspects of the CK space. For each input set, plans were generated with up to 30 selected beam directions. Generated plans were clinically acceptable, according to an assessment of our clinicians. Convergence in plan quality occurred only after around 20 included beams. For individual patients, variations in PTV dose delivery between the five generated plans were minimal, as aimed for (average spread in V(95): 0.4%). This allowed plan comparisons based on organ at risk (OAR) doses, with the rectum considered most important. Plans generated with the NCP search spaces had improved OAR sparing compared to the CP search space, especially for the rectum. OAR sparing was best with the F-NCP, with reductions in rectum D(Mean), V(40Gy), V(60Gy) and D(2%) compared to CP of 25%, 35%, 37% and 8%, respectively. Reduced rectum sparing with the CK search space compared to F-NCP could be largely compensated by expanding CK with beams with

  18. Four new doramectin congeners with acaricidal and insecticidal activity from Streptomyces avermitilis NEAU1069.

    Science.gov (United States)

    Wang, Xiang-Jing; Zhang, Ji; Wang, Ji-Dong; Huang, Sheng-Xiong; Chen, Yi-Hua; Liu, Chong-Xi; Xiang, Wen-Sheng

    2011-11-01

    Four new doramectin congeners, 1-4, were isolated from Streptomyces avermitilis NEAU1069. The structures of 1-4 were elucidated on the basis of spectroscopic analysis, including 1D- and 2D-NMR as well as HR-ESI-MS, ESI-MS, UV, and IR, and comparison with literature data. All compounds exhibited noticeable acaricidal and insecticidal activities. Especially compound 2 was found to be the most potent pesticide of the compounds evaluated with the IC(50) values of 10.2, 65.1 and 124.4 μg/ml against adult two-spotted spider mites (Tetranychus urticae Koch), two-spotted spider mite eggs, and Mythimna separata, respectively, which are comparable to those of commercial pesticide milbemycin A(3)/A(4) as positive reference.

  19. Rhizospere Redox Cycling and Implications for Rhizosphere Biotransformation of Selected Polychlorinated Biphenyl (PCB) Congeners.

    Science.gov (United States)

    Meggo, Richard E; Schnoor, Jerald L

    2013-08-01

    Theoretically, sequential cycles of dechlorination followed by aerobic bio-oxidation are desirable to achieve complete degradation of a mixture of higher and lower chlorinated PCBs. In this research, soil was artificially contaminated with polychlorinated biphenyls (PCBs) in mixture and as single congeners, aged, and planted with two different plant species. Alternating redox cycles were created in the root zone of plants by flooding and draining the soil. Over 32 weeks, switchgrass (Panicum virgatum) and poplar (Populus deltoids x nigra DN34) planted systems that were exposed to alternate cycles of flooding performed better in reducing parent PCBs than planted systems that were not cycled (p<0.05). The cycled systems also had a higher mass of PCB transformation products than the uncycled systems. Multiple cycles were necessary to achieve significant differences between the cycled and uncycled treatments.

  20. Gateway synthesis of daphnane congeners and their protein kinase C affinities and cell-growth activities

    Science.gov (United States)

    Wender, Paul A.; Buschmann, Nicole; Cardin, Nathan B.; Jones, Lisa R.; Kan, Cindy; Kee, Jung-Min; Kowalski, John A.; Longcore, Kate E.

    2011-08-01

    The daphnane diterpene orthoesters constitute a structurally fascinating family of natural products that exhibit a remarkable range of potent biological activities. Although partial activity information is available for some natural daphnanes, little information exists for non-natural congeners or on how changes in structure affect mode of action, function, potency or selectivity. A gateway strategy designed to provide general synthetic access to natural and non-natural daphnanes is described and utilized in the synthesis of two novel members of this class. In this study, a commercially available tartrate derivative was elaborated through a key late-stage diversification intermediate into B-ring yuanhuapin analogues to initiate exploration of the structure-function relationships of this class. Protein kinase C was identified as a cellular target for these agents, and their activity against human lung and leukaemia cell lines was evaluated. The natural product and a novel non-natural analogue exhibited significant potency, but the epimeric epoxide was essentially inactive.

  1. Synthesis and biological evaluation of novel biaryl type α-noscapine congeners.

    Science.gov (United States)

    Manchukonda, Naresh K; Naik, Pradeep K; Sridhar, Balasubramanian; Kantevari, Srinivas

    2014-12-15

    Natural α-noscapine, a known antitussive drug, is also now known to possess weak anticancer efficacy with relatively safe toxicity profile. In this study, we report synthesis and evaluation of novel biaryl type α-noscapine congeners designed by adding aryl unit to the tetrahydroisoquinoline part of natural α-noscapine core. Palladium catalyzed Suzuki cross coupling of 9-bromo α-noscapine with aryl boronic acids was employed using mild and inexpensive reagents to attain desired noscapinoids 5a-g in excellent yields. Screening anti-proliferative activity for new noscapinoids 5b-g, on human cancer cell lines resulted three compounds 5b, 5d and 5f as potent analogues, active against human breast epithelial (MCF-7), human cervix cancer (HeLa) and human lung adenocarcinoma epithelial (A549) cell lines.

  2. Spontaneous metastasis in congenic mice with transgenic breast cancer is unaffected by plasminogen gene ablation

    DEFF Research Database (Denmark)

    Almholt, Kasper; Juncker-Jensen, Anna; Lærum, Ole Didrik;

    2013-01-01

    , suggesting that there is a functional redundancy with other proteases. To explore this functional overlap in the transgenic MMTV-PyMT breast cancer metastasis model, we have combined Plg deficiency and a pharmacological metalloprotease inhibitor, which is known to reduce metastasis in this model, and has...... been shown to synergistically inhibit other tissue remodeling events in Plg-deficient mice. While metalloprotease inhibition dramatically reduced metastasis, we found no effect of Plg deficiency on metastasis, either independently or in combination with metalloprotease inhibition. We further show...... that Plg gene deficiency is of no significant consequence in this metastasis model, when analyzed in two different congenic strains: the FVB strain, and a F1 hybrid of the FVB and C57BL/6J strains. We suggest that the extensive backcrossing performed prior to our studies has eliminated the confounding...

  3. Dose comparison between three planing prostate: 3-D conformational radiotherapy, coplanar arc therapy and non-coplanar arc therapy; Comparaison dosimetrique de trois balistiques prostatiques: radiotherapie conformationnelle tridimensionnelle, arctherapie coplanaire et arctherapie non-coplanaire

    Energy Technology Data Exchange (ETDEWEB)

    Voyant, C.; Baadj, A.; Biffi, K.; Leschi, D.; Lantieri, C. [Centre Hospitalier Dept. Castelluccio, Service de Radiotherapie, Ajaccio (France); Voyant, C. [Universite de Corse, Lab. SPE, CNRS-UMR 6134, Corte (France)

    2008-09-15

    Purpose: Comparative study between a classical conformational prostate radiotherapy (3 D.R.T.C.) and two arc therapy techniques, a coplanar (A.T.-C) and the other non-coplanar (A.T.-N.C.). Patients and Methods:The comparison has been made retrospectively on 30 patients with localized prostate cancer (T.2-T.3a, P.S.A. < 20 ng/ml, Gleason < 7). The objective criteria for comparison were the N.T.C.P., E.U.D., and dose volume (on D.V.H.), for the volumes of bladder wall, rectal wall, femoral heads, small bowel, prostate (P) and seminal vesicles (V.S.). The treatment was 46 Gy on P.T.V.1 (V.S. + P + margins), and then an overdose of 30 Gy on P.T.V.1 (P + margins). Results: For prostate volumes exceeding 75 cm{sup 3}, arc therapy leads to a decrease in uniformity in the target volume and an increase in the dose received by the femoral heads, this method does not seem appropriate. For prostate volumes less than 75 cm{sup 3}, in addition to the coverage almost tumor, and radiation toxicity equivalent to the bladder and the small intestine, there is a significant increase in the dose to the femoral heads, while the remaining is still within limits, such as clinically tolerable. The contribution of arc therapy is mainly observed at the level of rectal doses. The dose received by 30% of the rectum is reduced by - 12% for A.T.-C and - 11.7% for A.T-N.C., and E.U.D. rectum - 5.2% and - 4.8%. Conclusion: In this virtual study, the arc therapy seems to generate a true dose reduction in the rectum wall. These results encourage us to continue the investigation for a possible integration in a dynamic clinical routine. (authors)

  4. Nasal bone shape is under complex epistatic genetic control in mouse interspecific recombinant congenic strains.

    Directory of Open Access Journals (Sweden)

    Gaétan Burgio

    Full Text Available BACKGROUND: Genetic determinism of cranial morphology in the mouse is still largely unknown, despite the localization of putative QTLs and the identification of genes associated with Mendelian skull malformations. To approach the dissection of this multigenic control, we have used a set of interspecific recombinant congenic strains (IRCS produced between C57BL/6 and mice of the distant species Mus spretus (SEG/Pas. Each strain has inherited 1.3% of its genome from SEG/Pas under the form of few, small-sized, chromosomal segments. RESULTS: The shape of the nasal bone was studied using outline analysis combined with Fourier descriptors, and differential features were identified between IRCS BcG-66H and C57BL/6. An F2 cross between BcG-66H and C57BL/6 revealed that, out of the three SEG/Pas-derived chromosomal regions present in BcG-66H, two were involved. Segments on chromosomes 1 (∼32 Mb and 18 (∼13 Mb showed additive effect on nasal bone shape. The three chromosomal regions present in BcG-66H were isolated in congenic strains to study their individual effect. Epistatic interactions were assessed in bicongenic strains. CONCLUSIONS: Our results show that, besides a strong individual effect, the QTL on chromosome 1 interacts with genes on chromosomes 13 and 18. This study demonstrates that nasal bone shape is under complex genetic control but can be efficiently dissected in the mouse using appropriate genetic tools and shape descriptors.

  5. Do settlement dynamics influence competitive interactions between an alien tunicate and its native congener?

    Science.gov (United States)

    Bouchemousse, Sarah; Lévêque, Laurent; Viard, Frédérique

    2017-01-01

    Variation in density of early stages, that is, larvae and juveniles, is a major determinant of the distribution and abundance of the adult population of most marine invertebrates. These early stages thus play a key role in competitive interactions, and, more specifically, in invasion dynamics when biologically similar native and non-native species (NNS) come into contact in the same habitat. We examined the settlement dynamics and settlement rate of two important members of the fouling community that are common on human-made infrastructures around the world: Ciona robusta (formerly known as Ciona intestinalis type A) and C. intestinalis (formerly known as C. intestinalis type B). In the western English Channel, the two species live in close syntopy following the recent introduction of C. robusta in the native European range of C. intestinalis. Using settlement panels replaced monthly over 2 years in four marinas (including one studied over 4 years) and species-diagnostic molecular markers to distinguish between juveniles of both species (N = 1,650), we documented similar settlement dynamics of both species, with two settlement periods within a calendar year. With one exception, settlement times were highly similar in the congeners. Although the NNS showed lower settlement density than that of the native congener, its juvenile recruitment was high during the second settlement period that occurs after the warm season, a pattern also observed in adult populations. Altogether, our results suggest that species' settlement dynamics do not lead to the dominance of one species over the other through space monopolization. In addition, we showed that changes over time are more pronounced in the NNS than in the native species. This is possibly due to a higher sensitivity of the NNS to changes of environmental factors such as temperature and salinity. Environmental changes may thus eventually modify the strength of competitive interactions between the two species as

  6. The Application of the FDTD Method to Millimeter-Wave Filter Circuits Including the Design and Analysis of a Compact Coplanar

    Science.gov (United States)

    Oswald, J. E.; Siegel, P. H.

    1994-01-01

    The finite difference time domain (FDTD) method is applied to the analysis of microwave, millimeter-wave and submillimeter-wave filter circuits. In each case, the validity of this method is confirmed by comparison with measured data. In addition, the FDTD calculations are used to design a new ultra-thin coplanar-strip filter for feeding a THz planar-antenna mixer.

  7. A Survey of Polychlorinated Dibenzo-p-dioxins, Polychlorinated Dibenzofurans and Co-planar Polychlorinated Biphenyls in U.S. Meat and Poultry, 2007-2008

    Science.gov (United States)

    A statistically-based survey of dioxins and dioxin-like compounds in domestic meat and poultry was conducted by the U.S. Department of Agriculture (USDA) from September 2007 to September 2008. Seventeen toxic polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and three coplanar pol...

  8. (e, 2e) triple-differential cross sections for Ag+(4p, 4s) in coplanar symmetric geometry

    Institute of Scientific and Technical Information of China (English)

    Zhou Li-Xia; Yan You-Guo

    2012-01-01

    The (e,2e) triple-differential cross sections of Ag+ (4p,4s) are calculated based on the three-body distorted-wave Born approximation considering post-collision interaction in coplanar symmetric geometry.The energy of the outgoing electron is set to be 50,70,100,200,300,500,700,and 1000 eV,and the intensity and splitting of forward and backward peaks are discussed in detail.Some new structures are observed around 15° and 85° for 4p and 4s orbitals.Structures in triple-differential cross sections at 15° are reported for the first time.A double-binary collision is proposed to explain the formation of such structures.The structures at 85° are also considered as the result of one kind of double-binary collision.

  9. Numerical and Analytical Study of Optimal Low-Thrust Limited-Power Transfers between Close Circular Coplanar Orbits

    Directory of Open Access Journals (Sweden)

    Sandro da Silva Fernandes

    2007-01-01

    Full Text Available A numerical and analytical study of optimal low-thrust limited-power trajectories for simple transfer (no rendezvous between close circular coplanar orbits in an inverse-square force field is presented. The numerical study is carried out by means of an indirect approach of the optimization problem in which the two-point boundary value problem, obtained from the set of necessary conditions describing the optimal solutions, is solved through a neighboring extremal algorithm based on the solution of the linearized two-point boundary value problem through Riccati transformation. The analytical study is provided by a linear theory which is expressed in terms of nonsingular elements and is determined through the canonical transformation theory. The fuel consumption is taken as the performance criterion and the analysis is carried out considering various radius ratios and transfer durations. The results are compared to the ones provided by a numerical method based on gradient techniques.

  10. Influence of patterned electrode geometry on performance of co-planar, single-chamber, solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sung-Jin; Kim, Yong-Bum; Moon, Jooho [Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea); Lee, Jong-Ho; Kim, Joosun [Nano-Materials Research Center, KIST, Seoul 136-791 (Korea)

    2007-09-27

    Co-planar, single-chamber, solid oxide fuel cells (SC-SOFCs) with linearly patterned electrode structures on one surface of the electrolyte are fabricated via a robo-dispensing method. The SC-SOFCs with various electrode patterns are prepared to investigate the relationship between electrode geometry and cell performance. The open-circuit voltage (OCV) for cells with a single electrode pair is unaffected by the anode-to-cathode distance. By contrast, for cells with multiple electrode pairs, increasing the number of electrode pairs leads to a gradual decrease in OCV. These observations confirm that the inter-mixing of product gases causes a loss in OCV and power density, which in turn reduces the oxygen partial pressure gradient between the anode and cathode. Keeping the electrode pairs apart by {proportional_to}4 mm permits cells with complex electrode geometry to exhibit higher OCVs and power densities. (author)

  11. Evaluation of electromechanical coupling parameters of piezoelectric materials by using piezoelectric cantilever with coplanar electrode structure in quasi-stasis.

    Science.gov (United States)

    Zheng, Xuejun; Zhu, Yuankun; Liu, Xun; Liu, Jing; Zhang, Yong; Chen, Jianguo

    2014-02-01

    Based on Timoshenko beam theory, a principle model is proposed to establish the relationship between electric charge and excitation acceleration, and in quasi-stasis we apply the direct piezoelectric effect of multilayer cantilever with coplanar electrode structure to evaluate the piezoelectric strain coefficient d15 and electromechanical coupling coefficient k15. They are measured as 678 pC/N and 0.74 for the commercial piezoelectric ceramic lead zirconate titanate (PZT-51) bulk specimen and 656 pC/N and 0.63 for the lead magnesium niobate (PMN) bulk specimen, and they are in agreement with the calibration and simulation values. The maximum of relative errors is less than 4.2%, so the proposed method is reliable and convenient.

  12. Influence of patterned electrode geometry on performance of co-planar, single-chamber, solid oxide fuel cell

    Science.gov (United States)

    Ahn, Sung-Jin; Kim, Yong-Bum; Moon, Jooho; Lee, Jong-Ho; Kim, Joosun

    Co-planar, single-chamber, solid oxide fuel cells (SC-SOFCs) with linearly patterned electrode structures on one surface of the electrolyte are fabricated via a robo-dispensing method. The SC-SOFCs with various electrode patterns are prepared to investigate the relationship between electrode geometry and cell performance. The open-circuit voltage (OCV) for cells with a single electrode pair is unaffected by the anode-to-cathode distance. By contrast, for cells with multiple electrode pairs, increasing the number of electrode pairs leads to a gradual decrease in OCV. These observations confirm that the inter-mixing of product gases causes a loss in OCV and power density, which in turn reduces the oxygen partial pressure gradient between the anode and cathode. Keeping the electrode pairs apart by ∼4 mm permits cells with complex electrode geometry to exhibit higher OCVs and power densities.

  13. A First-Order Analytical Theory for Optimal Low-Thrust Limited-Power Transfers between Arbitrary Elliptical Coplanar Orbits

    Directory of Open Access Journals (Sweden)

    Sandro da Silva Fernandes

    2008-01-01

    Full Text Available A complete first-order analytical solution, which includes the short periodic terms, for the problem of optimal low-thrust limited-power transfers between arbitrary elliptic coplanar orbits in a Newtonian central gravity field is obtained through canonical transformation theory. The optimization problem is formulated as a Mayer problem of optimal control theory with Cartesian elements—position and velocity vectors—as state variables. After applying the Pontryagin maximum principle and determining the maximum Hamiltonian, classical orbital elements are introduced through a Mathieu transformation. The short periodic terms are then eliminated from the maximum Hamiltonian through an infinitesimal canonical transformation built through Hori method. Closed-form analytical solutions are obtained for the average canonical system by solving the Hamilton-Jacobi equation through separation of variables technique. For transfers between close orbits a simplified solution is straightforwardly derived by linearizing the new Hamiltonian and the generating function obtained through Hori method.

  14. Design and analysis of an electronically steerable microstrip patch and a novel Coplanar Waveguide (CPW) fed slot antenna array

    Science.gov (United States)

    Aldossary, Hamad

    Conformal Phased Array Antennas (CPAAs) are very attractive for their high gain, low profile, and beam scanning ability while being conformal to their mounting surface. Among them are microstrip patch phased arrays and wideband slot phased arrays which are of particular significance. In this work, first the study, design, and implementation of a conformal microstrip patch phased array is presented which consists of a high gain beam scanning array implemented using microstrip delay lines controlled using GaAs SPDT switches. Then the study and design of a wideband Coplanar Waveguide (CPW)-fed slot phased array antenna is presented. In both cases the array beam scanning properties are elucidated by incorporating the measured delay line scattering parameters inside Ansys Designer simulation models and then computing and presenting their full-wave radiation characteristics.

  15. A Nafion®-based co-planar electrode amperometric sensor for methanol determination in the gas phase

    Indian Academy of Sciences (India)

    K Wallgren; S Sotiropoulos

    2009-09-01

    A co-planar electrode device, fabricated with all electrodes (working, counter and reference) on the same face of a Nafion® polymer electrolyte membrane, is proposed for the amperometric detection of gaseous methanol using Pt as the working electrode. Clear voltammetry is obtained for methanol oxidation from its vapours in equilibrium with methanol aqueous solutions, both in the absence and presence of oxygen in the gas stream. Using an appropriate pulse sequence to keep the indicator electrode active, methanol vapours in the 1-13 Torr partial pressure range (in equilibrium with methanol aqueous solutions in the 1-10% w/w concentration range) could be determined, in a constant potential, amperometric mode. The methanol detector could be operated both in a nitrogen stream and (in what is essential for practical applications) in an air atmosphere too, with estimated detection limits of 1.2 and 1.4 Torr respectively.

  16. Novel double-congenic strain reveals effects of spontaneously hypertensive rat chromosome 2 on specific lipoprotein subfractions and adiposity.

    Science.gov (United States)

    Seda, Ondrej; Sedová, Lucie; Liska, Frantisek; Krenová, Drahomíra; Prejzek, Vratislav; Kazdová, Ludmila; Tremblay, Johanne; Hamet, Pavel; Kren, Vladimír

    2006-10-01

    We have developed a new, double-congenic rat strain BN-Lx.SHR2, which carries two distinct segments of chromosome 2 introgressed from the spontaneously hypertensive rat strain (SHR) into the genetic background of congenic strain BN-Lx, which was previously shown to express variety of metabolic syndrome features. In 16-wk-old male rats of BN-Lx and BN-Lx.SHR2 strains, we compared their glucose tolerance and triacylglycerol and cholesterol concentrations in 20 lipoprotein subfractions and the lipoprotein particle sizes under conditions of feeding standard and high-sucrose diets. Introgression of two distinct SHR-derived chromosome 2 segments resulted in decreased adiposity together with aggravation of glucose intolerance in the double-congenic strain. The BN-Lx.SHR2 rats were more sensitive to sucrose-induced rise in triacylglycerolemia. Although the total cholesterol concentrations of the two strains were comparable after the standard diet and even lower in BN-Lx.SHR2 after sucrose feeding, detailed analysis revealed that under both dietary conditions, the double-congenic strain had significantly higher cholesterol concentrations in low-density lipoprotein fractions and lower high-density lipoprotein fractions. We established a new inbred model showing dyslipidemia and mild glucose intolerance without obesity, attributable to specific genomic regions. For the first time, the chromosome 2 segments of SHR origin are shown to influence other than blood pressure-related features of metabolic syndrome or to be involved in relevant nutrigenomic interactions.

  17. HIGH RESOLUTION MODELLING OF PCB CONGENERS IN LAKE MICHIGAN USING THE LAKE MICHIGAN (LM3) CONTAMINANT MODEL

    Science.gov (United States)

    The Lake Michigan Level 3 (LM3) Model is a numerical model of Lake Michigan used to predict the fate and transport of 54 PCB congeners. The LM3 model segments Lake Michigan horizontally with a 5 x 5 km grid and vertically with 19 sigma layers for a total of 44,042 water column se...

  18. Response to Ecological Risk Assessment Forum Request for Information on the Benefits of PCB Congener-Specific Analyses

    Science.gov (United States)

    In August, 2001, the Ecological Risk Assessment Forum (ERAF) submitted a formal question to the Ecological Risk Assessment Support Center (ERASC) on the benefits of evaluating PCB congeners in environmental samples. This question was developed by ERAF members Bruce Duncan and Cla...

  19. Analysis of major congeners of polybromobiphenyls and polybromodiphenyl ethers in office dust using high resolution gas chromatography-mass spectrometry.

    Science.gov (United States)

    Kefeni, Kebede K; Okonkwo, Jonathan O

    2012-05-01

    The study focused on analysis of polybromobiphenyls (PBBs) and polybromodiphenyl ethers (PBDEs) congeners in office dust obtained in Pretoria, South Africa. Of the 32 congeners considered for identification, (BB-1, 2, 4, 10, 15, 26, 29, 30, 31, 38, 49, 80, 103, 153, 155, 209 and BDE-3, 15, 17, 28, 47, 66, 77, 85, 99, 100, 126, 138, 153, 154, 183, 209) only BB-2, 4, 30, 153, 209 and BDE-47, 66, 85, 99, 153 and 209 congeners were detected. The sum of PBBs concentration detected in office dust ranged from congeners detected. Concentrations of PBDEs detected in this study are substantially lower than reported in office dust in developed countries.

  20. Increased susceptibility to collagen-induced arthritis in female mice carrying congenic Cia40/Pregq2 fragments

    DEFF Research Database (Denmark)

    Liljander, Maria; Andersson, Åsa Inga Maria; Holmdahl, Rikard;

    2008-01-01

    of the B10.Q strain. The major polymorphic candidate genes for the effects on CIA are Cd79b, Abca8a, and Map2k6. The congenic fragment also contains polymorphic genes that affect reproductive behavior and reproductive success. The Sox9 gene, known to influence sex reversal, is a candidate gene...... with another locus, denoted Pregq2, known to affect reproductive success. The present study was performed to evaluate the role of the Cia40 locus in congenic B10.Q mice and to identify possible polymorphic candidate genes, which may also be relevant in the context of RA. METHODS: Congenic B10.Q mice carrying...... an NFR/N fragment surrounding the Cia40/Pregq2 loci were created by 10 generations of backcrossing (N10). The congenic mice were investigated in the CIA model, and the incidence and severity of arthritis as well as the serum levels of anti-collagen II (CII) antibodies were recorded. RESULTS: Significant...

  1. Dosimetric comparison of preoperative single-fraction partial breast radiotherapy techniques: 3D CRT, noncoplanar IMRT, coplanar IMRT, and VMAT.

    Science.gov (United States)

    Yoo, Sua; Blitzblau, Rachel; Yin, Fang-Fang; Horton, Janet K

    2015-01-08

    The purpose of this study was to compare dosimetric parameters of treatment plans among four techniques for preoperative single-fraction partial breast radiotherapy in order to select an optimal treatment technique. The techniques evaluated were noncoplanar 3D conformal radiation therapy (3D CRT), noncoplanar intensity-modulated radiation therapy (IMRTNC), coplanar IMRT (IMRTCO), and volumetric-modulated arc therapy (VMAT). The planning CT scans of 16 patients in the prone position were used in this study, with the single-fraction prescription doses of 15 Gy for the first eight patients and 18 Gy for the remaining eight patients. Six (6) MV photon beams were designed to avoid the heart and contralateral breast. Optimization for IMRT and VMAT was performed to reduce the dose to the skin and normal breast. All plans were normalized such that 100% of the prescribed dose covered greater than 95% of the clinical target volume (CTV) consisting of gross tumor volume (GTV) plus 1.5 cm margin. Mean homogeneity index (HI) was the lowest (1.05 ± 0.02) for 3D CRT and the highest (1.11 ± 0.04) for VMAT. Mean conformity index (CI) was the lowest (1.42 ± 0.32) for IMRTNC and the highest (1.60 ± 0.32) for VMAT. Mean of the maximum point dose to skin was the lowest (73.7 ± 11.5%) for IMRTNC and the highest (86.5 ± 6.68%) for 3D CRT. IMRTCO showed very similar HI, CI, and maximum skin dose to IMRTNC (differences radiotherapy, we can conclude that noncoplanar or coplanar IMRT were optimal in this study as IMRT plans provided homogeneous and conformal target coverage, skin sparing, and relatively short treatment delivery time.

  2. Coupling Between Microstrip Lines and Finite Ground Coplanar Lines Embedded in Polyimide Layers for 3D-MMICs on Silicon

    Science.gov (United States)

    Ponchak, G. E.; Bushyager, N.; Papapolymerou, J.; Tentzeris, E. M.; Laskar, J.

    2002-01-01

    Three-dimensional circuits built upon multiple layers of polyimide are required for constructing Si/SiGe monolithic microwave/mm-wave integrated circuits on CMOS (low resistivity) Si wafers. It is expected that these circuits will replace the ones fabricated on GaAs and reduce the overall system cost. However, the closely spaced transmission lines that are required for a high-density circuit environment are susceptible to high levels of cross-coupling, which degrades the overall circuit performance. In this paper, theoretical and experimental results on coupling and ways to reduce it are presented for two types of transmission lines: a) the microstrip line and b) the Finite Ground Coplanar (FGC) line. For microstrip lines it is shown that a fence of metalized via-holes can significantly reduce coupling, especially in the case when both lines are on the same polyimide layer or when the shielding structure extends through several polyimide layers. For closely spaced microstrip lines, coupling is lower for a metal filled trench shield than a via-hole fence. Coupling amongst microstrip lines is dependent on the ratio of line separation to polyimide thickness and is primarily due to magnetic fields. For FGC lines it is shown that they have in general low coupling that can be reduced significantly when there is even a small gap between the ground planes of each line. FGC lines have approximately 8 dB lower coupling than coupled coplanar waveguides (CPW). In addition, forward and backward characteristics of the FGC lines do not resemble those of other transmission lines such as microstrip. Therefore, the coupling mechanism of the FGC lines is different compared to thin film microstrip lines.

  3. SU-E-T-647: Plan Quality in Computerized Non-Coplanar IMRT Beam Angle Optimization is Highly Dependent on the Extent of the Beam direction Search Space.

    Science.gov (United States)

    Voet, P; Rossi, L; Breedveld, S; Aluwini, S; Heijmen, B

    2012-06-01

    To investigate the relationship between plan quality and the extent of the beam direction search space in computerized beam angle selection for generating optimal (non-coplanar) IMRT plans for prostate SBRT with dose distributions simulating HDR brachytherapy. iCycle (1) was used to investigate the relationship between plan quality and the extent of the set of beam directions available for plan generation. For a group of 10 prostate patients, optimal plans were generated for 5 direction search spaces. For coplanar treatments (CP set), 72 orientations were available for selection (separation 5°). The fully non-coplanar set (F-NCP) included the CP directions plus 430 directions spread over the sphere. The CK set contained the directions available at the robotic Cyberknife unit. CK+ and CK++ were extensions of CK to investigate some of its characteristics. Generated plans were in accordance with our clinical SBRT protocol for Cyberknife treatment, delivering 4 fractions of 9.5 Gy. Adequate PTV coverage had the highest priority. Reduction of rectum dose was the highest OAR priority. The mean PTV coverage (V95) of all SBRT plans was 99% ï,± 0.9% (1 SD). F-NCP plans had most favorable OAR dose parameters, while for coplanar plans OAR doses were highest. Compared to coplanar treatment, rectum Dmean/V60 were 25% / 37% and 19% / 21% lower in F-NCP and CK plans. Higher rectum dose for the Cyberknife set compared to F-NCP was not caused by a lack of posterior beams for Cyberknife. For all search spaces, reduction in OAR dose only leveled off with > 20 beams in the plans (for CP, rectum V60 in 25 beam plans was reduced by 64% compared to 11 beams). In the non-coplanar set-ups, there was a preference for beams with a (large) lateral component. Plan quality clearly improved with the extent of the beam direction search space (coplanar worst), and the number of beam directions in the plan (25 clearly better than 11).(1) Breedveld S, Storchi P, Voet P, Heijmen B, Med Phys 2012

  4. Enantioselective determination of chiral toxaphene congeners in laying hens and eggs using multidimensional high-resolution gas chromatography.

    Science.gov (United States)

    Hamed, Sobhy; Leupold, Guenter; Ismail, Ahmed; Parlar, Harun

    2005-09-07

    A total of 22 chiral toxaphene congeners were analyzed in organ tissues and eggs of laying hens after they had been fed with food spiked with technical toxaphene. For the analysis, multidimensional high-resolution gas chromatography using a chiral column coated with randomly silylated heptakis(O-tert-butyldimethylsilyl)-beta-cyclodextrin, electron capture detection, and valveless "live column switching" technique was applied. The analytical results were additionally confirmed with mass spectral data, recorded in electron-capture negative ionization mode with selected-ion monitoring mass spectrometry. During both the feeding period of the laying hens with toxaphene-contaminated food (38 weeks, accumulation phase) and the following subsiding period without toxaphenes (another 14 weeks, decontamination phase), organs (liver, kidney, skin/fat), blood, meat, and eggs of the hens served as model matrices for toxaphene uptake. The enantiomeric ratios (ERs) of congeners 26, 31, 32, 40, 41, 42(a+b), 44, 50, and 62--known as the most important components of technical toxaphene occurring in the environment--could be analytically determined. Significant differences were observed with respect to their initial racemic ratios. On the basis of their chemical structures, the metabolic pathways of some congeners could be explained. Astonishingly, some of the toxaphenes applied as racemates could merely be found as single enantiomers at the end of the feeding program, for example, congener 32 in blood and meat samples or congener 44, especially in organ tissues, which showed ERs of zero or infinity. The findings of this study impressively emphasize that it is essential to isolate and analyze individual toxaphene enantiomers in food and biota tissues to be capable of evaluating their toxicity and metabolization more specifically.

  5. [Analysis of toxaphene and its eight congeners in sediment and fish tissue by gas chromatography-negative ion mass spectrometry].

    Science.gov (United States)

    Lao, Wenjian

    2013-07-01

    Toxaphene quantification incorporating gas chromatography/negative chemical ionization mass spectrometry (GC/NCI-MS) offers improved sensitivity and specificity. The U. S. Environmental Protection Agency (USEPA) recently released a GC/NCI-MS method (Method 8276) for the measurement of technical toxaphene and eight specific congeners (Hx-Sed, Hp-Sed, P26, P41, P40, P44, P50 and P62). However, there is still lack of a practical and complete analytical method including sample extraction, clean up, instrumental analysis, and data analysis. The goal of this work was to develop a ready-to-use method for the quantification of total toxaphene and the eight congeners. Sediment and salmon fish tissue were selected as sample matrices and extracted with methylene chloride using an accelerated solvent extraction system. The sample extracts were cleaned up with active copper powder or gel permeation chromatography, and finally silica/alumina combination column. Separation was performed on a DB-XLB column. GC/NCI-MS was operated under selected ion monitoring mode with an identical set of confirmation and quantitation ions for total toxaphene and the eight congeners. Oxygen reaction of polychlorinated biphenyls (PCB) was monitored by PCB204, an internal calibration standard, and the reaction level was kept below 1%. Average relative response factors were used in quantitation. Quantitation of total toxaphene employed the sum of all detectable (S/N > or = 3) 6-C1 to 10-Cl homolog peak areas, while the individual congeners were quantified followed the standard procedures for single analytes. Multi-point calibration solutions ranged from 0. 5 (5 for P62) to 500 microg/L for the individual congeners, and 50 to 500 microg/L for technical toxaphene, with the lowest calibration levels as lower limits of quantitation. Average congener recovery was (90.8 +/- 17.4)% (n =10) in spiked sediment with relative standard deviations of 5.4% - 12.8% (n =10), underscoring an excellently accurate and

  6. Non-coplanar polychlorinated biphenyls (PCBs) are direct agonists for the human pregnane-X receptor and constitutive androstane receptor, and activate target gene expression in a tissue-specific manner

    Energy Technology Data Exchange (ETDEWEB)

    Al-Salman, Fadheela; Plant, Nick, E-mail: N.Plant@Surrey.ac.uk

    2012-08-15

    The polychlorinated biphenyl group possesses high environmental persistence, leading to bioaccumulation and a number of adverse effects in mammals. Whilst coplanar PCBs elicit their toxic effects through agonism of the aryl hydrocarbon receptor; however, non-coplanar PCBs are not ligands for AhR, but may be ligands for members of the nuclear receptor family of proteins. To better understand the biological actions of non-coplanar PCBs, we have undertaken a systematic analysis of their ability to activate PXR and CAR-mediated effects. Cells were exposed to a range of non-coplanar PCBs (99, 138, 153, 180 and 194), or the coplanar PCB77: Direct activation of PXR and CAR was measured using a mammalian receptor activation assay in human liver cells, with rifampicin and CITCO used as positive controls ligands for PXR and CAR, respectively; activation of target gene expression was examined using reporter gene plasmids for CYP3A4 and MDR1 transfected into liver, intestine and lung cell lines. Several of the non-coplanar PCBs directly activated PXR and CAR, whilst the coplanar PCB77 did not. Non-coplanar PCBs were also able to activate PXR/CAR target gene expression in a substitution- and tissue-specific manner. Non-coplanar PCBs act as direct activators for the nuclear receptors PXR and CAR, and are able to elicit transcriptional activation of target genes in a substitution- and tissue-dependent manner. Chronic activation of PXR/CAR is linked to adverse effects and must be included in any risk assessment of PCBs. -- Highlights: ► Several Non-coplanar PCBs are able to directly activate both PXR and CAR in vitro. ► PCB153 is the most potent direct activator of PXR and CAR nuclear receptors. ► Non-coplanar PCB activation of CYP3A4/MDR1 reporter genes is structure-dependent. ► Non-coplanar PCB activate CYP3A4/MDR1 reporter genes in a tissue-dependent. ► PCB153 is the most potent activator of PXR/CAR target gene in all tissues.

  7. An invasive plant alters pollinator-mediated phenotypic selection on a native congener.

    Science.gov (United States)

    Beans, Carolyn M; Roach, Deborah A

    2015-01-01

    • Recent studies suggest that invasive plants compete reproductively with native plants by reducing the quantity or quality of pollinator visits. Although these studies have revealed ecological consequences of pollinator-mediated competition between invasive and native plants, the evolutionary outcomes of these interactions remain largely unexplored.• We studied the ecological and evolutionary impact of pollinator-mediated competition with an invasive jewelweed, Impatiens glandulifera, on a co-occurring native congener, I. capensis. Using a pollinator choice experiment, a hand pollination experiment, and a selection analysis, we addressed the following questions: (1) Do native pollinators show preference for the invasive or native jewelweed, and do they move between the two species? (2) Does invasive jewelweed pollen inhibit seed production in the native plant? (3) Does the invasive jewelweed alter phenotypic selection on the native plant's floral traits?• The pollinator choice experiment showed that pollinators strongly preferred the invasive jewelweed. The hand pollination experiment demonstrated that invasive pollen inhibited seed production in the native plant. The selection analysis showed that the presence of the invasive jewelweed altered phenotypic selection on corolla height in the native plant.• Invasive plants have the potential to alter phenotypic selection on floral traits in native plant populations. If native plants can evolve in response to this altered selection pressure, the evolution of floral traits may play an important role in permitting long-term coexistence of native and invasive plants. © 2015 Botanical Society of America, Inc.

  8. Hybridization and reproductive isolation between diploid Erythronium mesochoreum and its tetraploid congener E. albidum (Liliaceae).

    Science.gov (United States)

    Roccaforte, Kathy; Russo, Sabrina E; Pilson, Diana

    2015-06-01

    Polyploidy has played an important role in angiosperm diversification, but how polyploidy contributes to reproductive isolation remains poorly understood. Most work has focused on postzygotic reproductive barriers, and the influence of ploidy differences on prezygotic barriers is understudied. To address these gaps, we quantified hybrid occurrence, interspecific self-compatibility differences, and the contributions of multiple pre- and postzygotic barriers to reproductive isolation between diploid Erythronium mesochoreum (Liliaceae) and its tetraploid congener Erythronium albidum. Reproductive isolation between the study species was nearly complete, and naturally occurring hybrids were infrequent and largely sterile. Although postzygotic barriers effected substantial reproductive isolation when considered in isolation, the study species' spatial distributions and pollinator assemblages overlapped little, such that interspecific pollen transfer is likely uncommon. We did not find evidence that E. albidum and E. mesochoreum differed in mating systems, indicating that self-incompatibility release may not have fostered speciation in this system. Ultimately, we demonstrate that E. albidum and E. mesochoreum are reproductively isolated by multiple, hierarchically-operating barriers, and we add to the currently limited number of studies demonstrating that early acting barriers such as pollinator-mediated isolation can be important for effecting and sustaining reproductive isolation in diploid-polyploid systems.

  9. Sorption behaviors of a persistent toxaphene congener on marine sediments under different physicochemical conditions.

    Science.gov (United States)

    Soubaneh, Youssouf Djibril; Gagné, Jean-Pierre; Lebeuf, Michel; Gouteux, Bruno; Nikiforov, Vladimir; Awaleh, Mohamed Osman

    2014-11-01

    Sorptive processes are important parameters affecting the mobility, availability and fate of persistent organic pollutants (POPs), such as toxaphene, in aquatic systems. The sorption and desorption behaviors of the B7-1450, a stable toxaphene congener in environment, on marine sediment was studied under different temperature and salinity conditions to better understand the B-1450 distribution in estuarine systems. The data were fitted to different sorption models to characterize sorption behaviors by evaluating sorption coefficients and sequestrated fraction of B7-1450 on sediments. High carbon-normalized sorption coefficients (Koc) of the B7-1450 were observed with values ranging from 3.2×104 to 6.0×104 mL g(-1) under experimental conditions. The data showed an increase of B7-1450 sorption coefficients with the salinity and a decrease with temperature. These investigations indicate that B7-1450 is three times more sequestred on sediments in cold (2°C, 30 psu) than in warm marine conditions (20°C, 30 psu). These results suggest that the mobility and bioavailable of B7-1450 or other POPs from the sediments could be less important in cold marine comparatively in warm marine and warm freshwater media. As a result of climate changes, the warming of mid and high latitudes coastal waters could enhance the mobility of POPs.

  10. Synergistic Interactions of Eugenol-tosylate and Its Congeners with Fluconazole against Candida albicans.

    Science.gov (United States)

    Ahmad, Aijaz; Wani, Mohmmad Younus; Khan, Amber; Manzoor, Nikhat; Molepo, Julitha

    2015-01-01

    We previously reported the antifungal properties of a monoterpene phenol "Eugenol" against different Candida strains and have observed that the addition of methyl group to eugenol drastically increased its antimicrobial potency. Based on the results and the importance of medicinal synthetic chemistry, we synthesized eugenol-tosylate and its congeners (E1-E6) and tested their antifungal activity against different clinical fluconazole (FLC)- susceptible and FLC- resistant C. albicans isolates alone and in combination with FLC by determining fractional inhibitory concentration indices (FICIs) and isobolograms calculated from microdilution assays. Minimum inhibitory concentration (MIC) results confirmed that all the tested C. albicans strains were variably susceptible to the semi-synthetic derivatives E1-E6, with MIC values ranging from 1-62 μg/ml. The test compounds in combination with FLC exhibited either synergy (36%), additive (41%) or indifferent (23%) interactions, however, no antagonistic interactions were observed. The MICs of FLC decreased 2-9 fold when used in combination with the test compounds. Like their precursor eugenol, all the derivatives showed significant impairment of ergosterol biosynthesis in all C. albicans strains coupled with down regulation of the important ergosterol biosynthesis pathway gene-ERG11. The results were further validated by docking studies, which revealed that the inhibitors snugly fitting the active site of the target enzyme, mimicking fluconazole, may well explain their excellent inhibitory activity. Our results suggest that these compounds have a great potential as antifungals, which can be used as chemosensitizing agents with the known antifungal drugs.

  11. Holographic quantitative structure-activity relationship for prediction of the toxicity of polybrominated diphenyl ether congeners

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Polybrominated diphenyl ether congeners (PBDEs) might activate the AhR (aromatic hydrocarbon receptor) signal transduction,and thus might have an adverse effect on the health of humans and wildlife. Because of the limited experimental data,it is important and necessary to develop structure-based models for prediction of the toxicity of the compounds. In this study,a new molecular structure representation,molecular hologram,was employed to investigate the quantitative relationship between toxicity and molecular structures for 18 PBDEs. The model with the significant correlation and robustness (r2 = 0.991,q2LOO = 0.917) was developed. To verify the robustness and prediction capacity of the derived model,14 PBDEs were randomly selected from the database as the training set,while the rest were used as the test set. The results generated under the same modeling conditions as the optimal model are as follows:r2 = 0.988,q2LOO = 0.598,r2pred = 0.955,and RMSE (root-mean-square of errors) = 0.155,suggesting the excellent ability of the derived model to predict the toxicity of PBDEs. Furthermore,the structural features and molecular mechanism related to the toxicity of PBDEs were explored using HQSAR color coding.

  12. The hemodynamic effects of ibopamine, a dopamine congener, in patients with congestive heart failure.

    Science.gov (United States)

    Leier, C V; Ren, J H; Huss, P; Unverferth, D V

    1986-01-01

    Ten patients with congestive heart failure underwent noninvasive and invasive hemodynamic testing before and sequentially after the administration of ibopamine to determine the cardiovascular effects of this oral dopamine congener. Single doses of 200, 400 and 600 mg were administered to all patients and 5 repeated doses of 200 or 400 mg were studied in 8. Hemodynamic effects occurred as early as 30 minutes and lasted up to 4 hours after dosing. In general, ibopamine elicited statistically significant dose-related increases in cardiac output and reductions in the derived resistance of the systemic and pulmonary circulations. A biphasic response in central and peripheral pressures was observed; up to 1 hour after administration, ibopamine elevated mean right and left atrial pressures and pulmonary and systemic arterial pressures with a significant reduction of these measurements beyond 1 hour. It did not alter heart rate. Repeated doses qualitatively affected hemodynamics similar to the initial dose and did not appear to be accompanied by short-term tolerance. While oral ibopamine elicits some favorable hemodynamic effects in humans with cardiac failure, the biphasic hemodynamic response is generally undesirable in the majority of these patients.

  13. Congener specific determination of toxaphene residues in fish liver oil using gas chromatography coupled to ion trap MS/MS.

    Science.gov (United States)

    Bernardo, F J Guzmán; Fernández, M A; González, M J

    2005-10-01

    A new approach to the determination of six toxaphene congeners in edible stuff has been accomplished. The analytical procedure presented in this paper involves a single-step cleanup process prior to the analysis. A solution containing three (13)C labelled polychlorinated biphenyls was used as internal standard and tetrachloronaphtalene was used as injection standard. The analytical technique used was gas chromatography coupled to ion trap mass spectrometry detector in MS/MS mode. The parameters affecting the successive fragmentations were discussed and optimized. The limits of detection ranged from 2 to 49pg microl(-1). The toxaphene congeners were determined in two different fish liver oil pills sold in Spain as a supplementary vitamin support.

  14. Genetics of Bone Mineralization and Morphology in Inbred Mice: Analysis of the HcB/Dem Recombinant Congenic Strains

    Science.gov (United States)

    2005-04-01

    data for parameters with skewed distil- 3- PONT BEND MODULUS butions. Results of this analysis are summarized in Table 2. Ir TT . We used these data to...the pathogenesis of osteoporosis. I Bone Miner Res 9:739- [be murine strength is achieved. 743. 1002 YERSHOV ET AL. 16. Demant P, Hart AA 1986...Recombinant congenic strains--a 37. Linder E, Schork N 1994 Genetic dissection of complex traits. new tool for analyzing genetic traits determined by more than

  15. Determining indicator toxaphene congeners in soil using comprehensive two-dimensional gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zhu, Shuai; Gao, Lirong; Zheng, Minghui; Liu, Huimin; Zhang, Bing; Liu, Lidan; Wang, Yiwen

    2014-01-01

    Toxaphene, which is a broad spectrum chlorinated pesticide, is a complex mixture of several hundred congeners, mainly polychlorinated bornanes. Quantifying toxaphene in environmental samples is difficult because of its complexity, and because each congener has a different response factor. Toxaphene chromatograms acquired using one-dimensional gas chromatography (1DGC) show that this technique cannot be used to separate all of the toxaphene congeners. We developed and validated a sensitive and quantitative method for determining three indicator toxaphene congeners in soil using an isotope dilution/comprehensive two-dimensional gas chromatography-tandem mass spectrometry (GC × GC-MS). The samples were extracted using accelerated solvent extraction, and then the extracts were purified using silica gel columns. (13)C₁₀-labeled Parlar 26 and 50 were used as internal standards and (13)C₁₀-labeled Parlar 62 was used as an injection standard. The sample extraction and purification treatments and the GC × GC-MS parameters were optimized. Subsequently the samples were determined by GC × GC-MS. The limits of detection for Parlar 26, 50, and 62 were 0.6 pg/g, 0.4 pg/g, and 1.0 pg/g (S/N=3), respectively, and the calibration curves had good linear correlations between 50 and 1000 μg/L (r(2)>0.99). Comprehensive two-dimensional GC gave substantial improvements over one-dimensional GC in the toxaphene analysis. We analyzed soil samples containing trace quantities of toxaphene to demonstrate that the developed method could be used to analyze toxaphene in environmental samples.

  16. A divergent approach to the synthesis of simplexides and congeners via a late-stage olefin cross-metathesis reaction.

    Science.gov (United States)

    Li, Jiakun; Li, Wei; Yu, Biao

    2013-08-14

    Simplexides constitute a unique group of immunosuppressive glycolipids that demonstrate antiproliferative activities against activated T-cell lymphocytes via a unique non-cytotoxic inhibition. To investigate the structure-activity relationship of the varied long-chain secondary alcohols on simplexides, we developed an efficient and divergent route to the synthesis of simplexides and congeners, taking advantage of a late-stage olefin cross-metathesis reaction.

  17. Predicting the Congener-Specific Environmental Behaviour of Perfluorinated Acid Contaminants Using Semi-Empirical Computational Methods

    OpenAIRE

    Sierra Rayne; Kaya Forest; Ken J. Friesen

    2008-01-01

    Perfluorinated acids (PFAs) are contaminants detected worldwide in a range of abiotic and biotic environmental matrices. The two major classes of PFAs include the perfluorinated carboxylic acids (PFCAs) and perfluorinated sulfonic acids (PFSAs), both of which are considered persistent and potentially bioaccumulative. Current research and regulatory efforts are focussed on the straight-chain members of each PFA class and homologue group, primarily because these congeners are the major componen...

  18. Seasonal variability of polychlorinated biphenyls (PCBs) and polychlorinated diphenyl ethers (PBDEs) congener profiles in butter in Poland: dietary risk evaluation.

    Science.gov (United States)

    Roszko, Marek; Szymczyk, Krystyna; Rzepkowska, Małgorzata; Jędrzejczak, Renata

    2014-01-01

    Various statistical methods have been employed to analyse in details seasonal diversification of polychlorinated biphenyl (PCB)/polybrominated diphenyl ether (PBDE) congener profiles found in butter fat. The variability of the PCB/PBDE congener profiles indicates the presence of various sources of the milk fat contamination. The obtained results suggest that the environmental chemical background has the highest share in the contamination sources pattern. Ion trap mass spectrometry coupled to high-resolution gas chromatography with semi-permeable membrane dialysis sample cleanup was used for determination of PCBs and PBDEs in milk fat. Determined butter fat PCB profiles were similar to the profiles characteristic for Aroclor 1254 technical mixture. Our data indicate that dietary intake of PCB/PBDE with milk and milk products may be estimated to be about 717.5 pg kg b.w.(-1) day(-1) for six-indicator PCBs, 0.329 (equivalent toxicity, TEQ) pg kg b.w.(-1) day(-1) for 12 DL PCBs and 50 pg kg b.w.(-1) day(-1) for PBDEs (sum of 14 congeners).

  19. Polychlorinated biphenyl source attribution in Green Bay, Wisconsin, USA, using multivariate similarity among congener profiles in sediment samples.

    Science.gov (United States)

    Cacela, Dave; Beltman, Douglas J; Lipton, Joshua

    2002-08-01

    Polychlorinated biphenyl (PCB) congener concentrations measured in 1,189 sediment samples from Green Bay (MI/WI, USA), Lake Michigan (MI/WI, USA), and the Fox River (WI, USA) were analyzed statistically to evaluate whether PCB congener profiles in outer Green Bay are more similar to those observed in inner Green Bay or Lake Michigan. Similarities among PCB profiles were assessed with complementary multivariate analysis techniques: Principal component analysis (PCA), cluster analysis, and classification trees. The PCA indicated that profiles in outer Green Bay are distinct from those of inner Green Bay or Lake Michigan but are more similar to those of inner Green Bay. The outer bay profiles are dissimilar to profiles that would result from a simple process of mixing contaminated sediments from the inner bay with Lake Michigan sediments and, therefore, support the conclusion that contaminants in outer Green Bay come from discharges of the Fox River. Several classification trees based on small sets of congener proportions defined simple rules that consistently distinguished the regional profiles. Application of these rules to classify the outer bay samples suggests that the profiles of less than 7% of outer bay samples are similar to Lake Michigan profiles. These results are interpreted with respect to physical transport and chemical weathering processes that may account for the observed differences.

  20. Isolation of pure enantiomers of Toxaphene congeners via hydrochlorination and chlorination of Pinene and composition of Soviet polychloropinene

    Energy Technology Data Exchange (ETDEWEB)

    Nikiforov, V.; Trukhin, A.; Kruchkov, F.; Kiprianova, A.; Miltsov, S. [Sankt-Peterburgskij Univ. (Russian Federation). Dept. of Chemistry; Kallenborn, R. [NILU, Kjeller (Norway)

    2004-09-15

    Toxaphene is an insecticidal mixture, produced by the controlled photochlorination of camphene1. In the USSR similar insecticide - Polychloropinene was produced by chlorination of {alpha}-pinene with AIBN (azobisisobutyronitrile) as initiator. Natural camphene occurs in different essential oils in (+)-form as well as (-)-form. Production of artificial camphene starts from natural {alpha}-pinene, which is also chiral. All noted types of camphene are used for toxaphene synthesis by different manufacturers. Some congeners in selected samples of technical Toxaphene were shown to have small deviations from racemic distribution. Nevertheless, there is no information about any enantiomerically pure congeners of toxaphene. The amount of Polychloropinene produced in the USSR is estimated to be 160 thousand tons, which is a significant contribution into the total global production. Unfortunately, there is no traceable sample of Soviet Polychloropinene available. In the present work we report on the preparation of artificial model Polychloropinene mixtures with different content of chlorine in an attempt to find the difference between Toxaphene and Soviet Polychloropinene. Another goal of our research project is to prepare pure enantiomers of important Toxaphene congeners, to establish their configuration and thus to provide more opportunities to enantiomerspecific environmental analysis of Toxaphene residues.

  1. Validation of Simple Sequence Length Polymorphism Regions of Commonly Used Mouse Strains for Marker Assisted Speed Congenics Screening

    Directory of Open Access Journals (Sweden)

    Channabasavaiah B. Gurumurthy

    2015-01-01

    Full Text Available Marker assisted speed congenics technique is commonly used to facilitate backcrossing of mouse strains in nearly half the time it normally takes otherwise. Traditionally, the technique is performed by analyzing PCR amplified regions of simple sequence length polymorphism (SSLP markers between the recipient and donor strains: offspring with the highest number of markers showing the recipient genome across all chromosomes is chosen for the next generation. Although there are well-defined panels of SSLP makers established between certain pairs of mice strains, they are incomplete for most strains. The availability of well-established marker sets for speed congenic screens would enable the scientific community to transfer mutations across strain backgrounds. In this study, we tested the suitability of over 400 SSLP marker sets among 10 mouse strains commonly used for generating genetically engineered models. The panel of markers presented here can readily identify the specified strains and will be quite useful in marker assisted speed congenic screens. Moreover, unlike newer single nucleotide polymorphism (SNP array methods which require sophisticated equipment, the SSLP markers panel described here only uses PCR and agarose gel electrophoresis of amplified products; therefore it can be performed in most research laboratories.

  2. Distribution and uptake of key polychlorinated biphenyl and polybrominated diphenyl ether congeners in benthic infauna relative to sediment organic enrichment.

    Science.gov (United States)

    Burd, Brenda J; Macdonald, Tara A; Macdonald, Robie W; Ross, Peter S

    2014-10-01

    As part of a broader study of budgets, transport, and bioaccumulation of persistent organic contaminants in the Strait of Georgia, Canada, matching samples of sediment and bulk benthos were collected near two marine sewage outfalls, two large urban harbours, and background areas. Samples were analyzed for polychlorinated biphenyl (PCB) and polybrominated diphenyl ether (PBDE) congeners. We present data for those congeners that fell within the top six rankings by concentration (23 PCBs and 10 PBDEs) within at least one of the environmental media measured in other studies (air, water, sediments, benthos, pelagic biota). Multifactor regression analyses incorporating sediment characteristics (total organic carbon, fines) predicted uptake (r (2) = 0.74 to 0.98, p supply food and sediments with PCB concentrations similar to ambient sediments. However, organic enrichment of sediments near outfalls clearly enhanced PCB uptake by benthos, probably due to greatly increased biomass turnover near these sources. Data suggest there to be an initial reservoir of PCBs in newly settled juvenile benthos, which is much less evident for PBDEs. This is likely a consequence of the ecosystem-wide distribution of legacy PCBs but not the more current-use PBDEs. Congener-uptake patterns were dependent on source and input dynamics, feeding methods, and contaminant metabolism or debromination, particularly of deca-BDE.

  3. Congener-specific accumulation and trophic transfer of polychlorinated biphenyls in spider crab food webs revealed by stable isotope analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bodin, N. [IFREMER, DCN-BE, Technopole Brest-Iroise, Pointe du Diable, 29280 Plouzane (France); LPTC-UMR 5472 CNRS, Universite de Bordeaux 1, 351 cours de la Liberation, 33400 Talence (France)], E-mail: bodin.nathalie@caramail.com; Le Loc' h, F. [IRD, UR 070 RAP, Centre de Recherche Halieutique, Avenue Jean Monnet, B.P. 171, 34203 Sete Cedex (France); Caisey, X.; Le Guellec, A.-M.; Abarnou, A.; Loizeau, V. [IFREMER, DCN-BE, Technopole Brest-Iroise, Pointe du Diable, 29280 Plouzane (France); Latrouite, D. [IFREMER, DCB-STH, Technopole Brest-Iroise, Pointe du Diable, 29280 Plouzane (France)

    2008-01-15

    Polychlorobiphenyls (PCB) and stable isotopes ({delta}{sup 15}N and {delta}{sup 13}C) were analyzed in the spider crab (Maja brachydactyla) food web from the Iroise Sea (Western Brittany) and the Seine Bay (Eastern English Channel). PCB concentrations were all significantly higher in organisms from the Seine Bay than those from the Iroise Sea. PCB patterns were strongly related to the feeding mode of the species, and increased influence of higher chlorinated congeners was highlighted with trophic position of the organisms. PCB concentrations (lipid normalized) were significantly related to the isotopically derived trophic level (TL) in spider crab food webs. The highest trophic magnification factors (TMFs) were calculated for the congeners with 2,4,5-substitution, and were lower in the Seine Bay compared to the Iroise Sea. The confrontation of PCB and TL data also revealed biotransformation capacity of decapod crustaceans for specific congeners based on structure-activity relations. - The influence of feeding mode and trophic position on the fate of PCBs in spider crab food webs is discussed by using a stable isotopic approach.

  4. Fabrication of Buried Co-Planar Metal-Insulator-Metal Nanojunctions with a Gap Lower than 10nm

    Science.gov (United States)

    Rousset, V.; Joachim, C.; Itoua, S.; Rousset, B.; Fabre, N.

    1995-12-01

    An improvement of a process to fabricate co-planar metal-insulator-metal nanojunctions is presented to reach a gap length much lower than 10 nm using a 20 keV e-beam and an AuPd lift-off. The electrodes of the nanojunction are less than 100 nm in width and are buried in the SiO2 substrate. For the 8 nm nanojunctions, the gap is still filled with SiO2 if care is taken about the SiO2 etching step of the process. Un procédé de fabrication est proposé pour obtenir des nanojonctions métal-isolant-métal co-planaires d'une largeur d'isolant bien inférieure à 10nm en utilisant un masqueur électronique à 20keV et un “lift-off” à l'or-palladium. Les électrodes de la nanojonction enterrées dans la silice ont une largeur de moins de 100nm et sont distantes de 8nm. En optimisant l'étape de sous gravure, il est possible de conserver de la silice comme isolant entre les électrodes.

  5. SiGe BiCMOS balanced transmission line based on coplanar waveguide and split ring resonator

    Science.gov (United States)

    Serrano, Enrique; Borja, Alejandro L.; Boccia, Luigi; Cascon, Joaquin; Ibrahim, Safwat; Calzona, D.; Amendola, G.

    2016-06-01

    In this work, the design of a right-/left-handed composite transmission line implementation with passband characteristics is demonstrated on 0.13 µm silicon-germanium bipolar CMOS (SiGe BiCMOS) technology. The proposed structure is formed by a shorted coplanar waveguide transmission line loaded with split ring resonators (SRRs). As it will be shown, by controlling the geometry of the SRRs as well as their electric coupling with the host line, it is possible to achieve a balanced passband response with widespread bandwidth at millimeter wave frequencies. Besides, this paper introduces a configuration that allows to significantly lower the resonant frequency of the SRRs by loading the rings with Metal-Insulator-Metal capacitors. It will be illustrated how this approach allows to reduce the center band frequency of about 40% preserving the balanced behavior and without increasing the resonator size. Finally, the proposed design was experimentally validated with a prototype exhibiting an extended passband with a fractional bandwidth of 19.3% and -3.2 dB of insertion loss around the central frequency of 60 GHz. The use of these transmission lines can be foreseeing in high-capacity millimeter wave communication systems which require compact passband blocks integrated on chip.

  6. Discrimination of alpha particles in CdZnTe detectors with coplanar grid for the COBRA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Rebber, Henning [Universitaet Hamburg, Institut fuer Experimentalphysik, Luruper Chaussee 149, 22761 Hamburg (Germany); Collaboration: COBRA-Collaboration

    2016-07-01

    The aim of the COBRA experiment is the search for neutrinoless double beta decay using CdZnTe semiconductor detectors. A background rate in the order of 10{sup -3} counts per keV, kg and year is intended in order to be sensitive to a half-life larger than 10{sup 26} years. Measurements from a demonstrator setup and Monte Carlo simulations indicate that a large background component is due to alpha particles. These generate charge clouds of only few μm in diameter in the detector, leading to characteristic pulse features. Parameter-based cut criteria were developed to discriminate alpha events by means of their pulse shapes. The cuts were tested on data from alpha and beta irradiation of a (1 x 1 x 1) cm{sup 3} CdZnTe detector with coplanar grid. The pulse shapes of all event signals were read out by FADCs with a sampling rate of 100 MHz. The signals were reproduced by a detector simulation which hence was used to study the cuts for energies up to 3 MeV and different detector regions.

  7. Numerical and experimental modeling of liquid metal thin film flows in a quasi-coplanar magentic field

    Energy Technology Data Exchange (ETDEWEB)

    Morley, Neil B. [Univ. of California, Los Angeles, CA (United States)

    1994-01-01

    Liquid metal film protection of plasma-facing surfaces in fusion reactors is proposed in an effort to counter the adverse effects of high heat and particle fluxes from the burning plasma. Concerns still exist about establishing the required flow in presence of strong magnetic fields and plasma momentum flux typical of a reactor environment. In this work, the flow behavior of the film is examined under such conditions. Analysis of MHD equations as they apply to liquid metal flows with a free surface in the fully-developed limit was undertaken. Solution yields data for velocity profiles and uniform film heights vs key design parameters (channel size, magnetic field magnitude/orientation, channel slope, wall conductivity). These results are compared to previous models to determine accuracy of simplifying assumptions, in particular Hartmann averaging of films along {rvec B}. Effect of a plasma momentum flux on the thin films is also analyzed. The plasma momentum is strong enough in the cases examined to seriously upset the film, especially for lighter elements like Li. Ga performed much better and its possible use is bolstered by calculations. In an experiment in the MeGA-loop MHD facility, coplanar, wide film flow was found to be little affected by the magnetic field due to the elongated nature of the film. Both MHD drag and partial laminarization are observed, supporting the fully- developed film model predictions of the onset of MHD drag and duct flow estimations for flow laminarization.

  8. Effect of electron transport properties on unipolar CdZnTe radiation detectors: LUND, SpectrumPlus, and Coplanar Grid

    Energy Technology Data Exchange (ETDEWEB)

    Ralph B. James

    2000-01-07

    Device simulations of (1) the laterally-contacted-unipolar-nuclear detector (LUND), (2) the SpectrumPlus, (3) and the coplanar grid made of Cd{sub 0.9}Zn{sub 0.1}Te (CZT) were performed for {sup 137}Cs irradiation by 662.15 keV gamma-rays. Realistic and controlled simulations of the gamma-ray interactions with the CZT material were done using the MCNP4B2 Monte Carlo program, and the detector responses were simulated using the Sandia three-dimensional multielectrode simulation program (SandTMSP). The simulations were done for the best and the worst expected carrier nobilities and lifetimes of currently commercially available CZT materials for radiation detector applications. For the simulated unipolar devices, the active device volumes were relatively large and the energy resolutions were fairly good, but these performance characteristics were found to be very sensitive to the materials properties. The internal electric fields, the weighting potentials, and the charge induced efficiency maps were calculated to give insights into the operation of these devices.

  9. Investigation of the coplanar barrier discharge in synthetic air at atmospheric pressure by cross-correlation spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hoder, T [Department of Physical Electronics, Masaryk University, Kotlarska 2, Brno 611 37 (Czech Republic); SIra, M [Department of Physical Electronics, Masaryk University, Kotlarska 2, Brno 611 37 (Czech Republic); Kozlov, K V [Institute of Physics, Ernst-Moritz-Arndt University, Felix-Hausdorff-Str. 6, D-17489 Greifswald (Germany); Wagner, H-E [Institute of Physics, Ernst-Moritz-Arndt University, Felix-Hausdorff-Str. 6, D-17489 Greifswald (Germany)

    2008-02-07

    The barrier discharge in the coplanar arrangement operating in a single-filament mode was studied spectroscopically. The evolution of the discharge luminosity was measured by the technique of cross-correlation spectroscopy. The 1D-spatially and temporally resolved luminosities of the first negative (at 391.5 nm) and the second positive (at 337.1 nm) system of molecular nitrogen were recorded using the above-mentioned technique. A cathode-directed ionizing wave (IW) was clearly seen on the plot for radiation intensity at 337.1 nm. In addition to this, also observed was a wave of the enhanced electric field propagating over the anode. In this paper, the propagation of these waves is described and their velocities are determined. The discharge evolution is divided into three phases-the Townsend phase, the phase of the IWs propagation and the extinction phase. Since the above-mentioned luminosity distributions could be interpreted approximately as the electric field (for 391.5 nm) and the electron density (for 337.1 nm) distribution, the qualitative description of the discharge is made accordingly. All these parameters are compared with similar measurements of the volume discharge. Apart from this, an attempt to determine the reduced electric field is made according to the kinetic model.

  10. Phthalate esters and childhood asthma: A systematic review and congener-specific meta-analysis.

    Science.gov (United States)

    Li, Ming-Chieh; Chen, Chi-Hsien; Guo, Yue Leon

    2017-10-01

    Exposure to phthalate esters (PAEs) has been associated with childhood asthma, but the congener-specific effects of PAEs on childhood asthma were unclear. We aimed to systematically review and meta-analyze observational studies on the associations between specific effects of PAEs and the risk of childhood asthma. Relevant studies were identified by searching three databases up to October 20, 2016. The reference lists of the retrieved articles were also reviewed. We included observational studies that reported risk estimates with 95% confidence intervals (CIs) for the associations between phthalate exposure and the risk of childhood asthma. Fixed-effects models were generally applied to calculate pooled risk estimates. When heterogeneity was present, random-effects models were applied. A total of nine studies featuring 43 data points were included in our final meta-analyses. Results indicated that the benzyl butyl phthalate (BBzP) exposure had a significant association with the risk of childhood asthma. The Odd Ratios (ORs) were from 1.39 to 1.41 for different combination strategies. Subgroup analyses by different exposure period or samples used showed that prenatal exposure to BBzP had a stronger association with the risk of childhood asthma (OR = 1.38, 95% CI = 1.09-1.75), compared to those with postnatal exposure. Besides, the association was evident when the phthalate exposure was measured from dust samples. The OR for the associations between di-2-ethylhexyl phthalate (DEHP) in dust and childhood asthma was 2.71 (95% CI = 1.39-5.28), and 2.08 (95% CI = 1.10-3.92) for BBzP. Our study suggested a positive association between DEHP and BBzP exposure and childhood asthma. Future studies are warranted to identify the underlying mechanisms of the association. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Anti-plasmodial and anti-leishmanial activity of conformationally restricted pentamidine congeners.

    Science.gov (United States)

    Huang, Tien L; Vanden Eynde, Jean Jacques; Mayence, Annie; Donkor, Isaac O; Khan, Shabana I; Tekwani, Babu L

    2006-08-01

    A library of 52 pentamidine congeners in which the flexible pentyldioxy linker in pentamidine was replaced with various restricted linkers was tested for in-vitro activity against two Plasmodium falciparum strains and Leishmania donovani. The tested compounds were generally more effective against P. falciparum than L. donovani. The most active compounds against the chloroquine-sensitive (D6, Sierra Leone) and -resistant (W2, Indochina) strains of P. falciparum were bisbenzamidines linked with a 1,4-piperazinediyl or 1, 4-homopiperazinediyl moiety, with IC50 values (50% inhibitory concentration, inhibiting parasite growth by 50% in relation to drug-free control) as low as 7 nM based on the parasite lactate dehydrogenase assay. Seven piperazine-linked bisbenzamidines substituted at the amidinium nitrogens with a linear alkyl group of 3-6 carbons (22, 25, 27, 31) or cycloalkyl group of 4, 6 or 7 carbons (26, 32, 34) were more potent (IC50pentamidine as anti-plasmodial agents. The most active anti-leishmanial agents were 4,4'-[1,4-phenylenebis(methyleneoxy)]bisbenzenecarboximidamide (2, IC50 approximately 0.290 microM) and 1,4-bis[4-(1H-benzimidazol-2-yl)phenyl] piperazine (44, IC50 approximately 0.410 microM), which were 10- and 7-fold more potent than pentamidine (IC50 approximately 2.90 microM). Several of the more active anti-plasmodial agents (e.g. 2, 31, 33, 36-38) were also potent anti-leishmanial agents, indicating broad antiprotozoal properties. However, a number of analogues that showed potent anti-plasmodial activity (1, 18, 21, 22, 25-28, 32, 43, 45) were not significantly active against the Leishmania parasite. This indicates differential modes of anti-plasmodial and anti-leishmanial actions for this class of compounds. These compounds provide important structure-activity relationship data for the design of improved chemotherapeutic agents against parasitic infections.

  12. Congener-specific analysis of non-dioxin-like polychlorinated biphenyls in blood collected from 195 pregnant women in Sapporo City, Japan.

    Science.gov (United States)

    Todaka, Takashi; Hori, Tsuguhide; Hirakawa, Hironori; Kajiwara, Jumboku; Yasutake, Daisuke; Onozuka, Daisuke; Kato, Shizue; Sasaki, Seiko; Nakajima, Sonomi; Saijo, Yasuaki; Sata, Fumihiro; Kishi, Reiko; Iida, Takao; Furue, Masutaka

    2008-10-01

    We conducted a congener-specific analysis of non-dioxin-like polychlorinated biphenyls (non-dioxin-like PCBs) in blood collected between July 2002 and July 2004 from 195 pregnant women living in Sapporo City of Hokkaido Prefecture, Japan. The present study is one of the few studies in which full congener concentrations of non-dioxin-like PCBs have been measured in the blood of pregnant women. Of the 195 pregnant women, 101 were primipara (mean: 28.8 years, median: 28.0 years) and 94 were multipara (mean: 32.3 years, median: 33.0 years). Among the 197 non-dioxin-like PCB congeners, 58 congeners were identified in the blood of pregnant women. The arithmetic mean total concentrations of 58 non-dioxin-like PCB congeners in the blood of primiparous and multiparous mothers in Sapporo City were 42.2-329.3 (mean: 114.5, median: 98.6) and 31.5-258.0 (mean: 100.3, median: 91.4)ngg(-1)lipid, respectively. The results show that the contamination of non-dioxin-like PCBs in the blood of women has decreased compared to past levels in other domestic areas, in which the subject age was similar to that in this study. The results of the present study indicate that current levels of non-dioxin-like PCBs in the blood of Japanese women and can be used as baseline data for future temporal trends. The sums of the ratios of the concentrations of hexaCBs and heptaCBs to the total concentrations of 58 non-dioxin-like PCB congeners in the blood of primiparous and multiparous mothers were 78.5% and 77.7%, respectively. The hexaCBs ratios in the blood of primiparous and multiparous mothers were 45.4% and 44.7%, respectively. HexaCB-153 among hexaCBs congeners, the most abundant congener in the blood of primiparous and multiparous mothers, contributed approximately 22.0% and 21.8% to the total concentrations of 58 non-dioxin-like PCBs congeners that were measured in the blood, respectively. Among the non-dioxin-like PCB congeners measured in the present study, hexaCB-138, heptaCB-170, hepta

  13. Comparative metabolism, covalent binding and toxicity of BHT congeners in rat liver slices.

    Science.gov (United States)

    Reed, M; Fujiwara, H; Thompson, D C

    2001-11-28

    The metabolism, covalent binding and hepatotoxicity of butylated hydroxytoluene (BHT, 4-methyl-2,6-di-t-butylphenol) and two congeners (E-BHT, 4-ethyl-2,6-di-t-butylphenol; I-BHT, 4-isopropyl-2,6-di-t-butylphenol) were compared using precision-cut liver slices prepared from phenobarbital (PB)-treated male Sprague-Dawley rats. At equimolar concentrations (1 mM) BHT was the most toxic of the three compounds, causing an 80% decrease in cell viability over a 6 h incubation period. E-BHT was intermediate in toxicity while the isopropyl derivative was relatively nontoxic. Intracellular glutathione levels decreased prior to the onset of cytotoxicity. The cytochrome P450 inhibitor metyrapone completely inhibited the toxicity of all three compounds. The rates of metabolism of the three compounds to glutathione conjugates were compared in both PB-treated microsomes and PB-induced liver slices. In both models, the rate of formation was greatest for BHT, followed by E-BHT and I-BHT. Synthetic quinone methides (QMs) were prepared from each parent phenol and the rates of reactivity with three nucleophiles (water, methanol and glutathione) were compared. With each nucleophile, BHTQM was the most reactive, while I-BHTQM was the least reactive. Finally, covalent binding to protein was assessed in two ways. First, alkylation of an isolated model protein (bovine insulin) was measured in a microsomal enzyme activation system by mass spectrometry. Incubations with BHT produced the greatest extent of protein alkylation, followed by E-BHT, while no alkylation was observed with I-BHT. In the second system, covalent binding to cellular protein was assessed in rat liver PB microsomes and tissue slices by Western blotting using an antibody specific for the tert-butylphenol portion of the compounds. Binding was greatest for BHT, intermediate for E-BHT and could not be detected for I-BHT. The alkylation pattern for E-BHT was strikingly similar to that of BHT, suggesting that both compounds

  14. Coronaridine congeners inhibit human α3β4 nicotinic acetylcholine receptors by interacting with luminal and non-luminal sites.

    Science.gov (United States)

    Arias, Hugo R; Targowska-Duda, Katarzyna M; Feuerbach, Dominik; Jozwiak, Krzysztof

    2015-08-01

    To characterize the interaction of coronaridine congeners with human (h) α3β4 nicotinic acetylcholine receptors (AChRs), structural and functional approaches were used. The Ca(2+) influx results established that coronaridine congeners noncompetitively inhibit hα3β4 AChRs with the following potency (IC50's in μM) sequence: (-)-ibogamine (0.62±0.23)∼(+)-catharanthine (0.68±0.10)>(-)-ibogaine (0.95±0.10)>(±)-18-methoxycoronaridine [(±)-18-MC] (1.47±0.21)>(-)-voacangine (2.28±0.33)>(±)-18-methylaminocoronaridine (2.62±0.57 μM)∼(±)-18-hydroxycoronaridine (2.81±0.54)>(-)-noribogaine (6.82±0.78). A good linear correlation (r(2)=0.771) between the calculated IC50 values and their polar surface area was found, suggesting that this is an important structural feature for its activity. The radioligand competition results indicate that (±)-18-MC and (-)-ibogaine partially inhibit [(3)H]imipramine binding by an allosteric mechanism. Molecular docking, molecular dynamics, and in silico mutation results suggest that protonated (-)-18-MC binds to luminal [i.e., β4-Phe255 (phenylalanine/valine ring; position 13'), and α3-Leu250 and β4-Leu251 (leucine ring; position 9')], non-luminal, and intersubunit sites. The pharmacophore model suggests that nitrogens from the ibogamine core as well as methylamino, hydroxyl, and methoxyl moieties at position 18 form hydrogen bonds. Collectively our data indicate that coronaridine congeners inhibit hα3β4 AChRs by blocking the ion channel's lumen and probably by additional negative allosteric mechanisms by interacting with a series of non-luminal sites.

  15. Congenic mice provide evidence for a genetic locus that modulates spontaneous arthritis caused by deficiency of IL-1RA.

    Directory of Open Access Journals (Sweden)

    Yanhong Cao

    Full Text Available To understand the role of genetic factors involved in the development of spontaneous arthritis in mice deficient in IL-1 receptor antagonist protein (IL_1RA, we have identified a genomic region containing a major quantitative trait locus (QTL for this disease. The QTL is on chromosome 1 and appears to be the strongest genetic region regulating arthritis. To confirm the importance of the QTL and to identify potential candidate genes within it, we conducted speed congenic breeding to transfer the QTL region from DBA/1 mice that are resistant to spontaneous arthritis into BALB/c(-/- which are susceptible. Genetic markers along every chromosome were used to assist in the selection of progeny in each generation to backcross to BALB/c(-/-. By the 6th generation we determined that all of the chromosomes in the progeny were of BALB/c origin with the exception of portions of chromosome 1. At this stage we intercrossed selected mice to produce homozygous strains containing the genomic background of BALB/c(-/- except for the QTL region on chromosome 1, which was from DBA/1. We were able to establish two congenic strains with overlapping DBA/1 DNA segments. These strains were observed for the development of spontaneous arthritis. Both congenic strains were relatively resistant to spontaneous arthritis and had delayed onset and reduced severity of disease. The gene/s that regulates this major QTL would appear to be located in the region of the QTL that is shared by both strains. The common transferred region is between D1Mit110 and D1Mit209 on chromosome 1. We evaluated this region for candidate genes and have identified a limited number of candidates. Confirmation of the identity and precise role of the candidates will require additional study.

  16. Comparison of congener profiles of polychlorinated biphenyls between Yu-cheng children and a potential food source

    Energy Technology Data Exchange (ETDEWEB)

    Lung Shih-Chun Candice [Research Center for Environmental Changes, Academia Sinica, Taipei (Taiwan); Guo Yu-Liang Leon; Chang Ho-Yuan [Dept. of Environmental and Occupational Health, Coll. of Medicine, National Cheng Kung Univ., Tainan (Taiwan)

    2004-09-15

    In 1979, about two thousand people in central Taiwan were intoxicated by consumption of the rice oil that was contaminated with polychlorinated biphenyls (PCBs). This ''Yu-cheng'' incident was one of the two human tragedies which people ingested substantial amounts of PCBs within a short period of time. Some of the follow-up epidemiological studies focused on the children born to the exposed mothers, the Yu-cheng children, since they could be exposed to PCBs via breast-feeding or transplacental transfer. This report presents the results of the serum PCB levels of the 21 Yu-cheng children with a congener-specific analysis. On the other hand, fish consumption is thought to be the single most important exposure route to PCBs to the general public; thus, it is crucial to understand PCB exposure from fish consumption. In a separated study to assess PCB contamination in fish, PCB congener concentrations in tilapia (Oreochromis hybrids), the most popular fish in Taiwan, were evaluated. The consumption quantity of tilapia is the highest throughout the Island. It is mostly farmed in fresh water but can also be bred in saltwater. This report presents the concentrations and profiles in the serums of the Yu-cheng children. The congener profile is compared with PCB profile in the serum of Yu-cheng women reported previously and that in one of the potentially significant exposure source, tilapia, conducted in a separated work. Remarkable similarity between the profile of Yu-cheng children and that of the tilapia is revealed and discussed.

  17. Sex, BMI and age in addition to dietary intakes influence blood concentrations and congener profiles of dioxins and PCBs.

    Science.gov (United States)

    Knutsen, Helle K; Kvalem, Helen E; Haugen, Margaretha; Meltzer, Helle M; Brantsaeter, Anne L; Alexander, Jan; Päpke, Olaf; Liane, Veronica H; Becher, Georg; Thomsen, Cathrine

    2011-05-01

    The aim of this study was to i) characterize dietary polychlorinated biphenyls (PCBs) and dioxin exposure in consumers of fish from the PCB contaminated Lake Mjøsa in Norway ii) examine the influence of demographic factors on blood concentrations and congener composition of dioxins and PCBs, iii) characterize dietary sources and possible exposures above tolerable intake. Blood samples were analysed for dioxin-like (dl) compounds (PCDD/Fs and dl-PCBs) and non-dl-PCBs (ndl-PCBs). Dietary exposures were calculated using food frequency questionnaires (n=64). Men had higher median intake of dl-compounds than women (1.2 and 0.85 pg TEQ/kg bw/day), but similar blood concentrations (23.3 and 25.8, pg TEQ/g lipid weight (lw)). For non-dl-PCBs, intakes (6.5 and 4.5 ng/kg bw/day) and blood concentrations (381 and 224 ng/g lw) were higher in men than in women. Blood concentrations correlated with dietary intakes in men only. Increasing BMI and age elevated blood concentrations mainly in women. Men and women had different blood congener profiles, with a higher share of PCB-126 in women, despite similar dietary congener profiles. Eleven participants exceeded the tolerable intake for dl-compounds. Fish from Lake Mjøsa was the main dietary source. The higher influence of BMI and age for women than for men may have implications for risk assessment. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Gradient HPLC separation of dehydroepiandrosterone (DHEA) from its metabolites and biological congeners: role of tetrahydrofuran in the chromatographic mechanism.

    Science.gov (United States)

    Gergely, András; Horváth, Péter; Szász, György; Veress, Gábor

    2009-08-01

    A three-step gradient reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed for the separation of dehydroepiandrosterone (DHEA), its sulfate ester (DHEA-S), its three C7-oxidized metabolites (7alphaOH-DHEA, 7betaOH-DHEA, 7-keto-DHEA), and its biosynthetic congeners (androstenedione, testosterone, estradiol, pregnenolone). This new method allows the quantitative characterization of DHEA metabolism and biosynthetic transformation under given physiological, pathological, or therapeutically influenced circumstances. Tetrahydrofuran probably acts as a proton acceptor coadsorbent, while isopropanol behaves as a proton donor during the separation of testosterone, estradiol, and the stereoisomers of 7-OH-DHEA.

  19. Isolation of a Genomic Region Affecting Most Components of Metabolic Syndrome in a Chromosome-16 Congenic Rat Model.

    Directory of Open Access Journals (Sweden)

    Lucie Šedová

    Full Text Available Metabolic syndrome is a highly prevalent human disease with substantial genomic and environmental components. Previous studies indicate the presence of significant genetic determinants of several features of metabolic syndrome on rat chromosome 16 (RNO16 and the syntenic regions of human genome. We derived the SHR.BN16 congenic strain by introgression of a limited RNO16 region from the Brown Norway congenic strain (BN-Lx into the genomic background of the spontaneously hypertensive rat (SHR strain. We compared the morphometric, metabolic, and hemodynamic profiles of adult male SHR and SHR.BN16 rats. We also compared in silico the DNA sequences for the differential segment in the BN-Lx and SHR parental strains. SHR.BN16 congenic rats had significantly lower weight, decreased concentrations of total triglycerides and cholesterol, and improved glucose tolerance compared with SHR rats. The concentrations of insulin, free fatty acids, and adiponectin were comparable between the two strains. SHR.BN16 rats had significantly lower systolic (18-28 mmHg difference and diastolic (10-15 mmHg difference blood pressure throughout the experiment (repeated-measures ANOVA, P < 0.001. The differential segment spans approximately 22 Mb of the telomeric part of the short arm of RNO16. The in silico analyses revealed over 1200 DNA variants between the BN-Lx and SHR genomes in the SHR.BN16 differential segment, 44 of which lead to missense mutations, and only eight of which (in Asb14, Il17rd, Itih1, Syt15, Ercc6, RGD1564958, Tmem161a, and Gatad2a genes are predicted to be damaging to the protein product. Furthermore, a number of genes within the RNO16 differential segment associated with metabolic syndrome components in human studies showed polymorphisms between SHR and BN-Lx (including Lpl, Nrg3, Pbx4, Cilp2, and Stab1. Our novel congenic rat model demonstrates that a limited genomic region on RNO16 in the SHR significantly affects many of the features of metabolic

  20. OXIDATION OF POLYCHLORINATED BIPHENYLS BY LIVER TISSUE SLICES FROM PHENOBARBITAL-PRETREATED MICE IS CONGENER-SPECIFIC AND ATROPSELECTIVE

    OpenAIRE

    Wu, Xianai; Duffel, Michael; Lehmler, Hans-Joachim

    2013-01-01

    Mouse models are powerful tools to study the developmental neurotoxicity of polychlorinated biphenyls (PCBs); however, studies of the oxidation of chiral PCB congeners to potentially neurotoxic hydroxylated metabolites (OH-PCBs) in mice have not been reported. Here we investigate the atropselective oxidation of chiral PCB 91 (2,2',3,4',6-pentachlorobiphenyl), PCB 95 (2,2',3,5',6-pentachlorobiphenyl), PCB 132 (2,2',3,3',4,6'-hexachlorobiphenyl), PCB 136 (2,2',3,3',6,6'-hexachlorobiphenyl) and ...

  1. The use of the space of two straight lines coplanar theorem%空间两条直线共面定理的应用

    Institute of Scientific and Technical Information of China (English)

    周明

    2015-01-01

    空间两条直线有共面和异面两种位置关系,对于两条直线位置关系的判定,通常的方法是判定两条直线所通过已知点构成的矢量与两条直线的方向矢量的混合积是否等于零。若混合积等于零,则两直线共面,若混合积不等于零,则两条直线异面。但对于直线的一般方程而言,此判定方法比较繁琐,不易解决实际问题。利用两条直线共面定理可以判定直纹曲面上直母线间的位置关系,更好地帮助研究直纹曲面的性质。%Two straight lines have coplanar and different planes in space,the usual method of determine the relationship between the location of the two straight lines is whether two straight lines by vector consisting of known points in the di-rection of the vector of mixed product is equal to zero.If mixed product equal to zero,the two lines coplanar,if mixed product is not equal to zero,the two lines in different planes.But for general equation of straight line,this determination method is tedious,not easy to solve practical problems.The coplanar theorem of two straight lines can be used to deter-mine on a ruled surface of the positional relationship between the straight generatrix,to better help the study of properties of the ruled surface.

  2. Fractionation and current time trends of PCB congeners: evolvement of distributions 1950–2010 studied using a global atmosphere-ocean general circulation model

    Directory of Open Access Journals (Sweden)

    G. Lammel

    2012-08-01

    Full Text Available PCBs are ubiquitous environmental pollutants expected to decline in abiotic environmental media in response to decreasing primary emissions since the 1970s. A coupled atmosphere-ocean general circulation model with embedded dynamic sub-models for atmospheric aerosols and the marine biogeochemistry and air-surface exchange processes with soils, vegetation and the cryosphere is used to study the transport and fate of four PCB congeners covering a range of 3–7 chlorine atoms.

    The change of the geographic distribution of the PCB mixture reflects the sources and sinks' evolvement over time. Globally, secondary emissions (re-volatilisation from surfaces are on the long term increasingly gaining importance over primary emissions. Secondary emissions are most important for the congeners with 5–6 chlorine atoms. Correspondingly, the levels of these congeners are predicted to decrease slowest. Changes in congener mixture composition (fractionation are characterized both geographically and temporally. In high latitudes enrichment of the lighter, less persistent congeners and more delayed decreasing levels in response to decreasing emissions are found. The delivery of the contaminants to high latitudes is predicted to be more efficient than previously suggested. The results suggest furthermore that the effectiveness of emission control measures may significantly vary among substances. The trends of decline of organic contaminant levels in the abiotic environmental media do not only vary with latitude (slow in high latitudes, but do also show longitudinal gradients.

  3. Congener-specific levels and patterns of polychlorinated biphenyls in edible fish tissue from the central Red Sea coast of Saudi Arabia

    KAUST Repository

    Batang, Zenon B.

    2016-08-01

    All 209 congeners of polychlorinated biphenyls (PCBs) in edible fish tissue from the central Red Sea coast (Jeddah region) of Saudi Arabia were analyzed by isotope dilution high-resolution gas chromatography–mass spectrometry. The upper-bound total PCB (ΣPCB) levels in nine commonly consumed fish species from three areas were 0.2–82.5 ng/g wet weight (17–8450 ng/g lipid weight), which were at the lower end of reported global range and far below international tolerance limits (500–3000 ng/g ww). Dioxin-like congeners contributed up to 12.8% (mean 6.5%) to ΣPCB in tissue samples, with the total PCB toxic equivalencies (TEQs) at a tolerable range (0.05–2.6 pg TEQ/g ww or 2–238 pg TEQ/g lw) for all species. PCB profiles were dominated by moderately chlorinated homologs, mainly hexachlorobiphenyls, but less chlorinated congeners were also consistently elevated, notably in Siganus rivulatus (Area III) and Mugil cephalus (Area I). It remains to be ascertained if the latter were breakdown products or due to fresh inputs. The top congeners based on dominance by both occurrence and abundance were identified as potential markers of ΣPCB in fish tissue, which can be used for future selective biomonitoring in case of reasonable constraints on full congener approach.

  4. Dietary exposure of juvenile common sole (Solea solea L.) to polybrominated diphenyl ethers (PBDEs): Part 1. Bioaccumulation and elimination kinetics of individual congeners and their debrominated metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Munschy, C., E-mail: cmunschy@ifremer.f [Institut Francais de Recherche pour l' Exploitation de la Mer (IFREMER), Laboratory of Biogeochemistry of Organic Contaminants, Rue de l' Ile d' Yeu, BP 21105, 44311 Nantes Cedex 3 (France); Heas-Moisan, K.; Tixier, C.; Olivier, N. [Institut Francais de Recherche pour l' Exploitation de la Mer (IFREMER), Laboratory of Biogeochemistry of Organic Contaminants, Rue de l' Ile d' Yeu, BP 21105, 44311 Nantes Cedex 3 (France); Gastineau, O.; Le Bayon, N.; Buchet, V. [Institut Francais de Recherche pour l' Exploitation de la Mer (IFREMER), Laboratory of Adaptation, Reproduction and Nutrition of marine fish, BP 70, 29280 Plouzane (France)

    2011-01-15

    The uptake and elimination of six PBDE congeners (BDE-28, -47, -99, -100, -153, -209) were studied in juvenile common sole (Solea solea L.) exposed to spiked contaminated food over a three-month period, then depurated over a five-month period. The results show that all of the studied PBDEs accumulate in fish tissues, including the higher brominated congener BDE-209. Several additional PBDE congeners were identified in the tissues of exposed fish, revealing PBDE transformation, mainly via debromination. The identified congeners originating from PBDE debromination include BDE-49 and BDE-202 and a series of unidentified tetra-, penta-, and hepta- BDEs. Contaminant assimilation efficiencies (AEs) were related to their hydrophobicity (log K{sub ow}) and influenced by PBDE biotransformation. Metabolism via debromination appears to be a major degradation route of PBDEs in juvenile sole in comparison to biotransformation into hydroxylated metabolites. - Juvenile sole exposed to artificially-contaminated food accumulate PBDEs, including the higher brominated congeners, and have a debromination capacity.

  5. Measurement of toxaphene congeners in pooled human serum collected in three U.S. cities using high-resolution mass spectrometry.

    Science.gov (United States)

    Barr, John R; Woolfitt, Adrian R; Maggio, Vincent L; Patterson, Donald G

    2004-05-01

    Because human toxaphene exposure data are largely lacking, we surveyed human serum pools collected from U.S. residents to determine the feasibility of measuring toxaphene in human samples and to determine whether additional analytical requirements were needed for routine measurement of toxaphene. We report a method for quantification of toxaphene congeners in human serum using a mixed-bed gradient solid-phase extraction and analysis using gas chromatography-high-resolution mass spectrometry with electron-impact ionization. In this method, we monitored low-mass fragment ions that were common to all 22 congeners. To verify the specific congeners detected, we further analyzed the extract using negative methane chemical ionization. We used this method to measure two specific congeners, Parlar 26 and 50, at concentrations ranging from about 3 to 30 pg/ml (0.7-7 ng/g lipid) in pooled human serum collected in Atlanta, Chicago, and Cincinnati. We identified several analytical parameters that must be strengthened to routinely measure toxaphene congeners in human samples.

  6. TRANSIENT RESPONSE OF COPLANAR INTERFACIAL CRACKS BETWEEN TWO DISSIMILAR PIEZOELECTRIC STRIPS UNDER ANTI-PLANE MECHANICAL AND IN-PLANE ELECTRICAL IMPACTS

    Institute of Scientific and Technical Information of China (English)

    RayK.L.Su; FengWenjie; LiuJinxi; ZouZhenzhu

    2003-01-01

    The dynamic response of multiple coplanar interface cracks between two dissimilar piezoelectric strips subjected to mechanical and electrical impacts is investigated. Solutions to two kinds of electric boundary conditions on crack surfaces, i.e. electric impermeable and electric permeable, are obtained. Laplace and Fourier transforms and dislocation density functions are employed to reduce the mixed boundary value problem to Cauchy singular integral equations,which can be solved numerically. The effects of electrical load, geometry criterion of piezoelectric strips, relative location of cracks and material properties on the dynamic energy release rate are examined.

  7. Investigation of hydrodynamics and heat transfer at liquid metal downflow in a rectangular duct in a coplanar magnetic field

    Science.gov (United States)

    Poddubnyi, I. I.; Razuvanov, N. G.

    2016-02-01

    Hydrodynamics and heat transfer in a liquid metal downflow in a rectangular duct with an aspect ratio of approximately 3/1 in a coplanar magnetic field (MF) are studied upon inhomogeneous (one-sided) heating of the duct. The flow in the heat-transfer duct of the cooling system of a liquid-metal blanket module of the tokamak-type thermonuclear reactor is modeled. Experiments were carried out at the mercury magnetohydrodynamic (MHD) test facility, which is a part of the MHD-complex of Moscow Power Engineering Institute-Joint Institute for High Temperatures of the Russian Academy of Sciences. A probe technique is used for measurements in the flow. The studies are performed within the following ranges of regime parameters: Reynolds numbers Re = 10000-55000, Hartmann numbers Ha = 0-800, and Grashof numbers Grq = 0-6 × 108. Averaged profiles of velocity, temperature, temperature fluctuations of the flow, and duct wall temperature are presented for two typical flow regimes. Detailed measurements are performed in the duct cross-section distant from the heating beginning in the region of homogeneous MF. MF leads to the turbulent transport suppression, owing to which the temperature on the heated wall increases. A considerable influence of the heat-gravitational counter-convection, the interaction of which with the external MF leads in some regimes to the appearance and development of instabilities in the laminarized flow, is revealed under the downflow conditions. Generation of large-scale secondary vortices with the axis parallel to the MF induction causes temperature fluctuations of the abnormal intensity that considerably exceeds the level of turbulent fluctuations. Such temperature fluctuations easily penetrate into the duct wall and can lead to the fatigue breakdown of thermonuclear reactor cooling paths. Ranges of unallowable regime parameters are determined and the boundary in coordinates Gr-Re is presented, where this effect is revealed or vanishes. The numerical

  8. Plan Quality and Treatment Efficiency for Radiosurgery to Multiple Brain Metastases: Non-Coplanar RapidArc vs Gamma Knife

    Directory of Open Access Journals (Sweden)

    Haisong eLiu

    2016-02-01

    Full Text Available Objectives: This study compares the dosimetry and efficiency of two modern radiosurgery (SRS modalities for multiple brain metastases (Gamma Knife and LINAC-based RapidArc/volumetric modulated arc therapy, with a special focus on the comparison of low dose spread.Methods: Six patients with three or four small brain metastases were used in this study. The size of targets varied from 0.1 ~ 10.5 cc. SRS doses were prescribed according to size of lesions. SRS plans were made using both Gamma Knife® Perfexion and a single-isocenter, multiple non-coplanar RapidArc®. Dosimetric parameters analyzed included RTOG conformity index (CI, gradient index (GI, 12 Gy isodose volume (V12Gy for each target, and the dose spread (Dspread for each plan. Dspread reflects SRS plan’s capability of confining radiation to within the local vicinity of the lesion and to not spread out to the surrounding normal brain tissues. Each plan has a dose (Dspread, such that once dose decreases below Dspread (on total tissue DVH, isodose volume starts increasing dramatically. Dspread is defined as that dose when volume increase first exceeds 20 cc per 0.1 Gy dose decrease. Results: RapidArc SRS has smaller CI (1.19 ±0.14 vs. 1.50 ± 0.16, p<0.001 and larger GI (4.77 ± 1.49 vs. 3.65 ± 0.98, p <0.01. V12Gy results were comparable (2.73 ± 1.38 cc vs. 3.06 ± 2.20 cc, p = 0.58. Moderate to lower dose spread, V6, V4.5, and V3, were also equivalent. Gamma Knife plans achieved better very low dose spread (≤3 Gy and also had slightly smaller Dspread, 1.9 Gy vs 2.5 Gy. Total treatment time for Gamma Knife is estimated between 60~100 min. Gamma Knife treatments are between 3~5 times longer compared to RapidArc treatment techniques.Conclusion: Dosimetric parameters reflecting prescription dose conformality (CI, dose fall off (GI, radiation necrosis indicator (V12Gy, and dose spread (Dspread were compared between Gamma Knife SRS and RapidArc SRS for multi-mets. RapidArc plans have

  9. Coplanar interconnection module

    Science.gov (United States)

    Steward, R. D.; Windsor, H. F.

    1970-01-01

    Module for interconnecting a semiconductor array to external leads or components incorporates a metal external heat sink for cooling the array. Heat sink, extending down from the molded block that supports the array, is immersed in a liquid nitrogen bath which is designed to maintain the desired array temperature.

  10. Seasonal variation of polychlorinated biphenyl congeners in surficial sediment, trapped settling material, and suspended particulate material in Lake Michigan, USA.

    Science.gov (United States)

    Robinson, Sander D; Landrum, Peter F; Van Hoof, Patricia L; Eadie, Brian J

    2008-02-01

    A unique time series of surface sediment, trapped settling material, and suspended particulate material polychlorinated biphenyl (PCB) samples were collected at a 45-m deep site off Grand Haven (MI, USA) over a 14-month period. Both concentrations and congener distributions remained constant for the sediments, although there were seasonal and interannual variability in the other matrices. Trapped settling material and suspended particulate material PCB concentrations were substantially lower (~50%) in 1997 than in the samples from December 1997 through July 1998. The cause could not be determined from the data collected, but there were some very large storms during the winter-spring period of 1998, resulting in major sediment resuspension throughout the southern basin. Observed seasonal variation in PCB concentration and congener distribution on particles likely was due to the changes in particle composition. These include particle size and the source of particles (such as the amount of resuspended sediment in trapped settling material), and the role of diagenesis of the organic matter on particles.

  11. A 25-Year Experience of Gastroenteropancreatic Neuroendocrine Tumors and Somatostatin (Congeners) Analogs: From Symptom Control to Antineoplastic Therapy.

    Science.gov (United States)

    O'Dorisio, Thomas M; Anthony, Lowell B

    2015-01-01

    Radioimmunoassay technology was utilized in the discovery of somatostatin and was quickly brought into therapeutics; however, it took the development of somatostatin congeners to solve its limitations of a short half-life. Therapeutic medical control of hyperhormonal states such as acromegaly, carcinoid syndrome and VIPoma significantly advanced from a nonspecific approach to one that specifically and effectively targeted the underlying pathophysiology. Clinical care was transformed from nonspecific symptom control to one of a significant improvement in not only quality of life, but also quantity of life. These data submitted to US and European regulatory authorities for approval included many investigative sites with no uniform protocol and multiple investigational new drugs, and have not been previously published. This review includes the original data demonstrating the transformational impact this class of agents had on specific disease subsets resulting in regulatory approval 25 years ago. Autoradiography techniques using somatostatin resulted in identifying, localizing and characterizing its receptor subtypes. Translating in vitro data to in vivo resulted in scintigraphic whole body and SPECT scans with (111)In-pentetreotide and was incorporated into standard clinical care 20 years ago. (68)Ga-octreotide congeners using PET scanning offers a major imaging advance. Peptide receptor radiotherapy has evolved over the last 2 decades and utilizes several therapeutic isotopes, including (90)Y and (177)Lu. © 2015 S. Karger AG, Basel.

  12. Investigations on the sorption of a toxaphene model congener, the B7-1450, on marine sediments.

    Science.gov (United States)

    Soubaneh, Youssouf Djibril; Lebeuf, Michel; Gouteux, Bruno; Xie, Huixiang; Nikiforov, Vladimir; Gagné, Jean-Pierre

    2008-04-01

    Sorption is a natural process that takes place in sediments or soils and changes the mobility and availability of hydrophobic organic compounds, such as toxaphene pesticide in the environment. The sorption of the 2-exo,3-endo,5-exo,8,9,10,10-heptachlorobornane (B7-1450), used as a model compound of the toxaphene heptachlorobornane congeners found in sediments, was investigated for the first time through a series of batch sorption experiments. The losses of B7-1450 due to adsorption onto glass walls and to evaporation occurring during analytical treatment steps were corrected. The study showed that these specific losses ranged from 2% to 3.5% for the glass walls adsorption and can be as high as 15% for the evaporation treatment. The sorption coefficients, K(d) and K(oc), of B7-1450 could be overestimated by >30%, particularly for low-concentration samples, if the losses were not corrected. Loss correction equations were established, validated and applied to determine sorption coefficients for the B7-1450 congener. The K(oc) values for B7-1450 determined over a gradient of concentrations ranged from 3.5x10(4) to 6.5x10(4)mlg(-1), revealing a strong affinity of B7-1450 for marine sediments.

  13. Efficacy of Marek's disease vaccines in Mhc heterozygous chickens: Mhc congenic x inbred line F1 matings.

    Science.gov (United States)

    Bacon, L D; Witter, R L

    1995-01-01

    The goal of this study is to demonstrate that Mhc (B) heterozygous chickens differ in efficacy of response to several Marek's disease (MD) vaccines. Four types of B2 heterozygotes, in addition to B2B2 homozygotes, were developed by crossing 15.B congenic males to inbred line 7(1) (B2B2) hens. The five types of F1 chicks were intermingled in isolators and vaccinated with one of four types of MD vaccine before inoculation with the very virulent Md5 strain of MD herpesvirus. The F1 chickens differ in development of protective immunity following MD vaccination from two perspectives. First, chickens of a particular Mhc genotype were protected better by some vaccines than others. Second, individual vaccine preparations protected some Mhc genotypes more effectively. We conclude that some MD vaccines are more appropriate than others for certain B-haplotypes when chickens are heterozygous for the Mhc. The value of using Mhc-congenic x inbred line F1 animals for studies concerning the influence of the Mhc on vaccinal immunity is discussed.

  14. Combined effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and polychlorinated biphenyls congeners in rats

    Energy Technology Data Exchange (ETDEWEB)

    Chu, I. [Environmental Science Bureau, Ottawa (Canada); Valli, V.E. [Coll. of Veterinary Medicine, Urbana (United States)

    2004-09-15

    There has been considerable interest in conducting toxicity studies on mixtures since this approach represents realistic human exposure and would provide a better model to predict the health impacts of environmental chemicals. However, risk assessment of the chemicals is largely based on the toxicity data of individual compounds by assuming simple additive effects of these compounds. This practice has been accepted by regulatory agencies provided that the concentrations of chemicals are extremely low, and there are no interactions. The existence of interactions among the chemicals co-administered to test animals may under or over estimate the effects of a mixture if the simple additive rule is applied. Previously, we demonstrated an antagonistic effect in rats when tetrachlorodibenzo-p-dioxin (TCDD) was co-administered with polychlorinated biphenyls congeners (PCBs). The hepatic microsomal EROD, MROD and UDPGT activities of TCDD were decreased when co-administered with PCB congeners. To further explore the combined effects of these pollutants, we examined and report results on tissue residue levels of TCDD and histopathological changes in target organs of rats exposed to TCDD, PCBs and mixtures of both.

  15. Congener-specific carbon isotopic analysis of technical PCB and PCN mixtures using two-dimensional gas chromatography-isotope ratio mass spectrometry.

    Science.gov (United States)

    Horii, Yuichi; Kannan, Kurunthachalam; Petrick, Gert; Gamo, Toshitaka; Falandysz, Jerzy; Yamashita, Nobuyoshi

    2005-06-01

    Analysis of stable carbon isotope fractionation is a useful method to study the sources and fate of anthropogenic organic contaminants such as polychlorinated biphenyls (PCBs) in the environment. To evaluate the utility of carbon isotopes, determination of isotopic ratios of 13C/12C in source materials, for example, technical PCB preparations, is needed. In this study, we determined delta13C values of 31 chlorobiphenyl (CB) congeners in 18 technical PCB preparations and 15 chloronaphthalene (CN) congeners in 6 polychlorinated naphthalene preparations using two-dimensional gas chromatography-combustion furnace-isotope ratio mass spectrometry (2DGC-C-IRMS). Development of 2DGC-IRMS enabled improved resolution and sensitivity of compound-specific carbon isotope analysis (CSIA) of CB or CN congeners. Delta13C values of PCB congeners ranged from -34.4 (Delors) to -22.0/1000 (Sovol). Analogous PCB preparations with similar chlorine content, but different geographical origin, had different delta13C values. PCB preparations from Eastern European countries--Delors, Sovol, Trichlorodiphenyl, and Chlorofen--had distinct delta13C values. PCB mixtures showed increased 13C depletion with increasing chlorine content. Delta13C values for individual CB congeners varied depending on the degree of chlorination in technical mixtures. Delta13C values of CN congeners in Halowaxes ranged from -26.3 to -21.7/1000 and these values are within the ranges observed for PCBs. This study establishes the range of delta13C values in technical PCB and PCN preparations, which may prove to be useful in the determination of sources of these compounds in the environment. This is the first study to employ 2DGC-IRMS analysis of delta13C values in technical PCB and PCN preparations.

  16. A Comparative Study between Via-Hole and Via-Free Grounded Coplanar Waveguide to Microstrip Transitions on Thin Polymer Substrate

    Directory of Open Access Journals (Sweden)

    Mohammed El Gibari

    2015-01-01

    Full Text Available A comparative study between via-holed and via-free back-to-back GCPW-MS-GCPW (Grounded Coplanar Waveguide-Microstrip lines transitions is reported in this paper. According to simulation results, both via-holed and via-free transitions on commercial benzocyclobutene polymer 20 µm film show a bandwidth over 57 GHz. Bandwidth of optimized via-holed transitions increases with the via-hole diameter, up to 75 GHz with 300 μm via-hole diameter. The via-hole free transition achieves experimentally an ultrabroadband from 2 GHz to 78 GHz with an insertion loss of only 0.5 dB thanks to the copper metallization thickness of 2 μm. In addition, these measurement results are in perfect agreement with the simulation results. These via-free and via-holes transitions are very useful and requested in component packaging, on-wafer measurements of microstrip based microwave integrated circuits, and also the interconnections in hybrid circuits including both microstrip and coplanar structures.

  17. Single-conductor co-planar quasi-symmetry unequal power divider based on spoof surface plasmon polaritons of bow-tie cells

    Directory of Open Access Journals (Sweden)

    Yongle Wu

    2016-10-01

    Full Text Available In this paper, the spoof surface plasmon polaritons (SSPPs transmission line (TL of periodical grooved bow-tie cells is proposed. The complex propagation constant and characteristic impedance of the SSPPs TLs and microstrip lines (MLs are extracted using the analytical method of generalized lossy TL theory. The properties of the SSPPs TLs with different substrates and the same geometrical configuration are experimented. Then, for comparison, two ML counterparts are also experimented, which shows that the SSPPs TL is less sensitive to the thickness, dielectric constant and loss tangent of the chosen substrate below the cutoff frequency, compared with the ML ones. The single-conductor co-planar quasi-symmetry unequal power divider based on this SSPPs TL is presented in microwave frequencies. For experimental validation, the 0-dB, 2-dB, and 5-dB power dividers are designed, fabricated, and measured. Both simulated and measured results verify that the unequal power divider is a flexible option, which offers massive advantages including single-conductor co-planar quasi-symmetry structures, wide-band operation, and convenient implementations of different power-dividing ratios. Hence, it can be expected that the proposed unequal power dividers will inspire further researches on SSPPs for future design of novel planar passive and active microwave components, circuits and systems.

  18. Single-conductor co-planar quasi-symmetry unequal power divider based on spoof surface plasmon polaritons of bow-tie cells

    Science.gov (United States)

    Wu, Yongle; Li, Mingxing; Yan, Guangyou; Deng, Li; Liu, Yuanan; Ghassemlooy, Zabih

    2016-10-01

    In this paper, the spoof surface plasmon polaritons (SSPPs) transmission line (TL) of periodical grooved bow-tie cells is proposed. The complex propagation constant and characteristic impedance of the SSPPs TLs and microstrip lines (MLs) are extracted using the analytical method of generalized lossy TL theory. The properties of the SSPPs TLs with different substrates and the same geometrical configuration are experimented. Then, for comparison, two ML counterparts are also experimented, which shows that the SSPPs TL is less sensitive to the thickness, dielectric constant and loss tangent of the chosen substrate below the cutoff frequency, compared with the ML ones. The single-conductor co-planar quasi-symmetry unequal power divider based on this SSPPs TL is presented in microwave frequencies. For experimental validation, the 0-dB, 2-dB, and 5-dB power dividers are designed, fabricated, and measured. Both simulated and measured results verify that the unequal power divider is a flexible option, which offers massive advantages including single-conductor co-planar quasi-symmetry structures, wide-band operation, and convenient implementations of different power-dividing ratios. Hence, it can be expected that the proposed unequal power dividers will inspire further researches on SSPPs for future design of novel planar passive and active microwave components, circuits and systems.

  19. Cucurbita spp. and Cucumis sativus enhance the dissipation of polychlorinated biphenyl congeners by stimulating soil microbial community development.

    Science.gov (United States)

    Qin, Hua; Brookes, Philip C; Xu, Jianming

    2014-01-01

    A number of Cucurbita species have the potential to extract polychlorinated biphenyls (PCBs) from soil, but their impact on the soil microbial communities responsible for PCB degradation remains unclear. A greenhouse experiment was conducted to investigate the effect of three Cucurbita and one Cucumis species on PCB dissipation and soil microbial community structure. Compared to the unplanted control, enhanced losses of PCBs (19.5%-42.7%) were observed in all planted soils. Cucurbita pepo and Cucurbita moschata treatments were more efficient in PCB dissipation, and have similar patterns of soil phospholipid fatty acids (PLFAs) and PCB congener profiles. Cucurbita treatments tend to have higher soil microbial biomass than Cucumis. Gram-negative (G(-)) bacteria were significantly correlated with PCB degradation rates (R(2) = 0.719, p Cucurbita related soil microorganisms could play an important role in remediation of PCB contaminated soils.

  20. Different Responses of an Invasive Clonal Plant Wedelia trilobata and its Native Congener to Gibberellin: Implications for Biological Invasion.

    Science.gov (United States)

    Dai, Zhi-Cong; Fu, Wei; Qi, Shan-Shan; Zhai, De-Li; Chen, Si-Chong; Wan, Ling-Yun; Huang, Ping; Du, Dao-Lin

    2016-02-01

    The invasive clonal plant Wedelia trilobata contains higher levels of ent-kaurane diterpenes, which are precursors of gibberellins (GAs), and higher rates of clonal growth than its native congener W. chinensis in invaded habitats. We hypothesized that the higher levels of endogenous GAs facilitate greater ramet growth in W. trilobata compared with W. chinensis. We quantified endogenous levels of GA1+3 in the two species and compared their growth responses to the changes of endogenous and exogenous GA3 by using short-term and long-term hydroponics experiments. After a period of homogeneous cultivation, levels of endogenous GA1+3 were higher in W. trilobata than in W. chinensis. The reduction of endogenous GAs repressed the emergence of adventitious roots and the growth of W. trilobata in the initial cultivation stage, and inhibited its shoot elongation and biomass. Levels of endogenous GA1+3 were positively correlated with the length of shoots and adventitious roots of W. trilobata. Adventitious roots of W. trilobata also emerged earlier and grew faster when treated with exogenous GA3. In contrast, exogenous GA3 treatment inhibited the length of adventitious roots in W. chinensis, and levels of endogenous GA1+3 did not correlate with shoot or adventitious root length. Our study suggests that GAs accelerate the rapid clonal growth of W. trilobata, more than that of its native congener W. chinensis, illustrating the relationship between plant hormones and the clonal growth of invasive plants. These findings are important for understanding the mechanisms associated with the invasiveness of clonal plants and their potential management.

  1. Organochlorine pesticides and polychlorinated biphenyl congeners in wild terrestrial mammals from Croatia: Interspecies comparison of residue levels and compositions.

    Science.gov (United States)

    Herceg Romanić, Snježana; Klinčić, Darija; Kljaković-Gašpić, Zorana; Kusak, Josip; Reljić, Slaven; Huber, Đuro

    2015-10-01

    In this pilot study, we investigated levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in the adipose tissues of two free-ranging terrestrial carnivores from Croatia sampled in 2010 and 2011: the brown bear (Ursus arctos; N=32) and the grey wolf (Canis lupus; N=29). Concentrations of ∑OCPs and ΣPCBs ranged from 0.45 to 4.09 ng g(-1) lipid mass (lm) and from 0.93 to 8.52 ng g(-1) lm in brown bear, and from 1.18 to 5.67 ng g(-1) lm and 2.68 to 48.9 ng g(-1) lm in grey wolf adipose tissues, respectively. PCBs were dominant accounting for over 72% of total analyzed persistent organic pollutants (POPs). The sum of six indicator non-dioxin-like PCBs (Σ6IndNDL PCBs) made up 60-93% and 58-85% of the total congener concentrations in brown bears and wolves, respectively. Although the levels of the measured parameters were significantly higher in grey wolves than in bears, the contaminant profiles of the two species were similar, with γ-HCH, HCB, β-HCH and DDE as major OCP contaminants, and PCB-153>PCB-180≈PCB-170>PCB-138 as the dominant congeners. The sum of hexachlorocyclohexanes (ΣHCHs) and 8 toxicologically relevant dioxin-like PCBs (Σ8ToxDL PCBs) was higher in the males than in the females of the brown bear. Concentrations of ΣDDTs, HCB, ΣOCP, ΣPCBs, Σ6IndNDL PCBs, and toxicologically relevant non-dioxin-like PCBs (ΣToxNDL PCBs) were significantly positively correlated with lipid content in the grey wolf. Concentrations of OCPs and PCBs in brown bears and wolves from Croatia were low and normal for large terrestrial mammals.

  2. Congener-specific concentrations and carbon stable isotope ratios (delta13C) of two technical toxaphene products (Toxaphene and Melipax).

    Science.gov (United States)

    Vetter, Walter; Gleixner, Gerd; Armbruster, Wolfgang; Ruppe, Steffen; Stern, Gary A; Braekevelt, Eric

    2005-01-01

    In this study we compared the contribution of individual congeners and the ratios of stable carbon isotopes of two technical toxaphene products. The former US-American product Toxaphene was from 1978 and the East-German product Melipax from 1979. Both technical products showed the known complexity in GC/ECD measurements. Contributions of 24 peaks to each of the technical products were determined by gas chromatography in combination high resolution electron capture negative ion mass spectrometry (GC/ECNI-HRMS). The percentages of the compounds studied in the technical mixtures ranged from approximately 0.05% to approximately 2.5% but showed some individual differences. 2,2,5,5,8,9,9,10,10-nonachlorobornane (B9-1025 or P-62) was identified as a major congener in both mixtures. 2-Endo,3-exo,5-endo,6-exo,8,8,10,10-octachlorobornane (B8-1413 or P26) and 2-endo,3-exo,5-endo,6-exo,8,8,9,10,10-nonachlorobornane (B9-1679 or P-50) were found at similar concentration in both technical products. Identical amounts of Melipax or Toxaphene were combusted to CO2 in an element analyzer and their delta13C values were determined relative to the international standard Vienna PeeDee belemnite (VPDB). The mean delta13C values of both products varied by 2.8% (determined at two different locations) which is roughly one order of magnitude more than the precision obtained in repetitive analyses of the individual products. Thus, both investigated products could be unequivocally distinguished by stable isotope ratio mass spectrometry (IRMS). IRMS analyses may thus be a suitable tool for tracing back toxaphene residues in environmental and food samples to the one or both of the products.

  3. (+)Lysergic acid diethylamide, but not its nonhallucinogenic congeners, is a potent serotonin 5HT1C receptor agonist

    Energy Technology Data Exchange (ETDEWEB)

    Burris, K.D.; Breeding, M.; Sanders-Bush, E. (Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN (United States))

    1991-09-01

    Activation of central serotonin 5HT2 receptors is believed to be the primary mechanism whereby lysergic acid diethylamide (LSD) and other hallucinogens induce psychoactive effects. This hypothesis is based on extensive radioligand binding and electrophysiological and behavioral studies in laboratory animals. However, the pharmacological profiles of 5HT2 and 5HT1C receptors are similar, making it difficult to distinguish between effects due to activation of one or the other receptor. For this reason, it was of interest to investigate the interaction of LSD with 5HT1C receptors. Agonist-stimulated phosphoinositide hydrolysis in rat choroid plexus was used as a direct measure of 5HT1C receptor activation. (+)LSD potently stimulated phosphoinositide hydrolysis in intact choroid plexus and in cultures of choroid plexus epithelial cells, with EC50 values of 9 and 26 nM, respectively. The effect of (+)LSD in both systems was blocked by 5HT receptor antagonists with an order of activity consistent with interaction at 5HT1C receptors. Neither (+)-2-bromo-LSD nor lisuride, two nonhallucinogenic congeners of LSD, were able to stimulate 5HT1C receptors in cultured cells or intact choroid plexus. In contrast, lisuride, like (+)LSD, is a partial agonist at 5HT2 receptors in cerebral cortex slices and in NIH 3T3 cells transfected with 5HT2 receptor cDNA. The present finding that (+)LSD, but not its nonhallucinogenic congeners, is a 5HT1C receptor agonist suggests a possible role for these receptors in mediating the psychoactive effects of LSD.

  4. Dopamine-dependent behavior in adult rats after perinatal exposure to purity-controlled polychlorinated biphenyl congeners (PCB52 and PCB180).

    Science.gov (United States)

    Lilienthal, Hellmuth; Heikkinen, Päivi; Andersson, Patrik L; van der Ven, Leo T M; Viluksela, Matti

    2014-01-03

    Since knowledge about toxic effects of non-dioxinlike (NDL) PCBs is fragmentary, regulatory panels have concluded that risk assessment of these congeners is hampered or impossible. As the dopaminergic system is one of the main targets in PCB-related neurotoxic effects after developmental exposure, we selected catalepsy induced by the dopamine receptor blocker haloperidol to characterize effects of the NDL congeners PCB52 and PCB180 in adult offspring from exposed rat dams. Rat dams were treated with PCB congeners by gavage using six dose levels (total doses: PCB52 - 0, 30, 100, 300, 1000 or 3000 mg/kg body wt.; PCB180 - 0, 10, 30, 100, 300, or 1000 mg/kg body wt.) to allow benchmark dose analysis of the results. Testing of adult offspring (starting at 180 days of age) for catalepsy induced by injection with haloperidol revealed slightly prolonged latencies to movement onset in female offspring exposed to PCB52. Exposure to PCB180 resulted in more pronounced effects, with generally reduced latencies in male offspring. These results indicate reduced dopaminergic activity after PCB52 exposure, whereas the outcome for PCB180 may be related to increased extracellular dopamine as reported in the literature.Benchmark dose analyses revealed that both PCB congeners exerted effects mainly at moderate exposure levels. Together, these results underline the importance of effects on the dopaminergic system as indicated by studies in human females after occupational PCB exposure.

  5. Coexposure of dioxin-like polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins and dibenzofurans in free-range hens and implications derived from congener profile analysis.

    Science.gov (United States)

    Lin, Chingju; Hsu, Jing-Fang; Liao, Pao-Chi

    2012-02-29

    The consumption of free-range eggs is becoming more popular worldwide. We analyzed the levels of 12 dioxin-like polychlorinated biphenyls (dl-PCBs) and their congener profiles from 6 free-range and 12 caged egg samples. The mean levels of dl-PCBs in the free-range samples were 5.4 times higher than those in caged eggs. All egg samples exhibited at least two characteristic dl-PCB congener patterns, which reflected distinctive contamination sources. Additionally, for the first time, we demonstrated that the dl-PCB levels in the free-range eggs were highly correlated with elevated levels of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) (r = 0.986; p < 0.001), indicating a coexposure scenario in free-range hens. Cluster analysis of congener patterns implied that this coexposure scenario could be attributed to distinct dl-PCB and PCDD/F sources. This congener profile information provides insights from a different perspective for further identifying potential dl-PCB and PCDD/F sources in the polluted free-range eggs.

  6. Tissue Distribution of Polychlorinated Biphenyls and Organochlorine Pesticides and Potential Toxicity to Alaskan Northern Fur Seals Assessed Using PCBs Congener Specific Mode of Action Schemes

    Science.gov (United States)

    The concentrations of 145 polychlorinated biphenyl (PCB) congeners were measured using gas chromatography-ion trap mass spectrometry in 8 different tissues (blubber, brain, heart, kidney, liver, lung, muscle, and reproductive tissues) of 10 Alaskan northern fur seals. The mean concentrations of bot...

  7. CD8+ T cells are crucial for the ability of congenic normal mice to reject highly immunogenic sarcomas induced in nude mice with 3-methylcholanthrene

    DEFF Research Database (Denmark)

    Boesen, M; Svane, I M; Engel, A M;

    2000-01-01

    An attempt was made to identify the selection pressures put upon a growing tumour by CD8+ T cells. To this end tumours induced with 3-methylcholanthrene in T cell-deficient nude mice and in congenic T cell-competent nu/+ mice were transplanted to nu/+ recipients. The rejection rate of the sarcomas...

  8. USING BASE-SPECIFIC SALMONELLA TESTER STRAINS TO CHARACTERIZE THE TYPES OF MUTATION INDUCED BY BENZIDINE AND BENZIDINE CONGENERS AFTER REDUCTIVE METABOLISM

    Science.gov (United States)

    Abstract Benzidine, 4-aminobiphenyl, 3,3'-dichlorobenzidine HCl, 3,3'-dimethylbenzidine, 3,3'- dimethoxybenzidine and benzidine congener-based dye trypan blue were mutagenic in Salmonella typhimurium TAl 00 only with metabolic activation. It was found that a hamster liver 89 ...

  9. Phenomenological and Spectroscopic Analysis on the Effects of Sediment Ageing and Organic Carbon on the Fate of a PCB Congener Spiked to Sediment

    Science.gov (United States)

    This study assesses the full cycle transport and fate of a polychlorinated biphenyl (PCB) congener spiked to sediment to empirically and spectroscopically investigate the effects of sediment ageing and organic carbon on the adsorption, desorption, and reaction of the PCB. Caesar ...

  10. SU-F-BRB-12: A Novel Haar Wavelet Based Approach to Deliver Non-Coplanar Intensity Modulated Radiotherapy Using Sparse Orthogonal Collimators

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, D; Ruan, D; Low, D; Sheng, K [Deparment of Radiation Oncology, University of California Los Angeles, Los Angeles, CA (United States); O’Connor, D [Deparment of Mathematics, University of California Los Angeles, Los Angeles, CA (United States); Boucher, S [RadiaBeam Technologies, Santa Monica, CA (United States)

    2015-06-15

    Purpose: Existing efforts to replace complex multileaf collimator (MLC) by simple jaws for intensity modulated radiation therapy (IMRT) resulted in unacceptable compromise in plan quality and delivery efficiency. We introduce a novel fluence map segmentation method based on compressed sensing for plan delivery using a simplified sparse orthogonal collimator (SOC) on the 4π non-coplanar radiotherapy platform. Methods: 4π plans with varying prescription doses were first created by automatically selecting and optimizing 20 non-coplanar beams for 2 GBM, 2 head & neck, and 2 lung patients. To create deliverable 4π plans using SOC, which are two pairs of orthogonal collimators with 1 to 4 leaves in each collimator bank, a Haar Fluence Optimization (HFO) method was used to regulate the number of Haar wavelet coefficients while maximizing the dose fidelity to the ideal prescription. The plans were directly stratified utilizing the optimized Haar wavelet rectangular basis. A matching number of deliverable segments were stratified for the MLC-based plans. Results: Compared to the MLC-based 4π plans, the SOC-based 4π plans increased the average PTV dose homogeneity from 0.811 to 0.913. PTV D98 and D99 were improved by 3.53% and 5.60% of the corresponding prescription doses. The average mean and maximal OAR doses slightly increased by 0.57% and 2.57% of the prescription doses. The average number of segments ranged between 5 and 30 per beam. The collimator travel time to create the segments decreased with increasing leaf numbers in the SOC. The two and four leaf designs were 1.71 and 1.93 times more efficient, on average, than the single leaf design. Conclusion: The innovative dose domain optimization based on compressed sensing enables uncompromised 4π non-coplanar IMRT dose delivery using simple rectangular segments that are deliverable using a sparse orthogonal collimator, which only requires 8 to 16 leaves yet is unlimited in modulation resolution. This work is

  11. Effects of oral exposure to naturally-occurring and synthetic deoxynivalenol congeners on proinflammatory cytokine and chemokine mRNA expression in the mouse

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wenda [College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095 (China); Dept. of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824 (United States); He, Kaiyu [Center for Integrative Toxicology, Michigan State University, East Lansing, MI 48824 (United States); Dept. of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824 (United States); Zhou, Hui-Ren [Dept. of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824 (United States); Berthiller, Franz [Christian Doppler Laboratory for Mycotoxin Metabolism and Center for Analytical Chemistry, University of Natural Resources and Life Sciences, Tulln (Austria); Adam, Gerhard [Dept. of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Vienna (Austria); Sugita-Konishi, Yoshiko [Food and Life Sciences, Azabu University, 1-17-71 Fuchinobe Chuo-ku, Sagamihara, Kanagawa Pref., 252-5201 (Japan); Watanabe, Maiko [Division of Microbiology, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya, Tokyo 158-8501 (Japan); Krantis, Anthony [Dept. of Cellular and Molecular Medicine, University of Ottawa (Canada); Durst, Tony [Dept. of Chemistry, University of Ottawa (Canada); Zhang, Haibin [College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095 (China); Pestka, James J., E-mail: pestka@msu.edu [Dept. of Food Science and Human Nutrition, Michigan State University, East Lansing, MI 48824 (United States); Center for Integrative Toxicology, Michigan State University, East Lansing, MI 48824 (United States); Dept. of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824 (United States)

    2014-07-15

    The foodborne mycotoxin deoxynivalenol (DON) induces a ribotoxic stress response in mononuclear phagocytes that mediate aberrant multi-organ upregulation of TNF-α, interleukins and chemokines in experimental animals. While other DON congeners also exist as food contaminants or pharmacologically-active derivatives, it is not known how these compounds affect expression of these cytokine genes in vivo. To address this gap, we compared in mice the acute effects of oral DON exposure to that of seven relevant congeners on splenic expression of representative cytokine mRNAs after 2 and 6 h. Congeners included the 8-ketotrichothecenes 3-acetyldeoxynivalenol (3-ADON), 15-acetyldeoxynivalenol (15-ADON), fusarenon X (FX), nivalenol (NIV), the plant metabolite DON-3-glucoside (D3G) and two synthetic DON derivatives with novel satiety-inducing properties (EN139528 and EN139544). DON markedly induced transient upregulation of TNF-α IL-1β, IL-6, CXCL-2, CCL-2 and CCL-7 mRNA expressions. The two ADONs also evoked mRNA expression of these genes but to a relatively lesser extent. FX induced more persistent responses than the other DON congeners and, compared to DON, was: 1) more potent in inducing IL-1β mRNA, 2) approximately equipotent in the induction of TNF-α and CCL-2 mRNAs, and 3) less potent at upregulating IL-6, CXCL-2, and CCL-2 mRNAs. EN139528's effects were similar to NIV, the least potent 8-ketotrichothecene, while D3G and EN139544 were largely incapable of eliciting cytokine or chemokine mRNA responses. Taken together, the results presented herein provide important new insights into the potential of naturally-occurring and synthetic DON congeners to elicit aberrant mRNA upregulation of cytokines associated with acute and chronic trichothecene toxicity. - Highlights: • We compared effects of DON congeners on biomarker proinflammatory genes in mice. • Oral DON induced splenic IL-1β, IL-6, TNF-α,CXCL-2, CCL-2 and CCL-7 mRNAs. • 8-Ketotrichothecene ranking

  12. Polybrominated diphenyl ether congeners in the young-of-the-year bluefish, Pomatomus saltatrix, from several nursery habitats along the US Atlantic coastline.

    Science.gov (United States)

    Deshpande, Ashok D; Dockum, Bruce W

    2013-12-15

    Spatial trends of polybrominated diphenyl ether (PBDE) congeners were examined by using high resolution gas chromatography-low resolution electron impact mass spectrometry (GC-EIMS) in 414 samples of young-of-the-year (YOY) bluefish (Pomatomus saltatrix) collected from a total of 29 nursery habitats along the US Atlantic coastline from Massachusetts to Florida. Of the 26 target PBDE congeners, BDE-47 (4 Br), BDE-100 (5 Br), BDE-49 (4 Br), BDE-99 (5 Br), and BDE-154 (6 Br) were the five most frequently detected congeners in the order of decreasing importance. The sum of the concentrations of five major PBDE congeners, referred to as ΣPBDEs, varied between estuaries and also among samples from a given estuary. ΣPBDEs were lowest in YOY bluefish from Vineyard Sound, Nantucket Sound, Great Bay, Delaware Bay, Lynnhaven Bay, Cape Lookout, and Crescent Beach, with maximum ΣPBDE concentrations below 10 ng/g wet weight. ΣPBDEs in three bluefish samples from Stamford Harbor were detected at relatively high to unusually high concentrations of 69.1, 205, and 561 ng/g wet weight. ΣPBDE values for other Stamford Harbor bluefish were generally low. Highest PBDE concentrations were detected in the vicinity of industrial and urban locations within the New York-New Jersey metropolitan complex. Among them, bluefish from Newark Bay were generally the most contaminated with an average ΣPBDE value of 56.6 ± 30.8 ng/g wet weight. ΣPBDEs in bluefish from Newark Bay were numerically greater than ΣPBDEs in bluefish from all locations, however these differences were not statistically significant. Modest to good correlations between ΣPBDEs and lipids were observed for YOY bluefish from Buzzards Bay, Upper New Bedford Harbor, Lower New Bedford Harbor, Outer New Bedford Harbor, Providence Harbor, Housatonic River, Norwalk Harbor, Little Neck Bay, Newark Bay, Sandy Hook Bay, Great Bay, Delaware Bay, Patuxent River and Crescent Beach. Poor correlations between ΣPBDE and lipids were

  13. Survey of serum concentrations of dioxins, furans, and coplanar polychlorinated biphenyls in a small non-random sample of U.S. residents

    Energy Technology Data Exchange (ETDEWEB)

    Grassman, J. [Brooklyn Coll. CUNY, Health and Nutrition Sciences, Brooklyn, New York, NY (United States); Patterson, D.G. Jr.; Needham, L.L. [National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA (United States); Spencer, D.L.; Masten, S.A. [Environmental Toxicology Program, National Inst. of Environmental Health Sciences, Research Triangle Park, NC (United States)

    2004-09-15

    This cross sectional assessment of serum dioxin concentrations was conducted as part of a larger study to examine the relationship between dioxin exposure and gene expression in peripheral blood mononuclear cells. Recent reports indicate that environmental levels of dioxins have declined since the mid-1980's. Except for the recent National Health and Nutrition Examination Survey (NHANES), there has been little systematic surveillance of serum dioxins levels in the US general population. Here, we report the serum concentrations of 22 congeners of dioxins and dioxin-like compounds and their relationship with age, sex, smoking, and meat consumption.

  14. Journal Article: the National Dioxin Air Monitoring Network (Ndamn): Measurements of CDDs, CDFs, and Coplanar PCBs at 18 Rural, 8 National Parks, and 2 Suburban Areas of the U.S.: Results for the Year 2000.

    Science.gov (United States)

    In June, 1998, the U.S. EPA established the National Dioxin Air Monitoring Network (NDAMN). The primary goal of NDAMN is determine the temporal and geographical variability of atmospheric CDDs, CDFs, and coplanar PCBs at rural and nonimpacted locations throughout the United Stat...

  15. Journal Article: the National Dioxin Air Monitoring Network (Ndamn): Measurements of CDDs, CDFs and Coplanar PCBs at 15 Rural and 6 National Park Areas of the U.S.: June 1998-December 1999.

    Science.gov (United States)

    The U.S. EPA has established a National Dioxin Air Monitoring Network (NDAMN) to determine the temporal and geographical variability of atmospheric CDDs, CDFs and coplanar PCBs at rural and nonimpacted locations throughout the United States. Currently operating at 32 sampling st...

  16. Coplanar-waveguide-based silicon Mach-Zehnder modulator using a meandering optical waveguide and alternating-side PN junction loading.

    Science.gov (United States)

    Dong, Po; Sinsky, Jeffrey H; Gui, Chengcheng

    2016-09-15

    We demonstrate a silicon Mach-Zehnder modulator with a coplanar waveguide transmission-line electrode structure using a meandering optical waveguide and alternating-side PN junction loading of the electrodes, which helps suppress the signal distortion caused by the parasitic slot-line mode and improves the electro-optic (EO) bandwidth. The silicon MZM exhibits a π-phase-shift voltage (Vπ) of 4.5 V with an EO 3 dB bandwidth of ∼20  GHz for a 5 mm long phase shifter. This achieved Vπ is among the lowest for silicon-only modulators with a bandwidth of more than 20 GHz.

  17. Dielectric dispersion of BaxSr1-xTiO3 thin film with parallel-plate and coplanar interdigital electrodes

    Science.gov (United States)

    Zhang, Xiao-Yu; Song, Qing; Xu, Feng; Sheng, Su; Wang, Peng; Ong, C. K.

    2009-03-01

    Ferroelectric BaxSr1-xTiO3 (BST) thin films with x = 0.25 and 0.5 were grown by pulsed laser deposition on single crystal LaAlO3 and Pt/Ti/SiO2/Si substrates, respectively. Capacitors were then fabricated from the BST thin films based on coplanar interdigital electrodes (CIEs) and parallel-plate electrodes (PPEs). The dielectric properties of the BST film with CIE and PPE were investigated and compared over a wide frequency range from 100 Hz to 10 GHz. The dielectric dispersion in PPE configuration, caused by the interfacial polarization in film/electrode interfaces, exhibited a strong dependence on frequency. However, the permittivity ɛCIE in CIE configuration shows a gentle variation with the frequency indicating interfacial polarization substantially suppressed. The influence upon the dielectric properties of the columnar BST grains due to the use of different forms of electrodes was discussed.

  18. Synchrotron radiation studies of spectral response features caused by Te inclusions in a large volume coplanar grid CdZnTe detector

    CERN Document Server

    Hansson, Conny C T; Quarati, Francesco; Kozorezov, Alexander; Gostilo, Vladimir; Lumb, David

    2011-01-01

    We report preliminary results from a synchrotron radiation study of Te inclusions in a large volume single crystal CdZnTe (CZT) coplanar-grid detector. The experiment was carried out by probing individual inclusions with highly collimated monochromatic X-and gamma-ray beams. It was found that for shallow X-ray interaction depths, the effect of an inclusion on measured energy loss spectra is to introduce a ~10% shift in the peak centroid energy towards lower channel numbers. The total efficiency is however not affected, showing that the net result of inclusions is a reduction in the Charge Collection Efficiency (CCE). For deeper interaction depths, the energy-loss spectra shows the emergence of two distinct peaks, both downshifted in channel number. We note that the observed spectral behavior shows strong similarities with that reported in semiconductors which exhibit polarization effects, suggesting that the underlying mechanism is common.

  19. Analysis of Schottky Contact Formation in Coplanar Au/ZnO/Al Nanogap Radio Frequency Diodes Processed from Solution at Low Temperature.

    Science.gov (United States)

    Semple, James; Rossbauer, Stephan; Anthopoulos, Thomas D

    2016-09-01

    Much work has been carried out in recent years in fabricating and studying the Schottky contact formed between various metals and the n-type wide bandgap semiconductor zinc oxide (ZnO). In spite of significant progress, reliable formation of such technologically interesting contacts remains a challenge. Here, we report on solution-processed ZnO Schottky diodes based on a coplanar Al/ZnO/Au nanogap architecture and study the nature of the rectifying contact formed at the ZnO/Au interface. Resultant diodes exhibit excellent operating characteristics, including low-operating voltages (±2.5 V) and exceptionally high current rectification ratios of >10(6) that can be independently tuned via scaling of the nanogap's width. The barrier height for electron injection responsible for the rectifying behavior is studied using current-voltage-temperature and capacitance-voltage measurements (C-V) yielding values in the range of 0.54-0.89 eV. C-V measurements also show that electron traps present at the Au/ZnO interface appear to become less significant at higher frequencies, hence making the diodes particularly attractive for high-frequency applications. Finally, an alternative method for calculating the Richardson constant is presented yielding a value of 38.9 A cm(-2) K(-2), which is close to the theoretically predicted value of 32 A cm(-2) K(-2). The implications of the obtained results for the use of these coplanar Schottky diodes in radio frequency applications is discussed.

  20. Possible Outcomes of Coplanar High-eccentricity Migration: Hot Jupiters, Close-in Super-Earths, and Counter-orbiting Planets

    Science.gov (United States)

    Xue, Yuxin; Masuda, Kento; Suto, Yasushi

    2017-02-01

    We investigate the formation of close-in planets in near-coplanar eccentric hierarchical triple systems via the secular interaction between an inner planet and an outer perturber (Coplanar High-eccentricity Migration; CHEM). We generalize the previous work on the analytical condition for successful CHEM for point masses interacting only through gravity by taking into account the finite mass effect of the inner planet. We find that efficient CHEM requires that the systems should have m1 ≪ m0 and m1 ≪ m2. In addition to the gravity for point masses, we examine the importance of the short-range forces, and provide an analytical estimate of the migration timescale. We perform a series of numerical simulations in CHEM for systems consisting of a Sun-like central star, giant gas inner planet, and planetary outer perturber, including the short-range forces and stellar and planetary dissipative tides. We find that most of such systems end up with a tidal disruption; a small fraction of the systems produce prograde hot Jupiters (HJs), but no retrograde HJ. In addition, we extend CHEM to super-Earth mass range, and show that the formation of close-in super-Earths in prograde orbits is also possible. Finally, we carry out CHEM simulation for the observed hierarchical triple and counter-orbiting HJ systems. We find that CHEM can explain a part of the former systems, but it is generally very difficult to reproduce counter-orbiting HJ systems.

  1. Long-range atmospheric transport of three toxaphene congeners across Europe. Modeling by chained single-box FATEMOD program.

    Science.gov (United States)

    Paasivirta, Jaakko; Sinkkonen, Seija; Nikiforov, Vladimir; Kryuchkov, Fedor; Kolehmainen, Erkki; Laihia, Katri; Valkonen, Arto; Lahtinen, Manu

    2009-03-01

    Since toxaphene (polychlorocamphene, polychloropinene, or strobane) mixtures were applied for massive insecticide use in the 1960s to replace the use of DDT, some of their congeners have been found at high latitudes far away from the usage areas. Especially polychlorinated bornanes have demonstrated dominating congeners transported by air up to the Arctic areas. Environmental fate modeling has been applied to monitor this phenomenon using parallel zones of atmosphere around the globe as interconnected environments. These zones, shown in many meteorological maps, however, may not be the best way to configure atmospheric transport in air trajectories. The latter could also be covered by connecting a chain of simple model boxes. We aim to study this alternative approach by modeling the trajectory chain using catchment boxes of our FATEMOD model. Polychlorobornanes analyzed in biota of the Barents Sea offered one case to study this modeling alternative, while toxaphene has been and partly still is used massively at southern East Europe and around rivers flowing to the Aral Sea. Pure model substances of three polychlorobornanes (toxaphene congeners P26, P50, and P62) were synthesized, their environmentally important thermal properties measured by differential scanning calorimetry, as evaluated from literature data, and their temperature dependences estimated by the QSPR programs VPLEST, WATSOLU, and TDLKOW. The evaluated property parameters were used to model their atmospheric long-range transport from toxaphene heavy usage areas in Ukraine and Aral/SyrDarja/AmuDarja region areas, through East Europe and Northern Norway (Finnmarken) to the Barents Sea. The time period used for the emission model was June 1997. Usual weather conditions in June were applied in the model, which was constructed by chaining FATEMOD model boxes of the catchment's areas along assumed maximal air flow trajectories. Analysis of the three chlorobornanes in toxaphene mixtures function as a basis

  2. Development of toxic equivalency factors for PCB congeners and the assessment of TCDD and PCB mixtures in rainbow trout

    Science.gov (United States)

    Newsted, John L.; Jones, Paul D.; Giesy, John P.; Crawford, Robert A.; Ankley, Gerald T.; Tillitt, Donald E.; Gooch, Jay W.; Denison, Michael S.

    1995-01-01

    This study was undertaken to evaluate the relationship between mammalian and piscine 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalency factors (TEFs) for PCBs, based on induction of CYP1A enzyme activity, catalytic protein, and mRNA. Rainbow trout administered a single i.p. injection of TCDD had an average (±SD) ED50 of 0.91 ± 0.14 μg TCDD/kg for induction of ethoxyresorufin O-deethylase (EROD) activity. Ortho-substituted PCB congeners 2,3,3′,4,4′-pentachlorobiphenyl (PCB 105), 2,3′,4,4′,5-pentachlorobiphenyl (PCB 118), 2,3,3′4,4′5-hexachlorobiphenyl (PCB !56), and 2,2′3,4,4′,5-hexachlorobiphenyl (PCB 138) did not induce CYP1A activity in rainbow trout. Only three non-ortho-substituted PCBs, i.e., 3,3′4,4′-tetrachlorobiphenyl (PCB 77), 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126), and 3,3′4,4′5,5′-hexachlorobiphenyl (PCB 169) induced CYP1A enzyme activity, protein, and mRNA. The ED50s for induction of EROD activity were calculated as 134, 5.82, and 93.7 μg/kg for PCB 77, PCB 126, and PCB 169, respectively. The TCDD-TEFs based on EROD activity were 0.0006, 0.0014, and 0.0003 for PCB 77, PCB 126, and PCB 169, respectively. Binary mixtures of TCDD and three PCBs were also evaluated. Based on EROD activity and CYP1A protein, mixtures of TCDD and PCB 77 were slightly greater than additive. Mixtures of TCDD-PCB 156 and TCDD-PCB 126 were slightly less than additive. Results from these studies indicate that mammal-derived TEFs will underestimate the potency of planar chlorinated hydrocarbon mixtures to induce the CYP1A catalytic activity in rainbow trout. Also, while interactions among PCB congeners and TCDD were somewhat equivocal, they did not greatly differ from predicted additive responses.

  3. Variation in the strength of reproductive interference from an alien congener to a native species in Taraxacum.

    Science.gov (United States)

    Nishida, Sachiko; Hashimoto, Keisuke; Kanaoka, Masahiro M; Takakura, Ko-Ichi; Nishida, Takayoshi

    2017-01-01

    Reproductive interference (RI) may be a contributing factor to the displacement of native species by an alien congener, and RI strength has been shown theoretically to affect distributional relationships between species. Thus, variations in RI strength from alien to native species result in different consequences of invasions and efforts to conserve native species, but the variations have seldom been examined empirically. We therefore investigated RI strength variations from the alien species Taraxacum officinale and its hybrids to eight populations of native dandelions, four T. japonicum populations and two populations each of two subspecies of T. platycarpum. We examined the association between alien relative abundance and native seed set in field surveys, and we also performed hand-pollination experiments to investigate directly the sensitivity of native flowers to alien pollen. We found that the effect of alien relative abundance on native seed set of even the same native species could differ greatly in different regions, and that the sensitivity of native flowers to alien pollen was also dependent on region. Our results, together with those of previous studies, show that RI from the alien to the native species is strong in regions where the alien species outnumbers the native species and marginal where it does not; this result suggests that alien RI can critically affect distributional relationships between native and alien species. Our study highlights the importance of performing additional empirical investigations of RI strength variation and of giving due attention to alien RI in efforts to conserve regional native biodiversity.

  4. The potential for genetic assimilation of a native dandelion species, Taraxacum ceratophorum (Asteraceae), by the exotic congener T. officinale.

    Science.gov (United States)

    Brock, Marcus T

    2004-05-01

    Exotic plant species can threaten closely related native congeners through asymmetric hybridization and subsequent backcrossing, the process known as genetic assimilation. I explore the initial stages of this process in Taraxacum ceratophorum (Asteraceae), the native alpine dandelion, and the invasive apomict T. officinale. In central Colorado, seven T. ceratophorum populations all occur in sympatry with T. officinale. In one large population on Pennsylvania Mountain, surveys further revealed that flowering phenologies and visiting insect taxa overlap almost completely for both Taraxacum species. Together these results indicated that heterospecific pollen transfer is likely. Crossing experiments showed that T. ceratophorum is an obligate outcrosser, and interspecific hand pollinations resulted in 37.3% seed set. However, molecular analysis of the F1 offspring indicated that only 33.2% of germinating seeds were hybrids; the remainder were selfed offspring produced from a breakdown in self-incompatibility (the mentor effect). Although the mentor effect helps reduce the production of hybrids, the asymmetrical direction of hybridization creates the potential for genetic assimilation of T. ceratophorum by T. officinale.

  5. Passive air monitoring of PCBs and PCNs across East Asia: a comprehensive congener evaluation for source characterization.

    Science.gov (United States)

    Hogarh, Jonathan Nartey; Seike, Nobuyasu; Kobara, Yuso; Habib, Ahsan; Nam, Jae-Jak; Lee, Jong-Sik; Li, Qilu; Liu, Xiang; Li, Jun; Zhang, Gan; Masunaga, Shigeki

    2012-02-01

    A comprehensive congener specific evaluation of polychlorinated biphenyls (PCBs) and polychlorinated naphthalenes (PCNs) in the atmosphere was conducted across East Asia in spring 2008, applying polyurethane foam (PUF) disk passive air sampler (PAS) as monitoring device. Mean concentrations derived for Japan, China and Korea were 184 ± 24, 1100 ± 118, and 156 ± 20 pg m(-3) for ∑(202) PCBs, and 9.5 ± 1.5, 61 ± 6, and 16 ± 2.4 pg m(-3) for ∑(63) PCNs, respectively. Relative to reported data from 2004, the present results suggest that air PCBs concentrations have not changed much in Japan and Korea, while it has increased by one order of magnitude in China. From principal component analysis, combustion emerged highly culpable in contemporary emissions of both PCBs and PCNs across the East Asian sub-region. Another factor derived as important to air PCBs was re-emissions/volatilization. Signals from PCBs formulations were also picked, but their general importance was virtually consigned to the re-emissions/volatilization tendencies. On the contrary, counterpart PCNs formulations did not appear to contribute much to air PCNs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Carnitine congener mildronate protects against stress- and haloperidol-induced impairment in memory and brain protein expression in rats.

    Science.gov (United States)

    Beitnere, Ulrika; Dzirkale, Zane; Isajevs, Sergejs; Rumaks, Juris; Svirskis, Simons; Klusa, Vija

    2014-12-15

    The present study investigates the efficacy of mildronate, a carnitine congener, to protect stress and haloperidol-induced impairment of memory in rats and the expression of brain protein biomarkers involved in synaptic plasticity, such as brain-derived neurotrophic factor (BDNF), acetylcholine esterase and glutamate decarboxylase 67 (GAD67). Two amnesia models were used: 2h immobilization stress and 3-week haloperidol treatment. Stress caused memory impairment in the passive avoidance test and induced a significant 2-fold BDNF elevation in hippocampal and striatal tissues that was completely inhibited by mildronate. Mildronate decreased the level of GAD67 (but not acetylcholine esterase) expression by stress. Haloperidol decrease by a third hippocampal BDNF and acetylcholine esterase (but not GAD67) expression, which was normalized by mildronate; it also reversed the haloperidol-induced memory impairment in Barnes test. The results suggest the usefulness of mildronate as protector against neuronal disturbances caused by stress or haloperidol. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Multivariate toxicity profiles and QSAR modeling of non-dioxin-like PCBs--an investigation of in vitro screening data from ultra-pure congeners.

    Science.gov (United States)

    Stenberg, Mia; Hamers, Timo; Machala, Miroslav; Fonnum, Frode; Stenius, Ulla; Lauy, Al-Anati; van Duursen, Majorie B M; Westerink, Remco H S; Fernandes, Elsa C Antunes; Andersson, Patrik L

    2011-11-01

    The non-dioxin-like PCBs (NDL-PCBs) found in food and human samples have a complex spectrum of adverse effects, but lack a detailed risk assessment. The toxicity profiles of 21 carefully selected PCBs (19 NDL-PCBs) were identified by in vitro screening in 17 different assays on specific endpoints related to neurotoxicity, endocrine disruption and tumor promotion. To ensure that the test results were not affected by polychlorinated dioxins, dibenzofurans or DL-PCB contaminants, the NDL-PCB congeners were thoroughly purified before testing. Principal component analysis (PCA) was used to derive general toxicity profiles from the in vitro screening data. The toxicity profiles indicated different structure-activity relationships (SAR) and distinct mechanisms of action. The analysis also indicated that the NDL-PCBs could be divided into two groups. The first group included generally smaller, ortho-substituted congeners, comprising PCB 28, 47, 51, 52, 53, 95, 100, 101, 104 and 136, with PCB 95, 101 and 136 as generally being most active. The second group comprising PCB 19, 74, 118, 122, 128, 138, 153, 170, 180 and 190 had lower biological activity in many of the assays, except for three endocrine-related assays. The most abundant congeners, PCB 138, 153, 170, 180 and 190, cluster in the second group, and thereby show similar SAR. Two quantitative structure-activity relationship (QSAR) models could be developed that added information to the SAR and could aid in risk assessments of NDL-PCBs. The QSAR models predicted a number of congeners as active and among these e.g., PCB 18, 25, 45 and 49 have been found in food or human samples.

  8. Thermolysis of Iso-Migrastatin and Its Congeners via [3,3]-Sigmatropic Rearrangement: A New Route to the Synthesis of Migrastatin and Its Analogues

    Science.gov (United States)

    Ju, Jianhua; Lim, Si-Kyu; Jiang, Hui; Seo, Jeong-Woo; Her, Yeng; Shen, Ben

    2008-01-01

    Thermolysis of iso-migrastatin (1) under neat heating conditions afforded migrastatin (1a). The reaction is proposed to proceed via a concerted [3,3]-sigmatropic rearrangement by which ring expansion is achieved regio- and enantio-specifically. The general applicability of this reaction was demonstrated with six additional iso-migrastatin congeners (3 – 8), providing a new route to the synthesis of migrastatin analogs (3a – 8a). PMID:17134292

  9. Hepatic in vitro toxicity assessment of PBDE congeners BDE47, BDE153 and BDE154 in Atlantic salmon (Salmo salar L.)

    Energy Technology Data Exchange (ETDEWEB)

    Softeland, Liv, E-mail: lso@nifes.no [National Institute of Nutrition and Seafood Research, PO Box 2029 Nordnes, N-5817 Bergen (Norway); Petersen, Kjell [Computational Biology Unit, Bergen Centre for Computational Science, Uni Research AS, Thormohlensgt 55, N5008 Bergen (Norway); Stavrum, Anne-Kristin [Dept of Clinical Medicine, University of Bergen (Norway); Wu, Terence [Yale University W.M. Keck Biotechnology Resource, 300 George St., Room G001, New Haven, CT 06511 (United States); Olsvik, Pal A. [National Institute of Nutrition and Seafood Research, PO Box 2029 Nordnes, N-5817 Bergen (Norway)

    2011-10-15

    The brominated flame retardant congeners BDE47, BDE153 and BDE154 are among the congeners accumulating to the highest degree in fish. In order to gain knowledge about the toxicological effects of PBDEs in fish, microarray-based transcriptomic and 2D-DIGE/MALDI-TOF/TOF proteomic approaches were used to screen for effects in primary Atlantic salmon hepatocytes exposed to these congeners alone or in combination (PBDE-MIX). A small set of stress related transcripts and proteins were differentially expressed in the PBDE exposed hepatocytes. The PBDE-MIX, and BDE153 to a lesser degree, seems to have induced metabolic disturbances by affecting several pathways related to glucose homeostasis. Further, effects on cell cycle control and proliferation signal pathways in PBDE-MIX-exposed hepatocytes clearly suggest that the PBDE exposure affected cell proliferation processes. CYP1A was 7.41- and 7.37-fold up-regulated in hepatocytes exposed to BDE47 and PBDE-MIX, respectively, and was the only biotransformation pathway affected by the PBDE exposure. The factorial design and PLS regression analyses of the effect of the PBDE-MIX indicated that BDE47 contributed the most to the observed CYP1A response, suggesting that this congener should be incorporated in the toxic equivalent (TEQ) concept in future risk assessment of dioxin-like chemicals. Additionally, a significant up-regulation of the ER-responsive genes VTG and ZP3 was observed in cells exposed to BDE47 and PBDE-MIX. Further analyses suggested that BDE47 and BDE154 have an estrogenic effect in male fish. The data also suggested an antagonistic interaction between BDE153 and BDE154. In conclusion, this study shows that PBDEs can affect several biological systems in Atlantic salmon cells, and demonstrates the need for more studies on the simultaneous exposure to chemical mixtures to identify combined effects of chemicals.

  10. Non-coplanar compact configurations of nuclei and non-compound-nucleus contribution in the fusion cross section of the 12C+93Nb reaction

    Science.gov (United States)

    Chopra, Sahila; Hemdeep, Kaur, Arshdeep; Gupta, Raj K.

    2016-02-01

    Background: In our earlier study of the 12C+93Nb→*105Ag reaction at three near- and below-barrier energies (Ec .m .=41.097 , 47.828, and 54.205 MeV), using the dynamical cluster-decay model (DCM) with various nuclear interaction potentials (the Blocki et al. pocket formula and others derived from the Skyrme energy density formalism) for compact, coplanar (Φc=00 ) nuclei, we found a large non-compound-nucleus (nCN) contribution in the measured fusion cross section of this reaction. Purpose: In the present work, we look for the effect of using non-coplanar, compact configurations (Φc≠00 ), in the Blocki et al. pocket formula of the nuclear proximity potential, on the non-compound-nucleus (nCN) contribution, using the DCM. Methods: Allowing the Φ degree of freedom in the DCM formalism, we calculate the compound-nucleus (CN) and nCN cross sections. The only parameter of the DCM is the neck-length parameter Δ R , which also fits the empirically determined nCN cross section nearly exactly, under the assumption of considering it like a quasifission process where the fragment preformation factor P0=1 . Results: With the Φ degree of freedom included, at the higher two energies the nCN cross section gets enhanced, and hence the pure CN cross section is decreased, since the calculated (total) fusion cross section is fitted to experimental data. The parameter Δ R for the nCN contribution is smaller, and hence the reaction time larger, than for the CN decay process. Also, the contributing angular momentum ℓmax value increases in going from Φc=00 to Φc≠00 for both the CN and nCN processes. The intermediate mass fragments (IMFs), measured up to mass 13 in this reaction, are shown extended up to mass 16, and the fusion-fission (f f ) region is identified as A /2 ±16 , the same as for the Φc=00 case. Conclusions: As a result of enhanced nCN cross section due to Φc≠00 , the CN fusion probability PCN for *105Ag changes its behavior from an increasing to a

  11. Correcting the gas and particle partitioning of PCDD/F congeners in the flue gas of an iron ore sinter plant.

    Science.gov (United States)

    Kuo, Yu-Chieh; Chen, Yu-Cheng; Yang, Jeng-How; Tsai, Perng-Jy; Wang, Lin-Chi; Chang-Chien, Guo-Ping

    2012-03-30

    This study was aimed at developing an approach for correcting the gas and particle partitioning of PCDD/F congeners for samples collected from the flue gas of an iron ore sinter plant. An iron ore sinter plant equipped with an electrostatic precipitator (EP) and a selective catalytic reduction (SCR) was selected. Flue gas samples were collected at EP inlet, EP outlet and SCR outlet. Both particle- and gas-phase PCDD/Fs were analyzed for each collected sample. PCDD/F contents in EP ashes (EP(ash)) were also analyzed and used to correct the gas and particle partitioning of PCDD/F congeners of the collected flue gas samples. Results show that PCDD/Fs in the flue gas were dominated by the gas-phase. Before correction, the removal efficiencies for the gas- and particle-phase PCDD/Fs for EP were -58.1% and 64.3%, respectively, and SCR were 39.4% and 83.9%, respectively. The above results were conflict with the expected results for both EP and SCR indicating the need for correcting the gas and particle partitioning of PCDD/F congeners for all collected flue gas samples. After correction, the removal efficiencies become more reasonable for EP (=4.22% and 97.7%, respectively), and SCR (=54.7% and 62.0%, respectively). The above results confirm the effectiveness of the approach developed by this study. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Levels, congener profile and inventory of polychlorinated biphenyls in sediment from the Songhua River in the vicinity of cement plant, China: a case study.

    Science.gov (United States)

    Cui, Song; Fu, Qiang; Li, Yi-Fan; Li, Wen-Long; Li, Tian-Xiao; Wang, Min; Xing, Zhen-Xiang; Zhang, Lu-Ji

    2016-08-01

    This study investigated the contamination levels, homologue, and congener profiles and evaluated the residue inventory of polychlorinated biphenyls (PCBs) in sediment of the Songhua River in the vicinity of cement plant. The total concentration of detected 35 PCB congeners ranged from 1.12 to 2.19 ng/g dry weight (dw) in sediment, with a mean value of 1.56 ng/g dw, and the concentration of PCBs decreased in the following order: the downstream > cement plant > upstream. The results of total organic carbon (TOC)-normalized PCB concentrations indicate that the sediments have low potential ecological risk in this area. The study results on homologue and congener of PCBs show that the emissions from cement production could be the major sources of PCBs in sediment, and the low-chlorinated PCBs will be exchanged among air, water, and sediment with increasing temperature during summer and flow to downstream with water during the wet season. The spatial density and total burden of PCBs in the surface sediments were 17.2 ng/cm(2) and 1.2 kg, respectively. To our knowledge, this study is the first to explore the pollution characteristics of unintentionally produced PCB emissions from cement industry by means of monitoring sediment samples.

  13. Prenatal exposure to a polychlorinated biphenyl (PCB congener influences fixation duration on biological motion at 4-months-old: a preliminary study.

    Directory of Open Access Journals (Sweden)

    Hirokazu Doi

    Full Text Available Adverse effects of prenatal exposure to polychlorinated biphenyl (PCB congeners on postnatal brain development have been reported in a number of previous studies. However, few studies have examined the effects of prenatal PCB exposure on early social development. The present study sought to increase understanding of the neurotoxicity of PCBs by examining the relationship between PCB congener concentrations in umbilical cord blood and fixation patterns when observing upright and inverted biological motion (BM at four-months after birth. The development of the ability to recognize BM stimuli is considered a hallmark of socio-cognitive development. The results revealed a link between dioxin-like PCB #118 concentration and fixation pattern. Specifically, four-month-olds with a low-level of prenatal exposure to PCB #118 exhibited a preference for the upright BM over inverted BM, whereas those with a relatively high-level of exposure did not. This finding supports the proposal that prenatal PCB exposure impairs the development of social functioning, and indicates the importance of congener-specific analysis in the risk analysis of the adverse effects of PCB exposure on the brain development.

  14. Concentrations and congener profiles of polybrominated diphenyl ethers (PBDEs) in blood plasma from Hong Kong: implications for sources and exposure route.

    Science.gov (United States)

    Wang, Hong-Sheng; Jiang, Guan-Min; Chen, Zhuo-Jia; Du, Jun; Man, Yu-Bon; Giesy, John P; Wong, Chris K C; Wong, Ming-Hung

    2013-10-15

    There was limited information about bioaccumulation of polybrominated diphenyl ethers (PBDEs) in humans of the general population of Hong Kong. Therefore, the present study was conducted to determine concentrations and congener profiles of PBDEs in blood plasma from Hong Kong, evaluate their sources and correlations with other organobrominated compounds, and investigate exposure routes from fish and dust. Concentrations of ∑PBDE22 ranged from 0.56 to 92 ng g(-1), lipid weight (lw), with a median of 5.4 ng g(-1). BDE-47 was the dominant congener, accounting for 26% of ∑PBDE22. Concentrations of PBDE congeners in market fish were significantly (r(2)=0.89, pPBDEs. Furthermore, our data revealed a spatial distribution and terrestrial source of BDE-28 for local people. Results of the present study, which was the first systematic study to investigate concentrations of PBDEs in blood of Hong Kong people, provides useful information to which future measurements can be compared.

  15. Long-range atmospheric transport of PAHs, PCBs and PBDEs to the central and eastern Mediterranean and changes of PCB and PBDE congener patterns in summer 2010

    Science.gov (United States)

    Mulder, Marie D.; Heil, Angelika; Kukučka, Petr; Kuta, Jan; Přibylová, Petra; Prokeš, Roman; Lammel, Gerhard

    2015-06-01

    The central and eastern Mediterranean is a receptor area for persistent organic pollutants (POPs) emitted in western, central and eastern Europe, particularly during summer. Atmospheric concentrations of PCBs, DDXs, PBDEs, penta- and hexachlorobenzene were measured during a ship-borne survey in the summer of 2010. The concentration of PCBs (sum of 7 congeners) was 3.61 (2.08-7.72) pg m-3, of which 6.7% was associated with the particulate phase. The mean concentration of DDT isomers and their metabolites, DDE and DDD, was 2.60 (0.46-7.60) pg m-3 (particulate mass fraction θ = 0.097), of penta- and hexachlorobenzene 0.22 (PBDEs (sum of 8 congeners) 7.31 (2.80-19.89) pg m-3. The air masses studied had been transported mostly across central Europe, some crossing western Europe. The observed changes of PCB congener patterns along transport routes are in agreement with the perception that the reaction with the OH radical is dominating PCB atmospheric lifetime, and indicate an overestimation of the second order gas-phase reaction rate coefficient of PCB153 with OH by structure-activity relationship.

  16. Tissue distribution of HCH and DDT congeners and human health risk associated with consumption of fish collected from Kabul River, Pakistan.

    Science.gov (United States)

    Aamir, Muhammad; Khan, Sardar; Nawab, Javed; Qamar, Zahir; Khan, Anwarzeb

    2016-03-01

    Distribution of hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT) congeners in tissues of four different fish species and their associated potential health risks to local consumers are presented in this paper. The average ∑(HCHs+DDTs) concentration in Glyptothorax punjabensis (214ngg(-1) wet weight (ww)) (carnivores) was found higher than Tor putitora (155ngg(-1) ww) (herbivores). The distribution of ∑(HCHs+DDTs) in all fish tissues was found in order of liver>muscle>stomach>gills. The profile of congeners (β-HCH/∑HCH from 0.29-0.47) indicated that all selected fish species were contaminated with HCH because of its recent usage in the study area. Furthermore, DDT profile ((DDE+DDD)/∑DDT from 0.61-0.78) showed that fish contamination with DDT originated from past usage and long-time degradation mechanism. The average estimated daily dietary intake of ∑HCHs (15.0ngkg(-1) day(-1)) was higher than ∑DDTs (12.5ngkg(-1) day(-1)) by the local consumers via fish consumption. On the basis of both 50th and 95th percentile exposure levels, the carcinogenic hazard ratios for DDT and its congeners were exceeded one (safe limit) for all fish species, indicating a great potential cancer risk for local consumers with life time consumption of contaminated fish collected from Kabul River.

  17. Influence of turkey herpesvirus vaccination on the B-haplotype effect on Marek's disease resistance in 15.B-congenic chickens.

    Science.gov (United States)

    Bacon, L D; Witter, R L

    1992-01-01

    Eight recently developed 15.B congenic lines of chickens were tested for Marek's disease (MD) resistance by intra-abdominal injection of cell-associated preparations of MD virus of a virulent strain (JM), a very virulent strain (Md5), or Md5 after vaccination with turkey herpesvirus (HVT) strain FC126. Chickens of the 15.N congenic line (B15B21 or B21B21) were very resistant to JM-induced MD, in contrast to chickens homozygous for the B-haplotypes 2, 5, 12, 13, 15, or 19. After Md5 infection, more than 88% of the chickens in all of the congenic lines developed MD. However, when chickens were vaccinated with HVT before being inoculated with Md5, the B5 and B12 homozygotes were more resistant to MD than were the B2, B13, or B19 homozygotes, and B15 and B21 homozygotes had intermediate resistance. B5B5 and B2B5 F2 chicks inoculated with HVT and Md5 had a lower prevalence of MD than B2B2 sibs. These results demonstrate that a protocol involving HVT vaccination of chicks followed by infection with very virulent MD virus will allow the detection of B-haplotypes determining MD resistance, some of which are not detectable in unvaccinated chicks challenged with virulent MD.

  18. Single Targeted Exon Mutation Creates a True Congenic Mouse for Competitive Hematopoietic Stem Cell Transplantation: The C57BL/6-CD45.1STEM Mouse

    Directory of Open Access Journals (Sweden)

    Francois E. Mercier

    2016-06-01

    Full Text Available Defining the molecular regulators of hematopoietic stem and progenitor cells (HSPCs requires in vivo functional analyses. Competitive bone marrow transplants (BMTs compare control and test HSPCs to demonstrate the functional role of a genetic change or chemical perturbation. Competitive BMT is enabled by antibodies that specifically recognize hematopoietic cells from congenic mouse strains due to variants of the cell surface protein CD45, designated CD45.1 and CD45.2. The current congenic competitor strain, B6.SJL-Ptprca Pepcb/BoyJ (CD45.1, has a substantial inherent disadvantage in competition against the C57BL/6 (CD45.2 strain, confounding experimental interpretation. Despite backcrossing, the congenic interval over which the B6.SJL-Ptprca Pepcb/BoyJ strain differs is almost 40 Mb encoding ∼300 genes. Here, we demonstrate that a single amino acid change determines the CD45.1 epitope. Further, we report on the single targeted exon mutant (STEM mouse strain, CD45.1STEM, which is functionally equivalent to CD45.2 cells in competitive BMT. This strain will permit the precise definition of functional roles for candidate genes using in vivo HSPC assays.

  19. Analysis of biosurfactants from industrially-viable Pseudomonas strain isolated from crude oil suggests how rhamnolipids congeners affect on emulsification property and antimicrobial activity

    Directory of Open Access Journals (Sweden)

    Palashpriya eDas

    2014-12-01

    Full Text Available Rhamnolipid biosurfactants produced mainly by Pseudomonas sp. had been reported to possess a wide range of potential industrial application. These biosurfactants are produced as monorhamnolipid (MRL and di-rhamnolipid (DRL congeners. The present study deals with rhamnolipid biosurfactants produced by three bacterial isolates from crude oil. Biosurfactants produced by one of the strains (named as IMP67 was found to be very efficacious based on its critical micelle concentration (CMC value and hydrocarbon emulsification property. Strikingly, antimicrobial and anti-biofilm potential of this biosurfactant were higher than biosurfactants produced by other two strains. Thin layer chromatography (TLC analysis and rhamnose quantification showed that the rhamnolipids of IMP67 had more MRL congeners than biosurfactants of the other two strains. Emulsification and antimicrobial actions were affected by manual change of MRL and DRL congener proportions. Increase of MRL proportion enhanced emulsification index and antimicrobial property to Gram negative bacteria. This result indicated that the ratio of MRL and DRL affect the emulsification potentials of rhamnolipids, and suggested that high emulsification potentials might enhance rhamnolipids to penetrate the cell wall of Gram negative bacteria. In consistent, rhamnolipids of IMP67 reduced the MIC of some antibiotics against bacteria, suggesting the potential of biosurfactant as antibiotics synergist.

  20. Analysis of biosurfactants from industrially viable Pseudomonas strain isolated from crude oil suggests how rhamnolipids congeners affect emulsification property and antimicrobial activity.

    Science.gov (United States)

    Das, Palashpriya; Yang, Xin-Ping; Ma, Luyan Z

    2014-01-01

    Rhamnolipid biosurfactants produced mainly by Pseudomonas sp. had been reported to possess a wide range of potential industrial application. These biosurfactants are produced as monorhamnolipid (MRL) and di-rhamnolipid (DRL) congeners. The present study deals with rhamnolipid biosurfactants produced by three bacterial isolates from crude oil. Biosurfactants produced by one of the strains (named as IMP67) was found to be very efficacious based on its critical micelle concentration value and hydrocarbon emulsification property. Strikingly, antimicrobial, and anti-biofilm potential of this biosurfactant were higher than biosurfactants produced by other two strains. Thin layer chromatography analysis and rhamnose quantification showed that the rhamnolipids of IMP67 had more MRL congeners than biosurfactants of the other two strains. Emulsification and antimicrobial actions were affected by manual change of MRL and DRL congener proportions. Increase of MRL proportion enhanced emulsification index and antimicrobial property to Gram negative bacteria. This result indicated that the ratio of MRL and DRL affected the emulsification potentials of rhamnolipids, and suggested that high emulsification potentials might enhance rhamnolipids to penetrate the cell wall of Gram negative bacteria. In line with this finding, rhamnolipids of IMP67 also reduced the MIC of some antibiotics against bacteria, suggesting their synergistic role with the antibiotics.

  1. 轮对在线检测中Tsai异面标定算法研究%Tsai Non-coplanar Calibration Algorithm of Wheel Set Online Detection

    Institute of Scientific and Technical Information of China (English)

    吴开华; 陈康

    2015-01-01

    In wheel set online detection based on structured light projection image technique, the wheel set light-section curves acquired by CCD are heavily distorted. The camera calibration method and calibration precision will directly affect the wheel set online detection precision. According to the nonlinear distortion imaging model, Tsai non-coplanar calibration algorithm based on a moving planar calibration plate was proposed. According to the radial alignment constraint and first-order radial distortion formula, the least square method and Levenberg-Marquardt optimization algorithm were used to calibrate the internal and external parameters of camera. The calibration plate and its three installation location were designed, on the basis of the requirements of on-site installation position and the key point regional distribution of the light-section curves. The extraction of image feature points and the calibration of camera parameters were realized. The experimental results show that the calibration precision of Tsai non-coplanar calibration algorithm was less than 0.1 mm. The calibration precision meets the demands of wheel set online detection.%基于光截图像测量技术的轮对在线检测中,面阵 CCD 摄像机拍摄的轮对光截曲线畸变严重,摄像机标定方法和标定精度直接影响轮对检测精度。本文根据非线性畸变成像模型,提出了一种基于移动平面标定板的 Tsai异面标定算法。根据径向约束条件和一阶径向畸变公式,利用最小二乘法和Levenberg-Marquardt优化算法标定出摄像机内、外部参数。并根据现场安装位置要求和光截曲线关键点区域分布情况,设计了标定板及其三个安装位置,实现了图像特征点提取和摄像机参数的标定。实验结果表明,Tsai异面标定算法标定精度在0.1 mm以内,满足轮对在线检测对标定精度的要求。

  2. Isotope dilution analysis of polychlorinated biphenyls (PCBs) in transformer oil and global commercial PCB formulations by high resolution gas chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Takasuga, Takumi; Senthilkumar, Kurunthachalam; Matsumura, Tohru; Shiozaki, Ken; Sakai, Shin-ichi

    2006-01-01

    Special polychlorinated biphenyls (PCBs) standards (native and isotope labeled) were analyzed by isotope dilution method using HRGC-HRMS. Multiple analysis of special PCBs standards by three different laboratories produced the relative response factors (RRFs) and relative standard deviations (RSDs %) was in the average of 0.979 and 3.86, respectively. Additionally, inter-laboratory analysis of various forms of transformer oil revealed the PCBs concentrations were in the following order; PCBs fortified transformer oil (940-1300 ng/g)>PCB polluted transformer oil (490-680 ng/g)>chemically degraded-transformer oil (480-490 ng/g) and PCBs free oil (ND-17 ng/g). Chemical degradation resulted in an order of magnitude decrease in the PCB concentrations. Specifically, higher chlorinated PCBs degraded into lower chlorinated PCBs. Also, composition of PCBs have been determined in PCB formulations from Japan (Kanechlor), Germany (Clophen), USA (Aroclor), Russia (Sovol) and Poland (Chlorofen). Major PCBs (24-PCB congeners) contributed 54-67%, 55-68%, 16-69%, 71% and 72% in Kanechlor, Clophen, Aroclor, Sovol and Chlorofen, respectively to total PCBs. The homologue pattern of Kanechlor, Aroclor and Clophen in technical fromulation was similar (e.g., Kanechlor-300 resembled to those of Clophen A-30 and Aroclor-1242). Furthermore, congener-specific distributions of major PCBs/dioxin-like PCBs and toxic equivalency quantities (TEQ) were calculated. Based on our tentative assumption calculations, cumulative production of five different technical PCB formulations, WHO-TEQ emission was estimated to be approximately 16.05 tons.

  3. Contamination levels and congener distribution of PCDDs, PCDFs and dioxin-like PCBs in buffalo's milk from Caserta province (Italy).

    Science.gov (United States)

    Esposito, Mauro; Serpe, Francesco Paolo; Neugebauer, Frank; Cavallo, Stefania; Gallo, Pasquale; Colarusso, Germana; Baldi, Loredana; Iovane, Giuseppe; Serpe, Luigi

    2010-04-01

    An extraordinary plan of official control was carried out in 2008 in Campania (Italy) with the aim to monitor polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) levels in buffalo milk and to detect the contaminated farms, most of which are located in Caserta province. For these companies has been ordered seizure and execution of additional analyses has been requested in farms falling in the nearness, within a distance of 3km, for a total of 304 farms examined. Moreover, all non-compliant farms were subjected to a periodic sampling in order to monitor trends in the levels of contamination. In this paper the distribution and the concentrations of 17 PCDD/Fs and 12 dioxin-like PCBs in 460 samples of buffalo milk collected in the province of Caserta (Italy) are presented. The range of WHO-TEQ values for the PCDD/Fs in milk was 0.17pgTEQg(-1)fat and 87.0pgTEQg(-1)fat with a mean value 3.63pgTEQg(-1)fat and medium value 2.25pgTEQg(-1)fat. The concentrations of dioxin-like PCBs in the analysed samples ranged from 0.21pgTEQg(-1)fat to 15.9pgTEQg(-1)fat and the WHO-TEQ values of sum of PCDDs, PCDFs and dl-PCBs ranged from 0.45pgTEQg(-1)fat to 103.0pgTEQg(-1)fat. The geo-referencing analysis allowed to individuate a restricted area of the region object of the present study where is located the majority of the non-compliant farms. The study of the congeners distribution has finally suggested that the likely cause of contamination is to be attributed to the illegal burning of waste. 2010 Elsevier Ltd. All rights reserved.

  4. Cytokine response to the RSV antigen delivered by dendritic cell-directed vaccination in congenic chicken lines.

    Science.gov (United States)

    Mucksová, Jitka; Plachý, Jiří; Staněk, Ondřej; Hejnar, Jiří; Kalina, Jiří; Benešová, Barbora; Trefil, Pavel

    2017-04-05

    Systems of antigen delivery into antigen-presenting cells represent an important novel strategy in chicken vaccine development. In this study, we verified the ability of Rous sarcoma virus (RSV) antigens fused with streptavidin to be targeted by specific biotinylated monoclonal antibody (anti-CD205) into dendritic cells and induce virus-specific protective immunity. The method was tested in four congenic lines of chickens that are either resistant or susceptible to the progressive growth of RSV-induced tumors. Our analyses confirmed that the biot-anti-CD205-SA-FITC complex was internalized by chicken splenocytes. In the cytokine expression profile, several significant differences were evident between RSV-challenged progressor and regressor chicken lines. A significant up-regulation of IL-2, IL-12, IL-15, and IL-18 expression was detected in immunized chickens of both regressor and progressor groups. Of these cytokines, IL-2 and IL-12 were most up-regulated 14 days post-challenge (dpc), while IL-15 and IL-18 were most up-regulated at 28 dpc. On the contrary, IL-10 expression was significantly down-regulated in all immunized groups of progressor chickens at 14 dpc. We detected significant up-regulation of IL-17 in the group of immunized progressors. LITAF down-regulation with iNOS up-regulation was especially observed in the progressor group of immunized chickens that developed large tumors. Based on the increased expression of cytokines specific for activated dendritic cells, we conclude that our system is able to induce partial stimulation of specific cell types involved in cell-mediated immunity.

  5. Four out of eight genes in a mouse chromosome 7 congenic donor region are candidate obesity genes

    Science.gov (United States)

    Sarahan, Kari A.; Fisler, Janis S.

    2011-01-01

    We previously identified a region of mouse chromosome 7 that influences body fat mass in F2 littermates of congenic × background intercrosses. Current analyses revealed that alleles in the donor region of the subcongenic B6.C-D7Mit318 (318) promoted a twofold increase in adiposity in homozygous lines of 318 compared with background C57BL/6ByJ (B6By) mice. Parent-of-origin effects were discounted through cross-fostering studies and an F1 reciprocal cross. Mapping of the donor region revealed that it has a maximal size of 2.8 Mb (minimum 1.8 Mb) and contains a maximum of eight protein coding genes. Quantitative PCR in whole brain, liver, and gonadal white adipose tissue (GWAT) revealed differential expression between genotypes for three genes in females and two genes in males. Alpha-2,8-sialyltransferase 8B (St8sia2) showed reduced 318 mRNA levels in brain for females and males and in GWAT for females only. Both sexes of 318 mice had reduced Repulsive guidance molecule-a (Rgma) expression in GWAT. In brain, Family with sequence similarity 174 member b (Fam174b) had increased expression in 318 females, whereas Chromodomain helicase DNA binding protein 2 (Chd2-2) had reduced expression in 318 males. No donor region genes were differentially expressed in liver. Sequence analysis of coding exons for all genes in the 318 donor region revealed only one single nucleotide polymorphism that produced a nonsynonymous missense mutation, Gln7Pro, in Fam174b. Our findings highlight the difficulty of using expression and sequence to identify quantitative trait genes underlying obesity even in small genomic regions. PMID:21730028

  6. Occurrence of an invasive coral in the southwest Atlantic and comparison with a congener suggest potential niche expansion.

    Science.gov (United States)

    Carlos-Júnior, Lélis A; Neves, Danilo M; Barbosa, Newton P U; Moulton, Timothy P; Creed, Joel C

    2015-06-01

    Tubastraea tagusensis, a coral native to the Galapagos Archipelago, has successfully established and invaded the Brazilian coast where it modifies native tropical rocky shore and coral reef communities. In order to understand the processes underlying the establishment of T. tagusensis, we tested whether Maxent, a tool for species distribution modeling, based on the native range of T. tagusensis correctly forecasted the invasion range of this species in Brazil. The Maxent algorithm was unable to predict the Brazilian coast as a suitable environment for the establishment of T. tagusensis. A comparison between these models and a principal component analysis (PCA) allowed us to examine the environmental dissimilarity between the two occupied regions (native and invaded) and to assess the species' occupied niche breadth. According to the PCA results, lower levels of chlorophyll-a and nitrate on the Atlantic coast segregate the Brazilian and Galapagos environments, implying that T. tagusensis may have expanded its realized niche during the invasion process. We tested the possible realized niche expansion in T. tagusensis by assuming that Tubastraea spp. have similar fundamental niches, which was supported by exploring the environmental space of T. coccinea, a tropical-cosmopolitan congener of T. tagusensis. We believe that the usage of Maxent should be treated with caution, especially when applied to biological invasion (or climate change) scenarios where the target species has a highly localized native (original) distribution, which may represent only a small portion of its fundamental niche, and therefore a violation of a SDM assumption.

  7. Dioxin congener patterns in commercial catfish from the United States and the indication of mineral clays as the potential source.

    Science.gov (United States)

    Huwe, J K; Archer, J C

    2013-01-01

    Since 1991 the US Department of Agriculture (USDA) has conducted annual surveys of pesticide residues in foods under the Agricultural Marketing Service's Pesticide Data Program (PDP). To assess chemical residues in domestically marketed catfish products, 1479 catfish samples were collected during the 2008-2010 PDPs. A subset of 202 samples was analysed for 17 toxic polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs). The average pattern of the individual PCDD/F congener concentrations in the catfish was rather unique in that it had almost no measurable amounts of polychlorinated dibenzofurans (PCDFs), but all PCDDs were present. This pattern was more dominant in the domestically produced catfish products than in the imported products (China/Taiwan). Comparison of the pattern to known sources of PCDD/Fs showed strong similarities to the pattern of PCDD/Fs found in kaolin clays which have often been used as anti-caking agents in animal feeds. To investigate whether catfish feeds may be the source of the PCDD/Fs found in the catfish, archived catfish feed data from a US Food and Drug Administration (USFDA) database were examined. In 61 out of 112 feed samples, the PCDD concentrations were 50 times higher than the PCDF concentrations and resembled the pattern found in the catfish products and in clays mined in the south-eastern United States. Although the source of PCDD/Fs in domestically marketed catfish products cannot be definitively established, mined clay products used in feeds should be considered a likely source and, given the wide concentration range of PCDD/Fs that has been found in clays, a critical control point for PCDD/Fs entrance to the food supply.

  8. Four out of eight genes in a mouse chromosome 7 congenic donor region are candidate obesity genes.

    Science.gov (United States)

    Sarahan, Kari A; Fisler, Janis S; Warden, Craig H

    2011-09-22

    We previously identified a region of mouse chromosome 7 that influences body fat mass in F2 littermates of congenic × background intercrosses. Current analyses revealed that alleles in the donor region of the subcongenic B6.C-D7Mit318 (318) promoted a twofold increase in adiposity in homozygous lines of 318 compared with background C57BL/6ByJ (B6By) mice. Parent-of-origin effects were discounted through cross-fostering studies and an F1 reciprocal cross. Mapping of the donor region revealed that it has a maximal size of 2.8 Mb (minimum 1.8 Mb) and contains a maximum of eight protein coding genes. Quantitative PCR in whole brain, liver, and gonadal white adipose tissue (GWAT) revealed differential expression between genotypes for three genes in females and two genes in males. Alpha-2,8-sialyltransferase 8B (St8sia2) showed reduced 318 mRNA levels in brain for females and males and in GWAT for females only. Both sexes of 318 mice had reduced Repulsive guidance molecule-a (Rgma) expression in GWAT. In brain, Family with sequence similarity 174 member b (Fam174b) had increased expression in 318 females, whereas Chromodomain helicase DNA binding protein 2 (Chd2-2) had reduced expression in 318 males. No donor region genes were differentially expressed in liver. Sequence analysis of coding exons for all genes in the 318 donor region revealed only one single nucleotide polymorphism that produced a nonsynonymous missense mutation, Gln7Pro, in Fam174b. Our findings highlight the difficulty of using expression and sequence to identify quantitative trait genes underlying obesity even in small genomic regions.

  9. Comparison of PBDE congener profiles and concentration levels in human specimens from China and the US and identification of human exposure sources

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In an effort to investigate the status of human exposure to PBDEs in China,available monitoring data in human specimens(including breast milk,serums,and blood) was collected from the general population as well as specific groups that are occupationally exposed.PBDEs exposure profiles and concentration levels were compared with their counterparts in the United States of America.It was found that PBDE burdens in general Chinese population are one order lower and have different congener profiles from that in the US,showing higher percentages of BDE-28 or BDE-153 in human specimens from China.Workers and residents in electronic wastes recycling regions or areas of commercial PBDE manufacturing have the highest PBDE exposure levels reported worldwide,which are close or higher than the exposure levels of the general population in the US. Highly brominated congeners,such as BDE-207 and 209,are among the major PBDE congeners,and BDE-209 has the highest percentage(above 50%) for all occupational populations studied.Principal components analysis(PCA) demonstrates that the exposure of the general population in the US is closely related to penta-BDE while the human burden in China is not.The PBDE in indoor air(gas phase) in the US is highly correlated with the PBDE burden in the general population in the US,indicating a major exposure pathway.For the occupationally exposed populations in China,the congener profiles are closely related to the commercial deca-BDE products.Examination of exposure profiles for general and occupational populations in China suggests that it is essential to include more highly brominated congeners,such as BDE-207 and 209,in future human exposure studies,in order to assess the real burdens and profiles of PBDEs exposure in China.Strict pollution prevention and occupational protection procedures are in need in China to avoid the PBDE contamination problem that has occurred in the US.

  10. DIFFICULTY IN THE FORMATION OF COUNTER-ORBITING HOT JUPITERS FROM NEAR-COPLANAR HIERARCHICAL TRIPLE SYSTEMS: A SUB-STELLAR PERTURBER

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Yuxin; Suto, Yasushi, E-mail: yuxin@utap.phys.s.u-tokyo.ac.jp [Department of Physics, The University of Tokyo, Tokyo 113-0033 (Japan)

    2016-03-20

    Among 100 transiting planets with a measured projected spin–orbit angle λ, several systems are suggested to be counter-orbiting. While these cases may be due to the projection effect, the mechanism that produces a counter-orbiting planet has not been established. A promising scenario for counter-orbiting planets is the extreme eccentricity evolution in near-coplanar hierarchical triple systems with eccentric inner and outer orbits. We examine this scenario in detail by performing a series of systematic numerical simulations, and consider the possibility of forming hot Jupiters (HJs), especially a counter-orbiting one under this mechanism with a distant sub-stellar perturber. We incorporate quadrupole and octupole secular gravitational interaction between the two orbits, and also short-range forces (correction for general relativity, star and inner planetary tide, and rotational distortion) simultaneously. We find that most systems are tidally disrupted and that a small fraction of the surviving planets turn out to be prograde. The formation of counter-orbiting HJs in this scenario is possible only in a very restricted parameter region, and thus is very unlikely in practice.

  11. A Numerical Study of Low-Thrust Limited Power Trajectories between Coplanar Circular Orbits in an Inverse-Square Force Field

    Directory of Open Access Journals (Sweden)

    Sandro da Silva Fernandes

    2012-01-01

    Full Text Available A numerical study of optimal low-thrust limited power trajectories for simple transfer (no rendezvous between circular coplanar orbits in an inverse-square force field is performed by two different classes of algorithms in optimization of trajectories. This study is carried out by means of a direct method based on gradient techniques and by an indirect method based on the second variation theory. The direct approach of the trajectory optimization problem combines the main positive characteristics of two well-known direct methods in optimization of trajectories: the steepest-descent (first-order gradient method and a direct second variation (second-order gradient method. On the other hand, the indirect approach of the trajectory optimization problem involves two different algorithms of the well-known neighboring extremals method. Several radius ratios and transfer durations are considered, and the fuel consumption is taken as the performance criterion. For small-amplitude transfers, the results are compared to the ones provided by a linear analytical theory.

  12. Difficulty in the Formation of Counter-orbiting Hot Jupiters from Near-coplanar Hierarchical Triple Systems: A Sub-stellar Perturber

    Science.gov (United States)

    Xue, Yuxin; Suto, Yasushi

    2016-03-01

    Among 100 transiting planets with a measured projected spin-orbit angle λ, several systems are suggested to be counter-orbiting. While these cases may be due to the projection effect, the mechanism that produces a counter-orbiting planet has not been established. A promising scenario for counter-orbiting planets is the extreme eccentricity evolution in near-coplanar hierarchical triple systems with eccentric inner and outer orbits. We examine this scenario in detail by performing a series of systematic numerical simulations, and consider the possibility of forming hot Jupiters (HJs), especially a counter-orbiting one under this mechanism with a distant sub-stellar perturber. We incorporate quadrupole and octupole secular gravitational interaction between the two orbits, and also short-range forces (correction for general relativity, star and inner planetary tide, and rotational distortion) simultaneously. We find that most systems are tidally disrupted and that a small fraction of the surviving planets turn out to be prograde. The formation of counter-orbiting HJs in this scenario is possible only in a very restricted parameter region, and thus is very unlikely in practice.

  13. Design of Coplanar Waveguide Interdigital Slow Wave Delay Line%共面波导交指慢波延迟线设计

    Institute of Scientific and Technical Information of China (English)

    梅亮; 张华; 王继财

    2012-01-01

    This paper presents a design of coplanar waveguide interdigital slow wave delay line, describes the theory of slow wave delay line, and obtains optimized parameters of delay line by electromagnetic simulating software. The delay line which works on X wave band, has 7λ (about 700 ps) delay on center frequency and insertion loss of 2. 0 dB. The measured results are in good agreement with the simulated ones.%提出了一种共面波导交指慢波延迟线的设计,介绍了慢波延迟线工作原理,利用电磁仿真软件优化得到了延迟线的各项参数.该延迟线工作在x波段,具有中心频率7λ(约700 ps)的延迟,延迟线的插入损耗约2.0 dB.延迟线的实测与仿真结果吻合较好.

  14. Dose-response assessment using the benchmark dose approach of changes in hepatic EROD activity for individual polychlorinated biphenyl congeners

    Energy Technology Data Exchange (ETDEWEB)

    Fattore, E.; Fanelli, R. [' ' Mario Negri' ' Institute for Pharmacological Research, Milan (Italy); Chu, I. [Safe Environments Programme, Healthy Environments and Consumer Safety Branch, Tunney' s Pasture, Ottawa, ON (Canada); Sand, S.; Haakansson, H. [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Falk-Filippson, A. [Swedish Chemicals Inspectorate, Sundbyberg (Sweden)

    2004-09-15

    The benchmark dose (BMD) approach was proposed as an alternative to the no-observedadverse- effect-level (NOAEL) or the lowest-observed-adverse-effect-level (LOAEL) as point of departure (POD) for extrapolation of data from animal studies to the low dose human exposure situation. In the risk assessment process using the NOAEL/LOAEL parameter, the reference dose (RfD) or the admissible daily intake (ADI) is obtained by dividing the NOAEL/LOAEL value by uncertainty factors. The uncertainty factors are incorporated in order to take into account variability in the sensitivity of different species, inter-individual differences in sensitivity within the human population, and variability in experimental data. In the BMD approach a dose-response curve is fitted to experimental data (Figure 1) and the BMD is calculated from the equation of the curve as the dose corresponding to a predetermined change in the response defined as the benchmark response (BMR). The 95% lower confidence bound of the BMD, usually referred to as BMDL, can be used as the POD in the extrapolation process to get a RfD or an ADI. The advantages of using the BMD approach are many. First, all the experimental data are utilized to construct the doseresponse curve; second, the variability and uncertainty are taken into account by incorporating standard deviations of means; and third, it represents a single methodology for cancer and noncancer endpoints. In this study the BMD methodology was applied to evaluate dose-response data of seven chlorinated biphenyl (CB) congeners (Table 1), some of which are dioxin-like while others are not. The data were obtained from subchronic dietary exposure studies in male and female Sprague Dawley rats. Elevation in ethoxyresorufin-O-deethylase (EROD) activity was selected as biological response because it is known to be an endpoint sensitive to the exposure of dioxin-like PCBs. Since this response is not an adverse effect per se, in this paper we will refer to the no

  15. Effects of carnitine and its congeners on eicosanoid discharge from rat cells: implications for release of TNFα

    Directory of Open Access Journals (Sweden)

    Ingrid M. Garrelds

    1993-01-01

    Full Text Available THE acyl carrier coenzyme A (CoA is involved in fatty acid metabolism. The carnitine/CoA ratio is of particular importance in regulating the transport of long-chain fatty acids into mitochondria for oxidation. Also CoA has a role in the formation and breakdown of products from both the cyclooxygenase and lipoxygenase pathways of the precursor arachidonic acid. In the present study the effect of 4 days feeding of 300 mg/kg/day of L-carnitine, acetyl Lcarnitine and propionyl L-carnitine on the basal and calcium ionophore (A23187 stimulated release of arachidonic acid metabolites from rat carrageenin elicited peritoneal cells was investigated. There were two series of experiments carried out. In the first, the harvested peritoneal cell population consisted of less than 90% macrophages and additional polymorphonuclear (PMN leucocytes. The basal release of prostaglandin E2 (PGE2, 6-ketoprostaglandin F1α (6-keto-PGF1α and leukotriene B4 (LTB4 was stimulated by all treatments. The A23187 stimulated release of 6-keto-PGF1α and LTB4 was increased by all three compounds. The 6-keto-PGF1α:TxB2 and 6-keto-PGF1α:LTB4 ratios were increased by carnitine treatment. These results suggested that carnitine could modify the macrophage component of an inflammatory site in vivo. In the second series of experiments the harvested cell population was highly purified (>95% macrophages and none of the compounds fed to the rats caused a change of either eicosanoid or TNFα formation. Moreover the 6-keto-PGF1α:TxB2 and 6-keto-PGF1α:LTB4 ratios were not enhanced by any of the compounds tested. It is conceivable that in the first series the increased ratios 6-keto-PGF1α:TxB2 and 6-keto-PGF1α:LTB4 reflected the effect of carnitine or its congeners on PMN leucocytes rather than on macrophages.

  16. Expression of S100A8 correlates with inflammatory lung disease in congenic mice deficient of the cystic fibrosis transmembrane conductance regulator

    Directory of Open Access Journals (Sweden)

    Keet Mary

    2006-03-01

    Full Text Available Abstract Background Lung disease in cystic fibrosis (CF patients is dominated by chronic inflammation with an early and inappropriate influx of neutrophils causing airway destruction. Congenic C57BL/6 CF mice develop lung inflammatory disease similar to that of patients. In contrast, lungs of congenic BALB/c CF mice remain unaffected. The basis of the neutrophil influx to the airways of CF patients and C57BL/6 mice, and its precipitating factor(s (spontaneous or infection induced remains unclear. Methods The lungs of 20-day old congenic C57BL/6 (before any overt signs of inflammation and BALB/c CF mouse lines maintained in sterile environments were investigated for distinctions in the neutrophil chemokines S100A8 and S100A9 by quantitative RT-PCR and RNA in situ hybridization, that were then correlated to neutrophil numbers. Results The lungs of C57BL/6 CF mice had spontaneous and significant elevation of both neutrophil chemokines S100A8 and S100A9 and a corresponding increase in neutrophils, in the absence of detectable pathogens. In contrast, BALB/c CF mouse lungs maintained under identical conditions, had similar elevations of S100A9 expression and resident neutrophil numbers, but diverged in having normal levels of S100A8. Conclusion The results indicate early and spontaneous lung inflammation in CF mice, whose progression corresponds to increased expression of both S100A8 and S100A9, but not S100A9 alone. Moreover, since both C57BL/6 and BALB/c CF lungs were maintained under identical conditions and had similar elevations in S100A9 and neutrophils, the higher S100A8 expression in the former (or suppression in latter is a result of secondary genetic influences rather than environment or differential infection.

  17. Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in primipara breast milk from Shenzhen and exposure risk for breast-fed infants.

    Science.gov (United States)

    Zhang, Jian Gang; Sun, Xiao Wei; Ai, Hua

    2012-03-01

    This study aimed at revealing the levels of polybrominated diphenyl ethers (PBDEs) in breast milk from primipara in Shenzhen (China), and estimating daily intake of PBDEs for breast-fed infants. Concentrations of 7 PBDEs were measured in 60 breast milk samples by isotope dilution HRGC/HRMS (high-resolution gas chromatography/high-resolution mass spectrometry). The intake of PBDEs for breast-fed infants was estimated based on the infant's daily milk consumption. The range of total concentration of 7 PBDEs congeners in samples was 2.6-188.6 ng g(-1) lipid (mean: 14.8 ng g(-1) lipid; median: 7.2 ng g(-1) lipid). The mean estimated daily intake of PBDEs by breast-fed infants ranged from 9.9 to 335.9 ng kg(-1) body weight (bw) per day (mean: 52.5 ng kg(-1) bw per day; median: 28.6 ng kg(-1) bw per day). The levels of PBDEs body burden in the recruited mothers of Shenzhen were higher than those reported previously for the general population from other areas in China. No significant correlations were found between the body burden of PBDEs and the mothers' age, pre-pregnancy BMI, dietary habits, duration of residence in Shenzhen, weight and length of the newborns. BDE-47 and BDE-153 were major PBDE congeners in milk samples, while the congeners of BDE-183 and BDE-28 were also high in Shenzhen. The situation may be attributed to the special economic pattern including electronic production in Shenzhen in the past three decades. Continuous surveillance on PBDEs levels in human milk is needed in order to accurately evaluate the environmental impact of PBDEs to human health in Shenzhen.

  18. A selective historical review of congener-specific human tissue measurements as sensitive and specific biomarkers of exposure to dioxins and related compounds.

    Science.gov (United States)

    Schecter, A

    1998-04-01

    Estimating internal exposure or dose of dioxins and related chemicals such as dibenzofurans and dioxinlike polychlorinated biphenyls is relatively straightforward in laboratory animals because a known dose is given and the amount absorbed can be measured. In wildlife, direct tissue measurement and measurement of environmental samples have both recently been used to estimate exposure. Until recently, human studies used only indirect indicators such as skin lesions to qualitatively estimate exposure to these chlorinated organic compounds. Environmental measurements have also sometimes been used to estimate human exposure. Dioxins in human tissue were not measured until the 1970s, when 2,3,7,8-tetrachlorodibenzo-p-dioxin was measured in mothers' milk; congener-specific measurement of dioxins and dibenzofurans in tissues (blood, milk, and adipose tissue) of the general population and exposed workers was first performed in the United States in the 1980s. Measurement in a sensitive and specific fashion of the 17 toxic dioxin and dibenzofuran congeners currently found in human tissue from industrial countries began in the 1980s. The use of known chemical standards, capillary columns, high resolution gas chromatography and mass spectrometry (GC-MS) has now become relatively common. GC-MS analysis of blood is currently accepted as the gold standard for estimating human exposure to dioxins. However, analyses are still costly and time consuming, and worldwide there are few qualified laboratories. There is currently a lack of knowledge concerning kinetics at higher and lower exposure levels for most of the toxic dioxin congeners and of levels in target tissues of concern.

  19. Direct shear strength model of rock mass with coplanar intermittent joints%共面断续节理岩体直剪强度特性模型

    Institute of Scientific and Technical Information of China (English)

    胡波; 王思敬; 刘晓丽

    2012-01-01

    采用理论分析和模型试验相结合方法,对共面闭合断续节理岩体直剪强度特性进行分析和研究.引入法向变形协调条件,基于Mohr-Coulomb理论,推导共面断续节理岩体模型的直剪强度公式.模型试验表明:全应力-应变曲线主要经历了线弹性增长、节理面错动、次生裂纹起裂稳态扩展、节理面贯通破坏和残余强度5个阶段;剪切应力峰值和残余强度都随正应力的增大而增大,而变形特性随正应力的变化规律性不强;抗剪峰值强度随节理连通率的增大而减小,低连通率时强度下降速度慢;节理分布形态对强度也有影响,节理在两边分布的试样强度普遍高于节理在中间的;理论计算结果与试验值吻合较好,能较好描述共面断续节理岩体的直剪强度特征.%According to theoretical analysis and model test, the direct shear strength behavior of rock mass with coplanar close intermittent joints was investigated. Through introducing deformation compatibility equation at normal direction, the direct shear strength formulation was deduced based on the Mohr-Coulomb theory. According to the complete stress strain curve obtained from model tests, there are five typical stages in the failure process with linear elastic increment, slippage of the joints, steady development of post-cracking, the coalescence failure of discontinuous joints and the residual strength. The peak and residual strength are increased by the increase of normal stress with poor relationship between deformation property and normal stress. The peak strength decreases with the increase of the joint connectivity rate, and the drop velocity is slow at low connectivity rate. The joint distribution has influence on the strength of rock mass, and the strength of model with joints on edge is bigger than that of the model with joints in the middle. The theoretical calculation results are in good consistency with experimental results to give

  20. Very mild disease phenotype of congenic CftrTgH(neoim)Hgu cystic fibrosis mice

    OpenAIRE

    Leonhard-Marek Sabine; Burmester Marion; Bot Alice; Charizopoulou Nikoletta; Wedekind Dirk; Jansen Silke; Dorsch Martina; Stanke Frauke; Wilke Martina; Tóth Balázs (1985-); de Jonge Hugo R; Hedrich Hans-Jürgen; Breves Gerhard; Tümmler Burkhard

    2008-01-01

    Abstract Background A major boost to cystic fibrosis disease research was given by the generation of various mouse models using gene targeting in embryonal stem cells. Moreover, the introduction of the same mutation on different inbred strains generating congenic strains facilitated the search for modifier genes. From the original CftrTgH(neoim)Hgu mouse model with a divergent genetic background (129/Sv, C57BL/6, HsdOla:MF1) two inbred mutant mouse strains CF/1-CftrTgH(neoim)Hgu and CF/3-Cftr...

  1. Congener specific distribution of polychlorinated dibenzo-p-dioxins and dibenzo-p-furans in ambient air particulates (less than PM10 in Delhi, India

    Directory of Open Access Journals (Sweden)

    Bhupander Kumar

    2012-08-01

    Full Text Available Polychlorinated dibenzo-p-dioxins (PCDDs and polychlorinated dibenzo-p-furans (PCDFs are unintentionally formed during inefficient combustions and as a by-product. Due to their resistance to degradation and their toxic effect on health, PCDD/Fs are listed by the Stockholm Convention as persistent organic pollutants (POPs. Once released into the atmosphere, most of them are adsorbed to air particles and transported away from sources in atmosphere. India signed the Stockholm Convention India agreeing thereby to reduce and eliminate the use of POPs. The German agency for Technical Cooperation helped develop facilities for monitoring POPs at a national level in Delhi. This paper presents the data generated during a training assignment for Central Pollution Control Board officials at the German laboratory. Air borne particulate matter (congeners of PCDD/Fs. The concentrations of ΣPCDD/Fs ranged between 1720-9010 fg m-3 (mean 5559 fg m-3 and their toxic equivalency values ranged from 67 to 460 fg I-toxic equivalent quantities (TEQ m-3, with an average of 239 fg I-TEQ m-3 which was lower than the ambient air standards. The dominant congeners were octachlorinated dibenzo-p-dioxin (OCDD, octachlorinated dibenzo-p-furans (OCDF, 1,2,3,4,6,7,8-heptachlorinated dibenzo- p-furans, and 1,2,3,4,6,7,8-heptachlorinated dibenzo-p-dioxin. The contributions of individual homologs for ΣPCDDs/Fs I-TEQ was in the order of OCDD (31%>HCDF (21%>hexachlorodibenzofurans (13%=OCDF (13%> HCDF (12% and other individual congeners contribute less than 5%. High chlorinated congeners contributed with more than 80% for ΣPCDD/Fs I-TEQ. Rough estimates of tolerable daily intake (TDI shows low health risk of exposure to ΣPCDD/Fs with inhalation of 0.098 pg I-TEQ kg1day1 for adult and 0.152 pg TEQ kg-1day-1 for children, which is much lower than World Health Organization

  2. Precise Side-Chain Engineering of Thienylenevinylene-Benzotriazole-Based Conjugated Polymers with Coplanar Backbone for Organic Field Effect Transistors and CMOS-like Inverters.

    Science.gov (United States)

    Lee, Min-Hye; Kim, Juhwan; Kang, Minji; Kim, Jihong; Kang, Boseok; Hwang, Hansu; Cho, Kilwon; Kim, Dong-Yu

    2017-01-25

    Two donor-acceptor (D-A) alternating conjugated polymers based on thienylenevinylene-benzotriazole (TV-BTz), PTV6B with a linear side chain and PTVEhB with a branched side chain, were synthesized and characterized for organic field effect transistors (OFETs) and complementary metal-oxide-semiconductor (CMOS)-like inverters. According to density functional theory (DFT), polymers based on TV-BTz exhibit a coplanar and rigid structure with no significant twists, which could cause to an increase in charge-carrier mobility in OFETs. Alternating alkyl side chains of the polymers impacted neither the band gap nor the energy level. However, it significantly affected the morphology and crystallinity when the polymer films were thermally annealed. To investigate the effect of thermal annealing on the morphology and crystallinity, we characterized the polymer films using atomic force microscopy (AFM) and 2D-grazing incidence X-ray diffraction (2D-GIWAXD). Fibrillary morphologies with larger domains and increased crystallinity were observed in the polymer films after thermal annealing. These polymers exhibited improved charge-carrier mobilities in annealed films at 200 °C and demonstrated optimal OFET device performance with p-type transport characteristics with charge-carrier mobilities of 1.51 cm(2)/(V s) (PTV6B) and 2.58 cm(2)/(V s) (PTVEhB). Furthermore, CMOS-like inorganic (ZnO)-organic (PTVEhB) hybrid bilayer inverter showed that the inverting voltage (Vinv) was positioned near the ideal switching point at half (1/2) of supplied voltage (VDD) due to fairly balanced p- and n-channels.

  3. Breeding system and spatial isolation from congeners strongly constrain seed set in an insect-pollinated apomictic tree: Sorbus subcuneata (Rosaceae)

    Science.gov (United States)

    Hamston, Tracey J.; Wilson, Robert J.; de Vere, Natasha; Rich, Tim C. G.; Stevens, Jamie R.; Cresswell, James E.

    2017-01-01

    In plants, apomixis results in the production of clonal offspring via seed and can provide reproductive assurance for isolated individuals. However, many apomicts require pollination to develop functional endosperm for successful seed set (pseudogamy) and therefore risk pollination-limitation, particularly in self-incompatible species that require heterospecific pollen. We used microsatellite paternity analysis and hand pollinations to investigate pollen-limitation in Sorbus subcuneata, a threatened endemic tree that co-occurs with its congener, S. admonitor. We confirmed that S. subcuneata is an obligate pseudogamous apomict, but open-pollinated flowers rarely produced seed (flower-to-seed conversion < 1%) even though they rapidly accumulated pollen on their stigmas. Manual heterospecific pollination by S. admonitor resulted in a high flower-to-seed conversion rate (65%), however, we estimate that the ratio of self: heterospecific pollination in open-pollinated flowers was at least 22:1. Despite the efficacy of heterospecific pollination, the contribution of S. admonitor trees to paternity in seed from open-pollinated flowers of S. subcuneata decreased rapidly with the spatial separation between paternal and maternal trees. Conservation efforts aimed at maintaining species with this breeding system must therefore manage the congeners in tandem which will also maintain the potential for rare heterospecific fertilisation that typically cause rapid diversification in these lineages. PMID:28338049

  4. Effect of mono-ortho and di-ortho substituted polychlorinated biphenyl (PCB) congeners on leopard frog survival and sexual development.

    Science.gov (United States)

    Jofré, Mariana Beatriz; Karasov, William H

    2008-02-01

    We tested the effect of mono-ortho and di-ortho PCB congeners on northern leopard frog (Rana pipiens) hatching success, survival and sexual development. Embryos and tadpoles were exposed to two levels (0.5 and 50 microg/l) of two PCBs. PCBs 101 and 70 were selected because they were present in amphibians collected in the Fox River-Green Bay ecosystem and they have the theoretical structural requirements to be able to bind to the estrogen receptor and mediate estrogenic responses. The exposure of leopard frog embryos and tadpoles to PCB 70 and 101 did not significantly affect hatchability, survival, deformities or growth. There were significant departures from the expected 50:50 sex ratio in tadpoles/froglets exposed to PCB 101 and PCB 70. In all the cases of significant departure, the bias was towards higher number of females. Decrease in the proportion of male gonads and increase in the proportion of intersex gonads were observed with increasing PCB tissue concentrations. The effects of PCB congeners on sexual differentiation occur at concentrations higher than observed in frogs in the Fox River/Green Bay ecosystem.

  5. IL-10 Production Is Critical for Sustaining the Expansion of CD5+ B and NKT Cells and Restraining Autoantibody Production in Congenic Lupus-Prone Mice.

    Directory of Open Access Journals (Sweden)

    Yuriy Baglaenko

    Full Text Available The development and progression of systemic lupus erythematosus is mediated by the complex interaction of genetic and environmental factors. To decipher the genetics that contribute to pathogenesis and the production of pathogenic autoantibodies, our lab has focused on the generation of congenic lupus-prone mice derived from the New Zealand Black (NZB strain. Previous work has shown that an NZB-derived chromosome 4 interval spanning 32 to 151 Mb led to expansion of CD5+ B and Natural Killer T (NKT cells, and could suppress autoimmunity when crossed with a lupus-prone mouse strain. Subsequently, it was shown that CD5+ B cells but not NKT cells derived from these mice could suppress the development of pro-inflammatory T cells. In this paper, we aimed to further resolve the genetics that leads to expansion of these two innate-like populations through the creation of additional sub-congenic mice and to characterize the role of IL-10 in the suppression of autoimmunity through the generation of IL-10 knockout mice. We show that expansion of CD5+ B cells and NKT cells localizes to a chromosome 4 interval spanning 91 to 123 Mb, which is distinct from the region that mediates the majority of the suppressive phenotype. We also demonstrate that IL-10 is critical to restraining autoantibody production and surprisingly plays a vital role in supporting the expansion of innate-like populations.

  6. Congener-specific distribution and bioaccumulation of short-chain chlorinated paraffins in sediments and bivalves of the Bohai Sea, China.

    Science.gov (United States)

    Ma, Xindong; Chen, Chen; Zhang, Haijun; Gao, Yuan; Wang, Zhen; Yao, Ziwei; Chen, Jiping; Chen, Jingwen

    2014-02-15

    Short-chain chlorinated paraffins (SCCPs) are a new type of persistent organic pollutants that are of great environmental concern because of their wide distribution. In this study, surface sediments and bivalve samples were collected from the coastal area of the Bohai Sea in China. Total SCCP (ΣSCCP) concentrations in surface sediments and bivalves ranged from 97.4 ng g(-1) dry weight (dw) to 1756.7 ng g(-1) dw and 476.4-3269.5 ng g(-1) dw, respectively. C10-CPs and C11-CPs were the predominant homologue groups in all sediments and bivalves. Specific congener composition analysis and correspondence analysis indicated that the local SCCP source mainly came from CP-42 and CP-52 products, and riverine input had an important function. The biota-sediment accumulation factors of ΣSCCPs for bivalves ranged from 1.08 to 1.61, and a significant correlation indicated that the SCCP congener with higher chlorination degree was more likely to be accumulated in bivalves.

  7. Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in breast milk from Shanghai: implication for exposure route of higher brominated BDEs.

    Science.gov (United States)

    Ma, Shengtao; Yu, Zhiqiang; Zhang, Xiaolan; Ren, Guofa; Peng, Ping'an; Sheng, Guoying; Fu, Jiamo

    2012-07-01

    Breast milk has been widely used as a bioindicator to assess the extent of human exposure to PBDEs via various exposure routes. In this study, 48 breast milk samples were collected from primiparous women in Shanghai city, and 14 PBDEs congeners (BDE-28, -47, -99, -100, -153, -154, -183, -196, -197, -203, -206, -207, -208, and -209) were quantified using gas chromatography-electron capture negative ionization-mass spectrometry. The mean concentration of total PBDEs was 8.6 ng/g lipid weight, and ranged from 1.8 to 26.7 ng/g lipid weight. These concentration levels were similar to those reported in Europe and Asia, but one order of magnitude lower than those in North America. The congener profiles in this study exhibited a specific pattern in human milk found worldwide, BDE-153 and BDE-28 accounted for a relatively higher proportion of lower brominated BDEs (from tri- to hepta-BDEs), whereas higher brominated BDEs (from octa- to deca-BDEs) contributed more than 70% of the total PBDEs. The Spearman's correlation coefficient among higher brominated BDEs showed a positive relationship, and concentration levels of higher brominated BDEs were statistically different between office workers and housewives. Due to relatively higher proportion of PBDEs from octa- to deca-BDEs were detected, air inhalation and dust ingestion might be the major exposure routes of higher brominated BDEs. Further research is needed to clarify the major exposure route of higher brominated BDEs to humans.

  8. Drought tolerance in the alpine dandelion, Taraxacum ceratophorum (Asteraceae), its exotic congener T. officinale, and interspecific hybrids under natural and experimental conditions.

    Science.gov (United States)

    Brock, Marcus T; Galen, Candace

    2005-08-01

    We compared water relations and adaptations to drought stress in native and invasive exotic dandelions, Taraxacum ceratophorum and T. officinale. Photosynthesis (A), transpiration (E), and water use efficiency (WUE; carbon gained/water lost) were measured for the two species under extreme drought in the alpine tundra of Colorado, USA. We also subjected both species and F(1) hybrids to a dry-down experiment to determine how relative physiological performance varied with water availability. Photosynthesis and transpiration in the field were low and did not differ between Taraxacum congeners; however, native T. ceratophorum had higher WUE than T. officinale. After 6 days of greenhouse drought, photosynthesis and transpiration were reduced in T. officinale compared to T. ceratophorum. Taraxacum ceratophorum maintained high WUE under control and drought treatments. Conversely, WUE in T. officinale was highly plastic between watered (low WUE) and dry-down (high WUE) treatments. Hybrids did not exhibit heterosis; instead, they were similar to T. officinale in A and E and intermediate to the parental species in WUE. Overall, results suggest that native dandelions are more drought tolerant than invasive congeners or their hybrids, but have less plasticity in WUE. Arid habitats and occasional drought in mesic sites may provide native dandelions with refugia from negative interactions with invasives.

  9. Levels and congener profiles of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like polychlorinated biphenyls in cow's milk collected in Campania, Italy.

    Science.gov (United States)

    Esposito, M; Cavallo, S; Serpe, F P; D'Ambrosio, R; Gallo, P; Colarusso, G; Pellicanò, R; Baldi, L; Guarino, A; Serpe, L

    2009-11-01

    Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and certain dioxin-like polychlorinated biphenyls (dl-PCBs) are a family of chemically-related lipophilic compounds characterized by similar toxicity. Due to their properties they are universally distributed in the environment and classified as persistent organic pollutants (POPs). From most of studies carried out to evaluate human dietary intake, milk and dairy products result as a major contributors of PCDD/Fs uptake. Of course the main source of milk contamination is animal feeds. Lactating ruminants, cows included, transfer these compounds to the food chain by ingestion of contaminated vegetables or soil. Their resistance to degradation and a high lipophilicity means that PCDD/Fs and dl-PCBs may be accumulated into fat tissues from which they are transferred to milk during lactation period. Seventy-nine cows milk samples, collected in the monitoring plan 2008, were analyzed for PCDD/Fs and dl-PCBs. Eleven milk samples were non-compliant corresponding to five breeding livestock located in Caserta province. The distribution of PCDD/Fs and dl-PCBs congeners in these samples was examined in order to determine the likely sources of dioxins. The results show that the congener profile is characterized by a prevalence of PCDFs in respect of PCDDs, that represents the typical pattern of thermal origin contamination.

  10. The establishment of preliminary safety threshold values for cyanobacteria based on periodic variations in different microcystin congeners in Lake Chaohu, China.

    Science.gov (United States)

    Shang, Lixia; Feng, Muhua; Liu, Feifei; Xu, Xiangen; Ke, Fan; Chen, Xiangchao; Li, Wenchao

    2015-04-01

    As harmful cyanobacterial proliferation threatens the safety of drinking water supplies worldwide, it is essential to establish a safety threshold (ST) for cyanobacteria to control cyanobacterial density effectively in water sources. For this purpose, cyanobacterial abundance, microcystin (MC) production, and environmental parameters were monitored monthly from September 2011 to August 2012 in one drinking water source of Lake Chaohu. The cyanobacterial density ranged from 1400 to 220 000 cells per mL with the succession of two dominant species Microcystis and Dolichospermum, which was determined by water temperature and nutrient loading. The MC concentrations were correlated significantly with the cyanobacterial density and they varied between 0.28 and 8.86 μg L(-1). Therefore, the characteristics of MC cell quotas were classified according to four stages of the development of cyanobacteria, namely: recruitment, multiplication, decline and dormancy. The ST for cyanobacteria was established for different periods based on the MC cell quota and its guideline wherein three commonly monitored MC congeners (MC-LR, -RR and -YR) were considered in the present study. Its reliability was verified in the water source using the data collected between June 2013 and May 2014. The results highlighted the necessity to classify the ST-values in different periods referring to the main MC congeners rather than MC-LR, which will facilitate the management and control of toxic cyanobacterial proliferation in drinking water sources.

  11. Prepulse inhibition (PPI) of tactile startle response in recombinant congenic strains of mice:QTL mapping and comparison with acoustic PPI

    Institute of Scientific and Technical Information of China (English)

    Adam Torkamanzehi; Patricia Boksa; Ridha Joober

    2008-01-01

    Prepulse inhibition (PPI) of the startle response is a psychophysiological measure of sensorimotor gating believed to be cross-modal between different sensory systems.We analyzed the tactile startle response (TSR) and PPI of TSR (tPPD,using light as a prepulse stimulus,in the mouse strains A/J and C57BL/6J and 36 recombinant congenic strains derived from them.Parental strains were significantly different for TSR,but were comparable for tPPI.Among the congenic strains,variation for TSR was significant in both genetic backgrounds,but that of tPPI was significant only for the C57BL/6J background.Provisional mapping for loci modulating TSR and tPPI was carded out.Using mapping data from our previous study on acoustic startle responses (ASR) and PPI of ASR (aPPI),no common markers for aPPI and tPPI were identified.However,some markers were significantly associated with both ASR and TSIL at least in one genetic background.These results indicate cross-modal genetic regulation for the startle response but not for PPI,in these mouse strains.

  12. Distribution of selected PCB congeners in the Babcock Street sewer district: a multimedia approach to identify PCB sources in combined sewer overflows (CSOs) discharging to the Buffalo River, New York.

    Science.gov (United States)

    Loganathan, B G; Irvine, K N; Kannan, K; Pragatheeswaran, V; Sajwan, K S

    1997-08-01

    To evaluate sources of PCBs in combined sewer overflows (CSOs) to the Buffalo River, New York, combined sewage, sanitary flow, atmospheric wet and dry depositions, and street dust samples were collected from the Babcock Street sewer district and analyzed. Total PCB concentrations (sum of the PCB congeners quantitated) in particulate and dissolved phases of sanitary flow were 101-269 ng g-1 dry weight and 50% of the total PCB load in street dust samples. PCB congener composition in the particulate phase of CSOs reflects the congener pattern of the street dusts. In this context, it can be suggested that the local contaminated street dusts are one of the potential sources of PCBs in CSOs, which is a source of PCBs to the Buffalo River.

  13. Experiment Pamir-3. Coplanar emission of high energy gamma-quanta at interaction of hadrons with nuclei of air atoms at energies above 10 to the 7th power GeV

    Science.gov (United States)

    Asatiani, T. L.; Genina, L. E.; Zatsepin, G. T.

    1985-01-01

    A systematic analysis of large gamma families, detected in X-ray emulsion chambers, cases of multicore halos have been observed, and among them five events in which the halo is divided into three of four separate cores with their alignment observed in the target diagram (coplanarity of axes of corresponding electron photon cascades). The halo alignment (tendency to the straight line) leads to the aximuthal asymmetry (thrust). The analysis of lateral and momentum distributions of particles in these families shows that they also have thrust that correlates with the direction of the halo core alignment.

  14. Applications of Kinetic Inductance: Parametric Amplifier & Phase Shifter, 2DEG Coupled Co-planar Structures & Microstrip to Slotline Transition at RF Frequencies

    Science.gov (United States)

    Surdi, Harshad

    capacitvely coupled 2DEG mesa structure. Low temperature experiments were done at 77 K and 10 K with photo-doping the 2DEG. A circuit model of a 2DEG coupled co-planar waveguide model is also proposed and simulated.

  15. Complex suicide by ethanol intoxication and inhalation of fire fumes in an old lady: interdisciplinary elucidation including post-mortem analysis of congener alcohols.

    Science.gov (United States)

    Jungmann, L; Perdekamp, M Grosse; Bohnert, M; Auwärter, V; Pollak, S

    2011-06-15

    An 88-year-old woman committed suicide by drinking a toxic amount of highly concentrated alcohol and setting two rooms of her flat on fire. As there was not enough oxygen, the fire went out, however. At autopsy, no thermal lesions were found on the body, but soot depositions in the airways and a COHb value of 14% pointed to the inhalation of fire fumes. The ethanol concentration in femoral blood was 6.62 per mille. The gastric mucosa was fixed by the ingested alcohol and showed hardly any autolytic changes despite a post-mortem interval of five days. Congener analysis of the gastric contents and the femoral blood indicated the uptake of a fruit distillate or its foreshot.

  16. Gas-phase and particle-phase PCDD/F congener distributions in the flue gas from an iron ore sintering plant.

    Science.gov (United States)

    Liu, Xiaolong; Ye, Meng; Wang, Xue; Liu, Wen; Zhu, Tingyu

    2017-04-01

    The activated carbon injection-circulating fluidized bed (ACI-CFB)-bag filter coupling technique was studied in an iron ore sintering plant. For comparison, the removal efficiencies under the conditions without or with ACI technology were both evaluated. It was found that the polychlorinated dibenzo-p-dioxins and dibenzofuran (PCDD/F) removal efficiency for total international toxic equivalence quantity (I-TEQ) concentration was improved from 91.61% to 97.36% when ACI was employed, revealing that ACI was very conducive to further controlling the PCDD/F emissions. Detailed congener distributions of PCDD/Fs in the gas-phase and particle-phase of the Inlet and Outlet samples were determined. Additionally, the PCDD/F distribution for the Fly ash-with ACI sample of was also studied. Copyright © 2016. Published by Elsevier B.V.

  17. Estimation of Aqueous Solubility (-lgSw) of All Polychlorinated Biphenyl (PCB) Congeners by Density Functional Theory and Position of Cl Substitution (NPCS) Method

    Institute of Scientific and Technical Information of China (English)

    WEI Xiao-Yan; GE Zhi-Gang; WANG Zun-Yao; XU Jiao

    2007-01-01

    Optimization calculations of 209 polychlorinated biphenyls (PCBs) were carried out at the B3LYP/6-31G* level. It was found that there is significant correlation between the Cl substitution position and some structural parameters. Consequently, Cl substitution positions were taken as theoretical descriptors to establish a novel QSPR model for predicting -lgSw of all PCB congeners. The model achieved in this work contains four variables, of which r2 = 0.9527, q2 = 0.9490 and SD = 0.25 with large t values. In addition, the variation inflation factors (VIFs) of variables in this model are all less than 5.0, suggesting high accuracy of the -lgSw predicting model. And the results of cross-validation test and method validation also show that the model exhibits optimum stability and better predictive capability than that from the AM1 method.

  18. The invasive plant Alternanthera philoxeroides was suppressed more intensively than its native congener by a native generalist: implications for the biotic resistance hypothesis.

    Science.gov (United States)

    Fan, Shufeng; Yu, Dan; Liu, Chunhua

    2013-01-01

    Prior studies on preferences of native herbivores for native or exotic plants have tested both the enemy release hypothesis and the biotic resistance hypothesis and have reported inconsistent results. The different levels of resistance of native and exotic plants to native herbivores could resolve this controversy, but little attention has been paid to this issue. In this study, we investigated population performance, photosynthesis, leaf nitrogen concentration, and the constitutive and induced resistances of the successful invasive plant, Alternanthera philoxeroides, and its native congener, Alternanthera sessilis, in the presence of three population densities of the grasshopper, Atractomorpha sinensis. When the grasshopper was absent, leaf biomass, total biomass, photosynthesis, and leaf nitrogen concentration of A. philoxeroides were higher than those of A. sessilis. However, the morphological and physiological performances of A. philoxeroides were all decreased more intensively than A. sessilis after herbivory by grasshoppers. Especially as the concentrations of constitutive lignin and cellulose in leaf of A. philoxeroides were higher than A. sessilis, A. philoxeroides exhibited increased leaf lignin concentration to reduce its palatability only at severe herbivore load, whereas, leaf lignin, cellulose, and polyphenolic concentrations of A. sessilis all increased with increasing herbivory pressure, and cellulose and polyphenolic concentrations were higher in A. sessilis than in A. philoxeroides after herbivory. Our study indicated that the capability of the invasive plant to respond to native insect damage was lower than the native plant, and the invasive plant was suppressed more intensively than its native congener by the native insect. Our results support the biotic resistance hypothesis and suggest that native herbivores can constrain the abundance and reduce the adverse effects of invasive species.

  19. Congener-specific analysis of polychlorinated naphthalenes (PCNs) in the major Chinese technical PCB formulation from a stored Chinese electrical capacitor.

    Science.gov (United States)

    Huang, Jun; Yu, Gang; Yamauchi, Makoto; Matsumura, Toru; Yamazaki, Norimasa; Weber, Roland

    2015-10-01

    Impurity of polychlorinated naphthalenes (PCNs) in commercial polychlorinated biphenyl (PCB) formulations has been recognized as a relevant source of PCNs in the environment. Congener-specific analysis of most main PCB formulations has been accomplished previously, excluding the Chinese product. The insulating oil in a stored Chinese electric capacitor containing the major Chinese technical formulation "PCB3" was sampled and tested by isotope dilution technology using high-resolution gas chromatography coupled to high-resolution mass spectrometry (HRGC/HRMS). The detected concentration of PCNs in the Chinese PCB oil sample was 1,307.5 μg/g and therefore significantly higher than that reported in PCB formulations from other countries, as well as that in the transformer oil (ASKAREL Nr 1740) additionally tested in the present study for comparison. Based on the measurement, the total amount of PCNs in Chinese PCB3 oil is estimated to be 7.8 t, which would mean only 0.005 % of global production of PCNs of 150,000 t. The homolog profile is similar to those of PCN in Aroclor 1262 and Clophen A40, where the contributions from hexa-CNs and hepta-CNs are predominant and accounted for similar proportions. The Toxic Equivalent Quantity (TEQ) concentration of dioxin-like PCN congeners is 0.47 μg TEQ/g, with the dominant contributors of CN-73 and CN-66/67. This TEQ content from PCN is higher than that in most other PCB formulations with the exemption of the Russian Sovol formulation. The total TEQ in the historic 6,000 t of the Chinese PCB3 formulation is estimated to be 2.8 kg TEQ.

  20. In vitro study on the agonistic and antagonistic activities of bisphenol-S and other bisphenol-A congeners and derivatives via nuclear receptors

    Energy Technology Data Exchange (ETDEWEB)

    Molina-Molina, José-Manuel, E-mail: molinajm@ugr.es [Laboratory of Medical Investigations, San Cecilio University Hospital, University of Granada, Cíber en Epidemiología y Salud Pública (CIBERESP), Granada E-18071 (Spain); Amaya, Esperanza [Laboratory of Medical Investigations, San Cecilio University Hospital, University of Granada, Cíber en Epidemiología y Salud Pública (CIBERESP), Granada E-18071 (Spain); Grimaldi, Marina [INSERM, U896, Montpellier F-34298 (France); Université de Montpellier I, Montpellier F-34298 (France); Sáenz, José-María; Real, Macarena; Fernández, Mariana F. [Laboratory of Medical Investigations, San Cecilio University Hospital, University of Granada, Cíber en Epidemiología y Salud Pública (CIBERESP), Granada E-18071 (Spain); Balaguer, Patrick [INSERM, U896, Montpellier F-34298 (France); Université de Montpellier I, Montpellier F-34298 (France); Olea, Nicolás [Laboratory of Medical Investigations, San Cecilio University Hospital, University of Granada, Cíber en Epidemiología y Salud Pública (CIBERESP), Granada E-18071 (Spain)

    2013-10-01

    Bisphenols are a group of chemicals structurally similar to bisphenol-A (BPA) in current use as the primary raw material in the production of polycarbonate and epoxy resins. Some bisphenols are intended to replace BPA in several industrial applications. This is the case of bisphenol-S (BPS), which has an excellent stability at high temperature and resistance to sunlight. Studies on the endocrine properties of BPS have focused on its interaction with human estrogen receptor alpha (hERα), but information on its interaction with other nuclear receptors is scarce. The aim of this study was to investigate interactions of BPS, BPF, BPA and its halogenated derivatives, tetrachlorobisphenol A (TCBPA), and tetrabromobisphenol A (TBBPA), with human estrogen receptors (hERα and hERβ), androgen receptor (hAR), and pregnane X receptor (hPXR), using a panel of in vitro bioassays based on competitive binding to nuclear receptors (NRs), reporter gene expression, and cell proliferation assessment. BPS, BPF, and BPA efficiently activated both ERs, while TCBPA behaved as weak hERα agonist. Unlike BPF and BPA, BPS was more active in the hERβ versus hERα assay. BPF and BPA were full hAR antagonists (BPA > BPF), whereas BPA and BPS were weak hAR agonists. Only BPA, TCBPA, and TBBPA, were hPXR agonists (TCBPA > TBBPA > BPA). These findings provide evidence that BPA congeners and derivatives disrupt multiple NRs and may therefore interfere with the endocrine system. Hence, further research is needed to evaluate the potential endocrine-disrupting activity of putative BPA substitutes. - Highlights: • We investigated the agonist/antagonist activities of BPS, BPF, BPA, TCBPA and TBBPA. • The direct interaction of these compounds with hERα, hERβ, hAR and hPXR was studied. • BPA congeners and derivatives were found to disrupt multiple NRs. • Further evaluation of their role as endocrine-disrupting chemicals is needed.

  1. [CT guidance (125)I seed implantation for pelvic recurrent rectal cancer assisted by 3D printing individual non-coplanar template].

    Science.gov (United States)

    Wang, H; Wang, J J; Jiang, Y L; Tian, S Q; Ji, Z; Guo, F X; Sun, H T; Fan, J H; Xu, Y P

    2016-12-20

    Objective: To analyze the difference of dosimetric parameters between pre-plan and post-plan of (125)I radioactive seed implantation assisted by 3D printing individual non-coplanar template (3D printing template) for locally recurrent rectal cancer (LRRC). Methods: From February 2016 to April 2016, a total of 10 patients with locally recurrent rectal cancer received (125)I seeds implantation under CT guidance assisted by 3D printing template in Department of Radiation Oncology, Peking University Third Hospital.Each patient underwent CT simulation, three-dimentional treatment planning pre-implantation, 3D printing template design, radioactive seed implantation assisted by 3D printing template and dosimetric verification post implantation. The median activity of seed was 0.63 mCi (0.58 to 0.7 mCi) (2.15- 2.59×10(7) Bq), and the median number of seeds was 80 (19 to 192). D90, D100, V100, V150, CI, EI, HI, D5cc, D2cc of bladder and bowel of pre-plan and post-plan were calculated, respectively.Paired t test was used to evaluate the difference of dosimetric parameters between pre-plan and post-plan. Results: The median D90 of pre-plan and post-plan were 13 761.0 and 12 798.8 cGy, respectively.The median D100 of pre-plan and post-plan were 5 293.6 and 5 397.9 cGy, respectively.The median V100 of pre-plan and post-plan were 90.0% and 90.0%, respectively.The median V150 of pre-plan and post-plan were 63.8% and 62.4%, respectively.The median CI of pre-plan and post-plan were 0.73 and 0.67.The median EI of pre-plan and post-plan were 0.22 and 0.30, respectively. The median HI of pre-plan and post-plan were 0.29 and 0.31.The median bladder D2cc of pre-plan and post-plan were 3 088.8 and 4 240.4 cGy, respectively.The median bowel D2cc of pre-plan and post-plan were 7 051.6 and 7 903.9 cGy, respectively. Conclusions: 3D printing template might be helpful for locally recurrent rectal cancer patients who received (125)I radioactive seed implantation assisted by 3D printing

  2. Congener-specific analysis of the accumulation of polychlorinated biphenyls (PCBs) by aquatic organisms in the maximum turbidity zone of the St. Lawrence estuary, Québec, Canada.

    Science.gov (United States)

    Gagnon, M M; Dodson, J J; Comba, M E; Kaiser, K L

    1990-11-01

    The polychlorinated biphenyl (PCB) contamination of the biota of the St. Lawrence estuary maximum turbidity zone (MTZ) was investigated. The species analyzed consist of zooplankton (mostly Neomysis americana), larval smelt (Osmerus mordax), juvenile smelt, juvenile tomcod (Microgadus tomcod) and adult smelt, tomcod and capelin (Mallotus villosus). A significant increase in total PCB contamination from zooplankton to all fish developmental stages indicates that the St. Lawrence MTZ is a site of significant PCB contamination. The total PCB contamination of adult smelt and tomcod sampled in the St. Lawrence MTZ was greater than the limit of 0.1 ppm set by the International Joint Commission for the protection of predators. For zooplankton, tomcod and capelin, significant correlations were found between lipid content and PCB contamination. The congener-specific analyses showed that the bioconcentration factor of the individual congeners varied with the species involved and with the molecular structure of the congener. It was found that the chlorine atoms in positions 2, 4 and 5 on at least one phenyl ring of the PCB molecule was a dominant factor causing accumulation of PCBs in aquatic organisms. The pattern of PCB congeners found in beluga (Delphinapterus leucas) whale tissues is similar to the PCB pattern found in the St. Lawrence estuary MTZ biota.

  3. Mapping of a chromosome 12 region associated with airway hyperresponsiveness in a recombinant congenic mouse strain and selection of potential candidate genes by expression and sequence variation analyses.

    Directory of Open Access Journals (Sweden)

    Cynthia Kanagaratham

    Full Text Available In a previous study we determined that BcA86 mice, a strain belonging to a panel of AcB/BcA recombinant congenic strains, have an airway responsiveness phenotype resembling mice from the airway hyperresponsive A/J strain. The majority of the BcA86 genome is however from the hyporesponsive C57BL/6J strain. The aim of this study was to identify candidate regions and genes associated with airway hyperresponsiveness (AHR by quantitative trait locus (QTL analysis using the BcA86 strain. Airway responsiveness of 205 F2 mice generated from backcrossing BcA86 strain to C57BL/6J strain was measured and used for QTL analysis to identify genomic regions in linkage with AHR. Consomic mice for the QTL containing chromosomes were phenotyped to study the contribution of each chromosome to lung responsiveness. Candidate genes within the QTL were selected based on expression differences in mRNA from whole lungs, and the presence of coding non-synonymous mutations that were predicted to have a functional effect by amino acid substitution prediction tools. One QTL for AHR was identified on Chromosome 12 with its 95% confidence interval ranging from 54.6 to 82.6 Mbp and a maximum LOD score of 5.11 (p = 3.68 × 10(-3. We confirmed that the genotype of mouse Chromosome 12 is an important determinant of lung responsiveness using a Chromosome 12 substitution strain. Mice with an A/J Chromosome 12 on a C57BL/6J background have an AHR phenotype similar to hyperresponsive strains A/J and BcA86. Within the QTL, genes with deleterious coding variants, such as Foxa1, and genes with expression differences, such as Mettl21d and Snapc1, were selected as possible candidates for the AHR phenotype. Overall, through QTL analysis of a recombinant congenic strain, microarray analysis and coding variant analysis we identified Chromosome 12 and three potential candidate genes to be in linkage with airway responsiveness.

  4. 特发性胸椎脊柱侧凸共平面矫形的原理与疗效%Vertebral Coplanar alignment for correction of thoracic scoliosis: techniques and results

    Institute of Scientific and Technical Information of China (English)

    邱勇; 朱锋; 王斌; 俞杨; 朱泽章; 钱邦平; 赵清华; 马薇薇

    2010-01-01

    Objective To prospectively explore the techniques and correction results of the method of vertebral coplanar alignment (VCA) in posterior correction for thoracic scoliosis. Methods Between June 2008 to March 2009, 27 patients with idiopathic thoracic scoliosis were selected to undergo posterior pedicle screw fixation with assistance of Coplanar system. There were 26 females and 1 male with the average age of 15.9 years(ranged 11-23 years). There were type 1 in 25 cases and type 2 in two cases. The levels of fusion were established according to the Lenke criteria. The average preoperative coronal Cobb angle was 49°(ranged 40°-70° ). During the procedure, the pedicle screws were inserted in each involved levels on the convex side, an extended Coplanar tube was screwed in line with screw axis to each screws. Then two rigid bars were inserted through the uppermost part of the slotted tube sequentially. As the bar was gently driven down toward the bottom end, the pedicle screws axis started to converge in the straight line, correcting translation and rotation. Spacers were inserted into the slots of the tubes to achieve the ideal physiologic thoracic kyphosis. Once the rod was fixated in the concave side of the main curve, the Coplanar system could be removed. Results The mean postoperative Cobb angle was 14° (ranged 6°-25°), representing the correction rate of 70.7%. The average duration of surgery was 245 min (ranged 210-300 min) and a mean estimated blood loss was 1500 ml (ranged 600-2100 ml). The duration of follow-up averaged 15 (12-18) months. The loss of correction at last follow-up was 3° with the loss of correction rate of 6.1%. In the sagittal plane, the thoracic kyphosis was restored from 18° to 25°. No coronal or sagittal plane decompensation occurred. No thoraeoplasties were necessary to correct the residual rib hump. There was no death, infection and neurological complications. Conclusion The Coplanar is a new technique for the correction of

  5. Time trends and congener profiles of PCDD/Fs, PCBs, and PBDEs in Baltic herring off the coast of Finland during 1978-2009.

    Science.gov (United States)

    Airaksinen, R; Hallikainen, A; Rantakokko, P; Ruokojärvi, P; Vuorinen, P J; Parmanne, R; Verta, M; Mannio, J; Kiviranta, H

    2014-11-01

    In Finland, consumption of Baltic fatty fish may lead to high exposure to persistent organic pollutants (POPs), which might have hazardous health effects. Monitoring of POPs in Baltic fish enables the health authorities to keep dietary advice on fish consumption up to date. In this study, which is a compilation of analytical data from earlier studies, time trends and congener profiles of polychlorinated dioxins and furans (PCDD/Fs) and biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in Baltic herring are reported. Altogether 344 samples of Baltic herring from 1978-2009 were collected across the Finnish coast of the Baltic Sea. The chemical analysis was performed in an accredited testing laboratory with high resolution gas chromatography mass spectrometry. During the 31-year period, PCDD/F and PCB concentrations decreased on approximately 80%, from approximately 20 to 5 pg/g fw, expressed as WHO2005 TEQ. The PBDE concentrations experienced a 4-10 fold increase during late 1980s-early 1990s, and declined to 1978s levels of approximately 2 ng/g fw by 2009. The current concentrations of PCDD/Fs, PCBs and PBDEs in Baltic herring are relatively low, and mostly below EU maximum accepted levels, and are expected to continue decreasing. In the future, it may be possible to re-evaluate the consumption restrictions for this specific Baltic fatty fish.

  6. Cadmium effects on transcriptional expression of rhlB/rhlC genes and congener distribution of monorhamnolipid and dirhamnolipid in Pseudomonas aeruginosa IGB83.

    Science.gov (United States)

    Neilson, Julia W; Zhang, Lin; Veres-Schalnat, Tracey A; Chandler, Kevin B; Neilson, Charlotte H; Crispin, Jennifer D; Pemberton, Jeanne E; Maier, Raina M

    2010-10-01

    While variable production of the biosurfactant, rhamnolipid, by Pseudomonas aeruginosa has been shown to be dependent on growth conditions, no research has evaluated potential relationships between rhamnolipid production and the presence of heavy metals. The current investigation evaluates the influence of Cd(2+) on rhamnolipid synthesis. Cultures grown in the presence of 0.45 and 0.89 mM Cd(2+) were monitored for rhlB/rhlC expression, rhamnolipid yield, and the ratio of monorhamnolipid (RL1) and dirhamnolipid (RL2) produced. Results show a Cd-induced enhancement of rhlB expression in mid-stationary phase (53 h). In addition, sustained production of rhamnolipid through late stationary growth phase (96 h) was observed for Cd-amended cultures, unlike Cd-free control cultures that ceased rhamnolipid production by mid-stationary growth phase. Most significant was an observed increase in the ratio of RL2 to RL1 congeners produced by cultures grown in the presence of Cd(2+). Previous results have shown that the complexation constant for RL2-Cd is several orders of magnitude larger than that of RL1-Cd thus the preferential production of RL2 in the presence of Cd(2+) impacts its bioavailability and toxicity both for the cell and in the surrounding environment.

  7. Inhibitory effects of whisky congeners on IgE-mediated degranulation in rat basophilic leukemia RBL-2H3 cells and passive cutaneous anaphylaxis reaction in mice.

    Science.gov (United States)

    Itoh, Tomohiro; Tsukane, Mariko; Koike, Minako; Nakamura, Chizu; Ohguchi, Kenji; Ito, Masafumi; Akao, Yukihiro; Koshimizu, Seiichi; Nozawa, Yoshinori; Wakimoto, Toshiyuki; Nukaya, Haruo; Suwa, Yoshihide

    2010-06-23

    Whisky is matured in oak casks. Many nonvolatile substances (whisky congeners, WC) seep from the oak cask during the maturing process. In this study, three antiallergic agents (syringaldehyde, SA; lyoniresinol, Lyo; and ellagic acid, EA) were isolated from WC. Treatment with SA, Lyo, and EA reduced the elevation of intracellular free Ca(2+) concentration ([Ca(2+)]i) and intracellular ROS production caused by FcepsilonRI activation. The inhibitions of the elevation of [Ca(2+)]i and intracellular ROS production by SA and Lyo were mainly due to the suppression of the NADPH oxidase activity and scavenging of the produced radical, respectively. On the other hand, EA inactivated spleen tyrosine kinase and led to the inhibition of the elevation of [Ca(2+)]i and intracellular ROS production. Furthermore, it was found that WC strongly inhibited IgE binding to the FcepsilonRIalpha chain, whereas SA, Lyo, and EA did not indicate this inhibitory effect. These results suggest that WC inhibits allergic reactions through multiple mechanisms. To disclose the in vivo effects of WC, SA, Lyo, and EA, these compounds were administered to type I allergic model mice, and the passive cutaneous anaphylaxis (PCA) reaction was measured. These compounds remarkably suppressed the PCA reaction. Taken together, these findings suggest that WC seemed to be beneficial to ameliorate allergic reactions.

  8. Identification of the Gasa3 and Gasa4 autoimmune gastritis susceptibility genes using congenic mice and partitioned, segregative and interaction analyses.

    Science.gov (United States)

    Silveira, P A; Wilson, W E; Esteban, L M; Jordan, M A; Hawke, C G; van Driel, I R; Baxter, A G

    2001-12-01

    BALB/c mice thymectomized on their third day of life develop a high incidence of experimental autoimmune gastritis (EAG) which closely resembles human chronic atrophic (type A, autoimmune) gastritis. Linkage analysis of (BALB/cCrSlcxC57BL/6)F2 mice previously demonstrated that the Gasa1 and Gasa2 genes on distal Chromosome (Chr) 4 have major effects on the development of EAG in this murine model, while other loci displayed a trend towards linkage. Here, we implemented partitioned chi(2)-analysis in order to develop a better understanding of the genotypes contributing to susceptibility and resistance at each linkage region. This approach revealed that linkage of Gasa1 and Gasa2 to EAG was due to codominant and recessive BALB/cCrSlc alleles, respectively. To identify additional EAG susceptibility genes, separate linkage studies were performed on Gasa1 heterozygotes and Gasa2 C57BL/6 homozygotes plus heterozygotes so as to minimize the effects of these disease genes. The enhanced sensitivity of these analyses confirmed the existence of a third EAG susceptibility gene (designated Gasa3) on Chr 6. Epistatic interactions between the Gasa2 EAG susceptibility gene and the H2 were also identified, and the presence of an H2-linked susceptibility gene (Gasa4) confirmed by analysis of H2 congenic mice.

  9. Differential effects of the adenosine A1 receptor agonist adenosine amine congener on renal, femoral and carotid vascular conductance in preterm fetal sheep.

    Science.gov (United States)

    Booth, Lindsea C; Tummers, Leonie; Jensen, Ellen C; Barrett, Carolyn J; Malpas, Simon C; Gunn, Alistair J; Bennet, Laura

    2008-11-01

    1. Adenosine A(1) receptor activation is critical for endogenous neuroprotection from hypoxia-ischaemia, raising the possibility that treatment with A(1) receptor agonists may be an effective physiological protection strategy for vulnerable preterm infants. However, the A(1) receptor can mediate unwanted systemic effects, including vasoconstriction of the afferent glomerular arteriole. There is limited information on whether this occurs at doses that improve cerebral perfusion in the immature brain. 2. Therefore, in the present study, we examined whether infusion of the selective A(1) receptor agonist adenosine amine congener (ADAC) is associated with reduced renal perfusion in chronically instrumented preterm (0.7 gestation) fetal sheep. In the present study, ADAC was given in successive doses of 2.5, 5.0 and 15.0 microg, 45 min apart. 3. Treatment with ADAC was associated with a marked reduction in renal vascular conductance (and blood flow), whereas carotid conductance was increased and there was no significant effect on femoral conductance. In contrast with the stable effects of increasing ADAC dose on vascular conductance, there was a significant dose-related fall in fetal heart rate and blood pressure. 4. In conclusion, these short-term data support the concern that A(1) receptor agonist infusion can selectively impair renal perfusion, even at low doses.

  10. Distribution and congener profiles of short-chain chlorinated paraffins in indoor/outdoor glass window surface films and their film-air partitioning in Beijing, China.

    Science.gov (United States)

    Gao, Wei; Wu, Jing; Wang, Yawei; Jiang, Guibin

    2016-02-01

    Short-chain chlorinated paraffins (SCCPs) are a group of n-alkanes with carbon chain length of 10-13. In this work, paired indoor/outdoor samples of organic films on window glass surfaces from urban buildings in Beijing, China, were collected to measure the concentrations and congener distributions of SCCPs. The total SCCP levels ranged from 337 ng/m(2) to 114 μg/m(2), with total organic carbon (TOC) normalized concentrations of 365 μg/m(2)-365 mg/m(2). Overall, the concentrations of SCCPs on the interior films were higher than the concentrations on the exterior films, suggesting an important indoor environmental exposure of SCCPs to the general public. A significant linear relationship was found between the SCCP concentrations and TOC, with a correlation coefficient of R = 0.34 (p < 0.01). A film-air partitioning model suggests that the indoor gas-phase SCCPs are related to their corresponding window film levels.

  11. Accumulation of microcystin congeners in different aquatic plants and crops--a case study from lake Amatitlán, Guatemala.

    Science.gov (United States)

    Romero-Oliva, Claudia Suseth; Contardo-Jara, Valeska; Block, Tobias; Pflugmacher, Stephan

    2014-04-01

    Microcystins (MCs) fate in natural environments can lead to its transfer into aquatic organisms, e.g. aquatic plants. Moreover, lakes in several countries sustain agriculture activities posing a serious health threat for the public. The case of Lake Amatitlán in Guatemala, was addressed to better understand MCs accumulation of four aquatic plants (Polygonum portoricensis, Eichhornia crassipes, Typha sp. and Hydrilla verticillata) coexisting with Microcystis aeruginosa blooms. These findings were further corroborated with an uptake/accumulation laboratory study. Finally crop products (Solanum lycopersicum and Capsicum annuum) irrigated with lake water were also evaluated for MCs. The obtained results suggest that Lake Amatitlán is highly contaminated with MCs (intra- and extracellular 1931 and 90 µg/L, respectively). In fruits of S. lycopersicum and C. annuum a concentration of 1.16 and 1.03 µg/kg dry weight (DW), respectively could be detected. All four aquatic plants showed a high MCs uptake capacity based on obtained bioconcentration factors (BCF) 165, 18, 16 and 11, respectively. These results were further corroborated in a laboratory study with 30 percent of total MCs taken up by H. verticillata within just 7 days. Additionally it was evidenced that all plants accumulated more MC-LR than other MCs congeners. Monitoring of crop products irrigated with lake water needs further consideration.

  12. Bioaccumulation of six PCB indicator congeners in a heavily polluted water reservoir in Eastern Slovakia: tissue-specific distribution in fish and their parasites.

    Science.gov (United States)

    Brázová, Tímea; Hanzelová, Vladimíra; Miklisová, Dana

    2012-08-01

    Concentrations of six indicator PCB congeners (IUPAC nos. 28, 52, 101, 138, 153, and 180) were measured in several organs and adipose tissue of a freshwater predatory fishes (European perch, northern pike, pike perch, wels catfish) as well as in nonpredators (common carp, freshwater bream, goldfish, white bream) and in acanthocephalan Acanthocephalus lucii from the water reservoir Zemplínska šírava (Eastern Slovakia), which is considered to be one of the most PCB-contaminated places in Europe. Concentration of PCBs was determined by capillary gas chromatography in samples from May to September 2009. The two-way main-effect ANOVA confirmed that feeding habits of fish (P kidney, brain, and adipose tissue of their host. About 20 times lower amount of PCBs was detected in the liver and almost 3 times in muscles of infected perch. Data on PCB accumulation in perch infected with acanthocephalans demonstrated a decline of PCB values in all organs as well as in adipose tissue compared to noninfected fish. About 20 times lower amount of PCBs was detected in the liver and almost 3 times in muscles of infected perch. Present results could indicate that some parasitic organisms may influence positively their hosts in PCB-contaminated environment.

  13. Description, host range and distribution of a new Macrodiplosis species (Diptera: Cecidomyiidae) that induces leaf-margin fold galls on deciduous Quercus (Fagaceae) with comparative notes on Palaearctic congeners.

    Science.gov (United States)

    Kim, Wanggyu; Yukawa, Junichi; Harris, Keith M; Minami, Tsuneo; Matsuo, Kazunori; Skrzypczyńska, Małgorzata

    2014-06-20

    A gall midge that induces upwardly folded leaf-margin galls on Quercus serrata, Q. mongolica and Q. dentata (Fagaceae) in Japan and South Korea is described as Macrodiplosis selenis sp. n. (Diptera: Cecidomyiidae). M. selenis is distinguished from Palaearctic congeners by a combination of morphological characters. Genetic differences supported the result of morphological comparison and indicated that M. selenis is closely related to the European M. roboris, whose gall is similar to that of M. selenis.

  14. Exposure to the three structurally different PCB congeners (PCB 118, 153, and 126) results in decreased protein expression and altered steroidogenesis in the human adrenocortical carcinoma cell line H295R.

    Science.gov (United States)

    Tremoen, Nina Hårdnes; Fowler, Paul A; Ropstad, Erik; Verhaegen, Steven; Krogenæs, Anette

    2014-01-01

    Polychlorinated biphenyls (PCB), synthetic, persistent organic pollutants (POP), are detected ubiquitously, in water, soil, air, and sediments, as well as in animals and humans. PCB are associated with range of adverse health effects, such as interference with the immune system and nervous system, reproductive abnormalities, fetotoxicity, carcinogenicity, and endocrine disruption. Our objective was to determine the effects of three structurally different PCB congeners, PCB118, PCB 126, and PCB 153, each at two concentrations, on the steroidogenic capacity and proteome of human adrenocortical carcinoma cell line cultures (H295R) . After 48 h of exposure, cell viability was monitored and estradiol, testosterone, cortisol and progesterone secretion measured to quantify steroidogenic capacity of the cells. Two-dimensional (2D) gel-based proteomics was used to screen for proteome alterations in H295R cells in response to the PCB. Exposure to PCB 118 increased estradiol and cortisol secretion, while exposure to PCB 153 elevated estradiol secretion. PCB 126 was the most potent congener, increasing estradiol, cortisol, and progesterone secretion in exposed H295R cells. Seventy-three of the 711 spots analyzed showed a significant difference in normalized spot volumes between controls (vehicle only) and at least one exposure group. Fourteen of these protein spots were identified by liquid chromatography with mass spectroscopy (LC-MS/MS). Exposure to three PCB congeners with different chemical structure perturbed steroidogenesis and protein expression in the H295R in vitro model. This study represents an initial analysis of the effects on proteins and hormones in the H295R cell model, and additional studies are required in order to obtain a more complete understanding of the pathways disturbed by PCB congeners in H295R cells. Overall, alterations in protein regulation and steroid hormone synthesis suggest that exposure to PCB disturbs several cellular processes, including

  15. Reprint of: Long-range atmospheric transport of PAHs, PCBs and PBDEs to the central and eastern Mediterranean and changes of PCB and PBDE congener patterns in summer 2010

    Science.gov (United States)

    Mulder, Marie D.; Heil, Angelika; Kukučka, Petr; Kuta, Jan; Přibylová, Petra; Prokeš, Roman; Lammel, Gerhard

    2015-11-01

    The central and eastern Mediterranean is a receptor area for persistent organic pollutants (POPs) emitted in western, central and eastern Europe, particularly during summer. Atmospheric concentrations of PCBs, DDXs, PBDEs, penta- and hexachlorobenzene were measured during a ship-borne survey in the summer of 2010. The concentration of PCBs (sum of 7 congeners) was 3.61 (2.08-7.72) pg m-3, of which 6.7% was associated with the particulate phase. The mean concentration of DDT isomers and their metabolites, DDE and DDD, was 2.60 (0.46-7.60) pg m-3 (particulate mass fraction θ = 0.097), of penta- and hexachlorobenzene 0.22 (PBDEs (sum of 8 congeners) 7.31 (2.80-19.89) pg m-3. The air masses studied had been transported mostly across central Europe, some crossing western Europe. The observed changes of PCB congener patterns along transport routes are in agreement with the perception that the reaction with the OH radical is dominating PCB atmospheric lifetime, and indicate an overestimation of the second order gas-phase reaction rate coefficient of PCB153 with OH by structure-activity relationship.

  16. Insulin resistance, steatohepatitis, and hepatocellular carcinoma in a new congenic strain of Fatty Liver Shionogi (FLS) mice with the Lep(ob) gene.

    Science.gov (United States)

    Soga, Masahiko; Hashimoto, Setsuko; Kishimoto, Yoshio; Hirasawa, Tsutomu; Makino, Susumu; Inagaki, Shuichiro

    2010-01-01

    In order to examine the influence of obesity on metabolic disorder and liver pathogenesis of the Fatty Liver Shionogi (FLS) mouse, which develops hereditary fatty liver and spontaneous liver tumors, we established a new congenic strain named FLS-Lep(ob). The Lep(ob) gene of the C57BL/6JWakShi (B6)-Lep(ob)/Lep(ob) mouse was transferred into the genome of the FLS mouse, by backcross mating. FLS-Lep(ob)/Lep(ob) mice were maintained by intercrossing between Lep(ob)-heterozygous littermates. The FLS-Lep(ob)/Lep(ob) mice of both sexes developed remarkable hyperphagia, obesity and type 2 diabetes mellitus. At 12 weeks of age, glucosuria was detected in all male and female FLS-Lep(ob)/Lep(ob) mice. Biochemical examination demonstrated that the FLS-Lep(ob)/Lep(ob) mice have severe hyperlipidemia and hyperinsulinemia. The livers of FLS-Lep(ob)/Lep(ob) mice showed microvesicular steatosis and deposition of large lipid droplets in hepatocytes throughout the lobules. The steatohepatitis-like lesions including the multifocal mononuclear cell infiltration and clusters of foamy cells were observed earlier in FLS-Lep(ob)/ Lep(ob) mice than in FLS mice. B6-Lep(ob)/Lep(ob) mice did not show hepatic inflammatory change. Furthermore, FLS-Lep(ob)/Lep(ob) mice developed multiple hepatic tumors including hepatocellular adenomas and carcinomas following steatohepatitis. In conclusion, the FLS-Lep(ob)/Lep(ob) mice developed steatohepatitis and hepatic tumors following hepatic steatosis. The FLS-Lep(ob)/Lep(ob) mouse with obesity and type 2 diabetes mellitus might be a useful animal model for human non-alcoholic steatohepatitis (NASH).

  17. Congenic mice provide in vivo evidence for a genetic locus that modulates intrinsic transforming growth factor β1-mediated signaling and bone acquisition.

    Science.gov (United States)

    Mukherjee, Aditi; Larson, Emily A; Carlos, Amy S; Belknap, John K; Rotwein, Peter; Klein, Robert F

    2012-06-01

    Osteoporosis, the most common skeletal disorder, is characterized by low bone mineral density (BMD) and an increased risk of fragility fractures. BMD is the best clinical predictor of future osteoporotic fracture risk, but is a complex trait controlled by multiple environmental and genetic determinants with individually modest effects. Quantitative trait locus (QTL) mapping is a powerful method for identifying chromosomal regions encompassing genes involved in shaping complex phenotypes, such as BMD. Here we have applied QTL analysis to male and female genetically-heterogeneous F(2) mice derived from a cross between C57BL/6 and DBA/2 strains, and have identified 11 loci contributing to femoral BMD. Further analysis of a QTL on mouse chromosome 7 following the generation of reciprocal congenic strains has allowed us to determine that the high BMD trait, which tracks with the DBA/2 chromosome and exerts equivalent effects on male and female mice, is manifested by enhanced osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro and by increased growth of metatarsal bones in short-term primary culture. An insertion/deletion DNA polymorphism in Ltbp4 exon 12 that causes the in-frame removal of 12 codons in the DBA/2-derived gene maps within 0.6 Mb of the marker most tightly linked to the QTL. LTBP4, one of four paralogous mouse proteins that modify the bioavailability of the transforming growth factor β (TGF-β) family of growth factors, is expressed in differentiating MSC-derived osteoblasts and in long bones, and reduced responsiveness to TGF-β1 is observed in MSCs of mice homozygous for the DBA/2 chromosome 7. Taken together, our results identify a potential genetic and biochemical relationship between decreased TGF-β1-mediated signaling and enhanced femoral BMD that may be regulated by a variant LTBP4 molecule. Copyright © 2012 American Society for Bone and Mineral Research.

  18. Variable immune cell frequencies in peripheral blood of LEW.1AR1-iddm rats over time compared to other congenic LEW strains

    Science.gov (United States)

    Arndt, T; Jörns, A; Hedrich, H-J; Lenzen, S; Wedekind, D

    2014-01-01

    The LEW.1AR1-iddm rat is an animal model of human type 1 diabetes (T1D), which arose through a spontaneous mutation within the major histocompatibility complex (MHC)-congenic background strain LEW.1AR1. The LEW.1AR1-iddm rat is characterized by two phenotypes: diabetes development with a diabetes incidence of 60% and a variable T cell frequency in peripheral blood. In this study the immune cell repertoire of LEW.1AR1-iddm rats was analysed over time from days 30 to 90 of life and compared to the background strain LEW.1AR1 and the LEW rat strain as well as the LEW.1WR1 rat strain. The LEW.1AR1-iddm rats are characterized by a high variability of CD3+, CD4+ and CD8+ T cell frequencies in peripheral blood over time, and the frequency is unique for each animal. The variability within the frequencies resulted in changes of the CD4+ : CD8+ T cell ratio. The other three rat strains studied were characterized by a stable but nevertheless strain-specific T cell frequency resulting in a specific CD4+ : CD8+ T cell ratio. The frequency of natural killer (NK) cells and B cells in LEW.1AR1-iddm rats was increased, with a higher variability compared to the other strains. Only monocytes showed no differences in frequency and variability between all strains studied. These variabilities of immune cell frequencies in the LEW.1AR1-iddm rats might lead to imbalances between autoreactive and regulatory T cells in peripheral blood as a prerequisite for diabetes development. PMID:24628466

  19. Large-scale introduction of the Indo-Pacific damselfish Abudefduf vaigiensis into Hawai'i promotes genetic swamping of the endemic congener A. abdominalis.

    Science.gov (United States)

    Coleman, Richard R; Gaither, Michelle R; Kimokeo, Bethany; Stanton, Frank G; Bowen, Brian W; Toonen, Robert J

    2014-11-01

    Hybridization in the ocean was once considered rare, a process prohibited by the rapid evolution of intrinsic reproductive barriers in a high-dispersal medium. However, recent genetic surveys have prompted a reappraisal of marine hybridization as an important demographic and evolutionary process. The Hawaiian Archipelago offers an unusual case history in this arena, due to the recent arrival of the widely distributed Indo-Pacific sergeant (Abudefduf vaigiensis), which is hybridizing with the endemic congener, A. abdominalis. Surveys of mtDNA and three nuclear loci across Hawai'i (N = 396, Abudefduf abdominalis and N = 314, A. vaigiensis) reveal that hybridization is significantly higher in the human-perturbed southeast archipelago (19.8%), tapering off to 5.9% in the pristine northwest archipelago. While densities of the two species varied throughout Hawai'i, hybridization was highest in regions with similar species densities, contradicting the generalization that the rarity of one species promotes interspecific mating. Our finding of later generation hybrids throughout the archipelago invokes the possibility of genetic swamping of the endemic species. Exaptation, an adaptation with unintended consequences, may explain these findings: the endemic species has transient yellow coloration during reproduction, whereas the introduced species has yellow coloration continuously as adults, in effect a permanent signal of reproductive receptivity. Haplotype diversity is higher in Hawaiian A. vaigiensis than in our samples from the native range, indicating large-scale colonization almost certainly facilitated by the historically recent surge of marine debris. In this chain of events, marine debris promotes colonization, exaptation promotes hybridization, and introgression invokes the possible collapse of an endemic species.

  20. Chemically Induced Oncogenesis in the Peripheral Nervous System Is Suppressed in Congenic BDIX.BDIV-Mss1 and -Mss7 Rats

    Directory of Open Access Journals (Sweden)

    Bernd Koelsch

    2016-01-01

    Full Text Available Human malignant peripheral nerve sheath tumors (MPNSTs are highly aggressive soft-tissue sarcomas with a poor prognosis that arise either in the context of neurofibromatosis 1 or sporadically. Inbred BDIX and BDIV rat strains highly susceptible and resistant, respectively, to the development of ethylnitrosourea-induced MPNST enable us to identify, by using methods not applicable in humans, variant alleles involved in the pathways underlying individual MPNST risk. On the basis of a genome-wide association analysis using reciprocal intercrosses of BDIX and BDIV, BDIV alleles of two loci on chromosome 10, Mss1 and Mss7, were predicted to lower the risk of MPNST, the latter locus with a female bias. In this study we confirm the two nonoverlapping loci by exposing two congenic strains, BDIX.BDIV-Mss1 (Mss1 and BDIX.BDIV-Mss7 (Mss7, each carrying a BDIV genomic segment spanning the respective locus, to ethylnitrosourea. Compared with BDIX rats, the rate of MPNST is reduced 6.2-fold and 2.0-fold for Mss1 and Mss7 rats of both sexes, respectively. Although a moderate gain of survival time (30−50 days is seen in Mss1 rats of both sexes and Mss7 males, Mss7 females survive 134 days longer than BDIX females. BDIV alleles at Mss7 obviously cause a markedly increased intrastrain sex difference regarding survival time in Mss7 compared with BDIX rats. Fine mapping will lead to the identification of allelic variants modulating rat MPNST risk and subsequently to their human counterparts. This is of particular relevance, because so far neither gene nor anonymous sequence variants have been identified that influence the risk of human sporadic Schwann cell malignancy.

  1. Congener Profiles and Source-Wise Phase Partitioning Analysis of PCDDs/Fs and PCBs in Gyeonggi-Do Ambient Air, South Korea

    Directory of Open Access Journals (Sweden)

    Jongwon Heo

    2014-10-01

    Full Text Available The atmospheric concentrations and gas–particle partitioning of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs and polychlorinated biphenyls (PCBs were investigated at two sites (Suwon and Ansan in Gyeonggi-do, a heavily industrialized area of Korea, during the year 2010. The sum level (Σ17 of PCDDs/Fs and dioxin-like PCBs (dl-PCBs in the ambient air at Suwon and Ansan ranged from 0.04 to 0.30 pg-TEQ·m−3 (geometric mean: 0.09 pg-TEQ·m−3 and 0.17 to 0.63 pg-TEQ·m−3 (geometric mean: 0.36 pg-TEQ·m−3, respectively. Moreover, the geometric mean concentrations of Σ180 PCBs at Suwon and Ansan were 233.6 pg·m−3 and 274.2 pg·m−3, respectively, and di-chlorinated biphenyls and tri-chlorinated biphenyls were the predominant homologs. Among the PCB congeners, 3,3'-dichlorobiphenyl (PCB-11 was the dominant species at both sites during all sampling periods, comprising up to 15.1% of Σ180 PCBs at Ansan and 24.6% at Suwon. We evaluated their gas-to-particle equilibriums by conducting regression between the particle–gas partition coefficient Kp (m3·ug−1 and the corresponding subcooled liquid vapor pressure (PL°. The slope (m values for log–log plots of Kp vs. PL° were steeper in industrial areas owing to local source proximity. Moreover, owing to enhanced emissions from combustion-related sources at low temperatures, PCDD/Fs exhibited the largest deviation from the regression line of the particle–gas partition coefficient. Incinerators were found to be the primary emission source of atmospheric PCDDs/Fs, whereas re-evaporation from pre-existing environmental loads (e.g., storage areas or spilled soil and water bodies was the dominant source for PCBs.

  2. Critical review of soil contamination by polybrominated diphenyl ethers (PBDEs) and novel brominated flame retardants (NBFRs); concentrations, sources and congener profiles.

    Science.gov (United States)

    McGrath, Thomas J; Ball, Andrew S; Clarke, Bradley O

    2017-11-01

    Polybrominated diphenyl ethers (PBDEs) have been used in a broad array of polymeric materials such as plastics, foams, resins and adhesives to inhibit the spread of fires since the 1970s. The widespread environmental contamination and well documented toxic effects of PBDEs have led to bans and voluntary withdrawals in many jurisdictions. Replacement novel brominated flame retardants (NBFRs) have, however, exhibited many of the same toxic characteristics as PBDEs and appear to share similar environmental fate. This paper presents a critical review of the scientific literature regarding PBDE and NBFR contamination of surface soils internationally, with the secondary objective of identifying probable pollution sources. An evaluation of NBFR distribution in soil was also conducted to assess the suitability of the newer compounds as replacements for PBDEs, with respect to their land contamination potential. Principle production of PBDEs and NBFRs and their consequent use in secondary polymer manufacture appear to be processes with strong potential to contaminate surrounding soils. Evidence suggests that PBDEs and NBFRs are also released from flame retarded products during disposal via landfill, dumping, incineration and recycling. While the land application of sewage sludge represents another major pathway of soil contamination it is not considered in this review as it is extensively covered elsewhere. Both PBDEs and NBFRs were commonly detected at background locations including Antarctica and northern polar regions. PBDE congener profiles in soil were broadly representative of the major constituents in Penta-, Octa- and Deca-BDE commercial mixtures and related to predicted market place demand. BDE-209 dominated soil profiles, followed by BDE-99 and BDE-47. Although further research is required to gain baseline data on NBFRs in soil, the current state of scientific literature suggests that NBFRs pose a similar risk to land contamination as PBDEs. Copyright © 2017

  3. Persistent organochlorine pollutants and toxaphene congener profiles in bottlenose dolphins (Tursiops truncatus) frequenting the Turtle/Brunswick River Estuary (TBRE) in coastal Georgia, USA.

    Science.gov (United States)

    Pulster, Erin L; Smalling, Kelly L; Zolman, Eric; Schwacke, Lori; Maruya, Keith A

    2009-07-01

    Although the Turtle/Brunswick River Estuary (TBRE) in coastal Georgia (USA) is severely contaminated by persistent organochlorine pollutants (POPs), little information regarding POPs in higher-trophic-level biota in this system is available. In the present study, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs; including DDTs, chlordanes, and mirex), and chlorinated monoterpenes (toxaphene) were measured using gas chromatography with electron-capture detection and gas chromatography with electron-capture negative ion mass spectrometry (GC-ECNI-MS) in blubber of free-ranging and stranded bottlenose dolphins (Tursiops truncatus). Mean total PCBs (78.6 +/- 32.4 microg/g lipid) and toxaphene (11.7 +/- 9.3 microg/g lipid) were significantly higher in dolphins sampled in the TBRE than in dolphins stranded near Savannah (GA, USA) 80 to 100 km to the north. Levels of OCPs were several-fold lower than levels of PCBs; moreover, PCBs comprised 81 and 67% of the total POP burden in TBRE and non-TBRE dolphins, respectively. Analyses with GC-ECNI-MS revealed that 2,2,5-endo,6-exo,8,8,9,10-octachlorobornane (P-42a), a major component in technical toxaphene and a major residue congener in local estuarine fish species, was the most abundant chlorobornane in both sets of blubber samples. Mean total POP concentrations (sum of PCBs, OCPs, and toxaphene) approached 100 microg/g lipid for the TBRE animals, well above published total PCB thresholds at which immunosuppresion and/or reproductive anomalies are thought to occur. These results indicate extended utilization of the highly contaminated TBRE as habitat for a group of coastal estuarine dolphins, and they further suggest that these animals may be at risk because of elevated POP concentrations.

  4. Low-Chlorinated Non-Dioxin-like Polychlorinated Biphenyls Present in Blood and Breast Milk Induce Higher Levels of Reactive Oxygen Species in Neutrophil Granulocytes than High-Chlorinated Congeners.

    Science.gov (United States)

    Berntsen, Hanne Friis; Fonnum, Frode; Walaas, Sven Ivar; Bogen, Inger Lise

    2016-12-01

    Despite their ban several decades ago, polychlorinated biphenyls (PCBs) still pose a health threat to human beings due to their persistent and accumulative nature and continued presence in the environment. Non-dioxin-like (NDL)-PCBs have earlier been found to have effects on the immune system, including human neutrophil granulocytes. The aim of this study was to investigate the differences between ortho-chlorinated NDL-PCBs with a low or high degree of chlorination in their capability to induce the production of reactive oxygen species (ROS) in human neutrophil granulocytes in vitro. We used some of the congeners occurring at the highest levels in blood, breast milk and food: PCB 52 representing the low-chlorinated congeners and PCB 180 the high-chlorinated congeners. In addition, the extensively studied PCB 153 was included as a reference compound. ROS production was assessed with the luminol-amplified chemiluminescence and DCF fluorescence assays. The involvement of intracellular signalling mechanisms was investigated using different pharmacological substances. At high concentrations (10-20 μM), PCB 52 induced more ROS than PCB 153 and PCB 180. The role of extracellular signal-regulated kinase (ERK) 1/2 and/or ERK 5 signalling in PCB-induced ROS production was implicated through the reduction in ROS in the presence of the specific inhibitor U0126, whereas reduced ROS production after the use of SB203580 and SP600125 indicated the involvement of the p38 mitogen-activated protein kinase (MAPK) and c-Jun amino-terminal kinase (JNK) pathways, respectively. In addition, the calcineurin inhibitor FK-506, the intracellular calcium chelator BAPTA-AM and the antioxidant vitamin E reduced the levels of ROS. The intracellular signalling mechanisms involved in ROS production in human neutrophil granulocytes appeared to be similar for PCB 52, PCB 153 and PCB 180. Based on the results from the present and previous studies, we conclude that for abundant ortho-chlorinated PCBs

  5. 含氟及非共平面结构可溶性聚酰亚胺的合成与性能研究%Study on Synthesis and Properties of Soluble Polyimides Containing Fluorine and Non-coplanar Structure

    Institute of Scientific and Technical Information of China (English)

    梅媚; 彭大伟; 裴响林; 刘婵娟; 黄孝华; 韦春

    2015-01-01

    采用4-氟苯甲醛和2-异丙基苯胺合成新型二胺单体双(4-氨基-3-异丙基苯基)-4-氟苯基)甲烷(APFM),通过“一步法”缩聚反应得到一类新型含氟及非共平面结构的可溶性聚酰亚胺,并对其结构与性能进行表征和分析。结果表明:该聚酰亚胺呈现出良好的溶解性能、高耐热性、高光学透明性、低介电常数。%A novel diamine monomer bis(4-amino-3-isopropylphenyl)-4-fluorophenylmethane was synthe-sized by 4-fluorobenzaldehyde and 2-isopropylaniline. Then a soluble polyimide(PI) containing fluorine and non-coplanar structure was obtained by one-step polycondensation reaction, and its structure and prop-erties were characterized. The results show that the PI has good solubility, high thermal stability, high op-tical transparency, and low dielectric constant.

  6. Contamination status and possibility of toxic effects of co-planar polychlorinated biphenyls, polycyclic aromatic hydrocarbons, and dichlorodiphenyltrichloroethane in large japanese field mouse (Apodemus speciosus) collected from Hokkaido and Aomori.

    Science.gov (United States)

    Mizukawa, Hazuki; Ikenaka, Yoshinori; Nakayama, Shouta M M; Sakamoto, Kentaro Q; Fujita, Shoichi; Ishizuka, Mayumi

    2014-08-01

    Contamination levels of coplanar polychlorinated biphenyls (Co-PCBs), polycyclic aromatic hydrocarbons (PAHs), and dichlorodiphenyltrichloroethane (DDTs) were measured in the entire body of the large Japanese field mouse (Apodemus speciosus) collected from Hokkaido (Ishikari and Rankoshi) and Aomori prefecture (Takko) in Japan. Higher concentrations of PCBs including Co-PCBs, were observed in the mice collected from Ishikari than those from Rankoshi. The concentration of PAHs in the soil from Ishikari was also higher than that in the other sampling sites. The findings suggest that Ishikari is the most polluted area, probably because of human activities, depending on the population distribution. However, the observed contaminant levels were extremely lower compared to those in previous studies. The ratio of testis weight to body weight (TW/BW) was the lowest in the mice collected from Ishikari, which is the area contaminated with PAHs and p,p'-dichlorodiphenyldichloroethylene (DDE). However, the serum testosterone levels of mice from the Ishikari area were higher than those from the non-contaminated other areas although no significant differences. Previous studies have shown that a low-level exposure to dioxin related compounds (DRCs) disturbances in sexual function, resulting in the production of testosterone. This study showed that POPs exposure is one of the possibility of the high testosterone concentration in the mice of the Ishikari area in addition to a cause of biological and environmental factors such as habitat density, age, temperatures and/or food riches.

  7. 利用推广的Hartmann方法光滑拼接两个异面直线%Employing Improved Hartmann Method to Smoothly Blending two Non-coplanar Straight Lines

    Institute of Scientific and Technical Information of China (English)

    刘斯语; 白根柱

    2015-01-01

    In this paper, we are blending of two straight lines in different planes by using the curve with the form of parameters. Discussing the smoothly blending between two non-coplanar straight lines by the improved Hartmann method. We generalize the Hartmann function on the plane to the space curve. And we have deduced the conditions of smoothly blending the straight lines in different planes among this space curve. On the basis of this . We obtain the parameter equation of this transition curve and present a specific example.%利用参数形式的曲线光滑拼接两条异面直线,讨论了对于给定的两条异面直线可用推广的Hart-mann函数光滑拼接的问题,将平面Hartmann函数曲线推广到空间曲线上,推导出该空间曲线光滑拼接异面直线的拼接条件,在此基础上,得到了过渡曲线的参数方程,并给出了具体实例。

  8. Effect of nutrient availability on the uptake of PCB congener 2,2',6,6'-tetrachlorobiphenyl by a diatom (Stephanodiscus minutulus) and transfer to a zooplankton (Daphnia pulicaria).

    Science.gov (United States)

    Lynn, Scott G; Price, David J; Birge, Wesley J; Kilham, Susan S

    2007-06-01

    The objective of this study was to examine the importance of nutrient status of a diatom (Stephanodiscus minutulus) to the uptake of PCB congener #54 (2,2',6,6'-tetrachlorobiphenyl) and the subsequent transfer of PCB to a pelagic grazing zooplankton (Daphnia pulicaria). The algae, which were grown under different nutrient treatments, were then fed to a zooplankton to examine the subsequent food chain transfer of PCB. Algal cultures were grown for at least 2 weeks in a steady state condition in (1) non-limiting, (2) low-Si, (3) low-N or (4) low-P media. Steady state algal cultures were dosed with 0.2 microg L(-1) PCB and were sampled for PCB uptake after 24h. D. pulicaria were allowed to graze on these same cultures for 48 h before being analyzed for PCB body burdens. Low-Si (68% or 0.135 microg L(-1) of PCB) and low-P cultures (62%) had significantly higher percentage uptake of total PCB than the non-limiting (55%) or low-N (52%) treatments. When these values were divided by biochemical or elemental parameters, PCB per lipids (microg microg(-1)) had one of the lowest coefficients of variation (CV) across the four treatments, indicating their importance in PCB uptake. When equal biovolumes of the four different treatment cultures were fed to zooplankton, both the low-N (13.9 ng PCB mg wet weight(-1)) and the low-P (9.6 ng PCB mg wet weight(-1)) grazing D. pulicaria had significantly higher PCB per wet weight than the low-Si (5.6 ng PCB mg wet weight(-1)) and non-limited (2.6 ng PCB mg wet weight(-1)) grazing D. pulicaria. There were no significant differences between algal nutrient treatments in PCB per wet weight of zooplankton grazing on clean algal food in PCB contaminated media. This study indicates that uptake of PCB by phytoplankton can be significantly altered by nutrient availability which subsequently affects transfer to zooplankton, potentially through such responses as grazing rate and lipid assimilation.

  9. 共面波导型行波电光调制器的设计和数值分析%DESIGN AND NUMERICAL ANALYSIS OF COPLANAR WAVEGUIDE TYPE TRAVELLING-WAVE ELECTRO-OPTIC MODULATOR

    Institute of Scientific and Technical Information of China (English)

    黄晹; 杨森祖

    2000-01-01

    提出一种新颖的、速度匹配的共面波导型电光调制器设计。采用窄地电极、加盖屏蔽层的设计获得了较好效果。针对复杂边界形状和多层介质交界面,在计算设计参数时作了改进,如引入张量计算,使用吸收边界条件(ABC),采用动态场域分割及带状矩阵存储等,显著提高了有限元方法(FEM)解准静电磁场问题的计算效率和精度。并对前人的设计进行了计算,结果与之相近,表明数值计算的合理性。利用此计算方法,对1.55μm的波长和LiNbO衬底进行了参数优化,实现了光波与微波传播速度的匹配,同时给出关于有效折射率和特征阻抗的详细图示。%Optical fiber communication has become one of the most important means of telecommumication in the modem society. More and more backbone optical fiber networks have come into use. In the future, it will be beyond doubt that main information systems are based on full-optic communication. So more attention is paid to high-speed electro-optic modulators because of its great significance in optic fiber communication. In this paper a novel coplanar waveguide type travelling-wave electro-optic modulator is devised. Narrow ground electrode and shieldplane help it to obtain good performance. Electro-optic modulators' complex boundary shape and multilayer dielectric lead us to design a kind of numerical calculation technique which employs Finite Element Method (FEM) to solve the two-dimensional quasi-static transverse distribution of electric field problems. A simple comparison batween FEM and other computing methods is given. Several improvements are used to make great progress in efficiency and precision of numerical analysis. For example, we utilize tensor εto replace the original scalar in Laplaee equation so that the celculation can be applied to aeolotropic crystal; we adopt a sort of new boundary condition to simulate infinite electric field-Absorbing Boundary

  10. Coplanar Oligo(p-phenylenedisilenylene)s as Si═Si Analogues of Oligo(p-phenylenevinylene)s: Evidence for Extended π-Conjugation through the Carbon and Silicon π-Frameworks.

    Science.gov (United States)

    Li, Liangchun; Matsuo, Tsukasa; Hashizume, Daisuke; Fueno, Hiroyuki; Tanaka, Kazuyoshi; Tamao, Kohei

    2015-12-01

    A series of oligo(p-phenylenedisilenylene)s (Si-OPVs 1-4), silicon analogues of oligo(p-phenylenevinylene)s, up to the tetramer have been synthesized and isolated by the introduction of a newly developed protecting group [(HexO)MEind] for improving their solubility. The experimental and theoretical studies of the Si-OPVs 1-4 demonstrate the fully extended π-conjugation of the Si-OPV main chains. Single crystal X-ray analyses of the monomer 1 and the dimer 2 revealed the highly coplanar Si-OPV backbones facilitating the effective extension of the π-conjugation, which has further been validated by the significant increases in the absorption maxima from 465 nm for the monomer 1 to 610 nm for the tetramer 4. The absorption maxima exhibit an excellent fit to Meier's equation, leading to the estimation of an effective conjugation length (ECL) of 9 repeat units (nECL = 9) and the absorption maximum of 635 nm for the infinite chain (λ∞ = 635 nm). In sharp contrast to other nonemissive disilenes, the Si-OPVs 2-4 show an intense fluorescence from 613 to 668 nm at room temperature with the quantum yields up to 0.48. All the data presented here provide the first evidence for the efficient extended π-conjugation between the Si═Si double bonds and the carbon π-electron systems over the entire Si-OPV skeleton. This study reveals the possibility for developing the conjugated disilene π-systems, in which the Si═Si double bonds would be promising building blocks, significantly optimizing the intrinsic photophysical and electrochemical properties of the carbon-based π-conjugated materials.

  11. 两平面二次曲线不变量的定义、几何解释及计算方法%Geometric Interpretation and Algorithm of the Invariants of A pair of Coplanar Conics

    Institute of Scientific and Technical Information of China (English)

    张政武

    2012-01-01

    从实际计算的角度出发,研究了两平面二次曲线射影不变量,并对其进行了相应的几何解释,提出了相应的计算方法。首先从两二次型的不变量推导出两平面二次曲线的射影不变量,接着利用两平面二次曲线的共自极三角形给出了两平面二次曲线不变量的几何解释及计算方法。在此基础上,通过举例分析和实验验证,证明文中所给公式的正确性。%The object recognition based on the invariants is the most active research area in the computer vision. The conventional studies about invariants are that these invariants are derived for planar objects using points and lines from images. Nowadays, more and more interest comes from 3 D reconstruction based on the invariants of conics. The projective invariants of a pair of coplanar conics are studied from the perspective of computational proces- ses and the geometrically interpreted is proposed in this paper. The projective invariants of a pair of eoplanar conics are first defined from invariants of a pair of quadratic forms. Then the invariants are geometrically interpreted by using the common self-polar triangle of the two conics, and the algorithm is proposed in this paper. The result of example shows that this formula in this paper is correct on the basis of present studies.

  12. 基于共面波导微带线的光探测器高频电参量提取%High Frequency Electrical Parameter Extraction for Photodetectors Based on Coplanar Waveguide Microstrips

    Institute of Scientific and Technical Information of China (English)

    徐光辉; 柴广跃; 黄长统; 何黎明; 徐健; 廖世东; 冯丹华

    2013-01-01

    For no on-wafer measurement of photodetectors (PDs),a simple and effective method to determine high frequency electrical parameters of the equivalent circuit model is presented.Firstly,a coplanar waveguide (CPW) microstrip matched with the microwave probe is designed,and the measured output reflection coefficient shows good agreement with the theoretical design.The chip is mounted on the CPW microstrip and the output reflection coefficient of the PD testfixture is measured.The equivalent circuit model including the PD,the bondwire and the CPW elements is simulated.By fitting the measured output reflection coefficient of the test-fixture,high frequency electrical parameters of the PD are extracted.%针对不能在片测量的光探测器芯片,本文提出了一个简单而有效的实验方案来提取其等效电路模型的高频电参量.首先设计了和微波探针匹配的共面波导微带线,测量其输出反射系数,测试结果与理论设计符合很好;然后将芯片装载到微带线上,测量包含光探测器的整个测试结构的输出反射系数.仿真中涉及光探测器测试结构的等效电路模型,包含光探测器、键合金丝和共面波导微带线等因素.通过拟合已测的整个测试结构的输出反射系数,提取了光探测器的高频电参量.

  13. Acute Toxicities of the Saxitoxin Congeners Gonyautoxin 5, Gonyautoxin 6, Decarbamoyl Gonyautoxin 2&3, Decarbamoyl Neosaxitoxin, C-1&2 and C-3&4 to Mice by Various Routes of Administration

    Directory of Open Access Journals (Sweden)

    Andrew I. Selwood

    2017-02-01

    Full Text Available Paralytic shellfish poisoning results from consumption of seafood naturally contaminated by saxitoxin and its congeners, the paralytic shellfish toxins (PSTs. The levels of such toxins are regulated internationally, and maximum permitted concentrations in seafood have been established in many countries. A mouse bioassay is an approved method for estimating the levels of PSTs in seafood, but this is now being superseded in many countries by instrumental methods of analysis. Such analyses provide data on the levels of many PSTs in seafood, but for risk assessment, knowledge of the relative toxicities of the congeners is required. These are expressed as “Toxicity Equivalence Factors” (TEFs. At present, TEFs are largely based on relative specific activities following intraperitoneal injection in a mouse bioassay rather than on acute toxicity determinations. A more relevant parameter for comparison would be median lethal doses via oral administration, since this is the route through which humans are exposed to PSTs. In the present study, the median lethal doses of gonyautoxin 5, gonyautoxin 6, decarbamoyl neosaxitoxin and of equilibrium mixtures of decarbamoyl gonyautoxins 2&3, C1&2 and C3&4 by oral administration to mice have been determined and compared with toxicities via intraperitoneal injection. The results indicate that the TEFs of several of these substances require revision in order to more accurately reflect the risk these toxins present to human health.

  14. Acute Toxicities of the Saxitoxin Congeners Gonyautoxin 5, Gonyautoxin 6, Decarbamoyl Gonyautoxin 2&3, Decarbamoyl Neosaxitoxin, C-1&2 and C-3&4 to Mice by Various Routes of Administration.

    Science.gov (United States)

    Selwood, Andrew I; Waugh, Craig; Harwood, David T; Rhodes, Lesley L; Reeve, John; Sim, Jim; Munday, Rex

    2017-02-21

    Paralytic shellfish poisoning results from consumption of seafood naturally contaminated by saxitoxin and its congeners, the paralytic shellfish toxins (PSTs). The levels of such toxins are regulated internationally, and maximum permitted concentrations in seafood have been established in many countries. A mouse bioassay is an approved method for estimating the levels of PSTs in seafood, but this is now being superseded in many countries by instrumental methods of analysis. Such analyses provide data on the levels of many PSTs in seafood, but for risk assessment, knowledge of the relative toxicities of the congeners is required. These are expressed as "Toxicity Equivalence Factors" (TEFs). At present, TEFs are largely based on relative specific activities following intraperitoneal injection in a mouse bioassay rather than on acute toxicity determinations. A more relevant parameter for comparison would be median lethal doses via oral administration, since this is the route through which humans are exposed to PSTs. In the present study, the median lethal doses of gonyautoxin 5, gonyautoxin 6, decarbamoyl neosaxitoxin and of equilibrium mixtures of decarbamoyl gonyautoxins 2&3, C1&2 and C3&4 by oral administration to mice have been determined and compared with toxicities via intraperitoneal injection. The results indicate that the TEFs of several of these substances require revision in order to more accurately reflect the risk these toxins present to human health.

  15. Generation of congenic mouse strains by introducing the virus-resistant genes, Mx1 and Oas1b, of feral mouse-derived inbred strain MSM/Ms into the common strain C57BL/6J.

    Science.gov (United States)

    Moritoh, Kanako; Yamauchi, Hideto; Asano, Atsushi; Yoshii, Kentaro; Kariwa, Hiroaki; Takashima, Ikuo; Isoda, Norikazu; Sakoda, Yoshihiro; Kida, Hiroshi; Sasaki, Nobuya; Agui, Takashi

    2009-08-01

    Mx1 (Myxovirus resistance protein) and Oaslb (Oligoadenylate synthetase-1), induced by type 1 interferon (IFN), play a role in early antiviral innate immunity by inhibiting the replication of viruses. In mice, Mx1 and Oas1b confer resistance to the infection of orthomyxoviruses including influenza viruses and flaviviruses including West Nile viruses, respectively. Laboratory mice have been used to study the mechanisms of the pathogenesis of these virus infections; however, it is possible that they are not a suitable model system to study these viruses, since most of the inbred laboratory mouse strains lack both genes. It has been reported that feral mouse-derived inbred strains show resistance to the infection of these viruses due to the presence of intact both genes. In this study, we generated congenic strains in which the Mx or Oas locus of the MSM/Ms (MSM) mouce was introduced to the most widely used mouse strain, C57BL/6J (B6). B6.MSM-Mx mice showed resistance to the infection of influenza virus but not of West Nile virus. On the other hand, B6.MSM-Oas mice showed resistance to the infection of West Nile virus but not of influenza virus. Our results indicate that Mx1 and Oaslb show highly antiviral specificity in mice possessing the same genetic background. Therefore, these congenic mice are useful for not only infection study but also investigation of host defense mechanism to these viruses.

  16. Studies on Predation of Phrynocaria congener and Scymnussp. on Cornegenapsyllasinica%2种天敌瓢虫对龙眼角颊木虱的捕食作用研究

    Institute of Scientific and Technical Information of China (English)

    邱良妙; 占志雄

    2015-01-01

    In order to study the control effects of natural enemies on pests in Longan orchards, the predation of Phrynocaria congener and Scymnus sp. on the Cornegenapsylla sinica were studied in laboratory. The results showed that the functional responses of the two predatory ladybirds on C. sinica were of Holling’s II. The capitia of C. sinica preyed by the two predatory ladybirds were both increased with the increase of prey density. With the increasing of age of C. sinica, the searching rate of the predatory ladybirds decreased, and its handling time became longer. Comparison of the two predatory ladybirds, the P. congener performed the higher searching rate and the shorter handling time. Given a certain number of the same age of C. sinica, the feeding capitia of P. congener was larger than Scymnus sp. did.%为研究天敌对龙眼害虫的控制作用,以龙眼角颊木虱为研究对象,在实验室研究红星盘瓢虫和小毛瓢虫对龙眼角颊木虱的捕食功能反应。结果表明,2种天敌瓢虫对龙眼角颊木虱的捕食功能反应模型均属HollingⅡ型,对猎物的捕食量(Na)都是随着猎物密度(N)的增加而增加,而对猎物的捕食量(Na)和寻找效率(a)均随着龙眼角颊木虱虫龄的增加而降低,处理时间(Th)延长;红星盘瓢虫的寻找效率大于小毛瓢虫,处置时间则更短,在同一虫态既定猎物密度下,红星盘瓢虫的捕食量显著大于小毛瓢虫。

  17. Orbit optimization of supplying satellite of non-coplanar constellation based on formation flight mode%基于伴飞模式的异面星座补给轨道优化

    Institute of Scientific and Technical Information of China (English)

    肖东东; 徐波; 高有涛; 杨大林

    2012-01-01

    伴飞模式的卫星燃料补给设想突破了传统的基于交会对接技术的单一燃料补给模式,给未来空间在轨燃料补给提供了新的思路.为了解决基于伴飞模式的异面星座燃料补给的规划问题,本文首先找出停泊轨道到工作星轨道的能量最优的转移轨道;其次通过对补给星机动过程中所需速度增量的分析,认为可以通过求解TSP问题来获得最优的补给顺序;然后针对伴飞补给过程中燃料消耗函数多参数、单目标的特点,结合理想火箭动力学方程,利用带约束的遗传算法,进一步对补给轨道进行了优化求解;最后,通过具体的数值仿真,验证了此优化的可行性与有效性.%The tentative plan of refueling satellites based on formation flying breaks through the traditional only refueling method based on rendezvous and docking, and provides a new thinking for the future on-orbit refueling. To solve the problem of the plan of refueling non-coplanar based on formation flying, this work gives priority to finding a energy optimized transfer orbit between the parking orbit and the working orbit. Secondly, based on the analysis of the necessary velocity increment in the supplier's maneuver, we consider that the optimal refuel order can be determined by solving TSP. Then, taking account of that the consumption function has multi-parameter and single target and combining the ideal rocket dynamics equation, the further optimal solution of the supplier's orbit is given in terms of the constrained genetic algorithm. At last, the feasibility and effectiveness are verified by numerical simulation.

  18. A survey of dietary intake of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and dioxin-like coplanar polychlorinated biphenyls from food during 2000-2002 in Osaka City, Japan.

    Science.gov (United States)

    Nakatani, Tadashi; Yamamoto, Atsushi; Ogaki, Sumiko

    2011-04-01

    Studies of the dietary intake of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like coplanar polychlorinated biphenyls (dioxin-like PCBs), collectively referred as dioxins, were conducted using the total diet study (TDS) method with food purchased in Osaka City, Japan during 2000-2002. The daily intake of dioxin-TEQ (toxic equivalent) from food per adult person was estimated respectively as 104.24 pg TEQ/person/day in 2000, 72.73 pg TEQ/person/day in 2001, and 87.28 pg TEQ/person/day in 2002, corresponding to 2.08, 1.45, and 1.74 pg TEQ/kg body weight (bw)/day for an adult weighing 50 kg. The highest contribution ratio to the total intake of dioxin-TEQ was from fish and shellfish (group 10) in each year, accounting for 77-92%. The next highest contributor was meat and eggs (groups 11-A and 11-B). An annual decrease of the intake of dioxin-TEQ was not observed clearly. Otherwise, the dietary intake of non-2,3,7,8-substituted PCDDs/PCDFs were estimated together. The intake of 1,3,6,8-TeCDD came mostly from intake of fish and shellfish (group 10), green vegetable (group 7), and the other vegetables, including mushrooms and seaweed (group 8). In addition, the intake of 1,3,6,8-TeCDF, which reportedly antagonizes 2,3,7,8-TeCDD-mediated aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD) induction activities, was an insufficient amount to suppress 2,3,7,8-TeCDD-mediated activities. Furthermore, we discussed different TEQ compositions of PCDDs/PCDFs to dioxin-like PCBs from food intake and in human samples and inferred that the difference was caused by low bioaccumulation properties of 3,3',4,4',5-PeCB (PCB 126). © Springer Science+Business Media, LLC 2010

  19. Increased litter size and super-ovulation rate in congenic C57BL mice carrying a polymorphic fragment of NFR/N origin at the Fecq4 locus of chromosome 9

    DEFF Research Database (Denmark)

    Liljander, Maria; Andersson, Åsa Inga Maria; Holmdahl, Rikard

    2009-01-01

    By analysing N2 mice from a cross between the inbred C57BL strain B10.Q and the NMRI-related NFR/N strain, we recently identified a quantitative trait locus (QTL) influencing litter size. This locus is now denoted Fecq4, and it is present on the murine chromosome 9. In the present paper, we....... In addition, embryos containing the Fecq4 fragment were easy to cultivate in vitro, resulting in a higher yield of embryos reaching the blastocyst stage. We propose that B10.Q.NFR/N-Fecq4 congenic mice may be used to improve breeding or super-ovulation rate in different types of genetically modified mice (on...

  20. Differences in the action of lower and higher chlorinated polychlorinated naphthalene (PCN) congeners on estrogen dependent breast cancer cell line viability and apoptosis, and its correlation with Ahr and CYP1A1 expression.

    Science.gov (United States)

    Gregoraszczuk, Ewa L; Barć, Justyna; Falandysz, Jerzy

    2016-07-29

    There are data showing that exposition to PCNs mixture increased incidence of gastrointestinal and respiratory neoplasms, but data regarding incidence of hormone-dependent cancer so far not shown. The objective was to determine if exposure to single lower and higher chlorinated PCN congeners is associated with altered proliferation and apoptosis of estrogen dependent breast cancer cells, and whether such effects are related to induction of AhR and CYP1A1 protein expression. MCF-7 cells were exposed to PCN 34, 39, 42, 46, 48, 52, 53, 54, 66, 67, 70, 71, 73 and 74 at concentrations of 100-10,000pg/ml. We evaluated the action of these PCN congeners on cell proliferation, DNA fragmentation and caspase-8,-9 activity. AhR and CYP1A1 protein expression and CYP1A1 activity was evaluated at a concentration of 1000pg/ml. An opposite action of tri- to tetraCNs than of penta-to heptaCNs on cell proliferation and apoptosis was evident. Tetra PCNs increased cell proliferation, but had no effect on DNA fragmentation nor caspase activity. Fast induction of CYP1A1 protein expression under the influence of lower chlorinated PCNs suggests faster metabolism and a possible stimulatory action of locally formed metabolites on cell proliferation. None of the higher chlorinated PCNs affected cell proliferation but all higher chlorinated PCNs increased caspase-8 activity, and hexa PCNs also increased caspase-9 activity. The rapid activation of the Ah receptor and CYP1A1 protein expression by higher chlorinated PCNs point to their toxicity; however, it is not sufficient for potential carcinogenicity. Action of lower chlorinated naphthalenes metabolites should be explored.

  1. Novel analytical approach for brominated flame retardants based on the use of gas chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry with emphasis in highly brominated congeners.

    Science.gov (United States)

    Portolés, Tania; Sales, Carlos; Gómara, Belén; Sancho, Juan Vicente; Beltrán, Joaquim; Herrero, Laura; González, María José; Hernández, Félix

    2015-10-06

    The analysis of brominated flame retardants (BFRs) commonly relies on the use of gas chromatography coupled to mass spectrometry (GC-MS) operating in electron ionization (EI) and electron capture negative ionization (ECNI) modes using quadrupole, triple quadrupole, ion trap, and magnetic sector analyzers. However, these brominated contaminants are examples of compounds for which a soft and robust ionization technique might be favorable since they show high fragmentation in EI and low specificity in ECNI. In addition, the low limits of quantification (0.01 ng/g) required by European Commission Recommendation 2014/118/EU on the monitoring of traces of BFRs in food put stress on the use of highly sensitive techniques/methods. In this work, a new approach for the extremely sensitive determination of BFRs taking profit of the potential of atmospheric pressure chemical ionization (APCI) combined with GC and triple quadrupole (QqQ) mass analyzer is proposed. The objective was to explore the potential of this approach for the BFRs determination in samples at pg/g levels, taking marine samples and a cream sample as a model. Ionization and fragmentation behavior of 14 PBDEs (congeners 28, 47, 66, 85, 99, 100, 153, 154, 183, 184, 191, 196, 197, and 209) and two novel BFRs, decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), in the GC-APCI-MS system has been investigated. The formation of highly abundant (quasi) molecular ion was the main advantage observed in relation to EI. Thus, a notable improvement in sensitivity and specificity was observed when using it as precursor ion in tandem MS. The improved detectability (LODs < 10 fg) achieved when using APCI compared to EI has been demonstrated, which is especially relevant for highly brominated congeners. Analysis of samples from an intercomparison exercise and samples from the marine field showed the potential of this approach for the reliable identification and quantification at very low

  2. Determination of polychlorinated biphenyls in marine fish obtained from tsunami-stricken areas of Japan.

    Science.gov (United States)

    Uekusa, Yoshinori; Takatsuki, Satoshi; Tsutsumi, Tomoaki; Akiyama, Hiroshi; Matsuda, Rieko; Teshima, Reiko; Hachisuka, Akiko; Watanabe, Takahiro

    2017-01-01

    We determined the polychlorinated biphenyl (PCB) congeners in 101 marine fish obtained from tsunami-stricken areas following the Great East Japan Earthquake in 2011. In particular, to determine the degree of PCB contamination in the fish, we investigated the concentration of total PCB (∑PCB) and the proportions of 209 individual PCB congeners by high-resolution gas chromatography/high-resolution mass spectrometry. The ∑PCB concentration was 1.7-33 ng/g in fat greenling (n = 29), 0.44-25 ng/g in flounder (n = 36), and 1.6-86 ng/g in mackerel (n = 36), all values being much lower than the provisional regulatory limit in Japan. In the congener analysis, tetra-, penta-, hexa-, and hepta-chlorinated PCB congeners dominated in all samples (comprising over 86% of the ∑PCB). The proportions of the chlorinated PCB congeners were similar to the contamination patterns derived from Kanechlor in the environment, implying that the marine fish were not contaminated with fresh PCBs.

  3. 脊椎共面排列矫形技术治疗特发性脊柱侧凸的初步疗效%Preliminary outcome of three-dimensional correction for idiopathic scoliosis by vertebral coplanar alignment

    Institute of Scientific and Technical Information of China (English)

    修鹏; 宋跃明; 刘浩; 刘立岷; 龚全; 李涛; 曾建成

    2011-01-01

    Objective:To evaluate the preliminary outcome of vertebral coplanar alignment (VCA) for the management of idiopathic scoliosis (IS).Method:20 patients with IS undergoing one-stage posterior pedicle screw fixation,VCA correction and allograft fusion were included in this study.There were 15females and 5 males with the mean age of 15.3 years (range,11 to 21 years ).According to Lenke classification system,there were 14 type 1 and 6 type 2.The mean Cobb angle of the main curve was 67.5°(range,50° to 86°) and the mean thoracic kyphosis was 25.7°(range,5° to 55°).After correction,the Cobb angle of the main curve and thoracic kyphosis were evaluated.The rib hump(RH),apical vertebral body rib ratio(AVB-R),apical rib spread difference(ARSD) and rotational angle to sacrum(RAsac) were measured to assess the correction of rotational deformity.Result:All patients underwent this surgical protocol successfully without major complications.The average operation time was 164min (range,115 to 196min),and the mean blood loss was 680ml (range,400 to 800ml).The mean residual Cobb angle of main curve was 20.6°(range,12° to 27°) and the corrective rate was 70.1% with the corrective rate of RH,AVB-R,ARSD and RAsac of 56.3%,29.8%,74.3% and 54.1% respectively. The mean postoperative kyphosis was 21.8°(range,17° to 27°) and the thoracic kyphosis recovered to normal in all patients with no hypokyphosis noted. All patients were followed up for an average of 9 months (range,3 to 12 months).No decompensation and loss of correction was noted. Conclusion:VCA correc tion can manage coronal misalignment, recover thoracic alignment and rotational deformity of IS effectively.%目的:评估脊椎共面排列(vertebral coplanar alignment,VCA)矫形技术治疗特发性脊柱侧凸(idiopathic scoliosis,IS)的初步疗效.方法:2010年1月~9月采用VCA技术治疗IS患者20例,男5例,女15例,年龄11~21岁,平均15.3岁;Lenke 1型14例,2型6例;术前主弯Cobb角50°~86

  4. Multiple mechanisms of PCB neurotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, D.O.; Stoner, C.T.; Lawrence, D.A. [Univ. of New York, Albany, NY (United States)] [and others

    1996-12-31

    Polychlorinated biphenyls (PCBs) have been implicated in cancer, but many of the symptoms in humans exposed to PCBs are related to the nervous system and behavior. We demonstrated three different direct mechanisms whereby PCBs are neurotoxic in rats. By using flow cytometry, we demonstrated that the orthosubstituted PCB congener 2,4,4{prime}, but neither TCDD nor the coplanar PCB congener 3,4,5,3{prime},4{prime}, causes rapid death of cerebellar granule cells. The ortho-substituted congener 2,4,4{prime} reduced long-term potentiation, an indicator of cognitive potential, in hippocampal brain slices, but a similar effect was observed for the coplanar congener 3,4,3{prime},4{prime}, indicating that this effect may be caused by both ortho- and coplanar congeners by mechanisms presumably not mediated via the Ah receptor. It was previously shown that some ortho-substituted PCB congeners cause a reduction in levels of the neurotransmitter dopamine, and we present in vitro and in vivo evidence that this is due to reduction of synthesis of dopamine via inhibition of the enzyme tyrosine hydroxylase. Thus, PCBs have a variety of mechanisms of primary neurotoxicity, and neurotoxicity is a characteristic of ortho-substituted, non-dioxin-like congeners as well as some coplanar congeners. The relative contribution of each of these mechanisms to the loss of cognitive function in humans exposed to PCBs remains to be determined. 42 refs., 3 figs., 1 tab.

  5. Contaminant Residues in Demersal Fish, Invertebrates, and Deployed Mussels in Selected Areas of the Puget Sound, WA

    Science.gov (United States)

    2007-03-29

    additional ENVVEST congeners mainly consisted of very low concentrations of coplanar dioxin - like congeners that did not contribute very much to the...mussel study help to address this issue because the impact of all environmental stressors on growth and survival, biomarkers of sublethal stress such as

  6. DFT and Position of Cl Substitution (PCS) Methods Studies on n-Octanol/water Partition Coefficients (lgKow) and Aqueous Solubility (-lgSw) of All PCDD Congeners

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Optimized calculations of 75 PCDDs and their parent DD were carded out at the B3LYP/6-31G* level by density functional theory (DFT) method. The structural parameters were obtained and significant correlation between the Cl substitution position and some structural parameters was found. Consequently, the number of Cl substitution positions was taken as theoretical descriptors to establish two novel QSPR models for predicting lgKow and -lgSw of all PCDD congeners. The two models achieved in this work contain two variables (Nα and Nβ), of which r = 0.9312, 0.9965 and SD = 0.27, 0.12 respectively, and t values are all large. The variation inflation factors (VIF) of variables in the two models herein are both less than 5.0, suggesting high accuracy of the lgKow and -lgSw predicting models, and the results of cross-validation test also show that the two models exhibit optimum stability and good predictive power. By comparison, the correlation and predictive ability of the present work are more advantageous than those obtained using semi-empirical AM1 and GC-RI methods.

  7. Toxaphene analysis in Great Lakes fish: a comparison of GC-EI/MS/MS and GC-ECNI-MS, individual congener standard and technical mixture for quantification of toxaphene.

    Science.gov (United States)

    Xia, Xiaoyan; Crimmins, Bernard S; Hopke, Philip K; Pagano, James J; Milligan, Michael S; Holsen, Thomas M

    2009-09-01

    Toxaphene is considered to be a problematic organochlorine pollutant because of its bioaccumulation potential and persistence in aquatic environments. In this study, whole lake trout and walleye composites were used to evaluate two analytical techniques for total toxaphene and selected congener analysis. The efficacy of using gas chromatography electron ionization tandem mass spectrometry (GC-EI/MS/MS) and electron capture negative ionization mass spectrometry (GC-ECNI-MS) were compared. Although the sensitivity using GC-ECNI-MS was approximately five times greater than GC-EI/MS/MS, the latter provided more consistent inter-Parlar relative response factors (RRF). When using technical calibration mixtures, these results suggest a more accurate total toxaphene measurement was obtained using the GC-EI/MS/MS method. Total toxaphene concentrations in lake trout composites from both methods were highly correlated (R(2) = 0.985) with the MS/MS concentrations approximately half of those determined by ECNI, suggesting systematic high bias in toxaphene concentrations when measured using GC-ECNI.

  8. 直剪作用下不共面断续节理岩桥破断试验与数值研究%Experimental and Numerical Analysis on Rupture of Rock Bridge with Non-Coplanar Intermittent Joints Under Direct Shear

    Institute of Scientific and Technical Information of China (English)

    赵延林; 彭青阳; 万文; 王卫军; 赵伏军

    2014-01-01

    By using servo control shear loading system ,specimens with non-coplanar rock-like intermittent joints were tested by the way of forward and reverse direct shear ,rupture mechanism and shearing law for rock bridge with non-coplanar intermittent joints were studied under direct shear .The experimental studies showed that five apparent stages are presented in the process of rock bridge rupture under direct shear , which are linear elastic stage ,initiation and extension of crack ,fracture and transfixion of rock bridge , climbing and occlusion of shear plane and residual friction .Rock bridge presented profile fracture plane under forward direct shear .While under reverse direct shear ,band form fracture plane is showed which penetrated along with the direction of forward shear ,and the shear strength of initiation and peak shear strength under reverse direct shear are bigger than that under forward shear .Crack angle ,normal stress and lap proportion among adjacent joint are the main factors that influence the initiation strength and peak shear strength . The FLAC3D simulation for the process of non-coplanar intermittent joints rock bridge rupture and formation of shear rupture surface under forward and reverse direct shear was conducted .The results of numerical simulation agreed well with those of experiment . The simulation results revealed tension crack failure of non-coplanar intermittent joints rock bridge and shear yielding mechanism of fracture plane .%在伺服控制剪切加载系统下对不共面类岩石断续节理试件进行正向、反向直剪试验,研究直剪下不共面断续节理的岩桥破断机理和剪切规律,试验研究发现,直剪作用下不共面断续节理岩桥破坏过程具有明显的阶段性,经历线弹性阶段、裂纹起裂扩展阶段、岩桥断裂贯通阶段、剪切面爬坡咬合阶段和残余摩擦阶段5个阶段,正向剪切下岩桥呈齿形破断面,反向剪切作用下岩桥产生沿直剪

  9. Non-local spin injection effects in coplanar La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}/ La{sub 0.7}Sr{sub 0.3}MnO{sub 3} tri-layer

    Energy Technology Data Exchange (ETDEWEB)

    Joseph, D. Paul [Department of Physics, National Institute of Technology, Warangal, Telangana-506 004 (India); Lin, J. G., E-mail: jglin@ntu.edu.tw [Center for Condensed Matter Sciences, National Taiwan University, Taipei 10617, Taiwan (China)

    2015-06-24

    Non-local electrical properties of pulsed laser deposited La{sub 0.7}Sr{sub 0.3}MnO{sub 3}/Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}/La{sub 0.7}Sr{sub 0.3}MnO{sub 3} (L-B-L) coplanar tri-layer is investigated under different wiring configurations. Long range super-current of Bi-2212 penetrating into LSMO is dependent on geometry of spin injection. From qualitative analysis of structural, magnetic and electrical data, long range super-current is suggested to pass through domain walls and/or grain boundaries of LSMO.

  10. Assays of polychlorinated biphenyl congeners and co-contaminated heavy metals in the transgenic Arabidopsis plants carrying the recombinant guinea pig aryl hydrocarbon receptor-mediated β-glucuronidase reporter gene expression system.

    Science.gov (United States)

    Shimazu, Sayuri; Ohta, Masaya; Ohkawa, Hideo; Ashida, Hitoshi

    2012-01-01

    The transgenic Arabidopsis plant XgD2V11-6 carrying the recombinant guinea pig (g) aryl hydrocarbon receptor (AhR)-mediated β-glucuronidase (GUS) reporter gene expression system was examined for assay of polychlorinated biphenyl (PCB) congeners and co-contaminated heavy metals. When the transgenic Arabidopsis plants were treated with PCB126 (toxic equivalency factor; TEF: 0.1) and PCB169 (TEF: 0.03), the GUS activity of the whole plants was increased significantly. After treatment with PCB80 (TEF: 0), the GUS activity was nearly the same level as that treated with 0.1% dimethylsulfoxide (DMSO) as a vehicle control. After exposure to a 1:1 mixture of PCB126 and PCB169, the GUS activity was increased additively. However, after exposure to a mixture of PCB126 and PCB80, the GUS activity was lower than that of the treatment with PCB126 alone. Thus, PCB80 seemed to be an antagonist towards AhR. When the transgenic plants were treated with each of the heavy metals Fe, Cu, Zn, Cd and Pb together with PCB126, Cd and Pb increased the PCB126-induced GUS activity. On the other hand, Fe, Cu and Zn did not affect the PCB126-induced GUS activity. In the presence of the biosurfactant mannosylerythritol lipid-B (MEL-B) and the carrier protein bovine serum albumin (BSA), the PCB126-induced GUS activity was increased, but the Cd-assisted PCB126-induced GUS activity was not affected. Thus, MEL-B and BSA seemed to increase uptake and transport of PCB126, respectively.

  11. Polychlorinated biphenyls in settled dust from informal electronic waste recycling workshops and nearby highways in urban centers and suburban industrial roadsides of Chennai city, India: Levels, congener profiles and exposure assessment.

    Science.gov (United States)

    Chakraborty, Paromita; Prithiviraj, Balasubramanian; Selvaraj, Sakthivel; Kumar, Bhupander

    2016-12-15

    Polychlorinated biphenyls (PCBs) were quantified in settled dust collected from informal electronic waste (e-waste) recycling workshops and nearby highways in the urban centers and roadside dust from the suburban industrial belt of Chennai city in India. Further dust samples were subjected to a high resolution field emission scanning electron microscope equipped with an energy dispersive X-ray spectrometer (FESEM/EDX) to characterize the shape, size and elemental composition of the dust particles. Geomean of total PCB concentration followed the following order: informal e-waste metal recovery workshops (53ngg(-1))>e-waste dismantling sites (3.6ngg(-1))>nearby highways (1.7ngg(-1))>suburban industrial roadsides (1.6ngg(-1)). In e-waste workshops, tetra, penta and hexa-PCB homologs contributed two third of Σ26PCB concentration. Informal e-waste recycling workshops contributed more than 80% concentration of all the PCB congeners loaded in the first principal component. Predominance of dioxin like PCBs, PCB-l14, -118 and -126 in the e-waste metal recovery sites were presumably due to combustion and pyrolytic processes performed during recycling of electrical components. According to the morphology and elemental composition, settled dust from e-waste workshops were irregular particles heavily embedded with toxic metals and industrial roadside dust were distinct angular particles. FESEM revealed that average particle size (in Ferret diameter) increased in the following order: e-waste recycling workshops (0.5μm)

  12. Estimation of Freely-Dissolved Concentrations of Polychlorinated Biphenyls, 2,3,7,8-Substituted Congeners and Homologs of Polychlorinated dibenzo-p-dioxins and Dibenzofurans in Water for Development of Total Maximum Daily Loadings for the Bluestone River Watershed, Virginia and West Virginia

    Science.gov (United States)

    Gale, Robert W.

    2007-01-01

    The Commonwealth of Virginia Department of Environmental Quality, working closely with the State of West Virginia Department of Environmental Protection and the U.S. Environmental Protection Agency is undertaking a polychlorinated biphenyl source assessment study for the Bluestone River watershed. The study area extends from the Bluefield area of Virginia and West Virginia, targets the Bluestone River and tributaries suspected of contributing to polychlorinated biphenyl, polychlorinated dibenzo-p-dioxin and dibenzofuran contamination, and includes sites near confluences of Big Branch, Brush Fork, and Beaver Pond Creek. The objectives of this study were to gather information about the concentrations, patterns, and distribution of these contaminants at specific study sites to expand current knowledge about polychlorinated biphenyl impacts and to identify potential new sources of contamination. Semipermeable membrane devices were used to integratively accumulate the dissolved fraction of the contaminants at each site. Performance reference compounds were added prior to deployment and used to determine site-specific sampling rates, enabling estimations of time-weighted average water concentrations during the deployed period. Minimum estimated concentrations of polychlorinated biphenyl congeners in water were about 1 picogram per liter per congener, and total concentrations at study sites ranged from 130 to 18,000 picograms per liter. The lowest concentration was 130 picograms per liter, about threefold greater than total hypothetical concentrations from background levels in field blanks. Polychlorinated biphenyl concentrations in water fell into three groups of sites: low (130-350 picogram per liter); medium (640-3,500 picogram per liter; and high (11,000-18,000 picogram per liter). Concentrations at the high sites, Beacon Cave and Beaverpond Branch at the Resurgence, were about four- to sixfold higher than concentrations estimated for the medium group of sites

  13. Congenıtal cutis laxa

    Directory of Open Access Journals (Sweden)

    Fuat Gürkan

    2003-03-01

    Full Text Available A case report is presenting about a rarely appering disease cutis laxa named also as Dermatomegaly and Generalise Elastosis. As it appears congenitally also seems with the accompaniment of infection, inflamation, collagen tissue diseases, hypersensitivity reactions and treatment with D- penicillamine.

  14. 宫颈癌术后三维适形放疗和共面等分设野调强放疗计划的对比分析%Dosimetric study of postoperative 3-dimensional conformal radiotherapy and coplanar decile intensity-modulated radiotherapy for cervical cancer

    Institute of Scientific and Technical Information of China (English)

    蒋军; 张利文; 廖珊; 黄荣

    2012-01-01

    目的 探讨宫颈癌术后三维适形放射治疗(3D-CRT)和共面等分设野调强放射治疗(IMRT)计划靶区及其周围危及器官受照剂量的差异.方法 随机选择10例宫颈癌术后患者,进行CT扫描、靶区和危及器官的勾画,处方剂量50 Gy.分别进行3D-CRT和共面等分设野IMRT计划设计,计算靶区剂量均匀度指数(HI)、适形度指数(CI)、最大受照剂量、最小受照剂量、平均受照剂量和危及器官照射体积等并对结果进行比较分析.结果 5F-IMRT、7F-IMRT和9F-IMRT在靶区适形度方面明显优于3D-CRT;在危及器官(膀胱V30 、V40 、V50,小肠V50和直肠V30、V40、V50)保护方面,5F-IMRT、7F-IMRT和9F-IMRT明显优于3D-CRT,P<0.05.而各IMRT计划之间差异无统计学意义,P>0.05.结论 宫颈癌术后辅助放疗共面等分IMRT计划无论在靶区适形度还是正常组织保护方面均优于3D-CRT,同时也证实7野或9野IMRT未必较5野获益更多.5野与7、9野的IMRT相比、在治疗时间及费用方面有独特的优势,值得在临床上推广.%Objective To compare the difference of the dose distribution in clinical target volume and organ at risk (OAR) between coplanar decile field intensity-modulated radiotherapy (IMRT) and conventional three-dimensional conformal radiotherapy (3D-CRT) for postoperative radiotherapy of cervical cancer. Methods Ten postoperative patients with cervical cancer were selected randomly to undergo CT scan and planning target volume (PTV) and OAR contouring. 3D-CRT and coplanar decile IMRT planning was performed for each patient with a prescribed dose of 50 Gy. The homogeneity index (HI), conformity index (CI), maximum dose, minimum dose, mean dose of PTV, and irradiated volume of OARs were calculated and the results were compared. Results 5-field IMRT, 7-field IMRT and 9-field IMRT plans had a significant better conformity index (CI) of PTV compared with 3D-CRT (P0.05). Conclusion Coplanar decile IMRT plans is superior

  15. Developmental expression of insulin-like growth factor II receptor (IGF-IIR) in congenic mouse embryonic lungs: correlation between IGF-IIR mRNA and protein levels and heterochronic lung development.

    Science.gov (United States)

    Melnick, M; Chen, H; Rich, K A; Jaskoll, T

    1996-06-01

    Embryonic lung maturation in the H-2 congenic pair, B10.A and B10, proceeds at different rates. The dependence of this heterochronic development on maternal haplotype suggests the involvement of a parentally imprinted gene. Since B10.A (H-2a) and B10 (H-2b) mice are genetically identical except for a 3-18 cM region of chromosome 17 that includes the H-2 complex, we sought a promising candidate gene(s) involved in regulating the rate of lung development from genes encoded in this region. The best candidate is the gene encoding the type II insulin-like growth factor receptor (IGF-IIR), whose ligand is the growth factor IGF-II. Only the maternal copy of this gene is expressed in postimplantation embryos. This receptor does not appear to transduce mitogenic signals; instead, IGF-IIR appears to regulate the levels of its ligand available to the growth-promoting type I IGF receptor (IGF-IR). Using in situ hybridization and indirect immunofluorescence, we demonstrate that IGF-IIR mRNA and protein are localized throughout the pulmonary mesenchyme, as well as in branching epithelia of the pseudoglandular and canalicular stages. We also examined the levels of IGF-IIR mRNA and protein expression by RNase protection assay and ligand blotting during the embryonic period of lung development in B10.A and B10 mice, and found that there is a highly significant positive correlation of IGF-IIR levels with progressive development in both strains. Further, slower-developing B10.A lungs contain significantly higher levels of IGF-IIR mRNA and protein than the more rapidly developing B10 lungs. These results suggest that haplotype-dependent elevation of IGF-IIR levels reduces the available concentration of IGF-II, resulting in a decreased rate of morphogenesis in B10.A mice. Heterochronic lung maturation, then, appears consequent to variable extracellular levels of this important growth factor. These results may be of clinical importance to predicting susceptibility to Respiratory

  16. Maternal-infant transfer of polybrominated diphenyl ethers

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, T.; Fujimine, Y.; Watanabe, S. [Otsuka Pharmaceutical Co., Ltd., Tokushima (Japan); Nakamura, Y. [SRL Nishinihon, Fukuoka (Japan); Shimomura, H. [Shimomura OBGY Clinic, Fukuoka (Japan); Nagayama, J. [Kyushu Univ., Fukuoka (Japan)

    2004-09-15

    Polybrominated diphenyl ethers (PBDEs) are widely used brominated flame retardants (BFRs) in plastics of automobiles, textile industry, television, personal computer, electronic appliances etc. The amount of production world-wide has reached 40,000 tons in 1992. In 1992 world-wide production of PBDEs reached 40,000 tons raising serious concern over the dangers of environmental pollution by BFRs. The toxicity of PBDEs was reported to be an antagonist of thyroid-hormone (T4) and inhibition to aryl hydrocarbon (Ah) receptor. Since PBDEs are structurally similar to PCBs and therefore they work as an antagonist. Polychlorinated biphenyl (PCBs) demonstrate biological stability and high lipophilicity. As a result, PCBs used in the past and released into the environment, have been transmitted through the food chain and accumlated in the human body over time. In Japan, approximately 58,000 tons of PCBs were produced with the grade name of Kanechlor in between 1954 and 1971. In this study, all PCB congeners and 25 PBDE congeners (17, 25, 28, 30, 32, 33, 35, 37, 47, 49, 66, 71, 75, 77, 85, 99, 100, 116, 119, 126, 138, 153, 154, 155, 166) were analyzed by the method that combines high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The purpose of this study was to investigate whether congener-specific PCBs and PBDEs were transferred from pregnant women to their infants.

  17. 气相色谱-串联质谱法测定人参和黄芪中7种毒杀芬残留量%Determination of seven toxaphene congeners in Ginseng and Milkvetch Root by gas chromatographytandem mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    田绍琼; 毛秀红; 苗水; 郏征伟; 王柯; 季申

    2012-01-01

    A novel method for the determination of representative toxaphene congeners in traditional Chinese herbal medicines was developed. Ginseng and Milkvetch Root were selected as the samples and seven toxaphene congeners were selected as the monitoring objects. The samples were extracted by accelerated solvent extraction with cyclohexane-acetone (9:1, v/v), then cleaned-up by Florisil solid phase extraction with hexane as the eluent and the residues were detected by gas chromatography-electron ionization tandem mass spectrometry (GC-EI-MS/MS) in multiple reaction monitoring (MRM) mode. The performance was demonstrated by the analysis of Ginseng and Milkvetch Root samples spiked with toxaphene congeners at three concentration levels of 0. 005, 0. 01 and 0. 1 mg/kg. The recoveries ranged from 72.4% to 105% with the relative standard deviations (RSDs) of 0. 96% - 10. 4%. The limits of detection (LODs) were 0. 2 -1. 7 ji,g/kg. This method is sensitive and efficient in the aspect of extraction, and can be applied to monitor the residue of toxaphene congeners in Ginseng and Milkvetch Root.%建立了人参和黄芪中毒杀芬代表性单体残留量的检测方法.选择7种指示性毒杀芬单体为检测品种,样品用环己烷-丙酮(9∶1,v/v)加速溶剂萃取法提取,经弗罗里硅土固相萃取柱净化后,以气相色谱-电子轰击离子源串联质谱(GC-EI-MS/MS)在多反应监测(MRM)模式下进行测定.在人参和黄芪两种中药材样品基质,0.005、0.01和0.1 mg/kg 3个加标水平条件下,7种毒杀芬单体的回收率为72.4%~105%,相对标准偏差为0.96%~10.4%;方法的检出限(S/N=3)为0.2~1.7 μg/kg,均符合农药残留检测要求.该方法提取效果好,检测灵敏度高,适用于人参和黄芪中7种毒杀芬残留量的检测.

  18. 基于空间曲线啮合轮的同平面多轴输出微小减速器研究进展%Research of Coplanar Multiaxial Output Micro-reducer based on Space Curve Meshing Wheel

    Institute of Scientific and Technical Information of China (English)

    陈扬枝; 傅小燕

    2012-01-01

    Micro - reducer is a key area of micro mechanical system. Based on the space curve meshing wheel, coplanar multiaxial output micro - reducer is introduced. Series and parallel structure forms of the reducer are introduced , which are named the equilateral planarpolygon axial distributive micro - reducer and the parallel multiaxial output micro - reducer, the transmission type and structure characteristic are analyzed, an application example is enumerated. Finally, the main research directions for the new reducer in industrial application are summarized.%微小减速器是微小机械系统的重要组成部分,是目前重要研究领域之一.介绍了基于空间曲线啮合轮传动机构而设计的同平面多轴输出微小减速器,包括不同特点的两种结构形式,即基于正多边形轴分布的串联式多轴输出微小减速器和并联式多轴输出微小减速器,并例举了应用实例.最后,归纳了其工业化应用需研究的主要方向.

  19. Crystal Structure and π-π Stacking of a Coplanarμ-S Bridged 1,10-Phenanthroline Palladium(H) Dinuclear Complex%共平面的μ-S桥联(1,10-菲咯啉)钯(Ⅱ)双核配合物的晶体结构与π-π堆积

    Institute of Scientific and Technical Information of China (English)

    俞玫; 李一志; 王流芳; 黄海平; 于澍燕

    2006-01-01

    A novel μ-S-bridged di-palladium(Ⅱ) complex, {[(phen)Pd(μ-SPr)2Pd(phen)](NO3)2·2H2O} (1) was synthesized and characterized by the 1H NMR, element analysis and single crystal X-ray diffraction. It crystallizes in the monoclinic space group C2/c with unit cell parameters: a=2.165 1(3) nm, b=1.291 4(2) nm, c=2.716 2(3) nm, 3=111.987(3)° and V=7.041 8(16) nm3, Z=8, R=0.0544, wR=0.127 4. The X-ray crystal structure analysis revealed that two 1,10-phenanthroline palladium(Ⅱ) moieties were bridged by two n-propylmercapatan molecules in coplanar fashion with the dimensions of 1.55 nm × 0.88 nm. The plane-to-plane distance of the complex 1 is 0.33 nm, which reveals strong aromatic-aromatic π-π interaction. CCDC: 292998.

  20. First-order distorted wave Born approximation for single ionization of Ar by electron impact in a coplanar doubly symmetric geometry%共面双对称条件下电子碰撞Ar原子单电离的一阶扭曲波Born近似*

    Institute of Scientific and Technical Information of China (English)

    张立民; 贾昌春; 王琦; 陈长进

    2014-01-01

    在共面双对称几何条件下,利用一阶扭曲波Born近似计算了中低能电子碰撞Ar原子(3p壳层电子)单电离的三重微分截面,并与最近的实验数据做了比较。结果表明,对于Ar原子,当入射电子能量比电离阈高40 eV以上,随着入射能量的增加, binary和recoil碰撞机理逐渐占据支配地位;在近阈能量范围,上述碰撞机理不再处于支配地位,扭曲效应明显。要完备地描述中低能入射条件下Ar原子的电子碰撞电离过程,理论模型必须同时考虑多种散射机理。%The first-order distorted wave Born approximation (DWBA) has been performed for single ionization of Ar(3p) by electron impact in coplanar doubly symmetric geometry from near threshold to intermediate energies. Theoretical triple differential cross sections (TDCS) are compared with the latest experimental data. It is found that when the incident electron energies are 40 eV higher than the ionization threshold, for argon, the binary and recoil collision mechanism will dominat as the energies increase, but not in the near threshold energy regime, where the distortion effects are of great significance. In order to completely describe the electron impact ionization of argon, it is imperative that more scattering mechanisms should be considered in the theoretical models.

  1. 气相色谱-负化学电离质谱法测定沉积物和鱼肉中毒杀芬的8个同类物及其总含量%Analysis of toxaphene and its eight congeners in sediment and fish tissue by gas chromatography-negative ion mass spectrometry

    Institute of Scientific and Technical Information of China (English)

    劳文剑

    2013-01-01

    Toxaphene quantification incorporating gas chromatography/negative chemical ionization mass spectrometry (GC/NCI-MS) offers improved sensitivity and specificity.The U.S.Environmental Protection Agency (USEPA) recently released a GC/NCI-MS method (Method 8276) for the measurement of technical toxaphene and eight specific congeners (Hx-Sed,Hp-Sed,P26,P41,P40,P44,P50 and P62).However,there is still lack of a practical and complete analytical method including sample extraction,clean up,instrumental analysis,and data analysis.The goal of this work was to develop a ready-to-use method for the quantification of total toxaphene and the eight congeners.Sediment and salmon fish tissue were selected as sample matrices and extracted with methylene chloride using an accelerated solvent extraction system.The sample extracts were cleaned up with active copper powder or gel permeation chromatography,and finally silica/alumina combination column.Separation was performed on a DB-XLB column.GC/NCI-MS was operated under selected ion monitoring mode with an identical set of confirmation and quantitation ions for total toxaphene and the eight congeners.Oxygen reaction of polychlorinated biphenyls (PCB) was monitored by PCB204,an internal calibration standard,and the reaction level was kept below 1%.Average relative response factors were used in quantitation.Quantitation of total toxaphene employed the sum of all detectable (S/N ≥ 3) 6-Cl to 10-Cl homolog peak areas,while the individual congeners were quantified followed the standard procedures for single analytes.Multi-point calibration solutions ranged from 0.5 (5 for P62) to 500 μg/L for the individual congeners,and 50 to 500 μg/L for technical toxaphene,with the lowest calibration levels as lower limits of quantitation.Average congener recovery was (90.8 ± 17.4)% (n =10) in spiked sediment with relative standard deviations of 5.4%-12.8% (n =10),underscoring an excellently accurate and precise method.The method was

  2. Neutrality point of graphene with coplanar charged impurities.

    Science.gov (United States)

    Fogler, Michael M

    2009-12-04

    The ground state and the transport properties of graphene subject to the potential of in-plane charged impurities are studied. The screening of the impurity potential is shown to be nonlinear, producing a fractal structure of electron and hole puddles. Statistical properties of this density distribution as well as the charge compressibility of the system are calculated in the leading-log approximation. The conductivity depends logarithmically on alpha, the dimensionless strength of the Coulomb interaction. The theory is asymptotically exact when alpha is small, which is the case for graphene on a substrate with a high dielectric constant.

  3. Characterization of a multimode coplanar waveguide parametric amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Simoen, M., E-mail: simoen@chalmers.se; Krantz, P.; Bylander, Jonas; Shumeiko, V.; Delsing, P. [Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, Göteborg SE-412 96 (Sweden); Chang, C. W. S.; Wilson, C. M. [Institute for Quantum Computing and Department of Electrical and Computer Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Wustmann, W. [Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, Göteborg SE-412 96 (Sweden); Laboratory for Physical Sciences, College Park, Maryland 20740 (United States)

    2015-10-21

    We characterize a Josephson parametric amplifier based on a flux-tunable quarter-wavelength resonator. The fundamental resonance frequency is ∼1 GHz, but we use higher modes of the resonator for our measurements. An on-chip tuning line allows for magnetic flux pumping of the amplifier. We investigate and compare degenerate parametric amplification, involving a single mode, and nondegenerate parametric amplification, using a pair of modes. We show that we reach quantum-limited noise performance in both cases.

  4. Ultra wideband coplanar waveguide fed spiral antenna for humanitarian demining

    DEFF Research Database (Denmark)

    Thaysen, Jesper; Jakobsen, Kaj Bjarne; Appel-Hansen, Jørgen

    2000-01-01

    to 1 bandwidth with a return loss better than 10 dB from 0.4 to 3.8 GHz is presented. A wideband balun covering the frequency range of the antenna was developed. The constructed spiral antenna is very useful in a stepped frequency ground penetrating radar for humanitarian demining due to the very...

  5. Radiotherapy for Nasopharyngeal Carcinoma with Non-coplanar Hatano Conformal Radiation Dosimetry Advantages and Disadvantages of Contrast Due to%鼻咽癌放疗采用非共面多野适形照射所致剂量学优劣对比

    Institute of Scientific and Technical Information of China (English)

    明智

    2012-01-01

    Narrow wear after irradiation to avoid the spinal cord wear irradiation at the same time add photos line the wild, illuminated area and regional radiotherapy of the primary tumor to cure is prevention of the amount of shrink again; non-total face more than wild fitness-shaped plan design on the three-dimensional conformal-shaped surface of the neck joint wild basis plus according to the nose before the wild and cranial top wild, avoid the use of X-ray and electronic wire convergence irradiation, to the prevention of the amount of narrowing the scope of the primary tumor, plus the amount; intensity modulated plan designed to reverse treatment planning, to the target tissue dose and volume calculation precision by volume, superior to conventional radiotherapy target volume dose coverage and normal tissue protection by adjusting the target or normal tissue. Results: analysis of plan data, the poor uniformity of the target dose in the three-dimensional conformal plans for the parotid gland is unable to play a protective role; non-coplanar Hatano conformal plan target uniformity better than the former and better protection for the parotid some damage, but for the brain tissue and the visual system due to the incident path longer caused by the randomness of radiation injury and the probability of increase; IMRT dose uniformity and normal tissue of the target area by the amount of controllability are better than the first two persons. Conclusions: The three-dimensional conformal radiation therapy is widely used and easy to operate, but there is no dosimetric advantage of non-coplanar wild fitness-shaped irradiation technology has some defects, but the dosimetry is better than the three-dimensional conformal plan, intensity-modulated radiotherapy plans for dose-round the accuracy of control, to prove their absolute dominance used in radiotherapy for nasopharyngeal carcinoma.

  6. 全二维气相色谱-电子捕获检测器法分析土壤中毒杀芬同类物的残留%Comprehensive Two-dimensional Gas Chromatography with Micro-electron Capture Detector for Analysis of Toxaphene Congeners in Soil

    Institute of Scientific and Technical Information of China (English)

    张兵; 郑明辉; 刘国瑞; 李成; 高丽荣

    2012-01-01

    A comprehensive two dimensional gas chromatography coupled with micro-electron capture detector (GC×GC-μECD) method for the simultaneous analysis of 23 congeners of toxaphene in soil has been developed and validated. A DB-XLB column (20 m×0. 25 mm×0. 25 μm) was chosen as the column for the first dimension, and a BPX-50 column (2 m×0. 1 mm×0. 1 μm) was chosen as the column for the second dimension. The matrix-matched external standard calibration curves were used for quantitative analysis. The established method showed good linearity with correlation coefficients (r2) higher than 0. 99 in the concentration range of 1-200 μg/L. Limits of detection ranged from 0. 039 to 0. 482 μg/L for individual congeners. The relative standard deviations (RSD) of all 23 toxaphene congeners in matrix spiked samples were below 30% (n = 5), and recoveries ranged from 55% to 115%. For validation, the developed method was applied to the determination of toxaphene in a soil sample.%建立了全二维气相色谱-电子捕获检测器(GC× GC-μECD)检测土壤中毒杀芬同类物的分析方法.以非极性的DB- XLB(20 m×0.25 mm×0.25 μm)为第一色谱柱,中等极性的BPX-50(2 m×0.1 mm×0.1 μm)为第二色谱柱,对土壤中23种高关注毒杀芬同类物进行了分离鉴定,并采用基质曲线外标法进行定量分析.本方法在1~200,μg/L浓度范围内,毒杀芬同类物的线性相关系数(r2)均大于0.99,方法检出限(S/N=3)为0.039~0.482 μg/L,基质加标毒杀芬同类物的回收率为55%~115%,相对标准偏差(RSD)均小于30%(n=5).利用本方法对毒杀芬污染的土壤样品进行了测定,获得了较好的分离效果.

  7. Fusing Phthalocyanine and Porphyrin together:Unprecedented Co-planar Ring-Fused Diazaphthalocyaninato-porphyrin Dimers%一种新型的平面共轭的酞菁卟啉二联体的合成及光谱研究

    Institute of Scientific and Technical Information of China (English)

    王康; 齐冬冬; Mack John; 王海龙; 李文军; 边永忠; 小林长夫; 姜建壮

    2012-01-01

    An unprecedented ring-fused co-planar diazaphthalocyaninato-porphyrin dimer H4{[(DAPc(OC4H9)6][TClPP]}(where DAPc(OC4H9)6 is the dianion of 2,3,9,10,16,17-hexa(butyloxy)-22,25-diazaphthalocyanine,and TClPP is the dianion of 5,10,15,20-tetra(4-chloro)porphyrin)(1)was synthesized by mixed cyclic tetramerization of 5,10,15,20-tetrakis(4-chlorophenyl)-2′,3′-dicyanopyrazino[2,3-β]porphyrin with 4,5-di(butyloxy)phthalonitrile in the presence of lithium in refluxing n-pentanol followed by treatment with acetic acid.Reaction of the metal free dimer with Zn(OAc)2·2H2O in DMF and toluene led to the isolation of a bimetallic zinc(Ⅱ)complex Zn2{[(DAPc(OC4H9)6][(TClPP)]}(2).The binuclear and mixed tetrapyrrole ring nature of the structure was clearly demonstrated by a series of characterization methods including mass spectrometry and NMR spectroscopy.The Q band region of the electronic absorption and magnetic dichroism(MCD)spectra provide evidence for significant intramolecular interaction between the phthalocyanine and porphyrin chromophores.Theoretical calculations provide further support for this.%5,10,15,20-四(4-氯苯基)-2′,3′-二氰基[2,3-β]卟啉和4,5-二(丁烷氧基)邻二氰基苯在锂存在的条件下在正戊醇中回流四聚,然后用醋酸处理得到了一种新型的平面共轭酞菁二联体H4{[(DAPc(OC4H9)6][TClPP]}(1)(其中DAPc(OC4H9)6是2,3,9,10,16,17-六(丁烷氧基)-22,25-二氮杂酞菁的二价阴离子,TClPP是5,10,15,20-四(4-氯苯基)卟啉的二价阴离子).这种二联体和Zn(OAc)2·2H2O在DMF和甲苯混合溶剂中反应得到双金属配合物Zn2{[(DAPc(OC4H9)6[(TClPP)]}(2).质谱和核磁共振光谱等一系列的表征方法证明了这种双核的混杂四吡咯结构.电子吸收光谱和磁圆二色谱证明了酞菁发色团和卟啉发色团之间存在有效的分子内电子相互作用.这一结论进一步得到了理论计算的支持.

  8. 低频P波荷载下压电介质中共面裂纹的耦合断裂行为%Coupled fracture behavior of two coplanar cracks in piezoelectric material under low-frequency P-wave

    Institute of Scientific and Technical Information of China (English)

    张培伟

    2013-01-01

    The dynamic fracture problem of coplanar double rectangular cracks is constructed into a kind of boundary value problem, which is solved to compose the analytical expression of generalized stress fields, generalized intensity factors and energy release rate with the help of generalized Almansi'theorem.Rectangular crack is more suitable for analyzing and over-security for reliability. The boundary value problem is first transformed into three pairs of dual integral equations with the jump functions of the displacements across the crack surface as unknown functions.The unknown functions can be expanded directly into series of Jacobi polynomials which can be actually found close-form solution.Then, the analytical expressions for generalized singular stress at crack tip, gen-eralized intensity factors and energy release rate are strictly derived in form of infinite series.The nu-merical results are graphically shown to demonstrate intuitively effects of loading frequency as well as geometry on fracture criteria of cracks.And the correction of this method and the sophistication of crack propagation laws due to dynamic loads and couple effects are also verified.%对压电介质中共面裂纹的动态断裂问题进行建模,并求解该边界值问题。将裂纹形状等效为等面积的矩形以便于理论分析和增加安全评价的可靠性,采用一般Almansi理论得到了广义应力场、广义应力强度因子和能量释放率的解析表达式。考虑部分电导通裂纹边界条件,将边界值问题转换为3组对偶积分方程,并以裂纹上下表面的位移阶跃函数作为未知函数。通过将位移阶跃函数展开成Jacobi多项式,得到裂纹尖端的广义奇异应力、广义强度因子和能量释放率的解析解。最后,通过数值算例研究了P波载荷频率和矩形裂纹几何尺寸对裂纹扩展行为的影响规律。研究结果显示了该方法的正确性及在动载作用下裂纹相互作用引起

  9. Perinatal exposure to dioxins perturbs learning performance of the rat in a dose-specific fashion

    Energy Technology Data Exchange (ETDEWEB)

    Hojo, R.; Rieko, H.; Masaki, K.; Junzo, Y.; Chiharu, T. [National Inst. for Environmental Studies, Tsukuba (Japan)

    2004-09-15

    Dioxins (chlorinated dibenzo-p-dioxin congeners and related compounds including coplanar PCBs) are transferred transplacentally and lactationally from mothers to the developing brain of offspring. Maternal exposure to dioxins are suspected to cause adverse effects on the advanced brain function of offspring, because Previous studies indicate that the most toxic dioxin congener, 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD), affected the advanced brain function of rats, even when mothers had been exposed to a relatively low level of dioxins that would not affect themselves. In coplanar PCBs, which are dioxin-like, toxic equivalency factors (TEFs) are based on similar toxicity to TCDD and on a common mechanism of action, mediated by the aromatic hydrocarbon receptor (AhR). However, non-coplanar PCBs, which are considered to be non-dioxin-like PCBs, also show adverse effects on the learning and memory functions of offspring. In the present study, we hypothesize that coplanar PCBs have two types of toxicities, one is the similar to TCDD and the other is the specific toxicity of PCB itself. To address this hypothesis, effects of maternal exposure to one of the coplanar PCBs, 3,3',4,4',5-pentachlorobiphenyl (PCB126, 1997 WHO TEF = 0.1), on learning and behavioural performance of rats assessed by schedule-controlled operant behavior (SCOB) were examined and compared to TCDD.

  10. Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners

    Science.gov (United States)

    Saad, Hosam Ali; Abdel-Hafez, Shams Hashim

    2015-01-01

    Summary 3β-Azidocholest-5-ene (3) and (3β)-3-(prop-2-yn-1-yloxy)cholest-5-ene (10) were prepared as substrates to synthesize a variety of three-motif pharmacophoric conjugates through CuAAC. Basically, these conjugates included cholesterol and 1,2,3-triazole moieties, while the third, the pharmacophore, was either a chalcone, a lipophilic residue or a carbohydrate tag. These compounds were successfully prepared in good yields and characterized by NMR, MS and IR spectroscopic techniques. Chalcone conjugate 6c showed the best antimicrobial activity, while the lactoside conjugate 27 showed the best cytotoxic effect in vitro. PMID:26664612

  11. Estrogens and congeners from spent hops (Humulus lupulus).

    Science.gov (United States)

    Chadwick, Lucas R; Nikolic, Dejan; Burdette, Joanna E; Overk, Cassia R; Bolton, Judy L; van Breemen, Richard B; Fröhlich, Roland; Fong, Harry H S; Farnsworth, Norman R; Pauli, Guido F

    2004-12-01

    Estrogenicity-directed fractionation of a methanol extract of the strobiles of Humulus lupulus that had been extracted previously with supercritical CO(2), known as "spent hops", led to the isolation and identification of 22 compounds including 12 prenylated chalcones (1-8, 10-13), five prenylflavanones (14-17), 4-hydroxybenzaldehyde (18), sitosterol-3-O-beta-glucopyranoside (19), humulinone (20), and cohumulinone (21). In addition, the prenylated chalcone xanthohumol C (9a) was obtained as a 6:1 mixture along with its 1' ',2' '-dihydro derivative (9b). Three new chalcones (4, 11, 12) and four previously unreported constituents of hops (5, 6, 9b, 13) are reported. The structures of the new compounds were determined through a combination of spectrometric techniques including 1D and 2D NMR, HRESIMS, and ESIMS-MS. Full 1H NMR spin system analyses were performed to characterize the higher-order glucopyranosyl, prenyl, and chalcone B-ring spectra of the isolates. The principle estrogen 8-prenylnaringenin (15) from hops is an artifact formed along with its positional isomer 6-prenylnaringenin (16) through the spontaneous isomerization of the pro-estrogenic chalcone DMX (7).

  12. Functionalized Congener Approach to Muscarinic Antagonists: Analogues of Pirenzepine

    Science.gov (United States)

    Karton, Yishai; Bradbury, Barton J.; Baumgold, Jesse; Paek, Robert; Jacobson, Kenneth A.

    2012-01-01

    The M1-selective muscarinic receptor antagonist pirenzepine (5,11-dihydro-11-[(4-methyl-1-piperazinyl)acetyl]-6H-pyrido[2,3-b] [1,4]benzodiazepin-6-one) was derivatized to explore points of attachment of functionalized side chains for the synthesis of receptor probes and ligands for affinity chromatography. The analogues prepared were evaluated in competitive binding assays versus [3H]-N-methylscopolamine at four muscarinic receptor subtypes (m1AChR-m4AChR) in membranes from rat heart tissue and transfected A9L cells. 9-(Hydroxymethyl)pirenzepine, 8-(methylthio)pirenzepine, and a series of 8-aminosulfonyl derivatives were synthesized. Several 5-substituted analogues of pirenzepine also were prepared. An alternate series of analogues substituted on the 4-position of the piperazine ring was prepared by reaction of 4-desmethylpirenzepine with various electrophiles. An N-chloroethyl analogue of pirenzepine was shown to form a reactive aziridine species in aqueous buffer yet failed to affinity label muscarinic receptors. Within a series of aminoalkyl analogues, the affinity increased as the length of the alkyl chain increased. Shorter chain analogues were generally much less potent than pirenzepine, and longer analogues (7–10 carbons) were roughly as potent as pirenzepine at m1 receptors, but were nonselective. Depending on the methylene chain length, acylation or alkyl substitution of the terminal amine also influenced the affinity at muscarinic receptors. PMID:2066986

  13. Context mediates antimicrobial efficacy of kinocidin congener peptide RP-1.

    Directory of Open Access Journals (Sweden)

    Nannette Y Yount

    Full Text Available Structure-mechanism relationships are key determinants of host defense peptide efficacy. These relationships are influenced by anatomic, physiologic and microbiologic contexts. Structure-mechanism correlates were assessed for the synthetic peptide RP-1, modeled on microbicidal domains of platelet kinocidins. Antimicrobial efficacies and mechanisms of action against susceptible ((S or resistant ((R Salmonella typhimurium (ST, Staphylococcus aureus (SA, and Candida albicans (CA strain pairs were studied at pH 7.5 and 5.5. Although RP-1 was active against all study organisms, it exhibited greater efficacy against bacteria at pH 7.5, but greater efficacy against CA at pH 5.5. RP-1 de-energized SA and CA, but caused hyperpolarization of ST in both pH conditions. However, RP-1 permeabilized ST(S and CA strains at both pH, whereas permeabilization was modest for ST(R or SA strain at either pH. Biochemical analysis, molecular modeling, and FTIR spectroscopy data revealed that RP-1 has indistinguishable net charge and backbone trajectories at pH 5.5 and 7.5. Yet, concordant with organism-specific efficacy, surface plasmon resonance, and FTIR, molecular dynamics revealed modest helical order increases but greater RP-1 avidity and penetration of bacterial than eukaryotic lipid systems, particularly at pH 7.5. The present findings suggest that pH- and target-cell lipid contexts influence selective antimicrobial efficacy and mechanisms of RP-1 action. These findings offer new insights into selective antimicrobial efficacy and context-specificity of antimicrobial peptides in host defense, and support design strategies for potent anti-infective peptides with minimal concomitant cytotoxicity.

  14. Synthesis, antimicrobial and cytotoxicity evaluation of new cholesterol congeners

    Directory of Open Access Journals (Sweden)

    Mohamed Ramadan El Sayed Aly

    2015-10-01

    Full Text Available 3β-Azidocholest-5-ene (3 and (3β-3-(prop-2-yn-1-yloxycholest-5-ene (10 were prepared as substrates to synthesize a variety of three-motif pharmacophoric conjugates through CuAAC. Basically, these conjugates included cholesterol and 1,2,3-triazole moieties, while the third, the pharmacophore, was either a chalcone, a lipophilic residue or a carbohydrate tag. These compounds were successfully prepared in good yields and characterized by NMR, MS and IR spectroscopic techniques. Chalcone conjugate 6c showed the best antimicrobial activity, while the lactoside conjugate 27 showed the best cytotoxic effect in vitro.

  15. Divergolide congeners illuminate alternative reaction channels for ansamycin diversification.

    Science.gov (United States)

    Ding, Ling; Franke, Jakob; Hertweck, Christian

    2015-02-14

    Isolation and structure elucidation of six new divergolides reveal unusual ansamycin diversification reactions including formation of the unusual isobutenyl side chain from a branched polyketide synthase extender unit, azepinone ring closure, macrolide ring contraction and formation of a seco variant by a neighboring group-assisted decarboxylation.

  16. Antineoplastic activity of didemnin congeners: nordidemnin and modified chain analogues.

    Science.gov (United States)

    Jouin, P; Poncet, J; Dufour, M N; Aumelas, A; Pantaloni, A; Cros, S; François, G

    1991-02-01

    Nordidemnin (2), a natural analogue of the marine cyclodepsipeptide didemnin B (1b), showed cytotoxic activity against L1210 leukemia and antineoplastic activity against P388 leukemia as well as B16 melanoma; nordidemnin (2) was as active as didemnin B (1b). The influence of synthetic modifications in the linear peptidic chain on in vitro and in vivo activity was also studied. Replacement of the terminal lactyl residue by mandelyl and 3-(p-hydroxyphenyl)propionyl residues in compounds 3 and 4, respectively, did not affect the cytotoxic activity against L1210 leukemia (ID50 of 1.1 nM and 1.2 nM, respectively) or the in vivo activity against P388 leukemia. Unlike these aromatic substituants, the lipophilic palmityl residue induced a dramatic loss in cytotoxic activity. The inverted chirality of the MeLeu joining residue in compound 6 caused a marked reduction in the in vitro activity.

  17. Pseudomonas soli sp. nov., a novel producer of xantholysin congeners.

    Science.gov (United States)

    Pascual, Javier; García-López, Marina; Carmona, Cristina; Sousa, Thiciana da S; de Pedro, Nuria; Cautain, Bastien; Martín, Jesús; Vicente, Francisca; Reyes, Fernando; Bills, Gerald F; Genilloud, Olga

    2014-09-01

    A chemoorganotrophic Gram-negative bacterium was isolated by means of a diffusion sandwich system from a soil sample from the Sierra Nevada National Park, Spain. Strain F-279,208(T) was oxidase and catalase positive, strictly aerobic, non-spore-forming and motile by single polar flagellum. Phylogenetic analysis of the 16S rRNA, gyrB, rpoB and rpoD genes revealed that strain F-279,208(T) belongs to the Pseudomonas putida group with Pseudomonas mosselii and Pseudomonas entomophila as its closest relatives. DNA-DNA hybridization assays and phenotypic traits confirmed that this strain belongs to a novel species of the genus Pseudomonas, for which the name Pseudomonas soli sp. nov. is proposed. The type strain is F-279,208(T) (=DSM 28043(T)=LMG 27941(T)), and during fermentation it produces xantholysins, a family of lipodepsipeptides. The major compound, xantholysin A, showed an interesting activity in a RCC4 kidney tumor cell line with inactivation of VHL linked with the HIF pathway, without any cytotoxic effects against other human tumor cell lines tested including, liver, pancreas and breast.

  18. Ethologically based resolution of D2-like dopamine receptor agonist-versus antagonist-induced behavioral topography in dopamine- and adenosine 3',5'-monophosphate-regulated phosphoprotein of 32 kDa "knockout" mutants congenic on the C57BL/6 genetic background.

    Science.gov (United States)

    Nally, Rachel E; Kinsella, Anthony; Tighe, Orna; Croke, David T; Fienberg, Allen A; Greengard, Paul; Waddington, John L

    2004-09-01

    Given the critical role of dopamine- and adenosine 3',5'-monophosphate-regulated phosphoprotein of 32 kDa (DARPP-32) in the regulation of dopaminergic function, DARPP-32-null mutant mice congenic on the inbred C57BL/6 strain for 10 generations were examined phenotypically for their ethogram of responsivity to the selective D2-like receptor agonist RU 24213 (N-n-propyl-N-phenylethyl-p-3-hydroxyphenylethylamine) and the selective D2-like receptor antagonist YM 09151-2 (cis-N-[1-benzyl-2-methyl-pyrrolidin-3-yl]-5-chloro-2-methoxy-4-methylaminobenzamide), using procedures that resolve all topographies of behavior in the natural repertoire. After vehicle challenge, levels of sniffing and rearing seated were reduced in DARPP-32 mutants; the injection procedure seems to constitute a "stressor" that reveals phenotypic effects of DARPP-32 deletion not apparent under natural conditions. Topographical effects of 0.3 to 10.0 mg/kg RU 24213, primarily induction of sniffing and ponderous locomotion with accompanying reductions in rearing, grooming, sifting and chewing, were not altered to any material extent in DARPP-32-null mice. However, topographical effects of 0.005 to 0.625 mg/kg YM 09151-2, namely, reduction in sniffing, locomotion, rearing, grooming, and chewing but not sifting, were essentially absent in DARPP-32 mutants. Thus, the D2-like receptor agonist-mediated ethogram was essentially conserved, whereas major elements of the corresponding D2-like receptor antagonist-mediated ethogram were essentially absent in DARPP-32-null mice. This suggests some relationship between 1) extent of tonic dopaminergic activation of DARPP-32 mechanisms and 2) compensatory mechanisms consequent to the developmental absence of DARPP-32, which may emerge to act differentially on individual elements of the DARPP-32 system. Critically, the present data indicate that phenotypic effects of a given gene deletion using an agonist acting on the system disrupted cannot be generalized to a

  19. Non-Dioxin-Like PCBs: Effects and Consideration In Ecological Risk Assessment

    Science.gov (United States)

    An estimated one million metric tons of commercial mixtures of polychlorinated biphenyls (PCBs), such as Aroclors (USA), Kanechlors (Japan) and Clophens (Germany), were manufactured (WHO, 1993) and used worldwide as dielectric fluids

  20. Persistent organochlorine residues and toxic evaluation of polychlorinated biphenyls in sharks from the Mediterranean Sea (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Storelli, M.M.; Marcotrigiano, G.O. [Bari Univ., Dip. Farmaco-Biologico, Bari (Italy)

    2001-07-01

    Persistent organochlorines such as polychlorinated biphenyls including coplanar congeners, DDT compounds and HCB were measured in different tissues (muscle, liver and eggs) of two Mediterranean shark species: namely Centrophorus granulosus and Squalus blainvillei. The concentrations of organochlorines in the tissues and organs of both species were in the order DDTs>PCBs>HCB. The highest values of DDTs, PCBs and HCB were found in liver followed by eggs and muscle. Among DDTs the compound found in greatest concentration was p,p -DDE. The PCB profiles were dominated by congeners 138, 153, and 180. The isomers with higher TEQs values were non- and mono-ortho congeners than di-ortho ones in muscle, liver and eggs of both species. Among the non-ortho, PCB 126 was the major contributing individual to the total TEQs in both species. (Author)

  1. Marine mammal blubber reference and control materials for use in the determination of halogenated organic compounds and fatty acids

    Energy Technology Data Exchange (ETDEWEB)

    Kucklick, John R.; Pugh, Rebecca S.; Becker, Paul R. [Hollings Marine Laboratory, National Institute of Standards and Technology (NIST), Charleston, SC (United States); Schantz, Michele M.; Porter, Barbara J.; Poster, Dianne L.; Leigh, Stefan; Wise, Stephen A. [NIST, Analytical Chemistry Division, Gaithersburg, MD (United States); Rowles, Teri K. [National Marine Fisheries Service, National Oceanic and Atmospheric Administration, Silver Spring, MD (United States)

    2010-05-15

    The National Institute of Standards and Technology (NIST) has a diverse collection of control materials derived from marine mammal blubber, fat, and serum. Standard Reference Material (SRM) 1945 Organics in Whale Blubber was recertified for polychlorinated biphenyl (PCB) congeners, organochlorine pesticides, and polybrominated diphenyl ether (PBDE) congeners. SRM 1945 has also been assigned mass fraction values for compounds not frequently determined in marine samples including toxaphene congeners, coplanar PCBs, and methoxylated PBDE congeners which are natural products. NIST also has assigned mass fraction values, as a result of interlaboratory comparison exercises, for PCB congeners, organochlorine pesticides, PBDE congeners, and fatty acids in six homogenate materials produced from marine mammal blubber or serum. The materials are available from NIST upon request; however, the supply is very limited for some of the materials. The materials include those obtained from pilot whale blubber (Homogenates III and IV), Blainville's beaked whale blubber (Homogenate VII), polar bear fat (Homogenate VI), and California sea lion serum (Marine Mammal Control Material-1 Serum) and blubber (Homogenate V). (orig.)

  2. Composition and content of CBs, CDFs and CNs of Clophen A60

    Energy Technology Data Exchange (ETDEWEB)

    Taniyasu, S.; Horii, Y.; Hanari, N.; Yamashita, N. [National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba (Japan); Falandysz, J.; Swietojanska, A.; Flisak, M. [Gdansk Univ. (Poland). Dept. of Environmental Chemistry and Ecotoxicology; Petrick, G. [Kiel Univ. (Germany). Inst. for Marine Research

    2004-09-15

    Introduction Chlorobiphenyls (CBs; polychlorinated biphenyls, PCBs) starting from the year 1929 periodically become increasingly important and highly welcomed industrial compounds but further claimed as globally diffused environmental, food and human body contaminants. Those compounds, when contained in any man-derived product at concentration exceeding 50 mg/kg nowadays are considered as hazardous waste which should be safely disposed world-wide. Chlorobiphenyls form very complex mixtures with tens of congeners which are found and quantified as principal constituents in an original technical CB formulations manufactured. The technical CB mixtures such as Aroclor, Kanechlor or Delor series usually contain by-side trace constituents and including dioxin-like highly toxic substances such as chlorodibenzofurans (CDFs; polychlorinated dibenzofurans, PCDFs) and chloronaphthalenes (CNs; polychlorinated naphthalenes, PCNs), while no chlorodibenzo-p-dioxins (CDDs; polychlorinated dibenzo-pdioxins, PCDDs) could be detected. An introduced concept ''to take a short cut'' in analysis and assessment of the total CBs content of the sample includes measurement of selected ''indicator'' congeners, i.e. IUPAC Nos. 28, 52, 138, 153 and 180. The state-of-art approach when related to CBs environmental issues is to know and understand composition, absolute concentrations, environmental and body distribution, and elimination rates of all congeners constituting or contaminating the sample. Clophen A60 is one of the several technical chlorobiphenyl formulations of the Clophen family manufactured in the past by the Bayer AG (former I.G. Farben) in Germany. Congenerspecific data on CB composition of Clophen A60 as well as of Clophen A30, A40, A50, and T64 have been a subject of several earlier investigations. In this report qualitative and quantitative data are presented on chlorobiphenyl constituents of technical Clophen A60 and on it's some

  3. Orbital stability of coplanar two-planet exosystems with high eccentricities

    CERN Document Server

    Antoniadou, Kyriaki I

    2016-01-01

    The long-term stability of the evolution of two-planet systems is considered by using the general three body problem (GTBP). Our study is focused on the stability of systems with adjacent orbits when at least one of them is highly eccentric. In these cases, in order for close encounters, which destabilize the planetary systems, to be avoided, phase protection mechanisms should be considered. Additionally, since the GTBP is a non-integrable system, chaos may also cause the destabilization of the system after a long time interval. By computing dynamical maps, based on Fast Lyapunov Indicator, we reveal regions in phase space with stable orbits even for very high eccentricities (e>0.5). Such regions are present in mean motion resonances (MMR). We can determine the position of the exact MMR through the computation of families of periodic orbits in a rotating frame. Elliptic periodic orbits are associated with the presence of apsidal corotation resonances (ACR). When such solutions are stable, they are associated ...

  4. Optimization of infrared and magnetic shielding of superconducting TiN and Al coplanar microwave resonators

    Science.gov (United States)

    Kreikebaum, J. M.; Dove, A.; Livingston, W.; Kim, E.; Siddiqi, I.

    2016-10-01

    We present a systematic study of the effects of shielding on the internal quality factors ({Q}{{i}}) of Al and TiN microwave resonators designed for use in quantum coherent circuits. Measurements were performed in an adiabatic demagnetization refrigerator, where typical magnetic fields of 200 μT are present at the unshielded sample stage. Radiation shielding consisted of 100 and 500 mK Cu cans coated with infrared absorbing epoxy. Magnetic shields consisted of Cryoperm 10 and Sn plating of the Cu cans. A 2.7 K radiation can and coaxial thermalization filters were present in all measurements. TiN samples with {Q}{{i}}=1.3 × {10}6 at 100 mK exhibited no significant variation in quality factor when tested with limited shielding. In contrast, Al resonators showed improved {Q}{{i}} with successive shielding, with the largest gains obtained from the addition of the first radiation and magnetic shields and saturating before the addition of Sn plating infrared absorbing epoxy.

  5. A Strategy for Grasping unknown Objects based on Co-Planarity and Colour Information

    DEFF Research Database (Denmark)

    Popovic, Mila; Kraft, Dirk; Bodenhagen, Leon;

    2010-01-01

    In this work, we describe and evaluate a grasping mechanism that does not make use of any specific object prior knowledge. The mechanism makes use of second-order relations between visually extracted multi-modal 3D features provided by an early cognitive vision system. More specifically, the algo......In this work, we describe and evaluate a grasping mechanism that does not make use of any specific object prior knowledge. The mechanism makes use of second-order relations between visually extracted multi-modal 3D features provided by an early cognitive vision system. More specifically...... with a reasonable success rate in rather complex environments (i.e., cluttered scenes with multiple objects). Moreover, we have embedded the algorithm within a cognitive system that allows for autonomous exploration and learning in different contexts. First, the system is able to perform long action sequences which......, although the grasping attempts not being always successful, can recover from mistakes and more importantly, is able to evaluate the success of the grasps autonomously by haptic feedback (i.e., by a force torque sensor at the wrist and proprioceptive information about the distance of the gripper after...

  6. Architecture of Planetary Systems Based on Kepler Data: Number of Planets and Coplanarity

    CERN Document Server

    Fang, Julia

    2012-01-01

    We investigated the underlying architecture of planetary systems by deriving the distribution of planet multiplicity (number of planets) and the distribution of orbital inclinations based on the sample of planet candidates discovered by the Kepler mission. The scope of our study included solar-like stars and planets with orbital periods less than 200 days and with radii between 1.5 and 30 Earth radii, and was based on Kepler planet candidates detected during Quarters 1 through 6. We created models of planetary systems with different distributions of planet multiplicity and inclinations, simulated observations of these systems by Kepler, and compared the properties of the transits of detectable objects to actual Kepler planet detections. Specifically, we compared with both the Kepler sample's transit numbers and normalized transit duration ratios in order to determine each model's goodness-of-fit. We did not include any constraints from radial velocity surveys. Based on our best-fit models, 75-80% of planetary...

  7. On the optimization of the generalized coplanar Hohmann impulsive transfer adopting energy change concept

    Energy Technology Data Exchange (ETDEWEB)

    Kamel, Osman M. [Cairo Univ., Astronomy and Space Sciences Dept., Giza (Egypt); Soliman, Adel S. [National Research Center, Theoretical Physics Dept., Dokki, Giza (Egypt)

    2005-02-15

    We considered the problem of transferring the rocket's orbit to higher energy orbit, using minimum fuel cost, as a problem in change of energy, since this is most convenient. For the generalized Hohmann case (the departure; the transferring and the destination orbits are ellipses), we adopt the first configuration only, when the apogee of transfer orbit, and the apogee of destination orbit are coincident. Firstly, we assign the {delta}v{sub A}, {delta}v{sub B} increments in velocity at points A,B (the position of peri-apse and apo-apse impulses respectively), as functions of the eccentricity of the transfer orbit, e{sub T}. Subsequently, we apply the optimum condition leading to the derivation of the quartic equation in e{sub T}, and showed how to deduce ({delta}v{sub A}+{delta}v{sub B}){sub Min}. A numerical example is presented, in which we determined the four roots of the quartic equation, by a numerical Mathematica Version 2.2. We selected the adequate consistent root, only one in this case, and evaluated ({delta}v{sub A}+{delta}v{sub B}){sub Min} for the two orbits of the couple Earth and Mars. This article is a new approach and leads to new discoveries involved in the problem, consequently adds new insight and avoids complexities of previous procedures. (Author)

  8. Non-coplanar planet-disc interactions in binary star systems

    Science.gov (United States)

    Martin, Rebecca G.; Lubow, Stephen H.; Nixon, Chris; Armitage, Philip J.

    2016-06-01

    About half of observed exoplanets are estimated to be in binary systems. Thus, understanding planet formation and evolution in binaries is essential for explaining observed exoplanet properties. We will show how planet-disc interactions in a mildly inclined disc around one component of a binary can lead to the formation of highly eccentric and highly inclined planets.

  9. Multi-band microwave metamaterial absorber based on coplanar Jerusalem crosses

    Science.gov (United States)

    Wang, Guo-Dong; Liu, Ming-Hai; Hu, Xi-Wei; Kong, Ling-Hua; Cheng, Li-Li; Chen, Zhao-Quan

    2014-01-01

    The influence of the gap on the absorption performance of the conventional split ring resonator (SRR) absorber is investigated at microwave frequencies. Our simulated results reveal that the geometry of the square SRR can be equivalent to a Jerusalem cross (JC) resonator and its corresponding metamaterial absorber (MA) is changed to a JC absorber. The JC MA exhibits an experimental absorption peak of 99.1% at 8.72 GHz, which shows an excellent agreement with our simulated results. By simply assembling several JCs with slightly different geometric parameters next to each other into a unit cell, a perfect multi-band absorption can be effectively obtained. The experimental results show that the MA has four distinct and strong absorption peaks at 8.32 GHz, 9.8 GHz, 11.52 GHz and 13.24 GHz. Finally, the multi-reflection interference theory is introduced to interpret the absorption mechanism.

  10. Experiments on the interaction between long Josephson junctions and a coplanar strip resonator

    DEFF Research Database (Denmark)

    Davidson, A.; Pedersen, Niels Falsig

    1992-01-01

    Experiments are reported on a new geometry designed to couple long Josephson junction fluxon oscillators to a resonant cavity. The junctions were made with a niobium-aluminum oxide-niobium trilayer process with a critical-current density of around 1000 A/cm2. Various numbers of such junctions wer...

  11. Orbital stability of coplanar two-planet exosystems with high eccentricities

    Science.gov (United States)

    Antoniadou, Kyriaki I.; Voyatzis, George

    2016-10-01

    The long-term stability of the evolution of two-planet systems is considered by using the general three body problem (GTBP). Our study is focused on the stability of systems with adjacent orbits when at least one of them is highly eccentric. In these cases, in order for close encounters, which destabilize the planetary systems, to be avoided, phase protection mechanisms should be considered. Additionally, since the GTBP is a non-integrable system, chaos may also cause the destabilization of the system after a long time interval. By computing dynamical maps, based on Fast Lyapunov Indicator, we reveal regions in phase space with stable orbits even for very high eccentricities (e > 0.5). Such regions are present in mean motion resonances (MMRs). We can determine the position of the exact MMR through the computation of families of periodic orbits in a rotating frame. Elliptic periodic orbits are associated with the presence of apsidal corotation resonances (ACRs). When such solutions are stable, they are associated with neighbouring domains of initial conditions that provide long-term stability. We apply our methodology so that the evolution of planetary systems of highly eccentric orbits is assigned to the existence of such stable domains. Particularly, we study the orbital evolution of the extrasolar systems HD 82943, HD 3651, HD 7449, HD 89744 and HD 102272 and discuss the consistency between the orbital elements provided by the observations and the dynamical stability.

  12. A novel and simple coplanar waveguide-fed planar monopole antenna for ultra-wideband applications

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, a novel and simple CPW-fed planar monopole antenna is presented for UWB application. The antenna is fabricated on inexpensive FR4 substrate and fed by 50Ω CPW on the same layer. Measured data show that the antenna provides an impedance bandwidth of about 8GHz for the return loss less than 10dB. It is also observed that the radiation patterns are nearly omni-directional over the entire frequency range. Details of the proposed antenna are presented, and simulated results are presented and discussed.

  13. High-Q Superconducting Coplanar Waveguide Resonators for Integration into Molecule Ion Traps

    Science.gov (United States)

    2010-05-01

    200-6 (Hg Lamp), Tamarack Scientific Co. The mask was manually placed onto the sample, and a vacuum seal was placed around the mask to pump out any air ...all of the air had to be pumped out of it to minimize gas condensation. Once the sample holder was mounted on the cold head, the turbo was engaged...California Institute of Technology, 2008. [9] M. Goppl, A. Fragner, M. Baur, R. Bianchetti, S. Filipp, J. M. Fink, P. J. Leek, G. Puebla , L. Steffen, and A

  14. A Coplanar Waveguide Fed Rectangular Reconfigurable Patch Antenna with Switchable Strips for Polarization Diversity

    Directory of Open Access Journals (Sweden)

    Sulakshana Chilukuri

    2014-01-01

    Full Text Available A compact single feed rectangular patch antenna with reconfigurable circular polarization has been proposed in this paper. The basic antenna structure is a rectangular patch of dimensions 10 mm x 15 mm printed on a thin FR4 substrate of thickness 3 mm. Two rectangular strips are connected through switches at sideways of the main patch to get polarization diversity. The polarization of the proposed antenna can be reconfigured between left hand circular polarization (LHCP and right hand circular polarization (RHCP by the current path, which is changed by operating the switches in ON and OFF modes. The antenna is designed and simulated using IE3D MoM based electromagnetic simulator. The simulated results show good return loss, radiation pattern, axial ratio and acceptable gain at the operating frequency. The antenna has around 15 % effective impedance bandwidth over 4.0 GHz - 4.8 GHz frequency band at a maximum gain of 3.0 dBi with polarization diversity.Defence Science Journal, Vol. 64, No. 1, January 2014, DOI:10.14429/dsj.64.4807

  15. Optimization of infrared and magnetic shielding of superconducting TiN and Al coplanar microwave resonators

    CERN Document Server

    Kreikebaum, John Mark; Livingston, William; Kim, Eunseong; Siddiqi, Irfan

    2016-01-01

    We present a systematic study of the effects of shielding on the internal quality factors (Qi) of Al and TiN microwave resonators designed for use in quantum coherent circuits. Measurements were performed in an adiabatic demagnetization refrigerator, where typical magnetic fields of 200 {\\mu}T are present at the unshielded sample stage. Radiation shielding consisted of 100 mK and 500 mK Cu cans coated with infrared absorbing epoxy. Magnetic shields consisted of Cryoperm 10 and Sn plating of the Cu cans. A 2.7 K radiation can and coaxial thermalization filters were present in all measurements. TiN samples with Qi = $1.3*10^6$ at 100 mK exhibited no significant variation in quality factor when tested with limited shielding. In contrast, Al resonators showed improved Qi with successive shielding, with the largest gains obtained from the addition of the first radiation and magnetic shields and saturating before the addition of Sn plating infrared absorbing epoxy.

  16. Comparison of the in vitro effects of TCDD, PCB 126 and PCB 153 on thyroid-restricted gene expression and thyroid hormone secretion by the chicken thyroid gland.

    Science.gov (United States)

    Katarzyńska, Dorota; Hrabia, Anna; Kowalik, Kinga; Sechman, Andrzej

    2015-03-01

    The aim of this study was to compare the in vitro effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3',4,4',5-pentachlorobiphenyl (PCB 126; a coplanar PCB congener) and 2,2'4,4',5,5'-hexachlorobiphenyl (PCB153; non-coplanar PCB) on mRNA expression of thyroid-restricted genes, i.e. sodium iodide symporter (NIS), thyroid peroxidase (TPO) and thyroglobulin (TG), and thyroid hormone secretion from the thyroid gland of the laying chicken. Relative expression levels of NIS, TG and TPO genes and thyroxine (T4) and triiodothyronine (T3) secretion from the thyroidal explants were quantified by the real-time qPCR and RIA methods, respectively. In comparison with the control group, TCDD and PCB 126 significantly increased mRNA expression of TPO and TG genes. TCDD did not affect NIS mRNA levels, but PCB 126 decreased its expression. No effect of PCB 153 on the expression of these genes was observed. TCDD and PCB 126 significantly decreased T4 and T3 secretion. There was no significant effect of PCB 153 on these hormone secretions. In conclusion, the results obtained show that in comparison with non-coplanar PCB 153, TCDD and coplanar PCB 126 can directly affect thyroid hormone synthesis and secretion, and in consequence, they may disrupt the endocrine function of the thyroid gland of the laying chicken. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Effective range of reproductive interference exerted by an alien dandelion, Taraxacum officinale, on a native congener.

    Science.gov (United States)

    Takakura, Koh-Ichi; Matsumoto, Takashi; Nishida, Takayoshi; Nishida, Sachiko

    2011-03-01

    Reproductive interference (RI), defined as the fitness cost of interspecific sexual interactions, such as interspecific pollen transfer (IPT) in plants, is ecologically important. Theoretically, RI could result in competitive exclusion, as it operates in a frequency-dependent manner. Additionally, IPT may have a greater range than resource competition, although information about the range of IPT is lacking. In the present study, we measured the range of IPT exerted by Taraxacum officinale (an alien species) on a native dandelion, T. japonicum. We used two approaches. In one, we analyzed the RI effect on a native seed set at three spatial scales. In the second, we tracked IPT from alien to native flower heads using fluorescent pigments as markers. We estimated that pollination distances were in the order of several meters. These distances exceeded the mean distance from each native plant to the nearest alien. As hypothesized, the effect of RI reached farther than neighboring individuals. These data indicate the spatial range from which alien dandelions should be removed to allow the conservation of natives.

  18. Comparison of toxicity of congener-153 of PCB, PBB, and PBDE to Daphnia magna.

    Science.gov (United States)

    Nakari, Tarja; Huhtala, Sami

    2008-10-01

    Acute and reproductive toxicity tests were performed to assess the effects of two polybrominated flame retardants, polybrominated biphenyl (PBB)-153, polybrominated diphenyl ether (PBDE)-153, and polychlorinated biphenyl (PCB)-153 on Daphnia magna. According to the 24-h acute toxicity test, up to concentration of 210 microg/L, these chemicals were not toxic to Daphnia. In the reproductive tests, we used concentrations of 12.5, 25, 50, and 100 microg/L. At the concentrations of 50 and 100 microg/L, the Daphnia started to die after the second test day, and there were no Daphnia alive on the fourth test day. The testing was continued using the concentrations of 12.5 and 25 microg/L. The reproductive tests were then repeated using only concentrations of 12.5 and 25 microg/L. The results, based on the weight per volume (w/v) concentrations, showed that of the three compounds we tested PCB-153 had the most severe effects on the Daphnia reproduction. PBDE-153 was the least toxic, although in this group, too, offspring production was significantly lower and mortality significantly higher than those in the control group. Also, it was observed that PCB-153 accumulated into the parent Daphnia nearly three times more actively than the two other chemicals we tested. These chemicals, although having very similar structures, seem to affect differently the reproduction of Daphnia. They also seem to accumulate differently into Daphnia. Thus, further research data are needed to understand the mechanisms responsible for the effects caused by these kinds of chemicals and to assess their risks accurately.

  19. The Relationship between Dioxin Congeners in the Breast Milk of Vietnamese Women and Sister Chromatid Exchange

    Directory of Open Access Journals (Sweden)

    Hiroyuki Suzuki

    2014-04-01

    Full Text Available The aim of this study was to clarify the relationship between dioxin concentrations in breast milk and the sister chromatid exchange (SCE frequency in women from herbicide-sprayed and non sprayed areas. Blood samples were taken from 21 women with high TCDD (tetrachlorodibenzo-p-dioxin levels from sprayed areas, 23 women with moderate TCDD levels from sprayed areas, and 19 women from non sprayed areas to determine their SCE frequency. The SCE frequencies for the high and moderate TCDD groups from the sprayed area and for the non sprayed area group were 2.40, 2.19, and 1.48 per cell, respectively. Multiple regression analysis showed that the standardized β values for 1,2,3,6,7,8-hexaCDD (β = 0.60, 1,2,3,4,6,7,8-heptaCDD (β = 0.64, and octaCDD (β = 0.65 were higher than those for TCDD (β = 0.34 and 1,2,3,7,8-pentaCDD (β = 0.42. The adjusted R2 value for polyCDDs (R2 = 0.38 was higher than that for polyCDD toxic equivalents (TEQ (toxic equivalents; R2 = 0.23. This study therefore shows that levels of hexa-, hepta-, and octaCDD, which were previously regarded as being less toxic than TCDD, are closely related to SCE frequency and that the level of dioxin (pg/g lipid is potentially more useful as an indicator than TEQ value for explaining SCE frequency.

  20. Development and validation of a congener-specific photodegradation model for polybrominated diphenyl ethers

    NARCIS (Netherlands)

    Zeng, X.; Simonich, S.L.M.; Robrock, K.R.; Korytar, P.; Alvarez-Cohen, L.; Barofsky, D.F.

    2008-01-01

    With the phaseout of the manufacture of some polybrominated diphenyl ether ( PBDE) formulations, namely penta-brominated diphenyl ether (BDE) and octa-BDE, and the continued use of the deca-BDE formulation, it is important to be able to predict the photodegradation of the more highly brominated cong

  1. Palmitoylethanolamide and other anandamide congeners. Proposed role in the diseased brain

    DEFF Research Database (Denmark)

    Hansen, Harald S.

    2010-01-01

    (PEA), oleoylethanolamide (OEA), stearoylethanolamide (SEA), and several other quantitative minor species including anandamide (= arachidonoylethanolamide). PEA and OEA can activate several different receptors and inhibit some ion channels, e.g., PPARalpha, vanilloid receptor, K(+) channels (Kv4.3, Kv1...... modulating several biological functions mediated by GABA(A) receptors. The existence of acylethanolamides in the mammalian brain has been known for decades, but it is first within the last few years that the putative biological functions of the three most abundant acylethanolamides species are starting...

  2. Effect of highly bioaccumulated polychlorinated biphenyl congeners on estrogen and androgen receptor activity

    DEFF Research Database (Denmark)

    Bonefeld-Jørgensen, E.C.; Andersen, H. R.; Rasmussen, T.H.

    2001-01-01

    Polychlorinated biphenyls (PCBs) are ubiquitous environmental persistent contaminants giving rise to potential health hazard. Some PCBs exert dioxin-like activities mediated through the aryl hydrocarbon receptor. Although reports on interaction with other nuclear receptors are sparce, some...... in transiently co-transfected Chinese Hamster Ovary cells with an IC50, of 6.2 muM. In summary, this study indicate that the di-ortho, multiple-chloro substituted biphenyls, PCB # 138, PCB # 153 and PCB # 180, can compete with the binding of the natural ligand to two nuclear receptors and thus possess...

  3. Triggering the Formation of Direct Collapse Black Holes by Their Congeners

    Science.gov (United States)

    Yue, Bin; Ferrara, Andrea; Pacucci, Fabio; Omukai, Kazuyuki

    2017-04-01

    Direct collapse black holes (DCBHs) are excellent candidates for seeds of supermassive black holes observed at z ≳ 6. The formation of a DCBH requires a strong external radiation field to suppress H2 formation and cooling in a collapsing gas cloud. Such a strong field is not easily achieved by first stars or normal star-forming galaxies. Here we investigate a scenario in which a previously formed DCBH can provide the necessary radiation field for the formation of additional ones. Using a one-zone model and simulated DCBH Spectral Energy Distributions (SEDs) filtered through absorbing gas initially having column density N H, we derive the critical field intensity, {J}{LW}{crit}, to suppress H2 formation and cooling. For the SED model with {N}{{H}}=1.3× {10}25 cm‑2, 8.0 × 1024 cm‑2, and 5.0 × 1024 cm‑2, we obtain {J}{LW}{crit}≈ 22, 35, and 54, all much smaller than the critical field intensity for normal star-forming galaxies {J}{LW}{crit}≳ 1000 X-ray photons from previously formed DCBHs build up a high-z X-ray background (XRB) that may boost the {J}{LW}{crit}. However, we find that in the three SED models, {J}{LW}{crit} only increases to ≈80, 170, and 390, even when {\\dot{ρ }}\\bullet reaches the maximum value allowed by the present-day XRB level (0.22, 0.034, 0.006 M ⊙ yr‑1 Mpc‑3), which is still much smaller than the galactic value. Although considering the XRB from first galaxies may further increase {J}{LW}{crit}, we conclude that our investigation supports a scenario in which DCBHs may be more abundant than predicted by models only including galaxies as external radiation sources.

  4. Testing the importance of plant strategies on facilitation using congeners in a coastal community.

    Science.gov (United States)

    He, Qiang; Cui, Baoshan; Bertness, Mark D; An, Yuan

    2012-09-01

    Much is known about how environmental stress mediates the strength of facilitation, but less is known about how different plant traits affect facilitation. We examined interactions between the shrub Tamarix chinensis and two congeneric forbs (Suaeda salsa and S. glauca) on the Chinese coast. Although S. salsa and S. glauca are both annuals, morphologically similar, and have synchronous phenologies, they have contrasting adaptive strategies. S. glauca is salt intolerant but competitively superior, and S. salsa is salt tolerant but competitively inferior. Field surveys showed that S. glauca was associated with T. chinensis canopies while S. salsa was more abundant in open areas. A T. chinensis removal experiment showed that S. glauca cover was lower and soil salinity higher after two years in removal than in control plots. Transplant experiments showed that S. salsa performance under T. chinensis canopies was reduced by competition from S. glauca and T. chinensis, while in open areas S. glauca was not affected by S. salsa competition. Thus, contrasting competitive abilities and stress tolerances of S. glauca and S. salsa underlie their facilitative and competitive interactions with T. chinensis, suggesting that plant strategies are critical to the outcome of species interactions.

  5. REMOVAL OF SELECTED CONGENERS OF POLYCYCLIC AROMATIC HYDROCARBONS FROM THE BOTTOM SEDIMENTS USING CHEMICAL OXIDATION

    Directory of Open Access Journals (Sweden)

    Sabina Książek

    2016-06-01

    Full Text Available Bottom sediments are the part of the aquatic ecosystem, which accumulates most of pollution emitted into environment and flowing into surface waters. This concerns of nutrients, heavy metals and Persistent Organic Pollutants, which include, among others, polycyclic aromatic hydrocarbons (PAHs. PAHs are toxic, carcinogenic mutagenic and teratogenic compounds. The aim of this study was to evaluate the usefulness of chemical oxidation to remove selected PAH contained in bottom sediments. Oxidation of the impurities were carried out using 30% solution of hydrogen peroxide and with the addition of H2O2 with the catalyst FeSO4x7H2O (the Fenton’s method. The efficiency of oxidation was evaluated on the basis of changes in the content of tested impurities, which was determined by gas chromatography coupled with the mass spectrometer (GC-MS after extraction of analytes from bottom sediments. Preliminary studies have shown the efficacy of the use of H2O2 and the Fenton’s method to remove of selected PAHs.

  6. Congener specific distribution and health risk assessment of polychlorinated biphenyls in urban soils

    Directory of Open Access Journals (Sweden)

    Bhupander Kumar

    2012-10-01

    Full Text Available Polychlorinated biphenyls (PCBs were primarily used in transformers and capacitors, lubricants, flame retardants, plasticizers, paint, carbonless papers, etc. These are capable of long-range atmospheric transport and have been designated as persistent organic pollutants by the Stockholm Convention. Due to their characteristic properties, PCBs are found worldwide in all environmental matrices (including human and biota. Soils are usually considered to be the source as well as sink for environmental pollutants, with cumulative effects of long-range atmospheric transport and local sources. Around the world, comparatively higher concentrations of PCBs have been reported in urban soils than suburban or rural soils. Higher amount of PCBs in urban soils may cause toxicological health risks to urban residents through ingestion, inhalation and skin contact. This paper presents the PCB distribution in soils from Delhi, India, and exposure risk estimates for human health through soil ingestion. The concentration of ΣPCBs ranged between 1.08-100.67 ng g–1 (mean 21.16 ng g–1±5.24 ng g–1, which was much lower than the Canadian soil quality guideline value of 1.3 mg/kg or 1300 ng g–1. Human health risk estimates through the soil ingestion pathway were made in terms of lifetime average daily dose (LADD, incremental lifetime cancer risks and non-carcinogenic hazard quotient (HQ. The LADD for Delhi adults and children was 3.02x10–8 mg kg–1 d–1 and 1.57x10–7 mg kg–1 d–1, respectively, which corresponds to toxic equivalent quotients (TEQ intake of 0.105 pg TEQ kg–1 d–1 (0.735 pg TEQ kg–1 week–1 and 0.543 pg TEQ kg–1 d–1 (3.801 pg TEQ kg–1 week–1, respectively. The estimated LADD for Delhi residents was lower than the acceptable intake values recommended by the World Health Organization (1 pg TEQ kg–1 d–1, the European Commission (14 pg TEQ kg–1;1 week–1 and by the Japanese government (4 pg TEQ kg–1 d–1. The probability of cancer risk ranges from 6.04x10–8 (ΣPCBs to 1.57x10–5 (ΣTEQ and 3.13x10–7 (ΣPCBs to 8.15x10–5 (ΣTEQ for adults and children, respectively, and was within acceptable ranges of 10–6 to 10–4. The non-carcinogenic risk in terms of health HQ was 0.105 and 0.330 for adults and children, respectively, which was lower than the acceptable limit of 1. The study found lower concentrations of PCBs than guideline values and low health risk estimates through the soil ingestion pathway within acceptable levels, indicating a minimum risk for Delhi residents.

  7. Isolation, Identification, and Origin of Three Previously Unknown Congeners in Illicit Cocaine

    NARCIS (Netherlands)

    Ensing, Jacob; Hummelen, Jan C.

    1991-01-01

    Three previously unknown, overlooked, or perhaps wrongly identified impurities in illicit cocaine seized in the Netherlands Antilles are traced by various combinations of chromatographic and extraction methods. Once isolated using high-performance liquid chromatography, the compounds are identified

  8. The Mass Spectrometric Ortho Effect Studied for All 209 PCB Congeners

    Science.gov (United States)

    A method for the determination of polychlorinated biphenyls (PCBs) in caulk was developed; with application to a set of caulk and window glazing material samples. This method was evaluated by analyzing a combination of 47 samples of caulk, glazing materials, and including quality...

  9. Novel chemistry of invasive plants: exotic species have more unique metabolomic profiles than native congeners

    NARCIS (Netherlands)

    Macel, M.; Vos, de R.C.H.; Jansen, J.J.; Putten, van der W.H.; Dam, van N.M.

    2014-01-01

    It is often assumed that exotic plants can become invasive when they possess novel secondary chemistry compared with native plants in the introduced range. Using untargeted metabolomic fingerprinting, we compared a broad range of metabolites of six successful exotic plant species and their native co

  10. Mast cell-glia axis in neuroinflammation and therapeutic potential of the anandamide congener palmitoylethanolamide.

    Science.gov (United States)

    Skaper, Stephen D; Facci, Laura

    2012-12-05

    Communication between the immune and nervous systems depends a great deal on pro-inflammatory cytokines. Both astroglia and microglia, in particular, constitute an important source of inflammatory mediators and may have fundamental roles in central nervous system (CNS) disorders from neuropathic pain and epilepsy to neurodegenerative diseases. Glial cells respond also to pro-inflammatory signals released from cells of immune origin. In this context, mast cells are of particular relevance. These immune-related cells, while resident in the CNS, are able to cross a compromised blood-spinal cord and blood-brain barrier in cases of CNS pathology. Emerging evidence suggests the possibility of mast cell-glia communication, and opens exciting new perspectives for designing therapies to target neuroinflammation by differentially modulating the activation of non-neuronal cells normally controlling neuronal sensitization-both peripherally and centrally. This review aims to provide an overview of recent progress relating to the pathobiology of neuroinflammation, the role of glia, neuro-immune interactions involving mast cells and the possibility that glia-mast cell interactions contribute to exacerbation of acute symptoms of chronic neurodegenerative disease and accelerated disease progression, as well as promotion of pain transmission pathways. Using this background as a starting point for discussion, we will consider the therapeutic potential of naturally occurring fatty acid ethanolamides, such as palmitoylethanolamide in treating systemic inflammation or blockade of signalling pathways from the periphery to the brain in such settings.

  11. Mast cell–glia axis in neuroinflammation and therapeutic potential of the anandamide congener palmitoylethanolamide

    OpenAIRE

    2012-01-01

    Communication between the immune and nervous systems depends a great deal on pro-inflammatory cytokines. Both astroglia and microglia, in particular, constitute an important source of inflammatory mediators and may have fundamental roles in central nervous system (CNS) disorders from neuropathic pain and epilepsy to neurodegenerative diseases. Glial cells respond also to pro-inflammatory signals released from cells of immune origin. In this context, mast cells are of particular relevance. The...

  12. Alkaloids and athlete immune function: caffeine, theophylline, gingerol, ephedrine, and their congeners.

    Science.gov (United States)

    Senchina, David S; Hallam, Justus E; Kohut, Marian L; Nguyen, Norah A; Perera, M Ann d N

    2014-01-01

    Plant alkaloids are found in foods, beverages, and supplements consumed by athletes for daily nutrition, performance enhancement, and immune function improvement. This paper examined possible immunomodulatory roles of alkaloids in exercise contexts, with a focus on human studies. Four representative groups were scrutinized: (a) caffeine (guaranine, mateine); (b) theophylline and its isomers, theobromine and paraxanthine; (c) ginger alkaloids including gingerols and shogaol; and (d) ephedra alkaloids such as ephedrine and pseudoephedrine. Emerging or prospective alkaloid sources (Goji berry, Noni berry, and bloodroot) were also considered. Human in vitro and in vivo studies on alkaloids and immune function were often conflicting. Caffeine may be immunomodulatory in vivo depending on subject characteristics, exercise characteristics, and immune parameters measured. Caffeine may exhibit antioxidant capacities. Ginger may exert in vivo anti-inflammatory effects in certain populations, but it is unclear whether these effects are due to alkaloids or other biochemicals. Evidence for an immunomodulatory role of alkaloids in energy drinks, cocoa, or ephedra products in vivo is weak to nonexistent. For alkaloid sources derived from plants, variability in the reviewed studies may be due to the presence of unrecognized alkaloids or non-alkaloid compounds (which may themselves be immunomodulatory), and pre-experimental factors such as agricultural or manufacturing differences. Athletes should not look to alkaloids or alkaloid-rich sources as a means of improving immune function given their inconsistent activities, safety concerns, and lack of commercial regulation.

  13. Baseline survey of concentrations of toxaphene congeners in fish from European waters

    NARCIS (Netherlands)

    McHugh, B.; McGovern, E.; Nixon, E.; Klungsoeyr, J.; Rimkus, G.G.; Leonards, P.E.G.; Boer, de J.

    2004-01-01

    The European Union project "Investigation into the monitoring, analysis and toxicity of toxaphene'' ( MATT) began in 1997 involving participants from the Netherlands, Ireland, Norway and Germany. Concentration information, analytical methodology and statistical interpretation of 207 samples covering

  14. Genome downsizing and karyotype constancy in diploid and polyploid congeners: a model of genome size variation.

    Science.gov (United States)

    Poggio, Lidia; Realini, María Florencia; Fourastié, María Florencia; García, Ana María; González, Graciela Esther

    2014-06-26

    Evolutionary chromosome change involves significant variation in DNA amount in diploids and genome downsizing in polyploids. Genome size and karyotype parameters of Hippeastrum species with different ploidy level were analysed. In Hippeastrum, polyploid species show less DNA content per basic genome than diploid species. The rate of variation is lower at higher ploidy levels. All the species have a basic number x = 11 and bimodal karyotypes. The basic karyotypes consist of four short metacentric chromosomes and seven large chromosomes (submetacentric and subtelocentric). The bimodal karyotype is preserved maintaining the relative proportions of members of the haploid chromosome set, even in the presence of genome downsizing. The constancy of the karyotype is maintained because changes in DNA amount are proportional to the length of the whole-chromosome complement and vary independently in the long and short sets of chromosomes. This karyotype constancy in taxa of Hippeastrum with different genome size and ploidy level indicates that the distribution of extra DNA within the complement is not at random and suggests the presence of mechanisms selecting for constancy, or against changes, in karyotype morphology.

  15. Isolation, Identification, and Origin of Three Previously Unknown Congeners in Illicit Cocaine

    NARCIS (Netherlands)

    Ensing, Jacob; Hummelen, Jan C.

    1991-01-01

    Three previously unknown, overlooked, or perhaps wrongly identified impurities in illicit cocaine seized in the Netherlands Antilles are traced by various combinations of chromatographic and extraction methods. Once isolated using high-performance liquid chromatography, the compounds are identified

  16. Spectrophotometric determination of phenol in the presence of congeners by multivariated calibration

    Directory of Open Access Journals (Sweden)

    KELY VIVIANE DE SOUZA

    2001-12-01

    Full Text Available The generation of poly-hydroxilated transient species during the photochemical treatment of phenol usually impedes the spectrophotmetric monitoring of its degradation process. Frequently, the appearance of compounds such as pyrocatechol, hydroquinone and benzoquinone produces serious spectral interference, which hinder the