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Sample records for 11b magic angle

  1. High resolution 11B NMR of magnesium diboride using cryogenic magic angle spinning

    NASA Astrophysics Data System (ADS)

    Beckett, Peter; Denning, Mark S.; Heinmaa, Ivo; Dimri, Mukesh C.; Young, Edward A.; Stern, Raivo; Carravetta, Marina

    2012-09-01

    Static and magic-angle spinning 11B nuclear magnetic resonance (NMR) data at 4.7 T and 8.5 T have been obtained under cryogenic conditions on a diluted sample of magnesium diboride powder in the normal and superconducting state. The data provide accurate information on the magnetic shift and longitudinal relaxation time down to a temperature of 8 K, with a resolution improvement over the entire temperature range. The onset of superconductivity is unaffected by the sample rotation, as revealed by a steep variation of the magnetic shift just below the critical temperature.

  2. 'Magic Angle Precession'

    SciTech Connect

    Binder, Bernd

    2008-01-21

    An advanced and exact geometric description of nonlinear precession dynamics modeling very accurately natural and artificial couplings showing Lorentz symmetry is derived. In the linear description it is usually ignored that the geometric phase of relativistic motion couples back to the orbital motion providing for a non-linear recursive precession dynamics. The high coupling strength in the nonlinear case is found to be a gravitomagnetic charge proportional to the precession angle and angular velocity generated by geometric phases, which are induced by high-speed relativistic rotations and are relevant to propulsion technologies but also to basic interactions. In the quantum range some magic precession angles indicating strong coupling in a phase-locked chaotic system are identified, emerging from a discrete time dynamical system known as the cosine map showing bifurcations at special precession angles relevant to heavy nuclei stability. The 'Magic Angle Precession' (MAP) dynamics can be simulated and visualized by cones rolling in or on each other, where the apex and precession angles are indexed by spin, charge or precession quantum numbers, and corresponding magic angles. The most extreme relativistic warping and twisting effect is given by the Dirac spinor half spin constellation with 'Hyperdiamond' MAP, which resembles quark confinement.

  3. New magic angle bumps and magic translation bumps

    SciTech Connect

    Seeman, J.

    1983-10-28

    SLC beams of opposite charge can be transversely deflected in the same direction by RF fields in the accelerating cavities caused by girder tilts, coupler-asymmetries, or manufacturing errors. A symmetric deflection can be corrected by a magic angle bump if the deflection is located adjacent to one of the linac quadrupoles. However, if the deflection is located between quadrupoles, two magic angle bumps or a magic angle bump and a magic translation bump are needed for the correction. Several examples of translation bumps are included. A new magic angle bump is also presented which is longitudinally compressed and has significantly reduced particle excursions. Finally, if new correctors are added midway along the girders so that the number of correctors are doubled, then the longitudinal extent and the maximum particle excursion of these new magic bumps can be further reduced.

  4. MAGIC SHIMMING: gradient shimming with magic angle sample spinning.

    PubMed

    Nishiyama, Yusuke; Tsutsumi, Yu; Utsumi, Hiroaki

    2012-03-01

    A simple method to automatically shim NMR samples spinning at the magic angle is introduced based on the gradient shimming approach. The field inhomogeneity along the spinning axis is measured and automatically corrected. The combination of a normal magic angle spinning (MAS) probe, a conventional homospoil gradient, and a set of properly chosen standard room-temperature shims are used to perform the gradient shimming of samples spinning at the magic angle. The resulting (13)C NMR adamantane linewidth is less than 1 Hz (0.0078 ppm at 11.7 T). PMID:22370722

  5. MAGIC SHIMMING: Gradient shimming with magic angle sample spinning

    NASA Astrophysics Data System (ADS)

    Nishiyama, Yusuke; Tsutsumi, Yu; Utsumi, Hiroaki

    2012-03-01

    A simple method to automatically shim NMR samples spinning at the magic angle is introduced based on the gradient shimming approach. The field inhomogeneity along the spinning axis is measured and automatically corrected. The combination of a normal magic angle spinning (MAS) probe, a conventional homospoil gradient, and a set of properly chosen standard room-temperature shims are used to perform the gradient shimming of samples spinning at the magic angle. The resulting 13C NMR adamantane linewidth is less than 1 Hz (0.0078 ppm at 11.7 T).

  6. The magic angle: a solved mystery.

    PubMed

    Jouffrey, B; Schattschneider, P; Hébert, C

    2004-12-01

    We resolve the long-standing mysterious discrepancy between the experimental magic angle in EELS--approximately 2theta(E)--and the quantum mechanical prediction of approximately 4theta(E). A relativistic approach surpassing the usually applied kinematic correction yields a magic angle close to the experimental value. The reason is that the relativistic correction of the inelastic scattering cross section in anisotropic systems is significantly higher than in isotropic ones. PMID:15556701

  7. Magic Angle Spinning NMR of Viruses

    PubMed Central

    Quinn, Caitlin; Lu, Manman; Suiter, Christopher L.; Hou, Guangjin; Zhang, Huilan; Polenova, Tatyana

    2015-01-01

    Viruses, relatively simple pathogens, are able to replicate in many living organisms and to adapt to various environments. Conventional atomic-resolution structural biology techniques, X-ray crystallography and solution NMR spectroscopy provided abundant information on the structures of individual proteins and nucleic acids comprising viruses; however, viral assemblies are not amenable to analysis by these techniques because of their large size, insolubility, and inherent lack of long-range order. In this article, we review the recent advances in magic angle spinning NMR spectroscopy that enabled atomic-resolution analysis of structure and dynamics of large viral systems and give examples of several exciting case studies. PMID:25919197

  8. Broadband "Infinite-Speed" Magic-Angle Spinning NMR Spectroscopy

    SciTech Connect

    Hu, Yan-Yan; Levin, E.M; Schmidt-Rohr, Klaus

    2009-06-02

    High-resolution magic-angle spinning NMR of high-Z spin- 1/2 nuclei such as {sup 125}Te, {sup 207}Pb, {sup 119}Sn, {sup 113}Cd, and {sup 195}Pt is often hampered by large (>1000 ppm) chemical-shift anisotropies, which result in strong spinning sidebands that can obscure the centerbands of interest. In various tellurides with applications as thermoelectrics and as phase-change materials for data storage, even 22-kHz magic-angle spinning cannot resolve the center- and sidebands broadened by chemical-shift dispersion, which precludes peak identification or quantification. For sideband suppression over the necessary wide spectral range (up to 200 kHz), radio frequency pulse sequences with few, short pulses are required. We have identified Gan's two-dimensional magic-angle-turning (MAT) experiment with five 90{sup o} pulses as a promising broadband technique for obtaining spectra without sidebands. We have adapted it to broad spectra and fast magic-angle spinning by accounting for long pulses (comparable to the dwell time in t{sub 1}) and short rotation periods. Spectral distortions are small and residual sidebands negligible even for spectra with signals covering a range of 1.5 {gamma}B{sub 1}, due to a favorable disposition of the narrow ranges containing the signals of interest in the spectral plane. The method is demonstrated on various technologically interesting tellurides with spectra spanning up to 170 kHz, at 22 kHz MAS.

  9. Magic-angle-spinning NMR studies of zeolite SAPO-5

    NASA Astrophysics Data System (ADS)

    Freude, D.; Ernst, H.; Hunger, M.; Pfeifer, H.; Jahn, E.

    1988-01-01

    SAPO-5 was synthesized using triethylamine as template. Magic-angle-spinning (MAS) NMR of 1H, 27Al, 29Si and 31P was used to study the silicon incorporation into the framework and the nature of the Brønsted sites. 1H MAS NMR shows two types of bridging hydroxyl groups. 29Si MAS NMR indicates that silicon substitutes mostly for phosphorus and that there is a small amount of crystalline SiO 2 in the zeolite powder.

  10. NMR in rotating magnetic fields: Magic angle field spinning

    SciTech Connect

    Sakellariou, D.; Meriles, C.; Martin, R.; Pines, A.

    2004-09-10

    Magic angle sample spinning has been one of the cornerstones in high-resolution solid state NMR. Spinning frequencies nowadays have increased by at least one order of magnitude over the ones used in the first experiments and the technique has gained tremendous popularity. It is currently a routine procedure in solid-state NMR, high-resolution liquid-state NMR and solid-state MRI. The technique enhances the spectral resolution by averaging away rank 2 anisotropic spin interactions thereby producing isotropic-like spectra with resolved chemical shifts and scalar couplings. Andrew proposed that it should be possible to induce similar effects in a static sample if the direction of the magnetic field is varied, e.g., magic-angle rotation of the B0 field (B0-MAS) and this has been recently demonstrated using electromagnetic field rotation. Here we discuss on the possibilities to perform field rotation using alternative hardware, together with spectroscopic methods to recover isotropic resolution even in cases where the field is not rotating at the magic angle. Extension to higher magnetic fields would be beneficial in situations where the physical manipulation of the sample is inconvenient or impossible. Such situations occur often in materials or biomedical samples where ''ex-situ'' NMR spectroscopy and imaging analysis is needed.

  11. HYDROGEN AND DEUTERIUM NMR OF SOLIDS BY MAGIC ANGLE SPINNING

    SciTech Connect

    Eckman, R.R.

    1982-10-01

    The nuclear magnetic resonance of solids has long been characterized by very large spectral broadening which arises from internuclear dipole-dipole coupling or the nuclear electric quadrupole interaction. These couplings can obscure the smaller chemical shift interaction and make that information unavailable. Two important and difficult cases are that of hydrogen and deuterium. For example, the homonuclear dipolar broadening, HD, for hydrogen is usually several tens of kilohertz. For deuterium, HD is relatively small; however, the quadrupole interaction causes a broadening which can be hundreds of kilohertz in polycrystalline or amorphous solids. The development of cross polarization, heteronuclear radiofrequency decoupling, and coherent averaging of nuclear spin interactions has provided measurement of chemical shift tensors in solids. Recently, double quantum NMR and double quantum decoupling have led to measurement of deuterium and proton chemical shift tensors, respectively. A general problem of these experiments is the overlapping of the tensor powder pattern spectra of magnetically distinct sites which cannot be resolved. In this work, high resolution NMR of hydrogen and deuterium in solids is demonstrated. For both nuclei, the resonances are narrowed to obtain liquid-like isotropic spectra by high frequency rotation of the sample about an axis inclined at the magic angle, {beta}{sub m} = Arccos(3{sup -1/2}), with respect to the direction of the external magnetic field. Two approaches have been developed for each nucleus. For deuterium, the powder spectra were narrowed by over three orders of magnitude by magic angle rotation with precise control of {beta}. A second approach was the observation of deuterium double quantum transitions under magic angle rotation. For hydrogen, magic angle rotation alone could be applied to obtain the isotropic spectrum when H{sub D} was small. This often occurs naturally when the nuclei are semi-dilute or involved in internal

  12. Methods for magnetic resonance analysis using magic angle technique

    DOEpatents

    Hu, Jian Zhi; Wind, Robert A.; Minard, Kevin R.; Majors, Paul D.

    2011-11-22

    Methods of performing a magnetic resonance analysis of a biological object are disclosed that include placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. In particular embodiments the method includes pulsing the radio frequency to provide at least two of a spatially selective read pulse, a spatially selective phase pulse, and a spatially selective storage pulse. Further disclosed methods provide pulse sequences that provide extended imaging capabilities, such as chemical shift imaging or multiple-voxel data acquisition.

  13. High-resolution NMR of anisotropic samples with spinning away from the magic angle

    SciTech Connect

    Sakellariou, Dimitris; Meriles, Carlos A.; Martin, Rachel W.; Pines, Alexander

    2003-03-31

    High-resolution NMR of samples in the solid state is typically performed under mechanical sample spinning around an axis that makes an angle, called the magic angle, of 54.7 degrees with the static magnetic field. There are many cases in which geometrical and engineering constraints prevent spinning at this specific angle. Implementations of in-situ and ex-situ magic angle field spinning might be extremely demanding because of the power requirements or an inconvenient sample size or geometry. Here we present a methodology based on switched angle spinning between two angles, none of which is the magic angle, which provide both isotropic and anisotropic information. Using this method, named Projected Magic Angle Spinning, we were able to obtain resolved isotropic chemical shifts in spinning samples where the broadening is mostly inhomogeneous.

  14. Ultrashort TE T1ρ magic angle imaging.

    PubMed

    Du, Jiang; Statum, Sheronda; Znamirowski, Richard; Bydder, Graeme M; Chung, Christine B

    2013-03-01

    An ultrashort TE T(1)ρ sequence was used to measure T(1) ρ of the goat posterior cruciate ligament (n = 1) and human Achilles tendon specimens (n = 6) at a series of angles relative to the B(0) field and spin-lock field strengths to investigate the contribution of dipole-dipole interaction to T(1)ρ relaxation. Preliminary results showed a significant magic angle effect. T(1)ρ of the posterior cruciate ligament increased from 6.9 ± 1.3 ms at 0° to 36 ± 5 ms at 55° and then gradually reduced to 12 ± 3 ms at 90°. Mean T(1)ρ of the Achilles tendon increased from 5.5 ± 2.2 ms at 0° to 40 ± 5 ms at 55°. T(1)ρ dispersion study showed a significant T(1)ρ increase from 2.3 ± 0.9 ms to 11 ± 3 ms at 0° as the spin-lock field strength increased from 150 Hz to 1 kHz, and from 30 ± 3 ms to 42 ± 4 ms at 55° as the spin-lock field strength increased from 100 to 500 Hz. These results suggest that dipolar interaction is the dominant T(1)ρ relaxation mechanism in tendons and ligaments. PMID:22539354

  15. High-pressure magic angle spinning nuclear magnetic resonance

    SciTech Connect

    Hoyt, David W.; Turcu, Romulus V. F.; Sears, Jesse A.; Rosso, Kevin M.; Burton, Sarah D.; Felmy, Andrew R.; Hu, Jian Zhi

    2011-10-01

    A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure rotor loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges associated with development of a reusable high-pressure MAS rotor are addressed in part by modifying standard ceramics for the rotor sleeve by abrading the internal surface at both ends of the cylinder. In this way, not only is the advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other removable plastic sealing mechanisms/components and O-rings can be mounted to create the desired high-pressure seal. Using this strategy, sealed internal pressures exceeding 150 bars have been achieved and sustained under ambient external pressure with minimal loss of pressure for 72 h. Finally, as an application example, in situ13C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg2SiO4) reacted with supercritical CO2 and H2O at 150 bar and 50 °C are reported, with relevance to geological sequestration of carbon dioxide.

  16. High-pressure magic angle spinning nuclear magnetic resonance.

    PubMed

    Hoyt, David W; Turcu, Romulus V F; Sears, Jesse A; Rosso, Kevin M; Burton, Sarah D; Felmy, Andrew R; Hu, Jian Zhi

    2011-10-01

    A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure rotor loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges associated with development of a reusable high-pressure MAS rotor are addressed in part by modifying standard ceramics for the rotor sleeve by abrading the internal surface at both ends of the cylinder. In this way, not only is the advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other removable plastic sealing mechanisms/components and O-rings can be mounted to create the desired high-pressure seal. Using this strategy, sealed internal pressures exceeding 150 bars have been achieved and sustained under ambient external pressure with minimal loss of pressure for 72 h. As an application example, in situ(13)C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg(2)SiO(4)) reacted with supercritical CO(2) and H(2)O at 150 bar and 50°C are reported, with relevance to geological sequestration of carbon dioxide. PMID:21862372

  17. High-pressure magic angle spinning nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Hoyt, David W.; Turcu, Romulus V. F.; Sears, Jesse A.; Rosso, Kevin M.; Burton, Sarah D.; Felmy, Andrew R.; Hu, Jian Zhi

    2011-10-01

    A high-pressure magic angle spinning (MAS) NMR capability, consisting of a reusable high-pressure MAS rotor, a high-pressure rotor loading/reaction chamber for in situ sealing and re-opening of the high-pressure MAS rotor, and a MAS probe with a localized RF coil for background signal suppression, is reported. The unusual technical challenges associated with development of a reusable high-pressure MAS rotor are addressed in part by modifying standard ceramics for the rotor sleeve by abrading the internal surface at both ends of the cylinder. In this way, not only is the advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other removable plastic sealing mechanisms/components and O-rings can be mounted to create the desired high-pressure seal. Using this strategy, sealed internal pressures exceeding 150 bars have been achieved and sustained under ambient external pressure with minimal loss of pressure for 72 h. As an application example, in situ13C MAS NMR studies of mineral carbonation reaction intermediates and final products of forsterite (Mg 2SiO 4) reacted with supercritical CO 2 and H 2O at 150 bar and 50 °C are reported, with relevance to geological sequestration of carbon dioxide.

  18. Solid effect in magic angle spinning dynamic nuclear polarization

    NASA Astrophysics Data System (ADS)

    Corzilius, Björn; Smith, Albert A.; Griffin, Robert G.

    2012-08-01

    For over five decades, the solid effect (SE) has been heavily utilized as a mechanism for performing dynamic nuclear polarization (DNP). Nevertheless, it has not found widespread application in contemporary, high magnetic field DNP experiments because SE enhancements display an ω _0 ^{ - 2} field dependence. In particular, for nominally forbidden zero and double quantum SE transitions to be partially allowed, it is necessary for mixing of adjacent nuclear spin states to occur, and this leads to the observed field dependence. However, recently we have improved our instrumentation and report here an enhancement of ɛ = 91 obtained with the organic radical trityl (OX063) in magic angle spinning experiments performed at 5 T and 80 K. This is a factor of 6-7 higher than previous values in the literature under similar conditions. Because the solid effect depends strongly on the microwave field strength, we attribute this large enhancement to larger microwave field strengths inside the sample volume, achieved with more efficient coupling of the gyrotron to the sample chamber. In addition, we develop a theoretical model to explain the dependence of the buildup rate of enhanced nuclear polarization and the steady-state enhancement on the microwave power. Buildup times and enhancements were measured as a function of 1H concentration for both trityl and Gd-DOTA. Comparison of the results indicates that for trityl the initial polarization step is the slower, rate-determining step. However, for Gd-DOTA the spread of nuclear polarization via homonuclear 1H spin diffusion is rate-limiting. Finally, we discuss the applicability of the solid effect at fields > 5 T and the requirements to address the unfavorable field dependence of the solid effect.

  19. Solid effect in magic angle spinning dynamic nuclear polarization

    PubMed Central

    Corzilius, Björn; Smith, Albert A.; Griffin, Robert G.

    2012-01-01

    For over five decades, the solid effect (SE) has been heavily utilized as a mechanism for performing dynamic nuclear polarization (DNP). Nevertheless, it has not found widespread application in contemporary, high magnetic field DNP experiments because SE enhancements display an \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\begin{equation*}\\omega _0 ^{ - 2}\\end{equation*} \\end{document}ω0−2 field dependence. In particular, for nominally forbidden zero and double quantum SE transitions to be partially allowed, it is necessary for mixing of adjacent nuclear spin states to occur, and this leads to the observed field dependence. However, recently we have improved our instrumentation and report here an enhancement of ɛ = 91 obtained with the organic radical trityl (OX063) in magic angle spinning experiments performed at 5 T and 80 K. This is a factor of 6-7 higher than previous values in the literature under similar conditions. Because the solid effect depends strongly on the microwave field strength, we attribute this large enhancement to larger microwave field strengths inside the sample volume, achieved with more efficient coupling of the gyrotron to the sample chamber. In addition, we develop a theoretical model to explain the dependence of the buildup rate of enhanced nuclear polarization and the steady-state enhancement on the microwave power. Buildup times and enhancements were measured as a function of 1H concentration for both trityl and Gd-DOTA. Comparison of the results indicates that for trityl the initial polarization step is the slower, rate-determining step. However, for Gd-DOTA the spread of nuclear polarization via homonuclear 1H spin diffusion is rate-limiting. Finally, we discuss the applicability of the solid effect at fields > 5 T and the requirements

  20. Solid effect in magic angle spinning dynamic nuclear polarization.

    PubMed

    Corzilius, Björn; Smith, Albert A; Griffin, Robert G

    2012-08-01

    For over five decades, the solid effect (SE) has been heavily utilized as a mechanism for performing dynamic nuclear polarization (DNP). Nevertheless, it has not found widespread application in contemporary, high magnetic field DNP experiments because SE enhancements display an ω(0)(-2) field dependence. In particular, for nominally forbidden zero and double quantum SE transitions to be partially allowed, it is necessary for mixing of adjacent nuclear spin states to occur, and this leads to the observed field dependence. However, recently we have improved our instrumentation and report here an enhancement of ε = 91 obtained with the organic radical trityl (OX063) in magic angle spinning experiments performed at 5 T and 80 K. This is a factor of 6-7 higher than previous values in the literature under similar conditions. Because the solid effect depends strongly on the microwave field strength, we attribute this large enhancement to larger microwave field strengths inside the sample volume, achieved with more efficient coupling of the gyrotron to the sample chamber. In addition, we develop a theoretical model to explain the dependence of the buildup rate of enhanced nuclear polarization and the steady-state enhancement on the microwave power. Buildup times and enhancements were measured as a function of (1)H concentration for both trityl and Gd-DOTA. Comparison of the results indicates that for trityl the initial polarization step is the slower, rate-determining step. However, for Gd-DOTA the spread of nuclear polarization via homonuclear (1)H spin diffusion is rate-limiting. Finally, we discuss the applicability of the solid effect at fields > 5 T and the requirements to address the unfavorable field dependence of the solid effect. PMID:22894339

  1. High-resolution NMR spectroscopy of biological tissues usingprojected Magic Angle Spinning

    SciTech Connect

    Martin, Rachel W.; Jachmann, Rebecca C.; Sakellariou, Dimitris; Nielsen, Ulla Gro; Pines, Alexander

    2005-01-27

    High-resolution NMR spectra of materials subject toanisotropic broadening are usually obtained by rotating the sample aboutthe magic angle, which is 54.7 degrees to the static magnetic field. Inprojected Magic Angle Spinning (p-MAS), the sample is spun about twoangles, neither of which is the magic angle. This provides a method ofobtaining isotropic spectra while spinning at shallow angles. The p-MASexperiment may be used in situations where spinning the sample at themagic angle is not possible due to geometric or other constraints,allowing the choice of spinning angle to be determined by factors such asthe shape of the sample, rather than by the spin physics. The applicationof this technique to bovine tissue samples is demonstrated as a proof ofprinciple for future biological or medical applications.

  2. Hall Plateaus at magic angles in ultraquantum Bismuth

    NASA Astrophysics Data System (ADS)

    Benoît, Fauqué.

    2009-03-01

    The behaviour of a three-dimensional electron gas in the presence of a magnetic field strong enough to put all carriers in the first Landau level (i.e. beyond the quantum limit) is a longstanding question of theoretical condensed matter physics [1]. This issue has been recently explored by two high-field experiments on elemental semi-metal Bismuth. In a first study of transport coefficients (which are dominated by hole-like carriers), the Nernst coefficient presented three unexpected maxima that are concomitant with quasi-plateaux in the Hall coefficient [2]. In a second series of experiments, torque magnetometry (which mainly probes the three Dirac valley electron pockets) detected a field-induced phase transition [3]. The full understanding of the electron and hole behaviours above the quantum limit of pure Bi is therefore still under debate. In this talk, we will present our measurement of the Hall resistivity and torque magnetometry with magnetic field up to 31 T and rotating in the trigonal-bisectrix plane [4]. The Hall response is dominated by the hole pockets according to its sign as well as the period and the angular dependence of its quantum oscillations. In the vicinity of the quantum limit, it presents additional anomalies which are the fingerprints of the electron pockets. We found that for particular orientations of the magnetic field (namely ``magic angles''), the Hall response becomes field-independent within the experimental resolution around 20T. This drastic dependence of the plateaux on the field orientation provides strong constraints for theoretical scenarios. [4pt] [1] Bertrand I. Halperin, Japanese Journal of Applied Physics, 26, Supplement 26-3 (1987).[0pt] [2] Kamran Behnia, Luis Balicas, Yakov Kopelevich, Science, 317, 1729 (2008).[0pt] [3] Lu Li, J. G. Checkelsky, Y. S. Hor, C. Uher, A. F. Hebard, R. J. Cava, and N. P. Ong , Science, 321, 5888 (2008).[0pt] [4] Benoît Fauqu'e, Luis Balicas, Ilya Sheikin, Jean Paul Issi and Kamran Behnia

  3. Theoretical aspects of Magic Angle Spinning - Dynamic Nuclear Polarization

    NASA Astrophysics Data System (ADS)

    Mentink-Vigier, Frederic; Akbey, Ümit; Oschkinat, Hartmut; Vega, Shimon; Feintuch, Akiva

    2015-09-01

    Magic Angle Spinning (MAS) combined with Dynamic Nuclear Polarization (DNP) has been proven in recent years to be a very powerful method for increasing solid-state NMR signals. Since the advent of biradicals such as TOTAPOL to increase the nuclear polarization new classes of radicals, with larger molecular weight and/or different spin properties have been developed. These have led to unprecedented signal gain, with varying results for different experimental parameters, in particular the microwave irradiation strength, the static field, and the spinning frequency. Recently it has been demonstrated that sample spinning imposes DNP enhancement processes that differ from the active DNP mechanism in static samples as upon sample spinning the DNP enhancements are the results of energy level anticrossings occurring periodically during each rotor cycle. In this work we present experimental results with regards to the MAS frequency dependence of the DNP enhancement profiles of four nitroxide-based radicals at two different sets of temperature, 110 and 160 K. In fact, different magnitudes of reduction in enhancement are observed with increasing spinning frequency. Our simulation code for calculating MAS-DNP powder enhancements of small model spin systems has been improved to extend our studies of the influence of the interaction and relaxation parameters on powder enhancements. To achieve a better understanding we simulated the spin dynamics of a single three-spin system {ea -eb - n } during its steady state rotor periods and used the Landau-Zener formula to characterize the influence of the different anti-crossings on the polarizations of the system and their necessary action for reaching steady state conditions together with spin relaxation processes. Based on these model calculations we demonstrate that the maximum steady state nuclear polarization cannot become larger than the maximum polarization difference between the two electrons during the steady state rotor cycle

  4. Theoretical aspects of Magic Angle Spinning - Dynamic Nuclear Polarization.

    PubMed

    Mentink-Vigier, Frederic; Akbey, Ümit; Oschkinat, Hartmut; Vega, Shimon; Feintuch, Akiva

    2015-09-01

    Magic Angle Spinning (MAS) combined with Dynamic Nuclear Polarization (DNP) has been proven in recent years to be a very powerful method for increasing solid-state NMR signals. Since the advent of biradicals such as TOTAPOL to increase the nuclear polarization new classes of radicals, with larger molecular weight and/or different spin properties have been developed. These have led to unprecedented signal gain, with varying results for different experimental parameters, in particular the microwave irradiation strength, the static field, and the spinning frequency. Recently it has been demonstrated that sample spinning imposes DNP enhancement processes that differ from the active DNP mechanism in static samples as upon sample spinning the DNP enhancements are the results of energy level anticrossings occurring periodically during each rotor cycle. In this work we present experimental results with regards to the MAS frequency dependence of the DNP enhancement profiles of four nitroxide-based radicals at two different sets of temperature, 110 and 160K. In fact, different magnitudes of reduction in enhancement are observed with increasing spinning frequency. Our simulation code for calculating MAS-DNP powder enhancements of small model spin systems has been improved to extend our studies of the influence of the interaction and relaxation parameters on powder enhancements. To achieve a better understanding we simulated the spin dynamics of a single three-spin system {ea-eb-n} during its steady state rotor periods and used the Landau-Zener formula to characterize the influence of the different anti-crossings on the polarizations of the system and their necessary action for reaching steady state conditions together with spin relaxation processes. Based on these model calculations we demonstrate that the maximum steady state nuclear polarization cannot become larger than the maximum polarization difference between the two electrons during the steady state rotor cycle. This

  5. An efficient amplification pulse sequence for measuring chemical shift anisotropy under fast magic-angle spinning.

    PubMed

    Hung, Ivan; Gan, Zhehong

    2011-12-01

    A two-dimensional experiment for measuring chemical shift anisotropy (CSA) under fast magic-angle spinning (MAS) is presented. The chemical shift anisotropy evolution is amplified by a sequence of π-pulses that repetitively interrupt MAS averaging. The amplification generates spinning sideband manifolds in the indirect dimension separated by the isotropic shift along the direct dimension. The basic unit of the pulse sequence is designed based on the magic-angle turning experiment and can be concatenated for larger amplification factors. PMID:21962909

  6. Simple cylindrical magic-angle spinner for NMR studies in electromagnets

    NASA Astrophysics Data System (ADS)

    Mai, Michael T.; Ribeiro, Anthony; Jardetzky, Oleg

    A novel cylindrical magic-angle spinner for use in electromagnet systems is described. It features radial and thrust air bearings and easily constructed rotors of relatively large sample volume (˜0.7 cm 3) assembled into a removable spinner/coil Teflon housing. The design allows stable spinning speeds in the range 0.3 to 2.4 kHz with excellent rotor-to-rotor magic-angle resettabilities. High resolution, solid-state NMR studies are illustrated with 13C NMR spectra for crystalline adamantane and a macromolecule, lysozyme.

  7. True Pathologic Abnormality versus Artifact Foot Position and Magic Angle Artifact in the Peroneal Tendons with 3T Imaging.

    PubMed

    Horn, Deena B; Meyers, Steven; Astor, William

    2015-09-01

    Magnetic resonance imaging is a commonly ordered examination by many foot and ankle surgeons for ankle pain and suspected peroneal tendon pathologic abnormalities. Magic angle artifact is one of the complexities associated with this imaging modality. Magic angle refers to the increased signal on magnetic resonance images associated with the highly organized collagen fibers in tendons and ligaments when they are orientated at a 55° angle to the main magnetic field. We present several examples from a clinical practice setting using 3T imaging illustrating a substantial reduction in magic angle artifact of the peroneal tendon in the prone plantarflexed position compared with the standard neutral (right angle) position. PMID:26429616

  8. Determination of the bond-angle distribution in vitreous B{sub 2}O{sub 3} by {sup 11}B double rotation (DOR) NMR spectroscopy

    SciTech Connect

    Hung, I.; Howes, A.P.; Parkinson, B.G.; Anupold, T.; Samoson, A.; Brown, S.P.; Harrison, P.F.; Holland, D.; Dupree, R.

    2009-09-15

    The B-O-B bond angle distributions for both ring and non-ring boron sites in vitreous B{sub 2}O{sub 3} have been determined by {sup 11}B double rotation (DOR) NMR and multiple-quantum (MQ) DOR NMR. The [B{sub 3}O{sub 6}] boroxol rings are observed to have a mean internal B-O-B angle of 120.0+-0.7 deg. with a small standard deviation, sigma{sub R}=3.2+-0.4 deg., indicating that the rings are near-perfect planar, hexagonal structures. The rings are linked predominantly by non-ring [BO{sub 3}] units, which share oxygens with the boroxol ring, with a mean B{sub ring}-O-B{sub non-ring} angle of 135.1+-0.6 deg. and sigma{sub NR}=6.7+-0.4 deg. In addition, the fraction of boron atoms, f, which reside in the boroxol rings has been measured for this sample as f=0.73+-0.01. - Graphical abstract: Connectivities and B-O-B bond angle distributions of ring and non-ring boron atoms in v-B{sub 2}O{sub 3} have been determined by {sup 11}B double rotation (DOR) NMR, multiple-quantum (MQ) DOR NMR and spin-diffusion DOR. Near-perfect planar, hexagonal [B{sub 3}O{sub 6}] boroxol rings are shown to be present. Display Omitted

  9. Sealed magic angle spinning nuclear magnetic resonance probe and process for spectroscopy of hazardous samples

    DOEpatents

    Cho, Herman M.; Washton, Nancy M.; Mueller, Karl T.; Sears, Jr., Jesse A.; Townsend, Mark R.; Ewing, James R.

    2016-06-14

    A magic-angle-spinning (MAS) nuclear magnetic resonance (NMR) probe is described that includes double containment enclosures configured to seal and contain hazardous samples for analysis. The probe is of a modular design that ensures containment of hazardous samples during sample analysis while preserving spin speeds for superior NMR performance and convenience of operation.

  10. Devices and process for high-pressure magic angle spinning nuclear magnetic resonance

    DOEpatents

    Hoyt, David W; Sears, Jr., Jesse A; Turcu, Romulus V.F.; Rosso, Kevin M; Hu, Jian Zhi

    2014-04-08

    A high-pressure magic angle spinning (MAS) rotor is detailed that includes a high-pressure sample cell that maintains high pressures exceeding 150 bar. The sample cell design minimizes pressure losses due to penetration over an extended period of time.

  11. Hydrogen and deuterium NMR of solids by magic-angle spinning

    SciTech Connect

    Eckman, R.R.

    1982-10-01

    The nuclear magnetic resonance of solids has long been characterized by very large specral broadening which arises from internuclear dipole-dipole coupling or the nuclear electric quadrupole interaction. These couplings can obscure the smaller chemical shift interaction and make that information unavailable. Two important and difficult cases are that of hydrogen and deuterium. The development of cross polarization, heteronuclear radiofrequency decoupling, and coherent averaging of nuclear spin interactions has provided measurement of chemical shift tensors in solids. Recently, double quantum NMR and double quantum decoupling have led to measurement of deuterium and proton chemical shift tensors, respectively. A general problem of these experiments is the overlapping of the tensor powder pattern spectra of magnetically distinct sites which cannot be resolved. In this work, high resolution NMR of hydrogen and deuterium in solids is demonstrated. For both nuclei, the resonances are narrowed to obtain liquid-like isotropic spectra by high frequency rotation of the sample about an axis inclined at the magic angle, ..beta../sub m/ = Arccos (3/sup -1/2/), with respect to the direction of the external magnetic field. For deuterium, the powder spectra were narrowed by over three orders of magnitude by magic angle rotation with precise control of ..beta... A second approach was the observation of deuterium double quantum transitions under magic angle rotation. For hydrogen, magic angle rotation alone could be applied to obtain the isotropic spectrum when H/sub D/ was small. This often occurs naturally when the nuclei are semi-dilute or involved in internal motion. In the general case of large H/sub D/, isotropic spectra were obtained by dilution of /sup 1/H with /sup 2/H combined with magic angle rotation. The resolution obtained represents the practical limit for proton NMR of solids.

  12. Method for high resolution magnetic resonance analysis using magic angle technique

    DOEpatents

    Wind, Robert A.; Hu, Jian Zhi

    2004-12-28

    A method of performing a magnetic resonance analysis of a biological object that includes placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. The object may be reoriented about the magic angle axis between three predetermined positions that are related to each other by 120.degree.. The main magnetic field may be rotated mechanically or electronically. Methods for magnetic resonance imaging of the object are also described.

  13. Method for high resolution magnetic resonance analysis using magic angle technique

    DOEpatents

    Wind, Robert A.; Hu, Jian Zhi

    2003-12-30

    A method of performing a magnetic resonance analysis of a biological object that includes placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. The object may be reoriented about the magic angle axis between three predetermined positions that are related to each other by 120.degree.. The main magnetic field may be rotated mechanically or electronically. Methods for magnetic resonance imaging of the object are also described.

  14. Discrete magic angle turning system, apparatus, and process for in situ magnetic resonance spectroscopy and imaging

    DOEpatents

    Hu, Jian Zhi; Sears, Jr., Jesse A.; Hoyt, David W.; Wind, Robert A.

    2009-05-19

    Described are a "Discrete Magic Angle Turning" (DMAT) system, devices, and processes that combine advantages of both magic angle turning (MAT) and magic angle hopping (MAH) suitable, e.g., for in situ magnetic resonance spectroscopy and/or imaging. In an exemplary system, device, and process, samples are rotated in a clockwise direction followed by an anticlockwise direction of exactly the same amount. Rotation proceeds through an angle that is typically greater than about 240 degrees but less than or equal to about 360 degrees at constant speed for a time applicable to the evolution dimension. Back and forth rotation can be synchronized and repeated with a special radio frequency (RF) pulse sequence to produce an isotropic-anisotropic shift 2D correlation spectrum. The design permits tubes to be inserted into the sample container without introducing plumbing interferences, further allowing control over such conditions as temperature, pressure, flow conditions, and feed compositions, thus permitting true in-situ investigations to be carried out.

  15. Excitation of multiple quantum transitions under magic angle spinning conditions: Adamantane

    NASA Astrophysics Data System (ADS)

    Meier, B. H.; Earl, William L.

    1986-11-01

    A pulse sequence designed for the excitation of multiple quantum transitions in magic angle spinning solid state NMR spectroscopy is presented. It is shown that under the action of the standard time-reversal pulse sequence, the change in the sign of the dipole coupling (which is used to generate the multiple quantum coherences) upon rotation causes the multiple quantum intensity to vanish after each rotor period. This effect is demonstrated both in calculations and in experimental 1H spectra of adamantane. A modification of the time-reversal pulse sequence, which involves switching the phase of the rf pulses every half-rotor period causes the spin part of the Hamiltonian to switch sign in synchrony with the modulation of the spacial part. This allows the creation of multiple quantum coherences in solids with magic angle spinning. The effectiveness of this pulse sequence is demonstrated through calculations and experiments.

  16. A sensitive, high resolution magic angle turning experiment for measuring chemical shift tensor principal values

    NASA Astrophysics Data System (ADS)

    Alderman, D. W.

    1998-12-01

    A sensitive, high-resolution 'FIREMAT' two-dimensional (2D) magic-angle-turning experiment is described that measures chemical shift tensor principal values in powdered solids. The spectra display spinning-sideband patterns separated by their isotropic shifts. The new method's sensitivity and high resolution in the isotropic-shift dimension result from combining the 5pi magic-angle-turning pulse sequence, an extension of the pseudo-2D sideband-suppression data rearrangement, and the TIGER protocol for processing 2D data. TPPM decoupling is used to enhance resolution. The method requires precise synchronization of the pulses and sampling to the rotor position. It is shown that the technique obtains 35 natural-abundance 13C tensors from erythromycin in 19 hours, and high quality naturalabundance 15N tensors from eight sites in potassium penicillin V in three days on a 400MHz spectrometer.

  17. Excitation of multiple quantum transitions under magic angle spinning conditions: Adamantane

    SciTech Connect

    Meier, B.H.; Earl, W.L.

    1986-11-01

    A pulse sequence designed for the excitation of multiple quantum transitions in magic angle spinning solid state NMR spectroscopy is presented. It is shown that under the action of the standard time-reversal pulse sequence, the change in the sign of the dipole coupling (which is used to generate the multiple quantum coherences) upon rotation causes the multiple quantum intensity to vanish after each rotor period. This effect is demonstrated both in calculations and in experimental /sup 1/H spectra of adamantane. A modification of the time-reversal pulse sequence, which involves switching the phase of the rf pulses every half-rotor period causes the spin part of the Hamiltonian to switch sign in synchrony with the modulation of the spacial part. This allows the creation of multiple quantum coherences in solids with magic angle spinning. The effectiveness of this pulse sequence is demonstrated through calculations and experiments.

  18. Spin-locking and cross-polarization under magic-angle spinning of uniformly labeled solids.

    PubMed

    Hung, Ivan; Gan, Zhehong

    2015-07-01

    Spin-locking and cross-polarization under magic-angle spinning are investigated for uniformly (13)C and (15)N labeled solids. In particular, the interferences from chemical shift anisotropy, and (1)H heteronuclear and (13)C homonuclear dipolar couplings are identified. The physical origin of these interferences provides guidelines for selecting the best (13)C and (15)N polarization transfer rf fields. Optimal settings for both the zero- and double-quantum cross-polarization transfer mechanisms are recommended. PMID:25965280

  19. NMR high-resolution magic angle spinning rotor design for quantification of metabolic concentrations

    NASA Astrophysics Data System (ADS)

    Holly, R.; Damyanovich, A.; Peemoeller, H.

    2006-05-01

    A new high-resolution magic angle spinning nuclear magnetic resonance technique is presented to obtain absolute metabolite concentrations of solutions. The magnetic resonance spectrum of the sample under investigation and an internal reference are acquired simultaneously, ensuring both spectra are obtained under the same experimental conditions. The robustness of the technique is demonstrated using a solution of creatine, and it is shown that the technique can obtain solution concentrations to within 7% or better.

  20. Spin-locking and cross-polarization under magic-angle spinning of uniformly labeled solids

    NASA Astrophysics Data System (ADS)

    Hung, Ivan; Gan, Zhehong

    2015-07-01

    Spin-locking and cross-polarization under magic-angle spinning are investigated for uniformly 13C and 15N labeled solids. In particular, the interferences from chemical shift anisotropy, and 1H heteronuclear and 13C homonuclear dipolar couplings are identified. The physical origin of these interferences provides guidelines for selecting the best 13C and 15N polarization transfer rf fields. Optimal settings for both the zero- and double-quantum cross-polarization transfer mechanisms are recommended.

  1. Solid-state proton multiple-quantum NMR spectroscopy with fast magic angle spinning

    NASA Astrophysics Data System (ADS)

    Geen, Helen; Titman, Jeremy J.; Gottwald, Johannes; Spiess, Hans W.

    1994-09-01

    The feasibility of multiple-quantum NMR spectroscopy with high resolution for protons in solids is explored. A new multiple-quantum excitation sequence suitable for use with fast magic angle spinning is described, and its performance is compared to that of both static and slow-spinning multiple-quantum methods. Modified sequences with scale the rate of development of the multiple-quantum coherences are also demonstrated, and two-dimensional double-quantum spectra of adamantane and polycarbonate are presented.

  2. Microfabricated inserts for magic angle coil spinning (MACS) wireless NMR spectroscopy.

    PubMed

    Badilita, Vlad; Fassbender, Birgit; Kratt, Kai; Wong, Alan; Bonhomme, Christian; Sakellariou, Dimitris; Korvink, Jan G; Wallrabe, Ulrike

    2012-01-01

    This article describes the development and testing of the first automatically microfabricated probes to be used in conjunction with the magic angle coil spinning (MACS) NMR technique. NMR spectroscopy is a versatile technique for a large range of applications, but its intrinsically low sensitivity poses significant difficulties in analyzing mass- and volume-limited samples. The combination of microfabrication technology and MACS addresses several well-known NMR issues in a concerted manner for the first time: (i) reproducible wafer-scale fabrication of the first-in-kind on-chip LC microresonator for inductive coupling of the NMR signal and reliable exploitation of MACS capabilities; (ii) improving the sensitivity and the spectral resolution by simultaneous spinning the detection microcoil together with the sample at the "magic angle" of 54.74° with respect to the direction of the magnetic field (magic angle spinning - MAS), accompanied by the wireless signal transmission between the microcoil and the primary circuit of the NMR spectrometer; (iii) given the high spinning rates (tens of kHz) involved in the MAS methodology, the microfabricated inserts exhibit a clear kinematic advantage over their previously demonstrated counterparts due to the inherent capability to produce small radius cylindrical geometries, thus tremendously reducing the mechanical stress and tearing forces on the sample. In order to demonstrate the versatility of the microfabrication technology, we have designed MACS probes for various Larmor frequencies (194, 500 and 700 MHz) testing several samples such as water, Drosophila pupae, adamantane solid and LiCl at different magic angle spinning speeds. PMID:22936994

  3. An isotropic chemical shift-chemical shift anisotropic correlation experiment using discrete magic angle turning.

    PubMed

    Hu, Jian Zhi; Sears, Jesse A; Kwak, Ja Hun; Hoyt, David W; Wang, Yong; Peden, Charles H F

    2009-05-01

    An isotropic-anisotropic shift 2D correlation spectroscopy is introduced that combines the advantages of both magic angle turning (MAT) and magic angle hopping (MAH) technologies. In this new approach, denoted DMAT for "discrete magic angle turning", the sample rotates clockwise followed by an anticlockwise rotation of exactly the same amount with each rotation less or equal than 360 degrees but greater than 240 degrees , with the rotation speed being constant only for times related to the evolution dimension. This back and forth rotation is repeated and synchronized with a special radio frequency (RF) pulse sequence to produce an isotropic-anisotropic shift 2D correlation spectrum. For any spin-interaction of rank-2 such as chemical shift anisotropy, isotropic magnetic susceptibility interaction, and residual homo-nuclear dipolar interaction in biological fluid samples, the projection along the isotropic dimension is a high resolution spectrum. Since a less than 360 degrees sample rotation is involved, the design potentially allows for in situ control over physical parameters such as pressure, flow conditions, feed compositions, and temperature so that true in situ NMR investigations can be carried out. PMID:19246221

  4. Magic-Angle-Spinning NMR Magnet Development: Field Analysis and Prototypes

    PubMed Central

    Voccio, John; Hahn, Seungyong; Park, Dong Keun; Ling, Jiayin; Kim, Youngjae; Bascuñán, Juan; Iwasa, Yukikazu

    2013-01-01

    We are currently working on a program to complete a 1.5 T/75 mm RT bore magic-angle-spinning nuclear magnetic resonance magnet. The magic-angle-spinning magnet comprises a z-axis 0.866-T solenoid and an x-axis 1.225-T dipole, each to be wound with NbTi wire and operated at 4.2 K in persistent mode. A combination of the fields creates a 1.5-T field pointed at 54.74 degrees (magic angle) from the rotation (z) axis. In the first year of this 3-year program, we have completed magnetic analysis and design of both coils. Also, using a winding machine of our own design and fabrication, we have wound several prototype dipole coils with NbTi wire. As part of this development, we have repeatedly made successful persistent NbTi-NbTi joints with this multifilamentary NbTi wire. PMID:24058275

  5. Magic angle and height quantization in nanofacets on SiC(0001) surfaces

    SciTech Connect

    Sawada, Keisuke; Iwata, Jun-Ichi; Oshiyama, Atsushi

    2014-02-03

    We report on the density-functional calculations that provide microscopic mechanism of the facet formation on the SiC (0001) surface. We first identify atom-scale structures of single-, double-, and quad-bilayer steps and find that the single-bilayer (SB) step has the lowest formation energy. We then find that the SB steps are bunched to form a nanofacet with a particular angle relative to the (0001) plane (magic facet angle) and with a discretized height along the (0001) direction (height quantization). We also clarify a microscopic reason for the self-organization of the nanofacet observed experimentally.

  6. Microfabricated Inserts for Magic Angle Coil Spinning (MACS) Wireless NMR Spectroscopy

    PubMed Central

    Badilita, Vlad; Fassbender, Birgit; Kratt, Kai; Wong, Alan; Bonhomme, Christian; Sakellariou, Dimitris; Korvink, Jan G.; Wallrabe, Ulrike

    2012-01-01

    This article describes the development and testing of the first automatically microfabricated probes to be used in conjunction with the magic angle coil spinning (MACS) NMR technique. NMR spectroscopy is a versatile technique for a large range of applications, but its intrinsically low sensitivity poses significant difficulties in analyzing mass- and volume-limited samples. The combination of microfabrication technology and MACS addresses several well-known NMR issues in a concerted manner for the first time: (i) reproducible wafer-scale fabrication of the first-in-kind on-chip LC microresonator for inductive coupling of the NMR signal and reliable exploitation of MACS capabilities; (ii) improving the sensitivity and the spectral resolution by simultaneous spinning the detection microcoil together with the sample at the “magic angle” of 54.74° with respect to the direction of the magnetic field (magic angle spinning – MAS), accompanied by the wireless signal transmission between the microcoil and the primary circuit of the NMR spectrometer; (iii) given the high spinning rates (tens of kHz) involved in the MAS methodology, the microfabricated inserts exhibit a clear kinematic advantage over their previously demonstrated counterparts due to the inherent capability to produce small radius cylindrical geometries, thus tremendously reducing the mechanical stress and tearing forces on the sample. In order to demonstrate the versatility of the microfabrication technology, we have designed MACS probes for various Larmor frequencies (194, 500 and 700 MHz) testing several samples such as water, Drosophila pupae, adamantane solid and LiCl at different magic angle spinning speeds. PMID:22936994

  7. Tethered or adsorbed supported lipid bilayers in nanotubes characterized by deuterium magic angle spinning NMR spectroscopy.

    PubMed

    Wattraint, Olivier; Warschawski, Dror E; Sarazin, Catherine

    2005-04-12

    2H solid-state NMR experiments were performed under magic angle spinning on lipid bilayers oriented into nanotubes arrays, as a new method to assess the geometrical arrangement of the lipids. Orientational information is obtained from the intensities of the spinning sidebands. The lipid bilayers are formed by fusion of small unilamellar vesicles of DMPC-d54 inside a nanoporous anodic aluminum oxide, either by direct adsorption on the support or by tethering through a streptavidin/biotin linker. The results support that the quality of the lipid bilayers alignment is clearly in favor of the tethering rather than an adsorbed strategy. PMID:15807556

  8. On the magic-angle turning and phase-adjusted spinning sidebands experiments.

    PubMed

    Hung, Ivan; Gan, Zhehong

    2010-05-01

    The underlying relation between the magic-angle turning (MAT) and phase-adjusted spinning sidebands (PASS) experiments is examined. The MAT experiment satisfies the PASS conditions for separating spinning sidebands with a non-constant total evolution time and only requires linear t(1) increments of up to one rotor period. The time-domain data of the two experiments are related by a shearing transformation. A combination of the linear evolution-time increments of MAT and simple data processing of PASS are particularly attractive for the implementation of MAT for measuring chemical shift anisotropy. PMID:20202873

  9. High-resolution magic-angle-spinning NMR spectroscopy of intact tissue.

    PubMed

    Giskeødegård, Guro F; Cao, Maria D; Bathen, Tone F

    2015-01-01

    High-resolution magic-angle-spinning (HR-MAS) NMR spectroscopy is a nondestructive technique that is used to obtain the metabolite profile of a tissue sample. This method requires minimal sample preparation. However, it is important to handle the sample with care and keep it frozen during preparation to minimize degradation. Here, we describe a typical protocol for HR-MAS analysis of intact tissue. We also include examples of typical pulse sequence programs and quantification methods that are used today. PMID:25677145

  10. The use of variable temperature and magic-angle sample spinning in studies of fulvic acids

    USGS Publications Warehouse

    Earl, W.L.; Wershaw, R. L.; Thorn, K.A.

    1987-01-01

    Intensity distortions and poor signal to noise in the cross-polarization magic-angle sample spinning NMR of fulvic acids were investigated and attributed to molecular mobility in these ostensibly "solid" materials. We have shown that inefficiencies in cross polarization can be overcome by lowering the sample temperature to about -60??C. These difficulties can be generalized to many other synthetic and natural products. The use of variable temperature and cross-polarization intensity as a function of contact time can yield valuable qualitative information which can aid in the characterization of many materials. ?? 1987.

  11. Instrumentation for solid-state dynamic nuclear polarization with magic angle spinning NMR

    NASA Astrophysics Data System (ADS)

    Rosay, Melanie; Blank, Monica; Engelke, Frank

    2016-03-01

    Advances in dynamic nuclear polarization (DNP) instrumentation and methodology have been key factors in the recent growth of solid-state DNP NMR applications. We review the current state of the art of solid-state DNP NMR instrumentation primarily based on available commercial platforms. We start with a general system overview, including options for microwave sources and DNP NMR probes, and then focus on specific developments for DNP at 100 K with magic angle spinning (MAS). Gyrotron microwave sources, passive components to transmit microwaves, the DNP MAS probe, a cooling device for low-temperature MAS, and sample preparation procedures including radicals for DNP are considered.

  12. Magic angle spinning nuclear magnetic resonance apparatus and process for high-resolution in situ investigations

    DOEpatents

    Hu, Jian Zhi; Sears, Jr., Jesse A.; Hoyt, David W.; Mehta, Hardeep S.; Peden, Charles H. F.

    2015-11-24

    A continuous-flow (CF) magic angle sample spinning (CF-MAS) NMR rotor and probe are described for investigating reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions in situ. The rotor includes a sample chamber of a flow-through design with a large sample volume that delivers a flow of reactants through a catalyst bed contained within the sample cell allowing in-situ investigations of reactants and products. Flow through the sample chamber improves diffusion of reactants and products through the catalyst. The large volume of the sample chamber enhances sensitivity permitting in situ .sup.13C CF-MAS studies at natural abundance.

  13. Instrumentation for solid-state dynamic nuclear polarization with magic angle spinning NMR.

    PubMed

    Rosay, Melanie; Blank, Monica; Engelke, Frank

    2016-03-01

    Advances in dynamic nuclear polarization (DNP) instrumentation and methodology have been key factors in the recent growth of solid-state DNP NMR applications. We review the current state of the art of solid-state DNP NMR instrumentation primarily based on available commercial platforms. We start with a general system overview, including options for microwave sources and DNP NMR probes, and then focus on specific developments for DNP at 100K with magic angle spinning (MAS). Gyrotron microwave sources, passive components to transmit microwaves, the DNP MAS probe, a cooling device for low-temperature MAS, and sample preparation procedures including radicals for DNP are considered. PMID:26920834

  14. Measurement of nuclear magnetic dipole—dipole couplings in magic angle spinning NMR

    NASA Astrophysics Data System (ADS)

    Tycko, Robert; Dabbagh, Gary

    1990-10-01

    We describe a method for measuring nuclear magnetic dipole—dipole couplings in NMR spectra of solids undergoing rapid magic angle spinning (MAS). We show in theory, simulations, and experiments that the couplings, which are averaged out by MAS alone, can be recovered by applying simple resonant radiofrequency pulse sequences in synchrony with the sample rotation. Experimental 13C dipolar powder pattern spectra of polycrystalline ( 13CH 3) 2C(OH)SO 3Na obtained in a two-dimensional experiment based on this method are presented. The method provides a means of determining internuclear distances in polycrystalline and noncrystalline solids while retaining the high resolution and sensitivity afforded by MAS.

  15. Forward-Angle Yields Of {sup 6,8}He and {sup 9}Li Isotopes in {sup 11}B(33 AMeV)+{sup 9}Be Reaction

    SciTech Connect

    Artukh, A. G.; Klygin, S. A.; Kononenko, G. A.; Teterev, Yu. G.; Sereda, Yu. M.; Vorontsov, A. N.; Erdemchimeg, B.; Kaminski, G.; Vishnevski, I. N.; Ostashko, V. V.; Pavlenko, Yu. N.; Kovtun, V. E.; Koshchiy, E. I.; Foshchan, A. G.

    2010-04-30

    Using fragment-separator COMBAS [1] in forward-angle measurements the velocity, isotopic and element distributions of products with Z<7 in {sup 11}B(33 AMeV)+{sup 9}Be reaction have been studied. The yields of {sup 6,8}He and {sup 9}Li isotopes on the {sup 9}Be thick target (332.6 mg/cm{sup 2}) as a function of momentum acceptance of fragment -separator COMBAS have been measured. The production rates per 1pmuA of the primary beam of exotic nuclei of {sup 6}He(6.9centre dot10{sup 5} pps), {sup 8}He(2centre dot10{sup 4} pps) and {sup 9}Li(4.3centre dot10 {sup 5}pps) which can be used as secondary radioactive beams of halo -like nuclei have been determined. The two-neutron halo nuclei {sup 6,8}He and {sup 9}Li are of great current interest both as very neutron-rich nuclei with a significant neutron skin and in understanding the interactions of very neutron-rich nuclei. The {sup 9}Li beam may be helpful in understanding of sub barrier fusion enhancement independent of the presence of the halo nucleons in used neutron--rich projectiles.

  16. MATPASS/CPMG: a sensitivity enhanced magic-angle spinning sideband separation experiment for disordered solids.

    PubMed

    Hung, Ivan; Edwards, Trenton; Sen, Sabyasachi; Gan, Zhehong

    2012-08-01

    A Carr-Purcell Meiboom-Gill (CPMG) sensitivity-enhanced spinning sideband separation experiment is presented. The experiment combines the idea of magic-angle turning and phase-adjusted sideband separation (MATPASS), allowing for isotropic/anisotropic chemical shift separation of disordered solids with line widths far greater than the magic-angle spinning frequency. The use of CPMG enhances the sensitivity of the wide-line spectra by an order of magnitude via multiple-echo acquisition. The MATPASS/CPMG protocol involves acquisition of time-domain data using a MAT/CPMG pulse sequence followed by f(1) shearing during data processing to arrive at the PASS representation. Such a protocol has √2 higher sensitivity than the conventional PASS method because all CPMG echo signals are used for the final PASS spectrum. Application of this method is demonstrated using a GeSe₄ glass sample with both ⁷⁷Se isotropic line widths and chemical shift anisotropy that far exceed the spinning frequency. The sideband separation allows for the measurement of chemical shift anisotropy of the disordered solids. PMID:22750637

  17. Magnetic resonance imaging of DNP enhancements in a rotor spinning at the magic angle.

    PubMed

    Perras, Frédéric A; Kobayashi, Takeshi; Pruski, Marek

    2016-03-01

    Simulations performed on model, static, samples have shown that the microwave power is non-uniformly distributed in the magic angle spinning (MAS) rotor when using conventional dynamic nuclear polarization (DNP) instrumentation. Here, we applied the stray-field magic angle spinning imaging (STRAFI-MAS) experiment to generate a spatial map of the DNP enhancements in a full rotor, which is spun at a low rate in a commercial DNP-MAS NMR system. Notably, we observed that the enhancement factors produced in the center of the rotor can be twice as large as those produced at the top of the rotor. Surprisingly, we observed that the largest enhancement factors are observed along the axis of the rotor as opposed to against its walls, which are most directly irradiated by the microwave beam. We lastly observed that the distribution of enhancement factors can be moderately improved by degassing the sample and increasing the microwave power. The inclusion of dielectric particles greatly amplifies the enhancement factors throughout the rotor. The STRAFI-MAS approach can provide useful guidance for optimizing the access of microwave power to the sample, and thereby lead to further increases in sensitivity of DNP-MAS NMR. PMID:26920838

  18. Magnetic resonance imaging of DNP enhancements in a rotor spinning at the magic angle

    DOE PAGESBeta

    Perras, Frederic A.; Kobayashi, Takeshi; Pruski, Marek

    2016-02-23

    Simulations performed on model, static, samples have shown that the microwave power is non-uniformly distributed in the magic angle spinning (MAS) rotor when using conventional dynamic nuclear polarization (DNP) instrumentation. Here, we applied the stray-field magic angle spinning imaging (STRAFI–MAS) experiment to generate a spatial map of the DNP enhancements in a full rotor, which is spun at a low rate in a commercial DNP–MAS NMR system. Notably, we observed that the enhancement factors produced in the center of the rotor can be twice as large as those produced at the top of the rotor. Surprisingly, we observed that themore » largest enhancement factors are observed along the axis of the rotor as opposed to against its walls, which are most directly irradiated by the microwave beam. We lastly observed that the distribution of enhancement factors can be moderately improved by degassing the sample and increasing the microwave power. The inclusion of dielectric particles greatly amplifies the enhancement factors throughout the rotor. Furthermore, the STRAFI–MAS approach can provide useful guidance for optimizing the access of microwave power to the sample, and thereby lead to further increases in sensitivity of DNP–MAS NMR.« less

  19. Magnetic resonance imaging of DNP enhancements in a rotor spinning at the magic angle

    NASA Astrophysics Data System (ADS)

    Perras, Frédéric A.; Kobayashi, Takeshi; Pruski, Marek

    2016-03-01

    Simulations performed on model, static, samples have shown that the microwave power is non-uniformly distributed in the magic angle spinning (MAS) rotor when using conventional dynamic nuclear polarization (DNP) instrumentation. Here, we applied the stray-field magic angle spinning imaging (STRAFI-MAS) experiment to generate a spatial map of the DNP enhancements in a full rotor, which is spun at a low rate in a commercial DNP-MAS NMR system. Notably, we observed that the enhancement factors produced in the center of the rotor can be twice as large as those produced at the top of the rotor. Surprisingly, we observed that the largest enhancement factors are observed along the axis of the rotor as opposed to against its walls, which are most directly irradiated by the microwave beam. We lastly observed that the distribution of enhancement factors can be moderately improved by degassing the sample and increasing the microwave power. The inclusion of dielectric particles greatly amplifies the enhancement factors throughout the rotor. The STRAFI-MAS approach can provide useful guidance for optimizing the access of microwave power to the sample, and thereby lead to further increases in sensitivity of DNP-MAS NMR.

  20. Advanced slow-magic angle spinning probe for magnetic resonance imaging and spectroscopy

    DOEpatents

    Wind, Robert A.; Hu, Jian Zhi; Minard, Kevin R.; Rommereim, Donald N.

    2006-01-24

    The present invention relates to a probe and processes useful for magnetic resonance imaging and spectroscopy instruments. More particularly, the invention relates to a MR probe and processes for obtaining resolution enhancements of fluid objects, including live specimens, using an ultra-slow (magic angle) spinning (MAS) of the specimen combined with a modified phase-corrected magic angle turning (PHORMAT) pulse sequence. Proton NMR spectra were measured of the torso and the top part of the belly of a female BALBc mouse in a 2T field, while spinning the animal at a speed of 1.5 Hz. Results show that even in this relatively low field with PHORMAT, an isotropic spectrum is obtained with line widths that are a factor 4.6 smaller than those obtained in a stationary mouse. Resolution of 1H NMR metabolite spectra are thus significantly enhanced. Results indicate that PHORMAT has the potential to significantly increase the utility of 1H NMR spectroscopy for in vivo biochemical, biomedical and/or medical applications involving large-sized biological objects such as mice, rats and even humans within a hospital setting. For small-sized objects, including biological objects, such as excised tissues, organs, live bacterial cells, and biofilms, use of PASS at a spinning rate of 30 Hz and above is preferred.

  1. Method for high resolution magnetic resonance analysis using magic angle technique

    DOEpatents

    Wind, Robert A.; Hu, Jian Zhi

    2003-11-25

    A method of performing a magnetic resonance analysis of a biological object that includes placing the biological object in a main magnetic field and in a radio frequency field, the main magnetic field having a static field direction; rotating the biological object at a rotational frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. According to another embodiment, the radio frequency is pulsed to provide a sequence capable of producing a spectrum that is substantially free of spinning sideband peaks.

  2. High Resolution 1H NMR Spectroscopy in Rat Liver Using Magic Angle Turning at a 1 Hz Spinning Rate

    SciTech Connect

    Hu, Jian Zhi ); Rommereim, Donald N. ); Wind, Robert A. )

    2001-12-01

    It is demonstrated that a high resolution 1H NMR spectrum of excised rat liver can be obtained using the technique of magic angle turning at a sample spinning rate of 1 Hz. A variant of the phase-corrected magic angle turning (PHORMAT) pulse sequence that includes a water suppression segment was developed for the investigation. The spectral resolution achieved with PHORMAT is approaching that obtained from a standard magic angle spinning experiment at a spinning rate of several kHz. With such ultra-slow spinning, tissue and cell damage associated with the standard MAS experiment is minimized or eliminated. The technique is potentially useful for obtaining high-resolution 1H spectra in live animals.

  3. Analysis of atomic scale chemical environments of boron in coal by 11B solid state NMR.

    PubMed

    Takahashi, Takafumi; Kashiwakura, Shunsuke; Kanehashi, Koji; Hayashi, Shunichi; Nagasaka, Tetsuya

    2011-02-01

    Atomic scale chemical environments of boron in coal has been studied by solid state NMR spectroscopy including magic angle spinning (MAS), satellite transition magic angle spinning (STMAS), and cross-polarization magic angle spinning (CPMAS). The (11)B NMR spectra can be briefly classified according to the degree of coalification. On the (11)B NMR spectra of lignite, bituminous, and sub-bituminous coals (carbon content of 70-90mass%), three sites assigned to four-coordinate boron ([4])B with small quadrupolar coupling constants (≤0.9 MHz) are observed. Two of the ([4])B sites in downfield are considered organoboron complexes with aromatic ligands, while the other in the most upper field is considered inorganic tetragonal boron (BO(4)). By contrast, on the (11)B NMR spectra of blind coal (carbon content >90mass%), the ([4])B which substitutes tetrahedral silicon of Illite is observed as a representative species. It has been considered that the organoboron is decomposed and released from the parent phase with the advance of coal maturation, and then the released boron reacts with the inorganic phase to substitute an element of inorganic minerals. Otherwise boron contained originally in inorganic minerals might remain preserved even under the high temperature condition that is generated during coalification. PMID:21175186

  4. Magic-angle spinning NMR of intact bacteriophages: Insights into the capsid, DNA and their interface

    NASA Astrophysics Data System (ADS)

    Abramov, Gili; Morag, Omry; Goldbourt, Amir

    2015-04-01

    Bacteriophages are viruses that infect bacteria. They are complex macromolecular assemblies, which are composed of multiple protein subunits that protect genomic material and deliver it to specific hosts. Various biophysical techniques have been used to characterize their structure in order to unravel phage morphogenesis. Yet, most bacteriophages are non-crystalline and have very high molecular weights, in the order of tens of MegaDaltons. Therefore, complete atomic-resolution characterization on such systems that encompass both capsid and DNA is scarce. In this perspective article we demonstrate how magic-angle spinning solid-state NMR has and is used to characterize in detail bacteriophage viruses, including filamentous and icosahedral phage. We discuss the process of sample preparation, spectral assignment of both capsid and DNA and the use of chemical shifts and dipolar couplings to probe the capsid-DNA interface, describe capsid structure and dynamics and extract structural differences between viruses.

  5. Primary processes in isolated Photosystem II reaction centres probed by magic angle transient absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Klug, David R.; Rech, Thomas; Melissa Joseph, D.; Barber, James; Durrant, James R.; Porter, George

    1995-05-01

    There is currently some disagreement regarding the dominant time constant for formation of the radical pair state P680 +Ph - in isolated photosystem two reaction centres. It has recently been suggested that this disagreement may originate, at least in part, from different polarisations of the pump and probe beams used in optical experiments. In this paper, we present data collected using a magic angle configuration of the pump and probe polarisations. We find that these data support our previous interpretation of data collected using a parallel polarisation configuration. Moreover, we present further evidence to support our conclusion that formation of the P680 +Ph - state primarily occurs with a 21 ps time constant when P680 is directly excited. A 3 ps component is also observed; this component is not associated with a large proportion of the radical pair formation. We discuss our data and interpretation in comparison with those of other groups.

  6. Rapid proton-detected NMR assignment for proteins with fast magic angle spinning.

    PubMed

    Barbet-Massin, Emeline; Pell, Andrew J; Retel, Joren S; Andreas, Loren B; Jaudzems, Kristaps; Franks, W Trent; Nieuwkoop, Andrew J; Hiller, Matthias; Higman, Victoria; Guerry, Paul; Bertarello, Andrea; Knight, Michael J; Felletti, Michele; Le Marchand, Tanguy; Kotelovica, Svetlana; Akopjana, Inara; Tars, Kaspars; Stoppini, Monica; Bellotti, Vittorio; Bolognesi, Martino; Ricagno, Stefano; Chou, James J; Griffin, Robert G; Oschkinat, Hartmut; Lesage, Anne; Emsley, Lyndon; Herrmann, Torsten; Pintacuda, Guido

    2014-09-01

    Using a set of six (1)H-detected triple-resonance NMR experiments, we establish a method for sequence-specific backbone resonance assignment of magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of 5-30 kDa proteins. The approach relies on perdeuteration, amide (2)H/(1)H exchange, high magnetic fields, and high-spinning frequencies (ωr/2π ≥ 60 kHz) and yields high-quality NMR data, enabling the use of automated analysis. The method is validated with five examples of proteins in different condensed states, including two microcrystalline proteins, a sedimented virus capsid, and two membrane-embedded systems. In comparison to contemporary (13)C/(15)N-based methods, this approach facilitates and accelerates the MAS NMR assignment process, shortening the spectral acquisition times and enabling the use of unsupervised state-of-the-art computational data analysis protocols originally developed for solution NMR. PMID:25102442

  7. Magic-angle spinning NMR of intact bacteriophages: insights into the capsid, DNA and their interface.

    PubMed

    Abramov, Gili; Morag, Omry; Goldbourt, Amir

    2015-04-01

    Bacteriophages are viruses that infect bacteria. They are complex macromolecular assemblies, which are composed of multiple protein subunits that protect genomic material and deliver it to specific hosts. Various biophysical techniques have been used to characterize their structure in order to unravel phage morphogenesis. Yet, most bacteriophages are non-crystalline and have very high molecular weights, in the order of tens of MegaDaltons. Therefore, complete atomic-resolution characterization on such systems that encompass both capsid and DNA is scarce. In this perspective article we demonstrate how magic-angle spinning solid-state NMR has and is used to characterize in detail bacteriophage viruses, including filamentous and icosahedral phage. We discuss the process of sample preparation, spectral assignment of both capsid and DNA and the use of chemical shifts and dipolar couplings to probe the capsid-DNA interface, describe capsid structure and dynamics and extract structural differences between viruses. PMID:25797007

  8. The magnetic field dependence of cross-effect dynamic nuclear polarization under magic angle spinning

    SciTech Connect

    Mance, Deni; Baldus, Marc; Gast, Peter; Huber, Martina; Ivanov, Konstantin L.

    2015-06-21

    We develop a theoretical description of Dynamic Nuclear Polarization (DNP) in solids under Magic Angle Spinning (MAS) to describe the magnetic field dependence of the DNP effect. The treatment is based on an efficient scheme for numerical solution of the Liouville-von Neumann equation, which explicitly takes into account the variation of magnetic interactions during the sample spinning. The dependence of the cross-effect MAS-DNP on various parameters, such as the hyperfine interaction, electron-electron dipolar interaction, microwave field strength, and electron spin relaxation rates, is analyzed. Electron spin relaxation rates are determined by electron paramagnetic resonance measurements, and calculations are compared to experimental data. Our results suggest that the observed nuclear magnetic resonance signal enhancements provided by MAS-DNP can be explained by discriminating between “bulk” and “core” nuclei and by taking into account the slow DNP build-up rate for the bulk nuclei.

  9. Non-Fermi-liquid magic angle effects in high magnetic fields

    NASA Astrophysics Data System (ADS)

    Lebed, A. G.

    2016-07-01

    We investigate a theoretical problem of electron-electron interactions in an inclined magnetic field in a quasi-one-dimensional (Q1D) conductor. We show that they result in strong non-Fermi-liquid corrections to a specific heat, provided that the direction of the magnetic field is far from the so-called Lebed's magic angles (LMAs). If magnetic field is directed close to one of the LMAs, the specific heat corrections become small and the Fermi-liquid picture restores. As a result, we predict Fermi-liquid-non-Fermi-liquid angular crossovers in the vicinities of the LMA directions of the field. We suggest to perform the corresponding experiment in the Q1D conductor (Per) 2Au (mnt) 2 under pressure in magnetic fields of the order of H ≃25 T .

  10. The magnetic field dependence of cross-effect dynamic nuclear polarization under magic angle spinning

    NASA Astrophysics Data System (ADS)

    Mance, Deni; Gast, Peter; Huber, Martina; Baldus, Marc; Ivanov, Konstantin L.

    2015-06-01

    We develop a theoretical description of Dynamic Nuclear Polarization (DNP) in solids under Magic Angle Spinning (MAS) to describe the magnetic field dependence of the DNP effect. The treatment is based on an efficient scheme for numerical solution of the Liouville-von Neumann equation, which explicitly takes into account the variation of magnetic interactions during the sample spinning. The dependence of the cross-effect MAS-DNP on various parameters, such as the hyperfine interaction, electron-electron dipolar interaction, microwave field strength, and electron spin relaxation rates, is analyzed. Electron spin relaxation rates are determined by electron paramagnetic resonance measurements, and calculations are compared to experimental data. Our results suggest that the observed nuclear magnetic resonance signal enhancements provided by MAS-DNP can be explained by discriminating between "bulk" and "core" nuclei and by taking into account the slow DNP build-up rate for the bulk nuclei.

  11. Efficient dipolar double quantum filtering under magic angle spinning without a 1H decoupling field

    NASA Astrophysics Data System (ADS)

    Courtney, Joseph M.; Rienstra, Chad M.

    2016-08-01

    We present a systematic study of dipolar double quantum (DQ) filtering in 13C-labeled organic solids over a range of magic-angle spinning rates, using the SPC-n recoupling sequence element with a range of n symmetry values from 3 to 11. We find that efficient recoupling can be achieved for values n ⩾ 7, provided that the 13C nutation frequency is on the order of 100 kHz or greater. The decoupling-field dependence was investigated and explicit heteronuclear decoupling interference conditions identified. The major determinant of DQ filtering efficiency is the decoupling interference between 13C and 1H fields. For 13C nutation frequencies greater than 75 kHz, optimal performance is observed without an applied 1H field. At spinning rates exceeding 20 kHz, symmetry conditions as low as n = 3 were found to perform adequately.

  12. Magic angle spinning solid-state NMR experiments for structural characterization of proteins.

    PubMed

    Shi, Lichi; Ladizhansky, Vladimir

    2012-01-01

    Solid-state nuclear magnetic resonance (SSNMR) has become a prominent method in biology and is suitable for the characterization of insoluble proteins and protein aggregates such as amyloid fibrils, membrane-lipid complexes, and precipitated proteins. Often, the initial and the most critical step is to obtain spectroscopic assignments, that is, to determine chemical shifts of individual atoms. The procedures for SSNMR spectroscopic assignments are now well established for small microcrystalline proteins, where high signal-to-noise can be obtained. The sensitivity of the experiments and spectral resolution decrease with the increasing molecular weight, which makes setting SSNMR experiments in large proteins a much more challenging and demanding procedure. Here, we describe the protocol for the most common set of 3D magic angle spinning (MAS) SSNMR experiments. While the procedures described in the text are well known to SSNMR practitioners, we hope they will be of interest to scientists interested in extending their repertoire of biophysical techniques. PMID:22760319

  13. Forensic examination of electrical tapes using high resolution magic angle spinning ¹H NMR spectroscopy.

    PubMed

    Schoenberger, Torsten; Simmross, Ulrich; Poppe, Christian

    2016-01-01

    The application of high resolution magic angle spinning (HR-MAS) (1)H NMR spectroscopy is ideally suited for the differentiation of plastics. In addition to the actual material composition, the different types of polymer architectures and tacticity provide characteristic signals in the fingerprint of the (1)H NMR spectra. The method facilitates forensic comparison, as even small amounts of insoluble but swellable plastic particles are utilized. The performance of HR-MAS NMR can be verified against other methods that were recently addressed in various articles about forensic tape comparison. In this study samples of the 90 electrical tapes already referenced by the FBI laboratory were used. The discrimination power of HR-MAS is demonstrated by the fact that more tape groups can be distinguished by NMR spectroscopy than by using the combined evaluation of several commonly used analytical techniques. An additional advantage of this robust and quick method is the very simple sample preparation. PMID:26558760

  14. Magic-angle-spinning NMR studies of acid sites in zeolite H-ZSM-5

    SciTech Connect

    Brunner, E.; Ernst, H.; Freude, D.; Froehlich, T.; Hunger, M.; Pfeifer, H. )

    1991-01-01

    {sup 1}H, {sup 13}C, {sup 27}Al, and {sup 29}Si magic-angle-spinning (MAS) NMR was used to elucidate the nature of the catalytic activity of zeolite H-ZSM-5. {sup 1}H MAS NMR of sealed samples after mild hydrothermal dealumination shows that the enhanced activity for n-hexane cracking is not due to an enhanced Bronstead acidity. The concentrations of the various OH groups and aluminous species suggest that the reason for the enhanced catalytic activity is the interaction of the n-hexane molecule with a bridging hydroxyl group and with extra-framework aluminium species, which give rise to the enhanced activity, cannot be easily removed from their positions, and are therefore immobilized by the zeolitic framework.

  15. Efficient dipolar double quantum filtering under magic angle spinning without a (1)H decoupling field.

    PubMed

    Courtney, Joseph M; Rienstra, Chad M

    2016-08-01

    We present a systematic study of dipolar double quantum (DQ) filtering in (13)C-labeled organic solids over a range of magic-angle spinning rates, using the SPC-n recoupling sequence element with a range of n symmetry values from 3 to 11. We find that efficient recoupling can be achieved for values n⩾7, provided that the (13)C nutation frequency is on the order of 100kHz or greater. The decoupling-field dependence was investigated and explicit heteronuclear decoupling interference conditions identified. The major determinant of DQ filtering efficiency is the decoupling interference between (13)C and (1)H fields. For (13)C nutation frequencies greater than 75kHz, optimal performance is observed without an applied (1)H field. At spinning rates exceeding 20kHz, symmetry conditions as low as n=3 were found to perform adequately. PMID:27314744

  16. Pulsed field gradient magic angle spinning NMR self-diffusion measurements in liquids.

    PubMed

    Viel, Stéphane; Ziarelli, Fabio; Pagès, Guilhem; Carrara, Caroline; Caldarelli, Stefano

    2008-01-01

    Several investigations have recently reported the combined use of pulsed field gradient (PFG) with magic angle spinning (MAS) for the analysis of molecular mobility in heterogeneous materials. In contrast, little attention has been devoted so far to delimiting the role of the extra force field induced by sample rotation on the significance and reliability of self-diffusivity measurements. The main purpose of this work is to examine this phenomenon by focusing on pure liquids for which its impact is expected to be largest. Specifically, we show that self-diffusion coefficients can be accurately determined by PFG MAS NMR diffusion measurements in liquids, provided that specific experimental conditions are met. First, the methodology to estimate the gradient uniformity and to properly calibrate its absolute strength is briefly reviewed and applied on a MAS probe equipped with a gradient coil aligned along the rotor spinning axis, the so-called 'magic angle gradient' coil. Second, the influence of MAS on the outcome of PFG MAS diffusion measurements in liquids is investigated for two distinct typical rotors of different active volumes, 12 and 50 microL. While the latter rotor led to totally unreliable results, especially for low viscosity compounds, the former allowed for the determination of accurate self-diffusion coefficients both for fast and slowly diffusing species. Potential implications of this work are the possibility to measure accurate self-diffusion coefficients of sample-limited mixtures or to avoid radiation damping interferences in NMR diffusion measurements. Overall, the outlined methodology should be of interest to anyone who strives to improve the reliability of MAS diffusion studies, both in homogeneous and heterogeneous media. PMID:18006344

  17. Magic Angle Spinning NMR Spectroscopy: A Versatile Technique for Structural and Dynamic Analysis of Solid-Phase Systems

    PubMed Central

    Polenova, Tatyana; Gupta, Rupal; Goldbourt, Amir

    2016-01-01

    Magic Angle Spinning (MAS) NMR spectroscopy is a powerful method for analysis of a broad range of systems, including inorganic materials, pharmaceuticals, and biomacromolecules. The recent developments in MAS NMR instrumentation and methodologies opened new vistas to atomic-level characterization of a plethora of chemical environments previously inaccessible to analysis, with unprecedented sensitivity and resolution. PMID:25794311

  18. Magic-angle sample spinning electron paramagnetic resonance--instrumentation, performance, and limitations.

    PubMed

    Hessinger, D; Bauer, C; Hubrich, M; Jeschke, G; Spiess, H W

    2000-12-01

    An electron paramagnetic resonance (EPR) setup for line narrowing experiments with fast sample spinning at variable angles between the rotation axis and the static magnetic field is described and applied in the magic-angle sample spinning (MAS) EPR experiment at X-band frequencies (9.5 GHz). Sample spinning speeds up to 17 kHz at temperatures down to 200 K can be achieved with rotors of 4-mm outer and 2.5-mm inner diameter without severe losses in microwave amplitude compared to standard pulse EPR probeheads. A phase cycle is introduced that provides pure absorption MAS EPR spectra and allows one to distinguish between positive and negative frequency offsets (pseudo-quadrature detection). Possible broadening mechanisms in MAS EPR spectra are discussed. It is demonstrated both by theory and by experiment that the MAS EPR experiment requires excitation bandwidths that are comparable to the total spectral width, since otherwise destructive interference between contributions of spins with similar resonance offsets suppresses the signal. Experimental observations on the E(1) center in gamma-irradiated silica glass and on the SO(-)(3) radical in gamma-irradiated sulfamic acid are reported. PMID:11097812

  19. Recoupling of chemical shift anisotropy by R-symmetry sequences in magic angle spinning NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Hou, Guangjin; Byeon, In-Ja L.; Ahn, Jinwoo; Gronenborn, Angela M.; Polenova, Tatyana

    2012-10-01

    13C and 15N chemical shift (CS) interaction is a sensitive probe of structure and dynamics in a wide variety of biological and inorganic systems, and in the recent years several magic angle spinning NMR approaches have emerged for residue-specific measurements of chemical shift anisotropy (CSA) tensors in uniformly and sparsely enriched proteins. All of the currently existing methods are applicable to slow and moderate magic angle spinning (MAS) regime, i.e., MAS frequencies below 20 kHz. With the advent of fast and ultrafast MAS probes capable of spinning frequencies of 40-100 kHz, and with the superior resolution and sensitivity attained at such high frequencies, development of CSA recoupling techniques working under such conditions is necessary. In this work, we present a family of R-symmetry based pulse sequences for recoupling of 13C/15N CSA interactions that work well in both natural abundance and isotopically enriched systems. We demonstrate that efficient recoupling of either first-rank (σ1) or second-rank (σ2) spatial components of CSA interaction is attained with appropriately chosen γ-encoded RNnv symmetry sequences. The advantage of these γ-encoded RNnv-symmetry based CSA (RNCSA) recoupling schemes is that they are suitable for CSA recoupling under a wide range of MAS frequencies, including fast MAS regime. Comprehensive analysis of the recoupling properties of these RNnv symmetry sequences reveals that the σ1-CSA recoupling symmetry sequences exhibit large scaling factors; however, the partial homonuclear dipolar Hamiltonian components are symmetry allowed, which makes this family of sequences suitable for CSA measurements in systems with weak homonuclear dipolar interactions. On the other hand, the γ-encoded symmetry sequences for σ2-CSA recoupling have smaller scaling factors but they efficiently suppress the homonuclear dipole-dipole interactions. Therefore, the latter family of sequences is applicable for measurements of CSA parameters in

  20. Quantitative neuropathology by high resolution magic angle spinning proton magnetic resonance spectroscopy

    PubMed Central

    Cheng, L. L.; Ma, M. J.; Becerra, L.; Ptak, T.; Tracey, I.; Lackner, A.; González, R. G.

    1997-01-01

    We describe a method that directly relates tissue neuropathological analysis to medical imaging. Presently, only indirect and often tenuous relationships are made between imaging (such as MRI or x-ray computed tomography) and neuropathology. We present a biochemistry-based, quantitative neuropathological method that can help to precisely quantify information provided by in vivo proton magnetic resonance spectroscopy (1HMRS), an emerging medical imaging technique. This method, high resolution magic angle spinning (HRMAS) 1HMRS, is rapid and requires only small amounts of unprocessed samples. Unlike chemical extraction or other forms of tissue processing, this method analyzes tissue directly, thus minimizing artifacts. We demonstrate the utility of this method by assessing neuronal damage using multiple tissue samples from differently affected brain regions in a case of Pick disease, a human neurodegenerative disorder. Among different regions, we found an excellent correlation between neuronal loss shown by traditional neurohistopathology and decrease of the neuronal marker N-acetylaspartate measured by HRMAS 1HMRS. This result demonstrates for the first time, to our knowledge, a direct, quantitative link between a decrease in N-acetylaspartate and neuronal loss in a human neurodegenerative disease. As a quantitative method, HRMAS 1HMRS has potential applications in experimental and clinical neuropathologic investigations. It should also provide a rational basis for the interpretation of in vivo 1HMRS studies of human neurological disorders. PMID:9177231

  1. NMR longitudinal relaxation enhancement in metal halides by heteronuclear polarization exchange during magic-angle spinning.

    PubMed

    Shmyreva, Anna A; Safdari, Majid; Furó, István; Dvinskikh, Sergey V

    2016-06-14

    Orders of magnitude decrease of (207)Pb and (199)Hg NMR longitudinal relaxation times T1 upon magic-angle-spinning (MAS) are observed and systematically investigated in solid lead and mercury halides MeX2 (Me = Pb, Hg and X = Cl, Br, I). In lead(ii) halides, the most dramatic decrease of T1 relative to that in a static sample is in PbI2, while it is smaller but still significant in PbBr2, and not detectable in PbCl2. The effect is magnetic-field dependent but independent of the spinning speed in the range 200-15 000 Hz. The observed relaxation enhancement is explained by laboratory-frame heteronuclear polarization exchange due to crossing between energy levels of spin-1/2 metal nuclei and adjacent quadrupolar-spin halogen nuclei. The enhancement effect is also present in lead-containing organometal halide perovskites. Our results demonstrate that in affected samples, it is the relaxation data recorded under non-spinning conditions that characterize the local properties at the metal sites. A practical advantage of fast relaxation at slow MAS is that spectral shapes with orientational chemical shift anisotropy information well retained can be acquired within a shorter experimental time. PMID:27306000

  2. High-resolution magic angle spinning 1H MRS in prostate cancer.

    PubMed

    Decelle, Emily A; Cheng, Leo L

    2014-01-01

    Prostate cancer (PCa) is the most frequently diagnosed malignancy in men worldwide, largely as a result of the increased use of the annual serum prostate-specific antigen (PSA) screening test for detection. PSA screening has saved lives, but it has also resulted in the overtreatment of many patients with PCa because of a limited ability to accurately localize and characterize PCa lesions through imaging. High-resolution magic angle spinning (HRMAS) (1)H MRS has proven to be a strong potential clinical tool for PCa diagnosis and prognosis. The HRMAS technique allows valuable metabolic information to be obtained from ex vivo intact tissue samples and also enables the performance of histopathology on the same tissue specimens. Studies have found that the quantification of individual metabolite levels and metabolite ratios, as well as metabolomic profiles, shows strong potential to improve accuracy in PCa detection, diagnosis and monitoring. Ex vivo HRMAS is also a valuable tool for the interpretation of in vivo results, including the localization of tumors, and thus has the potential to improve in vivo diagnostic tests used in the clinic. Here, we primarily review publications of HRMAS (1)H MRS and its use for the study of intact human prostate tissue. PMID:23529951

  3. Magic-angle spinning solid-state multinuclear NMR on low-field instrumentation

    NASA Astrophysics Data System (ADS)

    Sørensen, Morten K.; Bakharev, Oleg; Jensen, Ole; Jakobsen, Hans J.; Skibsted, Jørgen; Nielsen, Niels Chr.

    2014-01-01

    Mobile and cost-effective NMR spectroscopy exploiting low-field permanent magnets is a field of tremendous development with obvious applications for arrayed large scale analysis, field work, and industrial screening. So far such demonstrations have concentrated on relaxation measurements and lately high-resolution liquid-state NMR applications. With high-resolution solid-state NMR spectroscopy being increasingly important in a broad variety of applications, we here introduce low-field magic-angle spinning (MAS) solid-state multinuclear NMR based on a commercial ACT 0.45 T 62 mm bore Halbach magnet along with a homebuilt FPGA digital NMR console, amplifiers, and a modified standard 45 mm wide MAS probe for 7 mm rotors. To illustrate the performance of the instrument and address cases where the low magnetic field may offer complementarity to high-field NMR experiments, we demonstrate applications for 23Na MAS NMR with enhanced second-order quadrupolar coupling effects and 31P MAS NMR where reduced influence from chemical shift anisotropy at low field may facilitate determination of heteronuclear dipole-dipole couplings.

  4. A unified heteronuclear decoupling strategy for magic-angle-spinning solid-state NMR spectroscopy

    SciTech Connect

    Equbal, Asif; Bjerring, Morten; Nielsen, Niels Chr. E-mail: ncn@inano.au.dk; Madhu, P. K. E-mail: ncn@inano.au.dk

    2015-05-14

    A unified strategy of two-pulse based heteronuclear decoupling for solid-state magic-angle spinning nuclear magnetic resonance is presented. The analysis presented here shows that different decoupling sequences like two-pulse phase-modulation (TPPM), X-inverse-X (XiX), and finite pulse refocused continuous wave (rCW{sup A}) are basically specific solutions of a more generalized decoupling scheme which incorporates the concept of time-modulation along with phase-modulation. A plethora of other good decoupling conditions apart from the standard, TPPM, XiX, and rCW{sup A} decoupling conditions are available from the unified decoupling approach. The importance of combined time- and phase-modulation in order to achieve the best decoupling conditions is delineated. The consequences of different indirect dipolar interactions arising from cross terms comprising of heteronuclear and homonuclear dipolar coupling terms and also those between heteronuclear dipolar coupling and chemical-shift anisotropy terms are presented in order to unfold the effects of anisotropic interactions under different decoupling conditions. Extensive numerical simulation results are corroborated with experiments on standard amino acids.

  5. Magnetization transfer magic-angle-spinning z-spectroscopy of excised tissues

    NASA Astrophysics Data System (ADS)

    Avni, Reut; Mangoubi, Oren; Bhattacharyya, Rangeet; Degani, Hadassa; Frydman, Lucio

    2009-07-01

    NMR experiments devised to aid in analyses of tissues include magnetization transfer (MT), which can highlight the signals of biological macromolecules through cross-relaxation and/or chemical exchange processes with the bulk 1H water resonance, and high-resolution magic-angle-spinning (HRMAS) methods, akin to those used in solid-state NMR to introduce additional spectral resolution via the averaging of spin anisotropies. This paper explores the result of combining these methodologies, and reports on MT "z-spectroscopy" between water and cell components in excised tissues under a variety of HRMAS conditions. Main features arising from the resulting 1H "MTMAS" experiments include strong spinning sideband manifolds centered at the liquid water shift, high-resolution isotropic features coinciding with aliphatic and amide proton resonances, and a second sideband manifold arising as spinning speeds are increased. Interpretations are given for the origin of these various features, including simulations shedding further light onto the nature of MT NMR signals observed for tissue samples. Concurrently, histological examinations are reported validating the limits of HRMAS NMR procedures to the analysis of tissue samples preserved in a number of different ways.

  6. NMR longitudinal relaxation enhancement in metal halides by heteronuclear polarization exchange during magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Shmyreva, Anna A.; Safdari, Majid; Furó, István; Dvinskikh, Sergey V.

    2016-06-01

    Orders of magnitude decrease of 207Pb and 199Hg NMR longitudinal relaxation times T1 upon magic-angle-spinning (MAS) are observed and systematically investigated in solid lead and mercury halides MeX2 (Me = Pb, Hg and X = Cl, Br, I). In lead(ii) halides, the most dramatic decrease of T1 relative to that in a static sample is in PbI2, while it is smaller but still significant in PbBr2, and not detectable in PbCl2. The effect is magnetic-field dependent but independent of the spinning speed in the range 200-15 000 Hz. The observed relaxation enhancement is explained by laboratory-frame heteronuclear polarization exchange due to crossing between energy levels of spin-1/2 metal nuclei and adjacent quadrupolar-spin halogen nuclei. The enhancement effect is also present in lead-containing organometal halide perovskites. Our results demonstrate that in affected samples, it is the relaxation data recorded under non-spinning conditions that characterize the local properties at the metal sites. A practical advantage of fast relaxation at slow MAS is that spectral shapes with orientational chemical shift anisotropy information well retained can be acquired within a shorter experimental time.

  7. Structure of fully protonated proteins by proton-detected magic-angle spinning NMR.

    PubMed

    Andreas, Loren B; Jaudzems, Kristaps; Stanek, Jan; Lalli, Daniela; Bertarello, Andrea; Le Marchand, Tanguy; Cala-De Paepe, Diane; Kotelovica, Svetlana; Akopjana, Inara; Knott, Benno; Wegner, Sebastian; Engelke, Frank; Lesage, Anne; Emsley, Lyndon; Tars, Kaspars; Herrmann, Torsten; Pintacuda, Guido

    2016-08-16

    Protein structure determination by proton-detected magic-angle spinning (MAS) NMR has focused on highly deuterated samples, in which only a small number of protons are introduced and observation of signals from side chains is extremely limited. Here, we show in two fully protonated proteins that, at 100-kHz MAS and above, spectral resolution is high enough to detect resolved correlations from amide and side-chain protons of all residue types, and to reliably measure a dense network of (1)H-(1)H proximities that define a protein structure. The high data quality allowed the correct identification of internuclear distance restraints encoded in 3D spectra with automated data analysis, resulting in accurate, unbiased, and fast structure determination. Additionally, we find that narrower proton resonance lines, longer coherence lifetimes, and improved magnetization transfer offset the reduced sample size at 100-kHz spinning and above. Less than 2 weeks of experiment time and a single 0.5-mg sample was sufficient for the acquisition of all data necessary for backbone and side-chain resonance assignment and unsupervised structure determination. We expect the technique to pave the way for atomic-resolution structure analysis applicable to a wide range of proteins. PMID:27489348

  8. A LOW-E MAGIC ANGLE SPINNING PROBE FOR BIOLOGICAL SOLID STATE NMR AT 750 MHz

    PubMed Central

    McNeill, Seth A.; Gor’kov, Peter L.; Shetty, Kiran; Brey, William W.; Long, Joanna R.

    2009-01-01

    Crossed-coil NMR probes are a useful tool for reducing sample heating for biological solid state NMR. In a crossed-coil probe, the higher frequency 1H field, which is the primary source of sample heating in conventional probes, is produced by a separate low-inductance resonator. Because a smaller driving voltage is required, the electric field across the sample and the resultant heating is reduced. In this work we describe the development of a magic angle spinning (MAS) solid state NMR probe utilizing a dual resonator. This dual resonator approach, referred to as “Low-E,” was originally developed to reduce heating in samples of mechanically aligned membranes. The study of inherently dilute systems, such as proteins in lipid bilayers, via MAS techniques requires large sample volumes at high field to obtain spectra with adequate signal-to-noise ratio under physiologically relevant conditions. With the Low-E approach, we are able to obtain homogeneous and sufficiently strong radiofrequency fields for both 1H and 13C frequencies in a 4 mm probe with a 1H frequency of 750 MHz. The performance of the probe using windowless dipolar recoupling sequences is demonstrated on model compounds as well as membrane embedded peptides. PMID:19138870

  9. Alignment of high resolution magic angle spinning magnetic resonance spectra using warping methods.

    PubMed

    Giskeødegård, Guro F; Bloemberg, Tom G; Postma, Geert; Sitter, Beathe; Tessem, May-Britt; Gribbestad, Ingrid S; Bathen, Tone F; Buydens, Lutgarde M C

    2010-12-17

    The peaks of magnetic resonance (MR) spectra can be shifted due to variations in physiological and experimental conditions, and correcting for misaligned peaks is an important part of data processing prior to multivariate analysis. In this paper, five warping algorithms (icoshift, COW, fastpa, VPdtw and PTW) are compared for their feasibility in aligning spectral peaks in three sets of high resolution magic angle spinning (HR-MAS) MR spectra with different degrees of misalignments, and their merits are discussed. In addition, extraction of information that might be present in the shifts is examined, both for simulated data and the real MR spectra. The generic evaluation methodology employs a number of frequently used quality criteria for evaluation of the alignments, together with PLS-DA to assess the influence of alignment on the classification outcome. Peak alignment greatly improved the internal similarity of the data sets. Especially icoshift and COW seem suitable for aligning HR-MAS MR spectra, possibly because they perform alignment segment-wise. The choice of reference spectrum can influence the alignment result, and it is advisable to test several references. Information from the peak shifts was extracted, and in one case cancer samples were successfully discriminated from normal tissue based on shift information only. Based on these findings, general recommendations for alignment of HR-MAS MRS data are presented. Where possible, observations are generalized to other data types (e.g. chromatographic data). PMID:21094376

  10. Frequency-stepped acquisition in nuclear magnetic resonance spectroscopy under magic angle spinning

    NASA Astrophysics Data System (ADS)

    Pell, Andrew J.; Clément, Raphaële J.; Grey, Clare P.; Emsley, Lyndon; Pintacuda, Guido

    2013-03-01

    The nuclear magnetic resonance of paramagnetic solids is usually characterized by the presence of large chemical shifts and shift anisotropies due to hyperfine interactions. Frequently the resulting spectra cover a frequency range of several megahertz, which is greater than the bandwidth of commercially available radio-frequency (RF) probes, making it impossible to acquire the whole spectrum in a single experiment. In these cases it common to record a series of spectra, in which the probe is tuned to a different frequency for each, and then sum the results to give the "true" spectrum. While this method is very widely used on static samples, the application of frequency stepping under magic-angle spinning (MAS) is less common, owing to the increased complexity of the spin dynamics when describing the interplay of the RF irradiation with the mechanical rotation of the shift tensor. In this paper, we present a theoretical description, based on the jolting frame formalism of Caravatti et al. [J. Magn. Reson. 55, 88 (1983), 10.1016/0022-2364(83)90279-2], for describing the spin dynamics of a powder sample under MAS when subjected to a selective pulse of low RF-field amplitude. The formalism is used to describe the frequency stepping method under MAS, and under what circumstances the true spectrum is reproduced. We also present an experimental validation of the methodology under ultra-fast MAS with the paramagnetic materials LiMnPO4 and TbCsDPA.

  11. Deuterium magic angle spinning studies of substrates bound to cytochrome P450.

    PubMed

    Lee, H; Ortiz de Montellano, P R; McDermott, A E

    1999-08-17

    We report solid-state deuterium magic angle spinning NMR spectra of perdeuterated adamantane bound to the active site of microcrystalline cytochrome P450cam (CP450cam) in its resting state. CP450cam contains a high-spin ferric (Fe3+) heme in the resting state; the isotropic shift was displaced from the diamagnetic value and varied with temperature consistent with Curie-law dependence. A nondeuterated competitive tighter binding ligand, camphor, was used to displace the adamantane-bound species. This addition resulted in the disappearance of the hyperfine-shifted signal associated with a perdeuterated adamantane bound to CP450cam, while signals presumably associated with adamantane bound to other cavities persisted. We simulated the deuterium spinning side-band intensities for the enzyme-bound species using dipolar hyperfine coupling as the only anisotropic interaction; the deuterium quadrupolar interaction was apparently averaged due to a fast high-symmetry motion. These data provide direct support for previous proposals that substrates are conformationally mobile on the time scale of enzymatic turnover. The simulations suggested that the adamantane binds with an average metal-deuterium distance of 6.2 (+/-0.2) A, corresponding to a dipolar coupling constant of 6.5 (+/-0.5) kHz. PMID:10451377

  12. Molecular dynamics in paramagnetic materials as studied by magic-angle spinning 2H NMR spectra.

    PubMed

    Mizuno, Motohiro; Suzuki, You; Endo, Kazunaka; Murakami, Miwa; Tansho, Masataka; Shimizu, Tadashi

    2007-12-20

    A magic-angle spinning (MAS) 2H NMR experiment was applied to study the molecular motion in paramagnetic compounds. The temperature dependences of 2H MAS NMR spectra were measured for paramagnetic [M(H2O)6][SiF6] (M=Ni2+, Mn2+, Co2+) and diamagnetic [Zn(H2O)6][SiF6]. The paramagnetic compounds exhibited an asymmetric line shape in 2H MAS NMR spectra because of the electron-nuclear dipolar coupling. The drastic changes in the shape of spinning sideband patterns and in the line width of spinning sidebands due to the 180 degrees flip of water molecules and the reorientation of [M(H2O)6]2+ about its C3 axis were observed. In the paramagnetic compounds, paramagnetic spin-spin relaxation and anisotropic g-factor result in additional linebroadening of each of the spinning sidebands. The spectral simulation of MAS 2H NMR, including the effects of paramagnetic shift and anisotropic spin-spin relaxation due to electron-nuclear dipolar coupling and anisotropic g-factor, was performed for several molecular motions. Information about molecular motions in the dynamic range of 10(2) s(-1)

  13. High-resolution magic-angle spinning (13)C spectroscopy of brain tissue at natural abundance.

    PubMed

    Yang, Yongxia; Chen, Lei; Gao, Hongchang; Zeng, Danlin; Yue, Yong; Liu, Maili; Lei, Hao; Deng, Feng; Ye, Chaohui

    2006-03-01

    High-resolution magic-angle spinning (MAS) (1)H and (13)C magnetic resonance spectroscopy (MRS) has recently been applied to study the metabolism in intact biological tissue samples. Because of the low natural abundance and the low gyromagnetic ratio of the (13)C nuclei, signal enhancement techniques such as cross-polarization (CP) and distortionless enhancement by polarization transfer (DEPT) are often employed in MAS (13)C MRS to improve the detection sensitivity. In this study, several sensitivity enhancement techniques commonly used in liquid- and solid-state NMR, including CP, DEPT and nuclear Overhauser enhancement (NOE), were combined with MAS to acquire high-resolution (13)C spectra on intact rat brain tissue at natural abundance, and were compared for their performances. The results showed that different signal enhancement techniques are sensitive to different classes of molecules/metabolites, depending on their molecular weights and mobility. DEPT was found to enhance the signals of low-molecular weight metabolites exclusively, while the signals of lipids, which often are associated with membranes and have relatively lower mobility, were highly sensitive to CP enhancement. PMID:16477685

  14. Dynamic nuclear polarization at 40 kHz magic angle spinning.

    PubMed

    Chaudhari, Sachin R; Berruyer, Pierrick; Gajan, David; Reiter, Christian; Engelke, Frank; Silverio, Daniel L; Copéret, Christophe; Lelli, Moreno; Lesage, Anne; Emsley, Lyndon

    2016-04-21

    DNP-enhanced solid-state NMR spectroscopy under magic angle spinning (MAS) is rapidly developing into a powerful analytical tool to investigate the structure of a wide range of solid materials, because it provides unsurpassed sensitivity gains. Most developments and applications of DNP MAS NMR were so far reported at moderate spinning frequencies (up to 14 kHz using 3.2 mm rotors). Here, using a 1.3 mm MAS DNP probe operating at 18.8 T and ∼100 K, we show that signal amplification factors can be increased by up to a factor two when using smaller volume rotors as compared to 3.2 mm rotors, and report enhancements of around 60 over a range of sample spinning rates from 10 to 40 kHz. Spinning at 40 kHz is also shown to increase (29)Si coherence lifetimes by a factor three as compared to 10 kHz, substantially increasing sensitivity in CPMG type experiments. The contribution of quenching effects to the overall sensitivity gain at very fast MAS is evaluated, and applications are reported on a functionalised mesostructured organic-inorganic material. PMID:27035630

  15. Structure of a protein determined by solid-state magic-angle-spinning NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Castellani, Federica; van Rossum, Barth; Diehl, Annette; Schubert, Mario; Rehbein, Kristina; Oschkinat, Hartmut

    2002-11-01

    The determination of a representative set of protein structures is a chief aim in structural genomics. Solid-state NMR may have a crucial role in structural investigations of those proteins that do not easily form crystals or are not accessible to solution NMR, such as amyloid systems or membrane proteins. Here we present a protein structure determined by solid-state magic-angle-spinning (MAS) NMR. Almost complete 13C and 15N resonance assignments for a micro-crystalline preparation of the α-spectrin Src-homology 3 (SH3) domain formed the basis for the extraction of a set of distance restraints. These restraints were derived from proton-driven spin diffusion (PDSD) spectra of biosynthetically site-directed, labelled samples obtained from bacteria grown using [1,3-13C]glycerol or [2-13C]glycerol as carbon sources. This allowed the observation of long-range distance correlations up to ~7Å. The calculated global fold of the α-spectrin SH3 domain is based on 286 inter-residue 13C-13C and six 15N-15N restraints, all self-consistently obtained by solid-state MAS NMR. This MAS NMR procedure should be widely applicable to small membrane proteins that can be expressed in bacteria.

  16. Cryogenic sample exchange NMR probe for magic angle spinning dynamic nuclear polarization

    PubMed Central

    Barnes, Alexander B.; Mak-Jurkauskas, Melody L.; Matsuki, Yoh; Bajaj, Vikram S.; van der Wel, Patrick C. A.; DeRocher, Ronald; Bryant, Jeffrey; Sirigiri, Jagadishwar R.; Temkin, Richard J.; Lugtenburg, Johan; Herzfeld, Judith; Griffin, Robert G.

    2009-01-01

    We describe a cryogenic sample exchange system that dramatically improves the efficiency of magic angle spinning (MAS) dynamic nuclear polarization (DNP) experiments by reducing the time required to change samples and by improving long-term instrument stability. Changing samples in conventional cryogenic MAS DNP/NMR experiments involves warming the probe to room temperature, detaching all cryogenic, RF, and microwave connections, removing the probe from the magnet, replacing the sample, and reversing all the previous steps, with the entire cycle requiring a few hours. The sample exchange system described here — which relies on an eject pipe attached to the front of the MAS stator and a vacuum jacketed dewar with a bellowed hole — circumvents these procedures. To demonstrate the excellent sensitivity, resolution, and stability achieved with this quadruple resonance sample exchange probe, we have performed high precision distance measurements on the active site of the membrane protein bacteriorhodopsin. We also include a spectrum of the tripeptide N-f-MLF-OH at 100 K which shows 30 Hz linewidths. PMID:19356957

  17. Double-quantum homonuclear rotary resonance: Efficient dipolar recovery in magic-angle spinning nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Nielsen, N. C.; Bildsøe, H.; Jakobsen, H. J.; Levitt, M. H.

    1994-08-01

    We describe an efficient method for the recovery of homonuclear dipole-dipole interactions in magic-angle spinning NMR. Double-quantum homonuclear rotary resonance (2Q-HORROR) is established by fulfilling the condition ωr=2ω1, where ωr is the sample rotation frequency and ω1 is the nutation frequency around an applied resonant radio frequency (rf) field. This resonance can be used for double-quantum filtering and measurement of homonuclear dipolar interactions in the presence of magic-angle spinning. The spin dynamics depend only weakly on crystallite orientation allowing good performance for powder samples. Chemical shift effects are suppressed to zeroth order. The method is demonstrated for singly and doubly 13C labeled L-alanine.

  18. Rotary resonance recoupling of 13C- 1H dipolar interactions in magic angle spinning 13C NMR of dynamic solids

    NASA Astrophysics Data System (ADS)

    Kitchin, Simon J.; Harris, Kenneth D. M.; Aliev, Abil E.; Apperley, David C.

    2000-06-01

    Rotary resonance recoupling of heteronuclear 13C- 1H dipolar interactions in magic angle spinning solid state 13C NMR spectra (recorded under conditions of 1H decoupling at frequency ν1 and magic angle spinning at frequency νr) has been studied for three examples of molecular solids (adamantane, ferrocene and hexamethylbenzene) in which substantial molecular motion is known to occur. It is shown that when rotary resonance conditions are satisfied (i.e. ν1/νr= n, for n=1 or 2), the recoupling can lead to motionally averaged Pake-like powder patterns from which information on 13C- 1H internuclear distances and/or molecular motion can be derived.

  19. Development of a magic-angle spinning nuclear magnetic resonance probe with a cryogenic detection system for sensitivity enhancement

    NASA Astrophysics Data System (ADS)

    Mizuno, Takashi; Hioka, Katsuya; Fujioka, Koji; Takegoshi, K.

    2008-04-01

    A novel nuclear magnetic resonance (NMR) probe for high-resolution solid-state NMR has been developed. In this probe, temperature of the detection coil is kept at cryogenic temperature (˜12K) for sensitivity enhancement, which is achieved not only by suppression of thermal noise but also by increment of a Q factor of the coil. A marked feature of this probe is that a sample rotating at magic angle is thermally isolated from the cryogenic system in order to realize high-resolution solid-state NMR measurement at various sample temperatures. We call this system as cryocoil magic-angle spinning (cryocoil MAS). H1 MAS NMR with the coil temperature of ˜20K was successfully observed for solid adamantane rotating at room temperature, and signal-to-noise increment due to this cryocoil approach was confirmed.

  20. High resolution structural characterization of Aβ42 amyloid fibrils by magic angle spinning NMR.

    PubMed

    Colvin, Michael T; Silvers, Robert; Frohm, Birgitta; Su, Yongchao; Linse, Sara; Griffin, Robert G

    2015-06-17

    The presence of amyloid plaques composed of amyloid beta (Aβ) fibrils is a hallmark of Alzheimer's disease (AD). The Aβ peptide is present as several length variants with two common alloforms consisting of 40 and 42 amino acids, denoted Aβ1-40 and Aβ1-42, respectively. While there have been numerous reports that structurally characterize fibrils of Aβ1-40, very little is known about the structure of amyloid fibrils of Aβ1-42, which are considered the more toxic alloform involved in AD. We have prepared isotopically (13)C/(15)N labeled AβM01-42 fibrils in vitro from recombinant protein and examined their (13)C-(13)C and (13)C-(15)N magic angle spinning (MAS) NMR spectra. In contrast to several other studies of Aβ fibrils, we observe spectra with excellent resolution and a single set of chemical shifts, suggesting the presence of a single fibril morphology. We report the initial structural characterization of AβM01-42 fibrils utilizing (13)C and (15)N shift assignments of 38 of the 43 residues, including the backbone and side chains, obtained through a series of cross-polarization based 2D and 3D (13)C-(13)C, (13)C-(15)N MAS NMR experiments for rigid residues along with J-based 2D TOBSY experiments for dynamic residues. We find that the first ∼5 residues are dynamic and most efficiently detected in a J-based TOBSY spectrum. In contrast, residues 16-42 are easily observed in cross-polarization experiments and most likely form the amyloid core. Calculation of ψ and φ dihedral angles from the chemical shift assignments indicate that 4 β-strands are present in the fibril's secondary structure. PMID:26001057

  1. High Resolution Structural Characterization of Aβ42 Amyloid Fibrils by Magic Angle Spinning NMR

    PubMed Central

    2015-01-01

    The presence of amyloid plaques composed of amyloid beta (Aβ) fibrils is a hallmark of Alzheimer’s disease (AD). The Aβ peptide is present as several length variants with two common alloforms consisting of 40 and 42 amino acids, denoted Aβ1–40 and Aβ1–42, respectively. While there have been numerous reports that structurally characterize fibrils of Aβ1–40, very little is known about the structure of amyloid fibrils of Aβ1–42, which are considered the more toxic alloform involved in AD. We have prepared isotopically 13C/15N labeled AβM01–42 fibrils in vitro from recombinant protein and examined their 13C–13C and 13C–15N magic angle spinning (MAS) NMR spectra. In contrast to several other studies of Aβ fibrils, we observe spectra with excellent resolution and a single set of chemical shifts, suggesting the presence of a single fibril morphology. We report the initial structural characterization of AβM01–42 fibrils utilizing 13C and 15N shift assignments of 38 of the 43 residues, including the backbone and side chains, obtained through a series of cross-polarization based 2D and 3D 13C–13C, 13C–15N MAS NMR experiments for rigid residues along with J-based 2D TOBSY experiments for dynamic residues. We find that the first ∼5 residues are dynamic and most efficiently detected in a J-based TOBSY spectrum. In contrast, residues 16–42 are easily observed in cross-polarization experiments and most likely form the amyloid core. Calculation of ψ and φ dihedral angles from the chemical shift assignments indicate that 4 β-strands are present in the fibril’s secondary structure. PMID:26001057

  2. High zenith angle observations of PKS 2155-304 with the MAGIC-I telescope

    NASA Astrophysics Data System (ADS)

    Aleksić, J.; Alvarez, E. A.; Antonelli, L. A.; Antoranz, P.; Asensio, M.; Backes, M.; Barres de Almeida, U.; Barrio, J. A.; Bastieri, D.; Becerra González, J.; Bednarek, W.; Berdyugin, A.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Boller, A.; Bonnoli, G.; Borla Tridon, D.; Braun, I.; Bretz, T.; Cañellas, A.; Carmona, E.; Carosi, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Cossio, L.; Covino, S.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Cea del Pozo, E.; De Lotto, B.; Delgado Mendez, C.; Diago Ortega, A.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Eisenacher, D.; Elsaesser, D.; Ferenc, D.; Fonseca, M. V.; Font, L.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido, D.; Giavitto, G.; Godinović, N.; Gozzini, S. R.; Hadasch, D.; Häfner, D.; Herrero, A.; Hildebrand, D.; Höhne-Mönch, D.; Hose, J.; Hrupec, D.; Jogler, T.; Kellermann, H.; Klepser, S.; Krähenbühl, T.; Krause, J.; Kushida, J.; La Barbera, A.; Lelas, D.; Leonardo, E.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; López, M.; López, R.; López-Oramas, A.; Lorenz, E.; Makariev, M.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moldón, J.; Moralejo, A.; Munar-Adrover, P.; Niedzwiecki, A.; Nieto, D.; Nilsson, K.; Nowak, N.; Orito, R.; Paiano, S.; Paneque, D.; Paoletti, R.; Pardo, S.; Paredes, J. M.; Partini, S.; Perez-Torres, M. A.; Persic, M.; Peruzzo, L.; Pilia, M.; Pochon, J.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Puerto Gimenez, I.; Puljak, I.; Reichardt, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rügamer, S.; Saggion, A.; Saito, K.; Saito, T. Y.; Salvati, M.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shayduk, M.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Spiro, S.; Stamatescu, V.; Stamerra, A.; Steinke, B.; Storz, J.; Strah, N.; Sun, S.; Surić, T.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Tibolla, O.; Torres, D. F.; Treves, A.; Uellenbeck, M.; Vankov, H.; Vogler, P.; Wagner, R. M.; Weitzel, Q.; Zabalza, V.; Zandanel, F.; Zanin, R.

    2012-08-01

    Context. The high frequency peaked BL Lac PKS 2155-304 with a redshift of z = 0.116 was discovered in 1997 in the very high energy (VHE, E > 100 GeV) γ-ray range by the University of Durham Mark VI γ-ray Cherenkov telescope in Australia with a flux corresponding to 20% of the Crab Nebula flux. It was later observed and detected with high significance by the southern Cherenkov observatory H.E.S.S. establishing this source as the best studied southern TeV blazar. Detection from the northern hemisphere is difficult due to challenging observation conditions under large zenith angles. In July 2006, the H.E.S.S. collaboration reported an extraordinary outburst of VHE γ-emission. During the outburst, the VHE γ-ray emission was found to be variable on the time scales of minutes and with a mean flux of ~7 times the flux observed from the Crab Nebula. Follow-up observations with the MAGIC-I standalone Cherenkov telescope were triggered by this extraordinary outburst and PKS 2155-304 was observed between 28 July to 2 August 2006 for 15 h at large zenith angles. Aims: We studied the behavior of the source after its extraordinary flare. Furthermore, we developed an analysis method in order to analyze these data taken under large zenith angles. Methods: Here we present an enhanced analysis method for data taken at high zenith angles. We developed improved methods for event selection that led to a better background suppression. Results: The quality of the results presented here is superior to the results presented previously for this data set: detection of the source on a higher significance level and a lower analysis threshold. The averaged energy spectrum we derived has a spectral index of (-3.5 ± 0.2) above 400 GeV, which is in good agreement with the spectral shape measured by H.E.S.S. during the major flare on MJD 53 944. Furthermore, we present the spectral energy distribution modeling of PKS 2155-304. With our observations we increased the duty cycle of the source

  3. Microwave field distribution in a magic angle spinning dynamic nuclear polarization NMR probe

    NASA Astrophysics Data System (ADS)

    Nanni, Emilio A.; Barnes, Alexander B.; Matsuki, Yoh; Woskov, Paul P.; Corzilius, Björn; Griffin, Robert G.; Temkin, Richard J.

    2011-05-01

    We present a calculation of the microwave field distribution in a magic angle spinning (MAS) probe utilized in dynamic nuclear polarization (DNP) experiments. The microwave magnetic field (B 1 S) profile was obtained from simulations performed with the High Frequency Structure Simulator (HFSS) software suite, using a model that includes the launching antenna, the outer Kel-F stator housing coated with Ag, the RF coil, and the 4 mm diameter sapphire rotor containing the sample. The predicted average B 1 S field is 13 μT/W 1/2, where S denotes the electron spin. For a routinely achievable input power of 5 W the corresponding value is γSB 1 S = 0.84 MHz. The calculations provide insights into the coupling of the microwave power to the sample, including reflections from the RF coil and diffraction of the power transmitted through the coil. The variation of enhancement with rotor wall thickness was also successfully simulated. A second, simplified calculation was performed using a single pass model based on Gaussian beam propagation and Fresnel diffraction. This model provided additional physical insight and was in good agreement with the full HFSS simulation. These calculations indicate approaches to increasing the coupling of the microwave power to the sample, including the use of a converging lens and fine adjustment of the spacing of the windings of the RF coil. The present results should prove useful in optimizing the coupling of microwave power to the sample in future DNP experiments. Finally, the results of the simulation were used to predict the cross effect DNP enhancement ( ɛ) vs. ω1 S/(2 π) for a sample of 13C-urea dissolved in a 60:40 glycerol/water mixture containing the polarizing agent TOTAPOL; very good agreement was obtained between theory and experiment.

  4. Tailored low-power cross-polarization under fast magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Demers, Jean-Philippe; Vijayan, Vinesh; Becker, Stefan; Lange, Adam

    2010-08-01

    High static magnetic fields and very fast magic-angle spinning (MAS) promise to improve resolution and sensitivity of solid-state NMR experiments. The fast MAS regime has permitted the development of low-power cross-polarization schemes, such as second-order cross-polarization (SOCP), which prevent heat deposition in the sample. Those schemes are however limited in bandwidth, as weak radio-frequency (RF) fields only cover a small chemical shift range for rare nuclei (e.g. 13C). Another consideration is that the efficiency of cross-polarization is very sensitive to magnetization decay that occurs during the spin-lock pulse on the abundant nuclei (e.g. 1H). Having characterized this decay in glutamine at 60 kHz MAS, we propose two complementary strategies to tailor cross-polarization to desired spectral regions at low RF power. In the case of multiple sites with small chemical shift dispersion, a larger bandwidth for SOCP is obtained by slightly increasing the RF power while avoiding recoupling conditions that lead to fast spin-lock decay. In the case of two spectral regions with large chemical shift offset, an extension of the existing low-power schemes, called MOD-CP, is introduced. It consists of a spin-lock on 1H and an amplitude-modulated spin-lock on the rare nucleus. The range of excited chemical shifts is assessed by experimental excitation profiles and numerical simulation of an I 2S spin system. All SOCP-based schemes exhibit higher sensitivity than high-power CP schemes, as demonstrated on solid (glutamine) and semi-solid (hydrated, micro-crystalline ubiquitin) samples.

  5. Correlating high-resolution magic angle spinning NMR spectroscopy and gene analysis in osteoarthritic cartilage.

    PubMed

    Tufts, Lauren; Shet Vishnudas, Keerthi; Fu, Eunice; Kurhanewicz, John; Ries, Michael; Alliston, Tamara; Li, Xiaojuan

    2015-05-01

    Osteoarthritis (OA) is a common multifactorial and heterogeneous degenerative joint disease, and biochemical changes in cartilage matrix occur during the early stages of OA before morphological changes occur. Thus, it is desired to measure regional biochemical changes in the joint. High-resolution magic angle spinning (HRMAS) NMR spectroscopy is a powerful method of observing cartilaginous biochemical changes ex vivo, including the concentrations of alanine and N-acetyl, which are markers of collagen and total proteoglycan content, respectively. Previous studies have observed significant changes in chondrocyte metabolism of OA cartilage via the altered gene expression profiles of ACAN, COL2A1 and MMP13, which encode aggrecan, type II collagen and matrix metalloproteinase 13 (a protein crucial in the degradation of type II collagen), respectively. Employing HRMAS, this study aimed to elucidate potential relationships between N-acetyl and/or alanine and ACAN, COL2A1 and/or MMP13 expression profiles in OA cartilage. Thirty samples from the condyles of five subjects undergoing total knee arthroplasty to treat OA were collected. HRMAS spectra were obtained at 11.7 T for each sample. RNA was subsequently extracted to determine gene expression profiles. A significant negative correlation between N-acetyl metabolite and ACAN gene expression levels was observed; this provides further evidence of N-acetyl as a biomarker of cartilage degeneration. The alanine doublet was distinguished in the spectra of 15 of the 30 specimens of this study. Alanine can only be detected with HRMAS NMR spectroscopy when the collagen framework has been degraded such that alanine is sufficiently mobile to form a distinguished peak in the spectrum. Thus, HRMAS NMR spectroscopy may provide unique localized measurements of collagenous degeneration in OA cartilage. The identification of imaging markers that could provide a link between OA pathology and chondrocyte metabolism will facilitate the

  6. Spinning-sideband patterns in multiple-quantum magic-angle spinning NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Friedrich, Ulli

    1998-12-01

    Recent interest has focused on solid-state NMR experiments which excite multiple-quantum (MQ) coherences in the presence of magic-angle spinning (MAS). Such experiments have been applied to both dipolar-coupled spin Ι = 1/2 and half-integer quadrupolar systems. A feature common to both cases is the observation of interesting spinning sideband patterns in the indirect (MQ) dimension. In this paper, the origin of these patterns is reviewed in terms of two distinct mechanisms: first, rotor encoding of the dipolar or quadrupolar interaction caused by the change in the Hamiltonian active during the MQ reconversion period relative to the excitation period (reconversion rotor encoding, RRE); and, second, rotor modulation of the interaction during the evolution of the MQ coherences in the t1 dimension (evolution rotor modulation, ERM). Only the first mechanism is present for total spin coherences, while for lower-order MQ coherences both mechanisms contribute to the pattern. For dipolar and quadrupolar model systems, i.e., the three protons of a methyl group and quadrupolar nuclei with spin Ι = 3/2 and Ι = 5/2 and axially symmetric first-order quadrupolar interactions, analytical expressions are derived for all orders of MQ MAS signals. Simulations based on these analytical expressions and numerical density matrix simulations are compared with experimental spectra. Additional perturbing influences, such as the heteronuclear dipolar coupling between a quadrupolar and a spin Ι = 1/2 nucleus, are taken into account. The effect of dipolar couplings on a quadrupolar MQ spectrum is found to be enhanced by the order of the observed MQ coherence.

  7. Rotor Design for High Pressure Magic Angle Spinning Nuclear Magnetic Resonance

    SciTech Connect

    Turcu, Romulus V.F.; Hoyt, David W.; Rosso, Kevin M.; Sears, Jesse A.; Loring, John S.; Felmy, Andrew R.; Hu, Jian Z.

    2013-01-01

    High pressure magic angle spinning (MAS) nuclear magnetic resonance (NMR) with a sample spinning rate exceeding 2.1 kHz and pressure greater than 165 bar has never been realized. In this work, a new sample cell design is reported, suitable for constructing cells of different sizes. Using a 7.5 mm high pressure MAS rotor as an example, internal pressure as high as 200 bar at a sample spinning rate of 6 kHz is achieved. The new high pressure MAS rotor is re-usable and compatible with most commercial NMR set-ups, exhibiting low 1H and 13C NMR background and offering maximal NMR sensitivity. As an example of its many possible applications, this new capability is applied to determine reaction products associated with the carbonation reaction of a natural mineral, antigorite ((Mg,Fe2+)3Si2O5(OH)4), in contact with liquid water in water-saturated supercritical CO2 (scCO2) at 150 bar and 50 deg C. This mineral is relevant to the deep geologic disposal of CO2, but its iron content results in too many sample spinning sidebands at low spinning rate. Hence, this chemical system is a good case study to demonstrate the utility of the higher sample spinning rates that can be achieved by our new rotor design. We expect this new capability will be useful for exploring solid-state, including interfacial, chemistry at new levels of high-pressure in a wide variety of fields.

  8. Rotor design for high pressure magic angle spinning nuclear magnetic resonance.

    PubMed

    Turcu, Romulus V F; Hoyt, David W; Rosso, Kevin M; Sears, Jesse A; Loring, John S; Felmy, Andrew R; Hu, Jian Zhi

    2013-01-01

    High pressure magic angle spinning (MAS) nuclear magnetic resonance (NMR) with a sample spinning rate exceeding 2.1 kHz and pressure greater than 165 bar has never been realized. In this work, a new sample cell design is reported, suitable for constructing cells of different sizes. Using a 7.5 mm high pressure MAS rotor as an example, internal pressure as high as 200 bar at a sample spinning rate of 6 kHz is achieved. The new high pressure MAS rotor is re-usable and compatible with most commercial NMR set-ups, exhibiting low (1)H and (13)C NMR background and offering maximal NMR sensitivity. As an example of its many possible applications, this new capability is applied to determine reaction products associated with the carbonation reaction of a natural mineral, antigorite ((Mg,Fe(2+))(3)Si(2)O(5)(OH)(4)), in contact with liquid water in water-saturated supercritical CO(2) (scCO(2)) at 150 bar and 50°C. This mineral is relevant to the deep geologic disposal of CO(2), but its iron content results in too many sample spinning sidebands at low spinning rate. Hence, this chemical system is a good case study to demonstrate the utility of the higher sample spinning rates that can be achieved by our new rotor design. We expect this new capability will be useful for exploring solid-state, including interfacial, chemistry at new levels of high-pressure in a wide variety of fields. PMID:23220181

  9. Rotor design for high pressure magic angle spinning nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Turcu, Romulus V. F.; Hoyt, David W.; Rosso, Kevin M.; Sears, Jesse A.; Loring, John S.; Felmy, Andrew R.; Hu, Jian Zhi

    2013-01-01

    High pressure magic angle spinning (MAS) nuclear magnetic resonance (NMR) with a sample spinning rate exceeding 2.1 kHz and pressure greater than 165 bar has never been realized. In this work, a new sample cell design is reported, suitable for constructing cells of different sizes. Using a 7.5 mm high pressure MAS rotor as an example, internal pressure as high as 200 bar at a sample spinning rate of 6 kHz is achieved. The new high pressure MAS rotor is re-usable and compatible with most commercial NMR set-ups, exhibiting low 1H and 13C NMR background and offering maximal NMR sensitivity. As an example of its many possible applications, this new capability is applied to determine reaction products associated with the carbonation reaction of a natural mineral, antigorite ((Mg,Fe2+)3Si2O5(OH)4), in contact with liquid water in water-saturated supercritical CO2 (scCO2) at 150 bar and 50 °C. This mineral is relevant to the deep geologic disposal of CO2, but its iron content results in too many sample spinning sidebands at low spinning rate. Hence, this chemical system is a good case study to demonstrate the utility of the higher sample spinning rates that can be achieved by our new rotor design. We expect this new capability will be useful for exploring solid-state, including interfacial, chemistry at new levels of high-pressure in a wide variety of fields.

  10. Microwave field distribution in a magic angle spinning dynamic nuclear polarization NMR probe.

    PubMed

    Nanni, Emilio A; Barnes, Alexander B; Matsuki, Yoh; Woskov, Paul P; Corzilius, Björn; Griffin, Robert G; Temkin, Richard J

    2011-05-01

    We present a calculation of the microwave field distribution in a magic angle spinning (MAS) probe utilized in dynamic nuclear polarization (DNP) experiments. The microwave magnetic field (B(1S)) profile was obtained from simulations performed with the High Frequency Structure Simulator (HFSS) software suite, using a model that includes the launching antenna, the outer Kel-F stator housing coated with Ag, the RF coil, and the 4mm diameter sapphire rotor containing the sample. The predicted average B(1S) field is 13μT/W(1/2), where S denotes the electron spin. For a routinely achievable input power of 5W the corresponding value is γ(S)B(1S)=0.84MHz. The calculations provide insights into the coupling of the microwave power to the sample, including reflections from the RF coil and diffraction of the power transmitted through the coil. The variation of enhancement with rotor wall thickness was also successfully simulated. A second, simplified calculation was performed using a single pass model based on Gaussian beam propagation and Fresnel diffraction. This model provided additional physical insight and was in good agreement with the full HFSS simulation. These calculations indicate approaches to increasing the coupling of the microwave power to the sample, including the use of a converging lens and fine adjustment of the spacing of the windings of the RF coil. The present results should prove useful in optimizing the coupling of microwave power to the sample in future DNP experiments. Finally, the results of the simulation were used to predict the cross effect DNP enhancement (ϵ) vs. ω(1S)/(2π) for a sample of (13)C-urea dissolved in a 60:40 glycerol/water mixture containing the polarizing agent TOTAPOL; very good agreement was obtained between theory and experiment. PMID:21382733

  11. Intermolecular structure determination of amyloid fibrils with magic-angle spinning and dynamic nuclear polarization NMR

    PubMed Central

    Bayro, Marvin J.; Debelouchina, Galia T.; Eddy, Matthew T.; Birkett, Neil R.; MacPhee, Catherine E.; Rosay, Melanie; Maas, Werner E.; Dobson, Christopher M.

    2011-01-01

    We describe magic-angle spinning NMR experiments designed to elucidate the interstrand architecture of amyloid fibrils. Three methods are introduced for this purpose, two being based on the analysis of long-range 13C-13C correlation spectra and a third based on the identification of intermolecular interactions in 13C-15N spectra. We show, in studies of fibrils formed by the 86-residue SH3 domain of PI3 kinase (PI3-SH3), that efficient 13C-13C correlation spectra display a resonance degeneracy that establishes a parallel, in-register alignment of the proteins in the amyloid fibrils. In addition, this degeneracy can be circumvented to yield direct intermolecular constraints. The 13C-13C experiments are corroborated by 15N-13C correlation spectrum obtained from a mixed [15N,12C]/[14N,13C] sample which directly quantifies interstrand distances. Furthermore, when the spectra are recorded with signal enhancement provided by dynamic nuclear polarization (DNP) at 100 K, we demonstrate a dramatic increase (from 23 to 52) in the number of intermolecular 15N-13C constraints present in the spectra. The increase in the information content is due to the enhanced signal intensities and to the fact that dynamic processes, leading to spectral intensity losses, are quenched at low temperatures. Thus, acquisition of low temperature spectra addresses a problem that is frequently encountered in MAS spectra of proteins. In total the experiments provide 111 intermolecular 13C-13C and 15N-13C constraints that establish that the PI3-SH3 protein strands are aligned in a parallel, in-register arrangement within the amyloid fibril. PMID:21774549

  12. Microwave Field Distribution in a Magic Angle Spinning Dynamic Nuclear Polarization NMR Probe

    PubMed Central

    Nanni, Emilio A.; Barnes, Alexander B.; Matsuki, Yoh; Woskov, Paul P.; Corzilius, Björn; Griffin, Robert G.; Temkin, Richard J.

    2011-01-01

    We present a calculation of the microwave field distribution in a magic angle spinning (MAS) probe utilized in dynamic nuclear polarization (DNP) experiments. The microwave magnetic field (B1S) profile was obtained from simulations performed with the High Frequency Structure Simulator (HFSS) software suite, using a model that includes the launching antenna, the outer Kel-F stator housing coated with Ag, the RF coil, and the 4 mm diameter sapphire rotor containing the sample. The predicted average B1S field is 13µT/W1/2, where S denotes the electron spin. For a routinely achievable input power of 5 W the corresponding value is γ SB1S = 0.84 MHz. The calculations provide insights into the coupling of the microwave power to the sample, including reflections from the RF coil and diffraction of the power transmitted through the coil. The variation of enhancement with rotor wall thickness was also successfully simulated. A second, simplified calculation was performed using a single pass model based on Gaussian beam propagation and Fresnel diffraction. This model provided additional physical insight and was in good agreement with the full HFSS simulation. These calculations indicate approaches to increasing the coupling of the microwave power to the sample, including the use of a converging lens and fine adjustment of the spacing of the windings of the RF coil. The present results should prove useful in optimizing the coupling of microwave power to the sample in future DNP experiments. Finally, the results of the simulation were used to predict the cross effect DNP enhancement (ε) vs. ω1S/(2π) for a sample of 13C-urea dissolved in a 60:40 glycerol/water mixture containing the polarizing agent TOTAPOL; very good agreement was obtained between theory and experiment. PMID:21382733

  13. Nuclear depolarization and absolute sensitivity in magic-angle spinning cross effect dynamic nuclear polarization.

    PubMed

    Mentink-Vigier, Frédéric; Paul, Subhradip; Lee, Daniel; Feintuch, Akiva; Hediger, Sabine; Vega, Shimon; De Paëpe, Gaël

    2015-09-14

    Over the last two decades solid state Nuclear Magnetic Resonance has witnessed a breakthrough in increasing the nuclear polarization, and thus experimental sensitivity, with the advent of Magic Angle Spinning Dynamic Nuclear Polarization (MAS-DNP). To enhance the nuclear polarization of protons, exogenous nitroxide biradicals such as TOTAPOL or AMUPOL are routinely used. Their efficiency is usually assessed as the ratio between the NMR signal intensity in the presence and the absence of microwave irradiation εon/off. While TOTAPOL delivers an enhancement εon/off of about 60 on a model sample, the more recent AMUPOL is more efficient: >200 at 100 K. Such a comparison is valid as long as the signal measured in the absence of microwaves is merely the Boltzmann polarization and is not affected by the spinning of the sample. However, recent MAS-DNP studies at 25 K by Thurber and Tycko (2014) have demonstrated that the presence of nitroxide biradicals combined with sample spinning can lead to a depolarized nuclear state, below the Boltzmann polarization. In this work we demonstrate that TOTAPOL and AMUPOL both lead to observable depolarization at ≈110 K, and that the magnitude of this depolarization is radical dependent. Compared to the static sample, TOTAPOL and AMUPOL lead, respectively, to nuclear polarization losses of up to 20% and 60% at a 10 kHz MAS frequency, while Trityl OX63 does not depolarize at all. This experimental work is analyzed using a theoretical model that explains how the depolarization process works under MAS and gives new insights into the DNP mechanism and into the spin parameters, which are relevant for the efficiency of a biradical. In light of these results, the outstanding performance of AMUPOL must be revised and we propose a new method to assess the polarization gain for future radicals. PMID:26235749

  14. Solid-state {sup 17}O magic-angle and dynamic-angle spinning NMR study of the SiO{sub 2} polymorph coesite

    SciTech Connect

    Grandinetti, P.J.; Baltisberger, J.H.; Farnan, I.; Stebbins, J.F.; Werner, U.; Pines, A. |

    1995-08-10

    Five distinctly resolved {sup 17}O solid-state NMR resonances in room temperature coesite, an SiO{sub 2} polymorph, have been observed and assigned using dynamic angle spinning (DAS) at 11.7 T along with magic angle spinning (MAS) spectra at 9.4 and 11.7 T. The {sup 17}O quadrupolar parameters for each of the five oxygen environments in coesite are correlated with the Si-O-Si bridging bond angles determined by diffraction experiments. The sign of e{sup 2}-qQ/h along with the orientation of the electric field gradient for oxygen in the Si-O-Si linkage were determined from a Townes-Dailey analysis of the data. 41 refs., 7 figs., 5 tabs.

  15. Characterization of lithium coordination sites with magic-angle spinning NMR

    NASA Astrophysics Data System (ADS)

    Haimovich, A.; Goldbourt, A.

    2015-05-01

    Lithium, in the form of lithium carbonate, is one of the most common drugs for bipolar disorder. Lithium is also considered to have an effect on many other cellular processes hence it possesses additional therapeutic as well as side effects. In order to quantitatively characterize the binding mode of lithium, it is required to identify the interacting species and measure their distances from the metal center. Here we use magic-angle spinning (MAS) solid-state NMR to study the binding site of lithium in complex with glycine and water (LiGlyW). Such a compound is a good enzyme mimetic since lithium is four-coordinated to one water molecule and three carboxylic groups. Distance measurements to carbons are performed using a 2D transferred echo double resonance (TEDOR) MAS solid-state NMR experiment, and water binding is probed by heteronuclear high-resolution proton-lithium and proton-carbon correlation (wPMLG-HETCOR) experiments. Both HETCOR experiments separate the main complex from impurities and non-specifically bound lithium species, demonstrating the sensitivity of the method to probe the species in the binding site. Optimizations of the TEDOR pulse scheme in the case of a quadrupolar nucleus with a small quadrupole coupling constant show that it is most efficient when pulses are positioned on the spin-1/2 (carbon-13) nucleus. Since the intensity of the TEDOR signal is not normalized, careful data analysis that considers both intensity and dipolar oscillations has to be performed. Nevertheless we show that accurate distances can be extracted for both carbons of the bound glycine and that these distances are consistent with the X-ray data and with lithium in a tetrahedral environment. The lithium environment in the complex is very similar to the binding site in inositol monophosphatase, an enzyme associated with bipolar disorder and the putative target for lithium therapy. A 2D TEDOR experiment applied to the bacterial SuhB gene product of this enzyme was designed

  16. High Resolution Magic Angle Spinning 1H-NMR Metabolic Profiling of Nanoliter Biological Tissues at High Magnetic Field

    SciTech Connect

    Feng, Ju; Hu, Jian Z.; Burton, Sarah D.; Hoyt, David W.

    2013-03-05

    It is demonstrated that a high resolution magic angle spinning 1H-NMR spectrum of biological tissue samples with volumes as small as 150 nanoliters, or 0.15 mg in weight, can be acquired in a few minutes at 21.1 T magnetic field using a commercial 1.6 mm fast-MAS probe with minor modification of the MAS rotor. The strategies of sealing the samples inside the MAS rotor to avoid fluid leakage as well as the ways of optimizing the signal to noise are discussed.

  17. High-pressure, high-temperature magic angle spinning nuclear magnetic resonance devices and processes for making and using same

    DOEpatents

    Hu, Jian Zhi; Hu, Mary Y.; Townsend, Mark R.; Lercher, Johannes A.; Peden, Charles H. F.

    2015-10-06

    Re-usable ceramic magic angle spinning (MAS) NMR rotors constructed of high-mechanic strength ceramics are detailed that include a sample compartment that maintains high pressures up to at least about 200 atmospheres (atm) and high temperatures up to about least about 300.degree. C. during operation. The rotor designs minimize pressure losses stemming from penetration over an extended period of time. The present invention makes possible a variety of in-situ high pressure, high temperature MAS NMR experiments not previously achieved in the prior art.

  18. Lipid bilayer preparations of membrane proteins for oriented and magic-angle spinning solid-state NMR samples

    PubMed Central

    Das, Nabanita; Murray, Dylan T; Cross, Timothy A

    2014-01-01

    Solid-state NMR spectroscopy has been used successfully for characterizing the structure and dynamics of membrane proteins as well as their interactions with other proteins in lipid bilayers. such an environment is often necessary for achieving native-like structures. sample preparation is the key to this success. Here we present a detailed description of a robust protocol that results in high-quality membrane protein samples for both magic-angle spinning and oriented-sample solid-state NMR. the procedure is demonstrated using two proteins: CrgA (two transmembrane helices) and rv1861 (three transmembrane helices), both from Mycobacterium tuberculosis. the success of this procedure relies on two points. First, for samples for both types of NMR experiment, the reconstitution of the protein from a detergent environment to an environment in which it is incorporated into liposomes results in ‘complete’ removal of detergent. second, for the oriented samples, proper dehydration followed by rehydration of the proteoliposomes is essential. By using this protocol, proteoliposome samples for magic-angle spinning NMR and uniformly aligned samples (orientational mosaicity of <1°) for oriented-sample NMR can be obtained within 10 d. PMID:24157546

  19. (11)B MAS NMR and First-Principles Study of the [OBO3] Pyramids in Borates.

    PubMed

    Zhou, Bing; Sun, Wei; Zhao, Biao-Chun; Mi, Jin-Xiao; Laskowski, Robert; Terskikh, Victor; Zhang, Xi; Yang, Lingyun; Botis, Sanda M; Sherriff, Barbara L; Pan, Yuanming

    2016-03-01

    Borates are built from the [Bϕ3] planar triangles and the [Bϕ4] tetrahedral groups, where ϕ denotes O or OH. However, the [Bϕ4] groups in some borates are highly distorted to include three normal B-O bonds and one anomalously long B-O bond and, therefore, are best described as the [OBO3] pyramids. Four synthetic borates of the boracite-type structures (Mg3B7O13Br, Cu3B7O13Br, Zn3B7O13Cl, and Mg3B7O13Cl) containing a range of [OBO3] pyramids were investigated by multifield (7.05, 14.1, and 21.1 T) (11)B magic-angle spinning nuclear magnetic resonance (MAS NMR), triple quantum (3Q) MAS NMR experiments, as well as density functional theory calculations. The high-resolution (11)B MAS NMR spectra supported by theoretical predictions show that the [OBO3] pyramids are characterized by isotropic chemical shifts δiso((11)B) from 1.4(1) to 4.9(1) ppm and nuclear quadrupole parameters CQ((11)B) up to 1.3(1) MHz, both significantly different from those of the [BO4] and [BO3] groups in borates. These δiso((11)B) and CQ((11)B) values indicate that the [OBO3] pyramids represent an intermediate state between the [BO4] tetrahedra and [BO3] triangles and demonstrate that the (11)B NMR parameters of four-coordinate boron oxyanions are sensitive to local structural environments. The orientation of the calculated unique electronic field gradient tensor element Vzz of the [OBO3] pyramids is aligned approximately along the direction of the anomalously long B-O bond, corresponding to B-2pz with the lowest electron density. PMID:26914372

  20. Floquet-Magnus expansion for general N-coupled spins systems in magic-angle spinning nuclear magnetic resonance spectra

    NASA Astrophysics Data System (ADS)

    Mananga, Eugene Stephane; Charpentier, Thibault

    2015-04-01

    In this paper we present a theoretical perturbative approach for describing the NMR spectrum of strongly dipolar-coupled spin systems under fast magic-angle spinning. Our treatment is based on two approaches: the Floquet approach and the Floquet-Magnus expansion. The Floquet approach is well known in the NMR community as a perturbative approach to get analytical approximations. Numerical procedures are based on step-by-step numerical integration of the corresponding differential equations. The Floquet-Magnus expansion is a perturbative approach of the Floquet theory. Furthermore, we address the " γ -encoding" effect using the Floquet-Magnus expansion approach. We show that the average over " γ " angle can be performed for any Hamiltonian with γ symmetry.

  1. Magic-angle-spinning NMR of the drug resistant S31N M2 proton transporter from influenza A.

    PubMed

    Andreas, Loren B; Eddy, Matthew T; Chou, James J; Griffin, Robert G

    2012-05-01

    We report chemical shift assignments of the drug-resistant S31N mutant of M2(18-60) determined using 3D magic-angle-spinning (MAS) NMR spectra acquired with a (15)N-(13)C ZF-TEDOR transfer followed by (13)C-(13)C mixing by RFDR. The MAS spectra reveal two sets of resonances, indicating that the tetramer assembles as a dimer of dimers, similar to the wild-type channel. Helicies from the two sets of chemical shifts are shown to be in close proximity at residue H37, and the assignments reveal a difference in the helix torsion angles, as predicted by TALOS+, for the key resistance residue N31. In contrast to wild-type M2(18-60), chemical shift changes are minimal upon addition of the inhibitor rimantadine, suggesting that the drug does not bind to S31N M2. PMID:22480220

  2. SCAM-STMAS: satellite-transition MAS NMR of quadrupolar nuclei with self-compensation for magic-angle misset

    NASA Astrophysics Data System (ADS)

    Ashbrook, Sharon E.; Wimperis, Stephen

    2003-06-01

    Several methods are available for the acquisition of high-resolution solid-state NMR spectra of quadrupolar nuclei with half-integer spin quantum number. Satellite-transition MAS (STMAS) offers an approach that employs only conventional MAS hardware and can yield substantial signal enhancements over the widely used multiple-quantum MAS (MQMAS) experiment. However, the presence of the first-order quadrupolar interaction in the satellite transitions imposes the requirement of a high degree of accuracy in the setting of the magic angle on the NMR probehead. The first-order quadrupolar interaction is only fully removed if the sample spinning angle, χ, equals cos-1(1/ 3) exactly and rotor synchronization is performed. The required level of accuracy is difficult to achieve experimentally, particularly when the quadrupolar interaction is large. If the magic angle is not set correctly, the first-order splitting is reintroduced and the spectral resolution is severely compromised. Recently, we have demonstrated a novel STMAS method (SCAM-STMAS) that is self-compensated for angle missets of up to ±1° via coherence transfer between the two different satellite transitions ST +( mI=+3/2↔+1/2) and ST -( mI=-1/2↔-3/2) midway through the t1 period. In this work we describe in more detail the implementation of SCAM-STMAS and demonstrate its wider utility through 23Na ( I=3/2), 87Rb ( I=3/2), 27Al ( I=5/2), and 59Co ( I=7/2) NMR. We discuss linewidths in SCAM-STMAS and the limits over which angle-misset compensation is achieved and we demonstrate that SCAM-STMAS is more tolerant of temporary spinning rate fluctuations than STMAS, resulting in less " t1 noise" in the two-dimensional spectrum. In addition, alternative correlation experiments, for example involving the use of double-quantum coherences, that similarly display self-compensation for angle misset are investigated. The use of SCAM-STMAS is also considered in systems where other high-order interactions, such as third

  3. Indirectly detected chemical shift correlation NMR spectroscopy in solids under fast magic angle spinning

    SciTech Connect

    Mao, Kanmi

    2011-01-01

    The development of fast magic angle spinning (MAS) opened up an opportunity for the indirect detection of insensitive low-γ nuclei (e.g., 13C and 15N) via the sensitive high-{gamma} nuclei (e.g., 1H and 19F) in solid-state NMR, with advanced sensitivity and resolution. In this thesis, new methodology utilizing fast MAS is presented, including through-bond indirectly detected heteronuclear correlation (HETCOR) spectroscopy, which is assisted by multiple RF pulse sequences for 1H-1H homonuclear decoupling. Also presented is a simple new strategy for optimization of 1H-1H homonuclear decoupling. As applications, various classes of materials, such as catalytic nanoscale materials, biomolecules, and organic complexes, are studied by combining indirect detection and other one-dimensional (1D) and two-dimensional (2D) NMR techniques. Indirectly detected through-bond HETCOR spectroscopy utilizing refocused INEPT (INEPTR) mixing was developed under fast MAS (Chapter 2). The time performance of this approach in 1H detected 2D 1H{l_brace}13C{r_brace} spectra was significantly improved, by a factor of almost 10, compared to the traditional 13C detected experiments, as demonstrated by measuring naturally abundant organic-inorganic mesoporous hybrid materials. The through-bond scheme was demonstrated as a new analytical tool, which provides complementary structural information in solid-state systems in addition to through-space correlation. To further benefit the sensitivity of the INEPT transfer in rigid solids, the combined rotation and multiple-pulse spectroscopy (CRAMPS) was implemented for homonuclear 1H decoupling under fast MAS (Chapter 3). Several decoupling schemes (PMLG5m$\\bar{x}$, PMLG5mm$\\bar{x}$x and SAM3) were analyzed to maximize the performance of through-bond transfer based

  4. Permanent magnet assembly producing a strong tilted homogeneous magnetic field: towards magic angle field spinning NMR and MRI.

    PubMed

    Sakellariou, Dimitris; Hugon, Cédric; Guiga, Angelo; Aubert, Guy; Cazaux, Sandrine; Hardy, Philippe

    2010-12-01

    We introduce a cylindrical permanent magnet design that generates a homogeneous and strong magnetic field having an arbitrary inclination with respect to the axis of the cylinder. The analytical theory of 3 D magnetostatics has been applied to this problem, and a hybrid magnet structure has been designed. This structure contains two magnets producing a longitudinal and transverse component for the magnetic field, whose amplitudes and homogeneities can be fully controlled by design. A simple prototype has been constructed using inexpensive small cube magnets, and its magnetic field has been mapped using Hall and NMR probe sensors. This magnet can, in principle, be used for magic angle field spinning NMR and MRI experiments allowing for metabolic chemical shift profiling in small living animals. PMID:20891027

  5. Nondestructive high-resolution solid-state NMR of rotating thin films at the magic-angle.

    PubMed

    Inukai, Munehiro; Noda, Yasuto; Takeda, Kazuyuki

    2011-12-01

    We present a new approach to nondestructive magic-angle spinning (MAS) nuclear magnetic resonance (NMR) for thin films. In this scheme, the sample put on the top of a rotor is spun using the conventional MAS system, and the NMR signals are detected with an additional coil. Stable spinning of disk-shaped samples with diameters of 7 mm and 12 mm at 14.2 and 7 kHz are feasible. We present 7Li MAS NMR experiments of a thin-film sample of LiCoO2 with a thickness of 200 nm. Taking advantage of the nondestructive feature of the experiment, we also demonstrate ex situ experiments, by tracing conformation change upon annealing for various durations. This approach opens the door for in situ MAS NMR of thin-film devices as well. PMID:21958755

  6. Magic angle spinning NMR investigation of influenza A M2(18-60): support for an allosteric mechanism of inhibition.

    PubMed

    Andreas, Loren B; Eddy, Matthew T; Pielak, Rafal M; Chou, James; Griffin, Robert G

    2010-08-18

    The tetrameric M2 proton channel from influenza A virus conducts protons at low pH and is inhibited by aminoadamantyl drugs such as amantadine and rimantadine (Rmt). We report magic angle spinning NMR spectra of POPC and DPhPC membrane-embedded M2(18-60), both apo and in the presence of Rmt. Similar line widths in the spectra of apo and bound M2 indicate that Rmt does not have a significant impact on the dynamics or conformational heterogeneity of this construct. Substantial chemical shift changes for many residues in the transmembrane region support an allosteric mechanism of inhibition. An Rmt titration supports a binding stoichiometry of >1 Rmt molecule per channel and shows that nonspecific binding or changes in membrane composition are unlikely sources of the chemical shift changes. In addition, doubling of spectral lines in all of the observed samples provides evidence that the channel assembles with twofold symmetry. PMID:20698642

  7. Nondestructive high-resolution solid-state NMR of rotating thin films at the magic-angle

    NASA Astrophysics Data System (ADS)

    Inukai, Munehiro; Noda, Yasuto; Takeda, Kazuyuki

    2011-12-01

    We present a new approach to nondestructive magic-angle spinning (MAS) nuclear magnetic resonance (NMR) for thin films. In this scheme, the sample put on the top of a rotor is spun using the conventional MAS system, and the NMR signals are detected with an additional coil. Stable spinning of disk-shaped samples with diameters of 7 mm and 12 mm at 14.2 and 7 kHz are feasible. We present 7Li MAS NMR experiments of a thin-film sample of LiCoO 2 with a thickness of 200 nm. Taking advantage of the nondestructive feature of the experiment, we also demonstrate ex situ experiments, by tracing conformation change upon annealing for various durations. This approach opens the door for in situ MAS NMR of thin-film devices as well.

  8. Experimental study of resolution of proton chemical shifts in solids: Combined multiple pulse NMR and magic-angle spinning

    SciTech Connect

    Ryan, L.M.; Taylor, R.E.; Paff, A.J.; Gerstein, B.C.

    1980-01-01

    High-resolution nuclear magnetic resonance spectra of protons in rigid, randomly oriented solids have been measured using combined homonuclear dipolar decoupling (via multiple pulse techniques) and attenuation of chemical shift anisotropies (via magic-angle sample spinning). Under those conditions, isotropic proton chemical shifts were recorded for a variety of chemical species, with individual linewidths varying from about 55 to 110 Hz (1--2 ppm). Residual line broadening was due predominately to (i) magnetic-field instability and inhomogeneity, (ii) unresolved proton--proton spin couplings, (iii) chemical shift dispersion, (iv) residual dipolar broadening, and (v) lifetime broadening under the multiple pulse sequences used. The magnitudes of those effects and the current limits of resolution for this experiment in our spectrometer have been investigated. The compounds studied included organic solids (4, 4'-dimethylbenzophenone, 2, 6-dimethylbenzoic acid, and aspirin), polymers (polystyrene and polymethylmethacrylate), and the vitrain portion of a bituminous coal.

  9. Two-dimensional (13)C-(13)C correlation spectroscopy with magic angle spinning and dynamic nuclear polarization.

    PubMed

    Rosay, Melanie; Weis, Volker; Kreischer, Kenneth E; Temkin, Richard J; Griffin, Robert G

    2002-04-01

    The sensitivity of solid-state NMR experiments can be enhanced with dynamic nuclear polarization (DNP), a technique that transfers the high Boltzmann polarization of unpaired electrons to nuclei. Signal enhancements of up to 23 have been obtained for magic angle spinning (MAS) experiments at 5 T and 85-90 K using a custom-designed high-power gyrotron. The extended stability of MAS/DNP experiments at low temperature is demonstrated with (1)H-driven (13)C spin-diffusion experiments on the amino acid proline. These (13)C-(13)C chemical shift correlation spectra are the first two-dimensional MAS/DNP experiments performed at high field (>1.4 T). PMID:11916398

  10. Molecular orientational dynamics in solid C70: Investigation by one- and two-dimensional magic angle spinning nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Tycko, R.; Dabbagh, G.; Vaughan, G. B. M.; Heiney, P. A.; Strongin, R. M.; Cichy, M. A.; Smith, A. B., III

    1993-11-01

    We present the results of 13C nuclear magnetic resonance (NMR) measurements that probe molecular orientational dynamics in solid C70 in the temperature range 223-343 K. Orientational dynamics affect the NMR line shapes and spin-lattice relaxation rates by modulating the 13C chemical shift anisotropy (CSA). Motionally averaged CSA line shapes, determined from both one-dimensional and two-dimensional magic angle spinning NMR spectra, and relaxation rates are determined for each of the five inequivalent carbon sites in the C70 molecule. Comparisons of the results for the five sites provide evidence for rapid uniaxial molecular reorientation in the monoclinic (T≤280 K) and rhombohedral (280≤T≤330 K) phases and rapid isotropic reorientation in the face-centered cubic (T≥330 K) phase. The orientational correlation time is roughly 2 ns at 250 K and of the order of 5 ps at 340 K.

  11. Biochemical classification of kidney carcinoma biopsy samples using magic-angle-spinning 1H nuclear magnetic resonance spectroscopy.

    PubMed

    Moka, D; Vorreuther, R; Schicha, H; Spraul, M; Humpfer, E; Lipinski, M; Foxall, P J; Nicholson, J K; Lindon, J C

    1998-05-01

    High resolution 1H nuclear magnetic resonance (NMR) spectra using spinning at the magic angle (1H MAS NMR) have been obtained on intact normal and pathological kidney tissue samples from patients undergoing surgery for renal cell carcinoma (RCC). The spectra were measured on ca. 80 mg samples and provided high resolution 1H NMR spectra in which effects of dipolar couplings, chemical shift anisotropy and magnetic susceptibility differences are minimised thus yielding high spectral resolution. Conventional one-dimensional and spin-echo spectra and two-dimensional J-resolved, TOCSY and 1H-13C HMQC spectra were also measured on selected samples and these allowed the assignment of resonances of endogenous substances comprising both cytosolic and membrane components. The tumour tissues were characterised principally by an increased lipid content. These are the first reported results on human tumour tissues using this technique and the approach offers potential for the rapid classification of different types of tumour tissue. PMID:9608434

  12. Resonance Assignments and Secondary Structure Analysis of Dynein Light Chain 8 by Magic-angle Spinning NMR Spectroscopy

    SciTech Connect

    Sun, Shangjin; Butterworth, Andrew H.; Paramasivam, Sivakumar; Yan, Si; Lightcap, Christine M.; Williams, John C.; Polenova, Tatyana E.

    2011-08-04

    Dynein light chain LC8 is the smallest subunit of the dynein motor complex and has been shown to play important roles in both dynein-dependent and dynein-independent physiological functions via its interaction with a number of its binding partners. It has also been linked to pathogenesis including roles in viral infections and tumorigenesis. Structural information for LC8-target proteins is critical to understanding the underlying function of LC8 in these complexes. However, some LC8-target interactions are not amenable to structural characterization by conventional structural biology techniques owing to their large size, low solubility, and crystallization difficulties. Here, we report magic-angle spinning (MAS) NMR studies of the homodimeric apo-LC8 protein as a first effort in addressing more complex, multi-partner, LC8-based protein assemblies. We have established site-specific backbone and side-chain resonance assignments for the majority of the residues of LC8, and show TALOS+-predicted torsion angles ø and ψ in close agreement with most residues in the published LC8 crystal structure. Data obtained through these studies will provide the first step toward using MAS NMR to examine the LC8 structure, which will eventually be used to investigate protein–protein interactions in larger systems that cannot be determined by conventional structural studies.

  13. (1)H and (13)C magic-angle spinning nuclear magnetic resonance studies of the chicken eggshell.

    PubMed

    Pisklak, Dariusz Maciej; Szeleszczuk, Lukasz; Wawer, Iwona

    2012-12-19

    The chicken eggshell, a product of biomineralization, contains inorganic and organic substances whose content changes during the incubation process. Bloch-decay (BD) (1)H, (13)C, and cross-polarization (CP) (13)C nuclear magnetic resonance (NMR) spectra of chicken eggshells were acquired under magic-angle spinning (MAS). Variable contact time (13)C CP MAS NMR experiments revealed the signals of carbonyl groups from organic and inorganic compounds. In the (13)C BD NMR spectra, a single peak at 168.1 ppm was detected, whereas in the (1)H BD spectra, the signals from water and the bicarbonate ion were assigned. A simultaneous decrease of the water signal in the (1)H MAS NMR spectra and an increase of the carbonate ion signal in the (13)C CP MAS NMR spectra of eggshells collected during the incubation period indicate the substitution of calcium ions by hydrogen ions in the calcium carbonate crystalline phase during the incubation of an egg. PMID:23157303

  14. Discrimination of Basal Cell Carcinoma from Normal Skin Tissue Using High-Resolution Magic Angle Spinning 1H NMR Spectroscopy

    PubMed Central

    Mun, Je-Ho; Lee, Heonho; Yoon, Dahye; Kim, Byung-Soo; Kim, Moon-Bum; Kim, Shukmann

    2016-01-01

    High-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy is a useful tool for investigating the metabolism of various cancers. Basal cell carcinoma (BCC) is the most common skin cancer. However, to our knowledge, data on metabolic profiling of BCC have not been reported in the literature. The objective of the present study was to investigate the metabolic profiling of cutaneous BCC using HR-MAS 1H NMR spectroscopy. HR-MAS 1H NMR spectroscopy was used to analyze the metabolite profile and metabolite intensity of histopathologically confirmed BCC tissues and normal skin tissue (NST) samples. The metabolic intensity normalized to the total spectral intensities in BCC and NST was compared, and multivariate analysis was performed with orthogonal partial least-squares discriminant analysis (OPLS-DA). P values < 0.05 were considered statistically significant. Univariate analysis revealed 9 metabolites that showed statistically significant difference between BCC and NST. In multivariate analysis, the OPLS-DA models built with the HR-MAS NMR metabolic profiles revealed a clear separation of BCC from NST. The receiver operating characteristic curve generated from the results revealed an excellent discrimination of BCC from NST with an area under the curve (AUC) value of 0.961. The present study demonstrated that the metabolite profile and metabolite intensity differ between BCC and NST, and that HR-MAS 1H NMR spectroscopy can be a valuable tool in the diagnosis of BCC. PMID:26934749

  15. Evaluation of Cancer Metabolomics Using ex vivo High Resolution Magic Angle Spinning (HRMAS) Magnetic Resonance Spectroscopy (MRS)

    PubMed Central

    Fuss, Taylor L.; Cheng, Leo L.

    2016-01-01

    According to World Health Organization (WHO) estimates, cancer is responsible for more deaths than all coronary heart disease or stroke worldwide, serving as a major public health threat around the world. High resolution magic angle spinning (HRMAS) magnetic resonance spectroscopy (MRS) has demonstrated its usefulness in the identification of cancer metabolic markers with the potential to improve diagnosis and prognosis for the oncology clinic, due partially to its ability to preserve tissue architecture for subsequent histological and molecular pathology analysis. Capable of the quantification of individual metabolites, ratios of metabolites, and entire metabolomic profiles, HRMAS MRS is one of the major techniques now used in cancer metabolomic research. This article reviews and discusses literature reports of HRMAS MRS studies of cancer metabolomics published between 2010 and 2015 according to anatomical origins, including brain, breast, prostate, lung, gastrointestinal, and neuroendocrine cancers. These studies focused on improving diagnosis and understanding patient prognostication, monitoring treatment effects, as well as correlating with the use of in vivo MRS in cancer clinics. PMID:27011205

  16. Variable temperature system using vortex tube cooling and fiber optic temperature measurement for low temperature magic angle spinning NMR.

    PubMed

    Martin, Rachel W; Zilm, Kurt W

    2004-06-01

    We describe the construction and operation of a variable temperature (VT) system for a high field fast magic angle spinning (MAS) probe. The probe is used in NMR investigations of biological macromolecules, where stable setting and continuous measurement of the temperature over periods of several days are required in order to prevent sample overheating and degradation. The VT system described is used at and below room temperature. A vortex tube is used to provide cooling in the temperature range of -20 to 20 degrees C, while a liquid nitrogen-cooled heat exchanger is used below -20 degrees C. Using this arrangement, the lowest temperature that is practically achievable is -140 degrees C. Measurement of the air temperature near the spinning rotor is accomplished using a fiber optic thermometer that utilizes the temperature dependence of the absorption edge of GaAs. The absorption edge of GaAs also has a magnetic field dependence that we have measured and corrected for. This dependence was calibrated at several field strengths using the well-known temperature dependence of the (1)H chemical shift difference of the protons in methanol. PMID:15140428

  17. Closed-cycle cold helium magic-angle spinning for sensitivity-enhanced multi-dimensional solid-state NMR

    NASA Astrophysics Data System (ADS)

    Matsuki, Yoh; Nakamura, Shinji; Fukui, Shigeo; Suematsu, Hiroto; Fujiwara, Toshimichi

    2015-10-01

    Magic-angle spinning (MAS) NMR is a powerful tool for studying molecular structure and dynamics, but suffers from its low sensitivity. Here, we developed a novel helium-cooling MAS NMR probe system adopting a closed-loop gas recirculation mechanism. In addition to the sensitivity gain due to low temperature, the present system has enabled highly stable MAS (vR = 4-12 kHz) at cryogenic temperatures (T = 35-120 K) for over a week without consuming helium at a cost for electricity of 16 kW/h. High-resolution 1D and 2D data were recorded for a crystalline tri-peptide sample at T = 40 K and B0 = 16.4 T, where an order of magnitude of sensitivity gain was demonstrated versus room temperature measurement. The low-cost and long-term stable MAS strongly promotes broader application of the brute-force sensitivity-enhanced multi-dimensional MAS NMR, as well as dynamic nuclear polarization (DNP)-enhanced NMR in a temperature range lower than 100 K.

  18. Low-temperature dynamic nuclear polarization with helium-cooled samples and nitrogen-driven magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Thurber, Kent; Tycko, Robert

    2016-03-01

    We describe novel instrumentation for low-temperature solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS), focusing on aspects of this instrumentation that have not been described in detail in previous publications. We characterize the performance of an extended interaction oscillator (EIO) microwave source, operating near 264 GHz with 1.5 W output power, which we use in conjunction with a quasi-optical microwave polarizing system and a MAS NMR probe that employs liquid helium for sample cooling and nitrogen gas for sample spinning. Enhancement factors for cross-polarized 13C NMR signals in the 100-200 range are demonstrated with DNP at 25 K. The dependences of signal amplitudes on sample temperature, as well as microwave power, polarization, and frequency, are presented. We show that sample temperatures below 30 K can be achieved with helium consumption rates below 1.3 l/h. To illustrate potential applications of this instrumentation in structural studies of biochemical systems, we compare results from low-temperature DNP experiments on a calmodulin-binding peptide in its free and bound states.

  19. Solid state nuclear magnetic resonance with magic-angle spinning and dynamic nuclear polarization below 25 K

    NASA Astrophysics Data System (ADS)

    Thurber, Kent R.; Potapov, Alexey; Yau, Wai-Ming; Tycko, Robert

    2013-01-01

    We describe an apparatus for solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS) at 20-25 K and 9.4 Tesla. The MAS NMR probe uses helium to cool the sample space and nitrogen gas for MAS drive and bearings, as described earlier [1], but also includes a corrugated waveguide for transmission of microwaves from below the probe to the sample. With a 30 mW circularly polarized microwave source at 264 GHz, MAS at 6.8 kHz, and 21 K sample temperature, greater than 25-fold enhancements of cross-polarized 13C NMR signals are observed in spectra of frozen glycerol/water solutions containing the triradical dopant DOTOPA-TEMPO when microwaves are applied. As demonstrations, we present DNP-enhanced one-dimensional and two-dimensional 13C MAS NMR spectra of frozen solutions of uniformly 13C-labeled L-alanine and melittin, a 26-residue helical peptide that we have synthesized with four uniformly 13C-labeled amino acids.

  20. Direct determination of phosphate sugars in biological material by (1)H high-resolution magic-angle-spinning NMR spectroscopy.

    PubMed

    Diserens, Gaëlle; Vermathen, Martina; Gjuroski, Ilche; Eggimann, Sandra; Precht, Christina; Boesch, Chris; Vermathen, Peter

    2016-08-01

    The study aim was to unambiguously assign nucleotide sugars, mainly UDP-X that are known to be important in glycosylation processes as sugar donors, and glucose-phosphates that are important intermediate metabolites for storage and transfer of energy directly in spectra of intact cells, as well as in skeletal muscle biopsies by (1)H high-resolution magic-angle-spinning (HR-MAS) NMR. The results demonstrate that sugar phosphates can be determined quickly and non-destructively in cells and biopsies by HR-MAS, which may prove valuable considering the importance of phosphate sugars in cell metabolism for nucleic acid synthesis. As proof of principle, an example of phosphate-sugar reaction and degradation kinetics after unfreezing the sample is shown for a cardiac muscle, suggesting the possibility to follow by HR-MAS NMR some metabolic pathways. Graphical abstract Glucose-phosphate sugars (Glc-1P and Glc-6P) detected in muscle by 1H HR-MAS NMR. PMID:27271261

  1. Solid state nuclear magnetic resonance with magic-angle spinning and dynamic nuclear polarization below 25 K

    PubMed Central

    Thurber, Kent R.; Potapov, Alexey; Yau, Wai-Ming; Tycko, Robert

    2012-01-01

    We describe an apparatus for solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS) at 20–25 K and 9.4 Tesla. The MAS NMR probe uses helium to cool the sample space and nitrogen gas for MAS drive and bearings, as described earlier (Thurber et al., J. Magn. Reson. 2008) [1], but also includes a corrugated waveguide for transmission of microwaves from below the probe to the sample. With a 30 mW circularly polarized microwave source at 264 GHz, MAS at 6.8 kHz, and 21 K sample temperature, greater than 25-fold enhancements of cross-polarized 13C NMR signals are observed in spectra of frozen glycerol/water solutions containing the triradical dopant DOTOPA-TEMPO when microwaves are applied. As demonstrations, we present DNP-enhanced one-dimensional and two-dimensional 13C MAS NMR spectra of frozen solutions of uniformly 13C-labeled L-alanine and melittin, a 26-residue helical peptide that we have synthesized with four uniformly 13C-labeled amino acids. PMID:23238592

  2. Low-temperature dynamic nuclear polarization with helium-cooled samples and nitrogen-driven magic-angle spinning.

    PubMed

    Thurber, Kent; Tycko, Robert

    2016-03-01

    We describe novel instrumentation for low-temperature solid state nuclear magnetic resonance (NMR) with dynamic nuclear polarization (DNP) and magic-angle spinning (MAS), focusing on aspects of this instrumentation that have not been described in detail in previous publications. We characterize the performance of an extended interaction oscillator (EIO) microwave source, operating near 264 GHz with 1.5 W output power, which we use in conjunction with a quasi-optical microwave polarizing system and a MAS NMR probe that employs liquid helium for sample cooling and nitrogen gas for sample spinning. Enhancement factors for cross-polarized (13)C NMR signals in the 100-200 range are demonstrated with DNP at 25K. The dependences of signal amplitudes on sample temperature, as well as microwave power, polarization, and frequency, are presented. We show that sample temperatures below 30K can be achieved with helium consumption rates below 1.3 l/h. To illustrate potential applications of this instrumentation in structural studies of biochemical systems, we compare results from low-temperature DNP experiments on a calmodulin-binding peptide in its free and bound states. PMID:26920835

  3. Closed-cycle cold helium magic-angle spinning for sensitivity-enhanced multi-dimensional solid-state NMR.

    PubMed

    Matsuki, Yoh; Nakamura, Shinji; Fukui, Shigeo; Suematsu, Hiroto; Fujiwara, Toshimichi

    2015-10-01

    Magic-angle spinning (MAS) NMR is a powerful tool for studying molecular structure and dynamics, but suffers from its low sensitivity. Here, we developed a novel helium-cooling MAS NMR probe system adopting a closed-loop gas recirculation mechanism. In addition to the sensitivity gain due to low temperature, the present system has enabled highly stable MAS (vR=4-12 kHz) at cryogenic temperatures (T=35-120 K) for over a week without consuming helium at a cost for electricity of 16 kW/h. High-resolution 1D and 2D data were recorded for a crystalline tri-peptide sample at T=40 K and B0=16.4 T, where an order of magnitude of sensitivity gain was demonstrated versus room temperature measurement. The low-cost and long-term stable MAS strongly promotes broader application of the brute-force sensitivity-enhanced multi-dimensional MAS NMR, as well as dynamic nuclear polarization (DNP)-enhanced NMR in a temperature range lower than 100 K. PMID:26302269

  4. Concentration Profiling in Rat Tissue by High-Resolution Magic-Angle Spinning NMR Spectroscopy: Investigation of a Model Drug

    PubMed Central

    Lucas, Laura H.; Wilson, Sarah F.; Lunte, Craig E.; Larive, Cynthia K.

    2008-01-01

    The utility of high-resolution magic-angle spinning (HR-MAS) NMR for studying drug delivery in whole tissues was explored by dosing female Sprague–Dawley rats with topical or injectable benzoic acid (BA). In principle, HR-MAS NMR permits the detection of both intra- and extracellular compounds. This is an advantage over the previous detection of topically applied BA using microdialysis coupled to HPLC/UV as microdialysis samples only the extracellular space. Skin and muscle samples were analyzed by 1H HR-MAS NMR, and BA levels were determined using an external standard solution added to the sample rotor. One to two percent of the BA topical dose was detected in the muscle, showing that BA penetrated through the dermal and subcutaneous layers. Since BA was not detected in the muscle in the microdialysis studies, the NMR spectra revealed the intracellular localization of BA. The amount of BA detected in muscle after subcutaneous injection correlated with the distance from the dosing site. Overall, the results suggest that HR-MAS NMR can distinguish differences in the local concentration of BA varying with tissue type, dosage method, and tissue proximity to the dosing site. The results illustrate the potential of this technique for quantitative analysis of drug delivery and distribution and the challenges to be addressed as the method is refined. PMID:15859619

  5. Satellite transitions acquired in real time by magic angle spinning (STARTMAS): ``Ultrafast'' high-resolution MAS NMR spectroscopy of spin I =3/2 nuclei

    NASA Astrophysics Data System (ADS)

    Thrippleton, Michael J.; Ball, Thomas J.; Wimperis, Stephen

    2008-01-01

    The satellite transitions acquired in real time by magic angle spinning (STARTMAS) NMR experiment combines a train of pulses with sample rotation at the magic angle to refocus the first- and second-order quadrupolar broadening of spin I =3/2 nuclei in a series of echoes, while allowing the isotropic chemical and quadrupolar shifts to evolve. The result is real-time isotropic NMR spectra at high spinning rates using conventional MAS equipment. In this paper we describe in detail how STARTMAS data can be acquired and processed with ease on commercial equipment. We also discuss the advantages and limitations of the approach and illustrate the discussion with numerical simulations and experimental data from four different powdered solids.

  6. Order-selective multiple-quantum excitation in magic-angle spinning NMR: creating triple-quantum coherences with a trilinear Hamiltonian

    NASA Astrophysics Data System (ADS)

    Edén, Mattias

    2002-12-01

    Order-selective multiple-quantum excitation in magic-angle spinning nuclear magnetic resonance is explored using a class of symmetry-based pulse sequences, denoted S Mχ. Simple rules are presented that aid the design of S Mχ schemes with certain desirable effective Hamiltonians. They are applied to construct sequences generating trilinear effective dipolar Hamiltonians, suitable for efficient excitation of triple-quantum coherences in rotating solids. The new sequences are investigated numerically and demonstrated by 1H experiments on adamantane.

  7. Solid-state dynamics in the closo-carboranes: a (11)B MAS NMR and molecular dynamics study.

    PubMed

    Ahumada, Hernán; Kurkiewicz, Teresa; Thrippleton, Michael J; Wimperis, Stephen

    2015-03-19

    This work explores the dynamic behavior of the three closo-carborane isomers (formula C2B10H12) using modern solid-state magic angle spinning (MAS) NMR techniques and relates the experimental measurements to theoretical results obtained using molecular dynamics simulations. At high temperatures and at B0 = 9.4 T, the (11)B MAS line widths are narrow (40-90 Hz) for the three isomers. The rotational correlation times (τc) calculated by molecular dynamics are on the picosecond time scale, showing a quasi-isotropic rotation at these temperatures, typical for liquid systems. For all three isomers, the values of the (11)B spin-lattice relaxation times (T1) show discontinuities as the temperature is decreased, confirming the phase changes reported in the literature. At low temperatures, the (11)B MAS spectra of all three isomers exhibit much broader lines. The simulations showed that the molecular reorientation was anisotropic around different symmetry axes for each isomer, and this was supported by the values of the reduced quadrupolar parameter PQ(eff) derived from "dynamic shift" measurements using (11)B MQMAS NMR spectroscopy. The behavior of PQ(eff) as a function of temperature for p-carborane suggests that molecular reorientation is about the C5 symmetry axis of the molecule at low temperatures, and this was supported by the molecular dynamics simulations. PMID:25710751

  8. Magic-angle-spinning NMR on solid biological systems. Analysis Of the origin of the spectral linewidths

    NASA Astrophysics Data System (ADS)

    Hemminga, M. A.; de Jager, P. A.; Krüse, J.; Lamerichs, R. M. J. N.

    Magic-angle-spinning (MAS) high-power 1H-decoupled 13C and 31P NMR has been applied to solid biological materials to obtain information about the mechanisms that determine the spectral linewidths. The line broadening in MAS 31P NMR spectra of solid tobacco mosaic virus (TMV) has been investigated by selective saturation and T2 measurements. About 90 Hz stems from homogeneous effects, whereas the inhomogeneous contribution is approximately 100 Hz. The inhomogeneous line broadening is assigned to macroscopic inhomogeneities in the sample and not to variations in the nucleotide bases along the RNA strand in TMV. It is concluded that sample preparation is of vital importance for obtaining well-resolved spectra. Under optimal preparation techniques the isotropic values of the chemical shift of the different 31P sites have been determined to obtain information about the secondary structure of the viral RNA. The chemical shift anisotropy has been determined from the relative intensities of the spinning side bands in the spectra. The chemical shift information is used to make a tentative assignment of the resonance in terms of the three structurally distinguishable phosphate groups in TMV. The origin of the linewidths in MAS NMR has been examined further by 13C NMR of approximately 10% 13C-enriched coat protein of cowpea chlorotic mottle virus, using selective excitation and saturation techniques, as well as measurements of the relaxation times T1 γ and T2. The CO resonance in the spectrum is composed of an inhomogeneous and homogeneous part with a total linewidth of 700 Hz. The homogeneous linewidth, contributing with 200 Hz, is found to arise from slow molecular motions in the solid on a millisecond timescale.

  9. Metabolic profiling of a Schistosoma mansoni infection in mouse tissues using magic angle spinning-nuclear magnetic resonance spectroscopy.

    PubMed

    Li, Jia V; Holmes, Elaine; Saric, Jasmina; Keiser, Jennifer; Dirnhofer, Stephan; Utzinger, Jürg; Wang, Yulan

    2009-04-01

    In order to enhance our understanding of physiological and pathological consequences of a patent Schistosoma mansoni infection in the mouse, we examined the metabolic responses of different tissue samples recovered from the host animal using a metabolic profiling strategy. Ten female NMRI mice were infected with approximately 80 S. mansoni cercariae each, and 10 uninfected age- and sex-matched animals served as controls. At day 74 post infection (p.i.), mice were killed and jejunum, ileum, colon, liver, spleen and kidney samples were removed. We employed (1)H magic angle spinning-nuclear magnetic resonance spectroscopy to generate tissue-specific metabolic profiles. The spectral data were analyzed using multivariate modelling methods including an orthogonal signal corrected-projection to latent structure analysis and hierarchical principal component analysis to assess the differences and/or similarities in metabolic responses between infected and non-infected control mice. Most tissues obtained from S. mansoni-infected mice were characterized by high levels of amino acids, such as leucine, isoleucine, lysine, glutamine and asparagine. High levels of membrane phospholipid metabolites, including glycerophosphoryl choline and phosphoryl choline were found in the ileum, colon, liver and spleen of infected mice. Additionally, low levels of energy-related metabolites, including lipids, glucose and glycogen were observed in ileum, spleen and liver samples of infected mice. Energy-related metabolites in the jejunum, liver and renal medulla were found to be positively correlated with S. mansoni worm burden upon dissection. These findings show that a patent S. mansoni infection causes clear disruption of metabolism in a range of tissues at a molecular level, which can be interpreted in relation to the previously reported signature in a biofluid (i.e. urine), giving further evidence of the global effect of the infection. PMID:19068218

  10. Distortional binding of transition state analogs to human purine nucleoside phosphorylase probed by magic angle spinning solid-state NMR.

    PubMed

    Vetticatt, Mathew J; Itin, Boris; Evans, Gary B; Schramm, Vern L

    2013-10-01

    Transition state analogs mimic the geometry and electronics of the transition state of enzymatic reactions. These molecules bind to the active site of the enzyme much tighter than substrate and are powerful noncovalent inhibitors. Immucillin-H (ImmH) and 4'-deaza-1'-aza-2'-deoxy-9-methylene Immucillin-H (DADMe-ImmH) are picomolar inhibitors of human purine nucleoside phosphorylase (hPNP). Although both molecules are electronically similar to the oxocarbenium-like dissociative hPNP transition state, DADMe-ImmH is more potent than ImmH. DADMe-ImmH captures more of the transition state binding energy by virtue of being a closer geometric match to the hPNP transition state than ImmH. A consequence of these similarities is that the active site of hPNP exerts greater distortional forces on ImmH than on DADMe-ImmH to "achieve" the hPNP transition state geometry. By using magic angle spinning solid-state NMR to investigate stable isotope-labeled ImmH and DADMe-ImmH, we have explored the difference in distortional binding of these two inhibitors to hPNP. High-precision determinations of internuclear distances from NMR recoupling techniques, rotational echo double resonance, and rotational resonance, have provided unprecedented atomistic insight into the geometric changes that occur upon binding of transition state analogs. We conclude that hPNP stabilizes conformations of these chemically distinct analogs having distances between the cation and leaving groups resembling those of the known transition state. PMID:24043827

  11. Live-cell high resolution magic angle spinning magnetic resonance spectroscopy for in vivo analysis of Pseudomonas aeruginosa metabolomics.

    PubMed

    Righi, Valeria; Constantinou, Caterina; Kesarwani, Meenu; Rahme, Laurence G; Tzika, Aria A

    2013-09-01

    Pseudomonas aeruginosa (PA) is a pathogenic gram-negative bacterium that is widespread in nature, inhabiting soil, water, plants and animals. PA is a prevalent cause of deleterious human infections, particularly in patients whose host defense mechanisms have been compromised. Metabolomics is an important tool used to study host-pathogen interactions and to identify novel therapeutic targets and corresponding compounds. The aim of the present study was to report the metabolic profile of live PA bacteria using in vivo high-resolution magic angle spinning (HRMAS) nuclear magnetic resonance spectroscopy (NMR), in combination with 1- and 2-dimensional HRMAS NMR. This methodology provides a new and powerful technique to rapidly interrogate the metabolome of intact bacterial cells and has several advantages over traditional techniques that identify metabolome components from disrupted cells. Furthermore, application of multidimensional HRMAS NMR, in combination with the novel technique total through-Bond correlation Spectroscopy (TOBSY), is a promising approach that may be used to obtain in vivo metabolomics information from intact live bacterial cells and can mediate such analyses in a short period of time. Moreover, HRMAS (1)H NMR enables the investigation of the associations between metabolites and cell processes. In the present study, we detected and quantified several informative metabolic molecules in live PA cells, including N-acetyl, betaine, citrulline, alanine and glycine, which are important in peptidoglycan synthesis. The results provided a complete metabolic profile of PA for future studies of PA clinical isolates and mutants. In addition, this in vivo NMR biomedical approach might have clinical utility and should prove useful in gene function validation, the study of pathogenetic mechanisms, the classification of microbial strains into functional/clinical groups, the testing of anti-bacterial agents and the determination of metabolic profiles of bacterial

  12. Characterization of metabolites in infiltrating gliomas using ex vivo ¹H high-resolution magic angle spinning spectroscopy.

    PubMed

    Elkhaled, Adam; Jalbert, Llewellyn; Constantin, Alexandra; Yoshihara, Hikari A I; Phillips, Joanna J; Molinaro, Annette M; Chang, Susan M; Nelson, Sarah J

    2014-05-01

    Gliomas are routinely graded according to histopathological criteria established by the World Health Organization. Although this classification can be used to understand some of the variance in the clinical outcome of patients, there is still substantial heterogeneity within and between lesions of the same grade. This study evaluated image-guided tissue samples acquired from a large cohort of patients presenting with either new or recurrent gliomas of grades II-IV using ex vivo proton high-resolution magic angle spinning spectroscopy. The quantification of metabolite levels revealed several discrete profiles associated with primary glioma subtypes, as well as secondary subtypes that had undergone transformation to a higher grade at the time of recurrence. Statistical modeling further demonstrated that these metabolomic profiles could be differentially classified with respect to pathological grading and inter-grade conversions. Importantly, the myo-inositol to total choline index allowed for a separation of recurrent low-grade gliomas on different pathological trajectories, the heightened ratio of phosphocholine to glycerophosphocholine uniformly characterized several forms of glioblastoma multiforme, and the onco-metabolite D-2-hydroxyglutarate was shown to help distinguish secondary from primary grade IV glioma, as well as grade II and III from grade IV glioma. These data provide evidence that metabolite levels are of interest in the assessment of both intra-grade and intra-lesional malignancy. Such information could be used to enhance the diagnostic specificity of in vivo spectroscopy and to aid in the selection of the most appropriate therapy for individual patients. PMID:24596146

  13. Application of High-Resolution Magic-Angle Spinning NMR Spectroscopy to Define the Cell Uptake of MRI Contrast Agents

    NASA Astrophysics Data System (ADS)

    Calabi, Luisella; Alfieri, Goffredo; Biondi, Luca; De Miranda, Mario; Paleari, Lino; Ghelli, Stefano

    2002-06-01

    A new method, based on proton high-resolution magic-angle spinning ( 1H HR-MAS) NMR spectroscopy, has been employed to study the cell uptake of magnetic resonance imaging contrast agents (MRI-CAs). The method was tested on human red blood cells (HRBC) and white blood cells (HWBC) by using three gadolinium complexes, widely used in diagnostics, Gd-BOPTA, Gd-DTPA, and Gd-DOTA, and the analogous complexes obtained by replacing Gd(III) with Dy(III), Nd(III), and Tb(III) (i.e., complexes isostructural to the ones of gadolinium but acting as shift agents). The method is based on the evaluation of the magnetic effects, line broadening, or induced lanthanide shift (LIS) caused by these complexes on NMR signals of intra- and extracellular water. Since magnetic effects are directly linked to permeability, this method is direct. In all the tests, these magnetic effects were detected for the extracellular water signal only, providing a direct proof that these complexes are not able to cross the cell membrane. Line broadening effects (i.e., the use of gadolinium complexes) only allow qualitative evaluations. On the contrary, LIS effects can be measured with high precision and they can be related to the concentration of the paramagnetic species in the cellular compartments. This is possible because the HR-MAS technique provides the complete elimination of bulk magnetic susceptibility (BMS) shift and the differentiation of extra- and intracellular water signals. Thus with this method, the rapid quantification of the MRI-CA amount inside and outside the cells is actually feasible.

  14. Magic-Angle Spinning Solid-State NMR Spectroscopy of Nanodisc– Embedded Human CYP3A4†

    PubMed Central

    Kijac, Aleksandra; Li, Ying; Sligar, Stephen G.; Rienstra, Chad M.

    2008-01-01

    Cytochrome P450 (CYP) 3A4 contributes to the metabolism of approximately 50% of commercial drugs by oxidizing a large number of structurally diverse substrates. Like other endoplasmic reticulum-localized P450s, CYP3A4 contains a membrane-anchoring N-terminal helix and a significant number of hydrophobic domains, important for the interaction between CYP3A4 and the membrane. Although the membrane affects specificity of CYP3A4 ligand binding, the structural details of the interaction have not been revealed so far because x-ray crystallography studies are available only for the soluble domain of CYP3A4. Here we report sample preparation and initial magic-angle spinning (MAS) solid-state NMR (SSNMR) of CYP3A4 (Δ3−12) embedded in a nanoscale membrane bilayer, or Nanodisc. The growth protocol yields ∼2.5 mg of the enzymatically active, uniformly 13C, 15N-enriched CYP3A4 from a liter of growth medium. Polyethylene glycol 3350-precipitated CYP3A4 in Nanodiscs yields spectra of high resolution and sensitivity, consistent with a folded, homogeneous protein. CYP3A4 in Nanodiscs remains enzymatically active throughout the precipitation protocol as monitored by bromocriptine binding. The 13C line widths measured from 13C-13C 2D chemical shift correlation spectra are ∼0.5 ppm. The secondary structure distribution within several amino acid types determined from 13C chemical shifts is consistent with the ligand-free x-ray structures. These results demonstrate that MAS SSNMR can be performed on Nanodisc-embedded membrane proteins in a folded, active state. The combination of SSNMR and Nanodisc methodologies opens up new possibilities for obtaining structural information on CYP3A4 and other integral membrane proteins with full retention of functionality. PMID:17985934

  15. High-resolution paramagnetically enhanced solid-state NMR spectroscopy of membrane proteins at fast magic angle spinning.

    PubMed

    Ward, Meaghan E; Wang, Shenlin; Krishnamurthy, Sridevi; Hutchins, Howard; Fey, Michael; Brown, Leonid S; Ladizhansky, Vladimir

    2014-01-01

    Magic angle spinning nuclear magnetic resonance (MAS NMR) is well suited for the study of membrane proteins in membrane mimetic and native membrane environments. These experiments often suffer from low sensitivity, due in part to the long recycle delays required for magnetization and probe recovery, as well as detection of low gamma nuclei. In ultrafast MAS experiments sensitivity can be enhanced through the use of low power sequences combined with paramagnetically enhanced relaxation times to reduce recycle delays, as well as proton detected experiments. In this work we investigate the sensitivity of (13)C and (1)H detected experiments applied to 27 kDa membrane proteins reconstituted in lipids and packed in small 1.3 mm MAS NMR rotors. We demonstrate that spin diffusion is sufficient to uniformly distribute paramagnetic relaxation enhancement provided by either covalently bound or dissolved CuEDTA over 7TM alpha helical membrane proteins. Using paramagnetic enhancement and low power decoupling in carbon detected experiments we can recycle experiments ~13 times faster than under traditional conditions. However, due to the small sample volume the overall sensitivity per unit time is still lower than that seen in the 3.2 mm probe. Proton detected experiments, however, showed increased efficiency and it was found that the 1.3 mm probe could achieve sensitivity comparable to that of the 3.2 mm in a given amount of time. This is an attractive prospect for samples of limited quantity, as this allows for a reduction in the amount of protein that needs to be produced without the necessity for increased experimental time. PMID:24338448

  16. 19F Magic angle spinning NMR reporter molecules: empirical measures of surface shielding, polarisability and H-bonding.

    PubMed

    Budarin, Vitaliy L; Clark, James H; Deswarte, Fabien E I; Mueller, Karl T; Tavener, Stewart J

    2007-06-14

    Magic Angle Spinning (MAS) (19)F NMR spectra have been obtained and chemical shifts measured for 37 molecules in the gas phase and adsorbed on the surfaces of six common materials: octadecyl- and octyl-functionalised chromatography silicas, Kieselgel 100 silica, Brockmann neutral alumina, Norit activated charcoal and 3-(1-piperidino)propyl functionalised silica. From these six surfaces, octadecyl-silica is selected as a non-polar reference to which the others are compared. The change in chemical shift of a fluorine nucleus within a molecule on adsorption to a surface from the gas phase, Deltadelta(gas)(surface), is described by the empirical relationship: Deltadelta(gas)(surface) = delta(s) + (alpha(s)+pi(s))/alpha(r) (Deltadelta(gas)(reference) - delta(r)) + delta(HBA) + delta(HBD), where delta(s) and delta(r) are constants that describe the chemical shift induced by the electromagnetic field of the surface under investigation and reference surface, alpha(s) and alpha(r) are the relative surface polarisability for the surface and reference, pi(s) is an additional contribution to the surface polarisabilities due to its ability to interact with aromatic molecules, and delta(HBA) and delta(HBD) are measurements of the hydrogen acceptor and donor properties of the surface. These empirical parameters are measured for the surfaces under study. Silica and alumina are found to undergo specific interactions with aromatic reporter molecules and both accept and donate H-bonds. Activated charcoal was found to have an extreme effect on shielding but no specific interactions with the adsorbed molecules. 3-(1-Piperidino)propyl functionalised silica exhibits H-bond acceptor ability, but does not donate H-bonds. PMID:17487325

  17. Intratumoral Agreement of High-Resolution Magic Angle Spinning Magnetic Resonance Spectroscopic Profiles in the Metabolic Characterization of Breast Cancer

    PubMed Central

    Park, Vivian Youngjean; Yoon, Dahye; Koo, Ja Seung; Kim, Eun-Kyung; Kim, Seung Il; Choi, Ji Soo; Park, Seho; Park, Hyung Seok; Kim, Suhkmann; Kim, Min Jung

    2016-01-01

    Abstract High-resolution magic angle spinning (HR-MAS) magnetic resonance (MR) spectroscopy data may serve as a biomarker for breast cancer, with only a small volume of tissue sample required for assessment. However, previous studies utilized only a single tissue sample from each patient. The aim of this study was to investigate whether intratumoral location and biospecimen type affected the metabolic characterization of breast cancer assessed by HR-MAS MR spectroscopy This prospective study was approved by the institutional review board and informed consent was obtained. Preoperative core-needle biopsies (CNBs), central, and peripheral surgical tumor specimens were prospectively collected under ultrasound (US) guidance in 31 patients with invasive breast cancer. Specimens were assessed with HR-MAS MR spectroscopy. The reliability of metabolite concentrations was evaluated and multivariate analysis was performed according to intratumoral location and biospecimen type. There was a moderate or higher agreement between the relative concentrations of 94.3% (33 of 35) of metabolites in the center and periphery, 80.0% (28 of 35) of metabolites in the CNB and central surgical specimens, and 82.9% (29 of 35) of metabolites between all 3 specimen types. However, there was no significant agreement between the concentrations of phosphocholine (PC) and phosphoethanolamine (PE) in the center and periphery. The concentrations of several metabolites (adipate, arginine, fumarate, glutamate, PC, and PE) had no significant agreement between the CNB and central surgical specimens. In conclusion, most HR-MAS MR spectroscopic data do not differ based on intratumoral location or biospecimen type. However, some metabolites may be affected by specimen-related variables, and caution is recommended in decision-making based solely on metabolite concentrations, particularly PC and PE. Further validation through future studies is needed for the clinical implementation of these biomarkers based

  18. The mobility of chondroitin sulfate in articular and artificial cartilage characterized by 13C magic-angle spinning NMR spectroscopy.

    PubMed

    Scheidt, Holger A; Schibur, Stephanie; Magalhães, Alvicler; de Azevedo, Eduardo R; Bonagamba, Tito J; Pascui, Ovidiu; Schulz, Ronny; Reichert, Detlef; Huster, Daniel

    2010-06-01

    We have studied the molecular dynamics of one of the major macromolecules in articular cartilage, chondroitin sulfate. Applying (13)C high-resolution magic-angle spinning NMR techniques, the NMR signals of all rigid macromolecules in cartilage can be suppressed, allowing the exclusive detection of the highly mobile chondroitin sulfate. The technique is also used to detect the chondroitin sulfate in artificial tissue-engineered cartilage. The tissue-engineered material that is based on matrix producing chondrocytes cultured in a collagen gel should provide properties as close as possible to those of the natural cartilage. Nuclear relaxation times of the chondroitin sulfate were determined for both tissues. Although T(1) relaxation times are rather similar, the T(2) relaxation in tissue-engineered cartilage is significantly shorter. This suggests that the motions of chondroitin sulfate in natural and artificial cartilage are different. The nuclear relaxation times of chondroitin sulfate in natural and tissue-engineered cartilage were modeled using a broad distribution function for the motional correlation times. Although the description of the microscopic molecular dynamics of the chondroitin sulfate in natural and artificial cartilage required the identical broad distribution functions for the correlation times of motion, significant differences in the correlation times of motion that are extracted from the model indicate that the artificial tissue does not fully meet the standards of the natural ideal. This could also be confirmed by macroscopic biomechanical elasticity measurements. Nevertheless, these results suggest that NMR is a useful tool for the investigation of the quality of artificially engineered tissue. PMID:20091673

  19. Mineral Carbonation in Wet Supercritical CO2: An in situ High-Pressure Magic Angle Spinning Nuclear Magnetic Resonance Study

    NASA Astrophysics Data System (ADS)

    Turcu, R. V.; Hoyt, D. H.; Sears, J. A.; Rosso, K. M.; Felmy, A. R.; Hu, J. Z.

    2011-12-01

    Understanding the mechanisms and kinetics of mineral carbonation reactions relevant to sequestering carbon dioxide as a supercritical fluid (scCO2) in geologic formations is crucial for accurately predicting long-term storage risks. In situ probes that provide molecular-level information at geologically relevant temperatures and pressures are highly desirable and challenging to develop. Magic angle spinning nuclear magnetic resonance (MAS NMR) is a powerful tool for obtaining detailed molecular structure and dynamics information of a system regardless whether the system is in a solid, a liquid, a gaseous, a supercritical state, or a mixture thereof. However, MAS NMR under scCO2 conditions has never been realized due to the tremendous technical difficulties of achieving and maintaining high pressure within a fast spinning MAS sample rotor. In this work, we report development of a unique high pressure MAS NMR capability capable of handling fluid pressure exceeding 170 bars and temperatures up to 80°C, and its application to mineral carbonation in scCO2 under geologically relevant temperatures and pressures. Mineral carbonation reactions of the magnesium silicate mineral forsterite and the magnesium hydroxide brucite reacted with scCO2 (up to 170 bar) and containing variable content of H2O (at, below, and above saturation in scCO2) were investigated at 50 to 70°C. In situ 13C MAS NMR spectra show peaks corresponding to the reactants, intermediates, and the magnesium carbonation products in a single spectrum. For example, Figure 1 shows the reaction dynamics, i.e., the formation and conversion of reaction intermediates, i.e., HCO3- and nesquehonite, to magnesite as a function of time at 70°C. This capability offers a significant advantage over traditional ex situ 13C MAS experiments on similar systems, where, for example, CO2 and HCO3- are not directly observable.

  20. Complete protocol for slow-spinning high-resolution magic-angle spinning NMR analysis of fragile tissues.

    PubMed

    André, Marion; Dumez, Jean-Nicolas; Rezig, Lamya; Shintu, Laetitia; Piotto, Martial; Caldarelli, Stefano

    2014-11-01

    High-resolution magic-angle spinning (HR-MAS) nuclear magnetic resonance (NMR) is an essential tool to characterize a variety of semisolid systems, including biological tissues, with virtually no sample preparation. The "non-destructive" nature of NMR is typically compromised, however, by the extreme centrifugal forces experienced under conventional HR-MAS frequencies of several kilohertz. These features limit the usefulness of current HR-MAS approaches for fragile samples. Here, we introduce a full protocol for acquiring high-quality HR-MAS NMR spectra of biological tissues at low spinning rates (down to a few hundred hertz). The protocol first consists of a carefully designed sample preparation, which yields spectra without significant spinning sidebands at low spinning frequency for several types of sample holders, including the standard disposable inserts classically used in HR-MAS NMR-based metabolomics. Suppression of broad spectral features is then achieved using a modified version of the recently introduced PROJECT experiment with added water suppression and rotor synchronization, which deposits limited power in the sample and which can be suitably rotor-synchronized at low spinning rates. The performance of the slow HR-MAS NMR procedure is demonstrated on conventional (liver tissue) and very delicate (fish eggs) samples, for which the slow-spinning conditions are shown to preserve the structural integrity and to minimize intercompartmental leaks of metabolites. Taken together, these results expand the applicability and reliability of HR-MAS NMR spectroscopy. These results have been obtained at 400 and 600 MHz and suggest that high-quality slow HR-MAS spectra can be expected at higher magnetic fields using the described protocol. PMID:25286333

  1. Powder-XRD and (14) N magic angle-spinning solid-state NMR spectroscopy of some metal nitrides.

    PubMed

    Kempgens, Pierre; Britton, Jonathan

    2016-05-01

    Some metal nitrides (TiN, ZrN, InN, GaN, Ca3 N2 , Mg3 N2 , and Ge3 N4 ) have been studied by powder X-ray diffraction (XRD) and (14) N magic angle-spinning (MAS) solid-state NMR spectroscopy. For Ca3 N2 , Mg3 N2 , and Ge3 N4 , no (14) N NMR signal was observed. Low speed (νr  = 2 kHz for TiN, ZrN, and GaN; νr  = 1 kHz for InN) and 'high speed' (νr  = 15 kHz for TiN; νr  = 5 kHz for ZrN; νr  = 10 kHz for InN and GaN) MAS NMR experiments were performed. For TiN, ZrN, InN, and GaN, powder-XRD was used to identify the phases present in each sample. The number of peaks observed for each sample in their (14) N MAS solid-state NMR spectrum matches perfectly well with the number of nitrogen-containing phases identified by powder-XRD. The (14) N MAS solid-state NMR spectra are symmetric and dominated by the quadrupolar interaction. The envelopes of the spinning sidebands manifold are Lorentzian, and it is concluded that there is a distribution of the quadrupolar coupling constants Qcc 's arising from structural defects in the compounds studied. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26687421

  2. Sensitivity and resolution enhanced solid-state NMR for paramagnetic systems and biomolecules under very fast magic angle spinning.

    PubMed

    Parthasarathy, Sudhakar; Nishiyama, Yusuke; Ishii, Yoshitaka

    2013-09-17

    Recent research in fast magic angle spinning (MAS) methods has drastically improved the resolution and sensitivity of NMR spectroscopy of biomolecules and materials in solids. In this Account, we summarize recent and ongoing developments in this area by presenting (13)C and (1)H solid-state NMR (SSNMR) studies on paramagnetic systems and biomolecules under fast MAS from our laboratories. First, we describe how very fast MAS (VFMAS) at the spinning speed of at least 20 kHz allows us to overcome major difficulties in (1)H and (13)C high-resolution SSNMR of paramagnetic systems. As a result, we can enhance both sensitivity and resolution by up to a few orders of magnitude. Using fast recycling (∼ms/scan) with short (1)H T1 values, we can perform (1)H SSNMR microanalysis of paramagnetic systems on the microgram scale with greatly improved sensitivity over that observed for diamagnetic systems. Second, we discuss how VFMAS at a spinning speed greater than ∼40 kHz can enhance the sensitivity and resolution of (13)C biomolecular SSNMR measurements. Low-power (1)H decoupling schemes under VFMAS offer excellent spectral resolution for (13)C SSNMR by nominal (1)H RF irradiation at ∼10 kHz. By combining the VFMAS approach with enhanced (1)H T1 relaxation by paramagnetic doping, we can achieve extremely fast recycling in modern biomolecular SSNMR experiments. Experiments with (13)C-labeled ubiquitin doped with 10 mM Cu-EDTA demonstrate how effectively this new approach, called paramagnetic assisted condensed data collection (PACC), enhances the sensitivity. Lastly, we examine (13)C SSNMR measurements for biomolecules under faster MAS at a higher field. Our preliminary (13)C SSNMR data of Aβ amyloid fibrils and GB1 microcrystals acquired at (1)H NMR frequencies of 750-800 MHz suggest that the combined use of the PACC approach and ultrahigh fields could allow for routine multidimensional SSNMR analyses of proteins at the 50-200 nmol level. Also, we briefly discuss the

  3. Spin dynamics in the modulation frame: application to homonuclear recoupling in magic angle spinning solid-state NMR.

    PubMed

    De Paëpe, Gaël; Lewandowski, Józef R; Griffin, Robert G

    2008-03-28

    We introduce a family of solid-state NMR pulse sequences that generalizes the concept of second averaging in the modulation frame and therefore provides a new approach to perform magic angle spinning dipolar recoupling experiments. Here, we focus on two particular recoupling mechanisms-cosine modulated rotary resonance (CMpRR) and cosine modulated recoupling with isotropic chemical shift reintroduction (COMICS). The first technique, CMpRR, is based on a cosine modulation of the rf phase and yields broadband double-quantum (DQ) (13)C recoupling using >70 kHz omega(1,C)/2pi rf field for the spinning frequency omega(r)/2=10-30 kHz and (1)H Larmor frequency omega(0,H)/2pi up to 900 MHz. Importantly, for p>or=5, CMpRR recouples efficiently in the absence of (1)H decoupling. Extension to lower p values (3.5

  4. A suite of pulse sequences based on multiple sequential acquisitions at one and two radiofrequency channels for solid-state magic-angle spinning NMR studies of proteins.

    PubMed

    Sharma, Kshama; Madhu, Perunthiruthy K; Mote, Kaustubh R

    2016-08-01

    One of the fundamental challenges in the application of solid-state NMR is its limited sensitivity, yet a majority of experiments do not make efficient use of the limited polarization available. The loss in polarization in a single acquisition experiment is mandated by the need to select out a single coherence pathway. In contrast, sequential acquisition strategies can encode more than one pathway in the same experiment or recover unused polarization to supplement a standard experiment. In this article, we present pulse sequences that implement sequential acquisition strategies on one and two radiofrequency channels with a combination of proton and carbon detection to record multiple experiments under magic-angle spinning. We show that complementary 2D experiments such as [Formula: see text] and [Formula: see text] or DARR and [Formula: see text], and 3D experiments such as [Formula: see text] and [Formula: see text], or [Formula: see text] and [Formula: see text]  can be combined in a single experiment to ensure time savings of at least 40 %. These experiments can be done under fast or slow-moderate magic-angle spinning frequencies aided by windowed [Formula: see text] acquisition and homonulcear decoupling. The pulse sequence suite is further expanded by including pathways that allow the recovery of residual polarization, the so-called 'afterglow' pathways, to encode a number of pulse sequences to aid in assignments and chemical-shift mapping. PMID:27364976

  5. Slow Magic Angle Sample Spinning: A Non- or Minimally Invasive Method for High- Resolution 1H Nuclear Magnetic Resonance (NMR) Metabolic Profiling

    SciTech Connect

    Hu, Jian Z.

    2011-05-01

    High resolution 1H magic angle spinning nuclear magnetic resonance (NMR), using a sample spinning rate of several kHz or more (i.e., high resolution-magic angle spinning (hr-MAS)), is a well established method for metabolic profiling in intact tissues without the need for sample extraction. The only shortcoming with hr-MAS is that it is invasive and is thus unusable for non-destructive detections. Recently, a method called slow-MAS, using the concept of two dimensional NMR spectroscopy, has emerged as an alternative method for non- or minimal invasive metabolomics in intact tissues, including live animals, due to the slow or ultra-slow-sample spinning used. Although slow-MAS is a powerful method, its applications are hindered by experimental challenges. Correctly designing the experiment and choosing the appropriate slow-MAS method both require a fundamental understanding of the operation principles, in particular the details of line narrowing due to the presence of molecular diffusion. However, these fundamental principles have not yet been fully disclosed in previous publications. The goal of this chapter is to provide an in depth evaluation of the principles associated with slow-MAS techniques by emphasizing the challenges associated with a phantom sample consisting of glass beads and H2O, where an unusually large magnetic susceptibility field gradient is obtained.

  6. Unexpected effects of third-order cross-terms in heteronuclear spin systems under simultaneous radio-frequency irradiation and magic-angle spinning NMR

    NASA Astrophysics Data System (ADS)

    Tatton, Andrew S.; Frantsuzov, Ilya; Brown, Steven P.; Hodgkinson, Paul

    2012-02-01

    We recently noted [R. K. Harris, P. Hodgkinson, V. Zorin, J.-N. Dumez, B. Elena, L. Emsley, E. Salager, and R. Stein, Magn. Reson. Chem. 48, S103 (2010), 10.1002/mrc.2636] anomalous shifts in apparent 1H chemical shifts in experiments using 1H homonuclear decoupling sequences to acquire high-resolution 1H NMR spectra for organic solids under magic-angle spinning (MAS). Analogous effects were also observed in numerical simulations of model 13C,1H spin systems under homonuclear decoupling and involving large 13C,1H dipolar couplings. While the heteronuclear coupling is generally assumed to be efficiently suppressed by sample spinning at the magic angle, we show that under conditions typically used in solid-state NMR, there is a significant third-order cross-term from this coupling under the conditions of simultaneous MAS and homonuclear decoupling for spins directly bonded to 1H. This term, which is of the order of 100 Hz under typical conditions, explains the anomalous behaviour observed on both 1H and 13C spins, including the fast dephasing observed in 13C{1H} heteronuclear spin-echo experiments under 1H homonuclear decoupling. Strategies for minimising the impact of this effect are also discussed.

  7. Slow magic-angle rotation 13C NMR studies of solid phosphonium iodides. The interplay of dipolar, shielding, and indirect coupling tensors

    NASA Astrophysics Data System (ADS)

    Harris, Robin K.; Packer, Kenneth J.; Thayer, Ann M.

    High-resolution 13C NMR spectra were recorded for solid [Me 2Ph 2P] +I - and [Me 3PhP] +I - using high-power decoupling, cross-polarization, and magic-angle rotation. Spectra of the ipso carbon, obtained with the nonquaternary suppression (dipolar dephasing) pulse sequence, show an unequal distribution intensity of spinning sidebands for the two peaks split by the isotropic coupling constant 1JPC. This effect is traced to the joint influence of (P, C) dipolar coupling and 13C shielding anisotropy. The existence of scalar coupling enables magic-angle rotation to distinguish the two subspectra which are present. Analysis of the sideband patterns yields values of the NMR parameters. Under certain assumptions, including that the axis of greatest shielding is perpendicular to the PC bond, it is shown that 1JPC is positive. In contrast to traditional methods of determining signs, this conclusion does not rely on knowledge of signs of other coupling constants.

  8. Electrical and ionic conductivity effects on magic-angle spinning nuclear magnetic resonance parameters of CuI

    NASA Astrophysics Data System (ADS)

    Yesinowski, James P.; Ladouceur, Harold D.; Purdy, Andrew P.; Miller, Joel B.

    2010-12-01

    We investigate experimentally and theoretically the effects of two different types of conductivity, electrical and ionic, upon magic-angle spinning NMR spectra. The experimental demonstration of these effects involves 63Cu, 65Cu, and 127I variable temperature MAS-NMR experiments on samples of γ-CuI, a Cu+-ion conductor at elevated temperatures as well as a wide bandgap semiconductor. We extend previous observations that the chemical shifts depend very strongly upon the square of the spinning-speed as well as the particular sample studied and the magnetic field strength. By using the 207Pb resonance of lead nitrate mixed with the γ-CuI as an internal chemical shift thermometer we show that frictional heating effects of the rotor do not account for the observations. Instead, we find that spinning bulk CuI, a p-type semiconductor due to Cu+ vacancies in nonstoichiometric samples, in a magnetic field generates induced AC electric currents from the Lorentz force that can resistively heat the sample by over 200 °C. These induced currents oscillate along the rotor spinning axis at the spinning speed. Their associated heating effects are disrupted in samples containing inert filler material, indicating the existence of macroscopic current pathways between micron-sized crystallites. Accurate measurements of the temperature-dependence of the 63Cu and 127I chemical shifts in such diluted samples reveal that they are of similar magnitude (ca. 0.27 ppm/K) but opposite sign (being negative for 63Cu), and appear to depend slightly upon the particular sample. This relationship is identical to the corresponding slopes of the chemical shifts versus square of the spinning speed, again consistent with sample heating as the source of the observed large shift changes. Higher drive-gas pressures are required to spin samples that have higher effective electrical conductivities, indicating the presence of a braking effect arising from the induced currents produced by rotating a

  9. Electrical and ionic conductivity effects on magic-angle spinning nuclear magnetic resonance parameters of CuI.

    PubMed

    Yesinowski, James P; Ladouceur, Harold D; Purdy, Andrew P; Miller, Joel B

    2010-12-21

    We investigate experimentally and theoretically the effects of two different types of conductivity, electrical and ionic, upon magic-angle spinning NMR spectra. The experimental demonstration of these effects involves (63)Cu, (65)Cu, and (127)I variable temperature MAS-NMR experiments on samples of γ-CuI, a Cu(+)-ion conductor at elevated temperatures as well as a wide bandgap semiconductor. We extend previous observations that the chemical shifts depend very strongly upon the square of the spinning-speed as well as the particular sample studied and the magnetic field strength. By using the (207)Pb resonance of lead nitrate mixed with the γ-CuI as an internal chemical shift thermometer we show that frictional heating effects of the rotor do not account for the observations. Instead, we find that spinning bulk CuI, a p-type semiconductor due to Cu(+) vacancies in nonstoichiometric samples, in a magnetic field generates induced AC electric currents from the Lorentz force that can resistively heat the sample by over 200 °C. These induced currents oscillate along the rotor spinning axis at the spinning speed. Their associated heating effects are disrupted in samples containing inert filler material, indicating the existence of macroscopic current pathways between micron-sized crystallites. Accurate measurements of the temperature-dependence of the (63)Cu and (127)I chemical shifts in such diluted samples reveal that they are of similar magnitude (ca. 0.27 ppm/K) but opposite sign (being negative for (63)Cu), and appear to depend slightly upon the particular sample. This relationship is identical to the corresponding slopes of the chemical shifts versus square of the spinning speed, again consistent with sample heating as the source of the observed large shift changes. Higher drive-gas pressures are required to spin samples that have higher effective electrical conductivities, indicating the presence of a braking effect arising from the induced currents produced by

  10. Recent developments in solid-state magic-angle spinning, nuclear magnetic resonance of fully and significantly isotopically labelled peptides and proteins.

    PubMed Central

    Straus, Suzana K

    2004-01-01

    In recent years, a large number of solid-state nuclear magnetic resonance (NMR) techniques have been developed and applied to the study of fully or significantly isotopically labelled ((13)C, (15)N or (13)C/(15)N) biomolecules. In the past few years, the first structures of (13)C/(15)N-labelled peptides, Gly-Ile and Met-Leu-Phe, and a protein, Src-homology 3 domain, were solved using magic-angle spinning NMR, without recourse to any structural information obtained from other methods. This progress has been made possible by the development of NMR experiments to assign solid-state spectra and experiments to extract distance and orientational information. Another key aspect to the success of solid-state NMR is the advances made in sample preparation. These improvements will be reviewed in this contribution. Future prospects for the application of solid-state NMR to interesting biological questions will also briefly be discussed. PMID:15306412

  11. {sup 129}Xe magic-angle spinning spectra of xenon in zeolite NaA direct observation of mixed clusters of co-adsorbed species.

    SciTech Connect

    Jameson, A. K.; Jameson, C. J.; de Dios, A. C.; Oldfield, E.; Gerald, R. E., II; Turner, G. L.; Chemical Engineering; Loyola Univ.; Univ. of Illinois at Chicago; Univ. of Illinois; Spectral Data Services, Inc.

    1995-01-01

    We present the first demonstration that the individual {sup 129}Xe resonances corresponding to Xe{sub n} (n = 1-8) clusters inside the {alpha}-cages of zeolite NaA can be narrowed under magic-angle spinning (MAS). Under these high-resolution conditions we also observe upon addition of Kr the individual peaks corresponding to mixed clusters, Xe{sub n}Kr{sub m}, inside the a-cages, which will allow the first direct determination of the distribution of co-adsorbates in a microporous solid. Under MAS the chemical shifts of the Xe{sub n} clusters are shown to be highly sensitive to 'disorder' in the zeolite and provides new, quantitative information about the presence of {alpha}-cages of several types.

  12. Two-Dimensional NMR Study of a Liquid-Crystal Solution under Magic-Angle Spinning. Conformation of Carboxylic Ionophore Lasalocid A Dissolved in a Lyotropic Liquid Crystal

    NASA Astrophysics Data System (ADS)

    Kimura, Atsuomi; Kano, Tetsushi; Fujiwara, Hideaki

    1996-07-01

    The conformation of a carboxylic ionophore, lasalocid A, has been determined in a lyotropic liquid crystal by means of magic-angle spinning (MAS) and two-dimensional NMR experiments. The information extracted from ROESY spectra measured under MAS was analyzed according to the distance-geometry algorithm. The liquid crystal used for the solvent is cesium perfluorooctanoate dissolved in D2O, and the resulting structure of lasalocid A is a cyclic one, indicating cation complexation within a hydrophobic region of the liquid crystal. In this way, the two-dimensional MAS NMR experiment is proved to be a useful technique in conformational studies of complex molecules dissolved in lyotropic liquid crystal which may be regarded as offering a membrane-like environment.

  13. Crocus sativus Petals: Waste or Valuable Resource? The Answer of High-Resolution and High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance.

    PubMed

    Righi, Valeria; Parenti, Francesca; Tugnoli, Vitaliano; Schenetti, Luisa; Mucci, Adele

    2015-09-30

    Intact Crocus sativus petals were studied for the first time by high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy, revealing the presence of kinsenoside (2) and goodyeroside A (3), together with 3-hydroxy-γ-butyrolactone (4). These findings were confirmed by HR-NMR analysis of the ethanol extract of fresh petals and showed that, even though carried out rapidly, partial hydrolysis of glucopyranosyloxybutanolides occurs during extraction. On the other hand, kaempferol 3-O-sophoroside (1), which is "NMR-silent" in intact petals, is present in extracts. These results suggest to evaluate the utilization of saffron petals for phytopharmaceutical and nutraceutical purposes to exploit a waste product of massive production of commercial saffron and point to the application of HR-MAS NMR for monitoring bioactive compounds directly on intact petals, avoiding the extraction procedure and the consequent hydrolysis reaction. PMID:26367873

  14. Caught in the act: ATP hydrolysis of an ABC-multidrug transporter followed by real-time magic angle spinning NMR.

    PubMed

    Hellmich, Ute A; Haase, Winfried; Velamakanni, Saroj; van Veen, Hendrik W; Glaubitz, Clemens

    2008-10-15

    The ATP binding cassette (ABC) transporter LmrA from Lactococcus lactis transports cytotoxic molecules at the expense of ATP. Molecular and kinetic details of LmrA can be assessed by solid-state nuclear magnetic resonance (ssNMR), if functional reconstitution at a high protein-lipid ratio can be achieved and the kinetic rate constants are small enough. In order to follow ATP hydrolysis directly by 31P-magic angle spinning (MAS) nuclear magnetic resonance (NMR), we generated such conditions by reconstituting LmrA-dK388, a mutant with slower ATP turnover rate, at a protein-lipid ration of 1:150. By analysing time-resolved 31P spectra, protein activity has been directly assessed. These data demonstrate the general possibility to perform ssNMR studies on a fully active full length ABC transporter and also form the foundation for further kinetic studies on LmrA by NMR. PMID:18817774

  15. An NMR thermometer for cryogenic magic-angle spinning NMR: The spin-lattice relaxation of 127I in cesium iodide

    NASA Astrophysics Data System (ADS)

    Sarkar, Riddhiman; Concistrè, Maria; Johannessen, Ole G.; Beckett, Peter; Denning, Mark; Carravetta, Marina; al-Mosawi, Maitham; Beduz, Carlo; Yang, Yifeng; Levitt, Malcolm H.

    2011-10-01

    The accurate temperature measurement of solid samples under magic-angle spinning (MAS) is difficult in the cryogenic regime. It has been demonstrated by Thurber et al. (J. Magn. Reson., 196 (2009) 84-87) [10] that the temperature dependent spin-lattice relaxation time constant of 79Br in KBr powder can be useful for measuring sample temperature under MAS over a wide temperature range (20-296 K). However the value of T1 exceeds 3 min at temperatures below 20 K, which is inconveniently long. In this communication, we show that the spin-lattice relaxation time constant of 127I in CsI powder can be used to accurately measure sample temperature under MAS within a reasonable experimental time down to 10 K.

  16. 1H High Resolution Magic-Angle Coil Spinning (HR-MACS) - NMR Metabolic Profiling of whole Saccharomyces cervisiae cells: A Demonstrative Study

    NASA Astrophysics Data System (ADS)

    Wong, Alan; Boutin, Celine; Aguiar, Pedro

    2014-06-01

    The low sensitivity of Nuclear Magnetic Resonance (NMR) is its prime shortcoming compared to other analytical methods for metabolomic studies. It relies on large sample volume (30-50 µl for HR-MAS) for rich metabolic profiling, hindering high-throughput screening especially when the sample requires a labor-intensive preparation or is a sacred specimen. This is indeed the case for some living organisms. This study evaluates a 1H HR-MAS approach for metabolic profiling of small volume (250 nl) whole bacterial cells, Saccharomyces cervisiae, using an emerging micro-NMR technology: high-resolution magic-angle coil spinning (HR-MACS). As a demonstrative study for whole cells, we perform two independent metabolomics studies identifying the significant metabolites associated with osmotic stress and aging.

  17. 1H high resolution magic-angle coil spinning (HR-MACS) μNMR metabolic profiling of whole Saccharomyces cervisiae cells: a demonstrative study

    PubMed Central

    Wong, Alan; Boutin, Céline; Aguiar, Pedro M.

    2014-01-01

    The low sensitivity and thus need for large sample volume is one of the major drawbacks of Nuclear Magnetic Resonance (NMR) spectroscopy. This is especially problematic for performing rich metabolic profiling of scarce samples such as whole cells or living organisms. This study evaluates a 1H HR-MAS approach for metabolic profiling of small volumes (250 nl) of whole cells. We have applied an emerging micro-NMR technology, high-resolution magic-angle coil spinning (HR-MACS), to study whole Saccharomyces cervisiae cells. We find that high-resolution high-sensitivity spectra can be obtained with only 19 million cells and, as a demonstration of the metabolic profiling potential, we perform two independent metabolomics studies identifying the significant metabolites associated with osmotic stress and aging. PMID:24971307

  18. (1)H high resolution magic-angle coil spinning (HR-MACS) μNMR metabolic profiling of whole Saccharomyces cervisiae cells: a demonstrative study.

    PubMed

    Wong, Alan; Boutin, Céline; Aguiar, Pedro M

    2014-01-01

    The low sensitivity and thus need for large sample volume is one of the major drawbacks of Nuclear Magnetic Resonance (NMR) spectroscopy. This is especially problematic for performing rich metabolic profiling of scarce samples such as whole cells or living organisms. This study evaluates a (1)H HR-MAS approach for metabolic profiling of small volumes (250 nl) of whole cells. We have applied an emerging micro-NMR technology, high-resolution magic-angle coil spinning (HR-MACS), to study whole Saccharomyces cervisiae cells. We find that high-resolution high-sensitivity spectra can be obtained with only 19 million cells and, as a demonstration of the metabolic profiling potential, we perform two independent metabolomics studies identifying the significant metabolites associated with osmotic stress and aging. PMID:24971307

  19. Homonuclear dipolar recoupling under ultra-fast magic-angle spinning: probing 19F-19F proximities by solid-state NMR.

    PubMed

    Wang, Qiang; Hu, Bingwen; Lafon, Olivier; Trébosc, Julien; Deng, Feng; Amoureux, Jean-Paul

    2010-03-01

    We describe dipolar recoupling methods that accomplish, at high magic-angle spinning (MAS) frequencies, the excitation of double-quantum (DQ) coherences between spin-1/2 nuclei. We employ rotor-synchronized symmetry-based pulse sequences which are either gamma-encoded or non-gamma-encoded. The sensitivity and the robustness to both chemical-shift anisotropy and offset are examined. We also compare different techniques to avoid signal folding in the indirect dimension of two-dimensional double-quantum<-->single-quantum (DQ-SQ) spectra. This comprehensive analysis results in the identification of satisfactory conditions for dipolar (19)F-(19)F recoupling at high magnetic fields and high MAS frequencies. The utility of these recoupling methods is demonstrated with high-resolution DQ-SQ NMR spectra, which allow probing (19)F-(19)F proximities in powered fluoroaluminates. PMID:20044288

  20. In situ structural characterization of a recombinant protein in native Escherichia coli membranes with solid-state magic-angle-spinning NMR.

    PubMed

    Fu, Riqiang; Wang, Xingsheng; Li, Conggang; Santiago-Miranda, Adriana N; Pielak, Gary J; Tian, Fang

    2011-08-17

    The feasibility of using solid-state magic-angle-spinning NMR spectroscopy for in situ structural characterization of the LR11 (sorLA) transmembrane domain (TM) in native Escherichia coli membranes is presented. LR11 interacts with the human amyloid precursor protein (APP), a central player in the pathology of Alzheimer's disease. The background signals from E. coli lipids and membrane proteins had only minor effects on the LR11 TM resonances. Approximately 50% of the LR11 TM residues were assigned by using (13)C PARIS data. These assignments allowed comparisons of the secondary structure of the LR11 TM in native membrane environments and commonly used membrane mimics (e.g., micelles). In situ spectroscopy bypasses several obstacles in the preparation of membrane proteins for structural analysis and offers the opportunity to investigate how membrane heterogeneity, bilayer asymmetry, chemical gradients, and macromolecular crowding affect the protein structure. PMID:21774553

  1. Conformational dynamics of phenylene rings in poly(p-phenylene vinylene) as revealed by 13C magic-angle-spinning exchange nuclear magnetic resonance experiments

    NASA Astrophysics Data System (ADS)

    deAzevedo, E. R.; Franco, R. W. A.; Marletta, A.; Faria, R. M.; Bonagamba, T. J.

    2003-08-01

    Poly(p-phenylene vinylene) (PPV) has shown a great potential for electro-optical applications due to its electroluminescent and semiconducting properties. Such properties are directly related with the polymer chain conformation and dynamics. Then, it is important to understand in detail the local chain motions. In this work, three 13C solid-state magic-angle-spinning (MAS) exchange NMR techniques were used to study conformational dynamics of phenylene rings in PPV. The standard 2D MAS exchange experiment was used to identify exchange processes between equivalent and nonequivalent sites. Centerband-only detection of exchange (CODEX) experiments were applied to determine the amplitude of the phenylene ring flips and small-angle oscillations. Additionally, a new version of the CODEX technique, which allows for the selective observation of segments executing exchange between non-equivalent sites, is demonstrated and applied to determine the flipping fractions and the activation energies of the phenylene ring rotations. It was found that, at -15 °C, (26±3)% of the rings undergo 180° flips in the millisecond time scale, with average imprecision of (30±5)° and activation energies of (23±3) kJ/mol. Other (31±10)% of the rings perform only small-angle oscillations with an average amplitude of (9±2)°. These results corroborate previous experimental data and agree with recent ab initio calculations of potential energies barriers in phenylenevinylene oligomers.

  2. Magic Physics?

    ERIC Educational Resources Information Center

    Featonby, David

    2010-01-01

    This article examines several readily available "magic tricks" which base their "trickery" on physics principles, and questions the use of the word "magic" in the 21st century, both in popular children's science and in everyday language. (Contains 18 figures.)

  3. Creating Magic Squares.

    ERIC Educational Resources Information Center

    Lyon, Betty Clayton

    1990-01-01

    One method of making magic squares using a prolongated square is illustrated. Discussed are third-order magic squares, fractional magic squares, fifth-order magic squares, decimal magic squares, and even magic squares. (CW)

  4. (11)B Solid-State NMR Interaction Tensors of Linear Two-Coordinate Boron: The Dimesitylborinium Cation.

    PubMed

    Alain, Amanda E; Shoji, Yoshiaki; Fukushima, Takanori; Bryce, David L

    2015-12-21

    Borinium cations (R2B(+)) are of particular fundamental and applied interest in part due to their pronounced Lewis acidity which enables unique chemical transformations. Solid-state NMR spectroscopy of magic-angle spinning and stationary powdered samples of the dicoordinate boron cation in the recently reported dimesitylborinium tetrakis(pentafluorophenyl)borate compound (Shoji et al. Nature Chem. 2014, 6, 498) is applied to characterize the (11)B electric field gradient (EFG) and chemical shift (CS) tensors. The experimental data are consistent with linear C-B(+)-C geometry. The (11)B quadrupolar coupling constant, 5.44 ± 0.08 MHz, and the span of the CS tensor, 130 ± 1 ppm, are both particularly large relative to literature data for a variety of boron functional groups, and represent the first such data for the linear C-B(+)-C borinium moiety. The NMR data are similar to those for the neutral tricoordinate analogue, trimesitylborane, but contrast with those of the Cp*2B(+) cation. Quantum chemical calculations are applied to provide additional insights into the relationship between the NMR observables and the molecular and electronic structure of the dimesitylborinium cation. PMID:26624205

  5. Perturbation of nuclear spin polarizations in solid state NMR of nitroxide-doped samples by magic-angle spinning without microwaves

    SciTech Connect

    Thurber, Kent R. Tycko, Robert

    2014-05-14

    We report solid state {sup 13}C and {sup 1}H nuclear magnetic resonance (NMR) experiments with magic-angle spinning (MAS) on frozen solutions containing nitroxide-based paramagnetic dopants that indicate significant perturbations of nuclear spin polarizations without microwave irradiation. At temperatures near 25 K, {sup 1}H and cross-polarized {sup 13}C NMR signals from {sup 15}N,{sup 13}C-labeled L-alanine in trinitroxide-doped glycerol/water are reduced by factors as large as six compared to signals from samples without nitroxide doping. Without MAS or at temperatures near 100 K, differences between signals with and without nitroxide doping are much smaller. We attribute most of the reduction of NMR signals under MAS near 25 K to nuclear spin depolarization through the cross-effect dynamic nuclear polarization mechanism, in which three-spin flips drive nuclear polarizations toward equilibrium with spin polarization differences between electron pairs. When T{sub 1e} is sufficiently long relative to the MAS rotation period, the distribution of electron spin polarization across the nitroxide electron paramagnetic resonance lineshape can be very different from the corresponding distribution in a static sample at thermal equilibrium, leading to the observed effects. We describe three-spin and 3000-spin calculations that qualitatively reproduce the experimental observations.

  6. A Novel High-Resolution and Sensitivity-Enhanced Three-Dimensional Solid-State NMR Experiment Under Ultrafast Magic Angle Spinning Conditions.

    PubMed

    Zhang, Rongchun; Pandey, Manoj Kumar; Nishiyama, Yusuke; Ramamoorthy, Ayyalusamy

    2015-01-01

    Although magic angle spinning (MAS) solid-state NMR is a powerful technique to obtain atomic-resolution insights into the structure and dynamics of a variety of chemical and biological solids, poor sensitivity has severely limited its applications. In this study, we demonstrate an approach that suitably combines proton-detection, ultrafast-MAS and multiple frequency dimensions to overcome this limitation. With the utilization of proton-proton dipolar recoupling and double quantum (DQ) coherence excitation/reconversion radio-frequency pulses, very high-resolution proton-based 3D NMR spectra that correlate single-quantum (SQ), DQ and SQ coherences of biological solids have been obtained successfully for the first time. The proposed technique requires a very small amount of sample and does not need multiple radio-frequency (RF) channels. It also reveals information about the proximity between a spin and a certain other dipolar-coupled pair of spins in addition to regular SQ/DQ and SQ/SQ correlations. Although (1)H spectral resolution is still limited for densely proton-coupled systems, the 3D technique is valuable to study dilute proton systems, such as zeolites, small molecules, or deuterated samples. We also believe that this new methodology will aid in the design of a plethora of multidimensional NMR techniques and enable high-throughput investigation of an exciting class of solids at atomic-level resolution. PMID:26138791

  7. Microanisotropy imaging: quantification of microscopic diffusion anisotropy and orientational order parameter by diffusion MRI with magic-angle spinning of the q-vector

    NASA Astrophysics Data System (ADS)

    Lasič, Samo; Szczepankiewicz, Filip; Eriksson, Stefanie; Nilsson, Markus; Topgaard, Daniel

    2014-02-01

    Diffusion tensor imaging (DTI) is the method of choice for non-invasive investigations of the structure of human brain white matter. The results are conventionally reported as maps of the fractional anisotropy (FA), which is a parameter related to microstructural features such as axon density, diameter, and myelination. The interpretation of FA in terms of microstructure becomes ambiguous when there is a distribution of axon orientations within the image voxel. In this paper, we propose a procedure for resolving this ambiguity by determining a new parameter, the microscopic fractional anisotropy (µFA), which corresponds to the FA without the confounding influence of orientation dispersion. In addition, we suggest a method for measuring the orientational order parameter (OP) for the anisotropic objects. The experimental protocol is capitalizing on a recently developed diffusion NMR pulse sequence based on magic-angle spinning of the q-vector. Proof-of-principle experiments are carried out on microimaging and clinical MRI equipment using lyotropic liquid crystals and plant tissues as model materials with high µFA and low FA on account of orientation dispersion. We expect the presented method to be especially fruitful in combination with DTI and high angular resolution acquisition protocols for neuroimaging studies of grey and white matter.

  8. Systematic evaluation of heteronuclear spin decoupling in solid-state NMR at the rotary-resonance conditions in the regime of fast magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Sharma, Kshama; Madhu, P. K.; Agarwal, Vipin

    2016-09-01

    The performance of heteronuclear spin decoupling sequences in solid-state NMR severely degrades when the proton radiofrequency (RF) nutation frequencies (ν1) are close to or at multiples of magic-angle spinning (MAS) frequency (νr) that are referred to as rotary-resonance recoupling conditions (ν1 = n · νr). Recently, two schemes, namely, PISSARRO and rCWApA, have been shown to be less affected by the problem of MAS and RF interference, specifically at the n = 2 rotary-resonance recoupling condition, especially in the fast MAS regime. Here, we systematically evaluate the loss in intensity of several heteronuclear spin decoupling sequences at the n = 1, 2 conditions compared to high-power decoupling in the fast-MAS regime. We propose that in the fast-MAS regime (above 40 kHz) the entire discussion about RF and MAS interference can be avoided by using appropriate low-power decoupling sequences which give comparable performance to decoupling sequences with high-power 1H irradiation of ca.195 kHz.

  9. Metabolomics by Proton High-Resolution Magic-Angle-Spinning Nuclear Magnetic Resonance of Tomato Plants Treated with Two Secondary Metabolites Isolated from Trichoderma.

    PubMed

    Mazzei, Pierluigi; Vinale, Francesco; Woo, Sheridan Lois; Pascale, Alberto; Lorito, Matteo; Piccolo, Alessandro

    2016-05-11

    Trichoderma fungi release 6-pentyl-2H-pyran-2-one (1) and harzianic acid (2) secondary metabolites to improve plant growth and health protection. We isolated metabolites 1 and 2 from Trichoderma strains, whose different concentrations were used to treat seeds of Solanum lycopersicum. The metabolic profile in the resulting 15 day old tomato leaves was studied by high-resolution magic-angle-spinning nuclear magnetic resonance (HRMAS NMR) spectroscopy directly on the whole samples without any preliminary extraction. Principal component analysis (PCA) of HRMAS NMR showed significantly enhanced acetylcholine and γ-aminobutyric acid (GABA) content accompanied by variable amount of amino acids in samples treated with both Trichoderma secondary metabolites. Seed germination rates, seedling fresh weight, and the metabolome of tomato leaves were also dependent upon doses of metabolites 1 and 2 treatments. HRMAS NMR spectroscopy was proven to represent a rapid and reliable technique for evaluating specific changes in the metabolome of plant leaves and calibrating the best concentration of bioactive compounds required to stimulate plant growth. PMID:27088924

  10. Quantification of microheterogeneity in glioblastoma multiforme with ex vivo high-resolution magic-angle spinning (HRMAS) proton magnetic resonance spectroscopy.

    PubMed Central

    Cheng, L. L.; Anthony, D. C.; Comite, A. R.; Black, P. M.; Tzika, A. A.; Gonzalez, R. G.

    2000-01-01

    Microheterogeneity is a routinely observed neuropathologic characteristic in brain tumor pathology. Although microheterogeneity is readily documented by routine histologic techniques, these techniques only measure tumor status at the time of biopsy or surgery and do not indicate likely tumor progression. A biochemical screening technique calibrated against pathologic standards would greatly assist in predicting tumor progression from its biological activity. Here we demonstrate for the first time that proton magnetic resonance spectroscopy (1H MRS) with high-resolution magic-angle spinning (HRMAS), a technique introduced in 1997, can preserve tissue histopathologic features while producing well-resolved spectra of cellular metabolites in the identical intact tissue specimens. Observed biochemical alterations and tumor histopathologic characteristics can thus be correlated for the same surgical specimen, obviating the problems caused by tumor microheterogeneity. We analyzed multiple specimens of a single human glioblastoma multiforme surgically removed from a 44-year-old patient. Each specimen was first measured with HRMAS 1H MRS to determine tumor metabolites, then evaluated by quantitative histopathology. The concentrations of lactate and mobile lipids measured with HRMAS linearly reflected the percentage of tumor necrosis. Moreover, metabolic ratios of phosphorylcholine to choline correlated linearly with the percentage of the highly cellular malignant glioma. The quantification of tumor metabolic changes with HRMAS 1H MRS, in conjunction with subsequent histopathology of the same tumor specimen, has the potential to further our knowledge of the biochemistry of tumor heterogeneity during development, and thus ultimately to improve our accuracy in diagnosing, characterizing, and evaluating tumor progression. PMID:11303625

  11. Atomic-resolution structure of the CAP-Gly domain of dynactin on polymeric microtubules determined by magic angle spinning NMR spectroscopy.

    PubMed

    Yan, Si; Guo, Changmiao; Hou, Guangjin; Zhang, Huilan; Lu, Xingyu; Williams, John Charles; Polenova, Tatyana

    2015-11-24

    Microtubules and their associated proteins perform a broad array of essential physiological functions, including mitosis, polarization and differentiation, cell migration, and vesicle and organelle transport. As such, they have been extensively studied at multiple levels of resolution (e.g., from structural biology to cell biology). Despite these efforts, there remain significant gaps in our knowledge concerning how microtubule-binding proteins bind to microtubules, how dynamics connect different conformational states, and how these interactions and dynamics affect cellular processes. Structures of microtubule-associated proteins assembled on polymeric microtubules are not known at atomic resolution. Here, we report a structure of the cytoskeleton-associated protein glycine-rich (CAP-Gly) domain of dynactin motor on polymeric microtubules, solved by magic angle spinning NMR spectroscopy. We present the intermolecular interface of CAP-Gly with microtubules, derived by recording direct dipolar contacts between CAP-Gly and tubulin using double rotational echo double resonance (dREDOR)-filtered experiments. Our results indicate that the structure adopted by CAP-Gly varies, particularly around its loop regions, permitting its interaction with multiple binding partners and with the microtubules. To our knowledge, this study reports the first atomic-resolution structure of a microtubule-associated protein on polymeric microtubules. Our approach lays the foundation for atomic-resolution structural analysis of other microtubule-associated motors. PMID:26604305

  12. Proton-detected solid-state NMR spectroscopy of fully protonated proteins at slow to moderate magic-angle spinning frequencies

    NASA Astrophysics Data System (ADS)

    Mote, Kaustubh R.; Madhu, Perunthiruthy K.

    2015-12-01

    1H -detection offers a substitute to the sensitivity-starved experiments often used to characterize biomolecular samples using magic-angle spinning solid-state NMR spectroscopy (MAS-ssNMR). To mitigate the effects of the strong 1H -1H dipolar coupled network that would otherwise severely broaden resonances, high MAS frequencies (>40 kHz) are often employed. Here, we have explored the alternative of stroboscopic 1H -detection at moderate MAS frequencies of 5-30 kHz using windowed version of supercycled-phase-modulated Lee-Goldburg homonuclear decoupling. We show that improved resolution in the 1H dimension, comparable to that obtainable at high spinning frequencies of 40-60 kHz without homonuclear decoupling, can be obtained in these experiments for fully protonated proteins. Along with detailed analysis of the performance of the method on the standard tri-peptide f-MLF, experiments on micro-crystalline GB1 and amyloid- β aggregates are used to demonstrate the applicability of these pulse-sequences to challenging biomolecular systems. With only two parameters to optimize, broadbanded performance of the homonuclear decoupling sequence, linear dependence of the chemical-shift scaling factor on resonance offset and a straightforward implementation under experimental conditions currently used for many biomolecular studies (viz. spinning frequencies and radio-frequency amplitudes), we expect these experiments to complement the current 13C -detection based methods in assignments and characterization through chemical-shift mapping.

  13. Multidimensional High-Resolution Magic Angle Spinning and Solution-State NMR Characterization of (13)C-labeled Plant Metabolites and Lignocellulose.

    PubMed

    Mori, Tetsuya; Tsuboi, Yuuri; Ishida, Nobuhiro; Nishikubo, Nobuyuki; Demura, Taku; Kikuchi, Jun

    2015-01-01

    Lignocellulose, which includes mainly cellulose, hemicellulose, and lignin, is a potential resource for the production of chemicals and for other applications. For effective production of materials derived from biomass, it is important to characterize the metabolites and polymeric components of the biomass. Nuclear magnetic resonance (NMR) spectroscopy has been used to identify biomass components; however, the NMR spectra of metabolites and lignocellulose components are ambiguously assigned in many cases due to overlapping chemical shift peaks. Using our (13)C-labeling technique in higher plants such as poplar samples, we demonstrated that overlapping peaks could be resolved by three-dimensional NMR experiments to more accurately assign chemical shifts compared with two-dimensional NMR measurements. Metabolites of the (13)C-poplar were measured by high-resolution magic angle spinning NMR spectroscopy, which allows sample analysis without solvent extraction, while lignocellulose components of the (13)C-poplar dissolved in dimethylsulfoxide/pyridine solvent were analyzed by solution-state NMR techniques. Using these methods, we were able to unambiguously assign chemical shifts of small and macromolecular components in (13)C-poplar samples. Furthermore, using samples of less than 5 mg, we could differentiate between two kinds of genes that were overexpressed in poplar samples, which produced clearly modified plant cell wall components. PMID:26143886

  14. Multidimensional High-Resolution Magic Angle Spinning and Solution-State NMR Characterization of 13C-labeled Plant Metabolites and Lignocellulose

    PubMed Central

    Mori, Tetsuya; Tsuboi, Yuuri; Ishida, Nobuhiro; Nishikubo, Nobuyuki; Demura, Taku; Kikuchi, Jun

    2015-01-01

    Lignocellulose, which includes mainly cellulose, hemicellulose, and lignin, is a potential resource for the production of chemicals and for other applications. For effective production of materials derived from biomass, it is important to characterize the metabolites and polymeric components of the biomass. Nuclear magnetic resonance (NMR) spectroscopy has been used to identify biomass components; however, the NMR spectra of metabolites and lignocellulose components are ambiguously assigned in many cases due to overlapping chemical shift peaks. Using our 13C-labeling technique in higher plants such as poplar samples, we demonstrated that overlapping peaks could be resolved by three-dimensional NMR experiments to more accurately assign chemical shifts compared with two-dimensional NMR measurements. Metabolites of the 13C-poplar were measured by high-resolution magic angle spinning NMR spectroscopy, which allows sample analysis without solvent extraction, while lignocellulose components of the 13C-poplar dissolved in dimethylsulfoxide/pyridine solvent were analyzed by solution-state NMR techniques. Using these methods, we were able to unambiguously assign chemical shifts of small and macromolecular components in 13C-poplar samples. Furthermore, using samples of less than 5 mg, we could differentiate between two kinds of genes that were overexpressed in poplar samples, which produced clearly modified plant cell wall components. PMID:26143886

  15. Recoupling of native homonuclear dipolar couplings in magic-angle-spinning solid-state NMR by the double-oscillating field technique

    NASA Astrophysics Data System (ADS)

    Straasø, Lasse Arnt; Nielsen, Niels Chr.

    2010-08-01

    A new solid-state NMR method, the double-oscillating field technique (DUO), that under magic-angle-spinning conditions produces an effective Hamiltonian proportional to the native high-field homonuclear dipole-dipole coupling operator is presented. The method exploits one part of the radio frequency (rf) field to recouple the dipolar coupling interaction with a relatively high scaling factor and to eliminate offset effects over a reasonable bandwidth while in the recoupling frame, the other part gives rise to a sufficiently large longitudinal component of the residual rf field that averages nonsecular terms and in addition ensures stability toward rf inhomogeneity and rf miscalibration. The capability of the DUO experiment to mediate transfer of polarization is described theoretically and compared numerically and experimentally with finite pulse rf driven recoupling and experimentally with dipolar-assisted rotational resonance. Two-dimensional recoupling experiments were performed on antiparallel amyloid fibrils of the decapeptide SNNFGAILSS with the FGAIL fragment uniformly labeled with C13 and N15.

  16. Trifluoroethanol and 19F magic angle spinning nuclear magnetic resonance as a basic surface hydroxyl reactivity probe for zirconium(IV) hydroxide structures.

    PubMed

    DeCoste, Jared B; Glover, T Grant; Mogilevsky, Gregory; Peterson, Gregory W; Wagner, George W

    2011-08-01

    A novel technique for determining the relative accessibility and reactivity of basic surface hydroxyl sites by reacting various zirconium(IV) hydroxide materials with 2,2,2-trifluoroethanol (TFE) and characterizing the resulting material using (19)F magic angle spinning (MAS) nuclear magnetic resonance (NMR) is presented here. Studied here are three zirconium hydroxide samples, two unperturbed commercial materials, and one commercial material that is crushed by a pellet press. Factors, such as the ratio of bridging/terminal hydroxyls, surface area, and pore size distribution, are examined and found to affect the ability of the zirconium(IV) hydroxide to react with TFE. X-ray diffraction, nitrogen isotherms, and (1)H MAS NMR were used to characterize the unperturbed materials, while thermogravitric analysis with gas chromatography and mass spectrometry along with the (19)F MAS NMR were used to characterize the materials that were reacted with TFE. Zirconium hydroxide materials with a high surface area and a low bridging/terminal hydroxyl ratio were found to react TFE in the greatest amounts. PMID:21699226

  17. Magic Angle Spinning NMR Reveals Sequence-Dependent Structural Plasticity, Dynamics, and the Spacer Peptide 1 Conformation in HIV-1 Capsid Protein Assemblies

    SciTech Connect

    Han, Yun; Hou, Guangjin; Suiter, Christopher L.; Ahn, Jinwoo; Byeon, In-Ja L.; Lipton, Andrew S.; Burton, Sarah D.; Hung, Ivan; Gorkov, Peter L.; Gan, Zhehong; Brey, William W.; Rice, David M.; Gronenborn, Angela M.; Polenova, Tatyana E.

    2013-11-27

    Maturation of HIV-1 virus into an infectious virion requires cleavage of the Gag polyprotein into its constituent domains and formation of a conical capsid core that encloses viral RNA and a small complement of proteins for replication. The final step of this process is the cleavage of the SP1 peptide from the CA-SP1 maturation intermediate, which triggers the condensation of the CA protein into a conical capsid. The mechanism of this step, including the conformation of the SP1 peptide in CA-SP1, is under intense debate. In this report, we examine the tubular assemblies of CA and the CA-SP1 maturation intermediate using Magic Angle Spinning NMR spectroscopy. At the magnetic fields of 19.9 T and above, tubular CA and CA-SP1 assemblies yield outstanding-quality 2D and 3D MAS NMR spectra, which are amenable to resonance assignments and detailed structural characterization. Dipolar- and scalar-based correlation experiments unequivocally indicate that SP1 peptide is in a random coil conformation and mobile in the assembled CA-SP1. Analysis of two sequence variants reveals that remarkably, the conformation of SP1 tail, of the functionally important CypA loop, and of the loop preceding helix 8 are sequence dependent and modulated by the residue variations at distal sites. These findings challenge the role of SP1 as a conformational switch in the maturation process and establish sequence-dependent conformational plasticity in CA.

  18. Systematic evaluation of heteronuclear spin decoupling in solid-state NMR at the rotary-resonance conditions in the regime of fast magic-angle spinning.

    PubMed

    Sharma, Kshama; Madhu, P K; Agarwal, Vipin

    2016-09-01

    The performance of heteronuclear spin decoupling sequences in solid-state NMR severely degrades when the proton radiofrequency (RF) nutation frequencies (ν1) are close to or at multiples of magic-angle spinning (MAS) frequency (νr) that are referred to as rotary-resonance recoupling conditions (ν1=n·νr). Recently, two schemes, namely, PISSARRO and rCW(ApA), have been shown to be less affected by the problem of MAS and RF interference, specifically at the n=2 rotary-resonance recoupling condition, especially in the fast MAS regime. Here, we systematically evaluate the loss in intensity of several heteronuclear spin decoupling sequences at the n=1, 2 conditions compared to high-power decoupling in the fast-MAS regime. We propose that in the fast-MAS regime (above 40kHz) the entire discussion about RF and MAS interference can be avoided by using appropriate low-power decoupling sequences which give comparable performance to decoupling sequences with high-power (1)H irradiation of ca.195kHz. PMID:27472380

  19. Cross-Correlated Relaxation of Dipolar Coupling and Chemical-Shift Anisotropy in Magic-Angle Spinning R1ρ NMR Measurements: Application to Protein Backbone Dynamics Measurements.

    PubMed

    Kurauskas, Vilius; Weber, Emmanuelle; Hessel, Audrey; Ayala, Isabel; Marion, Dominique; Schanda, Paul

    2016-09-01

    Transverse relaxation rate measurements in magic-angle spinning solid-state nuclear magnetic resonance provide information about molecular motions occurring on nanosecond-to-millisecond (ns-ms) time scales. The measurement of heteronuclear ((13)C, (15)N) relaxation rate constants in the presence of a spin-lock radiofrequency field (R1ρ relaxation) provides access to such motions, and an increasing number of studies involving R1ρ relaxation in proteins have been reported. However, two factors that influence the observed relaxation rate constants have so far been neglected, namely, (1) the role of CSA/dipolar cross-correlated relaxation (CCR) and (2) the impact of fast proton spin flips (i.e., proton spin diffusion and relaxation). We show that CSA/D CCR in R1ρ experiments is measurable and that the CCR rate constant depends on ns-ms motions; it can thus provide insight into dynamics. We find that proton spin diffusion attenuates this CCR due to its decoupling effect on the doublet components. For measurements of dynamics, the use of R1ρ rate constants has practical advantages over the use of CCR rates, and this article reveals factors that have so far been disregarded and which are important for accurate measurements and interpretation. PMID:27500976

  20. A nuclear magnetic resonance spectrometer concept for hermetically sealed magic angle spinning investigations on highly toxic, radiotoxic, or air sensitive materials

    NASA Astrophysics Data System (ADS)

    Martel, L.; Somers, J.; Berkmann, C.; Koepp, F.; Rothermel, A.; Pauvert, O.; Selfslag, C.; Farnan, I.

    2013-05-01

    A concept to integrate a commercial high-resolution, magic angle spinning nuclear magnetic resonance (MAS-NMR) probe capable of very rapid rotation rates (70 kHz) in a hermetically sealed enclosure for the study of highly radiotoxic materials has been developed and successfully demonstrated. The concept centres on a conventional wide bore (89 mm) solid-state NMR magnet operating with industry standard 54 mm diameter probes designed for narrow bore magnets. Rotor insertion and probe tuning take place within a hermetically enclosed glovebox, which extends into the bore of the magnet, in the space between the probe and the magnet shim system. Oxygen-17 MAS-NMR measurements demonstrate the possibility of obtaining high quality spectra from small sample masses (˜10 mg) of highly radiotoxic material and the need for high spinning speeds to improve the spectral resolution when working with actinides. The large paramagnetic susceptibility arising from actinide paramagnetism in (Th1-xUx)O2 solid solutions gives rise to extensive spinning sidebands and poor resolution at 15 kHz, which is dramatically improved at 55 kHz. The first 17O MAS-NMR measurements on NpO2+x samples spinning at 55 kHz are also reported. The glovebox approach developed here for radiotoxic materials can be easily adapted to work with other hazardous or even air sensitive materials.

  1. Cross-polarization magic-angle spinning nuclear magnetic resonance study of platinum complexes containing the cis-P2PtC2 fragment.

    PubMed

    Challoner, R; Sebald, A

    1995-01-01

    31P and 195Pt cross-polarization magic-angle spinning nuclear magnetic resonance (CP-MAS NMR) spectra of three platinum complexes of formal oxidation state Pt(0) and Pt(II), respectively, are reported. All three complexes, (Ph3P)2Pt(C2H4) (1), (Et2P-CH2-CH2-PEt2)Pt(C identical to C-H)2 (2) and (Ph2P-CH2-CH2-PPh2)Pt(C identical to C-C(CH3)=CH2)2 (3) contain the square-planar cis-P2PtC2 fragment and show unusual NMR spectroscopic properties insofar that the 195Pt shielding patterns are fairly narrow in relation to what one would generally have to expect for 195Pt in square-planar coordination. Another unexpected NMR property of the cis-P2PtC2 fragment in 1-3 is the absence of spinning frequency-dependent second-order effects in this solid-state ABX spin system. PMID:7894980

  2. Recoupling of chemical shift anisotropies in solid-state NMR under high-speed magic-angle spinning and in uniformly 13C-labeled systems

    NASA Astrophysics Data System (ADS)

    Chan, Jerry C. C.; Tycko, Robert

    2003-05-01

    We demonstrate the possibility of recoupling chemical shift anisotropy (CSA) interactions in solid-state nuclear magnetic resonance (NMR) under high-speed magic-angle spinning (MAS) while retaining a static CSA powder pattern line shape and simultaneously attenuating homonuclear dipole-dipole interactions. CSA recoupling is accomplished by a rotation-synchronized radio-frequency pulse sequence with symmetry properties that permit static CSA line shapes to be obtained. We suggest a specific recoupling sequence, which we call ROCSA, for which the scaling factors for CSA and homonuclear dipole-dipole interactions are 0.272 and approximately 0.05, respectively. This sequence is suitable for high-speed 13C MAS NMR experiments on uniformly 13C-labeled organic compounds, including biopolymers. We demonstrate the ROCSA sequence experimentally by measuring the 13C CSA patterns of the uniformly labeled, polycrystalline compounds L-alanine and N-acetyl-D,L-valine at MAS frequencies of 11 and 20 kHz. We also present experimental data for amyloid fibrils formed by a 15-residue fragment of the β-amyloid peptide associated with Alzheimer's disease, in which four amino acid residues are uniformly labeled, demonstrating the applicability to biochemical systems of high molecular weight and significant complexity. Analysis of the CSA patterns in the amyloid fibril sample demonstrates the utility of ROCSA measurements as probes of peptide and protein conformation in noncrystalline solids.

  3. High-resolution 1H NMR in solids with multiple-pulse sequences and magic-angle sample spinning at 270 MHz

    NASA Astrophysics Data System (ADS)

    Scheler, G.; Haubenreisser, U.; Rosenberger, H.

    A probe suitable for 270-MHz 1H NMR in solids is described, using the combination of the phase-error-compensated WAHUHA multiple-pulse cycle and magic-angle sample spinning (MAS). The experimental results obtained at this frequency are compared with measurements at 60 MHz. Because of the increase of frequency the spectral resolution is improved by a factor of about 5. For a variety of organic and inorganic substances the resolution varies from 0.3 ppm in polycrystalline adamantane to about 2 ppm, sufficient to resolve resonance signals of protons of different molecular groups, such as NH 3, NH 4, olefinic, aromatic, and aliphatic protons. Averaged chemical shifts of a series of selected hydrogen-bonded powder samples are discussed. The residual linewidths were found to be due predominantly to second-order residual dipolar broadening, the cross term between resonance offset and dipolar interaction, nonresolved chemical shifts, and interactions of protons with nuclei which have a strong quadrupolar moment. The resolution is expected to be increased by combining the high-field MAS experiments and more effective multiple-pulse sequences, e.g., the 24-pulse cycle developed recently by Burum and Rhim.

  4. High-Speed Magic-Angle Spinning 13C MAS NMR Spectra of Adamantane: Self-Decoupling of the Heteronuclear Scalar Interaction and Proton Spin Diffusion

    NASA Astrophysics Data System (ADS)

    Ernst, Matthias; Verhoeven, Aswin; Meier, Beat H.

    1998-02-01

    We have investigated the carbon line shape of solid adamantane under high-speed magic-angle sample spinning (MAS) acquired without proton decoupling. The CH-group shows a spinning-speed-dependent line broadening while the CH2-group consists of a spinning-speed-independent sharp component and a spinning-speed-dependent broader part. These phenomena can be explained by self-decoupling of theJ-interaction due to proton spin diffusion. Such a self-decoupling process can be described by a magnetization exchange process between the multiplet lines. Changing the spin-diffusion rate constant by off-resonance irradiation of the protons allows us to observe the full range from slow exchange to coalescence to fast exchange of the carbon spectra. One of the multiplet components in the CH2-group corresponds to a group spin of the protons of zero and therefore does not couple to the other protons. This gives rise to the sharp central line. The magnetization exchange rate constant between the different multiplet lines can be determined from the spectra and is a measure for the spinning-speed-dependent proton spin-diffusion rate constant. Even at an MAS speed of 30 kHz, proton spin diffusion is still observable despite the relatively weak intermolecular proton dipolar-coupling network in adamantane which results in a static proton line width of only 14 kHz (full width at half height).

  5. Magic angle Lee-Goldburg frequency offset irradiation improves the efficiency and selectivity of SPECIFIC-CP in triple-resonance MAS solid-state NMR

    PubMed Central

    Wu, C.H.; De Angelis, Anna A.; Opella, Stanley J.

    2014-01-01

    The efficiency and selectivity of SPECIFIC-CP, a widely used method for selective double cross-polarization in triple-resonance magic angle spinning solid-state NMR, is improved by performing the tangential-shaped 13C irradiation at an offset frequency that meets the Lee-Goldburg condition (LG-SPECIFIC-CP). This is demonstrated on polycrystalline samples of uniformly 13C, 15N labeled N-acetyl-leucine and N-formyl-Met-Leu-Phe-OH (MLF) at 700 MHz and 900 MHz 1H resonance frequencies, respectively. For the single 13Cα of N-acetyl-leucine, relative to conventional broad band cross-polarization, the SPECIFIC-CP signal has 47% of the intensity. Notably, the LG-SPECIFIC-CP signal has 72% of the intensity, essentially the theoretical maximum. There were no other changes in the experimental parameters. The three 13Cα signals in MLF show some variation in intensities, reflecting the relatively narrow bandwidth of a frequency-offset procedure, and pointing to future developments for this class of experiment. PMID:25051542

  6. A Monte Carlo/Simulated Annealing Algorithm for Sequential Resonance Assignment in Solid State NMR of Uniformly Labeled Proteins with Magic-Angle Spinning

    PubMed Central

    Tycko, Robert; Hu, Kan-Nian

    2010-01-01

    We describe a computational approach to sequential resonance assignment in solid state NMR studies of uniformly 15N,13C-labeled proteins with magic-angle spinning. As input, the algorithm uses only the protein sequence and lists of 15N/13Cα crosspeaks from 2D NCACX and NCOCX spectra that include possible residue-type assignments of each crosspeak. Assignment of crosspeaks to specific residues is carried out by a Monte Carlo/simulated annealing algorithm, implemented in the program MC_ASSIGN1. The algorithm tolerates substantial ambiguity in residue-type assignments and coexistence of visible and invisible segments in the protein sequence. We use MC_ASSIGN1 and our own 2D spectra to replicate and extend the sequential assignments for uniformly labeled HET-s(218-289) fibrils previously determined manually by Siemer et al. (J. Biomolec. NMR, vol. 34, pp. 75-87, 2006) from a more extensive set of 2D and 3D spectra. Accurate assignments by MC_ASSIGN1 do not require data that are of exceptionally high quality. Use of MC_ASSIGN1 (and its extensions to other types of 2D and 3D data) is likely to alleviate many of the difficulties and uncertainties associated with manual resonance assignments in solid state NMR studies of uniformly labeled proteins, where spectral resolution and signal-to-noise are often sub-optimal. PMID:20547467

  7. Structure of (NH4)3GaF6 investigated by multinuclear magic-angle spinning NMR spectroscopy in comparison with rietveld refinement.

    PubMed

    Krahl, Thoralf; Ahrens, Mike; Scholz, Gudrun; Heidemann, Detlef; Kemnitz, Erhard

    2008-01-21

    The structure of ammonium gallium cryolite (NH(4))(3)GaF(6) was investigated by (19)F and (69,71)Ga magic-angle spinning (MAS) NMR in comparison with X-ray powder diffraction followed by Rietveld refinement. In agreement with previous thermodynamic measurements, NMR experiments on (NH(4))(3)GaF(6) support the model of rigid GaF(6) octahedra. At high spinning speeds (30 kHz), the scalar coupling between the six equivalent (19)F nuclei and (69,71)Ga can be directly observed in the powder spectra. The coupling constants are J(19)F(69)Ga = 197 Hz and J(19)F(71)Ga = 264 Hz. To explain the (71)Ga spectra recorded at 3 kHz a small distribution of quadrupolar frequencies has to be included. The spread of the spinning sidebands hints to a largest nu(Q) value of 28 kHz for (71)Ga. This can be explained by the occurrence of highly symmetric GaF(6) octahedra, which are tilted against the surrounding atoms. In addition, the incomplete motional excitation does not average out the quadrupolar effects. NMR findings are in discrepancy to those of Rietveld refinement. As result it appears that X-ray diffraction is not sensitive enough to deliver proper results. PMID:18069821

  8. Theory for cross effect dynamic nuclear polarization under magic-angle spinning in solid state nuclear magnetic resonance: The importance of level crossings

    PubMed Central

    Thurber, Kent R.; Tycko, Robert

    2012-01-01

    We present theoretical calculations of dynamic nuclear polarization (DNP) due to the cross effect in nuclear magnetic resonance under magic-angle spinning (MAS). Using a three-spin model (two electrons and one nucleus), cross effect DNP with MAS for electron spins with a large g-anisotropy can be seen as a series of spin transitions at avoided crossings of the energy levels, with varying degrees of adiabaticity. If the electron spin-lattice relaxation time T1e is large relative to the MAS rotation period, the cross effect can happen as two separate events: (i) partial saturation of one electron spin by the applied microwaves as one electron spin resonance (ESR) frequency crosses the microwave frequency and (ii) flip of all three spins, when the difference of the two ESR frequencies crosses the nuclear frequency, which transfers polarization to the nuclear spin if the two electron spins have different polarizations. In addition, adiabatic level crossings at which the two ESR frequencies become equal serve to maintain non-uniform saturation across the ESR line. We present analytical results based on the Landau-Zener theory of adiabatic transitions, as well as numerical quantum mechanical calculations for the evolution of the time-dependent three-spin system. These calculations provide insight into the dependence of cross effect DNP on various experimental parameters, including MAS frequency, microwave field strength, spin relaxation rates, hyperfine and electron-electron dipole coupling strengths, and the nature of the biradical dopants. PMID:22938251

  9. Perturbation of nuclear spin polarizations in solid state NMR of nitroxide-doped samples by magic-angle spinning without microwaves

    PubMed Central

    Thurber, Kent R.; Tycko, Robert

    2014-01-01

    We report solid state 13C and 1H nuclear magnetic resonance (NMR) experiments with magic-angle spinning (MAS) on frozen solutions containing nitroxide-based paramagnetic dopants that indicate significant perturbations of nuclear spin polarizations without microwave irradiation. At temperatures near 25 K, 1H and cross-polarized 13C NMR signals from 15N,13C-labeled L-alanine in trinitroxide-doped glycerol/water are reduced by factors as large as six compared to signals from samples without nitroxide doping. Without MAS or at temperatures near 100 K, differences between signals with and without nitroxide doping are much smaller. We attribute most of the reduction of NMR signals under MAS near 25 K to nuclear spin depolarization through the cross-effect dynamic nuclear polarization mechanism, in which three-spin flips drive nuclear polarizations toward equilibrium with spin polarization differences between electron pairs. When T1e is sufficiently long relative to the MAS rotation period, the distribution of electron spin polarization across the nitroxide electron paramagnetic resonance lineshape can be very different from the corresponding distribution in a static sample at thermal equilibrium, leading to the observed effects. We describe three-spin and 3000-spin calculations that qualitatively reproduce the experimental observations. PMID:24832263

  10. Theory for cross effect dynamic nuclear polarization under magic-angle spinning in solid state nuclear magnetic resonance: the importance of level crossings.

    PubMed

    Thurber, Kent R; Tycko, Robert

    2012-08-28

    We present theoretical calculations of dynamic nuclear polarization (DNP) due to the cross effect in nuclear magnetic resonance under magic-angle spinning (MAS). Using a three-spin model (two electrons and one nucleus), cross effect DNP with MAS for electron spins with a large g-anisotropy can be seen as a series of spin transitions at avoided crossings of the energy levels, with varying degrees of adiabaticity. If the electron spin-lattice relaxation time T(1e) is large relative to the MAS rotation period, the cross effect can happen as two separate events: (i) partial saturation of one electron spin by the applied microwaves as one electron spin resonance (ESR) frequency crosses the microwave frequency and (ii) flip of all three spins, when the difference of the two ESR frequencies crosses the nuclear frequency, which transfers polarization to the nuclear spin if the two electron spins have different polarizations. In addition, adiabatic level crossings at which the two ESR frequencies become equal serve to maintain non-uniform saturation across the ESR line. We present analytical results based on the Landau-Zener theory of adiabatic transitions, as well as numerical quantum mechanical calculations for the evolution of the time-dependent three-spin system. These calculations provide insight into the dependence of cross effect DNP on various experimental parameters, including MAS frequency, microwave field strength, spin relaxation rates, hyperfine and electron-electron dipole coupling strengths, and the nature of the biradical dopants. PMID:22938251

  11. The molecular origin of a loading-induced black layer in the deep region of articular cartilage at the magic angle

    PubMed Central

    Wang, Nian; Kahn, David; Badar, Farid; Xia, Yang

    2014-01-01

    Purpose To investigate the molecular origin of an unusual low-intensity layer in the deep region of articular cartilage as seen in MRI when the tissue is imaged under compression and oriented at the magic angle. Materials and Methods Microscopic MRI (μMRI) T2 and T1ρ experiments were carried out for both native and degraded (treated with trypsin) 18 specimens. The glycosaminoglycan (GAG) concentrations in the specimens were quantified by both sodium ICP-OES and μMRI Gd(DTPA)2--contrast methods. The mechanical modulus of the specimens was also measured. Results Native tissue shows no load-induced layer, while the trypsin-degraded tissue shows clearly the low-intensity line at the deep part of tissue. The GAG reductions are confirmed by the sodium ICP-OES (from 81.7 ± 5.4 mg/ml to 9.2 ± 3.4 mg/ml), MRI GAG quantification (from 72.4 ± 6.7 mg/ml to 11.2 ± 2.9 mg/ml). The modulus reduction is confirmed by biomechanics (from 4.3 ± 0.7 MPa to 0.3 ± 0.1 MPa). Conclusion Both T2 and T1ρ profiles in native and degraded cartilage show strongly strain-, depth-, and angle-dependent using high resolution MRI. The GAG reduction is responsible for the visualization of a low-intensity layer in deep cartilage when it is loaded and orientated at 55°. PMID:24833266

  12. Menu Magic!

    ERIC Educational Resources Information Center

    Smith, Susan H.; Hickey, Bethany

    2003-01-01

    Describes the activity "Menu Magic!" that helps eighth graders review the power of adjectives. Notes that students "eat up this project" that promises to deliver the opportunity to analyze, synthesize, and evaluate while giving students the chance to work in cooperative groups. Describes and gives examples of the "Menu Magic" project. (SG)

  13. A High-Resolution 3D Separated-Local-Field Experiment by Means of Magic-Angle Turning

    PubMed

    Hu; Alderman; Pugmire; Grant

    1997-05-01

    A 3D separated-local-field (SLF) experiment based on the 2D PHORMAT technique is described. In the 3D experiment, the conventional 2D SLF powder pattern for each chemically inequivalent carbon is separated according to their different isotropic chemical shifts. The dipolar coupling constant of a C-H pair, hence the bond distance, and the relative orientation of the chemical-shift tensor to the C-H vector can all be determined for the protonated carbons with a single measurement. As the sample turns at only about 30 Hz in a MAT experiment, the SLF patterns obtained approach those of a stationary sample, and an accuracy in the measurement similar to that obtained on a stationary sample is expected. The technique is demonstrated on 2,6-dimethoxynaphthalene, where the 13 C-1 H separated-local-field powder patterns for the six chemically inequivalent carbons are clearly identified and measured. The observed dipolar coupling for the methoxy carbon is effectively reduced by the fast rotation of the group about its C3 symmetry axis. The average angle between the C-H bond direction and the C3 rotation axis in the OCH3 group is found to be about 66°. PMID:9252281

  14. Breakup of 87 MeV [sup 11]B

    SciTech Connect

    Wolfs, F.L.H.; White, C.A.; Bryan, D.C.; Freeman, C.G.; Herrick, D.M.; Kurz, K.L.; Mathews, D.H.; Perera, P.A.A.; Zanni, M.T. )

    1994-05-01

    A segmented focal plane detector has been used to study the breakup of 87 MeV [sup 11]B ions incident on a [sup 12]C target into [sup 4]He and [sup 7]Li fragments at relative energies between 0 and 4 MeV. The relative energy spectra are dominated by sequential breakup of the 9.28 MeV, 10.26+10.33 MeV, and 10.60 MeV excited states in [sup 11]B. The measured breakup yields decrease with increasing center-of-mass scattering angle, consistent with predictions made using single-step inelastic distorted wave Born approximation calculations. Applications of this technique to study the breakup of [sup 16]O at low relative energies will be discussed.

  15. Characterization of high-tannin fractions from humus by carbon-13 cross-polarization and magic-angle spinning nuclear magnetic resonance.

    PubMed

    Lorenz, Klaus; Preston, Caroline M

    2002-01-01

    Condensed tannins can be found in various parts of many plants. Unlike lignin there has been little study of their fate as they enter the soil organic matter pool and their influence on nutrient cycling, especially through their protein-binding properties. We extracted and characterized tannin-rich fractions from humus collected in 1998 from a black spruce [Picea mariana (Mill.) Britton et al.] forest in Canada where a previous study (1995) showed high levels (3.8% by weight) of condensed tannins. A reference tannin purified from black spruce needles was characterized by solution 13C nuclear magnetic resonance (NMR) as a pure procyanidin with mainly cis stereochemistry and an average chain length of four to five units. The colorimetric proanthocyanidin (PA) assay, standardized against the black spruce tannin, showed that both extracted humus fractions had higher tannin contents than the original humus (2.84% and 11.17% vs. 0.08%), and accounted for 32% of humus tannin content. Consistent with the results from the chemical assay, the aqueous fraction showed higher tannin signals in the 13C cross-polarization and magic-angle spinning (CPMAS) NMR spectrum than the emulsified one. As both tannin-rich humus fractions were depleted in N and high in structures derived from lignin and cutin, they did not have properties consistent with recaldtrant tannin-protein complexes proposed as a mechanism for N sequestration in humus. Further studies are needed to establish if tannin-protein structures in humus can be detected or isolated, or if tannins contribute to forest management problems observed in these ecosystems by binding to and slowing down the activity of soil enzymes. PMID:11931430

  16. Magic Angle Spinning Nuclear Magnetic Resonance Characterization of Voltage-Dependent Anion Channel Gating in Two-Dimensional Lipid Crystalline Bilayers

    PubMed Central

    2015-01-01

    The N-terminus of the voltage-dependent anion channel (VDAC) has been proposed to contain the mechanistically important gating helices that modulate channel opening and closing. In this study, we utilize magic angle spinning nuclear magnetic resonance (MAS NMR) to determine the location and structure of the N-terminus for functional channels in lipid bilayers by measuring long-range 13C–13C distances between residues in the N-terminus and other domains of VDAC reconstituted into DMPC lipid bilayers. Our structural studies show that the distance between A14 Cβ in the N-terminal helix and S193 Cβ is ∼4–6 Å. Furthermore, VDAC phosphorylation by a mitochondrial kinase at residue S193 has been claimed to delay mitochondrial cell death by causing a conformational change that closes the channel, and a VDAC-Ser193Glu mutant has been reported to show properties very similar to those of phosphorylated VDAC in a cellular context. We expressed VDAC-S193E and reconstituted it into DMPC lipid bilayers. Two-dimensional 13C–13C correlation experiments showed chemical shift perturbations for residues located in the N-terminus, indicating possible structural perturbations to that region. However, electrophysiological data recorded on VDAC-S193E showed that channel characteristics were identical to those of wild type samples, indicating that phosphorylation of S193 does not directly affect channel gating. The combination of NMR and electrophysiological results allows us to discuss the validity of proposed gating models. PMID:25545271

  17. Selective excitation enables assignment of proton resonances and (1)H-(1)H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy.

    PubMed

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-07-21

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of (1)H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as (13)C or (15)N. In this method, after the initial preparation of proton magnetization and cross-polarization to (13)C nuclei, transverse magnetization of desired (13)C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific (13)C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of (1)H-(1)H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids. PMID:26203019

  18. Analysis of metabolic characteristics in a rat model of chronic pancreatitis using high-resolution magic-angle spinning nuclear magnetic resonance spectroscopy.

    PubMed

    Tian, Bing; Ma, Chao; Wang, Jian; Pan, Chun-Shu; Yang, Gen-Jin; Lu, Jian-Ping

    2015-01-01

    Pathological and metabolic alterations co-exist and co-develop in the progression of chronic pancreatitis (CP). The aim of the present study was to investigate the metabolic characteristics and disease severity of a rat model of CP in order to determine associations in the observed pathology and the metabolites of CP using high-resolution magic-angle spinning nuclear magnetic resonance spectroscopy (HR-MAS NMR). Wistar rats (n=36) were randomly assigned into 6 groups (n=6 per group). CP was established by administering dibutyltin dichloride solution into the tail vein. After 0, 7, 14, 21, 28 and 35 days, the pancreatic tissues were collected for pathological scoring or for HR-MAS NMR. Correlation analyses between the major pathological scores and the integral areas of the major metabolites were determined. The most representative metabolites, aspartate, betaine and fatty acids, were identified as possessing the greatest discriminatory significance. The Spearman's rank correlation coefficients between the pathology and metabolites of the pancreatic tissues were as follows: Betaine and fibrosis, 0.454 (P=0.044); betaine and inflammatory cell infiltration, 0.716 (P=0.0001); aspartate and fibrosis, -0.768 (P=0.0001); aspartate and inflammatory cell infiltration, -0.394 (P=0.085); fatty acid and fibrosis, -0.764 (P=0.0001); and fatty acid and inflammatory cell infiltration, -0.619 (P=0.004). The metabolite betaine positively correlated with fibrosis and inflammatory cell infiltration in CP. In addition, aspartate negatively correlated with fibrosis, but exhibited no significant correlation with inflammatory cell infiltration. Furthermore, the presence of fatty acids negatively correlated with fibrosis and inflammatory cell infiltration in CP. HR-MAS NMR may be used to analyze metabolic characteristics in a rat model of different degrees of chronic pancreatitis. PMID:25338744

  19. A Large Sample Volume Magic Angle Spinning Nuclear Magnetic Resonance Probe for In-Situ Investigations with Constant Flow of Reactants

    SciTech Connect

    Hu, Jian Z.; Sears, Jesse A.; Mehta, Hardeep S.; Ford, Joseph J.; Kwak, Ja Hun; Zhu, Kake; Wang, Yong; Liu, Jun; Hoyt, David W.; Peden, Charles HF

    2012-02-21

    A large-sample-volume constant-flow magic angle sample spinning (CF-MAS) NMR probe is reported for in-situ studies of the reaction dynamics, stable intermediates/transition states, and mechanisms of catalytic reactions. In our approach, the reactants are introduced into the catalyst bed using a fixed tube at one end of the MAS rotor while a second fixed tube, linked to a vacuum pump, is attached at the other end of the rotor. The pressure difference between both ends of the catalyst bed inside the sample cell space forces the reactants flowing through the catalyst bed, which improves the diffusion of the reactants and products. This design allows the use of a large sample volume for enhanced sensitivity and thus permitting in-situ 13C CF-MAS studies at natural abundance. As an example of application, we show that reactants, products and reaction transition states associated with the 2-butanol dehydration reaction over a mesoporous silicalite supported heteropoly acid catalyst (HPA/meso-silicalite-1) can all be detected in a single 13C CF-MAS NMR spectrum at natural abundance. Coke products can also be detected at natural 13C abundance and under the stopped flow condition. Furthermore, 1H CF-MAS NMR is used to identify the surface functional groups of HPA/meso-silicalite-1 under the condition of in-situ drying . We also show that the reaction dynamics of 2-butanol dehydration using HPA/meso-silicalite-1 as a catalyst can be explored using 1H CF-MAS NMR.

  20. Selective excitation enables assignment of proton resonances and 1H-1H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-07-01

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of 1H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as 13C or 15N. In this method, after the initial preparation of proton magnetization and cross-polarization to 13C nuclei, transverse magnetization of desired 13C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific 13C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of 1H-1H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.

  1. Selective excitation enables assignment of proton resonances and {sup 1}H-{sup 1}H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy

    SciTech Connect

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-07-21

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of {sup 1}H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as {sup 13}C or {sup 15}N. In this method, after the initial preparation of proton magnetization and cross-polarization to {sup 13}C nuclei, transverse magnetization of desired {sup 13}C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific {sup 13}C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of {sup 1}H-{sup 1}H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.

  2. Assessment of a 1H high-resolution magic angle spinning NMR spectroscopy procedure for free sugars quantification in intact plant tissue.

    PubMed

    Delgado-Goñi, Teresa; Campo, Sonia; Martín-Sitjar, Juana; Cabañas, Miquel E; San Segundo, Blanca; Arús, Carles

    2013-08-01

    In most plants, sucrose is the primary product of photosynthesis, the transport form of assimilated carbon, and also one of the main factors determining sweetness in fresh fruits. Traditional methods for sugar quantification (mainly sucrose, glucose and fructose) require obtaining crude plant extracts, which sometimes involve substantial sample manipulation, making the process time-consuming and increasing the risk of sample degradation. Here, we describe and validate a fast method to determine sugar content in intact plant tissue by using high-resolution magic angle spinning nuclear magnetic resonance spectroscopy (HR-MAS NMR). The HR-MAS NMR method was used for quantifying sucrose, glucose and fructose in mesocarp tissues from melon fruits (Cucumis melo var. reticulatus and Cucumis melo var. cantalupensis). The resulting sugar content varied among individual melons, ranging from 1.4 to 7.3 g of sucrose, 0.4-2.5 g of glucose; and 0.73-2.83 g of fructose (values per 100 g fw). These values were in agreement with those described in the literature for melon fruit tissue, and no significant differences were found when comparing them with those obtained using the traditional, enzymatic procedure, on melon tissue extracts. The HR-MAS NMR method offers a fast (usually <30 min) and sensitive method for sugar quantification in intact plant tissues, it requires a small amount of tissue (typically 50 mg fw) and avoids the interferences and risks associated with obtaining plant extracts. Furthermore, this method might also allow the quantification of additional metabolites detectable in the plant tissue NMR spectrum. PMID:23824526

  3. High-resolution magic angle spinning and 1H magnetic resonance spectroscopy reveal significantly altered neuronal metabolite profiles in CLN1 but not in CLN3.

    PubMed

    Sitter, Beathe; Autti, Taina; Tyynelä, Jaana; Sonnewald, Ursula; Bathen, Tone F; Puranen, Johanna; Santavuori, Pirkko; Haltia, Matti J; Paetau, Anders; Polvikoski, Tuomo; Gribbestad, Ingrid S; Häkkinen, Anna-Maija

    2004-09-01

    The neuronal ceroid lipofuscinoses (NCLs) are among the most severe inherited progressive neurodegenerative disorders of children. The purpose of this study was to compare the in vivo 1.5-T 1H magnetic resonance (MR) and ex vivo 14.3-T high-resolution (HR) magic angle spinning (MAS) 1H MR brain spectra of patients with infantile (CLN1) and juvenile (CLN3) types of NCL, to obtain detailed information about the alterations in the neuronal metabolite profiles in these diseases and to test the suitability of the ex vivo HR MAS (1)H MRS technique in analysis of autopsy brain tissue. Ex vivo spectra from CLN1 autopsy brain tissue (n = 9) significantly differed from those of the control (n = 9) and CLN3 (n = 5) groups, although no differences were found between the CLN3 and the control groups. Principal component analysis of ex vivo data showed that decreased levels of N-acetylaspartate (NAA), gamma-aminobutyric acid (GABA), glutamine, and glutamate as well as increased levels of inositols characterized the CLN1 spectra. Also, the intensity ratio of lipid methylene/methyl protons was decreased in spectra of CLN1 brain tissue compared with CLN3 and control brain tissue. In concordance with the ex vivo data, the in vivo spectra of late-stage patients with CLN1 (n = 3) revealed a dramatic decrease of NAA and a proportional increase of myo-inositol and lipids compared with control subjects. Again, the spectra of patients with CLN3 (n = 13) did not differ from those of controls (n = 15). In conclusion, the ex vivo and in vivo spectroscopic findings were in good agreement within all analyzed groups and revealed significant alterations in metabolite profiles in CLN1 brain tissue but not in CLN3 compared with controls. Furthermore, HR MAS 1H MR spectra facilitated refined detection of neuronal metabolites, including GABA, and composition of lipids in the autopsy brain tissue of NCL patients. PMID:15352223

  4. Carbon-13 cross-polarization magic-angle-spinning nuclear magnetic resonance investigation of the interactions between maleic anhydride grafted polypropylene and wood polymers.

    PubMed

    Rude, Erica; Laborie, Marie-Pierre G

    2008-05-01

    The chemical interactions between maleic anhydride grafted polypropylene (MAPP) and wood were studied with solid-state carbon-13 cross-polarization magic-angle-spinning nuclear magnetic resonance ((13)C CPMAS NMR) spectroscopy. MAPP was synthesized with 100% (13)C enrichment at the C(1) and C(4) carbons to allow detection of the [1,4-(13)C(2)]MAPP functional groups and was melt blended with cellulose, lignin, and maple wood. In the cellulose/MAPP blend, changes in (13)C CPMAS NMR corrected signal intensities for the anhydride and dicarboxylic maleic acid functionalities suggested that esterification may have occurred predominantly from the more numerous diacid carbons. A single proton longitudinal relaxation in the rotating frame, (H)T(1rho), for the MAPP and the cellulose carbons in the blend suggested that they were spin coupled, i.e., homogeneous on a 10-200 Angstrom scale. Esterification was also suggested in the lignin/MAPP blend. Furthermore, the more significant changes in the intensities of the carbonyl signals and (H)T(1rho) values suggested that lignin may be more reactive to MAPP than cellulose. Finally, when maple was melt blended with MAPP, the same trends in the (13)C CP-MAS NMR spectra and (H)T(1rho) behavior were observed as when MAPP was blended with cellulose or lignin. This study therefore clarifies that during melt compounding of wood with MAPP, esterification occurs with wood polymers, preferentially with lignin. Understanding the interactions of MAPP with wood is of significance for the development of natural-fiber-reinforced thermoplastic composites. PMID:18498698

  5. Magic angle spinning nuclear magnetic resonance characterization of voltage-dependent anion channel gating in two-dimensional lipid crystalline bilayers.

    PubMed

    Eddy, Matthew T; Andreas, Loren; Teijido, Oscar; Su, Yongchao; Clark, Lindsay; Noskov, Sergei Y; Wagner, Gerhard; Rostovtseva, Tatiana K; Griffin, Robert G

    2015-02-01

    The N-terminus of the voltage-dependent anion channel (VDAC) has been proposed to contain the mechanistically important gating helices that modulate channel opening and closing. In this study, we utilize magic angle spinning nuclear magnetic resonance (MAS NMR) to determine the location and structure of the N-terminus for functional channels in lipid bilayers by measuring long-range (13)C-(13)C distances between residues in the N-terminus and other domains of VDAC reconstituted into DMPC lipid bilayers. Our structural studies show that the distance between A14 Cβ in the N-terminal helix and S193 Cβ is ∼4-6 Å. Furthermore, VDAC phosphorylation by a mitochondrial kinase at residue S193 has been claimed to delay mitochondrial cell death by causing a conformational change that closes the channel, and a VDAC-Ser193Glu mutant has been reported to show properties very similar to those of phosphorylated VDAC in a cellular context. We expressed VDAC-S193E and reconstituted it into DMPC lipid bilayers. Two-dimensional (13)C-(13)C correlation experiments showed chemical shift perturbations for residues located in the N-terminus, indicating possible structural perturbations to that region. However, electrophysiological data recorded on VDAC-S193E showed that channel characteristics were identical to those of wild type samples, indicating that phosphorylation of S193 does not directly affect channel gating. The combination of NMR and electrophysiological results allows us to discuss the validity of proposed gating models. PMID:25545271

  6. Enhanced sensitivity and resolution in (1)H solid-state NMR spectroscopy of paramagnetic complexes under very fast magic angle spinning.

    PubMed

    Wickramasinghe, Nalinda P; Shaibat, Medhat; Ishii, Yoshitaka

    2005-04-27

    High-resolution NMR spectroscopy for paramagnetic complexes in solids has been rarely performed because of its limited sensitivity and resolution due to large paramagnetic shifts and associated technical difficulties. The present study demonstrates that magic angle spinning (MAS) at speeds exceeding 20 kHz provides unusually high sensitivity and excellent resolution in 1H solid-state NMR (SSNMR) for paramagnetic systems. Spinning-speed dependence of 1H MAS spectra showed that very fast MAS (VFMAS) at 24-28 kHz enhanced sensitivity by a factor of 12-18, compared with the sensitivity of 1H SSNMR spectra under moderate MAS at 10 kHz, for Cu(dl-alanine)2.H2O and Mn(acac)3, for which the spectral ranges due to 1H paramagnetic shifts reach 200 and 1000 ppm, respectively. It was theoretically and experimentally confirmed that the absolute sensitivity of 1H VFMAS for small paramagnetic complexes such as Cu(dl-alanine)2 can be an order of magnitude higher than that of equimolar diamagnetic ligands because of short 1H T1 ( approximately 1 ms) of the paramagnetic systems and improved sensitivity under VFMAS. On the basis of this demonstrated high sensitivity, 1H SSNMR micro analysis of paramagnetic systems in a nanomole scale is proposed. Applications were performed on two polymorphs of Cu(II)(8-quinolinol)2, which is a suppressor of human cancer cells. It was demonstrated that 1H VFMAS SSNMR spectra accumulated for 20 nmol of the polycrystalline samples in 10 min enabled one to distinguish alpha- and beta-forms of Cu(II)(8-quinolinol)2 on the basis of shift positions and line widths. PMID:15839671

  7. Application of the Floquet theory to multiple quantum NMR of dipolar-coupled multi-spin systems under magic angle spinning

    NASA Astrophysics Data System (ADS)

    Filip, Claudiu; Bertmer, Marko; Demco, Dan E.; Blümich, Bernhard

    A new analytical Liouville-space representation of the time-propagator under magic angle spinning (MAS) is introduced using the formalized quantum Floquet theory. This approach has the advantage that it is applicable to the analysis of any type of NMR experiment where MAS is combined with multiple-pulse excitation. General relationships describing the spectral parameters in multiple-quantum (MQ) MAS spectra are derived in this representation. Their use is illustrated with an application to double-quantum (DQ) NMR spectra of dipolarcoupled multi-spin systems. Corresponding to the separation of the MAS time-propagator into a rotor modulated and a dephasing component, two distinct mechanisms for DQ excitation are identified. One of them exploits the rotor-modulated component to excite DQ coherences through dipolar-recoupling techniques, which are familiar for spin pairs. Analytical expressions of the integral intensities and linewidths in the resulting DQ sideband pattern are derived in the form of power series expansions of the inverse rotor frequency, of which coefficients depend on structural parameters. In a multi-spin system they can most reliably be extracted in the fast spinning regime. The other mechanism exploits the dephasing component, which is characteristic to multi-spin systems only. This is shown to give rise to DQ coherences by free evolution at full rotor periods. The possibility to exploit it for selective excitation of higher order MQ coherences is discussed. In either case, the dephasing component also leads to residual broadening. The main results of the theoretical developments are demonstrated experimentally on adamantane.

  8. Magic-angle spinning NMR study of deuterium site occupancy and dynamics in ZrNiD1.0 and ZrNiD3.0

    NASA Astrophysics Data System (ADS)

    Adolphi, Natalie L.; Badola, Sharwari; Browder, Lisa A.; Bowman, R. C.

    2002-01-01

    Both static and magic-angle spinning (MAS) 2H nuclear magnetic resonance spectroscopy indicate that two inequivalent sites are occupied in ZrNiD3.0, in a 2:1 ratio, in agreement with previous work. The sites occupied in the trihydride phase have been previously identified as Zr3Ni and Zr3Ni2. In ZrNiD1.0, two well-resolved lines of equal intensity are observed in the MAS spectrum at temperatures<220 K, indicating that two other inequivalent sites are occupied in a 1:1 ratio, in contrast with previous reports that only one type of site (Zr4Ni2) is occupied in the monohydride (β) phase at room temperature and above. The temperature dependences of both MAS and static ZrNiD1.0 spectra indicate that no phase transitions occur over the entire temperature range studied, 160-500 K. The deuterium hopping rate in ZrNiD1.0 is determined from characteristic changes in the MAS spectra as a function of temperature; the motion is consistent with an activation energy Ea≅0.44 eV assuming a rate prefactor 1/τ0~1013 s-1. In ZrNiD3.0, the rate of deuterium motion is determined from signatures of motion in the static and MAS spectra. The motion in ZrNiD3.0 is consistent with an activation energy Ea≅0.62 eV assuming a rate prefactor of ~1013 s-1.

  9. Nanostructures of Mg0.65Ti0.35Dx studied with x-ray diffraction, neutron diffraction, and magic-angle-spinning H2 NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Srinivasan, S.; Magusin, P. C. M. M.; Kalisvaart, W. P.; Notten, P. H. L.; Cuevas, F.; Latroche, M.; van Santen, R. A.

    2010-02-01

    Magnesium transition-metal alloys have a high hydrogen-storage capacity and show improved hydrogen-uptake and -release kinetics compared to magnesium alone. In the present study we have investigated the structure of bulk magnesium-titanium deuteride Mg0.65Ti0.35Dx prepared via mechanical alloying and gas-phase deuterium absorption by combined use of x-ray diffraction (XRD), neutron diffraction, and magic-angle-spinning H2 nuclear magnetic resonance (NMR). The initial ball-milled alloy has two XRD-distinct Mg and Ti fcc phases. Even after prolonged exposure to deuterium gas at 75 bar and 175°C the materials with and without palladium catalyst are only partly deuterated. Deuterium loading causes the formation of, on the one hand, bct (rutile) MgD2 nanodomains with interdispersed TiDy layers and, on the other hand, a separate fcc (fluorite) TiDz phase. The TiDy phase is XRD invisible, but shows clearly up at a H2 NMR shift of -43ppm between the shift of MgD2 (3 ppm) and the Knight shift of the TiDz phase (-143ppm) . Exchange NMR indicates complete deuterium exchange at 25°C between the MgD2 and TiDy phase within 1 s, as consistent with intimate contacts between these phases. Combined analysis of the XRD and NMR peak areas suggests that the deuterium concentrations y and z in the TiDy and TiDz domains are about 1.5 and 2.0, respectively. Comparing the intrinsic cell parameters of rutile MgH2 and fluorite TiH2 , we propose that stabilization of the mixed nanocomposite may arise from a coherent coupling between the crystal structures of the rutile MgD2 nanodomains and the thin layers of fcc TiDy .

  10. High-resolution aluminum-27 solid-state magic-angle sample-spinning nuclear magnetic resonance spectroscopic study of AlCl sub 3 -tetrahydrofuran complexes

    SciTech Connect

    Han, Oc Hee; Oldfield, E. )

    1990-09-19

    The authors have obtained {sup 27}Al solid-state nuclear magnetic resonance (NMR) spectra of several AlCl{sub 3}-THF complexes, using magic-angle sample-spinning (MASS) NMR at high field. The authors results suggest that the isotropic chemical shifts ({delta}{sub i}) occur in relatively well defined regions for 4-, 5-, and 6-coordinate species (AlCl{sub 4}{sup {minus}}, {approximately} 103 ppm; AlCl{sub 3}{center dot}THF, {approximately} 99 ppm; trans-AlCl{sub 3}{center dot}2THF, {approximately} 60 ppM; trans-(AlCl{sub 2}(THF){sub 4}){sup +}, {approximately} 14 ppM), as found previously with aluminum oxo compounds. They also find that theoretically calculated average nuclear quadrupole coupling constants (e{sup 2}qQ/h) (trans-(AlCl{sub 2}(THF){sub 4}){sup +}, {approximately} 6.3 MHz; trans-AlCl{sub 3}{center dot}2THF, {approximately} 4.6 MHz; AlCl{sub 3}{center dot}THF, {approximately} 3.0 MHz; AlCl{sub 4}{sup {minus}}, 0 MHz) are in good accord with experimentally determined nuclear quadrupole coupling constants, determined from computer simulations of the MASS NMR spectra (trans-(AlCl{sub 2}(THF){sub 4}){sup +}, 6.4 MHz; trans-AlCl{sub 3}{center dot}2THF, 4.9 MHz; AlCl{sub 3}{center dot}THF, 4.7 MHz; AlCl{sub 4}{sup {minus}}, 0.3 MHz). Both {sup 27}Al {delta}{sub i} and e{sup 2}qQ/h determinations appear to be useful as probes of structure in these systems, and thus offer a facile means of monitoring various solid-state reactions. 14 refs., 3 figs., 3 tabs.

  11. Cluster rotational bands in 11B

    NASA Astrophysics Data System (ADS)

    Danilov, A. N.; Demyanova, A. S.; Ogloblin, A. A.; Belyaeva, T. L.; Goncharov, S. A.; Trzaska, W.

    2016-05-01

    Differential cross-sections of 11B+α inelastic scattering at E(α) =65 MeV leading to most of the known 11B states at excitation energies up to 14 MeV were measured [1]. The data analysis was done using Modified diffraction model (MDM) [2] allowing determining radii of excited states. Radii of the states with excitation energies less than ˜ 7 MeV coincide with the radius of the ground state with an accuracy not less than 0.1 - 0.15 fm. This result is consistent with traditional view on shell structure of low-lying states in 11B. Most of the observed high-energy excited states are distributed among four rotational bands. Moments of inertia of band states are close to the moment of inertia of the Hoyle state of 12C. The calculated radii, related to these bands, are 0.7 - 1.0 fm larger than the radius of the ground state, and are close to the Hoyle state radius. These results are in agreement with existing predictions about various cluster structure of 11B at high excitation energies.

  12. Breakup of {sup 11}B at low relative energies

    SciTech Connect

    Bryan, D.C.; White, C.A.; Wolfs, F.L.H.

    1993-04-01

    The authors have used the segmented focal plane detector of the Rochester Enge split-pole spectrograph to study the breakup of 87 MeV {sup 11}B ions incident on a {sup 12}C target into {sup 4}He and {sup 7}Li fragments at relative energies between 0 MeV and 4 MeV and at laboratory angles between 7.5{degrees} and 25{degrees}. The total kinetic energy spectra of the breakup fragments is dominated by elastic breakup (all reaction products are left in their ground state). The reconstructed relative energy spectra for elastic breakup are dominated by sequential breakup of {sup 11}B via the 9.27 MeV, 10.26 MeV, and 10.60 MeV excited states in {sup 11}B. The measured yields are compared with the calculated cross sections of exciting these states, using DWBA calculations and B(EL) values obtained from radiative capture measurements of {sup 4}He and {sup 7}Li.

  13. Comparisons of lipid dynamics and packing in fully interdigitated monoarachidoylphosphatidylcholine and non-interdigitated dipalmitoylphosphatidylcholine bilayers: cross polarization/magic angle spinning 13C-NMR studies.

    PubMed

    Wu, W G; Chi, L M

    1990-07-24

    13C-NMR spectra have been obtained at 50.3 MHz for monoarachidoylphosphatidylcholine (MAPC) and dipalmitoylphosphatidylcholine (DPPC) dispersions from 25 degrees C to 55 degrees C and for DPPC polycrystals at 25 degrees C using the cross polarization/magic angle spinning technique. Differential scanning calorimetric studies on DPPC and MAPC dispersions show comparable lipid phase transitions with transition temperatures at 41 degrees C and 45 degrees C, respectively, and thus enable the comparison of thermal, structural and dynamic differences between these two systems at corresponding temperatures. Conformational-dependent 13C chemical shift studies on DPPC dispersions demonstrate not only the coexistence of the tilted gel (L beta') and liquid-crystalline (L alpha) phases in the rippled gel (P beta') phase, but also the presence of an intermediate third microscopic phase as evidenced by three resolvable peaks for omega - 1 methylene carbon signals at the temperature interval between Tp and Tm. By comparing chemical shifts of MAPC in the hydrocarbon chain region with those of DPPC at similar reduced temperatures, it can be concluded that the packings are perturbed markedly in the middle segment of the fatty acyl chain during the lamellar to micellar transition. However, terminal methylene and methyl groups of interdigitated MAPC lamellae were found to be more ordered than those of non-interdigitated DPPC bilayers in the gel state. Interestingly, the terminal methyl groups of MAPC in the micelles remain to be relatively ordered; in fact, they are more ordered than the corresponding acyl chain end of DPPC in the liquid-crystalline state. Analysis of data obtained from rotating frame proton spin-lattice relaxation measurements shows a highly mobile phosphocholine headgroup, a rigid carbonyl group and an ordered hydrocarbon chain for lamellar MAPC in the interdigitated state. Furthermore, results suggest that free rotations of the glycerol C2-C3 bond within MAPC

  14. Site-resolved multiple-quantum filtered correlations and distance measurements by magic-angle spinning NMR: Theory and applications to spins with weak to vanishing quadrupolar couplings.

    PubMed

    Eliav, U; Haimovich, A; Goldbourt, A

    2016-01-14

    We discuss and analyze four magic-angle spinning solid-state NMR methods that can be used to measure internuclear distances and to obtain correlation spectra between a spin I = 1/2 and a half-integer spin S > 1/2 having a small quadrupolar coupling constant. Three of the methods are based on the heteronuclear multiple-quantum and single-quantum correlation experiments, that is, high rank tensors that involve the half spin and the quadrupolar spin are generated. Here, both zero and single-quantum coherence of the half spins are allowed and various coherence orders of the quadrupolar spin are generated, and filtered, via active recoupling of the dipolar interaction. As a result of generating coherence orders larger than one, the spectral resolution for the quadrupolar nucleus increases linearly with the coherence order. Since the formation of high rank tensors is independent of the existence of a finite quadrupolar interaction, these experiments are also suitable to materials in which there is high symmetry around the quadrupolar spin. A fourth experiment is based on the initial quadrupolar-driven excitation of symmetric high order coherences (up to p = 2S, where S is the spin number) and subsequently generating by the heteronuclear dipolar interaction higher rank (l + 1 or higher) tensors that involve also the half spins. Due to the nature of this technique, it also provides information on the relative orientations of the quadrupolar and dipolar interaction tensors. For the ideal case in which the pulses are sufficiently strong with respect to other interactions, we derive analytical expressions for all experiments as well as for the transferred echo double resonance experiment involving a quadrupolar spin. We show by comparison of the fitting of simulations and the analytical expressions to experimental data that the analytical expressions are sufficiently accurate to provide experimental (7)Li-(13)C distances in a complex of lithium, glycine, and water. Discussion

  15. Magic-angle spinning NMR studies of molecular organization in multibilayers formed by 1-octadecanoyl-2-decanoyl-sn-glycero-3-phosphocholine.

    PubMed Central

    Halladay, H N; Stark, R E; Ali, S; Bittman, R

    1990-01-01

    Magic-angle spinning 1H and 13C nuclear magnetic resonance (NMR) have been employed to study 50%-by-weight aqueous dispersions of 1-octadecanoyl-2-decanoyl-sn-glycero-3-phosphocholine (C[18]:C[10]PC) and 1-octadecanoyl-2-d19-decanoyl-PC (C[18]:C[10]PC-d19), mixed-chain phospholipids which can form interdigitated multibilayers. The 1H NMR linewidth for methyl protons of the choline headgroup has been used to monitor the liquid crystalline-to-gel (LC-to-G) phase transition and confirm variations between freezing and melting temperatures. Both 1H and 13C spin-lattice relaxation times indicate unusual restrictions on segmental reorientation at megahertz frequencies for C(18):C(10)PC as compared with symmetric-chain species in the LC state; nevertheless each chemical moiety of the mixed-chain phospholipid exhibits motional behavior that may be classified as liquidlike. Two-dimensional nuclear Overhauser spectroscopy (NOESY) on C(18):C(10)PC and C(18):C(10)PC-d19 reveals cross-peaks between the omega-methyl protons of the C18 chain and the N-methyl protons of the phosphocholine headgroup, and several experimental and theoretical considerations argue against an interpretation based on spin diffusion. Using NMR relaxation times and NOESY connectivities along with a computational formalism for four-spin systems (Keepers, J. W., and T. L. James. 1984. J. Magn. Reson. 57:404-426), an estimate of 3.5 A is obtained for the average distance between the omega-methyl protons of the C18 chain and the N-methyl protons of the phosphocholine headgroup. This finding is consistent with a degree of interdigitation similar to that proposed for organized assemblies of gel-state phosphatidylcholine molecules with widely disparate acyl-chain lengths (Hui, S. W., and C.-H. Huang. 1986. Biochemistry. 25:1330-1335); however, acyl-chain bendback or other intermolecular interactions may also contribute to the NOESY results. For multibilayers of C(18):C(10)PC in the gel phase, 13C chemical

  16. Sensitivity enhanced (14)N/(14)N correlations to probe inter-beta-sheet interactions using fast magic angle spinning solid-state NMR in biological solids.

    PubMed

    Pandey, Manoj Kumar; Amoureux, Jean-Paul; Asakura, Tetsuo; Nishiyama, Yusuke

    2016-08-10

    (14)N/(14)N correlations are vital for structural studies of solid samples, especially those in which (15)N isotopic enrichment is challenging, time-consuming and expensive. Although (14)N nuclei have high isotopic abundance (99.6%), there are inherent difficulties in observing (14)N/(14)N correlations due to limited resolution and sensitivity related to: (i) low (14)N gyromagnetic ratio (γ), (ii) large (14)N quadrupolar couplings, (iii) integer (14)N spin quantum number (I = 1), and (iv) very weak (14)N-(14)N dipolar couplings. Previously, we demonstrated a proton-detected 3D (14)N/(14)N/(1)H correlation experiment at fast magic angle spinning (MAS) on l-histidine·HCl·H2O utilizing a through-bond (J) and residual dipolar-splitting (RDS) based heteronuclear multiple quantum correlation (J-HMQC) sequence mediated through (1)H/(1)H radio-frequency driven recoupling (RFDR). As an extension of our previous work, in this study we show the utility of dipolar-based HMQC (D-HMQC) in combination with (1)H/(1)H RFDR mixing to obtain sensitivity enhanced (14)N/(14)N correlations in more complex biological solids such as a glycyl-l-alanine (Gly-l-Ala) dipeptide, and parallel (P) and antiparallel (AP) β-strand alanine tripeptides (P-(Ala)3 and AP-(Ala)3, respectively). These systems highlight the mandatory necessity of 3D (14)N/(14)N/(1)H measurements to get (14)N/(14)N correlations when the amide proton resonances are overlapped. Moreover, the application of long selective (14)N pulses, instead of short hard ones, is shown to improve the sensitivity. Globally, we demonstrate that replacing J-scalar with dipolar interaction and hard- with selective-(14)N pulses allows gaining a factor of ca. 360 in experimental time. On the basis of intermolecular NH/NH distances and (14)N quadrupolar tensor orientations, (14)N/(14)N correlations are effectively utilized to make a clear distinction between the parallel and antiparallel arrangements of the β-strands in (Ala)3 through the

  17. Mechanism of Solid-State Thermolysis of Ammonia Boraine: 15N NMR Study Using Fast Magic-Angle Spinning and Dynamic Nuclear Polarization

    SciTech Connect

    Kobayashi, Takeshi; Gupta, Shalabh; Caporini, Marc A; Pecharsky, Vitalij K; Pruski, Marek

    2014-08-28

    The solid-state thermolysis of ammonia borane (NH3BH3, AB) was explored using state-of-the-art 15N solid-state NMR spectroscopy, including 2D indirectly detected 1H{15N} heteronuclear correlation and dynamic nuclear polarization (DNP)-enhanced 15N{1H} cross-polarization experiments as well as 11B NMR. The complementary use of 15N and 11B NMR experiments, supported by density functional theory calculations of the chemical shift tensors, provided insights into the dehydrogenation mechanism of AB—insights that have not been available by 11B NMR alone. Specifically, highly branched polyaminoborane derivatives were shown to form from AB via oligomerization in the “head-to-tail” manner, which then transform directly into hexagonal boron nitride analog through the dehydrocyclization reaction, bypassing the formation of polyiminoborane.

  18. Exploring the conformational energy landscape of glassy disaccharides by cross polarization magic angle spinning 13C nuclear magnetic resonance and numerical simulations. II. Enhanced molecular flexibility in amorphous trehalose

    NASA Astrophysics Data System (ADS)

    Lefort, Ronan; Bordat, Patrice; Cesaro, Attilio; Descamps, Marc

    2007-01-01

    This paper uses chemical shift surfaces to simulate experimental C13 cross polarization magic angle spinning spectra for amorphous solid state disaccharides, paying particular attention to the glycosidic linkage atoms in trehalose, sucrose, and lactose. The combination of molecular mechanics with density functional theory/gauge invariant atomic orbital ab initio methods provides reliable structural information on the conformational distribution in the glass. The results are interpreted in terms of an enhanced flexibility that trehalose possesses in the amorphous solid state, at least on the time scale of C13 nuclear magnetic resonance measurements. Implications of these findings for the fragility of trehalose glass and bioprotectant action are discussed.

  19. Magic Mirrors

    ERIC Educational Resources Information Center

    Mills, Allan

    2011-01-01

    "Magic mirrors" were so named because, when they were positioned to throw a reflected patch of sunlight on a nearby wall, this area contained an outline of a design cast on the back of the (bronze) mirror. Investigations begun in the 19th century showed that this was a response to heavy localized pressures exerted on the face of the thin mirror…

  20. Mummies & Magic.

    ERIC Educational Resources Information Center

    Casey, Jeanne E.

    1989-01-01

    Covers the cultural and aesthetic significance of Egyptian mummies, as explained in an exhibition at Boston's Museum of Fine Arts. The display, "Mummies & Magic: The Funerary Arts of Ancient Egypt," allowed for restoration work which did much to advance modern knowledge of Egyptian culture and funerary art. (LS)

  1. Magical Boxes

    ERIC Educational Resources Information Center

    Costello, Judith

    2005-01-01

    Students get excited when they realize that they can transform a flat sheet of paper into a box. By using different sizes of paper, they can make different sizes of boxes and put a box inside a box, inside a box. These magical boxes within boxes can contain unwanted emotions or special treasures. The project described in this article incorporates…

  2. Matisse Magic.

    ERIC Educational Resources Information Center

    Gibson, Marcia

    2002-01-01

    Presents an art lesson in which kindergarten and first-grade students learn about Henri Matisse and his art work. Explains that the students use "Model Magic" to create Matisse style face refrigerator magnets. Discusses in detail how to create the magnets. (CMK)

  3. Study of the ferroelastic phase transition in the tetraethylammonium compound [N(C2H5)4]2ZnBr4 by magic-angle spinning and static NMR

    NASA Astrophysics Data System (ADS)

    Lim, Ae Ran

    2016-03-01

    The ferroelastic phase transition of tetraethylammonium compound [N(C2H5)4]2ZnBr4 at the phase transition temperature (TC) = 283 K was characterized by magic-angle spinning (MAS) and static nuclear magnetic resonance (NMR), and confirmed by optical polarizing spectroscopy. The structural geometry near TC was studied in terms of the chemical shifts and the spin-lattice relaxation times T1ρ in the rotating frame for 1H MAS NMR and 13C cross-polarization (CP)/MAS NMR. The two inequivalent ethyl groups were distinguishable in the 13C NMR spectrum, and the T1ρ results indicate that they undergo tumbling motion above TC in a coupled manner. From the 14N NMR results, the two nitrogen nuclei in the N(C2H5)4+ ions were distinguishable above TC, and the splitting in the spectra below TC was related to the ferroelastic domains with different orientations.

  4. A study of conformational stability of poly(L-alanine), poly(L-valine), and poly(L-alanine)/poly(L-valine) blends in the solid state by (13)C cross-polarization/magic angle spinning NMR.

    PubMed

    Murata, Katsuyoshi; Kuroki, Shigeki; Kimura, Hideaki; Ando, Isao

    2002-06-01

    13C cross-polarization/magic angle spinning (CP/MAS) NMR and (1)H T(1rho) experiments of poly(L-alanine) (PLA), poly(L-valine) (PLV), and PLA/PLV blends have been carried out in order to elucidate the conformational stability of the polypeptides in the solid state. These were prepared by adding a trifluoroacetic acid (TFA) solution of the polymer with a 2.0 wt/wt % of sulfuric acid (H(2)SO(4)) to alkaline water. From these experimental results, it is clarified that the conformations of PLA and PLV in their blends are strongly influenced by intermolecular hydrogen-bonding interactions that cause their miscibility at the molecular level. PMID:11948439

  5. 27Al magic-angle spinning nuclear magnetic resonance satellite transition spectroscopy of glasses in the system K2O-Al2O3-SiO2.

    PubMed

    Mundus, C; Müller-Warmuth, W

    1995-10-01

    27Al magic-angle spinning nuclear magnetic resonance satellite transition spectroscopy at 78 MHz has been applied to determine (true) chemical shift and quadrupole coupling parameters of glasses in the system K2O-Al2O3-SiO2 with 60-80 mol% SiO2 and K2O concentrations between 0 and 24 mol%. The powdered crystalline aluminosilicates andalusite and sillimanite have also been examined. In the glasses, all Al appears to be tetrahedrally bound in the aluminosilicate network unless x = mol% K2O:mol% Al2O3 becomes extremely small. Upon decreasing x the distortion of the tetrahedral Al(OSi)4 units increases in steps, and possible explanations are discussed. Six-coordinated aluminum observed for x < 0.2 is connected with the occurrence of interstitial Al3+ ions which charge-compensate the AlO4 units in addition to K+. PMID:8748646

  6. Molecular and electron-spin structures of a ring-shaped mixed-valence polyoxovanadate (IV, V) studied by (11)B and (23)Na solid-state NMR spectroscopy and DFT calculations.

    PubMed

    Iijima, Takahiro; Yamase, Toshihiro; Nishimura, Katsuyuki

    2016-01-01

    (11)B and (23)Na solid-state nuclear magnetic resonance (NMR) spectra of ring-shaped paramagnetic crystals of H15[V7(IV)V5(V)B32O84Na4]·13H2O containing seven d(1) electrons from V(IV) were studied. Magic-angle-spinning (MAS) and multiple-quantum MAS NMR experiments were performed at moderate (9.4T) and ultrahigh magnetic fields (21.6T). The NMR parameters for quadrupole and isotropic chemical shift interactions were estimated by simulation of the NMR spectra and from relativistic density functional theory (DFT) calculations. Four Na ions incorporated into the framework were found to occupy four distinct sites with different populations. The DFT calculation showed that d(1) electrons with effectively one up-spin caused by strong antiferromagnetic interactions were delocalized over the 12V ions. PMID:27018827

  7. Identification of BCL11B as a regulator of adipogenesis.

    PubMed

    Inoue, Jun; Ihara, Yusuke; Tsukamoto, Daisuke; Yasumoto, Keisuke; Hashidume, Tsutomu; Kamimura, Kenya; Nakai, Yuji; Hirano, Shigeki; Shimizu, Makoto; Kominami, Ryo; Sato, Ryuichiro

    2016-01-01

    The differentiation of preadipocytes into adipocytes is controlled by several transcription factors, including peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), which are known as master regulators of adipogenesis. BCL11B is a zinc finger-type transcription factor that regulates the development of the skin and central nervous and immune systems. Here, we found that BCL11B was expressed in the white adipose tissue (WAT), particularly the subcutaneous WAT and that BCL11B(-/-) mice had a reduced amount of subcutaneous WAT. During adipogenesis, BCL11B expression transiently increased in 3T3-L1 preadipocytes and mouse embryonic fibroblasts (MEFs). The ability for adipogenesis was reduced in BCL11B knockdown 3T3-L1 cells and BCL11B(-/-) MEFs, whereas the ability for osteoblastogenesis was unaffected in BCL11B(-/-) MEFs. Luciferase reporter gene assays revealed that BCL11B stimulated C/EBPβ activity. Furthermore, the expression of downstream genes of the Wnt/β-catenin signaling pathway was not suppressed in BCL11B(-/-) MEFs during adipogenesis. Thus, this study identifies BCL11B as a novel regulator of adipogenesis, which works, at least in part, by stimulating C/EBPβ activity and suppressing the Wnt/β-catenin signaling pathway. PMID:27586877

  8. MAGIC highlights

    NASA Astrophysics Data System (ADS)

    López-Coto, Rubén

    2016-07-01

    The present generation of Imaging Air Cherenkov Telescopes (IACTs) has greatly improved our knowledge on the Very High Energy (VHE) side of our Universe. The MAGIC IACTs operate since 2004 with one telescope and since 2009 as a two telescope stereoscopic system. I will outline a few of our latest and most relevant results: the discovery of pulsed emission from the Crab pulsar at VHE, recently found to extend up to 400 GeV and along the "bridge" of the light curve, the measurement of the Crab nebula spectrum over three decades of energy, the discovery of VHE γ-ray emission from the PWN 3C 58, the very rapid emission of IC 310, in addition to dark matter studies. The results that will be described here and the planned deep observations in the next years will pave the path for the future generation of IACTs.

  9. One-two step transfer observed in 16O+11B nuclear system

    NASA Astrophysics Data System (ADS)

    Hamada, Sh.; Burtebayev, N.

    2015-06-01

    The angular distribution measurements for 16O ion beam elastically scattered from 11B target of thickness 32.9μg/cm2 at energy 22.4 MeV had been performed in the cyclotron DC-60 INP NNC RK. The previous measurements for 16O+11B nuclear system at energies 27, 30, 32.5 and 35 MeV showed an increase in the differential cross-section at backward angles due to the contribution of cluster transfer. Such transfer process could not be described in terms of optical model (OM); it could be described within the framework of distorted wave Born approximation method implemented in FRESCO code. Both one (5Li) and two-step transfer (proton transfer followed by Alpha transfer) were taken into considerations. We have extracted the spectroscopic amplitude (SA) for the configuration 16O→11B+5Li.

  10. The Versatile Magic Square.

    ERIC Educational Resources Information Center

    Watson, Gale A.

    2003-01-01

    Demonstrates the transformations that are possible to construct a variety of magic squares, including modifications to challenge students from elementary grades through algebra. Presents an example of using magic squares with students who have special needs. (YDS)

  11. Boron isotopes as pH proxy: A new look at boron speciation in deep-sea corals using 11B MAS NMR and EELS

    NASA Astrophysics Data System (ADS)

    Rollion-Bard, Claire; Blamart, Dominique; Trebosc, Julien; Tricot, Grégory; Mussi, Alexandre; Cuif, Jean-Pierre

    2011-02-01

    Dissolved boron in modern seawater occurs in the form of two species, trigonal boric acid B(OH) 3 and tetrahedral borate ion B(OH)4-. One of the key assumption in the use of boron isotopic compositions of carbonates as pH proxy is that only borate ions, B(OH)4-, are incorporated into the carbonate. Here, we investigate the speciation of boron in deep-sea coral microstructures ( Lophelia pertusa specimen) by using high field magic angle spinning nuclear magnetic resonance ( 11B MAS NMR) and electron energy-loss spectroscopy (EELS). We observe both boron coordination species, but in different proportions depending on the coral microstructure, i.e. centres of calcification versus fibres. These results suggest that careful sampling is necessary before performing boron isotopic measurements in deep-sea corals. By combining the proportions of B(OH) 3 and B(OH)4- determined by NMR and our previous ion microprobe boron isotope measurements, we propose a new equation for the relation between seawater pH and boron isotopic composition in deep-sea corals.

  12. Perception, Illusion, and Magic.

    ERIC Educational Resources Information Center

    Solomon, Paul R.

    1980-01-01

    Describes a psychology course in which magical illusions were used for teaching the principles of sensation and perception. Students read psychological, philosophical, historical, and magical literature on illusion, performed a magical illusion, and analyzed the illusion in terms of the psychological principles involved. (Author/KC)

  13. Shortening spin-lattice relaxation using a copper-chelated lipid at low-temperatures - A magic angle spinning solid-state NMR study on a membrane-bound protein.

    PubMed

    Yamamoto, Kazutoshi; Caporini, Marc A; Im, Sangchoul; Waskell, Lucy; Ramamoorthy, Ayyalusamy

    2013-12-01

    Inherent low sensitivity of NMR spectroscopy has been a major disadvantage, especially to study biomolecules like membrane proteins. Recent studies have successfully demonstrated the advantages of performing solid-state NMR experiments at very low and ultralow temperatures to enhance the sensitivity. However, the long spin-lattice relaxation time, T1, at very low temperatures is a major limitation. To overcome this difficulty, we demonstrate the use of a copper-chelated lipid for magic angle spinning solid-state NMR measurements on cytochrome-b5 reconstituted in multilamellar vesicles. Our results on multilamellar vesicles containing as small as 0.5mol% of a copper-chelated lipid can significantly shorten T1 of protons, which can be used to considerably reduce the data collection time or to enhance the signal-to-noise ratio. We also monitored the effect of slow cooling on the resolution and sensitivity of (13)C and (15)N signals from the protein and (13)C signals from lipids. PMID:24246881

  14. In vivo high-resolution magic angle spinning magnetic resonance spectroscopy of Drosophila melanogaster at 14.1 T shows trauma in aging and in innate immune-deficiency is linked to reduced insulin signaling

    PubMed Central

    RIGHI, VALERIA; APIDIANAKIS, YIORGOS; MINTZOPOULOS, DIONYSSIOS; ASTRAKAS, LOUKAS; RAHME, LAURENCE G.; TZIKA, A. ARIA

    2010-01-01

    In vivo magnetic resonance spectroscopy (MRS), a non-destructive biochemical tool for investigating live organisms, has yet to be used in the fruit fly Drosophila melanogaster, a useful model organism for investigating genetics and physiology. We developed and implemented a high-resolution magic-angle-spinning (HRMAS) MRS method to investigate live Drosophila at 14.1 T. We demonstrated, for the first time, the feasibility of using HRMAS MRS for molecular characterization of Drosophila with a conventional MR spectrometer equipped with an HRMAS probe. We showed that the metabolic HRMAS MRS profiles of injured, aged wild-type (wt) flies and of immune deficient (imd) flies were more similar to chico flies mutated at the chico gene in the insulin signaling pathway, which is analogous to insulin receptor substrate 1–4 (IRS1–4) in mammals and less to those of adipokinetic hormone receptor (akhr) mutant flies, which have an obese phenotype. We thus provide evidence for the hypothesis that trauma in aging and in innate immune-deficiency is linked to insulin signaling. This link may explain the mitochondrial dysfunction that accompanies insulin resistance and muscle wasting that occurs in trauma, aging and immune system deficiencies, leading to higher susceptibility to infection. Our approach advances the development of novel in vivo non-destructive research approaches in Drosophila, suggests biomarkers for investigation of biomedical paradigms, and thus may contribute to novel therapeutic development. PMID:20596596

  15. Stochastic molecular motions in the nematic, smectic-A, and solid phases of p,p{sup '}-di-n-heptyl-azoxybenzene as seen by quasielastic neutron scattering and {sup 13}C cross-polarization magic-angle-spinning NMR

    SciTech Connect

    ZajaPc, Wojciech; Urban, Stanislaw; Domenici, Valentina; Geppi, Marco; Veracini, Carlo Alberto; Telling, Mark T. F.; Gabrys, Barbara J.

    2006-05-15

    Molecular rotational dynamics in p,p{sup '}-di-n-heptyl-azoxybenzene was studied by means of quasielastic neutron scattering (QENS) and {sup 13}C cross-polarization magic-angle-spinning (CPMAS) NMR. Fast reorientation of the hydrogen nuclei was observed by QENS in the two liquid crystalline (LC) phases nematic and smectic A, as well as in the crystalline phase. The latter could not be restricted to the -CH{sub 3} rotations alone, and a clear indication was found of some other reorientation motions persisting in the crystal. Two Lorentz-type components convoluted with the resolution function gave an excellent fit to the QENS spectra in both LC phases. The narrow (slow) component was attributed to the reorientation of the whole molecule around the long axis. The corresponding characteristic time of {approx}130 ps agreed well with the values obtained in recent dielectric relaxation and {sup 2}H NMR studies. The full width at half maximum of the broader (fast) component shows a quadratic Q dependence (Q is the momentum transfer). Hence the corresponding motions could be described by a stretched exponential correlation function and were interpreted as various ''crankshaft-type'' motions within the alkyl tails. The {sup 13}C CPMAS experiments fully corroborated the QENS results, sometimes considered ambiguous in complex systems.

  16. Stochastic molecular motions in the nematic, smectic-A, and solid phases of p,p'-di-n-heptyl-azoxybenzene as seen by quasielastic neutron scattering and 13C cross-polarization magic-angle-spinning NMR.

    PubMed

    Zajac, Wojciech; Urban, Stanisław; Domenici, Valentina; Geppi, Marco; Veracini, Carlo Alberto; Telling, Mark T F; Gabryś, Barbara J

    2006-05-01

    Molecular rotational dynamics in p,p'-di-n-heptyl-azoxybenzene was studied by means of quasielastic neutron scattering (QENS) and 13C cross-polarization magic-angle-spinning (CPMAS) NMR. Fast reorientation of the hydrogen nuclei was observed by QENS in the two liquid crystalline (LC) phases nematic and smectic A, as well as in the crystalline phase. The latter could not be restricted to the -CH3 rotations alone, and a clear indication was found of some other reorientation motions persisting in the crystal. Two Lorentz-type components convoluted with the resolution function gave an excellent fit to the QENS spectra in both LC phases. The narrow (slow) component was attributed to the reorientation of the whole molecule around the long axis. The corresponding characteristic time of approximately 130 ps agreed well with the values obtained in recent dielectric relaxation and 2H NMR studies. The full width at half maximum of the broader (fast) component shows a quadratic Q dependence (Q is the momentum transfer). Hence the corresponding motions could be described by a stretched exponential correlation function and were interpreted as various "crankshaft-type" motions within the alkyl tails. The 13C CPMAS experiments fully corroborated the QENS results, sometimes considered ambiguous in complex systems. PMID:16802951

  17. {sup 13}C, {sup 1}H, {sup 6}Li magic-angle spinning nuclear magnetic resonance, electron paramagnetic resonance, and Fourier transform infrared study of intercalation electrodes based in ultrasoft carbons obtained below 3100 K

    SciTech Connect

    Alcantara, R.; Madrigal, F.J.F.; Lavela, P.; Tirado, J.L.; Mateos, J.M.J.; Stoyanova, R.; Zhecheva, E.

    1999-01-01

    The past decade has seen an important development of materials for high-performance energy storage systems. Particularly, the field of electrode materials for advanced lithium batteries has attracted the interest of numerous researchers. Petroleum coke samples of different origins and heat treated at different temperatures below 3100 K have been studied by spectroscopic and electrochemical procedures. According to {sup 13}C and {sup 1}H magic-angle spinning (MAS) nuclear magnetic resonance (NMR), infrared (IR), and electron paramagnetic resonance (EPR) data, aromatic compounds and surface OH groups are present in green coke samples. The preparation of CMB (combustible) sample from 1673 K leads to a low-temperature graphitization process, as shown by the occurrence of multiphase products containing both turbostatic and graphitized solid. This process is accompanied by the loss of aromatic compounds and surface hydroxyls. The optimization of the lithium intercalation electrodes based in the green coke materials was carried out by thermal treatment at 1023 K under dynamic vacuum conditions. Such pretreatment of the electrode material leads to marked enhancement of reversible capacities without the higher temperatures usually required for other soft carbon materials. Finally, the results of {sup 6}Li MAS NMR and EPR have been correlated with the experimental determination of lithium diffusion coefficients and surface properties. On the basis of these results, spin resonance spectroscopies are found to be a powerful tool to discern between the different petroleum coke samples to select the active electrode material with best performance.

  18. Shortening Spin-lattice Relaxation Using a Copper-Chelated lipid at Low-Temperatures – A Magic Angle Spinning Solid-State NMR Study on a Membrane-Bound Protein

    PubMed Central

    Yamamoto, Kazutoshi; Caporini, Marc; Im, Sangchoul; Waskell, Lucy; Ramamoorthy, Ayyalusamy

    2013-01-01

    Inherent low sensitivity of NMR spectroscopy has been a major disadvantage, especially to study biomolecules like membrane proteins. Recent studies have successfully demonstrated the advantages of performing solid-state NMR experiments at very low and ultralow temperatures to enhance the sensitivity. However, the long spin-lattice relaxation time, T1, at very low temperatures is a major limitation. To overcome this difficulty, we demonstrate the use of a copper-chelated lipid for magic angle spinning solid-state NMR measurements on cytochrome-b5 reconstituted in multilamellar vesicles. Our results on multilamellar vesicles containing as small as 0.5 mole % of a copper-chelated lipid can significantly shorten T1 of protons, which can be used to considerably reduce the data collection time or to enhance the signal-to-noise ratio. We also monitored the effect of slow cooling on the resolution and sensitivity of 13C and 15N signals from the protein and 13C signals from lipids. PMID:24246881

  19. Identification of BCL11B as a regulator of adipogenesis

    PubMed Central

    Inoue, Jun; Ihara, Yusuke; Tsukamoto, Daisuke; Yasumoto, Keisuke; Hashidume, Tsutomu; Kamimura, Kenya; Nakai, Yuji; Hirano, Shigeki; Shimizu, Makoto; Kominami, Ryo; Sato, Ryuichiro

    2016-01-01

    The differentiation of preadipocytes into adipocytes is controlled by several transcription factors, including peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), which are known as master regulators of adipogenesis. BCL11B is a zinc finger-type transcription factor that regulates the development of the skin and central nervous and immune systems. Here, we found that BCL11B was expressed in the white adipose tissue (WAT), particularly the subcutaneous WAT and that BCL11B−/− mice had a reduced amount of subcutaneous WAT. During adipogenesis, BCL11B expression transiently increased in 3T3-L1 preadipocytes and mouse embryonic fibroblasts (MEFs). The ability for adipogenesis was reduced in BCL11B knockdown 3T3-L1 cells and BCL11B−/− MEFs, whereas the ability for osteoblastogenesis was unaffected in BCL11B−/− MEFs. Luciferase reporter gene assays revealed that BCL11B stimulated C/EBPβ activity. Furthermore, the expression of downstream genes of the Wnt/β-catenin signaling pathway was not suppressed in BCL11B−/− MEFs during adipogenesis. Thus, this study identifies BCL11B as a novel regulator of adipogenesis, which works, at least in part, by stimulating C/EBPβ activity and suppressing the Wnt/β-catenin signaling pathway. PMID:27586877

  20. The Magic of Balanced Groups: Educational Applications of Magic Squares

    ERIC Educational Resources Information Center

    Bosse, Michael J.; Nandakumar, N. R.; Ore, Melanie L.

    2007-01-01

    This paper provides students with many interesting observations regarding the nature of magic squares, magic rectangles, and quasi-magic squares and provides tools for teachers to group students into ability-balanced cooperative learning groups.

  1. A 23Na magic angle spinning nuclear magnetic resonance, XANES, and high-temperature X-ray diffraction study of NaUO3, Na4UO5, and Na2U2O7.

    PubMed

    Smith, A L; Raison, P E; Martel, L; Charpentier, T; Farnan, I; Prieur, D; Hennig, C; Scheinost, A C; Konings, R J M; Cheetham, A K

    2014-01-01

    The valence state of uranium has been confirmed for the three sodium uranates NaU(V)O3/[Rn](5f(1)), Na4U(VI)O5/[Rn](5f(0)), and Na2U(VI)2O7/[Rn](5f(0)), using X-ray absorption near-edge structure (XANES) spectroscopy. Solid-state (23)Na magic angle spinning nuclear magnetic resonance (MAS NMR) measurements have been performed for the first time, yielding chemical shifts at -29.1 (NaUO3), 15.1 (Na4UO5), and -14.1 and -19 ppm (Na1 8-fold coordinated and Na2 7-fold coordinated in Na2U2O7), respectively. The [Rn]5f(1) electronic structure of uranium in NaUO3 causes a paramagnetic shift in comparison to Na4UO5 and Na2U2O7, where the electronic structure is [Rn]5f(0). A (23)Na multi quantum magic angle spinning (MQMAS) study on Na2U2O7 has confirmed a monoclinic rather than rhombohedral structure with evidence for two distinct Na sites. DFT calculations of the NMR parameters on the nonmagnetic compounds Na4UO5 and Na2U2O7 have permitted the differentiation between the two Na sites of the Na2U2O7 structure. The linear thermal expansion coefficients of all three compounds have been determined using high-temperature X-ray diffraction: αa = 22.7 × 10(-6) K(-1), αb = 12.9 × 10(-6) K(-1), αc = 16.2 × 10(-6) K(-1), and αvol = 52.8 × 10(-6) K(-1) for NaUO3 in the range 298-1273 K; αa = 37.1 × 10(-6) K(-1), αc = 6.2 × 10(-6) K(-1), and αvol = 81.8 × 10(-6) K(-1) for Na4UO5 in the range 298-1073 K; αa = 6.7 × 10(-6) K(-1), αb = 14.4 × 10(-6) K(-1), αc = 26.8 × 10(-6) K(-1), αβ = -7.8 × 10(-6) K(-1), and αvol = -217.6 × 10(-6) K(-1) for Na2U2O7 in the range 298-573 K. The α to β phase transition reported for the last compound above about 600 K was not observed in the present studies, either by high-temperature X-ray diffraction or by differential scanning calorimetry. PMID:24350659

  2. 31P magic angle spinning NMR study of flux-grown rare-earth element orthophosphate (monazite/xenotime) solid solutions: evidence of random cation distribution from paramagnetically shifted NMR resonances.

    PubMed

    Palke, Aaron C; Stebbins, Jonathan F; Boatner, Lynn A

    2013-11-01

    We present (31)P magic angle spinning nuclear magnetic resonance spectra of flux-grown solid solutions of La(1-x)Ce(x)PO4 (x between 0.027 and 0.32) having the monoclinic monazite structure, and of Y(1-x)M(x)PO4 (M = V(n+), Ce(3+), Nd(3+), x between 0.001 and 0.014) having the tetragonal zircon structure. Paramagnetically shifted NMR resonances are observed in all samples due to the presence of paramagnetic V(n+), Ce(3+), and Nd(3+) in the diamagnetic LaPO4 or YPO4. As a first-order observation, the number and relative intensities of these peaks are related to the symmetry and structure of the diamagnetic host phase. The presence of paramagnetic shifts allows for increased resolution between NMR resonances for distinct atomic species which leads to the observation of low intensity peaks related to PO4 species having more than one paramagnetic neighbor two or four atomic bonds away. Through careful analysis of peak areas and comparison with predictions for simple models, it was determined that solid solutions in the systems examined here are characterized by complete disorder (random distribution) of diamagnetic La(3+) or Y(3+) with the paramagnetic substitutional species Ce(3+) and Nd(3+). The increased resolution given by the paramagnetic interactions also leads to the observation of splitting of specific resonances in the (31)P NMR spectra that may be caused by local, small-scale distortions from the substitution of ions having dissimilar ionic radii. PMID:24131129

  3. The Role of High-Resolution Magic Angle Spinning 1H Nuclear Magnetic Resonance Spectroscopy for Predicting the Invasive Component in Patients with Ductal Carcinoma In Situ Diagnosed on Preoperative Biopsy.

    PubMed

    Chae, Eun Young; Shin, Hee Jung; Kim, Suhkmann; Baek, Hyeon-Man; Yoon, Dahye; Kim, Siwon; Shim, Ye Eun; Kim, Hak Hee; Cha, Joo Hee; Choi, Woo Jung; Lee, Jeong Hyun; Shin, Ji Hoon; Lee, Hee Jin; Gong, Gyungyub

    2016-01-01

    The purpose of this study was to evaluate the role of high-resolution magic angle spinning (HR-MAS) 1H nuclear magnetic resonance (NMR) spectroscopy in patients with ductal carcinoma in situ (DCIS) diagnosed on preoperative biopsy. We investigated whether the metabolic profiling of tissue samples using HR-MAS 1H NMR spectroscopy could be used to distinguish between DCIS lesions with or without an invasive component. Our institutional review board approved this combined retrospective and prospective study. Tissue samples were collected from 30 patients with pure DCIS and from 30 with DCIS accompanying invasive carcinoma. All patients were diagnosed with DCIS by preoperative core-needle biopsy and underwent surgical resection. The metabolic profiling of tissue samples was performed by HR-MAS 1H NMR spectroscopy. All observable metabolite signals were identified and quantified in all tissue samples. Metabolite intensity normalized by total spectral intensities was compared according to the tumor type using the Mann-Whitney test. Multivariate analysis was performed with orthogonal projections to latent structure-discriminant analysis (OPLS-DA). By univariate analysis, the metabolite concentrations of choline-containing compounds obtained with HR-MAS 1H NMR spectroscopy did not differ significantly between the pure DCIS and DCIS accompanying invasive carcinoma groups. However, the GPC/PC ratio was higher in the pure DCIS group than in the DCIS accompanying invasive carcinoma group (p = 0.004, Bonferroni-corrected p = 0.064), as well as the concentration of myo-inositol and succinate. By multivariate analysis, the OPLS-DA models built with HR-MAS MR metabolic profiles could clearly discriminate between pure DCIS and DCIS accompanying invasive carcinoma. Our preliminary results suggest that HR-MAS MR metabolomics on breast tissue may be able to distinguish between DCIS lesions with or without an invasive component. PMID:27560937

  4. Nano-Mole Scale Side-Chain Signal Assignment by 1H-Detected Protein Solid-State NMR by Ultra-Fast Magic-Angle Spinning and Stereo-Array Isotope Labeling

    PubMed Central

    Nishiyama, Yusuke; Endo, Yuki; Nemoto, Takahiro; Yamauchi, Kazuo; Asakura, Tetsuo; Takeda, Mitsuhiro; Terauchi, Tsutomu; Kainosho, Masatsune; Ishii, Yoshitaka

    2015-01-01

    We present a general approach in 1H-detected 13C solid-state NMR (SSNMR) for side-chain signal assignments of 10-50 nmol quantities of proteins using a combination of a high magnetic field, ultra-fast magic-angle spinning (MAS) at ~80 kHz, and stereo-array-isotope-labeled (SAIL) proteins [Kainosho M. et al., Nature 440, 52–57, 2006]. First, we demonstrate that 1H indirect detection improves the sensitivity and resolution of 13C SSNMR of SAIL proteins for side-chain assignments in the ultra-fast MAS condition. 1H-detected SSNMR was performed for micro-crystalline ubiquitin (~55 nmol or ~0.5mg) that was SAIL-labeled at seven isoleucine (Ile) residues. Sensitivity was dramatically improved by 1H-detected 2D 1H/13C SSNMR by factors of 5.4-9.7 and 2.1-5.0, respectively, over 13C-detected 2D 1H/13C SSNMR and 1D 13C CPMAS, demonstrating that 2D 1H-detected SSNMR offers not only additional resolution but also sensitivity advantage over 1D 13C detection for the first time. High 1H resolution for the SAIL-labeled side-chain residues offered reasonable resolution even in the 2D data. A 1H-detected 3D 13C/13C/1H experiment on SAIL-ubiquitin provided nearly complete 1H and 13C assignments for seven Ile residues only within ~2.5 h. The results demonstrate the feasibility of side-chain signal assignment in this approach for as little as 10 nmol of a protein sample within ~3 days. The approach is likely applicable to a variety of proteins of biological interest without any requirements of highly efficient protein expression systems. PMID:25856081

  5. Nano-mole scale side-chain signal assignment by 1H-detected protein solid-state NMR by ultra-fast magic-angle spinning and stereo-array isotope labeling.

    PubMed

    Wang, Songlin; Parthasarathy, Sudhakar; Nishiyama, Yusuke; Endo, Yuki; Nemoto, Takahiro; Yamauchi, Kazuo; Asakura, Tetsuo; Takeda, Mitsuhiro; Terauchi, Tsutomu; Kainosho, Masatsune; Ishii, Yoshitaka

    2015-01-01

    We present a general approach in 1H-detected 13C solid-state NMR (SSNMR) for side-chain signal assignments of 10-50 nmol quantities of proteins using a combination of a high magnetic field, ultra-fast magic-angle spinning (MAS) at ~80 kHz, and stereo-array-isotope-labeled (SAIL) proteins [Kainosho M. et al., Nature 440, 52-57, 2006]. First, we demonstrate that 1H indirect detection improves the sensitivity and resolution of 13C SSNMR of SAIL proteins for side-chain assignments in the ultra-fast MAS condition. 1H-detected SSNMR was performed for micro-crystalline ubiquitin (~55 nmol or ~0.5mg) that was SAIL-labeled at seven isoleucine (Ile) residues. Sensitivity was dramatically improved by 1H-detected 2D 1H/13C SSNMR by factors of 5.4-9.7 and 2.1-5.0, respectively, over 13C-detected 2D 1H/13C SSNMR and 1D 13C CPMAS, demonstrating that 2D 1H-detected SSNMR offers not only additional resolution but also sensitivity advantage over 1D 13C detection for the first time. High 1H resolution for the SAIL-labeled side-chain residues offered reasonable resolution even in the 2D data. A 1H-detected 3D 13C/13C/1H experiment on SAIL-ubiquitin provided nearly complete 1H and 13C assignments for seven Ile residues only within ~2.5 h. The results demonstrate the feasibility of side-chain signal assignment in this approach for as little as 10 nmol of a protein sample within ~3 days. The approach is likely applicable to a variety of proteins of biological interest without any requirements of highly efficient protein expression systems. PMID:25856081

  6. Study of lignification by noninvasive techniques in growing maize internodes. An investigation by Fourier transform infrared cross-polarization-magic angle spinning 13C-nuclear magnetic resonance spectroscopy and immunocytochemical transmission electron microscopy.

    PubMed

    Joseleau, J P; Ruel, K

    1997-07-01

    Noninvasive techniques were used for the study in situ of lignification in the maturing cell walls of the maize (Zea mays L.) stem. Within the longitudinal axis of a developing internode all of the stages of lignification can be found. The synthesis of the three types of lignins, p-hydroxyphenylpropane (H), guaiacyl (G), and syringyl (S), was investigated in situ by cross-polarization-magic angle spinning 13C-solid-state nuclear magnetic resonance, Fourier transform infrared spectroscopy, and immunocytochemical electron microscopy. The first lignin appearing in the parenchyma is of the G-type preceeding the incorporation of S nuclei in the later stages. However, in vascular bundles, typical absorption bands of S nuclei are visible in the Fourier transform infrared spectra at the earliest stage of lignification. Immunocytochemical determination of the three types of lignin in transmission electron microscopy was possible thanks to the use of antisera prepared against synthetic H, G, and the mixed GS dehydrogenative polymers (K. Ruel, O. Faix, J.P. Joseleau [1994] J Trace Microprobe Tech 12: 247-265). The specificity of the immunological probes demonstrated that there are differences in the relative temporal synthesis of the H, G, and GS lignins in the different tissues undergoing lignification. Considering the intermonomeric linkages predominating in the antigens used for the preparation of the immunological probes, the relative intensities of the labeling obtained provided, for the first time to our knowledge, information about the macromolecular nature of lignins (condensed versus noncondensed) in relation to their ultrastructural localization and development stage. PMID:9232887

  7. The Role of High-Resolution Magic Angle Spinning 1H Nuclear Magnetic Resonance Spectroscopy for Predicting the Invasive Component in Patients with Ductal Carcinoma In Situ Diagnosed on Preoperative Biopsy

    PubMed Central

    Chae, Eun Young; Kim, Suhkmann; Baek, Hyeon-Man; Yoon, Dahye; Kim, Siwon; Shim, Ye Eun; Kim, Hak Hee; Cha, Joo Hee; Choi, Woo Jung; Lee, Jeong Hyun; Shin, Ji Hoon; Lee, Hee Jin; Gong, Gyungyub

    2016-01-01

    The purpose of this study was to evaluate the role of high-resolution magic angle spinning (HR-MAS) 1H nuclear magnetic resonance (NMR) spectroscopy in patients with ductal carcinoma in situ (DCIS) diagnosed on preoperative biopsy. We investigated whether the metabolic profiling of tissue samples using HR-MAS 1H NMR spectroscopy could be used to distinguish between DCIS lesions with or without an invasive component. Our institutional review board approved this combined retrospective and prospective study. Tissue samples were collected from 30 patients with pure DCIS and from 30 with DCIS accompanying invasive carcinoma. All patients were diagnosed with DCIS by preoperative core-needle biopsy and underwent surgical resection. The metabolic profiling of tissue samples was performed by HR-MAS 1H NMR spectroscopy. All observable metabolite signals were identified and quantified in all tissue samples. Metabolite intensity normalized by total spectral intensities was compared according to the tumor type using the Mann-Whitney test. Multivariate analysis was performed with orthogonal projections to latent structure-discriminant analysis (OPLS-DA). By univariate analysis, the metabolite concentrations of choline-containing compounds obtained with HR-MAS 1H NMR spectroscopy did not differ significantly between the pure DCIS and DCIS accompanying invasive carcinoma groups. However, the GPC/PC ratio was higher in the pure DCIS group than in the DCIS accompanying invasive carcinoma group (p = 0.004, Bonferroni-corrected p = 0.064), as well as the concentration of myo-inositol and succinate. By multivariate analysis, the OPLS-DA models built with HR-MAS MR metabolic profiles could clearly discriminate between pure DCIS and DCIS accompanying invasive carcinoma. Our preliminary results suggest that HR-MAS MR metabolomics on breast tissue may be able to distinguish between DCIS lesions with or without an invasive component. PMID:27560937

  8. Formation and Decay of {sup 24}Mg in the {sup 13}N+{sup 11}B Collision

    SciTech Connect

    P. Figuera; F. Amorini; W. Bradfield-Smith; M. Cabibbo; G. Cardella; T. Davinson; A. DiPietro; W. Galster; P. Leleux; A. Musumarra; A. Ninane; M. Papa; G. Pappalardo; F. Rizzo; A.C. Shotter; C. Sukosd; S. Tudisco; P.J. Woods

    1999-12-31

    Different aspects of the formation and decay of {sup 24}Mg in the collision {sup 13}N+{sup 11}B have been studied using a large solid angle and highly segmented Silicon strip detector. Results concerning the fusion cross section, the 6 {alpha} decay of {sup 24}Mg and the GDR gamma ray emission are discussed.

  9. Formation and decay of {sup 24}Mg in the {sup 13}N+{sup 11}B collision

    SciTech Connect

    Figuera, P.; Amorini, F.; Cabibbo, M.; Papalardo, G.; Rizzo, F.; Tudisco, S.; Bradfield-Smith, W.; Davinson, T.; Di Pietro, A.; Shotter, A. C.; Woods, P. J.; Cardella, G.; Papa, M.; Galster, W.; Leleux, P.; Musumarra, A.; Ninane, A.; Sukosd, C.

    1999-11-16

    Different aspects of the formation and decay of {sup 24}Mg in the collision {sup 13}N+{sup 11}B have been studied using a large solid angle and highly segmented Silicon strip detector. Results concerning the fusion cross section, the 6 {alpha} decay of {sup 24}Mg and the GDR gamma ray emission are discussed.

  10. Determination of methyl 13C-15N dipolar couplings in peptides and proteins by three-dimensional and four-dimensional magic-angle spinning solid-state NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Helmus, Jonathan J.; Nadaud, Philippe S.; Höfer, Nicole; Jaroniec, Christopher P.

    2008-02-01

    We describe three- and four-dimensional semiconstant-time transferred echo double resonance (SCT-TEDOR) magic-angle spinning solid-state nuclear magnetic resonance (NMR) experiments for the simultaneous measurement of multiple long-range N15-Cmethyl13 dipolar couplings in uniformly C13, N15-enriched peptides and proteins with high resolution and sensitivity. The methods take advantage of C13 spin topologies characteristic of the side-chain methyl groups in amino acids alanine, isoleucine, leucine, methionine, threonine, and valine to encode up to three distinct frequencies (N15-Cmethyl13 dipolar coupling, N15 chemical shift, and Cmethyl13 chemical shift) within a single SCT evolution period of initial duration ˜1/JCC1 (where JCC1≈35Hz, is the one-bond Cmethyl13-C13 J-coupling) while concurrently suppressing the modulation of NMR coherences due to C13-C13 and N15-C13 J-couplings and transverse relaxation. The SCT-TEDOR schemes offer several important advantages over previous methods of this type. First, significant (approximately twofold to threefold) gains in experimental sensitivity can be realized for weak N15-Cmethyl13 dipolar couplings (corresponding to structurally interesting, ˜3.5Å or longer, distances) and typical Cmethyl13 transverse relaxation rates. Second, the entire SCT evolution period can be used for Cmethyl13 and/or N15 frequency encoding, leading to increased spectral resolution with minimal additional coherence decay. Third, the experiments are inherently "methyl selective," which results in simplified NMR spectra and obviates the use of frequency-selective pulses or other spectral filtering techniques. Finally, the N15-C13 cross-peak buildup trajectories are purely dipolar in nature (i.e., not influenced by J-couplings or relaxation), which enables the straightforward extraction of N15-Cmethyl13 distances using an analytical model. The SCT-TEDOR experiments are demonstrated on a uniformly C13, N15-labeled peptide, N-acetyl-valine, and a 56

  11. Structure of amantadine-bound M2 transmembrane peptide of influenza A in lipid bilayers from magic-angle-spinning solid-state NMR: the role of Ser31 in amantadine binding.

    PubMed

    Cady, Sarah D; Mishanina, Tatiana V; Hong, Mei

    2009-01-30

    The M2 proton channel of influenza A is the target of the antiviral drugs amantadine and rimantadine, whose effectiveness has been abolished by a single-site mutation of Ser31 to Asn in the transmembrane domain of the protein. Recent high-resolution structures of the M2 transmembrane domain obtained from detergent-solubilized protein in solution and crystal environments gave conflicting drug binding sites. We present magic-angle-spinning solid-state NMR results of Ser31 and a number of other residues in the M2 transmembrane peptide (M2TMP) bound to lipid bilayers. Comparison of the spectra of the membrane-bound apo and complexed M2TMP indicates that Ser31 is the site of the largest chemical shift perturbation by amantadine. The chemical shift constraints lead to a monomer structure with a small kink of the helical axis at Gly34. A tetramer model is then constructed using the helix tilt angle and several interhelical distances previously measured on unoriented bilayer samples. This tetramer model differs from the solution and crystal structures in terms of the openness of the N-terminus of the channel, the constriction at Ser31, and the side-chain conformations of Trp41, a residue important for channel gating. Moreover, the tetramer model suggests that Ser31 may interact with amantadine amine via hydrogen bonding. While the apo and drug-bound M2TMP have similar average structures, the complexed peptide has much narrower linewidths at physiological temperature, indicating drug-induced changes of the protein dynamics in the membrane. Further, at low temperature, several residues show narrower lines in the complexed peptide than the apo peptide, indicating that amantadine binding reduces the conformational heterogeneity of specific residues. The differences of the current solid-state NMR structure of the bilayer-bound M2TMP from the detergent-based M2 structures suggest that the M2 conformation is sensitive to the environment, and care must be taken when interpreting

  12. Discovery and in Vivo Evaluation of Potent Dual CYP11B2 (Aldosterone Synthase) and CYP11B1 Inhibitors.

    PubMed

    Meredith, Erik L; Ksander, Gary; Monovich, Lauren G; Papillon, Julien P N; Liu, Qian; Miranda, Karl; Morris, Patrick; Rao, Chang; Burgis, Robin; Capparelli, Michael; Hu, Qi-Ying; Singh, Alok; Rigel, Dean F; Jeng, Arco Y; Beil, Michael; Fu, Fumin; Hu, Chii-Whei; LaSala, Daniel

    2013-12-12

    Aldosterone is a key signaling component of the renin-angiotensin-aldosterone system and as such has been shown to contribute to cardiovascular pathology such as hypertension and heart failure. Aldosterone synthase (CYP11B2) is responsible for the final three steps of aldosterone synthesis and thus is a viable therapeutic target. A series of imidazole derived inhibitors, including clinical candidate 7n, have been identified through design and structure-activity relationship studies both in vitro and in vivo. Compound 7n was also found to be a potent inhibitor of 11β-hydroxylase (CYP11B1), which is responsible for cortisol production. Inhibition of CYP11B1 is being evaluated in the clinic for potential treatment of hypercortisol diseases such as Cushing's syndrome. PMID:24900631

  13. The "Magic" Flask.

    ERIC Educational Resources Information Center

    Battino, Rubin; And Others

    1995-01-01

    Presents demonstrations that use a "magic" flask to teach elementary concepts such as the color changes of various indicators and using the scientific method to predict the sequence of color changes. Catches students' attention by using an unexpected trick or element of magic. (JRH)

  14. Chinese "Magic" Mirrors.

    ERIC Educational Resources Information Center

    Swinson, Derek B.

    1992-01-01

    Chinese "magic" mirrors are made from bronze with the front side a mirror and the reverse side a molded image. When light is reflected from the mirror,the image on the reverse side appears. Discusses reflections of conventional mirrors, possible explanations for the magic mirror phenomenon, and applications of the phenomenon to semiconductor…

  15. The "Magic" String

    ERIC Educational Resources Information Center

    Hoover, Todd F.

    2010-01-01

    The "Magic" String is a discrepant event that includes a canister with what appears to be the end of two strings protruding from opposite sides of it. Due to the way the strings are attached inside the canister, it appears as if the strings can magically switch the way they are connected. When one string end is pulled, the observer's expectation…

  16. Operation Magic Tricks.

    ERIC Educational Resources Information Center

    Edwards, Ronald

    This resource book contains 18 magic number tricks that spark the interest and imagination of students as they are led through a variety of mathematical computations and discoveries. Following each activity, students are asked to write about their discoveries and create their own magic tricks. A matrix of skills for all the activities and lists of…

  17. Investigation of the Curvature Induction and Membrane Localization of the Influenza Virus M2 Protein Using Static and Off-Magic-Angle Spinning Solid-State NMR of Oriented Bicelles

    PubMed Central

    Wang, Tuo; Hong, Mei

    2015-01-01

    A wide variety of membrane proteins induce membrane curvature for function, thus it is important to develop new methods to simultaneously determine membrane curvature and protein binding sites in membranes with multiple curvatures. We introduce solid-state NMR methods based on magnetically oriented bicelles and off-magic-angle spinning (OMAS) to measure membrane curvature and the binding site of proteins in mixed-curvature membranes. We demonstrate these methods on the influenza virus M2 protein, which not only acts as a proton channel but also mediates virus assembly and membrane scission. An M2 peptide encompassing the transmembrane (TM) domain and an amphipathic helix, M2(21-61), was studied and compared with the TM peptide (M2TM). Static 31P NMR spectra of magnetically oriented DMPC/DHPC bicelles exhibit a temperature-independent isotropic chemical shift in the presence of M2(21-61) but not M2TM, indicating that the amphipathic helix confers the peptide with the ability to generate a high-curvature phase. 2D 31P spectra indicate that this high-curvature phase is associated with the DHPC bicelle edges, suggestive of the structure of budding viruses from the host cell. 31P- and 13C-detected 1H relaxation times of the lipids indicate that the majority of M2(21-61) is bound to the high-curvature phase. Using OMAS experiments, we resolved the 31P signals of lipids with identical headgroups based on their distinct chemical shift anisotropies. Based on this resolution, 2D 1H-31P correlation spectra show that the amide protons in M2(21-61) correlate with the DMPC but not the DHPC 31P signal of the bicelle, indicating that a small percentage of M2(21-61) partitions into the planar region of the bicelles. These results show that the M2 amphipathic helix induces high membrane curvature and localizes the protein to this phase, in excellent agreement with the membrane-scission function of the protein. These bicelle-based relaxation and OMAS solid-state NMR techniques are

  18. Metabolomics of Breast Cancer Using High-Resolution Magic Angle Spinning Magnetic Resonance Spectroscopy: Correlations with 18F-FDG Positron Emission Tomography-Computed Tomography, Dynamic Contrast-Enhanced and Diffusion-Weighted Imaging MRI

    PubMed Central

    Yoon, Haesung; Yoon, Dahye; Yun, Mijin; Choi, Ji Soo; Park, Vivian Youngjean; Kim, Eun-Kyung; Jeong, Joon; Koo, Ja Seung; Yoon, Jung Hyun; Moon, Hee Jung; Kim, Suhkmann; Kim, Min Jung

    2016-01-01

    Purpose Our goal in this study was to find correlations between breast cancer metabolites and conventional quantitative imaging parameters using high-resolution magic angle spinning (HR-MAS) magnetic resonance spectroscopy (MRS) and to find breast cancer subgroups that show high correlations between metabolites and imaging parameters. Materials and methods Between August 2010 and December 2013, we included 53 female patients (mean age 49.6 years; age range 32–75 years) with a total of 53 breast lesions assessed by the Breast Imaging Reporting and Data System. They were enrolled under the following criteria: breast lesions larger than 1 cm in diameter which 1) were suspicious for malignancy on mammography or ultrasound (US), 2) were pathologically confirmed to be breast cancer with US-guided core-needle biopsy (CNB) 3) underwent 3 Tesla MRI with dynamic contrast-enhanced (DCE) and diffusion-weighted imaging (DWI) and positron emission tomography-computed tomography (PET-CT), and 4) had an attainable immunohistochemistry profile from CNB. We acquired spectral data by HR-MAS MRS with CNB specimens and expressed the data as relative metabolite concentrations. We compared the metabolites with the signal enhancement ratio (SER), maximum standardized FDG uptake value (SUV max), apparent diffusion coefficient (ADC), and histopathologic prognostic factors for correlation. We calculated Spearman correlations and performed a partial least squares-discriminant analysis (PLS-DA) to further classify patient groups into subgroups to find correlation differences between HR-MAS spectroscopic values and conventional imaging parameters. Results In a multivariate analysis, the PLS-DA models built with HR-MAS MRS metabolic profiles showed visible discrimination between high and low SER, SUV, and ADC. In luminal subtype breast cancer, compared to all cases, high SER, ADV, and SUV were more closely clustered by visual assessment. Multiple metabolites were correlated with SER and SUV in

  19. 1H-13C/1H-15N Heteronuclear Dipolar Recoupling by R-Symmetry Sequences Under Fast Magic Angle Spinning for Dynamics Analysis of Biological and Organic Solids

    PubMed Central

    Hou, Guangjin; Byeon, In-Ja L.; Ahn, Jinwoo; Gronenborn, Angela M.; Polenova, Tatyana

    2011-01-01

    Fast magic angle spinning (MAS) NMR spectroscopy is becoming increasingly important in structural and dynamics studies of biological systems and inorganic materials. Superior spectral resolution due to the efficient averaging of the dipolar couplings can be attained at MAS frequencies of 40 kHz and higher with appropriate decoupling techniques, while proton detection gives rise to significant sensitivity gains, therefore making fast MAS conditions advantageous across the board compared with the conventional slow- and moderate-MAS approaches. At the same time, many of the dipolar recoupling approaches that currently constitute the basis for structural and dynamics studies of solid materials and that are designed for MAS frequencies of 20 kHz and below, fail above 30 kHz. In this report, we present an approach for 1H-13C/1H-15N heteronuclear dipolar recoupling under fast MAS conditions using R-type symmetry sequences, which is suitable even for fully protonated systems. A series of rotor-synchronized R-type symmetry pulse schemes are explored for the determination of structure and dynamics in biological and organic systems. The investigations of the performance of the various RNnv-symmetry sequences at the MAS frequency of 40 kHz experimentally and by numerical simulations on [U-13C,15N]-alanine and [U-13C,15N]-N-acetyl-valine, revealed excellent performance for sequences with high symmetry number ratio (N/2n > 2.5). Further applications of this approach are presented for two proteins, sparsely 13C/uniformly 15N enriched CAP-Gly domain of dynactin and U-13C,15N-Tyr enriched C-terminal domain of HIV-1 CA protein. 2D and 3D R1632-based DIPSHIFT experiments carried out at the MAS frequency of 40 kHz, yielded site-specific 1H-13C/1H-15N heteronuclear dipolar coupling constants for CAP-Gly and CTD CA, reporting on the dynamic behavior of these proteins on time scales of nano- to microseconds. The R-symmetry based dipolar recoupling under fast MAS is expected to find

  20. Discovering the Magic of Magic Squares

    ERIC Educational Resources Information Center

    Semanisinova, Ingrid; Trenkler, Marian

    2007-01-01

    The purpose of this article is to present a collection of problems that allow students to investigate magic squares and Latin squares, formulate their own conjectures about these mathematical objects, look for arguments supporting or disproving their conjectures, and finally establish and prove mathematical assertions. Each problem is completed…

  1. Spinning angle optical calibration apparatus

    DOEpatents

    Beer, Stephen K.; Pratt, II, Harold R.

    1991-01-01

    An optical calibration apparatus is provided for calibrating and reproducing spinning angles in cross-polarization, nuclear magnetic resonance spectroscopy. An illuminated magnifying apparatus enables optical setting an accurate reproducing of spinning "magic angles" in cross-polarization, nuclear magnetic resonance spectroscopy experiments. A reference mark scribed on an edge of a spinning angle test sample holder is illuminated by a light source and viewed through a magnifying scope. When the "magic angle" of a sample material used as a standard is attained by varying the angular position of the sample holder, the coordinate position of the reference mark relative to a graduation or graduations on a reticle in the magnifying scope is noted. Thereafter, the spinning "magic angle" of a test material having similar nuclear properties to the standard is attained by returning the sample holder back to the originally noted coordinate position.

  2. About Magic Rectangles

    ERIC Educational Resources Information Center

    Hakopian, Yuri R.; Eloyan, Ani N.; Khachatryan, David E.

    2006-01-01

    This paper introduces a class of matrices, the rows and columns of which add up to identical constants (generally speaking, different for rows and columns). Some properties of these matrices, which will be called "magic rectangles" are discussed.

  3. Let's Make Magic.

    ERIC Educational Resources Information Center

    Bang-Jensen, Valerie

    1986-01-01

    A learning experience designed to expand primary students' knowledge of what is and is not magic is described. Included are activities involving language arts, math, art, class discussion, and motor skills. (MT)

  4. Science, Magic, and Culture

    ERIC Educational Resources Information Center

    Wangler, David G.

    1974-01-01

    The differences which appear when a heavily scientific culture comes in contact with a culture whose basic orientation toward nature and man is of a religious, magical character are briefly investigated. (NQ)

  5. Exoplanet HAT-P-11b Secondary Transit Observations

    NASA Technical Reports Server (NTRS)

    Barry, Richard K., Jr.

    2010-01-01

    We have conducted secondary eclipse observations of exoplanet HAT--11b, recently discovered by proposal G. Bakos and his colleagues. HAT-P-11b is the smallest transiting extrasolar planet yet found and one of only two known exo-Neptunes. We have observed the system at 3.6 microns for a period of 22 hours centered on the anticipated secondary eclipse time, to detect the eclipse and determine its phase. Once the secondary eclipse is located through analysis of the data, we will make a more focused series of observations in both the 3.6 and 4.5 micron bands to fully characterize it. HAT-P-1lb has a period of 4.8878 days, radius of 0.422 RJ, mass of 0.081 MJ and semi major axis 0.053 AU. Measurements of the secondary eclipse will clarify two key issues; 1) the planetary brightness temperature and the nature of its atmosphere, and 2) the eccentricity of its orbit, with implications for its dynamical evolution. A precise determination of the orbit phase for the secondary eclipse will also be of great utility for Kepler observations of this system at visible wavelengths.

  6. Unexpected doubly-magic nucleus.

    SciTech Connect

    Janssens, R. V. F.; Physics

    2009-01-01

    Nuclei with a 'magic' number of both protons and neutrons, dubbed doubly magic, are particularly stable. The oxygen isotope {sup 24}O has been found to be one such nucleus - yet it lies just at the limit of stability.

  7. Down regulation of BCL11B expression inhibits proliferation and induces apoptosis in malignant T cells by BCL11B-935-siRNA.

    PubMed

    Huang, Xin; Chen, Si; Shen, Qi; Chen, Shaohua; Yang, Lijian; Grabarczyk, Piotr; Przybylski, Grzegorz K; Schmidt, Christian A; Li, Yangqiu

    2011-07-01

    To screen the highly efficient and specific B-cell chronic lymphocytic leukemia/lymphoma 11B (BCL11B) small interfering RNA (siRNA) which are able to downregulate the BCL11B gene expression in human T-cell acute lymphoblastic leukemia, thereby inhibiting the leukemic T-cell proliferation and inducing apoptosis, four BCL11B-siRNAs and the scrambled non-silencing siRNA control (sc) were designed and obtained by chemosynthesis. After nucleofection, BCL11B expression in the mRNA and the protein levels were measured by qRT-PCR and immunoblotting, respectively. The biological consequences based on the highly efficient and specific BCL11B-siRNA were demonstrated by CCK-8 kit, morphological changes (Hoechst 33258 staining), high-resolution imaging, and flow cytometry. Reduction in the BCL11B mRNA level was observed at 24 or 48 hours in molt-4 T cells with BCL11B-935-siRNA, BCL11B-434-siRNA, or BCL11B-748-siRNA, respectively. BCL11B protein expression levels were reduced by 34·77% and 41·73% in the BCL11B-935-siRNA- and BCL11B-434-siRNA-treated cells, compared with the control level at 72 hours. In comparison with BCL11B-434-siRNA treatment group, the Molt-4 cells transfected with the BCL11B-935-siRNA showed significantly inhibited proliferation and effectively induced apoptosis (P<0·05). When highly efficient and specific BCL11B-935-siRNA was used to analyze the inhibition of BCL11B mRNA level in primary T-cell acute lymphoblastic leukemia (T-ALL) cells, similar result was obtained. In conclusion, siRNAs targeting the different exon domains resulted in different silencing effects and biological consequences. Suppression of BCL11B by RNA interference could inhibit the proliferation and induce the apoptosis effectively in leukemic T cells, which might be considered as a new target therapeutic strategy in T-cell malignancies. PMID:21756541

  8. Magic and cognitive neuroscience.

    PubMed

    Quiroga, Rodrigo Quian

    2016-05-23

    In recent years, neuroscientists have shown an increasing interest in magic. One reason for this is the parallels that can be drawn between concepts that have long been discussed in magic theory, particularly misdirection, and those that are routinely studied in cognitive neuroscience, such as attention and, as argued in this essay, different forms of memory. A second and perhaps more attractive justification for this growing interest is that magic tricks offer novel experimental approaches to cognitive neuroscience. In fact, magicians continuously demonstrate in very engaging ways one of the most basic principles of brain function - how the brain constructs a subjective reality using assumptions based on relatively little and ambiguous information. PMID:27218839

  9. [Homeopathic medicine and magic].

    PubMed

    Angutek, Dorota

    2007-01-01

    The article compares homeopathic medicine and primitive magic. The author realises formal similarities beetwen these two fields of knowledge. The primitive homeopathic magic characterised by J. G. Frazer in his The Golden Bought announces that "similar courses similar". M. Mauss and H. Hubert added to this "low" an another formula: "similar acts on similar that courses a contrary phenomenon". The last formula is an identic one with the "low" of homeopathic medicine. Moreover there is a similarity between pantheistic religion of Hahnemann and magician beliefs in the power named mana in Melanesia and Polinesia or orenda, wakan, manitou and so on, by the Indians from The North America. The amazing thing is that homeopathic chemists belive that kinetic power transforms itself into esoteric one, during preparation of homeopathic medicines.In the end of this article the author ascertains that homeopathic medicine and magic has certain paradigm in common what is opposit to racionalism of official European paradigm of thinking. PMID:19244731

  10. Manufacturing Magic and Computational Creativity.

    PubMed

    Williams, Howard; McOwan, Peter W

    2016-01-01

    This paper describes techniques in computational creativity, blending mathematical modeling and psychological insight, to generate new magic tricks. The details of an explicit computational framework capable of creating new magic tricks are summarized, and evaluated against a range of contemporary theories about what constitutes a creative system. To allow further development of the proposed system we situate this approach to the generation of magic in the wider context of other areas of application in computational creativity in performance arts. We show how approaches in these domains could be incorporated to enhance future magic generation systems, and critically review possible future applications of such magic generating computers. PMID:27375533

  11. Manufacturing Magic and Computational Creativity

    PubMed Central

    Williams, Howard; McOwan, Peter W.

    2016-01-01

    This paper describes techniques in computational creativity, blending mathematical modeling and psychological insight, to generate new magic tricks. The details of an explicit computational framework capable of creating new magic tricks are summarized, and evaluated against a range of contemporary theories about what constitutes a creative system. To allow further development of the proposed system we situate this approach to the generation of magic in the wider context of other areas of application in computational creativity in performance arts. We show how approaches in these domains could be incorporated to enhance future magic generation systems, and critically review possible future applications of such magic generating computers. PMID:27375533

  12. The "magical" language of Mantra.

    PubMed

    Burchett, Patton E

    2008-01-01

    This paper aims to illuminate the phenomenon of mantras and to critique the category of magic through an examination of mantra as magical language. Mantras have often been referred to as "magic formulas" or "spells," yet one searches the scholarly literature in vain for a worthy explanation of precisely why mantra should or should not be considered magical. This essay addresses this lack, (a) explaining how mantra's conflict with modern Western understandings of language has led scholars to conceive of mantra as magic and (b) showing just what is at stake in such characterizations. This examination of mantra will demonstrate how "magic" and related terms have consistently been used not so much to describe as to marginalize and de-authorize that to which they refer. While the issue is partly about flawed terms and categories, the question of mantra as magic ultimately leads to an unsettling confrontation with the limits of our own modern rationalist perspective. PMID:20827826

  13. Neuroscience, Magic, and Counseling

    ERIC Educational Resources Information Center

    Echterling, Lennis G.; Presbury, Jack; Cowan, Eric

    2012-01-01

    Recent findings in neuroscience have identified principles, such as attention management and change blindness, which stage magicians exploit to create illusions. Neuroscientists have also revealed how mirror neurons and oxytocin enhance the impact of magic. In other words, magicians are just as much practitioners of sleight of mind as they are of…

  14. Magical Ideation and Schizophrenia.

    ERIC Educational Resources Information Center

    George, Leonard; Neufeld, Richard W. J.

    1987-01-01

    Administered the Eckblad and Chapman (1983) Magical Ideation Scale to groups of paranoid and nonparanoid schizophrenics and control subjects. Schizophrenics scored significantly higher than nonschizophrenic patients (mainly cases of affective disorder) and normal control subjects. Discusses theoretical and prognostic utility of this finding.…

  15. Helping, Manipulation, and Magic

    ERIC Educational Resources Information Center

    Frey, Louise A.; Edinburg, Golda M.

    1978-01-01

    The thesis of this article is that an understanding of the primitive origins of the helping process in myth, magic, and ritual may prevent social workers from engaging in practices that negate their clients' ability to work out their own solutions to problems. (Author)

  16. Sugar Cane Magic.

    ERIC Educational Resources Information Center

    Mower, Nancy Alpert

    The booklet contains a story for middle-grade students which shows how the roles of men and women change through the years. The main characters are three sixth graders in Hawaii: one girl has Hawaiian ancestors, one girl has Japanese ancestors, and one boy has New England missionary ancestors. The children discover a magic stalk of sugar cane…

  17. Thawing Out Some Magic

    ERIC Educational Resources Information Center

    Hippler, Arthur E.

    1975-01-01

    Psychiatrists have learned that delivering mental health services in a culture long dominated by magical thinking is not easy. Article discussed the problem of bringing the Eskimo into the care of the Alaska Psychiatric Institute and contemporary society. (Editor/RK)

  18. Magic, Morals and Health

    ERIC Educational Resources Information Center

    Johnson, Warren R.

    2010-01-01

    Magic has to do with the supernatural and the unnatural. It is indifferent to natural law and science and is aloof from scientific inquiry. Its existence depends upon unquestioning faith. Granted such faith, it is extraordinarily potent. If it does not move mountains, it convinces the faithful that it can. It can damage health and perhaps, restore…

  19. Biological Roles of Hydroxysteroid (11-Beta) Dehydrogenase 1 (HSD11B1), HSD11B2, and Glucocorticoid Receptor (NR3C1) in Sheep Conceptus Elongation.

    PubMed

    Brooks, Kelsey; Burns, Gregory; Spencer, Thomas E

    2015-08-01

    In sheep, the elongating conceptus synthesizes and secretes interferon tau (IFNT) as well as prostaglandins (PGs) and cortisol. The enzymes, hydroxysteroid (11-beta) dehydrogenase 1 (HSD11B1) and HSD11B2 interconvert cortisone and cortisol. In sheep, HSD11B1 is expressed and active in the conceptus trophectoderm as well as in the endometrial luminal epithelia; in contrast, HSD11B2 expression is most abundant in conceptus trophectoderm. Cortisol is a biologically active glucocorticoid and ligand for the glucocorticoid receptor (NR3C1 or GR) and mineralocorticoid receptor (NR3C2 or MR). Expression of MR is not detectable in either the ovine endometrium or conceptus during early pregnancy. In tissues that do not express MR, HSD11B2 protects cells from the growth-inhibiting and/or proapoptotic effects of cortisol, particularly during embryonic development. In study one, an in utero loss-of-function analysis of HSD11B1 and HSD11B2 was conducted in the conceptus trophectoderm using morpholino antisense oligonucleotides (MAOs) that inhibit mRNA translation. Elongating, filamentous conceptuses were recovered on Day 14 from ewes infused with control morpholino or HSD11B2 MAO. In contrast, HSD11B1 MAO resulted in severely growth-retarded conceptuses or conceptus fragments with apoptotic trophectoderm. In study two, clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 genome editing was used to determine the role of GR in conceptus elongation and development. Elongating, filamentous-type conceptuses (12-14 cm in length) were recovered from ewes gestating control embryos (n = 7/7) and gestating GR-edited embryos (n = 6/7). These results support the idea that the effects of HSD11B1-derived cortisol on conceptus elongation are indirectly mediated by the endometrium and are not directly mediated through GR in the trophectoderm. PMID:26085523

  20. Flavonoids exhibit diverse effects on CYP11B1 expression and cortisol synthesis

    SciTech Connect

    Cheng, Li-Chuan; Li, Lih-Ann

    2012-02-01

    CYP11B1 catalyzes the final step of cortisol biosynthesis. The effects of flavonoids on transcriptional expression and enzyme activity of CYP11B1 were investigated using the human adrenocortical H295R cell model. All tested nonhydroxylated flavones including 3′,4′-dimethoxyflavone, α-naphthoflavone, and β-naphthoflavone upregulated CYP11B1 expression and cortisol production, whereas apigenin and quercetin exhibited potent cytotoxicity and CYP11B1 repression at high concentrations. Nonhydroxylated flavones stimulated CYP11B1-catalyzed cortisol formation at transcriptional level. Resveratrol increased endogenous and substrate-supported cortisol production like nonhydroxylated flavones tested, but it had no effect on CYP11B1 gene expression and enzyme activity. Resveratrol appeared to alter cortisol biosynthesis at an earlier step. The Ad5 element situated in the − 121/− 106 region was required for basal and flavone-induced CYP11B1 expression. Overexpression of COUP-TFI did not improve the responsiveness of Ad5 to nonhydroxylated flavones. Although COUP-TFI overexpression increased CYP11B1 and CYP11B2 promoter activation, its effect was not mediated through the common Ad5 element. Treating cells with PD98059 (a flavone-type MEK1 inhibitor) increased CYP11B1 promoter activity, but not involving ERK signaling because phosphorylation of ERK1/2 remained unvarying throughout the course of treatment. Likewise, AhR was not responsible for the CYP11B1-modulating effects of flavonoids because inconsistency with their effects on AhR activation. 3′,4′-dimethoxyflavone and 8-Br-cAMP additively activated CYP11B1 promoter activity. H-89 reduced 3′,4′-dimethoxyflavone-induced CYP11B1 promoter activation but to a lesser extent as compared to its inhibition on cAMP-induced transactivation. Our data suggest that constant exposure to nonhydroxylated flavones raises a potential risk of high basal and cAMP-induced cortisol synthesis in consequence of increased CYP11B1

  1. Science meets magic: photonic metamaterials

    NASA Astrophysics Data System (ADS)

    Ozbay, Ekmel

    2012-05-01

    The word "magic" is usually associated with movies, fiction, children stories, etc. but seldom with the natural sciences. Recent advances in metamaterials have changed this notion, in which we can now speak of "almost magical" properties that scientists could only dream about only a decade ago. In this article, we review some of the recent "almost magical" progress in the field of meta-materials.

  2. Science meets magic: photonic metamaterials

    NASA Astrophysics Data System (ADS)

    Ozbay, Ekmel

    2012-03-01

    The word "magic" is usually associated with movies, fiction, children stories, etc. but seldom with the natural sciences. Recent advances in metamaterials have changed this notion, in which we can now speak of "almost magical" properties that scientists could only dream about only a decade ago. In this article, we review some of the recent "almost magical" progress in the field of meta-materials.

  3. Blazar Observations with the MAGIC Telescope

    NASA Astrophysics Data System (ADS)

    Kneiske, T. M.; Mannheim, K.

    The MAGIC Telescope will be able to detect gamma gay sources down to energies of 30GeV. Therefore a large number of sources will be seen, especially blazars. 30 GeV is also the upper energy limit of EGRET. Therefore it is possible to extrapolate a spectrum of an EGRET source without a complicated model. We make first predictions about the detectability of EGRET blazars calculating the minimum observation time for the MAGIC Telescope. Blazars are often located at high redshifts and their spectra should show some cut-offs at high energies due to pair production processes with low energy background photons. We developed a background radiation model using recent results of optical to infrared data and included this absorption effect in our calculation about the observability. We found that the shape of the spectrum and the intergalactic absorption does not make a big difference for a simple detection of the source. The observation time is only dependent on the flux near the energy threshold of the telescope (30 GeV) and the zenith angle of the blazar. The results are showing that MAGIC will be able to detect more than 50% of the EGRET sources even at high redshift and therefore it will be a good tool for multi-wavelength campaigns.

  4. Magical Landscapes: Two Love Stories.

    ERIC Educational Resources Information Center

    Moore, John Noell

    2002-01-01

    Introduces two books about magic, one a collection of essays "Ex Libris: Confessions of a Common Reader," which describes the author's inherited lifelong passion for books and reading; and the other a novel, "Mangos, Bananas and Coconuts: A Cuban Love Story," which tells a story of love and magic that seems both real and surreal. (SG)

  5. Garden Gnomes: Magical or Tacky?

    ERIC Educational Resources Information Center

    Flynt, Deborah

    2012-01-01

    Garden gnomes: magical or tacky? Well, art is in the eye of the beholder, and for the author's advanced seventh-grade art class, garden gnomes are magical. Gnomes have a very long history, dating back to medieval times. A fairytale describes them as brownie-like creatures that are nocturnal helpers. In this article, the author describes how her…

  6. Bcl11b is essential for group 2 innate lymphoid cell development

    PubMed Central

    Oliphant, Christopher J.; Englezakis, Alexandros; Yu, Yong; Clare, Simon; Rodewald, Hans-Reimer; Belz, Gabrielle; Liu, Pentao; Fallon, Padraic G.

    2015-01-01

    Group 2 innate lymphoid cells (ILC2s) are often found associated with mucosal surfaces where they contribute to protective immunity, inappropriate allergic responses, and tissue repair. Although we know they develop from a common lymphoid progenitor in the bone marrow (BM), the specific lineage path and transcriptional regulators that are involved are only starting to emerge. After ILC2 gene expression analysis we investigated the role of Bcl11b, a factor previously linked to T cell commitment, in ILC2 development. Using combined Bcl11b-tom and Id2-gfp reporter mice, we show that Bcl11b is expressed in ILC2 precursors in the BM and maintained in mature ILC2s. In vivo deletion of Bcl11b, by conditional tamoxifen-induced depletion or by Bcl11b−/− fetal liver chimera reconstitution, demonstrates that ILC2s are wholly dependent on Bcl11b for their development. Notably, in the absence of Bcl11b there is a concomitant expansion of the RORγt+ ILC3 population, suggesting that Bcl11b may negatively regulate this lineage. Using Nippostrongylus brasiliensis infection, we reveal that the absence of Bcl11b leads to impaired worm expulsion, caused by a deficit in ILC2s, whereas Citrobacter rodentium infection is cleared efficiently. These data clearly establish Bcl11b as a new factor in the differentiation of ILC2s. PMID:25964370

  7. Antiaging Gene Klotho Regulates Adrenal CYP11B2 Expression and Aldosterone Synthesis.

    PubMed

    Zhou, Xiaoli; Chen, Kai; Wang, Yongjun; Schuman, Mariano; Lei, Han; Sun, Zhongjie

    2016-06-01

    Deficiency of the antiaging gene Klotho (KL) induces renal damage and hypertension through unknown mechanisms. In this study, we assessed whether KL regulates expression of CYP11B2, a key rate-limiting enzyme in aldosterone synthesis, in adrenal glands. We found that haplodeficiency of KL(+/-) in mice increased the plasma level of aldosterone by 16 weeks of age, which coincided with spontaneous and persistent elevation of BP. Blockade of aldosterone actions by eplerenone reversed KL deficiency-induced hypertension and attenuated the kidney damage. Protein expression of CYP11B2 was upregulated in adrenal cortex of KL(+/-) mice. KL and CYP11B2 proteins colocalized in adrenal zona glomerulosa cells. Silencing of KL upregulated and overexpression of KL downregulated CYP11B2 expression in human adrenocortical cells. Notably, silencing of KL decreased expression of SF-1, a negative transcription factor of CYP11B2, but increased phosphorylation of ATF2, a positive transcription factor of CYP11B2, which may contribute to upregulation of CYP11B2 expression. Therefore, these results show that KL regulates adrenal CYP11B2 expression. KL deficiency-induced spontaneous hypertension and kidney damage may be partially attributed to the upregulation of CYP11B2 expression and aldosterone synthesis. PMID:26471128

  8. Old and New Magic Numbers

    SciTech Connect

    Talmi, Igal

    2008-11-11

    The discovery of magic numbers led to the shell model. They indicated closure of major shells and are robust: proton magic numbers are rather independent of the occupation of neutron orbits and vice versa. Recently the magic property became less stringent and we hear a lot about the discovery of new magic numbers. These, however, indicate sub-shell closures and strongly depend on occupation numbers and hence, may be called quasi-magic numbers. Some of these have been known for many years and the mechanism for their appearance as well as disappearance, was well understood within the simple shell model. The situation will be illustrated by a few examples which demonstrate the simple features of the shell model. Will this simplicity emerge from the complex computations of nuclear many-body theory?.

  9. "Magic" Ionization Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Trimpin, Sarah

    2016-01-01

    The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The "magic" that we were attempting to report was that with matrix assistance, molecules, at least as large as bovine serum albumin (66 kDa), are lifted into the gas phase as multiply charged ions simply by exposure of the matrix:analyte sample to the vacuum of a mass spectrometer. Applied heat, a laser, or voltages are not necessary to achieve charge states and ion abundances only previously observed with electrospray ionization (ESI). The fundamentals of how solid phase volatile or nonvolatile compounds are converted to gas-phase ions without added energy currently involves speculation providing a great opportunity to rethink mechanistic understanding of ionization processes used in mass spectrometry. Improved understanding of the mechanism(s) of these processes and their connection to ESI and matrix-assisted laser desorption/ionization may provide opportunities to further develop new ionization strategies for traditional and yet unforeseen applications of mass spectrometry. This Critical Insights article covers developments leading to the discovery of a seemingly magic ionization process that is simple to use, fast, sensitive, robust, and can be directly applied to surface characterization using portable or high performance mass spectrometers.

  10. Magical ideation and hyperacusis.

    PubMed

    Dubal, Stéphanie; Viaud-Delmon, Isabelle

    2008-01-01

    The subjective experience conferred by auditory perception has rarely been addressed outside of the studies of auditory hallucinations. The aim of this study is to describe the phenomenology of auditory experiences in individuals who endorse magical beliefs, but do not report hallucinations. We examined the relationship between subjective auditory sensitivity and a 'psychotic-like' thinking style. Hyperacusis questionnaire scores were compared between 25 high scoring participants on Chapman's magical ideation (MI) scale, 25 high scoring participants on Chapman's physical anhedonia scale and 25 control participants, pre-selected from a large student pool (n=1289). The participants who obtained high scores on the MI scale rated their auditory sensitivity higher than the two other groups. Our results indicate that, in healthy subjects, subjective auditory sensitivity is associated with MI without the mediation by anxiety commonly observed in pathological cases. We propose that hyperacusis associated to high scores of MI may be a predispositional factor to deviant auditory experiences. The relative uncoupling of perception from auditory sensory input may result in a central hypersensitivity, which could play a role in triggering off the experience of auditory hallucinations. PMID:18640670

  11. BCL11B regulates sutural patency in the mouse craniofacial skeleton.

    PubMed

    Kyrylkova, Kateryna; Iwaniec, Urszula T; Philbrick, Kenneth A; Leid, Mark

    2016-07-15

    The transcription factor BCL11B plays essential roles during development of the immune, nervous, and cutaneous systems. Here we show that BCL11B is expressed in both osteogenic and sutural mesenchyme of the developing craniofacial complex. Bcl11b(-/-) mice exhibit increased proliferation of osteoprogenitors, premature osteoblast differentiation, and enhanced skull mineralization leading to synostoses of facial and calvarial sutures. Ectopic expression of Fgfr2c, a gene implicated in craniosynostosis in mice and humans, and that of Runx2 was detected within the affected sutures of Bcl11b(-/-) mice. These data suggest that ectopic expression of Fgfr2c in the sutural mesenchyme, without concomitant changes in the expression of FGF ligands, appears to induce the RUNX2-dependent osteogenic program and craniosynostosis in Bcl11b(-/-) mice. PMID:26453795

  12. Bayesian Magic in Asteroseismology

    NASA Astrophysics Data System (ADS)

    Kallinger, T.

    2015-09-01

    Only a few years ago asteroseismic observations were so rare that scientists had plenty of time to work on individual data sets. They could tune their algorithms in any possible way to squeeze out the last bit of information. Nowadays this is impossible. With missions like MOST, CoRoT, and Kepler we basically drown in new data every day. To handle this in a sufficient way statistical methods become more and more important. This is why Bayesian techniques started their triumph march across asteroseismology. I will go with you on a journey through Bayesian Magic Land, that brings us to the sea of granulation background, the forest of peakbagging, and the stony alley of model comparison.

  13. Study of rlastic and inelastic {sup 11}B +α scattering and search for cluster states of enlarged radius in {sup 11}B

    SciTech Connect

    Danilov, A. N. Demyanova, A. S.; Dmitriev, S. V.; Ogloblin, A. A.; Belyaeva, T. L.; Goncharov, S. A.; Gurov, Yu. B.; Maslov, V. A.; Sobolev, Yu. G.; Trzaska, W.; Khlebnikov, S. V.; Heikkinen, P.; Julin, R.; Tyurin, G. P.; Burtebaev, N.; Zholdybayev, T.

    2015-09-15

    The differential cross sections for elastic and inelastic {sup 11}B + α scattering were measured at the alpha-particle energy of 65 MeV, the inelastic-scattering processes leading to the excitation of known states of {sup 11}B up to excitation energies of about 14 MeV. Data on elastic scattering were analyzed together with those that were published earlier for lower energies. The cross sections for inelastic scattering were analyzed on the basis of the distorted-wave method. A modified diffractionmodel was used to determine the root-mean-square radii of excited states. The radii of states whose excitation energies were below about 7MeV were found to agree with radius of the ground state to within 0.1 to 0.15 fm. This result complieswith the traditional idea that the low-lying states of {sup 11}B have a shell structure. The possibility that these states belong to the predicted rotational bands, which, if any, are truncated to three states, cannot be ruled out either. The majority of the observed highly excited states are distributed among four rotational bands. The moments of inertia of these bands are close; for the band based on the 3/2{sup −} state at E* = 8.56 MeV, they are even higher than those of the Hoyle state in the {sup 12}C nucleus. The measured radii of states associated with these bands of {sup 11}B are larger than the ground-state radius by 0.7 to 1.0 fm and are also close to the radius of the Hoyle state. The results of the present study agree with the existing predictions that the cluster structure of the {sup 11}B nucleus is diverse at high excitation energies. The hypothesis that the {sup 11}B nucleus features a “giant” state of size commensurate with those in heavy nuclei was not confirmed.

  14. Revealing ontological commitments by magic.

    PubMed

    Griffiths, Thomas L

    2015-03-01

    Considering the appeal of different magical transformations exposes some systematic asymmetries. For example, it is more interesting to transform a vase into a rose than a rose into a vase. An experiment in which people judged how interesting they found different magic tricks showed that these asymmetries reflect the direction a transformation moves in an ontological hierarchy: transformations in the direction of animacy and intelligence are favored over the opposite. A second and third experiment demonstrated that judgments of the plausibility of machines that perform the same transformations do not show the same asymmetries, but judgments of the interestingness of such machines do. A formal argument relates this sense of interestingness to evidence for an alternative to our current physical theory, with magic tricks being a particularly pure source of such evidence. These results suggest that people's intuitions about magic tricks can reveal the ontological commitments that underlie human cognition. PMID:25490128

  15. Extracellular Release of CD11b by TLR9 Stimulation in Macrophages

    PubMed Central

    Kim, Dongbum; Kim, Te Ha; Wu, Guang; Park, Byoung Kwon; Ha, Ji-Hee; Kim, Yong-Sung; Lee, Keunwook; Lee, Younghee; Kwon, Hyung-Joo

    2016-01-01

    CpG-DNA upregulates the expression of pro-inflammatory cytokines, chemokines and cell surface markers. Investigators have shown that CD11b (integrin αM) regulates TLR-triggered inflammatory responses in the macrophages and dendritic cells. Therefore, we aimed to identify the effects of CpG-DNA on the expression of CD11b in macrophages. There was no significant change in surface expression of CD11b after CpG-DNA stimulation. However, CD11b was released into culture supernatants after stimulation with phosphorothioate-backbone modified CpG-DNA such as PS-ODN CpG-DNA 1826(S). In contrast, MB-ODN 4531 and non-CpG-DNA control (regardless of backbone type and liposome-encapsulation) failed to induce release of CD11b. Therefore, the context of the CpG-DNA sequence and phosphorothioate backbone modification may regulate the effects of CpG-DNA on CD11b release. Based on inhibitor studies, CD11b release is mediated by p38 MAP kinase activation, but not by the PI3K and NF-κB activation. CD11b release is mediated by lysosomal degradation and by vacuolar acidification in response to CpG-DNA stimulation. The amount of CD11b in the exosome precipitant was significantly increased by CpG-DNA stimulation in vivo and in vitro depending on TLR9. Our observations perhaps give more insight into understanding of the mechanisms involved in CpG-DNA-induced immunomodulation in the innate immunity. PMID:26954233

  16. On the predictions of the 11B solid state NMR parameters

    NASA Astrophysics Data System (ADS)

    Czernek, Jiří; Brus, Jiří

    2016-07-01

    The set of boron containing compounds has been subject to the prediction of the 11B solid state NMR spectral parameters using DFT-GIPAW methods properly treating the solid phase effects. The quantification of the differences between measured and theoretical values has been presented, which is directly applicable in structural studies involving 11B nuclei. In particular, a simple scheme has been proposed, which is expected to provide for an estimate of the 11B chemical shift within ±2.0 ppm from the experimental value. The computer program, INFOR, enabling the visualization of concomitant Euler rotations related to the tensorial transformations has been presented.

  17. First Selective CYP11B1 Inhibitors for the Treatment of Cortisol-Dependent Diseases

    PubMed Central

    2010-01-01

    Outgoing from an etomidate-based design concept, we succeeded in the development of a series of highly active and selective inhibitors of CYP11B1, the key enzyme of cortisol biosynthesis, as potential drugs for the treatment of Cushing's syndrome and related diseases. Thus, compound 33 (IC50 = 152 nM) is the first CYP11B1 inhibitor showing a rather good selectivity toward the most important steroidogenic CYP enzymes aldosterone synthase (CYP11B2), the androgen-forming CYP17, and aromatase (estrogen synthase, CYP19). PMID:24900247

  18. Asynchronous combinatorial action of four regulatory factors activates Bcl11b for T cell commitment.

    PubMed

    Kueh, Hao Yuan; Yui, Mary A; Ng, Kenneth K H; Pease, Shirley S; Zhang, Jingli A; Damle, Sagar S; Freedman, George; Siu, Sharmayne; Bernstein, Irwin D; Elowitz, Michael B; Rothenberg, Ellen V

    2016-08-01

    During T cell development, multipotent progenitors relinquish competence for other fates and commit to the T cell lineage by turning on Bcl11b, which encodes a transcription factor. To clarify lineage commitment mechanisms, we followed developing T cells at the single-cell level using Bcl11b knock-in fluorescent reporter mice. Notch signaling and Notch-activated transcription factors collaborate to activate Bcl11b expression irrespectively of Notch-dependent proliferation. These inputs work via three distinct, asynchronous mechanisms: an early locus 'poising' function dependent on TCF-1 and GATA-3, a stochastic-permissivity function dependent on Notch signaling, and a separate amplitude-control function dependent on Runx1, a factor already present in multipotent progenitors. Despite their necessity for Bcl11b expression, these inputs act in a stage-specific manner, providing a multitiered mechanism for developmental gene regulation. PMID:27376470

  19. Molecular field theory analysis of R 3Co 11B 4 compounds

    NASA Astrophysics Data System (ADS)

    Xiang-Mu, Zhang; Rui-Wang, Huang; Zhong-Wu, Zhang

    2002-03-01

    The temperature dependence of magnetization of the R 3Co 11B 4 compounds has been analysed using the two-sublattice molecular field theory. The molecular field coefficients, nCoCo, nRCo, nRR, have been calculated by a numerical fitting process. The analytic form of the exchange field HR( T) varying with temperature for each of the R 3Co 11B 4 compounds is presented, and some results are discussed.

  20. Interstellar Travel without 'Magic'

    NASA Astrophysics Data System (ADS)

    Woodcock, G.

    The possibility of interstellar space travel has become a popular subject. Distances of light years are an entirely new realm for human space travel. New means of propulsion are needed. Speculation about propulsion has included "magic", space warps, faster-than-light travel, known physics such as antimatter for which no practical implementation is known and also physics for which current research offers at least a hint of implementation, i.e. fusion. Performance estimates are presented for the latter and used to create vehicle concepts. Fusion propulsion will mean travel times of hundreds of years, so we adopt the "space colony" concepts of O'Neill as a ship design that could support a small civilization indefinitely; this provides the technical means. Economic reasoning is presented, arguing that development and production of "space colony" habitats for relief of Earth's population, with addition of fusion engines, will lead to vessels that can go interstellar. Scenarios are presented and a speculative estimate of a timetable is given.

  1. "Magic" Ionization Mass Spectrometry.

    PubMed

    Trimpin, Sarah

    2016-01-01

    The systematic study of the temperature and pressure dependence of matrix-assisted ionization (MAI) led us to the discovery of the seemingly impossible, initially explained by some reviewers as either sleight of hand or the misinterpretation by an overzealous young scientist of results reported many years before and having little utility. The “magic” that we were attempting to report was that with matrix assistance, molecules, at least as large as bovine serum albumin (66 kDa), are lifted into the gas phase as multiply charged ions simply by exposure of the matrix:analyte sample to the vacuum of a mass spectrometer. Applied heat, a laser, or voltages are not necessary to achieve charge states and ion abundances only previously observed with electrospray ionization (ESI). The fundamentals of how solid phase volatile or nonvolatile compounds are converted to gas-phase ions without added energy currently involves speculation providing a great opportunity to rethink mechanistic understanding of ionization processes used in mass spectrometry. Improved understanding of the mechanism(s) of these processes and their connection to ESI and matrix-assisted laser desorption/ionization may provide opportunities to further develop new ionization strategies for traditional and yet unforeseen applications of mass spectrometry. This Critical Insights article covers developments leading to the discovery of a seemingly magic ionization process that is simple to use, fast, sensitive, robust, and can be directly applied to surface characterization using portable or high performance mass spectrometers. PMID:26486514

  2. Agonist Leukadherin-1 Increases CD11b/CD18-Dependent Adhesion Via Membrane Tethers

    PubMed Central

    Celik, Emrah; Faridi, Mohd. Hafeez; Kumar, Vinay; Deep, Shashank; Moy, Vincent T.; Gupta, Vineet

    2013-01-01

    Integrin CD11b/CD18 is a key adhesion receptor that mediates leukocyte migration and immune functions. Leukadherin-1 (LA1) is a small molecule agonist that enhances CD11b/CD18-dependent cell adhesion to its ligand ICAM-1. Here, we used single-molecule force spectroscopy to investigate the biophysical mechanism by which LA1-activated CD11b/CD18 mediates leukocyte adhesion. Between the two distinct populations of CD11b/CD18:ICAM-1 complex that participate in cell adhesion, the cytoskeleton(CSK)-anchored elastic elements and the membrane tethers, we found that LA1 enhanced binding of CD11b/CD18 on K562 cells to ICAM-1 via the formation of long membrane tethers, whereas Mn2+ additionally increased ICAM-1 binding via CSK-anchored bonds. LA1 activated wild-type and LFA1−/− neutrophils also showed longer detachment distances and time from ICAM-1-coated atomic force microscopy tips, but significantly lower detachment force, as compared to the Mn2+-activated cells, confirming that LA1 primarily increased membrane-tether bonds to enhance CD11b/CD18:ICAM-1 binding, whereas Mn2+ induced additional CSK-anchored bond formation. The results suggest that the two types of agonists differentially activate integrins and couple them to the cellular machinery, providing what we feel are new insights into signal mechanotransduction by such agents. PMID:24314082

  3. Novel Partners of SPAG11B Isoform D in the Human Male Reproductive Tract1

    PubMed Central

    Radhakrishnan, Yashwanth; Hamil, Katherine G.; Tan, Jiann-an; Grossman, Gail; Petrusz, Peter; Hall, Susan H.; French, Frank S.

    2009-01-01

    Human sperm-associated antigen 11 (SPAG11) is closely related to beta-defensins in structure, expression, and function. Like the beta-defensins, SPAG11 proteins are predominantly expressed in the male reproductive tract, where their best-known major roles are in innate host defense and reproduction. Although several hypotheses have emerged to describe the evolution of beta-defensin and SPAG11 multifunctionality, few describe these multiple functions in terms of defensin interactions with specific proteins. To gain insight into the protein interaction potentials of SPAG11 and the signaling pathways that SPAG11 may influence, we used a yeast two-hybrid screening of a human testis-epididymis library. The results reveal human SPAG11B isoform D (SPAG11B/D) interactions with tryptase alpha/beta 1 (TPSAB1), tetraspanin 7 (TSPAN7), and attractin (ATRN). These interactions were confirmed by coimmunoprecipitation and glutathione S-transferase affinity matrix binding. SPAG11B/D and the three interacting proteins are expressed in the proximal epididymis, and all function in immunity and fertility pathways. We analyzed the functional consequences of SPAG11B/D interaction with TPSAB1 and showed that SPAG11B/D is both a substrate and a potent inhibitor of TPSAB1 activity. Furthermore, we show that (like SPAG11B/D) TSPAN7 and ATRN are associated with spermatozoa. PMID:19535787

  4. BCL11B expression in intramembranous osteogenesis during murine craniofacial suture development

    PubMed Central

    Holmes, Greg; van Bakel, Harm; Zhou, Xueyan; Losic, Bojan; Jabs, Ethylin Wang

    2014-01-01

    Sutures, where neighboring craniofacial bones are separated by undifferentiated mesenchyme, are major growth sites during craniofacial development. Pathologic fusion of bones within sutures occurs in a wide variety of craniosynostosis conditions and can result in dysmorphic craniofacial growth and secondary neurologic deficits. Our knowledge of the genes involved in suture formation is poor. Here we describe the novel expression pattern of the BCL11B transcription factor protein during murine embryonic craniofacial bone formation. We examined BCL11B protein expression at E14.5, E16.5, and E18.5 in 14 major craniofacial sutures of C57BL/6J mice. We found BCL11B expression to be associated with all intramembranous craniofacial bones examined. The most striking aspects of BCL11B expression were its high levels in suture mesenchyme and increasingly complementary expression with RUNX2 in differentiating osteoblasts during development. BCL11B was also expressed in mesenchyme at the non-sutural edges of intramembranous bones. No expression was seen in osteoblasts involved in endochondral ossification of the cartilaginous cranial base. BCL11B is expressed to potentially regulate the transition of mesenchymal differentiation and suture formation within craniofacial intramembranous bone. PMID:25511173

  5. Migration of CD11b+ accessory cells during murine lung regeneration.

    PubMed

    Chamoto, Kenji; Gibney, Barry C; Lee, Grace S; Ackermann, Maximilian; Konerding, Moritz A; Tsuda, Akira; Mentzer, Steven J

    2013-05-01

    In many mammalian species, the removal of one lung leads to growth of the remaining lung to near-baseline levels. In studying post-pneumonectomy mice, we used morphometric measures to demonstrate neoalveolarization within 21 days of pneumonectomy. Of note, the detailed histology during this period demonstrated no significant pulmonary inflammation. To identify occult blood-borne cells, we used a parabiotic model (wild-type/GFP) of post-pneumonectomy lung growth. Flow cytometry of post-pneumonectomy lung digests demonstrated a rapid increase in the number of cells expressing the hematopoietic membrane molecule CD11b; 64.5% of the entire GFP(+) population were CD11b(+). Fluorescence microscopy demonstrated that the CD11b(+) peripheral blood cells migrated into both the interstitial tissue and alveolar airspace compartments. Pneumonectomy in mice deficient in CD11b (CD18(-/-) mutants) demonstrated near-absent leukocyte migration into the airspace compartment (p<.001) and impaired lung growth as demonstrated by lung weight (p<.05) and lung volume (p<.05). Transcriptional activity of the partitioned CD11b(+) cells demonstrated significantly increased transcription of Angpt1, Il1b, and Mmp8, Mmp9, Ncam1, Sele, Sell, Selp in the alveolar airspace and Adamts2, Ecm1, Egf, Mmp7, Npr1, Tgfb2 in the interstitial tissue (>4-fold regulation; p<.05). These data suggest that blood-borne CD11b(+) cells represent a population of accessory cells contributing to post-pneumonectomy lung growth. PMID:23376466

  6. Novel partners of SPAG11B isoform D in the human male reproductive tract.

    PubMed

    Radhakrishnan, Yashwanth; Hamil, Katherine G; Tan, Jiann-An; Grossman, Gail; Petrusz, Peter; Hall, Susan H; French, Frank S

    2009-10-01

    Human sperm-associated antigen 11 (SPAG11) is closely related to beta-defensins in structure, expression, and function. Like the beta-defensins, SPAG11 proteins are predominantly expressed in the male reproductive tract, where their best-known major roles are in innate host defense and reproduction. Although several hypotheses have emerged to describe the evolution of beta-defensin and SPAG11 multifunctionality, few describe these multiple functions in terms of defensin interactions with specific proteins. To gain insight into the protein interaction potentials of SPAG11 and the signaling pathways that SPAG11 may influence, we used a yeast two-hybrid screening of a human testis-epididymis library. The results reveal human SPAG11B isoform D (SPAG11B/D) interactions with tryptase alpha/beta 1 (TPSAB1), tetraspanin 7 (TSPAN7), and attractin (ATRN). These interactions were confirmed by coimmunoprecipitation and glutathione S-transferase affinity matrix binding. SPAG11B/D and the three interacting proteins are expressed in the proximal epididymis, and all function in immunity and fertility pathways. We analyzed the functional consequences of SPAG11B/D interaction with TPSAB1 and showed that SPAG11B/D is both a substrate and a potent inhibitor of TPSAB1 activity. Furthermore, we show that (like SPAG11B/D) TSPAN7 and ATRN are associated with spermatozoa. PMID:19535787

  7. Abject Magic: Reasoning Madness in Justine Larbalestier's "Magic or Madness" Trilogy

    ERIC Educational Resources Information Center

    Potter, Troy

    2013-01-01

    This paper explores the representation of magic and madness in Justine Larbalestier's "Magic or Madness" trilogy (2005-2007). Throughout the series, magic is constructed as an abject and disabling force that threatens to disable magic-wielders, either through madness or death. Despite being represented as a ubiquitous force, the…

  8. Airbag Trail Dubbed 'Magic Carpet'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] Click on the image for Airbag Trail Dubbed 'Magic Carpet' (QTVR)

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Magic Carpet Close-upMagic Carpet Close-up HD

    This section of the first color image from the Mars Exploration Rover Spirit has been further processed to produce a sharper look at a trail left by the one of rover's airbags. The drag mark was made after the rover landed and its airbags were deflated and retracted. Scientists have dubbed the region the 'Magic Carpet' after a crumpled portion of the soil that appears to have been peeled away (lower left side of the drag mark). Rocks were also dragged by the airbags, leaving impressions and 'bow waves' in the soil. The mission team plans to drive the rover over to this site to look for additional clues about the composition of the martian soil. This image was taken by Spirit's panoramic camera.

    This extreme close-up image (see insets above) highlights the martian feature that scientists have named 'Magic Carpet' because of its resemblance to a crumpled carpet fold. Scientists think the soil here may have detached from its underlying layer, possibly due to interaction with the Mars Exploration Rover Spirit's airbag after landing. This image was taken on Mars by the rover's panoramic camera.

  9. Finding All Solutions to the Magic Hexagram

    ERIC Educational Resources Information Center

    Holland, Jason; Karabegov, Alexander

    2008-01-01

    In this article, a systematic approach is given for solving a magic star puzzle that usually is accomplished by trial and error or "brute force." A connection is made to the symmetries of a cube, thus the name Magic Hexahedron.

  10. Magical attachment: Children in magical relations with hospital clowns

    PubMed Central

    2012-01-01

    The aim of the present study was to achieve a theoretical understanding of several different-age children's experiences of magic relations with hospital clowns in the context of medical care, and to do so using psychological theory and a child perspective. The method used was qualitative and focused on nine children. The results showed that age was important to consider in better understanding how the children experienced the relation with the hospital clowns, how they described the magical aspects of the encounter and how they viewed the importance of clown encounters to their own well-being. The present theoretical interpretation characterized the encounter with hospital clowns as a magical safe area, an intermediate area between fantasy and reality. The discussion presented a line of reasoning concerning a magical attachment between the child and the hospital clowns, stating that this attachment: a) comprised a temporary relation; b) gave anonymity; c) entailed reversed roles; and d) created an emotional experience of boundary-transcending opportunities. PMID:22371813

  11. CD11b(+) Mononuclear Cells Mitigate Hyperoxia-Induced Lung Injury in Neonatal Mice.

    PubMed

    Eldredge, Laurie C; Treuting, Piper M; Manicone, Anne M; Ziegler, Steven F; Parks, William C; McGuire, John K

    2016-02-01

    Bronchopulmonary dysplasia (BPD) is a common consequence of life-saving interventions for infants born with immature lungs. Resident tissue myeloid cells regulate lung pathology, but their role in BPD is poorly understood. To determine the role of lung interstitial myeloid cells in neonatal responses to lung injury, we exposed newborn mice to hyperoxia, a neonatal mouse lung injury model with features of human BPD. In newborn mice raised in normoxia, we identified a CD45(+) F4/80(+) CD11b(+), Ly6G(lo-int) CD71(+) population of cells in lungs of neonatal mice present in significantly greater percentages than in adult mice. In response to hyperoxia, surface marker and gene expression in whole lung macrophages/monocytes was biased to an alternatively activated phenotype. Partial depletion of these CD11b(+) mononuclear cells using CD11b-diphtheria toxin (DT) receptor transgenic mice resulted in 60% mortality by 40 hours of hyperoxia exposure with more severe lung injury, perivascular edema, and alveolar hemorrhage compared with DT-treated CD11b-DT receptor-negative controls, which displayed no mortality. These results identify an antiinflammatory population of CD11b(+) mononuclear cells that are protective in hyperoxia-induced neonatal lung injury in mice, and suggest that enhancing their beneficial functions may be a treatment strategy in infants at risk for BPD. PMID:26192732

  12. CD11b immunophenotyping identifies inflammatory profiles in the mouse and human lungs.

    PubMed

    Duan, M; Steinfort, D P; Smallwood, D; Hew, M; Chen, W; Ernst, M; Irving, L B; Anderson, G P; Hibbs, M L

    2016-03-01

    The development of easily accessible tools for human immunophenotyping to classify patients into discrete disease endotypes is advancing personalized therapy. However, no systematic approach has been developed for the study of inflammatory lung diseases with often complex and highly heterogeneous disease etiologies. We have devised an internally standardized flow cytometry approach that can identify parallel inflammatory alveolar macrophage phenotypes in both the mouse and human lungs. In mice, lung innate immune cell alterations during endotoxin challenge, influenza virus infection, and in two genetic models of chronic obstructive lung disease could be segregated based on the presence or absence of CD11b alveolar macrophage upregulation and lung eosinophilia. Additionally, heightened alveolar macrophage CD11b expression was a novel feature of acute lung exacerbations in the SHIP-1(-/-) model of chronic obstructive lung disease, and anti-CD11b antibody administration selectively blocked inflammatory CD11b(pos) but not homeostatic CD11b(neg) alveolar macrophages in vivo. The identification of analogous profiles in respiratory disease patients highlights this approach as a translational avenue for lung disease endotyping and suggests that heterogeneous innate immune cell phenotypes are an underappreciated component of the human lung disease microenvironment. PMID:26422753

  13. Radiological properties of MAGIC normoxic polymer gel dosimetry

    NASA Astrophysics Data System (ADS)

    Aljamal, M.; Zakaria, A.; Shamsuddin, S.

    2013-04-01

    For a polymer gel dosimeter to be of use in radiation dosimetry, it should display water-equivalent radiological properties. In this study, the radiological properties of the MAGIC (Methacrylic and Ascorbic acid in Gelatin Initiated by Copper) normoxic polymer gels were investigated. The mass density (ρ) was determined based on Archimedes' principle. The weight fraction of elemental composition and the effective atomic number (Zeff) were calculated. The electron density was also measured with 90° scattering angle at room temperature. The linear attenuation coefficient (μ) of unirradiated gel, irradiated gel, and water were determined using Am-241 based on narrow beam geometry. Monte Carlo simulation was used to calculate the depth doses response of MAGIC gel and water for 6MV photon beam. The weight fractions of elements composition of MAGIC gel were close to that for water. The mass density was found to be 1027 ± 2 kg m-3, which is also very close to mass density of muscle tissue (1030 kg m-3) and 2.7% higher than that of water. The electron density (ρe) and atomic number (Zeff) were found to be 3.43 × 1029 e m-3 and 7.105, respectively. The electron density measured was 2.6% greater than that for water. The atomic number was very close to that for water. The prepared MAGIC gel was found to be water equivalent based on the study of element composition, mass density, electron density and atomic number. The linear attenuation coefficient of unirradiated gel was very close to that of water. The μ of irradiated gel was found to be linear with dose 2-40 Gy. The depth dose response for MAGIC gel from a 6 MV photon beam had a percentage dose difference to water of less than 1%. Therefore it satisfies the criteria to be a good polymer gel dosimeter for radiotherapy.

  14. Experimental Study of p-11B Reaction Related to the Clean Fusion Fuel

    NASA Astrophysics Data System (ADS)

    Lin, Erh-kang; Wang, Chang-wan; Yuan, Jian; Liu, Xiao-dong; Li, Cheng-bo; Sun, Zu-xun; Zhang, Pei-hua; Chen, Jin-xiang; Yang, Qi-xiang; Wang, Jian-yong; Ling-hua, Gong

    1998-11-01

    Whole continuous α spectra of the p-11B three-body sequential decay reaction have been measured by using a charge particle time-of-flight (TOF) spectrometer with the high-resolution passivated implanted planar silicon detector. A characteristic shape of the saddle-type distribution was obtained. The Monte Carlo calculations show that observed α spectra can be interpreted by anisotropy sequential decay process of the intermediate nucleus 8Be (1) for the p-11B reaction. In the measurement, angular distributions were obtained for proton energies at 667 and 1370 keV, respectively. Total cross-sections for the 11B(p,α)8Be(2α) reaction related to the clean fusion fuel were also reported at two bombarding energies.

  15. 11B and constraints on neutrino oscillations and spectra from neutrino nucleosynthesis.

    PubMed

    Austin, Sam M; Heger, Alexander; Tur, Clarisse

    2011-04-15

    We study the sensitivity to variations in the triple-alpha and 12C(α,γ)16O reaction rates, of the yield of the neutrino-process isotopes 7Li, 11B, 19F, 138La, and 180Ta in core-collapse supernovae. Compared to solar abundances, less than 15% of 7Li, about 25%-80% of 19F, and about half of 138La is produced in these stars. Over a range of ±2σ for each helium-burning rate, 11B is overproduced and the yield varies by an amount larger than the variation caused by the effects of neutrino oscillations. The total 11B yield, however, may eventually provide constraints on supernova neutrino spectra. PMID:21568548

  16. GRB neutrino search with MAGIC

    SciTech Connect

    Becker, Julia K.; Rhode, Wolfgang; Gaug, Markus

    2008-05-22

    The Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescope was designed for the detection of photon sources > or approx. 50 GeV. The measurement of highly-inclined air showers renders possible the search for high-energy neutrinos, too. Only neutrinos can traverse the Earth without interaction, and therefore, events close to the horizon can be identified as neutrino-induced rather than photon-induced or hadronic events. In this paper, Swift-XRT-detected GRBs with given spectral information are used in order to calculate the potential neutrino energy spectrum from prompt and afterglow emission for each individual GRB. The event rate in MAGIC is estimated assuming that the GRB happens within the field of view of MAGIC. A sample of 568 long GRBs as detected by BATSE is used to compare the detection rates with 163 Swift-detected bursts. BATSE has properties similar to the Gamma-ray Burst Monitor (GBM) on board of GLAST. Therefore the estimated rates give an estimate for the possibilities of neutrino detection with MAGIC from GLAST-triggered bursts.

  17. Magic and the School Counselor.

    ERIC Educational Resources Information Center

    Spruill, David A.; Poidevant, John M.

    1993-01-01

    Discusses philosophy used to build student interest in various lesson topics taught to guidance groups. Presents three magic activities complete with lesson plans: How to Change Big Problems into Little Ones and How to Keep Little Problems from Getting Bigger; Teaching Friendship Skills and Becoming Aware of Your Feelings; and What Does Your…

  18. Hypertonicity compromises renal mineralocorticoid receptor signaling through Tis11b-mediated post-transcriptional control.

    PubMed

    Viengchareun, Say; Lema, Ingrid; Lamribet, Khadija; Keo, Vixra; Blanchard, Anne; Cherradi, Nadia; Lombès, Marc

    2014-10-01

    The mineralocorticoid receptor (MR) mediates the Na(+)-retaining action of aldosterone. MR is highly expressed in the distal nephron, which is submitted to intense variations in extracellular fluid tonicity generated by the corticopapillary gradient. We previously showed that post-transcriptional events control renal MR abundance. Here, we report that hypertonicity increases expression of the mRNA-destabilizing protein Tis11b, a member of the tristetraprolin/ZFP36 family, and thereby, decreases MR expression in renal KC3AC1 cells. The 3'-untranslated regions (3'-UTRs) of human and mouse MR mRNA, containing several highly conserved adenylate/uridylate-rich elements (AREs), were cloned downstream of a reporter gene. Luciferase activities of full-length or truncated MR Luc-3'-UTR mutants decreased drastically when cotransfected with Tis11b plasmid, correlating with an approximately 50% shorter half-life of ARE-containing transcripts. Using site-directed mutagenesis and RNA immunoprecipitation, we identified a crucial ARE motif within the MR 3'-UTR, to which Tis11b must bind for destabilizing activity. Coimmunoprecipitation experiments suggested that endogenous Tis11b physically interacts with MR mRNA in KC3AC1 cells, and Tis11b knockdown prevented hypertonicity-elicited repression of MR. Moreover, hypertonicity blunted aldosterone-stimulated expression of glucocorticoid-induced leucine-zipper protein and the α-subunit of the epithelial Na(+) channel, supporting impaired MR signaling. Challenging the renal osmotic gradient by submitting mice to water deprivation, diuretic administration, or high-Na(+) diet increased renal Tis11b and decreased MR expression, particularly in the cortex, thus establishing a mechanistic pathway for osmotic regulation of MR expression in vivo. Altogether, we uncovered a mechanism by which renal MR expression is regulated through mRNA turnover, a post-transcriptional control that seems physiologically relevant. PMID:24700863

  19. Hypertonicity Compromises Renal Mineralocorticoid Receptor Signaling through Tis11b-Mediated Post-Transcriptional Control

    PubMed Central

    Viengchareun, Say; Lema, Ingrid; Lamribet, Khadija; Keo, Vixra; Blanchard, Anne

    2014-01-01

    The mineralocorticoid receptor (MR) mediates the Na+-retaining action of aldosterone. MR is highly expressed in the distal nephron, which is submitted to intense variations in extracellular fluid tonicity generated by the corticopapillary gradient. We previously showed that post-transcriptional events control renal MR abundance. Here, we report that hypertonicity increases expression of the mRNA-destabilizing protein Tis11b, a member of the tristetraprolin/ZFP36 family, and thereby, decreases MR expression in renal KC3AC1 cells. The 3′-untranslated regions (3′-UTRs) of human and mouse MR mRNA, containing several highly conserved adenylate/uridylate-rich elements (AREs), were cloned downstream of a reporter gene. Luciferase activities of full-length or truncated MR Luc-3′-UTR mutants decreased drastically when cotransfected with Tis11b plasmid, correlating with an approximately 50% shorter half-life of ARE-containing transcripts. Using site-directed mutagenesis and RNA immunoprecipitation, we identified a crucial ARE motif within the MR 3′-UTR, to which Tis11b must bind for destabilizing activity. Coimmunoprecipitation experiments suggested that endogenous Tis11b physically interacts with MR mRNA in KC3AC1 cells, and Tis11b knockdown prevented hypertonicity-elicited repression of MR. Moreover, hypertonicity blunted aldosterone-stimulated expression of glucocorticoid-induced leucine-zipper protein and the α-subunit of the epithelial Na+ channel, supporting impaired MR signaling. Challenging the renal osmotic gradient by submitting mice to water deprivation, diuretic administration, or high-Na+ diet increased renal Tis11b and decreased MR expression, particularly in the cortex, thus establishing a mechanistic pathway for osmotic regulation of MR expression in vivo. Altogether, we uncovered a mechanism by which renal MR expression is regulated through mRNA turnover, a post-transcriptional control that seems physiologically relevant. PMID:24700863

  20. M31N2008-11b is a Galactic Dwarf Nova

    NASA Astrophysics Data System (ADS)

    Kasliwal, M. M.; Quimby, R.; Kulkarni, S. R.

    2008-12-01

    We observed M31N2008-11b (K. Itagaki, CBET#1588) with the Double Beam Spectrograph on the Palomar Hale 5-m telescope on UT Dec 4.221. This spectrum has a steep blue continuum, very narrow emission in H-alpha and broad absorption in H-beta through at least H-eta. Further, there is a faint blue counterpart in SDSS DR Supplement g-band imaging (g=22.8, r > 23.3).

  1. B/Nb and δ 11B systematics in the Phlegrean Volcanic District, Italy

    NASA Astrophysics Data System (ADS)

    Tonarini, S.; Leeman, W. P.; Civetta, L.; D'Antonio, M.; Ferrara, G.; Necco, A.

    2004-05-01

    Boron concentration and isotopic compositions were determined in representative products from the Phlegrean Volcanic District (PVD), which includes Campi Flegrei (CF), and the islands of Procida and Ischia. The most primitive products (from Procida and Ischia islands) are moderately enriched in B (4.6-12 ppm), whereas more evolved products of CF and Ischia Island are more enriched (21-118 ppm). The content of B is positively correlated with Nb, Zr, Th, La and, generally, with all incompatible elements. δ 11B values are generally lower and more uniform in samples from CF (-6.8 to - 10.6‰) compared with those from Procida (-3.6 to -8.5‰) and Ischia (-2.8 to -8.4‰) islands. Overall, B-enrichments relative to fluid-immobile elements of PVD are only slightly higher than those observed in mid-ocean ridge basalts and there is no significant correlation between δ 11B and B/immobile element ratios. For CF samples including the Campanian Ignimbrite (CI) and most post-CI products, δ 11B is negatively correlated with 87Sr/ 86Sr, with extreme compositions represented by evolved products of the CI (higher δ 11B, lower 87Sr/ 86Sr) and less evolved shoshonite (lower δ 11B, higher 87Sr/ 86Sr). In contrast, samples from Procida, Ischia, and pre-CI products and one young shoshonite from CF define a distinct correlation with primitive trachybasalt as the high δ 11B, low 87Sr/ 86Sr end-member, and young shoshonites as the low δ 11B, high 87Sr/ 86Sr end-member. The overall interpretation of the geochemical and isotopic data suggests three conclusions: (1) Geochemical and isotopic variations of post-CI products from CF can be explained by mixing/mingling between at least two distinct magmas, i.e. the CI and the young shoshonite (Minopoli 1). (2) The isotopic trend described by Procida trachybasalts, Ischia samples, pre-CI samples from CF and Pigna St. Nicola shoshonite is a mantle trend suggesting the involvement in their genesis of a distinct component depleted in B, with

  2. An update on 11B,10B fractionation in the fundamental reaction: 10B(OH)3 + 11B(OH)4- = 11B(OH)3 + 10B(OH)4-

    NASA Astrophysics Data System (ADS)

    Klochko, K.; Tossell, J. A.

    2007-12-01

    It has recently been demonstrated experimentally by Byrne, et al. (2006) and Klochko, et al. (2006) that the equilibrium constant for the isotopic exchange reaction: 10B(OH)3 + 11B(OH)4- = 11B(OH)3 + 10B(OH)4- (1) has a value around 1.027 for seawater at 25°C, for total B concentrations from 0.01 to 0.05 molal. These experimental studies involved essentially the accurate determination of the small pKa difference between the 11B and 10B isotopomers of boric acid. This new equilibrium constant value is significantly higher than the traditional value of 1.0194 from Kakihana, et al. (1977). This result has been obscured in recent controversies (Honisch, et al., 2007). The new value agrees well with the ab initio quantum cluster calculated values of Liu and Tossell (2005) and with the ab initio MD harmonic values of Rustad and Bylaska (2007). We will present additional calculations supporting and extending the study of Liu and Tossell (2005) and will discuss the general unsuitability of methods such as Sanchez-Valle, et al. (2005) which employ experimental spectral data. We have also established that polyborate formation in solutions as concentrated as 0.50 molal total B has little effect on the equilibrium constant. A mechanism is also presented for the interaction of B(OH)3 and B(OH)4- with HCO3- species occurring on the calcite surface. References: Byrne, et al. Deep-Sea Research I (2006) 53, 684-688. Honisch, et al. Geochim. Cosmochim. Acta (2007) 71, 1636-1641. Kakihana, et al. Bull. Chem. Soc. Jpn. (1977) 50, 158-163. Klochko, et al. Earth Planet. Sci. Lett. (2006) 248, 276-285. Liu and Tossell Geochim. Cosmochim. Acta (2005) 69, 3995-4006. Rustad and Bylaska J. Am. Chem. Soc. (2007) 129, 2222-2223. Sanchez-Valle, et al. Geochim. Cosmochim. Acta (2005) 69, 4301-4313.

  3. Magic star puzzle for educational mathematics

    NASA Astrophysics Data System (ADS)

    Gan, Yee Siang; Fong, Wan Heng; Sarmin, Nor Haniza

    2013-04-01

    One of the interesting fields in recreational mathematics is the magic number arrangement. There are different kinds of arrays in the arrangement for a group of numbers. In particular, one of the arrays in magic number arrangement is called magic star. In fact, magic star involves combinatorics that contributes to geometrical analysis and number theory. Hence, magic star is suitable to be introduced as educational mathematics to cultivate interest in different area of mathematics. To obtain the solutions of normal magic stars of order six, the possible sets of numbers for every line in a magic star have been considered. Previously, the calculation for obtaining the solutions has been done manually which is time-consuming. Therefore, a programming code to generate all the fundamental solutions for normal magic star of order six without including the properties of rotation and reflection has been done. In this puzzle, a magic star puzzle is created by using Matlab software, which enables a user to verify the entries for the cells of magic star of order six. Moreover, it is also user-friendly as it provides interactive commands on the inputs given by the user, which enables the user to detect the incorrect inputs. In addition, user can also choose to view all the fundamental solutions as generated by the programming code.

  4. Transcription factor Bcl11b controls identity and function of mature innate lymphoid cells type II

    PubMed Central

    Califano, Danielle; Cho, Jonathan J.; Uddin, Mohammad N.; Lorentsen, Kyle J.; Yang, Qi; Bhandoola, Avinash; Li, Hongmin; Avram, Dorina

    2015-01-01

    Summary Type-2 innate lymphoid cells (ILC2s) promote anti-helminth responses and contribute to allergies. Here we report that Bcl11b, previously considered a T-cell lineage identity transcription factor, acts directly upstream of the key ILC2 transcription factor Gfi1 to maintain its expression in mature ILC2s. Consequently, Bcl11b−/− ILC2s downregulated Gata3 and downstream genes, including Il1rl1, encoding IL-33 receptor, and upregulated Rorc and type-3 ILC (ILC3) genes. Additionally, independent of Gfi1, Bcl11b directly repressed expression of the ILC3 transcription factor Ahr, further contributing to silencing of ILC3 genes in ILC2s. Thus, Bcl11b−/− ILC2s lost their functions and gained ILC3 functions, expanding in response to the protease allergen papain, while at the same time producing ILC3, and not ILC2 cytokines, and causing increased airway infiltration of neutrophils instead of eosinophils. Our results broaden Bcl11b's role from a T-cell only transcription factor, and establish that Bcl11b sustains mature ILC2 genetic and functional programs and lineage fidelity. PMID:26231117

  5. Discovery of Triazole CYP11B2 Inhibitors with in Vivo Activity in Rhesus Monkeys

    PubMed Central

    2015-01-01

    Hit-to-lead efforts resulted in the discovery of compound 19, a potent CYP11B2 inhibitor that displays high selectivity vs related CYPs, good pharmacokinetic properties in rat and rhesus, and lead-like physical properties. In a rhesus pharmacodynamic model, compound 19 displays robust, dose-dependent aldosterone lowering efficacy, with no apparent effect on cortisol levels. PMID:26288685

  6. Bcl11b: A New Piece to the Complex Puzzle of Amyotrophic Lateral Sclerosis Neuropathogenesis?

    PubMed

    Lennon, Matthew J; Jones, Simon P; Lovelace, Michael D; Guillemin, Gilles J; Brew, Bruce J

    2016-02-01

    Amyotrophic lateral sclerosis (ALS) is an idiopathic, fatal, neurodegenerative disease of the human motor system. The pathogenesis of ALS is a topic of fascinating speculation and experimentation, with theories revolving around intracellular protein inclusions, mitochondrial structural issues, glutamate excitotoxicity and free radical formation. This review explores the rationale for the involvement of a novel protein, B-cell lymphoma/leukaemia 11b (Bcl11b) in ALS. Bcl11b is a multifunctional zinc finger protein transcription factor. It functions as both a transactivator and genetic suppressor, acting both directly, binding to promoter regions, and indirectly, binding to promoter-bound transcription factors. It has essential roles in the differentiation and growth of various cells in the central nervous system, immune system, integumentary system and cardiovascular system, to the extent that Bcl11b knockout mice are incompatible with extra-uterine life. It also has various roles in pathology including the suppression of latent retroviruses, thymic tumourigenesis and neurodegeneration. In particular its functions in neurodevelopment, viral latency and T-cell development suggest potential roles in ALS pathology. PMID:26563995

  7. Heparin Interaction with the Primed Polymorphonuclear Leukocyte CD11b Induces Apoptosis and Prevents Cell Activation

    PubMed Central

    Cohen-Mazor, Meital; Mazor, Rafi; Kristal, Batya; Kistler, Erik B.; Ziv, Inbal; Chezar, Judith; Sela, Shifra

    2015-01-01

    Heparin is known to have anti-inflammatory effects, yet the mechanisms are not completely understood. In this study, we tested the hypothesis that heparin has a direct effect on activated polymorphonuclear leukocytes (PMNLs), changing their activation state, and can explain its anti-inflammatory effect. To test our hypothesis, we designed both in vitro and ex vivo studies to elucidate the mechanism by which heparin modulates PMNL functions and therefore the inflammatory response. We specifically tested the hypothesis that priming of PMNLs renders them more susceptible to heparin. Amplified levels of CD11b and increased rate of superoxide release manifested PMNL priming. Increase in cell priming resulted in a dose-dependent increase in heparin binding to PMNLs followed by augmented apoptosis. Blocking antibodies to CD11b inhibited heparin binding and abolished the apoptotic response. Moreover, heparin caused a significant dose-dependent decrease in the rate of superoxide release from PMNLs, which was blunted by blocking antibodies to CD11b. Altogether, this study shows that the interaction of heparin with the PMNL CD11b results in cell apoptosis and explains heparin's anti-inflammatory effects. PMID:26819958

  8. Prostate cancer promotes CD11b positive cells to differentiate into osteoclasts

    PubMed Central

    Mizutani, Kosuke; Sud, Sudha; Pienta, Kenneth J

    2009-01-01

    Bone is the preferred site of prostate cancer metastasis, contributing to the morbidity and mortality of this disease. A key step in the successful establishment of prostate cancer bone metastases is activation of osteoclasts with subsequent bone resorption causing the release of several growth factors from the bone matrix. CD11b+ cells in bone marrow are enriched for osteoclast precursors. Conditioned media from prostate cancer PC-3 cells induces CD11b+ cells from human peripheral blood to differentiate into functional osteoclasts with subsequent bone resorption. Analysis of PC-3 conditioned media revealed high amounts of IL-6 and IL-8. CD11b+ cells were cultured with M-CSF and RANKL, IL-6, IL-8 and CCL2, alone or in combination. All of these conditions induced osteoclast fusion, but cells cultured with M-CSF, IL-6, IL-8 and CCL2 were capable of limited bone resorption. Co-incubation with IL-6 and IL-8 and the RANK inhibitor, RANK-Fc, failed to inhibit osteoclast fusion and bone resorption, suggesting a potential RANKL-independent mechanism of functional osteoclast formation. This study demonstrates that functional osteoclasts can be derived from CD11b+ cells derived from human PBMCs. Prostate cancer cells secrete factors, including IL-6 and IL-8, that play an important role in osteoclast fusion by a RANKL-independent mechanism. PMID:19170075

  9. Immunosuppressive CD11b+Ly6Chi monocytes in pristane-induced lupus mouse model.

    PubMed

    Ma, Huijuan; Wan, Suigui; Xia, Chang-Qing

    2016-06-01

    Myeloid-derived suppressor cells with immunosuppressive functions have been described to be associated with one of the mechanisms by which malignant tumors escape immune surveillance. However, little is known about the role of myeloid-derived suppressor cells in autoimmunity. In the current study, when we attempted to characterize the peritoneal cells in pristane-induced lupus model, as reported previously, we observed that there were markedly increased CD11b(+)Ly6C(hi) monocytes. Surprisingly, this type of monocytes was almost phenotypically identical to the reported monocytic myeloid-derived suppressor cells. Further analysis on how these CD11b(+)Ly6C(hi) cells affected T cell response showed that they strongly suppressed T cell proliferation in vitro in a manner dependent on cell-cell contact, NO, and PGE2. In addition, we found that CD11b(+)Ly6C(hi) monocytes inhibited Th1 differentiation but enhanced development of forkhead box p3(+)CD4(+) regulatory T cells. Consistent with the in vitro experimental results, the in vivo adoptive cell transfer study showed that infusion of pristane-treated syngeneic CD11b(+)Ly6C(hi) monocytes significantly suppressed the production of anti-keyhole limpet hemocyanin antibodies induced by keyhole limpet hemocyanin immunization. In addition, we found that CD11b(+)Ly6C(hi) monocytes were also increased significantly in spleen and peripheral blood and showed immunosuppressive characteristics similar to their peritoneal counterparts. Our findings indicate that CD11b(+)Ly6C(hi) monocytes in a pristane-induced lupus mouse model are monocytic myeloid-derived suppressor cells instead of inflammatory monocytes, as demonstrated previously. To our knowledge, this is the first to describe myeloid-derived suppressor cells in a pristane-induced lupus mouse model, which may lead to a better understanding of the role of CD11b(+)Ly6C(hi) monocytes in this specific pristane-induced lupus model. PMID:26657791

  10. Towards a science of magic.

    PubMed

    Kuhn, Gustav; Amlani, Alym A; Rensink, Ronald A

    2008-09-01

    It is argued here that cognitive science currently neglects an important source of insight into the human mind: the effects created by magicians. Over the centuries, magicians have learned how to perform acts that are perceived as defying the laws of nature, and that induce a strong sense of wonder. This article argues that the time has come to examine the scientific bases behind such phenomena, and to create a science of magic linked to relevant areas of cognitive science. Concrete examples are taken from three areas of magic: the ability to control attention, to distort perception, and to influence choice. It is shown how such knowledge can help develop new tools and indicate new avenues of research into human perception and cognition. PMID:18693130

  11. Magic Carpet Shows Its Colors

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The upper left image in this display is from the panoramic camera on the Mars Exploration Rover Spirit, showing the 'Magic Carpet' region near the rover at Gusev Crater, Mars, on Sol 7, the seventh martian day of its journey (Jan. 10, 2004). The lower image, also from the panoramic camera, is a monochrome (single filter) image of a rock in the 'Magic Carpet' area. Note that colored portions of the rock correlate with extracted spectra shown in the plot to the side. Four different types of materials are shown: the rock itself, the soil in front of the rock, some brighter soil on top of the rock, and some dust that has collected in small recesses on the rock face ('spots'). Each color on the spectra matches a line on the graph, showing how the panoramic camera's different colored filters are used to broadly assess the varying mineral compositions of martian rocks and soils.

  12. Secrets of the Chinese magic mirror replica

    NASA Astrophysics Data System (ADS)

    Mak, Se-yuen; Yip, Din-yan

    2001-03-01

    We examine the structure of five Chinese magic mirror replicas using a special imaging technique developed by the authors. All mirrors are found to have a two-layered structure. The reflecting surface that gives rise to a projected magic pattern on the screen is hidden under a polished half-reflecting top layer. An alternative method of making the magic mirror using ancient technology has been proposed. Finally, we suggest a simple method of reconstructing a mirror replica in the laboratory.

  13. Improved Superconducting properties in the Mg11B2 low activation superconductor prepared by low-temperature sintering

    NASA Astrophysics Data System (ADS)

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, M.; Somer, M.

    2016-05-01

    Mg11B2 has a great application prospect in the superconducting coils for fusion reactor as the “low activation superconductors”. The un-doped Mg11B2 and Cu-doped Mg11B2 bulks using 11B as a boron precursor were fabricated by low-temperature sintering in present work. It was found that the prepared Mg11B2 low activation superconductors exhibit better Jc performance than all of other Mg11B2 samples reported in previous studies. As for Cu doped Mg11B2, minor Cu addition can obviously improve the Mg11B2 grain crystallization and reduce the amount of MgO impurity. Hence, improved grain connectivity and higher Jc at low fields is obtained in Cu doped Mg11B2 samples. For un-doped samples, refined grains and more MgO impurity with proper size brought about more flux pinning centers, resulting in better Jc performance at high fields.

  14. Improved Superconducting properties in the Mg(11)B2 low activation superconductor prepared by low-temperature sintering.

    PubMed

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, M; Somer, M

    2016-01-01

    Mg(11)B2 has a great application prospect in the superconducting coils for fusion reactor as the "low activation superconductors". The un-doped Mg(11)B2 and Cu-doped Mg(11)B2 bulks using (11)B as a boron precursor were fabricated by low-temperature sintering in present work. It was found that the prepared Mg(11)B2 low activation superconductors exhibit better Jc performance than all of other Mg(11)B2 samples reported in previous studies. As for Cu doped Mg(11)B2, minor Cu addition can obviously improve the Mg(11)B2 grain crystallization and reduce the amount of MgO impurity. Hence, improved grain connectivity and higher Jc at low fields is obtained in Cu doped Mg(11)B2 samples. For un-doped samples, refined grains and more MgO impurity with proper size brought about more flux pinning centers, resulting in better Jc performance at high fields. PMID:27149682

  15. Improved Superconducting properties in the Mg11B2 low activation superconductor prepared by low-temperature sintering

    PubMed Central

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, M.; Somer, M.

    2016-01-01

    Mg11B2 has a great application prospect in the superconducting coils for fusion reactor as the “low activation superconductors”. The un-doped Mg11B2 and Cu-doped Mg11B2 bulks using 11B as a boron precursor were fabricated by low-temperature sintering in present work. It was found that the prepared Mg11B2 low activation superconductors exhibit better Jc performance than all of other Mg11B2 samples reported in previous studies. As for Cu doped Mg11B2, minor Cu addition can obviously improve the Mg11B2 grain crystallization and reduce the amount of MgO impurity. Hence, improved grain connectivity and higher Jc at low fields is obtained in Cu doped Mg11B2 samples. For un-doped samples, refined grains and more MgO impurity with proper size brought about more flux pinning centers, resulting in better Jc performance at high fields. PMID:27149682

  16. [Isolation and functional analysis of GsTIFY11b relevant to salt and alkaline stress from Glycine soja].

    PubMed

    Zhu, Dan; Bai, Xi; Zhu, Yan-Ming; Cai, Hua; Li, Yong; Ji, Wei; Chen, Chao; An, Lin; Zhu, Yi

    2012-02-01

    Using homologous cloning and RT-PCR technology, we isolated a novel TIFY family gene, GsTIFY11b, from Glycine soja L. G07256, a species that is tolerant to saline and alkaline environments. Phylogenetic analysis indicated that GsTIFY11b was closely related to AtTIFY11a with 56% similarity in amino acid identity. Protein sequence analysis showed that GsTIFY11b protein also had conserved TIFY domain, N-terminal domain, and a C-terminal Jas motif. Quantitative realtime PCR analysis indicated that the expression of GsTIFY11b was induced by both saline and alkaline stresses. Two homozygous GsTIFY11b over-expressing transgenic Arabidopsis lines were obtained. Phenotypic analysis of the transgenic and wild-type Arabidopsis indicated that over-expressing GsTIFY11b in Arabidopsis did not enhance plant tolerance to saline and alkaline stresses, whereas it showed an increased sensitivity to saline stress during seed germination and seedling development. Expression analysis of saline stress response marker genes in transgenic and wild-type plants under stress condition indicated that GsTIFY11b regulated the expression of RD29B, KIN1, and DREB. The transient expression of a GsTIFY11b-GFP fusion protein in onion epidermal cells showed that GsTIFY11b was localized to the nucleus, suggesting a role as a transcriptional regulator in the saline stress response pathway. PMID:22382065

  17. Site-selective 11B NMR studies on YbAlB4

    NASA Astrophysics Data System (ADS)

    Takano, S.; Grbic, M. S.; Kimura, K.; Yoshida, M.; Takigawa, M.; Farrell, E. C. T. O.; Kuga, K.; Nakatsuji, S.; Harima, H.

    2016-02-01

    β-YbAlB4 is a distinctive heavy fermion superconductor that exhibits unconventional quantum criticality without tuning in a strongly intermediate valence state. In this paper, we report the result of 11B NMR measurements on the single crystals of, β-YbAlB4 and α- YbAlB4, the locally isostructural polymorph of β-YbAlB4. All 11B NMR lines for both samples were successfully assigned to inequivalent crystallographic sites by comparing the experimental results and the ab-initio calculation of the electric field gradient. In both compounds, the anisotropy of the Knight shift exhibits a characteristic radial pattern, indicating approximate axial symmetry of the hybridization between the Yb-4f electrons and the conduction electrons.

  18. IFN-γ licenses CD11b(+) cells to induce progression of systemic lupus erythematosus.

    PubMed

    Shaabani, Namir; Honke, Nadine; Dolff, Sebastian; Görg, Boris; Khairnar, Vishal; Merches, Katja; Duhan, Vikas; Metzger, Sabine; Recher, Mike; Barthuber, Carmen; Hardt, Cornelia; Proksch, Peter; Häussinger, Dieter; Witzke, Oliver; Lang, Philipp A; Lang, Karl S

    2015-08-01

    Autoantibodies are a hallmark of autoimmune diseases, such as rheumatoid arthritis, autoimmune hepatitis, and systemic lupus erythematosus (SLE). High titers of anti-nuclear antibodies are used as surrogate marker for SLE, however their contribution to pathogenesis remains unclear. Using murine model of SLE and human samples, we studied the effect of immune stimulation on relapsing of SLE. Although autoantibodies bound to target cells in vivo, only additional activation of CD8(+) T cells converted this silent autoimmunity into overt disease. In mice as well as in humans CD8(+) T cells derived IFN-γ enhanced expression of Fc-receptors on CD11b(+) cells. High expression of Fc-receptors allowed CD11b(+) cells to bind to antibody covered target cells and to destroy them in vivo. We found that autoantibodies induce clinically relevant disease when adaptive immunity, specific for disease non-related antigen, is activated. PMID:26094774

  19. Fission fragment angular distributions for 11B and 19F+238U systems

    NASA Astrophysics Data System (ADS)

    Karnik, A.; Kailas, S.; Chatterjee, A.; Navin, A.; Shrivastava, A.; Singh, P.; Samant, M. S.

    1995-12-01

    The fission fragment angular distributions were measured at energies above the fusion barrier, for the systems 11B and 19F + 238U. An analysis of the present data along with those already available for the systems 6,7Li, 12C, and 16O + 238U was made in terms of the saddle-point statistical model. While the anisotropies were ``normal'' for 6,7Li, 11B, 12C+238U systems, the ones for 16O and 19F+238U systems were found to be ``anomalous.'' The entrance channel mass asymmetry dependence of the anisotropies as observed here is consistent with the expectations of preequilibrium fission dynamics. This result emphasizes the importance of preequilibrium fission in heavy-ion induced fusion-fission reactions.

  20. New direct 11B NMR-based analysis of organoboranes through their potassium borohydrides.

    PubMed

    Medina, Jesus R; Cruz, Gabriel; Cabrera, Carlos R; Soderquist, John A

    2003-06-13

    Representative organoborane mixtures were quantitatively converted to their borohydrides through their reaction with activated KH (KH), permitting their detailed analysis by (11)B NMR. Through the treatment of commercial KH with a THF solution of lithium aluminum hydride (LAH), a dramatic change in the surface morphology results as revealed by scanning electron microscopy (SEM). Energy dispersed spectroscopy (EDS) was employed to reveal that the LAH treatment deposits a significant amount of an unknown aluminum-containing species on the surface of the KH, which imparts a unique reactivity to the KH. Even highly hindered organoboranes are quantitatively converted to their borohydrides by replacing electronegative groups (e.g., OR, halogen) with hydrogen, retaining only the carbon ligation. Through this simple KH treatment, complex organoborane reaction mixtures are converted to the corresponding borohydrides whose (11)B NMR spectra normally exhibit resolved signals for the individual species present. The integration of these signals provides quantitative information on the relative amounts of each component of the mixture. New generalities for the effect of alpha-, beta-, and gamma-substituents have also been determined that provide a new, simple technique for the determination of the isomeric distribution in organoborane mixtures resulting from common organoborane processes (e.g., hydroboration). Moreover, the (1)H-coupled (11)B NMR spectra of these mixtures reveal the extent of alkylation for each species present. Representative organoboranes were examined by this new technique permitting a simple and convenient quantitative analysis of the regio- and diastereomeric composition of a variety of asymmetric organoborane processes. Previously unknown details of pinene-based hydroborations and reductions are revealed for the first time employing the KH (11)B NMR technique. PMID:12790565

  1. A three-body model of the {sup 11}B nucleus

    SciTech Connect

    Dubovichenko, S. B.

    2011-08-15

    The binding energy and the rms charge and mass radii have been calculated in terms of the single-channel three-body {sup 4}He{sup 4}He{sup 3}H model of the {sup 11}B nucleus with an expansion of the three-body wave function in a nonorthogonal Gaussian basis. Parameters of the wave function are presented and convergence of the three-body energy depending on the number of expansion terms is demonstrated.

  2. Conditional Deletion of Hsd11b2 in the Brain Causes Salt Appetite and Hypertension

    PubMed Central

    Evans, Louise C.; Ivy, Jessica R.; Wyrwoll, Caitlin; McNairn, Julie A.; Menzies, Robert I.; Christensen, Thorbjørn H.; Al-Dujaili, Emad A.S.; Kenyon, Christopher J.; Mullins, John J.; Seckl, Jonathan R.; Holmes, Megan C.

    2016-01-01

    Background— The hypertensive syndrome of Apparent Mineralocorticoid Excess is caused by loss-of-function mutations in the gene encoding 11β-hydroxysteroid dehydrogenase type 2 (11βHSD2), allowing inappropriate activation of the mineralocorticoid receptor by endogenous glucocorticoid. Hypertension is attributed to sodium retention in the distal nephron, but 11βHSD2 is also expressed in the brain. However, the central contribution to Apparent Mineralocorticoid Excess and other hypertensive states is often overlooked and is unresolved. We therefore used a Cre-Lox strategy to generate 11βHSD2 brain-specific knockout (Hsd11b2.BKO) mice, measuring blood pressure and salt appetite in adults. Methods and Results— Basal blood pressure, electrolytes, and circulating corticosteroids were unaffected in Hsd11b2.BKO mice. When offered saline to drink, Hsd11b2.BKO mice consumed 3 times more sodium than controls and became hypertensive. Salt appetite was inhibited by spironolactone. Control mice fed the same daily sodium intake remained normotensive, showing the intrinsic salt resistance of the background strain. Dexamethasone suppressed endogenous glucocorticoid and abolished the salt-induced blood pressure differential between genotypes. Salt sensitivity in Hsd11b2.BKO mice was not caused by impaired renal sodium excretion or volume expansion; pressor responses to phenylephrine were enhanced and baroreflexes impaired in these animals. Conclusions— Reduced 11βHSD2 activity in the brain does not intrinsically cause hypertension, but it promotes a hunger for salt and a transition from salt resistance to salt sensitivity. Our data suggest that 11βHSD2-positive neurons integrate salt appetite and the blood pressure response to dietary sodium through a mineralocorticoid receptor–dependent pathway. Therefore, central mineralocorticoid receptor antagonism could increase compliance to low-sodium regimens and help blood pressure management in cardiovascular disease. PMID

  3. Detection of the Secondary Eclipse of Exoplanet HAT P-11b

    NASA Technical Reports Server (NTRS)

    Barry, R. K.; Deming, L. D.; Bakos, G.; Harrington, J.; Madhusudhan, N.; Noyes, R.; Seager, S.

    2010-01-01

    We have successfully conducted secondary eclipse observations of exoplanet HAT-P-11b using the Spitzer Space Telescope. HAT-P-11b was, until very recently, the smallest transiting extrasolar planet yet found and one of only two known exo-Neptunes. We observed the system at 3.6 microns for a period of 22 hours centered on the anticipated secondary eclipse time, to detect the eclipse and determine its phase. Having detected the secondary eclipse, we are at present making a more focused series of observations in both the 3.6 and 4.5 micron bands to fully characterize it. HAT-P-11b has a period of 4.8878 days, radius of 0.422 RJ, mass of 0.081 MJ and semi-major axis 0.053 AU. Measurements of the secondary eclipse will serve to clarify two key issues; 1) the planetary brightness temperature and the nature of its atmosphere, and 2) the eccentricity of its orbit, with implications for its dynamical evolution. A precise determination of the orbit phase for the secondary eclipse will also be of great utility for Kepler observations of this system at visible wavelengths.

  4. Wireless Coexistence and EMC of Bluetooth and 802.11b Devices in Controlled Laboratory Settings.

    PubMed

    Seidman, Seth; Kainz, Wolfgang; Ruggera, Paul; Mendoza, Gonzalo

    2011-01-01

    This paper presents experimental testing that has been performed on wireless communication devices as victims of electromagnetic interference (EMI). Wireless victims included universal serial bus (USB) network adapters and personal digital assistants (PDAs) equipped with IEEE 802.11b and Bluetooth technologies. The experimental data in this paper was gathered in an anechoic chamber and a gigahertz transverse electromagnetic (GTEM) cell to ensure reliable and repeatable results. This testing includes: Electromagnetic compatibility (EMC) testing performed in accordance with IEC 60601-1-2, an in-band sweep of EMC testing, and coexistence testing. The tests in this study show that a Bluetooth communication was able to coexist with other Bluetooth devices with no decrease in throughput and no communication breakdowns. However, testing revealed a significant decrease in throughput and increase in communication breakdowns when an 802.11b source is near an 802.11b victim. In a hospital setting decreased throughput and communication breakdowns can cause wireless medical devices to fail. It is therefore vital to have an understanding of the effect EMI can have on wireless communication devices. PMID:22043254

  5. Inhibition of 11b-HSD1 by tetracyclic triterpenoids from Euphorbia kansui.

    PubMed

    Guo, Jie; Zhou, Li-Yan; He, Hong-Ping; Leng, Ying; Yang, Zhen; Hao, Xiao-Jiang

    2012-01-01

    The roots of Euphorbia kansui are considered an important traditional folk medicine. In this study the ethanol extracts of E. kansui were investigated. A new tetracyclic triterpenoid, euphane-3b,20-dihydroxy-24-ene, in addition to five known triterpenoids with euphane skeletons were isolated. Their structures were elucidated on the basis of physical and spectral techniques (1D-, 2D-NMR and MS, respectively). Furthermore, these compounds 1-6 exhibited strong inhibitory activity against human 11b-hydroxysteroid dehydrogenase type 1 (11b-HSD1), with IC(50) values of 34.86 nM, 1.115 mM, 16.08 nM, 2.815 nM, 26.47 nM, 15.99 nM, and 41.86 nM, respectively. The docking results show that the ring part of compounds can insert into the hydrophobic core of h11b-HSD1 and the alkane chain orientates toward the outside. The results presented herein provide a scientific explanation for the usage of the E. kansui in clinical treatment of diabetes. PMID:23047483

  6. Linking CD11b+ Dendritic Cells and Natural Killer T Cells to Plaque Inflammation in Atherosclerosis

    PubMed Central

    Rombouts, Miche; Ammi, Rachid; Van Brussel, Ilse; Roth, Lynn; De Winter, Benedicte Y.; Vercauteren, Sven R.; Hendriks, Jeroen M. H.; Lauwers, Patrick; Van Schil, Paul E.; De Meyer, Guido R. Y.; Fransen, Erik; Cools, Nathalie; Schrijvers, Dorien M.

    2016-01-01

    Atherosclerosis remains the leading cause of death and disability in our Western society. To investigate whether the dynamics of leukocyte (sub)populations could be predictive for plaque inflammation during atherosclerosis, we analyzed innate and adaptive immune cell distributions in blood, plaques, and lymphoid tissue reservoirs in apolipoprotein E-deficient (ApoE−/−) mice and in blood and plaques from patients undergoing endarterectomy. Firstly, there was predominance of the CD11b+ conventional dendritic cell (cDC) subset in the plaque. Secondly, a strong inverse correlation was observed between CD11b+ cDC or natural killer T (NKT) cells in blood and markers of inflammation in the plaque (including CD3, T-bet, CCR5, and CCR7). This indicates that circulating CD11b+ cDC and NKT cells show great potential to reflect the inflammatory status in the atherosclerotic plaque. Our results suggest that distinct changes in inflammatory cell dynamics may carry biomarker potential reflecting atherosclerotic lesion progression. This not only is crucial for a better understanding of the immunopathogenesis but also bares therapeutic potential, since immune cell-based therapies are emerging as a promising novel strategy in the battle against atherosclerosis and its associated comorbidities. The cDC-NKT cell interaction in atherosclerosis serves as a good candidate for future investigations. PMID:27051078

  7. Wireless Coexistence and EMC of Bluetooth and 802.11b Devices in Controlled Laboratory Settings

    PubMed Central

    Seidman, Seth; Kainz, Wolfgang; Ruggera, Paul; Mendoza, Gonzalo

    2011-01-01

    This paper presents experimental testing that has been performed on wireless communication devices as victims of electromagnetic interference (EMI). Wireless victims included universal serial bus (USB) network adapters and personal digital assistants (PDAs) equipped with IEEE 802.11b and Bluetooth technologies. The experimental data in this paper was gathered in an anechoic chamber and a gigahertz transverse electromagnetic (GTEM) cell to ensure reliable and repeatable results. This testing includes: Electromagnetic compatibility (EMC) testing performed in accordance with IEC 60601-1-2, an in-band sweep of EMC testing, and coexistence testing. The tests in this study show that a Bluetooth communication was able to coexist with other Bluetooth devices with no decrease in throughput and no communication breakdowns. However, testing revealed a significant decrease in throughput and increase in communication breakdowns when an 802.11b source is near an 802.11b victim. In a hospital setting decreased throughput and communication breakdowns can cause wireless medical devices to fail. It is therefore vital to have an understanding of the effect EMI can have on wireless communication devices. PMID:22043254

  8. High sensitivity boron quantification in bulk silicon using the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be nuclear reaction

    SciTech Connect

    Moro, Marcos V.; Silva, Tiago F. da; Added, Nemitala; Rizutto, Marcia A.; Tabacniks, Manfredo H.; Neira, John B.; Neto, Joao B. F.

    2013-05-06

    There is a great need to quantify sub-ppm levels of boron in bulk silicon. There are several methods to analyze B in Si: Nuclear Reaction Analysis using the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be reaction exhibits a quantification limit of some hundreds ppm of B in Si. Heavy Ion Elastic Recoil Detection Analysis offers a detection limit of 5 to 10 at. ppm. Secondary Ion Mass Spectrometry is the method of choice of the semiconductor industry for the analysis of B in Si. This work verifies the use of NRA to quantify B in Si, and the corresponding detection limits. Proton beam with 1.6 up to 2.6 MeV was used to obtain the cross-section of the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be nuclear reaction at 170 Degree-Sign scattering angle. The results show good agreementwith literature indicating that the quantification of boron in silicon can be achieved at 100 ppm level (high sensitivity) at LAMFI-IFUSP with about 16% uncertainty. Increasing the detection solid angle and the collected beam charge, can reduce the detection limit to less than 100 ppm meeting present technological needs.

  9. On the Magic Square and Inverse

    ERIC Educational Resources Information Center

    Elzaidi, S. M.

    2005-01-01

    In this note, we give a method for finding the inverse of a three by three magic square matrix without using the usual methods for finding the inverse of a matrix. Also we give a method for finding the inverse of a three by three magic square matrix whose entries are also matrices. By using these ideas, we can construct large matrices whose…

  10. The Role of Statistics in Management Magic

    ERIC Educational Resources Information Center

    Stivers, Richard

    2004-01-01

    Technology and magic both represent the human will to power - to dominate nature and ultimately humans. In a technological civilization, magic imitates technology. Modern management often entails psychological techniques (the human relations approach) and organizational techniques (the scientific approach). The heart of the latter is statistical…

  11. Algebra Magic Tricks: Algecadabra! Volume 1.

    ERIC Educational Resources Information Center

    Edwards, Ronald

    This resource book contains 20 magic tricks based on the properties of whole numbers that are intended to spark the interest and imagination of students. Following each activity, students are asked to write about their discoveries and to create their own magic tricks. A matrix of skills for all the activities and lists of the materials required…

  12. Algebra Magic Tricks: Algecadabra! Volume 2.

    ERIC Educational Resources Information Center

    Edwards, Ronald

    This resource book contains 15 magic tricks based on the properties of whole numbers that are intended to spark the interest and imagination of students. Following each activity, students are asked to write about their discoveries and to create their own magic tricks. A matrix of skills for all the activities and lists of the materials required…

  13. Using Magic Words to Teach Social Studies.

    ERIC Educational Resources Information Center

    Barton, Keith C.

    1996-01-01

    Presents a lesson plan that uses subordinating conjunctions and prepositions as "magic words." After a lesson or unit of study, students write content specific sentences using the "magic" conjunctions and prepositions. This activity serves as a unit review, helps with concept formation, and increases writing skills. (MJP)

  14. 17 CFR 274.11b - Form N-3, registration statement of separate accounts organized as management investment companies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 17 Commodity and Securities Exchanges 3 2013-04-01 2013-04-01 false Form N-3, registration statement of separate accounts organized as management investment companies. 274.11b Section 274.11b Commodity and Securities Exchanges SECURITIES AND EXCHANGE COMMISSION (CONTINUED) FORMS PRESCRIBED UNDER THE INVESTMENT COMPANY ACT OF 1940...

  15. Effect of Bcl11b genotypes and {gamma}-radiation on the development of mouse thymic lymphomas

    SciTech Connect

    Yoshikai, Yoshihiro; Sato, Toshihiro; Morita, Shinichi; Kohara, Yuki; Takagi, Ritsuo; Mishima, Yukio; Kominami, Ryo

    2008-08-22

    Bcl11b is a haploinsufficient tumor suppressor gene and expressed in many tissues such as thymus, brain and skin. Irradiated Bcl11b{sup +/-} heterozygous mice mostly develop thymic lymphomas, but the preference of Bcl11b inactivation for thymic lymphomas remains to be addressed. We produced Bcl11b{sup +/-} heterozygous and Bcl11b wild-type mice of p53{sup +/-} background and compared their incidence of {gamma}-ray induced thymic lymphomas. Majority of the tumors in p53{sup +/-} mice were skin tumors, and only 5 (36%) of the 14 tumors were thymic lymphomas. In contrast, Bcl11b{sup +/-}p53{sup +/-} doubly heterozygous mice developed thymic lymphomas at the frequency of 27 (79%) of the 34 tumors developed (P = 0.008). This indicates the preference of Bcl11b impairment for thymic lymphoma development. We also analyzed loss of the wild-type alleles in the 27 lymphomas, a predicted consequence given by {gamma}-irradiation. However, the loss frequency was low, only six (22%) for Bcl11b and five (19%) for p53. The frequencies did not differ from those of spontaneously developed thymic lymphomas in the doubly heterozygous mice, though the latency of lymphoma development markedly differed between them. This suggests that the main contribution of irradiation at least in those mice is not for the tumor initiation by inducing allelic losses but probably for the promotion of thymic lymphoma development.

  16. The magic of social thought.

    PubMed

    Kalampalikis, Nikos

    2014-10-01

    Studying social thinking provides a promising field of investigation for the constitution of common knowledge in communication and action of historically and culturally situated groups. Its genealogy helps the understanding of the symbolic efficacy of social practices and their own operating collective logic. The English translation of a short version of Serge Moscovici's article on the new magical thinking allows a wider audience to gain access, for the first time, to a text that perfectly illustrates the currentness and relevance of the social psychology of knowledge. PMID:25288162

  17. On the Power of Reusable Magic States

    NASA Astrophysics Data System (ADS)

    Anderson, Jonas

    2013-03-01

    In this paper we study reusable magic states. These states are a subset of the standard magic states. Once distilled, reusable magic states can be used repeatedly to apply some unitary U. Given this property, reusable magic states have the potential to greatly lower qubit and gate overhead in fault-tolerant quantum computation. While these states have some potential for lowering overhead, we provide a strong argument for their limited computational power. Specifically, we show that if reusable magic states can be used to apply non-Clifford unitaries, then we can exploit them to efficiently simulate poly-sized quantum circuits on a classical computer. JTA was supported in part by the National Science Foundation through Grant 0829944. JTA was supported in part by the Laboratory Directed Research and Development program at Sandia National Laboratories.

  18. CD11b+Ly6G- myeloid cells mediate mechanical inflammatory pain hypersensitivity.

    PubMed

    Ghasemlou, Nader; Chiu, Isaac M; Julien, Jean-Pierre; Woolf, Clifford J

    2015-12-01

    Pain hypersensitivity at the site of inflammation as a result of chronic immune diseases, pathogenic infection, and tissue injury is a common medical condition. However, the specific contributions of the innate and adaptive immune system to the generation of pain during inflammation have not been systematically elucidated. We therefore set out to characterize the cellular and molecular immune response in two widely used preclinical models of inflammatory pain: (i) intraplantar injection of complete Freund's adjuvant (CFA) as a model of adjuvant- and pathogen-based inflammation and (ii) a plantar incisional wound as a model of tissue injury-based inflammation. Our findings reveal differences in temporal patterns of immune cell recruitment and activation states, cytokine production, and pain in these two models, with CFA causing a nonresolving granulomatous inflammatory response whereas tissue incision induced resolving immune and pain responses. These findings highlight the significant differences and potential clinical relevance of the incisional wound model compared with the CFA model. By using various cell-depletion strategies, we find that, whereas lymphocyte antigen 6 complex locus G (Ly)6G(+)CD11b(+) neutrophils and T-cell receptor (TCR) β(+) T cells do not contribute to the development of thermal or mechanical pain hypersensitivity in either model, proliferating CD11b(+)Ly6G(-) myeloid cells were necessary for mechanical hypersensitivity during incisional pain, and, to a lesser extent, CFA-induced inflammation. However, inflammatory (CCR2(+)Ly6C(hi)) monocytes were not responsible for these effects. The finding that a population of proliferating CD11b(+)Ly6G(-) myeloid cells contribute to mechanical inflammatory pain provides a potential cellular target for its treatment in wound inflammation. PMID:26598697

  19. CD11b+Ly6G− myeloid cells mediate mechanical inflammatory pain hypersensitivity

    PubMed Central

    Ghasemlou, Nader; Chiu, Isaac M.; Julien, Jean-Pierre; Woolf, Clifford J.

    2015-01-01

    Pain hypersensitivity at the site of inflammation as a result of chronic immune diseases, pathogenic infection, and tissue injury is a common medical condition. However, the specific contributions of the innate and adaptive immune system to the generation of pain during inflammation have not been systematically elucidated. We therefore set out to characterize the cellular and molecular immune response in two widely used preclinical models of inflammatory pain: (i) intraplantar injection of complete Freund’s adjuvant (CFA) as a model of adjuvant- and pathogen-based inflammation and (ii) a plantar incisional wound as a model of tissue injury-based inflammation. Our findings reveal differences in temporal patterns of immune cell recruitment and activation states, cytokine production, and pain in these two models, with CFA causing a nonresolving granulomatous inflammatory response whereas tissue incision induced resolving immune and pain responses. These findings highlight the significant differences and potential clinical relevance of the incisional wound model compared with the CFA model. By using various cell-depletion strategies, we find that, whereas lymphocyte antigen 6 complex locus G (Ly)6G+CD11b+ neutrophils and T-cell receptor (TCR) β+ T cells do not contribute to the development of thermal or mechanical pain hypersensitivity in either model, proliferating CD11b+Ly6G− myeloid cells were necessary for mechanical hypersensitivity during incisional pain, and, to a lesser extent, CFA-induced inflammation. However, inflammatory (CCR2+Ly6Chi) monocytes were not responsible for these effects. The finding that a population of proliferating CD11b+Ly6G− myeloid cells contribute to mechanical inflammatory pain provides a potential cellular target for its treatment in wound inflammation. PMID:26598697

  20. Structure-function integrity of the adult hippocampus depends on the transcription factor Bcl11b/Ctip2.

    PubMed

    Simon, R; Baumann, L; Fischer, J; Seigfried, F A; De Bruyckere, E; Liu, P; Jenkins, N A; Copeland, N G; Schwegler, H; Britsch, S

    2016-04-01

    The dentate gyrus is one of the only two brain regions where adult neurogenesis occurs. Throughout life, cells of the neuronal stem cell niche undergo proliferation, differentiation and integration into the hippocampal neural circuitry. Ongoing adult neurogenesis is a prerequisite for the maintenance of adult hippocampal functionality. Bcl11b, a zinc finger transcription factor, is expressed by postmitotic granule cells in the developing as well as adult dentate gyrus. We previously showed a critical role of Bcl11b for hippocampal development. Whether Bcl11b is also required for adult hippocampal functions has not been investigated. Using a tetracycline-dependent inducible mouse model under the control of the forebrain-specific CaMKIIα promoter, we show here that the adult expression of Bcl11b is essential for survival, differentiation and functional integration of adult-born granule cell neurons. In addition, Bcl11b is required for survival of pre-existing mature neurons. Consequently, loss of Bcl11b expression selectively in the adult hippocampus results in impaired spatial working memory. Together, our data uncover for the first time a specific role of Bcl11b in adult hippocampal neurogenesis and function. PMID:26915960

  1. CD11b regulates obesity-induced insulin resistance via limiting alternative activation and proliferation of adipose tissue macrophages

    PubMed Central

    Zheng, Chunxing; Yang, Qian; Xu, Chunliang; Cao, Jianchang; Jiang, Menghui; Chen, Qing; Cao, Gang; Han, Yanyan; Li, Fengying; Cao, Wei; Zhang, Liying; Zhang, Li; Shi, Yufang; Wang, Ying

    2015-01-01

    Obesity-associated inflammation is accompanied by the accumulation of adipose tissue macrophages (ATMs), which is believed to predispose obese individuals to insulin resistance. CD11b (integrin αM) is highly expressed on monocytes and macrophages and is critical for their migration and function. We found here that high-fat diet–induced insulin resistance was significantly reduced in CD11b-deficient mice. Interestingly, the recruitment of monocytes to adipose tissue is impaired when CD11b is deficient, although the cellularity of ATMs in CD11b-deficient mice is higher than that in wild-type mice. We further found that the increase in ATMs is caused mainly by their vigorous proliferation in the absence of CD11b. Moreover, the proliferation and alternative activation of ATMs are regulated by the IL-4/STAT6 axis, which is inhibited by CD11b through the activity of phosphatase SHP-1. Thus, CD11b plays a critical role in obesity-induced insulin resistance by limiting the proliferation and alternative activation of ATMs. PMID:26669445

  2. Structure‐function integrity of the adult hippocampus depends on the transcription factor Bcl11b/Ctip2

    PubMed Central

    Simon, R.; Baumann, L.; Fischer, J.; Seigfried, F. A.; De Bruyckere, E.; Liu, P.; Jenkins, N. A.; Copeland, N. G.; Schwegler, H.

    2016-01-01

    The dentate gyrus is one of the only two brain regions where adult neurogenesis occurs. Throughout life, cells of the neuronal stem cell niche undergo proliferation, differentiation and integration into the hippocampal neural circuitry. Ongoing adult neurogenesis is a prerequisite for the maintenance of adult hippocampal functionality. Bcl11b, a zinc finger transcription factor, is expressed by postmitotic granule cells in the developing as well as adult dentate gyrus. We previously showed a critical role of Bcl11b for hippocampal development. Whether Bcl11b is also required for adult hippocampal functions has not been investigated. Using a tetracycline‐dependent inducible mouse model under the control of the forebrain‐specific CaMKIIα promoter, we show here that the adult expression of Bcl11b is essential for survival, differentiation and functional integration of adult‐born granule cell neurons. In addition, Bcl11b is required for survival of pre‐existing mature neurons. Consequently, loss of Bcl11b expression selectively in the adult hippocampus results in impaired spatial working memory. Together, our data uncover for the first time a specific role of Bcl11b in adult hippocampal neurogenesis and function. PMID:26915960

  3. Integrin CD11b attenuates colitis by strengthening Src-Akt pathway to polarize anti-inflammatory IL-10 expression.

    PubMed

    Hu, Xiang; Han, Chaofeng; Jin, Jing; Qin, Kewei; Zhang, Hua; Li, Tianliang; Li, Nan; Cao, Xuetao

    2016-01-01

    Interleukin-10 (IL-10) plays a central role in regulation of intestinal mucosal homeostasis and prevention of inflammatory bowel disease (IBD). We previously reported that CD11b(hi) regulatory dendritic cells (DCs) can produce more IL-10, and CD11b can negatively regulate Toll-like receptors (TLRs)-induced inflammatory responses in macrophages. However whether CD11b and its signaling can control autoimmunity via IL-10 production remains unclear. Here we found that CD11b deficient (Itgam(-/-)) mice were more susceptible to dextran sulfate sodium (DSS)-induced colitis, with more tumor necrosis factor α (TNF-α) while less IL-10 production. CD11b inhibited nuclear factor-kappa B (NF-κB) while promoted activator protein 1 (AP-1) activation through activating sarcoma oncogene (Src), leading to decreased TNF-α while increased IL-10 production. Src interacted with and promoted c-casitas B lineage lymphoma proto-oncogene (c-Cbl)-mediated degradation of the inhibitory subunit p85 of phosphatidylinositol 3-kinase (PI3K). Importantly, Src inhibitor dasatinib aggravated DSS-induced colitis by decreasing IL-10 while increasing TNF-α in vivo. Therefore, CD11b promotes IL-10 production by activating Src-Akt signal pathway. An axis of CD11b-Src pathway is important in balancing homeostasis of TLR-induced pro-inflammatory and anti-inflammatory responses. PMID:27188220

  4. Rab11b Regulates the Apical Recycling of the Cystic Fibrosis Transmembrane Conductance Regulator in Polarized Intestinal Epithelial Cells

    PubMed Central

    Silvis, Mark R.; Bertrand, Carol A.; Ameen, Nadia; Golin-Bisello, Franca; Butterworth, Michael B.; Bradbury, Neil A.

    2009-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP/PKA-activated anion channel, undergoes efficient apical recycling in polarized epithelia. The regulatory mechanisms underlying CFTR recycling are understood poorly, yet this process is required for proper channel copy number at the apical membrane, and it is defective in the common CFTR mutant, ΔF508. Herein, we investigated the function of Rab11 isoforms in regulating CFTR trafficking in T84 cells, a colonic epithelial line that expresses CFTR endogenously. Western blotting of immunoisolated Rab11a or Rab11b vesicles revealed localization of endogenous CFTR within both compartments. CFTR function assays performed on T84 cells expressing the Rab11a or Rab11b GDP-locked S25N mutants demonstrated that only the Rab11b mutant inhibited 80% of the cAMP-activated halide efflux and that only the constitutively active Rab11b-Q70L increased the rate constant for stimulated halide efflux. Similarly, RNAi knockdown of Rab11b, but not Rab11a, reduced by 50% the CFTR-mediated anion conductance response. In polarized T84 monolayers, adenoviral expression of Rab11b-S25N resulted in a 70% inhibition of forskolin-stimulated transepithelial anion secretion and a 50% decrease in apical membrane CFTR as assessed by cell surface biotinylation. Biotin protection assays revealed a robust inhibition of CFTR recycling in polarized T84 cells expressing Rab11b-S25N, demonstrating the selective requirement for the Rab11b isoform. This is the first report detailing apical CFTR recycling in a native expression system and to demonstrate that Rab11b regulates apical recycling in polarized epithelial cells. PMID:19244346

  5. A solid-state (11)b NMR and computational study of boron electric field gradient and chemical shift tensors in boronic acids and boronic esters.

    PubMed

    Weiss, Joseph W E; Bryce, David L

    2010-04-22

    The results of a solid-state (11)B NMR study of a series of 10 boronic acids and boronic esters with aromatic substituents are reported. Boron-11 electric field gradient (EFG) and chemical shift (CS) tensors obtained from analyses of spectra acquired in magnetic fields of 9.4 and 21.1 T are demonstrated to be useful for gaining insight into the molecular and electronic structure about the boron nucleus. Data collected at 21.1 T clearly show the effects of chemical shift anisotropy (CSA), with tensor spans (Omega) on the order of 10-40 ppm. Signal enhancements of up to 2.95 were achieved with a DFS-modified QCPMG pulse sequence. To understand the relationship between the measured tensors and the local structure better, calculations of the (11)B EFG and magnetic shielding tensors for these compounds were conducted. The best agreement was found between experimental results and those obtained from GGA revPBE DFT calculations. A positive correlation was found between Omega and the dihedral angle (phi(CCBO)), which describes the orientation of the boronic acid/ester functional group relative to an aromatic system bound to boron. The small boron CSA is discussed in terms of paramagnetic shielding contributions as well as diamagnetic shielding contributions. Although there is a region of overlap, both Omega and the (11)B quadrupolar coupling constants tend to be larger for boronic acids than for the esters. We conclude that the span is generally the most characteristic boron NMR parameter of the molecular and electronic environment for boronic acids and esters, and show that the values result from a delicate interplay of several competing factors, including hydrogen bonding, the value of phi(CCBO), and the electron-donating or withdrawing substituents bound to the aromatic ring. PMID:20337440

  6. Magic wavelengths for terahertz clock transitions

    SciTech Connect

    Zhou Xiaoji; Xu Xia; Chen Xuzong; Chen Jingbiao

    2010-01-15

    Magic wavelengths for laser trapping of boson isotopes of alkaline-earth metal atoms Sr, Ca, and Mg are investigated while considering terahertz clock transitions between the {sup 3}P{sub 0}, {sup 3}P{sub 1}, and {sup 3}P{sub 2} metastable triplet states. Our calculation shows that magic wavelengths for laser trapping do exist. This result is important because those metastable states have already been used to make accurate clocks in the terahertz frequency domain. Detailed discussions for magic wavelengths for terahertz clock transitions are given in this article.

  7. Implications of the Secondary Eclipse of Exoplanet HAT-P-11b

    NASA Technical Reports Server (NTRS)

    Barry, Richard K.; Deming, L. D.; Bakos, G.; Harrington, J.; Madhusudhan, N.; Noyes, R.; Seager, S.

    2010-01-01

    We observed exoplanet HAT-P-11b and have successfully detected its secondary eclipse. We conducted observations using the Spitzer Space Telescope in the post-cryo mission at 3.6 microns for a period of 22 hours centered on the anticipated secondary eclipse time, to detect the eclipse and determine its phase. Having detected the secondary eclipse, we are at present making a more focused series of observations in both the 3.6 and 4.5 micron bands to fully characterize it. HAT-P-11b is one of only two known exo-Neptunes and has a period of 4.8878 days, radius of 0.422 RJ, mass of 0.081 MJ and semi-major axis 0.053 AU. Measurements of the secondary eclipse will serve to clarify two key issues; 1) the planetary brightness temperature and the nature of its atmosphere, and 2) the eccentricity of its orbit, with implications for its dynamical evolution. We discuss implications of these observations.

  8. Rare Mechanisms of Stopped Pion Absorption by 10,11B Nuclei

    NASA Astrophysics Data System (ADS)

    Chernyshev, B. A.; Gurov, Yu. B.; Korotkova, L. Yu.; Lapushkin, S. V.; Pritula, R. V.

    2015-06-01

    Correlation measurements of the stopped π--meson absorption reactions 10B(π-, dt)X and 11B(π-, tt)X were carried out at low energy pion channel of LAMPF with the two-arm multilayer semiconductor spectrometer of charged particles. The analysis of twodimensional distributions (Dalitz' diagram) and the momentum distribution of the residual nucleus allowed to identify the process of pion absorption on the intranuclear lithium clusters 5,6Li and to get the evidence on the existence of the configurations 5Li + 5Heg.s and 6Li + 5Heg.s in the boron nuclei 10,11B. The levels of 8Li* isotope with the resonance parameters (Ex, C): (8.7 ± 0.2, 1.9 ± 0.4) MeV and (10.1 ± 0.3, 4.0 ± 1.3) MeV were observed for the first time. These states break up with the triton emission: 8Li* → t + 5He..

  9. Is lightning a possible source of the radio emission on HAT-P-11b?

    NASA Astrophysics Data System (ADS)

    Hodosán, G.; Rimmer, P. B.; Helling, Ch.

    2016-09-01

    Lightning induced radio emission has been observed on Solar system planets. There have been many attempts to observe exoplanets in the radio wavelength, however, no unequivocal detection has been reported. Lecavelier des Etangs et al. carried out radio transit observations of the exoplanet HAT-P-11b, and suggested that a small part of the radio flux can be attributed to the planet. Here, we assume that this signal is real, and study if this radio emission could be caused by lightning with similar energetic properties like in the Solar system. We find that a lightning storm with 3.8 × 106 times larger flash densities than the Earth-storms with the largest lightning activity is needed to produce the observed signal from HAT-P-11b. The optical emission of such thunderstorm would be comparable to that of the host star. We show that HCN produced by lightning chemistry is observable 2-3 yr after the storm, which produces signatures in the L (3.0-4.0 μm) and N (7.5-14.5 μm) infrared bands. We conclude that it is unlikely that the observed radio signal was produced by lightning, however, future, combined radio and infrared observations may lead to lightning detection on planets outside the Solar system.

  10. Lightning as a possible source of the radio emission on HAT-P-11b

    NASA Astrophysics Data System (ADS)

    Hodosán, G.; Rimmer, P. B.; Helling, Ch.

    2016-04-01

    Lightning induced radio emission has been observed on Solar System planets. There have been many attempts to observe exoplanets in the radio wavelength, however, no unequivocal detection has been reported. Lecavelier des Etangs et al. (2013, A&A, 552, A65) carried out radio transit observations of the exoplanet HAT-P-11b, and suggested that a small part of the radio flux can be attributed to the planet. In the current letter, we assume that this signal is real, and study if this radio emission could be caused by lightning in the atmosphere of the planet. We find that a lightning storm with 530 times larger flash densities than the Earth-storms with the largest lightning activity is needed to produce the observed signal from HAT-P-11b. The optical counterpart would nevertheless be undetectable with current technology. We show that HCN produced by lightning chemistry of such thunderstorms is observable 2-3 years after the storm, which produces signatures in the L (3.0μm - 4.0μm) and N (7.5μm - 14.5μm) infrared bands. We conclude that future, combined radio and infrared observations may lead to lightning detection on planets outside the Solar System.

  11. Measurements of the {sup 25}Mg({sup 11}B,{sup 12}C){sup 24}Na and {sup 25}Mg({sup 11}B,{sup 10}Be){sup 26}Al proton transfer reactions

    SciTech Connect

    Faria, P. N. de; Lichtenthaeler, R.; Guimaraes, V.; Lepine-Szily, A.; Benjamim, E. A.; Lima, G. F.; Moro, A. M.

    2006-08-15

    Angular distributions for the {sup 11}B+{sup 25}Mg elastic scattering, {sup 25}Mg({sup 11}B,{sup 12}C){sup 24}Na proton pickup, and {sup 25}Mg({sup 11}B,{sup 10}Be){sup 26}Al stripping reactions have been measured at E{sub {sup 11}B}=35 MeV. The angular distributions have been analyzed by the distorted-waves Born approximation calculations using the code fresco. The spectroscopic factors for the overlaps <{sup 25}Mg|{sup 26}Al>,<{sup 25}Mg|{sup 24}Na> for the ground state and excited states of {sup 26}Al and {sup 24}Na have been obtained and compared to previous measurements and shell-model calculations.

  12. The magic of relay mirrors

    NASA Astrophysics Data System (ADS)

    Duff, Edward A.; Washburn, Donald C.

    2004-09-01

    Laser weapon systems would be significantly enhanced with the addition of high altitude or space-borne relay mirrors. Such mirrors, operating alone with a directed energy source, or many in a series fashion, can be shown to effectively move the laser source to the last, so-called fighting mirror. This "magically" reduces the range to target and offers to enhance the performance of directed energy systems like the Airborne Laser and even ground-based or ship-based lasers. Recent development of high altitude airships will be shown to provide stationary positions for such relay mirrors thereby enabling many new and important applications for laser weapons. The technical challenges to achieve this capability are discussed.

  13. Insurance, risk, and magical thinking.

    PubMed

    Tykocinski, Orit E

    2008-10-01

    The possession of an insurance policy may not only affect the severity of a potential loss but also its perceived probability. Intuitively, people may feel that if they are insured nothing bad is likely to happen, but if they do not have insurance they are at greater peril. In Experiment 1, respondents who were reminded of their medical insurance felt they were less likely to suffer health problems in the future compared to people who were not reminded of their medical insurance. In Experiment 2a, participants who were unable to purchase travel insurance judged the probability of travel-related calamities higher compared to those who were insured. These results were replicated in Experiment 3a in a simulation of car accident insurance. The findings are explained in terms of intuitive magical thinking, specifically, the negative affective consequences of "tempting fate" and the sense of safety afforded by the notion of "being covered." PMID:18612038

  14. On magic numbers for super- and ultraheavy systems and hypothetical spherical double-magic nuclei

    NASA Astrophysics Data System (ADS)

    Ismail, M.; Ellithi, A. Y.; Adel, A.; Anwer, Hisham

    2016-01-01

    Based on the calculations of the shell and the residual pairing correction energies in the framework of Strutinsky's approach, we evaluated the proton and neutron magic numbers in the range 72 ≤ Z ≤ 282 and 96 ≤ N ≤ 540. New magic numbers and new islands of stability lie in a range defined by Green's formula and the two-neutrons drip lines are presented. Our calculations reproduced known spherical double-magic nuclei and present evidences on new spherical double-magic nuclei in super- and ultraheavy regions.

  15. What's Your Angle on Angles?

    ERIC Educational Resources Information Center

    Browning, Christine A.; Garza-Kling, Gina; Sundling, Elizabeth Hill

    2007-01-01

    Although the nature of the research varies, as do concepts of angle, research in general supports the supposition that angle is a complex idea, best understood from a variety of perspectives. In fact, the concept of angle tends to be threefold, consisting of: (1) the traditional, static notion of two rays meeting at a common vertex; (2) the idea…

  16. [Magical and religious healing in Byzantium].

    PubMed

    Józsa, László

    2010-01-01

    Religious and magical ways of healing have been known and practiced since the very beginning of human history. In the present article, the Byzantine philosophical, cultural, historical and "methodological" aspects of this way of healing are discussed. The article outlines the development of magic healing in Byzantium from the 4th to the 15th century. During this period magical therapy included the cult of patron saints--listed by the author--and pleading for divine intervention as well. The activity of "anargyroi" and the use of magical objects and amulets is also discussed in detail. Exorcism was also a part of religious therapy both against psychical and somatical diseases. In early Christianity, and especially in Byzantium the devil or other demons were also supposed to cause various somatical or psychical illnesses by "intrusion" or "internalisation," i.e. by possession or obsession of their victims. PMID:21661260

  17. Clinching First Place: Calculating the Magic Number.

    ERIC Educational Resources Information Center

    Quinn, Robert J.

    2000-01-01

    Describes a lesson plan in which students apply their mathematical intuition to determine win-loss possibilities of teams in a sports league and develop a formula for calculating the magic number for clinching first place. (YDS)

  18. Recent Results from the MAGIC Telescope

    SciTech Connect

    Bock, Rudolf K.

    2005-02-21

    Some recent results are shown, obtained during the commissioning period of the MAGIC telescope. They demonstrate that the telescope is now approaching a performance level suitable for physics observations.

  19. The new possibility of the fusion p + 11B chain reaction being induced by intense laser pulses

    NASA Astrophysics Data System (ADS)

    Belyaev, V. S.; Krainov, V. P.; Matafonov, A. P.; Zagreev, B. V.

    2015-09-01

    We discuss the experimental and theoretical principal schemes of a thermonuclear reactor, based on the fusion reaction p + 11B: beam collisions, fusion in degenerate plasmas, ignition at the plasma, particle acceleration by nonlinear ponderomotive forces and irradiation of the solid 11B target by a proton beam at the Coulomb explosion of hydrogen microdroplets. The fusion reaction p + 11B can be initiated by ultrashort high intensity laser pulses under conditions far from thermodynamic equilibrium. This may result in fusion products containing a small amount of neutrons and other nuclear radiation effects. It was found that the fusion reaction p + 11B produces further nuclear reactions and generates high-energy protons. The latter can support the chain reaction process. Our approach allows us to also investigate nuclear reactions in the early Universe and in stars.

  20. Flanking sequence determination and event specific detection of transgenic wheat B72-8-11b strain.

    PubMed

    Zhang, Piqiao; Xu, Junyi; Zheng, Qiuyue; Luan, Fengxia; Cao, Jijuan; Hou, Hesheng

    2013-03-01

    Exogenous fragment sequence and flanking sequence between exogenous fragment and recombinant chromosome of transgenic wheat B72-8-11b were successfully acquired through PCR amplification with cross-matched primers from exogenous genes. Newly acquired exogenous fragment covered the full-length sequence of transformed genes such as transformed plasmid and corresponding functional genes including marker uidA, promoter ubiquitin, lacZ, 1Dx5, and part of sequence of the wheat genome. A specific PCR detection method for transgenic wheat B72-8-11b strain was established on the basis of primers designed according to flanking sequence. The designed primers revealed specific amplification of 132 bp product of transgenic wheat B72-8-11b strain. This method is characteristics of high specificity, high reproducibility, rapid identification, and excellent accuracy for the identification of transgenic wheat B72-8-11b strain. PMID:23319185

  1. Tissue factor contributes to neutrophil CD11b expression in alpha-naphthylisothiocyanate-treated mice

    SciTech Connect

    Luyendyk, James P.; Flanagan, Kevin C.; Williams, C. David; Jaeschke, Hartmut; Slusser, Joyce G.; Mackman, Nigel

    2011-02-01

    Cholestatic liver injury induced by alpha-naphthylisothiocyanate (ANIT) is provoked by injury to intrahepatic bile ducts and the progression of hepatic necrosis requires the procoagulant protein tissue factor (TF) and extrahepatic cells including neutrophils. Recent studies have shown that myeloid cell TF contributes to neutrophil activation. We tested the hypothesis that myeloid cell TF contributes to neutrophil activation in ANIT-treated mice. TF activity in liver homogenates increased significantly in TF{sup flox/flox} mice treated with ANIT, but not in TF{sup flox/flox}/LysMCre mice (TF{sup {Delta}Myeloid} mice), which have reduced TF expression in monocytes/macrophages and neutrophils. Myeloid cell-specific TF deficiency did not alter expression of the chemokines KC or MIP-2 but reduced hepatic neutrophil accumulation in ANIT-treated mice at 48 h as indicated by tissue myeloperoxidase (MPO) activity. Myeloid cell TF deficiency significantly reduced CD11b expression by blood neutrophils in ANIT-treated mice, and this was associated with reduced plasma MPO protein levels, an index of neutrophil degranulation. However, myeloid cell-specific TF deficiency had no effect on ANIT-induced coagulation cascade activation. The increase in serum ALT and ALP activities in ANIT-treated mice was reduced by myeloid cell TF deficiency (p < 0.05), but the myeloid cell TF deficiency did not reduce hepatic necrosis at 48 h, as determined by histopathology and morphometry. The results suggest that myeloid cell TF contributes to neutrophil CD11b expression during cholestasis by a coagulation-independent pathway. However, the resultant reduction in neutrophil accumulation/activation is insufficient to substantially reduce ANIT hepatotoxicity, suggesting that myeloid cell TF is only one of many factors modulating hepatic necrosis during cholestasis. - Research Highlights: > Myeloid cell tissue factor contributes to liver procoagulant activity during acute cholestasis. > ANIT

  2. Integrin CD11b attenuates colitis by strengthening Src-Akt pathway to polarize anti-inflammatory IL-10 expression

    PubMed Central

    Hu, Xiang; Han, Chaofeng; Jin, Jing; Qin, Kewei; Zhang, Hua; Li, Tianliang; Li, Nan; Cao, Xuetao

    2016-01-01

    Interleukin-10 (IL-10) plays a central role in regulation of intestinal mucosal homeostasis and prevention of inflammatory bowel disease (IBD). We previously reported that CD11bhi regulatory dendritic cells (DCs) can produce more IL-10, and CD11b can negatively regulate Toll-like receptors (TLRs)-induced inflammatory responses in macrophages. However whether CD11b and its signaling can control autoimmunity via IL-10 production remains unclear. Here we found that CD11b deficient (Itgam−/−) mice were more susceptible to dextran sulfate sodium (DSS)-induced colitis, with more tumor necrosis factor α (TNF-α) while less IL-10 production. CD11b inhibited nuclear factor-kappa B (NF-κB) while promoted activator protein 1 (AP-1) activation through activating sarcoma oncogene (Src), leading to decreased TNF-α while increased IL-10 production. Src interacted with and promoted c-casitas B lineage lymphoma proto-oncogene (c-Cbl)-mediated degradation of the inhibitory subunit p85 of phosphatidylinositol 3-kinase (PI3K). Importantly, Src inhibitor dasatinib aggravated DSS-induced colitis by decreasing IL-10 while increasing TNF-α in vivo. Therefore, CD11b promotes IL-10 production by activating Src-Akt signal pathway. An axis of CD11b-Src pathway is important in balancing homeostasis of TLR-induced pro-inflammatory and anti-inflammatory responses. PMID:27188220

  3. Gr-1+CD11b+ cells are responsible for tumor promoting effect of TGF-β in breast cancer progression

    PubMed Central

    Li, Zhaoyang; Pang, Yanli; Gara, Sudheer Kumar; Achyut, B.R.; Heger, Christopher; Goldsmith, Paul K.; Lonning, Scott; Yang, Li

    2012-01-01

    One great challenge in our understanding of TGF-β cancer biology and the successful application of TGF-β targeted therapy is that TGF-β works as both a tumor suppressor and a tumor promoter. The underlying mechanisms for its functional change remain to be elucidated. Using 4T1 mammary tumor model that shares many characteristics with human breast cancer, particularly its ability to spontaneously metastasize to the lungs, we demonstrate that Gr-1+CD11b+ cells or myeloid derived suppressor cells (MDSCs) are important mediators in TGF-β regulation of mammary tumor progression. Depletion of Gr-1+CD11b+ cells diminished the anti-tumor effect of TGF-β neutralization. Two mechanisms were involved: first, treatment with TGF-β neutralization antibody (1D11) significantly decreased the number of Gr-1+CD11b+ cells in tumor tissues and premetastatic lung. This is mediated through increased Gr-1+CD11b+ cell apoptosis. In addition, 1D11 treatment significantly decreased the expression of Th2 cytokines & Arginase 1. Interestingly, the number and property of Gr-1+CD11b+ cells in peripheral blood/draining lymph nodes correlated with tumor size and metastases in response to 1D11 treatment. Our data suggest that the efficacy of TGF-β neutralization depends on the presence of Gr-1+CD11b+ cells, and these cells could be good biomarkers for TGF-β targeted therapy. PMID:22487809

  4. Working wonders? investigating insight with magic tricks.

    PubMed

    Danek, Amory H; Fraps, Thomas; von Müller, Albrecht; Grothe, Benedikt; Ollinger, Michael

    2014-02-01

    We propose a new approach to differentiate between insight and noninsight problem solving, by introducing magic tricks as problem solving domain. We argue that magic tricks are ideally suited to investigate representational change, the key mechanism that yields sudden insight into the solution of a problem, because in order to gain insight into the magicians' secret method, observers must overcome implicit constraints and thus change their problem representation. In Experiment 1, 50 participants were exposed to 34 different magic tricks, asking them to find out how the trick was accomplished. Upon solving a trick, participants indicated if they had reached the solution either with or without insight. Insight was reported in 41.1% of solutions. The new task domain revealed differences in solution accuracy, time course and solution confidence with insight solutions being more likely to be true, reached earlier, and obtaining higher confidence ratings. In Experiment 2, we explored which role self-imposed constraints actually play in magic tricks. 62 participants were presented with 12 magic tricks. One group received verbal cues, providing solution relevant information without giving the solution away. The control group received no informative cue. Experiment 2 showed that participants' constraints were suggestible to verbal cues, resulting in higher solution rates. Thus, magic tricks provide more detailed information about the differences between insightful and noninsightful problem solving, and the underlying mechanisms that are necessary to have an insight. PMID:24300080

  5. Analysis of the 11B(d,n)12C Reaction

    NASA Astrophysics Data System (ADS)

    Ridling, Nathan; Prior, Richard; Spraker, Mark; Weller, Henry; Perdue, Brent

    2006-10-01

    Studies have been performed on the ^11B(d,n)^12C reaction to measure the absolute astrophysical S factor and its energy dependence, the reaction cross section, and tensor and vector analyzing powers T20, T21, T22, and iT11. The motivation behind this research project is not only its relevance to nuclear astrophysics, but also in the reaction dynamics of (d,n) reactions at very low energies. PSD (Pulse shape discrimination) was used along with PAW (Physics Analysis Workstation) in order to extract the neutrons from the gamma-rays. Using a neutron response function fitting routine in Root, we have determined the number of neutron counts leading to the ground and first excited states of ^12C. These yields were used to construct the angular distributions of the cross section and analyzing powers. Ultimately, we will extract the reaction specific transition matrix elements.

  6. Measurement of the 8Li(α,n)11B reaction and astrophysical implications

    NASA Astrophysics Data System (ADS)

    Mizoi, Y.; Fukuda, T.; Matsuyama, Y.; Miyachi, T.; Miyatake, H.; Aoi, N.; Fukuda, N.; Notani, M.; Watanabe, Y. X.; Yoneda, K.; Ishihara, M.; Sakurai, H.; Watanabe, Y.; Yoshida, A.

    2000-12-01

    We have measured the 8Li(α,n)11B reaction directly and exclusively, and determined the total cross sections in the center-of-mass energy of 1.5-7.0 MeV, by using a new-type gas counter, multiple-sampling and tracking proportional chamber (MSTPC), and neutron counters. This experiment was performed in the condition of inverse kinematics. The 8Li beam was produced by the RIKEN projectile-fragment separator, and injected into the MSTPC filled with 4He gas, which worked as a detector gas and served as a target. The reaction cross section obtained in the present exclusive measurement is about half of the one obtained in previous inclusive measurements.

  7. No X-ray flux from M31N2008-11b

    NASA Astrophysics Data System (ADS)

    Orio, Marina; Di Mille, F.; Bianchini, A.; Ciroi, S.

    2008-12-01

    The WZ Sge-type optical transient M31N2008-11b (K. Itagaki, CBET# 1588) was observed with the Swift X-ray telescope for a total exposure time of 2872 seconds on December 12, 2008 and it was not detected, with a 3 signa upper limit to the Swift XRT PC count rate of 0.0007 cts s(-1), and an upper limit of the unabsorbed flux approximately 3x10(-14) erg/ cm^2/s. If the object had the same optical to X-ray luminosity ratio in outburst as WZ Sge, it should have been detected with an approximate Swift XRT PC count rate of 0.11 cts/s.

  8. [Boron in dental hard tissues studied by 11B(p,alpha)8Be nuclear reaction].

    PubMed

    Torrisi, L; Rapisarda, E; Cicero, G

    1989-09-01

    Boron's low atomic number and low concentration make its measurement in hard dental tissues difficult. Using nuclear reaction, the 11B(p,alpha)8Be*, enamel, dentine and radicular cement of 18 dental elements, ten healthy and eight decayed teeth, both permanent and deciduous were studied. The highest Boron concentrations were found in the two most superficial microns of the vestibular enamel in non-decayed incisors, particularly deciduous ones. Premolar and molar teeth showed lower Boron concentrations than frontal ones, decayed teeth revealed hardly any Boron. In confirmation of the prevailing exogenous contribution of this karyostatic trace element, on average, Boron concentrations were 2.5 times as high as dentine and 10 times as high as cement. PMID:2811808

  9. Antagonism of CD11b with Neutrophil Inhibitory Factor (NIF) Inhibits Vascular Lesions in Diabetic Retinopathy

    PubMed Central

    Veenstra, Alexander A.; Tang, Jie; Kern, Timothy S.

    2013-01-01

    Leukocytes and proteins that govern leukocyte adhesion to endothelial cells play a causal role in retinal abnormalities characteristic of the early stages of diabetic retinopathy, including diabetes-induced degeneration of retinal capillaries. Leukocyte integrin αmβ2 (CD11b/CD18, MAC1), a protein mediating adhesion, has been shown to mediate damage to endothelial cells by activated leukocytes in vitro. We hypothesized that Neutrophil Inhibitory Factor (NIF), a selective antagonist of integrin αmβ2, would inhibit the diabetes-induced degeneration of retinal capillaries by inhibiting the excessive interaction between leukocytes and retinal endothelial cells in diabetes. Wild type animals and transgenic animals expressing NIF were made diabetic with streptozotocin and assessed for diabetes-induced retinal vascular abnormalities and leukocyte activation. To assess if the leukocyte blocking therapy compromised the immune system, animals were challenged with bacteria. Retinal superoxide production, leukostasis and leukocyte superoxide production were increased in wild type mice diabetic for 10 weeks, as was the ability of leukocytes isolated from diabetic animals to kill retinal endothelial cells in vitro. Retinal capillary degeneration was significantly increased in wild type mice diabetic 40 weeks. In contrast, mice expressing NIF did not develop any of these abnormalities, with the exception that non-diabetic and diabetic mice expressing NIF generated greater amounts of superoxide than did similar mice not expressing NIF. Importantly, NIF did not significantly impair the ability of mice to clear an opportunistic bacterial challenge, suggesting that NIF did not compromise immune surveillance. We conclude that antagonism of CD11b (integrin αmβ2) by NIF is sufficient to inhibit early stages of diabetic retinopathy, while not compromising the basic immune response. PMID:24205223

  10. Evolution of magnetic properties and microstructure of Hf2Co11B alloys

    DOE PAGESBeta

    McGuire, Michael A.; Rios, Orlando

    2015-02-05

    Amorphous Hf2Co11B alloys produced by melt-spinning have been crystallized by annealing at 500-800 °C, and the products have been investigated using magnetization measurements, x-ray diffraction, and scanning electron microscopy. The results reveal the evolution of the phase fractions, microstructure, and magnetic properties with both annealing temperature and time. Crystallization of the phase denoted HfCo7, which is associated with the development of coercivity, occurs slowly at 500 °C. Annealing at intermediate temperatures produces mixed phase samples containing some of the HfCo7 phase with the highest values of remanent magnetization and coercivity. The equilibrium structure at 800 °C contains HfCo3B2, Hf6Co23 andmore » Co, and displays soft ferromagnetism. Maximum values for the remanent magnetization, intrinsic coercivity, and magnetic energy product among the samples are approximately 5.2 kG, 2.0 kOe, and 3.1 MGOe, respectively, which indicates that the significantly higher values observed in crystalline, melt-spun Hf2Co11B ribbons are a consequence of the non-equilibrium solidification during the melt-spinning process. Application of high magnetic fields during annealing is observed to strongly affect the microstructural evolution, which may provide access to higher performance materials in Zr/Hf-Co hard ferromagnets. The crystal structure of HfCo7 and the related Zr analogues is unknown, and without knowledge of atomic positions powder diffraction cannot distinguish among proposed unit cells and symmetries found in the literature.« less

  11. The major upgrade of the MAGIC telescopes, Part II: A performance study using observations of the Crab Nebula

    NASA Astrophysics Data System (ADS)

    Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barceló, M.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biasuzzi, B.; Biland, A.; Bitossi, M.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Cecchi, R.; Colin, P.; Colombo, E.; Contreras, J. L.; Corti, D.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; de Oña Wilhelmi, E.; Delgado Mendez, C.; Dettlaff, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Fidalgo, D.; Fink, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giavitto, G.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Haberer, W.; Hadasch, D.; Hanabata, Y.; Hayashida, M.; Herrera, J.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Illa, J. M.; Kadenius, V.; Kellermann, H.; Knoetig, M. L.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lemus, J. L.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; López-Coto, R.; López-Oramas, A.; Lorca, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Negrello, M.; Neustroev, V.; Niedzwiecki, A.; Nilsson, K.; Nishijima, K.; Noda, K.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Rügamer, S.; Saito, T.; Saito, K.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schlammer, J.; Schmidl, S.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Stamerra, A.; Steinbring, T.; Storz, J.; Strzys, M.; Takalo, L.; Takami, H.; Tavecchio, F.; Tejedor, L. A.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Tibolla, O.; Torres, D. F.; Toyama, T.; Treves, A.; Vogler, P.; Wetteskind, H.; Will, M.; Zanin, R.

    2016-01-01

    MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a series of upgrades, involving the exchange of the MAGIC-I camera and its trigger system, as well as the upgrade of the readout system of both telescopes. We use observations of the Crab Nebula taken at low and medium zenith angles to assess the key performance parameters of the MAGIC stereo system. For low zenith angle observations, the standard trigger threshold of the MAGIC telescopes is ∼ 50 GeV. The integral sensitivity for point-like sources with Crab Nebula-like spectrum above 220 GeV is (0.66 ± 0.03)% of Crab Nebula flux in 50 h of observations. The angular resolution, defined as the σ of a 2-dimensional Gaussian distribution, at those energies is ≲ 0.07°, while the energy resolution is 16%. We also re-evaluate the effect of the systematic uncertainty on the data taken with the MAGIC telescopes after the upgrade. We estimate that the systematic uncertainties can be divided in the following components: < 15% in energy scale, 11%-18% in flux normalization and ± 0.15 for the energy spectrum power-law slope.

  12. Interferon regulatory factor-8 modulates the development of tumour-induced CD11b+Gr-1+ myeloid cells.

    PubMed

    Stewart, Trina J; Greeneltch, Kristy M; Reid, Julia E; Liewehr, David J; Steinberg, Seth M; Liu, Kebin; Abrams, Scott I

    2009-09-01

    Tumour-induced myeloid-derived suppressor cells (MDSC) promote immune suppression and mediate tumour progression. However, the molecular basis for the generation of MDSC, which in mice co-express the CD11b(+) and Gr-1(+) cell surface markers remains unclear. Because CD11b(+)Gr-1(+) cells expand during progressive tumour growth, this suggests that tumour-induced events alter signalling pathways that affect normal myeloid cell development. Interferon regulatory factor-8 (IRF-8), a member of the IFN-gamma regulatory factor family, is essential for normal myelopoiesis. We therefore examined whether IRF-8 modulated tumour-induced CD11b(+)Gr-1(+) cell development or accumulation using both implantable (4T1) and transgenic (MMTV-PyMT) mouse models of mammary tumour growth. In the 4T1 model, both splenic and bone marrow-derived CD11b(+)Gr-1(+) cells of tumour-bearing mice displayed a marked reduction in IRF-8 expression compared to control populations. A causal link between IRF-8 expression and the emergence of tumour-induced CD11b(+)Gr-1(+) cells was explored in vivo using a double transgenic (dTg) mouse model designed to express transgenes for both IRF-8 and mammary carcinoma development. Despite the fact that tumour growth was unaffected, splenomegaly, as well as the frequencies and absolute numbers of CD11b(+)Gr-1(+) cells were significantly lower in dTg mice when compared with single transgenic tumour-bearing mice. Overall, these data reveal that IRF-8 plays an important role in tumour-induced development and/or accumulation of CD11b(+)Gr-1(+) cells, and establishes a molecular basis for the potential manipulation of these myeloid populations for cancer therapy. PMID:20196788

  13. Entropy and the Magic Flute

    NASA Astrophysics Data System (ADS)

    Morowitz, Harold J.

    1996-10-01

    Harold Morowitz has long been highly regarded both as an eminent scientist and as an accomplished science writer. The essays in The Wine of Life , his first collection, were hailed by C.P. Snow as "some of the wisest, wittiest and best informed I have ever read," and Carl Sagan called them "a delight to read." In later volumes he established a reputation for a wide-ranging intellect, an ability to see unexpected connections and draw striking parallels, and a talent for communicating scientific ideas with optimism and wit. With Entropy and the Magic Flute , Morowitz once again offers an appealing mix of brief reflections on everything from litmus paper to the hippopotamus to the sociology of Palo Alto coffee shops. Many of these pieces are appreciations of scientists that Morowitz holds in high regard, while others focus on health issues, such as America's obsession with cheese toppings. There is also a fascinating piece on the American Type Culture Collection, a zoo or warehouse for microbes that houses some 11,800 strains of bacteria, and over 3,000 specimens of protozoa, algae, plasmids, and oncogenes. Here then are over forty light, graceful essays in which one of our wisest experimental biologists comments on issues of science, technology, society, philosophy, and the arts.

  14. Cross sections for neutron-producing reactions induced by 14. 1 MeV neutrons incident on /sup 6/Li, /sup 7/Li, /sup 10/B, /sup 11/B, and carbon

    SciTech Connect

    Drosg, M.; Lisowski, P.W.; Drake, D.M.; Hardekopf, R.A.; Muellner, M.

    1988-10-01

    Using the time-of-flight technique, we have measured neutron emission spectra for /sup 6/Li, /sup 7/Li, /sup 10/B, /sup 11/B and carbon at an incident neutron energy of 14.1 MeV and at 10 angles between 30/degree/ and 143/degree/. Double differential cross sections and their integrated values have been extracted and are presented in tables and graphs. The nonelastic portion of the neutron emission spectra is noticeably higher than expected which may be due to uncertainties in the input library (ENDF/B-IV) used in the Monte Carlo correction for multiple scattering. In particular, the library for /sup 11/B appears to be very unrealistic with an integrated elastic cross section which should be higher by 50%. 20 refs., 1 fig., 12 tabs.

  15. The Magnetics Information Consortium (MagIC)

    NASA Astrophysics Data System (ADS)

    Johnson, C.; Constable, C.; Tauxe, L.; Koppers, A.; Banerjee, S.; Jackson, M.; Solheid, P.

    2003-12-01

    The Magnetics Information Consortium (MagIC) is a multi-user facility to establish and maintain a state-of-the-art relational database and digital archive for rock and paleomagnetic data. The goal of MagIC is to make such data generally available and to provide an information technology infrastructure for these and other research-oriented databases run by the international community. As its name implies, MagIC will not be restricted to paleomagnetic or rock magnetic data only, although MagIC will focus on these kinds of information during its setup phase. MagIC will be hosted under EarthRef.org at http://earthref.org/MAGIC/ where two "integrated" web portals will be developed, one for paleomagnetism (currently functional as a prototype that can be explored via the http://earthref.org/databases/PMAG/ link) and one for rock magnetism. The MagIC database will store all measurements and their derived properties for studies of paleomagnetic directions (inclination, declination) and their intensities, and for rock magnetic experiments (hysteresis, remanence, susceptibility, anisotropy). Ultimately, this database will allow researchers to study "on the internet" and to download important data sets that display paleo-secular variations in the intensity of the Earth's magnetic field over geological time, or that display magnetic data in typical Zijderveld, hysteresis/FORC and various magnetization/remanence diagrams. The MagIC database is completely integrated in the EarthRef.org relational database structure and thus benefits significantly from already-existing common database components, such as the EarthRef Reference Database (ERR) and Address Book (ERAB). The ERR allows researchers to find complete sets of literature resources as used in GERM (Geochemical Earth Reference Model), REM (Reference Earth Model) and MagIC. The ERAB contains addresses for all contributors to the EarthRef.org databases, and also for those who participated in data collection, archiving and

  16. Integrin CD11b positively regulates TLR4-induced signalling pathways in dendritic cells but not in macrophages

    NASA Astrophysics Data System (ADS)

    Ling, Guang Sheng; Bennett, Jason; Woollard, Kevin J.; Szajna, Marta; Fossati-Jimack, Liliane; Taylor, Philip R.; Scott, Diane; Franzoso, Guido; Cook, H. Terence; Botto, Marina

    2014-01-01

    Tuned and distinct responses of macrophages and dendritic cells to Toll-like receptor 4 (TLR4) activation induced by lipopolysaccharide (LPS) underpin the balance between innate and adaptive immunity. However, the molecule(s) that confer these cell-type-specific LPS-induced effects remain poorly understood. Here we report that the integrin αM (CD11b) positively regulates LPS-induced signalling pathways selectively in myeloid dendritic cells but not in macrophages. In dendritic cells, which express lower levels of CD14 and TLR4 than macrophages, CD11b promotes MyD88-dependent and MyD88-independent signalling pathways. In particular, in dendritic cells CD11b facilitates LPS-induced TLR4 endocytosis and is required for the subsequent signalling in the endosomes. Consistent with this, CD11b deficiency dampens dendritic cell-mediated TLR4-triggered responses in vivo leading to impaired T-cell activation. Thus, by modulating the trafficking and signalling functions of TLR4 in a cell-type-specific manner CD11b fine tunes the balance between adaptive and innate immune responses initiated by LPS.

  17. On the implementation of a chain nuclear reaction of thermonuclear fusion on the basis of the p+11B process

    NASA Astrophysics Data System (ADS)

    Belyaev, V. S.; Krainov, V. P.; Zagreev, B. V.; Matafonov, A. P.

    2015-07-01

    Various theoretical and experimental schemes for implementing a thermonuclear reactor on the basis of the p+11B reaction are considered. They include beam collisions, fusion in degenerate plasmas, ignition upon plasma acceleration by ponderomotive forces, and the irradiation of a solid-state target from 11B with a proton beam under conditions of a Coulomb explosion of hydrogen microdrops. The possibility of employing ultra-short high-intensity laser pulses to initiate the p+11B reaction under conditions far from thermodynamic equilibrium is discussed. This and some other weakly radioactive thermonuclear reactions are promising owing to their ecological cleanness—there are virtually no neutrons among fusion products. Nuclear reactions that follow the p+11B reaction may generate high-energy protons, sustaining a chain reaction, and this is an advantage of the p+11B option. The approach used also makes it possible to study nuclear reactions under conditions close to those in the early Universe or in the interior of stars.

  18. High-Throughput Screening based Identification of Small Molecule Antagonists of Integrin CD11b/CD18 Ligand Binding

    PubMed Central

    Faridi, Mohd Hafeez; Maiguel, Dony; Brown, Brock T.; Suyama, Eigo; Barth, Constantinos J.; Hedrick, Michael; Vasile, Stefan; Sergienko, Eduard; Schürer, Stephan; Gupta, Vineet

    2010-01-01

    Binding of leukocyte specific integrin CD11b/CD18 to its physiologic ligands is important for the development of normal immune response in vivo. Integrin CD11b/CD18 is also a key cellular effector of various inflammatory and autoimmune diseases. However, small molecules selectively inhibiting the function of integrin CD11b/CD18 are currently lacking. We used a newly described cell-based high throughput screening assay to identify a number of highly potent antagonists of integrin CD11b/CD18 from chemical libraries containing >100,000 unique compounds. Computational analyses suggest that the identified compounds cluster into several different chemical classes. A number of the newly identified compounds blocked adhesion of wild-type mouse neutrophils to CD11b/CD18 ligand fibrinogen. Mapping the most active compounds against chemical fingerprints of known antagonists of related integrin CD11a/CD18 shows little structural similarity, suggesting that the newly identified compounds are novel and unique. PMID:20188705

  19. Peculiarities of changes of some physicomechanical characteristics of monoisotopes {sup 10}B, {sup 11}B and natural {beta}-boron

    SciTech Connect

    Gabunia, D. . E-mail: d_gabunia@hotmail.com; Tsagareishvili, O.; Lezhava, D.; Gabunia, L.; Antadze, M.; Darsavelidze, G.; Tanaka, T.

    2006-09-15

    Real structure and some physicomechanical characteristics of the samples of natural beta-rhombohedral boron B as well as of its {sup 10}B and {sup 11}B monoisotopes have been studied. It was shown that the influence of {sup 10}B and {sup 11}B isotopes on physicomechanical properties of boron had a different character. In particular, the samples enriched with {sup 11}B had high values of microhardness, shear modulus (SM) and elastic limit if compared to those of boron, while the samples enriched with {sup 10}B monoisotopes were characterized with high values of thermal expansion coefficient (TEC) and thermal conductivity; lattice parameters a and c increased by the sequence: {sup 11}B, B, {sup 10}B. It was established that TEC, thermal conductivity, microhardness, SM and shear elastic limit increased in all samples at annealing for 5 h at 1500 deg. C regardless of isotope content. - Graphical abstract: Temperature dependence of the SM in the samples of natural boron B, {sup 10}B and {sup 11}B monoisotopes.

  20. α1B-Adrenergic receptor signaling controls circadian expression of Tnfrsf11b by regulating clock genes in osteoblasts

    PubMed Central

    Hirai, Takao; Tanaka, Kenjiro; Togari, Akifumi

    2015-01-01

    ABSTRACT Circadian clocks are endogenous and biological oscillations that occur with a period of <24 h. In mammals, the central circadian pacemaker is localized in the suprachiasmatic nucleus (SCN) and is linked to peripheral tissues through neural and hormonal signals. In the present study, we investigated the physiological function of the molecular clock on bone remodeling. The results of loss-of-function and gain-of-function experiments both indicated that the rhythmic expression of Tnfrsf11b, which encodes osteoprotegerin (OPG), was regulated by Bmal1 in MC3T3-E1 cells. We also showed that REV-ERBα negatively regulated Tnfrsf11b as well as Bmal1 in MC3T3-E1 cells. We systematically investigated the relationship between the sympathetic nervous system and the circadian clock in osteoblasts. The administration of phenylephrine, a nonspecific α1-adrenergic receptor (AR) agonist, stimulated the expression of Tnfrsf11b, whereas the genetic ablation of α1B-AR signaling led to the alteration of Tnfrsf11b expression concomitant with Bmal1 and Per2 in bone. Thus, this study demonstrated that the circadian regulation of Tnfrsf11b was regulated by the clock genes encoding REV-ERBα (Nr1d1) and Bmal1 (Bmal1, also known as Arntl), which are components of the core loop of the circadian clock in osteoblasts. PMID:26453621

  1. Integrin CD11b positively regulates TLR4-induced signalling pathways in dendritic cells but not in macrophages.

    PubMed

    Ling, Guang Sheng; Bennett, Jason; Woollard, Kevin J; Szajna, Marta; Fossati-Jimack, Liliane; Taylor, Philip R; Scott, Diane; Franzoso, Guido; Cook, H Terence; Botto, Marina

    2014-01-01

    Tuned and distinct responses of macrophages and dendritic cells to Toll-like receptor 4 (TLR4) activation induced by lipopolysaccharide (LPS) underpin the balance between innate and adaptive immunity. However, the molecule(s) that confer these cell-type-specific LPS-induced effects remain poorly understood. Here we report that the integrin α(M) (CD11b) positively regulates LPS-induced signalling pathways selectively in myeloid dendritic cells but not in macrophages. In dendritic cells, which express lower levels of CD14 and TLR4 than macrophages, CD11b promotes MyD88-dependent and MyD88-independent signalling pathways. In particular, in dendritic cells CD11b facilitates LPS-induced TLR4 endocytosis and is required for the subsequent signalling in the endosomes. Consistent with this, CD11b deficiency dampens dendritic cell-mediated TLR4-triggered responses in vivo leading to impaired T-cell activation. Thus, by modulating the trafficking and signalling functions of TLR4 in a cell-type-specific manner CD11b fine tunes the balance between adaptive and innate immune responses initiated by LPS. PMID:24423728

  2. MAGIC observations and multifrequency properties of the flat spectrum radio quasar 3C 279 in 2011

    NASA Astrophysics Data System (ADS)

    Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Berger, K.; Bernardini, E.; Biland, A.; Blanch, O.; Bock, R. K.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Carreto Fidalgo, D.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; Delgado Mendez, C.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Farina, E.; Ferenc, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giavitto, G.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Hadasch, D.; Herrero, A.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Kadenius, V.; Kellermann, H.; Knoetig, M. L.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; López, M.; López-Coto, R.; López-Oramas, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Meucci, M.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Niedzwiecki, A.; Nilsson, K.; Nishijima, K.; Nowak, N.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Partini, S.; Persic, M.; Prada, F.; Prada Moroni, P. G.; Prandini, E.; Preziuso, S.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Rügamer, S.; Saggion, A.; Saito, T.; Saito, K.; Salvati, M.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Stamatescu, V.; Stamerra, A.; Steinbring, T.; Storz, J.; Sun, S.; Surić, T.; Takalo, L.; Takami, H.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Tibolla, O.; Torres, D. F.; Toyama, T.; Treves, A.; Vogler, P.; Wagner, R. M.; Zandanel, F.; Zanin, R.

    2014-07-01

    Aims: We study the multifrequency emission and spectral properties of the quasar3C 279 aimed at identifying the radiation processes taking place in the source. Methods: We observed 3C 279 in very-high-energy (VHE, E> 100 GeV) γ-rays, with the MAGIC telescopes during 2011, for the first time in stereoscopic mode. We combined these measurements with observations at other energy bands: in high-energy (HE, E> 100 MeV) γ-rays from Fermi-LAT; in X-rays from RXTE; in the optical from the KVA telescope; and in the radio at 43 GHz, 37 GHz, and 15 GHz from the VLBA, Metsähovi, and OVRO radio telescopes - along with optical polarisation measurements from the KVA and Liverpool telescopes. We examined the corresponding light curves and broadband spectral energy distribution and we compared the multifrequency properties of 3C 279 at the epoch of the MAGIC observations with those inferred from historical observations. Results: During the MAGIC observations (2011 February 8 to April 11) 3C 279 was in a low state in optical, X-ray, and γ-rays. The MAGIC observations did not yield a significant detection. The derived upper limits are in agreement with the extrapolation of the HE γ-ray spectrum, corrected for EBL absorption, from Fermi-LAT. The second part of the MAGIC observations in 2011 was triggered by a high-activity state in the optical and γ-ray bands. During the optical outburst the optical electric vector position angle (EVPA) showed a rotation of ~180°. Unlike previous cases, there was no simultaneous rotation of the 43 GHz radio polarisation angle. No VHE γ-rays were detected by MAGIC, and the derived upper limits suggest the presence of a spectral break or curvature between the Fermi-LAT and MAGIC bands. The combined upper limits are the strongest derived to date for the source at VHE and below the level of the previously detected flux by a factor of ~2. Radiation models that include synchrotron and inverse Compton emissions match the optical to γ-ray data

  3. Origins of magic: review of genetic and epigenetic effects

    PubMed Central

    2007-01-01

    Objective To assess the evidence for a genetic basis to magic. Design Literature review. Setting Harry Potter novels of J K Rowling. Participants Muggles, witches, wizards, and squibs. Interventions Limited. Main outcome measures Family and twin studies, magical ability, and specific magical skills. Results Magic shows strong evidence of heritability, with familial aggregation and concordance in twins. Evidence suggests magical ability to be a quantitative trait. Specific magical skills, notably being able to speak to snakes, predict the future, and change hair colour, all seem heritable. Conclusions A multilocus model with a dominant gene for magic might exist, controlled epistatically by one or more loci, possibly recessive in nature. Magical enhancers regulating gene expressionmay be involved, combined with mutations at specific genes implicated in speech and hair colour such as FOXP2 and MCR1. PMID:18156238

  4. A Simple Parameterization of 3 x 3 Magic Squares

    ERIC Educational Resources Information Center

    Trenkler, Gotz; Schmidt, Karsten; Trenkler, Dietrich

    2012-01-01

    In this article a new parameterization of magic squares of order three is presented. This parameterization permits an easy computation of their inverses, eigenvalues, eigenvectors and adjoints. Some attention is paid to the Luoshu, one of the oldest magic squares.

  5. Multimodal Imaging Using a 11B(d,nγ)12C Source

    NASA Astrophysics Data System (ADS)

    Nattress, Jason; Rose, Paul; Mayer, Michal; Wonders, Marc; Wilhelm, Kyle; Erickson, Anna; Jovanovic, Igor; Multimodal Imaging; Nuclear Detection (MIND) in Active Interrogation Collaboration

    2016-03-01

    Detection of shielded special nuclear material (SNM) still remains one of the greatest challenges facing nuclear security, where small signal-to-background ratios result from complex, challenging configurations of practical objects. Passive detection relies on the spontaneous radioactive decay, whereas active interrogation (AI) uses external probing radiation to identify and characterize the material. AI provides higher signal intensity, providing a more viable method for SNM detection. New and innovative approaches are needed to overcome specific application constraints, such as limited scanning time. We report on a new AI approach that integrates both neutron and gamma transmission signatures to deduce specific material properties that can be utilized to aid SNM identification. The approach uses a single AI source, single detector type imaging system based on the 11B(d,nγ)12C reaction and an array of eight EJ-309 liquid scintillators, respectively. An integral transmission imaging approach has been employed initially for both neutrons and photons, exploiting the detectors' particle discrimination properties. Representative object images using neutrons and photons will be presented.

  6. CMOS analog baseband circuitry for an IEEE 802.11 b/g/n WLAN transceiver

    NASA Astrophysics Data System (ADS)

    Zheng, Gong; Xiaojie, Chu; Qianqian, Lei; Min, Lin; Yin, Shi

    2012-11-01

    An analog baseband circuit for a direct conversion wireless local area network (WLAN) transceiver in a standard 0.13-μm CMOS occupying 1.26 mm2 is presented. The circuit consists of active-RC receiver (RX) 4th order elliptic lowpass filters(LPFs), transmit (PGAs) with DC offset cancellation (DCOC) servo loops, and on-chip output buffers. The RX baseband gain can be programmed in the range of -11 to 49 dB in 2 dB steps with 50-30.2 nV/√Hz input referred noise (IRN) and a 21 to -41 dBm in-band 3rd order interception point (IIP3). The RX/TX LPF cutoff frequencies can be switched between 5 MHz, 10 MHz, and 20 MHz to fulfill the multimode 802.11b/g/n requirements. The TX baseband gain of the I/Q paths are tuned separately from -1.6 to 0.9 dB in 0.1 dB steps to calibrate TX I/Q gain mismatches. By using an identical integrator based elliptic filter synthesis method together with global compensation applied to the LPF capacitor array, the power consumption of the RX LPF is considerably reduced and the proposed chip draws 26.8 mA/8 mA by the RX/TX baseband paths from a 1.2 V supply.

  7. Direct measurement of 11B(p ,γ )12C astrophysical S factors at low energies

    NASA Astrophysics Data System (ADS)

    He, J. J.; Jia, B. L.; Xu, S. W.; Chen, S. Z.; Ma, S. B.; Hou, S. Q.; Hu, J.; Zhang, L. Y.; Yu, X. Q.

    2016-05-01

    We directly measure the absolute cross section of 11B(p ,γ )12C in the energy region of Ec .m .=130 -257 keV by using a thin target for the first time. This work is performed on a 320-kV platform at the Institute of Modern Physics in Lanzhou. The astrophysical S factors of this reaction are obtained for capture to the ground and first excited states of 12C. The properties of the known resonance at ˜150 keV are derived and agree with the previous results. However, in the energy region of 170-240 keV, our S factors are about 15%-50% larger than the adopted values in NACRE II and are also larger than the upper limits of NACRE II by up to ˜20 % . This indicates that our new reaction rate is enhanced by about 15%-50% compared to the NACRE II adopted rate in the temperature region 0.32-0.62 GK.

  8. THE OBLIQUE ORBIT OF THE SUPER-NEPTUNE HAT-P-11b

    SciTech Connect

    Winn, Joshua N.; Albrecht, Simon; Johnson, John Asher; Howard, Andrew W.; Marcy, Geoffrey W.; Isaacson, Howard; Shporer, Avi; Bakos, Gaspar A.; Hartman, Joel D.

    2010-11-10

    We find the orbit of the Neptune-sized exoplanet HAT-P-11b to be highly inclined relative to the equatorial plane of its host star. This conclusion is based on spectroscopic observations of two transits, which allowed the Rossiter-McLaughlin effect to be detected with an amplitude of 1.5 m s{sup -1}. The sky-projected obliquity is 103{sup +26} {sub -10} deg. This is the smallest exoplanet for which spin-orbit alignment has been measured. The result favors a migration scenario involving few-body interactions followed by tidal dissipation. This finding also conforms with the pattern that the systems with the weakest tidal interactions have the widest spread in obliquities. We predict that the high obliquity of HAT-P-11 will be manifest in transit light curves from the Kepler spacecraft: starspot-crossing anomalies will recur at most once per stellar rotation period, rather than once per orbital period as they would for a well-aligned system.

  9. BSH distributions in the canine head and a human patient using 11B MRI.

    PubMed

    Bradshaw, K M; Schweizer, M P; Glover, G H; Hadley, J R; Tippets, R; Tang, P P; Davis, W L; Heilbrun, M P; Johnson, S; Ghanem, T

    1995-07-01

    A 3D projection reconstruction (3DPR) method was used to obtain in vivo 11B images in a large canine brain tumor model and in a human infused with borocaptate sodium (BSH). Studies were performed in dogs with and without gliosarcomas implanted and grown to a size of 2-3 cm. The 3DPR method demonstrates a signal-to-noise ratio (SNR) that allows qualitative kinetic studies of the boron compound in normal and tumor tissue of the head. The measurements indicate initial uptake of the BSH compound in tumor to be less than that in muscle with no uptake in normal brain tissue. Moreover, uptake of BSH in tissue was found to lag the boron concentration in blood with delays that depend on tissue type. In addition, the first human boron images were obtained on a patient who underwent surgical resection and volumetric debulking of a large (7 cm) glioblastoma multiforme. BSH was readily taken up in residual tumor tissue, while diffusion into the resection volume was slower. PMID:7674898

  10. Quantitation of intracellular Mac-1 (CD11b/CD18) pools in human neutrophils.

    PubMed

    Jones, D H; Anderson, D C; Burr, B L; Rudloff, H E; Smith, C W; Krater, S S; Schmalstieg, F C

    1988-12-01

    The adhesive glycoprotein Mac-1 (CD11b/CD18) of the CD11/CD18 complex contributes to multiple neutrophil inflammatory functions. Activation of neutrophils by chemotactic stimuli results in a rapid, protein synthesis-independent increase in surface Mac-1 derived from incompletely defined intracellular compartments. Therefore, we developed a novel quantitative lectin immunoblot technique to define intracellular pools of Mac-1 in subcellular neutrophil fractions resolved on discontinuous Percoll gradients. In cavitates of unstimulated neutrophils, 30% and 26% of total Mac-1 was identified in beta [1.10 gm/ml; vitamin B12 binding protein (vit B12 B.P.)-rich] or pre-gamma (1.07 gm/ml; vit B12 B.P.-poor) granular fractions, respectively, whereas 24% was associated with the plasma membrane-rich gamma (1.06 gm/ml) fractions. N-formyl-methionyl-leucyl-phenylalanine (fMLP) stimulation (10(-8) M, 15 min, 37 degrees C) significantly diminished Mac-1 in pre-gamma (-18% of total, P less than 0.05) but not beta fractions (+6% of total). Under these conditions, the content of Mac-1 in gamma fractions increased 13% in association with four- to eightfold increase in surface Mac-1 expression (OKM-1 binding). These findings suggest that chemotactic stimuli increase plasma membrane and/or surface Mac-1 on human neutrophils by mobilizing a novel intracellular granule pool. PMID:2903896

  11. Magic numbers in the neutron-rich oxygen isotopes

    SciTech Connect

    Brown, B. Alex; Richter, W.A.

    2005-11-01

    The predicted and experimental properties of the new doubly magic nuclei {sup 22}O and {sup 24}O are discussed. These together with previous observations lead to a new rule for magic numbers: if there is an oscillator magic number (2, 8, 20, or 40) for one kind of nucleon, then the other kind of nucleon has a magic number for the filling of every possible (n, l, j) value.

  12. The Moore-Penrose Inverse of Block Magic Rectangles

    ERIC Educational Resources Information Center

    Hakopian, Y. R.; Eloyan, A. N.

    2007-01-01

    As is known, a semi-magic square is an "n x n" matrix having the sum of entries in each row and each column equal to a constant. This note generalizes this notion and introduce a special class of block matrices called "block magic rectangles." It is proved that the Moore-Penrose inverse of a block magic rectangle is also a block magic rectangle.

  13. Distilling one-qubit magic states into Toffoli states

    NASA Astrophysics Data System (ADS)

    Eastin, Bryan

    2013-03-01

    For certain quantum architectures and algorithms, most of the required resources are consumed during the distillation of one-qubit magic states for use in performing Toffoli gates. I show that the overhead for magic-state distillation can be reduced by merging distillation with the implementation of Toffoli gates. The resulting routine distills eight one-qubit magic states directly to a Toffoli state, which can be used without further magic to perform a Toffoli gate.

  14. Atmospheric monitoring in MAGIC and data corrections

    NASA Astrophysics Data System (ADS)

    Fruck, Christian; Gaug, Markus

    2015-03-01

    A method for analyzing returns of a custom-made "micro"-LIDAR system, operated alongside the two MAGIC telescopes is presented. This method allows for calculating the transmission through the atmospheric boundary layer as well as thin cloud layers. This is achieved by applying exponential fits to regions of the back-scattering signal that are dominated by Rayleigh scattering. Making this real-time transmission information available for the MAGIC data stream allows to apply atmospheric corrections later on in the analysis. Such corrections allow for extending the effective observation time of MAGIC by including data taken under adverse atmospheric conditions. In the future they will help reducing the systematic uncertainties of energy and flux.

  15. Evaluation of exchange interactions in (Gd xY 1- x) 3Co 11B 4 compounds

    NASA Astrophysics Data System (ADS)

    Jin, Zhiqiang; Tang, Wei; Qin, Hongxia; Zhang, Jianrong; Youwei, Du

    1998-01-01

    Two-sublattice molecular field theory (MFT) is employed to describe the temperature dependence of magnetization for (Gd xY 1- x) 3Co 11B 4 compounds. Three molecular field coefficients, nRCo, nCoCo, nRR, have been calculated by a numerical fitting process. MFT with a single coefficient provides quite a reasonable description for Y 3Co 11B 4. For x > 0, we find that nCoCo is the largest coefficient, implying that the magnetic interactions are dominated by exchange between cobalt 3d electrons.

  16. Analysis of 8Li(α,n)11B below the Coulomb barrier in the potential model

    NASA Astrophysics Data System (ADS)

    Rauscher, T.; Grün, K.; Krauss, H.; Oberhummer, H.; Kwasniewicz, E.

    1992-04-01

    The reaction 8Li(α,n)11B is of interest in inhomogeneous big bang nucleosynthesis. A distorted wave Born approximation calculation employing folding potentials is presented for energies below the Coulomb barrier. The recently observed resonance at about 540 keV center-of-mass energy can be reproduced. The astrophysical S factor is calculated for the ground-state transition as well as for the transitions to the first four excited states of 11B. The reaction rate is derived and compared to literature data. The inclusion of the excited states increases the rate by a factor of 1.5 compared to the ground-state transition.

  17. Au40: A large tetrahedral magic cluster

    NASA Astrophysics Data System (ADS)

    Jiang, De-En; Walter, Michael

    2011-11-01

    40 is a magic number for tetrahedral symmetry predicted in both nuclear physics and the electronic jellium model. We show that Au40 could be such a a magic cluster from density functional theory-based basin hopping for global minimization. The putative global minimum found for Au40 has a twisted pyramid structure, reminiscent of the famous tetrahedral Au20, and a sizable HOMO-LUMO gap of 0.69 eV, indicating its molecular nature. Analysis of the electronic states reveals that the gap is related to shell closings of the metallic electrons in a tetrahedrally distorted effective potential.

  18. Au40: A Large Tetrahedral Magic Cluster

    SciTech Connect

    Jiang, Deen; Walter, Michael

    2011-01-01

    40 is a magic number for tetrahedral symmetry predicted in both nuclear physics and the electronic jellium model. We show that Au{sub 40} could be such a magic cluster from density functional theory-based basin hopping for global minimization. The putative global minimum found for Au{sub 40} has a twisted pyramid structure, reminiscent of the famous tetrahedral Au{sub 20}, and a sizable HOMO-LUMO gap of 0.69 eV, indicating its molecular nature. Analysis of the electronic states reveals that the gap is related to shell closings of the metallic electrons in a tetrahedrally distorted effective potential.

  19. The Reflecting Surface of the MAGIC Telescope

    NASA Astrophysics Data System (ADS)

    Bastieri, D.; Bigongiari, C.; Galante, N.; Lorenz, E.; Mariotti, M.; Mirzoyan, R.; Moralejo, A.; Pepato, A.; Peruzzo, L.; Saggion, A.; Scalzotto, V.; Tonello, N.; MAGIC Collaboration

    2003-07-01

    ˇ The MAGIC Collab oration is starting to operate the Cerenkov telescope with the largest reflecting surface, in order to lower the energy threshold well ˇ below 100 GeV. The MAGIC (Ma jor Atmospheric Gamma Imaging Cerenkov) telescope has a 17 m diameter parab olic surface F/1, consisting of 956 spherical aluminium mirrors (50 × 50 cm2 each). In this contribution, we describe the technology adopted to produce metallic mirrors and the methods used to measure the optical quality in terms of: reflectivity, radius of curvature, spot dimension and geometry.

  20. Toward better understanding of B/Ca and δ11B proxies: An experimental approach

    NASA Astrophysics Data System (ADS)

    Uchikawa, J.; Penman, D. E.; Harper, D. T.; Farmer, J. R.; Zachos, J. C.; Hoenisch, B.; Zeebe, R. E.

    2015-12-01

    The abundance and isotopic composition of boron (B/Ca and δ11B) in marine biogenic carbonates is an important paleoceanographic tool to probe carbon cycling in the ocean-atmosphere system. These B-based proxies rely on a fundamental assumption that boron incorporation into carbonates occur via B(OH)4- adsorption with little isotopic fractionation, which is based on key results from the classic inorganic experiments performed in the late 1990s (e.g., Hemming et al., 1995, GCA, v59, 371-379; Sanyal et al., 2000, GCA, v64, 1551-1555). However, a collection of new experimental data published in recent years consistently suggests a more complicated picture for fluid-crystal element and isotope partitioning of B into inorganic carbonates. For instance, we performed novel inorganic calcite precipitation experiments by systematically adjusting solution pH as well as total B, total DIC and Ca concentrations (Uchikawa et al., 2015, GCA, v150, 171-191), and the results showcased apparent kinetic effects related to precipitation rate on B/Ca. Moreover, the results also indicated a dependence of B/Ca on the concentration ratio of total B to total DIC, which was interpreted as indirect evidence for potential B(OH)3 incorporation into synthetic calcite. Notably, relatively simple solutions of NaCl-CaCl2-B(OH)3 system were used for our previous experiments. This presentation features our latest results from similar experiments but using artificial seawater in order to close the gap between simplified experimental conditions to in-situ marine settings. Our preliminary results reveal a precipitation rate control even when artificial seawater is used for the experiments, making a strong case that kinetic effects on B/Ca are universal in inorganic carbonates. With the aid of new isotopic results, we also attempt to discuss possible scenarios of B incorporation pathway in inorganic systems.

  1. Kepler and Ground-Based Transits of the exo-Neptune HAT-P-11b

    NASA Technical Reports Server (NTRS)

    Deming, Drake; Sada, Pedro V.; Jackson, Brian; Peterson, Steven W.; Agol, Eric; Knutson, Heather A.; Jennings, Donald E.; Haase, Plynn; Bays, Kevin

    2011-01-01

    We analyze 26 archival Kepler transits of the exo-Neptune HAT-P-11b, supplemented by ground-based transits observed in the blue (B band) and near-IR (J band). Both the planet and host star are smaller than previously believed; our analysis yields Rp = 4.31 R xor 0.06 R xor and Rs = 0.683 R solar mass 0.009 R solar mass, both about 3 sigma smaller than the discovery values. Our ground-based transit data at wavelengths bracketing the Kepler bandpass serve to check the wavelength dependence of stellar limb darkening, and the J-band transit provides a precise and independent constraint on the transit duration. Both the limb darkening and transit duration from our ground-based data are consistent with the new Kepler values for the system parameters. Our smaller radius for the planet implies that its gaseous envelope can be less extensive than previously believed, being very similar to the H-He envelope of GJ 436b and Kepler-4b. HAT-P-11 is an active star, and signatures of star spot crossings are ubiquitous in the Kepler transit data. We develop and apply a methodology to correct the planetary radius for the presence of both crossed and uncrossed star spots. Star spot crossings are concentrated at phases 0.002 and +0.006. This is consistent with inferences from Rossiter-McLaughlin measurements that the planet transits nearly perpendicular to the stellar equator. We identify the dominant phases of star spot crossings with active latitudes on the star, and infer that the stellar rotational pole is inclined at about 12 deg 5 deg to the plane of the sky. We point out that precise transit measurements over long durations could in principle allow us to construct a stellar Butterfly diagram to probe the cyclic evolution of magnetic activity on this active K-dwarf star.

  2. A comparison of various algorithms to extract Magic Formula tyre model coefficients for vehicle dynamics simulations

    NASA Astrophysics Data System (ADS)

    Vijay Alagappan, A.; Narasimha Rao, K. V.; Krishna Kumar, R.

    2015-02-01

    Tyre models are a prerequisite for any vehicle dynamics simulation. Tyre models range from the simplest mathematical models that consider only the cornering stiffness to a complex set of formulae. Among all the steady-state tyre models that are in use today, the Magic Formula tyre model is unique and most popular. Though the Magic Formula tyre model is widely used, obtaining the model coefficients from either the experimental or the simulation data is not straightforward due to its nonlinear nature and the presence of a large number of coefficients. A common procedure used for this extraction is the least-squares minimisation that requires considerable experience for initial guesses. Various researchers have tried different algorithms, namely, gradient and Newton-based methods, differential evolution, artificial neural networks, etc. The issues involved in all these algorithms are setting bounds or constraints, sensitivity of the parameters, the features of the input data such as the number of points, noisy data, experimental procedure used such as slip angle sweep or tyre measurement (TIME) procedure, etc. The extracted Magic Formula coefficients are affected by these variants. This paper highlights the issues that are commonly encountered in obtaining these coefficients with different algorithms, namely, least-squares minimisation using trust region algorithms, Nelder-Mead simplex, pattern search, differential evolution, particle swarm optimisation, cuckoo search, etc. A key observation is that not all the algorithms give the same Magic Formula coefficients for a given data. The nature of the input data and the type of the algorithm decide the set of the Magic Formula tyre model coefficients.

  3. Sintering process and critical current density of low activation Mg11B2 superconductors from low temperature to high temperature

    NASA Astrophysics Data System (ADS)

    Cheng, Fang; Liu, Yongchang; Ma, Zongqing; Shahriar Al Hossain, Md; Somer, M.

    2016-08-01

    As the "low activation" superconductor, Mg11B2 has a potential application in superconducting coils for fusion reactor. In present work, the sintering process and critical current density of low activation Mg11B2 superconductors were systemically studied from low temperature to high temperature. It was found that the Jc and Hirr values of Mg11B2 bulks in present work are both obviously higher than that of those samples prepared in previous studies. Furthermore, the low-temperature sintered samples exhibit better Jc performance at high fields than the high-temperature sintered samples, due to strong grain boundaries pinning. On the other hand, the high-temperature sintered samples have higher Jc at low fields compared to low-temperature sintered samples, mainly owing to their better crystallinity and grain connectivity. The highest Jc value (2.20 ×105 A cm-2 at 20 K, self-field) is obtained in the Mg11B2 sample sintered at 850 °C for 45 min.

  4. IL-1α induces CD11b(low) alveolar macrophage proliferation and maturation during granuloma formation.

    PubMed

    Huaux, François; Lo Re, Sandra; Giordano, Giulia; Uwambayinema, Francine; Devosse, Raynal; Yakoub, Yousof; Panin, Nadtha; Palmai-Pallag, Mihaly; Rabolli, Virginie; Delos, Monique; Marbaix, Etienne; Dauguet, Nicolas; Couillin, Isabelle; Ryffel, Bernhard; Renauld, Jean-Christophe; Lison, Dominique

    2015-04-01

    Macrophages play a central role in immune and tissue responses of granulomatous lung diseases induced by pathogens and foreign bodies. Circulating monocytes are generally viewed as central precursors of these tissue effector macrophages. Here, we provide evidence that granulomas derive from alveolar macrophages serving as a local reservoir for the expansion of activated phagocytic macrophages. By exploring lung granulomatous responses to silica particles in IL-1-deficient mice, we found that the absence of IL-1α, but not IL-1β, was associated with reduced CD11b(high) phagocytic macrophage accumulation and fewer granulomas. This defect was associated with impaired alveolar clearance and resulted in the development of pulmonary alveolar proteinosis (PAP). Reconstitution of IL-1α(-/-) mice with recombinant IL-1α restored lung clearance functions and the pulmonary accumulation of CD11b(high) phagocytic macrophages. Mechanistically, IL-1α induced the proliferation of CD11b(low) alveolar macrophages and differentiated these cells into CD11b(high) macrophages which perform critical phagocytic functions and organize granuloma. We newly discovered here that IL-1α triggers lung responses requiring macrophage proliferation and maturation from tissue-resident macrophages. PMID:25421226

  5. GM-CSF-licensed CD11b+ lung dendritic cells orchestrate Th2 immunity to Blomia tropicalis.

    PubMed

    Zhou, Qian; Ho, Adrian W S; Schlitzer, Andreas; Tang, Yafang; Wong, Kenneth H S; Wong, Fiona H S; Chua, Yen Leong; Angeli, Veronique; Mortellaro, Alessandra; Ginhoux, Florent; Kemeny, David M

    2014-07-15

    The Blomia tropicalis dust mite is prevalent in tropical and subtropical regions of the world. Although it is a leading cause of asthma, little is known how it induces allergy. Using a novel murine asthma model induced by intranasal exposure to B. tropicalis, we observed that a single intranasal sensitization to B. tropicalis extract induces strong Th2 priming in the lung draining lymph node. Resident CD11b(+) dendritic cells (DCs) preferentially transport Ag from the lung to the draining lymph node and are crucial for the initiation of Th2 CD4(+) T cell responses. As a consequence, mice selectively deficient in CD11b(+) DCs exhibited attenuated Th2 responses and more importantly did not develop any allergic inflammation. Conversely, mice deficient in CD103(+) DCs and CCR2-dependent monocyte-derived DCs exhibited similar allergic inflammation compared with their wild-type counterparts. We also show that CD11b(+) DCs constitutively express higher levels of GM-CSF receptor compared with CD103(+) DCs and are thus selectively licensed by lung epithelial-derived GM-CSF to induce Th2 immunity. Taken together, our study identifies GM-CSF-licensed CD11b(+) lung DCs as a key component for induction of Th2 responses and represents a potential target for therapeutic intervention in allergy. PMID:24943219

  6. 17 CFR 274.11b - Form N-3, registration statement of separate accounts organized as management investment companies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and on... INVESTMENT COMPANY ACT OF 1940 Registration Statements § 274.11b Form N-3, registration statement of separate... to be filed pursuant to section 8(b) of the Investment Company Act of 1940 by separate accounts...

  7. 17 CFR 274.11b - Form N-3, registration statement of separate accounts organized as management investment companies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at... INVESTMENT COMPANY ACT OF 1940 Registration Statements § 274.11b Form N-3, registration statement of separate... to be filed pursuant to section 8(b) of the Investment Company Act of 1940 by separate accounts...

  8. 17 CFR 274.11b - Form N-3, registration statement of separate accounts organized as management investment companies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at... INVESTMENT COMPANY ACT OF 1940 Registration Statements § 274.11b Form N-3, registration statement of separate... to be filed pursuant to section 8(b) of the Investment Company Act of 1940 by separate accounts...

  9. 17 CFR 274.11b - Form N-3, registration statement of separate accounts organized as management investment companies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at... INVESTMENT COMPANY ACT OF 1940 Registration Statements § 274.11b Form N-3, registration statement of separate... to be filed pursuant to section 8(b) of the Investment Company Act of 1940 by separate accounts...

  10. Antiretroviral Therapy Normalizes Autoantibody Profile of HIV Patients by Decreasing CD33+CD11b+HLA-DR+ Cells

    PubMed Central

    Meng, Zhefeng; Du, Ling; Hu, Ningjie; Byrd, Daniel; Amet, Tohti; Desai, Mona; Shepherd, Nicole; Lan, Jie; Han, Renzhi; Yu, Qigui

    2016-01-01

    Abstract Autoimmune manifestations are common in human immunodeficiency virus (HIV) patients. However, the autoantibody spectrum associated with HIV infection and the impact of antiretroviral therapy (ART) remains to be determined. The plasma autoantibody spectrum for HIV patients was characterized by protein microarrays containing 83 autoantigens and confirmed by enzyme-linked immunosorbent assay (ELISA). Regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) were analyzed by flow cytometry and their effects on autoantibodies production were determined by B cell ELISpot. Higher levels of autoantibody and higher prevalence of elevated autoantibodies were observed in ART-naive HIV patients compared to healthy subjects and HIV patients on ART. The highest frequency of CD33+CD11b+HLA-DR+ cells was observed in ART-naive HIV patients and was associated with the quantity of elevated autoantibodies. In addition, CD33+CD11b+HLA-DR+ cells other than Tregs or MDSCs boost the B cell response in a dose-dependent manner by in vitro assay. In summary, HIV infection leads to elevation of autoantibodies while ART suppresses the autoimmune manifestation by decreasing CD33+CD11b+HLA-DR+ cells in vivo. The roles of CD33+CD11b+HLA-DR+ cells on disease progression in HIV patients needs further assessment. PMID:27082567

  11. 17 CFR 260.11b-6 - Definition of “self-liquidating paper” in section 311(b)(6).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Rules Under Section 311 § 260.11b-6 Definition of “self-liquidating paper” in section 311(b)(6). The term self-liquidating paper, as used in section 311(b)(6) of the Act, means any draft, bill of exchange... simultaneously with the creation of the creditor relationship with the obligor arising from the making,...

  12. 17 CFR 260.11b-6 - Definition of “self-liquidating paper” in section 311(b)(6).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Rules Under Section 311 § 260.11b-6 Definition of “self-liquidating paper” in section 311(b)(6). The term self-liquidating paper, as used in section 311(b)(6) of the Act, means any draft, bill of exchange... simultaneously with the creation of the creditor relationship with the obligor arising from the making,...

  13. Suppression of complete fusion due to breakup in the reactions {sup 10,11}B+{sup 209}Bi

    SciTech Connect

    Gasques, L. R.; Hinde, D. J.; Dasgupta, M.; Mukherjee, A.; Thomas, R. G.

    2009-03-15

    Above-barrier cross sections of fission and {alpha}-active heavy reaction products were measured for the reactions of {sup 10,11}B with {sup 209}Bi. Systematic analysis showed that the fission originates almost exclusively from complete fusion (CF). Existing measurements of above-barrier fusion products for the {sup 30}Si+{sup 186}W reaction, assumed to proceed exclusively through CF, were extrapolated to the current systems using statistical model calculations. This extrapolation showed that the heavy reaction products from the {sup 10,11}B+{sup 209}Bi reactions include substantial components from incomplete fusion as well as from CF. Compared with fusion calculations without breakup, the CF cross sections are suppressed by 15% for {sup 10}B and 7% for {sup 11}B. A consistent and systematic variation of the suppression of CF for reactions of the weakly bound nuclei {sup 6,7}Li, {sup 9}Be, and {sup 10,11}B on targets of {sup 208}Pb and {sup 209}Bi is found as a function of the breakup threshold energy.

  14. EFFECT OF INHALED ENDOTOXIN ON AIRWAY AND CIRCULATING INFLAMMATORY CELL PHAGOCYTOSIS AND CD11B EXPRESSION IN ATOPIC ASTHMATIC SUBJECTS

    EPA Science Inventory

    Effect of inhaled endotoxin on airway and circulating inflammatory cell phagocytosis and CD11b expression in atopic asthmatic subjects

    Neil E. Alexis, PhD, Marlowe W. Eldridge, MD, David B. Peden, MD, MS

    Chapel Hill and Research Triangle Park, NC

    Backgrou...

  15. Combined use of 15N and 18O of nitrate and 11B to evaluate nitrate contamination in groundwater

    USGS Publications Warehouse

    Seiler, R.L.

    2005-01-01

    Isotopic composition of NO3 (??15NNO3 and ??18ONO3) and B (??11B) were used to evaluate NO3 contamination and identify geochemical processes occurring in a hydrologically complex Basin and Range valley in northern Nevada with multiple potential sources of NO3. Combined use of these isotopes may be a useful tool in identifying NO3 sources because NO3 and B co-migrate in many environmental settings, their isotopes are fractionated by different environmental processes, and because wastewater and fertilizers may have distinct isotopic signatures for N and B. The principal cause of elevated NO3 concentrations in residential parts of the study area is wastewater and not natural NO3 or fertilizers. This is indicated by some samples with elevated NO3 concentrations plotting along ??15NNO3 and NO3 mixing lines between natural NO3 from the study area and theoretical septic-system effluent. This conclusion is supported by the presence of caffeine in one sample and the absence of samples with elevated NO3 concentrations that fall along mixing lines between natural NO3 and theoretical percolate below fertilized lawns. Nitrogen isotopes alone could not be used to determine NO3 sources in several wells because denitrification blurred the original isotopic signatures. The range of ??11B values in native ground water in the study area (-8.2??? to +21.2???) is large. The samples with the low ??11B values have a geochemical signature characteristic of hydrothermal systems. Physical and chemical data suggest B is not being strongly fractionated by adsorption onto clays. ??11B values from local STP effluent (-2.7???) and wash water from a domestic washing machine (-5.7???) were used to plot mixing lines between wastewater and native ground water. In general, wells with elevated NO3 concentrations fell along mixing lines between wastewater and background water on plots of ??11B against 1/B and Cl/B. Combined use of ??15N and ??11B in the study area was generally successful in

  16. The Magic Moment: Creating Color Harmony

    ERIC Educational Resources Information Center

    Bartges, Dan

    2009-01-01

    If there is a truly magic moment in art class, it must be when a student--of any age--attains a working knowledge of color's core principles. At that point, she or he becomes able to consistently create color harmony in any painting, regardless of the subject matter. From then on, that student gains greater confidence, can paint better pictures…

  17. What Is So Magic about Harry?

    ERIC Educational Resources Information Center

    Nelson, Cole; Nelson, Brooke

    2000-01-01

    Presents the comments of an 11-year-old and his mother regarding what is so magical about the Harry Potter series of books. Notes the child enjoyed the fantasy aspects and the animals in the books; and the mother appreciates the sheer fun of reading the books and that the characters show sensitivity and caring for each other. (RS)

  18. Promoting Reasoning through the Magic V Task

    ERIC Educational Resources Information Center

    Bragg, Leicha A.; Widjaja, Wanty; Loong, Esther Yook-Kin; Vale, Colleen; Herbert, Sandra

    2015-01-01

    Reasoning in mathematics plays a critical role in developing mathematical understandings. In this article, Bragg, Loong, Widjaja, Vale & Herbert explore an adaptation of the Magic V Task and how it was used in several classrooms to promote and develop reasoning skills.

  19. Constraints on Children's Judgments of Magical Causality

    ERIC Educational Resources Information Center

    Woolley, Jacqueline D.; Browne, Cheryl A.; Boerger, Elizabeth A.

    2006-01-01

    In 3 studies we addressed the operation of constraints on children's causal judgments. Our primary focus was whether children's beliefs about magical causality, specifically wishing, are constrained by features that govern the attribution of ordinary causality. In Experiment 1, children witnessed situations in which a confederate's wish appeared…

  20. It's Not Magic! Research on Developing Expertise

    ERIC Educational Resources Information Center

    Peskin, Joan

    2011-01-01

    In the past two decades, a large body of research has examined the differences between novices and experts in subject areas ranging from physics to poetry. Yet research on developing expertise has found no "magic bullet" in becoming an expert and has concluded that innate talent plays a less prominent role than previously imagined. Various studies…

  1. Where Is the Magic Out There?

    ERIC Educational Resources Information Center

    Halpern, Judy

    2002-01-01

    The Magic Suitcase provides workshops for young children and teachers across Ontario, using their own schoolyards to explore the wonders of nature and science. Literature is used to explain concepts and make the experience memorable. Workshops are also train teachers to integrate the outdoors into their regular program. Nine picture books used in…

  2. Magic, Morals and Health: Plus 40 Years

    ERIC Educational Resources Information Center

    Young, Michael; Valois, Robert F.

    2010-01-01

    In the article "Magic, Morals and Health" the reader is treated to Dr. Warren Johnson's thoughts about health and society, and the role of health educators. If one stays with Dr. Johnson's train of thought, one will find Dr. Johnson is concerned that: (1) A large segment of society tends to base at least some of their beliefs about health on…

  3. The Magic of Mini-Lessons

    ERIC Educational Resources Information Center

    Lombardo, Mary A.

    2006-01-01

    Making magic in the classroom or library media center is as simple as imitating what choreographers do. Just as they demonstrate and teach a dance routine a few steps at a time before asking the performers to put all the steps together for a presentation, many teachers find that breaking a unit of study into several parts, or mini-lessons, is a…

  4. Word Magic: Poetry as a Shared Adventure.

    ERIC Educational Resources Information Center

    McVitty, Walter, Ed.

    Written by teachers and poets, this book offers insights into the nature of poetry and the ways in which children can be taught to enjoy reading and writing poetry. The book contains the following articles: "Poetry and the Magic of Words," by Colin Thiele; "Poetry and the Child," by Charles Causley; "A Verse Along the Way," by Max Fatchen; "The…

  5. Shell corrections, magic numbers, and mean field

    SciTech Connect

    Denisov, V. Yu.

    2007-02-15

    It is shown that the positions of deep local minima of shell corrections associated with magic numbers in the region of superheavy nuclei depend on the parameters of the central and spin-orbit mean-field potentials. The accuracy of nuclear-mass predictions made within various models for superheavy nuclei is analyzed.

  6. ORNL's magic bullets: On target for health

    SciTech Connect

    Pearce, J.

    1993-01-01

    Magic bullets. That's how we've come to know a group of chemical compounds that have an uncanny ability to home in on particular targets within the body. Their [open quotes]magic[close quotes] is provided by chemically attached radioactive isotopes, labels made of small quantities or radioactive material that enable physicians to obtain detailed images of internal organs, deliver doses of radiation to specific destinations, and trace the movement of medications - all without picking up a scalpel. In recent years, a barrage of magic bullets has been fired from laboratories around the country, but because of their long and involved development process, relatively few have been tested in human patients, - fewer still have found commercial applications. Despite these odds, the researchers of ORNL's Nuclear Medicine Group have gained reputations as sharpshooters, thanks to four new magic bullets now in clinical testing - a radiolabeled antibody that targets colon cancer cells, a test agent for pancreas problems, and imaging agents for monitoring blood flow in the heart and detecting early signs of heart disease. A fifth agent that promises to help track the changes in brain chemistry resulting from Alzheimer's and related diseases is undergoing preclinical studies.

  7. Imagination and the Magic of Libraries.

    ERIC Educational Resources Information Center

    The Bookmark, 1990

    1990-01-01

    This issue of "The Bookmark" presents 20 articles focusing on the theme that libraries foster imagination. The articles are: (1) "Imagination and the Magic of Libraries" (Elizabeth S. Manion); (2) "Powerful Partners--Discovery and Democracy, An Interview with Cynthia Jenkins" (Anne E. Simon); (3) "Fostering Imagination in Children" (Susan Lehr);…

  8. Math in Your Classroom: Math Magic

    ERIC Educational Resources Information Center

    Naylor, Michael

    2005-01-01

    Mathematics truly is magical, especially for students with strong number sense and algebra skills. This paper describes a variety of mathematical surprises that will capture students' interest and motivate exploration of mathematical ideas. While the tricks themselves are fascinating, push students to think about the reasons why these stunning…

  9. A reduced population of CD103(+)CD11b(+) dendritic cells has a limited impact on oral Salmonella infection.

    PubMed

    Fernández-Santoscoy, María; Wenzel, Ulf Alexander; Persson, Emma; Yrlid, Ulf; Agace, William; Wick, Mary Jo

    2016-08-01

    CD103(+)CD11b(+) dendritic cells (DC) are the major migratory DC subset in the small intestine lamina propria (siLP) and their survival is dependent on the transcription factor interferon regulatory factor 4 (IRF4). Mice with a DC-specific deletion of irf4 (CD11c-cre.Irf4 mice) have reduced mucosal CD103(+)CD11b(+) DC and altered T cell differentiation to protein antigen. The influence of CD103(+)CD11b(+) DC on oral infection with the gastrointestinal pathogen Salmonella, however, is poorly understood and is investigated here. We show that, despite being infected with Salmonella, CD11c-cre.Irf4 mice (called Cre(+) mice) conserve the reduction in CD103(+)CD11b(+) DC observed in naive Cre(+) mice, particularly in the mesenteric lymph nodes (MLN) but also in the siLP at day 3 post infection. Moreover, Salmonella-infected Cre(+) mice have a similar bacterial burden in intestinal tissues (siLP, MLN and Peyer's patches) as well as the spleen compared to infected Cre(-) controls. The T cell compartment, including the frequency of IFN-γ and IL-17-producing T cells, is not altered in intestinal tissues of Salmonella-infected Cre(+) mice relative to infected Cre(-) controls. In addition, no difference between infected Cre(+) and Cre(-) mice was observed in either the concentration of IL-6 or IL-17 in whole tissue lysates of siLP, MLN or Peyer's patches or in the serum concentration of Salmonella-specific IgG and IgM. Overall the data suggest that the reduction of CD103(+)CD11b(+) DC in Cre(+) mice has little if any impact on Salmonella burden in infected tissues or eliciting effector functions important in host survival at later stages of the infection. PMID:27262930

  10. KEPLER AND GROUND-BASED TRANSITS OF THE EXO-NEPTUNE HAT-P-11b

    SciTech Connect

    Deming, Drake; Jackson, Brian; Jennings, Donald E.; Sada, Pedro V.; Peterson, Steven W.; Haase, Flynn; Bays, Kevin; Agol, Eric; Knutson, Heather A.

    2011-10-10

    We analyze 26 archival Kepler transits of the exo-Neptune HAT-P-11b, supplemented by ground-based transits observed in the blue (B band) and near-IR (J band). Both the planet and host star are smaller than previously believed; our analysis yields R{sub p} = 4.31 R{sub +} {+-} 0.06 R{sub +} and R{sub s} = 0.683 R{sub sun} {+-} 0.009 R{sub sun}, both about 3{sigma} smaller than the discovery values. Our ground-based transit data at wavelengths bracketing the Kepler bandpass serve to check the wavelength dependence of stellar limb darkening, and the J-band transit provides a precise and independent constraint on the transit duration. Both the limb darkening and transit duration from our ground-based data are consistent with the new Kepler values for the system parameters. Our smaller radius for the planet implies that its gaseous envelope can be less extensive than previously believed, being very similar to the H-He envelope of GJ 436b and Kepler-4b. HAT-P-11 is an active star, and signatures of star spot crossings are ubiquitous in the Kepler transit data. We develop and apply a methodology to correct the planetary radius for the presence of both crossed and uncrossed star spots. Star spot crossings are concentrated at phases -0.002 and +0.006. This is consistent with inferences from Rossiter-McLaughlin measurements that the planet transits nearly perpendicular to the stellar equator. We identify the dominant phases of star spot crossings with active latitudes on the star, and infer that the stellar rotational pole is inclined at about 12{sup 0} {+-} 5{sup 0} to the plane of the sky. We point out that precise transit measurements over long durations could in principle allow us to construct a stellar Butterfly diagram to probe the cyclic evolution of magnetic activity on this active K-dwarf star.

  11. Angle detector

    NASA Technical Reports Server (NTRS)

    Parra, G. T. (Inventor)

    1978-01-01

    An angle detector for determining a transducer's angular disposition to a capacitive pickup element is described. The transducer comprises a pendulum mounted inductive element moving past the capacitive pickup element. The capacitive pickup element divides the inductive element into two parts L sub 1 and L sub 2 which form the arms of one side of an a-c bridge. Two networks R sub 1 and R sub 2 having a plurality of binary weighted resistors and an equal number of digitally controlled switches for removing resistors from the networks form the arms of the other side of the a-c bridge. A binary counter, controlled by a phase detector, balances the bridge by adjusting the resistance of R sub 1 and R sub 2. The binary output of the counter is representative of the angle.

  12. Study of the neutron and proton capture reactions 10,11B(n, γ), 11B(p, γ), 14C(p, γ), and 15N(p, γ) at thermal and astrophysical energies

    NASA Astrophysics Data System (ADS)

    Dubovichenko, Sergey; Dzhazairov-Kakhramanov, Albert

    2014-07-01

    We have studied the neutron-capture reactions 10,11B(n, γ) and the role of the 11B(n, γ) reaction in seeding r-process nucleosynthesis. The possibility of the description of the available experimental data for cross-sections of the neutron capture reaction on 10B at thermal and astrophysical energies, taking into account the resonance at 475 keV, was considered within the framework of the modified potential cluster model (MPCM) with forbidden states (FS) and accounting for the resonance behavior of the scattering phase shifts. In the framework of the same model, the possibility of describing the available experimental data for the total cross-sections of the neutron radiative capture on 11B at thermal and astrophysical energies were considered with taking into account the 21 and 430 keV resonances. Description of the available experimental data on the total cross-sections and astrophysical S-factor of the radiative proton capture on 11B to the GS of 12C was treated at astrophysical energies. The possibility of description of the experimental data for the astrophysical S-factor of the radiative proton capture on 14C to the GS of 15N at astrophysical energies, and the radiative proton capture on 15N at the energies from 50 to 1500 keV was considered in the framework of the MPCM with the classification of the orbital states according to Young tableaux. It was shown that, on the basis of the M1 and the E1 transitions from different states of the p15N scattering to the GS of 16O in the p15N channel, it is quite succeed to explain general behavior of the S-factor in the considered energy range in the presence of two resonances.

  13. Relationship of Genetic Polymorphisms of Aldosterone Synthase Gene Cytochrome P450 11B2 and Mineralocorticoid Receptors with Coronary Artery Disease in Taiwan

    PubMed Central

    Chou, Chi-Hung; Ueng, Kwo-Chang; Yang, Shun-Fa; Wu, Chih-Hsien; Wang, Po-Hui

    2016-01-01

    The aldosterone synthase gene, cytochrome P450 11B2 (CYP11B2), and mineralocorticoid receptor (MR) genes have been reported to be associated with coronary artery disease (CAD). In this study, we investigated the association of single nucleotide polymorphisms (SNPs) of CYP11B2 (CYP11B2 T-344C) and MR (MR C3514G and MR C4582A) with CAD in Taiwanese. Six hundred and nine unrelated male and female subjects who received elective coronary angiography were recruited from Chung Shan Medical University Hospital. The enrolled subjects were those who had a positive noninvasive test. CYP11B2 T-344C, MR C3514G and MR C4582A were determined by polymerase chain reaction-restriction fragment length polymorphism. We found that women with CYP11B2 C/C had a higher risk of developing CAD. However, there were no significant differences in the genotype distributions of MR C3514G and MR C4582A between the women with and without CAD. In multivariate analysis, CYP11B2 T-344C was most significantly associated with CAD in Taiwanese women. In conclusions, CYP11B2 C/C was more significantly associated with the development of CAD than diabetes mellitus or hypertension. This implies that CYP11B2 C/C plays a more important role than some conventional risk factors in the development of CAD in Taiwanese women. PMID:26941570

  14. A patient with refractory testicular adrenal rest tumour in the setting of cyp11b1 deficiency congenital adrenal hyperplasia.

    PubMed

    Mirzaei, Mohammad Reza; Rezvanian, Hassan; Siavash, Mansour; Parham, Mahmoud; Mahzouni, Parvin

    2009-01-01

    Testicular adrenal rest tumour (TART) due to CYP11B1 deficiency is a very rare clinical finding. Only seven cases have been reported previously. Here, the case of a 19-year-old boy with classic CYP11B1 deficiency and large testicles refractory to medical treatment that led to orchidectomy is reported. The clinical and laboratory manifestations of this patient are discussed and compared with that of the previously reported cases. The patient presented with rapid body growth, precocious puberty, hypertension, recurrent hypokalaemic paralysis and testicular enlargement. The most important differential diagnosis of his latter presentation is Leydig cell tumour (LCT). It was found that positive family history of congenital adrenal hyperplasia (CAH), hypertension, bilaterality, hypokalaemia and multiple hypoechoic masses on ultrasonography of the testes are in favour of a diagnosis of TART. Conversely, high titres of tumour markers and presence of Reinke crystalloids are supportive of a diagnosis of LCT. PMID:21686875

  15. Infection-induced type I interferons activate CD11b on B-1 cells for subsequent lymph node accumulation

    PubMed Central

    Waffarn, Elizabeth E.; Hastey, Christine J.; Dixit, Neha; Choi, Youn Soo; Cherry, Simon; Kalinke, Ulrich; Simon, Scott I.; Baumgarth, Nicole

    2016-01-01

    Innate-like B-1a lymphocytes rapidly redistribute to regional mediastinal lymph nodes (MedLN) during influenza infection to generate protective IgM. Here we demonstrate that influenza infection-induced type I interferons directly stimulate body cavity B-1 cells and are a necessary signal required for B-1 cell accumulation in MedLN. Vascular mimetic flow chamber studies show that type I interferons increase ligand-mediated B-1 cell adhesion under shear stress by inducing high-affinity conformation shifts of surface-expressed integrins. In vivo trafficking experiments identify CD11b as the non-redundant, interferon-activated integrin required for B-1 cell accumulation in MedLN. Thus CD11b on B-1 cells senses infection-induced innate signals and facilitates their rapid sequester into secondary lymphoid tissues, thereby regulating the accumulation of polyreactive IgM producers at sites of infection. PMID:26612263

  16. Magical thinking and memory: distinctiveness effect for tv commercials with magical content.

    PubMed

    Subbotsky, Eugene; Mathews, Jayne

    2011-10-01

    The aim of this study was to examine whether memorizing advertised products of television advertisements with magical effects (i.e., talking animals, inanimate objects which turn into humans, objects that appear from thin air or instantly turn into other objects) is easier than memorizing products of advertisements without such effects, by testing immediate and delayed retention. Adolescents and adults viewed two films containing television advertisements and were asked to recall and recognize the films' characters, events, and advertised products. Film 1 included magical effects, but Film 2 did not. On a free-recall test, no differences in the number of items recalled were noted for the two films. On the immediate recognition test, adolescents, but not adults, showed significantly better recognition for the magical than the nonmagical film. When this test was repeated two weeks later, results were reversed: adults, but not adolescents, recognized a significantly larger number of items from the magical film than the nonmagical one. These results are interpreted to accentuate the role of magical thinking in cognitive processes. PMID:22238845

  17. New results on the Trojan Horse Method applied to the {sup 10,11}B+p reactions

    SciTech Connect

    Spitaleri, C.; Romano, S.; Lamia, L.; Puglia, S. M. R.; Cherubini, S.; Crucilla, V.; Gulino, M.; La Cognata, M.; Pizzone, R. G.; Rapisarda, G. G.; Sergi, M. L.; Tudisco, S.; Tumino, A.; Del Szanto, M. G.; Carlin, N.; Munhoz, M. G.; Szanto de Toledo, A.; Neto, R. Liguori; De Moura, M. M.; Souza, F. A.

    2009-05-04

    Light elements lithium, beryllium and boron (LiBeB) were used in the last years as 'possible probes' for stellar structure. They are mainly destroyed by (p,{alpha}) reactions and cross section measurements for such channels are then needed. In this work a resume of the recent results, obtained via Trojan Horse Method, about the {sup 11}B(p,{alpha}{sub 0}){sup 8}Be and {sup 10}B(p,{alpha}){sup 7}Be reactions are shown.

  18. In silico structure-function analysis of pathological variation in the HSD11B2 gene sequence.

    PubMed

    Manning, Jonathan R; Bailey, Matthew A; Soares, Dinesh C; Dunbar, Donald R; Mullins, John J

    2010-08-01

    11beta-Hydroxysteroid dehydrogenase type 2 (11betaHSD2) is a short-chain dehydrogenase/reductase (SDR) responsible for inactivating cortisol and preventing its binding to the mineralocorticoid receptor (MR). Nonfunctional mutations in HSD11B2, the gene encoding 11betaHSD2, cause the hypertensive syndrome of apparent mineralocorticoid excess (AME). Like other such Mendelian disorders, AME is rare but has nevertheless helped to illuminate principles fundamental to the regulation of blood pressure. Furthermore, polymorphisms in HSD11B2 have been associated with salt sensitivity, a major risk factor for cardiovascular mortality. It is therefore highly likely that sequence variation in HSD11B2, having subtle functional ramifications, will affect blood pressure in the wider population. In this study, a three-dimensional homology model of 11betaHSD2 was created and used to hypothesize the functional consequences in terms of protein structure of published mutations in HSD11B2. This approach underscored the strong genotype-phenotype correlation of AME: severe forms of the disease, associated with little in vivo enzyme activity, arise from mutations occurring in invariant alignment positions. These were predicted to exert gross structural changes in the protein. In contrast, those mutations causing a mild clinical phenotype were in less conserved regions of the protein that were predicted to be relatively more tolerant to substitution. Finally, a number of pathogenic mutations are shown to be associated with regions predicted to participate in dimer formation, and in protein stabilization, which may therefore suggest molecular mechanisms of disease. PMID:20571110

  19. Complete and Incomplete Fusion Competition in 11B-INDUCED Fission Reactions on 197Au at the Intermediate Energy

    NASA Astrophysics Data System (ADS)

    Demekhina, N. A.; Karapetyan, G. S.; Balabekyan, A. R.

    2015-06-01

    Above Coulomb barrier cross sections of fission fragment production were measured in reactions of 11B with 197Au target. Induced-activity method was used for measurement the fission decay channel of the composite nuclei. Systematic of the fission fragment charge and mass distributions was used for fission cross section calculation. Fission fraction of the composite nuclei decay was compared with PACE-4 mode calculations. Estimated suppression for fission fraction followed the complete fusion have been obtained 35%.

  20. IFN-γ differentially regulates subsets of Gr-1(+)CD11b(+) myeloid cells in chronic inflammation.

    PubMed

    Zhan, Xiaoxia; Fang, Yimin; Hu, Shengfeng; Wu, Yongjian; Yang, Kun; Liao, Chunxin; Zhang, Yuanqing; Huang, Xi; Wu, Minhao

    2015-08-01

    During chronic inflammation, prolonged over-reactive immune response may lead to tissue destruction, while immune suppression hinders tissue repair and pathogen elimination. Therefore, precise regulation of the immune response is needed to avoid immuno-pathology. Interferon-gamma (IFN-γ) is widely used in clinical treatment of inflammatory diseases. However, the underlying mechanism remains unclear. Here, we evaluated the role of IFN-γ on CD11b(+)Gr-1(+) myeloid cell differentiation and function, using a heat-killed Mycobacterium bovis BCG-induced chronic inflammation model. After challenge with heat-killed BCG, two subpopulations of CD11b(+)Gr-1(+) myeloid cells were generated in the mouse spleen. Phenotypical, morphological and functional analysis indicated that the CD11b(+)Gr-1(high) Ly6G(high) Ly6C(low) subset was neutrophil-like myeloid-derived inducer cells (N-MDICs), which promoted T cell activation, while the other subset was CD11b(+)Gr-1(low) Ly6G(neg) Ly6C(high) monocyte-like myeloid-derived suppressor cells (M-MDSCs) that displayed extensive suppressor function. IFN-γ treatment dampened N-MDICs-mediated T cell activation through up-regulating T cell suppressive mediators, reactive oxygen species (ROS) and arginase I. While for M-MDSCs, IFN-γ reduced their suppressing activity by decreasing the arginase activity. Our study provides evidence that IFN-γ balances the over-reactive vs compromised immune response through different regulation of distinct myeloid subsets, and therefore displays significant therapeutic potential for effective immuno-therapy of chronic inflammatory diseases. PMID:26021804

  1. Identification of seven novel CYP11B1 gene mutations in Chinese patients with 11β-hydroxylase deficiency.

    PubMed

    Wang, Xiaojing; Nie, Min; Lu, Lin; Tong, Anli; Chen, Shi; Lu, Zhaolin

    2015-08-01

    Steroid 11β-hydroxylase deficiency (11β-OHD), one of common cause of congenital adrenal hyperplasia (CAH), is an autosomal recessive disorder characterized by virilization, precocious pseudo-puberty, and hypertension. It is caused by CYP11B1 gene mutation. We performed molecular genetic analysis of the CYP11B1 gene in six patients with preliminary clinical diagnosis of 11β-OHD and four patients identified as potential 11β-OHD from a CAH cohort in which CYP21A2 gene mutations consecutively screened. Seven novel CYP11B1 mutations, including p.R454H, p.Q472P, p.Q155X, p.K173X, IVS2-1G>A, R454A fs 573X, and g.2704_g.3154del, and six previously described mutations (p.P94L, p.G267S, p.G379V, p.R448H, p.R454C and p.R141X) were identified. These mutations mainly clustered in exons 3 and 8. Eight of twenty alleles carried mutations occurring at the Arg454 position, which is a mutational hot spot for Han Chinese. The pathogenic nature of novel p.R454H mutation was predicted by protein sequence alignment and in silico analysis. All the identified mutations were responsible for the clinical features observed in these ten unrelated Chinese patients. This study expands the CYP11B1 mutation spectrum and provides evidence for prenatal diagnosis and genetic counseling. Genetic analysis is an alternative approach to help clinicians confirm uncertain 11β-OHD diagnosis, facilitating reasonable steroid replacement. PMID:25911436

  2. In silico structure-function analysis of pathological variation in the HSD11B2 gene sequence

    PubMed Central

    Bailey, Matthew A.; Soares, Dinesh C.; Dunbar, Donald R.; Mullins, John J.

    2010-01-01

    11β-Hydroxysteroid dehydrogenase type 2 (11βHSD2) is a short-chain dehydrogenase/reductase (SDR) responsible for inactivating cortisol and preventing its binding to the mineralocorticoid receptor (MR). Nonfunctional mutations in HSD11B2, the gene encoding 11βHSD2, cause the hypertensive syndrome of apparent mineralocorticoid excess (AME). Like other such Mendelian disorders, AME is rare but has nevertheless helped to illuminate principles fundamental to the regulation of blood pressure. Furthermore, polymorphisms in HSD11B2 have been associated with salt sensitivity, a major risk factor for cardiovascular mortality. It is therefore highly likely that sequence variation in HSD11B2, having subtle functional ramifications, will affect blood pressure in the wider population. In this study, a three-dimensional homology model of 11βHSD2 was created and used to hypothesize the functional consequences in terms of protein structure of published mutations in HSD11B2. This approach underscored the strong genotype-phenotype correlation of AME: severe forms of the disease, associated with little in vivo enzyme activity, arise from mutations occurring in invariant alignment positions. These were predicted to exert gross structural changes in the protein. In contrast, those mutations causing a mild clinical phenotype were in less conserved regions of the protein that were predicted to be relatively more tolerant to substitution. Finally, a number of pathogenic mutations are shown to be associated with regions predicted to participate in dimer formation, and in protein stabilization, which may therefore suggest molecular mechanisms of disease. PMID:20571110

  3. Oriental magic mirrors and the Laplacian image

    NASA Astrophysics Data System (ADS)

    Berry, M. V.

    2006-01-01

    The pattern embossed on the back of an oriental magic mirror appears in the patch of light projected onto a screen from its apparently featureless reflecting surface. In reality, the embossed pattern is reproduced in low relief on the front, and analysis shows that the projected image results from pre-focal ray deviation. In this interesting regime of geometrical optics, the image intensity is given simply by the Laplacian of the height function of the relief. For patterns consisting of steps, this predicts a characteristic effect, confirmed by observation: the image of each step exhibits a bright line on the low side and a dark line on the high side. Laplacian-image analysis of a magic-mirror image indicates that steps on the reflecting surface are about 400 nm high and laterally smoothed by about 0.5 mm.

  4. Small codes for magic state distillation

    NASA Astrophysics Data System (ADS)

    Howard, Mark; Dawkins, Hillary

    2016-03-01

    Magic state distillation is a critical component in leading proposals for fault-tolerant quantum computation. Relatively little is known, however, about how to construct a magic state distillation routine or, more specifically, which stabilizer codes are suitable for the task. While transversality of a non-Clifford gate within a code often leads to efficient distillation routines, it appears to not be a necessary condition. Here we have examined a number of small stabilizer codes and highlight a handful of which displaying interesting, albeit inefficient, distillation behaviour. Many of these distill noisy states right up to the boundary of the known undististillable region, while some distill toward non-stabilizer states that have not previously been considered.

  5. MAGIC: Model and Graphic Information Converter

    NASA Technical Reports Server (NTRS)

    Herbert, W. C.

    2009-01-01

    MAGIC is a software tool capable of converting highly detailed 3D models from an open, standard format, VRML 2.0/97, into the proprietary DTS file format used by the Torque Game Engine from GarageGames. MAGIC is used to convert 3D simulations from authoritative sources into the data needed to run the simulations in NASA's Distributed Observer Network. The Distributed Observer Network (DON) is a simulation presentation tool built by NASA to facilitate the simulation sharing requirements of the Data Presentation and Visualization effort within the Constellation Program. DON is built on top of the Torque Game Engine (TGE) and has chosen TGE's Dynamix Three Space (DTS) file format to represent 3D objects within simulations.

  6. Dynamic polarizabilities and magic wavelengths for dysprosium

    SciTech Connect

    Dzuba, V. A.; Flambaum, V. V.; Lev, Benjamin L.

    2011-03-15

    We theoretically study dynamic scalar polarizabilities of the ground and select long-lived excited states of dysprosium, a highly magnetic atom recently laser cooled and trapped. We demonstrate that there is a set of magic wavelengths of the unpolarized lattice laser field for each pair of states, which includes the ground state and one of these excited states. At these wavelengths, the energy shift due to laser field is the same for both states, which can be useful for resolved sideband cooling on narrow transitions and precision spectroscopy. We present an analytical formula that, near resonances, allows for the determination of approximate values of the magic wavelengths without calculating the dynamic polarizabilities of the excited states.

  7. Magical arts: the poetics of play.

    PubMed

    Jacobus, Mary

    2005-01-01

    The paper argues that links between play and magic in British Object Relations point to the persistence of aesthetic concerns within psychoanalysis. Magical thinking is present in British Object Relations psychoanalysis from its beginnings in Klein's play technique and early aesthetic writings, surfacing elsewhere in Susan Isaac's educational experiments and her theories of metaphor. Marion Milner's clinical account of the overlapping areas of illusion and symbol-formation in a boy's war-games link the primitive rituals of Frazer's "The Golden Bough" with her patient's creativity. In Winnicott's concept of the transitional object, the theory of play achieves its apotheosis as a diffusive theory of culture or "private madness," and as a paradigm for psychoanalysis itself. Tracing the non-positivistic, mystical, and poetical elements in British Object Relations underlines the extent to which aesthetics is not just entangled with psychoanalysis, but constitutive of it in its mid-twentieth century manifestations. PMID:21874676

  8. The heteromeric transcription factor GABP activates the ITGAM/CD11b promoter and induces myeloid differentiation.

    PubMed

    Ripperger, Tim; Manukjan, Georgi; Meyer, Johann; Wolter, Sabine; Schambach, Axel; Bohne, Jens; Modlich, Ute; Li, Zhixiong; Skawran, Britta; Schlegelberger, Brigitte; Steinemann, Doris

    2015-09-01

    The heteromeric transcription factor GA-binding protein (GABP) consists of two subunits, the alpha subunit (GABPA) carrying the DNA-binding ETS domain, and the beta subunit (GABPB1) harbouring the transcriptional activation domain. GABP is involved in haematopoietic stem cell maintenance and differentiation of myeloid and lymphoid lineages in mice. To elucidate the molecular function of GABP in human haematopoiesis, the present study addressed effects of ectopic overexpression of GABP focussing on the myeloid compartment. Combined overexpression of GABPA and GABPB1 caused a proliferation block in cell lines and drastically reduced the colony-forming capacity of murine lineage-negative cells. Impaired proliferation resulted from perturbed cellular cycling and induction of myeloid differentiation shown by surface markers and myelomonocytic morphology of U937 cells. Depending on the dosage and functional integrity of GABP, ITGAM expression was induced. ITGAM encodes CD11b, the alpha subunit of integrin Mac-1, whose beta subunit, ITGB2/CD18, was already described to be regulated by GABP. Finally, Shield1-dependent proteotuning, luciferase reporter assays and chromatin immunoprecipitation showed that GABP activates the ITGAM/CD11b promoter via three binding sites close to the translational start site. In conclusion, the present study supports the crucial role of GABP in myeloid cell differentiation and identified ITGAM/CD11b as a novel GABP target gene. PMID:26170143

  9. Detailed study for 16O → 12C + α and 12C → 11B + p spectroscopic factors

    NASA Astrophysics Data System (ADS)

    Hamada, Sh.; Burtebayev, N.; Amangeldi, N.

    2014-10-01

    We have measured the angular distributions for 16O elastically scattered on 12C nuclei at energy 28 MeV and also for 12C ion beam elastically scattered on 11B target nuclei at energy 18 MeV. These measurements were performed in the cyclotron DC-60 INP NNC RK. Calculations were performed using both empirical Woods-Saxon and double folding optical model potentials. Both elastic scattering and transfer reaction were taken into consideration. We have extracted the spectroscopic factors for the configurations 16O → 12C + α and 12C → 11B + p and compared them with other calculated or extracted values at different energies from literature. The extracted spectroscopic factor for the configuration 12C → 11B + p from the current work is in the range 2.7-3.1, which is very close to Cohen-Kurath prediction. While for the configuration 16O → 12C + α, spectroscopic factors show fluctuation with energy which could be due to the well-known resonant-like behavior observed in 16O + 12C excitation function.

  10. Antigen-specific cytotoxic T lymphocytes target airway CD103+ and CD11b+ dendritic cells to suppress allergic inflammation.

    PubMed

    Daniels, N J; Hyde, E; Ghosh, S; Seo, K; Price, K M; Hoshino, K; Kaisho, T; Okada, T; Ronchese, F

    2016-01-01

    Allergic airway inflammation is driven by the recognition of inhaled allergen by T helper type 2 (Th2) cells in the airway and lung. Allergen-specific cytotoxic T lymphocytes (CTLs) can strongly reduce airway inflammation, however, the mechanism of their inhibitory activity is not fully defined. We used mouse models to show that allergen-specific CTLs reduced early cytokine production by Th2 cells in lung, and their subsequent accumulation and production of interleukin (IL)-4 and IL-13. In addition, treatment with specific CTLs also increased the proportion of caspase(+) dendritic cells (DCs) in mediastinal lymph node (MLN), and decreased the numbers of CD103(+) and CD11b(+) DCs in the lung. This decrease required expression of the cytotoxic mediator perforin in CTLs and of the appropriate MHC-antigen ligand on DCs, suggesting that direct CTL-DC contact was necessary. Lastly, lung imaging experiments revealed that in airway-challenged mice XCR1-GFP(+) DCs, corresponding to the CD103(+) DC subset, and XCR1-GFP(-) CD11c(+) cells, which include CD11b(+) DCs and alveolar macrophages, both clustered in the areas surrounding the small airways and were closely associated with allergen-specific CTLs. Thus, allergen-specific CTLs reduce allergic airway inflammation by depleting CD103(+) and CD11b(+) DC populations in the lung, and may constitute a mechanism through which allergic immune responses are regulated. PMID:26104914

  11. Development of non-viral vehicles for targeted gene transfer into microglia via the integrin receptor CD11b

    PubMed Central

    Smolny, Markus; Rogers, Mary-Louise; Shafton, Anthony; Rush, Robert A.; Stebbing, Martin J.

    2014-01-01

    Microglial activation is a central event in neurodegeneration. Novel technologies are sought for that specifically manipulate microglial function in order to delineate their role in onset and progression of neuropathologies. We investigated for the first time whether non-viral gene delivery based on polyethyleneglycol–polyethyleneimine conjugated to the monoclonal anti-CD11b antibody OX42 (“OX42-immunogene”) could be used to specifically target microglia. We first conducted immunofluorescence studies with the OX42 antibody and identified its microglial integrin receptor CD11b as a potential target for receptor-mediated gene transfer based on its cellular specificity in mixed glia culture and in vivo and found that the OX42 antibody is rapidly internalized and trafficked to acidic organelles in absence of activation of the respiratory burst. We then performed transfection experiments with the OX42-immunogene in vitro and in rat brain showing that the OX42-immunogene although internalized was degraded intracellularly and did not cause substantial gene expression in microglia. Investigation of specific barriers to microglial gene transfer revealed that aggregated OX42-immunogene polyplexes stimulated the respiratory burst that likely involved Fcγ-receptors. Transfections in the presence of the endosomolytic agent chloroquine improved transfection efficiency indicating that endosomal escape may be limited. This study identifies CD11b as an entry point for antibody-mediated gene transfer into microglia and takes important steps toward the further development of OX42-immunogenes. PMID:25346658

  12. Investigation on Qiong yao shen shu (Qiongyao's Magical Book).

    PubMed

    Huang, L

    1999-01-01

    Written in about the period of late Yuan to early Ming dynasties, Qiongyao's Magical Book is attributed to a Taoist who was also conversant with acupunture art. By investigation, it is found that there are, at least, three books carrying the same title of Qiongyao's Magical Book, including a 3 volume Qiongyao's Magical Book now lost; a 3 - volume Qiongyao's Magical Book of Discovery (also called The Acupuncture Classic of Qiongyao the Immortal printed in the Ming dynasty, which is entirely different from the previous one and is an apocrypha; and a 4 - volume Qiongyao's Magical Book printed in the Qing dynasty also called Qiongyao's Great Collections of Magical Books wiich is a mixture of authentic and apocryphal texts in which 2 medical books irrelevant to the original are attached to the end of volume 3, with supplements by later writers intermingled in other volumes. PMID:11623790

  13. Watching films with magical content facilitates creativity in children.

    PubMed

    Subbotsky, Eugene; Hysted, Claire; Jones, Nicola

    2010-08-01

    Two experiments examined the possible link between magical thinking and creativity in preschool children. In Exp. 1, 4- and 6-yr.-old children were shown a film with either a magical or nonmagical theme. Results indicated that the mean scores of children shown the magical film was significantly higher than that of children watching the nonmagical film on the majority of subsequent creativity tests for both age groups. This trend was also found for 6-yr.-olds' drawings of impossible items. In Exp. 2, Exp. 1 was replicated successfully with 6- and 8-yr.-old children. Exposing children to a film with a magical theme did not affect their beliefs about magic. The results were interpreted to accentuate the role of magical thinking in children's cognitive development. Classroom implications of the results were also discussed. PMID:21058605

  14. Inactivation of CD11b in a mouse transgenic model protects against sepsis-induced lung PMN infiltration and vascular injury.

    PubMed

    Gao, Xiao-Pei; Liu, Qinghui; Broman, Michael; Predescu, Dan; Frey, Randall S; Malik, Asrar B

    2005-04-14

    To inactivate chronically the beta2-integrin CD11b (Mac-1), we made a transgenic model in mice in which we expressed the CD11b antagonist polypeptide neutrophil inhibitory factor (NIF). Using these mice, we determined the in vivo effects of CD11b inactivation on polymorphonuclear leukocyte (PMN) function and acute lung injury (ALI) induced by Escherichia coli septicemia. In wild-type PMNs, CD11b expression was induced within 1 h after E. coli challenge, whereas this response was significantly reduced in NIF(+/+) PMNs. Coimmunoprecipitation studies showed that NIF associated with CD11b in NIF(+/+) PMNs. To validate the effectiveness of CD11b blockade, we compared PMN function in NIF(+/+) and Mac-1-deficient (Mac-1(-/-)) mice. Adhesion of both Mac-1(-/-) and NIF(+/+) PMNs to endothelial cells in response to LPS was reduced in both types of PMNs and fully blocked only by the addition of anti-CD11a monoclonal antibody. This finding is indicative of intact CD11a function in the NIF(+/+) PMNs but the blockade of CD11b function. CD11b inactivation in NIF(+/+) mice interfered with lung PMN infiltration induced by E. coli and prevented the increase in lung microvessel permeability and edema formation, with most of the protection seen in the 1-h period after the E. coli. Thus our results demonstrate that CD11b plays a crucial role in mediating lung PMN sequestration and vascular injury in the early phase of gram-negative septicemia. The NIF(+/+) mouse model, in which CD11b is inactivated by binding to NIF, is a potentially useful model for in vivo assessment of the role of PMN CD11b in the mechanism of vascular inflammation. PMID:15831844

  15. Immunoconjugates: Magic Bullets for Cancer Therapy?

    NASA Technical Reports Server (NTRS)

    Passeri, Daniel R.; Spiegel, Jack

    1993-01-01

    Conjugating cytotoxic agents to antibodies allows for site-specific delivery of the agent to tumor cells and should provide increased efficacy and reduced non-specific toxicity. These site-specific cytotoxic agents are known as immunoconjugates or 'magic bullets' and have demonstrated great promise as therapeutic agents for cancer and other diseases. The historical developments and future potential of this new approach to cancer therapy are reviewed.

  16. [Suicide under the influence of "magic mushrooms"].

    PubMed

    Müller, Katja; Püschel, Klaus; Iwersen-Bergmann, Stefanie

    2013-01-01

    Psilocybin/psilocin from so-called psychoactive mushrooms causes hallucinogenic effects. Especially for people with mental or psychiatric disorders ingestion of magic mushrooms may result in horror trips combined with the intention of self-destruction and suicidal thoughts. Automutilation after consumption of hallucinogenic mushrooms has already been described. Our case report demonstrates the suicide of a man by self-inflicted cut and stab injuries. A causal connection between suicidal behaviour and previous ingestion of psychoactive mushrooms is discussed. PMID:23878898

  17. Collaboration in the Magic Tree House

    ERIC Educational Resources Information Center

    Berner, Jane; Minser, Sabrina; Presser, Helen Burkart

    2008-01-01

    The Magic Tree House series is a collection of books by Mary Pope Osborne, each built around a time and place of high interest to young children, with an underlying story that makes children want to read the next book in the series to find out what is going to happen. Here, the authors describe the development of a two-week reading program for…

  18. Pulsar observations with the MAGIC telescopes

    NASA Astrophysics Data System (ADS)

    Fidalgo, David

    2016-07-01

    The vast majority of spectra of gamma-ray pulsars exhibit an exponential cut-off at a few GeV, as seen by the Large Area Telescope (LAT) on board of the Fermi satellite. Due to this cut-off, current Imaging Atmospheric Cherenkov Telescopes (IACTs) with an energy threshold as low as 30 GeV, struggle to detect pulsars. So far, emission above 50 GeV has been confirmed only for the Crab and Vela pulsars. In the case of the former, the spectrum even extends up to about 1 TeV firmly revealing a second emission component. To further understand the emission mechanism of gamma-ray pulsars, the MAGIC collaboration continues the search of pulsars above 50 GeV. In this talk we report on recent results on the Crab and Geminga Pulsar obtained with the MAGIC telescopes, including the analysis of data taken with a new trigger system lowering the energy threshold of the MAGIC telescopes.

  19. Mathematical Construction of Magic Squares Utilizing Base-N Arithmetic

    ERIC Educational Resources Information Center

    O'Brien, Thomas D.

    2006-01-01

    Magic squares have been of interest as a source of recreation for over 4,500 years. A magic square consists of a square array of n[squared] positive and distinct integers arranged so that the sum of any column, row, or main diagonal is the same. In particular, an array of consecutive integers from 1 to n[squared] forming an nxn magic square is…

  20. Compact Magic-T using microstrip-slotline transitions

    NASA Technical Reports Server (NTRS)

    U-Yen, Kongpop (Inventor); Wollack, Edward J. (Inventor); Doiron, Terence (Inventor); Moseley, Samuel H. (Inventor)

    2010-01-01

    The design of a compact low-loss Magic-T is described. The planar Magic-T incorporates a compact microstrip-slotline tee junction and small microstrip-slotline transition area to reduce slotline radiation. The Magic-T produces broadband in-phase and out-of-phase power combiner/divider responses, has low in-band insertion loss, and small in-band phase and amplitude imbalance.