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Sample records for 75as 164dy 170er

  1. Radiative strength functions in {sup 163,164}Dy

    SciTech Connect

    Nyhus, H. T.; Siem, S.; Guttormsen, M.; Larsen, A. C.; Buerger, A.; Syed, N. U. H.; Tveten, G. M.; Voinov, A.

    2010-02-15

    The nuclei {sup 163,164}Dy have been investigated using the Oslo method on data from the pickup reaction {sup 164}Dy({sup 3}He,{alpha}{gamma}){sup 163}Dy and the inelastic scattering {sup 164}Dy({sup 3}He,{sup 3}He{sup '}{gamma}){sup 164}Dy, respectively. The radiative strength functions for both nuclei have been extracted, and a small resonance centered around E{sub {gamma}}approx =3 MeV is observed in both cases. The parameters of this so-called pygmy M1 resonance (the scissors mode) are compared with previous results on {sup 160,161,162}Dy using the Oslo method, and with data on {sup 163}Dy measured by the Prague group using the two-step cascade method. In particular, the integrated reduced transition probability B(M1arrow up) of the pygmy resonance is compared with neighboring dysprosium isotopes. We also observe an enhanced strength in the region above E{sub {gamma}}approx =5 MeV in {sup 164}Dy. Possible origins of this feature are discussed.

  2. A new method of making 164Dy metal plate targets

    NASA Astrophysics Data System (ADS)

    Sugai, Isao; Kato, Hajime

    1986-04-01

    164Dy metal plate targets of high purity for measurements of the electron neutrino mass were made successfully. The starting material 164DyF 3 was reduced to metal by the Ca reduction method with rf induction heating. The reduced metal was pressed with a hot-press device in argon gas atmosphere and rolled into plates of 35 mm × 10 mm in area by a new method of packing. The thicknesses were in the range from 150 to 230 mg/cm 2. The present method was also found suitable to make thin Dy targets of the order of 1 mg/cm 2 in thickness

  3. Mean-field predictions for a dipolar Bose-Einstein condensate with 164Dy

    NASA Astrophysics Data System (ADS)

    Zajec, Damir; Wunner, Günter

    2015-11-01

    Dipolar Bose-Einstein condensates are systems well suited for the investigation of effects caused by the nonlocal and anisotropic dipole-dipole interaction. In this paper we are interested in properties which are directly connected to the realization of a condensate with 164Dy , such as stability and phase diagrams. Additionally, we study the expansion of dipolar condensates and find signatures of the dipole-dipole interaction in terms of structured states and a deviation of the well-known inversion of the aspect ratio of the cloud during a time of flight. Our analysis is based on the extended Gross-Pitaevskii equation, which we solve numerically exactly on a grid by means of an imaginary- and real-time evolution.

  4. Electromagnetic properties of vibrational bands in 170Er

    NASA Astrophysics Data System (ADS)

    DiJulio, D. D.; Cederkall, J.; Fahlander, C.; Ekström, A.; Golubev, P.; Mattsson, K.; Rudolph, D.; de Angelis, G.; Aydin, S.; Deo, A. Y.; Farnea, E.; Farrelly, G.; Geibel, K.; He, C.; Iwanicki, J.; Kempley, R.; Marginean, N.; Menegazzo, R.; Mengoni, D.; Orlandi, R.; Podolyak, Z.; Recchia, F.; Reiter, P.; Sahin, E.; Smith, J.; Söderström, P. A.; Torres, D. A.; Tveten, G. M.; Ur, C. A.; Valiente-Dobón, J. J.; Wendt, A.; Zielińska, M.

    2011-02-01

    Excited states of the nucleus 170Er have been studied by Coulomb excitation using the GASP γ -ray detector system at the Laboratori Nazionali di Legnaro. The ground-state band along with a low-lying ensuremath K^{π}=0^+ band and γ -vibrational band were populated during the experiment. Based on the measured γ -ray yields, a set of interband and intraband matrix elements has been extracted using the Coulomb excitation code GOSIA. The resulting E2 matrix elements are compared to collective model predictions.

  5. On the absence of rotational levels for J{sup π}K = 0{sup +}0{sub 2} and 2{sup +}2{sub 2} nonrotational states in {sup 164}Dy and {sup 166}Er

    SciTech Connect

    Govor, L. I. Demidov, A. M.; Kurkin, V. A.; Mikhailov, I. V.

    2015-03-15

    Various reasons for the absence of rotational levels for J{sup π}K = 0{sup +}0{sub 2} and 2{sup +}2{sub 2} nonrotational states in {sup 164}Dy and {sup 166}Er are considered. Preference is given to the effect of the excitation of an anharmonic two-phonon state in pair vibrations of the superconducting type.

  6. Two-quasiparticle structures and isomers in {sup 168}Er, {sup 170}Er, and {sup 172}Er.

    SciTech Connect

    Dracoulis, G. D.; Lane, G. J.; Kondev, F. G.; Watanabe, H.; Seweryniak, D.; Zhu, S.; Carpenter, M. P.; Chiara, C. J.; Janssens, R. V. F.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Stefanescu, I.; Australian National Univ.; RIKEN; Univ. of Maryland

    2010-05-01

    The stable and neutron-rich isotopes 168Er, 170Er, and 172Er have been studied with Gammasphere using inelastic excitation with energetic 136Xe beams. The previously assigned structures based on the proposed K?=4- isomeric intrinsic states in both 168Er and 170Er have been re-evaluated and an equivalent band identified in 172Er. In 170Er, the identification of a K?=6- band with transitions close in energy to those of the 4- band leads to a modified interpretation, since the overlap would have compromised previous analyses. The gK-gR values for the 4- bands deduced from the in-band ?-ray intensities for the sequence of isotopes suggest a predominantly two-neutron configuration in 168Er, an equally mixed two-neutron, two-proton configuration in 170Er, and a two-proton configuration in 172Er. A comprehensive decay scheme for the previously proposed 6+ isomer in 172Er has also been established, as well as band structures built on this isomer that closely resemble the 6+ and 7- two-neutron structures known in the isotone 174Yb. The implied K hindrances are discussed. The main decay path of the 6+ isomer occurs through the newly identified 4- isomer. The measured lifetimes of the 4- and 6+ isomers in 172Er are 57(3) and 822(90) ns, respectively. Multiquasiparticle calculations support the suggested configuration changes across the isotopic chain.

  7. Measurement of thermal neutron cross section and resonance integral for the {sup 170}Er(n,{gamma}){sup 171}Er reaction by using a {sup 55}Mn monitor

    SciTech Connect

    Yuecel, Haluk; Budak, M. Gueray; Karadag, Mustafa

    2007-09-15

    The thermal neutron cross section and the resonance integral of the reaction {sup 170}Er(n,{gamma}){sup 171}Er were measured by the Cd-ratio method using a {sup 55}Mn monitor as single comparator. Analytical grade MnO{sub 2} and Er{sub 2}O{sub 3} powder samples with and without a cylindrical 1 mm Cd shield box were irradiated in an isotropic neutron field obtained from three {sup 241}Am-Be neutron sources. The induced activities in the samples were measured with a 120.8% relative efficiency p-type HPGe detector. The correction factors for gamma-ray attenuation (F{sub g}), thermal neutron self-shielding (G{sub th}), and resonance neutron self-shielding (G{sub epi}) effects, and the epithermal neutron spectrum shape factor ({alpha}) were taken into account. The thermal neutron cross section for the (n,{gamma}) reaction in {sup 170}Er has been determined to be 8.00 {+-} 0.56 b, relative to that of the {sup 55}Mn monitor. However, some previously reported experimental results compared to the present result show a large discrepancy ranging from 8.3 to 86%. The present result is, in general, in good agreement with the recently measured values by 9%. According to the definition of Cd cut-off energy at 0.55 eV, the resonance integral obtained is 44.5 {+-} 4.0 b, which is determined relative to the reference integral value of the {sup 55}Mn monitor by using cadmium ratios. The existing experimental data for the resonance integral are distributed between 18 and 43 b. The present resonance integral value agrees only with the measurement of 43 {+-} 5 b by Gillette [Thermal Cross Section and Resonance Integral Studies, ORNL-4155, 15 (1967)] within uncertainty limits.

  8. Neutron Capture Surrogate Reaction on 75As in Inverse Kinematics Using (d,p(gamma))

    SciTech Connect

    Peters, W A; Cizewski, J A; Hatarik, R; O?Malley, P D; Jones, K L; Schmitt, K; Moazen, B H; Chae, K Y; Pittman, S T; Kozub, R L; Vieira, D; Jandel, M; Wilhelmy, J B; Matei, C; Escher, J; Bardayan, D W; Pain, S D; Smith, M S

    2009-11-09

    The {sup 75}As(d,p{gamma}) reaction in inverse kinematics as a surrogate for neutron capture was performed at Oak Ridge National Laboratory using a deuterated plastic target. The intensity of the 165 keV {gamma}-ray from {sup 76}As in coincidence with ejected protons, from exciting {sup 76}As above the neutron separation energy populating a compound state, was measured. A tight geometry of four segmented germanium clover {gamma}-ray detectors together with eight ORRUBA-type silicon-strip charged-particle detectors was used to optimize geometric acceptance. The preliminary analysis of the {sup 75}As experiment, and the efficacy and future plans of the (d,p{gamma}) surrogate campaign in inverse kinematics, are discussed.

  9. 75 As and 59Co NMR studies of SrCo2As2

    NASA Astrophysics Data System (ADS)

    Furukawa, Yuji; Ogloblichev, Vasily; Pandey, Abhisek; Johnston, David C.

    2015-03-01

    After the discovery of unconventional superconductivity in Fe pnictides with the ThCr2Si2-type structure, much attention has been paid to the related materials AM2As2(A = Ca, Sr, and Ba, and M = Co, Ni, Mn, and Cu). We have been studying the electronic and magnetic properties of these related materials systematically. Among them, metallic SrCo2As2 is an interesting system because inelastic neutron scattering measurements indicate strong stripe-type antiferromagnetic correlations, similar to the Fe pnictide superconductors. In order to investigate the magnetic and electronic properties of SrCo2As2 from a microscopic point of view, we carried out 59Co and 75As NMR in the temperature range T = 1.3 - 300 K. In this talk, based on 59Co NMR data including 75As NMR results published previously, we discuss the characteristic magnetic fluctuations in the system and compare them with those measured from NMR data for another cobalt arsenide BaCo2As2. Supported by USDOE under Contract No. DE-AC02-07CH11358.

  10. Anomalous superconducting state in LiFeAs implied by the 75As Knight shift measurement

    NASA Astrophysics Data System (ADS)

    Baek, S.-H.; Harnagea, L.; Wurmehl, S.; Büchner, B.; Grafe, H.-J.

    2013-04-01

    75As NMR investigation of a single crystal of superconducting LiFeAs is presented. The Knight shift and the in situ ac susceptibility measurements as a function of temperature and external field are indicative of two superconducting (SC) transition temperatures, each of which is associated with its own upper critical field. Strikingly, the Knight shift maintains its normal state value over a temperature range in the SC state before it drops abruptly, being consistent with spin-singlet pairing. Together with our previous NMR study, the anomalous SC state featuring the constant Knight shift is attributed to the extremely sensitive SC properties of LiFeAs, probably stemming from its proximity to a critical instability.

  11. Electronic and magnetic properties of Ca(Fe1-xCox)2 As2 studied by 75As NMR

    NASA Astrophysics Data System (ADS)

    Furukawa, Yuji; Roy, Beas; Ran, Shen; Bud'Ko, Sergey L.; Canfield, Paul C.

    2014-03-01

    Recently much attention has been paid to CaFe2As2 because the magnetic and electronic properties of the system can be controlled by changing the heat treatment conditions. CaFe2As2 annealed at 400 C for 24 hours undergoes a phase transition from a high-temperature tetragonal paramagnetic state to a low temperature orthorhombic antiferromagnetic state at TN ~ 160K. On the other hand, CaFe2As2 quenched from 960 C to room temperature shows a transition to a collapsed tetragonal non-magnetic phase below Ts ~ 90 K. In order to investigate the difference in electronic and magnetic properties of the two different CaFe2As2 samples from a microscopic point of view, we have carried 75As-NMR spectra and spin-lattice relaxation measurements. We also performed 75As-NMR measurements on Co-doped CaFe2As2 superconductor. Based on our NMR data, we will discuss similarities and difference in magnetic fluctuations in the systems, and compare the NMR data with inelastic neutron scattering data. Supported by USDOE under the Contract No. DE-AC02-07CH11358.

  12. First order magnetic transition in single crystal CaFe2As2 detected by 75As NMR

    SciTech Connect

    Baek, Seung Ho; Curro, Nicholas J

    2008-01-01

    We report {sup 75}As Nuclear Magnetic Resonance data in a single crystal of CaFe{sub 2}As{sub 2}. The Knight shift, the electric field gradient, and the spin lattice relaxation rate are strongly temperature dependent in the paramagnetic state, and change discontinuously at the structural transition temperature, T{sub S} = T{sub N} = 167 K. Immediately below, the NMR spectra reveal an internal field at the As site associated with the presence of a commensurate magnetic order. These results indicate that the structural and magnetic transitions in CaFe{sub 2}As{sub 2} are first order and strongly coupled, and that the electron density in the FeAs plane is highly sensitive to the out-of-plane structure.

  13. Ferromagnetic Spin Fluctuation and Unconventional Superconductivity in Rb2Cr3As3 Revealed by 75As NMR and NQR

    NASA Astrophysics Data System (ADS)

    Yang, J.; Tang, Z. T.; Cao, G. H.; Zheng, Guo-qing

    2015-10-01

    We report 75As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) studies on the superconductor Rb2Cr3As3 with a quasi-one-dimensional crystal structure. Below T ˜100 K , the spin-lattice relaxation rate (1 /T1 ) divided by temperature, 1 /T1T , increases upon cooling down to Tc=4.8 K , showing a Curie-Weiss-like temperature dependence. The Knight shift also increases with decreasing temperature. These results suggest ferromagnetic spin fluctuation. In the superconducting state, 1 /T1 decreases rapidly below Tc without a Hebel-Slichter peak, and follows a T5 variation below T ˜3 K , which points to unconventional superconductivity with point nodes in the gap function.

  14. 75As NMR study of the oriented pnictide superconducting compound NdFeAsO0.83F0.17

    NASA Astrophysics Data System (ADS)

    Pahari, Bholanath

    2016-05-01

    Magnetization and 75As nuclear magnetic resonance (NMR) measurements in the superconductor NdFeAsO0.83F0.17 (TC~46 K) are performed in order to investigate the effect of the Nd 4f electrons in the superconducting property. The magnetization curve displays a Nd 4f moments generated Curie-Weiss signal in the field of 7 T. 75As NMR spectra in the oriented sample (H0‖ab) are recorded at 7 T in the temperature range 10-300 K and temperature dependent 75As NMR shift, Kab has been obtained. The Kab curve shows a Curie-Weiss type contribution. The magnitude of hyperfine field, Hhf (4.4 kOe/μB) estimated from the Kab vs χ plot indicates a non-negligible RKKY-type interaction between localized Nd 4f moments mediated by itinerant Fe 3d electrons.

  15. Coexistence of multiple charge-density waves and superconductivity in SrPt2As2 revealed by 75As-NMR /NQR and 195Pt-NMR

    NASA Astrophysics Data System (ADS)

    Kawasaki, Shinji; Tani, Yoshihiko; Mabuchi, Tomosuke; Kudo, Kazutaka; Nishikubo, Yoshihiro; Mitsuoka, Daisuke; Nohara, Minoru; Zheng, Guo-qing

    2015-02-01

    The relationship between charge-density wave (CDW) orders and superconductivity in arsenide superconductor SrPt2As2 with Tc=5.2 K which crystallizes in the CaBe2Ge2 -type structure was studied by 75As nuclear magnetic resonance (NMR) measurements up to 520 K, and 75As nuclear quadrupole resonance (NQR) and 195Pt-NMR measurements down to 1.5 K. At high temperature, 75As-NMR spectrum and nuclear-spin-relaxation rate (1 /T1) have revealed two distinct CDW orders, one realized in the As-Pt-As layer below TCDWAs (1 )=410 K and the other in the Pt-As-Pt layer below TCDWAs (2 )=255 K . The 1 /T1 measured by 75As-NQR shows a clear Hebel-Slichter peak just below Tc and decreases exponentially well below Tc. Concomitantly, 195Pt Knight shift decreases below Tc. Our results indicate that superconductivity in SrPt2As2 is in the spin-singlet state with an s -wave gap and is robust under the two distinct CDW orders in different layers.

  16. Volovik effect and Fermi-liquid behavior in the s -wave superconductor CaPd2As2: 75As NMR-NQR measurements

    NASA Astrophysics Data System (ADS)

    Ding, Q.-P.; Wiecki, P.; Anand, V. K.; Sangeetha, N. S.; Lee, Y.; Johnston, D. C.; Furukawa, Y.

    2016-04-01

    The electronic and magnetic properties of the collapsed-tetragonal CaPd2As2 superconductor (SC) with a transition temperature of 1.27 K have been investigated by 75As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements. The temperature (T ) dependence of the nuclear spin lattice relaxation rates (1 /T1) and the Knight shifts indicate the absence of magnetic correlations in the normal state. In the SC state, 1 /T1 measured by 75As NQR shows a clear Hebel-Slichter (HS) peak just below Tc and decreases exponentially at lower T , confirming a conventional s -wave SC. In addition, the Volovik effect, also known as the Doppler shift effect, has been clearly evidenced by the observation of the suppression of the HS peak with applied magnetic field.

  17. Indirect (J) coupling of inequivalent ^75As nuclei in crystalline and glassy As_2Se3 and As_2S_3

    NASA Astrophysics Data System (ADS)

    Whitaker, J.; Ahn, E.; Hart, P.; Williams, G. A.; Taylor, P. C.; Facelli, J. C.

    2004-03-01

    Indirect nuclear spin-spin couplings, or J couplings, were first observed in liquids using nuclear magnetic resonance (NMR) techniques [1]. Because of the nature of the quadrupole Hamiltonian in pure nuclear quadrupole resonance (NQR) experiments J couplings should be observable between inequivalent nuclei [2]. We present results of ^75As NQR measurements in crystalline and glassy As_2S3 and As_2Se_3. These ^75As NQR measurements were performed at various frequencies between about 55 and 75 MHz. The NQR frequency is determined by the electric field gradient (EFG) at the nucleus, and in these materials there are two non-equivalent sites in each of the two crystals. The J coupling can occur through several chemical bonds, and in our case this coupling must go through two As-S covalent bonds since the nearest neighbor As sites are separated by chalcogen atoms. Instead of the monotonic decay expected from relaxation spin-spin theory, the decays of the NQR Hahn echoes following a 90^0-180^0pulse sequence exhibit damped oscillations superimposed on an exponential decay. These damped oscillations can be explained by an indirect coupling (J coupling). Experimental values of the J couplings were obtained from the periods of the oscillations and calculations of the most probable transitions using 2^nd order perturbation theory. The value estimated by this method for the ^2J(^75As-S-^75As) in crystalline As_2S3 compares well with empirical estimates, which are obtained using an existing value of ^2J(^31P-S-^31P) and known scalings with atomic number from the literature. 1. E. L. Hahn and D. E Maxwell, Phys. Rev. 84, 1246 (1951). 2. T. P. Das and E. L. Hahn, Solid State Physics, supp 1, Nuclear Quadrupole Resonance Spectroscopy, p. 28, Academic Press 1958.

  18. Cracking phenomena in In{sub 0.25}Ga{sub 0.75}As films on InP substrates

    SciTech Connect

    Wu, X.; Weatherly, G.C.

    1999-09-29

    The strain relaxation of a series of In{sup 0.25}Ga{sub 0.75}As films grown on (100) InP substrates (lattice mismatch = 2%) has been studied by electron microscopy. The mechanisms of strain relief (in the first stages of growth) occurred by cracking on (0{bar 1}1), and by twinning on (111) and ({bar 1}11) planes. Cracking was a transitory process with the density of cracks being highest in a 20 nm thick film, while a 500 nm thick film was crack-free. These results are discussed in the context of different cracking and crack-healing models.

  19. Electronic and Magnetic Properties of Ba1-xKxMn2As2 Studied by 55Mn and 75As-NMR

    NASA Astrophysics Data System (ADS)

    Yeninas, S.; Pandey, A.; Johnston, D. C.; Furukawa, Y.

    2013-03-01

    BaMn2As2 (Mn2+; S = 5/2) is a G-type antiferromagnetic (AF) semiconductor with Néel temperature TN ~ 625 K and a small band gap of ~ 27 meV. Hole doping by substitution of Ba with K drives BaMn2As2 into a metallic state while maintaining the same AF spin structure with similar high TN. In order to investigate hole doping effects on electronic and magnetic properties in Ba1-xKxMn2As2from a microscopic point of view, we have conducted 55Mn and 75As-NMR spectra and spin-lattice relaxation measurements on single crystals of Ba1-xKxMn2As2 (x = 0, 0.04, 0.4). The temperature (T) dependence of 1/T1 for 55Mn and 75As for the x=0 compound shows 1/T1 ~T3 dependence for both nuclei, suggesting that 1/T1 of the nuclei arises from interactions with magnon excitations in the local-moment AF state. On the other hand, the 1/T1 of both nuclei is found to be proportional to T (Korringa relation) in K-doped materials below TN, which corresponds to the AF metallic state in Ba1-xKxMn2As2.

  20. 133Cs and 75As NMR investigation of the normal metallic state of quasi-one-dimensional Cs2Cr3As3

    NASA Astrophysics Data System (ADS)

    Zhi, Haizhao; Lee, Drake; Imai, Takashi; Tang, Zhangtu; Liu, Yi; Cao, Guanghan

    2016-05-01

    We report 133Cs NMR and 75As nuclear quadrupole resonance (NQR) measurements on the normal metallic state above Tc of a quasi-one-dimensional superconductor Cs2Cr3As3 (Tc<1.6 K). From the 133Cs NMR Knight shift 133K measured at the Cs1 site, we show that the uniform spin susceptibility χspin increases from 295 K to ˜60 K, followed by a mild suppression; χspin then levels off below ˜10 K. In contrast, a vanishingly small magnitude of 133K indicates that Cs2 sites contribute very little to electrical conduction and the exchange interactions between 3d electrons at Cr sites. Low frequency Cr spin dynamics, reflected on 75As1 /T1T (the nuclear spin-lattice relaxation rate 1 /T1 divided by temperature T ), shows an analogous trend as χspin. Comparison with the results of 1 /T1T near Tc with K2Cr3As3 (Tc=6.1 K) and Rb2Cr3As3 (Tc=4.8 K) establishes a systematic trend that substitution of K+ ions with larger alkali ions progressively suppresses Cr spin fluctuations together with Tc.

  1. Single photon emission of a charge-tunable GaAs/Al{sub 0.25}Ga{sub 0.75}As droplet quantum dot device

    SciTech Connect

    Langer, Fabian Plischke, David; Kamp, Martin; Höfling, Sven

    2014-08-25

    In this work, we report the fabrication of a charge-tunable GaAs/Al{sub 0.25}Ga{sub 0.75}As quantum dot (QD) device containing QDs deposited by modified droplet epitaxy producing almost strain and composition gradient free QDs. We obtained a QD density in the low 10{sup 9 }cm{sup −2} range that enables us to perform spectroscopy on single droplet QDs showing linewidths as narrow as 40 μeV. The integration of the QDs into a Schottky diode allows us to controllably charge a single QD with up to four electrons, while non-classical photoluminescence is proven by photon auto-correlation measurements showing photon-antibunching (g{sup (2)}(0) = 0.05).

  2. Investigation of the reaction 74Ge(p,γ)75As using the in-beam method to improve reaction network predictions for p nuclei

    NASA Astrophysics Data System (ADS)

    Sauerwein, A.; Endres, J.; Netterdon, L.; Zilges, A.; Foteinou, V.; Provatas, G.; Konstantinopoulos, T.; Axiotis, M.; Ashley, S. F.; Harissopulos, S.; Rauscher, T.

    2012-09-01

    Background: Astrophysical models studying the origin of the neutron-deficient p nuclides require knowledge of proton capture cross sections at low energy. The production site of the p nuclei is still under discussion but a firm basis of nuclear reaction rates is required to address the astrophysical uncertainties. Data at astrophysically relevant interaction energies are scarce. Problems with the prediction of charged particle capture cross sections at low energy were found in the comparisons between previous data and calculations in the Hauser-Feshbach statistical model of compound reactions.Purpose: A measurement of 74Ge(p,γ)75As at low proton energies, inside the astrophysically relevant energy region, is important in several respects. The reaction is directly important because it is a bottleneck in the reaction flow which produces the lightest p nucleus 74Se. It is also an important addition to the data set required to test reaction-rate predictions and to allow an improvement in the global p+nucleus optical potential required in such calculations.Method: An in-beam experiment was performed, making it possible to measure in the range 2.1≤Ep≤3.7MeV, which is for the most part inside the astrophysically relevant energy window. Angular distributions of the γ-ray transitions were measured with high-purity germanium detectors at eight angles relative to the beam axis. In addition to the total cross sections, partial cross sections for the direct population of 12 levels were determined.Results: The resulting cross sections were compared to Hauser-Feshbach calculations using the code smaragd. Only a constant renormalization factor of the calculated proton widths allowed a good reproduction of both total and partial cross sections. The accuracy of the calculation made it possible to check the spin assignment of some states in 75As. In the case of the 1075-keV state, a double state with spins and parities of 3/2- and 5/2- is needed to explain the experimental

  3. Antiferromagnetic spin correlations and pseudogaplike behavior in Ca(Fe1-xCox)2As2 studied by 75As nuclear magnetic resonance and anisotropic resistivity

    DOE PAGESBeta

    Cui, J.; Roy, B.; Tanatar, M. A.; Ran, S.; Bud'ko, S. L.; Prozorov, R.; Canfield, P. C.; Furukawa, Y.

    2015-11-06

    We report 75As nuclear magnetic resonance (NMR) measurements of single-crystalline Ca(Fe1–xCox)2As2 (x=0.023, 0.028, 0.033, and 0.059) annealed at 350°C for 7 days. From the observation of a characteristic shape of 75As NMR spectra in the stripe-type antiferromagnetic (AFM) state, as in the case of x=0 (TN=170 K), clear evidence for the commensurate AFM phase transition with the concomitant structural phase transition is observed in x=0.023 (TN=106 K) and x=0.028 (TN=53 K). Through the temperature dependence of the Knight shifts and the nuclear spin lattice relaxation rates (1/T1), although stripe-type AFM spin fluctuations are realized in the paramagnetic state as inmore » the case of other iron pnictide superconductors, we found a gradual decrease of the AFM spin fluctuations below a crossover temperature T* that was nearly independent of Co-substitution concentration, and it is attributed to a pseudogaplike behavior in the spin excitation spectra of these systems. The T* feature finds correlation with features in the temperature-dependent interplane resistivity, ρc(T), but not with the in-plane resistivity ρa(T). The temperature evolution of anisotropic stripe-type AFM spin fluctuations is tracked in the paramagnetic and pseudogap phases by the 1/T1 data measured under magnetic fields parallel and perpendicular to the c axis. As a result, based on our NMR data, we have added a pseudogaplike phase to the magnetic and electronic phase diagram of Ca(Fe1–xCox)2As2.« less

  4. Antiferromagnetic spin correlations and pseudogaplike behavior in Ca (Fe1-xCox) 2As2 studied by 75As nuclear magnetic resonance and anisotropic resistivity

    NASA Astrophysics Data System (ADS)

    Cui, J.; Roy, B.; Tanatar, M. A.; Ran, S.; Bud'ko, S. L.; Prozorov, R.; Canfield, P. C.; Furukawa, Y.

    2015-11-01

    We report 75As nuclear magnetic resonance (NMR) measurements of single-crystalline Ca (Fe1-xCox) 2As2 (x =0.023 , 0.028, 0.033, and 0.059) annealed at 350 °C for 7 days. From the observation of a characteristic shape of 75As NMR spectra in the stripe-type antiferromagnetic (AFM) state, as in the case of x =0 (TN=170 K), clear evidence for the commensurate AFM phase transition with the concomitant structural phase transition is observed in x =0.023 (TN=106 K) and x =0.028 (TN=53 K). Through the temperature dependence of the Knight shifts and the nuclear spin lattice relaxation rates (1 /T1 ), although stripe-type AFM spin fluctuations are realized in the paramagnetic state as in the case of other iron pnictide superconductors, we found a gradual decrease of the AFM spin fluctuations below a crossover temperature T* that was nearly independent of Co-substitution concentration, and it is attributed to a pseudogaplike behavior in the spin excitation spectra of these systems. The T* feature finds correlation with features in the temperature-dependent interplane resistivity, ρc(T ) , but not with the in-plane resistivity ρa(T ) . The temperature evolution of anisotropic stripe-type AFM spin fluctuations is tracked in the paramagnetic and pseudogap phases by the 1 /T1 data measured under magnetic fields parallel and perpendicular to the c axis. Based on our NMR data, we have added a pseudogaplike phase to the magnetic and electronic phase diagram of Ca (Fe1-xCox) 2As2 .

  5. Coexistence of antiferromagnetic and ferromagnetic spin correlations in SrCo2As2 revealed by 59Co and 75As NMR

    DOE PAGESBeta

    Wiecki, P.; Ogloblichev, V.; Pandey, Abhishek; Johnston, D. C.; Furukawa, Y.

    2015-06-15

    In nonsuperconducting, metallic paramagnetic SrCo2As2, inelastic neutron scattering measurements have revealed strong stripe-type q=(π,0) antiferromagnetic (AFM) spin correlations. Using nuclear magnetic resonance (NMR) measurements on 59Co and 75As nuclei, we demonstrate that stronger ferromagnetic (FM) spin correlations coexist in SrCo2As2. Our NMR data are consistent with density functional theory (DFT) calculations which show enhancements at both q=(π,0) and the in-plane FM q=0 wave vectors in static magnetic susceptibility χ(q). We suggest that the strong FM fluctuations prevent superconductivity in SrCo2As2, despite the presence of stripe-type AFM fluctuations. Since DFT calculations have consistently revealed similar enhancements of the χ(q) at bothmore » q=(π,0) and q=0 in the iron-based superconductors and parent compounds, our observation of FM correlations in SrCo2As2 calls for detailed studies of FM correlations in the iron-based superconductors.« less

  6. Metal-insulator transition in antiferromagnetic Ba1−xKxMn2As2 (0≤x≤0.4) single crystals studied by 55Mn and 75As NMR

    SciTech Connect

    Yeninas, Steven; Pandey, Abhishek; Ogloblichev, V.; Mikhalev, K.; Johnston, David C.; Furukawa, Yuji

    2013-12-23

    The magnetic structure and metal-insulator transition in antiferromagnetic (AFM) BaMn2As2 and Ba1−xKxMn2As2 single crystals have been investigated by 55Mn and 75As nuclear magnetic resonance (NMR) measurements. In the parent AFM insulator BaMn2As2 with a Néel temperature TN=625 K, we observed a 55Mn zero-field NMR (ZFNMR) spectrum and confirmed the G-type AFM structure from the field dependence of the 55Mn spectra and 75As NMR spectra below TN. In hole-doped crystals with x>0.01, similar 55Mn ZFNMR spectra were observed and the AFM state was revealed to be robust up to x=0.4 with the ordered moment nearly independent of x. The nuclear spin-lattice relaxation rates (1/T1) for both nuclei in the doped samples follow the Korringa relation T1T=const, indicating a metallic state. This confirms the coexistence of AFM ordered localized Mn spins and conduction carriers from a microscopic point of view. From the x dependence of (T1T)−1/2 for both nuclei, we conclude that this transition is caused by vanishing of the hole concentration as the transition is approached from the metallic side.

  7. (121,123)Sb and (75)As NMR and NQR investigation of the tetrahedrite (Cu12Sb4S13)--Tennantite (Cu12As4S13) system and other metal arsenides.

    PubMed

    Bastow, T J; Lehmann-Horn, J A; Miljak, D G

    2015-10-01

    This work is motivated by the recent developments in online minerals analysis in the mining and minerals processing industry via nuclear quadrupole resonance (NQR). Here we describe a nuclear magnetic resonance (NMR) and NQR study of the minerals tennantite (Cu12As4S13) and tetrahedrite (Cu12 Sb4S13). In the first part NQR lines associated with (75)As in tennantite and (121,123)Sb isotopes in tetrahedrite are reported. The spectroscopy has been restricted to an ambient temperature studies in accord with typical industrial conditions. The second part of this contribution reports nuclear quadrupole-perturbed NMR findings on further, only partially characterised, metal arsenides. The findings enhance the detection capabilities of NQR based analysers for online measurement applications and may aid to control arsenic and antimony concentrations in metal processing stages. PMID:26453410

  8. Potential Antiferromagnetic Fluctuations in Hole-Doped Iron-Pnictide Superconductor Ba1-xKxFe2As2 Studied by 75As Nuclear Magnetic Resonance Measurement0.1143/JPSJ.81.054704

    SciTech Connect

    Hirano, Masanori; Yamada, Yuji; Saito, Taku; Nagashima, Ryo; Konishi, Takehisa; Toriyama, Tatsuya; Ohta, Yukinori; Fukazawa, Hideto; Kohori, Yoh; Furukawa, Yuji; Kihou, Kunihiro; Lee, Chul-Ho; Eisaki, Hiroshi

    2012-04-12

    We have performed 75As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements on single-crystalline Ba1-xKxFe2As2 for x = 0.27–1. 75As nuclear quadruple resonance frequency (νQ) increases linearly with increasing x. The Knight shift K in the normal state shows Pauli paramagnetic behavior with a weak temperature T dependence. K increases gradually with increasing x. By contrast, the nuclear spin–lattice relaxation rate 1/T1 in the normal state has a strong T dependence, which indicates the existence of large antiferomagnetic (AF) spin fluctuations for all x's. The T dependence of 1/T1 shows a gaplike behavior below approximately 100 K for 0.6 < x < 0.9. This behaviors is well explained by the change in the band structure with the expansion of hole Fermi surfaces and the shrinkage and disappearance of electron Fermi surfaces at the Brillouin zone (BZ) with increasing x. The anisotropy of 1/T1, represented by the ratio of 1/T1ab to 1/T1c, is always larger than 1 for all x's, which indicates that stripe-type AF fluctuations are dominant in this system. The K in the superconducting (SC) state decreases, which corresponds to the appearance of spin-singlet superconductivity. The T dependence of 1/T1 in the SC state indicates a multiple-SC-gap feature. A simple two-gap model analysis shows that the larger superconducting gap gradually decreases with increasing x from 0.27 to 1 and a smaller gap decreases rapidly and nearly vanishes for x > 0.6 where electron pockets in BZ disappear.

  9. Interplay between Fe 3d and Ce 4f magnetism and Kondo interaction in CeFeAs(1-x)P(x)O probed by 75As and 31P NMR.

    PubMed

    Sarkar, R; Baenitz, M; Jesche, A; Geibel, C; Steglich, F

    2012-04-01

    A detailed (31)P (I = 1/2) and (75)As (I = 3/2) NMR study on polycrystalline CeFeAs(1-x)P(x)O alloys is presented. The magnetism of CeFeAsO changes drastically upon P substitution on the As site. CeFePO is a heavy fermion system without long-range order whereas CeFeAsO exhibits an Fe 3d SDW type of ordering accompanied by a structural transition from tetragonal (TT) to orthorhombic (OT) structure. Furthermore, Ce 4f(1) orders antiferromagnetically (AFM) at low temperature. At the critical concentration where the Fe magnetism is diminished the Ce-Ce interaction changes to a ferromagnetic (FM) type of ordering. Three representative samples of the CeFeAs(1-x)P(x)O (x = 0.05, 0.3 and 0.9) series are systematically investigated. (1) For the x = 0.05 alloy a drastic change of the linewidth at 130 K indicates the AFM-SDW type of ordering of Fe and the structural change from the TT to the OT phase. The linewidth roughly measures the internal field in the ordered state and the transition is most likely first order. The small and nearly constant shift from (31)P and (75)As NMR suggests the presence of competing hyperfine interactions between the nuclear spins and the 4f and 3d ions of Ce and Fe. (2) For the x = 0.3 alloy, the evolution of the Fe-SDW type of order takes place at around 70 K corroborating the results of bulk measurement and μSR. Here we found evidence for phase separation of paramagnetic and magnetic SDW phases. (3) In contrast to the heavy fermion CeFePO for the x = 0.9 alloy a phase transition is found at 2 K. The field-dependent NMR shift gives evidence of FM ordering. Above the ordering the spin-lattice relaxation rate (31)(1/T(1)) shows unconventional, non-Korringa-like behaviour which indicates a complex interplay of Kondo and FM fluctuations. PMID:22407024

  10. Erratum: Radiative strength functions in Dy163,164 [Phys. Rev. C 81, 024325 (2010)

    NASA Astrophysics Data System (ADS)

    Nyhus, H. T.; Siem, S.; Guttormsen, M.; Larsen, A. C.; Bürger, A.; Syed, N. U. H.; Tveten, G. M.; Voinov, A.

    2010-08-01

    The nuclei 163,164Dy have been investigated using the Oslo method on data from the pick-up reaction 164Dy(3He,alpha gamma)163Dy and the inelastic scattering 164Dy(3He,3He' gamma)164Dy, respectively. The radiative strength functions for both nuclei have been extracted, and a small resonance centered around Eg ?3 MeV is observed in both cases. The parameters of this so-called pygmy M1 resonance (the scissors mode) are compared to previous results on 160,161,162Dy using the Oslo method, and to data on 163Dy measured by the Prague group using the two-step cascade method. In particular, the integrated reduced transition probability B(M1) of the pygmy resonance is compared with neighboring dysprosium isotopes. We also observe an enhanced strength in the region above gamma energy around 5 MeV in 164Dy. Possible origins of this feature are discussed.

  11. Droplet formation in a Bose-Einstein condensate with strong dipole-dipole interaction

    NASA Astrophysics Data System (ADS)

    Xi, Kui-Tian; Saito, Hiroki

    2016-01-01

    Motivated by the recent experiment [H. Kadau et al., arXiv:1508.05007], we study roton instability and droplet formation in a Bose-Einstein condensate of 164Dy atoms with strong magnetic dipole-dipole interaction. We numerically solve the cubic-quintic Gross-Pitaevskii equation with dipole-dipole interaction, and show that the three-body interaction plays a significant role in the formation of droplet patterns. We numerically demonstrate the formation of droplet patterns and crystalline structures, decay of droplets, and hysteresis behavior, which are in good agreement with the experiment. Our numerical simulations provide the first prediction on the values of the three-body interaction in a 164Dy Bose-Einstein condensate. We also predict that the droplets remain stable during the time-of-flight expansion. From our results, further experiments investigating the three-body interaction in dipolar quantum gases are required.

  12. Separation of carrier-free holmium-166 from neutron-irradiated dysprosium targets

    SciTech Connect

    Dadachova, E.; Lambrecht, R.M.; Hetherington, E.L. ); Mirzadeh, S.; Knapp, F.F. Jr. )

    1994-12-01

    Holmium-166 ([sup 166]Ho, t[sub 1/2] = 26.4 h) is utilized in radiotherapeutic applications such as radioimmunospecific pharmaceuticals, bone marrow ablation, and radiation synovectomy. High specific activity [sup 166]Ho can be obtained from the decay of dysprosium-166 ([sup 166]Dy, t[sub 1/2] = 81.5 h). Dysprosium-166 is produced by the [sup 164]Dy[n,[gamma

  13. Detection of an unconventional superconducting phase in the vicinity of the strong first-order magnetic transition in CrAs using (75)As-nuclear quadrupole resonance.

    PubMed

    Kotegawa, Hisashi; Nakahara, Shingo; Akamatsu, Rui; Tou, Hideki; Sugawara, Hitoshi; Harima, Hisatomo

    2015-03-20

    Pressure-induced superconductivity was recently discovered in the binary helimagnet CrAs. We report the results of measurements of nuclear quadrupole resonance for CrAs under pressure. In the vicinity of the critical pressure P(c) between the helimagnetic (HM) and paramagnetic (PM) phases, a phase separation is observed. The large internal field remaining in the phase-separated HM state indicates that the HM phase disappears through a strong first-order transition. This indicates the absence of a quantum critical point in CrAs; however, the nuclear spin-lattice relaxation rate 1/T(1) reveals that substantial magnetic fluctuations are present in the PM state. The absence of a coherence effect in 1/T(1) in the superconducting state provides evidence that CrAs is the first Cr-based unconventional superconductor. PMID:25839303

  14. Investigation of ac Stark shifts in excited states of dysprosium relevant to testing fundamental symmetries

    NASA Astrophysics Data System (ADS)

    Weber, C. T. M.; Leefer, N.; Budker, D.

    2013-12-01

    We report on measurements of the differential polarizability between the nearly degenerate, opposite parity states in atomic dysprosium at 19 797.96 cm-1, and the differential blackbody radiation induced Stark shift of these states. The differential scalar and tensor polarizabilities due to additional states were measured for the |M|=7,⋯,10 sublevels in 164Dy and 162Dy and determined to be α¯BA(0)=180(45)stat(8)sys mHz/(V/cm)2 and α¯BA(2)=-163(65)stat(5)sys mHz/(V/cm)2, respectively. The average blackbody radiation induced Stark shift of the Zeeman spectrum was measured around 300 K and found to be -34(4) mHz/K and +29(4) mHz/K for 164Dy and 162Dy, respectively. We conclude that ac Stark related systematics will not limit a search for variation of the fine-structure constant, using dysprosium, down to the level of |α˙/α|=2.6×10-17 yr-1, for two measurements of the transition frequency one year apart.

  15. Surrogate ratio methodology for the indirect determination of neutron capture cross sections

    SciTech Connect

    Goldblum, B. L.; Prussin, S. G.; Bernstein, L. A.; Younes, W.; Guttormsen, M.; Nyhus, H. T.

    2010-05-15

    The relative gamma-decay probabilities of the {sup 162}Dy to {sup 161}Dy and {sup 162}Dy to {sup 164}Dy residual nuclei, produced using light-ion-induced direct reactions, were measured as a function of excitation energy using the CACTUS array at the Oslo Cyclotron Laboratory. The external surrogate ratio method (SRM) was used to convert these relative gamma-decay probabilities into the {sup 161}Dy(n,gamma) cross section in an equivalent neutron energy range of 130-560 keV. The directly measured {sup 161}Dy(n,gamma) cross section, obtained from the Evaluated Nuclear Data Files (ENDF/B-VII.0), was compared to the experimentally determined surrogate {sup 161}Dy(n,gamma) cross section obtained using compound-nucleus pairs with both similar ({sup 162}Dy to {sup 164}Dy) and dissimilar ({sup 162}Dy to {sup 161}Dy) nuclear structures. A gamma-ray energy threshold was identified, based upon pairing gap parameters, that provides a first-order correction to the statistical gamma-ray tagging approach and improves the agreement between the surrogate cross-section data and the evaluated result.

  16. Correlation of ibuprofen bioavailability with gastrointestinal transit by scintigraphic monitoring of /sup 171/Er-labeled sustained-release tablets

    SciTech Connect

    Parr, A.F.; Beihn, R.M.; Franz, R.M.; Szpunar, G.J.; Jay, M.

    1987-12-01

    External gamma scintigraphy was used to monitor the gastrointestinal (GI) transit of radiolabeled sustained-release tablets containing 800 mg ibuprofen in eight fasted healthy volunteers. Ibuprofen serum concentrations were determined from blood samples drawn sequentially over a 24-hr period. Serum concentrations and related parameters were correlated to the position of the dosage form in the GI tract from the scintiphotos. The sustained-release tablets were radiolabeled intact utilizing a neutron activation procedure, by incorporating 0.18% of /sup 170/Er2O3 (enriched to greater than 96% /sup 170/Er) into the bulk formulation. After manufacture of the final dosage forms, the tablets were irradiated in a neutron flux (4.4 x 10(13) n/cm2.sec) for 2 min, converting the stable /sup 170/Er to radioactive /sup 171/Er (t1/2 = 7.5 hr). Each tablet contained 50 microCi of /sup 171/Er at the time of administration. The scintigraphy studies suggested that the greatest proportion of ibuprofen was absorbed from this dosage form while the tablet was in the large bowel. The dosage forms eroded slowly in the small bowel and appeared to lose their integrity in the large bowel. In vitro studies showed only minimal effects of the neutron irradiation procedure on the dosage form performance.

  17. The effect of food on gastrointestinal (GI) transit of sustained-release ibuprofen tablets as evaluated by gamma scintigraphy

    SciTech Connect

    Borin, M.T.; Khare, S.; Beihn, R.M.; Jay, M. )

    1990-03-01

    The GI transit of radiolabeled sustained-release ibuprofen 800-mg tablets in eight healthy, fed volunteers was monitored using external gamma scintigraphy. Ibuprofen serum concentrations were determined from blood samples drawn over 36 hr following dosing. Sustained-release ibuprofen tablets containing 0.18% of 170Er2O3 (greater than 96% 170Er) in the bulk formulation were manufactured under pilot-scale conditions and were radiolabeled utilizing a neutron activation procedure which converted stable 170Er to radioactive 171Er (t1/2 = 7.5 hr). At the time of dosing, each tablet contained 50 mu Ci of 171Er. Dosage form position were reported at various time intervals. In five subjects the sustained-release tablet remained in the stomach and eroded slowly over 7-12 hr, resulting in gradual increases in small bowel radioactivity. In the remaining three subjects, the intact tablet was ejected from the stomach and a gastric residence time of approximately 4 hr was measured. This is in marked contrast to a previous study conducted in fasted volunteers in which gastric retention time ranged from 10 to 60 min. Differences in GI transit between fed and fasted volunteers had little effect on ibuprofen bioavailability. AUC and Tmax were unaltered and Cmax was increased by 24%, which is in agreement with results from a previous, crossover-design food effect study.

  18. Changes of charge radii and hyperfine interactions of the Dy isotopes

    NASA Astrophysics Data System (ADS)

    Clark, D. L.; Greenlees, G. W.

    1982-10-01

    A continuous wave dye laser and a thermal atomic beam were used to measure the optical isotope shifts and hyperfine splittings for the 5547 Å, 5639 Å, 5652 Å, 5974 Å, and the 5989 Å transition of the seven stable isotopes of dysprosium. The hyperfine splitting of the odd-A isotopes has been analyzed using the formalism of Sanders and Beck and the hyperfine anomaly has been extracted. Comparison with calculations using Nilsson wave functions is presented. The isotope shift measurements have been analyzed with published electronic and muonic x-ray isotope shifts to yield δ values and some estimates of the specific mass shift constant. NUCLEAR STRUCTURE 156-164Dy. Measured optical isotope shifts and hyperfine splittings. Deduced δ, A(4f126s 6p), B(4f126s 6p), and the hyperfine anomaly. Laser spectroscopy on atomic beams.

  19. Two-dimensional bright and dark-in-bright dipolar Bose–Einstein condensate solitons on a one-dimensional optical lattice

    NASA Astrophysics Data System (ADS)

    Adhikari, S. K.

    2016-08-01

    We study the statics and dynamics of anisotropic, stable, bright and dark-in-bright dipolar quasi-two-dimensional Bose–Einstein condensate (BEC) solitons on a one-dimensional (1D) optical-lattice (OL) potential. These solitons mobile in a plane perpendicular to a 1D OL trap can have both repulsive and attractive contact interactions. Dark-in-bright solitons are the excited states of bright solitons. The solitons, when subjected to a small perturbation, exhibit sustained breathing oscillation. Dark-in-bright solitons can be created by phase imprinting a bright soliton. At medium velocities the collision between two solitons is found to be quasi-elastic. Results are demonstrated by a numerical simulation of the three-dimensional mean-field Gross–Pitaevskii equation in three spatial dimensions employing realistic interaction parameters for a dipolar 164Dy BEC.

  20. Mass tensor in the Bohr Hamiltonian from the nondiagonal energy weighted sum rules

    SciTech Connect

    Jolos, R. V.; Brentano, P. von

    2009-04-15

    Relations are derived in the framework of the Bohr Hamiltonian that express the matrix elements of the deformation-dependent components of the mass tensor through the experimental data on the energies and the E2 transitions relating the low-lying collective states. These relations extend the previously obtained results for the intrinsic mass coefficients of the well-deformed axially symmetric nuclei on nuclei of arbitrary shape. The expression for the mass tensor is suggested, which is sufficient to satisfy the existing experimental data on the energy weighted sum rules for the E2 transitions for the low-lying collective quadrupole excitations. The mass tensor is determined for {sup 106,108}Pd, {sup 108-112}Cd, {sup 134}Ba, {sup 150}Nd, {sup 150-154}Sm, {sup 154-160}Gd, {sup 164}Dy, {sup 172}Yb, {sup 178}Hf, {sup 188-192}Os, and {sup 194-196}Pt.

  1. Nuclear research with heavy ions. Annual progress report. January 1, 1980-December 31, 1980

    SciTech Connect

    Kaplan, M.

    1980-10-01

    The program of research is oriented towards experimental studies of the interactions between heavy ions and complex nuclei. These interactions are probed by detailed measurements of light-charged-particle emission using counter telescopes for atomic number and mass number identification. Singles measurements of the charged-particle energy spectra and angular distributions, together with coincidence correlations with heavy nuclear-reaction fragments, provide insight into the contributing reaction mechanisms. The application of the statistical model to the appropriate experimental data allows the determination of parameters necessary to calibrate the theory, and gives indications of dynamical control vs. equilibrium in the several degrees of freedom associated with the nuclear collisions. A large body of data are presented and discussed for /sup 40/Ar reactions with /sup 116/Sn, /sup 154/Sm, /sup 164/Dy, and /sup 197/Au targets. Complete results are also given for twelve reactions which produce /sup 194/Hg compound nuclei at several excitation energies.

  2. Ultracold Dysprosium Gas

    NASA Astrophysics Data System (ADS)

    Bouazza, Chayma; Bose-Einstein Condensate Team

    2016-05-01

    Ultracold quantum gases with long-rang and anisotropic interactions open the door to new possibilities for exploring correlated many-body systems. The advantage of using ultracold atoms in order to realize such systems relies on the high level of control and manipulation offered by this field. Recent progress in trapping and cooling some Lanthanide atoms with a strong magnetic moment such as Erbium or Dysprosium present an important tool to investigate the dipole-dipole interaction. In particular the dysprosium atom has multiple features that make it an interesting candidate to study such systems. It has the largest magnetic moment among all atoms (10μB) and a rich energy level structure which allows the implementation of different cooling schemes. In my talk I will present our experiment with the bosonic isotope 164 Dy. I will set forth the interesting features of Dysprosium and explain the difference with alkali systems. UQUAM

  3. Decay of the neutron-rich isotope sup 171 Ho and the identification of sup 169 Dy

    SciTech Connect

    Chasteler, R.M.; Nitschke, J.M.; Firestone, R.B.; Vierinen, K.S.; Wilmarth, P.A. )

    1990-10-01

    Neutron-rich rare-earth isotopes were produced in multinucleon transfer reactions between {sup 170}Er ions and {sup nat}W targets. On-line mass separation was used together with {beta}- and {gamma}-ray spectroscopy in these studies. At mass {ital A}=169, the heaviest known dysprosium isotope, 39(8) s,{sup 169}Dy, was identified. It was observed to {beta}{sup {minus}} decay to the ground state of {sup 169}Ho or through a level at 1578 keV. In the {ital A}=171 mass chain, a partial decay scheme for 55(3)-s {sup 171}Ho was determined.

  4. Sub-barrier backward quasielastic scattering: A probe of the hexadecapole deformation

    NASA Astrophysics Data System (ADS)

    Zhang, H. Q.; Lin, C. J.; Jia, H. M.; Yang, L.; Xu, X. X.; Yang, F.; Wu, Z. D.; Liu, Z. H.; Ma, N. R.; Sun, L. J.; Wang, D. X.

    2016-05-01

    The quasielastic scattering excitation functions for 16O + 152Sm,170Er and 174Yb were measured with high precision at a backward angle with small energy intervals at energies near the Coulomb barriers. The hexadecapole deformation (β4) of the target nuclei was extracted by using the lower-energy data and the obtained values agree with the available results reasonably well. This offers a sensitive method to extract β4. This method is especially meaningful for the radioactive nuclei considering the low beam intensities.

  5. Decay of the neutron-rich isotope 171Ho and the identification of 169Dy

    NASA Astrophysics Data System (ADS)

    Chasteler, R. M.; Nitschke, J. M.; Firestone, R. B.; Vierinen, K. S.; Wilmarth, P. A.

    1990-10-01

    Neutron-rich rare-earth isotopes were produced in multinucleon transfer reactions between 170Er ions and natW targets. On-line mass separation was used together with β- and γ-ray spectroscopy in these studies. At mass A=169, the heaviest known dysprosium isotope, 39(8) s,169Dy, was identified. It was observed to β- decay to the ground state of 169Ho or through a level at 1578 keV. In the A=171 mass chain, a partial decay scheme for 55(3)-s 171Ho was determined.

  6. Search for variation of the fine-structure constant and violation of Lorentz symmetry using atomic dysprosium

    NASA Astrophysics Data System (ADS)

    Leefer, Nathan Alexander

    We report on the spectroscopy of radio-frequency transitions between nearly-degenerate, opposite-parity excited states in atomic dysprosium (Dy). Theoretical calculations predict that these states are very sensitive to variation of the fine-structure constant, alpha, owing to large relativistic corrections of opposite sign for the opposite-parity levels. The near degeneracy reduces the relative precision necessary to place constraints on variation of alpha competitive with results obtained from the best atomic clocks in the world. Additionally, the existence of several abundant isotopes of Dy allows isotopic comparisons that suppress common-mode systematic errors. The frequencies of the 754-MHz transition in 164Dy and 235-MHz transition in 162Dy were measured over the span of two years. Linear variation of alpha is found to be ȧ/alpha = (--5.8 +/- 6.9) x 10--17 yr--1 , consistent with zero. The same data are used to constrain the dimensionless parameter kalpha, characterizing a possible coupling of alpha to a changing gravitational potential. We find that kalpha = (--5.5 +/- 5.2) x 10--7, essentially consistent with zero and the best constraint to date. The same data are used to report a joint test of local Lorentzinvarianceand the Einstein Equivalence Principle for electrons. We present many-body calculations which demonstrate that the energy splitting of these states is particularly sensitive to violations of both special and general relativity. Lorentz violation for electrons is limited at the level of 10--17 , matching or improving the best laboratory and astrophysical limits by up to a factor of 10, and gravitational redshift anomalies for electrons to the level of 10--8. With some enhancements, our experiment may be sensitive to Lorentz violation at the level of 9 x 10 --20. We also report measurements of the differential polarizabilitybetween the nearly degenerate, opposite parity states. The differential scalar and tensor polarizabilities due to additional

  7. Effect of entrance channel on dynamics of heavy ions collision

    NASA Astrophysics Data System (ADS)

    Naderi, D.

    2016-01-01

    A combined dynamical model using concept of dinuclear systems (DNS) and one-dimensional (1D) Langevin equations was applied to investigate the effect of entrance channel on dynamics of heavy ions collision. The 30Si+170Er, 16O+184W and 19F+181Ta reactions which formed the compound nucleus 200Pb have been considered to study this effect. We studied these reactions dynamically and calculated the ratio of evaporation residue cross-section to fusion cross-section (σER/σFus) as a tool for investigation of entrance channel effect. Results of combined model are compared with available experimental data and results of 1D Langevin equations. Obtained results based on combined model are in better agreement with experimental data in comparison with results of Langevin equations. We concluded for 30Si+170Er and 19F+181Ta reactions the results of combined model that support the quasi-fission process are different relative to Langevin dynamical approach, whereas for 16O+184W system the two models give similar results.

  8. Revised evaluations of fission-product cross sections

    SciTech Connect

    Wright, R.Q.

    1998-08-01

    This paper reports on revised cross-section evaluations for {sup 134}Ba, {sup 149}Sm, {sup 154}Eu, {sup 155}Eu, {sup 160}Dy, {sup 161}Dy, {sup 162}Dy, {sup 163}Dy, and {sup 164}Dy. The evaluations for {sup 134}Ba, {sup 154}Eu, and {sup 1554}Eu were previously revised for ENDF/B-VI. The other 6 evaluations, carried over from ENDF/B-V, were completed in the 1974--1980 time period. The evaluations for the dysprosium isotopes go back to ENDF/B-IV. Newer experimental data, not considered for the current ENDF/B-VI evaluations, was used in all of the revised evaluations. In the present work the primary emphasis was placed on the resolved and unresolved resonance regions, but newer measured data were also used for energies above the unresolved resonance region. Elastic, capture, and total cross sections are revised. Some important parameters from the revised evaluations are given in Table 1; corresponding values from the ENDF/B-VI evaluations are also given.

  9. Transition states and thermal collapse of dipolar Bose-Einstein condensates

    NASA Astrophysics Data System (ADS)

    Junginger, Andrej; Kreibich, Manuel; Main, Jörg; Wunner, Günter

    2013-10-01

    We investigate thermally excited, dipolar Bose-Einstein condensates (BECs). Quasiparticle excitations of the atomic cloud cause density fluctuations which can induce the collapse of the condensate if the interparticle interaction is attractive. Within a variational approach, we identify the collectively excited stationary states of the gas which form transition states on the way to the BEC's collapse. We analyze transition states with different m-fold rotational symmetry and identify the one which mediates the collapse. The latter's symmetry depends on the trap aspect ratio of the external trapping potential, which determines the shape of the BEC. Moreover, we present the collapse dynamics of the BEC and calculate the corresponding decay rate using transition-state theory. We observe that the thermally induced collapse mechanism is important near the critical scattering length, where the lifetime of the condensate can be significantly reduced. Our results are valid for an arbitrary strength of the dipole-dipole interaction. Specific applications are discussed for the elements 52Cr, 164Dy, and 168Er with which dipolar BECs have been experimentally realized.

  10. New limits on variation of the fine-structure constant using atomic dysprosium.

    PubMed

    Leefer, N; Weber, C T M; Cingöz, A; Torgerson, J R; Budker, D

    2013-08-01

    We report on the spectroscopy of radio-frequency transitions between nearly degenerate, opposite-parity excited states in atomic dysprosium (Dy). Theoretical calculations predict that these states are very sensitive to variation of the fine-structure constant α owing to large relativistic corrections of opposite sign for the opposite-parity levels. The near degeneracy reduces the relative precision necessary to place constraints on variation of α, competitive with results obtained from the best atomic clocks in the world. Additionally, the existence of several abundant isotopes of Dy allows isotopic comparisons that suppress common-mode systematic errors. The frequencies of the 754-MHz transition in 164Dy and 235-MHz transition in 162Dy are measured over the span of two years. The linear variation of α is α·/α=(-5.8±6.9([1σ]))×10(-17)  yr(-1), consistent with zero. The same data are used to constrain the dimensionless parameter kα characterizing a possible coupling of α to a changing gravitational potential. We find that kα=(-5.5±5.2([1σ]))×10(-7), essentially consistent with zero and the best constraint to date. PMID:23971546

  11. Total and Capture Cross Sections of Dysprosium Isotopes up to 20 MeV

    SciTech Connect

    Lee, Y.D.; Oh, S.Y.; Chang, J.H.

    2005-11-15

    Neutron data for total and capture cross sections were evaluated on {sup 160}Dy, {sup 161}Dy, {sup 162}Dy, {sup 163}Dy, and {sup 164}Dy up to 20 MeV. The resolved resonance parameters were adopted from the Mughabghab compilation, but one bound level resonance for each isotope except {sup 162}Dy was invoked to reproduce the reference thermal cross sections. The average resonance parameters for s-wave neutrons were obtained from the analysis of the statistical behavior of resolved resonance parameters. Recent measurements of the capture cross sections were taken into account in adjusting the average resonance parameters for p- and d-waves. From the first excited energy to 20 MeV, the optical model, Hauser-Feshbach model, and quantum mechanical models were used to produce total, elastic scattering, and capture cross sections. The energy-dependent optical model potential was decided based on the recent experimental data. The calculated cross sections were in good agreement with the experimental data. The present evaluation resulted in improvement over the ENDF/B-VI.7 code.

  12. Level density and thermodynamic properties of dysprosium isotopes

    NASA Astrophysics Data System (ADS)

    Nyhus, H. T.; Siem, S.; Guttormsen, M.; Larsen, A. C.; Bürger, A.; Syed, N. U. H.; Toft, H. K.; Tveten, G. M.; Voinov, A.

    2012-01-01

    163,164Dy nuclei have been measured by use of the Oslo method on data from pick-up (3He,α) and inelastic scattering (3He,3He') reactions, respectively. The level densities for these dysprosium isotopes together with previously measured 160-162Dy are extracted in the region below the neutron binding energy. Thermodynamic properties are deduced within both micro-canonical and canonical ensemble theories. A phase transition from the pair-correlated state at low energies to a less correlated or uncorrelated state is studied in both ensembles. It is investigated whether the temperature of the nucleus is constant or a varying function of excitation energy. It is found that above an excitation energy of 3 MeV the temperature of all five dysprosium nuclei have a constant value within the experimental uncertainties. The impact of a constant-temperature level density versus a Fermi gas level density is discussed with respect to the canonical heat capacity.

  13. Post-separation detection of nucleic acids and proteins by neutron activation.

    PubMed Central

    Snapka, R M; Kwok, K; Bernard, J A; Harling, O K; Varshavsky, A

    1986-01-01

    We describe approaches to neutron activation analysis and their application to post-separation autoradiographic detection of biological compounds. Specifically, we have extended the use of a "direct-labeling" method to the post-separation detection of DNA after gel electrophoresis and to the detection of nucleotides separated by TLC. In addition, we describe a more generally applicable "indirect-labeling" method in which separated compounds of interest are selectively bound to ligands containing highly neutron-activatable elements, such as manganese (55Mn), europium (151Eu), or dysprosium (164Dy), and then irradiated with thermal neutrons. This method is illustrated with nucleotides separated by TLC and with proteins separated by polyacrylamide gel electrophoresis. In contrast to the direct-labeling approach, the indirect-labeling method can be adapted to detect any class of substances for which a highly neutron-activatable, selectively binding ligand is available. The theoretically achievable sensitivity of the indirect-labeling method is in the attomole (10(-18) mol) range. Images PMID:3466168

  14. Commissioning of the DIAMANT 'Chessboard' Light-Charged-Particle CsI Detector Array with AFRODITE

    SciTech Connect

    Komati, F.S.; Bark, R.A.; Gueorguieva, E.; Lawrie, J.J.; Mullins, S.M.; Murray, S.H.T.; Sharpey-Schafer, J.F.; Gal, J.; Kalinka, G.; Krasznahorkay, A.; Molnar, J.; Nyako, B.M.; Timar, J.; Zolnai, L.; Juhasz, K.; Lipoglavsek, M.; Maliage, M.; Ramashidza, M.; Vymers, P.; Scheurer, J. N.

    2005-11-21

    In a commissioning measurement, the 'Chessboard' section of the DIAMANT charged-particle array has been coupled with the AFRODITE {gamma}-ray spectrometer at the iThemba Laboratory for Accelerator Based Sciences. Two data-sets were obtained following the bombardment of a 170Er target with a 13C beam at energies of 80 and 70 MeV, respectively. Offline analysis has thus far enabled the extension of a number of rotational bands associated with high-K intrinsic states in 176Hf. Also, the A = 172, 173 and 174 stable isotopes of ytterbium were populated via 2{alpha}xn channels with strengths of {approx}30-to-40% of the {alpha}xn yields. This, together with the comparative weakness of the pxn channels, is consistent with incomplete fusion as the dominant reaction mechanism responsible for the {alpha}-particle emission.

  15. Decay studies of the neutron-rich isotopes sup 168 Dy and sup 168 Ho sup g and the identification of the new isomer sup 168 Ho sup m

    SciTech Connect

    Chasteler, R.M.; Nitschke, J.M.; Firestone, R.B.; Vierinen, K.S.; Wilmarth, P.A. )

    1990-11-01

    Multinucleon transfer reactions between {sup 170}Er ions and {sup nat}W targets with on-line mass separation were used to produce neutron-rich {ital A}=168 isotopes. {beta} and {gamma} spectroscopy was used to study the decay of these activities. A new isomer of holmium, {sup 168}Ho{sup {ital m}}, was identified to decay by an isomeric transition with a half-life of 132(4) s. A decay scheme for the most neutron-rich {ital A}=168 isotope, 8.8(3)-min {sup 168}Dy, was determined. Also, a new {ital Q}{sub {beta}}{sup {minus}} value of 2.93(3) MeV for the decay of 3.0-min {sup 168}Ho{sup {ital g}} has been obtained.

  16. Spectroscopy of neutron-rich {sup 168,170}Dy: Yrast band evolution close to the N{sub p}N{sub n} valence maximum

    SciTech Connect

    Soederstroem, P.-A.; Nyberg, J.; Regan, P. H.; Ashley, S. F.; Catford, W. N.; Gelletly, W.; Jones, G. A.; Liu, Z.; Pietri, S.; Podolyak, Zs.; Steer, S. J.; Thompson, N. J.; Williams, S. J.; Algora, A.; Angelis, G. de; Corradi, L.; Fioretto, E.; Gottardo, A.; Grodner, E.; He, C. Y.

    2010-03-15

    The yrast sequence of the neutron-rich dysprosium isotope {sup 168}Dy has been studied using multinucleon transfer reactions following collisions between a 460-MeV {sup 82}Se beam and an {sup 170}Er target. The reaction products were identified using the PRISMA magnetic spectrometer and the gamma rays detected using the CLARA HPGe-detector array. The 2{sup +} and 4{sup +} members of the previously measured ground-state rotational band of {sup 168}Dy have been confirmed and the yrast band extended up to 10{sup +}. A tentative candidate for the 4{sup +}->2{sup +} transition in {sup 170}Dy was also identified. The data on these nuclei and on the lighter even-even dysprosium isotopes are interpreted in terms of total Routhian surface calculations and the evolution of collectivity in the vicinity of the proton-neutron valence product maximum is discussed.

  17. Labeling of biotin with [166Dy]Dy/166Ho as a stable in vivo generator system.

    PubMed

    Ferro-Flores, G; Arteaga de Murphy, C; Pedraza-López, M; Monroy-Guzmán, F; Meléndez-Alafort, L; Tendilla, J I; Jiménez-Varela, R

    2003-04-14

    The aim of this work was to synthesize [166Dy]Dy/166Ho-DTPA-Biotin to evaluate its potential as a new radiopharmaceutical for targeted radiotherapy. Dysprosium-166 (166Dy) was obtained by neutron irradiation of enriched 164Dy(2)O(3) in a Triga Mark III reactor. The labeling was carried out in aqueous media at pH 8.0 by addition of [166Dy]DyCl(3) to diethylenetriaminepentaacetic-alpha,omega-bis(biocytinamide) (DTPA-Biotin). Radiochemical purity was determined by high-performance liquid chromatography (HPLC) and TLC. The biological integrity of labeled biotin was studied evaluating its avidity for avidin in an agarose column and by size-exclusion HPLC analysis of the radiolabeled DTPA-Biotin with and without the addition of avidin. Stability studies against dilution were carried out by diluting the radiocomplex solution with saline solution and with human serum at 37 degrees C for 24 h. The [166Dy]Dy/166Ho-labeled biotin was obtained with a 99.1+/-0.6% radiochemical purity. In vitro studies demonstrated that [166Dy]Dy/166Ho-DTPA-Biotin is stable after dilution in saline and in human serum and no translocation of the daughter nucleus occurs subsequent to beta(-) decay of 166Dy that could produce release of 166Ho(3+). Avidity of labeled biotin for avidin was not affected by the labeling procedure. Biodistribution studies in normal mice showed that the [166Dy]Dy/166Ho-DTPA-Biotin has a high renal clearance. In conclusion, the radiolabeled biotin prepared in this investigation has adequate properties to work as a stable in vivo generator system for targeted radiotherapy. PMID:12672609

  18. [166Dy]Dy/166Ho hydroxide macroaggregates: an in vivo generator system for radiation synovectomy.

    PubMed

    Ferro-Flores, G; Hernández-Oviedo, O; Arteaga de Murphy, C; Tendilla, J I; Monroy-Guzmán, F; Pedraza-López, M; Aldama-Alvarado, K

    2004-12-01

    Radiation synovectomy is an effective treatment in patients suffering from inflammatory-rheumatoid and degenerative joint diseases. The aim of this work was to examine the feasibility of preparing dysprosium-166 (166Dy)/holmium-166(166Ho) hydroxide macroaggregates ([166Dy]Dy/166Ho-HM) as an in vivo generator for radiation synovectomy evaluating whether the stability of 166Dy-HM and 166Ho-HM complexes is maintained when the daughter 166Ho is formed. The Monte Carlo (MCNP4B) theoretical depth dose profile for the in vivo [166Dy]Dy/166Ho generator system in a joint model was calculated and compared with that produced by 90Y, 153Sm and 166Ho. 166Dy was obtained by neutron irradiation of enriched 164Dy2O3 in a Triga Mark III reactor. Macroaggregates were prepared by reaction of [166Dy]DyCl3 with 0.5 M NaOH in an ultrasonic bath. [166Dy]Dy/166Ho-HM was obtained with radiochemical purity >99.5% and with the majority of particles in the 2-5 microm range. In vitro studies demonstrated that the radio-macroaggregates are stable in saline solution and human serum without a significant change in the particle size over 14 d, suggesting that no translocation of the daughter nucleus occurs subsequent to beta- decay of 166Dy. Biological studies in normal rats demonstrated high retention in the knee joint even 7 d after [166Dy]Dy/166Ho-HM administration. The Monte Carlo (MCNP4B) theoretical depth dose profiles in a joint model, showed that the in vivo [166Dy]Dy/166Ho generator system would produce 25% and 50% less radiation dose to the articular cartilage and bone surface, respectively, than that produced by 90Y or pure 166Ho in a treatment with the same therapeutic dose to the synovium surface. Despite that 153Sm showed the best depth dose profile sparing doses to healthy tissues, the use of 166Dy could provide the advantage of being applied in patients that cannot be reached within a few hours from a nuclear reactor and to produce less radiation exposure to the medical personnel

  19. Gamma-rays and conversion electrons from ^205Rn

    NASA Astrophysics Data System (ADS)

    Beausang, C. W.; Novak, J. R.; Barton, C. J.; Caprio, M. A.; Casten, R. F.; Cooper, J. R.; Hecht, A. A.; Krücken, R.; Newman, H.; Pietralla, N.; Zamfir, N. V.; Zyromski, K. E.; Johnson, D. M. S.; Cheng, H.; Birriel, I.; Saladin, J.; Zhang, Jing-Ye

    2001-10-01

    High-spin states in ^205Rn were populated using the ^170Er(^40Ar,5n) reaction at a beam energy of 183 MeV, the ^40Ar beam being provided by the ATLAS accelerator at Argonne National Laboratory. Subsequent gamma-ray and conversion electron decays were measured using the Gammasphere and ICE Ball II arrays. ICE Ball is an array of six mini-orange electron spectrometers and has a total peak efficiency of about 6%. The electron energy resolution obtained with calibration sources was approximately 3.0 keV while an energy resolution of about 10 keV was obtained in beam, the increase being mostly due to the target thickness and Doppler effects. The measured conversion coefficients confirm the previous spin and multipolarity assignments for levels in ^205Rn [1]. In particular, the M1 character of transitions in a proposed shears band is confirmed. In addition, the high quality γ^3 and γ^3 - e-1 coincidence data allowed the identification and placement of several new transitions. The analysis is ongoing and the latest results will be presented. 1. J. Novak et al. Phys. Rev. C59 R2989 (1999). This work is partly supported by the U.S. DOE under grant numbers DE-FG02-91ER-40609, DE-FG02-88ER-40417 and DE-FG02-96ER-40983 and by the DFG under grant number Pi 393/1-1.

  20. A DIAMANT Wedding For AFRODITE: Probing Structure and Characterizing Reaction Properties Via Charged-Particle-{gamma} Correlations

    SciTech Connect

    Mullins, S. M.; Murray, S. H. T.; Bark, R. A.; Gueorguieva, E.; Lawrie, J. J.; Lieder, E. O.; Lieder, R. M.; Papka, P.; Nyako, B. M.; Timar, J.; Berek, G.; Gal, J.; Kalinka, G.; Molnar, J.; Krasznahorkay, A.; Zolnai, L.; Juhasz, K.; Lipoglavsek, M.; Ntshangase, S. S.; Scheurer, J. N.

    2008-05-12

    The DIAMANT-AFRODITE combination has been used to investigate incomplete fusions reactions via the {sup 13}C+{sup 170}Er entrance channel. The intensity of {sup 176}Hf (populated via the {alpha} 3n exit channel) is {approx}8% of {sup 178}W (populated via 5n evaporation) which is {approx}8 times stronger than that expected from complete fusion. Moreover, 2{alpha}xn exit channels leading to Yb nuclei are observed with intensities that are {approx}30-to-40% of {sup 176}Hf, for which no yield is expected from complete fusion. A comparison of the intensities from the two-{alpha}- and one-{alpha}-gated data is consistent with fragmentation of the {sup 13}C beam into ({alpha}-{alpha}-{alpha}-n) which suggests that the population of Yb nuclei results from fusion (or ''massive transfer'') of one the break-up {alpha}-particles. A campaign of measurements is scheduled for late 2007 with further investigations planned for 2008, including the continuation of the study of superdeformation in {sup 32}S.

  1. Two-quasiparticle isomer, E1 hindrances and residual interactions in {sup 172}Tm

    SciTech Connect

    Hughes, R. O.; Lane, G. J.; Dracoulis, G. D.; Kibedi, T.; Nieminen, P.; Watanabe, H.

    2008-04-15

    The structure of the neutron-rich nucleus {sup 172}Tm has been studied using incomplete fusion of {sup 7}Li on an {sup 170}Er target at 30 MeV. A 190-{mu}s isomer at an excitation energy of 476 keV was identified using chopped beams and {gamma}-ray spectroscopy. The isomer decays with very inhibited E1 transitions to the rotational bands based on the parallel and antiparallel couplings of the {nu}5/2{sup -}[512] x {pi}1/2{sup +}[411] configuration, the latter (K{sup {pi}}=2{sup -}) being the ground state. The isomeric state has been assigned J{sup {pi}}=6{sup +}, arising from the energetically favored (parallel) coupling of the {nu}5/2{sup -}[512] x {pi}7/2{sup -}[523] configuration. The proton-neutron residual interaction was deduced for the configuration of the isomeric state and is found to agree with previous empirical studies.

  2. Preparation of a one-curie 171Tm target for the Detector for Advanced Neutron Capture Experiments (DANCE)

    SciTech Connect

    Schwantes, Jon M.; Taylor, Wayne A.; Rundberg, Robert S.; Vieira, David J.

    2008-05-15

    Roughly one curie of 171Tm (t1/2=1.92a) has been produced and purified for the purpose of making a nuclear target for the first measurements of its neutron capture cross section. Target preparation consisted of three key steps: (1) material production; (2) separation and purification; and (3) electrodeposition onto a suitable backing material. Approximately 1.5 mg of the target material (at the time of separation) was produced by irradiating roughly 250 mg of its stable enriched 170Er lanthanide neighbor with neutrons at the ILL reactor in France. This production method resulted in a “difficult-to-separate” 1:167 mixture of near-neighboring lanthanides, Tm and Er. Separation and purification was accomplished using high-performance liquid chromatorgraphy (HPLC), with a proprietary cation exchange column (Dionex, CS-3) and alpha-hydroxyisobutyric acid (a-HIB) eluent. This technique yielded a final product of ~95% purity with respect to Tm. A portion (20 ug) of the Tm was electrodeposited on thin Be foil and delivered to the Los Alamos Neutron Science CEnter (LANSCE) for preliminary analysis of its neutron capture cross section using the Detector for Advanced Neutron Capture Experiments (DANCE). This paper discusses the major hurdles associated with the separation and purification step including, scale-up issues related to the use of HPLC for material separation and purification of the target material from a-HIB and 4-(2-pyridylazo)resorcinol (PAR) colorant.

  3. Rotational bands in neutron-rich {sup 169,171,172}Er

    SciTech Connect

    Wu, C.Y.; Cline, D.; Simon, M.W.; Teng, R.; Vetter, K.; Carpenter, M.P.; Janssens, R.V.F.; Wiedenhoever, I.

    2004-07-01

    The neutron-rich {sup 169,171,172}Er nuclei were populated by few-neutron transfer reactions between {sup 170}Er and {sup 238}U at a near barrier energy. The spectroscopy of these Er isotopes was studied using prompt {gamma} rays correlated with delayed transitions or events involving at least three prompt transitions. The ground-state band of {sup 172}Er was populated up to spin 22{sup +} at an excitation energy of 5528 keV. Rotational bands built on the 1/2{sup -}[521], 5/2{sup -}[512], and 7/2{sup +}[633] neutron configurations in {sup 169,171}Er were extended to substantially higher spins than previously known. The signature splitting observed in these rotational bands is addressed within the framework of the particle-rotor model in terms of triaxiality and Coriolis attenuation. The signature inversion observed in the 5/2{sup -}[512] band is well reproduced by including the triaxial degree of freedom in the calculation. Attenuating the Coriolis interaction in the calculation is found to be necessary to reproduce the signature splitting observed in the 7/2{sup +}[633] band. A similar Coriolis attenuation also is needed to account for the signature splitting as well as the B(M1)/B(E2) ratios in the 7/2{sup +}[633] ground-state band in the neighboring N=99 isotones, {sup 167}Er and {sup 169}Yb.

  4. Isotope shift measurements in the 660 spectral lines of Er I covering the 340-605 nm wavelength region with a Fourier Transform Spectrometer

    NASA Astrophysics Data System (ADS)

    Ankush, B. K.; Deo, M. N.

    2015-04-01

    Isotope shift measurements in 660 spectral lines covering the 340-605 nm wavelength region of Er I were carried out using a Fourier Transform Spectrometer. The spectra were recorded using a liquid nitrogen cooled hollow cathode discharge source containing highly enriched 166Er and 170Er isotopes in the oxide form and two different detectors namely PMT and silicon photo diodes. Out of 660 spectral lines involving 216 even and 182 odd Er I levels, the isotope shift data were new in the 406 lines. On the basis of their level isotope shifts out of 114 unassigned even parity levels 27 levels assigned to 4f116s26p, 72 to 4f115d6s6p and 15 to 4f126s6d configuration whereas 12 each of unassigned odd parity levels assigned to 4f115d6s2, and 4f126s6p configurations and 16 unassigned odd parity levels assigned to 4f115d26s configuration. Configuration mixing for 30 odd parity energy levels has been theoretically calculated applying 'Sharing Rule' to the experimentally derived level isotope shifts, which were finally compared with mixings available in the literature.

  5. PRELIMINARY CROSS SECTION AND NU-BAR COVARIANCES FOR WPEC SUBGROUP 26

    SciTech Connect

    ROCHMAN,D.

    2007-01-31

    We report preliminary cross section covariances developed for the WPEC Subgroup 26 for 45 out of 52 requested materials. The covariances were produced in 15- and 187-group representations as follows: (1) 36 isotopes ({sup 16}O, {sup 19}F, {sup 23}Na, {sup 27}Al, {sup 28}Si, {sup 52}Cr, {sup 56,56}Fe, {sup 58}Ni, {sup 90,91,92,94}Zr, {sup 166,167,168,170}Er, {sup 206,207,208}Pb, {sup 209}Bi, {sup 233,234,236}U, {sup 237}Np, {sup 238,240,241,242}Pu, {sup 241,242m,243}Am, {sup 242,243,244,245}Cm) were evaluated using the BNL-LANL methodology. For the thermal region and the resolved and unresolved resonance regions, the methodology has been based on the Atlas-Kalman approach, in the fast neutron region the Empire-Kalman method has been used; (2) 6 isotopes ({sup 155,156,157,158,160}Gd and {sup 232}Th) were taken from ENDF/B-VII.0; and (3) 3 isotopes ({sup 1}H, {sup 238}U and {sup 239}Pu) were taken from JENDL-3.3. For 6 light nuclei ({sup 4}He, {sup 6,7}Li, {sup 9}Be, {sup 10}B, {sup 12}C), only partial cross section covariance results were obtained, additional work is needed and they do not report the results here. Likewise, the cross section covariances for {sup 235}U, which they recommend to take from JENDL-3.3, will be included once the multigroup processing is successfully completed. Covariances for the average number of neutrons per fission, total {nu}-bar, are provided for 10 actinides identified as priority by SG26. Further work is needed to resolve some of the issues and to produce covariances for the full set of 52 materials.

  6. Nuclear-decay studies of neutron-rich rare-earth nuclides

    SciTech Connect

    Chasteler, R.M. . Dept. of Chemistry Lawrence Berkeley Lab., CA )

    1990-04-26

    Neutron-rich rare-earth nuclei were produced in multinucleon transfer reactions of {sup 170}Er and {sup 176}Yb projectiles on {sup nat}W targets at the Lawrence Berkeley Laboratory SuperHILAC and their radioactive decays properties studied at the on-line mass separation facility OASIS. Two unknown isotopes, {sup 169}Dy (t {sub 1/2} {equals} 39 {plus minus} 8 s) and {sup 174}Er(t{sub 1/2} {equals} 3.3 {plus minus} 0.2 m) were discovered and their decay characteristics determined. The decay schemes for two previously identified isotopes, {sup 168}Dy (t{sub 1/2} {equals} 8.8 {plus minus} 0.3 m) and {sup 171}Ho (t{sub 1/2} {equals} 55 {plus minus} 3 s), were characterized. Evidence for a new isomer of 3.0 m {sup 168}Ho{sup g}, {sup 168}Ho{sup m} (t{sub 1/2} {equals} 132 {plus minus} 4 s) which decays by isomeric transition (IT) is presented. Beta particle endpoint energies were determined for the decay of {sup 168}Ho{sup g}, {sup 169}Dy, {sup 171}Ho, and {sup 174}Er, the resulting Q{beta}-values are: 2.93 {plus minus} 0.03, 3.2 {plus minus} 0.3, 3.2 {plus minus} 0.6, and 1.8 {plus minus} 0.2 MeV, respectively. These values were compared with values calculated using recent atomic mass formulae. Comparisons of various target/ion source geometries used in the OASIS mass separator facility for these multinucleon transfer reactions were performed. 73 refs., 40 figs., 11 tabs.

  7. Nuclear Data Sheets for A = 168

    SciTech Connect

    Baglin, Coral M.

    2010-07-15

    Nuclear structure data pertaining to all nuclei with mass A=168 (Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt) have been evaluated and incorporated into the ENSDF data file. This evaluation supersedes the previous publication (V.S. Shirley, Nuclear Data Sheets 71, 261 (1994) (literature cutoff date July 1993)) and subsequent ENSDF file revisions for Tb and Dy (C. Baglin, literature cutoff date of 15 June 1999) and Hf (B. Singh, literature cutoff date of 30 April 2001), and includes literature available by 15 June 2010. Since the above evaluations, the first excited states in {sup 168}Pt have been identified (1998Ki20, 2009Go16) and {alpha} decay from {sup 172}Hg has been observed (2009Sa27, 2004Ke06, 1999Se14). New levels in {sup 168}Dy have been excited using the {sup 170}Er({sup 82}Se,{sup 84}Kr{gamma}) reaction (2010So03). (HI,xn{gamma}) studies have significantly expanded our knowledge of level structure in {sup 168}Lu (1999Ka17, 2002Ha33), {sup 168}Ta (2008QiZZ), {sup 168}Yb (1995Fi01), {sup 168}Tm (2007CaZW), {sup 168}Hf (2009Ya21), {sup 168}Os (2001Jo11, 2009Od02) and, for {sup 168}Tm, important information has come also from (d,2n{gamma}) and ({alpha},n{gamma}) reactions (1995Si20). Revised decay schemes are available following new studies of {sup 168}Hf {epsilon} decay (6.7 min) (1997Ba26), {sup 168}Lu {epsilon} decay (1999Ba65), {sup 168}Ta {epsilon} decay (2007Mc08) and {sup 172}Au {alpha} decay (2009Ha42). Significant new information for {sup 168}Er is available from (p,t) (2006Bu09), (d,p) and (t,d) (1996Ma50), ({gamma},{gamma}') (1996Ma18), (136Xe, X{gamma}) (2010Dr02), ({sup 238}U,{sup 238}U{sup '{gamma}}) (2003Wu07) and (n,n{sup '{gamma}}) (1998Be20, 1998Be62) reactions, and the availability of {gamma}{gamma} coin data (1994Ju02, 1996Gi09) for the (n,{gamma}) E=thermal reaction has resulted in some significant level scheme revisions.

  8. An NMR investigation of superconductivity and antiferromagnetism in CaFe2As2 under pressure

    SciTech Connect

    Baek, Seung H; Lee, Han O; Bauer, E D; Ronning, F; Park, T; Thompson, J D; Brown, S E; Curro, N J

    2009-01-01

    We report {sup 75}As NMR measurements in CaFe{sub 2}As{sub 2}, made under applied pressures up to 0.83 CPa produced by a standard clamp pressure cell. Our data reveal phase segregation of paramagnetic (PM) and antiferromagnetic (AFM) phases over a range of pressures, with the AFM phase more than 90% dominant at low temperatures. In situ RF susceptibility measurements indicate the presence of superconductivity. {sup 75}As spin-lattice relaxation experiments indicate that the {sup 75}As nuclei sample the superconductivity while in the magnetically-ordered environment.

  9. Radioactive targets for neutron-induced cross section measurements

    SciTech Connect

    Kronenberg, A.; Bond, E. M.; Glover, S. E.; Rundberg, R. S.; Vieira, D. J.; Esch, E. I.; Reifarth, R.; Ullmann, J. L.; Haight, Robert C.; Rochmann, D.

    2004-01-01

    production of radioactive targets of a few milligrams will be described as well as the containment for safe handling of these targets at the Lujan Center at LANSCE. To avoid any contamination, the targets are electrochemically fixed onto thin Ti foils and two foils are placed back to back to contain the radioactive material within. This target sandwich is placed in a cylinder made of aluminum with thin translucent windows made of Kapton. Actinides targets, such as {sup 234,235,236,238}U, {sup 237}Np, and {sup 239}Pu are prepared by electrodeposition or molecular plating techniques. Target thicknesses of 1-2 mg/cm{sup 2} with sizes of 1 cm{sup 2} or more have been made. Other targets will be fabricated from separation of irradiated isotopically enriched targets, such as {sup 155}Eu from {sup 154}Sm,{sup 171}Tm from {sup 170}Er, and {sup 147}Pm from {sup 146}Nd, which has been irradiated in the high flux reactor at ILL, Grenoble. A radioactive sample isotope separator (RSIS) is in the process of being commissioned for the preparation of other radioactive targets. A brief summary of these experiments and the radioactive target preparation technique will be given.

  10. 78 FR 69897 - Self-Regulatory Organizations; NYSE Arca, Inc.; Notice of Filing and Immediate Effectiveness of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-21

    ... Exchange Act Release No. 63275 (November 8, 2010), 75 FR 70048 (November 16, 2010) (SR-NYSEArca-2010-100... Act Release Nos. 65970 (December 15, 2011), 76 FR 79242 (December 21, 2011) (SR-NYSEArca-2011-74) and 65971 (December 15, 2011), 76 FR 79267 (December 21, 2011) (SR-NYSEArca- 2011-75). As specified in...

  11. 77 FR 15459 - Procedures To Establish Appropriate Minimum Block Sizes for Large Notional Off-Facility Swaps and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-15

    ... minimum block trade size.\\18\\ \\11\\ See Real-Time Public Reporting of Swap Transaction Data, 75 FR 76,139... such trade or swap. See 75 FR 76,176. Proposed Sec. 43.5(k)(2) provided that the time delay for... Commission's proposed rulemakings,\\75\\ as well as a report issued by two industry trade associations on...

  12. 78 FR 74203 - Self-Regulatory Organizations; NYSE Arca, Inc.; Notice of Filing and Immediate Effectiveness of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ...), 75 FR 70048 (November 16, 2010) (SR-NYSEArca-2010-100) (the ``Original Co- location Approval''). The.... 65970 (December 15, 2011), 76 FR 79242 (December 21, 2011) (SR-NYSEArca-2011-74) and 65971 (December 15, 2011), 76 FR 79267 (December 21, 2011) (SR-NYSEArca- 2011-75). As specified in the Fee Schedules,...

  13. 30 CFR 75.1504 - Mine emergency evacuation training and drills.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... 75.1504 Section 75.1504 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Mine Emergencies § 75..., as applicable; and (v) Negotiates any other unique escapeway conditions. (4) A review of the mine...

  14. A Case Study of Students Entering an Early College High School: Changes in Academic Behavior Perceptions

    ERIC Educational Resources Information Center

    Healy, James J.

    2009-01-01

    The purpose of this study was to learn more about the transition experiences of one group of high school students (N = 75) as they began attending one alternative pathway: an Early College High School program on a community college campus. A four-part conceptual framework of college readiness provided a structure from which to explore the…

  15. Volovik effect and Fermi-liquid behavior in the s-wave superconductor CaPd2As2: As75 NMR-NQR measurements

    DOE PAGESBeta

    Ding, Q. -P.; Wiecki, P.; Anand, V. K.; Sangeetha, N. S.; Lee, Y.; Johnston, D. C.; Furukawa, Y.

    2016-04-07

    The electronic and magnetic properties of the collapsed-tetragonal CaPd2As2 superconductor (SC) with a transition temperature of 1.27 K have been investigated by 75As nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements. The temperature (T) dependence of the nuclear spin lattice relaxation rates (1/T1) and the Knight shifts indicate the absence of magnetic correlations in the normal state. In the SC state, 1/T1 measured by 75As NQR shows a clear Hebel-Slichter (HS) peak just below Tc and decreases exponentially at lower T, confirming a conventional s-wave SC. Additionally, the Volovik effect, also known as the Doppler shift effect, hasmore » been clearly evidenced by the observation of the suppression of the HS peak with applied magnetic field.« less

  16. Neutron Transfer Reactions: Surrogates for Neutron Capture for Basic and Applied Nuclear Science

    SciTech Connect

    Cizewski, J. A.; Peters, W. A.; Allen, J.; Hatarik, R.; Matthews, C.; O'Malley, P.; Jones, K. L.; Kozub, R. L.; Howard, J.; Patterson, N.; Paulauskas, S. V.; Rogers, J.; Sissom, D. J.; Pain, S. D.; Adekola, A.; Bardayan, D. W.; Blackmon, J. C.; Liang, F.; Nesaraja, C. D.; Pittman, S. T.

    2009-03-10

    Neutron capture reactions on unstable nuclei are important for both basic and applied nuclear science. A program has been developed at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory to study single-neutron transfer (d,p) reactions with rare isotope beams to provide information on neutron-induced reactions on unstable nuclei. Results from (d,p) studies on {sup 130,132}Sn, {sup 134}Te and {sup 75}As are discussed.

  17. 40 CFR 98.33 - Calculating GHG emissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... concentrations, in accordance with Equation F-14a or F-14b (as applicable) in appendix F to 40 CFR part 75, if... section 3.3.5 of appendix F to 40 CFR part 75 are combusted in the unit. If the O2 monitoring option is... section 3.3.6 of appendix F to 40 CFR part 75, as applicable. If Equation F-14b is used, the...

  18. Neutron transfer reactions: Surrogates for neutron capture for basic and applied nuclear science

    SciTech Connect

    Cizewski, J. A.; Jones, K. L.; Kozub, R. L.; Pain, Steven D; Peters, W. A.; Adekola, Aderemi S; Allen, J.; Bardayan, Daniel W; Becker, J.; Blackmon, Jeff C; Chae, K. Y.; Chipps, K.; Erikson, Luke; Gaddis, A. L.; Harlin, Christopher W; Hatarik, Robert; Howard, Joshua A; Jandel, M.; Johnson, Micah; Kapler, R.; Krolas, W.; Liang, J Felix; Livesay, Jake; Ma, Zhanwen; Matei, Catalin; Matthews, C.; Moazen, Brian; Nesaraja, Caroline D; O'Malley, Patrick; Patterson, N. P.; Paulauskas, Stanley; Pelham, T.; Pittman, S. T.; Radford, David C; Rogers, J.; Schmitt, Kyle; Shapira, Dan; ShrinerJr., J. F.; Sissom, D. J.; Smith, Michael Scott; Swan, T. P.; Thomas, J. S.; Vieira, D. J.; Wilhelmy, J. B.; Wilson, Gemma L

    2009-04-01

    Neutron capture reactions on unstable nuclei are important for both basic and applied nuclear science. A program has been developed at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory to study single-neutron transfer (d,p) reactions with rare isotope beams to provide information on neutron-induced reactions on unstable nuclei. Results from (d,p) studies on {sup 130,132}Sn, {sup 134}Te and {sup 75}As are discussed.

  19. Terahertz GaAs/AlAs quantum-cascade lasers

    NASA Astrophysics Data System (ADS)

    Schrottke, L.; Lü, X.; Rozas, G.; Biermann, K.; Grahn, H. T.

    2016-03-01

    We have realized GaAs/AlAs quantum-cascade lasers operating at 4.75 THz exhibiting more than three times higher wall plug efficiencies than GaAs/Al0.25Ga0.75As lasers with an almost identical design. At the same time, the threshold current density at 10 K is reduced from about 350 A/cm2 for the GaAs/Al0.25Ga0.75As laser to about 120 A/cm2 for the GaAs/AlAs laser. Substituting AlAs for Al0.25Ga0.75As barriers leads to a larger energy separation between the subbands reducing the probability for leakage currents through parasitic states and for reabsorption of the laser light. The higher barriers allow for a shift of the quasi-continuum of states to much higher energies. The use of a binary barrier material may also reduce detrimental effects due to the expected composition fluctuations in ternary alloys.

  20. Arsenic and Selenium

    NASA Astrophysics Data System (ADS)

    Plant, J. A.; Kinniburgh, D. G.; Smedley, P. L.; Fordyce, F. M.; Klinck, B. A.

    2003-12-01

    Arsenic (As) and selenium (Se) have become increasingly important in environmental geochemistry because of their significance to human health. Their concentrations vary markedly in the environment, partly in relation to geology and partly as a result of human activity. Some of the contamination evident today probably dates back to the first settled civilizations which used metals.Arsenic is in group 15 of the periodic table (Table 1) and is usually described as a metalloid. It has only one stable isotope, 75As. It can exist in the -III, -I, 0, III, and V oxidation states (Table 2).

  1. [Amizon in the treatment of nervous system involvement in herpes zoster].

    PubMed

    Rudenko, A E; Trinus, F P; Korzhenevskiĭ, L V; Bukhtiarova, T A; Koval', A Z; Malyĭ, V D; Novikova, O V; Tkachenko, E V

    1996-01-01

    The authors submit results of treatment of patients having suffered from postherpetic pain syndrome (herpetic ganglionitis of the cervical, thoracic, lumbosacral localization, postherpetic intercostal neuralgia, ganglionitis of the trigeminal nerve). In viral diseases, amizone has marked analgetic, antiinflammatory, and immunomodulating effects. The drug is well tolerated by patients, is not associated with side effects under prescribed doses (0.25-0.75 as one dose on a three- or four-times daily schedule during the course of treatment lasting three or four weeks). The drug preparation in question is less effective in the treatment of chronic recurring post-therapeutic intercostal neuralgias, radiculalgia. PMID:9377379

  2. Optically Detected Electron-Nuclear Double Resonance of As-Antisite Defects in GaAs

    NASA Astrophysics Data System (ADS)

    Hofmann, D. M.; Meyer, B. K.; Lohse, F.; Spaeth, J.-M.

    1984-09-01

    This Letter reports on the first optically detected electron-nuclear double-resonance (ENDOR) measurements of a paramagnetic semiconductor defect in which ligand hyperfine interactions could be resolved. In semi-insulating GaAs: Cr the ENDOR lines of the first-shell 75As neighbors of the regular tetrahedral AsAs4-antisite defect could be detected and analyzed. The ENDOR investigation reveals that at least one other AsAs4-antisite complex contributes to the same ESR spectrum.

  3. Arsenic-75 and cobalt-59 NMR study of the electron doped barium iron cobalt arsenide

    NASA Astrophysics Data System (ADS)

    Ning, Fanlong

    We report a systematic investigation of the local electronic, magnetic, and superconducting properties of the new iron-based high temperature superconductor Ba(Fe1-xCox) 2As2 (x = 0, 0.02, 0.04, 0.082) through the measurement of 75As and 59Co NMR (Nuclear Magnetic Resonance) lineshapes, Knight shift (K), and spin-lattice relaxation rate (1/T1). The 75As NMR lineshape of the undoped parent compound splits into two sets due to discrete values of hyperfine magnetic field Bchf = +/- 1.32 Tesla below the magnetic ordering temperature to the SDW (Spin Density Wave) state, TSDW. In contrast, for lightly Co doped samples with x = 0.02 and 0.04, the 75As and 59Co lineshapes become broad and featureless below TSDW, indicating that the ground state is no longer the commensurate SDW ordered state. The observed lineshape is consistent with an incommensurate SDW ordered state, or a commensurate state with large distribution of hyperfine field Bhf. In the optimally doped superconductor with x = 0.082 (T c = 22 K), we observe two types of As sites and three types of Co sites, respectively, as expected from a binomial distribution of Co dopants. We found no evidence for induced localized moments in the vicinity of Co dopants. This finding is in remarkable contrast with the case of Zn or Ni doped high Tc cuprates, and suggests that the fundamental physics of iron-based superconductors is different from that of cuprates. The temperature dependences of 75,59K and 75,59(1/ T1T) at both 75As and 59Co sites show that Ba(Fe1-xCo x)2As2 exhibits spin pseudo-gap like behavior down to ˜ 100 K for a broad Co concentration range. Below ˜ 100 K, we observe the enhancement of residual antiferromagnetic spin fluctuations associated with inter-band spin excitations between the hole and electron Fermi surfaces even for x = 0.082. This effect is suppressed in the overdoped sample with x = 0.099, and T c decreases. Therefore, we suggest that antiferromagnetic spin fluctuations play a crucial role

  4. NMR evidence for inhomogeneous nematic fluctuations in BaFe2(As1-xPx)2

    NASA Astrophysics Data System (ADS)

    Dioguardi, Adam P.; Kissikov, Tanat; Lin, Ching-Han; Shirer, Kent R.; Lawson, Matthew M.; Grafe, Hans-Joachim; Chu, Jiun-Haw; Fisher, Ian R.; Fernandes, Rafael M.; Curro, Nicholas J.

    We present evidence for nuclear spin-lattice relaxation driven by glassy nematic fluctuations in isovalent P-doped BaFe2As2 single crystals. Both the 75As and 31P sites exhibit stretched-exponential relaxation similar to the electron-doped systems. By comparing the hyperfine fields and the relaxation rates at these sites we find that the As relaxation cannot be explained solely in terms of magnetic spin fluctuations. We demonstrate that nematic fluctuations couple to the As nuclear quadrupolar moment and can explain the excess relaxation. These results suggest that glassy nematic dynamics are a universal phenomenon in the iron-based superconductors.

  5. NMR Evidence for Inhomogeneous Nematic Fluctuations in BaFe2 (As1 -xPx )2

    NASA Astrophysics Data System (ADS)

    Dioguardi, A. P.; Kissikov, T.; Lin, C. H.; Shirer, K. R.; Lawson, M. M.; Grafe, H.-J.; Chu, J.-H.; Fisher, I. R.; Fernandes, R. M.; Curro, N. J.

    2016-03-01

    We present evidence for nuclear spin-lattice relaxation driven by glassy nematic fluctuations in isovalent P-doped BaFe2As2 single crystals. Both the 75As and 31 sites exhibit a stretched-exponential relaxation similar to the electron-doped systems. By comparing the hyperfine fields and the relaxation rates at these sites we find that the As relaxation cannot be explained solely in terms of magnetic spin fluctuations. We demonstrate that nematic fluctuations couple to the As nuclear quadrupolar moment and can explain the excess relaxation. These results suggest that glassy nematic dynamics are a common phenomenon in the iron-based superconductors.

  6. Multipulse operation and optical detection of nuclear spin coherence in a GaAs/AlGaAs quantum well.

    PubMed

    Kondo, Y; Ono, M; Matsuzaka, S; Morita, K; Sanada, H; Ohno, Y; Ohno, H

    2008-11-14

    We demonstrate manipulation of nuclear spin coherence in a GaAs/AlGaAs quantum well by optically detected nuclear magnetic resonance (NMR). A phase shift of the Larmor precession of photoexcited electron spins is detected to read out the hyperfine-coupled nuclear spin polarization. Multipulse NMR sequences are generated to control the population and examine the phase coherence in quadrupolar-split spin-3/2 75As nuclei. The phase coherence among the multilevel nuclear spin states is addressed by application of pulse sequences that are used in quantum gate operations. PMID:19113379

  7. Cross Section Evaluations for Arsenic Isotopes

    SciTech Connect

    Pruet, J; McNabb, D P; Ormand, W E

    2005-03-10

    The authors present an evaluation of cross sections describing reactions with neutrons incident on the arsenic isotopes with mass numbers 75 and 74. Particular attention is paid to (n,2n) reactions. The evaluation for {sup 75}As, the only stable As isotope, is guided largely by experimental data. Evaluation for {sup 74}As is made through calculations with the EMPIRE statistical-model reaction code. Cross sections describing the production and destruction of the 26.8 ns isomer in {sup 74}As are explicitly considered. Uncertainties and covariances in some evaluated cross sections are also estimated.

  8. Hemimorphite as a natural sink for arsenic in zinc deposits and related mine tailings: Evidence from single-crystal EPR spectroscopy and hydrothermal synthesis

    NASA Astrophysics Data System (ADS)

    Mao, Mao; Lin, Jinru; Pan, Yuanming

    2010-05-01

    Hemimorphite is a refractory mineral in surface environments and occurs commonly in supergene non-sulfide Zn deposits and Zn mine tailings. Single-crystal electron paramagnetic resonance (EPR) spectra of gamma-ray-irradiated hemimorphite from Mapimi (Durango, Mexico) reveal two arsenic-associated oxyradicals: [AsO 4] 4- and [AsO 4] 2-. Inductively coupled plasma mass spectrometry analyses confirm this sample to contain 270 ppm As and that hemimorphite from other Zn deposits has appreciable amounts of arsenic as well. Spin Hamiltonian parameters, including matrices g, A ( 75As) and P( 75As), show that the [AsO 4] 4- radical formed from electron trapping by a locally uncompensated [AsO 4] 3- ion substituting for [SiO 4] 4-. Matrices g, A( 75As) and P( 75As) of the [AsO 4] 2- radical show it to have the unpaired spin on the bridging oxygen of an [AsO 4] 3- ion at a Si site and linked to a monovalent impurity ion. This structural model for the [AsO 4] 2- radical is further supported by observed 29Si and 1H superhyperfine structures arising from interactions with a single Si atom (A/g eβe = ˜1 mT at B// c) and two equivalent H atoms (A/g eβe = ˜0.3 mT at B∧ b = 10°), respectively. Hydrothermal experiments at 200 °C and ˜9.5 MPa show that hemimorphite contains up to ˜2.5 wt% As 2O 5 and suggest that both the arsenate concentration and the pH value in the solution affect the As content in hemimorphite. These results demonstrate that hemimorphite is capable of sequestering arsenate in its crystal lattice, hence is a natural sink for attenuating As in supergene non-sulfide Zn deposits and Zn mine tailings. Moreover, results from hemimorphite potentially have more far-reaching implications for major silicates such as zeolites in the immobilization and removal of arsenic in surface environments.

  9. Evidence for entanglement and full tomographic analysis of Bell states in a single-neutron system

    SciTech Connect

    Hasegawa, Yuji; Loidl, Rudolf; Filipp, Stefan; Badurek, Gerald; Klepp, Juergen; Rauch, Helmut

    2007-11-15

    Tomographic measurements of Bell states of a single-neutron system in an interferometer were carried out. The spin-path joint measurements exhibit clear evidence of entanglement. Reconstructions of the density matrices of, practically complete, Bell states were accomplished. The fidelities as well as the concurrences of the generated states are determined by 0.79 and 0.75 as well as 0.59 and 0.52, respectively, which are again clear evidence of the spin-path entanglement in a single-neutron system.

  10. NMR evidence for inhomogeneous nematic fluctuations in BaFe2(As1-xPx)2

    DOE PAGESBeta

    Dioguardi, A. P.; Kissikov, T.; Lin, C. H.; Shirer, K. R.; Lawson, M. M.; Grafe, H. -J.; Chu, J. -H.; Fisher, I. R.; Fernandes, R. M.; Curro, N. J.

    2016-03-10

    We present evidence for nuclear spin-lattice relaxation driven by glassy nematic fluctuations in isovalent P-doped BaFe2As2 single crystals. Both the 75As and 31P sites exhibit a stretched-exponential relaxation similar to the electron-doped systems. By comparing the hyperfine fields and the relaxation rates at these sites we find that the As relaxation cannot be explained solely in terms of magnetic spin fluctuations. We demonstrate that nematic fluctuations couple to the As nuclear quadrupolar moment and can explain the excess relaxation. Lastly, these results suggest that glassy nematic dynamics are a common phenomenon in the iron-based superconductors.

  11. Stress analysis of hydride bed vessels used for tritium storage

    SciTech Connect

    McKillip, S.T.; Bannister, C.E.; Clark, E.A.

    1991-01-01

    A prototype hydride storage bed, using LaNi{sub 4.25}Al{sub 0.75} as the storage material, was fitted with strain gages to measure strains occurring in the stainless steel bed vessel caused by expansion of the storage powder upon uptake of hydrogen. The strain remained low in the bed as hydrogen was added, up to a bed loading of about 0.5 hydrogen to metal atom ratio (H/M). The strain then increased with increasing hydrogen loading ({approximately} 0.8 H/M). Different locations exhibited greatly different levels of maximum strain. In no case was the design stress of the vessel exceeded.

  12. Stress analysis of hydride bed vessels used for tritium storage

    SciTech Connect

    McKillip, S.T.; Bannister, C.E.; Clark, E.A.

    1991-12-31

    A prototype hydride storage bed, using LaNi{sub 4.25}Al{sub 0.75} as the storage material, was fitted with strain gages to measure strains occurring in the stainless steel bed vessel caused by expansion of the storage powder upon uptake of hydrogen. The strain remained low in the bed as hydrogen was added, up to a bed loading of about 0.5 hydrogen to metal atom ratio (H/M). The strain then increased with increasing hydrogen loading ({approximately} 0.8 H/M). Different locations exhibited greatly different levels of maximum strain. In no case was the design stress of the vessel exceeded.

  13. Antiferromagnetic Spin Fluctuations and Pseudogap Behavior in Ca(Fe1-xCox)2 As2 Studied by 5As NMR

    NASA Astrophysics Data System (ADS)

    Cui, Jinfang; Ran, Sheng; Bud'Ko, Sergey; Canfield, Paul; Furukawa, Yuji

    2015-03-01

    75 As NMR measurements of single-crystalline Ca(Fe1-xCox)2 As2 have been carried out for four different doping concentration crystals (x = 0.023, 0.028, 0.033, 0.059) annealed at 350°C. Co-doped CaFe2As2 is a compound in 122 family of iron-pnictide superconductors with three principle phases exhibited: paramagnetic (PM), antiferromagnetic (AFM) and superconducting (SC) states. The magnetic phase transition to AFM state occurs at TN = 180K at x =0 and is suppressed to TN = 53K for x =0.028, which is accompanied by a structural phase transition from tetragonal to orthorhombic phases. 75As NMR was used to study the low energy spin dynamics via Knight shift (K) and spin-lattice relaxation rate (1/T1) measurements. From our analysis of the temperature dependence of both K and (T1T)-1 in x =0.028 (TN = 53K), 0.033 (Tc = 9K) and 0.059 (Tc = 10K), we found a gradual decrease of AFM spin fluctuations below T* = 88K for x =0.028, 72K for x =0.033 and 41K for x =0.059, respectively, indicating the possible pseudogap behavior in spin excitation spectrum in the system. Supported by USDOE under the Contract No. DE-AC02-07CH11358.

  14. Non-spectral interferences due to the presence of sulfuric acid in inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    García-Poyo, M. Carmen; Grindlay, Guillermo; Gras, Luis; de Loos-Vollebregt, Margaretha T. C.; Mora, Juan

    2015-03-01

    Results of a systematic study concerning non-spectral interferences from sulfuric acid containing matrices on a large number of elements in inductively coupled plasma-mass spectrometry (ICP-MS) are presented in this work. The signals obtained with sulfuric acid solutions of different concentrations (up to 5% w w- 1) have been compared with the corresponding signals for a 1% w w- 1- nitric acid solution at different experimental conditions (i.e., sample uptake rates, nebulizer gas flows and r.f. powers). The signals observed for 128Te+, 78Se+ and 75As+ were significantly higher when using sulfuric acid matrices (up to 2.2-fold for 128Te+ and 78Se+ and 1.8-fold for 75As+ in the presence of 5 w w-1 sulfuric acid) for the whole range of experimental conditions tested. This is in agreement with previously reported observations. The signal for 31P+ is also higher (1.1-fold) in the presence of sulfuric acid. The signal enhancements for 128Te+, 78Se+, 75As+ and 31P+ are explained in relation to an increase in the analyte ion population as a result of charge transfer reactions involving S+ species in the plasma. Theoretical data suggest that Os, Sb, Pt, Ir, Zn and Hg could also be involved in sulfur-based charge transfer reactions, but no experimental evidence has been found. The presence of sulfuric acid gives rise to lower ion signals (about 10-20% lower) for the other nuclides tested, thus indicating the negative matrix effect caused by changes in the amount of analyte loading of the plasma. The elemental composition of a certified low-density polyethylene sample (ERM-EC681K) was determined by ICP-MS after two different sample digestion procedures, one of them including sulfuric acid. Element concentrations were in agreement with the certified values, irrespective of the acids used for the digestion. These results demonstrate that the use of matrix-matched standards allows the accurate determination of the tested elements in a sulfuric acid matrix.

  15. Crystallography and Physical Properties of BaCo2As2, Ba0.94K0.06Co2As2, and Ba0.78K0.22Co2As2

    SciTech Connect

    Anand, V K; Quirinale, Dante G; Lee, Yongbin; Harmon, Bruce N; Furukawa, Yuji; Ogloblichev, V V; Huq, A; Abernathy, D L; Stephens, P W; McQueeney, Robert J; Kreyssig, Aandreas; Goldman, Alan I; Johnston, David C

    2014-08-01

    The crystallographic and physical properties of polycrystalline and single crystal samples of BaCo2As2 and K-doped Ba{1-x}K{x}Co2As2 (x = 0.06, 0.22) are investigated by x-ray and neutron powder diffraction, magnetic susceptibility chi, magnetization, heat capacity Cp, {75}As NMR and electrical resistivity rho measurements versus temperature T. The crystals were grown using both Sn flux and CoAs self-flux, where the Sn-grown crystals contain 1.6-2.0 mol% Sn. All samples crystallize in the tetragonal ThCr2Si2-type structure (space group I4/mmm). For BaCo2As2, powder neutron diffraction data show that the c-axis lattice parameter exhibits anomalous negative thermal expansion from 10 to 300 K, whereas the a-axis lattice parameter and the unit cell volume show normal positive thermal expansion over this T range. No transitions in BaCo2As2 were found in this T range from any of the measurements. Below 40-50 K, we find rho ~ T^2 indicating a Fermi liquid ground state. A large density of states at the Fermi energy D(EF) ~ 18 states/(eV f.u.) for both spin directions is found from low-T Cp(T) measurements, whereas the band structure calculations give D(EF) = 8.23 states/(eV f.u.). The {75}As NMR shift data versus T have the same T dependence as the chi(T) data, demonstrating that the derived chi(T) data are intrinsic. The observed {75}As nuclear spin dynamics are consistent with the presence of ferromagnetic and/or stripe-type antiferromagnetic spin fluctuations. The crystals of Ba{0.78}K{0.22}Co2As2 were grown in Sn flux and show properties very similar to those of undoped BaCo2As2. On the other hand, the crystals from two batches of Ba{0.94}K{0.06}Co2As2 grown in CoAs self-flux show evidence of weak ferromagnetism at T < 10 K with small ordered moments at 1.8 K of 0.007 and 0.03 muB per formula unit, respectively.

  16. Phosphotransacetylase from Clostridium acidiurici1

    PubMed Central

    Robinson, James R.; Sagers, Richard D.

    1972-01-01

    The phosphotransacetylase from Clostridium acidiurici has two properties not observed for this enzyme in other bacteria: (i) it requires a divalent metal for activity, and (ii) it is not subject to uncoupling by arsenate. The enzyme has been obtained in highly purified form, with a specific activity 500-fold higher than crude extracts. Ferrous or manganous ions are required for maximal activity, with Mn2+ being 50 to 75% as effective as Fe2+. The acetyl group can be transferred from acetyl phosphate to coenzyme A in 20 mm arsenate without a net decrease in high-energy acyl linkages. Likewise, H32PO42− will exchange with acetyl-PO42− in the presence of arsenate without loss of acetyl phosphate. This suggests that the active site on the enzyme is capable of discriminating between phosphate and arsenate while permitting the reversible transfer of acyl groups between CoA and phosphate. Images PMID:16559158

  17. New Gammas and Levels of 76Se Observed in the 76Br(β++EC)76Se Decay

    NASA Astrophysics Data System (ADS)

    Shen, S. F.; Yan, Y. P.

    The decay of bromine-76 is studied by means of γ-ray spectroscopy. Bromine-76 is produced via two reactions: 75As(α, 3n)76Br and 76Se(p, n)76Br. The results of these experiments verify the previously reported levels of 76Se. In addition to the previously described transitions and levels, 37 new γ-rays and 15 new energy levels are found for the first time. In addition, in order to study the deformation of 76Se which lies in transitional region between strongly deformed and spherical nuclei, we calculate the total Routhian surfaces (TRS) of positive-parity states by cranking shell model formalism.

  18. NMR investigation of the quasi-one-dimensional superconductor K(2)Cr(3)As(3).

    PubMed

    Zhi, H Z; Imai, T; Ning, F L; Bao, Jin-Ke; Cao, Guang-Han

    2015-04-10

    We report ^{75}As NMR measurements on the new quasi-one-dimensional superconductor K_{2}Cr_{3}As_{3} (T_{c}∼6.1  K) [J. K. Bao et al., Phys. Rev. X 5, 011013 (2015)]. We found evidence for strong enhancement of Cr spin fluctuations above T_{c} in the [Cr_{3}As_{3}]_{∞} double-walled subnanotubes based on the nuclear spin-lattice relaxation rate 1/T_{1}. The power-law temperature dependence, 1/T_{1}T∼T^{-γ} (γ∼0.25), is consistent with the Tomonaga-Luttinger liquid. Moreover, absence of the Hebel-Slichter coherence peak of 1/T_{1} just below T_{c} suggests an unconventional nature of superconductivity. PMID:25910155

  19. VizieR Online Data Catalog: The Fermi GBM catalog (Paciesas+, 2012)

    NASA Astrophysics Data System (ADS)

    Paciesas, W. S.; Meegan, C. A.; von Kienlin, A.; Bhat, P. N.; Bissaldi, E.; Briggs, M. S.; Burgess, J. M.; Chaplin, V.; Connaughton, V.; Diehl, R.; Fishman, G. J.; Fitzpatrick, G.; Foley, S.; Gibby, M.; Giles, M.; Goldstein, A.; Greiner, J.; Gruber, D.; Guiriec, S.; van der Horst, A. J.; Kippen, R. M.; Kouveliotou, C.; Lichti, G.; Lin, L.; McBreen, S.; Preece, R. D.; Rau, A.; Tierney, D.; Wilson-Hodge, C.

    2012-03-01

    The Fermi Gamma-ray Space Telescope was launched on 2008 June 11 on a mission to study the universe at high energies. The onboard Gamma-ray Burst Monitor (GBM) trigger system for detecting GRBs was first enabled on 2008 July 12. In this paper, we provide a catalog of GRBs that triggered the GBM during its first two years of operation. During this time the instrument burst detection algorithms were triggered 908 times: 492 of these are classified as GRBs, 79 as terrestrial gamma-ray flashes (TGFs), 170 as soft gamma-ray repeaters (SGRs), 31 as solar flares, 61 as charged particles, and 75 as others (galactic sources, accidental statistical fluctuations, or too weak to classify). Of the 491 GRBs (in one case the same GRB triggered GBM twice), 18 were detected by the LAT with high confidence above 100MeV (A. Abdo et al. 2012ApJ...744..146A). (5 data files).

  20. Emergent Kondo Lattice Behavior in Iron-Based Superconductors AFe_{2}As_{2} (A=K, Rb, Cs).

    PubMed

    Wu, Y P; Zhao, D; Wang, A F; Wang, N Z; Xiang, Z J; Luo, X G; Wu, T; Chen, X H

    2016-04-01

    Here, we experimentally study the origin of d-electron heavy fermion (HF) behavior in iron-based superconductors (FeSCs) AFe_{2}As_{2} (A=K, Rb, Cs). Nuclear magnetic resonance on ^{75}As reveals a universal coherent-incoherent crossover with a characteristic temperature T^{*}. Below T^{*}, a so-called "Knight shift anomaly" is first observed in FeSCs, which exhibits a scaling behavior similar to f-electron HF materials. Furthermore, the scaling rule also regulates the manifestation of magnetic fluctuation. These results undoubtedly support an emergent Kondo lattice scenario for the d-electron HF behavior, which qualifies the AFe_{2}As_{2} (A=K, Rb, Cs) as d-electron HF superconductors. PMID:27104721

  1. Preparation of thin arsenic and radioarsenic targets for neutron capture studies

    SciTech Connect

    Fassbender, Michael E

    2009-01-01

    A simple method for the electrodeposition of elemental arsenic (As) on a metal backing from aqueous solutions has been developed. The method was successfully applied to stable As (As-75). Thin (2.5 mg {center_dot} cm{sup -2}) coherent, smooth layers of the metalloid on Ti foils (2.5 {micro}m thickness) were obtained. Electrodeposits served as targets for {sup 75}As(n,{gamma}) {sup 76}As neutron capture experiments at Los Alamos Neutron Science Center (LANSCE). Respective {sup 73}As(n,{gamma}) {sup 74}As experiments are planned for the near future, and {sup 73}As targets will be prepared in a similar fashion utilizing the introduced electrodeposition method. The preparation of an {sup 73}As (half-life 80.3 d) plating bath solution from proton irradiated germanium has been demonstrated. Germanium target irradiation was performed at the Los Alamos Isotope Production Facility (IPF).

  2. Estimating the magnitude of peak discharges for selected flood frequencies on small streams in South Carolina (1975)

    USGS Publications Warehouse

    Whetstone, B.H.

    1982-01-01

    A program to collect and analyze flood data from small streams in South Carolina was conducted from 1967-75, as a cooperative research project with the South Carolina Department of Highways and Public Transportation and the Federal Highway Administration. As a result of that program, a technique is presented for estimating the magnitude and frequency of floods on small streams in South Carolina with drainage areas ranging in size from 1 to 500 square miles. Peak-discharge data from 74 stream-gaging stations (25 small streams were synthesized, whereas 49 stations had long-term records) were used in multiple regression procedures to obtain equations for estimating magnitude of floods having recurrence intervals of 10, 25, 50, and 100 years on small natural streams. The significant independent variable was drainage area. Equations were developed for the three physiographic provinces of South Carolina (Coastal Plain, Piedmont, and Blue Ridge) and can be used for estimating floods on small streams. (USGS)

  3. NMR evidence for inhomogeneous glassy behavior driven by nematic fluctuations in iron arsenide superconductors

    NASA Astrophysics Data System (ADS)

    Dioguardi, A. P.; Lawson, M. M.; Bush, B. T.; Crocker, J.; Shirer, K. R.; Nisson, D. M.; Kissikov, T.; Ran, S.; Bud'ko, S. L.; Canfield, P. C.; Yuan, S.; Kuhns, P. L.; Reyes, A. P.; Grafe, H.-J.; Curro, N. J.

    2015-10-01

    We present 75As nuclear magnetic resonance spin-lattice and spin-spin relaxation rate data in Ba (Fe1 -xCox)2As2 and Ba (Fe1 -xCux)2As2 as a function of temperature, doping, and magnetic field. The relaxation curves exhibit a broad distribution of relaxation rates, consistent with inhomogeneous glassy behavior up to 100 K. The doping and temperature response of the width of the dynamical heterogeneity is similar to that of the nematic susceptibility measured by elastoresistance measurements. We argue that quenched random fields which couple to the nematic order give rise to a nematic glass that is reflected in the spin dynamics.

  4. Pharmacokinetic-Pharmacodynamic Contributions to the Convulsant Activity of Fluoroquinolones in Rats

    PubMed Central

    Delon, Annie; Bouquet, Serge; Huguet, Francois; Brunet, Valerie; Courtois, Philippe; Couet, William

    1999-01-01

    The in vivo convulsant activities in rats of five representative fluoroquinolones (FQs), norfloxacin, enoxacin, sparfloxacin, fleroxacin, and pefloxacin, were compared. The experimental approach allowed distinction between the drugs’ ability to reach the pharmacological receptors at the level of the central nervous system (pharmacokinetic contribution) and their ability to interact with these receptors (pharmacodynamic contribution). The presence of a methyl group on the piperazine moiety decreased the pharmacodynamic contribution to the convulsant activity by severalfold, and the ratios of concentrations of the FQs in cerebrospinal fluid (CSF) to concentrations of unbound FQs in plasma varied from about 5 to 75% as a function of lipophilicity. Interestingly, FQs with the highest intrinsic convulsant activities had the lowest levels of diffusion in CSF and vice versa. This in vivo approach provides information complementary to that of in vitro experiments and should be recommended for early preclinical assessment of a new FQ’s epileptogenic risk. PMID:10348785

  5. NMR evidence for inhomogeneous glassy behavior driven by nematic fluctuations in iron arsenide superconductors

    DOE PAGESBeta

    Dioguardi, A. P.; Lawson, M. M.; Bush, B. T.; Crocker, J.; Shirer, K. R.; Nisson, D. M.; Kissikov, T.; Ran, S.; Bud'ko, S. L.; Canfield, P. C.; et al

    2015-10-16

    We present 75As nuclear magnetic resonance spin-lattice and spin-spin relaxation rate data in Ba(Fe1–xCox)2As2 and Ba(Fe1–xCux)2As2 as a function of temperature, doping, and magnetic field. The relaxation curves exhibit a broad distribution of relaxation rates, consistent with inhomogeneous glassy behavior up to 100 K. The doping and temperature response of the width of the dynamical heterogeneity is similar to that of the nematic susceptibility measured by elastoresistance measurements. In this study, we argue that quenched random fields which couple to the nematic order give rise to a nematic glass that is reflected in the spin dynamics.

  6. Competing Magnetic Fluctuations in Iron Pnictide Superconductors: Role of Ferromagnetic Spin Correlations Revealed by NMR

    NASA Astrophysics Data System (ADS)

    Wiecki, P.; Roy, B.; Johnston, D. C.; Bud'ko, S. L.; Canfield, P. C.; Furukawa, Y.

    2015-09-01

    In the iron pnictide superconductors, theoretical calculations have consistently shown enhancements of the static magnetic susceptibility at both the stripe-type antiferromagnetic and in-plane ferromagnetic (FM) wave vectors. However, the possible existence of FM fluctuations has not yet been examined from a microscopic point of view. Here, using 75As NMR data, we provide clear evidence for the existence of FM spin correlations in both the hole- and electron-doped BaFe2As2 families of iron-pnictide superconductors. These FM fluctuations appear to compete with superconductivity and are thus a crucial ingredient to understanding the variability of Tc and the shape of the superconducting dome in these and other iron-pnictide families.

  7. Emergent Kondo Lattice Behavior in Iron-Based Superconductors A Fe2As2 (A =K , Rb, Cs)

    NASA Astrophysics Data System (ADS)

    Wu, Y. P.; Zhao, D.; Wang, A. F.; Wang, N. Z.; Xiang, Z. J.; Luo, X. G.; Wu, T.; Chen, X. H.

    2016-04-01

    Here, we experimentally study the origin of d -electron heavy fermion (HF) behavior in iron-based superconductors (FeSCs) A Fe2As2 (A =K , Rb, Cs). Nuclear magnetic resonance on 75As reveals a universal coherent-incoherent crossover with a characteristic temperature T*. Below T*, a so-called "Knight shift anomaly" is first observed in FeSCs, which exhibits a scaling behavior similar to f -electron HF materials. Furthermore, the scaling rule also regulates the manifestation of magnetic fluctuation. These results undoubtedly support an emergent Kondo lattice scenario for the d -electron HF behavior, which qualifies the A Fe2As2 (A =K , Rb, Cs) as d -electron HF superconductors.

  8. Characterization of bromine-77-labeled proteins prepared using bromoperoxidase

    SciTech Connect

    McElvany, K.D.; Welch, M.J.

    1980-10-01

    The halogenating enzyme bromoperoxidase, isolated from the red algae Bonnemaisonia hamifera and Penicillus capitatus, was used to catalyze the radiohalogenation of proteins at neutral pH. Human serum albumin and canine fibrinogen were halogenated as model compounds; the proteins were labeled with Br-77, produced by the /sup 75/As(..cap alpha..,2n)/sup 77/Br reaction. For each enzyme, the essential reaction parameters (including the concentrations of hydrogen peroxide or of protein, the amount of enzyme used to catalyze the reaction, the pH of the reaction mixture, and the reaction time) were varied to obtain conditions that resulted in the highest yield of radiolabeled protein. The labeled proteins prepared with bromoperoxidase are stable with respect to loss of the radiolabel by hydrolysis and retain their biologic activity. The extension of this method to radiobromination of other types of compounds for imaging and receptor studies seems promising.

  9. Aerated concrete with mineral dispersed reinforcing additives

    NASA Astrophysics Data System (ADS)

    Berdov, G. I.; Ilina, L. V.; Mukhina, I. N.; Rakov, M. A.

    2015-01-01

    To guarantee the production of aerated concrete with the lowest average density while ensuring the required strength it is necessary to use a silica component with a surface area of 250-300 m2 / kg. The article presents experimental data on grinding the silica component together with clinker to the optimum dispersion. This allows increasing the strength of non-autoclaved aerated concrete up to 33%. Furthermore, the addition to aerated concrete the mixture of dispersed reinforcing agents (wollastonite, diopside) and electrolytes with multiply charged cations and anions (1% Fe2 (SO4)3; Al2 (SO4)3) provides the growth of aerated concrete strength at 30 - 75%. As a cohesive the clinker, crushed together with silica and mineral supplements should be used. This increases the strength of aerated concrete at 65% in comparing with Portland cement.

  10. Nuclear-spin observation of noise spectra in semiconductors

    NASA Astrophysics Data System (ADS)

    Sasaki, Susumu; Yuge, Tatsuro; Nishimori, Masashi; Kawanago, Takashi; Hirayama, Yoshiro

    2013-12-01

    We propose a systematic method of obtaining the spectra of noises that cause the decoherence of spins in solids. Based on this method, we experimentally show that this method can be applied to nuclear spins in semiconductors. We clarify that the spectral intensity must be derived from the long-time tail of the multiple-echo decay. To obtain higher-frequency noise, the inversion-pulse interval must be as short as possible, which required us to employ the alternating-phase Carr-Purcell sequence instead of the widely used Carr-Purcell Meiboom-Gill. For 75As nuclear spin in variously-doped GaAs, we observed a Lorentzian spectrum, instead of the commonly observed 1/f spectrum. This indicates that the nuclear spins are indeed in a coherently-controlled state.

  11. [Transmission analysis of the B chromosomes in Locusta migratoria migratorioides R. et F. (Orthoptera, Acrididae) (author's transl)].

    PubMed

    Lepinasse, R

    1977-02-23

    In a African grasshopper population of Locusta migratoria migratorioides reared in the laboratory, B chromosome transmission is analysed in progeny of pairs taken at radom from the population. An accumulation mechanism of Bs exists in the females which presumably results from preferential egregation of the Bs in the female pronucleus. The analysis also shows B chromosome elimination during embryonic and larval development by means of mitotic non-kisjunction: these non-disjunctions induce interfollicular variations in the number of Bs but all the cells of a follicle have the same number of Bs. The frequency of animals with B chromosome rises from 34% to 75% as the diurnal temperature rises from 27 degrees C to 35 degrees C. Thus frequency is controlled by genetic and environmental factors. PMID:837806

  12. Usefulness of urinary growth hormone (GH) measurement for evaluating endogenous GH secretion in acromegaly.

    PubMed

    Mauri, M; Picó, A M; Alfayate, R; Dominguez, J R; Cámara, R; Miralles, C

    1993-01-01

    We investigated the relationship between urinary growth hormone (u-GH) and spontaneous 24-hour plasma GH secretion in 15 acromegalic patients. To measure u-GH, we have developed a method based on concentrating the sample by centrifugal ultrafiltration and then performing an immunoradiometric assay using commercially available reagents. u-GH correlated well with the integrated concentration of plasma GH (r = 0.66, p < 0.02). Additionally, u-GH excretion in acromegalic patients was significantly higher than in the control group (190 +/- 100 vs. 3.89 +/- 0.56 pg/min, mean +/- SEM, p < 0.001). Immunoreactive u-GH showed the same elution pattern in Sephadex G-75 as standard or labeled hGH, proving that the substance measured in urine is authentic GH. In conclusion, u-GH appears to be a simple, noninvasive and inexpensive test for evaluating GH secretion in active acromegaly. PMID:8406334

  13. Growth parameter optimization and interface treatment for enhanced electron mobility in heavily strained GaInAs/AlInAs high electron mobility transistor structures

    SciTech Connect

    Fedoryshyn, Yuriy; Ostinelli, Olivier; Alt, Andreas; Pallin, Angel; Bolognesi, Colombo R.

    2014-01-28

    The optimization of heavily strained Ga{sub 0.25}In{sub 0.75}As/Al{sub 0.48}In{sub 0.52}As high electron mobility transistor structures is discussed in detail. The growth parameters and the channel layer interfaces were optimized in order to maximize the mobility of the two-dimensional electron gas. Structures composed of an 11 nm thick channel layer and a 4 nm thick spacer layer exhibited electron mobilities as high as 15 100 cm{sup 2}/Vs and 70 000 cm{sup 2}/Vs at 300 and 77 K, respectively, for channels including InAs strained layers. The sheet carrier density was kept above 2.5 × 10{sup 12} cm{sup −2} throughout the entire study.

  14. Competing magnetic fluctuations in iron pnictide superconductors: Role of ferromagnetic spin correlations revealed by NMR

    DOE PAGESBeta

    Wiecki, P.; Roy, B.; Johnston, D. C.; Bud’ko, S. L.; Canfield, P. C.; Furukawa, Y.

    2015-09-22

    In the iron pnictide superconductors, theoretical calculations have consistently shown enhancements of the static magnetic susceptibility at both the stripe-type antiferromagnetic and in-plane ferromagnetic (FM) wave vectors. However, the possible existence of FM fluctuations has not yet been examined from a microscopic point of view. Here, using 75As NMR data, we provide clear evidence for the existence of FM spin correlations in both the hole- and electron-doped BaFe2As2 families of iron-pnictide superconductors. Furthermore, these FM fluctuations appear to compete with superconductivity and are thus a crucial ingredient to understanding the variability of Tc and the shape of the superconducting domemore » in these and other iron-pnictide families.« less

  15. Conditions for entangled photon emission from (111)B site-controlled pyramidal quantum dots

    SciTech Connect

    Juska, G. Murray, E.; Dimastrodonato, V.; Chung, T. H.; Moroni, S. T.; Gocalinska, A.; Pelucchi, E.

    2015-04-07

    A study of highly symmetric site-controlled pyramidal In{sub 0.25}Ga{sub 0.75}As quantum dots (QDs) is presented. It is discussed that polarization-entangled photons can be also obtained from pyramidal QDs of different designs from the one already reported in Juska et al. [Nat. Photonics 7, 527 (2013)]. Moreover, some of the limitations for a higher density of entangled photon emitters are addressed. Among these issues are (1) a remaining small fine-structure splitting and (2) an effective QD charging under non-resonant excitation conditions, which strongly reduce the number of useful biexciton-exciton recombination events. A possible solution of the charging problem is investigated exploiting a dual-wavelength excitation technique, which allows a gradual QD charge tuning from strongly negative to positive and, eventually, efficient detection of entangled photons from QDs, which would be otherwise ineffective under a single-wavelength (non-resonant) excitation.

  16. AsGa+ antisites identified by electron spin resonance as a main interface defect system in thermal GaAs/native oxide structures

    NASA Astrophysics Data System (ADS)

    Stesmans, A.; Nguyen, S.; Afanas'ev, V. V.

    2013-10-01

    Aiming to assess the atomic-structural identity of inherently generated interfacial point defects during thermal oxidation, a conventional low-temperature electron spin resonance study has been carried out on (100)GaAs/native oxide structures thermally grown in the range of 350-615 °C on both powders and slices of semi-insulating (100)GaAs. This compellingly reveals substantial generation (density ˜ 1 × 1013 cm-2) of interfacial 75AsGa+ antisites in registry with the GaAs substrate layer, thus providing solid independent evidence of substantial interfacial As enrichment, appearing as endemic to oxidation of GaAs, and at the same time, providing an answer of how a major part of excess As gets interfacially incorporated. Given the known electrical deep double donor attribute of AsGa, direct identification is thus established of a major system of detrimental interface traps.

  17. Using bound exciton transitions to optically resolve neutral donor hyperfine states of various donor species in Silicon-28

    NASA Astrophysics Data System (ADS)

    Salvail, Jeff; Dluhy, Phillip; Saeedi, Kamyar; Szech, Michael; Riemann, Helge; Abromisov, Nikolai; Becker, Peter; Pohl, Hans-Joachim; Thewalt, Michael

    2014-03-01

    Phosphorus in silicon is established as a promising resource for use in quantum information processing tasks. The neutral donor hyperfine states have been shown to have record long coherence times, high fidelity gates via RF pulses, and projective readout via optical bound exciton transitions. As Shannon's theory of information tells us, we can process more information in an alphabet of more symbols, so there is motivation to look at donors with higher nuclear spin than the I = 1 / 2 of 31P, which provide access to Hilbert spaces of dimension greater than two. In this talk I will describe optical studies of the donors 75As (I = 3 / 2), 121Sb (I = 5 / 2), and 209Bi (I = 9 / 2) in 28Si.

  18. Neutralization of Space Charge Effects for Low Energy Ion Beams Using Field Emitters

    SciTech Connect

    Nicolaescu, D.; Sakai, S.; Matsuda, K.; Gotoh, Y.; Ishikawa, J.

    2008-11-03

    The paper presents models and computations for neutralization of space charge effects using electrons provided by field emitter arrays. Different ion species ({sup 11}B{sup +},{sup 31}P{sup +},{sup 75}As{sup +}) with energy in the range E{sub ion} = 200 eV-1 keV have been considered. The ion beam divergence is studied as a function of electron beam geometry and physical parameters (electron and ion energy, electron/ion current ratio I{sub el}/I{sub ion}). The electron beam geometry takes into account electron source positions and initial launching angles. It is shown that optimal ion beam neutralization occurs for low energy electrons emitted parallel to the ion beam.

  19. Ion Beam Neutralization Using FEAs and Mirror Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Nicolaescu, Dan; Sakai, Shigeki; Gotoh, Yasuhito; Ishikawa, Junzo

    2011-01-01

    Advanced implantation systems used for semiconductor processing require transportation of ion beams which are quasi-parallel and have low energy, such as (11B+,31P+,75As+) with energy in the range Eion = 200-1000 eV. Compensation of ion beam divergence may be obtained through electron injection and confinement in regions of non-uniform magnetic fields. Field emitter arrays with special properties are used as electron sources. The present study shows that electron confinement takes place in regions of gradient magnetic field, such as nearby analyzing, collimator and final energy magnets of the ion beam line. Modeling results have been obtained using Opera3D/Tosca/Scala. In regions of gradient magnetic field, electrons have helical trajectories which are confined like a cloud inside curved "magnetic bottles". An optimal range of positions with respect to the magnet for placing electron sources in gradient magnetic field has been shown to exist.

  20. Selective extraction of intracellular components from the microalga Chlorella vulgaris by combined pulsed electric field-temperature treatment.

    PubMed

    Postma, P R; Pataro, G; Capitoli, M; Barbosa, M J; Wijffels, R H; Eppink, M H M; Olivieri, G; Ferrari, G

    2016-03-01

    The synergistic effect of temperature (25-65 °C) and total specific energy input (0.55-1.11 kWh kgDW(-1)) by pulsed electric field (PEF) on the release of intracellular components from the microalgae Chlorella vulgaris was studied. The combination of PEF with temperatures from 25 to 55 °C resulted in a conductivity increase of 75% as a result of cell membrane permeabilization. In this range of temperatures, 25-39% carbohydrates and 3-5% proteins release occurred and only for carbohydrate release a synergistic effect was observed at 55 °C. Above 55 °C spontaneous cell lysis occurred without PEF. Combined PEF-temperature treatment does not sufficiently disintegrate the algal cells to release both carbohydrates and proteins at yields comparable to the benchmark bead milling (40-45% protein, 48-58% carbohydrates). PMID:26722806

  1. Homogeneous coexistence and phase segregation in 1111 iron-based pnictides studied via NMR

    NASA Astrophysics Data System (ADS)

    Fujiwara, Naoki; Kamihara, Yoichi; Matsuishi, Satoru; Hosono, Hideo

    2013-06-01

    We performed 75As and 51Co nuclear magnetic resonance (NMR) measurements on LaFeAsO1- x F x (La1111), a prototype of iron-based superconductors, and on Ca(Fe1- x Co x )AsF (Ca1111), which has a small overlap between the antiferromagnetic (AF) and superconducting (SC) domes in the electronic phase diagram. We found in the Ca1111 series that AF and SC states coexist homogeneously in the overlapped region, while in the La1111 series, we found that paramagnetic (PM) and SC domains coexist around the AF-SC phase boundary. The coexistence of these domains indicates that the AF and SC domes segregate from each other in the electronic phase diagram.

  2. Persistence of slow fluctuations in the overdoped regime of Ba (Fe1 -xRhx) 2As2 superconductors

    NASA Astrophysics Data System (ADS)

    Bossoni, L.; Moroni, M.; Julien, M. H.; Mayaffre, H.; Canfield, P. C.; Reyes, A.; Halperin, W. P.; Carretta, P.

    2016-06-01

    We present nuclear magnetic resonance evidence that very slow (≤1 MHz) spin fluctuations persist into the overdoped regime of Ba (Fe1 -xRhx) 2As2 superconductors. Measurements of the 75As spin echo decay rate, obtained both with Hahn Echo and Carr Purcell Meiboom Gill pulse sequences, show that the slowing down of spin fluctuations can be described by short-range diffusive dynamics, likely involving domain walls motions separating (π /a ,0 ) from (0 ,π /a ) correlated regions. This slowing down of the fluctuations is weakly sensitive to the external magnetic field and, although fading away with doping, it extends deeply into the overdoped regime.

  3. Decoupling a spin qubit from high-frequency Larmor dynamics of a GaAs nuclear spin bath

    NASA Astrophysics Data System (ADS)

    Malinowski, Filip K.; Martins, Frederico; Nissen, Peter D.; Rudner, Mark S.; Marcus, Charles M.; Kuemmeth, Ferdinand; Barnes, Edwin; Fallahi, Saeed; Gardner, Geoffrey C.; Manfra, Michael J.

    We present a technique of decoupling a spin qubit in a GaAs/AlGaAs heterostructure from low- and high-frequency noise arising from hyperfine interaction of electrons with nuclear spins. We use Carr-Purcell-Meiboom-Gill sequences in which we synchronize the repetition rate of π pulses to difference Larmor frequencies of 69Ga, 71Ga and 75As nuclei. This decouples the qubit both from low-frequency noise due to diffusion of nuclear spins and from noise at selected high frequencies, allowing us to apply more than a thousand π pulses in a sequence. We demonstrate a coherence time of a singlet-triplet qubit of 0.87 ms, i.e. five orders of magnitude longer than the inhomogeneous dephasing time intrinsic to GaAs. Support through IARPA-MQCO, Army Research Office, LPS-MPO-CMTC, the Villum Foundation and the Danish National Research Foundation is acknowledged.

  4. Local electromagnetic properties of magnetic pnictides: a comparative study probed by NMR measurements.

    PubMed

    Majumder, M; Ghoshray, K; Ghoshray, A; Pal, A; Awana, V P S

    2013-05-15

    (75)As and (31)P NMR studies are performed in PrCoAsO and NdCoPO respectively. The Knight shift data in PrCoAsO indicate the presence of an antiferromagnetic interaction between the 4f moments along the c axis in the ferromagnetic state of Co 3d moments. We propose a possible spin structure in this system. The (75)As quadrupolar coupling constant, νQ, increases continuously with decrease of temperature and is found to vary linearly with the intrinsic spin susceptibility, K(iso). This indicates the possibility of the presence of a coupling between charge density and spin density fluctuations. Further, the (31)P NMR Knight shift and spin-lattice relaxation rate (1/T1) in the paramagnetic state of NdCoPO indicate that the differences of LaCoPO and NdCoPO from SmCoPO are due to the decrement of the interlayer separation and not due to the moments of the 4f electrons. The nuclear spin-lattice relaxation time (T1) in NdCoPO shows weak anisotropy at 300 K. Using the self-consistent renormalization (SCR) theory of itinerant ferromagnets, it is shown that in the ab plane, the spin fluctuations are three-dimensional ferromagnetic in nature. From SCR theory the important spin-fluctuation parameters (T0, TA, F¯1) are evaluated. The similarities and dissimilarities of the NMR results in As and P based systems with different rare earths are also discussed. PMID:23604391

  5. Capture cross sections for the astrophysical p process

    NASA Astrophysics Data System (ADS)

    Quinn, Stephen J.

    This dissertation includes the design and development of the Summing NaI (SuN) 4pi gamma-ray detector at the National Superconducting Cyclotron Laboratory to measure proton and alpha radiative capture reactions relevant in the astrophysical p process. Discussions of p-process nucleosynthesis, the relevant nuclear reaction theory, experimental details, and analysis procedures are included. All reaction measurements were performed at the Nuclear Science Laboratory of the University of Notre Dame. The commissioning experiments in both regular and inverse kinematics were done using known resonances in the 27Al(p,gamma)28Si and 58Ni(p,gamma) 59Cu reactions, and the results agree well with previous literature values. The success of these proof-of-principle measurements marks the first time that the gamma-summing technique has been implemented in inverse kinematics. Furthermore, in an effort to investigate the synthesis of the light p-process nuclei, the 74Ge(p,gamma)75As, 74Ge(alpha,gamma) 78Se, and 90,92Zr(alpha,gamma)94,96Mo reactions were measured and compared to theoretical calculations using the nuclear statistical model. It was found that the new 74Ge(p,gamma) 75As measurements cause an enhancement in the overproduction of 74Se in p-process models, and that the updated 90Zr(alpha,gamma) 94Mo reaction rate seems to confirms the p-process branching point at 94Mo. Finally, the 58Ni(alpha,gamma) 62Zn reaction was measured for its role in nucleosynthesis in type Ia supernovae. The measurements here lower the reaction rate used in astrophysical models, which leads to a 5% reduction in the calculated abundances of several isotopes. All of the measurements in this dissertation greatly reduce the uncertainty in the reaction cross section.

  6. Intrauterine device survival in Iranian women: systematic review and meta-analysis

    PubMed Central

    Farajzadegan, Ziba; Motamedi, Narges; Nouri, Rasool; Kheyri, Maryam

    2015-01-01

    Introduction: The intrauterine device (IUD) is one of the modern contraception methods that is reversible, safe, effective, and with long-term efficacy. The problem of using this method is early discontinuation. The survival of the IUD use has been reported differently in different studies. In this meta-analysis, we estimated average time of surviving in Iranian women. Materials and Methods: We evaluated the incident of IUD removed in the Iranian women with a broad systematic review of the literature regarding MOOSES criteria. ISI, Scopus, Medline, WHO, Cochrane, Web of Science, Biological abstracts, Google Scholar and DARE and Iran Medex, SID, Magiran and IranDoc were searched. We defined inclusion and exclusion criteria for selection of articles. All chosen articles were appraised using Critical Appraisal Skills Programme checklist. Data were extracted regarding prepared sheets. We used a Cochrane Q-test with a significance <0.1 for checking of heterogeneity of results. We defined I2 = 50–75% as a medium heterogeneity and I2 >75% as high heterogeneity. We applied both fix and random effect model by comprehensive meta-analysis software. Results: A total of 14 articles was included in the systematic review. These were obtained from screening 63 potentially relevant citations and reviewing 17 full-text study articles. One-year survival of IUD, for the random effects model was 78.4% (69.8–85.1%). Three-year survival for the random effects model was 69.4% (53.3–81.9%). Five years for the random effects model was 49.7% (36–63.4%). Conclusion: Above half of Iranian IUD users discontinued it within 5 years after insertion, it means half of IUD expected lifetime was used and make additional costs to the state and the consumer. To reduce these costs, it is recommended for Iranian women to use the IUD with 5-year survival, and they should be consulted before insertion. PMID:25949968

  7. The application of frequency swept pulses for the acquisition of nuclear quadrupole resonance spectra

    NASA Astrophysics Data System (ADS)

    Rossini, Aaron J.; Hamaed, Hiyam; Schurko, Robert W.

    2010-09-01

    The acquisition of nuclear quadrupole resonance (NQR) spectra with wideband uniform rate and smooth truncation (WURST) pulses is investigated. 75As and 35Cl NQR spectra acquired with the WURST echo sequence are compared to those acquired with standard Hahn-echo sequences and echo sequences which employ composite refocusing pulses. The utility of WURST pulses for locating NQR resonances of unknown frequency is investigated by monitoring the integrated intensity and signal to noise of 35Cl and 75As NQR spectra acquired with transmitter offsets of several hundreds kilohertz from the resonance frequencies. The WURST echo sequence is demonstrated to possess superior excitation bandwidths in comparison to the pulse sequences which employ conventional monochromatic rectangular pulses. The superior excitation bandwidths of the WURST pulses allows for differences in the characteristic impedance of the receiving and excitation circuits of the spectrometer to be detected. Impedance mismatches have previously been reported by Marion and Desvaux [D.J.Y. Marion, H. Desvaux, J. Magn. Reson. (2008) 193(1) 153-157] and Muller et al. [M. Nausner, J. Schlagnitweit, V. Smrecki, X. Yang, A. Jerschow, N. Muller, J. Magn. Reson. (2009) 198(1) 73-79]. In this regard, WURST pulse sequences may afford an efficient new method for experimentally detecting impedance mismatches between receiving and excitation circuits, allowing for the optimization of solids and solution NMR and NQR spectrometer systems. The use of the Carr-Purcell Meiboom-Gill (CPMG) pulse sequence for signal enhancement of NQR spectra acquired with WURST pulses and conventional pulses is also investigated. Finally, the utility of WURST pulses for the acquisition of wideline NQR spectra is demonstrated by acquiring part of the 63/65Cu NQR spectrum of CuCN.

  8. Quantitative calibration of radiofrequency NMR Stark effects

    NASA Astrophysics Data System (ADS)

    Tarasek, Matthew R.; Kempf, James G.

    2011-10-01

    Nuclear magnetic resonance (NMR) Stark responses can occur in quadrupolar nuclei for an electric field oscillating at twice the usual NMR frequency (2ω0). Calibration of responses to an applied E field is needed to establish nuclear spins as probes of native E fields within material and molecular systems. We present an improved approach and apparatus for accurate measurement of quadrupolar Stark effects. Updated values of C14 (the response parameter in cubic crystals) were obtained for both 69Ga and 75As in GaAs. Keys to improvement include a modified implementation of voltage dividers to assess the 2ω0 amplitude, |E|, and the stabilization of divider response by reduction of stray couplings in 2ω0 circuitry. Finally, accuracy was enhanced by filtering sets of |E| through a linear response function that we established for the radiofrequency amplifier. Our approach is verified by two types of spectral results. Steady-state 2ω0 excitation to presaturate NMR spectra yielded C14 = (2.59 ± 0.06) × 1012 m-1 for 69Ga at room-temperature and 14.1 T. For 75As, we obtained (3.1 ± 0.1) × 1012 m-1. Both values reconcile with earlier results from 77 K and below 1 T, whereas current experiments are at room temperature and 14.1 T. Finally, we present results where few-microsecond pulses of the 2ω0 field induced small (tens of Hz) changes in high-resolution NMR line shapes. There too, spectra collected vs |E| agree with the model for response, further establishing the validity of our protocols to specify |E|.

  9. Nuclear Data Sheets for A = 75

    SciTech Connect

    Negret, Alexandru; Singh, Balraj

    2013-08-15

    The experimental nuclear spectroscopic data for known nuclides of mass number 75 (Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Kr, Rb, Sr) have been evaluated and presented together with Adopted properties for levels and γ rays. New high-spin data are available for {sup 75}Ga, and {sup 75}Rb; and lifetime data for high-spin states in {sup 75}Br and {sup 75}Kr. For ΔJ =1, M1+E2 transitions in two rotational bands in {sup 75}Kr, several B(E2)(W.u.) values are anomalously high, deviating by 2–3 σ values from currently accepted RUL(E2) = 300. In the opinion of the evaluators, there is need to remeasure level lifetimes and multipole mixing ratios in {sup 75}Kr to resolve this serious discrepancy. New precise single-particle transfer cross section data are available for {sup 75}Ga, {sup 75}Ge, {sup 75}As and {sup 75}Se from several different reactions (2009Ka06,2008Sc03); these data give information for occupancy of valence neutron orbitals in the ground states of target nuclides: {sup 76}Ge, {sup 76}Se and {sup 78}Se. No significant new data since the 1999 NDS for A = 75 have been reported for {sup 75}As and {sup 75}Se. No data are yet available for excited states in {sup 75}Co, {sup 75}Ni and {sup 75}Sr. For {sup 75}Fe, only the isotopic identification is made with one observed event. The radioactive decay schemes of {sup 75}Co and {sup 75}Ni are unknown while those for {sup 75}Rb and {sup 75}Sr are incomplete. This work supersedes the data presented in the previous NDS evaluation of A = 75 published by 1999Fa05.

  10. Arsenic speciation in synthetic gypsum (CaSO4·2H2O): A synchrotron XAS, single-crystal EPR, and pulsed ENDOR study

    NASA Astrophysics Data System (ADS)

    Lin, Jinru; Chen, Ning; Nilges, Mark J.; Pan, Yuanming

    2013-04-01

    Gypsum (CaSO4·2H2O) is a major by-product of mining and milling processes of borate, phosphate and uranium deposits worldwide and, therefore, potentially plays an important role in the stability and bioavailability of heavy metalloids, including As, in tailings and surrounding areas. Gypsum containing 1900 and 185 ppm As, synthesized with Na2HAsO4·7H2O and NaAsO2 in the starting materials, respectively, have been investigated by synchrotron X-ray absorption spectroscopy (XAS), single-crystal electron paramagnetic resonance spectroscopy (EPR), and pulsed electron nuclear double resonance spectroscopy (ENDOR). Quantitative analyses of As K edge XANES and EXAFS spectra show that arsenic occurs in both +3 and +5 oxidation states and the As3+/As5+ value varies from 0.35 to 0.79. Single-crystal EPR spectra of gamma-ray-irradiated gypsum reveal two types of arsenic-associated oxyradicals: [AsO3]2- and an [AsO2]2-. The [AsO3]2- center is characterized by principal 75As hyperfine coupling constants of A1 = 1952.0(2) MHz, A2 = 1492.6(2) MHz and A3 = 1488.7(2) MHz, with the unique A axis along the S-O1 bond direction, and contains complex 1H superhyperfine structures that have been determined by pulsed ENDOR. These results suggest that the [AsO3]2- center formed from electron trapping on the central As5+ ion of a substitutional (AsO4)3- group after removal of an O1 atom. The [AsO2]2- center is characterized by its unique A(75As) axis approximately perpendicular to the O1-S-O2 plane and the A2 axis along the S-O2 bond direction, consistent with electron trapping on the central As3+ ion of a substitutional (AsO3)3- group after removal of an O2 atom. These results confirm lattice-bound As5+ and As3+ in gypsum and point to potential application of this mineral for immobilization and removal of arsenic pollution.

  11. Structure, mechanics, and binding mode heterogeneity of LEDGF/p75-DNA nucleoprotein complexes revealed by scanning force microscopy

    NASA Astrophysics Data System (ADS)

    Vanderlinden, Willem; Lipfert, Jan; Demeulemeester, Jonas; Debyser, Zeger; de Feyter, Steven

    2014-04-01

    LEDGF/p75 is a transcriptional coactivator implicated in the pathogenesis of AIDS and leukemia. In these contexts, LEDGF/p75 acts as a cofactor by tethering protein cargo to transcriptionally active regions in the human genome. Our study - based on scanning force microscopy (SFM) imaging - is the first to provide structural information on the interaction of LEDGF/p75 with DNA. Two novel approaches that allow obtaining insights into the DNA conformation inside nucleoprotein complexes revealed (1) that LEDGF/p75 can bind at least in three different binding modes, (2) how DNA topology and protein dimerization affect these binding modes, and (3) geometrical and mechanical aspects of the nucleoprotein complexes. These structural and mechanical details will help us to better understand the cellular mechanisms of LEDGF/p75 as a transcriptional coactivator and as a cofactor in disease.LEDGF/p75 is a transcriptional coactivator implicated in the pathogenesis of AIDS and leukemia. In these contexts, LEDGF/p75 acts as a cofactor by tethering protein cargo to transcriptionally active regions in the human genome. Our study - based on scanning force microscopy (SFM) imaging - is the first to provide structural information on the interaction of LEDGF/p75 with DNA. Two novel approaches that allow obtaining insights into the DNA conformation inside nucleoprotein complexes revealed (1) that LEDGF/p75 can bind at least in three different binding modes, (2) how DNA topology and protein dimerization affect these binding modes, and (3) geometrical and mechanical aspects of the nucleoprotein complexes. These structural and mechanical details will help us to better understand the cellular mechanisms of LEDGF/p75 as a transcriptional coactivator and as a cofactor in disease. Electronic supplementary information (ESI) available: SFM topographs of phage lambda DNA in situ, in the absence and presence of LEDGF/p75; model-independent tests for DNA chain equilibration in 2D; SFM topographs of

  12. Stable isotope ratio mass spectrometry of nanogram quantities of boron and sulfur

    NASA Astrophysics Data System (ADS)

    Wieser, Michael Eugene

    1998-09-01

    Instrumentation and analytical techniques were developed to measure isotope abundances from nanograms of sulfur and boron. Sulfur isotope compositions were determined employing continuous flow isotope ratio mass spectroscopy (CF-IRMS) procedures and AsS+ thermal ionization mass spectrometry techniques (AsS+-TIMS). Boron isotope abundances were determined by BO2/sp--TIMS. CF-IRMS measurements realized δ34S values from 10 μg sulfur with precisions of ±0.3/perthous. To extend sulfur isotope measurements to much smaller samples, a TIMS procedure was developed to measure 75As32S+ and 75As34S+ at masses 108 and 109 from 200 ng S on a Finnigan MAT 262 with an ion counter. This is possibly the smallest amount of sulfur which has been successfully analyzed isotopically. The internal precision of 32S/34S ratios measured by AsS+-TIMS was better than ±0.15 percent. δ34S-values calculated relative to the measured 32S/34S value of an IAEA AG2S standard (S-1) agreed with those determined by CF-IRMS to within ±3/perthous. The increasing sensitivity of S-isotope analyses permits hiterto impossible investigations e.g. sulfur in tree rings and ice cores. Boron isotope abundances were measured as BO2/sp- from 50 ng B using an older thermal ionization mass spectrometer which had been extensively upgraded including the addition of computer control electronics, sensitive ion current amplification and fiber optic data bus. The internal precisions of the measured 11B/10B ratios were ±0.15 percent and the precisions of δ11B values calculated relative to the accepted international standard (SRM-951) were ±3/perthous. Two applications of boron isotope abundance variations were initiated (1) ground waters of Northern Alberta and (2) coffee beans in different regions of the world. In the first it was demonstrated that boron isotopes could be used to trace boron released during steam injection of oil sands into the surrounding environment. Data from the second study suggest that boron

  13. Inflammatory bowel disease and coronary artery disease.

    PubMed

    Sappati Biyyani, Raja Shekhar R; Fahmy, Nabil M; Baum, Elizabeth; Nelson, Karl M; King, James F

    2009-01-01

    Chronic inflammation with the presence of excess serum acute-phase proteins, cytokines and cell adhesion molecules is increasingly being implicated in atherosclerosis. The association between inflammatory bowel disease (IBD) and coronary artery disease (CAD) is unstudied. This is a preliminary, thesis-generating cross-sectional study aimed at evaluating the presence of traditional atherosclerotic risk factors in patients with IBD and CAD compared with the control population. The medical records of 42 consecutive IBD patients with CAD from 1999 to 2005 (27 men) were reviewed for the Framingham risk factors. The Framingham risk score (FRS) is calculated based on age, sex, hypertension, diabetes and hyperlipidemia. FRS of patients with IBD and CAD was compared with the FRS of 137 age- and sex-matched (102 men) consecutive patients with CAD (controls). When the Framingham risk score adjusted for group and gender with age as a covariate, the adjusted total FRS score was higher in patients with CAD alone (10.0 [3.75]) as compared to those with; IBD and CAD: (8.1 [3.47]; p = 0.001). FRS is lower in cases (patients with IBD and CAD) when compared with the controls (CAD alone). PMID:19529899

  14. NMR study of the AF-SC-SC-AF phased transition in a pnictide superconductor LaFeAsO1-xHx

    NASA Astrophysics Data System (ADS)

    Fujiwara, Naoki; Sakurai, Ryosuke; Iimura, Soushi; Matsuishi, Satoru; Hosono, Hideo; Yamakawa, Youichi; Kontani, Hiroshi

    2014-03-01

    We have performed 75As and 1H NMR measurements in LaFeAsO1xHx, an isomorphic compound of LaFeAsO1xFx. LaFeAsO1xHx is an electron doped system, and O2- can be replaced with H- up to x = 0.5. LaFeAsO1xHx is known for having double superconducting (SC) domes on H doping. Recently, we discovered that a new antiferromagnetic (AF) phase follows the double SC domes on further H doping, forming a symmetric AF-SC-SC-AF phase alignment in the electronic phase diagram Unlike the AF ordering in the lightly H-doped regime, the AF ordering in the highly H-doped regime is attributed to the nesting between electron pockets. In the conference, we will show the data of both NMR spectra and the relaxation rate 1/T1 in the whole doping region. We will discuss the difference of electronic states between the lightly H-doped AF-SC phases and highly H-doped SC-AF phases. This work is supported by a Grant-in-Aid (Grant No. KAKENHI 23340101) from the Ministry of Education, Science, and Culture, Japan.

  15. Quality-of-water data, Palm Beach County, Florida, 1970-1975

    USGS Publications Warehouse

    Miller, Wesley L.; Lietz, Arthur C.

    1976-01-01

    One of the most pressing problems of Palm Beach County, Florida, is the present and potential contamination of the surface and ground-water resources. The canals which dissect the urban and agricultural areas are convenient receptacles for storm-water runoff, sewage effluent, and agricultural wastes. Contaminants in the canals may enter the shallow aquifer as the canal water infiltrates. The quality of water in the shallow aquifer is further influenced by constituents in infiltrating rainwater, septic tank effluent, and many other sources of contamination. The County Health Department has stated that many of the canals and lakes, including Lake Worth, an estuary, have reached levels of contamination rendering them unfit for recreation (Land and others, 1972). The purpose of this report is to: (1) Compile the basic water-quality data collected during 1970-75 as a part of the monitoring program. (2) Make these data available in a usable form to assist in urban and regional planning of the county 's water resources. The water-quality programs include 36 surface-water stations on canals and lakes and 136 ground-water stations which have been regularly sampled. Both urban and agricultural areas are included in the sampling programs. (Woodard-USGS)

  16. Compaction of ribosomal protein S6 by sucrose occurs only under native conditions.

    PubMed

    Chen, LuYang; Ferreira, José A B; Costa, Sílvia M B; Cabrita, Gonçalo J M; Otzen, Daniel E; Melo, Eduardo Pinho

    2006-02-21

    The effect of osmolyte sucrose on the stability and compaction of the folded and unfolded states of ribosomal protein S6 from Thermus thermophilus was analyzed. Confirming previous results obtained with sodium sulfate and trehalose, refolding stopped-flow measurements of S6 show that sucrose favors the conversion of the unfolded state ensemble to a highly compact structure (75% as compact as the folded state). This conversion occurs when the unfolded state is suddenly placed under native conditions and the compact state accumulates in a transient off-folding pathway. This effect of sucrose on the compaction of the unfolded state ensemble is counteracted by guanidinium hydrochloride. The compact state does not accumulate at higher guanidinium concentrations and the unfolded state ensemble does not display increased compaction in the presence of 6 M guanidinium as evaluated by collisional quenching of tryptophan fluorescence. In contrast, accessibility of the tryptophan residue of folded S6 above 1 M sucrose concentration decreased as a result of an increased compaction of the folded state. Unfolding stopped-flow measurements of S6 reflect this increased compaction of the folded state, but the unfolding pathway is not affected by sucrose. Compaction of folded and unfolded S6 induced by sucrose occurs under native conditions indicating that decreased protein conformational entropy significantly contributes to the mechanism of protein stabilization by osmolytes. PMID:16475807

  17. Sharp bends of phononic crystal surface modes

    NASA Astrophysics Data System (ADS)

    Cicek, Ahmet; Salman, Aysevil; Adem Kaya, Olgun; Ulug, Bulent

    2015-12-01

    Sharp bending of surface waves at the interface of a two-dimensional phononic crystal (PnC) of steel cylinders in air and the method of using a diagonally offset cylindrical scatterer are numerically demonstrated by finite-element method simulations. The radii of the diagonally offset scatterer and the cylinder at the PnC corner, along with the distance between them, are treated as optimization parameters in the genetic algorithm optimization of sharp bends. Surface wave transmittance of at most 5% for the unmodified sharp bend is significantly enhanced to approximately 75% as a result of optimization. A series of transmittance peaks whose maxima increase exponentially, as their widths reduce, with increasing frequency is observed for the optimized sharp bend. The transmittance peaks appear at frequencies corresponding to integer plus half-beat periods, depending on the finite surface length. The optimal parameters are such that the cylinder radius at the PnC corner is not significantly modified, whereas a diagonally offset scatterer having a diameter of almost two periods and a shortest distance of about 0.7 periods between them is required for the strongest transmittance peak. Utilization of PnC surface sharp bends as acoustic ring resonators is demonstrated.

  18. Cascaded solar photovoltaic cells based on InP-GaInPAs and InP-CdS heterostructures

    SciTech Connect

    Allakhverdiyev, A.M.; Andreyev, V.; Guseynov, I.A.; Iventyeva, O.O.; Ismailov, V.I.

    1984-08-01

    Cascaded solar cells with different widths of the forbidden band narrow band and wide band were studied. The narrow band cell was based on nInP-n(p)GaInPAs-pInP structure, and the wide band cell was based on pInP-nCdS heterostructure with similar lattice parameters of the contacting materials. The narrow band cells were made by liquid phase epitaxy, and the wide band cells were made by gas transport precipitation of CdS. The spectral characteristics show the feasibility of expanding the region of photosensitivity by using the principle of cascaded conversion of solar energy. The cell with pn junction in Ga0.5In0.75As0.85P0.42 utilizes light with photon energies of less than 1.35 eV that have passed without absorption through the covering photocell. The longwave limits of photosensitivity are determined by the width of the forbidden band of the active region of the corresponding photocells. The shortwave end of the spectrum is stretched out as a result of the low surface recombination rate.

  19. [Evaluating health risk caused by exposure to metals in local foods and drinkable water in Pechenga district of Murmansk region].

    PubMed

    Dudarev, A A; Dushkina, E V; Sladkova, Yu N; Chupahin, V S; Lukichova, L A

    2015-01-01

    Total average daily intake of metals with local food by natives equalled: Cu 2%, Pb 6%, Cd 22%, Hg 40%, Ni 66%, As 157%--in comparison with allowable daily intake. Mushrooms are responsible for total intake of 35% Pb, 55% Cu, 61% Ni and 91% Cd; fish gives 83% Hg and 75% As. The natives' exposure to Ni is caused by mushrooms, wild and cultivated berries and vegetables, exposure to Cd--by mushrooms, that to Hg--by freshwater fish, exposure to As--by salmon and cod. Drinkable water contribution into exposure to metals is negligibly small for Hg, Cd, Pb and Cu, mild for As and considerable for Ni (23%). Total carcinogenous risk with Cu and Pb are negligible, with Cd is 0.22, with Hg 0.39, with Ni 0.81, with As 1.62, with totality of metals for total foods and water--3.1. Total carcinogenous risks with Pb are minimal (less than 10(-6)), with Cd--allowable (less than 10(-5)), with As--average (less than 10(-3)), with Ni--high (10(-2)), with totality of metals for total foods and water--1.25 x 10(-2). Increased health risks revealed necessitate recommendations on reduction/exclusion of some local foods intake by the natives and measures on drinkable water purification from nickel, or usage of other sources of clear water. PMID:26859978

  20. Lanthanide complexes of aminophosphonates as shift reagents for 7Li and 23Na NMR studies in biological systems.

    PubMed

    Ramasamy, R; Castro, M M; de Freitas, D M; Geraldes, C F

    1992-01-01

    A systematic NMR characterization of various Dy(III) complexes of linear and macrocyclic aminophosphonates as 7Li and 23Na NMR shift reagents for biological systems was undertaken. Their efficacy as shift reagents (SR) was tested under constant aqueous solution ionic strength conditions at pH 7.5 as a function of rho = [SR]/[M+]. Further characterization of the two best SRs, Dy(PcPcP)2(7-) and Dy(DOTP)5-, led to the conclusion that, although quite sensitive to solution pH and the presence of alkali metal ions and Mg2+ and Ca2+, these complexes were stable towards hydrolysis by phosphatases. The lack of precipitation of its solutions in the presence of Ca2+, allowed the choice of Dy(DOTP)5- as the best overall SR for biological studies. Other SRs, like Dy(TTHA)3-, although less sensitive to pH and to divalent ions, require significantly higher concentrations to yield the same shifts, leading to large bulk susceptibility artifacts in perfused tissues and organs. PMID:1467337

  1. Accuracy of novel diagnostic biomarkers for hepatocellular carcinoma: An update for clinicians (Review).

    PubMed

    Reichl, Patrick; Mikulits, Wolfgang

    2016-08-01

    Hepatocellular carcinoma (HCC) is the most common liver malignancy and a leading cause of cancer-related mortality worldwide. Accurate detection and differential diagnosis of early HCC can significantly improve patient survival. Currently, detection of HCC in clinical practice is performed by diagnostic imaging techniques and determination of serum biomarkers, most notably α-fetoprotein (AFP), fucosylated AFP and des-γ-carboxyprothrombin. However, these methods display limitations in sensitivity and specificity, especially with respect to early stages of HCC. Recently, high-throughput technologies have elucidated many new pathways involved in hepatocarcinogenesis and have led to the discovery of a plethora of novel, non-invasive serum biomarkers. In particular, the combination of AFP with these new candidate molecules has yielded promising results. In this review, we aimed at recapitulating the most recent (2013-2015) developments in HCC biomarker research. We compared promising novel diagnostic serum protein biomarkers, such as annexin A2, the soluble form of the receptor tyrosine kinase Axl and thioredoxin, as well as their combinations with AFP. High diagnostic performance (area under the curve >0.75) as shown by threshold-independent receiver operating characteristic curve analysis was a prerequisite for inclusion in this review. In addition, we discuss the role and potential of microRNAs in HCC diagnosis and associated methodological challenges. PMID:27278244

  2. Increased vulnerability of the donor organ in related kidney transplants for certain diseases.

    PubMed

    Cats, S; Terasaki, P I; Perdue, S; Mickey, M R

    1984-06-01

    The one-year kidney transplant survival rates from parental donors into recipients with pyelonephritis (PN) was 79% as compared with the low rate of 62% for polycystic disease (PC) and diabetes mellitus (DM). Even more striking was the 42% one-year graft survival in systemic lupus erythematosus (SLE) patients receiving parental donor grafts. HLA-identical sibling donor transplants into patients with DM had a low survival rate of 75% as compared with 90% in PN patients. These results were analyzed for interactions of donor type and disease by comparing the relative survival rates among types of donors within each recipient disease. After taking into account higher overall risks attributable to medical complications inherent in the different disease categories, related donor grafts into patients with PC, SLE, and DM have lower graft survival rates than would be expected from differences in cadaver donor rates by disease. In practical terms, for related donor transplants into patients with SLE, DM, and PC, it may be necessary to consider the vulnerability of the donor organ as another factor. PMID:6375016

  3. Static tensile and tensile creep testing of five ceramic fibers at elevated temperatures

    NASA Technical Reports Server (NTRS)

    Zimmerman, Richard S.; Adams, Donald F.

    1989-01-01

    Static tensile and tensile creep testing of five ceramic fibers at elevated temperature was performed. J.P. Stevens, Co., Astroquartz 9288 glass fiber; Nippon Carbon, Ltd., (Dow Corning) nicalon NLM-102 silicon carbide fiber; and 3M Company Nextel 312, 380, and 480 alumina/silica/boria fibers were supplied in unsized tows. Single fibers were separated from the tows and tested in static tension and tensile creep. Elevated test temperatures ranged from 400 C to 1300 C and varied for each fiber. Room temperature static tension was also performed. Computer software was written to reduce all single fiber test data into engineering constants using ASTM Standard Test Method D3379-75 as a reference. A high temperature furnace was designed and built to perform the single fiber elevated temperature testing up to 1300 C. A computerized single fiber creep apparatus was designed and constructed to perform four fiber creep tests simultaneously at temperatures up to 1300 C. Computer software was written to acquire and reduce all creep data.

  4. Static tensile and tensile creep testing of five ceramic fibers at elevated temperatures

    NASA Technical Reports Server (NTRS)

    Zimmerman, Richard S.; Adams, Donald F.

    1988-01-01

    Static tensile and tensile creep testing of five ceramic fibers at elevated temperature was performed. J.P. Stevens, Co., Astroquartz 9288 glass fiber, Nippon Carbon, Ltd., (Dow Corning) Nicalon NLM-102 silicon carbide fiber, and 3M Company Nextel 312, 380, and 480 alumina/silica/boria fibers were supplied in unsized tows. Single fibers were separated from the tows and tested in static tension and tensile creep. Elevated test temperatures ranged from 400 to 1300 C and varied for each fiber. Room temperature static tension was also performed. Computer software was written to reduce all single fiber test data into engineering constants using ASTM Standard Test Method D3379-75 as a reference. A high temperature furnace was designed and built to perform the single fiber elevated temperature testing up to 1300 C. A computerized single fiber creep apparatus was designed and constructed to perform four fiber creep tests simultaneously at temperatures up to 1300 C. Computer software was written to acquire and reduce all creep data.

  5. Milk Consumption and Mortality from All Causes, Cardiovascular Disease, and Cancer: A Systematic Review and Meta-Analysis.

    PubMed

    Larsson, Susanna C; Crippa, Alessio; Orsini, Nicola; Wolk, Alicja; Michaëlsson, Karl

    2015-09-01

    Results from epidemiological studies of milk consumption and mortality are inconsistent. We conducted a systematic review and meta-analysis of prospective studies assessing the association of non-fermented and fermented milk consumption with mortality from all causes, cardiovascular disease, and cancer. PubMed was searched until August 2015. A two-stage, random-effects, dose-response meta-analysis was used to combine study-specific results. Heterogeneity among studies was assessed with the I² statistic. During follow-up periods ranging from 4.1 to 25 years, 70,743 deaths occurred among 367,505 participants. The range of non-fermented and fermented milk consumption and the shape of the associations between milk consumption and mortality differed considerably between studies. There was substantial heterogeneity among studies of non-fermented milk consumption in relation to mortality from all causes (12 studies; I² = 94%), cardiovascular disease (five studies; I² = 93%), and cancer (four studies; I² = 75%) as well as among studies of fermented milk consumption and all-cause mortality (seven studies; I² = 88%). Thus, estimating pooled hazard ratios was not appropriate. Heterogeneity among studies was observed in most subgroups defined by sex, country, and study quality. In conclusion, we observed no consistent association between milk consumption and all-cause or cause-specific mortality. PMID:26378576

  6. Chelant extraction of heavy metals from contaminated soils using new selective EDTA derivatives.

    PubMed

    Zhang, Tao; Liu, Jun-Min; Huang, Xiong-Fei; Xia, Bing; Su, Cheng-Yong; Luo, Guo-Fan; Xu, Yao-Wei; Wu, Ying-Xin; Mao, Zong-Wan; Qiu, Rong-Liang

    2013-11-15

    Soil washing is one of the few permanent treatment alternatives for removing metal contaminants. Ethylenediaminetetraacetic acid (EDTA) and its salts can substantially increase heavy metal removal from contaminated soils and have been extensively studied for soil washing. However, EDTA has a poor utilization ratio due to its low selectivity resulting from the competition between soil major cations and trace metal ions for chelation. The present study evaluated the potential for soil washing using EDTA and three of its derivatives: CDTA (trans-1,2-cyclohexanediaminetetraacetic acid), BDTA (benzyldiaminetetraacetic acid), and PDTA (phenyldiaminetetraacetic acid), which contain a cylcohexane ring, a benzyl group, and a phenyl group, respectively. Titration results showed that PDTA had the highest stability constants for Cu(2+) and Ni(2+) and the highest overall selectivity for trace metals over major cations. Equilibrium batch experiments were conducted to evaluate the efficacy of the EDTA derivatives at extracting Cu(2+), Zn(2+), Ni(2+), Pb(2+), Ca(2+), and Fe(3+) from a contaminated soil. At pH 7.0, PDTA extracted 1.5 times more Cu(2+) than did EDTA, but only 75% as much Ca(2+). Although CDTA was a strong chelator of heavy metal ions, its overall selectivity was lower and comparable to that of EDTA. BDTA was the least effective extractant because its stability constants with heavy metals were low. PDTA is potentially a practical washing agent for soils contaminated with trace metals. PMID:24076482

  7. Comparative evaluation of botulinum toxin versus iontophoresis with topical aluminium chloride hexahydrate in treatment of palmar hyperhidrosis

    PubMed Central

    Rajagopal, R.; Mallya, Nikhitha B.

    2014-01-01

    Background Hyperhidrosis is generalised or focal excessive sweating and carries a substantial psychological and social burden. This study compares botulinum toxin versus iontophoresis with topical aluminium chloride hexahydrate in palmar hyperhidrosis. Methods The study included 60 cases of palmar hyperhidrosis randomly allocated to 2 groups. One group was given botulinum toxin type A 100 units per palm and the other group subjected to digital iontophoresis with topical application of aluminium chloride hexahydrate lotion for 4 weeks. They were assessed 4 weeks later and those without improvement were crossed over to the other arm for another 4 weeks. Those with improvement were followed up in the same arm for 6 months. Results Botulinum therapy showed significant improvement in the initial (80%) as well as cross over cases (75%) as compared to iontophoresis and aluminium chloride (47%) for initial cases and (17%) for cross over cases. Conclusion Better improvements were seen with botulinum therapy than with iontophoresis and topical therapy. Residual effects of relief lasted on an average for 4 months for botulinum toxin whereas it was one month with iontophoresis and topical therapy. Advantage with iontophoresis and topical therapy was that it was non invasive and did not require regional anaesthesia as with botulinum therapy. PMID:25378778

  8. Polyprenylated Tetraoxygenated Xanthones from the Roots of Hypericum monogynum and Their Neuroprotective Activities.

    PubMed

    Xu, Wen-Jun; Li, Rui-Jun; Quasie, Olga; Yang, Ming-Hua; Kong, Ling-Yi; Luo, Jun

    2016-08-26

    Ten new polyprenylated tetraoxygenated xanthones, monogxanthones A-J (1-10), together with eight known analogues (4b, 11-17) were identified from the roots of Hypericum monogynum. The structures of these new polyprenylated xanthones (1-10), a class of compounds rarely found in plants of the genus Hypericum, were elucidated by the interpretation of their HRESIMS, 1D and 2D NMR, and electronic circular dichroism data. Compounds 1 and 2 exhibited neuroprotective effects against corticosterone (Cort)-induced lesions of PC12 cells at concentrations of 6.25, 12.50, and 25.00 μM, with cell viability greater than 75%, as well as inhibitory effects on nitric oxide production in lipopolysaccharide-induced BV2 microglia cells, with IC50 values of 7.47 ± 0.65 and 9.60 ± 0.12 μM, respectively. Collectively, these results shed new light on the potential of polyprenylated xanthones from the genus Hypericum in the development of antidepression therapies. PMID:27525351

  9. Rapid High Performance Liquid Chromatographic Method for Determination of Clarithromycin in Human Plasma Using Amperometric Detection: Application in Pharmacokinetic and Bioequivalence Studies

    PubMed Central

    Foroutan, Seyed Mohsen; Zarghi, Afshin; Shafaati, Alireza; Madadian, Babak; Abolfathi, Farshid

    2013-01-01

    A rapid, sensitive and reproducible HPLC method using amperometric detector was developed and validated for the analysis of clarithromycin in human plasma. The separation was achieved on a monolithic silica column (MZ- C8 125×4.0 mm) using acetonitrile-methanol-potassium dihydrogen phosphate buffer (40:6:54,v/v), with pH of 7.5, as the mobile phase at a flow rate of 1.5 mL/min. The assay enables the measurement of clarithromycin for therapeutic drug monitoring with a minimum quantification limit of 20 ng/mL. The method involves simple, protein precipitation procedure and analytical recovery was complete. The calibration curve was linear over the concentration range of 0.1-6 μg/mL. The coefficients of variation for inter-day and intra-day assay were found to be less than 6%. This method was used in bioequivalency and pharmacokinetic studies of the test (generic) product 2 × 500 mg clarithromycin tablets, with respect to the reference product. PMID:24250673

  10. Rapid high performance liquid chromatographic method for determination of clarithromycin in human plasma using amperometric detection: application in pharmacokinetic and bioequivalence studies.

    PubMed

    Foroutan, Seyed Mohsen; Zarghi, Afshin; Shafaati, Alireza; Madadian, Babak; Abolfathi, Farshid

    2013-01-01

    A rapid, sensitive and reproducible HPLC method using amperometric detector was developed and validated for the analysis of clarithromycin in human plasma. The separation was achieved on a monolithic silica column (MZ- C8 125×4.0 mm) using acetonitrile-methanol-potassium dihydrogen phosphate buffer (40:6:54,v/v), with pH of 7.5, as the mobile phase at a flow rate of 1.5 mL/min. The assay enables the measurement of clarithromycin for therapeutic drug monitoring with a minimum quantification limit of 20 ng/mL. The method involves simple, protein precipitation procedure and analytical recovery was complete. The calibration curve was linear over the concentration range of 0.1-6 μg/mL. The coefficients of variation for inter-day and intra-day assay were found to be less than 6%. This method was used in bioequivalency and pharmacokinetic studies of the test (generic) product 2 × 500 mg clarithromycin tablets, with respect to the reference product. PMID:24250673

  11. Accuracy of novel diagnostic biomarkers for hepatocellular carcinoma: An update for clinicians (Review)

    PubMed Central

    Reichl, Patrick; Mikulits, Wolfgang

    2016-01-01

    Hepatocellular carcinoma (HCC) is the most common liver malignancy and a leading cause of cancer-related mortality worldwide. Accurate detection and differential diagnosis of early HCC can significantly improve patient survival. Currently, detection of HCC in clinical practice is performed by diagnostic imaging techniques and determination of serum biomarkers, most notably α-fetoprotein (AFP), fucosylated AFP and des-γ-carboxyprothrombin. However, these methods display limitations in sensitivity and specificity, especially with respect to early stages of HCC. Recently, high-throughput technologies have elucidated many new pathways involved in hepatocarcinogenesis and have led to the discovery of a plethora of novel, non-invasive serum biomarkers. In particular, the combination of AFP with these new candidate molecules has yielded promising results. In this review, we aimed at recapitulating the most recent (2013–2015) developments in HCC biomarker research. We compared promising novel diagnostic serum protein biomarkers, such as annexin A2, the soluble form of the receptor tyrosine kinase Axl and thioredoxin, as well as their combinations with AFP. High diagnostic performance (area under the curve >0.75) as shown by threshold-independent receiver operating characteristic curve analysis was a prerequisite for inclusion in this review. In addition, we discuss the role and potential of microRNAs in HCC diagnosis and associated methodological challenges. PMID:27278244

  12. Induction of hsp70 by the herbicide oxyfluorfen (Goal) in the Egyptian Nile fish, Oreochromis niloticus.

    PubMed

    Hassanein, H M; Banhawy, M A; Soliman, F M; Abdel-Rehim, S A; Müller, W E; Schröder, H C

    1999-07-01

    This paper deals with the expression of the biomarker hsp70 in the liver and kidney of the freshwater fish Oreochromis niloticus following exposure to the herbicide oxyfluorfen (Goal). Fishes were exposed to three concentrations, the 96-h LC50 (3 mg/L), the 96-h (1/2)LC50 (1.5 mg/L), and the 96-h (1/4)LC50 (0.75 mg/L) of oxyfluorfen for 6, 15, and 24 days, respectively, and samples were taken at three different time periods for each concentration. The livers responded to the herbicide by an induction of the expression of both the constitutive (hsp75; Mr 75 kDa) and the inducible (hsp73; Mr 73 kDa) hsp70 proteins. In kidney, the herbicide induced a time-dependent increase in the expression of the constitutive hsp70 (hsp75) as well, but the inducible hsp70 (hsp73) required much longer incubation periods to reach maximal levels (15 and 24 days). Our results suggest that expression of hsp70 in fish is a sensitive indicator of cellular responses to herbicide exposure in the aquatic environment. PMID:10341045

  13. Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates

    USGS Publications Warehouse

    Vorsino, Adam E.; Fortini, Lucas B.; Amidon, Fred A.; Miller, Stephen E.; Jacobi, James D.; Price, Jonathan P.; `Ohukani`ohi`a Gon, Sam, III; Koob, Gregory A.

    2014-01-01

    Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with 0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions.

  14. Milk Consumption and Mortality from All Causes, Cardiovascular Disease, and Cancer: A Systematic Review and Meta-Analysis

    PubMed Central

    Larsson, Susanna C.; Crippa, Alessio; Orsini, Nicola; Wolk, Alicja; Michaëlsson, Karl

    2015-01-01

    Results from epidemiological studies of milk consumption and mortality are inconsistent. We conducted a systematic review and meta-analysis of prospective studies assessing the association of non-fermented and fermented milk consumption with mortality from all causes, cardiovascular disease, and cancer. PubMed was searched until August 2015. A two-stage, random-effects, dose-response meta-analysis was used to combine study-specific results. Heterogeneity among studies was assessed with the I2 statistic. During follow-up periods ranging from 4.1 to 25 years, 70,743 deaths occurred among 367,505 participants. The range of non-fermented and fermented milk consumption and the shape of the associations between milk consumption and mortality differed considerably between studies. There was substantial heterogeneity among studies of non-fermented milk consumption in relation to mortality from all causes (12 studies; I2 = 94%), cardiovascular disease (five studies; I2 = 93%), and cancer (four studies; I2 = 75%) as well as among studies of fermented milk consumption and all-cause mortality (seven studies; I2 = 88%). Thus, estimating pooled hazard ratios was not appropriate. Heterogeneity among studies was observed in most subgroups defined by sex, country, and study quality. In conclusion, we observed no consistent association between milk consumption and all-cause or cause-specific mortality. PMID:26378576

  15. Artificial defoliation effect on Populus growth, biomass production, and total nonstructural carbohydrate concentration

    SciTech Connect

    Reichenbacker, R.R.; Hart, E.R.; Schultz, R.C.

    1996-06-01

    The impact of artificial defoliation on Populus growth, biomass production, and total nonstructural carbohydrate concentration was examined. Four Populus clones were field planted and artificially defoliated. Assigned defoliation levels (0, 25, 50, or 75%) were applied to leaves of leaf plastochron index 0 through 8 during a 6-d period in a 3-step incremental manner to simulate cottonwood leaf beetle, Chrysomela scripta F., larval feeding patterns. Artificial defoliations were timed to coincide with the outbreaks of natural beetle populations in adjacent areas. After 2 growing seasons, trees were measured for height, diameter, and biomass accumulation. Root samples were collected from 0 and 75% defoliation treatments for each clone. Biomass was reduced an average of 33% as defoliation level increased from 0 to 75%. As defoliation level increased from 0 to 75%, a consistent allocation ratio of biomass to 2/3 above and 1/3 below ground components continued in all clones. An overcompensation response occurred in above ground biomass when a defoliation level of 25% was applied. Between 25 and 75% a strong linear trend of decreasing biomass as defoliation increased was indicated. Vitality of the tree, as indicated by total nonstructural carbohydrate content, was affected only slightly by increasing defoliation. 26 refs., 1 fig., 6 tabs.

  16. Progressive slowing down of spin fluctuations in underdoped LaFeAsO1-xFx

    NASA Astrophysics Data System (ADS)

    Hammerath, F.; Gräfe, U.; Kühne, T.; Kühne, H.; Kuhns, P. L.; Reyes, A. P.; Lang, G.; Wurmehl, S.; Büchner, B.; Carretta, P.; Grafe, H.-J.

    2013-09-01

    The evolution of low-energy spin dynamics in the iron-based superconductor LaFeAsO1-xFx was studied over a broad doping, temperature, and magnetic field range (x= 0-0.15, T≤ 480 K, μ0H≤ 30 T) by means of 75As nuclear magnetic resonance. An enhanced spin-lattice relaxation rate divided by temperature (T1T)-1 in underdoped superconducting samples (x= 0.045, 0.05, and 0.075) suggests the presence of antiferromagnetic spin fluctuations, which are strongly reduced in optimally doped (x=0.10) and completely absent in overdoped (x=0.15) samples. In contrast to previous analysis, Curie-Weiss fits are shown to be insufficient to describe the data over the whole temperature range. Instead, a Bloembergen-Purcell-Pound (BPP) model is used to describe the occurrence of a peak in (T1T)-1 clearly above the superconducting transition, reflecting a progressive slowing down of the spin fluctuations down to the superconducting phase transition.

  17. Single attosecond pulse generation in an orthogonally polarized two-color laser field combined with a static electric field

    SciTech Connect

    Xia Changlong; Zhang Gangtai; Wu Jie; Liu Xueshen

    2010-04-15

    We investigate theoretic high-order harmonic generation and single attosecond pulse generation in an orthogonally polarized two-color laser field, which is synthesized by a mid-infrared (IR) pulse (12.5 fs, 2000 nm) in the y component and a much weaker (12 fs, 800 nm) pulse in the x component. We find that the width of the harmonic plateau can be extended when a static electric field is added in the y component. We also investigate emission time of harmonics in terms of a time-frequency analysis to illustrate the physical mechanism of high-order harmonic generation. We calculate the ionization rate using the Ammosov-Delone-Krainov model and interpret the variation of harmonic intensity for different static electric field strengths. When the ratio of strengths of the static and the y-component laser fields is 0.1, a continuous harmonic spectrum is formed from 220 to 420 eV. By superposing a properly selected range of the harmonic spectrum from 300 to 350 eV, an isolated attosecond pulse with a duration of about 75 as is obtained, which is near linearly polarized.

  18. Bioethics and why I hope to live beyond age 75 attaining wisdom!: A rebuttal to Dr. Ezekiel Emanuel's 75 age limit

    PubMed Central

    Faria, Miguel A.

    2015-01-01

    American bioethicists have been providing persuasive arguments for rationing medical care via the theory of the necessary “rational allocation of finite health care resources.” Anticipating the need for the drastic rationing of medical care in the U.S. with the implementation of ObamaCare and assisted by various sectors of organized medicine in league with the State, bioethicists have deduced that more ingenious approaches are necessary to convince Americans who have been accustomed to receiving the best medical care that third-party payers are willing to pay for. It is in this context that the individual-based, patient-oriented ethics of Hippocrates, including his fundamental dictum, “First Do No Harm,” have to be supplanted by the utilitarian approach promoted by the bioethicists. And today's foremost proponent of the bioethics movement is Dr. Ezekiel Emanuel. This editorial proposes a rational rebuttal to Dr. Emanuel's proposal to limit life expectancy to age 75 as a rational paradigm to a better life. PMID:25789197

  19. Purification and Characterization of Intracellular Cellulase from Aspergillus oryzae ITCC-4857.01

    PubMed Central

    Absar, Nurul

    2009-01-01

    Purification and characterization of intracellular cellulase produced by A. oryzae ITCC-4857.01 are reported. The enzyme was purified by ion-exchange chromatography using DEAE-cellulose followed by Gel filtration. The purification achieved was 41 fold from the crude extract with yield of 27%. The purified enzyme showed single band on poly acrylamide gel. The molecular weight as determined by SDS-PAGE and gel filtration was 38 KDa and 38.6 KDa respectively and contained only one subunit. The enzyme is glycoprotien as nature and contained 0.67% neutral sugar. The apparent Km value of the enzyme against cellulose was 0.83%. The enzyme showed the highest relative ativities on CMC followed by avicel, salicin and filter paper. The optimum pH of activity was 5.5 and very slight activity was observed at or above pH 7.5 as well as bellow pH 3.5. The optimum tempreture of the activity was 45℃ and the highest activity was exhibited in 35 to 45℃. The enzyme lost their activities almost completely (95~100%) at 80 ℃ or above and as well as bellow 25℃. PMID:23983520

  20. [Role of Mg2+-dependent alkaline endodnaase of blood serum in tumorigenesis in A/smail mice].

    PubMed

    Kovalenko, G A; Lel'kin, M K; Panin, L E

    2006-01-01

    An enzymoassay of levels of Mg2+-dependent alkaline endoDNAase of protein spectrum of blood serum of noninbred albino mice by SDS-electrophoresis in 10% PAAG established a fairly high heterogeneity of the enzyme. The variety of alkaline endoDNAases must be due to the limited proteolysis of their high-molecular precursor by specific proteases as described in the literature. No alkaline endoDNAase activity was identified by analysis of 10-150 kDa protein spectrum in A/smail line mice without ascites hepatoma. It was detected (pH 8.3) in the 25-45 kDa range on day 10 after tumor transplantation. Considering the gravity of disease (pre-lethal stage), on day 10, it was suggested that the level be accounted for by decay of diseased cells. The lack or extremely low level of endoDNAase activity in original blood serum expressed a mechanism of enhancing sensitivity to tumor cell effects. In mice bearing ascites hepatoma, the enzyme levels (pH 8.3) were much higher on day 10. DNAase activity (pH 7.5) was not induced in response to the heterogenous DNA. Our data point to possible defects in the induction of Mg2+-dependent alkaline endoDNAases (pH 8.3) and DNAses (pH 7.5) as well as their role in raising sensitivity to transplantable ascites hepatoma. PMID:17191709

  1. Investigation on electronic, mechanical and thermal properties of Hf-H system

    NASA Astrophysics Data System (ADS)

    Wang, Hao; Konashi, Kenji

    2013-11-01

    Hf hydride is proposed to be used as neutron control materials for fast reactors. The electronic, mechanical and thermal properties of its three phases: δ‧-HfH1.5, δ-HfH1.75, ε-HfH2, are investigated. Their relative stabilities at 0 K by our calculation are consistent with the explanation of Jahn-Teller mechanism. The mechanical properties like elastic constants are calculated and agree well with the experiments. At finite temperatures, in addition to the direct method for phonon calculation, electronic free energy is also calculated in order to investigate the thermal expansion and bulk moduli of three phases. Hf-H system has an increasing relationship in bulk moduli with respect to the H concentration before about 360 K, after which ε-HfH2 seems to decrease more quickly in the softness of the structure than δ-HfH1.75 as the temperature increases. The relation between heat capacity and Hf and H atoms vibration is discussed.

  2. Atmospheric effects on radiation reflected from soil and vegetation as measured by orbital sensors using various scanning directions

    NASA Technical Reports Server (NTRS)

    Slater, P. N.; Jackson, R. D.

    1982-01-01

    Ground-measured spectral reflectance data for Avondale loam and drought-stressed and unstressed wheat were converted into digital counts for spectral bands 5 and 7 of the Landsat Multispectral Scanner System (MSS). For dry loam, the differences between ratios of MSS bands 7-5 as determined from space and from ground level measurements were 2.3 percent for clear and 5.6 percent for turbid atmospheric conditions. By contrast, for wet loam the differences were 10.4 and 29.5 percent. It is found that atmospheric conditions may cause a delay of from 3 to 7 days in the discrimination between drought-stressed and unstressed wheat. For oblique angle observations the atmospheric modification of ground-measured reflectances increased with angle at a greater rate in the 0/180 deg azimuth than in the 90/270 deg azimuth. Implications of this result are discussed for oblique angle Systeme Probatoire d'Observation de la Terre (SPOT), Mapsat, future multispectral linear array system imagery, and wide-angle imagery collected from scanners in high-altitude aircraft.

  3. Ion beam neutralization using three-dimensional electron confinement by surface modification of magnetic poles

    NASA Astrophysics Data System (ADS)

    Nicolaescu, Dan; Sakai, Shigeki; Gotoh, Yasuhito; Ishikawa, Junzo

    2011-07-01

    Advanced implantation systems used for semiconductor processing require transportation of quasi-parallel ion beams, which have low energy ( 11B +, 31P +, 75As +, Eion=200-1000 eV). Divergence of the ion beam due to space charge effects can be compensated through injection of electrons into different regions of the ion beam. The present study shows that electron confinement takes place in regions of strong magnetic field such as collimator magnet provided with surface mirror magnetic fields and that divergence of the ion beam passing through such regions is largely reduced. Modeling results have been obtained using Opera3D/Tosca/Scala. Electrons may be provided by collision between ions and residual gas molecules or may be injected by field emitter arrays. The size of surface magnets is chosen such as not to disturb ion beam collimation, making the approach compatible with ion beam systems. Surface magnets may form thin magnetic layers with thickness h=0.5 mm or less. Conditions for spacing of surface magnet arrays for optimal electron confinement are outlined.

  4. Wealth inhomogeneity applied to crash rate theory.

    PubMed

    Shuler, Robert L

    2015-11-01

    A crash rate theory based on corporate economic utility maximization is applied to individual behavior in U.S. and German motorway death rates, by using wealth inhomogeneity data in ten-percentile bins to account for variations of utility maximization in the population. Germany and the U.S. have similar median wealth figures, a well-known indicator of accident risk, but different motorway death rates. It is found that inhomogeneity in roughly the 10(th) to 30(th) percentile, not revealed by popular measures such as the Gini index which focus on differences at the higher percentiles, provides a satisfactory explanation of the data. The inhomogeneity analysis reduces data disparity from a factor of 2.88 to 1.75 as compared with median wealth assumed homogeneity, and further to 1.09 with average wealth assumed homogeneity. The first reduction from 2.88 to 1.75 is attributable to inequality at lower percentiles and suggests it may be as important in indicating socioeconomic risk as extremes in the upper percentile ranges, and that therefore the U.S. socioeconomic risk may be higher than generally realized. PMID:27441226

  5. Effect of fiber treatments on tensile and thermal properties of starch/ethylene vinyl alcohol copolymers/coir biocomposites.

    PubMed

    Rosa, Morsyleide F; Chiou, Bor-sen; Medeiros, Eliton S; Wood, Delilah F; Williams, Tina G; Mattoso, Luiz H C; Orts, William J; Imam, Syed H

    2009-11-01

    Coir fibers received three treatments, namely washing with water, alkali treatment (mercerization) and bleaching. Treated fibers were incorporated in starch/ethylene vinyl alcohol copolymers (EVOH) blends. Mechanical and thermal properties of starch/EVOH/coir biocomposites were evaluated. Fiber morphology and the fiber/matrix interface were further characterized by scanning electron microscopy (SEM). All treatments produced surface modifications and improved the thermal stability of the fibers and consequently of the composites. The best results were obtained for mercerized fibers where the tensile strength was increased by about 53% as compared to the composites with untreated fibers, and about 33.3% as compared to the composites without fibers. The mercerization improved fiber-matrix adhesion, allowing an efficient stress transfer from the matrix to the fibers. The increased adhesion between fiber and matrix was also observed by SEM. Treatment with water also improved values of Young's modulus which were increased by about 75% as compared to the blends without the fibers. Thus, starch/EVOH blends reinforced with the treated fibers exhibited superior properties than neat starch/EVOH. PMID:19560341

  6. The Chicken Frizzle Feather Is Due to an α-Keratin (KRT75) Mutation That Causes a Defective Rachis

    PubMed Central

    Foley, John; Foley, Anne; McDonald, Merry-Lynn; Juan, Wen-Tau; Huang, Chih-Jen; Lai, Yu-Ting; Lo, Wen-Sui; Chen, Chih-Feng; Leal, Suzanne M.; Zhang, Huanmin; Widelitz, Randall B.; Patel, Pragna I.; Li, Wen-Hsiung; Chuong, Cheng-Ming

    2012-01-01

    Feathers have complex forms and are an excellent model to study the development and evolution of morphologies. Existing chicken feather mutants are especially useful for identifying genetic determinants of feather formation. This study focused on the gene F, underlying the frizzle feather trait that has a characteristic curled feather rachis and barbs in domestic chickens. Our developmental biology studies identified defects in feather medulla formation, and physical studies revealed that the frizzle feather curls in a stepwise manner. The frizzle gene is transmitted in an autosomal incomplete dominant mode. A whole-genome linkage scan of five pedigrees with 2678 SNPs revealed association of the frizzle locus with a keratin gene-enriched region within the linkage group E22C19W28_E50C23. Sequence analyses of the keratin gene cluster identified a 69 bp in-frame deletion in a conserved region of KRT75, an α-keratin gene. Retroviral-mediated expression of the mutated F cDNA in the wild-type rectrix qualitatively changed the bending of the rachis with some features of frizzle feathers including irregular kinks, severe bending near their distal ends, and substantially higher variations among samples in comparison to normal feathers. These results confirmed KRT75 as the F gene. This study demonstrates the potential of our approach for identifying genetic determinants of feather forms. PMID:22829773

  7. Comparison of Media for the Enumeration of Clostridium perfringens

    PubMed Central

    Harmon, Stanley M.; Kautter, Donald A.; Peeler, James T.

    1971-01-01

    For the enumeration of viable vegetative cells and spores of Clostridium perfringens, noncommercial (laboratory prepared) sulfite-polymyxin-sulfadiazine (SPS) agar, tryptone-sulfite-neomycin (TSN) agar, and Shahidi-Ferguson-perfringens (SFP) agar were statistically compared to SPS agar without antibiotics. The selectivities of these four media were also evaluated on the basis of their ability to inhibit the growth of pure cultures of a variety of other organisms. The average recovery of vegetative cells of 10 strains of C. perfringens with SFP agar was not significantly higher than with SPS agar with 104 organisms per g, but with 106 organisms per g it yielded significantly higher recoveries than SPS agar. TSN agar yielded significantly lower recoveries at both inoculum levels. SFP agar gave significantly higher recoveries of spores than SPS and TSN agars. Average plate counts of spores in SFP agar were 75% as high as in SPS agar without antibiotics, but only 45% of the spores grew in SPS agar and 25% in TSN agar. TSN agar was the most selective of the three media, but the selectivity of SPS agar approached that of TSN agar under the test conditions. SFP agar, which was the least selective of the media, allowed growth to some extent of nearly all of the facultative anaerobes tested. PMID:4324885

  8. Correlations in metal release profiles following sorption by Lemna minor.

    PubMed

    Üçüncü Tunca, Esra; Ölmez, Tolga T; Özkan, Alper D; Altındağ, Ahmet; Tunca, Evren; Tekinay, Turgay

    2016-08-01

    Following the rapid uptake of contaminants in the first few hours of exposure, plants typically attempt to cope with the toxic burden by releasing part of the sorbed material back into the environment. The present study investigates the general trends in the release profiles of different metal(loid)s in the aquatic macrophyte Lemna minor and details the correlations that exist between the release of metal(loid) species. Water samples with distinct contamination profiles were taken from Nilüfer River (Bursa, Turkey), Yeniçağa Lake (Bolu, Turkey), and Beyşehir Lake (Konya, Turkey) and used for release studies; 36 samples were tested in total. Accumulation and release profiles were monitored over five days for 11 metals and a metalloid ((208)Pb, (111)Cd, (52)Cr,(53)Cr,(60)Ni,(63)Cu,(65)Cu,(75)As,(55)Mn, (137)Ba, (27)Al, (57)Fe, (66)Zn,(68)Zn) and correlation, cluster and principal component analyses were employed to determine the factors that affect the release of these elements. Release profiles of the tested metal(loid)s were largely observed to be distinct; however, strong correlations have been observed between certain metal pairs (Cr/Ni, Cr/Cu, Zn/Ni) and principal component analysis was able to separate the metal(loid)s into three well-resolved groups based on their release. PMID:26709546

  9. Arsenic association and stability in long-term disposed arsenic residues.

    PubMed

    Pantuzzo, Fernando L; Ciminelli, Virginia S T

    2010-11-01

    Long-term stability of arsenic residues is investigated by determining arsenic phases remaining in gold mining residues after two decades of impoundment. The residues, generated by arsenic coprecipitation with iron and lime, were disposed of in-lined sites for 9-16 years (pit C) and 16-23 years (pits A and B). Arsenic is present in the residues as As(V) species, predominantly in the form of amorphous iron arsenate (55-75% As(total,) pits A and B; 55-70% As(total), pit C) and sorbed onto amorphous iron-oxyhydroxides (20-33% As(total), pits A and B; 22-37% As(total), pit C). The presence of minor Ca-arsenate phases (undefined composition) and Al-arsenate coprecipitates is also indicated. The passive enrichment of iron in pits A and B, and the relative low concentration of calcium, sulfur and arsenic if compared to those of pit C, suggest that a soluble Ca-arsenate phase (e.g. CaHAsO(4).H(2)O), a fraction of gypsum and As(III) were dissolved along 16-23 years of residue disposal. The presence of As(V) only and excess iron demonstrates the importance of the oxidation state and high Fe/As ratio on long-term stability of arsenic residues. PMID:20696457

  10. Synthesis of novel triazoles and a tetrazole of escitalopram as cholinesterase inhibitors.

    PubMed

    Mehr-un-Nisa; Munawar, Munawar A; Chattha, Fauzia A; Kousar, Samina; Munir, Jawaria; Ismail, Tayaba; Ashraf, Muhammad; Khan, Misbahul A

    2015-09-01

    A novel serie of escitalopram triazoles (60-88) and a tetrazole (89) have been synthesized and subjected to a study to establish the inhibitory potential of these compounds toward acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Some selectivity in inhibition has been observed. The 4-chlorophenyl- (75, IC50, 6.71 ± 0.25 μM) and 2-methylphenyl- (70, IC50, 9.52 ± 0.23 μM) escitalopram triazole derivatives depicted high AChE inhibition, while 2-fluorophenyl- (76, IC50 = 4.52 ± 0.17 μM) and 4-fluorophenyl- (78, IC50 = 5.31 ± 0.43 μM) have found to be excellent BChE inhibitors. It has also been observed that ortho, meta and para substituted electron donating groups increase the inhibition, while electron withdrawing groups reduce the inhibition. Docking analyses of inhibitors with AChE have depicted the binding energies for 70 and 75 as ΔG(bind) -6.42 and -6.93 kcal/mol, respectively, while ligands 76 and 78 have shown the binding affinity ΔG(bind) -9.04 and -8.51 kcal/mol, respectively, for BChE. PMID:26189031

  11. Induction of Oxidative Stress and Antioxidative Mechanisms in Arabidopsis thaliana after Uranium Exposure at pH 7.5

    PubMed Central

    Saenen, Eline; Horemans, Nele; Vanhoudt, Nathalie; Vandenhove, Hildegarde; Biermans, Geert; Van Hees, May; Wannijn, Jean; Vangronsveld, Jaco; Cuypers, Ann

    2015-01-01

    To evaluate the environmental impact of uranium (U) contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress) were exposed for three days to different U concentrations at pH 7.5. In the roots, the increased capacities of ascorbate peroxidase and glutathione reductase indicate an important role for the ascorbate-glutathione cycle during U-induced stress. However, a significant decrease in the ascorbate redox state was observed after exposure to 75 and 100 µM U, indicating that those roots are severely stressed. In accordance with the roots, the ascorbate-glutathione cycle plays an important role in the antioxidative defence systems in A. thaliana leaves exposed to U at pH 7.5 as the ascorbate and glutathione biosynthesis were upregulated. In addition, small inductions of enzymes of the antioxidative defence system were observed at lower U concentrations to counteract the U-induced stress. However, at higher U concentrations it seems that the antioxidative defence system of the leaves collapses as reductions in enzyme activities and gene expression levels were observed. PMID:26042463

  12. Induction of Oxidative Stress and Antioxidative Mechanisms in Arabidopsis thaliana after Uranium Exposure at pH 7.5.

    PubMed

    Saenen, Eline; Horemans, Nele; Vanhoudt, Nathalie; Vandenhove, Hildegarde; Biermans, Geert; Van Hees, May; Wannijn, Jean; Vangronsveld, Jaco; Cuypers, Ann

    2015-01-01

    To evaluate the environmental impact of uranium (U) contamination, it is important to investigate the effects of U at ecologically relevant conditions. Since U speciation, and hence its toxicity, strongly depends on environmental pH, the present study aimed to investigate dose-dependent effects of U at pH 7.5. Arabidopsis thaliana plants (Mouse-ear Cress) were exposed for three days to different U concentrations at pH 7.5. In the roots, the increased capacities of ascorbate peroxidase and glutathione reductase indicate an important role for the ascorbate-glutathione cycle during U-induced stress. However, a significant decrease in the ascorbate redox state was observed after exposure to 75 and 100 µM U, indicating that those roots are severely stressed. In accordance with the roots, the ascorbate-glutathione cycle plays an important role in the antioxidative defence systems in A. thaliana leaves exposed to U at pH 7.5 as the ascorbate and glutathione biosynthesis were upregulated. In addition, small inductions of enzymes of the antioxidative defence system were observed at lower U concentrations to counteract the U-induced stress. However, at higher U concentrations it seems that the antioxidative defence system of the leaves collapses as reductions in enzyme activities and gene expression levels were observed. PMID:26042463

  13. The pH of water from various sources: an overview for recommendation for patients with atopic dermatitis

    PubMed Central

    Kulthanan, Kanokvalai; Varothai, Supenya

    2013-01-01

    Background Patients with atopic dermatitis (AD) have increased susceptibility to irritants. Some patients have questions about types of water for bathing or skin cleansing. Objective We studied the pH of water from various sources to give an overview for physicians to recommend patients with AD. Methods Water from various sources was collected for measurement of the pH using a pH meter and pH-indicator strips. Results Bottled drinking still water had pH between 6.9 and 7.5 while the sparkling type had pH between 4.9 and 5.5. Water derived from home water filters had an approximate pH of 7.5 as same as tap water. Swimming pool water had had pH between 7.2 and 7.5 while seawater had a pH of 8. Normal saline and distilled water had pH of 5.4 and 5.7, respectively. Facial mineral water had pH between 7.5 and 8, while facial makeup removing water had an acidic pH. Conclusion Normal saline, distilled water, bottled sparkling water and facial makeup removing water had similar pH to that of normal skin of normal people. However, other factors including benefits of mineral substances in the water in terms of bacteriostatic and anti-inflammation should be considered in the selection of cleansing water. PMID:23956962

  14. PSIP1/LEDGF: a new gene likely involved in sensorineural progressive hearing loss

    PubMed Central

    Girotto, Giorgia; Scheffer, Déborah I.; Morgan, Anna; Vozzi, Diego; Rubinato, Elisa; Di Stazio, Mariateresa; Muzzi, Enrico; Pensiero, Stefano; Giersch, Anne B.; Corey, David P.; Gasparini, Paolo

    2015-01-01

    Hereditary Hearing Loss (HHL) is an extremely heterogeneous disorder. Approximately 30 out of 80 known HHL genes are associated with autosomal dominant forms. Here, we identified PSIP1/LEDGF (isoform p75) as a novel strong candidate gene involved in dominant HHL. Using exome sequencing we found a frameshift deletion (c.1554_1555del leading to p.E518Dfs*2) in an Italian pedigree affected by sensorineural mild-to-moderate HHL but also showing a variable eye phenotype (i.e. uveitis, optic neuropathy). This deletion led to a premature stop codon (p.T519X) with truncation of the last 12 amino acids. PSIP1 was recently described as a transcriptional co-activator regulated by miR-135b in vestibular hair cells of the mouse inner ear as well as a possible protector against photoreceptor degeneration. Here, we demonstrate that it is ubiquitously expressed in the mouse inner ear. The PSIP1 mutation is associated with a peculiar audiometric slope toward the high frequencies. These findings indicate that PSIP1 likely plays an important role in HHL. PMID:26689366

  15. Nuclear data sheets for A = 75

    SciTech Connect

    Farhan, A. R.; Singh, B.

    1999-04-01

    The experimental nuclear spectroscopic data for known nuclides of mass number 75 (Co, Ni, Cu, Zn, Ga, Ge, As, Se, Br, Kr, Rb, Sr) have been evaluated and presented together with adopted properties for levels and {gamma} rays. No data are yet available for excited states in {sup 75}Co, {sup 75}Ni, {sup 75}Cu, {sup 75}Zn and {sup 75}Sr. Since the 1990 evaluation (90Fa07), new high-spin data are available for {sup 75}Se, {sup 75}Br, {sup 75}Kr and {sup 75}Rb, and new nuclides of {sup 75}Co, {sup 75}Ni and {sup 75}Sr are now identified. No significant new data, since 1990, have been reported for {sup 75}Ga and {sup 75}As. The nuclide {sup 75}Fe has not yet been identified but half-life calculations are reported by 85Bu27 (also 71Pe16 and 97Mo25). This evaluation supersedes earlier evaluations (90Fs07.81Ek02.75Ho17) of A = 75.

  16. Refractive index change in dissociating shocked benzene

    SciTech Connect

    Erskine, D.J.

    1994-06-01

    A calculation is made of the refractive index of a shocked solution of hydrocarbon species and spheroidal carbon particles that would be the dissociation products of benzene. The results is evaluated for benzene shocked to 15 GPa, both for an arbitrary endpoint distribution of products and reactant, and for a specific endpoint distribution suggested by a statistical-mechanical calculation. In the case of diamond particles, the refractive index is predicted to decrease by a small amount (from 1.96 to 1.75) as the dissociation proceeds. In the case of graphite particles of large oblateness, the refractive index could increase significantly through the dissociation (from 1.96 to 2.75 for infinitely oblate platelets). Thus the measurement of the time dependent refractive index through the dissociation of shocked benzene can indicate the morphology of the carbon particulates as well as the time scale for this reaction. We propose using the refractive index as a measure of completion of the dissociation reaction. This would allow a determination of the instantaneous amount of carbon in particulate form, information which is valuable in conjunction with Mie scattering experiments for example.

  17. Quantum path control and isolated attosecond pulse generation with the combination of two circularly polarized laser pulses

    NASA Astrophysics Data System (ADS)

    Xia, Chang-Long; Liu, Xue-Shen

    2013-04-01

    We theoretically investigate the quantum paths of the high-order harmonic generation (HHG) by using a left and a right circularly polarized Gaussian laser pulse with a proper time delay. When the carrier phase of the two pulses is φ1=0, φ2=0.5π, the “gating” structure of the combined laser field disappears. The numerical results indicate that no “gating”-structure-combined laser pulse can control the quantum path. The HHG process is investigated by the semiclassical three-step model that makes use of a finite initial transverse velocity in the elliptically polarized field. For the case of λ1=800 nm, λ2=1600 nm, only a short quantum path contributes to the HHG, and an isolated attosecond pulse would be obtained. For the case of λ2=1600, φ2=0.5π, a supercontinuum spectrum plateau from 180 to 570 eV which includes the water window region is obtained, and attosecond pulses with the duration of about 75 as and a tunable central wavelength could be generated by superposing a bandwidth of 50 eV in the plateau area.

  18. Role of human GRP75 in miRNA mediated regulation of dengue virus replication.

    PubMed

    Kakumani, Pavan Kumar; Medigeshi, Guruprasad R; Kaur, Inderjeet; Malhotra, Pawan; Mukherjee, Sunil K; Bhatnagar, Raj K

    2016-07-15

    In recent times, RNAi has emerged as an important defence system that regulates replication of pathogens in host cells. Many RNAi related host factors especially the host miRNAs play important roles in all intrinsic cellular functions, including viral infection. We have been working on identification of mammalian host factors involved in Dengue virus infection. In the present study, we identified Glucose Regulated Protein 75kDa (GRP75), as a host factor that is associated with dicer complex, in particular with HADHA (trifunctional enzyme subunit alpha, mitochondrial), an auxiliary component of dicer complex. Knockdown of GRP75 by respective siRNAs in Huh-7 cells resulted in the accumulation of dengue viral genomic RNA suggesting a role of GRP75 in regulating dengue virus replication in human cell lines. To elucidate the mode of action of GRP75, we over expressed the protein in Huh-7 cells and analysed the host miRNAs processing. The results revealed that, GRP75 is involved in processing of host miRNA, hsa-mir-126, that down regulates dengue virus replication. These findings suggest a regulatory role of human miRNA pathway especially GRP75 protein and hsa-mir-126 in dengue virus replication. These results thus provide insights into the role of miRNAs and RNAi machinery in dengue life cycle. PMID:27039024

  19. Arabidopsis MYC Transcription Factors Are the Target of Hormonal Salicylic Acid/Jasmonic Acid Cross Talk in Response to Pieris brassicae Egg Extract.

    PubMed

    Schmiesing, André; Emonet, Aurélia; Gouhier-Darimont, Caroline; Reymond, Philippe

    2016-04-01

    Arabidopsis (Arabidopsis thaliana) plants recognize insect eggs and activate the salicylic acid (SA) pathway. As a consequence, expression of defense genes regulated by the jasmonic acid (JA) pathway is suppressed and larval performance is enhanced. Cross talk between defense signaling pathways is common in plant-pathogen interactions, but the molecular mechanism mediating this phenomenon is poorly understood. Here, we demonstrate that egg-induced SA/JA antagonism works independently of the APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) transcription factor ORA59, which controls the ERF branch of the JA pathway. In addition, treatment with egg extract did not enhance expression or stability of JASMONATE ZIM-domain transcriptional repressors, and SA/JA cross talk did not involve JASMONATE ASSOCIATED MYC2-LIKEs, which are negative regulators of the JA pathway. Investigating the stability of MYC2, MYC3, and MYC4, three basic helix-loop-helix transcription factors that additively control jasmonate-related defense responses, we found that egg extract treatment strongly diminished MYC protein levels in an SA-dependent manner. Furthermore, we identified WRKY75 as a novel and essential factor controlling SA/JA cross talk. These data indicate that insect eggs target the MYC branch of the JA pathway and uncover an unexpected modulation of SA/JA antagonism depending on the biological context in which the SA pathway is activated. PMID:26884488

  20. An indirectly pumped terahertz quantum cascade laser with low injection coupling strength operating above 150 K

    NASA Astrophysics Data System (ADS)

    Razavipour, S. G.; Dupont, E.; Fathololoumi, S.; Chan, C. W. I.; Lindskog, M.; Wasilewski, Z. R.; Aers, G.; Laframboise, S. R.; Wacker, A.; Hu, Q.; Ban, D.; Liu, H. C.

    2013-05-01

    We designed and demonstrated a terahertz quantum cascade laser based on indirect pump injection to the upper lasing state and phonon scattering extraction from the lower lasing state. By employing a rate equation formalism and a genetic algorithm, an optimized active region design with four-well GaAs/Al0.25Ga0.75As cascade module was obtained and epitaxially grown. A figure of merit which is defined as the ratio of modal gain versus injection current was maximized at 150 K. A fabricated device with a Au metal-metal waveguide and a top n+ GaAs contact layer lased at 2.4 THz up to 128.5 K, while another one without the top n+ GaAs lased up to 152.5 K (1.3ℏω /kB). The experimental results have been analyzed with rate equation and nonequilibrium Green's function models. A high population inversion is achieved at high temperature using a small oscillator strength of 0.28, while its combination with the low injection coupling strength of 0.85 meV results in a low current. The carefully engineered wavefunctions enhance the quantum efficiency of the device and therefore improve the output optical power even with an unusually low injection coupling strength.

  1. Identification of an evolutionarily conserved domain in human lens epithelium-derived growth factor/transcriptional co-activator p75 (LEDGF/p75) that binds HIV-1 integrase.

    PubMed

    Cherepanov, Peter; Devroe, Eric; Silver, Pamela A; Engelman, Alan

    2004-11-19

    Human lens epithelium-derived growth factor/transcriptional co-activator p75 (LEDGF/p75) protein was recently identified as a binding partner for HIV-1 integrase (IN) in human cells. In this work, we used biochemical and bioinformatic approaches to define the domain organization of LEDGF/p75. Using limited proteolysis and deletion mutagenesis we show that the protein contains a pair of evolutionarily conserved domains, assuming about 35% of its sequence. Whereas the N-terminal PWWP domain had been recognized previously, the second domain is novel. It is comprised of approximately 80 amino acid residues and is both necessary and sufficient for binding to HIV-1 IN. Strikingly, the integrase binding domain (IBD) is not unique to LEDGF/p75, as a second human protein, hepatoma-derived growth factor-related protein 2 (HRP2), contains a homologous sequence. LEDGF/p75 and HRP2 IBDs avidly bound HIV-1 IN in an in vitro GST pull-down assay and each full-length protein potently stimulated HIV-1 IN activity in vitro. LEDGF/p75 and HRP2 are predicted to share a similar domain organization and have an evident evolutionary and likely functional relationship. PMID:15371438

  2. High field nuclear magnetic resonance in transition metal substituted BaFe{sub 2}As{sub 2}

    SciTech Connect

    Garitezi, T. M. Lesseux, G. G.; Rosa, P. F. S.; Adriano, C.; Pagliuso, P. G.; Urbano, R. R.; Reyes, A. P.; Kuhns, P. L.

    2014-05-07

    We report high field {sup 75}As nuclear magnetic resonance (NMR) measurements on Co and Cu substituted BaFe{sub 2}As{sub 2} single crystals displaying same structural/magnetic transition T{sub 0}≃128  K. From our anisotropy studies in the paramagnetic state, we strikingly found virtually identical quadrupolar splitting and consequently the quadrupole frequency ν{sub Q}≃2.57(1)  MHz for both compounds, despite the claim that each Cu delivers 2 extra 3d electrons in BaFe{sub 2}As{sub 2} compared to Co substitution. These results allow us to conclude that a subtle change in the crystallographic structure, particularly in the Fe–As tetrahedra, must be the most probable tuning parameter to determine T{sub 0} in this class of superconductors rather than electronic doping. Furthermore, our NMR data around T{sub 0} suggest coexistence of tetragonal/paramagnetic and orthorhombic/antiferromagnetic phases between the structural and the spin density wave magnetic phase transitions, similarly to what was reported for K-doped BaFe{sub 2}As{sub 2} [Urbano et al., Phys. Rev. Lett. 105, 107001 (2010)].

  3. Identifying the roles of race-based choice and chance in high school friendship network formation

    PubMed Central

    Currarini, Sergio; Jackson, Matthew O.; Pin, Paolo

    2010-01-01

    Homophily, the tendency of people to associate with others similar to themselves, is observed in many social networks, ranging from friendships to marriages to business relationships, and is based on a variety of characteristics, including race, age, gender, religion, and education. We present a technique for distinguishing two primary sources of homophily: biases in the preferences of individuals over the types of their friends and biases in the chances that people meet individuals of other types. We use this technique to analyze racial patterns in friendship networks in a set of American high schools from the Add Health dataset. Biases in preferences and biases in meeting rates are both highly significant in these data, and both types of biases differ significantly across races. Asians and Blacks are biased toward interacting with their own race at rates >7 times higher than Whites, whereas Hispanics exhibit an intermediate bias in meeting opportunities. Asians exhibit the least preference bias, valuing friendships with other types 90% as much as friendships with Asians, whereas Blacks and Hispanics value friendships with other types 55% and 65% as much as same-type friendships, respectively, and Whites fall in between, valuing other-type friendships 75% as much as friendships with Whites. Meetings are significantly more biased in large schools (>1,000 students) than in small schools (<1,000 students), and biases in preferences exhibit some significant variation with the median household income levels in the counties surrounding the schools. PMID:20212129

  4. Arabidopsis MYC Transcription Factors Are the Target of Hormonal Salicylic Acid/Jasmonic Acid Cross Talk in Response to Pieris brassicae Egg Extract1[OPEN

    PubMed Central

    Schmiesing, André; Gouhier-Darimont, Caroline

    2016-01-01

    Arabidopsis (Arabidopsis thaliana) plants recognize insect eggs and activate the salicylic acid (SA) pathway. As a consequence, expression of defense genes regulated by the jasmonic acid (JA) pathway is suppressed and larval performance is enhanced. Cross talk between defense signaling pathways is common in plant-pathogen interactions, but the molecular mechanism mediating this phenomenon is poorly understood. Here, we demonstrate that egg-induced SA/JA antagonism works independently of the APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) transcription factor ORA59, which controls the ERF branch of the JA pathway. In addition, treatment with egg extract did not enhance expression or stability of JASMONATE ZIM-domain transcriptional repressors, and SA/JA cross talk did not involve JASMONATE ASSOCIATED MYC2-LIKEs, which are negative regulators of the JA pathway. Investigating the stability of MYC2, MYC3, and MYC4, three basic helix-loop-helix transcription factors that additively control jasmonate-related defense responses, we found that egg extract treatment strongly diminished MYC protein levels in an SA-dependent manner. Furthermore, we identified WRKY75 as a novel and essential factor controlling SA/JA cross talk. These data indicate that insect eggs target the MYC branch of the JA pathway and uncover an unexpected modulation of SA/JA antagonism depending on the biological context in which the SA pathway is activated. PMID:26884488

  5. [The Dynamics of the Composition of mtDNA Haplotypes of the Ancient Population of the Altai Mountains from the Early Bronze Age (3rd Millennium BC) to the Iron Age (2nd-1st Centuries BC)].

    PubMed

    Gubina, M A; Kulikov, I V; Babenko, V N; Chikisheva, T A; Romaschenko, A G; Voevoda, M I; Molodin, V I

    2016-01-01

    The mtDNA polymorphism in representatives of various archaeological cultures of the Developed Bronze Age, Early Scythian, and Hunnish-Sarmatian periods was analyzed (N = 34). It detected the dominance of Western-Eurasian haplotypes (70.6%) in mtDNA samples from the representatives of the ancient population of the Early Bronze Age--Iron Age on the territory of Altai Mountains. Since the 8th to the 7th centuries BC, a sharp increase was revealed in the Eastern-Eurasian haplogroups A, D, C, andZ (43.75%) as compared to previous cultures (16.7%). The presence of haplotype 223-242-290-319 of haplogroup A8 in Dolgans, Itelmens, Evens, Koryaks, and Yakuts indicates the possible long-term presence of its carriers in areas inhabited by these populations. The prevalence of Western-Eurasian haplotypes is observed not only in the Altai Mountains but also in Central Asia (Kazakhstan) and the South of the Krasnoyarsk Krai. All of the three studied samples from the Western-Eurasian haplogroups were revealed to contain U, H, T, and HV. The ubiquitous presence of haplotypes of haplogroup H and some haplogroups of cluster U (U5al, U4, U2e, and K) in the vast territory from the Yenisei River basin to the Atlantic Ocean may indicate the direction of human settlement, which most likely occurred in the Paleolithic Period from Central Asia. PMID:27183799

  6. Bioethics and why I hope to live beyond age 75 attaining wisdom!: A rebuttal to Dr. Ezekiel Emanuel's 75 age limit.

    PubMed

    Faria, Miguel A

    2015-01-01

    American bioethicists have been providing persuasive arguments for rationing medical care via the theory of the necessary "rational allocation of finite health care resources." Anticipating the need for the drastic rationing of medical care in the U.S. with the implementation of ObamaCare and assisted by various sectors of organized medicine in league with the State, bioethicists have deduced that more ingenious approaches are necessary to convince Americans who have been accustomed to receiving the best medical care that third-party payers are willing to pay for. It is in this context that the individual-based, patient-oriented ethics of Hippocrates, including his fundamental dictum, "First Do No Harm," have to be supplanted by the utilitarian approach promoted by the bioethicists. And today's foremost proponent of the bioethics movement is Dr. Ezekiel Emanuel. This editorial proposes a rational rebuttal to Dr. Emanuel's proposal to limit life expectancy to age 75 as a rational paradigm to a better life. PMID:25789197

  7. Analyzing visual enjoyment of color: using female nude digital Image as example

    NASA Astrophysics Data System (ADS)

    Chin, Sin-Ho

    2014-04-01

    This research adopts three primary colors and their three mixed colors as main color hue variances by changing the background of a female nude digital image. The color saturation variation is selected to 9S as high saturation and 3S as low saturation of PCCS. And the color tone elements are adopted in 3.5 as low brightness, 5.5 as medium brightness for primary color, and 7.5 as low brightness. The water-color brush stroke used for two female body digital images which consisting of a visual pleasant image with elegant posture and another unpleasant image with stiff body language, is to add the visual intimacy. Results show the brightness of color is the main factor impacting visual enjoyment, followed by saturation. Explicitly, high-brightness with high saturation gains the highest rate of enjoyment, high-saturation medium brightness (primary color) the second, and high-brightness with low saturation the third, and low-brightness with low saturation the least.

  8. Electron spin resonance study of point defects in thermal GaAs/GaAs-oxide structures

    NASA Astrophysics Data System (ADS)

    Nguyen, S.; Afanas'ev, V. V.; Stesmans, A.

    2012-12-01

    In an attempt to atomically assess interface and oxide-related point defects, a first basic multifrequency low-temperature electron spin resonance study has been carried out on semi-insulating (Fe compensated) GaAs/oxide structures, implying both powders and (100)GaAs/oxide slices, thermally grown in the range Tox=350-615 °C. Various spectra are observed: As for powders, this includes the 4-line EL2 defect spectrum centered at g~2.043 and characterized by the isotropic hyperfine constant Aiso~ 910 G, ascribed to the 75AsGa+ antisite defect. Observed in freshly crushed powder, it substantially increases in density with oxidation, in line with theoretical expectation; A maximum appears reached for at Tox~440 °C. It is not observed in the parent c-GaAs wafer. A second isotropic signal is observed at g~1.937 in powders for Tox in the range 510-615 °C, but only after additional VUV irradiation; it may correspond to As clusters. In bulk (100)GaAs, we observe the 5-branch spectrum of substitutional Fe impurities (spin S=5/2) in GaAs, with inferred crystal field constant a ≈ 360 G, well in line with previous observations. The results are discussed within the framework of advanced theoretical interface and defect models and previous experimental assessment.

  9. Microanalysis of metals in coal and coal ash using the Stanford/USGS SHRIMP-RG ion microprobe[Sensitive High-Resolution Ion MicroProbe--Reversed Geometry

    SciTech Connect

    Kolker, A.; Zielinski, R.A.; Wooden, J.L.; Persing, H.M.

    2000-07-01

    The capability of the SHRIMP-RG ion microprobe to determine the micro-distribution of selected trace metals in coal and coal ash was investigated as part of a larger study of the behavior of air toxic metals during coal combustion. Initial work, reported here, used the oxygen (O) ion source for in-situ determination of Cr and other elements in illite/smectite, a major inorganic constituent of the coals analyzed. This was followed by tests of the applicability of the SHRIMP-RG for trace-metal analysis of fly ash from a Kentucky power plant, in which U and Pb concentrations were determined in the coarse (63--150 micrometer) fraction of the fly ash. The results for illite/smectite confirm that it is an important source of chromium that may be emitted during coal burning. Results for fly-ash show that the {sup 75}As peak is resolvable from potential interferences in glass standards and partially resolvable in the fly ash, indicating that the SHRIMP-RG may be useful in characterizing the distribution of leachable metals condensed on fly ash surfaces.

  10. Efficiency of extracting stereo-driven object motions

    PubMed Central

    Jain, Anshul; Zaidi, Qasim

    2013-01-01

    Most living things and many nonliving things deform as they move, requiring observers to separate object motions from object deformations. When the object is partially occluded, the task becomes more difficult because it is not possible to use two-dimensional (2-D) contour correlations (Cohen, Jain, & Zaidi, 2010). That leaves dynamic depth matching across the unoccluded views as the main possibility. We examined the role of stereo cues in extracting motion of partially occluded and deforming three-dimensional (3-D) objects, simulated by disk-shaped random-dot stereograms set at randomly assigned depths and placed uniformly around a circle. The stereo-disparities of the disks were temporally oscillated to simulate clockwise or counterclockwise rotation of the global shape. To dynamically deform the global shape, random disparity perturbation was added to each disk's depth on each stimulus frame. At low perturbation, observers reported rotation directions consistent with the global shape, even against local motion cues, but performance deteriorated at high perturbation. Using 3-D global shape correlations, we formulated an optimal Bayesian discriminator for rotation direction. Based on rotation discrimination thresholds, human observers were 75% as efficient as the optimal model, demonstrating that global shapes derived from stereo cues facilitate inferences of object motions. To complement reports of stereo and motion integration in extrastriate cortex, our results suggest the possibilities that disparity selectivity and feature tracking are linked, or that global motion selective neurons can be driven purely from disparity cues. PMID:23325345

  11. Bioavailability of lead in oysters fed to young Japanese quail

    SciTech Connect

    Stone, C.L.; Spivey Fox, M.R.; Hogye, K.S.

    1981-12-01

    The presence of lead in atmospheric particulates, soil, and seawater reflects the input of both domestic and industrial wastes. Because bivalves can concentrate large quantities of heavy metals, particularly lead, consumption of their meat may be a potential risk. The relative bioavailability of lead physiologicaly incorporated into oyster meat was investigated. Day-old Japanese quail were fed purified diets with three levels of lead added as either lead acetate, freeze-dried lead-dosed oyster, or lead acetate plus freeze-dried control oyster for 2 weeks. Feeding lead from any source had little or no effect on body weight, hemoglobin, hematocrit, or percentage ash in the tibia. The concentration of lead in tibia at each level of dietary lead for each type of diet was different from those for all other levels of dietary lead. Slope-ratio analysis of the data showed that lead intrinsically incorporated into oyster meat was 69-75% as bioavailable as lead in lead acetate at levels between 25 and 100 ppm dietary lead. The combinations of (1) control oyster meat with lead acetate and (2) lead acetate with copper and zinc levels equal to those in oyster meat gave responses similar to those of the lead-dosed oyster groups. Although these data showed lower bioavailability of lead in oyster meat as compared with lead acetate, the intercept of the lines at 25 ppm dietary lead suggests that the relative bioavailability may be reserved at lower levels of lead intake.

  12. Polarizabilities and van der Waals C6 coefficients of fullerenes from an atomistic electrodynamics model: Anomalous scaling with number of carbon atoms

    NASA Astrophysics Data System (ADS)

    Saidi, Wissam A.; Norman, Patrick

    2016-07-01

    The van der Waals C6 coefficients of fullerenes are shown to exhibit an anomalous dependence on the number of carbon atoms N such that C6 ∝ N2.2 as predicted using state-of-the-art quantum mechanical calculations based on fullerenes with small sizes, and N2.75 as predicted using a classical-metallic spherical-shell approximation of the fullerenes. We use an atomistic electrodynamics model where each carbon atom is described by a polarizable object to extend the quantum mechanical calculations to larger fullerenes. The parameters of this model are optimized to describe accurately the static and complex polarizabilities of the fullerenes by fitting against accurate ab initio calculations. This model shows that C6 ∝ N2.8, which is supportive of the classical-metallic spherical-shell approximation. Additionally, we show that the anomalous dependence of the polarizability on N is attributed to the electric charge term, while the dipole-dipole term scales almost linearly with the number of carbon atoms.

  13. Fibulin-1C, C1 Esterase Inhibitor and Glucose Regulated Protein 75 Interact with the CREC Proteins, Calumenin and Reticulocalbin

    PubMed Central

    Aune Westergaard Hansen, Gry; Ludvigsen, Maja; Jacobsen, Christian; Cangemi, Claudia; Melholt Rasmussen, Lars; Vorum, Henrik; Honoré, Bent

    2015-01-01

    Affinity purification, immunoprecipitation, gel electrophoresis and mass spectrometry were used to identify fibulin-1C, C1 esterase inhibitor and glucose regulated protein 75, grp75, as binding partners of the CREC proteins, calumenin and reticulocalbin. Surface plasmon resonance was used to verify the interaction of all three proteins with each of the CREC proteins. Fibulin-1C interacts with calumenin and reticulocalbin with an estimated dissociation constant around 50-60 nM. The interaction, at least for reticulocalbin, was not dependent upon the presence of Ca2+. C1 esterase inhibitor interacted with both proteins with an estimated dissociation constant at 1 μM for reticulocalbin and 150 nM for calumenin. The interaction, at least for calumenin, was dependent upon the presence of Ca2+ with strong interaction at 3.5 mM while no detectable interaction could be found at 0.1 mM. Grp75 binds with an affinity of approximately 3-7 nM with reticulocalbin as well as with calumenin. These interactions suggest functional participation of the CREC proteins in chaperone activity, cell proliferation and transformation, cellular aging, haemostasis and thrombosis as well as modulation of the complement system in fighting bacterial infection. PMID:26161649

  14. Sequence and transcriptional analysis of the genes responsible for curdlan biosynthesis in Agrobacterium sp. ATCC 31749 under simulated dissolved oxygen gradients conditions.

    PubMed

    Zhang, Hong-Tao; Zhan, Xiao-Bei; Zheng, Zhi-Yong; Wu, Jian-Rong; Yu, Xiao-Bin; Jiang, Yun; Lin, Chi-Chung

    2011-07-01

    Expression at the mRNA level of ten selected genes in Agrobacterium sp. ATCC 31749 under various dissolved oxygen (DO) levels during curdlan fermentation related to electron transfer chain (ETC), tricarboxylic acid (TCA) cycle, peptidoglycan/lipopolysaccharide biosynthesis, and uridine diphosphate (UDP)-glucose biosynthesis were determined by qRT-PCR. Experiments were performed at DO levels of 30%, 50%, and 75%, as well as under low-oxygen conditions. The effect of high cell density on transcriptional response of the above genes under low oxygen was also studied. Besides cytochrome d (cyd A), the transcription levels of all the other genes were increased at higher DO and reached maximum at 50% DO. Under 75% DO, the transcriptional levels of all the genes were repressed. In addition, transcription levels of icd, sdh, cyo A, and fix N genes did not exhibit significant fluctuation with high cell density culture under low oxygen. These results suggested a mechanism for DO regulation of curdlan synthesis through regulation of transcriptional levels of ETCs, TCA, and UDP-glucose synthesis genes during curdlan fermentation. To our knowledge, this is the first report that DO concentration apparently regulates curdlan biosynthesis in Agrobacterium sp. ATCC 31749 providing essential lead for the optimization of the fermentation at the industrial scale. PMID:21472535

  15. A Novel Microaneurysms Detection Method Based on Local Applying of Markov Random Field.

    PubMed

    Ganjee, Razieh; Azmi, Reza; Moghadam, Mohsen Ebrahimi

    2016-03-01

    Diabetic Retinopathy (DR) is one of the most common complications of long-term diabetes. It is a progressive disease and by damaging retina, it finally results in blindness of patients. Since Microaneurysms (MAs) appear as a first sign of DR in retina, early detection of this lesion is an essential step in automatic detection of DR. In this paper, a new MAs detection method is presented. The proposed approach consists of two main steps. In the first step, the MA candidates are detected based on local applying of Markov random field model (MRF). In the second step, these candidate regions are categorized to identify the correct MAs using 23 features based on shape, intensity and Gaussian distribution of MAs intensity. The proposed method is evaluated on DIARETDB1 which is a standard and publicly available database in this field. Evaluation of the proposed method on this database resulted in the average sensitivity of 0.82 for a confidence level of 75 as a ground truth. The results show that our method is able to detect the low contrast MAs with the background while its performance is still comparable to other state of the art approaches. PMID:26779642

  16. The chicken frizzle feather is due to an α-keratin (KRT75) mutation that causes a defective rachis.

    PubMed

    Ng, Chen Siang; Wu, Ping; Foley, John; Foley, Anne; McDonald, Merry-Lynn; Juan, Wen-Tau; Huang, Chih-Jen; Lai, Yu-Ting; Lo, Wen-Sui; Chen, Chih-Feng; Leal, Suzanne M; Zhang, Huanmin; Widelitz, Randall B; Patel, Pragna I; Li, Wen-Hsiung; Chuong, Cheng-Ming

    2012-01-01

    Feathers have complex forms and are an excellent model to study the development and evolution of morphologies. Existing chicken feather mutants are especially useful for identifying genetic determinants of feather formation. This study focused on the gene F, underlying the frizzle feather trait that has a characteristic curled feather rachis and barbs in domestic chickens. Our developmental biology studies identified defects in feather medulla formation, and physical studies revealed that the frizzle feather curls in a stepwise manner. The frizzle gene is transmitted in an autosomal incomplete dominant mode. A whole-genome linkage scan of five pedigrees with 2678 SNPs revealed association of the frizzle locus with a keratin gene-enriched region within the linkage group E22C19W28_E50C23. Sequence analyses of the keratin gene cluster identified a 69 bp in-frame deletion in a conserved region of KRT75, an α-keratin gene. Retroviral-mediated expression of the mutated F cDNA in the wild-type rectrix qualitatively changed the bending of the rachis with some features of frizzle feathers including irregular kinks, severe bending near their distal ends, and substantially higher variations among samples in comparison to normal feathers. These results confirmed KRT75 as the F gene. This study demonstrates the potential of our approach for identifying genetic determinants of feather forms. PMID:22829773

  17. Resonance Raman scattering in GaAs-AlxGa1-xAs superlattices: Impurity-induced Fröhlich-interaction scattering

    NASA Astrophysics Data System (ADS)

    Kauschke, W.; Sood, A. K.; Cardona, M.; Ploog, K.

    1987-07-01

    We report measurements of Raman scattering from LO phonons in resonance with quasi-two-dimensional excitons in a 104-Å GaAs-125-Å Al0.25Ga0.75As superlattice. Incoming and outgoing resonances are observed at discrete excitons formed from first and second conduction and valence subbands. As already pointed out by Zucker et al., the resonant Raman profile shows a stronger outgoing resonance as compared with the incoming one. We present a quantitative explanation of the observed asymmetry of both resonance channels by invoking the impurity-induced intraband Fröhlich scattering mechanism, an effect also observed in bulk semiconductors. This analysis differs from that of Zucker et al., which was based on the details of the quantized quasi-two-dimensional excitons. We believe that the latter mechanism may explain resonance asymmetry for a special range of superlattice parameters, while the one proposed here should be more general, extending all the way to the two-dimensional case.

  18. Polarizabilities and van der Waals C6 coefficients of fullerenes from an atomistic electrodynamics model: Anomalous scaling with number of carbon atoms.

    PubMed

    Saidi, Wissam A; Norman, Patrick

    2016-07-14

    The van der Waals C6 coefficients of fullerenes are shown to exhibit an anomalous dependence on the number of carbon atoms N such that C6 ∝ N(2.2) as predicted using state-of-the-art quantum mechanical calculations based on fullerenes with small sizes, and N(2.75) as predicted using a classical-metallic spherical-shell approximation of the fullerenes. We use an atomistic electrodynamics model where each carbon atom is described by a polarizable object to extend the quantum mechanical calculations to larger fullerenes. The parameters of this model are optimized to describe accurately the static and complex polarizabilities of the fullerenes by fitting against accurate ab initio calculations. This model shows that C6 ∝ N(2.8), which is supportive of the classical-metallic spherical-shell approximation. Additionally, we show that the anomalous dependence of the polarizability on N is attributed to the electric charge term, while the dipole-dipole term scales almost linearly with the number of carbon atoms. PMID:27421409

  19. Trade-off study on the power capacity of a prototype SFR in Korea

    SciTech Connect

    Baek, M. H.; Kim, S. J.; Yoo, J.; Bae, I. H.

    2012-07-01

    The major roles of a prototype SFR are to provide irradiation test capability for the fuel and structure materials, and to obtain operational experiences of systems. Due to a compromise between the irradiation capability and construction costs, the power level should be properly determined. In this paper, a trade-off study on the power level of the prototype SFR was performed from a neutronics viewpoint. To select candidate cores, the parametric study of pin diameters was estimated using 20 wt.% uranium fuel. The candidate cores of different power levels, 125 MWt, 250 MWt, 400 MWt, and 500 MWt, were compared with the 1500 MWt reference core. The resulting core performance and economic efficiency indices became insensitive to the power at about 400-500 MWt and sharply deteriorated at about 125-250 MWt with decreasing core sizes. Fuel management scheme, TRU core performance comparing with uranium core, and sodium void reactivity were also evaluated with increasing power levels. It is found that increasing the number of batches showed higher burnup performance and economic efficiency. However, increasing the cycle length showed the trends in lower economic efficiency. Irradiation performance of TRU and enriched TRU cores was improved about 20 % and 50 %, respectively. The maximum sodium void reactivity of 5.2$ was confirmed less than the design limit of 7.5$. As a result, the power capacity of the prototype SFR should not be less than 250 MWt and would be appropriate at {approx} 500 MWt considering the performance and economic efficiency. (authors)

  20. Analysis of the transient response of nuclear spins in GaAs with/without nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Rasly, Mahmoud; Lin, Zhichao; Yamamoto, Masafumi; Uemura, Tetsuya

    2016-05-01

    As an alternative to studying the steady-state responses of nuclear spins in solid state systems, working within a transient-state framework can reveal interesting phenomena. The response of nuclear spins in GaAs to a changing magnetic field was analyzed based on the time evolution of nuclear spin temperature. Simulation results well reproduced our experimental results for the transient oblique Hanle signals observed in an all-electrical spin injection device. The analysis showed that the so called dynamic nuclear polarization can be treated as a cooling tool for the nuclear spins: It works as a provider to exchange spin angular momentum between polarized electron spins and nuclear spins through the hyperfine interaction, leading to an increase in the nuclear polarization. In addition, a time-delay of the nuclear spin temperature with a fast sweep of the external magnetic field produces a possible transient state for the nuclear spin polarization. On the other hand, the nuclear magnetic resonance acts as a heating tool for a nuclear spin system. This causes the nuclear spin temperature to jump to infinity: i.e., the average nuclear spins along with the nuclear field vanish at resonant fields of 75As, 69Ga and 71Ga, showing an interesting step-dip structure in the oblique Hanle signals. These analyses provide a quantitative understanding of nuclear spin dynamics in semiconductors for application in future computation processing.

  1. Enhanced nutrient removal in three types of step feeding process from municipal wastewater.

    PubMed

    Peng, Yongzhen; Ge, Shijian

    2011-06-01

    An anoxic/oxic step feeding process was improved to enhance nutrient removal by reconfiguring the process into (1) anaerobic/anoxic/oxic step feeding process or (2) modified University of Capetown (UCT) step feeding process. Enhanced nitrogen and phosphorus removal and optimized organics utilization were obtained simultaneously in the modified UCT type with both internal and sludge recycle ratios of 75% as well as anaerobic/anoxic/oxic volume ratio of 1:3:6. Specifically, the UCT configuration and optimized operational conditions lead to the enrichment of denitrifying phosphorus removal microorganisms and achieved improved anaerobic P-release and anoxic P-uptake activities, which were beneficial to the denitrifying phosphorus removal activities and removal efficiencies. Due to high mixed liquor suspended solid and uneven distributed dissolved oxygen, 35% of total nitrogen was eliminated through simultaneous nitrification and denitrification process in aerobic zones. Moreover, 62 ± 6% of influent chemical oxygen demands was involved in the denitrification or phosphorus release processes. PMID:21474307

  2. Relationships between preclinical course grades and standardized exam performance.

    PubMed

    Hu, Yinin; Martindale, James R; LeGallo, Robin D; White, Casey B; McGahren, Eugene D; Schroen, Anneke T

    2016-05-01

    Success in residency matching is largely contingent upon standardized exam scores. Identifying predictors of standardized exam performance could promote primary intervention and lead to design insights for preclinical courses. We hypothesized that clinically relevant courses with an emphasis on higher-order cognitive understanding are most strongly associated with performance on United States Medical Licensing Examination Step exams and National Board of Medical Examiners clinical subject exams. Academic data from students between 2007 and 2012 were collected. Preclinical course scores and standardized exam scores were used for statistical modeling with multiple linear regression. Preclinical courses were categorized as having either a basic science or a clinical knowledge focus. Medical College Admissions Test scores were included as an additional predictive variable. The study sample comprised 795 graduating medical students. Median score on Step 1 was 234 (interquartile range 219-245.5), and 10.2 % (81/795) scored lower than one standard deviation below the national average (205). Pathology course score was the strongest predictor of performance on all clinical subject exams and Step exams, outperforming the Medical College Admissions Test in strength of association. Using Pathology score <75 as a screening metric for Step 1 score <205 results in sensitivity and specificity of 37 and 97 %, respectively, and a likelihood ratio of 11.9. Performance in Pathology, a clinically relevant course with case-based learning, is significantly related to subsequent performance on standardized exams. Multiple linear regression is useful for identifying courses that have potential as risk stratifiers. PMID:26363626

  3. Emergence of Orbital Nematicity in the Tetragonal Phase of BaFe2(As1-xPx)2

    NASA Astrophysics Data System (ADS)

    Iye, Tetsuya; Julien, Marc-Henri; Mayaffre, Hadrien; Horvatić, Mladen; Berthier, Claude; Ishida, Kenji; Ikeda, Hiroaki; Kasahara, Shigeru; Shibauchi, Takasada; Matsuda, Yuji

    2015-04-01

    We report on 75As-NMR measurements in single crystalline BaFe2(As0.96P0.04)2 for magnetic fields parallel to the orthorhombic [110]o and [100]o directions above the structural transition temperature TS ≃ 121 K. A large difference in the linewidth between the two field directions reveals in-plane anisotropy of the electric field gradient, even in the tetragonal phase. This provides microscopic evidence of population imbalance between As-4px and 4py orbitals, which reaches |nx - ny|/|nx + ny| ˜ 15% at T → TS and is a natural consequence of the orbital ordering of Fe-3dxz and dyz electrons. Surprisingly, this orbital polarization is found to be already static near room temperature, suggesting that it arises from the pinning of anisotropic orbital fluctuations by disorder. The effect is found to be stronger below ˜160 K, which coincides with the appearance of nematicity in previous torque and photoemission measurements. These results impose strong constraints on microscopic models of the nematic state.

  4. Indium segregation during III–V quantum wire and quantum dot formation on patterned substrates

    SciTech Connect

    Moroni, Stefano T.; Dimastrodonato, Valeria; Chung, Tung-Hsun; Juska, Gediminas; Gocalinska, Agnieszka; Pelucchi, Emanuele; Vvedensky, Dimitri D.

    2015-04-28

    We report a model for metalorganic vapor-phase epitaxy on non-planar substrates, specifically V-grooves and pyramidal recesses, which we apply to the growth of InGaAs nanostructures. This model—based on a set of coupled reaction-diffusion equations, one for each facet in the system—accounts for the facet-dependence of all kinetic processes (e.g., precursor decomposition, adatom diffusion, and adatom lifetimes) and has been previously applied to account for the temperature-, concentration-, and temporal-dependence of AlGaAs nanostructures on GaAs (111)B surfaces with V-grooves and pyramidal recesses. In the present study, the growth of In{sub 0.12}Ga{sub 0.88}As quantum wires at the bottom of V-grooves is used to determine a set of optimized kinetic parameters. Based on these parameters, we have modeled the growth of In{sub 0.25}Ga{sub 0.75}As nanostructures formed in pyramidal site-controlled quantum-dot systems, successfully producing a qualitative explanation for the temperature-dependence of their optical properties, which have been reported in previous studies. Finally, we present scanning electron and cross-sectional atomic force microscopy images which show previously unreported facetting at the bottom of the pyramidal recesses that allow quantum dot formation.

  5. The significance of autoantibodies to DFS70/LEDGFp75 in health and disease: integrating basic science with clinical understanding.

    PubMed

    Ochs, Robert L; Mahler, Michael; Basu, Anamika; Rios-Colon, Leslimar; Sanchez, Tino W; Andrade, Luis E; Fritzler, Marvin J; Casiano, Carlos A

    2016-08-01

    Antinuclear autoantibodies (ANAs) displaying the nuclear dense fine speckled immunofluorescence (DFS-IIF) pattern in HEp-2 substrates are commonly observed in clinical laboratory referrals. They target the dense fine speckled autoantigen of 70 kD (DFS70), most commonly known as lens epithelium-derived growth factor p75 (LEDGFp75). Interesting features of these ANAs include their low frequency in patients with systemic autoimmune rheumatic diseases (SARD), elevated prevalence in apparently healthy individuals, IgG isotype, strong trend to occur as the only ANA specificity in serum, and occurrence in moderate to high titers. These autoantibodies have also been detected at varied frequencies in patients with diverse non-SARD inflammatory and malignant conditions such as atopic diseases, asthma, eye diseases, and prostate cancer. These observations have recently stimulated vigorous research on their clinical and biological significance. Some studies have suggested that they are natural, protective antibodies that could serve as biomarkers to exclude a SARD diagnosis. Other studies suggest that they might be pathogenic in certain contexts. The emerging role of DFS70/LEDGFp75 as a stress protein relevant to human acquired immunodeficiency syndrome, cancer, and inflammation also points to the possibility that these autoantibodies could be sensors of cellular stress and inflammation associated with environmental factors. In this comprehensive review, we integrate our current knowledge of the biology of DFS70/LEDGFp75 with the clinical understanding of its autoantibodies in the contexts of health and disease. PMID:26088181

  6. Noribogaine is a G-protein biased κ-opioid receptor agonist.

    PubMed

    Maillet, Emeline L; Milon, Nicolas; Heghinian, Mari D; Fishback, James; Schürer, Stephan C; Garamszegi, Nandor; Mash, Deborah C

    2015-12-01

    Noribogaine is the long-lived human metabolite of the anti-addictive substance ibogaine. Noribogaine efficaciously reaches the brain with concentrations up to 20 μM after acute therapeutic dose of 40 mg/kg ibogaine in animals. Noribogaine displays atypical opioid-like components in vivo, anti-addictive effects and potent modulatory properties of the tolerance to opiates for which the mode of action remained uncharacterized thus far. Our binding experiments and computational simulations indicate that noribogaine may bind to the orthosteric morphinan binding site of the opioid receptors. Functional activities of noribogaine at G-protein and non G-protein pathways of the mu and kappa opioid receptors were characterized. Noribogaine was a weak mu antagonist with a functional inhibition constants (Ke) of 20 μM at the G-protein and β-arrestin signaling pathways. Conversely, noribogaine was a G-protein biased kappa agonist 75% as efficacious as dynorphin A at stimulating GDP-GTP exchange (EC50=9 μM) but only 12% as efficacious at recruiting β-arrestin, which could contribute to the lack of dysphoric effects of noribogaine. In turn, noribogaine functionally inhibited dynorphin-induced kappa β-arrestin recruitment and was more potent than its G-protein agonistic activity with an IC50 of 1 μM. This biased agonist/antagonist pharmacology is unique to noribogaine in comparison to various other ligands including ibogaine, 18-MC, nalmefene, and 6'-GNTI. We predict noribogaine to promote certain analgesic effects as well as anti-addictive effects at effective concentrations>1 μM in the brain. Because elevated levels of dynorphins are commonly observed and correlated with anxiety, dysphoric effects, and decreased dopaminergic tone, a therapeutically relevant functional inhibition bias to endogenously released dynorphins by noribogaine might be worthy of consideration for treating anxiety and substance related disorders. PMID:26302653

  7. Tracing Back Clinical Campylobacter jejuni in the Northwest of Italy and Assessing Their Potential Source.

    PubMed

    Di Giannatale, Elisabetta; Garofolo, Giuliano; Alessiani, Alessandra; Di Donato, Guido; Candeloro, Luca; Vencia, Walter; Decastelli, Lucia; Marotta, Francesca

    2016-01-01

    Food-borne campylobacteriosis is caused mainly by the handling or consumption of undercooked chicken meat or by the ingestion of contaminated raw milk. Knowledge about the contributions of different food sources to gastrointestinal disease is fundamental to prioritize food safety interventions and to establish proper control strategies. Assessing the genetic diversity among Campylobacter species is essential to our understanding of their epidemiology and population structure. We molecularly characterized 56 Campylobacter jejuni isolates (31 from patients hospitalized with gastroenteritis, 17 from raw milk samples, and 8 from chicken samples) using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) in order to trace the source of the disease. We also used a population genetic approach to investigate the source of the human cases from six different reservoirs of infection. MLST identified 25 different sequence types and 11 clonal complexes (CCs) (21, 658, 206, 353, 443, 48, 61, 257, 1332, 354, 574) and these included several alleles not cited previously in the PubMLST international database. The most prevalent CCs were 21, 206, and 354. PFGE showed 34 pulsotypes divided between 28 different clusters. At the fine scale, by means of PFGE and MLST, only two human cases were linked to raw milk, while one case was linked to chicken meat. The investigation revealed the presence of several genotypes among the human isolates, which probably suggests multiple foci for the infections. Finally, the source attribution model we used revealed that most cases were attributed to chicken (69.75%) as the main reservoir in Italy, followed to a lesser extent by the following sources: cattle (8.25%); environment (6.28%); wild bird (7.37%); small ruminant (5.35%), and pork (2.98%). This study confirms the importance of correlating epidemiological investigations with molecular epidemiological data to better understand the dynamics of infection. PMID:27379033

  8. Efficacy and safety of dulaglutide in patients with type 2 diabetes: a meta-analysis and systematic review.

    PubMed

    Zhang, Lin; Zhang, Mei; Zhang, Yuwei; Tong, Nanwei

    2016-01-01

    A meta-analysis was conducted to assess the clinical efficacy and safety of dulaglutide in patients with type 2 diabetes mellitus (T2DM). Medline, Embase, Cochrane Library and www. clinicaltrials. gov (up to February 15(th), 2015) were searched. Randomized controlled trials comparing dulaglutide to other drugs for T2DM were collected. Twelve RCTs were included, and the overall bias was low. As the monotherapy, compared with control (placebo, metformin and liraglutide), dulaglutide resulted in a significant reduction in HbA1c (WMD, -0.68%; 95% CI, -0.95 to -0.40), FPG (WMD, -0.90 mmol/L; 95% CI, -1.28 to -0.52), a similar risk of hypoglycemia (7.8% vs. 10.6%), less body weight loss (WMD, 0.51 kg; 95% CI, 0.27 to 0.75). As an add-on intervention with oral antihyperglycemic medication (OAM) and insulin, compared with control (placebo, sitagliptin, exenatide, liraglutide and glargine), dulaglutide lowered HbA1c (WMD, -0.51%; 95% CI, -0.68 to -0.35) and body weight significantly (WMD, -1.30 kg, 95% CI, -1.85 to -1.02) notably, and elicited a similar reduction in FPG (WMD, -0.19 mmol/L; 95% CI, -1.20 to 0.82), an similar incidence of hypoglycemia (24.5% vs. 24.5%). This meta-analysis revealed the use of dulaglutide as a monotherapy or an add-on to OAM and lispro appeared to be effective and safe for adults with T2DM. PMID:26742577

  9. The Effect of Impacts on the Early Martian Climate

    NASA Technical Reports Server (NTRS)

    Colaprete, A.; Haberle, R. M.; Segura, T. L.; Toon, O. B.; Zahnle, K.

    2004-01-01

    The first images returned by the Mariner 7 spacecraft of the Martian surface showed a landscape heavily scared by impacts. Mariner 9 imaging revealed geomorphic features including valley networks and outflow channels that suggest liquid water once flowed at the surface of Mars. Further evidence for water erosion and surface modification has come from the Viking Spacecraft, Mars Pathfinder, Mars Global Surveyor's (MGS) Mars Orbiter Camera (MOC), and Mars Odyssey's THEMIS instrument. In addition to network channels, this evidence includes apparent paleolake beds, fluvial fans and sedimentary layers. The estimated erosion rates necessary to explain the observed surface morphologies present a conundrum. The rates of erosion appear to be highest when the early sun was fainter and only 75% as luminous as it is today. All of this evidence points to a very different climate than what exists on Mars today. The most popular paradigm for the formation of the valley networks is that Mars had at one time a warm (T average > 273), wetter and stable climate. Possible warming mechanisms have included increased surface pressures, carbon dioxide clouds and trace greenhouse gasses. Yet to date climate models have not been able to produce a continuously warm and wet early Mars. The rates of erosion appear to correlate with the rate at which Mars was impacted thus an alternate possibility is transient warm and wet conditions initiated by large impacts. It is widely accepted that even relatively small impacts (approx. 10 km) have altered the past climate of Earth to such an extent as to cause mass extinctions. Mars has been impacted with a similar distribution of objects. The impact record at Mars is preserved in the abundance of observable craters on it surface. Impact induced climate change must have occurred on Mars.

  10. A 50% reduction in the Psoriasis Area and Severity Index (PASI 50) is a clinically significant endpoint in the assessment of psoriasis.

    PubMed

    Carlin, Christopher S; Feldman, Steven R; Krueger, James G; Menter, Alan; Krueger, Gerald G

    2004-06-01

    A 75% reduction in the Psoriasis Area and Severity Index (PASI) score (PASI 75) is the current benchmark of primary endpoints for most clinical trials of psoriasis. Many consider this endpoint to be too stringent as it places potentially useful therapies at risk of failing to demonstrate efficacy. We hypothesized that a 50% reduction in the PASI score (PASI 50) represents a meaningful change in a person's life and thus is a better primary endpoint. To test this hypothesis, we analyzed PASI scores, quality of life (QoL) data, and desired re-treatment scores from a number of clinical trials in addition to studying individual elements that make up the PASI. This analysis shows (1). the PASI score is not linearly reflective of psoriasis severity (eg, a reduction in area of 95% without a change in redness, scaliness, and induration translates to only a 66% reduction in PASI); conversely, a drop in erythema, scale, and induration from an average of 3 to 1 would not lead to a 75% reduction in PASI; (2). treatment with methotrexate, an effective psoriasis therapy, more frequently reaches PASI 50 than PASI 75 as evidenced by a recent open trial in which 63% of patients achieved PASI 50 versus 26% achieving PASI 75; (3). improvement in QoL exists at PASI 50, using the Dermatology Quality of Life Index, as documented in several recently completed large clinical trials; (4). patients achieving PASI 75 frequently defer therapy until they are well below PASI 50; a clinical trial where retreatment was patient initiated showed patients did not re-treat until their PASI dropped to an average of 20% improvement from baseline; and (5). effective, meaningful therapies are consistently differentiated from placebo at PASI 50 as evidenced by histologic and photographic parameters of clinical trials of alefacept, efalizumab, and etanercept. We conclude that PASI 50 equates to a clinically meaningful improvement in psoriasis and represents a discerning primary endpoint. PMID:15153885

  11. Biogeography of Rhizobium radiobacter and distribution of associated temperate phages in deep subseafloor sediments

    PubMed Central

    Engelhardt, Tim; Sahlberg, Monika; Cypionka, Heribert; Engelen, Bert

    2013-01-01

    Bacteriophages might be the main ‘predators' in the marine deep subsurface and probably have a major impact on indigenous microbial communities. To identify their function within this habitat, we have determined their abundance and distribution along the sediment columns of two continental margin and two open ocean sites that were recovered during Leg 201 of the Ocean Drilling Program. For all investigated sites, viral abundance followed the total cell numbers with a virus-to-cell ratio between 1 and 10 in the upper 100 mbsf (meters below seafloor). An increasing ratio of about 20 in deeper layers indicated an ongoing viral production in up to 11 Ma old sediments. We have used Rhizobium radiobacter as the most frequently isolated organism from the deep subsurface with a high in situ abundance to identify the frequency of associated rhizobiophages. In this study, 16S rRNA gene copies of R. radiobacter accounted for up to 5.6% of total bacterial 16S rRNA genes (average: 0.75%) as detected by quantitative PCR. A distinctive distribution was identified for R. radiobacter as indicated by a site-specific arrangement of genetically similar populations. Whole genome information of rhizobiophage RR1-A was used to generate a primer system for quantitative PCR specifically targeting the prophage antirepressor gene, indicative for temperate phages. The quantification of this gene within various sediment horizons showed a contribution of temperate phages of up to 14.3% to the total viral abundance. Thus, the high amount of temperate phages within the sediments and among all investigated isolates indicates that lysogeny is the main viral proliferation mode in deep subsurface populations. PMID:22855213

  12. Evaluation of Operationally Derived Aerosol Optical Depth from MSG-SEVIRI over Central Europe

    NASA Astrophysics Data System (ADS)

    Popp, C.; Riffler, M.; Emili, E.; Petitta, M.; Wunderle, S.

    2009-04-01

    Aerosol parameters derived from geostationary remote sensing instruments can complement those obtained from polar orbiting sensors (e.g. MODIS, MERIS, or AVHRR). The high scanning frequency of the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) on-board the Meteosat Second Generation (MSG) satellites of 15 minutes significantly broadens the potential diurnal coverage over Europe and Africa. Therefore, these data allow to better account for the occasionally high spatial and temporal variabilities of atmospheric aerosols, for instance in cases such as desert dust outbreaks, forest fires, or the evolution of high particulate matter concentrations during stable weather conditions. The aim of this study is to evaluate operationally derived aerosol optical depth maps based on imagery acquired by MSG-SEVIRI between December 2007 and November 2008. A one-channel multi-temporal approach is used in order to daily estimate aerosol optical depth for each slot between 6:12 and 18:12 UTC. The resulting SEVIRI AOD values are related to Sun photometer measurements from the Aerosol Robotic Network (AERONET). 22 AERONET sites within the study area of central Europe provide cloud-screened level1.5 data for the investigation period. Overall, nearly ten thousand instantaneous SEVIRI and Sun photometer AOD values are compared and a correlation of 0.75 as well as a root-mean-square-error of 0.07 is found. Further, about 75% of all SEVIRI AOD values fall within the MODIS expected error over land of +/-(0.05+0.15*AOD). Finally, the computed statistical parameters for each individual season do not vary strongly. Taken together, the performance of the operational SEVIRI AOD estimation is comparable to the ones based on data from sensors on-board polar orbiting satellites. Therefore, these aerosol information of high temporal frequency can be of great interest e.g. for tracking pollutant transport, for comparisons with aerosol modelling results, or for synergistic use with additional

  13. DO INTERMEDIATE RADIATION DOSES CONTRIBUTE TO LATE RECTAL TOXICITY? AN ANALYSIS OF DATA FROM RTOG 94-06

    PubMed Central

    Tucker, Susan L.; Dong, Lei; Michalski, Jeff M.; Bosch, Walter R.; Winter, Kathryn; Cox, James D.; Purdy, James A.; Mohan, Radhe

    2014-01-01

    Purpose To investigate whether the volumes of rectum exposed to intermediate doses, from 30-50 Gy, contribute to the risk of Grade ≥2 late rectal toxicity among patients with prostate cancer receiving radiotherapy. Methods and Materials Data from 1009 patients treated on Radiation Therapy Oncology Group (RTOG) protocol 94-06 were analyzed using three approaches. First, the contribution of intermediate doses to a previously published fit of the Lyman-Kutcher-Burman (LKB) normal-tissue complication probability (NTCP) model was determined. Next, the extent to which intermediate doses provide additional risk information, after taking the LKB model into account, was investigated. Third, the proportion of rectum receiving doses higher than a threshold, VDose, was computed for doses ranging from 5-85 Gy, and a multivariate Cox proportional hazards (PH) model was used to determine which of these parameters were significantly associated with time to Grade ≥2 late rectal toxicity. Results Doses <60 Gy have no detectable impact on the fit of the LKB model, as expected based on the small estimate of the volume parameter (n=0.077). Furthermore, there is no detectable difference in late rectal toxicity among cohorts with similar risk estimates from the LKB model but with different volumes of rectum exposed to intermediate doses. The multivariate Cox PH model selected V75 as the only value of VDose significantly associated with late rectal toxicity. Conclusions There is no evidence from these data that intermediate doses influence the risk of Grade ≥2 late rectal toxicity. Instead, the critical doses for this endpoint appear to be ≥75 Gy. It is hypothesized that cases of Grade ≥2 late rectal toxicity occurring among patients with V75 less than about 12% may be due to a “background” level of risk, likely due mainly to biological factors. PMID:22342302

  14. Uptake of Np(IV) by C-S-H phases and cement paste: an EXAFS study.

    PubMed

    Gaona, Xavier; Dähn, Rainer; Tits, Jan; Scheinost, Andreas C; Wieland, Erich

    2011-10-15

    Nuclear waste disposal concepts developed worldwide foresee the use of cementitious materials for the immobilization of long-lived intermediate level waste (ILW). This waste form may contain significant amounts of neptunium-237, which is expected to be present as Np(IV) under the reducing conditions encountered after the closure of the repository. Predicting the release of Np(IV) from the cementitious near field of an ILW repository requires a sufficiently detailed understanding of its interaction with the main sorbing components of hardened cement paste (HCP). In this study, the uptake of Np(IV) by calcium silicate hydrates (C-S-H) and HCP has been investigated using extended X-ray absorption fine structure (EXAFS) spectroscopy. The EXAFS studies on Np(IV)-doped C-S-H and HCP samples reveal that Np(IV) is predominantly incorporated in the structure of C-S-H phases having different Ca:Si ratios. The two main species identified correspond to Np(IV) in C-S-H with a Ca:Si mol ratio of 1.65 as in fresh cement and with a Ca:Si mol ratio of 0.75 as in highly degraded cement. The local structure of Np(IV) changes with the Ca:Si mol ratio and does not depend on pH. Furthermore, Np(IV) shows the same coordination environment in C-S-H and HCP samples. This study shows that C-S-H phases are responsible for the Np(IV) uptake by cementitious materials and further that incorporation in the interlayer of the C-S-H structure is the dominant uptake mechanism. PMID:21879756

  15. Spatial variability of metals in surface water and sediment in the langat river and geochemical factors that influence their water-sediment interactions.

    PubMed

    Lim, Wan Ying; Aris, Ahmad Zaharin; Zakaria, Mohamad Pauzi

    2012-01-01

    This paper determines the controlling factors that influence the metals' behavior water-sediment interaction facies and distribution of elemental content ((75)As, (111)Cd, (59)Co, (52)Cr, (60)Ni, and (208)Pb) in water and sediment samples in order to assess the metal pollution status in the Langat River. A total of 90 water and sediment samples were collected simultaneously in triplicate at 30 sampling stations. Selected metals were analyzed using ICP-MS, and the metals' concentration varied among stations. Metal concentrations of water ranged between 0.08-24.71 μg/L for As, <0.01-0.53 μg/L for Cd, 0.06-6.22 μg/L for Co, 0.32-4.67 μg/L for Cr, 0.80-24.72 μg/L for Ni, and <0.005-6.99 μg/L for Pb. Meanwhile, for sediment, it ranged between 4.47-30.04 mg/kg for As, 0.02-0.18 mg/kg for Cd, 0.87-4.66 mg/kg for Co, 4.31-29.04 mg/kg for Cr, 2.33-8.25 mg/kg for Ni and 5.57-55.71 mg/kg for Pb. The average concentration of studied metals in the water was lower than the Malaysian National Standard for Drinking Water Quality proposed by the Ministry of Health. The average concentration for As in sediment was exceeding ISQG standards as proposed by the Canadian Sediment Quality Guidelines. Statistical analyses revealed that certain metals (As, Co, Ni, and Pb) were generally influenced by pH and conductivity. These results are important when making crucial decisions in determining potential hazardous levels of these metals toward humans. PMID:22919346

  16. Genotypic Diversity and Drug Susceptibility Patterns among M. tuberculosis Complex Isolates from South-Western Ghana

    PubMed Central

    Yeboah-Manu, Dorothy; Asante-Poku, Adwoa; Bodmer, Thomas; Stucki, David; Koram, Kwadwo; Bonsu, Frank; Pluschke, Gerd; Gagneux, Sebastien

    2011-01-01

    Objective The aim of this study was to use spoligotyping and large sequence polymorphism (LSP) to study the population structure of M. tuberculosis complex (MTBC) isolates. Methods MTBC isolates were identified using standard biochemical procedures, IS6110 PCR, and large sequence polymorphisms. Isolates were further typed using spoligotyping, and the phenotypic drug susceptibility patterns were determined by the proportion method. Result One hundred and sixty-two isolates were characterised by LSP typing. Of these, 130 (80.25%) were identified as Mycobacterium tuberculosis sensu stricto (MTBss), with the Cameroon sub-lineage being dominant (N = 59/130, 45.38%). Thirty-two (19.75%) isolates were classified as Mycobacterium africanum type 1, and of these 26 (81.25%) were identified as West-Africa I, and 6 (18.75%) as West-Africa II. Spoligotyping sub-lineages identified among the MTBss included Haarlem (N = 15, 11.53%), Ghana (N = 22, 16.92%), Beijing (4, 3.08%), EAI (4, 3.08%), Uganda I (4, 3.08%), LAM (2, 1.54%), X (N = 1, 0.77%) and S (2, 1.54%). Nine isolates had SIT numbers with no identified sub-lineages while 17 had no SIT numbers. MTBss isolates were more likely to be resistant to streptomycin (p<0.008) and to any drug resistance (p<0.03) when compared to M. africanum. Conclusion This study demonstrated that overall 36.4% of TB in South-Western Ghana is caused by the Cameroon sub-lineage of MTBC and 20% by M. africanum type 1, including both the West-Africa 1 and West-Africa 2 lineages. The diversity of MTBC in Ghana should be considered when evaluating new TB vaccines. PMID:21779354

  17. Association Between the Cytogenetic Profile of Tumor Cells and Response to Preoperative Radiochemotherapy in Locally Advanced Rectal Cancer

    PubMed Central

    González-González, María; Garcia, Jacinto; Alcazar, José A.; Gutiérrez, María L.; Gónzalez, Luis M.; Bengoechea, Oscar; Abad, María M.; Santos-Briz, Angel; Blanco, Oscar; Martín, Manuela; Rodríguez, Ana; Fuentes, Manuel; Muñoz-Bellvis, Luis; Orfao, Alberto; Sayagues, Jose M.

    2014-01-01

    Abstract Neoadjuvant radiochemotherapy to locally advanced rectal carcinoma patients has proven efficient in a high percentage of cases. Despite this, some patients show nonresponse or even disease progression. Recent studies suggest that different genetic alterations may be associated with sensitivity versus resistance of rectal cancer tumor cells to neoadjuvant therapy. We investigated the relationship between intratumoral pathways of clonal evolution as assessed by interphase fluorescence in situ hybridization (51 different probes) and response to neoadjuvant radiochemotherapy, evaluated by Dworak criteria in 45 rectal cancer tumors before (n = 45) and after (n = 31) treatment. Losses of chromosomes 1p (44%), 8p (53%), 17p (47%), and 18q (38%) and gains of 1q (49%) and 13q (75%) as well as amplification of 8q (38%) and 20q (47%) chromosomal regions were those specific alterations found at higher frequencies. Significant association (P < 0.05) was found between alteration of 1p, 1q, 11p, 12p, and 17p chromosomal regions and degree of response to neoadjuvant therapy. A clear association was observed between cytogenetic profile of the ancestral tumor cell clone and response to radiochemotherapy; cases presenting with del(17p) showed a poor response to neoadjuvant treatment (P = 0.03), whereas presence of del(1p) was more frequently observed in responder patients (P = 0.0002). Moreover, a significantly higher number of copies of chromosomes 8q (P = 0.004), 13q (P = 0.003), and 20q (P = 0.002) were found after therapy versus paired pretreatment rectal cancer samples. Our results point out the existence of an association between tumor cytogenetics and response to neoadjuvant therapy in locally advanced rectal cancer. Further studies in larger series of patients are necessary to confirm our results. PMID:25474426

  18. Do Intermediate Radiation Doses Contribute to Late Rectal Toxicity? An Analysis of Data From Radiation Therapy Oncology Group Protocol 94-06

    SciTech Connect

    Tucker, Susan L.; Dong, Lei; Michalski, Jeff M.; Bosch, Walter R.; Winter, Kathryn; Cox, James D.; Purdy, James A.; Mohan, Radhe

    2012-10-01

    Purpose: To investigate whether the volumes of rectum exposed to intermediate doses, from 30 to 50 Gy, contribute to the risk of Grade {>=}2 late rectal toxicity among patients with prostate cancer receiving radiotherapy. Methods and Materials: Data from 1009 patients treated on Radiation Therapy Oncology Group protocol 94-06 were analyzed using three approaches. First, the contribution of intermediate doses to a previously published fit of the Lyman-Kutcher-Burman (LKB) normal tissue complication probability (NTCP) model was determined. Next, the extent to which intermediate doses provide additional risk information, after taking the LKB model into account, was investigated. Third, the proportion of rectum receiving doses higher than a threshold, VDose, was computed for doses ranging from 5 to 85 Gy, and a multivariate Cox proportional hazards model was used to determine which of these parameters were significantly associated with time to Grade {>=}2 late rectal toxicity. Results: Doses <60 Gy had no detectable impact on the fit of the LKB model, as expected on the basis of the small estimate of the volume parameter (n = 0.077). Furthermore, there was no detectable difference in late rectal toxicity among cohorts with similar risk estimates from the LKB model but with different volumes of rectum exposed to intermediate doses. The multivariate Cox proportional hazards model selected V75 as the only value of VDose significantly associated with late rectal toxicity. Conclusions: There is no evidence from these data that intermediate doses influence the risk of Grade {>=}2 late rectal toxicity. Instead, the critical doses for this endpoint seem to be {>=}75 Gy. It is hypothesized that cases of Grade {>=}2 late rectal toxicity occurring among patients with V75 less than approximately 12% may be due to a 'background' level of risk, likely due mainly to biological factors.

  19. Effect of subdomain interactions on methyl group dynamics in the hydrophobic core of villin headpiece protein

    PubMed Central

    Vugmeyster, Liliya; Do, Tien; Ostrovsky, Dmitry; Fu, Riqianq

    2014-01-01

    Thermostable villin headpiece protein (HP67) consists of the N-terminal subdomain (residues 10–41) and the autonomously folding C-terminal subdomain (residues 42–76) which pack against each other to form a structure with a unified hydrophobic core. The X-ray structures of the isolated C-terminal subdomain (HP36) and its counterpart in HP67 are very similar for the hydrophobic core residues. However, fine rearrangements of the free energy landscape are expected to occur because of the interactions between the two subdomains. We detect and characterize these changes by comparing the µs-ms time scale dynamics of the methyl-bearing side chains in isolated HP36 and in HP67. Specifically, we probe three hydrophobic side chains at the interface of the two subdomains (L42, V50, and L75) as well as at two residues far from the interface (L61 and L69). Solid-state deuteron NMR techniques are combined with computational modeling for the detailed characterization of motional modes in terms of their kinetic and thermodynamic parameters. The effect of interdomain interactions on side chain dynamics is seen for all residues but L75. Thus, changes in dynamics because of subdomain interactions are not confined to the site of perturbation. One of the main results is a two-to threefold increase in the value of the activation energies for the rotameric mode of motions in HP67 compared with HP36. Detailed analysis of configurational entropies and heat capacities complement the kinetic view of the degree of the disorder in the folded state. PMID:24243806

  20. Prediction of water content at different potentials from soil property data in Jazan region

    NASA Astrophysics Data System (ADS)

    Alturki, Ali; Ibrahim, Hesham

    2016-04-01

    In dry regions effective irrigation management is crucial to maintain crop production and sustain limited water resources. Effective irrigation requires good knowledge of soil water content in the root zone. However, measurement of soil water in the root zone over time is extremely expensive and time consuming. On the other hand, weather and basic soil property data are more available, either from existing databases or by direct measurement in the field. Simulation models can be used to efficiently and accurately estimate soil water content and subsequent irrigation requirements based on the available weather and soil data. In this study we investigated three hierarchical approaches to predict water content at variable potentials (0, 10, 33, 60, 100, 300, 500, 800, 1000, and 1500 kPa) using the Rosetta model: soil texture class (STC); percent of sand, silt, and clay (SSC); bulk density, percent of sand, silt, and clay, and water content measurements at 33 and 1500 kPa (SSC+WC). Estimation of soil water content at 43 locations in Jazan region using the three hierarchical approaches was compared with gravimetric water content. Results showed that the three approaches failed to describe water content accurately at saturation conditions (<10kPa). At water potentials lower than 10 kPa, good agreement was obtained, in general, between measured and simulated soil water content indicating that soil property data can be used to provide adequate estimates of the average soil water content in the root zone. The third approach gave the best results as indicated by an average NSCE value of 0.75 as compared to 0.16 and 0.18 for the first and second approaches, respectively. The ability to predict the amount of available water in the soil profile will facilitate the accurate estimate of irrigation requirements and achieve effective irrigation scheduling especially in locations where only limited weather and soil date are available.

  1. Efficacy and safety of dulaglutide in patients with type 2 diabetes: a meta-analysis and systematic review

    PubMed Central

    Zhang, Lin; Zhang, Mei; Zhang, Yuwei; Tong, Nanwei

    2016-01-01

    A meta-analysis was conducted to assess the clinical efficacy and safety of dulaglutide in patients with type 2 diabetes mellitus (T2DM). Medline, Embase, Cochrane Library and www. clinicaltrials. gov (up to February 15th, 2015) were searched. Randomized controlled trials comparing dulaglutide to other drugs for T2DM were collected. Twelve RCTs were included, and the overall bias was low. As the monotherapy, compared with control (placebo, metformin and liraglutide), dulaglutide resulted in a significant reduction in HbA1c (WMD, −0.68%; 95% CI, −0.95 to −0.40), FPG (WMD, −0.90 mmol/L; 95% CI, −1.28 to −0.52), a similar risk of hypoglycemia (7.8% vs. 10.6%), less body weight loss (WMD, 0.51 kg; 95% CI, 0.27 to 0.75). As an add-on intervention with oral antihyperglycemic medication (OAM) and insulin, compared with control (placebo, sitagliptin, exenatide, liraglutide and glargine), dulaglutide lowered HbA1c (WMD, −0.51%; 95% CI, −0.68 to −0.35) and body weight significantly (WMD, −1.30 kg, 95% CI, −1.85 to −1.02) notably, and elicited a similar reduction in FPG (WMD, −0.19 mmol/L; 95% CI, −1.20 to 0.82), an similar incidence of hypoglycemia (24.5% vs. 24.5%). This meta-analysis revealed the use of dulaglutide as a monotherapy or an add-on to OAM and lispro appeared to be effective and safe for adults with T2DM. PMID:26742577

  2. Biocatalytic properties and substrate-binding ability of a modular GH10 β-1,4-xylanase from an insect-symbiotic bacterium, Streptomyces mexicanus HY-14.

    PubMed

    Kim, Do Young; Shin, Dong-Ha; Jung, Sora; Lee, Jong Suk; Cho, Han-Young; Bae, Kyung Sook; Sung, Chang-Keun; Rhee, Young Ha; Son, Kwang-Hee; Park, Ho-Yong

    2014-10-01

    The gene (1350-bp) encoding a modular β-1,4-xylanase (XylU), which consists of an N-terminal catalytic GH10 domain and a C-terminal carbohydrate-binding module 2 (CBM 2), from Streptomyces mexicanus HY-14 was cloned and functionally characterized. The purified His-tagged recombinant enzyme (rXylU, 44.0 kDa) was capable of efficiently hydrolyze diverse xylosidic compounds, p-nitrophenyl-cellobioside, and p-nitrophenyl-xylopyranoside when incubated at pH 5.5 and 65°C. Especially, the specific activities (649.8 U/mg and 587.0 U/mg, respectively) of rXylU toward oat spelts xylan and beechwood xylan were relatively higher than those (<500.0 U/mg) of many other GH10 homologs toward the same substrates. The results of enzymatic degradation of birchwood xylan and xylooligosaccharides (xylotriose to xylohexaose) revealed that rXylU preferentially hydrolyzed the substrates to xylobiose (>75%) as the primary degradation product. Moreover, a small amount (4%<) of xylose was detected as the degradation product of the evaluated xylosidic substrates, indicating that rXylU was a peculiar GH10 β-1,4-xylanase with substrate specificity, which was different from its retaining homologs. A significant reduction of the binding ability of rXylU caused by deletion of the C-terminal CBM 2 to various insoluble substrates strongly suggested that the additional domain might considerably contribute to the enzyme-substrate interaction. PMID:25269606

  3. Association between the cytogenetic profile of tumor cells and response to preoperative radiochemotherapy in locally advanced rectal cancer.

    PubMed

    González-González, María; Garcia, Jacinto; Alcazar, José A; Gutiérrez, María L; Gónzalez, Luis M; Bengoechea, Oscar; Abad, María M; Santos-Briz, Angel; Blanco, Oscar; Martín, Manuela; Rodríguez, Ana; Fuentes, Manuel; Muñoz-Bellvis, Luis; Orfao, Alberto; Sayagues, Jose M

    2014-11-01

    Neoadjuvant radiochemotherapy to locally advanced rectal carcinoma patients has proven efficient in a high percentage of cases. Despite this, some patients show nonresponse or even disease progression. Recent studies suggest that different genetic alterations may be associated with sensitivity versus resistance of rectal cancer tumor cells to neoadjuvant therapy. We investigated the relationship between intratumoral pathways of clonal evolution as assessed by interphase fluorescence in situ hybridization (51 different probes) and response to neoadjuvant radiochemotherapy, evaluated by Dworak criteria in 45 rectal cancer tumors before (n = 45) and after (n = 31) treatment. Losses of chromosomes 1p (44%), 8p (53%), 17p (47%), and 18q (38%) and gains of 1q (49%) and 13q (75%) as well as amplification of 8q (38%) and 20q (47%) chromosomal regions were those specific alterations found at higher frequencies. Significant association (P < 0.05) was found between alteration of 1p, 1q, 11p, 12p, and 17p chromosomal regions and degree of response to neoadjuvant therapy. A clear association was observed between cytogenetic profile of the ancestral tumor cell clone and response to radiochemotherapy; cases presenting with del(17p) showed a poor response to neoadjuvant treatment (P = 0.03), whereas presence of del(1p) was more frequently observed in responder patients (P = 0.0002). Moreover, a significantly higher number of copies of chromosomes 8q (P = 0.004), 13q (P = 0.003), and 20q (P = 0.002) were found after therapy versus paired pretreatment rectal cancer samples. Our results point out the existence of an association between tumor cytogenetics and response to neoadjuvant therapy in locally advanced rectal cancer. Further studies in larger series of patients are necessary to confirm our results. PMID:25474426

  4. Salicylic acid elicitation during cultivation of the peppermint plant improves anti-diabetic effects of its infusions.

    PubMed

    Figueroa-Pérez, Marely G; Gallegos-Corona, Marco A; Ramos-Gomez, Minerva; Reynoso-Camacho, Rosalía

    2015-06-01

    Peppermint (Mentha piperita) infusions represent an important source of bioactive compounds with health benefits, which can be enhanced by applying salicylic acid (SA) during plant cultivation. The aim of this study was to evaluate the effect of SA (0, 0.5 and 2 mM) during peppermint cultivation on the chemical profile of saponins and alkaloids, as well as the anti-diabetic properties of the resulting infusions. The results showed that a 2 mM SA treatment significantly improved the chemical profiles of the infusions. Furthermore, the administration of 2 mM SA-treated peppermint infusions for 4 weeks to a high-fat diet/streptozotocin-induced diabetic rats decreased serum glucose levels (up to 25%) and increased serum insulin levels (up to 75%) as compared with the diabetic control. This can be related to the observed protection on pancreatic β-cells. Furthermore, 0.5 and 2 mM SA-treated peppermint infusions decreased LDL (24 and 47%, respectively) and increased HDL levels (18 and 37%, respectively). In addition, all groups treated with peppermint infusions had lower serum and liver triglyceride contents, where 2 mM SA peppermint infusion showed the highest effect (44% and 56%, respectively). This is probably caused by its higher capacity to inhibit pancreatic lipase activity and lipid absorption. Moreover, SA-treated peppermint infusions improved the steatosis score in diabetic rat liver and decreased serum transaminase levels, probably as a result of the increase in steroidal saponins and alkaloids, such as trigonellin. Therefore, the application of 2 mM SA during cultivation of peppermint could be used to improve the anti-diabetic properties of peppermint infusions. PMID:25940690

  5. Evolution and characterization of a new reversibly photoswitching chromogenic protein, Dathail.

    PubMed

    Langan, Patricia S; Close, Devin W; Coates, Leighton; Rocha, Reginaldo C; Ghosh, Koushik; Kiss, Csaba; Waldo, Geoff; Freyer, James; Kovalevsky, Andrey; Bradbury, Andrew R M

    2016-05-01

    We report the engineering of a new reversibly switching chromogenic protein, Dathail. Dathail was evolved from the extremely thermostable fluorescent proteins thermal green protein (TGP) and eCGP123 using directed evolution and ratiometric sorting. Dathail has two spectrally distinct chromogenic states with low quantum yields, corresponding to absorbance in a ground state with a maximum at 389nm, and a photo-induced metastable state with a maximum at 497nm. In contrast to all previously described photoswitchable proteins, both spectral states of Dathail are non-fluorescent. The photo-induced chromogenic state of Dathail has a lifetime of ~50min at 293K and pH7.5 as measured by UV-Vis spectrophotometry, returning to the ground state through thermal relaxation. X-ray crystallography provided structural insights supporting a change in conformation and coordination in the chromophore pocket as being responsible for Dathail's photoswitching. Neutron crystallography, carried out for the first time on a protein from the green fluorescent protein family, showed a distribution of hydrogen atoms revealing protonation of the chromophore 4-hydroxybenzyl group in the ground state. The neutron structure also supports the hypothesis that the photo-induced proton transfer from the chromophore occurs through water-mediated proton relay into the bulk solvent. Beyond its spectroscopic curiosity, Dathail has several characteristics that are improvements for applications, including low background fluorescence, large spectral separation, rapid switching time, and the ability to switch many times. Therefore, Dathail is likely to be extremely useful in the quickly developing fields of imaging and biosensors, including photochromic Förster resonance energy transfer, high-resolution microscopy, and live tracking within the cell. PMID:27000644

  6. Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates.

    PubMed

    Vorsino, Adam E; Fortini, Lucas B; Amidon, Fred A; Miller, Stephen E; Jacobi, James D; Price, Jonathan P; Gon, Sam 'ohukani'ohi'a; Koob, Gregory A

    2014-01-01

    Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with <0.7 niche overlap (Warrens I) and relatively discriminative distributions (Area Under the Curve >0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions. PMID:24805254

  7. Modeling Hawaiian ecosystem degradation due to invasive plants under current and future climates.

    PubMed

    Vorsino, Adam E; Fortini, Lucas B; Amidon, Fred A; Miller, Stephen E; Jacobi, James D; Price, Jonathan P; 'Ohukani'ohi'a Gon, Sam; Koob, Gregory A

    2014-01-01

    Occupation of native ecosystems by invasive plant species alters their structure and/or function. In Hawaii, a subset of introduced plants is regarded as extremely harmful due to competitive ability, ecosystem modification, and biogeochemical habitat degradation. By controlling this subset of highly invasive ecosystem modifiers, conservation managers could significantly reduce native ecosystem degradation. To assess the invasibility of vulnerable native ecosystems, we selected a proxy subset of these invasive plants and developed robust ensemble species distribution models to define their respective potential distributions. The combinations of all species models using both binary and continuous habitat suitability projections resulted in estimates of species richness and diversity that were subsequently used to define an invasibility metric. The invasibility metric was defined from species distribution models with <0.7 niche overlap (Warrens I) and relatively discriminative distributions (Area Under the Curve >0.8; True Skill Statistic >0.75) as evaluated per species. Invasibility was further projected onto a 2100 Hawaii regional climate change scenario to assess the change in potential habitat degradation. The distribution defined by the invasibility metric delineates areas of known and potential invasibility under current climate conditions and, when projected into the future, estimates potential reductions in native ecosystem extent due to climate-driven invasive incursion. We have provided the code used to develop these metrics to facilitate their wider use (Code S1). This work will help determine the vulnerability of native-dominated ecosystems to the combined threats of climate change and invasive species, and thus help prioritize ecosystem and species management actions. PMID:24991934

  8. Improvement of the piezoelectric properties in (K,Na)NbO3-based lead-free piezoelectric ceramic with two-phase co-existing state

    NASA Astrophysics Data System (ADS)

    Yamada, H.; Matsuoka, T.; Kozuka, H.; Yamazaki, M.; Ohbayashi, K.; Ida, T.

    2015-06-01

    Two phases of (K,Na)NbO3 (KNN) co-exist in a KNN-based composite lead-free piezoelectric ceramic 0.910(K1-xNax)0.86Ca0.04Li0.02Nb0.85O3-δ-0.042K0.85Ti0.85Nb1.15O5-0.036BaZrO3-0.0016Co3O4- 0.0025Fe2O3-0.0069ZnO system, over a wide range of Na fractions, where 0.56 ≤ x ≤ 0.75. The crystal systems of the two KNN phases are identified to tetragonal and orthorhombic by analyzing the synchrotron powder X-ray diffraction (XRD) data, high-resolution transmission electron microscopy (HR-TEM), and selected-area electron diffraction (SAD). In the range 0.33 ≤ x ≤ 0.50, the main component of the composite system is found to be single-phase KNN with a tetragonal structure. Granular nanodomains of the orthorhombic phase dispersed in the tetragonal matrix have been identified by HR-TEM and SAD for 0.56 ≤ x ≤ 0.75. Only a trace amount of the orthorhombic phase has been found in the SAD patterns at the composition x = 0.56. However, the number of orthorhombic nanodomains gradually increases with increasing Na content up to x < 0.75, as observed from the HR-TEM images. An abrupt increase and agglomeration of the nanodomains are observed at x = 0.75, where weak diffraction peaks of the orthorhombic phase have also become detectable from the XRD data. The maximum value of the electromechanical coupling coefficient, kp = 0.56, has been observed at the composition x = 0.56.

  9. Transmission electron microscopy investigation of segregation and critical floating-layer content of indium for island formation in InxGa1-xAs

    NASA Astrophysics Data System (ADS)

    Litvinov, D.; Gerthsen, D.; Rosenauer, A.; Schowalter, M.; Passow, T.; Feinäugle, P.; Hetterich, M.

    2006-10-01

    We have investigated InxGa1-xAs layers grown by molecular-beam epitaxy on GaAs(001) by transmission electron microscopy (TEM) and photoluminescence spectroscopy. InGaAs layers with In concentrations of 16, 25, and 28% and respective thicknesses of 20, 22, and 23 monolayers were deposited at 535°C . The parameters were chosen to grow layers slightly above and below the transition between the two- and three-dimensional growth mode. In-concentration profiles were obtained from high-resolution TEM images by composition evaluation by lattice fringe analysis. The measured profiles can be well described applying the segregation model of Muraki [Appl. Phys. Lett. 61, 557 (1992)]. Calculated photoluminescence peak positions on the basis of the measured concentration profiles are in good agreement with the experimental ones. Evaluating experimental In-concentration profiles it is found that the transition from the two-dimensional to the three-dimensional growth mode occurs if the indium content in the In floating layer exceeds 1.1±0.2 monolayers. The measured exponential decrease of the In concentration within the cap layer on top of the islands reveals that the In floating layer is not consumed during island formation. In addition, In0.25Ga0.75As quantum wells were grown at different temperatures between 500°C and 550°C . The evaluation of concentration profiles shows that the segregation efficiency increases from R=0.65 to R=0.83 . The strong increase of R with the growth temperature is explained by the large growth rate of 1.5ML/s . Comparison with the temperature dependence of published segregation efficiencies obtained at lower growth rates reveals increasing temperature dependence and decreasing segregation efficiency with increasing growth rate.

  10. Fractal Geometry and the Pharmacometrics of Micafungin in Overweight, Obese, and Extremely Obese People▿

    PubMed Central

    Hall, Ronald G.; Swancutt, Mark A.; Gumbo, Tawanda

    2011-01-01

    The majority of Americans are overweight, and the incidence of obesity continues to increase. This trend predisposes people to a number of deleterious consequences, including the metabolic syndrome and other conditions that lead to a greater number of hospital admissions. Invasive candidiasis is an important nosocomial infection that results from these admissions. Echinocandins such as micafungin are indicated for treatment. We have previously demonstrated that overweight patients exhibit higher micafungin systemic clearance (SCL) than leaner patients. We hypothesized that obese and extremely obese people would show even higher SCL than merely overweight patients. To test this, we performed a prospective study of 36 adult volunteers randomized to receive a single dose of either 100 mg or 300 mg of micafungin whose body mass index fell within one of the following categories: <25, 25 to 40, and >40 kg/m2. The male-to-female ratio was 1:1. The minimum weight was 43 kg, the median 97 kg, and the maximum weight 155 kg. A two-compartment model was examined using the maximum likelihood solution via the expectation-maximization algorithm. Men had a higher median SCL of 1.53 liters/h versus 1.29 liters/h (P = 0.01) in the Mann-Whitney U-test. The typical SCL was 1.04 liters/h but increased by a factor of (weight/66)0.75 as weight increased above 66 kg. Thus, the relationship between micafungin SCL and weight in adults is best described by fractal-geometry-based laws. Furthermore, micafungin SCL continues to increase as weight increases, with no obvious plateau. This leads to a requirement for strategies to determine individualized dosing levels for obese and extremely obese patients. PMID:21876061

  11. Severity of urban cycling injuries and the relationship with personal, trip, route and crash characteristics: analyses using four severity metrics

    PubMed Central

    Cripton, Peter A; Shen, Hui; Brubacher, Jeff R; Chipman, Mary; Friedman, Steven M; Harris, M Anne; Winters, Meghan; Reynolds, Conor C O; Cusimano, Michael D; Babul, Shelina; Teschke, Kay

    2015-01-01

    Objective To examine the relationship between cycling injury severity and personal, trip, route and crash characteristics. Methods Data from a previous study of injury risk, conducted in Toronto and Vancouver, Canada, were used to classify injury severity using four metrics: (1) did not continue trip by bike; (2) transported to hospital by ambulance; (3) admitted to hospital; and (4) Canadian Triage and Acuity Scale (CTAS). Multiple logistic regression was used to examine associations with personal, trip, route and crash characteristics. Results Of 683 adults injured while cycling, 528 did not continue their trip by bike, 251 were transported by ambulance and 60 were admitted to hospital for further treatment. Treatment urgencies included 75 as CTAS=1 or 2 (most medically urgent), 284 as CTAS=3, and 320 as CTAS=4 or 5 (least medically urgent). Older age and collision with a motor vehicle were consistently associated with increased severity in all four metrics and statistically significant in three each (both variables with ambulance transport and CTAS; age with hospital admission; and motor vehicle collision with did not continue by bike). Other factors were consistently associated with more severe injuries, but statistically significant in one metric each: downhill grades; higher motor vehicle speeds; sidewalks (these significant for ambulance transport); multiuse paths and local streets (both significant for hospital admission). Conclusions In two of Canada's largest cities, about one-third of the bicycle crashes were collisions with motor vehicles and the resulting injuries were more severe than in other crash circumstances, underscoring the importance of separating cyclists from motor vehicle traffic. Our results also suggest that bicycling injury severity and injury risk would be reduced on facilities that minimise slopes, have lower vehicle speeds, and that are designed for bicycling rather than shared with pedestrians. PMID:25564148

  12. Wobble Pairs of the HDV Ribozyme Play Specific Roles in Stabilization of Active Site Dynamics

    PubMed Central

    Sripathi, Kamali N.; Banáš, Pavel; Reblova, Kamila; Šponer, Jiři; Otyepka, Michal

    2015-01-01

    The hepatitis delta virus (HDV) is the only known human pathogen whose genome contains a catalytic RNA motif (ribozyme). The overall architecture of the HDV ribozyme is that of a double-nested pseudoknot, with two GU pairs flanking the active site. Although extensive studies have shown that mutation of either wobble results in decreased catalytic activity, little work has focused on linking these mutations to specific structural effects on catalytic fitness. Here we use molecular dynamics simulations based on an activated structure to probe the active site dynamics as a result of wobble pair mutations. In both wild-type and mutant ribozymes, the in-line fitness of the active site (as a measure of catalytic proficiency) strongly depends on the presence of a C75(N3H3+)N1(O5′) hydrogen bond, which positions C75 as the general acid for the reaction. Our mutational analyses show that each GU wobble supports catalytically fit conformations in distinct ways; the reverse G25U20 wobble promotes high in-line fitness, high occupancy of the C75(N3H3+)G1(O5′) general-acid hydrogen bond and stabilization of the G1U37 wobble, while the G1U37 wobble acts more locally by stabilizing high in-line fitness and the C75(N3H3+)G1(O5′) hydrogen bond. We also find that stable type I A-minor and P1.1 hydrogen bonding above and below the active site, respectively, prevent local structural disorder from spreading and disrupting global conformation. Taken together, our results define specific, often redundant architectural roles for several structural motifs of the HDV ribozyme active site, expanding the known roles of these motifs within all HDV-like ribozymes and other structured RNAs. PMID:25631765

  13. Physical and biophysical assessment of highly fluorescent, magnetic quantum dots of a wurtzite-phase manganese selenide system

    NASA Astrophysics Data System (ADS)

    Sarma, Runjun; Das, Queen; Hussain, Anowar; Ramteke, Anand; Choudhury, Amarjyoti; Mohanta, Dambarudhar

    2014-07-01

    Combining fluorescence and magnetic features in a non-iron based, select type of quantum dots (QDs) can have immense value in cellular imaging, tagging and other nano-bio interface applications, including targeted drug delivery. Herein, we report on the colloidal synthesis and physical and biophysical assessment of wurtzite-type manganese selenide (MnSe) QDs in cell culture media. Aiming to provide a suitable colloidal system of biological relevance, different concentrations of reactants and ligands (e.g., thioglycolic acid, TGA) have been considered. The average size of the QDs is ˜7 nm, which exhibited a quantum yield of ˜75% as compared to rhodamine 6 G dye®. As revealed from time-resolved photoluminescence (TR-PL) response, the near band edge emission followed a bi-exponential decay feature with characteristic times of ˜0.64 ns and 3.04 ns. At room temperature, the QDs were found to exhibit paramagnetic features with coercivity and remanence impelled by TGA concentrations. With BSA as a dispersing agent, the QDs showed an improved optical stability in Dulbecco’s Modified Eagle Media® (DMEM) and Minimum Essential Media® (MEM), as compared to the Roswell Park Memorial Institute® (RPMI-1640) media. Finally, the cell viability of lymphocytes was found to be strongly influenced by the concentration of MnSe QDs, and had a safe limit upto 0.5 μM. With BSA inclusion in cell media, the cellular uptake of MnSe QDs was observed to be more prominent, as revealed from fluorescence imaging. The fabrication of water soluble, nontoxic MnSe QDs would open up an alternative strategy in nanobiotechnology, while preserving their luminescent and magnetic properties intact.

  14. Physical and biophysical assessment of highly fluorescent, magnetic quantum dots of a wurtzite-phase manganese selenide system.

    PubMed

    Sarma, Runjun; Das, Queen; Hussain, Anowar; Ramteke, Anand; Choudhury, Amarjyoti; Mohanta, Dambarudhar

    2014-07-11

    Combining fluorescence and magnetic features in a non-iron based, select type of quantum dots (QDs) can have immense value in cellular imaging, tagging and other nano-bio interface applications, including targeted drug delivery. Herein, we report on the colloidal synthesis and physical and biophysical assessment of wurtzite-type manganese selenide (MnSe) QDs in cell culture media. Aiming to provide a suitable colloidal system of biological relevance, different concentrations of reactants and ligands (e.g., thioglycolic acid, TGA) have been considered. The average size of the QDs is ∼7 nm, which exhibited a quantum yield of ∼75% as compared to rhodamine 6 G dye(®). As revealed from time-resolved photoluminescence (TR-PL) response, the near band edge emission followed a bi-exponential decay feature with characteristic times of ∼0.64 ns and 3.04 ns. At room temperature, the QDs were found to exhibit paramagnetic features with coercivity and remanence impelled by TGA concentrations. With BSA as a dispersing agent, the QDs showed an improved optical stability in Dulbecco's Modified Eagle Media(®) (DMEM) and Minimum Essential Media(®) (MEM), as compared to the Roswell Park Memorial Institute(®) (RPMI-1640) media. Finally, the cell viability of lymphocytes was found to be strongly influenced by the concentration of MnSe QDs, and had a safe limit upto 0.5 μM. With BSA inclusion in cell media, the cellular uptake of MnSe QDs was observed to be more prominent, as revealed from fluorescence imaging. The fabrication of water soluble, nontoxic MnSe QDs would open up an alternative strategy in nanobiotechnology, while preserving their luminescent and magnetic properties intact. PMID:24960126

  15. Cross Sections Calculations of ( d, t) Nuclear Reactions up to 50 MeV

    NASA Astrophysics Data System (ADS)

    Tel, E.; Yiğit, M.; Tanır, G.

    2013-04-01

    In nuclear fusion reactions two light atomic nuclei fuse together to form a heavier nucleus. Fusion power is the power generated by nuclear fusion processes. In contrast with fission power, the fusion reaction processes does not produce radioactive nuclides. The fusion will not produce CO2 or SO2. So the fusion energy will not contribute to environmental problems such as particulate pollution and excessive CO2 in the atmosphere. Fusion powered electricity generation was initially believed to be readily achievable, as fission power had been. However, the extreme requirements for continuous reactions and plasma containment led to projections being extended by several decades. In 2010, more than 60 years after the first attempts, commercial power production is still believed to be unlikely before 2050. Although there have been significant research and development studies on the inertial and magnetic fusion reactor technology, there is still a long way to go to penetrate commercial fusion reactors to the energy market. In the fusion reactor, tritium self-sufficiency must be maintained for a commercial power plant. Therefore, for self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. Working out the systematics of ( d, t) nuclear reaction cross sections is of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at different energies. Since the experimental data of charged particle induced reactions are scarce, self-consistent calculation and analyses using nuclear theoretical models are very important. In this study, ( d, t) cross sections for target nuclei 19F, 50Cr, 54Fe, 58Ni, 75As, 89Y, 90Zr, 107Ag, 127I, 197Au and 238U have been investigated up to 50 MeV deuteron energy. The excitation functions for ( d, t) reactions have been calculated by pre-equilibrium reaction mechanism. Calculation results have been also compared with the available measurements in

  16. Tennis Play Intensity Distribution and Relation with Aerobic Fitness in Competitive Players.

    PubMed

    Baiget, Ernest; Fernández-Fernández, Jaime; Iglesias, Xavier; Rodríguez, Ferran A

    2015-01-01

    The aims of this study were (i) to describe the relative intensity of simulated tennis play based on the cumulative time spent in three metabolic intensity zones, and (ii) to determine the relationships between this play intensity distribution and the aerobic fitness of a group of competitive players. 20 male players of advanced to elite level (ITN) performed an incremental on-court specific endurance tennis test to exhaustion to determine maximal oxygen uptake (VO2max) and the first and second ventilatory thresholds (VT1, VT2). Ventilatory and gas exchange parameters were monitored using a telemetric portable gas analyser (K4 b2, Cosmed, Rome, Italy). Two weeks later the participants played a simulated tennis set against an opponent of similar level. Intensity zones (1: low, 2: moderate, and 3: high) were delimited by the individual VO2 values corresponding to VT1 and VT2, and expressed as percentage of maximum VO2 and heart rate. When expressed relative to VO2max, percentage of playing time in zone 1 (77 ± 25%) was significantly higher (p < 0.001) than in zone 2 (20 ± 21%) and zone 3 (3 ± 5%). Moderate to high positive correlations were found between VT1, VT2 and VO2max, and the percentage of playing time spent in zone 1 (r = 0.68-0.75), as well as low to high inverse correlations between the metabolic variables and the percentage of time spent in zone 2 and 3 (r = -0.49-0.75). Players with better aerobic fitness play at relatively lower intensities. We conclude that players spent more than 75% of the time in their low-intensity zone, with less than 25% of the time spent at moderate to high intensities. Aerobic fitness appears to determine the metabolic intensity that players can sustain throughout the game. PMID:26098638

  17. Development and Validation of HPLC and HPTLC Methods for Determination of Cefoperazone and Its Related Impurities.

    PubMed

    Abdelaleem, Eglal A; Naguib, Ibrahim A; Zaazaa, Hala E; Hussein, Essraa A

    2016-02-01

    Validated sensitive and highly selective methods were developed for the quantitative determination of cefoperazone sodium (CEF) in the presence of its reported impurities; 7-aminocephalosporanic acid (7-ACA) and 5-mercapto-1-methyl-tetrazole (5-MER). Method A is high-performance liquid chromatography (HPLC), where the mixture of CEF and the reported impurities; 7-ACA and 5-MER were separated on a C8 column (5 µm ps, 250 mm × 4.6 i.d.) using methanol:0.05 M KH2PO4 buffer (22.5:77.5 v/v, pH 7.5) as a mobile phase. The three components were detected at 254 nm with a concentration range of 10-90 µg mL(-1) and the mean percentage recovery 99.67% (SD 1.465). Method B is high-performance thin layer chromatography (HPTLC), where the mixture of CEF and the reported impurities were separated on silica gel HPTLC F254 plates using (acetone:methanol:ethyl acetate:2% sodium lauryl sulfate:glacial acetic acid) (3:2:3:0.8:0.2, by volume) as a developing system and scanning at 254 nm over a concentration range of 1-10 µg per band with the mean percentage recovery 99.95% (SD 1.335). The proposed methods were statistically compared with a reported HPLC method with no significant difference regarding accuracy and precision; indicating the ability of the proposed methods to be reliable and suitable for routine analysis of drug product. The proposed HPTLC method proved to be more sensitive, while the HPLC gave more reproducible results besides saving time. PMID:26306573

  18. A Re-Analysis of Historical Los Alamos Critical Assembly Reaction Rate Measurements

    NASA Astrophysics Data System (ADS)

    Kahler, A. C.; MacInnes, M.; Chadwick, M. B.

    2016-02-01

    Starting in the 1950s and continuing into the early 1970s, a number of foil irradiations and fission chamber measurements were made in a variety of Fast critical assemblies at Los Alamos National Laboratory. These include (i) Godiva, a bare HEU spherical assembly; (ii) Flattop-25, a spherical assembly consisting of an HEU core and a natural uranium reflector; (iii) Jezebel, a bare 239Pu assembly; and (iv) Flattop-Pu, a spherical assembly consisting of a 239Pu core and a natural uranium reflector. In most instances the irradiations occur at or near the center of the assembly, but in selected instances data were obtained for a radial traverse extending into the Flattop reflector region. Measurements were made for a number of threshold reactions, including 45Sc(n,2n)44mSc, 51V(n,α)48Sc, 75As(n,2n)74As, 89Y(n,2n)88Y, 90Zr(n,2n)89Zr, 103Rh(n,2n)102gRh, 107Ag(n,2n)106mAg, 169Tm(n,2n)168Tm, 175Lu(n,2n)174Lu, 191Ir(n,2n)190Ir, 197Au(n,2n)196Au, 203Tl(n,2n)202Tl, 204Pb(n,2n)203Pb and 238U(n,2n)237U. Fission ratio data for 238U(n,f)/235U(n,f) and 239Pu(n,f)/235U(n,f) were also obtained. We report C/E values from MCNP6 calculations using ENDF/B-VII.1 and IRDFF-v1.03 cross section data.

  19. Tracing Back Clinical Campylobacter jejuni in the Northwest of Italy and Assessing Their Potential Source

    PubMed Central

    Di Giannatale, Elisabetta; Garofolo, Giuliano; Alessiani, Alessandra; Di Donato, Guido; Candeloro, Luca; Vencia, Walter; Decastelli, Lucia; Marotta, Francesca

    2016-01-01

    Food-borne campylobacteriosis is caused mainly by the handling or consumption of undercooked chicken meat or by the ingestion of contaminated raw milk. Knowledge about the contributions of different food sources to gastrointestinal disease is fundamental to prioritize food safety interventions and to establish proper control strategies. Assessing the genetic diversity among Campylobacter species is essential to our understanding of their epidemiology and population structure. We molecularly characterized 56 Campylobacter jejuni isolates (31 from patients hospitalized with gastroenteritis, 17 from raw milk samples, and 8 from chicken samples) using multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) in order to trace the source of the disease. We also used a population genetic approach to investigate the source of the human cases from six different reservoirs of infection. MLST identified 25 different sequence types and 11 clonal complexes (CCs) (21, 658, 206, 353, 443, 48, 61, 257, 1332, 354, 574) and these included several alleles not cited previously in the PubMLST international database. The most prevalent CCs were 21, 206, and 354. PFGE showed 34 pulsotypes divided between 28 different clusters. At the fine scale, by means of PFGE and MLST, only two human cases were linked to raw milk, while one case was linked to chicken meat. The investigation revealed the presence of several genotypes among the human isolates, which probably suggests multiple foci for the infections. Finally, the source attribution model we used revealed that most cases were attributed to chicken (69.75%) as the main reservoir in Italy, followed to a lesser extent by the following sources: cattle (8.25%); environment (6.28%); wild bird (7.37%); small ruminant (5.35%), and pork (2.98%). This study confirms the importance of correlating epidemiological investigations with molecular epidemiological data to better understand the dynamics of infection. PMID:27379033

  20. Erythrocyte Osmotic Fragility and Excitability Score in Rabbit fed Hibiscus Sabdariffa in Graded Level.

    PubMed

    Adenkola, A Y; Oluremi, O I A

    2014-01-01

    This study was conducted for 10 weeks with the aim of investigating the erythrocyte membrane integrity as measured by erythrocyte osmotic fragility and excitability scores of rabbits fed graded level of Hibiscus sabdariffa calyx (HSC). Twenty weaners' rabbit of both sexes were used for the study and were placed on four experimental diets which contain the following percentages of HSC 0 %, 25 %, 50 %, 75 %, as feed additive and were added at 0 g, 62.5 g, 125 g, 187.5 g designated as T1, T2, T3 and T4 experimental diets. Excitability scores were measured weekly as described by Voisnet et al. (1997). At the end of the experiment, the rabbits were slaughtered by severing the jugular vein. A Blood sample (2 ml) was collected from each rabbit into sampled bottles, containing the Na EDTA as anticoagulant for hematological analysis. Packed cell volume (PCV) Haemoglobin concentration (Hb), Total red blood cell (RBC) count, Total leukocyte count as well as differential leukocyte was determined using standard method. The percentage haemolysis recorded at 0.3 % to 0.8 % was significantly (P < 0.05) higher in rabbits in T1 compared to the remaining 3 diets. The result of excitability score shows that rabbit on diet 1 and 2 had a lower value which was significantly (P < 0.05) lower than rabbits on diets 3 and 4 with a value of 65.5 ± 5.0 and 70.00 ± 5.50 % respectively. In conclusion this study demonstrated for the first time that chronic administration of HSC improves haematological parameters, brain mood and function as well as maintaining erythrocyte membrane integrity. PMID:26196576

  1. Environmental assessment of an alkyl dimethyl benyzl ammonium chloride (ADBAC) based mollusicide using laboratory tests

    SciTech Connect

    Dobbs, M.G.; Cherry, D.S.; Scott, J.C.; Petrille, J.C.

    1995-06-01

    A series of acute and chronic toxicity tests were conducted to estimate the potential environmental impact of n-alkyl dimethyl benzyl ammonium chloride (ADBAC) when used to control zebra mussels and other types of macrofouling organism in industrial cooling systems. The ADBAC-based molluscicide was tested as pure product and often detoxification with bentonite clay. Six flow-through acute tests were conducted to estimate the toxicity of ADBAC. In addition three chronic toxicity tests using Pimephales promelas, Daphnia magna and Selenastrum capricornutum were carried out to evaluate the efficacy of complexing the ADBAC-based molluscicide with a bentonite clay as a detoxification strategy. A 29-day CO{sub 2} Production test was also conducted to evaluate the biodegradability of the molluscicide. Of the six species tested in acute flow-through experiments, D. magna (LC{sub 50} = 0.02 mg ADBAC/L) was the most sensitive species followed by Mysidopsis bahia (LC{sub 50} = 0.08 mg ADBAC/L), Menidia beryllina (LC{sub 50} = 0.88 mg ADBAC/L), P. promelas (LC{sub 50} = 0.36 mg ADBAC/L), Cyprinodon variegatus (LC{sub 50} = 0.88 mg ADBAC/L), and Oncorhynchus mykiss (LC{sub 50} = 1.01 mg ADBAC/L). In the detoxification studies the three test species were exposed to treatment levels of: 0:0, 2.5:0, 2.5:25, 2.5:37.5, 2.5:50, 2.5:75, and 0:75 as mg/L ADBAC:clay. Bentonite clay was found to be an effective detoxification agent for this molluscicide at all treatment levels, except for the 2.5:25 treatment. In addition, a biodegradation study showed that the ADBAC-based molluscicide was readily biodegradable by unacclimated activated sludge microorganisms releasing 65.9% of the theoretical possible CO{sub 2} after 29 days.

  2. A comparison of resident fish assemblages in managed and unmanaged coastal wetlands in North Carolina and South Carolina

    USGS Publications Warehouse

    Robinson, Kelly F.; Jennings, Cecil A.

    2014-01-01

    The dominant fish species within impounded coastal wetlands in the southeastern US may be different from the species that dominate natural marshes. We tested the hypothesis that resident fish assemblages inhabiting impounded coastal wetlands in South Carolina would differ from resident assemblages in natural marshes of the southeastern United States. We used rarefied species richness, Shannon's H' diversity,J' evenness, Morisita's index of similarity, and the percent similarity index to compare resident fish assemblages from two impoundments to 12 open-marsh resident fish assemblages from previously published studies in North and South Carolina. We used rotenone to sample fish assemblages in impoundments. The assemblages in natural marsh habitat had been sampled with rotenone and seines. We classified comparisons yielding a similarity index ≥0.50 as moderately similar and those with an index ≥0.75 as very similar. Fifty-three percent of the among-impoundment comparisons (Morisita's index) were at least moderately similar, whereas 7% of impoundment—natural marsh comparisons were moderately similar. A difference in tidal influence was the only parameter in the best-fitting model describing the observed Morisita's indices. The index of similarity decreased by 63% when tidal influence differed between compared assemblages. Species richness and diversity were greater in impoundments than natural marshes, but evenness was similar between habitat types. Our results support the hypothesis that resident fish assemblages in impounded wetlands and natural marshes are different, and suggest that a degree of tidal influence is the most important factor behind the difference.

  3. Enhanced immune responses against Japanese encephalitis virus using recombinant adenoviruses coexpressing Japanese encephalitis virus envelope and porcine interleukin-6 proteins in mice.

    PubMed

    Liu, Hanyang; Wu, Rui; Liu, Kai; Yuan, Lei; Huang, Xiaobo; Wen, Yiping; Ma, Xiaoping; Yan, Qigui; Zhao, Qin; Wen, Xintian; Cao, Sanjie

    2016-08-15

    Japanese encephalitis is a reproductive disorder caused by Japanese encephalitis virus (JEV) in swine. Previous studies have demonstrated that recombinant adenovirus serotype 5 (Ad5) may be a potential vaccine candidate because it can express JEV envelope epitopes and induce immune responses against JEV. Still, it will be necessary to develop an adjuvant that can enhance both humoral and cellular immune responses to the recombinant antigen delivered by non-replicating Ad5. In this study, we investigated the systemic immune responses of BALB/c mice immunized with recombinant adenovirus expressing JEV envelope epitopes in combination with porcine interleukin-6 (rAdE-IL-6).The rAdE-IL-6 immunized group had the highest titers of anti-JEV antibody as detected by an enzyme-linked immunosorbent assay (ELISA), as well as the highest levels of neutralizing antibody (1:75) as detected by a serum neutralization test. Similarly, higher concentrations of interferon-gamma (834.7pg/ml) and interleukin-6 (IL-6) (229.7pg/ml) were detected in the rAdE-IL-6 group using an ELISA assay. These data indicate that immunized BALB/c induce a strong cellular response against rAdE-IL-6. Furthermore, after challenge with the virulent JEV SCYA201201 strain, the rAdE-IL-6 group generated an immune protective response 70% greater than that of the control group, indicating that rAdE-IL-6 induced a protective immune response against JEV challenge in mice. The results from this study demonstrated that IL-6 is a strong adjuvant that can enhance both humoral and cellular immune responses in mice. Furthermore, a recombinant adenovirus coexpressing JEV envelope epitopes and porcine IL-6 protein may be an effective vaccine in animals. PMID:27235810

  4. Respiratory morbidity among welders in the shipbuilding industry, Goa

    PubMed Central

    Bhumika, Nateshan; Prabhu, Ganapati Vasant; Ferreira, Agnelo Menino; Kulkarni, Manoj Kumar; Vaz, Frederick Satiro; Singh, Zile

    2012-01-01

    Context: Welding is pivotal in shipbuilding. The fumes and gases involved in welding may cause respiratory morbidity. Aim: To study the prevalence of respiratory morbidity (RM) among welders vis à vis among nonwelders and its association with certain relevant factors. Settings and Design: A cross-sectional study of 276 welders and 276 nonwelders was conducted in the shipbuilding industry. Materials and Methods: An interviewer-administered questionnaire was followed by spirometric examination. Statistical Analysis: Odds ratio and its 95% CI and two-way ANOVA. Results: Prevalence of RM was found to be significantly higher among welders compared to nonwelders (who were comparable in age, duration of employment (DOE) and smoking habits,) with odds ratio (OR) of 1.78 (95% confidence interval (CI):1.20-2.63). Obstructive type of RM was predominant in both welders (26% (n = 73)) and nonwelders (17% (n = 49)) with welders being at a significantly higher risk (OR = 1.66 (95%: 1.10-2.49)). RM was commoner after the 40 years of age or after 20 years of employment in both groups. Smoking was associated with RM among welders (OR = 1.48, 95% CI: 1.24-1.75) as well as nonwelders (OR = 2.83, 95% CI: 2.26-3.54). Work-related respiratory symptoms (WRRS) was not found to be related to RM (OR = 1.69, 95% CI: 1.00-2.84). Consistent use of personal protective equipment (PPE) was protective against RM in welders (OR = 0.33, 95% CI: 0.28-0.37). Conclusion: Welders had a greater burden of RM and this was related to increasing age, DOE, smoking and inconsistent use of PPE. WRRS were not indicative of RM. PMID:23580835

  5. THE BRIGHTEST OF REIONIZING GALAXIES SURVEY: DESIGN AND PRELIMINARY RESULTS

    SciTech Connect

    Trenti, M.; Bradley, L. D.; Stiavelli, M.; MacKenty, J. W.; Oesch, P.; Carollo, C. M.; Treu, T.; Bouwens, R. J.; Illingworth, G. D.; Shull, J. M.

    2011-02-01

    We present the first results on the search for very bright (M{sub AB} {approx} -21) galaxies at redshift z {approx} 8 from the Brightest of Reionizing Galaxies (BoRG) survey. BoRG is a Hubble Space Telescope Wide Field Camera 3 (WFC3) pure-parallel survey that is obtaining images on random lines of sight at high Galactic latitudes in four filters (F606W, F098M, F125W, and F160W), with integration times optimized to identify galaxies at z {approx}> 7.5 as F098M dropouts. We discuss here results from a search area of approximately 130 arcmin{sup 2} over 23 BoRG fields, complemented by six other pure-parallel WFC3 fields with similar filters. This new search area is more than two times wider than previous WFC3 observations at z {approx} 8. We identify four F098M-dropout candidates with high statistical confidence (detected at greater than 8{sigma} confidence in F125W). These sources are among the brightest candidates currently known at z {approx} 8 and approximately 10 times brighter than the z = 8.56 galaxy UDFy-38135539. They thus represent ideal targets for spectroscopic follow-up observations and could potentially lead to a redshift record, as our color selection includes objects up to z {approx} 9. However, the expected contamination rate of our sample is about 30% higher than typical searches for dropout galaxies in legacy fields, such as the GOODS and HUDF, where deeper data and additional optical filters are available to reject contaminants.

  6. Lavage of the Uterine Cavity for Molecular Detection of Müllerian Duct Carcinomas: A Proof-of-Concept Study

    PubMed Central

    Maritschnegg, Elisabeth; Wang, Yuxuan; Pecha, Nina; Horvat, Reinhard; Van Nieuwenhuysen, Els; Vergote, Ignace; Heitz, Florian; Sehouli, Jalid; Kinde, Isaac; Diaz, Luis A.; Papadopoulos, Nickolas; Kinzler, Kenneth W.; Vogelstein, Bert; Speiser, Paul; Zeillinger, Robert

    2015-01-01

    Purpose Type II ovarian cancer (OC) and endometrial cancer (EC) are generally diagnosed at an advanced stage, translating into a poor survival rate. There is increasing evidence that Müllerian duct cancers may exfoliate cells. We have established an approach for lavage of the uterine cavity to detect shed cancer cells. Patients and Methods Lavage of the uterine cavity was used to obtain samples from 65 patients, including 30 with OC, five with EC, three with other malignancies, and 27 with benign lesions involving gynecologic organs. These samples, as well as corresponding tumor tissue, were examined for the presence of somatic mutations using massively parallel sequencing (next-generation sequencing) and, in a subset, singleplex analysis. Results The lavage technique could be applied successfully, and sufficient amounts of DNA were obtained in all patients. Mutations, mainly in TP53, were identified in 18 (60%) of 30 lavage samples of patients with OC using next-generation sequencing. Singleplex analysis of mutations previously determined in corresponding tumor tissue led to further identification of six patients. Taken together, in 24 (80%) of 30 patients with OC, specific mutations could be identified. This also included one patient with occult OC. All five analyzed lavage specimens from patients with EC harbored mutations. Eight (29.6%) of 27 patients with benign lesions tested positive for mutations, six (75%) as a result of mutations in the KRAS gene. Conclusion This study proved that tumor cells from ovarian neoplasms are shed and can be collected via lavage of the uterine cavity. Detection of OC and EC and even clinically occult OC was achieved, making it a potential tool of significant promise for early diagnosis. PMID:26552420

  7. Effect of thin emitter set-back layer on GaAs delta-doped emitter bipolar junction transistor

    NASA Astrophysics Data System (ADS)

    Lew, K. L.; Yoon, S. F.

    2005-05-01

    GaAs delta-doped emitter bipolar junction transistors (δ-BJT) with different emitter set-back layer thicknesses of 10to50nm were fabricated to study the emitter set-back layer thickness effect on device dc performance. We found that the current gain decreases following decrease in the emitter set-back layer thickness. A detailed analysis was performed to explain this phenomenon, which is believed to be caused by reduction of the effective barrier height in the δ-BJT. This is due to change in the electric-field distribution in the delta-doped structure caused by the built-in potential of the base-emitter (B-E ) junction. Considering the recombination and barrier height reduction effects, the thickness of the emitter set-back layer should be designed according to the B-E junction depletion width with a tolerance of ±5nm. The dc performance of a δ-BJT designed based on this criteria is compared to that of a Al0.25Ga0.75As /GaAs heterojunction bipolar transistor (HBT). Both devices employed base doping of 2×1019cm-3 and base-to-emitter doping ratio of 40. Large emitter area (AE≈1.6×10-5cm-2) and small emitter area (AE≈1.35×10-6cm-2) device current gains of 40 and 20, respectively, were obtained in both types of transistors passivated by (NH4)2S treatment. The measured current gain of the GaAs δ-BJT is the highest reported for a homojunction device with such high base-to-emitter doping ratio normally used in HBT devices.

  8. Enantioselective transesterification by Candida antarctica Lipase B immobilized on fumed silica.

    PubMed

    Kramer, Martin; Cruz, Juan C; Pfromm, Peter H; Rezac, Mary E; Czermak, Peter

    2010-10-01

    Enzymatic catalysis to produce molecules such as perfumes, flavors, and fragrances has the advantage of allowing the products to be labeled "natural" for marketing in the U.S., in addition to the exquisite selectivity and stereoselectivity of enzymes that can be an advantage over chemical catalysis. Enzymatic catalysis in organic solvents is attractive if solubility issues of reactants or products, or thermodynamic issues (water as a product in esterification) complicate or prevent aqueous enzymatic catalysis. Immobilization of the enzyme on a solid support can address the generally poor solubility of enzymes in most solvents. We have recently reported on a novel immobilization method for Candida antarctica Lipase B on fumed silica to improve the enzymatic activity in hexane. This research is extended here to study the enantioselective transesterification of (RS)-1-phenylethanol with vinyl acetate. The maximum catalytic activity for this preparation exceeded the activity (on an equal enzyme amount basis) of the commercial Novozyme 435(®) significantly. The steady-state conversion for (R)-1-phenylethanol was about 75% as confirmed via forward and reverse reaction. The catalytic activity steeply increases with increasing nominal surface coverage of the support until a maximum is reached at a nominal surface coverage of 230%. We hypothesize that the physical state of the enzyme molecules at a low surface coverage is dominated in this case by detrimental strong enzyme-substrate interactions. Enzyme-enzyme interactions may stabilize the active form of the enzyme as surface coverage increases while diffusion limitations reduce the apparent catalytic performance again at multi-layer coverage. The temperature-, solvent-, and long-term stability for CALB/fumed silica preparations showed that these preparations can tolerate temperatures up to 70°C, continuous exposure to solvents, and long-term storage. PMID:20670664

  9. Simultaneous quantification of Pacific ciguatoxins in fish blood using liquid chromatography-tandem mass spectrometry.

    PubMed

    Mak, Yim Ling; Wu, Jia Jun; Chan, Wing Hei; Murphy, Margaret B; Lam, James C W; Chan, Leo L; Lam, Paul K S

    2013-04-01

    Ciguatera fish poisoning (CFP) is a food intoxication caused by exposure to ciguatoxins (CTXs) in coral reef fish. Rapid analytical methods have been developed recently to quantify Pacific-CTX-1 (P-CTX-1) in fish muscle, but it is destructive and can cause harm to valuable live coral reef fish. Also fish muscle extract was complex making CTX quantification challenging. Not only P-CTX-1, but also P-CTX-2 and P-CTX-3 could be present in fish, contributing to ciguatoxicity. Therefore, an analytical method for simultaneous quantification of P-CTX-1, P-CTX-2, and P-CTX-3 in whole blood of marketed coral reef fish using sonication, solid-phase extraction (SPE), and liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed. The optimized method gave acceptable recoveries of P-CTXs (74-103 %) in fish blood. Matrix effects (6-26 %) in blood extracts were found to be significantly reduced compared with those in muscle extracts (suppressed by 34-75 % as reported in other studies), thereby minimizing potential for false negative results. The target P-CTXs were detectable in whole blood from four coral reef fish species collected in a CFP-endemic region. Similar trends in total P-CTX levels and patterns of P-CTX composition profiles in blood and muscle of these fish were observed, suggesting a relationship between blood and muscle levels of P-CTXs. This optimized method provides an essential tool for studies of P-CTX pharmacokinetics and pharmacodynamics in fish, which are needed for establishing the use of fish blood as a reliable sample for the assessment and control of CFP. PMID:23392409

  10. The energy and spectral characteristics of a room-temperature pulsed laser on a ZnS:Fe2+ polycrystal

    NASA Astrophysics Data System (ADS)

    Firsov, K. N.; Gavrishchuk, E. M.; Ikonnikov, V. B.; Kazantsev, S. Yu; Kononov, I. G.; Kotereva, T. V.; Savin, D. V.; Timofeeva, N. A.

    2016-04-01

    The energy and spectral characteristics of a laser on a ZnS:Fe2+ polycrystal operating at room temperature have been studied. The laser was pumped by a non-chain electro-discharge HF laser with a full-width at half-maximum pulse duration of ~140 ns. The diameter of the pumping radiation spot on the crystal surface was 3.8 mm. The two-sided diffuse doping of a polycrystalline CVD-ZnS sample with the surfaces preliminarily coated by high-purity iron films was performed in the process of hot isostatic pressing (HIP) in an argon atmosphere at a pressure of 100 MPa and temperature of 1290 °С. Increasing the duration of the HIP treatment from 54 h to 72 h made it possible to obtain twice the doping depth, and correspondingly, twice the length of active medium. As a result, the slope laser efficiency with respect to the absorbed energy was raised by a factor of 1.75 as compared to the value obtained in our earlier work with a polycrystalline sample. The generation energy was 25 mJ at a slope efficiency of η slope  =  35%. It was established that the generation spectra of the laser with a non-selective resonator have a linear structure with intervals between the neighboring lines of δ λ   ≈  6 ÷ 8 nm, which is spurious for solid-state lasers. The spectral structure observed is not related to the elements inside the resonator, which might form Fabry-Perot interferometers.