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Sample records for proton nmr spectra

  1. Handbook of proton-NMR spectra and data index

    CERN Document Server

    Asahi Research Center Co, Ltd

    2013-01-01

    Handbook of Proton-NMR Spectra and Data: Index to Volumes 1-10 compiles four types of indexes used in charting the proton-NMR spectral database -Chemical Name Index, Molecular Formula Index, Substructure Index, and Chemical Shift Index. The Chemical Name Index compiles all chemical names in alphabetical order, followed by a spectrum number. When the desired organic compound cannot be found in the Chemical Name Index or its nomenclature is unclear, it becomes necessary to look for a compound by means of its molecular formula, hence the Molecular Formula Index. A unique notation system for repre

  2. Anatomising proton NMR spectra with pure shift 2D J-spectroscopy: A cautionary tale

    Science.gov (United States)

    Kiraly, Peter; Foroozandeh, Mohammadali; Nilsson, Mathias; Morris, Gareth A.

    2017-09-01

    Analysis of proton NMR spectra has been a key tool in structure determination for over 60 years. A classic tool is 2D J-spectroscopy, but common problems are the difficulty of obtaining the absorption mode lineshapes needed for accurate results, and the need for a 45° shear of the final 2D spectrum. A novel 2D NMR method is reported here that allows straightforward determination of homonuclear couplings, using a modified version of the PSYCHE method to suppress couplings in the direct dimension. The method illustrates the need for care when combining pure shift data acquisition with multiple pulse methods.

  3. Towards automatic metabolomic profiling of high-resolution one-dimensional proton NMR spectra

    Energy Technology Data Exchange (ETDEWEB)

    Mercier, Pascal; Lewis, Michael J.; Chang, David, E-mail: dchang@chenomx.com [Chenomx Inc (Canada); Baker, David [Pfizer Inc (United States); Wishart, David S. [University of Alberta, Department of Computing Science and Biological Sciences (Canada)

    2011-04-15

    Nuclear magnetic resonance (NMR) and Mass Spectroscopy (MS) are the two most common spectroscopic analytical techniques employed in metabolomics. The large spectral datasets generated by NMR and MS are often analyzed using data reduction techniques like Principal Component Analysis (PCA). Although rapid, these methods are susceptible to solvent and matrix effects, high rates of false positives, lack of reproducibility and limited data transferability from one platform to the next. Given these limitations, a growing trend in both NMR and MS-based metabolomics is towards targeted profiling or 'quantitative' metabolomics, wherein compounds are identified and quantified via spectral fitting prior to any statistical analysis. Despite the obvious advantages of this method, targeted profiling is hindered by the time required to perform manual or computer-assisted spectral fitting. In an effort to increase data analysis throughput for NMR-based metabolomics, we have developed an automatic method for identifying and quantifying metabolites in one-dimensional (1D) proton NMR spectra. This new algorithm is capable of using carefully constructed reference spectra and optimizing thousands of variables to reconstruct experimental NMR spectra of biofluids using rules and concepts derived from physical chemistry and NMR theory. The automated profiling program has been tested against spectra of synthetic mixtures as well as biological spectra of urine, serum and cerebral spinal fluid (CSF). Our results indicate that the algorithm can correctly identify compounds with high fidelity in each biofluid sample (except for urine). Furthermore, the metabolite concentrations exhibit a very high correlation with both simulated and manually-detected values.

  4. Towards automatic metabolomic profiling of high-resolution one-dimensional proton NMR spectra

    International Nuclear Information System (INIS)

    Mercier, Pascal; Lewis, Michael J.; Chang, David; Baker, David; Wishart, David S.

    2011-01-01

    Nuclear magnetic resonance (NMR) and Mass Spectroscopy (MS) are the two most common spectroscopic analytical techniques employed in metabolomics. The large spectral datasets generated by NMR and MS are often analyzed using data reduction techniques like Principal Component Analysis (PCA). Although rapid, these methods are susceptible to solvent and matrix effects, high rates of false positives, lack of reproducibility and limited data transferability from one platform to the next. Given these limitations, a growing trend in both NMR and MS-based metabolomics is towards targeted profiling or “quantitative” metabolomics, wherein compounds are identified and quantified via spectral fitting prior to any statistical analysis. Despite the obvious advantages of this method, targeted profiling is hindered by the time required to perform manual or computer-assisted spectral fitting. In an effort to increase data analysis throughput for NMR-based metabolomics, we have developed an automatic method for identifying and quantifying metabolites in one-dimensional (1D) proton NMR spectra. This new algorithm is capable of using carefully constructed reference spectra and optimizing thousands of variables to reconstruct experimental NMR spectra of biofluids using rules and concepts derived from physical chemistry and NMR theory. The automated profiling program has been tested against spectra of synthetic mixtures as well as biological spectra of urine, serum and cerebral spinal fluid (CSF). Our results indicate that the algorithm can correctly identify compounds with high fidelity in each biofluid sample (except for urine). Furthermore, the metabolite concentrations exhibit a very high correlation with both simulated and manually-detected values.

  5. Conformation of antifreeze glycoproteins as determined from conformational energy calculations and fully assigned proton NMR spectra

    International Nuclear Information System (INIS)

    Bush, C.A.; Rao, B.N.N.

    1986-01-01

    The 1 H NMR spectra of AFGP's ranging in molecular weight from 2600 to 30,000 Daltons isolated from several different species of polar fish have been measured. The spectrum of AFGP 1-4 from Pagothenia borchgrevinki with an average of 30 repeating subunits has a single resonance for each proton of the glycotripeptide repeating unit, (ala-[gal-(β-1→3) galNAc-(α--O-]thr-ala)/sub n/. Its 1 H NMR spectrum including resonances of the amide protons has been completely assigned. Coupling constants and nuclear Overhauser enhancements (n.O.e.) between protons on distant residues imply conformational order. The 2600 dalton molecular weight glycopeptides (AFGP-8) have pro in place of ala at certain specific points in the sequence and AFGP-8R of Eleginus gracilis has arg in place of one thr. The resonances of pro and arg were assigned by decoupling. The resonances of the carboxy and amino terminals have distinct chemical shifts and were assigned in AFGP-8 of Boreogadus saida by titration. n.O.e. between α--protons and amide protons of the adjacent residue (sequential n.O.e.) were used in assignments of additional resonances and to assign the distinctive resonances of thr followed by pro. Conformational energy calculations on the repeating glycotripeptide subunit of AFGP show that the α--glucosidic linkage has a fixed conformation while the β--linkage is less rigid. A conformational model for AFGP 1-4, which is based on the calculations has the peptide in an extended left-handed helix with three residues per turn similar to polyproline II. The model is consistent with CD data, amide proton coupling constants, temperature dependence of amide proton chemical shifts

  6. Relativistic force field: parametric computations of proton-proton coupling constants in (1)H NMR spectra.

    Science.gov (United States)

    Kutateladze, Andrei G; Mukhina, Olga A

    2014-09-05

    Spin-spin coupling constants in (1)H NMR carry a wealth of structural information and offer a powerful tool for deciphering molecular structures. However, accurate ab initio or DFT calculations of spin-spin coupling constants have been very challenging and expensive. Scaling of (easy) Fermi contacts, fc, especially in the context of recent findings by Bally and Rablen (Bally, T.; Rablen, P. R. J. Org. Chem. 2011, 76, 4818), offers a framework for achieving practical evaluation of spin-spin coupling constants. We report a faster and more precise parametrization approach utilizing a new basis set for hydrogen atoms optimized in conjunction with (i) inexpensive B3LYP/6-31G(d) molecular geometries, (ii) inexpensive 4-31G basis set for carbon atoms in fc calculations, and (iii) individual parametrization for different atom types/hybridizations, not unlike a force field in molecular mechanics, but designed for the fc's. With the training set of 608 experimental constants we achieved rmsd <0.19 Hz. The methodology performs very well as we illustrate with a set of complex organic natural products, including strychnine (rmsd 0.19 Hz), morphine (rmsd 0.24 Hz), etc. This precision is achieved with much shorter computational times: accurate spin-spin coupling constants for the two conformers of strychnine were computed in parallel on two 16-core nodes of a Linux cluster within 10 min.

  7. New insight into hydration and aging mechanisms of paper by the line shape analysis of proton NMR spectra

    International Nuclear Information System (INIS)

    Mallamace, D.; Vasi, S.; Missori, M.; Corsaro, C.

    2016-01-01

    The action of water within biological systems is strictly linked either with their physical chemical properties and with their functions. Cellulose is one of the most studied biopolymers due to its biological importance and its wide use in manufactured products. Among them, paper is mainly constituted by an almost equimolar ratio of cellulose and water. Therefore the study of the behavior of water within pristine and aged paper samples can help to shed light on the degradation mechanisms that irremediably act over time and spoil paper. In this work we present Nuclear Magnetic Resonance (NMR) experiments on modern paper samples made of pure cellulose not aged and artificially aged as well as on ancient paper samples made in 1413 in Perpignan (France). The line shape parameters of the proton NMR spectra were studied as a function of the hydration content. Results indicate that water in aged samples is progressively involved in the hydration of the byproducts of cellulose degradation. This enhances the degradation process itself through the progressive consumption of the cellulose amorphous regions.

  8. One-azabicyclic compounds. 22. Stereochemistry and /sup 13/C NMR spectra of salts of pyrrolizidine and its homologs with protonic acids

    Energy Technology Data Exchange (ETDEWEB)

    Subbotin, O.A.; Skvortsov, I.M.

    1986-06-01

    /sup 13/C NMR spectra were obtained for pyrrolizidinium salts and their homologs and their signals were assigned. With the exception of highly strained cis-3,8-H-cis-5,8-H-3,5-dimethylpyrrolizidine (VI), all the bases studied upon their direct mixing with CF/sub 3/CO/sub 2/H form salts only with cis-fused rings in the cation. Mixtures of salts with cis- and trans-fused pyrrolizidinium fragments are formed upon the reaction of cis-3,8-H-methyl- (III) and cis-3,8-H-cis-5,8-H-3,5-dimethylpyrrolizidine (VI) under conditions close to those for kinetically-controlled amine protonation. The /sup 13/C NMR spectra of the isomeric pyrrolizidinium salts obtained as a result of the absorption of base VI by sulfuric acid were used to evaluate the conformational equilibrium in the starting compound VI. The /sup 13/C NMR chemical shifts of unsubstituted trans-fused pyrrolizidinium salts were predicted.

  9. Ring-Substituted Benzohydroxamic Acids: 1H, 13C and 15N NMR Spectra and NHOH Proton Exchange

    Czech Academy of Sciences Publication Activity Database

    Schraml, Jan; Tkadlecová, M.; Pataridis, S.; Soukupová, Ludmila; Blechta, Vratislav; Roithová, Jana; Exner, Otto

    2005-01-01

    Roč. 43, č. 7 (2005), s. 535-542 ISSN 0749-1581 R&D Projects: GA ČR(CZ) GA203/03/1566; GA AV ČR(CZ) IAA4072605; GA AV ČR(CZ) IAA4072005; GA MŠk(CZ) LB98233 Institutional research plan: CEZ:AV0Z40720504 Keywords : proton exchange * substituent effects * chemical shifts Subject RIV: CC - Organic Chemistry Impact factor: 1.553, year: 2005

  10. Structure of high-resolution NMR spectra

    CERN Document Server

    Corio, PL

    2012-01-01

    Structure of High-Resolution NMR Spectra provides the principles, theories, and mathematical and physical concepts of high-resolution nuclear magnetic resonance spectra.The book presents the elementary theory of magnetic resonance; the quantum mechanical theory of angular momentum; the general theory of steady state spectra; and multiple quantum transitions, double resonance and spin echo experiments.Physicists, chemists, and researchers will find the book a valuable reference text.

  11. Prediction of peak overlap in NMR spectra

    International Nuclear Information System (INIS)

    Hefke, Frederik; Schmucki, Roland; Güntert, Peter

    2013-01-01

    Peak overlap is one of the major factors complicating the analysis of biomolecular NMR spectra. We present a general method for predicting the extent of peak overlap in multidimensional NMR spectra and its validation using both, experimental data sets and Monte Carlo simulation. The method is based on knowledge of the magnetization transfer pathways of the NMR experiments and chemical shift statistics from the Biological Magnetic Resonance Data Bank. Assuming a normal distribution with characteristic mean value and standard deviation for the chemical shift of each observable atom, an analytic expression was derived for the expected overlap probability of the cross peaks. The analytical approach was verified to agree with the average peak overlap in a large number of individual peak lists simulated using the same chemical shift statistics. The method was applied to eight proteins, including an intrinsically disordered one, for which the prediction results could be compared with the actual overlap based on the experimentally measured chemical shifts. The extent of overlap predicted using only statistical chemical shift information was in good agreement with the overlap that was observed when the measured shifts were used in the virtual spectrum, except for the intrinsically disordered protein. Since the spectral complexity of a protein NMR spectrum is a crucial factor for protein structure determination, analytical overlap prediction can be used to identify potentially difficult proteins before conducting NMR experiments. Overlap predictions can be tailored to particular classes of proteins by preparing statistics from corresponding protein databases. The method is also suitable for optimizing recording parameters and labeling schemes for NMR experiments and improving the reliability of automated spectra analysis and protein structure determination.

  12. High-resolution proton and carbon-13 NMR of membranes: why sonicate?

    International Nuclear Information System (INIS)

    Oldfield, E.; Bowers, J.L.; Forbes, J.

    1987-01-01

    The authors have obtained high-field (11.7-T) proton and carbon-13 Fourier transform (FT) nuclear magnetic resonance (NMR) spectra of egg lecithin and egg lecithin-chloresterol (1:1) multibilayers, using magic-angle sample spinning (MASS) techniques, and sonicated egg lecithin and egg lecithin-cholesterol (1:1) vesicles, using conventional FT NMR methods. Resolution of the proton and carbon-13 MASS NMR spectra of the pure egg lecithin samples is essentially identical with that of sonicated samples, but spectra of the unsonicated lipid, using MASS, can be obtained very much faster than with the more dilute, sonicated systems. With the 1:1 lecithin-cholesterol system, proton MASS NMR spectra are virtually identical with conventional FT spectra of sonicated samples, while the 13 C NMR, the authors demonstrate that most 13 C nuclei in the cholesterol moiety can be monitored, even though these same nuclei are essentially invisible, i.e., are severely broadened, in the corresponding sonicated systems. In addition, 13 C MASS NMR spectra can again be recorded much faster than with sonicated samples, due to concentration effects. Taken together, these results strongly suggest there will seldom be need in the future to resort to ultransonic disruption of lipid bilayer membranes in order to obtain high-resolution proton or carbon-13 NMR spectra

  13. Teaching NMR spectra analysis with nmr.cheminfo.org.

    Science.gov (United States)

    Patiny, Luc; Bolaños, Alejandro; Castillo, Andrés M; Bernal, Andrés; Wist, Julien

    2018-06-01

    Teaching spectra analysis and structure elucidation requires students to get trained on real problems. This involves solving exercises of increasing complexity and when necessary using computational tools. Although desktop software packages exist for this purpose, nmr.cheminfo.org platform offers students an online alternative. It provides a set of exercises and tools to help solving them. Only a small number of exercises are currently available, but contributors are invited to submit new ones and suggest new types of problems. Copyright © 2018 John Wiley & Sons, Ltd.

  14. From proton nuclear magnetic resonance spectra to pH. Assessment of {sup 1}H NMR pH indicator compound set for deuterium oxide solutions

    Energy Technology Data Exchange (ETDEWEB)

    Tynkkynen, Tuulia, E-mail: tuulia.tynkkynen@uku.fi [Laboratory of Chemistry, Department of Biosciences, University of Kuopio, PO Box 1627, 70211 Kuopio (Finland); Tiainen, Mika; Soininen, Pasi; Laatikainen, Reino [Laboratory of Chemistry, Department of Biosciences, University of Kuopio, PO Box 1627, 70211 Kuopio (Finland)

    2009-08-19

    In this study, a protocol for pH determination from D{sub 2}O samples using {sup 1}H NMR pH indicator compounds was developed and assessed by exploring the pH-dependency of 13 compounds giving pH-dependent {sup 1}H NMR signals. The indicators cover the pH range from pH* 0 to 7.2. Equations to transform the indicator chemical shifts to pH estimates are given here for acetic acid, formic acid, chloroacetic acid, dichloroacetic acid, creatine, creatinine, glycine, histidine, 1,2,4-triazole, and TSP (2,2,3,3-tetradeutero-3-(trimethylsilyl)-propionic acid). To characterize the method in presence of typical solutes, the effects of common metabolites, albumin and ionic strength were also evaluated. For the ionic strengths, the effects were also modelled. The experiments showed that the use of pH sensitive {sup 1}H NMR chemical shifts allows the pH determination of typical metabolite solutions with accuracy of 0.01-0.05 pH units. Also, when the ionic strength is known with accuracy better than 0.1 mol dm{sup -3} and the solute concentrations are low, pH{sub nmr}{sup *} (the NMR estimate of pH) can be assumed to be within 0.05 pH units from potentiometrically determined pH.

  15. Proton NMR imaging in experimental ischemic infarction

    International Nuclear Information System (INIS)

    Buonanno, F.S.; Pykett, I.L.; Brady, T.J.; Vielma, J.; Burt, C.T.; Goldman, M.R.; Hinshaw, W.S.; Pohost, G.M.; Kistler, J.P.

    1983-01-01

    Proton nuclear magnetic resonance (NMR) images depict the distribution and concentration of mobile protons modified by the relaxation times T1 and T2. Using the steady-state-free-precession (SSFP) technique, serial coronal images were obtained sequentially over time in laboratory animals with experimental ischemic infarction. Image changes were evident as early as 2 hours after carotid artery ligation, and corresponded to areas of ischemic infarction noted pathologically. Resulting SSFP images in experimental stroke are contrasted to inversion-recovery NMR images in an illustrative patient with established cerebral infarction. Bulk T1 and T2 measurements were made in vitro in three groups of gerbils: normal, those with clinical evidence of infarction, and those clinically normal after carotid ligature. Infarcted hemispheres had significantly prolonged T1 and T2 (1.47 +/- .12 sec, 76.0 +/- 9.0 msec, respectively) when compared to the contralateral hemisphere (T1 . 1.28 +/- .05 sec, T2 . 58.7 +/- 3.9 msec) or to the other two groups. These data suggest that changes in NMR parameters occur and can be detected by NMR imaging as early as two hours after carotid artery ligation

  16. Proton and deuteron NMR study of PTFE ionomer membranes

    Energy Technology Data Exchange (ETDEWEB)

    Xu, G; Pak, Y S [Dept. of Materials Science, McMaster Univ., Hamilton, Ontario (Canada)

    1992-02-01

    Proton and deuteron NMR have been conducted to investigate the ionic motion in perfluorinated ionomer membranes from Dow Chemical (XUS) and DuPont (Nafion{sup R}). Two proton relaxation peaks were found in the XUS specimen absorbed with H{sub 2}O. The major (narrow) peak presented a spin-lattice relaxation time (T{sub 1}) of 107 ms while the minor (broader) one gave much longer T{sub 1}. While the former was attributed to the water molecules involved in restricted motion, the latter was expected to be associated with the protons located in the vicinity of the sulfonate groups. Similar to the previous results from the others, only a single peak was detected in Nafion{sup R} in {sup 1}H spectra, indicating that the protons in the different environments were engaging rapid exchange within NMR time scale. In contrast to the inverse proportion dependence of the linewidth on the water sorption in Nafion{sup R}, the major line of the XUS membrane exhibited insensitive linewidth dependence on the variation of H{sub 2}O concentration. The difference was attributed to the existence of narrow breaths of the pores in XUS sample, such that free water contribution to the enhancement of proton mobility was limited. The {sup 2}H spectra of Nafion{sup R} were found to possess a doublet, due to nuclear quadrupolar interaction. Dow (XUS) membrane treated in at 100% relative humidity (RH) D{sub 2}O presented a single peak with the linewidth insensitive to the amount of heavy water absorbed. An additional rise emerged on the ''shoulder'' of this single peak when treated at 33% RH. It is concluded that XUS membrane does not provide strong hydrogen bonding to eliminate the rapid motion average over the nuclear quadrupole interaction. (orig.).

  17. Crystallographically-based analysis of the NMR spectra of maghemite

    International Nuclear Information System (INIS)

    Spiers, K.M.; Cashion, J.D.

    2012-01-01

    All possible iron environments with respect to nearest neighbour vacancies in vacancy-ordered and vacancy-disordered maghemite have been evaluated and used as the foundation for a crystallographically-based analysis of the published NMR spectra of maghemite. The spectral components have been assigned to particular configurations and excellent agreement obtained in comparing predicted spectra with published spectra taken in applied magnetic fields. The broadness of the published NMR lines has been explained by calculations of the magnetic dipole fields at the various iron sites and consideration of the supertransferred hyperfine fields. - Highlights: ► Analysis of 57 Fe NMR of maghemite based on vacancy ordering and nearest neighbour vacancies. ► Assignment of NMR spectral components based on crystallographic analysis of unique iron sites. ► Strong agreement between predicted spectra and published spectra taken in applied magnetic fields. ► Maghemite NMR spectral broadening due to various iron sites and supertransferred hyperfine field.

  18. Proton and deuterium NMR experiments in zero field

    International Nuclear Information System (INIS)

    Millar, J.M.

    1986-02-01

    High field solid-state NMR lineshapes suffer from inhomogeneous broadening since resonance frequencies are a function of molecular orientation. Time domain zero field NMR is a two-dimensional field-cycling technique which removes this broadening by probing the evolution of the spin system under zero applied field. The simplest version, the sudden transition experiment, induces zero field evolution by the sudden removal of the applied magnetic field. Theory and experimental results of this experiment and several variations using pulsed dc magnetic fuelds to initiate zero field evolution are presented. In particular, the pulsed indirect detection method allows detection of the zero field spectrum of one nuclear spin species via another (usually protons) by utilizing the level crossings which occur upon adiabatic demagnetization to zero field. Experimental examples of proton/deuteron systems are presented which demonstrate the method results in enhanced sensitivity relative to that obtained in sudden transition experiments performed directly on deuterium. High resolution 2 H NQR spectra of a series of benzoic acid derivatives are obtained using the sudden transition and indirect detection methods. Librational oscillations in the water molecules of barium chlorate monohydrate are studied using proton and deuterium ZF experiments. 177 refs., 88 figs., 2 tabs

  19. Introduction to the conformational investigation of peptides and proteins by using two-dimensional proton NMR experiments

    International Nuclear Information System (INIS)

    Neumann, J.M.; Macquaire, F.

    1991-01-01

    This report presents the elementary bases for an initiation to the conformational study of peptides and proteins by using two-dimensional proton NMR experiments. First, some general features of protein structures are summarized. A second chapter is devoted to the basic NMR experiments and to the spectral parameters which provide a structural information. This description is illustrated by NMR spectra of peptides. The third chapter concerns the most standard two-dimensional proton NMR experiments and their use for a conformational study of peptides and proteins. Lastly, an example of NMR structural investigation of a peptide is reported [fr

  20. New methods for the correction of 31P NMR spectra in in vivo NMR spectroscopy

    International Nuclear Information System (INIS)

    Starcuk, Z.; Bartusek, K.; Starcuk, Z. jr.

    1994-01-01

    The new methods for the correction of 31 P NMR spectra in vivo NMR spectroscopy have been performed. A method for the baseline correction of the spectra which represents a combination of time-domain and frequency-domain has been discussed.The method is very fast and efficient for minimization of base line artifacts of biological tissues impact

  1. Simultaneous acquisition of three NMR spectra in a single ...

    Indian Academy of Sciences (India)

    Simultaneous acquisition of three NMR spectra in a single experiment ... set, which is based on a combination of different fast data acquisition techniques such as G-matrix ..... The sign and intensity of the CHn resonance depends on the delay.

  2. Bayesian Peak Picking for NMR Spectra

    KAUST Repository

    Cheng, Yichen

    2014-02-01

    Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.

  3. Proton NMR studies of functionalized nanoparticles in aqueous environments

    Science.gov (United States)

    Tataurova, Yulia Nikolaevna

    in high-resolution NMR spectra. This technique is selective for protons on the surface organic functional groups due to their motional averaging in solution. In this study, 1H solution NMR spectroscopy was used to investigate the interface of the organic functional groups in D2O. The pKa for these functional groups covalently bound to the surface of nanoparticles was determined using an NMR-pH titration method based on the variation in the proton chemical shift for the alkyl group protons closest to the amine group with pH. The adsorption of toxic contaminants (chromate and arsenate anions) on the surface of functionalized silicalite-1 and mesoporous silica nanoparticles has been studied by 1H solution NMR spectroscopy. With this method, the surface bound contaminants are detected. The analysis of the intensity and position of these peaks allows quantitative assessment of the relative amounts of functional groups with adsorbed metal ions. These results demonstrate the sensitivity of solution NMR spectroscopy to the electronic environment and structure of the surface functional groups on porous nanomaterials.

  4. Energetic Proton Spectra Measured by the Van Allen Probes

    Science.gov (United States)

    Summers, Danny; Shi, Run; Engebretson, Mark J.; Oksavik, Kjellmar; Manweiler, Jerry W.; Mitchell, Donald G.

    2017-10-01

    We test the hypothesis that pitch angle scattering by electromagnetic ion cyclotron (EMIC) waves can limit ring current proton fluxes. For two chosen magnetic storms, during 17-20 March 2013 and 17-20 March 2015, we measure proton energy spectra in the region 3 ≤ L ≤ 6 using the RBSPICE-B instrument on the Van Allen Probes. The most intense proton spectra are observed to occur during the recovery periods of the respective storms. Using proton precipitation data from the POES (NOAA and MetOp) spacecraft, we deduce that EMIC wave action was prevalent at the times and L-shell locations of the most intense proton spectra. We calculate limiting ring current proton energy spectra from recently developed theory. Comparisons between the observed proton energy spectra and the theoretical limiting spectra show reasonable agreement. We conclude that the measurements of the most intense proton spectra are consistent with self-limiting by EMIC wave scattering.

  5. Peakr: simulating solid-state NMR spectra of proteins

    International Nuclear Information System (INIS)

    Schneider, Robert; Odronitz, Florian; Hammesfahr, Bjorn; Hellkamp, Marcel; Kollmar, Martin

    2013-01-01

    When analyzing solid-state nuclear magnetic resonance (NMR) spectra of proteins, assignment of resonances to nuclei and derivation of restraints for 3D structure calculations are challenging and time-consuming processes. Simulated spectra that have been calculated based on, for example, chemical shift predictions and structural models can be of considerable help. Existing solutions are typically limited in the type of experiment they can consider and difficult to adapt to different settings. Here, we present Peakr, a software to simulate solid-state NMR spectra of proteins. It can generate simulated spectra based on numerous common types of internuclear correlations relevant for assignment and structure elucidation, can compare simulated and experimental spectra and produces lists and visualizations useful for analyzing measured spectra. Compared with other solutions, it is fast, versatile and user friendly. (authors)

  6. Enhanced NMR signal detection of imino protons in RNA molecules containing 3' dangling nucleotides

    International Nuclear Information System (INIS)

    Amborski, Andrew N.; Johnson, Philip E.

    2008-01-01

    We present a method for improving the quality of nuclear magnetic resonance (NMR) spectra involving exchangeable protons near the base of the stem of RNA hairpin molecules. NMR spectra of five different RNA hairpins were compared. These hairpins consisted of a native RNA structure and four molecules each having different unpaired, or dangling, nucleotides at the 3' end. NMR experiments were acquired in water for each construct and the quality of the imino proton spectral regions were examined. The imino resonances near the base of the stem of the wild type RNA structure were not observed due to breathing motions. However, a significant increase in spectral quality for molecules with dangling 3' adenosine or guanosine nucleotides was observed, with imino protons detected in these constructs that were not observed in the wild type construct. A modest improvement in spectral quality was seen for the construct with a 3' unpaired uridine, whereas no significant improvement was observed for a 3' unpaired cytidine. This improvement in NMR spectral quality mirrors the increased thermodynamic stability observed for 3' unpaired nucleotides which is dependant on the stacking interactions of these nucleotides against the base of the stem. The use of a dangling 3' adenosine nucleotide represents an easy method to significantly improve the quality of NMR spectra of RNA molecules

  7. Proton NMR relaxation in hydrous melts

    International Nuclear Information System (INIS)

    Braunstein, J.; Bacarella, A.L.; Benjamin, B.M.; Brown, L.L.; Girard, C.

    1976-01-01

    Pulse and continuous wave NMR measurements are reported for protons in hydrous melts of calcium nitrate at temperatures between -4 and 120 0 C. Although measured in different temperature ranges, spin-lattice (T 1 ) and spin-spin (T 2 ) relaxation times appear to be nearly equal to each other and proportional to the self-diffusion coefficients of solute metal cations such as Cd 2+ . At temperatures near 50 0 C, mean Arrhenius coefficients Δ H/sub T 1 / (kcal/mol) are 7.9, 7.3, and 4.8, respectively, for melts containing 2.8, 4.0, and 8.0 moles of water per mole of calcium nitrate, compared to 4.6 kcal/mol for pure water. Temperature dependence of T 1 and T 2 in Ca(NO 3 ) 2 -2.8 H 2 O between -4 and 120 0 C are non-Arrhenius and can be represented by a Fulcher-type equation with a ''zero mobility temperature'' (T 0 ) of 225 0 K, close to the value of T 0 for solute diffusion, electrical conductance and viscosity. Resolution of the relaxation rates into correlation times for intramolecular (rotational) and intermolecular (translational) diffusional motion is discussed in terms of the Bloembergen-Purcell-Pound and more recent models for dipolar relaxation

  8. Proton NMR study of α-MnH 0.06

    Science.gov (United States)

    Soloninin, A. V.; Skripov, A. V.; Buzlukov, A. L.; Antonov, V. E.; Antonova, T. E.

    2004-07-01

    Proton nuclear magnetic resonance (NMR) spectra and spin-lattice relaxation rates for the solid solution α-MnH 0.06 have been measured over the temperature range 11-297 K and the resonance frequency range 20-90 MHz. A considerable shift and broadening of the proton NMR line and a sharp peak of the spin-lattice relaxation rate are observed near 130 K. These effects are attributed to the onset of antiferromagnetic ordering below the Néel temperature TN≈130 K. The proton NMR line does not disappear in the antiferromagnetic phase; this suggests a small magnitude of the local magnetic fields at H-sites in α-MnH 0.06. The spin-lattice relaxation rate in the paramagnetic phase is dominated by the effects of spin fluctuations.

  9. 31P Solid-state MAS NMR spectra

    International Nuclear Information System (INIS)

    Grobet, P.J.; Geerts, H.; Martens, J.A.; Jacobs, P.A.

    1989-01-01

    The structures of the silicoaluminiophosphates MCM-1 and MCM9 were characterized by 27 Al and 31 P MAS NMR. The structural identity of MCM-1 and its silicon-free homologue AlPO 4 -H 3 is demonstrated. The presence of a structural mixture in MCM-9 is confirmed. 31 P MAS NMR spectra of MCM-9 could be interpreted as a superposition of spectra of VPI-5, AlPO 4 -H 3 and SAPO-11 phases. (author). 12 refs.; 3 figs.; 1 tab

  10. Prototropic tautomerism of 5-nitrobenzimidazole derivatives in {sup 1}H, {sup 13}C and {sup 15}N NMR spectra; Tautomeria prototropowa pochodnych 5-nitrobenzimidazolu w widmach {sup 1}H, {sup 13}C, {sup 15}N NMR

    Energy Technology Data Exchange (ETDEWEB)

    Wiench, J W; Bocian, W; Stefaniak, L [Inst. Chemii Organicznej, Polska Akademia Nauk, Warsaw (Poland)

    1994-12-31

    NMR spectra of 5-nitrobenzimidazole derivatives in DMSO solution show the fast exchange of protons. The line broadening in {sup 1}H,{sup 13}C and {sup 15}N spectra have been observed. The interpretation of the spectra has been done basing on chemical shifts values and couplings between nuclei in the investigated derivatives. 3 refs, 2 figs, 3 tabs.

  11. 13C-NMR spectra and bonding situation in ketenimines

    International Nuclear Information System (INIS)

    Firl, J.; Runge, W.; Hartmann, W.; Utikal, H.P.

    1975-01-01

    13 C-NMR spectra of a series of substituted ketenimines are reported. The terminal carbon resonances are found at unusual high fields between delta 37 and 78, while the central carbon signals appear around delta 189 - 196. On the basis of these results, the bonding situation in ketenimines has been discussed. (auth.)

  12. Amide proton exchange rates of a bound pepsin inhibitor determined by isotope-edited proton NMR experiments

    International Nuclear Information System (INIS)

    Fesik, S.W.; Luly, J.R.; Stein, H.H.; BaMaung, N.

    1987-01-01

    From a series of isotope-edited proton NMR spectra, amide proton exchange rates were measured at 20 C, 30 C, and 40 0 C for a tightly bound 15 N-labeled tripeptide inhibitor of porcine pepsin (IC50 = 1.7 X 10(-) M). Markedly different NH exchange rates were observed for the three amide protons of the bound inhibitor. The P1 NH exchanged much more slowly than the P2 NH and P3 NH. These results are discussed in terms of the relative solvent accessibility in the active site and the role of the NH protons of the inhibitor for hydrogen bonding to the enzyme. In this study a useful approach is demonstrated for obtaining NH exchange rates on ligands bound to biomacromolecules, the knowledge of which could be of potential utility in the design of therapeutically useful nonpeptide enzyme inhibitors from peptide leads

  13. Quantification of aluminium-27 NMR spectra of high-surface-area oxides

    International Nuclear Information System (INIS)

    Pearson, R.M.; Schramm, C.M.

    1990-01-01

    This paper discusses the quantitation of 27 Al NMR spectra. It is showns that the so called 'invisible' aluminium atoms seen by recent workers are completely consistent with known continuous wave NMR studies of the 27 Al NMR spectra of high surface area aluminium oxides. The use of pulsed NMR techniques further complicate the quantitative measurement of 27 Al NMR spectra, especially when high resolution NMR spectrometers are used for this purpose. Methods are described which allow both the estimation of aluminium not seen by continuous wave techniques and the amounts of the NMR spectra lost in pulsed work. (author). 24 refs.; 6 figs.; 1 tab

  14. Peptides containing internal residues of pyroglutamic acid: proton NMR characteristics

    International Nuclear Information System (INIS)

    Khan, S.A.

    1986-01-01

    The proton NMR characteristics of internal pyroglutamic acid (Glp; 5-oxoproline) residues in seven tripeptides of the general structure Boc-Xxx-Glp-Yyy-NH 2 were studied. In general, the chemical shifts of several diagnostic protons moved downfield on going from the Glu-containing peptides (Boc-Xxx-Glu-Yyy-NH 2 ) to the corresponding Glp-containing peptides. The C-2 proton of the Xxx residue was shifted by about 1.1 ppm. The N-2 proton of the Yyy residue was shifted by about 0.5 ppm. The C-2 proton of the Glx residue itself was shifted by about 0.5 ppm. One of the Glx C-3 protons was also shifted by about 0.5 ppm, but the other remained essentially unchanged. Finally, the Glx C-4 protons were shifted by about 0.3 ppm. Internal Glu residues are readily converted chemically into internal Glp residues. This conversion also occurs as a side reaction during HP cleavage of the protecting group from Glu(OBzl) residues. The spontaneous fragmentation of serum proteins C3, C4 and λ 2 -macroglobulin under denaturing conditions is probably due to regioselective hydrolysis of an internal Glp residue formed in each of these proteins upon denaturation. These proton NMR characteristics may be useful in establishing the presence of internal Glp residues in synthetic and natural peptides

  15. ImatraNMR: Novel software for batch integration and analysis of quantitative NMR spectra

    Science.gov (United States)

    Mäkelä, A. V.; Heikkilä, O.; Kilpeläinen, I.; Heikkinen, S.

    2011-08-01

    Quantitative NMR spectroscopy is a useful and important tool for analysis of various mixtures. Recently, in addition of traditional quantitative 1D 1H and 13C NMR methods, a variety of pulse sequences aimed for quantitative or semiquantitative analysis have been developed. To obtain actual usable results from quantitative spectra, they must be processed and analyzed with suitable software. Currently, there are many processing packages available from spectrometer manufacturers and third party developers, and most of them are capable of analyzing and integration of quantitative spectra. However, they are mainly aimed for processing single or few spectra, and are slow and difficult to use when large numbers of spectra and signals are being analyzed, even when using pre-saved integration areas or custom scripting features. In this article, we present a novel software, ImatraNMR, designed for batch analysis of quantitative spectra. In addition to capability of analyzing large number of spectra, it provides results in text and CSV formats, allowing further data-analysis using spreadsheet programs or general analysis programs, such as Matlab. The software is written with Java, and thus it should run in any platform capable of providing Java Runtime Environment version 1.6 or newer, however, currently it has only been tested with Windows and Linux (Ubuntu 10.04). The software is free for non-commercial use, and is provided with source code upon request.

  16. An NMR Protonation Study of Metal Diethylenetriaminepentaacetic Acid Complexes.

    Science.gov (United States)

    Letkeman, Peter

    1979-01-01

    This experiment is suitable for an integrated laboratory course for senior chemistry majors. It introduces the student to a study of the relative basicity of different proton accepting sites. It serves as an opportunity to learn about nmr techniques and could extend to infrared, as well. (BB)

  17. Cation Hydration Constants by Proton NMR: A Physical Chemistry Experiment.

    Science.gov (United States)

    Smith, Robert L.; And Others

    1988-01-01

    Studies the polarization effect on water by cations and anions. Describes an experiment to illustrate the polarization effect of sodium, lithium, calcium, and strontium ions on the water molecule in the hydration spheres of the ions. Analysis is performed by proton NMR. (MVL)

  18. Assignment strategies in homonuclear three-dimensional 1H NMR spectra of proteins

    International Nuclear Information System (INIS)

    Vuister, G.W.; Boelens, R.; Padilla, A.; Kleywegt, G.J.; Kaptein, R.

    1990-01-01

    The increase in dimensionality of three-dimensional (3D) NMR greatly enhances the spectral resolution in comparison to 2D NMR. It alleviates the problem of resonance overlap and may extend the range of molecules amenable to structure determination by high-resolution NMR spectroscopy. Here, the authors present strategies for the assignment of protein resonances from homonuclear nonselective 3D NOE-HOHAHA spectra. A notation for connectivities between protons, corresponding to cross peaks in 3D spectra, is introduced. They show how spin systems can be identified by tracing cross-peak patterns in cross sections perpendicular to the three frequency axes. The observable 3D sequential connectivities in proteins are tabulated, and estimates for the relative intensities of the corresponding cross peaks are given for α-helical and β-sheet conformations. Intensities of the cross peaks in the 3D spectrum of pike III paravalbumin follow the predictions. The sequential-assignment procedure is illustrated for loop regions, extended and α-helical conformations for the residues Ala 54-Leu 63 of paravalbumin. NOEs that were not previously identified in 2D spectra of paravalbumin due to overlap are found

  19. Classical and quantum molecular dynamics in NMR spectra

    CERN Document Server

    Szymański, Sławomir

    2018-01-01

    The book provides a detailed account of how condensed-phase molecular dynamics are reflected in the line shapes of NMR spectra. The theories establishing connections between random, time-dependent molecular processes and lineshape effects are exposed in depth. Special emphasis is placed on the theoretical aspects, involving in particular intermolecular processes in solution, and molecular symmetry issues. The Liouville super-operator formalism is briefly introduced and used wherever it is beneficial for the transparency of presentation. The proposed formal descriptions of the discussed problems are sufficiently detailed to be implemented on a computer. Practical applications of the theory in solid- and liquid-phase studies are illustrated with appropriate experimental examples, exposing the potential of the lineshape method in elucidating molecular dynamics NMR-observable molecular phenomena where quantization of the spatial nuclear degrees of freedom is crucial are addressed in the last part of the book. As ...

  20. Solid-state NMR covariance of homonuclear correlation spectra.

    Science.gov (United States)

    Hu, Bingwen; Amoureux, Jean-Paul; Trebosc, Julien; Deschamps, Michael; Tricot, Gregory

    2008-04-07

    Direct covariance NMR spectroscopy, which does not involve a Fourier transformation along the indirect dimension, is demonstrated to obtain homonuclear correlation two-dimensional (2D) spectra in the solid state. In contrast to the usual 2D Fourier transform (2D-FT) NMR, in a 2D covariance (2D-Cov) spectrum the spectral resolution in the indirect dimension is determined by the resolution along the detection dimension, thereby largely reducing the time-consuming indirect sampling requirement. The covariance method does not need any separate phase correction or apodization along the indirect dimension because it uses those applied in the detection dimension. We compare in detail the specifications obtained with 2D-FT and 2D-Cov, for narrow and broad resonances. The efficiency of the covariance data treatment is demonstrated in organic and inorganic samples that are both well crystallized and amorphous, for spin -1/2 nuclei with 13C, 29Si, and 31P through-space or through-bond homonuclear 2D correlation spectra. In all cases, the experimental time has been reduced by at least a factor of 10, without any loss of resolution and signal to noise ratio, with respect to what is necessary with the 2D-FT NMR. According to this method, we have been able to study the silicate network of glasses by 2D NMR within reasonable experimental time despite the very long relaxation time of the 29Si nucleus. The main limitation of the 2D-Cov data treatment is related to the introduction of autocorrelated peaks onto the diagonal, which does not represent any actual connectivity.

  1. Techniques and approaches to proton NMR imaging of the head

    International Nuclear Information System (INIS)

    Pykett, I.L.; Buonanno, F.S.; Brady, T.J.; Kistler, J.P.

    1983-01-01

    The next few years will undoubtedly see a refinement of proton imaging technology and a broader data base will indicate to what extent proton relaxation parameters are able to detect and characterize disease. In addition, it is likely that imaging of other nuclei (e.g. 31 P, 23 Na, 19 F) will become a reality, although it must be stated that due to their inherently lower sensitivity to NMR detection and/or lower physiological concentration, clinical images of nuclei other than 1 H will undoubtedly have a low spatial resolution and may require relatively long imaging times. Nonetheless, herein lies the exciting possibility of non-invasive metabolic or functional imaging. The realm of NMR contrast agents is just beginning to be explored, and developments in high-speed imaging indicate useful applications in cardiology. So whilst improvements in image quality can be expected, as was the case with X-ray CT, the application of NMR in medicine will diversify to yield information of a more specifically functional nature. This, together with the very low attendant biological risk, heralds a bright future for NMR in clinical diagnosis

  2. High-resolution proton NMR spectroscopy of cerebrospinal fluid: methodological issues and potential clinical applications

    International Nuclear Information System (INIS)

    Kriat, M.; Nicoli, F.; Vion-Dury, J.; Confort-Gouny, S.; Cozzone, P.J.; Nicoli, F.; Gastaut, J.L.; Dano, P.; Grisoli, F.

    1991-01-01

    High resolution proton nuclear magnetic resonance (NMR) spectroscopy is a new analytical technique which allows to readily identify and quantitate a variety of key metabolites in cerebrospinal fluid (CSF) in relation to normal and pathological brain activity. Proton NMR spectroscopy can be performed on native CSF, with or without addition of exchange reagent (NH 4 Cl). The analysis of native CSF provides qualitative information (identification) of metabolites or xenobiotics present in the fluid. Alternately, CSF can be lyophilized and dissolved in deuterated water. This concentration offers 2 advantages: additional compounds are detected and a precise quantification of all CSF metabolites can be obtained. Both protocols require a very small volume of CFS (1-2 ml). The high informational content available on the NMR spectra of CSF, the ease-of-use of NMR spectroscopy and its cost effectiveness concur to predict that this analytical approach will keep developing to completement the array of existing tests which are already routinely performed on CSF. 6 figs [fr

  3. Main-chain-directed strategy for the assignment of 1H NMR spectra of proteins

    International Nuclear Information System (INIS)

    Englander, S.W.; Wand, A.J.

    1987-01-01

    A strategy for assigning the resonances in two-dimensional (2D) NMR spectra of proteins is described. The method emphasizes the analysis of through-space relationships between protons by use of the two-dimensional nuclear Overhauser effect (NOE) experiment. NOE patterns used in the algorithm were derived from a statistical analysis of the combinations of short proton-proton distances observed in the high-resolution crystal structures of 21 proteins. One starts with a search for authentic main-chain NH-C/sub α/H-C/sub β/H J-coupled units, which can be found with high reliability. The many main-chain units of a protein are then placed in their proper juxtaposition by recognition of predefined NOE connectivity patterns. To discover these connectivities, the 2D NOE spectrum is examined, in a prescribed order, for the distinct NOE patterns characteristic of helices, sheets, turns, and extended chain. Finally, the recognition of a few amino acid side-chain types places the discovered secondary structure elements within the polypeptide sequences. Unlike the sequential assignment approach, the main-chain-directed strategy does not rely on the difficult task of recognizing many side-chain spin systems in J-correlated spectra, the assignment process is not in general sequential with the polypeptide chain, and the prescribed connectivity patterns are cyclic rather than linear. The latter characteristic avoids ambiguous branch points in the analysis and imposed an internally confirmatory property on each forward step

  4. Line-narrowing in proton-detected nitrogen-14 NMR

    Science.gov (United States)

    Cavadini, Simone; Vitzthum, Veronika; Ulzega, Simone; Abraham, Anuji; Bodenhausen, Geoffrey

    2010-01-01

    In solids spinning at the magic angle, the indirect detection of single-quantum (SQ) and double-quantum (DQ) 14N spectra ( I = 1) via spy nuclei S = 1/2 such as protons can be achieved in the manner of heteronuclear single- or multiple-quantum correlation (HSQC or HMQC) spectroscopy. The HMQC method relies on the excitation of two-spin coherences of the type T11IT11S and T21IT11S at the beginning of the evolution interval t1. The spectra obtained by Fourier transformation from t1 to ω1 may be broadened by the homogenous decay of the transverse terms of the spy nuclei S. This broadening is mostly due to homonuclear dipolar S- S' interactions between the proton spy nuclei. In this work we have investigated the possibility of inserting rotor-synchronized symmetry-based C or R sequences and decoupling schemes such as Phase-Modulated Lee-Goldburg (PMLG) sequences in the evolution period. These schemes reduce the homonuclear proton-proton interactions and lead to an enhancement of the resolution of both SQ and DQ proton-detected 14N HMQC spectra. In addition, we have investigated the combination of HSQC with symmetry-based sequences and PMLG and shown that the highest resolution in the 14N dimension is achieved by using HSQC in combination with symmetry-based sequences of the R-type. We show improvements in resolution in samples of L-alanine and the tripeptide ala-ala-gly (AAG). In particular, for L-alanine the width of the 14N SQ peak is reduced from 2 to 1.2 kHz, in agreement with simulations. We report accurate measurements of quadrupolar coupling constants and asymmetry parameters for amide 14N in AAG peptide bonds.

  5. Dynamic domains of amyloid fibrils can be site-specifically assigned with proton detected 3D NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Falk, Alexander S.; Siemer, Ansgar B., E-mail: asiemer@usc.edu [Keck School of Medicine of USC, Department of Biochemistry and Molecular Medicine, Zilkha Neurogenetic Institute (United States)

    2016-11-15

    Several amyloid fibrils have cores framed by highly dynamic, intrinsically disordered, domains that can play important roles for function and toxicity. To study these domains in detail using solid-state NMR spectroscopy, site-specific resonance assignments are required. Although the rapid dynamics of these domains lead to considerable averaging of orientation-dependent NMR interactions and thereby line-narrowing, the proton linewidths observed in these samples is far larger than what is regularly observed in solution. Here, we show that it is nevertheless possible to record 3D HNCO, HNCA, and HNcoCA spectra on these intrinsically disordered domains and to obtain site-specific assignments.

  6. Dynamic domains of amyloid fibrils can be site-specifically assigned with proton detected 3D NMR spectroscopy

    International Nuclear Information System (INIS)

    Falk, Alexander S.; Siemer, Ansgar B.

    2016-01-01

    Several amyloid fibrils have cores framed by highly dynamic, intrinsically disordered, domains that can play important roles for function and toxicity. To study these domains in detail using solid-state NMR spectroscopy, site-specific resonance assignments are required. Although the rapid dynamics of these domains lead to considerable averaging of orientation-dependent NMR interactions and thereby line-narrowing, the proton linewidths observed in these samples is far larger than what is regularly observed in solution. Here, we show that it is nevertheless possible to record 3D HNCO, HNCA, and HNcoCA spectra on these intrinsically disordered domains and to obtain site-specific assignments.

  7. Two-proton energy spectra of 12O nucleus

    International Nuclear Information System (INIS)

    Teruya, N.

    2010-01-01

    Full text: The two-proton radioactivity has attracted stimulating discussion concerning the competing mechanisms for the decay process. Some nuclei (like 45 Fe, 41 Ni and 54 Zn are considered as genuine ground-state two-proton emitter because the only possibility is the simultaneous channel, but others nuclei (as 12 O) can also have the sequential decay, in this case, the energy levels of the intermediary one-proton emitter nuclei plays an important role to the competition with the simultaneous decay mode. In this work we have calculated the energy spectra of 12 O, including ground state and excited states up to 5 MeV of energy, and the two-proton energy difference spectrum for the ground state decay. Our preliminary results estimates the energy peak and width of resonant excited states and contributions of simultaneous and sequential channels for ground state decay. The calculation method is based on the statistical analysis for two-proton decaying modes presented in previous work. For events generated by sequential channels, the energy levels of intermediary 11 N nucleus can dominate the first proton emission, depending on the proximity between the ground states of both nuclei, 11 N and 12 O , in particular, if the ground state of 11 N is broad and its energy is far away from that of 12 O, the sequential decay occurs via the tail of the ground state of 11 O. The decay of 12 O resonant ground state and higher energy excited resonances are investigated through the analysis of the experimental data for the two-proton emission process. The two proton decay spectra have been considered in a statistical calculation framework, by using the decay energy distribution and taken into account the intermediate states of 11 N resonant structures for the sequential channels. For simultaneous decay channel we construct a symmetric distribution similarly to Goldansky's proposition in Nucl. Phys. A19, 482 (1960). (author)

  8. Correlation of the antimicrobial activity of salicylaldehydes with broadening of the NMR signal of the hydroxyl proton. Possible involvement of proton exchange processes in the antimicrobial activity.

    Science.gov (United States)

    Elo, Hannu; Kuure, Matti; Pelttari, Eila

    2015-03-06

    Certain substituted salicylaldehydes are potent antibacterial and antifungal agents and some of them merit consideration as potential chemotherapeutic agents against Candida infections, but their mechanism of action has remained obscure. We report here a distinct correlation between broadening of the NMR signal of the hydroxyl proton of salicylaldehydes and their activity against several types of bacteria and fungi. When proton NMR spectra of the compounds were determined using hexadeuterodimethylsulfoxide as solvent and the height of the OH proton signal was measured, using the signal of the aldehyde proton as an internal standard, it was discovered that a prerequisite of potent antimicrobial activity is that the proton signal is either unobservable or relatively very low, i.e. that it is extremely broadened. Thus, none of the congeners whose OH proton signal was high were potent antimicrobial agents. Some congeners that gave a very low OH signal were, however, essentially inactive against the microbes, indicating that although drastic broadening of the OH signal appears to be a prerequisite, also other (so far unknown) factors are needed for high antimicrobial activity. Because broadening of the hydroxyl proton signal is related to the speed of the proton exchange process(es) involving that proton, proton exchange may be involved in the mechanism of action of the compounds. Further studies are needed to analyze the relative importance of different factors (such as electronic effects, strength of the internal hydrogen bond, co-planarity of the ring and the formyl group) that determine the rates of those processes. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  9. Sequence-specific 1H NMR resonance assignments of Bacillus subtilis HPr: Use of spectra obtained from mutants to resolve spectral overlap

    International Nuclear Information System (INIS)

    Wittekind, M.; Klevit, R.E.; Reizer, J.

    1990-01-01

    On the basis of an analysis of two-dimensional 1 H NMR spectra, the complete sequence-specific 1 H NMR assignments are presented for the phosphocarrier protein HPr from the Gram-positive bacterium Bacillus subtilis. During the assignment procedure, extensive use was made of spectra obtained from point mutants of HPr in order to resolve spectral overlap and to provide verification of assignments. Regions of regular secondary structure were identified by characteristic patterns of sequential backbone proton NOEs and slowly exchanging amide protons. B subtilis HPr contains four β-strands that form a single antiparallel β-sheet and two well-defined α-helices. There are two stretches of extended backbone structure, one of which contains the active site His 15 . The overall fold of the protein is very similar to that of Escherichia coli HPr determined by NMR studies

  10. Sensitivity of NMR spectra properties to different inversion algorithms. Abstract 97

    International Nuclear Information System (INIS)

    Bryan, J.; Wang, G.; Vargas, S.; Kantzas, A.

    2004-01-01

    'Full text:' Low field NMR technology has many applications in the petroleum industry. NMR spectra obtained from logging tools or laboratory instruments can be used to provide an incredible wealth of useful information for formation evaluation and reservoir fluid characterization purposes. In recent years, research performed at the University of Calgary has been instrumental in developing this technology for heavy oil and bitumen related problems. Specifically, low field NMR has been used in several niche applications: in-situ viscosity estimates of heavy oil and bitumen, water-in-oil emulsion and solvent-bitumen mixture viscosity, water cut in produced fluid streams, and oil-water-solids content in oil sands mining samples. The majority of all NMR analyses are based on the interpretation of NMR spectra. These spectra are inverted numerically from the measured NMR decay data. The mathematics of the inversion is generally assumed to be correct, and the analyses revolve around interpretations of how the spectra relate to physical properties of the samples. However, when measuring high viscosity fluids or clay-bound water, the NMR signal relaxes very quickly and it becomes extremely important to ensure that the spectrum obtained is accurate before relating its properties to physics. This work investigates the effect of different inversion algorithms on the generated spectra, and attempts to quantify the magnitude of the errors that can be associated with the mathematics of inversion. This leads to a better understanding of the accuracy of NMR estimates of rock and fluid properties. (author)

  11. Nucleic acid helix structure determination from NMR proton chemical shifts

    Energy Technology Data Exchange (ETDEWEB)

    Werf, Ramon M. van der; Tessari, Marco; Wijmenga, Sybren S., E-mail: S.Wijmenga@science.ru.nl [Radboud University Nijmegen, Department of Biophysical Chemistry, Institute of Molecules and Materials (Netherlands)

    2013-06-15

    We present a method for de novo derivation of the three-dimensional helix structure of nucleic acids using non-exchangeable proton chemical shifts as sole source of experimental restraints. The method is called chemical shift de novo structure derivation protocol employing singular value decomposition (CHEOPS) and uses iterative singular value decomposition to optimize the structure in helix parameter space. The correct performance of CHEOPS and its range of application are established via an extensive set of structure derivations using either simulated or experimental chemical shifts as input. The simulated input data are used to assess in a defined manner the effect of errors or limitations in the input data on the derived structures. We find that the RNA helix parameters can be determined with high accuracy. We finally demonstrate via three deposited RNA structures that experimental proton chemical shifts suffice to derive RNA helix structures with high precision and accuracy. CHEOPS provides, subject to further development, new directions for high-resolution NMR structure determination of nucleic acids.

  12. Improved Baseline in 29Si NMR Spectra of Water Glasses

    Czech Academy of Sciences Publication Activity Database

    Schraml, Jan; Sandor, P.; Korec, S.; Krump, M.; Foller, B.

    2013-01-01

    Roč. 51, č. 7 (2013), s. 403-406 ISSN 0749-1581 Grant - others:GA MPO(CZ) FR-TI1/335; GA MŠk(CZ) LM2011020 Institutional support: RVO:67985858 Keywords : NMR * 29Si NMR * acoustic ringing Subject RIV: JI - Composite Materials Impact factor: 1.559, year: 2013

  13. Synthesis and proton-NMR studies of oligonucleotides containing an apurinic (AP) site

    International Nuclear Information System (INIS)

    Raap, J.; Dreef, C.E.; van der Marel, G.A.; van Boom, J.H.; Hilbers, C.W.

    1987-01-01

    In order to elucidate the conformational properties of base-deleted oligodeoxyribonucleotides, the molecules d-CpS(pCpG)n (n = 1,2; S = sugar) were synthesized by the phosphotriester method and characterized by 1H-NMR spectroscopy. Complete assignment of all non-exchangeable proton resonances of both compounds was obtained by 1D- and 2D-NMR techniques. In combination with computer simulation, these spectra yielded proton-proton and proton-phosphorus coupling constants of high accuracy. These data provide valuable information about the sugar and the backbone conformation. It appears that d-Cp1Sp2Cp3G4 does not form a duplex under any of the conditions studied. On the contrary, the base-deleted hexamer d-Cp1Sp2Cp3Gp4Cp5G6 occurs as a right-handed' staggered' DNA duplex at 280 K: the core of this duplex is formed by the residues C(3)-G(6); two 'dangling' residues C(1) and S(2) are located at the two 5'-ends of the duplex. The assignment of the corresponding imino proton resonances for [d-CpS(pCpG)2]2 was based on their thermal behavior: the line broadening of these resonances was studied as a function of temperature. The chemical shift and the number of imino proton resonances accord well with the number and type of Watson-Crick base pairs which can be formed in the staggered duplex described above. Thermodynamic parameters of duplex formation were obtained from an analysis of the chemical shift versus temperature profiles of aromatic base and H-1' protons. It is suggested that the cytosine ring of C(1) stacks, at least part of the time, with the guanine ring on the nucleotide residue, G(6), situated in the complementary strand. The binding of Lys-Trp-Lys to [d-CpS(pCpG)2]2 as well as to [d-CpGpCpG]1 was investigated

  14. Proton chemical shift tensors determined by 3D ultrafast MAS double-quantum NMR spectroscopy

    International Nuclear Information System (INIS)

    Zhang, Rongchun; Mroue, Kamal H.; Ramamoorthy, Ayyalusamy

    2015-01-01

    Proton NMR spectroscopy in the solid state has recently attracted much attention owing to the significant enhancement in spectral resolution afforded by the remarkable advances in ultrafast magic angle spinning (MAS) capabilities. In particular, proton chemical shift anisotropy (CSA) has become an important tool for obtaining specific insights into inter/intra-molecular hydrogen bonding. However, even at the highest currently feasible spinning frequencies (110–120 kHz), 1 H MAS NMR spectra of rigid solids still suffer from poor resolution and severe peak overlap caused by the strong 1 H– 1 H homonuclear dipolar couplings and narrow 1 H chemical shift (CS) ranges, which render it difficult to determine the CSA of specific proton sites in the standard CSA/single-quantum (SQ) chemical shift correlation experiment. Herein, we propose a three-dimensional (3D) 1 H double-quantum (DQ) chemical shift/CSA/SQ chemical shift correlation experiment to extract the CS tensors of proton sites whose signals are not well resolved along the single-quantum chemical shift dimension. As extracted from the 3D spectrum, the F1/F3 (DQ/SQ) projection provides valuable information about 1 H– 1 H proximities, which might also reveal the hydrogen-bonding connectivities. In addition, the F2/F3 (CSA/SQ) correlation spectrum, which is similar to the regular 2D CSA/SQ correlation experiment, yields chemical shift anisotropic line shapes at different isotropic chemical shifts. More importantly, since the F2/F1 (CSA/DQ) spectrum correlates the CSA with the DQ signal induced by two neighboring proton sites, the CSA spectrum sliced at a specific DQ chemical shift position contains the CSA information of two neighboring spins indicated by the DQ chemical shift. If these two spins have different CS tensors, both tensors can be extracted by numerical fitting. We believe that this robust and elegant single-channel proton-based 3D experiment provides useful atomistic-level structural and dynamical

  15. On the {sup 1}H NMR spectra of 2-substituted benzoquinones

    Energy Technology Data Exchange (ETDEWEB)

    Tedeschi, E.; Rezende, D. B. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica; Arruda Campos, I.P. de, E-mail: ipdacamp@uol.com.br [Universidade Paulista, Sao Paulo, SP (Brazil). Inst. de Ciencias Exatas e Tecnologia. Programa de Pos-Graduacao em Engenharia de Producao

    2009-07-01

    The novel complete analysis of the {sup 1}H NMR spectra of six monosubstituted benzoquinones is reported herein, together with a brief but complete review of the scanty previously published data on benzoquinone and its monosubstituded derivatives. (author)

  16. Inclusive spectra of hadrons in proton-nucleus collisions

    International Nuclear Information System (INIS)

    Gevorkyan, S.R.; Gulkanyan, G.R.; Kotzinyan, A.M.; Zhamkochyan, V.M.

    1985-01-01

    A model is proposed, which allows one to describe all exprimental data on inclusive spectra of different hadrons produced on nuclei. The model is based on the following assumptions. After the first inelastic collision with nucleon in the nucleus the proton transforms into some excited system H, which collides with the other nucleons during its passage through the nucleus. Since in inelastic collisions the slow sea partons play the dominant role, the valence quarks of this system H coincide with those of proton. Fragmentation of H into hadrons (as well as into proton) is dilated in the lab system by the Lorentz factor E/m >> 1 and so it takes place out of the nucleus. Using the methods of multiple scattering theory one can receive the connection between inclusive spectra on nuclei and those on nucleons. The calculations of inclusive spectra of different hadrons (p, p, πsup(-+), ksup(+-)) were done, and a satisfactory description of the experimental data was obtained. It should be noted that this description was done without introduction of any free parameters. Analogous models are discussed, and their diffference from the method proposed is outlined

  17. Proton and Helium Spectra from the CREAM-III Flight

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Y. S.; Han, J. H.; Kim, K. C.; Kim, M. H.; Lee, M. H.; Lee, S. E. [Institute for Physical Science and Technology, University of Maryland, College Park, MD, 20742 (United States); Anderson, T.; Conklin, N. B.; Coutu, S.; Mognet, S. I. [Department of Physics, Penn State University, University Park, PA 16802 (United States); Barrau, A.; Derome, L. [Laboratoire de Physique Subatomique et Cosmologie, Grenoble (France); Jeon, J. A.; Lee, H. Y.; Lee, J.; Park, I. H. [Department of Physics, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Link, J. T.; Mitchell, J. W. [Astrophysics Space Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Menchaca-Rocha, A. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico (Mexico); Nutter, S. [Department of Physics, Northern Kentucky University, Highland Heights, KY 41099 (United States); and others

    2017-04-10

    Primary cosmic-ray elemental spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment since 2004. The third CREAM payload (CREAM-III) flew for 29 days during the 2007–2008 Antarctic season. Energies of incident particles above 1 TeV are measured with a calorimeter. Individual elements are clearly separated with a charge resolution of ∼0.12 e (in charge units) and ∼0.14 e for protons and helium nuclei, respectively, using two layers of silicon charge detectors. The measured proton and helium energy spectra at the top of the atmosphere are harder than other existing measurements at a few tens of GeV. The relative abundance of protons to helium nuclei is 9.53 ± 0.03 for the range of 1 TeV/n to 63 TeV/n. This ratio is considerably smaller than other measurements at a few tens of GeV/n. The spectra become softer above ∼20 TeV. However, our statistical uncertainties are large at these energies and more data are needed.

  18. EBS/C proton spectra from a virgin diamond crystal

    Energy Technology Data Exchange (ETDEWEB)

    Erich, M., E-mail: marko.erich@gmail.com [Laboratory of Physics, Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 552, Belgrade (Serbia); Kokkoris, M. [Department of Physics, National Technical University of Athens, Zografou Campus 157 80, Athens (Greece); Fazinić, S. [Laboratory for Ion Beam Interactions, Department of Experimental Physics, Institute Ruđer Bošković, Bijenička cesta 54, 10000 Zagreb (Croatia); Petrović, S. [Laboratory of Physics, Vinča Institute of Nuclear Sciences, University of Belgrade, PO Box 552, Belgrade (Serbia)

    2016-08-15

    In the present work, elastic backscattering channeling spectra, EBS/C, of protons in a 〈1 0 0〉 diamond crystal were experimentally and theoretically studied via a new computer simulation code. Proton incident energies for EBS/C spectra were in the energy range from 1.0 MeV to 1.9 MeV. The energy range was chosen in order to explore a distinct strong resonance of the {sup 12}C(p,p{sub 0}){sup 12}C elastic scattering at 1737 keV. The computer simulation code applied for the fitting of the experimental spectra in the random mode was compared with the corresponding SIMNRA results. In the channeling mode, it assumes a Gompertz type sigmoidal dechanneling function, which has two fitting parameters, x{sub c} and k, the dechanneling range and rate, respectively. It also uses α, ratio of the channeling to random energy losses, as a fitting parameter. It was observed that x{sub c} increases, k decreases and α stays relatively constant with the proton incident energy. These observations confirm the physical interpretation of the fitting parameters. Also, they constitute the basics for the further development of the code for the quantification of induced amorphization and depth profiling of implanted ions.

  19. NMR determination of the order parameter in proton and deuteron glasses

    International Nuclear Information System (INIS)

    Blinc, R.; Dolinsek, J.; Zalar, B.

    1989-01-01

    The inhomogeneous broadening of the ND + deuteron, O-D--O deuteron and 87 Rb quadrapole perturbed NMR spectra in Rb 0.56 (ND 4 ) 0.44 D 2 PO 4 is used for a direct determination of the Edwards-Anderson pseudo-spin glass order parameter. The data provide strong support for a model where the basic difference between magnetic spin glasses and proton or deuteron glasses is the presence of an inherent random field resulting from substitutional disorder which linearly couples to the O-D--O pseudo spins. In these systems we do not deal with a transition from a paraelectric to a pseudo-spin glass phase but rather with a transition from an ergodic pseudo-spin glass phase with a single order parameter q to a non-ergodic pseudo-spin glass phase with an infinite number of order parameters. (author). 11 refs.; 6 figs

  20. Measurements of proton energy spectra using a radiochromic film stack

    Science.gov (United States)

    Filkins, T. M.; Steidle, Jessica; Ellison, D. M.; Steidle, Jeffrey; Freeman, C. G.; Padalino, S. J.; Fiksel, G.; Regan, S. P.; Sangster, T. C.

    2014-10-01

    The energy spectrum of protons accelerated from the rear-side of a thin foil illuminated with ultra-intense laser light from the OMEGA EP laser system at the University of Rochester's Laboratory for Laser Energetics (LLE) was measured using a stack of radiochromic film (RCF). The film stack consisted of four layers of Gafchromic HD-V2 film and four layers of Gafchromic MD-V2-55 film. Aluminum foils of various thicknesses were placed between each piece of RCF in the stack. This arrangement allowed protons with energies of 30 MeV to reach the back layer of RCF in the stack. The stack was placed in the detector plane of a Thomson parabola ion energy (TPIE) spectrometer. Each piece of film in the stack was scanned using a commercially available flat-bed scanner (Epson 10000XL). The resulting optical density was converted into proton fluence using an absolute calibration of the RCF obtained at the SUNY Geneseo 1.7 MV Pelletron accelerator laboratory. In these calibration measurements, the sensitivity of the radiochromic film was measured using monoenergetic protons produced by the accelerator. Details of the analysis procedure and the resulting proton energy spectra will be presented. Funded in part by a grant from the DOE through the Laboratory for Laser Energetics.

  1. Facilitated assignment of large protein NMR signals with covariance sequential spectra using spectral derivatives.

    Science.gov (United States)

    Harden, Bradley J; Nichols, Scott R; Frueh, Dominique P

    2014-09-24

    Nuclear magnetic resonance (NMR) studies of larger proteins are hampered by difficulties in assigning NMR resonances. Human intervention is typically required to identify NMR signals in 3D spectra, and subsequent procedures depend on the accuracy of this so-called peak picking. We present a method that provides sequential connectivities through correlation maps constructed with covariance NMR, bypassing the need for preliminary peak picking. We introduce two novel techniques to minimize false correlations and merge the information from all original 3D spectra. First, we take spectral derivatives prior to performing covariance to emphasize coincident peak maxima. Second, we multiply covariance maps calculated with different 3D spectra to destroy erroneous sequential correlations. The maps are easy to use and can readily be generated from conventional triple-resonance experiments. Advantages of the method are demonstrated on a 37 kDa nonribosomal peptide synthetase domain subject to spectral overlap.

  2. Nuclear Magnetic Resonance Spectroscopy Applications: Proton NMR In Biological Objects Subjected To Magic Angle Spinning

    International Nuclear Information System (INIS)

    Wind, Robert A.; Hu, Jian Zhi

    2005-01-01

    Proton NMR in Biological Objects Submitted to Magic Angle Spinning, In Encyclopedia of Analytical Science, Second Edition (Paul J. Worsfold, Alan Townshend and Colin F. Poole, eds.), Elsevier, Oxford 6:333-342. Published January 1, 2005. Proposal Number 10896

  3. Microcomputer utilization for comparison of 1H-NMR spectra with data base standards

    International Nuclear Information System (INIS)

    Vale Rodrigues, G. do; Nagem, T.J.

    1989-01-01

    A new computacional technique for the storage of spectrometric data of natural products listed in the literature and its comparison with data of new compounds isolated as natural products is described here. The programs allow a correlation of two spectra by inverting one relative to the other. The programs again permit the comparison of two NMR spectra in different frequencies. (author) [pt

  4. Median Modified Wiener Filter for nonlinear adaptive spatial denoising of protein NMR multidimensional spectra

    KAUST Repository

    Cannistraci, Carlo Vittorio

    2015-01-26

    Denoising multidimensional NMR-spectra is a fundamental step in NMR protein structure determination. The state-of-the-art method uses wavelet-denoising, which may suffer when applied to non-stationary signals affected by Gaussian-white-noise mixed with strong impulsive artifacts, like those in multi-dimensional NMR-spectra. Regrettably, Wavelet\\'s performance depends on a combinatorial search of wavelet shapes and parameters; and multi-dimensional extension of wavelet-denoising is highly non-trivial, which hampers its application to multidimensional NMR-spectra. Here, we endorse a diverse philosophy of denoising NMR-spectra: less is more! We consider spatial filters that have only one parameter to tune: the window-size. We propose, for the first time, the 3D extension of the median-modified-Wiener-filter (MMWF), an adaptive variant of the median-filter, and also its novel variation named MMWF*. We test the proposed filters and the Wiener-filter, an adaptive variant of the mean-filter, on a benchmark set that contains 16 two-dimensional and three-dimensional NMR-spectra extracted from eight proteins. Our results demonstrate that the adaptive spatial filters significantly outperform their non-adaptive versions. The performance of the new MMWF* on 2D/3D-spectra is even better than wavelet-denoising. Noticeably, MMWF* produces stable high performance almost invariant for diverse window-size settings: this signifies a consistent advantage in the implementation of automatic pipelines for protein NMR-spectra analysis.

  5. Median Modified Wiener Filter for nonlinear adaptive spatial denoising of protein NMR multidimensional spectra

    KAUST Repository

    Cannistraci, Carlo Vittorio; Abbas, Ahmed; Gao, Xin

    2015-01-01

    Denoising multidimensional NMR-spectra is a fundamental step in NMR protein structure determination. The state-of-the-art method uses wavelet-denoising, which may suffer when applied to non-stationary signals affected by Gaussian-white-noise mixed with strong impulsive artifacts, like those in multi-dimensional NMR-spectra. Regrettably, Wavelet's performance depends on a combinatorial search of wavelet shapes and parameters; and multi-dimensional extension of wavelet-denoising is highly non-trivial, which hampers its application to multidimensional NMR-spectra. Here, we endorse a diverse philosophy of denoising NMR-spectra: less is more! We consider spatial filters that have only one parameter to tune: the window-size. We propose, for the first time, the 3D extension of the median-modified-Wiener-filter (MMWF), an adaptive variant of the median-filter, and also its novel variation named MMWF*. We test the proposed filters and the Wiener-filter, an adaptive variant of the mean-filter, on a benchmark set that contains 16 two-dimensional and three-dimensional NMR-spectra extracted from eight proteins. Our results demonstrate that the adaptive spatial filters significantly outperform their non-adaptive versions. The performance of the new MMWF* on 2D/3D-spectra is even better than wavelet-denoising. Noticeably, MMWF* produces stable high performance almost invariant for diverse window-size settings: this signifies a consistent advantage in the implementation of automatic pipelines for protein NMR-spectra analysis.

  6. Stable polyfluorinated cycloalkenyl cations and their NMR spectra

    International Nuclear Information System (INIS)

    Snegirev, V.F.; Galakhov, M.V.; Makarov, K.N.; Bakhmutov, V.I.

    1986-01-01

    New stable 1-methoxyperfluoro-2-ethylcyclobutenyl, 1-methoxyperfluoro-2-methylcyclo-pentenyl, and 1-methoxyperfluoro-2-ethylcyclohexenyl cations were obtained by the action of antimony pentafluoride on the corresponding olefins. The distribution of the charges in the investigated polyfluorinated cycloalkenyl cations was investigated by 13 C NMR method

  7. Analysis of human muscle extracts by proton NMR

    International Nuclear Information System (INIS)

    Venkatasubramanian, P.N.; Barany, M.; Arus, C.

    1986-01-01

    Perchloric acid extracts were prepared from pooled human muscle biopsies from patients diagnosed with scoliosis (SCOL) and cerebral palsy (CP). After neutralization with KOH and removal of perchlorate, the extracts were concentrated by freeze drying and dissolved in 2 H 2 O to contain 120 O.D. units at 280 nm per 0.5 ml. 1 H NMR spectroscopy was performed with the 5 mm probe of a Varian XL300 instrument. Creatine, lactate, carnosine, and choline were the major resonances in the one-dimensional spectra of both extracts. With creatine as reference, 2.5-fold more lactate was found in SCOL than in CP, and a much smaller difference was also found in their carnosine content. Two-dimensional COSY comparison revealed several differences between the two extracts. Taurine, N-acetyl glutamate, glycerophosphoryl choline (or phosphoryl choline) and an unidentified spot were present only in the extract from SCOL but not in that from CP. On the other hand, aspartate, hydroxy-proline, carnitine and glycerophosphoryl ethanolamine were only present in CP but absent in SCOL. Alanine, cysteine, lysine and arginine appeared in both extracts without an apparent intensity difference

  8. Suppression of Protonated Organic Solvents in NMR Spectroscopy Using a Perfect Echo Low-Pass Filtration Pulse Sequence.

    Science.gov (United States)

    Howe, Peter W A

    2018-04-03

    Proton NMR spectra are usually acquired using deuterated solvents, but in many cases it is necessary to obtain spectra on samples in protonated solvents. In these cases, the intense resonances of the protonated solvents need to be suppressed to maximize sensitivity and spectral quality. A wide range of highly effective solvent suppression methods have been developed, but additional measures are needed to suppress the 13 C satellites of the solvent. Because the satellites represent 1.1% of the original solvent signal, they remain problematic if unsuppressed. The recently proposed DISPEL pulse sequences suppress 13 C satellites extremely effectively, and this Technical Note demonstrates that combining DISPEL and presaturation results in exceptionally effective solvent suppression. An important element in the effectiveness is volume selection, which is inherent within the DISPEL sequence. Spectra acquired in protonated dimethlysulfoxide and tetrahydrofuran show that optimum results are obtained by modifying the phase cycle, cycling the pulse-field gradients, and using broadband 13 C inversion pulses to reduce the effects of radiofrequency offset and inhomogeneity.

  9. Quantitative Quantum Mechanical Spectral Analysis (qQMSA) of (1)H NMR spectra of complex mixtures and biofluids.

    Science.gov (United States)

    Tiainen, Mika; Soininen, Pasi; Laatikainen, Reino

    2014-05-01

    The quantitative interpretation of (1)H NMR spectra of mixtures like the biofluids is a demanding task due to spectral complexity and overlap. Complications may arise also from water suppression, T2-editing, protein interactions, relaxation differences of the species, experimental artifacts and, furthermore, the spectra may contain unknown components and macromolecular background which cannot be easily separated from baseline. In this work, tools and strategies for quantitative Quantum Mechanical Spectral Analysis (qQMSA) of (1)H NMR spectra from complex mixtures were developed and systematically assessed. In the present approach, the signals of well-defined, stoichiometric components are described by a QM model, while the background is described by a multiterm baseline function and the unknown signals using optimizable and adjustable lines, regular multiplets or any spectral structures which can be composed from spectral lines. Any prior knowledge available from the spectrum can also be added to the model. Fitting strategies for weak and strongly overlapping spectral systems were developed and assessed using two basic model systems, the metabolite mixtures without and with macromolecular (serum) background. The analyses show that if the spectra are measured in high-throughput manner, the consistent absolute quantification demands some calibration to compensate the different response factors of the protons and compounds. On the other hand, the results show that also the T2-edited spectra can be measured so that they obey well the QM rules. In general, qQMSA exploits and interprets the spectral information in maximal way taking full advantage from the QM properties of the spectra and, at the same time, offers chemical confidence which means that individual components can be identified with high confidence on the basis of their accurate spectral parameters. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Proton NMR studies of creatine in human erythrocytes

    Energy Technology Data Exchange (ETDEWEB)

    Kuchel, P W; Chapman, B E [Sydney Univ. (Australia). Dept. of Biochemistry

    1983-09-01

    Proton spin-echo nuclear magnetic resonance spectroscopy was used to measure the relative levels of some metabolites in intact human erythrocytes that had been fractionated by density gradient centrifugation. Age dependent changes in the concentrations of free glycine, choline and ergothioneine were seen for the first time, while glutathione was essentially invariant. In addition, there was a 10-fold decrease in creatine levels from the youngest to oldest cells. This confirms earlier reports and provides a simple explanation for the variable creatine resonance intensities seen in spectra obtained from different erythrocyte samples prepared from the same donor. The different chemical shifts of the methylene resonances of creatine and creatine phosphate was demonstrated and hence confirmed that the bulk of the creatine in intact erythrocytes is not phosphorylated. The chemical shift difference enabled the monitoring of the creatine phosphokinase catalysed reaction in lysates to which the rabbit muscle enzyme had been added. This experiment indicated that the enzyme is not significantly inhibited by factors in the lysates, and introduced a new means of assaying the in situ activity of the enzyme.

  11. Proton NMR studies of creatine in human erythrocytes

    International Nuclear Information System (INIS)

    Kuchel, P.W.; Chapman, B.E.

    1983-01-01

    Proton spin-echo nuclear magnetic resonance spectroscopy was used to measure the relative levels of some metabolites in intact human erythrocytes that had been fractionated by density gradient centrifugation. Age dependent changes in the concentrations of free glycine, choline and ergothioneine were seen for the first time, while glutathione was essentially invariant. In addition, there was a 10-fold decrease in creatine levels from the youngest to oldest cells. This confirms earlier reports and provides a simple explanation for the variable creatine resonance intensities seen in spectra obtained from different erythrocyte samples prepared from the same donor. The different chemical shifts of the methylene resonances of creatine and creatine phosphate was demonstrated and hence confirmed that the bulk of the creatine in intact erythrocytes is not phosphorylated. The chemical shift difference enabled the monitoring of the creatine phosphokinase catalysed reaction in lysates to which the rabbit muscle enzyme had been added. This experiment indicated that the enzyme is not significantly inhibited by factors in the lysates, and introduced a new means of assaying the in situ activity of the enzyme. (author)

  12. PR-CALC: A Program for the Reconstruction of NMR Spectra from Projections

    International Nuclear Information System (INIS)

    Coggins, Brian E.; Zhou Pei

    2006-01-01

    Projection-reconstruction NMR (PR-NMR) has attracted growing attention as a method for collecting multidimensional NMR data rapidly. The PR-NMR procedure involves measuring lower-dimensional projections of a higher-dimensional spectrum, which are then used for the mathematical reconstruction of the full spectrum. We describe here the program PR-CALC, for the reconstruction of NMR spectra from projection data. This program implements a number of reconstruction algorithms, highly optimized to achieve maximal performance, and manages the reconstruction process automatically, producing either full spectra or subsets, such as regions or slices, as requested. The ability to obtain subsets allows large spectra to be analyzed by reconstructing and examining only those subsets containing peaks, offering considerable savings in processing time and storage space. PR-CALC is straightforward to use, and integrates directly into the conventional pipeline for data processing and analysis. It was written in standard C+ + and should run on any platform. The organization is flexible, and permits easy extension of capabilities, as well as reuse in new software. PR-CALC should facilitate the widespread utilization of PR-NMR in biomedical research

  13. Very local interstellar spectra for galactic electrons, protons and helium

    Energy Technology Data Exchange (ETDEWEB)

    Potgieter, Marius S., E-mail: Marius.Potgieter@nwu.ac.za [Centre for Space Research, North-West University (South Africa)

    2014-07-01

    The local interstellar spectra (LIS) for cosmic rays at energies below ∼30 GeV/nuc are increasingly obscured from view at Earth by solar modulation, the lower the energy becomes. These charged particles encounter significant changes in the heliosphere, over an 11-year cycle, which include processes such as convection, diffusion, adiabatic energy losses and gradient, curvature and current sheet drifts. Particle drifts cause charge-sign-dependent modulation and a 22-year cycle, adding complexity to determining the respective very LIS from observations only at Earth. However, with measurements now made by the Voyager 1 spacecraft in the vicinity of the helio pause, it is possible to determine a very LIS for galactic electrons between ∼5 and ∼120 MeV. At these low energies, also galactic protons observed in the outer heliosphere had been completely obscured by the so-called anomalous component which is accelerated inside the helio sheath. Since August 2012, these anomalous cosmic rays are substantially depleted at Voyager 1 so that for cosmic ray ions, it is now possible to obtain a lower limit to their very LIS. Combining numerical modelling of solar modulation with the accurate measurements by the PAMELA mission and with Voyager observations, the lower limit of the very LIS for electrons, protons and helium and other ions can be determined from ∼5 MeV and above. These spectra are called helio pause spectra which is considered to be the lowest possible very LIS. Also, from an astrophysics point of view, the determination of what can be called a very LIS, not just an averaged galactic spectrum, is encouraging. The mentioned aspects are discussed, focusing on a comparison of recent heliospheric observations and corresponding solar modulation modelling. (author)

  14. Bayesian deconvolution and quantification of metabolites in complex 1D NMR spectra using BATMAN.

    Science.gov (United States)

    Hao, Jie; Liebeke, Manuel; Astle, William; De Iorio, Maria; Bundy, Jacob G; Ebbels, Timothy M D

    2014-01-01

    Data processing for 1D NMR spectra is a key bottleneck for metabolomic and other complex-mixture studies, particularly where quantitative data on individual metabolites are required. We present a protocol for automated metabolite deconvolution and quantification from complex NMR spectra by using the Bayesian automated metabolite analyzer for NMR (BATMAN) R package. BATMAN models resonances on the basis of a user-controllable set of templates, each of which specifies the chemical shifts, J-couplings and relative peak intensities for a single metabolite. Peaks are allowed to shift position slightly between spectra, and peak widths are allowed to vary by user-specified amounts. NMR signals not captured by the templates are modeled non-parametrically by using wavelets. The protocol covers setting up user template libraries, optimizing algorithmic input parameters, improving prior information on peak positions, quality control and evaluation of outputs. The outputs include relative concentration estimates for named metabolites together with associated Bayesian uncertainty estimates, as well as the fit of the remainder of the spectrum using wavelets. Graphical diagnostics allow the user to examine the quality of the fit for multiple spectra simultaneously. This approach offers a workflow to analyze large numbers of spectra and is expected to be useful in a wide range of metabolomics studies.

  15. Measuring proton shift tensors with ultrafast MAS NMR.

    Science.gov (United States)

    Miah, Habeeba K; Bennett, David A; Iuga, Dinu; Titman, Jeremy J

    2013-10-01

    A new proton anisotropic-isotropic shift correlation experiment is described which operates with ultrafast MAS, resulting in good resolution of isotropic proton shifts in the detection dimension. The new experiment makes use of a recoupling sequence designed using symmetry principles which reintroduces the proton chemical shift anisotropy in the indirect dimension. The experiment has been used to measure the proton shift tensor parameters for the OH hydrogen-bonded protons in tyrosine·HCl and citric acid at Larmor frequencies of up to 850 MHz. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. 13C NMR spectra and bonding situation of the B-C bond in alkynylboranes

    International Nuclear Information System (INIS)

    Yamamoto, Yoshinori; Moritani, Ichiro

    1975-01-01

    13 C NMR spectra of boron substituted alkynes reveal that the β-carbon is deshielded by ca. 21 ppm by a B(O-n-C 4 H 9 ) 2 group. This clearly indicates the presence of a B-C π-bonding in alkynylboranes. (auth.)

  17. NMRNet: A deep learning approach to automated peak picking of protein NMR spectra.

    Science.gov (United States)

    Klukowski, Piotr; Augoff, Michal; Zieba, Maciej; Drwal, Maciej; Gonczarek, Adam; Walczak, Michal J

    2018-03-14

    Automated selection of signals in protein NMR spectra, known as peak picking, has been studied for over 20 years, nevertheless existing peak picking methods are still largely deficient. Accurate and precise automated peak picking would accelerate the structure calculation, and analysis of dynamics and interactions of macromolecules. Recent advancement in handling big data, together with an outburst of machine learning techniques, offer an opportunity to tackle the peak picking problem substantially faster than manual picking and on par with human accuracy. In particular, deep learning has proven to systematically achieve human-level performance in various recognition tasks, and thus emerges as an ideal tool to address automated identification of NMR signals. We have applied a convolutional neural network for visual analysis of multidimensional NMR spectra. A comprehensive test on 31 manually-annotated spectra has demonstrated top-tier average precision (AP) of 0.9596, 0.9058 and 0.8271 for backbone, side-chain and NOESY spectra, respectively. Furthermore, a combination of extracted peak lists with automated assignment routine, FLYA, outperformed other methods, including the manual one, and led to correct resonance assignment at the levels of 90.40%, 89.90% and 90.20% for three benchmark proteins. The proposed model is a part of a Dumpling software (platform for protein NMR data analysis), and is available at https://dumpling.bio/. michaljerzywalczak@gmail.compiotr.klukowski@pwr.edu.pl. Supplementary data are available at Bioinformatics online.

  18. Temperature dependence of broadline NMR spectra of water-soaked, epoxy-graphite composites

    Science.gov (United States)

    Lawing, David; Fornes, R. E.; Gilbert, R. D.; Memory, J. D.

    1981-10-01

    Water-soaked, epoxy resin-graphite fiber composites show a waterline in their broadline proton NMR spectrum which indicates a state of intermediate mobility between the solid and free water liquid states. The line is still present at -42 °C, but shows a reversible decrease in amplitude with decreasing temperature. The line is isotropic upon rotation of the fiber axis with respect to the external magnetic field.

  19. Metabolic profiling of vitamin C deficiency in Gulo-/- mice using proton NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Duggan, Gavin E. [University of Calgary, Biochemistry Research Group, Department of Biological Sciences (Canada); Joan Miller, B.; Jirik, Frank R. [University of Calgary, Department of Biochemistry and Molecular Biology, The McCaig Institute for Bone and Joint Health (Canada); Vogel, Hans J., E-mail: vogel@ucalgary.ca [University of Calgary, Biochemistry Research Group, Department of Biological Sciences (Canada)

    2011-04-15

    Nutrient deficiencies are an ongoing problem in many populations and ascorbic acid is a key vitamin whose mild or acute absence leads to a number of conditions including the famously debilitating scurvy. As such, the biochemical effects of ascorbate deficiency merit ongoing scrutiny, and the Gulo knockout mouse provides a useful model for the metabolomic examination of vitamin C deficiency. Like humans, these animals are incapable of synthesizing ascorbic acid but with dietary supplements are otherwise healthy and grow normally. In this study, all vitamin C sources were removed after weaning from the diet of Gulo-/- mice (n = 7) and wild type controls (n = 7) for 12 weeks before collection of serum. A replicate study was performed with similar parameters but animals were harvested pre-symptomatically after 2-3 weeks. The serum concentration of 50 metabolites was determined by quantitative profiling of 1D proton NMR spectra. Multivariate statistical models were used to describe metabolic changes as compared to control animals; replicate study animals were used for external validation of the resulting models. The results of the study highlight the metabolites and pathways known to require ascorbate for proper flux.

  20. Metabolic profiling of vitamin C deficiency in Gulo−/− mice using proton NMR spectroscopy

    International Nuclear Information System (INIS)

    Duggan, Gavin E.; Joan Miller, B.; Jirik, Frank R.; Vogel, Hans J.

    2011-01-01

    Nutrient deficiencies are an ongoing problem in many populations and ascorbic acid is a key vitamin whose mild or acute absence leads to a number of conditions including the famously debilitating scurvy. As such, the biochemical effects of ascorbate deficiency merit ongoing scrutiny, and the Gulo knockout mouse provides a useful model for the metabolomic examination of vitamin C deficiency. Like humans, these animals are incapable of synthesizing ascorbic acid but with dietary supplements are otherwise healthy and grow normally. In this study, all vitamin C sources were removed after weaning from the diet of Gulo−/− mice (n = 7) and wild type controls (n = 7) for 12 weeks before collection of serum. A replicate study was performed with similar parameters but animals were harvested pre-symptomatically after 2–3 weeks. The serum concentration of 50 metabolites was determined by quantitative profiling of 1D proton NMR spectra. Multivariate statistical models were used to describe metabolic changes as compared to control animals; replicate study animals were used for external validation of the resulting models. The results of the study highlight the metabolites and pathways known to require ascorbate for proper flux.

  1. Two- and three-dimensional proton NMR studies of apo-neocarzinostatin

    International Nuclear Information System (INIS)

    Xiaolian Gao; Burkhart, W.

    1991-01-01

    Neocarzinostatin (NCS) is an antitumor protein from Streptomyces carzinostaticus that is identical in apo-protein sequence with mitomalcin (MMC) from Streptomyces malayensis. The authors describe the use of apo-NCS as a model system for applying combined two-and three-dimensional (2D and 3D) proton NMR spectroscopy to the structure determination of proteins without isotope labeling. Strategies aimed at accurately assigning overlapped 2D cross-peaks by using semiautomated combined 2D and 3D data analysis are developed. Using this approach, they have assigned 99% of the protons, including those of the side chains, and identified about 1,270 intra- and interresidue proton-proton interactions (fixed distances are not included) in apo-NCS. Comparing these results with those reported recently on 2D NMR studies of apo-NCS demonstrated advantages of proton 3D NMR spectroscopy in protein spectral assignments. They are able to obtain more complete proton resonance and secondary structural assignments and find several misassignments in the earlier report. Strategies utilized in this work should be useful for developing automation procedures for spectral assignments

  2. Solid-state NMR analysis of membrane proteins and protein aggregates by proton detected spectroscopy

    International Nuclear Information System (INIS)

    Zhou, Donghua H.; Nieuwkoop, Andrew J.; Berthold, Deborah A.; Comellas, Gemma; Sperling, Lindsay J.; Tang, Ming; Shah, Gautam J.; Brea, Elliott J.; Lemkau, Luisel R.; Rienstra, Chad M.

    2012-01-01

    Solid-state NMR has emerged as an important tool for structural biology and chemistry, capable of solving atomic-resolution structures for proteins in membrane-bound and aggregated states. Proton detection methods have been recently realized under fast magic-angle spinning conditions, providing large sensitivity enhancements for efficient examination of uniformly labeled proteins. The first and often most challenging step of protein structure determination by NMR is the site-specific resonance assignment. Here we demonstrate resonance assignments based on high-sensitivity proton-detected three-dimensional experiments for samples of different physical states, including a fully-protonated small protein (GB1, 6 kDa), a deuterated microcrystalline protein (DsbA, 21 kDa), a membrane protein (DsbB, 20 kDa) prepared in a lipid environment, and the extended core of a fibrillar protein (α-synuclein, 14 kDa). In our implementation of these experiments, including CONH, CO(CA)NH, CANH, CA(CO)NH, CBCANH, and CBCA(CO)NH, dipolar-based polarization transfer methods have been chosen for optimal efficiency for relatively high protonation levels (full protonation or 100 % amide proton), fast magic-angle spinning conditions (40 kHz) and moderate proton decoupling power levels. Each H–N pair correlates exclusively to either intra- or inter-residue carbons, but not both, to maximize spectral resolution. Experiment time can be reduced by at least a factor of 10 by using proton detection in comparison to carbon detection. These high-sensitivity experiments are especially important for membrane proteins, which often have rather low expression yield. Proton-detection based experiments are expected to play an important role in accelerating protein structure elucidation by solid-state NMR with the improved sensitivity and resolution.

  3. CASD-NMR 2: robust and accurate unsupervised analysis of raw NOESY spectra and protein structure determination with UNIO

    International Nuclear Information System (INIS)

    Guerry, Paul; Duong, Viet Dung; Herrmann, Torsten

    2015-01-01

    UNIO is a comprehensive software suite for protein NMR structure determination that enables full automation of all NMR data analysis steps involved—including signal identification in NMR spectra, sequence-specific backbone and side-chain resonance assignment, NOE assignment and structure calculation. Within the framework of the second round of the community-wide stringent blind NMR structure determination challenge (CASD-NMR 2), we participated in two categories of CASD-NMR 2, namely using either raw NMR spectra or unrefined NOE peak lists as input. A total of 15 resulting NMR structure bundles were submitted for 9 out of 10 blind protein targets. All submitted UNIO structures accurately coincided with the corresponding blind targets as documented by an average backbone root mean-square deviation to the reference proteins of only 1.2 Å. Also, the precision of the UNIO structure bundles was virtually identical to the ensemble of reference structures. By assessing the quality of all UNIO structures submitted to the two categories, we find throughout that only the UNIO–ATNOS/CANDID approach using raw NMR spectra consistently yielded structure bundles of high quality for direct deposition in the Protein Data Bank. In conclusion, the results obtained in CASD-NMR 2 are another vital proof for robust, accurate and unsupervised NMR data analysis by UNIO for real-world applications

  4. NMR evidence for protonated tetraethyl p-tert-butylcalix[4]arene tetracacetate

    Czech Academy of Sciences Publication Activity Database

    Kříž, Jaroslav; Dybal, Jiří; Makrlík, E.; Vaňura, P.

    2007-01-01

    Roč. 81, č. 7 (2007), s. 1321-1326 ISSN 0137- 5083 Institutional research plan: CEZ:AV0Z40500505 Keywords : calix[4]arene * protonation * NMR * acetonitrile Subject RIV: CC - Organic Chemistry Impact factor: 0.483, year: 2007

  5. MetIDB: A Publicly Accessible Database of Predicted and Experimental 1H NMR Spectra of Flavonoids

    NARCIS (Netherlands)

    Mihaleva, V.V.; Beek, te T.A.; Zimmeren, van F.; Moco, S.I.A.; Laatikainen, R.; Niemitz, M.; Korhonen, S.P.; Driel, van M.A.; Vervoort, J.

    2013-01-01

    Identification of natural compounds, especially secondary metabolites, has been hampered by the lack of easy to use and accessible reference databases. Nuclear magnetic resonance (NMR) spectroscopy is the most selective technique for identification of unknown metabolites. High quality 1H NMR (proton

  6. 1H nmr spectra of dichloro and dihydroxy derivatives of methylcyclosiloxanes

    International Nuclear Information System (INIS)

    Lavrukhin, B.D.

    1986-01-01

    The authors report on a continuation of an investigation of how the nature of the substituents on the Si atoms influences the character of the spectra. As objects of investigation, the authors took the dichloro and dihydroxy derivatives of cyclosiloxanes with 4 to 8 Si atoms in the ring. Shown are tables of chemical shifts of protons of CH 3 groups in chloromethylcyclosiloxanes, and chemical shifts of protons of CH 3 groups in linear methylsiloxanes and chloromethylsiloxanes. Additivity was demonstrated for chemical shifts of CH 3 group protons in dichloromethylcyclosiloxanes, and the increments of chemical shift were obtained for 8-, 10-, 12-, 14-, and 16-membered rings. It was established that the chemical shifts in the spectra of the dihydroxy derivatives are nonadditive

  7. Preliminary analysis of proton magnetic resonance 1D spectra of cerebrospinal fluid and brain cancer extracts

    International Nuclear Information System (INIS)

    Toczylowska, B.; Jozwik, A.; Kierul, K.; Matysiak, Z.; Sidor, M.; Wojcik, J.

    1999-01-01

    In series of cerebrospinal fluid samples from 25 patients proton spectra of magnetic resonance were measured. The spectra were measured also for series of brain tumor tissue extracts received from another 25 patients. This paper presents an attempt to apply statistical methods of image recognition for spectra analysis of the two measured series

  8. Characterization of E and Z isomers in macrocyclic lactones and acyclic pheromones by NMR spectra

    International Nuclear Information System (INIS)

    Mahajan, J.R.; Resck, I.S.; Braz Filho, R.; Carvalho, M.G. de

    1995-01-01

    A large proportion of pheromones, isolated from a variety of insects, constitutes a big list of diversely functionalized acyclic compounds, which have been synthesized by several routes. Catalytic or chemical methods were examined for the Z to E isomerization and their efficiency checked by 1 H and 13 C NMR spectra. Nuclear magnetic resonance has been used to identify and characterize molecular structure of the compounds, besides chemical shifts was analysed

  9. Proton NMR studies on Megaphaera elsdenii flavodoxin : structure elucidation by 2D-NMR and implications

    NARCIS (Netherlands)

    Mierlo, van C.

    1990-01-01

    1H NMR techniques have been applied for a thorough study of the uncrystallizable Megasphaera elsdenii flavodoxin in its three redox states. The aim of the research project described in this thesis was to obtain answers regarding questions

  10. NMR studies of proton exchange kinetics in aqueous formaldehyde solutions.

    Science.gov (United States)

    Rivlin, Michal; Eliav, Uzi; Navon, Gil

    2014-05-01

    Aqueous solutions of formaldehyde, formalin, are commonly used for tissue fixation and preservation. Treatment with formalin is known to shorten the tissue transverse relaxation time T2. Part of this shortening is due to the effect of formalin on the water T2. In the present work we show that the shortening of water T2 is a result of proton exchange between water and the major constituent of aqueous solutions of formaldehyde, methylene glycol. We report the observation of the signal of the hydroxyl protons of methylene glycol at 2ppm to high frequency of the water signal that can be seen at low temperatures and at pH range of 6.0±1.5 and, at conditions where it cannot be observed by the single pulse experiment, it can be detected indirectly through the water signal by the chemical exchange saturation transfer (CEST) experiment. The above finding made it possible to obtain the exchange rate between the hydroxyl protons of the methylene glycol and water in aqueous formaldehyde solutions, either using the dispersion of the spin-lattice relaxation rate in the rotating frame (1/T1ρ) or, at the slow exchange regime, from the line width hydroxyl protons of methylene glycol. The exchange rate was ∼10(4)s(-1) at pH 7.4 and 37°C, the activation energy, 50.2kJ/mol and its pH dependence at 1.1°C was fitted to: k (s(-1))=520+6.5×10(7)[H(+)]+3.0×10(9)[OH(-)]. Copyright © 2014. Published by Elsevier Inc.

  11. Fast acquisition of multidimensional NMR spectra of solids and mesophases using alternative sampling methods.

    Science.gov (United States)

    Lesot, Philippe; Kazimierczuk, Krzysztof; Trébosc, Julien; Amoureux, Jean-Paul; Lafon, Olivier

    2015-11-01

    Unique information about the atom-level structure and dynamics of solids and mesophases can be obtained by the use of multidimensional nuclear magnetic resonance (NMR) experiments. Nevertheless, the acquisition of these experiments often requires long acquisition times. We review here alternative sampling methods, which have been proposed to circumvent this issue in the case of solids and mesophases. Compared to the spectra of solutions, those of solids and mesophases present some specificities because they usually display lower signal-to-noise ratios, non-Lorentzian line shapes, lower spectral resolutions and wider spectral widths. We highlight herein the advantages and limitations of these alternative sampling methods. A first route to accelerate the acquisition time of multidimensional NMR spectra consists in the use of sparse sampling schemes, such as truncated, radial or random sampling ones. These sparsely sampled datasets are generally processed by reconstruction methods differing from the Discrete Fourier Transform (DFT). A host of non-DFT methods have been applied for solids and mesophases, including the G-matrix Fourier transform, the linear least-square procedures, the covariance transform, the maximum entropy and the compressed sensing. A second class of alternative sampling consists in departing from the Jeener paradigm for multidimensional NMR experiments. These non-Jeener methods include Hadamard spectroscopy as well as spatial or orientational encoding of the evolution frequencies. The increasing number of high field NMR magnets and the development of techniques to enhance NMR sensitivity will contribute to widen the use of these alternative sampling methods for the study of solids and mesophases in the coming years. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Simplifying the complex 1H NMR spectra of fluorine-substituted benzamides by spin system filtering and spin-state selection: multiple-quantum-single-quantum correlation.

    Science.gov (United States)

    Baishya, Bikash; Reddy, G N Manjunatha; Prabhu, Uday Ramesh; Row, T N Guru; Suryaprakash, N

    2008-10-23

    The proton NMR spectra of fluorine-substituted benzamides are very complex (Figure 1) due to severe overlap of (1)H resonances from the two aromatic rings, in addition to several short and long-range scalar couplings experienced by each proton. With no detectable scalar couplings between the inter-ring spins, the (1)H NMR spectra can be construed as an overlap of spectra from two independent phenyl rings. In the present study we demonstrate that it is possible to separate the individual spectrum for each aromatic ring by spin system filtering employing the multiple-quantum-single-quantum correlation methodology. Furthermore, the two spin states of fluorine are utilized to simplify the spectrum corresponding to each phenyl ring by the spin-state selection. The demonstrated technique reduces spectral complexity by a factor of 4, in addition to permitting the determination of long-range couplings of less than 0.2 Hz and the relative signs of heteronuclear couplings. The technique also aids the judicious choice of the spin-selective double-quantum-single-quantum J-resolved experiment to determine the long-range homonuclear couplings of smaller magnitudes.

  13. Distinguishing Vaccinium species by chemical fingerprinting based on NMR spectra, validated with spectra collected in different laboratories.

    Science.gov (United States)

    Markus, Michelle A; Ferrier, Jonathan; Luchsinger, Sarah M; Yuk, Jimmy; Cuerrier, Alain; Balick, Michael J; Hicks, Joshua M; Killday, K Brian; Kirby, Christopher W; Berrue, Fabrice; Kerr, Russell G; Knagge, Kevin; Gödecke, Tanja; Ramirez, Benjamin E; Lankin, David C; Pauli, Guido F; Burton, Ian; Karakach, Tobias K; Arnason, John T; Colson, Kimberly L

    2014-06-01

    A method was developed to distinguish Vaccinium species based on leaf extracts using nuclear magnetic resonance spectroscopy. Reference spectra were measured on leaf extracts from several species, including lowbush blueberry (Vaccinium angustifolium), oval leaf huckleberry (Vaccinium ovalifolium), and cranberry (Vaccinium macrocarpon). Using principal component analysis, these leaf extracts were resolved in the scores plot. Analysis of variance statistical tests demonstrated that the three groups differ significantly on PC2, establishing that the three species can be distinguished by nuclear magnetic resonance. Soft independent modeling of class analogies models for each species also showed discrimination between species. To demonstrate the robustness of nuclear magnetic resonance spectroscopy for botanical identification, spectra of a sample of lowbush blueberry leaf extract were measured at five different sites, with different field strengths (600 versus 700 MHz), different probe types (cryogenic versus room temperature probes), different sample diameters (1.7 mm versus 5 mm), and different consoles (Avance I versus Avance III). Each laboratory independently demonstrated the linearity of their NMR measurements by acquiring a standard curve for chlorogenic acid (R(2) = 0.9782 to 0.9998). Spectra acquired on different spectrometers at different sites classifed into the expected group for the Vaccinium spp., confirming the utility of the method to distinguish Vaccinium species and demonstrating nuclear magnetic resonance fingerprinting for material validation of a natural health product. Georg Thieme Verlag KG Stuttgart · New York.

  14. The TeV-scale cosmic ray proton and helium spectra: Contributions ...

    Indian Academy of Sciences (India)

    has been proposed some time ago by Stanev et al [13] and Zatsepin and Sokolskaya .... as a stochastic variable whose probability distribution function p( ) has been studied in ... are independently adjusted to the proton and helium spectra.

  15. Magnetic resonance spectroscopy and metabolism. Applications of proton and sup 13 C NMR to the study of glutamate metabolism in cultured glial cells and human brain in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Portais, J.C.; Pianet, I.; Merle, M.; Raffard, G.; Biran, M.; Labouesse, J.; Canioni, P. (Bordeaux-2 Univ., 33 (FR)); Allard, M.; Kien, P.; Caille, J.M. (Centre Hospitalier Universitaire, 33 Bordeaux (FR))

    1991-01-01

    Nuclear magnetic resonance (NMR) spectroscopy was used to study the metabolism of cells from the central nervous system both in vitro on perchloric acid extracts obtained either from cultured tumoral cells (C6 rat glioma) or rat astrocytes in primary culture, and in vivo within the human brain. Analysis of carbon 13 NMR spectra of perchloric acid extracts prepared from cultured cells in the presence of NMR (1-{sup 13}C) glucose as substrate allowed determination of the glutamate and glutamine enrichments in both normal and tumoral cells. Preliminary results indicated large changes in the metabolism of these amino acids (and also of aspartate and alanine) in the C6 cell as compared to its normal counterpart. Localized proton NMR spectra of the human brain in vivo were obtained at 1.5 T, in order to evaluate the content of various metabolites, including glutamate, in peritumoral edema from a selected volume of 2 x 2 x 2 cm{sup 3}. N-acetyl aspartate, glutamate, phosphocreatine, creatine, choline and inositol derivative resonances were observed in 15 min spectra. N-acetyl-aspartate was found to be at a lower level in contrast to glutamate which was detected at a higher level in the injured area as compared to the controlateral unaffected side.

  16. Production spectra of π+-, K+-, p+- at large angles in proton-proton collisions in the CERN intersecting storage rings

    International Nuclear Information System (INIS)

    Alper, B.; Boeggild, H.; Booth, P.; Bulos, F.; Carroll, L.J.; Damgaard, G.; Von Dardel, G.; Duff, B.; Hansen, K.H.; Heymann, F.; Jackson, J.N.; Jarlskog, G.; Joensson, L.; Klovning, A.; Leistam, L.; Lillethun, E.; Lohse, E.; Lynch, G.; Manning, G.; Potter, K.; Prentice, M.; Sharp, P.; Sharrock, S.; Oelgaard-Nielsen, S.; Quarrie, D.; Weiss, J.M.

    1975-01-01

    Results are given on the inclusive production of charged pions, kaons, and nucleons, in proton-proton collisions at c.m. energies from √s=23 to 63 GeV at large angles and for the transverse momentum range 0.1 < psub(T) < 4.8 GeV/c. The dependence of the production spectra on the collision energy √s, the transverse momentum psub(T), and the longitudinal rapidity is discussed. (Auth.)

  17. /sup 13/C NMR spectra and electron conduction in 4-substituted diphenylamines

    Energy Technology Data Exchange (ETDEWEB)

    Filimonov, V.D.; Kogan, R.M.; Tverdokhlebova, N.E.; Shcherbakov, V.V.; Kushnarev, D.F.; Kalabin, G.A.

    1986-07-10

    The /sup 13/C NMR spectra were recorded for a series of 4-X-diphenylamines, and correlations equations relating the /sup 13/C NMR chemical shifts of the C/sup 1/ and C/sup 4/ positions to the electronic characteristics of the substituent X were obtained. It was established that the conduction of the substituted ring in the 4-X-diphenylamines is practically the same as in 4-X-biphenyls. Joint analysis of the spectral characteristics of the diphenylamines, biphenyls, N-substituted anilines, and carbazoles made it possible to conclude that the increased transmission characteristics of the diphenylamines are determined by the conformational mobility of the two benzene rings and by the unidirectional effect of changes in the introduction and resonance factors with variation in the substituent X.

  18. Spectrally edited 2D 13Csbnd 13C NMR spectra without diagonal ridge for characterizing 13C-enriched low-temperature carbon materials

    Science.gov (United States)

    Johnson, Robert L.; Anderson, Jason M.; Shanks, Brent H.; Fang, Xiaowen; Hong, Mei; Schmidt-Rohr, Klaus

    2013-09-01

    Two robust combinations of spectral editing techniques with 2D 13Csbnd 13C NMR have been developed for characterizing the aromatic components of 13C-enriched low-temperature carbon materials. One method (exchange with protonated and nonprotonated spectral editing, EXPANSE) selects cross peaks of protonated and nearby nonprotonated carbons, while the other technique, dipolar-dephased double-quantum/single-quantum (DQ/SQ) NMR, selects signals of bonded nonprotonated carbons. Both spectra are free of a diagonal ridge, which has many advantages: Cross peaks on the diagonal or of small intensity can be detected, and residual spinning sidebands or truncation artifacts associated with the diagonal ridge are avoided. In the DQ/SQ experiment, dipolar dephasing of the double-quantum coherence removes protonated-carbon signals; this approach also eliminates the need for high-power proton decoupling. The initial magnetization is generated with minimal fluctuation by combining direct polarization, cross polarization, and equilibration by 13C spin diffusion. The dipolar dephased DQ/SQ spectrum shows signals from all linkages between aromatic rings, including a distinctive peak from polycondensed aromatics. In EXPANSE NMR, signals of protonated carbons are selected in the first spectral dimension by short cross polarization combined with dipolar dephasing difference. This removes ambiguities of peak assignment to overlapping signals of nonprotonated and protonated aromatic carbons, e.g. near 125 ppm. Spin diffusion is enhanced by dipolar-assisted rotational resonance. Before detection, Csbnd H dipolar dephasing by gated decoupling is applied, which selects signals of nonprotonated carbons. Thus, only cross peaks due to magnetization originating from protonated C and ending on nearby nonprotonated C are retained. Combined with the chemical shifts deduced from the cross-peak position, this double spectral editing defines the bonding environment of aromatic, COO, and Cdbnd O carbons

  19. FoodPro: A Web-Based Tool for Evaluating Covariance and Correlation NMR Spectra Associated with Food Processes

    Directory of Open Access Journals (Sweden)

    Eisuke Chikayama

    2016-10-01

    Full Text Available Foods from agriculture and fishery products are processed using various technologies. Molecular mixture analysis during food processing has the potential to help us understand the molecular mechanisms involved, thus enabling better cooking of the analyzed foods. To date, there has been no web-based tool focusing on accumulating Nuclear Magnetic Resonance (NMR spectra from various types of food processing. Therefore, we have developed a novel web-based tool, FoodPro, that includes a food NMR spectrum database and computes covariance and correlation spectra to tasting and hardness. As a result, FoodPro has accumulated 236 aqueous (extracted in D2O and 131 hydrophobic (extracted in CDCl3 experimental bench-top 60-MHz NMR spectra, 1753 tastings scored by volunteers, and 139 hardness measurements recorded by a penetrometer, all placed into a core database. The database content was roughly classified into fish and vegetable groups from the viewpoint of different spectrum patterns. FoodPro can query a user food NMR spectrum, search similar NMR spectra with a specified similarity threshold, and then compute estimated tasting and hardness, covariance, and correlation spectra to tasting and hardness. Querying fish spectra exemplified specific covariance spectra to tasting and hardness, giving positive covariance for tasting at 1.31 ppm for lactate and 3.47 ppm for glucose and a positive covariance for hardness at 3.26 ppm for trimethylamine N-oxide.

  20. FoodPro: A Web-Based Tool for Evaluating Covariance and Correlation NMR Spectra Associated with Food Processes.

    Science.gov (United States)

    Chikayama, Eisuke; Yamashina, Ryo; Komatsu, Keiko; Tsuboi, Yuuri; Sakata, Kenji; Kikuchi, Jun; Sekiyama, Yasuyo

    2016-10-19

    Foods from agriculture and fishery products are processed using various technologies. Molecular mixture analysis during food processing has the potential to help us understand the molecular mechanisms involved, thus enabling better cooking of the analyzed foods. To date, there has been no web-based tool focusing on accumulating Nuclear Magnetic Resonance (NMR) spectra from various types of food processing. Therefore, we have developed a novel web-based tool, FoodPro, that includes a food NMR spectrum database and computes covariance and correlation spectra to tasting and hardness. As a result, FoodPro has accumulated 236 aqueous (extracted in D₂O) and 131 hydrophobic (extracted in CDCl₃) experimental bench-top 60-MHz NMR spectra, 1753 tastings scored by volunteers, and 139 hardness measurements recorded by a penetrometer, all placed into a core database. The database content was roughly classified into fish and vegetable groups from the viewpoint of different spectrum patterns. FoodPro can query a user food NMR spectrum, search similar NMR spectra with a specified similarity threshold, and then compute estimated tasting and hardness, covariance, and correlation spectra to tasting and hardness. Querying fish spectra exemplified specific covariance spectra to tasting and hardness, giving positive covariance for tasting at 1.31 ppm for lactate and 3.47 ppm for glucose and a positive covariance for hardness at 3.26 ppm for trimethylamine N -oxide.

  1. Non-destructive ripeness sensing by using proton NMR [Nuclear Magnetic Resonance

    International Nuclear Information System (INIS)

    Cho, Seong In; Krutz, G.W.; Stroshine, R.L.

    1990-01-01

    More than 80 kinds of fruits and vegetables are available in the United States. But only about 6 of them have their quality standards (Dull, 1986). In the 1990 Fresh Trends survey (Zind, 1990), consumers were asked to rate 16 characteristics important to their decision to purchase fresh produce. The four top ranking factors were ripeness/freshness, taste/flavor, appearance/condition and nutritional value. Of these surveyed, 96% rated ripeness/freshness as extremely important or very important. Therefore, the development of reliable grading or sorting techniques for fresh commodities is essential. Determination of fruit quality often involves cutting and tasting. Non-destructive quality control in fruit and vegetables is a goal of growers and distributors, as well as the food processing industry. Many nondestructive techniques have been evaluated including soft x-ray, optical transmission, near infrared radiation, and machine vision. However, there are few reports of successful non-destructive measurement of sugar content directly in fruit. Higher quality fruit could be harvested and available to consumers if a nondestructive sensor that detects ripeness level directly by measuring sugar content were available. Using proton Nuclear Magnetic Resonance (NMR) principle is the possibility. A nondestructive ripeness (or sweetness) sensor for fruit quality control can be developed with the proton NMR principle (Cho, 1989). Several feasibility studies were necessary for the ripeness sensor development. Main objectives in this paper was to investigate the feasibilities (1) to detect ripeness (or sweetness level) of raw fruit tissue with an high resolution proton NMR spectroscopy (200 MHz) and (2) to measure sugar content of intact fruit with a low resolution proton NMR spectroscopy (10 MHz). 7 refs., 4 figs

  2. Non-destructive Ripeness Sensing by Using Proton NMR [Nuclear Magnetic Resonance

    Science.gov (United States)

    Cho, Seong In; Krutz, G. W.; Stroshine, R. L.; Bellon, V.

    1990-01-01

    More than 80 kinds of fruits and vegetables are available in the United States. But only about 6 of them have their quality standards (Dull, 1986). In the 1990 Fresh Trends survey (Zind, 1990), consumers were asked to rate 16 characteristics important to their decision to purchase fresh produce. The four top ranking factors were ripeness/freshness, taste/flavor, appearance/condition and nutritional value. Of these surveyed, 96% rated ripeness/freshness as extremely important or very important. Therefore, the development of reliable grading or sorting techniques for fresh commodities is essential. Determination of fruit quality often involves cutting and tasting. Non-destructive quality control in fruit and vegetables is a goal of growers and distributors, as well as the food processing industry. Many nondestructive techniques have been evaluated including soft x-ray, optical transmission, near infrared radiation, and machine vision. However, there are few reports of successful non-destructive measurement of sugar content directly in fruit. Higher quality fruit could be harvested and available to consumers if a nondestructive sensor that detects ripeness level directly by measuring sugar content were available. Using proton Nuclear Magnetic Resonance (NMR) principle is the possibility. A nondestructive ripeness (or sweetness) sensor for fruit quality control can be developed with the proton NMR principle (Cho, 1989). Several feasibility studies were necessary for the ripeness sensor development. Main objectives in this paper was to investigate the feasibilities (1) to detect ripeness (or sweetness level) of raw fruit tissue with an high resolution proton NMR spectroscopy (200 MHz) and (2) to measure sugar content of intact fruit with a low resolution proton NMR spectroscopy (10 MHz).

  3. Automation of peak-tracking analysis of stepwise perturbed NMR spectra

    Energy Technology Data Exchange (ETDEWEB)

    Banelli, Tommaso; Vuano, Marco [Università di Udine, Dipartimento di Area Medica (Italy); Fogolari, Federico [INBB (Italy); Fusiello, Andrea [Università di Udine, Dipartimento Politecnico di Ingegneria e Architettura (Italy); Esposito, Gennaro [INBB (Italy); Corazza, Alessandra, E-mail: alessandra.corazza@uniud.it [Università di Udine, Dipartimento di Area Medica (Italy)

    2017-02-15

    We describe a new algorithmic approach able to automatically pick and track the NMR resonances of a large number of 2D NMR spectra acquired during a stepwise variation of a physical parameter. The method has been named Trace in Track (TinT), referring to the idea that a gaussian decomposition traces peaks within the tracks recognised through 3D mathematical morphology. It is capable of determining the evolution of the chemical shifts, intensity and linewidths of each tracked peak.The performances obtained in term of track reconstruction and correct assignment on realistic synthetic spectra were high above 90% when a noise level similar to that of experimental data were considered. TinT was applied successfully to several protein systems during a temperature ramp in isotope exchange experiments. A comparison with a state-of-the-art algorithm showed promising results for great numbers of spectra and low signal to noise ratios, when the graduality of the perturbation is appropriate. TinT can be applied to different kinds of high throughput chemical shift mapping experiments, with quasi-continuous variations, in which a quantitative automated recognition is crucial.

  4. Unusual features of proton and α-spectra from low-energy heavy-ion ...

    Indian Academy of Sciences (India)

    Home; Journals; Pramana – Journal of Physics; Volume 75; Issue 1. Unusual features ... Keywords. Proton and α-spectra; heavy-ion reaction; broad structures; nuclear level density. ... The broad structures in the -spectra cannot be fully explained within the statistical model even with the enhanced level density. In this case ...

  5. Acetylenes bearing Aromatic Terminal Groups. : II 13C-NMR Spectra of Monosubstituted Diphenylacetylenes

    OpenAIRE

    野本, 健雄; Nomoto, Takeo

    1986-01-01

    Six monosubstituted diphenylacetylenes, p-X-C6H4-C≡C-C6H5 1 (Ⅹ=NMe2, NH2, OMe, Cl, and NO2), were synthesized, and 13C-NMR spectra of their acetylenic carbons were measured. Hammett plots of the chemical shifts of the acetylenic α-13C and β-13C (against substituent constants σ) respectively showed a linear relationship, eXCept for β-13C on NMe2 and NH2 groups. The effects of substituents on 13C-Chemical shifts of diphenylacetylenes and effeciency of the C≡C bonds in transmitting the substitue...

  6. Nonclassical dynamics of the methyl group in 1,1,1-triphenylethane. Evidence from powder 1H NMR spectra

    KAUST Repository

    Osior, Agnieszka; Kalicki, Przemysław; Kamieński, Bohdan; Szymański, Sławomir; Bernatowicz, Piotr; Shkurenko, Aleksander

    2017-01-01

    interpretation of the DQR parameters evaluated from the spectra is given. It is shown that the DQR effects as such can be detected in wide-line NMR spectra of powdered samples, which are relatively facile to measure. However, a fully quantitative picture

  7. NMR experiments for the measurement of proton-proton and carbon-carbon residual dipolar couplings in uniformly labelled oligosaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Martin-Pastor, Manuel [Universidad de Santiago de Compostela, Laboratorio Integral de Estructura de Biomoleculas Jose. R. Carracido, Unidade de Resonancia Magnetica, RIAIDT (Spain)], E-mail: mmartin@usc.es; Canales-Mayordomo, Angeles; Jimenez-Barbero, Jesus [Departamento de Estructura y funcion de proteinas, Centro de Investigaciones Biologicas, CSIC (Spain)], E-mail: jjbarbero@cib.csic.es

    2003-08-15

    A 2D-HSQC-carbon selective/proton selective-constant time COSY, 2D-HSQC-(sel C, sel H)-CT COSY experiment, which is applicable to uniformly {sup 13}C isotopically enriched samples (U-{sup 13}C) of oligosaccharides or oligonucleotides is proposed for the measurement of proton-proton RDC in crowded regions of 2D-spectra. In addition, a heteronuclear constant time-COSY experiment, {sup 13}C-{sup 13}C CT-COSY, is proposed for the measurement of one bond carbon-carbon RDC in these molecules. These two methods provide an extension, to U-{sup 13}C molecules, of the original homonuclear constant time-COSY experiment proposed by Tian et al. (1999) for saccharides. The combination of a number of these RDC with NOE data may provide the method of choice to study oligosaccharide conformation in the free and receptor-bound state.

  8. Automated Peak Picking and Peak Integration in Macromolecular NMR Spectra Using AUTOPSY

    Science.gov (United States)

    Koradi, Reto; Billeter, Martin; Engeli, Max; Güntert, Peter; Wüthrich, Kurt

    1998-12-01

    A new approach for automated peak picking of multidimensional protein NMR spectra with strong overlap is introduced, which makes use of the program AUTOPSY (automatedpeak picking for NMRspectroscopy). The main elements of this program are a novel function for local noise level calculation, the use of symmetry considerations, and the use of lineshapes extracted from well-separated peaks for resolving groups of strongly overlapping peaks. The algorithm generates peak lists with precise chemical shift and integral intensities, and a reliability measure for the recognition of each peak. The results of automated peak picking of NOESY spectra with AUTOPSY were tested in combination with the combined automated NOESY cross peak assignment and structure calculation routine NOAH implemented in the program DYANA. The quality of the resulting structures was found to be comparable with those from corresponding data obtained with manual peak picking.

  9. Theoretical study of NMR, infrared and Raman spectra on triple-decker phthalocyanines

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Atsushi; Oku, Takeo [Department of Materials Science, The University of Shiga Prefecture 2500 Hassaka, Hikone, Shiga, 522-8533 (Japan)

    2016-02-01

    Electronic structures and magnetic properties of multi-decker phthalocyanines were studied by theoretical calculation. Electronic structures, excited processes at multi-states, isotropic chemical shifts of {sup 13}C, {sup 14}N and {sup 1}H-nuclear magnetic resonance (NMR), principle V-tensor in electronic field gradient (EFG) tensor and asymmetry parameters (η), vibration mode in infrared (IR) and Raman spectra of triple-decker phthalocyanines were calculated by density functional theory (DFT) and time-dependent DFT using B3LYP as basis function. Electron density distribution was delocalized on the phthalocyanine rings with electron static potential. Considerable separation of chemical shifts in {sup 13}C, {sup 14}N and {sup 1}H-NMR was originated from nuclear spin interaction between nitrogen and carbon atoms, nuclear quadrupole interaction based on EFG and η of central metal under crystal field. Calculated optical absorption at multi-excited process was derived from overlapping π-orbital on the phthalocyanine rings. The vibration modes in IR and Raman spectra were based on in-plane deformation and stretching vibrations of metal-ligand coordination bond on the deformed structure.

  10. Deconvolution of Complex 1D NMR Spectra Using Objective Model Selection.

    Directory of Open Access Journals (Sweden)

    Travis S Hughes

    Full Text Available Fluorine (19F NMR has emerged as a useful tool for characterization of slow dynamics in 19F-labeled proteins. One-dimensional (1D 19F NMR spectra of proteins can be broad, irregular and complex, due to exchange of probe nuclei between distinct electrostatic environments; and therefore cannot be deconvoluted and analyzed in an objective way using currently available software. We have developed a Python-based deconvolution program, decon1d, which uses Bayesian information criteria (BIC to objectively determine which model (number of peaks would most likely produce the experimentally obtained data. The method also allows for fitting of intermediate exchange spectra, which is not supported by current software in the absence of a specific kinetic model. In current methods, determination of the deconvolution model best supported by the data is done manually through comparison of residual error values, which can be time consuming and requires model selection by the user. In contrast, the BIC method used by decond1d provides a quantitative method for model comparison that penalizes for model complexity helping to prevent over-fitting of the data and allows identification of the most parsimonious model. The decon1d program is freely available as a downloadable Python script at the project website (https://github.com/hughests/decon1d/.

  11. Partial least squares modeling of combined infrared, 1H NMR and 13C NMR spectra to predict long residue properties of crude oils

    NARCIS (Netherlands)

    de Peinder, P.; Visser, T.; Petrauskas, D.D.; Salvatori, F.; Soulimani, F.; Weckhuysen, B.M.

    2009-01-01

    Research has been carried out to determine the potential of partial least squares (PLS) modeling of mid-infrared (IR) spectra of crude oils combined with the corresponding 1H and 13C nuclear magnetic resonance (NMR) data, to predict the long residue (LR) properties of these substances. The study

  12. Measurement and calculation of characteristic prompt gamma ray spectra emitted during proton irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Polf, J C; Peterson, S; Beddar, S [M D Anderson Cancer Center, Univeristy of Texas, Houston, TX 77030 (United States); McCleskey, M; Roeder, B T; Spiridon, A; Trache, L [Cyclotron Institute, Texas A and M University, College Station, TX 77843 (United States)], E-mail: jcpolf@mdanderson.org

    2009-11-21

    In this paper, we present results of initial measurements and calculations of prompt gamma ray spectra (produced by proton-nucleus interactions) emitted from tissue equivalent phantoms during irradiations with proton beams. Measurements of prompt gamma ray spectra were made using a high-purity germanium detector shielded either with lead (passive shielding), or a Compton suppression system (active shielding). Calculations of the spectra were performed using a model of both the passive and active shielding experimental setups developed using the Geant4 Monte Carlo toolkit. From the measured spectra it was shown that it is possible to distinguish the characteristic emission lines from the major elemental constituent atoms (C, O, Ca) in the irradiated phantoms during delivery of proton doses similar to those delivered during patient treatment. Also, the Monte Carlo spectra were found to be in very good agreement with the measured spectra providing an initial validation of our model for use in further studies of prompt gamma ray emission during proton therapy. (note)

  13. Solvent-dependent deuterium isotope effects in the 15N NMR spectra of an ammonium ion

    International Nuclear Information System (INIS)

    Wielogorska, E.; Jackowski, K.

    2000-01-01

    Deuterium isotope effects on 15 N NMR chemical shifts and spin-spin coupling constants have been investigated for the 15 N enriched ammonium chloride (conc. 15 NH 4 + ion has been observed in water, methanol, ethanol and dimethylsulfoxide, while the 15 ND 4 + has been monitored in the analogous deuterated liquids. It is shown that the isotope effect in nitrogen chemical shifts ( 1 Δ 15 N( 2/1 H)), significantly different in various solvents, changes from -1.392 ppm in dimethylsulfoxide to -0.071 ppm in ethanol. The 1 J(N,H) and 1 J(N,D) coupling constants have been measured for acidic solutions under conditions of slow proton (or deuterium) exchange. The reduced coupling constants have been estimated to present isotope effects in the spin-spin coupling constants. The latter isotope effects are fairly small. (author)

  14. Use of acetimidation in the NMR identification of neurophysin lysine protons

    International Nuclear Information System (INIS)

    Sardana, V.; Breslow, E.

    1986-01-01

    Acetimidation of the two lysine residues of neurophysin (NP) results in localized changes in the proton magnetic resonance spectrum, allowing identification of lysine side-chain resonances. Neither peptide-binding nor protein self-association appeared to be significantly altered by acetimidation. Additionally, no significant effect of either peptide-binding or self-association on lysine epsilon-CH 2 protons was seen. However, dimerization-induced NMR changes in the 1.6-1.8 ppm region, associated with lysine β,γ,σ protons, were altered in the acetimidated protein. In particular, while the spectrum of the acetimidated NP monomer was almost identical to that of the native protein, a shoulder at 1.72 ppm in the native protein dimer was shifted upfield in the modified dimer. Additionally the direction of NMR shifts in the 1.6-1.8 ppm region normally associated with peptide binding to the NP dimer appeared to be reversed in the acetimidated protein. Binding-induced and dimerization-induced changes in all other regions of the spectrum were identical in the native and modified proteins. These results suggest that one or both NP lysine residues may be near the dimer subunit interface and indicate an effect of peptide-binding on lysine side-chain environment

  15. Database proton NMR chemical shifts for RNA signal assignment and validation

    Energy Technology Data Exchange (ETDEWEB)

    Barton, Shawn; Heng Xiao [University of Maryland, Baltimore County, Howard Hughes Medical Institute (United States); Johnson, Bruce A., E-mail: bruce@onemoonscientific.com [University of Maryland, Baltimore County, Department of Chemistry and Biochemistry (United States); Summers, Michael F., E-mail: summers@hhmi.umbc.edu [University of Maryland, Baltimore County, Howard Hughes Medical Institute (United States)

    2013-01-15

    The Biological Magnetic Resonance Data Bank contains NMR chemical shift depositions for 132 RNAs and RNA-containing complexes. We have analyzed the {sup 1}H NMR chemical shifts reported for non-exchangeable protons of residues that reside within A-form helical regions of these RNAs. The analysis focused on the central base pair within a stretch of three adjacent base pairs (BP triplets), and included both Watson-Crick (WC; G:C, A:U) and G:U wobble pairs. Chemical shift values were included for all 4{sup 3} possible WC-BP triplets, as well as 137 additional triplets that contain one or more G:U wobbles. Sequence-dependent chemical shift correlations were identified, including correlations involving terminating base pairs within the triplets and canonical and non-canonical structures adjacent to the BP triplets (i.e. bulges, loops, WC and non-WC BPs), despite the fact that the NMR data were obtained under different conditions of pH, buffer, ionic strength, and temperature. A computer program (RNAShifts) was developed that enables convenient comparison of RNA {sup 1}H NMR assignments with database predictions, which should facilitate future signal assignment/validation efforts and enable rapid identification of non-canonical RNA structures and RNA-ligand/protein interaction sites.

  16. Yeast-expressed human membrane protein aquaporin-1 yields excellent resolution of solid-state MAS NMR spectra

    International Nuclear Information System (INIS)

    Emami, Sanaz; Fan Ying; Munro, Rachel; Ladizhansky, Vladimir; Brown, Leonid S.

    2013-01-01

    One of the biggest challenges in solid-state NMR studies of membrane proteins is to obtain a homogeneous natively folded sample giving high spectral resolution sufficient for structural studies. Eukaryotic membrane proteins are especially difficult and expensive targets in this respect. Methylotrophic yeast Pichia pastoris is a reliable producer of eukaryotic membrane proteins for crystallography and a promising economical source of isotopically labeled proteins for NMR. We show that eukaryotic membrane protein human aquaporin 1 can be doubly ( 13 C/ 15 N) isotopically labeled in this system and functionally reconstituted into phospholipids, giving excellent resolution of solid-state magic angle spinning NMR spectra.

  17. Channeling effect in electronic spectra produced by grazing impact of fast protons on insulator surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Archubi, C D; Gravielle, M S, E-mail: archubi@iafe.uba.a, E-mail: msilvia@iafe.uba.a [Instituto de Astronomia y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, 1428, Buenos Aires (Argentina)

    2009-11-01

    Electron emission due to grazing scattering of fast protons from LiF and KCl surfaces is studied under axial incidence conditions. The differential emission probability is calculated within a distorted-wave formalism, taking into account axial channeled trajectories. For different emission angles, electronic spectra for proton incidence along the two principal crystal axes ([100] and [110]) are compared with those corresponding to an impact velocity in a random direction, finding effects associated with the channeling conditions.

  18. Proceedings of the symposium on measurements of neutron energy spectra using recoil proton proportional counters

    International Nuclear Information System (INIS)

    Urabe, Itsumasa

    1986-01-01

    This is a report of the symposium on measurements of neutron energy spectra using recoil proton proportional counters held at the Research Reactor Institute of Kyoto University on January 27 in 1986. An energy resolution, wall effects of response functions, n · γ discrimination methods and other fundamental properties of recoil proton counters are discussed for a new development of an application of this counter. (author)

  19. Towards high resolution ^1H NMR spectra of tannin colloidal aggregates

    Science.gov (United States)

    Mirabel, M.; Glories, Y.; Pianet, I.; Dufourc, E. J.

    1999-10-01

    The time dependent colloidal formation of tannins in hydro-alcoholic medium has been studied by 1H-NMR. Line broadening observed with time can be cancelled by making use of magic angle sample spinning (MASS) thus yielding sharp lines that allow structural studies. We used as an example catechin, a constitutive monomer of Bordeaux young red wine tannins. Chemical shift variations of polyphenol protons allow monitoring the time course of aggregation. La formation de tanins colloïdaux au cours du temps, en milieu hydroalcoolique, a été suivie par RMN-^1H. Un élargissement marqué des résonances est observé et peut être supprimé par la rotation de l'échantillon à l'angle magique ce qui ouvre tout un champ d'études structurales sur ces composés colloïdaux. L'exemple proposé est celui de la catéchine, monomère constitutif de tannins présents en grande quantité dans les vins rouges jeunes de Bordeaux. Des variations du déplacement chimique de certains protons polyphénoliques permettent de suivre l'évolution temporelle de l'agrégation.

  20. Proton spectra from ultraintense laser-plasma interaction with thin foils: Experiments, theory, and simulation

    International Nuclear Information System (INIS)

    Allen, M.; Sentoku, Y.; Audebert, P.; Fuchs, J.; Gauthier, J.C.; Blazevic, A.; Geissel, M.; Roth, M.; Cowan, T.; Hegelich, M.; Karsch, S.; Morse, E.; Patel, P.K.

    2003-01-01

    A beam of high energy ions and protons is observed from targets irradiated with intensities up to 5x10 19 W/cm 2 . Maximum proton energy is shown to strongly correlate with laser-irradiance on target. Energy spectra from a magnetic spectrometer show a plateau region near the maximum energy cutoff and modulations in the spectrum at approximately 65% of the cutoff energy. Presented two-dimensional particle-in-cell simulations suggest that modulations in the proton spectrum are caused by the presence of multiple heavy-ion species in the expanding plasma

  1. C-13 NMR spectra of all-trans-N-retinylidene-n-butylamine as an analogue of the Schiff base linkage compound in visual pigment

    Energy Technology Data Exchange (ETDEWEB)

    Tokito, Y; Inoue, Y; Chujo, R [Tokyo Inst. of Tech. (Japan). Faculty of Science; Miyoshi, Y

    1975-01-01

    In the process of visual excitation, a visual pigment, rhodopsin, plays a role of a photoreceptor, and it has been known that the first step in the process is the photoisomerization of the rhodopsin visual chromophore. The bathochromic shift has been regarded as the result of the formation of Schiff base linkage of retinal with opsin. In this study, C-13 NMR spectra were obtained for the analogue of the compound with Schiff base linkage in the visual pigment, and the chemical shift change for going from all trans-retinal to all trans-N-retinylidene-n-butylamine (NRB) was discussed. Further, the effect of N protonation in NRB was examined as the reflection of the function of visual pigment. The compound with Schiff base linkage of all trans-retinal with n-butylamine, namely NRB, was used. The nuclear magnetic resonance (NMR) spectra of carbon-13 Fourier transformation were obtained for this sample at natural abundance with a JNM PS-100 spectrometer. In the C-13 FT NMR spectrum of NRB, besides eight peaks in the C-13 NMR of all trans-retinal, four peaks were observed in higher field region. They originated from the portion of n-butylamine in the compound with Schiff base linkage. The peaks in lower field region were assigned to eleven conjugated polyene carbons by the measurement of spin-lattice relaxation time and shift. The chemical shift change for going from retinal to NRB is shown. It is concluded that the ..pi..-electrons in polyene chains are considerably delocalized by the collapse of bond alteration in the retinal forming Schiff base linkage.

  2. A hysteresis phenomenon in NMR spectra of molecular nanomagnets Fe8: a resonant quantum tunneling system

    Science.gov (United States)

    Yamasaki, Tomoaki; Ueda, Miki; Maegawa, Satoru

    2003-05-01

    A molecular nanomagnet Fe8 with a total spin S=10 in the ground state attracts much attention as a substance which exhibits the quantum tunneling of magnetization below 300 mK. We performed 1H NMR measurements for a single crystal of Fe8 in temperature range between 20 and 800 mK. The spectra below 300 mK strongly depend on the sequence of the applied field and those in the positive and negative fields are not symmetric about zero field, while they are symmetric above 300 mK. We discuss the origin of this hysteresis phenomenon, relating to the initial spin state of molecules, the resonant quantum tunneling and the nuclear spin relaxation process.

  3. A hysteresis phenomenon in NMR spectra of molecular nanomagnets Fe8: a resonant quantum tunneling system

    International Nuclear Information System (INIS)

    Yamasaki, Tomoaki; Ueda, Miki; Maegawa, Satoru

    2003-01-01

    A molecular nanomagnet Fe8 with a total spin S=10 in the ground state attracts much attention as a substance which exhibits the quantum tunneling of magnetization below 300 mK. We performed 1 H NMR measurements for a single crystal of Fe8 in temperature range between 20 and 800 mK. The spectra below 300 mK strongly depend on the sequence of the applied field and those in the positive and negative fields are not symmetric about zero field, while they are symmetric above 300 mK. We discuss the origin of this hysteresis phenomenon, relating to the initial spin state of molecules, the resonant quantum tunneling and the nuclear spin relaxation process

  4. Fraction of boroxol rings in vitreous boron oxide from a first-principles analysis of Raman and NMR spectra.

    Science.gov (United States)

    Umari, P; Pasquarello, Alfredo

    2005-09-23

    We determine the fraction f of B atoms belonging to boroxol rings in vitreous boron oxide through a first-principles analysis. After generating a model structure of vitreous B2O3 by first-principles molecular dynamics, we address a large set of properties, including the neutron structure factor, the neutron density of vibrational states, the infrared spectra, the Raman spectra, and the 11B NMR spectra, and find overall good agreement with corresponding experimental data. From the analysis of Raman and 11B NMR spectra, we yield consistently for both probes a fraction f of approximately 0.75. This result indicates that the structure of vitreous boron oxide is largely dominated by boroxol rings.

  5. Membrane lipids protected from oxidation by red wine tannins: a proton NMR study.

    Science.gov (United States)

    Furlan, Aurélien L; Jobin, Marie-Lise; Buchoux, Sébastien; Grélard, Axelle; Dufourc, Erick J; Géan, Julie

    2014-12-01

    Dietary polyphenols widespread in vegetables and beverages like red wine and tea have been reported to possess antioxidant properties that could have positive effects on human health. In this study, we propose a new in situ and non-invasive method based on proton liquid-state nuclear magnetic resonance (NMR) to determine the antioxidant efficiency of red wine tannins on a twice-unsaturated phospholipid, 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (DLiPC), embedded in a membrane model. Four tannins were studied: (+)-catechin (C), (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG). The lipid degradation kinetics was determined by measuring the loss of the bis-allylic protons during oxidation induced by a radical initiator, 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH). The antioxidant efficiency, i.e. the ability of tannins to slow down the lipid oxidation rate, was shown to be higher for galloylated tannins, ECG and EGCG. Furthermore, the mixture of four tannins was more efficient than the most effective tannin, EGCG, demonstrating a synergistic effect. To better understand the antioxidant action mechanism of polyphenols on lipid membranes, the tannin location was investigated by NMR and molecular dynamics. A correlation between antioxidant action of tannins and their location at the membrane interface (inserted at the glycerol backbone level) could thus be established. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  6. NMR

    International Nuclear Information System (INIS)

    Kneeland, J.B.; Lee, B.C.P.; Whalen, J.P.; Knowles, R.J.R.; Cahill, P.T.

    1984-01-01

    Although still quite new, NMR imaging has already emerged as a safe, noninvasive, painless, and effective diagnostic modality requiring no ionizing radiation. Also, NMR appears already to have established itself as the method of choice for the examination of the brain spinal cord (excluding herniated disks). Another area in which NMR excels is in the examination of the pelvis. The use of surface coils offers the promise of visualizing structures with resolution unobtainable by any other means. In addition, NMR, with its superb visualization of vascular structures and potential ability to measure flow, may soon revolutionize the diagnosis of cardiovascular disease. Finally, NMR, through biochemically and physiologically based T/sub 1/ and T/sub 2/ indices or through spectroscopy, may provide a means of monitoring therapeutic response so as to permit tailoring of treatment to the individual patient. In short, NMR is today probably at the same stage as the x-ray was in Roentgen's day

  7. Measurements of LET Spectra of the JINR Phasotron Radiotherapy Proton Beam

    Czech Academy of Sciences Publication Activity Database

    Kubančák, Ján; Molokanov, A. G.

    2013-01-01

    Roč. 2013, č. 6 (2013), s. 90-92 ISSN 1562-6016 R&D Projects: GA MŠk LA08002 Institutional support: RVO:61389005 Keywords : LET spectra * proton beam Subject RIV: BO - Biophysics Impact factor: 0.102, year: 2013 http:// vant .kipt.kharkov.ua/ARTICLE/ VANT _2013_6/article_2013_6_90.pdf

  8. The TeV-scale cosmic ray proton and helium spectra

    Indian Academy of Sciences (India)

    2016-01-07

    Jan 7, 2016 ... Recent measurements of cosmic ray proton and helium spectra show a hardening above a few hundreds of GeV. This excess is hard to understand in the framework of the conventional models of galactic cosmic ray production and propagation. Here, we propose to explain this anomaly by the presence of ...

  9. Event patterns extracted from top quark-related spectra in proton-proton collisions at 8 TeV

    Science.gov (United States)

    Chen, Ya-Hui; Liu, Fu-Hu; Lacey, Roy A.

    2018-02-01

    We analyze the transverse momentum (p T) and rapidity (y) spectra of top quark pairs, hadronic top quarks, and top quarks produced in proton-proton (pp) collisions at center-of-mass energy \\sqrt{s}=8 TeV. For {p}{{T}} spectra, we use the superposition of the inverse power-law suggested by the QCD (quantum chromodynamics) calculus and the Erlang distribution resulting from a multisource thermal model. For y spectra, we use the two-component Gaussian function resulting from the revised Landau hydrodynamic model. The modelling results are in agreement with the experimental data measured at the detector level, in the fiducial phase-space, and in the full phase-space by the ATLAS Collaboration at the Large Hadron Collider (LHC). Based on the parameter values extracted from p T and y spectra, the event patterns in three-dimensional velocity (βx -βy -βz ), momentum (px -py -pz ), and rapidity (y 1-y 2-y) spaces are obtained, and the probability distributions of these components are also obtained. Supported by National Natural Science Foundation of China (11575103, 11747319), the Shanxi Provincial Natural Science Foundation (201701D121005), the Fund for Shanxi “1331 Project” Key Subjects Construction and the US DOE (DE-FG02-87ER40331.A008)

  10. Peak picking multidimensional NMR spectra with the contour geometry based algorithm CYPICK

    International Nuclear Information System (INIS)

    Würz, Julia M.; Güntert, Peter

    2017-01-01

    The automated identification of signals in multidimensional NMR spectra is a challenging task, complicated by signal overlap, noise, and spectral artifacts, for which no universally accepted method is available. Here, we present a new peak picking algorithm, CYPICK, that follows, as far as possible, the manual approach taken by a spectroscopist who analyzes peak patterns in contour plots of the spectrum, but is fully automated. Human visual inspection is replaced by the evaluation of geometric criteria applied to contour lines, such as local extremality, approximate circularity (after appropriate scaling of the spectrum axes), and convexity. The performance of CYPICK was evaluated for a variety of spectra from different proteins by systematic comparison with peak lists obtained by other, manual or automated, peak picking methods, as well as by analyzing the results of automated chemical shift assignment and structure calculation based on input peak lists from CYPICK. The results show that CYPICK yielded peak lists that compare in most cases favorably to those obtained by other automated peak pickers with respect to the criteria of finding a maximal number of real signals, a minimal number of artifact peaks, and maximal correctness of the chemical shift assignments and the three-dimensional structure obtained by fully automated assignment and structure calculation.

  11. Spatially localized 1H NMR spectra of metabolites in the human brain

    International Nuclear Information System (INIS)

    Hanstock, C.C.; Rothman, D.L.; Jue, T.; Shulman, R.G.; Prichard, J.W.

    1988-01-01

    Using a surface coil, the authors have obtained 1 H NMR spectra from metabolites in the human brain. Localization was achieved by combining depth pulses with image-selected in vivo spectroscopy magnetic field gradient methods. 1 H spectra in which total creatine (3.03 ppm) has a signal/noise ratio of 95:1 were obtained in 4 min from 14 ml of brain. A resonance at 2.02 ppm consisting predominantly of N-acetylaspartate was measured relative to the creatine peak in gray and white matter, and the ratio was lower in the white matter. The spin-spin relaxation times of N-acetylaspartate and creatine were measured in white and gray matter and while creatine relaxation times were the same in both, the N-acetylaspartate relaxation time was longer in white matter. Lactate was detected in the normoxic brain and the average of three measurements was ∼0.5 mM from comparison with the creatine plus phosphocreatine peak, which was assumed to be 10.5 mM

  12. Peak picking multidimensional NMR spectra with the contour geometry based algorithm CYPICK

    Energy Technology Data Exchange (ETDEWEB)

    Würz, Julia M.; Güntert, Peter, E-mail: guentert@em.uni-frankfurt.de [Goethe University Frankfurt am Main, Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance (Germany)

    2017-01-15

    The automated identification of signals in multidimensional NMR spectra is a challenging task, complicated by signal overlap, noise, and spectral artifacts, for which no universally accepted method is available. Here, we present a new peak picking algorithm, CYPICK, that follows, as far as possible, the manual approach taken by a spectroscopist who analyzes peak patterns in contour plots of the spectrum, but is fully automated. Human visual inspection is replaced by the evaluation of geometric criteria applied to contour lines, such as local extremality, approximate circularity (after appropriate scaling of the spectrum axes), and convexity. The performance of CYPICK was evaluated for a variety of spectra from different proteins by systematic comparison with peak lists obtained by other, manual or automated, peak picking methods, as well as by analyzing the results of automated chemical shift assignment and structure calculation based on input peak lists from CYPICK. The results show that CYPICK yielded peak lists that compare in most cases favorably to those obtained by other automated peak pickers with respect to the criteria of finding a maximal number of real signals, a minimal number of artifact peaks, and maximal correctness of the chemical shift assignments and the three-dimensional structure obtained by fully automated assignment and structure calculation.

  13. A systematic approach to obtain validated Partial Least Square models for predicting lipoprotein subclasses from serum NMR spectra

    NARCIS (Netherlands)

    Mihaleva, V.V.; van Schalkwijk, D.B.; de Graaf, A.A.; van Duynhoven, J.; van Dorsten, F.A.; Vervoort, J.; Smilde, A.; Westerhuis, J.A.; Jacobs, D.M.

    2014-01-01

    A systematic approach is described for building validated PLS models that predict cholesterol and triglyceride concentrations in lipoprotein subclasses in fasting serum from a normolipidemic, healthy population. The PLS models were built on diffusion-edited 1H NMR spectra and calibrated on

  14. A systematic approach to obtain validated partial least square models for predicting lipoprotein subclasses from serum NMR spectra

    NARCIS (Netherlands)

    Mihaleva, V.V.; Schalkwijk, van D.B.; Graaf, de A.A.; Duynhoven, van J.P.M.; Dorsten, van F.A.; Vervoort, J.J.M.; Smilde, A.K.; Westerhuis, J.A.; Jacobs, D.M.

    2014-01-01

    A systematic approach is described for building validated PLS models that predict cholesterol and triglyceride concentrations in lipoprotein subclasses in fasting serum from a normolipidemic, healthy population. The PLS models were built on diffusion-edited (1)H NMR spectra and calibrated on

  15. A systematic approach to obtain validated partial least square models for predicting lipoprotein subclasses from serum nmr spectra

    NARCIS (Netherlands)

    Mihaleva, V.V.; Schalkwijk, D.B. van; Graaf, A.A. de; Duynhoven, J. van; Dorsten, F.A. van; Vervoort, J.; Smilde, A.; Westerhuis, J.A.; Jacobs, D.M.

    2014-01-01

    A systematic approach is described for building validated PLS models that predict cholesterol and triglyceride concentrations in lipoprotein subclasses in fasting serum from a normolipidemic, healthy population. The PLS models were built on diffusion-edited 1H NMR spectra and calibrated on

  16. MetaboID: a graphical user interface package for assignment of 1H NMR spectra of bodyfluids and tissues.

    Science.gov (United States)

    MacKinnon, Neil; Somashekar, Bagganahalli S; Tripathi, Pratima; Ge, Wencheng; Rajendiran, Thekkelnaycke M; Chinnaiyan, Arul M; Ramamoorthy, Ayyalusamy

    2013-01-01

    Nuclear magnetic resonance based measurements of small molecule mixtures continues to be confronted with the challenge of spectral assignment. While multi-dimensional experiments are capable of addressing this challenge, the imposed time constraint becomes prohibitive, particularly with the large sample sets commonly encountered in metabolomic studies. Thus, one-dimensional spectral assignment is routinely performed, guided by two-dimensional experiments on a selected sample subset; however, a publicly available graphical interface for aiding in this process is currently unavailable. We have collected spectral information for 360 unique compounds from publicly available databases including chemical shift lists and authentic full resolution spectra, supplemented with spectral information for 25 compounds collected in-house at a proton NMR frequency of 900 MHz. This library serves as the basis for MetaboID, a Matlab-based user interface designed to aid in the one-dimensional spectral assignment process. The tools of MetaboID were built to guide resonance assignment in order of increasing confidence, starting from cursory compound searches based on chemical shift positions to analysis of authentic spike experiments. Together, these tools streamline the often repetitive task of spectral assignment. The overarching goal of the integrated toolbox of MetaboID is to centralize the one dimensional spectral assignment process, from providing access to large chemical shift libraries to providing a straightforward, intuitive means of spectral comparison. Such a toolbox is expected to be attractive to both experienced and new metabolomic researchers as well as general complex mixture analysts. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Proton energy spectra during ground level enhancements as measured by EPHIN aboard SOHO

    Energy Technology Data Exchange (ETDEWEB)

    Heber, Bernd; Kuehl, Patrick; Klassen, Andreas; Dresing, Nina [Christian-Albrechts-Universitaet zu Kiel, 24118 Kiel (Germany); Gomez-Herrero, Raul [Universidad de Alcala (Spain)

    2016-07-01

    Ground Level Enhancements (GLEs) are solar energetic particle (SEP) events that are recorded by ground-based instrumentation. The energy of the particles is so high that they produce secondary particles in the Earth's atmosphere, i.e. protons and neutrons, which are detected as sudden increases in cosmic ray intensities measured by e.g. neutron monitors. Since the launch of SOHO in December 1995 the neutron monitor network recorded 16 GLEs. The Electron Proton Helium INstrument on board SOHO has been designed to measure protons and helium up to 53 MeV/nucleon as well as electrons up to 8.3 MeV. Above these energies, particles penetrate all detector elements and thus, a separation between different particle species becomes more complicated. Recently we developed a method that allows deriving the energy spectrum for penetrating protons up to more than 1 GeV. In this contribution we present the proton energy spectra and time profiles of above mentioned GLEs and compare them to previous measurements. Although there are differences of up to a factor two the overall shape of the energy spectra agree surprisingly well. Thus it has been demonstrated that EPHIN measurements are a valuable tool for understanding GLE.

  18. 1H NMR spectra. Part 30(+): 1H chemical shifts in amides and the magnetic anisotropy, electric field and steric effects of the amide group.

    Science.gov (United States)

    Abraham, Raymond J; Griffiths, Lee; Perez, Manuel

    2013-03-01

    The (1)H spectra of 37 amides in CDCl(3) solvent were analysed and the chemical shifts obtained. The molecular geometries and conformational analysis of these amides were considered in detail. The NMR spectral assignments are of interest, e.g. the assignments of the formamide NH(2) protons reverse in going from CDCl(3) to more polar solvents. The substituent chemical shifts of the amide group in both aliphatic and aromatic amides were analysed using an approach based on neural network data for near (≤3 bonds removed) protons and the electric field, magnetic anisotropy, steric and for aromatic systems π effects of the amide group for more distant protons. The electric field is calculated from the partial atomic charges on the N.C═O atoms of the amide group. The magnetic anisotropy of the carbonyl group was reproduced with the asymmetric magnetic anisotropy acting at the midpoint of the carbonyl bond. The values of the anisotropies Δχ(parl) and Δχ(perp) were for the aliphatic amides 10.53 and -23.67 (×10(-6) Å(3)/molecule) and for the aromatic amides 2.12 and -10.43 (×10(-6) Å(3)/molecule). The nitrogen anisotropy was 7.62 (×10(-6) Å(3)/molecule). These values are compared with previous literature values. The (1)H chemical shifts were calculated from the semi-empirical approach and also by gauge-independent atomic orbital calculations with the density functional theory method and B3LYP/6-31G(++) (d,p) basis set. The semi-empirical approach gave good agreement with root mean square error of 0.081 ppm for the data set of 280 entries. The gauge-independent atomic orbital approach was generally acceptable, but significant errors (ca. 1 ppm) were found for the NH and CHO protons and also for some other protons. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Reaction pathways of proton transfer in hydrogen-bonded phenol-carboxylate complexes explored by combined UV-vis and NMR spectroscopy.

    Science.gov (United States)

    Koeppe, Benjamin; Tolstoy, Peter M; Limbach, Hans-Heinrich

    2011-05-25

    Combined low-temperature NMR/UV-vis spectroscopy (UVNMR), where optical and NMR spectra are measured in the NMR spectrometer under the same conditions, has been set up and applied to the study of H-bonded anions A··H··X(-) (AH = 1-(13)C-2-chloro-4-nitrophenol, X(-) = 15 carboxylic acid anions, 5 phenolates, Cl(-), Br(-), I(-), and BF(4)(-)). In this series, H is shifted from A to X, modeling the proton-transfer pathway. The (1)H and (13)C chemical shifts and the H/D isotope effects on the latter provide information about averaged H-bond geometries. At the same time, red shifts of the π-π* UV-vis absorption bands are observed which correlate with the averaged H-bond geometries. However, on the UV-vis time scale, different tautomeric states and solvent configurations are in slow exchange. The combined data sets indicate that the proton transfer starts with a H-bond compression and a displacement of the proton toward the H-bond center, involving single-well configurations A-H···X(-). In the strong H-bond regime, coexisting tautomers A··H···X(-) and A(-)···H··X are observed by UV. Their geometries and statistical weights change continuously when the basicity of X(-) is increased. Finally, again a series of single-well structures of the type A(-)···H-X is observed. Interestingly, the UV-vis absorption bands are broadened inhomogeneously because of a distribution of H-bond geometries arising from different solvent configurations.

  20. 1H NMR spectra dataset and solid-state NMR data of cowpea (Vigna unguiculata)

    DEFF Research Database (Denmark)

    Alves Filho, Elenilson G.; Silva, Lorena M. A.; Teofilo, Elizita M.

    2017-01-01

    In this article the NMR data from chemical shifts, coupling constants, and structures of all the characterized compounds were provided, beyond a complementary PCA evaluation for the corresponding manuscript (E.G. Alves Filho, L.M.A. Silva, E.M. Teofilo, F.H. Larsen, E.S. de Brito, 2017) [3]. In a...

  1. NMR Study of Solvation Effect on Geometry of Proton-Bound Homodimers of Increasing Size

    KAUST Repository

    Gurinov, Andrei A.; Denisov, Gleb S.; Borissova, Alexandra O.; Goloveshkin, Alexander S.; Greindl, Julian; Limbach, Hans-Heinrich; Shenderovich, Ilya G.

    2017-01-01

    Hydrogen bond geometries in the proton-bound homodimers of quinoline and acridine derivatives in an aprotic polar solution have been experimentally studied using 1H NMR at 120 K. The reported results show that increase of the dielec-tric permittivity of the medium results in contraction of the N…N distance. The degree of contraction depends on the homodimer's size and its substituent-specific solvation features. Neither of these effects can be reproduced using conven-tional implicit solvent models employed in computational studies. In general, the N…N distance in the homodimers of pyridine, quinoline, and acridine derivatives decreases in the sequence gas phase > solid state > polar solvent.

  2. NMR Study of Solvation Effect on Geometry of Proton-Bound Homodimers of Increasing Size

    KAUST Repository

    Gurinov, Andrei A.

    2017-10-24

    Hydrogen bond geometries in the proton-bound homodimers of quinoline and acridine derivatives in an aprotic polar solution have been experimentally studied using 1H NMR at 120 K. The reported results show that increase of the dielec-tric permittivity of the medium results in contraction of the N…N distance. The degree of contraction depends on the homodimer\\'s size and its substituent-specific solvation features. Neither of these effects can be reproduced using conven-tional implicit solvent models employed in computational studies. In general, the N…N distance in the homodimers of pyridine, quinoline, and acridine derivatives decreases in the sequence gas phase > solid state > polar solvent.

  3. Response of melanoma tumor phospholipid metabolism to chloroethyle nitrosourea: a high resolution proton NMR spectroscopy study.

    Science.gov (United States)

    Morvan, Daniel; Demidem, Aïcha; Madelmont, Jean-Claude

    2003-07-01

    Phospholipid metabolism is tightly involved in tumor growth regulation and tumor cell survival. The response of phospholipid metabolism to chloroethyle nitrosourea treatment is investigated in a murine B16 melanoma model. Measurements of phospholipid derivatives are performed on intact tumor tissue samples using one- and two-dimensional proton NMR spectroscopy. During the tumor growth inhibition phase under treatment, tumors overexpress phosphocholine, phosphoethanolamine, glycerophosphocholine and glycerophosphoethanolamine, whereas phosphatidylcholine and phosphatidylethanolamine levels are maintained to control levels. During re-growth, which remained quantitatively much below control growth, chloroethyle nitrosourea-treated melanoma tumors overexpress phosphocholine and phosphoethanolamine only. In treated melanoma, phosphatidylcholine levels show an inverse relationship with tumor growth rates. In conclusion, chloroethyle nitrosourea-treated melanoma tumors maintain their phosphatidylcholine levels and exhibit transformed phospholipid metabolism phenotype, by mechanisms that could participate in tumor cell survival.

  4. TU-EF-BRA-01: NMR and Proton Density MRI of the 1D Patient

    International Nuclear Information System (INIS)

    Wolbarst, A.

    2015-01-01

    NMR, and Proton Density MRI of the 1D Patient - Anthony Wolbarst Net Voxel Magnetization, m(x,t). T1-MRI; The MRI Device - Lisa Lemen ‘Classical’ NMR; FID Imaging in 1D via k-Space - Nathan Yanasak Spin-Echo; S-E/Spin Warp in a 2D Slice - Ronald Price Magnetic resonance imaging not only reveals the structural, anatomic details of the body, as does CT, but also it can provide information on the physiological status and pathologies of its tissues, like nuclear medicine. It can display high-quality slice and 3D images of organs and vessels viewed from any perspective, with resolution better than 1 mm. MRI is perhaps most extraordinary and notable for the plethora of ways in which it can create unique forms of image contrast, reflective of fundamentally different biophysical phenomena. As with ultrasound, there is no risk from ionizing radiation to the patient or staff, since no X-rays or radioactive nuclei are involved. Instead, MRI harnesses magnetic fields and radio waves to probe the stable nuclei of the ordinary hydrogen atoms (isolated protons) occurring in water and lipid molecules within and around cells. MRI consists, in essence, of creating spatial maps of the electromagnetic environments around these hydrogen nuclei. Spatial variations in the proton milieus can be related to clinical differences in the biochemical and physiological properties and conditions of the associated tissues. Imaging of proton density (PD), and of the tissue proton spin relaxation times known as T1 and T2, all can reveal important clinical information, but they do so with approaches so dissimilar from one another that each is chosen for only certain clinical situations. T1 and T2 in a voxel are determined by different aspects of the rotations and other motions of the water and lipid molecules involved, as constrained by the local biophysical surroundings within and between its cells – and they, in turn, depend on the type of tissue and its state of health. Three other common

  5. TU-EF-BRA-01: NMR and Proton Density MRI of the 1D Patient

    Energy Technology Data Exchange (ETDEWEB)

    Wolbarst, A. [Univ Kentucky (United States)

    2015-06-15

    NMR, and Proton Density MRI of the 1D Patient - Anthony Wolbarst Net Voxel Magnetization, m(x,t). T1-MRI; The MRI Device - Lisa Lemen ‘Classical’ NMR; FID Imaging in 1D via k-Space - Nathan Yanasak Spin-Echo; S-E/Spin Warp in a 2D Slice - Ronald Price Magnetic resonance imaging not only reveals the structural, anatomic details of the body, as does CT, but also it can provide information on the physiological status and pathologies of its tissues, like nuclear medicine. It can display high-quality slice and 3D images of organs and vessels viewed from any perspective, with resolution better than 1 mm. MRI is perhaps most extraordinary and notable for the plethora of ways in which it can create unique forms of image contrast, reflective of fundamentally different biophysical phenomena. As with ultrasound, there is no risk from ionizing radiation to the patient or staff, since no X-rays or radioactive nuclei are involved. Instead, MRI harnesses magnetic fields and radio waves to probe the stable nuclei of the ordinary hydrogen atoms (isolated protons) occurring in water and lipid molecules within and around cells. MRI consists, in essence, of creating spatial maps of the electromagnetic environments around these hydrogen nuclei. Spatial variations in the proton milieus can be related to clinical differences in the biochemical and physiological properties and conditions of the associated tissues. Imaging of proton density (PD), and of the tissue proton spin relaxation times known as T1 and T2, all can reveal important clinical information, but they do so with approaches so dissimilar from one another that each is chosen for only certain clinical situations. T1 and T2 in a voxel are determined by different aspects of the rotations and other motions of the water and lipid molecules involved, as constrained by the local biophysical surroundings within and between its cells – and they, in turn, depend on the type of tissue and its state of health. Three other common

  6. Resolution Improvements in in Vivo1H NMR Spectra with Increased Magnetic Field Strength

    Science.gov (United States)

    Gruetter, Rolf; Weisdorf, Sally A.; Rajanayagan, Vasantham; Terpstra, Melissa; Merkle, Hellmut; Truwit, Charles L.; Garwood, Michael; Nyberg, Scott L.; Ugurbil, Kâmil

    1998-11-01

    The measurement of cerebral metabolites using highly homologous localization techniques and similar shimming methods was performed in the human brain at 1.5 and 4 T as well as in the dog and rat brain at 9.4 T. In rat brain, improved resolution was achieved by shimming all first- and second-order shim coils using a fully adiabatic FASTMAP sequence. The spectra showed a clear improvement in spectral resolution for all metabolite resonances with increased field strength. Changes in cerebral glutamine content were clearly observed at 4 T compared to 1.5 T in patients with hepatic encephalopathy. At 9.4 T, glutamine H4 at 2.46 ppm was fully resolved from glutamate H4 at 2.37 ppm, as was the potential resonance from γ-amino-butyric acid at 2.30 ppm and N-acetyl-aspartyl-glutamate at 2.05 ppm. Singlet linewidths were found to be as low as 6 Hz (0.015 ppm) at 9.4 T, indicating a substantial decrease in ppm linewidth with field strength. Furthermore, the methylene peak of creatine was partially resolved from phosphocreatine, indicating a close to 1:1 relationship in gray matter. We conclude that increasing the magnetic field strength increases spectral resolution also for1H NMR, which can lead to more than linear sensitivity gains.

  7. Variations of pH as an additional tool in the analysis of crowded NMR spectra of fucosylated chondroitin sulfates.

    Science.gov (United States)

    Ustyuzhanina, Nadezhda E; Dmitrenok, Andrey S; Bilan, Maria I; Shashkov, Alexander S; Gerbst, Alexey G; Usov, Anatolii I; Nifantiev, Nikolay E

    2016-03-24

    The influence of pH variation on chemical shift values in NMR spectra of fucosylated chondroitin sulfates was studied using polysaccharides isolated from three sea cucumber species Apostichopus japonicus, Actinopyga mauritiana and Cucumaria japonica. The signals of glucuronic acid residues were found to be the most sensitive to pH changes in comparison to the chemical shifts of the sulfated galactosamine and fucosyl units, most of which were altered insignificantly. It was shown that in the presence of imidazole-HCl buffer (pH 7.2) NMR spectra of the polysaccharides from A. japonicus and A. mauritiana were sufficiently resolved, whereas under acidic conditions their (1)H NMR spectra were complicated by overlapping of H-1 signals of GlcA and GalNAc. In the case of polysaccharide from C. japonica bearing 3-O-fucosylated and 3-O-sulfated glucuronic acid residues in the backbone, acidification of the medium led to separation of H-1 signals of GlcA3S and GalNAc. Therefore, the combination of data obtained at different pH values may be useful for interpretation of overcrowded spectra of fucosylated chondroitin sulfates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Nonclassical dynamics of the methyl group in 1,1,1-triphenylethane. Evidence from powder 1H NMR spectra

    KAUST Repository

    Osior, Agnieszka

    2017-03-14

    According to the damped quantum rotation (DQR) theory, hindered rotation of methyl groups, evidenced in nuclear magnetic resonance (NMR) line shapes, is a nonclassical process. It comprises a number of quantum-rate processes measured by two different quantum-rate constants. The classical jump model employing only one rate constant is reproduced if these quantum constants happen to be equal. The values of their ratio, or the nonclassicallity coefficient, determined hitherto from NMR spectra of single crystals and solutions range from about 1.20 to 1.30 in the latter case to above 5.0 in the former, with the value of 1 corresponding to the jump model. Presently, first systematic investigations of the DQR effects in wide-line NMR spectra of a powder sample are reported. For 1,1,1-triphenylethane deuterated in the aromatic positions, the relevant line-shape effects were monitored in the range 99–121 K. The values of the nonclassicality coefficient dropping from 2.7 to 1.7 were evaluated in line shape fits to the experimental powder spectra from the range 99–108 K. At these temperatures, the fits with the conventional line-shape model are visibly inferior to the DQR fits. Using a theoretical model reported earlier, a semiquantitative interpretation of the DQR parameters evaluated from the spectra is given. It is shown that the DQR effects as such can be detected in wide-line NMR spectra of powdered samples, which are relatively facile to measure. However, a fully quantitative picture of these effects can only be obtained from the much more demanding experiments on single crystals.

  9. Inclusive spectra of mesons with large transverse momenta in proton-nuclear collisions at high energies

    International Nuclear Information System (INIS)

    Lykasov, G.I.; Sherkhonov, B.Kh.

    1982-01-01

    Basing on the proposed earlier quark model of hadron-nucleus processes with large transverse momenta psub(perpendicular) the spectra of π +- , K +- meson production with large psub(perpendicular) in proton-nucleus collisions at high energies are calculated. The performed comparison of their dependence of the nucleus-target atomic number A with experimental data shows a good agreement. Theoretical and experimental ratios of inclusive spectra of K +- and π +- mesons in the are compared. Results of calculations show a rather good description of experimental data on large psub(perpendicular) meson production at high energies

  10. Proton continuum spectra from deuteron break-up at 56 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, N.; Kondo, M.; Shimizu, A.; Saito, T.; Nagamachi, S. [Osaka Univ., Suita (Japan). Research Center for Nuclear Physics; Sakaguchi, H.; Ohtani, F.; Goto, A.; Ikegami, H.; Muraoka, M [eds.

    1980-01-01

    Proton continuum spectra from deuteron break-up have been measured for 14 elements at 56 MeV. Each spectrum shows a prominent bump at forward angles. Projectile break-up calculations reproduce well the spectral shapes and the angular dependence of the bump spectra. The break-up cross section is nearly proportional to (A sup(1/3) + 0.8)/sup 2/. The total break-up cross section amounts to 24 - 35% of the deuteron total reaction cross section.

  11. Protein folding kinetics by combined use of rapid mixing techniques and NMR observation of individual amide protons

    International Nuclear Information System (INIS)

    Roder, H.; Wuethrich, K.

    1986-01-01

    A method to be used for experimental studies of protein folding introduced by Schmid and Baldwin, which is based on the competition between amide hydrogen exchange and protein refolding, was extended by using rapid mixing techniques and 1 H NMR to provide site-resolved kinetic information on the early phases of protein structure acquisition. In this method, a protonated solution of the unfolded protein is rapidly mixed with a deuterated buffer solution at conditions assuring protein refolding in the mixture. This simultaneously initiates the exchange of unprotected amide protons with solvent deuterium and the refolding of protein segments which can protect amide groups from further exchange. After variable reaction times the amide proton exchange is quenched while folding to the native form continues to completion. By using 1 H NMR, the extent of exchange at individual amide sites is then measured in the refolded protein. Competition experiments at variable reaction times or variable pH indicate the time at which each amide group is protected in the refolding process. This technique was applied to the basic pancreatic trypsin inhibitor, for which sequence-specific assignments of the amide proton NMR lines had previously been obtained. For eight individual amide protons located in the beta-sheet and the C-terminal alpha-helix of this protein, apparent refolding rates in the range from 15 s-1 to 60 s-1 were observed. These rates are on the time scale of the fast folding phase observed with optical probes

  12. Detection of early gamma-postirradiation effects in murine spleen by proton NMR relaxation times.

    Science.gov (United States)

    Zebrowska, G; Lewa, C J; Ramee, M P; Husson, F; De Certaines, J D

    2001-01-01

    It was our aim to evaluate the potential of proton relaxation times for the early detection of radiation-induced spleen changes. Female Swiss mice were irradiated with doses ranging from 0.05 Gy to 4 Gy. The body weight, the spleen weight and the spleen water content of single animals were determined. Measurements of longitudinal (T1) and transversal (T2) proton relaxation times of the spleen samples were performed in a 0.47 T spectrometer. Histological examinations of the control and irradiated organs were performed. NMR measurements during the first five days after irradiation showed that total body gamma-irradiation with doses from 1.5 Gy to 4 Gy results in decreasing T1 of the murine spleen. Significant shortening in T2 was observed for the spleen of animals irradiated with a dose of 4 Gy. Histological examinations demonstrated subnormal architecture in slices derived from animals irradiated with 2 Gy and 4 Gy. The fluctuations of the spleen T1 and T2 of irradiated mice are correlated with relative spleen weight and can be used to estimate radiation induced changes in this organ.

  13. PMR spectra and proton magnetic relaxation in uranyl nitrate-hexamethylenetetramine-urea-water gel forming system

    International Nuclear Information System (INIS)

    Vashman, A.A.; Pronin, I.S.; Brylkina, T.V.; Makarov, V.M.

    1979-01-01

    PMR spectra and proton relaxation in the nitrate-hexamethylenetetramine (HMTA)-urea-water gelling system are studied. According to PMR spectra products of HMTA chemical decomposition, which are supposed to be formed in the gelling process, have not been detected. Effect of hydrogen exchange upon PMR spectra of urea and water in the presence of HMTA and uranyl nitrate is studied. Periods of spin-lattice and spin-spin relaxations of water and HMTA protons in gels on the base of uranyl nitrate are found. Data on relaxation permitted to make qualitative conclusions upon the gel structure and HMTA molecule distribution over ''phases''. Nonproducibility of the results of period measurements in gels is the result of nonproducibility of the gel structure in the course of transformation of liquid solution into gel. Temperature dependences of proton relaxation in the gels are impossible yet to interpret on the basis of temperature behaviour of one correlation period, controlling dipole-dipole nuclear magnetic relaxation, and obeying Arrhenius dependence on the temperature

  14. The study of NMR relaxation time spectra multi-exponential inversion based on Lloyd–Max optimal quantization

    International Nuclear Information System (INIS)

    Li, Xuewei; Kong, Li; Cheng, Jingjing; Wu, Lei

    2015-01-01

    The multi-exponential inversion of a NMR relaxation signal plays a key role in core analysis and logging interpretation in the formation of porous media. To find an efficient metod of inverting high-resolution relaxation time spectra rapidly, this paper studies the effect of inversion which is based on the discretization of the original echo in a time domain by using a simulation model. This paper analyzes the ill-condition of discrete equations on the basis of the NMR inversion model and method, determines the appropriate number of discrete echoes and acquires the optimal distribution of discrete echo points by the Lloyd–Max optimal quantization method, in considering the inverse precision and computational complexity comprehensively. The result shows that this method can effectively improve the efficiency of the relaxation time spectra inversion while guaranteeing inversed accuracy. (paper)

  15. Amide proton solvent protection in amylin fibrils probed by quenched hydrogen exchange NMR.

    Directory of Open Access Journals (Sweden)

    Andrei T Alexandrescu

    Full Text Available Amylin is an endocrine hormone that accumulates in amyloid plaques in patients with advanced type 2 diabetes. The amyloid plaques have been implicated in the destruction of pancreatic β-cells, which synthesize amylin and insulin. To better characterize the secondary structure of amylin in amyloid fibrils we assigned the NMR spectrum of the unfolded state in 95% DMSO and used a quenched hydrogen-deuterium exchange technique to look at amide proton solvent protection in the fibrils. In this technique, partially exchanged fibrils are dissolved in 95% DMSO and information about amide proton occupancy in the fibrils is determined from DMSO-denatured monomers. Hydrogen exchange lifetimes at pH 7.6 and 37°C vary between ∼5 h for the unstructured N-terminus to 600 h for amide protons in the two β-strands that form inter-molecular hydrogen bonds between amylin monomers along the length of the fibril. Based on the protection data we conclude that residues A8-H18 and I26-Y37 comprise the two β-strands in amylin fibrils. There is variation in protection within the β-strands, particularly for strand β1 where only residues F15-H18 are strongly protected. Differences in protection appear to be due to restrictions on backbone dynamics imposed by the packing of two-layers of C2-symmetry-related β-hairpins in the protofilament structure, with strand β1 positioned on the surface and β2 in the interior.

  16. Isotope-edited proton NMR study on the structure of a pepsin/inhibitor complex

    International Nuclear Information System (INIS)

    Fesik, S.W.; Luly, J.R.; Erickson, J.W.; Abad-Zapatero, C.

    1988-01-01

    A general approach is illustrated for providing detailed structural information on large enzyme/inhibitor complexes using NMR spectroscopy. The method involves the use of isotopically labeled ligands to simplify two-dimensional NOE spectra of large molecular complexes by isotope-editing techniques. With this approach, the backbone and side-chain conformations (at the P 2 and P 3 sites) of a tightly bound inhibitor of porcine pepsin have bene determined. In addition, structural information on the active site of pepsin has been obtained. Due to the sequence homology between porcine pepsin and human renin, this structural information may prove useful for modeling renin/inhibitor complexes with the ultimate goal of designing more effective renin inhibitors. Moreover, this general approach can be applied to study other biological systems of interest such as other enzyme/inhibitor complexes, ligands bound to soluble receptors, and enzyme/substrate interactions

  17. Energetic proton analysis at large angle by 200 MeV proton scattering on nuclei: inclusive spectra; proton-gamma coincidence spectra

    International Nuclear Information System (INIS)

    Al-Zoubidi, M.

    1984-01-01

    With a large acceptance magnet, both in momentum (300-700 MeV/c) and angle (10 0 ), backward energetic proton inclusive cross sections were measured for 200 MeV protons hitting 6 Li, 27 Al, 28 Si, 58 Ni and 197 Au targets. The data are analysed using the ''Quasi Two Body Scaling'' (QTBS) picture and also compared with the predictions at a standard cascade code. This QTBS approch assumes the dominance of the single scattering mechanism. It is shown that a scaling regime is reached for several data taken at incident energies at about 200 MeV/A. These data are remarkably well reproduced using a universal one nucleon momentum density distribution for A > approximately 20. A (p-γ) coincidence experiment was performed on 28 Si target, at 80 0 . Preliminary results indicates also single nucleon-nucleon collision, but the other low energy nucleon interacts with the residuel nucleus. Excitation energy transferred to the system is about 50 MeV [fr

  18. Use of proton-enhanced, natural abundance /sup 13/C NMR to study the molecular dynamics of model and biological membranes

    Energy Technology Data Exchange (ETDEWEB)

    Cornell, B A [Commonwealth Scientific and Industrial Research Organization, North Ryde (Australia). Div. of Food Research; Keniry, M [Sydney Univ. (Australia). Dept. of Physical Chemistry; Hiller, R G [Macquarie Univ., North Ryde (Australia). School of Biological Sciences; Smith, R [La Trobe Univ., Bundoora (Australia). Dept. of Biochemistry

    1980-06-16

    Proton-enhanced NMR of the natural abundance /sup 13/C nuclei is used to study the lipid mobility in dispersions containing cholesterol, the polypeptide gramicidin A, and in membrane proparations derived from spinach chloroplasts and bovine brain myelin.

  19. Hairpin and duplex formation in DNA fragments CCAATTTTGG, CCAATTTTTTGG, and CCATTTTTGG: a proton NMR study

    International Nuclear Information System (INIS)

    Pramanik, P.; Kanhouwa, N.; Kan, L.

    1988-01-01

    Three DNA fragments, CCAATTTTGG (1), CCAATTTTTTGG (2), AND CCATTTTTGG (3), were studied by proton NMR spectroscopy in aqueous solution. All these oligodeoxyribonucleotides contain common sequences at the 5' and 3' ends (5'-CCA and TGG-3'). 2 as well as 3 forms only hairpin structures with four unpaired thymidylyl units, four and three base pair stems, respectively, in neutral solution under low and high NaCl concentrations. At high salt concentration the oligomer 1 forms a duplex structure with -TT- internal loop. On the other hand, the same oligomer forms a stable hairpin structure at low salt and low strand concentrations at pH 7. The hairpin structure of 1 has a stem containing only three base pairs (CCA x TGG) and a loop containing four nucleotides (-ATTT-) that includes a dissociated A x T base pair. The two secondary structures of 1 coexist in an aqueous solution containing 0.1 M NaCl, at pH 7. The equilibrium shifts to the hairpin side when the temperature is raised. The stabilities and base-stacking modes of all three oligonucleotides in tow different structures are reported

  20. Proton recoil spectra in spherical proportional counters calculated with finite element and Monte Carlo methods

    Energy Technology Data Exchange (ETDEWEB)

    Benmosbah, M. [Laboratoire de Chimie Physique et Rayonnement Alain Chambaudet, UMR CEA E4, Universite de Franche-Comte, 16 route de Gray, 25030 Besancon Cedex (France); Groetz, J.E. [Laboratoire de Chimie Physique et Rayonnement Alain Chambaudet, UMR CEA E4, Universite de Franche-Comte, 16 route de Gray, 25030 Besancon Cedex (France)], E-mail: jegroetz@univ-fcomte.fr; Crovisier, P. [Service de Protection contre les Rayonnements, CEA Valduc, 21120 Is/Tille (France); Asselineau, B. [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN, Cadarache BP3, 13115 St Paul-lez-Durance (France); Truffert, H.; Cadiou, A. [AREVA NC, Etablissement de la Hague, DQSSE/PR/E/D, 50444 Beaumont-Hague Cedex (France)

    2008-08-11

    Proton recoil spectra were calculated for various spherical proportional counters using Monte Carlo simulation combined with the finite element method. Electric field lines and strength were calculated by defining an appropriate mesh and solving the Laplace equation with the associated boundary conditions, taking into account the geometry of every counter. Thus, different regions were defined in the counter with various coefficients for the energy deposition in the Monte Carlo transport code MCNPX. Results from the calculations are in good agreement with measurements for three different gas pressures at various neutron energies.

  1. Atmospheric proton and deuterium energy spectra determination with the MASS2 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Grimani, C.; Brunetti, M.T.; Codino, A.; Finetti, N. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); Papini, P.; Massimo Brancaccio, F. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Basini, G.; Bongiorno, F. [INFN, Laboratori Nazionali di Frascati, Rome (Italy); Golden, R.L. [New Mexico State Univ., Las Cruces, NM (United States). Particle Astrophysics Lab.; Hof, M. [Siegen Univ. (Germany). Fachbereich Physik

    1995-09-01

    The energy spectra of atmospheric-secondary protons and deuterium nuclei have been measured during the September 23, 1991, balloon flight of the NMSU/Wizard - MASS2 instrument. The apparatus was launched from Fort Sumner, New Mexico. The geomagnetic cutoff at the launch site is about 4.5 GV/c. The instrument was flown for 9.8 hours at an altitude of over 100,000 feet. Particles detected below the geomagnetic cutoff have been produced mainly by the interactions of the primary cosmic rays with the atmosphere. The measurement of cosmic ray energy spectra below the geomagnetic cutoff provide direct insights into the particle production mechanism and allows comparison to atmospheric cascade calculations.

  2. Evidence for an anisotropic contact shift. Proton NMR study of line shapes in uranocene and (C5H5)3UCl powders

    International Nuclear Information System (INIS)

    McGarvey, B.R.; Nagy, S.

    1987-01-01

    The proton NMR spectra of solid powders of uranocene and (C 5 H 5 ) 3 UCl were measured from 90 to 298 K. The line shapes of both systems became increasingly anisotropic as the temperature was lowered. The cyclooctatetraene rings in uranocene were found to be rotating at a frequency greater than 100 kHz down to 90 K. The (C 5 H 5 ) 3 UCl molecules were found to be reorienting rapidly above 220 K, but below 140 K the NMR spectra were characteristic of a rigid lattice with no rotation of the cyclopentadienyl rings. The spectra of both compounds could be simulated by assuming an axial paramagnetic shift tensor and an orientation-dependent line width. Comparison of the experimental shift tensor with that calculated for a point dipolar interaction revealed a large and very anisotropic paramagnetic shift for uranocene due to unpaired spin transferred into the ligand orbitals. The shift was large when the magnetic field was along the 8-fold symmetry axis of the molecule and nearly zero perpendicular to the axis. It appears conclusive that the contact shift in uranocene is not isotropic at all. A similar anisotropy in the contact shift associated with the cyclopentadienyl rings is evident also in the results for (C 5 H 5 )UCl. The average solid-state shift of uranocene agreed with the solution shift, within experimental error, but the solid state shift of (C 5 H 5 ) 3 UCl was 42 ppm greater than the solution shift at 298 K, indicating a difference in molecular geometry between the crystalline state and solution. 32 references, 8 figures, 3 tables

  3. Resonance assignment of the NMR spectra of disordered proteins using a multi-objective non-dominated sorting genetic algorithm

    International Nuclear Information System (INIS)

    Yang, Yu; Fritzsching, Keith J.; Hong, Mei

    2013-01-01

    A multi-objective genetic algorithm is introduced to predict the assignment of protein solid-state NMR (SSNMR) spectra with partial resonance overlap and missing peaks due to broad linewidths, molecular motion, and low sensitivity. This non-dominated sorting genetic algorithm II (NSGA-II) aims to identify all possible assignments that are consistent with the spectra and to compare the relative merit of these assignments. Our approach is modeled after the recently introduced Monte-Carlo simulated-annealing (MC/SA) protocol, with the key difference that NSGA-II simultaneously optimizes multiple assignment objectives instead of searching for possible assignments based on a single composite score. The multiple objectives include maximizing the number of consistently assigned peaks between multiple spectra (“good connections”), maximizing the number of used peaks, minimizing the number of inconsistently assigned peaks between spectra (“bad connections”), and minimizing the number of assigned peaks that have no matching peaks in the other spectra (“edges”). Using six SSNMR protein chemical shift datasets with varying levels of imperfection that was introduced by peak deletion, random chemical shift changes, and manual peak picking of spectra with moderately broad linewidths, we show that the NSGA-II algorithm produces a large number of valid and good assignments rapidly. For high-quality chemical shift peak lists, NSGA-II and MC/SA perform similarly well. However, when the peak lists contain many missing peaks that are uncorrelated between different spectra and have chemical shift deviations between spectra, the modified NSGA-II produces a larger number of valid solutions than MC/SA, and is more effective at distinguishing good from mediocre assignments by avoiding the hazard of suboptimal weighting factors for the various objectives. These two advantages, namely diversity and better evaluation, lead to a higher probability of predicting the correct

  4. Resonance assignment of the NMR spectra of disordered proteins using a multi-objective non-dominated sorting genetic algorithm.

    Science.gov (United States)

    Yang, Yu; Fritzsching, Keith J; Hong, Mei

    2013-11-01

    A multi-objective genetic algorithm is introduced to predict the assignment of protein solid-state NMR (SSNMR) spectra with partial resonance overlap and missing peaks due to broad linewidths, molecular motion, and low sensitivity. This non-dominated sorting genetic algorithm II (NSGA-II) aims to identify all possible assignments that are consistent with the spectra and to compare the relative merit of these assignments. Our approach is modeled after the recently introduced Monte-Carlo simulated-annealing (MC/SA) protocol, with the key difference that NSGA-II simultaneously optimizes multiple assignment objectives instead of searching for possible assignments based on a single composite score. The multiple objectives include maximizing the number of consistently assigned peaks between multiple spectra ("good connections"), maximizing the number of used peaks, minimizing the number of inconsistently assigned peaks between spectra ("bad connections"), and minimizing the number of assigned peaks that have no matching peaks in the other spectra ("edges"). Using six SSNMR protein chemical shift datasets with varying levels of imperfection that was introduced by peak deletion, random chemical shift changes, and manual peak picking of spectra with moderately broad linewidths, we show that the NSGA-II algorithm produces a large number of valid and good assignments rapidly. For high-quality chemical shift peak lists, NSGA-II and MC/SA perform similarly well. However, when the peak lists contain many missing peaks that are uncorrelated between different spectra and have chemical shift deviations between spectra, the modified NSGA-II produces a larger number of valid solutions than MC/SA, and is more effective at distinguishing good from mediocre assignments by avoiding the hazard of suboptimal weighting factors for the various objectives. These two advantages, namely diversity and better evaluation, lead to a higher probability of predicting the correct assignment for a

  5. Isotopically decoupled vibrational spectra and proton exchange rates for crystalline NH3 and ammonia hydrate

    Science.gov (United States)

    Thornton, Cynthia; Khatkale, M. S.; Devlin, J. Paul

    1981-12-01

    Codeposits of NH3 with ND3 or D2O have been prepared at liquid nitrogen temperatures in the absence of proton exchange. Vibrational data for the anhydrous cubic crystalline ammonia, containing isolated NH3 or ND3, confirm that, relative to water ice, intermolecular coupling in ammonia ice exerts a relatively minor influence on the infrared and Raman spectra. Nevertheless, sizeable decoupling shifts, particularly for ν1, have been observed and attributed to a combination of factors including correlation field and Fermi resonance effects. The Raman polarization data has also affirmed long standing assignments of ν1 and ν3 for ammonia ice. Warming of the ammonia thin films resulted in limited isotopic scrambling at 130 K, apparently possible only through the agency of trace concentrations of water. The vibrational coupling pattern for the resultant NHD2 and NH2D molecules suggest that proton (deuteron) migration away from the exchange centers is impossible at temperatures up to 150 K. By contrast, isotopic scrambling was rapid and complete at 140 K for amorphous ammonia hydrate films (˜35% NH3, ˜65% D2O) which were also prepared without exchange at ˜90 K. The proton (deuteron) exchange rate is much greater for the amorphous ammonia hydrate at 140 K than for pure water ice. Such exchange requires both ion-pair defect formation and proton mobility. Since the NH3 suppresses the H3O+ concentration via formation of NH+4, a suppression the likes of which has been shown to stop proton exchange in water ice, the evidence strongly suggests that NH4+ in ammonia, like H3O+ in water, is an effective proton transfer agent, probably acting through a tunneling mechanism (i.e., H3N+-HṡṡṡNH3→H3NṡṡṡH-N+H3 etc.) to render the proton mobile in the ammonia hydrate. This mobility combined with the greater NH4+ concentration, relative to the H3O+ concentration in H2O ice Ic, results in isotopic scrambling at the reduced temperature.

  6. 1H NMR spectra part 31: 1H chemical shifts of amides in DMSO solvent.

    Science.gov (United States)

    Abraham, Raymond J; Griffiths, Lee; Perez, Manuel

    2014-07-01

    The (1)H chemical shifts of 48 amides in DMSO solvent are assigned and presented. The solvent shifts Δδ (DMSO-CDCl3 ) are large (1-2 ppm) for the NH protons but smaller and negative (-0.1 to -0.2 ppm) for close range protons. A selection of the observed solvent shifts is compared with calculated shifts from the present model and from GIAO calculations. Those for the NH protons agree with both calculations, but other solvent shifts such as Δδ(CHO) are not well reproduced by the GIAO calculations. The (1)H chemical shifts of the amides in DMSO were analysed using a functional approach for near ( ≤ 3 bonds removed) protons and the electric field, magnetic anisotropy and steric effect of the amide group for more distant protons. The chemical shifts of the NH protons of acetanilide and benzamide vary linearly with the π density on the αN and βC atoms, respectively. The C=O anisotropy and steric effect are in general little changed from the values in CDCl3. The effects of substituents F, Cl, Me on the NH proton shifts are reproduced. The electric field coefficient for the protons in DMSO is 90% of that in CDCl3. There is no steric effect of the C=O oxygen on the NH proton in an NH…O=C hydrogen bond. The observed deshielding is due to the electric field effect. The calculated chemical shifts agree well with the observed shifts (RMS error of 0.106 ppm for the data set of 257 entries). Copyright © 2014 John Wiley & Sons, Ltd.

  7. Ground-state magnetization of the molecular cluster Mn12O12-acetate as seen by proton NMR

    International Nuclear Information System (INIS)

    Furukawa, Y.; Watanabe, K.; Kumagai, K.; Jang, Z. H.; Lascialfari, A.; Borsa, F.; Gatteschi, D.

    2000-01-01

    1 H nuclear magnetic resonance (NMR) measurements have been carried out in Mn 12 O 12 -acetate clusters at low temperature in order to investigate microscopically the static and dynamic magnetic properties of the molecule in its high-spin S=10 ground state. Below liquid helium temperature it is found that the local hyperfine fields at the proton sites are static as expected for the very slow superparamagnetic relaxation of Mn 12 O 12 at low temperature. The magnitude and distribution of the hyperfine fields can be reproduced to a good approximation by considering only the dipolar interaction of protons with the local Mn magnetic moments and by assigning the magnitude and orientation of the local moments of the different Mn 3+ and Mn 4+ ions according to an accepted coupling scheme for the total S=10 ground state. The relaxation time of the macroscopic magnetization of the cluster was measured by monitoring the change of the intensity of the 1 H-NMR shifted lines following inversion of the applied magnetic field. This is possible because the sudden change of the field orientation changes the sign of the shift of the NMR lines in the proton spectrum. Although important differences are noticed, the relaxation time of the magnetization as measured indirectly by the 1 H-NMR method is comparable to the one obtained directly with a superconducting quantum interference device magnetometer. In particular we could reproduce the minima in the relaxation time as a function of magnetic field at the fields for level crossing, minima which are considered to be a signature of the quantum tunneling of the magnetization

  8. HiFSA fingerprinting applied to isomers with near-identical NMR spectra: the silybin/isosilybin case.

    Science.gov (United States)

    Napolitano, José G; Lankin, David C; Graf, Tyler N; Friesen, J Brent; Chen, Shao-Nong; McAlpine, James B; Oberlies, Nicholas H; Pauli, Guido F

    2013-04-05

    This study demonstrates how regio- and diastereo-isomers with near-identical NMR spectra can be distinguished and unambiguously assigned using quantum mechanical driven (1)H iterative Full Spin Analysis (HiFSA). The method is illustrated with four natural products, the flavonolignans silybin A, silybin B, isosilybin A, and isosilybin B, which exhibit extremely similar coupling patterns and chemical shift differences well below the commonly reported level of accuracy of 0.01 ppm. The HiFSA approach generated highly reproducible (1)H NMR fingerprints that enable distinction of all four isomers at (1)H frequencies from 300 to 900 MHz. Furthermore, it is demonstrated that the underlying numeric (1)H NMR profiles, combined with iterative computational analysis, allow parallel quantification of all four isomers, even in difficult to characterize reference materials and mixtures. The results shed new light on the historical challenges to the qualitative and quantitative analysis of these therapeutically relevant flavonolignans and open new opportunities to explore hidden diversity in the chemical space of organic molecules.

  9. Two-dimensional 1H and 31P NMR spectra and restrained molecular dynamics structure of an extrahelical adenosine tridecamer oligodeoxyribonucleotide duplex

    International Nuclear Information System (INIS)

    Nikonowicz, E.; Roongta, V.; Jones, C.R.; Gorenstein, D.G.

    1989-01-01

    Assignment of the 1H and 31P NMR spectra of an extrahelical adenosine tridecamer oligodeoxyribonucleotide duplex, d(CGCAGAATTCGCG)2, has been made by two-dimensional 1H-1H and heteronuclear 31P-1H correlated spectroscopy. The downfield 31P resonance previously noted by Patel et al. (1982) has been assigned by both 17O labeling of the phosphate as well as a pure absorption phase constant-time heteronuclear 31P-1H correlated spectrum and has been associated with the phosphate on the 3' side of the extrahelical adenosine. JH3'-P coupling constants for each of the phosphates of the tridecamer were obtained from the 1H-31P J-resolved selective proton-flip 2D spectrum. By use of a modified Karplus relationship the C4-C3'-O3-P torsional angles (epsilon) were obtained. There exists a good linear correlation between 31P chemical shifts and the epsilon torsional angle. The 31P chemical shifts and epsilon torsional angles follow the general observation that the more internal the phosphate is located within the oligonucleotide sequence, the more upfield the 31P resonance occurs. Because the extrahelical adenosine significantly distorts the deoxyribose phosphate backbone conformation even several bases distant from the extrahelical adenosine, 31P chemical shifts show complex site- and sequence-specific variations. Modeling and NOESY distance-restrained energy minimization and restrained molecular dynamics suggest that the extrahelical adenosine stacks into the duplex. However, a minor conformation is also observed in the 1H NMR, which could be associated with a structure in which the extrahelical adenosine loops out into solution

  10. A novel tridentate Schiff base dioxo-molybdenum(VI) complex: synthesis, experimental and theoretical studies on its crystal structure, FTIR, UV-visible, ¹H NMR and ¹³C NMR spectra.

    Science.gov (United States)

    Saheb, Vahid; Sheikhshoaie, Iran; Stoeckli-Evans, Helen

    2012-09-01

    A new dioxo-molybdenum(VI) complex [MoO(2)(L)(H(2)O)] has been synthesized, using 5-methoxy 2-[(2-hydroxypropylimino)methyl]phenol as tridentate ONO donor Schiff base ligand (H(2)L) and MoO(2)(acac)(2). The yellow crystals of the compound are used for single-crystal X-ray analysis and measuring Fourier Transform Infrared (FTIR), UV-visible, (1)H NMR and (13)C NMR spectra. Electronic structure calculations at the B3LYP and PW91PW91 levels of theory are performed to optimize the molecular geometry and to calculate the UV-visible, FTIR, (1)H NMR and (13)C NMR spectra of the compound. Vibrational assignments and analysis of the fundamental modes of the compound are performed. Time-dependent density functional theory (TDDFT) method is used to calculate the electronic transitions of the complex. All theoretical methods can well reproduce the structure of the compound. The (1)H NMR shielding tensors computed at the B3LYP/DGDZVP level of theory is in agreement with experimental (1)H NMR spectra. However, the (13)C NMR shielding tensors computed at the B3LYP level, employing a combined basis set of DGDZVP for Mo and 6-31+G(2df,p) for other atoms, are in better agreement with experimental (13)C NMR spectra. The electronic transitions calculated at the B3LYP/DGDZVP level by using TD-DFT method is in accordance with the observed UV-visible spectrum of the compound. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. A new Schiff base compound N,N'-(2,2-dimetylpropane)-bis(dihydroxylacetophenone): synthesis, experimental and theoretical studies on its crystal structure, FTIR, UV-visible, 1H NMR and 13C NMR spectra.

    Science.gov (United States)

    Saheb, Vahid; Sheikhshoaie, Iran

    2011-10-15

    The Schiff base compound, N,N'-(2,2-dimetylpropane)-bis(dihydroxylacetophenone) (NDHA) is synthesized through the condensation of 2-hydroxylacetophenone and 2,2-dimethyl 1,3-amino propane in methanol at ambient temperature. The yellow crystalline precipitate is used for X-ray single-crystal determination and measuring Fourier transform infrared (FTIR), UV-visible, (1)H NMR and (13)C NMR spectra. Electronic structure calculations at the B3LYP, PBEPBE and PW91PW91 levels of theory are performed to optimize the molecular geometry and to calculate the FTIR, (1)H NMR and (13)C NMR spectra of the compound. Time-dependent density functional theory (TDDFT) method is used to calculate the UV-visible spectrum of NDHA. Vibrational frequencies are determined experimentally and compared with those obtained theoretically. Vibrational assignments and analysis of the fundamental modes of the compound are also performed. All theoretical methods can well reproduce the structure of the compound. The (1)H NMR and (13)C NMR chemical shifts calculated by all DFT methods are consistent with the experimental data. However, the NMR shielding tensors computed at the B3LYP/6-31+G(d,p) level of theory are in better agreement with experimental (1)H NMR and (13)C NMR spectra. The electronic absorption spectrum calculated at the B3LYP/6-31+G(d,p) level by using TD-DFT method is in accordance with the observed UV-visible spectrum of NDHA. In addition, some quantum descriptors of the molecule are calculated and conformational analysis is performed and the results were compared with the crystallographic data. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Changes in mouse brain metabolism following a convulsive dose of soman: A proton HRMAS NMR study

    Energy Technology Data Exchange (ETDEWEB)

    Fauvelle, F. [Unite de Biophysique Cellulaire et Moleculaire, Institut de Recherche Biomedicale des Armees, Centre de Recherches du Service Sante des Armees, BP87, 38 702 La Tronche Cedex (France); Dorandeu, F.; Carpentier, P.; Foquin, A. [Departement de Toxicologie, Institut de Recherche Biomedicale des Armees, Centre de Recherches du Service Sante des Armees, 24 avenue des Maquis du Gresivaudan, BP87, 38 702 La Tronche Cedex (France); Rabeson, H.; Graveron-Demilly, D. [Universite Lyon 1, Laboratoire Creatis-LRMN, CNRS UMR 5220, INSERM U630, INSA de Lyon (France); Arvers, P. [Unite de Biophysique Cellulaire et Moleculaire, Institut de Recherche Biomedicale des Armees, Centre de Recherches du Service Sante des Armees, BP87, 38 702 La Tronche Cedex (France); Testylier, G., E-mail: guytestylier@crssa.net [Departement de Toxicologie, Institut de Recherche Biomedicale des Armees, Centre de Recherches du Service Sante des Armees, 24 avenue des Maquis du Gresivaudan, BP87, 38 702 La Tronche Cedex (France)

    2010-01-12

    Soman, an irreversible organophosphorus cholinesterase inhibitor, induces status epilepticus and, in sensitive brain areas, seizure-related brain damage (e.g. brain edema and neuronal loss). The brain metabolic disturbances associated with these events are ill known. In the present study, we thus evaluated these changes in a murine model of soman-induced status epilepticus up to 7 days after intoxication. Mice, protected by HI-6 and atropine methyl nitrate, were poisoned with soman (172 μg/kg) and then sacrificed at set time points, from 1 h to 7 days. Brain biopsies from the piriform cortex (Pir) and cerebellum (Cer) were analyzed by {sup 1}H HRMAS NMR spectroscopy. Spectra were then analyzed using both a supervised multivariate analysis and the QUEST procedure of jMRUI for the quantification of 17 metabolites. The multivariate analysis clearly showed the metabolic differences between a damaged structure (Pir) and a structure with less prominent changes (cerebellum) and helped to globally assess the time course of metabolic changes. Analysis of the individual metabolites showed that the major changes took place in the piriform cortex but that cerebellum was not change-free. The most prominent changes in the former were an early (1-4 h) increase in alanine and acetate, a delayed increase in lactate, glycerophosphocholine and glutamine as well as a delayed decrease in myo-inositol and N-acetylaspartate. A week after poisoning, some metabolic disturbances were still present. Further research will be necessary to clarify what could be the involvement of these metabolites in physiological processes and how they might become useful surrogate markers of brain damage and repair.

  13. Changes in mouse brain metabolism following a convulsive dose of soman: A proton HRMAS NMR study

    International Nuclear Information System (INIS)

    Fauvelle, F.; Dorandeu, F.; Carpentier, P.; Foquin, A.; Rabeson, H.; Graveron-Demilly, D.; Arvers, P.; Testylier, G.

    2010-01-01

    Soman, an irreversible organophosphorus cholinesterase inhibitor, induces status epilepticus and, in sensitive brain areas, seizure-related brain damage (e.g. brain edema and neuronal loss). The brain metabolic disturbances associated with these events are ill known. In the present study, we thus evaluated these changes in a murine model of soman-induced status epilepticus up to 7 days after intoxication. Mice, protected by HI-6 and atropine methyl nitrate, were poisoned with soman (172 μg/kg) and then sacrificed at set time points, from 1 h to 7 days. Brain biopsies from the piriform cortex (Pir) and cerebellum (Cer) were analyzed by 1 H HRMAS NMR spectroscopy. Spectra were then analyzed using both a supervised multivariate analysis and the QUEST procedure of jMRUI for the quantification of 17 metabolites. The multivariate analysis clearly showed the metabolic differences between a damaged structure (Pir) and a structure with less prominent changes (cerebellum) and helped to globally assess the time course of metabolic changes. Analysis of the individual metabolites showed that the major changes took place in the piriform cortex but that cerebellum was not change-free. The most prominent changes in the former were an early (1-4 h) increase in alanine and acetate, a delayed increase in lactate, glycerophosphocholine and glutamine as well as a delayed decrease in myo-inositol and N-acetylaspartate. A week after poisoning, some metabolic disturbances were still present. Further research will be necessary to clarify what could be the involvement of these metabolites in physiological processes and how they might become useful surrogate markers of brain damage and repair.

  14. Changes in chemical composition of litter during decomposition: a review of published 13C NMR spectra

    Czech Academy of Sciences Publication Activity Database

    Cepáková, Šárka; Frouz, Jan

    2015-01-01

    Roč. 15, č. 3 (2015), s. 805-815 ISSN 0718-9516 Grant - others:GAJU(CZ) GAJU/04-146/2013P; GA ČR(CZ) GAP504/12/1288 Program:GA Institutional support: RVO:60077344 Keywords : 13C CPMAS NMR * litter decomposition * litter quality * soil organic matter Subject RIV: DF - Soil Science Impact factor: 1.600, year: 2015

  15. Automatic Assignment of Methyl-NMR Spectra of Supramolecular Machines Using Graph Theory.

    Science.gov (United States)

    Pritišanac, Iva; Degiacomi, Matteo T; Alderson, T Reid; Carneiro, Marta G; Ab, Eiso; Siegal, Gregg; Baldwin, Andrew J

    2017-07-19

    Methyl groups are powerful probes for the analysis of structure, dynamics and function of supramolecular assemblies, using both solution- and solid-state NMR. Widespread application of the methodology has been limited due to the challenges associated with assigning spectral resonances to specific locations within a biomolecule. Here, we present Methyl Assignment by Graph Matching (MAGMA), for the automatic assignment of methyl resonances. A graph matching protocol examines all possibilities for each resonance in order to determine an exact assignment that includes a complete description of any ambiguity. MAGMA gives 100% accuracy in confident assignments when tested against both synthetic data, and 9 cross-validated examples using both solution- and solid-state NMR data. We show that this remarkable accuracy enables a user to distinguish between alternative protein structures. In a drug discovery application on HSP90, we show the method can rapidly and efficiently distinguish between possible ligand binding modes. By providing an exact and robust solution to methyl resonance assignment, MAGMA can facilitate significantly accelerated studies of supramolecular machines using methyl-based NMR spectroscopy.

  16. Analysis of NMR spectra of sugar chains of glycolipids by multiple relayed COSY and 2D homonuclear Hartman-Hahn spectroscopy

    International Nuclear Information System (INIS)

    Inagaki, F.; Kohda, D.; Kodama, C.; Suzuki, A.

    1987-01-01

    The authors applied multiple relayed COSY and 2D homonuclear Hartman-Hahn spectroscopy to globoside, a glycolipid purified from human red blood cells. The subspectra corresponding to individual sugar components were extracted even from overlapping proton resonances by taking the cross sections of 2D spectra parallel to the F 2 axis at anomeric proton resonances, so that unambiguous assignments of sugar proton resonances were accomplished. (Auth.)

  17. Proton NMR relaxivity of blood samples in the presence of some gadolinium and dysprosium compounds

    International Nuclear Information System (INIS)

    Coroiu, I.; Darabont, Al.; Bogdan, M.

    1999-01-01

    The use of some new compounds in MRI tissue and blood characterisation based on nuclear spin relaxation time measurements cannot be sustained until the molecular sources of these variations are understood. Tissues and blood are complex molecular systems with complex NMR properties. A better comprehension of the molecular basis of relaxation offers the possibility to predict the changes expected for a given pathology. The purpose of this contribution is to evidence the different relaxation characteristics of some gadolinium and dysprosium compounds in the presence and absence of the blood and to give a possible explanation about the molecular processes that cause occurrence of changes. Some gadolinium and dysprosium compounds such as: Gd-CIT (gadolinium citrate), Dy-DTPA (DTPA-diethylenetriamine pentaacetic acid), iron oxide - gadolinium oxide (or dysprosium oxide)- dextran complexes were prepared. The longitudinal T 1 -1 and transverse T 2 -1 'relaxation rates' measurements have been carried out as a function of molar concentrations. All measurements have been made at room temperature (about 25 deg.C) and the proton Larmor frequency ν o = 90 MHz. The pulsed NMR spectrometer utilised was a commercial Bruker SXP4/100 spectrometer. Transverse relaxation rate measurements have been made using the Carr-Purcell method, while longitudinal relaxation rate measurements using the inversion recovery pulse sequence, 180 angle-τ-90 angle. The accuracy was about 2-3% for the longitudinal relaxation rates and about 5-7% for the transverse relaxation rates. R 1 and R 2 relaxivities, in mM -1 s -1 were determined from the least square determination of the slopes of plots 1/T 1,2 versus compound molar concentration, using at least five independent measurements at several concentrations between 0 and 2 mM. Increased R 2 relaxivity observed for dysprosium compounds in the blood presence can be explained by PRE effect. The largest gain in R 2 relaxivity seems to imply a noncovalent

  18. New NMR method for measuring the difference between corresponding proton and deuterium chemical shifts: isotope effects on exchange equilibria

    International Nuclear Information System (INIS)

    Saunders, M.; Saunders, S.; Johnson, C.A.

    1984-01-01

    A convenient and accurate method is described for measuring the difference between a proton frequency and the corresponding deuterium frequency in its deuterated analogue relative to a reference system by using the deuterium lock in a Fourier-transform NMR spectrometer. This measurement is a sensitive way of measuring equilibrium isotope effects for hydrogen-deuterium exchange. A value of 1.60 per H-D pair is obtained for the equilibrium 2H 3 O + + 3D 2 O in equilibrium 2D 3 O + + 3H 2 O at 30 0 C in aqueous perchloric acid (HClO 4 ). 7 references, 2 tables

  19. Automated NMR structure determination of stereo-array isotope labeled ubiquitin from minimal sets of spectra using the SAIL-FLYA system

    Energy Technology Data Exchange (ETDEWEB)

    Ikeya, Teppei [Goethe University Frankfurt am Main, Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance (Germany); Takeda, Mitsuhiro; Yoshida, Hitoshi; Terauchi, Tsutomu; Jee, Jun-Goo; Kainosho, Masatsune [Tokyo Metropolitan University, Graduate School of Science (Japan)], E-mail: kainosho@nmr.chem.metro-u.ac.jp; Guentert, Peter [Goethe University Frankfurt am Main, Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance (Germany)], E-mail: guentert@em.uni-frankfurt.de

    2009-08-15

    Stereo-array isotope labeling (SAIL) has been combined with the fully automated NMR structure determination algorithm FLYA to determine the three-dimensional structure of the protein ubiquitin from different sets of input NMR spectra. SAIL provides a complete stereo- and regio-specific pattern of stable isotopes that results in sharper resonance lines and reduced signal overlap, without information loss. Here we show that as a result of the superior quality of the SAIL NMR spectra, reliable, fully automated analyses of the NMR spectra and structure calculations are possible using fewer input spectra than with conventional uniformly {sup 13}C/{sup 15}N-labeled proteins. FLYA calculations with SAIL ubiquitin, using a single three-dimensional 'through-bond' spectrum (and 2D HSQC spectra) in addition to the {sup 13}C-edited and {sup 15}N-edited NOESY spectra for conformational restraints, yielded structures with an accuracy of 0.83-1.15 A for the backbone RMSD to the conventionally determined solution structure of SAIL ubiquitin. NMR structures can thus be determined almost exclusively from the NOESY spectra that yield the conformational restraints, without the need to record many spectra only for determining intermediate, auxiliary data of the chemical shift assignments. The FLYA calculations for this report resulted in 252 ubiquitin structure bundles, obtained with different input data but identical structure calculation and refinement methods. These structures cover the entire range from highly accurate structures to seriously, but not trivially, wrong structures, and thus constitute a valuable database for the substantiation of structure validation methods.

  20. Automated NMR structure determination of stereo-array isotope labeled ubiquitin from minimal sets of spectra using the SAIL-FLYA system

    International Nuclear Information System (INIS)

    Ikeya, Teppei; Takeda, Mitsuhiro; Yoshida, Hitoshi; Terauchi, Tsutomu; Jee, Jun-Goo; Kainosho, Masatsune; Guentert, Peter

    2009-01-01

    Stereo-array isotope labeling (SAIL) has been combined with the fully automated NMR structure determination algorithm FLYA to determine the three-dimensional structure of the protein ubiquitin from different sets of input NMR spectra. SAIL provides a complete stereo- and regio-specific pattern of stable isotopes that results in sharper resonance lines and reduced signal overlap, without information loss. Here we show that as a result of the superior quality of the SAIL NMR spectra, reliable, fully automated analyses of the NMR spectra and structure calculations are possible using fewer input spectra than with conventional uniformly 13 C/ 15 N-labeled proteins. FLYA calculations with SAIL ubiquitin, using a single three-dimensional 'through-bond' spectrum (and 2D HSQC spectra) in addition to the 13 C-edited and 15 N-edited NOESY spectra for conformational restraints, yielded structures with an accuracy of 0.83-1.15 A for the backbone RMSD to the conventionally determined solution structure of SAIL ubiquitin. NMR structures can thus be determined almost exclusively from the NOESY spectra that yield the conformational restraints, without the need to record many spectra only for determining intermediate, auxiliary data of the chemical shift assignments. The FLYA calculations for this report resulted in 252 ubiquitin structure bundles, obtained with different input data but identical structure calculation and refinement methods. These structures cover the entire range from highly accurate structures to seriously, but not trivially, wrong structures, and thus constitute a valuable database for the substantiation of structure validation methods

  1. Automated NMR structure determination of stereo-array isotope labeled ubiquitin from minimal sets of spectra using the SAIL-FLYA system.

    Science.gov (United States)

    Ikeya, Teppei; Takeda, Mitsuhiro; Yoshida, Hitoshi; Terauchi, Tsutomu; Jee, Jun-Goo; Kainosho, Masatsune; Güntert, Peter

    2009-08-01

    Stereo-array isotope labeling (SAIL) has been combined with the fully automated NMR structure determination algorithm FLYA to determine the three-dimensional structure of the protein ubiquitin from different sets of input NMR spectra. SAIL provides a complete stereo- and regio-specific pattern of stable isotopes that results in sharper resonance lines and reduced signal overlap, without information loss. Here we show that as a result of the superior quality of the SAIL NMR spectra, reliable, fully automated analyses of the NMR spectra and structure calculations are possible using fewer input spectra than with conventional uniformly 13C/15N-labeled proteins. FLYA calculations with SAIL ubiquitin, using a single three-dimensional "through-bond" spectrum (and 2D HSQC spectra) in addition to the 13C-edited and 15N-edited NOESY spectra for conformational restraints, yielded structures with an accuracy of 0.83-1.15 A for the backbone RMSD to the conventionally determined solution structure of SAIL ubiquitin. NMR structures can thus be determined almost exclusively from the NOESY spectra that yield the conformational restraints, without the need to record many spectra only for determining intermediate, auxiliary data of the chemical shift assignments. The FLYA calculations for this report resulted in 252 ubiquitin structure bundles, obtained with different input data but identical structure calculation and refinement methods. These structures cover the entire range from highly accurate structures to seriously, but not trivially, wrong structures, and thus constitute a valuable database for the substantiation of structure validation methods.

  2. Measurement of the relaxation rate of the magnetization in Mn12O12-acetate using proton NMR echo

    Science.gov (United States)

    Jang; Lascialfari; Borsa; Gatteschi

    2000-03-27

    We present a novel method to measure the relaxation rate W of the magnetization of Mn 12O (12)-acetate (Mn12) magnetic molecular cluster in its S = 10 ground state at low T. It is based on the observation of an exponential growth in time of the proton NMR signal during the thermal equilibration of the magnetization of the molecules. We can explain the novel effect with a simple model which relates the intensity of the proton echo signal to the microscopic reversal of the magnetization of each individual Mn12 molecule during the equilibration process. The method should find wide application in the study of magnetic molecular clusters in off-equilibrium conditions.

  3. Measurement of the Relaxation Rate of the Magnetization in Mn12O12 -Acetate Using Proton NMR Echo

    International Nuclear Information System (INIS)

    Jang, Z. H.; Lascialfari, A.; Borsa, F.; Gatteschi, D.

    2000-01-01

    We present a novel method to measure the relaxation rate W of the magnetization of Mn 12 O 12 -acetate (Mn12) magnetic molecular cluster in its S=10 ground state at low T . It is based on the observation of an exponential growth in time of the proton NMR signal during the thermal equilibration of the magnetization of the molecules. We can explain the novel effect with a simple model which relates the intensity of the proton echo signal to the microscopic reversal of the magnetization of each individual Mn12 molecule during the equilibration process. The method should find wide application in the study of magnetic molecular clusters in off-equilibrium conditions. (c) 2000 The American Physical Society

  4. NMR water-proton spin-lattice relaxation time of human red blood cells and red blood cell suspensions

    International Nuclear Information System (INIS)

    Sullivan, S.G.; Rosenthal, J.S.; Winston, A.; Stern, A.

    1988-01-01

    NMR water-proton spin-lattice relaxation times were studied as probes of water structure in human red blood cells and red blood cell suspensions. Normal saline had a relaxation time of about 3000 ms while packed red blood cells had a relaxation time of about 500 ms. The relaxation time of a red blood cell suspension at 50% hematocrit was about 750 ms showing that surface charges and polar groups of the red cell membrane effectively structure extracellular water. Incubation of red cells in hypotonic saline increases relaxation time whereas hypertonic saline decreases relaxation time. Relaxation times varied independently of mean corpuscular volume and mean corpuscular hemoglobin concentration in a sample population. Studies with lysates and resealed membrane ghosts show that hemoglobin is very effective in lowering water-proton relaxation time whereas resealed membrane ghosts in the absence of hemoglobin are less effective than intact red cells. 9 refs.; 3 figs.; 1 table

  5. Measured Neutron Spectra and Dose Equivalents From a Mevion Single-Room, Passively Scattered Proton System Used for Craniospinal Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Howell, Rebecca M., E-mail: rhowell@mdanderson.org [Department of Radiation Physics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Burgett, Eric A.; Isaacs, Daniel [Department of Nuclear Engineering, Idaho State University, Pocatello, Idaho (United States); Price Hedrick, Samantha G.; Reilly, Michael P.; Rankine, Leith J.; Grantham, Kevin K.; Perkins, Stephanie; Klein, Eric E. [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States)

    2016-05-01

    Purpose: To measure, in the setting of typical passively scattered proton craniospinal irradiation (CSI) treatment, the secondary neutron spectra, and use these spectra to calculate dose equivalents for both internal and external neutrons delivered via a Mevion single-room compact proton system. Methods and Materials: Secondary neutron spectra were measured using extended-range Bonner spheres for whole brain, upper spine, and lower spine proton fields. The detector used can discriminate neutrons over the entire range of the energy spectrum encountered in proton therapy. To separately assess internally and externally generated neutrons, each of the fields was delivered with and without a phantom. Average neutron energy, total neutron fluence, and ambient dose equivalent [H* (10)] were calculated for each spectrum. Neutron dose equivalents as a function of depth were estimated by applying published neutron depth–dose data to in-air H* (10) values. Results: For CSI fields, neutron spectra were similar, with a high-energy direct neutron peak, an evaporation peak, a thermal peak, and an intermediate continuum between the evaporation and thermal peaks. Neutrons in the evaporation peak made the largest contribution to dose equivalent. Internal neutrons had a very low to negligible contribution to dose equivalent compared with external neutrons, largely attributed to the measurement location being far outside the primary proton beam. Average energies ranged from 8.6 to 14.5 MeV, whereas fluences ranged from 6.91 × 10{sup 6} to 1.04 × 10{sup 7} n/cm{sup 2}/Gy, and H* (10) ranged from 2.27 to 3.92 mSv/Gy. Conclusions: For CSI treatments delivered with a Mevion single-gantry proton therapy system, we found measured neutron dose was consistent with dose equivalents reported for CSI with other proton beamlines.

  6. Protonation effects on the UV/Vis absorption spectra of imatinib: a theoretical and experimental study.

    Science.gov (United States)

    Grante, Ilze; Actins, Andris; Orola, Liana

    2014-08-14

    An experimental and theoretical investigation of protonation effects on the UV/Vis absorption spectra of imatinib showed systematic changes of absorption depending on the pH, and a new absorption band appeared below pH 2. These changes in the UV/Vis absorption spectra were interpreted using quantum chemical calculations. The geometry of various imatinib cations in the gas phase and in ethanol solution was optimized with the DFT/B3LYP method. The resultant geometries were compared to the experimentally determined crystal structures of imatinib salts. The semi-empirical ZINDO-CI method was employed to calculate the absorption lines and electronic transitions. Our study suggests that the formation of the extra near-UV absorption band resulted from an increase of imatinib trication concentration in the solution, while the rapid increase of the first absorption maximum could be attributed to both the formation of imatinib trication and tetracation. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. An analysis of the NMR-CT image by the measurement of proton-relaxation times in tissue

    International Nuclear Information System (INIS)

    Naruse, Shoji; Horikawa, Yoshiharu; Tanaka, Chuzo; Hirakawa, Kimiyoshi; Nishikawa, Hiroyasu; Shimizu, Koji; Kiri, Motosada.

    1984-01-01

    NMR-CT images were analyzed by measuring the proton-relaxation times in tissues. The NMR-CT images were obtained in 10 normal volunteers and 16 patients with brain tumors with a prototype superconducting magnet (Shimadzu Corp., Japan) operating at 0.2 T and 0.375 T. A smooth T 1 relaxation curve was obtained in each part of the brain and the brain tumor by the use of the data of the NMR-CT image; consequently, the in vivo T 1 value was proved to be reliable. The in vivo T 1 value showed the specific value corresponding to each region of the normal brain in all cases. Cerebral gray matter normally had the longest T 1 value, followed by the medulla oblongata, the pons, and white matter. The T 1 value of each region of the brain varied to the same degree in proportion to the strength of the static magnetic field. The in vivo T 1 values of the brain tumor varied with the histological type. All were longer than any part of the brain parenchyma, being between 480 and 780 msec at 0.2 T. The prolongation of the T 1 value does not always correspond to the degree of the malignancy in a tumor. The in vitro T 1 and T 2 values were also prolonged in all tumors. Although the absolute value of T 1 did not coincide between the in vitro and in vivo data, the tendency of the prolongation was the same between them. This result indicated that the NMR-CT images could be analysed by the use of the data of the in vitro T 1 and T 2 values in the tumor tissues. It is important to analyse the NMR-CT image by both in vivo and in vitro examinations of the relaxation times. (J.P.N.)

  8. Hydroxy protons as structural probes to reveal hydrogen bonding properties of polyols in aqueous solution by NMR spectroscopy

    Science.gov (United States)

    Oruc, Gizem; Varnali, Tereza; Bekiroglu, Somer

    2018-05-01

    The solution properties of ethylene glycol (ethane-1,2-diol), glycerol (propane-1,2,3-triol), erythritol ((2R,3S)-butane-1,2,3,4-tetraol), D-xylitol ((2R,3r,4S)-pentane-1,2,3,4,5-pentaol), D-mannitol ((2R,3R,4R,5R)-hexane-1,2,3,4,5,6-hexaol), and D-sorbitol ((2S,3R,4R,5R)-hexane-1,2,3,4,5,6-hexaol), constituting a subgroup of polyalcohols/polyols of maximum six carbon atoms have been investigated using 1H NMR chemical shifts, coupling constants, temperature coefficients, and chemical exchange rates of hydroxy protons in aqueous medium. Relative within a molecule, minimum two-fold difference in rate of exchange values and higher temperature dependence of chemical shifts of the hydroxy protons on terminal carbon atoms confirm that sustainable hydrogen bonding interactions is accentuated for the hydroxyl groups on secondary carbons. Compared to the primary carbons i.e. terminal ones, the hydroxy protons on second and third carbon atoms exhibit much lower rate of exchange and smaller temperature coefficients, indicating that they are further involved in transient hydrogen bonding interactions. Scalar 3JOH,CH-couplings ranging between 3.9 and 7.2 Hz imply that the hydroxyl groups are practically in free rotation regime. Examination of the chemical shift differences with respect to the shift of glycol hydroxy proton reveals that the disparity between terminal and inner hydroxyl groups disclosed by the exchange rates and temperature coefficients is sustained with the exception of 0.003 and 0.053 ppm for O(3)H of mannitol and O(5)H of sorbitol respectively. The experimental findings have been augmented by quantum chemical calculations targeting theoretical NMR chemical shifts, as well as the conformational analysis of the structures.

  9. Identifying inter-residue resonances in crowded 2D {sup 13}C-{sup 13}C chemical shift correlation spectra of membrane proteins by solid-state MAS NMR difference spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Miao Yimin; Cross, Timothy A. [Florida State University, Department of Chemistry and Biochemistry (United States); Fu Riqiang, E-mail: rfu@magnet.fsu.edu [National High Magnet Field Lab (United States)

    2013-07-15

    The feasibility of using difference spectroscopy, i.e. subtraction of two correlation spectra at different mixing times, for substantially enhanced resolution in crowded two-dimensional {sup 13}C-{sup 13}C chemical shift correlation spectra is presented. With the analyses of {sup 13}C-{sup 13}C spin diffusion in simple spin systems, difference spectroscopy is proposed to partially separate the spin diffusion resonances of relatively short intra-residue distances from the longer inter-residue distances, leading to a better identification of the inter-residue resonances. Here solid-state magic-angle-spinning NMR spectra of the full length M2 protein embedded in synthetic lipid bilayers have been used to illustrate the resolution enhancement in the difference spectra. The integral membrane M2 protein of Influenza A virus assembles as a tetrameric bundle to form a proton-conducting channel that is activated by low pH and is essential for the viral lifecycle. Based on known amino acid resonance assignments from amino acid specific labeled samples of truncated M2 sequences or from time-consuming 3D experiments of uniformly labeled samples, some inter-residue resonances of the full length M2 protein can be identified in the difference spectra of uniformly {sup 13}C labeled protein that are consistent with the high resolution structure of the M2 (22-62) protein (Sharma et al., Science 330(6003):509-512, 2010)

  10. Analysis of accelerator based neutron spectra for BNCT using proton recoil spectroscopy

    International Nuclear Information System (INIS)

    Wielopolski, L.; Ludewig, H.; Powell, J.R.; Raparia, D.; Alessi, J.G.; Lowenstein, D.I.

    1998-01-01

    Boron Neutron Capture Therapy (BNCT) is a promising binary treatment modality for high-grade primary brain tumors (glioblastoma multiforme, GM) and other cancers. BNCT employs a boron-10 containing compound that preferentially accumulates in the cancer cells in the brain. Upon neutron capture by 10 B energetic alpha particles and triton released at the absorption site kill the cancer cell. In order to gain penetration depth in the brain Fairchild proposed, for this purpose, the use of energetic epithermal neutrons at about 10 keV. Phase I/II clinical trials of BNCT for GM are underway at the Brookhaven Medical Research Reactor (BMRR) and at the MIT Reactor, using these nuclear reactors as the source for epithermal neutrons. In light of the limitations of new reactor installations, e.g. cost, safety and licensing, and limited capability for modulating the reactor based neutron beam energy spectra alternative neutron sources are being contemplated for wider implementation of this modality in a hospital environment. For example, accelerator based neutron sources offer the possibility of tailoring the neutron beams, in terms of improved depth-dose distributions, to the individual and offer, with relative ease, the capability of modifying the neutron beam energy and port size. In previous work new concepts for compact accelerator/target configuration were published. In this work, using the Van de Graaff accelerator the authors have explored different materials for filtering and reflecting neutron beams produced by irradiating a thick Li target with 1.8 to 2.5 MeV proton beams. However, since the yield and the maximum neutron energy emerging from the Li-7(p,n)Be-7 reaction increase with increase in the proton beam energy, there is a need for optimization of the proton energy versus filter and shielding requirements to obtain the desired epithermal neutron beam. The MCNP-4A computer code was used for the initial design studies that were verified with benchmark experiments

  11. Estimation of diffusion coefficients in bitumen solvent mixtures as derived from low field NMR spectra

    International Nuclear Information System (INIS)

    Wen, Y.; Bryan, J.; Kantzas, A.

    2005-01-01

    Use of solvents for the extraction of heavy oil and bitumen appears to be an increasingly feasible technology. Both vapour extraction and direct solvent injection are considered for conventional exploration and production schemes, while solvent dilution of bitumen is a standard technique in oil sands mining. Mass transfer between solvent and bitumen is a poorly understood process. In some cases, it is totally ignored compared to viscous force effects. In other cases, phenomenological estimations of diffusion and dispersion coefficients are used. Low field NMR has been used successfully in determining both solvent content and viscosity reduction in heavy oil and bitumen mixtures with various solvents. As a solvent comes into contact with a heavy oil or bitumen sample, the mobility of hydrogen bearing molecules of both solvent and oil changes. These changes are detectable through changes in the NMR relaxation characteristics of both solvent and oil. Relaxation changes can then be correlated to mass flux and concentration changes. Based on Fick's Second Law, a diffusion coefficient, which is independent of concentration, was calculated against three oils and six solvents. (author)

  12. Communication: Proton NMR dipolar-correlation effect as a method for investigating segmental diffusion in polymer melts

    International Nuclear Information System (INIS)

    Lozovoi, A.; Mattea, C.; Stapf, S.; Herrmann, A.; Rössler, E. A.; Fatkullin, N.

    2016-01-01

    A simple and fast method for the investigation of segmental diffusion in high molar mass polymer melts is presented. The method is based on a special function, called proton dipolar-correlation build-up function, which is constructed from Hahn Echo signals measured at times t and t/2. The initial rise of this function contains additive contributions from both inter- and intramolecular magnetic dipole-dipole interactions. The intermolecular contribution depends on the relative mean squared displacements (MSDs) of polymer segments from different macromolecules, while the intramolecular part reflects segmental reorientations. Separation of both contributions via isotope dilution provides access to segmental displacements in polymer melts at millisecond range, which is hardly accessible by other methods. The feasibility of the method is illustrated by investigating protonated and deuterated polybutadiene melts with molecular mass 196 000 g/mol at different temperatures. The observed exponent of the power law of the segmental MSD is close to 0.32 ± 0.03 at times when the root MSD is in between 45 Å and 75 Å, and the intermolecular proton dipole-dipole contribution to the total proton Hahn Echo NMR signal is larger than 50% and increases with time.

  13. Direct 13C NMR Detection in HPLC Hyphenation Mode

    DEFF Research Database (Denmark)

    Wubshet, Sileshi Gizachew; Johansen, Kenneth; Nyberg, Nils

    2012-01-01

    Solid phase extraction (SPE) was introduced as a crucial step in the HPLC-SPE-NMR technique to enable online analyte enrichment from which proton-detected NMR experiments on submicrogram amounts from complex mixtures were possible. However, the significance of direct-detected (13)C NMR experiments...... application of HPLC-SPE-NMR analysis using direct-detected (13)C NMR spectra. HPLC column loading, accumulative SPE trappings, and the effect of different elution solvents were evaluated and optimized. A column loading of approximately 600 mug of a prefractionated triterpenoid mixture, six trappings...

  14. Production spectra of $\\pi ^{\\pm}$, K$^{\\pm}$, p$^{\\pm}$ at large angles in proton-proton collisions in the CERN intersecting storage rings

    CERN Document Server

    Alper, B; Booth, P; Bulos, F; Carroll, L J; Damgaard, G; Duff, Brian G; Hansen, K H; Heymann, Franz F; Jackson, J N; Jarlskog, G; Jönsson, L B; Klovning, A; Leistam, L; Lillethun, E; Lohse, E; Lynch, G; Manning, Geoffrey; Ølgaard-Nielsen, S; Potter, K; Prentice, M; Quarrie, D; Sharp, P; Sharrock, S; von Dardel, Guy F; Weiss, J M

    1975-01-01

    Results are given on the inclusive production of charged pions, kaons, and nucleons, in proton-proton collisions at c.m. energies from square root s=23 to 63 GeV at large angles and for the transverse momentum range 0.1

    spectra on the collision energy square root s, the transverse momentum p/sub T /, and the longitudinal rapidity is discussed. (19 refs).

  15. Magnetization transfer from macromolecules to water protons in murine dental tissues as revealed by 500 MHz 1H-NMR

    International Nuclear Information System (INIS)

    Nakamura, Koji; Era, Seiichi; Nagai, Naoki; Sogami, Masaru; Takasaki, Akihiko; Kato, Kazuo.

    1997-01-01

    Although much is known about magnetization transfer phenomena in biological soft tissues, little is known about those in hard tissues. Using a 500 MHz 1 H-NMR spectrometer, we studied the spin-lattice relaxation time (T 1 (H 2 O)) and the intermolecular cross-relaxation times (T IS (H 2 O)) from irradiated macromolecular protons to observed water protons in murine lower incisors (hard tissue) and compared with those in murine lens tissue (soft tissue). Mean values for the water content (%) of murine lower incisors and lens tissue were 16.02±2.39 (n=14) and 67.20±4.60 (n=15), respectively. These findings were consistent with the large different in water content between soft tissues and hard tissues. T IS (H 2 O) values obtained by f 2 -irradiation at 7.13 or -4.00 ppm showed no significant difference between lower incisors and lens tissue. Plots of 1/T IS (H 2 O) values vs. tissue dry weight (W(%)) for lower incisor tissue approximated a straight line with slope approximately equal for that obtained for lens tissue. These results suggest that the state of water in hard tissue may be similar to that in soft tissues, in spite of the significant difference in water content. Thus, saturation transfer NMR techniques such as measurement of T IS (H 2 O) values may be applicable to the study of water-macromolecule interactions in both biological soft and hard tissues. (author)

  16. Proton and deuterium NMR experiments in zero field. [Perdeuterated p-demethoxybenzene, perdeuterated malonic acid, diethyl terephthalate-d4, nonadecane-2,2'-D2, sodium propionate-D2

    Energy Technology Data Exchange (ETDEWEB)

    Millar, J.M.

    1986-02-01

    High field solid-state NMR lineshapes suffer from inhomogeneous broadening since resonance frequencies are a function of molecular orientation. Time domain zero field NMR is a two-dimensional field-cycling technique which removes this broadening by probing the evolution of the spin system under zero applied field. The simplest version, the sudden transition experiment, induces zero field evolution by the sudden removal of the applied magnetic field. Theory and experimental results of this experiment and several variations using pulsed dc magnetic fuelds to initiate zero field evolution are presented. In particular, the pulsed indirect detection method allows detection of the zero field spectrum of one nuclear spin species via another (usually protons) by utilizing the level crossings which occur upon adiabatic demagnetization to zero field. Experimental examples of proton/deuteron systems are presented which demonstrate the method results in enhanced sensitivity relative to that obtained in sudden transition experiments performed directly on deuterium. High resolution /sup 2/H NQR spectra of a series of benzoic acid derivatives are obtained using the sudden transition and indirect detection methods. Librational oscillations in the water molecules of barium chlorate monohydrate are studied using proton and deuterium ZF experiments. 177 refs., 88 figs., 2 tabs.

  17. Evidencing of collagen polypeptide sequences responsible of hydration by means of 13 C NMR spectra

    International Nuclear Information System (INIS)

    Trandafir, Viorica; Georgescu, Mariana; Albu, Bujor; Popescu, G.; Akutsu, Hiroshi; Nechifor, Gheorghe

    2000-01-01

    The aim of these studies is to prepare biomaterials of high biocompatibility to the human body, provided for a long lifetime. Among these important biomaterials also accounts the collagen, with a large application area in medicine, pharmaceutics, cosmetics, etc. Collagen biomaterials of various hydration levels (between 23 - 83%) were prepared by a particular technique, using a matrix of 23% initial humidity. In order to investigate the structural and conformational changes from the collagen macromolecules by denaturation - renaturation, hydration - dehydration, the high-resolution 13 C - NMR solid state and also pore size distribution analysis were carried out. The collagen biomaterials can be made in a large range of shapes and can have structures of mimesis, close to those of the live tissues, when hydrated. (authors)

  18. Application of unsymmetrical indirect covariance NMR methods to the computation of the (13)C (15)N HSQC-IMPEACH and (13)C (15)N HMBC-IMPEACH correlation spectra.

    Science.gov (United States)

    Martin, Gary E; Hilton, Bruce D; Irish, Patrick A; Blinov, Kirill A; Williams, Antony J

    2007-10-01

    Utilization of long-range (1)H--(15)N heteronuclear chemical shift correlation has continually grown in importance since the first applications were reported in 1995. More recently, indirect covariance NMR methods have been introduced followed by the development of unsymmetrical indirect covariance processing methods. The latter technique has been shown to allow the calculation of hyphenated 2D NMR data matrices from more readily acquired nonhyphenated 2D NMR spectra. We recently reported the use of unsymmetrical indirect covariance processing to combine (1)H--(13)C GHSQC and (1)H--(15)N GHMBC long-range spectra to yield a (13)C--(15)N HSQC-HMBC chemical shift correlation spectrum that could not be acquired in a reasonable period of time without resorting to (15)N-labeled molecules. We now report the unsymmetrical indirect covariance processing of (1)H--(13)C GHMBC and (1)H--(15)N IMPEACH spectra to afford a (13)C--(15)N HMBC-IMPEACH spectrum that has the potential to span as many as six to eight bonds. Correlations for carbon resonances long-range coupled to a protonated carbon in the (1)H--(13)C HMBC spectrum are transferred via the long-range (1)H--(15)N coupling pathway in the (1)H--(15)N IMPEACH spectrum to afford a much broader range of correlation possibilities in the (13)C--(15)N HMBC-IMPEACH correlation spectrum. The indole alkaloid vincamine is used as a model compound to illustrate the application of the method. (c) 2007 John Wiley & Sons, Ltd.

  19. Stereochemistry of C18 monounsaturated cork suberin acids determined by spectroscopic techniques including (1) H-NMR multiplet analysis of olefinic protons.

    Science.gov (United States)

    Santos, Sara; Graça, José

    2014-01-01

    Suberin is a biopolyester responsible for the protection of secondary plant tissues, and yet its molecular structure remains unknown. The C18:1 ω-hydroxyacid and the C18:1 α,ω-diacid are major monomers in the suberin structure, but the configuration of the double bond remains to be elucidated. To unequivocally define the configuration of the C18:1 suberin acids. Pure C18:1 ω-hydroxyacid and C18:1 α,ω-diacid, isolated from cork suberin, and two structurally very close C18:1 model compounds of known stereochemistry, methyl oleate and methyl elaidate, were analysed by NMR spectroscopy, Fourier transform infrared (FTIR) and Raman spectroscopy, and GC-MS. The GC-MS analysis showed that both acids were present in cork suberin as only one geometric isomer. The analysis of dimethyloxazoline (DMOX) and picolinyl derivatives proved the double bond position to be at C-9. The FTIR spectra were concordant with a cis-configuration for both suberin acids, but their unambiguous stereochemical assignment came from the NMR analysis: (i) the chemical shifts of the allylic (13) C carbons were shielded comparatively to the trans model compound, and (ii) the complex multiplets of the olefinic protons could be simulated only with (3) JHH and long-range (4) JHH coupling constants typical of a cis geometry. The two C18:1 suberin acids in cork are (Z)-18-hydroxyoctadec-9-enoic acid and (Z)-octadec-9-enedoic acid. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Spectroscopic effects in 1H and 13C NMR spectra of 4,4'-di-substituted 3,3'-diquinolines sulfides

    International Nuclear Information System (INIS)

    Pluta, K.

    1994-01-01

    The 1 H and 13 C NMR spectra of 4,4'-disubstituted sulfides of 3,3'-quinolines have been studied in CDCl 3 solutions. The observed spectroscopic effects have been interpreted in terms of molecule structure and configuration. The factors being responsible for the value of spectroscopic effects have been discussed

  1. A Discovery-Based Hydrochlorination of Carvone Utilizing a Guided-Inquiry Approach to Determine the Product Structure from [superscript 13]C NMR Spectra

    Science.gov (United States)

    Pelter, Michael W.; Walker, Natalie M.

    2012-01-01

    This experiment describes a discovery-based method for the regio- and stereoselective hydrochlorination of carvone, appropriate for a 3-h second-semester organic chemistry laboratory. The product is identified through interpretation of the [superscript 13]C NMR and DEPT spectra are obtained on an Anasazi EFT-60 at 15 MHz as neat samples. A…

  2. Theoretical Investigation on the Molecular Structure, Vibrational and NMR Spectra of N, N, 4-Tri chlorobenzenesulfonamide

    International Nuclear Information System (INIS)

    Cinar, M.

    2008-01-01

    In the present study, the structural properties of N,N,4-Tri chlorobenzenesulfonamide have been studied extensively using Density Functional Theory (DFT) employing B3LYP exchange correlation. The geometry of the molecule was fully optimized, vibrational spectrum was calculated and fundamental vibrations were assigned based on the scaled theoretical wavenumbers. The 1 H and 13 C nuclear magnetic resonance (NMR) chemical shifts of the compound were calculated using the Gauge-Invariant Atomic Orbital (GIAO) method. To investigate the basis set effects, calculations were performed at the 6-31G(d,p), 6-311G(d,p), 6-31++G(d,p) and 6-311++G(d,p) levels. Finally, geometric parameters, vibrational bands and isotropic chemical shifts were compared with available experimental data of compound. The fully optimized geometry of the molecule was found to be consistent with the X-ray crystal structure. The observed and calculated frequencies and chemical shifts were found to be in very good agreement. The computed results appear that the basis set has slight effect on the molecular geometry of N,N,4-Tri chlorobenzenesulfonamide

  3. Conformational effects on Carbon-13 NMR spectra of half-cage alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Seidl, Peter Rudolf [Universidade Federal (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica; Carneiro, J. Walkimar de M. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Dept. de Quimica Geral e Inorganica; Tostes, Glauco R. [Universidade Federal do Norte Fluminense (UENSP). Campos dos Goytacazes, RJ (Brazil). Centro de Ciencias e Tecnologia; Pinto, Paulo S.S. [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Dept. de Engenharia Quimica; Costa, Valentim E.U.; Alifantes, Joao [Rio Grande do Sul Univ. (UFRGS), Porto Alegre (Brazil). Inst. de Quimica; Bernassau, Jean-Marie; Sizun, Philippe [SANOFI Recherche, Montpellier (France)

    1999-05-01

    Rotation around the carbon=oxygen bond of the hydroxyl group of half-cage alcohols affects bond lengths and angles as well as charge distribution on carbon and hydrogen atoms. As derivatives of half-cage compounds have played an important role in the investigation of several phenomena of interest in the interpretation of NMR parameters, we calculated carbon -13 chemical shift for the three conformers of half-cage alcohols that were investigated at the 6-31 G{sup *} level. GIAO chemical shifts for 1 A, 1 B and 1 C (C{sub 6}-C{sub 5}-O-H dihedral angles of respectively, -73.6 deg C, 64.8 deg C and 178.0 deg C) were calculated by HF/6-31 g (d)// B3 LYP/6-31 g (d) and by B3LYP/6-31 g (d)//B3LYP/6-31 g (d). Since the later gave better agreement with the published chemical shifts and correctly predicts the order of shifts for 2-exo-norbornol, the bicyclic analog of 1, we took these calculations as a basis for analysis of conformational effects.

  4. Comparison of PET and proton NMR imaging in the diagnosis of Alzheimer-type dementia

    International Nuclear Information System (INIS)

    Friedland, R.P.; Budinger, T.F.; Jagust, W.J.; Brant-Zawadzki, M.

    1985-01-01

    Despite recent advances in the understanding of the pathophysiology of Alzheimer's disease (AD), medical personnel remain unable to make the diagnosis noninvasively, except by exclusion. The more recently developed technique of positron emission tomography (PET) has been used with a labeled glucose analogue, ( 18 F)-2-fluoro-2-deoxy-D-glucose (FDG), to noninvasively study glucose metabolism in dementia. Specific regional alterations, particularly in the temporal-parietal cortex, have been found. Nuclear magnetic resonance (NMR) imaging is another powerful new technology that is beginning to be applied to dementia. The authors have compared the findings in PET studies using FDG with NMR imaging in two subjects with Alzheimer-type dementia

  5. Proton spectra from 800 MeV protons on selected nuclei. Progress report, January 1, 1979-December 31, 1979

    International Nuclear Information System (INIS)

    Stearns, R.L.

    1979-09-01

    The emission of protons from targets of 6 Li, Li, 12 C, 27 Al, 40 Ca, 51 V, 90 Zr, and Pb under bombardment from 800 MeV protons was studied using the high resolution proton spectrometer at the Los Alamos Meson Physics Facility. Laboratory scattering angles of 5, 7, 9, 11, 13, 15, 20, 25, and 30 0 were measured, with special emphasis on the quasi-free region. Outgoing momenta corresponding to the region of pion production were examined at 11 and 15 0 . Absolute cross sections derived by reference to known (p,p) scattering data at 800 MeV. The quasi-free scattering has been fit with a DWIA analysis by summing over the unobserved (struck) nucleon. The systematics of proton production and the applicability of the DWIA analyses are discussed. 26 references

  6. Communication: Permanent dipoles contribute to electric polarization in chiral NMR spectra

    International Nuclear Information System (INIS)

    Buckingham, A. David

    2014-01-01

    Nuclear magnetic resonance spectroscopy is blind to chirality because the spectra of a molecule and its mirror image are identical unless the environment is chiral. However, precessing nuclear magnetic moments in chiral molecules in a strong magnetic field induce an electric polarization through the nuclear magnetic shielding polarizability. This effect is equal and opposite for a molecule and its mirror image but is small and has not yet been observed. It is shown that the permanent electric dipole moment of a chiral molecule is partially oriented through the antisymmetric part of the nuclear magnetic shielding tensor, causing the electric dipole to precess with the nuclear magnetic moment and producing a much larger temperature-dependent electric polarization with better prospects of detection

  7. Measurement of very forward neutron energy spectra for 7 TeV proton--proton collisions at the Large Hadron Collider

    CERN Document Server

    Adriani, O.; Bonechi, L.; Bongi, M.; Castellini, G.; D'Alessandro, R.; Del Prete, M.; Haguenauer, M.; Itow, Y.; Kasahara, K.; Kawade, K.; Makino, Y.; Masuda, K.; Matsubayashi, E.; Menjo, H.; Mitsuka, G.; Muraki, Y.; Okuno, Y.; Papini, P.; Perrot, A-L.; Ricciarini, S.; Sako, T.; Sakurai, N.; Sugiura, Y.; Suzuki, T.; Tamura, T.; Tiberio, A.; Torii, S.; Tricomi, A.; Turner, W.C.; Zhou, Q.D.

    2015-01-01

    The Large Hadron Collider forward (LHCf) experiment is designed to use the LHC to verify the hadronic-interaction models used in cosmic-ray physics. Forward baryon production is one of the crucial points to understand the development of cosmic-ray showers. We report the neutron-energy spectra for LHC $\\sqrt{s}$ = 7 TeV proton--proton collisions with the pseudo-rapidity $\\eta$ ranging from 8.81 to 8.99, from 8.99 to 9.22, and from 10.76 to infinity. The measured energy spectra obtained from the two independent calorimeters of Arm1 and Arm2 show the same characteristic feature before unfolding the difference in the detector responses. We unfolded the measured spectra by using the multidimensional unfolding method based on Bayesian theory, and the unfolded spectra were compared with current hadronic-interaction models. The QGSJET II-03 model predicts a high neutron production rate at the highest pseudo-rapidity range similar to our results and the DPMJET 3.04 model describes our results well at the lower pseudo-...

  8. 1H, 13C and 13N chemical shifts and 1H-15N and 13C-15N heteronuclear spin-spin coupling constants n the NMR spectra of 5-substituted furfural oximes

    International Nuclear Information System (INIS)

    Popelis, Yu.Yu.; Liepin'sh, E.E.; Lukevits, E.Ya.

    1986-01-01

    The 1 H, 13 C, and 15 N NMR spectra of 15 N-enriched 5-substituted furfural oximes were investigated. It was shown that the chemical shifts of the ring atoms and the oxime group correlate satisfactorily with the F and R substituent constants, whereas their sensitivity to the effect of the substituents is lower than in monosubstituted furan derivatives. The constants of spin-spin coupling between the ring protons and the oxime group were determined. An analysis of the 1 H- 1 H spin-spin coupling constants (SSCC) on the basis of their stereospecificity indicates that the E isomers have primarily an s-trans conformation in polar dimethyl sulfoxide, whereas the Z isomers, on the other hand, have an s-cis conformation. The signs of the direct and geminal 13 C- 15 N SSCC were determined for 5-trimethylsilylfurfural oxime

  9. Positional enrichment by proton analysis (PEPA). A one-dimensional "1H-NMR approach for "1"3C stable isotope tracer studies in metabolomics

    International Nuclear Information System (INIS)

    Vinaixa, Maria; Yanes, Oscar; Rodriguez, Miguel A.; Capellades, Jordi; Aivio, Suvi; Stracker, Travis H.; Gomez, Josep; Canyellas, Nicolau

    2017-01-01

    A novel metabolomics approach for NMR-based stable isotope tracer studies called PEPA is presented, and its performance validated using human cancer cells. PEPA detects the position of carbon label in isotopically enriched metabolites and quantifies fractional enrichment by indirect determination of "1"3C-satellite peaks using 1D-"1H-NMR spectra. In comparison with "1"3C-NMR, TOCSY and HSQC, PEPA improves sensitivity, accelerates the elucidation of "1"3C positions in labeled metabolites and the quantification of the percentage of stable isotope enrichment. Altogether, PEPA provides a novel framework for extending the high-throughput of "1H-NMR metabolic profiling to stable isotope tracing in metabolomics, facilitating and complementing the information derived from 2D-NMR experiments and expanding the range of isotopically enriched metabolites detected in cellular extracts. (copyright 2017 The Authors. Published by Wiley-VCH Verlag GmbH and Co. KGaA.)

  10. Positional enrichment by proton analysis (PEPA). A one-dimensional {sup 1}H-NMR approach for {sup 13}C stable isotope tracer studies in metabolomics

    Energy Technology Data Exchange (ETDEWEB)

    Vinaixa, Maria; Yanes, Oscar [Department of Electronic Engineering-Universitat Rovira i Virgili, Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Reus (Spain); Rodriguez, Miguel A.; Capellades, Jordi [Universitat Rovira i Virgili, Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Reus (Spain); Aivio, Suvi; Stracker, Travis H. [Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (Spain); Gomez, Josep; Canyellas, Nicolau [Department of Electronic Engineering-, Universitat Rovira i Virgili, Tarragona (Spain)

    2017-03-20

    A novel metabolomics approach for NMR-based stable isotope tracer studies called PEPA is presented, and its performance validated using human cancer cells. PEPA detects the position of carbon label in isotopically enriched metabolites and quantifies fractional enrichment by indirect determination of {sup 13}C-satellite peaks using 1D-{sup 1}H-NMR spectra. In comparison with {sup 13}C-NMR, TOCSY and HSQC, PEPA improves sensitivity, accelerates the elucidation of {sup 13}C positions in labeled metabolites and the quantification of the percentage of stable isotope enrichment. Altogether, PEPA provides a novel framework for extending the high-throughput of {sup 1}H-NMR metabolic profiling to stable isotope tracing in metabolomics, facilitating and complementing the information derived from 2D-NMR experiments and expanding the range of isotopically enriched metabolites detected in cellular extracts. (copyright 2017 The Authors. Published by Wiley-VCH Verlag GmbH and Co. KGaA.)

  11. A proton NMR study of the effect of Mucuna pruriens on seminal plasma metabolites of infertile males.

    Science.gov (United States)

    Gupta, Ashish; Mahdi, Abbas Ali; Ahmad, Mohammad Kaleem; Shukla, Kamla Kant; Bansal, Navneeta; Jaiswer, Shyam Pyari; Shankhwar, Satya Narain

    2011-07-15

    The objective of this study was to employ proton nuclear magnetic resonance ((1)H NMR) spectroscopy to evaluate the impact of Mucuna pruriens seeds on the metabolic profile of seminal plasma of infertile patients. A total of 180 infertile patients were administered M. pruriens seed powder for a period of three months. Age-matched healthy men comprised the control (n=50) group in the study. Lactate, alanine, choline, citrate, glycerophosphocholine (GPC), glutamine, tyrosine, histidine, phenylalanine, and uridine were measured in seminal plasma by (1)H NMR spectroscopy. To evaluate the degree of infertility and extent of hormonal imbalance induced by this milieu, separate sperm concentration, motility, lipid peroxide in seminal plasma and LH, FSH, T, and PRL hormone concentration in serum were measured using standard laboratory methods and RIA, respectively, in the same subjects. M. pruriens therapy rectifies the perturbed alanine, citrate, GPC, histidine and phenylalanine content in seminal plasma and improves the semen quality of post-treated infertile men with compared to pre-treated. Concomitantly, clinical variables in seminal plasma and blood serum were also improved over post therapy in infertile men. On the basis of these observations, it may be proposed that M. pruriens seed powder not only reactivates the enzymatic activity of metabolic pathways and energy metabolism but also rejuvenates the harmonic balance of male reproductive hormones in infertile men. These findings open more opportunities for infertility treatment and management by improving semen quality. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Interaction of the Saccharomyces cerevisiae α-factor with phospholipid vesicles as revealed by proton and phosphorus NMR

    International Nuclear Information System (INIS)

    Jelicks, L.A.; Broido, M.S.; Becker, J.M.; Naider, F.R.

    1989-01-01

    Proton and phosphorus-31 nuclear magnetic resonance ( 1 H and 31 P NMR) studies of the interaction between a tridecapeptide pheromone, the α-factor of Saccharomyces cerevisiae, and sonicated lipid vesicles are reported. 31 P NMR studies demonstrate that there is interaction of the peptide with the phosphorus headgroups, and quasielastic light scattering (QLS) studies indicate that lipid vesicles increase in size upon addition of peptide. Previous solution (aqueous and DMSO) studies from this laboratory indicate that α-factor is highly flexible with only one long-lived identifiable structural feature, a type II β-turn spanning the central portion of the peptide. Two-dimensional (2D) 1 H nuclear Overhauser effect spectroscopy (NOESY) studies demonstrate a marked ordering of the peptide upon interaction with lipid, suggesting a compact N-terminus, in addition to a stabilized β-turn. In contrast to these results in both solution and lipid environment, Wakamatsu et al. proposed a lipid environment conformation, on the basis of one-dimensional transferred NOE studies in D 2 O, which does not include the β-turn

  13. Investigating the Dissolution Performance of Amorphous Solid Dispersions Using Magnetic Resonance Imaging and Proton NMR

    Directory of Open Access Journals (Sweden)

    Francesco Tres

    2015-09-01

    Full Text Available We have investigated the dissolution performance of amorphous solid dispersions of poorly water-soluble bicalutamide in a Kollidon VA64 polymeric matrix as a function of the drug loading (5% vs. 30% bicalutamide. A combined suite of state-of-the-art analytical techniques were employed to obtain a clear picture of the drug release, including an integrated magnetic resonance imaging UV-Vis flow cell system and 1H-NMR. Off-line 1H-NMR was used for the first time to simultaneously measure the dissolution profiles and rates of both the drug and the polymer from a solid dispersion. MRI and 1H-NMR data showed that the 5% drug loading compact erodes linearly, and that bicalutamide and Kollidon VA64 are released at approximately the same rate from the molecular dispersion. For the 30% extrudate, data indicated a slower water ingress into the compact which corresponds to a slower dissolution rate of both bicalutamide and Kollidon VA64.

  14. Accurate classification of brain gliomas by discriminate dictionary learning based on projective dictionary pair learning of proton magnetic resonance spectra.

    Science.gov (United States)

    Adebileje, Sikiru Afolabi; Ghasemi, Keyvan; Aiyelabegan, Hammed Tanimowo; Saligheh Rad, Hamidreza

    2017-04-01

    Proton magnetic resonance spectroscopy is a powerful noninvasive technique that complements the structural images of cMRI, which aids biomedical and clinical researches, by identifying and visualizing the compositions of various metabolites within the tissues of interest. However, accurate classification of proton magnetic resonance spectroscopy is still a challenging issue in clinics due to low signal-to-noise ratio, overlapping peaks of metabolites, and the presence of background macromolecules. This paper evaluates the performance of a discriminate dictionary learning classifiers based on projective dictionary pair learning method for brain gliomas proton magnetic resonance spectroscopy spectra classification task, and the result were compared with the sub-dictionary learning methods. The proton magnetic resonance spectroscopy data contain a total of 150 spectra (74 healthy, 23 grade II, 23 grade III, and 30 grade IV) from two databases. The datasets from both databases were first coupled together, followed by column normalization. The Kennard-Stone algorithm was used to split the datasets into its training and test sets. Performance comparison based on the overall accuracy, sensitivity, specificity, and precision was conducted. Based on the overall accuracy of our classification scheme, the dictionary pair learning method was found to outperform the sub-dictionary learning methods 97.78% compared with 68.89%, respectively. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  15. Infrared spectra of proton transfer complexes of the cycleanine alkaloid in solid state

    Science.gov (United States)

    Kasende, Okuma E.; de Waal, D.

    2003-01-01

    Proton transfer complexes obtained between the cycleanine alkaloid and hydrogen chloride, hydrogen bromide and nitric acids have been investigated by infrared spectroscopic technique between 4000 and 400 cm -1 in KBr. The vibrational perturbations brought about by proton transfer complex formation, discussed in terms of preferred site of interaction, show that the proton of the inorganic acids is transferred to cycleanine through one of its N sites.

  16. NMR spectroscopy of organic compounds of selenium and tellurium. Communication 8. Constants of spin-spin interaction of /sup 125/Te-/sup 1/o/sup 3/C in nmr spectra of unsaturated organtellurides

    Energy Technology Data Exchange (ETDEWEB)

    Kalabin, G.A.; Kushnarev, D.F.; Valeev, R.B. (Irkutskij Gosudarstvennyj Univ. (USSR))

    1981-06-01

    On the basis of /sup 13/C NMR spectra of a series of unsaturated and aromatic tellurium compounds the constants of spin-spin interaction (SSIC) (sup(1.2)J(Te, C)) are measured. A reliable linear relation between /sup 1/J(Te, C) and s-character of a carbon orbitale forming bond with tellurium is found. Correlation of straight SSIC of carbon with selenium and tellurium in isological compounds is established.

  17. Measurement of the transverse momentum spectra of weak vector bosons produced in proton-proton collisions at √s=8 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Khachatryan, V.; Sirunyan, A.M.; Tumasyan, A. [Yerevan Physics Institute, Yerevan (Armenia); Adam, W. [Institut für Hochenergiephysik der OeAW, Wien (Austria); Collaboration: The CMS collaboration; and others

    2017-02-20

    The transverse momentum spectra of weak vector bosons are measured in the CMS experiment at the LHC. The measurement uses a sample of proton-proton collisions at √s=8 TeV, collected during a special low-luminosity running that corresponds to an integrated luminosity of 18.4±0.5 pb{sup −1}. The production of W bosons is studied in both electron and muon decay modes, while the production of Z bosons is studied using only the dimuon decay channel. The ratios of W{sup −} to W{sup +} and Z to W differential cross sections are also measured. The measured differential cross sections and ratios are compared with theoretical predictions up to next-to-next leading order in QCD.

  18. Proton NMR study of the influence of heme vinyl groups on the formation of the isomeric forms of sulfmyoglobin

    International Nuclear Information System (INIS)

    Chatfield, M.J.; La Mar, G.N.; Balch, A.L.; Smith, K.M.; Parish, D.W.; LePage, T.J.

    1986-01-01

    The formation of sulfmyoglobin has been investigated for myoglobin reconstituted with hemins having vinyls replaced by hydrogens to determine the participation of the vinyl groups in the reaction processes. Green complexes are produced in all cases, proving that vinyls are not obligatory for the formation of sulfproteins. In the presence of the 4-vinyl group, the 1 H NMR spectra of the met-cyano derivatives indicate the formation of three green species; however, the most stable of these products is not formed in the absence of this group, confirming reaction of the 4-vinyl in this species. Two new red extractable sulfmyoglobin derivatives are formed in the absence of the 4-vinyl group. (Auth.)

  19. Microstructural Analysis of Carbonyl Signal in the 13C NMR Spectra of Methyl Methacrylate - n-Butyl Acrylate Copolymer

    International Nuclear Information System (INIS)

    Bujak, P.; Matlengiewicz, M.

    2005-01-01

    Microstructural information on acrylic copolymers, i.e. distribution of the comonomers along the macromolecular chain and their stereochemical arrangement (tacticity) can be derived from 13 C NMR, analyzing the splitting of their carbonyl signal. In the 100 MHz 13 C NMR spectrum of poly(methyl methacrylate-co-n-butyl acrylate), PMMA-nBA, the carbonyl signal at 174-178,5 ppm is clearly split into the lines of configurational-compositional pentads. This splitting is slightly different in different solvents, hence, recording of the same sample in different solvents may reveal differences important to correct assignment of individual sequences, since their probabilities (intensities) remain the same, while the chemical shift can vary in different solvents. If we would like to perform a complete analysis at this level we have to determine the distribution of 272 individual pentads. The outermost lines in the carbonyl signal of the copolymer can be assigned to the sequences of pure composition by simple comparison with the spectra of respective homopolymers. The rest of the inner lines cannot be easily attributed, therefore, a series of copolymer samples of different composition were synthesized in order to observe the different heterosequences, since depending on copolymer composition, different signals representing individual sequences, assume different relative intensities. To confirm the correctness of proposed attribution a simulation of the carbonyl signal can be performed. It is therefore necessary to know the intensities and positions of individual signals, representing individual compositional-configurational pentads. Calculation of the intensity of the lines can be performed assuming Bernoullian and/or Markov statistics, separately for compositional and configurational sequences and verifying the overall distribution of the individual probabilities. The position of the individual lines cannot be straightforwardly determined, therefore, we have adopted an

  20. Proton transfer and hydrogen bonding in the organic solid state: a combined XRD/XPS/ssNMR study of 17 organic acid-base complexes.

    Science.gov (United States)

    Stevens, Joanna S; Byard, Stephen J; Seaton, Colin C; Sadiq, Ghazala; Davey, Roger J; Schroeder, Sven L M

    2014-01-21

    The properties of nitrogen centres acting either as hydrogen-bond or Brønsted acceptors in solid molecular acid-base complexes have been probed by N 1s X-ray photoelectron spectroscopy (XPS) as well as (15)N solid-state nuclear magnetic resonance (ssNMR) spectroscopy and are interpreted with reference to local crystallographic structure information provided by X-ray diffraction (XRD). We have previously shown that the strong chemical shift of the N 1s binding energy associated with the protonation of nitrogen centres unequivocally distinguishes protonated (salt) from hydrogen-bonded (co-crystal) nitrogen species. This result is further supported by significant ssNMR shifts to low frequency, which occur with proton transfer from the acid to the base component. Generally, only minor chemical shifts occur upon co-crystal formation, unless a strong hydrogen bond is formed. CASTEP density functional theory (DFT) calculations of (15)N ssNMR isotropic chemical shifts correlate well with the experimental data, confirming that computational predictions of H-bond strengths and associated ssNMR chemical shifts allow the identification of salt and co-crystal structures (NMR crystallography). The excellent agreement between the conclusions drawn by XPS and the combined CASTEP/ssNMR investigations opens up a reliable avenue for local structure characterization in molecular systems even in the absence of crystal structure information, for example for non-crystalline or amorphous matter. The range of 17 different systems investigated in this study demonstrates the generic nature of this approach, which will be applicable to many other molecular materials in organic, physical, and materials chemistry.

  1. A Simple Approach for Obtaining High Resolution, High Sensitivity ¹H NMR Metabolite Spectra of Biofluids with Limited Mass Supply

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-11-01

    A simple approach is reported that yields high resolution, high sensitivity ¹H NMR spectra of biofluids with limited mass supply. This is achieved by spinning a capillary sample tube containing a biofluid at the magic angle at a frequency of about 80Hz. A 2D pulse sequence called ¹H PASS is then used to produce a high-resolution ¹H NMR spectrum that is free from magnetic susceptibility induced line broadening. With this new approach a high resolution ¹H NMR spectrum of biofluids with a volume less than 1.0 µl can be easily achieved at a magnetic field strength as low as 7.05T. Furthermore, the methodology facilitates easy sample handling, i.e., the samples can be directly collected into inexpensive and disposable capillary tubes at the site of collection and subsequently used for NMR measurements. In addition, slow magic angle spinning improves magnetic field shimming and is especially suitable for high throughput investigations. In this paper first results are shown obtained in a magnetic field of 7.05T on urine samples collected from mice using a modified commercial NMR probe.

  2. Anomalous H/D isotope effect on 35Cl NQR frequencies and H/D isotope effect on 1H MAS NMR spectra in pyrrolidinium p-chlorobenzoate

    International Nuclear Information System (INIS)

    Nakano, Ryo; Honda, Hisashi; Nakata, Eiichi; Takamizawa, Satoshi; Noro, Sumiko; Kimura, Taiki; Kyo, Shin-shin; Ishimaru, Shin'ichi; Miyake, Ryosuke

    2010-01-01

    An anomalous isotope effect was observed in the 35 Cl NQR frequency of pyrrolidinium p-chlorobenzoate (C 4 H 8 NH 2 + ·ClC 6 H 4 COO - ) by deuterium substitution of hydrogen atoms which form two kinds of N-H...O type hydrogen bonds. Large negative frequency shifts of the 35 Cl resonance lines, reaching 309 kHz at 77 K and 267 kHz at 293 K, were obtained upon deuteration, although the Cl atom in the molecule formed no hydrogen bonds in the crystal. 1 H MAS NMR lines showed significant changes by the deuterium substitution, while in contrast, small shifts of 13 C CP/MAS NMR signals were obtained. Our measurements of 1 H NMR spin-lattice relaxation times (T 1 ) suggested that the H/D isotope shifts detected from the 35 Cl NQR frequencies and 1 H NMR spectra are due to structural changes rather than molecular dynamics. Single-crystal X-ray diffraction measurements showed two remarkable H/D isotope differences in the molecular arrangements, (1) the N-H length along the crystallographic a axis became 1 pm shorter, and (2) the dihedral angle between benzene and the pyrrolidine ring changed by 1.1(2)deg upon deuteration. Using density functional theory estimations, the anomalous 35 Cl NQR frequency shifts and 1 H MAS NMR line-shape changes could be explained by the dihedral angle change rather than the N-H length difference. (author)

  3. Histidine side-chain dynamics and protonation monitored by C-13 CPMG NMR relaxation dispersion

    DEFF Research Database (Denmark)

    Hass, M. A. S.; Yilmaz, A.; Christensen, Hans Erik Mølager

    2009-01-01

    the chemical shift titration experiments, and the CPMG derived exchange rates agree with those obtained previously from N-15 backbone relaxation measurements. Compared to measurements of backbone nuclei, C-13(epsilon 1) dispersion provides a more direct method to monitor interchanging protonation states...... or other kinds of conformational changes of histidine side chains or their environment. Advantages and shortcomings of using the C-13(epsilon 1) dispersion experiments in combination with chemical shift titration experiments to obtain information on exchange dynamics of the histidine side chains...

  4. [Study of hydrogen bonds in the "catalytic triad" of trypsin by NMR spectra at 1H, 13C, and 15N nuclei].

    Science.gov (United States)

    Golubeb, N S; Gindin, V A; Ligaĭ, S S; Smirnov, S N

    1994-05-01

    The 1H and 13C NMR of trypsin stabilized by chemical modification with a hydrophilic polymer have been obtained in a wide range of pH (1.0-11.0). The spectral features referred to some nuclei of the "catalytic triad" have been identified using different NMR techniques as well as chemical modification with selective reagents. It was found that the monoprotonation of this system results in a quasi-symmetrical hydrogen bond formed between the basic groups which provided explanation for the discrepancies between the experimental findings obtained by different authors concerning the protonation site in this catalytic system. Simulation of the catalytic triad by a 15N-labelled low molecular model suggests that an increase in the OH-group acidity is unaccompanied by a discrete double proton transfer; however, a smooth shift of the bridging protons from one basic atom to another occurs with quasi-symmetrical hydrogen bonds formed in intermediate cases. On the basis of experimental data a new concept has been proposed for the mechanism of acid-base catalysis performed by pains of weak basic groups, such as His-Im and Asp(Glu)-COO- (pKa = 3-7) which are not capable of proton abstraction from alcoholic or water OH-groups (pKa > 13). The catalysis may consist in changing the charge densities on the reacting groups due to strong H-bonding and, on the other hand, in facilitating the free movement of a proton in the field of several basic atoms when going along the reaction coordinate. The energy of very strong hydrogen bonds thus formed diminishes the activation energy of the reaction.

  5. Heteronuclear three-dimensional NMR spectroscopy. Natural abundance 13C chemical shift editing of 1H-1H COSY spectra

    International Nuclear Information System (INIS)

    Fesik, S.W.; Gampe, R.T. Jr.; Zuiderweg, E.R.P.

    1989-01-01

    It has been demonstrated that heteronuclear 3D NMR spectroscopy can be effectively applied to small molecules with 13 C at natural abundance. A 78mM solution of the aminoglycoside, kanamycin A was used for this experiment. The heteronuclear 3D NMR spectroscopy is shown to be a useful method for resolving spectral overlap in all frequency domains. 10 refs., 2 figs

  6. Proton NMR for Measuring Quantum Level Crossing in the Magnetic Molecular Ring Fe10

    International Nuclear Information System (INIS)

    Julien, M.; Jang, Z.H.; Borsa, F.; Julien, M.; Lascialfari, A.; Borsa, F.; Horvatic, M.; Caneschi, A.; Gatteschi, D.

    1999-01-01

    The proton nuclear spin-lattice relaxation rate 1/T 1 has been measured as a function of temperature and magnetic field (up to 15thinspthinspT) in the molecular magnetic ring Fe 10 ( OCH 3 ) 20 (O 2 CCH 2 Cl) 10 (Fe10). Striking enhancement of 1/T 1 is observed around magnetic field values corresponding to a crossing between the ground state and the excited states of the molecule. We propose that this is due to a cross-relaxation effect between the nuclear Zeeman reservoir and the reservoir of the Zeeman levels of the molecule. This effect provides a powerful tool to investigate quantum dynamical phenomena at level crossing. copyright 1999 The American Physical Society

  7. Proton and alpha evaporation spectra in low energy 12C and 16O ...

    Indian Academy of Sciences (India)

    75 MeV. The spectra are compared with the statistical model calculations. The shapes of the calculated spectra are in agreement with experimental data except for the alpha spectrum in the 12C+93Nb reaction at 40 MeV. The observed evaporation bump is at ~2. MeV lower energy compared to the calculated one.

  8. Proton and alpha evaporation spectra in low energy 12 C and 16 O ...

    Indian Academy of Sciences (India)

    The spectra are compared with the statistical model calculations. The shapes of the calculated spectra are in agreement with experimental data except for the alpha spectrum in the 12C+93Nb reaction at 40 MeV. The observed evaporation bump is at ∼ 2 MeV lower energy compared to the calculated one. This discrepancy ...

  9. NMR studies on the mechanism of structural destabilization of the globular proteins and DNA by aliphatic alcohols

    International Nuclear Information System (INIS)

    Lubas, B.; Witman, B.; Wieniewska, T.; Soltysik, M.

    1977-01-01

    The concept that the mechanism of structural destabilization of the biologically active macromolecules by typical denaturing agents should find a reflection in the NMR spectra of the denaturants themselves has been followed by proton NMR for some aliphatic alcohols in the system containing the serum albumin of DNA. (author)

  10. Spallation Neutron Emission Spectra in Some Amphoter Target Nuclei by Proton Beam Up to 140 MeV Energy

    International Nuclear Information System (INIS)

    Yildirim, G.

    2008-01-01

    In the present study, the (p,xn) reaction neutron-emission spectra for some amphoter target nuclei as 27 A l, 64 Z n, 120 S n, and 208 P b were investigated up to 140 MeV incident proton energy. The pre-equilibrium calculations were calculated by using the hybrid model, the geometry dependent hybrid model, the full exciton model and the cascade exciton model. The reaction equilibrium component was calculated with a traditional compound nucleus model developed by Weisskopf Ewing. Calculation results have been discussed and compared with the available experimental data in literature

  11. Measurements of Neutron Spectra Produced from a Thick Iron Target Bombarded with 1.5-GeV Protons

    International Nuclear Information System (INIS)

    Meigo, Shin-ichiro; Shigyo, Nobuhiro; Iga, Kiminori; Iwamoto, Yosuke; Kitsuki, Hirohiko; Ishibashi, Kenji; Maehata, Keisuke; Arima, Hidehiko; Nakamoto, Tatsushi; Numajiri, Masaharu

    2005-01-01

    For validation of calculation codes that are employed in the design of accelerator facilities, spectra of neutrons produced from a thick iron target bombarded with 1.5-GeV protons were measured. The calculated results with NMTC/JAM were compared with the present experimental results. It is found that the NMTC/JAM generally shows good agreement with experiment. Furthermore, the calculation gives good agreement with the experiment for the energy region 20 to 80 MeV for iron, whereas the NMTC/JAM gives 50% of the experimental data for the heavy-nuclides such as lead and tungsten

  12. Measurements of neutron spectra produced from a thick iron target bombarded with 1.5 GeV protons

    International Nuclear Information System (INIS)

    Meigo, Shin-ichiro; Takada, Hiroshi

    2001-01-01

    For validation of calculation codes which are employed in the design of accelerator facilities, spectra of neutrons produced from a thick iron target bombarded with 1.5-GeV protons were measured. The calculated results with NMTC/JAM were compared with the present experimental results. It is found the NMTC/JAM generally shows in good agreement with experiment. Furthermore, the calculation gives good agreement with the experiment for the energy region 20-80 MeV, whereas the NMTC/JAM gives 50% of the experimental data for the heavy nuclide target such as lead and tungsten target. (author)

  13. Proton NMR investigation of heme pocket mobility in hemoglobin via hydrogen isotope exchange kinetics

    International Nuclear Information System (INIS)

    Han, K.

    1985-01-01

    Dynamic mobility of heme cavity, the active site of Hb, was investigated by analyzing the hydrogen isotope exchange kinetics of the proximal histidyl ring NH of various kinds of Hbs with the aid of the high field Fourier Transform 1 H NMR spectroscopy. The exchange reaction occurs faster in oxy or R-state Hb than in deoxy or T-state Hb and there exists a good correlation between the oxygen affinity of Hb and the heme pocket mobility reflected in the hydrogen exchange rate. The effect of pH on the exchange is dramatically different for the two subunits of Hb A. Studying the exchange characteristics of mutant Hbs and chemically modified Hbs not only showed the existence of three well-defined localized paths for transmission of conformational changes between different heme pockets through a 1 b 2 subunit interface, but also indicated that the heme pocket mobility is regulated by the quaternary state of Hb as well as by the ligation state of Hb. Finally, the effect of the quaternary state on the heme pocket mobility is separated from that of the ligation by following the exchange reactions in Hbs where only their quaternary structure transition can be achieved without changing their ligation states by adjusting experimental conditions such as adding inositol hexaphosphate

  14. pH-Dependent spin state population and 19F NMR chemical shift via remote ligand protonation in an iron(ii) complex.

    Science.gov (United States)

    Gaudette, Alexandra I; Thorarinsdottir, Agnes E; Harris, T David

    2017-11-30

    An Fe II complex that features a pH-dependent spin state population, by virtue of a variable ligand protonation state, is described. This behavior leads to a highly pH-dependent 19 F NMR chemical shift with a sensitivity of 13.9(5) ppm per pH unit at 37 °C, thereby demonstrating the potential utility of the complex as a 19 F chemical shift-based pH sensor.

  15. NMR imaging and pharmaceutical sciences

    International Nuclear Information System (INIS)

    Beall, P.T.; Good, W.R.

    1986-01-01

    Described is the technique of NMR-imaging in diagnostic medicine. Proton and phosphorus NMR in diagnosis of abnormal tissue pathology. Discussed is the value of NMR to the pharmaceutical sciences. NMR may play an important role in monitoring the response of tissues to drugs, determining the localization of drugs, performing real time pharmacokinetics and testing the use of NMR contrast pharmaceuticals

  16. Proton NMR Studies of a Large Protein. pH, Substrate Titrations, and NOESY Experiments with Perdeuterated Yeast Phosphoglycerate Kinase Containing [ 1H]Histidine Residues

    Science.gov (United States)

    Pappu, K. M.; Serpersu, E. H.

    Fully deuterated yeast phosphoglycerate kinase ([ 2H]PGK) was prepared biosynthetically with only histidine side chains of normal ( 1H) isotopic composition. The 1H NMR spectrum of this enzyme([ 1H]His[ 2H]PGK) showed that the histidine side chains are clearly visible as sharp signals. Thus detailed structural studies by 1H NMR became feasible with isotope-hybrid phosphoglycerate kinase which is otherwise too large ( Mr ˜ 46,000) for conventional 1H NMR studies. Proton signals of bound substrates were visible in the 1H NMR spectrum even with a substrate-to-enzyme ratio of less than 1/2 (mol/mol). The 2D NOESY spectrum of enzyme-MgdATP-glycerol 3-phosphate complex showed that, although protein concentration was very high (1.5 m M), no intraprotein cross peaks were observed other than those of intraresidue histidine NOE cross peaks. In addition, intrasubstrate NOEs and intermolecular NOEs between histidine and substrate protons were visible at a 1.5/1 substrate/enzyme (mol/mol) ratio. Paramagnetic effects of a substrate analog, Cr(III)ATP, on some of the histidine side chains indicated that the formation of the ternary enzyme-substrate complex causes large conformational changes in the enzyme.

  17. Characterization of pH titration shifts for all the nonlabile proton resonances in a protein by two-dimensional NMR: The case of mouse epidermal growth factor

    International Nuclear Information System (INIS)

    Kohda, Daisuke; Sawada, Toshie; Inagaki, Fuyuhiko

    1991-01-01

    The pH titration shifts for all the nonlabile proton resonances in a 53-residue protein (mouse epidermal growth factor) were measured in the p 2 H range 1.5-9 with two-dimensional (2D) 1 H NMR. The 2D NMR pH titration experiment made it possible to determine the pK values for all the ionizable group which were titrated in the pH range 1.5-9 in the protein. The pK values of the nine ionizable groups (α-amino group, four Asp, two Glu, one His, and α-carboxyl group) were found to be near their normal values. The 2D titration experiment also provided a detailed description of the pH-dependent behavior of the proton chemical shifts and enabled us to characterize the pH-dependent changes of protein conformation. Analysis of the pH-dependent shifts of ca. 200 proton resonances offered evidence of conformational changes in slightly basic pH solution: The deprotonation of the N-terminal α-amino group induced a widespread conformational change over the β-sheet structure in the protein, while the effects of deprotonation of the His22 imidazole group were relatively localized. The authors found that the 2D NMR pH titration experiment is a powerful tool for investigating the structural and dynamic properties of proteins

  18. The effects of bone on proton NMR relaxation times of surrounding liquids

    Science.gov (United States)

    Davis, C. A.; Genant, H. K.; Dunham, J. S.

    1986-01-01

    Preliminary attempts by our group at UCSF to assess fat content of vertebral marrow in the lumbar spine using relaxation time information demonstrated that the presence of trabecular bone affects relaxation times. The objective of this work was a thorough study of the effects of bone on NMR relaxation characteristics of surrounding liquids. Trabecular bone from autopsy specimens was ground up and sifted into a series of powders with graded densities ranging from 0.3 gm/cc to 0.8 gm/cc. Each powder was placed first in n-saline and then in cottonseed oil. With spectroscopy, spin-lattice relaxation times (T1) and effective spin-spin relaxation times (T2*) were measured for each liquid in each bone powder. As bone density and surface to volume ratio increased, T1 decreased faster for saline than for oil. T2* decreased significantly for both water and oil as the surface to volume ratio increased. It was concluded that effects of water on T1 could be explained by a surface interaction at the bone/liquid interface, which restricted rotational and translational motion of nearby molecules. The T1s of oil were not affected since oil molecules are nonpolar, do not participate in significant intermolecular hydrogen bonding, and therefore would not be expected to interact strongly with the bone surface. Effects on T2* could be explained by local magnetic field inhomogeneities created by discontinuous magnetic susceptibility near the bone surface. These preliminary results suggest that water in contact with trabecular bone in vivo will exhibit shortened relaxation times.

  19. Inclusive proton spectra and total reaction cross sections for proton-nucleus scattering at 800 MeV

    International Nuclear Information System (INIS)

    McGill, J.A.

    1981-08-01

    Current applications of multiple scattering theory to describe the elastic scattering of medium energy protons from nuclei have been shown to be quite successful in reproducing the experimental cross sections. These calculations use the impulse approximation, wherein the scattering from individual nucleons in the nucleus is described by the scattering amplitude for a free nucleon. Such an approximation restricts the inelastic channels to those initiated by nucleon-nucleon scattering. As a first step in determining the nature of p + nucleus scattering at 800 MeV, both total reaction cross sections and (p,p') inclusive cross sections were measured and compared to the free p + p cross sections for hydrogen, deuterium, calcium 40, carbon 12, and lead 208. It is concluded that as much as 85% of all reactions in a nucleus proceed from interactions with a single nucleon in the nucleus, and that the impulse approximation is a good starting point for a microscopic description of p + nucleus interactions at 800 MeV

  20. On unfolding counting-rate spectra of recoil-proton neutron detectors

    International Nuclear Information System (INIS)

    Yeivin, Yehuda

    1983-01-01

    This note proposes a possible scheme for unfolding recoil-proton neutron detector data, in which at first the undistorted proton source spectrum is derived. The main argument in favour of this scheme is that, compared with the conventional scheme, it necessitates somewhat weaker assumptions with respect to the unknown spectrum above the detector's upper energy cutoff, and would therefore be more reliable. We also demonstrate a simple, elementary proof of the wall effect correction for spherical detectors, and, in order to gain insight of the potential merits of the proposed unfolding scheme, illustrate our main argument by considering a hypothetic linear range-energy relation, in which case complete unfolding becomes possible with no assumptions at all on the proton spectrum above the cutoff energy. (author)

  1. Determination of proton and neutron spectra in the LANSCE spallation irradiation facility

    International Nuclear Information System (INIS)

    James, M.R.; Maloy, S.A.; Sommer, W.F.; Fowler, M.M.; Dry, D.; Ferguson, P.D.; Mueller, G.; Corzine, R.K.

    1999-01-01

    Materials samples were recently irradiated in the Los Alamos Radiation Effects Facility (LASREF) at the Los Alamos Neutron Science Center (LANSCE) to provide data for the Accelerator Production of Tritium (APT) project on the effect of irradiation on the mechanical and physical properties of materials. The targets were configured to expose samples to a variety of radiation environments including, high-energy protons, mixed protons and high-energy neutrons, and low-energy neutrons. The samples were irradiated for approximately six months during a ten month period using an 800 MeV proton beam with a circular Gaussian shape of approximately 2σ = 3.0 cm. At the end of this period, the samples were extracted and tested. Activation foils were also extracted that had been placed in proximity to the materials samples. These were used to quantify the fluences in various locations

  2. Proton Environments in Biomimetic Calcium Phosphates Formed from Mesoporous Bioactive CaO-SiO2-P2O5 Glasses in Vitro: Insights from Solid-State NMR.

    Science.gov (United States)

    Mathew, Renny; Turdean-Ionescu, Claudia; Yu, Yang; Stevensson, Baltzar; Izquierdo-Barba, Isabel; García, Ana; Arcos, Daniel; Vallet-Regí, María; Edén, Mattias

    2017-06-22

    When exposed to body fluids, mesoporous bioactive glasses (MBGs) of the CaO-SiO 2 -P 2 O 5 system develop a bone-bonding surface layer that initially consists of amorphous calcium phosphate (ACP), which transforms into hydroxy-carbonate apatite (HCA) with a very similar composition as bone/dentin mineral. Information from various 1 H-based solid-state nuclear magnetic resonance (NMR) experiments was combined to elucidate the evolution of the proton speciations both at the MBG surface and within each ACP/HCA constituent of the biomimetic phosphate layer formed when each of three MBGs with distinct Ca, Si, and P contents was immersed in a simulated body fluid (SBF) for variable periods between 15 min and 30 days. Directly excited magic-angle-spinning (MAS) 1 H NMR spectra mainly reflect the MBG component, whose surface is rich in water and silanol (SiOH) moieties. Double-quantum-single-quantum correlation 1 H NMR experimentation at fast MAS revealed their interatomic proximities. The comparatively minor H species of each ACP and HCA component were probed selectively by heteronuclear 1 H- 31 P NMR experimentation. The initially prevailing ACP phase comprises H 2 O and "nonapatitic" HPO 4 2- /PO 4 3- groups, whereas for prolonged MBG soaking over days, a well-progressed ACP → HCA transformation was evidenced by a dominating O 1 H resonance from HCA. We show that 1 H-detected 1 H → 31 P cross-polarization NMR is markedly more sensitive than utilizing powder X-ray diffraction or 31 P NMR for detecting the onset of HCA formation, notably so for P-bearing (M)BGs. In relation to the long-standing controversy as to whether bone mineral comprises ACP and/or forms via an ACP precursor, we discuss a recently accepted structural core-shell picture of both synthetic and biological HCA, highlighting the close relationship between the disordered surface layer and ACP.

  3. Study of inclusive proton spectra from 20 MeV deuteron breakup by bismuth

    International Nuclear Information System (INIS)

    Badiger, N.M.; Hallur, B.R.; Madhusoodhanan, T.; Sathyavathiamma, M.P.; Puttaswamy, N.G.; Darshan, V.P.; Sharma, H.; Chintalapudi, S.N.

    1997-01-01

    The breakup of deuteron into proton and neutron has been studied earlier to understand the breakup mechanism. Inclusive measurements show the expected broad bumps near the beam velocity. In the present experiment, the breakup of 20 MeV deuterons by bismuth target has been investigated

  4. NMR-based approach to the analysis of radiopharmaceuticals: radiochemical purity, specific activity, and radioactive concentration values by proton and tritium NMR spectroscopy.

    Science.gov (United States)

    Schenk, David J; Dormer, Peter G; Hesk, David; Pollack, Scott R; Lavey, Carolee Flader

    2015-06-15

    Compounds containing tritium are widely used across the drug discovery and development landscape. These materials are widely utilized because they can be efficiently synthesized and produced at high specific activity. Results from internally calibrated (3)H and (1)H nuclear magnetic resonance (NMR) spectroscopy suggests that at least in some cases, this calibrated approach could supplement or potentially replace radio-high-performance liquid chromatography for radiochemical purity, dilution and scintillation counting for the measurement of radioactivity per volume, and liquid chromatography/mass spectrometry analysis for the determination of specific activity. In summary, the NMR-derived values agreed with those from the standard approaches to within 1% to 9% for solution count and specific activity. Additionally, the NMR-derived values for radiochemical purity deviated by less than 5%. A benefit of this method is that these values may be calculated at the same time that (3)H NMR analysis provides the location and distribution of tritium atoms within the molecule. Presented and discussed here is the application of this method, advantages and disadvantages of the approach, and a rationale for utilizing internally calibrated (1)H and (3)H NMR spectroscopy for specific activity, radioactive concentration, and radiochemical purity whenever acquiring (3)H NMR for tritium location. Copyright © 2015 John Wiley & Sons, Ltd.

  5. Search for physics beyond the standard model in dilepton mass spectra in proton-proton collisions at $\\sqrt{s}$ = 8 TeV

    CERN Document Server

    Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Bergauer, Thomas; Dragicevic, Marko; Erö, Janos; Fabjan, Christian; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; Kiesenhofer, Wolfgang; Knünz, Valentin; Krammer, Manfred; Krätschmer, Ilse; Liko, Dietrich; Mikulec, Ivan; Rabady, Dinyar; Rahbaran, Babak; Rohringer, Herbert; Schöfbeck, Robert; Strauss, Josef; Taurok, Anton; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; Bansal, Monika; Bansal, Sunil; Cornelis, Tom; De Wolf, Eddi A; Janssen, Xavier; Knutsson, Albert; Luyckx, Sten; Ochesanu, Silvia; Rougny, Romain; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Blekman, Freya; Blyweert, Stijn; D'Hondt, Jorgen; Daci, Nadir; Heracleous, Natalie; Keaveney, James; Lowette, Steven; Maes, Michael; Olbrechts, Annik; Python, Quentin; Strom, Derek; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Onsem, Gerrit Patrick; Villella, Ilaria; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Dobur, Didar; Favart, Laurent; Gay, Arnaud; Grebenyuk, Anastasia; Léonard, Alexandre; Mohammadi, Abdollah; Perniè, Luca; Reis, Thomas; Seva, Tomislav; Thomas, Laurent; Vander Velde, Catherine; Vanlaer, Pascal; Wang, Jian; Zenoni, Florian; Adler, Volker; Beernaert, Kelly; Benucci, Leonardo; Cimmino, Anna; Costantini, Silvia; Crucy, Shannon; Dildick, Sven; Fagot, Alexis; Garcia, Guillaume; Mccartin, Joseph; Ocampo Rios, Alberto Andres; Ryckbosch, Dirk; Salva Diblen, Sinem; Sigamani, Michael; Strobbe, Nadja; Thyssen, Filip; Tytgat, Michael; Yazgan, Efe; Zaganidis, Nicolas; Basegmez, Suzan; Beluffi, Camille; Bruno, Giacomo; Castello, Roberto; Caudron, Adrien; Ceard, Ludivine; Da Silveira, Gustavo Gil; Delaere, Christophe; Du Pree, Tristan; Favart, Denis; Forthomme, Laurent; Giammanco, Andrea; Hollar, Jonathan; Jafari, Abideh; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Nuttens, Claude; Pagano, Davide; Perrini, Lucia; Pin, Arnaud; Piotrzkowski, Krzysztof; Popov, Andrey; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Vizan Garcia, Jesus Manuel; Beliy, Nikita; Caebergs, Thierry; Daubie, Evelyne; Hammad, Gregory Habib; Aldá Júnior, Walter Luiz; Alves, Gilvan; Brito, Lucas; Correa Martins Junior, Marcos; Dos Reis Martins, Thiago; Mora Herrera, Clemencia; Pol, Maria Elena; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Melo Da Costa, Eliza; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Malbouisson, Helena; Matos Figueiredo, Diego; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santaolalla, Javier; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Bernardes, Cesar Augusto; Dogra, Sunil; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Novaes, Sergio F; Padula, Sandra; Aleksandrov, Aleksandar; Genchev, Vladimir; Iaydjiev, Plamen; Marinov, Andrey; Piperov, Stefan; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Hadjiiska, Roumyana; Kozhuharov, Venelin; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Du, Ran; Jiang, Chun-Hua; Plestina, Roko; Romeo, Francesco; Tao, Junquan; Wang, Zheng; Asawatangtrakuldee, Chayanit; Ban, Yong; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Zou, Wei; Avila, Carlos; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; Gomez Moreno, Bernardo; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Polic, Dunja; Puljak, Ivica; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Kadija, Kreso; Luetic, Jelena; Mekterovic, Darko; Sudic, Lucija; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Bodlak, Martin; Finger, Miroslav; Finger Jr, Michael; Assran, Yasser; Elgammal, Sherif; Mahmoud, Mohammed; Radi, Amr; Kadastik, Mario; Murumaa, Marion; Raidal, Martti; Tiko, Andres; Eerola, Paula; Fedi, Giacomo; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Kortelainen, Matti J; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Mäenpää, Teppo; Peltola, Timo; Tuominen, Eija; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Talvitie, Joonas; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Locci, Elizabeth; Malcles, Julie; Rander, John; Rosowsky, André; Titov, Maksym; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Charlot, Claude; Dahms, Torsten; Dalchenko, Mykhailo; Dobrzynski, Ludwik; Filipovic, Nicolas; Florent, Alice; Granier de Cassagnac, Raphael; Mastrolorenzo, Luca; Miné, Philippe; Mironov, Camelia; Naranjo, Ivo Nicolas; Nguyen, Matthew; Ochando, Christophe; Paganini, Pascal; Regnard, Simon; Salerno, Roberto; Sauvan, Jean-Baptiste; Sirois, Yves; Veelken, Christian; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Aubin, Alexandre; Bloch, Daniel; Brom, Jean-Marie; Chabert, Eric Christian; Collard, Caroline; Conte, Eric; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Goetzmann, Christophe; Le Bihan, Anne-Catherine; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Beaupere, Nicolas; Boudoul, Gaelle; Bouvier, Elvire; Brochet, Sébastien; Carrillo Montoya, Camilo Andres; Chasserat, Julien; Chierici, Roberto; Contardo, Didier; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Ille, Bernard; Kurca, Tibor; Lethuillier, Morgan; Mirabito, Laurent; Perries, Stephane; Ruiz Alvarez, José David; Sabes, David; Sgandurra, Louis; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Xiao, Hong; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Bontenackels, Michael; Edelhoff, Matthias; Feld, Lutz; Hindrichs, Otto; Klein, Katja; Ostapchuk, Andrey; Perieanu, Adrian; Raupach, Frank; Sammet, Jan; Schael, Stefan; Weber, Hendrik; Wittmer, Bruno; Zhukov, Valery; Ata, Metin; Brodski, Michael; Dietz-Laursonn, Erik; Duchardt, Deborah; Erdmann, Martin; Fischer, Robert; Güth, Andreas; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Klingebiel, Dennis; Knutzen, Simon; Kreuzer, Peter; Merschmeyer, Markus; Meyer, Arnd; Millet, Philipp; Olschewski, Mark; Padeken, Klaas; Papacz, Paul; Pook, Tobias; Reithler, Hans; Schmitz, Stefan Antonius; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Weber, Martin; Cherepanov, Vladimir; Erdogan, Yusuf; Flügge, Günter; Geenen, Heiko; Geisler, Matthias; Haj Ahmad, Wael; Heister, Arno; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Kuessel, Yvonne; Künsken, Andreas; Lingemann, Joschka; Nowack, Andreas; Nugent, Ian Michael; Perchalla, Lars; Pooth, Oliver; Stahl, Achim; Asin, Ivan; Bartosik, Nazar; Behr, Joerg; Behrenhoff, Wolf; Behrens, Ulf; Bell, Alan James; Bergholz, Matthias; Bethani, Agni; Borras, Kerstin; Burgmeier, Armin; Cakir, Altan; Calligaris, Luigi; Campbell, Alan; Choudhury, Somnath; Costanza, Francesco; Diez Pardos, Carmen; Dooling, Samantha; Dorland, Tyler; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Flucke, Gero; Garay Garcia, Jasone; Geiser, Achim; Gunnellini, Paolo; Hauk, Johannes; Hempel, Maria; Horton, Dean; Jung, Hannes; Kalogeropoulos, Alexis; Kasemann, Matthias; Katsas, Panagiotis; Kieseler, Jan; Kleinwort, Claus; Krücker, Dirk; Lange, Wolfgang; Leonard, Jessica; Lipka, Katerina; Lobanov, Artur; Lohmann, Wolfgang; Lutz, Benjamin; Mankel, Rainer; Marfin, Ihar; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mittag, Gregor; Mnich, Joachim; Mussgiller, Andreas; Naumann-Emme, Sebastian; Nayak, Aruna; Novgorodova, Olga; Ntomari, Eleni; Perrey, Hanno; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Ribeiro Cipriano, Pedro M; Roland, Benoit; Ron, Elias; Sahin, Mehmet Özgür; Salfeld-Nebgen, Jakob; Saxena, Pooja; Schmidt, Ringo; Schoerner-Sadenius, Thomas; Schröder, Matthias; Seitz, Claudia; Spannagel, Simon; Vargas Trevino, Andrea Del Rocio; Walsh, Roberval; Wissing, Christoph; Aldaya Martin, Maria; Blobel, Volker; Centis Vignali, Matteo; Draeger, Arne-Rasmus; Erfle, Joachim; Garutti, Erika; Goebel, Kristin; Görner, Martin; Haller, Johannes; Hoffmann, Malte; Höing, Rebekka Sophie; Kirschenmann, Henning; Klanner, Robert; Kogler, Roman; Lange, Jörn; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Ott, Jochen; Peiffer, Thomas; Pietsch, Niklas; Poehlsen, Jennifer; Pöhlsen, Thomas; Rathjens, Denis; Sander, Christian; Schettler, Hannes; Schleper, Peter; Schlieckau, Eike; Schmidt, Alexander; Seidel, Markus; Sola, Valentina; Stadie, Hartmut; Steinbrück, Georg; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Vanhoefer, Annika; Barth, Christian; Baus, Colin; Berger, Joram; Böser, Christian; Butz, Erik; Chwalek, Thorsten; De Boer, Wim; Descroix, Alexis; Dierlamm, Alexander; Feindt, Michael; Frensch, Felix; Giffels, Manuel; Hartmann, Frank; Hauth, Thomas; Husemann, Ulrich; Katkov, Igor; Kornmayer, Andreas; Kuznetsova, Ekaterina; Lobelle Pardo, Patricia; Mozer, Matthias Ulrich; Müller, Thomas; Nürnberg, Andreas; Quast, Gunter; Rabbertz, Klaus; Ratnikov, Fedor; Röcker, Steffen; Simonis, Hans-Jürgen; Stober, Fred-Markus Helmut; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weiler, Thomas; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Markou, Athanasios; Markou, Christos; Psallidas, Andreas; Topsis-Giotis, Iasonas; Agapitos, Antonis; Kesisoglou, Stilianos; Panagiotou, Apostolos; Saoulidou, Niki; Stiliaris, Efstathios; Aslanoglou, Xenofon; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Kokkas, Panagiotis; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Bencze, Gyorgy; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Molnar, Jozsef; Palinkas, Jozsef; Szillasi, Zoltan; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Swain, Sanjay Kumar; Beri, Suman Bala; Bhatnagar, Vipin; Gupta, Ruchi; Bhawandeep, Bhawandeep; Kalsi, Amandeep Kaur; Kaur, Manjit; Kumar, Ramandeep; Mittal, Monika; Nishu, Nishu; Singh, Jasbir; Kumar, Ashok; Kumar, Arun; Ahuja, Sudha; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Kumar, Ajay; Malhotra, Shivali; Naimuddin, Md; Ranjan, Kirti; Sharma, Varun; Banerjee, Sunanda; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dutta, Suchandra; Gomber, Bhawna; Jain, Sandhya; Jain, Shilpi; Khurana, Raman; Modak, Atanu; Mukherjee, Swagata; Roy, Debarati; Sarkar, Subir; Sharan, Manoj; Abdulsalam, Abdulla; Dutta, Dipanwita; Kailas, Swaminathan; Kumar, Vineet; Mohanty, Ajit Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Banerjee, Sudeshna; Bhowmik, Sandeep; Chatterjee, Rajdeep Mohan; Dewanjee, Ram Krishna; Dugad, Shashikant; Ganguly, Sanmay; Ghosh, Saranya; Guchait, Monoranjan; Gurtu, Atul; Kole, Gouranga; Kumar, Sanjeev; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Mohanty, Gagan Bihari; Parida, Bibhuti; Sudhakar, Katta; Wickramage, Nadeesha; Bakhshiansohi, Hamed; Behnamian, Hadi; Etesami, Seyed Mohsen; Fahim, Ali; Goldouzian, Reza; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Rezaei Hosseinabadi, Ferdos; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Barbone, Lucia; Calabria, Cesare; Chhibra, Simranjit Singh; Colaleo, Anna; Creanza, Donato; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Selvaggi, Giovanna; Sharma, Archana; Silvestris, Lucia; Venditti, Rosamaria; Zito, Giuseppe; Abbiendi, Giovanni; Benvenuti, Alberto; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Primavera, Federica; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Travaglini, Riccardo; Albergo, Sebastiano; Cappello, Gigi; Chiorboli, Massimiliano; Costa, Salvatore; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Gallo, Elisabetta; Gonzi, Sandro; Gori, Valentina; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Tropiano, Antonio; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Ferretti, Roberta; Ferro, Fabrizio; Lo Vetere, Maurizio; Robutti, Enrico; Tosi, Silvano; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Gerosa, Raffaele; Ghezzi, Alessio; Govoni, Pietro; Lucchini, Marco Toliman; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Martelli, Arabella; Marzocchi, Badder; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Ragazzi, Stefano; Redaelli, Nicola; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; Di Guida, Salvatore; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lista, Luca; Meola, Sabino; Merola, Mario; Paolucci, Pierluigi; Azzi, Patrizia; Bacchetta, Nicola; Bisello, Dario; Branca, Antonio; Carlin, Roberto; Checchia, Paolo; Dall'Osso, Martino; Dorigo, Tommaso; Dosselli, Umberto; Galanti, Mario; Gasparini, Fabrizio; Gasparini, Ugo; Giubilato, Piero; Gozzelino, Andrea; Kanishchev, Konstantin; Lacaprara, Stefano; Margoni, Martino; Meneguzzo, Anna Teresa; Pazzini, Jacopo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Tosi, Mia; Zotto, Pierluigi; Zucchetta, Alberto; Zumerle, Gianni; Gabusi, Michele; Ratti, Sergio P; Re, Valerio; Riccardi, Cristina; Salvini, Paola; Vitulo, Paolo; Biasini, Maurizio; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Mantovani, Giancarlo; Menichelli, Mauro; Saha, Anirban; Santocchia, Attilio; Spiezia, Aniello; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Broccolo, Giuseppe; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fiori, Francesco; Foà, Lorenzo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Moon, Chang-Seong; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Serban, Alin Titus; Spagnolo, Paolo; Squillacioti, Paola; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Vernieri, Caterina; Barone, Luciano; Cavallari, Francesca; D'imperio, Giulia; Del Re, Daniele; Diemoz, Marcella; Grassi, Marco; Jorda, Clara; Longo, Egidio; Margaroli, Fabrizio; Meridiani, Paolo; Micheli, Francesco; Nourbakhsh, Shervin; Organtini, Giovanni; Paramatti, Riccardo; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Soffi, Livia; Traczyk, Piotr; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Casasso, Stefano; Costa, Marco; Degano, Alessandro; Demaria, Natale; Finco, Linda; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Musich, Marco; Obertino, Maria Margherita; Ortona, Giacomo; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Potenza, Alberto; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Solano, Ada; Staiano, Amedeo; Tamponi, Umberto; Belforte, Stefano; Candelise, Vieri; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Gobbo, Benigno; La Licata, Chiara; Marone, Matteo; Schizzi, Andrea; Umer, Tomo; Zanetti, Anna; Chang, Sunghyun; Kropivnitskaya, Anna; Nam, Soon-Kwon; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Kong, Dae Jung; Lee, Sangeun; Oh, Young Do; Park, Hyangkyu; Sakharov, Alexandre; Son, Dong-Chul; Kim, Tae Jeong; Kim, Jae Yool; Song, Sanghyeon; Choi, Suyong; Gyun, Dooyeon; Hong, Byung-Sik; Jo, Mihee; Kim, Hyunchul; Kim, Yongsun; Lee, Byounghoon; Lee, Kyong Sei; Park, Sung Keun; Roh, Youn; Choi, Minkyoo; Kim, Ji Hyun; Park, Inkyu; Ryu, Geonmo; Ryu, Min Sang; Choi, Young-Il; Choi, Young Kyu; Goh, Junghwan; Kim, Donghyun; Kwon, Eunhyang; Lee, Jongseok; Seo, Hyunkwan; Yu, Intae; Juodagalvis, Andrius; Komaragiri, Jyothsna Rani; Md Ali, Mohd Adli Bin; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-de La Cruz, Ivan; Hernandez-Almada, Alberto; Lopez-Fernandez, Ricardo; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Vazquez Valencia, Fabiola; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Casimiro Linares, Edgar; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Reucroft, Steve; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Khalid, Shoaib; Khan, Wajid Ali; Khurshid, Taimoor; Shah, Mehar Ali; Shoaib, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Brona, Grzegorz; Bunkowski, Karol; Cwiok, Mikolaj; Dominik, Wojciech; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michał; Wolszczak, Weronika; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Lloret Iglesias, Lara; Nguyen, Federico; Rodrigues Antunes, Joao; Seixas, Joao; Varela, Joao; Vischia, Pietro; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Konoplyanikov, Viktor; Kozlov, Guennady; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Savina, Maria; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Zarubin, Anatoli; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Levchenko, Petr; Murzin, Victor; Oreshkin, Vadim; Smirnov, Igor; Sulimov, Valentin; Uvarov, Lev; Vavilov, Sergey; Vorobyev, Alexey; Vorobyev, Andrey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Safronov, Grigory; Semenov, Sergey; Spiridonov, Alexander; Stolin, Viatcheslav; Vlasov, Evgueni; Zhokin, Alexander; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Mesyats, Gennady; Rusakov, Sergey V; Vinogradov, Alexey; Belyaev, Andrey; Boos, Edouard; Bunichev, Viacheslav; Dubinin, Mikhail; Dudko, Lev; Gribushin, Andrey; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Obraztsov, Stepan; Perfilov, Maxim; Savrin, Viktor; Snigirev, Alexander; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Tourtchanovitch, Leonid; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Ekmedzic, Marko; Milosevic, Jovan; Rekovic, Vladimir; Alcaraz Maestre, Juan; Battilana, Carlo; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Domínguez Vázquez, Daniel; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Navarro De Martino, Eduardo; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Senghi Soares, Mara; Albajar, Carmen; de Trocóniz, Jorge F; Missiroli, Marino; Moran, Dermot; Brun, Hugues; Cuevas, Javier; Fernandez Menendez, Javier; Folgueras, Santiago; Gonzalez Caballero, Isidro; Brochero Cifuentes, Javier Andres; Cabrillo, Iban Jose; Calderon, Alicia; Duarte Campderros, Jordi; Fernandez, Marcos; Gomez, Gervasio; Graziano, Alberto; Lopez Virto, Amparo; Marco, Jesus; Marco, Rafael; Martinez Rivero, Celso; Matorras, Francisco; Munoz Sanchez, Francisca Javiela; Piedra Gomez, Jonatan; Rodrigo, Teresa; Rodríguez-Marrero, Ana Yaiza; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Benaglia, Andrea; Bendavid, Joshua; Benhabib, Lamia; Benitez, Jose F; Bernet, Colin; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Bondu, Olivier; Botta, Cristina; Breuker, Horst; Camporesi, Tiziano; Cerminara, Gianluca; Colafranceschi, Stefano; D'Alfonso, Mariarosaria; D'Enterria, David; Dabrowski, Anne; David Tinoco Mendes, Andre; De Guio, Federico; De Roeck, Albert; De Visscher, Simon; Di Marco, Emanuele; Dobson, Marc; Dordevic, Milos; Dorney, Brian; Dupont-Sagorin, Niels; Elliott-Peisert, Anna; Eugster, Jürg; Franzoni, Giovanni; Funk, Wolfgang; Gigi, Dominique; Gill, Karl; Giordano, Domenico; Girone, Maria; Glege, Frank; Guida, Roberto; Gundacker, Stefan; Guthoff, Moritz; Hammer, Josef; Hansen, Magnus; Harris, Philip; Hegeman, Jeroen; Innocente, Vincenzo; Janot, Patrick; Kousouris, Konstantinos; Krajczar, Krisztian; Lecoq, Paul; Lourenco, Carlos; Magini, Nicolo; Malgeri, Luca; Mannelli, Marcello; Marrouche, Jad; Masetti, Lorenzo; Meijers, Frans; Mersi, Stefano; Meschi, Emilio; Moortgat, Filip; Morovic, Srecko; Mulders, Martijn; Musella, Pasquale; Orsini, Luciano; Pape, Luc; Perez, Emmanuelle; Perrozzi, Luca; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Pierini, Maurizio; Pimiä, Martti; Piparo, Danilo; Plagge, Michael; Racz, Attila; Rolandi, Gigi; Rovere, Marco; Sakulin, Hannes; Schäfer, Christoph; Schwick, Christoph; Sharma, Archana; Siegrist, Patrice; Silva, Pedro; Simon, Michal; Sphicas, Paraskevas; Spiga, Daniele; Steggemann, Jan; Stieger, Benjamin; Stoye, Markus; Takahashi, Yuta; Treille, Daniel; Tsirou, Andromachi; Veres, Gabor Istvan; Wardle, Nicholas; Wöhri, Hermine Katharina; Wollny, Heiner; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; Ingram, Quentin; Kaestli, Hans-Christian; Kotlinski, Danek; Langenegger, Urs; Renker, Dieter; Rohe, Tilman; Bachmair, Felix; Bäni, Lukas; Bianchini, Lorenzo; Buchmann, Marco-Andrea; Casal, Bruno; Chanon, Nicolas; Dissertori, Günther; Dittmar, Michael; Donegà, Mauro; Dünser, Marc; Eller, Philipp; Grab, Christoph; Hits, Dmitry; Hoss, Jan; Lustermann, Werner; Mangano, Boris; Marini, Andrea Carlo; Martinez Ruiz del Arbol, Pablo; Masciovecchio, Mario; Meister, Daniel; Mohr, Niklas; Nägeli, Christoph; Nessi-Tedaldi, Francesca; Pandolfi, Francesco; Pauss, Felicitas; Peruzzi, Marco; Quittnat, Milena; Rebane, Liis; Rossini, Marco; Starodumov, Andrei; Takahashi, Maiko; Theofilatos, Konstantinos; Wallny, Rainer; Weber, Hannsjoerg Artur; Amsler, Claude; Canelli, Maria Florencia; Chiochia, Vincenzo; De Cosa, Annapaola; Hinzmann, Andreas; Hreus, Tomas; Kilminster, Benjamin; Lange, Clemens; Millan Mejias, Barbara; Ngadiuba, Jennifer; Robmann, Peter; Ronga, Frederic Jean; Taroni, Silvia; Verzetti, Mauro; Yang, Yong; Cardaci, Marco; Chen, Kuan-Hsin; Ferro, Cristina; Kuo, Chia-Ming; Lin, Willis; Lu, Yun-Ju; Volpe, Roberta; Yu, Shin-Shan; Chang, Paoti; Chang, You-Hao; Chang, Yu-Wei; Chao, Yuan; Chen, Kai-Feng; Chen, Po-Hsun; Dietz, Charles; Grundler, Ulysses; Hou, George Wei-Shu; Kao, Kai-Yi; Lei, Yeong-Jyi; Liu, Yueh-Feng; Lu, Rong-Shyang; Majumder, Devdatta; Petrakou, Eleni; Tzeng, Yeng-Ming; Wilken, Rachel; Asavapibhop, Burin; Singh, Gurpreet; Srimanobhas, Norraphat; Suwonjandee, Narumon; Adiguzel, Aytul; Bakirci, Mustafa Numan; Cerci, Salim; Dozen, Candan; Dumanoglu, Isa; Eskut, Eda; Girgis, Semiray; Gokbulut, Gul; Gurpinar, Emine; Hos, Ilknur; Kangal, Evrim Ersin; Kayis Topaksu, Aysel; Onengut, Gulsen; Ozdemir, Kadri; Ozturk, Sertac; Polatoz, Ayse; Sunar Cerci, Deniz; Tali, Bayram; Topakli, Huseyin; Vergili, Mehmet; Akin, Ilina Vasileva; Bilin, Bugra; Bilmis, Selcuk; Gamsizkan, Halil; Karapinar, Guler; Ocalan, Kadir; Sekmen, Sezen; Surat, Ugur Emrah; Yalvac, Metin; Zeyrek, Mehmet; Gülmez, Erhan; Isildak, Bora; Kaya, Mithat; Kaya, Ozlem; Cankocak, Kerem; Vardarli, Fuat Ilkehan; Levchuk, Leonid; Sorokin, Pavel; Brooke, James John; Clement, Emyr; Cussans, David; Flacher, Henning; Goldstein, Joel; Grimes, Mark; Heath, Greg P; Heath, Helen F; Jacob, Jeson; Kreczko, Lukasz; Lucas, Chris; Meng, Zhaoxia; Newbold, Dave M; Paramesvaran, Sudarshan; Poll, Anthony; Senkin, Sergey; Smith, Vincent J; Williams, Thomas; Bell, Ken W; Belyaev, Alexander; Brew, Christopher; Brown, Robert M; Cockerill, David JA; Coughlan, John A; Harder, Kristian; Harper, Sam; Olaiya, Emmanuel; Petyt, David; Shepherd-Themistocleous, Claire; Thea, Alessandro; Tomalin, Ian R; Womersley, William John; Worm, Steven; Baber, Mark; Bainbridge, Robert; Buchmuller, Oliver; Burton, Darren; Colling, David; Cripps, Nicholas; Cutajar, Michael; Dauncey, Paul; Davies, Gavin; Della Negra, Michel; Dunne, Patrick; Ferguson, William; Fulcher, Jonathan; Futyan, David; Gilbert, Andrew; Hall, Geoffrey; Iles, Gregory; Jarvis, Martyn; Karapostoli, Georgia; Kenzie, Matthew; Lane, Rebecca; Lucas, Robyn; Lyons, Louis; Magnan, Anne-Marie; Malik, Sarah; Mathias, Bryn; Nash, Jordan; Nikitenko, Alexander; Pela, Joao; Pesaresi, Mark; Petridis, Konstantinos; Raymond, David Mark; Rogerson, Samuel; Rose, Andrew; Seez, Christopher; Sharp, Peter; Tapper, Alexander; Vazquez Acosta, Monica; Virdee, Tejinder; Zenz, Seth Conrad; Cole, Joanne; Hobson, Peter R; Khan, Akram; Kyberd, Paul; Leggat, Duncan; Leslie, Dawn; Martin, William; Reid, Ivan; Symonds, Philip; Teodorescu, Liliana; Turner, Mark; Dittmann, Jay; Hatakeyama, Kenichi; Kasmi, Azeddine; Liu, Hongxuan; Scarborough, Tara; Charaf, Otman; Cooper, Seth; Henderson, Conor; Rumerio, Paolo; Avetisyan, Aram; Bose, Tulika; Fantasia, Cory; Lawson, Philip; Richardson, Clint; Rohlf, James; St John, Jason; Sulak, Lawrence; Alimena, Juliette; Berry, Edmund; Bhattacharya, Saptaparna; Christopher, Grant; Cutts, David; Demiragli, Zeynep; Dhingra, Nitish; Ferapontov, Alexey; Garabedian, Alex; Heintz, Ulrich; Kukartsev, Gennadiy; Laird, Edward; Landsberg, Greg; Luk, Michael; Narain, Meenakshi; Segala, Michael; Sinthuprasith, Tutanon; Speer, Thomas; Swanson, Joshua; Breedon, Richard; Breto, Guillermo; Calderon De La Barca Sanchez, Manuel; Chauhan, Sushil; Chertok, Maxwell; Conway, John; Conway, Rylan; Cox, Peter Timothy; Erbacher, Robin; Gardner, Michael; Ko, Winston; Lander, Richard; Miceli, Tia; Mulhearn, Michael; Pellett, Dave; Pilot, Justin; Ricci-Tam, Francesca; Searle, Matthew; Shalhout, Shalhout; Smith, John; Squires, Michael; Stolp, Dustin; Tripathi, Mani; Wilbur, Scott; Yohay, Rachel; Cousins, Robert; Everaerts, Pieter; Farrell, Chris; Hauser, Jay; Ignatenko, Mikhail; Rakness, Gregory; Takasugi, Eric; Valuev, Vyacheslav; Weber, Matthias; Burt, Kira; Clare, Robert; Ellison, John Anthony; Gary, J William; Hanson, Gail; Heilman, Jesse; Ivova Rikova, Mirena; Jandir, Pawandeep; Kennedy, Elizabeth; Lacroix, Florent; Long, Owen Rosser; Luthra, Arun; Malberti, Martina; Nguyen, Harold; Olmedo Negrete, Manuel; Shrinivas, Amithabh; Sumowidagdo, Suharyo; Wimpenny, Stephen; Andrews, Warren; Branson, James G; Cerati, Giuseppe Benedetto; Cittolin, Sergio; D'Agnolo, Raffaele Tito; Evans, David; Holzner, André; Kelley, Ryan; Klein, Daniel; Lebourgeois, Matthew; Letts, James; Macneill, Ian; Olivito, Dominick; Padhi, Sanjay; Palmer, Christopher; Pieri, Marco; Sani, Matteo; Sharma, Vivek; Simon, Sean; Sudano, Elizabeth; Tadel, Matevz; Tu, Yanjun; Vartak, Adish; Welke, Charles; Würthwein, Frank; Yagil, Avraham; Barge, Derek; Bradmiller-Feld, John; Campagnari, Claudio; Danielson, Thomas; Dishaw, Adam; Dutta, Valentina; Flowers, Kristen; Franco Sevilla, Manuel; Geffert, Paul; George, Christopher; Golf, Frank; Gouskos, Loukas; Incandela, Joe; Justus, Christopher; Mccoll, Nickolas; Richman, Jeffrey; Stuart, David; To, Wing; West, Christopher; Yoo, Jaehyeok; Apresyan, Artur; Bornheim, Adolf; Bunn, Julian; Chen, Yi; Duarte, Javier; Mott, Alexander; Newman, Harvey B; Pena, Cristian; Rogan, Christopher; Spiropulu, Maria; Timciuc, Vladlen; Vlimant, Jean-Roch; Wilkinson, Richard; Xie, Si; Zhu, Ren-Yuan; Azzolini, Virginia; Calamba, Aristotle; Carlson, Benjamin; Ferguson, Thomas; Iiyama, Yutaro; Paulini, Manfred; Russ, James; Vogel, Helmut; Vorobiev, Igor; Cumalat, John Perry; Ford, William T; Gaz, Alessandro; Luiggi Lopez, Eduardo; Nauenberg, Uriel; Smith, James; Stenson, Kevin; Ulmer, Keith; Wagner, Stephen Robert; Alexander, James; Chatterjee, Avishek; Chu, Jennifer; Dittmer, Susan; Eggert, Nicholas; Mirman, Nathan; Nicolas Kaufman, Gala; Patterson, Juliet Ritchie; Ryd, Anders; Salvati, Emmanuele; Skinnari, Louise; Sun, Werner; Teo, Wee Don; Thom, Julia; Thompson, Joshua; Tucker, Jordan; Weng, Yao; Winstrom, Lucas; Wittich, Peter; Winn, Dave; Abdullin, Salavat; Albrow, Michael; Anderson, Jacob; Apollinari, Giorgio; Bauerdick, Lothar AT; Beretvas, Andrew; Berryhill, Jeffrey; Bhat, Pushpalatha C; Bolla, Gino; Burkett, Kevin; Butler, Joel Nathan; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Elvira, Victor Daniel; Fisk, Ian; Freeman, Jim; Gao, Yanyan; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Hanlon, Jim; Hare, Daryl; Harris, Robert M; Hirschauer, James; Hooberman, Benjamin; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Kaadze, Ketino; Klima, Boaz; Kreis, Benjamin; Kwan, Simon; Linacre, Jacob; Lincoln, Don; Lipton, Ron; Liu, Tiehui; Lykken, Joseph; Maeshima, Kaori; Marraffino, John Michael; Martinez Outschoorn, Verena Ingrid; Maruyama, Sho; Mason, David; McBride, Patricia; Merkel, Petra; Mishra, Kalanand; Mrenna, Stephen; Musienko, Yuri; Nahn, Steve; Newman-Holmes, Catherine; O'Dell, Vivian; Prokofyev, Oleg; Sexton-Kennedy, Elizabeth; Sharma, Seema; Soha, Aron; Spalding, William J; Spiegel, Leonard; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vidal, Richard; Whitbeck, Andrew; Whitmore, Juliana; Yang, Fan; Acosta, Darin; Avery, Paul; Bortignon, Pierluigi; Bourilkov, Dimitri; Carver, Matthew; Cheng, Tongguang; Curry, David; Das, Souvik; De Gruttola, Michele; Di Giovanni, Gian Piero; Field, Richard D; Fisher, Matthew; Furic, Ivan-Kresimir; Hugon, Justin; Konigsberg, Jacobo; Korytov, Andrey; Kypreos, Theodore; Low, Jia Fu; Matchev, Konstantin; Milenovic, Predrag; Mitselmakher, Guenakh; Muniz, Lana; Rinkevicius, Aurelijus; Shchutska, Lesya; Snowball, Matthew; Sperka, David; Yelton, John; Zakaria, Mohammed; Hewamanage, Samantha; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Adams, Todd; Askew, Andrew; Bochenek, Joseph; Diamond, Brendan; Haas, Jeff; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Prosper, Harrison; Veeraraghavan, Venkatesh; Weinberg, Marc; Baarmand, Marc M; Hohlmann, Marcus; Kalakhety, Himali; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Bazterra, Victor Eduardo; Berry, Douglas; Betts, Russell Richard; Bucinskaite, Inga; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Khalatyan, Samvel; Kurt, Pelin; Moon, Dong Ho; O'Brien, Christine; Silkworth, Christopher; Turner, Paul; Varelas, Nikos; Albayrak, Elif Asli; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Duru, Firdevs; Haytmyradov, Maksat; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Rahmat, Rahmat; Sen, Sercan; Tan, Ping; Tiras, Emrah; Wetzel, James; Yetkin, Taylan; Yi, Kai; Barnett, Bruce Arnold; Blumenfeld, Barry; Bolognesi, Sara; Fehling, David; Gritsan, Andrei; Maksimovic, Petar; Martin, Christopher; Swartz, Morris; Baringer, Philip; Bean, Alice; Benelli, Gabriele; Bruner, Christopher; Kenny III, Raymond Patrick; Malek, Magdalena; Murray, Michael; Noonan, Daniel; Sanders, Stephen; Sekaric, Jadranka; Stringer, Robert; Wang, Quan; Wood, Jeffrey Scott; Chakaberia, Irakli; Ivanov, Andrew; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Saini, Lovedeep Kaur; Shrestha, Shruti; Skhirtladze, Nikoloz; Svintradze, Irakli; Gronberg, Jeffrey; Lange, David; Rebassoo, Finn; Wright, Douglas; Baden, Drew; Belloni, Alberto; Calvert, Brian; Eno, Sarah Catherine; Gomez, Jaime; Hadley, Nicholas John; Kellogg, Richard G; Kolberg, Ted; Lu, Ying; Marionneau, Matthieu; Mignerey, Alice; Pedro, Kevin; Skuja, Andris; Tonjes, Marguerite; Tonwar, Suresh C; Apyan, Aram; Barbieri, Richard; Bauer, Gerry; Busza, Wit; Cali, Ivan Amos; Chan, Matthew; Di Matteo, Leonardo; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Gulhan, Doga; Klute, Markus; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Ma, Teng; Paus, Christoph; Ralph, Duncan; Roland, Christof; Roland, Gunther; Stephans, George; Stöckli, Fabian; Sumorok, Konstanty; Velicanu, Dragos; Veverka, Jan; Wyslouch, Bolek; Yang, Mingming; Zanetti, Marco; Zhukova, Victoria; Dahmes, Bryan; Gude, Alexander; Kao, Shih-Chuan; Klapoetke, Kevin; Kubota, Yuichi; Mans, Jeremy; Pastika, Nathaniel; Rusack, Roger; Singovsky, Alexander; Tambe, Norbert; Turkewitz, Jared; Acosta, John Gabriel; Oliveros, Sandra; Avdeeva, Ekaterina; Bloom, Kenneth; Bose, Suvadeep; Claes, Daniel R; Dominguez, Aaron; Gonzalez Suarez, Rebeca; Keller, Jason; Knowlton, Dan; Kravchenko, Ilya; Lazo-Flores, Jose; Malik, Sudhir; Meier, Frank; Snow, Gregory R; Zvada, Marian; Dolen, James; Godshalk, Andrew; Iashvili, Ia; Kharchilava, Avto; Kumar, Ashish; Rappoccio, Salvatore; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Chasco, Matthew; Haley, Joseph; Massironi, Andrea; Morse, David Michael; Nash, David; Orimoto, Toyoko; Trocino, Daniele; Wang, Ren-Jie; Wood, Darien; Zhang, Jinzhong; Hahn, Kristan Allan; Kubik, Andrew; Mucia, Nicholas; Odell, Nathaniel; Pollack, Brian; Pozdnyakov, Andrey; Schmitt, Michael Henry; Stoynev, Stoyan; Sung, Kevin; Velasco, Mayda; Won, Steven; Brinkerhoff, Andrew; Chan, Kwok Ming; Drozdetskiy, Alexey; Hildreth, Michael; Jessop, Colin; Karmgard, Daniel John; Kellams, Nathan; Lannon, Kevin; Luo, Wuming; Lynch, Sean; Marinelli, Nancy; Pearson, Tessa; Planer, Michael; Ruchti, Randy; Valls, Nil; Wayne, Mitchell; Wolf, Matthias; Woodard, Anna; Antonelli, Louis; Brinson, Jessica; Bylsma, Ben; Durkin, Lloyd Stanley; Flowers, Sean; Hart, Andrew; Hill, Christopher; Hughes, Richard; Kotov, Khristian; Ling, Ta-Yung; Puigh, Darren; Rodenburg, Marissa; Smith, Geoffrey; Winer, Brian L; Wolfe, Homer; Wulsin, Howard Wells; Driga, Olga; Elmer, Peter; Hebda, Philip; Hunt, Adam; Koay, Sue Ann; Lujan, Paul; Marlow, Daniel; Medvedeva, Tatiana; Mooney, Michael; Olsen, James; Piroué, Pierre; Quan, Xiaohang; Saka, Halil; Stickland, David; Tully, Christopher; Werner, Jeremy Scott; Zuranski, Andrzej; Brownson, Eric; Mendez, Hector; Ramirez Vargas, Juan Eduardo; Barnes, Virgil E; Benedetti, Daniele; Bortoletto, Daniela; De Mattia, Marco; Gutay, Laszlo; Hu, Zhen; Jha, Manoj; Jones, Matthew; Jung, Kurt; Kress, Matthew; Leonardo, Nuno; Lopes Pegna, David; Maroussov, Vassili; Miller, David Harry; Neumeister, Norbert; Radburn-Smith, Benjamin Charles; Shi, Xin; Shipsey, Ian; Silvers, David; Svyatkovskiy, Alexey; Wang, Fuqiang; Xie, Wei; Xu, Lingshan; Yoo, Hwi Dong; Zablocki, Jakub; Zheng, Yu; Parashar, Neeti; Stupak, John; Adair, Antony; Akgun, Bora; Ecklund, Karl Matthew; Geurts, Frank JM; Li, Wei; Michlin, Benjamin; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Zabel, James; Betchart, Burton; Bodek, Arie; Covarelli, Roberto; de Barbaro, Pawel; Demina, Regina; Eshaq, Yossof; Ferbel, Thomas; Garcia-Bellido, Aran; Goldenzweig, Pablo; Han, Jiyeon; Harel, Amnon; Khukhunaishvili, Aleko; Petrillo, Gianluca; Vishnevskiy, Dmitry; Ciesielski, Robert; Demortier, Luc; Goulianos, Konstantin; Lungu, Gheorghe; Mesropian, Christina; Arora, Sanjay; Barker, Anthony; Chou, John Paul; Contreras-Campana, Christian; Contreras-Campana, Emmanuel; Duggan, Daniel; Ferencek, Dinko; Gershtein, Yuri; Gray, Richard; Halkiadakis, Eva; Hidas, Dean; Kaplan, Steven; Lath, Amitabh; Panwalkar, Shruti; Park, Michael; Patel, Rishi; Salur, Sevil; Schnetzer, Steve; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Rose, Keith; Spanier, Stefan; York, Andrew; Bouhali, Othmane; Castaneda Hernandez, Alfredo; Eusebi, Ricardo; Flanagan, Will; Gilmore, Jason; Kamon, Teruki; Khotilovich, Vadim; Krutelyov, Vyacheslav; Montalvo, Roy; Osipenkov, Ilya; Pakhotin, Yuriy; Perloff, Alexx; Roe, Jeffrey; Rose, Anthony; Safonov, Alexei; Sakuma, Tai; Suarez, Indara; Tatarinov, Aysen; Akchurin, Nural; Cowden, Christopher; Damgov, Jordan; Dragoiu, Cosmin; Dudero, Phillip Russell; Faulkner, James; Kovitanggoon, Kittikul; Kunori, Shuichi; Lee, Sung Won; Libeiro, Terence; Volobouev, Igor; Appelt, Eric; Delannoy, Andrés G; Greene, Senta; Gurrola, Alfredo; Johns, Willard; Maguire, Charles; Mao, Yaxian; Melo, Andrew; Sharma, Monika; Sheldon, Paul; Snook, Benjamin; Tuo, Shengquan; Velkovska, Julia; Arenton, Michael Wayne; Boutle, Sarah; Cox, Bradley; Francis, Brian; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Lin, Chuanzhe; Neu, Christopher; Wood, John; Clarke, Christopher; Harr, Robert; Karchin, Paul Edmund; Kottachchi Kankanamge Don, Chamath; Lamichhane, Pramod; Sturdy, Jared; Belknap, Donald; Carlsmith, Duncan; Cepeda, Maria; Dasu, Sridhara; Dodd, Laura; Duric, Senka; Friis, Evan; Hall-Wilton, Richard; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Lanaro, Armando; Lazaridis, Christos; Levine, Aaron; Loveless, Richard; Mohapatra, Ajit; Ojalvo, Isabel; Perry, Thomas; Pierro, Giuseppe Antonio; Polese, Giovanni; Ross, Ian; Sarangi, Tapas; Savin, Alexander; Smith, Wesley H; Taylor, Devin; Verwilligen, Piet; Vuosalo, Carl; Woods, Nathaniel

    2015-04-07

    Dimuon and dielectron mass spectra, obtained from data resulting from proton-proton collisions at 8 TeV and recorded by the CMS experiment, are used to search for both narrow resonances and broad deviations from standard model predictions. The data correspond to an integrated luminosity of 20.6 (19.7) fb$^{-1}$ for the dimuon (dielectron) channel. No evidence for non-standard-model physics is observed and 95% confidence level limits are set on parameters from a number of new physics models. The narrow resonance analyses exclude a Sequential Standard Model $\\mathrm{Z'_{SSM}}$ resonance lighter than 2.90 TeV, a superstring-inspired $\\mathrm{Z'_{\\psi}}$ lighter than 2.57 TeV and Randall--Sundrum Kaluza--Klein gravitons with masses below 2.73, 2.35, and 1.27 TeV for couplings of 0.10, 0.05, and 0.01, respectively. A notable feature is that the limits have been calculated in a model-independent way to enable straightforward reinterpretation in any model predicting a resonance structure. The observed events are als...

  6. Measurements of Cosmic-Ray Proton and Helium Spectra from the BESS-Polar Long-Duration Balloon Flights Over Antarctica

    Science.gov (United States)

    Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; Kim, K. C.; Kumazawa, T.; Kusumoto, A.; hide

    2016-01-01

    The BESS-Polar Collaboration measured the energy spectra of cosmic-ray protons and helium during two long-duration balloon flights over Antarctica in December 2004 and December 2007, at substantially different levels of solar modulation. Proton and helium spectra probe the origin and propagation history of cosmic rays in the galaxy, and are essential to calculations of the expected spectra of cosmic-ray antiprotons, positrons, and electrons from interactions of primary cosmic-ray nuclei with the interstellar gas, and to calculations of atmospheric muons and neutrinos. We report absolute spectra at the top of the atmosphere for cosmic-ray protons in the kinetic energy range 0.2-160 GeV and helium nuclei 0.15-80 GeV/nucleon. The corresponding magnetic rigidity ranges are 0.6-160 GV for protons and 1.1-160 GV for helium. These spectra are compared to measurements from previous BESS flights and from ATIC-2, PAMELA, and AMS-02. We also report the ratio of the proton and helium fluxes from 1.1 GV to 160 GV and compare to ratios from PAMELA and AMS-02.

  7. MEASUREMENTS OF COSMIC-RAY PROTON AND HELIUM SPECTRA FROM THE BESS-POLAR LONG-DURATION BALLOON FLIGHTS OVER ANTARCTICA

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K.; Itazaki, A.; Kusumoto, A.; Matsukawa, Y.; Orito, R. [Kobe University, Kobe, Hyogo 657-8501 (Japan); Fuke, H. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Haino, S.; Hasegawa, M.; Horikoshi, A.; Kumazawa, T.; Makida, Y.; Matsuda, S.; Matsumoto, K.; Nozaki, M. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan); Hams, T.; Mitchell, J. W. [NASA-Goddard Space Flight Center (NASA-GSFC), Greenbelt, MD 20771 (United States); Kim, K. C.; Lee, M. H.; Myers, Z. [IPST, University of Maryland, College Park, MD 20742 (United States); Nishimura, J., E-mail: Kenichi.Sakai@nasa.gov [The University of Tokyo, Bunkyo, Tokyo 113-0033 (Japan); and others

    2016-05-10

    The BESS-Polar Collaboration measured the energy spectra of cosmic-ray protons and helium during two long-duration balloon flights over Antarctica in 2004 December and 2007 December at substantially different levels of solar modulation. Proton and helium spectra probe the origin and propagation history of cosmic rays in the galaxy, and are essential to calculations of the expected spectra of cosmic-ray antiprotons, positrons, and electrons from interactions of primary cosmic-ray nuclei with the interstellar gas, and to calculations of atmospheric muons and neutrinos. We report absolute spectra at the top of the atmosphere for cosmic-ray protons in the kinetic energy range 0.2–160 GeV and helium nuclei in the range 0.15–80 GeV/nucleon. The corresponding magnetic-rigidity ranges are 0.6–160 GV for protons and 1.1–160 GV for helium. These spectra are compared to measurements from previous BESS flights and from ATIC-2, PAMELA, and AMS-02. We also report the ratio of the proton and helium fluxes from 1.1 to 160 GV and compare this to the ratios from PAMELA and AMS-02.

  8. Galactic cosmic ray spectra during solar cycle 23 and 24. Measurement capabilities of the electron proton helium telescope on board SOHO

    Energy Technology Data Exchange (ETDEWEB)

    Kuehl, Patrick; Dresing, Nina; Gieseler, Jan; Heber, Bernd; Klassen, Andreas [Christian-Albrechts Universitaet zu Kiel (Germany)

    2016-07-01

    The solar modulation of galactic cosmic rays (GCR) can be studied in detail by long term variations of the GCR energy spectrum (e.g. on the scales of a solar cycle). With almost 20 years of data, the Electron Proton Helium INstrument (EPHIN) aboard SOHO is well suited for these kind of investigations. Although the design of the instrument is optimized to measure proton and helium isotope spectra up to 50 MeV/nucleon the capability exist that allow to determine energy spectra above 1.5 GeV/nucleon. Therefore we developed a sophisticated inversion method to calculate such proton spectra. The method relies on a GEANT4 Monte Carlo simulation of the instrument and a simplified spacecraft model that calculates the energy response function of EPHIN for electrons, protons and heavier ions. As a result we present galactic cosmic ray spectra from 1995 to 2015. For validation, the derived spectra are compared to AMS, BESS and PAMELA data. Furthermore we discuss the spectra with respect to the solar modulation.

  9. Detection of the sulfhydryl groups in proteins with slow hydrogen exchange rates and determination of their proton/deuteron fractionation factors using the deuterium-induced effects on the 13C(beta) NMR signals.

    Science.gov (United States)

    Takeda, Mitsuhiro; Jee, JunGoo; Terauchi, Tsutomu; Kainosho, Masatsune

    2010-05-05

    A method for identifying cysteine (Cys) residues with sulfhydryl (SH) groups exhibiting slow hydrogen exchange rates has been developed for proteins in aqueous media. The method utilizes the isotope shifts of the C(beta) chemical shifts induced by the deuteration of the SH groups. The 18.2 kDa E. coli peptidyl prolyl cis-trans isomerase b (EPPIb), which was selectively labeled with [3-(13)C;3,3-(2)H(2)]Cys, showed much narrower line widths for the (13)C(beta) NMR signals, as compared to those of the proteins labeled with either [3-(13)C]Cys or (3R)-[3-(13)C;3-(2)H]Cys. The (13)C(beta) signals of the two Cys residues of EPPIb, i.e. Cys-31 and Cys-121, labeled with [3-(13)C;3,3-(2)H(2)]Cys, split into four signals in H(2)O/D(2)O (1:1) at 40 degrees C and pH 7.5, indicating that the exchange rates of the side-chain SH's and the backbone amides are too slow to average the chemical shift differences of the (13)C(beta) signals, due to the two- and three-bond isotope shifts. By virtue of the well-separated signals, the proton/deuteron fractional factors for both the SH and amide groups of the two Cys residues in EPPIb could be directly determined, as approximately 0.4-0.5 for [SD]/[SH] and 0.9-1.0 for [ND]/[NH], by the relative intensities of the NMR signals for the isotopomers. The proton NOE's of the two slowly exchanging SH's were clearly identified in the NOESY spectra and were useful for the determining the local structure of EPPIb around the Cys residues.

  10. NMR of lignins

    Science.gov (United States)

    John Ralph; Larry L. Landucci

    2010-01-01

    This chapter will consider the basic aspects and findings of several forms of NMR spectroscopy, including separate discussions of proton, carbon, heteronuclear, and multidimensional NMR. Enhanced focus will be on 13C NMR, because of its qualitative and quantitative importance, followed by NMR’s contributions to our understanding of lignin...

  11. NMR study of conformational exchange and double-well proton potential in intramolecular hydrogen bonds in monoanions of succinic acid and derivatives.

    Science.gov (United States)

    Guo, Jing; Tolstoy, Peter M; Koeppe, B; Denisov, Gleb S; Limbach, Hans-Heinrich

    2011-09-08

    We present a (1)H, (2)H, and (13)C NMR study of the monoanions of succinic (1), meso- and rac-dimethylsuccinic (2, 3), and methylsuccinic (4) acids (with tetraalkylammonium as the counterion) dissolved in CDF(3)/CDF(2)Cl at 300-120 K. In all four monoanions, the carboxylic groups are linked by a short intramolecular OHO hydrogen bond revealed by the bridging-proton chemical shift of about 20 ppm. We show that the flexibility of the carbon skeleton allows for two gauche isomers in monoanions 1, 2, and 4, interconverting through experimental energy barriers of 10-15 kcal/mol (the process itself and the energy barrier are also reproduced in MP2/6-311++G** calculations). In 3, one of the gauche forms is absent because of the steric repulsion of the methyl groups. In all four monoanions, the bridging proton is located in a double-well potential and subject, at least to some extent, to proton tautomerism, for which we estimate the two proton positions to be separated by ca. 0.2 Å. In 1 and 3, the proton potential is symmetric. In 2, slowing the conformational interconversion introduces an asymmetry to the proton potential, an effect that might be strong enough even to synchronize the proton tautomerism with the interconversion of the two gauche forms. In 4, the asymmetry of the proton potential is due to the asymmetric substitution. The intramolecular H-bond is likely to remain intact during the interconversion of the gauche forms in 1, 3, and 4, whereas the situation in 2 is less clear.

  12. Structure of pyridine and quinoline vinyl ethers according to data from 1H and 13C NMR spectra and quantum-chemical calculations

    International Nuclear Information System (INIS)

    Afonin, A.V.; Voronov, V.K.; Andriankov, M.A.; Danovich, D.K.

    1987-01-01

    A systematic investigation of the structure of the vinyl ethers of heterocyclic compounds has not been undertaken. The present work was devoted to investigation of the stereochemical and electronic structure of the vinyl ethers of pyridine and quinoline. The PMR spectra of the samples were recorded for 5% solutions in deuterochloroform on a Tesla BS-497 spectrometer at 100 MHz. The 13 C NMR spectra were recorded on a Tesla BS-567A spectrometer at 25.1 MHz in deuterochloroform with the samples at concentrations of 30%. The internal standard was HMDS. The vinyl ethers of pyridine and quinoline exist preferentially in the nonplanar S-trans conformation. In the vinyl esters of pyridine and quinoline the p-π conjugation is concurrent in nature and depends on the position of the vinyloxy group in the heterocycle

  13. Stopping power measurements with 17-GeV/c protons at the AGS or inclusive proton spectra from proton-nucleus interactions at 17 GeV/c

    International Nuclear Information System (INIS)

    Remsberg, L.P.; Barton, D.S.; Bunce, G.

    1984-01-01

    The problem of nuclear stopping power and its importance to the study of nucleus-nucleus collisions at very high energies was brought to general attention one year ago at Quark Matter 83 by Busza and Goldhaber. In this context, nuclear stopping power can be thought of as the rate of energy (or rapidity) loss of a proton traversing nuclear matter. It does not directly address the important question of energy deposition. Busza and Goldhaber showed that knowledge of nuclear stopping power is needed to estimate the minimum center-of-mass energy required in nucleus-nucleus collisions to ensure the production of very high temperatures at low baryon density. At cm energies of about 1 to 10 GeV/A, the stopping power is important in the estimation of the maximum baryon densities attainable in nucleus-nucleus collisions. The data presented are more relevant to this latter point

  14. Proton and pion spectra at large angles in relativistic heavy-ion collisions

    International Nuclear Information System (INIS)

    Nagamiya, S.; Tanihata, I.; Schnetzer, S.; Anderson, L.; Brueckner, W.; Chamberlain, O.; Shapiro, G.; Steiner, H.

    1977-08-01

    In collisions of 800 MeV/N C on C and Pb, and of 800 MeV/N Ne on NaF, Cu, and Pb, energy and angular distributions of light charged fragments were measured at angles from 15 to 145 0 by a magnetic spectrometer for fragment energies up to a few GeV. The inclusive spectra are presented as well as some results and discussion of future possibilities for two or more particle coincidence experiments

  15. Cellobiose as a model system to reveal cellulose dissolution mechanism in acetate-based ionic liquids: Density functional theory study substantiated by NMR spectra.

    Science.gov (United States)

    Cao, Bobo; Du, Jiuyao; Du, Dongmei; Sun, Haitao; Zhu, Xiao; Fu, Hui

    2016-09-20

    Cellulose dissolution mechanism in acetate-based ionic liquids was systematically studied in Nuclear Magnetic Resonance (NMR) spectra and Density Functional Theory (DFT) methods by using cellobiose and 1-butyl-3-methylimidazolium acetate (BmimAc) as a model system. The solubility of cellulose in ionic liquid increased with temperature increase in the range of 90-140°C. NMR spectra suggested OAc(-) preferred to form stronger hydrogen bonds with hydrogen of hydroxyl in cellulose. Electrostatic potential method was employed to predict the most possible reaction sites and locate the most stable configuration. Atoms in molecules (AIM) theory was used to study the features of bonds at bond critical points and the variations of bond types. Simultaneously, noncovalent interactions were characterized and visualized by employing reduced density gradient analysis combined with Visual Molecular Dynamics (VMD) program. Natural bond orbital (NBO) theory was applied to study the noncovalent nature and characterize the orbital interactions between cellobiose and Bmim[OAc]. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Intra- versus Intermolecular Hydrogen Bonding: Solvent-Dependent Conformational Preferences of a Common Supramolecular Binding Motif from 1 H NMR and Vibrational Circular Dichroism Spectra.

    Science.gov (United States)

    Demarque, Daniel P; Merten, Christian

    2017-12-19

    When predicting binding properties of small molecules or larger supramolecular aggregates, intra- and intermolecular hydrogen bonds are often considered the most important factor. Spectroscopic techniques such as 1 H NMR spectroscopy are typically utilized to characterize such binding events, but interpretation is often qualitative and follows chemical intuition. In this study, we compare the effects of intramolecular hydrogen bonding and solvation on two chiral 2,6-pyridinediyl-dialkylamides. In comparison with 1 H NMR spectroscopy, vibrational circular dichroism (VCD) spectroscopy proved to be more sensitive to conformational changes. In fact, the change of the solvent from CDCl 3 to [D 6 ]DMSO generates mirror-image VCD spectra for the same enantiomer. Here, the common sense that the sterically less hindered group is more prone to solvation proved to be wrong according predicted VCD spectra, which clearly show that both asymmetric amide hydrogens are equally likely to be solvated, but never simultaneously. The competition between intra- and intermolecular hydrogen bonding and their importance for a correct prediction of spectral properties are discussed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. 1H NMR visibility of mammalian glycogen in solution

    International Nuclear Information System (INIS)

    Zang, L.H.; Rothman, D.L.; Shulman, R.G.

    1990-01-01

    High-resolution 1 H NMR spectra of rabbit liver glycogen in 2 H 2 O were obtained at 500 MHz, and several resonances were assigned by comparison with the chemical shifts of α-linked diglucose molecules. The NMR relaxation times T 1 and T 2 of glycogen in 2 H 2 O were determined to be 1.1 and 0.029 s, respectively. The measured natural linewidth of the carbon-1 proton is in excellent agreement with that calculated from T 2 . The visibility measurements made by digesting glycogen and comparing glucose and glycogen signal intensities demonstrate that in spite of the very high molecular weight, all of the proton nuclei in glycogen contribute to the NMR spectrum. The result is not unexpected, since 100% NMR visibility was previously observed from the carbon nuclei of glycogen, due to the rapid intramolecular motions

  18. Electron photon spectra at atmospheric depths 260 and 400 gm/cm2 derived from the Goddard primary proton spectrum using Fermilab data and usual cascade theory

    International Nuclear Information System (INIS)

    Bhattacharyya, D.P.; Gautam, V.P.

    1982-01-01

    The integral electron photon spectra of cosmic rays at airplane altitude and Lenin Peak (altitudes 260 and 400 g-cm -2 air) have been estimated from the primary proton spectrum of Goddard Space Flight Group using Fermilab data of pp→π +- +X and conventional cascade theory. The derived electron-photon spectra fits well the experimental data of Ohta et al. (1975) and Cherdyntseva and Nikol'skii (1976) for energies above 4 TeV

  19. O-17 NMR measurement of water

    International Nuclear Information System (INIS)

    Fukazawa, Nobuyuki

    1990-01-01

    Recently, attention has been paid to the various treatment of water and the utilization of water by magnetic treatment, electric field treatment and so on. It has been said that by these treatments, the change in the properties of water arises. The state of this treated water cannot be explained by the properties of water from conventional physical and chemical standpoints. In addition, the method of measurement of whether the change arose or not is not yet determined. It is necessary to establish the method of measurement for the basic state of water. In this study, O-17 NMR which observes the state of water directly at molecular or atomic level was investigated as the method of measuring water. The measurement of O-17 NMR was carried out with a JNR 90Q FT NMR of Fourier transformation type of JEOL Ltd. The experimental method and the results are reported. The result of measurement of the O-17 NMR spectrum for distilled ion exchange water is shown. It is know that it has very wide line width as compared with the NMR spectra of protons and C-13. The relative sensitivity of O-17 observation is about 1/100,000 of that of protons. As to the information on the state of water obtained by O-17 NMR, there are chemical shift and line width. As temperature rose, the line width showed decrease, which seemed to be related to the decrease of hydrogen combination. (K.I.)

  20. Absolute quantitative proton NMR spectroscopy based on the amplitude of the local water suppression pulse. Quantification of brain water and metabolites

    DEFF Research Database (Denmark)

    Danielsen, E R; Henriksen, O

    1994-01-01

    Quantification in localized proton NMR spectroscopy has been achieved by various methods in recent years. A new method for absolute quantification is described in this paper. The method simultaneously rules out problems with B1 field inhomogeneity and coil loading, utilizing a relation between th......M and [NAA] = 9.15 +/- 0.74 nM. It is concluded that the quantification method is easily applied in vivo, and that the absolute concentrations obtained are similar to results in other studies except those relying on assumptions of the concentration of an internal reference. The advantage...

  1. Studies of protonic self-diffusion and conductivity in 12-tungstophophoric acid hydrates by pulsed field gradient 1H NMR and ac Conductivity

    International Nuclear Information System (INIS)

    Slade, R.C.; Pressman, H.A.; Barker, J.; Strange, J.H.

    1988-01-01

    Temperature dependent protonic conductivities σ and 1/H self-diffusion coefficients, D, are reported for polycrystalline hydrates of 12-tungstophosphoric acid (TPA). Conductivities were measured using ac admittane spectrometry and diffusion coefficients by the pulsed field gradient NMR technique. Conductivities for the hydrates TPA.nH 2 O (n=6, 14, 21) increase with n. Examination of σ and D values and of activation techniques shows self-diffusion and conduction to occur by different mechanisms in the higher hydrates. 25 refs.; 14 figs.; 1 table

  2. Bilayers of phosphatidyldiacylglycerol and phosphatidylcholesterol give 31P-NMR spectra characteristic for hexagonal and isotropic phases

    NARCIS (Netherlands)

    Noggle, J.H.; Marecek, J.F.; Mandal, S.B.; Venetie, R. van; Rogers, J.; Jain, M.K.; Ramirez, F.

    1982-01-01

    Aqueous dispersions of phosphatidyldiacylglycerol and phosphatidylcholesterol are shown to form bilayers by differential scanning calorimetry, diphenylhexatriene fluorescence polarization, and electron microscopy; however, 31P-nuclear magnetic resonance spectra of these dispersions are

  3. Measurement of the Relaxation Rate of the Magnetization in Mn{sub 12}O{sub 12} -Acetate Using Proton NMR Echo

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Z. H. [Department of Physics and Astronomy, Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States); Lascialfari, A. [Dipartimento di Fisica ' ' A. Volta' ' e Unita' , INFM di Pavia, Via Bassi 6, 27100 Pavia, (Italy); Borsa, F. [Department of Physics and Astronomy, Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States); Dipartimento di Fisica ' ' A. Volta' ' e Unita' , INFM di Pavia, Via Bassi 6, 27100 Pavia, (Italy); Gatteschi, D. [Department of Chemistry, University of Florence, Via Maragliano 77, 50144 Firenze, (Italy)

    2000-03-27

    We present a novel method to measure the relaxation rate W of the magnetization of Mn{sub 12}O {sub 12} -acetate (Mn12) magnetic molecular cluster in its S=10 ground state at low T . It is based on the observation of an exponential growth in time of the proton NMR signal during the thermal equilibration of the magnetization of the molecules. We can explain the novel effect with a simple model which relates the intensity of the proton echo signal to the microscopic reversal of the magnetization of each individual Mn12 molecule during the equilibration process. The method should find wide application in the study of magnetic molecular clusters in off-equilibrium conditions. (c) 2000 The American Physical Society.

  4. Estimating side-chain order in methyl-protonated, perdeuterated proteins via multiple-quantum relaxation violated coherence transfer NMR spectroscopy

    International Nuclear Information System (INIS)

    Sun Hechao; Godoy-Ruiz, Raquel; Tugarinov, Vitali

    2012-01-01

    Relaxation violated coherence transfer NMR spectroscopy (Tugarinov et al. in J Am Chem Soc 129:1743–1750, 2007) is an established experimental tool for quantitative estimation of the amplitudes of side-chain motions in methyl-protonated, highly deuterated proteins. Relaxation violated coherence transfer experiments monitor the build-up of methyl proton multiple-quantum coherences that can be created in magnetically equivalent spin-systems as long as their transverse magnetization components relax with substantially different rates. The rate of this build-up is a reporter of the methyl-bearing side-chain mobility. Although the build-up of multiple-quantum 1 H coherences is monitored in these experiments, the decay of the methyl signal during relaxation delays occurs when methyl proton magnetization is in a single-quantum state. We describe a relaxation violated coherence transfer approach where the relaxation of multiple-quantum 1 H– 13 C methyl coherences during the relaxation delay period is quantified. The NMR experiment and the associated fitting procedure that models the time-dependence of the signal build-up, are applicable to the characterization of side-chain order in [ 13 CH 3 ]-methyl-labeled, highly deuterated protein systems up to ∼100 kDa in molecular weight. The feasibility of extracting reliable measures of side-chain order is experimentally verified on methyl-protonated, perdeuterated samples of an 8.5-kDa ubiquitin at 10°C and an 82-kDa Malate Synthase G at 37°C.

  5. Dependence ofthe L-alanyl-L-alanine conformation on molecular charge determined from ab initio computations and NMR spectra

    Czech Academy of Sciences Publication Activity Database

    Sychrovský, Vladimír; Buděšínský, Miloš; Benda, Ladislav; Špirko, Vladimír; Vokáčová, Zuzana; Šebestík, Jaroslav; Bouř, Petr

    2008-01-01

    Roč. 112, č. 6 (2008), s. 1796-1805 ISSN 1520-6106 R&D Projects: GA ČR GA203/06/0420; GA ČR GA202/07/0732; GA AV ČR IAA400550702; GA AV ČR IAA400550701; GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : NMR * ab initio * dipeptide Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.189, year: 2008

  6. Towards understanding the tandem mass spectra of protonated oligopeptides. 2: The proline effect in collision-induced dissociation of protonated Ala-Ala-Xxx-Pro-Ala (Xxx = Ala, Ser, Leu, Val, Phe, and Trp).

    Science.gov (United States)

    Bleiholder, Christian; Suhai, Sándor; Harrison, Alex G; Paizs, Béla

    2011-06-01

    The product ion spectra of proline-containing peptides are commonly dominated by y(n) ions generated by cleavage at the N-terminal side of proline residues. This proline effect is investigated in the current work by collision-induced dissociation (CID) of protonated Ala-Ala-Xxx-Pro-Ala (Xxx includes Ala, Ser, Leu, Val, Phe, and Trp) in an electrospray/quadrupole/time-of-flight (QqTOF) mass spectrometer and by quantum chemical calculations on protonated Ala-Ala-Ala-Pro-Ala. The CID spectra of all investigated peptides show a dominant y(2) ion (Pro-Ala sequence). Our computational results show that the proline effect mainly arises from the particularly low threshold energy for the amide bond cleavage N-terminal to the proline residue, and from the high proton affinity of the proline-containing C-terminal fragment produced by this cleavage. These theoretical results are qualitatively supported by the experimentally observed y(2)/b(3) abundance ratios for protonated Ala-Ala-Xxx-Pro-Ala (Xxx = Ala, Ser, Leu, Val, Phe, and Trp). In the post-cleavage phase of fragmentation the N-terminal oxazolone fragment with the Ala-Ala-Xxx sequence and Pro-Ala compete for the ionizing proton for these peptides. As the proton affinity of the oxazolone fragment increases, the y(2)/b(3) abundance ratio decreases.

  7. Comparison of Australasian tertiary coals based on resolution- enhanced solid-state /sup 13/C NMR spectra

    Energy Technology Data Exchange (ETDEWEB)

    Newman, R H; Davenport, S J

    1986-04-01

    /sup 13/C solid-state nuclear magnetic resonance spectroscopy was used to characterize 32 low-rank coals from New Zealand and Australia. A combination of high magnetic field (4.7 T) and resolution enhancement was used to extract spectral details beyond those seen in published spectra of coals of similar rank. Signal heights were used to characterize organic functional distributions. The spectra showed close similarities between Australian brown coals and low-rank New Zealand subbituminous coals, particularly those mined in the North Island. The spectra of New Zealand lignites all showed stronger signals from cellulose, methoxyl groups and phenols. Almost all of the New Zealand coals showed a relatively strong signal from polymethylene chains, compared with the Australian brown coals. This led to a prediction of higher alkene yields from pyrolysis of the New Zealand coals. Variations in phenolic substitution patterns were attributed to variations in the relative proportions of tannins and lignins in the depositional environments.

  8. Two-dimensional NMR studies of squash family inhibitors. Sequence-specific proton assignments and secondary structure of reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III

    Energy Technology Data Exchange (ETDEWEB)

    Krisnamoorthi, R.; Yuxi Gong; Chanlan Sun Lin (Kansas State Univ., Manhattan (United States)); VanderVelde, D. (Univ. of Kansas, Lawrence (United States))

    1992-01-28

    The solution structure of reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III (CMTI-III*) was investigated by two-dimensional proton nuclear magnetic resonance (2D NMR) spectroscopy. CMTI-III*, prepared by reacting CMTI-III with trypsin which cleaved the Arg5-Ile6 peptide bond, had the two fragments held together by a disulfide linkage. Sequence-specific {sup 1}H NMR resonance assignments were made for all the 29 amino acid residues of the protein. The secondary structure of CMTI-III*, as deduced from NOESY cross peaks and identification of slowly exchanging hydrogens, contains two turns, a 3{sub 10}-helix, and a triple-stranded {beta}-sheet. Sequential proton assignments were also made for the virgin inhibitor, CMTI-III, at pH 4.71, 30C. Comparison of backbone hydrogen chemical shifts of CMTI-III and CMTI-III* revealed significant changes for residues located far away from the reactive-site region as well as for those located near it, indicating tertiary structural changes that are transmitted through most of the 29 residues of the inhibitor protein. These chemical shift changes were relatively small compared to changes that occurred upon hydrolysis of the reactive-site peptide bond between Arg 5 and Ile6 in CMTI-III.

  9. Structural characterization of chemical warfare agent degradation products in decontamination solutions with proton band-selective (1)H-(31)P NMR spectroscopy.

    Science.gov (United States)

    Koskela, Harri; Hakala, Ullastiina; Vanninen, Paula

    2010-06-15

    Decontamination solutions, which are usually composed of strong alkaline chemicals, are used for efficient detoxification of chemical warfare agents (CWAs). The analysis of CWA degradation products directly in decontamination solutions is challenging due to the nature of the matrix. Furthermore, occasionally an unforeseen degradation pathway can result in degradation products which could be eluded to in standard analyses. Here, we present the results of the application of proton band-selective (1)H-(31)P NMR spectroscopy, i.e., band-selective 1D (1)H-(31)P heteronuclear single quantum coherence (HSQC) and band-selective 2D (1)H-(31)P HSQC-total correlation spectroscopy (TOCSY), for ester side chain characterization of organophosphorus nerve agent degradation products in decontamination solutions. The viability of the approach is demonstrated with a test mixture of typical degradation products of nerve agents sarin, soman, and VX. The proton band-selective (1)H-(31)P NMR spectroscopy is also applied in characterization of unusual degradation products of VX in GDS 2000 solution.

  10. Pattern recognition analysis of proton nuclear magnetic resonance spectra of brain tissue extracts from rats anesthetized with propofol or isoflurane.

    Directory of Open Access Journals (Sweden)

    Hiroshi Kawaguchi

    Full Text Available BACKGROUND: General anesthesia is routinely used as a surgical procedure and its safety has been endorsed by clinical outcomes; however, its effects at the molecular level have not been elucidated. General anesthetics influence glucose metabolism in the brain. However, the effects of anesthetics on brain metabolites other than those related to glucose have not been well characterized. We used a pattern recognition analysis of proton nuclear magnetic resonance spectra to visualize the changes in holistic brain metabolic phenotypes in response to the widely used intravenous anesthetic propofol and the volatile anesthetic isoflurane. METHODOLOGY/PRINCIPAL FINDINGS: Rats were randomized into five groups (n = 7 each group. Propofol and isoflurane were administered to two groups each, for 2 or 6 h. The control group received no anesthesia. Brains were removed directly after anesthesia. Hydrophilic compounds were extracted from excised whole brains and measured by proton nuclear magnetic resonance spectroscopy. All spectral data were processed and analyzed by principal component analysis for comparison of the metabolite profiles. Data were visualized by plotting principal component (PC scores. In the plots, each point represents an individual sample. The propofol and isoflurane groups were clustered separately on the plots, and this separation was especially pronounced when comparing the 6-h groups. The PC scores of the propofol group were clearly distinct from those of the control group, particularly in the 6-h group, whereas the difference in PC scores was more subtle in the isoflurane group and control groups. CONCLUSIONS/SIGNIFICANCE: The results of the present study showed that propofol and isoflurane exerted differential effects on holistic brain metabolism under anesthesia.

  11. A phenomenological biological dose model for proton therapy based on linear energy transfer spectra.

    Science.gov (United States)

    Rørvik, Eivind; Thörnqvist, Sara; Stokkevåg, Camilla H; Dahle, Tordis J; Fjaera, Lars Fredrik; Ytre-Hauge, Kristian S

    2017-06-01

    The relative biological effectiveness (RBE) of protons varies with the radiation quality, quantified by the linear energy transfer (LET). Most phenomenological models employ a linear dependency of the dose-averaged LET (LET d ) to calculate the biological dose. However, several experiments have indicated a possible non-linear trend. Our aim was to investigate if biological dose models including non-linear LET dependencies should be considered, by introducing a LET spectrum based dose model. The RBE-LET relationship was investigated by fitting of polynomials from 1st to 5th degree to a database of 85 data points from aerobic in vitro experiments. We included both unweighted and weighted regression, the latter taking into account experimental uncertainties. Statistical testing was performed to decide whether higher degree polynomials provided better fits to the data as compared to lower degrees. The newly developed models were compared to three published LET d based models for a simulated spread out Bragg peak (SOBP) scenario. The statistical analysis of the weighted regression analysis favored a non-linear RBE-LET relationship, with the quartic polynomial found to best represent the experimental data (P = 0.010). The results of the unweighted regression analysis were on the borderline of statistical significance for non-linear functions (P = 0.053), and with the current database a linear dependency could not be rejected. For the SOBP scenario, the weighted non-linear model estimated a similar mean RBE value (1.14) compared to the three established models (1.13-1.17). The unweighted model calculated a considerably higher RBE value (1.22). The analysis indicated that non-linear models could give a better representation of the RBE-LET relationship. However, this is not decisive, as inclusion of the experimental uncertainties in the regression analysis had a significant impact on the determination and ranking of the models. As differences between the models were

  12. NMR imaging

    International Nuclear Information System (INIS)

    Andrew, E.R.

    1983-01-01

    Since hydrogen is the most abundant element in all living organisms, proton NMR lends itself well as a method of investigation in biology and medicine. NMR imaging has some special advantages as a diagnostic tool: no ionizing radiation is used, it is noninvasive; it provides a safer means of imaging than the use of x-rays, gamma rays, positrons, or heavy ions. In contrast with ultrasound, the radiation penetrates the bony structures without attenuation. In additional to morphological information, NMR imaging provides additional diagnostic insights through relaxation parameters, which are not available from other imaging methods. In the decade since the first primitive NMR images were obtained, the quality of images now obtained approaches those from CT x-ray scanners. Prototype instruments are being constructed for clinical evaluation and the first whole-body scanners are beginning to appear on the market at costs comparable to CT scanners. Primary differences in equipment for conventional NMR and NMR imaging are the much larger aperture magnets that are required for the examination of human subjects and the addition of coils to generate field gradients and facilities for manipulating the gradients. Early results from clinical trials in many parts of the world are encouraging, and in a few years, the usefuleness of this modality of medical imaging to the medical profession in diagnosis and treatment of disease will be defined. 10 figures

  13. Lanthanide paramagnetic probes for NMR spectroscopic studies of fast molecular conformational dynamics and temperature control. Effective six-site proton exchange in 18-crown-6 by exchange spectroscopy.

    Science.gov (United States)

    Babailov, Sergey P

    2012-02-06

    (1)H and (13)C NMR measurements are reported for the CDCl(3) and CD(2)Cl(2) solutions of [La(18-crown-6)(NO(3))(3)] (I), [Pr(18-crown-6) (NO(3))(3)] (II), [Ce(18-crown-6)(NO(3))(3)] (III), and [Nd(18-crown-6)(NO(3))(3)] (IV) complexes. Temperature dependencies of the (1)H NMR spectra of paramagnetic II-IV have been analyzed using the dynamic NMR (DNMR) methods for six-site exchange. Two types of conformational dynamic processes were identified (the first one is conditioned by interconversion of complex enantiomeric forms and pseudorotation of a macrocycle molecule upon the C(2) symmetry axis; the second one is conditioned by macrocycle molecule inversion). Application of exchange spectroscopy (2D-EXSY) of DNMR for investigation of this dynamic system (II-IV) simplifies the assignment of the NMR signals and represents the first experimental study of multisite exchange. In the present work, the methodology of paramagnetic 4f (Ce, Pr, and Nd) probe applications for the study of free-energy, enthalpy, and entropy changes in chemical exchange processes, as well as the advantages of this method in a comparison with DNMR studies of diamagnetic substances, is discussed. In particular, as a result of paramagnetic chemical shifts in 4f complexes, the range of measurable rate constants expands considerably compared to the analogous range in diamagnetic compounds. Coordination compounds investigated in the paper represent new types of thermometric NMR sensors and lanthanide paramagnetic probes for in situ temperature control in solution.

  14. Mechanism of adenylate kinase. Demonstration of a functional relationship between aspartate 93 and Mg2+ by site-directed mutagenesis and proton, phosphorus-31, and magnesium-25 NMR

    International Nuclear Information System (INIS)

    Yan, Honggao; Tsai, Mingdaw

    1991-01-01

    Earlier magnetic resonance studies suggested no direct interaction between Mg 2+ ions and adenylate kinase (AK) in the AK·MgATP (adenosine 5'-triphosphate) complex. However, recent NMR studies concluded that the carboxylate of aspartate 119 accepts a hydrogen bond from a water ligand of the bound Mg 2+ ion in the muscle AK · MgATP complex. On the other hand, in the 2.6-angstrom crystal structure of the yeast AK·MgAP 5 A [P 1 , P 5 -bis(5'-adenosyl)pentaphosphate] complex, the Mg 2+ ion is in proximity to aspartate 93. Substitution of Asp-93 with alanine resulted in no change in dissociation constants, 4-fold increases in K m , and a 650-fold decrease in k cat . Notable changes have been observed in the chemical shifts of the aromatic protons of histidine 36 and a few other aromatic residues. However, the results of detailed analyses of the free enzymes and the AK·MgAP 5 A complexes by one- and two-dimensional NMR suggested that the changes are due to localized perturbations. Thus it is concluded that Asp-93 stabilizes the transition state by ca. 3.9 kcal/mol. Other results raised the question of whether Mg 2+ could bind to D93A·nucleotide complexes, which was then probed by 25 MgNMR. The results suggest that Mg 2+ does bind to the D93A·AP 5 A complex, but possibly only weakly

  15. Lipid Dynamics Studied by Calculation of 31P Solid-State NMR Spectra Using Ensembles from Molecular Dynamics Simulations

    DEFF Research Database (Denmark)

    Hansen, Sara Krogh; Vestergaard, Mikkel; Thøgersen, Lea

    2014-01-01

    , for example, order parameters. Therefore, valuable insight into the dynamics of biomolecules may be achieved by the present method. We have applied this method to study the dynamics of lipid bilayers containing the antimicrobial peptide alamethicin, and we show that the calculated 31P spectra obtained...

  16. Comprehensive Metabolite Identification Strategy Using Multiple Two-Dimensional NMR Spectra of a Complex Mixture Implemented in the COLMARm Web Server

    Energy Technology Data Exchange (ETDEWEB)

    Bingol, Kerem [Environmental; Li, Da-Wei; Zhang, Bo; Brüschweiler, Rafael

    2016-12-06

    Identification of metabolites in complex mixtures represents a key step in metabolomics. A new strategy is introduced, which is implemented in a new public web server, COLMARm, that permits the co-analysis of up to three 2D NMR spectra, namely 13C-1H HSQC, 1H-1H TOCSY, and 13C-1H HSQC-TOCSY for the comprehensive, accurate, and efficient performance of this task. The highly versatile and interactive nature of COLMARm permits its application to a wide range of metabolomics samples independent of the magnetic field. Database query is performed using the HSQC spectrum and the top metabolite hits are then validated against the TOCSY-type experiment(s) by superimposing the expected cross-peaks on the mixture spectrum. In this way the user can directly accept or reject candidate metabolites by taking advantage of the complementary spectral information offered by these experiments and their different sensitivities. The power of COLMARm is demonstrated for a human serum sample uncovering the existence of 14 metabolites that hitherto were not identified by NMR.

  17. Facilitating quality control for spectra assignments of small organic molecules: nmrshiftdb2--a free in-house NMR database with integrated LIMS for academic service laboratories.

    Science.gov (United States)

    Kuhn, Stefan; Schlörer, Nils E

    2015-08-01

    nmrshiftdb2 supports with its laboratory information management system the integration of an electronic lab administration and management into academic NMR facilities. Also, it offers the setup of a local database, while full access to nmrshiftdb2's World Wide Web database is granted. This freely available system allows on the one hand the submission of orders for measurement, transfers recorded data automatically or manually, and enables download of spectra via web interface, as well as the integrated access to prediction, search, and assignment tools of the NMR database for lab users. On the other hand, for the staff and lab administration, flow of all orders can be supervised; administrative tools also include user and hardware management, a statistic functionality for accounting purposes, and a 'QuickCheck' function for assignment control, to facilitate quality control of assignments submitted to the (local) database. Laboratory information management system and database are based on a web interface as front end and are therefore independent of the operating system in use. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Spin-echo based diagonal peak suppression in solid-state MAS NMR homonuclear chemical shift correlation spectra

    Science.gov (United States)

    Wang, Kaiyu; Zhang, Zhiyong; Ding, Xiaoyan; Tian, Fang; Huang, Yuqing; Chen, Zhong; Fu, Riqiang

    2018-02-01

    The feasibility of using the spin-echo based diagonal peak suppression method in solid-state MAS NMR homonuclear chemical shift correlation experiments is demonstrated. A complete phase cycling is designed in such a way that in the indirect dimension only the spin diffused signals are evolved, while all signals not involved in polarization transfer are refocused for cancellation. A data processing procedure is further introduced to reconstruct this acquired spectrum into a conventional two-dimensional homonuclear chemical shift correlation spectrum. A uniformly 13C, 15N labeled Fmoc-valine sample and the transmembrane domain of a human protein, LR11 (sorLA), in native Escherichia coli membranes have been used to illustrate the capability of the proposed method in comparison with standard 13C-13C chemical shift correlation experiments.

  19. Oxygen isotope effect in 55Mn and 95Mo NMR spectra of the permanganate and molybdate ion

    International Nuclear Information System (INIS)

    Buckler, K.U.; Haase, A.R.; Lutz, O.; Mueller, M.; Nolle, A.

    1977-01-01

    By Fourier transform NMR spectroscopy the 55 Mn and 95 Mo resonance lines in the different permanganate and molybdate species Mn 16 Osub(4-n) 18 Osub(n) - and Mo 16 Osub(4-n) 18 Osub(n) 2- (n = 0,1,2,3,4) have been resolved in aqueous solutions of potassium permanganate and sodium molybdate. An isotopic effect on the Larmor frequency for 55 Mn of (0.59+-0.02)ppm and for 95 Mo of (0.25+-0.01)ppm to lower frequency has been found for the substitution of one 16 O atom by one 18 O atom. The relaxation rates 1/T 1 of 55 Mn in the different lines of the permanganate solution are equal within the limits of error. The oxygen exchange rate for the water-permanganate system has been evaluated. (orig.) [de

  20. Experimental diagnostics and modeling of inductive phenomena at low frequencies in impedance spectra of proton exchange membrane fuel cells

    Science.gov (United States)

    Pivac, Ivan; Šimić, Boris; Barbir, Frano

    2017-10-01

    Representation of fuel cell processes by equivalent circuit models, involving resistance and capacitance elements representing activation losses on both anode and cathode in series with resistance representing ohmic losses, cannot capture and explain the inductive loop that may show up at low frequencies in Nyquist diagram representation of the electrochemical impedance spectra. In an attempt to explain the cause of the low-frequency inductive loop and correlate it with the processes within the fuel cell electrodes, a novel equivalent circuit model of a Proton Exchange Membrane (PEM) fuel cell has been proposed and experimentally verified here in detail. The model takes into account both the anode and the cathode, and has an additional resonant loop on each side, comprising of a resistance, capacitance and inductance in parallel representing the processes within the catalyst layer. Using these additional circuit elements, more accurate and better fits to experimental impedance data in the wide frequency range at different current densities, cell temperatures, humidity of gases, air flow stoichiometries and backpressures were obtained.

  1. Proton detection for signal enhancement in solid-state NMR experiments on mobile species in membrane proteins

    Energy Technology Data Exchange (ETDEWEB)

    Ward, Meaghan E.; Ritz, Emily [University of Guelph, Department of Physics (Canada); Ahmed, Mumdooh A. M. [Suez University, The Department of Physics, Faculty of Science (Egypt); Bamm, Vladimir V.; Harauz, George [University of Guelph, Biophysics Interdepartmental Group (Canada); Brown, Leonid S.; Ladizhansky, Vladimir, E-mail: vladizha@uoguelph.ca [University of Guelph, Department of Physics (Canada)

    2015-12-15

    Direct proton detection is becoming an increasingly popular method for enhancing sensitivity in solid-state nuclear magnetic resonance spectroscopy. Generally, these experiments require extensive deuteration of the protein, fast magic angle spinning (MAS), or a combination of both. Here, we implement direct proton detection to selectively observe the mobile entities in fully-protonated membrane proteins at moderate MAS frequencies. We demonstrate this method on two proteins that exhibit different motional regimes. Myelin basic protein is an intrinsically-disordered, peripherally membrane-associated protein that is highly flexible, whereas Anabaena sensory rhodopsin is composed of seven rigid transmembrane α-helices connected by mobile loop regions. In both cases, we observe narrow proton linewidths and, on average, a 10× increase in sensitivity in 2D insensitive nuclear enhancement of polarization transfer-based HSQC experiments when proton detection is compared to carbon detection. We further show that our proton-detected experiments can be easily extended to three dimensions and used to build complete amino acid systems, including sidechain protons, and obtain inter-residue correlations. Additionally, we detect signals which do not correspond to amino acids, but rather to lipids and/or carbohydrates which interact strongly with membrane proteins.

  2. NMR Characterization of Flavanone Naringenin 7-O-Glycoside Diastereomer

    Directory of Open Access Journals (Sweden)

    SUN Li-juan

    2017-12-01

    Full Text Available To discriminate R and S flavanone glycoside using NMR, the mixture of R and S naringenin 7-O-glycoside was first isolated from Gleditsia sinensis. 1H and 13C NMR data of the mixture were recorded with 1H NMR, 13C NMR, 1H-1H COSY, 1H-13C HSQC and 1H-13C HMBC in DMSO-d6 solution. The two diastereomers were then separated with chiral chromatographic isolation, with their absolute configurations determined by circular dichroism. To avoid the disturbance of protons from glucose residues to dihydroflavonoid, 1H NMR spectra were acquired for pure R and S naringenin 7-O-glycoside and their mixture in CD3CN. The two diastereomers showed the largest proton chemical shift differences at the end group of glucose residue (H-1" with a chemical shift difference of 9.4 Hz. The OH-5 proton showed a chemical shift difference of 5.8 Hz. The chemical shift of the three protons on ring C were all influenced by configuration.

  3. Pressure effect of the 1H NMR spectra of organic compounds in the presence of lanthanide shift reagents. A formally associative process characterized by volume expansion

    International Nuclear Information System (INIS)

    Schulman, E.M.; Cheung, C.K.; Merbach, A.E.; Yamada, H.; le Noble, W.J.

    1987-01-01

    Following the successful application of hydrostatic pressure in mechanistic investigations of organic reactions, chemists have launched a vigorous effort to apply this tool to substitution reactions of coordination compounds. The authors began to study pressure effects in the NMR spectra of keton-lanthanide combination with the hope that the increase shifts anticipated might enhance the utility of the method, perhaps even expand its applicability to new classes of compounds. 5-Phenyl- and 5-tert-butyladamantan-2-one, piperidine, tetrahydrofuran, and cyclopentanol exhibited pressure-reduced lanthanide-induced shifts with Eu(fod) 3 ; Yb(fob) 3 and the shielding reagent Pr(fod) 3 showed the same effect with adamantanone. Solvent variations (CD 2 Cl 2 , CCl 4 ) caused minor changes in the magnitude of these shifts but did not reverse any. With the objective of learning whether these effects are due to a suppressed equilibrium population or to a reduction in the bound shift of the complex, they measured the spectra for a series or equimolar solutions of adamantanone and Eu(fod) 3 in CDCl 3 and used the Bouquant-Chuche equation to calculate both. Reasonable agreement with known atmosphere pressure data was obtained

  4. Data from mass spectrometry, NMR spectra, GC–MS of fatty acid esters produced by Lasiodiplodia theobromae

    Directory of Open Access Journals (Sweden)

    Carla C. Uranga

    2016-09-01

    Full Text Available The data described herein is related to the article with the title “Fatty acid esters produced by Lasiodiplodia theobromae function as growth regulators in tobacco seedlings” C.C. Uranga, J. Beld, A. Mrse, I. Cordova-Guerrero, M.D. Burkart, R. Hernandez-Martinez (2016 [1]. Data includes nuclear magnetic resonance spectroscopy and GC–MS data used for the identification and characterization of fatty acid esters produced by L. theobromae. GC–MS traces are also shown for incubations in defined substrate, consisting in Vogel׳s salts supplemented with either 5% grapeseed oil or 5% glucose, the two combined, or 5% fructose. Traces for incubations in the combination of 5% grapeseed oil and 5% glucose for different fungal species are also included. Images of mycelium morphology when grown in 5% glucose with or without 5% grapeseed oil are shown due to the stark difference in mycelial pigmentation in the presence of triglycerides. High concentration gradient data for the plant model Nicotiana tabacum germinated in ethyl stearate (SAEE and ethyl linoleate (LAEE is included to show the transition between growth inhibition and growth induction in N. tabacum by these compounds. Keywords: NMR, GC–MS, Fatty acid esters, Ethyl stearate, Ethyl linoleate, Growth inhibition, Growth induction

  5. An experiment to measure the spectra of primary proton, helium and iron nuclei at the 'knee' region at a high altitude

    CERN Document Server

    Xu, X W; Ding, L K; Zhang, C S; Ohnishi, M

    2003-01-01

    The possibility of measuring the energy spectra of some single elements (proton, helium and iron) in primary cosmic rays at the 'knee' energies, by setting up an air shower (AS) core detector in the AS gamma array (4300 m a.s.l., Tibet, China) is investigated. Taking into account the sensitivity and the acceptance needed for this measurement, the feasibility of construction and operation of the apparatus at a high altitude, and the cost, it is shown that this aim can be achieved by a simple AS core detector that mainly measures the high-energy electromagnetic components in AS cores. In this paper, such a detector is described. With a three-year exposure, proton, helium and iron spectra at the 'knee' energy region can be obtained with three event samples selected by an artificial neural network (ANN).

  6. Proton transfer in a short hydrogen bond caused by solvation shell fluctuations: an ab initio MD and NMR/UV study of an (OHO)(-) bonded system.

    Science.gov (United States)

    Pylaeva, Svetlana; Allolio, Christoph; Koeppe, Benjamin; Denisov, Gleb S; Limbach, Hans-Heinrich; Sebastiani, Daniel; Tolstoy, Peter M

    2015-02-14

    We present a joint experimental and quantum chemical study on the influence of solvent dynamics on the protonation equilibrium in a strongly hydrogen bonded phenol-acetate complex in CD2Cl2. Particular attention is given to the correlation of the proton position distribution with the internal conformation of the complex itself and with fluctuations of the aprotic solvent. Specifically, we have focused on a complex formed by 4-nitrophenol and tetraalkylammonium-acetate in CD2Cl2. Experimentally we have used combined low-temperature (1)H and (13)C NMR and UV-vis spectroscopy and showed that a very strong OHO hydrogen bond is formed with proton tautomerism (PhOH···(-)OAc and PhO(-)···HOAc forms, both strongly hydrogen bonded). Computationally, we have employed ab initio molecular dynamics (70 and 71 solvent molecules, with and without the presence of a counter-cation, respectively). We demonstrate that the relative motion of the counter-cation and the "free" carbonyl group of the acid plays the major role in the OHO bond geometry and causes proton "jumps", i.e. interconversion of PhOH···(-)OAc and PhO(-)···HOAc tautomers. Weak H-bonds between CH(CD) groups of the solvent and the oxygen atom of carbonyl stabilize the PhOH···(-)OAc type of structures. Breaking of CH···O bonds shifts the equilibrium towards PhO(-)···HOAc form.

  7. Compact NMR

    Energy Technology Data Exchange (ETDEWEB)

    Bluemich, Bernhard; Haber-Pohlmeier, Sabina; Zia, Wasif [RWTH Aachen Univ. (Germany). Inst. fuer Technische und Makromolekulare Chemie (ITMC)

    2014-06-01

    Nuclear Magnetic Resonance (NMR) spectroscopy is the most popular method for chemists to analyze molecular structures, while Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool for medical doctors that provides high-contrast images of biological tissue. In both applications, the sample (or patient) is positioned inside a large, superconducting magnet to magnetize the atomic nuclei. Interrogating radio-frequency pulses result in frequency spectra that provide the chemist with molecular information, the medical doctor with anatomic images, and materials scientist with NMR relaxation parameters. Recent advances in magnet technology have led to a variety of small permanent magnets to allow compact and low-cost instruments. The goal of this book is to provide an introduction to the practical use of compact NMR at a level nearly as basic as the operation of a smart phone.

  8. A modified strategy for sequence specific assignment of protein NMR spectra based on amino acid type selective experiments

    International Nuclear Information System (INIS)

    Schubert, Mario; Labudde, Dirk; Leitner, Dietmar; Oschkinat, Hartmut; Schmieder, Peter

    2005-01-01

    The determination of the three-dimensional structure of a protein or the study of protein-ligand interactions requires the assignment of all relevant nuclei as an initial step. This is nowadays almost exclusively performed using triple-resonance experiments. The conventional strategy utilizes one or more pairs of three dimensional spectra to obtain redundant information and thus reliable assignments. Here, a modified strategy for obtaining sequence specific assignments based on two dimensional amino acid type selective triple-resonance experiments is proposed. These experiments can be recorded with good resolution in a relatively short time. They provide very specific and redundant information, in particular on sequential connectivities, that drastically increases the ease and reliability of the assignment procedure, done either manually or in an automated fashion. The new strategy is demonstrated with the protein domain PB1 from yeast CDC24p

  9. Complex methyl groups dynamics in [(CH3)4P]3Sb2Br9 (PBA) from low to high temperatures by proton spin-lattice relaxation and narrowing of proton NMR spectrum.

    Science.gov (United States)

    Latanowicz, L; Medycki, W; Jakubas, R

    2009-11-01

    Molecular dynamics of a polycrystalline sample of [(CH(3))(4)P](3)Sb(2)Br(9) (PBA) has been studied on the basis of the T(1) (24.7 MHz) relaxation time measurement, the proton second moment of NMR and the earlier published T(1) (90 MHz) relaxation times. The study was performed in a wide range of temperatures (30-337 K). The tunnel splitting omega(T) of the methyl groups was estimated as of low frequency (from kHz to few MHz). The proton spin pairs of the methyl group are known to perform a complex internal motion being a resultant of four components. Three of them involve mass transportation over and through the potential barrier and are characterized by the correlation times tau(3) and tau(T)of the jumps over the barrier and tunnel jumps in the threefold potential of the methyl group and tau(iso) the correlation time of isotropic rotation of the whole TMP cation. For tau(3) and tau(iso) the Arrhenius temperature dependence was assumed, while for tau(T)--the Schrödinger one. The fourth motion causes fluctuations of the tunnel splitting frequency, omega(T), and it is related to the lifetime of the methyl spin at the energy level. The correlation function for this fourth motion (tau(omega) correlation time) has been proposed by Müller-Warmuth et al. In this paper a formula for the correlation function and spectral density of the complex motion made of the above-mentioned four components was derived and used in interpretation of the T(1) relaxation time. The second moment of proton NMR line at temperatures below 50K is four times lower than its value for the rigid structure. The three components of the internal motion characterized by tau(T), tau(H), and tau(iso) were proved to reduce the second moment of the NMR line. The tunnel jumps of the methyl group reduce M(2) at almost 0K, the classical jumps over the barrier reduce M(2) in the vicinity of 50K, while the isotropic motion near 150K. Results of the study on the dynamics of CH(3) groups of TMP cation based on

  10. Apparatus for rapid adjustment of the degree of alignment of NMR samples in aqueous media: verification with residual quadrupolar splittings in (23)Na and (133)Cs spectra.

    Science.gov (United States)

    Kuchel, Philip W; Chapman, Bogdan E; Müller, Norbert; Bubb, William A; Philp, David J; Torres, Allan M

    2006-06-01

    NMR spectra of (23)Na(+) and (133)Cs(+) in gelatine in a silicone rubber tube that was stretched to various extents showed remarkably reproducible resonance multiplicity. The relative intensities of the components of the split peaks had ratios, 3:4:3, and 7:12:15:16:15:12:7, respectively, that conformed with those predicted using a Mathematica program. The silicone-rubber tube was sealed at its lower end by a small rubber stopper and placed inside a thick-walled glass tube. Gelatine was injected in solution into the silicone tube and 'set' by cooling below 30 degrees C. A plastic thumb-screw held the silicone tube at various degrees of extension, up to approximately 2-fold. After constituting the gel in buffers containing NaCl and CsCl, both (23)Na and (133)Cs NMR spectroscopy revealed that after stretching the initial single Lorentzian line was split into a well-resolved triplet and a heptet, respectively. This was interpreted as being due to coupling between the electric quadrupoles of the nuclei and the average electric field gradient tensor of the collagen molecules of gelatine; these molecules became progressively more aligned in the direction of the main magnetic field, B(0), of the vertical bore magnet, as the gel was stretched. This apparatus provides a simple way of demonstrating fundamental physical characteristics of quadrupolar cations, some characteristics of gelatine under stretching, and a way to invoke static distortion of red blood cells. It should be useful with these and other cell types, for studies of metabolic and membrane transport characteristics that may change when the cells are distorted, and possibly for structural studies of macromolecules.

  11. Proton spectra from 6.3 GeV/c deuteron break-up on H, D, C, Al and Bi nuclei

    International Nuclear Information System (INIS)

    Azhgirey, L.S.; Ignatenko, M.A.; Ivanov, V.V.; Kuznetsov, A.S.; Mescheryakov, M.G.; Razin, S.V.; Stoletov, G.D.; Vzorov, I.K.; Zhmyrov, V.N.

    1977-01-01

    The proton spectra from deuteron break-up on H, D, 12 C, 27 Al and 209 Bi nuclei were measured at an angle of 103 mrad (lab. system) in the momentum interval from 2.6 to 3.6 GeV/c. The measurements were made at the JINR synchrophasotron by one-arm magnetic spectrometer on-line with a computer. The extracted 6.3 GeV/c deuteron beam was incident on targets of CH 2 , CD 2 , C, Al and Bi at the thickness from 0.8 to 2 g/cm 2 . The flux of deuteron beam was equal to 5x10 8 -5x10 9 particles/pulse with a typical pulse length of 300 ms. The repetition rate was one pulse every 10 s. Proton peaks with the maximum at about 3.1 GeV/c and 280-300 MeV/c FWHM dominate in all the measured spectra. Experimental proton spectra are compared with calculations with the Reid, the Moravcsik Gartenhaus, the Hulten and the Gauss wave functions. The results, on the whole, are reasonably reproduced in the framework of the Glauber multiple scattering model taking into account the relativistic deformation of the deuteron wave function

  12. 1H NMR spectra of vertebrate [2Fe-2S] ferredoxins. Hyperfine resonances suggest different electron delocalization patterns from plant ferredoxins

    International Nuclear Information System (INIS)

    Skjeldal, L.; Markley, J.L.; Coghlan, V.M.; Vickery, L.E.

    1991-01-01

    The authors report the observation of paramagnetically shifted (hyperfine) proton resonances from vertebrate mitochondrial [2Fe-2S] ferredoxins. The hyperfine signals of human, bovine, and chick [2Fe-2S] ferredoxins are described and compared with those of Anabena 7120 vegetative ferredoxin, a plant-type [2Fe-2S] ferredoxin studied previously. The hyperfine resonances of the three vertebrate ferredoxins were very similar to one another both in the oxidized state and in the reduced state, and slow (on the NMR scale) electron self-exchange was observed in partially reduced samples. For the oxidized vertebrate ferredoxins, hyperfine signals were observed downfield of the diamagnetic envelope from +13 to +50 ppm, and the general pattern of peaks and their anti-Curie temperature dependence are similar to those observed for the oxidized plant-type ferredoxins. For the reduced vertebrate ferredoxins, hyperfine signals were observed for the oxidized plant-type ferredoxins. For the reduced vertebrate ferredoxins, hyperfine signals were observed both upfield (-2 to -18 ppm) and downfield (+15 to +45 ppm), and all were found to exhibit Curie-type temperature dependence. These results indicate that the contact-shifted resonances in the reduced vertebrate ferredoxins detect different spin magnetization from those in the reduced plant ferredoxins and suggest that plant and vertebrate ferredoxins have fundamentally different patterns of electron delocalization in the reduced [2Fe-2S] center

  13. Two-dimensional NMR studies of squash family inhibitors. Sequence-specific proton assignments and secondary structure of reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III.

    Science.gov (United States)

    Krishnamoorthi, R; Gong, Y X; Lin, C L; VanderVelde, D

    1992-01-28

    The solution structure of reactive-site hydrolyzed Cucurbita maxima trypsin inhibitor III (CMTI-III*) was investigated by two-dimensional proton nuclear magnetic resonance (2D NMR) spectroscopy. CMTI-III*, prepared by reacting CMTI-III with trypsin which cleaved the Arg5-Ile6 peptide bond, had the two fragments held together by a disulfide linkage. Sequence-specific 1H NMR resonance assignments were made for all the 29 amino acid residues of the protein. The secondary structure of CMTI-III*, as deduced from NOESY cross peaks and identification of slowly exchanging hydrogens, contains two turns (residues 8-12 and 24-27), a 3(10)-helix (residues 13-16), and a triple-stranded beta-sheet (residues 8-10, 29-27, and 21-25). This secondary structure is similar to that of CMTI-I [Holak, T. A., Gondol, D., Otlewski, J., & Wilusz, T. (1989) J. Mol. Biol. 210, 635-648], which has a Glu instead of a Lys at position 9. Sequential proton assignments were also made for the virgin inhibitor, CMTI-III, at pH 4.71, 30 degrees C. Comparison of backbone hydrogen chemical shifts of CMTI-III and CMTI-III* revealed significant changes for residues located far away from the reactive-site region as well as for those located near it, indicating tertiary structural changes that are transmitted through most of the 29 residues of the inhibitor protein. Many of these residues are functionally important in that they make contact with atoms of the enzyme in the trypsin-inhibitor complex, as revealed by X-ray crystallography [Bode, W., Greyling, H. J., Huber, R., Otlewski, J., & Wilusz, T. (1989) FEBS Lett. 242, 285-292].(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Characterizing source fingerprints and ageing processes in laboratory-generated secondary organic aerosols using proton-nuclear magnetic resonance (1H-NMR) analysis and HPLC HULIS determination

    Science.gov (United States)

    Zanca, Nicola; Lambe, Andrew T.; Massoli, Paola; Paglione, Marco; Croasdale, David R.; Parmar, Yatish; Tagliavini, Emilio; Gilardoni, Stefania; Decesari, Stefano

    2017-09-01

    The study of secondary organic aerosol (SOA) in laboratory settings has greatly increased our knowledge of the diverse chemical processes and environmental conditions responsible for the formation of particulate matter starting from biogenic and anthropogenic volatile compounds. However, characteristics of the different experimental setups and the way they impact the composition and the timescale of formation of SOA are still subject to debate. In this study, SOA samples were generated using a potential aerosol mass (PAM) oxidation flow reactor using α-pinene, naphthalene and isoprene as precursors. The PAM reactor facilitated exploration of SOA composition over atmospherically relevant photochemical ageing timescales that are unattainable in environmental chambers. The SOA samples were analyzed using two state-of-the-art analytical techniques for SOA characterization - proton nuclear magnetic resonance (1H-NMR) spectroscopy and HPLC determination of humic-like substances (HULIS). Results were compared with previous Aerodyne aerosol mass spectrometer (AMS) measurements. The combined 1H-NMR, HPLC, and AMS datasets show that the composition of the studied SOA systems tend to converge to highly oxidized organic compounds upon prolonged OH exposures. Further, our 1H-NMR findings show that only α-pinene SOA acquires spectroscopic features comparable to those of ambient OA when exposed to at least 1 × 1012 molec OH cm-3 × s OH exposure, or multiple days of equivalent atmospheric OH oxidation. Over multiple days of equivalent OH exposure, the formation of HULIS is observed in both α-pinene SOA and in naphthalene SOA (maximum yields: 16 and 30 %, respectively, of total analyzed water-soluble organic carbon, WSOC), providing evidence of the formation of humic-like polycarboxylic acids in unseeded SOA.

  15. Characterizing source fingerprints and ageing processes in laboratory-generated secondary organic aerosols using proton-nuclear magnetic resonance (1H-NMR analysis and HPLC HULIS determination

    Directory of Open Access Journals (Sweden)

    N. Zanca

    2017-09-01

    Full Text Available The study of secondary organic aerosol (SOA in laboratory settings has greatly increased our knowledge of the diverse chemical processes and environmental conditions responsible for the formation of particulate matter starting from biogenic and anthropogenic volatile compounds. However, characteristics of the different experimental setups and the way they impact the composition and the timescale of formation of SOA are still subject to debate. In this study, SOA samples were generated using a potential aerosol mass (PAM oxidation flow reactor using α-pinene, naphthalene and isoprene as precursors. The PAM reactor facilitated exploration of SOA composition over atmospherically relevant photochemical ageing timescales that are unattainable in environmental chambers. The SOA samples were analyzed using two state-of-the-art analytical techniques for SOA characterization – proton nuclear magnetic resonance (1H-NMR spectroscopy and HPLC determination of humic-like substances (HULIS. Results were compared with previous Aerodyne aerosol mass spectrometer (AMS measurements. The combined 1H-NMR, HPLC, and AMS datasets show that the composition of the studied SOA systems tend to converge to highly oxidized organic compounds upon prolonged OH exposures. Further, our 1H-NMR findings show that only α-pinene SOA acquires spectroscopic features comparable to those of ambient OA when exposed to at least 1  ×  1012 molec OH cm−3  ×  s OH exposure, or multiple days of equivalent atmospheric OH oxidation. Over multiple days of equivalent OH exposure, the formation of HULIS is observed in both α-pinene SOA and in naphthalene SOA (maximum yields: 16 and 30 %, respectively, of total analyzed water-soluble organic carbon, WSOC, providing evidence of the formation of humic-like polycarboxylic acids in unseeded SOA.

  16. Correcting human heart 31P NMR spectra for partial saturation. Evidence that saturation factors for PCr/ATP are homogeneous in normal and disease states

    Science.gov (United States)

    Bottomley, Paul A.; Hardy, Christopher J.; Weiss, Robert G.

    Heart PCr/ATP ratios measured from spatially localized 31P NMR spectra can be corrected for partial saturation effects using saturation factors derived from unlocalized chest surface-coil spectra acquired at the heart rate and approximate Ernst angle for phosphor creatine (PCr) and again under fully relaxed conditions during each 31P exam. To validate this approach in studies of normal and disease states where the possibility of heterogeneity in metabolite T1 values between both chest muscle and heart and normal and disease states exists, the properties of saturation factors for metabolite ratios were investigated theoretically under conditions applicable in typical cardiac spectroscopy exams and empirically using data from 82 cardiac 31P exams in six study groups comprising normal controls ( n = 19) and patients with dilated ( n = 20) and hypertrophic ( n = 5) cardiomyopathy, coronary artery disease ( n = 16), heart transplants ( n = 19), and valvular heart disease ( n = 3). When TR ≪ T1,(PCr), with T1(PCr) ⩾ T1(ATP), the saturation factor for PCr/ATP lies in the range 1.5 ± 0.5, regardless of the T1 values. The precise value depends on the ratio of metabolite T1 values rather than their absolute values and is insensitive to modest changes in TR. Published data suggest that the metabolite T1 ratio is the same in heart and muscle. Our empirical data reveal that the saturation factors do not vary significantly with disease state, nor with the relative fractions of muscle and heart contributing to the chest surface-coil spectra. Also, the corrected myocardial PCr/ATP ratios in each normal or disease state bear no correlation with the corresponding saturation factors nor the fraction of muscle in the unlocalized chest spectra. However, application of the saturation correction (mean value, 1.36 ± 0.03 SE) significantly reduced scatter in myocardial PCr/ATP data by 14 ± 11% (SD) ( p ⩽ 0.05). The findings suggest that the relative T1 values of PCr and ATP are

  17. A scintillator-based online detector for the angularly resolved measurement of laser-accelerated proton spectra

    International Nuclear Information System (INIS)

    Metzkes, J.; Kraft, S. D.; Sobiella, M.; Stiller, N.; Zeil, K.; Schramm, U.; Karsch, L.; Schürer, M.; Pawelke, J.; Richter, C.

    2012-01-01

    In recent years, a new generation of high repetition rate (∼10 Hz), high power (∼100 TW) laser systems has stimulated intense research on laser-driven sources for fast protons. Considering experimental instrumentation, this development requires online diagnostics for protons to be added to the established offline detection tools such as solid state track detectors or radiochromic films. In this article, we present the design and characterization of a scintillator-based online detector that gives access to the angularly resolved proton distribution along one spatial dimension and resolves 10 different proton energy ranges. Conceived as an online detector for key parameters in laser-proton acceleration, such as the maximum proton energy and the angular distribution, the detector features a spatial resolution of ∼1.3 mm and a spectral resolution better than 1.5 MeV for a maximum proton energy above 12 MeV in the current design. Regarding its areas of application, we consider the detector a useful complement to radiochromic films and Thomson parabola spectrometers, capable to give immediate feedback on the experimental performance. The detector was characterized at an electrostatic Van de Graaff tandetron accelerator and tested in a laser-proton acceleration experiment, proving its suitability as a diagnostic device for laser-accelerated protons.

  18. A scintillator-based online detector for the angularly resolved measurement of laser-accelerated proton spectra.

    Science.gov (United States)

    Metzkes, J; Karsch, L; Kraft, S D; Pawelke, J; Richter, C; Schürer, M; Sobiella, M; Stiller, N; Zeil, K; Schramm, U

    2012-12-01

    In recent years, a new generation of high repetition rate (~10 Hz), high power (~100 TW) laser systems has stimulated intense research on laser-driven sources for fast protons. Considering experimental instrumentation, this development requires online diagnostics for protons to be added to the established offline detection tools such as solid state track detectors or radiochromic films. In this article, we present the design and characterization of a scintillator-based online detector that gives access to the angularly resolved proton distribution along one spatial dimension and resolves 10 different proton energy ranges. Conceived as an online detector for key parameters in laser-proton acceleration, such as the maximum proton energy and the angular distribution, the detector features a spatial resolution of ~1.3 mm and a spectral resolution better than 1.5 MeV for a maximum proton energy above 12 MeV in the current design. Regarding its areas of application, we consider the detector a useful complement to radiochromic films and Thomson parabola spectrometers, capable to give immediate feedback on the experimental performance. The detector was characterized at an electrostatic Van de Graaff tandetron accelerator and tested in a laser-proton acceleration experiment, proving its suitability as a diagnostic device for laser-accelerated protons.

  19. Absolute nutrient concentration measurements in cell culture media: 1H q-NMR spectra and data to compare the efficiency of pH-controlled protein precipitation versus CPMG or post-processing filtering approaches

    Directory of Open Access Journals (Sweden)

    Luca Goldoni

    2016-09-01

    Full Text Available The NMR spectra and data reported in this article refer to the research article titled “A simple and accurate protocol for absolute polar metabolite quantification in cell cultures using q-NMR” [1]. We provide the 1H q-NMR spectra of cell culture media (DMEM after removal of serum proteins, which show the different efficiency of various precipitating solvents, the solvent/DMEM ratios, and pH of the solution. We compare the data of the absolute nutrient concentrations, measured by PULCON external standard method, before and after precipitation of serum proteins and those obtained using CPMG (Carr-Purcell-Meiboom-Gill sequence or applying post-processing filtering algorithms to remove, from the 1H q-NMR spectra, the proteins signal contribution. For each of these approaches, the percent error in the absolute value of every measurement for all the nutrients is also plotted as accuracy assessment. Keywords: 1H NMR, pH-controlled serum removal, PULCON, Accuracy, CPMG, Deconvolution

  20. Two-dimensional 1H and 31P NMR spectra and restrained molecular dynamics structure of an oligodeoxyribonucleotide duplex refined via a hybrid relaxation matrix procedure

    International Nuclear Information System (INIS)

    Powers, R.; Jones, C.R.; Gorenstein, D.G.

    1990-01-01

    Assignment of the 1H and 31P resonances of a decamer DNA duplex, d(CGCTTAAGCG)2 was determined by two-dimensional COSY, NOESY and 1H-31P Pure Absorption phase Constant time (PAC) heteronuclear correlation spectroscopy. The solution structure of the decamer was calculated by an iterative hybrid relaxation matrix method combined with NOESY-distance restrained molecular dynamics. The distances from the 2D NOESY spectra were calculated from the relaxation rate matrix which were evaluated from a hybrid NOESY volume matrix comprising elements from the experiment and those calculated from an initial structure. The hybrid matrix-derived distances were then used in a restrained molecular dynamics procedure to obtain a new structure that better approximates the NOESY spectra. The resulting partially refined structure was then used to calculate an improved theoretical NOESY volume matrix which is once again merged with the experimental matrix until refinement is complete. JH3'-P coupling constants for each of the phosphates of the decamer were obtained from 1H-31P J-resolved selective proton flip 2D spectra. By using a modified Karplus relationship the C4'-C3'-O3'-P torsional angles were obtained. Comparison of the 31P chemical shifts and JH3'-P coupling constants of this sequence has allowed a greater insight into the various factors responsible for 31P chemical shift variations in oligonucleotides. It also provides an important probe of the sequence-dependent structural variation of the deoxyribose phosphate backbone of DNA in solution. These correlations are consistent with the hypothesis that changes in local helical structure perturb the deoxyribose phosphate backbone. The variation of the 31P chemical shift, and the degree of this variation from one base step to the next is proposed as a potential probe of local helical conformation within the DNA double helix

  1. Temperature dependence of (+)-catechin pyran ring proton coupling constants as measured by NMR and modeled using GMMX search methodology

    Science.gov (United States)

    Fred L. Tobiason; Stephen S. Kelley; M. Mark Midland; Richard W. Hemingway

    1997-01-01

    The pyran ring proton coupling constants for (+)-catechin have been experimentally determined in deuterated methanol over a temperature range of 213 K to 313 K. The experimental coupling constants were simulated to 0.04 Hz on the average at a 90 percent confidence limit using a LAOCOON method. The temperature dependence of the coupling constants was reproduced from the...

  2. MRI Proton Density Fat Fraction Is Robust Across the Biologically Plausible Range of Triglyceride Spectra in Adults With Nonalcoholic Steatohepatitis

    Science.gov (United States)

    Hong, Cheng William; Mamidipalli, Adrija; Hooker, Jonathan C.; Hamilton, Gavin; Wolfson, Tanya; Chen, Dennis H.; Dehkordy, Soudabeh Fazeli; Middleton, Michael S.; Reeder, Scott B.; Loomba, Rohit; Sirlin, Claude B.

    2017-01-01

    Background Proton density fat fraction (PDFF) estimation requires spectral modeling of the hepatic triglyceride (TG) signal. Deviations in the TG spectrum may occur, leading to bias in PDFF quantification. Purpose To investigate the effects of varying six-peak TG spectral models on PDFF estimation bias. Study Type Retrospective secondary analysis of prospectively acquired clinical research data. Population Forty-four adults with biopsy-confirmed nonalcoholic steatohepatitis. Field Strength/Sequence Confounder-corrected chemical-shift-encoded 3T MRI (using a 2D multiecho gradient-recalled echo technique with magnitude reconstruction) and MR spectroscopy. Assessment In each patient, 61 pairs of colocalized MRI-PDFF and MRS-PDFF values were estimated: one pair used the standard six-peak spectral model, the other 60 were six-peak variants calculated by adjusting spectral model parameters over their biologically plausible ranges. MRI-PDFF values calculated using each variant model and the standard model were compared, and the agreement between MRI-PDFF and MRS-PDFF was assessed. Statistical Tests MRS-PDFF and MRI-PDFF were summarized descriptively. Bland–Altman (BA) analyses were performed between PDFF values calculated using each variant model and the standard model. Linear regressions were performed between BA biases and mean PDFF values for each variant model, and between MRI-PDFF and MRS-PDFF. Results Using the standard model, mean MRS-PDFF of the study population was 17.9±8.0% (range: 4.1–34.3%). The difference between the highest and lowest mean variant MRI-PDFF values was 1.5%. Relative to the standard model, the model with the greatest absolute BA bias overestimated PDFF by 1.2%. Bias increased with increasing PDFF (P hepatic fat content, PDFF estimation is robust across the biologically plausible range of TG spectra. Although absolute estimation bias increased with higher PDFF, its magnitude was small and unlikely to be clinically meaningful. Level of

  3. FTIR, FT-RAMAN, NMR, spectra, normal co-ordinate analysis, NBO, NLO and DFT calculation of N,N-diethyl-4-methylpiperazine-1-carboxamide molecule.

    Science.gov (United States)

    Muthu, S; Elamurugu Porchelvi, E

    2013-11-01

    The Fourier Transform Infrared (FT-IR) and FT-Raman of N,N-diethyl-4-methylpiperazine-1-carboxamide (NND4MC) have been recorded and analyzed. The structure of the compound was optimized and the structural characteristics were determined by density functional theory (DFT) using B3LYP method with 6-31G(d,p) and 6-311G(d,p) basis sets. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The theoretically predicted FT-IR and FT-Raman spectra of the title molecule have been constructed. The detailed interpretation of the vibrational spectra has been carried out with aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that electron density (ED) in the σ(*) and π(*) antibonding orbitals and second order delocalization energies (E2) confirm the occurrence of intramolecular charge transfer (ICT) within the molecule. The electronic dipole moment (μD) and the first hyperpolarizability (βtot) values of the investigated molecule were computed using Density Functional Theory (DFT/B3LYP) with 6-31G(d,p) and 6-311G(d,p) basis sets. The calculated results also show that the NND4MC molecule may have microscopy nonlinear optical (NLO) behavior with non zero values. Mulliken atomic charges of NND4MC were calculated. The (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. The UV-Vis spectrum of the compound was recorded. The theoretical electronic absorption spectra have been calculated by using CIS, TD-DFT methods. A study on the electronic properties, such as HOMO and LUMO energies, molecular electrostatic potential (MEP) were also performed. Copyright © 2013 Elsevier B

  4. Transverse momentum spectra of charged particles in proton-proton collisions at $\\sqrt{s}$ = 900 GeV with ALICE at the LHC

    CERN Document Server

    Aamodt, K; Abeysekara, U; Abrahantes Quintana, A; Abramyan, A; Adamov, D; Aggarwal, M M; Aglieri Rinella, G; Agocs, A G; Aguilar Salazar, S; Ahammed, Z; Ahmad, A; Ahmad, N; Ahn, S U; Akimoto, R; Akindinov, A; Aleksandrov, D; Alessandro, B; Alfaro Molina, R; Alici, A; Almarz Avia, E; Alme, J; Alt, T; Altini, V; Altinpinar, S; Andrei, C; Andronic, A; Anelli, G; Angelov, V; Anson, C; Anticic, T; Antinori, F; Antinori, S; Antipin, K; Antonczyk, D; Antonioli, P; Anzo, A; Aphecetche, L; Appelshuser, H; Arcelli, S; Arceo, R; Arend, A; Armesto, N; Arnaldi, R; Aronsson, T; Arsene, I C; Asryan, A; Augustinus, A; AverbecK, R; Awes, T C; yst, J; Azmi, M D; Bablok, S; Bach, M; Badal, A; Baek, Y W; Bagnasco, S; Bailhache, R; Bala, R; Baldisseri, A; Baldit, A; Bn, J; Barbera, R; Barnafldi, G G; Barnby, L S; Barret, V; Bartke, J; Barile, F; Basile, M; Basmanov, V; Bastid, N; Bathen, B; Batigne, G; Batyunya, B; Baumann, C; Bearden, I G; Becker, B; Belikov, I; Bellwied, R; Belmont-Moreno, E; Belogianni, A; Benhabib, L; Beole, S; Berceanu, I; Bercuci, A; Berdermann, E; Berdnikov, Y; Betev, L; Bhasin, A; Bhati, A K; Bianchi, L; Bianchi, N; Bianchin, C; Bielck, J; Bielckov, J; Bilandzic, A; Bimbot, L; Biolcati, E; Blanc, A; Blanco, F; Blanco, F; Blau, D; Blume, C; Boccioli, M; Bock, N; Bogdanov, A; Bggild, H; Bogolyubsky, M; Bohm, J; Boldizsr, L; Bombara, M; Bombonati, C; Bondila, M; Borel, H; Borisov, A; Bortolin, C; Bose, S; Bosisio, L; Boss, F; Botje, M; Bttger, S; Bourdaud, G; Boyer, B; Braun, M; Braun-Munzinger, P; Bravina, L; Bregant, M; Breitner, T; Bruckner, G; Brun, R; Bruna, E; Bruno, G E; Budnikov, D; Buesching, H; Buncic, P; Busch, O; Buthelezi, Z; Caffarri, D; Cai, X; Caines, H; Calvo, E; Camacho, E; Camerini, P; Campbell, M; Canoa Roman, V; Capitani, G P; Cara Romeo, G; Carena, F; Carena, W; Carminati, F; Casanova Daz, A; Caselle, M; Castillo Castellanos, J; Castillo Hernandez, J F; Catanescu, V; Cattaruzza, E; Cavicchioli, C; Cerello, P; Chambert, V; Chang, B; Chapeland, S; Charpy, A; Charvet, J L; Chattopadhyay, S; Chattopadhyay, S; Cherney, M; Cheshkov, C; Cheynis, B; Chiavassa, E; Chibante Barroso, V; Chinellato, D D; Chochula, P; Choi, K; Chojnacki, M; Christakoglou, P; Christensen, C H; Christiansen, P; Chujo, T; Chuman, F; Cicalo, C; Cifarelli, L; Cindolo, F; Cleymans, J; Cobanoglu, O; Coffin, J P; Coli, S; Colla, A; Conesa Balbastre, G; Conesa del Valle, Z; Conner, E S; Constantin, P; Contin, G; Contreras, J G; Corrales Morales, Y; Cormier, T M; Cortese, P; Corts Maldonado, I; Cosentino, M R; Costa, F; Cotallo, M E; Crescio, E; Crochet, P; Cuautle, E; Cunqueiro, L; Cussonneau, J; Dainese, A; Dalsgaard, H H; Danu, A; Das, I; Dash, A; Dash, S; de Barros, G O V; De Caro, A; de Cataldo, G; de Cuveland, J; De Falco, A; De Gaspari, M; de Groot, J; De Gruttola, D; De Marco, N; De Pasquale, S; De Remigis, R; de Rooij, R; de Vaux, G; Delagrange, H; Delgado, Y; Dellacasa, G; Deloff, A; Demanov, V; Dnes, E; Deppman, A; D'Erasmo, G; Derkach, D; Devaux, A; Di Bari, D; Di Giglio, C; Di Liberto, S; Di Mauro, A; Di Nezza, P; Dialinas, M; Daz, L; Daz, R; Dietel, T; Divi, R; Djuvsland,; Dobretsov, V; Dobrin, A; Dobrowolski, T; Dnigus, B; Domnguez, I; Dordic, O; Dubey, A K; Dubuisson, J; Ducroux, L; Dupieux, P; Dutta Majumdar, A K; Dutta Majumdar, M R; Elia, D; Emschermann, D; Enokizono, A; Espagnon, B; Estienne, M; Esumi, S; Evans, D; Evrard, S; Eyyubova, G; Fabjan, C W; Fabris, D; Faivre, J; Falchieri, D; Fantoni, A; Fasel, M; Fateev, O; Fearick, R; Fedunov, A; Fehlker, D; Fekete, V; Felea, D; Fenton-Olsen, B; Feofilov, G; Fernndez Tllez, A; Ferreiro, E G; Ferretti, A; Ferretti, R; Figueredo, M A S; Filchagin, S; Fini, R; Fionda, F M; Fiore, E M; Floris, M; Fodor, Z; Foertsch, S; Foka, P; Fokin, S; Formenti, F; Fragiacomo, E; Fragkiadakis, M; Frankenfeld, U; Frolov, A; Fuchs, U; Furano, F; Furget, C; Fusco Girard, M; Gaardhje, J J; Gadrat, S; Gagliardi, M; Gago, A; Gallio, M; Ganoti, P; Ganti, M S; Garabatos, C; Garca Trapaga, C; Gebelein, J; Gemme, R; Germain, M; Gheata, A; Gheata, M; Ghidini, B; Ghosh, P; Giraudo, G; Giubellino, P; Gladysz-Dziadus, E; Glasow, R; Glssel, P; Glenn, A; Gomez Jimnez, R; Gonzlez Santos, H; Gonzlez-Trueba, L H; Gonzlez-Zamora, P; Gorbunov, S; Gorbunov, Y; Gotovac, S; Gottschlag, H; Grabski, V; Grajcarek, R; Grelli, A; Grigoras, A; Grigoras, C; Grigoriev, V; Grigoryan, A; Grigoryan, S; Grinyov, B; Grion, N; Gros, P; Grosse-Oetringhaus, J F; Grossiord, J Y; Grosso, R; Guber, F; Guernane, R; Guerra, C; Guerzoni, B; Gulbrandsen, K; Gulkanyan, H; Gunji, T; Gupta, A; Gupta, R; Gustafsson, H A; Gutbrod, H; Haaland,; Hadjidakis, C; Haiduc, M; Hamagaki, H; Hamar, G; Hamblen, J; Han, B H; Harris, J W; Hartig, M; Harutyunyan, A; Hasch, D; Hasegan, D; Hatzifotiadou, D; Hayrapetyan, A; Heide, M; Heinz, M; Helstrup, H; Herghelegiu, A; Hernndez, C; Herrera Corral, G; Herrmann, N; Hetland, K F; Hicks, B; Hiei, A; Hille, P T; Hippolyte, B; Horaguchi, T; Hori, Y; Hristov, P; Hrivncov, I; Hu, S; Huang, M; Huber, S; Humanic, T J; Hutter, D; Hwang, D S; Ichou, R; Ilkaev, R; Ilkiv, I; Inaba, M; Innocenti, P G; Ippolitov, M; Irfan, M; Ivan, C; Ivanov, A; Ivanov, M; Ivanov, V; Iwasaki, T; Jachokowski, A; Jacobs, P; Jancurov, L; Jangal, S; Janik, R; Jena, C; Jena, S; Jirden, L; Jones, G T; Jones, P G; Jovanovic, P; Jung, H; Jung, W; Jusko, A; Kaidalov, A B; Kalcher, S; Kalink, P; Kalisky, M; Kalliokoski, T; Kalweit, A; Kamal, A; Kamermans, R; Kanaki, K; Kang, E; Kang, J H; Kapitan, J; Kaplin, V; Kapusta, S; Karavichev, O; Karavicheva, T; Karpechev, E; Kazantsev, A; Kebschull, U; Keidel, R; Khan, M M; Khan, S A; Khanzadeev, A; Kharlov, Y; Kikola, D; Kileng, B; Kim, D J; Kim, D S; Kim, D W; Kim, H N; Kim, J; Kim, J H; Kim, J S; Kim, M; Kim, M; Kim, S H; Kim, S; Kim, Y; Kirsch, S; Kisel, I; Kiselev, S; Kisiel, A; Klay, J L; Klein, J; Klein-Bsing, C; Kliemant, M; Klovning, A; Kluge, A; Knichel, M L; Kniege, S; Koch, K; Kolevatov, R; Kolojvari, A; Kondratiev, V; Kondratyeva, N; Konevskih, A; Kornas, E; Kour, R; Kowalski, M; Kox, S; Kozlov, K; Kral, J; Krlik, I; Kramer, F; Kraus, I; Kravckov, A; Krawutschke, T; Krivda, M; Krumbhorn, D; Krus, M; Kryshen, E; Krzewicki, M; Kucheriaev, Y; Kuhn, C; Kuijer, P G; Kumar, L; Kumar, N; Kupczak, R; Kurashvili, P; Kurepin, A; Kurepin, A N; Kuryakin, A; Kushpil, S; Kushpil, V; Kutouski, M; Kvaerno, H; Kweon, M J; Kwon, Y; La Rocca, P; Lackner, F; Ladron de Guevara, P; Lafage, V; Lal, C; Lara, Camilo; Larsen, D T; Laurenti, G; Lazzeroni, C; Le Bornec, Y; Le Bris, N; Lee, H; Lee, K S; Lee, S C; Lefvre, F; Lenhardt, M; Leistam, L; Lehnert, J; Lenti, V; Leon, H; Leon Monzon, I; Leon Vargas, H; Lvai, P; Li, X; Li, Y; Lietava, R; Lindal, S; Lindenstruth, V; Lippmann, C; Lisa, M A; Liu, L; Loginov, V; Lohn, S; Lopez, X; Lopez Noriega, M; Lopez-Ramrez, R; Lopez Torres, E; Lvhiden, G; Lozea Feijo Soares, A; Lu, S; Luettig, P; Lunardon, M; Luparello, G; Luquin, L; Lutz, J R; Ma, K; Ma, R; Madagodahettige-Don, D M; Maevskaya, A; Mager, M; Mahapatra, D P; Maire, A; Makhlyueva, I; Mal'Kevich, D; Malaev, M; Malagalage, K J; Maldonado Cervantes, I; Malek, M; Malkiewicz, T; Malzacher, P; Mamonov, A; Manceau, L; Mangotra, L; Manko, V; Manso, F; Manzari, V; Mao, Y; Mares, J; Margagliotti, G V; Margotti, A; Marn, A; Martashvili, I; Martinengo, P; Martnez Hernndez, M I; Martnez Davalos, A; Martnez Garca, G; Maruyama, Y; Marzari Chiesa, A; Masciocchi, S; Masera, M; Masetti, M; Masoni, A; Massacrier, L; Mastromarco, M; Mastroserio, A; Matthews, Z L; Matyja, A; Mayani, D; Mazza, G; Mazzoni, M A; Meddi, F; Menchaca-Rocha, A; Mendez Lorenzo, P; Meoni, M; Mercado Prez, J; Mereu, P; Miake, Y; Michalon, A; Miftakhov, N; Milano, L; Milosevic, J; Minafra, F; Mischke, A; Miskowiec, D; Mitu, C; Mizoguchi, K; Mlynarz, J; Mohanty, B; Molnar, L; Mondal, M M; Montao Zetina, L; Monteno, M; Montes, E; Morando, M; Moretto, S; Morsch, A; Moukhanova, T; Muccifora, V; Mudnic, E; Muhuri, S; Mller, H; Munhoz, M G; Munoz, J; Musa, L; Musso, A; Nandi, B K; Nania, R; Nappi, E; Navach, F; Navin, S; Nayak, T K; Nazarenko, S; Nazarov, G; Nedosekin, A; Nendaz, F; Newby, J; Nianine, A; Nicassio, M; Nielsen, B S; Nikolaev, S; Nikolic, V; Nikulin, S; Nikulin, V; Nilsen, B S; Nilsson, M S; Noferini, F; Nomokonov, P; Nooren, G; Novitzky, N; Nyatha, A; Nygaard, C; Nyiri, A; Nystrand, J; Ochirov, A; Odyniec, G; Oeschler, H; Oinonen, M; Okada, K; Okada, Y; Oldenburg, M; Oleniacz, J; Oppedisano, C; Orsini, F; Ortiz Velasquez, A; Ortona, G; Oskarsson, A; Osmic, F; sterman, L; Ostrowski, P; Otterlund, I; Otwinowski, J; Øvrebekk, G; Oyama, K; Ozawa, K; Pachmayer, Y; Pachr, M; Padilla, F; Pagano, P; Paic, G; Painke, F; Pajares, C; Pal, S; Pal, S K; Palaha, A; Palmeri, A; Panse, R; Papikyan, V; Pappalardo, G S; Park, W J; Pastirck, B; Pastore, C; Paticchio, V; Pavlinov, A; Pawlak, T; Peitzmann, T; Pepato, A; Pereira, H; Peressounko, D; Prez, C; Perini, D; Perrino, D; Peryt, W; Peschek, J; Pesci, A; Peskov, V; Pestov, Y; Peters, A J; Petrcek, V; Petridis, A; Petris, M; Petrov, P; Petrovici, M; Petta, C; Peyr, J; Piano, S; Piccotti, A; Pikna, M; Pillot, P; Pinazza, O; Pinsky, L; Pitz, N; Piuz, F; Platt, R; Ploskon, M; Pluta, J; Pocheptsov, T; Pochybova, S; Podesta Lerma, P L M; Poggio, F; Poghosyan, M.G.; Polk, K; Polichtchouk, B; Polozov, P; Polyakov, V; Pommeresch, B; Pop, A; Posa, F; Pospsil, V; Potukuchi, B; Pouthas, J; Prasad, S K; Preghenella, R; Prino, F; Pruneau, C A; Pshenichnov, I; Puddu, G; Pujahari, P; Pulvirenti, A; Punin, A; Punin, V; Putis, M; Putschke, J; Quercigh, E; Rachevski, A; Rademakers, A; Radomski, S; Rih, T S; Rak, J; Rakotozafindrabe, A; Ramello, L; Ramrez Reyes, A; Rammler, M; Raniwala, R; Raniwala, S; Rsnen, S S; Rashevskaya, I; Rath, S; Read, K F; Real, J S; Redlich, K; Renfordt, R; Reolon, A R; Reshetin, A; Rettig, F; Revol, J P; Reygers, K; Ricaud, H; Riccati, L; Ricci, R A; Richter, M; Riedler, P; Riegler, W; Riggi, F; Rivetti, A; Rodriguez Cahuantzi, M; Red, K; Rhrich, D; Romn Lopez, S; Romita, R; Ronchetti, F; Rosinsk, P; Rosnet, P; Rossegger, S; Rossi, A; Roukoutakis, F; Rousseau, S; Roy, C; Roy, P; Rubio-Montero, A J; Rui, R; Rusanov, I; Russo, G; Ryabinkin, E; Rybicki, A; Sadovsky, S; Safark, K; Sahoo, R; Saini, J; Saiz, P; Sakata, D; Salgado, C A; Salgueiro Domingues da Silva, R; Salur, S; Samanta, T; Sambyal, S; Samsonov, V; Sndor, L; Sandoval, A; Sano, M; Sano, S; Santo, R; Santoro, R; Sarkamo, J; Saturnini, P; Scapparone, E; Scarlassara, F; Scharenberg, R P; Schiaua, C; Schicker, R; Schindler, H; Schmidt, C; Schmidt, H R; Schossmaier, K; Schreiner, S; Schuchmann, S; Schukraft, J; Schutz, Y; Schwarz, K; Schweda, K; Scioli, G; Scomparin, E; Scott, P A; Segato, G; Semenov, D; Senyukov, S; Seo, J; Serci, S; Serkin, L; Serradilla, E; Sevcenco, A; Sgura, I; Shabratova, G; Shahoyan, R; Sharkov, G; Sharma, N; Sharma, S; Shigaki, K; Shimomura, M; Shtejer, K; Sibiriak, Y; Siciliano, M; Sicking, E; Siddi, E; Siemiarczuk, T; Silenzi, A; Silvermyr, D; Simili, E; Simonetti, G; Singaraju, R; Singh, R; Singhal, V; Sinha, B C; Sinha, T; Sitar, B; Sitta, M; Skaali, T B; Skjerdal, K; Smakal, R; Smirnov, N; Snellings, R; Snow, H; Sgaard, C; Soloviev, A; Soltveit, H K; Soltz, R; Sommer, W; Son, C W; Son, H; Song, M; Soos, C; Soramel, F; Soyk, D; Spyropoulou-Stassinaki, M; Srivastava, B K; Stachel, J; Staley, F; Stan, E; Stefanek, G; Stefanini, G; Steinbeck, T; Stenlund, E; Steyn, G; Stocco, D; Stock, R; Stolpovsky, P; Strmen, P; Suaide, A A P; Subieta Vsquez, M A; Sugitate, T; Suire, C; Sumbera, M; Susa, T; Swoboda, D; Symons, J; Szanto de Toledo, A; Szarka, I; Szostak, A; Szuba, M; Tadel, M; Tagridis, C; Takahara, A; Takahashi, J; Tanabe, R; Tapia Takaki, J D; Taureg, H; Tauro, A; Tavlet, M; Tejeda Muoz, G; Telesca, A; Terrevoli, C; Thader, J; Tieulent, R; Tlusty, D; Toia, A; Tolyhy, T; Torcato de Matos, C; Torii, H; Torralba, G; Toscano, L; Tosello, F; Tournaire, A; Traczyk, T; Tribedy, P; Trger, G; Truesdale, D; Trzaska, W H; Tsiledakis, G; Tsilis, E; Tsuji, T; Tumkin, A; Turrisi, R; Turvey, A; Tveter, T S; Tydesj, H; Tywoniuk, K; Ulery, J; Ullaland, K; Uras, A; Urbn, J; Urciuoli, G M; Usai, G L; Vacchi, A; Vala, M; Valencia Palomo, L; Vallero, S; van der Kolk, N; Vande Vyvre, P; van Leeuwen, M; Vannucci, L; Vargas, A; Varma, R; Vasiliev, A; Vassiliev, I; Vasileiou, M; Vechernin, V; Venaruzzo, M; Vercellin, E; Vergara, S; Vernet, R; Verweij, M; Vetlitskiy, I; Vickovic, L; Viesti, G; Vikhlyantsev, O; Vilakazi, Z; Villalobos Baillie, O; Vinogradov, A; Vinogradov, L; Vinogradov, Y; Virgili, T; Viyogi, Y P; Vodopianov, A; Voloshin, K; Voloshin, S; Volpe, G; von Haller, B; Vranic, D; Vrlkov, J; Vulpescu, B; Wagner, B; Wagner, V; Wallet, L; Wan, R; Wang, D; Wang, Y; Wang, Y; Watanabe, K; Wen, Q; Wessels, J; Westerhoff, U; Wiechula, J; Wikne, J; Wilk, A; Wilk, G; Williams, M C S; Willis, N; Windelband, B; Xu, C; Yang, C; Yang, H; Yasnopolskiy, S; Yermia, F; Yi, J; Yin, Z; Yokoyama, H; Yoo, I K; Yuan, X; Yurevich, V; Yushmanov, I; Zabrodin, E; Zagreev, B; Zalite, A; Zampolli, C; Zanevsky, Yu; Zaporozhets, S; Zarochentsev, A; Zvada, P; Zbroszczyk, H; Zelnicek, P; Zenin, A; Zepeda, A; Zgura, I; Zhalov, M; Zhang, X; Zhou, D; Zhou, S; Zhu, J; Zichichi, A; Zinchenko, A; Zinovjev, G; Zoccarato, Y; Zychcek, V; Zynovyev, M

    2010-01-01

    The inclusive charged particle transverse momentum distribution is measured in proton-proton collisions at $\\sqrt{s} = 900$~GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region $(|\\eta|_{\\rm INEL}=0.483\\pm0.001$~(stat.)~$\\pm0.007$~(syst.)~GeV/$c$ and $\\left_{\\rm NSD}=0.489\\pm0.001$~(stat.)~$\\pm0.007$~(syst.)~GeV/$c$, respectively. The data exhibit a slightly larger $\\left$ than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET.

  5. Measurement of charged particle spectra in minimum-bias events from proton-proton collisions at $\\sqrt{s} = $ 13 TeV

    CERN Document Server

    CMS Collaboration

    2018-01-01

    Pseudorapidity, transverse momentum, and multiplicity distributions are measured in the pseudorapidity range $|{\\eta}| $ 0.5 GeV in proton-proton collisions at a center-of-mass energy of $\\sqrt{s} = $ 13 TeV. Measurements are presented in three different event categories. The most inclusive of the categories corresponds to an inelastic pp data set, while the other two categories are exclusive subsets of the inelastic sample that are either enhanced or depleted in single diffractive dissociation events. The measurements are compared to predictions from Monte Carlo event generators used to describe high-energy hadronic interactions in collider and cosmic-ray physics.

  6. Identification of heparin samples that contain impurities or contaminants by chemometric pattern recognition analysis of proton NMR spectral data

    Energy Technology Data Exchange (ETDEWEB)

    Zang, Qingda [University of Medicine and Dentistry of New Jersey, Department of Pharmacology, Robert Wood Johnson Medical School, Piscataway, NJ (United States); Snowdon, Inc., Monmouth Junction, NJ (United States); University of Medicine and Dentistry of New Jersey, Department of Health Informatics, School of Health Related Professions, Newark, NJ (United States); Keire, David A.; Buhse, Lucinda F.; Trehy, Michael L. [Food and Drug Administration, CDER, Division of Pharmaceutical Analysis, St. Louis, MO (United States); Wood, Richard D. [Snowdon, Inc., Monmouth Junction, NJ (United States); Mital, Dinesh P.; Haque, Syed; Srinivasan, Shankar [University of Medicine and Dentistry of New Jersey, Department of Health Informatics, School of Health Related Professions, Newark, NJ (United States); Moore, Christine M.V.; Nasr, Moheb; Al-Hakim, Ali [Food and Drug Administration, CDER, Office of New Drug Quality Assessment, Silver Spring, MD (United States); Welsh, William J. [University of Medicine and Dentistry of New Jersey, Department of Pharmacology, Robert Wood Johnson Medical School, Piscataway, NJ (United States)

    2011-08-15

    Chemometric analysis of a set of one-dimensional (1D) {sup 1}H nuclear magnetic resonance (NMR) spectral data for heparin sodium active pharmaceutical ingredient (API) samples was employed to distinguish USP-grade heparin samples from those containing oversulfated chondroitin sulfate (OSCS) contaminant and/or unacceptable levels of dermatan sulfate (DS) impurity. Three chemometric pattern recognition approaches were implemented: classification and regression tree (CART), artificial neural network (ANN), and support vector machine (SVM). Heparin sodium samples from various manufacturers were analyzed in 2008 and 2009 by 1D {sup 1}H NMR, strong anion-exchange high-performance liquid chromatography, and percent galactosamine in total hexosamine tests. Based on these data, the samples were divided into three groups: Heparin, DS {<=} 1.0% and OSCS = 0%; DS, DS > 1.0% and OSCS = 0%; and OSCS, OSCS > 0% with any content of DS. Three data sets corresponding to different chemical shift regions (1.95-2.20, 3.10-5.70, and 1.95-5.70 ppm) were evaluated. While all three chemometric approaches were able to effectively model the data in the 1.95-2.20 ppm region, SVM was found to substantially outperform CART and ANN for data in the 3.10-5.70 ppm region in terms of classification success rate. A 100% prediction rate was frequently achieved for discrimination between heparin and OSCS samples. The majority of classification errors between heparin and DS involved cases where the DS content was close to the 1.0% DS borderline between the two classes. When these borderline samples were removed, nearly perfect classification results were attained. Satisfactory results were achieved when the resulting models were challenged by test samples containing blends of heparin APIs spiked with non-, partially, or fully oversulfated chondroitin sulfate A, heparan sulfate, or DS at the 1.0%, 5.0%, and 10.0% (w/w) levels. This study demonstrated that the combination of 1D {sup 1}H NMR spectroscopy

  7. The investigation of hydrogens bonds between sulphur-bearing heterocyclic and proton-donor compounds by IR absorption spectra

    International Nuclear Information System (INIS)

    Narziev, B.N.; Nurulloev, M.; Makhkambaev, D.

    1982-01-01

    In this article the results of intermolecular interaction study of sulfur-containing heterocyclic (thiophene, thiophane) and proton-donar (water, alcohol, carbonic acids, chlorophon) molecules for measuring of IR spectrum absorption of protondonar compounds in soluted shape are presented

  8. Measurement of neutron spectra generated from bombardment of 4 to 24 MeV protons on a thick 9Be target and estimation of neutron yields

    International Nuclear Information System (INIS)

    Paul, Sabyasachi; Sahoo, G. S.; Tripathy, S. P.; Sunil, C.; Bandyopadhyay, T.; Sharma, S. C.; Ramjilal,; Ninawe, N. G.; Gupta, A. K.

    2014-01-01

    A systematic study on the measurement of neutron spectra emitted from the interaction of protons of various energies with a thick beryllium target has been carried out. The measurements were carried out in the forward direction (at 0° with respect to the direction of protons) using CR-39 detectors. The doses were estimated using the in-house image analyzing program autoTRAK-n, which works on the principle of luminosity variation in and around the track boundaries. A total of six different proton energies starting from 4 MeV to 24 MeV with an energy gap of 4 MeV were chosen for the study of the neutron yields and the estimation of doses. Nearly, 92% of the recoil tracks developed after chemical etching were circular in nature, but the size distributions of the recoil tracks were not found to be linearly dependent on the projectile energy. The neutron yield and dose values were found to be increasing linearly with increasing projectile energies. The response of CR-39 detector was also investigated at different beam currents at two different proton energies. A linear increase of neutron yield with beam current was observed

  9. Effect of solvent on proton location and dynamic behavior in short intramolecular hydrogen bonds studied by molecular dynamics simulations and NMR experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Yukie, E-mail: mori.yukie@ocha.ac.jp; Masuda, Yuichi

    2015-09-08

    Highlights: • MD simulations were performed to study dynamics of strong hydrogen bonds. • Nuclear magnetic relaxation times of proton were measured in solution. • The hydrogen bond of dibenzoylmethane enol is asymmetric in methanol solution. • Formation or breakage of intermolecular hydrogen bonds can trigger proton transfer. • Dimethylsulfoxide may form a bifurcated hydrogen bond with a hydrogen-bonded system. - Abstract: Hydrogen phthalate anion has a short strong O–H–O hydrogen bond (H-bond). According to previous experimental studies, the H-bond is asymmetric and two tautomers are interconverted in aqueous solutions. In the present study, the effects of polar solvents on the H-bond in a zwitterionic hydrogen phthalate derivative 1 were investigated by quantum mechanics/molecular mechanics molecular dynamics (MD) simulations. The analyses of the trajectories for the methanol solution showed that the H-bonding proton tends to be located closer to the carboxylate group that forms fewer intermolecular H-bonds, than to the other carboxylate group and that the intramolecular proton transfer in 1 is triggered by the breakage and/or formation of an intermolecular H-bond. The enol form of dibenzoylmethane (2) also has a short H-bond, and the OH bond is reported to be rather long (>1.1 Å) in the crystal. In the present study, the effects of the solvent on the H-bond in 2 were investigated by molecular orbital (MO) calculations, MD simulations and nuclear magnetic resonance (NMR) spectroscopy. Density functional theory (DFT) calculations for 2 in vacuum indicated that the barrier height for the intramolecular proton transfer is almost the same as the zero-point energy of the vibrational ground state, resulting in broad distribution of the proton density along the H-bond, owing to the nuclear quantum effect. The OH distances were determined in CCl{sub 4}, acetonitrile, and dimethylsulfoxide solutions from the magnetic dipolar interactions between the {sup 17

  10. Effect of solvent on proton location and dynamic behavior in short intramolecular hydrogen bonds studied by molecular dynamics simulations and NMR experiments

    International Nuclear Information System (INIS)

    Mori, Yukie; Masuda, Yuichi

    2015-01-01

    Highlights: • MD simulations were performed to study dynamics of strong hydrogen bonds. • Nuclear magnetic relaxation times of proton were measured in solution. • The hydrogen bond of dibenzoylmethane enol is asymmetric in methanol solution. • Formation or breakage of intermolecular hydrogen bonds can trigger proton transfer. • Dimethylsulfoxide may form a bifurcated hydrogen bond with a hydrogen-bonded system. - Abstract: Hydrogen phthalate anion has a short strong O–H–O hydrogen bond (H-bond). According to previous experimental studies, the H-bond is asymmetric and two tautomers are interconverted in aqueous solutions. In the present study, the effects of polar solvents on the H-bond in a zwitterionic hydrogen phthalate derivative 1 were investigated by quantum mechanics/molecular mechanics molecular dynamics (MD) simulations. The analyses of the trajectories for the methanol solution showed that the H-bonding proton tends to be located closer to the carboxylate group that forms fewer intermolecular H-bonds, than to the other carboxylate group and that the intramolecular proton transfer in 1 is triggered by the breakage and/or formation of an intermolecular H-bond. The enol form of dibenzoylmethane (2) also has a short H-bond, and the OH bond is reported to be rather long (>1.1 Å) in the crystal. In the present study, the effects of the solvent on the H-bond in 2 were investigated by molecular orbital (MO) calculations, MD simulations and nuclear magnetic resonance (NMR) spectroscopy. Density functional theory (DFT) calculations for 2 in vacuum indicated that the barrier height for the intramolecular proton transfer is almost the same as the zero-point energy of the vibrational ground state, resulting in broad distribution of the proton density along the H-bond, owing to the nuclear quantum effect. The OH distances were determined in CCl 4 , acetonitrile, and dimethylsulfoxide solutions from the magnetic dipolar interactions between the 17 O and 1

  11. Progress in proton-detected solid-state NMR (SSNMR): Super-fast 2D SSNMR collection for nano-mole-scale proteins

    Science.gov (United States)

    Ishii, Yoshitaka; Wickramasinghe, Ayesha; Matsuda, Isamu; Endo, Yuki; Ishii, Yuji; Nishiyama, Yusuke; Nemoto, Takahiro; Kamihara, Takayuki

    2018-01-01

    Proton-detected solid-state NMR (SSNMR) spectroscopy has attracted much attention due to its excellent sensitivity and effectiveness in the analysis of trace amounts of amyloid proteins and other important biological systems. In this perspective article, we present the recent sensitivity limit of 1H-detected SSNMR using "ultra-fast" magic-angle spinning (MAS) at a spinning rate (νR) of 80-100 kHz. It was demonstrated that the high sensitivity of 1H-detected SSNMR at νR of 100 kHz and fast recycling using the paramagnetic-assisted condensed data collection (PACC) approach permitted "super-fast" collection of 1H-detected 2D protein SSNMR. A 1H-detected 2D 1H-15N correlation SSNMR spectrum for ∼27 nmol of a uniformly 13C- and 15N-labeled GB1 protein sample in microcrystalline form was acquired in only 9 s with 50% non-uniform sampling and short recycle delays of 100 ms. Additional data suggests that it is now feasible to detect as little as 1 nmol of the protein in 5.9 h by 1H-detected 2D 1H-15N SSNMR at a nominal signal-to-noise ratio of five. The demonstrated sensitivity is comparable to that of modern solution protein NMR. Moreover, this article summarizes the influence of ultra-fast MAS and 1H-detection on the spectral resolution and sensitivity of protein SSNMR. Recent progress in signal assignment and structural elucidation by 1H-detected protein SSNMR is outlined with both theoretical and experimental aspects.

  12. Structural study of pyrones by NMR

    International Nuclear Information System (INIS)

    Mandarino, D.G.

    1985-01-01

    Extracts of two species of Aniba, designed Aniba-SA (light petroleum extract) and Aniba-SB (benzene extract), afforded by chromatographic fraccionation some compounds. The isolated compounds were identified using spectrometric data and C 13 -NMR coupled and decompled spectra of pyrones were registered. Measurement of the heteronuclear residual coupling by irradiation proton frequency off-resonance was used for distinguish C-5, C-7 and C-8 carbons of the pyrones SB-1, SB-3, SB-4 and SB-5. (M.J.C.) [pt

  13. Energy spectra of protons emitted in the p+Xe→p+... interactions at 2.34 GeV/c and π-+Xe→p+... at 9 GeV/c

    International Nuclear Information System (INIS)

    Slovinskij, B.; Mulas, Eh.

    1981-01-01

    The energy spectra of protons (ESP) emitted in reactions p+Xe→kp+... at 2.34 GeV/c (k=1-9) and π - +Xe→kp+... at 9 GeV/c (k=1-17) have been studied. An evidence has been obtained for a unified description of those spectra by an exponential dependence of the invariant cross sections upon the kinetic energy independently of the proton emission angle. It is found that the ESP temperature becomes independent of the proton emission frequency when the energy of the interaction induced hadron is greater than approximately 3 GeV [ru

  14. Calculation of proton and neutron emission spectra from proton reactions with 90Zr and 208Pb to 160 MeV with the GNASH code

    International Nuclear Information System (INIS)

    Young, P.G.; Chadwick, M.B.

    1994-01-01

    A number of modifications have been made to the reaction theory code GNASH in order the accuracy of calculations at incident particle energies up to 200 MeV. Direct reaction a level density models appropriate for higher energy calculations are now used in the code, and most importantly, improved preequilibrium models have been incorporated into the code system. The code has been used to calculate proton-induced reactions on 90 Zr and 208 Pb for the International Code and Model Intercomparison for Intermediate Energy Reactions organized by the NEA. Calculations were performed with GNASH at incident proton energies of 25, 45, 80, and 160 mev using both the exciton model and Feshbach-Kerman-Koonin theory for the preequilibrium component. The models and procedures used in the GNASH calculations with the exciton model are described here. The results are compared to experimental data and to results from the GNASH calculations with Feshbach-Kerman-Koonin preequilibrium theory

  15. Measurements of π{sup ±}, K{sup ±}, p and p spectra in proton-proton interactions at 20, 31, 40, 80 and 158 GeV/c with the NA61/SHINE spectrometer at the CERN SPS

    Energy Technology Data Exchange (ETDEWEB)

    Aduszkiewicz, A.; Dominik, W.; Kuich, M.; Matulewicz, T.; Podlaski, P.; Posiadala, M.; Walewski, M. [University of Warsaw, Warsaw (Poland); Ali, Y.; Brzychczyk, J.; Larsen, D.; Planeta, R.; Richter-Was, E.; Staszel, P.; Wyszynski, O. [Jagiellonian University, Krakow (Poland); Andronov, E.; Feofilov, G.A.; Igolkin, S.; Kondratiev, V.P.; Kovalenko, V.; Merzlaya, A.; Seryakov, A.; Vechernin, V.V.; Vinogradov, L. [St. Petersburg State University, St. Petersburg (Russian Federation); Anticic, T.; Kadija, K.; Susa, T. [Ruder Boskovic Institute, Zagreb (Croatia); Baatar, B.; Bunyatov, S.A.; Kireyeu, V.A.; Kolesnikov, V.I.; Krasnoperov, A.; Lyubushkin, V.V.; Malakhov, A.I.; Matveev, V.; Melkumov, G.L.; Tereshchenko, V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Baszczyk, M.; Dorosz, P.; Kucewicz, W.; Mik, L. [University of Science and Technology, Krakow (Poland); Bhosale, S.; Davis, N.; Kielbowicz, M.; Marcinek, A.; Ozvenchuk, V.; Rybicki, A. [H. Niewodniczanski Institute of Nuclear Physics of the Polish Academy of Sciences, Krakow (Poland); Blondel, A.; Bravar, A.; Damyanova, A.; Haesler, A.; Korzenev, A.; Ravonel, M. [University of Geneva, Geneva (Switzerland); Bogomilov, M.; Kolev, D.; Tsenov, R. [University of Sofia, Faculty of Physics, Sofia (Bulgaria); Brandin, A.; Selyuzhenkov, I.; Strikhanov, M.; Taranenko, A. [National Research Nuclear University (Moscow Engineering Physics Institute), Moscow (Russian Federation); Busygina, O.; Golubeva, M.; Guber, F.; Ivashkin, A.; Kurepin, A.; Sadovsky, A. [Institute for Nuclear Research, Moscow (Russian Federation); Cherif, H.; Deveaux, M.; Klochkov, V.; Koziel, M.; Renfordt, R.; Snoch, A.; Stroebele, H.; Toia, A. [University of Frankfurt, Frankfurt (Germany); Cirkovic, M.; Knezevic, N.; Manic, D.; Puzovic, J. [University of Belgrade, Belgrade (Serbia); Czopowicz, T.; Grebieszkow, K.; Mackowiak-Pawlowska, M.; Maksiak, B.; Slodkowski, M.; Tefelska, A.; Tefelski, D. [Warsaw University of Technology, Warsaw (Poland); Dembinski, H.; Engel, R.; Herve, A.E.; Mathes, H.J.; Roth, M.; Szuba, M.; Ulrich, R.; Unger, M.; Veberic, D. [Karlsruhe Institute of Technology, Karlsruhe (Germany); Dumarchez, J. [University of Paris VI and VII, LPNHE, Paris (France); Ereditato, A.; Francois, C.; Pistillo, C.; Wilkinson, C. [University of Bern, Bern (Switzerland); Fodor, Z. [Wigner Research Centre for Physics of the Hungarian Academy of Sciences, Budapest (Hungary); University of Wroclaw, Wroclaw (Poland); Garibov, A. [National Nuclear Research Center, Baku (Azerbaijan); Gazdzicki, M. [University of Frankfurt, Frankfurt (Germany); Jan Kochanowski University in Kielce, Kielce (Poland); Hylen, J.; Lundberg, B.; Marchionni, A.; Rameika, R.; Zwaska, R. [Fermilab, Batavia (United States); Johnson, S.R.; Marino, A.D.; Nagai, Y.; Rumberger, B.T.; Zimmerman, E.D. [University of Colorado, Boulder (United States); Kaptur, E.; Kowalski, S.; Lysakowski, B.; Pulawski, S.; Schmidt, K. [University of Silesia, Katowice (Poland); Kowalik, K.; Rondio, E.; Stepaniak, J. [National Centre for Nuclear Research, Warsaw (Poland); Laszlo, A.; Marton, K.; Vesztergombi, G. [Wigner Research Centre for Physics of the Hungarian Academy of Sciences, Budapest (Hungary); Lewicki, M.; Naskret, M.; Turko, L. [University of Wroclaw, Wroclaw (Poland); Messerly, B.; Paolone, V.; Wickremasinghe, A. [University of Pittsburgh, Pittsburgh (United States); Mills, G.B. [Los Alamos National Laboratory, Los Alamos (United States); Morozov, S.; Petukhov, O. [Institute for Nuclear Research, Moscow (Russian Federation); National Research Nuclear University (Moscow Engineering Physics Institute), Moscow (Russian Federation); Mrowczynski, S.; Rybczynski, M.; Seyboth, P.; Stefanek, G.; Wlodarczyk, Z.; Wojtaszek-Szwarc, A. [Jan Kochanowski University in Kielce, Kielce (Poland); Pavin, M. [Ruder Boskovic Institute, Zagreb (Croatia); University of Paris VI and VII, LPNHE, Paris (France); Popov, B.A. [University of Paris VI and VII, LPNHE, Paris (France); Joint Institute for Nuclear Research, Dubna (Russian Federation); Rauch, W. [Fachhochschule Frankfurt, Frankfurt (Germany); Roehrich, D. [University of Bergen, Bergen (Norway); Rustamov, A. [National Nuclear Research Center, Baku (Azerbaijan); University of Frankfurt, Frankfurt (Germany); Zambelli, L. [National Nuclear Research Center, Baku (Azerbaijan); University of Paris VI and VII, LPNHE, Paris (France); Collaboration: The NA61/SHINE Collaboration

    2017-10-15

    Measurements of inclusive spectra and mean multiplicities of π{sup ±}, K{sup ±}, p and p produced in inelastic p + p interactions at incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c (√(s) = 6.3, 7.7, 8.8, 12.3 and 17.3 GeV, respectively) were performed at the CERN Super Proton Synchrotron using the large acceptance NA61/SHINE hadron spectrometer. Spectra are presented as function of rapidity and transverse momentum and are compared to predictions of current models. The measurements serve as the baseline in the NA61/SHINE study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter. (orig.)

  16. Measurements of π±, K±, p and p spectra in proton-proton interactions at 20, 31, 40, 80 and 158 GeV/c with the NA61/SHINE spectrometer at the CERN SPS

    International Nuclear Information System (INIS)

    Aduszkiewicz, A.; Dominik, W.; Kuich, M.; Matulewicz, T.; Podlaski, P.; Posiadala, M.; Walewski, M.; Ali, Y.; Brzychczyk, J.; Larsen, D.; Planeta, R.; Richter-Was, E.; Staszel, P.; Wyszynski, O.; Andronov, E.; Feofilov, G.A.; Igolkin, S.; Kondratiev, V.P.; Kovalenko, V.; Merzlaya, A.; Seryakov, A.; Vechernin, V.V.; Vinogradov, L.; Anticic, T.; Kadija, K.; Susa, T.; Baatar, B.; Bunyatov, S.A.; Kireyeu, V.A.; Kolesnikov, V.I.; Krasnoperov, A.; Lyubushkin, V.V.; Malakhov, A.I.; Matveev, V.; Melkumov, G.L.; Tereshchenko, V.; Baszczyk, M.; Dorosz, P.; Kucewicz, W.; Mik, L.; Bhosale, S.; Davis, N.; Kielbowicz, M.; Marcinek, A.; Ozvenchuk, V.; Rybicki, A.; Blondel, A.; Bravar, A.; Damyanova, A.; Haesler, A.; Korzenev, A.; Ravonel, M.; Bogomilov, M.; Kolev, D.; Tsenov, R.; Brandin, A.; Selyuzhenkov, I.; Strikhanov, M.; Taranenko, A.; Busygina, O.; Golubeva, M.; Guber, F.; Ivashkin, A.; Kurepin, A.; Sadovsky, A.; Cherif, H.; Deveaux, M.; Klochkov, V.; Koziel, M.; Renfordt, R.; Snoch, A.; Stroebele, H.; Toia, A.; Cirkovic, M.; Knezevic, N.; Manic, D.; Puzovic, J.; Czopowicz, T.; Grebieszkow, K.; Mackowiak-Pawlowska, M.; Maksiak, B.; Slodkowski, M.; Tefelska, A.; Tefelski, D.; Dembinski, H.; Engel, R.; Herve, A.E.; Mathes, H.J.; Roth, M.; Szuba, M.; Ulrich, R.; Unger, M.; Veberic, D.; Dumarchez, J.; Ereditato, A.; Francois, C.; Pistillo, C.; Wilkinson, C.; Fodor, Z.; Garibov, A.; Gazdzicki, M.; Hylen, J.; Lundberg, B.; Marchionni, A.; Rameika, R.; Zwaska, R.; Johnson, S.R.; Marino, A.D.; Nagai, Y.; Rumberger, B.T.; Zimmerman, E.D.; Kaptur, E.; Kowalski, S.; Lysakowski, B.; Pulawski, S.; Schmidt, K.; Kowalik, K.; Rondio, E.; Stepaniak, J.; Laszlo, A.; Marton, K.; Vesztergombi, G.; Lewicki, M.; Naskret, M.; Turko, L.; Messerly, B.; Paolone, V.; Wickremasinghe, A.; Mills, G.B.; Morozov, S.; Petukhov, O.; Mrowczynski, S.; Rybczynski, M.; Seyboth, P.; Stefanek, G.; Wlodarczyk, Z.; Wojtaszek-Szwarc, A.; Pavin, M.; Popov, B.A.; Rauch, W.; Roehrich, D.; Rustamov, A.; Zambelli, L.

    2017-01-01

    Measurements of inclusive spectra and mean multiplicities of π ± , K ± , p and p produced in inelastic p + p interactions at incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c (√(s) = 6.3, 7.7, 8.8, 12.3 and 17.3 GeV, respectively) were performed at the CERN Super Proton Synchrotron using the large acceptance NA61/SHINE hadron spectrometer. Spectra are presented as function of rapidity and transverse momentum and are compared to predictions of current models. The measurements serve as the baseline in the NA61/SHINE study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter. (orig.)

  17. π± meson and proton spectra in central and peripheral collisions of p, 12C, 22Ne with photoemulsion nuclei at 4.5A GeV/c

    International Nuclear Information System (INIS)

    Vokal, S.; Tolstov, K.D.; Shabratova, G.S.; Leskin, V.A.

    1989-01-01

    Spectra of relativistic π ± mesons and protons undergoing interaction in inelastic collisions of p, 12 C, 22 Ne with photoemulsion nuclei are considered. The ratios of particle yields in g-fragment ensemble of 22 Ne nuclei at rest have been found. Experimental results are compared with the predictions of the cascade-evaporation model for 22 Ne+emulsion interactions. It is shown that the p tr spectra of π ± mesons and protons consist of two components. The average transverse momentum of the highly excited proton source in 22 Ne+emulsion interactions is equal to that in events of Ag total disintegration. The thermalization feature is fulfilled for protons from these events. The π ± meson yield per proton is 50% higher than it is in peripheral collisions

  18. A lower limit to the altitude of coronal particle storage regions deduced from solar proton energy spectra

    Science.gov (United States)

    Krimigis, S. M.

    1973-01-01

    The spectrum of low energy protons observed at 1 AU following solar flares shows little or no evidence of energy degradation down to approximately 0.3 MeV. Such observations may be used to set a lower limit on the altitude of hypothetical coronal particle storage regions, ranging from 2 to 7 R sub s. It is pointed out that closed coronal magnetic loop structures are observed to extend to 2R sub s, so that long-term storage of low energy protons does not take place in the immediate vicinity of the sun. It is further suggested that in the few cases where the proton spectrum appears to be degraded at low energies, the energy loss may be due to adiabatic deceleration in the expanding solar wind. The alternative of continual acceleration is suggested as a plausible substitute for the particle storage hypothesis.

  19. Assessment of 1H NMR-based metabolomics analysis for normalization of urinary metals against creatinine.

    Science.gov (United States)

    Cassiède, Marc; Nair, Sindhu; Dueck, Meghan; Mino, James; McKay, Ryan; Mercier, Pascal; Quémerais, Bernadette; Lacy, Paige

    2017-01-01

    Proton nuclear magnetic resonance ( 1 H NMR, or NMR) spectroscopy and inductively coupled plasma-mass spectrometry (ICP-MS) are commonly used for metabolomics and metal analysis in urine samples. However, creatinine quantification by NMR for the purpose of normalization of urinary metals has not been validated. We assessed the validity of using NMR analysis for creatinine quantification in human urine samples in order to allow normalization of urinary metal concentrations. NMR and ICP-MS techniques were used to measure metabolite and metal concentrations in urine samples from 10 healthy subjects. For metabolite analysis, two magnetic field strengths (600 and 700MHz) were utilized. In addition, creatinine concentrations were determined by using the Jaffe method. Creatinine levels were strongly correlated (R 2 =0.99) between NMR and Jaffe methods. The NMR spectra were deconvoluted with a target database containing 151 metabolites that are present in urine. A total of 50 metabolites showed good correlation (R 2 =0.7-1.0) at 600 and 700MHz. Metal concentrations determined after NMR-measured creatinine normalization were comparable to previous reports. NMR analysis provided robust urinary creatinine quantification, and was sufficient for normalization of urinary metal concentrations. We found that NMR-measured creatinine-normalized urinary metal concentrations in our control subjects were similar to general population levels in Canada and the United Kingdom. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Study of proton and carbon 13 nuclear magnetic resonance spectra of an allyl phenol derivatives series; Estudo de espectros de ressonancia magnetica nuclear protonica e de carbono 13 de uma serie de derivados de alilfenois

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Thais Horta Alvares da [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Faculdade de Farmacia. Dept. de Produtos Farmaceuticos; Oliveira, Alaide Braga de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica

    1991-12-31

    Quaternary ammonium salt derivates of natural ally phenols were synthesized with the purpose of obtaining peripheral analgesics. Eugenol, O-methyleugenol and safrole were submitted to nitration, reduction, per methylation. The amines were also transformed into their hydro chlorides. The {sup 1} HNMR spectra of the nitro compounds, amines, amine hydro chlorides, quaternary ammonium salts and dymethylamines were analysed, as well as the {sup 13} C NMR spectra of the nitro compounds and of the quaternary ammonium salts. (author). 8 refs., 4 tabs.

  1. Mixed micelles of polyethylene glycol (23) lauryl ether with ionic surfactants studied by proton 1D and 2D NMR.

    Science.gov (United States)

    Gao, Hong-Chang; Zhao, Sui; Mao, Shi-Zhen; Yuan, Han-Zhen; Yu, Jia-Yong; Shen, Lian-Fang; Du, You-Ru

    2002-05-01

    (1)H NMR chemical shift, spin-lattice relaxation time, spin-spin relaxation time, self-diffusion coefficient, and two-dimensional nuclear Overhauser enhancement (2D NOESY) measurements have been used to study the nonionic-ionic surfactant mixed micelles. Cetyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) were used as the ionic surfactants and polyethylene glycol (23) lauryl ether (Brij-35) as the nonionic surfactant. The two systems are both with varying molar ratios of CTAB/Brij-35 (C/B) and SDS/Brij-35 (S/B) ranging from 0.5 to 2, respectively, at a constant concentration of 6 mM for Brij-35 in aqueous solutions. Results give information about the relative arrangement of the surfactant molecules in the mixed micelles. In the former system, the trimethyl groups attached to the polar heads of the CTAB molecules are located between the first oxy-ethylene groups next to the hydrophobic chains of Brij-35 molecules. These oxy-ethylene groups gradually move outward from the hydrophobic core of the mixed micelle with an increase in C/B in the mixed solution. In contrast to the case of the CTAB/Triton X-100 system, the long flexible hydrophilic poly oxy-ethylene chains, which are in the exterior part of the mixed micelles, remain coiled, but looser, surrounding the hydrophobic core. There is almost no variation in conformation of the hydrophilic chains of Brij-35 molecules in the mixed micelles of the SDS/Brij-35 system as the S/B increases. The hydrophobic chains of both CTAB and SDS are co-aggregated with Brij-35, respectively, in their mixed micellar cores.

  2. Correlation of infrared spectra and phase transitions in annealed proton-exchanged MgO doped LiNbO3

    International Nuclear Information System (INIS)

    Sun, Jian; Xu, Chang-qing

    2015-01-01

    Infrared spectra of OH − groups in annealed proton-exchanged (APE) 5 mol. % MgO-doped LiNbO 3 (MgO:LiNbO 3 ) crystals were studied using the Fourier transform infrared spectroscopy technique. Samples were prepared by benzoic acid proton-exchange followed with thermal annealing in oxygen. Evolutions of absorption peaks in APE MgO:LiNbO 3 crystals were recorded and analyzed. Comparing with none-doped APE LiNbO 3 crystals, a different phase transition behavior was found during thermal annealing. A periodically poled MgO:LiNbO 3 slab waveguide was prepared using identical procedures, and the second harmonic generation (SHG) signals were measured. Comparing the obtained SHG results with the infrared spectra, relationships between the phase transitions and the recovery of second-order nonlinear coefficients during thermal annealing were investigated. Finally, a method for optimizing the performance of MgO:LiNbO 3 waveguides was proposed

  3. LET spectra behind high-density titanium and stainless steel hip implants irradiated with a therapeutic proton beam

    Czech Academy of Sciences Publication Activity Database

    Oancea, Cristina; Ambrožová, Iva; Popescu, A. I.; Mytsin, G. V.; Vondráček, V.; Davídková, Marie

    2018-01-01

    Roč. 110, č. 3 (2018), s. 7-13 ISSN 1350-4487 R&D Projects: GA MŠk EF16_013/0001677 Institutional support: RVO:61389005 Keywords : proton therapy * metallic hip implant * titanium * stainless steel * track etched detectors Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 1.442, year: 2016

  4. Recent trends on NMR imaging in UK and USA

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Masahiro [National Inst. of Radiological Sciences, Chiba (Japan)

    1981-12-01

    The development of nuclear magnetic resonance (NMR) by major research centers and manufacturers is reviewed. The spin warp method is used at Aberdeen University, and the T1 images of esophageal cancer and hepatic metastasis obtained by this method are shown. The Moore group at Nottingham University developed an instrument to scan the head region, and it produces spatial resolution comparable to x-ray computed tomography. The transverse image of the thorax obtained by the QED-80 developed by FONAR (U.S.A.) is shown. It uses field focusing NMR, and can measure spin density, T1, T2 and NMR spectrum, but its precision is slightly lowered because fewer proton spins are activated. These methods all measure the proton distribution in vivo, but with the TMR developed by Oxford Research Co. (U.K.) high resolution spectra of phosphorus 31 compounds can be obtained. The NMR spectra obtained for the phosphorus compounds in the muscle is shown. The rate of the phosphorus compounds such as ATP, ADP creatine phosphate and inorganic phosphate are markedly changed by exercise or depending on the blood flow.

  5. Quantitative NMR proton spectroscopy in vivo at 1,5 Tesla and possible applications to investigations of brain metabolism of depressive patients

    International Nuclear Information System (INIS)

    Metzler, D.

    1997-12-01

    Using a clinical magnetic resonance imaging/spectroscopy system 22 patients suffering from bipolar disorders and 22 healthy volunteers were examined by localized in vivo proton spectroscopy. The measurements were performed on a 1.5 Tesla whole body scanner of Siemens AG, Magnetom SP 4000, using the standard head coil (CP). For localization a STEAM sequence was used with an echo times TE of 55 ms. A recovery time of 3500 ms was chosen. The number of acquisitions was 256. The spectra were acquired from voxel volumes of 20 x 30 x 20 mm 3 . Three Gaussian presaturation pulses (CHESS) with subsequent dephasing gradients were used for water suppression. After correction for eddy-current effects and Fast-Fourier transformation the intensities of myo-inositol, choline compounds, creatine together with phospho-creatine, and N-acetylaspartate were evaluated from the spectra. The spectra from the frontal brain of depressed patients and controls revealed mInos/Cr ratios of about 0,4 - 0,5. This lies within the range, which is presumed to be the mInos concentration in 1 H-Magnetic Resonance Spectroscopy studies in human brain in vivo. Concerning the total sample (N = 2 x 22) there were no intergroup differences in the present study. Concluding a subsample of subjects younger than 40 years (N = 2 x 10), depressives showed lower mInos levels than controls in the right frontal lobe. The patients showed a significant positive correlation between age and mInos/Cr in the right frontal lobe, while in the left frontal lobe this could be seen only as a trend. In contrast, NAA/Cr decreased with increasing age. There were neither significant differences between sex nor between hemispheres. (author)

  6. NMR imaging and spectroscopy of the mammalian central nervous system after heavy ion radiation

    International Nuclear Information System (INIS)

    Richards, T.

    1984-09-01

    NMR imaging, NMR spectroscopic, and histopathologic techniques were used to study the proton relaxation time and related biochemical changes in the central nervous system after helium beam in vivo irradiation of the rodent brain. The spectroscopic observations reported in this dissertation were made possible by development of methods for measuring the NMR parameters of the rodent brain in vivo and in vitro. The methods include (1) depth selective spectroscopy using an optimization of rf pulse energy based on a priori knowledge of N-acetyl aspartate and lipid spectra of the normal brain, (2) phase-encoded proton spectroscopy of the living rodent using a surface coil, and (3) dual aqueous and organic tissue extraction technique for spectroscopy. Radiation induced increases were observed in lipid and p-choline peaks of the proton spectrum, in vivo. Proton NMR spectroscopy measurements on brain extracts (aqueous and organic solvents) were made to observe chemical changes that could not be seen in vivo. Radiation-induced changes were observed in lactate, GABA, glutamate, and p-choline peak areas of the aqueous fraction spectra. In the organic fraction, decreases were observed in peak area ratios of the terminal-methyl peaks, the N-methyl groups of choline, and at a peak at 2.84 ppM (phosphatidyl ethanolamine and phosphatidyl serine resonances) relative to TMS. With histology and Evans blue injections, blood-brain barrier alternations were seen as early as 4 days after irradiation. 83 references, 53 figures

  7. NMR imaging and spectroscopy of the mammalian central nervous system after heavy ion radiation

    Energy Technology Data Exchange (ETDEWEB)

    Richards, T.

    1984-09-01

    NMR imaging, NMR spectroscopic, and histopathologic techniques were used to study the proton relaxation time and related biochemical changes in the central nervous system after helium beam in vivo irradiation of the rodent brain. The spectroscopic observations reported in this dissertation were made possible by development of methods for measuring the NMR parameters of the rodent brain in vivo and in vitro. The methods include (1) depth selective spectroscopy using an optimization of rf pulse energy based on a priori knowledge of N-acetyl aspartate and lipid spectra of the normal brain, (2) phase-encoded proton spectroscopy of the living rodent using a surface coil, and (3) dual aqueous and organic tissue extraction technique for spectroscopy. Radiation induced increases were observed in lipid and p-choline peaks of the proton spectrum, in vivo. Proton NMR spectroscopy measurements on brain extracts (aqueous and organic solvents) were made to observe chemical changes that could not be seen in vivo. Radiation-induced changes were observed in lactate, GABA, glutamate, and p-choline peak areas of the aqueous fraction spectra. In the organic fraction, decreases were observed in peak area ratios of the terminal-methyl peaks, the N-methyl groups of choline, and at a peak at 2.84 ppM (phosphatidyl ethanolamine and phosphatidyl serine resonances) relative to TMS. With histology and Evans blue injections, blood-brain barrier alternations were seen as early as 4 days after irradiation. 83 references, 53 figures.

  8. Two-dimensional 1H and 31P NMR spectra of a decamer oligodeoxyribonucleotide duplex and a quinoxaline ([MeCys3, MeCys7]TANDEM) drug duplex complex

    International Nuclear Information System (INIS)

    Powers, R.; Olsen, R.K.; Gorenstein, D.G.

    1989-01-01

    Assignment of the 1H and 31P NMR spectra of a decamer oligodeoxyribonucleotide duplex, d(CCCGATCGGG), and its quinoxaline ([MeCys3, MeCys7]TANDEM) drug duplex complex has been made by two-dimensional 1H-1H and heteronuclear 31P-1H correlated spectroscopy. The 31P chemical shifts of this 10 base pair oligonucleotide follow the general observation that the more internal the phosphate is located within the oligonucleotide sequence, the more upfield the 31P resonance occurs. While the 31P chemical shifts show sequence-specific variations, they also do not generally follow the Calladine rules previously demonstrated. 31P NMR also provides a convenient monitor of the phosphate ester backbone conformational changes upon binding of the drug to the duplex. Although the quinoxaline drug, [MeCys3, MeCys7]TANDEM, is generally expected to bind to duplex DNA by bis-intercalation, only small 31P chemical shift changes are observed upon binding the drug to duplex d(CCCGATCGGG). Additionally, only small perturbations in the 1H NMR and UV spectra are observed upon binding the drug to the decamer, although association of the drug stabilizes the duplex form relative to the other states. These results are consistent with a non-intercalative mode of association of the drug. Modeling and molecular mechanics energy minimization demonstrate that a novel structure in which the two quinoxaline rings of the drug binds in the minor groove of the duplex is possible

  9. Theoretical predictions of the two-dimensional solid-state NMR spectra: a case study of the 13C-1H correlations in metergoline

    Czech Academy of Sciences Publication Activity Database

    Czernek, Jiří; Brus, Jiří

    2013-01-01

    Roč. 586, 24 October (2013), s. 56-60 ISSN 0009-2614 Institutional support: RVO:61389013 Keywords : NMR * shielding * metergoline Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.991, year: 2013

  10. N.M.R. study of organo-phosphorus compounds: non equivalence of methylenic protons in the {alpha} position of an asymmetric phosphorus atom. Application to study of coupling constants J{sub P,H} and J{sub H,H}; R.M.N. de composes organo-phosphores: non equivalence de protons methyleniques en {alpha} d'un phosphore asymetrique. Application a l'etude des constantes de couplage J{sub P,H} et J{sub H,H}

    Energy Technology Data Exchange (ETDEWEB)

    Albrand, J P [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    Non-equivalent methylenic protons, with respect to an asymmetric center, have been observed in the n.m.r. spectra of some three- and tetra-coordinated phosphorus compounds. The analysis of these spectra yield the following results: in the studied secondary phosphines, the inversion rate at the phosphorus atom is slow on the n.m.r. time scale; the geminal coupling constant, for a free-rotating methylene group attached to a phosphorus atom, is negative; in phosphines the non equivalence of methylenic protons reveals two {sup 2}J{sub P-C-H} coupling constants which differ by about 5 Hz. This result is in agreement with previous studies on cyclic phosphines. In phosphine oxides, the {sup 2}J{sub P-C-H} values are negative. The {sup 3}J{sub H-P-C-H} coupling constant is positive in both phosphines and phosphine oxides. In phosphines, the non-equivalent methylenic protons exhibit two nearly equal values for this coupling constant. (author) [French] La non-equivalence de protons methyleniques observee dans quelques composes phosphores tricoordines et tetracoordines a apporte les resultats suivants, concernant la stereochimie et les constantes de couplage dans ces composes: dans les phosphines secondaires, la structure pyramidale des liaisons issues du phosphore est fixe a l'echelle de temps de mesure de la R.M.N.; la constante de couplage {sup 2}J{sub H-C-H}, pour un methylene en libre rotation en {alpha} d'un atome de phosphore, est negative; dans les phosphines etudiees, la non-equivalence. observee pour les protons methyleniques s'accompagne d'une difference importante (5 Hz) entre les deux constantes de couplage {sup 2}J{sub P-C-H} determinees par l'analyse; ce resultat est en accord avec la stereospecificite deja observee pour ce couplage dans les phosphines cycliques. Les valeurs observees pour {sup 2}J{sub P-C-H} dans les oxydes de phosphines sont negatives. Les valeurs de la constante de couplage {sup 3}J{sub H-P-C-H}, dans les phosphines et oxydes de phosphine

  11. Spectra of the linear energy transfer measured with a track etch spectrometer in the beam of 1 GeV protons and the contribution of secondary charged particles to the dose

    International Nuclear Information System (INIS)

    Spurny, F.; Vlcek, B.; Bamblevskij, V.P.; Timoshenko, G.N.

    1999-01-01

    A spectrometer of the linear energy transfer (LET) on the base of CR-39 detector was used to establish the spectra of LET in the beam of protons with the primary energy of 1 GeV. It was found out that the LET spectra of secondary charged particles between 100 and 7000 MeV cm 2 g -1 do not depend on the radiator. The average quality factors for the LET region mentioned were obtained about 11.6 with ICRP 26 quality factors and about 14.0 with ICRP 60 quality factors. The spectra obtained permitted to calculate the contributions of these secondary charged particles to the dosimetric quantities. It was observed that these contributions were about 7.0% for the total absorbed dose of protons and close 90% in the case of the equivalent doses. It is more than it was found out for few hundred MeV protons

  12. On the reason for the kink in the rigidity spectra of cosmic-ray protons and helium nuclei near 230 GV

    Energy Technology Data Exchange (ETDEWEB)

    Loznikov, V. M., E-mail: loznikov@yandex.ru; Erokhin, N. S.; Zol’nikova, N. N.; Mikhailovskaya, L. A. [Russian Academy of Sciences, Space Research Institute (Russian Federation)

    2016-07-15

    A three-component phenomenological model describing the specific features of the spectrum of cosmic-ray protons and helium nuclei in the rigidity range of 30–2×10{sup 5} GV is proposed. The first component corresponds to the constant background; the second, to the variable “soft” (30–500 GV) heliospheric source; and the third, to the variable “hard” (0.5–200 TV) source located inside a local bubble. The existence and variability of both sources are provided by the corresponding “surfatron accelerators,” whose operation requires the presence of an extended region with an almost uniform (in both magnitude and direction) magnetic field, orthogonally (or obliquely) to which electromagnetic waves propagate. The maximum energy to which cosmic rays can be accelerated is determined by the source size. The soft source with a size of ∼100 AU is located at the periphery of the heliosphere, behind the front of the solar wind shock wave. The hard source with a size of >0.1 pc is located near the boundary of an interstellar cloud at a distance of ∼0.01 pc from the Sun. The presence of a kink in the rigidity spectra of p and He near 230 GV is related to the variability of the physical conditions in the acceleration region and depends on the relation between the amplitudes and power-law exponents in the dependences of the background, soft heliospheric source, and hard near galactic source. The ultrarelativistic acceleration of p and He by an electromagnetic wave propagating in space plasma across the external magnetic field is numerically analyzed. Conditions for particle trapping by the wave and the dynamics of the particle velocity and momentum components are considered. The calculations show that, in contrast to electrons and positrons (e{sup +}), the trapped protons relatively rapidly escape from the effective potential well and cease to accelerate. Due to this effect, the p and He spectra are softer than that of e{sup +}. The possibility that the

  13. High resolution deuterium NMR studies of bacterial metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Aguayo, J.B.; Gamcsik, M.P.; Dick, J.D.

    1988-12-25

    High resolution deuterium NMR spectra were obtained from suspensions of five bacterial strains: Escherichia coli, Clostridium perfringens, Klebsiella pneumoniae, Proteus mirabilis, and Staphylococcus aureus. Deuterium-labeled D-glucose at C-1, C-2, and C-6 was used to monitor dynamically anaerobic metabolism. The flux of glucose through the various bacterial metabolic pathways could be determined by following the disappearance of glucose and the appearance of the major end products in the 2H NMR spectrum. The presence of both labeled and unlabeled metabolites could be detected using 1H NMR spectroscopy since the proton resonances in the labeled species are shifted upfield due to an isotopic chemical shift effect. The 1H-1H scalar coupling observed in both the 2H and 1H NMR spectra was used to assign definitively the resonances of labeled species. An increase in the intensity of natural abundance deuterium signal of water can be used to monitor pathways in which a deuteron is lost from the labeled metabolite. The steps in which label loss can occur are outlined, and the influence these processes have on the ability of 2H NMR spectroscopy to monitor metabolism are assessed.

  14. High resolution deuterium NMR studies of bacterial metabolism

    International Nuclear Information System (INIS)

    Aguayo, J.B.; Gamcsik, M.P.; Dick, J.D.

    1988-01-01

    High resolution deuterium NMR spectra were obtained from suspensions of five bacterial strains: Escherichia coli, Clostridium perfringens, Klebsiella pneumoniae, Proteus mirabilis, and Staphylococcus aureus. Deuterium-labeled D-glucose at C-1, C-2, and C-6 was used to monitor dynamically anaerobic metabolism. The flux of glucose through the various bacterial metabolic pathways could be determined by following the disappearance of glucose and the appearance of the major end products in the 2H NMR spectrum. The presence of both labeled and unlabeled metabolites could be detected using 1H NMR spectroscopy since the proton resonances in the labeled species are shifted upfield due to an isotopic chemical shift effect. The 1H-1H scalar coupling observed in both the 2H and 1H NMR spectra was used to assign definitively the resonances of labeled species. An increase in the intensity of natural abundance deuterium signal of water can be used to monitor pathways in which a deuteron is lost from the labeled metabolite. The steps in which label loss can occur are outlined, and the influence these processes have on the ability of 2H NMR spectroscopy to monitor metabolism are assessed

  15. Human- and computer-accessible 2D correlation data for a more reliable structure determination of organic compounds. Future roles of researchers, software developers, spectrometer managers, journal editors, reviewers, publisher and database managers toward artificial-intelligence analysis of NMR spectra.

    Science.gov (United States)

    Jeannerat, Damien

    2017-01-01

    The introduction of a universal data format to report the correlation data of 2D NMR spectra such as COSY, HSQC and HMBC spectra will have a large impact on the reliability of structure determination of small organic molecules. These lists of assigned cross peaks will bridge signals found in NMR 1D and 2D spectra and the assigned chemical structure. The record could be very compact, human and computer readable so that it can be included in the supplementary material of publications and easily transferred into databases of scientific literature and chemical compounds. The records will allow authors, reviewers and future users to test the consistency and, in favorable situations, the uniqueness of the assignment of the correlation data to the associated chemical structures. Ideally, the data format of the correlation data should include direct links to the NMR spectra to make it possible to validate their reliability and allow direct comparison of spectra. In order to take the full benefits of their potential, the correlation data and the NMR spectra should therefore follow any manuscript in the review process and be stored in open-access database after publication. Keeping all NMR spectra, correlation data and assigned structures together at all time will allow the future development of validation tools increasing the reliability of past and future NMR data. This will facilitate the development of artificial intelligence analysis of NMR spectra by providing a source of data than can be used efficiently because they have been validated or can be validated by future users. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Single particle inclusive spectra resulting from the collision of relativistic protons, deuterons, alpha particles, and carbon ions with nuclei

    International Nuclear Information System (INIS)

    Papp, J.

    1975-05-01

    The yields of positive and negative particles resulting from the collision of 1.05 GeV/nucleon and 2.1 GeV/nucleon protons, deuterons, alpha particles, and 1.05 GeV/nucleon carbon nuclei with various targets have been measured. Single particle inclusive cross sections for production of π + , π - , p, d, 3 H, 3 He, and 4 He at 2.5 0 (lab) were obtained. How the results bear on the concepts of limiting fragmentation and scaling, the structure of the alpha particle and deuteron, and the possibility of ''coherent'' production of pions by heavy ions are discussed. (U.S.)

  17. Multivariate analysis of fingerprinting of majority secondary metabolites of propolis of Costa Rica using proton nuclear magnetic resonance (1H-NMR)

    International Nuclear Information System (INIS)

    Umana Rojas, Eduardo

    2013-01-01

    Propolis is produced by Apis mellifera bees from resins of plants that are found around the apiary. The chemical composition is highly variable and Costa Rica has reported without studies of characterization to define the types of propolis in the country. 119 samples were collected from beekeeping areas of the country. The spectrum of 1 H-NMR and its antioxidant activity against DPPH radical were measured. The spectra have been divided into 243 blocks of 0,04 ppm and processed with the Minitab software for multivariate analysis. 99 of the samples collected were used for construction of models for the valuation of the predictive ability of the model have been used coefficients of determination (R 2 ) of prediction by the software and the remaining 20 samples. The existence of three types of propolis with chemically different metabolomes were determined by principal component analysis (PCA). A prediction model was constructed by analysis of partial least squares (PLS). The prediction model has allowed to classify a propolis according to the level of anti-oxidant activity (AAO), high (type I and II) or low (type III) from the spectrum of 1 H-NMR. The R 2 has been 0.88 and R 2 prediction of 0, 718 for new samples. The n-coniferyl benzoate of group I and nemorosone of the group II as two discriminated antioxidants among the groups I and II were isolated and high concentration levels of these compounds have been differentiated with respect to type III. This has allowed the construction of a linear discriminant model with a success rate of 100% for the samples used for formulation and 92,9 for the prediction of different samples. The classification systems could be applied to the standardization of the quality of propolis from Costa Rica for future medicinal or cosmetic applications that take advantage of its antioxidant properties. Also, the methylated derivative has isolated and identified of the n-coniferyl benzoate thereof propolis than was obtained his counterpart

  18. PIC microcontroller based external fast analog to digital converter to acquire wide-lined solid NMR spectra by BRUKER DRX and Avance-I spectrometers.

    Science.gov (United States)

    Koczor, Bálint; Rohonczy, János

    2015-01-01

    Concerning many former liquid or hybrid liquid/solid NMR consoles, the built in Analog-to-Digital Converters (ADCs) are incapable of digitizing the fids at sampling rates in the MHz range. Regarding both strong anisotropic interactions in the solid state and wide chemical shift dispersion nuclei in solution phase such as (195)Pt, (119)Sn, (207)Pb etc., the spectrum range of interest might be in the MHz range. As determining the informative tensor components of anisotropic NMR interactions requires nonlinear fitting over the whole spectrum including the asymptotic baseline, it is prohibited by low sampling rates of the ADCs. Wide spectrum width is also useful in solution NMR, since windowing of wide chemical shift ranges is avoidable. We built an external analog to digital converter with 10 MHz maximal sampling rate, which can work simultaneously with the built in ADC of the spectrometer. The ADC was tested on both Bruker DRX and Avance-I NMR consoles. In addition to the analog channels it only requires three external digital lines of the NMR console. The ADC sends data to PC via USB. The whole process is controlled by software written in JAVA which is implemented under TopSpin. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Detailed {sup 1}H and {sup 13}C NMR spectral data assignment for two dihydrobenzofuran neolignans

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, Talita C.T.; Dias, Herbert J.; Crotti, Antônio E.M., E-mail: millercrotti@ffclrp.usp.br [Universidade de São Paulo (USP), Ribeirão Preto, SP (Brazil). Faculdade de Filosofia, Ciências e Letras. Departamento de Química

    2016-07-01

    In this work we present a complete proton ({sup 1}H) and carbon 13 ({sup 13}C) nuclear magnetic resonance (NMR) spectral analysis of two synthetic dihydrofuran neolignans (±)-trans-dehydrodicoumarate dimethyl ester and (±)-trans-dehydrodiferulate dimethyl ester. Unequivocal assignments were achieved by 1 H NMR, proton decoupled {sup 13}C ({sup 13}C{"1H}) NMR spectra, gradient-selected correlation spectroscopy (gCOSY), J-resolved, gradient-selected heteronuclear multiple quantum coherence (gHMQC), gradient-selected heteronuclear multiple bond coherence (gHMBC) and nuclear Overhauser effect spectroscopy (NOESY) experiments. All hydrogen coupling constants were measured, clarifying all the hydrogen signals multiplicities. Computational methods were also used to simulate the {sup 1}H and {sup 13}C chemical shifts and showed good agreement with the trans configuration of the substituents at C{sub 7} and C{sub 8}. (author)

  20. Detailed 1H and 13C NMR spectral data assignment for two dihydrobenzofuran neolignans

    International Nuclear Information System (INIS)

    Medeiros, Talita C.T.; Dias, Herbert J.; Crotti, Antônio E.M.

    2016-01-01

    In this work we present a complete proton ( 1 H) and carbon 13 ( 13 C) nuclear magnetic resonance (NMR) spectral analysis of two synthetic dihydrofuran neolignans (±)-trans-dehydrodicoumarate dimethyl ester and (±)-trans-dehydrodiferulate dimethyl ester. Unequivocal assignments were achieved by 1 H NMR, proton decoupled 13 C ( 13 C{ 1 H}) NMR spectra, gradient-selected correlation spectroscopy (gCOSY), J-resolved, gradient-selected heteronuclear multiple quantum coherence (gHMQC), gradient-selected heteronuclear multiple bond coherence (gHMBC) and nuclear Overhauser effect spectroscopy (NOESY) experiments. All hydrogen coupling constants were measured, clarifying all the hydrogen signals multiplicities. Computational methods were also used to simulate the 1 H and 13 C chemical shifts and showed good agreement with the trans configuration of the substituents at C 7 and C 8 . (author)

  1. Measurements of neutron spectra produced from a thick tungsten target bombarded with 5 and 15 GeV protons

    CERN Document Server

    Meigo, S; Shigyo, N; Iga, K; Iwamoto, Y; Kitsuki, H; Ishibashi, K; Maehata, K; Arima, H; Nakamo, T; Numajiri, M

    2002-01-01

    For validation of calculation codes that are employed in the design of a pulse spallation neutron source and accelerator driven system, the spectrum of neutrons produced from a thick target plays an important role. However, appropriate experimental data were scarce for incident energies higher than 0.8 GeV. In this study, the spectrum from a thick tungsten target was measured. The experiment was carried out at the pi 2 beam line of the 12-GeV proton synchrotron at KEK. The tungsten target was bombarded by 0.5- and 1.5-GeV secondary protons. The spectrum of neutrons was measured by the time-of-flight technique using organic scintillators of NE213. The calculated result with NMTC/JAM and MCNP-4A is compared with the measured data. It is found that the NMTC/JAM generally gives a good agreement with experiment. The NMTC/JAM, however, gives 50% lower neutron flux in the energy region 20~80 MeV, which is consistent with the results in a previous comparison of a lead target. For the neutrons between 20 and 80 MeV, t...

  2. NMR imaging studies of coal

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Z.R.; Zhang, P.Z.; Ding, G.L.; Li, L.Y.; Ye, C.H. [University of Science and Technology, Beijing (China). Dept. of Chemistry

    1996-06-01

    The permeation transportation and swelling behavior of solvents into coal are investigated by NMR imaging using pyridine-d{sub 5} and acetone-d{sub 6}. Images of coal swollen with deuterated solvents illuminate proton distributions of mobile phases within the coal macromolecular networks. More information about the chemical and physical structure of coal can be obtained using NMR imaging techniques.

  3. Theoretical and experimental NMR studies on muscimol from fly agaric mushroom (Amanita muscaria)

    Science.gov (United States)

    Kupka, Teobald; Wieczorek, Piotr P.

    2016-01-01

    In this article we report results of combined theoretical and experimental NMR studies on muscimol, the bioactive alkaloid from fly agaric mushroom (Amanita muscaria). The assignment of 1H and 13C NMR spectra of muscimol in DMSO-d6 was supported by additional two-dimensional heteronuclear correlated spectra (2D NMR) and gauge independent atomic orbital (GIAO) NMR calculations using density functional theory (DFT). The effect of solvent in theoretical calculations was included via polarized continuum model (PCM) and the hybrid three-parameter B3LYP density functional in combination with 6-311++G(3df,2pd) basis set enabled calculation of reliable structures of non-ionized (neutral) molecule and its NH and zwitterionic forms in the gas phase, chloroform, DMSO and water. GIAO NMR calculations, using equilibrium and rovibrationally averaged geometry, at B3LYP/6-31G* and B3LYP/aug-cc-pVTZ-J levels of theory provided muscimol nuclear magnetic shieldings. The theoretical proton and carbon chemical shifts were critically compared with experimental NMR spectra measured in DMSO. Our results provide useful information on its structure in solution. We believe that such data could improve the understanding of basic features of muscimol at atomistic level and provide another tool in studies related to GABA analogs.

  4. Magnetic moment of extremely proton-rich nucleus 23Al

    International Nuclear Information System (INIS)

    Nagatomo, T; Matsuta, K; Ozawa, A; Nakashima, Y; Matsumiya, R; Mihara, M; Yasuno, T; Chiba, A; Yamada, K; Momota; Ohtsubo, T; Ohta, M; Shinojima, D; Izumikawa, T; Tanaka, H; Yamaguchi, T; Nakajima, S; Maemura, H; Muranaka, K; Kumashiro, S; Fujiwara, H; Yoshida, K; Sumikama, T; Tanaka, K; Ogura, M; Minamisono, K; Fukuda, M; Minamisono, T; Nojiri, Y; Suzuki, T; Tanihata, I; Alonso, J R; Krebs, G F; Symons, T J M

    2005-01-01

    The g-factor of the extremely proton-rich nucleus 23 Al (T 1/2 = 0.47 s) has been measured by means of the β-NMR method for the first time. The g-factor were determined as |g| = 1.557(88) from the obtained NMR spectra. From the comparison between the experimental value and the shell model calculation, the spin parity of the ground state of 23 Al was determined as I π = 5/2 + . Thus, the magnetic moment of 23 Al was determined as vertical bar μvertical bar = 3.89(22)μ N

  5. Classification of spectra and search for bio-makers in prostate tumours form proton nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Parfait, S.

    2010-01-01

    Prostate cancer is the most common cancer in men over 50 years. Current detection methods either lack sensitivity or specificity or are unpleasant for the patient. Magnetic resonance spectroscopy allows the study of metabolism in vivo. The use of a high field machine (>3 T) has allowed us to dispense with the use of an endorectal coil, which is particularly uncomfortable for the patient. The objective of this work is to create an automatic method to detect cancer by processing data obtained through magnetic resonance spectroscopy. MRS is a complex phenomenon, very sensitive to acquisition conditions. First, we have studied how to improve and optimise signal acquisition. However, even with a very good quality signal, it must still undergo further post-processing to be analysed automatically by a classification method. Further work was therefore needed to investigate which post-processing steps were required in order to optimize the spectra for classification. We then investigated the optimal classification method for this problem. A particular set of steps (signal acquisition, processing and spectral classification data) allows us to highlight the presence of prostate tumors with an overall error rate of less than 12%. In a second step, we searched for new bio-markers within the spectra. These bio-markers could be a metabolite or a specific frequency range corresponding to several metabolites. We did not find any additional significant attributes other than choline and citrate, however, some frequency bands seem to participate in improving the error rate. Finally, we expanded our investigation by attempting to apply these techniques to the rat. Technical constraints related to acquisition did not allow us to obtain a sufficient number of spectra in the pre-clinical cases. Nonetheless, we have validated the feasibility of MRS in rodents and its relevance in the brain. The technique, however, must be improved in order to be validated in the case of prostate cancer in

  6. Search for narrow resonances in dilepton mass spectra in proton-proton collisions at $\\sqrt{s} = $ 13 TeV and combination with 8 TeV data

    CERN Document Server

    Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Aşılar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; König, Axel; Krätschmer, Ilse; Liko, Dietrich; Matsushita, Takashi; Mikulec, Ivan; Rabady, Dinyar; Rad, Navid; Rahbaran, Babak; Rohringer, Herbert; Schieck, Jochen; Strauss, Josef; Treberer-Treberspurg, Wolfgang; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; De Wolf, Eddi A; Janssen, Xavier; Lauwers, Jasper; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; Daci, Nadir; De Bruyn, Isabelle; Deroover, Kevin; Heracleous, Natalie; Lowette, Steven; Moortgat, Seth; Moreels, Lieselotte; Olbrechts, Annik; Python, Quentin; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Parijs, Isis; Brun, Hugues; Caillol, Cécile; Clerbaux, Barbara; De Lentdecker, Gilles; Delannoy, Hugo; Fasanella, Giuseppe; Favart, Laurent; Goldouzian, Reza; Grebenyuk, Anastasia; Karapostoli, Georgia; Lenzi, Thomas; Léonard, Alexandre; Luetic, Jelena; Maerschalk, Thierry; Marinov, Andrey; Randle-conde, Aidan; Seva, Tomislav; Vander Velde, Catherine; Vanlaer, Pascal; Yonamine, Ryo; Zenoni, Florian; Zhang, Fengwangdong; Cimmino, Anna; Cornelis, Tom; Dobur, Didar; Fagot, Alexis; Garcia, Guillaume; Gul, Muhammad; Poyraz, Deniz; Salva Diblen, Sinem; Schöfbeck, Robert; Sharma, Archana; Tytgat, Michael; Van Driessche, Ward; Yazgan, Efe; Zaganidis, Nicolas; Bakhshiansohi, Hamed; Beluffi, Camille; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Caudron, Adrien; De Visscher, Simon; Delaere, Christophe; Delcourt, Martin; Francois, Brieuc; Giammanco, Andrea; Jafari, Abideh; Jez, Pavel; Komm, Matthias; Lemaitre, Vincent; Magitteri, Alessio; Mertens, Alexandre; Musich, Marco; Nuttens, Claude; Piotrzkowski, Krzysztof; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Wertz, Sébastien; Beliy, Nikita; Aldá Júnior, Walter Luiz; Alves, Fábio Lúcio; Alves, Gilvan; Brito, Lucas; Hensel, Carsten; Moraes, Arthur; Pol, Maria Elena; Rebello Teles, Patricia; Belchior Batista Das Chagas, Ewerton; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Melo Da Costa, Eliza; Da Silveira, Gustavo Gil; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Huertas Guativa, Lina Milena; Malbouisson, Helena; Matos Figueiredo, Diego; Mora Herrera, Clemencia; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Ahuja, Sudha; Bernardes, Cesar Augusto; Dogra, Sunil; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Moon, Chang-Seong; Novaes, Sergio F; Padula, Sandra; Romero Abad, David; Ruiz Vargas, José Cupertino; Aleksandrov, Aleksandar; Hadjiiska, Roumyana; Iaydjiev, Plamen; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Fang, Wenxing; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Chen, Ye; Cheng, Tongguang; Jiang, Chun-Hua; Leggat, Duncan; Liu, Zhenan; Romeo, Francesco; Shaheen, Sarmad Masood; Spiezia, Aniello; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Zhang, Huaqiao; Zhao, Jingzhou; Ban, Yong; Chen, Geng; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; González Hernández, Carlos Felipe; Ruiz Alvarez, José David; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Sculac, Toni; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Ferencek, Dinko; Kadija, Kreso; Micanovic, Sasa; Sudic, Lucija; Susa, Tatjana; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Rykaczewski, Hans; Finger, Miroslav; Finger Jr, Michael; Carrera Jarrin, Edgar; Ellithi Kamel, Ali; Mahmoud, Mohammed; Radi, Amr; Calpas, Betty; Kadastik, Mario; Murumaa, Marion; Perrini, Lucia; Raidal, Martti; Tiko, Andres; Veelken, Christian; Eerola, Paula; Pekkanen, Juska; Voutilainen, Mikko; Härkönen, Jaakko; Karimäki, Veikko; Kinnunen, Ritva; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Talvitie, Joonas; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Ghosh, Saranya; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Kucher, Inna; Locci, Elizabeth; Machet, Martina; Malcles, Julie; Rander, John; Rosowsky, André; Titov, Maksym; Zghiche, Amina; Abdulsalam, Abdulla; Antropov, Iurii; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Cadamuro, Luca; Chapon, Emilien; Charlot, Claude; Davignon, Olivier; Granier de Cassagnac, Raphael; Jo, Mihee; Lisniak, Stanislav; Miné, Philippe; Nguyen, Matthew; Ochando, Christophe; Ortona, Giacomo; Paganini, Pascal; Pigard, Philipp; Regnard, Simon; Salerno, Roberto; Sirois, Yves; Strebler, Thomas; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Aubin, Alexandre; Bloch, Daniel; Brom, Jean-Marie; Buttignol, Michael; Chabert, Eric Christian; Chanon, Nicolas; Collard, Caroline; Conte, Eric; Coubez, Xavier; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Le Bihan, Anne-Catherine; Skovpen, Kirill; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Bernet, Colin; Boudoul, Gaelle; Bouvier, Elvire; Carrillo Montoya, Camilo Andres; Chierici, Roberto; Contardo, Didier; Courbon, Benoit; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Grenier, Gérald; Ille, Bernard; Lagarde, Francois; Laktineh, Imad Baptiste; Lethuillier, Morgan; Mirabito, Laurent; Pequegnot, Anne-Laure; Perries, Stephane; Popov, Andrey; Sabes, David; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Toriashvili, Tengizi; Rurua, Lali; Autermann, Christian; Beranek, Sarah; Feld, Lutz; Heister, Arno; Kiesel, Maximilian Knut; Klein, Katja; Lipinski, Martin; Ostapchuk, Andrey; Preuten, Marius; Raupach, Frank; Schael, Stefan; Schomakers, Christian; Schulte, Jan-Frederik; Schulz, Johannes; Verlage, Tobias; Weber, Hendrik; Zhukov, Valery; Brodski, Michael; Dietz-Laursonn, Erik; Duchardt, Deborah; Endres, Matthias; Erdmann, Martin; Erdweg, Sören; Esch, Thomas; Fischer, Robert; Güth, Andreas; Hamer, Matthias; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Knutzen, Simon; Merschmeyer, Markus; Meyer, Arnd; Millet, Philipp; Mukherjee, Swagata; Olschewski, Mark; Padeken, Klaas; Pook, Tobias; Radziej, Markus; Reithler, Hans; Rieger, Marcel; Scheuch, Florian; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Cherepanov, Vladimir; Flügge, Günter; Haj Ahmad, Wael; Hoehle, Felix; Kargoll, Bastian; Kress, Thomas; Künsken, Andreas; Lingemann, Joschka; Müller, Thomas; Nehrkorn, Alexander; Nowack, Andreas; Nugent, Ian Michael; Pistone, Claudia; Pooth, Oliver; Stahl, Achim; Aldaya Martin, Maria; Asawatangtrakuldee, Chayanit; Beernaert, Kelly; Behnke, Olaf; Behrens, Ulf; Bin Anuar, Afiq Aizuddin; Borras, Kerstin; Campbell, Alan; Connor, Patrick; Contreras-Campana, Christian; Costanza, Francesco; Diez Pardos, Carmen; Dolinska, Ganna; Eckerlin, Guenter; Eckstein, Doris; Eren, Engin; Gallo, Elisabetta; Garay Garcia, Jasone; Geiser, Achim; Gizhko, Andrii; Grados Luyando, Juan Manuel; Gunnellini, Paolo; Harb, Ali; Hauk, Johannes; Hempel, Maria; Jung, Hannes; Kalogeropoulos, Alexis; Karacheban, Olena; Kasemann, Matthias; Keaveney, James; Kleinwort, Claus; Korol, Ievgen; Krücker, Dirk; Lange, Wolfgang; Lelek, Aleksandra; Leonard, Jessica; Lipka, Katerina; Lobanov, Artur; Lohmann, Wolfgang; Mankel, Rainer; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mittag, Gregor; Mnich, Joachim; Mussgiller, Andreas; Ntomari, Eleni; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Roland, Benoit; Sahin, Mehmet Özgür; Saxena, Pooja; Schoerner-Sadenius, Thomas; Seitz, Claudia; Spannagel, Simon; Stefaniuk, Nazar; Van Onsem, Gerrit Patrick; Walsh, Roberval; Wissing, Christoph; Blobel, Volker; Centis Vignali, Matteo; Draeger, Arne-Rasmus; Dreyer, Torben; Garutti, Erika; Gonzalez, Daniel; Haller, Johannes; Hoffmann, Malte; Junkes, Alexandra; Klanner, Robert; Kogler, Roman; Kovalchuk, Nataliia; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Marconi, Daniele; Meyer, Mareike; Niedziela, Marek; Nowatschin, Dominik; Pantaleo, Felice; Peiffer, Thomas; Perieanu, Adrian; Poehlsen, Jennifer; Sander, Christian; Scharf, Christian; Schleper, Peter; Schmidt, Alexander; Schumann, Svenja; Schwandt, Joern; Stadie, Hartmut; Steinbrück, Georg; Stober, Fred-Markus Helmut; Stöver, Marc; Tholen, Heiner; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Vanhoefer, Annika; Vormwald, Benedikt; Barth, Christian; Baus, Colin; Berger, Joram; Butz, Erik; Chwalek, Thorsten; Colombo, Fabio; De Boer, Wim; Dierlamm, Alexander; Fink, Simon; Friese, Raphael; Giffels, Manuel; Gilbert, Andrew; Goldenzweig, Pablo; Haitz, Dominik; Hartmann, Frank; Heindl, Stefan Michael; Husemann, Ulrich; Katkov, Igor; Lobelle Pardo, Patricia; Maier, Benedikt; Mildner, Hannes; Mozer, Matthias Ulrich; Müller, Thomas; Plagge, Michael; Quast, Gunter; Rabbertz, Klaus; Röcker, Steffen; Roscher, Frank; Schröder, Matthias; Shvetsov, Ivan; Sieber, Georg; Simonis, Hans-Jürgen; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weber, Marc; Weiler, Thomas; Williamson, Shawn; Wöhrmann, Clemens; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Topsis-Giotis, Iasonas; Kesisoglou, Stilianos; Panagiotou, Apostolos; Saoulidou, Niki; Tziaferi, Eirini; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Kokkas, Panagiotis; Loukas, Nikitas; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Filipovic, Nicolas; Bencze, Gyorgy; Hajdu, Csaba; Hidas, Pàl; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Makovec, Alajos; Molnar, Jozsef; Szillasi, Zoltan; Bartók, Márton; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Bahinipati, Seema; Choudhury, Somnath; Mal, Prolay; Mandal, Koushik; Nayak, Aruna; Sahoo, Deepak Kumar; Sahoo, Niladribihari; Swain, Sanjay Kumar; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Chawla, Ridhi; Bhawandeep, Bhawandeep; Kalsi, Amandeep Kaur; Kaur, Anterpreet; Kaur, Manjit; Kumar, Ramandeep; Mehta, Ankita; Mittal, Monika; Singh, Jasbir; Walia, Genius; Kumar, Ashok; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Garg, Rocky Bala; Keshri, Sumit; Malhotra, Shivali; Naimuddin, Md; Nishu, Nishu; Ranjan, Kirti; Sharma, Ramkrishna; Sharma, Varun; Bhattacharya, Rajarshi; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dey, Sourav; Dutt, Suneel; Dutta, Suchandra; Ghosh, Shamik; Majumdar, Nayana; Modak, Atanu; Mondal, Kuntal; Mukhopadhyay, Supratik; Nandan, Saswati; Purohit, Arnab; Roy, Ashim; Roy, Debarati; Roy Chowdhury, Suvankar; Sarkar, Subir; Sharan, Manoj; Thakur, Shalini; Behera, Prafulla Kumar; Chudasama, Ruchi; Dutta, Dipanwita; Jha, Vishwajeet; Kumar, Vineet; Mohanty, Ajit Kumar; Netrakanti, Pawan Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Dugad, Shashikant; Kole, Gouranga; Mahakud, Bibhuprasad; Mitra, Soureek; Mohanty, Gagan Bihari; Parida, Bibhuti; Sur, Nairit; Sutar, Bajrang; Banerjee, Sudeshna; Bhowmik, Sandeep; Dewanjee, Ram Krishna; Ganguly, Sanmay; Guchait, Monoranjan; Jain, Sandhya; Kumar, Sanjeev; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Sarkar, Tanmay; Wickramage, Nadeesha; Chauhan, Shubhanshu; Dube, Sourabh; Hegde, Vinay; Kapoor, Anshul; Kothekar, Kunal; Rane, Aditee; Sharma, Seema; Behnamian, Hadi; Chenarani, Shirin; Eskandari Tadavani, Esmaeel; Etesami, Seyed Mohsen; Fahim, Ali; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Rezaei Hosseinabadi, Ferdos; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Calabria, Cesare; Caputo, Claudio; Colaleo, Anna; Creanza, Donato; Cristella, Leonardo; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; Miniello, Giorgia; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Ranieri, Antonio; Selvaggi, Giovanna; Silvestris, Lucia; Venditti, Rosamaria; Verwilligen, Piet; Abbiendi, Giovanni; Battilana, Carlo; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Chhibra, Simranjit Singh; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Albergo, Sebastiano; Chiorboli, Massimiliano; Costa, Salvatore; Di Mattia, Alessandro; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Gori, Valentina; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Viliani, Lorenzo; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Primavera, Federica; Calvelli, Valerio; Ferro, Fabrizio; Lo Vetere, Maurizio; Monge, Maria Roberta; Robutti, Enrico; Tosi, Silvano; Brianza, Luca; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Ghezzi, Alessio; Govoni, Pietro; Malberti, Martina; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Marzocchi, Badder; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Pigazzini, Simone; Ragazzi, Stefano; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; De Nardo, Guglielmo; Di Guida, Salvatore; Esposito, Marco; Fabozzi, Francesco; Iorio, Alberto Orso Maria; Lanza, Giuseppe; Lista, Luca; Meola, Sabino; Paolucci, Pierluigi; Sciacca, Crisostomo; Thyssen, Filip; Azzi, Patrizia; Bacchetta, Nicola; Benato, Lisa; Bisello, Dario; Boletti, Alessio; Carlin, Roberto; Carvalho Antunes De Oliveira, Alexandra; Checchia, Paolo; Dall'Osso, Martino; De Castro Manzano, Pablo; Dorigo, Tommaso; Dosselli, Umberto; Gasparini, Fabrizio; Gasparini, Ugo; Gozzelino, Andrea; Lacaprara, Stefano; Margoni, Martino; Meneguzzo, Anna Teresa; Pazzini, Jacopo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Zanetti, Marco; Zotto, Pierluigi; Zucchetta, Alberto; Zumerle, Gianni; Braghieri, Alessandro; Magnani, Alice; Montagna, Paolo; Ratti, Sergio P; Re, Valerio; Riccardi, Cristina; Salvini, Paola; Vai, Ilaria; Vitulo, Paolo; Alunni Solestizi, Luisa; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Leonardi, Roberto; Mantovani, Giancarlo; Menichelli, Mauro; Saha, Anirban; Santocchia, Attilio; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fedi, Giacomo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Cipriani, Marco; D'imperio, Giulia; Del Re, Daniele; Diemoz, Marcella; Gelli, Simone; Longo, Egidio; Margaroli, Fabrizio; Meridiani, Paolo; Organtini, Giovanni; Paramatti, Riccardo; Preiato, Federico; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bartosik, Nazar; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Costa, Marco; Cotto, Giorgio; Covarelli, Roberto; Degano, Alessandro; Demaria, Natale; Finco, Linda; Kiani, Bilal; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Monteil, Ennio; Obertino, Maria Margherita; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Ravera, Fabio; Romero, Alessandra; Rotondo, Francesco; Ruspa, Marta; Sacchi, Roberto; Sola, Valentina; Solano, Ada; Staiano, Amedeo; Traczyk, Piotr; Belforte, Stefano; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; La Licata, Chiara; Schizzi, Andrea; Zanetti, Anna; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Lee, Sangeun; Lee, Seh Wook; Oh, Young Do; Sekmen, Sezen; Son, Dong-Chul; Yang, Yu Chul; Lee, Ari; Kim, Hyunchul; Brochero Cifuentes, Javier Andres; Kim, Tae Jeong; Cho, Sungwoong; Choi, Suyong; Go, Yeonju; Gyun, Dooyeon; Ha, Seungkyu; Hong, Byung-Sik; Jo, Youngkwon; Kim, Yongsun; Lee, Byounghoon; Lee, Kisoo; Lee, Kyong Sei; Lee, Songkyo; Lim, Jaehoon; Park, Sung Keun; Roh, Youn; Almond, John; Kim, Junho; Lee, Haneol; Lee, Kyeongpil; Nam, Kyungwook; Oh, Sung Bin; Radburn-Smith, Benjamin Charles; Seo, Seon-hee; Yang, Unki; Yoo, Hwi Dong; Yu, Geum Bong; Choi, Minkyoo; Kim, Hyunyong; Kim, Ji Hyun; Lee, Jason Sang Hun; Park, Inkyu; Ryu, Geonmo; Ryu, Min Sang; Choi, Young-Il; Goh, Junghwan; Hwang, Chanwook; Lee, Jongseok; Yu, Intae; Dudenas, Vytautas; Juodagalvis, Andrius; Vaitkus, Juozas; Ahmed, Ijaz; Ibrahim, Zainol Abidin; Komaragiri, Jyothsna Rani; Md Ali, Mohd Adli Bin; Mohamad Idris, Faridah; Wan Abdullah, Wan Ahmad Tajuddin; Yusli, Mohd Nizam; Zolkapli, Zukhaimira; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-De La Cruz, Ivan; Hernandez-Almada, Alberto; Lopez-Fernandez, Ricardo; Magaña Villalba, Ricardo; Mejia Guisao, Jhovanny; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Oropeza Barrera, Cristina; Vazquez Valencia, Fabiola; Carpinteyro, Severiano; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Uribe Estrada, Cecilia; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Khan, Wajid Ali; Shah, Mehar Ali; Shoaib, Muhammad; Waqas, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Bunkowski, Karol; Byszuk, Adrian; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michal; Walczak, Marek; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Nemallapudi, Mythra Varun; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; Belotelov, Ivan; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Moisenz, Petr; Palichik, Vladimir; Perelygin, Victor; Savina, Maria; Shmatov, Sergey; Shulha, Siarhei; Smirnov, Vitaly; Voytishin, Nikolay; Zarubin, Anatoli; Chtchipounov, Leonid; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Kuznetsova, Ekaterina; Murzin, Victor; Oreshkin, Vadim; Sulimov, Valentin; Vorobyev, Alexey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Karneyeu, Anton; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Pozdnyakov, Ivan; Safronov, Grigory; Spiridonov, Alexander; Toms, Maria; Vlasov, Evgueni; Zhokin, Alexander; Bylinkin, Alexander; Chadeeva, Marina; Popova, Elena; Tarkovskii, Evgenii; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Rusakov, Sergey V; Terkulov, Adel; Baskakov, Alexey; Belyaev, Andrey; Boos, Edouard; Dubinin, Mikhail; Dudko, Lev; Ershov, Alexander; Gribushin, Andrey; Klyukhin, Vyacheslav; Kodolova, Olga; Lokhtin, Igor; Miagkov, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Snigirev, Alexander; Blinov, Vladimir; Skovpen, Yuri; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Elumakhov, Dmitry; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Cirkovic, Predrag; Devetak, Damir; Dordevic, Milos; Milosevic, Jovan; Rekovic, Vladimir; Alcaraz Maestre, Juan; Barrio Luna, Mar; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Navarro De Martino, Eduardo; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Senghi Soares, Mara; de Trocóniz, Jorge F; Missiroli, Marino; Moran, Dermot; Cuevas, Javier; Fernandez Menendez, Javier; Gonzalez Caballero, Isidro; González Fernández, Juan Rodrigo; Palencia Cortezon, Enrique; Sanchez Cruz, Sergio; Suárez Andrés, Ignacio; Vizan Garcia, Jesus Manuel; Cabrillo, Iban Jose; Calderon, Alicia; Castiñeiras De Saa, Juan Ramon; Curras, Esteban; Fernandez, Marcos; Garcia-Ferrero, Juan; Gomez, Gervasio; Lopez Virto, Amparo; Marco, Jesus; Martinez Rivero, Celso; Matorras, Francisco; Piedra Gomez, Jonatan; Rodrigo, Teresa; Ruiz-Jimeno, Alberto; Scodellaro, Luca; 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Jandir, Pawandeep; Kennedy, Elizabeth; Lacroix, Florent; Long, Owen Rosser; Olmedo Negrete, Manuel; Paneva, Mirena Ivova; Shrinivas, Amithabh; Si, Weinan; Wei, Hua; Wimpenny, Stephen; Yates, Brent; Branson, James G; Cerati, Giuseppe Benedetto; Cittolin, Sergio; Derdzinski, Mark; Gerosa, Raffaele; Holzner, André; Klein, Daniel; Krutelyov, Vyacheslav; Letts, James; Macneill, Ian; Olivito, Dominick; Padhi, Sanjay; Pieri, Marco; Sani, Matteo; Sharma, Vivek; Simon, Sean; Tadel, Matevz; Vartak, Adish; Wasserbaech, Steven; Welke, Charles; Wood, John; Würthwein, Frank; Yagil, Avraham; Zevi Della Porta, Giovanni; Bhandari, Rohan; Bradmiller-Feld, John; Campagnari, Claudio; Dishaw, Adam; Dutta, Valentina; Flowers, Kristen; Franco Sevilla, Manuel; Geffert, Paul; George, Christopher; Golf, Frank; Gouskos, Loukas; Gran, Jason; Heller, Ryan; Incandela, Joe; Mccoll, Nickolas; Mullin, Sam Daniel; Ovcharova, Ana; Richman, Jeffrey; Stuart, David; Suarez, Indara; Yoo, Jaehyeok; Anderson, Dustin; Apresyan, Artur; 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Butler, Joel Nathan; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Cremonesi, Matteo; Elvira, Victor Daniel; Fisk, Ian; Freeman, Jim; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Hare, Daryl; Harris, Robert M; Hasegawa, Satoshi; Hirschauer, James; Hu, Zhen; Jayatilaka, Bodhitha; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Klima, Boaz; Kreis, Benjamin; Lammel, Stephan; Linacre, Jacob; Lincoln, Don; Lipton, Ron; Liu, Tiehui; Lopes De Sá, Rafael; Lykken, Joseph; Maeshima, Kaori; Magini, Nicolo; Marraffino, John Michael; Maruyama, Sho; Mason, David; McBride, Patricia; Merkel, Petra; Mrenna, Stephen; Nahn, Steve; Newman-Holmes, Catherine; O'Dell, Vivian; Pedro, Kevin; Prokofyev, Oleg; Rakness, Gregory; Ristori, Luciano; Sexton-Kennedy, Elizabeth; Soha, Aron; Spalding, William J; Spiegel, Leonard; Stoynev, Stoyan; Strobbe, Nadja; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; Vaandering, Eric Wayne; Vernieri, Caterina; Verzocchi, Marco; Vidal, Richard; Wang, Michael; Weber, Hannsjoerg Artur; Whitbeck, Andrew; Acosta, Darin; Avery, Paul; Bortignon, Pierluigi; Bourilkov, Dimitri; Brinkerhoff, Andrew; Carnes, Andrew; Carver, Matthew; Curry, David; Das, Souvik; Field, Richard D; Furic, Ivan-Kresimir; Konigsberg, Jacobo; Korytov, Andrey; Ma, Peisen; Matchev, Konstantin; Mei, Hualin; Milenovic, Predrag; Mitselmakher, Guenakh; Rank, Douglas; Shchutska, Lesya; Sperka, David; Thomas, Laurent; Wang, Jian; Wang, Sean-Jiun; Yelton, John; Linn, Stephan; Markowitz, Pete; Martinez, German; Rodriguez, Jorge Luis; Ackert, Andrew; Adams, Jordon Rowe; Adams, Todd; Askew, Andrew; Bein, Samuel; Diamond, Brendan; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Khatiwada, Ajeeta; Prosper, Harrison; Santra, Arka; Weinberg, Marc; Baarmand, Marc M; Bhopatkar, Vallary; Colafranceschi, Stefano; Hohlmann, Marcus; Noonan, Daniel; Roy, Titas; Yumiceva, Francisco; Adams, Mark Raymond; Apanasevich, Leonard; Berry, Douglas; Betts, Russell Richard; Bucinskaite, Inga; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Kurt, Pelin; O'Brien, Christine; Sandoval Gonzalez, Irving Daniel; Turner, Paul; Varelas, Nikos; Wang, Hui; Wu, Zhenbin; Zakaria, Mohammed; Zhang, Jingyu; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Durgut, Süleyman; Gandrajula, Reddy Pratap; Haytmyradov, Maksat; Khristenko, Viktor; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Snyder, Christina; Tiras, Emrah; Wetzel, James; Yi, Kai; Anderson, Ian; Blumenfeld, Barry; Cocoros, Alice; Eminizer, Nicholas; Fehling, David; Feng, Lei; Gritsan, Andrei; Maksimovic, Petar; Osherson, Marc; Roskes, Jeffrey; Sarica, Ulascan; Swartz, Morris; Xiao, Meng; Xin, Yongjie; You, Can; Al-bataineh, Ayman; Baringer, Philip; Bean, Alice; Boren, Samuel; Bowen, James; Bruner, Christopher; Castle, James; Forthomme, Laurent; Kenny III, Raymond Patrick; Kropivnitskaya, Anna; Majumder, Devdatta; Mcbrayer, William; Murray, Michael; Sanders, Stephen; Stringer, Robert; Tapia Takaki, Daniel; Wang, Quan; Ivanov, Andrew; Kaadze, Ketino; Khalil, Sadia; Makouski, Mikhail; Maravin, Yurii; Mohammadi, Abdollah; Saini, Lovedeep Kaur; Skhirtladze, Nikoloz; Toda, Sachiko; Rebassoo, Finn; Wright, Douglas; Anelli, Christopher; Baden, Drew; Baron, Owen; Belloni, Alberto; Calvert, Brian; Eno, Sarah Catherine; Ferraioli, Charles; Gomez, Jaime; Hadley, Nicholas John; Jabeen, Shabnam; Kellogg, Richard G; Kolberg, Ted; Kunkle, Joshua; Lu, Ying; Mignerey, Alice; Shin, Young Ho; Skuja, Andris; Tonjes, Marguerite; Tonwar, Suresh C; Abercrombie, Daniel; Allen, Brandon; Apyan, Aram; Barbieri, Richard; Baty, Austin; Bi, Ran; Bierwagen, Katharina; Brandt, Stephanie; Busza, Wit; Cali, Ivan Amos; Demiragli, Zeynep; Di Matteo, Leonardo; Gomez Ceballos, Guillelmo; Goncharov, Maxim; Hsu, Dylan; Iiyama, Yutaro; Innocenti, Gian Michele; Klute, Markus; Kovalskyi, Dmytro; Krajczar, Krisztian; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Marini, Andrea Carlo; Mcginn, Christopher; Mironov, Camelia; Narayanan, Siddharth; Niu, Xinmei; Paus, Christoph; Roland, Christof; Roland, Gunther; Salfeld-Nebgen, Jakob; Stephans, George; Sumorok, Konstanty; Tatar, Kaya; Varma, Mukund; Velicanu, Dragos; Veverka, Jan; Wang, Jing; Wang, Ta-Wei; Wyslouch, Bolek; Yang, Mingming; Zhukova, Victoria; Benvenuti, Alberto; Chatterjee, Rajdeep Mohan; Evans, Andrew; Finkel, Alexey; Gude, Alexander; Hansen, Peter; Kalafut, Sean; Kao, Shih-Chuan; Kubota, Yuichi; Lesko, Zachary; Mans, Jeremy; Nourbakhsh, Shervin; Ruckstuhl, Nicole; Rusack, Roger; Tambe, Norbert; Turkewitz, Jared; Acosta, John Gabriel; Oliveros, Sandra; Avdeeva, Ekaterina; Bartek, Rachel; Bloom, Kenneth; Claes, Daniel R; Dominguez, Aaron; Fangmeier, Caleb; Gonzalez Suarez, Rebeca; Kamalieddin, Rami; Kravchenko, Ilya; Malta Rodrigues, Alan; Meier, Frank; Monroy, Jose; Siado, Joaquin Emilo; Snow, Gregory R; Stieger, Benjamin; Alyari, Maral; Dolen, James; George, Jimin; Godshalk, Andrew; Harrington, Charles; Iashvili, Ia; Kaisen, Josh; Kharchilava, Avto; Kumar, Ashish; Parker, Ashley; Rappoccio, Salvatore; Roozbahani, Bahareh; Alverson, George; Barberis, Emanuela; Baumgartel, Darin; Hortiangtham, Apichart; Massironi, Andrea; Morse, David Michael; Nash, David; Orimoto, Toyoko; Teixeira De Lima, Rafael; Trocino, Daniele; Wang, Ren-Jie; Wood, Darien; Bhattacharya, Saptaparna; Hahn, Kristan Allan; Kubik, Andrew; Kumar, Ajay; Low, Jia Fu; Mucia, Nicholas; Odell, Nathaniel; Pollack, Brian; Schmitt, Michael Henry; Sung, Kevin; Trovato, Marco; Velasco, Mayda; Dev, Nabarun; Hildreth, Michael; Hurtado Anampa, Kenyi; Jessop, Colin; Karmgard, Daniel John; Kellams, Nathan; Lannon, Kevin; Marinelli, Nancy; Meng, Fanbo; Mueller, Charles; Musienko, Yuri; Planer, Michael; Reinsvold, Allison; Ruchti, Randy; Smith, Geoffrey; Taroni, Silvia; Wayne, Mitchell; Wolf, Matthias; Woodard, Anna; Alimena, Juliette; Antonelli, Louis; Brinson, Jessica; Bylsma, Ben; Durkin, Lloyd Stanley; Flowers, Sean; Francis, Brian; Hart, Andrew; Hill, Christopher; Hughes, Richard; Ji, Weifeng; Liu, Bingxuan; Luo, Wuming; Puigh, Darren; Winer, Brian L; Wulsin, Howard Wells; Cooperstein, Stephane; Driga, Olga; Elmer, Peter; Hardenbrook, Joshua; Hebda, Philip; Lange, David; Luo, Jingyu; Marlow, Daniel; Medvedeva, Tatiana; Mei, Kelvin; Mooney, Michael; Olsen, James; Palmer, Christopher; Piroué, Pierre; Stickland, David; Tully, Christopher; Zuranski, Andrzej; Malik, Sudhir; Barker, Anthony; Barnes, Virgil E; Folgueras, Santiago; Gutay, Laszlo; Jha, Manoj; Jones, Matthew; Jung, Andreas Werner; Jung, Kurt; Miller, David Harry; Neumeister, Norbert; Shi, Xin; Sun, Jian; Svyatkovskiy, Alexey; Wang, Fuqiang; Xie, Wei; Xu, Lingshan; Parashar, Neeti; Stupak, John; Adair, Antony; Akgun, Bora; Chen, Zhenyu; Ecklund, Karl Matthew; Geurts, Frank JM; Guilbaud, Maxime; Li, Wei; Michlin, Benjamin; Northup, Michael; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Rorie, Jamal; Tu, Zhoudunming; Zabel, James; Betchart, Burton; Bodek, Arie; de Barbaro, Pawel; Demina, Regina; Duh, Yi-ting; Ferbel, Thomas; Galanti, Mario; Garcia-Bellido, Aran; Han, Jiyeon; Hindrichs, Otto; Khukhunaishvili, Aleko; Lo, Kin Ho; Tan, Ping; Verzetti, Mauro; Agapitos, Antonis; Chou, John Paul; Contreras-Campana, Emmanuel; Gershtein, Yuri; Gómez Espinosa, Tirso Alejandro; Halkiadakis, Eva; Heindl, Maximilian; Hidas, Dean; Hughes, Elliot; Kaplan, Steven; Kunnawalkam Elayavalli, Raghav; Kyriacou, Savvas; Lath, Amitabh; Nash, Kevin; Saka, Halil; Salur, Sevil; Schnetzer, Steve; Sheffield, David; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Foerster, Mark; Heideman, Joseph; Riley, Grant; Rose, Keith; Spanier, Stefan; Thapa, Krishna; Bouhali, Othmane; Celik, Ali; Dalchenko, Mykhailo; De Mattia, Marco; Delgado, Andrea; Dildick, Sven; Eusebi, Ricardo; Gilmore, Jason; Huang, Tao; Juska, Evaldas; Kamon, Teruki; Mueller, Ryan; Pakhotin, Yuriy; Patel, Rishi; Perloff, Alexx; Perniè, Luca; Rathjens, Denis; Rose, Anthony; Safonov, Alexei; Tatarinov, Aysen; Ulmer, Keith; Akchurin, Nural; Cowden, Christopher; Damgov, Jordan; De Guio, Federico; Dragoiu, Cosmin; Dudero, Phillip Russell; Faulkner, James; Kunori, Shuichi; Lamichhane, Kamal; Lee, Sung Won; Libeiro, Terence; Peltola, Timo; Undleeb, Sonaina; Volobouev, Igor; Wang, Zhixing; Delannoy, Andrés G; Greene, Senta; Gurrola, Alfredo; Janjam, Ravi; Johns, Willard; Maguire, Charles; Melo, Andrew; Ni, Hong; Sheldon, Paul; Tuo, Shengquan; Velkovska, Julia; Xu, Qiao; Arenton, Michael Wayne; Barria, Patrizia; Cox, Bradley; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Neu, Christopher; Sinthuprasith, Tutanon; Sun, Xin; Wang, Yanchu; Wolfe, Evan; Xia, Fan; Clarke, Christopher; Harr, Robert; Karchin, Paul Edmund; Lamichhane, Pramod; Sturdy, Jared; Belknap, Donald; Dasu, Sridhara; Dodd, Laura; Duric, Senka; Gomber, Bhawna; Grothe, Monika; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Lanaro, Armando; Levine, Aaron; Long, Kenneth; Loveless, Richard; Ojalvo, Isabel; Perry, Thomas; Polese, Giovanni; Ruggles, Tyler; Savin, Alexander; Smith, Nicholas; Smith, Wesley H; Taylor, Devin; Woods, Nathaniel

    2017-05-10

    A search for narrow resonances in dielectron and dimuon invariant mass spectra has been performed using data obtained from proton-proton collisions at $ \\sqrt{s} = $ 13 TeV collected with the CMS detector. The integrated luminosity for the dielectron sample is 2.7 fb$^{-1}$ and for the dimuon sample 2.9 fb$^{-1}$. The sensitivity of the search is increased by combining these data with a previously analysed set of data obtained at $ \\sqrt{s} = $ 8 TeV and corresponding to a luminosity of 20 fb$^{-1}$. No evidence for non-standard-model physics is found, either in the 13 TeV data set alone, or in the combined data set. Upper limits on the product of production cross section and branching fraction have also been calculated in a model-independent manner to enable interpretation in models predicting a narrow dielectron or dimuon resonance structure. Limits are set on the masses of hypothetical particles that could appear in new-physics scenarios. For the $\\mathrm{Z}'_{\\text{SSM}}$ particle, which arises in the seq...

  7. Measurements of Cross Sections and Charged Pion Spectra in Proton-Carbon Interactions at 31 GeV/c

    CERN Document Server

    Abgrall, N; Andrieu, B; Anticic, T; Antoniou, N; Argyriades, J; Asryan, A G; Baatar, B; Blondel, A; Blumer, J; Bogusz, M; Boldizsar, L; Bravar, A; Brooks, W; Brzychczyk, J; Bubak, A; Bunyatov, S A; Busygina, O; Cetner, T; Choi, K -U; Christakoglou, P; Chung, P; Czopowicz, T; Davis, N; Diakonos, F; Di Luise, S; Dominik, W; Dumarchez, J; Engel, R; Ereditato, A; Esposito, L S; Feofilov, G A; Fodor, Z; Ferrero, A; Fulop, A; Garrido, X; Gazdzicki, M; Golubeva, M; Grebieszkow, K; Grzeszczuk, A; Guber, F; Hakobyan, H; Hasegawa, T; Igolkin, S; Ivanov, A S; Ivanov, Y; Ivashkin, A; Kadija, K; Kapoyannis, A; Katrynska, N N; Kielczewska, D; Kikola, D; Kim, J -H; Kirejczyk, M; Kisiel, J; Kobayashi, T; Kochebina, O; Kolesnikov, V I; Kolev, D; Kondratiev, V P; Korzenev, A; Kowalski, S; Kuleshov, S; Kurepin, A; Lacey, R; Lagoda, J; Laszlo, A; Lyubushkin, V V; Mackowiak, M; Majka, Z; Malakhov, A I; Marchionni, A; Marcinek, A; Maris, I; Marin, V; Matulewicz, T; Matveev, V; Melkumov, G L; Meregaglia, A; Messina, M; Mrowczynski, St; Murphy, S; Nakadaira, T; Naumenko, P A; Nishikawa, K; Palczewski, T; Palla, G; Panagiotou, A D; Peryt, W; Petukhov, O; Planeta, R.; Pluta, J; Popov, B A; Posiadala, M; Pu lawski, S; Rauch, W; Ravonel, M; Renfordt, R; Robert, A; Rohrich, D; Rondio, E; Rossi, B; Roth, M; Rubbia, A; Rybczynski, M; Sadovsky, A; Sakashita, K; Sekiguchi, T; Seyboth, P; Shibata, M; Sissakian, A N; Skrzypczak, E; Slodkowski, M.; Sorin, A S; Staszel, P; Stefanek, G; Stepaniak, J; Strabel, C; Strobele, H; Susa, T; Szaik, P; Szuba, M; Tada, M; Taranenko, A; Tsenov, R; Ulrich, R; Unger, M; Vassiliou, M; Vechernin, V V; Vesztergombi, G; Wilczek, A; lodarczyk, Z W; Wojtaszek, A; Yi, J -G; Yoo, I -K; Zipper, W

    2011-01-01

    Interaction cross sections and charged pion spectra in p+C interactions at 31 GeV/c were measured with the large acceptance NA61/SHINE spectrometer at the CERN SPS. These data are required to improve predictions of the neutrino flux for the T2K long baseline neutrino oscillation experiment in Japan. A set of data collected during the first NA61/SHINE run in 2007 with an isotropic graphite target with a thickness of 4% of a nuclear interaction length was used for the analysis. The measured p+C inelastic and production cross sections are 257.2 +- 1.9 +- 8.9 mb and 229.3 +- 1.9 +- 9.0 mb, respectively. Inclusive production cross sections for negatively and positively charged pions are presented as a function of laboratory momentum in 10 intervals of the laboratory polar angle covering the range from 0 up to 420 mrad. The spectra are compared with predictions of several hadron production models.

  8. The covariance of the differences between experimental and theoretical chemical shifts as an aid for assigning two-dimensional heteronuclear correlation solid-state NMR spectra

    Czech Academy of Sciences Publication Activity Database

    Czernek, Jiří; Brus, Jiří

    2014-01-01

    Roč. 608, 21 July (2014), s. 334-339 ISSN 0009-2614 R&D Projects: GA ČR(CZ) GA14-03636S Institutional support: RVO:61389013 Keywords : NMR * DFT * covariance Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.897, year: 2014

  9. NMR study of hyper-polarized 129Xe and applications to liquid-phase NMR experiments

    International Nuclear Information System (INIS)

    Marion, D.

    2008-07-01

    In liquid samples where both nuclear polarization and spin density are strong, the magnetization dynamics, which can be analysed by NMR (nuclear magnetic resonance) methods, is deeply influenced by the internal couplings induced by local dipolar fields. The present thesis describes some of the many consequences associated to the presence in the sample of concentrated xenon hyper-polarized by an optical pumping process. First, we deal with the induced modifications in frequency and line width of the proton and xenon spectra, then we present the results of SPIDER, a coherent polarization transfer experiment designed to enhance the polarization of protons, in order to increase their NMR signal level. A third part is dedicated to the description of the apparition of repeated chaotic maser emissions by un unstable xenon magnetization coupled to the detection coil tuned at the xenon Larmor frequency (here 138 MHz). In the last part, we present a new method allowing a better tuning of any NMR detection probe and resulting in sensible gains in terms of sensitivity and signal shaping. Finally, we conclude with a partial questioning of the classical relaxation theory in the specific field of highly polarized and concentrated spin systems in a liquid phase. (author)

  10. Structure determination of cyclo pentane terpene derivatives by crossed NMR and MS techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pianet, I.; Bourgeois, G. [Bordeaux-1 Univ., 33 - Talence (France); Dolatkhani, M.; Cramail, H.; Deffieux, A. [Centre National de la Recherche Scientifique (CNRS), 33 - Talence (France)

    1995-10-01

    3 of the 4 stereoisomers of the 1-isopropenyl 2,3-dimethylcyclopentane, obtained from the cracking of 3,7-dimethylocta-1,6-diene, were purified and characterized. Dihedral angles, between the protons of the substituted carbons, have been determined by molecular modelling. Analysis of the NMR and mass spectra allowed us to access to the structure of the different isomers. (authors). 6 refs., 2 tabs.

  11. Modification and intercalation of layered zirconium phosphates: a solid-state NMR monitoring.

    Science.gov (United States)

    Bakhmutov, Vladimir I; Kan, Yuwei; Sheikh, Javeed Ahmad; González-Villegas, Julissa; Colón, Jorge L; Clearfield, Abraham

    2017-07-01

    Several layered zirconium phosphates treated with Zr(IV) ions, modified by monomethoxy-polyethyleneglycol-monophosphate and intercalated with doxorubicin hydrochloride have been studied by solid-state MAS NMR techniques. The organic components of the phosphates have been characterized by the 13 C{ 1 H} CP MAS NMR spectra compared with those of initial compounds. The multinuclear NMR monitoring has provided to establish structure and covalent attachment of organic/inorganic moieties to the surface and interlayer spaces of the phosphates. The MAS NMR experiments including kinetics of proton-phosphorus cross polarization have resulted in an unusual structure of zirconium phosphate 6 combining decoration of the phosphate surface by polymer units and their partial intercalation into the interlayer space. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  12. High-performance liquid chromatography on-line coupled to high-field NMR and mass spectrometry for structure elucidation of constituents of Hypericum perforatum L

    DEFF Research Database (Denmark)

    Hansen, S. H.; Jensen, A. G.; Cornett, Claus

    1999-01-01

    The on-line separation and structure elucidation of naphthodianthrones, flavonoids, and other constituents of an extract from Hypericum perforatum L, using high performance liquid chromatography (HPLC) coupled on-line with ultraviolet-visible, nuclear magnetic resonance (NMR), and mass spectrometry...... (MS) is described. A conventional reversed-phase HPLC system using ammonium acetate as the buffer substance in the eluent tvas used, and proton NMR spectra were obtained on a 500 MHz NMR instrument. The MS and MS/MS analyses were performed using negative electrospray ionization, In the present study...

  13. Combining Fourier phase encoding and broadband inversion toward J-edited spectra

    Science.gov (United States)

    Lin, Yulan; Guan, Quanshuai; Su, Jianwei; Chen, Zhong

    2018-06-01

    Nuclear magnetic resonance (NMR) spectra are often utilized for gathering accurate information relevant to molecular structures and composition assignments. In this study, we develop a homonuclear encoding approach based on imparting a discrete phase modulation of the targeted cross peaks, and combine it with a pure shift experiments (PSYCHE) based J-modulated scheme, providing simple 2D J-edited spectra for accurate measurement of scalar coupling networks. Chemical shifts and J coupling constants of protons coupled to the specific protons are demonstrated along the F2 and F1 dimensions, respectively. Polychromatic pulses by Fourier phase encoding were performed to simultaneously detect several coupling networks. Proton-proton scalar couplings are chosen by a polychromatic pulse and a PSYCHE element. Axis peaks and unwanted couplings are complete eradicated by incorporating a selective COSY block as a preparation period. The theoretical principles and the signal processing procedure are laid out, and experimental observations are rationalized on the basis of theoretical analyses.

  14. 1H NMR spectra of N-methyl-4-tolyl-1-(4-bromonaphthylamine and N-phenyl-1-(4-bromonaphthylamine: a combined experimental and theoretical study

    Directory of Open Access Journals (Sweden)

    Sergiy I. Okovytyy

    2014-03-01

    Full Text Available Theoretical investigations of the conformational properties and 1H NMR chemical shifts for N-methyl-4-tolyl-1-(4-bromonaphthylamine and N-phenyl-1-(4-bromonaphthylamine are reported. The calculations were performed at the DFT level (PBE1PBE functional using magnetically consistent 6-31G## and STO##-3Gmag basis sets. Conformational properties of the amines were studied using potential energy surface scanning. Chemical shifts were calculated using the GIAO and CSGT methods and averaged in proportion to the population of the corresponding conformations. Solvent effects (CDCl3 were accounted via PCM method. The obtained results allowed to assign the 1H NMR signals for the naphthalene moiety, which could not be done based on the experimental data alone.

  15. Behaviour of 29Si NMR and infrared spectra of aqueous sodium and potassium silica solutions as a function of (SiO2/M2+O) ratio

    International Nuclear Information System (INIS)

    Couty, R.; Fernandez, L.

    1996-01-01

    Sodium and potassium solutions of silica with silica concentration of 1,4 mo/kg and R ms = SiO 2 /M + 2 O ratios of 4.56 to 1.6 were obtained by depolymerization of amorphous silica gel in sodium and potassium hydroxide. Solutions have been characterized by 29 Si NMR and infrared spectroscopy. The results indicated that Na + and K + exhibit the same behaviour during the depolymerization of silica. (authors). 11 refs., 4 figs., 2 tabs

  16. Magic Angle Spinning NMR Metabolomics

    Energy Technology Data Exchange (ETDEWEB)

    Zhi Hu, Jian

    2016-01-01

    Nuclear Magnetic Resonance (NMR) spectroscopy is a non-destructive, quantitative, reproducible, untargeted and unbiased method that requires no or minimal sample preparation, and is one of the leading analytical tools for metabonomics research [1-3]. The easy quantification and the no need of prior knowledge about compounds present in a sample associated with NMR are advantageous over other techniques [1,4]. 1H NMR is especially attractive because protons are present in virtually all metabolites and its NMR sensitivity is high, enabling the simultaneous identification and monitoring of a wide range of low molecular weight metabolites.

  17. Relationships Between Base-Catalyzed Hydrolysis Rates or Glutathione Reactivity for Acrylates and Methacrylates and Their NMR Spectra or Heat of Formation

    Directory of Open Access Journals (Sweden)

    Yoshinori Kadoma

    2012-05-01

    Full Text Available The NMR chemical shift, i.e., the π-electron density of the double bond, of acrylates and methacrylates is related to the reactivity of their monomers. We investigated quantitative structure-property relationships (QSPRs between the base-catalyzed hydrolysis rate constants (k1 or the rate constant with glutathione (GSH (log kGSH for acrylates and methacrylates and the 13C NMR chemical shifts of their α,β-unsaturated carbonyl groups (δCα and δCβ or heat of formation (Hf calculated by the semi-empirical MO method. Reported data for the independent variables were employed. A significant linear relationship between k1 and δCβ, but not δCα, was obtained for methacrylates (r2 = 0.93, but not for acrylates. Also, a significant relationship between k1 and Hf was obtained for both acrylates and methacrylates (r2 = 0.89. By contrast, log kGSH for acrylates and methacrylates was linearly related to their δCβ (r2 = 0.99, but not to Hf. These findings indicate that the 13C NMR chemical shifts and calculated Hf values for acrylates and methacrylates could be valuable for estimating the hydrolysis rate constants and GSH reactivity of these compounds. Also, these data for monomers may be an important tool for examining mechanisms of reactivity.

  18. A novel in situ electrochemical NMR cell with a palisade gold film electrode

    Science.gov (United States)

    Ni, Zu-Rong; Cui, Xiao-Hong; Cao, Shuo-Hui; Chen, Zhong

    2017-08-01

    In situ electrochemical nuclear magnetic resonance (EC-NMR) has attracted considerable attention because of its ability to directly observe real-time electrochemical processes. Therefore, minimizing the incompatibility between the electrochemical device and NMR detection has become an important challenge. A circular thin metal film deposited on the outer surface of a glass tube with a thickness considerably less than the metal skin depth is considered to be the ideal working electrode. In this study, we demonstrate that such a thin film electrode still has a great influence on the radio frequency field homogeneity in the detective zone of the NMR spectrometer probe and provide theoretical and experimental confirmation of its electromagnetic shielding. Furthermore, we propose a novel palisade gold film device to act as the working electrode. The NMR nutation behavior of protons shows that the uniformity of the radio frequency field is greatly improved, increasing the sensitivity in NMR detection. Another advantage of the proposed device is that an external reference standard adapted to the reaction compound can be inserted as a probe to determine the fluctuation of the physico-chemical environment and achieve high-accuracy quantitative NMR analysis. A three-chamber electrochemical device based on the palisade gold film design was successfully fabricated and the in situ electrochemical NMR performance was validated in a standard 5 mm NMR probe by acquiring voltammograms and high-resolution NMR spectra to characterize the electrochemically generated species. The evolution of in situ EC-NMR spectrum monitoring of the redox transformation between p-benzoquinone and hydroquinone demonstrates the ability of the EC-NMR device to simultaneously quantitatively determine the reactants and elucidate the reaction mechanism at the molecular level.

  19. A novel in situ electrochemical NMR cell with a palisade gold film electrode

    Directory of Open Access Journals (Sweden)

    Zu-Rong Ni

    2017-08-01

    Full Text Available In situ electrochemical nuclear magnetic resonance (EC-NMR has attracted considerable attention because of its ability to directly observe real-time electrochemical processes. Therefore, minimizing the incompatibility between the electrochemical device and NMR detection has become an important challenge. A circular thin metal film deposited on the outer surface of a glass tube with a thickness considerably less than the metal skin depth is considered to be the ideal working electrode. In this study, we demonstrate that such a thin film electrode still has a great influence on the radio frequency field homogeneity in the detective zone of the NMR spectrometer probe and provide theoretical and experimental confirmation of its electromagnetic shielding. Furthermore, we propose a novel palisade gold film device to act as the working electrode. The NMR nutation behavior of protons shows that the uniformity of the radio frequency field is greatly improved, increasing the sensitivity in NMR detection. Another advantage of the proposed device is that an external reference standard adapted to the reaction compound can be inserted as a probe to determine the fluctuation of the physico-chemical environment and achieve high-accuracy quantitative NMR analysis. A three-chamber electrochemical device based on the palisade gold film design was successfully fabricated and the in situ electrochemical NMR performance was validated in a standard 5 mm NMR probe by acquiring voltammograms and high-resolution NMR spectra to characterize the electrochemically generated species. The evolution of in situ EC-NMR spectrum monitoring of the redox transformation between p-benzoquinone and hydroquinone demonstrates the ability of the EC-NMR device to simultaneously quantitatively determine the reactants and elucidate the reaction mechanism at the molecular level.

  20. Primary proton and helium spectra at energy range from 50 TeV to 1015 eV observed with the new Tibet AS core detector array

    Directory of Open Access Journals (Sweden)

    Huang Jing

    2013-06-01

    Full Text Available A new EAS hybrid experiment has been designed by constructing a YAC (Yangbajing Air shower Core detector array inside the existing Tibet-III air shower array. The first step of YAC, called “YAC-I” has been successfully carried out in 2009–2010 together with Tibet-III air-shower array. YAC-II has also been operated from 2011. Preliminary results of YAC-I and performance of YAC-II are presented in this paper. The primary proton and helium spectra at energy range from50 TeV to 1015 eV derived from YAC-I data based on QGSJET2 and SIBYLL2.1 are reported. The obtained P+He spectrum is smoothly connected with directobservation data below 100 TeV and also with our previously reported results at higher energies within statistical error s. Based on these results and the sharp kneeof all-particle energy spectrum observed by our experiment, the possible origin of the sharp knee is discussed. See the published papers.

  1. The importance of including local correlation times in the calculation of inter-proton distances from NMR measurements: ignoring local correlation times leads to significant errors in the conformational analysis of the Glc alpha1-2Glc alpha linkage by NMR spectroscopy.

    Science.gov (United States)

    Mackeen, Mukram; Almond, Andrew; Cumpstey, Ian; Enis, Seth C; Kupce, Eriks; Butters, Terry D; Fairbanks, Antony J; Dwek, Raymond A; Wormald, Mark R

    2006-06-07

    The experimental determination of oligosaccharide conformations has traditionally used cross-linkage 1H-1H NOE/ROEs. As relatively few NOEs are observed, to provide sufficient conformational constraints this method relies on: accurate quantification of NOE intensities (positive constraints); analysis of absent NOEs (negative constraints); and hence calculation of inter-proton distances using the two-spin approximation. We have compared the results obtained by using 1H 2D NOESY, ROESY and T-ROESY experiments at 500 and 700 MHz to determine the conformation of the terminal Glc alpha1-2Glc alpha linkage in a dodecasaccharide and a related tetrasaccharide. For the tetrasaccharide, the NOESY and ROESY spectra produced the same qualitative pattern of linkage cross-peaks but the quantitative pattern, the relative peak intensities, was different. For the dodecasaccharide, the NOESY and ROESY spectra at 500 MHz produced a different qualitative pattern of linkage cross-peaks, with fewer peaks in the NOESY spectrum. At 700 MHz, the NOESY and ROESY spectra of the dodecasaccharide produced the same qualitative pattern of peaks, but again the relative peak intensities were different. These differences are due to very significant differences in the local correlation times for different proton pairs across this glycosidic linkage. The local correlation time for each proton pair was measured using the ratio of the NOESY and T-ROESY cross-relaxation rates, leaving the NOESY and ROESY as independent data sets for calculating the inter-proton distances. The inter-proton distances calculated including the effects of differences in local correlation times give much more consistent results.

  2. NMR metabolomics for assessment of exercise effects with mouse biofluids

    Energy Technology Data Exchange (ETDEWEB)

    Le Moyec, Laurence; Mille-Hamard, Laurence; Breuneval, Carole; Petot, Helene; Billat, Veronique L. [Universite Evry Val d' Essonne, UBIAE INSERM U902, Evry Cedex (France); Triba, Mohamed N. [Universite Paris 13, CSPBAT UMR 7244, Bobigny (France)

    2012-08-15

    Exercise modulates the metabolome in urine or blood as demonstrated previously for humans and animal models. Using nuclear magnetic resonance (NMR) metabolomics, the present study compares the metabolic consequences of an exhaustive exercise at peak velocity (Vp) and at critical velocity (Vc) on mice. Since small-volume samples (blood and urine) were collected, dilution was necessary to acquire NMR spectra. Consequently, specific processing methods were applied before statistical analysis. According to the type of exercise (control group, Vp group and Vc group), 26 male mice were divided into three groups. Mice were sacrificed 2 h after the end of exercise, and urine and blood samples were drawn from each mouse. Proton NMR spectra were acquired with urine and deproteinized blood. The NMR data were aligned with the icoshift method and normalised using the probabilistic quotient method. Finally, data were analysed with the orthogonal projection of latent-structure analysis. The spectra obtained with deproteinized blood can neither discriminate the control mice from exercised mice nor discriminate according to the duration of the exercise. With urine samples, a significant statistical model can be estimated when comparing the control mice to both groups, Vc and Vp. The best model is obtained according to the exercise duration with all mice. Taking into account the spectral regions having the highest correlations, the discriminant metabolites are allantoin, inosine and branched-chain amino acids. In conclusion, metabolomic profiles assessed with NMR are highly dependent on the exercise. These results show that urine samples are more informative than blood samples and that the duration of the exercise is a more important parameter to influence the metabolomic status than the exercise velocity. (orig.)

  3. Elucidation of the CCR1- and CCR5-binding modes of MIP-1α by application of an NMR spectra reconstruction method to the transferred cross-saturation experiments

    Energy Technology Data Exchange (ETDEWEB)

    Yoshiura, Chie; Ueda, Takumi; Kofuku, Yutaka; Matsumoto, Masahiko; Okude, Junya; Kondo, Keita; Shiraishi, Yutaro; Shimada, Ichio, E-mail: shimada@iw-nmr.f.u-tokyo.ac.jp [The University of Tokyo, Graduate School of Pharmaceutical Sciences (Japan)

    2015-12-15

    C–C chemokine receptor 1 (CCR1) and CCR5 are involved in various inflammation and immune responses, and regulate the progression of the autoimmune diseases differently. However, the number of residues identified at the binding interface was not sufficient to clarify the differences in the CCR1- and CCR5-binding modes to MIP-1α, because the NMR measurement time for CCR1 and CCR5 samples was limited to 24 h, due to their low stability. Here we applied a recently developed NMR spectra reconstruction method, Conservation of experimental data in ANAlysis of FOuRier, to the amide-directed transferred cross-saturation experiments of chemokine receptors, CCR1 and CCR5, embedded in lipid bilayers of the reconstituted high density lipoprotein, and MIP-1α. Our experiments revealed that the residues on the N-loop and β-sheets of MIP-1α are close to both CCR1 and CCR5, and those in the C-terminal helix region are close to CCR5. These results suggest that the genetic influence of the single nucleotide polymorphisms of MIP-1α that accompany substitution of residues in the C-terminal helix region, E57 and V63, would provide clues toward elucidating how the CCR5–MIP-1α interaction affects the progress of autoimmune diseases.

  4. Coherent evolution of parahydrogen induced polarisation using laser pump, NMR probe spectroscopy: Theoretical framework and experimental observation.

    Science.gov (United States)

    Halse, Meghan E; Procacci, Barbara; Henshaw, Sarah-Louise; Perutz, Robin N; Duckett, Simon B

    2017-05-01

    We recently reported a pump-probe method that uses a single laser pulse to introduce parahydrogen (p-H 2 ) into a metal dihydride complex and then follows the time-evolution of the p-H 2 -derived nuclear spin states by NMR. We present here a theoretical framework to describe the oscillatory behaviour of the resultant hyperpolarised NMR signals using a product operator formalism. We consider the cases where the p-H 2 -derived protons form part of an AX, AXY, AXYZ or AA'XX' spin system in the product molecule. We use this framework to predict the patterns for 2D pump-probe NMR spectra, where the indirect dimension represents the evolution during the pump-probe delay and the positions of the cross-peaks depend on the difference in chemical shift of the p-H 2 -derived protons and the difference in their couplings to other nuclei. The evolution of the NMR signals of the p-H 2 -derived protons, as well as the transfer of hyperpolarisation to other NMR-active nuclei in the product, is described. The theoretical framework is tested experimentally for a set of ruthenium dihydride complexes representing the different spin systems. Theoretical predictions and experimental results agree to within experimental error for all features of the hyperpolarised 1 H and 31 P pump-probe NMR spectra. Thus we establish the laser pump, NMR probe approach as a robust way to directly observe and quantitatively analyse the coherent evolution of p-H 2 -derived spin order over micro-to-millisecond timescales. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  5. NMR and TRLFS studies of Ln(iii) and An(iii) C5-BPP complexes† †Electronic supplementary information (ESI) available: LIFDI-MS spectra and additional NMR spectra. See DOI: 10.1039/c4sc03103b

    Science.gov (United States)

    Beele, Björn B.; Geist, Andreas; Müllich, Udo; Kaden, Peter; Panak, Petra J.

    2015-01-01

    C5-BPP is a highly efficient N-donor ligand for the separation of trivalent actinides, An(iii), from trivalent lanthanides, Ln(iii). The molecular origin of the selectivity of C5-BPP and many other N-donor ligands of the BTP-type is still not entirely understood. We present here the first NMR studies on C5-BPP Ln(iii) and An(iii) complexes. C5-BPP is synthesized with 10% 15N labeling and characterized by NMR and LIFDI-MS methods. 15N NMR spectroscopy gives a detailed insight into the bonding of C5-BPP with lanthanides and Am(iii) as a representative for trivalent actinide cations, revealing significant differences in 15N chemical shift for coordinating nitrogen atoms compared to Ln(iii) complexes. The temperature dependence of NMR chemical shifts observed for the Am(iii) complex indicates a weak paramagnetism. This as well as the observed large chemical shift for coordinating nitrogen atoms show that metal–ligand bonding in Am(C5-BPP)3 has a larger share of covalence than in lanthanide complexes, confirming earlier studies. The Am(C5-BPP)3 NMR sample is furthermore spiked with Cm(iii) and characterized by time-resolved laser fluorescence spectroscopy (TRLFS), yielding important information on the speciation of trace amounts of minor complex species. PMID:29560242

  6. Metabolic trajectories based on 1H NMR spectra of urines from sheep exposed to nutritional challenges during prenatal and early postnatal life

    DEFF Research Database (Denmark)

    Nyberg, Nils; Nielsen, Mette Benedicte Olaf; Jaroszewski, Jerzy W.

    2010-01-01

    1H NMR metabolic profiles of urine from sheep exposed to prenatal nutritional restriction (n = 19) and a control group with normal prenatal nutritional requirements (n = 19), followed by either conventional (n = 10 + 10) or high carbohydrate high fat postnatal diet (n = 9 + 9), were studied. Urine...... undernutrition followed by normal postnatal diet showed metabolic patters that are ahead in time on the metabolic trajectory relative to the prenatal control group. No long-term effects of fetal undernutrition, alone or in combination with postnatal hypernutrition were observed....... amount of glucose, indicative of monogastric-like metabolism, and exhibiting concomitant increase of metabolites related to rumen microflora (mainly glycine conjugates of benzoic and phenylacetic acid) as the ruminal metabolism developed. Urines from young (2-month-old) animals exposed to prenatal...

  7. Preparation, infrared, raman and nmr spectra of N,N'-diethylthiourea complexes with zinc(II), cadmium(II) and mercury(II) halides

    Energy Technology Data Exchange (ETDEWEB)

    Marcotrigiano, G [Bari Univ. (Italy). Cattedra di Chimica, Facolta di Medicina-Veterinaria

    1976-05-01

    Several complexes of N,N'-diethylthiourea (Dietu) with zinc(II), cadmium(II) and mercury(II) halides were prepared and characterized by i.r. (4000-60 cm/sup -1/), raman (400-60 cm/sup -1/), in the solid state and n.m.r. and conductometric methods in solution. The complexes Zn(Dietu)/sub 2/X/sub 2/, Cd(Dietu)/sub 2/X/sub 2/ (X=Cl, Br, I) and Hg(Dietu)/sub 2/X/sub 2/ (X=Br, I) are tetrahedral species in which intramolecular -NH...X interactions have been observed. The 1:1 mercury(II) complexes, Hg(Dietu)X/sub 2/ (X=Cl, Br), appear to have a dimeric tetrahedral halide-bridged structure in the solid state. In all these complexes N,N'-diethylthiourea is sulphur-bonded to the metal.

  8. Solid state NMR of proteins at high MAS frequencies: symmetry-based mixing and simultaneous acquisition of chemical shift correlation spectra

    International Nuclear Information System (INIS)

    Bellstedt, Peter; Herbst, Christian; Häfner, Sabine; Leppert, Jörg; Görlach, Matthias; Ramachandran, Ramadurai

    2012-01-01

    We have carried out chemical shift correlation experiments with symmetry-based mixing sequences at high MAS frequencies and examined different strategies to simultaneously acquire 3D correlation spectra that are commonly required in the structural studies of proteins. The potential of numerically optimised symmetry-based mixing sequences and the simultaneous recording of chemical shift correlation spectra such as: 3D NCAC and 3D NHH with dual receivers, 3D NC′C and 3D C′NCA with sequential 13 C acquisitions, 3D NHH and 3D NC′H with sequential 1 H acquisitions and 3D CANH and 3D C’NH with broadband 13 C– 15 N mixing are demonstrated using microcrystalline samples of the β1 immunoglobulin binding domain of protein G (GB1) and the chicken α-spectrin SH3 domain.

  9. Solid state NMR of proteins at high MAS frequencies: symmetry-based mixing and simultaneous acquisition of chemical shift correlation spectra

    Energy Technology Data Exchange (ETDEWEB)

    Bellstedt, Peter [Fritz Lipmann Institute, Biomolecular NMR spectroscopy, Leibniz Institute for Age Research (Germany); Herbst, Christian [Ubon Ratchathani University, Department of Physics, Faculty of Science (Thailand); Haefner, Sabine; Leppert, Joerg; Goerlach, Matthias; Ramachandran, Ramadurai, E-mail: raman@fli-leibniz.de [Fritz Lipmann Institute, Biomolecular NMR spectroscopy, Leibniz Institute for Age Research (Germany)

    2012-12-15

    We have carried out chemical shift correlation experiments with symmetry-based mixing sequences at high MAS frequencies and examined different strategies to simultaneously acquire 3D correlation spectra that are commonly required in the structural studies of proteins. The potential of numerically optimised symmetry-based mixing sequences and the simultaneous recording of chemical shift correlation spectra such as: 3D NCAC and 3D NHH with dual receivers, 3D NC Prime C and 3D C Prime NCA with sequential {sup 13}C acquisitions, 3D NHH and 3D NC Prime H with sequential {sup 1}H acquisitions and 3D CANH and 3D C'NH with broadband {sup 13}C-{sup 15}N mixing are demonstrated using microcrystalline samples of the {beta}1 immunoglobulin binding domain of protein G (GB1) and the chicken {alpha}-spectrin SH3 domain.

  10. The n,{gamma} discrimination in recoil-proton proportional counters. Application to the measurement of fast neutron spectra; Discrimination n,{gamma} dans les compteurs proportionnels a protons de recul. Application a la mesure des spectres de neutrons rapides

    Energy Technology Data Exchange (ETDEWEB)

    Jeandidier, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    A description is given of a spectrometry chain working in the energy range of a few keV to 1 MeV, and designed for measurement of fast neutron spectra. It consists of detectors, recoil proton proportional counters built especially for this work by R. COMTE (DEG/SER) and which make it possible to cover the energy range and also associated electronic equipment. A brief description is first given of the physical processes involved: (n,p) collisions in the gas, influence of {gamma} radiation; the method of discrimination is then presented. It is based on the difference in the rise-times of the pulses. In the experiments described here the use of a bi-parametric system made it possible to employ the most simple discrimination device, based on the fact that the high frequency gamma pulse components are, at a given energy, weaker than those of the neutron pulses. Results are given of measurements carried out on the Van der Graaff (mono-energetic neutrons for testing the linearity of the chain and the resolving power of the counters), and of those made in a sub-critical system Hug at Cadarache. (author) [French] On decrit une chaine de spectrometrie travaillant dans le domaine d'energie de quelques keV a 1 MeV destinee a la mesure des spectres de neutrons rapides. Elle comprend les detecteurs, compteurs proportionnels a protons de recul, realises specialement pour cette etude par M. R. COMTE (DEG/SER), permettant de couvrir la gamme d'energie et l'electronique associee. Apres un rappel des processus physiques mis en jeu: chocs (n,p) dans les gaz, influence des rayonnements {gamma}, on expose la methode de discrimination utilisee. Celle-ci est basee sur la difference des temps de montee des impulsions. Au cours des experiences rapportees ici, la mise en oeuvre d'un ensemble bi-parametrique a permis d'utiliser le dispositif de discrimination le plus simple, base sur la remarque que les composantes a haute frequence des impulsions {gamma} sont, a energie egale, plus faibles

  11. The n,{gamma} discrimination in recoil-proton proportional counters. Application to the measurement of fast neutron spectra; Discrimination n,{gamma} dans les compteurs proportionnels a protons de recul. Application a la mesure des spectres de neutrons rapides

    Energy Technology Data Exchange (ETDEWEB)

    Jeandidier, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    A description is given of a spectrometry chain working in the energy range of a few keV to 1 MeV, and designed for measurement of fast neutron spectra. It consists of detectors, recoil proton proportional counters built especially for this work by R. COMTE (DEG/SER) and which make it possible to cover the energy range and also associated electronic equipment. A brief description is first given of the physical processes involved: (n,p) collisions in the gas, influence of {gamma} radiation; the method of discrimination is then presented. It is based on the difference in the rise-times of the pulses. In the experiments described here the use of a bi-parametric system made it possible to employ the most simple discrimination device, based on the fact that the high frequency gamma pulse components are, at a given energy, weaker than those of the neutron pulses. Results are given of measurements carried out on the Van der Graaff (mono-energetic neutrons for testing the linearity of the chain and the resolving power of the counters), and of those made in a sub-critical system Hug at Cadarache. (author) [French] On decrit une chaine de spectrometrie travaillant dans le domaine d'energie de quelques keV a 1 MeV destinee a la mesure des spectres de neutrons rapides. Elle comprend les detecteurs, compteurs proportionnels a protons de recul, realises specialement pour cette etude par M. R. COMTE (DEG/SER), permettant de couvrir la gamme d'energie et l'electronique associee. Apres un rappel des processus physiques mis en jeu: chocs (n,p) dans les gaz, influence des rayonnements {gamma}, on expose la methode de discrimination utilisee. Celle-ci est basee sur la difference des temps de montee des impulsions. Au cours des experiences rapportees ici, la mise en oeuvre d'un ensemble bi-parametrique a permis d'utiliser le dispositif de discrimination le plus simple, base sur la remarque que les composantes a haute frequence des impulsions {gamma} sont, a

  12. NMR, water and plants

    International Nuclear Information System (INIS)

    As, H. van.

    1982-01-01

    This thesis describes the application of a non-destructive pulsed proton NMR method mainly to measure water transport in the xylem vessels of plant stems and in some model systems. The results are equally well applicable to liquid flow in other biological objects than plants, e.g. flow of blood and other body fluids in human and animals. The method is based on a pulse sequence of equidistant π pulses in combination with a linear magnetic field gradient. (Auth.)

  13. Search for narrow resonances in dilepton mass spectra in proton–proton collisions at s=13 TeV and combination with 8 TeV data

    Directory of Open Access Journals (Sweden)

    V. Khachatryan

    2017-05-01

    Full Text Available A search for narrow resonances in dielectron and dimuon invariant mass spectra has been performed using data obtained from proton–proton collisions at s=13 TeV collected with the CMS detector. The integrated luminosity for the dielectron sample is 2.7 fb−1 and for the dimuon sample 2.9 fb−1. The sensitivity of the search is increased by combining these data with a previously analyzed set of data obtained at s=8 TeV and corresponding to a luminosity of 20 fb−1. No evidence for non-standard-model physics is found, either in the 13 TeV data set alone, or in the combined data set. Upper limits on the product of production cross section and branching fraction have also been calculated in a model-independent manner to enable interpretation in models predicting a narrow dielectron or dimuon resonance structure. Limits are set on the masses of hypothetical particles that could appear in new-physics scenarios. For the ZSSM′ particle, which arises in the sequential standard model, and for the superstring inspired Zψ′ particle, 95% confidence level lower mass limits for the combined data sets and combined channels are found to be 3.37 and 2.82 TeV, respectively. The corresponding limits for the lightest Kaluza–Klein graviton arising in the Randall–Sundrum model of extra dimensions with coupling parameters 0.01 and 0.10 are 1.46 and 3.11 TeV, respectively. These results significantly exceed the limits based on the 8 TeV LHC data.

  14. Protonation constant of salicylidene (N-benzoyl)glycyl hydrazone ...

    Indian Academy of Sciences (India)

    Unknown

    ductance, magnetic susceptibility, electronic, IR, ESR, XRD (powder) and NMR studies have been car ... IR and NMR spectra suggest the tri- .... and dried at room temperature. ..... IR and NMR data can be seen on the web version of this paper.

  15. FT-IR, FT-Raman, NMR spectra, density functional computations of the vibrational assignments (for monomer and dimer) and molecular geometry of anticancer drug 7-amino-2-methylchromone

    Science.gov (United States)

    Mariappan, G.; Sundaraganesan, N.

    2014-04-01

    Vibrational assignments for the 7-amino-2-methylchromone (abbreviated as 7A2MC) molecule using a combination of experimental vibrational spectroscopic measurements and ab initio computational methods are reported. The optimized geometry, intermolecular hydrogen bonding, first order hyperpolarizability and harmonic vibrational wavenumbers of 7A2MC have been investigated with the help of B3LYP density functional theory method. The calculated molecular geometry parameters, the theoretically computed vibrational frequencies for monomer and dimer and relative peak intensities were compared with experimental data. DFT calculations using the B3LYP method and 6-31 + G(d,p) basis set were found to yield results that are very comparable to experimental IR and Raman spectra. Detailed vibrational assignments were performed with DFT calculations and the potential energy distribution (PED) obtained from the Vibrational Energy Distribution Analysis (VEDA) program. Natural Bond Orbital (NBO) study revealed the characteristics of the electronic delocalization of the molecular structure. 13C and 1H NMR spectra have been recorded and 13C and 1H nuclear magnetic resonance chemical shifts of the molecule have been calculated using the gauge independent atomic orbital (GIAO) method. Furthermore, All the possible calculated values are analyzed using correlation coefficients linear fitting equation and are shown strong correlation with the experimental data.

  16. GEANT4 hadronic cascade models analysis of proton and charged pion transverse momentum spectra from p plus Cu and Pb collisions at 3, 8, and 15 GeV/c

    CERN Document Server

    Abdel-Waged, Khaled; Uzhinskii, V V

    2011-01-01

    We describe how various hadronic cascade models, which are implemented in the GEANT4 toolkit, describe proton and charged pion transverse momentum spectra from p + Cu and Pb collisions at 3, 8, and 15 GeV/c, recently measured in the hadron production (HARP) experiment at CERN. The Binary, ultrarelativistic quantum molecular dynamics (UrQMD) and modified FRITIOF (FTF) hadronic cascade models are chosen for investigation. The first two models are based on limited (Binary) and branched (UrQMD) binary scattering between cascade particles which can be either a baryon or meson, in the three-dimensional space of the nucleus, while the latter (FTF) considers collective interactions between nucleons only, on the plane of impact parameter. It is found that the slow (p(T) 0.3 GeV/c) proton spectra are not strongly affected by the differences between the FTF and UrQMD models. It is also shown that the UrQMD and FTF combined with Binary (FTFB) models could reproduce both proton and charged pion spectra from p + Cu and Pb...

  17. Structural investigations of substituted indolizine derivatives by NMR studies

    International Nuclear Information System (INIS)

    Furdui, Bianca; Dinica, Rodica; Demeunynck, Martine; Druta, Ioan

    2008-01-01

    Owing to the increasing importance of indolizine heterocycles in the field of biology and pharmacology we have synthesized and investigated the obtained heterocycles by NMR techniques. In order to investigate the substituent effects on the spectroscopic properties, a series of indolizine derivatives were studied by 1 H-NMR, 13 C-NMR and 2D NMR (GCOSY, GHMBC and GHMQC spectra). (authors)

  18. Complete sequence-specific 1H NMR assignments for human insulin

    International Nuclear Information System (INIS)

    Kline, A.D.; Justice, R.M. Jr.

    1990-01-01

    Solvent conditions where human insulin could be studied by high-resolution NMR were determined. Both low pH and addition of acetonitrile were required to overcome the protein's self-association and to obtain useful spectra. Two hundred eighty-six 1 H resonances were located and assigned to specific sites on the protein by using two-dimensional NMR methods. The presence and position of numerous d NN sequential NOE's indicate that the insulin conformation seen in crystallographic studies is largely retained under these solution conditions. Slowly exchanging protons were observed for seven backbone amide protons and were assigned to positions A15 and A16 and to positions B15-B19. These amides all occur within helical regions of the protein

  19. NMR comparison of prokaryotic and eukaryotic cytochromes c

    International Nuclear Information System (INIS)

    Chau, Meihing; Cai, Meng Li; Timkovich, R.

    1990-01-01

    1 H NMR spectroscopy has been used to examine ferrocytochrome c-551 from Pseudomonas aeruginosa (ATCC 19429) over the pH range 3.5-10.6 and the temperature range 4-60 degree C. Resonance assignments are proposed for main-chain and side-chain protons. Comparison of results for cytochrome c-551 to recently assigned spectra for horse cytochrome c and mutants of yeast iso-1 cytochrome reveals some unique resonances with unusual chemical shifts in all cytochromes that may serve as markers for the heme region. Results for cytochrome c-551 indicate that in the smaller prokaryotic cytochrome, all benzoid side chains are rapidly flipping on the NMR time scale. In contrast, in eukaryotic cytochromes there are some rings flipping slowly on the NMR time scale. The ferrocytochrome c-551 undergoes a transition linked to pH with a pK around 7. The pH behavior of assigned resonances provides evidence that the site of protonation is the inner or buried 17-propionic acid heme substituent (IUPAC-IUB porphyrin nomenclature). Conformational heterogeneity has been observed for segments near the inner heme propionate substituent

  20. pH control and rapid mixing in spinning NMR samples

    Science.gov (United States)

    Yesinowski, James P.; Sunberg, Richard J.; Benedict, James J.

    An apparatus is described which permits the acquisition of NMR spectra from spinning 20-mm sample tubes while: (1) constantly monitoring the pH; (2) adding reagents to maintain constant pH (pH-statting); (3) efficiently mixing the added reagent. The apparatus was built to study the spontaneous precipitation of calcium phosphates from supersaturated solutions using 31P NMR. Other applications include the rapid determination of NMR titration curves, and the minimization of temperature gradients in large sample tubes. The apparatus was used to measure the 31P chemical shift titration of dilute phosphoric acid, which yielded accurate shifts for the three species of protonated orthophosphate ion. The bulk magnetic susceptibility of 85% H 3PO 4 relative to a dilute aqueous sample was also measured, and is shown to contribute significantly to chemical shift measurements.

  1. Determination of the intracellular pH of intact erythrocytes by 1H NMR spectroscopy

    International Nuclear Information System (INIS)

    Rabenstein, D.L.; Isab, A.A.

    1982-01-01

    A method is described for determining the intracellular pH of intact erythrocytes by 1 H NMR. The determination is based on the pH dependence of the chemical shifts of resonances for carbon-bounded protons of an indicator molecule (imidazole) in intact cells. The imidazole is introduced into the erythrocytes by incubation in an isotonic saline solution of the indicator. The pH dependence of the chemical shifts of the imidazole resonances is calibrated from 1 H NMR spectra of the imidazole-containing red cell lysates whose pH is varied by the addition of acid or base and measured directly with a pH electrode. To reduce in intensity or eliminate the much more intense envelope of resonances from the hemoglobin, the 1 H NMR measurements are made by either the spin-echo Fourier transform technique or by the transfer-or-saturation by cross-relaxation method

  2. Tautomerism and the Protonation/Deprotonation of Isocytosine in Liquid- and Solid-States Studied by NMR Spectroscopy and Theoretical Calculations

    Czech Academy of Sciences Publication Activity Database

    Dračínský, Martin; Jansa, Petr; Ahonen, K.; Buděšínský, Miloš

    -, č. 8 (2011), s. 1544-1551 ISSN 1434-193X R&D Projects: GA AV ČR KJB400550903; GA MŠk 1M0508 Grant - others:AV ČR(CZ) M200380901 Institutional research plan: CEZ:AV0Z40550506 Keywords : NMR spectroscopy * tautomerism * nitrogen heterocycles * density functional calculations Subject RIV: CC - Organic Chemistry Impact factor: 3.329, year: 2011

  3. NMR studies of the solution conformation and dynamics of the tyrocidine peptide antibiotics

    International Nuclear Information System (INIS)

    Zhou, N.

    1985-01-01

    The tyrocidine B and tyrocidine C 1 H NMR spectra in DMSO-d 6 were assigned by using 2D 1 H- 1 H correlation spectroscopy and 1D double resonance experiments. Based on the proton chemical shifts, 3 J/sub NH-Nα/ coupling constants, the chemical shift temperature dependence, and 1D and 2D 1 H- 1 H NOE values, a backbone conformation consisting of an anti-parallel β-pleated sheet, a type I β-turn and a type II' β-turn was suggested for both tyrocidines B and C. Seven out of ten side chains were determined to exist predominantly in one classical Chi 1 rotamer; while the residues Val 1 and Leu 3 had two Chi 1 rotamers which were significantly populated. Chi 2 angles were determined for residues Phe 4 , Trp 6 , DPhe 7 (D Trp 7 ) and Asn 8 . The natural abundance 13 C spectra of tyrocidine B and tyrocidine C were assigned by using 1 H- 13 C correlation spectroscopy. A study of the effect of soluble paramagnetic nitroxide compounds on tyrocidine A proton T 1 values were performed which confirmed the proposed tyrocidine A conformation. It also proved that these nitroxide compounds are very useful in studying proton solvent exposure, and therefore in delineating hydrogen bonding. A proton NMR study of the opioid peptide dynorphin-(1-13) in aqueous solution was reported which was consistent with a non-ordered molecule in the solution

  4. Use of optimized 1D TOCSY NMR for improved quantitation and metabolomic analysis of biofluids

    International Nuclear Information System (INIS)

    Sandusky, Peter; Appiah-Amponsah, Emmanuel; Raftery, Daniel

    2011-01-01

    One dimensional selective TOCSY experiments have been shown to be advantageous in providing improved data inputs for principle component analysis (PCA) (Sandusky and Raftery 2005a, b). Better subpopulation cluster resolution in the observed scores plots results from the ability to isolate metabolite signals of interest via the TOCSY based filtering approach. This report reexamines the quantitative aspects of this approach, first by optimizing the 1D TOCSY experiment as it relates to the measurement of biofluid constituent concentrations, and second by comparing the integration of 1D TOCSY read peaks to the bucket integration of 1D proton NMR spectra in terms of precision and accuracy. This comparison indicates that, because of the extensive peak overlap that occurs in the 1D proton NMR spectra of biofluid samples, bucket integrals are often far less accurate as measures of individual constituent concentrations than 1D TOCSY read peaks. Even spectral fitting approaches have proven difficult in the analysis of significantly overlapped spectral regions. Measurements of endogenous taurine made over a sample population of human urine demonstrates that, due to background signals from other constituents, bucket integrals of 1D proton spectra routinely overestimate the taurine concentrations and distort its variation over the sample population. As a result, PCA calculations performed using data matrices incorporating 1D TOCSY determined taurine concentrations produce better scores plot subpopulation cluster resolution.

  5. Use of optimized 1D TOCSY NMR for improved quantitation and metabolomic analysis of biofluids

    Energy Technology Data Exchange (ETDEWEB)

    Sandusky, Peter [Eckerd College, Department of Chemistry (United States); Appiah-Amponsah, Emmanuel; Raftery, Daniel, E-mail: raftery@purdue.edu [Purdue University, Department of Chemistry (United States)

    2011-04-15

    One dimensional selective TOCSY experiments have been shown to be advantageous in providing improved data inputs for principle component analysis (PCA) (Sandusky and Raftery 2005a, b). Better subpopulation cluster resolution in the observed scores plots results from the ability to isolate metabolite signals of interest via the TOCSY based filtering approach. This report reexamines the quantitative aspects of this approach, first by optimizing the 1D TOCSY experiment as it relates to the measurement of biofluid constituent concentrations, and second by comparing the integration of 1D TOCSY read peaks to the bucket integration of 1D proton NMR spectra in terms of precision and accuracy. This comparison indicates that, because of the extensive peak overlap that occurs in the 1D proton NMR spectra of biofluid samples, bucket integrals are often far less accurate as measures of individual constituent concentrations than 1D TOCSY read peaks. Even spectral fitting approaches have proven difficult in the analysis of significantly overlapped spectral regions. Measurements of endogenous taurine made over a sample population of human urine demonstrates that, due to background signals from other constituents, bucket integrals of 1D proton spectra routinely overestimate the taurine concentrations and distort its variation over the sample population. As a result, PCA calculations performed using data matrices incorporating 1D TOCSY determined taurine concentrations produce better scores plot subpopulation cluster resolution.

  6. Sequence-specific assignments in the 1H NMR spectrum of the human inflammatory protein C5a

    International Nuclear Information System (INIS)

    Zuiderweg, E.R.P.; Mollison, K.W.; Henkin, J.; Carter, G.W.

    1988-01-01

    Full sequence-specific assignments for the 1 H NMR lines of the backbone protons of the human complement factor C5a are described and documented. The results were obtained by largely following the methodology developed by Wuethrich et al. Assignments for the majority of the amino acid side chain protons were obtained by using a comparison of double- and triple-quantum-filtered two-dimensional correlated experiments together with the analysis of relayed coherence transfer spectra. The assignments provide the basis for the determination of the thus far unknown three-dimensional structure of C5a from nuclear Overhauser enhancement distance constraints

  7. Synthesis, structural, spectroscopic, anti-cancer and molecular docking studies on novel 2-[(Anthracene-9-ylmethylene)amino]-2-methylpropane-1,3-diol using XRD, FTIR, NMR, UV-Vis spectra and DFT

    Science.gov (United States)

    Pavitha, P.; Prashanth, J.; Ramu, G.; Ramesh, G.; Mamatha, K.; Venkatram Reddy, Byru

    2017-11-01

    The novel titled compound 2-[(Anthracene-9-ylmethylene)amino]-2-methylpropane-1,3-diol (AMD) has been synthesized by slow evaporation technique from mixed solvent system of methanol with anthracene-9-carbaldehyde and 2-amino-2-methylpropane-1,3-diol. The synthesized molecule AMD was characterized experimentally by single crystal XRD, FTIR, NMR and UV-Vis spectra and density functional theory (DFT) computations. The structure of the crystal has been determined as orthorhombic system with space group P 21 21 21 and the cell parameters are obtained using XRD data. The optimized ground state geometry of the molecule is determined by evaluating torsional potentials as a function of angle of free rotation around Csbnd C bonds of functional groups by DFT method employing B3LYP functional with 6-311++G(d,p) basis set. All the fundamental vibrations of the molecule are assigned unambiguously using potential energy distribution (PED) obtained in the DFT computations. The rms error between the observed and scaled frequencies is 6.20 cm-1. The values of dipole moment, polarizability and hyperpolarizability are evaluated to study the NLO behavior of the molecule. The HOMO-LUMO energies and thermodynamic parameters are also determined. The molecular electrostatic surface potential (MESP) is mapped to obtain the charge density distribution. The 1H and 13C NMR chemical shifts of the molecule are calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. UV-visible spectrum of the compound is also recorded in the region 200-800 nm to know the type of electronic transitions involved. The anti-cancer activity of AMD is determined against human breast cancer cell line MCF-7 and human prostate cancer cell line PC-3 and correlated the results with study of molecular docking against pharmacological protein IDO-1 receptor.

  8. Computer-assisted structure elucidation from 13C-NMR-Spectra. I. The development of a three-dimensional structure code. II. The development of an isomer generating program

    International Nuclear Information System (INIS)

    Schuetz, V.

    1999-05-01

    The presented thesis consists of two separate programs which both aid the automated structure elucidation in the CSEARCH database system. A successful utilization of a large collection of NMR reference spectra for the prediction of chemical shift values is dependent on a strong correlation between the spectral data and the structural information via unique coding. By now, this was done using the two-dimensional HOSE code, which turned out to be insufficient whenever stereochemical effects other than cis/trans-isomerism contribute to the chemical shift values. Therefore, this new algorithm has been developed to derive the demanded three-dimensional descriptors. The calculation is performed by matching the query structures against pattern molecules taken from a carefully selected library of ring skeletons. No three-dimensional coordinates are necessary, since the algorithm elucidates the descriptors on base of two-dimensional structures having their stereocenters specified using 'up/down' bonds. The descriptors are defined as number of interactions over 3 to 5 bonds, number of cis-substituents over 1 to 2 ringbonds and markers for axial substituents. This approach of deriving descriptors for steric interactions has successfully extended the HOSE coding scheme and has been implemented into a neural network; both methods allow for high-quality prediction of 13 C-NMR chemical shift values. The second algorithm is an isomer generating program named GENERAL, which efficiently supports the structure elucidation process by calculating all mathematically possible structures to a given molecular formula. The resulting list of structures is exhaustive and free of redundancy. Besides the basic input information - like the molecular formula and the specification of structural fragments, constraints can be defined to restrict the number of resulting structures. The most valuable information is provided by state-of-the-art 2D-NMR experiments and can be easily incorporated into

  9. NMR study of hydride systems

    International Nuclear Information System (INIS)

    Peretz, M.

    1980-02-01

    The hydrides of thorium (ThH 2 , Th 4 H 15 and Th 4 D 15 ) and the intermetallic compound system (Zr(Vsub(1-x)Cosub(x)) 2 and its hydrides were investigated using the nuclear magnetic resonance (NMR) technique. From the results for the thorium hydride samples it was concluded that the density of states at the Fermi level n(Esub(f)) is higher in Th 4 H 15 than in ThH 2 ; there is an indirect reaction between the protons and the d electrons belonging to the Th atoms in Th 4 H 15 ; n(E) has a sharp structure near Esub(f). It was also found that the hydrogen diffusion mechanism changes with temperature. From the results for the intermetallic compound system conclusions were drawn concerning variations in the electronic structure, which explain the behavior of the system. In hydrogen diffusion studies in several samples it was found that Co atoms slow the diffusion rate. Quadrupole spectra obtained at low temperatures show that the H atoms preferably occupy tetrahedral sites formed by three V atoms and one Z atom. (H.K.)

  10. Baryon production in proton-proton collisions

    International Nuclear Information System (INIS)

    Liu, F.M.; Werner, K.

    2002-01-01

    Motivated by the recent rapidity spectra of baryons and antibaryons in pp collisions at 158 GeV and the Ω-bar/Ω ratio discussion, we reviewed string formation mechanism and some string models. This investigation told us how color strings are formed in ultrarelativistic proton-proton collisions

  11. Hydrogen cluster/network in tobermorite as studied by multiple-quantum spin counting {sup 1}H NMR

    Energy Technology Data Exchange (ETDEWEB)

    Mogami, Yuuki [Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Yamazaki, Satoru; Matsuno, Shinya [Analysis and Simulation Center, Asahi Kasei Corporation, Fuji, Shizuoka 416-8501 (Japan); Matsui, Kunio [Products and Marketing Development Dept., Asahi Kasei Construction Materials Corporation, Sakai-machi, Ibaraki 306-0493 (Japan); Noda, Yasuto [Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan); Takegoshi, K., E-mail: takeyan@kuchem.kyoto-u.ac.jp [Division of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8502 (Japan)

    2014-12-15

    Proton multiple-quantum (MQ) spin-counting experiment has been employed to study arrangement of hydrogen atoms in 9 Å/11 Å natural/synthetic tobermorites. Even though all tobermorite samples give similar characterless, broad static-powder {sup 1}H NMR spectra, their MQ spin-counting spectra are markedly different; higher quanta in 11 Å tobermorite do not grow with the MQ excitation time, while those in 9 Å one do. A statistical analysis of the MQ results recently proposed [26] is applied to show that hydrogens align in 9 Å tobermorite one dimensionally, while in 11 Å tobermorite they exist as a cluster of 5–8 hydrogen atoms.

  12. Thermal Fluctuations in the Magnetic Ground State of the Molecular Cluster Mn12O12 Acetate from μSR and Proton NMR Relaxation

    International Nuclear Information System (INIS)

    Lascialfari, A.; Borsa, F.; Carretta, P.; Jang, Z.H.; Borsa, F.; Gatteschi, D.

    1998-01-01

    Measurements of the spin-lattice relaxation rate are reported for muons and protons as a function of temperature for different values of the applied magnetic field in the Mn 12 O 12 molecular cluster. Strongly field dependent maxima in the relaxation rate versus temperature are observed below 50thinspthinspK. The results are explained in terms of thermal fluctuations of the total magnetization of the cluster among the different orientations with respect to the anisotropy axis. The lifetimes of the different m components of the total spin, S T =10 , of the molecule are obtained from the experiment and shown to be consistent with the ones expected from a spin-phonon coupling mechanism. No clear evidence for macroscopic quantum tunneling was observed in the field dependence of the proton relaxation rate at low T . copyright 1998 The American Physical Society

  13. Measurement of the energy spectra relative to neutrons produced at very small angle in $\\mathrm{\\sqrt{s} = 13 ~ TeV}$ proton-proton collisions using the LHCf Arm2 detector

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00533910

    In the last years, several ground-based experiments have measured flux and composition of ultra high energy cosmic rays - i.e. cosmic rays having energies above $10^{18} ~ eV$ - up to the GZK cutoff region. Nevertheless, these analyses suffer of large uncertainties due to the fact that they must rely on hadronic interaction models, that exhibit very different behavior in the forward region due to the lack of high energy calibration data. To provide measurements that can be useful to tune these models is exactly the main aim of the LHC-forward (LHCf) experiment. Thanks to two small sampling calorimeter, Arm1 and Arm2, installed at $\\pm 140 ~ m$ from LHC IP1, LHCf can detect neutral particles produced in the very forward region ($\\eta > 8.4$) by proton-proton and proton-ion high energy collisions (proton-proton interaction at $\\sqrt{s} = 14 ~ TeV$ is equivalent to the collision of a $10^{17} ~ eV$ proton with a proton at rest, hence it is possible to perform measurements at an energy close to the typical one of...

  14. Theoretical investigation on the molecular structure, Infrared, Raman and NMR spectra of para-halogen benzenesulfonamides, 4-X-C 6H 4SO 2NH 2 (X = Cl, Br or F)

    Science.gov (United States)

    Karabacak, Mehmet; Çınar, Mehmet; Çoruh, Ali; Kurt, Mustafa

    2009-02-01

    In the present study, the structural properties of para-halogen benzenesulfonamides, 4-XC 6H 4SO 2NH 2 (4-chlorobenzenesulfonamide (I), 4-bromobenzenesulfonamide (II) and 4-fluorobenzenesulfonamide (III)) have been studied extensively utilizing ab initio Hartree-Fock (HF) and density functional theory (DFT) employing B3LYP exchange correlation. The vibrational frequencies were calculated and scaled values were compared with experimental values. The complete assignments were performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method. The effects of the halogen substituent on the characteristic benzenesulfonamides bands in the spectra are discussed. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecules were calculated using the Gauge-Invariant Atomic Orbital (GIAO) method. Finally, geometric parameters, vibrational bands and chemical shifts were compared with available experimental data of the molecules. The fully optimized geometries of the molecules were found to be consistent with the X-ray crystal structures. The observed and calculated frequencies and chemical shifts were found to be in very good agreement.

  15. /sup 13/C, /sup 17/O, and /sup 33/S NMR spectra of alkyl phenyl sulfones C/sub 6/H/sub 5/SO/sub 2/Alk

    Energy Technology Data Exchange (ETDEWEB)

    Bzhezovskii, V.M.; Valeev, R.B.; Kalabin, G.A.; Aliev, I.A.

    1987-06-20

    The /sup 13/C, /sup 17/O, and /sup 33/S NMR spectra of alkyl phenyl sulfones C/sub 6/H/sub 5/SO/sub 2/Alk were obtained. The changes in the screening of the /sup 13/C, /sup 17/O, and /sup 33/S nuclei in these compounds are determined by the effect of the alkyl substituents, which alternates in sign and decreases along the chain of atoms in the order: CH/sub 3/, C/sub 2/H/sub 5/, iso-C/sub 3/H/sub 7/, and tert-C/sub 4/H/sub 9/. In the alkyl phenyl sulfides C/sub 6/H/sub 5/SAlk the additional effect of disruption in the p,..pi.. interaction between the sulfur atom and the benzene ring as a result of conformational changes is superimposed on the screening of the /sup 13/C/sup ortho/ nuclei. For the changes in the screening of the /sup 13/C/sup para/ nuclei in C/sub 6/H/sub 5/SAlk the steric disruption of the p,..pi.. conjugation by the alkyl substituents is determining.

  16. Proton NMR studies of Cucurbita maxima trypsin inhibitors: evidence for pH-dependent conformational change and His25-Tyr27 interaction.

    Science.gov (United States)

    Krishnamoorthi, R; Lin, C L; Gong, Y X; VanderVelde, D; Hahn, K

    1992-01-28

    A pH-dependent His25-Tyr27 interaction was demonstrated in the case of Cucurbita maxima trypsin inhibitors (CMTI-I and CMTI-III) by means of nuclear magnetic resonance (NMR) spectroscopy. pH titration, line widths, peak shapes, deuterium exchange kinetics, and two-dimensional nuclear Overhauser effect spectroscopy (NOESY) were employed to characterize a conformational change involving Tyr27, which was shown to be triggered by deprotonation of His25 around pH 6. A hydrogen bond is proposed to be formed between N epsilon of His25 and OH of Tyr27, as a distance between the atoms, His25 N epsilon and Tyr27 OH, of 3.02 A is consistent with a model built with NOE-derived distance constraints. Both the X-ray [Bode, W., Greyling, J.H., Huber, R., Otlewski, J., & Wilusz, T. (1989) FEBS Lett. 242, 282-292] and NMR [Holak, T.A., Gondol, D., Otlewski, J., & Wilusz, T. (1989) J. Mol. Biol. 210, 635-648] structures of CMTI-I at low pH (4.7-5.3) rule out such an interaction between the two aromatic rings, as the ring planes are oriented about 10 A away from each other. The presently characterized relative orientations of His25 and Tyr27 are of functional significance, as these residues make contact with the enzyme in the enzyme-inhibitor complex. Furthermore, trypsin assay and inhibitor-binding studies showed that conformations of trypsin and the squash inhibitor were functionally relevant only in the pH range 6-8. The pKa of His25 was determined and found to be influenced by Glu9/Lys substitution and by the hydrolysis of the reactive-site peptide bond between Arg5 and Ile6.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. NMR study of the molecular nanomagnet [Fe8(N3C6H15)6O2(OH)12]·[Br8·9H2O] in the high-spin magnetic ground state

    International Nuclear Information System (INIS)

    Furukawa, Y.; Kumagai, K.; Lascialfari, A.; Aldrovandi, S.; Borsa, F.; Sessoli, R.; Gatteschi, D.

    2001-01-01

    The magnetic molecular cluster [Fe 8 (N 3 C 6 H 15 ) 6 O 2 (OH) 12 ] 8+ [Br 8 ·9H 2 O] 8- , in short Fe8, has been investigated at low temperature by 1 H-NMR and relaxation measurements. Some measurements of 2 D-NMR in partially deuterated Fe8 clusters will also be reported. Upon decreasing temperature the NMR spectra display a very broad and structured signal which is the result of the internal local fields at the proton sites due to the local moments of the Fe(III) ions in the total S=10 magnetic ground state. The proton and deuteron NMR spectra have been analyzed and the different resonance peaks have been attributed to the different proton groups in the molecule. The simulation of the spectra by using a dipolar hyperfine field and the accepted model for the orientation of the Fe(III) local moments do not agree with the experiments even when the magnitude of the local Fe(III) moments is allowed to vary. It is concluded that a positive contact hyperfine interaction of the same order of magnitude as the dipolar interaction is present for all proton sites except the water molecules. The temperature and magnetic field dependence of the nuclear spin-lattice relaxation rate is ascribed to the fluctuations of the local Fe(III) moments, which follow rigidly the fluctuations of the total ground state magnetization of the nanomagnet. By using a simple model already utilized for the Mn12 cluster, we derive the value of the spin phonon coupling constant which determines the lifetime broadening of the different magnetic quantum number m substates of the S=10 ground state. It is shown that the lifetime broadening decreases rapidly on lowering the temperature. When the lifetime becomes longer than the reciprocal of the frequency shift of the proton lines a structure emerges in the NMR spectrum reflecting the ''frozen'' local moment configuration

  18. Novel determination of the total phenolic content in crude plant extracts by the use of 1H NMR of the -OH spectral region

    International Nuclear Information System (INIS)

    Nerantzaki, A.A.; Tsiafoulis, C.G.; Charisiadis, P.; Kontogianni, V.G.; Gerothanassis, I.P.

    2011-01-01

    A novel method for the determination of the total phenolic content using 1 H NMR spectroscopy in the -OH spectral region is presented. The use of DMSO-d 6 , which is an aprotic and strongly hydrogen bonding solvent, allows the 'appearance' of the relative sharp resonances of phenolic hydroxyl protons in the region of 8-14 ppm. The determination of the total phenolic -OH content requires three steps: (i) a 1D 1 H NMR spectrum is obtained in DMSO-d 6 ; (ii) a subsequent 1D 1 H NMR spectrum is recorded with irradiation of the residual water signal which results in the elimination or reduction of the phenolic -OH groups, due to proton exchange; and (iii) 1D 1 H NMR spectra are recorded with the addition of a progressively increased amount of salt, NaHCO 3 , which results in extensive linebroadening of the COOH resonances thus allowing the discrimination of the phenolic from the carboxylic acid signals. Integration, with respect to the internal standard TSP-d 4 , of the signal resonances between 14 and 8 ppm in spectrum (i) which are either eliminated or reduced in intensity in steps (ii) and (iii) allows the quantitation of the total phenolic content. The method was applied to model compounds, a mixture of them and several extracts of natural products. The results of the proposed 1 H NMR method were compared to the Folin-Ciocalteu (FC) reagent method. Additionally, since 1 H NMR refers to the total phenolic hydroxyl protons, a reaction factor, A e , is proposed that corresponds to the hydroxyl reactivity. The 1 H NMR method is rapid and accurate bearing the inherent advantages of the NMR spectroscopy and can be applied directly in complex extracts. Furthermore, it can be applied in a wide range of matrixes from crude plant extracts and food products to biological samples.

  19. Spectra of fast protons produced in the pA → pX reaction at the angle of 62 mrad

    International Nuclear Information System (INIS)

    Barabash, L.Z.; Buklej, A.E.; Gavrilov, V.B.

    1982-01-01

    Within the framework of a program of investigations into yields of secondary particles form internal targets of an accelerator obtained were experimetnal data on inclusive production of protons in pA interactions at 62 mradn angle at initial momenta of 4.0; 6.6; 9.5 GeV/c. The data obtained on differential cross sections of proton yields are tabulated. A- and t-dependences of quasi-elastic proton scattering with nuclei are discussed. A-dependence of cross sections of inelastic quasi-free reactions both in the region of isobar production and on the left of this region within the errors is the same as for quasi-elastic peak, α approximately 0.45. This α value is markedly less than a value characteristic of the A-dependence of total cross sections

  20. NMR Study on the Interaction of Trehalose with Lactose and Its Effect on the Hydrogen Bond Interaction in Lactose

    Directory of Open Access Journals (Sweden)

    Eric Morssing Vilén

    2013-08-01

    Full Text Available Trehalose, a well-known stress-protector of biomolecules, has been investigated for its effect on the mobility, hydration and hydrogen bond interaction of lactose using diffusion-ordered NMR spectroscopy and NMR of hydroxy protons. In ternary mixtures of trehalose, lactose and water, the two sugars have the same rate of diffusion. The chemical shifts, temperature coefficients, vicinal coupling constants and ROE of the hydroxy protons in trehalose, lactose and sucrose were measured for the disaccharides alone in water/acetone-d6 solutions as well as in mixtures. The data indicated that addition of trehalose did not change significantly the strength of the hydrogen bond interaction between GlcOH3 and GalO5' in lactose. Small upfield shifts were however measured for all hydroxy protons when the sugar concentration was increased. The chemical shift of the GlcOH3 signal in lactose showed less change, attributed to the spatial proximity to GalO5'. Chemical exchange between hydroxy protons of lactose and trehalose was observed in the ROESY NMR spectra. Similar effects were observed with sucrose indicating no specific effect of trehalose at the concentrations investigated (73 to 763 mg/mL and suggesting that it is the concentration of hydroxy groups more than the type of sugars which is guiding intermolecular interactions.

  1. Characterization of Silicon Nanocrystal Surfaces by Multidimensional Solid-State NMR Spectroscopy

    International Nuclear Information System (INIS)

    Hanrahan, Michael P.; Fought, Ellie L.; Windus, Theresa L.; Wheeler, Lance M.; Anderson, Nicholas C.

    2017-01-01

    The chemical and photophysical properties of silicon nanocrystals (Si NCs) are strongly dependent on the chemical composition and structure of their surfaces. Here we use fast magic angle spinning (MAS) and proton detection to enable the rapid acquisition of dipolar and scalar 2D 1 H– 29 Si heteronuclear correlation (HETCOR) solid-state NMR spectra and reveal a molecular picture of hydride-terminated and alkyl-functionalized surfaces of Si NCs produced in a nonthermal plasma. 2D 1 H– 29 Si HETCOR and dipolar 2D 1 H– 1 H multiple-quantum correlation spectra illustrate that resonances from surface mono-, di-, and trihydride groups cannot be resolved, contrary to previous literature assignments. Instead the 2D NMR spectra illustrate that there is large distribution of 1 H and 29 Si chemical shifts for the surface hydride species in both the as-synthesized and functionalized Si NCs. However, proton-detected 1 H– 29 Si refocused INEPT experiments can be used to unambiguously differentiate NMR signals from the different surface hydrides. Varying the 29 Si evolution time in refocused INEPT experiments and fitting the oscillation of the NMR signals allows for the relative populations of the different surface hydrides to be estimated. This analysis confirms that monohydride species are the predominant surface species on the as-synthesized Si NCs. A reduction in the populations of the di- and trihydrides is observed upon functionalization with alkyl groups, consistent with our previous hypothesis that the trihydride, or silyl (*SiH 3 ), group is primarily responsible for initiating surface functionalization reactions. Density functional theory (DFT) calculations were used to obtain quantum chemical structural models of the Si NC surface and reproduce the observed 1 H and 29 Si chemical shifts. Furthermore, the approaches outlined here will be useful to obtain a more detailed picture of surface structures for Si NCs and other hydride-passivated nanomaterials.

  2. Characterization of natural bentonite by NMR

    International Nuclear Information System (INIS)

    Leite, Sidnei Q.M.; Dieguez, Lidia C.; Menezes, Sonia M.C.; San Gil, Rosane A.S.

    1993-01-01

    Solid state NMR as well as several other instrumental chemical analysis techniques were used in order to characterize two natural occurring bentonite. The methodology is described. The NMR spectra, together with the other used techniques suggest that the observed differences are due to iron inclusions in tetrahedral and octahedral sites

  3. Broad line and pulsed NMR study of molecular motion in furfuryl alcohol resins

    International Nuclear Information System (INIS)

    Glowinkowski, S.; Pajak, Z.

    1978-01-01

    Broad line and pulsed nuclear magnetic resonance studies are carried out on a number of furfuryl alcohol resins differentiated by viscosity. Proton NMR spectra and relaxation times T 1 and Tsub(1rho) are measured over a wide temperature range and the results are interpreted in terms of molecular motion. The marked decrease in second moment and existence of high temperature spin-lattice relaxation times minima are presumed to result from rotational motion of polymer chains. The relaxation processes at low temperature are believed to be due to rotational motion of methyl endgroup and paramagnetic centres. (author)

  4. Proton NMR studies of Cucurbita maxima trypsin inhibitors: Evidence for pH-dependent conformational change and his25 - try27 interaction

    Energy Technology Data Exchange (ETDEWEB)

    Krishnamoorthi, R.; Chanlan Sun Lin; Yuxi Gong (Kansas State Univ., Manhattan (United States)); VanderVelde, D. (Univ. of Kansas, Lawrence (United States)); Hahn, K. (Univ. of Colorado, Denver (United States))

    1992-01-28

    A pH-dependent His25-Tyr27 interaction was demonstrated in the case of Cucurbita maxima trypsin inhibitors (CMTI-I and CMTI-III) by means of nuclear magnetic resonance (NMR) spectroscopy. pH titration, line widths, peak shapes, deuterium exchange kinetics, and two-dimensional nuclear Overhauser effect spectroscopy (NOESY) were employed to characterize a conformational change involving Tyr27, which was shown to be triggered by deprotonation of His25 around pH 6. A hydrogen bond is proposed to be formed between N{sub {epsilon}} of His25 and OH of Tyr27, as a distance between the atoms, His25 N{epsilon} and Tyr25 OH, of 3.02 {angstrom} is consistent with a model built with NOE-derived distance constraints. The presently characterized relative orientations of His25 and Tyr27 are of functional significance, as these residues make contact with the enzyme in the enzyme-inhibitor complex. Furthermore, trypsin assay and inhibitor-binding studies showed that conformations of trypsin and the squash inhibitor complex. Furthermore, trypsin assay and inhibitor-binding studies showed that conformations of trypsin and the squash inhibitor were functionally relevant only in the pH range 6-8. The pK{sub a} of His25 was determined and found to be influenced by Glu9/Lys substitution and by the hydrolysis of the reactive-site peptide bond between Arg5 and Ile6. As these sites are located far (>10 {angstrom}) from His25, the results point out conformational changes that are propagated to a distant site in the protein molecule.

  5. Bayesian Peak Picking for NMR Spectra

    KAUST Repository

    Cheng, Yichen; Gao, Xin; Liang, Faming

    2014-01-01

    Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic

  6. NMR study of rare earth and actinide complexes

    International Nuclear Information System (INIS)

    Villardi de Montlaur de, G.C.

    1978-01-01

    Proton magnetic resonance studies of lanthanide shift reagents with olefin-transition metal complexes, monoamines and diamines as substrates are described. Shift reagents for olefins are reported: Lnsup(III)(fod) 3 can induce substantial shifts in the nmr spectra of a variety of olefins when silver 1-heptafluororobutyrate is used to complex the olefin. The preparation, properties and efficiency of such systems are described. Configurational aspects and exchange processes of Lnsup(III)(fod) 3 complexes with secondary and tertiary monoamines are analysed by means of dynamic nmr. Factors influencing the stability and the stoichiometry of these complexes and various processes such as nitrogen inversion and ligand exchange are discussed. At low temperature, ring inversion can be slow on an nmr time-scale for Lnsup(III)(fod) 3 -diamino chelates. Barriers to ring inversion in substituted ethylenediamines and propanediamines are obtained. Steric factors appear to play an important role in the stability and kinetics of these bidentate species. The synthesis of uranium-IV crown-ether and cryptate complexes is described. A conformational study of these compounds show evidence of an insertion of the paramagnetic cation as witnessed by the large induced shifts observed. The insertion of uranium in the macrocyclic ligand of a UCl 4 -dicyclohexyl-18-crown-6 complex is confirmed by an X-ray structural determination [fr

  7. Efficient DNP NMR of Membrane Proteins: Sample Preparation Protocols, Sensitivity, and Radical Location

    Science.gov (United States)

    Liao, Shu Y.; Lee, Myungwoon; Wang, Tuo; Sergeyev, Ivan V.; Hong, Mei

    2016-01-01

    Although dynamic nuclear polarization (DNP) has dramatically enhanced solid-state NMR spectral sensitivities of many synthetic materials and some biological macromolecules, recent studies of membrane-protein DNP using exogenously doped paramagnetic radicals as polarizing agents have reported varied and sometimes surprisingly limited enhancement factors. This motivated us to carry out a systematic evaluation of sample preparation protocols for optimizing the sensitivity of DNP NMR spectra of membrane-bound peptides and proteins at cryogenic temperatures of ~110 K. We show that mixing the radical with the membrane by direct titration instead of centrifugation gives a significant boost to DNP enhancement. We quantify the relative sensitivity enhancement between AMUPol and TOTAPOL, two commonly used radicals, and between deuterated and protonated lipid membranes. AMUPol shows ~4 fold higher sensitivity enhancement than TOTAPOL, while deuterated lipid membrane does not give net higher sensitivity for the membrane peptides than protonated membrane. Overall, a ~100 fold enhancement between the microwave-on and microwave-off spectra can be achieved on lipid-rich membranes containing conformationally disordered peptides, and absolute sensitivity gains of 105–160 can be obtained between low-temperature DNP spectra and high-temperature non-DNP spectra. We also measured the paramagnetic relaxation enhancement of lipid signals by TOTAPOL and AMUPol, to determine the depths of these two radicals in the lipid bilayer. Our data indicate a bimodal distribution of both radicals, a surface-bound fraction and a membrane-bound fraction where the nitroxides lie at ~10 Å from the membrane surface. TOTAPOL appears to have a higher membrane-embedded fraction than AMUPol. These results should be useful for membrane-protein solid-state NMR studies under DNP conditions and provide insights into how biradicals interact with phospholipid membranes. PMID:26873390

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

    International Nuclear Information System (INIS)

    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, β/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 β. 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 1 H with 2 H combined with magic angle rotation. The resolution obtained represents the practical limit for proton NMR of solids

  9. Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Shu Y.; Lee, Myungwoon; Wang, Tuo [Massachusetts Institute of Technology, Department of Chemistry (United States); Sergeyev, Ivan V. [Bruker Biospin (United States); Hong, Mei, E-mail: meihong@mit.edu [Massachusetts Institute of Technology, Department of Chemistry (United States)

    2016-03-15

    Although dynamic nuclear polarization (DNP) has dramatically enhanced solid-state NMR spectral sensitivities of many synthetic materials and some biological macromolecules, recent studies of membrane-protein DNP using exogenously doped paramagnetic radicals as polarizing agents have reported varied and sometimes surprisingly limited enhancement factors. This motivated us to carry out a systematic evaluation of sample preparation protocols for optimizing the sensitivity of DNP NMR spectra of membrane-bound peptides and proteins at cryogenic temperatures of ~110 K. We show that mixing the radical with the membrane by direct titration instead of centrifugation gives a significant boost to DNP enhancement. We quantify the relative sensitivity enhancement between AMUPol and TOTAPOL, two commonly used radicals, and between deuterated and protonated lipid membranes. AMUPol shows ~fourfold higher sensitivity enhancement than TOTAPOL, while deuterated lipid membrane does not give net higher sensitivity for the membrane peptides than protonated membrane. Overall, a ~100 fold enhancement between the microwave-on and microwave-off spectra can be achieved on lipid-rich membranes containing conformationally disordered peptides, and absolute sensitivity gains of 105–160 can be obtained between low-temperature DNP spectra and high-temperature non-DNP spectra. We also measured the paramagnetic relaxation enhancement of lipid signals by TOTAPOL and AMUPol, to determine the depths of these two radicals in the lipid bilayer. Our data indicate a bimodal distribution of both radicals, a surface-bound fraction and a membrane-bound fraction where the nitroxides lie at ~10 Å from the membrane surface. TOTAPOL appears to have a higher membrane-embedded fraction than AMUPol. These results should be useful for membrane-protein solid-state NMR studies under DNP conditions and provide insights into how biradicals interact with phospholipid membranes.

  10. Proton conduction in biopolymer exopolysaccharide succinoglycan

    Energy Technology Data Exchange (ETDEWEB)

    Kweon, Jin Jung [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of); National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States); Lee, Kyu Won; Kim, Hyojung; Lee, Cheol Eui, E-mail: rscel@korea.ac.kr [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of); Jung, Seunho [Department of Bioscience and Biotechnology and UBITA, Konkuk University, Seoul 143-701 (Korea, Republic of); Kwon, Chanho [Naraebio Research Laboratories, 177 Dangha-ri, Bongdam-eup, Hawseong-si 445-892 (Korea, Republic of)

    2014-07-07

    Protonic currents play a vital role in electrical signalling in living systems. It has been suggested that succinoglycan plays a specific role in alfalfa root nodule development, presumably acting as the signaling molecules. In this regard, charge transport and proton dynamics in the biopolymer exopolysaccharide succinoglycan have been studied by means of electrical measurements and nuclear magnetic resonance (NMR) spectroscopy. In particular, a dielectric dispersion in the system has revealed that the electrical conduction is protonic rather electronic. Besides, our laboratory- and rotating-frame {sup 1}H NMR measurements have elucidated the nature of the protonic conduction, activation of the protonic motion being associated with a glass transition.

  11. Polymeric proanthocyanidins 13C NMR studies of procyanidins

    Science.gov (United States)

    Lawrence J. Porter; Roger H. Newman; Lai Yeap Foo; Herbert Wong; Richard W. Hemingway

    1982-01-01

    Proanthocyanidin polymers have been shown to consist entirely of flavan-3-ol units by a combination of techniques including 13C n.m.r. spectroscopy. The 13C n.m.r. spectra of the polymers and related molecules are now considered in more detail. Prior to this study UC n.m.r. data has been published of procyanidins and...

  12. Two dimensional solid state NMR

    International Nuclear Information System (INIS)

    Kentgens, A.P.M.

    1987-01-01

    This thesis illustrates, by discussing some existing and newly developed 2D solid state experiments, that two-dimensional NMR of solids is a useful and important extension of NMR techniques. Chapter 1 gives an overview of spin interactions and averaging techniques important in solid state NMR. As 2D NMR is already an established technique in solutions, only the basics of two dimensional NMR are presented in chapter 2, with an emphasis on the aspects important for solid spectra. The following chapters discuss the theoretical background and applications of specific 2D solid state experiments. An application of 2D-J resolved NMR, analogous to J-resolved spectroscopy in solutions, to natural rubber is given in chapter 3. In chapter 4 the anisotropic chemical shift is mapped out against the heteronuclear dipolar interaction to obtain information about the orientation of the shielding tensor in poly-(oxymethylene). Chapter 5 concentrates on the study of super-slow molecular motions in polymers using a variant of the 2D exchange experiment developed by us. Finally chapter 6 discusses a new experiment, 2D nutation NMR, which makes it possible to study the quadrupole interaction of half-integer spins. 230 refs.; 48 figs.; 8 tabs

  13. Effect of resonance production and diffraction on the inclusive spectra of pions and protons in 19 GeV/c pn interactions

    Energy Technology Data Exchange (ETDEWEB)

    Baken, V.; Breivik, F.O.; Jacobsen, T. (Oslo Univ. (Norway). Fysisk Inst.)

    1984-01-01

    Bubble chamber data on pn interactions at 19 GeV/c are used to investigate the effects of nucleon diffraction and resonance production on the inclusive x- and psub(T)/sup 2/-distributions of protons and pions. We determine the differential distributions of p, ..pi../sup -/ and ..pi../sup +/ due to neutron and proton diffraction and similarly the distributions from the decay of the strong resonances ..delta../sup + +/(1232) and ..delta../sup -/(1232) and from rho/sup 0/(770). The x-distributions of the protons in the two c.m. hemispheres become quite similar when the effect of diffraction and ..delta../sup + +/ is subtracted. The psub(T)/sup 2/-distributions can then be described by a single exponential in the whole kinematic region. The net effect on the shapes of the x-distributions of the pions due to diffraction, ..delta../sup + +//..delta../sup -/ and rho/sup 0/ production is rather small. The separate effects of these processes on the particle ratio ..pi../sup -//..pi../sup +/ is investigated. By excluding the diffraction and ..delta../sup + +//..delta../sup -/ production, the strength of the low-psub(T)/sup 2/ component of the psub(T)/sup 2/-distributions of the pions is reduced, but it seems that diffraction and resonance production cannot account for all of this low-psub(T)/sup 2/ enhancement.

  14. Protonation of pyridine. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Zahran, N F; Ghoniem, H; Helal, A I [Physics Dept., Nuclear Research Center, AEA., Cairo, (Egypt); Rasheed, N [Nuclear Material Authority, Cairo, (Egypt)

    1996-03-01

    Field ionization mass spectra of pyridine is measured using 10{mu}m activated wire. protonation of pyridine, is observed as an intense peak in the mass spectra. Charge distribution of pyridine molecule is calculated using the modified neglect of diatomic overlap (MNDO) technique, and consequently proton attachment is proposed to be on the nitrogen atom. Temperature dependence of (M+H){sup +} ion is investigated and discussed. MNDO calculations of the protonated species are done, and the proton affinity of pyridine molecule is estimated. Time dependence of the field ionization process of pyridine and protonated ions are observed and discussed. 5 figs.

  15. High resolution NMR spectroscopy of synthetic polymers in bulk

    International Nuclear Information System (INIS)

    Komorski, R.A.

    1986-01-01

    The contents of this book are: Overview of high-resolution NMR of solid polymers; High-resolution NMR of glassy amorphous polymers; Carbon-13 solid-state NMR of semicrystalline polymers; Conformational analysis of polymers of solid-state NMR; High-resolution NMR studies of oriented polymers; High-resolution solid-state NMR of protons in polymers; and Deuterium NMR of solid polymers. This work brings together the various approaches for high-resolution NMR studies of bulk polymers into one volume. Heavy emphasis is, of course, given to 13C NMR studies both above and below Tg. Standard high-power pulse and wide-line techniques are not covered

  16. NMR spectroscopy using liquid crystal solvents

    CERN Document Server

    Emsley, JW

    2013-01-01

    NMR Spectroscopy using Liquid Crystal Solvents covers the importance of using a liquid crystal solvent in NMR to derive nuclear dipolar spin-spin coupling constants. This book is composed of ten chapters, and begins with a brief description of the features and benefits of liquid crystal in NMR spectroscopic analysis. The succeeding chapters deal with the mode of operation of nuclear spin Hamiltonian for partially oriented molecules and the analysis of NMR spectra of partially oriented molecules, as well as the determination of rigid molecule structure. These topics are followed by discussions

  17. HPLC-NMR revisited: Using time-slice HPLC-SPE-NMR with database assisted dereplication

    DEFF Research Database (Denmark)

    Johansen, Kenneth; Wubshet, Sileshi Gizachew; Nyberg, Nils

    2013-01-01

    Time based trapping of chromatographically separated compounds on to solid-phase extraction cartridges (SPE) and subsequent elution to NMR-tubes was done to emulate the function of HPLC–NMR for dereplication purposes. Sufficient mass sensitivity was obtained by the use of a state-of-the-art HPLC......–SPE–NMR-system with a cryogenically cooled probe head, designed for 1.7 mm NMR-tubes. The resulting 1H NMR spectra (600 MHz) were evaluated against a database of previously acquired and prepared spectra. The in-house developed matching algorithm, based on partitioning of the spectra and allowing for changes in the chemical shifts......, is described and the code included as Supplementary Information. Two mixtures of natural products was used to test the approach; one extract of Carthamus oxyacantha (wild safflower) containing an array of spiro compounds and one extract of the endophytic fungus Penicillum namyslowski containing griseofulvin...

  18. NMR in clinical practice

    International Nuclear Information System (INIS)

    Smith, F.W.

    1987-01-01

    The development of NMR for clinical use has been complicated by a number of controversies, the largest of these being the question of what is the optimum field strength for proton imaging. Many workers believe that diagnostically useful images can only be produced at high field strength (i.e. 0.5 - 2.0 T), where in fact diagnostically useful images are made using field strengths of as low as 0.02 T. Because the method is more complex than X-ray CT, which relies on the measurement of only one parameter, tissue density, many new users have difficulty in selecting the correct imaging pulse sequence to provide the most useful image for diagnosis. NMR imaging pulse sequence may be selected to produce images of the proton density, T/sub 1/ or T/sub 2/ signals, or combinations of them. When this facility is used, images which are T/sub 1/ or T/sub 2/ weighted can be selected. Inversion-recovery sequences are more appropriate for imaging the abdomen where by selecting a short TR interval the signal from subcutaneous fat, which is the major cause of image artefact in abdominal imaging, is suppressed thereby improving image quality. The use of surface receiver coils, which are applied closely to the area of the body being examined is becoming more widespread and is of particular value when examining the orbits, facial structures, neck, breast, spine and limbs. The use of these coils together with a discussion of patient selection for NMR imaging, image interpretation and data storage follow

  19. Measurements of $$\\pi ^\\pm $$ π ± , K $$^\\pm $$ ± , p and $${\\bar{\\text {p}}}$$ p ¯ spectra in proton-proton interactions at 20, 31, 40, 80 and 158  $$\\text{ GeV }/c$$ GeV / c with the NA61/SHINE spectrometer at the CERN SPS: The NA61/SHINE Collaboration

    Energy Technology Data Exchange (ETDEWEB)

    Aduszkiewicz, A.; Ali, Y.; Andronov, E.; Antićić, T.; Baatar, B.; Baszczyk, M.; Bhosale, S.; Blondel, A.; Bogomilov, M.; Brandin, A.; Bravar, A.; Brzychczyk, J.; Bunyatov, S. A.; Busygina, O.; Cherif, H.; Ćirković, M.; Czopowicz, T.; Damyanova, A.; Davis, N.; Dembinski, H.; Deveaux, M.; Dominik, W.; Dorosz, P.; Dumarchez, J.; Engel, R.; Ereditato, A.; Feofilov, G. A.; Fodor, Z.; Francois, C.; Garibov, A.; Gaździcki, M.; Golubeva, M.; Grebieszkow, K.; Guber, F.; Haesler, A.; Hervé, A. E.; Hylen, J.; Igolkin, S.; Ivashkin, A.; Johnson, S. R.; Kadija, K.; Kaptur, E.; Kiełbowicz, M.; Kireyeu, V. A.; Klochkov, V.; Knezević, N.; Kolesnikov, V. I.; Kolev, D.; Kondratiev, V. P.; Korzenev, A.; Kovalenko, V.; Kowalik, K.; Kowalski, S.; Koziel, M.; Krasnoperov, A.; Kucewicz, W.; Kuich, M.; Kurepin, A.; Larsen, D.; László, A.; Lewicki, M.; Lundberg, B.; Lyubushkin, V. V.; Łysakowski, B.; Maćkowiak-Pawłowska, M.; Maksiak, B.; Malakhov, A. I.; Manić, D.; Marchionni, A.; Marcinek, A.; Marino, A. D.; Marton, K.; Mathes, H. -J.; Matulewicz, T.; Matveev, V.; Melkumov, G. L.; Merzlaya, A.; Messerly, B.; Mik, Ł.; Mills, G. B.; Morozov, S.; Mrówczyński, S.; Nagai, Y.; Naskręt, M.; Ozvenchuk, V.; Paolone, V.; Pavin, M.; Petukhov, O.; Pistillo, C.; Płaneta, R.; Podlaski, P.; Popov, B. A.; Posiadała, M.; Puławski, S.; Puzović, J.; Rameika, R.; Rauch, W.; Ravonel, M.; Renfordt, R.; Richter-Wąs, E.; Röhrich, D.; Rondio, E.; Roth, M.; Rumberger, B. T.; Rustamov, A.; Rybczynski, M.; Rybicki, A.; Sadovsky, A.; Schmidt, K.; Selyuzhenkov, I.; Seryakov, A.; Seyboth, P.; Słodkowski, M.; Snoch, A.; Staszel, P.; Stefanek, G.; Stepaniak, J.; Strikhanov, M.; Ströbele, H.; Šuša, T.; Szuba, M.; Taranenko, A.; Tefelska, A.; Tefelski, D.; Tereshchenko, V.; Toia, A.; Tsenov, R.; Turko, L.; Ulrich, R.; Unger, M.; Veberič, D.; Vechernin, V. V.; Vesztergombi, G.; Vinogradov, L.; Walewski, M.; Wickremasinghe, A.; Wilkinson, C.; Włodarczyk, Z.; Wojtaszek-Szwarc, A.; Wyszyński, O.; Zambelli, L.; Zimmerman, E. D.; Zwaska, R.

    2017-10-01

    Measurements of inclusive spectra and mean multiplicities of $\\pi^\\pm$, K$^\\pm$, p and $\\bar{\\textrm{p}}$ produced in inelastic p+p interactions at incident projectile momenta of 20, 31, 40, 80 and 158 GeV/c ($\\sqrt{s} = $ 6.3, 7.7, 8.8, 12.3 and 17.3 GeV, respectively) were performed at the CERN Super Proton Synchrotron using the large acceptance NA61/SHINE hadron spectrometer. Spectra are presented as function of rapidity and transverse momentum and are compared to predictions of current models. The measurements serve as the baseline in the NA61/SHINE study of the properties of the onset of deconfinement and search for the critical point of strongly interacting matter.

  20. NMR investigations of the melting behaviour of mesogen compounds

    International Nuclear Information System (INIS)

    Limmer, S.; Grande, S.; Loesche, A.

    1977-01-01

    Proton NMR spectra of mesogen compounds in the solid phase are recorded. Between 20 and 40 K and 4 and 12 K below the melting point they exhibit a very narrow central line with a structure caused by the chemical shift, which is superimposed to the broad structureless line normally expected from polycrystalline solid phases. It is concluded that it originates from ''quasi-liquid'' molecules whose intensity grows drastically with increasing temperature and involves a maximum of about 2.5% of the whole intensity of the spectrum. In the region close to the melting point appears another lineshape, the so-called ''super-Lorentzian'' line, whose intensity increases still stronger than that of the narrow line. It can be shown that it is due to the existence of mesomorphic clusters the directors of which are statistically distributed in the sample. The impurity dependence of these effects is investigated and an attempt is made to explain them. (author)

  1. Carbon-13 NMR of flavinoids

    International Nuclear Information System (INIS)

    Agrawal, P.K.

    1989-01-01

    The present book has been written with the objective of introducing the organic chemists with the conceptual and experimental basis required for interpretation of 13 C NMR spectra of a flavonoid and to a discussion of general usefulness of the technique in solving flavonoid structural problem. After a brief general introduction to the essential aspects of flavonoids and 13 C NMR spectroscopy, considerable emphasis has been placed in chapter 2 on the various experimental methods and the interpretation of spectral details which enable individual resonance lines to be associated with the appropriate carbons in a molecule. The whole bulk of the literature, published on 13 C NMR of flavonoids in the major journals upto 1986 alongwith some recent references of 1987 has been classified in several categories such as: flavonoids, isflavonoids, other flavonoids, flavonoid glycosides, chalconoids and flavanoids. Each category constitutes a chapter. Finally the last chapter is devoted largely to a discussion for the differentiation of various categories and subcategories of flavonoids and for the establishment of aromatic substitution pattern in these compounds. It should be emphasized that the book is a data book and only concerned with the actual analysis of 13 C NMR spectra, thus a reasonable familiarity with basic instrumentation of 13 C NMR and general pattern of nuclear chemical shifts has been assumed. (author). refs.; figs.; tabs

  2. NMR imaging of cerebral infarction

    International Nuclear Information System (INIS)

    Takusagawa, Yoshihiko; Yamaoka, Naoki; Doi, Kazuaki; Okada, Keisei

    1987-01-01

    One hundred and five patients with cerebral infarction were studied by nuclear magnetic resonance (NMR) CT (resistive type of magnet with strength of 0.1 tesla) and X-ray CT. Pulse sequences used saturation recovery (Tr = 600 mSec), Inversion recovery (Tr = 500 mSec, Td = 300 mSec) and spin echo (Tr = 1500 mSec, Te = 40, 80, 120, 160 mSec). Fifteen cases were examined by NMR-CT within 24 hours from onset. Proton NMR imaging could not detect cerebral ischemia as early as 2 hours after onset, but except could detect the lesions in Se image the area of cerebral infarct 3 hours after onset. After 5 hours from onset image changes in SE were evident and corresponded to the area of cerebral infarct, but image changes in IR could not fully delineate the infarcted area. NMR images of 41 year-old woman with cerebral embolism by MCA trunck occlusion associated with mitral stenosis were presented, and NMR-CT was examined 10 hours, 9th and 43th days after episode of MCA occlusion. Sixty patents (64 times) with lacunar infarction were studied by NMR-CT and X-ray CT. The inversion recovery images were used mainly for detection of lesions and comparison with X-ray CT. In 160 lesions which were detected by NMR-CT or X-ray CT, could 156 lesions be detected by NMR-CT and 78 lesions by X-ray CT. Inversion recovery images were more useful for detection of lacunes than X-ray CT. Calculated T1 and T2 values prolonged with time course from onset. (author)

  3. NMR investigation of coal extracts

    Energy Technology Data Exchange (ETDEWEB)

    Lang, I; Sebor, G [Ceskoslovenska Akademie Ved, Prague. Hornicky Ustav; Sebor, G Jr; Hajek, M; Mostecky, J [Vysoka Skola Chemicko-Technologicka, Prague (Czechoslovakia)

    1978-07-01

    Proton NMR spectroscopy was used for the evaluation of 10% coal extract solutions in deuterated pyridine. Four types of Czechoslovak coal were analyzed. Agreement was found between the aromaticity of coal extracts calculated from /sup 1/H NMR data using Brown's method and Ladner's and Williams' method and the characterization of an average molecule of the coal extract by the number of non-bridge carbon atoms of aromatic rings, by the overall number of aromatic ring carbon atoms and the number of aromatic rings, determined by the Williams and Ferris methods. The methods for calculating carbon distribution from /sup 1/H NMR data, however, contain some constants theoretically estimated or experimentally found using the method which still remain to be verified.

  4. Metal alkyls programmed to generate metal alkylidenes by α-H abstraction: prognosis from NMR chemical shift† †Electronic supplementary information (ESI) available: Experimental and computational details, NMR spectra, results of NMR calculations and NCS analysis, graphical representation of shielding tensors, molecular orbital diagrams of selected compounds, optimized structures for all calculated species. See DOI: 10.1039/c7sc05039a

    Science.gov (United States)

    Gordon, Christopher P.; Yamamoto, Keishi; Searles, Keith; Shirase, Satoru

    2018-01-01

    Metal alkylidenes, which are key organometallic intermediates in reactions such as olefination or alkene and alkane metathesis, are typically generated from metal dialkyl compounds [M](CH2R)2 that show distinctively deshielded chemical shifts for their α-carbons. Experimental solid-state NMR measurements combined with DFT/ZORA calculations and a chemical shift tensor analysis reveal that this remarkable deshielding originates from an empty metal d-orbital oriented in the M–Cα–Cα′ plane, interacting with the Cα p-orbital lying in the same plane. This π-type interaction inscribes some alkylidene character into Cα that favors alkylidene generation via α-H abstraction. The extent of the deshielding and the anisotropy of the alkyl chemical shift tensors distinguishes [M](CH2R)2 compounds that form alkylidenes from those that do not, relating the reactivity to molecular orbitals of the respective molecules. The α-carbon chemical shifts and tensor orientations thus predict the reactivity of metal alkyl compounds towards alkylidene generation. PMID:29675237

  5. The effect of resonance production and diffraction on the inclusive spectra of pions and protons in 19 GeV/c pn interactions

    International Nuclear Information System (INIS)

    Bakken, V.; Breivik, F.O.; Jacobsen, T.

    1984-01-01

    Bubble chamber data on pn interactions at 19 GeV/c are used to investigate the effects of nucleon diffraction and resonance production on the inclusive x- and psub(T)sup(2)-distributions of protons and pions. The differential distributions of p, π - and distributions from the decay of the strong resonances Δsup(++)(1232) and Δ - (1232) and from rho 0 (770) are determined. The x-distributions of the protons in the two c.m. hemispheres become quite similar when the effect of diffraction and Δsup(++) is subtracted. The psub(T)sup(2)-distributions can then be described by a single exponential in the whole kinematic region. The net effect on the shape of the x-distributions of the pions due to diffraction, effect of these processes on the particle ratio π - /π + is investigated. By excluding the diffraction and Δsup(++)/Δ - production, the strength of the low-psub(T)sup(2) component of the psub(T)sup(2)-distributions of the pions is reduced, but it seems that diffraction and resonance production cannot account for all oft his low-psub(T)sup(2) enhancement

  6. Measurements of neutron spectra produced from a thick tungsten target bombarded with 0.5- and 1.5-GeV protons

    International Nuclear Information System (INIS)

    Meigo, Shin-ichiro; Takada, Hiroshi

    2002-01-01

    For validation of calculation codes that are employed in the design of pulse spallation neutron source and accelerator driven system, spectrum of neutrons produced from a thick target plays an important role. However, appropriate experimental data were scarce for the incident energies higher than 0.8 GeV. In this study, the spectrum from a thick tungsten target was measured. The experiment was carried out at the π2 beam line of the 12-GeV proton synchrotron at KEK. The tungsten target was bombarded by the 0.5- and 1.5-GeV secondary protons. Spectrum of neutrons was measured by the time-of-flight technique using organic scintillators of NE213. The calculated result with NMTC/JAM and MCNP-4A is compared with the measured data. It is found that the NMTC/JAM generally gives a good agreement with experiment. The NMTC/JAM, however, gives 50% lower neutron flux in the energy region 20∼80 MeV, which is consistent with the results in previous comparison of lead target. For the neutrons between 20 and 80 MeV, the calculation using with the in-medium nucleon-nucleon cross sections reproduced the experiment fairly well. (author)

  7. Proton and electron impact on molecular and atomic oxygen: I. High resolution fluorescence spectra in the visible and VUV spectral range and emission cross-sections for dissociative ionisation and excitation of O2

    International Nuclear Information System (INIS)

    Wilhelmi, O.; Schartner, K.H.

    2000-01-01

    For pt.II see ibid., vol.11, p.45-58, 2000. Molecular oxygen O 2 was dissociated in collisions with protons and electrons in the intermediate velocity range (p + -energies: 17-800 keV, e - -energies: 0.2-2 keV). Fluorescence from excited atomic and singly ionised fragments and from singly ionised molecules was detected in the VUV and in the visible and near UV spectral range. Highly resolved spectra are presented for the VUV (46-131 nm) and the near UV/visible (340-605 nm) spectral range. Absolute emission cross-sections have been determined for dissociative ionisation and excitation leading to fluorescence in the VUV. Results are compared with published data. (orig.)

  8. Proton-proton bremsstrahlung

    International Nuclear Information System (INIS)

    Fearing, H.W.

    1990-01-01

    We summarize some of the information about the nucleon-nucleon force which has been obtained by comparing recent calculations of proton-proton bremsstrahlung with cross section and analyzing power data from the new TRIUMF bremsstrahlung experiment. Some comments are made as to how these results can be extended to neutron-proton bremsstrahlung. (Author) 17 refs., 6 figs

  9. Two-dimensional NMR spectrometry

    International Nuclear Information System (INIS)

    Farrar, T.C.

    1987-01-01

    This article is the second in a two-part series. In part one (ANALYTICAL CHEMISTRY, May 15) the authors discussed one-dimensional nuclear magnetic resonance (NMR) spectra and some relatively advanced nuclear spin gymnastics experiments that provide a capability for selective sensitivity enhancements. In this article and overview and some applications of two-dimensional NMR experiments are presented. These powerful experiments are important complements to the one-dimensional experiments. As in the more sophisticated one-dimensional experiments, the two-dimensional experiments involve three distinct time periods: a preparation period, t 0 ; an evolution period, t 1 ; and a detection period, t 2

  10. Solid state NMR of materials

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Sharon A; Ferguson, David B; Haw, James F [Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry

    1994-12-31

    In situ NMR experiments are studied, including probe of several structures such as the structures of the organic adsorbates, Broensted acid sites, other nuclei associated with active sites, and other framework sites. The authors report that in the absence of high concentrations of paramagnetic sites or metal particles, high resolution MAS spectra are relatively easy to obtain and interpret. It is also concluded that NMR can measure spatial distributions and rates of diffusion; and are able to characterize equilibrium structures and the frequencies and amplitudes of molecular motion

  11. Two-dimensional NMR investigations of the dynamic conformations of phospholipids and liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Mei [Univ. of California, Berkeley, CA (United States). Applied Science and Technology

    1996-05-01

    Two-dimensional 13C, 1H, and 31P nuclear magnetic resonance (NMR) techniques are developed and used to study molecular structure and dynamics in liquid-crystalline systems, primarily phospholipids and nematic liquid crystals. NMR spectroscopy characterizes molecular conformation in terms of orientations and distances of molecular segments. In anisotropically mobile systems, this is achieved by measuring motionally-averaged nuclear dipolar couplings and chemical shift anisotropies. The short-range couplings yield useful bond order parameters, while the long-range interactions constrain the overall conformation. In this work, techniques for probing proton dipolar local fields are further developed to obtain highlyresolved dipolar couplings between protons and rare spins. By exploiting variable-angle sample spinning techniques, orientation-sensitive NMR spectra are resolved according to sitespecific isotropic chemical shifts. Moreover, the signs and magnitudes of various short-range dipolar couplings are obtained. They are used in novel theoretical analyses that provide information about segmental orientations and their distributions. Such information is obtained in a model-independent fashion or with physically reasonable assumptions. The structural investigation of phospholipids is focused on the dynam

  12. NMR imaging

    International Nuclear Information System (INIS)

    Ouchi, Toshihiro; Steiner, R.E.

    1984-01-01

    Three epidermoid and two dermoid tumours, pathologically proven, were examined by NMR and CT scans. Although most brain tumours have a low signal with a long T 1 , a dermoid cyst and one of the two components of the other dermoid tumour had a high signal and therefore a short T 1 . All three epidermoid tumours had a low signal and a long T 1 . Because of the high level contrast between some of the tumours and cerebrospinal fluid, NMR is helpful to detect the lesion. Neither of the liquid fluid levels in the tumour cysts or floating fat in the subarachnoid space was recognized in one patients, but the fine leakage of the content from the epidermoid cyst into the lateral ventricle was detected on a saturation recovery 1000 image in one case. (author)

  13. Proton, deuteron, and triton emission at target rapidity in Au+Au collisions at 10.20A GeV: Spectra and directed flow

    International Nuclear Information System (INIS)

    Ashktorab, K.; Beavis, D.; Chasman, C.; Chen, Z.; Chu, Y.Y.; Cumming, J.B.; Debbe, R.; Gonin, M.; Gushue, S.; Levine, M.; Moskowitz, B.; Olness, J.; Remsberg, L.P.; Tannenbaum, M.J.; Videbaek, F.; Zhu, F.; Crawford, H.J.; Engelage, J.; Judd, E.; Chang, J.; Eldredge, W.; Fung, S.Y.; Seto, R.; Xu, G.; Zhu, Q.; Chi, C.; Cole, B.A.; Moulson, M.; Nagamiya, S.; Nayak, T.K.; Wang, F.Q.; Wang, Y.; Wu, Y.; Zajc, W.A.; Akiba, Y.; Hamagaki, H.; Homma, S.; Sako, H.; Kaneko, H.; Britt, H.C.; Cianciolo, V.; Luke, J.; Namboodiri, M.N.; Sangster, T.C.; Soltz, R.; Thomas, J.H.; Tonse, S.R.; Ahle, L.; Baker, M.D.; Heintzelman, G.; Ogilvie, C.A.; Steadman, S.G.; Stephans, G.S.; Sung, T.; Woodruff, D.S.; Zachary, D.; Hayano, R.S.; Shigaki, K.; Kumagai, A.; Kurita, K.; Miake, Y.; Ueno-Hayashi, S.; Yagi, K.; Kang, J.H.; Gaardhoje, J.J.; Hansen, A.G.; Hansen, L.

    1998-01-01

    Systematic results are presented on proton, deuteron, and triton emission from the target spectator region in collisions of 10.20A GeV gold projectiles with a gold target. A forward hodoscope utilizes detection of projectile spectator fragments to determine the orientation of the reaction plane, event by event. The directed flow left-angle p x right-angle is determined as a function of pseudorapidity. Projectile spectator energy is used to estimate impact parameters. Results are compared to current theoretical models ARC, ART, and RQMD. In all cases good agreement with theory is obtained for calculations utilizing a pure cascade without nuclear potential contributions. copyright 1998 The American Physical Society

  14. NMR studies of abasic sites in DNA duplexes: Deoxyadenosine stacks into the helix opposite acyclic lesions

    International Nuclear Information System (INIS)

    Kalnik, M.W.; Chang, Chienneng; Johnson, F.; Grollman, A.P.; Patel, D.J.

    1989-01-01

    Proton and phosphorus NMR studies are reported for two complementary nonanucleotide duplexes containing acyclic abasic sites. The first duplex, d(C-A-T-G-A-G-T-A-C)·d(G-T-A-C-P-C-A-T-G), contains an acyclic propanyl moiety, P, located opposite a deoxyadenosine at the center of the helix (designated AP P 9-mer duplex). The second duplex, d(C-A-T-G-A-G-T-A-C-)·d(G-T-A-C-E-C-A-T-G), contains a similarly located acyclic ethanyl moiety, E (designated AP E 9-mer duplex). The ethanyl moiety is one carbon shorter than the natural carbon-phosphodiester backbone of a single nucleotide unit of DNA. The majority of the exchangeable and nonexchangeable base and sugar protons in both the AP P 9-mer and AP E 9-mer duplexes, including those at the abasic site, have been assigned by recording and analyzing two-dimensional phase-sensitive NOESY data sets in H 2 O and D 2 O solution between -5 and 5 degree C. These spectroscopic observations establish that A5 inserts into the helix opposite the abasic site (P14 and El14) and stacks between the flanking G4·C15 and G6·C13 Watson-Crick base pairs in both the AP P 9-mer and AP E 9-mer duplexes. Proton NMR parameters for the Ap P 9-mer and AP E 9-mer duplexes are similar to those reported previously. These proton NMR experiments demonstrate that the structures at abasic sites are very similar whether the five-membered ring is open or closed or whether the phosphodiester backbone is shortened by one carbon atom. Phosphorus spectra of the AP P 9-mer and AP E 9-mer duplexes (5 degree C) indicate that the backbone conformation is similarly perturbed at three phosphodiester backbone torsion angles

  15. Chemical shifts of oxygen-17 NMR in polyoxotungstates

    International Nuclear Information System (INIS)

    Kazanskij, L.P.; Fedotov, M.A.; Spitsyn, V.I.

    1977-01-01

    17 O NMR spectra of aqueous solutions containing paratungstate BH 2 W 12 O 42 10- and metatungstate H 2 W 12 O 40 6- anions have been measured. On the basis of the obtained data a scale of chemical shifts for oxygen atoms connected by various bonds with tungsten atoms is suggested. The obtained data are compared with the Raman spectra of crystalline salts and their aqueous solutions. Chemical shifts of 17 O NMR spectra have been also measured in other heteropolyanions

  16. Investigation of Oxidative Degradation in Polymers Using (17)O NMR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Todd M.; Celina, Mathew; Assink, Roger A.; Clough, Roger L.; Gillen, Kenneth T.; Wheeler David R.

    1999-07-20

    The thermal oxidation of pentacontane (C{sub 50}H{sub 102}), and of the homopolymer polyisoprene, has been investigated using {sup 17}O NMR spectroscopy. By performing the oxidation using {sup 17}O labeled O{sub 2} gas, it is possible to easily identify degradation products, even at relatively low concentrations. It is demonstrated that details of the degradation mechanism can be obtained from analysis of the {sup 17}O NMR spectra as a function of total oxidation. Pentacontane reveals the widest variety of reaction products, and exhibits changes in the relative product distributions with increasing O{sub 2} consumption. At low levels of oxygen incorporation, peroxides are the major oxidation product, while at later stages of degradation these species are replaced by increasing concentrations of ketones, alcohols, carboxylic acids and esters. Analyzing the product distribution can help in identification of the different free-radical decomposition pathways of hydroperoxides, including recombination, proton abstraction and chain scission, as well as secondary reactions. The {sup 17}O NMR spectra of thermally oxidized polyisoprene reveal fewer degradation functionalities, but exhibit an increased complexity in the type of observed degradation species due to structural features such as unsaturation and methyl branching. Alcohols and ethers formed from hydrogen abstraction and free radical termination.

  17. Correlation measurements of the proton spectra in the backward hemisphere in the reaction pd→ppn at 1.2--1.7 GeV/c

    International Nuclear Information System (INIS)

    Andreev, V.P.; Dobyrn, V.V.; Kravtsov, A.V.

    1985-01-01

    The reaction pd→ppn with emission of one of the nucleons into the backward hemisphere has been studied in a deuterium bubble chamber at eight energies. In contrast to high energies, an energy dependence of the slope of the invariant cross section is observed, which may indicate a dying out of the isobaric mechanism which may be responsible for a constant contribution in the region above 1 GeV. On the other hand, at large backward angles this mechanism remains important also in the region studied. Investigation of angular correlations and momentum spectra made it possible to identify the regions of dominance of the various diagrams. In the spectrum of the effective masses M/sub p/n a peak is observed which can be interpreted as a candidate for a dibaryon resonance

  18. WaVPeak: Picking NMR peaks through wavelet-based smoothing and volume-based filtering

    KAUST Repository

    Liu, Zhi; Abbas, Ahmed; Jing, Bing-Yi; Gao, Xin

    2012-01-01

    Motivation: Nuclear magnetic resonance (NMR) has been widely used as a powerful tool to determine the 3D structures of proteins in vivo. However, the post-spectra processing stage of NMR structure determination usually involves a tremendous amount

  19. Cool-Climate Red Wines—Chemical Composition and Comparison of Two Protocols for 1H–NMR Analysis

    Directory of Open Access Journals (Sweden)

    Violetta Aru

    2018-01-01

    Full Text Available This study investigates the metabolome of 26 experimental cool-climate wines made from 22 grape varieties using two different protocols for wine analysis by proton nuclear magnetic resonance (1H–NMR spectroscopy. The wine samples were analyzed as-is (wet and as dried samples. The NMR datasets were preprocessed by alignment and mean centering. No normalization or scaling was performed. The “wet” method preserved the inherent properties of the samples and provided a fast and effective overview of the molecular composition of the wines. The “dried” method yielded a slightly better sensitivity towards a broader range of the compounds present in wines. A total of 27 metabolites including amino acids, organic acids, sugars, and alkaloids were identified in the 1H–NMR spectra of the wine samples. Principal component analysis was performed on both NMR datasets evidencing well-defined molecular fingerprints for ‘Baco Noir’, ‘Bolero’, ‘Cabernet Cantor’, ‘Cabernet Cortis’, ‘Don Muscat’, ‘Eszter’, ‘Golubok’, ‘New York Muscat’, ‘Regent’, ‘Rondo’, ‘Triomphe d’Alsace’, ‘Précose Noir’, and ‘Vinoslivy’ wines. Amongst the identified metabolites, lactic acid, succinic acid, acetic acid, gallic acid, glycerol, and methanol were found to drive sample groupings. The 1H–NMR data was compared to the absolute concentration values obtained from a reference Fourier transform infrared method, evidencing a high correlation.

  20. Microstructural evolution in modified 9Cr-1Mo ferritic/martensitic steel irradiated with mixed high-energy proton and neutron spectra at low temperatures

    International Nuclear Information System (INIS)

    Sencer, B.H.; Garner, F.A.; Gelles, D.S.; Bond, G.M.; Maloy, S.A.

    2002-01-01

    Modified 9Cr-1Mo ferritic/martensitic steel was exposed at 32-57 deg. C to a mixed proton/neutron particle flux and spectrum at the Los Alamos Neutron Science Center. The microstructure of unirradiated 9Cr-1Mo consists of laths, dislocations and carbides. Examination of electron diffraction patterns obtained from extraction replicas of unirradiated 9Cr-1Mo revealed that the precipitate microstructure was primarily dominated by M 23 C 6 carbides. The post-irradiation microstructure contained black-spot damage in addition to precipitates and dislocations. Examination of electron diffraction patterns revealed diffuse rings from M 23 C 6 carbides, indicating amorphization and/or nanocrystallinity. Crystalline MC carbides were also found. No cavity formation was found although a significant amount of helium and hydrogen generation had been generated. TEM-EDS examination of extraction replicas for carbides from unirradiated and irradiated samples did not show any detectable changes in composition of either M 23 C 6 or MC carbides. There was also no evident change in carbide size. Lattice images of M 23 C 6 carbides revealed an amorphous microstructure following irradiation, but MC carbides were still crystalline

  1. Experimental (FT-IR, FT-Raman, 1H, 13C NMR) and theoretical study of alkali metal 2-aminobenzoates

    Science.gov (United States)

    Samsonowicz, M.; Świsłocka, R.; Regulska, E.; Lewandowski, W.

    2008-09-01

    The influence of lithium, sodium, potassium, rubidium and cesium on the electronic system of the 2-aminobenzoic acid was studied by the methods of molecular spectroscopy. The vibrational (FT-IR, FT-Raman) and NMR ( 1H and 13C) spectra for 2-aminobenzoic acid and its alkali metal salts were recorded. The assignment of vibrational spectra was done on the basis of literature data, theoretical calculations and our previous experience. Characteristic shifts of bands and changes in intensities of bands along the metal series were observed. The changes of chemical shifts of protons ( 1H NMR) and carbons ( 13C NMR) in the series of studied alkali metal 2-aminobenzoates were observed too. Optimized geometrical structures of studied compounds were calculated by B3LYP method using 6-311++G ∗∗ basis set. Geometric aromaticity indices, dipole moments and energies were also calculated. The theoretical wavenumbers and intensities of IR and Raman spectra were obtained. The calculated parameters were compared to experimental characteristic of studied compounds.

  2. NMR spectroscopy of coal pyrolysis products

    Energy Technology Data Exchange (ETDEWEB)

    Polonov, V.M.; Kalabin, G.A.; Kushnarev, D.F.; Shevchenko, G.G.

    1985-12-01

    The authors consider the scope for using H 1 and C 13 NMR spectroscopy to describe the products from coal pyrolysis and hydrogenization. The accuracy of the structural information provided by the best NMR methods is also considered. The stuctural parameters derived from H 1 and C 13 NMR spectra are presented. Results demonstrate the high accuracy and sensitivity of the structural information provided by H 1 AND C 13 NMR spectra for coal products. There are substantial structural differences between the soluble products from medium-temperature coking of Cheremkhov coal and high-speed pyrolysis of Kan-Acha coal, and also differences in behavior during hydrogenation. These differences are related to the structure of the organic matter in the initial coal and to differences in the pyrolysis mechanisms.

  3. High resolution NMR in zeolites

    Energy Technology Data Exchange (ETDEWEB)

    Diaz, Anix [INTEVEP, Filial de Petroleos de Venezuela, SA, Caracas (Venezuela). Dept. de Analisis y Evalucion

    1992-12-31

    In this work {sup 29} Si and {sup 27} Al NMR spectroscopy was used to study various types of zeolites. The corresponding spectra were used to measure the Si/Al ratios, to follow chemical modifications induced by acid and hydrothermal treatments, to determine non-equivalent crystallographic sites in highly dealuminated mordenites, and to detect modifications of faujasites due to the insertion of titanium atoms in the lattice. (author) 7 refs., 7 figs., 2 tabs.

  4. High resolution NMR in zeolites

    International Nuclear Information System (INIS)

    Diaz, Anix

    1991-01-01

    In this work 29 Si and 27 Al NMR spectroscopy was used to study various types of zeolites. The corresponding spectra were used to measure the Si/Al ratios, to follow chemical modifications induced by acid and hydrothermal treatments, to determine non-equivalent crystallographic sites in highly dealuminated mordenites, and to detect modifications of faujasites due to the insertion of titanium atoms in the lattice. (author)

  5. NMR spectroscopy

    International Nuclear Information System (INIS)

    Gruenert, J.

    1989-01-01

    The book reviews the applications of NMR-spectroscopy in medicine and biology. The first chapter of about 40 pages summarizes the history of development and explains the chemical and physical fundamentals of this new and non-invasive method in an easily comprehensible manner. The other chapters summarize diagnostic results obtained with this method in organs and tissues, so that the reader will find a systematic overview of the available findings obtained in the various organ systems. It must be noted, however, that ongoing research work and new insight quite naturally will necessitate corrections to be done, as is the case here with some biochemical interpretations which would need adjustment to latest research results. NMR-spectroscopy is able to measure very fine energy differences on the molecular level, and thus offers insight into metabolic processes, with the advantage that there is no need of applying ionizing radiation in order to qualitatively or quantitatively analyse the metabolic processes in the various organ systems. (orig./DG) With 40 figs., 4 tabs [de

  6. Influence of protonation or alkylation of the phosphate group on the e. s. r. spectra and on the rate of phosphate elimination from 2-methoxyethyl phosphate 2-yl radicals. [. gamma. rays

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, G; Koltzenburg, G; Ritter, A; Schulte-Frohlinde, D [Max-Planck-Institut fuer Kohlenforschung, Muelheim an der Ruhr (Germany, F.R.). Inst. fuer Strahlenchemie

    1978-02-01

    The e.s.r. spectra of l-yl, 2-yl and 3'-yl methoxethyl phosphate radicals derived from CH/sub 3/OCH/sub 2/CH/sub 2/-OPO/sub 3/H/sub 2/ by hydrogen abstraction have been measured in aqueous solutions and the hyperfine constants determined. The coupling constants vary strongly with protonation or alkylation of the phosphate group. The 2-yl radicals eliminate phosphate. The rate-constants for the elimination (ksub(e)) have been estimated by e.s.r. measurements and by product studies as a function of pH using /sup 60/Co ..gamma..-radiolysis. The ksub(e) values vary from approximately 0.3 s/sup -1/ for the CH/sub 3/OCHCH/sub 2/OPO/sub 3//sup - -/ radical and approximately 10/sup 3/s/sup -1/ for CH/sub 3/OCHCH/sub 2/OPO/sub 3/H/sup -/, to approximately 3 x 10/sup 6/s/sup -1/ for CH/sub 3/OCHCH/sub 2/OPO/sub 3/H/sub 2/. Alkylation of the phosphate group increased the elimination rate-constant to a similar extent as protonation. The results support a recent mechanism which described the OH-radical-induced single-strand breaks of DNA in aqueous solution starting from the C-4' radical of the sugar moiety. It is further concluded the C-4' radical of DNA eliminates the 3'-phosphate group faster than the 5'-phosphate group.

  7. Oriented solid-state NMR spectrosocpy

    DEFF Research Database (Denmark)

    Bertelsen, Kresten

    This thesis is concerned with driving forward oriented solid-state NMR spectroscopy as a viable technique for studying peptides in membrane bilayers. I will show that structural heterogeneity is an intrinsic part of the peptide/lipid system and that NMR can be used to characterize static...... and dynamic structural features of the peptides and its local surroundings. In fact one need to take into account the dynamical features of the system in order to correctly predict the structure from oriented solid-state NMR spectra.      ...

  8. Graphical programming for pulse automated NMR experiments

    International Nuclear Information System (INIS)

    Belmonte, S.B.; Oliveira, I.S.; Guimaraes, A.P.

    1999-01-01

    We describe a software program designed to control a broadband pulse Nuclear Magnetic Resonance (NMR) spectrometer used in zero-field NMR studies of magnetic metals. The software is written in the graphical language LabVIEW. This type of programming allows modifications and the inclusion of new routines to be easily made by the non-specialist, without changing the basic structure of the program. The program corrects for differences in the gain of the two acquisition channels [U (phase) and V (quadrature)], and automatic baseline subtraction. We present examples of measurements of NMR spectra, spin-echo decay (T 2 ), and quadrupolar oscillations, performed in magnetic intermetallic compounds. (author)

  9. Metabolic profiling of lymph from pigs fed with ß-glucan by high-resolution 1H NMR spectroscopy

    DEFF Research Database (Denmark)

    Larsen, Flemming Hofmann; Jørgensen, Henry Johs. Høgh; Engelsen, Søren Balling

    2010-01-01

    To gain information about the effect of ingesting different β-glucan sources on intestinal lymph metabolic profile, 10 growing pigs (30-36 kg) were fitted with a catheter in the jejunal lymphatic trunk, and lymph samples collected continuously -1 to 8 h postprandial and again at 24 h after feeding...... a diet containing either 0.4% added yeast or barley β-glucan and compared to a Control diet. The lymph samples were analysed by proton nuclear magnetic resonance (1H NMR) spectroscopy and subsequently subjected to chemometric analysis. The dominant resonances in the 1H NMR spectra of lymph arose...... of increased lymph viscosity induced by barley β-glucan compared to yeast β-glucan were observed...

  10. Influence of the nature of soil organic matter on the sorption behaviour of pentadecane as determined by PLS analysis of mid-infrared DRIFT and solid-state {sup 13}C NMR spectra

    Energy Technology Data Exchange (ETDEWEB)

    Clark Ehlers, G.A. [Institute of Environmental Biotechnology, Department IFA-Tulln, University of Natural Resources and Applied Life Sciences, Vienna, Konrad Lorenz Str. 20, Tulln A-3430 (Austria); Forrester, Sean T. [CSIRO Land and Water, Waite Rd, Urrbrae SA 5064 (Australia); Scherr, Kerstin E. [Institute of Environmental Biotechnology, Department IFA-Tulln, University of Natural Resources and Applied Life Sciences, Vienna, Konrad Lorenz Str. 20, Tulln A-3430 (Austria); Loibner, Andreas P., E-mail: andreas.loibner@boku.ac.a [Institute of Environmental Biotechnology, Department IFA-Tulln, The University of Natural Resources and Applied Life Sciences, Vienna, Konrad Lorenz Str. 20, Tulln A-3430 (Austria); Janik, Les J. [CSIRO Land and Water, Waite Rd, Urrbrae SA 5064 (Australia)

    2010-01-15

    The nature of soil organic matter (SOM) functional groups associated with sorption processes was determined by correlating partitioning coefficients with solid-state {sup 13}C nuclear magnetic resonance (NMR) and diffuse reflectance mid-infrared (DRIFT) spectral features using partial least squares (PLS) regression analysis. Partitioning sorption coefficients for n-pentadecane (n-C{sub 15}) were determined for three alternative models: the Langmuir model, the dual distributed reactive domain model (DRDM) and the Freundlich model, where the latter was found to be the most appropriate. NMR-derived constitutional descriptors did not correlate with Freundlich model parameters. By contrast, PLS analysis revealed the most likely nature of the functional groups in SOM associated with n-C{sub 15} sorption coefficients (K{sub F}) to be aromatic, possibly porous soil char, rather than aliphatic organic components for the presently investigated soils. High PLS cross-validation correlation suggested that the model was robust for the purpose of characterising the functional group chemistry important for n-C{sub 15} sorption. - NMR/IR spectroscopy and chemometrics reveal the aromatic fraction of soil organic matter being responsible for alkane sorption.

  11. NMR study of hyper-polarized {sup 129}Xe and applications to liquid-phase NMR experiments; Etude de la resonance magnetique nucleaire du Xenon{sup 129} hyperpolarise et applications en RMN des liquides

    Energy Technology Data Exchange (ETDEWEB)

    Marion, D

    2008-07-15

    In liquid samples where both nuclear polarization and spin density are strong, the magnetization dynamics, which can be analysed by NMR (nuclear magnetic resonance) methods, is deeply influenced by the internal couplings induced by local dipolar fields. The present thesis describes some of the many consequences associated to the presence in the sample of concentrated xenon hyper-polarized by an optical pumping process. First, we deal with the induced modifications in frequency and line width of the proton and xenon spectra, then we present the results of SPIDER, a coherent polarization transfer experiment designed to enhance the polarization of protons, in order to increase their NMR signal level. A third part is dedicated to the description of the apparition of repeated chaotic maser emissions by un unstable xenon magnetization coupled to the detection coil tuned at the xenon Larmor frequency (here 138 MHz). In the last part, we present a new method allowing a better tuning of any NMR detection probe and resulting in sensible gains in terms of sensitivity and signal shaping. Finally, we conclude with a partial questioning of the classical relaxation theory in the specific field of highly polarized and concentrated spin systems in a liquid phase. (author)

  12. Proton diffraction

    International Nuclear Information System (INIS)

    Den Besten, J.L.; Jamieson, D.N.; Allen, L.J.

    1998-01-01

    The Lindhard theory on ion channeling in crystals has been widely accepted throughout ion beam analysis for use in simulating such experiments. The simulations use a Monte Carlo method developed by Barret, which utilises the classical 'billiard ball' theory of ions 'bouncing' between planes or tubes of atoms in the crystal. This theory is not valid for 'thin' crystals where the planes or strings of atoms can no longer be assumed to be of infinite proportions. We propose that a theory similar to that used for high energy electron diffraction can be applied to MeV ions, especially protons, in thin crystals to simulate the intensities of transmission channeling and of RBS spectra. The diffraction theory is based on a Bloch wave solution of the Schroedinger equation for an ion passing through the periodic crystal potential. The widely used universal potential for proton-nucleus scattering is used to construct the crystal potential. Absorption due to thermal diffuse scattering is included. Experimental parameters such as convergence angle, beam tilt and scanning directions are considered in our calculations. Comparison between theory and experiment is encouraging and suggests that further work is justified. (authors)

  13. Development and applications of quantitative NMR spectroscopy

    International Nuclear Information System (INIS)

    Yamazaki, Taichi

    2016-01-01

    Recently, quantitative NMR spectroscopy has attracted attention as an analytical method which can easily secure traceability to SI unit system, and discussions about its accuracy and inaccuracy are also started. This paper focuses on the literatures on the advancement of quantitative NMR spectroscopy reported between 2009 and 2016, and introduces both NMR measurement conditions and actual analysis cases in quantitative NMR. The quantitative NMR spectroscopy using an internal reference method enables accurate quantitative analysis with a quick and versatile way in general, and it is possible to obtain the precision sufficiently applicable to the evaluation of pure substances and standard solutions. Since the external reference method can easily prevent contamination to samples and the collection of samples, there are many reported cases related to the quantitative analysis of biologically related samples and highly scarce natural products in which NMR spectra are complicated. In the precision of quantitative NMR spectroscopy, the internal reference method is superior. As the quantitative NMR spectroscopy widely spreads, discussions are also progressing on how to utilize this analytical method as the official methods in various countries around the world. In Japan, this method is listed in the Pharmacopoeia and Japanese Standard of Food Additives, and it is also used as the official method for purity evaluation. In the future, this method will be expected to spread as the general-purpose analysis method that can ensure traceability to SI unit system. (A.O.)

  14. Acceleration of natural-abundance solid-state MAS NMR measurements on bone by paramagnetic relaxation from gadolinium-DTPA

    Science.gov (United States)

    Mroue, Kamal H.; Zhang, Rongchun; Zhu, Peizhi; McNerny, Erin; Kohn, David H.; Morris, Michael D.; Ramamoorthy, Ayyalusamy

    2014-07-01

    Reducing the data collection time without affecting the signal intensity and spectral resolution is one of the major challenges for the widespread application of multidimensional nuclear magnetic resonance (NMR) spectroscopy, especially in experiments conducted on complex heterogeneous biological systems such as bone. In most of these experiments, the NMR data collection time is ultimately governed by the proton spin-lattice relaxation times (T1). For over two decades, gadolinium(III)-DTPA (Gd-DTPA, DTPA = Diethylene triamine pentaacetic acid) has been one of the most widely used contrast-enhancement agents in magnetic resonance imaging (MRI). In this study, we demonstrate that Gd-DTPA can also be effectively used to enhance the longitudinal relaxation rates of protons in solid-state NMR experiments conducted on bone without significant line-broadening and chemical-shift-perturbation side effects. Using bovine cortical bone samples incubated in different concentrations of Gd-DTPA complex, the 1H T1 values were calculated from data collected by 1H spin-inversion recovery method detected in natural-abundance 13C cross-polarization magic angle spinning (CPMAS) NMR experiments. Our results reveal that the 1H T1 values can be successfully reduced by a factor of 3.5 using as low as 10 mM Gd-DTPA without reducing the spectral resolution and thus enabling faster data acquisition of the 13C CPMAS spectra. These results obtained from 13C-detected CPMAS experiments were further confirmed using 1H-detected ultrafast MAS experiments on Gd-DTPA doped bone samples. This approach considerably improves the signal-to-noise ratio per unit time of NMR experiments applied to bone samples by reducing the experimental time required to acquire the same number of scans.

  15. Study on the interactions PVC/plasticizers by NMR

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Maria I.B.; Monteiro, Elisabeth E.C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Macromoleculas; Harris, Robin [Durham Univ. (United Kingdom). Dept. of Chemistry

    1992-12-31

    The nature of the interactions between PVC and plasticizers as di-butyl phthalate and di-2-ethyl-hexyl phthalate can be investigated using proton/carbon-13 NMR techniques. The measurements of T{sub 1} for protons and carbon-13 and T{sub 1} P for protons can provide a good source of information about the complex behaviour for those two systems which were investigated. (author) 14 refs., 5 figs., 1 tab.

  16. Unified integration intervals for the structural characterization of oil, coal or fractions there of by 1h NMR and 13c NMR

    International Nuclear Information System (INIS)

    Avella, Eliseo; Fierro, Ricardo

    2010-01-01

    Based on an analysis of publications reported between 1972 and 2006, it became clear that there are inaccuracies in the limits of the ranges of integration that the authors assigned to signals in nuclear magnetic resonance (NMR) to the structural characterization of petroleum, coals and their derived fractions, from their hydrogen (1H NMR) and carbon (13C NMR) spectra. Consequently, consolidated limits were determined for the integration of 1H NMR spectra and 13C NMR of these samples using a statistical treatment applied to the limits of integration intervals already published. With these unified limits, correlation NMR charts were developed that are useful for the al