WorldWideScience

Sample records for beta spectroscopy

  1. Simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  2. Simultaneous beta/gamma digital spectroscopy

    Science.gov (United States)

    Farsoni, Abdollah T.

    A state-of-the-art radiation detection system for simultaneous spectroscopy of beta-particles and gamma-rays has been developed. The system utilizes a triple-layer phoswich detector and a customized Digital Pulse Processor (DPP) built in our laboratory. The DPP board was designed to digitally capture the analog signal pulses and, following several digital preprocessing steps, transfer valid pulses to the host computer for further digital processing. A MATLAB algorithm was developed to digitally discriminate beta and gamma events and reconstruct separate beta and gamma-ray energy spectra with minimum crosstalk. The spectrometer proved to be an effective tool for recording separate beta and gamma-ray spectra from mixed radiation fields. The system as a beta-gamma spectrometer will have broad-ranging applications in nuclear non-proliferation, radioactive waste management, worker safety, systems reliability, dose assessment, and risk analysis.

  3. In-trap decay spectroscopy for {beta}{beta} decays

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, Thomas

    2011-01-18

    The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in {beta}{beta} decays. This technique has been developed at TRIUMF in Vancouver, Canada. It facilitates one of TRIUMF's Ion Traps for Atomic and Nuclear science (TITAN), the Electron Beam Ion Trap (EBIT) that is used as a spectroscopy Penning trap. Radioactive ions, produced at the radioactive isotope facility ISAC, are injected and stored in the spectroscopy Penning trap while their decays are observed. A key feature of this technique is the use of a strong magnetic field, required for trapping. It radially confines electrons from {beta} decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and {beta} detection with almost no {beta}-induced background at the X-ray detector, allowing weak EC branches to be measured. Furthermore, the combination of several traps allows one to isobarically clean the sample prior to the in-trap decay spectroscopy measurement. This technique has been developed to measure ECBRs of transition nuclei in {beta}{beta} decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in {beta}{beta} decays. These branches are typically of the order of 10{sup -5} and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating {beta} background at theX-ray detector. Additionally, X-rays are attenuated by the material where the radioactive sample is implanted. To overcome these limitations, the technique of in-trap decay spectroscopy has been developed. In this work, the EBIT was connected to the TITAN beam line and has been commissioned. Using the developed beam diagnostics, ions were injected into the Penning trap and systematic studies on injection and storage optimization were performed. Furthermore, Ge

  4. A system for simultaneous beta and gamma spectroscopy

    Science.gov (United States)

    Farsoni, A. T.; Hamby, D. M.

    2007-08-01

    A state-of-the-art radiation detection system for real-time and simultaneous spectroscopy of beta-particles and gamma-rays has been developed. The system utilizes a triple-layer phoswich detector and a customized Digital Pulse Processor (DPP) designed and built in our laboratory. The DPP board digitally captures the analog signal pulses and, following several digital preprocessing steps, transfers valid pulses to the host computer for further digital processing. A resolving algorithm also was developed to digitally discriminate beta and gamma events, and reconstruct separate beta and gamma-ray energy spectra with minimal crosstalk. The spectrometer has proven to be an effective tool for recording separate beta and gamma-ray spectra from mixed radiation fields. The system as a beta-gamma spectrometer will have broad-ranging applications in nuclear non-proliferation, radioactive waste management, worker safety, systems reliability, dose assessment, and risk analysis.

  5. $\\beta$-decay studies using total-absorption spectroscopy

    CERN Document Server

    Algora, A; García-Borge, M J; Cano-Ott, D; Collatz, R; Courtin, S; Dessagne, P; Fraile-Prieto, L M; Gadea, A; Gelletly, W; Hellström, M; Janas, Z; Jungclaus, A; Kirchner, R; Karny, M; Le Scornet, G; Miehé, C; Maréchal, F; Moroz, F; Nacher, E; Poirier, E; Roeckl, E; Rubio, B; Rykaczewski, K; Taín, J L; Tengblad, O; Wittmann, V

    2004-01-01

    $\\beta$-decay experiments are a primary source of information for nuclear-structure studies and at the same time complementary to in- beam investigations of nuclei far from stability. Although both types of experiment are mainly based on $\\gamma$-ray spectroscopy, they face different experimental problems. The so-called " Pandemonium effect " is a critical problem in $\\beta$-decay if we are to test theoretically calculated transition probabilities. In this contribution we will present a solution to this problem using total absorption spectroscopy methods. We will also present some examples of experiments carried out with the Total Absorption Spectrometer (TAS) at GSI and describe a new device LUCRECIA recently installed at CERN.

  6. Beta-delayed neutron spectroscopy using trapped radioactive ions

    OpenAIRE

    Yee, Ryan Matthew

    2013-01-01

    A novel technique for beta-delayed neutron spectroscopy has been developed using trapped radioactive ions. The neutron energy spectrum was reconstructed by measuring the time of flight (TOF) of the nuclear recoil following neutron emission, thereby avoiding all the challenges associated with neutron detection such as backgrounds from scattered neutrons and gamma rays and complicated detector-response functions. A proof-of-principle measurement was conducted on 137I+ by delivering ions from a ...

  7. High efficiency beta-decay spectroscopy using a planar germanium double-sided strip detector

    International Nuclear Information System (INIS)

    Beta-decay spectroscopy experiments are limited by the detection efficiency of ions and electrons in the experimental setup. While there is a variety of different experimental setups in use for beta-decay spectroscopy, one popular choice is silicon double-sided strip detectors (DSSD). The higher Z of Ge and greater availability of thicker detectors as compared to Si potentially offer dramatic increases in the detection efficiency for beta-decay electrons. In this work, a planar GeDSSD has been commissioned for use in beta-decay spectroscopy experiments at the National Superconducting Cyclotron Laboratory (NSCL). The implantation response of the detector and its beta-decay detection efficiency is discussed. -- Highlights: • A planar Ge double-sided strip detector is implemented for decay spectroscopy. • Dual range preamplifiers provide sensitivity to both heavy ions and beta-decay electrons. • Beta-decay electron detection efficiencies greater than 50% are demonstrated. • Based on comparisons with simulation, an efficiency of roughly 90% is expected

  8. Double beta decays and fundamental laws studied by ultra rare-decay nuclear spectroscopy

    International Nuclear Information System (INIS)

    Recent works on double beta decays and on fundamental laws, which are studied by means of the ultra rare-decay nuclear spectroscopy, are described. Subjects discussed here include unique features of the nuclear spectroscopic method for studying basic problems of nuclear and particle interactions, neutrinos and weak interactions studied by double-beta and gamma spectroscopy, weakly interacting dark matters studied by nuclear recoil spectroscopy, exotic K X-ray transitions and charge non-conservation, and exotic nuclear transitions associated with nucleon decays. (author)

  9. $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with radioactive At beams

    CERN Multimedia

    We propose to study the $\\beta$-delayed fission, laser spectroscopy and radioactive decay of the newly available pure beams of neutron-deficient and neutron-rich astatine (Z=85) isotopes. The fission probability and the fission fragment distribution of the even-even isotopes $^{194,196}$Po following the $\\beta$-decay of the isotopes $^{194,196}$At will be studied with the Windmill setup. In-source laser spectroscopy will be performed on the entire astatine isotopic chain, using a combination of the Windmill setup, ISOLTRAP MR-ToF and ISOLDE Faraday. Radioactive decay data will be acquired at the Windmill setup throughout those studies and contribute to the global understanding of the phenomenon of shape coexistence in the neutron-deficient lead region.

  10. Measurement of Moments and Radii of Light Nuclei by Collinear Fast-Beam Laser Spectroscopy and $\\beta$-NMR Spectroscopy

    CERN Multimedia

    Marinova, K P

    2002-01-01

    Nuclear Moments and radii of light unstable isotopes are investigated by applying different high-sensitivity and high-resolution techniques based on collinear fast-beam laser spectroscopy. A study of nuclear structure in the sd shell is performed on neon isotopes in the extended chain of $^{17-28}$Ne, in particular on the proton-halo candidate $^{17}$Ne. Measurements of hyperfine structure and isotope shift have become possible by introducing an ultra-sensitive non-optical detection method which is based on optical pumping, state-selective collisional ionization and $\\beta$-activity counting. The small effect of nuclear radii on the optical isotope shifts of light elements requires very accurate measurements. The errors are dominated by uncertainties of the Doppler shifts which are conventionally determined from precisely measured acceleration voltages. These uncertainties are removed by measuring the beam energy with simultaneous excitation of two optical lines in parallel / antiparallel beam configuration. ...

  11. Ground-state properties of K-isotopes from laser and $\\beta$-NMR spectroscopy

    CERN Multimedia

    Lievens, P; Rajabali, M M; Krieger, A R

    By combining high-resolution laser spectroscopy with $\\beta$-NMR spectroscopy on polarized K-beams we aim to establish the ground-state spins and magnetic moments of the neutron-rich $^{48,49,50,51}$K isotopes from N=29 to N=32. Spins and magnetic moments of the odd-K isotopes up to N=28 reveal an inversion of the ground-state, from the normal $\\,{I}$=3/2 ($\\pi{d}_{3/2}^{-1}$) in $^{41-45}$K$\\to\\,{I}$=1/2 ($\\pi{s}_{1/2}^{-1}$) in $^{47}$K. This inversion of the proton single particle levels is related to the strong proton $d_{3/2}$ - neutron $f_{7/2}$ interaction which lowers the energy of the $\\pi{d}_{3/2}$ single particle state when filling the $\

  12. Trapped-ion decay spectroscopy towards the determination of ground-state components of double-beta decay matrix elements

    CERN Document Server

    Brunner, T; Andreoiu, C; Brodeur, M; Delheji, P; Ettenauer, S; Frekers, D; Gallant, A T; Gernhäuser, R; Grossheim, A; Krücken, R; Lennarz, A; Lunney, D; Mücher, D; Ringle, R; Simon, M C; Simon, V V; Sjue, S K L; Zuber, K; Dilling, J

    2013-01-01

    A new technique has been developed at TRIUMF's TITAN facility to perform in-trap decay spectroscopy. The aim of this technique is to eventually measure weak electron capture branching ratios (ECBRs) and by this to consequently determine GT matrix elements of $\\beta\\beta$ decaying nuclei. These branching ratios provide important input to the theoretical description of these decays. The feasibility and power of the technique is demonstrated by measuring the ECBR of $^{124}$Cs.

  13. Ultrafast optical responses of {beta}-carotene and lycopene probed by sub-20-fs time-resolved coherent spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, M.; Sugisaki, M. [CREST-JST and Department of Physics, Osaka City University, Osaka 558-8585 (Japan); Gall, A.; Robert, B. [CEA, Institut de Biologie et Technologies de Saclay, and CNRS, Gif-sur-Yvette F-91191 (France); Cogdell, R.J. [IBLS, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Hashimoto, H., E-mail: hassy@sci.osaka-cu.ac.j [CREST-JST and Department of Physics, Osaka City University, Osaka 558-8585 (Japan)

    2009-12-15

    We investigate how structural distortions in carotenoid cause decoherences of its high-frequency vibrational modes by applying the sub-20-fs time-resolved transient grating spectroscopy to {beta}-carotene and lycopene. The results indicate that the C=C central stretching mode shows significant loss of coherence under the effects of the steric hindrance between {beta}-ionone ring and polyene backbone, whereas the other high-frequency modes do not show such dependency on the structural distortions.

  14. Part I: $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with astatine beams; Part II: Delineating the island of deformation in the light gold isotopes by means of laser spectroscopy

    CERN Document Server

    Andreyev, Andrei

    2013-01-01

    Part I: $\\beta$-delayed fission, laser spectroscopy and shape-coexistence studies with astatine beams; Part II: Delineating the island of deformation in the light gold isotopes by means of laser spectroscopy

  15. Harmonic Force Spectroscopy Reveals a Force-Velocity Curve from a Single Human Beta Cardiac Myosin Motor

    DEFF Research Database (Denmark)

    Sung, Jongmin; Nag, Suman; Vestergaard, Christian L.;

    2014-01-01

    human beta cardiac myosin S1. We also compare load-velocity curves for wild-type motors with load-velocity curves of mutant forms that cause hypertrophic or dilated-cardiomyopathy (HCM or DCM), in order to understand the effects of mutations on the contractile cycle at the single molecule level....... is slow under high load and fast under low load. We use a new, simple method we call "harmonic force spectroscopy" to extract a load-velocity relationship from a single human beta cardiac myosin II motor (S1). With a dual-beam optical trap, we hold an actin dumbbell over a single myosin molecule...

  16. Study on the complexation of isoquercitrin with {beta}-cyclodextrin and its derivatives by spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yunlong; Qiao Xiaona; Li Wenchao; Zhou Yehong; Jiao Yong [Research Center of Environmental Science and Engineering, School of Chemistry and Chemical Engineering, Shanxi University, Wu Cheng Road 36, Taiyuan 030006 (China); Yang Cheng [Department of Applied Chemistry, Osaka University, Suita 565-0871 (Japan); Dong Chuan, E-mail: dc@sxu.edu.cn [Research Center of Environmental Science and Engineering, School of Chemistry and Chemical Engineering, Shanxi University, Wu Cheng Road 36, Taiyuan 030006 (China); Inoue, Yoshihisa [Department of Applied Chemistry, Osaka University, Suita 565-0871 (Japan); Shuang, Shaomin, E-mail: smshuang@sxu.edu.cn [Research Center of Environmental Science and Engineering, School of Chemistry and Chemical Engineering, Shanxi University, Wu Cheng Road 36, Taiyuan 030006 (China)

    2009-09-14

    The inclusion complexes of isoquercitrin (IQ) with cyclodextrins (CDs) including {beta}-cyclodextrin ({beta}-CD), hydroxypropyl-{beta}-cyclodextrin (HP-{beta}-CD) and dimethyl-{beta}-cyclodextrin (DM-{beta}-CD) have been investigated using the methods of steady-state fluorescence, UV-vis absorption and induced circular dichroism. The stoichiometric ratio of the three complexes was found to be 1:1 and the stability constants (K) were estimated from spectrofluorometric titrations, as well as the thermodynamic parameters. Maximum inclusion ability was measured in the case of DM-{beta}-CD due to the increased hydrophobicity of the host cavity, followed by HP-{beta}-CD and {beta}-CD. The effect of pH on the complexation process was also quantitatively assessed. IQ exists in different molecular forms depending on pH and {beta}-CDs were most suitable for inclusion of the neutral form of IQ. The phase-solubility diagrams obtained with {beta}-CD, HP-{beta}-CD and DM-{beta}-CD were all classical A{sub L} type. And DM-{beta}-CD provided the best solubility enhancement, 12.3-fold increase compared to 2.8- and 7.5-fold increase for {beta}-CD and HP-{beta}-CD. The apparent stability constants obtained from the solubility data at 25 deg. C were comparable with those obtained from the fluorescence assays. Moreover, {sup 1}H NMR was carried out, which revealed that the IQ favorably inserted into the inner cavity from the chromone part instead of the phenyl part, which was in agreement with molecular modeling studies.

  17. Beta dose rates derived from gamma spectroscopy and low beta anticoincident system of various environmental materials, mainly of archaeological origin

    International Nuclear Information System (INIS)

    Beta dose-rates (BDR) have been derived from tephras, pumices and pottery of archaeological origin. The BDRs were obtained from two counting systems: (1) gamma spectrometry through appropriate conversion of gamma activity to U, Th, 40K concentration values, and (2) by counting total beta, using a gas-flow sample detector in an anticoincidence mode of counting. Assuming radioactive equilibrium in the U and Th series, the two methods of obtaining BDRs are compared. The degree of disequilibrium, the calibration, and radon escape are critically considered. The employment of either method to swift BDR measurements for the TL dating is discussed. The radioactivity measurements of tephras were used also to provenance those, as Santorini volcano might had not been the only eruption in the Aegean in the 2nd mill. B.C., it might have experienced more than one eruptive phase. BDRs in the samples ranged from 13 to about 470 mrads/year and the agreement between the two methods were in general satisfactory. 12 refs.; 2 figs.; 2 tabs

  18. Total absorption γ-ray spectroscopy of beta delayed neutron emitters

    Science.gov (United States)

    Valencia, E.; Algora, A.; Tain, J. L.; Rice, S.; Agramunt, J.; Zakari-Issoufou, A.-A.; Porta, A.; Fallot, M.; Jordan, M. D.; Molina, F.; Estevez, E.; Bowry, M.; Bui, V. M.; Caballero-Folch, R.; Cano-Ott, D.; Eloma, V.; Eronen, T.; Garcia, A.; Gomez-Hornillos, M. B.; Gorlychev, V.; Hakala, J.; Jokinen, A.; Kondev, F. G.; Martinez, T.; Moore, I.; Rissanen, J.; Ńystö, J.; Penttilä, H.; Kankainen, A.; Rubio, B.; Gelletly, W.; Perez, A.; Podolyak, Zs.; Regan, P. H.; Farrelly, G. F.; Weber, C.; Mendoza, E.; Igisol People

    2013-06-01

    Preliminary results of the data analysis of the beta decay of 94Rb using a novel - segmented- total absorption spectrometer are shown in this contribution. This result is part of a systematic study of important contributors to the decay heat problem in nuclear reactors. In this particular case the goal is to determine the beta intensity distribution below the neutron separation energy and the gamma/beta competition above.

  19. Total Absorption Gamma-Ray Spectroscopy of 87Br, 88Br and 94Rb Beta-Delayed Neutron Emitters

    CERN Document Server

    Valencia, E; Algora, A; Agramunt, J; Rubio, B; Rice, S; Gelletly, W; Regan, P; Zakari-Issoufou, A -A; Fallot, M; Porta, A; Rissanen, J; Eronen, T; Aysto, J; Batist, L; Bowry, M; Bui, V M; Caballero-Folch, R; Cano-Ott, D; Elomaa, V -V; Estevez, E; Farrelly, G F; Garcia, A R; Gomez-Hornillos, B; Gorlychev, V; Hakala, J; Jordan, M D; Jokinen, A; Kolhinen, V S; Kondev, F G; Martinez, T; Mendoza, E; Moore, I; Penttila, H; Podolyak, Zs; Reponen, M; Sonnenschein, V; Sonzogni, A A

    2016-01-01

    We investigate the decay of 87Br, 88Br and 94Rb using total absorption gamma-ray spectroscopy. These important fission products are beta-delayed neutron emitters. Our data show considerable 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 235U fission at cooling times in the range 1 to 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 gamma emission from neutron unbound s...

  20. Dielectric spectroscopy in benzophenone: the beta relaxation and its relation to the mode-coupling Cole-Cole peak.

    Science.gov (United States)

    Pardo, L C; Lunkenheimer, P; Loidl, A

    2007-09-01

    We report a thorough characterization of the glassy dynamics of benzophenone by broadband dielectric spectroscopy. We detect a well-pronounced beta relaxation peak developing into an excess wing with increasing temperature. A previous analysis of results from Optical-Kerr-effect measurements of this material within the mode-coupling theory revealed a high-frequency Cole-Cole peak. We address the question if this phenomenon also may explain the Johari-Goldstein beta relaxation, a so-far unexplained spectral feature inherent to glass-forming matter, mainly observed in dielectric spectra. Our results demonstrate that according to the present status of theory, both spectral features seem not to be directly related.

  1. Development of a portable triple silicon detector telescope for beta spectroscopy and skin dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Helt-Hansen, J

    2000-11-01

    It is now recognized that beta radiation can be a significant radiation problem for exposure of the skin. There is thus a need for a portable and rugged active beta dosemeter-spectrometer to carry out immediate measurements of doses and energies of beta particles even in the presence of photon radiation. The main objective of this report is to describe the development of such an instrument. A beta-spectrometer has been developed consisting of three silicon surface barrier detectors with the thickness: 50{mu}m/150{mu}m/7000{mu}m covered by a 2 {mu}m thick titanium window. The spectrometer is capable of measuring electron energies from 50 keV to 3.5 MeV. The spectrometer is characterized by a compact low weight design, achieved by digital signal processing beginning at an early stage in the signal chain. 255 channels are available for each of the three detectors. The spectrometer is controlled by a laptop computer, which also handles all subsequent data analysis. By use of coincidence/anti-coincidence considerations of the absorbed energy in the three detector elements, counts caused by electrons are separated from those originating from photons. The electron energy distribution is multiplied by a set of conversion coefficients to obtain the dose at 0.07 mm tissue. Monte Carlo calculations has been used to derive the conversion coefficients and to investigate the influence of noise and the design of detector assembly on the performance of the spectrometer. This report describes the development of the spectrometer and its mode of operation, followed by a description of the Monte Carlo calculations carried out to obtain the conversion coefficients. Finally is the capability of the telescope spectrometer to measure beta and photon spectra as well as beta dose rates in pure beta and mixed beta/photon radiation fields described. (au)

  2. {beta}-Lactam antibiotics epitope mapping with STD NMR spectroscopy: a study of drug-human serum albumin interaction

    Energy Technology Data Exchange (ETDEWEB)

    Milagre, Cintia D. F.; Cabeca, Luis F.; Almeida, Wanda P.; Marsaioli, Anita J., E-mail: cmilagre@rc.unesp.br [Institute of Chemistry, University of Campinas (UNICAMP), SP (Brazil)

    2012-03-15

    Molecular recognition events are key issues in many biological processes. STD NMR (saturation transfer difference nuclear magnetic resonance spectroscopy) is one of the techniques used to understand such biological interactions. Herein, we have investigated the interactions of four {beta}-lactam antibiotics belonging to two classes (cephalosporins and penicillins) with human serum albumin (HSA) by {sup 1}H STD NMR revealing that the interaction between the aromatic moiety and HSA is responsible for the binding efficiency. Thus, the structural differences from the five to six-membered thio ring in penicillins and cephalosporins do not seem to influence antibiotic albumin interactions. (author)

  3. Anodic oxides on a beta type Nb-Ti alloy and their characterization by electrochemical impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Woldemedhin, Michael Teka; Hassel, Achim Walter [Max Planck Institut fuer Eisenforschung GmbH, Duesseldorf (Germany); Institute for Chemical Technology of Inorganic Materials, Johannes Kepler University, Linz (Austria); Raabe, Dierk [Max Planck Institut fuer Eisenforschung GmbH, Duesseldorf (Germany)

    2010-04-15

    Anodic oxides were grown on the surface of an electropolished (Ti-30 at% Nb) beta-titanium ({beta}-Ti) alloy by cyclic voltammetry. The scan rate was 100 mV s{sup -1} between 0 and 8 V in increments of l V in an acetate buffer of pH 6.0. Electrochemical impedance spectroscopy was carried out right after each anodic oxide growth increment to study the electronic properties of the oxide/electrolyte interface in a wide frequency range from 100 kHz to 10 MHz with an AC perturbation voltage of 10 mV. A film formation factor of 2.4 nm V{sup -1} was found and a relative permittivity number (dielectric constant) of 42.4 was determined for the oxide film formed. Mott-Schottky analysis on a potentiostatically formed 7 nm thick oxide film was performed to assess the semiconducting properties of the mixed anodic oxide grown on the alloy. A flat band potential of -0.47 V (standard hydrogen electrode, SHE) was determined, connected to a donor density of 8.2 x 10{sup 17} cm{sup -3}. {beta}-Ti being highly isotropic in terms of mechanical properties should be superior to the stiffer {alpha}-Ti compound. Its application, however, requires a passivation behaviour comparable or better than {alpha}-Ti which in fact is found. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  4. Estimating Vegetation Beta Diversity from Airborne Imaging Spectroscopy and Unsupervised Clustering

    Directory of Open Access Journals (Sweden)

    Claire A. Baldeck

    2013-04-01

    Full Text Available Airborne remote sensing has an important role to play in mapping and monitoring biodiversity over large spatial scales. Techniques for applying this technology to biodiversity mapping have focused on remote species identification of individual crowns; however, this requires collection of a large number of crowns to train a classifier, which may limit the usefulness of this approach in many study regions. Based on the premise that the spectral variation among sites is related to their ecological dissimilarity, we asked whether it is possible to estimate the beta diversity, or turnover in species composition, among sites without the use of training data. We evaluated alternative methods using simulated communities constructed from the spectra of field-identified tree and shrub crowns from an African savanna. A method based on the k-means clustering of crown spectra produced beta diversity estimates (measured as Bray-Curtis dissimilarity among sites with an average pairwise correlation of ~0.5 with the true beta diversity, compared to an average correlation of ~0.8 obtained by a supervised species classification approach. When applied to savanna landscapes, the unsupervised clustering method produced beta diversity estimates similar to those obtained from supervised classification. The unsupervised method proposed here can be used to estimate the spatial structure of species turnover in a landscape when training data (e.g., tree crowns are unavailable, providing top-down information for science, conservation and ecosystem management applications.

  5. Beta-delayed gamma and proton spectroscopy near the Z=N line

    Energy Technology Data Exchange (ETDEWEB)

    Kankainen, A.; Eronen, T.; Hager, U.; Hakala, J.; Huang, W.; Huikari, J.; Jokinen, A.; Kopecky, S.; Moore, I.; Nieminen, A.; Penttilae, H.; Rinta-Antila, S.; Wang, Y.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics, P.O. Box 35, Jyvaeskylae (Finland); Eliseev, S.A. [Petersburg Nuclear Physics Inst. (Russian Federation); GSI, Darmstadt (Germany); Fox, S.P.; Jenkins, D. [University of York, Department of Physics, Heslington (United Kingdom); Novikov, Yu.N.; Vorobjev, G.K. [Petersburg Nuclear Physics Inst. (Russian Federation); St. Petersburg Univ. (Russian Federation); Popov, A.V.; Seliverstov, D.M. [Petersburg Nuclear Physics Institute, Petersburg (Russian Federation); Schatz, H. [Michigan State University, East Lansing, MI (United States)

    2005-09-01

    A series of beta decay experiments on nuclei near the Z=N line has been performed using the ISOL technique at the IGISOL facility in Jyvaeskylae and at ISOLDE, CERN. The decay properties of these neutron-deficient nuclei are important in astrophysics as well as in the studies of isospin symmetry. (orig.)

  6. Prompt Beta Spectroscopy as a Diagnostic for Mix in Ignited NIF Capsules

    CERN Document Server

    Hayes, A C; Solem, J C; Bradley, P A; Rundberg, R S

    2004-01-01

    The National Ignition Facility (NIF) technology is designed to drive deuterium-tritium (DT) internal confinement fusion (ICF) targets to ignition using indirect radiation from laser beam energy captured in a hohlraum. Hydrodynamical instabilities at interfaces in the ICF capsule leading to mix between the DT fue l and the ablator shell material are of fundamental physical interest and can affect the performance characteristics of the capsule. In this Letter we describe new radiochemical diagnostics for mix processes in ICF capsules with plastic or Be (0.9%Cu) ablator shells. Reactions of high-energy tritons with shell material produce high-energy $\\beta$-emitters. We show that mix between the DT fuel and the shell material enhances high-energy prompt beta emission from these reactions by more than an order of magnitude over that expected in the absence of mix.

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

    Science.gov (United States)

    Lioliou, G.; Barnett, A. M.

    2016-11-01

    Results characterizing GaAs p+-i-n+ mesa photodiodes with a 10 μm i layer for their spectral response under illumination of X-rays and beta particles are presented. A total of 22 devices, having diameters of 200 μm and 400 μm, were electrically characterized at room temperature. All devices showed comparable characteristics with a measured leakage current ranging from 4 nA/cm2 to 67 nA/cm2 at an internal electric field of 50 kV/cm. Their unintentionally doped i layers were found to be almost fully depleted at 0 V due to their low doping density. 55Fe X-ray spectra were obtained using one 200 μm diameter device and one 400 μm diameter device. The best energy resolution (FWHM at 5.9 keV) achieved was 625 eV using the 200 μm and 740 eV using the 400 μm diameter device, respectively. Noise analysis showed that the limiting factor for the energy resolution of the system was the dielectric noise; if this noise was eliminated by better design of the front end of the readout electronics, the achievable resolution would be 250 eV. 63Ni beta particle spectra obtained using the 200 μm diameter device showed the potential utility of these detectors for electron and beta particle detection. The development of semiconductor electron spectrometers is important particularly for space plasma physics; such devices may find use in future space missions to study the plasma environment of Jupiter and Europa and the predicted electron impact excitation of water vapor plumes from Europa hypothesized as a result of recent Hubble Space Telescope (HST) UV observations.

  8. Encapsulation of Prodan in beta-cyclodextrin environments: A critical study via electronic spectroscopy and molecular mechanics

    Science.gov (United States)

    Banerjee, Anwesha; Sengupta, Bidisa; Chaudhuri, Sudip; Basu, Kaushik; Sengupta, Pradeep K.

    2006-08-01

    We present a detailed study on the binding of the naphthalene based fluorescence probe Prodan with two cyclic oligosachharides namely, natural beta-cyclodextrin (β-CD) and its synthetic derivative, succinyl-2-hydroxypropyl beta-cyclodextrin (SHPβ-CD) using electronic absorption and fluorescence spectroscopy along with theoretical techniques. The encapsulation of Prodan inside the β-CD cavities leads to pronounced changes in its emission characteristics, including dramatic blue shifts (27 nm in 10 mM SHPβ-CD and 19 nm in 10 mM β-CD) in the emission maximum accompanied by increase in the emission yield, fluorescence anisotropy and lifetime values. Detailed analyses of the fluorescence along with relevant absorption spectroscopic data indicate that Prodan readily enters the doughnut-shaped hydrophobic cavities of the β-CDs and forms 1:1 inclusion complexes, the binding affinity being significantly higher in case of SHPβ-CD. Furthermore, docking studies performed via molecular mechanics methods (MM+) indicate that the dimethylamino group of Prodan is most likely to be oriented towards the wider rim of the cyclodextrin cavity. Quantum mechanical calculations reveal that incorporation of Prodan into the β-CD cavities, results in the formation of a N-TICT (dimethylamino twisted intramolecular charge transfer) state.

  9. A kinetic study of electrochemical lithium insertion in nanosized rutile {beta}-MnO{sub 2} by impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bach, S., E-mail: bach@glvt-cnrs.fr [Institut de Chimie et des Materiaux Paris Est, GESMAT, UMR 7182 CNRS-Universite Paris XII, 2 rue Henri Dunant 94320 Thiais (France); Universite d' Evry Val d' Essonne, Bd F.Mitterrand, Departement Chimie, 91025 Evry Cedex (France); Pereira-Ramos, J.P. [Institut de Chimie et des Materiaux Paris Est, GESMAT, UMR 7182 CNRS-Universite Paris XII, 2 rue Henri Dunant 94320 Thiais (France); Willmann, P. [Centre National d' Etudes Spatiales, 118 avenue Edouard Belin, 31401 Toulouse Cedex 9 (France)

    2011-11-30

    The kinetics of the electrochemical lithium insertion reaction in nano-sized rutile {beta}-MnO{sub 2} has been investigated using ac impedance spectroscopy. The experimental kinetic data are obtained for a rutile compound synthesized by ball-milling the powder produced from the heat treatment of manganese nitrate salts. The results are discussed as a function of the Li content for 0 < x < 0.6 and the number of cycles in the 4.1-2 V window. From a comparison with data obtained on the micro-sized oxide, an improved kinetics is found with D{sub Li} values for the apparent chemical diffusion coefficient of lithium much higher by one order of magnitude than in microsized oxide. Impedance behaviour of the ball-milled rutile {beta}-MnO{sub 2}vs cycles demonstrates a new system takes place from the second cycle, characterized by a significant improvement of Li diffusion by a factor 5 and a cathode impedance which decreases by a factor 2, remaining thereafter unchanged during cycling.

  10. Properties of the open cluster Tombaugh 1 from high resolution spectroscopy and uvbyCaH$\\beta$ photometry

    CERN Document Server

    Silva, João V Sales; Anthony-Twarog, Barbara J; Bidin, Christian Moni; Costa, Edgardo; Twarog, Bruce A

    2015-01-01

    Open clusters can be the key to deepen our knowledge on various issues involving the structure and evolution of the Galactic disk and details of stellar evolution because a cluster's properties are applicable to all its members. However the number of open clusters with detailed analysis from high resolution spectroscopy and/or precision photometry imposes severe limitation on studies of these objects. To expand the number of open clusters with well-defined chemical abundances and fundamental parameters, we investigate the poorly studied, anticenter open cluster Tombaugh 1. Using precision uvbyCaH$\\beta$ photometry and high resolution spectroscopy, we derive the cluster's properties and, for the first time, present detailed abundance analysis of 10 potential cluster stars. Using radial position from the cluster center and multiple color indices, we have isolated a sample of unevolved probable, single-star members of Tombaugh 1. The weighted photometric metallicity from $m_1$ and $hk$ is [Fe/H] = -0.10 $\\pm$ 0....

  11. High-resolution metallic magnetic calorimeters for {beta}-spectroscopy on {sup 187}rhenium and position resolved X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Porst, Jan-Patrick

    2011-02-01

    This thesis describes the development of metallic magnetic calorimeters (MMCs) for high resolution spectroscopy. MMCs are energy dispersive particle detectors based on the calorimetric principle which are typically operated at temperatures below 100 mK. The detectors make use of a paramagnetic temperature sensor to transform the temperature rise upon the absorption of a particle in the detector into a measurable magnetic flux change in a dc-SQUID. The application of MMCs for neutrino mass measurements and their advantages with respect to other approaches are discussed. In view of this application the development of an MMC optimized for {beta}-endpoint spectroscopy on {sup 187}rhenium is presented. A fully micro-fabricated X-ray detector is characterized and performs close to design values. Furthermore, a new technique to more efficiently couple rhenium absorbers mechanically and thermally to the sensor was developed and successfully tested. By employing a metallic contact, signal rise times faster than 5 {mu}s could be observed with superconducting rhenium absorbers. In addition to the single pixel detectors, an alternative approach of reading out multiple pixels was developed in this work, too. Here, the individual absorbers have a different thermal coupling to only one temperature sensor resulting in a distribution of different pulse shapes. Straightforward position discrimination by means of rise time analysis is demonstrated for a four pixel MMC and a thermal model of the detector is provided. Unprecedented so far, an energy resolution of less than {delta}E{sub FWHM}<5 eV for 5.9 keV X-rays was achieved across all absorbers. (orig.)

  12. Anisotropic superconductivity in {beta}-(BDA-TTP){sub 2}SbF{sub 6}: STM spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, K. [Department of Physics, Hokkaido University, Sapporo 060-0810 (Japan)], E-mail: knmr@phys.sci.hokudai.ac.jp; Muraoka, R.; Matsunaga, N. [Department of Physics, Hokkaido University, Sapporo 060-0810 (Japan); Ichimura, K. [Division of Applied Physics, Hokkaido University, Sapporo 060-8628 (Japan); Yamada, J. [Division of Material Science, University of Hyogo, Hyogo 678-1297 (Japan)

    2009-03-01

    We have investigated the gap symmetry in the superconducting phase of {beta}-(BDA-TTP){sub 2}SbF{sub 6} with use of the scanning tunneling microscope (STM). The tunneling spectra obtained on the conducting surface show a clear superconducting gap structure. Its functional form is of V-shaped similarly to {kappa}-(BEDT-TTF){sub 2}X and suggests the anisotropic superconducting gap with line nodes. For lateral surfaces the shape of tunneling spectra varies from the U-shape with relatively large gap to the V-shape with small gap depending on the tunneling direction alternately twice between directional angle 0 and {pi}. From the analysis of conductance curve taking the k dependence of the tunneling probability into account, it is found that the gap has maximum near the a* and c* axes and the nodes appear along near a*+c* and the a-c* directions. These indicate that the d{sub x{sup 2}-y{sup 2}} like superconducting pair is formed in this system as the case of {kappa}-(BEDT-TTF){sub 2}X. This node direction is consistent with the theoretical prediction based on the spin fluctuation mechanism. However, the zero-bias conductance peak has not been observed yet.

  13. Isomer and beta decay spectroscopy in the 132Sn region with EURICA

    International Nuclear Information System (INIS)

    The first EURICA campaign with high intensity Uranium beams took place at RIKEN in November/December 2012. Within this campaign experiment NP1112- RIBF85 was performed dedicated to the study of the isomeric and beta decays of neutron-rich Cd, In, Sn and Sb isotopes towards and beyond the N=82 neutron shell closure. In this contribution we present a first status report of the analysis of the extensive data set obtained in this experiment. Delayed γ rays were observed in coincidence with 136,138Sn and these constitute the first observation of the decay of excited states in these very neutron-rich, semi-magic nuclei. We found that the energies of the 2+, 4+ and 6+ levels remain fairly constant as the number of neutrons increases from N=84 to N=88. This agrees with the predictions of shell-model calculations performed using state-of-the-art interactions. In contrast calculations performed using empirical interactions (SMPN) deviate from the experimental data, despite the simple nature of these nuclei

  14. Cu K-edge X-ray Absorption Spectroscopy Reveals Differential Copper Coordimation Within Amyloid-beta Oligomers Compared to Amyloid-beta Monomers

    Energy Technology Data Exchange (ETDEWEB)

    J Shearer; P Callan; T Tran; V Szalai

    2011-12-31

    The fatal neurodegenerative disorder Alzheimer's disease (AD) has been linked to the formation of soluble neurotoxic oligomers of amyloid-{beta} (A{beta}) peptides. These peptides have high affinities for copper cations. Despite their potential importance in AD neurodegeneration few studies have focused on probing the Cu{sup 2+/1+} coordination environment within A{beta} oligomers. Herein we present a Cu K-edge X-ray absorption spectroscopic study probing the copper-coordination environment within oligomers of A{beta}(42) (sequence: DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIA). We find that the Cu{sup 2+} cation is contained within a square planar mixed N/O ligand environment within A{beta}(42) oligomers, which is similar to the copper coordination environment of the monomeric forms of {l_brace}Cu{sup II}A{beta}(40){r_brace} and {l_brace}Cu{sup II}A{beta}(16){r_brace}. Reduction of the Cu{sup 2+} cation within the A{beta}(42) oligomers to Cu{sup 1+} yields a highly dioxygen sensitive copper-species that contains Cu{sup 1+} in a tetrahedral coordination geometry. This can be contrasted with monomers of {l_brace}Cu{sup I}A{beta}(40){r_brace} and {l_brace}Cu{sup I}A{beta}(16){r_brace}, which contain copper in a dioxygen inert linear bis-histidine ligand environment [Shearer and Szalai, J. Am. Chem. Soc., 2008, 130, 17826]. The biological implications of these findings are discussed.

  15. Inclusion complexes of cypermethrin and permethrin with monochlorotriazinyl-beta-cyclodextrin: a combined spectroscopy, TG/DSC and DFT study.

    Science.gov (United States)

    Yao, Qi; You, Bin; Zhou, Shuli; Chen, Meng; Wang, Yujiao; Li, Wei

    2014-01-01

    The suitable size hydrophobic cavity and monochlorotriazinyl group as a reactive anchor make MCT-β-CD to be widely used in fabric finishing. In this paper, the inclusion complexes of monochlorotriazinyl-beta-cyclodextrin (MCT-β-CD) with cypermethrin (CYPERM) and permethrin (PERM) are synthesized and analyzed by TG/DSC, FT-IR and Raman spectroscopy. TG/DSC reveals that the decomposed temperatures of inclusion complexes are lower by 25-30 °C than that of physical mixtures. DFT calculations in conjunction with FT-IR and Raman spectral analyses are used to study the structures of MCT-β-CD and their inclusion complexes. Four isomers of trisubstituted MCT-β-CD are designed and DFT calculations reveal that 1,3,5-trisubstituted MCT-β-CD has the lowest energy and can be considered as main component of MCT-β-CD. The ground-state geometries, vibrational wavenumbers, IR and Raman intensities of MCT-β-CD and their inclusion complexes were calculated at B3LYP/6-31G (d) level of theory. Upon examining the optimized geometry of inclusion complex, we find that the CYPERM and PERM are inserted into the toroid of MCT-β-CD from the larger opening. The band at 1646 cm(-1) in IR and at 1668 cm(-1) in Raman spectrum reveals that monochloroazinyl group of MCT-β-CD exists in ketone form but not in anion form. The noticeable IR and Raman shift of phenyl reveals that these two benzene rings of CYPERM and PERM stays inside the cavity of MCT-β-CD and has weak interaction with MCT-β-CD. This spectroscopy conclusion is consistent with theoretical predicted structure.

  16. Probing the Kinetic Anabolism of Poly-Beta-Hydroxybutyrate in Cupriavidus necator H16 Using Single-Cell Raman Spectroscopy.

    Science.gov (United States)

    Tao, Zhanhua; Peng, Lixin; Zhang, Pengfei; Li, Yong-Qing; Wang, Guiwen

    2016-01-01

    Poly-beta-hydroxybutyrate (PHB) can be formed in large amounts in Cupriavidus necator and is important for the industrial production of biodegradable plastics. In this investigation, laser tweezers Raman spectroscopy (LTRS) was used to characterize dynamic changes in PHB content-as well as in the contents of other common biomolecule-in C. necator during batch growth at both the population and single-cell levels. PHB accumulation began in the early stages of bacterial growth, and the maximum PHB production rate occurred in the early and middle exponential phases. The active biosynthesis of DNA, RNA, and proteins occurred in the lag and early exponential phases, whereas the levels of these molecules decreased continuously during the remaining fermentation process until the minimum values were reached. The PHB content inside single cells was relatively homogenous in the middle stage of fermentation; during the late growth stage, the variation in PHB levels between cells increased. In addition, bacterial cells in various growth phases could be clearly discriminated when principle component analysis was performed on the spectral data. These results suggest that LTRS is a valuable single-cell analysis tool that can provide more comprehensive information about the physiological state of a growing microbial population. PMID:27509509

  17. Probing the Kinetic Anabolism of Poly-Beta-Hydroxybutyrate in Cupriavidus necator H16 Using Single-Cell Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    Zhanhua Tao

    2016-08-01

    Full Text Available Poly-beta-hydroxybutyrate (PHB can be formed in large amounts in Cupriavidus necator and is important for the industrial production of biodegradable plastics. In this investigation, laser tweezers Raman spectroscopy (LTRS was used to characterize dynamic changes in PHB content—as well as in the contents of other common biomolecule—in C. necator during batch growth at both the population and single-cell levels. PHB accumulation began in the early stages of bacterial growth, and the maximum PHB production rate occurred in the early and middle exponential phases. The active biosynthesis of DNA, RNA, and proteins occurred in the lag and early exponential phases, whereas the levels of these molecules decreased continuously during the remaining fermentation process until the minimum values were reached. The PHB content inside single cells was relatively homogenous in the middle stage of fermentation; during the late growth stage, the variation in PHB levels between cells increased. In addition, bacterial cells in various growth phases could be clearly discriminated when principle component analysis was performed on the spectral data. These results suggest that LTRS is a valuable single-cell analysis tool that can provide more comprehensive information about the physiological state of a growing microbial population.

  18. Harmonic force spectroscopy reveals a force-velocity curve from a single human beta cardiac myosin motor

    Science.gov (United States)

    Sung, Jongmin; Nag, Suman; Vestergaard, Christian; Mortensen, Kim; Flyvbjerg, Henrik; Spudich, James

    2014-03-01

    A muscle contracts rapidly under low load, but slowly under high load. Its molecular mechanisms remain to be elucidated, however. During contraction, myosins in thick filaments interact with actin in thin filaments in the sarcomere, cycling between a strongly bound (force producing) state and a weakly bound (relaxed) state. Huxley et al. have previously proposed that the transition from the strong to the weak interaction can be modulated by a load. We use a new method we call ``harmonic force spectroscopy'' to extract a load-velocity curve from a single human beta cardiac myosin II motor. With a dual-beam optical trap, we hold an actin dumbbell over a myosin molecule anchored to the microscope stage that oscillates sinusoidally. Upon binding, the motor experiences an oscillatory load with a mean that is directed forward or backward, depending on binding location We find that the bound time at saturating [ATP] is exponentially correlated with the mean load, which is explained by Arrhenius transition theory. With a stroke size measurement, we obtained a load-velocity curve from a single myosin. We compare the curves for wild-type motors with mutants that cause hypertrophic cardiomyopathies, to understand the effects on the contractile cycle

  19. Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Hal

    1968-01-01

    This booklet discusses spectroscopy, the study of absorption of radiation by matter, including X-ray, gamma-ray, microwave, mass spectroscopy, as well as others. Spectroscopy has produced more fundamental information to the study of the detailed structure of matter than any other tools.

  20. Spectroscopy

    CERN Document Server

    Walker, S

    1976-01-01

    The three volumes of Spectroscopy constitute the one comprehensive text available on the principles, practice and applications of spectroscopy. By giving full accounts of those spectroscopic techniques only recently introduced into student courses - such as Mössbauer spectroscopy and photoelectron spectroscopy - in addition to those techniques long recognised as being essential in chemistry teaching - sucha as e.s.r. and infrared spectroscopy - the book caters for the complete requirements of undergraduate students and at the same time provides a sound introduction to special topics for graduate students.

  1. $\\beta$3$p$-spectroscopy and proton-$\\gamma$ width determination in the decay of $^{31}$Ar

    CERN Multimedia

    We propose to perform a detailed study of the $\\beta$-decay of the dripline nucleus $^{31}$Ar. This will allow a detailed study of the $\\beta$-delayed 3$p$-decay as well as provide important information on the resonances of $^{30}$S and $^{29}$P, in particular the ratio between the $p$- and $\\gamma$- partial widths relevant for astrophysics.

  2. Primary structure determination of five sialylated oligosaccharides derived from bronchial mucus glycoproteins of patients suffering from cystic fibrosis. The occurrence of the NeuAc alpha(2----3)Gal beta(1----4)[Fuc alpha(1----3)] GlcNAc beta(1----.) structural element revealed by 500-MHz 1H NMR spectroscopy.

    Science.gov (United States)

    Lamblin, G; Boersma, A; Klein, A; Roussel, P; van Halbeek, H; Vliegenthart, J F

    1984-07-25

    The structure of sialylated carbohydrate units of bronchial mucins obtained from cystic fibrosis patients was investigated by 500-MHz 1H NMR spectroscopy in conjunction with sugar analysis. After subjecting the mucins to alkaline borohydride degradation, sialylated oligosaccharide-alditols were isolated by anion-exchange chromatography and fractionated by high performance liquid chromatography. Five compounds could be obtained in a rather pure state; their structures were established as the following: A-1, NeuAc alpha(2----3)Gal beta(1----4) [Fuc alpha(1----3)]GlcNAc beta(1----3)Gal-NAc-ol; A-2, NeuAc alpha(2----3)Gal beta(1----4)GlcNAc beta(1----6)-[GlcNAc beta (1----3)]GalNAc-o1; A-3, NeuAc alpha(2----3)Gal beta-(1----4)[Fuc alpha(1----3)]GlcNAc beta(1----3)Gal beta(1----3) GalNAc-o1; A-4, NeuAc alpha(2----3)Gal beta(1----4)[Fuc alpha(1----3)]Glc-NAc NAc beta(1----6)[GlcNAc beta(1----3)]GalNAc-o1; A-6,NeuAc alpha-(2----3) Gal beta(1----4)[Fuc alpha(1----3)]GlcNAc beta(1----6)[Gal beta-(1----4) GlcNAc beta(1----3)]GalNAc-o1. The simultaneous presence of sialic acid in alpha(2----3)-linkage to Gal and fucose in alpha(1----3)-linkage to GlcNAc of the same N-acetyllactosamine unit could be adequately proved by high resolution 1H NMR spectroscopy. This sequence constitutes a novel structural element for mucins.

  3. Primary structure determination of five sialylated oligosaccharides derived from bronchial mucus glycoproteins of patients suffering from cystic fibrosis. The occurrence of the NeuAc alpha(2----3)Gal beta(1----4)[Fuc alpha(1----3)] GlcNAc beta(1----.) structural element revealed by 500-MHz 1H NMR spectroscopy.

    Science.gov (United States)

    Lamblin, G; Boersma, A; Klein, A; Roussel, P; van Halbeek, H; Vliegenthart, J F

    1984-07-25

    The structure of sialylated carbohydrate units of bronchial mucins obtained from cystic fibrosis patients was investigated by 500-MHz 1H NMR spectroscopy in conjunction with sugar analysis. After subjecting the mucins to alkaline borohydride degradation, sialylated oligosaccharide-alditols were isolated by anion-exchange chromatography and fractionated by high performance liquid chromatography. Five compounds could be obtained in a rather pure state; their structures were established as the following: A-1, NeuAc alpha(2----3)Gal beta(1----4) [Fuc alpha(1----3)]GlcNAc beta(1----3)Gal-NAc-ol; A-2, NeuAc alpha(2----3)Gal beta(1----4)GlcNAc beta(1----6)-[GlcNAc beta (1----3)]GalNAc-o1; A-3, NeuAc alpha(2----3)Gal beta-(1----4)[Fuc alpha(1----3)]GlcNAc beta(1----3)Gal beta(1----3) GalNAc-o1; A-4, NeuAc alpha(2----3)Gal beta(1----4)[Fuc alpha(1----3)]Glc-NAc NAc beta(1----6)[GlcNAc beta(1----3)]GalNAc-o1; A-6,NeuAc alpha-(2----3) Gal beta(1----4)[Fuc alpha(1----3)]GlcNAc beta(1----6)[Gal beta-(1----4) GlcNAc beta(1----3)]GalNAc-o1. The simultaneous presence of sialic acid in alpha(2----3)-linkage to Gal and fucose in alpha(1----3)-linkage to GlcNAc of the same N-acetyllactosamine unit could be adequately proved by high resolution 1H NMR spectroscopy. This sequence constitutes a novel structural element for mucins. PMID:6746638

  4. EPR spectroscopy and beta-counting measurement of tooth enamel and dentine samples from population of techa river region in South Ural

    International Nuclear Information System (INIS)

    Calcified tooth tissue samples (enamel, root and crown dentine) collected from a population of Techa riverside exposed to radiation due to wastes of the nuclear weapon plant in South Ural, were investigated using absorbed dose determination by the electron paramagnetic resonance spectroscopy (EPR-dosimetry) and beta counting methods. High correlation between experimental doses and beta activities was observed in the same tissues and poor correlation was observed between different tissues of the same teeth. The results of EPR-dosimetry are analyzed with the use of a model of dose formation in teeth due to irradiation by 90Sr incorporated in tooth tissues taking into account biological elimination of 9OSr in tissues and fading of the EPR -signal caused by elimination of radiation-induced paramagnetic centers. (author)

  5. Spectroscopy

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules.......This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules....

  6. Hith resolution {beta}-spectroscopy of the isotope {sup 36}Cl using magnetic calorimeters; Entwicklung magnetischer Mikrokalorimeter fuer die hochaufloesende Spektroskopie des {beta}-Emitters {sup 36}Cl

    Energy Technology Data Exchange (ETDEWEB)

    Rotzinger, H.

    2006-12-13

    This thesis describes the development of a high resolution magnetic calorimeter for the detection of the {beta}-spectrum of the isotope {sup 36}Cl with endpoint energy of 709.6 keV. The temperature rise of a metallic paramagnetic sensor due to an energy deposition is sensed by measuring its magnetization using a sensitive DC-SQUID magnetometer. For a high detection efficiency an 4{pi} gold absorber was used. The heat capacity and the geometry of the absorber is optimally matched by a flat sensor and an optimized meander shaped readout coil. The fabrication of the superconducting structures and the detector setup are described. In addition, the relevant noise sources, the energy resolution and the quantum efficiency are discussed. A measured {sup 36}Cl-spectrum with an energy resolution of {delta}E{sub FWHM}=750 eV is presented and compared with existing experimental and theoretical data. (orig.)

  7. Cross-strand coupling of a beta-hairpin peptide stabilized with an Aib-Gly turn studied using isotope-edited IR spectroscopy.

    Science.gov (United States)

    Huang, Rong; Setnicka, Vladimir; Etienne, Marcus A; Kim, Joohyun; Kubelka, Jan; Hammer, Robert P; Keiderling, Timothy A

    2007-11-01

    Isotope-edited IR spectroscopy was used to study a series of singly and doubly 13C=O-labeled beta-hairpin peptides stabilized by an Aib-Gly turn sequence. The double-labeled peptides have amide I' IR spectra that show different degrees of vibrational coupling between the 13C-labeled amides due to variations in the local geometry of the peptide structure. The single-labeled peptides provide controls to determine frequencies characteristic of the diagonal force field (FF) contributions at each position for the uncoupled 13C=O modes. Separation of diagonal FF and coupling effects on the spectra are used to explain the cross-strand labeled spectral patterns. DFT calculations based on an idealized model beta-hairpin peptide correctly predict the vibrational coupling patterns. Extending these model results by consideration of frayed ends and the hairpin conformational flexibility yields an alternate interpretation of details of the spectra. Temperature-dependent isotopically labeled IR spectra reveal differences in the thermal stabilities of the individual isotopically labeled sites. This is the first example of using an IR-based isotopic labeling technique to differentiate structural transitions at specific sites along the peptide backbone in model beta-hairpin peptides.

  8. Orbital parameters, masses and distance to beta Centauri determined with the Sydney University Stellar Interferometer and high-resolution spectroscopy

    NARCIS (Netherlands)

    Davis, J.; Mendez, A.; Seneta, E.B.; Tango, W.J.; Booth, A.J.; O'Byrne, J.W.; Thorvaldson, E.D.; Ausseloos, M.; Aerts, C.C.; Uytterhoeven, K.

    2005-01-01

    The bright southern binary star beta Centauri (HR5267) has been observed with the Sydney University Stellar Interferometer (SUSI) and spectroscopically with the European Southern Observatory Coude Auxiliary Telescope and Swiss Euler telescope at La Silla. The interferometric observations have confir

  9. Probing the Orientation and Conformation of alpha-Helix and beta-Strand Model Peptides on Self-Assembled Monolayers Using Sum Frequency Generation and NEXAFS Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Weidner, T.; Apte, J; Gamble, L; Castner, D

    2010-01-01

    The structure and orientation of amphiphilic {alpha}-helix and {beta}-strand model peptide films on self-assembled monolayers (SAMs) have been studied with sum frequency generation (SFG) vibrational spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The {alpha}-helix peptide is a 14-mer, and the {beta}-strand is a 15-mer of hydrophilic lysine and hydrophobic leucine residues with hydrophobic periodicities of 3.5 and 2, respectively. These periodicities result in the leucine side chains located on one side of the peptides and the lysine side chains on the other side. The SAMs were prepared from the assembly of either carboxylic acid- or methyl-terminated alkyl thiols onto gold surfaces. For SFG studies, the deuterated analog of the methyl SAM was used. SFG vibrational spectra in the C-H region of air-dried peptides films on both SAMs exhibit strong peaks near 2965, 2940, and 2875 cm{sup -1} related to ordered leucine side chains. The orientation of the leucine side chains was determined from the phase of these features relative to the nonresonant gold background. The relative phase for both the {alpha}-helix and {beta}-strand peptides showed that the leucine side chains were oriented away from the carboxylic acid SAM surface and oriented toward the methyl SAM surface. Amide I peaks observed near 1656 cm{sup -1} for the {alpha}-helix peptide confirm that the secondary structure is preserved on both SAMs. Strong linear dichroism related to the amide {pi}* orbital at 400.8 eV was observed in the nitrogen K-edge NEXAFS spectra for the adsorbed {beta}-strand peptides, suggesting that the peptide backbones are oriented parallel to the SAM surface with the side chains pointing toward or away from the interface. For the {alpha}-helix the dichroism of the amide {pi}* is significantly weaker, probably because of the broad distribution of amide bond orientations in the {alpha}-helix secondary structure.

  10. Characterization of the alpha and beta subunits of casein kinase 2 by far-UV CD spectroscopy

    DEFF Research Database (Denmark)

    Issinger, O G; Brockel, C; Boldyreff, B;

    1992-01-01

    Although Chou-Fasman calculations of the secondary structure of recombinant casein kinase 2 subunits alpha and beta suggest they have a similar overall conformation, circular dichroism (CD) studies show that substantial differences in the conformation of the two subunits exist. In addition......, comparison of the far-UV CD spectrum of reconstituted CK-2 with the spectra of the subunits indicates that conformational changes occur in the backbone region upon association. Such changes may explain the increased enzyme activity of the holoenzyme relative to that of the alpha subunit itself. In contrast......, no changes in the far-UV CD spectrum of the alpha subunit are observed in the presence of casein or the synthetic decapeptide substrate RRRDDDSDDD. Furthermore, the alpha-helical structure of the alpha subunit (but not the beta subunit) can be increased in the presence of stoichiometric amounts of heparin...

  11. $\\beta$-delayed neutron spectroscopy of $^{130-132}$ Cd isotopes with the ISOLDE decay station and the VANDLE array

    CERN Multimedia

    We propose to use the new ISOLDE decay station and the neutron detector VANDLE to measure the $\\beta$-delayed neutron emission of N=82-84 $^{130-132}$Cd isotopes. The large delayed neutron emission probability observed in a previous ISOLDE measurement is indicative of the Gamow-Teller transitions due to the decay of deep core neutrons. Core Gamow-Teller decay has been experimentally proven in the $^{78}$Ni region for the N>50 nuclei using the VANDLE array. The spectroscopic measurement of delayed neutron emission along the cadmium isotopic chain will allow us to track the evolution of the single particle states and the shell gap.

  12. A NIM (Nuclear Instrumentation Module) system conjugated with optional input for pHEMT amplifier for beta and gamma spectroscopy; Um sistema de modulos NIM conjugados com entrada opcional por amplificador pHEMT para espectroscopia beta e gama

    Energy Technology Data Exchange (ETDEWEB)

    Konrad, Barbara; Lüdke, Everton, E-mail: barbarakonradmev@gmail.com, E-mail: eludke@smail.ufsm.br [Universidade Federal de Santa Maria (LAE/UFSM), RS (Brazil). Lab. de Astrofisica e Eletronica

    2014-07-01

    This work presents a high speed NIM module (Nuclear Instrumentation Module) to detect radiation, gamma and muons, as part of a system for natural radiation monitoring and of extraterrestrial origin. The subsystem developed consists of a preamplifier and an integrated SCA (Single Channel Analyzer), including power supplies of ± 12 and ± 24V with derivations of +3.6 and ± 5V. The single channel analyzer board, consisting of discrete logic components, operating in window modes, normal and integral. The pulse shaping block is made up of two voltage comparators working at 120 MHz with a response time > 60 ns and a logic anticoincidence system. The preamplifier promotes a noise reduction and introduces the impedance matching between the output of anode / diode photomultiplier tubes (PMTs) and subsequent equipment, providing an input impedance of 1MΩ and output impedance of 40 to 140Ω. The shaper amplifier is non-inverting and has variable input capacitance of 1000 pF. The upper and lower thresholds of the SCA are adjustable from 0 to ± 10V, and the equipment is compatible with various types of detectors, like PMTs coupled to sodium iodide crystals. For use with liquid scintillators and photodiodes with crystals (CsI: Tl) is proposed to include a preamplifier circuit pHEMT (pseudomorphic High Electron Mobility Transistor) integrated. Yet, the system presents the possibility of applications for various purposes of gamma spectroscopy and automatic detection of events producing of beta particles.

  13. Chandra spectroscopy of the hot star beta Crucis and the discovery of a pre-main-sequence companion

    CERN Document Server

    Cohen, David H; Gagné, Marc; Jensen, Eric L N; Miller, Nathan A

    2008-01-01

    In order to test the O star wind-shock scenario for X-ray production in less luminous stars with weaker winds, we made a pointed 74 ks observation of the nearby early B giant, beta Cru (B0.5 III), with the Chandra HETGS. We find that the X-ray spectrum is quite soft, with a dominant thermal component near 3 million K, and that the emission lines are resolved but quite narrow, with half-widths of 150 km/s. The forbidden-to-intercombination line ratios of Ne IX and Mg XI indicate that the hot plasma is distributed in the wind, rather than confined near the photosphere. It is difficult to understand the X-ray data in the context of the standard wind-shock paradigm for OB stars, primarily because of the narrow lines, but also because of the high X-ray production efficiency. A scenario in which the bulk of the outer wind is shock heated is broadly consistent with the data, but not very well motivated theoretically. It is possible that magnetic channeling could explain the X-ray properties, although no field has be...

  14. Orbital parameters, masses and distance to Beta Centauri determined with the Sydney University Stellar Interferometer and high resolution spectroscopy

    CERN Document Server

    Davis, J; Seneta, E B; Tango, W J; Booth, A J; O'Byrne, J W; Thorvaldson, E D; Ausseloos, M; Aerts, C; Uytterhoeven, K

    2004-01-01

    The bright southern binary star beta Centauri (HR 5267) has been observed with the Sydney University Stellar Interferometer (SUSI) and spectroscopically with the ESO CAT and Swiss Euler telescopes at La Silla. The interferometric observations have confirmed the binary nature of the primary component and have enabled the determination of the orbital parameters of the system. At the observing wavelength of 442 nm the two components of the binary system have a magnitude difference of 0.15. The combination of interferometric and spectroscopic data gives the following results: orbital period 357 days, semi-major axis 25.30 mas, inclination 67.4 degrees, eccentricity 0.821, distance 102.3 pc, primary and secondary masses M1 = M2 = 9.1 solar masses and absolute visual magnitudes of the primary and secondary M1V = -3.85 and M2V = -3.70. The high accuracy of the results offers a fruitful starting point for future asteroseismic modelling of the pulsating binary components.

  15. Amyloid beta oligomers induce neuronal elasticity changes in age-dependent manner: a force spectroscopy study on living hippocampal neurons.

    Science.gov (United States)

    Ungureanu, Andreea-Alexandra; Benilova, Iryna; Krylychkina, Olga; Braeken, Dries; De Strooper, Bart; Van Haesendonck, Chris; Dotti, Carlos G; Bartic, Carmen

    2016-01-01

    Small soluble species of amyloid-beta (Aβ) formed during early peptide aggregation stages are responsible for several neurotoxic mechanisms relevant to the pathology of Alzheimer's disease (AD), although their interaction with the neuronal membrane is not completely understood. This study quantifies the changes in the neuronal membrane elasticity induced by treatment with the two most common Aβ isoforms found in AD brains: Aβ40 and Aβ42. Using quantitative atomic force microscopy (AFM), we measured for the first time the static elastic modulus of living primary hippocampal neurons treated with pre-aggregated Aβ40 and Aβ42 soluble species. Our AFM results demonstrate changes in the elasticity of young, mature and aged neurons treated for a short time with the two Aβ species pre-aggregated for 2 hours. Neurons aging under stress conditions, showing aging hallmarks, are the most susceptible to amyloid binding and show the largest decrease in membrane stiffness upon Aβ treatment. Membrane stiffness defines the way in which cells respond to mechanical forces in their environment and has been shown to be important for processes such as gene expression, ion-channel gating and neurotransmitter vesicle transport. Thus, one can expect that changes in neuronal membrane elasticity might directly induce functional changes related to neurodegeneration.

  16. Evaluation of Hydrolytic Activity of Different Pectinases on Sugar Beet (Beta vulgaris Substrate Using FT-MIR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Adina CHIŞ

    2011-11-01

    Full Text Available The aim of this study was to evaluate the pectinase activity of two commercial enzymes Rohament PL and Rohapect 10L, using as substrate the sugar beet pulp, in different conditions. The method applied to check the rate of hydrolysis was Fourier-transformed infrared spectroscopy (FT-MIR, by recording the absorption spectra of different carbohydrates in the specific, MIR (middle IR spectral range (650-4000 cm-1. In order to calibrate the method, it has been recorded the FT-MIR spectrum of standard solutions of glucose, fructose, sucrose and galacturonic acid, at different concentrations, establishing also the peaks and the fingerprint regions specific to these compounds. Considering the specific peak intensities identified for glucose (at 1033 cm-1, fructose (at 1063 cm-1, sucrose (at 995 cm-1, and based on peak area for galacturonic acid (1500-700 cm-1, it has been calculated their concentrations, as a result of the Rohament PL or Rohapect 10L activity. Based on calibration curves for each sugar type, it has been calculated their concentrations in the sugar beet samples, and after their release by enzymatic treatment, establishing an optimized protocol of action for the two enzymes. Differences among the two enzymes activity were identified, specifically their optimum concentration and hydrolysis timing. FT-MIR spectroscopy proves to be an adequate method to evaluate the enzymatic activity of the different enzyme types, having certain advantages in comparison with the chromatographic methods, being a rapid, non-destructive method, at relatively low costs.

  17. Hydrogenation of the alpha,beta-Unsaturated Aldehydes Acrolein, Crotonaldehyde, and Prenal over Pt Single Crystals: A Kinetic and Sum-Frequency Generation Vibrational Spectroscopy Study

    Energy Technology Data Exchange (ETDEWEB)

    Kliewer, C.J.; Somorjai, G.A.

    2008-11-26

    Sum-frequency generation vibrational spectroscopy (SFG-VS) and kinetic measurements using gas chromatography have been used to study the surface reaction intermediates during the hydrogenation of three {alpha},{beta}-unsaturated aldehydes, acrolein, crotonaldehyde, and prenal, over Pt(111) at Torr pressures (1 Torr aldehyde, 100 Torr hydrogen) in the temperature range of 295K to 415K. SFG-VS data showed that acrolein has mixed adsorption species of {eta}{sub 2}-di-{sigma}(CC)-trans, {eta}{sub 2}-di-{sigma}(CC)-cis as well as highly coordinated {eta}{sub 3} or {eta}{sub 4} species. Crotonaldehyde adsorbed to Pt(111) as {eta}{sub 2} surface intermediates. SFG-VS during prenal hydrogenation also suggested the presence of the {eta}{sub 2} adsorption species, and became more highly coordinated as the temperature was raised to 415K, in agreement with its enhanced C=O hydrogenation. The effect of catalyst surface structure was clarified by carrying out the hydrogenation of crotonaldehyde over both Pt(111) and Pt(100) single crystals while acquiring the SFG-VS spectra in situ. Both the kinetics and SFG-VS showed little structure sensitivity. Pt(100) generated more decarbonylation 'cracking' product while Pt(111) had a higher selectivity for the formation of the desired unsaturated alcohol, crotylalcohol.

  18. Measurement of the Interaction Between Recombinant I-domain from Integrin alpha 2 beta 1 and a Triple Helical Collagen Peptide with the GFOGER Binding Motif Using Molecular Force Spectroscopy

    OpenAIRE

    Welland, Mark E.; Farndale, Richard W.; Dominique Bihan; Debdulal Roy; Simon J Attwood; Simpson, Anna M. C.; Hamaia, Samir W.

    2013-01-01

    The role of the collagen-platelet interaction is of crucial importance to the haemostatic response during both injury and pathogenesis of the blood vessel wall. Of particular interest is the high affinity interaction of the platelet transmembrane receptor, alpha 2 beta 1, responsible for firm attachment of platelets to collagen at and around injury sites. We employ single molecule force spectroscopy (SMFS) using the atomic force microscope (AFM) to study the interaction of the I-domain from i...

  19. Growth, shrinking, and breaking of pluronic micelles in the presence of drugs and/or beta-cyclodextrin, a study by small-angle neutron scattering and fluorescence spectroscopy.

    Science.gov (United States)

    Valero, Margarita; Dreiss, Cécile A

    2010-07-01

    The associative structures between F127 Pluronic micelles and four drugs, namely, lidocaine (LD), pentobarbital sodium salt (PB), sodium naproxen (NP), and sodium salicylate (SAL), were studied by small-angle neutron scattering (SANS). Different outcomes for the micellar aggregates are observed, which are dependent on the chemical nature of the drug and the presence of charge or otherwise: the micelles grow with LD, are hardly modified with PB, and decrease in size with both NP and SAL. The partition coefficient, determined by fluorescence spectroscopy, is directly correlated to the amount of charge, following NP approximately SAL inclusion complexes with heptakis(2,6-di-O-methyl) beta-cyclodextrin (hep2,6 beta-CD). Hep2,6 beta-CD, as shown in previous studies (Joseph, J.; Dreiss, C. A.; Cosgrove, T. Langmuir, 2008, 24, 10005-10010; Dreiss, C. A.; Nwabunwanne, E.; Liu, R.; Brooks, N. J. Soft Matter, 2009, 5, 1888-1896), is also able to form a complex with F127, resulting in micellar breakup. In the ternary mixtures, a fine balance of forces is involved, which results in drastic micellar changes, as observed from the SANS patterns. Depending on the ratio of drug, polymer, and hep2,6 beta-CD and the nature of the interactions (which is directly linked to the drug chemical structure), the presence of drug either hinders micellar breakup by beta-CD (at high enough concentration of LD or PB) or leads to micellar growth (NP). These effects are mainly attributed to a preferential drug/beta-CD interaction (except for PB), which, at least in the conditions studied here, explains the higher beta-CD concentration needed for micellar breakup to occur.

  20. Precision Fe K-Alpha and Fe K-Beta Line Spectroscopy of the Seyfert 1.9 Galaxy NGC 2992 with Suzaku

    Science.gov (United States)

    Yaqoob, Tahir; Murphy, Kendrah D.; Griffiths, Richard E.; Haba, Yoshito; Inoue, Hajime; Itoh, Takeshi; Kelley, Richard; Kokubun, Motohide; Markowitz, Alex; Mushotzky, Richard; Okajima, Takashi; Ptak, Andrew; Reeves, James; Selemitos, Peter J.; Takahashi, Tadayuki; Terashima, Yuichi

    2006-01-01

    We present detailed time-averaged X-ray spectroscopy in the 0.5-10 keV band of the Seyfert 1.9 galaxy NGC 2992 with the Suzaku X-ray Imaging Spectrometers (XIS). The source had a factor approximately 3 higher 2-10 keV flux (approximately 1.2 x l0(exp -11) erg per square cm per s) than the historical minimum and a factor approximately 7 less than the historical maximum. The XIS spectrum of NGC 2992 can be described by several components. There is a primary continuum, modeled as a power-law with a photon index of Gamma = 1.57(sup +0.06) (sup -0.03) that is obscured by a Compton-thin absorber with a column density of 8.01(sup +0.6) (sup -0.5)x l0 (exp 21) per square cm. . There is another, weaker, unabsorbed power-law component (modeled with the same slope as the primary), that is likely to be due to the primary continuum being electron-scattered into our line-of-sight by a region extended on a scale of hundreds of parsecs. We measure the Thomson depth of the scattering zone to be Tau = 0.072 +/- 0.021. An optically-thin thermal continuum emission component, which probably originates in the same extended region, is included in the model and yields a temperature and luminosity of KT = 0.656(sup +0.088) (sup -0.0.61) keV and approximately 1.2 +/- 0.4 x l0 (exp 40) erg per s respectively. We detect an Fe K emission complex which we model with broad and narrow lines and we show that the intensities of the two components are decoupled at a confidence level > 3 sigma. The broad Fe K alpha line has an equivalent width of 118(sup +32) (sup -61) eV and could originate in an accretion disk (with inclination angle greater than approximately 30 deg) around the putative central black hole. The narrow Fe K alpha line has an equivalent width of 1632(sup +47) (sup -26) eV and is unresolved (FWHM < 4630 km per s) and likely originates in distant matter. The absolute flux in the narrow line implies that the column density out of the line-of-sight could be much higher than measured in

  1. Reduced rate of adenosine triphosphate synthesis by in vivo 31P nuclear magnetic resonance spectroscopy and downregulation of PGC-1beta in distal skeletal muscle following burn.

    Science.gov (United States)

    Tzika, A Aria; Mintzopoulos, Dionyssios; Padfield, Katie; Wilhelmy, Julie; Mindrinos, Michael N; Yu, Hongue; Cao, Haihui; Zhang, Qunhao; Astrakas, Loukas G; Zhang, Jiangwen; Yu, Yong-Ming; Rahme, Laurence G; Tompkins, Ronald G

    2008-02-01

    Using a mouse model of burn trauma, we tested the hypothesis that severe burn trauma corresponding to 30% of total body surface area (TBSA) causes reduction in adenosine triphosphate (ATP) synthesis in distal skeletal muscle. We employed in vivo 31P nuclear magnetic resonance (NMR) in intact mice to assess the rate of ATP synthesis, and characterized the concomitant gene expression patterns in skeletal muscle in burned (30% TBSA) versus control mice. Our NMR results showed a significantly reduced rate of ATP synthesis and were complemented by genomic results showing downregulation of the ATP synthase mitochondrial F1 F0 complex and PGC-1beta gene expression. Our findings suggest that inflammation and muscle atrophy in burns are due to a reduced ATP synthesis rate that may be regulated upstream by PGC-1beta. These findings implicate mitochondrial dysfunction in distal skeletal muscle following burn injury. That PGC-1beta is a highly inducible factor in most tissues and responds to common calcium and cyclic adenosine monophosphate (cAMP) signaling pathways strongly suggests that it may be possible to develop drugs that can induce PGC-1beta.

  2. Micro-heterogeneity and micro-rheological properties of high-viscosity barley beta-glucan solutions studied by diffusion wave spectroscopy (DWS)

    Science.gov (United States)

    Soluble fiber ß-glucan is one of the key dietary material in healthy food products known for reducing serum cholesterol levels. The micro-structural heterogeneity and micro-rheology of high-viscosity barley ß-glucan solutions were investigated by the diffusion wave spectroscopy (DWS) technology. By ...

  3. Measurement of the Interaction Between Recombinant I-domain from Integrin alpha 2 beta 1 and a Triple Helical Collagen Peptide with the GFOGER Binding Motif Using Molecular Force Spectroscopy

    Directory of Open Access Journals (Sweden)

    Mark E. Welland

    2013-01-01

    Full Text Available The role of the collagen-platelet interaction is of crucial importance to the haemostatic response during both injury and pathogenesis of the blood vessel wall. Of particular interest is the high affinity interaction of the platelet transmembrane receptor, alpha 2 beta 1, responsible for firm attachment of platelets to collagen at and around injury sites. We employ single molecule force spectroscopy (SMFS using the atomic force microscope (AFM to study the interaction of the I-domain from integrin alpha 2 beta 1 with a synthetic collagen related triple-helical peptide containing the high-affinity integrin-binding GFOGER motif, and a control peptide lacking this sequence, referred to as GPP. By utilising synthetic peptides in this manner we are able to study at the molecular level subtleties that would otherwise be lost when considering cell-to-collagen matrix interactions using ensemble techniques. We demonstrate for the first time the complexity of this interaction as illustrated by the complex multi-peaked force spectra and confirm specificity using control blocking experiments. In addition we observe specific interaction of the GPP peptide sequence with the I-domain. We propose a model to explain these observations.

  4. Shape effects along the Z=82 line: study of the $\\beta$- decay of $^{188,190,192}$Pb using total absorption spectroscopy

    CERN Multimedia

    Caballero ontanaya, L; Garcia borge, M J; Malbrunot, S

    2002-01-01

    This proposal is aimed at the study of the $\\beta$- decay of the neutron-deficient $^{188,190,192}$Pb nuclei. The main motivation of the proposed experiment is to determine the Gamow-Teller strength distribution in the daughter nuclei using the Total Absorption Spectrometer "Lucrecia". Recent theoretical results show that from this measurement the shapes of the ground states of the decaying Pb nuclei can be inferred. This study offers an independent way to study the phenomenon of shape co-existence in a region of particular interest.

  5. Ultrafast relaxation kinetics of the dark S{sub 1} state in all-trans-{beta}-carotene explored by one- and two-photon pump-probe spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kosumi, Daisuke, E-mail: kosumi@sci.osaka-cu.ac.jp [Department of Physics, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai 980-8578 (Japan); Abe, Kenta; Karasawa, Hiroshi [Department of Physics, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai 980-8578 (Japan); Fujiwara, Masazumi [Department of Physics, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); Cogdell, Richard J. [Glasgow Biomedical Research Center, University of Glasgow, 120 University Place, Glasgow G12 8TA, Scotland (United Kingdom); Hashimoto, Hideki [Department of Physics, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585 (Japan); JST/CREST, 4-1-8 Hon-chou, Kawaguchi, Saitama 332-0012 (Japan); Yoshizawa, Masayuki [Department of Physics, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai 980-8578 (Japan); JST/CREST, 4-1-8 Hon-chou, Kawaguchi, Saitama 332-0012 (Japan)

    2010-07-19

    Femtosecond one- and two-photon pump-probe dispersive spectroscopic measurements have been applied to the investigation of the vibrational relaxation kinetics of the dark S{sub 1} (2{sup 1}A{sub g}{sup -}) state in {beta}-carotene, combining a higher sensitive detection system with tunable visible and infrared excitation pulses. The two-photon excitation measurements enable the preferential detection of the dark S{sub 1} state. The tunable infrared excitation pulses allowed selective excitation to a different vibrational level of S{sub 1}. The S{sub 1} dynamics at early delay times depend strongly on excitation energy. A dependence of the initial S{sub 1} dynamics on excitation energy is discussed in term of the vibrational relaxation of S{sub 1}.

  6. Study of the N=28 shell closure by one neutron transfer reaction: astrophysical application and {beta}-{gamma} spectroscopy of neutron rich nuclei around N=32/34 and N=40; Etude de la fermeture de couche N=28 autour du noyau {sub 18}{sup 46}Ar{sub 28} par reaction de transfert d'un neutron: application a l'astrophysique et Spectroscopie {beta}-{gamma} de noyaux riches en neutrons de N=32/34 et N=40

    Energy Technology Data Exchange (ETDEWEB)

    Gaudefroy, L

    2005-09-15

    The study of the N=28 shell closure has been presented as well as its astrophysical implications. Moreover the structure of neutron rich nuclei around N=32/34 and 40 was studied. The N=28 shell closure has been studied trough the one neutron transfer reaction on {sup 44,46}Ar nuclei. Excitation energies of states in {sup 45,47}Ar nuclei have been obtained, as well as their angular momenta and spectroscopic factors. These results were used to show that N=28 is still a good magic number in the argon isotopic chain. We interpreted the evolution of the spin-orbit partner gaps in terms of the tensor monopolar proton-neutron interaction. Thanks to this latter, we showed it is not necessary to summon up a reduction of the intensity of the spin-orbit force in order to explain this evolution in N=29 isotopes from calcium to argon chains. The neutron capture rates on {sup 44,46}Ar have been determined thanks to the results of the transfer reaction. Their influence on the nucleosynthesis of {sup 46,48}Ca was studied. We proposed stellar conditions to account for the abnormal isotopic ratio observed in the Allende meteorite concerning {sup 46,48}Ca isotopes. The beta decay and gamma spectroscopy of neutron rich nuclei in the scandium to cobalt region has been studied. We showed that beta decay process is dominated by the {nu}f{sub 5/2} {yields} {pi}f{sub 7/2} Gamow-Teller transition. Moreover, we demonstrated that the {nu}g{sub 9/2} hinders this process in the studied nuclei, and influences their structure, by implying the existence of isomers. Our results show that N=34 is not a magic number in the titanium chain and the superior ones. (author)

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    ) V-1 s(-1), which is considerably less than the FEM of alpha,omega-DH6T. To understand the reason for such poor macroscopic electrical properties, the conformation and the molecular packing of beta,beta'-DH6T were systematically studied by means of UV-vis spectroscopy, scanning electron microscopy...

  8. Binding capacity of a barley beta-D-glucan to the beta-glucan recognition molecule dectin-1.

    Science.gov (United States)

    Tada, Rui; Adachi, Yoshiyuki; Ishibashi, Ken-ichi; Tsubaki, Kazufumi; Ohno, Naohito

    2008-02-27

    To clarify whether barley beta-glucans exhibit their biological effects via binding to dectin-1, a pivotal receptor for beta-1,3-glucan, the structure of barley beta-glucan E70-S (BBG-70) was unambiguously investigated by NMR spectroscopy and studied for its binding capacity and specificity to dectin-1 by ELISA. NMR spectroscopy confirmed that BBG-70 contains two different linkage glucans, namely, alpha-glucan and beta-glucan, which are not covalently attached to one another. Beta-glucan within BBG-70 is a linear mixed-linkage beta-glucan composed of 1,3- and 1,4-beta-D-glucopyranose residues but does not contain the continuous 1,3-linkage. Competitive ELISA revealed that highly purified barley beta-glucan E70-S (pBBG-70) inhibits the binding of soluble dectin-1 to sonifilan (SPG), a beta-1,3-glucan, although at a concentration higher than that of SPG and laminarin. It was found that barley beta-glucan can be recognized by dectin-1, implying that barley beta-glucan might, at least in part, exhibit its biological effects via the recognition by dectin-1 of the ligand sugar structure, which may be formed by 1,3-beta- and 1,4-beta-glucosyl linkage. PMID:18205312

  9. NMR Spectroscopic Analysis on the Chiral Recognition of Noradrenaline by {beta}-Cyclodextrin ({beta}-CD) and Carboxymethyl- {beta}-cyclodextrin (CM- {beta}-CD)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Hoo; Yi, Dong Heui; Jung, Seun Ho [Konkuk University, Seoul (Korea, Republic of)

    2004-02-15

    {beta}-CD and CM-{beta}-CD as chiral NMR shift agents were used to resolve the enantiomers of noradrenaline (NA). The stoichiometry of each complex formed between the CDs and the enantiomers of NA was found to be 1 : 1 through the continuous variation plots. The binding constants (K) of the complexes were determined from 1H NMR titration curves. This result indicated that both {beta}-CD and CM-{beta}-CD formed the complexes with the S (+)-NA more preferentially than its R(.)-enantiomer. The K values for the complexes with {beta}-CD (KS(+) = 537 M{sup -1} and K{sub R}({sub -}) = 516 M{sup -1}) was larger than those with CM-{beta}-CD (K{sub S}({sub +}) = 435 M{sup -1} and K{sub R}({sub -}) = 313 M{sup -1}), however, enantioselectivity ({alpha}) of S({sub +})- and R(-)-NA to CM-{beta}-CD ({alpha} = 1.38) was larger than that to {beta}-CD ({alpha} = 1.04), indicating that CM-{beta}-CD was the better chiral NMR solvating agents for the recognition of the enantiomers of NA. Two dimensional rotating frame nuclear Overhauser enhancement spectroscopy (ROESY) experiments were also performed to explain the binding properties in terms of spatial fitting of the NA molecule into the macrocyclic cavities

  10. Radiation-induced polymerization of {beta}(+)-pinene and synthesis of optically active {beta}(+)/{beta}(-)pinene polymers and copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Cataldo, Franco, E-mail: franco.cataldo@fastwebnet.i [Lupi Chemical Research, Via Casilina 1626/A, 00133 Rome (Italy); Lilla, Edo; Ursini, Ornella [Institute of Chemical Methodologies, CNR, Via Salaria Km. 29300, Monterotondo Stazione 00016, Rome (Italy)

    2011-06-15

    Poly-{beta}(+)-pinene (pB(+)p) was synthesized with {gamma} irradiation of the monomer {beta}(+)-pinene in bulk under vacuum at 1181 kGy. Also scalemic mixtures of {beta}(+)-pinene and {beta}(-)-pinene were irradiated at 1181 kGy to obtain synthetic copolymers of pB(+)/B(-)p. For comparison also {beta}(-)-pinene was converted into poly-{beta}(-)-pinene (pB(-)p) under the identical conditions adopted for its enantiomer. Furthermore pB(+)p and pB(-)p were also synthesized by thermal processing under the action of a chemical free radical initiator. The optical rotatory dispersion (ORD) of all pBp resins synthesized were accurately studied in the spectral range comprised between 375 and 625 nm and a curious asymmetry in the ORD of pB(+)p versus the ORD of pB(-)p is reported. Furthermore, it is shown that (+)-p-menth-1-ene and (-)-p-menth-1-ene are useful as a model compounds for the pBp resins and for the explanation of the amplification of the optical activity of the {beta}(+)-pinene and {beta}(-)-pinene after their ring-opening polymerization to pB(+)p and pB(-)p. The pBp resins were studied also by FT-IR spectroscopy and by thermal analysis (TGA and DTG).

  11. BETA-S, Multi-Group Beta-Ray Spectra

    International Nuclear Information System (INIS)

    1 - Description of program or function: BETA-S calculates beta-decay source terms and energy spectra in multigroup format for time-dependent radionuclide inventories of actinides, fission products, and activation products. Multigroup spectra may be calculated in any arbitrary energy-group structure. The code also calculates the total beta energy release rate from the sum of the average beta-ray energies as determined from the spectral distributions. BETA-S also provides users with an option to determine principal beta-decaying radionuclides contributing to each energy group. The CCC-545/SCALE 4.3 (or SCALE4.2) code system must be installed on the computer before installing BETA-S, which requires the SCALE subroutine library and nuclide-inventory generation from the ORIGEN-S code. 2 - Methods:Well-established models for beta-energy distributions are used to explicitly represent allowed, and 1., 2. - and 3. -forbidden transition types. Forbidden non-unique transitions are assumed to have a spectral shape of allowed transitions. The multigroup energy spectra are calculated by numerically integrating the energy distribution functions using an adaptive Simpson's Rule algorithm. Nuclide inventories are obtained from a binary interface produced by the ORIGEN-S code. BETA-S calculates the spectra for all isotopes on the binary interface that have associated beta-decay transition data in the ENSDF-95 library, developed for the BETA-S code. This library was generated from ENSDF data and contains 715 materials, representing approximately 8500 individual beta transition branches. 3 - Restrictions on the complexity of the problem: The algorithms do not treat positron decay transitions or internal conversion electrons. The neglect of positron transitions in inconsequential for most applications involving aggregate fission products, since most of the decay modes are via electrons. The neglect of internal conversion electrons may impact on the accuracy of the spectrum in the low

  12. Ultrafast Unzipping of a Beta-Hairpin Peptide

    NARCIS (Netherlands)

    Zinth, W.; Schrader, T.E.; Schreier, W.J.; Koller, F.O.; Cordes, T.; Babitzki, G.; Denschlag, R.; Tavan, P.; Löweneck, M.; Dong, Shou-Liang; Moroder, L.; Renner, C.; Corkum, Paul; Jonas, David M.; Miller, R.J. Dwayne; Weiner, Andrew M.

    2007-01-01

    Light induced switching of a beta-hairpin structure is investigated by femtosecond IR spectroscopy. While the unzipping process comprises ultrafast kinetics and is finished within 1 ns, the folding into the hairpin structure is a much slower process.

  13. Evidence for Novel [beta]-Sheet Structures in Iowa Mutant [beta]-Amyloid Fibrils

    Energy Technology Data Exchange (ETDEWEB)

    Tycko, Robert; Sciarretta, Kimberly L.; Orgel, Joseph P.R.O.; Meredith, Stephen C.; (IIT); (NIH); (UC)

    2009-07-24

    Asp23-to-Asn mutation within the coding sequence of {beta}-amyloid, called the Iowa mutation, is associated with early onset, familial Alzheimer's disease and cerebral amyloid angiopathy, in which patients develop neuritic plaques and massive vascular deposition predominantly of the mutant peptide. We examined the mutant peptide, D23N-A{beta}40, by electron microscopy, X-ray diffraction, and solid-state NMR spectroscopy. D23N-A{beta}40 forms fibrils considerably faster than the wild-type peptide (k = 3.77 x 10{sup -3} min{sup -1} and 1.07 x 10{sup -4} min{sup -1} for D23N-A{beta}40 and the wild-type peptide WT-A{beta}40, respectively) and without a lag phase. Electron microscopy shows that D23N-A{beta}40 forms fibrils with multiple morphologies. X-ray fiber diffraction shows a cross-{beta} pattern, with a sharp reflection at 4.7 {angstrom} and a broad reflection at 9.4 {angstrom}, which is notably smaller than the value for WT-A{beta}40 fibrils (10.4 {angstrom}). Solid-state NMR measurements indicate molecular level polymorphism of the fibrils, with only a minority of D23N-A{beta}40 fibrils containing the in-register, parallel {beta}-sheet structure commonly found in WT-A{beta}40 fibrils and most other amyloid fibrils. Antiparallel {beta}-sheet structures in the majority of fibrils are indicated by measurements of intermolecular distances through 13C-13C and 15N-13C dipole-dipole couplings. An intriguing possibility exists that there is a relationship between the aberrant structure of D23N-A{beta}40 fibrils and the unusual vasculotropic clinical picture in these patients.

  14. Beta decay of highly charged ions

    International Nuclear Information System (INIS)

    Ion storage rings and ion traps provide the very first opportunity to address nuclear beta decay under conditions prevailing in hot stellar plasmas during nucleosynthesis, i.e. at high atomic charge states. Experiments are summarized that were performed in this field during the last decade at the ion storage-cooler ring ESR in Darmstadt. Special emphasis is given to the first observation of bound-state beta decay, where the created electron remains bound in an inner orbital of the daughter atom. The impact of this specific 'stellar' decay mode for s-process nucleosynthesis as well as for nuclear 'eon clocks' is outlined. Finally, a new technique, single-ion decay spectroscopy, is presented, where one observes two-body beta decay characteristics (i.e. orbital electron capture or bound-state beta decay) of highly charged, single ions for well-defined nuclear and atomic quantum states of both the mother - and the daughter - ion.

  15. Levered and unlevered Beta

    OpenAIRE

    Fernandez, Pablo

    2003-01-01

    We prove that in a world without leverage cost the relationship between the levered beta ( L) and the unlevered beta ( u) is the No-costs-of-leverage formula: L = u + ( u - d) D (1 - T) / E. We also analyze 6 alternative valuation theories proposed in the literature to estimate the relationship between the levered beta and the unlevered beta (Harris and Pringle (1985), Modigliani and Miller (1963), Damodaran (1994), Myers (1974), Miles and Ezzell (1980), and practitioners) and prove that all ...

  16. Realized Beta GARCH

    DEFF Research Database (Denmark)

    Hansen, Peter Reinhard; Lunde, Asger; Voev, Valeri Radkov

    2014-01-01

    as the beta. We apply the model to a large set of assets and find the conditional betas to be far more variable than usually found with rolling-window regressions based exclusively on daily returns. In the empirical part of the paper, we examine the cross-sectional as well as the time variation...... of the conditional beta series during the financial crises....

  17. Differences in the processes of beta-lactoglobulin cold and heat denaturations.

    OpenAIRE

    Griko YuV; Kutyshenko, V. P.

    1994-01-01

    The changes in beta-lactoglobulin upon cold and heat denaturation were studied by scanning calorimetry, CD, and NMR spectroscopy. It is shown that, in the presence of urea, these processes of beta-lactoglobulin denaturation below and above 308 K are accompanied by different structural and thermodynamic changes. Analysis of the NOE spectra of beta-lactoglobulin shows that changes in the spin diffusion of beta-lactoglobulin after disruption of the unique tertiary structure upon cold denaturatio...

  18. Design, synthesis, and evaluation of 2 beta-alkenyl penam sulfone acids as inhibitors of beta-lactamases.

    Science.gov (United States)

    Richter, H G; Angehrn, P; Hubschwerlen, C; Kania, M; Page, M G; Specklin, J L; Winkler, F K

    1996-09-13

    A general method for synthesis of 2 beta-alkenyl penam sulfones has been developed. The new compounds inhibited most of the common types of beta-lactamase. The level of activity depended very strongly on the nature of the substituent in the 2 beta-alkenyl group. The inhibited species formed with the beta-lactamase from Citrobacter freundii 1205 was sufficiently stable for X-ray crystallographic studies. These, together with UV absorption spectroscopy and studies of chemical degradation, suggested a novel reaction mechanism for the new inhibitors that might account for their broad spectrum of action. The (Z)-2 beta-acrylonitrile penam sulfone Ro 48-1220 was the most active inhibitor from this class of compound. The inhibitor enhanced the action of, for example, ceftriaxone against a broad selection of organisms producing beta-lactamases. The organisms included strains of Enterobacteriaceae that produce cephalosporinases, which is an exceptional activity for penam sulfones.

  19. Betting Against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model’s five central predictions: (1) Since constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for U.......S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return...... of the BAB factor is low; (4) Increased funding liquidity risk compresses betas toward one; (5) More constrained investors hold riskier assets....

  20. Betting against Beta

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Heje Pedersen, Lasse

    2014-01-01

    We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model's five central predictions: (1) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically...... for US equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures. (2) A betting against beta (BAB) factor, which is long leveraged low-beta assets and short high-beta assets, produces significant positive risk-adjusted returns. (3) When funding constraints tighten......, the return of the BAB factor is low. (4) Increased funding liquidity risk compresses betas toward one. (5) More constrained investors hold riskier assets....

  1. Roughing up Beta

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Li, Sophia Zhengzi; Todorov, Viktor

    Motivated by the implications from a stylized equilibrium pricing framework, we investigate empirically how individual equity prices respond to continuous, or \\smooth," and jumpy, or \\rough," market price moves, and how these different market price risks, or betas, are priced in the cross......-section of expected returns. Based on a novel highfrequency dataset of almost one-thousand individual stocks over two decades, we find that the two rough betas associated with intraday discontinuous and overnight returns entail significant risk premiums, while the intraday continuous beta is not priced in the cross......-section. An investment strategy that goes long stocks with high jump betas and short stocks with low jump betas produces significant average excess returns. These higher risk premiums for the discontinuous and overnight market betas remain significant after controlling for a long list of other firm characteristics...

  2. NMR study of the preparation of 6 {alpha}, 7 {beta}-dihydroxyvouacapan-17 beta-oic acid mannich base derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Flavio Jose Leite dos; Pilo-Veloso, Dorila [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Inst. de Ciencias Exatas. Dept. Quimica]. E-mail: dorila@zeus.qui.ufmg.br; Ferreira-Alves, Dalton L. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte (Brazil). Inst. de Ciencias Biologicas. Dept. de Farmacologia

    2007-07-01

    This work presents four new Mannich base compounds obtained by the Mannich reaction of a {delta}-keto-lactone derivative of 6{alpha}, 7{beta}-dihydroxyvouacapan- 17{beta}-oic acid, a furano diterpene isolated from the hexane extract of Pterodon polygalaeflorus Benth fruits, which shows anti-inflammatory and analgesic activities. The use of 1D and 2D NMR (COSY, DEPT-135, HMBC, HMQC) spectroscopy made it possible to characterize the new compounds. (author)

  3. Forward-Looking Betas

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

    -looking. This paper introduces a radically different approach to estimating market betas. Using the tools in Bakshi and Madan (2000) and Bakshi, Kapadia and Madan (2003) we employ the information embedded in the prices of individual stock options and index options to compute our forward-looking market beta...

  4. Double beta decay of 128Te and RIS

    International Nuclear Information System (INIS)

    The paper considers the use of Resonance Ionization Spectroscopy (RIS) in the determination of the electron neutrino mass via the double beta decay of 128Te. An outline is given of the theoretical background to the electron neutrino restmass, and the importance of the neutrino properties in Grand Unification Theories. The detection method for double beta decay is described; the discussion is restricted to tellurium ores and the decays 128Te → 128Xe, and 130Te → 130Xe. A consideration of existing data on double beta decay of 128Te indicates that most aspects of the detection could benefit from RIS. (U.K.)

  5. Terahertz spectroscopy

    DEFF Research Database (Denmark)

    Jepsen, Peter Uhd

    2009-01-01

    In this presentation I will review methods for spectroscopy in the THz range, with special emphasis on the practical implementation of the technique known ad THz time-domain spectroscopy (THz-TDS). THz-TDS has revived the old field of far-infrared spectroscopy, and enabled a wealth of new...... activities that promise commercial potential for spectroscopic applications in the THz range. This will be illustrated with examples of spectroscopy of liquids inside their bottles as well as sensitive, quantitative spectroscopy in waveguides....

  6. Application of resonance ionization spectroscopy in particle physics

    International Nuclear Information System (INIS)

    The use of resonance ionization spectroscopy in the measurement of the solar neutrino flux, baryon conservation and double beta decay in the search for fractional charge, superheavy ions and magnetic monopoles is discussed. (U.K.)

  7. Comparative study on the inclusion behavior between meso-tetrakis(4-N-ethylpyridiniurmyl)porphyrin and beta-cyclodextrin derivatives.

    Science.gov (United States)

    Xiliang, Guo; Shaomin, Shuang; Chuan, Dong; Feng, Feng; Wong, M S

    2005-01-14

    5,10,15,20-Tetrakis(4-N-ethylpyridiniurmyl)porphyrin (TEPyP) formed 1:1 stoichiometry inclusion complexes with beta-cyclodextrin (beta-CD) and its derivatives including hydroxypropyl-beta-cyclodextrin (HP-beta-CD), sulfobutylether-beta-cyclodextrin (SBE-beta-CD) in basic aqueous solution. The supramolecular system was investigated by the methods of fluorescence, UV-vis absorption spectroscopy, nuclear magnetic resonance (NMR) technique. The inclusion ability of cyclodextrins exhibited remarkable difference for beta-CD, HP-beta-CD and SBE-beta-CD. Association constants as high as K=1.1 x 10(4) M(-1) in the case of HP-beta-CD/TEPyP and 2.0 x 10(5) M(-1) in the case of SBE-beta-CD/TEPyP complexes were determined, whereas a lower value (K=550 M(-1)) was given in the case of beta-CD/TEPyP. The results showed that hydrogen bonding and charge attraction play important roles in the processes of host-guest interaction. The interaction mechanism of inclusion processes could be explained by the analysis of NMR spectroscopy. The supramolecular assembly was formed. beta-CD and HP-beta-CD approached from the primary face of cavities of CDs.

  8. Preparation and spectral investigation of inclusion complex of caffeic acid with hydroxypropyl-beta-cyclodextrin.

    Science.gov (United States)

    Zhang, Min; Li, Jinxia; Zhang, Liwei; Chao, Jianbin

    2009-01-01

    The inclusion complexation behavior of caffeic acid (CA) with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was studied by UV-vis, fluorescence spectroscopy and nuclear magnetic resonance spectroscopy (NMR). Experimental conditions including the concentration of HP-beta-CD and media acidity were investigated in detail. The result suggested HP-beta-CD was more suitable for including CA in acidity solution. The binding contants (K) of the inclusion complexes were determined by linear regression analysis and the inclusion ratio was found to be 1:1. The water solubility of CA was increased by inclusion with HP-beta-CD according to the phase-solubility diagram. The spatial configuration of complex has been proposed based on (1)H NMR and two-dimensional (2D) NMR, the result suggested that CA was entrapped inside the hydrophobic core of HP-beta-CD with the lipophilic aromatic ring and the portion of ethylene.

  9. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    Kai Zuber

    2012-10-01

    The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  10. Beta-carotene

    Science.gov (United States)

    ... chemotherapy for a blood cancer called lymphoblastic leukemia. Mental performance. Some evidence suggests that taking beta-carotene ... One is water-based, and the other is oil-based. Studies show that the water-based version ...

  11. [High beta tokamak research

    International Nuclear Information System (INIS)

    Our activities on High Beta Tokamak Research during the past 20 months of the present grant period can be divided into six areas: reconstruction and modeling of high beta equilibria in HBT; measurement and analysis of MHD instabilities observed in HBT; measurements of impurity transport; diagnostic development on HBT; numerical parameterization of the second stability regime; and conceptual design and assembly of HBT-EP. Each of these is described in some detail in the sections of this progress report

  12. {beta} - amyloid imaging probes

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2007-04-15

    Imaging distribution of {beta} - amyloid plaques in Alzheimer's disease is very important for early and accurate diagnosis. Early trial of the {beta} -amyloid plaques includes using radiolabeled peptides which can be only applied for peripheral {beta} - amyloid plaques due to limited penetration through the blood brain barrier (BBB). Congo red or Chrysamine G derivatives were labeled with Tc-99m for imaging {beta} - amyloid plaques of Alzheimer patient's brain without success due to problem with BBB penetration. Thioflavin T derivatives gave breakthrough for {beta} - amyloid imaging in vivo, and a benzothiazole derivative [C-11]6-OH-BTA-1 brought a great success. Many other benzothiazole, benzoxazole, benzofuran, imidazopyridine, and styrylbenzene derivatives have been labeled with F-18 and I-123 to improve the imaging quality. However, [C-11]6-OH-BTA-1 still remains as the best. However, short half-life of C-11 is a limitation of wide distribution of this agent. So, it is still required to develop an Tc-99m, F-18 or I-123 labeled agent for {beta} - amyloid imaging agent.

  13. Chemical spectroscopy

    International Nuclear Information System (INIS)

    The purpose of chemical spectroscopy with neutrons is to utilize the dependence of neutron scattering cross-sections on isotope and on momentum transfer (which probes the spatial extent of the excitation) to understand fundamental and applied aspects of the dynamics of molecules and fluids. Chemical spectroscopy is divided into three energy ranges: vibrational spectroscopy, 25-500 MeV, for which much of the work is done on Be-filter analyzer instruments; low energy spectroscopy, less than 25 MeV; and high resolution spectroscopy, less than 1 MeV, which typically is performed on backscattering spectrometers. Representative examples of measurements of the Q-depenence of vibrational spectra, higher energy resolution as well as extension of the Q-range to lower values at high energy transfers, and provisions of higher sensitivities in vibrational spectroscopy are discussed. High resolution, high sensitivity, and polarization analysis studies in low energy spectroscopy are discussed. Applications of very high resolution spectroscopy are also discussed

  14. Galiposin: a new beta-hydroxychalcone from Galipea granulosa.

    Science.gov (United States)

    López, J A; Barillas, W; Gomez-Laurito, J; Martin, G E; Lin, F T; Al-Rehaily, A J; Zemaitis, M A; Schiff, P L

    1998-02-01

    A novel beta-hydroxychalcone, galiposin, was isolated from the bark of Galipea granulosa. The structure of galiposin was established via spectroscopic analysis, including high resolution one- and two-dimensional nuclear magnetic resonance spectrometry, as well as mass spectroscopy. PMID:17253223

  15. Laser spectroscopy

    CERN Document Server

    Demtröder, Wolfgang

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., ultrafast lasers (atto- and femto-second lasers) and parametric oscillators, coherent matter waves, Doppler-free Fourier spectroscopy with optical frequency combs, interference spectroscopy, quantum optics, the interferometric detection of gravitational waves and still more applications in chemical analysis, medical diagnostics, and engineering.

  16. Synthesis of beta carbon nitride nanosized crystal through mechanochemical reaction

    CERN Document Server

    Yin Long Wei; Liu Yu Xian; Sui Jin Ling; Wang Jing Min

    2003-01-01

    Nanosized beta carbon nitride (beta-C sub 3 N sub 4), of grain size several tens of nanometres, has been synthesized by mechanochemical reaction processing. The low-cost synthetic method developed facilitates the novel and effective synthesis of nanosized crystalline beta-C sub 3 N sub 4 (a = 6.36 A, c = 4.648 A) powders. The graphite powders were first milled to a nanoscale state, then the nanosized graphite powders were milled in an atmosphere of NH sub 3 gas. It was found that nanosized beta-C sub 3 N sub 4 was formed after high-energy ball milling under an NH sub 3 atmosphere. After thermal annealing, the shape of the beta-C sub 3 N sub 4 changes from flake-like to sphere-like. The nanosized beta-C sub 3 N sub 4 formed was characterized by x-ray diffraction, Fourier transformation infrared spectroscopy, and transmission electron microscopy. A solid-gas reaction mechanism was proposed for the formation of nanosized beta-C sub 3 N sub 4 at room temperature induced by mechanochemical activation.

  17. Beta and Gamma Gradients

    DEFF Research Database (Denmark)

    Løvborg, Leif; Gaffney, C. F.; Clark, P. A.;

    1985-01-01

    Experimental and/or theoretical estimates are presented concerning, (i) attenuation within the sample of beta and gamma radiation from the soil, (ii) the gamma dose within the sample due to its own radioactivity, and (iii) the soil gamma dose in the proximity of boundaries between regions...... of differing radioactivity. It is confirmed that removal of the outer 2 mm of sample is adequate to remove influence from soil beta dose and estimates are made of the error introduced by non-removal. Other evaluations include variation of the soil gamma dose near the ground surface and it appears...

  18. Double beta decay experiments

    International Nuclear Information System (INIS)

    The great sensitivity of double beta decay to neutrino mass and right handed currents has motivated many new and exciting attempts to observe this elusive nuclear phenomenon directly. Experiments in operation and other coming on line in the next one or two years are expected to result in order-of-magnitude improvements in detectable half lives for both the two-neutrino and no-neutrino modes. A brief history of double beta decay experiments is presented together with a discussion of current experimental efforts, including a gas filled time projection chamber being used to study selenium-82. (author)

  19. Evaluation of neutrino masses from $m_{\\beta\\beta}$ values

    CERN Document Server

    Khrushchov, V V

    2008-01-01

    A neutrino mass matrix is considered under conditions of the CP invariance and the negligible reactor mixing $\\theta_{13}$ angle. Absolute mass values for three neutrinos are evaluated in normal and inverted hierarchy spectra on the ground of data for oscillation mixing neutrino parameters and effective neutrino mass entering into a probability of neutrinoless two beta decay $m_{\\beta\\beta}$ values.

  20. Trichoderma .beta.-glucosidase

    Science.gov (United States)

    Dunn-Coleman, Nigel; Goedegebuur, Frits; Ward, Michael; Yao, Jian

    2006-01-03

    The present invention provides a novel .beta.-glucosidase nucleic acid sequence, designated bgl3, and the corresponding BGL3 amino acid sequence. The invention also provides expression vectors and host cells comprising a nucleic acid sequence encoding BGL3, recombinant BGL3 proteins and methods for producing the same.

  1. Applied Beta Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Rich, B.L.

    1986-01-01

    Measurements of beta and/or nonpenetrating exposure results is complicated and past techniques and capabilities have resulted in significant inaccuracies in recorded results. Current developments have resulted in increased capabilities which make the results more accurate and should result in less total exposure to the work force. Continued development of works in progress should provide equivalent future improvements.

  2. Neutrinoless Double Beta Decay

    CERN Document Server

    Päs, Heinrich

    2015-01-01

    We review the potential to probe new physics with neutrinoless double beta decay $(A,Z) \\to (A,Z+2) + 2 e^-$. Both the standard long-range light neutrino mechanism as well as short-range mechanisms mediated by heavy particles are discussed. We also stress aspects of the connection to lepton number violation at colliders and the implications for baryogenesis.

  3. Interferon Beta-1b Injection

    Science.gov (United States)

    Interferon beta-1b injection is used to reduce episodes of symptoms in patients with relapsing-remitting (course ... and problems with vision, speech, and bladder control). Interferon beta-1b is in a class of medications ...

  4. Genetics Home Reference: beta thalassemia

    Science.gov (United States)

    ... for Disease Control and Prevention Centre for Genetics Education (Australia) Cold Spring Harbor Laboratory: Your Genes Your Health Disease InfoSearch: Beta Thalassemia Genomics Education Programme (UK) MalaCards: dominant beta-thalassemia Merck Manual ...

  5. Beta emitters and radiation protection

    DEFF Research Database (Denmark)

    Jødal, Lars

    2009-01-01

    BACKGROUND. Beta emitters, such as 90Y, are increasingly being used for cancer treatment. However, beta emitters demand other precautions than gamma emitters during preparation and administration, especially concerning shielding. AIM. To discuss practical precautions for handling beta emitters...... on the outside of the primary shielding material. If suitable shielding is used and larger numbers of handlings are divided among several persons, then handling of beta emitters can be a safe procedure....

  6. Radiation synthesis of gelatin/CM-chitosan/{beta}-tricalcium phosphate composite scaffold for bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Ying [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Xu Ling, E-mail: lingxu@pku.edu.cn [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang Xiangmei; Zhao Yinghui [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wei Shicheng, E-mail: sc-wei@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Zhai Maolin [Beijing National Laboratory for Molecular Sciences, Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

    2012-05-01

    A series of biodegradable composite scaffolds was fabricated from an aqueous solution of gelatin, carboxymethyl chitosan (CM-chitosan) and {beta}-tricalcium phosphate ({beta}-TCP) by radiation-induced crosslinking at ambient temperature. Ultrasonic treatment on the polymer solutions significantly influenced the distribution of {beta}-TCP particles. An ultrasonic time of 20 min, followed by 30 kGy irradiation induced a crosslinked scaffold with homogeneous distribution of {beta}-TCP particles, interconnected porous structure, sound swelling capacity and mechanical strength. Fourier Transform Infrared Spectroscopy and X-ray Diffraction analysis indicated that {beta}-TCP successfully incorporated with the network of gelatin and CM-chitosan. In vivo implantation of the scaffold into the mandible of beagle dog revealed that the scaffolds had excellent biocompatibility and the presence of {beta}-TCP can accelerate bone regeneration. The comprehensive results of this study paved way for the application of gelatin/CM-chitosan/{beta}-TCP composite scaffolds as candidate of bone tissue engineering material. - Highlights: Black-Right-Pointing-Pointer Radiation induced a crosslinked scaffold with interconnected porous structure. Black-Right-Pointing-Pointer Ultrasonic time of 20 min led to homogenerously distribution of {beta}-TCP. Black-Right-Pointing-Pointer Increasing amount of {beta}-TCP would restrict the swelling properties. Black-Right-Pointing-Pointer Proper fraction of {beta}-TCP will promote the mechanical properties of the scaffolds. Black-Right-Pointing-Pointer Hybrid of {beta}-TCP promoted the bone regeneration of the mandibles of beagle dogs.

  7. Misleading Betas: An Educational Example

    Science.gov (United States)

    Chong, James; Halcoussis, Dennis; Phillips, G. Michael

    2012-01-01

    The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical "Anscombe quartet" results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the…

  8. TGF-beta and osteoarthritis.

    NARCIS (Netherlands)

    Blaney Davidson, E.N.; Kraan, P.M. van der; Berg, W.B. van den

    2007-01-01

    OBJECTIVE: Cartilage damage is a major problem in osteoarthritis (OA). Growth factors like transforming growth factor-beta (TGF-beta) have great potential in cartilage repair. In this review, we will focus on the potential therapeutic intervention in OA with TGF-beta, application of the growth facto

  9. Nuclear spectroscopy

    CERN Document Server

    Ajzenberg-Selove, Fay

    1960-01-01

    Nuclear Spectroscopy, Part A deals with the experimental and theoretical techniques involved in nuclear spectroscopy.This book discusses the interactions of charged particles with matter, gaseous ionization detectors, and particular mass attenuation coefficients. The magnetic gamma-ray spectrometers for photo or internal-conversion electrons, general characteristics of cross-section variation with energy, and measurement of fast neutron spectra are also elaborated. This text likewise covers the elastic scattering of photons by nuclei and measurement of widths of gamma-radiating levels.This pub

  10. Optogalvanic spectroscopy

    International Nuclear Information System (INIS)

    Laser induced optogalvanic spectroscopy in a hollow cathode-produced plasma has been used to resolve the isotopic structure of some absorption lines in uranium. We have shown that the optogalvanic signal associated with any isotope can be related to the concentration of that isotope in a multi-isotopic sample. From the results we have obtained, optogalvanic spectroscopy of sputtered samples appears to be an interesting approach to the isotopic analysis of both natural and enriched uranium and could easily be applied to the analysis of other fissile elements, such as the plutonium isotopes

  11. Identification of a Novel Parallel beta-Strand Conformation within Molecular Monolayer of Amyloid Peptide

    DEFF Research Database (Denmark)

    Liu, Lei; Li, Qiang; Zhang, Shuai;

    2016-01-01

    technique with force controlled in pico-Newton range, combining with molecular dynamic simulation. The identified parallel beta-strand-like structure of molecular monolayer is distinct from the antiparallel beta-strand structure of A beta(33-42) amyloid fibril. This finding enriches the molecular structures....... In this work, the early A beta(33-42) aggregates forming the molecular monolayer at hydrophobic interface are investigated. The molecular monolayer of amyloid peptide A beta(33-42) consisting of novel parallel beta-strand-like structure is further revealed by means of a quantitative nanomechanical spectroscopy......The differentiation of protein properties and biological functions arises from the variation in the primary and secondary structure. Specifically, in abnormal assemblies of protein, such as amyloid peptide, the secondary structure is closely correlated with the stable ensemble and the cytotoxicity...

  12. A beta2-microglobulin cleavage variant fibrillates at near-physiological pH

    DEFF Research Database (Denmark)

    Corlin, Dorthe B; Johnsen, Christina K; Nissen, Mogens H;

    2009-01-01

    several days. Here, we show that amyloid fibrils are generated in less than an hour when a cleavage variant of beta2m--found in the circulation of many dialysis patients--is exposed to pH levels (pH 6.6) occurring in joints during inflammation. Aggregation and fibrillation, including seeding effects......Beta2-microglobulin (beta2m) deposits as amyloid in dialysis-related amyloidosis (DRA), predominantly in joints. The molecular mechanisms underlying the amyloidogenicity of beta2m are still largely unknown. In vitro, acidic conditions, pH ... with intact, native beta2m were studied by Thioflavin T fluorescence spectroscopy, turbidimetry, capillary electrophoresis, and electron microscopy. We conclude that a biologically relevant variant of beta2m is amyloidogenic at slightly acidic pH. Also, only a very small amount of preformed fibrils...

  13. Beta-thalassemia.

    Science.gov (United States)

    Galanello, Renzo; Origa, Raffaella

    2010-05-21

    Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta

  14. Beta-thalassemia

    Directory of Open Access Journals (Sweden)

    Origa Raffaella

    2010-05-01

    Full Text Available Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands, dilated myocardiopathy, liver fibrosis and cirrhosis. Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes, gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely

  15. Coroutine Sequencing in BETA

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger;

    In object-oriented programming, a program execution is viewed as a physical model of some real or imaginary part of the world. A language supporting object-oriented programming must therefore contain comprehensive facilities for modeling phenomena and concepts form the application domain. Many ap...... applications in the real world consist of objects carrying out sequential processes. Coroutines may be used for modeling objects that alternate between a number of sequential processes. The authors describe coroutines in BETA...

  16. Beta decay for pedestrians

    CERN Document Server

    Lipkin, Harry Jeannot

    1962-01-01

    The ""pedestrian approach"" was developed to describe some essentially simple experimental results and their theoretical implications in plain language. In this graduate-level text, Harry J. Lipkin presents simply, but without oversimplification, the aspects of beta decay that can be understood without reference to the formal theory; that is, the reactions that follow directly from conservation laws and elementary quantum mechanics.The pedestrian treatment is neither a substitute for a complete treatment nor a watered-down version.

  17. Integration of BETA with Eclipse

    DEFF Research Database (Denmark)

    Andersen, Peter; Madsen, Ole Lehrmann; Enevoldsen, Mads Brøgger

    2004-01-01

    This paper presents language interoperability issues appearing in order to implement support for the BETA language in the Java-based Eclipse integrated development environment. One of the challenges is to implement plug-ins in BETA and be able to load them in Eclipse. In order to do this, some form...... of language interoperability between Java and BETA is required. The first approach is to use the Java Native Interface and use C to bridge between Java and BETA. This results in a workable, but complicated solution. The second approach is to let the BETA compiler generate Java class files. With this approach...... it is possible to implement plug-ins in BETA and even inherit from Java classes. In the paper the two approaches are described together with part of the mapping from BETA to Java class files. http://www.sciencedirect.com/science/journal/15710661...

  18. Regulation of beta cell replication

    DEFF Research Database (Denmark)

    Lee, Ying C; Nielsen, Jens Høiriis

    2008-01-01

    Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

  19. Beta cell adaptation in pregnancy

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis

    2016-01-01

    Pregnancy is associated with a compensatory increase in beta cell mass. It is well established that somatolactogenic hormones contribute to the expansion both indirectly by their insulin antagonistic effects and directly by their mitogenic effects on the beta cells via receptors for prolactin...... and growth hormone expressed in rodent beta cells. However, the beta cell expansion in human pregnancy seems to occur by neogenesis of beta cells from putative progenitor cells rather than by proliferation of existing beta cells. Claes Hellerström has pioneered the research on beta cell growth for decades......, but the mechanisms involved are still not clarified. In this review the information obtained in previous studies is recapitulated together with some of the current attempts to resolve the controversy in the field: identification of the putative progenitor cells, identification of the factors involved...

  20. Bioimpedance Spectroscopy

    DEFF Research Database (Denmark)

    Klösgen, Beate; Rümenapp, Christine; Gleich, Bernhard

    2011-01-01

    causes relaxation processes with characteristic contributions to the frequency-dependent complex dielectric constant. These dipolar relaxations were initially described by Debye (Polare Molekeln 1929). They are the basis of impedance spectroscopy (K’Owino and Sadik Electroanalysis 17(23):2101–2113, 2005...

  1. PLASMA SPECTROSCOPY

    NARCIS (Netherlands)

    Jaspers, R. J. E.

    2010-01-01

    A brief introduction into the spectroscopy of fusion plasmas is presented. Basic principles of the emission of ionic, atomic and molecular radiation is explained and a survey of the effects, which lead to the population of the respective excited levels, is given. Line radiation, continuum radiation,

  2. LHCb: $2\\beta_s$ measurement at LHCb

    CERN Multimedia

    Conti, G

    2009-01-01

    A measurement of $2\\beta_s$, the phase of the $B_s-\\bar{B_s}$ oscillation amplitude with respect to that of the ${\\rm b} \\rightarrow {\\rm c^{+}}{\\rm W^{-}}$ tree decay amplitude, is one of the key goals of the LHCb experiment with first data. In the Standard Model (SM), $2\\beta_s$ is predicted to be $0.0360^{+0.0020}_{-0.0016} \\rm rad$. The current constraints from the Tevatron are: $2\\beta_{s}\\in[0.32 ; 2.82]$ at 68$\\%$CL from the CDF experiment and $2\\beta_{s}=0.57^{+0.24}_{-0.30}$ from the D$\\oslash$ experiment. Although the statistical uncertainties are large, these results hint at the possible contribution of New Physics in the $B_s-\\bar{B_s}$ box diagram. After one year of data taking at LHCb at an average luminosity of $\\mathcal{L}\\sim2\\cdot10^{32}\\rm cm^{-2} \\rm s^{-1}$ (integrated luminosity $\\mathcal{L}_{\\rm int}\\sim 2 \\rm fb^{-1}$), the expected statistical uncertainty on the measurement is $\\sigma(2\\beta_s)\\simeq 0.03$. This uncertainty is similar to the $2\\beta_s$ value predicted by the SM.

  3. Biosynthesis of marsupial milk oligosaccharides. II: Characterization of a beta 6-N-acetylglucosaminyltransferase in lactating mammary glands of the tammar wallaby, Macropus eugenii.

    Science.gov (United States)

    Urashima, T; Messer, M; Bubb, W A

    1992-09-15

    Tammar wallaby (Macropus eugenii) mammary glands contain a UDP-GlcNAc:Gal beta 1----3Gal beta 1----4Glc beta 1----6-N-acetylglucosaminyltransferase (GlcNAcT) whose activity has been characterized with respect to the effect of pH, apparent Km for acceptor, effects of bivalent metal ions, acceptor specificity and identity of products. The enzyme did not show an absolute requirement for any bivalent metal ion but its activity was increased markedly by Mg2+, Ca2+ and Ba2+ and, to a lesser extent, by Mn2+. When Gal beta 1----3Gal beta 1----4Glc was used as acceptor, the product was Gal beta 1----3[GlcNAc beta 1----6]Gal beta 1----4Glc. With Gal beta 1----3Gal beta 1----3Gal beta 1----4Glc as acceptor, the product was shown, by 1H-NMR spectroscopy and exo-beta-galactosidase digestion, to be a novel pentasaccharide with the structure Gal beta 1----3[GlcNAc beta 1----6]Gal beta 1----3Gal beta 1----4Glc, suggesting that the enzyme recognises the non-reducing end of the acceptor substrate, rather than the reducing end. PMID:1388055

  4. Optical Spectroscopy

    DEFF Research Database (Denmark)

    Thyrhaug, Erling

    containing systems using simple instrumentation and well-known and understood theoretical concepts. Overall it is attempted to achieve this goal by presenting five research projects that I have been involved in during my Ph.D. studies which collectively demonstrate some of the many possibilities of gaining...... containing systems and are characterized using techniques in optical spectroscopy. Of the standard techniques in optical spectroscopy, particular attention has been paid to those based on time-resolved measurements and polarization, which is reflected in the experiment design in the projects. Not all...... solution. In project 2 the intramolecular excited state association reaction between aniline and anthracene is characterized by both steady-state and time-resolved techniques, where the time resolved fluorescence measurements in particular allowed for the determination of the reaction rate constants...

  5. Beta-decay properties of $^{25}$Si and $^{26}$P

    CERN Document Server

    Thomas, J C; Äystö, J; Béraud, R; Blank, B; Canchel, G; Czajkowski, S; Dendooven, P; Ensallem, A; Giovinazzo, J; Guillet, N; Honkanen, J; Jokinen, A; Laird, A M; Lewitowicz, M; Longour, C; De Santos, F O; Peräjärvi, K; democrite-00023307, ccsd

    2004-01-01

    The $\\beta$-decay properties of the neutron-deficient nuclei $^{25}$Si and $^{26}$P have been investigated at the GANIL/LISE3 facility by means of charged-particle and $\\gamma$-ray spectroscopy. The decay schemes obtained and the Gamow-Teller strength distributions are compared to shell-model calculations based on the USD interaction. B(GT) values derived from the absolute measurement of the $\\beta$-decay branching ratios give rise to a quenching factor of the Gamow-Teller strength of 0.6. A precise half-life of 43.7 (6) ms was determined for $^{26}$P, the $\\beta$- (2)p decay mode of which is described.

  6. Precision Study of the $\\beta$-decay of $^{62}$Ga

    CERN Multimedia

    2002-01-01

    It is proposed to perform a precision study of the $\\beta$-decay of $\\,^{62}$Ga taking advantage of recent developments of the ISOLDE Laser Ion Source. The goal is to eventually extend the high-precision knowledge of superallowed $\\beta$-decays beyond the nine decays that presently are used for extracting the V$_{ud}$ quark mixing matrix element of the CKM matrix. The scientific motivations are the current deviation of more than 2$\\sigma$ of the unitary condition of this matrix, which could be an indication of non-standard-model physics, and a test of the theoretical corrections applied to the experimental data. The experiment will utilise the Total Absorption $\\gamma$-ray (TAG) spectrometer in order to determine weak branchings to excited states in $^{62}$Zn and the ISOLDE spectroscopy station to perform half-life measurements and detailed spectroscopy of this nucleus.

  7. 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.

  8. Xeroradiography in. beta. -thalassaemia

    Energy Technology Data Exchange (ETDEWEB)

    Scutellari, P.N.; Orzincolo, C.; Tamarozzi, R.

    1985-01-01

    Xeroradiographic investigations of the skull, hand, and elbow were performed on 27 patients with homozygous ..beta..-thalassaemia. The results were compared with plain radiographic examinations. Xeroradiography, because of its technical properties (i.e. edge contrast enhancement and wide latitude), was shown to demonstrate cortical thinning of long bones, swelling of the diploic space in the skull, and reticulated patterns in the elbow better than standard radiography. Moreover, the use of 'positive' mode imaging was shown to have advantages in the study of the skull and extremities.

  9. Laser spectroscopy of atomic beams of short-lived nuclei

    International Nuclear Information System (INIS)

    A possibility of performing laser-nuclear-spectroscopic experiments at qualitatively new level aimed to solve the second-glass current problem and to search T-non invariant effects in the beta-decay of atomic nuclei is discussed. The question of the increase in efficiency of the experiments, aimed to study the main characteristics of nuclei, far from the beta-stability, by means of the laser spectroscopy methods is considered. 147 refs.; 5 figs.; 1 tab

  10. Double beta decay: present status

    OpenAIRE

    Barabash, A. S.

    2008-01-01

    The present status of double beta decay experiments (including the search for $2\\beta^{+}$, EC$\\beta^{+}$ and ECEC processes) are reviewed. The results of the most sensitive experiments are discussed. Average and recommended half-life values for two-neutrino double beta decay are presented. Conservative upper limits on effective Majorana neutrino mass and the coupling constant of the Majoron to the neutrino are established as $ < 0.75$ eV and $ < 1.9 \\cdot 10^{-4}$, respectively. Proposals fo...

  11. Scintillator based beta batteries

    Science.gov (United States)

    Rensing, Noa M.; Tiernan, Timothy C.; Shirwadkar, Urmila; O'Dougherty, Patrick; Freed, Sara; Hawrami, Rastgo; Squillante, Michael R.

    2013-05-01

    Some long-term, remote applications do not have access to conventional harvestable energy in the form of solar radiation (or other ambient light), wind, environmental vibration, or wave motion. Radiation Monitoring Devices, Inc. (RMD) is carrying out research to address the most challenging applications that need power for many months or years and which have undependable or no access to environmental energy. Radioisotopes are an attractive candidate for this energy source, as they can offer a very high energy density combined with a long lifetime. Both large scale nuclear power plants and radiothermal generators are based on converting nuclear energy to heat, but do not scale well to small sizes. Furthermore, thermo-mechanical power plants depend on moving parts, and RTG's suffer from low efficiency. To address the need for compact nuclear power devices, RMD is developing a novel beta battery, in which the beta emissions from a radioisotope are converted to visible light in a scintillator and then the visible light is converted to electrical power in a photodiode. By incorporating 90Sr into the scintillator SrI2 and coupling the material to a wavelength-matched solar cell, we will create a scalable, compact power source capable of supplying milliwatts to several watts of power over a period of up to 30 years. We will present the latest results of radiation damage studies and materials processing development efforts, and discuss how these factors interact to set the operating life and energy density of the device.

  12. Beta section Beta: biogeographical patterns of variation and taxonomy.

    NARCIS (Netherlands)

    Letschert, J.P.W.

    1993-01-01

    In Chapter 1 an account is given of the historical subdivision of the genus Beta and its sections, and the relations of the sections are discussed. Emphasis is given to the taxonomic treatment of wild section Beta by various authors. The Linnaean names B. vulgaris L. and B. maritima L. are lectotypi

  13. Laser spectroscopy

    CERN Document Server

    Demtröder, Wolfgang

    2008-01-01

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., frequency doubling in external cavities, reliable cw-parametric oscillators, tunable narrow-band UV sources, more sensitive detection techniques, tunable femtosecond and sub-femtosecond lasers (X-ray region and the attosecond range), control of atomic and molecular excitations, frequency combs able to synchronize independent femtosecond lasers, coherent matter waves, and still more applications in chemical analysis, medical diagnostics, and engineering.

  14. Physico-chemical characterization of benzocaine-beta-cyclodextrin inclusion complexes.

    Science.gov (United States)

    Pinto, Luciana M A; Fraceto, Leonardo Fernandes; Santana, Maria Helena A; Pertinhez, Thelma A; Junior, Sérgio Oyama; de Paula, Eneida

    2005-10-01

    Local anesthetics are able to induce pain relief by binding to the sodium channel of excitable membranes, blocking the influx of sodium ions and the propagation of the nervous impulse. Benzocaine (BZC) is a local anesthetic whose low water-solubility limits its application to topical formulations. The present work focuses on the characterization of inclusion complexes of BZC in beta-cyclodextrin (beta-CD). Differential scanning calorimetry and electron microscopy gave evidences of the formation and the morphology of the complex. Fluorescence spectroscopy showed a BZC/beta-CD 1:1 stoichiometry. Phase-solubility diagrams allowed the determination of the association constants between BZC and beta-CD (549 M(-1)) and revealed that a three-fold increase in BZC solubility can be reached upon complexation with beta-CD. The details of BZC/beta-CD molecular interaction were analyzed by 1H 2D NMR allowing the proposition of an inclusion model for BZC into beta-CD where the aromatic ring of the anesthetic is located near the head of the beta-CD cavity. Moreover, in preliminary toxicity studies, the complex seems to be less toxic than BZC alone, since it induced a decrease in the in vitro oxidation of human hemoglobin. These results suggest that the BZC/beta-CD complex represents an effective novel formulation to enhance BZC solubility in water, turning it promising for use outside its traditional application, i.e., in infiltrative anesthesia.

  15. Beta Function and Anomalous Dimensions

    DEFF Research Database (Denmark)

    Pica, Claudio; Sannino, Francesco

    2011-01-01

    We demonstrate that it is possible to determine the coefficients of an all-order beta function linear in the anomalous dimensions using as data the two-loop coefficients together with the first one of the anomalous dimensions which are universal. The beta function allows to determine the anomalous...

  16. The best-beta CAPM

    NARCIS (Netherlands)

    L. Zou

    2006-01-01

    The issue of 'best-beta' arises as soon as potential errors in the Sharpe-Lintner-Black capital asset pricing model (CAPM) are acknowledged. By incorporating a target variable into the investor preferences, this study derives a best-beta CAPM (BCAPM) that maintains the CAPM's theoretical appeal and

  17. RAVEN Beta Release

    Energy Technology Data Exchange (ETDEWEB)

    Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, Andrea [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cogliati, Joshua Joseph [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mandelli, Diego [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kinoshita, Robert Arthur [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Congjian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Maljovec, Daniel Patrick [Idaho National Lab. (INL), Idaho Falls, ID (United States); Talbot, Paul William [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  18. Beta systems error analysis

    Science.gov (United States)

    1984-01-01

    The atmospheric backscatter coefficient, beta, measured with an airborne CO Laser Doppler Velocimeter (LDV) system operating in a continuous wave, focussed model is discussed. The Single Particle Mode (SPM) algorithm, was developed from concept through analysis of an extensive amount of data obtained with the system on board a NASA aircraft. The SPM algorithm is intended to be employed in situations where one particle at a time appears in the sensitive volume of the LDV. In addition to giving the backscatter coefficient, the SPM algorithm also produces as intermediate results the aerosol density and the aerosol backscatter cross section distribution. A second method, which measures only the atmospheric backscatter coefficient, is called the Volume Mode (VM) and was simultaneously employed. The results of these two methods differed by slightly less than an order of magnitude. The measurement uncertainties or other errors in the results of the two methods are examined.

  19. RAVEN Beta Release

    International Nuclear Information System (INIS)

    This documents the release of the Risk Analysis Virtual Environment (RAVEN) code. A description of the RAVEN code is provided, and discussion of the release process for the M2LW-16IN0704045 milestone. The RAVEN code is a generic software framework to perform parametric and probabilistic analysis based on the response of complex system codes. RAVEN is capable of investigating the system response as well as the input space using Monte Carlo, Grid, or Latin Hyper Cube sampling schemes, but its strength is focused toward system feature discovery, such as limit surfaces, separating regions of the input space leading to system failure, using dynamic supervised learning techniques. RAVEN has now increased in maturity enough for the Beta 1.0 release.

  20. Thermodynamics of complexes between nucleobase-modified {beta}-cyclodextrins and bile salts

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yu [Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, 300071 Tianjin (China)], E-mail: yuliu@nankai.edu.cn; Zhang Qian; Guo Dongsheng; Zhuang Ruijie; Wang Lihua [Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, 300071 Tianjin (China)

    2008-04-10

    The binding of three nucleobase-modified {beta}-CDs, (i.e., mono(6-ade-6-deoxy)-{beta}-CD 2, mono(6-thy-6-deoxy)-{beta}-CD 3, and mono(6-ura-6-deoxy)-{beta}-CD 4) with four bile salts (deoxycholate, DCA; cholate, CA; glycocholate, GCA; and taurocholate, TCA) were investigated by means of circular dichroism, 2D NMR spectroscopy and calorimetric titration. The results show the binding of host 2 with bile salts is weaker and different from hosts 3 and 4. Enthalpy changes between hosts 2-4 and bile salts are much more favorable than those of native {beta}-CD 1, whereas the entropy changes are unfavorable.

  1. Design and production of sintered {beta}-tricalcium phosphate 3D scaffolds for bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Carlos F.L. [CICS-UBI - Centro de Investigacao em Ciencias da Saude, Universidade da Beira Interior, Covilha (Portugal); Silva, Abilio P. [Centro de Ciencia e Tecnologia Aeroespaciais, Universidade da Beira Interior, Covilha (Portugal); Lopes, Luis [CICS-UBI - Centro de Investigacao em Ciencias da Saude, Universidade da Beira Interior, Covilha (Portugal); Pires, Ines [Instituto de Engenharia Mecanica - Lisboa (IDMEC Lisboa/IST/UTL), Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); Correia, Ilidio J., E-mail: icorreia@ubi.pt [CICS-UBI - Centro de Investigacao em Ciencias da Saude, Universidade da Beira Interior, Covilha (Portugal)

    2012-07-01

    The characteristics of sintered {beta}-tricalcium phosphate ({beta}-TCP) scaffolds produced by 3D printing were studied by means of X-ray diffraction, Scanning Electron Microscopy, Fourier transform infrared spectroscopy, uniaxial compression tests and cytotoxicity tests, using human osteoblast cells. The results reported include details of the {beta}-TCP scaffolds' porosity, density, phase stability, mechanical behavior and cytotoxic profile. Collectively, these properties are fundamental for the future application of these scaffolds as bone substitutes for individualized therapy. Highlights: Black-Right-Pointing-Pointer {beta}-Tricalcium phosphate ({beta}-TCP) 3D scaffolds were produced by rapid prototyping. Black-Right-Pointing-Pointer Scaffold properties were assessed by SEM, FTIR, XRD and by mechanical tests. Black-Right-Pointing-Pointer The cytotoxic profile of the scaffolds was characterized by in vitro assays. Black-Right-Pointing-Pointer Scaffolds have good properties for its application as bone substitutes for individualized therapy.

  2. Beta Beams Implementation at CERN

    CERN Document Server

    Hansen, Christian

    2011-01-01

    Beta Beam,the concept of generating a pure and intense (anti) neutrino beam by letting accelerated radioactive ions beta decay in a storage ring, called Decay Ring (DR), is the base of one of the proposed next generation neutrino oscillation facilities, necessary for a complete study of the neutrino oscillation parameter space. Sensitivities of the unknown neutrino oscillation parameters depend on the Decay Ring's ion intensity and of it's duty factor (the filled ratio of the ring). Therefore efficient ion production, stripping, bunching, acceleration and storing are crucial sub-projects under study and development within the Beta Beam collaboration. Specifically the feasibility of these tasks as parts of a Beta Beam implementation at CERN will be discussed in this report. The positive impact of the large {\\theta}13 indications from T2K on the Beta Beam performance will also be discussed.

  3. Inclusion phenomena of clove oil with alpha-, beta-, gamma- and heptakis (2,6-di-O-methyl)-beta-cyclodextrin.

    Science.gov (United States)

    Song, L X; Xu, P; Wang, H M; Yang, Y

    2009-01-01

    Inclusion interactions of alpha-, beta-, gamma- and heptakis (2,6-di-O-methyl)-beta-cyclodextrin (DMbeta-CD) as hosts with clove oil (an impure eugenol, I-Eug) as guest in aqueous solution were investigated by fluorescence emission spectra. The binding constants of different hosts to I-Eug in aqueous solution decreased in the order: gamma- > beta- > DMbeta- > alpha-CD. Two solid supramolecular inclusion complexes, I-Eug-beta-CD and I-Eug-gamma-CD, were prepared and characterised by nuclear magnetic resonance, powder X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis. All the results proved the formation of I-Eug-CD. The inclusion differences between I-Eug and pure eugenol were discussed. The relative contents of the main component eugenol (Eug), second component (eugenol acetate, Eua) and others in I-Eug were found to be fairly different before and after being included by beta-CD, according to the data obtained from high performance liquid chromatography. This could be a practical method to extract the effective components (Eug and Eua) from I-Eug.

  4. $\\beta$-decay studies using total absorption techniques some recent results

    CERN Document Server

    Algora, A; García-Borge, M J; Cano-Ott, D; Collatz, R; Courtin, S; Dessagne, P; Fraile-Prieto, L M; Gadea, A; Gelletly, W; Hellström, M; Janas, Z; Jungclaus, A; Karny, M; Kirchner, R; Maréchal, F; Miehé, C; Moroz, F; Nacher, E; Poirier, E; Roeckl, E; Rubio, B; Rykaczewski, K; Scornet, G L; Taín, J L; Tengblad, O; Wittmann, V

    2004-01-01

    $\\beta$-decay experiments, are a primary source of information for nuclear structure studies and at the same time complementary to in-beam investigations far from stability. Although both types of experiment are mainly based on $\\gamma$-ray spectroscopy, they face different experimental problems. The so-called $\\textit{Pandemonium effect}$ is a critical problem in $\\beta$-decay. In this contribution we will present a solution to this problem using total absorption spectroscopy methods. We will also present some examples of experiments carried out with the total absorption spectrometers TAS at GSI and Lucrecia recently installed at CERN. (25 refs).

  5. [Serum beta 2 microglobulin (beta 2M) following renal transplantation].

    Science.gov (United States)

    Pacheco-Silva, A; Nishida, S K; Silva, M S; Ramos, O L; Azjen, H; Pereira, A B

    1994-01-01

    Although there was an important improvement in graft and patient survival the last 10 years, graft rejection continues to be a major barrier to the success of renal transplantation. Identification of a laboratory test that could help to diagnose graft rejection would facilitate the management of renal transplanted patients. PURPOSE--To evaluate the utility of monitoring serum beta 2M in recently transplanted patients. METHODS--We daily determined serum beta 2M levels in 20 receptors of renal grafts (10 from living related and 10 from cadaveric donors) and compared them to their clinical and laboratory evolution. RESULTS--Eight patients who presented immediate good renal function following grafting and did not have rejection had a mean serum beta 2M of 3.7 mg/L on the 4th day post transplant. The sensitivity of the test for the diagnosis of acute rejection was 87.5%, but the specificity was only 46%. Patients who presented acute tubular necrosis (ATN) without rejection had a progressive decrease in their serum levels of beta 2M, while their serum creatinine changed as they were dialyzed. In contrast, patients with ATN and concomitance of acute rejection or CSA nephrotoxicity presented elevated beta 2M and creatinine serum levels. CONCLUSION--Daily monitoring of serum beta 2M does not improve the ability to diagnose acute rejection in patients with good renal function. However, serum beta 2M levels seemed to be useful in diagnosing acute rejection or CSA nephrotoxicity in patients with ATN.

  6. Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    The emission and absorption of photons taking place without changes in the frequency spectrum of the crystal lattice are known as the Moessbauer effect. It takes place in the low energy levels of heavy nuclei in solid lattices at low temperatures. On the basis of the hyperfine structure of Moessbauer spectra the notions are explained of isomer shift, quadrupole splitting and magnetic splitting. The principle and function are explained of Moessbauer spectrometers and the methods of graphical processing of spectra, also the use of the least square fit. Moessbauer spectroscopy is nondestructive, highly sensitive and selective and makes structural resolution possible. It is used for quantitative and qualitative analysis of compounds. Examples are given of the use of this method for mineralogical and crystallo-chemical analysis of lunar minerals and rocks, for analysis of corrosion products of iron and for phase analysis of alloys. (M.D.)

  7. Evidence for novel beta-sheet structures in Iowa mutant beta-amyloid fibrils.

    Science.gov (United States)

    Tycko, Robert; Sciarretta, Kimberly L; Orgel, Joseph P R O; Meredith, Stephen C

    2009-07-01

    Asp23-to-Asn mutation within the coding sequence of beta-amyloid, called the Iowa mutation, is associated with early onset, familial Alzheimer's disease and cerebral amyloid angiopathy, in which patients develop neuritic plaques and massive vascular deposition predominantly of the mutant peptide. We examined the mutant peptide, D23N-Abeta40, by electron microscopy, X-ray diffraction, and solid-state NMR spectroscopy. D23N-Abeta40 forms fibrils considerably faster than the wild-type peptide (k = 3.77 x 10(-3) min(-1) and 1.07 x 10(-4) min(-1) for D23N-Abeta40 and the wild-type peptide WT-Abeta40, respectively) and without a lag phase. Electron microscopy shows that D23N-Abeta40 forms fibrils with multiple morphologies. X-ray fiber diffraction shows a cross-beta pattern, with a sharp reflection at 4.7 A and a broad reflection at 9.4 A, which is notably smaller than the value for WT-Abeta40 fibrils (10.4 A). Solid-state NMR measurements indicate molecular level polymorphism of the fibrils, with only a minority of D23N-Abeta40 fibrils containing the in-register, parallel beta-sheet structure commonly found in WT-Abeta40 fibrils and most other amyloid fibrils. Antiparallel beta-sheet structures in the majority of fibrils are indicated by measurements of intermolecular distances through (13)C-(13)C and (15)N-(13)C dipole-dipole couplings. An intriguing possibility exists that there is a relationship between the aberrant structure of D23N-Abeta40 fibrils and the unusual vasculotropic clinical picture in these patients.

  8. Intuitionistic Fuzzy Generalized Beta Closed Mappings

    OpenAIRE

    D. Jayanthi

    2014-01-01

    In this paper we introduce intuitionistic fuzzy generalized beta closed mappings and intuitionistic fuzzy generalized beta open mappings. We investigate some of their properties. We also introduce intuitionistic fuzzy M-generalized beta closed mappings as well as intuitionistic fuzzy M-generalized beta open mappings. We provide the relation between intuitionistic fuzzy M-generalized beta closed mappings and intuitionistic fuzzy generalized beta closed mappings.

  9. Effect of beta-cyclodextrin nanocavity confinement on the photophysics of robinetin.

    Science.gov (United States)

    Banerjee, Anwesha; Basu, Kaushik; Sengupta, Pradeep K

    2007-12-14

    We have studied the confinement of robinetin, a therapeutically active plant flavonol, in cyclodextrin (CDx) nanocavities, using steady state and time resolved fluorescence spectroscopy. Enhanced tautomer emission (arising from excited state intramolecular proton transfer (ESIPT)) as well as dramatically blue shifted (approximately 10 nm in beta-CDx and approximately 33 nm in SHP beta-CDx) normal fluorescence observed upon addition of the beta-CDxs indicate that robinetin readily enters the doughnut-shaped hydrophobic cavity of beta-CDx where the chromone moiety is well shielded from external hydrogen bonding perturbations. Detailed analyses of the fluorescence data (emission profile, anisotropy, decay times) indicate that robinetin forms 1:1 inclusion complexes with both natural and chemically modified beta-cyclodextrins (beta-CDx and SHP beta-CDx) with affinity constant values K=195+/-17 M(-1) and 1055+/-48 M(-1) respectively, indicating the prospective utility of SHP beta-CDx in particular as an effective drug carrier. Unlike beta-CDxs, alpha-CDxs do not form inclusion complexes with robinetin. To further characterize the robinetin/beta-CDxs complexes, circular dichroism (CD) spectroscopic studies have been performed, which reveal that incorporation of robinetin molecules in the chiral environment of the beta-CDxs strongly affects the electronic transitions of robinetin leading to the occurrence of positive induced circular dichroism (ICD) bands in the near ultra-violet (UV) region. Molecular mechanics calculations show that the inclusion complex with the chromone ring inserted into the beta-CDx cavity is most favorable, in agreement with our spectroscopic data.

  10. Effect of beta blockade and beta stimulation on stage fright.

    Science.gov (United States)

    Brantigan, C O; Brantigan, T A; Joseph, N

    1982-01-01

    Stage fright, physiologically the "fight or flight" reaction, is a disabling condition to the professional musician. Because it is mediated by the sympathetic nervous system, we have investigated the effects of beta blockade on musical performance with propranolol in a double blind fashion and the effects of beta stimulation using terbutaline. Stage fright symptoms were evaluated in two trials, which included a total of 29 subjects, by questionnaire and by the State Trai Anxiety Inventory. Quality of musical performance was evaluated by experienced music critics. Beta blockade eliminates the physical impediments to performance caused by stage fright and even eliminates the dry mouth so frequently encountered. The quality of musical performance as judged by experienced music critics is significantly improved. This effect is achieved without tranquilization. Beta stimulating drugs increase stage fright problems, and should be used in performing musicians only after consideration of the detrimental effects which they may have on musical performance. PMID:6120650

  11. Experiments on double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Busto, J. [Neuchatel Univ. (Switzerland). Inst. de Physique

    1996-11-01

    The Double Beta Decay, and especially ({beta}{beta}){sub 0{nu}} mode, is an excellent test of Standard Model as well as of neutrino physics. From experimental point of view, a very large number of different techniques are or have been used increasing the sensitivity of this experiments quite a lot (the factor of 10{sup 4} in the last 20 years). In future, in spite of several difficulties, the sensitivity would be increased further, keeping the interest of this very important process. (author) 4 figs., 5 tabs., 21 refs.

  12. Dosimetry of {beta} extensive sources; Dosimetria de fuentes {beta} extensas

    Energy Technology Data Exchange (ETDEWEB)

    Rojas C, E.L.; Lallena R, A.M. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain)

    2002-07-01

    In this work, we have been studied, making use of the Penelope Monte Carlo simulation code, the dosimetry of {beta} extensive sources in situations of spherical geometry including interfaces. These configurations are of interest in the treatment of the called cranealfaringyomes of some synovia leisure of knee and other problems of interest in medical physics. Therefore, its application can be extended toward problems of another areas with similar geometric situation and beta sources. (Author)

  13. Planetary spectroscopy

    International Nuclear Information System (INIS)

    The main goal of the research is charge coupled device (CCD) spectroscopic and imaging studies of the solar system in support of spacecraft investigations. Studies include the physical behavior of comets, the atmosphere of the gaseous planets, and the solid surfaces of satellites and asteroids. The major observing program consisted of approximately 50 nights of photometry of Comet Halley in order to resolve the controversy over this comet's rotation period. This data is presently being analyzed. Additional observing projects included the spectroscopic occultation of Charon by Pluto, reflection spectroscopy of Mercury, and a spectrum of the satellite Oberon. Mercury data does not corroborate the Fe(++) absorption feature reported by McCord and Clark at 8800 A but instead potentially shows a weaker feature at longer wavelengths. This position is in much closer accord with expectations for Mercury since a band center near 8800 A implies too little Fe(++) on Mercury, especially if band shifts with temperature are considered. The Pluto project proved that the deep methane absorptions visible in their combined specta are due soley to Pluto with Charon showing a flat and featureless spectrum. It appears that if Charon ever contained a substantial methane component, the satellite's low surface gravity could not hold it and the methane evaporated and escaped

  14. MHD Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Heeter, R F; Fasoli, A; Testa, D; Sharapov, S; Berk, H L; Breizman, B; Gondhalekar, A; Mantsinen, M

    2004-03-23

    Experiments are conducted on the JET tokamak to assess the diagnostic potential of MHD active and passive spectroscopy, for the plasma bulk and its suprathermal components, using Alfv{acute e}n Eigenmodes (AEs) excited by external antennas and by energetic particles. The measurements of AE frequencies and mode numbers give information on the bulk plasma. Improved equilibrium reconstruction, in particular in terms of radial profiles of density and safety factor, is possible from the comparison between the antenna driven spectrum and that calculated theoretically. Details of the time evolution of the non-monotonic safety factor profile in advanced scenarios can be reconstructed from the frequency of ICRH-driven energetic particle modes. The plasma effective mass can be inferred from the resonant frequency of externally driven AEs in discharges with similar equilibrium profiles. The stability thresholds and the nonlinear development of the instabilities can give clues on energy and spatial distribution of the fast particle population. The presence of unstable AEs provides lower limits in the energy of ICRH generated fast ion tails. Fast ion pressure gradients and their evolution can be inferred from the stability of AEs at different plasma radial positions. Finally, the details of the AE spectrum in the nonlinear stage can be used to obtain information about the fast particle velocity space diffusion.

  15. Beta-Thioxoketones

    DEFF Research Database (Denmark)

    Jørgensen, F. S.; Brown, R. S.; Carlsen, Lars;

    1982-01-01

    X-ray photoelectron spectroscopy has been used to record the 01, and Szp ionization spectra of thioacetylacetone, 2-acetylcyclohexanethione,2 -thioacetylcyclohexanone,th e S-methyl derivative of thioacetylacetone, and propyl 3-mercaptocrotonate in the gas phase. It is shown that both the enol...... and the enethiol tautomers of the /3-thioxoketones can be detected, and the enol/enethiol ratios for thioacetylacetone, 2-acetylcyclohexanethione, and 2-thioacetylcyclohexanone were determined to be 61:39, 30:70, and 80:20, respectively, based on the intensities of the oxygen ionizations. The conclusions derived...... from the sulfur region support the above, although they are less clear due to sulfur spin-orbit splitting. The enol/enethiol ratios obtained in the gas phase by XPS are compared with data from other methods, showing good agreement between results obtained in the gas phase and in solution. The binding...

  16. Beta-gamma discriminator circuit

    International Nuclear Information System (INIS)

    The major difficulty encountered in the determination of beta-ray dose in field conditions is generally the presence of a relatively high gamma-ray component. Conventional dosimetry instruments use a shield on the detector to estimate the gamma-ray component in comparison with the beta-ray component. More accurate dosimetry information can be obtained from the measured beta spectrum itself. At Los Alamos, a detector and discriminator circuit suitable for use in a portable spectrometer have been developed. This instrument will discriminate between gammas and betas in a mixed field. The portable package includes a 256-channel MCA which can be programmed to give a variety of outputs, including a spectral display, and may be programmed to read dose directly

  17. Peginterferon Beta-1a Injection

    Science.gov (United States)

    ... symptoms such as headaches, bone or muscle aches, fever, chills, and tiredness during your treatment with peginterferon beta- ... not go away: headache muscle or joint pain fever chills weakness Some side effects can be serious. If ...

  18. Identification of distinct physiochemical properties of toxic prefibrillar species formed by A{beta} peptide variants

    Energy Technology Data Exchange (ETDEWEB)

    Goeransson, Anna-Lena, E-mail: anngo@ifm.liu.se [Division of Molecular Biotechnology, Department of Physics, Chemistry and Biology, Linkoeping University (Sweden); Nilsson, K. Peter R., E-mail: petni@ifm.liu.se [Division of Organic Chemistry, Department of Physics, Chemistry and Biology, Linkoeping University (Sweden); Kagedal, Katarina, E-mail: katarina.kagedal@liu.se [Department of Clinical and Experimental Medicine, Linkoeping University (Sweden); Brorsson, Ann-Christin, E-mail: anki@ifm.liu.se [Division of Molecular Biotechnology, Department of Physics, Chemistry and Biology, Linkoeping University (Sweden)

    2012-04-20

    Highlights: Black-Right-Pointing-Pointer Identification of toxic prefibrillar A{beta} species. Black-Right-Pointing-Pointer Fluorescence measurements using a combined set of fluorophores. Black-Right-Pointing-Pointer Morphology studies using transmission electron microscopy. -- Abstract: The formation of amyloid-{beta} peptide (A{beta}) aggregates at an early stage during the self-assembly process is an important factor in the development of Alzheimer's disease. The toxic effect is believed to be exerted by prefibrillar species of A{beta}. It is therefore important to identify which prefibrillar species are toxic and characterize their distinct properties. In the present study, we investigated the in vitro aggregation behavior of A{beta}-derived peptides possessing different levels of neurotoxic activity, using fluorescence spectroscopy in combination with transmission electron microscopy. The toxicity of various A{beta} aggregates was assessed by using cultures of human neuroblastoma cells. Through combined use of the fluorescence probe 8-anilino-1-napthalenesulfonate (ANS) and the novel luminescent probe pentamer formyl thiophene acetic acid (p-FTAA), we were able to identify those A{beta} peptide-derived prefibrillar species which exhibited cellular toxicity. In particular, species, which formed early during the aggregation process and showed strong p-FTAA and ANS fluorescence, were the species that possessed toxic activities. Moreover, by manipulating the aggregation conditions, it was possible to change the capacity of the A{beta} peptide to form nontoxic versus toxic species.

  19. State-of-the-Art Beta Detection and Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    David M. Hamby

    2008-08-15

    The research funded by this NEER grant establishes the framework for a detailed understanding of the challenges in beta dosimetry, especially in the presence of a mixed radiation field. The work also stimulated the thinking of the research group which will lead to new concepts in digital signal processing to allow collection of detection signals and real-time analysis such that simultaneous beta and gamma spectroscopy can take place. The work described herein (with detail in the many publications that came out of this research) was conducted in a manner that provided dissertation and thesis topics for three students, one of whom was completely funded by this grant. The overall benefit of the work came in the form of a dramatic shift in signal processing that is normally conducted in analog pulse shape analysis. Analog signal processing was shown not to be feasible for this type of work; digital signal processing was a must. This, in turn, led the research team to a new understanding of pulse analysis, one in which expands the state-of-the-art in simultaneous beta and gamma spectroscopy with a single detector.

  20. Introduction to Spin Label Electron Paramagnetic Resonance Spectroscopy of Proteins

    Science.gov (United States)

    Melanson, Michelle; Sood, Abha; Torok, Fanni; Torok, Marianna

    2013-01-01

    An undergraduate laboratory exercise is described to demonstrate the biochemical applications of electron paramagnetic resonance (EPR) spectroscopy. The beta93 cysteine residue of hemoglobin is labeled by the covalent binding of 3-maleimido-proxyl (5-MSL) and 2,2,5,5-tetramethyl-1-oxyl-3-methyl methanethiosulfonate (MTSL), respectively. The excess…

  1. Synthesis of Beta Pyridyl Carbinol Tartrate

    Directory of Open Access Journals (Sweden)

    S. K. Shukla

    1968-04-01

    Full Text Available A process for the synthesis of Beta pyridine carboxylic acid ethy1 ester starting from quinoline has been developed. Beta-pyridine carboxylic acid ethy1 ester on reduction with lithium aluminium hydride gave Beta-pyridy1 carbinol which on treatment tartaric acid yielded Beta-pyridy1 carbinol tartrate, a vaso dilator known in trade as "Ronicoltartrate".

  2. Apollo applications of beta fiber glass

    Science.gov (United States)

    Naimer, J.

    1971-01-01

    The physical characteristics of Beta fiber glass are discussed. The application of Beta fiber glass for fireproofing the interior of spacecraft compartments is described. Tests to determine the flammability of Beta fiber glass are presented. The application of Beta fiber glass for commercial purposes is examined.

  3. Radiopolymerization of {beta}(-)pinene: A case of chiral amplification

    Energy Technology Data Exchange (ETDEWEB)

    Cataldo, Franco [Soc. Lupi Chemical Research, Via Casilina 1626/A, 00133 Rome (Italy)]. E-mail: cdcata@flashnet.it; Keheyan, Yeghis [CNR, Istituto per lo studio dei Materiali Nanostrutturati, Department of Chemistry, University ' La Sapienza' , P.le Aldo Moro 1, Rome (Italy)

    2006-05-15

    {beta}(-)Pinene was treated with {gamma} radiation at three dose levels: 150, 300 and 600 kGy. The expected effect of radiation at these high doses was the partial racemization of the substrate as already observed in the case of other terpene monomers. Unexpectedly {beta}(-)pinene underwent a radiopolymerization reaction into a solid resin and into a dimer. The structure of the products was studied by FT-IR spectroscopy also in comparison to a reference {beta}(-)pinene resin prepared by cationic polymerization. A highly ordered structure was found in the case of the radiopolymer in comparison to the resin from cationic polymerization. Polarimetric measurements have shown astonishing enhancement in the optical activity of the radiopolymer and radiodimer in comparison to the starting optical activity of the {beta}(-)pinene monomer. The results have been discussed in terms of amplification of chirality caused by {gamma} radiation and the implications of this fact on the mechanism of chiral amplification on prebiotic molecules.

  4. Vasodilatory mechanisms of beta receptor blockade.

    OpenAIRE

    Rath, Géraldine; Balligand, Jean-Luc; Dessy, Chantal

    2012-01-01

    Beta-blockers are widely prescribed for the treatment of a variety of cardiovascular pathologies. Compared to traditional beta-adrenergic antagonists, beta-blockers of the new generation exhibit ancillary properties such as vasodilation through different mechanisms. This translates into a more favorable hemodynamic profile. The relative affinities of beta-adrenoreceptor antagonists towards the three beta-adrenoreceptor isotypes matter for predicting their functional impact on vasomotor contro...

  5. Tables of double beta decay data

    Energy Technology Data Exchange (ETDEWEB)

    Tretyak, V.I. [AN Ukrainskoj SSR, Kiev (Ukraine)]|[Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Zdesenko, Y.G. [AN Ukrainskoj SSR, Kiev (Ukraine)

    1995-12-31

    A compilation of experimental data on double beta decay is presented. The tables contain the most stringent known experimental limits or positive results of 2{beta} transitions of 69 natural nuclides to ground and excited states of daughter nuclei for different channels (2{beta}{sup -}; 2{beta}{sup +}; {epsilon}{beta}{sup +}; 2{epsilon}) and modes (0{nu}; 2{nu}; 0{nu}M) of decay. (authors). 189 refs., 9 figs., 3 tabs.

  6. The GERDA experiment on 0{nu}{beta}{beta} decay

    Energy Technology Data Exchange (ETDEWEB)

    Freund, Kai [Eberhard Karls Universitaet Tuebingen (Germany); Collaboration: GERDA-Collaboration

    2012-07-01

    The Gerda (Germanium Detector Array) collaboration searches for the neutrinoless double beta decay (0{nu}{beta}{beta}) of {sup 76}Ge. The existence of this decay would give rise to the assumption that the neutrino is a Majorana particle, i.e. its own antiparticle. A measured half-life could be used to determine the effective neutrino mass and hence resolve the neutrino mass hierarchy problem. Germanium diodes, isotopically enriched in {sup 76}Ge, are used as both source and detector. Due to the low rate of this decay (T{sub 1/2}>10{sup 25} y), the experimental background must be reduced to a level of 10{sup -2}counts/(kg y keV) or better in the region around Q{sub {beta}{beta}}. To minimize background from cosmogenically produced secondary particles, a low Z shielding is employed. Thus, the naked diodes are operated in a liquid argon cryostat, which is surrounded by a water tank acting as both passive shield and active muon Cherenkov veto. Gerda started the commissioning runs in 2010 and in November 2011, the first phase of data taking with enriched detectors has begun. In this talk, the first year of the experiment is summarized.

  7. Folding and Unfolding of Light-Triggered beta-Hairpin Model Peptides

    NARCIS (Netherlands)

    Schrader, Tobias E.; Cordes, Thorben; Schreier, Wolfgang J.; Koller, Florian O.; Dong, Shou-Liang; Moroder, Luis; Zinth, Wolfgang

    2011-01-01

    Ultrafast spectroscopy in the visible and mid-infrared is used to study the reaction dynamics of two light-triggered model peptides containing an azobenzene derivative as a switching element. One model peptide, the AzoTrpZip2, forms a beta-hairpin structure in the cis form of the chromophore. This p

  8. NMR characterization of a 264-residue hyperthermostable endo-beta-1,3-glucanase.

    NARCIS (Netherlands)

    Ippel, J.H.; Koutsopoulos, S.; Nabuurs, S.M.; Berkel, W.J. van; Oost, J. van der; Mierlo, C.P. van

    2010-01-01

    Insight into the hyperthermostable endo-beta-1,3-glucanase pfLamA from Pyrococcus furiosus is obtained by using NMR spectroscopy. pfLamA functions optimally at 104 degrees C and recently the X-ray structure of pfLamA has been obtained at 20 degrees C, a temperature at which the enzyme is inactive. I

  9. Inclusion complexes of pyrimethamine in 2-hydroxypropyl-beta-cyclodextrin: characterization, phase solubility and molecular modelling.

    Science.gov (United States)

    de Araújo, Márcia Valéria Gaspar; Vieira, Elze Kelly Barbosa; Lázaro, Gilderman Silva; de Souza Conegero, Leila; Ferreira, Odair Pastor; Almeida, Lui S Eduardo; Barreto, Ledjane Silva; da Costa, Nivan Bezerra; Gimenez, Iara F

    2007-09-01

    The inclusion complexation of pyrimethamine in 2-hydroxypropyl-beta-cyclodextrin has been investigated by 2D (1)H NMR, FTIR and UV/visible spectroscopy and also by molecular modelling methods (AM1, PM3, MM3). From the phase-solubility diagram a linear increase was observed in pyrimethamine aqueous solubility in the presence of 2-hydroxypropyl-beta-cyclodextrin, evidencing the formation of a soluble inclusion complex. According to the continuous variation method (Job's plot) applied to fluorescence measurements, a 1:1 stoichiometry has been proposed for the complex. Concerning the structure of the complex, a Cl-in orientation of pyrimethamine in the 2-hydroxypropyl-beta-cyclodextrin cavity has been proposed from the theoretical calculations, being confirmed by two-dimensional (1)H NMR spectroscopy (ROESY). The thermal behaviour has also been studied, providing complementary evidences of complex formation.

  10. Beta-decay total absorption measurements for nuclear technology and astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Taina, J.L. [Instituto de Fisica Corpuscular, C.S.I.C.-U. Valencia (Spain)

    2008-07-01

    An accurate determination of the beta-decay intensity distribution is of importance for basic nuclear physics but also in the fields of reactor technology, astrophysics and fundamental interactions. Most of present information comes from experiments performed with high resolution low efficiency Ge {gamma}-ray spectroscopy, which fails to locate the beta intensity at high excitation energies in complex decays. The total absorption spectroscopy technique with large 4{pi} scintillation detectors can give the correct answer but requires an involved procedure in order to extract the information. Recent work on the systematization of the analysis methods and on the evaluation of the associated systematic uncertainties shows that reliable beta strength distributions can indeed be obtained. (author)

  11. Nuclear magnetic resonance spectroscopic study of beta-lactoglobulin interactions with two flavor compounds, gamma-decalactone and beta-ionone.

    Science.gov (United States)

    Lübke, Markus; Guichard, Elisabeth; Tromelin, Anne; Le Quéré, Jean Luc

    2002-11-20

    Interactions between a well-characterized protein, beta-lactoglobulin, and two flavor compounds, beta-ionone and gamma-decalactone, were studied by 2D NMR spectroscopy. NMR spectra were recorded in aqueous solution (pH 2.0, 12 mM NaCl, 10% D(2)O) under conditions such that beta-lactoglobulin is present in a monomeric state. TOCSY and NOESY spectra were recorded on the protein and the complexes between protein and ligands. The spectra of the NH-CH(alpha) region showed the cross-signals due to the coupling between N- and C-bonded protons in the polypeptide backbone. The observed chemical shift variations in the presence of ligands can be assigned to changes in the protein conformation. It appears that the side chains of several amino acids are affected by binding of gamma-decalactone point into the central cavity (Leu46, Ile56, Met107, and Gln120), whereas binding of beta-ionone affects amino acids located in a groove near the outer surface of the protein (Leu104, Tyr120, and Asp129), as illustrated by molecular visualization. This NMR study provides precise information of the location of binding and confirms the existence of two different binding sites for aroma compounds on beta-lactoglobulin, which was suggested in previous competition studies by fluorometry or affinity chromatography and by structural information obtained from infrared spectroscopy. PMID:12428965

  12. Epoxidation of limonene over Ti MCM 41 and Ti BETA

    International Nuclear Information System (INIS)

    Ti MCM 41 were synthesized and evaluated in the epoxidation of limonene, using peroxide of hydrogen (H2O) as agent oxidizer. The characteristic hexagonal phase of Ti MCM 41 was obtained by heating the precursor gel during three days at 100 centigrade degrees. Further heating up to ten days leads to a decrease of this phase. The increase (Ti) in the synthesis gel also decreases that phase. The increase of Ti in the synthesis gel also decreases that phase UV VIS and FTIR spectroscopy indicates that Ti was incorporated in the lattice of Ti MCM 41 as well as, in Ti BETA. SEM micrographs of Ti MCM 41 show that the morphology changes with the Ti loading. Ti MCM 41 was most active than Ti BETA for limonene epoxidation even though both show high selectivity to epoxides

  13. Laser spectroscopy used in nuclear physics; La spectroscopie laser appliquee a la physique nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Le Blanc, F

    2001-04-05

    The study of nuclear shapes is a basic topic since it constitutes an excellent ground for testing and validating nuclear models. Measurements of the electron quadrupolar moment, of the nuclear charge radius and of the magnetic dipolar moment shed light on the nuclear deformation. Laser spectroscopy is a specific tool for such measurements, it is based on the interaction of the nucleus with the surrounding electron cloud (hyperfine structure), it is then an external approach of the shape of the nucleus whereas the classical nuclear spectroscopy ({alpha}, {beta} or {gamma}) gives information on the deformation from the inside of the nucleus. The author describes 2 techniques of laser spectroscopy: the colinear spectroscopy directly applied to a beam issued from an isotope separator and the resonant ionization spectroscopy linked with atom desorption that allows the study of particular nuclei. In order to illustrate both methods some effective measurements are presented: - the colinear spectroscopy has allowed the achievement of the complete description of the isomeric state (T = 31 years) of hafnium-178; - The experiment Complis has revealed an unexpected even-odd zigzag effect on very neutron-deficient platinum isotopes; and - the comparison of 2 isotopes of gold and platinum with their isomers has shown that the inversion of 2 levels of neutron, that was found out by nuclear spectroscopy, is in fact a consequence of a change in the nuclear shape. (A.C.)

  14. Chiroptical Spectroscopy

    Science.gov (United States)

    Gurst, Jerome E.

    1995-09-01

    A brief review of the literature, and Chemical and Engineering News in particular, reveals that the determination and use of optical activity is of increasing importance in today's commercial and research laboratories. The classical technique is to measure [alpha]D using a manual or recording polarimeter to provide a single value, the specific rotation at 589 nm. A spectropolarimeter can be used to determine optical activity through the UV-Visible spectrum (Optical Rotatory Dispersion [ORD]). At wavelengths far removed from electronic absorption bands, optical activity arises from circular birefringence, or the difference in the refractive index for left- and right-circularly polarized light; i.e., nL - nR does not equal zero for chiral materials. If the optical activity is measured through an absorption band, complex behavior is observed (a Cotton Effect curve). At an absorption band, chiral materials exhibit circular dichroism (CD), or a difference in the absorption of left- and right-circularly polarized light; epsilon L minus epsilon R does not equal zero. If the spectropolarimeter is set for the measurement of CD spectra, one observes what appears to be a UV-Vis spectrum except that some absorption bands are positive while others may be negative. Just as enantiomers have specific rotations that are equal and opposite at 589 nm (sodium D line), rotations are equal and opposite at all wavelengths, and CD measurements are equal and opposite at all wavelengths. Figure 1 shows the ORD curves for the enantiomeric carvones while Figure 2 contains the CD curves. The enantiomer of carvone that has the positive [alpha]D is obtained from caraway seeds and is known to have the S-configuration while the R-enantiomer is found in spearmint oil. Figure 1. ORD of S-(+)- and R-(-)-carvones Figure 2. CD of S-(+)- and R-(-)-carvones While little can be done to correlate stereochemistry with [alpha]D values, chiroptical spectroscopy (ORD and/or CD) often can be used to assign

  15. Inclusion complexation of novocaine by beta-cyclodextrin in aqueous solutions.

    Science.gov (United States)

    Iglesias, Emilia

    2006-06-01

    The formation of inclusion complexes between beta-cyclodextrin (beta-CD) and the local anesthetic 2-(diethylamino)ethyl-p-amino-benzoate (novocaine) in aqueous solutions under different acidity conditions, using steady-state fluorescence or UV-vis spectroscopies, electrical conductivity, or the kinetic study of both the nitrosation reaction of the primary amine group in a mild acid medium and the hydrolysis of the ester function under an alkaline medium, has been studied. The inclusion complex formation between neutral or protonated novocaine and beta-CD of 1:1 stoichiometry was observed; however, the magnitude of the binding constants depends on the nature of both the guest and the host, and the higher-affinity guest-host was found under conditions when both the novocaine and the beta-CD were neutral molecules.

  16. Study of the ${\\beta}$-decay of $^{12}$B

    CERN Multimedia

    2002-01-01

    We propose to study the ${\\beta}$-decay of $^{12}$B with a modern segmented Si-detector array to get new and much improved information on states in $^{12}$C above the ${\\alpha}$-threshold. These states mainly decay into final states of three ${\\alpha}$-particles and their study therefore is a challenge for nuclear spectroscopy. The properties of these states is of high current interest for nuclear astrophysics and for the nuclear many-body problem in general. We ask for a total of 15 shifts.

  17. Optical Spectroscopy of Four Young Radio Sources

    CERN Document Server

    Fan, Xu-Liang; Hu, Chen; Wang, Jian-Guo

    2016-01-01

    We report the optical spectroscopy of four young radio sources which are observed with the Lijiang 2.4m telescope. The Eddington ratios of these sources are similar with those of narrow-line Seyfert 1 galaxies (NLS1s). Their Fe {\\sc ii} emission is strong while [O {\\sc iii}] strength is weak. These results confirm the NLS1 features of young radio sources, except that the width of broad H$\\beta$ of young radio sources is larger than that of NLS1s. We thus suggest that the young radio sources are the high black hole mass counterparts of steep-spectrum radio-loud NLS1s. In addition, the broad H$\\beta$ component of \\astrobj{4C 12.50} is the blue wing of the narrow component, but not from the broad line region.

  18. Carbon-nitrogen place exchange on NO exposed beta-Mo2C.

    Science.gov (United States)

    Siaj, Mohamed; Maltais, Carl; Zahidi, El Mamoune; Oudghiri-Hassani, Hicham; Wang, Jiqing; Rosei, Federico; McBreen, Peter H

    2005-08-18

    Atomic nitrogen and oxygen were deposited on beta-Mo(2)C through dissociative adsorption of NO. Reflectance absorbance infrared spectroscopy (RAIRS), thermal desorption, and synchrotron X-ray photoelectron spectroscopy (XPS) measurements were used to investigate the interplay between atomic nitrogen, carbon, and oxygen in the 400-1250 K region. The combination of the high resolution and high surface sensitivity offered by the synchrotron XPS technique was used to show that atomic nitrogen displaces interstitial carbon onto the carbide surface. Thermal desorption measurements show that the burnoff of the displaced carbon occurs at approximately 890 K. The incorporation of nitrogen into interstitial sites inhibits oxygen dissolution into the bulk. RAIRS spectroscopy was used to identify surface oxo, terminal oxygen, species formed from O(2) and NO on beta-Mo(2)C.

  19. The microbial oxidation of (-)-beta-pinene by Botrytis cinerea.

    Science.gov (United States)

    Farooq, Afgan; Choudhary, M Iqbal; Tahara, Satoshi; Rahman, Atta-ur; Başer, K Hüsnü Can; Demirci, Fatih

    2002-01-01

    (-)-beta-pinene, a flavor and fragrance monoterpene is an important constituent of essential oils of many aromatic plants. It was oxidized by a plant-pathogenic fungus, Botrytis cinerea to afford four metabolites characterized as (-)-6a-hydroxy-beta-pinene, (-)-4beta,5beta-dihydroxy-beta-pinene, (-)-2beta,3beta-dihydroxypinane, and (-)-4beta-hydroxy-beta-pinene-6-one by detailed spectroscopic studies along with other known metabolites.

  20. Mechanism of inactivation of alanine racemase by beta, beta, beta-trifluoroalanine

    International Nuclear Information System (INIS)

    The alanine racemases are a group of PLP-dependent bacterial enzymes that catalyze the racemization of alanine, providing D-alanine for cell wall synthesis. Inactivation of the alanine racemases from the Gram-negative organism Salmonella typhimurium and Gram-positive organism Bacillus stearothermophilus with beta, beta, beta-trifluoroalanine has been studied. The inactivation occurs with the same rate constant as that for formation of a broad 460-490-nm chromophore. Loss of two fluoride ions per mole of inactivated enzyme and retention of [1-14C]trifluoroalanine label accompany inhibition, suggesting a monofluoro enzyme adduct. Partial denaturation (1 M guanidine) leads to rapid return of the initial 420-nm chromophore, followed by a slower (t1/2 approximately 30 min-1 h) loss of the fluoride ion and 14CO2 release. At this point, reduction by NaB3H4 and tryptic digestion yield a single radiolabeled peptide. Purification and sequencing of the peptide reveals that lysine-38 is covalently attached to the PLP cofactor. A mechanism for enzyme inactivation by trifluoroalanine is proposed and contrasted with earlier results on monohaloalanines, in which nucleophilic attack of released aminoacrylate on the PLP aldimine leads to enzyme inactivation. For trifluoroalanine inactivation, nucleophilic attack of lysine-38 on the electrophilic beta-difluoro-alpha, beta-unsaturated imine provides an alternative mode of inhibition for these enzymes

  1. Smart Beta or Smart Alpha

    DEFF Research Database (Denmark)

    Winther, Kenneth Lillelund; Steenstrup, Søren Resen

    2016-01-01

    Smart beta has become the flavor of the decade in the investment world with its low fees, easy access to rewarded risk premiums, and appearance of providing good investment results relative to both traditional passive benchmarks and actively managed funds. Although we consider it well documented......-documented smart beta risk premiums and still motivate active managers to avoid value traps, too highly priced small caps, defensives, etc. By constructing the equity portfolios of active managers that resemble the most widely used risk premiums, we show that the returns and risk-adjusted returns measures...

  2. Novel anthracycline-spacer-beta-glucuronide, -beta-glucoside, and -beta-galactoside prodrugs for application in selective chemotherapy

    NARCIS (Netherlands)

    Leenders, RGG; Damen, EWP; Bijsterveld, EJA; Scheeren, HW; Houba, PHJ; van der Meulen-Muileman, IH; Boven, E; Haisma, HJ

    1999-01-01

    A series of anthracycline prodrugs containing an immolative spacer was synthesized for application in selective chemotherapy. The prodrugs having the general structure anthracycline-spacer-beta-glycoside were designed to be activated by beta-glucuronidase or beta-galactosidase. Prodrugs with -chloro

  3. Constraining neutrinoless double beta decay

    International Nuclear Information System (INIS)

    A class of discrete flavor-symmetry-based models predicts constrained neutrino mass matrix schemes that lead to specific neutrino mass sum-rules (MSR). We show how these theories may constrain the absolute scale of neutrino mass, leading in most of the cases to a lower bound on the neutrinoless double beta decay effective amplitude.

  4. Beta Cell Workshop 2013 Kyoto

    DEFF Research Database (Denmark)

    Heller, R Scott; Madsen, Ole D; Nielsen, Jens Høiriis

    2013-01-01

    The very modern Kyoto International Conference Center provided the site for the 8th workshop on Beta cells on April 23-26, 2013. The preceding workshops were held in Boston, USA (1991); Kyoto, Japan (1994); Helsingør, Denmark (1997); Helsinki, Finland (2003); El Perello, Spain (2006); Peebles...

  5. Abstraction Mechanisms in the BETA Programming Language

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger;

    1983-01-01

    The BETA programming language is developed as part of the BETA project. The purpose of this project is to develop concepts, constructs and tools in the field of programming and programming languages. BETA has been developed from 1975 on and the various stages of the language are documented in [BETA...... a]. The application area of BETA is programming of embedded as well as distributed computing systems. For this reason a major goal has been to develop constructs that may be efficiently implemented. Furthermore the BETA language is intended to have a few number of basic but general constructs....... It is then necessary that the abstraction mechanisms are powerful in order to define more specialized constructs. BETA is an object oriented language like SIMULA 67 ([SIMULA]) and SMALLTALK ([SMALLTALK]). By this is meant that a construct like the SIMULA class/subclass mechanism is fundamental in BETA. In contrast...

  6. Neutron Beta Decay Studies with Nab

    CERN Document Server

    Baeßler, S; Alonzi, L P; Balascuta, S; Barrón-Palos, L; Bowman, J D; Bychkov, M A; Byrne, J; Calarco, J R; Chupp, T; Vianciolo, T V; Crawford, C; Frlež, E; Gericke, M T; Glück, F; Greene, G L; Grzywacz, R K; Gudkov, V; Harrison, D; Hersman, F W; Ito, T; Makela, M; Martin, J; McGaughey, P L; McGovern, S; Page, S; Penttilä, S I; Počanić, D; Rykaczewski, K P; Salas-Bacci, A; Tompkins, Z; Wagner, D; Wilburn, W S; Young, A R

    2012-01-01

    Precision measurements in neutron beta decay serve to determine the coupling constants of beta decay and allow for several stringent tests of the standard model. This paper discusses the design and the expected performance of the Nab spectrometer.

  7. How Do Beta Blocker Drugs Affect Exercise?

    Science.gov (United States)

    ... Stroke More How do beta blocker drugs affect exercise? Updated:Aug 5,2015 Beta blockers are a ... about them: Do they affect your ability to exercise? The answer can vary a great deal, depending ...

  8. The beta subunit of casein kinase II

    DEFF Research Database (Denmark)

    Boldyreff, B; Piontek, K; Schmidt-Spaniol, I;

    1991-01-01

    cDNAs encoding the beta subunit of pig and mouse CKII were isolated. The porcine cDNA was expressed as a fusion protein in Escherichia coli and used for the production of anti-CKII-beta subunit specific antibodies.......cDNAs encoding the beta subunit of pig and mouse CKII were isolated. The porcine cDNA was expressed as a fusion protein in Escherichia coli and used for the production of anti-CKII-beta subunit specific antibodies....

  9. Neoclassical transport in high [beta] tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Cowley, S.C.

    1992-12-01

    Neoclassical, transport in high [beta] large aspect ratio tokamaks is calculated. The variational method introduced by Rosenbluth, et al., is used to calculate the full Onsager matrix in the banana regime. These results are part of a continuing study of the high [beta] large aspect ratio equilibria introduced in Cowley, et al. All the neoclassical coefficients are reduced from their nominal low [beta] values by a factor ([var epsilon]/q[sup 2][beta])[sup [1/2

  10. Beta measurements at Department of Energy facilities

    International Nuclear Information System (INIS)

    Pacific Northwest Laboratory performed a two-step process to characterize the current beta measurement practices at DOE facilities. PNL issued a survey questionnaire on beta measurement practices to DOE facilities and reported the results. PNL measured beta doses and spectra at seven selected DOE facilities and compared selected measurement techniques in the facility environment. This report documents the results of the radiation field measurements and the comparison of measurement techniques at the seven facilities. Data collected included beta dose and spectral measurements at seven DOE facilities that had high beta-to-gamma ratios (using a silicon surface barrier spectrometer, a plastic scintillator spectrometer, and a multielement beta dosimeter). Other dosimeters and survey meters representative of those used at DOE facilities or under development were also used for comparison. Field spectra were obtained under two distinct conditions. Silicon- and scintillation-based spectrometer systems were used under laboratory conditions where high beta-to-gamma dose ratios made the beta spectra easier to observe and analyze. In the second case, beta spectrometers were taken into actual production and maintenance areas of DOE facilities. Analyses of beta and gamma spectra showed that 234Th- /sup 234m/Pa, 231Th, 137Cs, and 90Sr/90Y were the major nuclides contributing to beta doses at the facilities visited. Beta doses from other fission products and 60Co were also measured, but the potential for exposure was less significant. 21 refs., 64 figs., 18 tabs

  11. Basic molecular spectroscopy

    CERN Document Server

    Gorry, PA

    1985-01-01

    BASIC Molecular Spectroscopy discusses the utilization of the Beginner's All-purpose Symbolic Instruction Code (BASIC) programming language in molecular spectroscopy. The book is comprised of five chapters that provide an introduction to molecular spectroscopy through programs written in BASIC. The coverage of the text includes rotational spectra, vibrational spectra, and Raman and electronic spectra. The book will be of great use to students who are currently taking a course in molecular spectroscopy.

  12. Advances in atomic spectroscopy

    CERN Document Server

    Sneddon, J

    1997-01-01

    This series describes selected advances in the area of atomic spectroscopy. It is primarily intended for the reader who has a background in atmoic spectroscopy; suitable to the novice and expert. Although a widely used and accepted method for metal and non-metal analysis in a variety of complex samples, Advances in Atomic Spectroscopy covers a wide range of materials. Each Chapter will completely cover an area of atomic spectroscopy where rapid development has occurred.

  13. Advances in atomic spectroscopy

    CERN Document Server

    Sneddon, J

    1995-01-01

    This series describes selected advances in the area of atomic spectroscopy. It is promarily intended for the reader who has a background in atmoic spectroscopy; suitable to the novice and expert. Although a widely used and accepted method for metal and non-metal analysis in a variety of complex samples, Advances in Atomic Spectroscopy covers a wide range of materials. Each Chapter will completely cover an area of atomic spectroscopy where rapid development has occurred.

  14. Symposium on atomic spectroscopy

    International Nuclear Information System (INIS)

    Topics covered by the conference include: fast beam spectroscopy; astrophysical and other spectra; highly ionized spectroscopy; complex spectra; rydberg levels; fine structure, hyperfine structure and isotope shift; lineshapes; lifetimes, oscillator strengths and Einstein coefficients; and spectroscopy with lasers. Abstracts of the conference papers are presented

  15. Symposium on atomic spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    Topics covered by the conference include: fast beam spectroscopy; astrophysical and other spectra; highly ionized spectroscopy; complex spectra; rydberg levels; fine structure, hyperfine structure and isotope shift; lineshapes; lifetimes, oscillator strengths and Einstein coefficients; and spectroscopy with lasers. Abstracts of the conference papers are presented. (GHT)

  16. Measurement of the beta asymmetry in neutron beta decay

    International Nuclear Information System (INIS)

    Neutron beta decay is the simplest semi-leptonic weak decay and described accurately by the standard model using the first CKM-matrix element and the ratio of vector and axial vector couplings, λ. With more than a dozen observables it is a sensitive probe for investigating the nature of weak interaction and to search for physics beyond the standard model. In the past, measuring the beta asymmetry A in polarized neutron decay has been the most precise way of determining λ and nowadays it allows - together with other observables - to derive limits on non-standard model interactions, such as scalar and tensor couplings. The neutron decay spectrometer Perkeo III was installed at the PF1B cold neutron beam site at the Institut Laue-Langevin to measure the beta asymmetry. By using a pulsed beam combined with an improved detector design a significant reduction of several systematic uncertainties has been achieved compared to the predecessor, Perkeo II. In this talk recent results of the measurements with Perkeo III will be presented. In particular, we show the energy distribution of the electrons together with the calibration tools for the detectors.

  17. Study of neutron-rich $^{51−53}$ Ca isotopes via $\\beta$-decay

    CERN Multimedia

    The high Q$_\\beta$ values in certain neutron-rich regions of the chart of nuclides opens up the possibility to study states in the daughter nuclei which lie at high excitation energy, above the neutron separation threshold. We propose to perform spectroscopy of the $\\beta$-delayed neutron emission of the $^{51-53}$K isotopes to study the population of single-particle or particle-hole states both below and above the neutron separation threshold. The VANDLE neutron detector will be used in combination with the IDS tape station setup and Ge detectors.

  18. Cerebral oxygenation decreases during exercise in humans with beta-adrenergic blockade

    DEFF Research Database (Denmark)

    Seifert, T.; Rasmussen, P.; Secher, Niels H.;

    2009-01-01

    AIM: Beta-blockers reduce exercise capacity by attenuated increase in cardiac output, but it remains unknown whether performance also relates to attenuated cerebral oxygenation. METHODS: Acting as their own controls, eight healthy subjects performed a continuous incremental cycle test to exhaustion...... with or without administration of the non-selective beta-blocker propranolol. Changes in cerebral blood flow velocity were measured with transcranial Doppler ultrasound and those in cerebral oxygenation were evaluated using near-infrared spectroscopy and the calculated cerebral mitochondrial oxygen...

  19. Enzyme-catalyzed ring-opening polymerization of unsubstituted beta-lactam

    OpenAIRE

    Schwab, Leendert W.; Kroon, Renee; Schouten, Arend Jan; Loos, Katja

    2008-01-01

    The synthesis of poly(beta-alanine) by Candida antarctica lipase B immobilized as novozyme 435 catalyzed ring-opening of 2-azetidinone is reported. After removal of cyclic side products and low molecular weight species pure linear poly(beta-alanine) is obtained. The formation of the polymer is confirmed with (1)H NMR spectroscopy and MALDI-TOF mass spectrometry. The average degree of polymerization of the obtained polymer is limited to DP=8 by its solubility in the reaction medium. Control ex...

  20. Modification of polyethylene films by radiation grafting of glycidyl methacrylate and immobilization of {beta}-cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Nava-Ortiz, C.A.B. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Burillo, G. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico)], E-mail: burillo@nucleares.unam.mx; Bucio, E. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Alvarez-Lorenzo, C. [Departamento de Farmacia y Tecnologia Farmaceutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2009-01-15

    Glycidyl methacrylate was grafted onto polyethylene films using a preirradiation method with {gamma} rays. The effect of absorbed dose, monomer concentration, and reaction time on the degree of grafting was determined. The grafted samples were verified by FTIR-ATR spectroscopy. {beta}-Cyclodextrin was immobilized onto polypropylene modified with glycidyl methacrylate, and the ability of the cavities of {beta}-cyclodextrin to form inclusion complexes was demonstrated using the typically organic compound approach with m-toluic acid (3-MBA) as a probe.

  1. Zirconium metal--water oxidation kinetics. II. Oxygen-18 diffusion in. beta. -Zircaloy

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, R.A.

    1976-07-01

    The diffusion of oxygen-18 in ..beta..-Zircaloy-4 was measured from 900 to 1500/sup 0/C and survey measurements were made for ..beta..-zirconium and ..beta..-Zircaloy-2. The tracer diffusivity was measured over the entire temperature range and the chemical diffusivity from 1100 to 1500/sup 0/C. The experiments were performed by using oxygen-18 as the tracer and activating it by proton bombardment. Complementary measurements were also made using Auger Electron Spectroscopy. Results indicated that the tracer and chemical diffusivity of oxygen in ..beta..-Zircaloy-4 are statistically identical, and there is no oxygen concentration dependence over the oxygen concentration range studied, 0.1 to 0.6 wt percent. The temperature dependence of the diffusivity from 1000 to 1500/sup 0/C is D = 2.48 x 10/sup -2/ exp (-28200/RT) cm/sup 2//s. Below 1000/sup 0/C, the diffusivity dropped sharply because a two-phase ..cap alpha.. + ..beta.. mixture was present. Results for the ..beta..-Zircaloy-2 and ..beta..-zirconium indicated that the alloying additions have no influence upon the oxygen diffusivity. Combination of three sets of boundary conditions (thin-film tracer diffusion, single-phase chemical diffusion couple, and phase-boundary-movement chemical diffusion couple) and two methods of oxygen profiling (oxygen-18 radioactivation and Auger Electron Spectroscopy) were used to increase the confidence in the results. Current results are about 50 percent lower than the previous results of Mallett, Albrecht, and Wilson. The diffusivity of oxygen-16 is expected to be 6 percent greater than that for oxygen-18. (auth)

  2. Beta thalassaemia mutations in Turkish Cypriots.

    OpenAIRE

    Sozuoz, A; Berkalp, A; A. Figus; Loi, A; Pirastu, M.; Cao, A

    1988-01-01

    Using oligonucleotide hybridisation or restriction endonuclease analysis, we have characterised the molecular defect in 94 patients with thalassaemia major and four with thalassaemia intermedia of Turkish Cypriot descent. We found that four mutations, namely beta+ IVS-1 nt 110, beta zero IVS-1 nt, beta+ IVS-1 nt 6, and beta+ IVS-2 nt 745 were prevalent, accounting for 69.9%, 11.7%, 8.7%, and 5.6% respectively of the beta thalassaemia chromosomes. This information may help in the organisation ...

  3. Coherent Raman spectroscopy

    CERN Document Server

    Eesley, G L

    1981-01-01

    Coherent Raman Spectroscopy provides a unified and general account of the fundamental aspects of nonlinear Raman spectroscopy, also known as coherent Raman spectroscopy. The theoretical basis from which coherent Raman spectroscopy developed is described, along with its applications, utility, and implementation as well as advantages and disadvantages. Experimental data which typifies each technique is presented. This book is comprised of four chapters and opens with an overview of nonlinear optics and coherent Raman spectroscopy, followed by a discussion on nonlinear transfer function of matter

  4. Investigation of de novo cholesterol synthetic capacity in the gonads of goldfish (Carassius auratus exposed to the phytosterol beta-sitosterol

    Directory of Open Access Journals (Sweden)

    MacLatchy Deborah L

    2006-11-01

    Full Text Available Abstract Total and intra-mitochondrial gonadal cholesterol concentrations are decreased in fish exposed to the phytoestrogen beta-sitosterol (beta-sit. The present study examined the potential for beta-sit to disrupt de novo cholesterol synthesis in the gonads of goldfish exposed to 200 microgram/g beta-sit and 10 microgram/g 17beta-estradiol (E2; estrogenic control by intra-peritoneal Silastic® implants for 21 days. The de novo cholesterol synthetic capacity was estimated by incubating gonadal tissue with 14C-acetate for a period of 18 hours, followed by chloroform/methanol lipid extraction and thin layer chromatography (TLC lipid separation. Lipid classes were confirmed using infrared spectroscopy. Plasma testosterone (T and total cholesterol concentration were measured and gonadosomatic index (GSI was calculated. Plasma T was significantly reduced in male beta-sit-treated fish compared to control and E2-treated fish (p

  5. Plan beta: Core or Cusp?

    CERN Document Server

    Richardson, Thomas; Lehnert, Matt

    2013-01-01

    The inner profile of Dark Matter (DM) halos remains one of the central problems in small-scale cosmology. At present, the problem can not be resolved in dwarf spheroidal galaxies due to a degeneracy between the DM profile and the velocity anisotropy beta of the stellar population. We discuss a method which can break the degeneracy by exploiting 3D positions and 1D line-of-sight (LOS) velocities. With the full 3D spatial information, we can determine precisely what fraction of each stars LOS motion is in the radial and tangential direction. This enables us to infer the anisotropy parameter beta directly from the data. The method is particularly effective if the galaxy is highly anisotropic. Finally, we argue that such a test could be applied to Sagittarius and potentially other dwarfs with RR Lyrae providing the necessary depth information.

  6. Beta spectrum of 185W

    International Nuclear Information System (INIS)

    The measurement of the shape of the first forbidden beta transition of 185W is interesting from the point of view of the fact that this nucleus belongs to the deformed region 150185W is carried out employing an optimized Siegbahn-Slatis beta ray spectrometer and the result is compared with the theoretical shape factor incorporating Nilsson's wavefunctions using Simms formalism. The experimental shape factor is fitted to the correction factor C(W)=k(1+aW) with α=0.0026+-0.0432. The theoretical shape factor computed following the matrix elements due to Nilsson model is in good agreement with the present experimental shape factor. The value Λ(2.358) computed in the present measurement in the light of Nilsson model matrix elements of 185W is in agreement with the predicted value (2.4) of J.J. Fujita. (author)

  7. Advances in atomic spectroscopy

    CERN Document Server

    Sneddon, J

    2000-01-01

    This fifth volume of the successful series Advances in Atomic Spectroscopy continues to discuss and investigate the area of atomic spectroscopy.It begins with a description of the use of various atomic spectroscopic methods and applications of speciation studies in atomic spectroscopy. The emphasis is on combining atomic spectroscopy with gas and liquid chromatography. In chapter two the authors describe new developments in tunable lasers and the impact they will have on atomic spectroscopy. The traditional methods of detection, such as photography and the photomultiplier, and how they are being replaced by new detectors is discussed in chapter three. The very active area of glow discharge atomic spectrometry is presented in chapter four where, after a brief introduction and historical review, the use of glow discharge lamps for atomic spectroscopy and mass spectrometry are discussed. Included in this discussion is geometry and radiofrequency power. The future of this source in atomic spectroscopy is also dis...

  8. Review of double beta experiments

    OpenAIRE

    Sarazin, X.

    2012-01-01

    C13-10-22.1 International audience This paper gives a review of the double beta experimental techniques and projects, in the search for the Majorana neutrino. The purpose of this review is to detail, for each technique, the different origins of background, how they can be identified, and how they can be reduced. Advantages and limitations of the different techniques are discussed. 1. Introduction The neutrino is one of the most puzzling elementary particle with very unique properties. I...

  9. Myokardinfarkt und Beta-Blocker

    Directory of Open Access Journals (Sweden)

    Stühlinger H-G

    2003-01-01

    Full Text Available Im Rahmen eines akuten koronaren Syndroms (akuter Herzinfarkt, Angina pectoris kommt es, aufgrund eines Ungleichgewichtes zwischen Angebot und Bedarf, zu einem akuten Mangel an Sauerstoff im Herzmuskel. Ursache ist eine reduzierte Sauerstoffzufuhr durch verengte bzw. verschlossene Gefäße. Bis zur Behebung der Ursache vergehen oft mehrere Stunden. In dieser Phase muß - durch Verminderung des Sauerstoffbedarfs im Herzmuskel - eine Verlangsamung der Nekroseentwicklung erreicht werden. Das Ausmaß der Nekrose wird reduziert, somit die für die Langzeitprognose wichtige Linksventrikelfunktion verbessert. Eine Verminderung des Sauerstoffbedarfs erreicht man durch kontrollierte Frequenzsenkung mittels intravenöser Beta-Blockade. In optimaler Weise wird diese Methode durch die Anwendung eines kardioselektiven Beta-Blockers mit kurzer Halbwertszeit durchgeführt. Beta-Blocker haben nicht nur auf die Nekroseentwicklung, sondern auch auf die Inzidenz von Rhythmusstörungen - besonders in der Akutphase - Auswirkungen. Vor allem die mit dieser therapeutischen Maßnahme verbundene Reduktion von Kammerflimmern ist von großer Bedeutung.

  10. COMPLIS: COllinear spectroscopy Measurements using a Pulsed Laser Ion Source

    CERN Multimedia

    2002-01-01

    A Pulsed Laser spectroscopy experiment has been installed for the study of hyperfine structure and isotope shift of refractory and daughter elements from ISOLDE beams. It includes decelerated ion-implantation, element-selective laser ionization, magnetic and time-of-flight mass separation. The laser spectroscopy has been performed on the desorbed atoms in a set-up at ISOLDE-3 but later on high resolution laser collinear spectroscopy with the secondary pulsed ion beam is planned for the Booster ISOLDE set-up. During the first operation time of ISOLDE-3 we restricted our experiments to Doppler-limited resonant ionization laser and $\\gamma$-$\\gamma$ nuclear spectroscopy on neutron deficient platinum isotopes of even mass number down to A~=~186 and A~=~179 respectively. These isotopes have been produced by implantation of radioactive Hg and their subsequent $\\beta$-decay.

  11. The Structure of the Amyloid-[beta] Peptide High-Affinity Copper II Binding Site in Alzheimer Disease

    Energy Technology Data Exchange (ETDEWEB)

    Streltsov, Victor A.; Titmuss, Stephen J.; Epa, V. Chandana; Barnham, Kevin J.; Masters, Colin L.; Varghese, Joseph N. (CSIRO/MHT)

    2008-11-03

    Neurodegeneration observed in Alzheimer disease (AD) is believed to be related to the toxicity from reactive oxygen species (ROS) produced in the brain by the amyloid-{beta} (A{beta}) protein bound primarily to copper ions. The evidence for an oxidative stress role of A{beta}-Cu redox chemistry is still incomplete. Details of the copper binding site in A{beta} may be critical to the etiology of AD. Here we present the structure determined by combining x-ray absorption spectroscopy (XAS) and density functional theory analysis of A{beta} peptides complexed with Cu{sup 2+} in solution under a range of buffer conditions. Phosphate-buffered saline buffer salt (NaCl) concentration does not affect the high-affinity copper binding mode but alters the second coordination sphere. The XAS spectra for truncated and full-length A{beta}-Cu{sup 2+} peptides are similar. The novel distorted six-coordinated (3N3O) geometry around copper in the A{beta}-Cu{sup 2+} complexes include three histidines: glutamic, or/and aspartic acid, and axial water. The structure of the high-affinity Cu{sup 2+} binding site is consistent with the hypothesis that the redox activity of the metal ion bound to A{beta} can lead to the formation of dityrosine-linked dimers found in AD.

  12. [Study on the inclusion compound of avermectin by infrared spectroscopy].

    Science.gov (United States)

    Shen, Wen; Zhang, Guang-Hua; Guo, Ning; Li, Yun-Tao

    2014-05-01

    This study was designed to investigate the formation and effect of inclusion complex of Avermectin-beta-cyclodextrin based on the accommodation property of beta-cyclodextrin's molecular cavity. The inclusion complex of Averrnectin-beta-cyclodextrin was prepared using saturated solution method and high performance liquid chromatography (HPLC) was employed to determine its entraping efficiency. The formation of Avermectin-beta-cyclodextrin inclusion complex was also demonstrated by infrared spectroscopy(IR). The change of chemical structure produced by photocatalysis of Abamectin was analyzed and the effect of inclusion complex to strengthen the photolysis stability of Abamectin's chemical structure was studied. The results show that the entraping efficiency of the inclusion complex was 40. 5%. The IR analysis presents that the intermolecular hydrogen bond was formed in the Avermectin-beta-cyclodextrin inclusion complex, indicating the composition effect was different from physical mixture. The lactones structure of Avermectin Bla can be photodecomposed and disrupted. After decomposition, the infrared stretching vibration peak of C-O-C structure disappeared and the lactone bond was significantly broken. The lactones structure of avermectin Bla was covered by the inclusion molecular loci in beta-cyclodextrin after the formation of avermectin-beta-cyclodextrin inclusion complex, providing a good photophobic protection for C-O-C structure in the macrocyclic lactone structure of avermectin Bla and improving the photostability of avermectin Bla molecule. The innovation of this study is that the structure and the characters of the prepared avermectin-beta-cyclodextrin inclusion complex were analyzed using spectrum methods. This inclusion complex is expected to be the ideal intermediate in the construction of protective controlled release formulation of avermectin. PMID:25095407

  13. DMPD: Immunoreceptor-like signaling by beta 2 and beta 3 integrins. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17913496 Immunoreceptor-like signaling by beta 2 and beta 3 integrins. Jakus Z, Fod...) Show Immunoreceptor-like signaling by beta 2 and beta 3 integrins. PubmedID 17913496 Title Immunoreceptor-like signaling by beta... 2 and beta 3 integrins. Authors Jakus Z, Fodor S, Abram CL

  14. Single electron detection and spectroscopy via relativistic cyclotron radiation

    CERN Document Server

    Asner, D M; de Viveiros, L; Doe, P J; Fernandes, J L; Fertl, M; Finn, E C; Formaggio, J A; Furse, D; Jones, A M; Kofron, J N; LaRoque, B H; Leber, M; McBride, E L; Miller, M L; Mohanmurthy, P; Monreal, B; Oblath, N S; Robertson, R G H; Rosenberg, L J; Rybka, G; Rysewyk, D; Sternberg, M G; Tedeschi, J R; Thummler, T; VanDevender, B A; Woods, N L

    2014-01-01

    It has been understood since 1897 that accelerating charges must emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. Here we demonstrate single-electron detection in a novel radiofrequency spec- trometer. We observe the cyclotron radiation emitted by individual magnetically-trapped electrons that are produced with mildly-relativistic energies by a gaseous radioactive source. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta elec- tron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work demonstrates a fundamentally new approach to precision beta sp...

  15. Spectroscopy with cold and ultra-cold neutrons

    CERN Document Server

    Abele, Hartmut; Konrad, Gertrud

    2014-01-01

    We present two new types of spectroscopy methods for cold and ultra-cold neutrons. The first method, which uses the \\RB drift effect to disperse charged particles in a uniformly curved magnetic field, allows to study neutron $\\beta$-decay. We aim for a precision on the 10$^{-4}$ level. The second method that we refer to as gravity resonance spectroscopy (GRS) allows to test Newton's gravity law at short distances. At the level of precision we are able to provide constraints on any possible gravity-like interaction. In particular, limits on dark energy chameleon fields are improved by several orders of magnitude.

  16. Beta-dosimetry studies at LLNL

    International Nuclear Information System (INIS)

    This paper summarizes three beta-dosimetry studies made recently at the Lawrence Livermore National Laboratory. The first study was to determine the beta-gamma exposure rates at the Los Alamos Godiva IV Critical Assembly. The beta spectra from the assembly were evaluated using absorption curves and the beta-gamma dose-rate ratios were determined at various distances from the assembly. A comparison was made of the doses determined using two types of TLD personnel dosimeters and a film badge. The readings of an Eberline RO-7 instrument and the dose rates determined by TLDs were compared. Shielding provided by various metals, gloves, and clothing were measured. The second study was to determine the beta energy response of the Eberline RO-7 instrument based on measurements made with the PTB beta sources. This study required additional calibration points for the PTB sources which were made using extrapolation chamber measurements. The third study resulted in two techniques to determine the beta energy (E/sub max/) from the readings of this-window portable survey instruments. Both techniques are based on the readings obtained using aluminium filters. One technique is for field application, requires one filter, and provides a quick estimate of the beta energy in three energy groups: 1.5 MeV. The second technique is more complex requiring measurements with two or three filters, but gives the beta energy and the approximate shape of the beta spectrum. 9 references, 6 figures

  17. Investigation of de novo cholesterol synthetic capacity in the gonads of goldfish (Carassius auratus) exposed to the phytosterol beta-sitosterol.

    Science.gov (United States)

    Sharpe, Rainie L; Drolet, Melissa; MacLatchy, Deborah L

    2006-11-21

    Total and intra-mitochondrial gonadal cholesterol concentrations are decreased in fish exposed to the phytoestrogen beta-sitosterol (beta-sit). The present study examined the potential for beta-sit to disrupt de novo cholesterol synthesis in the gonads of goldfish exposed to 200 microgram/g beta-sit and 10 microgram/g 17beta-estradiol (E2; estrogenic control) by intra-peritoneal Silastic implants for 21 days. The de novo cholesterol synthetic capacity was estimated by incubating gonadal tissue with 14C-acetate for a period of 18 hours, followed by chloroform/methanol lipid extraction and thin layer chromatography (TLC) lipid separation. Lipid classes were confirmed using infrared spectroscopy. Plasma testosterone (T) and total cholesterol concentration were measured and gonadosomatic index (GSI) was calculated. Plasma T was significantly reduced in male beta-sit-treated fish compared to control and E2-treated fish (p fatty acids (FFA). FFA incorporation was significantly higher in male control fish than either beta-sit or E2 treatments (p = 0.005). Plasma cholesterol concentration was significantly increased in the male beta-sit treatment group compared to controls (p = 0.027). These results indicate gonadal de novo cholesterol biosynthetic capacity is not disrupted by beta-sit or E2 treatment in early recrudescing male or female goldfish, while plasma cholesterol and steroid concentrations are sensitive to beta-sit exposure.

  18. Slow formation of aggregation-resistant beta-sheet folding intermediates.

    Science.gov (United States)

    Junker, Mirco; Clark, Patricia L

    2010-03-01

    Protein folding has been studied extensively for decades, yet our ability to predict how proteins reach their native state from a mechanistic perspective is still rudimentary at best, limiting our understanding of folding-related processes in vivo and our ability to manipulate proteins in vitro. Here, we investigate the in vitro refolding mechanism of a large beta-helix protein, pertactin, which has an extended, elongated shape. At 55 kDa, this single domain, all-beta-sheet protein allows detailed analysis of the formation of beta-sheet structure in larger proteins. Using a combination of fluorescence and far-UV circular dichroism spectroscopy, we show that the pertactin beta-helix refolds remarkably slowly, with multiexponential kinetics. Surprisingly, despite the slow refolding rates, large size, and beta-sheet-rich topology, pertactin refolding is reversible and not complicated by off-pathway aggregation. The slow pertactin refolding rate is not limited by proline isomerization, and 30% of secondary structure formation occurs within the rate-limiting step. Furthermore, site-specific labeling experiments indicate that the beta-helix refolds in a multistep but concerted process involving the entire protein, rather than via initial formation of the stable core substructure observed in equilibrium titrations. Hence pertactin provides a valuable system for studying the refolding properties of larger, beta-sheet-rich proteins, and raises intriguing questions regarding the prevention of aggregation during the prolonged population of partially folded, beta-sheet-rich refolding intermediates. Proteins 2010. (c) 2009 Wiley-Liss, Inc. PMID:19847915

  19. Beta

    Science.gov (United States)

    This chapter covers the use of wild beets in sugar beet improvement, including the basic botany of the species, its distribution; geographical locations of genetic diversity; morphology; cytology and karyotype; genome size; taxonomic position; agricultural status (model plant/weeds/invasive species/...

  20. Binding of transforming growth factor-beta (TGF-beta) to pregnancy zone protein (PZP). Comparison to the TGF-beta-alpha 2-macroglobulin interaction.

    Science.gov (United States)

    Philip, A; Bostedt, L; Stigbrand, T; O'Connor-McCourt, M D

    1994-04-15

    Pregnancy zone protein (PZP) is quantitatively the most important pregnancy-associated plasma protein and it has strong similarity to alpha 2-macroglobulin. Since alpha 2-macroglobulin is a binding protein for transforming growth factors-beta (TGF-beta), it was of interest to test whether the related protein, PZP, also binds to these growth-regulatory proteins. Using affinity-labelling methods, we demonstrate that PZP binds both TGF-beta 1 and TGF-beta 2 and that the binding characteristics are similar to those of the TGF-beta-alpha 2-macroglobulin interaction. TGF-beta 2 and TGF-beta 1 bind to PZP in a predominantly noncovalent manner in vitro. TGF-beta 1 and TGF-beta 2 bind to both the dimeric and tetrameric forms of PZP. Our studies also indicate that PZP binds TGF-beta 2 with higher affinity than TGF-beta 1. Finally, we demonstrate that PZP inhibits the binding of TGF-beta 1 and TGF-beta 2 to their cell surface receptors. The increased level of PZP during pregnancy may affect the action of TGF-beta by regulating the distribution, clearance and/or general availability of TGF-beta. The preferential binding of TGF-beta 2 over TGF-beta 1 by PZP implies that PZP may differentially regulate the action of TGF-beta 1 and TGF-beta 2.

  1. On gaps in Rényi $\\beta$-expansions of unity for $\\beta > 1$ an algebraic number.

    OpenAIRE

    Verger-Gaugry, Jean-Louis

    2006-01-01

    Let $\\beta> 1$ be an algebraic number. We study the strings of zeros (“gaps”) in the Rényi $\\beta$ -expansion $d_{\\beta}(1)$ of unity which controls the set $\\mathbb{Z}_{\\beta}$ of $\\beta$-integers. Using a version of Liouville's inequality which extends Mahler's and Güting's approximation theorems, the strings of zeros in $d_{\\beta}(1)$ are shown to exhibit a “gappiness” asymptotically bounded above by $log(M(\\beta ))/ log(\\beta)$, where $M(\\beta)$ is the Mahler measure of $\\beta$ . The proo...

  2. Ultrahigh spatiotemporal resolved spectroscopy

    Institute of Scientific and Technical Information of China (English)

    LI; Zhi

    2007-01-01

    We review the technique and research of the ultrahigh spatiotemporal resolved spectroscopy and its applications in the field of the ultrafast dynamics of mesoscopic systems and nanomaterials. Combining femtosecond time-resolved spectroscopy and scanning near-field optical microscopy (SNOM), we can obtain the spectra with ultrahigh temporal and spatial resolutions simultaneously. Some problems in doing so are discussed. Then we show the important applications of the ultrahigh spatiotemporal resolved spectroscopy with a few typical examples.……

  3. TEM study of {beta}' precipitation in NiAl-Ti alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, A.W.; Howe, J.M. [Virginia Univ., Charlottesville, VA (United States). Dept. of Materials Science; Garg, A.; Noebe, R.D. [NASA Glenn Research Center, 21000 Brookpark Road, 44135, Cleveland, OH (United States)

    2000-09-30

    The precipitation of {beta}'-Ni{sub 2}AlTi has been investigated in NiAl-Ti alloys as a function of Ti concentration and aging treatment. The precipitation mechanism for {beta}' is nucleation and growth in these alloys for the given heat treatments. The solubility of Ti has been measured using quantitative energy-dispersive X-ray spectroscopy. These measurements agree with the results and trends of other researchers, and show the solubility of Ti decreases with temperature to 2.7 at.% at 1000 K. Comparisons to other studies of {beta}' precipitation in the Ni-Al-Ti system are made and conditions under which possible mechanisms can occur are discussed. (orig.)

  4. Study of octupole deformation in n-rich Ba isotopes populated via $\\beta$-decay

    CERN Multimedia

    We propose to exploit the unique capability of the ISOLDE facility to produce $^{150, 151, 152}$Cs beams to investigate their radioactive $\\beta$-decay to $^{150, 151, 152}$Ba. The interest to study this mass region is twofold: these nuclei are expected to show octupole deformations already in their low-lying state, secondly information on the $\\beta$-decay is needed for the nuclear astrophysical model. The experiment will be performed with the ISOLDE Decay Station (IDS) setup using the fast tape station of K.U.-Leuven, equipped with four Clover Germanium detectors, four LaBr$_{3}$(Ce) detectors and one LEP HPGe detector. Information on the $\\beta$-decay, such as lifetimes and delayed neutron-emission probabilities, will be extracted, together with the detailed spectroscopy of the daughter nuclei, via $\\gamma$-$\\gamma$-coincidences and lifetime measurement of specific states.

  5. pH dependent in-out isomerism of an amino-beta-cyclodextrin derivative.

    Science.gov (United States)

    Alcalde, Mercedes Alvarez; Gancedo, Cristina; Jover, Aida; Carrazana, Jorge; Soto, Victor H; Meijide, Francisco; Tato, José Vazquez

    2006-07-13

    An amino derivative of beta-cyclodextrin [6-(6-aminehexanamide)-6-deoxy)-beta-cyclodextrin (6-betaCD)] was synthesized, and the formation of an intramolecular inclusion complex was studied by NMR techniques. The deprotonation/protonation of the amino group stimulates an in/out movement of the pendant group toward/from the cyclodextrin cavity, the protonated species lying outside the hydrophobic cyclodextrin cavity but the unprotonated one residing inside and outside the cavity. The protonation of the amino group is a fast exchange rate NMR time-scale process, but the chain movement is a slow one. The equilibrium constants of both processes were determined from 1H NMR experiments and the kinetic constants for the slow process were determined from exchange spectroscopy (EXSY) experiments. PMID:16821861

  6. Influence of the aluminium impregnation [ Al(NO33] in the beta zeolite over its acidity

    Directory of Open Access Journals (Sweden)

    Francisco José Sánchez Castellanos

    2010-04-01

    Full Text Available Beta zeolite was impregnated with [ Al(NO33], increasing the aluminium content in increments of 0.05% from 0.00% to 0.25%. A parallel treatment with 0.05% sulphuric acid was also performed; in both cases, methanol was used as solvent (disperse phase. Cation exchange capacity (CEC, ammonia chemisorption, infrared spectroscopy (FIT-IR, scanning electronic microscopy (SEM, X-Ray powder diffraction (XRD, atomic absorption spectroscopy (AAS, titration with sodium hydroxide and nitrogen physisorption at 77K were used to carry out the physical and chemical characterization of the catalysts. Futhermore, the catalysts were employed in the esterification of ethanol with acetic acid, to quantify the effect of aluminium impregnation over the beta zeolite.

  7. Resistance training & beta-hydroxy-beta-methylbutyrate supplementation on hormones

    Directory of Open Access Journals (Sweden)

    Hamid Arazi

    2015-10-01

    Full Text Available RESUMOIntroduction:In recent years, there was an increased interest on the effects of beta-hydroxy-beta-methylbutyrate (HMB supplementation on skeletal muscle due to its anti-catabolic effects.Objectives:To investigate the effect of HMB supplementation on body composition, muscular strength and anabolic-catabolic hormones after resistance training.Methods:Twenty amateur male athletes were randomly assigned to supplement and control groups in a double-blind crossover design and participated in four weeks resistance training. Before and after the test period fasting blood samples were obtained to determine anabolic (the growth hormone and testosterone and catabolic (cortisol hormones, and fat mass, lean body mass (LBM and muscular strength were measured. Dependent and independent t-tests were used to analyze data.Results:After the training period, there were no significant differen-ces between the groups with respect to fat mass, LBM and anabolic-catabolic hormones. HMB supplementation resulted in a significantly greater strength gain (p≤0.05.Conclusion:Greater increase in strength for HMB group was not accompanied by body composition and basal circulating anabolic-catabolic hormonal changes. It seems that HMB supplementation may have beneficial effects on neurological adaptations of strength gain.

  8. Spectroscopy for Dummies

    DEFF Research Database (Denmark)

    Lindvold, Lars René

    This presentation will give short introduction to the most pertinent topics of optical spectroscopy. The following topics will be discussed: • The origin of spectra in UV, VIS and IR spectral range • Spectroscopic methods like absorption, luminescence and Raman • Wavelength dispersive optical...... components • Materials for use optical spectroscopy • Spectrometer geometries • Detectors for use in spectrometer • Practical examples of optical spectroscopy The objective of this presentation is to give the audience a good feel for the range of possibilities that optical spectroscopy can provide....

  9. GSK3beta is involved in JNK2-mediated beta-catenin inhibition.

    Directory of Open Access Journals (Sweden)

    Dong Hu

    Full Text Available BACKGROUND: We have recently reported that mitogen-activated protein kinase (MAPK JNK1 downregulates beta-catenin signaling and plays a critical role in regulating intestinal homeostasis and in suppressing tumor formation. This study was designed to determine whether JNK2, another MAPK, has similar and/or different functions in the regulation of beta-catenin signaling. METHODOLOGY AND PRINCIPAL FINDINGS: We used an in vitro system with manipulation of JNK2 and beta-catenin expression and found that activated JNK2 increased GSK3beta activity and inhibited beta-catenin expression and transcriptional activity. However, JNK2-mediated downregulation of beta-catenin was blocked by the proteasome inhibitor MG132 and GSK3beta inhibitor lithium chloride. Moreover, targeted mutations at GSK3beta phosphorylation sites (Ser33 and Ser37 of beta-catenin abrogated JNK2-mediated suppression of beta-catenin. In vivo studies further revealed that JNK2 deficiency led to upregulation of beta-catenin and increase of GSK3-beta phosphorylation in JNK2-/- mouse intestinal epithelial cells. Additionally, physical interaction and co-localization among JNK2, beta-catenin and GSK3beta were observed by immunoprecipitation, mammalian two-hybridization assay and confocal microscopy, respectively. CONCLUSION AND SIGNIFICANCE: In general, our data suggested that JNK2, like JNK1, interacts with and suppresses beta-catenin signaling in vitro and in vivo, in which GSK3beta plays a key role, although previous studies have shown distinct functions of JNK1 and JNK2. Our study also provides a novel insight into the crosstalk between Wnt/beta-catenin and MAPK JNKs signaling.

  10. Hyper-beta-alaninemia associated with beta-aminoaciduria and gamma-aminobutyricaciduaia, somnolence and seizures.

    Science.gov (United States)

    Scriver, C R; Pueschel, S; Davies, E

    1966-03-24

    Hyper-beta-alaninemia was found in a somnolent, convulsing infant. Hyper-beta-aminoaciduria (beta-ala, betaAIB and taurine) was also observed, varying directly with plasma beta-alanine concentration. The beta-aminoaciduria is explained by the interaction between beta-alanine and a specific cellular-transport system with preference for beta-amino compounds. Gamma-aminobutyricaciduria was also observed, its excretion being independent of beta-alanine levels. Dietary modifications, pyridoxine, pantothenic acid and antibiotic therapy were not beneficial. Post-mortem tissues had elevated levels of beta-alanine and carnosine; GABA levels in brain were probably elevated for the age of the patient. A proposed block in beta-alanine-alpha-ketoglutarate transaminase would expand the free beta-alanine pool, thus increasing tissue carnosine. beta-Alanine is a central-nervous-system depressant. Associated inhibition of GABA transaminase and displacement of GABA from central-nervous-system binding sites would produce GABAuria and convulsions. PMID:17926374

  11. Beta-2-mikroglobulin ved medicinske sygdomme

    DEFF Research Database (Denmark)

    Hansen, P B; Olsen, Niels Vidiendal

    1989-01-01

    Beta-2-microglobulin (beta 2M) is a low-molecular protein which is filtered freely over the glomeruli. Under normal circumstances, more than 99.9% is resorbed in the proximal tubuli of the kidneys and is metabolized there. In renal disease with damage to this segment of the nephron, eg acute tubulo......-interstitial nephropathy, increased quantities of beta 2M are excreted in the urine. If the rate of glomerular filtration is reduced, serum-beta 2M is increased and this is also the case in persons with increased cell division despite normal renal function. Serum-beta 2M is, therefore, raised in numerous malignant...... diseases and reflects the size of the tumour mass. During cytostatic treatment of myelomatosis and chronic lymphatic leukaemia, the serum-beta 2M levels decrease on remission and increase on relapse. In acute leukaemia and malignant lymphoma with infiltration of the CNS, similar conditions prevail for CSF...

  12. Hypersomnolence with beta-adrenergic blockers.

    Science.gov (United States)

    Thachil, J; Zeller, J R; Kochar, M S

    1987-11-01

    An elderly, mildly demented, hypertensive male patient developed hypersomnolence on administration of propranolol for treatment of hypertension; no other cause for hypersomnolence was detected. Upon replacement of propranolol with atenolol, he felt better but continued to be quite somnolent. When atenolol was discontinued, he reported to have lack of sleep. On readministration of subtherapeutic doses of the same beta-adrenergic blocking agents, he once again experienced excessive sleepiness. By discontinuing beta-blocking agents and introducing captopril, he felt much better, became pleasant and talkative, and blood pressure was well controlled. Beta antagonists are important drugs in the management of many cardiovascular problems. Propranolol, a lipophilic beta-blocking agent, and atenolol, a hydrophilic beta-blocking agent, are two of the major agents currently used clinically in the United States. Numerous neuropsychiatric side-effects of the beta-adrenergic blocking drugs have been reported, but hypersomnolence is not readily recognized as one of them. PMID:3665616

  13. Beta blockers: A new role in chemotherapy

    OpenAIRE

    Nagaraja, Archana S; Sadaoui, Nouara C.; Lutgendorf, Susan K.; Ramondetta, Lois M.; Sood, Anil K

    2013-01-01

    Beta-blockers are a class of drugs widely used to treat cardiac, respiratory and other ailments. They act by blocking beta-adrenergic receptor–mediated signalling. Studies in various cancers have shown that patients taking a beta-blocker have higher survival and lower recurrence and metastasis rates. This is supported by several preclinical and in vitro studies showing that adrenergic activation modulates apoptosis, promotes angiogenesis and other cancer hallmarks, and these effects can be ab...

  14. The pancreatic beta cell surface proteome

    OpenAIRE

    Stützer, I.; Esterházy, D.; Stoffel, M.

    2012-01-01

    The pancreatic beta cell is responsible for maintaining normoglycaemia by secreting an appropriate amount of insulin according to blood glucose levels. The accurate sensing of the beta cell extracellular environment is therefore crucial to this endocrine function and is transmitted via its cell surface proteome. Various surface proteins that mediate or affect beta cell endocrine function have been identified, including growth factor and cytokine receptors, transporters, ion channels and prote...

  15. Constructions for a bivariate beta distribution

    OpenAIRE

    Olkin, Ingram; Trikalinos, Thomas A.

    2014-01-01

    The beta distribution is a basic distribution serving several purposes. It is used to model data, and also, as a more flexible version of the uniform distribution, it serves as a prior distribution for a binomial probability. The bivariate beta distribution plays a similar role for two probabilities that have a bivariate binomial distribution. We provide a new multivariate distribution with beta marginal distributions, positive probability over the unit square, and correlations over the full ...

  16. Vibrationally coherent crossing and coupling of electronic states during internal conversion in beta-carotene

    OpenAIRE

    Liebel, Matz; Schnedermann, Christoph; Kukura, Philipp

    2013-01-01

    Coupling of nuclear and electronic degrees of freedom mediates energy flow in molecules after optical excitation. The associated coherent dynamics in polyatomic systems, however, remain experimentally unexplored. Here, we combined transient absorption spectroscopy with electronic population control to reveal nuclear wavepacket dynamics during the S2-S1 internal conversion in beta-carotene. We show that passage through a conical intersection is vibrationally coherent and thereby provides direc...

  17. Chromopeptides from C-phycocyanin. Structure and linkage of a phycocyanobilin bound to the. beta. subunit

    Energy Technology Data Exchange (ETDEWEB)

    Lagarias, J.C.; Glazer, A.N.; Rapoport, H.

    1979-08-15

    The smallest cyanogen bromide fragment derived from the ..beta.. subunit of Synechococcus sp. 6301 C-phycocyanin, the blue heptapeptide 2, has been investigated by 360-MHz /sup 1/H NMR spectroscopy. The peptide portion, heptapeptide 3, was synthesized independently and used in comparative spectroscopic analysis. These studies have led to complete assignment of the structure of the peptide-linked phycocyanobilin and elucidation of the nature of the thioether chromophore-peptide linkage.

  18. Double-loaded liposomes encapsulating Quercetin and Quercetin beta-cyclodextrin complexes: Preparation, characterization and evaluation

    Directory of Open Access Journals (Sweden)

    Jessy Shaji

    2012-01-01

    Full Text Available Beta-cyclodextrin (CD inclusion complexes of Quercetin were formed and characterized by Differential scanning calorimetry (DSC and Fourier transform infra-red spectroscopy (FTIR spectroscopy. Plain Quercetin liposomes using phosphatidylcholine and cholesterol were prepared and optimized. Factors such as ratio of lipids employed, drug:lipid ratio, etc. were fine tuned and optimized to achieve maximum entrapment of the Quercetin into the bilayer. Entrapment was further enhanced by double loading the liposomes. These were prepared by incorporating Quercetin as a plain drug as well as the inclusion complexes within the lipid bilayer and the aqueous compartment, respectively, of the liposomes using the thin film hydration technique. The highest entrapment was achieved with a lipid ratio of 9:1, and the amount of plain drug entering the bilayer was 1/10 th the amount of lipid employed. Double loading increased this value to one part of drug per five parts of lipid when Quercetin-beta-CD (1:1 mol/mol was entrapped. The release of Quercetin from liposomes was highest when the drug was entrapped in the form of a complex with beta cylodextrin. The high entrapment ability of Quercetin in the form of plain drug as well as beta cylodextrin-Quercetin complexes in comparison with plain drug is an indubitable advantage of this approach.

  19. Milk Intolerance, Beta-Casein and Lactose

    OpenAIRE

    Sebely Pal; Keith Woodford; Sonja Kukuljan; Suleen Ho

    2015-01-01

    True lactose intolerance (symptoms stemming from lactose malabsorption) is less common than is widely perceived, and should be viewed as just one potential cause of cows’ milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows’ milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-...

  20. Milk Intolerance, Beta-Casein and Lactose

    Directory of Open Access Journals (Sweden)

    Sebely Pal

    2015-08-01

    Full Text Available True lactose intolerance (symptoms stemming from lactose malabsorption is less common than is widely perceived, and should be viewed as just one potential cause of cows’ milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows’ milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows’ milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed.

  1. Stoichiometrically different inclusion complexes of 2-aminofluorene and 2-amino-9-hydroxyfluorene in beta-cyclodextrin: a spectrofluorimetric study.

    Science.gov (United States)

    Enoch, I V Muthu Vijayan; Swaminathan, M

    2006-09-01

    Beta-cyclodextrin (beta-CDx) forms inclusion complexes with 2-aminofluorene (2AF) and 2-amino-9-hydroxyfluorene (2AHF) in different stoichiometries (Guest-host ratio 1:1 and 1:2 respectively) which is discussed on the basis of study by absorption and fluorescence spectroscopy. The ground and the excited state acidity constants for the neutral-monocation equilibrium of the two fluorophores in aqueous beta-CDx medium are determined by spectrophotometric and fluorimetric titration methods respectively. The dual fluorescence observed for 2AHF monocation in aqueous solution is due to the formation of monocation-water exciplex. This monocation-water exciplex formation is hindered in beta-CDx solution by the inclusion complexation. Based on the results obtained, the structures of the inclusion complexes are proposed.

  2. Synthesis of {beta}-MoO{sup 3} by vacuum drying and its structural and electrochemical characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Juarez Ramirez, I.; Martinez-de la Cruz, A. [Centro de Investigacion y Desarrollo de Materiales Ceramicos (CIDEMAC), Facultad de Ciencias Quimicas, Universidad Autonoma de Nuevo Leon, Apartado Postal 1864, Monterrey, N.L. (Mexico)

    2003-01-01

    The {beta}-MoO{sub 3} was obtained successfully free of {alpha}-MoO{sub 3} through soft chemistry methods. The formation of {beta}-MoO{sub 3} with high purity was determined by the formation of the precursor MoO{sub 3}{center_dot}2H{sub 2}O when a solution of Na{sub 2}MoO{sub 4}{center_dot}2H{sub 2}O was passed through a cation-exchange resin. A structural, spectroscopic and thermal study of the polymorph synthesised was made by XRD, electron dispersion spectroscopy (EDS), FTIR and TGA/DTA techniques, respectively, in order to make a study about the possibilities of {beta}-MoO{sub 3} as active material in a lithium battery. Electrochemical experiments showed a high ability of the {beta}-MoO{sub 3} to form lithium molybdenum bronzes via a lithium insertion reaction.

  3. Review of double beta experiments

    CERN Document Server

    Sarazin, Xavier

    2012-01-01

    This paper is the first part of the manuscript written in April 2012 for my academic Accreditation to supervise research. It offers a review of the double beta experimental techniques. My purpose is to detail, for each technique, the different origins of background, how they can be identified, and how they can be reduced. Advantages and limitations are discussed. This review is organized as follows. First, the question of the possible Majorana nature for the neutrino is presented and the physic of neutrinoless double beta decay is summarized. Then I begin by presenting the tracko-calo NEMO-3 and SuperNEMO experiments. I've worked on these two experiments since 15 years. So it was natural to start with them with a relatively more exhaustive description. I will then present the germanium technique. I will then review the bolometer technique. I will describe in detail the recent progress in scintillating bolometers because I think that it is one of the most promising techniques. Finally I will review the large l...

  4. Beta attenuation transmission system (BATS)

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, R.C.; Fullbright, H.J.

    1977-01-01

    The beta attenuation transmission system (BATS) is an automated radiation gauge designed for quantitative measurement of component thickness in explosive detonators. The BATS was designed and built by Group M-1, the Nondestructive Testing Group, of the Los Alamos Scientific Laboratory to measure the areal thickness, in mg/cm/sup 2/, of a cylinder of high explosive (HE) enclosed within a plastic holder. The problem is to determine the density of the HE. A /sup 90/Sr source is collimated by a 0.25 x 1.59-mm slit, and the transmitted beta-particle flux is detected by a plastic scintillator, coupled to a photomultiplier tube. The detonator is transported through the radiation beam by a leadscrew, ballnut, stepping-motor combination. Continuous analog position data are available, derived from the output from a linear-actuated potentiometer attached to the scanner. A linear electrometer amplifies the detected signal, which is then integrated for a preselected time, to obtain the desired statistical accuracy. A microprocessor (..mu..P) is used to control the scanner position and to make the data readings at the assigned positions. The data are stored, and, at the completion of the scan, are processed into the desired format. The final answer is displayed to the operator or output to a peripheral device for permanent record. The characteristics of the radiation source, the collimator, the signal detection and conditioning, and the final results are described in detail. The scanner and the microprocessor control system are briefly outlined.

  5. Challenges in Double Beta Decay

    Directory of Open Access Journals (Sweden)

    Oliviero Cremonesi

    2014-01-01

    Full Text Available In the past ten years, neutrino oscillation experiments have provided the incontrovertible evidence that neutrinos mix and have finite masses. These results represent the strongest demonstration that the electroweak Standard Model is incomplete and that new Physics beyond it must exist. In this scenario, a unique role is played by the Neutrinoless Double Beta Decay searches which can probe lepton number conservation and investigate the Dirac/Majorana nature of the neutrinos and their absolute mass scale (hierarchy problem with unprecedented sensitivity. Today Neutrinoless Double Beta Decay faces a new era where large-scale experiments with a sensitivity approaching the so-called degenerate-hierarchy region are nearly ready to start and where the challenge for the next future is the construction of detectors characterized by a tonne-scale size and an incredibly low background. A number of new proposed projects took up this challenge. These are based either on large expansions of the present experiments or on new ideas to improve the technical performance and/or reduce the background contributions. In this paper, a review of the most relevant ongoing experiments is given. The most relevant parameters contributing to the experimental sensitivity are discussed and a critical comparison of the future projects is proposed.

  6. Association of heterocellular HPFH, beta(+)-thalassaemia, and delta beta(0)-thalassaemia: haematological and molecular aspects.

    OpenAIRE

    Cianetti, L; Care, A; Sposi, N M; Giampaolo, A; Calandrini, M; Petrini, M.; Massa, A.; Marinucci, M.; Mavilio, F; Ceccanti, M.

    1984-01-01

    An Italian family in which heterocellular hereditary persistence of fetal haemoglobin (HPFH) interacts with both beta(+)- and delta beta-thalassaemia is described. The index case was an 8 year old girl who was presumed to inherit both heterocellular HPFH and beta (+)-thalassaemia from her mother and delta beta-thalassaemia from her father. She was healthy and never needed blood transfusions. The possible contribution of heterocellular HPFH to the less severe expression of the compound delta b...

  7. Metallomic EPR spectroscopy.

    Science.gov (United States)

    Hagen, Wilfred R

    2009-09-01

    Based on explicit definitions of biomolecular EPR spectroscopy and of the metallome, this tutorial review positions EPR in the field of metallomics as a unique method to study native, integrated systems of metallobiomolecular coordination complexes subject to external stimuli. The specific techniques of whole-system bioEPR spectroscopy are described and their historic, recent, and anticipated applications are discussed.

  8. Heterodyned holographic spectroscopy

    NARCIS (Netherlands)

    Douglas, NG

    1997-01-01

    In holographic spectroscopy an image of an interference pattern is projected onto a detector and transformed back to the input spectrum. The general characteristics are similar to those of Fourier transform spectroscopy, but the spectrum is obtained without scanning. In the heterodyned arrangement o

  9. Coherent detection spectroscopy

    NARCIS (Netherlands)

    Bueren, H.G. van

    1969-01-01

    Various methods of optical spectroscopy are compared, with special emphasis on resolution and acceptance of the systems. It is shown that coherent detection with a laser as a local oscillator has important advantages for specific applications in astronomical spectroscopy and interferometry, especial

  10. The impact of beta-elemene on beta-tubulin of human hepatoma hepg2 cells

    Institute of Scientific and Technical Information of China (English)

    Yuqiu Mao; Liying Ban; Jielin Zhang; Li Hou; Xiaonan Cui

    2014-01-01

    Objective:The aim of this study was to investigate the impact of beta-elemene injection on the growth and beta-tubulin of human hepatocarcinoma HepG2 cells. Methods:cellproliferation was assessed by MTT assay. cellcycle distribution was detected by flow cytometry (FCM). The mRNA expression of beta-tubulin was measured by RT-PCR. West-ern blot analysis was used to determine protein expression of beta-tubulin and the polymerization of beta-tubulin. Results:Beta-elemene injection inhibited HepG2 cells proliferation in a dose-and time-dependent manner;FCM analysis indicated beta-elemene injection induced cellcycle arrested at S phase. RT-PCR and western-blot analysis showed that beta-elemene injection down-regulated beta-tubulin expression at both mRNA and protein levels, presenting a dose-dependent manner. Moreover, beta-elemene injection reduced the polymerization of microtubules in a dose-dependent manner. Conclusion:Beta-elemene injection can inhibit the proliferation of hepatoma HepG2 cells, the mechanism might be partly related to the down-regulation of beta-tubulin and inhibition of microtubular polymerization.

  11. Expressions of GSK-3beta, Beta-Catenin and PPAR-Gamma in Medulloblastoma

    Institute of Scientific and Technical Information of China (English)

    Xiong Zhang; Lu Si; Yu Li; Can Mi

    2009-01-01

    Objective: To investigate the expressions of GSK-3beta, Beta-catenin and PPAR-gamma, and their relationship in medulloblastoma, and to explore their value in clinic application.Methods: Immunohistochemical staining with SP method was conducted to determine the expressions of GSK-3beta, Beta-catenin and PPAR-gamma in 48 cases of medulloblastoma and 10 normal cerebellar tissues.Results: The rate of abnormal expressions of beta-catenin and PPAR-gamma in MB was higher than that in normal. Conversely, GSK-3beta in MB was lower than that in the normal (P<0.05). Furthermore, in medulloblastoma, beta-catenin and GSK-3beta showed a negative correlation, PPAR-gamma and beta-catenin had a positive correlation.Conclusion: Abnormal expression of beta-catenin plays a crucial role in the development of medulloblastoma. Meanwhile, PPAR-gamma and GSK-3beta which are tightly related with beta-catenin are both involved in the genesis and development of medulloblastoma.

  12. The pharmacokinetics of beta-cyclodextrin and hydroxypropyl-beta-cyclodextrin in the rat

    NARCIS (Netherlands)

    Frijlink, H W; Visser, J; Hefting, N R; Oosting, R; Meijer, D K; Lerk, C F

    1990-01-01

    Hydroxypropyl-beta-cyclodextrin was analyzed by HPLC using postcolumn complexation with phenolphthalein and negative colorimetric detection, with a detection limit of 20 micrograms/ml. The pharmacokinetics of beta-cyclodextrin and of hydroxypropyl-beta-cyclodextrin were studied after intravenous adm

  13. Imperfect World of beta beta-decay Nuclear Data Sets

    Energy Technology Data Exchange (ETDEWEB)

    Pritychenko, B. [Brookhaven National Lab. (BNL), Upton, NY (United States). NNDC

    2015-01-03

    The precision of double-beta ββ-decay experimental half lives and their uncertainties is reanalyzed. The method of Benford's distributions has been applied to nuclear reaction, structure and decay data sets. First-digit distribution trend for ββ-decay T2v1/2 is consistent with large nuclear reaction and structure data sets and provides validation of experimental half-lives. A complementary analysis of the decay uncertainties indicates deficiencies due to small size of statistical samples, and incomplete collection of experimental information. Further experimental and theoretical efforts would lead toward more precise values of-decay half-lives and nuclear matrix elements.

  14. Beta-glucosidase I variants with improved properties

    Energy Technology Data Exchange (ETDEWEB)

    Bott, Richard R.; Kaper, Thijs; Kelemen, Bradley; Goedegebuur, Frits; Hommes, Ronaldus Wilhelmus; Kralj, Slavko; Kruithof, Paulien; Nikolaev, Igor; Van Der Kley, Wilhelmus Antonious Hendricus; Van Lieshout, Johannes Franciscus Thomas; Van Stigt Thans, Sander

    2016-09-20

    The present disclosure is generally directed to enzymes and in particular beta-glucosidase variants. Also described are nucleic acids encoding beta-glucosidase variants, compositions comprising beta-glucosidase variants, methods of using beta-glucosidase variants, and methods of identifying additional useful beta-glucosidase variants.

  15. Fourier transform Raman spectroscopy of the four crystallographic phases of {alpha}, {beta}, {gamma} and {epsilon} 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.0{sup 5,9}.0{sup 3,11}]dodecane (HNIW, CL-20)

    Energy Technology Data Exchange (ETDEWEB)

    Goede, Patrick; Latypov, Nikolaj V.; Oestmark, Henric [Department of Energetic Materials, Grindsjoen Research Center, Swedish Defence Research Agency, FOI, SE-147 25 Tumba (Sweden)

    2004-08-01

    Fourier transform Raman Spectroscopy (Nd: YAG laser at 1064 nm) was used to characterize the four stable phases of 2,4,6,8,10,12-Hexanitro-2,4,6,8,10,12-hexaazatetracyclo[5.5.0.0{sup 5,9}.0{sup 3,11}]dodecane (HNIW, CL-20). Raman spectra are reported over the region from 0-4000 cm{sup -1}{sub ,} relative to the laser line. A tentative assignment of the most predominant Raman peaks was made with the aid of QM calculations at the B3LYP/6-31G(d) level. A method for detecting polymorphic impurities in {epsilon}-CL-20 was also developed. The detection level for polymorphic impurities was determined to be below 2%. A method for producing {gamma}-CL-20 is also presented. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  16. Dosimetry of low-energy beta radiation

    Energy Technology Data Exchange (ETDEWEB)

    Borg, J.

    1996-08-01

    Useful techniques and procedures for determination of absorbed doses from exposure in a low-energy {beta} radiation field were studied and evaluated in this project. The four different techniques included were {beta} spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical low-energy {beta} radiation field a moderated spectrum from a {sup 14}C source (E{sub {beta}},{sub max} =156 keV) was chosen for the study. The measured response of a Si(Li) detector to photons (bremsstrahlung) showed fine agreement with the MC calculated photon response, whereas the difference between measured and MC calculated responses to electrons indicates an additional dead layer thickness of about 12 {mu}m in the Si(Li) detector. The depth-dose profiles measured with extrapolation chambers at two laboratories agreed very well, and it was confirmed that the fitting procedure previously reported for {sup 147}Pm depth-dose profiles is also suitable for {beta} radiation from {sup 14}C. An increasing difference between measured and MC calculated dose rates for increasing absorber thickness was found, which is explained by limitations of the EGS4 code for transport of very low-energy electrons (below 10-20 keV). Finally a study of the thermally stimulated exoelectron emission (TSEE) response of BeO thin film dosemeters to {beta} radiation for radiation fields with maximum {beta} energies ranging from 67 keV to 2.27 MeV is reported. For maximum {beta} energies below approximately 500 keV, a decrease in the response amounting to about 20% was observed. It is thus concluded that a {beta} dose higher than about 10 {mu}Gy can be measured with these dosemeters to within 0 to -20% independently of the {beta}energy for E{sub {beta}},{sub max} values down to 67 keV. (au) 12 tabs., 38 ills., 71 refs.

  17. [2,4-13 C2 ]-beta-Hydroxybutyrate metabolism in human brain.

    Science.gov (United States)

    Pan, Jullie W; de Graaf, Robin A; Petersen, Kitt F; Shulman, Gerald I; Hetherington, Hoby P; Rothman, Douglas L

    2002-07-01

    Infusions of [2,4-13C2]-beta-hydroxybutyrate and 1H-13C polarization transfer spectroscopy were used in normal human subjects to detect the entry and metabolism of beta-hydroxybutyrate in the brain. During the 2-hour infusion study, 13C label was detectable in the beta-hydroxybutyrate resonance positions and in the amino acid pools of glutamate, glutamine, and aspartate. With a plasma concentration of 2.25 +/- 0.24 mmol/L (four volunteers), the apparent tissue beta-hydroxybutyrate concentration reached 0.18 +/- 0.06 mmol/L during the last 20 minutes of the study. The relative fractional enrichment of 13C-4-glutamate labeling was 6.78 +/- 1.71%, whereas 13C-4-glutamine was 5.68 +/- 1.84%. Steady-state modeling of the 13C label distribution in glutamate and glutamine suggests that, under these conditions, the consumption of the beta-hydroxybutyrate is predominantly neuronal, used at a rate of 0.032 +/- 0.009 mmol. kg-1. min-1, and accounts for 6.4 +/- 1.6% of total acetyl coenzyme A oxidation. These results are consistent with minimal accumulation of cerebral ketones with rapid utilization, implying blood-brain barrier control of ketone oxidation in the nonfasted adult human brain. PMID:12142574

  18. Search for beta sup - and beta sup -beta sup - decays of sup 4 sup 8 Ca

    CERN Document Server

    Bakalyarov, A; Barabash, A; Briançon, C; Brudanin, V; Egorov, V; Hubert, F; Hubert, P; Kovalik, A; Lebedev, V I; Rukhadze, N I; Stekl, I; Umatov, V; Vylov, T D

    2002-01-01

    A sup 4 sup 8 CaCO sub 3 powder sample containing 20.18 g of sup 4 sup 8 Ca was measured for 797 h with a 400 cm sup 3 low-background HPGe detector. New limits on decays of sup 4 sup 8 Ca were obtained. For single beta transitions to sup 4 sup 8 Sc the limits are equal to 0.71x10 sup 2 sup 0 y, 1.1x10 sup 2 sup 0 y, and 0.82x10 sup 2 sup 0 y for transitions to the ground state, excited 5 sup + and 4 sup + states, respectively. The new limits on double beta decay to excited states of sup 4 sup 8 Ti are equal to 0.47x10 sup 2 sup 0 y, 1.1x10 sup 2 sup 0 y, and 0.90x10 sup 2 sup 0 y for transitions to the first 2 sup + , second 2 sup + and first 0 sup + excited states, respectively. All limits are given at the 90% CL.

  19. [Hemoglobin C -- beta-thalassemia disease and homozygous beta-thalassemia in a black African family (author's transl)].

    Science.gov (United States)

    Basset, P; Fall, M; Oudart, J L

    1975-01-01

    The study of a Malian family has allowed to prove existence of two types of beta-thalassemia genes: the beta0 gene which suppresses the synthesis of the beta chain into cis position and the beta+ gene which slows down only partially this synthesis. The difference between this two genes has been possible owing to the hemoglobin C found in this family and induced by the betaC mutated gene. The segregation of the four genes betaA, betaC, beta0 thal, and beta+ thal. has allowed to compare all the possible phenotypes deriving from the combinations by two of these allelic genes. PMID:128735

  20. Inclusion complex of butachlor with beta-cyclodextrin: characterization, solubility, and speciation-dependent adsorption.

    Science.gov (United States)

    Bian, Haitao; Chen, Jingwen; Cai, Xiyun; Liu, Ping; Liu, Huihui; Qiao, Xianliang; Huang, Liping

    2009-08-26

    Due to soil adsorption, higher amounts of the herbicide butachlor are necessary to achieve its herbicidal activity, hence increasing its environmental risks. In this study, the effects of beta-cyclodextrin (beta-CD) on solubility and soil adsorption of butachlor were investigated. Formation of a 1:1 stoichiometric inclusion complex between them with an apparent stability constant of 443 L mol(-1) was confirmed in the solution. Fourier transform infrared spectroscopy showed that the (N-CO) amide bond and alkyl ether moiety of butachlor molecule could enter into the cavity of beta-CD, but the double-substituted aromatic ring was excluded because it was larger size than the cavity. Significant enhancing dissolution of butachlor in the inclusion complex occurred in comparison to the free herbicide. The adsorption of butachlor on soil was reduced with an increase of beta-CD concentration because of the formation of the inclusion complex with low adsorption potency. Although the sorption distribution coefficient of complexed butachlor (i.e., butachlor/beta-cyclodextrin inclusion complex) (K(d,c) = 6.14) was about 14% of that of the free herbicide (K(d,f) = 44.54), the proportion of the adsorbed amount of complexed butachlor to the total adsorbed amount rose with the increase of beta-CD concentration. Thus, the adsorption of inclusion complex cannot be neglected in the presence of high concentrations cyclodextrins, although its water solubility was much higher than that of the free herbicide. These results indicate that beta-CD may be used as a formation additive to improve the solubility of butachlor, reduce its adsorption on soil, and increase the availability of butachlor for weeds.

  1. Infrared and Raman characterization of beta iron silicide

    Science.gov (United States)

    Lefki, K.; Muret, P.; Bustarret, E.; Boutarek, N.; Madar, R.; Chevrier, J.; Derrien, J.; Brunel, M.

    1991-12-01

    Samples of beta-iron silicide were prepared by three different methods : solid phase reaction on silicon (111), on a monocrystaline FeSi substrate, and from the melt. These samples have been characterized by x-ray diffraction and investigated by Infrared and Raman spectroscopies. The infrared and Raman lines are compared with theoretical predictions given by the factor group analysis of the silicide primitive cell, which yields the number and the symmetry of the different modes. We relate the red shift of the Infrared and Raman lines on samples with smaller lattice parameters to the presence of Iron vacancies in films deposited on silicon, in agreement with the sign of the thermoelectric power.

  2. Broad resonances and beta-decay

    DEFF Research Database (Denmark)

    Riisager, K.; Fynbo, H. O. U.; Hyldegaard, S.;

    2015-01-01

    Beta-decay into broad resonances gives a distorted lineshape in the observed energy spectrum. Part of the distortion arises from the phase space factor, but we show that the beta-decay matrix element may also contribute. Based on a schematic model for p-wave continuum neutron states it is argued...

  3. A proportional-scintillation counter beta spectrometer

    International Nuclear Information System (INIS)

    Using a proportional counter for coincidence gating of events in a plastic scintillator provides selective registration of beta interactions in the scintillator. This technique has been used to construct a field instrument that can selectively collect beta spectra (coincidence gating) or gamma spectra (anticoincidence gating). Associated dose rates are calculated from the spectra

  4. Localization of thymosin beta-4 in tumors

    DEFF Research Database (Denmark)

    Larsson, L. -I.; Holck, Susanne

    2007-01-01

    Overexpression of thymosin beta-4 has been linked to malignant progression but the localization of this polypeptide within tumors is incompletely known. We therefore examined breast cancers for thymosin beta-4 using immunofluorescence. Reactive cells were identified with monoclonal cell marker...... in the tumor microenvironment may modulate tumor behavior....

  5. Higher-Order Beta Matching with Solutions in Long Beta-Eta Normal Form

    DEFF Research Database (Denmark)

    Støvring, Kristian

    2006-01-01

    Higher-order matching is a special case of unification of simply-typed lambda-terms: in a matching equation, one of the two sides contains no unification variables. Loader has recently shown that higher-order matching up to beta equivalence is undecidable, but decidability of higher-order matching...... up to beta-eta equivalence is a long-standing open problem.We show that higher-order matching up to beta-eta equivalence is decidable if and only if a restricted form of higher-order matching up to beta equivalence is decidable: the restriction is that solutions must be in long beta-eta normal form....

  6. Adaptive changes in pancreatic beta cell fractional area and beta cell turnover in human pregnancy

    OpenAIRE

    Butler, A. E.; Cao-Minh, L.; Galasso, R; Rizza, R. A.; Corradin, A.; Cobelli, C; Butler, P C

    2010-01-01

    Aims/hypothesis We sought to establish the extent and basis for adaptive changes in beta cell numbers in human pregnancy. Methods Pancreas was obtained at autopsy from women who had died while pregnant (n = 18), post-partum (n = 6) or were not pregnant at or shortly before death (controls; n = 20). Pancreases were evaluated for fractional pancreatic beta cell area, islet size and islet fraction of beta cells, beta cell replication (Ki67) and apoptosis (TUNEL), and indirect markers of beta cel...

  7. Identification of a novel angiotensin-I-converting enzyme inhibitory peptide corresponding to a tryptic fragment of bovine beta-lactoglobulin.

    Science.gov (United States)

    Mullally, M M; Meisel, H; FitzGerald, R J

    1997-02-01

    The angiotensin-I-converting enzyme (ACE) inhibitory activity of a tryptic digest of bovine beta-lactoglobulin (beta-lg) was investigated. Intact beta-lg essentially did not inhibit ACE while the tryptic digest gave an 84.3% inhibition of ACE. Peptide material eluting between 20 and 25% acetonitrile during C18 solid-phase extraction of the beta-lg tryptic digest inhibited ACE by 93.6%. This solid-phase extraction fraction was shown by mass spectroscopy to contain beta-lg f(142-148). This peptide had an ACE IC50 value of 42.6 micromol/l. The peptide was resistant to further digestion with pepsin and was hydrolysed to a very low extent with chymotrypsin. The contribution of specific amino acid residues within the peptide to ACE inhibitory activity and the potential application of this peptide as a nutraceutical is discussed.

  8. Beta-conjugates of real algebraic numbers as Puiseux expansions

    CERN Document Server

    Verger-Gaugry, Jean-Louis

    2011-01-01

    The beta-conjugates of a base of numeration $\\beta > 1$, $\\beta$ being a Parry number, were introduced by Boyd, in the context of the R\\'enyi-Parry dynamics of numeration system and the beta-transformation. These beta-conjugates are canonically associated with $\\beta$. Let $\\beta > 1$ be a real algebraic number. A more general definition of the beta-conjugates of $\\beta$ is introduced in terms of the Parry Upper function $f_{\\beta}(z)$ of the beta-transformation. We introduce the concept of a germ of curve at $(0,1/\\beta) \\in \\mathbb{C}^{2}$ associated with $f_{\\beta}(z)$ and the reciprocal of the minimal polynomial of $\\beta$. This germ is decomposed into irreducible elements according to the theory of Puiseux, gathered into conjugacy classes. The beta-conjugates of $\\beta$, in terms of the Puiseux expansions, are given a new equivalent definition in this new context. If $\\beta$ is a Parry number the (Artin-Mazur) dynamical zeta function $\\zeta_{\\beta}(z)$ of the beta-transformation, simply related to $f_{\\b...

  9. Ranking Beta Sheet Topologies of Proteins

    DEFF Research Database (Denmark)

    Fonseca, Rasmus; Helles, Glennie; Winter, Pawel

    2010-01-01

    One of the challenges of protein structure prediction is to identify long-range interactions between amino acids.  To reliably predict such interactions, we enumerate, score and rank all beta-topologies (partitions of beta-strands into sheets, orderings of strands within sheets and orientations...... of paired strands) of a given protein.  We show that the beta-topology corresponding to the native structure is, with high probability, among the top-ranked. Since full enumeration is very time-consuming, we also suggest a method to deal with proteins with many beta-strands. The results reported...... in this paper are highly relevant for ab initio protein structure prediction methods based on decoy generation. The top-ranked beta-topologies can be used to find initial conformations from which conformational searches can be started. They can also be used to filter decoys by removing those with poorly...

  10. Beta cell proliferation and growth factors

    DEFF Research Database (Denmark)

    Nielsen, Jens Høiriis; Svensson, C; Møldrup, Annette;

    1999-01-01

    Formation of new beta cells can take place by two pathways: replication of already differentiated beta cells or neogenesis from putative islet stem cells. Under physiological conditions both processes are most pronounced during the fetal and neonatal development of the pancreas. In adulthood little...... cloned a novel GH/PRL stimulated rat islet gene product, Pref-1 (preadipocyte factor-1). This protein contains six EGF-like motifs and may play a role both in embryonic pancreas differentiation and in beta cell growth and function. In summary, the increasing knowledge about the mechanisms involved...... increase in the beta cell number seems to occur. In pregnancy, however, a marked hyperplasia of the beta cells is observed both in rodents and man. Increased mitotic activity has been seen both in vivo and in vitro in islets exposed to placental lactogen (PL), prolactin (PRL) and growth hormone (GH...

  11. Peripheral beta-endorphin and pain modulation.

    Science.gov (United States)

    Hartwig, A C

    1991-01-01

    Beta-endorphin is a peptide with morphine-like effects produced primarily in the anterior lobe of the pituitary gland. After its cleavage from the parent molecule, proopiomelanocortin, beta-endorphin is circulated via the blood stream to interact with specific opioid receptors located throughout the body. The peptide produces analgesia by inhibiting the firing of peripheral somatosensory fibers. It also affects other senses, such as vision, hearing, and smell. Whereas the ability to increase beta-endorphin secretion during times of surgical stress is positively correlated with amelioration of pain, the administration of exogenous opioids, such as fentanyl, reduces plasma beta-endorphin. Decreased beta-endorphin concentrations may play a role in trigeminal neuralgia, migraine headache, and rheumatoid arthritis. PMID:1814247

  12. Biodegradable star polymers functionalized with beta-cyclodextrin inclusion complexes.

    Science.gov (United States)

    Setijadi, Eki; Tao, Lei; Liu, Jingquan; Jia, Zhongfan; Boyer, Cyrille; Davis, Thomas P

    2009-09-14

    Three-armed biodegradable star polymers made from polystyrene (polySt) and poly (polyethylene glycol) acrylate (polyPEG-A) were synthesized via a "core first" methodology using a trifunctional RAFT agent, created by attaching RAFT agents to a core via their R-groups. The resultant three-armed polymeric structures were well-defined, with polydispersity indices less than 1.2. Upon aminolysis and further reaction with dithiodipyridine (DTDP), these three-armed polymers could be tailored with sulfhydryl and pyridyldisulfide (PDS) end functionalities, available for further reaction with any free-sulfhydryl group containing precursors to form disulfide linkages. Nuclear magnetic resonance (NMR) confirmed that more than 98% of the polymer arms retained integral trithiocarbonate active sites after polymerization. Intradisulfide linkages between the core and the arms conferred biodegradability on the star architectures. Subsequently, the arm-termini were attached to cholesterol also via disulfide linkages. The cholesterol terminated arms were then used to form supramolecular structures via inclusion complex formation with beta-cyclodextrin (beta-CD). The star architectures were found to degrade rapidly on treatment with DL-dithiothereitol (DTT). The star polymers and supramolecular structures were characterized using gel permation chromatography (GPC), static light scattering (SLS), 2D NMR, and fluorescence spectroscopy.

  13. VLT imaging of the {\\beta} Pictoris gas disk

    CERN Document Server

    Nilsson, R; Olofsson, G; Fathi, K; Thébault, Ph; Liseau, R

    2012-01-01

    Circumstellar debris disks older than a few Myr should be largely devoid of primordial gas remaining from the protoplanetary disk phase. Tracing the origin of observed atomic gas in Keplerian rotation in the edge-on debris disk surrounding the ~12 Myr old star {\\beta} Pictoris requires more detailed information about its spatial distribution than has previously been acquired by limited slit spectroscopy. Especially indications of asymmetries and presence of Ca II gas at high disk latitudes call for additional investigation. We set out to recover a complete image of the Fe I and Ca II gas emission around {\\beta} Pic by spatially resolved, high-resolution spectroscopic observations to better understand the morphology and origin of the gaseous disk component. The multiple fiber facility FLAMES/GIRAFFE at the VLT, with the large IFU ARGUS, was used to obtain spatially resolved optical spectra in four regions covering the northeast and southwest side of the disk. Emission lines from Fe I and Ca II were mapped and ...

  14. Cavity-enhanced spectroscopies

    CERN Document Server

    van Zee, Roger

    2003-01-01

    ""Cavity-Enhanced Spectroscopy"" discusses the use of optical resonators and lasers to make sensitive spectroscopic measurements. This volume is written by the researcchers who pioneered these methods. The book reviews both the theory and practice behind these spectroscopic tools and discusses the scientific discoveries uncovered by these techniques. It begins with a chapter on the use of optical resonators for frequency stabilization of lasers, which is followed by in-depth chapters discussing cavity ring-down spectroscopy, frequency-modulated, cavity-enhanced spectroscopy, intracavity spectr

  15. Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

    DEFF Research Database (Denmark)

    Martens, Geert A; Jiang, Lei; Hellemans, Karine H;

    2011-01-01

    The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...... microdissected beta cells, monitor adaptations of the beta cell phenotype to fasting, and retrieve possible conserved transcriptional regulators....

  16. Complement activation by the amyloid proteins A beta peptide and beta 2-microglobulin

    DEFF Research Database (Denmark)

    Nybo, Mads; Nielsen, E H; Svehag, S E

    1999-01-01

    Complement activation (CA) has been reported to play a role in the pathogenesis of Alzheimer's disease (AD). To investigate whether CA may contribute to amyloidogenesis in general, the CA potential of different amyloid fibril proteins was tested. CA induced by A beta preparations containing soluble...... protein, protofilaments and some fibrils or only fibrils in a solid phase system (ELISA) was modest with a slow kinetics compared to the positive delta IgG control. Soluble A beta induced no detectable CA in a liquid phase system (complement consumption assay) while fibrillar A beta caused CA at 200 mg....../ml and higher concentrations. Soluble beta 2-microglobulin (beta 2M) purified from peritoneal dialysates was found to be as potent a complement activator as A beta in both solid and liquid phase systems while beta 2M purified from urine exhibited lower activity, a difference which may be explained...

  17. Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

    DEFF Research Database (Denmark)

    Martens, Geert A; Jiang, Lei; Hellemans, Karine H;

    2011-01-01

    of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser......The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... capture microdissected beta cells, monitor adaptations of the beta cell phenotype to fasting, and retrieve possible conserved transcriptional regulators....

  18. Experimental and theoretical studies on the inclusion complexation of syringic acid with alpha-, beta-, gamma- and heptakis(2,6-di-O-methyl)-beta-cyclodextrin.

    Science.gov (United States)

    Song, Le Xin; Wang, Hai Ming; Xu, Peng; Yang, Yan; Zhang, Zi Qiang

    2008-04-01

    Intermolecular interactions of alpha-, beta-, gamma- and heptakis(2,6-di-O-methyl)-beta-cyclodextrin (CD) with syringic acid (Syr) in aqueous solution are investigated by fluorescence spectroscopy. The fluorescence intensity of Syr gradually increases with the addition of the CDs. The formation constants (K) of the host-guest inclusion complexes are determined using a nonlinear analysis. The association abilities of Syr with the CDs decrease in the order gamma->beta->alpha- approximately DMbeta-CD. Both the intrinsic binding abilities of the CDs and the structural effect of Syr are taken into consideration when comparing the K values. Based on the results of NMR experimental and theoretical PM3 calculations both in vacuo and in water, it is found that Syr stays near the wider rim of alpha-CD cavity. Both the number of substituted groups (NSG) in a guest and the molar volume ratio of the guest to host cavity (MVR) play an important role in forming the CD supramolecular complexes of a homologous series of phenol derivatives, such as 2-methoxylphenol (2-Mop), eugenol (Eug) and Syr, i.e., an appropriate NSG or MVR in an inclusion system, such as in 2-Mop-alpha-CD, Eug-beta-CD and Syr-gamma-CD systems, can maximize the intermolecular interaction between host and guest.

  19. Modulation gamma resonance spectroscopy

    International Nuclear Information System (INIS)

    Possibility to control dynamic processes in a matter through gamma-resonance modulation by high-frequency external variable fields in excess of inverse lifetimes of the Moessbauer nuclei excited states, that is, within the megahertz frequency range lies in the heart of the modulation gamma-resonance spectroscopy. Through the use of the gamma-resonance process theoretical analysis methods and of the equation solution method for the density matrix with the secondary quantization of gamma-radiation field one attacks the problems dealing with the effect of both variable fields and relaxation on gamma-resonance. One has studied the gamma-radiation ultrasound modulation stages. One points out a peculiar role of the gamma-magnetic resonance effect in modulation gamma resonance spectroscopy formation. One forecasts development of the modulation gamma-resonance spectroscopy into the nonlinear gamma-resonance spectroscopy

  20. Advances in DUV spectroscopy

    DEFF Research Database (Denmark)

    Buchhave, Preben; Tidemand-Lichtenberg, Peter; Mogensen, Claus Tilsted

    The would-be advantages of deep UV (DUV) spectroscopy are well known, but the potential applications have so far not been fully realized due to technological limitations and, perhaps, lack of bright ideas. However, new components and new knowledge about DUV spectra and spectroscopic methods...... combined with increasing needs for solutions to practical problems in environmental protection, medicine and pollution monitoring promise a new era in DUV spectroscopy. Here we shall review the basis for DUV spectroscopy, both DUV fluorescence and DUV Raman spectroscopy, and describe recent advances...... in technology and principles that could be applied to new and improved applications of this promising technique. As an example we describe a recent cooperation between Grundfos, DTU and Intarsia Optics to measure live bacterial cells in drinking water....

  1. Fluorescence correlation spectroscopy

    NARCIS (Netherlands)

    M.A. Hink

    2015-01-01

    Fluorescence fluctuation spectroscopy techniques allow the quantification of fluorescent molecules present at the nanomolar concentration level. After a brief introduction to the technique, this chapter presents a protocol including background information in order to measure and quantify the molecul

  2. Hadron Spectroscopy -- Theory

    CERN Document Server

    Swanson, E S

    2009-01-01

    A brief review of theoretical progress in hadron spectroscopy and nonperturbative QCD is presented. Attention is focussed on recent lattice gauge theory, the Dyson-Schwinger formalism, unquenching constituent models, and some beyond the Standard Model physics.

  3. Biquinolino-modified beta-cyclodextrin dimers and their metal complexes as efficient fluorescent sensors for the molecular recognition of steroids.

    Science.gov (United States)

    Liu, Yu; Song, Yun; Chen, Yong; Li, Xue-Qing; Ding, Fei; Zhong, Rui-Qin

    2004-08-01

    A series of bridged beta-cyclodextrin (beta-CyD) dimers possessing functional tethers of various lengths was synthesized in moderate yield by the treatment of 2,2'-biquinoline- 4,4'-dicarboxylic dichloride with beta-CyD or mono[6-oligo(ethylenediamino)-6-deoxy]-beta-CyDs. The products were 2,2'-biquinoline-4,4'-dicarboxy-bridged bis(6-O-beta-CyD) (8), N,N'-bis(2-aminoethyl)-2,2'-biquinoline-4,4'-dicarboxamide-bridged bis(6-amino-6-deoxy-beta-CyD) (9), and N,N'-bis(5-amino-3-azapentyl)-2,2'-biquinoline-4,4'-dicarboxamide-bridged bis(6-amino-6-deoxy-beta-CyD) (10). The reaction of 8-10 with copper perchlorate give their copper(II) complexes 11-13 in satisfactory yields of over 77 %. All the bis(beta-CyD)s 8-13 act as efficient fluorescent sensors and display remarkable fluorescence enhancement upon addition of optically inert steroids. The inclusion complexation behaviors of 8-13 when treated with the representative steroids cholate (14), deoxycholate (15), and glycocholate (16) in aqueous solution at 25 degrees C were investigated by means of UV/Vis spectroscopy, conductivity and fluorescence measurements, circular dichroism spectroscopy, and 2D NMR spectroscopy. The tether length of bis(beta-CyD) 9 allows it to adopt a cooperative host-tether-guest binding mode in which the spacer and guest are co-included in the two CyD cavities. As a result of this cooperation, 9 has a stability constant (K(s)) about 2x10(2) times higher than that of monomodified beta-CyD 4 for inclusion complexation with cholate. Metallooligo(beta-CyD)s with four beta-CyD units have enhanced binding abilities compared with monomodified beta-CyDs. These metallo compounds have binding affinities for guest steroids that are up to 50-4.1x10(3) times higher than those of CyDs 2-4. The guest-induced fluorescence enhancement of bis(CyD)s opens a new channel for the design of sensor materials. The complex stability constants of these compounds are discussed from the viewpoint of induced-fit interaction

  4. Resonance ionization spectroscopy 1986

    International Nuclear Information System (INIS)

    The paper presents the proceedings of the Third International Symposium on Resonance Ionization Spectroscopy and its Applications, held at the University College of Swansea, Wales, 1986. The Symposium is divided into eight main sections entitled: photophysics and spectroscopy, noble gas atom counting, resonance ionization mass spectrometry, materials and surface analysis, small molecules, medical and environmental applications, resonance ionization and materials separation, and elementary particles and nuclear physics. Thirty papers were chosen for INIS and indexed separately. (U.K.)

  5. Ultrafast infrared vibrational spectroscopy

    CERN Document Server

    Fayer, Michael D

    2013-01-01

    The past ten years or so have seen the introduction of multidimensional methods into infrared and optical spectroscopy. The technology of multidimensional spectroscopy is developing rapidly and its applications are spreading to biology and materials science. Edited by a recognized leader in the field and with contributions from top researchers, including experimentalists and theoreticians, this book presents the latest research methods and results and will serve as an excellent resource for other researchers.

  6. Investigating the Influence of Mesoporosity in Zeolite Beta on its Catalytic Performance for the Conversion of Methanol to Hydrocarbons

    KAUST Repository

    Liu, Zhaohui

    2015-08-26

    Hierarchically porous zeolite Beta (Beta-MS) synthesized by a soft-templating method contains remarkable intra-crystalline mesoporosity, which reduces the diffusion length in zeolite channels down to several nanometers and alters the distribution of Al among distinct crystallographic sites. When used as a catalyst for the conversion of methanol to hydrocarbons (MTH) at 330 oC, Beta-MS exhibited a 2.7-fold larger conversion capacity, a 2.0-fold faster reaction rate, and a remarkably longer lifetime than conventional zeolite Beta (Beta-C). The superior catalytic performance of Beta-MS is attributed to its hierarchical structure, which offers full accessibility to all catalytic active sites. In contrast, Beta-C was easily deactivated because a layer of coke quickly deposited on the outer surfaces of the catalyst crystals, impeding access to interior active sites. This difference is clearly demonstrated by using electron microscopy combined with electron energy loss spectroscopy to probe the distribution of coke in the deactivated catalysts. At both low and high conversions, ranging from 20% to 100%, Beta-MS gave higher selectivity towards higher aliphatics (C4-C7) but lower ethene selectivity compared to Beta-C. Therefore, we conclude that a hierarchical structure decreases the residence time of methylbenzenes in zeolite micropores, disfavoring the propagation of the aromatic-based catalytic cycle. This conclusion is consistent with a recent report on ZSM-5 and is also strongly supported by our analysis of soluble coke species residing in the catalysts. Moreover, we identified an oxygen-containing compound, 4-methyl-benzaldehyde, in the coke, which has not been observed in the MTH reaction before.  

  7. Coincidence Auger spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Penent, F. [LCPMR, Universite Pierre et Marie Curie, 75231 Paris 5 (France) and DIAM, Universite Pierre et Marie Curie, 75252 Paris 5 (France)]. E-mail: penent@ccr.jussieu.fr; Lablanquie, P. [LURE, Universite Paris Sud, 91898 Orsay (France); Hall, R.I. [DIAM, Universite Pierre et Marie Curie, 75252 Paris 5 (France); Palaudoux, J. [LCPMR, Universite Pierre et Marie Curie, 75231 Paris 5 (France); Ito, K. [Photon Factory, IMSS, KEK, Tsukuba 305-0801 (Japan); Hikosaka, Y. [Photon Factory, IMSS, KEK, Tsukuba 305-0801 (Japan); IMS, Okazaki 444-8585 (Japan); Aoto, T. [Photon Factory, IMSS, KEK, Tsukuba 305-0801 (Japan); Eland, J.H.D. [Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3DW (United Kingdom)

    2005-06-15

    Auger electron spectroscopy (AES) and photoelectron spectroscopy (PES) are (with X-ray emission spectroscopy, XES) powerful analytical tools for material science and gas phase studies. However, the interpretation of Auger spectra can be very difficult due to the number and complexity of the involved processes. A deeper analysis, that allows a better understanding of relaxation processes following inner shell ionization, is possible with coincidence Auger spectroscopy. This method gives a new insight into electron correlation and allows disentangling of complex Auger electron spectra. In this paper, we present some examples related to gas phase coincidence Auger electron spectroscopy using synchrotron radiation. The detection in coincidence of an Auger electron with a threshold photoelectron presents two main advantages which are good energy resolution and high coincidence count rates. This technique has also provided new results on double Auger decay processes. A further qualitative breakthrough has been made with the development of a new experimental set-up based on a magnetic bottle time-of-flight electron spectrometer. This opens up the field of multi-electron coincidence spectroscopy and allows a most detailed analysis with characterization of all possible decay pathways following inner shell ionization.

  8. Broadband Dielectric Spectroscopy on Human Blood

    CERN Document Server

    Wolf, M; Lunkenheimer, P; Loidl, A

    2011-01-01

    Dielectric spectra of human blood reveal a rich variety of dynamic processes. Achieving a better characterization and understanding of these processes not only is of academic interest but also of high relevance for medical applications as, e.g., the determination of absorption rates of electromagnetic radiation by the human body. The dielectric properties of human blood are studied using broadband dielectric spectroscopy, systematically investigating the dependence on temperature and hematocrit value. By covering a frequency range from 1 Hz to 40 GHz, information on all the typical dispersion regions of biological matter is obtained. We find no evidence for a low-frequency relaxation (alpha-relaxation) caused, e.g., by counterion diffusion effects as reported for some types of biological matter. The analysis of a strong Maxwell-Wagner relaxation arising from the polarization of the cell membranes in the 1-100 MHz region (beta-relaxation) allows for the test of model predictions and the determination of variou...

  9. Ellagic acid promotes A{beta}42 fibrillization and inhibits A{beta}42-induced neurotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Ying [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Yang, Shi-gao; Du, Xue-ting; Zhang, Xi; Sun, Xiao-xia; Zhao, Min [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Sun, Gui-yuan, E-mail: sungy2004@sohu.com [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Liu, Rui-tian, E-mail: rtliu@tsinghua.edu.cn [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China)

    2009-12-25

    Smaller, soluble oligomers of {beta}-amyloid (A{beta}) play a critical role in the pathogenesis of Alzheimer's disease (AD). Selective inhibition of A{beta} oligomer formation provides an optimum target for AD therapy. Some polyphenols have potent anti-amyloidogenic activities and protect against A{beta} neurotoxicity. Here, we tested the effects of ellagic acid (EA), a polyphenolic compound, on A{beta}42 aggregation and neurotoxicity in vitro. EA promoted A{beta} fibril formation and significant oligomer loss, contrary to previous results that polyphenols inhibited A{beta} aggregation. The results of transmission electron microscopy (TEM) and Western blot displayed more fibrils in A{beta}42 samples co-incubated with EA in earlier phases of aggregation. Consistent with the hypothesis that plaque formation may represent a protective mechanism in which the body sequesters toxic A{beta} aggregates to render them harmless, our MTT results showed that EA could significantly reduce A{beta}42-induced neurotoxicity toward SH-SY5Y cells. Taken together, our results suggest that EA, an active ingredient in many fruits and nuts, may have therapeutic potential in AD.

  10. Dosimetry of Low-Energy Beta Radiation

    DEFF Research Database (Denmark)

    Borg, Jette

    Useful techniques and procedures for derermination of absorbed doses from exposure in a low-energy beta radiation were studied and evaluated. The four techniques included were beta spectrometry, extrapolation chamber dosimetry, Monte Carlo (MC) calculations, and exoelectron dosimetry. As a typical...... low-energy beta radiation field a moderated spectrum from a carbon-14 source was used. The measured responce of a Si(Li) detector to photons (bremsstrahlung) showed fine agreemant with the MC calculated photon response, whereas the difference between measured and MC calculated response to electrons...

  11. Rotational beta expansion: Ergodicity and Soficness

    OpenAIRE

    Akiyama, Shigeki; Caalim, Jonathan

    2015-01-01

    We study a family of piecewise expanding maps on the plane, generated by composition of a rotation and an expansive similitude of expansion constant $\\beta$. We give two constants $B_1$ and $B_2$ depending only on the fundamental domain that if $\\beta>B_1$ then the expanding map has a unique absolutely continuous invariant probability measure, and if $\\beta>B_2$ then it is equivalent to $2$-dimensional Lebesgue measure. Restricting to a rotation generated by $q$-th root of unity $\\zeta$ with ...

  12. Falsifying Baryogenesis with Neutrinoless Double Beta Decay

    CERN Document Server

    Graf, Lukas

    2016-01-01

    We discuss the relation between lepton number violation at high and low energies, particularly, the constraints on baryogenesis models, which would be implied by an observation of neutrinoless double beta decay. The primordial baryon asymmetry can be washed out by effective lepton number violating operators triggering neutrinoless double beta decay in combination with sphaleron processes. A generic conclusion is that popular models of baryogenesis are excluded if a non-standard mechanism of neutrinoless double beta decay, i.e., other than the standard light neutrino exchange, is observed. Apart from the effective field approach, we also outline the possible extension of our arguments to a general UV-completed model.

  13. Beta-alanine synthesis in Escherichia coli.

    OpenAIRE

    Cronan, J. E.

    1980-01-01

    The enzyme, aspartate 1-decarboxylase (L-aspartate 1-carboxy-lyase; EC 4.1.1.15), that catalyzes the reaction aspartate leads to beta-alanine + CO2 was found in extracts of Escherichia coli. panD mutants of E. coli are defective in beta-alanine biosynthesis and lack aspartate 1-decarboxylase. Therefore, the enzyme functions in the biosynthesis of the beta-alanine moiety of pantothenate. The genetic lesion in these mutants is closely linked to the other pantothenate (pan) loci of E. coli K-12.

  14. Review of modern double beta decay experiments

    Science.gov (United States)

    Barabash, A. S.

    2015-10-01

    The review of modern experiments on search and studying of double beta decay processes is done. Results of the most sensitive current experiments are discussed. The main attention is paid to EXO-200, KamLAND-Zen, GERDA-I and CUORE-0 experiments. Modern values of T1/2(2ν) and best present limits on neutrinoless double beta decay and double beta decay with Majoron emission are presented. Conservative limits on effective mass of a Majorana neutrino ( at the level of ˜ 0.01-0.1 eV are discussed.

  15. Bound beta-decay: BOB

    International Nuclear Information System (INIS)

    For many years exotic decay modes of the neutron have been investigated as possible doorways to the exploration of new physics. The bound beta-decay (BOB) of the neutron into a hydrogen atom and an anti-neutrino offers a very elegant method to study neutrino helicities. However, this rare decay has not yet been observed for the free neutron, owing to the challenge of measuring a decay involving only electrically neutral particles and with an estimated branching ratio of only a few 106 of the three-body decay mode. During the past few years scientists from the TUM E18 Group have developed a novel experimental scheme which addresses all necessary problems associated with the observation of this two-body neutron decay in a very coherent way. The BOB experiment shall be installed at a tangential beam tube of a powerful research reactor such as the SR6 at the FRMII in Garching or H6-H7 beam tube at ILL. This talk will provide insights and ideas on how such an experiment is to be performed.

  16. Dopamine beta-hydroxylase deficiency

    Directory of Open Access Journals (Sweden)

    Senard Jean-Michel

    2006-03-01

    Full Text Available Abstract Dopamine beta-hydroxylase (DβH deficiency is a very rare form of primary autonomic failure characterized by a complete absence of noradrenaline and adrenaline in plasma together with increased dopamine plasma levels. The prevalence of DβH deficiency is unknown. Only a limited number of cases with this disease have been reported. DβH deficiency is mainly characterized by cardiovascular disorders and severe orthostatic hypotension. First symptoms often start during a complicated perinatal period with hypotension, muscle hypotonia, hypothermia and hypoglycemia. Children with DβH deficiency exhibit reduced ability to exercise because of blood pressure inadaptation with exertion and syncope. Symptoms usually worsen progressively during late adolescence and early adulthood with severe orthostatic hypotension, eyelid ptosis, nasal stuffiness and sexual disorders. Limitation in standing tolerance, limited ability to exercise and traumatic morbidity related to falls and syncope may represent later evolution. The syndrome is caused by heterogeneous molecular alterations of the DBH gene and is inherited in an autosomal recessive manner. Restoration of plasma noradrenaline to the normal range can be achieved by therapy with the synthetic precursor of noradrenaline, L-threo-dihydroxyphenylserine (DOPS. Oral administration of 100 to 500 mg DOPS, twice or three times daily, increases blood pressure and reverses the orthostatic intolerance.

  17. Neutron bound {beta}- decay- BOB

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, M.; Berger, M.; Emmerich, R.; Faestermann, T.; Gutsmiedl, E.; Hartmann, F.J.; Paul, S.; Ruschel, S.; Schoen, J.; Schott, W.; Schubert, U.; Trautner, A. [Physik-Department, TUM, 85748 Garching (Germany); Engels, R. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Fierlinger, P. [Excellence Cluster Universe, TUM, 85748 Garching (Germany); Hertenberger, R. [Sektion Physik, LMU, 85748 Garching (Germany); Roehrmoser, R. [FRM2, TUM, 85748 Garching (Germany); Udem, T. [Max-Planck-Institut fuer Quantenphysik, 85748 Garching (Germany)

    2011-07-01

    The bound neutron {beta}-decay(BOB) into a hydrogen atom and an electron antineutrino is investigated.The hyper-fine-state population of the monoenergetic hydrogen atoms (326.3 eV) yields the neutrino left-handed-ness or a possible right-handed admixture and possible small scalar and tensor contributions to the weak force. Preexperiments to measure the BOB H(2s) atoms have been done or are being set up using ionizer and RF discharge proton sources, a Wien filter, Cs and Ar cells, a spin filter, electric counter and accelerating fields, a double focusing magnet and a solar blind PM for the Lyman-{alpha} photons. In a first experiment, the charge exchange of the H(2s) atoms into H{sup -}, offering a selective method to discriminate these states against background, is investigated. In a second step the number of background H(2s) resulting from protons interacting with the walls of the experimental setup are determined. For this a quenching E field and a solar blind PM are used.

  18. Beta cell count instead of beta cell mass to assess and localize growth in beta cell population following pancreatic duct ligation in mice.

    Directory of Open Access Journals (Sweden)

    Marie Chintinne

    Full Text Available BACKGROUND: Pancreatic-tail duct ligation (PDL in adult rodents has been reported to induce beta cell generation and increase beta cell mass but increases in beta cell number have not been demonstrated. This study examines whether PDL increases beta cell number and whether this is caused by neogenesis of small clusters and/or their growth to larger aggregates. METHODOLOGY: Total beta cell number and its distribution over small (100 µm clusters was determined in pancreatic tails of 10-week-old mice, 2 weeks after PDL or sham. PRINCIPAL FINDINGS: PDL increased total beta cell mass but not total beta cell number. It induced neogenesis of small beta cell clusters (2.2-fold higher number which contained a higher percent proliferating beta cells (1.9% Ki67+cells than sham tails (<0.2%; their higher beta cell number represented <5% of total beta cell number and was associated with a similar increase in alpha cell number. It is unknown whether the regenerative process is causally related to the inflammatory infiltration in PDL-tails. Human pancreases with inflammatory infiltration also exhibited activation of proliferation in small beta cell clusters. CONCLUSIONS/SIGNIFICANCE: The PDL model illustrates the advantage of direct beta cell counts over beta cell mass measurements when assessing and localizing beta cell regeneration in the pancreas. It demonstrates the ability of the adult mouse pancreas for neogenesis of small beta cell clusters with activated beta cell proliferation. Further studies should investigate conditions under which neoformed small beta cell clusters grow to larger aggregates and hence to higher total beta cell numbers.

  19. Energetic, Structural, and Antimicrobial Analyses of [beta]-Lactam Side Chain Recognition by [beta]-Lactamases

    Energy Technology Data Exchange (ETDEWEB)

    Caselli, E.; Powers, R.A.; Blaszczak, L.C.; Wu, C.Y.E.; Prati, F.; Shoichet, B.K. (NWU)

    2010-03-05

    Penicillins and cephalosporins are among the most widely used and successful antibiotics. The emergence of resistance to these {beta}-lactams, most often through bacterial expression of {beta}-lactamases, threatens public health. To understand how {beta}-lactamases recognize their substrates, it would be helpful to know their binding energies. Unfortunately, these have been difficult to measure because {beta}-lactams form covalent adducts with {beta}-lactamases. This has complicated functional analyses and inhibitor design. To investigate the contribution to interaction energy of the key amide (R1) side chain of {beta}-lactam antibiotics, eight acylglycineboronic acids that bear the side chains of characteristic penicillins and cephalosporins, as well as four other analogs, were synthesized. These transition-state analogs form reversible adducts with serine {beta}-lactamases. Therefore, binding energies can be calculated directly from K{sub i} values. The K{sub i} values measured span four orders of magnitude against the Group I {beta}-lactamase AmpC and three orders of magnitude against the Group II {beta}-lactamase TEM-1. The acylglycineboronic acids have K{sub i} values as low as 20 nM against AmpC and as low as 390 nM against TEM-1. The inhibitors showed little activity against serine proteases, such as chymotrypsin. R1 side chains characteristic of {beta}-lactam inhibitors did not have better affinity for AmpC than did side chains characteristic of {beta}-lactam substrates. Two of the inhibitors reversed the resistance of pathogenic bacteria to {beta}-lactams in cell culture. Structures of two inhibitors in their complexes with AmpC were determined by X-ray crystallography to 1.90 {angstrom} and 1.75 {angstrom} resolution; these structures suggest interactions that are important to the affinity of the inhibitors. Acylglycineboronic acids allow us to begin to dissect interaction energies between {beta}-lactam side chains and {beta}-lactamases. Surprisingly

  20. Synthesis of mesoporous Beta and Sn-Beta zeolites and their catalytic performances.

    Science.gov (United States)

    Jin, Junjiang; Ye, Xinxin; Li, Yongsheng; Wang, Yanqin; Li, Liang; Gu, Jinlou; Zhao, Wenru; Shi, Jianlin

    2014-06-14

    Mesoporous Beta zeolite has been successfully prepared through hydrothermal synthesis in the presence of cationic ammonium-modified chitosan as the meso-template. Through a subsequent solid-gas reaction between highly dealuminated mesoporous Beta zeolite and SnCl4 steam at an elevated temperature, mesoporous Sn-Beta has been facilely obtained. It was revealed that the addition of cationic chitosan induced the nanocrystal aggregation to particle sizes of ∼300 nm, giving rise to the intercrystalline/interparticle mesoporosity. In the Sn-implanting procedure, Sn species were demonstrated to be doped into the framework of the resulting mesoporous Beta zeolite in a tetrahedral environment without structural collapse. Due to the micro/mesoporous structures, both mesoporous Beta and Sn-Beta exhibited superior performances in α-pinene isomerization, Baeyer-Villiger oxidation of 2-adamantanone by hydrogen peroxide and the isomerization of glucose in water, respectively.

  1. Pressure phase lines and enthalpies for the. cap alpha. -. beta. and. beta. -liquid transitions in beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Abey, A.

    1984-10-31

    The effect of hydrostatic pressure on the ..cap alpha..-..beta.. and ..beta..-liquid transition temperatures in Be was measured in a gas pressure system. Differential thermal analysis was used in the pressure range from 0.1 MPa to 0.7 GPa. For the ..cap alpha..-..beta.. transition, dT/dP = 43 +- 7 K/GPa; for the ..beta..-liquid transition, dT/dP = 35 +- 7 K/GPa. Although it is possible that large systematic errors may arise from experimental procedures, our results are seriously at odds with those of other investigators. Transition enthalpies for the ..cap alpha..-..beta.. and ..beta..-liquid transitions were 1.9 +- 0.2 and 2.2 +- 0.2 kcal/g.m., respectively, at a pressure of 0.1 MPa.

  2. Systematic Risk on Istanbul Stock Exchange: Traditional Beta Coefficient Versus Downside Beta Coefficient

    Directory of Open Access Journals (Sweden)

    Gülfen TUNA

    2013-03-01

    Full Text Available The aim of this study is to test the validity of Downside Capital Asset Pricing Model (D-CAPM on the ISE. At the same time, the explanatory power of CAPM's traditional beta and D-CAPM's downside beta on the changes in the average return values are examined comparatively. In this context, the monthly data for seventy three stocks that are continuously traded on the ISE for the period 1991-2009 is used. Regression analysis is applied in this study. The research results have shown that D-CAPM is valid on the ISE. In addition, it is obtained that the power of downside beta coefficient is higher than traditional beta coefficient on explaining the return changes. Therefore, it can be said that the downside beta is superior to traditional beta in the ISE for chosen period.

  3. A comparison of enzymatic phosphorylation and phosphatidylation of beta-L- and beta-D-nucleosides.

    Science.gov (United States)

    Birichevskaya, Larisa L; Kvach, Sergei V; Sivets, Grigorii G; Kalinichenko, Elena N; Zinchenko, Anatoly I; Mikhailopulo, Igor A

    2007-04-01

    Enzymatic 5'-monophosphorylation and 5'-phosphatidylation of a number of beta-L- and beta-D-nucleosides was investigated. The first reaction, catalyzed by nucleoside phosphotransferase (NPT) from Erwinia herbicola, consisted of the transfer of the phosphate residue from p-nitrophenylphosphate (p-NPP) to the 5'-hydroxyl group of nucleoside; the second was the phospholipase D (PLD)-catalyzed transphosphatidylation of L-alpha-lecithin with a series of beta-L- and beta-D-nucleosides as the phosphatidyl acceptor resulted in the formation of the respective phospholipid-nucleoside conjugates. Some beta-L-nucleosides displayed similar or even higher substrate activity compared to the beta-D-enantiomers. PMID:17206374

  4. Expression of transforming growth factor beta (TGF beta) receptors and expression of TGF beta 1, TGF beta 2 and TGF beta 3 in human small cell lung cancer cell lines

    DEFF Research Database (Denmark)

    Damstrup, L; Rygaard, K; Spang-Thomsen, M;

    1993-01-01

    A panel of 21 small cell lung cancer cell (SCLC) lines were examined for the presence of Transforming growth factor beta receptors (TGF beta-r) and the expression of TGF beta mRNAs. By the radioreceptor assay we found high affinity receptors to be expressed in six cell lines. scatchard analysis...... of the binding data demonstrated that the cells bound between 4.5 and 27.5 fmol mg-1 protein with a KD ranging from 16 to 40 pM. TGF beta 1 binding to the receptors was confirmed by cross-linking TGF beta 1 to the TGF beta-r. Three classes of TGF beta-r were demonstrated, type I and type II receptors with M......(r) = 65,000 and 90,000 and the betaglycan (type III) with M(r) = 280,000. Northern blotting showed expression of TGF beta 1 mRNA in ten, TGF beta 2 mRNA in two and TGF beta 3 mRNA in seven cell lines. Our results provide, for the first time, evidence that a large proportion of a broad panel of SCLC cell...

  5. Theoretical investigation on the inclusion of TCDD with {beta}-cyclodextrin by performing QM calculations and MD simulations

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Wenxiao [Key Lab of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, Shandong University, Jinan 250100 (China); Zhang, Dongju, E-mail: zhangdj@sdu.edu.cn [Key Lab of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, Shandong University, Jinan 250100 (China); Zhan, Jinhua [Key Lab of Colloid and Interface Chemistry, Ministry of Education, Institute of Theoretical Chemistry, Shandong University, Jinan 250100 (China)

    2011-09-15

    Highlights: {yields} We study the inclusion mechanism of TCDD with {beta}-CD by theoretical methods. {yields} Clearly, the formation of inclusion complex is an energetically driven process. {yields} The inclusion complex can be detected by IR and Raman techniques. {yields} The results imply that {beta}-CD may be used as a host molecule to enrich TCDD molecules. - Abstract: The rapid enrichment and detection of trace polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are currently challenging issues in the field of environmental science. In this paper, by performing quantum chemistry (QM) calculations and molecular dynamics (MD) simulations, we studied the inclusion complexation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a representative PCDD molecule, with {beta}-cyclodextrin ({beta}-CD), one of the widely used compounds in supramolecular chemistry. The calculated results reveal that the stable inclusion complex can be formed in both the gas phase and solvent, which proposes that {beta}-CD may serve as a potential substrate enriching TCDD. The calculated vibrational spectra indicate that the infrared (IR) and Raman spectroscopy may be suitable for the detection of {beta}-CD-modified TCDD. The present theoretical results may be informative to environmental scientists who are devoting themselves to developing effective methods for detection and treatment of POPs.

  6. Dielectric spectroscopy in agrophysics

    Science.gov (United States)

    Skierucha, W.; Wilczek, A.; Szypłowska, A.

    2012-04-01

    The paper presents scientific foundation and some examples of agrophysical applications of dielectric spectroscopy techniques. The aim of agrophysics is to apply physical methods and techniques for studies of materials and processes which occur in agriculture. Dielectric spectroscopy, which describes the dielectric properties of a sample as a function of frequency, may be successfully used for examinations of properties of various materials. Possible test materials may include agrophysical objects such as soil, fruit, vegetables, intermediate and final products of the food industry, grain, oils, etc. Dielectric spectroscopy techniques enable non-destructive and non-invasive measurements of the agricultural materials, therefore providing tools for rapid evaluation of their water content and quality. There is a limited number of research in the field of dielectric spectroscopy of agricultural objects, which is caused by the relatively high cost of the respective measurement equipment. With the fast development of modern technology, especially in high frequency applications, dielectric spectroscopy has great potential of expansion in agrophysics, both in cognitive and utilitarian aspects.

  7. Neutrino potential for neutrinoless double beta decay

    CERN Document Server

    Iwata, Yoritaka

    2016-01-01

    Neutrino potential for neutrinoless double beta decay is studied with focusing on its statistical property. The statistics provide a gross view of understanding amplitude of constitutional components of the nuclear matrix element.

  8. Literature in Focus Beta Beams: Neutrino Beams

    CERN Multimedia

    2009-01-01

    By Mats Lindroos (CERN) and Mauro Mezzetto (INFN Padova, Italy) Imperial Press, 2009 The beta-beam concept for the generation of electron neutrino beams was first proposed by Piero Zucchelli in 2002. The idea created quite a stir, challenging the idea that intense neutrino beams only could be produced from the decay of pions or muons in classical neutrino beams facilities or in future neutrino factories. The concept initially struggled to make an impact but the hard work by many machine physicists, phenomenologists and theoreticians over the last five years has won the beta-beam a well-earned position as one of the frontrunners for a possible future world laboratory for high intensity neutrino oscillation physics. This is the first complete monograph on the beta-beam concept. The book describes both technical aspects and experimental aspects of the beta-beam, providing students and scientists with an insight into the possibilities o...

  9. Probing neutrinoless double beta decay with SNO+

    CERN Document Server

    Arushanova, Evelina

    2015-01-01

    Probing neutrinoless double beta decay is one of the primary goals for SNO+, SNOLAB's multi-purpose neutrino detector. In order to achieve this goal the SNO detector has been adapted so that it can be filled with Te-loaded liquid scintillator. During the initial double beta phase the target loading is 0.3% natural Te, which equates to $\\sim790$ kg of double beta isotope. Estimating the sensitivity to neutrinoless double beta decay requires a well understood background model. For SNO+ this is provided by a comprehensive study considering all possible background contributions, whether they originate from within the liquid scintillator cocktail, the surrounding parts of the detector or other irreducible backgrounds. Given these considerations, for five years running in the initial phase, the expected sensitivity is $T_{1/2}^{0\

  10. Review of modern double beta decay experiments

    Energy Technology Data Exchange (ETDEWEB)

    Barabash, A. S., E-mail: barabash@itep.ru [Institute of Theoretical and Experimental Physics (NRC ”Kurchatov Institute”), B. Cheremushkinskaya 25, Moscow (Russian Federation)

    2015-10-28

    The review of modern experiments on search and studying of double beta decay processes is done. Results of the most sensitive current experiments are discussed. The main attention is paid to EXO-200, KamLAND-Zen, GERDA-I and CUORE-0 experiments. Modern values of T{sub 1/2}(2ν) and best present limits on neutrinoless double beta decay and double beta decay with Majoron emission are presented. Conservative limits on effective mass of a Majorana neutrino (〈m{sub ν}〉 < 0.46 eV) and a coupling constant of Majoron to neutrino (〈g{sub ee}〉 < 1.3 · 10{sup −5}) are obtained. Prospects of search for neutrinoless double beta decay in new experiments with sensitivity to 〈m{sub ν}〉 at the level of ∼ 0.01-0.1 eV are discussed.

  11. Solid-state NMR analysis of the {beta}-strand orientation of the protofibrils of amyloid {beta}-protein

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Takashi [Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Masuda, Yuichi, E-mail: masuda@mail.pharm.tohoku.ac.jp [Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai 980-8578 (Japan); Irie, Kazuhiro [Graduate School of Agriculture, Kyoto University, Kyoto 606-8502 (Japan); Akagi, Ken-ichi; Monobe, Youko; Imazawa, Takayoshi [Section of Laboratory Equipment, Division of Biomedical Research, National Institute of Biomedical Innovation, Osaka 567-0085 (Japan); Takegoshi, K. [Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan)

    2012-11-30

    Highlights: Black-Right-Pointing-Pointer The supramolecular structure of A{beta}42 protofibrils was analyzed by solid-state NMR. Black-Right-Pointing-Pointer The Ala-21 residue in the A{beta}42 protofibrils is included in a slightly disordered {beta}-strand. Black-Right-Pointing-Pointer The A{beta}42 protofibrils do not form intermolecular in-register parallel {beta}-sheets. -- Abstract: Alzheimer's disease (AD) is caused by abnormal deposition (fibrillation) of a 42-residue amyloid {beta}-protein (A{beta}42) in the brain. During the process of fibrillation, the A{beta}42 takes the form of protofibrils with strong neurotoxicity, and is thus believed to play a crucial role in the pathogenesis of AD. To elucidate the supramolecular structure of the A{beta}42 protofibrils, the intermolecular proximity of the Ala-21 residues in the A{beta}42 protofibrils was analyzed by {sup 13}C-{sup 13}C rotational resonance experiments in the solid state. Unlike the A{beta}42 fibrils, an intermolecular {sup 13}C-{sup 13}C correlation was not found in the A{beta}42 protofibrils. This result suggests that the {beta}-strands of the A{beta}42 protofibrils are not in an in-register parallel orientation. A{beta}42 monomers would assemble to form protofibrils with the {beta}-strand conformation, then transform into fibrils by forming intermolecular parallel {beta}-sheets.

  12. Genetic counselling in the beta-thalassaemias

    OpenAIRE

    Ioannides, Adonis S.

    2013-01-01

    The beta-thalassaemias are very important genetic disorders of haemoglobin synthesis and are amongst the commonest monogenic disorders. In view of the severity of beta-thalassaemia major, a number of screening programmes have been developed aimed at reducing the number of individuals born with the condition. Genetic counsellingplays a vital role in this process supporting the successful implementation of screening and delineating available options to at risk individuals. This review assesses ...

  13. Searches for neutrinoless double beta decay

    Science.gov (United States)

    Schwingenheuer, Bernhard

    2012-07-01

    Neutrinoless double beta decay is a lepton number violating process whose observation would also establish that neutrinos are their own anti-particles. There are many experimental efforts with a variety of techniques. Some (EXO, Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has reported the first measurement of the half life for the double beta decay with two neutrinos of 136Xe. The sensitivities of the different proposals are reviewed.

  14. Searches for neutrinoless double beta decay

    CERN Document Server

    Schwingenheuer, B

    2012-01-01

    Neutrinoless double beta decay is a lepton number violating process whose observation would also establish that neutrinos are their own anti-particles. There are many experimental efforts with a variety of techniques. Some (EXO, Kamland-Zen, GERDA phase I and CANDLES) started take data in 2011 and EXO has reported the first measurement of the half life for the double beta decay with two neutrinos of $^{136}$Xe. The sensitivities of the different proposals are reviewed.

  15. Peripheral beta-endorphin and pain modulation.

    OpenAIRE

    Hartwig, A. C.

    1991-01-01

    Beta-endorphin is a peptide with morphine-like effects produced primarily in the anterior lobe of the pituitary gland. After its cleavage from the parent molecule, proopiomelanocortin, beta-endorphin is circulated via the blood stream to interact with specific opioid receptors located throughout the body. The peptide produces analgesia by inhibiting the firing of peripheral somatosensory fibers. It also affects other senses, such as vision, hearing, and smell. Whereas the ability to increase ...

  16. Unexpected pattern of beta-globin mutations in beta-thalassaemia patients from northern Portugal

    OpenAIRE

    Cabeda, J.; Correia, C.; Estevinho, A.; Simões, C.; Amorim, M; L. Pinho; Justiça, B

    1999-01-01

    We characterized the genetic nature of beta-thalassaemia in northern Portugal. Of the 164 patients studied three were beta-thalassaemia major cases (one IVS-1-6/beta degrees 39 and two homozygous IVS-1-110). The analysis of the frequency of each mutation in the families revealed that the codon 6(-A) mutation was unexpectedly frequent (40%) and associated with the beta-globin haplotype E, and not with the usual European and North African CD6(-A) haplotypes. In contrast, the frequency of IVS-1-...

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

    DEFF Research Database (Denmark)

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

    1976-01-01

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

  18. Laser assisted decay spectroscopy at the CRIS beam line at ISOLDE

    International Nuclear Information System (INIS)

    The new collinear resonant ionization spectroscopy (Cris) experiment at Isolde, Cern uses laser radiation to stepwise excite and ionize an atomic beam for the purpose of ultra-sensitive detection of rare isotopes and hyperfine structure measurements. The technique also offers the ability to purify an ion beam that is contaminated with radioactive isobars, including the ground state of an isotope from its isomer. A new program using the Cris technique to select only nuclear isomeric states for decay spectroscopy commenced last year. The isomeric ion beam is selected using a resonance within its hyperfine structure and subsequently deflected to a decay spectroscopy station. This consists of a rotating wheel implantation system for alpha and beta decay spectroscopy, and up to three high purity germanium detectors for gamma-ray detection. This paper gives an introduction to the Cris technique, the current status of the laser assisted decay spectroscopy set-up and recent results from the experiment in November 2011.

  19. Toward beta cell replacement for diabetes.

    Science.gov (United States)

    Johannesson, Bjarki; Sui, Lina; Freytes, Donald O; Creusot, Remi J; Egli, Dieter

    2015-04-01

    The discovery of insulin more than 90 years ago introduced a life-saving treatment for patients with type 1 diabetes, and since then, significant progress has been made in clinical care for all forms of diabetes. However, no method of insulin delivery matches the ability of the human pancreas to reliably and automatically maintain glucose levels within a tight range. Transplantation of human islets or of an intact pancreas can in principle cure diabetes, but this approach is generally reserved for cases with simultaneous transplantation of a kidney, where immunosuppression is already a requirement. Recent advances in cell reprogramming and beta cell differentiation now allow the generation of personalized stem cells, providing an unlimited source of beta cells for research and for developing autologous cell therapies. In this review, we will discuss the utility of stem cell-derived beta cells to investigate the mechanisms of beta cell failure in diabetes, and the challenges to develop beta cell replacement therapies. These challenges include appropriate quality controls of the cells being used, the ability to generate beta cell grafts of stable cellular composition, and in the case of type 1 diabetes, protecting implanted cells from autoimmune destruction without compromising other aspects of the immune system or the functionality of the graft. Such novel treatments will need to match or exceed the relative safety and efficacy of available care for diabetes.

  20. Neoclassical transport in high {beta} tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Cowley, S.C.

    1992-12-01

    Neoclassical, transport in high {beta} large aspect ratio tokamaks is calculated. The variational method introduced by Rosenbluth, et al., is used to calculate the full Onsager matrix in the banana regime. These results are part of a continuing study of the high {beta} large aspect ratio equilibria introduced in Cowley, et al. All the neoclassical coefficients are reduced from their nominal low {beta} values by a factor ({var_epsilon}/q{sup 2}{beta}){sup {1/2}} II. This factor is the ratio of plasma volume in the boundary layer to the volume in the core. The fraction of trapped particles on a given flux surface (f{sub t}) is also reduced by this factor so that {approximately} {sub ({var_epsilon}}/q{sup 2}{beta}){sup {1/2}}. Special attention is given to the current equation, since this is thought to be relevant at low 3 and therefore may also be relevant at high {beta}. The bootstrap current term is found to exceed the actual current by a factor of the square root of the aspect ratio.

  1. Vibrational Spectroscopy of Biomembranes

    Science.gov (United States)

    Schultz, Zachary D.; Levin, Ira W.

    2011-07-01

    Vibrational spectroscopy, commonly associated with IR absorption and Raman scattering, has provided a powerful approach for investigating interactions between biomolecules that make up cellular membranes. Because the IR and Raman signals arise from the intrinsic properties of these molecules, vibrational spectroscopy probes the delicate interactions that regulate biomembranes with minimal perturbation. Numerous innovative measurements, including nonlinear optical processes and confined bilayer assemblies, have provided new insights into membrane behavior. In this review, we highlight the use of vibrational spectroscopy to study lipid-lipid interactions. We also examine recent work in which vibrational measurements have been used to investigate the incorporation of peptides and proteins into lipid bilayers, and we discuss the interactions of small molecules and drugs with membrane structures. Emerging techniques and measurements on intact cellular membranes provide a prospective on the future of vibrational spectroscopic studies of biomembranes.

  2. Spectroscopy for the Masses

    Science.gov (United States)

    Le Roy, Robert J.; Hopkins, Scott; Power, William P.; Leung, Tong; Hepburn, John

    2015-06-01

    Undergraduate students in all areas of science encounter one or more types of spectroscopy as an essential tool in their discipline, but most never take the advanced physics or chemistry courses in which the subject is normally taught. To address this problem, for over 20 years our department has been teaching a popular Introductory Spectroscopy course that assumes as background only a one-term introductory chemistry course containing a unit on atomic theory, and a familiarity with rudimentary calculus. This survey course provides an introduction to microwave, infrared, Raman, electronic, photoelectron and NMR spectroscopy in a manner that allows students to understand many of these phenomena as intuitive generalizations of the problem of a particle in a 1-D box or a particle-on-a-ring, and does not require any high level mathematics.

  3. Chiral Rotational Spectroscopy

    CERN Document Server

    Cameron, Robert P; Barnett, Stephen M

    2015-01-01

    We introduce chiral rotational spectroscopy: a new technique that enables the determination of the individual optical activity polarisability components $G_{XX}'$, $G_{YY}'$, $G_{ZZ}'$, $A_{X,YZ}$, $A_{Y,ZX}$ and $A_{Z,XY}$ of chiral molecules, in a manner that reveals the enantiomeric constitution of a sample whilst yielding an incisive signal even for a racemate. Chiral rotational spectroscopy could find particular use in the analysis of molecules that are chiral by virtue of their isotopic constitution and molecules with multiple chiral centres. The principles that underpin chiral rotational spectroscopy can also be exploited in the search for molecular chirality in space, which, if found, may add weight to hypotheses that biological homochirality and indeed life itself are of cosmic origin.

  4. Terahertz Spectroscopy and Imaging

    CERN Document Server

    Zeitler, Axel; Kuwata-Gonokami, Makoto

    2013-01-01

    "This book presents the current state of knowledge in the field of terahertz spectroscopy, providing a comprehensive source of information for beginners and experienced researchers alike whose interests lie in this area. The book aims to explain the fundamental physics that underpins terahertz  technology and to describe its key applications. Highlights of scientific research in the field of terahertz science are also outlined in some chapters, providing an overview as well as giving an insight into future directions for research.  Over the past decade terahertz spectroscopy has developed into one of the most rapidly growing areas of its kind, gaining an important impact across a wide range of scientific disciplines. Due to substantial advances in femtosecond laser technology, terahertz time-domain spectroscopy (THz-TDS) has established itself as the dominant spectroscopic technique for experimental scientists interested in measurements at this frequency range. In solids and liquids THz radiation is in reso...

  5. Instrumentation for Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    The indigenous efforts in instrumentation for Moessbauer spectroscopy are reviewed. After a brief recapitulation of early developments in this field, the current status is described. Instrumentation for Moessbauer spectroscopy involves various aspects such as, velocity transducer, preparation of the radioactive source in proper host matrix, gamma-ray detectors, electron detectors in the case of conversion electron Moessbauer spectroscopy, data acquisition system, temperature variation facility such as cryostats and furnaces, externally applied magnetic field, etc. While the review attempts to cover most of these aspects, the constituents of a basic modern Moessbauer spectrometer, viz. a constant accelerator Moessbauer drive, a top loading type liquid helium cryostat and an inexpensive microprocessor based data acquisition system are discussed in detail. Developments in personal computer based systems are also indicated. (author). 10 figs., 61 refs

  6. Possible errors in assay for beta-glycosidase activity.

    OpenAIRE

    Chadwick, R W; Allison, J C; Talley, D L; George, S.E.

    1995-01-01

    Cecal homogenates were assayed for the enzymes beta-glucosidase, beta-glucuronidase, and beta-galactosidase. Anaerobic incubation with the addition of excess 3,4-dichloronitrobenzene, a substrate for nitroreductase, significantly increased the detection of the beta-glycosidase enzymes' activities.

  7. Continuous and Jump Betas: Implications for Portfolio Diversification

    Directory of Open Access Journals (Sweden)

    Vitali Alexeev

    2016-06-01

    Full Text Available Using high-frequency data, we decompose the time-varying beta for stocks into beta for continuous systematic risk and beta for discontinuous systematic risk. Estimated discontinuous betas for S&P500 constituents between 2003 and 2011 generally exceed the corresponding continuous betas. We demonstrate how continuous and discontinuous betas decrease with portfolio diversification. Using an equiweighted broad market index, we assess the speed of convergence of continuous and discontinuous betas in portfolios of stocks as the number of holdings increase. We show that discontinuous risk dissipates faster with fewer stocks in a portfolio compared to its continuous counterpart.

  8. Theoretical spectroscopy of quasars within Karlsson's law

    CERN Document Server

    Moret-Bailly, Jacques

    2016-01-01

    The law introduced by Karlsson in spectroscopy of low-redshift quasars involves the Lyman spectrum of hydrogen atoms. Thus, it appears necessary to study the concepts introduced by a standard spectroscopy of quasars, studied here, with those deducted from $\\Lambda$-CDM.A visible absorption of a sharp and saturated spectral line in a gas requires a long path without perturbations as collisions or cosmological redshift. Spectra of absorbed, saturated lines of quasars obeying Karlsson's law mainly result from interactions of natural, thermal light radiated by quasar with relatively cold, low presure atomic hydrogen. These lines are produced by three processes: a) A conventional absorption in a relatively cold gas produces a set of lines; b) These lines are multiplied by absorption after fundamental 3K or 4K redshifts, where K is Karlsson's constant: Spectra show that redshifts 3K (or 4K) exactly bring absorbed Lyman beta (or gamma) line on Lyman alpha: redshift almost disappears, and gas lines are intensely abso...

  9. Semiflexible Chain Networks Formed via Self-Assembly of Beta-Hairpin Molecules

    Science.gov (United States)

    Ozbas, Bulent; Rajagopal, Karthikan

    2005-03-01

    We present experimental results from a de novo designed oligopeptide that intermolecularly self-assembles into rigid hydrogel networks after an intramolecular folding event. The effect of ionic strength and beta hairpin peptide strand length on beta-sheet formation, self-assembly and resultant rheological properties were studied. The peptide molecules are locally amphiphilic with two linear strands of alternating hydrophobic valine and hydrophilic lysine amino acids flanking a central turn sequence. The beta-sheet formation of 24, 20, 16 and 12 amino acid long beta-hairpin molecules were studied by CD spectroscopy. The network properties and the nanostructure of the hydrogels were studied by rheology, TEM and SANS. The hydrogel network is composed of semiflexible fibrillar assemblies with viscoelastic behavior that follows the theoretical prediction for heavily crosslinked,semi-flexible polymer networks. SANS results show that the cross-sectional diameter of the fibrils, and thus, the bending modulus of the chains can be varied by changing the number of amino acids of strands of the molecules. Rheological measurements reveal that rigidity, creep and relaxation behavior of the hydrogels vary with the magnitude of stimulus and with the cross-section diameter of the chains.

  10. Rheumatoid factors from patients with rheumatoid arthritis react with Des-Lys58-beta 2m, modified beta 2-microglobulin

    DEFF Research Database (Denmark)

    Williams, R C; Nissen, Mogens Holst; Malone, C C

    1993-01-01

    -cleaved beta 2m and Des-Lys58-beta 2m) appeared to parallel the previously determined beta 2m single amino acid specificities, in that RF showing strong reactivity with Lysine 58 also showed a significant diminished reactivity with the Des-Lys58-beta 2m lacking the critical lysine residue. The present...

  11. beta-adrenoceptor density in chronic infarcted myocardium : a subtype specific decrease of beta(1)-adrenoceptor density

    NARCIS (Netherlands)

    Anthonio, RL; Brodde, OE; van Veldhuisen, DJ; Crijns, HJGM; van Gilst, WH

    2000-01-01

    beta-adrenoceptor density is altered in different cardiac diseases. In heart failure beta-adrenoceptor density is down regulated but in acute myocardial ischemia beta-adrenoceptor density is up regulated. In hearts with myocardial infarction total beta-adrenoceptor density is decreased shortly after

  12. Characterization of beta-R1, a gene that is selectively induced by interferon beta (IFN-beta) compared with IFN-alpha.

    Science.gov (United States)

    Rani, M R; Foster, G R; Leung, S; Leaman, D; Stark, G R; Ransohoff, R M

    1996-09-13

    We report preliminary characterization of a gene designated beta-R1, which is selectively expressed in response to interferon beta (IFN-beta) compared with IFN-alpha. In human astrocytoma cells, beta-R1 was induced to an equivalent extent by 10 IU/mL IFN-beta or 2500 IU/mL IFN-alpha2. To address the mechanism of this differential response, we analyzed induction of the beta-R1 gene in fibrosarcoma cells and derivative mutant cells lacking components required for signaling by type I IFNs. beta-R1 was readily induced by IFN-beta in the parental 2fTGH cell line, but not by recombinant IFN-alpha2, IFN-alpha Con1, or a mixture of IFN-alpha subtypes. IFN-alpha8 induced beta-R1 weakly. beta-R1 was not induced by IFN-beta in mutant cell lines U2A, U3A, U4A, and U6A, which lack, respectively, p48, STAT1, JAK1, and STAT2. U5A cells, which lack the Ifnar 2.2 component of the IFN-alpha and -beta receptor, also failed to express beta-R1. U1A cells are partially responsive to IFN-beta and IFN-alpha8 but lacked beta-R1 expression, indicating that TYK2 protein is essential for induction of this gene. Taken together, these results suggest that the expression of beta-R1 in response to type I IFN requires IFN-stimulated gene factor 3 plus an additional component, which is more efficiently formed on induction by IFN-beta compared with IFN-alpha.

  13. Genetic analysis of beta1 integrin "activation motifs" in mice

    DEFF Research Database (Denmark)

    Czuchra, Aleksandra; Meyer, Hannelore; Legate, Kyle R;

    2006-01-01

    /beta tails, leading to tail separation and integrin activation. We analyzed mice in which we mutated the tyrosines of the beta1 tail and the membrane-proximal aspartic acid required for the salt bridge. Tyrosine-to-alanine substitutions abolished beta1 integrin functions and led to a beta1 integrin...... and the membrane-proximal salt bridge between alpha and beta1 tails have no apparent function under physiological conditions in vivo....

  14. Beta-Negative Binomial Process and Poisson Factor Analysis

    OpenAIRE

    Zhou, Mingyuan; Hannah, Lauren; Dunson, David; Carin, Lawrence

    2011-01-01

    A beta-negative binomial (BNB) process is proposed, leading to a beta-gamma-Poisson process, which may be viewed as a "multi-scoop" generalization of the beta-Bernoulli process. The BNB process is augmented into a beta-gamma-gamma-Poisson hierarchical structure, and applied as a nonparametric Bayesian prior for an infinite Poisson factor analysis model. A finite approximation for the beta process Levy random measure is constructed for convenient implementation. Efficient MCMC computations are...

  15. Investigation of the Si doping effect in {beta}-Ga{sub 2}O{sub 3} films by co-sputtering of gallium oxide and Si

    Energy Technology Data Exchange (ETDEWEB)

    Takakura, Kenichiro, E-mail: takakura@kumamoto-nct.ac.jp [Kumamoto National College of Technology, 2659-2 Suya, Koushi, Kumamoto 862-1102 (Japan); Funasaki, Suguru; Tsunoda, Isao; Ohyama, Hidenori [Kumamoto National College of Technology, 2659-2 Suya, Koushi, Kumamoto 862-1102 (Japan); Takeuchi, Daisuke [National Institute of Advanced Industrial Science and Technology, 1-1-1, Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Nakashima, Toshiyuki [Chuo Denshi Kogyo Co. Ltd., 4-3-1 Taishido Setagaya Tokyo 154-0004 (Japan); Shibuya, Mutsuo [Echo Mother, 312-2 Toriko, Nishihara, Aso-gun, Kumamoto 861-2401 (Japan); Murakami, Katsuya [Japan Gas Chemi, 995-1, Futa, Nishihara, Aso-gun, Kumamoto 861-2403 (Japan); Simoen, Eddy [Imec, Kapeldreef 75, B-3001 Leuven (Belgium); Claeys, Cor [Imec, Kapeldreef 75, B-3001 Leuven (Belgium); E. E. Department, KU Leuven, B-3001 Leuven (Belgium)

    2012-08-01

    A transparent electrode of Si doped {beta}-Ga{sub 2}O{sub 3} films for solar cells, flat panel displays and other devices, which consists of chemically abundant and ecological friendly elements of gallium and oxygen, was grown on silicon substrates by RF magnetron sputtering using sintered Ga{sub 2}O{sub 3} and Si target. The Si composition in the {beta}-Ga{sub 2}O{sub 3} film is determined by electron dispersive X-ray spectroscopy. The X-ray photoelectron spectroscopy peak ratio of oxygen over gallium decreases with increasing Si content. It is concluded that Si substitutes for the Ga sites in the {beta}-Ga{sub 2}O{sub 3} film.

  16. FTIR Rotational Spectroscopy.

    Science.gov (United States)

    Woods, Ron; Henderson, Giles

    1987-01-01

    Presented are representative examples of the spectra and the analyses for a linear molecule (HC1), a symmetric top molecule (NH3), and an asymmetric top (H2O). Any combination of these projects could be incorporated in a physical chemistry or molecular spectroscopy laboratory. (RH)

  17. Spectroscopy with Supersonic Jets.

    Science.gov (United States)

    Skinner, Anne R.; Chandler, Dean W.

    1980-01-01

    Discusses a new technique that enables spectroscopists to study gas phase molecules at temperatures below 1 K, without traditional cryogenic apparatus. This technique uses supersonic jets as samples for gas molecular spectroscopy. Highlighted are points in the theory of supersonic flow which are important for applications in molecular…

  18. Spectroscopy of new particles

    Energy Technology Data Exchange (ETDEWEB)

    Goldhaber, G.

    1977-08-01

    A review of the spectroscopy of the ''psions'' with hidden charm or charm quantum number ch = o is followed by a discussion of charmed mesons and baryons. The anomalous C-..mu.. events and the heavy lepton hypothesis are briefly considered. (SDF)

  19. Properties of low-lying intruder states in 34Aland 34Sipopulated in the beta-decay of 34Mg

    CERN Document Server

    Lică, R; Negoită, F; Grévy, S; Mărginean, N; Desagne, Ph; Stora, T; Borcea, C; Borcea, R; Călinescu, S; Daugas, J M; Filipescu, D; Kuti, I; Fraile, L M; Franchoo, S; Gheorghe, I; Ghită, D G; Mărginean, R; Mihai, C; Mourface, P; Morel, P; Mrazek, J; Negret, A; Pietreanu, D; Sava, T; Sohler, D; Stănoiu, M; Stefan, I; Şuvăilă, R; Toma, S; Ur, C A

    2015-01-01

    The results of the IS530 experiment at ISOLDE revealed new information concerning several nuclei close to the N ≈ 20 'Island of Inversion' - 34Mg, 34Al, 34Si. The half-life of 34Mgwas found to be three times larger than the adopted value (63(1) ms instead of 20(10) ms). The beta-gamma spectroscopy of 34Mgperformed for the first time in this experiment, led to the first experimental level scheme for 34Al, also showing that the full beta strength goes through the predicted 1+ isomer in 34Al[1] and/or excited states that deexcite to it. The subsequent beta-decay of the 1+ isomer in 34Alallowed the observation of new gamma lines in 34Si, (tentatively) associated with low-spin high-energy excited states previously unobserved.

  20. Beta Gyres in Global Analysis Fields

    Institute of Scientific and Technical Information of China (English)

    Sun-Hee KIM; H.Joe KWON; R.L.ELSBERRY

    2009-01-01

    A three-component decomposition is applied to global analysis data to show the existence of a beta gyre,which causes Tropical Cyclone (TC) to drift from a large-scale environmental steering current.Analyses from the Global Data Assimilation and Prediction System (GDAPS) of the Korea Meteorological Administration (KMA),the Global Forecast System (GFS) of NCEP,and the Navy Operational Global Atmospheric Prediction System (NOGAPS) are used in this study.The structure of the beta gyre obtained in our analyses is in good agreement with the theoretical structure,with a cyclonic circulation to the southwest of the TC center,an anticyclonic circulation to the northeast,and a ventilation flow directed northwestward near the center.The circulation of the beta gyre is strongest at the 850-hPa level where the cyclonically swirling primary circulation is strongest,and decreases with height,in a pyramid shape similar to the primary circulation.The individual structure of the beta gyre is case- and model-dependent.At a certain analysis time,one model may clearly reveal a well-defined beta gyre,but the other models may not.Within one model,the beta gyre may be well defined at some analysis times,but not at other times.The structure of the beta gyre in the analysis field is determined by the nature of the vortex initialization scheme and the model behavior during the 6-h forecast in the operational data assimilation cycle.

  1. Beta-adrenoceptors in obstetrics and gynecology.

    Science.gov (United States)

    Modzelewska, Beata

    2016-01-01

    One hundred and twenty years after the description of extracts from the adrenal medulla, the use of beta-blockers and beta-agonists evolved from antianginal drugs and tocolytics to ligand-directed signaling. Beta-blockers in the fields of obstetrics and gynecology have so far been limited to the consideration of continuing treatment of disorders of the cardiovascular system and other dysfunctions that started before pregnancy. Studies in recent years have shown that beta-adrenoceptor signaling might be crucial in carcinogenesis and metastasis, apoptosis and anoikis. On the other hand, the use of beta-adrenoceptor agonists in tocolysis is, as yet, the primary method for inhibiting premature uterine contractions. Unfortunately, the efficacy of current pharmacological treatment for the management of preterm labor is regularly questioned. Moreover, studies related to non-pregnant myometrium performed to date indicate that the rhythmic contractions of the uterus are required for menstruation and have an important role in human reproduction. In turn, abnormal uterine contractility has been linked to dysmenorrhea, a condition associated with painful uterine cramping. The benefits of the use of beta2-adrenoceptor agonists in dysmenorrhea are still unclear and should be balanced against a wide range of adverse effects recognized with this class of medication. The ideal tocolytic agent is one which is effective for the pregnant or non-pregnant woman but has no side effects on either the woman or the baby. Looking to the future with both caution and hope, the potential metamorphosis of beta3-adrenoceptor agonists from experimental tools into therapeutic drugs for tocolysis warrants attention.

  2. Oligomerization and toxicity of A{beta} fusion proteins

    Energy Technology Data Exchange (ETDEWEB)

    Caine, Joanne M., E-mail: Jo.Caine@csiro.au [CSIRO Materials Science and Engineering and the Preventive Health Flagship, Parkville, Victoria (Australia); Bharadwaj, Prashant R. [CSIRO Materials Science and Engineering and the Preventive Health Flagship, Parkville, Victoria (Australia); Centre for Excellence for Alzheimer' s Disease Research and Care, School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Western Australia (Australia); Sankovich, Sonia E. [CSIRO Materials Science and Engineering and the Preventive Health Flagship, Parkville, Victoria (Australia); Ciccotosto, Giuseppe D. [The Department of Pathology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria 3010 (Australia); Streltsov, Victor A.; Varghese, Jose [CSIRO Materials Science and Engineering and the Preventive Health Flagship, Parkville, Victoria (Australia)

    2011-06-10

    Highlights: {yields} We expressed amyloid-{beta} (A{beta}) peptide as a soluble maltose binding protein fusion (MBP-A{beta}42 and MBP-A{beta}16). {yields} The full length A{beta} peptide fusion, MBP-A{beta}42, forms oligomeric species as determined by SDS-PAGE gels, gel filtration and DLS. {yields} The MBP-A{beta}42, but not MBP-A{beta}16 or MBP alone, is toxic to both yeast and mammalian cells as determined by toxicity assays. -- Abstract: This study has found that the Maltose binding protein A{beta}42 fusion protein (MBP-A{beta}42) forms soluble oligomers while the shorter MBP-A{beta}16 fusion and control MBP did not. MBP-A{beta}42, but neither MBP-A{beta}16 nor control MBP, was toxic in a dose-dependent manner in both yeast and primary cortical neuronal cells. This study demonstrates the potential utility of MBP-A{beta}42 as a reagent for drug screening assays in yeast and neuronal cell cultures and as a candidate for further A{beta}42 characterization.

  3. Chemistry and structure of beta silicon carbide implanted with high-dose aluminum. [168 keV

    Energy Technology Data Exchange (ETDEWEB)

    Du, Honghua; Yang, Zunde; Libera, M. (Stevens Inst. of Tech., Hoboken, NJ (United States). Dept. of Materials Science and Engineering); Jacobson, D.C. (AT and T Bell Laboratories, Murray Hill, NJ (United States)); Wang, Yu C.; Davis, R.F. (North Carolina State Univ., Raleigh, NC (United States). Dept. of Materials Science and Engineering)

    1993-02-01

    Single-crystal [beta]-SiC was implanted with aluminum to 3.90 x 10[sup 17] ions/cm[sup 2] at 168 keV at 773 K. The resultant compositional and structural characteristics were studied by Rutherford backscattering spectrometry. Auger electron spectroscopy, X-ray photoelectron spectroscopy, and cross-sectional transmission electron microscopy. No aluminum redistribution was observed during implantation. The Si-to-C ratio exhibited a negative deviation from unity in the implanted region. The shift in the photoelectron binding energies indicated the formation of aluminum carbide. The studies by electron microscopy showed that the implanted region consists of slightly misoriented [beta]-SiC crystals and textured crystalline aluminum carbide precipitates.

  4. Production and Precipitation Hardening of Beta-Type Ti-35Nb-10Cu Alloy Foam for Implant Applications

    Science.gov (United States)

    Mutlu, Ilven; Yeniyol, Sinem; Oktay, Enver

    2016-04-01

    In this study, beta-type Ti-35Nb-10Cu alloy foams were produced by powder metallurgy method for dental implant applications. 35% Nb was added to stabilize the beta-Ti phase with low Young's modulus. Cu addition enhanced sinterability and gave precipitation hardening capacity to the alloy. Sintered specimens were precipitation hardened in order to enhance the mechanical properties. Electrochemical corrosion behavior of the specimens was examined by electrochemical impedance spectroscopy in artificial saliva. Electrochemical impedance spectroscopy results indicated that the oxide film on the surface of foam is a bi-layer structure consisting of outer porous layer and inner barrier layer. Impedance values of barrier layer were higher than porous layer. Corrosion resistance of specimens decreased at high fluoride concentrations and at low pH of artificial saliva. Corrosion resistance of alloys was slightly decreased with aging. Mechanical properties, microstructure, and surface roughness of the specimens were also examined.

  5. Latest results of NEXT-DEMO, the prototype of the NEXT 100 double beta decay experiment

    CERN Document Server

    Serra, L; Martin-Albo, J; Sorel, M; Gomez-Cadenas, J J

    2014-01-01

    NEXT-DEMO is a 1:4.5 scale prototype of the NEXT100 detector, a high-pressure xenon gas TPC that will search for the neutrinoless double beta decay of $^{136}$Xe. X-ray energy depositions produced by the de-excitation of Xenon atoms after the interaction of gamma rays from radioactive sources have been used to characterize the response of the detector obtaining the spatial calibration needed for close-to-optimal energy resolution. Our result, 5.5% FWHM at 30 keV, extrapolates to 0.6% FWHM at the Q value of $^{136}$Xe. Additionally, alpha decays from radon have been used to measure several detection properties and parameters of xenon gas such as electron-ion recombination, electron drift velocity, diffusion and primary scintillation light yield. Alpha spectroscopy is also used to quantify the activity of radon inside the detector, a potential source of background for most double beta decay experiments.

  6. Remarkably stable inclusion complexes with heptakis-[6-deoxy-6-(2-aminoethylsulfanyl)]-beta-cyclodextrin.

    Science.gov (United States)

    Gómez-Biagi, Rodolfo F; Jagt, Richard B C; Nitz, Mark

    2008-12-21

    Complexes of heptakis-[6-deoxy-6-(2-aminoethylsulfanyl)]-beta-cyclodextrin (1) and a series of common cyclodextrin guests were studied by NMR, fluorescence spectroscopy, and ITC experiments. NMR conformational analysis shows that the thioethers of 1 are positioned over the hydrophobic cavity of the cyclodextrin, increasing potential hydrophobic interactions with guest molecules. The combination of the increased hydrophobic character, the electrostatic complementarity and a hypothesized conformational change in 1 lead to a complex with the dye 2,6-ANS (5) that is over 2000 times more stable than with the native beta-cyclodextrin. One of the most stable host-guest complexes between a cyclodextrin and a small molecule measured to date was revealed between 1 and lithocholic acid (4) with an association constant of 5.5 x 10(7) M(-1).

  7. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    International Nuclear Information System (INIS)

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  8. A new tool in peptide engineering: a photoswitchable stilbene-type beta-hairpin mimetic.

    Science.gov (United States)

    Erdélyi, Máté; Karlén, Anders; Gogoll, Adolf

    2005-12-23

    Peptide secondary structure mimetics are important tools in medicinal chemistry, as they provide analogues of endogenous peptides with new physicochemical and pharmacological properties. The development, synthesis, photochemical investigation, and conformational analysis of a stilbene-type beta-hairpin mimetic capable of light-triggered conformational changes have been achieved. In addition to standard spectroscopic techniques (nuclear Overhauser effects, amide temperature coefficients, circular dichroism spectroscopy), the applicability of self-diffusion measurements (longitudinal eddy current delay pulsed-field gradient spin echo (LED-PGSE) NMR technique) in conformational studies of oligopeptides is demonstrated. The title compound shows photoisomerization of the stilbene chromophore, resulting in a change in solution conformation between an unfolded structure and a folded beta-hairpin.

  9. Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

    Energy Technology Data Exchange (ETDEWEB)

    Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Ferreira, Glaucio B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica; Mota, Claudio J.A., E-mail: cmota@iq.ufrj.br [INCT Energia e Ambiente, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-01-15

    The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

  10. $\\beta$-decay study of neutron-rich Tl and Pb isotopes

    CERN Multimedia

    It is proposed to study the structure of neutron-rich nuclei beyond $^{208}$Pb. The one-proton hole $^{211-215}$Tl and the semi magic $^{213}$Pb will be produced and studied via nuclear and atomic spectroscopy searching for long-lived isomers and investigating the $\\beta$-delayed $\\gamma$- emission to build level schemes. Information on the single particle structure in $^{211-215}$Pb, especially the position of the g$_{9/2}$ and i$_{11/2}$ neutron orbitals, will be extracted along with lifetimes. The $\\beta$-decay will be complemented with the higher spin selectivity that can be obtained by resonant laser ionization to single-out the decay properties of long-living isomers in $^{211,213}$Tl and $^{213}$Pb.

  11. Detrimental effects of beta-blockers in COPD - A concern for nonselective beta-blockers

    NARCIS (Netherlands)

    van der Woude, HJ; Zaagsma, J; Postma, DS; Winter, TH; van Hulst, M; Aalbers, R

    2005-01-01

    Introduction: beta-Blockers are known to worsen FEV1 and airway hyperresponsiveness (AHR) in patients with asthma. Both characteristics determine the outcome of COPD, a disease with frequent cardiac comorbidity requiring beta-blocker treatment. Design: A double-blind, placebo-controlled, randomized,

  12. BETA SPECTRA. I. Negatrons spectra; ESPECTROS BETA. I. Espectros simples de negatrones

    Energy Technology Data Exchange (ETDEWEB)

    Grau Malonda, A.; Garcia-Torano, E.

    1978-07-01

    Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

  13. Mrp2 is essential for estradiol-17 beta(beta-D-glucuronide)-induced cholestasis in rats

    NARCIS (Netherlands)

    Huang, LY; Smit, JW; Meijer, DKF; Vore, M

    2000-01-01

    The present study evaluates the roles of the multidrug resistance-1 P-glycoprotein, Mdr1a/1b, the bile salt export pump (Bsep), and the multidrug resistance-associated protein-2 (Mrp2) in mediating cholestasis induced by estradiol-17 beta(beta-D-glucuronide) (E(2)17G). Administration of [H-3]E(2)17G

  14. Broadband Rotational Spectroscopy

    Science.gov (United States)

    Pate, Brooks

    2014-06-01

    The past decade has seen several major technology advances in electronics operating at microwave frequencies making it possible to develop a new generation of spectrometers for molecular rotational spectroscopy. High-speed digital electronics, both arbitrary waveform generators and digitizers, continue on a Moore's Law-like development cycle that started around 1993 with device bandwidth doubling about every 36 months. These enabling technologies were the key to designing chirped-pulse Fourier transform microwave (CP-FTMW) spectrometers which offer significant sensitivity enhancements for broadband spectrum acquisition in molecular rotational spectroscopy. A special feature of the chirped-pulse spectrometer design is that it is easily implemented at low frequency (below 8 GHz) where Balle-Flygare type spectrometers with Fabry-Perot cavity designs become technologically challenging due to the mirror size requirements. The capabilities of CP-FTMW spectrometers for studies of molecular structure will be illustrated by the collaborative research effort we have been a part of to determine the structures of water clusters - a project which has identified clusters up to the pentadecamer. A second technology trend that impacts molecular rotational spectroscopy is the development of high power, solid state sources in the mm-wave/THz regions. Results from the field of mm-wave chirped-pulse Fourier transform spectroscopy will be described with an emphasis on new problems in chemical dynamics and analytical chemistry that these methods can tackle. The third (and potentially most important) technological trend is the reduction of microwave components to chip level using monolithic microwave integrated circuits (MMIC) - a technology driven by an enormous mass market in communications. Some recent advances in rotational spectrometer designs that incorporate low-cost components will be highlighted. The challenge to the high-resolution spectroscopy community - as posed by Frank De

  15. Regulation of glycogen synthase kinase-3{beta} (GSK-3{beta}) after ionizing radiation; Regulation der Glykogen Synthase Kinase-3{beta} (GSK-3{beta}) nach ionisierender Strahlung

    Energy Technology Data Exchange (ETDEWEB)

    Boehme, K.A.

    2006-12-15

    Glycogen Synthase Kinase-3{beta} (GSK-3{beta}) phosphorylates the Mdm2 protein in the central domain. This phosphorylation is absolutely required for p53 degradation. Ionizing radiation inactivates GSK-3{beta} by phosphorylation at serine 9 and in consequence prevents Mdm2 mediated p53 degradation. During the work for my PhD I identified Akt/PKB as the kinase that phosphorylates GSK-3{beta} at serine 9 after ionizing radiation. Ionizing radiation leads to phosphorylation of Akt/PKB at threonine 308 and serine 473. The PI3 Kinase inhibitor LY294002 completely abolished Akt/PKB serine 473 phosphorylation and prevented the induction of GSK-3{beta} serine 9 phosphorylation after ionizing radiation. Interestingly, the most significant activation of Akt/PKB after ionizing radiation occurred in the nucleus while cytoplasmic Akt/PKB was only weakly activated after radiation. By using siRNA, I showed that Akt1/PKBa, but not Akt2/PKB{beta}, is required for phosphorylation of GSK- 3{beta} at serine 9 after ionizing radiation. Phosphorylation and activation of Akt/PKB after ionizing radiation depends on the DNA dependent protein kinase (DNA-PK), a member of the PI3 Kinase family, that is activated by free DNA ends. Both, in cells from SCID mice and after knockdown of the catalytic subunit of DNA-PK by siRNA in osteosarcoma cells, phosphorylation of Akt/PKB at serine 473 and of GSK-3{beta} at serine 9 was completely abolished. Consistent with the principle that phosphorylation of GSK-3 at serine 9 contributes to p53 stabilization after radiation, the accumulation of p53 in response to ionizing radiation was largely prevented by downregulation of DNA-PK. From these results I conclude, that ionizing radiation induces a signaling cascade that leads to Akt1/PKBa activation mediated by DNA-PK dependent phosphorylation of serine 473. After activation Akt1/PKBa phosphorylates and inhibits GSK-3{beta} in the nucleus. The resulting hypophosphorylated form of Mdm2 protein is no longer

  16. Inhibitory Effect of Curcumin-Cu(II) and Curcumin-Zn(II) Complexes on Amyloid-Beta Peptide Fibrillation

    OpenAIRE

    Rona Banerjee

    2014-01-01

    Mononuclear complexes of Curcumin with Cu(II) and Zn(II) have been synthesized and, characterized and their effects on the fibrillization and aggregation of amyloid-beta (Aβ) peptide have been studied. FTIR spectroscopy and atomic force microscopy (AFM) observations demonstrate that the complexes can inhibit the transition from less structured oligomers to β-sheet rich protofibrils which act as seeding factors for further fibrillization. The metal complexes also impart more improved inhibitor...

  17. Beta-Decay Study of ^{150}Er, ^{152}Yb, and ^{156}Yb: Candidates for a Monoenergetic Neutrino Beam Facility

    Energy Technology Data Exchange (ETDEWEB)

    Estevez Aguado, M. E. [CSIC-Universidad de Valencia; Algora, A. [CSIC-Universidad de Valencia; Rubio, B. [CSIC-Universidad de Valencia; Bernabeu, J. [CSIC-Universidad de Valencia; Nacher, E. [CSIC-Universidad de Valencia; Tain, J. L. [CSIC-Universidad de Valencia; Gadea, A. [CSIC-Universidad de Valencia; Agramunt, J. [CSIC-Universidad de Valencia; Burkard, K. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Hueller, W. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Doring, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kirchner, R. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mukha, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Plettner, C. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Roeckl, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Grawe, H. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Collatz, R. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Hellstrom, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Cano-Ott, D. [CIEMAT, Madrid; Karny, M. [University of Warsaw; Janas, Z. [University of Warsaw; Gierlik, M. [University of Warsaw; Plochocki, A. [University of Warsaw; Rykaczewski, Krzysztof Piotr [ORNL; Batist, L. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Moroz, F. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Wittman, V. [Petersburg Nuclear Physics Institute, Gatchina, Russia; Blazhev, A. [University of Cologne; Valiente, J. J. [INFN, Laboratori Nazionali di Legnaro, Italy; Espinoza, C. [CFPT-IST, Lisbon

    2011-01-01

    The beta decays of ^{150}Er, ^{152}Yb, and ^{156}Yb nuclei are investigated using the total absorption spectroscopy technique. These nuclei can be considered possible candidates for forming the beam of a monoenergetic neutrino beam facility based on the electron capture (EC) decay of radioactive nuclei. Our measurements confirm that for the cases studied, the EC decay proceeds mainly to a single state in the daughter nucleus.

  18. Selective binding of chiral molecules of cinchona alkaloid by beta- and gamma-cyclodextrins and organoselenium-bridged bis(beta-cyclodextrin)s.

    Science.gov (United States)

    Liu, Yu; Li, Li; Zhang, Heng-Yi; Fan, Zhi; Guan, Xu-Dong

    2003-02-01

    The inclusion complexation behavior of chiral members of cinchona alkaloid with beta- and gamma-cyclodextrins (1 and 2) and 6,6(')-trimethylenediseleno-bridged bis(beta-cyclodextrin) (3) was assessed by means of fluorescence and 2D-NMR spectroscopy. The spectrofluorometric titrations have been performed in aqueous buffer solution (pH 7.20) at 25.0 degrees C to determine the stability constants of the inclusion complexation of 1-3 with guest molecules (i.e., cinchonine, cinchonidine, quinine, and quinidine) in order to quantitatively investigate the molecular selective binding ability. The stability constants of the resulting complexes of 2 with guest molecules are larger than that of 1. As a result of cooperative binding, the stability constants of inclusion complexation of dimeric beta-cyclodextrin 3 with cinchonidine and cinchonine are higher than that of parent 1 by factor of 4.5 and 2.4, respectively. These results are discussed from the viewpoint of the size-fit and geometric complementary relationship between the host and guest.

  19. NMR spectroscopy reveals unexpected structural variation at the protein-protein interface in MHC class I molecules

    Energy Technology Data Exchange (ETDEWEB)

    Beerbaum, Monika; Ballaschk, Martin; Erdmann, Natalja [Leibniz-Institut fuer Molekulare Pharmakologie (FMP) (Germany); Schnick, Christina [Freie Universitaet Berlin, Institut fuer Immungenetik, Charite-Universitaetsmedizin Berlin (Germany); Diehl, Anne [Leibniz-Institut fuer Molekulare Pharmakologie (FMP) (Germany); Uchanska-Ziegler, Barbara; Ziegler, Andreas [Freie Universitaet Berlin, Institut fuer Immungenetik, Charite-Universitaetsmedizin Berlin (Germany); Schmieder, Peter, E-mail: schmieder@fmp-berlin.de [Leibniz-Institut fuer Molekulare Pharmakologie (FMP) (Germany)

    2013-10-15

    {beta}{sub 2}-Microglobulin ({beta}{sub 2}m) is a small, monomorphic protein non-covalently bound to the heavy chain (HC) in polymorphic major histocompatibility complex (MHC) class I molecules. Given the high evolutionary conservation of structural features of {beta}{sub 2}m in various MHC molecules as shown by X-ray crystallography, {beta}{sub 2}m is often considered as a mere scaffolding protein. Using nuclear magnetic resonance (NMR) spectroscopy, we investigate here whether {beta}{sub 2}m residues at the interface to the HC exhibit changes depending on HC polymorphisms and the peptides bound to the complex in solution. First we show that human {beta}{sub 2}m can effectively be produced in deuterated form using high-cell-density-fermentation and we employ the NMR resonance assignments obtained for triple-labeled {beta}{sub 2}m bound to the HLA-B*27:09 HC to examine the {beta}{sub 2}m-HC interface. We then proceed to compare the resonances of {beta}{sub 2}m in two minimally distinct subtypes, HLA-B*27:09 and HLA-B*27:05, that are differentially associated with the spondyloarthropathy Ankylosing Spondylitis. Each of these subtypes is complexed with four distinct peptides for which structural information is already available. We find that only the resonances at the {beta}{sub 2}m-HC interface show a variation of their chemical shifts between the different complexes. This indicates the existence of an unexpected plasticity that enables {beta}{sub 2}m to accommodate changes that depend on HC polymorphism as well as on the bound peptide through subtle structural variations of the protein-protein interface.

  20. International symposium on NMR spectroscopy

    International Nuclear Information System (INIS)

    The publication consists of 32 papers and presentations from the field of NMR spectroscopy applications submitted to the International Symposium on NMR Spectroscopy held at Smolenice between 29 Sep and 3 Oct, 1980. (B.S.)

  1. Substitution of isoleucine-31 by helical-breaking proline abolishes oxidative stress and neurotoxic properties of Alzheimer's amyloid beta-peptide.

    Science.gov (United States)

    Kanski, Jaroslaw; Aksenova, Marina; Schöneich, Christian; Butterfield, D Allan

    2002-06-01

    Alzheimer's disease (AD) brain is characterized by excess deposition of the 42-amino acid amyloid beta-peptide [A(beta)(1-42)]. AD brain is under intense oxidative stress, and we have previously suggested that A(beta)(1-42) was associated with this increased oxidative stress. In addition, we previously demonstrated that the single methionine residue of A(beta)(1-42), residue 35, was critical for the oxidative stress and neurotoxic properties of this peptide. Others have shown that the C-terminal region of A(beta)(1-42) is helical in aqueous micellar solutions, including that part of the protein containing Met35. Importantly, Cu(II)-binding induces alpha-helicity in A(beta) in aqueous solution. Invoking the i + 4 rule of helices, we hypothesized that the carbonyl oxygen of Ile31 would interact with the S atom of Met35 to change the electronic environment of the sulfur such that molecular oxygen could lead to the production of a sulfuramyl free radical on Met35. If this hypothesis is correct, a prediction would be that breaking the helical interaction of Ile31 and Met35 would abrogate the oxidative stress and neurotoxic properties of A(beta)(1-42). Accordingly, we investigated A(beta)(1-42) in which the Ile31 residue was replaced with the helix-breaking amino acid, proline. The alpha-helical environment around Met35 was completely abolished as indicated by circular dichroism (CD)-spectroscopy. As a consequence, the aggregation, oxidative stress, Cu(II) reduction, and neurotoxic properties of A(beta)(1-42)I31P were completely altered compared to native A(beta)(1-42). The results presented here are consistent with the notion that interaction of Ile31 with Met35 may play an important role in the oxidative processes of Met35 contributing to the toxicity of the peptide.

  2. Single-electron detection and spectroscopy via relativistic cyclotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Asner, David M.; Bradley, Rich; De Viveiros Souza Filho, Luiz A.; Doe, Peter J.; Fernandes, Justin L.; Fertl, M.; Finn, Erin C.; Formaggio, Joseph; Furse, Daniel L.; Jones, Anthony M.; Kofron, Jared N.; LaRoque, Benjamin; Leber, Michelle; MCBride, Lisa; Miller, M. L.; Mohanmurthy, Prajwal T.; Monreal, Ben; Oblath, Noah S.; Robertson, R. G. H.; Rosenberg, Leslie; Rybka, Gray; Rysewyk, Devyn M.; Sternberg, Michael G.; Tedeschi, Jonathan R.; Thummler, Thomas; VanDevender, Brent A.; Woods, N. L.

    2015-04-01

    It has been understood since 1897 that accelerating charges should emit electromagnetic radiation. Cyclotron radiation, the particular form of radiation emitted by an electron orbiting in a magnetic field, was first derived in 1904. Despite the simplicity of this concept, and the enormous utility of electron spectroscopy in nuclear and particle physics, single-electron cyclotron radiation has never been observed directly. Here we demonstrate single-electron detection in a novel radiofrequency spectrometer. We observe the cyclotron radiation emitted by individual electrons that are produced with mildly-relativistic energies by a gaseous radioactive source and are magnetically trapped. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta electron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay endpoint, and this work is a proof-of-concept for future neutrino mass experiments using this technique.

  3. Neutrinoless double beta decay from lattice QCD

    CERN Document Server

    Nicholson, Amy; Chang, Chia Cheng; Clark, M A; Joo, Balint; Kurth, Thorsten; Rinaldi, Enrico; Tiburzi, Brian; Vranas, Pavlos; Walker-Loud, Andre

    2016-01-01

    While the discovery of non-zero neutrino masses is one of the most important accomplishments by physicists in the past century, it is still unknown how and in what form these masses arise. Lepton number-violating neutrinoless double beta decay is a natural consequence of Majorana neutrinos and many BSM theories, and many experimental efforts are involved in the search for these processes. Understanding how neutrinoless double beta decay would manifest in nuclear environments is key for understanding any observed signals. In these proceedings we present an overview of a set of one- and two-body matrix elements relevant for experimental searches for neutrinoless double beta decay, describe the role of lattice QCD calculations, and present preliminary lattice QCD results.

  4. Estimating beta-mixing coefficients via histograms

    CERN Document Server

    McDonald, Daniel J; Schervish, Mark

    2011-01-01

    The literature on statistical learning for time series often assumes asymptotic independence or "mixing" of data sources. Beta-mixing has long been important in establishing the central limit theorem and invariance principle for stochastic processes; recent work has identified it as crucial to extending results from empirical processes and statistical learning theory to dependent data, with quantitative risk bounds involving the actual beta coefficients. There is, however, presently no way to actually estimate those coefficients from data; while general functional forms are known for some common classes of processes (Markov processes, ARMA models, etc.), specific coefficients are generally beyond calculation. We present an l1-risk consistent estimator for the beta-mixing coefficients, based on a single stationary sample path. Since mixing coefficients involve infinite-order dependence, we use an order-d Markov approximation. We prove high-probability concentration results for the Markov approximation and show...

  5. Tevatron B0 low beta tuning report

    International Nuclear Information System (INIS)

    A detailed study of the low beta insertion for the B0 experimental area has been carried out and is described below. This insertion is similar to the Type C low beta previously report, anti p Note 169, although some changes have been made to the quadrupole lengths and positions. This insertion is designated Type E. The purpose of the study was to see if it is possible to turn the insertion on in a smooth and continuous manner and tune the insertion to a value of β* of less than one meter while maintaining the overall tune of the j Tevatron to a constant value. This was found to be possible. An examination of chromaticity corrections for the Tevatron with the low beta insertion on in various configurations was also undertaken

  6. Antihydrogen Experiment Gravity Interferometry Spectroscopy

    CERN Multimedia

    Gerber, S; Tietje, I C; Allkofer, Y R; Trezzi, D; Dassa, L; Rienacker, B; Khalidova, O; Ferrari, G; Krasnicky, D; Perini, D; Cerchiari, G; Belov, A; Boscolo, I; Sacerdoti, M G; Ferragut, R O; Nedelec, P; Testera, G; Hinterberger, A; Al-qaradawi, I; Malbrunot, C L S; Brusa, R S; Prelz, F; Manuzio, G; Riccardi, C; Fontana, A; Genova, P; Haider, S; Haug, F; Merkt, F; Turbabin, A; Castelli, F; Doser, M; Penasa, L; Gninenko, S; Cataneo, F; Zenoni, A; Cabaret, L; Comparat, D P; Zmeskal, J; Scampoli, P; Dudarev, A; Kellerbauer, A G; Lagomarsino, V E; Mariazzi, S; Fesel, J V; Nesteruk, K P; Eisel, W T; Carraro, C; Zavatarelli, S M

    The AEGIS experiment (Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy) has the aim of carrying out the first measurement of the gravitational interaction of antimatter to a precision of 1%, by applying techniques from atomic physics, laser spectroscopy and interferometry to a beam of antihydrogen atoms. A further goal of the experiment is to carry out spectroscopy of the antihydrogen atoms in flight.

  7. BETASCAN: probable beta-amyloids identified by pairwise probabilistic analysis.

    Directory of Open Access Journals (Sweden)

    Allen W Bryan

    2009-03-01

    Full Text Available Amyloids and prion proteins are clinically and biologically important beta-structures, whose supersecondary structures are difficult to determine by standard experimental or computational means. In addition, significant conformational heterogeneity is known or suspected to exist in many amyloid fibrils. Recent work has indicated the utility of pairwise probabilistic statistics in beta-structure prediction. We develop here a new strategy for beta-structure prediction, emphasizing the determination of beta-strands and pairs of beta-strands as fundamental units of beta-structure. Our program, BETASCAN, calculates likelihood scores for potential beta-strands and strand-pairs based on correlations observed in parallel beta-sheets. The program then determines the strands and pairs with the greatest local likelihood for all of the sequence's potential beta-structures. BETASCAN suggests multiple alternate folding patterns and assigns relative a priori probabilities based solely on amino acid sequence, probability tables, and pre-chosen parameters. The algorithm compares favorably with the results of previous algorithms (BETAPRO, PASTA, SALSA, TANGO, and Zyggregator in beta-structure prediction and amyloid propensity prediction. Accurate prediction is demonstrated for experimentally determined amyloid beta-structures, for a set of known beta-aggregates, and for the parallel beta-strands of beta-helices, amyloid-like globular proteins. BETASCAN is able both to detect beta-strands with higher sensitivity and to detect the edges of beta-strands in a richly beta-like sequence. For two proteins (Abeta and Het-s, there exist multiple sets of experimental data implying contradictory structures; BETASCAN is able to detect each competing structure as a potential structure variant. The ability to correlate multiple alternate beta-structures to experiment opens the possibility of computational investigation of prion strains and structural heterogeneity of amyloid

  8. Study of the deuteron emission in the $\\beta$-decay of $^{6}$He

    CERN Multimedia

    Karny, M; Tengblad, O; Riisager, K; Perkowski, J; Garcia borge, M J; Raabe, R; Kowalska, M; Fynbo, H O U; Perea martinez, A; Ter-akopian, G; Huyse, M L

    The main goal of the present proposal is to measure the continuous spectrum of deuterons emitted in the $\\beta$-decay of $^{6}$He. In particular, we want to focus on the low energy part of the spectrum, below 400 keV, which could not be accessed by all previous experiments. For the decay spectroscopy the Warsaw Optical Time Projection Chamber (OTPC) will be used. The bunches of $^{6}$He ions produced by REX-ISOLDE facility will be implanted into the active volume of the OTPC, where the rare events of deuteron emission will be recorded, practically background free.

  9. High Resolution Laboratory Spectroscopy

    CERN Document Server

    Brünken, Sandra

    2016-01-01

    In this short review we will highlight some of the recent advancements in the field of high-resolution laboratory spectroscopy that meet the needs dictated by the advent of highly sensitive and broadband telescopes like ALMA and SOFIA. Among these is the development of broadband techniques for the study of complex organic molecules, like fast scanning conventional absorption spectroscopy based on multiplier chains, chirped pulse instrumentation, or the use of synchrotron facilities. Of similar importance is the extension of the accessible frequency range to THz frequencies, where many light hydrides have their ground state rotational transitions. Another key experimental challenge is the production of sufficiently high number densities of refractory and transient species in the laboratory, where discharges have proven to be efficient sources that can also be coupled to molecular jets. For ionic molecular species sensitive action spectroscopic schemes have recently been developed to overcome some of the limita...

  10. Precision Muonium Spectroscopy

    CERN Document Server

    Jungmann, Klaus P

    2016-01-01

    The muonium atom is the purely leptonic bound state of a positive muon and an electron. It has a lifetime of 2.2 $\\mu$s. The absence of any known internal structure provides for precision experiments to test fundamental physics theories and to determine accurate values of fundamental constants. In particular groun dstate hyperfine structure transitions can be measured by microwave spectroscopy to deliver the muon magnetic moment. The frequency of the 1s-2s transition in the hydrogen-like atom can be determined with laser spectroscopy to obtain the muon mass. With such measurements fundamental physical interactions, in particular Quantum Electrodynamics, can also be tested at highest precision. The results are important input parameters for experiments on the muon magnetic anomaly. The simplicity of the atom enables further precise experiments, such as a search for muonium-antimuonium conversion for testing charged lepton number conservation and searches for possible antigravity of muons and dark matter.

  11. Femtosecond laser spectroscopy

    CERN Document Server

    Hannaford, Peter

    2005-01-01

    As concepts and methodologies have evolved over the past two decades, the realm of ultrafast science has become vast and exciting and has impacted many areas of chemistry, biology and physics, and other fields such as materials science, electrical engineering, and optical communication. The field has recently exploded with the announcement of a series of remarkable new developments and advances. This volume surveys this recent growth in eleven chapters written by leading international researchers in the field. It includes sections on femtosecond optical frequency combs, soft x-ray femtosecond laser sources, and attosecond laser sources. In addition, the contributors address real-time spectroscopy of molecular vibrations with sub-5-fs pulses and multidimensional femtosecond coherent spectroscopies for studying molecular and electron dynamics. Novel methods for measuring and characterizing ultrashort laser pulses and ultrashort pulses of light are also described. The topics covered are revolutionizing the field...

  12. Visible spectroscopy on ASDEX

    International Nuclear Information System (INIS)

    In this report visible spectroscopy and impurity investigations on ASDEX are reviewed and several sets of visible spectra are presented. As a basis for identification of metallic impurity lines during plasma discharges spectra from a stainless steel - Cu arc have been recorded. In a next step a spectrum overview of ASDEX discharges is shown which reveals the dominating role of lines from light impurities like carbon and oxygen throughout the UV and visible range (2000 A ≤ λ ≤ 8000 A). Metallic impurity lines of neutrals or single ionized atoms are observed near localized surfaces. The dramatic effect of impurity reduction by boronization of the vessel walls is demonstrated in a few examples. In extension to some ivesti-gations already published, further diagnostic applications of visible spectroscopy are presented. Finally, the hardware and software system used on ASDEX are described in detail. (orig.)

  13. Precision Muonium Spectroscopy

    Science.gov (United States)

    Jungmann, Klaus P.

    2016-09-01

    The muonium atom is the purely leptonic bound state of a positive muon and an electron. It has a lifetime of 2.2 µs. The absence of any known internal structure provides for precision experiments to test fundamental physics theories and to determine accurate values of fundamental constants. In particular ground state hyperfine structure transitions can be measured by microwave spectroscopy to deliver the muon magnetic moment. The frequency of the 1s-2s transition in the hydrogen-like atom can be determined with laser spectroscopy to obtain the muon mass. With such measurements fundamental physical interactions, in particular quantum electrodynamics, can also be tested at highest precision. The results are important input parameters for experiments on the muon magnetic anomaly. The simplicity of the atom enables further precise experiments, such as a search for muonium-antimuonium conversion for testing charged lepton number conservation and searches for possible antigravity of muons and dark matter.

  14. Spectroscopy of gravity

    Energy Technology Data Exchange (ETDEWEB)

    Abele, Hartmut; Bittner, Thomas; Cronenberg, Gunther; Filter, Hanno; Jenke, Tobias; Lemmel, Hartmut; Thalhammer, Martin [Atominstitut TU Wien, Wien (Austria); Geltenbort, Peter [Institut Laue-Langevin, Grenoble (France)

    2012-07-01

    This talk is about a test of the Newtons Inverse Square Law of Gravity at micron distances by quantum interference with ultra-cold neutrons deep into the theoretically interesting regime. The method is based on a new resonance spectroscopy technique related to Rabi spectroscopy, but it has been adapted to gravitationally bound quantum systems. By coupling such a quantum system to mechanical vibrations, we observe resonant transitions, devoid of electromagnetic interaction. As Newtonian gravity and hypothetical Fifth Forces evolve with different phase information, the experiment has the potential to test the equivalence principle and Newtons gravity law at the micron scale. This experiment can therefore test speculations on large extra dimensions of sub-millimetre size of space-time or the origin of the cosmological constant in the universe, where effects are predicted in the interesting range of this experiment and might give a signal in an improved setup.

  15. beta2-Agonists at the Olympic Games.

    Science.gov (United States)

    Fitch, Kenneth D

    2006-01-01

    The different approaches that the International Olympic Committee (IOC) had adopted to beta2-agonists and the implications for athletes are reviewed by a former Olympic team physician who later became a member of the Medical Commission of the IOC (IOC-MC). Steadily increasing knowledge of the effects of inhaled beta2-agonists on health, is concerned with the fact that oral beta2-agonists may be anabolic, and rapid increased use of inhaled beta2-agonists by elite athletes has contributed to the changes to the IOC rules. Since 2001, the necessity for athletes to meet IOC criteria (i.e., that they have asthma and/or exercise-induced asthma [EIA]) has resulted in improved management of athletes. The prevalence of beta2-agonist use by athletes mirrors the known prevalence of asthma symptoms in each country, although athletes in endurance events have the highest prevalence. The age-of-onset of asthma/EIA in elite winter athletes may be atypical. Of the 193 athletes at the 2006 Winter Olympics who met th IOC's criteria, only 32.1% had childhood asthma and 48.7% of athletes reported onset at age 20 yr or older. These findings lead to speculation that years of intense endurance training may be a causative factor in bronchial hyperreactivity. The distinction between oral (prohibited in sports) and inhaled salbutamol is possible, but athletes must be warned that excessive use of inhaled salbutamol can lead to urinary concentrations similar to those observed after oral administration. This article provides justification that athletes should provide evidence of asthma or EIA before being permitted to use inhaled beta2-agonists. PMID:17085798

  16. Nonequilibrium spin noise spectroscopy

    OpenAIRE

    Li, Fuxiang; Pershin, Yuriy V.; Slipko, Valeriy A.; Sinitsyn, Nikolai A.

    2013-01-01

    Spin Noise Spectroscopy (SNS) is an experimental approach to obtain correlators of mesoscopic spin fluctuations in time by purely optical means. We explore the information that this technique can provide when it is applied to a weakly non-equilibrium regime when an electric current is driven through a sample by an electric field. We find that the noise power spectrum of conducting electrons experiences a shift, which is proportional to the strength of the spin-orbit coupling for electrons mov...

  17. Optical imaging and spectroscopy

    CERN Document Server

    Brady, David J

    2009-01-01

    An essential reference for optical sensor system design This is the first text to present an integrated view of the optical and mathematical analysis tools necessary to understand computational optical system design. It presents the foundations of computational optical sensor design with a focus entirely on digital imaging and spectroscopy. It systematically covers: Coded aperture and tomographic imaging Sampling and transformations in optical systems, including wavelets and generalized sampling techniques essential to digital system analysis Geometric, wave, and statis

  18. 2008 Vibrational Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Philip J. Reid

    2009-09-21

    The conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and interfaces. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of systems.

  19. Beta/gamma test problems for ITS

    International Nuclear Information System (INIS)

    The Integrated Tiger Series of Coupled Electron/Photon Monte Carlo Transport Codes (ITS 3.0, PC Version) was used at Oak Ridge National Laboratory (ORNL) to compare with and extend the experimental findings of the beta/gamma response of selected health physics instruments. In order to assure that ITS gives correct results, several beta/gamma problems have been tested. ITS was used to simulate these problems numerically, and results for each were compared to the problem's experimental or analytical results. ITS successfully predicted the experimental or analytical results of all tested problems within the statistical uncertainty inherent in the Monte Carlo method

  20. Helicity and nuclear $\\beta$ decay correlations

    CERN Document Server

    Hong, Ran; García, Alejandro

    2016-01-01

    We present simple derivations of nuclear $\\beta$-decay correlations with an emphasis on the special role of helicity. This provides a good opportunity to teach students about helicity and chirality in particle physics through exercises using simple aspects of quantum mechanics. In addition, this paper serves as an introduction to nuclear $\\beta$-decay correlations from both a theoretical and experimental vantage. This article can be used to introduce students to ongoing experiments searching for hints of new physics in the low-energy precision frontier.

  1. Volume Effects in Discrete beta functions

    CERN Document Server

    Liu, Yuzhi; Zou, Haiyuan

    2011-01-01

    We calculate discrete beta functions corresponding to the two-lattice matching for the 2D O(N) models and Dyson's hierarchical model. We describe and explain finite-size effects such as the appearance of a nontrivial infrared fixed point that goes to infinity at infinite volume or the merging of an infrared and an ultraviolet fixed point. We present extensions of the RG flows to the complex coupling plane. We discuss the possibility of constructing a continuous beta function from the discrete one by using functional conjugation methods. We briefly discuss the relevance of these findings for the search of nontrivial fixed points in multiflavor lattice gauge theory models.

  2. Population screening for beta-thalassaemia.

    Science.gov (United States)

    Flatz, S D; Flatz, G

    1980-09-01

    The graphic recording of time to 50% haemolysis in a glycerine-saline solution is a simple, reproducible method of determining erythrocyte osmotic fragility. Studies on a normal population yielded an upper limit of normal of 90 s. In 250 healthy males from Northern Thailand all 19 with beta-thalassaemia minor had abnormal osmotic indices, and the value of the test was confirmed in beta-thalassaemia heterozygotes in Europe. Of 23 patients with iron deficiency 18 had abnormal osmotic indices. However, this is not thought likely to be a significant source of false positives in the screening of populations at risk of haemoglobinopathies but in whom iron deficiency is rare.

  3. Survey instrument response to beta radiations

    International Nuclear Information System (INIS)

    Available survey instruments do not have the beta measurement characteristics needed for accurate dose rate assessments. Such instruments have severe angular and energy dependence. In addition, beta measurements often require corrections for the source geometry response of the detector to permit accurate assessments. Studies were performed to characterize present instruments and to determine optimum characteristics for a field instrument. Results of the studies were used to specify and procure an instrument with improved characteristics. The purpose of this paper is to describe the results of the studies and the design of the instrument

  4. Survey instrument response to beta radiations

    International Nuclear Information System (INIS)

    Available survey instruments do not have the beta measurement characteristics needed for accurate dose rate assessments. Such instruments have severe angular and energy dependence. In addition, beta measurements often require corrections for the source geometry response of the detector to permit accurate assessments. Studies were performed to characterize present instruments and to determine optimum characteristics for a field instrument. Results of the studies were used to specify and procure an instrument with improved characteristics. The purpose of this paper is to describe the results of the studies and the design of the instrument. 6 refs., 6 figs., 4 tabs

  5. Why search for double beta decay?

    International Nuclear Information System (INIS)

    Searching for neutrinoless double beta decay is the only known practical method for trying to determine whether neutrinos are their own antiparticles. The theoretical motivation for supposing that they may indeed be their own antiparticles is described. The reason that it is so difficult to ascertain experimentally whether they are or are not is explained, as is the special sensitivity of neutrinoless double beta decay. The potential implications of the observation of this reaction for neutrino mass and for the physics of neutrinos is discussed

  6. Supermultiplet of $\\beta-$deformations from twistors

    CERN Document Server

    Milián, Segundo P

    2016-01-01

    We consider the supermultiplet of linearized beta-deformation of $\\mathcal{N}=4$ Super Yang-Mills(SYM). It was previously studied on the gravitational side. We study the supermultiplet of beta-deformations on the field theory side and we compare two finite-dimensional representations of $psl(4|4,\\bf{R})$ algebra. We show that they are related by an intertwining operator. We develop a twistor-based approach which could be useful for studying other finite-dimensional and nonunitary representations in AdS/CFT correspondence.

  7. Layman friendly spectroscopy

    Science.gov (United States)

    Sentic, Stipo; Sessions, Sharon

    Affordable consumer grade spectroscopes (e.g. SCiO, Qualcomm Tricorder XPRIZE) are becoming more available to the general public. We introduce the concepts of spectroscopy to the public and K12 students and motivate them to delve deeper into spectroscopy in a dramatic participatory presentation and play. We use diffraction gratings, lasers, and light sources of different spectral properties to provide a direct experience of spectroscopy techniques. Finally, we invite the audience to build their own spectroscope--utilizing the APS SpectraSnapp cell phone application--and study light sources surrounding them in everyday life. We recontextualize the stigma that science is hard (e.g. ``Math, Science Popular Until Students Realize They're Hard,'' The Wall Street Journal) by presenting the material in such a way that it demonstrates the scientific method, and aiming to make failure an impersonal scientific tool--rather than a measure of one's ability, which is often a reason for shying away from science. We will present lessons we have learned in doing our outreach to audiences of different ages. This work is funded by the APS Outreach Grant ``Captain, we have matter matters!'' We thank New Mexico Tech Physics Department and Physics Club for help and technical equipment.

  8. Biomolecular EPR spectroscopy

    CERN Document Server

    Hagen, Wilfred Raymond

    2008-01-01

    Comprehensive, Up-to-Date Coverage of Spectroscopy Theory and its Applications to Biological SystemsAlthough a multitude of books have been published about spectroscopy, most of them only occasionally refer to biological systems and the specific problems of biomolecular EPR (bioEPR). Biomolecular EPR Spectroscopy provides a practical introduction to bioEPR and demonstrates how this remarkable tool allows researchers to delve into the structural, functional, and analytical analysis of paramagnetic molecules found in the biochemistry of all species on the planet. A Must-Have Reference in an Intrinsically Multidisciplinary FieldThis authoritative reference seamlessly covers all important bioEPR applications, including low-spin and high-spin metalloproteins, spin traps and spin lables, interaction between active sites, and redox systems. It is loaded with practical tricks as well as do's and don'ts that are based on the author's 30 years of experience in the field. The book also comes with an unprecedented set of...

  9. NATURAL CYCLOPENTANOID CYANOHYDRIN GLYCOSIDES .13. STRUCTURE DETERMINATION OF NATURAL EPOXYCYCLOPENTANES BY X-RAY CRYSTALLOGRAPHY AND NMR-SPECTROSCOPY

    DEFF Research Database (Denmark)

    Olafsdottir, E. S.; Sorensen, A. M.; Cornett, Claus;

    1991-01-01

    nonannellated cyclopentane derivatives. The new glucosides were shown, by NMR spectroscopy (including NOE measurements), X-ray crystallography, and enzymatic hydrolysis to the corresponding cyanohydrins, to be (1R,2R,3R,4R)- and (1S,2S,3S,4S)-1-(beta-D-glucopyranosyloxy)-2,3-epoxy-4-hydroxycyclopenta ne-1...

  10. Symmetry violations in nuclear and neutron $\\beta$ decay

    CERN Document Server

    Vos, K K; Timmermans, R G E

    2015-01-01

    The role of $\\beta$ decay as a low-energy probe of physics beyond the Standard Model is reviewed. Traditional searches for deviations from the Standard Model structure of the weak interaction in $\\beta$ decay are discussed in the light of constraints from the LHC and the neutrino mass. Limits on the violation of time-reversal symmetry in $\\beta$ decay are compared to the strong constraints from electric dipole moments. Novel searches for Lorentz symmetry breaking in the weak interaction in $\\beta$ decay are also included, where we discuss the unique sensitivity of $\\beta$ decay to test Lorentz invariance. We end with a roadmap for future $\\beta$-decay experiments.

  11. Transforming growth factor-beta (TGF-beta) and programmed cell death in the vertebrate retina.

    Science.gov (United States)

    Duenker, Nicole

    2005-01-01

    Programmed cell death (PCD) is a precisely regulated phenomenon essential for the homeostasis of multicellular organisms. Developmental systems, particularly the nervous system, have provided key observations supporting the physiological role of PCD. We have recently shown that transforming growth factor-beta (TGF-beta) plays an important role in mediating ontogenetic PCD in the nervous system. As part of the central nervous system the developing retina serves as an ideal model system for investigating apoptotic processes during neurogenesis in vivo as it is easily accessible experimentally and less complex due to its limited number of different neurons. This review summarizes data indicating a pivotal role of TGF-beta in mediating PCD in the vertebrate retina. The following topics are discussed: expression of TGF-beta isoforms and receptors in the vertebrate retina, the TGF-beta signaling pathway, functions and molecular mechanisms of PCD in the nervous system, TGF-beta-mediated retinal apoptosis in vitro and in vivo, and interactions of TGF-beta with other pro- and anti-apoptotic factors.

  12. Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge

    CERN Document Server

    Brown, B A; Horoi, M

    2015-01-01

    The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...

  13. Human liver alcohol dehydrogenase. 1. The primary structure of the beta 1 beta 1 isoenzyme.

    Science.gov (United States)

    Hempel, J; Bühler, R; Kaiser, R; Holmquist, B; de Zalenski, C; von Wartburg, J P; Vallee, B; Jörnvall, H

    1984-12-17

    Determination of the amino acid sequence of the beta 1 subunit from the class I (pyrazole-sensitive) human liver alcohol dehydrogenase isoenzyme beta 1 beta 1 revealed a 373-residue structure differing at 48 positions (including a gap) from that of the subunit of the well studied horse liver alcohol dehydrogenase EE isoenzyme. The structure deduced is compatible with known differences in composition, ultraviolet absorbance, electrophoretic mobility and catalytic properties between the horse and human enzymes. All zinc-liganding residues of the horse E subunit are strictly conserved in the human beta 1 subunit, despite an earlier report of a mutation involving Cys-46. This residue therefore remains conserved in all known alcohol dehydrogenase structures. However, the total cysteine content of the beta 1 structure is raised from 14 in the subunit of the horse enzyme to 15 by a Tyr----Cys exchange. Most exchanges are on the surface of the molecule and of a well conserved nature. Substitutions close to the catalytic centre are of interest to explain the altered substrate specificity and different catalytic activity of the beta 1 homodimer. Functionally, a Ser----Thr exchange at position 48 appears to be of special importance, since Thr-48 in beta 1 instead of Ser-48 in the horse enzyme can restrict available space. Four other substitutions also line the active-site pocket, and appear to constitute partly compensated exchanges. PMID:6391920

  14. Earle K. Plyler Prize for Molecular Spectroscopy and Dynamics Lecture: 2D IR Spectroscopy of Peptide Conformation

    Science.gov (United States)

    Tokmakoff, Andrei

    2012-02-01

    Descriptions of protein and peptide conformation are colored by the methods we use to study them. Protein x-ray and NMR structures often lead to impressions of rigid or well-defined conformations, even though these are dynamic molecules. The conformational fluctuations and disorder of proteins and peptides is more difficult to quantify. This presentation will describe an approach toward characterizing and quantifying structural heterogeneity and disorder in peptides using 2D IR spectroscopy. Using amide I vibrational spectroscopy, isotope labeling strategies, and computational modeling based on molecular dynamics simulations and Markov state models allows us to characterize distinct peptide conformers and conformational variation. The examples illustrated include the beta-hairpin tripzip2 and elastin-like peptides.

  15. Spectroscopic study of turbulent heating in the high beta tokamak - Torus II

    International Nuclear Information System (INIS)

    Visible spectroscopy, involving line profile and line intensity measurements, was used to study the turbulent heating of the rectangular cross-section high-beta tokamak Torus II. The spectroscopy was done in the visible wave-length region using a six channel polychrometer having 0.2 A resolution, which is capable of radial scans of the plasma. The plasma, obtained by ionizing helium, is heated by poloidal skin currents, induced by a rapid (tau/sub R/ approx. = 1.7 μsec) change of the toroidal magnetic field either parallel or anti-parallel to the initial toroidal bias magnetic field, which converts a cold toroidal Z-pinch plasma into a hot tokamak plasma

  16. Spectroscopic study of turbulent heating in the high beta tokamak - Torus II

    Energy Technology Data Exchange (ETDEWEB)

    Georgiou, G.E.

    1979-01-01

    Visible spectroscopy, involving line profile and line intensity measurements, was used to study the turbulent heating of the rectangular cross-section high-beta tokamak Torus II. The spectroscopy was done in the visible wave-length region using a six channel polychrometer having 0.2 A resolution, which is capable of radial scans of the plasma. The plasma, obtained by ionizing helium, is heated by poloidal skin currents, induced by a rapid (tau/sub R/ approx. = 1.7 ..mu..sec) change of the toroidal magnetic field either parallel or anti-parallel to the initial toroidal bias magnetic field, which converts a cold toroidal Z-pinch plasma into a hot tokamak plasma.

  17. Topical beta-Blockers and Mortality

    NARCIS (Netherlands)

    Muskens, Rogier P. H. M.; Wolfs, Roger C. W.; Wittenian, Jacqueline C. M.; Hofman, Albert; de Jong, Paulus T. V. M.; Stricker, Bruno H. C.; Jansonius, Nomdo M.

    2008-01-01

    Purpose: To study the associations between long-term and short-term use of topical beta-blockers and mortality. Design: Prospective population-based cohort study. Participants: To examine long-term effects, 3842 participants aged 55 years and older were recruited. To examine short-term effects, 484

  18. Semiconductor detectors and double beta decay

    International Nuclear Information System (INIS)

    The underlying theory of double beta decay is discussed as well as some experimental observations. A class of second generation 76Ge detector experiments is then discussed. The design and physics considerations involved in the system used by LBL are explained, particularly the means of rejecting background activity. 24 references, 18 figures, 3 tables

  19. Herwig++ 2.0beta Release Note

    OpenAIRE

    Gieseke, Stefan; Grellscheid, D.; Ribon, Alberto; Richardson, P.; Seymour, Michael H.; Stephens, Phil; Webber, Bryan R

    2006-01-01

    A new release of the Monte Carlo program Herwig++ (version 2.0beta) is now available. The main new feature is the extension of the program to include simple hadron-hadron processes including the initial-state parton shower.

  20. Average beta measurement in EXTRAP T1

    International Nuclear Information System (INIS)

    Beginning with the ideal MHD pressure balance equation, an expression for the average poloidal beta, ΒΘ, is derived. A method for unobtrusively measuring the quantities used to evaluate ΒΘ in Extrap T1 is described. The results if a series of measurements yielding ΒΘ as a function of externally applied toroidal field are presented. (author)

  1. Characterization of a Commercial Silicon Beta Cell

    Energy Technology Data Exchange (ETDEWEB)

    Foxe, Michael P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hayes, James C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mayer, Michael F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); McIntyre, Justin I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Sivels, Ciara B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Suarez, Rey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-31

    Silicon detectors are of interest for the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) due to their enhanced energy resolution compared to plastic scintillators beta cells. Previous work developing a figure-of-merit (FOM) for comparison of beta cells suggests that the minimum detectable activity (MDA) could be reduced by a factor of two to three with the use of silicon detectors. Silicon beta cells have been developed by CEA (France) and Lares Ltd. (Russia), with the PIPSBox developed by CEA being commercially available from Canberra for approximately $35k, but there is still uncertainty about the reproducibility of the capabilities in the field. PNNL is developing a high-resolution beta-gamma detector system in the shallow underground laboratory, which will utilize and characterize the operation of the PIPSBox detector. Throughout this report, we examine the capabilities of the PIPSBox as developed by CEA. The lessons learned through the testing and use of the PIPSBox will allow PNNL to strategically develop a silicon detector optimized to better suit the communities needs in the future.

  2. Multiple nerve palsies in beta thalassaemia major.

    OpenAIRE

    Lamabadusuriya, S. P.

    1989-01-01

    A patient with beta thalassaemia major is described who developed a lower motor neurone facial nerve palsy on the left side, together with a phrenic nerve palsy on the same side, during the course of the illness. This complication has not been reported before in haemoglobinopathies.

  3. Association behavior of native beta-lactoglobulin

    DEFF Research Database (Denmark)

    Verheul, M.; Pedersen, J.S.; Roefs, S.P.F.M.;

    1999-01-01

    The association behavior of beta-lactoglobulin has been studied by small-angle neutron scattering as a function of protein concentration, temperature, pH, and NaCl concentration of the solution. By indirect Fourier transformation of the spectra, pair-distance distribution functions for the variou...

  4. Sources of beta cells inside the pancreas.

    Science.gov (United States)

    De Groef, Sofie; Staels, Willem; Van Gassen, Naomi; Lemper, Marie; Yuchi, Yixing; Sojoodi, Mozhdeh; Bussche, Leen; Heremans, Yves; Leuckx, Gunter; De Leu, Nico; Van de Casteele, Mark; Baeyens, Luc; Heimberg, Harry

    2016-09-01

    The generation of beta(-like) cells to compensate for their absolute or relative shortage in type 1 and type 2 diabetes is an obvious therapeutic strategy. Patients first received grafts of donor islet cells over 25 years ago, but this procedure has not become routine in clinical practice because of a donor cell shortage and (auto)immune problems. Transplantation of differentiated embryonic and induced pluripotent stem cells may overcome some but not all the current limitations. Reprogramming exocrine cells towards functional beta(-like) cells would offer an alternative abundant and autologous source of beta(-like) cells. This review focuses on work by our research group towards achieving such a source of cells. It summarises a presentation given at the 'Can we make a better beta cell?' symposium at the 2015 annual meeting of the EASD. It is accompanied by two other reviews on topics from this symposium (by Amin Ardestani and Kathrin Maedler, DOI: 10.1007/s00125-016-3892-9 , and by Heiko Lickert and colleagues, DOI: 10.1007/s00125-016-3949-9 ) and a commentary by the Session Chair, Shanta Persaud (DOI: 10.1007/s00125-016-3870-2 ). PMID:27053238

  5. beta-decay of O-13

    NARCIS (Netherlands)

    Knudsen, HH; Fynbo, HOU; Borge, MJG; Boutami, R; Dendooven, P; Diget, CA; Eronen, T; Fox, S; Fraile, LM; Fulton, B; Huikary, J; Jeppesen, HB; Jokinen, AS; Jonson, B; Kankainen, A; Moore, [No Value; Nieminen, A; Nyman, G; Penttila, H; Riisager, K; Rinta-Antila, S; Tengblad, O; Wang, Y; Wilhelmsen, K; Aysto, J

    2005-01-01

    The beta decay of O-13 has been studied at the IGISOL facility of the Jyvaskyla accelerator centre (Finland). By developing a low-energy isotope-separated beam of O-13 and using a modern segmented charged-particle detector array an improved measurement of the delayed proton spectrum was possible. Pr

  6. Beta-glucuronidase-mediated drug release

    NARCIS (Netherlands)

    Boven, E; Scheeren, HW; Haisma, HJ; Pinedo, HM

    2002-01-01

    The selective activation of a relatively non-toxic prodrug by an enzyme present only in the tumour should enhance the drug concentration at the tumour site and result in a better anti-tumour effect and a reduction in systemic toxicity as compared to conventional chemotherapy. beta-Glucuronidase is s

  7. LHC dijet constraints on double beta decay

    CERN Document Server

    Helo, J C

    2015-01-01

    We use LHC dijet data to derive constraints on neutrinoless double beta decay. Upper limits on cross sections for the production of "exotic" resonances, such as a right-handed W boson or a diquark, can be converted into lower limits on the double beta decay half-life for fixed choices of other parameters. Constraints derived from run-I data are already surprisingly strong and complementary to results from searches using same-sign dileptons plus jets. For the case of the left-right symmetric model, in case no new resonance is found in future runs of the LHC and assuming $g_L=g_R$, we estimate a lower limit on the double beta decay half-live larger than $10^{27}$ ys can be derived from future dijet data, except in the window of relatively light right-handed neutrino masses in the range $0.5$ MeV to $50$ GeV. Part of this mass window will be tested in the upcoming SHiP experiment. We also discuss current and future limits on possible scalar diquark contributions to double beta decay that can be derived from dije...

  8. Frameshift mutation events in beta-glucosidases.

    Science.gov (United States)

    Rojas, Antonio; Garcia-Vallvé, Santiago; Montero, Miguel A; Arola, Lluís; Romeu, Antoni

    2003-09-18

    Compensated frameshift mutation is a modification of the reading frame of a gene that takes place by way of various molecular events. It appears to be a widespread event that is only observed when homologous amino acid and nucleodotide sequences are compared. To identify these mutation events, the sequence analysis rationale was based on the search for short regions that would have much lower degrees of conservation in protein, but not in DNA, in well-conserved beta-glucosidase families. We have restricted our study to a seed set of sequences of O-glycoside hydrolase families 1 and 3. We found compensated frameshift mutation in the family of 1 beta-glucosidases for the Erwinia herbicola, Cellulomonas fimi, and (non-cyanogenic) Trifolium repens gene sequences, and in the family of 3 beta-glucosidases for the Clostridium thermocellum and Clostridium stercorarium gene sequences. By computational treatment, the observed mutation events in the gene frameshifting sub-sequence have been neutralised. Each nucleotide insertion must be eliminated and each nucleotide deletion must be substituted by the symbol N (any nucleotide). When the frameshifting fragments of the amino acid sequences were substituted by the computationally neutralised subsequences, the beta-glucosidase alignments were improved. We also discuss the structural implications of the compensated frameshift mutations events. PMID:14527732

  9. Three loop QCD MOM beta-functions

    CERN Document Server

    Gracey, J A

    2011-01-01

    We present the full expressions for the QCD beta-function in the MOMggg, MOMq and MOMh renormalization schemes at three loops for an arbitrary colour group in the Landau gauge. The results for all three schemes are in very good agreement with the SU(3) numerical estimates provided by Chetyrkin and Seidensticker.

  10. Universality in Chiral Random Matrix Theory at $\\beta =1$ and $\\beta =4$

    CERN Document Server

    Sener, M K

    1998-01-01

    In this paper the kernel for spectral correlation functions of the invariant chiral random matrix ensembles with real ($\\beta =1$) and quaternion real ($\\beta = 4$) matrix elements is expressed in terms of the kernel of the corresponding complex Hermitean random matrix ensembles ($\\beta=2$). Such identities are exact in case of a Gaussian probability distribution and, under certain smoothness assumptions, they are shown to be valid asymptotically for an arbitrary finite polynomial potential. They are proved by means of a construction proposed by Brézin and Neuberger. Microscopic universality for all three chiral ensembles then follows from universal behavior for $\\beta =2$ both at the hard edge (shown by Akemann, Damgaard, Magnea and Nishigaki) and at the soft edge of the spectrum (shown by Kanzieper and Freilikher).

  11. RESEARCH OF BETA AS ADEQUATE RISK MEASURE-IS BETA STILL ALIVE?

    Directory of Open Access Journals (Sweden)

    Ante Perković

    2011-02-01

    Full Text Available The capital asset pricing model (CAPM is one of the most important models in financial economics and it has a long history of theoretical and empirical investigations. The main underlying concept of the CAPM model is that assets with a high risk (high beta should earn a higher return than assets with a low risk (low beta and vice versa. The implication which can be drawn out of this is that all assets with a beta above zero bear some risk and therefore their expected return is above the return of the risk-free rate. In this research observation on monthly stock prices on Croatian stock market from January 1st 2005 until December 31st 2009 is used to form our sample. CROBEX index is used as proxy of the market portfolio. The results demonstrate that beta can not be trusted in making investment decisions and rejects the validity of the whole CAPM model on Croatian stock market.

  12. Femtosecond stimulated Raman spectroscopy of ultrafast biophysical reaction dynamics

    Science.gov (United States)

    McCamant, David William

    2004-12-01

    I have developed the technique of femtosecond stimulated Raman spectroscopy (FSRS), which enables the rapid acquisition of vibrational spectra with optical excitation to S2 (1Bu +) the molecule relaxes to S1 in 160 fs where it undergoes rapid two-step IVR with 200- and 450-fs time constants. In later work, the FSRS spectrum of S2 beta-carotene was observed, which consists of three intense and broad bands at ˜1100, 1300 and 1650 cm-1 that exhibit kinetics matching the decay of the S2 near-infrared absorption. These data show that there is no additional intermediate 1B u- electronic state involved in the relaxation pathway of beta-carotene. FSRS was also used to study the photoisomerization dynamics in bacteriorhodopsin (bR). Spectra obtained during bR's excited state lifetime exhibit dispersive lineshapes at the ground-state frequencies that decay in 250 fs and are attributed to a nonlinear emission process. This relaxation is significantly faster than the decay of the stimulated emission (˜500 fs), indicating that the excited population moves away from the ground-state geometry in 250 fs. Spectral changes between 1.5 to 100 ps reveal that a significant fraction of the isomerization occurs on the ground state photoproduct surface. The many benefits FSRS will make it a valuable tool for vibrational spectroscopy of reaction dynamics in ultrafast photochemical and photophysical processes.

  13. Active Beam Spectroscopy

    Science.gov (United States)

    von Hellermann, M. G.; Delabie, E.; Jaspers, R. J. E.; Biel, W.; Marchuk, O.; Summers, H. P.; Whiteford, A.; Giroud, C.; Hawkes, N. C.; Zastrow, K. D.

    2008-03-01

    Charge eXchange Recombination Spectroscopy (CXRS) plays a pivotal role in the diagnostics of hot fusion plasmas and is implemented currently in most of the operating devices. In the present report the main features of CXRS are summarized and supporting software packages encompassing "Spectral Analysis Code CXSFIT", "Charge Exchange Analysis Package CHEAP", and finally "Forward Prediction of Spectral Features" are described. Beam Emission Spectroscopy (BES) is proposed as indispensable cross-calibration tool for absolute local impurity density measurements and also for the continuous monitoring of the neutral beam power deposition profile. Finally, a full exploitation of the `Motional Stark Effect' pattern is proposed to deduce local pitch angles, total magnetic fields and possibly radial electric fields. For the proposed active beam spectroscopy diagnostic on ITER comprehensive performance studies have been carried out. Estimates of expected spectral signal-to-noise ratios are based on atomic modelling of neutral beam stopping and emissivities for CXRS, BES and background continuum radiation as well as extrapolations from present CXRS diagnostic systems on JET, Tore Supra, TEXTOR and ASDEX-UG. Supplementary to thermal features a further promising application of CXRS has been proposed recently for ITER, that is a study of slowing-down alpha particles in the energy range up to 2 MeV making use of the 100 keV/amu DNB (Diagnostic Neutral Beam) and the 500 keV/amu HNB (Heating Neutral Beam). Synthetic Fast Ion Slowing-Down spectra are evaluated in terms of source rates and slowing-down parameters

  14. Herschel detects oxygen in the beta Pictoris debris disk

    CERN Document Server

    Brandeker, A; Olofsson, G; Vandenbussche, B; Acke, B; Barlow, M J; Blommaert, J A D L; Cohen, M; Dent, W R F; Dominik, C; Di Francesco, J; Fridlund, M; Gear, W K; Glauser, A M; Greaves, J S; Harvey, P M; Heras, A M; Hogerheijde, M R; Holland, W S; Huygen, R; Ivison, R J; Leeks, S J; Lim, T L; Liseau, R; Matthews, B C; Pantin, E; Pilbratt, G L; Royer, P; Sibthorpe, B; Waelkens, C; Walker, H J

    2016-01-01

    The young star beta Pictoris is well known for its dusty debris disk, produced through the grinding down by collisions of planetesimals, kilometre-sized bodies in orbit around the star. In addition to dust, small amounts of gas are also known to orbit the star, likely the result from vaporisation of violently colliding dust grains. The disk is seen edge on and from previous absorption spectroscopy we know that the gas is very rich in carbon relative to other elements. The oxygen content has been more difficult to assess, however, with early estimates finding very little oxygen in the gas at a C/O ratio 20x higher than the cosmic value. A C/O ratio that high is difficult to explain and would have far-reaching consequences for planet formation. Here we report on observations by the far-infrared space telescope Herschel, using PACS, of emission lines from ionised carbon and neutral oxygen. The detected emission from C+ is consistent with that previously reported being observed by the HIFI instrument on Herschel,...

  15. Synthesis of magnetite nanoparticles-{beta}-cyclodextrin complex

    Energy Technology Data Exchange (ETDEWEB)

    Cobos Cruz, L.A.; Martinez Perez, C.A. [Instituto de Ingenieria y Tecnologia, Universidad Autonoma de Cd. Juarez, Ave. del Charro 450, Col Partido Romero, C.P. 32360, Cd. Juarez Chih. (Mexico); Monreal Romero, H.A. [Facultad de Odontologia, Universidad Autonoma de Chihuahua, Ciudad Universitaria Campus I, C.P. 31000, Chihuahua, Chi. Mexico (Mexico); Garcia Casillas, P.E. [Instituto de Ingenieria y Tecnologia, Universidad Autonoma de Cd. Juarez, Ave. del Charro 450, Col Partido Romero, C.P. 32360, Cd. Juarez Chih. (Mexico)], E-mail: pegarcia@uacj.mx

    2008-10-20

    In this work, the synthesis and characterization of a magnetite (M) and {beta}-cyclodextrin (CD) complex is presented. The chemical bonding between the magnetite and CD was studied as evidence of host-guest interaction; therefore the CD works like a reactor with the magnetite inside of it, as consequence the growth of the particle is restricted by the electrostatic interaction of M-CD complex. The particle size of the magnetite-cyclodextrin complex (M-CD) decreased 79.1% with 0.5% of CD. The average particle size of the M-CD complex was 10 nm. The saturation magnetization ({sigma}{sub s}) and intrinsic coercivity (H{sub c}) increased 10% and 20%, respectively. In order to understand how the the CD affects the results obtained, the second derivate of remission function was obtained from the ultraviolet-visible spectra (UV-vis). Fourier transform infrared spectroscopy (FTIR) was used to elucidate the interaction between the magnetite and CD. The thermal analysis was measured by thermogravimetric and differential thermal analysis (TGA-DTA). The magnetic properties, intrinsic coercivity (H{sub c}) and the saturation magnetization were determined by vibrating sample magnetometry (VSM); the size and shape of nanoparticles were determined by scanning electron microscopy (SEM). The identification of phases was made by X-ray diffraction.

  16. Resonance ionization spectroscopy

    International Nuclear Information System (INIS)

    The subject of resonance ionization spectroscopy (RIS) from its inception to the present is summarized. The uses of RIS are principally analytical, and these uses are classified in several different ways for this report. The classifications are: (1) basic ways of counting atoms; (2) RIS applications according to the type of particle detector; (3) applications according to source preparation; (4) applications in chemical physics and chemistry; and (5) applications involving daughter atom detection. Each classification is discussed in some detail, and examples of specific applications are mentioned under each classification. Some other potential applications not necessarily related to these classifications are also mentioned

  17. Dark Matter Velocity Spectroscopy

    CERN Document Server

    Speckhard, Eric G; Beacom, John F; Laha, Ranjan

    2016-01-01

    Dark matter decays or annihilations that produce line-like spectra may be smoking-gun signals. However, even such distinctive signatures can be mimicked by astrophysical or instrumental causes. We show that velocity spectroscopy-the measurement of energy shifts induced by relative motion of source and observer-can separate these three causes with minimal theoretical uncertainties. The principal obstacle has been energy resolution, but upcoming and proposed experiments will make significant improvements. As an example, we show that the imminent Astro-H mission can use Milky Way observations to separate possible causes of the 3.5-keV line. We discuss other applications.

  18. Dark Matter Velocity Spectroscopy.

    Science.gov (United States)

    Speckhard, Eric G; Ng, Kenny C Y; Beacom, John F; Laha, Ranjan

    2016-01-22

    Dark matter decays or annihilations that produce linelike spectra may be smoking-gun signals. However, even such distinctive signatures can be mimicked by astrophysical or instrumental causes. We show that velocity spectroscopy-the measurement of energy shifts induced by relative motion of source and observer-can separate these three causes with minimal theoretical uncertainties. The principal obstacle has been energy resolution, but upcoming experiments will have the precision needed. As an example, we show that the imminent Astro-H mission can use Milky Way observations to separate possible causes of the 3.5-keV line. We discuss other applications.

  19. MR spectroscopy in dementia

    International Nuclear Information System (INIS)

    With an increasingly aging population we are faced with the problem of an increasing number of dementia patients. In addition to clinical, neuropsychological and laboratory procedures, MRI plays an important role in the early diagnosis of dementia. In addition to various morphological changes functional changes can also help in the diagnosis and differential diagnosis of dementia. Overall the diagnosis of dementia can be improved by using parameters from MR spectroscopy. This article focuses on MR spectroscopic changes in the physiological aging process as well as on changes in mild cognitive impairment a precursor of Alzheimer's dementia, in Alzheimer's dementia, frontotemporal dementia, vascular dementia and Lewy body dementia. (orig.)

  20. A guide to 17beta-hydroxysteroid dehydrogenases.

    Science.gov (United States)

    Adamski, J; Jakob, F J

    2001-01-22

    17beta-Hydroxysteroid dehydrogenases (17beta-HSD) are pivotal in controlling the biological potency of steroid hormones by catalyzing oxidation or reduction at position 17. Several 17beta-HSDs may as well metabolize further substrates including alcohols, bile acids, fatty acids and retinols. This review summarizes recent progress in the field of 17beta-HSD research provides an update of nomenclature. PMID:11165003

  1. Neutrinoless $\\beta\\beta$ decay nuclear matrix elements in an isotopic chain

    CERN Document Server

    Rodríguez, Tomás R

    2012-01-01

    We analyze nuclear matrix elements (NME) of neutrinoless double beta decay calculated for the Cadmium isotopes. Energy density functional methods including beyond mean field effects such as symmetry restoration and shape mixing are used. Strong shell effects are found associated to the underlying nuclear structure of the initial and final nuclei. Furthermore, we show that NME for two-neutrino double beta decay evaluated in the closure approximation, $M^{2\

  2. Interleukin-1 beta (IL-1 beta) induces thrombocytosis in mice: Possible implication of IL-6

    Energy Technology Data Exchange (ETDEWEB)

    Kimura, H.; Ishibashi, T.; Shikama, Y.; Okano, A.; Akiyama, Y.; Uchida, T.; Maruyama, Y. (Fukushima Medical College (Japan))

    1990-12-15

    We administered recombinant human interleukin-1 beta (IL-1 beta), the common mediator of inflammation process, to C57B1/6 male mice (0.5 microgram, every 12 hours over five times) intraperitoneally and consequently induced a remarkable thrombocytosis. Day 1 was designated as the following day of the last injection in the morning. A significant thrombocytosis was observed on days 1 through 5 with a peak on day 2 (162 +/- 9 x 10(4)/mm3) compared with the control mice injected with heated IL-1 beta (101 +/- 11 x 10(4)/mm3). A striking increase in mean size of marrow megakaryocytes was noted on days 1 and 2. The incorporation of 75Se-selenomethionine into circulating platelets as a measure of platelet production was about 2.3 times higher in IL-1 beta-treated mice than in control mice. To determine which factor(s) is responsible for elicited thrombocytosis, the in vitro studies and bioassays for several hematopoietic factors were performed. IL-1 beta by itself did not stimulate megakaryocytopoiesis in vitro, suggesting that the thrombocytosis is attributed to other factor(s) via IL-1 beta stimulation. Serum colony-stimulating factor (CSF) activity after a single IL-1 beta (0.5 microgram) injection, monitored by colony assay with 10% tested serum, peaked at 3 hours. Formed colonies were mostly granulocyte (G) and granulocyte-macrophage (GM)-types, and studies using rabbit anti-mouse GM-CSF serum or using human marrow as target cells showed that the CSF activity of the tested serum consisted of, at least, GM-CSF and G-CSF. Addition of IL-3 concomitantly with the tested serum gave rise to a greater number of megakaryocytic colonies. Serum IL-3, monitored by IL-3-dependent cell line 32D clone 5, and erythropoietin activities were not detected at serum level in IL-1 beta-treated mice.

  3. Interleukin-1 beta (IL-1 beta) induces thrombocytosis in mice: Possible implication of IL-6

    International Nuclear Information System (INIS)

    We administered recombinant human interleukin-1 beta (IL-1 beta), the common mediator of inflammation process, to C57B1/6 male mice (0.5 microgram, every 12 hours over five times) intraperitoneally and consequently induced a remarkable thrombocytosis. Day 1 was designated as the following day of the last injection in the morning. A significant thrombocytosis was observed on days 1 through 5 with a peak on day 2 (162 +/- 9 x 10(4)/mm3) compared with the control mice injected with heated IL-1 beta (101 +/- 11 x 10(4)/mm3). A striking increase in mean size of marrow megakaryocytes was noted on days 1 and 2. The incorporation of 75Se-selenomethionine into circulating platelets as a measure of platelet production was about 2.3 times higher in IL-1 beta-treated mice than in control mice. To determine which factor(s) is responsible for elicited thrombocytosis, the in vitro studies and bioassays for several hematopoietic factors were performed. IL-1 beta by itself did not stimulate megakaryocytopoiesis in vitro, suggesting that the thrombocytosis is attributed to other factor(s) via IL-1 beta stimulation. Serum colony-stimulating factor (CSF) activity after a single IL-1 beta (0.5 microgram) injection, monitored by colony assay with 10% tested serum, peaked at 3 hours. Formed colonies were mostly granulocyte (G) and granulocyte-macrophage (GM)-types, and studies using rabbit anti-mouse GM-CSF serum or using human marrow as target cells showed that the CSF activity of the tested serum consisted of, at least, GM-CSF and G-CSF. Addition of IL-3 concomitantly with the tested serum gave rise to a greater number of megakaryocytic colonies. Serum IL-3, monitored by IL-3-dependent cell line 32D clone 5, and erythropoietin activities were not detected at serum level in IL-1 beta-treated mice

  4. High-Resolution Conversion Electron Spectroscopy of Valence Electron Configurations (CESVEC) in Solids

    CERN Multimedia

    2002-01-01

    First measurements with the Zurich $\\beta$-spectrometer on sources from ISOLDE have demonstrated that high resolution spectroscopy of conversion electrons from valence shells is feasible.\\\\ \\\\ This makes possible a novel type of electron spectroscopy (CESVEC) on valence-electron configurations of tracer elements in solids. Thus the density of occupied electron states of impurities in solids has been measured for the first time. Such data constitute a stringent test of state-of-the-art calculations of impurity properties. Based on these results, we are conducting a systematic investigation of impurities in group IV and III-V semiconductors.

  5. Effect of heating rate on temperature of titanium alloy (. cap alpha. +. beta. ). -->. beta. transformaton

    Energy Technology Data Exchange (ETDEWEB)

    Gridnev, V.N.; Ivasishin, O.M.; Markovskij, P.E. (AN Ukrainskoj SSR, Kiev. Inst. Metallofiziki)

    1985-01-01

    The effect of doping of two-phase titaniums alloys and morphology of initial structure on the Tsub(t) temperature shift value of (..cap alpha..+..beta..)..--> beta.. transformation depending on heating rate is investigated. It has been found that the Tsub(t) shift occurs in the strictly determined temperature range depending on chemical alloy composition. The Tsub(t) shift is directly proportional to the Ksub(..beta..) coefficient applied as a quantitative alloying characteristic as well as a dimensional factor equal either to the plate thickness or the ..cap alpha..-phase globule diameter depending on the type of initial structure. In the limits of this temperature range the (..cap alpha..+..beta..)..--> beta..-transformation occurs completely according to the diffusion mechanism. The critical heating rate at which maximum permissible Tsub(t) value is attained and above which its stabilization is observed is determined by the same parameters - the alloy doping degree characterized by the Ksub(..beta..) coefficient and the ..cap alpha..-phase crystal dimensions in the initial structure.

  6. Mechanisms of beta-amyloid neurotoxicity : Perspectives of pharmacotherapy

    NARCIS (Netherlands)

    Harkany, T; Abraham, [No Value; Konya, C; Nyakas, C; Zarandi, M; Penke, B; Luiten, PGM

    2000-01-01

    One of the characteristic neuropathological hallmarks of Alzheimer's disease (AD) is the extracellular accumulation of beta -amyloid peptides (A beta) in neuritic plaques, Experimental data indicate that different molecular forms of A beta affect a wide array of neuronal and glial functions and ther

  7. Why Downside Beta Is Better: An Educational Example

    Science.gov (United States)

    Chong, James T.; Jennings, William P.; Phillips, G. Michael

    2013-01-01

    An educational example is presented that is an effective teaching illustration to help students understand the difference between traditional CAPM beta and downside (or down-market) beta and why downside beta is a superior measure for use in personal financial planning investment policy statements.

  8. Natalizumab plus interferon beta-1a for relapsing multiple sclerosis.

    NARCIS (Netherlands)

    Rudick, R.A.; Stuart, W.H.; Calabresi, P.A.; Confavreux, C.; Galetta, S.L.; Radue, E.W.; Lublin, F.D.; Weinstock-Guttman, B.; Wynn, D.R.; Lynn, F.; Panzara, M.A.; Sandrock, A.W.

    2006-01-01

    BACKGROUND: Interferon beta is used to modify the course of relapsing multiple sclerosis. Despite interferon beta therapy, many patients have relapses. Natalizumab, an alpha4 integrin antagonist, appeared to be safe and effective alone and when added to interferon beta-1a in preliminary studies. MET

  9. First forbidden beta decay of some strongly deformed nuclei

    NARCIS (Netherlands)

    Werf, Siebren Ysbrand van der

    1971-01-01

    In this thesis we present measurements of the shape factors of the first forbidden beta decays of the nuclei Tm^170, Re^186, Re^188 and Lu^176m. For Lu^176m, also the beta gamma directionalcorrelation was measured. In chapter I formulas for the observable quantities in first forbidden beta decay and

  10. [beta]-Lactamases in the Biochemistry and Molecular Biology Laboratory

    Science.gov (United States)

    Amador, Paula; Prudencio, Cristina; Vieira, Monica; Ferraz, Ricardo; Fonte, Rosalia; Silva, Nuno; Coelho, Pedro; Fernandes, Ruben

    2009-01-01

    [beta]-lactamases are hydrolytic enzymes that inactivate the [beta]-lactam ring of antibiotics such as penicillins and cephalosporins. The major diversity of studies carried out until now have mainly focused on the characterization of [beta]-lactamases recovered among clinical isolates of Gram-positive staphylococci and Gram-negative…

  11. Induction of beta-lactamase production in Pseudomonas aeruginosa biofilm

    DEFF Research Database (Denmark)

    Giwercman, B; Jensen, E T; Høiby, N;

    1991-01-01

    Imipenem induced high levels of beta-lactamase production in Pseudomonas aeruginosa biofilms. Piperacillin also induced beta-lactamase production in these biofilms but to a lesser degree. The combination of beta-lactamase production with other protective properties of the biofilm mode of growth...

  12. TGF-beta and BMP in breast cancer cell invasion

    NARCIS (Netherlands)

    Naber, Hildegonda Petronella Henriëtte

    2012-01-01

    TGF-beta and BMPs are members of the TGF-beta superfamily of cytokines which play an important role in a multitude of processes. In cancer, TGF-beta is known for its dual role: in early stages it inhibits cancer cell proliferation, whereas in later stages it promotes invasion and metastasis. In this

  13. 21 CFR 886.5100 - Ophthalmic beta radiation source.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic beta radiation source. 886.5100 Section... (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Therapeutic Devices § 886.5100 Ophthalmic beta radiation source. (a) Identification. An ophthalmic beta radiation source is a device intended to apply...

  14. Bridged bis(beta-cyclodextrin)s possessing coordinated metal center(s) and their inclusion complexation behavior with model substrates: enhanced molecular binding ability by multiple recognition.

    Science.gov (United States)

    Liu, Y; Chen, Y; Li, L; Zhang, H Y; Liu, S X; Guan, X D

    2001-12-14

    To investigate quantitatively the cooperative binding ability of several beta-cyclodextrin oligomers bearing single or multiligated metal center(s), the inclusion complexation behavior of four bis(beta-cyclodextrin)s (2-5) linked by 2,2'-bipyridine-4,4'-dicarboxy tethers and their copper(II) complexes (6-9) with representative dye guests, i.e., methyl orange (MO), acridine red (AR), rhodamine B (RhB), ammonium 8-anilino-1-naphthalenesulfonic acid (ANS), and sodium 6-(p-toludino)-2-naphthalenesulfonate (TNS), have been examined in aqueous solution at 25 degrees C by means of UV-vis, circular dichroism, fluorescence, and 2D NMR spectroscopy. The results obtained indicate that bis(beta-cyclodextrin)s 2-5 can associate with one or three copper(II) ion(s) producing 2:1 or 2:3 bis(beta-cyclodextrin)-copper(II) complexes. These metal-ligated oligo(beta-cyclodextrin)s can bind two model substrates to form intramolecular 2:2 host-guest inclusion complexes and thus significantly enhance the original binding abilities of parent beta-cyclodextrin and bis(beta-cyclodextrin) toward model substrates through the cooperative binding of two guest molecules by four tethered cyclodextrin moieties, as well as the additional binding effect supplied by ligated metal center(s). Host 6 showed the highest enhancement of the stability constant, up to 38.3 times for ANS as compared with parent beta-cyclodextrin. The molecular binding mode and stability constant of substrates by bridged bis- and oligo(beta-cyclodextrin)s 2-9 are discussed from the viewpoint of the size/shape-fit interaction and molecular multiple recognition between host and guest.

  15. Wave mixing spectroscopy

    International Nuclear Information System (INIS)

    Several new aspects of nonlinear or wave mixing spectroscopy were investigated utilizing the polarization properties of the nonlinear output field and the dependence of this field upon the occurrence of multiple resonances in the nonlinear susceptibility. First, it is shown theoretically that polarization-sensitive detection may be used to either eliminate or controllably reduce the nonresonant background in coherent anti-Stokes Raman spectroscopy, allowing weaker Raman resonances to be studied. The features of multi-resonant four-wave mixing are examined in the case of an inhomogeneously broadened medium. It is found that the linewidth of the nonlinear output narrows considerably (approaching the homogeneous width) when the quantum mechanical expressions for the doubly- and triply-resonant susceptibilities are averaged over a Doppler or strain broadened profile. Experimental studies of nonlinear processes in Pr+3:LaF3 verify this linewidth narrowing, but indicate that this strain broadened system cannot be treated with a single broadening parameter as in the case of Doppler broadening in a gas. Several susceptibilities are measured from which are deduced dipole matrix elements and Raman polarizabilities related to the 3H4, 3H6, and 3P0 levels of the praseodymium ions

  16. Wave mixing spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.W.

    1980-08-01

    Several new aspects of nonlinear or wave mixing spectroscopy were investigated utilizing the polarization properties of the nonlinear output field and the dependence of this field upon the occurrence of multiple resonances in the nonlinear susceptibility. First, it is shown theoretically that polarization-sensitive detection may be used to either eliminate or controllably reduce the nonresonant background in coherent anti-Stokes Raman spectroscopy, allowing weaker Raman resonances to be studied. The features of multi-resonant four-wave mixing are examined in the case of an inhomogeneously broadened medium. It is found that the linewidth of the nonlinear output narrows considerably (approaching the homogeneous width) when the quantum mechanical expressions for the doubly- and triply-resonant susceptibilities are averaged over a Doppler or strain broadened profile. Experimental studies of nonlinear processes in Pr/sup +3/:LaF/sub 3/ verify this linewidth narrowing, but indicate that this strain broadened system cannot be treated with a single broadening parameter as in the case of Doppler broadening in a gas. Several susceptibilities are measured from which are deduced dipole matrix elements and Raman polarizabilities related to the /sup 3/H/sub 4/, /sup 3/H/sub 6/, and /sup 3/P/sub 0/ levels of the praseodymium ions.

  17. Neutron resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gunsing, F

    2005-06-15

    The present document has been written in order to obtain the diploma 'Habilitation a Diriger des Recherches'. Since this diploma is indispensable to supervise thesis students, I had the intention to write a document that can be useful for someone starting in the field of neutron resonance spectroscopy. Although the here described topics are already described elsewhere, and often in more detail, it seemed useful to have most of the relevant information in a single document. A general introduction places the topic of neutron-nucleus interaction in a nuclear physics context. The large variations of several orders of magnitude in neutron-induced reaction cross sections are explained in terms of nuclear level excitations. The random character of the resonances make nuclear model calculation predictions impossible. Then several fields in physics where neutron-induced reactions are important and to which I have contributed in some way or another, are mentioned in a first synthetic chapter. They concern topics like parity nonconservation in certain neutron resonances, stellar nucleosynthesis by neutron capture, and data for nuclear energy applications. The latter item is especially important for the transmutation of nuclear waste and for alternative fuel cycles. Nuclear data libraries are also briefly mentioned. A second chapter details the R-matrix theory. This formalism is the foundation of the description of the neutron-nucleus interaction and is present in all fields of neutron resonance spectroscopy. (author)

  18. The X-Array and SATURN: A new decay-spectroscopy station for CARIBU

    CERN Document Server

    Mitchell, A J; DiGiovine, B; Lister, C J; Carpenter, M P; Chowdhury, P; Clark, J A; D'Olympia, N; Deo, A Y; Kondev, F G; McCutchan, E A; Rohrer, J; Savard, G; Seweryniak, D; Zhu, S

    2015-01-01

    A new decay-spectroscopy station has been commissioned for experiments with low-energy, fission-fragment radioactive beams from the CARIBU ion source. The new set-up consists of the 'X-array', a highly-efficient array of HPGe clover detectors, and 'SATURN' (Scintillator And Tape Using Radioactive Nuclei), a plastic scintillator detector combined with a tape-transport system for detection of beta particles and removal of long-lived isobaric decay products.

  19. {beta}-Carotene to bacteriochlorophyll c energy transfer in self-assembled aggregates mimicking chlorosomes

    Energy Technology Data Exchange (ETDEWEB)

    Alster, J. [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Praha (Czech Republic); Polivka, T. [Institute of Physical Biology, University of South Bohemia, Zamek 136, 373 33 Nove Hrady (Czech Republic); Biology Centre, Academy of Sciences of the Czech Republic, Branisovska 31, 370 05 Ceske Budejovice (Czech Republic); Arellano, J.B. [Instituto de Recursos Naturales y Agrobiologia de Salamanca (IRNASA-CSIC), Apdo. 257, 37071 Salamanca (Spain); Chabera, P. [Institute of Physical Biology, University of South Bohemia, Zamek 136, 373 33 Nove Hrady (Czech Republic); Vacha, F. [Institute of Physical Biology, University of South Bohemia, Zamek 136, 373 33 Nove Hrady (Czech Republic); Biology Centre, Academy of Sciences of the Czech Republic, Branisovska 31, 370 05 Ceske Budejovice (Czech Republic); Psencik, J., E-mail: psencik@karlov.mff.cuni.cz [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16 Praha (Czech Republic); Institute of Physical Biology, University of South Bohemia, Zamek 136, 373 33 Nove Hrady (Czech Republic)

    2010-07-19

    Carotenoids are together with bacteriochlorophylls important constituents of chlorosomes, the light-harvesting antennae of green photosynthetic bacteria. Majority of bacteriochlorophyll molecules form self-assembling aggregates inside the chlorosomes. Aggregates of bacteriochlorophylls with optical properties similar to those of chlorosomes can also be prepared in non-polar organic solvents or in aqueous environments when a suitable non-polar molecule is added. In this work, the ability of {beta}-carotene to induce aggregation of bacteriochlorophyll c in aqueous buffer was studied. Excitation relaxation and energy transfer in the carotenoid-bacteriochlorophyll assemblies were measured using femtosecond and nanosecond transient absorption spectroscopy. A fast, {approx}100-fs energy transfer from the S{sub 2} state of {beta}-carotene to bacteriochlorophyll c was revealed, while no evidence for significant energy transfer from the S{sub 1} state was found. Picosecond formation of the carotenoid triplet state (T{sub 1}) was observed, which was likely generated by singlet homo-fission from the S{sub 1} state of {beta}-carotene.

  20. Synthesis of a metal binding protein designed on the alpha/beta scaffold of charybdotoxin.

    Science.gov (United States)

    Pierret, B; Virelizier, H; Vita, C

    1995-12-01

    The alpha/beta scaffold of the scorpion toxin charybdotoxin has been used for the engineering of a metal binding site. Nine substitutions, including three histidines as metal ligands, have been introduced into the original toxin sequence. The newly designed sequence, 37 amino acids long, has been assembled by solid-phase synthesis and HBTU (2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate) coupling of Fmoc-protected amino acids. Formation of the three disulfide bonds occurred efficiently and rapidly in the presence of glutathione, and this post-synthesis modification has facilitated the purification task enormously. The process of synthesis and purification was performed in less than a week with an overall 10.2% yield. Circular dichroism analysis showed that the newly designed protein is folded in a alpha/beta structure, similarly to the parent toxin. Electronic absorption spectroscopy, circular dichroism and gel filtration experiments have been used to show that Cu2+ and Zn2+ ions bind with high affinity to the newly engineered protein. These results demonstrate that the alpha/beta fold, common to all scorpion toxins, is a very versatile basic structure, tolerant for substitutions and able to present new sequences in a predetermined conformation. The chemical approach is shown to be effective, rapid and practical for the production of novel designed small proteins.

  1. Periodic Radio Continuum Emission Associated with the beta Cephei Star V2187 Cyg

    CERN Document Server

    Tapia, Mauricio; Tovmassian, Gagik; Rodriguez-Gomez, Vicente; Gonzalez-Buitrago, Diego; Zharikov, Sergei; Ortiz-Leon, Gisela N

    2014-01-01

    We present new optical time-resolved photometry and medium-resolution spectroscopy of V2187 Cyg. We confirm its classification as a beta Cephei star based on sinusoidal light variations with a period of 0.2539 days and mean amplitudes of 0.037 and 0.042 magnitudes in "i" and "V", respectively. We classified the spectrum of this star B2-3V with no evidence of variations in the profiles of its absorption lines in timescales of hours or days. The stellar spectrum is totally absent of emission lines. We detected unexpected faint radio continuum emission (between 0.4 and 0.8 mJy at 6-cm) showing a sinusoidal variation with a period of 12.8 days. The radio spectrum is thermal. We searched in the Very Large Array archive for radio continuum emission toward other 15 beta Cephei stars. None of these additional stars, some of them much closer to the Sun than V2187 Cyg, was detected, indicating that radio emission is extremely uncommon toward beta Cephei stars.

  2. On the H$\\alpha$ emission from the $\\beta$ Cephei system

    CERN Document Server

    Schnerr, R S; Oudmaijer, R D; Telting, J H

    2006-01-01

    Be stars, which are characterised by intermittent emission in their hydrogen lines, are known to be fast rotators. This fast rotation is a requirement for the formation of a Keplerian disk, which in turn gives rise to the emission. However, the pulsating, magnetic B1IV star $\\beta$ Cephei is a very slow rotator that still shows H$\\alpha$ emission episodes like in other Be stars, contradicting current theories. We investigate the hypothesis that the H$\\alpha$ emission stems from the spectroscopically unresolved companion of $\\beta$ Cep. Spectra of the two unresolved components have been separated in the 6350-6850\\AA range with spectro-astrometric techniques, using 11 longslit spectra obtained with ALFOSC at the Nordic Optical Telescope, La Palma. We find that the H$\\alpha$ emission is not related to the primary in $\\beta$ Cep, but is due to its 3.4 magnitudes fainter companion. This companion has been resolved by speckle techniques, but it remains unresolved by traditional spectroscopy. The emission extends fr...

  3. Preparation of hydroxyapatite nanoparticles facilitated by the presence of {beta}-cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Perez, Carlos A., E-mail: camartin@uacj.mx [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Garcia-Montelongo, Jorge; Garcia Casillas, Perla E.; Farias-Mancilla, Jose R. [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Monreal Romero, Humberto [School of Odontology, Autonomous University of Chihuahua, UACH, Ave. Universidad s/n Campus Universitario I, C.P. 31170, Chihuahua (Mexico)

    2012-09-25

    Highlights: Black-Right-Pointing-Pointer It was found that {beta}-cyclodextrin can control the particle size in the production of nanohydroxyapatite. Black-Right-Pointing-Pointer Particle size in the range of 30-50 nm was obtained. Black-Right-Pointing-Pointer A new simple methodology for the preparation of hydroxyapatite nanoparticles with a well controlled size and narrow particles size distribution was developed. - Abstract: Hydroxyapatite nanoparticles with uniform morphology have been successfully synthesized by a chemical coprecipitation method and facilitated by the presence of the {beta}-cyclodextrin. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM); and Fourier Transformed Infrared Spectroscopy (FT-IR) were used in order to characterize the hydroxyapatite samples. The experimental results indicate that the obtained HA is in the range of 20-50 nm. Also it was found that the content of {beta}-CD has an impact on the purity of the HA as well in the particle size of the hydroxyapatite nanoparticles.

  4. Enhancement of wear and corrosion resistance of beta titanium alloy by laser gas alloying with nitrogen

    Science.gov (United States)

    Chan, Chi-Wai; Lee, Seunghwan; Smith, Graham; Sarri, Gianluca; Ng, Chi-Ho; Sharba, Ahmed; Man, Hau-Chung

    2016-03-01

    The relatively high elastic modulus coupled with the presence of toxic vanadium (V) in Ti6Al4V alloy has long been a concern in orthopaedic applications. To solve the problem, a variety of non-toxic and low modulus beta-titanium (beta-Ti) alloys have been developed. Among the beta-Ti alloy family, the quaternary Ti-Nb-Zr-Ta (TNZT) alloys have received the highest attention as a promising replacement for Ti6Al4V due to their lower elastic modulus and outstanding long term stability against corrosion in biological environments. However, the inferior wear resistance of TNZT is still a problem that must be resolved before commercialising in the orthopaedic market. In this work, a newly developed laser surface treatment technique was employed to improve the surface properties of Ti-35.3Nb-7.3Zr-5.7Ta alloy. The surface structure and composition of the laser-treated TNZT surface were examined by grazing incidence X-ray diffraction (GI-XRD) and X-ray photoelectron spectroscopy (XPS). The wear and corrosion resistance were evaluated by pin-on-plate sliding test and anodic polarisation test in Hanks' solution. The experimental results were compared with the untreated (or base) TNZT material. The research findings showed that the laser surface treatment technique reported in this work can effectively improve the wear and corrosion resistance of TNZT.

  5. Beta-glucuronidase-mediated drug release.

    Science.gov (United States)

    de Graaf, Michelle; Boven, Epie; Scheeren, Hans W; Haisma, Hidde J; Pinedo, Herbert M

    2002-01-01

    The selective activation of a relatively non-toxic prodrug by an enzyme present only in the tumour should enhance the drug concentration at the tumour site and result in a better anti-tumour effect and a reduction in systemic toxicity as compared to conventional chemotherapy. beta-Glucuronidase is such an enzyme. It is normally expressed in the lysosomes of cells. In larger tumours, however, high levels of the enzyme are present in necrotic areas. Several glucuronide prodrugs have been synthesised that can be activated by beta-glucuronidase. They are relatively non-toxic due to their hydrophilic nature, which prevents them from entering cells and thus from contact with lysosomal beta-glucuronidase. The main problem of glucuronide prodrugs for clinical use is their fast renal clearance. Special attention should be paid to the development of new less hydrophilic prodrugs with slower clearance, as this would result in a prolonged exposure to beta-glucuronidase at the site of the tumour and a reduction of the amount of prodrug needed. A number of interesting anthracyclin-based glucuronide prodrugs have been synthesised and have shown favourable therapeutic effects compared to treatment with the parent drug. The tumoural levels of beta-glucuronidase can even be enhanced by two-step approaches, in which exogenous enzyme is targeted to the tumour by an antibody (ADEPT) or by the gene encoding the enzyme in transduced tumour cells (GDEPT). The ADEPT and GDEPT approaches in combination with glucuronide prodrugs have shown enhanced efficacy in experimental tumour models. Further improvement of ADEPT and GDEPT is warranted to optimise the tumour uptake and retention of antibody-enzyme fusion proteins and the efficiency and safety of current gene delivery methods. In conclusion, it is clear that glucuronide prodrugs hold promise for future use in the treatment of cancer in patients as monotherapy. Enhancement of the therapeutic effects of glucuronide prodrugs, also in patients

  6. Vibrational spectroscopy at electrified interfaces

    CERN Document Server

    Wieckowski, Andrzej; Braunschweig, Björn

    2013-01-01

    Reviews the latest theory, techniques, and applications Surface vibrational spectroscopy techniques probe the structure and composition of interfaces at the molecular level. Their versatility, coupled with their non-destructive nature, enables in-situ measurements of operating devices and the monitoring of interface-controlled processes under reactive conditions. Vibrational Spectroscopy at Electrified Interfaces explores new and emerging applications of Raman, infrared, and non-linear optical spectroscopy for the study of charged interfaces. The book draws from hu

  7. Array-based photoacoustic spectroscopy

    Science.gov (United States)

    Autrey, S. Thomas; Posakony, Gerald J.; Chen, Yu

    2005-03-22

    Methods and apparatus for simultaneous or sequential, rapid analysis of multiple samples by photoacoustic spectroscopy are disclosed. A photoacoustic spectroscopy sample array including a body having at least three recesses or affinity masses connected thereto is used in conjunction with a photoacoustic spectroscopy system. At least one acoustic detector is positioned near the recesses or affinity masses for detection of acoustic waves emitted from species of interest within the recesses or affinity masses.

  8. Photoelectron photoion molecular beam spectroscopy

    International Nuclear Information System (INIS)

    The use of supersonic molecular beams in photoionization mass spectroscopy and photoelectron spectroscopy to assist in the understanding of photoexcitation in the vacuum ultraviolet is described. Rotational relaxation and condensation due to supersonic expansion were shown to offer new possibilities for molecular photoionization studies. Molecular beam photoionization mass spectroscopy has been extended above 21 eV photon energy by the use of Stanford Synchrotron Radiation Laboratory (SSRL) facilities. Design considerations are discussed that have advanced the state-of-the-art in high resolution vuv photoelectron spectroscopy. To extend gas-phase studies to 160 eV photon energy, a windowless vuv-xuv beam line design is proposed

  9. Beta-hypergeometric probability distribution on symmetric matrices

    OpenAIRE

    Hassairi, Abdelhamid; Masmoudi, Mouna

    2012-01-01

    Some remarkable properties of the beta distribution are based on relations involving independence between beta random variables such that a parameter of one among them is the sum of the parameters of an other (see (1.1) et (1.2) below). Asci, Letac and Piccioni \\cite{6} have used the real beta-hypergeometric distribution on $ \\reel$ to give a general version of these properties without the condition on the parameters. In the present paper, we extend the properties of the real beta to the beta...

  10. Beta-lactamases of Mycobacterium tuberculosis and Mycobacterium kansasii.

    Science.gov (United States)

    Segura, C; Salvadó, M

    1997-09-01

    Re-emergence of infectious diseases caused by mycobacteria as well as the emergence of multiresistant strains of Mycobacterium has promoted the research on the use of beta-lactames in the treatment of such diseases. Mycobacteria produce beta-lactamases: M. tuberculosis produces a wide-spectrum beta-lactamase whose behaviour mimicks those of Gram-negative bacteria. M. kansasii produces also beta-lactamase which can be inhibited by clavulanic acid. An overview on beta-lactamases from both species is reported.

  11. Comparative evaluation of a new beta-lactamase inhibitor, YTR 830, combined with different beta-lactam antibiotics against bacteria harboring known beta-lactamases.

    OpenAIRE

    Gutmann, L; Kitzis, M D; Yamabe, S; Acar, J F

    1986-01-01

    YTR 830, a new beta-lactamase inhibitor, combined with amoxicillin or carbenicillin, showed a synergistic effect similar to that observed with clavulanic acid, and generally better than that with sulbactam, against strains harboring chromosome-encoded penicillinases and broad-spectrum beta-lactamases or plasmid-determined beta-lactamases. With ampicillin, YTR 830 showed the best synergistic activity of the inhibitors against Proteus morganii, Citrobacter freundii, and Enterobacter cloacae and...

  12. Bactericidal interactions of a beta-lactam and beta-lactamase inhibitors in experimental Pseudomonas aeruginosa endocarditis caused by a constitutive overproducer of type Id beta-lactamase.

    OpenAIRE

    Bayer, A S; Selecky, M; Babel, K; Hirano, L; Yih, J; Parr, T R

    1987-01-01

    We investigated the in vitro and in vivo effects of a combination of a beta-lactam (ceftazidime) and a beta-lactamase inhibitor (dicloxacillin) to synergistically kill a ceftazidime-resistant variant, Pseudomonas aeruginosa PA-48, which overproduces type Id cephalosporinase constitutively. In vitro, dicloxacillin plus ceftazidime exerted bactericidal synergy at approximately 10(5) CFU/ml of inoculum (but not at approximately 10(7)-CFU inoculum), whereas other beta-lactamase inhibitors (sulbac...

  13. Genetic counselling in the beta-thalassaemias

    Directory of Open Access Journals (Sweden)

    Adonis S. Ioannides

    2013-03-01

    Full Text Available The beta-thalassaemias are very important genetic disorders of haemoglobin synthesis and are amongst the commonest monogenic disorders. In view of the severity of beta-thalassaemia major, a number of screening programmes have been developed aimed at reducing the number of individuals born with the condition. Genetic counsellingplays a vital role in this process supporting the successful implementation of screening and delineating available options to at risk individuals. This review assesses the contribution of genetic counsellingat each stage of this process in the context of new diagnostic techniques and therapeutic options and discusses some of the more challenging aspects such as genotype/ phenotype correlation and coinheritance of other genetic conditions or genetic modifiers.

  14. Beta-plane turbulence: experiments with altimetry

    CERN Document Server

    Zhang, Y

    2013-01-01

    Results from a new series of experiments on flows generated by an electromagnetic method in a rotating tank with topographic beta-effect are presented. The velocity fields are measured by the Altimetric Imaging Velocimetry. The turbulent flows observed in the experiments develop zonal jets which are latent in a stationary forced-dissipative regime of the flow but become prominent in the decaying flow. The two-dimensional energy spectra of the flows exhibit the development of anisotropy towards zonal motions. The experiments demonstrate dual turbulent cascade with energy and enstrophy ranges. The frequency-wavenumber spectra reveal the presence of Rossby waves at low wavenumbers which are excited by the turbulent motions. The experimental results are compared with available theory of beta-plane turbulence.

  15. The NEXT double beta decay experiment

    Science.gov (United States)

    Laing, A.; NEXT Collaboration

    2016-05-01

    NEXT (Neutrino Experiment with a Xenon TPC) is a neutrinoless double-beta (ββ0v) decay experiment at Laboratorio Subterraneo de Canfranc (LSC). It is an electroluminescent Time Projection Chamber filled with high pressure 136Xe gas with separated function capabilities for calorimetry and tracking. Energy resolution and background suppression are the two key features of any neutrinoless double beta decay experiment. NEXT has both good energy resolution (LSC. It will validate the NEXT background rate expectations and will make first measurements of the two neutrino ββ2v mode of 136Xe. Furthermore, the NEXT technique can be extrapolated to the tonne scale, thus allowing the full exploration of the inverted hierarchy of neutrino masses. These proceedings review NEXT R&D results, the status of detector commissioning at LSC and the NEXT physics case.

  16. Source preparations for alpha and beta measurements

    Energy Technology Data Exchange (ETDEWEB)

    Holm, E. [Risoe National Lab., Roskilde (Denmark)

    2001-01-01

    Regarding alpha particle emitters subject for environmental studies, electrodeposition or co-precipitation as fluorides are the most common methods. For electro deposition stainless steel is generally used as cathode material but also other metals such as Ni, Ag, and Cu showed promising results. The use of other anode material than platinum, such as graphite should be investigated. For other purposes such as optimal resolution other more sophisticated methods are used but often resulting in poorer recovery. For beta particle emitters the type of detection system will decide the source preparation. Similar methods as for alpha particle emitters, electrodeposition or precipitation techniques can be used. Due to the continuous energy distribution of the beta pulse height distribution a high resolution is not required. Thicker sources from the precipitates or a stable isotopic carrier can be accepted but correction for absorption in the source must be done. (au)

  17. Search for Neutrinoless Double-Beta Decay

    CERN Document Server

    Tornow, Werner

    2014-01-01

    After the pioneering work of the Heidelberg-Moscow (HDM) and International Germanium Experiment (IGEX) groups, the second round of neutrinoless double-$\\beta$ decay searches currently underway has or will improve the life-time limits of double-$\\beta$ decay candidates by a factor of two to three, reaching in the near future the $T_{1/2} = 3 \\times 10^{25}$ yr level. This talk will focus on the large-scale experiments GERDA, EXO-200, and KamLAND-Zen, which have reported already lower half-life time limits in excess of $10^{25}$ yr. Special emphasis is given to KamLAND-Zen, which is expected to approach the inverted hierarchy regime before future 1-ton experiments probe completely this life-time or effective neutrino-mass regime, which starts at $\\approx 2 \\times 10^{26}$ yr or $\\approx 50$ meV.

  18. Numerical models for high beta magnetohydrodynamic flow

    International Nuclear Information System (INIS)

    The fundamentals of numerical magnetohydrodynamics for highly conducting, high-beta plasmas are outlined. The discussions emphasize the physical properties of the flow, and how elementary concepts in numerical analysis can be applied to the construction of finite difference approximations that capture these features. The linear and nonlinear stability of explicit and implicit differencing in time is examined, the origin and effect of numerical diffusion in the calculation of convective transport is described, and a technique for maintaining solenoidality in the magnetic field is developed. Many of the points are illustrated by numerical examples. The techniques described are applicable to the time-dependent, high-beta flows normally encountered in magnetically confined plasmas, plasma switches, and space and astrophysical plasmas. 40 refs

  19. Autoradiographic localization of beta-adrenoreceptors in rat uterus

    Energy Technology Data Exchange (ETDEWEB)

    Tolszczuk, M.; Pelletier, G.

    1988-12-01

    The inhibitory effects of catecholamines on uterine smooth muscle are known to be mediated through beta-adrenergic receptors. To investigate further the distribution of these receptors in the rat uterus, we utilized in vitro autoradiography using ( SVI)-cyanopindolol (CYP), a specific beta-receptor ligand that has equal activity for both beta 1- and beta 2-receptor subtypes. The specificity of the labeling and the characterization of receptor subtypes in different cell types were achieved by displacement of radioligand with increasing concentrations of zinterol, a beta-adrenergic agonist with preferential affinity for the beta 2-adrenoreceptor subtype, and practolol, a beta-adrenergic antagonist that binds preferentially to the beta 1-subtype. Quantitative estimation of ligand binding was performed by densitometry. It was shown that the vast majority of beta-adrenoreceptors were of the beta 2-subtype and were found in high concentration not only in the myometrium but also in the endometrial and serosal epithelia. Specific labeling was also observed in glandular elements. These results suggest that beta-adrenoreceptors might be involved in different functions in the uterus.

  20. Nonlinear Dynamic Force Spectroscopy

    CERN Document Server

    Björnham, Oscar

    2016-01-01

    Dynamic force spectroscopy (DFS) is an experimental technique that is commonly used to assess information of the strength, energy landscape, and lifetime of noncovalent bio-molecular interactions. DFS traditionally requires an applied force that increases linearly with time so that the bio-complex under investigation is exposed to a constant loading rate. However, tethers or polymers can modulate the applied force in a nonlinear regime. For example, bacterial adhesion pili and polymers with worm-like chain properties are examples of structures that show nonlinear force responses. In these situations, the theory for traditional DFS cannot be readily applied. In this work we expand the theory for DFS to also include nonlinear external forces while still maintaining compatibility with the linear DFS theory. To validate the theory we modeled a bio-complex expressed on a stiff, an elastic and a worm-like chain polymer, using Monte Carlo methods, and assessed the corresponding rupture force spectra. It was found th...

  1. Advances in atomic spectroscopy

    CERN Document Server

    Sneddon, J

    1998-01-01

    This volume continues the series'' cutting-edge reviews on developments in this field. Since its invention in the 1920s, electrostatic precipitation has been extensively used in industrial hygiene to remove dust and particulate matter from gases before entering the atmosphere. This combination of electrostatic precipitation is reported upon in the first chapter. Following this, chapter two reviews recent advances in the area of chemical modification in electrothermal atomization. Chapter three consists of a review which deal with advances and uses of electrothermal atomization atomic absorption spectrometry. Flow injection atomic spectroscopy has developed rapidly in recent years and after a general introduction, various aspects of this technique are looked at in chapter four. Finally, in chapter five the use of various spectrometric techniques for the determination of mercury are described.

  2. Near-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Virendra Jain

    2015-01-01

    Full Text Available Tissue ischaemia can be a significant contributor to increased morbidity and mortality. Conventional oxygenation monitoring modalities measure systemic oxygenation, but regional tissue oxygenation is not monitored. Near-infrared spectroscopy (NIRS is a non-invasive monitor for measuring regional oxygen saturation which provides real-time information. There has been increased interest in the clinical application of NIRS following numerous studies that show improved outcome in various clinical situations especially cardiac surgery. Its use has shown improved neurological outcome and decreased postoperative stay in cardiac surgery. Its usefulness has been investigated in various high risk surgeries such as carotid endarterectomy, thoracic surgeries, paediatric population and has shown promising results. There is however, limited data supporting its role in neurosurgical population. We strongly feel, it might play a key role in future. It has significant advantages over other neuromonitoring modalities, but more technological advances are needed before it can be used more widely into clinical practice.

  3. Spectroscopy Made Easy: Evolution

    CERN Document Server

    Piskunov, Nikolai

    2016-01-01

    Context. The Spectroscopy Made Easy (SME) package has become a popular tool for analyzing stellar spectra, often in connection with large surveys or exoplanet research. SME has evolved significantly since it was first described in 1996, but many of the original caveats and potholes still haunt users. The main drivers for this paper are complexity of the modeling task, the large user community, and the massive effort that has gone into SME. Aims. We do not intend to give a comprehensive introduction to stellar atmospheres, but will describe changes to key components of SME: the equation of state, opacities, and radiative transfer. We will describe the analysis and fitting procedure and investigate various error sources that affect inferred parameters. Methods. We review the current status of SME, emphasizing new algorithms and methods. We describe some best practices for using the package, based on lessons learned over two decades of SME usage. We present a new way to assess uncertainties in derived stellar pa...

  4. Quantitative velocity modulation spectroscopy

    Science.gov (United States)

    Hodges, James N.; McCall, Benjamin J.

    2016-05-01

    Velocity Modulation Spectroscopy (VMS) is arguably the most important development in the 20th century for spectroscopic study of molecular ions. For decades, interpretation of VMS lineshapes has presented challenges due to the intrinsic covariance of fit parameters including velocity modulation amplitude, linewidth, and intensity. This limitation has stifled the growth of this technique into the quantitative realm. In this work, we show that subtle changes in the lineshape can be used to help address this complexity. This allows for determination of the linewidth, intensity relative to other transitions, velocity modulation amplitude, and electric field strength in the positive column of a glow discharge. Additionally, we explain the large homogeneous component of the linewidth that has been previously described. Using this component, the ion mobility can be determined.

  5. Analyzing Impedance Spectroscopy Results

    Institute of Scientific and Technical Information of China (English)

    Yoed Tsur; Sioma Baltianski

    2006-01-01

    In this contribution we briefly discuss several analysis techniques for impedance spectroscopy experiments. A number of different approaches, which differ even by the definition of the problem, are used in the literature. Some aimed towards finding an equivalent circuit. Others aimed towards finding directly dielectric properties of the material under an assumed model. Others towards finding distribution of relaxation times, either parametric or point-by point. No matter what the approach is, this will always be an ill-posed problem in the sense that there exist a large number of possible solutions that solve the problem (mathematically) equally well. Therefore some a-priori knowledge about the system must be used. In addition, we should remember that the ultimate goal is to get physical insight about the system.

  6. Theory overview on spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed

    2011-08-15

    A theoretical overview of the exotic spectroscopy in the charm and beauty quark sector is presented. These states are unexpected harvest from the e{sup +}e{sup -} and hadron colliders and a permanent abode for the majority of them has yet to be found. We argue that some of these states, in particular the Y{sub b}(10890) and the recently discovered states Z{sub b}(10610) and Z{sub b}(10650), discovered by the Belle collaboration are excellent candidates for tetraquark states [bq][ anti b anti q], with q=u,d light quarks. Theoretical analyses of the Belle data carried out in the tetraquark context is reviewed. (orig.)

  7. Raman spectroscopy of magnetoliposomes

    International Nuclear Information System (INIS)

    In this study Raman spectroscopy was used to investigate monolayer and bilayer magnetite-based magnetoliposomes (MLs). The Raman probe is the hydroxyl (OH) group chemisorbed at the magnetite nanoparticle surface. Measurements were performed at room temperature in the typical OH stretching region. The data gathered for both samples are compared to each other and with those obtained for pure water. In comparison to liquid water (2.74 kcal/mol), it was found that the hydrogen bond strength between the chemisorbed OH-group and the polar headgroup of the inner phospholipid layer was reduced in both the monolayer (2.22 kcal/mol) and the bilayer (1.83 kcal/mol) ML samples

  8. Transit spectroscopy with GTC

    Directory of Open Access Journals (Sweden)

    Osorio M.R. Zapatero

    2013-04-01

    Full Text Available Thanks to different ground-based surveys and space missions, nowadays we have a fairly large sample of discovered extra-solar planets to study and, without a doubt, this number will increase in the future. One of the most succesful techniques that allows us to prove the physical properties and atmospheric composition of these exoplanets is transmission spectroscopy. The level of precision that is require to measure these effects provides a technical challenge that is solved by using big telescopes and stable instruments to reach low noise levels. In this article, we will discuss the use of the 10m class telescope GTC to observed planetary transits in spectroscopic mode and some of the results that we are currently obtaining.

  9. Femtosecond Stimulated Raman Spectroscopy.

    Science.gov (United States)

    Dietze, Daniel R; Mathies, Richard A

    2016-05-01

    Femtosecond stimulated Raman spectroscopy (FSRS) is an ultrafast nonlinear optical technique that provides vibrational structural information with high temporal (sub-50 fs) precision and high spectral (10 cm(-1) ) resolution. Since the first full demonstration of its capabilities ≈15 years ago, FSRS has evolved into a mature technique, giving deep insights into chemical and biochemical reaction dynamics that would be inaccessible with any other technique. It is now being routinely applied to virtually all possible photochemical reactions and systems spanning from single molecules in solution to thin films, bulk crystals and macromolecular proteins. This review starts with an historic overview and discusses the theoretical and experimental concepts behind this technology. Emphasis is put on the current state-of-the-art experimental realization and several variations of FSRS that have been developed. The unique capabilities of FSRS are illustrated through a comprehensive presentation of experiments to date followed by prospects. PMID:26919612

  10. Endopeptidase-Mediated Beta Lactam Tolerance

    OpenAIRE

    Dörr, Tobias; Davis, Brigid M.; Waldor, Matthew K.

    2015-01-01

    In many bacteria, inhibition of cell wall synthesis leads to cell death and lysis. The pathways and enzymes that mediate cell lysis after exposure to cell wall-acting antibiotics (e.g. beta lactams) are incompletely understood, but the activities of enzymes that degrade the cell wall (‘autolysins’) are thought to be critical. Here, we report that Vibrio cholerae, the cholera pathogen, is tolerant to antibiotics targeting cell wall synthesis. In response to a wide variety of cell wall- acting ...

  11. Beta-Thalassaemia types in southern Sardinia.

    OpenAIRE

    Cao, A; Furbetta, M; Ximenes, A; Angius, A; Rosatelli, C; Tuveri, T; Scalas, M T; Falchi, A M; Maccioni, L; Melis, M A; R. Galanello

    1981-01-01

    In this study the prevalence of the different beta-thalassaemia types in southern Sardinia was investigated by cellulose acetate and agar gel electrophoresis or globin chain synthesis analysis on column chromatography or both in (1) all the patients (347) presenting with thalassaemia major or intermedia at our haematology service from 1976 to 1979, and (2) a group of 82 patients with transfusion-dependent thalassaemia major randomly chosen from 236 under our care. Apart from six subjects with...

  12. Risk adjusted equity valuation and accounting betas

    OpenAIRE

    Pope, P F; Wang, P.

    2000-01-01

    In this paper we develop a general equity valuation model where abnormal earnings, back value, the discount factor and interest rates evolve stochastically. Focusing on the dynamics of abnormal earnings, we demonstrate the back value, abnormal earnings, "other information" and two risk adjustment terms are sufficient for valuation when pricing kernel risk is attributable to a single market factor. The risk adjustment terms depend on accounting betas reflecting the covariances between abnormal...

  13. Tables of double beta decay data

    International Nuclear Information System (INIS)

    A compilation of experimental data on double beta decay is presented. The tables contain the most stringent known experimental limits or positive results of 2β transitions of 69 natural nuclides to ground and excited states of daughter nuclei for different channels (2β-; 2β+; εβ+; 2ε) and modes (0ν; 2ν; 0νM) of decay. (authors). 189 refs., 9 figs., 3 tabs

  14. SPL and Beta Beams to the Frejus

    CERN Document Server

    Mezzetto, M

    2005-01-01

    Physics potential of a conventional neutrino beam generated by the 2.2 GeV, 4MW, Superconducting Proton Linac and of a Beta Beam fired to a gigantic water Ccaronerenkov detector hosted below Frejus, 130 km away from CERN, are briefly summarized. theta/sub 13/ sensitivity could be improved by up to 3 orders of magnitude with respect to the present experimental limit and a first sensitive search for leptonic CP violation could be performed.

  15. Precision mass measurements utilizing beta endpoints

    CERN Document Server

    Moltz, D M; Kern, B D; Noma, H; Ritchie, B G; Toth, K S

    1981-01-01

    A technique for precise determination of beta endpoints with an intrinsic germanium detector has been developed. The energy calibration is derived from gamma -ray photopeak measurements. This analysis procedure has been checked with a /sup 27/Si source produced in a (p, n) reaction on a /sup 27/Al target and subsequently applied to mass separated samples of /sup 76/Rb, /sup 77/Rb and /sup 78/Rb. Results indicate errors <50 keV are obtainable. (29 refs).

  16. Beta Beams for Precision Measurements of Neutrino Oscillation Parameters

    CERN Document Server

    Wildner, E; Hansen, C; De Melo Mendonca, T; Stora, T; Damjanovic, S; Payet, J; Chancé, A; Zorin, V; Izotov, I; Rasin, S; Sidorov, A; Skalyga, V; De Angelis, G; Prete, G; Cinausero, M; Kravchuk, V; Gramegna, F; Marchi, T; Collazuol, G; Mezzetto, M; Delbar, T; Loiselet, M; Keutgen, T; Mitrofanov, S; Burt, G; Dexter, A; Lamy, T; Latrasse, L; Marie-Jeanne, M; Sortais, P; Thuillier, T; Debray, F; Trophime, C; Hass, M; Hirsh, T; Berkovits, D; Stahl, A; Vardaci, E; Di Nitto, A; Brondi, A; La Rana, G; Moro, R; De Rosa, G; Palladino, V

    2012-01-01

    Neutrino oscillations have implications for the Standard Model of particle physics. The CERN Beta Beam has outstanding capabilities to contribute to precision measurements of the parameters governing neutrino oscillations. The FP7 collaboration EUROnu (2008-2012) is a design study that will review three facilities (Super-Beams, Beta Beams and Neutrino Factories) and perform a cost assessment that, coupled with the physics performance, will give means to the European research authorities to make decisions on future European neutrino oscillation facilities. ”Beta Beams” produce collimated pure electron (anti)neutrinos by accelerating beta active ions to high energies and having them decay in a storage ring. Using existing machines and infrastructure is an advantage for the cost evaluation; however, this choice is also constraining the Beta Beams. Recent work to make the Beta Beam facility a solid option will be described: production of Beta Beam isotopes, the 60 GHz pulsed ECR source development, integratio...

  17. Reinvestigation of the beta-decay of {sup 110}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.C.; Dendooven, P.; Hankonen, S.; Huikari, J.; Jokinen, A.; Kolhinen, V.S.; Lhersonneau, G.; Nieminen, A.; Peraejaervi, K.; Rinta-Antila, S.; Aeystoe, J. [Department of Physics, University of Jyvaeskylae, FIN-40351, Jyvaeskylae (Finland)

    2004-01-01

    The beta-decay of the neutron-rich nucleus {sup 110}Mo, separated by the IGISOL on-line mass separator from other fission products, has been investigated by using beta-gamma and gamma-gamma coincidence techniques. The decay scheme of {sup 110}Mo has been revised, including 3 new excited states and 7 new {gamma} transitions in {sup 110}Tc. The {beta}-feedings were measured and log ft values and B(GT) values were deduced based on a Q{sub {beta}}-value from systematics. Three excited 1{sup +} states in {sup 110}Tc fed by spin-flip allowed-unhindered beta transitions were identified. The deduced beta-decay strengths are compared with the Gamow-Teller strength distribution obtained from a macroscopic-microscopic calculation. The role of the asymptotic quantum numbers in the context of the allowed beta-decay is discussed. (orig.)

  18. Laser ionization mass spectroscopy

    Science.gov (United States)

    Bernardez, Luis J., III; Siekhaus, W. J.

    1989-10-01

    Laser Ionization Mass Spectroscopy (LIMS) is a simple technique with several advantages and disadvantages over standard mass spectroscopy techniques. The LIMS technique uses a laser to vaporize a small portion of a sample. The vapor from the sample consists of a mixture of charged and neutral atoms or fragments. Using electrostatic grids, the ions (positive or negative) are given a known amount of kinetic energy and sent down a time-of-flight tube. The time it takes the ions to travel down the flight tube is recorded. Knowing the ions' energy, the length of the flight tube, and the time it takes the ions to travel that distance, the masses of the ions can be calculated. The instrument used is a LIMA 3 made by Cambridge Mass Spectrometry. It has a Quanta Ray DCR-11 Nd:YAG laser, which was frequency-quadrupled to 266 nm. The laser spot size is typically between 2 and 5 microns in diameter and the pulse width is between 5 and 10 nanoseconds. The energy of the laser is continually variable between 0.1 and 3.0 millijoules. The detector is a 17-stage venetian-blind multiplier made by Thorn EMI. The analysis is carried out under vacuum, usually between 10(exp -8) and 10(exp -9) Torr. The LIMA 3 has several useful features such as: a He-Ne pilot laser used to target the Nd:YAG laser; a microscope (which is used to view the sample through the laser optics); and a precision sample stage for accurate sample alignment.

  19. Broadband terahertz spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Wenhui Fan

    2011-01-01

    1.Introduction Spanning the frequency range between the infrared (IR) radiation and microwaves,terahertz (THz) waves are,also known as T-rays,T-lux,or simply called THz,assigned to cover the electromagnetic spectrum typically from 100 GHz (1011 Hz) to 10 THz (1013 Hz),namely,from 3 mm to 30 μm in wavelength,although slightly different definitions have been quoted by different authors.For a very long time,THz region is an almost unexplored field due to its rather unique location in the electromagnetic spectrum.Well-known techniques in optical or microwave region can not be directly employed in the THz range because optical wavelengths are too short and microwave wavelengths are too long compared to THz wavelengths.%An overview of the major techniques to generate and detect THz radiation so far, especially the major approaches to generate and detect coherent ultra-short THz pulses using ultra-short pulsed laser, has been presented. And also, this paper, in particularly, focuses on broadband THz spectroscopy and addresses on a number of issues relevant to generation and detection of broadband pulsed THz radiation as well as broadband time-domain THz spectroscopy (THz-TDS) with the help of ultra-short pulsed laser. The time-domain waveforms of coherent ultra-short THz pulses from photoconductive antenna excited by femtosecond laser with different pulse durations and their corresponding Fourier-transformed spectra have been obtained via the numerical simulation of ultrafast dynamics between femtosecond laser pulse and photoconductive material. The origins of fringes modulated on the top of broadband amplitude spectrum, which is measured by electric-optic detector based on thin nonlinear crystal and extracted by fast Fourier transformation, have been analyzed and the major solutions to get rid of these fringes are discussed.

  20. Simulation in double-beta decay experiments

    International Nuclear Information System (INIS)

    A detailed understanding of background radiation sources is a key to interpretation and enhanced sensitivity of double-beta decay experiments. Improvement of several techniques will be discussed. An implementation of the EGS4 code was developed to improve the accuracy of detector simulations, in particular for a 100Mo double-beta decay experiment. The efficiency modification due to the angular dependence of the 539 keV - 590 keV gamma-ray coincidence was successfully determined. The success of the 100Mo effort led to the modeling of uranium-thorium backgrounds found in an electroformed copper shield built for a 76Ge experiment. The large copper mass increased our sensitivity to contaminants present in copper produced this way, and led to changes in our cryostat electroforming technique. The original goal was the determination of the 210Pb content of the 450 year old lead shield previously used in 71Ge two-neutrino double-beta decay measurements. The results pertaining to low background materials and fabrication techniques will also be discussed

  1. Beta decay properties from a statistical model

    International Nuclear Information System (INIS)

    The present work assumes that any intrinsic structure in the nuclei involved is not important. Only spin, parity, and energy are considered. Quantities such as half-life, average beta energy, or average gamma energy can be obtained by integrals over the beta strength function weighted by kinematic and other factors. The beta strength function is proportional to the level density multiplied by a reduced transition probability. Delayed neutron emission is calculated by assuming that the daughter is a compound nucleus which then statistically decays as in the Hauser-Feshbach approach. Using the ENDF/B-V fission product file which contains 877 nuclei, energy-dependent reduced transition probabilities were found for allowed 0+ → 1+ transitions (50 cases) and for other allowed transitions (over 600 cases), corresponding to log ft values of 4.3 and 5.6 respectively. No dependence on either transition energy or on mass was found. A reduced transition probability corresponding to log ft of 7.1 was used for first forbidden transitions. Some results are presented and discussed

  2. Non-invasive in vivo determination of the carotenoids beta-carotene and lycopene concentrations in the human skin using the Raman spectroscopic method

    International Nuclear Information System (INIS)

    Resonance Raman spectroscopy was used as a fast and non-invasive optical method of measuring the absolute concentrations of beta-carotene and lycopene in living human skin. Beta-carotene and lycopene have different absorption values at 488 and 514.5 nm and, consequently, the Raman lines for beta-carotene and lycopene have different scattering efficiencies at 488 and 514.5 nm excitations. These differences were used for the determination of the concentrations of beta-carotene and lycopene. Using multiline Ar+ laser excitation, clearly distinguishable carotenoid Raman spectra can be obtained which are superimposed on a large fluorescence background. The Raman signals are characterized by two prominent Stokes lines at 1160 and 1525 cm-1, which have nearly identical relative intensities. Both substances were detected simultaneously. The Raman spectra are obtained rapidly, i.e. within about 10 s, and the required laser light exposure level is well within safety standards. The disturbance of the measurements by non-homogeneous skin pigmentation was avoided by using a relatively large measuring area of 35 mm2. It was shown that beta-carotene and lycopene distribution in human skin strongly depends upon the skin region studied and drastically changed inter-individually. Skin beta-carotene and lycopene concentrations are lower in smokers than in non-smokers and higher in the vegetarian group

  3. Non-invasive in vivo determination of the carotenoids beta-carotene and lycopene concentrations in the human skin using the Raman spectroscopic method

    Energy Technology Data Exchange (ETDEWEB)

    Darvin, M E [Center of Experimental and Applied Cutaneous Physiology (CCP), Department of Dermatology, Charite University Hospital, Berlin (Germany); Gersonde, I [Institute of Medical Physics and Laser Medicine, Charite University Hospital, Berlin (Germany); Meinke, M [Institute of Medical Physics and Laser Medicine, Charite University Hospital, Berlin (Germany); Sterry, W [Center of Experimental and Applied Cutaneous Physiology (CCP), Department of Dermatology, Charite University Hospital, Berlin (Germany); Lademann, J [Center of Experimental and Applied Cutaneous Physiology (CCP), Department of Dermatology, Charite University Hospital, Berlin (Germany)

    2005-08-07

    Resonance Raman spectroscopy was used as a fast and non-invasive optical method of measuring the absolute concentrations of beta-carotene and lycopene in living human skin. Beta-carotene and lycopene have different absorption values at 488 and 514.5 nm and, consequently, the Raman lines for beta-carotene and lycopene have different scattering efficiencies at 488 and 514.5 nm excitations. These differences were used for the determination of the concentrations of beta-carotene and lycopene. Using multiline Ar{sup +} laser excitation, clearly distinguishable carotenoid Raman spectra can be obtained which are superimposed on a large fluorescence background. The Raman signals are characterized by two prominent Stokes lines at 1160 and 1525 cm{sup -1}, which have nearly identical relative intensities. Both substances were detected simultaneously. The Raman spectra are obtained rapidly, i.e. within about 10 s, and the required laser light exposure level is well within safety standards. The disturbance of the measurements by non-homogeneous skin pigmentation was avoided by using a relatively large measuring area of 35 mm{sup 2}. It was shown that beta-carotene and lycopene distribution in human skin strongly depends upon the skin region studied and drastically changed inter-individually. Skin beta-carotene and lycopene concentrations are lower in smokers than in non-smokers and higher in the vegetarian group.

  4. Beta-sitosterol from psyllium seed husk (Plantago ovata Forsk) restores gap junctional intercellular communication in Ha-ras transfected rat liver cells.

    Science.gov (United States)

    Nakamura, Yasushi; Yoshikawa, Noriko; Hiroki, Ikumi; Sato, Kenji; Ohtsuki, Kozo; Chang, Chia-Cheng; Upham, Brad L; Trosko, James E

    2005-01-01

    We purified compounds from the husks of psyllium seeds (Plantago ovata Forsk; desert Indian wheat), beginning with an ethanol extraction then followed by HP-20 and silica gel chromatography, which restored gap junctional intercellular communication (GJIC) in v-Ha-ras transfected rat liver epithelial WB-F344 cell line (WB-Ha-ras). GJIC was assessed by a scrape loading dye transfer assay. The active compound was identified as beta-sitosterol based on gas chromatography retention times and electron ionization mass spectroscopy (EI-MS) spectrum of authentic beta-sitosterol. Authentic beta-sitosterol restored GJIC in the tumorigenic WB-Ha-ras GJIC-deficient cells at a dose of 2.4 microM. In addition, a similar phytosterol, stigmasterol, also restored GJIC, albeit at a lower activity. beta-sitosterol and stigmasterol increased the level of connexin43 protein (Cx43) and restored phosphorylation of Cx43 to levels similar to the parental nontransfected cell line. We concluded that the restoration of intercellular communication in the GJIC-deficient, tumorigenic WB-Ha-ras cell line by the ethanol soluble fraction of psyllium seed husks is largely due to the presence of the phytosterol, beta-sitosterol. We discuss implications for dietary modulation of cancer by beta-sitosterol. PMID:15860444

  5. The light meson spectroscopy program

    Directory of Open Access Journals (Sweden)

    Smith Elton S.

    2014-06-01

    Full Text Available Recent discoveries of a number of unexpected new charmomium-like meson states at the BaBar and Belle B-factories have demonstrated how little is still known about meson spectroscopy. In this talk we will review recent highlights of the light quark spectroscopy from collider and fixed target experiments.

  6. Scanning Probe Microscopy and Spectroscopy

    Science.gov (United States)

    Wiesendanger, Roland

    1994-09-01

    Preface; List of acronyms; Introduction; Part I. Experimental Methods and Theoretical Background of Scanning Probe Microscopy and Spectroscopy: 1. Scanning tunnelling microscopy; 2. Scanning force microscopy; 3. Related scanning probe techniques; Part II. Applications of Scanning Probe Microscopy and Spectroscopy: 4. Condensed matter physics; 5. Chemistry; 6. Organic materials; 7. Metrology and standards; 8. Nanotechnology; References; Index.

  7. Ultrabroadband spectroscopy for security applications

    DEFF Research Database (Denmark)

    Engelbrecht, Sunniva; Berge, Luc; Skupin, Stefan;

    2015-01-01

    Ultrabroadband spectroscopy is a promising novel approach to overcome two major hurdles which have so far limited the application of THz spectroscopy for security applications: the increased bandwidth enables to record several characteristic spectroscopic features and the technique allows...... evaluation of the technique for defense and civil security applications....

  8. Diffusion measurements by Raman spectroscopy

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Shapiro, Alexander; Berg, Rolf W.;

    Poster "Diffusion measurements by Raman spectroscopy", See poster at http://www.kemi.dtu.dk/~ajo/rolf/petroday2004.ppt......Poster "Diffusion measurements by Raman spectroscopy", See poster at http://www.kemi.dtu.dk/~ajo/rolf/petroday2004.ppt...

  9. The light meson spectroscopy program

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Elton S. [JLAB

    2014-06-01

    Recent discoveries of a number of unexpected new charmomium-like meson states at the BaBar and Belle B-factories have demonstrated how little is still known about meson spectroscopy. In this talk we will review recent highlights of the light quark spectroscopy from collider and fixed target experiments.

  10. Effects of calcium impurity on phase relationship, ionic conductivity and microstructure of Na$^{+}$-$\\beta/beta"$-alumina solid electrolyte

    Indian Academy of Sciences (India)

    SUNG-TAE LEE; DAE-HAN LEE; SANG-MIN LEE; SANG-SOO HAN; SANG-HYUNG LEE; SUNG-KI LIM

    2016-06-01

    Ca-doped Na$^{+}$-$\\beta/beta"$-alumina was synthesized using a solid-state reaction. The changes in the properties of Na$^{+}$-$\\beta/beta"$-alumina resulting from the presence of Ca impurity were studied. Ca (0–5 wt%) was added to the respective samples, which were then sintered. The specimens were characterized using X-ray diffraction, scanningelectron microscopy, densimetry and impedance analysis. In the sintered specimens, the $\\beta"$-alumina phase fraction decreased as Ca content increased, whereas the relative sintered density increased. The surface morphology of Cadoped Na$^{+}$-$\\beta/beta"$-alumina specimens showed a Ca-rich layer, which was the main cause of increase in the specificresistance.

  11. Raman Spectroscopy for Clinical Oncology

    Directory of Open Access Journals (Sweden)

    Michael B. Fenn

    2011-01-01

    Full Text Available Cancer is one of the leading causes of death throughout the world. Advancements in early and improved diagnosis could help prevent a significant number of these deaths. Raman spectroscopy is a vibrational spectroscopic technique which has received considerable attention recently with regards to applications in clinical oncology. Raman spectroscopy has the potential not only to improve diagnosis of cancer but also to advance the treatment of cancer. A number of studies have investigated Raman spectroscopy for its potential to improve diagnosis and treatment of a wide variety of cancers. In this paper the most recent advances in dispersive Raman spectroscopy, which have demonstrated promising leads to real world application for clinical oncology are reviewed. The application of Raman spectroscopy to breast, brain, skin, cervical, gastrointestinal, oral, and lung cancers is reviewed as well as a special focus on the data analysis techniques, which have been employed in the studies.

  12. A Novel Dimeric Inhibitor Targeting Beta2GPI in Beta2GPI/Antibody Complexes Implicated in Antiphospholipid Syndrome

    Energy Technology Data Exchange (ETDEWEB)

    A Kolyada; C Lee; A De Biasio; N Beglova

    2011-12-31

    {beta}2GPI is a major antigen for autoantibodies associated with antiphospholipid syndrome (APS), an autoimmune disease characterized by thrombosis and recurrent pregnancy loss. Only the dimeric form of {beta}2GPI generated by anti-{beta}2GPI antibodies is pathologically important, in contrast to monomeric {beta}2GPI which is abundant in plasma. We created a dimeric inhibitor, A1-A1, to selectively target {beta}2GPI in {beta}2GPI/antibody complexes. To make this inhibitor, we isolated the first ligand-binding module from ApoER2 (A1) and connected two A1 modules with a flexible linker. A1-A1 interferes with two pathologically important interactions in APS, the binding of {beta}2GPI/antibody complexes with anionic phospholipids and ApoER2. We compared the efficiency of A1-A1 to monomeric A1 for inhibition of the binding of {beta}2GPI/antibody complexes to anionic phospholipids. We tested the inhibition of {beta}2GPI present in human serum, {beta}2GPI purified from human plasma and the individual domain V of {beta}2GPI. We demonstrated that when {beta}2GPI/antibody complexes are formed, A1-A1 is much more effective than A1 in inhibition of the binding of {beta}2GPI to cardiolipin, regardless of the source of {beta}2GPI. Similarly, A1-A1 strongly inhibits the binding of dimerized domain V of {beta}2GPI to cardiolipin compared to the monomeric A1 inhibitor. In the absence of anti-{beta}2GPI antibodies, both A1-A1 and A1 only weakly inhibit the binding of pathologically inactive monomeric {beta}2GPI to cardiolipin. Our results suggest that the approach of using a dimeric inhibitor to block {beta}2GPI in the pathological multivalent {beta}2GPI/antibody complexes holds significant promise. The novel inhibitor A1-A1 may be a starting point in the development of an effective therapeutic for antiphospholipid syndrome.

  13. The beta strength function structure in \\beta + decay of lutecium, thulium and cesium isotopes

    CERN Document Server

    Alkhazov, G D; Naumov, Yu V; Orlov, S Yu; Vitman, V D

    1981-01-01

    The spectra of total gamma -absorption in the decays of some lutetium, thulium and cesium isotopes have been measured. The probabilities for level population in the decay of the isotopes have been determined. The deduced beta strength functions reveal pronounced structure. Calculations of the strength functions using the Saxon-Woods potential and the residual Gamow-Teller interaction are presented. It is shown that in beta /sup +/ decay of light thulium and cesium isotopes the strength function comprises more than 70% of the Gamow-Teller excitations with mu /sub tau /=+1. This result is the first direct observation of the Gamov-Teller resonance in beta /sup +/ decay of nuclei with T/sub z/>0. (21 refs).

  14. Beta-decay rate and beta-delayed neutron emission probability of improved gross theory

    Science.gov (United States)

    Koura, Hiroyuki

    2014-09-01

    A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for unmeasured nuclei are adopted from the KTUY nuclear mass formula, which is based on the spherical-basis method. Considering the properties of the integrated Fermi function, we can roughly categorized energy region of excited-state of a daughter nucleus into three regions: a highly-excited energy region, which fully affect a delayed neutron probability, a middle energy region, which is estimated to contribute the decay heat, and a region neighboring the ground-state, which determines the beta-decay rate. Some results will be given in the presentation. A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for

  15. Operando fuel cell spectroscopy

    Science.gov (United States)

    Kendrick, Ian Michael

    The active state of a catalyst only exists during catalysis (1) provided the motivation for developing operando spectroscopic techniques. A polymer electrolyte membrane fuel cell (PEMFC) was designed to interface with commercially available instruments for acquisition of infrared spectra of the catalytic surface of the membrane electrode assembly (MEA) during normal operation. This technique has provided insight of the complex processes occurring at the electrode surface. Nafion, the solid electrolyte used in most modern-day polymer electrolyte membrane fuel cells (PEMFC), serves many purposes in fuel cell operation. However, there is little known of the interface between Nafion and the electrode surface. Previous studies of complex Stark tuning curves of carbon monoxide on the surface of a platinum electrode were attributed the co-adsorption of bisulfite ions originating from the 0.5M H2SO4 electrolyte used in the study(2). Similar tuning curves obtained on a fuel cell MEA despite the absence of supplemental electrolytes suggest the adsorption of Nafion onto platinum (3). The correlation of spectra obtained using attenuated total reflectance spectroscopy (ATR) and polarization modulated IR reflection-absorption spectroscopy (PM-IRRAS) to a theoretical spectrum generated using density functional theory (DFT) lead to development of a model of Nafion and platinum interaction which identified participation of the SO3- and CF3 groups in Nafion adsorption. The use of ethanol as a fuel stream in proton exchange membrane fuel cells provides a promising alternative to methanol. Relative to methanol, ethanol has a greater energy density, lower toxicity and can be made from the fermentation of biomass(4). Operando IR spectroscopy was used to study the oxidation pathway of ethanol and Stark tuning behavior of carbon monoxide on Pt, Ru, and PtRu electrodes. Potential dependent products such as acetaldehyde, acetic acid and carbon monoxide are identified as well as previously

  16. In vitro proliferation of adult human beta-cells.

    Directory of Open Access Journals (Sweden)

    Sabine Rutti

    Full Text Available A decrease in functional beta-cell mass is a key feature of type 2 diabetes. Glucagon-like peptide 1 (GLP-1 analogues induce proliferation of rodent beta-cells. However, the proliferative capacity of human beta-cells and its modulation by GLP-1 analogues remain to be fully investigated. We therefore sought to quantify adult human beta-cell proliferation in vitro and whether this is affected by the GLP-1 analogue liraglutide.Human islets from 7 adult cadaveric organ donors were dispersed into single cells. Beta-cells were purified by FACS. Non-sorted cells and the beta-cell enriched ("beta-cells" population were plated on extracellular matrix from rat (804G and human bladder carcinoma cells (HTB9 or bovine corneal endothelial ECM (BCEC. Cells were maintained in culture+/-liraglutide for 4 days in the presence of BrdU.Rare human beta-cell proliferation could be observed either in the purified beta-cell population (0.051±0.020%; 22 beta-cells proliferating out of 84'283 beta-cells counted or in the non-sorted cell population (0.055±0.011%; 104 proliferating beta-cells out of 232'826 beta-cells counted, independently of the matrix or the culture conditions. Liraglutide increased human beta-cell proliferation on BCEC in the non-sorted cell population (0.082±0.034% proliferating beta-cells vs. 0.017±0.008% in control, p<0.05.These results indicate that adult human beta-cell proliferation can occur in vitro but remains an extremely rare event with these donors and particular culture conditions. Liraglutide increases beta-cell proliferation only in the non-sorted cell population and only on BCEC. However, it cannot be excluded that human beta-cells may proliferate to a greater extent in situ in response to natural stimuli.

  17. Study of {sup 193}Os beta{sup -} decay; Estudo do decaimento beta{sup -} do {sup 193}Os

    Energy Technology Data Exchange (ETDEWEB)

    Zahn, Guilherme Soares

    2006-07-01

    In this work, the excited levels of {sup 193}Ir populated by the beta{sup -} decay of {sup 193}Os (T{sub 1/2} {approx} 30h) were investigated. For that purpose, {approx} 5 mg samples of 99%-enriched {sup 192}Os were irradiated under a thermal neutron flux of {approx} 10{sup 12} s{sup -1} and then analysed both using single gamma spectroscopy and a 4-detector multi parametric acquisition facility, which provided data for both a gamma gamma coincidence analysis and a directional angular correlation gamma gamma ({theta} ) study. From these data, 28 transitions were added to this decay scheme, 11 of which were previously known from nuclear reactions and 17 observed for the first time. Eight excited levels were also added to the decay scheme, 3 of which were known from nuclear reaction studies - the remaining 5 are suggested for the first time. Moreover, it was possible to confirm suspicions found in reference that the levels at 848.93 keV and 849.093 keV are indeed the same; it was also possible to confirm the existence of an excited level at 806.9 keV, which had been inferred, but not experimentally confirmed in beta decay studies to date. The angular correlation analysis allowed for the definition of the spin of the excited level at 874 keV as 5/2{sup +;} moreover, the results showed a 79% probability that the spin of the 1078 keV level is 5/2/'-, and also restricted the spin possibilities for the new excited level at 960 keV to two values (1/2 or 3/2). It was also possible to measure the multipolarity mixing ratio ({delta}{sub Ln+1}/L{sub n}) for 43 transitions - 19 of them for the first time and most of the others with a better precision than previously known. Finally, an attempt was made to understand the low-lying levels structure for this nucleus using a theoretical model, which reproduced the ground state and the two lowest-lying excited levels in {sup 193}Ir. (author)

  18. Improved drug delivery properties of PVDF membranes functionalized with beta-cyclodextrin--application to guided tissue regeneration in periodontology.

    Science.gov (United States)

    Boschin, F; Blanchemain, N; Bria, M; Delcourt-Debruyne, E; Morcellet, M; Hildebrand, H F; Martel, B

    2006-10-01

    The purpose of this study was to develop a membrane for guided tissue regeneration applicable in periodontology that could release antimicrobial agent during the healing period. Our strategy consisted to graft beta-cyclodextrin (beta-CD), a molecule that is known to form inclusion complexes with a large variety of drugs, onto PVDF membranes. Grafting occurred by using citric acid that provoked a crosslinking reaction of beta-CD, and the resulting polymer was imprisoned into the porous structure of the PVDF membrane. The reaction produced a weight increase of the membrane, the range of which depended on the temperature and on the time of curing applied in the process. The biological behavior of the membranes evaluated by proliferation and vitality tests showed good proliferation and improved activity of L132 epithelial cells on the raw and on the grafted membranes. Doxycyclin (DOX) and chlorhexidine (CHX) were used as antimicrobial agents. Their inclusion into the beta-CD cavity in aqueous solutions was confirmed by NMR spectroscopy. After the impregnation of the membranes with DOX and CHX, their release was studied in vitro in batch type experiments and measured by UV spectrophotometry. Low amounts of DOX and CHX were delivered from the raw membranes within the first few hours of tests. Grafted membranes, however, delivered DOX and CHX in larger quantities within 24 h and 10 days respectively. PMID:16758457

  19. Thymosin beta 4 and thymosin beta 10 expression in hepatocellular carcinoma

    Directory of Open Access Journals (Sweden)

    W. Theunissen

    2014-03-01

    Full Text Available Thymosin beta 4 (Tβ4 and thymosin beta 10 (Tβ10 are two members of the beta-thymosin family involved in many cellular processes such as cellular motility, angiogenesis, inflammation, cell survival and wound healing. Recently, a role for beta-thymosins has been proposed in the process of carcinogenesis as both peptides were detected in several types of cancer. The aim of the present study was to investigate the expression pattern of Tβ4 and Tβ10 in hepatocellular carcinoma (HCC. To this end, the expression pattern of both peptides was analyzed in liver samples obtained from 23 subjects diagnosed with HCC. Routinely formalin-fixed and paraffin-embedded liver samples were immunostained by indirect immunohistochemistry with polyclonal antibodies to Tβ4 and Tβ10. Immunoreactivity for Tβ4 and Tβ10 was detected in the liver parenchyma of the surrounding tumor area. Both peptides showed an increase in granular reactivity from the periportal to the periterminal hepatocytes. Regarding HCC, Tβ4 reactivity was detected in 7/23 cases (30% and Tβ10 reactivity in 22/23 (97% cases analyzed, adding HCC to human cancers that express these beta-thymosins. Intriguing finding was seen looking at the reactivity of both peptides in tumor cells infiltrating the surrounding liver. Where Tβ10 showed a strong homogeneous expression, was Tβ4 completely absent in cells undergoing stromal invasion. The current study shows expression of both beta-thymosins in HCC with marked differences in their degree of expression and frequency of immunoreactivity. The higher incidence of Tβ10 expression and its higher reactivity in tumor cells involved in stromal invasion indicate a possible major role for Tβ10 in HCC progression.

  20. Systematic Risk on Istanbul Stock Exchange: Traditional Beta Coefficient Versus Downside Beta Coefficient

    OpenAIRE

    Gülfen TUNA; Vedat Ender TUNA

    2013-01-01

    The aim of this study is to test the validity of Downside Capital Asset Pricing Model (D-CAPM) on the ISE. At the same time, the explanatory power of CAPM's traditional beta and D-CAPM's downside beta on the changes in the average return values are examined comparatively. In this context, the monthly data for seventy three stocks that are continuously traded on the ISE for the period 1991-2009 is used. Regression analysis is applied in this study. The research results have shown that D-CAPM i...