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Sample records for k87 rb feshbach

  1. Isotopic shift of atom-dimer Efimov resonances in K-Rb mixtures: Critical effect of multichannel Feshbach physics

    CERN Document Server

    Kato, K; Kobayashi, J; Julienne, P S; Inouye, S

    2016-01-01

    The multichannel Efimov physics is investigated in ultracold heteronuclear admixtures of K and Rb atoms. We observe a shift in the scattering length where the first atom-dimer resonance appears in the $^{41}$K-$^{87}$Rb system relative to the position of the previously observed atom-dimer resonance in the $^{40}$K-$^{87}$Rb system. This shift is well explained by our calculations with a three-body model including the van der Waals interactions, and, more importantly, the multichannel spinor physics. With only minor difference in the atomic masses of the admixtures, the shift in the atom-dimer resonance positions can be cleanly ascribed to the isolated and overlapping Feshbach resonances in the $^{40}$K-$^{87}$Rb and $^{41}$K-$^{87}$Rb systems, respectively. Our study demonstrates the role of the multichannel Feshbach physics in determining Efimov resonances in heteronuclear three-body systems.

  2. Formation of Ultracold NaRb Feshbach Molecules

    CERN Document Server

    Wang, Fudong; Li, Xiaoke; Zhu, Bing; Chen, Jun; Wang, Dajun

    2015-01-01

    We report the creation of ultracold bosonic $^{23}$Na$^{87}$Rb Feshbach molecules via magneto-association. By ramping the magnetic field across an interspecies Feshbach resonance, at least 4000 molecules can be produced out of the near degenerate ultracold mixture. Fast loss due to inelastic atom-molecule collisions is observed, which limits the pure molecule number, after residual atoms removal, to 1700. The pure molecule sample can live for 21.8(8) ms in the optical trap, long enough for future molecular spectroscopy studies toward coherently transferring to the singlet ro-vibrational ground state, where these molecules are stable against chemical reaction and have a permanent electric dipole moment of 3.3 Debye. We have also measured the Feshbach molecule's binding energy near the Feshbach resonance by the oscillating magnetic field method and found these molecules have a large closed-channel fraction.

  3. Formation of ultracold NaRb Feshbach molecules

    Science.gov (United States)

    Wang, Fudong; He, Xiaodong; Li, Xiaoke; Zhu, Bing; Chen, Jun; Wang, Dajun

    2015-03-01

    We report the creation of ultracold bosonic 23Na87Rb Feshbach molecules via magneto-association. By ramping the magnetic field across an interspecies Feshbach resonance (FR), at least 4000 molecules can be produced out of the near degenerate ultracold mixture. Fast loss due to inelastic atom-molecule collisions is observed, which limits the pure molecule number, after residual atoms removal, to 1700. The pure molecule sample can live for 21.8(8) ms in the optical trap, long enough for future molecular spectroscopy studies toward coherently transferring to the singlet ro-vibrational ground state, where these molecules are stable against chemical reaction and have a permanent electric dipole moment of 3.3 Debye. We have also measured the Feshbach molecule’s binding energy near the FR by the oscillating magnetic field method and found these molecules have a large closed-channel fraction.

  4. Observation of broad p-wave Feshbach resonances in ultracold $^{85}$Rb-$^{87}$Rb mixtures

    CERN Document Server

    Dong, Shen; Shen, Chuyang; Wu, Yewei; Tey, Meng Khoon; You, Li; Gao, Bo

    2016-01-01

    We observe new Feshbach resonances in ultracold mixtures of $^{85}$Rb and $^{87}$Rb atoms in the $^{85}$Rb$|2, +2\\rangle$+$^{87}$Rb$|1, +1\\rangle$ and $^{85}$Rb$|2, -2\\rangle$+$^{87}$Rb$|1, -1\\rangle$ scattering channels. The positions and properties of the resonances are predicted and characterized using the semi-analytic multichannel quantum-defect theory by Gao. Of particular interest, a number of broad entrance-channel dominated p-wave resonances are identified, implicating exciting opportunities for studying a variety of p-wave interaction dominated physics.

  5. Quantum Defect Theory description of weakly bound levels and Feshbach resonances in LiRb

    CERN Document Server

    Pérez-Ríos, Jesús; Chen, Yong P; Greene, Chris H

    2014-01-01

    The multichannel quantum defect theory (MQDT) in combination with the frame transformation (FT) approach is applied to model the Fano-Feshbach resonances measured for $^{7}$Li$^{87}$Rb and $^{6}$Li$^{87}$Rb [Marzok {\\it et al.} Phys. Rev. A {\\bf 79} 012717 (2009)]. The MQDT results show a level of accuracy comparable to that of previous models based on direct, fully numerical solutions of the the coupled channel Schr\\"odinger equations (CC). Here, energy levels deduced from 2-photon photoassociation spectra for $^{7}$Li$^{85}$Rb are assigned by applying the MQDT approach, obtaining the bound state energies for the coupled channel problem. Our results confirm that MQDT yields a compact description of photoassociation observables as well as the Fano-Feshbach resonance positions and widths.

  6. Role of Molecular Dissociation in Feshbach-Interacting 85Rb Condensates

    CERN Document Server

    Mackie, M; Javanainen, J; Mackie, Matt; Suominen, Kalle-Antti; Javanainen, Juha

    2002-01-01

    Recent Feshbach-resonance experiments with 85Rb Bose-Einstein condensates have led to a host of unexplained results: dramatic losses of condensate atoms for an across-resonance sweep of the magnetic field, a collapsing condensate with a burst of atoms emanating from the remnant condensate, increased losses for decreasing interaction times--until very short times are reached, and coherent oscillations between remnant and burst atoms. In particular, the amplitude of the remnant-burst oscillations, and the corresponding missing atoms, have prompted speculation as to the formation of a molecular condensate. Using a minimal mean-field model, we find that rogue dissociation, molecular dissociation to noncondensate atom pairs, is qualitatively implicated as the physical mechanism responsible for these observations, although very little molecular condensate is formed. Refining the model provides excellent quantitative agreement with the experimental remnant-burst oscillations, and the fraction of molecular condensate...

  7. Enhanced association and dissociation of heteronuclear Feshbach molecules in a microgravity environment

    CERN Document Server

    D'Incao, J P; Elliott, E; Williams, J R

    2016-01-01

    We study the association and dissociation dynamics of weakly bound heteronuclear Feshbach molecules using transverse RF-fields for expected parameters accessible through the microgravity environment of NASA's Cold Atom Laboratory (CAL) aboard the International Space Station, including temperatures at or below nK and atomic densities as low as $10^8$/cm$^3$. We show that under such conditions, thermal and loss effects can be greatly suppressed resulting in high efficiency in both association and dissociation of Feshbach molecules with mean size exceeding 10$^4a_0$, and allowing for the coherence in atom-molecule transitions to be clearly observable. Our theoretical model for heteronuclear mixtures includes thermal, loss, and density effects in a simple and conceptually clear manner. We derive the temperature, density and scattering length regimes of $^{41}$K-$^{87}$Rb that allow optimal association/dissociation efficiency with minimal heating and loss to guide future experiments with ultracold atomic gases in ...

  8. Association and dissociation of Feshbach molecules in a microgravity environment

    Science.gov (United States)

    D'Incao, Jose P.; Willians, Jason R.

    2016-05-01

    NASA's Cold Atom Laboratory (CAL) is a multi-user facility scheduled for launch to the ISS in 2017. Our flight experiments with CAL will characterize and mitigate leading-order systematics in dual-atomic-species atom interferometers in microgravity relevant for future fundamental physics missions in space. Here, we study the RF association and dissociation of weakly bound heteronuclear Feshbach molecules for expected parameters relevant for the microgravity environment of CAL. This includes temperatures on the pico-Kelvin range and atomic densities as low as 108/ cm3. We show that under such conditions, thermal and loss effects can be greatly suppressed, resulting in high efficiency in both association and dissociation of extremely weakly bound Feshbach molecules and allowing for high accuracy determination coherent properties of such processes. Our theoretical model for 41 K-87 Rb mixture includes thermal, loss, and density effects in a simple and conceptually clear manner. We derive several conditions in terms of the temperature, density and scattering lengths, determining the regime in which one can achieve efficient association and dissociation. This research is supported by the National Aeronautics and Space Administration.

  9. Photonic Feshbach resonance

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Feshbach resonance is a resonance for two-atom scattering with two or more channels,in which a bound state is achieved in one channel.We show that this resonance phenomenon not only exists during the collisions of massive particles,but also emerges during the coherent transport of massless particles,that is,photons confined in the coupled resonator arrays linked by a separated cavity or a tunable two level system(TLS).When the TLS is coupled to one array to form a bound state in this setup,the vanishing transmission appears to display the photonic Feshbach resonance.This process can be realized through various experimentally feasible solid state systems,such as the couple defected cavities in photonic crystals and the superconducting qubit coupled to the transmission line.The numerical simulation based on the finite-different time-domain(FDTD) method confirms our assumption about the physical implementation.

  10. Rydberg optical Feshbach resonances in cold gases

    CERN Document Server

    Sándor, Nóra; Julienne, Paul S; Pupillo, Guido

    2016-01-01

    We propose a novel scheme to efficiently tune the scattering length of two colliding ground-state atoms by off-resonantly coupling the scattering-state to an excited Rydberg-molecular state using laser light. For the s-wave scattering of two colliding ${^{87}}\\mathrm{Rb}$ atoms, we demonstrate that the effective optical length and pole strength of this Rydberg optical Feshbach resonance can be tuned over several orders of magnitude, while incoherent processes and losses are minimised. Given the ubiquity of Rydberg molecular states, this technique should be generally applicable to homo-nuclear atomic pairs as well as to atomic mixtures with s-wave (or even p-wave) scattering.

  11. Above-threshold scattering about a Feshbach resonance for ultracold atoms in an optical collider.

    Science.gov (United States)

    Horvath, Milena S J; Thomas, Ryan; Tiesinga, Eite; Deb, Amita B; Kjærgaard, Niels

    2017-09-06

    Ultracold atomic gases have realized numerous paradigms of condensed matter physics, where control over interactions has crucially been afforded by tunable Feshbach resonances. So far, the characterization of these Feshbach resonances has almost exclusively relied on experiments in the threshold regime near zero energy. Here, we use a laser-based collider to probe a narrow magnetic Feshbach resonance of rubidium above threshold. By measuring the overall atomic loss from colliding clouds as a function of magnetic field, we track the energy-dependent resonance position. At higher energy, our collider scheme broadens the loss feature, making the identification of the narrow resonance challenging. However, we observe that the collisions give rise to shifts in the center-of-mass positions of outgoing clouds. The shifts cross zero at the resonance and this allows us to accurately determine its location well above threshold. Our inferred resonance positions are in excellent agreement with theory.Studies on energy-dependent scattering of ultracold atoms were previously carried out near zero collision energies. Here, the authors observe a magnetic Feshbach resonance in ultracold Rb collisions for above-threshold energies and their method can also be used to detect higher partial wave resonances.

  12. Feshbach resonances in ultracold {sup 39}K

    Energy Technology Data Exchange (ETDEWEB)

    D' Errico, Chiara [LENS and Dipartimento di Fisica, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Zaccanti, Matteo [LENS and Dipartimento di Fisica, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Fattori, Marco [Museo Storico della Fisica e Centro Studi e Ricerche ' Enrico Fermi' , Compendio del Viminale, 00184 Roma (Italy); Roati, Giacomo [LENS and Dipartimento di Fisica, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Inguscio, Massimo [LENS and Dipartimento di Fisica, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Modugno, Giovanni [LENS and Dipartimento di Fisica, Universita di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino (Italy); Simoni, Andrea [Laboratoire de Physique des Atomes, Lasers, Molecules et Surfaces, UMR 6627 du CNRS and Universite de Rennes, 35042 Rennes Cedex (France)

    2007-07-15

    We discover several magnetic Feshbach resonances in collisions of ultracold {sup 39}K atoms, by studying atom losses and molecule formation. Accurate determination of the magnetic-field resonance locations allows us to optimize a quantum collision model for potassium isotopes. We employ the model to predict the magnetic-field dependence of scattering lengths and of near-threshold molecular levels. Our findings will be useful to plan future experiments on ultracold {sup 39}K atoms and molecules.

  13. Creation of ultracold $^{87}$RbCs molecules in the rovibrational ground state

    CERN Document Server

    Molony, Peter K; Ji, Zhonghua; Lu, Bo; Köppinger, Michael P; Sueur, C Ruth Le; Blackley, Caroline L; Hutson, Jeremy M; Cornish, Simon L

    2014-01-01

    We report the creation of a sample of over 1000 ultracold $^{87}$RbCs molecules in the lowest rovibrational ground state, from an atomic mixture of $^{87}$Rb and Cs, by magnetoassociation on an interspecies Feshbach resonance followed by stimulated Raman adiabatic passage (STIRAP). We measure the binding energy of the RbCs molecule to be $h c \\times 3811.576(1)$ cm$^{-1}$ and the $|\

  14. Thermodynamics of the Optical Feshbach Resonance Effect

    CERN Document Server

    Blatt, S; Bloom, B J; Williams, J R; Thomsen, J W; Julienne, P S; Ye, J

    2011-01-01

    Using a narrow intercombination line in alkaline earth atoms to mitigate large inelastic losses, we explore the Optical Feshbach Resonance effect in an ultracold gas of bosonic $^{88}$Sr. A systematic measurement of several resonances allows precise determinations of the OFR strength and scaling law, in agreement with coupled-channels theory. Resonant enhancement of the complex scattering length leads to thermodynamic behavior mediated by elastic and inelastic collisions in an otherwise ideal gas. OFR could be used to control atomic interactions with high spatial and time resolution.

  15. Feshbach Projection Formalism for Open Quantum Systems

    Science.gov (United States)

    Chruściński, Dariusz; Kossakowski, Andrzej

    2013-08-01

    We provide a new approach to open quantum systems which is based on the Feshbach projection method. Instead of looking for a master equation for the dynamical map acting in the space of density operators we provide the corresponding equation for the evolution in the Hilbert space of the amplitude operators. Its solution enables one to construct a legitimate quantum evolution (completely positive and trace preserving). Our approach, contrary to the standard Nakajima-Zwanzig method, allows for a series of consistent approximations resulting in a legitimate quantum evolution. The new scheme is illustrated by the well-known spin-boson model beyond the rotating wave approximation. It is shown that the presence of counterrotating terms dramatically changes the asymptotic evolution of the system.

  16. Measurement of optical Feshbach resonances in an ideal gas.

    Science.gov (United States)

    Blatt, S; Nicholson, T L; Bloom, B J; Williams, J R; Thomsen, J W; Julienne, P S; Ye, J

    2011-08-12

    Using a narrow intercombination line in alkaline earth atoms to mitigate large inelastic losses, we explore the optical Feshbach resonance effect in an ultracold gas of bosonic (88)Sr. A systematic measurement of three resonances allows precise determinations of the optical Feshbach resonance strength and scaling law, in agreement with coupled-channel theory. Resonant enhancement of the complex scattering length leads to thermalization mediated by elastic and inelastic collisions in an otherwise ideal gas. Optical Feshbach resonance could be used to control atomic interactions with high spatial and temporal resolution.

  17. Global transmission coefficients in Hauser-Feshbach calculations for astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Rauscher, T. [Inst. fuer Physik, Univ. Basel, Basel (Switzerland)

    1998-06-01

    The current status of optical potentials employed in the prediction of thermonuclear reaction rates for astrophysics in the Hauser-Feshbach formalism is discussed. Special emphasis is put on {alpha}+nucleus potentials. Further experimental efforts are motivated. (orig.)

  18. K87Q METAR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — METAR is a routine scheduled observation and is the primary observation code used in the United States to satisfy requirements for reporting surface meteorological...

  19. Exploring strategies for the production of ultracold RbYb molecules in conservative traps

    Energy Technology Data Exchange (ETDEWEB)

    Bruni, Cristian

    2015-07-14

    Within the scope of this thesis, the production of ultracold molecules at a temperature of a few μK with various isotopes of rubidium (Rb) and ytterbium (Yb) was examined by means of photoassociation spectroscopy and magnetic Feshbach resonances in combined conservative traps. The long-term goal of this experiment is the production of ultracold RbYb molecules in the rovibronic ground state. It was possible to produce electronically excited {sup 87}Rb {sup 176}Yb molecules in a novel hybrid trap (HT) at a combined temperature of 1.7 μK by means of 1-photon photoassociation close to the Rb D1 line at 795 nm. This HT takes advantage of the different magnetic properties of Rb and Yb and allows for independent trapping and manipulation of the atomic species. It combines an Ioffe-Pritchard type magnetic trap for Rb and a near-resonant optical dipole trap for Yb. The excited molecular {sup 2}Π{sub 1/2} state could be characterized further extending previous works in a combined MOT and vibrational levels reaching binding energies up to E{sub b}=-h x 2.2 THz could be assigned by trap-loss spectroscopy. Almost every detected vibrational state consists of two resonances that could be assigned to the molecular analogue of the hyperfine structure of {sup 87}Rb. An important experimental observation is a decrease in hyperfine splitting with increasing binding energy of a vibrational level. For the deepest found vibrational state the hyperfine splitting amounts only 70 % of the atomic value (817 MHz) which emphasizes a gradual passage from weakly to tightly bound molecules. Furthermore, detailed attempts were undertaken to induce magnetic Feshbach resonances in {sup 85}Rb and different Yb isotopes, especially {sup 171}Yb in a crossed optical dipole trap at 1064 nm at temperatures of 10 μK. For this purpose, a homogeneous magnetic field was applied and scanned in small steps over the range of 495 G ∼ 640 G. Unfortunately, our efforts were without success. Additionally, well

  20. Asymptotic-bound-state model for Feshbach resonances

    NARCIS (Netherlands)

    Tiecke, T.G.; Goosen, M.R.; Walraven, J.T.M.; Kokkelmans, S.J.J.M.F.

    2010-01-01

    We present an asymptotic-bound-state model which can be used to accurately describe all Feshbach resonance positions and widths in a two-body system. With this model we determine the coupled bound states of a particular two-body system. The model is based on analytic properties of the two-body

  1. Ultracold fermion cooling cycle using heteronuclear Feshbach resonances

    DEFF Research Database (Denmark)

    Morales, M. A.; Nygaard, Nicolai; Williams, J. E.

    2005-01-01

    We consider an ideal gas of Bose and Fermi atoms in a harmonic trap, with a Feshbach resonance in the interspecies atomic scattering that can lead to the formation of fermionic molecules. We map out the phase diagram for this three-component mixture in chemical and thermal equilibrium. Considering...

  2. Charge transfer in ultracold gases via Feshbach resonances

    Science.gov (United States)

    Gacesa, Marko; Côté, Robin

    2017-06-01

    We investigate the prospects of using magnetic Feshbach resonance to control charge exchange in ultracold collisions of heteroisotopic combinations of atoms and ions of the same element. The proposed treatment, readily applicable to alkali or alkaline-earth metals, is illustrated on cold collisions of +9Be and 10Be. Feshbach resonances are characterized by quantum scattering calculations in a coupled-channel formalism that includes non-Born-Oppenheimer terms originating from the nuclear kinetic operator. Near a resonance predicted at 322 G, we find the charge exchange rate coefficient to rise from practically zero to values greater than 10-12cm3 /s. Our results suggest controllable charge exchange processes between different isotopes of suitable atom-ion pairs, with potential applications to quantum systems engineered to study charge diffusion in trapped cold atom-ion mixtures and emulate many-body physics.

  3. Orbital Feshbach Resonance in Alkali-Earth Atoms.

    Science.gov (United States)

    Zhang, Ren; Cheng, Yanting; Zhai, Hui; Zhang, Peng

    2015-09-25

    For a mixture of alkali-earth atomic gas in the long-lived excited state ^{3}P_{0} and the ground state ^{1}S_{0}, in addition to nuclear spin, another "orbital" index is introduced to distinguish these two internal states. In this Letter we propose a mechanism to induce Feshbach resonance between two atoms with different orbital and nuclear spin quantum numbers. Two essential ingredients are the interorbital spin-exchange process and orbital dependence of the Landé g factors. Here the orbital degrees of freedom plays a similar role as the electron spin degree of freedom in magnetic Feshbach resonance in alkali-metal atoms. This resonance is particularly accessible for the ^{173}Yb system. The BCS-BEC crossover in this system requires two fermion pairing order parameters, and displays a significant difference compared to that in an alkali-metal system.

  4. Optical Feshbach Resonances: Field-Dressed Theory and Experimental Comparisons

    CERN Document Server

    Nicholson, T L; Bloom, B J; Williams, J R; Thomsen, J W; Ye, J; Julienne, P S

    2015-01-01

    Optical Feshbach resonances (OFRs) have generated significant experimental interest in recent years. These resonances are promising for many-body physics experiments, yet the practical application of OFRs has been limited. The theory of OFRs has been based on an approximate model that fails in important detuning regimes, and the incomplete theoretical understanding of this effect has hindered OFR experiments. We present the most complete theoretical treatment of OFRs to date, demonstrating important characteristics that must be considered in OFR experiments and comparing OFRs to the well studied case of magnetic Feshbach resonances. We also present a comprehensive treatment of the approximate OFR model, including a study of the range of validity for this model. Finally, we derive experimentally useful expressions that can be applied to real experimental data to extract important information about the resonance structure of colliding atoms.

  5. Ultracold fermion cooling cycle using heteronuclear Feshbach resonances

    DEFF Research Database (Denmark)

    Morales, M. A.; Nygaard, Nicolai; Williams, J. E.;

    2005-01-01

    We consider an ideal gas of Bose and Fermi atoms in a harmonic trap, with a Feshbach resonance in the interspecies atomic scattering that can lead to the formation of fermionic molecules. We map out the phase diagram for this three-component mixture in chemical and thermal equilibrium. Considering...... adiabatic association and dissociation of the molecules, we identify a possible cooling cycle, which in ideal circumstances can yield an exponential increase of the phase-space density....

  6. Matrix Continued Fraction Solution to the Relativistic Spin-0 Feshbach-Villars Equations

    Science.gov (United States)

    Brown, N. C.; Papp, Z.; Woodhouse, R.

    2016-03-01

    The Feshbach-Villars equations, like the Klein-Gordon equation, are relativistic quantum mechanical equations for spin-0 particles.We write the Feshbach-Villars equations into an integral equation form and solve them by applying the Coulomb-Sturmian potential separable expansion method. We consider boundstate problems in a Coulomb plus short range potential. The corresponding Feshbach-Villars CoulombGreen's operator is represented by a matrix continued fraction.

  7. The $d \\: ^3 \\Pi$ state of LiRb

    CERN Document Server

    Stevenson, I; Altaf, A; Chen, Y P; Elliott, D S

    2016-01-01

    We report our spectroscopic studies of the $d \\ ^3\\Pi$ state of ultra-cold $^7$Li$^{85}$Rb using resonantly-enhanced multi-photon ionization and depletion spectroscopy with bound-to-bound transitions originating from the metastable $a \\ ^3\\Sigma^+$ state. We evaluate the potential of this state for use as the intermediate state in a STIRAP transfer scheme from triplet Feshbach LiRb molecules to the $X \\ ^1\\Sigma^+$ ground state, and find that the lowest several vibrational levels possess the requisite overlap with initial and final states, as well as convenient energies. Using depletion measurements, we measured the well depth and spin-orbit splitting. We suggest possible pathways for short-range photoassociation using deeply-bound vibrational levels of this electronic state.

  8. Creating Feshbach resonances for ultracold molecule formation with radiofrequency fields

    CERN Document Server

    Owens, Daniel J; Hutson, Jeremy M

    2016-01-01

    We show that radiofrequency (RF) radiation may be used to create Feshbach resonances in ultracold gases of alkali-metal atoms at desired magnetic fields that are convenient for atomic cooling and degeneracy. For the case of $^{39}$K+$^{133}$Cs, where there are no RF-free resonances in regions where Cs may be cooled to degeneracy, we show that a resonance may be created near 21~G with 67~MHz RF radiation. This resonance is almost lossless with circularly polarized RF, and the molecules created are long-lived even with plane-polarized RF.

  9. Testing universality of Efimov physics across broad and narrow Feshbach resonances

    Science.gov (United States)

    Johansen, Jacob; Desalvo, B. J.; Patel, Krutik; Chin, Cheng

    2017-08-01

    Efimov physics is a universal phenomenon in quantum three-body systems. For systems with resonant two-body interactions, Efimov predicted an infinite series of three-body bound states with geometric scaling symmetry. These Efimov states, first observed in cold caesium atoms, have been recently reported in a variety of other atomic systems. The intriguing prospect of a universal absolute Efimov resonance position across Feshbach resonances remains an open question. Theories predict a strong dependence on the resonance strength for closed-channel-dominated Feshbach resonances, whereas experimental results have so far been consistent with the universal prediction. Here we directly compare the Efimov spectra in a 6Li-133Cs mixture near two Feshbach resonances which are very different in their resonance strengths, but otherwise almost identical. Our result shows a clear dependence of the absolute Efimov resonance position on Feshbach resonance strength and a clear departure from the universal prediction for the narrow Feshbach resonance.

  10. Quantum defect theory for the orbital Feshbach resonance

    Science.gov (United States)

    Cheng, Yanting; Zhang, Ren; Zhang, Peng

    2017-01-01

    In the ultracold gases of alkali-earth-metal-like atoms, a new type of Feshbach resonance, i.e., the orbital Feshbach resonance (OFR), has been proposed and experimentally observed in ultracold 173Yb atoms [R. Zhang et al., Phys. Rev. Lett. 115, 135301 (2015), 10.1103/PhysRevLett.115.135301]. When the OFR of the 173Yb atoms occurs, the energy gap between the open and closed channels is smaller by two orders of magnitude than the van der Waals energy. As a result, quantitative accurate results for the low-energy two-body problems can be obtained via multichannel quantum defect theory (MQDT), which is based on the exact solution of the Schrödinger equation with the van der Waals potential. In this paper we use MQDT to calculate the two-atom scattering length, effective range, and binding energy of two-body bound states for the systems with OFR. With these results we further study the clock-transition spectrum for the two-body bound states, which can be used to experimentally measure the binding energy. Our results are helpful for the quantitative theoretical and experimental research for the ultracold gases of alkali-earth-metal-like atoms with OFR.

  11. Trapped 173Yb Fermi gas across an orbital Feshbach resonance

    Science.gov (United States)

    Iskin, M.

    2017-01-01

    Starting with the two-band description of an orbital Feshbach resonance, we study superfluid properties of a trapped 173Yb Fermi gas under the assumptions of a local-density approximation for the trapping potential and a mean-field approximation for the intraband Cooper pairings. In particular, we investigate the competition and interplay between the pair-breaking effect that is caused by the interband detuning energy, and the pair-breaking and thermal-broadening effects that are simultaneously caused by the temperature. We predict several experimental signatures that are directly caused by this interplay including a spatial separation of superfluid and normal phases within the trap, and could play decisive roles in probing two-band superfluidity in these systems.

  12. Orbital order of spinless fermions near an optical Feshbach resonance

    Energy Technology Data Exchange (ETDEWEB)

    Hauke, Philipp [ICFO-Institut de Ciencies Fotoniques, Parc Mediterrani de la Tecnologia, E-08860 Castelldefels (Spain); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States); Zhao, Erhai [Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States); Department of Physics and Astronomy, George Mason University, Fairfax, Virginia 22030 (United States); Goyal, Krittika; Deutsch, Ivan H. [Center for Quantum Information and Control (CQuIC), and Department of Physics and Astronomy, University of New Mexico, Albuquerque, New Mexico 87131 (United States); Liu, W. Vincent [Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States); Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Lewenstein, Maciej [ICFO-Institut de Ciencies Fotoniques, Parc Mediterrani de la Tecnologia, E-08860 Castelldefels (Spain); Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States); ICREA-Institucio Catalana de Recerca i Estudis Avancats, Lluis Companys 23, E-08010 Barcelona (Spain)

    2011-11-15

    We study the quantum phases of a three-color Hubbard model that arises in the dynamics of the p-band orbitals of spinless fermions in an optical lattice. Strong, color-dependent interactions are induced by an optical Feshbach resonance. Starting from the microscopic scattering properties of ultracold atoms, we derive the orbital exchange constants at 1/3 filling on the cubic optical lattice. Using this, we compute the phase diagram in a Gutzwiller ansatz. We find phases with ''axial orbital order'' in which p{sub z} and p{sub x}+ip{sub y} (or p{sub x}-ip{sub y}) orbitals alternate.

  13. Controlling interactions between highly magnetic atoms with Feshbach resonances.

    Science.gov (United States)

    Kotochigova, Svetlana

    2014-09-01

    This paper reviews current experimental and theoretical progress in the study of dipolar quantum gases of ground and meta-stable atoms with a large magnetic moment. We emphasize the anisotropic nature of Feshbach resonances due to coupling to fast-rotating resonant molecular states in ultracold s-wave collisions between magnetic atoms in external magnetic fields. The dramatic differences in the distribution of resonances of magnetic (7)S3 chromium and magnetic lanthanide atoms with a submerged 4f shell and non-zero electron angular momentum is analyzed. We focus on dysprosium and erbium as important experimental advances have been recently made to cool and create quantum-degenerate gases for these atoms. Finally, we describe progress in locating resonances in collisions of meta-stable magnetic atoms in electronic P-states with ground-state atoms, where an interplay between collisional anisotropies and spin-orbit coupling exists.

  14. Controlling interactions between highly-magnetic atoms with Feshbach resonances

    CERN Document Server

    Kotochigova, Svetlana

    2014-01-01

    This paper reviews current experimental and theoretical progress in the study of dipolar quantum gases of ground and meta-stable atoms with a large magnetic moment. We emphasize the anisotropic nature of Feshbach resonances due to coupling to fast-rotating resonant molecular states in ultracold s-wave collisions between magnetic atoms in external magnetic fields. The dramatic differences in the distribution of resonances of magnetic $^7$S$_3$ chromium and magnetic lanthanide atoms with a submerged 4f shell and non-zero electron angular momentum is analyzed. We focus on Dysprosium and Erbium as important experimental advances have been recently made to cool and create quantum-degenerate gases for these atoms. Finally, we describe progress in locating resonances in collisions of meta-stable magnetic atoms in electronic P states with ground-state atoms, where an interplay between collisional anisotropies and spin-orbit coupling exists.

  15. Radiative neutron capture: Hauser Feshbach vs. statistical resonances

    Science.gov (United States)

    Rochman, D.; Goriely, S.; Koning, A. J.; Ferroukhi, H.

    2017-01-01

    The radiative neutron capture rates for isotopes of astrophysical interest are commonly calculated on the basis of the statistical Hauser Feshbach (HF) reaction model, leading to smooth and monotonically varying temperature-dependent Maxwellian-averaged cross sections (MACS). The HF approximation is known to be valid if the number of resonances in the compound system is relatively high. However, such a condition is hardly fulfilled for keV neutrons captured on light or exotic neutron-rich nuclei. For this reason, a different procedure is proposed here, based on the generation of statistical resonances. This novel technique, called the "High Fidelity Resonance" (HFR) method is shown to provide similar results as the HF approach for nuclei with a high level density but to deviate and be more realistic than HF predictions for light and neutron-rich nuclei or at relatively low sub-keV energies. The MACS derived with the HFR method are systematically compared with the traditional HF calculations for some 3300 neutron-rich nuclei and shown to give rise to significantly larger predictions with respect to the HF approach at energies of astrophysical relevance. For this reason, the HF approach should not be applied to light or neutron-rich nuclei. The Doppler broadening of the generated resonances is also studied and found to have a negligible impact on the calculated MACS.

  16. Radiative neutron capture: Hauser Feshbach vs. statistical resonances

    Directory of Open Access Journals (Sweden)

    D. Rochman

    2017-01-01

    Full Text Available The radiative neutron capture rates for isotopes of astrophysical interest are commonly calculated on the basis of the statistical Hauser Feshbach (HF reaction model, leading to smooth and monotonically varying temperature-dependent Maxwellian-averaged cross sections (MACS. The HF approximation is known to be valid if the number of resonances in the compound system is relatively high. However, such a condition is hardly fulfilled for keV neutrons captured on light or exotic neutron-rich nuclei. For this reason, a different procedure is proposed here, based on the generation of statistical resonances. This novel technique, called the “High Fidelity Resonance” (HFR method is shown to provide similar results as the HF approach for nuclei with a high level density but to deviate and be more realistic than HF predictions for light and neutron-rich nuclei or at relatively low sub-keV energies. The MACS derived with the HFR method are systematically compared with the traditional HF calculations for some 3300 neutron-rich nuclei and shown to give rise to significantly larger predictions with respect to the HF approach at energies of astrophysical relevance. For this reason, the HF approach should not be applied to light or neutron-rich nuclei. The Doppler broadening of the generated resonances is also studied and found to have a negligible impact on the calculated MACS.

  17. Influence of external magnetic and laser radiation fields on Feshbach resonances in collision of atoms

    CERN Document Server

    Gazazyan, E A; Chaltykyan, V O

    2012-01-01

    We study collision of two atoms with formation of Feshbach resonance at combined interaction with the external magnetic field and laser radiation. In cases of one- and two-photon resonances of laser radiation with two discrete vibrational molecular levels, we show that Feshbach resonances appear at interaction of external magnetic field with dressed states formed via Autler-Townes effect. In addition, in case of one-photon resonance the lower vibrational molecular state is coupled by laser radiation with the continuum of the elastic channel and forms laser-induced Feshbach resonance via both Autler-Townes effect and LICS mechanism. We study the combined process of formation of Feshbach resonances; this enables the control of Feshbach resonance by varying the magnetic field and intensity and frequency of laser radiation. We obtain the cross-sections of elastic and inelastic scattering and show that quenching of resonance occurs at the energy equal to that of the systems ground state. Dependence of the cross-se...

  18. Magnetic Feshbach resonances in collisions of closed-shell $^1\\Sigma$ molecules

    CERN Document Server

    Wallis, Alisdair O G

    2012-01-01

    Magnetic Feshbach resonances play a central role in experimental research of atomic gases at ultracold temperatures. A major thrust of current research is to create an ultracold gas of diatomic alkali-metal molecules in the ground rovibrational state of the ground electronic $^1\\Sigma$ state. Can ultracold $^1\\Sigma$ molecules be controlled by means of magnetic Feshbach resonances? Unlike alkali metal atoms, $^1\\Sigma$ diatomic molecules have no unpaired electrons. The response of $^1\\Sigma$ molecules to an external magnetic field is determined by the spin structure of the atomic nuclei. We present quantum scattering calculations illustrating that nuclear spin relaxation and Feshbach resonances in ultracold molecule-molecule collisions for $^1\\Sigma$ molecules in a magnetic field are highly probable. We show that certain Zeeman states of $^1\\Sigma$ molecules exhibit broad resonances and weak inelastic scattering, which makes these states ideal for experiments exploiting magnetic field control of ultracold mol...

  19. Sweeping a molecular Bose-Einstein condensate across a Feshbach resonance

    NARCIS (Netherlands)

    Haque, M.; Stoof, H.T.C.

    2007-01-01

    We consider the dissociation of a molecular Bose-Einstein condensate during a magnetic-field sweep through a Feshbach resonance that starts on the molecular side of the resonance and ends on the atomic side. In particular, we determine the energy distribution of the atoms produced after the sweep. W

  20. Statistical mechanics of a Feshbach-coupled Bose-Fermi gas in an optical lattice

    DEFF Research Database (Denmark)

    Sørensen, Ole Søe; Nygaard, Nicolai; Blakie, P.B.

    2009-01-01

    We consider an atomic Fermi gas confined in a uniform optical lattice potential, where the atoms can pair into molecules via a magnetic-field-controlled narrow Feshbach resonance. The phase diagram of the resulting atom-molecule mixture in chemical and thermal equilibria is determined numerically...

  1. Microscopic Many-Body Theory of Atomic Bose Gases near a Feshbach Resonance

    NARCIS (Netherlands)

    Duine, R.A.; Stoof, H.T.C.

    2003-01-01

    A Feshbach resonance in the s-wave scattering length occurs if the energy of the two atoms in the incoming open channel is close to the energy of a bound state in a coupled closed channel. Starting from the microscopic Hamiltonian that describes this situation, we derive the effective atom–molecule

  2. A two-channel R-matrix analysis of magnetic field induced Feshbach resonances

    DEFF Research Database (Denmark)

    Nygaard, Nicolai; Schneider, B. I.; Julienne, P. S.

    2006-01-01

    such an effective Feshbach model can be constructed from knowledge of a few key parameters, characterizing the atomic Born-Oppenheimer potentials and the low energy scattering near the resonance. These parameters may be obtained either from experiment or full coupled channels calculations. Using R-matrix theory we...

  3. Reaching a Fermi-superfluid state near an orbital Feshbach resonance

    Science.gov (United States)

    Xu, Junjun; Zhang, Ren; Cheng, Yanting; Zhang, Peng; Qi, Ran; Zhai, Hui

    2016-09-01

    We propose to realize a strongly interacting Fermi superfluid near a narrow Feshbach resonance using the recently discovered "orbital Feshbach resonance." The orbital Feshbach resonance is a type of magnetic field tunable scattering resonance theoretically predicted and experimentally observed recently in the alkaline-earth-metal-like 173Yb atom. We first show that the orbital Feshbach resonance is a narrow resonance in energy, while it is hundreds Gauss wide in terms of magnetic field strength, taking the advantage that the magnetic moment difference between the open and closed channels is quite small. Therefore, this is an ideal platform for the experimental realization of a strongly interacting Fermi superfluid with narrow resonance. We further show that the transition temperature for the Fermi superfluid in this system, especially at the BCS side of the resonance, is even higher than that in a wide resonance, which is also due to the narrow character of this resonance. Our results will encourage experimental efforts to realize Fermi superfluid in the alikaline-earth-metal-like 173Yb system, the properties of which will be complementary to extensively studied Fermi superfluids nearby a wide resonance in alkali-metal 40K and 6Li systems.

  4. Precision spectroscopy with ultracold {sup 87}Rb{sub 2} triplet molecules

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, Christoph

    2011-10-19

    In this thesis I report precision spectroscopy with ultracold {sup 87}Rb{sub 2} triplet molecules where we use lasers to couple the states in different molecular potentials. We study in detail states of the a {sup 3} sum {sup +}{sub u} and (1) {sup 3} sum {sup +}{sub g} potentials. These states are of great importance for transferring weakly bound molecules to the ro-vibrational triplet ground state via states of the excited potential. As most experiments start from molecules in their X {sup 1} sum {sup +}{sub g} ground state, the triplet states were hard to access via dipole transitions and remained largely unexplored. The measurements presented in this thesis are the first detailed study of diatomic {sup 87}Rb{sub 2} molecules in these states. Our experiments start with an ultracold cloud of {sup 87}Rb atoms. We then load this cloud into an optical lattice where we use a magnetic Feshbach resonance at 1007.4 G to perform a Feshbach association. After we have removed all unbound atoms, we end up with a pure sample of weakly bound Feshbach molecules inside the optical lattice. The optical lattice prevents these molecules from colliding with each other which results in molecular lifetimes on the order of a few hundred milliseconds. In the first set of experiments, we use a laser coupling the Feshbach state to the excited (1) {sup 3} sum {sup +}{sub g} triplet state to map out its low-lying vibrational (v = 0.. 15), rotational, hyperfine, and Zeeman structure. The experimental results are in good agreement with calculations done by Marius Lysebo and Prof. Leif Veseth. We then map out in detail the vibrational, rotational, hyperfine, and Zeeman structure of the a {sup 3} sum {sup +}{sub u} triplet ground state using dark state spectroscopy with levels in the (1) {sup 3} sum {sup +}{sub g} potential as an intermediate state. In this scheme we are able to access molecules in triplet states because our Feshbach state has strong triplet character. Interestingly, it

  5. Creation of p-wave Feshbach molecules in the selected angular momentum states using an optical lattice

    CERN Document Server

    Waseem, Muhammad; Yoshida, Jun; Hattori, Keita; Saito, Taketo; Mukaiyama, Takashi

    2016-01-01

    We selectively create p-wave Feshbach molecules in the $m_{l}=\\pm 1$ orbital angular momentum projection state of $^{6}$Li. We use an optical lattice potential to restrict the relative momentum of the atoms such that only the $m_{l}=\\pm 1$ molecular state couples to the atoms at the Feshbach resonance. We observe the hollow-centered dissociation profile, which is a clear indication of the selective creation of p-wave molecules in the $m_{l}=\\pm1$ states. We also measure the dissociation energy of the p-wave molecules created in the optical lattice and develop a theoretical formulation to explain the dissociation energy as a function of the magnetic field ramp rate for dissociation. The capability of selecting one of the two closely-residing p-wave Feshbach resonances is useful for the precise characterization of the p-wave Feshbach resonances.

  6. Matrix continued fraction approach to the relativistic quantum mechanical spin-zero Feshbach-Villars equations

    Science.gov (United States)

    Brown, Natalie

    In this thesis we solve the Feshbach-Villars equations for spin-zero particles through use of matrix continued fractions. The Feshbach-Villars equations are derived from the Klein-Gordon equation and admit, for the Coulomb potential on an appropriate basis, a Hamiltonian form that has infinite symmetric band-matrix structure. The corresponding representation of the Green's operator of such a matrix can be given as a matrix continued fraction. Furthermore, we propose a finite dimensional representation for the potential operator such that it retains some information about the whole Hilbert space. Combining these two techniques, we are able to solve relativistic quantum mechanical problems of a spin-zero particle in a Coulomb-like potential with a high level of accuracy.

  7. Single and double charge transfer in Be/sup 4+/+He collisions: A molecular (Feshbach) approach

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.; Riera, A.; Yaez, M.

    1986-12-01

    In recent articles, we pointed out the fundamental difference between the molecular treatment of processes involving a multicharged ion and hydrogen or helium atoms, which is the (formal) autoionizing character of the molecular channels, and we reported a (new) implementation of the Feshbach method to calculate the molecular energies and couplings. In the present work we use the wave functions calculated with this Feshbach method for the BeHe/sup 4+/ quasimolecule, introduce a common translation factor in the formalism, and calculate the single and double charge-exchange cross sections in Be/sup 4+/+He(1s/sup 2/) collisions for impact energies 0.2--20 keV/amu. The mechanisms of the processes are discussed in detail.

  8. Testing universality of Efimov physics across broad and narrow Feshbach resonances

    OpenAIRE

    Johansen, Jacob; DeSalvo, B. J.; Patel, Krutik; Chin, Cheng

    2016-01-01

    Efimov physics is a universal phenomenon arising in quantum three-body systems. For systems with resonant two-body interactions, Efimov predicted an infinite series of three-body bound states with geometric scaling symmetry. These Efimov states were first observed in cold Cs atoms and have since been reported in a variety of atomic systems. While theories predict non-universal behavior for narrow Feshbach resonances, experiments on Efimov resonances are so far consistent with predictions base...

  9. Orbital Feshbach resonances with a small energy gap between open and closed channels

    Science.gov (United States)

    Cheng, Yanting; Zhang, Ren; Zhang, Peng

    2016-04-01

    Recently, a new type of Feshbach resonance, i.e., orbital Feshbach resonance (OFR), was proposed for the ultracold alkaline-earth-metal-like atoms and was experimentally observed in the ultracold gases of 173Yb atoms. Unlike most of the magnetic Feshbach resonances of ultracold alkali atoms, when the OFR of 173Yb atoms appears, the energy gap between the thresholds of the open channel (OC) and the closed channel (CC) is much smaller than the characteristic energy of the interatomic interaction, i.e., the van der Waals energy. In this paper we study the OFR in systems with a small CC-OC threshold gap. We show that in these systems the OFR can be induced by the coupling between the OC and either an isolated bound state of the CC or the scattering states of the CC. Moreover, we also show that in each case the two-channel Huang-Yang pesudopotential is always applicable for the approximate calculation of the low-energy scattering amplitude. Our results imply that in the two-channel theoretical calculations for these systems it is appropriate to take into account the contributions from the scattering states of the CC.

  10. RB: Programmer Specification of Redundancy

    OpenAIRE

    Smith, Jonathan M.; Gerald Q. Maguire Jr.

    1987-01-01

    RB is a programming language for specifying redundancy in various dimensions. Avizienis's notation T I HIS, for Time I Hardware I Software, describes the different types of redundancy possible in a computation: repetition (nT I HIS), redundant hardware (T I nH I S), and program (software) (T I H InS). These can each be controlled by the programmer with RB. RB derives its name from its use of the recovery block notion to specify fault-tolerant segments of software. RB also supplies the program...

  11. Genetic Predisposition to Retinoblastoma (Rb)

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    Determination of 8 cytogenetic indicators in 14 cases of Rb,their 21 parents and 14 normal controls revealed various degrees ofchromosome instability and nondisjunction in the patients and their parents,indicating the presence of genetic neoplastic predisposition to neoplasm inRb patients.Eye Science 1993;9:149-152.

  12. Inelastic collisions of ultracold triplet Rb$_\\textbf{2}$ molecules in the rovibrational ground state

    CERN Document Server

    Drews, Björn; Jachymski, Krzysztof; Idziaszek, Zbigniew; Denschlag, Johannes Hecker

    2016-01-01

    Exploring inelastic and reactive collisions on the quantum level is a main goal of the developing field of ultracold chemistry. We present first experimental studies of inelastic collisions of metastable ultracold triplet molecules in the vibrational ground state. The measurements are performed with nonpolar Rb$_2$ dimers which are prepared in precisely-defined quantum states and trapped in an array of quasi-1D potential tubes. We investigate collisions of molecules in the lowest triplet energy level where any inelastic process requires a relaxation to the singlet state. These are compared to two sets of collision experiments, carried out either with triplet molecules that have two quanta of rotational angular momentum or with vibrationally highly excited Feshbach molecules. We find no evidence for suppression of the inelastic collisions due to the necessary spin-flip, shedding light on this so far unsettled issue. For each of the molecular states studied here, we extract the decay rate constant and compare t...

  13. Test of the universality of the three-body Efimov parameter at narrow Feshbach resonances.

    Science.gov (United States)

    Roy, Sanjukta; Landini, Manuele; Trenkwalder, Andreas; Semeghini, Giulia; Spagnolli, Giacomo; Simoni, Andrea; Fattori, Marco; Inguscio, Massimo; Modugno, Giovanni

    2013-08-02

    We measure the critical scattering length for the appearance of the first three-body bound state, or Efimov three-body parameter, at seven different Feshbach resonances in ultracold ^{39}K atoms. We study both intermediate and narrow resonances, where the three-body spectrum is expected to be determined by the nonuniversal coupling of two scattering channels. Instead, our observed ratio of the three-body parameter with the van der Waals radius is approximately the same universal ratio as for broader resonances. This unexpected observation suggests the presence of a new regime for three-body scattering at narrow resonances.

  14. Efimov Trimers near the Zero-crossing of a Feshbach Resonance

    DEFF Research Database (Denmark)

    Zinner, Nikolaj Thomas

    2012-01-01

    Near a Feshbach resonance, the two-body scattering length can assume any value. When it approaches zero, the next-order term given by the effective range is known to diverge. We consider the question of whether this divergence (and the vanishing of the scattering length) is accompanied by an anom...... by an anomalous solution of the three-boson Schr\\"odinger equation similar to the one found at infinite scattering length by Efimov. Within a simple zero-range model, we find no such solutions, and conclude that higher-order terms do not support Efimov physics....

  15. Feshbach shape resonance for high Tc pairing in superlattices of quantum stripes and quantum wells

    Directory of Open Access Journals (Sweden)

    A Bianconi

    2006-09-01

    Full Text Available   The Feshbach shape resonances in the interband pairing in superconducting superlattices of quantum wells or quantum stripes is shown to provide the mechanism for high Tc superconductivity. This mechanism provides the Tc amplification driven by the architecture of material: superlattices of quantum wells (intercalated graphite or diborides and superlattices of quantum stripes (doped high Tc cuprate perovskites where the chemical potential is tuned to a Van Hove-Lifshitz singularity (vHs in the electronic energy spectrum of the superlattice associated with the change of the Fermi surface dimensionality in one of the subbands.

  16. Dynamics of Feshbach Molecules in an Ultracold Three-Component Mixture

    CERN Document Server

    Khramov, A Y; Jamison, A O; Dowd, W H; Gupta, S

    2012-01-01

    We present investigations of the formation rate and collisional stability of lithium Feshbach molecules in an ultracold three-component mixture composed of two resonantly interacting fermionic 6-Li spin states and bosonic 174-Yb. We observe long molecule lifetimes (> 100 ms) even in the presence of a large ytterbium bath and extract reaction rate coefficients of the system. We find good collisional stability of the mixture in the unitary regime, opening new possibilities for studies and probes of strongly interacting quantum gases in contact with a bath species.

  17. Monte-Carlo Hauser-Feshbach simulations of prompt fission gamma-ray properties

    Science.gov (United States)

    Stetcu, Ionel; Talou, Patrick; Kawano, Toshihiko; Jandel, Marian

    2014-09-01

    Properties of prompt fission neutrons and γ rays, emitted before the weak decays of the fission fragments toward stability, are important for both nuclear technologies and a better understanding of the fission process. In the present work, we use the Hauser-Feshbach model to simulate the de-excitation of the fully accelerated fission fragments treated as compound nuclei. Our Monte-Carlo implementation of the Hauser-Feshbach statistical model, which takes into account the competition between the neutron and γ emissions, allows the description of both average quantities, like in the Los Alamos model, and correlations between the emitted particles. Our simulations will be compared against available experimental data and current evaluations. In particular, we will compare our average γ-ray spectrum with recent measurements at the research reactor KFKI in Budapest for the 235U(nth , f) and 252Cf(sf) reactions, as well as multiplicity-dependent distributions obtained at the DANCE facility at LANSCE. Properties of prompt fission neutrons and γ rays, emitted before the weak decays of the fission fragments toward stability, are important for both nuclear technologies and a better understanding of the fission process. In the present work, we use the Hauser-Feshbach model to simulate the de-excitation of the fully accelerated fission fragments treated as compound nuclei. Our Monte-Carlo implementation of the Hauser-Feshbach statistical model, which takes into account the competition between the neutron and γ emissions, allows the description of both average quantities, like in the Los Alamos model, and correlations between the emitted particles. Our simulations will be compared against available experimental data and current evaluations. In particular, we will compare our average γ-ray spectrum with recent measurements at the research reactor KFKI in Budapest for the 235U(nth , f) and 252Cf(sf) reactions, as well as multiplicity-dependent distributions obtained at the

  18. Feshbach-enhancement of Raman photoassociation in a Bose-Einstein condensate

    CERN Document Server

    Mackie, Matt; Boyce, Heather; Shinn, Mannix; Katz, Lev

    2011-01-01

    We model the formation of stable heteronuclear molecules via pulsed Raman photoassociation of a two-component Bose-Einstein condensate near a strong Feshbach resonance, for both counterintuitive and intuitive pulse sequencing. Compared to lasers alone, weak Raman photoassociation is enhanced by as much as a factor of ten (five) for a counterintuitive (intuitive) pulse sequence, whereas strong Raman photoassociation is barely enhanced at all--regardless of pulse sequence. Stronger intra-atom, molecule, or atom-molecule collisions lead to an expected decrease in conversion efficiency, but stronger ambient inter-atom collisions lead to an unexpected increase in the efficiency of stable molecule production.

  19. Chaotic scattering in the presence of a dense set of overlapping Feshbach resonances

    CERN Document Server

    Jachymski, Krzysztof

    2015-01-01

    Complex quantum systems consisting of large numbers of strongly coupled states exhibit characteristic correlations in the level spacing distribution which can be described by Random Matrix Theory. Scattering resonances observed in ultracold atomic and molecular systems exhibit similar features as a consequence of their energy level structure. We study how the overlap between Feshbach resonances affects the distribution of resonance spacings. We find that the level repulsion between resonances leads to correlations that resemble the results known for quantum chaotic systems even when the assumptions of Random Matrix Theory are not fulfilled.

  20. Creating Feshbach resonances for ultracold molecule formation with radio-frequency fields

    Science.gov (United States)

    Owens, Daniel J.; Xie, Ting; Hutson, Jeremy M.

    2016-08-01

    We show that radio-frequency (rf) radiation may be used to create Feshbach resonances in ultracold gases of alkali-metal atoms at desired magnetic fields that are convenient for atomic cooling and degeneracy. For the case of 39K+133Cs , where there are no rf-free resonances in regions where Cs may be cooled to degeneracy, we show that a resonance may be created near 21 G with 69.2 MHz rf radiation. This resonance is almost lossless with circularly polarized rf, and the molecules created are long-lived even with plane-polarized rf.

  1. Calculation of delayed-neutron energy spectra in a QRPA-Hauser-Feshbach model

    Energy Technology Data Exchange (ETDEWEB)

    Kawano, Toshihiko [Los Alamos National Laboratory; Moller, Peter [Los Alamos National Laboratory; Wilson, William B [Los Alamos National Laboratory

    2008-01-01

    Theoretical {beta}-delayed-neutron spectra are calculated based on the Quasiparticle Random-Phase Approximation (QRPA) and the Hauser-Feshbach statistical model. Neutron emissions from an excited daughter nucleus after {beta} decay to the granddaughter residual are more accurately calculated than in previous evaluations, including all the microscopic nuclear structure information, such as a Gamow-Teller strength distribution and discrete states in the granddaughter. The calculated delayed-neutron spectra agree reasonably well with those evaluations in the ENDF decay library, which are based on experimental data. The model was adopted to generate the delayed-neutron spectra for all 271 precursors.

  2. RB975242 and RB975201 - Late maturation sugarcane varieties

    Directory of Open Access Journals (Sweden)

    Monalisa Sampaio Carneiro

    2016-11-01

    Full Text Available The sugarcane varieties RB975201 and RB975242 were developed and released for harvest at the end of the season (late maturation in the CentralSouth region of Brazil. In specific environments, these varieties were compared with commercial standards in sugar yield per area. They are resistant to major sugarcane diseases and present the Bru1 gene of resistance to brown rust.

  3. A high phase-space density mixture of $^{87}$Rb and $^{133}$Cs: towards ultracold heteronuclear molecules

    CERN Document Server

    Cho, H W; Jenkin, D L; Köppinger, M P; Cornish, S L; 10.1140/epjd/e2011-10716-1

    2011-01-01

    We report the production of a high phase-space density mixture of $^{87}$Rb and $^{133}$Cs atoms in a levitated crossed optical dipole trap as the first step towards the creation of ultracold RbCs molecules via magneto-association. We present a simple and robust experimental setup designed for the sympathetic cooling of $^{133}$Cs via interspecies elastic collisions with $^{87}$Rb. Working with the $|F=1, m_F=+1 >$ and the $|3, +3 >$ states of $^{87}$Rb and $^{133}$Cs respectively, we measure a high interspecies three-body inelastic collision rate $\\sim 10^{-25}-10^{-26} \\rm{cm}^{6}\\rm{s}^{-1}$ which hinders the sympathetic cooling. Nevertheless by careful tailoring of the evaporation we can produce phase-space densities near quantum degeneracy for both species simultaneously. In addition we report the observation of an interspecies Feshbach resonance at 181.7(5) G and demonstrate the creation of Cs$_{2}$ molecules via magneto-association on the 4g(4) resonance at 19.8 G. These results represent important ste...

  4. Interspecies Feshbach resonances in an ultracold, optically trapped Bose-Fermi mixture of cesium and lithium

    Energy Technology Data Exchange (ETDEWEB)

    Repp, Marc

    2013-05-08

    This thesis reports on the tunability of interactions in ultracold Bose-Fermi mixtures of Cesium and Lithium. The first realization of an optically trapped {sup 6}Li - {sup 133}Cs mixture enabled to perform trap loss spectroscopy measurements to identify magnetic Feshbach resonances. A total of 19 interspecies Feshbach resonances, all in the magnetic field range between 650 G and 950 G, were observed for the two energetically lowest spin states of each species. Two 5 G broad and especially two 60 G broad s-wave resonances give perspectives to produce a dipolar quantum gas of LiCs ground state molecules as well as to study the Efimov effect in highly mass imbalanced systems. In addition, a unique relative tunability of intra- and interspecies scattering lengths was found which makes the {sup 6}Li - {sup 133}Cs system also well suited for the investigation of polarons. Evaporative cooling was performed on optically trapped samples which contained only one of the species. In this way, Bose-Einstein condensates of {sup 6}Li molecules as well as {sup 133}Cs samples at a phase-space density of ρ = 4 . 10{sup -2} were prepared. All experiments were performed in a new apparatus, which has been designed and set up during this thesis.

  5. Feshbach P -Q partitioning technique and the two-component Dirac equation

    Science.gov (United States)

    Luo, Da-Wei; Pyshkin, P. V.; Yu, Ting; Lin, Hai-Qing; You, J. Q.; Wu, Lian-Ao

    2016-09-01

    We provide an alternative approach to relativistic dynamics based on the Feshbach projection technique. Instead of directly studying the Dirac equation, we derive a two-component equation for the upper spinor. This approach allows one to investigate the underlying physics in a different perspective. For particles with small mass such as the neutrino, the leading-order equation has a Hermitian effective Hamiltonian, implying there is no leakage between the upper and lower spinors. In the weak relativistic regime, the leading order corresponds to a non-Hermitian correction to the Pauli equation, which takes into account the nonzero possibility of finding the lower-spinor state and offers a more precise description.

  6. Stabilizations of Two-Dimensional Trapped and Untrapped Matter Waves via a Feshbach Resonance Technique

    Institute of Scientific and Technical Information of China (English)

    LUO Xiao-Bing; HAI Wen-Hua

    2005-01-01

    @@ We have studied the dynamics of two-dimensional (2D) trapped and untrapped Bose-Einstein condensates (BECs) with a rapid periodic modulation of the scattering length via a Feshbach resonance technique, a → ao + a1 sin(Ωt) with an attractive (negative) mean value and the large constants ao, a1 and Ω.Applying a variation approximation (VA), the critical threshold for the collapse of the 2D trapped vortex BEC is predicted and the collapse is prevented by causing the scattering length oscillating rapidly.On the other hand, with analytical calculation, we prove that the stabilization of a bright soliton in a 2D untrapped BEC is impossible for enough large interaction intensity and the upper limit of the intensity for the soliton stabilization is derived.

  7. A study of Feshbach resonances and the unitary limit in a model of strongly correlated nucleons

    CERN Document Server

    Mekjian, Aram Z

    2010-01-01

    A model of strongly interacting and correlated hadrons is developed. The interaction used contains a long range attraction and short range repulsive hard core. Using this interaction and various limiting situations of it, a study of the effect of bound states and Feshbach resonances is given. The limiting situations are a pure square well interaction, a delta-shell potential and a pure hard core potential. The limit of a pure hard core potential are compared with results for a spinless Bose and Fermi gas. The limit of many partial waves for a pure hard core interaction is also considered and result in expressions involving the hard core volume. This feature arises from a scaling relation similar to that for hard sphere scattering with diffractive corrections. The role of underlying isospin symmetries associated with the strong interaction of protons and neutrons in this two component model is investigated. Properties are studied with varying proton fraction. An analytic expression for the Beth Uhlenbeck conti...

  8. Inner-shell photodetachment from N i- : A giant Feshbach resonance

    Science.gov (United States)

    Dumitriu, I.; Bilodeau, R. C.; Gorczyca, T. W.; Walter, C. W.; Gibson, N. D.; Rolles, D.; Pešić, Z. D.; Aguilar, A.; Berrah, N.

    2017-08-01

    Inner-shell photodetachment from N i-([Ar ] 3 d94 s2) leading to N i+,N i2 + , and N i3 + ion production was studied near and above the 3 p excitation region, in the 60-90 eV photon energy range, using a merged ion-photon beam technique. The absolute photodetachment cross section of N i- leading to N i+ ion production was measured. The 3 p →3 d photoexcitation in N i- gives rise to a giant Feshbach resonance. In the near-threshold region, a Fano profile, modified by a Wigner s -wave (l =0 ) threshold law, accurately fits the N i- single-photodetachment cross section. A lower-order R -matrix calculation shows overall agreement with essential features of the experimental data, confirming the nature of the strong, asymmetric Fano profile of the giant 3 p →3 d photoexcitation-autodetachment resonance in N i- .

  9. Direct observation of Feshbach enhanced $\\it{s}$-wave scattering of fermions

    CERN Document Server

    Genkina, Dina; Stuhl, Benjamin K; Lu, Hsin-I; Spielman, Ian

    2015-01-01

    We directly measured the normalized $\\it{s}$-wave scattering cross-section of ultracold $^{40}\\rm{K}$ atoms across a magnetic-field Feshbach resonance by colliding pairs of degenerate Fermi gases (DFGs) and imaging the scattered atoms. We extracted the scattered fraction for a range of bias magnetic fields, and measured the resonance location to be $B_0 = 20.206(15)$ mT with width $\\Delta = 1.0(5)$ mT. To optimize the signal-to-noise ratio of atom number in scattering images, we developed techniques to interpret absorption images in a regime where recoil induced detuning corrections are significant. These imaging techniques are generally applicable to experiments with lighter alkalis that would benefit from maximizing signal-to-noise ratio on atom number counting at the expense of spatial imaging resolution.

  10. Molecular (Feshbach) treatment of charge exchange Li/sup 3 +/+He collisions. I. Energies and couplings

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.; Riera, A.; Yanez, M.

    1986-05-15

    We point out a fundamental difference between the molecular treatment of charge exchange X/sup n/++H(1s) and X/sup n/++He(1s/sup 2/) collisions, which is that the latter process involves molecular states that are formally autoionizing. Then standard ab initio methods do not, in general, yield the relevant wave functions that are needed in the collision treatment, irrespective of whether quasimolecular autoionization be significant or not during the collision. We implement a particularly simple and useful form of the Feshbach formalism to calculate the energies of those two electron systems, and a method to evaluate the corresponding dynamical couplings is presented for the first time. Our implementation of this formalism together with the new computational techniques involved are presented in detail.

  11. Tunneling Dynamics of Two-Species Bose-Einstein Condensates with Feshbach Resonances

    Institute of Scientific and Technical Information of China (English)

    CHENChanu-Yonu

    2003-01-01

    We investigate tunneling dynamics of atomic group consisting of three atoms in Bose-Einstein condensates with Feshbach resonance. It is shown that the tunneling of the atom group depends not only on the inter-atomic nonlinear interactions and the initial number of atoms in these condensates, but also on the tunneling coupling between the atomic condensate and the three-atomic molecular condensate. It is found that besides oscillating tunneling current between the atomic condensate and the molecular condensate, the nonlinear atomic group tunneling dynamics sustains a self-maintained population imbalance: a macroscopic quantum self-trapping effect. The influence of de-coherence caused by non-condensate atoms on the tunneling dynamics is studied. It is indicated that de-coherence suppresses the atomic group tunneling.

  12. Tunneling Dynamics of Two-Species Bose-Einstein Condensates with Feshbach Resonances

    Institute of Scientific and Technical Information of China (English)

    CHEN Chang-Yong

    2003-01-01

    We investigate tunneling dynamics of atomic group consisting of three atoms in Bose-Einstein condensateswith Feshbach resonance. It is shown that the tunneling of the atom group depends not only on the inter-atomicnonlinear interactions and the initial number of atoms in these condensates, but also on the tunneling coupling betweenthe atomic condensate and the three-atomic molecular condensate. It is found that besides oscillating tunneling currentbetween the atomic condensate and the molecular condensate, the nonlinear atomic group tunneling dynamics sustains aself-maintained population imbalance: a macroscopic quantum self-trapping effect. The influence of de-coherence causedby non-condensate atoms on the tunneling dynamics is studied. It is indicated that de-coherence suppresses the atomicgroup tunneling.

  13. Measurement of the binding energy of ultracold $^{87}$Rb$^{133}$Cs molecules using an offset-free optical frequency comb

    CERN Document Server

    Molony, Peter K; Gregory, Philip D; Kliese, Russell; Puppe, Thomas; Sueur, C Ruth Le; Aldegunde, Jesus; Hutson, Jeremy M; Cornish, Simon L

    2016-01-01

    We report the binding energy of $^{87}$Rb$^{133}$Cs molecules in their rovibrational ground state measured using an offset-free optical frequency comb based on difference frequency generation technology. We create molecules in the absolute ground state using stimulated Raman adiabatic passage (STIRAP) with a transfer efficiency of 88\\%. By measuring the absolute frequencies of our STIRAP lasers, we find the energy-level difference from an initial weakly-bound Feshbach state to the rovibrational ground state with a resolution of 5 kHz over an energy-level difference of more than 114 THz; this lets us discern the hyperfine splitting of the ground state. Combined with theoretical models of the Feshbach state binding energies and ground-state hyperfine structure, we determine a zero-field binding energy of $h\\times114\\,268\\,135\\,237(5)(50)$ kHz. To our knowledge, this is the most accurate determination to date of the dissociation energy of a molecule.

  14. Measurement of the binding energy of ultracold 87Rb133Cs molecules using an offset-free optical frequency comb

    Science.gov (United States)

    Molony, Peter K.; Kumar, Avinash; Gregory, Philip D.; Kliese, Russell; Puppe, Thomas; Le Sueur, C. Ruth; Aldegunde, Jesus; Hutson, Jeremy M.; Cornish, Simon L.

    2016-08-01

    We report the binding energy of 87Rb133Cs molecules in their rovibrational ground state measured using an offset-free optical frequency comb based on difference frequency generation technology. We create molecules in the absolute ground state using stimulated Raman adiabatic passage (STIRAP) with a transfer efficiency of 88%. By measuring the absolute frequencies of our STIRAP lasers, we find the energy-level difference from an initial weakly bound Feshbach state to the rovibrational ground state with a resolution of ˜5 kHz over an energy-level difference of more than 114 T Hz ; this lets us discern the hyperfine splitting of the ground state. Combined with theoretical models of the Feshbach-state binding energies and ground-state hyperfine structure, we determine a zero-field binding energy of h ×114 268 135.24 (4 )(3 )M Hz . To our knowledge, this is the most accurate determination to date of the dissociation energy of a molecule.

  15. RB1 in cancer: different mechanisms of RB1 inactivation and alterations of pRb pathway in tumorigenesis.

    Science.gov (United States)

    Di Fiore, Riccardo; D'Anneo, Antonella; Tesoriere, Giovanni; Vento, Renza

    2013-08-01

    Loss of RB1 gene is considered either a causal or an accelerating event in retinoblastoma. A variety of mechanisms inactivates RB1 gene, including intragenic mutations, loss of expression by methylation and chromosomal deletions, with effects which are species-and cell type-specific. RB1 deletion can even lead to aneuploidy thus greatly increasing cancer risk. The RB1gene is part of a larger gene family that includes RBL1 and RBL2, each of the three encoding structurally related proteins indicated as pRb, p107, and p130, respectively. The great interest in these genes and proteins springs from their ability to slow down neoplastic growth. pRb can associate with various proteins by which it can regulate a great number of cellular activities. In particular, its association with the E2F transcription factor family allows the control of the main pRb functions, while the loss of these interactions greatly enhances cancer development. As RB1 gene, also pRb can be functionally inactivated through disparate mechanisms which are often tissue specific and dependent on the scenario of the involved tumor suppressors and oncogenes. The critical role of the context is complicated by the different functions played by the RB proteins and the E2F family members. In this review, we want to emphasize the importance of the mechanisms of RB1/pRb inactivation in inducing cancer cell development. The review is divided in three chapters describing in succession the mechanisms of RB1 inactivation in cancer cells, the alterations of pRb pathway in tumorigenesis and the RB protein and E2F family in cancer.

  16. Magnetic control of ultra-cold $^6$Li and $^{174}$Yb($^3P_2$) atom mixtures with Feshbach resonances

    CERN Document Server

    Petrov, Alexander; Kotochigova, Svetlana

    2015-01-01

    We theoretically evaluate the feasibility to form magnetically-tunable Feshbach molecules in collisions between fermionic $^6$Li atoms and bosonic metastable $^{174}$Yb($^3$P$_2$) atoms. In contrast to the well-studied alkali-metal atom collisions, collisions with meta-stable atoms are highly anisotropic. Our first-principle coupled-channel calculation of these collisions reveals the existence of broad Feshbach resonances due to the combined effect of anisotropic-molecular and atomic-hyperfine interactions. In order to fit our predictions to the specific positions of experimentally-observed broad resonance structures \\cite{Deep2015} we optimized the shape of the short-range potentials by direct least-square fitting. This allowed us to identify the dominant resonance by its leading angular momentum quantum numbers and describe the role of collisional anisotropy in the creation and broadening of this and other resonances.

  17. Statistical Hauser-Feshbach theory with width fluctuation correction including direct reaction channels for neutron induced reaction at low energies

    CERN Document Server

    Kawano, T; Hilaire, S

    2016-01-01

    A model to calculate particle-induced reaction cross sections with statistical Hauser-Feshbach theory including direct reactions is given. The energy average of scattering matrix from the coupled-channels optical model is diagonalized by the transformation proposed by Engelbrecht and Weidenm\\"{u}ller. The ensemble average of $S$-matrix elements in the diagonalized channel space is approximated by a model of Moldauer [Phys.Rev.C {\\bf 12}, 744 (1975)] using newly parametrized channel degree-of-freedom $\

  18. RbYb(PO34

    Directory of Open Access Journals (Sweden)

    Hui Chen

    2013-01-01

    Full Text Available Rubidium ytterbium(III tetrakis(polyphosphate, RbYb(PO34, was synthesized by solid-state reaction. It adopts structure type IV of the MRE(PO34 (M = alkali metal and RE = rare earth metal family of compounds. The structure is composed of a three-dimensional framework made up from double spiral polyphosphate chains parallel to [10-1] and irregular [YbO8] polyhedra. There are eight PO4 tetrahedra in the repeat unit of the polyphosphate chains. The Rb+ cation is located in channels extending along [100] that are delimited by the three-dimensional framework. It is surrounded by 11 O atoms, defining an irregular polyhedron.

  19. Ultracold hydrogen and deuterium production via Doppler-cooled Feshbach molecules

    CERN Document Server

    Lane, Ian

    2013-01-01

    A counterintuitive scheme to produce ultracold hydrogen via fragmentation of laser cooled diatomic hydrides is presented where the final atomic H temperature is inversely proportional to the mass of the molecular parent. In addition, the critical density for formation of a Bose-Einstein Condensate (BEC) at a fixed temperature is reduced by a factor ratio hydrogen mass: parent mass raised to power 3/2 over directly cooled hydrogen atoms. The narrow Feshbach resonances between a singlet S atom and hydrogen are well suited to a tiny center of mass energy release necessary during fragmentation. With the support of ab initio quantum chemistry, it is demonstrated that BaH is an ideal diatomic precursor that can be laser cooled to a Doppler temperature of ~37 microKelvin with just two rovibronic transitions, the simplest molecular cooling scheme identified to date. Preparation of a hydrogen atom gas below the critical BEC temperature Tc is feasible with present cooling technology, with optical pulse control of the c...

  20. Universality of weakly bound dimers and Efimov trimers close to Li-Cs Feshbach resonances

    Science.gov (United States)

    Ulmanis, J.; Häfner, S.; Pires, R.; Kuhnle, E. D.; Weidemüller, M.; Tiemann, E.

    2015-05-01

    We study the interspecies scattering properties of ultracold Li-Cs mixtures in their two energetically lowest spin channels in the magnetic field range between 800 and 1000 G. Close to two broad Feshbach resonances (FR) we create weakly bound LiCs dimers by radio-frequency association and measure the dependence of their binding energy on the external magnetic field strength. Based on the binding energies and complementary atom loss spectroscopy of three other Li-Cs s-wave FRs we construct precise molecular singlet and triplet electronic ground state potentials using a coupled-channels calculation. We extract the Li-Cs interspecies scattering length as a function of the external field and obtain almost a ten-fold improvement in the precision of the values for the pole positions and widths of the s-wave FRs as compared to our previous work (Pires et al 2014 Phys. Rev. Lett. 112 250404). We discuss implications on the Efimov scenario and the universal geometric scaling for LiCsCs trimers.

  1. Bound and scattering properties in waveguides around free-space Feshbach resonance

    Science.gov (United States)

    Wang, Gaoren; Giannakeas, Panogiotis; Schmelcher, Peter

    2016-05-01

    The two-body bound and scattering properties in an one-dimensional (1D) harmonic waveguide in the vicinity of free-space magnetic Feshbach resonances are investigated based on the local frame transformation approach. The multichannel characteristics of the interatomic interaction is taken into account. We examine the crossing between the bound state in the waveguide and the ground level of the transverse confinement, i.e. when the bound state crosses the scattering threshold in the waveguide and turns into a continuum state. For s-wave collision, the crossing occurs at the magnetic field where the effective 1D interaction strength g1 D vanishes, and the effective 1D scattering length a1 D diverges. This observation indicates that the molecular formation or atom loss signal in a harmonic waveguide is expected at the magnetic field where a1 D is infinite. Molecule formation is absent at position of the confinement induced resonance which is characterized by the divergence of g1 D . Financial support from Alexander von Humboldt Foundation is acknowledged.

  2. Stochastic and equilibrium pictures of the ultracold Fano-Feshbach-resonance molecular conversion rate

    Science.gov (United States)

    Yamakoshi, Tomotake; Watanabe, Shinichi; Zhang, Chen; Greene, Chris H.

    2013-05-01

    The ultracold molecular conversion rate occurring in an adiabatic ramp through a Fano-Feshbach resonance is studied and compared in two statistical models. One model, the so-called stochastic phase-space sampling (SPSS) [Hodby , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.94.120402 94, 120402 (2005)] evaluates the overlap of two atomic distributions in phase space by sampling atomic pairs according to a phase-space criterion. The other model, the chemical equilibrium theory (ChET) [Watabe and Nikuni, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.77.013616 77, 013616 (2008)] considers atomic and molecular distributions in the limit of the chemical and thermal equilibrium. The present study applies SPSS and ChET to a prototypical system of K+K→ K2 in all the symmetry combinations, namely Fermi-Fermi, Bose-Bose, and Bose-Fermi cases. To examine implications of the phase-space criterion for SPSS, the behavior of molecular conversion is analyzed using four distinct geometrical constraints. Our comparison of the results of SPSS with those of ChET shows that while they appear similar in most situations, the two models give rise to rather dissimilar behaviors when the presence of a Bose-Einstein condensate strongly affects the molecule formation.

  3. Feshbach Resonance due to Coherent {lambda}-{sigma} Coupling in {sup 7}{sub {lambda}}He

    Energy Technology Data Exchange (ETDEWEB)

    Mon, San San; Nwe, Tin Tin [Department of Physics, Mandalay University (Myanmar); Myint, Khin Swe [Pro-Rector, Mandalay University (Myanmar)], E-mail: pro-rector@mptmail.net.mm; Akaishi, Y. [College of Science and Technology, Nihon University, Chiba, Japan and RIKEN Nishina Center, Saitama (Japan)

    2010-04-01

    Coherent {lambda}-{sigma} coupling effect in {sup 7}{sub {lambda}}He is analyzed within three-body framework of two coupled channels, {lambda}-t-t and {sigma}-{tau}-t, where {tau} represents trinulceon which is either {sup 3}H or {sup 3}He. The hyperon-trinucleon (Y{tau}) and trinucleon-trinucleon ({tau}{tau}) interactions are derived by folding G-matrices of YN and NN interactions with trinucleon density distributions. It is found that the binding energy of {sup 7}{sub {lambda}}He is 4.04 MeV below the {lambda}+t+t threshold without {lambda}-{sigma} coupling and the binding energy is increased to 4.46 MeV when the coupling effect is included. This state is 7.85 MeV above the {sup 6}He+{lambda} threshold and it may have a chance to be observed as a Feshbach resonance in {sup 7}Li (e,e{sup '}K{sup +}){sup 7}{sub {lambda}}He experiment done at Jefferson Lab.

  4. Analyses of Nucleon Scattering Based on the Modified Statistical Hauser - Feshbach - Weidenmueller Formalism.

    Science.gov (United States)

    Chan, Desmond Wing-Sum

    An S-matrix formalism of the statistical theory of nuclear reactions has been developed by Weidenmuller et al., based upon the Engelbrecht-Weidenmuller transformation and extended to cases where direct reactions are present as a means of deriving expressions for the fluctuation cross section going beyond the framework of conventional Hauser-Feshbach theory. This unified approach, from which a coherent sum of fluctuation and direct-interaction cross sections is combined to yield a net reaction cross section, provides a means of deriving a comprehensive and accurate theoretical description of the scattering process. Although a framework for the formal theory has been constructed, it had not previously been applied to the qualitative analyses of scattering data. As described in this thesis, a computer program "NANCY" has been compiled by modifying Tamura's coupled -channels code "JUPITOR-1" (through modifications suggested by Moldauer) and incorporating Smith's optical model routine "SCAT", as a means of generating the entire symmetric S -matrix. Using this program, computations were undertaken to determine numerically the energy-averaged cross sections for inelastic neutron scattering on ('232)Th and ('238)U from threshold to several MeV. With appropriate variation of coupling strengths between the ground state rotational band and vibrational levels good fits to the experimental data were attained, which compared favorably with theoretical results generated from conventional approaches.

  5. The Rb problem in massive AGB stars.

    Science.gov (United States)

    Pérez-Mesa, V.; García-Hernández, D. A.; Zamora, O.; Plez, B.; Manchado, A.; Karakas, A. I.; Lugaro, M.

    2017-03-01

    The asymptotic giant branch (AGB) is formed by low- and intermediate-mass stars (0.8 M_{⊙} develop thermal pulses (TP) and suffer extreme mass loss. AGB stars are the main contributor to the enrichment of the interstellar medium (ISM) and thus to the chemical evolution of galaxies. In particular, the more massive AGB stars (M > 4 M_{⊙}) are expected to produce light (e.g., Li, N) and heavy neutron-rich s-process elements (such as Rb, Zr, Ba, Y, etc.), which are not formed in lower mass AGB stars and Supernova explosions. Classical chemical analyses using hydrostatic atmospheres revealed strong Rb overabundances and high [Rb/Zr] ratios in massive AGB stars of our Galaxy and the Magellanic Clouds (MC), confirming for the first time that the ^{22}Ne neutron source dominates the production of s-process elements in these stars. The extremely high Rb abundances and [Rb/Zr] ratios observed in the most massive stars (specially in the low-metallicity MC stars) uncovered a Rb problem; such extreme Rb and [Rb/Zr] values are not predicted by the s-process AGB models, suggesting fundamental problems in our present understanding of their atmospheres. We present more realistic dynamical model atmospheres that consider a gaseous circumstellar envelope with a radial wind and we re-derive the Rb (and Zr) abundances in massive Galactic AGB stars. The new Rb abundances and [Rb/Zr] ratios derived with these dynamical models significantly resolve the problem of the mismatch between the observations and the theoretical predictions of the more massive AGB stars.

  6. Two-atom energy spectrum in a harmonic trap near a Feshbach resonance at higher partial waves

    Science.gov (United States)

    Suzuki, Akira; Liang, Yi; Bhaduri, Rajat K.

    2009-09-01

    Two atoms in an optical lattice may be made to interact strongly at higher partial waves near a Feshbach resonance. These atoms, under appropriate constraints, could be bosonic or fermionic. The universal l=2 energy spectrum for such a system, with a caveat, is presented in this paper and checked with the spectrum obtained by direct numerical integration of the Schrödinger equation. The results reported here extend those of Yip for p -wave resonance [S.-K. Yip, Phys. Rev. A 78, 013612 (2008)], while exploring the limitations of a universal expression for the spectrum for the higher partial waves.

  7. [Rb(18-crown-6][Rb([2.2.2]-cryptand]Rb2Sn9·5NH3

    Directory of Open Access Journals (Sweden)

    Stefanie Gaertner

    2011-05-01

    Full Text Available The crystal structure of the title compound, poly[[(4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosanerubidium] [[(1,4,7,10,13,16-hexaoxacyclooctadecanerubidium]di-μ-rubidium-μ-nonastannide] pentaammonia], {[Rb(C18H36N2O6][Rb3Sn9(C12H24O6C12H24O6]·5NH3}n represents the first ammoniate of a Zintl anion together with two different chelating substances, namely 18-crown-6 and [2.2.2]-cryptand. The involvement of these large molecules in the crystal structure of [Rb(18-crown-6][Rb([2.2.2]-cryptand]Rb2Sn9·5NH3 leads to the formation of a new structural motif, namely one-dimensionally extended double strands running parallel to [100] and built by Sn94− cages and Rb+ cations. The double strands are shielded by 18-crown-6 and [2.2.2]-cryptand. The cations are additionally coordinated by ammonia molecules. One of the four independent Rb+ cations is disordered over two sets of sites in a 0.74 (2:0.26 (2 ratio.

  8. Skin tumors Rb(eing uncovered

    Directory of Open Access Journals (Sweden)

    CLOTILDE eCOSTA

    2013-12-01

    Full Text Available The Rb1 gene was the first bona fide tumor suppressor identified and cloned more than 25 years ago. Since then, a plethora of studies have revealed the functions of pRb and the existence of a sophisticated and strictly regulated pathway that modulates such functional roles. An emerging paradox affecting Rb1 in cancer connects the relatively low number of mutations affecting Rb1 gene in specific human tumors, compared with the widely functional inactivation of pRb in most, if not in all, human cancers. The existence of a retinoblastoma family of proteins pRb, p107 and p130 and their potential unique and overlapping functions as master regulators of cell cycle progression and transcriptional modulation by similar processes, may provide potential clues to explain such conundrum. Here, we will review the development of different genetically engineered mouse models, in particular those affecting stratified epithelia, and how they have offered new avenues to understand the roles of the Rb family members and their targets in the context of tumor development and progression.

  9. Rb1 GENE MUTATIONS IN OSTEOSARCOMA

    Institute of Scientific and Technical Information of China (English)

    ZENG Ji-bin; SONG Yue; WANG Yi; SHI Yu-yuan

    1999-01-01

    @@ Genetic alternations, such as mutations caused inactivities of tumor suppressor gene, have been identified in a wide variety of tumors, including osteosarcoma. Osteosarcoma is the most frequent primary malignant bone tumor that occurs in the extremities of young adolescents in most cases. Because of the high frequent occurrence of this type of tumor in hereditary retinoblastoma patients, involvement of the Rb1 gene mutations was suspected in the development of osteosarcoma, and a few reports have shown alternations of the Rb1 gene in osteosarcoma. We studied Rb1 gene mutations in 9 osteosarcoma samples and one cell line (OS 732) to explore the types and mechanism of Rb1 gene mutations in osteosarcoma.

  10. RB975952 – Early maturing sugarcane cultivar

    Directory of Open Access Journals (Sweden)

    Monalisa Sampaio Carneiro

    2015-08-01

    Full Text Available RB975952 is an early maturing sugarcane cultivar released for the South-Central region of Brazil. It should be harvested between April and May, and it is recommended for planting in environments with medium to high production potential. RB975952 has high resistance levels to the main diseases of the crop, it also has a good shoot development after mechanical harvesting, and high sucrose yields.

  11. Lysine methylation regulates the pRb tumour suppressor protein.

    Science.gov (United States)

    Munro, S; Khaire, N; Inche, A; Carr, S; La Thangue, N B

    2010-04-22

    The pRb tumour suppressor protein has a central role in coordinating early cell cycle progression. An important level of control imposed on pRb occurs through post-translational modification, for example, phosphorylation. We describe here a new level of regulation on pRb, mediated through the targeted methylation of lysine residues, by the methyltransferase Set7/9. Set7/9 methylates the C-terminal region of pRb, both in vitro and in cells, and methylated pRb interacts with heterochromatin protein HP1. pRb methylation is required for pRb-dependent cell cycle arrest and transcriptional repression, as well as pRb-dependent differentiation. Our results indicate that methylation can influence the properties of pRb, and raise the interesting possibility that methylation modulates pRb tumour suppressor activity.

  12. RB: An essential player in adult neurogenesis.

    Science.gov (United States)

    Fong, Bensun C; Slack, Ruth S

    2017-01-01

    The fundamental mechanisms underlying adult neurogenesis remain to be fully clarified. Members of the cell cycle machinery have demonstrated key roles in regulating adult neural stem cell (NSC) quiescence and the size of the adult-born neuronal population. The retinoblastoma protein, Rb, is known to possess CNS-specific requirements that are independent from its classical role as a tumor suppressor. The recent study by Vandenbosch et al. has clarified distinct requirements for Rb during adult neurogenesis, in the restriction of proliferation, as well as long-term adult-born neuronal survival. However, Rb is no longer believed to be the main cell cycle regulator maintaining the quiescence of adult NSCs. Future studies must consider Rb as part of a larger network of regulatory effectors, including the other members of the Rb family, p107 and p130. This will help elucidate the contribution of Rb and other pocket proteins in the context of adult neurogenesis, and define its crucial role in regulating the size and fate of the neurogenic niche.

  13. Controlling the amplitude of soliton in a growing Bose-Einstein condensate by means of Feshbach resonance

    Institute of Scientific and Technical Information of China (English)

    He Zhang-Ming; Wang Deng-Long; Zhang Wei-Xi; Wang Feng-Jiao; Ding Jian-Wen

    2008-01-01

    By using Darboux transformation,this paper studies analytically the nonlinear dynamics of a one-dimensional growing Bose-Einstein condensate(BEC).It is shown that the growing model has an important effect on the amplitude of the soliton in the condensates.In the absence of the growing model,there exhibits the stable alternate bright solitons in the condensates.In the presence of the growing model,the obtained results show that the amplitude of the bright soliton decreases(increases)for the BEC growing coefficient Ω<0(Ω>0).Furthermore,we propose experimental protocols to manipulate the amplitude of the bright soliton by varying the scattering length via the Feshbach resonance in the fluture experiment.

  14. A consistent analysis of (p,p`) and (n,n`) reactions using the Feshbach-Kerman-Koonin model

    Energy Technology Data Exchange (ETDEWEB)

    Yoshioka, S.; Watanabe, Y.; Harada, M. [Kyushu Univ., Fukuoka (Japan)] [and others

    1997-03-01

    Double-differential proton emission cross sections were measured for proton-induced reactions on several medium-heavy nuclei ({sup 54,56}Fe, {sup 60}Ni, {sup 90}Zr, and {sup 93}Nb) at two incident energies of 14.1 and 26 MeV. The (p,p`) data for {sup 56}Fe and {sup 93}Nb were compared with available data of (n,n`) scattering for the same target nuclei and incident energies, and both data were analyzed using the Feshbach-Kerman-Koonin model to extract the strength V{sub 0} of the effective N-N interaction which is the only free parameter used in multistep direct calculations. (author)

  15. Crystal structure of Rb-elpasolite Rb{sub 2}NaAlF{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Yakubovich, O. V., E-mail: yakubol@geol.msu.ru; Kiryukhina, G. V.; Dimitrova, O. V. [Moscow State University, Faculty of Geology (Russian Federation)

    2013-05-15

    Single crystals of Rb{sub 2}NaAlF{sub 6}, the Rb analogue of the mineral elpasolite, are obtained in the NaF-Rb{sub 2}CO{sub 3}-Al{sub 2}O{sub 3}-Rb{sub 3}PO{sub 4}-H{sub 2}O system under hydrothermal conditions, and their structure is determined by X-ray diffraction (R = 0.0188): a = 8.3087(1) A, space group Fm3bar m, Z = 4, and {rho}{sub calcd} = 3.88 g/cm{sup 3}. The hypothesis that Rb elpasolite exists in nature in late associations of pegmatites enriched in rubidium is proposed.

  16. Proton instability of {sup 73}Rb

    Energy Technology Data Exchange (ETDEWEB)

    Jokinen, A. [CERN, Geneva (Switzerland). PPE Div.; Oinonen, M. [Univ. of Jyvaeskylae (Finland). Dept. of Physics; Aeystoe, J. [CERN, Geneva (Switzerland). PPE Div.]|[Univ. of Jyvaeskylae (Finland). Dept. of Physics] [and others; ISOLDE Collaboration

    1996-08-01

    The study of the stability of an astrophysically interesting nucleus {sup 73}Rb was performed by searching its {beta}{sup +} and proton decay at the ISOLDE facility at CERN. Light rubidium isotopes were produced in a spallation reaction of a niobium target induced by a pulsed 1 GeV proton beam. The previously reported proton-unbound character of {sup 73}Rb was confirmed and the upper limit for its production cross-section was reduced by more than one order of magnitude. (orig.)

  17. RB1CC1 activates RB1 pathway and inhibits proliferation and cologenic survival in human cancer.

    Directory of Open Access Journals (Sweden)

    Tokuhiro Chano

    Full Text Available RB1-inducible coiled-coil 1 (RB1CC1, also known as FIP200 plays a role in the enhancement of the RB1 pathway through the direct binding to a GC-rich region 201bp upstream (from the initiation ATG of the RB1 promoter. Here, we identified hSNF5 and p53 as the binding partners of RB1CC1 by immunoprecipitation and immunofluorescence assays. Interaction between these molecules and the RB1 pathway was analyzed by the assays of chromatin immunoprecipitation, luciferase-reporter, reverse transcription-polymerase chain reaction and immunoblot. The tumor growth suppression by RB1CC1 was evaluated by flow cytometry or by a cell growth assay. The nuclear RB1CC1 complex involving hSNF5 and/or p53 activated transcription of RB1, p16 and p21, and suppressed tumor cell growth. Furthermore, nuclear RB1CC1 expression significantly correlated with those of RB1 and p16 in breast cancer tissue in vivo, and the Ki-67 proliferation index was dependent on p53 as well as RB1CC1. The present study indicates that RB1CC1 together with hSNF5 and/or p53 enhances the RB1 pathway through transcriptional activation of RB1, p16 and p21. Evaluation of RB1CC1 expression combined with RB1 and p53 status is expected to provide useful information in clinical practice and future therapeutic strategies in breast cancer.

  18. Single-Particle Excitations and Effects of Hetero-Pairing Fluctuations in a Bose-Fermi Mixture with a Feshbach Resonance

    Science.gov (United States)

    Kharga, Digvijay; Inotani, Daisuke; Hanai, Ryo; Ohashi, Yoji

    2017-08-01

    We theoretically investigate normal-state properties of a gas mixture of single-component bosons and fermions with a hetero-nuclear Feshbach resonance. Including strong hetero-pairing fluctuations associated with the Feshbach resonance, we calculate single-particle density of states, as well as the spectral weight at various interaction strengths. For this purpose, we employ an improved T-matrix approximation (TMA), where the bare Bose Green's function in the non-selfconsistent TMA self-energy is modified so as to satisfy the Hugenholtz-Pines relation at the Bose-Einstein condensation (BEC) temperature TBEC. In the unitary regime at TBEC, we show that hetero-pairing fluctuations couple Fermi atomic excitations with Fermi molecular excitations, as well as with Bose atomic excitations. Although a similar coupling phenomenon by pairing fluctuations is known to give a pseudo-gapped density of states in the unitary regime of a two-component Fermi gas, such a dip structure is found to not appear even in the unitary limit of a Bose-Fermi mixture. It only appears in the strong-coupling regime. Instead, a spectral peak along the molecular dispersion appears in the spectral weight. We also clarify how this coupling phenomenon is seen in the Bose channel. Since a hetero-nuclear Feshbach resonance, as well as the formation of Bose-Fermi molecules, have been realized, our results would be useful for the study of strong-coupling properties of this unique quantum gas.

  19. Doing Business Economy Profile 2015 : Venezuela, RB

    OpenAIRE

    2014-01-01

    This economy profile for Doing Business 2015 presents the 11 Doing Business indicators for Venezuela RB. To allow for useful comparison, the profile also provides data for other selected economies (comparator economies) for each indicator. Doing Business 2015 is the 12th edition in a series of annual reports measuring the regulations that enhance business activity and those that constrain ...

  20. Progress of the ~(87)Rb Fountain Clock

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zi-Chao; WEI Rong; SHI Chun-Yan; LV De-Sheng; LI Tang; WANG Yu-Zhu

    2009-01-01

    A fountain atomic clock based on cold ~(87)Rb atoms has been in operation in our laboratory for several months.We therefore report the design of the rubidium fountain clock including its physical package,optical system and daily operation.Ramsey fringes have been attained with the signal to noise ratio of about 100.

  1. RB1: a prototype tumor suppressor and an enigma.

    Science.gov (United States)

    Dyson, Nicholas J

    2016-07-01

    The retinoblastoma susceptibility gene (RB1) was the first tumor suppressor gene to be molecularly defined. RB1 mutations occur in almost all familial and sporadic forms of retinoblastoma, and this gene is mutated at variable frequencies in a variety of other human cancers. Because of its early discovery, the recessive nature of RB1 mutations, and its frequency of inactivation, RB1 is often described as a prototype for the class of tumor suppressor genes. Its gene product (pRB) regulates transcription and is a negative regulator of cell proliferation. Although these general features are well established, a precise description of pRB's mechanism of action has remained elusive. Indeed, in many regards, pRB remains an enigma. This review summarizes some recent developments in pRB research and focuses on progress toward answers for the three fundamental questions that sit at the heart of the pRB literature: What does pRB do? How does the inactivation of RB change the cell? How can our knowledge of RB function be exploited to provide better treatment for cancer patients?

  2. The experiment on the saturation polarization of Rb vapour

    Institute of Scientific and Technical Information of China (English)

    Huang Xiang-You; You Pei-Lin; Du Wei-Min

    2004-01-01

    @@ A cylindrical capacitor containing rubidium vapour is made. The capacitance of it at. different voltages is measured under a certain Rb vapour pressure. The experimental C-V curve shows that the saturation polarization of Rb vapour is easily observed. The experiment further supports the idea that the Rb atom has a large permanent electric dipole moment.

  3. Trimers in the resonant (2+1)-fermion problem on a narrow Feshbach resonance: Crossover from Efimovian to hydrogenoid spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Castin, Yvan; Tignone, Edoardo [Laboratoire Kastler Brossel, Ecole Normale Superieure and CNRS, UPMC, 24 rue Lhomond, F-75231 Paris (France)

    2011-12-15

    We study the quantum three-body free-space problem of two same-spin-state fermions of mass m interacting with a different particle of mass M, on an infinitely narrow Feshbach resonance with infinite s-wave scattering length. This problem is made interesting by the existence of a tunable parameter, the mass ratio {alpha}=m/M. By a combination of analytical and numerical techniques, we obtain a detailed picture of the spectrum of three-body bound states, within each sector of fixed total angular momentum l. For {alpha} increasing from 0, we find that the trimer states first appear at the l-dependent Efimovian threshold {alpha}{sub c}{sup (l)}, where the Efimov exponent s vanishes, and that the entire trimer spectrum (starting from the ground trimer state) is geometric for {alpha} tending to {alpha}{sub c}{sup (l)} from above, with a global energy scale that has a finite and nonzero limit. For further increasing values of {alpha}, the least bound trimer states still form a geometric spectrum, with an energy ratio exp(2{pi}/|s|) that becomes closer and closer to unity, but the most bound trimer states deviate more and more from that geometric spectrum and eventually form a hydrogenoid spectrum.

  4. Fundamental and high-order anapoles in all-dielectric metamaterials via Fano–Feshbach modes competition

    KAUST Repository

    Gongora, J. S. Totero

    2017-02-01

    One of the most fascinating possibilities enabled by metamaterials is the strong reduction of the electromagnetic scattering from nanostructures. In dielectric nanoparticles, the formation of a minimal scattering state at specific wavelengths is associated with the excitation of photonic anapoles, which represent a peculiar type of radiationless state and whose existence has been demonstrated experimentally. In this work, we investigate the formation of anapole states in generic dielectric structures by applying a Fano-Feshbach projection scheme, a general technique widely used in the study of quantum mechanical open systems. By expressing the total scattering from the structure in terms of an orthogonal set of internal and external modes, defined in the interior and in the exterior of the dielectric structure, respectively, we show how anapole states are the result of a complex interaction among the resonances of the system and the surrounding environment. We apply our approach to a circular resonator, where we observe the formation of higher-order anapole states, which are originated by the superposition of several internal resonances of the system.

  5. Upper Bound to the Ionization Energy of 85Rb2

    CERN Document Server

    Bellos, M A; Banerjee, J; Ascoli, M; Allouche, A -R; Eyler, E E; Gould, P L; Stwalley, W C

    2013-01-01

    We report an upper bound to the ionization energy of 85Rb2 of 31348.0(6) cm-1, which also provides a lower bound to the dissociation energy D0 of 85Rb2+ of 6307.5(6) cm-1. These bounds were measured by the onset of autoionization of excited states of 85Rb2 below the 5s+7p atomic limit. We form 85Rb2 molecules via photoassociation of ultracold 85Rb atoms, and subsequently excite the molecules by single-photon ultraviolet transitions to states above the ionization threshold.

  6. 76 FR 24798 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-Trent 875-17, RB211-Trent 877-17, RB211...

    Science.gov (United States)

    2011-05-03

    ...-30-AD; Amendment 39-16657; AD 2011-08-07] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc (RR... 2. The FAA amends Sec. 39.13 by adding the following new AD: 2011-08-07 Rolls-Royce plc: Amendment... applies to Rolls-Royce plc (RR) RB211-Trent 875-17, RB211-Trent 877-17, RB211-Trent 884-17,...

  7. The multiple connections between pRB and cell metabolism.

    Science.gov (United States)

    Nicolay, Brandon N; Dyson, Nicholas J

    2013-12-01

    The pRB tumor suppressor is traditionally seen as an important regulator of the cell cycle. pRB represses the transcriptional activation of a diverse set of genes by the E2F transcription factors and prevents inappropriate S-phase entry. Advances in our understanding of pRB have documented roles that extend beyond the cell cycle and this review summarizes recent studies that link pRB to the control of cell metabolism. pRB has been shown to regulate glucose tolerance, mitogenesis, glutathione synthesis, and the expression of genes involved in central carbon metabolism. Several studies have demonstrated that pRB directly targets a set of genes that are crucial for nucleotide metabolism, and this seems likely to represent one of the ways by which pRB influences the G1/S-phase transition and S-phase progression.

  8. Three Magnetic Rotation Bands in 84^Rb

    CERN Document Server

    Shen, Shuifa; Han, Guangbing; Wen, Shuxian; Yan, Yupeng; Wu, Xiaoguang; Zhu, Lihua; He, Chuangye; Li, Guangsheng

    2016-01-01

    High-spin states in $^{84}$Rb are studied by using the $^{70}$Zn($^{18}$O, p3n)$^{84}$Rb reaction at beam energy of 75 MeV. Three high-lying negative-parity bands are established, whose level spacings are very regular, i.e., there don't exist signature splitting. The dipole character of the transitions of these three bands is assigned by the $\\gamma$-$\\gamma$ directional correlations of oriented states (DCO) intensity ratios and the multipolarity M1 is suggested by the analogy to multiparticle excitations in neighboring nuclei. The strong M1 and weak or no E2 transitions are observed. All these characteristic features show they are magnetic rotation bands.

  9. The origin of the RB1 imprint.

    Directory of Open Access Journals (Sweden)

    Deniz Kanber

    Full Text Available The human RB1 gene is imprinted due to a differentially methylated CpG island in intron 2. This CpG island is part of PPP1R26P1, a truncated retrocopy of PPP1R26, and serves as a promoter for an alternative RB1 transcript. We show here by in silico analyses that the parental PPP1R26 gene is present in the analysed members of Haplorrhini, which comprise Catarrhini (Old World Monkeys, Small apes, Great Apes and Human, Platyrrhini (New World Monkeys and tarsier, and Strepsirrhini (galago. Interestingly, we detected the retrocopy, PPP1R26P1, in all Anthropoidea (Catarrhini and Platyrrhini that we studied but not in tarsier or galago. Additional retrocopies are present in human and chimpanzee on chromosome 22, but their distinct composition indicates that they are the result of independent retrotransposition events. Chimpanzee and marmoset have further retrocopies on chromosome 8 and chromosome 4, respectively. To examine the origin of the RB1 imprint, we compared the methylation patterns of the parental PPP1R26 gene and its retrocopies in different primates (human, chimpanzee, orangutan, rhesus macaque, marmoset and galago. Methylation analysis by deep bisulfite sequencing showed that PPP1R26 is methylated whereas the retrocopy in RB1 intron 2 is differentially methylated in all primates studied. All other retrocopies are fully methylated, except for the additional retrocopy on marmoset chromosome 4, which is also differentially methylated. Using an informative SNP for the methylation analysis in marmoset, we could show that the differential methylation pattern of the retrocopy on chromosome 4 is allele-specific. We conclude that the epigenetic fate of a PPP1R26 retrocopy after integration depends on the DNA sequence and selective forces at the integration site.

  10. Experimental determination and prediction of activity coefficients of RbCl in aqueous (RbCl+RbNO{sub 3}) mixture at T=298.15 K

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Jun [Chemical Engineering Department, Henan University of Science and Technology, 48 Xiyuan Road, Luoyang, Henan 471003 (China)]. E-mail: zhjabc@mail.haust.edu.cn; Huang Xingyuan [Chemical Engineering Department, Henan University of Science and Technology, 48 Xiyuan Road, Luoyang, Henan 471003 (China); Xia Shuping [Institute of Salt Lakes, Chinese Academy of Sciences, Xi' an 710043 (China)

    2005-11-15

    Activity coefficients for rubidium chloride in the (RbCl+RbNO{sub 3}+H{sub 2}O) ternary system were determined from electromotive force (emf) measurements of the cell:Rb-ionselectiveelectrode(ISE) vertical bar RbCl(m{sub A}),RbNO{sub 3}(m{sub B}),H{sub 2}O vertical bar Ag vertical bar AgClat T=298.15 K and over total ionic strengths from (0.01 upto 3.50) mol.kg{sup -1}. The Rb{sup +} ion selective electrode (Rb-ISE) and Ag vertical bar AgCl electrode used in this work were made in our laboratory and had reasonably good Nernst responses, which demonstrate that the emf method can be applied to measure the above system with high precision. The experimental data were analyzed using the Harned rule and Pitzer model. The Harned coefficients and the Pitzer binary and ternary ionic interaction parameters for the system have been evaluated. The experimental results obey the Harned rule, and the Pitzer model can be used to describe this aqueous system satisfactorily. The activity coefficients of RbNO{sub 3}, the osmotic coefficients of the mixtures and the excess free energy of mixing were also calculated.

  11. Circular Dichroism of RbHe and RbN$_2$ Molecules

    CERN Document Server

    Lancor, B; Wyllie, R; Walker, T G

    2010-01-01

    We present measurements of the circular dichroism of optically pumped Rb vapor near the D1 resonance line. Collisions with the buffer gases $^3$He and N$_2$ reduce the transparency of the vapor, even when fully polarized. We use two methods to measure this effect, show that the He results can be understood from RbHe potential curves, and show how this effect conspires with the spectral profile of the optical pumping light to increase the laser power demands for optical pumping of very optically thick samples.

  12. Dynamic Changes in Ginsenoside Rb 2 and Rb3 Content in Solid-state Fermentation%人参须固态发酵中皂苷 Rb 2与 Rb 3的动态变化

    Institute of Scientific and Technical Information of China (English)

    闫梅霞; 崔丽丽; 许世泉; 刘俊霞; 王英平

    2014-01-01

    以人参须为发酵基质进行赤芝双向固态发酵,测定发酵过程中人参皂苷Rb2和Rb3的含量,分析固态发酵对其影响。发酵作用使基质中Rb2和Rb3含量发生显著变化,但2种皂苷含量变化不同。Rb2在发酵初期和发酵后期都出现含量先升高后降低的过程,Rb3仅在发酵初期含量先升高后降低,发酵结束时基质中未检测到2种皂苷。%Bidirectional solid-state fermentation was carried out through the strains of Ganoderma lucidum in ginseng .The content of ginseno-side Rb2 and Rb3 was determined and the impact on the ginsenoside by solid -state fermentation was analyzed .The content of Rb2 and Rb3 changed significantly through the fermentation ,but the two kinds of ginsenoside content varied differently .The content of Rb2 increased in the early fermentation stage ,then decreased in the late fermentation stage ,the level of Rb3 increased then decreased only in the early fermentation stage ,the two kinds of ginsenoside content was 0 by the end of the fermentation .

  13. Permanent Electric Dipole Moment of an Rb Atom

    Institute of Scientific and Technical Information of China (English)

    黄湘友; 游佩林

    2002-01-01

    We experimentally determine the conjecture that hydrogen-like atoms such as Rb and Cs may have large permanent electric dipole moments (EDMs). The saturated Rb vapour fills a cylindrical capacitor in the experiment.The influence of the vapour dielectric medium on capacitance is measured with a digital capacitance meter. Supposing that the measurement influence comes from the permanent EDMs of Rb atoms, from the experimental result we find that the EDM is large, i.e. dRb ≥ 8.6e × 10-9 cm.

  14. Quorum Sensing Activity in Pandoraea pnomenusa RB38

    Directory of Open Access Journals (Sweden)

    Robson Ee

    2014-06-01

    Full Text Available Strain RB38 was recovered from a former dumping area in Malaysia. MALDI-TOF mass spectrometry and genomic analysis identified strain RB-38 as Pandoraea pnomenusa. Various biosensors confirmed its quorum sensing properties. High resolution triple quadrupole liquid chromatography–mass spectrometry analysis was subsequently used to characterize the N-acyl homoserine lactone production profile of P. pnomenusa strain RB38, which validated that this isolate produced N-octanoyl homoserine lactone as a quorum sensing molecule. This is the first report of the production of N-octanoyl homoserine lactone by P. pnomenusa strain RB38.

  15. Selective Chemosensitization of Rb Mutant Cells

    Science.gov (United States)

    2001-07-01

    3 jopaA o E +•» to o ü 2 3 O) U. Vt3*> OOCd» Vl.3» (0 O CM ll I S j 41 • A I O O) Di (0 o CM • o 00 CO Q. o o Q. Ö...Rb) protein, and inac- tivation of both is essential for viral transformation (Lane and Crawford 1979; Linzer and Levine 1979; De- Caprio et al...wild-type MEFs expressing El A dis - played an ~10-fold increase in p53 and Mdm2 levels as compared to their ARF-deficient counterparts, the abso

  16. Molecular Mechanisms of pRB Function in Differentiation Contributing to pRB Mediated Tumor Suppression

    Science.gov (United States)

    2002-06-01

    mutations result in elimination protein-binding functions of the A/B pocket. 1. Using coimmunoprecipitation assays for detection of pRB interacting proteins My...chromatin/nuclear matrix. Another caviat is that pRB interacting proteins are presumably low-extractable nuclear proteins. Also, epitope tag might be... interacting proteins . Due to the failure to detect selective pRB complexes applying immunoprecipitation, I used a modified yeast two-hybrid assay as a backup

  17. Identification of the genomic mutation in Epha4(rb-2J/rb-2J) mice.

    Science.gov (United States)

    Mohd-Zin, Siti W; Abdullah, Nor-Linda; Abdullah, Aminah; Greene, Nicholas D E; Cheah, Pike-See; Ling, King-Hwa; Yusof, Hadri; Marwan, Ahmed I; Williams, Sarah M; York, Kerri T; Ahmad-Annuar, Azlina; Abdul-Aziz, Noraishah M

    2016-07-01

    The EphA4 receptor tyrosine kinase is involved in numerous cell-signalling activities during embryonic development. EphA4 has the ability to bind to both types of ephrin ligands, the ephrinAs and ephrinBs. The C57BL/6J-Epha4rb-2J/GrsrJ strain, denoted Epha4(rb-2J/rb-2J), is a spontaneous mouse mutant that arose at The Jackson Laboratory. These mutants exhibited a synchronous hind limb locomotion defect or "hopping gait" phenotype, which is also characteristic of EphA4 null mice. Genetic complementation experiments suggested that Epha4(rb-2J) corresponds to an allele of EphA4, but details of the genomic defect in this mouse mutant are currently unavailable. We found a single base-pair deletion in exon 9 resulting in a frame shift mutation that subsequently resulted in a premature stop codon. Analysis of the predicted structure of the truncated protein suggests that both the kinase and sterile α motif (SAM) domains are absent. Definitive determination of genotype is needed for experimental studies of mice carrying the Epha4(rb-2J) allele, and we have also developed a method to ease detection of the mutation through RFLP. Eph-ephrin family members are reportedly expressed as numerous isoforms. Hence, delineation of the specific mutation in EphA4 in this strain is important for further functional studies, such as protein-protein interactions, immunostaining and gene compensatory studies, investigating the mechanism underlying the effects of altered function of Eph family of receptor tyrosine kinases on phenotype.

  18. Ultracold atom-molecule collisions and bound states in magnetic fields: tuning zero-energy Feshbach resonances in He-NH (3Sigma-)

    CERN Document Server

    Gonzalez-Martinez, M L; Gonzalez-Martinez, Maykel Leonardo; Hutson, Jeremy M.

    2006-01-01

    We have generalized the BOUND and MOLSCAT packages to allow calculations in basis sets where the monomer Hamiltonians are off-diagonal and used the new capability to carry out bound-state and scattering calculations on 3He-NH and 4He-NH as a function of magnetic field. Following the bound-state energies to the point where they cross thresholds gives very precise predictions of the magnetic fields at which zero-energy Feshbach resonances occur. We have used this to locate and characterize two very narrow Feshbach resonances in 3He-NH. Such resonances can be used to tune elastic and inelastic collision cross sections, and sweeping the magnetic field across them will allow a form of quantum control in which separated atoms and molecules are associated to form complexes. For the first resonance, where only elastic scattering is possible, the scattering length shows a pole as a function of magnetic field and there is a very large peak in the elastic cross section. For the second resonance, however, inelastic scatt...

  19. RB, the conductor that orchestrates life, death and differentiation.

    Science.gov (United States)

    Khidr, L; Chen, P-L

    2006-08-28

    The retinoblastoma susceptibility gene was the first tumor suppressor gene identified in humans and the first tumor suppressor gene knocked out by targeted deletion in mice. RB serves as a transducer between the cell cycle machinery and promoter-specific transcription factors, its most documented activity being the repression of the E2F family of transcription factors, which regulate the expression of genes involved in cell proliferation and survival. Recent investigations of RB function suggest that it works as a fundamental regulator to coordinate pathways of cellular growth and differentiation. In this review, we unravel the novel role of an equally important aspect of RB in downregulating the differentiation inhibitor EID-1 during cellular differentiation by teasing apart the signal, which elicit differentiation and limit cell cycle progression, since the molecular mechanisms relating to RB activation of differentiation is much less understood. We review the various roles for RB in differentiation of neurons, muscle, adipose tissue, and the retina. In addition, we provide an update for the current models of the role of RB in cell cycle to entry and exit, extending the view toward chromatin remodeling and expose the dichotomies in the regulation of RB family members. We conclude with a discussion of a novel RB regulatory network, incorporating the dynamic contribution of EID family proteins.

  20. Precision study of the $\\beta$-decay of $^{74}$Rb

    CERN Multimedia

    Van Duppen, P L E; Lunney, D

    2002-01-01

    We are proposing a high-resolution study of the $\\beta$-decay of $^{74}$Rb in order to extrapolate our precision knowledge of the superallowed $\\beta$-decays from the sd and fp shells towards the medium-heavy Z=N nuclei. The primary goal is to provide new data for testing the CVC hypothesis and the unitarity condition of the CKM matrix of the Standard Model. The presented programme would involve the careful measurements of the decay properties of $^{74}$Rb including the branching ratios to the excited states as well as the precise determination of the decay energy of $^{74}$Rb. The experimental methods readily available at ISOLDE include high-transmission conversion electron spectroscopy, $\\gamma$-ray spectroscopy as well as the measurements of the masses of $^{74}$Rb and $^{74}$Kr using two complementary techniques, ISOLTRAP and MISTRAL. The experiment would rely on a high-quality $^{74}$Rb beam available at ISOLDE with adequate intensity.

  1. Analysis list: RB1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available RB1 Prostate,Uterus + hg19 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/R...B1.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/target/RB1.5.tsv http://dbarchive.biosciencedbc.jp/...kyushu-u/hg19/target/RB1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/RB1.Prostate.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/RB1.Uterus.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/hg19/colo/Prostate.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/colo/Uterus.gml ...

  2. Improved RB-HARQ scheme based on structured LDPC codes

    Institute of Scientific and Technical Information of China (English)

    WANG Wen-jun; LIN Yue-wei; YAN Yuan

    2007-01-01

    Reliability-based hybrid automatic repeat request (ARQ) (RB-HARQ) is a recently introduced approach to incremental-redundancy ARQ. In RB-HARQ scheme, the bits that are to be retransmitted are adaptively selected at the receiver based on the estimated bit reliability. It could result in significant performance gain but requires huge overhead in the feedback channel. In this study, an improved RB-HARQ scheme (IRB-HARQ) for structured low-density parity-check codes is proposed, which simplifies the comparison operations needed to search the bits to be retransmitted and outperforms the RB-HARQ scheme in consideration of the bit transmission power for the requesting messages on the feedback link. Simulation results show that the IRB-HARQ scheme is more efficient and practical than the RB-HARQ scheme.

  3. 75 FR 51654 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-22B and RB211-524 Series Turbofan Engines

    Science.gov (United States)

    2010-08-23

    ...-10] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc (RR) RB211-22B and RB211-524 Series.... The FAA amends Sec. 39.13 by adding the following new AD: 2010-17-10 Rolls-Royce plc: Amendment 39... AD applies to Rolls-Royce plc RB211-22B series and RB211-524B4-D-02, RB211-524D4-19,...

  4. RB1 Methylation by SMYD2 Enhances Cell Cycle Progression through an Increase of RB1 Phosphorylation

    Directory of Open Access Journals (Sweden)

    Hyun-Soo Cho

    2012-06-01

    Full Text Available It is well known that RB functions are regulated by posttranslational modifications such as phosphorylation and acetylation, but the significance of lysine methylation on RB has not been fully elucidated. Our expression analysis of SMYD2 by quantitative real-time polymerase chain reaction showed that expression levels of SMYD2 are significantly elevated in human bladder carcinomas compared with nonneoplastic bladder tissues (P < .0001, and its expression levels in tumor tissues were much higher than those of any other normal tissues. SMYD2 knockdown resulted in the suppression of cancer cell growth, and cell cycle analysis indicated that SMYD2 might play a crucial role in the G1/S transition. According to an in vitro methyltransferase assay, we found that SMYD2 methylates RB1 protein, and liquid chromatography-tandem mass spectrometry analysis revealed lysine 810 of RB1 to be methylated by SMYD2. Importantly, this methylation enhanced Ser 807/811 phosphorylation of RB1 both in vitro and in vivo. Furthermore, we demonstrated that methylated RB1 accelerates E2F transcriptional activity and promotes cell cycle progression. SMYD2 is an important oncoprotein in various types of cancer, and SMYD2-dependent RB1 methylation at lysine 810 promotes cell cycle progression of cancer cells. Further study may explore SMYD2-dependent RB1 methylation as a potential therapeutic target in human cancer.

  5. Observation of Quantum Beating in rb at 2.1 THz and 18.2 THz: Long-Range Rb^{*}-Rb Interactions.

    Science.gov (United States)

    Goldshlag, William; Ricconi, Brian J.; Eden, J. Gary

    2017-06-01

    The interaction of Rb 7s ^{2}S_{1/2}, 5d ^{2}D_{3/2,5/2} and 5p ^{2}P_{3/2} atoms with the background species at long range (100-1000Å) has been observed by pump-probe ultrafast laser spectroscopy. Parametric four-wave mixing in Rb vapor with pairs of 50-70 fs pulses produces coherent Rb 6P-5S emission at 420 nm that is modulated by Rb quantum beating. The two dominant beating frequencies are 18.2 THz and 2.07 THz, corresponding to quantum beating between 7S and 5D states and to the (5D-5P_{3/2})-(5P_{3/2}-5S) defect, respectively. Analysis of Rabi oscillations in these pump-probe experiments allows for the mean interaction energy at long range to be determined. The figure shows Fourier transform spectra of representative Rabi oscillation waveforms. The waveform and spectrum at left illustrate quantum beating in Rb at 2.1 THz. The spectrum at right is dominated by the 18.2 THz frequency component generated by 7S-5D beating in Rb. Insets show respective temporal behaviors of the 6P-5S line near the coherent transient (zero interpulse delay).

  6. A cold 87Rb atomic beam

    Institute of Scientific and Technical Information of China (English)

    Wang Xiao-Jia; Feng Yan-Ying; Xue Hong-Bo; Zhou Zhao-Ying; Zhang Wen-Dong

    2011-01-01

    We demonstrate an experimental setup for the production of a beam source of cold 87Rb atoms.The atoms are extracted from a trapped cold atomic cloud in an unbalanced three-dimensional magneto-optical trap.Via a radiation pressure difference generated by a specially designed leak tunnel along one trapping laser beam,the atoms are pushed out continuously with low velocities and a high flux.The most-probable velocity in the beam is varied from 9 m/s to 19 m/s by varying the detuning of the trapping laser beams in the magneto-optical trap and the flux can be tuned up to 4× 109 s-1 by increasing the intensity of the trapping beams.We also present a simple model for describing the dependence of the beam performance on the magneto-optical trap trapping laser intensity and the detuning.

  7. Optical pumping in a microfabricated Rb vapor cell using a microfabricated Rb discharge light source

    Energy Technology Data Exchange (ETDEWEB)

    Venkatraman, V.; Kang, S.; Affolderbach, C.; Mileti, G., E-mail: gaetano.mileti@unine.ch [Laboratoire Temps-Fréquence, University of Neuchâtel, Neuchâtel 2000 (Switzerland); Shea, H. [Microsystems for Space Technologies Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), Neuchâtel 2002 (Switzerland)

    2014-02-03

    Miniature (Rb discharge lamp light source, as well as (2) a conventional glass-blown Rb discharge lamp. The microfabricated Rb lamp cell is a dielectric barrier discharge (DBD) light source, having the same inner cell volume of around 40 mm{sup 3} as that of the resonance cell, both filled with suitable buffer gases. A miniature (∼2 cm{sup 3} volume) test setup based on the M{sub z} magnetometer interrogation technique was used for observation of optical-radiofrequency double-resonance signals, proving the suitability of the microfabricated discharge lamp to introduce efficient optical pumping. The pumping ability of this light source was found to be comparable to or even better than that of a conventional glass-blown lamp. The reported results indicate that the micro-fabricated DBD discharge lamp has a high potential for the development of a new class of miniature atomic clocks, magnetometers, and quantum sensors.

  8. Proteomic analysis of pRb loss highlights a signature of decreased mitochondrial oxidative phosphorylation.

    Science.gov (United States)

    Nicolay, Brandon N; Danielian, Paul S; Kottakis, Filippos; Lapek, John D; Sanidas, Ioannis; Miles, Wayne O; Dehnad, Mantre; Tschöp, Katrin; Gierut, Jessica J; Manning, Amity L; Morris, Robert; Haigis, Kevin; Bardeesy, Nabeel; Lees, Jacqueline A; Haas, Wilhelm; Dyson, Nicholas J

    2015-09-01

    The retinoblastoma tumor suppressor (pRb) protein associates with chromatin and regulates gene expression. Numerous studies have identified Rb-dependent RNA signatures, but the proteomic effects of Rb loss are largely unexplored. We acutely ablated Rb in adult mice and conducted a quantitative analysis of RNA and proteomic changes in the colon and lungs, where Rb(KO) was sufficient or insufficient to induce ectopic proliferation, respectively. As expected, Rb(KO) caused similar increases in classic pRb/E2F-regulated transcripts in both tissues, but, unexpectedly, their protein products increased only in the colon, consistent with its increased proliferative index. Thus, these protein changes induced by Rb loss are coupled with proliferation but uncoupled from transcription. The proteomic changes in common between Rb(KO) tissues showed a striking decrease in proteins with mitochondrial functions. Accordingly, RB1 inactivation in human cells decreased both mitochondrial mass and oxidative phosphorylation (OXPHOS) function. RB(KO) cells showed decreased mitochondrial respiratory capacity and the accumulation of hypopolarized mitochondria. Additionally, RB/Rb loss altered mitochondrial pyruvate oxidation from (13)C-glucose through the TCA cycle in mouse tissues and cultured cells. Consequently, RB(KO) cells have an enhanced sensitivity to mitochondrial stress conditions. In summary, proteomic analyses provide a new perspective on Rb/RB1 mutation, highlighting the importance of pRb for mitochondrial function and suggesting vulnerabilities for treatment.

  9. Ginsenoside Rb1 directly scavenges hydroxyl radical and hypochlorous acid.

    Science.gov (United States)

    Lü, Jian-Ming; Weakley, Sarah M; Yang, Zhen; Hu, Ming; Yao, Qizhi; Chen, Changyi

    2012-01-01

    Reactive oxygen species (ROS) have been implicated in a variety of inflammatory diseases including cardiovascular disease (CVD), cancer, diabetes, Alzheimer's disease, autism, cataracts and aging. When endogenous mechanisms for the maintenance of redox homeostasis are overwhelmed, dietary intake of antioxidants contributes substantially to balancing the body's oxidant/antioxidant status. Ginsenosides are thought to be primarily responsible for the pharmacological effect of P. ginseng root extracts on oxidative stress and inflammation. However, little is known about the underlying antioxidant mechanisms of individual ginsenoside; specifically, the reactivity of ginsenoside Rb1 with ROS has not been well studied. We found that Rb1 can significantly and selectively reduce hydroxyl radical (●OH) and hypochlorous acid (HOCl), two of the strongest ROS, with unique molecular mechanisms in a cell-free system. Rb1 directly scavenges the ●OH and protects plasmid DNA from damage induced by ●OH. ●OH likely attacks the double bond on the side chain of Rb1 as well as hydrogen atoms adjacent to the -OH groups, including those of sugar moieties. Rb1 also shows a high reactivity to HOCl and effectively inhibits HOCl-induced tyrosine chlorination in a cell free system. HOCl is added to the double bond of Rb1; the -Cl group and -OH group of HOCl possibly bond at C-24 and C-25 of Rb1 based on the regioselectivity of Markovnikov's Rule. To our knowledge, this is the first demonstration that ginsenoside Rb1 scavenges HOCl and protects tyrosine from HOCl-induced chlorination. Thus, this study reveals unique antioxidant mechanisms of individual ginsenoside Rb1, which may contribute to the pharmacological effect of P. ginseng and to the development of effective strategies for clinical applications of ginsenosides.

  10. Combining electric and magnetic static field for the tuning of the lifetime of zero energy Feshbach resonances: Application to 3He+NH collisions

    CERN Document Server

    Stoecklin, T

    2009-01-01

    We study the variation of the positions of two magnetically tuned Zero energy Feshbach resonances when a parallel superimposed electric field is applied. We show that their variation as a function of the electric field follows a simple analytical law and is then predictable. We find that depending on the initial state of the diatomic molecule the resonance is either shifted to higher or to lower values of the magnetic field when the electric field is applied. We calculate the Close Coupling lifetimes of these resonances and show that they also follow a simple law as a function of both the magnetic and the electric field. We demonstrate using this expression that the lifetime of the resonances can be maximised by choosing an appropriate value of the applied electric and found a good agreement with the results of our Close Coupling calculations. These results could be checked in future experiments dedicated to the 3He + NH collisions

  11. Unitary boson-boson and boson-fermion mixtures: third virial coefficient and three-body parameter on a narrow Feshbach resonance

    Science.gov (United States)

    Endo, Shimpei; Castin, Yvan

    2016-11-01

    We give exact integral expressions of the third cluster or virial coefficients of binary mixtures of ideal Bose or Fermi gases, with interspecies interactions of zero range and infinite s-wave scattering length. In general the result depends on three-body parameters Rt appearing in three-body contact conditions, because an Efimov effect is present or because the mixture is in a preefimovian regime with a mass ratio close to an Efimov-effect threshold. We give a new, exact integral expression of Rt for the microscopic narrow Feshbach resonance model. A divergence of Rt in the preefimovian regime at a scaling exponent s = 1 / 2 is predicted and physically discussed. The analytical results are applied to typical species used in cold atom experiments.

  12. Vibrational Feshbach resonances in near-threshold HOCO - photodetachment: A theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Miyabe, S.; Haxton, D. J.; Lawler, K. V.; Orel, A. E.; McCurdy, C. W.; Rescigno, T. N.

    2011-04-01

    The results of a theoretical study of HOCO- photodetachment are presented with a view toward understanding the origin of two peaks observed by Lu and Continetti [Phys. Rev. Lett. 99, 113005 (2007)] in the photoelectron kinetic energy spectrum very close to threshold. It is shown that the peaks can be attributed to vibrational Feshbach resonances of dipole-bound trans-HOCO-, and not s- and p-wave shape resonances as previously assumed. Fixed-nuclei variational electron-HOCO scattering calculations are used to compute photodetachment cross sections and laboratory-frame photoelectron angular distributions. Finally, the calculations show a broad A''(π*)-shape resonance several electron volts above threshold.

  13. Number-Theory in Nuclear-Physics in Number-Theory: Non-Primality Factorization As Fission VS. Primality As Fusion; Composites' Islands of INstability: Feshbach-Resonances?

    Science.gov (United States)

    Siegel, Edward

    2011-10-01

    Numbers: primality/indivisibility/non-factorization versus compositeness/divisibility /factor-ization, often in tandem but not always, provocatively close analogy to nuclear-physics: (2 + 1)=(fusion)=3; (3+1)=(fission)=4[=2 × 2]; (4+1)=(fusion)=5; (5 +1)=(fission)=6[=2 × 3]; (6 + 1)=(fusion)=7; (7+1)=(fission)=8[= 2 × 4 = 2 × 2 × 2]; (8 + 1) =(non: fission nor fusion)= 9[=3 × 3]; then ONLY composites' Islands of fusion-INstability: 8, 9, 10; then 14, 15, 16,... Could inter-digit Feshbach-resonances exist??? Applications to: quantum-information/computing non-Shore factorization, millennium-problem Riemann-hypotheses proof as Goodkin BEC intersection with graph-theory ``short-cut'' method: Rayleigh(1870)-Polya(1922)-``Anderson'' (1958)-localization, Goldbach-conjecture, financial auditing/accounting as quantum-statistical-physics;... abound!!!

  14. Silencing of RB1 and RB2/P130 during adipogenesis of bone marrow stromal cells results in dysregulated differentiation.

    Science.gov (United States)

    Capasso, Stefania; Alessio, Nicola; Di Bernardo, Giovanni; Cipollaro, Marilena; Melone, Mariarosa Ab; Peluso, Gianfranco; Giordano, Antonio; Galderisi, Umberto

    2014-01-01

    Bone marrow adipose tissue (BMAT) is different from fat found elsewhere in the body, and only recently have some of its functions been investigated. BMAT may regulate bone marrow stem cell niche and plays a role in energy storage and thermogenesis. BMAT may be involved also in obesity and osteoporosis onset. Given the paramount functions of BMAT, we decided to better clarify the human bone marrow adipogenesis by analyzing the role of the retinoblastoma gene family, which are key players in cell cycle regulation. Our data provide evidence that the inactivation of RB1 or RB2/P130 in uncommitted bone marrow stromal cells (BMSC) facilitates the first steps of adipogenesis. In cultures with silenced RB1 or RB2/P130, we observed an increase of clones with adipogenic potential and a higher percentage of cells accumulating lipid droplets. Nevertheless, the absence of RB1 or RB2/P130 impaired the terminal adipocyte differentiation and gave rise to dysregulated adipose cells, with alteration in lipid uptake and release. For the first time, we evidenced that RB2/P130 plays a role in bone marrow adipogenesis. Our data suggest that while the inactivation of retinoblastoma proteins may delay the onset of last cell division and allow more BMSC to be committed to adipocyte, it did not allow a permanent cell cycle exit, which is a prerequisite for adipocyte terminal maturation.

  15. A multinuclear solid-state NMR study of alkali metal ions in tetraphenylborate salts, M[BPh4] (M = Na, K, Rb and Cs): what is the NMR signature of cation-pi interactions?

    Science.gov (United States)

    Wu, Gang; Terskikh, Victor

    2008-10-16

    We report a multinuclear solid-state ( (23)Na, (39)K, (87)Rb, (133)Cs) NMR study of tetraphenylborate salts, M[BPh 4] (M = Na, K, Rb, Cs). These compounds are isostructural in the solid state with the alkali metal ion surrounded by four phenyl groups resulting in strong cation-pi interactions. From analyses of solid-state NMR spectra obtained under stationary and magic-angle spinning (MAS) conditions at 11.75 and 21.15 T, we have obtained the quadrupole coupling constants, C Q, and the chemical shift tensor parameters for the alkali metal ions in these compounds. We found that the observed quadrupole coupling constant for M (+) in M[BPh 4] is determined by a combination of nuclear quadrupole moment, Sternheimer antishielding factor, and unit cell dimensions. On the basis of a comparison between computed paramagnetic and diamagnetic contributions to the total chemical shielding values for commonly found cation-ligand interactions, we conclude that cation-pi interactions give rise to significantly lower paramagnetic shielding contributions than other cation-ligand interactions. As a result, highly negative chemical shifts are expected to be the NMR signature for cations interacting exclusively with pi systems.

  16. RB1 mutation spectrum in a comprehensive nationwide cohort of retinoblastoma patients

    NARCIS (Netherlands)

    Dommering, Charlotte J.; Mol, Berber M.; Moll, Annette C.; Burton, Margaret; Cloos, Jacqueline; Dorsman, Josephine C.; Meijers-Heijboer, Hanne; van der Hout, Annemarie H.

    2014-01-01

    Background Retinoblastoma (Rb) is a childhood cancer of the retina, commonly initiated by biallelic inactivation of the RB1 gene. Knowledge of the presence of a heritable RB1 mutation can help in risk management and reproductive decision making. We report here on RB1 mutation scanning in a unique na

  17. Radioactivity Measurement of Short Life Nuclide 89Rb

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>The radioactivity of short life nuclide 89Rb produced by fast radiochemical separation was measured by the digital coincidence counting (DCC) system. In this experiment, there were a large quantity of impurities

  18. Scattering lengths in isotopologues of the RbYb system

    CERN Document Server

    Borkowski, Mateusz; Ciuryło, Roman; Julienne, Paul S; K{\\ke}dziera, Dariusz; Mentel, Łukasz; Tecmer, Paweł; Münchow, Frank; Bruni, Christian; Görlitz, Axel

    2013-01-01

    We model the binding energies of rovibrational levels of the RbYb molecule using experimental data from two-color photoassociation spectroscopy in mixtures of ultracold $^{87}$Rb with various Yb isotopes. The model uses a theoretical potential based on state-of-the-art \\emph{ab initio} potentials, further improved by least-squares fitting to the experimental data. We have fixed the number of bound states supported by the potential curve, so that the model is mass scaled, that is, it accurately describes the bound state energies for all measured isotopic combinations. Such a model enables an accurate prediction of the s-wave scattering lengths of all isotopic combinations of the RbYb system. The reduced mass range is broad enough to cover the full scattering lengths range from $-\\infty$ to $+\\infty$. For example, the $^{87}$Rb$^{174}$Yb system is characterized by a large positive scattering length of $+880(120)$~a.u., while $^{87}$Rb$^{173}$Yb has $a=-626(88)$~a.u.. On the other hand $^{87}$Rb$^{170}$Yb has a ...

  19. Immune Response of Calves Vaccinated with Brucella abortus S19 or RB51 and Revaccinated with RB51

    Science.gov (United States)

    Dorneles, Elaine M. S.; Lima, Graciela K.; Teixeira-Carvalho, Andréa; Araújo, Márcio S. S.; Martins-Filho, Olindo A.; Sriranganathan, Nammalwar; Al Qublan, Hamzeh; Heinemann, Marcos B.; Lage, Andrey P.

    2015-01-01

    Brucella abortus S19 and RB51 strains have been successfully used to control bovine brucellosis worldwide; however, currently, most of our understanding of the protective immune response induced by vaccination comes from studies in mice. The aim of this study was to characterize and compare the immune responses induced in cattle prime-immunized with B. abortus S19 or RB51 and revaccinated with RB51. Female calves, aged 4 to 8 months, were vaccinated with either vaccine S19 (0.6–1.2 x 1011 CFU) or RB51 (1.3 x 1010 CFU) on day 0, and revaccinated with RB51 (1.3 x 1010 CFU) on day 365 of the experiment. Characterization of the immune response was performed using serum and peripheral blood mononuclear cells. Blood samples were collected on days 0, 28, 210, 365, 393 and 575 post-immunization. Results showed that S19 and RB51 vaccination induced an immune response characterized by proliferation of CD4+ and CD8+ T-cells; IFN-ɣ and IL-17A production by CD4+ T-cells; cytotoxic CD8+ T-cells; IL-6 secretion; CD4+ and CD8+ memory cells; antibodies of IgG1 class; and expression of the phenotypes of activation in T-cells. However, the immune response stimulated by S19 compared to RB51 showed higher persistency of IFN-ɣ and CD4+ memory cells, induction of CD21+ memory cells and higher secretion of IL-6. After RB51 revaccination, the immune response was chiefly characterized by increase in IFN-ɣ expression, proliferation of antigen-specific CD4+ and CD8+ T-cells, cytotoxic CD8+ T-cells and decrease of IL-6 production in both groups. Nevertheless, a different polarization of the immune response, CD4+- or CD8+-dominant, was observed after the booster with RB51 for S19 and RB51 prime-vaccinated animals, respectively. Our results indicate that after prime vaccination both vaccine strains induce a strong and complex Th1 immune response, although after RB51 revaccination the differences between immune profiles induced by prime-vaccination become accentuated. PMID:26352261

  20. Immune Response of Calves Vaccinated with Brucella abortus S19 or RB51 and Revaccinated with RB51.

    Science.gov (United States)

    Dorneles, Elaine M S; Lima, Graciela K; Teixeira-Carvalho, Andréa; Araújo, Márcio S S; Martins-Filho, Olindo A; Sriranganathan, Nammalwar; Al Qublan, Hamzeh; Heinemann, Marcos B; Lage, Andrey P

    2015-01-01

    Brucella abortus S19 and RB51 strains have been successfully used to control bovine brucellosis worldwide; however, currently, most of our understanding of the protective immune response induced by vaccination comes from studies in mice. The aim of this study was to characterize and compare the immune responses induced in cattle prime-immunized with B. abortus S19 or RB51 and revaccinated with RB51. Female calves, aged 4 to 8 months, were vaccinated with either vaccine S19 (0.6-1.2 x 1011 CFU) or RB51 (1.3 x 1010 CFU) on day 0, and revaccinated with RB51 (1.3 x 1010 CFU) on day 365 of the experiment. Characterization of the immune response was performed using serum and peripheral blood mononuclear cells. Blood samples were collected on days 0, 28, 210, 365, 393 and 575 post-immunization. Results showed that S19 and RB51 vaccination induced an immune response characterized by proliferation of CD4+ and CD8+ T-cells; IFN-ɣ and IL-17A production by CD4+ T-cells; cytotoxic CD8+ T-cells; IL-6 secretion; CD4+ and CD8+ memory cells; antibodies of IgG1 class; and expression of the phenotypes of activation in T-cells. However, the immune response stimulated by S19 compared to RB51 showed higher persistency of IFN-ɣ and CD4+ memory cells, induction of CD21+ memory cells and higher secretion of IL-6. After RB51 revaccination, the immune response was chiefly characterized by increase in IFN-ɣ expression, proliferation of antigen-specific CD4+ and CD8+ T-cells, cytotoxic CD8+ T-cells and decrease of IL-6 production in both groups. Nevertheless, a different polarization of the immune response, CD4+- or CD8+-dominant, was observed after the booster with RB51 for S19 and RB51 prime-vaccinated animals, respectively. Our results indicate that after prime vaccination both vaccine strains induce a strong and complex Th1 immune response, although after RB51 revaccination the differences between immune profiles induced by prime-vaccination become accentuated.

  1. A New Rb Lamp Exciter Circuit for Rb atomic clocks and Studies on Transition from Ring to Red mode

    CERN Document Server

    Singh, Savita; Saxena, G M

    2010-01-01

    In this paper we describe the development of novel RF exciter circuit for electrode less Rb lamp. The lamp exciter circuit is a RF oscillator with a a new configuration operating at 60 to 65 MHz frequency with 3 to 4 watt power. The Rb lamp is used in exciting the ground state hyperfine transitions in Rb atom in a glass cell placed inside a tuned microwave cavity, As the frequency of these hyperfine transitions is very stable it is used in the development of Rb atomic clock by phase locking the oven controlled crystal oscillator (OCXO) to this atomic transition frequency. The details of the Rb lamp exciter are presented in the paper.The Lamp is ideally operated in ring mode as in this mode the linewidth is narrow and there is no self reversal. However, high temperature and RF excitation power may drive the Rb lamp to red mode which gives rise to line broadening and self reversal. It is the experience that mode change from ring to red deteriorates the atomic signal strength and S/N. In this paper the reasons o...

  2. Loss of heterozygosity for Rb locus and pRb immunostaining in laryngeal cancer: a clinicopathologic, molecular and immunohistochemical study.

    Directory of Open Access Journals (Sweden)

    Andrzej Borzecki

    2009-01-01

    Full Text Available Several risk factors for the development of laryngeal cancer have been identified, such as smoking and alcohol consumption, but the molecular mechanisms related to the carcinogenesis in the larynx remain under investigation. In this context, deregulations of the cell-cycle-controling mechanisms, Rb-pathway in particular, have been suggested to be involved in the pathogenesis of laryngeal carcinoma. Our purpose was to investigate 13q14 LOH and the expression of Rb protein and their possible prognostic value in laryngeal cancer. The group of 67 patients with laryngeal cancer, surgically treated with minimum 5 years observation, was multi-variously analysed. LOH for Rb was investigated by PCR-based techniques using two microsatellite markers, D13S263 and D13S126, flanking the Rb locus. Amplification products from each polymorphism were fractionated by denaturing gel electrophoresis and detected by audioradiography. Immunohistochemical staining of paraffin specimens of laryngeal cancers was supervised by the use of monoclonal mouse antibodies IgG1 (Anti-Human Retinoblastoma Gene Product of Dako in dilution of 1:50. Inactivation of Rb protein was assumed to represent the expression in < or =10% tumour cells. The results of each examined individual factor were compared with clinicopathologic features and the results were statistically transformed (Chi-square test with Yates' correction, Mann-Whitney test. The Kaplan and Meier model was used for overall and disease free survival curves. Only p value of less than 0,05 was considered significant. 13q14 LOH was detected in 7/67 (10,4% of informative tumours. No correlations were found between Rb genetic alteration (LOH and gender, age, TNM staging, histological differentiation, nodal and local recurrences (p>0.05. There was a strong association between the loss of Rb and supraglottic localisation of tumour in the larynx (p<0.01. By univariate analysis 13q14 LOH proved to be significantly related to the

  3. Overlapping and distinct pRb pathways in the mammalian auditory and vestibular organs.

    Science.gov (United States)

    Huang, Mingqian; Sage, Cyrille; Tang, Yong; Lee, Sang Goo; Petrillo, Marco; Hinds, Philip W; Chen, Zheng-Yi

    2011-01-15

    Retinoblastoma gene (Rb1) is required for proper cell cycle exit in the developing mouse inner ear and its deletion in the embryo leads to proliferation of sensory progenitor cells that differentiate into hair cells and supporting cells. In a conditional hair cell Rb1 knockout mouse, Pou4f3-Cre-pRb(-/-), pRb(-/-) utricular hair cells differentiate and survive into adulthood whereas differentiation and survival of pRb(-/-) cochlear hair cells are impaired. To comprehensively survey the pRb pathway in the mammalian inner ear, we performed microarray analysis of (pRb(-/-) cochlea and utricle. The comparative analysis shows that the core pathway shared between pRb(-/-) cochlea and utricle is centered on E2F, the key pathway that mediates pRb function. A majority of differentially expressed genes and enriched pathways are not shared but uniquely associated with pRb(-/-) cochlea or utricle. In pRb(-/-) cochlea, pathways involved in early inner ear development such as Wnt/β-catenin and Notch were enriched, whereas pathways involving in proliferation and survival are enriched in pRb(-/-) utricle. Clustering analysis showed that the pRb(-/-) inner ear has characteristics of a younger control inner ear, an indication of delayed differentiation. We created a transgenic mouse model (ER-Cre-pRb(flox/flox)) in which Rb1 can be acutely deleted postnatally. Acute Rb1 deletion in the adult mouse fails to induce proliferation or cell death in inner ear, strongly indicating that Rb1 loss in these postmitotic tissues can be effectively compensated for, or that pRb-mediated changes in the postmitotic compartment result in events that are functionally irreversible once enacted. This study thus supports the concept that pRb-regulated pathways relevant to hair cell development, encompassing proliferation, differentiation and survival, act predominantly during early development.

  4. SUSY effects in Rb: Revisited under current experimental constraints

    Science.gov (United States)

    Su, Wei; Yang, Jin Min

    2016-06-01

    In this note we revisit the SUSY effects in Rb under current experimental constraints including the LHC Higgs data, the B-physics measurements, the dark matter relic density and direct detection limits, as well as the precision electroweak data. We first perform a scan to figure out the currently allowed parameter space and then display the SUSY effects in Rb. We find that although the SUSY parameter space has been severely restrained by current experimental data, both the general MSSM and the natural-SUSY scenario can still alter Rb with a magnitude sizable enough to be observed at future Z-factories (ILC, CEPC, FCC-ee, Super Z-factory) which produce 109-1012Z-bosons. To be specific, assuming a precise measurement δRb = 2.0 ×10-5 at FCC-ee, we can probe a right-handed stop up to 530 GeV through chargino-stop loops, probe a sbottom to 850 GeV through neutralino-sbottom loops and a charged Higgs to 770 GeV through the Higgs-top quark loops for a large tan ⁡ β. The full one-loop SUSY correction to Rb can reach 1 ×10-4 in natural SUSY and 2 ×10-4 in the general MSSM.

  5. Spectroscopy of ultracold LiRb molecules using ionization detection

    Science.gov (United States)

    Altaf, Adeel

    We present spectroscopic studies of ultracold LiRb molecules using ionization detection. The molecules are created by cooling and trapping Li and Rb atoms in overlapping magneto-optical traps (MOTs) and using light resonant with a free-bound transition to create weakly bound excited state molecules in a process known as photoassociation (PA). We explore weakly bound vibrational levels of LiRb with PA spectroscopy using ionization detection and, where possible, compare our results with earlier measurements performed in our lab using trap-loss spectroscopy. In addition, we also probe vibrational levels of the ground triplet electronic state and excited electronic states using resonantly enhanced multiphoton ionization (REMPI) spectroscopy. We identify several vibrational levels of the alpha3Sigma+, (3)3piO and (4)3Sigma + states and compare our observations with theoretical calculations. As LiRb is one of the least studied heteronuclear diatomic molecules, these studies are aimed towards exploring the molecular structure. The spectroscopic work is also in line with the long-term project goals of transferring ultracold LiRb molecules into the lowest rotational and vibrational levels of the ground singlet electronic state. Molecules in this rovibronic ground state possess a large electric dipole moment, which is essential for application of ultracold molecules in various quantum computation schemes. The rovibronic ground state will also be an ideal starting point for investigating molecular entangled states.

  6. Ginsenoside Rb1 attenuates activated microglia-induced neuronal damage

    Institute of Scientific and Technical Information of China (English)

    Lining Ke; Wei Guo; Jianwen Xu; Guodong Zhang; Wei Wang; Wenhua Huang

    2014-01-01

    The microglia-mediated inlfammatory reaction promotes neuronal damage under cerebral isch-emia/hypoxia conditions. We therefore speculated that inhibition of hypoxia-induced microglial activation may alleviate neuronal damage. To test this hypothesis, we co-cultured ginsenoside Rb1, an active component of ginseng, and cortical neurons. Ginsenoside Rb1 protected neuronal morphology and structure in a single hypoxic culture system and in a hypoxic co-culture system with microglia, and reduced neuronal apoptosis and caspase-3 production. The protective effect was observable prior to placing in co-culture. Additionally, ginsenoside Rb1 inhibited levels of tumor necrosis factor-αin a co-culture system containing activated N9 microglial cells. Ginse-noside Rb1 also signiifcantly decreased nitric oxide and superoxide production induced by N9 microglia. Our ifndings indicate that ginsenoside Rb1 attenuates damage to cerebral cortex neu-rons by downregulation of nitric oxide, superoxide, and tumor necrosis factor-αexpression in hypoxia-activated microglia.

  7. Low-frequency excitations in Rb{sub 3}C{sub 60} and Rb{sub 6}C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Schober, H. [Institut Max von Laue - Paul Langevin, 38 - Grenoble (France); Renker, B. [INFP, Forschungszentrum Karlsruhe, D-76021 Karlsruhe (Germany); Gompf, F. [INFP, Forschungszentrum Karlsruhe, D-76021 Karlsruhe (Germany)

    1996-04-01

    We present inelastic neutron scattering results for Rb{sub 3}C{sub 60} and Rb{sub 6}C{sub 60} covering the energy region from 0.5 to 14 meV. The different contributions to the spectra (translational, libronic, Rb-vibrations) are discussed on the basis of their Q and temperature dependence. In superconducting Rb{sub 3}C{sub 60} the scattering intensity observed in the range from 1.5 to 3.5 meV changes anomalously with temperature. No such behaviour is found in insulating Rb{sub 6}C{sub 60}. (orig.).

  8. Development of the new RB26DETT engine. Shingata RB26DETT engine no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Ura, S.; Nakamura, K.; Fujita, H.; Eto, T.; Yamanaka, J. (Nissan Motor Co. Ltd., Tokyo (Japan))

    1989-12-25

    This paper introduces the RB26DETT engine which was developed by Nissan Motor Co., Ltd., for use in the new high-performance Skyline GT-R sports coupe. This is 2.6 liter DOHC twin-turbo engine developed for the aim to built the world {prime} s best mass-produced in-line 6-cylinder engine by integrating the most advanced techniques. It features the adaptation of twin ceramic turbochargers which vastly reduce the interference between exhaust gas flows, and the equipment of large-capacity air-cooled intercooler system which greatly improves the cooling capacity. Other features include the applying of six throttle butterflies for improved intake air response during acceleration and a lighter weight valvetrain. As the result, high output, excellent throttle response and an impressive rotation speed were attained and world-top-class performance surpassing that of sports car engines was obtained. 14 figs., 3 tabs.

  9. Detection of Tumor Suppressor Gene and Oncogene in SO-Rb_(50) Human Retinoblastoma Cell Line

    Institute of Scientific and Technical Information of China (English)

    1993-01-01

    Retinoblastoma (Rb) is the most common malignant'cancer of eye. So-Rb_(50) is the first Rb cell line established in China in 1988. It has passed to the 387th passage now. We collected cells of the 327th passage of SO-Rb_(50), purified its genomic DNA and detected it with Rb and c-myc cDNA probes respectively (normal human white blood cells DNA was the control). We found the Rb gene was deleted while c-myc gene was amplified three times. This provides a basis for further study of the regulation of tumor ...

  10. Diffusion of Rb atoms in paraffin - coated resonant vapor cells

    CERN Document Server

    Atutov, S N; Plekhanov, A I; Sorokin, V A; Yakovlev, A V

    2016-01-01

    We present the results of a study of the diffusion of Rb atoms in paraffin - coated resonant vapor cells. We have modeled the Rb diffusion both in the cell and in the coating, assuming that the main loss of Rb atoms is due to the physical absorption of the atoms by the glass substrate. It is demonstrated that the equilibrium atomic density in the cell is a monotonic function of the thickness of the paraffin coating: the density increases with an increase in the thickness of the coating. The diffusion coefficient for rubidium in paraffin thin films has been determined to be equal to 4,7*10^-7 cm^2/s. The results of the experiment might be useful for a better understanding of the details involved in the processes of the interaction of alkali atoms with a paraffin coating.

  11. \\textit{Ab initio} study of reactive collisions between Rb($^{2}S$) or Rb($^{2}P$) and OH$^{-}$($^{1}\\Sigma^{+}$)

    CERN Document Server

    Kas, Milaim; Liévin, Jacques; Vaeck, Nathalie

    2016-01-01

    A theoretical rate constant for the associative detachment reaction Rb($^{2}S$)$+$OH$^{-}$($^{1}\\Sigma^{+}$)$\\rightarrow \\,$ RbOH($^{1}\\Sigma^{+}$)$+\\,e^{-}$ of 4$\\,\\times$10$^{-10}$cm$^{3}$s$^{-1}$ at 300 K has been calculated. This result agrees with the experimental rate constant of 2$^{+2}_{-1}\\,\\times10^{-10}$cm$^{3}$s$^{-1}$ obtained by Deiglmayr \\textit{et al.} (Phys. Rev. A 86, 2012) for a temperature between 200 K and 600 K. A Langevin-based dynamics which depends on the crossing point between the anion (RbOH$^{-}$) and neutral (RbOH) potential energy surfaces has been used. The calculation were performed using the ECP28MDF effective core potential to describe the rubidium atom at the CCSD(T) level of theory and extended basis sets. The effect of ECPs and basis set on the height of the crossing point, and hence the rate constant, has been investigated. The temperature dependence of the latter is also discussed. Preliminary work on the potential energy surface for the excited reaction channel Rb($^{2}...

  12. Number-Theory in Nuclear-Physics in Number-Theory: Non-Primality Factorization As Fission VS. Primality As Fusion; Composites' Islands of INstability: Feshbach-Resonances?

    Science.gov (United States)

    Smith, A.; Siegel, Edward Carl-Ludwig

    2011-03-01

    Numbers: primality/indivisibility/non-factorization versus compositeness/divisibility/ factorization, often in tandem but not always, provocatively close analogy to nuclear-physics: (2 + 1)=(fusion)=3; (3+1)=(fission)=4[=2 x 2]; (4+1)=(fusion)=5; (5 +1)=(fission)=6[=2 x 3]; (6 + 1)=(fusion)=7; (7+1)=(fission)=8[= 2 x 4 = 2 x 2 x 2]; (8 + 1) =(non: fission nor fusion)= 9[=3 x 3]; then ONLY composites' Islands of fusion-INstability: 8, 9, 10; then 14, 15, 16, ... Could inter-digit Feshbach-resonances exist??? Possible applications to: quantum-information/ computing non-Shore factorization, millennium-problem Riemann-hypotheses proof as Goodkin BEC intersection with graph-theory "short-cut" method: Rayleigh(1870)-Polya(1922)-"Anderson"(1958)-localization, Goldbach-conjecture, financial auditing/accounting as quantum-statistical-physics; ...abound!!! Watkins [www.secamlocal.ex.ac.uk/people/staff/mrwatkin/] "Number-Theory in Physics" many interconnections: "pure"-maths number-theory to physics including Siegel [AMS Joint Mtg.(2002)-Abs.# 973-60-124] inversion of statistics on-average digits' Newcomb(1881)-Weyl(14-16)-Benford(38)-law to reveal both the quantum and BEQS (digits = bosons = digits:"spinEless-boZos"). 1881 1885 1901 1905 1925 < 1927, altering quantum-theory history!!!

  13. A Measurement of $R_b$ using Mutually Exclusive Tags

    CERN Document Server

    Barate, R; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; Pietrzyk, B; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Delfino, M C; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Miquel, R; Mir, L M; Orteu, S; Padilla, C; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Alemany, R; Becker, U; Bazarko, A O; Bright-Thomas, P G; Cattaneo, M; Cerutti, F; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Lutters, G; Mato, P; Minten, Adolf G; Moneta, L; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rizzo, G; Rolandi, Luigi; Schlatter, W D; Schmitt, M; Schneider, O; Tejessy, W; Tomalin, I R; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Casper, David William; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, E; Thomson, F; Turnbull, R M; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Schmidt, M; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Moutoussi, A; Nash, J; Sedgbeer, J K; Stacey, A M; Williams, M D; Dissertori, G; Ghete, V M; Girtler, P; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Williams, M I; Galla, A; Giehl, I; Greene, A M; Hoffmann, C; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Coyle, P; Diaconu, C A; Etienne, F; Konstantinidis, N P; Leroy, O; Motsch, F; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Ragusa, F; Berlich, R; Blum, Walter; Brown, D; Büscher, V; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Stenzel, H; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Chen, S; Choi, Y; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Schune, M H; Simion, S; Tournefier, E; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Venturi, A; Verdini, P G; Blair, G A; Bryant, L M; Chambers, J T; Gao, Y; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Kelly, M S; Lehto, M H; Newton, W M; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Grupen, Claus; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Charles, E; Elmer, P; Ferguson, D P S; Gao, Y S; González, S; Greening, T C; Hayes, O J; Hu, H; Jin, S; McNamara, P A; Nachtman, J M; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Wu Sau Lan; Wu, X; Yamartino, J M; Zobernig, G

    1997-01-01

    A measurement of $R_b$ using five mutually exclusive hemisphere tags has been pe rformed by ALEPH using the full LEP1 statistics. Three tags are designed to sele ct the decay of the $Z^0$ to $b$ quarks, while the remaining two select $Z^0$ decays to $c$ and light quarks, and are used to measure the tagging efficiencies. The result, {$R_b~=~0.2159~\\pm~0.0009\\mbox{(stat)}~\\pm 0.0011\\mbox{(syst)}$}, is in agreement with the electroweak theory prediction of $0.2158 \\pm 0.0003$.

  14. Measurement of $R_{b}$ using a Vertex Mass Tag

    CERN Document Server

    Abe, K; Akagi, T; Allen, N J; Ash, W W; Aston, D; Baird, K G; Baltay, C; Band, H R; Barakat, M B; Baranko, G; Bardon, O; Barklow, T L; Bashindzhagian, G L; Bazarko, A O; Ben-David, R; Benvenuti, Alberto C; Bilei, G M; Bisello, D; Blaylock, G; Bogart, J R; Bolen, B; Bolton, T; Bower, G R; Brau, J E; Breidenbach, M; Bugg, W M; Burke, D; Burnett, T H; Burrows, P N; Busza, W; Calcaterra, A; Caldwell, D O; Calloway, D; Camanzi, B; Carpinelli, M; Cassell, R; Castaldi, R; Castro, A; Cavalli-Sforza, M; Chou, A; Church, E; Cohn, H O; Coller, J A; Cook, V; Cotton, R; Cowan, R F; Coyne, D G; Crawford, G; de Oliveira, A; Damerell, C J S; Daoudi, M; De Groot, N; De Sangro, R; Dell'Orso, R; Dervan, P J; Dima, M; Dong, D N; Du, P Y C; Dubois, R; Eisenstein, B I; Elia, R; Etzion, E; Fahey, S; Falciai, D; Fan, C; Fernández, J P; Fero, M J; Frey, R; Gillman, T; Gladding, G; González, S; Hart, E L; Harton, J L; Hasan, A; Hasegawa, Y; Hasuko, K; Hedges, S J; Hertzbach, S S; Hildreth, M D; Huber, J; Huffer, M E; Hughes, E W; Hwang, H; Iwasaki, Y; Jackson, D J; Jacques, P; Jaros, J A; Jiang, Z Y; Johnson, A S; Johnson, J R; Johnson, R A; Junk, T R; Kajikawa, R; Kalelkar, M; Kang, H J; Karliner, I; Kawahara, H; Kendall, H W; Kim, Y D; King, M E; King, R; Kofler, R R; Krishna, N M; Kroeger, R S; Labs, J F; Langston, M; Lath, A; Lauber, J A; Leith, D W G S; Lia, V; Liu, M X; Liu, X; Loreti, M; Lu, A; Lynch, H L; Ma, J; Mancinelli, G; Manly, S; Mantovani, G C; Markiewicz, T W; Maruyama, T; Masuda, H; Mazzucato, E; McKemey, A K; Meadows, B T; Messner, R; Mockett, P M; Moffeit, K C; Moore, T B; Müller, D; Nagamine, T; Narita, S; Nauenberg, U; Neal, H; Nussbaum, M; Ohnishi, Y; Oishi, N; Onoprienko, D; Osborne, L S; Panvini, R S; Park, C H; Park, H; Pavel, T J; Peruzzi, I; Piccolo, M; Piemontese, L; Pieroni, E; Pitts, K T; Plano, R J; Prepost, R; Prescott, C Y; Punkar, G D; Quigley, J; Ratcliff, B N; Reeves, T W; Reidy, J; Reinertsen, P L; Rensing, P E; Rochester, L S; Rowson, P C; Russell, J J; Saxton, O H; Schalk, T; Schindler, R H; Schumm, B A; Schwiening, J; Sen, S; Serbo, V V; Shaevitz, M H; Shank, J T; Shapiro, G; Sherden, D J; Shmakov, K D; Simopoulos, C; Sinev, N B; Smith, S R; Smy, M B; Snyder, J A; Stängle, H; Stamer, P; Steiner, H; Steiner, R; Strauss, M G; Su, D; Suekane, F; Sugiyama, A; Suzuki, S; Swartz, M; Szumilo, A; Takahashi, T; Taylor, F E; Torrence, E; Trandafir, A I; Turk, J D; Usher, T; Vavra, J; Vannini, C; Vella, E; Venuti, J P; Verdier, R; Verdini, P G; Wagner, D L; Wagner, S R; Waite, A P; Watts, S J; Weidemann, A W; Weiss, E R; Whitaker, J S; White, S L; Wickens, F J; Williams, D C; Williams, S H; Willocq, S; Wilson, R J; Wisniewski, W J; Woods, M; Word, G B; Wyss, J; Yamamoto, R K; Yamartino, J M; Yang, X; Yashima, J; Yellin, S J; Young, C C; Yuta, H; Zapalac, G; Zdarko, R W; Zhou, J

    1998-01-01

    We report a new measurement of Rb = Gamma(Z0->b-bbar) / Gamma(Z0->hadrons) using a double tag technique, where the b hemisphere selection is based on the reconstructed mass of the B hadron decay vertex. The measurement was performed using a sample of 130k hadronic Z0 events, collected with the SLD at the SLC. The method utilizes the 3-D vertexing abilities of the CCD pixel vertex detector and the small stable SLC beams to obtain a high b-tagging efficiency and purity. We obtain Rb=0.2142+/-0.0034(stat.)+/-0.0015(syst.)+/-0.0002(R_c).

  15. Certificate Revocation System's Based on RB_Tree%基于RB_Tree的证书吊销系统

    Institute of Scientific and Technical Information of China (English)

    周海岩

    2009-01-01

    提出了公钥基础设施(Public Key Infrastructure,PKI)中证书吊销问题的一种解决方案--RB_搜索树解决方案(Certificate Revocation RB_Tree,CRRBT).该方案在查询与更新时最大时间复杂度始终保持在O(log2n)量级,对工程实现具有一定的指导意义.

  16. Genetic and bibliographic information: IL10RB [GenLibi

    Lifescience Database Archive (English)

    Full Text Available IL10RB interleukin 10 receptor, beta human Periodontitis (MeSH) Stomatognathic Dise...ases (C07) > Mouth Diseases (C07.465) > Periodontal Diseases (C07.465.714) > Periodontitis (C07.465.714.533) 02A0614091 ...

  17. Mass measurements of neutron-rich Rb and Sr isotopes

    CERN Document Server

    Klawitter, R; Brodeur, M; Chowdhury, U; Chausdhuri, A; Fallis, J; Gallant, A T; Grossheim, A; Kwiatkowski, A A; Lascar, D; Leach, K G; Lennarz, A; Macdonald, T D; Pearkes, J; Seeraji, S; Simon, M C; Simon, V V; Schultz, B E; Dilling, J

    2015-01-01

    We report on the mass measurements of several neutron-rich $\\mathrm{Rb}$ and $\\mathrm{Sr}$ isotopes in the $A \\approx 100$ region with the TITAN Penning-trap mass spectrometer. Using highly charged ions in the charge state $q=10+$, the masses of $^{98,99}\\mathrm{Rb}$ and $^{98-100}\\mathrm{Sr}$ have been determined with a precision of $6 - 12\\ \\mathrm{keV}$, making their uncertainty negligible for r-process nucleosynthesis network calculations. The mass of $^{101}\\mathrm{Sr}$ has been determined directly for the first time with a precision eight times higher than the previous indirect measurement and a deviation of $3\\sigma$ when compared to the Atomic Mass Evaluation. We also confirm the mass of $^{100}\\mathrm{Rb}$ from a previous measurement. Furthermore, our data indicates the existance of a low-lying isomer with $80\\ \\mathrm{keV}$ excitation energy in $^{98}\\mathrm{Rb}$. We show that our updated mass values lead to minor changes in the r-process by calculating fractional abundances in the $A\\approx 100$ re...

  18. RB962962, a sugarcane cultivar for late harvest

    Directory of Open Access Journals (Sweden)

    Luiz José Oliveira Tavares de Melo

    2014-07-01

    Full Text Available In the Northeast of Brazil, sugarcane cultivar RB962962 is harvested at the end of the cycle, between December and February, with a high sugar yield per area. Recommended for sandy soils of medium texture and fertility, it is resistant to the major diseases and fast-growing in plant and ratoon crops.

  19. Dissecting Pin1 and phospho-pRb regulation.

    Science.gov (United States)

    Rizzolio, Flavio; Caligiuri, Isabella; Lucchetti, Chiara; Fratamico, Robert; Tomei, Valentina; Gallo, Gaia; Agelan, Alexis; Ferrari, Giovanni; Toffoli, Giuseppe; Klein-Szanto, Andres J; Giordano, Antonio

    2013-01-01

    The activity of the Retinoblastoma protein, the master regulator of the cell cycle, is finely regulated by phosphorylation. CDKs and cyclins are major players in phosphorylation and it has been recently discovered that the prolyl isomerase Pin1 is an essential protein that orchestrates this process. In this article, we report new findings regarding the role of Pin1 in the pRb pathway. Our data suggest that PI3K, CDKs, and the Pin1 axis have a critical role in sustaining the complete phosphorylation of pRb. Furthermore, we analyze the correlation between Pin1 and pRb phosphorylation in vivo. We show that, in human malignant glioma tissue microarrays (TMA) and in Pin1 knockout (KO) mice, there is a positive correlation between Pin1 and pRb phosphorylation. Prospectively, our findings suggest that the synergism between CDKs, Pin1, and PI3K inhibitors hold great promise for targeted pharmacological treatment of cancer patients, with the possibility of reaching high effectiveness at tolerated doses.

  20. A remotely interrogated all-optical Rb-87 magnetometer

    NARCIS (Netherlands)

    Patton, B.; Versolato, O. O.; Hovde, D. C.; Corsini, E.; Higbie, J. M.; Budker, D.

    2012-01-01

    Atomic magnetometry was performed at Earth's magnetic field over a free-space distance of ten meters. Two laser beams aimed at a distant alkali-vapor cell excited and detected the Rb-87 magnetic resonance, allowing the magnetic field within the cell to be interrogated remotely. Operated as a driven

  1. Collection of $^{83}$Rb at low implantation energy for KATRIN

    CERN Multimedia

    Zboril, M

    KATRIN, the KArlsruhe TRItium Neutrino experiment aims to measure the neutrino mass by spectroscopy of the tritium $\\beta$-decay at the endpoint by means of Magnetic Adiabatic Collimation combined with an Electrostatic filter (MAC-E filter). To monitor the HV-system of the KATRIN-setup, we would need one or two $^{83}$Rb sources roughly every half a year.

  2. Frequent disruption of the RB1 pathway in diffuse large B cell lymphoma

    DEFF Research Database (Denmark)

    Møller, M B; Kania, Per Walter; Ino, Y

    2000-01-01

    In the present study, we analysed 34 de novo diffuse large B cell lymphoma (DLCL) from a population-based lymphoma registry for alterations of the RB1 pathway at the genetic (RB1 and CDK4) and protein (pRb, cyclin D1, cyclin D3, CDK4, and E2F-1) level. The results were correlated with the data fr...

  3. Expression of CD45RB functionally distinguishes intestinal T lymphocytes in inflammatory bowel disease.

    NARCIS (Netherlands)

    Hove, T. ten; The Olle, F.; Berkhout, M.; Bruggeman, J.P.; Vyth-Dreese, F.A.; Slors, J.F.M.; Deventer, S.J.H. van; Velde, A.A. te

    2004-01-01

    The importance of CD45RB expression on T cells was already shown in mice where CD45RB(high) expression determines pathogenic potential. In this study, we analyzed the expression of CD45RA, CD45RB, and CD45RO on CD4(+) T lymphocytes in the intestinal mucosa and in the circulation of patients with inf

  4. Treating cancer when pRb and p53 cannot be reactivated.

    Science.gov (United States)

    Zhu, Liang

    2015-01-01

    Activation of oncoproteins and inactivation of tumor suppressors induces tumorigenesis. When these events happen upstream of pRb and p53, cancer therapies may initially succeed and then fail when pRb and p53 are activated and then re-inactivated. Therapies might succeed if they remain effective when pRb and p53 are genetically inactivated.

  5. Immune responses of bison and efficacy after booster vaccination with Brucella abortus strain RB51

    Science.gov (United States)

    Thirty-one bison heifers were randomly assigned to saline (control; n=7) or single vaccination (n=24) with 1010 CFU of B. abortus strain RB51 (RB51). Some vaccinated bison were randomly selected for booster vaccination with 10**10 CFU of RB51 at 11 months after initial vaccination (n=16). When comp...

  6. Review of accident analyses of RB experimental reactor

    Directory of Open Access Journals (Sweden)

    Pešić Milan P.

    2003-01-01

    Full Text Available The RB reactor is a uranium fuel heavy water moderated critical assembly that has been put and kept in operation by the VTNCA Institute of Nuclear Sciences, Belgrade, Serbia and Montenegro, since April 1958. The first complete Safety Analysis Report of the RB reactor was prepared in 1961/62 yet, the first accident analysis had been made in late 1958 with the aim to examine a power transition and the total equivalent doses received by the staff during the reactivity accident that occurred on October 15, 1958. Since 1960, the RB reactor has been modified a few times. Beside the initial natural uranium metal fuel rods, new types of fuel (TVR-S types of Russian origin consisting of 2% enriched uranium metal and 80% enriched UO2 dispersed in aluminum matrix, have been available since 1962 and 1976 respectively. Modifications of the control and safety systems of the reactor were made occasionally. Special reactor cores were designed and constructed using all three types of fuel elements as well as the coupled fast-thermal ones. The Nuclear Safety Committee of the VINĆA Institute, an independent regulatory body, approved for usage all these modifications of the RB reactor on the basis of the Preliminary Safety Analysis Reports, which, beside proposed technical modifications and new regulation rules, included safety analyses of various possible accidents. A special attention was given (and a new safety methodology was proposed to thorough analyses of the design-based accidents related to the coupled fast-thermal cores that included central zones of the reactor filled by the fuel elements without any moderator. In this paper, an overview of some accidents, methodologies and computation tools used for the accident analyses of the RB reactor is given.

  7. First-principles calculations of two cubic fluoropervskite compounds: RbFeF3 and RbNiF3

    Science.gov (United States)

    Mubarak, A. A.; Al-Omari, Saleh

    2015-05-01

    We present first-principles calculations of the structural, elastic, electronic, magnetic and optical properties for RbFeF3 and RbNiF3. The full-potential linear augmented plan wave (FP-LAPW) method within the density functional theory was utilized to perform the present calculations. We employed the generalized gradient approximation as exchange-correlation potential. It was found that the calculated analytical lattice parameters agree with previous studies. The analysis of elastic constants showed that the present compounds are elastically stable and anisotropic. Moreover, both compounds are classified as a ductile compound. The calculations of the band structure and density functional theory revealed that the RbFeF3 compound has a half-metallic behavior while the RbNiF3 compound has a semiconductor behavior with indirect (M-Γ) band gap. The ferromagnetic behavior was studied for both compounds. The optical properties were calculated for the radiation of up to 40 eV. A beneficial optics technology is predicted as revealed from the optical spectra.

  8. 75 FR 33738 - Airworthiness Directives; Rolls-Royce plc (RR) RB211-524 Series and RB211 Trent 500, 700, and 800...

    Science.gov (United States)

    2010-06-15

    ... plc (RR) RB211-524 Series and RB211 Trent 500, 700, and 800 Series Turbofan Engines AGENCY: Federal... holidays. Fax: (202) 493-2251. Contact Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone... Information Rolls-Royce plc has issued Alert Service Bulletin RB.211-72-AF964, Revision 1, dated June 6,...

  9. Deletion of Rb1 induces both hyperproliferation and cell death in murine germinal center B cells.

    Science.gov (United States)

    He, Zhiwen; O'Neal, Julie; Wilson, William C; Mahajan, Nitin; Luo, Jun; Wang, Yinan; Su, Mack Y; Lu, Lan; Skeath, James B; Bhattacharya, Deepta; Tomasson, Michael H

    2016-03-01

    The retinoblastoma gene (RB1) has been implicated as a tumor suppressor in multiple myeloma (MM), yet its role remains unclear because in the majority of cases with 13q14 deletions, un-mutated RB1 remains expressed from the retained allele. To explore the role of Rb1 in MM, we examined the functional consequences of single- and double-copy Rb1 loss in germinal center B cells, the cells of origin of MM. We generated mice without Rb1 function in germinal center B cells by crossing Rb1(Flox/Flox) with C-γ-1-Cre (Cγ1) mice expressing the Cre recombinase in class-switched B cells in a p107(-/-) background to prevent p107 from compensating for Rb1 loss (Cγ1-Rb1(F/F)-p107(-/-)). All mice developed normally, but B cells with two copies of Rb1 deleted (Cγ1-Rb1(F/F)-p107(-/-)) exhibited increased proliferation and cell death compared with Cγ1-Rb1(+/+)-p107(-/-) controls ex vivo. In vivo, Cγ1-Rb1(F/F)-p107(-/-) mice had a lower percentage of splenic B220+ cells and reduced numbers of bone marrow antigen-specific secreting cells compared with control mice. Our data indicate that Rb1 loss induces both cell proliferation and death in germinal center B cells. Because no B-cell malignancies developed after 1 year of observation, our data also suggest that Rb1 loss is not sufficient to transform post-germinal center B cells and that additional, specific mutations are likely required to cooperate with Rb1 loss to induce malignant transformation.

  10. Observation of Serum Bactericidal Activity of Brucella abortus RB51 OMPs Combined with Brucella abortus RB51 Live Vaccine

    Directory of Open Access Journals (Sweden)

    Fahime Gholizadeh

    2013-06-01

    Full Text Available Background & objectives: vaccination is vital against brucellosis. Although current vaccines have low efficiency, some cell wall compartments such as Outer Membrane Proteins could be used as an immunogenic candidate in vaccine development. By this mean, our aim in this study was to evaluate the humoral immunity of the combination of Brucella abortus RB51 OMPs with the Brucella abortus RB51 live attenuated vaccine, by Serum Bactericidal Acitivity test. Materials and Methods: In this project, first Brucella abortus RB51 was cultivated in brucella agar. The OMPs were extracted by Sodium N-Lauryl Sarcosinate method, then added to the RB51 live attenuated vaccine. Immunization was done by injection of the vaccine to mice and rabbits. The blood was drawn on days 0, 15,30, and 45 from the rabbits and the sera were seperated. Brucella abortus 544 was also injected as challenge. Spleen colony count was also performed. Results: The data from Serum Bactericidal Assay has showed, there was a very high Humoral immunity and response as a bactericidal titre of the serum against Rb51 Live vaccine. There was a significant decrease of colonies in the group vaccinated with the combined vaccine in the Spleen colony count test. Statistical analysis of groups variances showed a significant difference between groups (P<0.05.Conclusions: The Serum Bactericidal Assay results showed despite previous studies, both the combine and live vaccine are capable to stimulate the Humoral immunity. greater activity of combined vaccine to boost the humoral activity might be due to the synergistic effect of this vaccine.

  11. Electric field cancellation on quartz: a Rb adsorbate induced negative electron affinity surface

    CERN Document Server

    Sedlacek, J A; Rittenhouse, S T; Weck, P F; Sadeghpour, H R; Shaffer, J P

    2015-01-01

    We investigate the (0001) surface of single crystal quartz with a submonolayer of Rb adsorbates. Using Rydberg atom electromagnetically induced transparency, we investigate the electric fields resulting from Rb adsorbed on the quartz surface, and measure the activation energy of the Rb adsorbates. We show that the adsorbed Rb induces a negative electron affinity (NEA) on the quartz surface. The NEA surface allows low energy electrons to bind to the surface and cancel the electric field from the Rb adsorbates. Our results are important for integrating Rydberg atoms into hybrid quantum systems and the fundamental study of atom-surface interactions, as well as applications for electrons bound to a 2D surface.

  12. Rubidium isotope effect in superconducting Rb[sub 3]C[sub 60

    Energy Technology Data Exchange (ETDEWEB)

    Burk, B.; Crespi, V.H.; Zettl, A.; Cohen, M.L. (Department of Physics, University of California at Berkeley, Berkeley, California 94720 (United States) Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States))

    1994-06-06

    We have measured the resistive supercondeucting transition temperature in C[sub 60] single crystals intercalated with isotopically pure [sup 87]Rb and [sup 85]Rb and with natural abundance rubidium. We obtain a rubidium isotope effect exponent of [alpha][sub Rb]=[minus]0.028[plus minus]0.036, a result which implies that the Rb-C[sub 60] optic phonons play at most a minor role in the pairing mechanism of Rb[sub 3]C[sub 60].

  13. Ternary K2Zn5As4-type pnictides Rb2Cd5As4 and Rb2Zn5Sb4, and the solid solution Rb2Cd5(As,Sb)4.

    Science.gov (United States)

    He, Hua; Stoyko, Stanislav S; Mar, Arthur; Bobev, Svilen

    2013-05-01

    Dirubidium pentacadmium tetraarsenide, Rb2Cd5As4, dirubidium pentazinc tetraantimonide, Rb2Zn5Sb4, and the solid-solution phase dirubidium pentacadmium tetra(arsenide/antimonide), Rb2Cd5(As,Sb)4 [or Rb2Cd5As3.00(1)Sb1.00(1)], have been prepared by direct reaction of the component elements at high temperature. These compounds are charge-balanced Zintl phases and adopt the orthorhombic K2Zn5As4-type structure (Pearson symbol oC44), featuring a three-dimensional [M5Pn4](2-) framework [M = Zn or Cd; Pn is a pnicogen or Group 15 (Group V) element] built of linked MPn4 tetrahedra, and large channels extending along the b axis which host Rb(+) cations. The As and Sb atoms in Rb2Cd5(As,Sb)4 are randomly disordered over the two available pnicogen sites. Band-structure calculations predict that Rb2Cd5As4 is a small-band-gap semiconductor and Rb2Zn5Sb4 is a semimetal.

  14. Spin exchange collision mixing of the K and Rb ac Stark shifts

    CERN Document Server

    Chen, Yao; Fang, Jiancheng

    2016-01-01

    In a hybrid pumping alkali vapor cell that both K and Rb are filled, K atom spins are optically pumped by laser and Rb atom spins are polarized by the K spins through spin exchange. We find that the AC Stark shift of the Rb atoms is composed of not only the AC Stark shift of the Rb atoms caused by the far off resonant pumping laser which is tuned to the K absorption lines, but also the AC Stark shift of the K atom spins. The mixing of the light shifts through fast spin exchange between K and Rb atoms are studied in this paper and we demonstrate a K-Rb-21Ne co-magnetometer in which the AC Stark shift of the Rb atoms are reduced by the collision mixing.

  15. Desorption Dynamics of Rb_2 Molecules off the Surface of Helium Nanodroplets

    CERN Document Server

    Sieg, A; Stienkemeier, F; Dulieu, O; Mudrich, M

    2016-01-01

    The desorption dynamics of rubidium dimers (Rb_2) off the surface of helium nanodroplets induced by laser excitation is studied employing both nanosecond and femtosecond ion imaging spectroscopy. Similarly to alkali metal atoms, we find that the Rb_2 desorption process resembles the dissociation of a diatomic molecule. However, both angular and energy distributions of detected Rb_2^+ ions appear to be most crucially determined by the Rb_2 intramolecular degrees of freedom rather than by those of the Rb_2He_N complex. The pump-probe dynamics of Rb_2^+ is found to be slower than that of Rb^+ pointing at a weaker effective guest-host repulsion for excited molecules than for single atoms.

  16. Frequency Stability of Atomic Clocks Based on Coherent Population Trapping Resonance in 85Rb

    Institute of Scientific and Technical Information of China (English)

    LIU Lu; GUO Tao; DENG Ke; LIU Xin-Yuan; CHEN Xu-Zong; WANG Zhong

    2007-01-01

    An atomic clock system based on coherent population trapping (CPT) resonance in 85Rb is reported, while most past works about the CPT clock are in 87Rb. A new modulation method (full-hyperfine-frequency-splitting modulation) is presented to reduce the effect of light shift to improve the frequency stability of the CPT clock in 85Rb. The experimental results show that the short-term frequency stability of the CPT clock in 85Rb is in the order of 10-10/s and the long-term frequency stability can achieve 1.5 × 10-11 /80000s, which performs as well as 87Rb in CPT resonance. This very good frequency stability performance associated with the low-cost and low-power properties of 85Rb indicates that an atomic clock based on CPT in 85 Rb should be a promising candidate for making the chip scale atomic clock.

  17. A subset of malignant phyllodes tumors harbors alterations in the Rb/p16 pathway.

    Science.gov (United States)

    Cimino-Mathews, Ashley; Hicks, Jessica L; Sharma, Rajni; Vang, Russell; Illei, Peter B; De Marzo, Angelo; Emens, Leisha A; Argani, Pedram

    2013-11-01

    Breast phyllodes tumors are fibroepithelial neoplasms with variable risk of aggressive local recurrence and distant metastasis, and the molecular pathogenesis is unclear. Here, we systematically study p16 and Rb expression in 34 phyllodes tumors in relation to proliferation. Tissue microarrays were constructed from 10 benign, 10 borderline, and 14 malignant phyllodes (5 cores/tumor) and from 10 fibroadenomas (2 cores/tumor). Tissue microarrays were labeled by immunohistochemistry for p16, Rb, and Ki-67 and by in situ hybridization for high-risk human papillomavirus. Cytoplasmic and nuclear p16 were scored by percentage labeling (0%-100%, diffuse >95%) and intensity. Nuclear Rb was scored by percentage labeling (0%-100%, diffuse >75%) and intensity. p16 and Rb labeling were repeated on whole sections of cases with Rb loss on the tissue microarray. Twenty-nine percent (4/14) malignant phyllodes showed diffuse strong p16 labeling with Rb loss in malignant cells (diffuse p16+/Rb-), whereas 21% (3/14) malignant phyllodes showed the reverse pattern of p16 loss with diffuse strong Rb (p16-/diffuse Rb+). Results were consistent between tissue microarrays and whole sections. No borderline phyllodes, benign phyllodes, or fibroadenoma showed diffuse p16+/Rb- or p16-/diffuse Rb+ phenotypes. No cases contained high-risk human papillomavirus. Average Ki-67 proliferation indices were 15% in malignant phyllodes, 1.7% in borderline phyllodes, 0.5% in benign phyllodes, and 0% in fibroadenoma. Ki-67 was highest in malignant phyllodes with diffuse p16+/Rb- labeling. In summary, 50% malignant phyllodes display evidence of Rb/p16 pathway alterations, likely reflecting p16 or Rb inactivation. These and other mechanisms may contribute to the increased proliferation in malignant phyllodes relative to other fibroepithelial neoplasms.

  18. Charge transfer in the cold Yb$^+$ + Rb collisions

    CERN Document Server

    Sayfutyarova, Elvira R; Yakovleva, Svetlana A; Belyaev, Andrey K

    2013-01-01

    Charge-transfer cold Yb$^+$ + Rb collision dynamics is investigated theoretically using high-level {\\it ab initio} potential energy curves, dipole moment functions and nonadiabatic coupling matrix elements. Within the scalar-relativistic approximation, the radiative transitions from the entrance $A^1\\Sigma^+$ to the ground $X^1\\Sigma^+$ state are found to be the only efficient charge-transfer pathway. The spin-orbit coupling does not open other efficient pathways, but alters the potential energy curves and the transition dipole moment for the $A-X$ pair of states. The radiative, as well as the nonradiative, charge-transfer cross sections calculated within the $10^{-3}-10$ cm$^{-1}$ collision energy range exhibit all features of the Langevin ion-atom collision regime, including a rich structure associated with centrifugal barrier tunneling (orbiting) resonances. Theoretical rate coefficients for two Yb isotopes agree well with those measured by immersing Yb$^+$ ion in an ultracold Rb ensemble in a hybrid trap....

  19. Blackbody radiation shift in ^87Rb frequency standard

    Science.gov (United States)

    Safronova, Marianna; Safronova, U. I.

    2010-03-01

    The operation of atomic clocks is generally carried out at room temperature, whereas the definition of the second refers to the clock transition in an atom at absolute zero. This implies that the clock transition frequency should be corrected in practice for the effect of finite temperature of which the leading contributor is the blackbody radiation (BBR) shift. Experimental measurements of the BBR shifts are difficult. In this work, we have calculated the blackbody radiation shift of the ground-state hyperfine microwave transition in ^87Rb using the relativistic all-order method and evaluated the accuracy of our final value. Particular care is taken to accurately account for the contributions from highly-excited states. Various Rb atomic properties, including E1, E2, and E3 ground state polarizabilities, np and nd E1 polarizabilities, and hyperfine constants are also calculated. The results are compared with experiment and other theory where available.

  20. Coulomb effects in Fermi {beta} decay of {sup 74}Rb

    Energy Technology Data Exchange (ETDEWEB)

    Oinonen, M. [CERN, EP Div., Geneva (Switzerland)

    2003-07-01

    Coulomb effects in the {beta} decay of {sup 74}Rb have been studied at ISOLDE. The observation of the non-analog feeding in the {beta} decay allows for an estimation of the Coulomb mixing parameter {delta}{sub IM}{sup 1}. The analysis of the total Coulomb correction {delta}{sub C} is still hampered by the uncertainty in the decay energy. (orig.)

  1. Rb optical resonance inside a random porous medium

    CERN Document Server

    Villalba, S; Laliotis, A; Lenci, L; Barreiro, S; Lezama, A

    2012-01-01

    We studied absorption and fluorescence of Rb atoms confined to the interstitial cavities of a random porous glass. Due to the diffusive light propagation in the porous sample, resonant light absorption is almost entirely compensated by atomic fluorescence at low atomic densities. For higher densities, radiation trapping increases the probability of non-radiative decay via atom-wall collisions. A simple connection of the fluorescence/absorption yield to the sample porosity is given.

  2. Fullerene molecule strain in RbC 60

    Science.gov (United States)

    Aksenov, V. L.; Ossipyan, Yu. À.; Forro, L.; Khasanov, S.; Chernyshev, V. V.; Shakhmatov, V. S.

    2000-04-01

    Strain displacements of carbon atoms in a Ñ 60 molecule in the Pnnm phase of the RbC 60 fulleride are first determined by X-ray diffraction. The measurements show that the polymeric bond length between carbon atoms of two nearest molecules C 60 is equal to 1.69(1) Å, the rotation angle of the molecule about the polymeric direction is 47.0(3)°.

  3. Fullerene Molecule Strain in $RbC_{60}$

    CERN Document Server

    Aksenov, V L; Forró, L; Khasanov, S S; Chernyshev, V V; Shakhmatov, V S

    2000-01-01

    Strain displacements of carbon atoms in a C$_60$ molecule in the $Pnnm$ phase of the RbC$_60$ fulleride are first determined by X-ray diffraction. The measurements show that the polymeric bond length between carbon atoms of two nearest molecules C$_60$ is equal to 1.69(1) $\\AA$, the rotation angle of the molecule about the polymeric direction is 47.0(3)$^0$.

  4. Formation of ultracold RbCs molecules by photoassociation

    CERN Document Server

    Bouloufa-Maafa, N; Dulieu, O; Gabbanini, C

    2011-01-01

    The formation of ultracold metastable RbCs molecules is observed in a double species magneto-optical trap through photoassociation below the ^85Rb(5S_1/2)+^133Cs(6P_3/2) dissociation limit followed by spontaneous emission. The molecules are detected by resonance enhanced two-photon ionization. Using accurate quantum chemistry calculations of the potential energy curves and transition dipole moment, we interpret the observed photoassociation process as occurring at short internuclear distance, in contrast with most previous cold atom photoassociation studies. The vibrational levels excited by photoassociation belong to the 5th 0^+ or the 4th 0^- electronic states correlated to the Rb(5P_1/2,3/2)+Cs(6S_1/2) dissociation limit. The computed vibrational distribution of the produced molecules shows that they are stabilized in deeply bound vibrational states of the lowest triplet state. We also predict that a noticeable fraction of molecules is produced in the lowest level of the electronic ground state.

  5. Brucella abortus RB51 in milk of vaccinated adult cattle.

    Science.gov (United States)

    Miranda, Karina Leite; Poester, Fernando Padilla; Dorneles, Elaine Maria Seles; Resende, Thiago Magalhães; Vaz, Adil Knackfuss; Ferraz, Sandra Maria; Lage, Andrey Pereira

    2016-08-01

    The aim of this study was to evaluate the shedding of Brucella abortus in the milk of cows vaccinated with a full dose of RB51 during lactation. Eighteen cows, nine previously vaccinated with S19 as calves and nine non-vaccinated, were immunized subcutaneously with 1.3×10(10)CFU of B. abortus RB51, 30-60days after parturition. Milk samples from all animals were collected daily until day 7, and at weekly interval for the next 9 weeks after vaccination. To evaluate the shedding of B. abortus, milk samples were submitted for culture and PCR. No B. abortus was isolated from any sample tested. Only one sample, collected on first day after vaccination from a cow previously vaccinated, was faintly positive in the PCR. In conclusion, the public health hazard associated with milk consumption from cows vaccinated with RB51 in post-partum is very low, despite vaccination with the full dose and regardless of previous S19 vaccination.

  6. R$_{b}$ and new physics a comprehensive analysis

    CERN Document Server

    Bamert, P; Cline, J M; London, D; Nardi, E

    1996-01-01

    We survey the implications for new physics of the discrepancy between the LEP measurement of R_b and its Standard Model prediction. Two broad classes of models are considered: (i) those in which new Z\\bbar b couplings arise at tree level, through Z or b-quark mixing with new particles, and (ii) those in which new scalars and fermions alter the Z \\bbar b vertex at one loop. We keep our analysis as general as possible in order to systematically determine what kinds of features can produce corrections to R_b of the right sign and magnitude. We are able to identify several successful mechanisms, which include most of those which have been recently been proposed in the literature, as well as some earlier proposals (\\eg\\ supersymmetric models). By seeing how such models appear as special cases of our general treatment we are able to shed light on the reason for, and the robustness of, their ability to explain R_b.

  7. Exploring the structural and functional effect of pRB by significant nsSNP in the coding region of RB1 gene causing retinoblastoma.

    Science.gov (United States)

    Rajasekaran, R; Sethumadhavan, Rao

    2010-02-01

    In this study, we identified the most deleterious nsSNP in RB1 gene through structural and functional properties of its protein (pRB) and investigated its binding affinity with E2F-2. Out of 956 SNPs, we investigated 12 nsSNPs in coding region in which three of them (SNPids rs3092895, rs3092903 and rs3092905) are commonly found to be damaged by I-Mutant 2.0, SIFT and PolyPhen programs. With this effort, we modeled the mutant pRB proteins based on these deleterious nsSNPs. From a comparison of total energy, stabilizing residues and RMSD of these three mutant proteins with native pRB protein, we identified that the major mutation is from Glutamic acid to Glycine at the residue position of 746 of pRB. Further, we compared the binding efficiency of both native and mutant pRB (E746G) with E2F-2. We found that mutant pRB has less binding affinity with E2F-2 as compared to native type. This is due to sixteen hydrogen bonding and two salt bridges that exist between native type and E2F-2, whereas mutant type makes only thirteen hydrogen bonds and one salt bridge with E2F-2. Based on our investigation, we propose that the SNP with an id rs3092905 could be the most deleterious nsSNP in RB1 gene causing retinoblastoma.

  8. A 3 He-129 Xe co-magnetometer with 87 Rb magnetometry

    Science.gov (United States)

    Limes, Mark; Sheng, Dong; Romalis, Mike

    2016-05-01

    We report progress on a 3 He-129 Xe co-magnetometer detected with a 87 Rb magnetometer. The noble-gas co-magnetometer is insensitive to any long-term bias field drifts, but the presence of hot Rb can cause instability in the ratio of 3 He-129 Xe precession frequencies. We use a sequence of Rb π pulses to suppress the instability due to Rb-noble gas interactions by a factor of 104 along all three spatial axes. For detection, our 87 Rb magnetometer operates using single-axis 87 Rb π pulses with σ+ /σ- pumping-this technique decouples the 87 Rb magnetometer from bias fields, and allows for SERF operation. We are presently investigating systematic effects due to combinations of several imperfections, such as longitudinal noble gas polarization, imperfect 87 Rb π pulses, and 87 Rb pump light shifts. Thus far, our 87 Rb magnetometer has a sensitivity of 40 fT/√{Hz}, and our 3 He-129 Xe co-magnetometer has achieved a single-shot precession frequency ratio error of 20 nHz and a long-term bias drift of 8 nHz at 7 h. We are developing the co-magnetometer for use as an NMR gyro, and to search for possible spin-gravity interactions. Supported by DARPA and NSF.

  9. Hydrothermal Synthesis of RbLn2F7 and VUV Spectroscopy of RbLn2F7:Eu3+(Ln=Gd, Y)

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    RbLn2F7 (Ln=Gd, Y, Er, Yb and Lu), crystallized in the hexagonal RbEr2F7 structure type, is synthesized by a hydrothermal method. The excitation spectra of Eu3+-doped RbGd(Y)2F7 suggest that the oxygen content is very low in the samples obtained by hydrothermal synthesis. Only the f-f transitions of Gd3+ ions are observed in the excitation spectrum of RbGd2F7:Eu3+ (0.5mol%), while those of Eu3+ ions do not appear. When the Gd3+ ions are excited, the absorbed energy is transferred efficiently from Gd3+ to Eu3+. The spectra show that the doped Eu3+ ions are located in non-centrosymmetric sites in hexagonal RbLn2F7.

  10. Conditional Deletion of the Retinoblastoma (Rb) Gene in Ovarian Granulosa Cells Leads to Premature Ovarian Failure

    Science.gov (United States)

    Andreu-Vieyra, Claudia; Chen, Ruihong; Matzuk, Martin M.

    2008-01-01

    The retinoblastoma protein (RB) regulates cell proliferation and survival by binding to the E2F family of transcription factors. Recent studies suggest that RB also regulates differentiation in a variety of cell types, including myocytes, neurons, adipocytes, and chondrocytes. Rb mutations have been found in ovarian cancer; however, the role of RB in normal and abnormal ovarian function remains unclear. To test the hypothesis that loss of Rb induces ovarian tumorigenesis, we generated an ovarian granulosa cell conditional knockout of Rb (Rb cKO) using the Cre/lox recombination system. Rb cKO females showed 100% survival and no ovarian tumor formation through 9 months of age, but they developed progressive infertility. Prepubertal Rb cKO females showed increased ovulation rates compared with controls, correlating with increased follicle recruitment, higher Fshr and Kitl mRNA levels, and lower anti-Müllerian hormone levels. In contrast, the ovulation rate of 6-wk-old females was similar to that of controls. Morphometric analysis of Rb cKO ovaries from 6-wk-old and older females showed increased follicular atresia and apoptosis. Rb cKO ovaries and preantral follicles had abnormal levels of known direct and indirect target genes of RB, including Rbl2/p130, E2f1, Ccne2, Myc, Fos, and Tgfb2. In addition, preantral follicles showed increased expression of the granulosa cell differentiation marker Inha, decreased levels of Foxl2 and Cyp19a1 aromatase, and abnormal expression of the nuclear receptors Nr5a1, Nr5a2, and Nr0b1. Taken together, our results suggest that RB is required for the temporal-specific pattern of expression of key genes involved in follicular development. PMID:18599617

  11. In vitro phosphorylation and acetylation of the murine pocket protein Rb2/p130.

    Directory of Open Access Journals (Sweden)

    Muhammad Saeed

    Full Text Available The retinoblastoma protein (pRb and the related proteins Rb2/p130 and 107 represent the "pocket protein" family of cell cycle regulators. A key function of these proteins is the cell cycle dependent modulation of E2F-regulated genes. The biological activity of these proteins is controlled by acetylation and phosphorylation in a cell cycle dependent manner. In this study we attempted to investigate the interdependence of acetylation and phosphorylation of Rb2/p130 in vitro. After having identified the acetyltransferase p300 among several acetyltransferases to be associated with Rb2/p130 during S-phase in NIH3T3 cells in vivo, we used this enzyme and the CDK4 protein kinase for in vitro modification of a variety of full length Rb2/p130 and truncated versions with mutations in the acetylatable lysine residues 1079, 128 and 130. Mutation of these residues results in the complete loss of Rb2/p130 acetylation. Replacement of lysines by arginines strongly inhibits phosphorylation of Rb2/p130 by CDK4; the inhibitory effect of replacement by glutamines is less pronounced. Preacetylation of Rb2/p130 strongly enhances CDK4-catalyzed phosphorylation, whereas deacetylation completely abolishes in vitro phosphorylation. In contrast, phosphorylation completely inhibits acetylation of Rb2/p130 by p300. These results suggest a mutual interdependence of modifications in a way that acetylation primes Rb2/p130 for phosphorylation and only dephosphorylated Rb2/p130 can be subject to acetylation. Human papillomavirus 16-E7 protein, which increases acetylation of Rb2/p130 by p300 strongly reduces phosphorylation of this protein by CDK4. This suggests that the balance between phosphorylation and acetylation of Rb2/p130 is essential for its biological function in cell cycle control.

  12. Generation of a Retinoblastoma (Rb)1-inducible dominant-negative (DN) mouse model.

    Science.gov (United States)

    Tarang, Shikha; Doi, Songila M S R; Gurumurthy, Channabasavaiah B; Harms, Donald; Quadros, Rolen; Rocha-Sanchez, Sonia M

    2015-01-01

    Retinoblastoma 1 (Rb1) is an essential gene regulating cellular proliferation, differentiation, and homeostasis. To exert these functions, Rb1 is recruited and physically interacts with a growing variety of signaling pathways. While Rb1 does not appear to be ubiquitously expressed, its expression has been confirmed in a variety of hematopoietic and neuronal-derived cells, including the inner ear hair cells (HCs). Studies in transgenic mice demonstrate that complete germline or conditional Rb1 deletion leads to abnormal cell proliferation, followed by massive apoptosis; making it difficult to fully address Rb1's biochemical activities. To overcome these limitations, we developed a tetracycline-inducible TetO-CB-myc6-Rb1 (CBRb) mouse model to achieve transient and inducible dominant-negative (DN) inhibition of the endogenous RB1 protein. Our strategy involved fusing the Rb1 gene to the lysosomal protease pre-procathepsin B (CB), thus allowing for further routing of the DN-CBRb fusion protein and its interacting complexes for proteolytic degradation. Moreover, reversibility of the system is achieved upon suppression of doxycycline (Dox) administration. Preliminary characterization of DN-CBRb mice bred to a ubiquitous rtTA mouse line demonstrated a significant inhibition of the endogenous RB1 protein in the inner ear and in a number of other organs where RB1 is expressed. Examination of the postnatal (P) DN-CBRb mice inner ear at P10 and P28 showed the presence of supernumerary inner HCs (IHCs) in the lower turns of the cochleae, which corresponds to the described expression domain of the endogenous Rb1 gene. Selective and reversible suppression of gene expression is both an experimental tool for defining function and a potential means to medical therapy. Given the limitations associated with Rb1-null mice lethality, this model provides a valuable resource for understanding RB1 activity, relative contribution to HC regeneration and its potential therapeutic application.

  13. Melanin Biosynthesis Inhibition Effects of Ginsenoside Rb2 Isolated from Panax ginseng Berry.

    Science.gov (United States)

    Lee, Dae Young; Jeong, Yong Tae; Jeong, Sang Chul; Lee, Mi Kyoung; Min, Jin Woo; Lee, Jae Won; Kim, Geum Soog; Lee, Seung Eun; Ahn, Young Sup; Kang, Hee Cheol; Kim, Jin Hee

    2015-12-28

    Ginsenoside Rb2 (Gin-Rb2) was purified from the fruit extract of Panax ginseng. Its chemical structure was measured by spectroscopic analysis, including HR-FAB-MS, (1)H-NMR, and IR spectroscopy. Gin-Rb2 decreased potent melanogenesis in melan-a cells, with 23.4% at 80 μM without cytotoxicity. Gin-Rb2 also decreased tyrosinase and MITF protein expression in melan-a cells. Furthermore, Gin-Rb2 presented inhibition of the body pigmentation in the zebrafish in vivo system and reduced melanin contents and tyrosinase activity. These results show that Gin-Rb2 isolated from P. ginseng may be an effective skin-whitening agent via the in vitro and in vivo systems.

  14. Photoassociative Production and Detection of Ultracold Polar RbCs Molecules

    Institute of Scientific and Technical Information of China (English)

    JI Zhong-Hua; ZHANG Hong-Shan; WU Ji-Zhou; YUAN Jin-Peng; ZHAO Yan-Ting; MA Jie; WANG Li-Rong; XIAO Lian-Tuan; JIA Suo-Tang

    2011-01-01

    @@ We have produced Ultracold polar RbCs molecules via photoassociation starting from laser-cooled s5Rb and 133 CS atoms in a dual-species, forced dark magneto-optical trap.The formed electronically excited RbCs* molecules correlated to the Rb(5S,12)+Cs(6P1/2) dissociation limit are observed by trap loss spectroscopy.Following the decay of these excited RbCs* molecules, the formed ground state molecules are directly ionized by a two-photon single-color pulse dye laser, which is a new ionization mechanism for ground state RbCs molecules and thence detected by time-of-flight mass spectroscopy.

  15. The RB/E2F pathway and regulation of RNA processing

    Energy Technology Data Exchange (ETDEWEB)

    Ahlander, Joseph [Department of Molecular and Cellular Biology, 1007 East Lowell Street, University of Arizona, Tucson, AZ 85721 (United States); Bosco, Giovanni, E-mail: gbosco@email.arizona.edu [Department of Molecular and Cellular Biology, 1007 East Lowell Street, University of Arizona, Tucson, AZ 85721 (United States)

    2009-07-03

    The retinoblastoma tumor suppressor protein (RB) is inactivated in a majority of cancers. RB restricts cell proliferation by inhibiting the E2F family of transcription factors. The current model for RB/E2F function describes its role in regulating transcription at gene promoters. Whether the RB or E2F proteins might play a role in gene expression beyond transcription initiation is not well known. This review describes evidence that points to a novel role for the RB/E2F network in the regulation of RNA processing, and we propose a model as a framework for future research. The elucidation of a novel role of RB in RNA processing will have a profound impact on our understanding of the role of this tumor suppressor family in cell and developmental biology.

  16. Spin-exchange collision mixing of the K and Rb ac Stark shifts

    Science.gov (United States)

    Chen, Yao; Quan, Wei; Duan, Lihong; Lu, Yan; Jiang, Liwei; Fang, Jiancheng

    2016-11-01

    In a hybrid pumping alkali-metal vapor cell filled with both K and Rb atoms, the K atom spins are optically pumped by the laser and the Rb atom spins are polarized by the K spins through spin exchange. We discovered that the ac Stark shift of the Rb atom spins, caused by the far-off-resonant pumping laser tuned to the K absorption lines, was mixed together with the ac Stark shift of the K atom spins through fast spin exchange. This mixing is studied and we demonstrate a K-Rb-21Ne comagnetometer in which the ac Stark shift of the Rb atom spins is eliminated by compensating for the Rb ac Stark shift with the K ac Stark shift. An ac Stark shift elimination method has been developed.

  17. Photodissociation of Trapped Rb2+: Implications for Simultaneous Trapping of Atoms and Molecular Ions

    Science.gov (United States)

    Jyothi, S.; Ray, Tridib; Dutta, Sourav; Allouche, A. R.; Vexiau, Romain; Dulieu, Olivier; Rangwala, S. A.

    2016-11-01

    The direct photodissociation of trapped 85Rb2+ (rubidium) molecular ions by the cooling light for the 85Rb magneto-optical trap (MOT) is studied, both experimentally and theoretically. Vibrationally excited Rb2+ ions are created by photoionization of Rb2 molecules formed photoassociatively in the Rb MOT and are trapped in a modified spherical Paul trap. The decay rate of the trapped Rb2+ ion signal in the presence of the MOT cooling light is measured and agreement with our calculated rates for molecular ion photodissociation is observed. The photodissociation mechanism due to the MOT light is expected to be active and therefore universal for all homonuclear diatomic alkali metal molecular ions.

  18. Photodissociation of trapped Rb$^+_2$ : Implications for hybrid molecular ion-atom trapping

    CERN Document Server

    Jyothi, S; Dutta, Sourav; Allouche, A R; Vexiau, Romain; Dulieu, Olivier; Rangwala, S A

    2016-01-01

    We observe direct photodissociation of trapped $^{85}$Rb$_2^+$ molecular ions in the presence of cooling light for the $^{85}$Rb magneto optical trap (MOT). Vibrationally excited Rb$_{2}^{+}$ ions are created by photoionization of Rb$_{2}$ molecules formed photoassociatively in the rubidium (Rb) MOT and are trapped in a modified spherical Paul trap co-centric with the MOT. The decay rate of the trapped Rb$_{2}^{+}$ ion signal in the presence of the MOT cooling light is measured and agreement with our calculated rates for molecular ion photodissociation is established. The photodissociation mechanism due to the MOT light is expected to be active and therefore universal for all homonuclear diatomic alkali metal molecular ions.

  19. Inhibition of pRB Pathway Differentially Modulates Apoptosis in Esophageal Cancer Cells.

    Science.gov (United States)

    Soletti, Rossana C; Biasoli, Deborah; Rodrigues, Nathassya A L V; Delou, João M A; Maciel, Renata; Chagas, Vera L A; Martins, Rodrigo A P; Rehen, Stevens K; Borges, Helena L

    2017-10-01

    Esophageal cancer is the sixth most common cause of cancer-related death worldwide. Current chemotherapy regimens include a combination of 5-fluorouracil (5-FU) and cisplatin, but more efficient therapy strategies are needed to increase 5-year survival. Alterations in the signaling pathway of the tumor suppressor gene Rb-1, which encodes a phosphoprotein (pRB) that negatively regulates the G1/S transition of the cell cycle, are present in 70% of all tumors, but its role in esophageal cancer is still unclear. Most of these are alterations leading to up-regulation of the activity of cyclin-dependent kinases (CDKs) to phosphorylate pRB, which suggests that keeping the wild type pRB phosphorylated might be advantageous. Besides proliferation, pRB also regulates apoptosis induced by tumor necrosis factor-alpha (TNF-α) and DNA-damage. We investigated the status of phosphorylation of pRB along esophageal tumorigenesis stages, as well as whether hyperphosphorylation of pRB could suppress apoptosis induced by cisplatin, 5-FU, or TNF-α in esophageal cancer cells. pRB phosphorylation increased progressively from normal esophageal tissue to metaplasia and adenocarcinoma, suggesting that pRB phosphorylation increases along esophageal tumor stages. When RB-1 was knocked down or CDK inhibitors reduced the levels of phosphorylated pRB, opposite apoptotic effects were observed, depending on the combination of drugs tested: whereas TNF-α- and cisplatin-induced apoptosis increased, 5-FU-induced apoptosis decreased. Taken together, these data suggest that pRB plays a role in esophageal adenocarcinoma and that, depending on the type of anti-cancer treatment, combining CDK inhibitors and chemotherapy has the potential to increase the sensitivity of esophageal cancer cells to cell death. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  20. A kinase shRNA screen links LATS2 and the pRB tumor suppressor.

    Science.gov (United States)

    Tschöp, Katrin; Conery, Andrew R; Litovchick, Larisa; Decaprio, James A; Settleman, Jeffrey; Harlow, Ed; Dyson, Nicholas

    2011-04-15

    pRB-mediated inhibition of cell proliferation is a complex process that depends on the action of many proteins. However, little is known about the specific pathways that cooperate with the Retinoblastoma protein (pRB) and the variables that influence pRB's ability to arrest tumor cells. Here we describe two shRNA screens that identify kinases that are important for pRB to suppress cell proliferation and pRB-mediated induction of senescence markers. The results reveal an unexpected effect of LATS2, a component of the Hippo pathway, on pRB-induced phenotypes. Partial knockdown of LATS2 strongly suppresses some pRB-induced senescence markers. Further analysis shows that LATS2 cooperates with pRB to promote the silencing of E2F target genes, and that reduced levels of LATS2 lead to defects in the assembly of DREAM (DP, RB [retinoblastoma], E2F, and MuvB) repressor complexes at E2F-regulated promoters. Kinase assays show that LATS2 can phosphorylate DYRK1A, and that it enhances the ability of DYRK1A to phosphorylate the DREAM subunit LIN52. Intriguingly, the LATS2 locus is physically linked with RB1 on 13q, and this region frequently displays loss of heterozygosity in human cancers. Our results reveal a functional connection between the pRB and Hippo tumor suppressor pathways, and suggest that low levels of LATS2 may undermine the ability of pRB to induce a permanent cell cycle arrest in tumor cells.

  1. Characterization and retinal neuron differentiation of WERI-Rb1 cancer stem cells

    OpenAIRE

    Hu, Huiling; Deng, Fei; Liu, Ying; Chen, Mengfei; Zhang, Xiulan; Sun, Xuerong; Dong, Zhizhang; Xiaohong LIU; Ge, Jian

    2012-01-01

    Purpose The evidence is increasing that cancer stem cells (CSCs) expressing embryonic and neuronal stem cell markers are present in human retinoblastoma (Rb). This study was conducted to determine whether stem-like cancer cells (SLCCs) in Rb express retinal stem cell–related genes and whether SLCCs can directly differentiate into retinal neurons. Methods The cancer stem cell characteristics in WERI-Rb1 cells were determined with Hoechst 33,342 staining, clone formation assay, and CD133 flow c...

  2. RB loss contributes to aggressive tumor phenotypes in MYC-driven triple negative breast cancer.

    Science.gov (United States)

    Knudsen, Erik S; McClendon, A Kathleen; Franco, Jorge; Ertel, Adam; Fortina, Paolo; Witkiewicz, Agnieszka K

    2015-01-01

    Triple negative breast cancer (TNBC) is characterized by multiple genetic events occurring in concert to drive pathogenic features of the disease. Here we interrogated the coordinate impact of p53, RB, and MYC in a genetic model of TNBC, in parallel with the analysis of clinical specimens. Primary mouse mammary epithelial cells (mMEC) with defined genetic features were used to delineate the combined action of RB and/or p53 in the genesis of TNBC. In this context, the deletion of either RB or p53 alone and in combination increased the proliferation of mMEC; however, the cells did not have the capacity to invade in matrigel. Gene expression profiling revealed that loss of each tumor suppressor has effects related to proliferation, but RB loss in particular leads to alterations in gene expression associated with the epithelial-to-mesenchymal transition. The overexpression of MYC in combination with p53 loss or combined RB/p53 loss drove rapid cell growth. While the effects of MYC overexpression had a dominant impact on gene expression, loss of RB further enhanced the deregulation of a gene expression signature associated with invasion. Specific RB loss lead to enhanced invasion in boyden chambers assays and gave rise to tumors with minimal epithelial characteristics relative to RB-proficient models. Therapeutic screening revealed that RB-deficient cells were particularly resistant to agents targeting PI3K and MEK pathway. Consistent with the aggressive behavior of the preclinical models of MYC overexpression and RB loss, human TNBC tumors that express high levels of MYC and are devoid of RB have a particularly poor outcome. Together these results underscore the potency of tumor suppressor pathways in specifying the biology of breast cancer. Further, they demonstrate that MYC overexpression in concert with RB can promote a particularly aggressive form of TNBC.

  3. RB1CC1 activates the p16 promoter through the interaction with hSNF5.

    Science.gov (United States)

    Ochi, Yasuko; Chano, Tokuhiro; Ikebuchi, Kaichiro; Inoue, Hirokazu; Isono, Takahiro; Arai, Akihito; Tameno, Hitosuke; Shimada, Taketoshi; Hisa, Yasuo; Okabe, Hidetoshi

    2011-10-01

    RB1-inducible coiled-coil 1 (RB1CC1, also known as FIP200) is involved in dephosphorylation and increase of retinoblastoma tumor suppressor protein (RB1), but the RB1CC1 molecular mechanism in the dephosphorylation of RB1 is not fully understood. We determined that RB1CC1 activates the expression of p16 (also called INK4a/CDKN2a) through the activation of its promoter, using chromatin immunoprecipitation (ChIP) and p16 promoter-luciferase reporter assays. In addition, RB1CC1 essentially requires binding with hSNF5 (also known as BAF47/INI1, a chromatin-remodeling factor) to activate the p16 promoter, in order to enhance the RB1 pathway and acts as a tumor suppressor. Evaluation of the RB1CC1 mechanism of action is expected to provide useful information for clinical practice and future therapeutic strategies in human cancers.

  4. pRb is an obesity suppressor in hypothalamus and high-fat diet inhibits pRb in this location.

    Science.gov (United States)

    Lu, Zhonglei; Marcelin, Genevieve; Bauzon, Frederick; Wang, Hongbo; Fu, Hao; Dun, Siok Le; Zhao, Hongling; Li, Xiaosong; Jo, Young-Hwan; Wardlaw, Sharon; Dun, Nae; Chua, Streamson; Zhu, Liang

    2013-03-20

    pRb is frequently inactivated in tumours by mutations or phosphorylation. Here, we investigated whether pRb plays a role in obesity. The Arcuate nucleus (ARC) in hypothalamus contains antagonizing POMC and AGRP/NPY neurons for negative and positive energy balance, respectively. Various aspects of ARC neurons are affected in high-fat diet (HFD)-induced obesity mouse model. Using this model, we show that HFD, as well as pharmacological activation of AMPK, induces pRb phosphorylation and E2F target gene de-repression in ARC neurons. Some affected neurons express POMC; and deleting Rb1 in POMC neurons induces E2F target gene de-repression, cell-cycle re-entry, apoptosis, and a hyperphagia-obesity-diabetes syndrome. These defects can be corrected by combined deletion of E2f1. In contrast, deleting Rb1 in the antagonizing AGRP/NPY neurons shows no effects. Thus, pRb-E2F1 is an obesity suppression mechanism in ARC POMC neurons and HFD-AMPK inhibits this mechanism by phosphorylating pRb in this location.

  5. The ancient function of RB-E2F Pathway: insights from its evolutionary history

    Directory of Open Access Journals (Sweden)

    Yang Xianmei

    2010-09-01

    Full Text Available Abstract Background The RB-E2F pathway is conserved in most eukaryotic lineages, including animals and plants. E2F and RB family proteins perform crucial functions in cycle controlling, differentiation, development and apoptosis. However, there are two kinds of E2Fs (repressive E2Fs and active E2Fs and three RB family members in human. Till now, the detail evolutionary history of these protein families and how RB-E2F pathway evolved in different organisms remain poorly explored. Results We performed a comprehensive evolutionary analysis of E2F, RB and DP (dimerization partners of E2Fs protein family in representative eukaryotic organisms. Several interesting facts were revealed. First, orthologues of RB, E2F, and DP family are present in several representative unicellular organisms and all multicellular organisms we checked. Second, ancestral E2F, RB genes duplicated before placozoans and bilaterians diverged, thus E2F family was divided into E2F4/5 subgroup (including repressive E2Fs: E2F4 and E2F5 and E2F1/2/3 subgroup (including active E2Fs: E2F1, E2F2 and E2F3, RB family was divided into RB1 subgroup (including RB1 and RBL subgroup (including RBL1 and RBL2. Third, E2F4 and E2F5 share more sequence similarity with the predicted E2F ancestral sequence than E2F1, E2F2 and E2F3; E2F4 and E2F5 also possess lower evolutionary rates and higher purification selection pressures than E2F1, E2F2 and E2F3. Fourth, for RB family, the RBL subgroup proteins possess lower evolutionary rates and higher purification selection pressures compared with RB subgroup proteins in vertebrates, Conclusions Protein evolutionary rates and purification selection pressures are usually linked with protein functions. We speculated that function conducted by E2F4/5 subgroup and RBL subgroup proteins might mainly represent the ancient function of RB-E2F pathway, and the E2F1/2/3 subgroup proteins and RB1 protein might contribute more to functional diversification in RB-E2F

  6. The ancient function of RB-E2F pathway: insights from its evolutionary history.

    Science.gov (United States)

    Cao, Lihuan; Peng, Bo; Yao, Lei; Zhang, Xinming; Sun, Kuan; Yang, Xianmei; Yu, Long

    2010-09-20

    The RB-E2F pathway is conserved in most eukaryotic lineages, including animals and plants. E2F and RB family proteins perform crucial functions in cycle controlling, differentiation, development and apoptosis. However, there are two kinds of E2Fs (repressive E2Fs and active E2Fs) and three RB family members in human. Till now, the detail evolutionary history of these protein families and how RB-E2F pathway evolved in different organisms remain poorly explored. We performed a comprehensive evolutionary analysis of E2F, RB and DP (dimerization partners of E2Fs) protein family in representative eukaryotic organisms. Several interesting facts were revealed. First, orthologues of RB, E2F, and DP family are present in several representative unicellular organisms and all multicellular organisms we checked. Second, ancestral E2F, RB genes duplicated before placozoans and bilaterians diverged, thus E2F family was divided into E2F4/5 subgroup (including repressive E2Fs: E2F4 and E2F5) and E2F1/2/3 subgroup (including active E2Fs: E2F1, E2F2 and E2F3), RB family was divided into RB1 subgroup (including RB1) and RBL subgroup (including RBL1 and RBL2). Third, E2F4 and E2F5 share more sequence similarity with the predicted E2F ancestral sequence than E2F1, E2F2 and E2F3; E2F4 and E2F5 also possess lower evolutionary rates and higher purification selection pressures than E2F1, E2F2 and E2F3. Fourth, for RB family, the RBL subgroup proteins possess lower evolutionary rates and higher purification selection pressures compared with RB subgroup proteins in vertebrates, Protein evolutionary rates and purification selection pressures are usually linked with protein functions. We speculated that function conducted by E2F4/5 subgroup and RBL subgroup proteins might mainly represent the ancient function of RB-E2F pathway, and the E2F1/2/3 subgroup proteins and RB1 protein might contribute more to functional diversification in RB-E2F pathway. Our results will enhance the current

  7. Study of Rapid Radiochemical Separation of 90Rb from Fission Product

    Institute of Scientific and Technical Information of China (English)

    YUE; Yuan-zhen; MAO; Guo-shu; YANG; Lei; DING; You-qian; MA; Peng

    2015-01-01

    90Rb is a high yield and short-lived fission product,and it is a sensitive monitor at low burnup.The decay data of 90Rb are important,however the uncertainty of the decay data of 90Rb tends to be large,such as the half-life data(58±5)s(with an uncertainty of 3.2%)from ENSDF.In order to get the half-life measured more accurately,a carrier-free 90Rb sample of

  8. Protein phosphatase 2A subunit PR70 interacts with pRb and mediates its dephosphorylation.

    Science.gov (United States)

    Magenta, Alessandra; Fasanaro, Pasquale; Romani, Sveva; Di Stefano, Valeria; Capogrossi, Maurizio C; Martelli, Fabio

    2008-01-01

    The retinoblastoma tumor suppressor protein (pRb) regulates cell proliferation and differentiation via phosphorylation-sensitive interactions with specific targets. While the role of cyclin/cyclin-dependent kinase complexes in the modulation of pRb phosphorylation has been extensively studied, relatively little is known about the molecular mechanisms regulating phosphate removal by phosphatases. Protein phosphatase 2A (PP2A) is constituted by a core dimer bearing catalytic activity and one variable B regulatory subunit conferring target specificity and subcellular localization. We previously demonstrated that PP2A core dimer binds pRb and dephosphorylates pRb upon oxidative stress. In the present study, we identified a specific PP2A-B subunit, PR70, that was associated with pRb both in vitro and in vivo. PR70 overexpression caused pRb dephosphorylation; conversely, PR70 knockdown prevented both pRb dephosphorylation and DNA synthesis inhibition induced by oxidative stress. Moreover, we found that intracellular Ca(2+) mobilization was necessary and sufficient to trigger pRb dephosphorylation and PP2A phosphatase activity of PR70 was Ca(2+) induced. These data underline the importance of PR70-Ca(2+) interaction in the signal transduction mechanisms triggered by redox imbalance and leading to pRb dephosphorylation.

  9. p21 suppresses inflammation and tumorigenesis on pRB-deficient stratified epithelia.

    Science.gov (United States)

    Saiz-Ladera, C; Lara, M F; Garín, M; Ruiz, S; Santos, M; Lorz, C; García-Escudero, R; Martínez-Fernández, M; Bravo, A; Fernández-Capetillo, O; Segrelles, C; Paramio, J M

    2014-09-11

    The retinoblastoma gene product (pRb) controls proliferation and differentiation processes in stratified epithelia. Importantly, and in contrast to other tissues, Rb deficiency does not lead to spontaneous skin tumor formation. As the cyclin-dependent kinase inhibitor p21 regulates proliferation and differentiation in the absence of pRb, we analyzed the consequences of deleting p21 in pRb-ablated stratified epithelia (hereafter pRb(ΔEpi);p21-/-). These mice display an enhancement of the phenotypic abnormalities observed in pRb(ΔEpi) animals, indicating that p21 partially compensates pRb absence. Remarkably, pRb(ΔEpi);p21-/- mice show an acute skin inflammatory phenotype and develop spontaneous epithelial tumors, particularly affecting tongue and oral tissues. Biochemical analyses and transcriptome studies reveal changes affecting multiple pathways, including DNA damage and p53-dependent signaling responses. Comparative metagenomic analyses, together with the histopathological profiles, indicate that these mice constitute a faithful model for human head and neck squamous cell carcinomas. Collectively, our findings demonstrate that p21, in conjunction with pRb, has a central role in regulating multiple epithelial processes and orchestrating specific tumor suppressor functions.

  10. Demonstration of a Dual Alkali Rb/Cs Atomic Fountain Clock

    CERN Document Server

    Guéna, J; Laurent, Ph; Abgrall, M; Rovera, D; Lours, M; Santarelli, G; Tobar, M E; Bize, S; Clairon, A; 10.1109/TUFFC.2010.1461

    2013-01-01

    We report the operation of a dual Rb/Cs atomic fountain clock. 133Cs and 87Rb atoms are cooled, launched, and detected simultaneously in LNE-SYRTE's FO2 double fountain. The dual clock operation occurs with no degradation of either the stability or the accuracy. We describe the key features for achieving such a simultaneous operation. We also report on the results of the first Rb/Cs frequency measurement campaign performed with FO2 in this dual atom clock configuration, including a new determination of the absolute 87Rb hyperfine frequency.

  11. Perfusion imaging using rubidium-82 ((82)Rb) PET in rats with myocardial infarction

    DEFF Research Database (Denmark)

    Clemmensen, Andreas Ettrup; Ghotbi, Adam Ali; Bodholdt, Rasmus Poul

    2017-01-01

    Assessing myocardial perfusion using 82Rb-PET is emerging as a valuable clinical tool.1,2 The rapid decay (T½ = 76 s) allows for absolute quantification of both rest and stress perfusion within 30 minutes. In addition to evaluation of epicardial disease with perfusion defects, also evaluation...... of balanced coronary and small vessel disease is possible. For further evaluation of how 82Rb-PET can be used clinically, pre-clinical application of the method would be valuable. However, so far no data on the use of 82Rb-PET in small animals have been published nor has the use of 82Rb-PET, to the best...

  12. Leptin-LepRb Expressed in Gastric Cancer Patients and Related to Cancer-Related Depression

    Science.gov (United States)

    He, Chenyan; Hui, Lingyun; Huang, Tianhe

    2017-01-01

    Depression is the most common psychiatric disorder among cancer patients. Studies have not only highlighted that leptin and its receptor (LepRb) are independent poor prognostic factors in gastric cancer (GC) patients but also shown that the leptin-LepRb is necessary for antidepressant-like behaviors. In this study, we examined the serum and tissue leptin-LepRb expression in GC patients. Enzyme-linked immunosorbent assay showed that depressive GC patients had significantly higher serum leptin-LepRb than healthy donors. Leptin-LepRb levels in GC tissues were also significantly higher than in matched paracarcinoma tissues using real-time RT-PCR. Moreover, we observed that both serum and tissue leptin-LepRb were significantly higher in depressive GC patients than those in nondepressive GC patients. Further, the patients with high tumor stage tend to have higher leptin-LepRb mRNA levels than that with low tumor stage. Together, our findings suggest that leptin-LepRb plays an important role in the pathogenesis and depression in GC. Leptin-LepRb therefore could be a potential diagnostic marker and therapeutic target in GC patients with depression.

  13. Immune responses of bison and efficacy after booster vaccination with Brucella abortus strain RB51.

    Science.gov (United States)

    Olsen, S C; McGill, J L; Sacco, R E; Hennager, S G

    2015-04-01

    Thirty-one bison heifers were randomly assigned to receive saline or a single vaccination with 10(10) CFU of Brucella abortus strain RB51. Some vaccinated bison were randomly selected for booster vaccination with RB51 at 11 months after the initial vaccination. Mean antibody responses to RB51 were greater (P abortus strain 2308. The incidences of abortion and infection were greater (P Brucella organisms in all tissues, except in retropharyngeal and supramammary lymph nodes. Our study suggests that RB51 booster vaccination is an effective vaccination strategy for enhancing herd immunity against brucellosis in bison.

  14. A comprehensive, sensitive and economical approach for the detection of mutations in the RB1 gene in retinoblastoma

    Indian Academy of Sciences (India)

    Vidya Latha Parsam; Chitra Kannabiran; Santosh Honavar; Geeta K. Vemuganti; Mohammad Javed Ali

    2009-12-01

    Retinoblastoma (Rb) is the most common primary intraocular malignancy in children. It is brought about by the mutational inactivation of both alleles of RB1 gene in the developing retina. To identify the RB1 mutations, we analysed 74 retinoblastoma patients by screening the exons and the promoter region of RB1. The strategy used was to detect large deletions/duplications by fluorescent quantitative multiplex PCR; small deletions/insertions by fluorescent genotyping of RB1 alleles, and point mutations by PCR-RFLP and sequencing. Genomic DNA from the peripheral blood leucocytes of 74 Rb patients (53 with bilateral Rb, 21 with unilateral Rb; 4 familial cases) was screened for mutations. Recurrent mutations were identified in five patients with bilateral Rb, large deletions in 11 patients (nine with bilateral Rb and two with unilateral Rb), small deletions/insertions were found in 12 patients all with bilateral Rb, and point mutations in 26 patients (14 nonsense, six splice site, five substitution and one silent change). Three mutations were associated with variable expressivity of the disease in different family members. Using this method, the detection rates achieved in patients with bilateral Rb were 44/53 (83%) and with unilateral Rb, 5/21 (23.8%). This approach may be feasible for clinical genetic testing and counselling of patients.

  15. Enhanced Spin Depolarization and Storage Time in a Rb Vapor

    Institute of Scientific and Technical Information of China (English)

    QI Yue-Rong; GAO Hong; ZHANG Shou-Gang

    2009-01-01

    The experiment of measuring the spin depolarized time and light storage time in a Rb vapor under different conditions is performed. Typically, these measurements are accomplished in three different containers: atoms in a bare glass ceil, atoms in a buffer gas cell, and atoms in a tetracontane (C40H82) coating cell. The increasing depolarization and storage times are observed in both the buffer gas ceil and the tetracontane coating cell. In the latter case, a storage time greater than 400 μs is obtained.

  16. Phosphorylation of pRB at Ser612 by Chk1/2 leads to a complex between pRB and E2F-1 after DNA damage.

    Science.gov (United States)

    Inoue, Yasumichi; Kitagawa, Masatoshi; Taya, Yoichi

    2007-04-18

    The retinoblastoma tumor suppressor protein (pRB) plays a critical role in the control of cell proliferation and in the DNA damage checkpoints. pRB inhibits cell cycle progression through interactions with the E2F family of transcription factors. Here, we report that DNA damage induced not only the dephosphorylation of pRB at Cdk phosphorylation sites and the binding of pRB to E2F-1, but also the phosphorylation of pRB at Ser612. Phosphorylation of pRB at Ser612 enhanced the formation of a complex between pRB and E2F-1. Substitution of Ser612 with Ala decreased pRB-E2F-1 binding and the transcriptional repression activity. Until now, Ser612 of pRB has been thought to be phosphorylated by Cdk2. However, the phosphorylation of pRB at Ser612 was conducted by Chk1/2 after DNA damage, and inhibition of ATM-Chk1/2 activity suppressed the phosphorylation of Ser612 and the binding of pRB to E2F-1. These results suggest that Ser612 is phosphorylated by Chk1/2 after DNA damage, leading to the formation of pRB-E2F-1. This is the first report that pRB is phosphorylated in vivo by a kinase other than Cdk.

  17. Expression of p16 and pRB in invasive breast cancer.

    Science.gov (United States)

    Shin, Eunah; Jung, Woo-Hee; Koo, Ja-Seung

    2015-01-01

    We aimed to assess protein expressions of p16 and pRB in breast cancer and explore the clinicopathologic implications. Tissue microarray (TMA) was constructed with 406 cases of breast cancer. The cases were subgrouped into luminal A, luminal B, HER-2, and triple negative breast cancer (TNBC) based on the results of immunohistochemical stains for ER, PR, HER-2, and Ki-67 and fluorescent in situ hybridization (FISH) for HER-2. One hundred and sixty-eight cases were allocated to the subgroup luminal A; 87 cases to the luminal B; 32 cases to the HER-2; and 119 cases to the TNBC. The TNBC group showed the highest negative rate for p16, and the luminal B and HER-2 groups showed the highest positive rate for p16 (P pRB expression rate was the highest in the HER-2 group and lowest in the luminal A group. In addition, p16(+)/pRB(+) type was the most common in the luminal B group, p16(+)/pRB(-) in the luminal A group, and p16(-)/pRB(+) in the TNBC group (P pRB(+) and non-altered p16/pRB(+) type was the most common in the luminal B, and altered p16/pRB(-) and non-altered p16/pRB(+) type was the most common in the luminal A (P pRB positivity was correlated with PR negativity (P = 0.009), HER-2 positivity (P = 0.001), and higher Ki-67 LI (P pRB differ according to the molecular subgroups of breast cancer and they subsequently correlate with clnicopathologic factors.

  18. Pandoraea sp. RB-44, A Novel Quorum Sensing Soil Bacterium

    Directory of Open Access Journals (Sweden)

    Robson Ee Han-Jen

    2013-10-01

    Full Text Available Proteobacteria are known to communicate via signaling molecules and this process is known as quorum sensing. The most commonly studied quorum sensing molecules are N-acylhomoserine lactones (AHLs that consists of a homoserine lactone moiety and an N-acyl side chain with various chain lengths and degrees of saturation at the C-3 position. We have isolated a bacterium, RB-44, from a site which was formally a landfill dumping ground. Using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF mass spectrometry analysis, this isolate was identified as a Pandoraea sp.which was then screened for AHL production using biosensors which indicated its quorum sensing properties. To identify the AHL profile of Pandoraea sp. RB-44, we used high resolution tandem mass spectrometry confirming that this isolate produced N-octanoylhomoserine lactone (C8-HSL. To the best of our knowledge, this is the first report that showed quorum sensing activity exhibited by Pandoraea sp. Our data add Pandoraea sp. to the growing number of bacteria that possess QS systems.

  19. Short-range Photoassociation of LiRb

    CERN Document Server

    Blasing, David B; Pérez-Ríos, Jesús; Elliott, Daniel S; Chen, Yong P

    2016-01-01

    We have observed short-range photoassociation of LiRb to the two lowest vibrational states of the $d\\,^3\\Pi$ potential. These $d\\,^3\\Pi$ molecules then spontaneously decay to vibrational levels of the $a^3\\,\\Sigma^+$ state with generation rates of $\\sim10^3$ molecules per second. This is the first observation of many of these $a\\,^3\\Sigma^+$ levels. We observe an alternation of the peak heights in the rotational photoassociation spectrum that suggests a $p$-wave shape resonance in the scattering state. Franck-Condon overlap calculations predict that photoassociation to higher vibrational levels of the $d\\,^3\\Pi$, in particular the sixth vibrational level, should populate the lowest vibrational level of the $a\\,^3\\Sigma^+$ state with a rate as high as $10^4$ molecules per second. These results encourage further work to explain our observed LiRb collisional physics using PECs. This work also motivates an experimental search for short-range photoassociation to other bound molecules, such as the $c\\,^3\\Sigma^+$ o...

  20. Local structure of solid Rb at megabar pressures

    Energy Technology Data Exchange (ETDEWEB)

    De Panfilis, S. [Centre for Life Nano Science IIT@Sapienza, Istituto Italiano di Tecnologia, I-00161 Roma (Italy); Gorelli, F.; Santoro, M. [INO-CNR and LENS, I-50019 Sesto Fiorentino, Firenze (Italy); Ulivi, L. [ISC-CNR, I-50019 Sesto Fiorentino, Firenze (Italy); Gregoryanz, E. [School of Physics and Astronomy, Centre for Science Under Extreme Conditions, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Irifune, T.; Shinmei, T. [Geodynamics Research Center, Ehime University, Matsuyama 790-8577 (Japan); Kantor, I.; Mathon, O.; Pascarelli, S. [European Synchrotron Radiation Facility, F-38043 Grenoble (France)

    2015-06-07

    We have investigated the local and electronic structure of solid rubidium by means of x-ray absorption spectroscopy up to 101.0 GPa, thus doubling the maximum investigated experimental pressure. This study confirms the predicted stability of phase VI and was completed by the combination of two pivotal instrumental solutions. On one side, we made use of nanocrystalline diamond anvils, which, contrary to the more commonly used single crystal diamond anvils, do not generate sharp Bragg peaks (glitches) at specific energies that spoil the weak fine structure oscillations in the x-ray absorption cross section. Second, we exploited the performance of a state-of-the-art x-ray focussing device yielding a beam spot size of 5 × 5 μm{sup 2}, spatially stable over the entire energy scan. An advanced data analysis protocol was implemented to extract the pressure dependence of the structural parameters in phase VI of solid Rb from 51.2 GPa up to the highest pressure. A continuous reduction of the nearest neighbour distances was observed, reaching about 6% over the probed pressure range. We also discuss a phenomenological model based on the Einstein approximation to describe the pressure behaviour of the mean-square relative displacement. Within this simplified scheme, we estimate the Grüneisen parameter for this high pressure Rb phase to be in the 1.3–1.5 interval.

  1. 视肉膜母细胞瘤(RB)抑癌基因治疗原理及策略%Principles and Strategies for Approaching Retinoblastoma (RB) Tumor Suppressor Gene Therapy

    Institute of Scientific and Technical Information of China (English)

    徐洪基; 缪庆; 胡诗学; 刘秉慈

    1999-01-01

    The retinoblastoma (RB) gene was the first tumor suppressor gene identified.It encodes a nuclear phosphoprotein which is differentially phosphorylated during the cell cycle.And the RB gene apparently plays a key role in cell growth regulation.Mutations in RB are seen in virtually all cases of retinoblastoma,and loss of RB gene function has been implicated in the progression of many common human cancers.A number of studies have indicated that replacement of the normal RB gene in RB-defective tumor cells could suppress their tumorigenic activity in nude mice.Preclinical studies also demonstrated that treatment of established human xenograft tumors in nude mice by recombinant adenovirus vectors expressing RB protein resulted in regression of the treated tumor.These studies make the emerging RB gene therapy even more attraction.

  2. Exploring the structural and functional effect of pRB by significant nsSNP in the coding region of RB1 gene causing retinoblastoma

    Institute of Scientific and Technical Information of China (English)

    Rajasekaran; R; Rao; Sethumadhavan

    2010-01-01

    In this study,we identified the most deleterious nsSNP in RB1 gene through structural and functional properties of its protein (pRB) and investigated its binding affinity with E2F-2.Out of 956 SNPs,we investigated 12 nsSNPs in coding region in which three of them (SNPids rs3092895,rs3092903 and rs3092905) are commonly found to be damaged by I-Mutant 2.0,SIFT and PolyPhen programs.With this effort,we modeled the mutant pRB proteins based on these deleterious nsSNPs.From a comparison of total energy,stabilizing residues and RMSD of these three mutant proteins with native pRB protein,we identified that the major mutation is from Glutamic acid to Glycine at the residue position of 746 of pRB.Further,we compared the binding efficiency of both native and mutant pRB (E746G) with E2F-2.We found that mutant pRB has less binding affinity with E2F-2 as compared to native type.This is due to sixteen hydrogen bonding and two salt bridges that exist between native type and E2F-2,whereas mutant type makes only thirteen hydrogen bonds and one salt bridge with E2F-2.Based on our investigation,we propose that the SNP with an id rs3092905 could be the most deleterious nsSNP in RB1 gene causing retinoblastoma.

  3. Rb and p53 Liver Functions Are Essential for Xenobiotic Metabolism and Tumor Suppression

    NARCIS (Netherlands)

    Nantasanti, Sathidpak; Toussaint, Mathilda J. M.; Youssef, Sameh A.; Tooten, Peter C. J.; de Bruin, Alain

    2016-01-01

    The tumor suppressors Retinoblastoma (Rb) and p53 are frequently inactivated in liver diseases, such as hepatocellular carcinomas (HCC) or infections with Hepatitis B or C viruses. Here, we discovered a novel role for Rb and p53 in xenobiotic metabolism, which represent a key function of the liver f

  4. Intermediate-range chemical ordering of cations in molten RbCl-AgCl

    Energy Technology Data Exchange (ETDEWEB)

    Tahara, S. [Department of Physics and Earth Sciences, Faculty of Science, University of the Ryukyus, Okinawa 903-0213 (Japan); Research and Utilization Division, Japan Synchrotron Radiation Research Institute (JASRI, SPring-8), Hyogo 679-5198 (Japan); Kawakita, Y. [J-PARC Center, Japan Atomic Energy Agency (JAEA), Ibaraki 319-1195 (Japan); Shimakura, H. [Faculty of Pharmacy, Niigata University of Pharmacy and Applied Life Sciences, Niigata 956-8603 (Japan); Ohara, K. [Research and Utilization Division, Japan Synchrotron Radiation Research Institute (JASRI, SPring-8), Hyogo 679-5198 (Japan); Fukami, T. [Department of Physics and Earth Sciences, Faculty of Science, University of the Ryukyus, Okinawa 903-0213 (Japan); Takeda, S. [Department of Physics, Faculty of Sciences, Kyushu University, Fukuoka 812-8581 (Japan)

    2015-07-28

    A first sharp diffraction peak (FSDP) is observed in the X-ray total structure factor of a molten mixture of RbCl-AgCl, while both pure melts of RbCl and AgCl do not exhibit FSDP individually. Molecular dynamics simulations were performed to investigate the origin of the FSDP with the polarizable ion model (PIM). Coexistence of covalent Ag–Cl and ionic Rb–Cl bonds leads the system to evolve intermediate range ordering, which is simulated by introducing the induced polarization in different ways between Ag–Cl with fully polarizable treatment based on Vashishta-Raman potential and Rb–Cl with suppression over-polarization in the nearest neighbor contribution based on Born-Meyer potential. The partial structure factors for both the Ag–Ag and Rb–Rb correlations, S{sub AgAg}(Q) and S{sub RbRb}(Q), show a positive contribution to the FSDP, while S{sub AgRb}(Q) for the Ag–Rb correlation exhibits a negative contribution, indicating that Ag and Rb ions are distributed in an alternating manner within the intermediate-range length scale. The origin of the intermediate-range chemical ordering of cations can be ascribed to the preferred direction of the dipole moments of anions in the PIM.

  5. Mutational screening of the RB1 gene in Italian patients with retinoblastoma reveals 11 novel mutations.

    Science.gov (United States)

    Sampieri, Katia; Hadjistilianou, Theodora; Mari, Francesca; Speciale, Caterina; Mencarelli, Maria Antonietta; Cetta, Francesco; Manoukian, Siranoush; Peissel, Bernard; Giachino, Daniela; Pasini, Barbara; Acquaviva, Antonio; Caporossi, Aldo; Frezzotti, Renato; Renieri, Alessandra; Bruttini, Mirella

    2006-01-01

    Retinoblastoma (RB, OMIM#180200) is the most common intraocular tumour in infancy and early childhood. Constituent mutations in the RB1 gene predispose individuals to RB development. We performed a mutational screening of the RB1 gene in Italian patients affected by RB referred to the Medical Genetics of the University of Siena. In 35 unrelated patients, we identified germline RB1 mutations in 6 out of 9 familial cases (66%) and in 7 out of 26 with no family history of RB (27%). Using the single-strand conformational polymorphism (SSCP) technique, 11 novel mutations were detected, including 3 nonsense, 5 frameshift and 4 splice-site mutations. Only two of these mutations (1 splice site and 1 missense) were previously reported. The mutation spectrum reflects the published literature, encompassing predominately nonsense or frameshift and splicing mutations. RB1 germline mutation was detected in 37% of our cases. Gross rearrangements outside the investigated region, altered DNA methylation, or mutations in non-coding regions, may be the cause of disease in the remainder of the patients. Some cases, e.g. a case of incomplete penetrance, or variable expressivity ranging from retinoma to multiple tumours, are discussed in detail. In addition, a case of pre-conception genetic counselling resolved by rescue of banked cordonal blood of the affected deceased child is described.

  6. Experimental research of RB94 gene transfection into retinoblastoma cells using ultrasound-targeted microbubble destruction.

    Science.gov (United States)

    Zheng, Min-Ming; Zhou, Xi-Yuan; Wang, Li-Ping; Wang, Zhi-Gang

    2012-06-01

    The purpose of this study was to explore the transfection of the recombinant expression plasmid pEGFP-C1/RB94 into human retinoblastoma cells (HXO-Rb44) using ultrasound-targeted microbubble destruction (UTMD). pEGFP-C1/RB94 was transfected into HXO-Rb44 in vitro by UTMD, with liposome as the positive control. After 24 to 72 h, the expression of the reporter gene enhanced green fluorescent protein (EGFP) was observed using fluorescent microscopy and flow cytometry. The cell viability of HXO-Rb44 was measured by a MTT assay. The mRNA and proteins of RB94, caspase-3 and Bax were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Moreover, the apoptosis rate and cell cycle progression of the cells were detected by flow cytometry. This study demonstrated that UTMD can enhance the transfection efficiency of RB94, which has an obvious impact on the inhibition of the growth process of retinoblastoma cells, suggesting that the combination of UTMD and RB94 compounds might be a useful tool for use in the gene therapy of retinoblastoma.

  7. Deregulation of the RB pathway in human testicular germ cell tumours

    DEFF Research Database (Denmark)

    Bartkova, Jirina; Lukas, Claudia; Sørensen, Claus S

    2003-01-01

    RB was expressed throughout adult spermatogenesis and was detectable in teratomas, but was absent or grossly reduced in carcinoma in situ (CIS) and most seminomas and embryonal carcinomas. Unexpectedly, we also found that pRB was absent from fetal human gonocytes, the candidate target cell for all types of TGCTs...

  8. The role of p53 and pRB in apoptosis and cancer

    DEFF Research Database (Denmark)

    Hickman, Emma S; Moroni, M Cristina; Helin, Kristian

    2002-01-01

    Loss of function of both the p53 pathway and the retinoblastoma protein (pRB) pathway plays a significant role in the development of most human cancers. Loss of pRB results in deregulated cell proliferation and apoptosis, whereas loss of p53 desensitizes cells to checkpoint signals, including...

  9. Immunohistochemical study of p53, pRb, p16 in esophageal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zo, Jae Ill; Zo, Kyung Ja; Park, Jong Ho; Kim, Mi Hee [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1998-01-01

    To confirm the expression of molecular genetic alterations of p53, pRb, p16 in esophageal cancer and to investigate the expression of p53, pRb, p16 in esophageal cancer according to the pathologic steps of carcinogenesis, immuno-histochemistry was performed in 15 resected esophageal cancer specimens with multiple separated lesions after pathologic mapping. The accumulation of mutant p53 was observed in 60 % of dysplasia and 47 % of invasive cancer, while pRb was not detected in 91 % of dysplasia and 72.7 % of invasive cancer. But p16 was not observed in 0 % in dysplasia and 7 % of invasive cancer. But p16 was not observed in 0 % in dysplasia and 28.6 % in invasive cancer. There was no simultaneous negative pRb and p16 expression. There was no relations between p53 and p16, pRb. As a results, the expression of p53, pRb, p16 was co-related well with molecular genetic changes and inactivation of p53, pRb, p16 was co-related well with molecular genetic changes and inactivation of p53 and pRb was common and early event in esophageal carcinogenesis in Korea, but inactivation of p16 was a infrequent change. (author). 17 refs., 2 tabs., 7 figs

  10. THE ROLE OF RECOMBINANT Rb GENE ADENOVIRUS VECTOR IN THE GROWTH OF LUNG ADENOCARCINOMA CELLS

    Institute of Scientific and Technical Information of China (English)

    Li Jian; Jiang Lei; Xia Yongjing; Li Hongxia; Hu Yajun; Hu Shixue; Xu Hongji

    1998-01-01

    Objective:To study the role of the most extensively studied tumor suppressor gene, retinoblastoma (Rb) gene,on the growth of lung adenocarcinoma cell line GLC-82 and explore a gene therapy approach for lung adenocarcinoma. Methods: The recombinant Rb gene adenovirus vector was constructed, the control virus which carries LacZ gene was producted by the same method. Infection effects were detected by biochemical staining of β-gal and immunohistochemical analysis of Rb protein. The Rb cDNA of infected cells were determined by PCR. The cell growth rate and cell cycle were observed by cell-counting and flow cytometry. Results: The constructed recombinant adenovirus vector could infect effectively the cells with high level expression of Rb cDNA and Rb protein. The transfection of wild-type Rb gene could suppress GLC-82 cell proliferation and decrease the cellular DNA synthesis. Conclusions: These results showed the possibility of using recombinant Rb gene adenovirus vector in the gene therapy of cancer to inhibit the growth of cancer.

  11. RB1CC1 Protein Suppresses Type II Collagen Synthesis in Chondrocytes and Causes Dwarfism*

    Science.gov (United States)

    Nishimura, Ichiro; Chano, Tokuhiro; Kita, Hiroko; Matsusue, Yoshitaka; Okabe, Hidetoshi

    2011-01-01

    RB1-inducible coiled-coil 1 (RB1CC1) functions in various processes, such as cell growth, differentiation, senescence, apoptosis, and autophagy. The conditional transgenic mice with cartilage-specific RB1CC1 excess that were used in the present study were made for the first time by the Cre-loxP system. Cartilage-specific RB1CC1 excess caused dwarfism in mice without causing obvious abnormalities in endochondral ossification and subsequent skeletal development from embryo to adult. In vitro and in vivo analysis revealed that the dwarf phenotype in cartilaginous RB1CC1 excess was induced by reductions in the total amount of cartilage and the number of cartilaginous cells, following suppressions of type II collagen synthesis and Erk1/2 signals. In addition, we have demonstrated that two kinds of SNPs (T-547C and C-468T) in the human RB1CC1 promoter have significant influence on the self-transcriptional level. Accordingly, human genotypic variants of RB1CC1 that either stimulate or inhibit RB1CC1 transcription in vivo may cause body size variations. PMID:22049074

  12. An accurate Rb density measurement method for a plasma wakefield accelerator experiment using a novel Rb reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Öz, E.; Batsch, F.; Muggli, P.

    2016-09-01

    A method to accurately measure the density of Rb vapor is described. We plan on using this method for the Advanced Wakefield (AWAKE) (Assmann et al., 2014 [1]) project at CERN , which will be the world's first proton driven plasma wakefield experiment. The method is similar to the hook (Marlow, 1967 [2]) method and has been described in great detail in the work by Hill et al. (1986) [3]. In this method a cosine fit is applied to the interferogram to obtain a relative accuracy on the order of 1% for the vapor density–length product. A single-mode, fiber-based, Mach–Zenhder interferometer will be built and used near the ends of the 10 meter-long AWAKE plasma source to be able to make accurate relative density measurement between these two locations. This can then be used to infer the vapor density gradient along the AWAKE plasma source and also change it to the value desired for the plasma wakefield experiment. Here we describe the plan in detail and show preliminary results obtained using a prototype 8 cm long novel Rb vapor cell.

  13. An accurate Rb density measurement method for a plasma wakefield accelerator experiment using a novel Rb reservoir

    Science.gov (United States)

    Öz, E.; Batsch, F.; Muggli, P.

    2016-09-01

    A method to accurately measure the density of Rb vapor is described. We plan on using this method for the Advanced Wakefield (AWAKE) (Assmann et al., 2014 [1]) project at CERN , which will be the world's first proton driven plasma wakefield experiment. The method is similar to the hook (Marlow, 1967 [2]) method and has been described in great detail in the work by Hill et al. (1986) [3]. In this method a cosine fit is applied to the interferogram to obtain a relative accuracy on the order of 1% for the vapor density-length product. A single-mode, fiber-based, Mach-Zenhder interferometer will be built and used near the ends of the 10 meter-long AWAKE plasma source to be able to make accurate relative density measurement between these two locations. This can then be used to infer the vapor density gradient along the AWAKE plasma source and also change it to the value desired for the plasma wakefield experiment. Here we describe the plan in detail and show preliminary results obtained using a prototype 8 cm long novel Rb vapor cell.

  14. Formation of ultracold LiRb molecules by photoassociation near the Li(2s 2S1/2) + Rb(5p 2P1/2) asymptote

    Science.gov (United States)

    Dutta, Sourav; Elliott, Daniel S.; Chen, Yong P.

    2013-12-01

    We report the production of ultracold 7Li85Rb molecules by photoassociation (PA) below the Li (2s 2S1/2) + Rb(5p 2P1/2) asymptote. We perform PA spectroscopy in a dual-species 7Li-85Rb magneto-optical trap (MOT) and detect the PA resonances using trap loss spectroscopy. We observe several strong PA resonances corresponding to the last few bound states, assign the lines and derive the long-range C6 dispersion coefficients for the Li (2s 2S1/2) + Rb(5p 2P1/2) asymptote. We also report an excited-state molecule formation rate (P_{\\textit{LiRb}}) of {\\sim}10^{7}\\ \\text{s}^{-1} and a PA rate coefficient (K_{PA}) of {\\sim}4\\times10^{-11}\\ \\text{cm}^3/\\text{s} , which are both among the highest observed for heteronuclear bi-alkali molecules. These suggest that PA is a promising route for the creation of ultracold ground-state LiRb molecules.

  15. Formation of ultracold LiRb molecules by photoassociation near the Li (2s 2S1/2) + Rb (5p 2P1/2) asymptote

    CERN Document Server

    Dutta, Sourav; Chen, Yong P

    2013-01-01

    We report the production of ultracold 7Li85Rb molecules by photoassociation (PA) below the Li (2s 2S1/2) + Rb (5p 2P1/2) asymptote. We perform PA spectroscopy in a dual-species 7Li-85Rb magneto-optical trap (MOT) and detect the PA resonances using trap loss spectroscopy. We observe several strong PA resonances corresponding to the last few bound states, assign the lines and derive the long range C6 dispersion coefficients for the Li (2s 2S1/2) + Rb (5p 2P1/2) asymptote. We also report an excited-state molecule formation rate (P_LiRb) of ~10^7 s^-1 and a PA rate coefficient (K_PA) of ~4x10^-11 cm^3/s, which are both among the highest observed for heteronuclear bi-alkali molecules. These suggest that PA is a promising route for the creation of ultracold ground state LiRb molecules.

  16. New molybdenum(VI) phosphates: synthesis, characterization, and calculations of centrosymmetric RbMoO2PO4 and noncentrosymmetric Rb4Mo5P2O22.

    Science.gov (United States)

    Wang, Ying; Pan, Shilie; Su, Xin; Yang, Zhihua; Dong, Lingyun; Zhang, Min

    2013-02-04

    Two new molybdenum(VI) phosphates, RbMoO(2)PO(4) and Rb(4)Mo(5)P(2)O(22), have been synthesized by standard solid-state reactions, and their structures were determined by single-crystal X-ray diffraction. The former is centrosymmetric, whereas the latter is noncentrosymmetric and chiral. Their crystal structures both consist of corner- and edge-shared MoO(6) octahedra, PO(4) tetrahedra, and RbO(n) (n = 8 or 10) polyhedra and exhibit three- and one-dimensional structures, respectively. Powder second-harmonic generation (SHG) measurements revealed an SHG efficiency of approximately 1.4 × KH(2)PO(4) (KDP) for Rb(4)Mo(5)P(2)O(22). Thermal analysis, infrared and UV-vis-NIR diffuse reflectance spectroscopy, and electronic band structure calculations were also performed on the reported materials. Crystal data are the following: RbMoO(2)PO(4), orthorhombic, space group Fddd (No. 70), a = 11.012(5) Å, b = 12.403(5) Å, c = 15.839(7) Å, V = 2163.3(16) Å(3), and Z = 16; Rb(4)Mo(5)P(2)O(22), orthorhombic, space group C222(1) (No. 20), a = 6.5300(5) Å, b = 19.7834(18) Å, c = 17.3451(15) Å, V = 2240.7(3) Å(3), and Z = 4.

  17. Total absorption γ -ray spectroscopy of the β -delayed neutron emitters Br87 , Br88 , and Rb94

    Energy Technology Data Exchange (ETDEWEB)

    Valencia, E.; Tain, J. L.; Algora, A.; Agramunt, J.; Estevez, E.; Jordan, M. D.; Rubio, B.; Rice, S.; Regan, P.; Gelletly, W.; Podolyák, Z.; Bowry, M.; Mason, P.; Farrelly, G. F.; Zakari-Issoufou, A.; Fallot, M.; Porta, A.; Bui, V. M.; Rissanen, J.; Eronen, T.; Moore, I.; Penttilä, H.; Äystö, J.; Elomaa, V. -V.; Hakala, J.; Jokinen, A.; Kolhinen, V. S.; Reponen, M.; Sonnenschein, V.; Cano-Ott, D.; Garcia, A. R.; Martínez, T.; Mendoza, E.; Caballero-Folch, R.; Gomez-Hornillos, B.; Gorlichev, V.; Kondev, F. G.; Sonzogni, A. A.; Batist, L.

    2017-02-01

    We investigate the decay of Br-87,Br-88 and Rb-94 using total absorption gamma-ray spectroscopy. These important fission products are beta-delayed neutron emitters. Our data show considerable beta gamma intensity, so far unobserved in high-resolution gamma-ray spectroscopy, from states at high excitation energy. We also find significant differences with the beta intensity that can be deduced from existing measurements of the beta spectrum. We evaluate the impact of the present data on reactor decay heat using summation calculations. Although the effect is relatively small it helps to reduce the discrepancy between calculations and integral measurements of the photon component for U-235 fission at cooling times in the range 1-100 s. We also use summation calculations to evaluate the impact of present data on reactor antineutrino spectra. We find a significant effect at antineutrino energies in the range of 5 to 9 MeV. In addition, we observe an unexpected strong probability for. emission from neutron unbound states populated in the daughter nucleus. The. branching is compared to Hauser-Feshbach calculations, which allow one to explain the large value for bromine isotopes as due to nuclear structure. However the branching for Rb-94, although much smaller, hints of the need to increase the radiative width gamma by one order of magnitude. This increase in gamma would lead to a similar increase in the calculated (n, gamma) cross section for this very neutron-rich nucleus with a potential impact on r process abundance calculations.

  18. Biotransformation of ginsenosides Rb1, Rg3 and Rh2 in rat gastrointestinal tracts

    Directory of Open Access Journals (Sweden)

    Qian Tianxiu

    2010-05-01

    Full Text Available Abstract Background Ginsenosides such as Rb1, Rg3 and Rh2 are major bioactive components of Panax ginseng. This in vivo study investigates the metabolic pathways of ginsenosides Rb1, Rg3 and Rh2 orally administered to rats. Methods High performance liquid chromatography-mass spectrometry (LC-MS and tandem mass spectrometry (MS-MS techniques, particularly liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS, were used to identify the metabolites. Results Six metabolites of Rb1, six metabolites of Rg3 and three metabolites of Rh2 were detected in the feces samples of the rats. Rh2 was a metabolite of Rb1 and Rg3, whereas Rg3 was a metabolite of Rb1. Some metabolites such as protopanaxadiol and monooxygenated protopanaxadiol are metabolites of all three ginsenosides. Conclusion Oxygenation and deglycosylation are two major metabolic pathways of the ginsenosides in rat gastrointestinal tracts.

  19. Electric field cancellation on quartz by Rb adsorbate-induced negative electron affinity

    Science.gov (United States)

    Shaffer, James

    2016-05-01

    We investigate the (0001) surface of single crystal quartz with a submonolayer of Rb adsorbates. Using Rydberg atom electromagnetically induced transparency, we investigate the electric fields resulting from Rb adsorbed on the quartz surface, and measure the activation energy of the Rb adsorbates. We show that the adsorbed Rb induces a negative electron affinity (NEA) on the quartz surface. The NEA surface allows low energy electrons to bind to the surface and cancel the electric field from the Rb adsorbates. Our results are important for integrating Rydberg atoms into hybrid quantum systems and the fundamental study of atom-surface interactions, as well as applications for electrons bound to a 2D surface. This work was supported by the DARPA Quasar program by a Grant through ARO (60181-PH-DRP) and the AFOSR (FA9550-12-1-0282),.

  20. Ultralong-Range Rb-KRb Rydberg Molecules: Selected Aspects of Electronic Structure, Orientation and Alignment

    Science.gov (United States)

    Aguilera-Fernández, Javier; Sadeghpour, H. R.; Schmelcher, Peter; González-Férez, Rosario

    2015-09-01

    We investigate the structure and features of an ultralong-range triatomic Rydberg molecule formed by a Rb Rydberg atom and a KRb diatomic molecule. In our numerical description, we perform a realistic treatment of the internal rotational motion of the diatomic molecule, and take into account the Rb(n, l ≥ 3) Rydberg degenerate manifold and the energetically closest neighboring levels with principal quantum numbers n' > n and orbital quantum number l ≤ 2. We focus here on the adiabatic electronic potentials evolving from the Rb(n,l ≥ 3) and Rb(n = 26, l = 2) manifolds. The directional properties of the KRb diatomic molecule within the Rb-KRb triatomic Rydberg molecule are also analyzed in detail.

  1. Immiscibility in a Quantum Degenerate Mixture of $^{87}$Rb and $^{133}$Cs

    CERN Document Server

    McCarron, D J; Jenkin, D L; Köppinger, M P; Cornish, S L

    2011-01-01

    We report a new method for the production of Bose-Einstein condensates of $^{133}$Cs and demonstrate the formation of a quantum degenerate mixture of $^{87}$Rb and $^{133}$Cs. The approach exploits efficient sympathetic cooling of $^{133}$Cs via $^{87}$Rb in a magnetic quadrupole trap prior to further evaporative cooling in a levitated optical trap. Sacrificing all the $^{87}$Rb during the cooling, we create single species $^{133}$Cs condensates of up to $6\\times10^{4}$ atoms. Tailoring the evaporation to retain some $^{87}$Rb, we simultaneously create condensates of $^{87}$Rb and $^{133}$Cs in the same trapping potential, each containing up to $2\\times10^{4}$ atoms. We observe a striking phase separation of the two species revealing the mixture to be immiscible due to strong repulsive interspecies interactions.

  2. Studies of rubidium selenate with secondary phase of RbOH under humidified reducing atmosphere

    DEFF Research Database (Denmark)

    Beyribey, Berceste; Hallinder, Jonathan; Poulsen, Finn Willy;

    2012-01-01

    The high temperature properties of Rb2SeO4 have been studied by calorimetry, impedance spectroscopy and X-ray powder diffraction. As synthesized, Rb2SeO4 includes a second phase of Rb2SeO3, which can be eliminated upon heating the compound. As expected, no conductivity is observed in dry (pH2O ....001 bar) air. By changing to humidified (pH2O = 0.1 bar) air at 176 deg. C, the conductivity increases sharply from 8.6·10-8 to 1.7·10-6 S cm-1. Under humidified (pH2O = 0.1 bar) reducing atmosphere (9%H2 in N2), the conductivity increases to 2.0·10-4 S cm-1 at 317 C. Degradation of Rb2SeO3 and Rb2SeO4...

  3. Ultralong-Range Rb-KRb Rydberg Molecules: Selected Aspects of Electronic Structure, Orientation and Alignment

    CERN Document Server

    Aguilera-Fernández, Javier; Schmelcher, Peter; González-Férez, Rosario

    2015-01-01

    We investigate the structure and features of an ultralong-range triatomic Rydberg molecule formed by a Rb Rydberg atom and a KRb diatomic molecule. In our numerical description, we perform a realistic treatment of the internal rotational motion of the diatomic molecule, and take into account the Rb($n, l\\ge 3$) Rydberg degenerate manifold and the energetically closest neighboring levels with principal quantum numbers $n'>n$ and orbital quantum number $l\\le2$. We focus here on the adiabatic electronic potentials evolving from the Rb($n, l\\ge 3$) and Rb($n=26, l=2$) manifolds. The directional properties of the KRb diatomic molecule within the Rb-KRb triatomic Rydberg molecule are also analyzed in detail.

  4. Absence of pRb facilitates E2F1-induced apoptosis in breast cancer cells.

    Science.gov (United States)

    Sun, Baohua; Wingate, Hannah; Swisher, Stephen G; Keyomarsi, Khandan; Hunt, Kelly K

    2010-03-15

    The transcription factor E2F1 is known for its interaction with pRb, controlling cell proliferation; however, E2F1 also has a pivotal role in regulating apoptosis.  The relationship between pRb and E2F1 balances cell proliferation and apoptosis giving pRb tumor suppressive properties. The intricacies of the pRb/E2F1 relationship and thus the regulation of cell fate is cell context dependent. To explore the role of pRb in the E2F1-induced apoptosis of human breast cancer cells, we examined cell growth and apoptosis induction in isogenic cell systems of immortalized breast epithelial cells lacking either pRb (76NE7) or p53 (76NE6). We found that E2F1 caused accumulation of cells in G2 and S phases of the cell cycle along with apoptosis in 76NE7 but not 76NE6 cells.  Variants of 76NE6 cells with functional p53 did not rescue the apoptotic response in these cells, whereas knocking down pRb resulted in significant E2F1-induced apoptosis. We also determined that the effect of E2F1 overexpression in two breast cancer cell lines, MDA-MB-436 and MDA-MB-468, which lack pRb and functional p53, was accumulation of cells in G2/S phase and apoptosis. However, E2F did not cause apotosis  in MCF-7 cells which harbor a functional pRb. Therefore, we conclude that in the absence of Rb, E2F1 overexpression results in apoptosis, not proliferation, and that this effect is independent of p53.

  5. Deficiency of pRb family proteins and p53 in invasive urothelial tumorigenesis.

    Science.gov (United States)

    He, Feng; Mo, Lan; Zheng, Xiao-Yong; Hu, Changkun; Lepor, Herbert; Lee, Eva Y-H P; Sun, Tung-Tien; Wu, Xue-Ru

    2009-12-15

    Defects in pRb tumor suppressor pathway occur in approximately 50% of the deadly muscle-invasive urothelial carcinomas in humans and urothelial carcinoma is the most prevalent epithelial cancer in long-term survivors of hereditary retinoblastomas caused by loss-of-function RB1 mutations. Here, we show that conditional inactivation of both RB1 alleles in mouse urothelium failed to accelerate urothelial proliferation. Instead, it profoundly activated the p53 pathway, leading to extensive apoptosis, and selectively induced pRb family member p107. Thus, pRb loss triggered multiple fail-safe mechanisms whereby urothelial cells evade tumorigenesis. Additional loss of p53 in pRb-deficient urothelial cells removed these p53-dependent tumor barriers, resulting in late-onset hyperplasia, umbrella cell nuclear atypia, and rare-occurring low-grade, superficial papillary bladder tumors, without eliciting invasive carcinomas. Importantly, mice deficient in both pRb and p53, but not those deficient in either protein alone, were highly susceptible to subthreshold carcinogen exposure and developed invasive urothelial carcinomas that strongly resembled the human counterparts. The invasive lesions had a marked reduction of p107 but not p130 of the pRb family. Our data provide compelling evidence, indicating that urothelium, one of the slowest cycling epithelia, is remarkably resistant to transformation by pRb or p53 deficiency; that concurrent loss of these two tumor suppressors is necessary but insufficient to initiate urothelial tumorigenesis along the invasive pathway; that p107 may play a critical role in suppressing invasive urothelial tumor formation; and that replacing/restoring the function of pRb, p107, or p53 could be explored as a potential therapeutic strategy to block urothelial tumor progression.

  6. Experimental Model to Study the Role of Retinoblastoma Gene Product (pRb) for Determination of Adipocyte Differentiation.

    Science.gov (United States)

    Popov, B V; Shilo, P S; Zhidkova, O V; Zaichik, A M; Petrov, N S

    2015-06-01

    Using stable constitutive expression of retinoblastoma gene product (pRb) in polypotent mesenchymal 10T1/2 cells we obtained stable cell lines hyperexpressing functionally active or inactive mutant pRb. The cells producing active exogenous pRb demonstrated high sensitivity to adipocyte differentiation inductors, whereas production of inactive form of the exogenous protein suppressed adipocyte differentiation. The obtained lines can serve as the experimental model for studying the role of pRb in determination of adipocyte differentiation.

  7. Short-range photoassociation of LiRb

    Science.gov (United States)

    Blasing, D. B.; Stevenson, I. C.; Pérez-Ríos, J.; Elliott, D. S.; Chen, Y. P.

    2016-12-01

    We have observed short-range photoassociation of 7Li85Rb to the two lowest vibrational states of the d 3Π potential. We have also observed several a3Σ+ vibrational levels with generation rates between ˜102 and ˜103 molecules per second, resulting from the spontaneous decay of these d 3Π molecules. We observe an alternation of the peak heights in the rotational photoassociation spectrum that depends on the parity of the excited molecular state. Franck-Condon overlap calculations predict that photoassociation to higher vibrational levels of the d 3Π potential, in particular, the sixth vibrational level, should populate the lowest vibrational level of the a 3Σ+ state at a rate as high as 104 molecules per second. This work also motivates an experimental search for short-range photoassociation to other bound molecular states, such as c 3Σ+ or b 3Π , as prospects for preparing ground-state molecules.

  8. Radiative Decay of Proton Colliding with Rb at Low Energies

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yu; QU Yi-Zhi; LIU Chun-Hua; LIU Xiao-Ju

    2011-01-01

    The radiative decay and radiative charge transfer cross sections for H++Rb(5s) collisions are calculated by using the optical potential approach, the semiclassical and the fully quantum-mechanical methods, respectively, for the energy range 10-6-10eV. The radiative association cross sections are obtained by the cross section differences between the radiative decay and radiative charge transfer processes. The relevant molecular data are calculated from the multi-reference single- and double-excitation configuration interaction approach. The emission spectra at resonant and non-resonant energies are analyzed, then the isolated sharp and broad resonances can be identified by their rotational and vibration quantum numbers.

  9. Blackbody radiation shift in 87Rb frequency standard

    CERN Document Server

    Safronova, M S; Safronova, U I

    2010-01-01

    The operation of atomic clocks is generally carried out at room temperature, whereas the definition of the second refers to the clock transition in an atom at absolute zero. This implies that the clock transition frequency should be corrected in practice for the effect of finite temperature of which the leading contributor is the blackbody radiation (BBR) shift. Experimental measurements of the BBR shifts are difficult. In this work, we have calculated the blackbody radiation shift of the ground-state hyperfine microwave transition in 87Rb using the relativistic all-order method and carried out detailed evaluation of the accuracy of our final value. Particular care is taken to accurately account for the contributions from highly-excited states. Our predicted value for the Stark coefficient, k_S=-1.240(4)\\times 10^{-10}\\text{Hz/(V/m)}^{2} is three times more accurate than the previous calculation [1].

  10. Preparation of Cs-Rb-V series sulphuric acid catalyst

    Institute of Scientific and Technical Information of China (English)

    陈振兴; 杨刚; 叶华

    2001-01-01

    Cs-Rb-V series low temperature sulphuric acid catalyst was prepared for the first time by using carbonized mother liquor containing alkali-metal salts. The results show that the conversion of SO2 on catalyst prepared directly with carbonized mother liquor could reach to 24.8% at 410℃. If n(Na)/n(V) was adjusted properly, the conversion of SO2 could be increased to 35.6% at 410℃. Refined carbonized mother liquor could make the catalytic activity even higher at low temperature, the conversion of SO2 could be increased to 36.65% at 410℃. The catalyst was examined with differential thermal analysis. It was found that both endothermic peaks and exothermic peaks of catalyst shifted forward obviously and the catalyst possessed higher activity at low temperature.

  11. Enhanced frequency up-conversion in Rb vapor

    CERN Document Server

    Vernier, A; Riis, E; Arnold, A S

    2009-01-01

    We demonstrate highly efficient generation of coherent 420 nm light via up-conversion of near-infrared lasers in a hot rubidium vapor cell. By optimizing pump polarizations and frequencies we achieve a single-pass conversion efficiency of 260%/W, significantly higher than in previous experiments. A full 2D exploration of the coherent light generation and fluorescence as a function of the pump frequencies reveals that coherent blue light is generated at 85Rb two-photon resonances, as predicted by theory, but at high vapor pressure it is suppressed in spectral regions that don't support phase matching or exhibit single-photon Kerr refraction. Favorable scaling of our current 1 mW blue beam power with additional pump power is predicted. Infrared pump polarization could be used for future intensity switching experiments.

  12. Racing to block tumorigenesis after pRb loss: an innocuous point mutation wins with synthetic lethality.

    Science.gov (United States)

    Bauzon, Frederick; Zhu, Liang

    2010-06-01

    A major goal of tumor suppressor research is to neutralize the tumorigenic effects of their loss. Since loss of pRb does not induce tumorigenesis in many types of cells, natural mechanisms may neutralize the tumorigenic effects of pRb loss in these cells. For susceptible cells, neutralizing the tumorigenic effects of pRb loss could logically be achieved by correcting the deregulated activities of pRb targets to render pRb-deficient cells less abnormal. This line of research has unexpectedly revealed that knocking out the pRb target Skp2 did not render Rb1 deficient cells less abnormal but, rather, induced apoptosis in them, thereby completely blocking tumorigenesis in Rb1+/- mice and after targeted deletion of Rb1 in pituitary intermediate lobe (IL). Skp2 is a substrate-recruiting component of the SCFSkp2 E3 biquitin ligase; one of its substrates is Thr187-phosphorylated p27Kip1. A p27T187A knockin (KI) mutation phenocopied Skp2 knockout (KO) in inducing apoptosis following Rb1 loss. Thus, Skp2 KO or p27T187A KI are synthetic lethal with pRb inactivation. Since homozygous p27T187A KI mutations show no adverse effects in mice, inhibiting p27T187 phosphorylation or p27T187p ubiquitination could be a highly therapeutic and minimally toxic intervention strategy for pRb deficiency-induced tumorigenesis.

  13. pRB and E2F4 play distinct cell-intrinsic roles in fetal erythropoiesis.

    Science.gov (United States)

    Zhang, Jing; Lee, Eunice Y; Liu, Yangang; Berman, Seth D; Lodish, Harvey F; Lees, Jacqueline A

    2010-01-15

    The retinoblastoma tumor suppressor protein pRB functions, at least in part, by directly binding to and modulating the activity of the E2F transcription factors. Previous studies have shown that both E2F4 and pRB play important roles in fetal erythropoiesis. Given that these two proteins interact directly we investigated the overlap of E2F4 and pRB function in this process by analyzing E2f4(-/-), conditional Rb knockout (Rb(1lox/1lox)), and compound E2f4(-/-);Rb(1lox/1lox) embryos. At E15.5 E2f4(-/-) and Rb(1lox/1lox) fetal erythroid cells display distinct abnormalities in their differentiation profiles. When cultured in vitro, both E2f4(-/-) and Rb(1lox/1lox) erythroid cells show defects in cell cycle progression. Surprisingly, analysis of cell cycle profiling suggests that E2F4 and pRB control cell cycle exit through different mechanisms. Moreover, only pRB, but not E2F4, promotes cell survival in erythroid cells. We observed an additive rather than a synergistic impact upon the erythroid defects in the compound E2f4(-/-);Rb(1lox/1lox) embryos. We further found that fetal liver macrophage development is largely normal regardless of genotype. Taken together, our results show that E2F4 and pRB play independent cell-intrinsic roles in fetal erythropoiesis.

  14. pRB is required for interferon-gamma-induction of the MHC class II abeta gene.

    Science.gov (United States)

    Zhu, X; Pattenden, S; Bremner, R

    1999-09-02

    pRB is required for IFN-gamma-induction of MHC class II in human tumor cell lines, providing a potential link between tumor suppressors and the immune system. However, other genes, such as cyclin D1, show pRB-dependency only in tumor cells, so by analogy, pRB may not be necessary for cII-regulation in normal cells. Here, we demonstrate that induction of the mouse MHC class II I-A heterodimer is normal in RB+/+ mouse embryonic fibroblasts (MEFs), but deficient in RB-/- MEFs. Inducibility is restored in RB-/- MEFs stably transfected with wild type RB cDNA or infected with an adenovirus expressing pRB. Thus, involvement of pRB in MHC class II expression is conserved in the mouse and is not an aberrant feature of tumorigenic, aneuploid, human tumor cells. Although cII genes are generally induced in a coordinate fashion, suggesting a common mechanism, we found that pRB was specifically required for induction of the Abeta, but not Aalpha or other MHC cII genes including Ebeta, Ii and H2-Malpha. Finally, IFN-gamma-induction of class II transactivator (CIITA), was pRB-independent, suggesting that pRB works downstream of this master-regulator of MHC class II expression.

  15. Efficacy of dart or booster vaccination with strain RB51 in protecting bison against experimental Brucella abortus challenge

    Science.gov (United States)

    Vaccination is an effective tool for reducing the prevalence of brucellosis in natural hosts. In this study, we characterized the efficacy of the Brucella abortus strain RB51 (RB51) vaccine in bison when delivered by single intramuscular vaccination (Hand RB51), single pneumatic dart delivery (Dart ...

  16. Immune Responses and Protection against Experimental Brucella suis biovar 1 Challenge in Non-vaccinated or RB51-Vaccinated Cattle

    Science.gov (United States)

    Twenty Hereford heifers, approximately 9 months of age, were vaccinated with saline (control) or 2 x 10**10 CFU of Brucella abortus strain RB51 (RB51) vaccine. Immunologic responses after inoculation demonstrated significantly greater (P<0.05) antibody and proliferative responses to RB51 antigens i...

  17. Site-specific hyperphosphorylation of pRb in HIV-induced neurotoxicity.

    Science.gov (United States)

    Akay, C; Lindl, K A; Wang, Y; White, M G; Isaacman-Beck, J; Kolson, D L; Jordan-Sciutto, K L

    2011-06-01

    HIV-Associated Neurocognitive Disorder (HAND) remains a serious complication of HIV infection, despite combined Anti-Retroviral Therapy (cART). Neuronal dysfunction and death are attributed to soluble factors released from activated and/or HIV-infected macrophages. Most of these factors affect the cell cycle machinery, determining cellular outcomes even in the absence of cell division. One of the earliest events in cell cycle activation is hyperphosphorylation of the retinoblastoma protein, pRb (ppRb). We and others have previously shown increased ppRb expression in the CNS of patients with HIV encephalitis (HIVE) and in neurons in an in vitro model of HIV-induced neurodegeneration. However, trophic factors also lead to an increase in neuronal ppRb with an absence of cell death, suggesting that, depending on the stimulus, hyperphosphorylation of pRb can have different outcomes on neuronal fate. pRb has multiple serines and threonines targeted for phosphorylation by distinct kinases, and we hypothesized that different stimuli may target separate sites for phosphorylation. Thus, to determine whether pRb is differentially phosphorylated in response to different stimuli and whether any of these sites is preferentially phosphorylated in association with HIV-induced neurotoxicity, we treated primary rat mixed cortical cultures with trophic factors, BDNF or RANTES, or with the neurotoxic factor, N-methyl-d-aspartate (NMDA), or with supernatants containing factors secreted by HIV-infected monocyte-derived macrophages (HIV-MDM), our in vitro model of HIV-induced neurodegeneration. We found that, while BDNF and RANTES phosphorylated serine807/811 and serine608 in vitro, treatment with HIV-MDM did not, even though these trophic factors are components of HIV-MDM. Rather, HIV-MDM targets a specific phosphorylation site, serine795, of pRb for phosphorylation in vitro and this ppRb isoform is also increased in HIV-infected brains in vivo. Further, overexpression of a

  18. Prognostic significance of cyclinD1 amplification and the co-alteration of cyclinD1/pRb/ppRb in patients with esophageal squamous cell carcinoma.

    Science.gov (United States)

    Wang, M-T; Chen, G; An, S-J; Chen, Z-H; Huang, Z-M; Xiao, P; Ben, X-S; Xie, Z; Chen, S-L; Luo, D-L; Tang, J-M; Lin, J-Y; Zhang, X-C; Wu, Y-L

    2012-01-01

    CyclinD1/pRb/ppRb is one of the most important pathways regulating the cell cycle, and related with the development of many cancers. However, the co-alteration of CyclinD1/pRb/ppRb in esophageal squamous cell carcinomas is less understood. This study aims to analyze the combined prognostic significance of cyclinD1 (CCND1) DNA amplification and the co-alteration of CCND1/pRb/ppRB in patients with esophageal squamous cell carcinoma. CCND1 DNA amplification and the protein expression of CCND1, pRb, and ppRb on 100 tumor specimens and 11 normal tissues were detected using real-time quantitative reverse transcription polymerase chain reaction and immunohistochemistry, respectively. Their prognosis significance was analyzed by Kaplan-Meier method. We found that 41% of the patients had CCND1 DNA amplification, which had a short survival time compared with the patients without CCND1 amplification (25.63 months vs. not reached, P=0.007). The patients with the co-alternation of CCND1(+) /pRb(-) /ppRb(+) protein expression levels have a poorer overall survival than the others (11.4 vs. 43.4 months, P=0.001). Cox regression analysis showed that the co-alternation of CCND1/pRb/ppRb and CyclinD1 amplification were the two most independent prognosis factors of patients with esophageal cancer. These findings suggested that CCND1 amplification and co-alternation of CCND1(+) /pRb(-) /ppRb(+) may play a crucial role in the prognostic evaluation of patients with esophageal cancer, and the patients with CCND1(+) /pRb(-) /ppRb(+) have the worst prognosis in all the patients. The results also indicated that the patients with CCND1 amplification or co-alternation of CyclinD1(+) /pRb(-) /ppRb(+) might be the preponderant people for therapy targeting the CCND1/pRb/ppRb pathway in the future.

  19. Derivation of Apollo 14 High-Al Basalts at Discrete Times: Rb-Sr Isotopic Constraints

    Science.gov (United States)

    Hui. Hejiu; Neal, Clive, R.; Shih, Chi-Yu; Nyquist, Laurence E.

    2012-01-01

    Pristine Apollo 14 (A-14) high-Al basalts represent the oldest volcanic deposits returned from the Moon [1,2] and are relatively enriched in Al2O3 (>11 wt%) compared to other mare basalts (7-11 wt%). Literature Rb-Sr isotopic data suggest there are at least three different eruption episodes for the A-14 high-Al basalts spanning the age range approx.4.3 Ga to approx.3.95 Ga [1,3]. Therefore, the high-Al basalts may record lunar mantle evolution between the formation of lunar crust (approx.4.4 Ga) and the main basin-filling mare volcanism (basalts were originally classified into five compositional groups [5,6], and then regrouped into three with a possible fourth comprising 14072 based on the whole-rock incompatible trace element (ITE) ratios and Rb-Sr radiometric ages [7]. However, Rb-Sr ages of these basalts from different laboratories may not be consistent with each other because of the use of different 87Rb decay constants [8] and different isochron derivation methods over the last four decades. This study involved a literature search for Rb-Sr isotopic data previously reported for the high-Al basalts. With the re-calculated Rb-Sr radiometric ages, eruption episodes of A-14 high-Al basalts were determined, and their petrogenesis was investigated in light of the "new" Rb-Sr isotopic data and published trace element abundances of these basalts.

  20. The tumor suppressors pRB and p53 as regulators of adipocyte differentiation and function

    DEFF Research Database (Denmark)

    Hallenborg, Philip; Feddersen, Søren; Madsen, Lise

    2009-01-01

    BACKGROUND: The retinoblastoma protein (pRB) and p53 are crucial members of regulatory networks controlling the cell cycle and apoptosis, and a hallmark of virtually all cancers is dysregulation of expression or function of pRB or p53. Although they are best known for their role in cancer develop...... of energy metabolism and homeostasis. RESULTS/CONCLUSIONS: pRB is required for adipose conversion and also involved in determining its mitochondrial capacity. p53 inhibits adipogenesis and results suggest that it is involved in maintaining function of adipose tissue.......BACKGROUND: The retinoblastoma protein (pRB) and p53 are crucial members of regulatory networks controlling the cell cycle and apoptosis, and a hallmark of virtually all cancers is dysregulation of expression or function of pRB or p53. Although they are best known for their role in cancer...... development, it is now evident that both are implicated in metabolism and cellular development. OBJECTIVE/METHODS: To review the role of pRB and p53 in adipocyte differentiation and function emphasizing that pRB and p53, via their effects on adipocyte development and function, play a role in the regulation...

  1. Suppression of genome instability in pRB-deficient cells by enhancement of chromosome cohesion.

    Science.gov (United States)

    Manning, Amity L; Yazinski, Stephanie A; Nicolay, Brandon; Bryll, Alysia; Zou, Lee; Dyson, Nicholas J

    2014-03-20

    Chromosome instability (CIN), a common feature of solid tumors, promotes tumor evolution and increases drug resistance during therapy. We previously demonstrated that loss of the retinoblastoma protein (pRB) tumor suppressor causes changes in centromere structure and generates CIN. However, the mechanism and significance of this change was unclear. Here, we show that defects in cohesion are key to the pRB loss phenotype. pRB loss alters H4K20 methylation, a prerequisite for efficient establishment of cohesion at centromeres. Changes in cohesin regulation are evident during S phase, where they compromise replication and increase DNA damage. Ultimately, such changes compromise mitotic fidelity following pRB loss. Remarkably, increasing cohesion suppressed all of these phenotypes and dramatically reduced CIN in cancer cells lacking functional pRB. These data explain how loss of pRB undermines genomic integrity. Given the frequent functional inactivation of pRB in cancer, conditions that increase cohesion may provide a general strategy to suppress CIN.

  2. Neuroprotective effects of ginsenoside Rb1 on hippocampal neuronal injury and neurite outgrowth

    Institute of Scientific and Technical Information of China (English)

    Juan Liu; Jing He; Liang Huang; Ling Dou; Shuang Wu; Qionglan Yuan

    2014-01-01

    Ginsenoside Rb1 has been reported to exert anti-aging and anti-neurodegenerative effects. In the present study, we investigate whether ginsenoside Rb1 is involved in neurite outgrowth and neuroprotection against damage induced by amyloid beta (25-35) in cultured hippocampal neu-rons, and explore the underlying mechanisms. Ginsenoside Rb1 significantly increased neurite outgrowth in hippocampal neurons, and increased the expression of phosphorylated-Akt and phosphorylated extracellular signal-regulated kinase 1/2. These effects were abrogated by API-2 and PD98059, inhibitors of the signaling proteins Akt and MEK. Additionally, cultured hippo-campal neurons were exposed to amyloid beta (25-35) for 30 minutes; ginsenoside Rb1 prevented apoptosis induced by amyloid beta (25-35), and this effect was blocked by API-2 and PD98059. Furthermore, ginsenoside Rb1 significantly reversed the reduction in phosphorylated-Akt and phosphorylated extracellular signal-regulated kinase 1/2 levels induced by amyloid beta (25-35), and API-2 neutralized the effect of ginsenoside Rb1. The present results indicate that ginsenoside Rb1 enhances neurite outgrowth and protects against neurotoxicity induced by amyloid beta (25-35) via a mechanism involving Akt and extracellular signal-regulated kinase 1/2 signaling.

  3. RB1 deficiency in triple-negative breast cancer induces mitochondrial protein translation

    Science.gov (United States)

    Jones, Robert A.; Robinson, Tyler J.; Liu, Jeff C.; Shrestha, Mariusz; Voisin, Veronique; Ju, YoungJun; Chung, Philip E.D.; Pellecchia, Giovanna; Fell, Victoria L.; Bae, SooIn; Muthuswamy, Lakshmi; Egan, Sean E.; Jiang, Zhe; Leone, Gustavo; Bader, Gary D.; Schimmer, Aaron

    2016-01-01

    Triple-negative breast cancer (TNBC) includes basal-like and claudin-low subtypes for which no specific treatment is currently available. Although the retinoblastoma tumor-suppressor gene (RB1) is frequently lost together with TP53 in TNBC, it is not directly targetable. There is thus great interest in identifying vulnerabilities downstream of RB1 that can be therapeutically exploited. Here, we determined that combined inactivation of murine Rb and p53 in diverse mammary epithelial cells induced claudin-low–like TNBC with Met, Birc2/3-Mmp13-Yap1, and Pvt1-Myc amplifications. Gene set enrichment analysis revealed that Rb/p53-deficient tumors showed elevated expression of the mitochondrial protein translation (MPT) gene pathway relative to tumors harboring p53 deletion alone. Accordingly, bioinformatic, functional, and biochemical analyses showed that RB1-E2F complexes bind to MPT gene promoters to regulate transcription and control MPT. Additionally, a screen of US Food and Drug Administration–approved (FDA-approved) drugs identified the MPT antagonist tigecycline (TIG) as a potent inhibitor of Rb/p53-deficient tumor cell proliferation. TIG preferentially suppressed RB1-deficient TNBC cell proliferation, targeted both the bulk and cancer stem cell fraction, and strongly attenuated xenograft growth. It also cooperated with sulfasalazine, an FDA-approved inhibitor of cystine xCT antiporter, in culture and xenograft assays. Our results suggest that RB1 deficiency promotes cancer cell proliferation in part by enhancing mitochondrial function and identify TIG as a clinically approved drug for RB1-deficient TNBC. PMID:27571409

  4. Whole chromosome instability resulting from the synergistic effects of pRB and p53 inactivation.

    Science.gov (United States)

    Manning, A L; Benes, C; Dyson, N J

    2014-05-01

    Whole chromosome instability (CIN) is a common feature of cancer cells and has been linked to increased tumor evolution and metastasis. Several studies have shown that the loss of the pRB tumor suppressor causes mitotic defects and chromosome mis-segregation. pRB is inactivated in many types of cancer and this raises the possibility that the loss of pRB may be a general cause of CIN in tumors. Paradoxically, retinoblastoma tumor cells have a relatively stable karyotype and currently the circumstances in which pRB inactivation causes CIN in human cancers are unclear. Here we utilize a fluorescence in situ hybridization-based approach to score numerical heterogeneity in chromosome copy number as a readout of CIN. Using this technique, we show that high levels of CIN correlate with the combined inactivation of pRB and p53 and that this association is evident in two independent panels of cancer cell lines. Retinoblastoma cell lines characteristically retain a wild-type TP53 gene, providing an opportunity to test the relevance of this functional relationship. We show that retinoblastoma cell lines display mitotic defects similar to those seen when pRB is depleted from non-transformed cells, but that the presence of wild-type p53 suppresses the accumulation of aneuploid cells. A similar synergy between pRB and p53 inactivation was observed in HCT116 cells. These results suggest that the loss of pRB promotes segregation errors, whereas loss of p53 allows tolerance and continued proliferation of the resulting, genomically unstable cancer cells. Hence, it is the cooperative effect of inactivation of both pRB and p53 tumor suppressor pathways that promotes CIN.

  5. Tissue microarray immunohistochemical profiles of p53 and pRB in hepatocellular carcinoma and hepatoblastoma.

    Science.gov (United States)

    Azlin, Abdul Hadi; Looi, Lai Meng; Cheah, Phaik Leng

    2014-01-01

    The tumour suppressor genes, p53 and pRb, are known to play important roles in neoplastic transformation. While molecular routes to the uncontrolled growth of hepatocytes, leading to primary liver cancer have generated considerable interest, the roles of p53 and pRb mutations in hepatocellular carcinoma (HCC) and hepatoblastoma (HB) remain to be clarified. We examined the immunohistochemical expression of p53 and pRb gene products in 26 HCC and 9 HB, sampled into tissue microarray blocks. 10 (38%) of 26 HCC showed > 10% tumour nuclear staining for p53 protein, 3 of these also being HbsAg positive. Conversely, none of 9 HB expressed nuclear p53 immunopositivity. Some 24 (92%) HCC and 8 (89%) HB showed loss of pRb nuclear expression. Two of the 26 HCC and one of the 9 HB showed >10% tumour nuclear staining for pRb protein. Our results suggest that p53 does not have an important role in the development of HB but may contribute in HCC. There is also loss of pRb expression in the majority of HCC and HB, supporting loss of pRb gene function in the hepatocarcinogenesis pathway. However, a comparison of the staining profiles of p53 and pRb proteins in HCC and HB did not reveal a consistent pattern to differentiate between the two types of tumours immunohistochemically. Hence the use of p53 and pRB protein expression has no contribution in the situation where there is a diagnostic difficulty in deciding between HCC and HB.

  6. Cooperative activation of tissue-specific genes by pRB and E2F1.

    Science.gov (United States)

    Flowers, Stephen; Xu, Fuhua; Moran, Elizabeth

    2013-04-01

    The retinoblastoma tumor suppressor protein pRB is conventionally regarded as an inhibitor of the E2F family of transcription factors. Conversely, pRB is also recognized as an activator of tissue-specific gene expression along various lineages including osteoblastogenesis. During osteoblast differentiation, pRB directly targets Alpl and Bglap, which encode the major markers of osteogenesis alkaline phosphatase and osteocalcin. Surprisingly, p130 and repressor E2Fs were recently found to cooccupy and repress Alpl and Bglap in proliferating osteoblast precursors before differentiation. This raises the further question of whether these genes convert to E2F activation targets when differentiation begins, which would constitute a remarkable situation wherein pRB and E2F would be cotargeting genes for activation. Chromatin immunoprecipitation analysis in an osteoblast differentiation model shows that Alpl and Bglap are indeed targeted by an activator E2F, i.e., is E2F1. Promoter occupation of Alpl and Bglap by E2F1 occurs specifically during activation, and depletion of E2F1 severely impairs their induction. Mechanistically, promoter occupation by E2F1 and pRB is mutually dependent, and without this cooperative effect, activation steps previously shown to be dependent on pRB, including recruitment of RNA polymerase II, are impaired. Myocyte- and adipocyte-specific genes are also cotargeted by E2F1 and pRB during differentiation along their respective lineages. The finding that pRB and E2F1 cooperate to activate expression of tissue-specific genes is a paradigm distinct from the classical concept of pRB as an inhibitor of E2F1, but is consistent with the observed roles of these proteins in physiological models.

  7. Rb1 gene inactivation expands satellite cell and postnatal myoblast pools.

    Science.gov (United States)

    Hosoyama, Tohru; Nishijo, Koichi; Prajapati, Suresh I; Li, Guangheng; Keller, Charles

    2011-06-03

    Satellite cells are well known as a postnatal skeletal muscle stem cell reservoir that under injury conditions participate in repair. However, mechanisms controlling satellite cell quiescence and activation are the topic of ongoing inquiry by many laboratories. In this study, we investigated whether loss of the cell cycle regulatory factor, pRb, is associated with the re-entry of quiescent satellite cells into replication and subsequent stem cell expansion. By ablation of Rb1 using a Pax7CreER,Rb1 conditional mouse line, satellite cell number was increased 5-fold over 6 months. Furthermore, myoblasts originating from satellite cells lacking Rb1 were also increased 3-fold over 6 months, while terminal differentiation was greatly diminished. Similarly, Pax7CreER,Rb1 mice exhibited muscle fiber hypotrophy in vivo under steady state conditions as well as a delay of muscle regeneration following cardiotoxin-mediated injury. These results suggest that cell cycle re-entry of quiescent satellite cells is accelerated by lack of Rb1, resulting in the expansion of both satellite cells and their progeny in adolescent muscle. Conversely, that sustained Rb1 loss in the satellite cell lineage causes a deficit of muscle fiber formation. However, we also show that pharmacological inhibition of protein phosphatase 1 activity, which will result in pRb inactivation accelerates satellite cell activation and/or expansion in a transient manner. Together, our results raise the possibility that reversible pRb inactivation in satellite cells and inhibition of protein phosphorylation may provide a new therapeutic tool for muscle atrophy by short term expansion of the muscle stem cells and myoblast pool.

  8. MDM2/MDMX: Master negative regulators for p53 and RB.

    Science.gov (United States)

    Hu, Linshan; Zhang, Haibo; Bergholz, Johann; Sun, Shengnan; Xiao, Zhi-Xiong Jim

    2016-03-01

    MDM2 (mouse double minute 2 homolog) and MDMX (double minute X human homolog, also known as MDM4) are critical negative regulators of tumor protein p53. Our recent work shows that MDMX binds to and promotes degradation of retinoblastoma protein (RB) in an MDM2-dependent manner. In a xenograft tumor growth mouse model, silencing of MDMX results in inhibition of p53-deficient tumor growth, which can be effectively reversed by concomitant RB silencing. Thus, MDMX exerts its oncogenic activity via suppression of RB.

  9. The role of p53 and pRB in apoptosis and cancer

    DEFF Research Database (Denmark)

    Hickman, Emma S; Moroni, M Cristina; Helin, Kristian

    2002-01-01

    Loss of function of both the p53 pathway and the retinoblastoma protein (pRB) pathway plays a significant role in the development of most human cancers. Loss of pRB results in deregulated cell proliferation and apoptosis, whereas loss of p53 desensitizes cells to checkpoint signals, including...... apoptosis. In the past two years, mouse genetics and gene expression profiling have led to major advances in our understanding of how the pRB and p53 pathways regulate apoptosis and thus the development of tumours....

  10. Dual-species Bose-Einstein condensate of Rb87 and Cs133

    Science.gov (United States)

    McCarron, D. J.; Cho, H. W.; Jenkin, D. L.; Köppinger, M. P.; Cornish, S. L.

    2011-07-01

    We report the formation of a dual-species Bose-Einstein condensate of Rb87 and Cs133 in the same trapping potential. Our method exploits the efficient sympathetic cooling of Cs133 via elastic collisions with Rb87, initially in a magnetic quadrupole trap and subsequently in a levitated optical trap. The two condensates each contain up to 2×104 atoms and exhibit a striking phase separation, revealing the mixture to be immiscible due to strong repulsive interspecies interactions. Sacrificing all the Rb87 during the cooling, we create single-species Cs133 condensates of up to 6×104 atoms.

  11. Inhibitory Effects of Ginsenoside-Rb2 on Nicotinic Stimulation-Evoked Catecholamine Secretion

    Science.gov (United States)

    Lim, Hyo-Jeong; Lee, Hyun-Young

    2014-01-01

    The aim of the present study was to investigate whether ginsenoside-Rb2 (Rb2) can affect the secretion of catecholamines (CA) in the perfused model of the rat adrenal medulla. Rb2 (3~30 µM), perfused into an adrenal vein for 90 min, inhibited ACh (5.32 mM)-evoked CA secretory response in a dose- and time-dependent fashion. Rb2 (10 µM) also time-dependently inhibited the CA secretion evoked by DMPP (100 µM, a selective neuronal nicotinic receptor agonist) and high K+ (56 mM, a direct membrane depolarizer). Rb2 itself did not affect basal CA secretion (data not shown). Also, in the presence of Rb2 (50 µg/mL), the secretory responses of CA evoked by veratridine (a selective Na+ channel activator (50 µM), Bay-K-8644 (an L-type dihydropyridine Ca2+ channel activator, 10 µM), and cyclopiazonic acid (a cytoplasmic Ca2+-ATPase inhibitor, 10 µM) were significantly reduced, respectively. Interestingly, in the simultaneous presence of Rb2 (10 µM) and L-NAME (an inhibitor of NO synthase, 30 µM), the inhibitory responses of Rb2 on ACh-evoked CA secretory response was considerably recovered to the extent of the corresponding control secretion compared with the inhibitory effect of Rb2-treatment alone. Practically, the level of NO released from adrenal medulla after the treatment of Rb2 (10 µM) was greatly elevated compared to the corresponding basal released level. Collectively, these results demonstrate that Rb2 inhibits the CA secretory responses evoked by nicotinic stimulation as well as by direct membrane-depolarization from the isolated perfused rat adrenal medulla. It seems that this inhibitory effect of Rb2 is mediated by inhibiting both the influx of Ca2+ and Na+ into the adrenomedullary chromaffin cells and also by suppressing the release of Ca2+ from the cytoplasmic calcium store, at least partly through the increased NO production due to the activation of nitric oxide synthase, which is relevant to neuronal nicotinic receptor blockade. PMID:25352764

  12. Direct production of ultracold rovibronic ground state LiRb molecules through photoassociation and spontaneous decay

    CERN Document Server

    Stevenson, I C; Chen, Y P; Elliott, D S

    2016-01-01

    We report a newly observed photoassociation resonance in $^7$Li-$^{85}$Rb, a mixed $2(1) - 4(1)$ excited state, that spontaneously decays to the rovibronic ground state. This resonance between ultracold Li and Rb is the strongest ground state molecule-forming photoassociation line observed in LiRb, and forms deeply bound $X \\: ^1\\Sigma^+$ molecules in large numbers. The production rate of the $v=0 \\ J=0$ rovibrational ground state is $\\sim 1.5 \\times 10^{4}$ molecules/s.

  13. Cortical excitatory neurons become protected from cell division during neurogenesis in an Rb family-dependent manner.

    Science.gov (United States)

    Oshikawa, Mio; Okada, Kei; Nakajima, Kazunori; Ajioka, Itsuki

    2013-06-01

    Cell cycle dysregulation leads to abnormal proliferation and cell death in a context-specific manner. Cell cycle progression driven via the Rb pathway forces neurons to undergo S-phase, resulting in cell death associated with the progression of neuronal degeneration. Nevertheless, some Rb- and Rb family (Rb, p107 and p130)-deficient differentiating neurons can proliferate and form tumors. Here, we found in mouse that differentiating cerebral cortical excitatory neurons underwent S-phase progression but not cell division after acute Rb family inactivation in differentiating neurons. However, the differentiating neurons underwent cell division and proliferated when Rb family members were inactivated in cortical progenitors. Differentiating neurons generated from Rb(-/-); p107(-/-); p130(-/-) (Rb-TKO) progenitors, but not acutely inactivated Rb-TKO differentiating neurons, activated the DNA double-strand break (DSB) repair pathway without increasing trimethylation at lysine 20 of histone H4 (H4K20), which has a role in protection against DNA damage. The activation of the DSB repair pathway was essential for the cell division of Rb-TKO differentiating neurons. These results suggest that newly born cortical neurons from progenitors become epigenetically protected from DNA damage and cell division in an Rb family-dependent manner.

  14. Irreversibility of cellular senescence: dual roles of p16INK4a/Rb-pathway in cell cycle control

    Directory of Open Access Journals (Sweden)

    Hara Eiji

    2007-03-01

    Full Text Available Abstract The retinoblastoma (Rb tumor suppressor gene product, pRb, has an established role in the implementation of cellular senescence, the state of irreversible G1 cell cycle arrest provoked by diverse oncogenic stresses. In murine cells, senescence cell cycle arrest can be reversed by subsequent inactivation of pRb, indicating that pRb is required not only for the onset of cellular senescence, but also for the maintenance of senescence program in murine cells. However, in human cells, once pRb is fully activated by p16INK4a, senescence cell cycle arrest becomes irreversible and is no longer revoked by subsequent inactivation of pRb, suggesting that p16INK4a/Rb-pathway activates an alternative mechanism to irreversibly block the cell cycle in human senescent cells. Here, we discuss the molecular mechanism underlying the irreversibility of senescence cell cycle arrest and its potential towards tumor suppression.

  15. Preparation and Structural Characterization of Superionic Conductor RbAg4I5 Crystalline Grain Film

    Institute of Scientific and Technical Information of China (English)

    曹阳; 孙红三; 孙家林; 田广彦; 邢志; 郭继华

    2003-01-01

    Superionic conductor RbAg4I5 crystalline grainfilms were prepared by vacuum thermal evaporation on NaCl crystalline substrates. The surface morphology, microstructure and the electronic energy states of the films were examined by atomic force microscopy, transmission-electron microscopy, x-ray diffraction and x-ray photoelectron spectroscopy. The results show that the obtained RbAg4I5 layer has an epitaxial film of perfect crystalline structure, and the unit cell of crystalline grain RbAg4I5 films belongs to cubic crystal system. The principal x-ray diffraction peaks at d = 3.7447 and 1.8733A are related to the structure of ternary compound RbAg4I5films.

  16. Preparation and Structural Characterization of Superionic Conductor RbAg4I5 Crystalline Grain Film

    Science.gov (United States)

    Cao, Yang; Sun, Hong-San; Sun, Jia-Lin; Tian, Guang-Yan; Xing, Zhi; Guo, Ji-Hua

    2003-05-01

    Superionic conductor RbAg4I5 crystalline grain films were prepared by vacuum thermal evaporation on NaCl crystalline substrates. The surface morphology, microstructure and the electronic energy states of the films were examined by atomic force microscopy, transmission-electron microscopy, x-ray diffraction and x-ray photoelectron spectroscopy. The results show that the obtained RbAg4I5 layer has an epitaxial film of perfect crystalline structure, and the unit cell of crystalline grain RbAg4I5 films belongs to cubic crystal system. The principal x-ray diffraction peaks at d = 3.7447 and 1.8733 Å are related to the structure of ternary compound RbAg4I5 films.

  17. Observation of hyperfine interaction in photoassociation spectra of ultracold RbYb

    Science.gov (United States)

    Bruni, C.; Görlitz, A.

    2016-08-01

    We report on the creation of ultracold heteronuclear and electronically excited Rb*Yb molecules in a hybrid conservative trap by photoassociation of ultracold 87Rb and 176Yb. The molecules are formed below the Rb5 p 1(1/2 2P)+Yb6 s 2(S10) dissociation limit and the resonances are detected using trap-loss spectroscopy. By addressing vibrational levels with binding energies down to EB=-h ×2.2 THz , we study the change in hyperfine coupling of the diatomic molecule as a function of internuclear separation. We observe a decreasing hyperfine splitting for more tightly bound excited molecular states where the hyperfine splitting is reduced by more than 30 % compared to the atomic value for 87Rb.

  18. Generation of continuous-wave and pulsed squeezed light with $^{87}$Rb vapor

    CERN Document Server

    Agha, Imad H; Grangier, Philippe

    2009-01-01

    We present experimental studies on the generation of squeezed vacuum via nonlinear ellipse rotation in a $^{87}$Rb vapor. Squeezing is observed for a wide range of input powers and pump detunings on the D1 line, while only excess noise is present on the D2 line. The maximum squeezing observed is -1.4 $\\pm$0.1 dB (-2.0 dB corrected for loss). We measure -1.1 dB squeezing at the resonance frequency of the $^{85}$Rb $F=2 \\to F'=3$ transition, which may allow the storage of squeezed light generated by $^{87}$Rb in a $^{85}$Rb quantum memory. We also demonstrate a proof of principle pulsed squeezed light experiment, with -1 dB of squeezing for 200 ns pulse width.

  19. Generation of pulsed and continuous-wave squeezed light with 87Rb vapor.

    Science.gov (United States)

    Agha, Imad H; Messin, Gaétan; Grangier, Philippe

    2010-03-01

    We present experimental studies on the generation of pulsed and continuous-wave squeezed vacuum via nonlinear rotation of the polarization ellipse in a (87)Rb vapor. Squeezing is observed for a wide range of input powers and pump detunings on the D1 line, while only excess noise is present on the D2 line. The maximum continuous-wave squeezing observed is -1.4 +/- 0.1 dB (-2.0 dB corrected for losses). We measure -1.1 dB squeezing at the resonance frequency of the (85)Rb F = 3 --> F' transition, which may allow the storage of squeezed light generated by (87)Rb in a (85)Rb quantum memory. Using a pulsed pump, pulsed squeezed light with -1 dB of squeezing for 200 ns pulse widths is observed at 1 MHz repetition rate.

  20. Non-centrosymmetric Rb2Mn2(MoO43

    Directory of Open Access Journals (Sweden)

    Chahira Bouzidi

    2014-07-01

    Full Text Available The title compound, dirubidium dimanganese(II tris(tetraoxomolybdate, Rb2Mn2(MoO43, was prepared by solid-state reactions. The structure can be described as being composed of MnO6 octahedra sharing corners with MoO4 tetrahedra. The three-dimensional framework contains cavities in which the rubidium ions are located. The Rb+ cations are within distorted nine- and 12-vertex polyhedra. The pairs of different Mn2+ and Rb+ cations are each located on threefold rotation axes.. Rb2Mn2(MoO43 is isotypic with compounds of the Cs2M2Mo3O12 (M = Ni, Fe family. A comparative structural description is provided between the structure of the title compound and those of related phases. Differences with structures such as alluaudite are discussed.

  1. pRB Takes an EZ Path to a Repetitive Task.

    Science.gov (United States)

    Sanidas, Ioannis; Dyson, Nicholas J

    2016-12-15

    Repetitive DNA elements are essential for genome function; in this issue of Molecular Cell, Ishak et al. (2016) describe a novel mechanism of epigenetic repression at these elements that requires pRB-dependent recruitment of EZH2.

  2. pRb controls estrogen receptor alpha protein stability and activity.

    Science.gov (United States)

    Caligiuri, Isabella; Toffoli, Giuseppe; Giordano, Antonio; Rizzolio, Flavio

    2013-06-01

    A cross talk between the Estrogen Receptor (ESR1) and the Retinoblastoma (pRb) pathway has been demonstrated to influence the therapeutic response of breast cancer patients but the full mechanism remains poorly understood. Here we show that the N-terminal domain of pRb interacts with the CD domain of ESR1 to allow for the assembly of intermediate complex chaperone proteins HSP90 and p23. We demonstrated that a loss of pRb in human/mouse breast cells decreases the expression of the ESR1 protein through the proteasome pathway. Our work reveals a novel regulatory mechanism of ESR1 basal turnover and activity and an unanticipated relationship with the pRb tumor suppressor.

  3. Antitumor mechanisms when pRb and p53 are genetically inactivated.

    Science.gov (United States)

    Zhu, L; Lu, Z; Zhao, H

    2015-08-27

    pRb and p53 are the two major tumor suppressors. Their inactivation is frequent when cancers develop and their reactivation is rationale of most cancer therapeutics. When pRb and p53 are genetically inactivated, cells irreparably lose the antitumor mechanisms afforded by them. Cancer genome studies document recurrent genetic inactivation of RB1 and TP53, and the inactivation becomes more frequent in more advanced cancers. These findings may explain why more advanced cancers are more likely to resist current therapies. Finding successful treatments for more advanced and multi-therapy-resistant cancers will depend on finding antitumor mechanisms that remain effective when pRb and p53 are genetically inactivated. Here, we review studies that have begun to make progress in this direction.

  4. Data of evolutionary structure change: 1E1RB-2HLDT [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1E1RB-2HLDT 1E1R 2HLD B T DLEETGRVLSIGDGIARVHGLRNVQAEEMVEFSSGLKGM...SDRLVKEGELVKRTGNIVDVPVGPGLLGRVVDALGNPIDGKGPIDAAGRSRAQVKAPGILPRRSVHEPVQTGLKAVDALVPIGRGQRELIIGDRQTGKTAVALDT...T 2HLDT ALKQVAGSLKLFL2HLD T 2HLDT VAAFAQDLDAST

  5. Delayed neutron studies of separated isotopes of Br, Rb, I, and Cs

    CERN Document Server

    Reeder, R L; Wright, J F

    1976-01-01

    Discusses delayed neutron studies of separated isotopes of Br, Rb, I, and Cs are currently in progress at the Spectrometer for On-Line Analysis of Radionuclides (SOLAR) facility operated by Battelle, Pacific Northwest Laboratories. (2 refs).

  6. Decoupled Rb-Sr and Sm-Nd isotopic evolution of the continental crust

    Science.gov (United States)

    Goldstein, S. L.

    1988-01-01

    Evidence was presented that the Rb-Sr and Sm-Nd isotopic systems are decoupled in crust-mantle evolution. Rare earth element (including Sm and Nd) residue principally in silicates, and are resistant to mobilization by weathering and metamorphism. In contrast, Rb and Sr are easily fractionated by crustal processes and residue in carbonates as well as in silicates. As a result, continental Sr, but not Nd, can be recycled into the mantle by exchange of seawater with basalt at spreading ridges and by subduction of carbonates associated with ridge processes. These effects result in mean Rb-Sr ages of the continental crust and of the upper mantle that are too young. Crustal growth curves based largely on Rb-Sr data, such that of Hurley and Rand, are therefore incorrect.

  7. Thermodynamic properties of solid face centered cubic Rb3C60 at high temperature and pressure

    Science.gov (United States)

    Yang, W.; Sun, J. X.; Liu, H.; Yan, G. F.

    2014-03-01

    Analytic equation of state and thermodynamic quantities of solid fcc Rb3C60 are derived by using an analytic mean field potential method. For intermolecular forces, the double-exponential potential is utilized. Four potential parameters are determined by fitting experimental compression data of Rb3C60 up to 14 GPa at 296 K. Various physical quantities including isothermals, thermal expansion, isochoric heat capacity, Helmholtz free energy and internal energy are calculated and analyzed. Calculated results are consistent with available experimental data in literature. Furthermore, spinodal temperature for Rb3C60 is found to be 2,860 K. Results verify that analytic mean field potential method is a useful approach to consider the anharmonic effect at high temperatures. Numerous reasonable predictions and the change trend of the properties for Rb3C60 at high temperature and pressure have been given.

  8. Measurement of the Spin-Dipolar Part of the Tensor Polarizability of Rb 87

    Science.gov (United States)

    Dallal, Yehonatan; Ozeri, Roee

    2015-10-01

    We report on the measurement of the contribution of the magnetic-dipole hyperfine interaction to the tensor polarizaility of the electronic ground state in Rb 87 . This contribution was isolated by measuring the differential shift of the clock transition frequency in Rb 87 atoms that were optically trapped in the focus of an intense CO2 laser beam. By comparing to previous tensor polarizability measurements in Rb 87 , the contribution of the interaction with the nuclear electric-quadrupole moment was isolated as well. Our measurement will enable better estimation of blackbody shifts in Rb atomic clocks. The methods reported here are applicable for future spectroscopic studies of atoms and molecules under strong quasistatic fields.

  9. R.B. Kitaj (1932-2007: Warburgian Artist

    Directory of Open Access Journals (Sweden)

    Chaney, Edward

    2013-12-01

    Full Text Available This essay examines the influence of Aby Warburg and the Warburg Institute, as mediated by Edgar Wind, on R.B. Kitaj from the late 1950s until his death in 2007. It is based on research in the National Portrait Gallery, the Warburg Institute Archive, the Wind archives in Oxford, Kitaj’s unpublished autobiography and correspondence between the author and the artist dating back to 1972. It explores Kitaj’s creative response to Warburg’s brand of cultural history which encouraged his early eschewal of the prevailing focus upon formal values in favour of ‘symbolic images’ and suggestive content. This tendency was enhanced by his increasing celebration of his Jewishness and aspirations towards the creation of ‘a Jewish art like the Egyptian figurative style’. Kitaj’s portrait of Ernst Gombrich (1986 was commissioned by the National Portrait Gallery at a time when he was becoming obsessed with his Jewish project while Gombrich was confirming his rejection of the category Jewish, in other than a religious context, altogether. Discussion of Jewishness and the arts in the twentieth century is supplemented by the identification of David Allan’s Origin of Painting (done in Italy in 1775 as the inspiration for Kitaj’s Los Angeles series of pictures in which his late, lamented wife is depicted as the Hebrew deity, Shekinah.

  10. Effects of Ginsenoside Rb1 on Skin Changes

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Kimura

    2012-01-01

    Full Text Available Ginseng roots (Panax ginseng CA Meyer have been used traditionally for the treatment, especially prevention, of various diseases in China, Korea, and Japan. Both experimental and clinical studies suggest ginseng roots to have pharmacological effects in patients with life-style-related diseases such as non-insulin-dependent diabetic mellitus, atherosclerosis, hyperlipidemia, and hypertension. The topical use of ginseng roots to treat skin complaints including atopic suppurative dermatitis, wounds, and inflammation is also described in ancient Chinese texts; however, there have been relatively few studies in this area. In the present paper, we describe introduce the biological and pharmacological effects of ginsenoside Rb1 isolated from Red ginseng roots on skin damage caused by burn-wounds using male Balb/c mice (in vivo and by ultraviolet B irradiation using male C57BL/6J and albino hairless (HR-1 mice (in vivo. Furthermore, to clarify the mechanisms behind these pharmacological actions, human primary keratinocytes and the human keratinocyte cell line HaCaT were used in experiments in vitro.

  11. Continuous Vibrational Cooling of Ground State Rb2

    Science.gov (United States)

    Tallant, Jonathan; Marcassa, Luis

    2014-05-01

    The process of photoassociation generally results in a distribution of vibrational levels in the electronic ground state that is energetically close to the dissociation limit. Several schemes have appeared that aim to transfer the population from the higher vibrational levels to lower ones, especially the ground vibrational state. We demonstrate continuous production of vibrationally cooled Rb2 using optical pumping. The vibrationally cooled molecules are produced in three steps. First, we use a dedicated photoassociation laser to produce molecules in high vibrational levels of the X1Σg+ state. Second, a broadband fiber laser at 1071 nm is used to transfer the molecules to lower vibrational levels via optical pumping through the A1Σu+ state. This process transfers the molecules from vibrational levels around ν ~= 113 to a distribution of levels where ν superluminescent diode near 685 nm that has its frequency spectrum shaped. The resulting vibrational distributions are probed using resonance-enhanced multiphoton ionization with a pulsed dye laser near 670 nm. The results are presented and compared with theoretical simulations. This work was supported by Fapesp and INCT-IQ.

  12. Blackbody radiation shift in the Rb87 frequency standard

    Science.gov (United States)

    Safronova, M. S.; Jiang, Dansha; Safronova, U. I.

    2010-08-01

    The operation of atomic clocks is generally carried out at room temperature, whereas the definition of the second refers to the clock transition in an atom at absolute zero. This implies that the clock transition frequency should be corrected in practice for the effect of finite temperature, of which the leading contributor is the blackbody radiation (BBR) shift. Experimental measurements of the BBR shifts are difficult. In this work, we have calculated the blackbody radiation shift of the ground-state hyperfine microwave transition in Rb87 using the relativistic all-order method and carried out a detailed evaluation of the accuracy of our final value. Particular care is taken to accurately account for the contributions from highly excited states. Our predicted value for the Stark coefficient, kS=-1.240(4)×10-10Hz/(V/m)2, is three times more accurate than the previous calculation [E. J. Angstman, V. A. Dzuba, and V. V. Flambaum, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.74.023405 74, 023405 (2006)].

  13. Signature splitting inversion and backbending in 80Rb

    CERN Document Server

    He, Chuangye; Wen, Shuxian; Zhu, Lihua; Wu, Xiaoguang; Li, Guangsheng; Zhao, Yue; Yan, Yupeng; Bai, Zhijun; Wu, Yican; Li, Yazhou; Li, Gui; Yan, Shiwei; Oshima, M; Toh, Y; Osa, A; Koizumi, M; Hatsukawa, Y; Matsuda, M; Hagakawa, T

    2012-01-01

    High spin states of 80Rb are studied via the fusion-evaporation reactions 65Cu+19F, 66Zn+18O and 68Zn+16O with the beam energies of 75 MeV, 76 MeV and 80 MeV, respectively. Twenty-three new states with twenty-eight new \\gamma transitions were added to the previously proposed level scheme, where the second negative-parity band is significantly pushed up to spins of 22^{-} and 15^{-} and two new sidebands are built on the known first negative-parity band. Two successive band crossings with frequencies 0.51 MeV and 0.61 MeV in the \\alpha=0 branch as well as another one in the \\alpha=1 branch of the second negative-parity band are observed for the first time. Signature inversions occur in the positive- and first negative-parity bands at the spins of 11\\hbar and 15\\hbar, respectively. The signature splitting is seen obviously in the second negative-parity band, but the signature inversion is not observed. It is also found that the structure of the two negative-parity bands is similar to that of its isotone ^{82}Y....

  14. Microbiological Transform Ginsenoside Rb1 into Rg3%微生物转化人参皂苷Rb1为Rg3的研究

    Institute of Scientific and Technical Information of China (English)

    白龙律; 臧蕴霞; 尹成日

    2009-01-01

    利用18种菌株对人参皂苷Rb1进行生物转化研究,发现一种绿毛状GY-06菌使人参皂苷Rb1有效地转化为Rg3.经形态学和内转录间隔区(internal transcribed spacer, ITS)基因序列分析,确定其为一种扩展青霉(Penicillium expansum).

  15. 微生物转化人参皂苷Rb1为C-K的研究%Microbiological Transformation of Ginsenoside Rb1 into C-K

    Institute of Scientific and Technical Information of China (English)

    金艳; 尹成日; 金恩华

    2010-01-01

    利用23种菌株对人参皂苷Rb1进行生物转化研究,发现一种灰绿毛状GH-9菌株使人参皂苷Rb1有效地转化为C-K.经形态学和内转录间隔区(intemal transcribed spacer,ITS)基因序列分析,该菌株属于青霉属(Penicillium),且接近于Penicillium dipodomyicola.

  16. A subset of malignant phyllodes tumors harbors alterations in the Rb/p16 pathway

    OpenAIRE

    Cimino-Mathews, Ashley; Hicks, Jessica L.; Sharma, Rajni; Vang, Russell; Illei, Peter B; De Marzo, Angelo; Emens, Leisha A.; Argani, Pedram

    2013-01-01

    Breast phyllodes tumors are fibroepithelial neoplasms with variable risk of aggressive local recurrence and distant metastasis, and the molecular pathogenesis is unclear. Here, we systematically study p16 and Rb expression in 34 phyllodes tumors in relation to proliferation. Tissue microarrays were constructed from 10 benign, 10 borderline, and 14 malignant phyllodes (5 cores/tumor) and from 10 fibroadenomas (2 cores/tumor). Tissue microarrays were labeled by immunohistochemistry for p16, Rb,...

  17. Transcriptional activation by pRB and its coordination with SWI/SNF recruitment.

    Science.gov (United States)

    Flowers, Stephen; Beck, George R; Moran, Elizabeth

    2010-11-01

    A central question in cancer biology is why most tumor susceptibility genes are linked with only limited types of cancer. Human germ-line mutation of the retinoblastoma susceptibility gene Rb1 is closely linked with just retinoblastoma and osteosarcoma, although the gene is universally expressed. Functional analysis of pRB and its close relatives, p107 and p130, has largely focused on their roles in repression of proliferation across all tissue types, but genetic evidence indicates an active requirement for pRB in osteoblast differentiation that correlates more directly with osteosarcoma susceptibility. Still, potential promoter targets of pRB and its role in normally differentiating osteoblasts remain insufficiently characterized. Here, an early marker of osteoblast differentiation, alkaline phosphatase, is identified as a direct promoter activation target of pRB. One role of pRB on this promoter is to displace the histone lysine demethylase KDM5A, thereby favoring trimethylation of H3K4, a promoter activation mark. A major new aspect of pRB-mediated transcriptional activation revealed in this promoter analysis is its role in recruitment of an activating SWI/SNF chromatin-remodeling complex. SWI/SNF is a critical coordinator of tissue-specific gene expression. In osteoblasts, SWI/SNF complexes containing the BRM ATPase repress osteoblast-specific genes to maintain the precursor state, whereas the alternative ATPase BRG1 distinguishes an activating SWI/SNF complex necessary for RNA polymerase-II recruitment. A switch from BRM to BRG1 on the alkaline phosphatase promoter marks the onset of differentiation and is accomplished in a precise two-step mechanism. Dissociation of BRM-containing SWI/SNF depends on p300, and association of BRG1-containing SWI/SNF depends on pRB.

  18. HPV infection and the alterations of the pRB pathway in oral carcinogenesis.

    Science.gov (United States)

    Lim, Kue Peng; Hamid, Sharifah; Lau, Shin-Hin; Teo, Soo-Hwang; Cheong, Sok Ching

    2007-06-01

    Inactivation of the retinoblastoma (pRB) pathway is a common event in oral squamous cell carcinoma particularly through the aberrant expression of the components within this pathway. This study examines the alterations of molecules within the pRB pathway by looking at the presence of homozygous deletions in p16(INK4A) and the expression patterns of pRB, cyclin D1 and CDK4, as well as the presence of human papillomavirus (HPV) in our samples. In our study, 5/20 samples demonstrated deletions of p16(INK4A) exon 1alpha. pRB overexpression was found in 20/20 samples, the expression was mainly observed in all layers of the epithelia, particularly in the basal layer where cells are actively dividing and aberrant pRB expression was found in 12/20 samples. Cyclin D1 and CDK4 overexpression was detected in 6/20 and 2/20 samples respectively in comparison to hyperplasias where both proteins were either not expressed or expressed at minimal levels (pRB pathway, however, we did not find any significant relationship between the presence of HPV, homozygous deletion of p16(INK4A) and overexpression of pRB, cyclin D1 and CDK4. Collectively, this data demonstrates that alterations in the pRB pathway are a common event and involve the aberration of more than one molecule within the pathway. Furthermore, the involvement of HPV in all our samples suggests that HPV infection may play an important role in oral carcinogenesis.

  19. Mutational analysis of the RB1 gene and the inheritance patterns of retinoblastoma in Jordan.

    Science.gov (United States)

    Yousef, Yacoub A; Tbakhi, Abdelghani; Al-Hussaini, Maysa; AlNawaiseh, Ibrahim; Saab, Ala; Afifi, Amal; Naji, Maysa; Mohammad, Mona; Deebajah, Rasha; Jaradat, Imad; Sultan, Iyad; Mehyar, Mustafa

    2017-08-12

    Retinoblastoma (RB) is a childhood cancer developing in the retina due to RB1 pathologic variant. Herein we are evaluating the oncogenic mutations in the RB1 gene and the inheritance patterns of RB in the Jordanian patients. In this prospective study, the peripheral blood of 50 retinoblastoma patients was collected, genomic DNA was extracted, mutations were identified using Quantitative multiplex PCR (QM-PCR), Allele-specific PCR, Next Generation Sequencing analysis, and Sanger sequencing. In this cohort of 50 patients, 20(40%) patients had unilateral RB and 30(60%) were males. Overall, 36(72%) patients had germline disease, 17(47%) of whom had the same RB1 pathologic variant detected in one of the parents (inherited disease). In the bilateral group, all (100%) patients had germline disease; 13(43%) of them had inherited mutation. In the unilateral group, 6(30%) had germline disease, 4(20%) of them had inherited mutation. Nonsense mutation generating a stop codon and producing a truncated non-functional protein was the most frequent detected type of mutations (n = 15/36, 42%). Only one (2%) of the patients had mosaic mutation, and of the 17 inherited cases, 16(94%) had an unaffected carrier parent. In conclusion, in addition to all bilateral RB patients in our cohort, 30% of unilateral cases showed germline mutation. Almost half (47%) of germline cases had inherited disease from affected (6%) parent or unaffected carrier (94%). Therefore molecular screening is critical for the genetic counseling regarding the risk for inherited RB in both unilateral and bilateral cases including those with no family history.

  20. Rb and p53 Liver Functions Are Essential for Xenobiotic Metabolism and Tumor Suppression.

    Directory of Open Access Journals (Sweden)

    Sathidpak Nantasanti

    Full Text Available The tumor suppressors Retinoblastoma (Rb and p53 are frequently inactivated in liver diseases, such as hepatocellular carcinomas (HCC or infections with Hepatitis B or C viruses. Here, we discovered a novel role for Rb and p53 in xenobiotic metabolism, which represent a key function of the liver for metabolizing therapeutic drugs or toxins. We demonstrate that Rb and p53 cooperate to metabolize the xenobiotic 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC. DDC is metabolized mainly by cytochrome P450 (Cyp3a enzymes resulting in inhibition of heme synthesis and accumulation of protoporphyrin, an intermediate of heme pathway. Protoporphyrin accumulation causes bile injury and ductular reaction. We show that loss of Rb and p53 resulted in reduced Cyp3a expression decreased accumulation of protoporphyrin and consequently less ductular reaction in livers of mice fed with DDC for 3 weeks. These findings provide strong evidence that synergistic functions of Rb and p53 are essential for metabolism of DDC. Because Rb and p53 functions are frequently disabled in liver diseases, our results suggest that liver patients might have altered ability to remove toxins or properly metabolize therapeutic drugs. Strikingly the reduced biliary injury towards the oxidative stress inducer DCC was accompanied by enhanced hepatocellular injury and formation of HCCs in Rb and p53 deficient livers. The increase in hepatocellular injury might be related to reduce protoporphyrin accumulation, because protoporphrin is well known for its anti-oxidative activity. Furthermore our results indicate that Rb and p53 not only function as tumor suppressors in response to carcinogenic injury, but also in response to non-carcinogenic injury such as DDC.

  1. Rb and p53 gene deletions in lung adenocarcinomas from irradiated and control mice

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Woloschak, G.E. [Argonne National Lab., IL (United States). Center for Mechanistic Biology and Biotechnology

    1997-08-01

    This study was conducted on mouse lung adenocarcinoma tissues that were formalin-treated and paraffin-embedded 25 years ago to investigate the large gene deletions of mRb and p53 in B6CF{sub 1} male mice. A total of 80 lung tissue samples from irradiated mice and 40 lung samples from nonirradiated controls were randomly selected and examined in the mRb portion of this study. The results showed a significant (P < 0.05) higher percentage of mRb deletions in lung adenocarcinomas from mice exposed to 60 once-weekly {gamma}-ray doses than those from mice receiving 24 once-weekly {gamma}-ray doses at low doses and low dose rates; however, the percentage was not significantly different (P > 0.05) from that for spontaneous lung adenocarcinomas or lung adenocarcinomas from mice exposed to single-dose {gamma} irradiation at a similar total dose. mRb fragments 3 (71%) and 5 (67%), the parts of the gene that encoded the pocket binding region of Rb protein to adenovirus E1A and SV40 T-antigen, were the most frequently deleted fragments. p53 gene deletion analysis was carried out on normal lungs and lung adenocarcinomas that were initially found to bear mRb deletions. Exons 1,4,5,6, and 9 were chosen to be analyzed.

  2. Loss of pRB causes centromere dysfunction and chromosomal instability.

    Science.gov (United States)

    Manning, Amity L; Longworth, Michelle S; Dyson, Nicholas J

    2010-07-01

    Chromosome instability (CIN) is a common feature of tumor cells. By monitoring chromosome segregation, we show that depletion of the retinoblastoma protein (pRB) causes rates of missegregation comparable with those seen in CIN tumor cells. The retinoblastoma tumor suppressor is frequently inactivated in human cancers and is best known for its regulation of the G1/S-phase transition. Recent studies have shown that pRB inactivation also slows mitotic progression and promotes aneuploidy, but reasons for these phenotypes are not well understood. Here we describe the underlying mitotic defects of pRB-deficient cells that cause chromosome missegregation. Analysis of mitotic cells reveals that pRB depletion compromises centromeric localization of CAP-D3/condensin II and chromosome cohesion, leading to an increase in intercentromeric distance and deformation of centromeric structure. These defects promote merotelic attachment, resulting in failure of chromosome congression and an increased propensity for lagging chromosomes following mitotic delay. While complete loss of centromere function or chromosome cohesion would have catastrophic consequences, these more moderate defects allow pRB-deficient cells to proliferate but undermine the fidelity of mitosis, leading to whole-chromosome gains and losses. These observations explain an important consequence of RB1 inactivation, and suggest that subtle defects in centromere function are a frequent source of merotely and CIN in cancer.

  3. Inhibition of proliferation and induction of apoptosis in RB116 retinoblastoma cells by afatinib treatment.

    Science.gov (United States)

    Zhan, Wei-Jiao; Zhu, Jian-Feng; Wang, Long-Mei

    2016-07-01

    The present study investigates the effect of afatinib on the growth, induction of apoptosis in RB116 cells, and reduction of carcinoma growth in the mice transplanted with RB116 cells. The results from MTT assay revealed that afatinib inhibited the growth of RB116 cells in a dose-dependent manner. Proliferation of RB116 cells was reduced to 64 % on treatment with 200 μM concentration of afatinib after 48 h. Afatinib treatment of RB116 cells at 200 μM concentration induced apoptosis and necrosis in 49.7 and 9.4 %, respectively, after 48 h. In the RB116-transplanted mice, treatment with afatinib at 10-mg/kg doses for 45 days caused a significant (p afatinib treatment group after 45 days. However, the expression of caspase-3 was increased and of Bcl-2 remained unaltered on treatment with afatinib. Measurement of the body weight of afatinib-treated animals showed no reduction during the study. Thus, afatinib can be of therapeutic value for the treatment of retinoblastoma.

  4. Rb suppresses collective invasion, circulation and metastasis of breast cancer cells in CD44-dependent manner.

    Directory of Open Access Journals (Sweden)

    Kui-Jin Kim

    Full Text Available Basal-like breast carcinomas (BLCs present with extratumoral lymphovascular invasion, are highly metastatic, presumably through a hematogenous route, have augmented expression of CD44 oncoprotein and relatively low levels of retinoblastoma (Rb tumor suppressor. However, the causal relation among these features is not clear. Here, we show that Rb acts as a key suppressor of multiple stages of metastatic progression. Firstly, Rb suppresses collective cell migration (CCM and CD44-dependent formation of F-actin positive protrusions in vitro and cell-cluster based lymphovascular invasion in vivo. Secondly, Rb inhibits the release of single cancer cells and cell clusters into the hematogenous circulation and subsequent metastatic growth in lungs. Finally, CD44 expression is required for collective motility and all subsequent stages of metastatic progression initiated by loss of Rb function. Altogether, our results suggest that Rb/CD44 pathway is a crucial regulator of CCM and metastatic progression of BLCs and a promising target for anti-BLCs therapy.

  5. The tumor suppressor Rb and its related Rbl2 genes are regulated by Utx histone demethylase

    Energy Technology Data Exchange (ETDEWEB)

    Terashima, Minoru; Ishimura, Akihiko; Yoshida, Masakazu [Division of Functional Genomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Ishikawa (Japan); Suzuki, Yutaka; Sugano, Sumio [Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Chiba (Japan); Suzuki, Takeshi, E-mail: suzuki-t@staff.kanazawa-u.ac.jp [Division of Functional Genomics, Cancer Research Institute, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Ishikawa (Japan)

    2010-08-20

    Research highlights: {yields} Utx increases expression of Rb and Rbl2 genes through its demethylase activity. {yields} Utx changes histone H3 methylation on the Rb and Rbl2 promoters. {yields} Utx induces decreased cell proliferation of mammalian primary cells. -- Abstract: Utx is a candidate tumor suppressor gene that encodes histone H3 lysine 27 (H3K27) demethylase. In this study, we found that ectopic expression of Utx enhanced the expression of retinoblastoma tumor suppressor gene Rb and its related gene Rbl2. This activation was dependent on the demethylase activity of Utx, and was suggested to contribute to the decreased cell proliferation induced by Utx. A chromatin immunoprecipitation assay showed that over-expressed Utx was associated with the promoter regions of Rb and Rbl2 resulting in the removal of repressive H3K27 tri-methylation and the increase in active H3K4 tri-methylation. Furthermore, siRNA-mediated knockdown of Utx revealed the recruitment of endogenous Utx protein on the promoters of Rb and Rbl2 genes. These results indicate that Rb and Rbl2 are downstream target genes of Utx and may play important roles in Utx-mediated cell growth control.

  6. Ginsenoside Rb1 Protects Rat Neural Progenitor Cells against Oxidative Injury

    Directory of Open Access Journals (Sweden)

    Na Ni

    2014-03-01

    Full Text Available Ginseng, the root of Panax ginseng C.A. Meyer, has been used as a tonic to enhance bodily functions against various ailments for hundreds of years in Far Eastern countries without apparent adverse effects. Ginsenoside Rb1, one of the most active ingredients of ginseng, has been shown to possess various pharmacological activities. Here we report that Rb1 exhibits potent neuroprotective effects against oxidative injury induced by tert-butylhydroperoxide (t-BHP. Lactate dehydrogenase (LDH assay demonstrated that incubation with 300 µm t-BHP for 2.5 h led to a significant cell loss of cultured rat embryonic cortex-derived neural progenitor cells (NPCs and the cell viability was pronouncedly increased by 24 h pretreatment of 10 µm Rb1. TUNEL staining further confirmed that pretreatment of Rb1 significantly reduced the cell apoptosis in t-BHP-induced oxidative injury. Real time PCR revealed that pretreatment with Rb1 activated Nrf2 pathway in cultured NPCs and led to an elevated expression of HO-1. The results of the present study demonstrate that Rb1 shows a potent anti-oxidative effect on cultured NPCs by activating Nrf2 pathway.

  7. The environmental impact of recombinant bovine somatotropin (rbST) use in dairy production.

    Science.gov (United States)

    Capper, Judith L; Castañeda-Gutiérrez, Euridice; Cady, Roger A; Bauman, Dale E

    2008-07-15

    The environmental impact of using recombinant bovine somatotropin (rbST) in dairy production was examined on an individual cow, industry-scale adoption, and overall production system basis. An average 2006 U.S. milk yield of 28.9 kg per day was used, with a daily response to rbST supplementation of 4.5 kg per cow. Rations were formulated and both resource inputs (feedstuffs, fertilizers, and fuels) and waste outputs (nutrient excretion and greenhouse gas emissions) calculated. The wider environmental impact of production systems was assessed via acidification (AP), eutrophication (EP), and global warming (GWP) potentials. From a producer perspective, rbST supplementation improved individual cow production, with reductions in nutrient input and waste output per unit of milk produced. From an industry perspective, supplementing one million cows with rbST reduced feedstuff and water use, cropland area, N and P excretion, greenhouse gas emissions, and fossil fuel use compared with an equivalent milk production from unsupplemented cows. Meeting future U.S. milk requirements from cows supplemented with rbST conferred the lowest AP, EP, and GWP, with intermediate values for conventional management and the highest environmental impact resulting from organic production. Overall, rbST appears to represent a valuable management tool for use in dairy production to improve productive efficiency and to have less negative effects on the environment than conventional dairying.

  8. Resistance to Phytophthora infestans EC-1 clonal lineage in Solanum tuberosum by introducing the RB gene

    Directory of Open Access Journals (Sweden)

    María Lupe Román

    2015-04-01

    Full Text Available One of the most efficient options for the control of late blight disease in potato (Solanum tuberosum is the development of resistant varieties to Phytophthora infestans mediated by the direct transfer of resistance (R genes through genetic engineering. In the present work, we used Solanum bulbocastanum RB gene to confers broad spectrum resistance to P. infestans races. To that end, Agrobacterium - mediated genetic transformation was used to transform a susceptible potato variety, Desiree, with the binary vector pCIP68 harboring the RB gene. As a result, 19 transformed plants containing the RB gene were obtained. kanamycin resistance test and polymerase chain reaction (PCR assays confirmed the integration of the T-DNA in the potato genome. The 19 transformed plants, also called transgenic events were subjected to infection under biosafety greenhouse conditions. Phytophthora infestans isolate POX067 of the EC-1 clonal lineage, commonly find in Peru, was used for the infection. Three of the 19 plants ([RB]54, [RB]56 and [RB]70 show high resistance levels to isolate POX067 of P. infestans.

  9. Brucella abortus Strain RB51 Vaccine: Immune Response after Calfhood Vaccination and Field Investigation in Italian Cattle Population

    Directory of Open Access Journals (Sweden)

    Manuela Tittarelli

    2008-01-01

    Full Text Available Immune response to Brucella abortus strain RB51 vaccine was measured in cattle vaccinated at calfhood. After an increase at day 6 post-vaccination (pv, the antibody level recorded in the 10 vaccinated animals remained constant for two months, and then progressively decreased. All vaccinated animals remained negative from day 162 pv to the end of the study (day 300 pv. Only at days 13 and 14 pv the RB51-CFT showed 100% sensitivity (credibility interval (CI 76.2%–100%. The results indicate that the possibility to use RB51-CFT for the identification of cattle vaccinated at calfhood with RB51 is limited in time. A field investigation was carried out on 26,975 sera collected on regional basis from the Italian cattle population. The study outcomes indicate that in case of RB51-CFT positive results observed in officially Brucellosis-free (OBF areas and, in any case, when an illegal use of RB51 vaccine is suspected, the use of the RB51-CFT alone is not sufficient to identify all the vaccinated animals. The design of a more sophisticated diagnostic protocol including an epidemiological investigation, the use of RB51-CFT, and the use of the skin test with RB51 as antigen is deemed more appropriate for the identification of RB51 vaccinated animals.

  10. An accurate Rb density measurement method for a plasma wakefield accelerator experiment using a novel Rb reservoir

    CERN Document Server

    Öz, E; Muggli, P

    2016-01-01

    A method to accurately measure the density of Rb vapor is described. We plan on using this method for the Advanced Wakefield (AWAKE)~\\cite{bib:awake} project at CERN , which will be the world's first proton driven plasma wakefield experiment. The method is similar to the hook~\\cite{bib:Hook} method and has been described in great detail in the work by W. Tendell Hill et. al.~\\cite{bib:densitymeter}. In this method a cosine fit is applied to the interferogram to obtain a relative accuracy on the order of $1\\%$ for the vapor density-length product. A single-mode, fiber-based, Mach-Zenhder interferometer will be built and used near the ends of the 10 meter-long AWAKE plasma source to be able to make accurate relative density measurement between these two locations. This can then be used to infer the vapor density gradient along the AWAKE plasma source and also change it to the value desired for the plasma wakefield experiment. Here we describe the plan in detail and show preliminary results obtained using a prot...

  11. Multiple protein biomarker assessment for recombinant bovine somatotropin (rbST abuse in cattle.

    Directory of Open Access Journals (Sweden)

    Susann K J Ludwig

    Full Text Available Biomarker profiling, as a rapid screening approach for detection of hormone abuse, requires well selected candidate biomarkers and a thorough in vivo biomarker evaluation as previously done for detection of growth hormone doping in athletes. The bovine equivalent of growth hormone, called recombinant bovine somatotropin (rbST is (illegally administered to enhance milk production in dairy cows. In this study, first a generic sample pre-treatment and 4-plex flow cytometric immunoassay (FCIA were developed for simultaneous measurement of four candidate biomarkers selected from literature: insulin-like growth factor 1 (IGF-1, its binding protein 2 (IGFBP2, osteocalcin and endogenously produced antibodies against rbST. Next, bovine serum samples from two extensive controlled rbST animal treatment studies were used for in vivo validation and biomarker evaluation. Finally, advanced statistic tools were tested for the assessment of biomarker combination quality aiming to correctly identify rbST-treated animals. The statistical prediction tool k-nearest neighbours using a combination of the biomarkers osteocalcin and endogenously produced antibodies against rbST proved to be very reliable and correctly predicted 95% of the treated samples starting from the second rbST injection until the end of the treatment period and even thereafter. With the same biomarker combination, only 12% of untreated animals appeared false-positive. This reliability meets the requirements of Commission Decision 2002/657/EC for screening methods in veterinary control. From the results of this multidisciplinary study, it is concluded that the osteocalcin - anti-rbST-antibodies combination represent fit-for-purpose biomarkers for screening of rbST abuse in dairy cattle and can be reliably measured in both the developed 4-plex FCIA as well as in a cost-effective 2-plex microsphere-based binding assay. This screening method can be incorporated in routine veterinary monitoring

  12. Interaction of antiprotons with Rb atoms and a comparison of antiproton stopping powers of the atoms H, Li, Na, K, and Rb

    DEFF Research Database (Denmark)

    Lühr, Armin Christian; Fischer, Nicolas; Saenz, Alejandro

    2009-01-01

    Ionization and excitation cross sections as well as electron-energy spectra and stopping powers of the alkali metal atoms Li, Na, K, and Rb colliding with antiprotons were calculated using a time-dependent channel-coupling approach. An impact-energy range from 0.25 to 4000 keV was considered. The...

  13. Spin depolarization of N{sub 2}{sup +} ({sup 2}{sigma}{sup +}) in collisions with {sup 3}He in a magnetic field: general behaviour and zero energy Feshbach resonances

    Energy Technology Data Exchange (ETDEWEB)

    Guillon, G; Stoecklin, T [Institut des Sciences Moleculaires, CNRS-UMR 5255, 351 cours de la Liberation 33405 Talence (France); Voronin, A [Institute of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow 142432 (Russian Federation)], E-mail: t.stoecklin@ism.u-bordeaux1.fr

    2009-10-15

    We give a brief account of the effect of a magnetic field on the spin-depolarization cross sections of N{sub 2}{sup +}({sup 2}{sigma}) in collisions with {sup 3}He at very low collision energy. The fundamental states of the two nuclear spin isomers of N{sub 2}{sup +} are shown to respond quite differently to the application of the field. When the applied magnetic field increases, the spin depolarization cross sections are found to monotonously decrease for the fundamental para level N=0 of N{sub 2}{sup +}, whereas they monotonously increase for the fundamental ortho level N=1 of N{sub 2}{sup +}. This effect is found to be amplified around the resonances and an explanation based on the different mechanism of spin flipping acting for these two levels is proposed. We also explore the tuning of zero energy Feshbach resonances by examining the variation of the scattering length as a function of the magnetic field. We use the Smith Q matrix to calculate the lifetimes of the complexes associated with these resonances and discuss the law of variation as a function of the magnetic field of the Q matrix eigenvalues across such resonances.

  14. Some calculated (p,α) cross-sections using the alpha particle knock-on and triton pick-up reaction mechanisms: An optimisation of the single-step Feshbach-Kerman-Koonin (FKK) theory

    Energy Technology Data Exchange (ETDEWEB)

    Olise, Felix S.; Ajala, Afis; Olamiyl, Hezekiah B. [Dept. of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife (Nigeria)

    2016-04-15

    The Feshbach-Kerman-Koonin (FKK) multi-step direct (MSD) theory of pre-equilibrium reactions has been used to compute the single-step cross-sections for some (p,α) reactions using the knock-on and pick-up reaction mechanisms at two incident proton energies. For the knock-on mechanism, the reaction was assumed to have taken place by the direct ejection of a preformed alpha cluster in a shell-model state of the target. But the reaction was assumed to have taken place by the pick-up of a preformed triton cluster (also bound in a shell-model state of the target core) by the incident proton for the pick-up mechanism. The Yukawa forms of potential were used for the proton-alpha (for the knock-on process) and proton-triton (for the pick-up process) interaction and several parameter sets for the proton and alpha-particle optical potentials. The calculated cross-sections for both mechanisms gave satisfactory fits to the experimental data. Furthermore, it has been shown that some combinations of the calculated distorted wave Born approximation cross-sections for the two reaction mechanisms in the FKK MSD theory are able to give better fits to the experimental data, especially in terms of range of agreement. In addition, the theory has been observed to be valid over a wider range of energy.

  15. Feshbach resonances in the exit channel of the F + CH3OH → HF + CH3O reaction observed using transition-state spectroscopy

    Science.gov (United States)

    Weichman, Marissa L.; Devine, Jessalyn A.; Babin, Mark C.; Li, Jun; Guo, Lifen; Ma, Jianyi; Guo, Hua; Neumark, Daniel M.

    2017-10-01

    The transition state governs how chemical bonds form and cleave during a chemical reaction and its direct characterization is a long-standing challenge in physical chemistry. Transition state spectroscopy experiments based on negative-ion photodetachment provide a direct probe of the vibrational structure and metastable resonances that are characteristic of the reactive surface. Dynamical resonances are extremely sensitive to the topography of the reactive surface and provide an exceptional point of comparison with theory. Here we study the seven-atom F + CH3OH → HF + CH3O reaction using slow photoelectron velocity-map imaging spectroscopy of cryocooled CH3OHF‑ anions. These measurements reveal spectral features associated with a manifold of vibrational Feshbach resonances and bound states supported by the post-transition state potential well. Quantum dynamical calculations yield excellent agreement with the experimental results, allow the assignment of spectral structure and demonstrate that the key dynamics of complex bimolecular reactions can be captured with a relatively simple theoretical framework.

  16. Ginseng Rb fraction protects glia, neurons and cognitive function in a rat model of neurodegeneration.

    Directory of Open Access Journals (Sweden)

    Kangning Xu

    Full Text Available The loss and injury of neurons play an important role in the onset of various neurodegenerative diseases, while both microgliosis and astrocyte loss or dysfunction are significant causes of neuronal degeneration. Previous studies have suggested that an extract enriched panaxadiol saponins from ginseng has more neuroprotective potential than the total saponins of ginseng. The present study investigated whether a fraction of highly purified panaxadiol saponins (termed as Rb fraction was protective for both glia and neurons, especially GABAergic interneurons, against kainic acid (KA-induced excitotoxicity in rats. Rats received Rb fraction at 30 mg/kg (i.p., 40 mg/kg (i.p. or saline followed 40 min later by an intracerebroventricular injection of KA. Acute hippocampal injury was determined at 48 h after KA, and impairment of hippocampus-dependent learning and memory as well as delayed neuronal injury was determined 16 to 21 days later. KA injection produced significant acute hippocampal injuries, including GAD67-positive GABAergic interneuron loss in CA1, paralbumin (PV-positive GABAergic interneuron loss, pyramidal neuron degeneration and astrocyte damage accompanied with reactive microglia in both CA1 and CA3 regions of the hippocampus. There was also a delayed loss of GAD67-positive interneurons in CA1, CA3, hilus and dentate gyrus. Microgliosis also became more severe 21 days later. Accordingly, KA injection resulted in hippocampus-dependent spatial memory impairment. Interestingly, the pretreatment with Rb fraction at 30 or 40 mg/kg significantly protected the pyramidal neurons and GABAergic interneurons against KA-induced acute excitotoxicity and delayed injury. Rb fraction also prevented memory impairments and protected astrocytes from KA-induced acute excitotoxicity. Additionally, microglial activation, especially the delayed microgliosis, was inhibited by Rb fraction. Overall, this study demonstrated that Rb fraction protected both

  17. Oral absorption of ginsenoside Rb1 using in vitro and in vivo models.

    Science.gov (United States)

    Han, Min; Sha, Xianyi; Wu, Yunjuan; Fang, Xiaoling

    2006-04-01

    This research attempts to clarify the cause for poor oral absorption of ginsenoside Rb1 (Rb1), one main ingredient of the well known Panax notoginseng saponins (PNS) for curing hemorrhage. Caco-2 cell monolayers were used as an in vitro model to reveal the transport mechanism of Rb1 across the intestinal mucosa. Moreover, the serum concentration-time profiles of Rb1 after tail venous (IV), portal venous (PV), intraduodenal (ID) and peroral (PO) administration to rats were compared to evaluate the first-pass effects of stomach, intestine and liver. In vitro experiments showed that uptake by Caco-2 cell monolayers was temperature dependent, but was not influenced by cyclosporine A and ketoconazole. The change in the apical pH showed no obvious effects on the uptake of Rb1. The uptake and transport were non-saturable, and flux from the apical compartment to the basolateral compartment (A-B) increased linearly with increasing concentration, which indicated a passive transport. Meanwhile, an apparent permeability coefficient of (5.90 +/- 1.02) x 10(-8) cm/s (C0 = 1 mg/mL) predicted an incomplete absorption. The investigation on the pharmacokinetic behavior of Rb1 after different routes of administration to rats showed a significant difference between PO (F(PO) was 0.64%), ID (F(ID) was 2.46%) and PV (F(PV) was 59.49%) administration, and the first-pass effect of the intestine is more significant than that of the stomach and liver in the absorption process. In summary, elimination in the stomach, large intestine and liver contributed to the poor absorption of Rb1, but the low membrane permeability might be a more important factor dominating the extent of absorption.

  18. Role of Rb during Neurogenesis and Axonal Guidance in the Developing Olfactory System

    Science.gov (United States)

    Jaafar, Carine; Omais, Saad; Al Lafi, Sawsan; El Jamal, Nadim; Noubani, Mohammad; Skaf, Larissa; Ghanem, Noël

    2016-01-01

    The Retinoblastoma protein, Rb, was shown to regulate distinct aspects of neurogenesis in the embryonic and adult brain besides its primary role in cell cycle control. It is still unknown, however, whether Rb is required for tissue morphogenesis and the establishment of synaptic connections between adjacent tissues during development. We have investigated here the role of Rb during development of the olfactory system (OS), which heavily relies on reciprocal interactions between the olfactory epithelium (OE) and the olfactory bulb (OB). We show that mice carrying a telencephalic-specific deletion of Rb display several neurogenic defects in the OS during late development. In the OE, loss of Rb leads to ectopic proliferation of late-born progenitors (Tuj-1+), abnormal radial migration and terminal maturation of olfactory sensory neurons (OSNs). In the OB, deletion of Rb causes severe lamination defects with loss of clear boundaries between distinct layers. Importantly, starting around E15.5 when OB glomerulogenesis is initiated, many OSNs axons that project along the olfactory nerve layer (ONL) fail to properly innervate the nascent bulb, thus resulting in partial loss of connectivity between OE-OB and gradual neuronal degeneration in both tissues peaking at birth. This deficiency correlates with deregulated expressions of two key chemo-repellant molecules, Robo2/Slit1 and Nrp2/Sema3F that control the formation of dorsal-ventral topographic map of OSNs connections with OB glomeruli. This study highlights a critical requirement for Rb during neurogenesis and the establishment of proper synaptic connections inside the OS during development. PMID:27667971

  19. Ginseng Rb fraction protects glia, neurons and cognitive function in a rat model of neurodegeneration.

    Science.gov (United States)

    Xu, Kangning; Zhang, Yufen; Wang, Yan; Ling, Peng; Xie, Xin; Jiang, Chenyao; Zhang, Zhizhen; Lian, Xiao-Yuan

    2014-01-01

    The loss and injury of neurons play an important role in the onset of various neurodegenerative diseases, while both microgliosis and astrocyte loss or dysfunction are significant causes of neuronal degeneration. Previous studies have suggested that an extract enriched panaxadiol saponins from ginseng has more neuroprotective potential than the total saponins of ginseng. The present study investigated whether a fraction of highly purified panaxadiol saponins (termed as Rb fraction) was protective for both glia and neurons, especially GABAergic interneurons, against kainic acid (KA)-induced excitotoxicity in rats. Rats received Rb fraction at 30 mg/kg (i.p.), 40 mg/kg (i.p. or saline followed 40 min later by an intracerebroventricular injection of KA. Acute hippocampal injury was determined at 48 h after KA, and impairment of hippocampus-dependent learning and memory as well as delayed neuronal injury was determined 16 to 21 days later. KA injection produced significant acute hippocampal injuries, including GAD67-positive GABAergic interneuron loss in CA1, paralbumin (PV)-positive GABAergic interneuron loss, pyramidal neuron degeneration and astrocyte damage accompanied with reactive microglia in both CA1 and CA3 regions of the hippocampus. There was also a delayed loss of GAD67-positive interneurons in CA1, CA3, hilus and dentate gyrus. Microgliosis also became more severe 21 days later. Accordingly, KA injection resulted in hippocampus-dependent spatial memory impairment. Interestingly, the pretreatment with Rb fraction at 30 or 40 mg/kg significantly protected the pyramidal neurons and GABAergic interneurons against KA-induced acute excitotoxicity and delayed injury. Rb fraction also prevented memory impairments and protected astrocytes from KA-induced acute excitotoxicity. Additionally, microglial activation, especially the delayed microgliosis, was inhibited by Rb fraction. Overall, this study demonstrated that Rb fraction protected both astrocytes and neurons

  20. Quantification of myocardial blood flow with {sup 82}Rb dynamic PET imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lortie, Mireille; Beanlands, Rob S.B.; Yoshinaga, Keiichiro; Klein, Ran; DaSilva, Jean N.; DeKemp, Robert A. [University of Ottawa Heart Institute, Cardiac PET Centre, Ottawa, ON (Canada)

    2007-11-15

    The PET tracer {sup 82}Rb is commonly used to evaluate regional perfusion defects for the diagnosis of coronary artery disease. There is limited information on the quantification of myocardial blood flow and flow reserve with this tracer. The goal of this study was to investigate the use of a one-compartment model of {sup 82}Rb kinetics for the quantification of myocardial blood flow. Fourteen healthy volunteers underwent rest and dipyridamole stress imaging with both {sup 13}N-ammonia and {sup 82}Rb within a 2-week interval. Myocardial blood flow was estimated from the time-activity curves measured with {sup 13}N-ammonia using a standard two-compartment model. The uptake parameter of the one-compartment model was estimated from the time-activity curves measured with {sup 82}Rb. To describe the relationship between myocardial blood flow and the uptake parameter, a nonlinear extraction function was fitted to the data. This function was then used to convert estimates of the uptake parameter to flow estimates. The extraction function was validated with an independent data set obtained from 13 subjects with documented evidence of coronary artery disease (CAD). The one-compartment model described {sup 82}Rb kinetics very well (median R-square = 0.98). The flow estimates obtained with {sup 82}Rb were well correlated with those obtained with {sup 13}N-ammonia (r = 0.85), and the best-fit line did not differ significantly from the identity line. Data obtained from the subjects with CAD confirmed the validity of the estimated extraction function. It is possible to obtain accurate estimates of myocardial blood flow and flow reserve with a one-compartment model of {sup 82}Rb kinetics and a nonlinear extraction function. (orig.)

  1. 5-Aza-2'-deoxycytidine reactivates gene expression via degradation of pRb pocket proteins.

    Science.gov (United States)

    Zheng, Zhixing; Li, Lian; Liu, Xiangyu; Wang, Donglai; Tu, Bo; Wang, Lina; Wang, Haiying; Zhu, Wei-Guo

    2012-01-01

    Not only does 5-aza-2'-deoxycytidine (5-aza-CdR) induce the reexpression of silenced genes through the demethylation of CpG islands, but it increases the expression of unmethylated genes. However, the mechanism by which 5-aza-CdR activates the expression of genes is not completely understood. Here, we report that the pRb pocket proteins pRb, p107, and p130 were degraded in various cancer cell lines in response to 5-aza-CdR treatment, and this effect was dependent on the proteasome pathway. Mouse double minute 2 (MDM2) played a critical role in this 5-aza-CdR-induced degradation of pRb. Furthermore, PP2A phosphatase-induced MDM2 dephosphorylation at S260 was found to be essential for MDM2 binding to pRb in the presence of 5-aza-CdR. pRb degradation resulted in the significant reexpression of several genes, including methylated CDKN2A, RASFF1A, and unmethylated CDKN2D. Finally, knockdown of pRb pocket proteins by either RNAi or 5-aza-CdR treatment induced a significant decrease in the recruitment of SUV39H1 and an increase in the enrichment of KDM3B and KDM4A to histones around the promoter of RASFF1A and thus reduced H3K9 di- and trimethylation, by which RASFF1A expression is activated. Our data reveal a novel mechanism by which 5-aza-CdR induces the expression of both methylated and unmethylated genes by degrading pRb pocket proteins.

  2. RB1 status in triple negative breast cancer cells dictates response to radiation treatment and selective therapeutic drugs.

    Science.gov (United States)

    Robinson, Tyler J W; Liu, Jeff C; Vizeacoumar, Frederick; Sun, Thomas; Maclean, Neil; Egan, Sean E; Schimmer, Aaron D; Datti, Alessandro; Zacksenhaus, Eldad

    2013-01-01

    Triple negative breast cancer (TNBC) includes basal-like and claudin-low subtypes for which only chemotherapy and radiation therapy are currently available. The retinoblastoma (RB1) tumor suppressor is frequently lost in human TNBC. Knockdown of RB1 in luminal BC cells was shown to affect response to endocrine, radiation and several antineoplastic drugs. However, the effect of RB1 status on radiation and chemo-sensitivity in TNBC cells and whether RB1 status affects response to divergent or specific treatment are unknown. Using multiple basal-like and claudin-low cell lines, we hereby demonstrate that RB-negative TNBC cell lines are highly sensitive to gamma-irradiation, and moderately more sensitive to doxorubicin and methotrexate compared to RB-positive TNBC cell lines. In contrast, RB1 status did not affect sensitivity of TNBC cells to multiple other drugs including cisplatin (CDDP), 5-fluorouracil, idarubicin, epirubicin, PRIMA-1(met), fludarabine and PD-0332991, some of which are used to treat TNBC patients. Moreover, a non-biased screen of ∼3400 compounds, including FDA-approved drugs, revealed similar sensitivity of RB-proficient and -deficient TNBC cells. Finally, ESA(+)/CD24(-/low)/CD44(+) cancer stem cells from RB-negative TNBC lines were consistently more sensitive to gamma-irradiation than RB-positive lines, whereas the effect of chemotherapy on the cancer stem cell fraction varied irrespective of RB1 expression. Our results suggest that patients carrying RB-deficient TNBCs would benefit from gamma-irradiation as well as doxorubicin and methotrexate therapy, but not necessarily from many other anti-neoplastic drugs.

  3. RB1 status in triple negative breast cancer cells dictates response to radiation treatment and selective therapeutic drugs.

    Directory of Open Access Journals (Sweden)

    Tyler J W Robinson

    Full Text Available Triple negative breast cancer (TNBC includes basal-like and claudin-low subtypes for which only chemotherapy and radiation therapy are currently available. The retinoblastoma (RB1 tumor suppressor is frequently lost in human TNBC. Knockdown of RB1 in luminal BC cells was shown to affect response to endocrine, radiation and several antineoplastic drugs. However, the effect of RB1 status on radiation and chemo-sensitivity in TNBC cells and whether RB1 status affects response to divergent or specific treatment are unknown. Using multiple basal-like and claudin-low cell lines, we hereby demonstrate that RB-negative TNBC cell lines are highly sensitive to gamma-irradiation, and moderately more sensitive to doxorubicin and methotrexate compared to RB-positive TNBC cell lines. In contrast, RB1 status did not affect sensitivity of TNBC cells to multiple other drugs including cisplatin (CDDP, 5-fluorouracil, idarubicin, epirubicin, PRIMA-1(met, fludarabine and PD-0332991, some of which are used to treat TNBC patients. Moreover, a non-biased screen of ∼3400 compounds, including FDA-approved drugs, revealed similar sensitivity of RB-proficient and -deficient TNBC cells. Finally, ESA(+/CD24(-/low/CD44(+ cancer stem cells from RB-negative TNBC lines were consistently more sensitive to gamma-irradiation than RB-positive lines, whereas the effect of chemotherapy on the cancer stem cell fraction varied irrespective of RB1 expression. Our results suggest that patients carrying RB-deficient TNBCs would benefit from gamma-irradiation as well as doxorubicin and methotrexate therapy, but not necessarily from many other anti-neoplastic drugs.

  4. p16 controls epithelial cell growth and suppresses carcinogenesis through mechanisms that do not require RB1 function

    Science.gov (United States)

    Sen, M; Akeno, N; Reece, A; Miller, A L; Simpson, D S; Wikenheiser-Brokamp, K A

    2017-01-01

    The p16/RB1 tumor suppressor pathway is inactivated in the vast majority, if not all, human cancers. The current paradigm is that p16 and RB1 function in a linear pathway to suppress tumorigenesis; however p16 is preferentially lost in human cancers suggesting that p16 has critical tumor suppressive functions not mediated through RB1. Carcinomas arise from transformed epithelial cells and account for 80% of adult malignancies highlighting the need to understand p16/RB1 pathway function in organ epithelia. Lung cancer is the leading cause of cancer deaths and is associated with p16/RB1 pathway deregulation. We demonstrate that p16 is upregulated in the lung epithelium after Rb1 ablation in genetically engineered mouse models. In contrast to fibroblasts, loss of RB1 family proteins, p107 or p130, did not result in p16 induction, demonstrating that p16 suppression is a unique RB1 pocket protein function in the lung epithelium in vivo. p16 upregulation did not induce cellular senescence but rather promoted survival of RB1-deficient lung epithelial progenitor cells. Mechanistic studies show that p16 protects RB1-deficient cells from DNA damage. Consequently, additional loss of p16 led to genetic instability and increased susceptibility to cellular immortalization and transformation. Mice with combined RB1/p16-deficient lungs developed lung tumors including aggressive metastatic lung cancers. These studies identify p16 loss as a molecular event that causes genetic instability and directly demonstrate that p16 protects against DNA damage in the absence of RB1 function providing an explanation for why p16 is preferentially targeted in human cancers. PMID:28414317

  5. pRB-E2F1 complexes are resistant to adenovirus E1A-mediated disruption.

    Science.gov (United States)

    Seifried, L A; Talluri, S; Cecchini, M; Julian, L M; Mymryk, J S; Dick, F A

    2008-05-01

    Disruption of pRB-E2F interactions by E1A is a key event in the adenoviral life cycle that drives expression of early viral transcription and induces cell cycle progression. This function of E1A is complicated by E2F1, an E2F family member that controls multiple processes besides proliferation, including apoptosis and DNA repair. Recently, a second interaction site in pRB that only contacts E2F1 has been discovered, allowing pRB to control proliferation separately from other E2F1-dependent activities. Based on this new insight into pRB-E2F1 regulation, we investigated how E1A affects control of E2F1 by pRB. Our data reveal that pRB-E2F1 interactions are resistant to E1A-mediated disruption. Using mutant forms of pRB that selectively force E2F1 to bind through only one of the two binding sites on pRB, we determined that E1A is unable to disrupt E2F1's unique interaction with pRB. Furthermore, analysis of pRB-E2F complexes during adenoviral infection reveals the selective maintenance of pRB-E2F1 interactions despite the presence of E1A. Our experiments also demonstrate that E2F1 functions to maintain cell viability in response to E1A expression. This suggests that adenovirus E1A's seemingly complex mechanism of disrupting pRB-E2F interactions provides selectivity in promoting viral transcription and cell cycle advancement, while maintaining cell viability.

  6. pRb phosphorylation regulates the proliferation of supporting cells in gentamicin-damaged neonatal avian utricle.

    Science.gov (United States)

    Wu, Jingfang; Sun, Shan; Li, Wenyan; Chen, Yan; Li, Huawei

    2014-10-01

    The ability of nonmammalian vertebrates to regenerate hair cells (HCs) after damage-induced HC loss has stimulated and inspired research in the field of HC regeneration. The protein pRb encoded by retinoblastoma gene Rb1 forces sensory progenitor cells to exit cell cycle and maintain differentiated HCs and supporting cells (SCs) in a quiescent state. pRb function is regulated by phosphorylation through the MEK/ERK or the pRb/Raf-1 signaling pathway. In our previous study, we have shown that pRb phosphorylation is crucial for progenitor cell proliferation and survival during the early embryonic stage of avian otocyst sensory epithelium development. However, in damaged avian utricle, the role of pRb in regulating the cell cycling of SCs or HCs regeneration still remains unclear. To further elucidate the function of pRb phosphorylation on SCs re-entering the cell cycle triggered by gentamycin-induced HCs damage, we isolated neonatal chicken utricles and treated them with the MEK inhibitor U0126 or the pRb/Raf-1 inhibitor RRD-251, respectively in vitro. We found that after gentamycin-induced HCs damage, pRb phosphorylation is important for the quiescent SCs re-entering the cell cycle in the neonatal chicken utricle. In addition, the proliferation of SCs decreased in a dose-dependent manner in response to both U0126 and RRD-251, which indicates that both the MEK/ERK and the pRb/Raf-1 signaling pathway play important roles in pRb phosphorylation in damaged neonatal chicken utricle. Together, these findings on the function of pRb in damaged neonatal chicken utricle improve our understanding of the regulation of the cell cycle of SCs after HCs loss and may shed light on the mammalian HC regeneration from SCs in damaged organs.

  7. Staurosporine is chemoprotective by inducing G1 arrest in a Chk1- and pRb-dependent manner.

    Science.gov (United States)

    Murray, Mollianne McGahren; Bui, Tuyen; Smith, Michelle; Bagheri-Yarmand, Rozita; Wingate, Hannah; Hunt, Kelly K; Keyomarsi, Khandan

    2013-10-01

    Chemotherapeutic agents have been the mainstay of cancer therapy for years. However, their effectiveness has been limited by toxicities they impart on normal cells. Staurosporine (ST) has been shown to arrest normal, but not breast cancer, cells in G1. Therefore, ST may become a chemoprotective agent, arresting normal cells while allowing tumor cells to enter cell cycle phases where they are sensitive to chemotherapeutic agents. Understanding the mechanism of ST-mediated G1 arrest may allow for a beneficial chemoprotective treatment strategy for patients. We utilized 76NE6 (pRb+/p53-), 76NF2V (pRb+/p53+) and 76NE7 (pRb-/P53+) non-tumorigenic human mammary epithelial cell lines to understand the role of the Rb and p53 pathways in ST-directed G1 arrest. CDK4 was downregulated by ST in Rb+ cells, but its presence could not reverse the arrest, neither did its stable downregulation alter ST-mediated cellular response. ST-mediated G1 arrest required pRb, which in turn initiated a cascade of events leading to inhibition of CDK4. Further assessment of this pathway revealed that Chk1 expression and activity were required for the Rb-dependent arrest. For example, pRb+ cells with small interfering RNA to Chk1 had approximately 60% less cells in G1 phase compared with controls and pRb- cells do not arrest upon ST. Furthermore, Chk1 expression facilitates the release of the Rb+ cells from G1 arrest. Collectively, our data suggest that pRb cooperates with Chk1 to mediate a G1 arrest only in pRb+ cells. The elucidation of this pathway can help identify novel agents to protect cancer patients against the debilitating effects of chemotherapy.

  8. p53-independent pRB degradation contributes to a drug-induced apoptosis in AGS cells

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The retinoblastoma (RB) tumor suppressor protein, pRB, plays an important role in the regulation of mammalian cell cycle. Furthermore, several lines of evidence suggest that pRB also involves in the regulation of apoptosis. In the present study, the degradation of pRB was observed in apoptotic gastric tumor cells treated with a new potent anti-tumor component, tripchlorolide (TC). The inhibition of pRB degradation by a general cysteine protease inhibitor IDAM resulted in the reduction of the apoptotic cells. Furthermore, the survival of the gastric tumor cells under the TC treatment was enhanced by an over-expression of exogenous pRB. These results suggest that the pRB degradation of the gastric tumor cells under the TC treatment involves in the apoptotic progression. In addition, the same extent of TC-induced pRB-degradation was detected in the gastric tumor cells containing a p53 dominant-negative construct, indicating that this kind of pRB degradation is p53-independent.

  9. A functional connection between pRB and transforming growth factor beta in growth inhibition and mammary gland development.

    Science.gov (United States)

    Francis, Sarah M; Bergsied, Jacqueline; Isaac, Christian E; Coschi, Courtney H; Martens, Alison L; Hojilla, Carlo V; Chakrabarti, Subrata; Dimattia, Gabriel E; Khoka, Rama; Wang, Jean Y J; Dick, Frederick A

    2009-08-01

    Transforming growth factor beta (TGF-beta) is a crucial mediator of breast development, and loss of TGF-beta-induced growth arrest is a hallmark of breast cancer. TGF-beta has been shown to inhibit cyclin-dependent kinase (CDK) activity, which leads to the accumulation of hypophosphorylated pRB. However, unlike other components of TGF-beta cytostatic signaling, pRB is thought to be dispensable for mammary development. Using gene-targeted mice carrying subtle missense changes in pRB (Rb1(DeltaL) and Rb1(NF)), we have discovered that pRB plays a critical role in mammary gland development. In particular, Rb1 mutant female mice have hyperplastic mammary epithelium and defects in nursing due to insensitivity to TGF-beta growth inhibition. In contrast with previous studies that highlighted the inhibition of cyclin/CDK activity by TGF-beta signaling, our experiments revealed that active transcriptional repression of E2F target genes by pRB downstream of CDKs is also a key component of TGF-beta cytostatic signaling. Taken together, our work demonstrates a unique functional connection between pRB and TGF-beta in growth control and mammary gland development.

  10. Cloning and Molecular Characterization of the Schistosoma mansoni Genes RbAp48 and Histone H4

    Directory of Open Access Journals (Sweden)

    Patrícia P Souza

    2002-10-01

    Full Text Available The human nuclear protein RbAp48 is a member of the tryptophan/aspartate (WD repeat family, which binds to the retinoblastoma (Rb protein. It also corresponds to the smallest subunit of the chromatin assembly factor and is able to bind to the helix 1 of histone H4, taking it to the DNA in replication. A cDNA homologous to the human gene RbAp48 was isolated from a Schistosoma mansoni adult worm library and named SmRbAp48. The full length sequence of SmRbAp48 cDNA is 1036 bp long, encoding a protein of 308 amino acids. The transcript of SmRbAp48 was detected in egg, cercariae and schistosomulum stages. The protein shows 84% similarity with the human RbAp48, possessing four WD repeats on its C-terminus. A hypothetical tridimensional structure for the SmRbAp48 C-terminal domain was constructed by computational molecular modeling using the b-subunit of the G protein as a model. To further verify a possible interaction between SmRbAp48 and S. mansoni histone H4, the histone H4 gene was amplified from adult worm genomic DNA using degenerated primers. The gene fragment of SmH4 is 294 bp long, encoding a protein of 98 amino acids which is 100% identical to histone H4 from Drosophila melanogaster.

  11. p107 in the public eye: an Rb understudy and more

    Directory of Open Access Journals (Sweden)

    Wirt Stacey E

    2010-04-01

    Full Text Available Abstract p107 and its related family members Rb and p130 are critical regulators of cellular proliferation and tumorigenesis. Due to the extent of functional overlap within the Rb family, it has been difficult to assess which functions are exclusive to individual members and which are shared. Like its family members, p107 can bind a variety of cellular proteins to affect the expression of many target genes during cell cycle progression. Unlike Rb and p130, p107 is most highly expressed during the G1 to S phase transition of the cell cycle in actively dividing cells and accumulating evidence suggests a role for p107 during DNA replication. The specific roles for p107 during differentiation and development are less clear, although emerging studies suggest that it can cooperate with other Rb family members to control differentiation in multiple cell lineages. As a tumor suppressor, p107 is not as potent as Rb, yet studies in knockout mice have revealed some tumor suppressor functions in mice, depending on the context. In this review, we identify the unique and overlapping functions of p107 during the cell cycle, differentiation, and tumorigenesis.

  12. Collimated Blue and Infrared Beams Generated by Two-Photon Excitation in Rb Vapor

    CERN Document Server

    Sell, J F; DePaola, B D; Knize, R J

    2013-01-01

    Utilizing two-photon excitation in hot Rb vapor we demonstrate the generation of collimated optical fields at 420 nm and 1324 nm. Input laser beams at 780 nm and 776 nm enter a heated Rb vapor cell collinear and circularly polarized, driving Rb atoms to the $5D_{5/2}$ state. Under phase-matching conditions coherence among the $5S_{1/2}\\rightarrow 5P_{3/2}\\rightarrow 5D_{5/2} \\rightarrow 6P_{3/2}$ transitions produces a blue (420 nm) beam by four-wave mixing. We also observe a forward and backward propagating IR (1324 nm) beam, due to cascading decays through the $6S_{1/2}\\rightarrow 5P_{1/2}$ states. Power saturation of the generated beams is investigated by scaling the input powers to greater than 200 mW, resulting in a coherent blue beam of 9.1 mW power, almost an order of magnitude larger than previously achieved. We measure the dependences of both beams in relation to the Rb density, the frequency detuning between Rb ground state hyperfine levels, and the input laser intensities.

  13. Bioconversion of ginsenoside Rb1 into compound K by Leuconostoc citreum LH1 isolated from kimchi

    Directory of Open Access Journals (Sweden)

    Lin-Hu Quan

    2011-09-01

    Full Text Available About 40 different types of ginsenoside (ginseng saponin, a major pharmacological component of ginseng, have been identified along with their physiological activities. Among these, compound K has been reported to prevent the development of and the metastasis of cancer by blocking the formation of tumors and suppressing the invasion of cancerous cells. In this study, ginsenoside Rb1 was converted into compound K via interaction with the enzyme secreted by β-glucosidase active bacteria, Leuconostoc citreum LH1, extracted from kimchi. The optimum time for the conversion of Rb1 to compound K was about 72 hrs at a constant pH of 6.0 and an optimum temperature of about 30ºC. Under optimal conditions, ginsenoside Rb1 was decomposed and converted into compound K by 72 hrs post-reaction (99%. Both TLC and HPLC were used to analyze the enzymatic reaction. Ginsenoside Rb1 was consecutively converted to ginsenoside Rd, F2, and compound K via the hydrolyses of 20-C β-(1 → 6-glucoside, 3-C β-(1 → 2glucoside, and 3-C β-glucose of ginsenoside Rb1.

  14. Solar photocatalytic degradation of RB5 by ferrite bismuth nanoparticles synthesized via ultrasound.

    Science.gov (United States)

    Soltani, T; Entezari, M H

    2013-09-01

    In this paper, the photocatalytic degradation of Reactive Black 5 (RB5) was investigated with ferrite bismuth synthesized via ultrasound under direct sunlight irradiation. The intensity of absorption peaks of RB5 gradually decreased by increasing the irradiation time and finally vanished in 50 min in acidic medium. The formation of new intermediate was observed in basic medium. The relative concentration of RB5 in solution and on the surface of ferrite bismuth (BiFeO3) nanoparticles was considered during the experiment in acidic and basic media. The effects of various parameters such as amount of catalyst, concentration of dye, and pH of the solution have been studied on the dye degradation. The adsorption isotherm and the kinetic of photocatalytic degradation of RB5 were investigated. The adsorption constants in the dark and in the presence of sunlight irradiation were compared. The photocatalytic degradation mechanism of RB5 has been evaluated through the addition of some scavengers to the solution. In addition, the stability and reusability of the catalyst were examined in this work.

  15. Lysine methylation-dependent binding of 53BP1 to the pRb tumor suppressor.

    Science.gov (United States)

    Carr, Simon M; Munro, Shonagh; Zalmas, Lykourgos-Panagiotis; Fedorov, Oleg; Johansson, Catrine; Krojer, Tobias; Sagum, Cari A; Bedford, Mark T; Oppermann, Udo; La Thangue, Nicholas B

    2014-08-01

    The retinoblastoma tumor suppressor protein pRb is a key regulator of cell cycle progression and mediator of the DNA damage response. Lysine methylation at K810, which occurs within a critical Cdk phosphorylation motif, holds pRb in the hypophosphorylated growth-suppressing state. We show here that methyl K810 is read by the tandem tudor domain containing tumor protein p53 binding protein 1 (53BP1). Structural elucidation of 53BP1 in complex with a methylated K810 pRb peptide emphasized the role of the 53BP1 tandem tudor domain in recognition of the methylated lysine and surrounding residues. Significantly, binding of 53BP1 to methyl K810 occurs on E2 promoter binding factor target genes and allows pRb activity to be effectively integrated with the DNA damage response. Our results widen the repertoire of cellular targets for 53BP1 and suggest a previously unidentified role for 53BP1 in regulating pRb tumor suppressor activity.

  16. Identification and characterization of small molecule antagonists of pRb inactivation by viral oncoproteins.

    Science.gov (United States)

    Fera, Daniela; Schultz, David C; Hodawadekar, Santosh; Reichman, Melvin; Donover, Preston Scott; Melvin, Jason; Troutman, Scott; Kissil, Joseph L; Huryn, Donna M; Marmorstein, Ronen

    2012-04-20

    The retinoblastoma protein pRb is essential for regulating many cellular activities through its binding and inhibition of E2F transcription activators, and pRb inactivation leads to many cancers. pRb activity can be perturbed by viral oncoproteins including human papillomavirus (HPV) that share an LxCxE motif. Because there are no treatments for existing HPV infection leading to nearly all cervical cancers and other cancers to a lesser extent, we screened for compounds that inhibit the ability of HPV-E7 to disrupt pRb/E2F complexes. This lead to the identification of thiadiazolidinedione compounds that bind to pRb with mid-high nanomolar dissociation constants, are competitive with the binding of viral oncoproteins containing an LxCxE motif, and are selectively cytotoxic in HPV-positive cells alone and in mice. These inhibitors provide a promising scaffold for the development of therapies to treat HPV-mediated pathologies.

  17. Improved tests of Local Position Invariance using 87Rb and 133Cs fountains

    CERN Document Server

    Guéna, Jocelyne; Rovera, Daniele; Rosenbusch, Peter; Tobar, Michael E; Laurent, Philippe; Clairon, André; Bize, Sébastien

    2012-01-01

    We report tests of Local Position Invariance (LPI) based on measurements of the ratio of the ground state hyperfine frequencies of 133Cs and 87Rb in laser-cooled atomic fountain clocks. Measurements extending over 14 years set a stringent limit to a possible variation with time of this ratio: d ln(nu_Rb/nu_Cs)/dt=(-1.39 +/- 0.91)x 10-16 yr-1. This improves by a factor of 7.7 over our previous report (H. Marion et al.}, Phys. Rev. Lett. 90, 150801 (2003)). Our measurements also set the first limit to a fractional variation of the Rb/Cs ratio with gravitational potential at the level of c^2 d ln(nu_Rb/nu_Cs)/dU=(0.11 +/- 1.04)x 10^-6, providing a new stringent differential redshift test. The above limits equivalently apply to the fractional variation of the quantity alpha^{-0.49}x(g_Rb/g_Cs), which involves the fine structure constant alpha and the ratio of the nuclear g-factors of the two alkalis. The link with variations of the light quark mass is also presented together with a global analysis combining with ...

  18. Characteristics of an Established Retinoblastoma Cell Line HXO—Rb44

    Institute of Scientific and Technical Information of China (English)

    HepingXu; HechengZhu

    1995-01-01

    Purpose:To study the retinoblastoma cell culture and to establish a new retinoblastoma cellline.Methods:22 retinoblastomes were cultured by using the method of single cellsus-pension.Characteristics of the cultured cells were studied in the following pro-grams:tumor cell morphology in vitro,electron microscopic,growth curve,cloning in soft agar,immunohistochemistry,karyotype and tumorigenicity.Results.22 retinoblastoas were cultured successfully in ivtro,only a cotinued cell line HXO-Rb44was established(more than3years).The characteristics of this cell line are that it grew as a suspension of round cell in graps like clusters in vitro,its population doubling time was 44hours,and it could be cloned in softa-gar.Histopathologic and ulatastructured pictures showed the characteristics of Rb.HXO-Rb44cell was positive to NSE and negative to GFAP in immunohis-tochemical staining.A subcutaneous injection of HXO-Rb44cells produced a retinoblastoma in BALB/C athumic nude mice.Conclusions:HXO-Rb44 has the characteristice of retinoblastoma and is a new retinoblastoma cell line.It is a useflu material for study this tumor both in basic and clinical fields.

  19. Immune response to RB1-regulated senescence limits radiation-induced osteosarcoma formation

    Science.gov (United States)

    Kansara, Maya; Leong, Huei San; Lin, Dan Mei; Popkiss, Sophie; Pang, Puiyi; Garsed, Dale W.; Walkley, Carl R.; Cullinane, Carleen; Ellul, Jason; Haynes, Nicole M.; Hicks, Rod; Kuijjer, Marieke L.; Cleton-Jansen, Anne-Marie; Hinds, Philip W.; Smyth, Mark J.; Thomas, David M.

    2013-01-01

    Ionizing radiation (IR) and germline mutations in the retinoblastoma tumor suppressor gene (RB1) are the strongest risk factors for developing osteosarcoma. Recapitulating the human predisposition, we found that Rb1+/– mice exhibited accelerated development of IR-induced osteosarcoma, with a latency of 39 weeks. Initial exposure of osteoblasts to carcinogenic doses of IR in vitro and in vivo induced RB1-dependent senescence and the expression of a panel of proteins known as senescence-associated secretory phenotype (SASP), dominated by IL-6. RB1 expression closely correlated with that of the SASP cassette in human osteosarcomas, and low expression of both RB1 and the SASP genes was associated with poor prognosis. In vivo, IL-6 was required for IR-induced senescence, which elicited NKT cell infiltration and a host inflammatory response. Mice lacking IL-6 or NKT cells had accelerated development of IR-induced osteosarcomas. These data elucidate an important link between senescence, which is a cell-autonomous tumor suppressor response, and the activation of host-dependent cancer immunosurveillance. Our findings indicate that overcoming the immune response to senescence is a rate-limiting step in the formation of IR-induced osteosarcoma. PMID:24231354

  20. Ba2+-inhibitable /sup 86/Rb+ fluxes across membranes of vesicles from toad urinary bladder

    Energy Technology Data Exchange (ETDEWEB)

    Garty, H.; Civan, M.M.

    1987-01-01

    /sup 86/Rb+ fluxes have been measured in suspensions of vesicles prepared from the epithelium of toad urinary bladder. A readily measurable barium-sensitive, ouabain-insensitive component has been identified; the concentration of external Ba2+ required for half-maximal inhibition was 0.6 mM. The effects of externally added cations on /sup 86/Rb+ influx and efflux have established that this pathway is conductive, with a selectivity for K+, Rb+ and Cs+ over Na+ and Li+. The Rb+ uptake is inversely dependent on external pH, but not significantly affected by internal Ca2+ or external amiloride, quinine, quinidine or lidocaine. It is likely, albeit not yet certain, that the conductive Rb+ pathway is incorporated in basolateral vesicles oriented right-side-out. It is also not yet clear whether this pathway comprises the principle basolateral K+ channel in vivo, and that its properties have been unchanged during the preparative procedures. Subject to these caveats, the data suggest that the inhibition by quinidine of Na+ transport across toad bladder does not arise primarily from membrane depolarization produced by a direct blockage of the basolateral channels. It now seems more likely that the quinidine-induced elevation of intracellular Ca2+ activity directly blocks apical Na+ entry.

  1. Production and spectroscopy of ultracold YbRb{sup *} molecules

    Energy Technology Data Exchange (ETDEWEB)

    Nemitz, Nils

    2008-11-15

    This thesis describes the formation of electronically excited but translationally cold molecules formed from rubidium atoms and two isotopes of ytterbium ({sup 176}Yb and {sup 174}Yb) by means of photoassociation. The experiments were performed in a combined MOT with 10{sup 9} rubidium atoms and 2.10{sup 6} ytterbium atoms at temperatures of less than 1 mK. Photoassociation lines were found by trap loss spectroscopy throughout a wavelength range of 2 nm near the 795 nm D1 transition in rubidium. The majority of lines belong to two vibrational series in the excited YbRb{sup *} molecule, converging on a system of a ground state ytterbium atom and an excited rubidium atom. The strong variation of line strength between different vibrational lines is explained through the Franck-Condon principle. An improved version of the Leroy-Bernstein equation was used to extract the leading dispersion coefficient of the potential from the vibrational progression. Most of the observed lines show a resolved rotational structure as expected from a basic quantum mechanical model. The series terminates with the third or forth rotational component due to the ground state centrifugal barrier.The measured rotational constants agree very well with calculations based on the C{sub 6} coefficient. The discovery of a splitting of the rotational components into subcomponents indicates an uncommon angular momentum coupling described by Hund's case. Variations in the depth of the subcomponents indicates a similar splitting in the ground state, with the energies of the substates based on the alignment of the rubidium atom's magnetic dipole moment relative to the angular momentum carried by an approaching ytterbium atom. This creates an additional ground state barrier, partially suppressing some of the subcomponents. Using a rate equation model developed for this purpose, a maximum formation rate of 2.5.10{sup 6} molecules per second was calculated over the volume of the entire trap. The

  2. Na,K-ATPase characterized in artificial membranes. 2. Successive measurement of ATP-driven Rb-accumulation, ouabain-blocked Rb-flux and palytoxin-induced Rb-efflux.

    Science.gov (United States)

    Anner, B M; Moosmayer, M

    1994-01-01

    The Na,K-ATPase is a multifunctional system anchored in the membrane of eukaryotic cells; it is responsible for the establishment and regulation of the Na/K balance of cell and organism by a stoichiometric mechanism linking Na extrusion to K uptake and ATP hydrolysis. The receptor for cardioactive steroids such as digoxin and ouabain is located at the extracellular surface of the system. Conversely, palytoxin, the most potent animal toxin, exerts its toxic effect by creating nonspecific leaks in the cell membrane leading to K-efflux and influx of Na and Ca ions. Ouabain prevents the pore-forming action of palytoxin in cells and therefore Na,K-ATPase is suspected to be the common receptor of ouabain and palytoxin. We have developed an artificial membrane system to determine structure-function relationships and ligand interactions of purified Na,K-ATPase: two-sided, bi-directional ATP-filled liposomes. In this system, ATP-driven 86Rb accumulation, arrest of 86Rb-uptake by ouabain, and palytoxin-induced 86Rb-leak were measured successively in the same preparation. Ouabain prevented the leak when the enzyme was ouabain-sensitive (rabbit kidney) but not when it was ouabain-resistant (rat kidney). On the basis of these data in conjunction with conformational analyses, allosteric conformational competition for the ouabain-palytoxin antagonism is proposed.

  3. Generation of induced pluripotent stem cells (iPSCs from a retinoblastoma patient carrying a c.2663G>A mutation in RB1 gene

    Directory of Open Access Journals (Sweden)

    Sicong Zeng

    2016-09-01

    Full Text Available Skin fibroblasts were obtained from a male patient diagnosed with retinoblastoma (RB carrying a c.2663G>A mutation in the 25 exon of RB1 gene. RB-iPS cells was generated via delivered four reprogramming factors (OCT4, SOX2, NANOG and LIN28 into these skin fibroblasts. The RB-iPS cells retained the RB1 heterozygous mutation resulted in a truncated RB1 mRNA. Characteristic tests proved that the iPSC line presented typical markers of pluripotency and had the capability to form the three germ layers in vitro.

  4. K-Ca and Rb-Sr Dating of Lunar Granite 14321 Revisited

    Science.gov (United States)

    Simon, Justin I.; Shih, C.-Y.; Nyquist, L. E.

    2011-01-01

    K-Ca and Rb-Sr age determinations were made for a bulk feldspar-rich portion of an Apollo rock fragment of the pristine lunar granite clast (14321,1062), an acid-leached split of the sample, and the leachate. K-Ca and Rb-Sr data were also obtained for a whole rock sample of Apollo ferroan anorthosite (FAN, 15415). The recent detection [1] of widespread intermediate composition plagioclase indicates that the generation of a diversity of evolved lunar magmas maybe more common and therefore more important to our understanding of crust formation than previously believed. Our new data strengthen the K-Ca and Rb-Sr internal isochrons of the well-studied Apollo sample 14321 [2], which along with a renewed effort to study evolved lunar magmas will provide an improved understanding of the petrogenetic history of evolved rocks on the Moon.

  5. Optimal r/b ratio of bend channel in centrifugal compressor

    Institute of Scientific and Technical Information of China (English)

    Suping WEN; Xiaowen HU; Yong ZHANG; Jun WANG; Tingbin LI

    2008-01-01

    A numerical investigation on the flow in a bend channel by coupling the impeller with the vaneless diffuser in a centrifugal compressor with different r/b ratios (bend radius r to bend channel width b) is presented. The jet-wake effect of the impeller outlet is considered and flow pattern in the bend channel and the performance of the centrifugal compressor stage are investigated. The results indicate that there is an optimal r/b ratio for increasing the stage efficiency to the highest for a specific compressor stage. The change in r/b ratio significantly affects the flow angle of the bend chan-nel outlet. The prime reason for the total pressure loss in the bend channel is the wall friction in the bend channel.

  6. Long Non-Coding RNAs Embedded in the Rb and p53 Pathways

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, Murugan; Jones, Matthew F.; Lal, Ashish, E-mail: ashish.lal@nih.gov [Genetics Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States)

    2013-12-04

    In recent years, long non-coding RNAs (lncRNAs) have gained significant attention as a novel class of gene regulators. Although a small number of lncRNAs have been shown to regulate gene expression through diverse mechanisms including transcriptional regulation, mRNA splicing and translation, the physiological function and mechanism of action of the vast majority are not known. Profiling studies in cell lines and tumor samples have suggested a potential role of lncRNAs in cancer. Indeed, distinct lncRNAs have been shown to be embedded in the p53 and Rb networks, two of the major tumor suppressor pathways that control cell cycle progression and survival. Given the fact that inactivation of Rb and p53 is a hallmark of human cancer, in this review we discuss recent evidence on the function of lncRNAs in the Rb and p53 signaling pathways.

  7. Bose-Einstein condensation of 87Rb in a levitated crossed dipole trap

    CERN Document Server

    Jenkin, D L; Köppinger, M P; Cho, H -W; Hopkins, S A; Cornish, S L

    2011-01-01

    We report an apparatus and method capable of producing Bose-Einstein condensates (BECs) of ~1x10^6 87Rb atoms, and ultimately designed for sympathetic cooling of 133Cs and the creation of ultracold RbCs molecules. The method combines several elements: i) the large recapture of a magnetic quadrupole trap from a magneto-optical trap, ii) efficient forced RF evaporation in such a magnetic trap, iii) the gain in phase-space density obtained when loading the magnetically trapped atoms into a far red-detuned optical dipole trap and iv) efficient evaporation to BEC within the dipole trap. We demonstrate that the system is capable of sympathetically cooling the |F=1,m_F=-1> and |1,0> sublevels with |1,+1> atoms. Finally we discuss the applicability of the method to sympathetic cooling of 133Cs with 87Rb.

  8. Observation of Quantum Beating from Two Coupled Parametric Six-Wave Mixing Signals in Rb

    Institute of Scientific and Technical Information of China (English)

    ZHU Chang-Jun; HE Jun-Fang; ZHAI Xue-Jun; XUE Bing

    2008-01-01

    Two processes of coupled difference-frequency axially phase-matched parametric six-wave mixing are carried out in Rb vapour by two-photon excitation using fs laser pulses, and parametric six-wave mixing signals in the infrared and near infrared regime are detected. The infrared parametric six-wave mixing signals are up-converted into the visible spectral range by sum-frequency mixing with the pump laser in a LiI03 crystal. Moreover, quantum beating at 608cm-1, corresponding to the 7s - 5d energy difference in Rb, is observed from the sum-frequency signal at 495 nm. As a result, we obtain modulated light signals in the visible, near infrared and infrared spectral ranges, and study the interference between 7s and 5d states of Rb.

  9. Hyperfine frequencies of 87Rb and 133Cs atoms in Xe gas

    CERN Document Server

    McGuyer, B H; Happer, W; 10.1103/PhysRevA.84.030501

    2013-01-01

    The microwave resonant frequencies of ground-state 87Rb and 133Cs atoms in Xe buffer gas are shown to have a relatively large nonlinear dependence on the Xe pressure, presumably because of RbXe or CsXe van der Waals molecules. The nonlinear shifts for Xe are opposite in sign to the previously measured shifts for Ar and Kr, even though all three gases have negative linear shifts. The Xe data show striking discrepancies with the previous theory for nonlinear shifts. Most of this discrepancy is eliminated by accounting for the spin-rotation interaction in addition to the hyperfine-shift interaction in the molecules. To the limit of our experimental accuracy, the shifts of 87Rb and 133Cs in He, Ne, and N2 were linear with pressure.

  10. Essential features of optical processes in neon-buffered submicron-thin Rb vapor cell.

    Science.gov (United States)

    Hakhumyan, Grant; Sargsyan, Armen; Leroy, Claude; Pashayan-Leroy, Yevgenya; Papoyan, Aram; Sarkisyan, David

    2010-07-05

    A new submicron thin cell (STC) filled with Rb and neon gas is developed and comparison of resonant absorption with STC containing pure Rb is provided. The effect of collapse and revival of Dicke-type narrowing is still observable for the thickness L = lambda /2 and L = lambda , where lambda is a resonant laser wavelength 794 nm (D(1) line). For an ordinary Rb cm-size cell with addition of buffer gas, the velocity selective optical pumping/saturation (VSOP) resonances in saturated absorption spectra are fully suppressed if neon pressure > 0.5 Torr. A spectacular difference is that for L = lambda , VSOP resonances are still observable even when neon pressure is > or = 6 Torr. Narrow fluorescence spectra at L = lambda /2 allow one to realize online buffer gas pressure monitoring. A good agreement with theoretical model is observed.

  11. Luminescence and scintillation properties of Rb2HfCl6 crystals

    Science.gov (United States)

    Saeki, Keiichiro; Wakai, Yuki; Fujimoto, Yutaka; Koshimizu, Masanori; Yanagida, Takayuki; Nakauchi, Daisuke; Asai, Keisuke

    2016-11-01

    We developed a scintillator based on a Rb2HfCl6 crystal as a ternary halide crystal with intrinsic luminescence. In the photoluminescence spectra, two emission bands are observed at 383 and 434 nm. The 434 nm emission band for Rb2HfCl6 may be attributed to [HfCl6]2- complex ion or [ZrCl6]2- impurity, since the Rb2HfCl6 contained Zr as impurity at 0.62 mol %. The radioluminescence band is observed at 420 nm and can be attributed to the same origin as the photoluminescence band at 434 nm. The scintillation decay-time constants were 0.84 and 5.4 µs. The light yield was estimated to be 24,100 photons/MeV.

  12. Bloch oscillations of ultracold atoms: a tool for a metrological determination of h/m Rb.

    Science.gov (United States)

    Battesti, Rémy; Cladé, Pierre; Guellati-Khélifa, Saïda; Schwob, Catherine; Grémaud, Benoît; Nez, François; Julien, Lucile; Biraben, François

    2004-06-25

    We use Bloch oscillations in a horizontal moving standing wave to transfer a large number of photon recoils to atoms with a high efficiency (99.5% per cycle). By measuring the photon recoil of 87Rb, using velocity-selective Raman transitions to select a subrecoil velocity class and to measure the final accelerated velocity class, we have determined h/m(Rb) with a relative precision of 0.4 ppm. To exploit the high momentum transfer efficiency of our method, we are developing a vertical standing wave setup. This will allow us to measure h/m(Rb) better than 10(-8) and hence the fine structure constant alpha with an uncertainty close to the most accurate value coming from the (g-2) determination.

  13. Formation of ultracold metastable RbCs molecules by short-range photoassociation

    CERN Document Server

    Gabbanini, C

    2011-01-01

    Ultracold metastable RbCs molecules are observed in a double species MOT through photoassociation near the Rb(5S$_{1/2}$)+Cs(6P$_{3/2}$) dissociation limit followed by radiative stabilization. The molecules are formed in their lowest triplet electronic state and are detected by resonant enhanced two-photon ionization through the previously unobserved $(3)^{3}\\Pi \\leftarrow a^{3}\\Sigma^{+}$ band. The large rotational structure of the observed photoassociation lines is assigned to the lowest vibrational levels of the $0^+,0^-$ excited states correlated to the Rb(5P$_{1/2}$)+Cs(6S$_{1/2}$) dissociation limit. This demonstrates the possibility to induce direct photoassociation in heteronuclear alkali-metal molecules at short internuclear distance, as pointed out in [J. Deiglmayr \\textit{et al.}, Phys. Rev. Lett. \\textbf{101}, 13304 (2008)].

  14. Diffusion of Rb atoms in paraffin-coated resonant vapor cells

    Science.gov (United States)

    Atutov, Sergey N.; Benimetskiy, Fedor A.; Plekhanov, Alexander I.; Sorokin, Vladimir A.; Yakovlev, Alexander V.

    2017-01-01

    We present the results of a study of the diffusion of Rb atoms in paraffin-coated resonant vapor cells. We have modeled the Rb diffusion both in the cell and in the coating, assuming that the main loss of Rb atoms is due to the physical absorption of the atoms by the glass substrate. It is demonstrated that the equilibrium of atomic density in the cell is a monotonic function of the thickness of the paraffin coating: the density increases with an increase in the thickness of the coating. The diffusion coefficient for rubidium in paraffin thin films has been determined to be equal to 5 × 10-7 cm2/s. The results of the experiment might provide for a better understanding of the processes involved in the interaction of alkali atoms with a paraffin coating and atomic diffusion in resonant vapor cells.

  15. SUSY effects in $R_b$: revisited under current experimental constraints

    CERN Document Server

    Su, Wei

    2016-01-01

    In this note we revisit the effects of natural SUSY in $R_b$ under current experimental constraints including the LHC Higgs data, the $B$-physics measurements, the dark matter relic density and direct detection limits, as well as the precision electroweak data. We first perform a scan to figure out the currently allowed parameter space of natural SUSY and then display the SUSY effects in $R_b$. We find that although the SUSY parameter space has been severely restrained by current experimental data, natural SUSY can still alter $R_b$ with a magnitude sizable enough to be observed at future $Z$-factories (ILC, CEPC, FCC-ee, Super $Z$-factory) which produce $10^9-10^{12}$ $Z$-bosons.

  16. A diagnostic protocol to identify water buffaloes (Bubalus bubalis) vaccinated with Brucella abortus strain RB51 vaccine.

    Science.gov (United States)

    Tittarelli, Manuela; Atzeni, Marcello; Calistri, Paolo; Di Giannatale, Elisabetta; Ferri, Nicola; Marchi, Enrico; Martucciello, Alessandra; De Massis, Fabrizio

    2015-01-01

    The use of live vaccine strain RB51 for vaccination of domestic water buffaloes (Bubalus bubalis) at risk of infection with Brucella abortus is permitted notwithstanding the plans for the eradication and only under strict veterinary control. The antibodies induced by RB51 vaccination are not detectable using conventional diagnostic techniques; therefore, it is necessary to have a specific diagnostic tool able to discriminate vaccinated from unvaccinated animals. The combination of a complement fixation test (CFT) with specific RB51 antigen (RB51-CFT) and a brucellin skin test has been demonstrated to be a reliable diagnostic system to identify single cattle (Bos taurus) vaccinated with RB51. So far, no data are available in the international scientific literature regarding the use of this test association in water buffalo. For this reason the suitability of this test combination has been evaluated in a water buffalo herd. One hundred twenty-seven animals farmed in a herd of Salerno province (Campania, Southern Italy), in the context of a presumptive unauthorized use of RB51 vaccine were chosen for this study. All tested animals resulted negative to Rose Bengal test (RBT) and complement fixation test (CFT) used for the detection of specific antibodies against Brucella field strains. Seventy-one animals (56%) developed RB51 antigen-specific CFT (RB51-CFT) antibodies against RB51 vaccine in a first sampling, while 104 animals (82%) gave positive result to a second serum sampling conducted 11 days after the intradermal inoculation of the RB51 brucellin. One hundred and seven animals (84%) showed a positive reaction to the RB51-CFT in at least 1 sampling, while 111 animals (87%) resulted positive to the RB51 brucellin skin test. Thus, analysing the results of the 3 testing in parallel, 119 animals (94%) were positive to at least 1 of the performed tests. The results suggest that the use in parallel of the RB51 brucellin skin test with RB51-CFT may represent a reliable

  17. RNAi mediated acute depletion of Retinoblastoma protein (pRb promotes aneuploidy in human primary cells via micronuclei formation

    Directory of Open Access Journals (Sweden)

    Iovino Flora

    2009-11-01

    Full Text Available Abstract Background Changes in chromosome number or structure as well as supernumerary centrosomes and multipolar mitoses are commonly observed in human tumors. Thus, centrosome amplification and mitotic checkpoint dysfunctions are believed possible causes of chromosomal instability. The Retinoblastoma tumor suppressor (RB participates in the regulation of synchrony between DNA synthesis and centrosome duplication and it is involved in transcription regulation of some mitotic genes. Primary human fibroblasts were transfected transiently with short interfering RNA (siRNA specific for human pRb to investigate the effects of pRb acute loss on chromosomal stability. Results Acutely pRb-depleted fibroblasts showed altered expression of genes necessary for cell cycle progression, centrosome homeostasis, kinetochore and mitotic checkpoint proteins. Despite altered expression of genes involved in the Spindle Assembly Checkpoint (SAC the checkpoint seemed to function properly in pRb-depleted fibroblasts. In particular AURORA-A and PLK1 overexpression suggested that these two genes might have a role in the observed genomic instability. However, when they were post-transcriptionally silenced in pRb-depleted fibroblasts we did not observe reduction in the number of aneuploid cells. This finding suggests that overexpression of these two genes did not contribute to genomic instability triggered by RB acute loss although it affected cell proliferation. Acutely pRb-depleted human fibroblasts showed the presence of micronuclei containing whole chromosomes besides the presence of supernumerary centrosomes and aneuploidy. Conclusion Here we show for the first time that RB acute loss triggers centrosome amplification and aneuploidy in human primary fibroblasts. Altogether, our results suggest that pRb-depleted primary human fibroblasts possess an intact spindle checkpoint and that micronuclei, likely caused by mis-attached kinetochores that in turn trigger

  18. Physical and Functional Interactions between ELL2 and RB in the Suppression of Prostate Cancer Cell Proliferation, Migration, and Invasion

    Directory of Open Access Journals (Sweden)

    Xiaonan Qiu

    2017-03-01

    Full Text Available Elongation factor, RNA polymerase II, 2 (ELL2 is expressed and regulated by androgens in the prostate. ELL2 and ELL-associated factor 2 (EAF2 form a stable complex, and their orthologs in Caenorhabditis elegans appear to be functionally similar. In C. elegans, the EAF2 ortholog eaf-1 was reported to interact with the retinoblastoma (RB pathway to control development and fertility in worms. Because RB loss is frequent in prostate cancer, ELL2 interaction with RB might be important for prostate homeostasis. The present study explored physical and functional interaction of ELL2 with RB in prostate cancer. ELL2 expression in human prostate cancer specimens was detected using quantitative polymerase chain reaction coupled with laser capture microdissection. Co-immunoprecipitation coupled with deletion mutagenesis was used to determine ELL2 association with RB. Functional interaction between ELL2 and RB was tested using siRNA knockdown, BrdU incorporation, Transwell, and/or invasion assays in LNCaP, C4-2, and 22Rv1 prostate cancer cells. ELL2 expression was downregulated in high–Gleason score prostate cancer specimens. ELL2 could be bound and stabilized by RB, and this interaction was mediated through the N-terminus of ELL2 and the C-terminus of RB. Concurrent siRNA knockdown of ELL2 and RB enhanced cell proliferation, migration, and invasion as compared to knockdown of ELL2 or RB alone in prostate cancer cells. ELL2 and RB can interact physically and functionally to suppress prostate cancer progression.

  19. Dual Loss of Rb1 and Trp53 in the Adrenal Medulla Leads to Spontaneous Pheochromocytoma

    Directory of Open Access Journals (Sweden)

    Ian D. Tonks

    2010-03-01

    Full Text Available Using a Cre/loxP system, we have determined the phenotypic consequences attributable to in vivo deletion of both Rb1 and Trp53 in the mouse adrenal medulla. The coablation of these two tumor suppressor genes during embryogenesis did not disrupt adrenal gland development but resulted in the neoplastic transformation of the neural crest-derived adrenal medulla, yielding pheochromocytomas (PCCs that developed with complete penetrance and were inevitably bilateral. Despite their typically benign status, these PCCs had profound ramifications on mouse vitality, with effected mice having a median survival of only 121 days. Evaluation of these PCCs by both immunohistochemistry and electron microscopy revealed that most Rb1-/-:Trp53-/- chromaffin cells possessed atypical chromagenic vesicles that did not seem capable of appropriately storing synthesized catecholamines. The structural remodeling of the heart in mice harboring Rb1-/-:Trp53-/- PCCs suggests that the mortality of these mice may be attributable to the inappropriate release of catecholamines from the mutated adrenal chromaffin cells. On the basis of the collective data from Rb1 and Trp53 knockout mouse models, it seems that the conversion of Rb1 loss-driven adrenal medulla hyperplasia to PCC can be greatly enhanced by the compound loss of Trp53, whereas the loss of Trp53 alone is generally ineffectual on adrenal chromaffin cell homeostasis. Consequently, the Trp53 tumor suppressor gene is an efficient genetic modifier of Rb1 loss in the development of PCC, and their compound loss in the adrenal medulla has a profound impact on both cellular homeostasis and animal vitality.

  20. Synthesis and Single Crystal Structure of RbEr2Cu3Se5

    Institute of Scientific and Technical Information of China (English)

    曾卉一; 董振超; 等

    2002-01-01

    Single crystals of a new quaternary rare-earth selenide RbEr2Cu3Se5 have been isolated through the RbCl flux reaction in the RE-Cu-Se system. The title compound crystallizes in an orthorhombic system, space group Cmcm with a = 4.089(2), b = 14.498(6), c = 16.977(2)A, V = 1006.5(7)A3, Z = 4, Dc = 6.63 g/cm3, F(000) = 1720 and (MoKa) = 45.51 mm-1. The final R = 0.0498 and wR = 0.0734 for 1401 observed reflections with I > 3σ(I. The structure of RbEr2Cu3Se5 is a three-dimensional tunnel structure composed of ErSe6 and CuSe4 polyhedra with the charge-balanced Rb+ cations stuffing into the one-dimensional channels along the a direction. In the Er2RbCu3Se5 structure, the [Er2Se(1)4/2Se(2)2Se(3)4/2] double-octahedral chains are linked into a [Er2Cu2Se6] layer in the a-b plane via sharing Se1-Se3 edges with the [Cu(2)2Se(1)2Se(3)4/2] double tetrahedral chains, and [Er2Cu2Se6] layers are further interconnected along the c direction by sharing Se(1)-Se(2) edges with the [Cu(1)Se(1)2Se(2)2/2] tetrahedral chains, forming a three-dimensional framework with the channels along the a axis accommodated by Rb+ ions.

  1. 人参提取物Rb1对瘢痕增生的作用

    Institute of Scientific and Technical Information of China (English)

    张克勤; 岳毅刚; 李昕珊

    2015-01-01

    目的:观察人参提取物Rb1成分对增生性瘢痕的作用。方法:选取十分成熟的兔耳增生性瘢痕模型,每只耳朵做3处增生性瘢痕,每个瘢痕做不同处理:空白对照组(a),生理盐水注射组(b),人参提取物组(c )。测定Masson染色,胶原含量,免疫组织化学上相关胶原Ⅰ型蛋白表达。结果:人参Rb1组瘢痕增生程度轻、胶原含量下降、Ⅰ型胶原蛋白表达低。结论:Rb1可以抑制增生性瘢痕的发展。%Objective To study the effect of ginseng extract Rb1 component on hypertrophic scars, providing a new method for the treatment of hypertrophic scars. Methods Select a very mature hypertrophic scar model rabbit ears, do three in each ear hypertrophic scars, scars do each different treatment:control group (a), saline injection group (b), ginseng extract (c). To subject the Masson staining, collagen determination and chemical related expression of immunohistochemistry protein col agen type 1 in each group. Results The Masson staining, collagen determination and chemical related expression of immunohistochemistry protein collagen type 1 in Rb1 group were lower than the other groups. Conclusion The Rb1 can inhibit the development of hypertrophic scars.

  2. Ginseng panaxoside Rb1 reduces body weight in diet-induced obese mice.

    Science.gov (United States)

    Lin, Ning; Cai, Dong-Lian; Jin, Di; Chen, Yi; Shi, Jiao-Jiao

    2014-01-01

    Crude extracts from ginseng demonstrated anti-obesity properties. Ginsenoside Rb1 is the main component of ginseng, however, there are only few studies examining its effects in obesity. In the present study, we evaluated its potential anti-obesity effects in the murine model of diet-induced obesity. Seventy male C57BL/6 mice were randomly divided to consume for 12 weeks either chow diet (N = 8) or high-fat (HF) diet (N = 62). The latter mice were then divided into four groups: diet-induced obesity group (DIO; N = 10), obesity-resistant group (OR; N = 10), HF group (N = 5), and the group whose diet was changed from HF to normal diet (DC; N = 5). Intraperitoneal injections of Rb-1 were administered daily to mice in the DIO and OR groups for 3 weeks. Body weight and energy intake were monitored, and fasting blood glucose, lipids, neuropeptide Y, Y2 receptor, and peptide YY were quantified. Compared with HF group, weight gain and food intake of DIO mice with Rb-1 injection was significantly decreased (p < 0.05). Further, levels of blood glucose and some lipids were also decreased in DIO-Rb1 group compared with HF group. Furthermore, Rb1 was also found to modulate serum levels of PYY and NPY, and mRNA expression of NPY, Y2 receptor and PYY in tissue samples of DIO mice. Taken together, ginsenoside Rb1 may be useful in the treatment of obesity via modifying the serum content and mRNA expression of NPY, Y2 receptor and PYY.

  3. High-resolution Measurement of Contact Ion-pair Structures in Aqueous RbCl Solutions from the Simultaneous Corefinement of their Rb and Cl K-edge XAFS and XRD Spectra

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Van-Thai; Fulton, John L.

    2016-06-21

    In concentrated solutions of aqueous RbCl, all of the Rb+ and Cl- ions exist as contact ion pairs. This full structural assessment is derived from the refinement of three independent experimental measurements: the Rb and Cl K-edge x-ray absorption fine structure (XAFS) and the x-ray diffraction spectra (XRD). This simultaneous refinement of the XAFS and XRD data provides high accuracy since each method probes the structure of different local regions about the ions with high sensitivity. At high RbCl concentration (6 m (mol/kg )) the solution is dominated by Rb+ - Cl- contact ion pairs yielding an average of 1.5 pairs at an Rb-Cl distance of 3.24 Å. Upon formation of these ion pairs, approximately 1.1 waters molecules are displaced from the Rb+ and 1.4 water molecules from Cl-. The hydration shells about both the cation and anion are also determined. These results greatly improve the understanding of monovalent ions and provide a basis for testing the Rb+-Cl- interaction potentials used in molecular dynamics (MD) simulation. This research was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences.

  4. Phase-modulated electronic wave-packet interferometry reveals high resolution vibronic spectra of free Rb atoms and Rb*He molecules

    CERN Document Server

    Bruder, Lukas; Stienkemeier, Frank

    2015-01-01

    Phase-modulated wave-packet interferometry is combined with mass-resolved photoion detection to investigate rubidium atoms attached to helium nanodroplets in a molecular beam experiment. The spectra of atomic Rb electronic states show a vastly enhanced sensitivity and spectral resolution when compared to conventional pump-probe wave-packet interferometry. Furthermore, the formation of Rb*He exciplex molecules is probed and for the first time a fully resolved vibrational spectrum for transitions between the lowest excited $5\\Pi_{3/2}$ and the high-lying electronic states $2^2\\Pi$, $4^2\\Delta$, $6^2\\Sigma$ is obtained and compared to theory. The feasibility of applying coherent multidimensional spectroscopy to dilute cold gas phase samples is demonstrated in these experiments.

  5. Complex impedance analysis of RbNO{sub 3} and RbNO{sub 3}:Al{sub 2}O{sub 3} dispersed solid electrolyte systems

    Energy Technology Data Exchange (ETDEWEB)

    Rao, M.V. Madhava [Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan (China); Reddy, S. Narender [Department of Physics, P.G. College of Science (O.U.), Saifabad 500 004 (India); Chary, A. Sadananda [Department of Physics, P.G. College of Science (O.U.), Saifabad 500 004 (India)]. E-mail: aschary60@yahoo.co.in; Shahi, K. [Department of Physics, Indian Institute of Technology, Kanpur 208 016 (India)

    2005-07-15

    Complex impedance spectroscopic studies were carried out on RbNO{sub 3} and RbNO{sub 3}-Al{sub 2}O{sub 3} dispersed solid electrolyte systems (DSES) in the temperature range of 50 deg C to 300 deg C and the frequency 50 KHz to 1 MHz. Dielectric constant, loss tangent, and AC conductivity, in these systems are presented. Dielectric constant, loss and AC conductivity are found to increase with temperature and with mole percent of Al{sub 2}O{sub 3}. These dielectric properties are interpreted in terms of space charge polarization and increased concentration of defects in the interfacial layer formed between the host and the dispersoid.

  6. RbZnFe(PO4)2: synthesis and crystal structure

    Science.gov (United States)

    Badri, Abdessalem; Ben Amara, Mongi

    2016-01-01

    A new iron phosphate, rubidium zinc iron(III) phosphate, RbZnFe(PO4)2, has been synthesized as single crystals by the flux method. This compound is isostructural to the previously reported KCoAl(PO4)2 [Chen et al. (1997 ▸). Acta Cryst. C53,1754–1756]. Its structure consists of a three-dimensional framework built up from corner-sharing PO4 and (Zn,Fe)O4 tetra­hedra. This mode of linkage forms channels parallel to the [100], [010] and [001] directions in which the Rb+ ions are located. PMID:27536385

  7. Total absorption spectroscopy study of $^{92}$Rb decay: a major contributor to reactor antineutrino flux

    CERN Document Server

    Zakari-Issoufou, A -A; Porta, A; Algora, A; Tain, J L; Valencia, E; Rice, S; Bui, V M; Cormon, S; Estienne, M; Agramunt, J; Äystö, J; Bowry, M; Briz, J A; Caballero-Folch, R; Cano-Ott, D; Cucoanes, A; Elomaa, V -V; Eronen, T; Estévez, E; Farrelly, G F; Garcia, A R; Gelletly, W; Gomez-Hornillos, M B; Gorlychev, V; Hakala, J; Jokinen, A; Jordan, M D; Kankainen, A; Karvonen, P; Kolhinen, V S; Kondev, F G; Martinez, T; Mendoza, E; Molina, F; Moore, I; Perez, A; Podolyák, Zs; Penttilä, H; Regan, P H; Reponen, M; Rissanen, J; Rubio, B; Shiba, T; Sonzogni, A A; Weber, C

    2015-01-01

    The antineutrino spectra measured in recent experiments at reactors are inconsistent with calculations based on the conversion of integral beta spectra recorded at the ILL reactor. $^{92}$Rb makes the dominant contribution to the reactor spectrum in the 5-8 MeV range but its decay properties are in question. We have studied $^{92}$Rb decay with total absorption spectroscopy. Previously unobserved beta feeding was seen in the 4.5-5.5 region and the GS to GS feeding was found to be 87.5(25)%. The impact on the reactor antineutrino spectra calculated with the summation method is shown and discussed.

  8. The environmental impact of recombinant bovine somatotropin (rbST) use in dairy production

    OpenAIRE

    Capper, Judith L.; Castañeda-Gutiérrez, Euridice; Cady, Roger A.; Bauman, Dale E.

    2008-01-01

    The environmental impact of using recombinant bovine somatotropin (rbST) in dairy production was examined on an individual cow, industry-scale adoption, and overall production system basis. An average 2006 U.S. milk yield of 28.9 kg per day was used, with a daily response to rbST supplementation of 4.5 kg per cow. Rations were formulated and both resource inputs (feedstuffs, fertilizers, and fuels) and waste outputs (nutrient excretion and greenhouse gas emissions) calculated. The wider envir...

  9. Preparation and Photoemission Spectra of Rb3C60 Single-Crystal Thin Films

    Institute of Scientific and Technical Information of China (English)

    李宏年; 吴太权; 陈晓; 李海洋; 鲍世宁; 徐亚伯; 钱海杰; 易卜拉欣奎热西; 刘风琴

    2002-01-01

    Rb3 C60 single-crystal thin films were prepared on the cleaved (111) surface of C60 single crystal. The photoemission spectrum line shapes of the lowest unoccupied molecular orbital (LUMO) derived band at room temperature and 150K were established by synchrotron radiation photoemission spectrum measurements. The density of states near the Fermi level was distinctly affected by temperature. No less than six sub-peaks of the LUMOband were observed even at room temperature. The existence of so many sub-peaks offered the opportunities to analyse in more detail the orientational structure and the electron-Boson interactions of the narrow-band metallic Rb3 C60 .

  10. A Measurement of $R_b$ using a Lifetime-Mass Tag

    CERN Document Server

    Barate, R; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Nief, J Y; Pietrzyk, B; Casado, M P; Chmeissani, M; Comas, P; Crespo, J M; Delfino, M C; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Miquel, R; Mir, L M; Orteu, S; Padilla, C; Park, I C; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Gelao, G; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Nuzzo, S; Ranieri, A; Raso, G; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Tricomi, A; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Abbaneo, D; Alemany, R; Becker, U; Bazarko, A O; Bright-Thomas, P G; Cattaneo, M; Cerutti, F; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Lutters, G; Mato, P; Minten, Adolf G; Moneta, L; Pacheco, A; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rizzo, G; Rolandi, Luigi; Schlatter, W D; Schmitt, M; Schneider, O; Tejessy, W; Tomalin, I R; Wachsmuth, H W; Wagner, A; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Ferdi, C; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rosnet, P; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Rensch, B; Wäänänen, A; Daskalakis, G; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Zachariadou, K; Corden, M; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Casper, David William; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Scarr, J M; Smith, K; Teixeira-Dias, P; Thompson, A S; Thomson, E; Thomson, F; Turnbull, R M; Geweniger, C; Graefe, G; Hanke, P; Hansper, G; Hepp, V; Kluge, E E; Putzer, A; Schmidt, M; Sommer, J; Tittel, K; Werner, S; Wunsch, M; Beuselinck, R; Binnie, David M; Cameron, W; Dornan, Peter J; Girone, M; Goodsir, S M; Martin, E B; Moutoussi, A; Nash, J; Sedgbeer, J K; Stacey, A M; Williams, M D; Dissertori, G; Ghete, V M; Girtler, P; Kuhn, D; Rudolph, G; Betteridge, A P; Bowdery, C K; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Williams, M I; Galla, A; Giehl, I; Greene, A M; Hoffmann, C; Jakobs, K; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Coyle, P; Diaconu, C A; Etienne, F; Konstantinidis, N P; Leroy, O; Motsch, F; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Aleppo, M; Ragusa, F; Berlich, R; Blum, Walter; Brown, D; Büscher, V; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Stenzel, H; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Chen, S; Choi, Y; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Höcker, A; Jacholkowska, A; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Schune, M H; Simion, S; Tournefier, E; Veillet, J J; Videau, I; Zerwas, D; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Palla, Fabrizio; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Venturi, A; Verdini, P G; Blair, G A; Bryant, L M; Chambers, J T; Gao, Y; Green, M G; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Maley, P; Norton, P R; Thompson, J C; Wright, A E; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Black, S N; Dann, J H; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Kelly, M S; Lehto, M H; Newton, W M; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Grupen, Claus; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Charles, E; Elmer, P; Ferguson, D P S; Gao, Y S; González, S; Greening, T C; Hayes, O J; Hu, H; Jin, S; McNamara, P A; Nachtman, J M; Nielsen, J; Orejudos, W; Pan, Y B; Saadi, Y; Scott, I J; Walsh, J; Wu Sau Lan; Wu, X; Yamartino, J M; Zobernig, G

    1997-01-01

    ALEPH's published measurement of $R_b$ using a lifetime tag, is updated using the full LEP~1 data sample. Considerable effort has been devoted to understanding systematic effects. Charm background is better controlled by combining the lifetime tag with a tag based on the b/c hadron mass difference. Furthermore, the algorithm used to reconstruct the event primary vertex is designed so as to reduce correlations between the two hemispheres of an event. The value of $R_b$ is measured to be $0.2167\\pm 0.0011{\\mathrm (stat)}\\pm 0.0013{\\mathrm (syst)}$.

  11. Thin-film superconducting resonator tunable to the ground-state hyperfine splitting of $^{87}$Rb

    CERN Document Server

    Kim, Z; Hoffman, J E; Grover, J A; Voigt, K D; Cooper, B K; Ballard, C J; Palmer, B S; Hafezi, M; Taylor, J M; Anderson, J R; Dragt, A J; Lobb, C J; Orozco, L A; Rolston, S L; Wellstood, F C

    2011-01-01

    We describe a thin-film superconducting Nb microwave resonator, tunable to within 0.3 ppm of the hyperfine splitting of $^{87}$Rb at $f_{Rb}=6.834683$ GHz. We coarsely tuned the resonator using electron-beam lithography, decreasing the resonance frequency from 6.8637 GHz to 6.8278 GHz. For \\emph{in situ} fine tuning at 15 mK, the resonator inductance was varied using a piezoelectric stage to move a superconducting pin above the resonator. We found a maximum frequency shift of about 8.7 kHz per 60-nm piezoelectric step and a tuning range of 18 MHz.

  12. Total Absorption Spectroscopy Study of 92Rb Decay: A Major Contributor to Reactor Antineutrino Spectrum Shape

    Science.gov (United States)

    Zakari-Issoufou, A.-A.; Fallot, M.; Porta, A.; Algora, A.; Tain, J. L.; Valencia, E.; Rice, S.; Bui, V. M.; Cormon, S.; Estienne, M.; Agramunt, J.; ńystö, J.; Bowry, M.; Briz, J. A.; Caballero-Folch, R.; Cano-Ott, D.; Cucoanes, A.; Elomaa, V.-V.; Eronen, T.; Estévez, E.; Farrelly, G. F.; Garcia, A. R.; Gelletly, W.; Gomez-Hornillos, M. B.; Gorlychev, V.; Hakala, J.; Jokinen, A.; Jordan, M. D.; Kankainen, A.; Karvonen, P.; Kolhinen, V. S.; Kondev, F. G.; Martinez, T.; Mendoza, E.; Molina, F.; Moore, I.; Perez-Cerdán, A. B.; Podolyák, Zs.; Penttilä, H.; Regan, P. H.; Reponen, M.; Rissanen, J.; Rubio, B.; Shiba, T.; Sonzogni, A. A.; Weber, C.

    2015-09-01

    The antineutrino spectra measured in recent experiments at reactors are inconsistent with calculations based on the conversion of integral beta spectra recorded at the ILL reactor. 92Rb makes the dominant contribution to the reactor antineutrino spectrum in the 5-8 MeV range but its decay properties are in question. We have studied 92Rb decay with total absorption spectroscopy. Previously unobserved beta feeding was seen in the 4.5-5.5 region and the GS to GS feeding was found to be 87.5(25)%. The impact on the reactor antineutrino spectra calculated with the summation method is shown and discussed.

  13. Half metallic ferromagnetism in alkali metal nitrides MN (M = Rb, Cs): A first principles study

    Energy Technology Data Exchange (ETDEWEB)

    Murugan, A., E-mail: rrpalanichamy@gmail.com; Rajeswarapalanichamy, R., E-mail: rrpalanichamy@gmail.com; Santhosh, M., E-mail: rrpalanichamy@gmail.com; Sudhapriyanga, G., E-mail: rrpalanichamy@gmail.com [Department of Physics, N.M.S.S.V.N College, Madurai, Tamilnadu-625019 (India); Kanagaprabha, S. [Department of Physics, Kamaraj College, Tuticorin, Tamil Nadu-628003 (India)

    2014-04-24

    The structural, electronic and elastic properties of two alkali metal nitrides (MN: M= Rb, Cs) are investigated by the first principles calculations based on density functional theory using the Vienna ab-initio simulation package. At ambient pressure the two nitrides are stable in ferromagnetic state with CsCl structure. The calculated lattice parameters are in good agreement with the available results. The electronic structure reveals that these materials are half metallic in nature. A pressure-induced structural phase transition from CsCl to ZB phase is observed in RbN and CsN.

  14. Critical behavior of the three-dimensional Heisenberg antiferromagnet RbMnF3

    DEFF Research Database (Denmark)

    Coldea, R.; Cowley, R.A.; Perring, T.G.;

    1998-01-01

    The magnetic critical scattering of the near-ideal three-dimensional Heisenberg antiferromagnet (AF) RbMnF3 has been remeasured using neutron scattering. The critical dynamics has been studied in detail in the temperature range 0.77T(N) < T < 1.11T(N), where T-N is the Neel temperature. In agreem......The magnetic critical scattering of the near-ideal three-dimensional Heisenberg antiferromagnet (AF) RbMnF3 has been remeasured using neutron scattering. The critical dynamics has been studied in detail in the temperature range 0.77T(N)

  15. Very large optical rotation generated by Rb vapor in a multi-pass cell

    CERN Document Server

    Li, S; Sheng, D; Dural, N; Romalis, M V

    2011-01-01

    Paramagnetic Faraday rotation is a powerful technique for atom sensing widely used in quantum non-demolition measurements, fundamental symmetry tests, and other precision measurements. We demonstrate the use of a multi-pass optical cell for Faraday rotation spectroscopy and observe polarization rotation in excess of 100 radians from spin-polarized Rb vapor. Unlike optical cavities, multi-pass cells have a deterministic number of light passes and can be used to measure large optical rotations. We also observe a 10-fold suppression of transverse spin relaxation when Rb atoms are placed in a coherent superposition state immune to spin-exchange collisions.

  16. Syntheses and Structures of the New Quaternary Rubidium Selenides Rb Ln2CuSe 4 ( Ln=Sm, Gd, Dy), Rb 1.5Ln2Cu 2.5Se 5 ( Ln=Gd, Dy), and RbSm 2Ag 3Se 5

    Science.gov (United States)

    Huang, Fu Qiang; Ibers, James A.

    2000-05-01

    Six quaternary rubidium selenides RbLn2CuSe4 (Ln=Sm, Gd, Dy), Rb1.5Ln2Cu2.5Se5 (Ln=Gd, Dy), and RbSm2Ag3Se5 have been synthesized at 1073 K with the use of a reactive flux of Rb2Se3. At 153 K all compounds contain four formula units in orthorhombic unit cells. The isostructural compounds RbLn2CuSe4 crystallize in space group Cmcm; the isostructural compounds Rb1.5Ln2Cu2.5Se5 crystallize in space group Pnnm; RbSm2Ag3Se5 crystallizes in space group Cmcm. The cells of RbLn2CuSe4 are (Ln, a, b, c (Å)): Sm, 4.1834(9), 14.308(3), 14.439(3); Gd, 4.1568(8), 14.227(3), 14.409(3); Dy, 4.1237(10), 14.083(4), 14.291(3), and the corresponding R1 indices for the refined structures are 0.023, 0.029, and 0.039. The cells of Rb1.5Ln2Cu2.5Se5 are: Gd, 16.243(3), 16.449(3), 4.0980(7); Dy, 16.120(3), 16.292(3), 4.0610(8), and the R1 indices are 0.036 and 0.043. The cell of RbSm2Ag3Se5 is 4.3223(6), 15.229(2), 17.420(3) Å and the R1 index is 0.025. All six are closely related three-dimensional tunnel structures. Their anionic frameworks are built from LnSe6 octahedra and MSe4 (M=Cu, Ag) tetrahedra. RbLn2CuSe4 contains infinite 1∞[CuSe3] chains of vertex-sharing tetrahedra; Rb1.5Ln2Cu2.5Se5 also contains infinite chains of tetrahedra; and the tunnel in RbSm2Ag3Se5 holds one Rb+ cation in a 10-membered ring consisting of six Ag-Se bonds and four Sm-Se bonds. Rb1.5Dy2Cu2.5Se5, which is paramagnetic, obeys the Curie-Weiss law and has an effective magnetic moment of 10.63(4) μB.

  17. 人参皂苷Rb3的药理研究进展%Research Progress on Pharmacology of Ginsenoside Rb3

    Institute of Scientific and Technical Information of China (English)

    王凤; 周亚滨

    2012-01-01

    人参和三七在临床和日常生活中使用广泛,人参具有益气复脉、补脾益肺、生津安神的功效,三七具有化瘀止血、活血定痛的功效.本文对二者的有效成分人参皂苷Rb3在神经系统、心血管系统、血液系统等方面的药理研究文献资料进行了综述.%Ginseng and Panax are widely used in clinical and daily life. Ginseng can greatly tonify the original qi, tonify spleen and replenish lung , engender fluid and tranquilize. Panax can resolve stasis to stop bleeding and disperse swelling to stop pain. This article is about pharmacological studies on ginsenoside Rb3 which is an active ingredient of Ginseng and Panax in the nervous system, cardiovascular system, hematological system and other aspects. The results show ginsenoside Rb3 has the functions of protecting neurons and cardiomyocytes, anti - platelet aggregation and anti - virus effect .

  18. Two dimensional fluoride ion conductor RbSn {2}F {5} studied by impedance spectroscopy and {19}F, {119}Sn, and {87}Rb NMR

    Science.gov (United States)

    Yamada, K.; Ahmad, M. M.; Ogiso, Y.; Okuda, T.; Chikami, J.; Miehe, G.; Ehrenberg, H.; Fuess, H.

    2004-07-01

    RbSn2F5 is a two-dimensional fluoride ion conductor. It undergoes a first-order phase transition to a superionic state at 368 K. The structure of the low temperature phase has been determined from the Rietveld analysis of the X-ray powder diffraction. The dynamic properties of the fluoride ions in RbSn2F5 have been studied by impedance spectroscopy and solid state NMR. The dc ionic conductivity of this sample shows an abrupt increase at the phase transition temperature. We have obtained the hopping frequency and the concentration of the charge carriers (F- ions) at different temperatures from the analysis of the conductivity spectra using Almond-West formalism. The estimated values of the charge carriers’ concentration agree well with that determined from the structure and were found to be independent of temperature. The relatively small value of the power-law exponent, n ≈ 0.55, supports the two-dimensional property of the investigated material. Furthermore, 19F NMR with simulation has suggested the diffusive motions of the fluoride ions between different sites. In contrast, 119Sn and 87Rb NMR spectra below 250 K supported the intrinsic disordered nature due to the random distribution of the fluoride ion vacancies.

  19. Ginsenoside Rb1 Preconditioning Enhances eNOS Expression and Attenuates Myocardial Ischemia/Reperfusion Injury in Diabetic Rats

    Directory of Open Access Journals (Sweden)

    Rui Xia

    2011-01-01

    Full Text Available Diabetes mellitus is associated with decreased NO bioavailability in the myocardium. Ginsenoside Rb1 has been shown to confer cardioprotection against ischemia reperfusion injury. The aim of this study was to investigate whether Ginsenoside Rb1 exerts cardioprotective effects during myocardial ischemia-reperfusion in diabetic rats and whether this effect is related to increase the production of NO via enhancing eNOS expression in the myocardium. The myocardial I/R injury were induced by occluding the left anterior descending artery for 30 min followed by 120 min reperfusion. An eNOS inhibitor L-NAME or Rb1 were respectively administered 25 min or 10 min before inducing ischemia. Ginsenoside Rb1 preconditioning reduced myocardial infarct size when compared with I/R group. Ginsenoside Rb1 induced myocardial protection was accompanied with increased eNOS expression and NO concentration and reduced plasma CK and LDH (P<0.05. Moreover, the myocardial oxidative stress and tissue histological damage was attenuated by Ginsenoside Rb1 (P<0.05. L-NAME abolished the protective effects of Ginsenoside Rb1. It is concluded that Ginsenoside Rb1 protects against myocardium ischemia/reperfusion injury in diabetic rat by enhancing the expression of eNOS and increasing the content of NO as well as inhibiting oxidative stress.

  20. High expression of RbAp46 gene in patients with acute leukemia or chronic myelogenous leukemia in blast crisis

    Institute of Scientific and Technical Information of China (English)

    HU Shao-yan; CHEN Zi-xing; GU Wei-ying; CEN Jian-nong; ZHAO Ye

    2005-01-01

    @@ The retinoblastoma (Rb) suppressor associated protein 46 (RbAp46) also named retinoblastoma binding protein 7 (RBBP7) was first identified as a protein in HeLa cells that binds to an Rb affinity column.RbAp46 has been shown to be a core component of the mSin3 histone deacetylase (HDAC) complex1 and NuRD ( a multi-subunit complex containing chromosome-remodeling activity).2 RbAp46 is also known as the histone acetyltransferase (HAT) type B subunit 2.3 Thus,RbAp46 functions as a core-histone-binding subunit that targets chromatin assembly factors,chromatin-remodeling factors,histone acetyltransferase and deacetylase to their histone substrates in chromatin.Guan et al4 isolated RbAp46 as a downstream target gene of the Wilms'tumor suppressor gene (WT1),mediating the function of WT1.It has been discovered recently that RbAp46 specifically interacts with the BRCT domain of breast cancer and ovarian cancer susceptibility gene BRCA1 and modulates its transcriptional transactivation activity.5

  1. 75 FR 69611 - Airworthiness Directives; Rolls-Royce plc RB211-Trent 768, 772, and 772B Turbofan Engines

    Science.gov (United States)

    2010-11-15

    ... Directives; Rolls-Royce plc RB211-Trent 768, 772, and 772B Turbofan Engines AGENCY: Federal Aviation... require the same initial and repetitive visual inspections of Rolls-Royce plc RB211-Trent 768 and 772... directive (AD) 98-09-27, Amendment 39-10508 (63 FR 24911, May 6, 1998): Rolls-Royce plc: Docket No....

  2. Quantitative accuracy of denoising techniques applied to dynamic 82Rb myocardial blood flow PET/CT scans

    DEFF Research Database (Denmark)

    Harms, Hans; Tolbod, Lars Poulsen; Bouchelouche, Kirsten;

    Objectives: Absolute quantification of myocardial blood flow (MBF) using 82Rb has shown promising results for diagnosing coronary artery disease. The short half-life of 82Rb, however, requires a high administered dose in order to get sufficient counting statistics at later timepoints...

  3. Assessment of inverse correlation of p16 and pRb expression in carcinoma ex pleomorphic adenoma.

    Science.gov (United States)

    Tarakji, B; Alenzi, F; Al-Khuraif, A A

    2013-06-01

    Published data indicate that an inverse correlation has been identified in some tumours such as ovarian cancer and laryngeal squamous carcinoma. This study aimed to characterize alteration in the immunohistochemical expression of p16 and p Rb in carcinoma ex pleomorphic adenoma, and to assess the inverse correlation between p16 and pRb in carcinoma ex pleomorphic adenoma. A selected series of 27 cases of carcinoma ex pleomorphic adenoma were examined at Alfarabi Dental School in 2012. The results showed an inverse correlation between p16 (normal expression) and pRb (mutated) in 15 cases. Also 3 cases showed an inverse correlation between p16 (mutated) and pRb (normal expression). p16 and pRb (both proteins with normal expression) were identified in 3 cases. p16 and pRb (both proteins inactivated) were identified in 6 cases. This study suggests the alteration of p16 and pRb expression has been detected in carcinoma ex pleomorphic adenomas. They mentioned that if the function of one gene such as p16 or pRb was abrogated the other gene would be overexpressed or unaffected ini 18 out of 27 cases.

  4. Susceptibility of pRb-deficient epidermis to chemical skin carcinogenesis is dependent on the p107 allele dosage.

    Science.gov (United States)

    Santos, Mirentxu; Ruiz, Sergio; Lara, M Fernanda; Segrelles, Carmen; Moral, Marta; Martínez-Cruz, Ana Belén; Ballestín, Claudio; Lorz, Corina; García-Escudero, Ramón; Paramio, Jesús M

    2008-11-01

    Functional inactivation of the pRb-dependent pathway is a general feature of human cancer. However, only a reduced spectrum of tumors displays inactivation of the Rb gene. This can be attributed, at least partially, to the possible overlapping functions carried out by the related retinoblastoma family members p107 and p130. We observed that loss of pRb in epidermis, using the Cre/LoxP technology, results in proliferation and differentiation defects. These alterations are partially compensated by the elevation in the levels of p107. Moreover, epidermis lacking pRb and p107, but not pRb alone, develops spontaneous tumors, and double deficient primary keratinocytes are highly susceptible to Ha-ras-induced transformation. Two-stage chemical carcinogenesis experiments in mice lacking pRb in epidermis revealed a reduced susceptibility in papilloma formation and an increase in the malignant conversion. We have now explored whether the loss of one p107 allele, inducing a decrease in the levels of p107 up to normal levels could restore the susceptibility of pRb-deficient skin to two-stage protocol. We observed partial restoration in the incidence, number, and size of tumors. However, there is no increased malignancy despite sustained p53 activation. We also observed a partial reduction in the levels of proapoptotic proteins in benign papillomas. These data confirm our previous suggestions on the role of p107 as a tumor suppressor in epidermis in the absence of pRb.

  5. Ginsenosides Rb1 and Rg1 Stimulate Melanogenesis in Human Epidermal Melanocytes via PKA/CREB/MITF Signaling

    Directory of Open Access Journals (Sweden)

    Mao Lin

    2014-01-01

    Full Text Available Reduced or defective melanin skin pigmentation may cause many hypopigmentation disorders and increase the risk of damage to the skin triggered by UV irradiation. Ginsenosides Rb1 and Rg1 have many molecular targets including the cAMP-response element-binding protein (CREB, which is involved in melanogenesis. This study aimed to investigate the effects of ginsenosides Rb1 and Rg1 on melanogenesis in human melanocytes and their related mechanisms. The effects of Rb1 and Rg1 on cell viability, tyrosinase activity, cellular melanin content and protein levels of tyrosinase, microphthalmia-associated transcription factor (MITF, and activation of CREB in melanocytes were assessed. Results showed that Rb1 or Rg1 significantly increased cellular melanin content and tyrosinase activity in a dose-dependent manner. By contrast, the cell viability of melanocytes remained unchanged. After exposure to Rb1 or Rg1, the protein levels of tyrosinase, MITF, and phosphorylated CREB were significantly increased. Furthermore, pretreatment with the selective PKA inhibitor H-89 significantly blocked the Rb1- or Rg1-induced increase of melanin content. These findings indicated that Rb1 and Rg1 increased melanogenesis and tyrosinase activity in human melanocytes, which was associated with activation of PKA/CREB/MITF signaling. The effects and mechanisms of Rb1 or Rg1 on skin pigmentation deserve further study.

  6. Expression of p16 gene and Rb protein in gastric carcinoma and their clinicopathological significance

    Institute of Scientific and Technical Information of China (English)

    Xiu-Sheng He; Ying-Hui Rong; Qi Su; Qiao Luo; Dong-Mei He; Yan-Lan Li; Yan Chen

    2005-01-01

    AIM: To analyze the correlation between the protein expression of p16 and Rb genes in gastric carcinoma (GC),to investigate the role of p16 gene in invasion and lymph node metastasis of GC, and to examine the deletion and mutation in exon 2 of p16 gene in GC.METHODS: The protein expression of p16 and Rb genes was examined by streptavidin-peroxidase conjugated method (S-P) in normal gastric mucosa, dysplastic gastric mucosa and GC. The deletion and mutation of p16 gene were examined by polymerase chain reaction (PCR) and polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) respectively in normal gastric mucosa and GC.RESULTS: The positive rates of P16 and Rb protein expression respectively were 96% (77/80) and 99%(79/80) in normal gastric mucosa, 92% (45/50) and 80%(40/50) in dysplastic gastric mucosa, 48% (58/122) and 60% (73/122) in GC. The positive rates of P16 and Rb protein expression in GC were significantly lower than that in normal gastric mucosa and dysplastic gastric mucosa (P<0.05). The positive rate of P16 protein expression in mucoid carcinoma (10%, 1/10) was significantly lower than that in poorly differentiated carcinoma (51%, 21/41),undifferentiated carcinoma (58%, 15/26) and signet ring cell carcinoma (62%, 10/16) (P<0.05). The positive rates of P16 protein in 30 cases of paired primary and lymph node metastatic GC were 47% (14/30) and 17% (5/30)respectively, being significantly lower in the later than in the former (P<0.05). There was no mutation in exon 2 of p16 gene in the 25 freshly resected primary GCs. But five cases in the 25 freshly resected primary GCs displayed deletion in exon 2 of p16 gene. The positive rate of both P16 and Rb proteins was 16% (14/90), and the negative rate of both P16 and Rb proteins was 8% (7/90) in 90GCs. The rate of positive P16 protein with negative Rb protein was 33% (30/90). The rate of negative P16 protein with positive Rb protein was 43% (39/90). There was reverse correlation

  7. Photoassociation of ultracold LiRb* molecules: Observation of high efficiency and unitarity-limited rate saturation

    Science.gov (United States)

    Dutta, Sourav; Lorenz, John; Altaf, Adeel; Elliott, D. S.; Chen, Yong P.

    2014-02-01

    We report the production of ultracold heteronuclear Li7Rb85 molecules in excited electronic states by photoassociation (PA) of ultracold Li7 and Rb85 atoms. PA is performed in a dual-species Li7-Rb85 magneto-optical trap (MOT) and the PA resonances are detected using trap loss spectroscopy. We identify several strong PA resonances below the Li (2s 2S1/2) + Rb (5p 2P3/2) asymptote and experimentally determine the long range C6 dispersion coefficients. We find a molecule formation rate (PLiRb) of 3.5 × 107 s-1 and a PA rate coefficient (KPA) of 1.3 × 10-10 cm3/s, the highest among heteronuclear bi-alkali-metal molecules. At large PA laser intensity we observe the saturation of the PA rate coefficient (KPA) close to the theoretical value at the unitarity limit.

  8. Photoassociation of ultracold LiRb* molecules: observation of high efficiency and unitarity-limited rate saturation

    CERN Document Server

    Dutta, Sourav; Altaf, Adeel; Elliott, D S; Chen, Yong P

    2013-01-01

    We report the production of ultracold heteronuclear 7Li85Rb molecules in excited electronic states by photoassociation (PA) of ultracold 7Li and 85Rb atoms. PA is performed in a dual-species 7Li-85Rb magneto-optical trap (MOT) and the PA resonances are detected using trap loss spectroscopy. We identify several strong PA resonances below the Li (2s 2S1/2) + Rb (5p 2P3/2) asymptote and experimentally determine the long range C6 dispersion coefficients. We find a molecule formation rate (P_LiRb) of 3.5x10^7 s^-1 and a PA rate coefficient (K_PA) of 1.3x10^-10 cm^3/s, the highest among heteronuclear bi-alkali molecules. At large PA laser intensity, we observe the saturation of the PA rate coefficient (K_PA) close to the theoretical value at the unitarity limit.

  9. Identification of target genes of the p16INK4A-pRB-E2F pathway

    DEFF Research Database (Denmark)

    Vernell, Richard; Helin, Kristian; Müller, Heiko

    2003-01-01

    Deregulation of the retinoblastoma protein (pRB) pathway is a hallmark of human cancer. The core members of this pathway include the tumor suppressor protein, pRB, which through binding to a number of cellular proteins, most notably members of the E2F transcription factor family, regulates...... progression through the cell division cycle. With the aim of identifying transcriptional changes provoked by deregulation of the pRB pathway, we have used cell lines that conditionally express a constitutively active phosphorylation site mutant of pRB (pRBDeltaCDK) or p16INK4A (p16). The expression of p...... as physiological targets of the pRB pathway, and the further characterization of these genes should provide insights into how this pathway controls proliferation. We show that Gibbs sampling detects enrichment of several sequence motifs, including E2F consensus binding sites, in the upstream regions of these genes...

  10. Sodium butyrate modulates pRb phosphorylation and induces cell death in human vestibular schwannomas in vitro.

    Science.gov (United States)

    Mitra, Rohan; Devi, B Indira; Gope, Mohan L; Subbakrishna, D K; Gope, Rajalakshmi

    2012-01-01

    In the present study, effect of Na-Bu on the pRb phosphorylation was analysed in the primary cultures of 12 VS tumors. Primary cultures of VS tumors were established from the fresh tumor tissues removed surgically and were treated with Na-Bu. Na-Bu treatment for 48 h led to morphological changes and apoptotic cell death in VS tumor cells. Na-Bu treatment decreased level of total pRb and phosphorylated form of pRb and caused specific dephosphorylation at Ser 249/Thr 252 and Ser 567. In the untreated and Na-Bu treated cells (when present), pRb was localised in the nucleus. Moreover, in Na-Bu treated cells the nucleus appeared highly condensed as compared to untreated cells. Results of the present study indicated that Na-Bu treatment modulated pRb phosphorylation status and caused apoptotic cell death in VS tumors.

  11. High-accuracy measurement of the {sup 87}Rb ground-state hyperfine splitting in an atomic fountain

    Energy Technology Data Exchange (ETDEWEB)

    Bize, S.; Sortais, Y.; Clairon, A. [Observatoire de Paris (France). BNM-LPTF; Santos, M.S. [Inst. de Fisica de Sao Carlos-USP, Dept. de Fisica e Ciencia dos Materiais, Sao Carlos (Brazil); Mandache, C. [Inst. National de Fizica Laserilor, Plasmei si Radiatiei, Bucuresti, Magurele (Romania); Salomon, C. [Lab. Kastler Brossel, Ecole Normale Superieure, Paris (France)

    1999-03-01

    We describe the operation of a laser-cooled rubidium {sup 87}Rb frequency standard. We present a new measurement of the {sup 87}Rb hyperfine frequency with a 1.3 x 10{sup -14} relative accuracy, by comparison with a Cs fountain primary standard. The measured {sup 87}Rb ground-state hyperfine splitting is {nu}{sup {sub 87}}{sub Rb} = 6 834 682 610.90429(9) Hz. This value differs from previously published values (see Essen L., Hope E. G. and Sutcliffe D. (1961); Penselin S., Moran T., Cohen W. and Winkler G. (1962); Arditi M. and Cerez P. (1972)) by about 2-3 Hz and is 10{sup 4} times more accurate. Because of the low collisional shift in {sup 87}Rb, future improvements may lead to a stability of 1 x 10{sup -14}{tau}{sup -1/2} and a relative accuracy in the 10{sup -17} range. (orig.) 23 refs.

  12. Observation of electromagnetically induced transparency in six-level Rb atoms and theoretical simulation of the observed spectra

    Science.gov (United States)

    Bhattacharyya, Dipankar; Ghosh, Arindam; Bandyopadhyay, Amitava; Saha, Satyajit; De, Sankar

    2015-09-01

    We report the observation of electromagnetically induced transparency (EIT) in a six-level Λ-type system in atomic Rb vapor containing both 87Rb and 85Rb. The experimental observation includes five velocity selective optically pumped (VSOP) absorption dips for both 87Rb and 85Rb. The EIT signal appears on the background of one such VSOP absorption dips. The measured EIT linewidth ({Γ }t) shows sub-natural ({Γ }t \\lt Γ ) values for both lower and higher values of pump Rabi-frequencies. The density matrix based theoretical model for the six-level system is developed and solved numerically by taking into account the Doppler broadening. A complete analytical solution (non perturbative) for a three level Λ-type system has been obtained and compared with the experimentally observed sub-natural EIT linewidth. The simulated spectra are in good agreement with the experimental findings.

  13. Enzymatic formation of compound-K from ginsenoside Rb1 by enzyme preparation from cultured mycelia of Armillaria mellea

    Science.gov (United States)

    Upadhyaya, Jitendra; Kim, Min-Ji; Kim, Young-Hoi; Ko, Sung-Ryong; Park, Hee-Won; Kim, Myung-Kon

    2015-01-01

    Background Minor saponins or human intestinal bacterial metabolites, such as ginsenosides Rg3, F2, Rh2, and compound K, are more pharmacologically active than major saponins, such as ginsenosides Rb1, Rb2, and Rc. In this work, enzymatic hydrolysis of ginsenoside Rb1 was studied using enzyme preparations from cultured mycelia of mushrooms. Methods Mycelia of Armillaria mellea, Ganoderma lucidum, Phellinus linteus, Elfvingia applanata, and Pleurotus ostreatus were cultivated in liquid media at 25°C for 2 wk. Enzyme preparations from cultured mycelia of five mushrooms were obtained by mycelia separation from cultured broth, enzyme extraction, ammonium sulfate (30–80%) precipitation, dialysis, and freeze drying, respectively. The enzyme preparations were used for enzymatic hydrolysis of ginsenoside Rb1. Results Among the mushrooms used in this study, the enzyme preparation from cultured mycelia of A. mellea (AMMEP) was found to convert ginsenoside Rb1 into compound K with a high yield, while those from G. lucidum, P. linteus, E. applanata, and P. ostreatus produced remarkable amounts of ginsenoside Rd from ginsenoside Rb1. The enzymatic hydrolysis pathway of ginsenoside Rb1 by AMMEP was Rb1 → Rd → F2 → compound K. The optimum reaction conditions for compound K formation from ginsenoside Rb1 were as follows: reaction time 72–96 h, pH 4.0–4.5, and temperature 45–55°C. Conclusion AMMEP can be used to produce the human intestinal bacterial metabolite, compound K, from ginsenoside Rb1 with a high yield and without food safety issues. PMID:27158230

  14. Functional ablation of pRb activates Cdk2 and causes antiestrogen resistance in human breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Hemant Varma

    Full Text Available Estrogens are required for the proliferation of hormone dependent breast cancer cells, making estrogen receptor (ER positive tumors amenable to endocrine therapies such as antiestrogens. However, resistance to these agents remains a significant cause of treatment failure. We previously demonstrated that inactivation of the retinoblastoma protein (pRb family tumor suppressors causes antiestrogen resistance in MCF-7 cells, a widely studied model of estrogen responsive human breast cancers. In this study, we investigate the mechanism by which pRb inactivation leads to antiestrogen resistance. Cdk4 and cdk2 are two key cell cycle regulators that can phosphorylate and inactivate pRb, therefore we tested whether these kinases are required in cells lacking pRb function. pRb family members were inactivated in MCF-7 cells by expressing polyomavirus large tumor antigen (PyLT, and cdk activity was inhibited using the cdk inhibitors p16(INK4A and p21(Waf1/Cip1. Cdk4 activity was no longer required in cells lacking functional pRb, while cdk2 activity was required for proliferation in both the presence and absence of pRb function. Using inducible PyLT cell lines, we further demonstrated that pRb inactivation leads to increased cyclin A expression, cdk2 activation and proliferation in antiestrogen arrested cells. These results demonstrate that antiestrogens do not inhibit cdk2 activity or proliferation of MCF-7 cells in the absence of pRb family function, and suggest that antiestrogen resistant breast cancer cells resulting from pRb pathway inactivation would be susceptible to therapies that target cdk2.

  15. pRb2/p130 protein expression and RBL2 mutation analysis in Burkitt lymphoma from Uganda

    Directory of Open Access Journals (Sweden)

    Wabinga Henry

    2009-08-01

    Full Text Available Abstract Background The members of the retinoblastoma protein family, pRb, p107 and pRb2 (p130, are central players in controlling the cell cycle. Whereas disturbed function of pRb is commonly seen in human cancers, it is still an open question whether pRb2 is involved in tumorigenic processes. However, altered subcellular localization of pRb2 and mutations in the pRb2-encoding gene RBL2 have been described for some tumours, including Burkitt lymphomas (BL. Methods We retrieved 51 biopsy specimens of endemic BL cases from Uganda. The expression of pRb2 was determined by immunohistochemistry. Exons 19–22 of the RBL2 gene, the region known to contain a nuclear localization signal, were screened for mutations by PCR amplification and direct DNA sequencing. Results Nearly all of our cases (84.0% were positive for pRb2 protein expression although this protein is a marker for growth arrest and Burkitt lymphoma is characterized by a high proliferation rate. Of the positive cases, 73.8% were scored as expressing the protein at a high level. Subcellular pRb2 localization was predominantly nuclear and no cases with expression restricted to the cytoplasm were observed. We did not detect any RBL2 mutations in the part of the gene that encodes the C-terminal end of the protein. Conclusion The majority of endemic BL cases from Uganda express pRb2, but somatic RBL2 mutations affecting the protein's nuclear localization signal appear to be rare.

  16. Functional ablation of pRb activates Cdk2 and causes antiestrogen resistance in human breast cancer cells.

    Science.gov (United States)

    Varma, Hemant; Skildum, Andrew J; Conrad, Susan E

    2007-12-05

    Estrogens are required for the proliferation of hormone dependent breast cancer cells, making estrogen receptor (ER) positive tumors amenable to endocrine therapies such as antiestrogens. However, resistance to these agents remains a significant cause of treatment failure. We previously demonstrated that inactivation of the retinoblastoma protein (pRb) family tumor suppressors causes antiestrogen resistance in MCF-7 cells, a widely studied model of estrogen responsive human breast cancers. In this study, we investigate the mechanism by which pRb inactivation leads to antiestrogen resistance. Cdk4 and cdk2 are two key cell cycle regulators that can phosphorylate and inactivate pRb, therefore we tested whether these kinases are required in cells lacking pRb function. pRb family members were inactivated in MCF-7 cells by expressing polyomavirus large tumor antigen (PyLT), and cdk activity was inhibited using the cdk inhibitors p16(INK4A) and p21(Waf1/Cip1). Cdk4 activity was no longer required in cells lacking functional pRb, while cdk2 activity was required for proliferation in both the presence and absence of pRb function. Using inducible PyLT cell lines, we further demonstrated that pRb inactivation leads to increased cyclin A expression, cdk2 activation and proliferation in antiestrogen arrested cells. These results demonstrate that antiestrogens do not inhibit cdk2 activity or proliferation of MCF-7 cells in the absence of pRb family function, and suggest that antiestrogen resistant breast cancer cells resulting from pRb pathway inactivation would be susceptible to therapies that target cdk2.

  17. Expression of pRb, p53, p16 and cyclin D1 and their clinical implications in urothelial carcinoma.

    Science.gov (United States)

    Lee, Kyungji; Jung, Eun Sun; Choi, Young-Jin; Lee, Kyo Young; Lee, Ahwon

    2010-10-01

    The aim of this study was to assess immunohistochemical expression of p53, pRb, p16, and cyclin D1, alone or in combination, as prognostic indicators and to investigate their correlation with clinocopathologic features of urothelial carcinoma. Immunohistochemical staining for p53, pRb, p16, and cyclin D1 was performed on a tissue microarray from 103 patients with urothelial carcinoma who underwent radical cystectomy. Of the patient samples analyzed, 36 (35%), 61 (59%), 47 (46%) and 30 (29%) had altered expression of p53, pRb, p16, and cyclin D1, respectively. Abnormal expression of p53 and pRb correlated with depth of invasion (P=0.040 and P=0.044, respectively). Cyclin D1 expression was associated with tumor stage and recurrence (P=0.017 and P=0.036, respectively). Altered pRb was significantly correlated with overall survival (P=0.040). According to the expression pattern of pRb and p53, p53/pRb (altered/normal) had worse survival than p53/pRb (normal/altered) (P=0.022). Alteration of all markers had worse survival than all normal (P=0.029). As determined by multivariate analysis, tumor stage, lymph node metastasis and the combined expression of p53 and pRb are independent prognostic factors. In conclusion, immunohistochemical evaluation of cell cycle regulators, especially the p53/pRb combination, might be useful in planning appropriate treatment strategies.

  18. Clinicopathological significance of p16, cyclin D1, Rb and MIB-1 levels in skull base chordoma and chondrosarcoma

    Institute of Scientific and Technical Information of China (English)

    Jun-qi Liu; Qiu-hang Zhang; Zhen-lin Wang

    2015-01-01

    Objective: To investigate the expression of p16, cyclin D1, retinoblastoma tumor suppressor protein (Rb) and MIB-1 in skull base chordoma and chondrosarcoma tissues, and to determine the clinicopathological significance of the above indexes in these diseases.Methods: A total of 100 skull base chordoma, 30 chondrosarcoma, and 20 normal cartilage tissue samples were analyzed by immunohistochemistry.The expression levels of p16, cyclinD1,Rb and MIB-1 proteins were assessed for potential correlation with the clinicopathological features.Results: As compared to normal cartilage specimen (control), there was decreased expression of p16, and increased expression of cyclin D1, Rb and MIB-1 proteins, in both skull base chordoma and chondrosarcoma specimens.MIB-1 LI levels were significantly increased in skull base chordoma specimens with negative expression of p16, and positive expression of cyclin D1 and Rb (P < 0.05).Significantly elevated MIB-1 LI was also detected in skull base chondrosarcoma tissues, while there was negative expression of p16, cyclin D1 and Rb (P < 0.05).In skull base chordoma, p16 negatively correlated with cyclin D1 and Rb, while cyclin D1 positively correlated with Rb.Additionally, p16, cyclin D1, Rb, or MIB-1 expression showed no correlation with age, gender, or pathological classification of patients with skull base chordoma (P > 0.05).However, p16 and MIB-1 levels correlated with the intradural invasion, and expression of p16, Rb and MIB-1 correlated with the number of tumor foci (P < 0.05).Further, the expression of p16 and MIB-1 appeared to correlate with the prognosis of patients with skull base chordoma.Conclusions: The abnormal expression of p16, cyclin D1 and Rb proteins might be associated with the tumorigenesis of skull base chordoma and chondrosarcoma.

  19. Beta-decay half-lives of {sup 70}Kr and {sup 74}Rb

    Energy Technology Data Exchange (ETDEWEB)

    Oinonen, M. E-mail: markku.oinonen@cern.ch; Aeystoe, J.; Koester, U.; Huikari, J.; Jokinen, A.; Nieminen, A.; Peraejaervi, K.; Baumann, P.; Didierjean, F.; Huck, A.; Knipper, A.; Ramdhane, M.; Walter, G.; Huyse, M.; Van Duppen, P.; Marguier, G.; Novikov, Yu.; Popov, A.; Seliverstov, D.M.; Schatz, H

    2002-04-22

    Beta-decay half-lives of two nuclei close to N=Z line, {sup 70}Kr and {sup 74}Rb, have been measured at the ISOLDE mass-separator facility at CERN. Importance of these half-lives on two ingredients explaining existence and development of the Universe, the astrophysical nucleosynthesis and the Standard Model, are discussed.

  20. A comprehensive modular map of molecular interactions in RB/E2F pathway.

    Science.gov (United States)

    Calzone, Laurence; Gelay, Amélie; Zinovyev, Andrei; Radvanyi, François; Barillot, Emmanuel

    2008-01-01

    We present, here, a detailed and curated map of molecular interactions taking place in the regulation of the cell cycle by the retinoblastoma protein (RB/RB1). Deregulations and/or mutations in this pathway are observed in most human cancers. The map was created using Systems Biology Graphical Notation language with the help of CellDesigner 3.5 software and converted into BioPAX 2.0 pathway description format. In the current state the map contains 78 proteins, 176 genes, 99 protein complexes, 208 distinct chemical species and 165 chemical reactions. Overall, the map recapitulates biological facts from approximately 350 publications annotated in the diagram. The network contains more details about RB/E2F interaction network than existing large-scale pathway databases. Structural analysis of the interaction network revealed a modular organization of the network, which was used to elaborate a more summarized, higher-level representation of RB/E2F network. The simplification of complex networks opens the road for creating realistic computational models of this regulatory pathway.

  1. Polarizabilities and tune-out wavelengths of the hyperfine ground states of $^{87,85}$Rb

    CERN Document Server

    Wang, Xia; Xie, Lu-You; Zhang, Deng-Hong; Dong, Chen-Zhong

    2016-01-01

    The static and dynamic polarizabilities, and the tune-out wavelengths of the ground state of Rb and the hyperfine ground states of $^{87, 85}$Rb have been calculated by using relativistic configuration interaction plus core polarization(RCICP) approach. It is found that the first primary tune-out wavelengths of the $ 5s_{1/2}, F=1, 2 $ states of $ ^{87}$Rb are 790.018187(193) nm and 790.032602(193) nm severally, where the calculated result for the $ 5s_{1/2}, F=2 $ state is in good agreement with the latest high-precision measurement 790.032388(32) nm [Phys. Rev. A 92, 052501 (2015)]. Similarly, the first primary tune-out wavelengths of the $ 5s_{1/2}, F=2, 3 $ states of $^{85}$Rb are 790.023515(218) nm and 790.029918(218) nm respectively. Furthermore, the tune-out wavelengths for the different magnetic sublevels $ M_{F}$ of each hyperfine level $F$ are also determined by considering the contributions of tensor polarizabilities.

  2. Photoconductivity and light stimulated contact potentials in β-RbAg4I5

    NARCIS (Netherlands)

    Murakhovsky, V.G.; Gool, W. van

    1984-01-01

    Photoconductivity and photoelectric effects have been established in thin polycrystalline films of β - RbAg4I5. The spectral and the temperature dependence of the phenomena have been studied. The results are interpreted using a model in which ionic processes dominate in the photoconductivity when th

  3. Derivation of Apollo 14 High-Al Basalts at Discrete Times: Rb-Sr Isotopic Constraints

    Science.gov (United States)

    Hui, H.; Neal, C. R.; Shih, C.-Y.; Nyquist, L. E.

    2012-03-01

    Four eruption episodes were identified for A-14 high-Al basalts. Rb-Sr isotopic data and ITE ratios show that their parental melt compositions of are correlated through mixing of evolved components with a relatively primitive magma ocean cumulate.

  4. RubiShort: Reducing scan time in 82Rb heart scans to minimize movements artifacts

    DEFF Research Database (Denmark)

    Madsen, Jeppe; Vraa, Kaspar J.; Harms, Hans

    Aim: Relative and absolute myocardial blood flow (MBF) can derived from a single 82Rb PET/CT scan using list mode data to extract both static and dynamic PET series. However, patient movement and changes in breathing pattern, especially during pharmacological stress, reduce the quality of the sca...

  5. The effect of sterol structure on the permeability of lipomes to glucose, glycerol and Rb+

    NARCIS (Netherlands)

    Demel, R.A.; Bruckdorfer, K.R.; Deenen, L.L.M. van

    1972-01-01

    1. 1. The effect of 3β-, 3α-hydroxysterol and ketosteroids on the permeability properties of (egg lecithin) liposomes towards glucose, glycerol and Rb+ has been studied. 2. 2. The 3β-hydroxysterols, cholesterol, cholestanol, lathosterol, 7-dehydrocholesterol and B-norcholesterol affect the most pro

  6. Electronic properties and orbital-filling mechanism in Rb-intercalated copper phthalocyanine

    NARCIS (Netherlands)

    Evangelista, F.; Gotter, R.; Mahne, N.; Nannarone, S.; Ruocco, A.; Rudolf, P.

    2008-01-01

    The evolution of the electronic properties of a thin film of copper phthalocyanine deposited on Al(100) and progressively intercalated with rubidium atoms was followed by photoemission and X-ray absorption spectroscopies. Electron donation from the Rb atoms to the C32H16N8Cu molecules results in the

  7. Optical conductivity in A3C60 (A=K, Rb)

    NARCIS (Netherlands)

    Brink, J. van den; Gunnarsson, O.; Eyert, V.

    1997-01-01

    Published in: Phys. Rev. B 57 (1998) 2163-2167 Citing articles (CrossRef) citations recorded in [Science Citation Index] Abstract: We study the optical conductivity in A3C60 (A =K, Rb). The effects of the electron-phonon interaction is included to lowest order in the coupling strength lambda. It is

  8. Loss of Rb proteins causes genomic instability in the absence of mitogenic signaling

    NARCIS (Netherlands)

    van Harn, Tanja; Foijer, Floris; van Vugt, Marcel; Banerjee, Ruby; Yang, Fentang; Oostra, Anneke; Joenje, Hans; te Riele, Hein

    2010-01-01

    Loss of G1/S control is a hallmark of cancer, and is often caused by inactivation of the retinoblastoma pathway. However, mouse embryonic fibroblasts lacking the retinoblastoma genes RB1, p107, and p130 (TKO MEFs) are still subject to cell cycle control: Upon mitogen deprivation, they enter and

  9. Formation of deeply bound LiRb molecules via photoassociation to near asymptotic states

    Science.gov (United States)

    Lorenz, John D.

    We present the results of a spectroscopic study LiRb molecules created via photoassociation (PA) to vibration levels of the 4(1) potential. Atoms are first cooled and trapped in a dual species 7Li/ 85Rb magneto-optical trap (MOT) at temperatures of ≈ 1 mK or less. In a cold sample of sufficient density, PA occurs when a resonant laser field induces a free-bound transition to create molecules in an excited electronic potential. After spontaneous emission the molecules decay to a mixture of free atoms and bound molecules depending on the Franck-Condon factors (FCFs) of the excited and ground state vibrational wavefunctions. While excited LiRb * has been previously detected by trap loss fluorescence detection, ionization spectroscopy is required to determine the population of ground state levels after decay. We detect ground state molecules via resonantly enhanced multiphoton ionization (REMPI) where a two photon ionization transition is enhanced by an intermediate resonance. The intermediate resonances match progressions from the D1pi and possibly B1Π potentials, many of which have known energies obtained from previous heat pipe experiments. This is contrary to the expectation that weakly bound LiRb * should primarily decay to weakly bound levels of the ground state and could point to a possible path for creating molecules in the rovibronic ground state.

  10. Static Myocardial Perfusion Imaging using denoised dynamic Rb-82 PET/CT scans

    DEFF Research Database (Denmark)

    Petersen, Maiken N.M.; Hoff, Camilla; Harms, Hans

    Introduction: Relative and absolute measures of myocardial perfusion are derived from a single 82Rb PET/CT scan. However, images are inherently noising due to the short half-life of 82Rb. We have previously shown that denoising techniques can be applied to dynamic 82Rb series with excellent....... Administered 82Rb dose was 1110 MBq. Denoising using HYPR-LR or Hotelling 3D algorithms was performed as post-processing on the dynamic images series. Static series were created by summing frames from 2.5-5 min. The image data was analysed in QPET (Cedars-Sinai). Relative segmental perfusion (normalized...... and Bland-Altman analysis. Results: For HYPR-LR, a good correlation was found for relative segmental perfusion for both stress (y=1.007x+0.313, R2=0.98) and rest (y=1.007x+ 0.421, R2=0.96) scans with negative bias of -0.79±1.44 and -0.90±1.63, respectively. Correlations for SSS (R2=0.94), SRS (R2=0.92), SDS...

  11. Unilateral kidney blood flow measurement using the 81Rb/81mKr ratio.

    NARCIS (Netherlands)

    van Herk, G.; de Zeeuw, D.

    1978-01-01

    A new method has been developed for the continuous quantification of kidney blood flow, utilizing the unique physical and biological properties of the radioactive tracer couple: rubidium-81/krypton-81m. After intravenous injection, 81Rb concentrates primarily in the kidneys, where it continuously ge

  12. Pocket proteins pRb and p107 are required for cortical lamination independent of apoptosis.

    Science.gov (United States)

    Svoboda, D S; Paquin, A; Park, D S; Slack, R S

    2013-12-01

    Pocket proteins (pRb, p107 and p130) are well studied in their role of regulating cell cycle progression. Increasing evidence suggests that these proteins also control early differentiation and even later stages of cell maturation, such as migration. However, pocket proteins also regulate apoptosis, and many of the developmental defects in knock out models have been attributed to increased cell death. Here, we eliminate ectopic apoptosis in the developing brain through the deletion of Bax, and show that pocket proteins are required for radial migration independent of their role in cell death regulation. Following loss of pRb and p107, a population of cortical neurons fails to pass through the intermediate zone into the cortical plate. Importantly, these neurons are born at the appropriate time and this migration defect cannot be rescued by eliminating ectopic cell death. In addition, we show that pRb and p107 regulate radial migration through a cell autonomous mechanism since pRb/p107 deficient neurons fail to migrate to the correct cortical layer within a wild type brain. These results define a novel role of pocket proteins in regulating cortical lamination through a cell autonomous mechanism independent of their role in apoptosis.

  13. Electronic structure and optical properties of RbPb2Br5

    Science.gov (United States)

    Lavrentyev, A. A.; Gabrelian, B. V.; Vu, V. T.; Denysyuk, N. M.; Shkumat, P. N.; Tarasova, A. Y.; Isaenko, L. I.; Khyzhun, O. Y.

    2016-04-01

    We report on density functional theory (DFT) calculations of the total and partial densities of states of rubidium dilead pentabromide, RbPb2Br5, employing the augmented plane wave+local orbitals (APW+lo) method as incorporated in the WIEN2k package. The calculations indicate that the Pb 6s and Br 4p states are the dominant contributors to the valence band: their main contributions are found to occur at the bottom and at the top of the band, respectively. Our calculations reveal that the bottom of the conduction band is formed predominantly from contributions of the unoccupied Pb 6p states. Data of total DOS derived in the present DFT calculations are found to be in agreement with the experimental X-ray photoelectron valence-band spectrum of this compound. The predominant contributions of the Br 4p states at the top of the valence band of rubidium dilead pentabromide are confirmed by comparison on a common energy scale of the X-ray emission band representing the energy distribution of the valence Br p states and the X-ray photoelectron valence-band spectrum of the RbPb2Br5 single crystal. Main optical characteristics of RbPb2Br5, such as dispersion of the absorption coefficient, real and imaginary parts of dielectric function, electron energy-loss spectrum, refractive index, extinction coefficient and optical reflectivity are explored for RbPb2Br5 by the DFT calculations.

  14. Accurate measurement of the sticking time and sticking probability of Rb atoms on a polydimethylsiloxane coating

    Energy Technology Data Exchange (ETDEWEB)

    Atutov, S. N., E-mail: atutovsn@mail.ru; Plekhanov, A. I. [Russian Academy of Sciences, Institute of Automation and Electrometry, Siberian Branch (Russian Federation)

    2015-01-15

    We present the results of a systematic study of Knudsen’s flow of Rb atoms in cylindrical capillary cells coated with a polydimethylsiloxane (PDMS) compound. The purpose of the investigation is to determine the characterization of the coating in terms of the sticking probability and sticking time of Rb on the two types of coating of high and medium viscosities. We report the measurement of the sticking probability of a Rb atom to the coating equal to 4.3 × 10{sup −5}, which corresponds to the number of bounces 2.3 × 10{sup 4} at room temperature. These parameters are the same for the two kinds of PDMS used. We find that at room temperature, the respective sticking times for high-viscosity and medium-viscosity PDMS are 22 ± 3 μs and 49 ± 6 μs. These sticking times are about million times larger than the sticking time derived from the surface Rb atom adsorption energy and temperature of the coating. A tentative explanation of this surprising result is proposed based on the bulk diffusion of the atoms that collide with the surface and penetrate inside the coating. The results can be important in many resonance cell experiments, such as the efficient magnetooptical trapping of rare elements or radioactive isotopes and in experiments on the light-induced drift effect.

  15. Heterogeneous photo-catalysis system for the degradation of azo dye Reactive Black 5 (RB5).

    Science.gov (United States)

    Huang, Yao-Hui; Wei, Hau-Cheng; Chen, Hung-Ta

    2012-01-01

    This study investigated a heterogeneous photo-catalysis system by introducing a novel brick supported iron oxide (denoted as B1) for the heterogeneous photoassisted degradation of Reactive Black 5 (RB5) at pH value from 3 to 7 in a three-phase (gas-liquid-solid) fluidized bed reactor (3P-FBR). Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray powder diffraction (XRD) and N(2) adsorption/desorption were used to characterize the B1 catalyst. The in situ formation of hydrogen peroxide and the depletion of oxalic acid by photochemical cycle of Fe(III)-oxalate complex under UVA light (λ = 365 nm) were studied. The effects of the solution pH and the concentration of oxalic acid on the degradation of RB5 are elucidated. About 90% decolourization was measured and 80% of the total organic carbon (TOC) was eliminated at pH 5.0 after 120 min for 20 mg/L RB5 in presence of 10 g/L B1 catalyst, 30 mg/L oxalic acid under 15 W UVA light. A mechanism for the photocatalytic degradation of RB5 over B1 catalyst is proposed.

  16. Frequent disruption of the RB1 pathway in diffuse large B cell lymphoma

    DEFF Research Database (Denmark)

    Møller, Michael Boe; Kania, P W; Ino, Y

    2000-01-01

    In the present study, we analysed 34 de novo diffuse large B cell lymphoma (DLCL) from a population-based lymphoma registry for alterations of the RB1 pathway at the genetic (RB1 and CDK4) and protein (pRb, cyclin D1, cyclin D3, CDK4, and E2F-1) level. The results were correlated with the data from...... downstream of exon 3 generating a novel splice signal. Seven tumours (21%) showed cyclin D3 overexpression, including all three thyroid lymphomas (P = 0.006). Cyclin D3 overexpression and p16INK4A/pRb aberrations were mutually exclusive, supporting an oncogenic role for cyclin D3 in DLCL. p16INK4A...... expression was associated with treatment failure (P = 0.020), and multivariate analysis of overall survival identified both low E2F-1 expression (relative risk = 6.9; P = 0.0037) and p16INK4A inactivation (relative risk = 3.3; P = 0.0247) as independent prognostic markers. These data support a role of E2F-1...

  17. Electronic properties and orbital-filling mechanism in Rb-intercalated copper phthalocyanine

    NARCIS (Netherlands)

    Evangelista, F.; Gotter, R.; Mahne, N.; Nannarone, S.; Ruocco, A.; Rudolf, P.

    2008-01-01

    The evolution of the electronic properties of a thin film of copper phthalocyanine deposited on Al(100) and progressively intercalated with rubidium atoms was followed by photoemission and X-ray absorption spectroscopies. Electron donation from the Rb atoms to the C32H16N8Cu molecules results in the

  18. Data of evolutionary structure change: 1C2RB-1COTA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1C2RB-1COTA 1C2R 1COT B A -GDAAKGEKEFNKCKTCHSIIAPDGTEIVKGAKTGPNLY...CA 337 THR CA 277 1COT A 37.21200180053711 -25.844999313354492 tion> -0.03099999949336...3 0.597000002861023 tion> 1.6881250143051147 3.115614891052246 ...

  19. RB036088 – a sugarcane cultivar for mechanical planting and harvesting

    Directory of Open Access Journals (Sweden)

    Edelclaiton Daros

    2016-12-01

    Full Text Available The sugarcane cultivar RB036088 is late-maturing, harvested from September to November in south-central Brazil, and is recommended for soils with medium to high fertility. It stands out with continuously high sugar yield over the harvests, longevity of the ratoon plants, high tillering capacity and can be harvested mechanically.

  20. MicroRNA-1 and-16 inhibit cardiomyocyte hypertrophy by targeting cyclins/Rb pathway

    Institute of Scientific and Technical Information of China (English)

    SHAN Zhi-xin; ZHU Jie-ning; TANG Chun-mei; ZHU Wen-si; LIN Qiu-xiong; HU Zhi-qin; FU Yong-heng; ZHANG Meng-zhen

    2016-01-01

    AIM:MicroRNAs ( miRNAs) were recognized to play significant roles in cardiac hypertrophy .But, it remains unknown whether cyclin/Rb pathway is modulated by miRNAs during cardiac hypertrophy .This study investigates the potential roles of microRNA-1 (miR-1) and microRNA-16 (miR-16) in modulating cyclin/Rb pathway during cardiomyocyte hypertrophy .METHODS:An animal model of hypertrophy was established in a rat with abdominal aortic constriction (AAC).In addition, a cell model of hypertrophy was also achieved based on PE-promoted neonatal rat ventricular cardiomyocyte .RESULTS:miR-1 and-16 expression were markedly de-creased in hypertrophic myocardium and hypertrophic cardiomyocytes in rats .Overexpression of miR-1 and -16 suppressed rat cardiac hypertrophy and hypertrophic phenotype of cultured cardiomyocytes .Expression of cyclins D1, D2 and E1, CDK6 and phosphorylated pRb was increased in hypertrophic myocardium and hypertrophic cardiomyocytes , but could be reversed by enforced expression of miR-1 and -16.CDK6 was validated to be modulated post-transcriptionally by miR-1, and cyclins D1, D2 and E1 were further validated to be modulated post-transcriptionally by miR-16.CONCLUSION: Attenuations of miR-1 and -16 provoke cardiomyocyte hypertrophy via derepressing the cyclins D1, D2, E1 and CDK6, and activating cyclin/Rb pathway.

  1. Ethnic variations of a retinoblastoma susceptibility gene (RB1) polymorphism in eight Asian populations

    Indian Academy of Sciences (India)

    Priya Kadam-Pai; Xin-Yi Su; Jasmin Jiji Miranda; Agustinus Soemantri; Nilmani Saha; Chew-Kiat Heng; Poh-San Lai

    2003-04-01

    An A → G single nucleotide polymorphism (SNP) at nucleotide 153,104 in the retinoblastoma susceptibility locus (RB1) at 13q14 was previously reported to be present only in Asians. In this study, we determined the distribution of this SNP in normal Southeast Asian populations (Chinese, Malay, Javanese, Thai, Filipino), in South Asian populations (Bangladeshi, Pakistani Pushtun and Indian) and in Chinese retinoblastoma cases and control subjects. The RB1 SNP was present in all populations at an overall frequency of ≤ 0.18. Heterozygosity was higher in the Southeast Asian groups (0.14–0.34) than in the South Asian groups (Bangladeshi and Indian) (0.04–0.06). Significant differences in allele frequencies were found between the two population groups. Interestingly, our Pakistani population comprised of ethnic Pushtuns from northwest Pakistan was significantly different from the neighbouring Bangladeshi and Indian populations. No significant difference was found between Chinese case patients and control subjects. This RB1 SNP appears to be an ethnic variant prevalent in Southeast Asian populations and may be useful for studying RB1 inheritance by pedigree analysis.

  2. An abnormal phenomenon in the saturated absorption spectrum of 87Rb

    Institute of Scientific and Technical Information of China (English)

    贺凌翔; 王育竹

    2003-01-01

    A polarization-type saturated absorption spectrum set-up for 87Rb atom laser cooling and trapping has been established in our laboratory. By changing the polarization components and optical power, enhanced absorption of the transition 5S1/2 F=2 → 5P3/2 F'=3 was observed with other transitions and cross-over resonance staying unvaried.

  3. Electrical transport in RbCl-Al{sub 2}O{sub 3} composite solid electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, A.; Shahi, K. [Indian Inst. of Technology, Kanpur (India). Dept. of Materials Science

    1995-03-01

    The composite solid electrolytes RbCl-{chi} mole percent (m/o) Al{sub 2}O{sub 3} (0 {<=} x {<=} 50) prepared by conventional powder metallurgy and solution casting processes, have been investigated by impedance analysis, x-ray diffraction (XRD), differential thermal analysis (DTA), and scanning electron microscopy (SEM). The composites prepared by the former method exhibit about an order of magnitude lower conductivity than those prepared by the latter technique. The XRD and DT-A results show that no phases other than RbCl and Al{sub 2}O{sub 3}, are present in the composites, SEM results show that RbCl grains are interspersed with Al{sub 2}O{sub 3} particles. The conductivity of dispersed systems depends on the processing, particle size, and concentration of Al{sub 2}O{sub 3}. The mechanism of enhanced conductivity is proposed to be the generation of excess Rb{sup +} for, vacancies in the host matrix at the matrix-particle interface. Macroscopically the results are explained satisfactorily on the basis of random resistor network model by assuming the formation of high conducting space charge layer along the matrix-particle interface.

  4. RB-ARD: A proof of concept rule-based abort

    Science.gov (United States)

    Smith, Richard; Marinuzzi, John

    1987-01-01

    The Abort Region Determinator (ARD) is a console program in the space shuttle mission control center. During shuttle ascent, the Flight Dynamics Officer (FDO) uses the ARD to determine the possible abort modes and make abort calls for the crew. The goal of the Rule-based Abort region Determinator (RB/ARD) project was to test the concept of providing an onboard ARD for the shuttle or an automated ARD for the mission control center (MCC). A proof of concept rule-based system was developed on a LMI Lambda computer using PICON, a knowdedge-based system shell. Knowdedge derived from documented flight rules and ARD operation procedures was coded in PICON rules. These rules, in conjunction with modules of conventional code, enable the RB-ARD to carry out key parts of the ARD task. Current capabilities of the RB-ARD include: continuous updating of the available abort mode, recognition of a limited number of main engine faults and recommendation of safing actions. Safing actions recommended by the RB-ARD concern the Space Shuttle Main Engine (SSME) limit shutdown system and powerdown of the SSME Ac buses.

  5. A Faraday laser lasing on Rb 1529 nm transition.

    Science.gov (United States)

    Chang, Pengyuan; Peng, Huanfa; Zhang, Shengnan; Chen, Zhangyuan; Luo, Bin; Chen, Jingbiao; Guo, Hong

    2017-08-21

    We present the design and performance characterization of a Faraday laser directly lasing on the Rb 1529 nm transition (Rb, 5P 3/2 - 4D 5/2) with high stability, narrow spectral linewidth and low cost. This system does not need an additional frequency-stabilized pump laser as a prerequisite to preparing Rb atom from 5S to 5P excited state. Just by using a performance-improved electrodeless discharge lamp-based excited-state Faraday anomalous dispersion optical filter (LESFADOF), we realized a heterogeneously Faraday laser with the frequency corresponding to atomic transition, working stably over a range of laser diode (LD) current from 85 mA to 171 mA and the LD temperature from 11 °C to 32 °C, as well as the 24-hour long-term frequency fluctuation range of no more than 600 MHz. Both the laser linewidth and relative intensity noisy (RIN) are measured. The Faraday laser lasing on Rb 1529 nm transition (telecom C-band) can be applied to further research on metrology, microwave photonics and optical communication systems. Besides, since the transitions correspongding to the populated excited-states of alkali atoms within lamp are extraordinarily rich, this scheme can increase the flexibility for choosing proper wavelengths for Faraday laser and greatly expand the coverage of wavelength corresponding to atomic transmission for laser frequency stabilization.

  6. RB4CD12 epitope expression and heparan sulfate disaccharide composition in brain vasculature

    NARCIS (Netherlands)

    Hosono-Fukao, T.; Ohtake-Niimi, S.; Nishitsuji, K.; Hossain, M.M.; Kuppevelt, A.H.M.S.M. van; Michikawa, M.; Uchimura, K.

    2011-01-01

    RB4CD12 is a phage display antibody that recognizes a heparan sulfate (HS) glycosaminoglycan epitope. The epitope structure is proposed to contain a trisulfated disaccharide, [-IdoA(2-OSO(3))-GlcNSO(3) (6-OSO(3))-], which supports HS binding to various macromolecules such as growth factors and cytok

  7. Nonlinear magneto-optical effects in cold atoms of 87Rb

    Institute of Scientific and Technical Information of China (English)

    He Ling-Xiang; Wang Yu-Zhu

    2004-01-01

    With laser-cooled cold 87Rb atoms as a magneto-optical medium, a weak right circularly polarized probe field and frequency modulation technique are used to detect the magnetic distribution of the quadrupole field. A two-peak dispersion-like signal other than that of the usual nonlinear magneto-optical effect mentioned in other papers is obtained.

  8. Neutron-proton multiplets in the odd-odd nucleus 53 37 90Rb

    Science.gov (United States)

    Czerwiński, M.; RzÄ ca-Urban, T.; Urban, W.; BÄ czyk, P.; Sieja, K.; Timár, J.; Nyakó, B. M.; Kuti, I.; Tornyi, T. G.; Atanasova, L.; Blanc, A.; Jentschel, M.; Mutti, P.; Köster, U.; Soldner, T.; de France, G.; Simpson, G. S.; Ur, C. A.

    2016-03-01

    Medium-spin excited levels in 90Rb, populated in the fission of 235U induced by neutrons, have been observed for the first time. γ radiation from fission has been measured by using the EXILL array of Ge detectors at the cold-neutron-beam facility PF1B of the Institut Laue-Langevin, Grenoble. Low-energy levels are interpreted as members of the π p3/2 -1ν (d5/2) 3 , π f5/2 -1ν (d5/2) 3 , and π g9 /2ν (d5/2) 3 multiplets with the 0- ground state due to the seniority-3 coupling in the ν d5 /2 shell. Analogous anomalous coupling within the π g9 /2ν (d5/2) 3 configuration explains the 5+, 6+, and 7+ triplet of states, observed at medium spins, similar to the triplet seen in the N =53 isotone, 88Br. Shell-model calculations reproduce well the proposed structures in Rb,9088 and support the seniority-3 coupling in N =53 isotones and its absence in N =51 isotones. The structure of the odd-odd 88Rb and 90Rb nuclei provides an argument in favor of the collectivity building up at the neutron number N =53 .

  9. pRB binds to and modulates the transrepressing activity of the E1A-regulated transcription factor p120E4F

    NARCIS (Netherlands)

    Fajas, L.; Paul, C.; Zugasti, O.; Cam, L. Le; Polanowska, J.; Fabbrizio, E.; Medema, R.H.; Vignais, M.-L.; Sardet, C.

    2000-01-01

    The retinoblastoma protein pRB is involved in the transcriptional control of genes essential for cell cycle progression and differentiation. pRB interacts with different transcription factors and thereby modulates their activity by sequestration, corepression, or activation. We report that pRB, but

  10. Deletion of autophagy inducer RB1CC1 results in degeneration of the retinal pigment epithelium.

    Science.gov (United States)

    Yao, Jingyu; Jia, Lin; Khan, Naheed; Lin, Chengmao; Mitter, Sayak K; Boulton, Michael E; Dunaief, Joshua L; Klionsky, Daniel J; Guan, Jun-Lin; Thompson, Debra A; Zacks, David N

    2015-01-01

    Autophagy regulates cellular homeostasis and response to environmental stress. Within the retinal pigment epithelium (RPE) of the eye, the level of autophagy can change with both age and disease. The purpose of this study is to determine the relationship between reduced autophagy and age-related degeneration of the RPE. The gene encoding RB1CC1/FIP200 (RB1-inducible coiled-coil 1), a protein essential for induction of autophagy, was selectively knocked out in the RPE by crossing Best1-Cre mice with mice in which the Rb1cc1 gene was flanked with Lox-P sites (Rb1cc1(flox/flox)). Ex vivo and in vivo analyses, including western blot, immunohistochemistry, transmission electron microscopy, fundus photography, optical coherence tomography, fluorescein angiography, and electroretinography were performed to assess the structure and function of the retina as a function of age. Deletion of Rb1cc1 resulted in multiple autophagy defects within the RPE including decreased conversion of LC3-I to LC3-II, accumulation of autophagy-targeted precursors, and increased numbers of mitochondria. Age-dependent degeneration of the RPE occurred, with formation of atrophic patches, subretinal migration of activated microglial cells, subRPE deposition of inflammatory and oxidatively damaged proteins, subretinal drusenoid deposits, and occasional foci of choroidal neovascularization. There was secondary loss of photoreceptors overlying the degenerated RPE and reduction in the electroretinogram. These observations are consistent with a critical role of autophagy in the maintenance of normal homeostasis in the aging RPE, and indicate that disruption of autophagy leads to retinal phenotypes associated with age-related degeneration.

  11. The significant effect of heterojunction quality on photoelectrochemical water splitting in bilayer photoelectrodes: Rb(x)WO3 thin films on RbLaNb2O7 layers.

    Science.gov (United States)

    Nakajima, Tomohiko; Nakamura, Takako; Tsuchiya, Tetsuo

    2014-12-28

    We have prepared nearly perfect hexagonal m-plane-oriented RbxWO3 films on (010)-oriented RbLaNb2O7 layers. The prepared bilayer films showed Rb diffusion from the RbLaNb2O7 seed layers, and we obtained uniaxially oriented RbxWO3/Rb1-yLaNb2O7 photoanodes. The RbxWO3/Rb1-yLaNb2O7 bilayer photoanodes exhibited enhanced photoelectrochemical water splitting compared with the RbxWO3 and RbLaNb2O7 monolayer photoanodes. Furthermore, we clearly demonstrated that the high crystal quality of the heterojunction significantly enhanced water splitting. The photocurrent density of the nearly perfectly oriented RbxWO3/Rb1-yLaNb2O7 photoanode that we prepared was 9.4-fold that of an unoriented bilayer photoanode. This increase was attributed to the inhibition of photo-excited charge recombination and stimulated electron transfer derived from low grain-boundary resistance.

  12. Ginsenoside-Rb1 Protects Hypoxic- and Ischemic-Damaged Cardiomyocytes by Regulating Expression of miRNAs

    Directory of Open Access Journals (Sweden)

    Xu Yan

    2015-01-01

    Full Text Available Ginsenoside (GS-Rb1 is one of the most important active compounds of ginseng, with extensive evidence of its cardioprotective properties. However, the miRNA mediated mechanism of GS-Rb1 on cardiomyocytes remains unclear. Here, the roles of miRNAs in cardioprotective activity of GS-Rb1 were investigated in hypoxic- and ischemic-damaged cardiomyocytes. Neonatal rat cardiomyocytes (NRCMs were first isolated, cultured, and then incubated with or without GS-Rb1 (2.5–40 μM in vitro under conditions of hypoxia and ischemia. Cell growth, proliferation, and apoptosis were detected by MTT and flow cytometry. Expressions of various microRNAs were analyzed by real-time PCR. Compared with that of the control group, GS-Rb1 significantly decreased cell death in a dose-dependent manner and expressions of mir-1, mir-29a, and mir-208 obviously increased in the experimental model groups. In contrast, expressions of mir-21 and mir-320 were significantly downregulated and GS-Rb1 could reverse the differences in a certain extent. The miRNAs might be involved in the protective effect of GS-Rb1 on the hypoxia/ischemia injuries in cardiomyocytes. The effect might be based on the upregulation of mir-1, mir-29a, and mir-208 and downregulation of mir-21 and mir-320. This might provide us a new target to explore the novel strategy for ischemic cardioprotection.

  13. Interspecies collision-induced losses in a dual species 7Li-85Rb magneto-optical trap

    Science.gov (United States)

    Dutta, Sourav; Altaf, Adeel; Lorenz, John; Elliott, D. S.; Chen, Yong P.

    2014-05-01

    In this article, we report the measurement of collision-induced loss rate coefficients βLi, Rb and βRb, Li, and also discuss means to significantly suppress such collision-induced losses. We first describe our dual-species magneto-optical trap (MOT) that allows us to simultaneously trap ≥5 × 108 7Li atoms loaded from a Zeeman slower and ≥2 × 108 85Rb atoms loaded from a dispenser. We observe strong interspecies collision-induced losses in the MOTs which dramatically reduce the maximum atom number achievable in the MOTs. We measure the trap loss rate coefficients βLi, Rb and βRb, Li, and, from a study of their dependence on the MOT parameters, determine the cause for the losses observed. Our results provide valuable insights into ultracold collisions between 7Li and 85Rb, guide our efforts to suppress collision-induced losses, and also pave the way for the production of ultracold 7Li85Rb molecules.

  14. Interspecies collision-induced losses in a dual species 7Li-85Rb magneto-optical trap

    CERN Document Server

    Dutta, Sourav; Lorenz, John; Elliott, D S; Chen, Yong P

    2013-01-01

    In this article, we report the measurement of collision-induced loss coefficients \\beta_{Li,Rb} and \\beta_{Rb,Li}, and also discuss means to significantly suppress such collision induced losses. We first describe our dual-species magneto-optical trap (MOT) that allows us to simultaneously trap > 5x10^8 7Li atoms loaded from a Zeeman slower and > 2x10^8 85Rb atoms loaded from a dispenser. We observe strong interspecies collision-induced losses in the MOTs which dramatically reduce the maximum atom number achievable in the MOTs. We measure the trap loss rate coefficients \\beta_{Li,Rb} and \\beta_{Rb,Li}, and, from a study of their dependence on the MOT parameters, determine the cause for the losses observed. Our results provide valuable insights into ultracold collisions between 7Li and 85Rb, guide our efforts to suppress collision induced losses, and also pave the way for the production of ultracold 7Li85Rb molecules.

  15. Cell cycle-dependent phosphorylation of pRb-like protein in root meristem cells of Vicia faba.

    Science.gov (United States)

    Polit, Justyna Teresa; Kaźmierczak, Andrzej; Walczak-Drzewiecka, Aurelia

    2012-01-01

    The retinoblastoma tumor suppressor protein (pRb) regulates cell cycle progression by controlling the G1-to-S phase transition. As evidenced in mammals, pRb has three functionally distinct binding domains and interacts with a number of proteins including the E2F family of transcription factors, proteins with a conserved LxCxE motif (D-type cyclin), and c-Abl tyrosine kinase. CDK-mediated phosphorylation of pRb inhibits its ability to bind target proteins, thus enabling further progression of the cell cycle. As yet, the roles of pRb and pRb-binding factors have not been well characterized in plants. By using antibody which specifically recognizes phosphorylated serines (S807/811) in the c-Abl tyrosine kinase binding C-domain of human pRb, we provide evidence for the cell cycle-dependent changes in pRb-like proteins in root meristems cells of Vicia faba. An increased phosphorylation of this protein has been found correlated with the G1-to-S phase transition.

  16. Precision-controlled elution of a 82Sr/82Rb generator for cardiac perfusion imaging with positron emission tomography

    Science.gov (United States)

    Klein, R.; Adler, A.; Beanlands, R. S.; de Kemp, R. A.

    2007-02-01

    A rubidium-82 (82Rb) elution system is described for use with positron emission tomography. Due to the short half-life of 82Rb (76 s), the system physics must be modelled precisely to account for transport delay and the associated activity decay and dispersion. Saline flow is switched between a 82Sr/82Rb generator and a bypass line to achieve a constant-activity elution of 82Rb. Pulse width modulation (PWM) of a solenoid valve is compared to simple threshold control as a means to simulate a proportional valve. A predictive-corrective control (PCC) algorithm is developed which produces a constant-activity elution within the constraints of long feedback delay and short elution time. The system model parameters are adjusted through a self-tuning algorithm to minimize error versus the requested time-activity profile. The system is self-calibrating with 2.5% repeatability, independent of generator activity and elution flow rate. Accurate 30 s constant-activity elutions of 10-70% of the total generator activity are achieved using both control methods. The combined PWM-PCC method provides significant improvement in precision and accuracy of the requested elution profiles. The 82Rb elution system produces accurate and reproducible constant-activity elution profiles of 82Rb activity, independent of parent 82Sr activity in the generator. More reproducible elution profiles may improve the quality of clinical and research PET perfusion studies using 82Rb.

  17. Synthesis and tunable luminescence of RbCaGd(PO4)2:Ce3+, Mn2+ phosphors

    Science.gov (United States)

    Chen, Xue; Lv, Fengzhu; Li, Penggang; Zhang, Yihe

    2016-04-01

    RbCaGd(PO4)2 doped with Ce3+, Mn2+ was synthesized by the sol-gel method. The crystal structure and crystallographic location of Ce3+ in RbCaGd(PO4)2 were identified by Rietveld refinement. Powder X-ray diffraction (XRD) revealed that the structure of RbCaGd(PO4)2:Ce3+ compounds is hexagonal structure which is similar to that of hexagonal LnPO4 with the lattice constant of a = b = 7.005(57) Å, c = 6.352(05) Å, and V (cell volume) = 269.980 Å3. The photoluminescence behavior and emission mechanism were studied systematically by doping activators in the RbCaGd(PO4)2 host. The Mn2+ incorporated RbCaGd(PO4)2:Ce3+, Mn2+ compounds exhibited blue emission from the parity- and spin-allowed f-d transition of Ce3+ and orange-to-red emission from the forbidden 4T1 → 6A1 transition of Mn2+. The emission chromaticity coordinates of RbCaGd(PO4)2:0.10Ce3+, xMn2+ (x = 0.16, 0.25) are close to the white region due to an energy transfer process and the energy transfer mechanism from Ce3+ to Mn2+ in the RbCaGd(PO4)2 host was dominated by dipole-dipole interactions.

  18. Effects of shRNA Targeting Survivin on Apoptosis of Human Retinoblastoma Cell Line Hxo-rb44 in vitro

    Institute of Scientific and Technical Information of China (English)

    WANG Guojun; HU Yanhua; LI Pengcheng

    2006-01-01

    In order to construct a recombinant plasmid containing short hairpin RNA (shRNA) targeting survivin and to investigate its effect on survivin expression and cell apoptosis of human retinoblastoma cell line Hxo-rb44 in vitro, RNA interference plasmid pSIRENS that can express shRNA of survivin was designed, constructed, and transfected into human retinoblastoma cell line Hxo-rb44.Survivin and c-Myc expression was detected by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Apoptosis of Hxo-rb44 cells was assayed by Honchest33258 staining and cell growth curve was drawn. The results showed that the oligonucleotide targeting survivin was identified in pSIRENS plasmid. After pSIRENS plasmid transfected, survivin and c-Myc expression in Hxo-rb44 cells was decreased significantly. Apoptotic rate of cells was up-regulated from (3.5±1.29) % to (36.1±19.66) %. The proliferation ability of Hxo-rb44 cells was inhibited. No significant effects on survivin expression and apoptosis of the cells were found when negative control plasmid was transfected. In conclusion, the plasmid containing shRNA targeting survivin was constructed successfully. It could inhibit efficiently the expression of survivin and c-Myc in human retinoblastoma cell Hxo-rb44 in vitro. The inhibition of the expression of c-Myc might be involved in the apoptosis of Hxo-rb44 cells.

  19. Effects of exogenous recombinant bovine somatotropin (rbST on hematological indices of Kundhi buffalo male calves.

    Directory of Open Access Journals (Sweden)

    Khuhro AP

    2016-06-01

    Full Text Available The aim of present research was assessment of the rbST effects on hematological indices and also its optimum safe dose in kundhi buffalo male calves for beef production. The calves were divided into three groups, with or without rbST treatment. The rbST administered intramuscularly during fortnight, for eleven weeks with an interval of two weeks. Then blood samples were collected at the end of eleven weeks for analysis. In comparison with group A and B, red blood cells count, hemoglobin, mean corpuscular hemoglobin concentration, platelets count and mean corpuscular volume indices were significantly (P<0.05 higher. There was no significant effect on mean corpuscular hemoglobin, erythrocyte sedimentation rate and packed cell volume. The white blood cells in rbST treated groups (P<0.05 increased, and this increase was attributed due to increase in neutrophil number. However, there was non-significant effect of rbST on eosinophils, basophils, monocytes and lymphocytes between all groups. It was concluded from outcomes that rbST produced dose dependent effect on hematological values in kundi buffaloe calves and no adversely higher values were observed that determine polycethemia or leukocytosis. It is therefore suggested that rbST can be used at the dose rate of 1mg/kg b.w. as growth promoter in Kundhi buffaloe calves.

  20. Electronic parameters and top surface chemical stability of RbPb{sub 2}Br{sub 5}

    Energy Technology Data Exchange (ETDEWEB)

    Atuchin, V.V., E-mail: atuchin@thermo.isp.nsc.ru [Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk 90, 630090 (Russian Federation); Isaenko, L.I. [Laboratory of Crystal Growth, Institute of Geology and Mineralogy, SB RAS, Novosibirsk 90, 630090 (Russian Federation); Kesler, V.G. [Laboratory of Physical Principles for Integrated Microelectronics, Institute of Semiconductor Physics, SB RAS, Novosibirsk 90, 630090 (Russian Federation); Pokrovsky, L.D. [Laboratory of Optical Materials and Structures, Institute of Semiconductor Physics, SB RAS, Novosibirsk 90, 630090 (Russian Federation); Tarasova, A.Yu. [Laboratory of Crystal Growth, Institute of Geology and Mineralogy, SB RAS, Novosibirsk 90, 630090 (Russian Federation)

    2012-01-16

    Highlights: Black-Right-Pointing-Pointer Bridgman growth of RbPb{sub 2}Br{sub 5} crystal. Black-Right-Pointing-Pointer Electronic structure measurements with XPS. Black-Right-Pointing-Pointer Optical crystalline surface fabrication. - Abstract: The RbPb{sub 2}Br{sub 5} crystal has been grown by Bridgman method. The electronic structure of RbPb{sub 2}Br{sub 5} has been measured with XPS for a powder sample. High chemical stability of RbPb{sub 2}Br{sub 5} surface is verified by weak intensity of O 1s core level recorded by XPS and structural RHEED measurements. Chemical bonding effects have been observed by the comparative analysis of element core levels and crystal structure of RbPb{sub 2}Br{sub 5} and several rubidium- and lead-containing bromides using binding energy difference parameters {Delta}{sub Rb} = (BE Rb 3d - BE Br 3d) and {Delta}{sub Pb} = (BE Pb 4f{sub 7/2} - BE Br 3d).

  1. Investigation of an unusual low-temperature phase transformation in RbBH{sub 4} by neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Kitchen, Brian B. [Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Verdal, Nina, E-mail: nina.verdal@nist.gov [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102 (United States); Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742-2115 (United States); Udovic, Terrence J. [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102 (United States); Rush, John J. [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102 (United States); Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742-2115 (United States); Hartman, Michael R. [Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); DeVries, Daniel J. [Radiation and Isotopes for Health, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands)

    2013-07-15

    To investigate the previously reported low-temperature phase transition in rubidium borohydride (RbBH{sub 4}) near 48.5 K, we carried out neutron powder diffraction and vibrational spectroscopy measurements both above and below this temperature on an isotopically-enriched sample of Rb{sup 11}BD{sub 4}. Our diffraction data reflected an average cubic Fm3{sup ¯}m structure with BD{sub 4}{sup −} anion orientational disorder at all temperatures, with no hint of extra Bragg peaks due to long-range orientational order below the transition temperature as reported by others. These structural results and careful analysis of torsional vibrations in RbBD{sub 4} corroborate the results of prior neutron vibrational spectroscopy measurements suggesting that the low-temperature RbBH{sub 4} structure indeed possesses some orientational ordering of the BH{sub 4}{sup −} anions, but of a shorter-ranged nature insensitive to powder diffraction methods. - The neutron powder diffraction pattern of RbBD{sub 4} below the phase transition temperature (shown here in black) is indistinguishable from that collected above the phase transition temperature. The inset depicts the cubic structure that fits the data at both temperatures. - Highlights: • We investigated the nature of the RbBD{sub 4} phase transition using NVS and NPD. • A change in shape of the RbBD{sub 4} torsion mode was observed across the transition. • The RbBD{sub 4} diffraction pattern across this phase transition was unchanged. • The phase transition in RbBD{sub 4} appears to produce only short-range ordering of BD{sub 4}{sup −}.

  2. EXPRESSION AND FUNCTIONAL INTERACTION OF CHICKEN RbAp46 POLYPEPTIDE WITH HISTONES, HISTONE DEACETYLASE-1, AND HISTONE ACETYLTRANSFERASE-1

    Directory of Open Access Journals (Sweden)

    Ahyar Ahmad

    2013-08-01

    Full Text Available In this study, we cloned and sequenced cDNA encoding the chicken p46 polypeptide, RbAp46. The cDNA encoding a protein consists of 424 amino acids is a member of the WD protein family, with seven WD repeat motifs, and exhibits 90.3% identity to RbAp48, and 94.3% identity to the human RbAp46. The RbAp46 fusion protein were synthesized by in vitro translation system and in Escherichia coli under induction by 50 µM IPTG and single step purified with glutathione-Agarose beads, showed that GST-tagged protein of approximately 72 kDa. The in vitro experiment established that RbAp46 interacts with chicken histones, chHDAC-1, and chHAT-1. The in vitro immunoprecipitation experiment, involving truncated mutants of RbAp46, revealed not only that two regions comprising amino acids 33-179 and 375-404 are necessary for its binding to H2B, but also that two regions comprising amino acids 1-32 and 405-424 are necessary for its binding to H4. Furthermore, the GST pulldown affinity assay, involving truncated mutants of RbAp46, revealed that a region comprising amino acids 359-404 binds to chHAT-1 in vitro. Taken together, these results indicate not only that RbAp46 should participate differentially in a number of DNA-utilizing processes through interactions of its distinct regions with histones and chHAT-1, but also that the proper propeller structure of RbAp46 is not necessary for its interaction with chHAT-1.

  3. Study of polymorphisms in the TP53 and RB1 genes in children with retinoblastoma in northern Mexico

    Science.gov (United States)

    Nares-Cisneros, Jesús; Cárdenas-Hernández, Rubén I.; Jaramillo-Rodríguez, Yolanda; Zambrano-Galván, Graciela

    2017-01-01

    Purpose To determine the frequency and association of polymorphisms in the TP53 and RB1 genes with clinical characteristics in a group of children with retinoblastoma (RB) in northern Mexico. Methods A prospective, longitudinal, and analytical study of 11 patients diagnosed with RB was conducted. Endpoint PCR and high-resolution real-time PCR were performed. Chi-square and Student t tests were used to evaluate associations between variables. Allelic frequencies, as well as genotypic and Hardy–Weinberg equilibriums, were evaluated using Guo and Thompson’s method. Results We found a statistically significant difference between the polymorphism RB1-GG/rs9568036 and tumor chemoresistance (p<0.05). The allelic variants RB1-AA and AG/rs9568036 were determined to be associated with tumor chemosensitivity (p<0.05). A statistically significant relation between the polymorphism RB1-GG/rs9568036 and males (p = 0.0386), rate ratio (RR) = 2.0 (95% confidence interval [CI] = 0.76–5.32), as well as between the allelic variants RB1-AA and AG/rs9568036 and females (p = 0.0027), RR = 8.0 (95% CI = 1.28–50.04), was observed. We also observed a statistically significant association between the rs1042522 polymorphism in the TP53 gene and unilateral presentation of the disease. Conclusions The rs9568036 polymorphism in the RB1 gene and the allelic variants can be associated with type of response to medical therapy and associated with male sex, while the allelic variant rs1042522 polymorphism in the TP53 gene is associated with the unilateral presentation of the disease in a group of Mexican children with RB. PMID:28210099

  4. Metal-insulator transition in AC{sub 60}:RbC{sub 60} and KC{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Khazeni, K.; Crespi, V.H.; Hone, J.; Zettl, A.; Cohen, M.L. [Department of Physics, University of California at Berkeley, Berkeley, California 94720 (United States)]|[Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)

    1997-09-01

    At zero pressure polymerized RbC{sub 60} is an insulator, whereas polymerized KC{sub 60} is a metal with a slight low-temperature resistive upturn. We report measurements of the resistivity of RbC{sub 60} under pressure, finding a hysteretic resistive transition in RbC{sub 60} near 200 K at 5 kbar, at which point the material transforms from insulator to metal. Correcting the resistivity to constant volume, both materials are metallic below the transition with a common low-temperature resistive upturn which is suppressed under compression. {copyright} {ital 1997} {ital The American Physical Society}

  5. Direct estimation of the recombination frequency between the RB1 gene and two closely linked microsatellites using sperm typing.

    Science.gov (United States)

    Girardet, A; Lien, S; Leeflang, E P; Beaufrère, L; Tuffery, S; Munier, F; Arnheim, N; Claustres, M; Pellestor, F

    1999-01-01

    In this study, single sperm typing has been used for high-resolution recombination analysis between the retinoblastoma gene and two closely linked extragenic microsatellites (D13S284 and D13S1307). The analysis of 1198 single sperm from three donors allowed the determination of recombination fractions between RB1.20 and D13S284 and RB1.20 and D13S1307 of 0.022 and 0.033, respectively. These results show that RB1 gene and the two microsatellites are closely linked, which validates their potential use in indirect genetic diagnosis of retinoblastoma.

  6. Development of an optically pumped atomic magnetometer using a K-Rb hybrid cell and its application to magnetocardiography

    Directory of Open Access Journals (Sweden)

    Yosuke Ito

    2012-09-01

    Full Text Available We have developed an optically pumped atomic magnetometer using a hybrid cell of K and Rb. The hybrid optical pumping technique can apply dense alkali-metal vapor to the sensor head and leads to high signal intensity. We use dense Rb vapor as probed atoms, and achieve a sensitivity of approximately 100 fTrms/Hz1/2 around 10 Hz. In this case, the sensitivity is limited by the system noise, and the magnetic linewidth is narrower than that for direct Rb optical pumping. We demonstrated magnetocardiography using the magnetometer and obtained clear human magnetocardiograms.

  7. EXPRESSION OF p16, CYCLIN D1 AND RB PROTEIN IN GASTRIC CARCINOMA AND PREMALIGNANT LESIONS

    Institute of Scientific and Technical Information of China (English)

    缪林; 赵志泉; 季国忠; 范志宁; 金宁; 刘政; 张平; 程铁华

    2003-01-01

    Objective: To investigate the expression of p16, cyclin D1 and Rb protein in gastric carcinoma and premalignant lesions including dysplastic gastric mucosa and intestinal metaplasia gastric mucosa. Methods: Using SP immunohistochemical methods, the expression of pl6, cyclin D1 and Rb proteins was detected in 10 specimens of normal gastric mucosa, 15 specimens of dysplastic gastric mucosa, 15 specimens of intestinal metaplasia gastric mucosa, 30 specimens of gastric carcinoma. The clinical characteristics of the 30 patients with gastric carcinoma were analysed to explore the relationship between the parameter detected and biological action of gastric cancer. Results: Expression of p16 protein was detected in 90% of normal gastric mucosa, 86.67% of dysplastic gastric mucosa, 86.67% of intestinal metaplasia gastric mucosa, 36.67% of gastric carcinoma. The positive rate of p16 protein expression in gastric carcinoma is significantly lower than that in normal gastric mucosa and gastric premalignant lesions mucosa (P<0.01). Expression of cyclin D1 protein was detected in 10% of normal gastric mucosa, 20% of dysplastic gastric mucosa, 20% of intestinal metaplasia gastric mucosa, 53.33% of gastric carcinoma. The positive rate of cyclin D1, protein expression in gastric carcinoma is significantly higher than that in normal gastric mucosa and gastric premalignant lesions mucosa (P<0.05). Expression of Rb protein was detected in 90% of normal gastric mucosa, 80% of dysplastic gastric mucosa, 80% of intestinal metaplasia gastric mucosa, 50% of gastric carcinoma. The positive rate of Rb protein expression in gastric carcinoma is significantly lower than that in normal gastric mucosa (P<0.05). The expression of p16, cyclin D1 gene were associated with the degree of differentiation of gastric carcinoma, lymphnodes metastasis and distant metastasis. Conclusion: p16, Cyclin D1 and Rb gene play important role in gastric carcinoma genesis. The expression of p16, cyclin D1 and Rb gene

  8. Le nitrate double NaRb2(NO33, composé intermédiaire du système binaire isobare NaNO3 + RbNO3: études thermiques et cristallographiques

    Directory of Open Access Journals (Sweden)

    Nesrine Ksiksi

    2015-05-01

    Full Text Available Crystallographic and thermodynamic investigations of the binary (NaNO3 + RbNO3 phase diagram at atmospheric pressure reveal the existence of an intermediate compound NaRb2(NO33 (sodium dirubidium trinitrate previously predicted and now reported experimentally for the first time. According to a DSC analysis, the compound exhibits three allotropic forms. In its low-temperature allotropic form (α form, orthorhombic there are two Rb (m.. site symmetry and one Na (m.. independent crystallographic positions and three planar nitrate groups. The bond-valence-sum calculations for all atoms agree well with their oxidation states. The Rb cations are located in the (100 plane at x = ½ with 11 oxygen coordination. The Na ones are in the same plane at x = 0 and are coordinated to eight O atoms from six nitrate groups. The charge-distribution method has been used to evaluate the degree of distortion of the alkali polyhedra.

  9. Detection of microvascular and tri-truncal coronaries injuries by quantitative cardiac PET/CT with Rb-82;Detection des lesions coronaires microvasculaires et tritronculaires par TEP-CT cardiaque quantitative au Rb-82

    Energy Technology Data Exchange (ETDEWEB)

    Dunet, V.; Allenbach, G.; Soubeyran, V.; Kosinski, M.; Bischof-Delaloye, A.; Prior, J. [CHU de Vaudois, Departement de medecine nucleaire, Lausanne (Switzerland); Camus, F. [CHU de Vaudois, institut de radiophysique appliquee, Lausanne (Switzerland)

    2010-05-15

    The results show that up to 1 in 5 investigated by PET / CT with Rb-82 with myocardium blood rate quantification shows affected myocardium flux reserve linked to microvascular or tri-truncal affect undiagnosed by semi-quantitative analysis

  10. The extreme COOH terminus of the retinoblastoma tumor suppressor protein pRb is required for phosphorylation on Thr-373 and activation of E2F.

    Science.gov (United States)

    Gorges, Laura L; Lents, Nathan H; Baldassare, Joseph J

    2008-11-01

    The retinoblastoma protein pRb plays a pivotal role in G(1)- to S-phase cell cycle progression and is among the most frequently mutated gene products in human cancer. Although much focus has been placed on understanding how the A/B pocket and COOH-terminal domain of pRb cooperate to relieve transcriptional repression of E2F-responsive genes, comparatively little emphasis has been placed on the function of the NH(2)-terminal region of pRb and the interaction of the multiple domains of pRb in the full-length context. Using "reverse mutational analysis" of Rb(DeltaCDK) (a dominantly active repressive allele of Rb), we have previously shown that restoration of Thr-373 is sufficient to render Rb(DeltaCDK) sensitive to inactivation via cyclin-CDK phosphorylation. This suggests that the NH(2)-terminal region plays a more critical role in pRb regulation than previously thought. In the present study, we have expanded this analysis to include additional residues in the NH(2)-terminal region of pRb and further establish that the mechanism of pRb inactivation by Thr-373 phosphorylation is through the dissociation of E2F. Most surprisingly, we further have found that removal of the COOH-terminal domain of either RbDeltaCDK(+T373) or wild-type pRb yields a functional allele that cannot be inactivated by phosphorylation and is repressive of E2F activation and S-phase entry. Our data demonstrate a novel function for the NH(2)-terminal domain of pRb and the necessity for cooperation of multiple domains for proper pRb regulation.

  11. Formation of deeply bound ultracold LiRb molecules via photoassociation near the Li 2 S1 /2+Rb 5 P3 /2 asymptote

    Science.gov (United States)

    Lorenz, John; Altaf, Adeel; Dutta, Sourav; Chen, Yong P.; Elliott, D. S.

    2014-12-01

    We present spectra of ultracold 7Li85Rb molecules in their electronic ground state formed by spontaneous decay of weakly bound photoassociated molecules. Beginning with atoms in a dual-species magneto-optical trap, weakly bound molecules are formed in the 4(1) electronic state, which corresponds to the B1Π state at short range. These molecules spontaneously decay to the electronic ground state and we use resonantly enhanced multiphoton ionization to determine the vibrational population distribution in the electronic ground states after spontaneous emission. Many of the observed lines from the spectra are consistent with transitions from the X1Σ+ ground electronic state to either the B1Π or the D1Π electronic state that has been previously observed, with levels possibly as low as X1Σ+ (v''=2 ) being populated. We do not observe decay to weakly bound vibrational levels of the X1Σ+ or a3Σ+ electronic state in the spectra. We also deduce a lower bound of 3900 cm -1 for the dissociation energy of the LiRb + molecular ion.

  12. Desorption Dynamics of Heavy Alkali Metal Atoms (Rb, Cs) off the Surface of Helium Nanodroplets

    CERN Document Server

    von Vangerow, J; Stienkemeier, F; Mudrich, M; Leal, A; Mateo, D; Hernando, A; Barranco, M; Pi, M

    2014-01-01

    We present a combined ion imaging and density functional theory study of the dynamics of the desorption process of rubidium and cesium atoms off the surface of helium nanodroplets upon excitation of the perturbed $6s$ and $7s$ states, respectively. Both experimental and theoretical results are well represented by the pseudodiatomic model for effective masses of the helium droplet in the desorption reaction of m_eff/m_He~10 (Rb) and 13 (Cs). Deviations from this model are found for Rb excited to the 6p state. Photoelectron spectra indicate that the dopant-droplet interaction induces relaxation into low-lying electronic states of the desorbed atoms in the course of the ejection process.

  13. Observation of Quantum Beat in Rb by Parametric Four-Wave Mixing

    Institute of Scientific and Technical Information of China (English)

    ZHU Chang-Jun; HE Jun-Fang; XUE Bing; ZHAI Xue-Jun

    2007-01-01

    @@ Two coupled parametric four-wave-mixing processes in Rb atoms are studied using perturbation theory, which reveals clear evidence of the appearance of quantum beat at 608cm-1, corresponding to the energy difference of the 7s - 5d states of Rb atoms, in the parametric four-wave-mixing signals. A pump-probe technique is utilized to observe the quantum beat. Time-varying characteristics of the quantum beat are investigated using time-dependent Fourier transform. The results show that the time-varying characteristics of the quantum beat not only offers a sensitive detecting method for observing the decay of atomic wave packets, but also provides a potential tool for monitoring the dissociation of molecules.

  14. The superconducting phase and electronic excitations of (Rb,Cs) Fe 2 As 2

    Science.gov (United States)

    Kanter, J.; Shermadini, Z.; Khasanov, R.; Amato, A.; Bukowski, Z.; Batlogg, B.

    2011-03-01

    We present specific heat, transport and Muon-Spin Rotation (μ SR) results on (Rb,Cs) Fe 2 As 2 . RbFe 2 As 2 was only recently found to be superconducting below 2.6 K by Bukowski et al. Compared to the related BaFe 2 As 2 the electron density is lower and no magnetic order is observed. For the superconducting phase the superfluid density was calculated from μ SR data. The temperature dependence of the superfluid density and the magnetic penetration depth is well described by a multi-gap scenario. In addition the electronic contribution the specific heat was studied for different compositions and magnetic fields and reveals a high value for the Sommerfeld coefficient γ .

  15. Collisions of trapped ions with ultracold atoms in the [YbRb]$^+$ system

    CERN Document Server

    Lamb, H D L; Goold, J; Wells, N; Lane, I

    2011-01-01

    We investigate the ultracold elastic scattering for the quasi-molecular ion of ytterbium and rubidium system, based on {\\it ab initio} calculations, including both asymptotic ionic channels. This structure has an important role in the design of hybrid ion-atom traps and quantum control of charge transfer processes. The dissociation energies and molecular constants for the lowest electronic states were calculated along with the long-range dispersion forces in order to estimate the scattering lengths. The separated-atom ionization potentials and atomic polarizability of the ytterbium atom ($\\alpha_d=128.5$ atomic units) are in good agreement with experiment and previous calculations. Using phase shift analysis and the semiclassical approximation, for the Rb$^+$ channel the scattering length is $a_s \\approx +2815\\ a_{0}$. With the Yb$^+$ ion colliding with the Rb atom we have the complications of singlet/triplet and the presence of nearly-degenerate charge transfer states introducing uncertainty. For the triplet...

  16. Noninvasive Quantification of Tumor Blood Flow in Prostate Cancer using 82Rb PET/CT

    DEFF Research Database (Denmark)

    Tolbod, Lars Poulsen; Nielsen, Maria Munk; Harms, Hans

    drawn on MRI images coregistered to the PET series. TBF was calculated using BSIF or IDIF data from either the aorta, as obtained from the separate heart scan, or the iliac arteries. Results: Automatic extraction of IDIFs derived fromthe aorta/left ventricle (heart scans) and the iliac arteries (pelvis......, logistically challenging and requires an on-site cyclotron. We investigated the accuracy of simplified TBF measurements using with image derived input functions (IDIF) with 15O-H2O and the more widely accessible tracer 82Rb. Method: 9 patients with prostate cancer were included. Dynamic PET scans of the heart...... blood flow was also seen in the transition zone, most likely due to benign prostatic hyperplasia. Conclusion: Both 15O-H2O and 82Rb can be used for quantitative imaging of tumor blood flow in prostate cancer without catheter-based arterial blood sampling. Full pharmacokinetic analysis can be performed...

  17. Electronic structure of β-RbNd(MoO4)2 by XPS and XES

    Science.gov (United States)

    Atuchin, V. V.; Khyzhun, O. Y.; Chimitova, O. D.; Molokeev, M. S.; Gavrilova, T. A.; Bazarov, B. G.; Bazarova, J. G.

    2015-02-01

    β-RbNd(MoO4)2 microplates have been prepared by the multistage solid state synthesis method. The phase composition and micromorphology of the final product have been evaluated by XRD and SEM methods. The electronic structure of β-RbNd(MoO4)2 molybdate has been studied employing the X-ray photoelectron spectroscopy (XPS) and X-ray emission spectroscopy (XES). For the molybdate, the XPS core-level and valence-band spectra, as well as XES bands representing energy distribution of the Mo 4d- and O 2p-like states, have been measured. It has been established that the O 2p-like states contribute mainly to the upper portion of the valence band with also significant contributions throughout the whole valence-band region. The Mo 4D-like states contribute mainly to a lower valence band portion.

  18. High-Spatial-Resolution Monitoring of Strong Magnetic Field using Rb vapor Nanometric-Thin Cell

    CERN Document Server

    Hakhumyan, G; Pashayan-Leroy, Y; Sarkisyan, D; Auzinsh, M

    2011-01-01

    We have implemented the so-called $\\lambda$-Zeeman technique (LZT) to investigate individual hyperfine transitions between Zeeman sublevels of the Rb atoms in a strong external magnetic field $B$ in the range of $2500 - 5000$ G (recently it was established that LZT is very convenient for the range of $10 - 2500$ G). Atoms are confined in a nanometric thin cell (NTC) with the thickness $L = \\lambda$, where $\\lambda$ is the resonant wavelength 794 nm for Rb $D_1$ line. Narrow velocity selective optical pumping (VSOP) resonances in the transmission spectrum of the NTC are split into several components in a magnetic field with the frequency positions and transition probabilities depending on the $B$-field. Possible applications are described, such as magnetometers with nanometric local spatial resolution and tunable atomic frequency references.

  19. High-spatial-resolution monitoring of strong magnetic field using Rb vapor nanometric-thin cell

    Science.gov (United States)

    Hakhumyan, G.; Leroy, C.; Pashayan-Leroy, Y.; Sarkisyan, D.; Auzinsh, M.

    2011-08-01

    We have implemented the so-called λ-Zeeman technique (LZT) to investigate individual hyperfine transitions between Zeeman sublevels of the Rb atoms in a strong external magnetic field B in the range of 2500 - 5000 G (recently it was established that LZT is very convenient for the range of 10 - 2500 G). Atoms are confined in a nanometric thin cell (NTC) with the thickness L = λ, where λ is the resonant wavelength 794 nm for Rb D 1 line. Narrow velocity selective optical pumping (VSOP) resonances in the transmission spectrum of the NTC are split into several components in a magnetic field with the frequency positions and transition probabilities depending on the B-field. Possible applications are described, such as magnetometers with nanometric local spatial resolution and tunable atomic frequency references.

  20. Rb-intercalated C{sub 60} compounds studied by photoemission spectroscopies

    Energy Technology Data Exchange (ETDEWEB)

    Brambilla, A. [INFM - Dipartimento di Fisica, Politecnico di Milano, p.za L. da Vinci 32, I-20133 Milan (Italy)]. E-mail: alberto.brambilla@polimi.it; Giovanelli, L. [Sincrotrone Trieste S.C.p.A., Strada Statale 14, Km 163.5, I-34012 Basovizza, Trieste (Italy); Vilmercati, P. [Sincrotrone Trieste S.C.p.A., Strada Statale 14, Km 163.5, I-34012 Basovizza, Trieste (Italy); Cattoni, A. [INFM - Dipartimento di Fisica, Politecnico di Milano, p.za L. da Vinci 32, I-20133 Milan (Italy); Biagioni, P. [INFM - Dipartimento di Fisica, Politecnico di Milano, p.za L. da Vinci 32, I-20133 Milan (Italy); Goldoni, A. [Sincrotrone Trieste S.C.p.A., Strada Statale 14, Km 163.5, I-34012 Basovizza, Trieste (Italy); Finazzi, M. [INFM - Dipartimento di Fisica, Politecnico di Milano, p.za L. da Vinci 32, I-20133 Milan (Italy); Duo, L. [INFM - Dipartimento di Fisica, Politecnico di Milano, p.za L. da Vinci 32, I-20133 Milan (Italy)

    2005-06-15

    We report on a combined photoemission and inverse photoemission spectroscopy analysis on Rb{sub x}C{sub 60} compounds with different stoichiometries (0-bar x-bar 6). Apart from shifts and broadening of the spectral features associated to the different phase formed, we observe in the RbC{sub 60} phase the presence of the highest occupied molecular orbital (HOMO) shoulder and of its symmetric (with respect to the Fermi level) empty state. According to calculations, the metallicity of this phase and the presence of these electronic states may be taken as a fingerprint of the interplay between electron-electron and electron-phonon interactions in determining the electronic behavior of alkali metal fullerides.

  1. Superconductivity and ferromagnetism in hole-doped RbEuFe4As4

    Science.gov (United States)

    Liu, Yi; Liu, Ya-Bin; Tang, Zhang-Tu; Jiang, Hao; Wang, Zhi-Cheng; Ablimit, Abduweli; Jiao, Wen-He; Tao, Qian; Feng, Chun-Mu; Xu, Zhu-An; Cao, Guang-Han

    2016-06-01

    We discover a robust coexistence of superconductivity and ferromagnetism in an iron arsenide RbEuFe4As4 . The new material crystallizes in an intergrowth structure of RbFe2As2 and EuFe2As2 , such that the Eu sublattice turns out to be primitive instead of being body-centered in EuFe2As2 . The FeAs layers, featured by asymmetric As coordinations, are hole doped due to charge homogenization. Our combined measurements of electrical transport, magnetization, and heat capacity unambiguously and consistently indicate bulk superconductivity at 36.5 K in the FeAs layers and ferromagnetism at 15 K in the Eu sublattice. Interestingly, the Eu-spin ferromagnetic ordering belongs to a rare third-order transition, according to the Ehrenfest classification of phase transitions. We also identify an additional anomaly at ˜5 K, which is possibly associated with the interplay between superconductivity and ferromagnetism.

  2. Scattering mechanisms in Rb-doped single-crystal C{sub 60}

    Energy Technology Data Exchange (ETDEWEB)

    Crespi, V.H.; Cohen, M.L. [Department of Physics, University of California at Berkeley, Berkeley, California 94720 (United States)]|[Materials Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)

    1995-08-01

    The temperature-dependent resistivity of Rb-doped single-crystal C{sub 60} is analyzed within Bloch-Boltzmann transport theory yielding values of the electron-phonon coupling constant consistent with a superconducting {ital T}{sub {ital c}}{approx}30 K and isotope effect exponent {alpha}{approx}0.37 as long as the coupling is not primarily to the on-ball phonons of highest frequency. Disparate sources of information regarding the absolute magnitude of the resistivity are discussed in an attempt to form a more unified picture of the normal state and superconducting properties of both K-doped and Rb-doped C{sub 60}.

  3. Phosphorylation of pRb by cyclin D kinase is necessary for development of cardiac hypertrophy

    DEFF Research Database (Denmark)

    Hinrichsen, R.; Hansen, A.H.; Busk, P.K.;

    2008-01-01

    OBJECTIVES: A number of stimuli induce cardiac hypertrophy and may lead to cardiomyopathy and heart failure. It is believed that cardiomyocytes withdraw from the cell cycle shortly after birth and become terminally differentiated. However, cell cycle regulatory proteins take part in the development...... of hypertrophy, and it is important to elucidate the mechanisms of how these proteins are involved in the hypertrophic response in cardiomyocytes. MATERIALS AND METHODS, AND RESULTS: In the present study, by immunohistochemistry with a phosphorylation-specific antibody, we found that cyclin D-cdk4....../6-phosphorylated retinoblastoma protein (pRb) during hypertrophy and expression of an unphosphorylatable pRb mutant impaired hypertrophic growth in cardiomyocytes. Transcription factor E2F was activated by hypertrophic elicitors but activation was impaired by pharmacological inhibition of cyclin D-cdk4...

  4. Isolation of Brucella melitensis from a RB51-vaccinated seronegative goat.

    Science.gov (United States)

    Herrera, Enrique; Rivera, Aldo; Palomares, E Gabriela; Hernández-Castro, Rigoberto; Díaz-Aparicio, Efrén

    2011-08-01

    The purpose of this study is to determine the etiology of abortions presented in a goat herd declared as free of brucellosis and vaccinated with RB51 located in Mexico. The serological diagnosis of brucellosis in 33 animals was performed. The study included three goats that aborted in the last third of gestation and 15 goats that gave birth normally; samples of milk and vaginal exudate were subjected to bacteriological study. All animals were negative for serological diagnosis, and isolation of Brucella melitensis was achieved in a single goat from vaginal exudate. However, the particularity is that this goat was negative to the card, indirect ELISA, and radial immunodiffusion tests. Isolation of a field strain was confirmed by biochemical test resistance to rifampicin and PCR. It is concluded that a goat which aborted in the last third of gestation was found spreading B. melitensis through vaginal discharge despite being vaccinated with RB51 and seronegative for brucellosis.

  5. Study of Rb - vapor coated cell; atomic diffusion and cell curing process

    CERN Document Server

    Atutov, S N; Plekhanov, A I; Sorokin, V A

    2015-01-01

    We present the results of the study of an optical resonant cell filled by a vapor of the Rb atoms and coated with a non-stick polydimethylsiloxane (PDMS) polymer. We show that it is possible to define correctly the diffusion coefficient of the atoms in the coating, using geometric parameters of the cell and the vapor density in the cell volume only. The dependence of the diffusion coefficient on the cell curing time is presented. It is shown that the mysterious cell curing process can be explained in terms of the polymerization of the polymer coating by alkali atoms. Anomalous long dwell time of the Rb atoms on the PDMS coating is discussed as well.

  6. Desorption dynamics of heavy alkali metal atoms (Rb, Cs) off the surface of helium nanodroplets.

    Science.gov (United States)

    von Vangerow, J; Sieg, A; Stienkemeier, F; Mudrich, M; Leal, A; Mateo, D; Hernando, A; Barranco, M; Pi, M

    2014-08-21

    We present a combined ion imaging and density functional theory study of the dynamics of the desorption process of rubidium and cesium atoms off the surface of helium nanodroplets upon excitation of the perturbed 6s and 7s states, respectively. Both experimental and theoretical results are well represented by the pseudodiatomic model for effective masses of the helium droplet in the desorption reaction of meff/mHe ≈ 10 (Rb) and 13 (Cs). Deviations from this model are found for Rb excited to the 6p state. Photoelectron spectra indicate that the dopant-droplet interaction induces relaxation into low-lying electronic states of the desorbed atoms in the course of the ejection process.

  7. Rb-Sr and Sm-Nd Study of Asuka 881394: Evidence of "Late" Metamorphism

    Science.gov (United States)

    Nyquist, L. E.; Shih, C.-Y.; Reese, Y.; Takeda, H.

    2011-01-01

    The Asuka 881394 achondrite contains fossil Al-26 and Mn-53 [1,2,3] and has a Pb-207/Pb-206 age of 4566.5 plus or minus 0.2 Ma [3], the oldest for an achondrite. Preliminary results showed initial Sm-146/Sm-144 = (7.4 plus or minus 1.2) x 10(exp -3), indicative of an ancient age, but Rb-87 - Sr-87 and Sm-147 - Nd-143 ages of 4370 plus or minus 60 and 4490 plus or minus 20 Ma, resp. [1], were younger than expected from the presence of short-lived nuclides. We revisit the Rb-Sr and Sm-Nd chronology of A881394 in an attempt to establish whether late metamorphism led to inconsistency in its apparent ages.

  8. Ar-Ar and Rb-Sr Ages of the Tissint Olivine-phyric Martian Shergottite

    Science.gov (United States)

    Park, J.; Herzog, G. F.; Nyquist, L. E.; Shih, C.-Y.; Turin, B.; Lindsay, F. N.; Delaney, J. S.; Swisher, C. C., III; Agee, C.

    2013-01-01

    The fifth martian meteorite fall, Tissint, is an olivine-phyric shergottite that contains olivine macrocrysts (approximately 1.5 mm) [1]. [2] reported the Sm-Nd age of Tissint as 596 plus or minus 23 Ma along with Rb-Sr data that defined no isochron. [3] reported Lu-Hf and Sm-Nd ages of 583 plus or minus 86 Ma and 616 plus or minus 67 Ma, respectively. The cosmic-ray exposure ages of Tissint are 1.10 plus or minus 0.15 Ma based on 10Be [4], and 1.0-1.1 Ma, based on 3He, 21Ne, and 38Ar [5,6].We report Ar-Ar ages and Rb-Sr data.

  9. (87)Rb-stabilized 375-MHz Yb:fiber femtosecond frequency comb.

    Science.gov (United States)

    Schratwieser, Thomas C; Balskus, Karolis; McCracken, Richard A; Farrell, Carl; Leburn, Christopher G; Zhang, Zhaowei; Lamour, Tobias P; Ferreiro, Teresa I; Marandi, Alireza; Arnold, Aidan S; Reid, Derryck T

    2014-05-01

    We report a fully stabilized 1030-nm Yb-fiber frequency comb operating at a pulse repetition frequency of 375 MHz. The comb spacing was referenced to a Rb-stabilized microwave synthesizer and the comb offset was stabilized by generating a super-continuum containing a coherent component at 780.2 nm which was heterodyned with a (87)Rb-stabilized external cavity diode laser to produce a radio-frequency beat used to actuate the carrier-envelope offset frequency of the Yb-fiber laser. The two-sample frequency deviation of the locked comb was 235 kHz for an averaging time of 50 seconds, and the comb remained locked for over 60 minutes with a root mean squared deviation of 236 kHz.

  10. Rovibrational dynamics of the RbCs molecule in static electric fields. Classical study

    Energy Technology Data Exchange (ETDEWEB)

    Arnaiz, Pedro F.; Iñarrea, Manuel [Área de Física, Universidad de la Rioja, E-26006 Logroño (Spain); Salas, J. Pablo, E-mail: josepablo.salas@unirioja.es [Área de Física, Universidad de la Rioja, E-26006 Logroño (Spain)

    2012-04-02

    We study the classical dynamics of the RbCs molecule in the presence of a static electric field. Under the Born–Oppenheimer approximation, we perform a rovibrational investigation which includes the interaction of the field with the molecular polarizability. The stability of the equilibrium points and the phase space structure of the system are explored in detail. We find that, for strong electric fields or for energies close to the dissociation threshold, the molecular polarizability causes relevant effects on the system dynamics. -- Highlights: ► We study the classical rovibrational dynamics of the alkali polar dimer RbCs. ► In the model we consider the interaction of the field with the molecular polarizability. ► The potential energy surface is studied depending on the electric field strength. ► Using surfaces of section we study the phase space structure. ► We find that the molecular polarizability causes relevant effects on the system dynamics.

  11. Measurement of $R_{b}$ and $B_{r}(b \\to l\

    CERN Document Server

    Acciarri, M; Adriani, O; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Balandras, A; Ball, R C; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brigljevic, V; Brochu, F; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Button, A M; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chéreau, X J; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; Cozzoni, B; de la Cruz, B; Csilling, Akos; Cucciarelli, S; Dai, T S; van Dalen, J A; D'Alessandro, R; De Asmundis, R; Déglon, P L; Degré, A; Deiters, K; Della Volpe, D; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Dufournaud, D; Duinker, P; Durán, I; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Extermann, Pierre; Fabre, M; Faccini, R; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Hofer, H; Holzner, G; Hoorani, H; Hou, S R; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Khan, R A; Kamrad, D; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lassila-Perini, K M; Laurikainen, P; Lavorato, A; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Lugnier, L; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Marchesini, P A; Marian, G; Martin, J P; Marzano, F; Massaro, G G G; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Molnár, P; Monteleoni, B; Moulik, T; Muanza, G S; Muheim, F; Muijs, A J M; Musy, M; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Oh, Yu D; Organtini, G; Ostonen, R; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Paramatti, R; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Produit, N; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Sciarrino, D; Seganti, A; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stone, H; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Suter, H; Swain, J D; Szillási, Z; Sztaricskai, T; Tang, X W; Tauscher, Ludwig; Taylor, L; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, M; Wang, X L; Wang, Z M; Weber, A; Weber, M; Wienemann, P; Wilkens, H; Wu, S X; Wynhoff, S; Xia, L; Xu, Z Z; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhu, G Y; Zhu, R Y; Zichichi, A; Ziegler, F; Zilizi, G; Zöller, M

    2000-01-01

    We present a combined measurement of $\\Rb = \\Gamma(\\mathrm{Z \\rightarrow b\\overline{b}}) / \\Gamma(\\mathrm{Z} \\rightarrow\\mbox{hadro ns})$ and the semileptonic branching ratio of b quarks in Z decays, $\\Brbl$, using double-tag methods. Two analyses are performed on one million hadronic Z decays collected in 1994 and 1995. The first analysis exploits the capabilities of the silicon microvertex detector. The tagging of b-events is based on the large impact parameter of tracks from weak b-decays with respect to the $\\mathrm{e^+e^-}$ collision point. In the second analysis, a high-$p_t$ lepton tag is used to enhance the b-component in the sample and its momentum spectrum is used to constrain the model dependent uncertainties in the semileptonic b-decay. The analyses are combined in order to provide precise determinations of $\\Rb$ and $\\Brbl$:

  12. Cooperativity of Rb, Brca1, and p53 in malignant breast cancer evolution.

    Directory of Open Access Journals (Sweden)

    Prashant Kumar

    Full Text Available Breast cancers that are "triple-negative" for the clinical markers ESR1, PGR, and HER2 typically belong to the Basal-like molecular subtype. Defective Rb, p53, and Brca1 pathways are each associated with triple-negative and Basal-like subtypes. Our mouse genetic studies demonstrate that the combined inactivation of Rb and p53 pathways is sufficient to suppress the physiological cell death of mammary involution. Furthermore, concomitant inactivation of all three pathways in mammary epithelium has an additive effect on tumor latency and predisposes highly penetrant, metastatic adenocarcinomas. The tumors are poorly differentiated and have histologic features that are common among human Brca1-mutated tumors, including heterogeneous morphology, metaplasia, and necrosis. Gene expression analyses demonstrate that the tumors share attributes of both Basal-like and Claudin-low signatures, two molecular subtypes encompassed by the broader, triple-negative class defined by clinical markers.

  13. Raman spectra of the solid-solution between Rb sub 2 La sub 2 Ti sub 3 O sub 1 sub 0 and RbCa sub 2 Nb sub 3 O sub 1 sub 0

    CERN Document Server

    Kim, H J; Yun, H S

    2001-01-01

    A site preference of niobium atom in Rb sub 2 sub - sub x La sub 2 Ti sub 3 sub - sub x Nb sub x O sub 1 sub 0 (0.0<=x<=1.0) and RbLa sub 2 sub - sub x Ca sub x Ti sub 2 sub - sub x Nb sub 1 sub + sub x O sub 1 sub 0 (0.0<=x<= 2.0), which are the solid-solutions between Rb sub 2 La sub 2 Ti sub 3 O sub 1 sub 0 are RbCa sub 2 Nb sub 3 O sub 1 sub 0 , has been investigated by Raman spectroscopy. The Raman spectra of Rb sub 2 sub - sub x La sub 2 Ti sub 3 sub - sub x Nb sub x O sub 1 sub 0 (0.0<=x<=1.0) gave an evidence that niobium atoms substituted for titanium atoms preferably occupy the highly distorted outer octahedral sites rather than the central ones in triple-octahedral perovskite layers. In contrast, the Raman spectra of RbLa sub 2 sub - sub x Ca sub x Ti sub 2 sub - sub x Nb sub 1 sub + sub x O sub 1 sub 0 (0.0<=x<= 2.0) showed no clear information for the cationic arrangement in perovskite slabs. This difference indicated that a site preference of niobium atoms is observed onl...

  14. Superconductivity Emerging from an Electronic Phase Separation in the Charge Ordered Phase of RbFe2As2

    Science.gov (United States)

    Civardi, E.; Moroni, M.; Babij, M.; Bukowski, Z.; Carretta, P.

    2016-11-01

    75As, 87Rb, and 85Rb nuclear quadrupole resonance (NQR) and 87Rb nuclear magnetic resonance measurements in a RbFe2As2 iron-based superconductor are presented. We observe a marked broadening of the 75As NQR spectrum below T0≃140 K which is associated with the onset of a charge order in the FeAs planes. Below T0 we observe a power-law decrease in the 75As nuclear spin-lattice relaxation rate down to T*≃20 K . Below T* the nuclei start to probe different dynamics owing to the different local electronic configurations induced by the charge order. A fraction of the nuclei probes spin dynamics associated with electrons approaching a localization while another fraction probes activated dynamics possibly associated with a pseudogap. These different trends are discussed in light of an orbital selective behavior expected for the electronic correlations.

  15. Ginsenoside Rb1 ameliorates liver fat accumulation by upregulating perilipin expression in adipose tissue of db/db obese mice

    Directory of Open Access Journals (Sweden)

    Xizhong Yu

    2015-07-01

    Conclusion: G-Rb1 may improve insulin sensitivity in obese and diabetic db/db mice by reducing hepatic fat accumulation and suppressing adipocyte lipolysis; these effects may be mediated via the upregulation of perilipin expression in adipocytes.

  16. Energy-dependent relative charge transfer cross sections of Cs+ + Rb(5s, 5p)

    CERN Document Server

    Nguyen, H; Fléchard, X; DePaola, B D

    2013-01-01

    Magneto optical trap recoil ion momentum spectroscopy is used to measure energy-dependent charge exchange cross sections in the Cs+ + Rb(5s, 5p) system over a range of projectile energies from 3.2 to 6.4 keV. The measurements are kinematically complete and yield cross sections that are differential in collision energy, scattering angle, and initial and final states.

  17. Study of in-reactor creep of vanadium alloy in the HFIR RB-12J experiment

    Energy Technology Data Exchange (ETDEWEB)

    Strain, R.V.; Konicek, C.F.; Tsai, H. [Argonne National Lab., IL (United States)

    1996-10-01

    Biaxial creep specimens will be included in the HFIR RB-12J experiment to study in-reactor creep of the V-4Cr-4Ti alloy at {approx}500{degrees}C and 5 dpa. These specimens were fabricated with the 500-kg, heat (832665) material and pressurized to attain 0, 50, 100, 150, and 200 MPa mid-wall hoop stresses during the irradiation.

  18. Distribution of populations in excited states of electrodeless discharge lamp of Rb atoms

    Institute of Scientific and Technical Information of China (English)

    TAO ZhiMing; WANG YanFei; HONG YeLong; WANG DongYing; ZHANG ShengNan; ZHUANG Wei; CHEN JingBiao

    2013-01-01

    The intensity of fluorescence spectral lines of Rb atoms in the region of 350-1110 nm is measured in eletrodeless discharge lamp.The population ratio between the excited states is calculated according to the spontaneous transition probabilities with rate equations.At the same time,the population density of energy level is also obtained.The results provide the potential applications of electrodeless discharge lamp in atomic filter and optical frequency reference at higher excited states without a pumping laser.

  19. 2011 investigation of internal contamination with radioactive strontium following rubidium Rb 82 cardiac PET scan.

    Science.gov (United States)

    Pillai, Satish K; Chang, Arthur; Murphy, Matthew W; Buzzell, Jennifer; Ansari, Armin; Whitcomb, Robert C; Miller, Charles; Jones, Robert; Saunders, David P; Cavicchia, Philip; Watkins, Sharon M; Blackmore, Carina; Williamson, John A; Stephens, Michael; Morrison, Melissa; McNees, James; Murphree, Rendi; Buchanan, Martha; Hogan, Anthony; Lando, James; Nambiar, Atmaram; Torso, Lauren; Melnic, Joseph M; Yang, Lucie; Lewis, Lauren

    2014-01-01

    During routine screening in 2011, US Customs and Border Protection (CBP) identified 2 persons with elevated radioactivity. CBP, in collaboration with Los Alamos National Laboratory, informed the Food and Drug Administration (FDA) that these people could have increased radiation exposure as a result of undergoing cardiac Positron Emission Tomography (PET) scans several months earlier with rubidium Rb 82 chloride injection from CardioGen-82. We conducted a multistate investigation to assess the potential extent and magnitude of radioactive strontium overexposure among patients who had undergone Rb 82 PET scans. We selected a convenience sample of clinical sites in 4 states and reviewed records to identify eligible study participants, defined as people who had had an Rb 82 PET scan between February and July 2011. All participants received direct radiation screening using a radioisotope identifier able to detect the gamma energy specific for strontium-85 (514 keV) and urine bioassay for excreted radioactive strontium. We referred a subset of participants with direct radiation screening counts above background readings for whole body counting (WBC) using a rank ordering of direct radiation screening. The rank order list, from highest to lowest, was used to contact and offer voluntary enrollment for WBC. Of 308 participants, 292 (95%) had direct radiation screening results indistinguishable from background radiation measurements; 261 of 265 (98%) participants with sufficient urine for analysis had radioactive strontium results below minimum detectable activity. None of the 23 participants who underwent WBC demonstrated elevated strontium activity above levels associated with routine use of the rubidium Rb 82 generator. Among investigation participants, we did not identify evidence of strontium internal contamination above permissible levels. This investigation might serve as a model for future investigations of radioactive internal contamination incidents.

  20. Measurement and modelling of enhanced absorption Hanle effect resonances in {sup 85}Rb

    Energy Technology Data Exchange (ETDEWEB)

    Vilardi, Andrea; Tabarelli, Davide; Botti, Laura; Bertoldi, Andrea; Ricci, Leonardo [Dipartimento di Fisica, Universita di Trento, I-38100 Trento-Povo (Italy)], E-mail: andrea.bertoldi@institutoptique.fr

    2009-03-14

    We report on a detailed measurement of the enhanced absorption Hanle effect resonances in {sup 85}Rb. The effect was analysed with an experimental setup allowing for the control of each magnetic field component within 1 mG. The characterization deals with the dependence of resonances, observed under different magnetic field conditions, on the frequency, intensity and polarization of the exciting radiation field. An analytic model that precisely describes the resonance behaviour is discussed.

  1. Alignment dynamics of slow light diffusion in ultracold atomic $^{85}$Rb

    CERN Document Server

    Balik, S; Sukenik, C I; Havey, M D; Datsyuk, V M; Sokolov, I M; Kupriyanov, D V

    2014-01-01

    A combined experimental and theoretical investigation of time- and alignment-dependent propagation of light in an ultracold atomic gas of atomic $^{85}$Rb is reported. Coherences among the scattering amplitudes for light scattering off excited hyperfine levels produce strong variations of the light polarization in the vicinity of atomic resonance. Measurements are in excellent agreement with Monte-Carlo simulations of the multiple scattering process.

  2. 89Rb半衰期测量%Half-life Measurement of 89 Rb

    Institute of Scientific and Technical Information of China (English)

    郭晓清; 袁大庆; 徐利军; 陈克胜; 吴永乐; 郑艳明; 姚顺和

    2013-01-01

    89 Rb is an important fission product used for monitoring possible release of fission products from fuel element .The half-life is one of important nuclear parameters . The half-life of 89 Rb was determined using reference source method with two sets of HPGe detectors by place-relay way .In reference source method ,the ratio of net full-energy peak areas from the measure nuclide and the reference source was used to avoid the count correction caused by dead time and pileup .For the very short half-life of 89 Rb , the half-life iterative method was used in data analysis and the translation method was used in data unification .Finally ,the measured half-life of 89 Rb is (14.41 ± 0.04) min .%89 Rb是重要的裂变产物核素,半衰期是其一项非常重要的核参数。本文采用参考源法,运用双HPGe探头距离接续测定了89 Rb的半衰期。参考源法利用待测源和参考源的γ射线全能峰之比消除了测量过程中死时间和脉冲堆积带来的计数修正影响。由于89 Rb半衰期较短,数据分析运用了半衰期迭代法,并用平移法归一探头测量数据,最终实验测得89 Rb半衰期为(14.41±0.04) min。

  3. Production and measurement of Bose-Einstein condensate of 87Rb atomic gas

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The research platform for Bose-Einstein condensate in 87Rb atomic gas, which is composed of a double MOT configuration and a QUIC trap, was reported. The properties of the condensate were measured both in time-of-flight and in tight confinement by the absorption imaging method. The measurements agreed with the criterions of Bose-Einstein condensation phase transition. About 2×105 atoms were pure condensed.

  4. Production and measurement of Bose-Einstein condensate of 87Rb atomic gas

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The research platform for Bose-Einstein condensate in 87 Rb atomic gas,which is composed of a double MOT configuration and a QUIC trap,was reported.The properties of the condensate were measured both in time-of-flight and in tight confinement by the absorption imaging method.The measurements agreed with the criterions of Bose-Einstein condensation phase transition.About 2×10 5 atoms were pure condensed.

  5. Influences of Doppler effect on spontaneously generated coherence in a Rb atom

    Science.gov (United States)

    Song, Zhuo; Zheng, Y.

    2015-11-01

    We study the influences of Doppler effect on spontaneously generated coherence in a Rb atom driven by a probe field and two control fields. We show that the propagating directions of the lasers and the wave-vector mismatch have influence on the absorption properties of the atom. By employing the Doppler effect and spontaneous generated coherence, the ultra-narrow lines in probe absorption profile near two-photon resonant position can be obtained.

  6. Role of the Rb and p53 Tumor Suppressor Pathways in Mammary Tumorigenesis

    Science.gov (United States)

    2012-09-01

    kinase screen and off-patent drug screen) REPORTABLE OUTCOMES Jones, Robert., Jiang, Zhe ., Deng, Tao., Schimmer, AD., Moffat, J and...Robert., Jiang, Zhe ., Deng, Tao., Schimmer, AD., Moffat, J and Zacksenhaus, E. Role of the RB and p53 tumor suppressor pathways in mammary tumorigenesis...CDMRP 2011 Era of Hope Conference Jiang Z, Jones R, Liu JC, Deng T, Robinson T, Chung PE, Wang S, Herschkowitz Jl, Egan SE, Perou CM

  7. Ab initio studies on the spin-forbidden cooling transitions of the LiRb molecule.

    Science.gov (United States)

    You, Yang; Yang, Chuan-Lu; Zhang, Qing-Qing; Wang, Mei-Shan; Ma, Xiao-Guang; Liu, Wen-Wang

    2016-07-20

    The spin-forbidden cooling of the LiRb molecule is investigated based on ab initio quantum chemistry calculations. The multireference configuration interaction method is used to generate the potential energy curves (PECs) of the ground state X(1)Σ(+) and the low-lying excited states a(3)Σ(+), B(1)Π, and b(3)Π. The spin-orbit coupling effects for the PECs and the transition dipole moments (TDMs) between the X(1)Σ(+), b(3)Π and a(3)Σ(+) states are also calculated. The analytical functions for the PECs are deduced. The rovibrational energy levels, the spectroscopic parameters and the Franck-Condon factors (FCF) are determined by solving the Schrödinger equation of nuclear movement with the obtained analytical functions. The b(3)Π0 ↔ X(1)Σ(+) and b(3)Π1 ↔ X(1)Σ(+) transitions have highly diagonal distributed FCFs and non-zero TDMs, demonstrating that the LiRb molecule could be a very promising candidate for laser cooling. Therefore, a three-cycle laser cooling scheme for the molecule has been proposed based on these two spin-forbidden transitions. Using the radiative lifetime and linewidth calculated from the obtained TDM functions, we present further analysis of the cooling of LiRb and the corresponding KRb molecule. The transition b(3)Π0 ↔ X(1)Σ(+) is found to be a practical transition to cool the LiRb molecule, and a sub-microkelvin cool temperature could be reached for the KRb molecule using a similar laser cooling scheme.

  8. Absolute branching intensities in the decay of 92Rb to 92Sr

    CERN Document Server

    Lhersonneau, G; Rizzi, V; Alyakrinskiy, O; Lanchais, A; Volkov, Yu.M; Barzakh, A.E; Fedorov, D.V; Ionan, A.M; Ivanov, V.S; Mezilev, K.A; Moroz, F.V; Orlov, S.Yu; Panteleev, V.N; Lau, C; Bajeat, O; Essabaa, S; Leroy, R; Jardin, P; Stroe, L; 10.1103/PhysRevC.74.017308

    2006-01-01

    The branching of the 2+ to 0+ transition in 92Sr has been measured to 0.032(4) per 92Rb decay. It confirms an earlier measurement however discarded in nuclear data evaluations since in contradiction with accepted lower logft limits. The conflict could be solved assuming that close to half of the decay intensity, mostly as high-energy ground-state transitions, is missing in th edecay scheme.

  9. Synthesis and Characterization of the Rubidium Thiophosphate Rb 6 (PS 5 )(P 2 S 10 ) and the Rubidium Silver Thiophosphates Rb 2 AgPS 4 , RbAg 5 (PS 4 ) 2 and Rb 3 Ag 9 (PS 4 ) 4

    KAUST Repository

    Alahmary, Fatimah S.

    2016-02-18

    The metal thiophosphates Rb2AgPS4 (2), RbAg5(PS4)2 (3), and Rb3Ag9(PS4)4 (4) were synthesized by stoichiometric reactions, whereas Rb6(PS5)(P2S10) (1) was prepared with excess amount of sulfur. The compounds crystallize as follows: 1 monoclinic, P21/c (no. 14), a = 17.0123(7) Å, b = 6.9102(2) Å, c = 23.179(1) Å, β = 94.399(4)°; 2 triclinic, P ¯ (no. 2), a = 6.600(1) Å, b = 6.856(1) Å, c = 10.943(3) Å, α = 95.150(2)°, β = 107.338(2)°, γ = 111.383(2)°; 3 orthorhombic, Pbca (no. 61), a = 12.607(1) Å, b = 12.612(1) Å, c = 17.759(2) Å; 4 orthorhombic, Pbcm (no. 57), a = 6.3481(2) Å, b = 12.5782(4) Å, c = 35.975(1) Å. The crystal structures contain discrete units, chains, and 3D polyanionic frameworks composed of PS4 tetrahedral units arranged and connected in different manner. Compounds 1-3 melt congruently, whereas incongruent melting behavior was observed for compound 4. 1-4 are semiconductors with bandgaps between 2.3 and 2.6 eV and thermally stable up to 450 °C in an inert atmosphere. Copyright © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Status of lithium-filled specimen subcapsules for the HFIR-MFE-RB10J experiment

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, J.P.; Howell, M.; Lenox, K.E. [Oak Ridge National Lab., TN (United States)

    1998-09-01

    The HFIR-MFE-RB-10J experiment will be irradiated in a Removable Beryllium position in the HFIR for 10 reactor cycles, accumulating approximately 5 dpa in steel. The upper region of the capsule contains two lithium-filled subcapsules containing vanadium specimens. This report describes the techniques developed to achieve a satisfactory lithium fill with a specimen occupancy of 26% in each subcapsule.

  11. Disruption of Rb/E2F pathway results in increased cyclooxygenase-2 expression and activity in prostate epithelial cells.

    Science.gov (United States)

    Davis, Joanne N; McCabe, Michael T; Hayward, Simon W; Park, John M; Day, Mark L

    2005-05-01

    The loss of the retinoblastoma tumor suppressor gene (RB) is common in many human cancers, including prostate. We previously reported that engineered deletion of RB in prostate epithelial cells results in sustained cell growth in serum-free media, a predisposition to develop hyperplasia and dysplasia in prostate tissue recombinant grafts, and sensitization to hormonal carcinogenesis. Examining the molecular consequence of RB loss in this system, we show that cyclooxygenase-2 (COX-2) is significantly up-regulated following RB deletion in prostate tissue recombinants. To study the effect of RB deletion on COX-2 regulation, we generated wild-type (PrE) and Rb-/- (Rb-/-PrE) prostate epithelial cell lines rescued by tissue recombination. We show elevated COX-2 mRNA and protein expression in Rb-/-PrE cell lines with increased prostaglandin synthesis. We also find that loss of Rb leads to deregulated E2F activity, with increased expression of E2F target genes, and that exogenous expression of E2F1 results in elevated COX-2 mRNA and protein levels. COX-2 promoter studies reveal that E2F1 transcriptionally activates COX-2, which is dependent on the transactivation and DNA-binding domains of E2F1. Further analysis revealed that the E2F1 target gene, c-myb, is elevated in Rb-/-PrE cells and E2F1-overexpressing cells, whereas ectopic overexpression of c-myb activates the COX-2 promoter in prostate epithelial cells. Additionally, cotransfection with E2F1 and a dominant-negative c-myb inhibited E2F1 activation of the COX-2 promoter. Taken together, these results suggest activation of a transcriptional cascade by which E2F1 regulates COX-2 expression through the c-myb oncogene. This study reports a novel finding describing that deregulation of the Rb/E2F complex results in increased COX-2 expression and activity.

  12. Feshbach Resonances in Kerr Frequency Combs

    CERN Document Server

    Matsko, Andrey B

    2014-01-01

    We show that both the power and repetition rate of a frequency comb generated in a nonlinear ring resonator, pumped with continuous wave (cw) coherent light, are modulated. The modulation is brought about by the interaction of the cw background with optical pulses excited in the resonator, and occurs in resonators with nonzero high-order chromatic dispersion and wavelength-dependent quality factor. The modulation frequency corresponds to the detuning of the pump frequency from the eigenfrequency of the pumped mode in the resonator.

  13. 76 FR 12277 - Airworthiness Directives; Rolls-Royce plc RB211-Trent 768, 772, and 772B Turbofan Engines

    Science.gov (United States)

    2011-03-07

    ...-AD; Amendment 39-16620; AD 98-09-27R1] RIN 2120-AA64 Airworthiness Directives; Rolls-Royce plc RB211... of Rolls-Royce plc RB211-Trent 768 and 772 series turbofan engine thrust reverser hinge lugs and..., Amendment 39-10508 (63 FR 24911, May 6, 1998): 98-09-27R1 Rolls-Royce plc: Amendment 39-16620. Docket...

  14. Collisions of alkali-metal atoms Cs and Rb in the ground state. Spin exchange cross sections

    Science.gov (United States)

    Kartoshkin, V. A.

    2016-09-01

    Collisions of alkali-metal atoms 133Cs and 85Rb in the ground state are considered in the energy interval of 10-4-10-2 au. Complex cross sections of the spin exchange, which allow one to calculate the processes of polarization transfer and the relaxation times, as well as the magnetic resonance frequency shifts caused by spin exchange Cs-Rb collisions, are obtained.

  15. pRb inactivation in mammary cells reveals common mechanisms for tumor initiation and progression in divergent epithelia.

    Directory of Open Access Journals (Sweden)

    Karl Simin

    2004-02-01

    Full Text Available Retinoblastoma 1 (pRb and the related pocket proteins, retinoblastoma-like 1 (p107 and retinoblastoma-like 2 (p130 (pRb(f, collectively, play a pivotal role in regulating eukaryotic cell cycle progression, apoptosis, and terminal differentiation. While aberrations in the pRb-signaling pathway are common in human cancers, the consequence of pRb(f loss in the mammary gland has not been directly assayed in vivo. We reported previously that inactivating these critical cell cycle regulators in divergent cell types, either brain epithelium or astrocytes, abrogates the cell cycle restriction point, leading to increased cell proliferation and apoptosis, and predisposing to cancer. Here we report that mouse mammary epithelium is similar in its requirements for pRb(f function; Rb(f inactivation by T(121, a fragment of SV40 T antigen that binds to and inactivates pRb(f proteins, increases proliferation and apoptosis. Mammary adenocarcinomas form within 16 mo. Most apoptosis is regulated by p53, which has no impact on proliferation, and heterozygosity for a p53 null allele significantly shortens tumor latency. Most tumors in p53 heterozygous mice undergo loss of the wild-type p53 allele. We show that the mechanism of p53 loss of heterozygosity is not simply the consequence of Chromosome 11 aneuploidy and further that chromosomal instability subsequent to p53 loss is minimal. The mechanisms for pRb and p53 tumor suppression in the epithelia of two distinct tissues, mammary gland and brain, are indistinguishable. Further, this study has produced a highly penetrant breast cancer model based on aberrations commonly observed in the human disease.

  16. Growth and dielectric properties of KTiOPO4 and K1 - x Rb x TiOPO4 crystals

    Science.gov (United States)

    Gurtovoĭ, V. G.; Sheleg, A. U.; Guretskiĭ, S. A.; Kalanda, N. A.

    2008-07-01

    Methods of growth of KTiOPO4 and K1 - x Rb x TiOPO4 crystals of high optical quality have been optimized. The dielectric properties (permittivity and conductivity) of the crystals grown have been investigated at frequencies from 102 to 106 Hz in the temperature range from 100 to 350 K, along the [001] crystallographic direction. It is established that partial substitution of K+ ions with Rb+ ions leads to a decrease in the permittivity and conductivity.

  17. LIMD1 is more frequently altered than RB1 in head and neck squamous cell carcinoma: clinical and prognostic implications

    Directory of Open Access Journals (Sweden)

    Roy Anup

    2010-03-01

    Full Text Available Abstract Introduction To understand the role of two interacting proteins LIMD1 and pRB in development of head and neck squamous cell carcinoma (HNSCC, alterations of these genes were analyzed in 25 dysplastic head and neck lesions, 58 primary HNSCC samples and two HNSCC cell lines. Methods Deletions of LIMD1 and RB1 were analyzed along with mutation and promoter methylation analysis of LIMD1. The genotyping of LIMD1 linked microsatellite marker, hmlimD1, was done to find out any risk allele. The mRNA expression of LIMD1 and RB1 were analyzed by Q-PCR. Immunohistochemical analysis of RB1 was performed. Alterations of these genes were correlated with different clinicopathological parameters. Results High frequency [94% (78/83] of LIMD1 alterations was observed in the samples studied. Compare to frequent deletion and methylation, mutation of LIMD1 was increased during tumor progression (P = 0.007. Six novel mutations in exon1 and one novel intron4/exon5 splice-junction mutation were detected in LIMD1 along with a susceptible hmlimD1 (CA20 allele. Some of these mutations [42% (14/33] produced non-functional proteins. RB1 deletion was infrequent (27%. Highly reduced mRNA expression of LIMD1 (25.1 ± 19.04 was seen than RB1 (3.8 ± 8.09, concordant to their molecular alterations. The pRB expression supported this data. Tumors with LIMD1 alterations in tobacco addicted patients without HPV infection showed poor prognosis. Co-alterations of these genes led the worse patients' outcome. Conclusions Our study suggests LIMD1 inactivation as primary event than inactivation of RB1 in HNSCC development.

  18. Angular-momentum couplings in long-range Rb$_2$ Rydberg molecules

    CERN Document Server

    Anderson, David A; Raithel, Georg

    2014-01-01

    We study angular-momentum couplings in $^{87}$Rb$_2$ Rydberg molecules formed between Rydberg and 5S$_{1/2}$ ground-state atoms. We use a Fermi model that includes S-wave and P-wave singlet and triplet scattering of the Rydberg electron with the 5S$_{1/2}$ atom, along with the fine structure coupling of the Rydberg atom and hyperfine structure coupling of the 5S$_{1/2}$ atom. We discuss the effects of these couplings on the adiabatic molecular potentials. We obtain bound-state energies, lifetimes, and electric and magnetic dipole moments for the vibrational ground states of the $^{87}$Rb$(n$D$+5$S$_{1/2})$ molecules in all adiabatic potentials, with fine and hyperfine structure included. We also study the effect of the hyperfine structure on the deep $^3$S-wave- and $^3$P-wave-dominated adiabatic molecular potentials, which support high-$\\ell$ $^{87}$Rb$_2$ Rydberg molecules.

  19. UV laser induced desorption of CsI and RbI ion clusters

    Science.gov (United States)

    Fernández-Lima, F. A.; Ponciano, C. R.; Filho, H. D. Fonseca; Pedrero, E.; Chaer Nascimento, M. A.; da Silveira, E. F.

    2006-09-01

    Experimental results of laser sputtering of cesium and rubidium iodide secondary ions are presented. A TOF mass spectrometer, operating in linear mode, continuous extraction for positive or negative ions, was used for the analysis of (CsI) nCs +, (CsI) nI -, (RbI) nRb + and (RbI) nI - ion emission as a function of the laser irradiance. Experimental data show that the cluster ion emission yields decrease exponentially with n, for all the laser irradiances applied. Theoretical analysis of the clusters structure was performed using density functional theory at the B3LYP/LACV3P level, for the positive and negative cluster series. A quasi-equilibrium evolution of the clusters is proposed to extract a parameter characteristic of the cluster recombination process: the effective temperature. The hypothesis of the atomic species' recombination (during the expansion of a high density highly ionized cloud) leading to cluster formation is confirmed to some extent in a second set of experiments: the UV laser ablation of a mixed and non-mixed cesium iodide and potassium bromide targets. These experiments show that the emission yields contain contributions from both the recombination process and from the sample stoichiometry, even for high laser irradiances.

  20. Retinoblastoma (Rb) regulates laminar dendritic arbor reorganization in retinal horizontal neurons

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Rodrigo [St. Jude Children' s Research Hospital; Davis, Denise [St. Jude Children' s Research Hospital; Dyer, Michael [St. Jude Children' s Research Hospital; Kerekes, Ryan A [ORNL; Zhang, Jiakun [St. Jude Children' s Research Hospital; Bayazitov, Ildar [St. Jude Children' s Research Hospital; Hiler, Daniel [St. Jude Children' s Research Hospital; Karakaya, Mahmut [ORNL; Frase, Sharon [St. Jude Children' s Research Hospital; Gleason, Shaun Scott [ORNL; Zakharenko, Stanislav S [ORNL; Johnson, Dianna [University of Tennessee Health Science Center, Memphis

    2011-01-01

    Neuronal differentiation with respect to the acquisition of synaptic competence needs to be regulated precisely during neurogenesis to ensure proper formation of circuits at the right place and time in development.This regulation is particularly important for synaptic triads among photoreceptors, horizontal cells (HCs), and bipolar cells in the retina, because HCs are among the rst cell types produced during development, and bipolar cells are among thel ast.HCs undergo a dramatic transition from vertically oriented neurites that form columnar arbors to overlapping laminar dendritic arbors with differentiation.However, how this process is regulated and coordinated with differentiation of photoreceptors and bipolar cells remains unknown. Previous studies have suggested that there tino-blastoma(Rb) tumor suppressor gene may play a role in horizontal cell differentiation and synaptogenesis. By combining genetic mosaic analysis of individual synaptictriads with neuroanatomic analyses and multiphoton live imaging of developing HCs, we found that Rb plays a cell-autonomous role in there organization of horizontal cell neurites as they differentiate. Aberrant vertical processes in Rb-de cient HCs form ectopic synapses with rods in the outer nuclear layer but lack bipolar dendrites. Although previous reports indicate that photoreceptor abnormalities can trigger formation of ectopic synapses, our studies now demonstrate that defects in a post synaptic partner contribute to the formation of ectopic photoreceptor synapses in the mammalian retina.