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Sample records for 1h 31p 77se

  1. 31P to 77Se cross polarization in beta-P4Se3.

    PubMed

    Pietrass, T; Seydoux, R; Roth, R E; Eckert, H; Pines, A

    1997-08-01

    Cross polarization from 31P to 77Se is demonstrated in beta-P4Se3. This material, an inorganic glass, is readily synthesized from the elements and serves as a convenient sample for setting the Hartmann-Hahn condition.

  2. Probing phosphorylation by non-mammalian isoprenoid biosynthetic enzymes using (1)H-(31)P-(31)P correlation NMR spectroscopy.

    PubMed

    Majumdar, Ananya; Shah, Meha H; Bitok, J Kipchirchir; Hassis-LeBeau, Maria E; Freel Meyers, Caren L

    2009-09-01

    The biogenesis of isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) is accomplished by the methylerythritol phosphate (MEP) pathway in plants, bacteria and parasites, making it a potential target for the development of anti-infective agents and herbicides. The biosynthetic enzymes comprising this pathway catalyze intriguing chemical transformations on diphosphate scaffolds, offering an opportunity to generate novel analogs in this synthetically challenging compound class. Such a biosynthetic approach to generating new diphosphate analogs may involve transformation through discrete diphosphate species, presenting unique challenges in structure determination and characterization of unnatural enzyme-generated diphosphate products produced in tandem. We have developed (1)H-(31)P-(31)P correlation NMR spectroscopy techniques for the direct characterization of crude MEP pathway enzyme products at low concentrations (200 microM to 5 mM) on a room temperature (non-cryogenic) NMR probe. Coupling the 100% natural abundance of the (31)P nucleus with the high intrinsic sensitivity of proton NMR, (1)H-(31)P-(31)P correlation spectroscopy is particularly useful for characterization of unnatural diphosphate enzyme products in the MEP pathway. As proof of principle, we demonstrate the rapid characterization of natural enzyme products of the enzymes IspD, E and F in tandem enzyme incubations. In addition, we have characterized several unnatural enzyme products using this technique, including new products of cytidyltransferase IspD bearing erythritol, glycerol and ribose components. The results of this study indicate that IspD may be a useful biocatalyst and highlight (1)H-(31)P-(31)P correlation spectroscopy as a valuable tool for the characterization of other unnatural products in non-mammalian isoprenoid biosynthesis.

  3. Evaluation of a New 1H/31P Dual-Tuned Birdcage Coil for 31P Spectroscopy

    PubMed Central

    Potter, WM; Wang, L; McCully, KK; Zhao, Q

    2013-01-01

    We introduce a new dual-tuned Hydrogen/Phosphorus (1H/31P) birdcage coil, referred to as split birdcage coil, and evaluate its performance using both simulations and magnetic resonance (MR) experiments on a 3 T MR scanner. The proposed coil simplifies the practical matters of tuning and matching, which makes the coil easily reproducible. Simulations were run with the Finite Difference in Time Domain (FDTD) method to evaluate the sensitivity and homogeneity of the magnetic field generated by the proposed 1H coils. Following simulations, MR experiments were conducted using both a phantom and human thigh to compare the proposed design with a currently available commercial dual-tuned flexible surface coil, referred to as flex surface coil, for signal to noise ratio (SNR) as well as homogeneity for the 31P coil. At regions deep within the human thigh, the split birdcage coil was able to acquire spectroscopic signal with a higher average SNR than the flex surface coil. For all regions except those close to the flex surface coil, the split birdcage coil matched or exceeded the performance of the flex surface coil. PMID:24039555

  4. Size- and site-dependent reconstruction in CdSe QDs evidenced by 77Se{1H} CP-MAS NMR spectroscopy.

    PubMed

    Lovingood, Derek D; Achey, Randall; Paravastu, Anant K; Strouse, Geoffrey F

    2010-03-17

    Evidence of size-dependent reconstruction in quantum dots leading to changes in bonding is observed through analysis of the (77)Se{(1)H} cross-polarization magic angle spinning and (77)Se spin-echo solid-state NMR for Cd(77)Se quantum dots. The CP-MAS and spin-echo data indicate discrete surface and core (77)Se sites exist with the QD, in which the surface is comprised of numerous reconstructed lattice planes. Due to the nearly 100% enrichment level for (77)Se, efficient spin coupling is observed between the surface (77)Se and sublayer (77)Se sites due to spin diffusion in the Cd(77)Se quantum dots. The observed chemical shift for the discrete (77)Se sites can be correlated to the effective mass approximation via the Ramsey expression, indicating a 1/r(2) size dependence for the change in chemical shift with size, while a plot of chemical shift versus the inverse band gap is linear. The correlation of NMR shift for the discrete sites allows a valence bond theory interpretation of the size-dependent changes in bonding character within the reconstructed QD. The NMR results provide a structural model for the QDs in which global reconstruction occurs below 4 nm in diameter, while an apparent self-limiting reconstruction process occurs above 4 nm.

  5. 4 T Actively-Detuneable Double-Tuned 1H/31P Head Volume Coil and Four-Channel 31P Phased Array for Human Brain Spectroscopy

    PubMed Central

    Avdievich, N.I.; Hetherington1, H.P.

    2009-01-01

    Typically 31P in vivo magnetic resonance spectroscopic studies are limited by SNR considerations. Although phased arrays can improve the SNR; to date 31P phased arrays for high-field systems have not been combined with 31P volume transmit coils. Additionally, to provide anatomical reference for the 31P studies, without removal of the coil or patient from the magnet, double-tuning (31P/ 1H) of the volume coil is required. In this work we describe a series of methods for active detuning and decoupling enabling use of phased arrays with double-tuned volume coils. To demonstrate these principles we have built and characterized an actively detuneable 31P/1H TEM volume transmit/ four-channel 31P phased array for 4 T magnetic resonance spectroscopic imaging (MRSI) of the human brain. The coil can be used either in volume-transmit/array-receive mode or in TEM transmit/receive mode with the array detuned. Three-fold SNR improvement was obtained at the periphery of the brain using the phased array as compared to the volume coil. PMID:17379554

  6. 4 T Actively detuneable double-tuned 1H/ 31P head volume coil and four-channel 31P phased array for human brain spectroscopy

    NASA Astrophysics Data System (ADS)

    Avdievich, N. I.; Hetherington, H. P.

    2007-06-01

    Typically 31P in vivo magnetic resonance spectroscopic studies are limited by SNR considerations. Although phased arrays can improve the SNR; to date 31P phased arrays for high-field systems have not been combined with 31P volume transmit coils. Additionally, to provide anatomical reference for the 31P studies, without removal of the coil or patient from the magnet, double-tuning ( 31P/ 1H) of the volume coil is required. In this work we describe a series of methods for active detuning and decoupling enabling use of phased arrays with double-tuned volume coils. To demonstrate these principles we have built and characterized an actively detuneable 31P/ 1H TEM volume transmit/four-channel 31P phased array for 4 T magnetic resonance spectroscopic imaging (MRSI) of the human brain. The coil can be used either in volume-transmit/array-receive mode or in TEM transmit/receive mode with the array detuned. Threefold SNR improvement was obtained at the periphery of the brain using the phased array as compared to the volume coil.

  7. Open-chain unsaturated selanyl sulfides: stereochemical structure and stereochemical behavior of their 77Se-1H spin-spin coupling constants.

    PubMed

    Rusakov, Yury Yu; Krivdin, Leonid B; Penzik, Maxim V; Potapov, Vladimir A; Amosova, Svetlana V

    2012-10-01

    Stereochemical structure of nine Z-2-(vinylsulfanyl)ethenylselanyl organyl sulfides has been investigated by means of experimental measurements and second-order polarization propagator approach calculations of their (1)H-(1)H, (13)C-(1)H, and (77)Se-(1)H spin-spin coupling constants together with a theoretical conformational analysis performed at the MP2/6-311G** level. All nine compounds were shown to adopt the preferable skewed s-cis conformation of their terminal vinylsulfanyl group, whereas the favorable rotational conformations with respect to the internal rotations around the C-S and C-Se bonds of the internal ethenyl group are both skewed s-trans. Stereochemical trends of (77)Se-(1)H spin-spin coupling constants originating in the geometry of their coupling pathways and the selenium lone pair effect were rationalized in terms of the natural J-coupling analysis within the framework of the natural bond orbital approach.

  8. Versatile 1H-31P-31P COSY 2D NMR Techniques for the Characterization of Polyphosphorylated Small Molecules

    PubMed Central

    Majumdar, Ananya; Sun, Yan; Shah, Meha; Freel Meyers, Caren L.

    2010-01-01

    Di- and triphosphorylated small molecules represent key intermediates in a wide range of biological and chemical processes. The importance of polyphosphorylated species in biology and medicine underscores the need to develop methods for the detection and characterization of this compound class. We have reported two-dimensional HPP-COSY spectroscopy techniques to identify diphosphate-containing metabolic intermediates at sub-millimolar concentrations in the methylerythritol phosphate (MEP) isoprenoid biosynthetic pathway.1 In this work, we explore the scope of HPP-COSY based techniques to characterize a diverse group of small organic molecules bearing di- and tri-phosphorylated moieties. These include molecules containing P–O–P and P–C–P connectivities, multivalent P(III)–O–P(V) phosphorus nuclei with widely separated chemical shifts, as well as virtually overlapping 31P resonances exhibiting strong coupling effects. We also demonstrate the utility of these experiments to rapidly distinguish between mono- and diphosphates. A detailed protocol for optimizing these experiments to achieve best performance is presented. PMID:20408590

  9. Intrauterine fetal brain NMR spectroscopy: 1H and 31P studies in rats

    SciTech Connect

    Nakada, T.; Kwee, I.L.; Suzuki, N.; Houkin, K. )

    1989-11-01

    Fetal brain metabolism was investigated in utero noninvasively using multinuclear nuclear magnetic resonance spectroscopy in rats at two representative prenatal stages: early (17-18 days) and late (20-21 days) stages. Phosphorus-31 (31P) spectroscopy revealed that phosphocreatine is significantly lower in the early stage and increases to the level of early neonates by the late prenatal stage. Intracellular pH at the early stage was found to be strikingly high (7.52 +/- 0.21) and decreased to a level similar to that of neonates by the late stage (7.29 +/- 0.07). Phosphomonoester levels at both stages were similar to the values reported for early neonates. Water-suppressed proton (1H) spectroscopy demonstrated a distinctive in vivo fetal brain spectral pattern characterized by low levels of N-acetyl aspartate and high levels of taurine. High-resolution proton spectroscopy and homonuclear chemical-shift correlate spectroscopy of brain perchloric acid extracts confirmed these in vivo findings. In vitro 31P spectroscopy of acidified chloroform methanol extracts showed the characteristic membrane phospholipid profiles of fetal brain. The phosphatidylethanolamine (PE)-to-phosphatidylcholine (PC) ratio (PE/PC) did not show significant changes between the two stages at 0.40 +/- 0.11, a value similar to that of early neonates.

  10. Direct and simultaneous quantification of ATP, ADP and AMP by (1)H and (31)P Nuclear Magnetic Resonance spectroscopy.

    PubMed

    Lian, Yakun; Jiang, Hua; Feng, Jinzhou; Wang, Xiaoyan; Hou, Xiandeng; Deng, Pengchi

    2016-04-01

    ATP, ADP and AMP are energy substances with vital biological significance. Based on the structural differences, a simple, rapid and comprehensive method has been established by (1)H and (31)P Nuclear Magnetic Resonance ((1)H-NMR and (31)P-NMR) spectroscopies. Sodium 3-(trimethylsilyl) propionate-2,2,3,3-d4 (TMSP) and anhydrous disodium hydrogen phosphate (Na2HPO4) were selected as internal standards for (1)H-NMR and (31)P-NMR, respectively. Those three compounds and corresponding internal standards can be easily distinguished both by (1)H-NMR and (31)P-NMR. In addition, they all have perfect linearity in a certain range: 0.1-100mM for (1)H-NMR and 1-75 mM for (31)P-NMR. To validate the precision of this method, mixed samples of different concentrations were measured. Recovery experiments were conducted in serum (91-113% by (1)H-NMR and 89-113% by (31)P-NMR).

  11. Bone Mineral 31P and Matrix-Bound Water Densities Measured by Solid-State 1H and 31P MRI

    PubMed Central

    Seifert, Alan C.; Li, Cheng; Rajapakse, Chamith S.; Bashoor- Zadeh, Mahdieh; Bhagat, Yusuf A.; Wright, Alexander C.; Zemel, Babette S.; Zavaliangos, Antonios; Wehrli, Felix W.

    2014-01-01

    Bone is a composite material consisting of mineral and hydrated collagen fractions. MRI of bone is challenging due to extremely short transverse relaxation times, but solid-state imaging sequences exist that can acquire the short-lived signal from bone tissue. Previous work to quantify bone density via MRI used powerful experimental scanners. This work seeks to establish the feasibility of MRI-based measurement on clinical scanners of bone mineral and collagen-bound water densities, the latter as a surrogate of matrix density, and to examine the associations of these parameters with porosity and donors’ age. Mineral and matrix-bound water images of reference phantoms and cortical bone from 16 human donors, ages 27-97 years, were acquired by zero-echo-time 31P and 1H MRI on whole body 7T and 3T scanners, respectively. Images were corrected for relaxation and RF inhomogeneity to obtain density maps. Cortical porosity was measured by micro-CT, and apparent mineral density by pQCT. MRI-derived densities were compared to x-ray-based measurements by least-squares regression. Mean bone mineral 31P density was 6.74±1.22 mol/L (corresponding to 1129±204 mg/cc mineral), and mean bound water 1H density was 31.3±4.2 mol/L (corresponding to 28.3±3.7 %v/v). Both 31P and bound water (BW) densities were correlated negatively with porosity (31P: R2 = 0.32, p < 0.005; BW: R2 = 0.63, p < 0.0005) and age (31P: R2 = 0.39, p < 0.05; BW: R2 = 0.70, p < 0.0001), and positively with pQCT density (31P: R2 = 0.46, p < 0.05; BW: R2 = 0.50, p < 0.005). In contrast, the bone mineralization ratio (expressed here as the ratio of 31P density to bound water density), which is proportional to true bone mineralization, was found to be uncorrelated with porosity, age, or pQCT density. This work establishes the feasibility of image-based quantification of bone mineral and bound water densities using clinical hardware. PMID:24846186

  12. Lipid composition of integral purple membrane by 1H and 31P NMR.

    PubMed

    Renner, Christian; Kessler, Brigitte; Oesterhelt, Dieter

    2005-08-01

    In the purple membrane (PM) of halobacteria, lipids stabilize the trimeric arrangement of bacteriorhodopsin (BR) molecules and mediate the packing of the trimers in a regular crystalline arrangement. To date, the identification and quantification of these lipids has been based either on lipid extraction procedures or structural models. By directly solubilizing PMs from Halobacterium salinarum in aqueous detergent solutions (SDS or Triton X-100), we avoided any separation or modification steps that might modify the lipid composition or even the lipid molecules themselves. Our analysis of integral PM preparations should resolve partially conflicting literature data on the lipid composition of the PM. Using 31P and 1H NMR of detergent-solubilized but otherwise untreated samples, we found two glycolipids and 6.4 +/- 0.1 phospholipids per BR molecule, 4.4 +/- 0.1 of the latter being the phosphatidylglycerophosphate methyl ester. The only glycolipid detected was S-TGD-1. For an additional glycolipid, glycocardiolipin, that was recently identified in lipid extracts, we show that it was produced mainly during the lipid extraction procedure but also was partially dependent on the preparation of the PM suspensions.

  13. Combined (1)H and (31)P spectroscopy provides new insights into the pathobiochemistry of brain damage in multiple sclerosis.

    PubMed

    Hattingen, Elke; Magerkurth, Jörg; Pilatus, Ulrich; Hübers, Annemarie; Wahl, Mathias; Ziemann, Ulf

    2011-06-01

    (1)H MRSI has evolved as an important tool to study the onset and progression of brain damage in multiple sclerosis. Abnormal increases in total creatine, total choline and myoinositol have been noted in multiple sclerosis. However, the pathobiochemical mechanisms related to these changes are still largely unclear. The combination of (1)H MRSI and (1)H-decoupled (31)P MRSI can specify to what extent phosphorylated components of total creatine and total choline contribute to this increase. Combined (1)H and (31)P MRSI data were obtained at 3 T in 22 patients with multiple sclerosis and in 23 healthy controls, and aligned with structural MRI to allow for correction for partial volume effects caused by cerebrospinal fluid and lesion load. A significant increase in total creatine was found in multiple sclerosis, and this was attributed to equal changes in the phosphorylated and unphosphorylated components. The concentrations of the putative glial markers total creatine and myoinositol in lesion-free (1)H MRSI voxels correlated with the global lesion load. We conclude that changes in total creatine are not related to altered energy metabolism, but rather indicate gliosis. Together with the increase in myoinositol, total creatine can be considered as a biomarker for disease severity. A significant total choline increase was mainly a result of choline components not visible by (31)P MRS. The origin of this residual choline fraction remains to be investigated. Copyright © 2010 John Wiley & Sons, Ltd.

  14. Iterative reconstruction of radially-sampled (31)P bSSFP data using prior information from (1)H MRI.

    PubMed

    Rink, Kristian; Benkhedah, Nadia; Berger, Moritz C; Gnahm, Christine; Behl, Nicolas G R; Lommen, Jonathan M; Stahl, Vanessa; Bachert, Peter; Ladd, Mark E; Nagel, Armin M

    2017-04-01

    The purpose of this study is to improve direct phosphorus ((31)P) MR imaging. Therefore, 3D density-adapted radially-sampled balanced steady-state free precession (bSSFP) sequences were developed and an iterative approach exploiting additional anatomical information from hydrogen ((1)H) data was evaluated. Three healthy volunteers were examined at B0=7T in order to obtain the spatial distribution of the phosphocreatine (PCr) intensities in the human calf muscle with a nominal isotropic resolution of 10mm in an acquisition time of 10min. Three different bSSFP gradient schemes were investigated. The highest signal-to-noise ratio (SNR) was obtained for a scheme with two point-reflected density-adapted gradients. Furthermore, the conventional reconstruction based on a gridding algorithm was compared to an iterative method using an (1)H MRI constraint in terms of a segmented binary mask, which comprises prior knowledge. The parameters of the iterative approach were optimized and evaluated by simulations featuring (31)P MRI parameters. Thereby, partial volume effects as well as Gibbs ringing artifacts could be reduced. In conclusion, the iterative reconstruction of (31)P bSSFP data using an (1)H MRI constraint is appropriate for investigating regions where sharp tissue boundaries occur and leads to images that represent the real PCr distributions better than conventionally reconstructed images. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Proton 1H- and Phosphorus 31P-MR spectroscopy (MRS) in asymptomatic HIV-positive patients

    PubMed Central

    Schuettfort, Gundolf; Hattingen, Elke; Pilatus, Ulrich; Stephan, Christoph; Wolf, Timo; Goepel, Siri; Haberl, Annette; Blasel, Stella; Zanella, Freidhelm; Brodt, Hans-Reinhard; Bickel, Markus

    2014-01-01

    Introduction HIV infection is accompanied by a variety of neurological disorders. Depression of cell-mediated immunity is followed by the development of central nervous system opportunistic infections/tumours, and frequently by the occurrence of the AIDS dementia complex (ADC). However, the pathophysiology of the emergence of neuro-AIDS is still unknown. Despite the development of cognitive impairments, the early diagnosis, objectification and quantification of the existence and extent of this impairment during infection are difficult to recognize in each individual case. To support the early diagnosis of ADC, there is a need for additional, non-invasive diagnostic methods. In this study, it is of interest to answer the clinically relevant question of whether magnetic resonance spectroscopy can detect changes in the cerebral metabolism of asymptomatic HIV-positive patients and is possibly suitable for the early diagnosis and prevention of HIV encephalopathy. Methods A group of 13 asymptomatic, HIV-positive patients with combined antiretroviral therapy (cART) and 13 healthy controls were examined with 2D 1H-MRS and 3D 31P-MRS at 3T. The patients were treated with cART for at least 12 months. Changes in the absolute concentrations of phosphorylated metabolites (ATP), N-acetyl-aspartate, creatine, myo-Isonitol, glutamate/glutamine and choline-containing compounds were compared with that of control subjects. Results Asymptomatic HIV-positive patients had significantly lower N-acetyl-aspartate in the white matter in a frontal and parietal target region. The other evaluated metabolites in the 1H MRS showed no significant difference between the HIV-positive patients and healthy controls. The 31P-MRS detected significant elevated values regarding the choline-containing compounds PEth, GPE and PCho. Conclusions This spectroscopic study revealed a significantly lower N-acetyl-aspartate in the white matter in a frontal and parietal cerebral target region in asymptomatic, HIV

  16. Proton 1H- and Phosphorus 31P-MR spectroscopy (MRS) in asymptomatic HIV-positive patients.

    PubMed

    Schuettfort, Gundolf; Hattingen, Elke; Pilatus, Ulrich; Stephan, Christoph; Wolf, Timo; Goepel, Siri; Haberl, Annette; Blasel, Stella; Zanella, Freidhelm; Brodt, Hans-Reinhard; Bickel, Markus

    2014-01-01

    HIV infection is accompanied by a variety of neurological disorders. Depression of cell-mediated immunity is followed by the development of central nervous system opportunistic infections/tumours, and frequently by the occurrence of the AIDS dementia complex (ADC). However, the pathophysiology of the emergence of neuro-AIDS is still unknown. Despite the development of cognitive impairments, the early diagnosis, objectification and quantification of the existence and extent of this impairment during infection are difficult to recognize in each individual case. To support the early diagnosis of ADC, there is a need for additional, non-invasive diagnostic methods. In this study, it is of interest to answer the clinically relevant question of whether magnetic resonance spectroscopy can detect changes in the cerebral metabolism of asymptomatic HIV-positive patients and is possibly suitable for the early diagnosis and prevention of HIV encephalopathy. A group of 13 asymptomatic, HIV-positive patients with combined antiretroviral therapy (cART) and 13 healthy controls were examined with 2D 1H-MRS and 3D 31P-MRS at 3T. The patients were treated with cART for at least 12 months. Changes in the absolute concentrations of phosphorylated metabolites (ATP), N-acetyl-aspartate, creatine, myo-Isonitol, glutamate/glutamine and choline-containing compounds were compared with that of control subjects. Asymptomatic HIV-positive patients had significantly lower N-acetyl-aspartate in the white matter in a frontal and parietal target region. The other evaluated metabolites in the 1H MRS showed no significant difference between the HIV-positive patients and healthy controls. The 31P-MRS detected significant elevated values regarding the choline-containing compounds PEth, GPE and PCho. This spectroscopic study revealed a significantly lower N-acetyl-aspartate in the white matter in a frontal and parietal cerebral target region in asymptomatic, HIV-positive patients as an early sign of

  17. In vivo nuclear Overhauser effect in sup 31 P-(1H) double-resonance experiments in a 1. 5-T whole-body MR system

    SciTech Connect

    Bachert-Baumann, P.; Ermark, F.; Zabel, H.J.; Sauter, R.; Semmler, W.; Lorenz, W.J. )

    1990-07-01

    In {sup 31}P-(1H) MR experiments of humans in a 1.5-T whole-body system, signal intensity enhancements of {sup 31}P resonances of up to 68 +/- 4% (for phosphocreatine of the calf muscle) have been observed upon irradiation at proton frequency. This observation is explained as a nuclear Overhauser effect due to the dipolar coupling between {sup 1}H and {sup 31}P spins.

  18. 31P{1H}NMR and carbonyl force constants of unsymmetrical bidentate phosphine complexes of group (VI) metal carbonyls

    NASA Astrophysics Data System (ADS)

    Jesu Raj, Joe Gerald; Pathak, Devendra Deo; Kapoor, Pramesh N.

    2015-05-01

    In our present work we report synthesis of an unsymmetrical diphos ligand, 1-diphenylphosphino-2-di-m-tolylphosphinoethane and its coordinate complexes with group (VI) metal carbonyls such as Cr(CO)6 Mo(CO)6 and W(CO)6. The synthesized ligand and its complexes have been completely characterized by elemental analyses, FTIR, 1HNMR, 31P{1H}NMR and FAB mass spectrometry methods. Special emphasis has been given to calculations of carbonyl force constants. Based on the spectroscopic evidences it has been confirmed that these metal carbonyl complexes with the ditertiary phosphine ligand showed cis geometry in their molecular structure.

  19. Combined 1H and 31P MR spectroscopic imaging: impaired energy metabolism in severe carotid stenosis and changes upon treatment.

    PubMed

    Hattingen, E; Lanfermann, H; Menon, S; Neumann-Haefelin, T; de Rochement, R DuMesnil; Stamelou, M; Höglinger, G U; Magerkurth, J; Pilatus, U

    2009-02-01

    To evaluate if combined (1)H and (31)P MR spectroscopic imaging (MRSI) before and after treatment of severe internal carotid artery (ICA) stenosis detects significant changes in energy metabolism in the basal ganglia of both hemispheres. A group of 14 patients with high-grade ICA stenosis and 11 healthy control subjects were examined with 2D (1)H MRSI and 3D (31)P MRSI at 3 T before and after treatment of severe ICA stenosis. Spectroscopic data were processed with LCModel and jMRUI software. Changes of the phosphorylated metabolites, pH, N-acetyl-acetate, creatine and choline-containing compounds prior/post intervention were analyzed and patients' data were compared with that of control subjects. Untreated patients had significantly higher Adenosindiphosphate (ADP) in basal ganglia ipsi- and contralateral to the side of ACI stenosis compared to controls. After treatment, ADP of both hemispheres significantly decreased by approximately 20% compared to the pre-treatment values. Further, significant decreases of phosphorylated metabolites prior/post intervention were found for patients compared to controls. This spectroscopic study reveals that unilateral high-grade ICA stenosis has an effect on cerebral high-energy metabolism of both hemispheres, which is at least partially reversible after treatment. Therefore the restoration of blood flow in high-grade ICA stenosis recovers the impaired energy balance of the brain.

  20. Determination of glucan phosphorylation using heteronuclear 1H, 13C double and 1H, 13C, 31P triple-resonance NMR spectra.

    PubMed

    Schmieder, Peter; Nitschke, Felix; Steup, Martin; Mallow, Keven; Specker, Edgar

    2013-10-01

    Phosphorylation and dephosphorylation of starch and glycogen are important for their physicochemical properties and also their physiological functions. It is therefore desirable to reliably determine the phosphorylation sites. Heteronuclear multidimensional NMR-spectroscopy is in principle a straightforward analytical approach even for complex carbohydrate molecules. With heterogeneous samples from natural sources, however, the task becomes more difficult because a full assignment of the resonances of the carbohydrates is impossible to obtain. Here, we show that the combination of heteronuclear (1) H,(13) C and (1) H,(13) C,(31) P techniques and information derived from spectra of a set of reference compounds can lead to an unambiguous determination of the phosphorylation sites even in heterogeneous samples.

  1. Dynamic structures of intact chicken erythrocyte chromatins as studied by 1H-31P cross-polarization NMR.

    PubMed Central

    Akutsu, H; Nishimoto, S; Kyogoku, Y

    1994-01-01

    The dynamic properties of DNA in intact chicken erythrocyte cells, nuclei, nondigested chromatins, digested soluble chromatins, H1, H5-depleted soluble chromatins and nucleosome cores were investigated by means of single-pulse and 1H-31P cross-polarization NMR. The temperature dependence of the phosphorus chemical shift anisotropy was identical for the former three in the presence of 3 mM MgCl2, suggesting that the local higher order structure is identical for these chromatins. The intrinsic phosphorus chemical shift anisotropy of the nucleosome cores was -159 ppm. The chemical shift anisotropy of DNA in the chromatins can be further averaged by the motion of the linker DNA. The spin-lattice relaxation time in the rotating frame of the proton spins (T1p) of the nondigested chromatins was measured at various locking fields. The result was analyzed on the assumption of the isotropic motion to get a rough value of the correlation time of the motion efficient for the relaxation, which was eventually ascribed to the segmental motion of the linker DNA with restricted amplitude. The 30 nm filament structure induced by NaCl was shown to be dynamically different from that induced by MgCl2. Side-by-side compaction of 30-nm filaments was suggested to be induced in the MgCl2 concentration range higher than 0.3 mM. Biological significance of the dynamic structure was discussed in connection with the results obtained. PMID:7948693

  2. Two configurations of the four-ring birdcage coil for 1H imaging and 1H-decoupled 31P spectroscopy of the human head.

    PubMed

    Murphy-Boesch, J; Srinivasan, R; Carvajal, L; Brown, T R

    1994-02-01

    The four-ring birdcage resonator, a new class of dual-tuned birdcage resonators, is described. We report two configurations of the coil: the low-pass, high-pass (LP-HP) and the low-pass, low-pass (LP-LP), both of which can be operated in dual quadrature mode at 1.5 T. As head coils, both configurations exhibit greatly reduced tuning interactions between frequencies, permitting rapid, noniterative tuning. Compared with single-tuned, two-ring birdcage resonators of similar volume, the sensitivity and transmitter efficiencies of the resonators are better than 85% for the proton frequency and the same to within 5% for the phosphorus frequency. Circuit models have been developed to refine coil tuning and aid the calculation of B1 field contour plots. Both configurations have been used for integrated examinations involving acquisition of high-quality 1H images and 1H-decoupled 31P CSI spectra of the human head. A scaled-down version of the LP-LP configuration has been demonstrated for use with the human calf.

  3. Two Configurations of the Four-Ring Birdcage Coil for 1H Imaging and 1H-Decoupled 31P Spectroscopy of the Human Head

    NASA Astrophysics Data System (ADS)

    Murphyboesch, J.; Srinivasan, R.; Carvajal, L.; Brown, T. R.

    The four-ring birdcage resonator, a new class of dual-tuned birdeage resonators, is described. We report two configurations of the coil: the low-pass, high-pass (LP-HP) and the low-pass, low-pass (LP-LP), both of which can be operated in dual quadrature mode at 1.5 T. As head coils, both configurations exhibit greatly reduced tuning interactions between frequencies, permitting rapid, noniterative tuning. Compared with single-tuned, two-ring birdcage resonators of similar volume, the sensitivity and transmitter efficiencies of the resonators are better than 85% for the proton frequency and the same to within 5% for the phosphorus frequency. Circuit models have been developed to refine coil tuning and aid the calculation of B1 field contour plots. Both configurations have been used for integrated examinations involving acquisition of high-quality 1H images and 1H-decoupled 31P CSI spectra of the human head. A scaled-down version of the LP-LP configuration has been demonstrated for use with the human calf.

  4. Study of stereospecificity of 1H, 13C, 15N and 77Se shielding constants in the configurational isomers of the selenophene-2-carbaldehyde azine by NMR spectroscopy and MP2-GIAO calculations.

    PubMed

    Afonin, Andrei V; Pavlov, Dmitry V; Albanov, Alexander I; Levanova, Ekaterina P; Levkovskaya, Galina G

    2011-11-01

    In the (1)H and (13)C NMR spectra of selenophene-2-carbaldehyde azine, the (1)H-5, (13)C-3 and (13)C-5 signals of the selenophene ring are shifted to higher frequencies, whereas those of the (1)H-1, (13)C-1, (13)C-2 and (13)C-4 are shifted to lower frequencies on going from the EE to ZZ isomer or from the E moiety to the Z moiety of EZ isomer. The (15)N chemical shift is significantly larger in the EE isomer relative to the ZZ isomer and in the E moiety relative to the Z moiety of EZ isomer. A very pronounced difference (60-65 mg/g) between the (77)Se resonance positions is revealed in the studied azine isomers, the (77)Se peak being shifted to higher frequencies in the ZZ isomer and in the Z moiety of EZ isomer. The trends in the changes of the measured chemical shifts are reasonably reproduced by the GIAO calculations at the MP2 level of the (1)H, (13)C, (15)N and (77)Se shielding constants in the energy-favorable conformation with the syn orientation of both selenophene rings relative to the C = N groups. The NBO analysis suggests that such an arrangement of the selenophene rings may take place because of a higher energy of some intramolecular interactions. Copyright © 2011 John Wiley & Sons, Ltd.

  5. Chemical characterization of a prominent phosphomonoester resonance from mammalian brain. 31P and 1H NMR analysis at 4.7 and 14.1 tesla

    NASA Astrophysics Data System (ADS)

    Pettegrew, J. W.; Kopp, S. J.; Dadok, J.; Minshew, N. J.; Feliksik, J. M.; Glonek, T.; Cohen, M. M.

    A prominent 31P NMR resonance at 3.84 ppm in mammalian brain has been identified as ethanolamine phosphate. The identification was based on 1H and 31P NMR findings (including pH titrations) at 4.7 and 14.1 T, as well as thin-layer chromatography studies. We previously incorrectly assigned the 3.84 ppm resonance to ribose-5-phosphate. The incorrect assignment occurred because the two compounds have very similar 31P chemical shifts, and because we did not carefully consider the effects of counter ions and ionic strengths when interpreting the 31P chemical shifts. In separate preliminary studies we have demonstrated ethanolamine phosphate to be high in immature developing brain and in the degenerating brain of Alzheimer's and Huntington's disease patients. Ethanolamine phosphate may therefore serve as a sensitive marker of membrane phospholipid turnover for both in vitro and in vivo31P NMR studies.

  6. Nuclear Magnetic Resonance Identification of Military Nerve Agents and Related Compounds by Two-Dimensional 31P-1H Heteronuclear Overhauser Effect Spectroscopy

    DTIC Science & Technology

    2010-06-01

    IDENTIFICATION OF MILITARY NERVE AGENTS AND RELATED COMPOUNDS BY TWO-DIMENSIONAL 31P-1H HETERONUCLEAR OVERHAUSER EFFECT SPECTROSCOPY Terry J...Agents and 5a. CONTRACT NUMBER Related Compounds by Two-Dimensional Overhauser Effect Spectroscopy 31 P- H Heteronuclear 5b. GRANT NUMBER 5c...heteronuclear Overhauser effect spectroscopy (HOESY) spectrum correlating phosphorus nuclei to their ./-coupled protons. An analogous heteronuclear

  7. [Non-invasive investigation of muscle function using 31P magnetic resonance spectroscopy and 1H MR imaging].

    PubMed

    Bendahan, D; Mattei, J P; Guis, S; Kozak-Ribbens, G; Cozzone, P J

    2006-04-01

    31P MRS and 1H MRI of skeletal muscle have become major new tools allowing a complete non invasive investigation of muscle function both in the clinical setting and in basic research. The comparative analysis of normal and diseased muscle remains a major requirement to further define metabolic events surrounding muscle contraction and the metabolic anomalies underlying pathologies. Also, standardized rest-exercise-recovery protocols for the exploration of muscle metabolism by P-31 MRS in healthy volunteers as well as in patients with intolerance to exercise have been developed. The CRMBM protocol is based on a short-term intense exercise, which is very informative and well accepted by volunteers and patients. Invariant metabolic parameters have been defined to characterize the normal metabolic response to the protocol. Deviations from normality can be directly interpreted in terms of specific pathologies in some favorable cases. This protocol has been applied to more than 4,000 patients and healthy volunteers over a period of 15 years. On the other hand, MRI investigations provide anatomical and functional information from resting and exercising muscle. From a diagnostic point of view, dedicated pulse sequences can be used in order to detect and quantify muscle inflammation, fatty replacement, muscle hyper and hypotrophy. In most cases, MR techniques provide valuable information which has to be processed in conjunction with traditional invasive biochemical, electrophysiological and histoenzymological tests. P-31 MRS has proved particularly useful in the therapeutic follow-up of palliative therapies (coenzyme Q treatment of mitochondriopathies) and in family investigations. It is now an accepted diagnostic tool in the array of tests which are used to characterize muscle disorders in clinical routine. As a research tool, it will keep bringing new information on the physiopathology of muscle diseases in animal models and in humans and should play a role in the

  8. Creatine and cyclocreatine treatment of human colon adenocarcinoma xenografts: 31P and 1H magnetic resonance spectroscopic studies

    PubMed Central

    Kristensen, C A; Askenasy, N; Jain, R K; Koretsky, A P

    1999-01-01

    Creatine (Cr) and cyclocreatine (cyCr) have been shown to inhibit the growth of a variety of human and murine tumours. The purpose of this study was to evaluate the anti-tumour effect of these molecules in relation to drug accumulation, energy metabolism, tumour water accumulation and toxicity. Nude mice carrying a human colon adenocarcinoma (LS174T) with a creatine kinase (CK) activity of 2.12 units mg−1 protein were fed Cr (2.5% or 5%) or cyCr (0.025%, 0.1% or 0.5%) for 2 weeks and compared with controls fed standard diet. Cr concentrations of 2.5% and 5% significantly inhibited tumour growth, as did 0.1% and 0.5% cyCr. In vivo 31P magnetic resonance spectroscopy (MRS) after 2 weeks of treatment showed an increase in [phosphocreatine (PCr)+phosphocyclocreatine (PcyCr)]/nucleoside triphosphate (NTP) with increasing concentrations of dietary Cr and cyCr, without changes in absolute NTP contents. The antiproliferative effect of the substrates of CK was not related to energy deficiency but was associated with acidosis. Intratumoral substrate concentrations (measured by 1H-MRS) of 4.8 μmol g−1 wet weight Cr (mice fed 2.5% Cr) and 6.2 μmol g−1 cyCr (mice fed 0.1% cyCr) induced a similar decrease in growth rate, indicating that both substrates were equally potent in tumour growth inhibition. The best correlant of growth inhibition was the total Cr or (cyCr+Cr) concentrations in the tissue. In vivo, these agents did not induce excessive water accumulation and had no systemic effects on the mice (weight loss, hypoglycaemia) that may have caused growth inhibition. © 1999 Cancer Research Campaign PMID:9888469

  9. 2D 1H- 31P solid-state NMR studies of the dependence of inter-bilayer water dynamics on lipid headgroup structure and membrane peptides

    NASA Astrophysics Data System (ADS)

    Doherty, Tim; Hong, Mei

    2009-01-01

    The dynamics of hydration-water in several phospholipid membranes of different compositions is studied by 2D 1H- 31P heteronuclear correlation NMR under magic-angle spinning. By using a 1H T2 filter before and a 1H mixing-time after the evolution period and 31P detection, inter-bilayer water is selectively detected without resonance overlap from bulk water outside the multilamellar vesicles. Moreover the 1H T2 relaxation time of the inter-bilayer water is measured. Lipid membranes with labile protons either in the lipid headgroup or in sterols exhibit water- 31P correlation peaks while membranes free of exchangeable protons do not, indicating that the mechanism for water-lipid correlation is chemical exchange followed by relayed magnetization transfer to 31P. In the absence of membrane proteins, the inter-bilayer water 1H T2's are several tens of milliseconds. Incorporation of charged membrane peptides shortened this inter-bilayer water T2 significantly. This T2 reduction is attributed to the peptides' exchangeable protons, molecular motion and intermolecular hydrogen bonding, which affect the water dynamics and the chemically relayed magnetization transfer process.

  10. Feasibility of assessing bone matrix and mineral properties in vivo by combined solid-state 1H and 31P MRI

    PubMed Central

    Song, Hee Kwon; Seifert, Alan C.; Li, Cheng; Wehrli, Felix W.

    2017-01-01

    Purpose To develop and evaluate an integrated imaging protocol for bone water and phosphorus quantification in vivo by solid-state 1H and 31P MRI. Materials and methods All studies were HIPAA-compliant and were performed with institutional review board approval and written informed consent. Proton (1H) ultra-short echo-time (UTE) and phosphorus (31P) zero echo-time (ZTE) sequences were designed and implemented on a 3 T clinical MR scanner to quantify bone water and mineral in vivo. The left tibia of ten healthy subjects (including both genders, 49±15 y/o) was examined with a custom-built 1H/31P dual-frequency extremity RF coil. Total bone water (TW), water bound to the collagen matrix (BW) and bone 31P were quantified from MR images with respect to reference samples of known 1H or 31P concentration, and pore water (PW) was subsequently determined from TW and BW. Porosity index (PI) was calculated as the ratio between UTE images acquired at two echo times. MRI parameters were compared with bone density measures obtained by high-resolution peripheral quantitative CT (HR-pQCT). Results The total scan time for the bone water and 31P quantification protocol was about 50 minutes. Average TW, BW, PW and 31P concentrations were 13.99±1.26, 10.39±0.80, 3.34±1.41 mol/L and 7.06±1.53 mol/L for the studied cohort, respectively, in good agreement with previous results conducted ex vivo. Average intra-subject coefficients of variation were 3.47%, 2.60% and 7.50% for TW, BW and PW and 5.60% for 31P. Negative correlations were observed between PW and vBMD (p<0.05) as well as between PI and 31P (p<0.05), while bone mineral content (BMC) estimated from 31P MRI and HR-pQCT were strongly positively correlated (p<0.0001). Conclusion This work demonstrates the feasibility of quantifying bone water and mineral phosphorus in human subjects in a single MRI session with a clinically practical imaging protocol. PMID:28296979

  11. Solid-State 31P and 1H NMR Investigations of Amorphous and Crystalline Calcium Phosphates Grown Biomimetically From a Mesoporous Bioactive Glass

    PubMed Central

    2011-01-01

    By exploiting 1H and 31P magic-angle spinning nuclear magnetic resonance (NMR) spectroscopy, we explore the proton and orthophosphate environments in biomimetic amorphous calcium phosphate (ACP) and hydroxy-apatite (HA), as grown in vitro at the surface of a 10CaO–85SiO2–5P2O5 mesoporous bioactive glass (MBG) in either a simulated body fluid or buffered water. Transmission electron microscopy confirmed the presence of a calcium phosphate layer comprising nanocrystalline HA. Two-dimensional 1H–31P heteronuclear correlation NMR established predominantly 1H2O↔31PO43– and O1H↔31PO43– contacts in the amorphous and crystalline component, respectively, of the MBG surface-layer; these two pairs exhibit distinctly different 1H→31P cross-polarization dynamics, revealing a twice as large squared effective 1H–31P dipolar coupling constant in ACP compared with HA. These respective observations are mirrored in synthetic (well-crystalline) HA, and the amorphous calcium orthophosphate (CaP) clusters that are present in the pristine MBG pore walls: besides highlighting very similar local 1H and 31P environments in synthetic and biomimetic HA, our findings evidence closely related NMR characteristics, and thereby similar local structures, of the CaP clusters in the pristine MBG relative to biomimetic ACP. PMID:22132242

  12. In vivo absolute quantification for mouse muscle metabolites using an inductively coupled synthetic signal injection method and newly developed 1H/31P dual tuned probe

    PubMed Central

    Lee, Donghoon; Marro, Kenneth; Mathis, Mark; Shankland, Eric; Hayes, Cecil

    2013-01-01

    Purpose To obtain robust estimates of 31P metabolite content in mouse skeletal muscles using our recently developed MR absolute quantification method and a custom-built 1H/31P dual tuned radiofrequency (RF) coil optimized for mouse leg. Materials and Methods We designed and fabricated a probe consisting of two dual tuned 1H/31P solenoid coils: one leg was inserted to each solenoid. The mouse leg volume coil was incorporated with injector coils for MR absolute quantification. The absolute quantification method uses a synthetic reference signal injection approach and solves several challenges in MR absolute quantification including changes of coil loading and receiver gains. Results The 1H/31P dual tuned probe was composed of two separate solenoid coils, one for each leg, to increase coil filling factors and signal-to-noise ratio. Each solenoid was equipped with a second coil to allow injection of reference signals. 31P metabolite concentrations determined for normal mice were well within the expected range reported in the literature. Conclusion We developed an RF probe and an absolute quantification approach adapted for mouse skeletal muscle. PMID:24464912

  13. {sup 1}H and {sup 31}P nuclear magnetic resonance study of proton-irradiated KH{sub 2}PO{sub 4}

    SciTech Connect

    Kim, Se-Hun; Lee, Kyu Won; Oh, B. H.; Lee, Cheol Eui; Hong, K. S.

    2007-11-01

    We have studied the microscopic structure and dynamics in a proton-irradiated KH{sub 2}PO{sub 4} single crystal. Our {sup 1}H and {sup 31}P nuclear magnetic resonance measurements indicate that proton irradiation gives rise to a decrease in the local dipolar order of the rigid lattice protons and an increase in interstitial protons as well as structural distortion of the PO{sub 4} tetrahedra.

  14. Headgroup conformation and lipid--cholesterol association in phosphatidylcholine vesicles: a 31P(1H) nuclear Overhauser effect study.

    PubMed Central

    Yeagle, P L; Hutton, W C; Huang, C H; Martin, R B

    1975-01-01

    The nuclear Overhauser effect has been observed in the nuclear magnetic resonance spectra of 31P. The information content of the nuclear Overhauser effect has been applied to the structure and dynamic properties of phosphatidylcholine vesicles. In the vesicles only 1/3 of the theoretical maximum nuclear Overhauser effect enhancement is observed. This result is accounted for by dipolar interactions between the N-methyl protons and the phosphate of phosphatidylcholine, and a correlation time for internal motion of 1.4 X 10(-9) sec. Addition of up to 30% cholesterol does not change the nuclear Overhauser effect enhancement or spin-lattice relaxation time of the vesicles. It is argued that the OH group of cholesterol is hydrogen bonded to the ester carbonyl oxygen of the phosphatidylcholine molecules. PMID:1059134

  15. A form-fitted three channel (31) P, two channel (1) H transceiver coil array for calf muscle studies at 7 T.

    PubMed

    Goluch, Sigrun; Kuehne, Andre; Meyerspeer, Martin; Kriegl, Roberta; Schmid, Albrecht I; Fiedler, Georg B; Herrmann, Tim; Mallow, Johannes; Hong, Suk-Min; Cho, Zang-Hee; Bernarding, Johannes; Moser, Ewald; Laistler, Elmar

    2015-06-01

    To enhance sensitivity and coverage for calf muscle studies, a novel, form-fitted, three-channel phosphorus-31 ((31) P), two-channel proton ((1) H) transceiver coil array for 7 T MR imaging and spectroscopy is presented. Electromagnetic simulations employing individually generated voxel models were performed to design a coil array for studying nonpathological muscle metabolism. Static phase combinations of the coil elements' transmit fields were optimized based on homogeneity and efficiency for several voxel models. The best-performing design was built and tested both on phantoms and in vivo. Simulations revealed that a shared conductor array for (31) P provides more robust interelement decoupling and better homogeneity than an overlap array in this configuration. A static B1 (+) shim setting that suited various calf anatomies was identified and implemented. Simulations showed that the (31) P array provides signal-to-noise ratio (SNR) benefits over a single loop and a birdcage coil of equal radius by factors of 3.2 and 2.6 in the gastrocnemius and by 2.5 and 2.0 in the soleus muscle. The performance of the coil in terms of B1 (+) and achievable SNR allows for spatially localized dynamic (31) P spectroscopy studies in the human calf. The associated higher specificity with respect to nonlocalized measurements permits distinguishing the functional responses of different muscles. © 2014 Wiley Periodicals, Inc.

  16. Phosphatidylcholine and cholesteryl esters identify the infiltrating behaviour of a clear cell renal carcinoma: 1H, 13C and 31P MRS evidence.

    PubMed

    Tugnoli, V; Poerio, A; Tosi, M R

    2004-08-01

    This study presents a multinuclear (1H, 13C and 31P) magnetic resonance spectroscopy characterization of the total lipid fraction extracted from different regions of a human kidney affected by a clear cell renal carcinoma. It was thus possible to demonstrate that cholesteryl esters and phosphatidylcholine are markers of the tumor infiltration, histologically confirmed, in the kidney medulla. The tumor tissue contains twice the amount of phosphatidylcholine compared to normal cortex. The results appear relevant in light of new clinical applications based on the biochemical composition of human tissues.

  17. Quantitative (31)P NMR spectroscopy and (1)H MRI measurements of bone mineral and matrix density differentiate metabolic bone diseases in rat models.

    PubMed

    Cao, Haihui; Nazarian, Ara; Ackerman, Jerome L; Snyder, Brian D; Rosenberg, Andrew E; Nazarian, Rosalynn M; Hrovat, Mirko I; Dai, Guangping; Mintzopoulos, Dionyssios; Wu, Yaotang

    2010-06-01

    In this study, bone mineral density (BMD) of normal (CON), ovariectomized (OVX), and partially nephrectomized (NFR) rats was measured by (31)P NMR spectroscopy; bone matrix density was measured by (1)H water- and fat-suppressed projection imaging (WASPI); and the extent of bone mineralization (EBM) was obtained by the ratio of BMD/bone matrix density. The capability of these MR methods to distinguish the bone composition of the CON, OVX, and NFR groups was evaluated against chemical analysis (gravimetry). For cortical bone specimens, BMD of the CON and OVX groups was not significantly different; BMD of the NFR group was 22.1% (by (31)P NMR) and 17.5% (by gravimetry) lower than CON. For trabecular bone specimens, BMD of the OVX group was 40.5% (by (31)P NMR) and 24.6% (by gravimetry) lower than CON; BMD of the NFR group was 26.8% (by (31)P NMR) and 21.5% (by gravimetry) lower than CON. No significant change of cortical bone matrix density between CON and OVX was observed by WASPI or gravimetry; NFR cortical bone matrix density was 10.3% (by WASPI) and 13.9% (by gravimetry) lower than CON. OVX trabecular bone matrix density was 38.0% (by WASPI) and 30.8% (by gravimetry) lower than CON, while no significant change in NFR trabecular bone matrix density was observed by either method. The EBMs of OVX cortical and trabecular specimens were slightly higher than CON but not significantly different from CON. Importantly, EBMs of NFR cortical and trabecular specimens were 12.4% and 26.3% lower than CON by (31)P NMR/WASPI, respectively, and 4.0% and 11.9% lower by gravimetry. Histopathology showed evidence of osteoporosis in the OVX group and severe secondary hyperparathyroidism (renal osteodystrophy) in the NFR group. These results demonstrate that the combined (31)P NMR/WASPI method is capable of discerning the difference in EBM between animals with osteoporosis and those with impaired bone mineralization.

  18. In vivo (1)H MRS and (31)P MRSI of the response to cyclocreatine in transgenic mouse liver expressing creatine kinase.

    PubMed

    Cui, Min-Hui; Jayalakshmi, Kamaiah; Liu, Laibin; Guha, Chandan; Branch, Craig A

    2015-12-01

    Hepatocyte transplantation has been explored as a therapeutic alternative to liver transplantation, but a means to monitor the success of the procedure is lacking. Published findings support the use of in vivo (31)P MRSI of creatine kinase (CK)-expressing hepatocytes to monitor proliferation of implanted hepatocytes. Phosphocreatine tissue level depends upon creatine (Cr) input to the CK enzyme reaction, but Cr measurement by (1)H MRS suffers from low signal-to-noise ratio (SNR). We examine the possibility of using the Cr analog cyclocreatine (CCr, a substrate for CK), which is quickly phosphorylated to phosphocyclocreatine (PCCr), as a higher SNR alternative to Cr. (1)H MRS and (31)P MRSI were employed to measure the effect of incremental supplementation of CCr upon PCCr, γ-ATP, pH and Pi /ATP in the liver of transgenic mice expressing the BB isoform of CK (CKBB) in hepatocytes. Water supplementation with 0.1% CCr led to a peak total PCCr level of 17.15 ± 1.07 mmol/kg wet weight by 6 weeks, while adding 1.0% CCr led to a stable PCCr liver level of 18.12 ± 3.91 mmol/kg by the fourth day of feeding. PCCr was positively correlated with CCr, and ATP concentration and pH declined with increasing PCCr. Feeding with 1% CCr in water induced an apparent saturated level of PCCr, suggesting that CCr quantization may not be necessary for quantifying expression of CK in mice. These findings support the possibility of using (31)P MRS to noninvasively monitor hepatocyte transplant success with CK-expressing hepatocytes.

  19. Certified Reference Material for Use in (1)H, (31)P, and (19)F Quantitative NMR, Ensuring Traceability to the International System of Units.

    PubMed

    Rigger, Romana; Rück, Alexander; Hellriegel, Christine; Sauermoser, Robert; Morf, Fabienne; Breitruck, KathrinBreitruck; Obkircher, Markus

    2017-09-01

    In recent years, quantitative NMR (qNMR) spectroscopy has become one of the most important tools for content determination of organic substances and quantitative evaluation of impurities. Using Certified Reference Materials (CRMs) as internal or external standards, the extensively used qNMR method can be applied for purity determination, including unbroken traceability to the International System of Units (SI). The implementation of qNMR toward new application fields, e.g., metabolomics, environmental analysis, and physiological pathway studies, brings along more complex molecules and systems, thus making use of 1H qNMR challenging. A smart workaround is possible by the use of other NMR active nuclei, namely 31P and 19F. This article presents the development of three classes of qNMR CRMs based on different NMR active nuclei (1H, 31P, and 19F), and the corresponding approaches to establish traceability to the SI through primary CRMs from the National Institute of Standards and Technology and the National Metrology Institute of Japan. These TraceCERT® qNMR CRMs are produced under ISO/IEC 17025 and ISO Guide 34 using high-performance qNMR.

  20. Computational and experimental optimization of a double-tuned (1)H/(31)P four-ring birdcage head coil for MRS at 3T.

    PubMed

    Duan, Yunsuo; Peterson, Bradley S; Liu, Feng; Brown, Truman R; Ibrahim, Tamer S; Kangarlu, Alayar

    2009-01-01

    To optimize the homogeneity and efficiency of the B(1) magnetic field of a four-ring birdcage head coil that is double-tuned at the Larmor frequencies of both (31)P and (1)H and optimized to acquire magnetic resonance spectroscopy (MRS) data at 3T for the study of infants. We developed a finite difference time domain (FDTD) tool in-house to iteratively compute and seek the range of geometric and electromagnetic parameters of a dual-tuned, four-ring birdcage coil that would produce the desired resonance patterns, optimize homogeneity of the B(1)-field, and maximize efficiency of the coil. To demonstrate the validity of our computational results, we constructed three RF coils: one dual-tuned coil that was based on the calculated optimized parameters and two single-tuned coils that had dimensions similar to those of the dual-tuned coil, but tuned at the Larmor frequencies of both (31)P and (1)H, respectively. We then tested and compared the performances of the dual-tuned coil and single-tuned coils at both of these frequencies. We found that a dual-tuned, four-ring birdcage coil with a diameter of 180 mm, an inner birdcage length of 100-300 mm, and an outer birdcage length of 25-100 mm produces the desired resonance patterns. For the use of this coil with human infants, optimization of the homogeneity of the B(1) field, combined with improved coil efficiency, yielded a dual-tuned birdcage coil with diameter of 180mm, an inner birdcage length of 150 mm, an outer birdcage length of 25 mm, and corresponding inner and outer capacitances of 17.2 pF and 7.6 pF, respectively. The experimental results from a constructed coil having the same parameters with the modeled coil agreed well with the computational results from the modeled coil. This optimized design overcame the deficiencies of existing dual-tuned, four-ring birdcage coils. The homogeneity and efficiency of the B(1) field for (31)P/(1)H dual-tuned, four-ring birdcage coils can be optimized well using our FDTD tool

  1. Evaluation of the RF field uniformity of a double-tuned 31P/1H birdcage RF coil for spin-echo MRI/MRS of the diabetic foot.

    PubMed

    Greenman, Robert L; Rakow-Penner, Rebecca

    2005-09-01

    To evaluate the B1 field uniformity of a double-tuned birdcage coil designed for (31)P/(1)H MRI/MRS spin-echo (SE) imaging of the metatarsal head region of the foot in neuropathic diabetic patients. A low-pass double-tuned (31)P/(1)H RF birdcage coil was constructed to fit over the adult forefoot. Flip angle (FA) maps were created from B1 data acquired at the 3T (31)P (four normal subjects) and (1)H (five normal subjects) frequencies. T2-weighted (T2-W) (1)H images, (31)P rapid acquisition with relaxation enhancement (RARE) images, and composite SE pulse CSI data were acquired to demonstrate the uniformity of the resulting images and data. The means and standard deviations (SDs) of the range of FAs across the feet of the volunteer subjects indicated good uniformity (the maximum coefficients of variation (CVs) for all of the (31)P and (1)H FA maps were 7.6% and 7.3%, respectively). The FA values across the metatarsal head region indicated a maximum signal intensity variation of +/-3% in a RARE image acquired using an echo train length of 32. A (31)P/(1)H birdcage coil constructed for MRI/MRS studies of the human forefoot provided sufficient signal uniformity of SE data to facilitate accurate (31)P concentration measurements in muscle. (c) 2005 Wiley-Liss, Inc.

  2. (1)H and (31)P magnetic resonance spectroscopy in a rat model of chronic hepatic encephalopathy: in vivo longitudinal measurements of brain energy metabolism.

    PubMed

    Rackayova, Veronika; Braissant, Olivier; McLin, Valérie A; Berset, Corina; Lanz, Bernard; Cudalbu, Cristina

    2016-12-01

    Chronic liver disease (CLD) leads to a spectrum of neuropsychiatric disorders named hepatic encephalopathy (HE). Even though brain energy metabolism is believed to be altered in chronic HE, few studies have explored energy metabolism in CLD-induced HE, and their findings were inconsistent. The aim of this study was to characterize for the first time in vivo and longitudinally brain metabolic changes in a rat model of CLD-induced HE with a focus on energy metabolism, using the methodological advantages of high field proton and phosphorus Magnetic Resonance Spectroscopy ((1)H- and (31)P-MRS). Wistar rats were bile duct ligated (BDL) and studied before BDL and at post-operative weeks 4 and 8. Glutamine increased linearly over time (+146 %) together with plasma ammonium (+159 %). As a compensatory effect, other brain osmolytes decreased: myo-inositol (-36 %), followed by total choline and creatine. A decrease in the neurotransmitters glutamate (-17 %) and aspartate (-28 %) was measured only at week 8, while no significant changes were observed for lactate and phosphocreatine. Among the other energy metabolites measured by (31)P-MRS, we observed a non-significant decrease in ATP together with a significant decrease in ADP (-28 %), but only at week 8 after ligation. Finally, brain glutamine showed the strongest correlations with changes in other brain metabolites, indicating its importance in type C HE. In conclusion, mild alterations in some metabolites involved in energy metabolism were observed but only at the end stage of the disease when edema and neurological changes are already present. Therefore, our data indicate that impaired energy metabolism is not one of the major causes of early HE symptoms in the established model of type C HE.

  3. 1H and 31P nuclear magnetic resonance and kinetic studies of the active site structure of chloroplast CF1 ATP synthase.

    PubMed

    Devlin, C C; Grisham, C M

    1990-07-03

    The interaction of nucleotides and nucleotide analogues and their metal complexes with Mn2+ bound to both the latent and dithiothreitol-activated CF1 ATP synthase has been examined by means of steady-state kinetics, water proton relaxation rate (PRR) measurements, and 1H and 31P nuclear relaxation measurements. Titration of both the latent and activated Mn(2+)-CF1 complexes with ATP, ADP, Pi, Co(NH3)4ATP, Co(NH3)4ADP, and Co(NH3)4AMPPCP leads to increases in the water relaxation enhancement, consistent with enhanced metal binding and a high ternary complex enhancement. Steady-state kinetic studies are consistent with competitive inhibition of CF1 by Co(NH3)4AMPPCP with respect to CaATP. The data are consistent with a Ki for Co(NH3)4AMPPCP of 650 microM, in good agreement with a previous Ki of 724 microM for Cr(H2O)4ATP [Frasch, W., & Selman, B. (1982) Biochemistry 21, 3636-3643], and a best fit KD of 209 microM from the water PRR measurements. 1H and 31P nuclear relaxation measurements in solutions of CF1 and Co(NH3)4AMPPCP were used to determine the conformation of the bound substrate analogue and the arrangement with respect to this structure of high- and low-affinity sites for Mn2+. The bound nucleotide analogue adopts a bent conformation, with the low-affinity Mn2+ site situated between the adenine and triphosphate moieties and the high-affinity metal site located on the far side of the triphosphate chain. The low-affinity metal forms a distorted inner-sphere complex with the beta-P and gamma-P of the substrate. The distances from Mn2+ to the triphosphate chain are too large for first coordination sphere complexes but are appropriate for second-sphere complexes involving, for example, intervening hydrogen-bonded water molecules or residues from the protein.

  4. sup 1 H and sup 31 P nuclear magnetic resonance and kinetic studies of the active site structure of chloroplast CF sub 1 ATP synthase

    SciTech Connect

    Devlin, C.C.; Grisham, C.M. )

    1990-07-03

    The interaction of nucleotides and nucleotide analogues and their complexes with Mn{sup 2+} bound to both the latent and dithiothreitol-activated CF{sub 1} ATP synthase has been examined by means of steady-state kinetics, water proton relaxation rate (PRR) measurements, and {sup 1}H and {sup 31}P nuclear relaxation measurements. Titration of both the latent and activated Mn{sup 2+}-CF{sub 1} complexes with ATP, ADP, P{sub i}, Co(NH{sub 3}){sub 4}ATP, Co(NH{sub 3}){sub 4}ADP, and Co(NH{sub 3}){sub 4}AMPPCP leads to increases in the water relaxation enhancement, consistent with enhanced metal binding and a high ternary complex enhancement. Steady-state kinetic studies are consistent with competitive inhibition of CF{sub 1} by Co(NH{sub 3}){sub 4}AMPPCP with respect to CaATP. {sup 1}H and {sup 31}P nuclear relaxation measurements in solutions of CF{sub 1} and Co(NH{sub 3}){sub 4}AMPPCP were used to determine the conformation of the bound substrate analogue and the arrangement with respect to this structure of high- and low-affinity sites for Mn{sup 2+}. The bound nucleotide analogue adopts a bent conformation, with the low-affinity sites for Mn{sup 2+}. The bound nucleotide analogue adopts a bent conformation, with the low-affinity Mn{sup 2+} site situated between the adenine and triphosphate moieties and the high-affinity metal site located on the far side of the triphosphate chain. The low-affinity metal forms a distorted inner-sphere complex with the {beta}-P and {gamma}-P of the substrate. The distances from Mn{sup 2+} to the triphosphate chain are too large for first coordination sphere complexes but are appropriate for second-sphere complexes involving, for example, intervening hydrogen-bonded water molecules or residues from the protein.

  5. Wheat germ 5S ribosomal RNA common arm fragment conformations observed by sup 1 H and sup 31 P nuclear magnetic resonance spectroscopy

    SciTech Connect

    Wu, Jiejun; Marshall, A.G. )

    1990-02-20

    The nonexchangeable protons of the common arm fragment of wheat germ (Triticum aestivum) ribosomal 5S RNA have been observed by means of high-resolution 500-MHz {sup 1}H NMR spectroscopy in D{sub 2}O solution. Although NMR studies on the exchangeable protons support the presence of two distinct solution structures of the common arm fragment (and of the same base-paired segment in intact 5S rRNA), only a single conformation is manifested in the {sup 1}H NMR behavior of all of the H6 and H5 pyrimidine and most of the H8/H2 purine protons under the same salt conditions. The nonexchangeable protons near the base-paired helix have been assigned by a sequential strategy. Conformational features such as the presence of a cytidine-uridine (C{center dot}U) pair at the loop-helix junction and base stacking into the hairpin loop are evaluated from nuclear Overhauser enhancement spectroscopy (NOESY) data. Double-quantum filtered correlation spectroscopy (DQF-COSY) experiments show that most of the 26 riboses are in the C3{prime}-endo conformation. Finally, backbone conformational changes induced by Mg{sup 2+} and heating have been monitored by {sup 31}P NMR spectroscopy. The results show that the common arm RNA segment can assume two conformations which produce distinguishably different NMR environments at the base-pair hydrogen-bond imino protons but not at nonexchangeable base or ribose proton or backbone phosphate sites.

  6. Modeling sickle cell vasoocculsion in the rat leg: Quantification of trapped sickle cells and correlation with sup 31 P metabolic and sup 1 H magnetic resonance imaging changes

    SciTech Connect

    Fabry, M.E.; Rajanayagam, V.; Fine, E.; Holland, S.; Gore, J.C.; Nagel, R.L.; Kaul, D.K. )

    1989-05-01

    The authors have developed an animal model to elucidate the acute effects of perfusion abnormalities on muscle metabolism induced by different density-defined classes of erythrocytes isolated from sickle cell anemia patients. Technetium-99m ({sup 99m}Tc)-labeled, saline-washed normal (AA), homozygous sickle (SS), or high-density SS (SS4) erythrocytes were injected into the femoral artery of the rat and quantitative {sup 99m}Tc imaging, {sup 31}P magnetic resonance spectroscopy by surface coil at 2 teslas, and {sup 1}H magnetic resonance imaging at 0.15 tesla were performed. Between 5 and 25 {mu}l of SS4 cells was trapped in the microcirculation of the thigh. In contrast, fewer SS discocytes (SS2) or AA cells were trapped. After injection of SS4 cells an initial increase in inorganic phosphate was observed in the region of the thigh served by the femoral artery, intracellular pH decreased, and subsequently the proton relaxation time T{sub 1} reached a broad maximum at 18-28 hr. When T{sub 1} obtained at this time was plotted against the volume of cells trapped, an increase of T{sub 1} over the control value of 411 {plus minus} 48 msec was found that was proportional to the number of cells trapped. They conclude that the densest SS cells are most effective at producing vasoocclusion. The extent of the change detected by {sup 1}H magnetic resonance imaging is dependent on the amount of cells trapped in the microcirculation and the magnitude of the initial increase of inorganic phosphate.

  7. Geographical characterization of greek virgin olive oils (cv. Koroneiki) using 1H and 31P NMR fingerprinting with canonical discriminant analysis and classification binary trees.

    PubMed

    Petrakis, Panos V; Agiomyrgianaki, Alexia; Christophoridou, Stella; Spyros, Apostolos; Dais, Photis

    2008-05-14

    This work deals with the prediction of the geographical origin of monovarietal virgin olive oil (cv. Koroneiki) samples from three regions of southern Greece, namely, Peloponnesus, Crete, and Zakynthos, and collected in five harvesting years (2001-2006). All samples were chemically analyzed by means of 1H and 31P NMR spectroscopy and characterized according to their content in fatty acids, phenolics, diacylglycerols, total free sterols, free acidity, and iodine number. Biostatistical analysis showed that the fruiting pattern of the olive tree complicates the geographical separation of oil samples and the selection of significant chemical compounds. In this way the inclusion of the harvesting year improved the classification of samples, but increased the dimensionality of the data. Discriminant analysis showed that the geographical prediction at the level of three regions is very high (87%) and becomes (74%) when we pass to the thinner level of six sites (Chania, Sitia, and Heraklion in Crete; Lakonia and Messinia in Peloponnesus; Zakynthos). The use of classification and binary trees made possible the construction of a geographical prediction algorithm for unknown samples in a self-improvement fashion, which can be readily extended to other varieties and areas.

  8. Bevacizumab impairs oxidative energy metabolism and shows antitumoral effects in recurrent glioblastomas: a 31P/1H MRSI and quantitative magnetic resonance imaging study

    PubMed Central

    Hattingen, Elke; Jurcoane, Alina; Bähr, Oliver; Rieger, Johannes; Magerkurth, Jörg; Anti, Sandra; Steinbach, Joachim P.; Pilatus, Ulrich

    2011-01-01

    Bevacizumab shows unprecedented rates of response in recurrent glioblastomas (GBM), but the detailed mechanisms are still unclear. We employed in vivo magnetic resonance spectroscopic imaging (MRSI) and quantitative magnetic resonance imaging to investigate whether bevacizumab alters oxygen and energy metabolism and whether this effect has antitumoral activity in recurrent GBM. 31P and 1H MRSI, apparent diffusion coefficient (ADC), and high-resolution T2 and T2′ mapping (indirect marker of oxygen extraction) were investigated in 16 patients with recurrent GBM at 3 Tesla before and 1.5–2 months after initiation of therapy with bevacizumab. Changes of metabolite concentrations and of the quantitative values in the tumor and normal appearing brain tissue were calculated. The Wilcoxon signed-ranks test was used to evaluate differences for tumor/edema versus control as well as changes before versus after commencement of therapy. Survival analyses were performed for significant parameters. Tumor T2′, pH, ADC, and T2 decreased significantly in patients responding to bevacizumab therapy (n = 10). Patients with at least 25% T2′ decrease during treatment showed longer progression-free and overall survival durations. Levels of high-energy metabolites were lower at baseline; these persisted under therapy. Glycerophosphoethanolamine as catabolic phospholipid metabolite increased in responders. The MRSI data support the hypothesis that bevacizumab induces relative tumor hypoxia (T2′ decrease) and affects energy homeostasis in recurrent GBM, suggesting that bevacizumab impairs vascular function. The antiangiogenic effect of bevacizumab is predictive of better outcome and seems to induce antitumoral activity in the responding GBMs. PMID:21890539

  9. Bevacizumab impairs oxidative energy metabolism and shows antitumoral effects in recurrent glioblastomas: a 31P/1H MRSI and quantitative magnetic resonance imaging study.

    PubMed

    Hattingen, Elke; Jurcoane, Alina; Bähr, Oliver; Rieger, Johannes; Magerkurth, Jörg; Anti, Sandra; Steinbach, Joachim P; Pilatus, Ulrich

    2011-12-01

    Bevacizumab shows unprecedented rates of response in recurrent glioblastomas (GBM), but the detailed mechanisms are still unclear. We employed in vivo magnetic resonance spectroscopic imaging (MRSI) and quantitative magnetic resonance imaging to investigate whether bevacizumab alters oxygen and energy metabolism and whether this effect has antitumoral activity in recurrent GBM. (31)P and (1)H MRSI, apparent diffusion coefficient (ADC), and high-resolution T2 and T2' mapping (indirect marker of oxygen extraction) were investigated in 16 patients with recurrent GBM at 3 Tesla before and 1.5-2 months after initiation of therapy with bevacizumab. Changes of metabolite concentrations and of the quantitative values in the tumor and normal appearing brain tissue were calculated. The Wilcoxon signed-ranks test was used to evaluate differences for tumor/edema versus control as well as changes before versus after commencement of therapy. Survival analyses were performed for significant parameters. Tumor T2', pH, ADC, and T2 decreased significantly in patients responding to bevacizumab therapy (n = 10). Patients with at least 25% T2' decrease during treatment showed longer progression-free and overall survival durations. Levels of high-energy metabolites were lower at baseline; these persisted under therapy. Glycerophosphoethanolamine as catabolic phospholipid metabolite increased in responders. The MRSI data support the hypothesis that bevacizumab induces relative tumor hypoxia (T2' decrease) and affects energy homeostasis in recurrent GBM, suggesting that bevacizumab impairs vascular function. The antiangiogenic effect of bevacizumab is predictive of better outcome and seems to induce antitumoral activity in the responding GBMs.

  10. Monitoring biodegradation of poly(butylene sebacate) by Gel Permeation Chromatography, (1)H-NMR and (31)P-NMR techniques.

    PubMed

    Siotto, Michela; Zoia, Luca; Tosin, Maurizio; Degli Innocenti, Francesco; Orlandi, Marco; Mezzanotte, Valeria

    2013-02-15

    The increasing use of new generation plastics has been accompanied by the development of standard methods for studying their biodegradability. Generally, test methods are based on the measurement of CO(2) production, i.e. the mineralization degree of the tested materials. However, in order to describe the biodegradation process, the determination of the residual amount of tested material which remains in the environment and its chemical characterization can be very important. In this study, the biodegradation in soil of a model polyester (poly(butylene sebacate)) was monitored. Gel Permeation Chromatography and Nuclear Magnetic Resonance ((31)P-NMR and (1)H-NMR) were used in order to obtain information about the polyester structure and the possible by-products that can be found in soil during and at the end of the incubation. The polyester mineralization (i.e. the CO(2) production) was tested according to ASTM 5988 standard method for 245 days. When the polyester mineralization was about 21% and 37% (after 78 and 140 days of incubation) and at the end of the process (63% of mineralization, 100% if compared to the cellulose used as reference material), the soil was extracted with chloroform (solvent of the tested substance) and the extracts were analyzed using GPC and NMR acquisitions. The analytical acquisitions showed high molecular weight polyester in soil during the incubation (78 and 140 days): the polyester concentration decreased but its structure remained almost the same with a slow decreasing in molecular weight. At the end of the test (245 days) no film of the polyester could be extracted from the soil: NMR acquisitions and GPC analyses of the extracts suggested a strong degraded structure of the residual polyester. Even if at the end of the process only 63% of carbon had been lost by mineralization, the whole of the added polyester seems to have disappeared after about eight months of incubation, suggesting substantial biomass formation. Copyright © 2012

  11. 31P and 1H MRS of DB-1 Melanoma Xenografts: Lonidamine Selectively Decreases Tumor Intracellular pH and Energy Status and Sensitizes Tumors to Melphalan

    PubMed Central

    Nath, Kavindra; Nelson, David S.; Ho, Andrew; Lee, Seung-Cheol; Darpolor, Moses M.; Pickup, Stephen; Zhou, Rong; Heitjan, Daniel F.; Leeper, Dennis B.; Glickson, Jerry D.

    2012-01-01

    In vivo 31P MRS demonstrates that human melanoma xenografts in immunosuppressed mice treated with lonidamine (LND, 100 mg/kg, i.p.) exhibit a decrease in intracellular pH (pHi) from 6.90 ± 0.05 to 6.33 ± 0.10 (p < 0.001), a slight decrease in extracellular pH (pHe) from 7.00 ± 0.04 to 6.80 ± 0.07 (p > 0.05), and a monotonic decline in bioenergetics (NTP/Pi) by 66.8 ± 5.7% (p < 0.001) relative to the baseline level. Both bioenergetics and pHi decreases were sustained for at least 3 hr following LND treatment. Liver exhibited a transient intracellular acidification by 0.2 ± 0.1 pH units (p > 0.05) at 20 min post-LND with no significant change in pHe and a small transient decrease in bioenergetics, 32.9 ± 10.6 % (p > 0.05), at 40 min post-LND. No changes in pHi or ATP/Pi were detected in the brain (pHi, bioenergetics; p > 0.1) or skeletal muscle (pHi, pHe, bioenergetics; p > 0.1) for at least 120 min post-LND. Steady-state tumor lactate monitored by 1H MRS with a selective multiquantum pulse sequence with Hadamard localization increased ~3-fold (p = 0.009). Treatment with LND increased systemic melanoma response to melphalan (LPAM; 7.5 mg/kg, i.v.) producing a growth delay of 19.9 ± 2.0 d (tumor doubling time = 6.15 ± 0.31d, log10 cell-kill = 0.975 ± 0.110, cell-kill = 89.4 ± 2.2%) compared to LND alone of 1.1 ± 0.1 d and LPAM alone of 4.0 ± 0.0 d. The study demonstrates that the effects of LND on tumor pHi and bioenergetics may sensitize melanoma to pH-dependent therapeutics such as chemotherapy with alkylating agents or hyperthermia. PMID:22745015

  12. A chelate-stabilized ruthenium(sigma-pyrrolato) complex: resolving ambiguities in nuclearity and coordination geometry through 1H PGSE and 31P solid-state NMR studies.

    PubMed

    Foucault, Heather M; Bryce, David L; Fogg, Deryn E

    2006-12-11

    Reaction of RuCl2(PPh3)3 with LiNN' (NN' = 2-[(2,6-diisopropylphenyl)imino]pyrrolide) affords a single product, with the empirical formula RuCl[(2,6-iPr2C6H3)N=CHC4H3N](PPh3)2. We identify this species as a sigma-pyrrolato complex, [Ru(NN')(PPh3)2]2(mu-Cl)2 (3b), rather than mononuclear RuCl(NN')(PPh3)2 (3a), on the basis of detailed 1D and 2D NMR characterization in solution and in the solid state. Retention of the chelating, sigma-bound iminopyrrolato unit within 3b, despite the presence of labile (dative) chloride and PPh3 donors, indicates that the chelate effect is sufficient to inhibit sigma --> pi isomerization of 3b to a piano-stool, pi-pyrrolato structure. 2D COSY, SECSY, and J-resolved solid-state 31P NMR experiments confirm that the PPh3 ligands on each metal center are magnetically and crystallographically inequivalent, and 31P CP/MAS NMR experiments reveal the largest 99Ru-31P spin-spin coupling constant (1J(99Ru,31P) = 244 +/- 20 Hz) yet measured. Finally, 31P dipolar-chemical shift spectroscopy is applied to determine benchmark phosphorus chemical shift tensors for phosphine ligands in hexacoordinate ruthenium complexes.

  13. Hepatic lipid profiling of deer mice fed ethanol using {sup 1}H and {sup 31}P NMR spectroscopy: A dose-dependent subchronic study

    SciTech Connect

    Fernando, Harshica; Bhopale, Kamlesh K.; Boor, Paul J.; Ansari, G.A. Shakeel; Kaphalia, Bhupendra S.

    2012-11-01

    Chronic alcohol abuse is a 2nd major cause of liver disease resulting in significant morbidity and mortality. Alcoholic liver disease (ALD) is characterized by a wide spectrum of pathologies starting from fat accumulation (steatosis) in early reversible stage to inflammation with or without fibrosis and cirrhosis in later irreversible stages. Previously, we reported significant steatosis in the livers of hepatic alcohol dehydrogenase (ADH)-deficient (ADH{sup −}) vs. hepatic ADH-normal (ADH{sup +}) deer mice fed 4% ethanol daily for 2 months [Bhopale et al., 2006, Alcohol 39, 179–188]. However, ADH{sup −} deer mice fed 4% ethanol also showed a significant mortality. Therefore, a dose-dependent study was conducted to understand the mechanism and identify lipid(s) involved in the development of ethanol-induced fatty liver. ADH{sup −} and ADH{sup +} deer mice fed 1, 2 or 3.5% ethanol daily for 2 months and fatty infiltration in the livers were evaluated by histology and by measuring dry weights of extracted lipids. Lipid metabolomic changes in extracted lipids were determined by proton ({sup 1}H) and {sup 31}phosphorus ({sup 31}P) nuclear magnetic resonance (NMR) spectroscopy. The NMR data was analyzed by hierarchical clustering (HC) and principle component analysis (PCA) for pattern recognition. Extensive vacuolization by histology and significantly increased dry weights of total lipids found only in the livers of ADH{sup −} deer mice fed 3.5% ethanol vs. pair-fed controls suggest a dose-dependent formation of fatty liver in ADH{sup −} deer mouse model. Analysis of NMR data of ADH{sup −} deer mice fed 3.5% ethanol vs. pair-fed controls shows increases for total cholesterol, esterified cholesterol, fatty acid methyl esters (FAMEs), triacylglycerides and unsaturation, and decreases for free cholesterol, phospholipids and allylic and diallylic protons. Certain classes of neutral lipids (cholesterol esters, fatty acyl chain (-COCH{sub 2}-) and FAMEs) were

  14. Classification of edible oils by employing 31P and 1H NMR spectroscopy in combination with multivariate statistical analysis. A proposal for the detection of seed oil adulteration in virgin olive oils.

    PubMed

    Vigli, Georgia; Philippidis, Angelos; Spyros, Apostolos; Dais, Photis

    2003-09-10

    A combination of (1)H NMR and (31)P NMR spectroscopy and multivariate statistical analysis was used to classify 192 samples from 13 types of vegetable oils, namely, hazelnut, sunflower, corn, soybean, sesame, walnut, rapeseed, almond, palm, groundnut, safflower, coconut, and virgin olive oils from various regions of Greece. 1,2-Diglycerides, 1,3-diglycerides, the ratio of 1,2-diglycerides to total diglycerides, acidity, iodine value, and fatty acid composition determined upon analysis of the respective (1)H NMR and (31)P NMR spectra were selected as variables to establish a classification/prediction model by employing discriminant analysis. This model, obtained from the training set of 128 samples, resulted in a significant discrimination among the different classes of oils, whereas 100% of correct validated assignments for 64 samples were obtained. Different artificial mixtures of olive-hazelnut, olive-corn, olive-sunflower, and olive-soybean oils were prepared and analyzed by (1)H NMR and (31)P NMR spectroscopy. Subsequent discriminant analysis of the data allowed detection of adulteration as low as 5% w/w, provided that fresh virgin olive oil samples were used, as reflected by their high 1,2-diglycerides to total diglycerides ratio (D > or = 0.90).

  15. Determination of Three-Bond1H3‧-31P Couplings in Nucleic Acids and Protein-Nucleic Acid Complexes by QuantitativeJCorrelation Spectroscopy

    NASA Astrophysics Data System (ADS)

    Clore, G. Marius; Murphy, Elizabeth C.; Gronenborn, Angela M.; Bax, Ad

    1998-09-01

    A new sensitive two-dimensional quantitativeJcorrelation experiment is described for measuring3JH3‧-Pcouplings in nucleic acids and protein-nucleic acid complexes. The method is based on measuring the change in intensity of the1H-1H cross peaks in a constant-time1H-1H COSY experiment which occurs in the presence and absence of3JH3‧-Pdephasing during the constant-time evolution period. For protein-nucleic acid complexes where the protein is13C-labeled but the nucleic acid is not,12C-filtering is readily achieved by the application of a series of13C purge pulses during the constant time evolution period without any loss of signal-to-noise of the nucleic acid cross peaks. The method is demonstrated for the Dickerson DNA dodecamer and a 19 kDa complex of the transcription factor SRY with a 14mer DNA duplex. The same approach should be equally applicable to numerous other problems, including the measurement ofJH-Cdcouplings in cadmium-ligated proteins, or3JCHcouplings in other selectively enriched compounds.

  16. Interaction Study of an Amorphous Solid Dispersion of Cyclosporin A in Poly-Alpha-Cyclodextrin with Model Membranes by (1)H-, (2)H-, (31)P-NMR and Electron Spin Resonance.

    PubMed

    Debouzy, Jean-Claude; Crouzier, David; Bourbon, Fréderic; Lahiani-Skiba, Malika; Skiba, Mohamed

    2014-01-01

    The properties of an amorphous solid dispersion of cyclosporine A (ASD) prepared with the copolymer alpha cyclodextrin (POLYA) and cyclosporine A (CYSP) were investigated by (1)H-NMR in solution and its membrane interactions were studied by (1)H-NMR in small unilamellar vesicles and by (31)P (2)H NMR in phospholipidic dispersions of DMPC (dimyristoylphosphatidylcholine) in comparison with those of POLYA and CYSP alone. (1)H-NMR chemical shift variations showed that CYSP really interacts with POLYA, with possible adduct formation, dispersion in the solid matrix of the POLYA, and also complex formation. A coarse approach to the latter mechanism was tested using the continuous variations method, indicating an apparent 1 : 1 stoichiometry. Calculations gave an apparent association constant of log Ka = 4.5. A study of the interactions with phospholipidic dispersions of DMPC showed that only limited interactions occurred at the polar head group level ((31)P). Conversely, by comparison with the expected chain rigidification induced by CYSP, POLYA induced an increase in the fluidity of the layer while ASD formation led to these effects almost being overcome at 298 K. At higher temperature, while the effect of CYSP seems to vanish, a resulting global increase in chain fluidity was found in the presence of ASD.

  17. sup 31 P and sup 1 H NMR studies of the structure of enzyme-bound substrate complexes of lobster muscle arginine kinase: Relaxation measurements with Mn(II) and Co(II)

    SciTech Connect

    Jarori, G.K.; Ray, B.D.; Rao, B.D.N. )

    1989-11-28

    The paramagnetic effects of Mn(II) and Co(II) on the spin-lattice relaxation rates of {sup 31}P nuclei of ATP and ADP and of Mn(II) on the spin-lattice relaxation rate of the {delta} protons of arginine bound to arginine kinase from lobster tail muscle have been measured. Temperature variation of {sup 31}P relaxation rates in E-MnADP and E-MnATP yields activation energies ({Delta}E) in the range 6-10 kcal/mol. Thus, the {sup 31}P relaxation rates in these complexes are exchange limited and cannot provide structural information. However, the relaxation rates in E-CoADP and E-CoATP exhibit frequency dependence and {Delta}E values in the range 1-2 kcal/mol; i.e., these rates depend upon {sup 31}P-Co(II) distances. These distances were calculated to be in the range 3.2-4.5 {angstrom}, appropriate for direct coordination between Co(II) and the phosphoryl groups. The paramagnetic effect of Mn(II) on the {sup 1}H spin-lattice relaxation rate of the {delta} protons of arginine in the E-MnADP-Arg complex was also measured at three frequencies. From the frequency dependence of the relaxation rate an effective {tau}{sub C} of 0.6 ns has also been calculated, which is most likely to be the electron spin relaxation rate ({tau}{sub S1}) for Mn(II) in this complex. The distance estimated on the basis of the reciprocal sixth root of the average relaxation rate of the {delta} protons was 10.9 {plus minus} 0.3 {angstrom}.

  18. De novo design of chiral organotin cancer drug candidates: validation of enantiopreferential binding to molecular target DNA and 5'-GMP by UV-visible, fluorescence, (1)H and (31)P NMR.

    PubMed

    Arjmand, Farukh; Sharma, Girish Chandra; Sayeed, Fatima; Muddassir, Mohd; Tabassum, Sartaj

    2011-12-02

    N,N-bis[(R-/S-)-1-benzyl-2-ethoxyethane] tin (IV) complexes were synthesized by applying de novo design strategy by the condensation reaction of (R-/S-)2-amino-2-phenylethanol and dibromoethane in presence of dimethyltin dichloride and thoroughly characterized by elemental analysis, conductivity measurements, IR, ESI-MS, (1)H, (13)C and (119)Sn, multinuclear NMR spectroscopy and XRD study. Enantioselective and specific binding profile of R-enantiomer 1 in comparison to S-enantiomer 2 with ultimate molecular target CT-DNA was validated by UV-visible, fluorescence, circular dichroism, (1)H and (31)P NMR techniques. This was further corroborated well by interaction of 1 and 2 with 5'-GMP. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Multiple quantum correlated spectroscopy revamped by asymmetric z-gradient echo detection signal intensity as a function of the read pulse flip angle as verified by heteronuclear 1H/31P experiments.

    PubMed

    Jiang, Bin; Liu, Huili; Liu, Maili; Ye, Chaohui; Mao, Xi-an

    2007-02-07

    Heteronuclear multiple quantum (n=+/-0 and n=+/-2) correlated spectroscopy revamped by asymmetric z-gradient echo detection (CRAZED) experiments were performed on the spins 31P and 1H in a H3PO4 solution in order to determine the optimum flip angle for the read pulse. It has been shown that for the negative quantum signals, the maximum signals appear at beta=0, and for the positive quantum signals, the maximum signals appear at beta=pi. The CRAZED signals were compared to the single quantum signals in two-pulse two-gradient experiments. It is found that the CRAZED signals can also be distinguished into gradient echoes and spin echoes. The gradient-echo-type CRAZED signal requires beta=0 and the spin-echo-type CRAZED signal requires beta=pi for maximum echo intensities, in the same way as in single quantum experiments.

  20. In situ preparation and fate of cis-4-hydroxycyclophosphamide and aldophosphamide: 1H and 31P NMR evidence for equilibration of cis- and trans-4-hydroxycyclophosphamide with aldophosphamide and its hydrate in aqueous solution.

    PubMed

    Borch, R F; Hoye, T R; Swanson, T A

    1984-04-01

    cis-4-Hydroxycyclophosphamide (2) and aldophosphamide (4) were generated in aqueous phosphate or cacodylate buffer by dimethyl sulfide reduction of cis-4-hydroperoxycyclophosphamide (8) and by sodium periodate cleavage of 3,4-dihydroxybutyl N,N-bis(2-chloroethyl)phosphorodiamidate (9), respectively; the reactions of 2 and 4 were examined by 1H and 31P NMR. Within 30-60 min (pH or pD 7.0, 25 degrees C) the same pseudoequilibrium mixture was established in both reactions, with cis- and trans-4-hydroxycyclophosphamide (2 and 3), aldophosphamide (4), and its hydrate (5) present in the approximate ratio of 4:2:0.3:1. Structures of the intermediates were assigned unambiguously based upon analysis of the chemical shifts and coupling constants in the proton spectra determined in D2O buffers, and the 31P assignments followed by correlation of component ratios at equilibrium. Free energy differences of 0.4, 0.4, and 0.7 kcal/mol at 25 degrees C were estimated between 2, 3, 5, and 4, respectively, with 2 being the most stable. The aldehyde 4 reacted most rapidly with water to give hydrate 5; cyclization of 4 to 3 occurred faster than to 2, and the rate of cyclization to 2 was comparable to that for elimination to 6. Compound 5 is formed much faster than 3 from the diol cleavage, but 5 and 3 are produced at comparable rates from 2, suggesting that conversion of 2 to 3 can proceed by a mechanism other than ring opening. The rate of equilibration appears to be independent of buffer structure, indicating that bifunctional catalysis is not important in the ring-opening reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Monitoring the hydrolysis of toxic organophosphonate nerve agents in aqueous buffer and in bicontinuous microemulsions by use of diisopropyl fluorophosphatase (DFPase) with (1)H- (31)P HSQC NMR spectroscopy.

    PubMed

    Gäb, Jürgen; Melzer, Marco; Kehe, Kai; Wellert, Stefan; Hellweg, Thomas; Blum, Marc-Michael

    2010-02-01

    The enzyme diisopropyl fluorophosphatase (DFPase, EC 3.1.8.2) from the squid Loligo vulgaris effectively catalyzes the hydrolysis of diisopropyl fluorophosphate (DFP) and a number of organophosphorus nerve agents, including sarin, soman, cyclosarin, and tabun. Until now, determination of kinetic data has been achieved by use of techniques such as pH-stat titration, ion-selective electrodes, and a recently introduced method based on in situ Fourier-transform infrared (FTIR) spectroscopy. We report the use of 1D (1)H-(31)P HSQC NMR spectroscopy as a new method for real-time quantification of the hydrolysis of toxic organophosphonates by DFPase. The method is demonstrated for the agents sarin (GB), soman (GD), and cyclosarin (GD) but can also be used for V-type nerve agents, for example VX. Besides buffered aqueous solutions the method was used to determine enzymatic activities in a biodiesel-based bicontinuous microemulsion that serves as an example of complex decontamination media, for which other established techniques often fail. The method is non-invasive and requires only limited manual handling of small volumes of liquid (700 microL), which adds to work safety when handling highly toxic organophosphorus compounds. Limits of detection are slightly below 100 micromol L(-1) on a 400 MHz spectrometer with 16 FIDs added for a single time frame. The method is not restricted to DFPase but can be used with other phosphotriesterases, for example paraxonase (PON), and even reactive chemicals, for example oximes and other nucleophiles, as long as the reaction components are compatible with the NMR experiment.

  2. Investigation of metabolite changes in the transition from pre-invasive to invasive cervical cancer measured using (1)H and (31)P magic angle spinning MRS of intact tissue.

    PubMed

    De Silva, Sonali S; Payne, Geoffrey S; Thomas, Valerie; Carter, Paul G; Ind, Thomas E J; deSouza, Nandita M

    2009-02-01

    The aim of this study was to determine the metabolic changes in the transition from pre-invasive to invasive cervical cancer using high-resolution magic angle spinning (HR-MAS) MRS. Biopsy specimens were obtained from women with histologically normal cervix (n = 5), cervical intraepithelial neoplasia (CIN; mild, n = 5; moderate/severe, n = 40), and invasive cancer (n = 23). (1)H HR-MAS MRS data were acquired using a Bruker Avance 11.74 T spectrometer (Carr-Purcell-Meiboom-Gill sequence; TR = 4.8 s; TE = 135 ms; 512 scans; 41 min acquisition). (31)P HR-MAS spectra were obtained from the normal subjects and cancer patients only (as acetic acid applied before tissue sampling in patients with CIN impaired spectral quality) using a (1)H-decoupled pulse-acquire sequence (TR = 2.82 s; 2048 scans; 96 min acquisition). Peak assignments were based on values reported in the literature. Peak areas were measured using the AMARES algorithm. Estimated metabolite concentrations were compared between patient diagnostic categories and tissue histology using independent samples t tests. Comparisons based on patient category at diagnosis showed significantly higher estimated concentrations of choline (P = 0.0001) and phosphocholine (P = 0.002) in tissue from patients with cancer than from patients with high-grade dyskaryosis, but no differences between non-cancer groups. Division by histology of the sample also showed increases in choline (P = 0.002) and phosphocholine (P = 0.002) in cancer compared with high-grade CIN tissue. Phosphoethanolamine was increased in cancer compared with normal tissue (P = 0.0001). Estimated concentrations of alanine (P = 0.01) and creatine (P = 0.008) were significantly reduced in normal tissue from cancer patients compared with normal tissue from non-cancer patients. The estimated concentration of choline was significantly increased in CIN tissue from cancer patients compared with CIN tissue from non-cancer patients (P = 0.0001). Estimated

  3. Dynamic exchange between the covalent and dative metal-metal bonded isomers of the heterodinuclear complex (NiPd(CNMe) sub 3 (dppm) sub 2 )(PF sub 6 ) sub 2 by sup 31 P l brace sup 1 H r brace NOESY

    SciTech Connect

    Ni, Jinfeng; Kubiak, C.P. )

    1990-10-17

    The first quantitative dynamic study by {sup 31}P({sup 1}H) Nuclear Overhauser enhancement spectroscopy (NOESY) is described herein. The exchange between a pair of isomers of the complex (NiPd(CNMe){sub 3}(dppm){sub 2})(PF{sub 6}){sub 2} that differ in their mode of metal-metal bonding has been measured. The {sup 31}P({sup 1}H) NOSEY for this complex is ascribed to the relatively slow interconversion between the covalent and dative Ni-Pd bonded isomers. 13 refs., 2 figs., 2 tabs.

  4. Improving the Hyperpolarization of 31P Nuclei by Synthetic Design

    PubMed Central

    2015-01-01

    Traditional 31P NMR or MRI measurements suffer from low sensitivity relative to 1H detection and consequently require longer scan times. We show here that hyperpolarization of 31P nuclei through reversible interactions with parahydrogen can deliver substantial signal enhancements in a range of regioisomeric phosphonate esters containing a heteroaromatic motif which were synthesized in order to identify the optimum molecular scaffold for polarization transfer. A 3588-fold 31P signal enhancement (2.34% polarization) was returned for a partially deuterated pyridyl substituted phosphonate ester. This hyperpolarization level is sufficient to allow single scan 31P MR images of a phantom to be recorded at a 9.4 T observation field in seconds that have signal-to-noise ratios of up to 94.4 when the analyte concentration is 10 mM. In contrast, a 12 h 2048 scan measurement under standard conditions yields a signal-to-noise ratio of just 11.4. 31P-hyperpolarized images are also reported from a 7 T preclinical scanner. PMID:25811635

  5. Quantitative 31P magnetic resonance spectroscopy of the human breast at 7 T.

    PubMed

    Wijnen, Jannie P; van der Kemp, Wybe J M; Luttje, Mariska P; Korteweg, Mies A; Luijten, Peter R; Klomp, Dennis W J

    2012-08-01

    This study presents quantified levels of phosphorylated metabolites in glandular tissue of human breast using (31)P magnetic resonance spectroscopy at 7 T. We used a homebuilt (1)H/(31)P radiofrequency coil to obtain artifact-free (31)P MR spectra of glandular tissue of healthy females by deploying whole breast free induction decay (FID) detection with adiabatic excitation and outer volume suppression. Using progressive saturation, the estimated apparent T(1) relaxation time of (31)P spins of phosphocholine and phosphoethanolamine was 4.4 and 5.7 s, respectively. Quantitative measures for phosphocholine and phosphoethanolamine levels in glandular tissue were established based on MR imaging. We used a 3D (1)H image of the breast to segment the glandular tissue; this was matched to a 3D (31)P image of the B1- field of the (31)P coil to correct for differences in glandular tissue volume and B(1) inhomogeneity of the (31)P coil. The (31)P MR spectra were calibrated using a phantom with known concentration. Average levels of phosphocholine and phosphoethanolamine in 11 volunteers were 0.84 ± 0.21 mM and 1.18 ± 0.41 mM, respectively. In addition, data of three patients with breast cancer showed higher levels of phosphocholine and phosphoethanolamine compared with healthy volunteers. This may indicate a potential role for the use of (31)P magnetic resonance spectroscopy for characterization, prognosis, and treatment monitoring in breast cancer. Copyright © 2011 Wiley Periodicals, Inc.

  6. Bone Mineral Imaged In Vivo by 31P Solid State MRI of Human Wrists

    PubMed Central

    Wu, Yaotang; Reese, Timothy G.; Cao, Haihui; Hrovat, Mirko I.; Toddes, Steven P.; Lemdiasov, Rostislav A.; Ackerman, Jerome L.

    2011-01-01

    Purpose To implement solid state 31P MRI (31P SMRI) in a clinical scanner to visualize bone mineral. Materials and Methods Wrists of seven healthy volunteers were scanned. A quadrature wrist 31P transmit/receive coil provided strong B1 and good signal-to-noise ratio (SNR). A 1H-31P frequency converter was constructed to enable detection of the 31P signal via the 1H channel. Data points lost in the receiver dead time were recovered by a second acquisition with longer dwell time and lower gradient strength. Results Three dimensional 31P images, showing only bone mineral of the wrist, were obtained with a clinical 3T scanner. In the best overall case an image with isotropic resolution of ~5.1 mm and SNR of 30 was obtained in 37 min. 31P NMR properties (resonance line width 2 kHz and T1 17–19 s) of in vivo human bone mineral were measured. Conclusion In vivo 31P SMRI visualization of human wrist bone mineral with a clinical MR scanner is feasible with suitable modifications to circumvent the scanners’ limitations in reception of short-T2 signals. Frequency conversion methodology is useful for implementing 31P SMRI measurements on scanners which do not have multinuclear capability or for which the multinuclear receiver dead time is excessive. PMID:21761459

  7. MRI and (31)P magnetic resonance spectroscopy hardware for axillary lymph node investigation at 7T.

    PubMed

    Rivera, Debra S; Wijnen, Jannie P; van der Kemp, Wybe J M; Raaijmakers, Alexander J; Luijten, Peter R; Klomp, Dennis W J

    2015-05-01

    Neoadjuvant treatment response in lymph nodes predicts patient outcome, but existing methods do not track response during therapy accurately. In this study, specialized hardware was used to adapt high-field (7T) (31) P magnetic resonance spectroscopy (MRS), which has been shown to track treatment response in small breast tumors, to monitor axillary lymph nodes. A dual-tuned quadrature coil that is a (31) P (120 MHz) transceiver and a (1) H (300 MHz) receiver was designed using a novel detune circuit. The transceiver/receiver coil in the axilla is used with a fractionated dipole antenna on the back of the subject and the conventional breast coil for transmit. The novel circuit detuned the (1) H resonance without disturbing the (31) P resonance. In vivo demonstrations included: >80% homogeneous B1 (+) for (1) H over the axilla, identification of a small (3-mm diameter) lymph node, and (31) P MR spectra from a single healthy lymph node. The setup can detect <2 millimolar concentrations of metabolites from a 2-mL voxel. The first (31) P MR spectrum from an in vivo lymph node indicates that the presented design may be sufficiently sensitive to detect metabolic response to neoadjuvant therapy. Multinuclei MRS of the lymph nodes at 7T is possible through combining lightweight antenna elements with dual-tuned transceiver/receive-only coils. © 2014 Wiley Periodicals, Inc.

  8. Optimized 31P MRS in the human brain at 7 T with a dedicated RF coil setup

    PubMed Central

    van de Bank, Bart L.; Orzada, Stephan; Smits, Frits; Lagemaat, Miriam W.; Rodgers, Christopher T.; Bitz, Andreas K.

    2015-01-01

    The design and construction of a dedicated RF coil setup for human brain imaging (1H) and spectroscopy (31P) at ultra‐high magnetic field strength (7 T) is presented. The setup is optimized for signal handling at the resonance frequencies for 1H (297.2 MHz) and 31P (120.3 MHz). It consists of an eight‐channel 1H transmit–receive head coil with multi‐transmit capabilities, and an insertable, actively detunable 31P birdcage (transmit–receive and transmit only), which can be combined with a seven‐channel receive‐only 31P array. The setup enables anatomical imaging and 31P studies without removal of the coil or the patient. By separating transmit and receive channels and by optimized addition of array signals with whitened singular value decomposition we can obtain a sevenfold increase in SNR of 31P signals in the occipital lobe of the human brain compared with the birdcage alone. These signals can be further enhanced by 30 ± 9% using the nuclear Overhauser effect by B 1‐shimmed low‐power irradiation of water protons. Together, these features enable acquisition of 31P MRSI at high spatial resolutions (3.0 cm3 voxel) in the occipital lobe of the human brain in clinically acceptable scan times (~15 min). © 2015 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd. PMID:26492089

  9. Optimized (31)P MRS in the human brain at 7 T with a dedicated RF coil setup.

    PubMed

    van de Bank, Bart L; Orzada, Stephan; Smits, Frits; Lagemaat, Miriam W; Rodgers, Christopher T; Bitz, Andreas K; Scheenen, Tom W J

    2015-11-01

    The design and construction of a dedicated RF coil setup for human brain imaging ((1)H) and spectroscopy ((31)P) at ultra-high magnetic field strength (7 T) is presented. The setup is optimized for signal handling at the resonance frequencies for (1)H (297.2 MHz) and (31)P (120.3 MHz). It consists of an eight-channel (1)H transmit-receive head coil with multi-transmit capabilities, and an insertable, actively detunable (31)P birdcage (transmit-receive and transmit only), which can be combined with a seven-channel receive-only (31)P array. The setup enables anatomical imaging and (31)P studies without removal of the coil or the patient. By separating transmit and receive channels and by optimized addition of array signals with whitened singular value decomposition we can obtain a sevenfold increase in SNR of (31)P signals in the occipital lobe of the human brain compared with the birdcage alone. These signals can be further enhanced by 30 ± 9% using the nuclear Overhauser effect by B1-shimmed low-power irradiation of water protons. Together, these features enable acquisition of (31)P MRSI at high spatial resolutions (3.0 cm(3)  voxel) in the occipital lobe of the human brain in clinically acceptable scan times (~15 min). © 2015 The Authors. NMR in Biomedicine published by John Wiley & Sons Ltd.

  10. The Styrene Probe Applied to 15N and 77Se NMR

    DTIC Science & Technology

    1988-08-01

    ascertain if this was a general phenomenon in X-substituted cinnamate esters for atoms having unshared pairs of electrons, 15N chemical shift correlations...opposite to that predicted by the ’- polarization mechanism. To ascertain if this was a general phenomenon in a-substituted cinnamate esters for atoms...spatially proximate unshared electron pair in Series B. 77Se NXR of the E and Z isomers of ethyl a-(phenylseleno)- cinnamates (Series D) also revealed a

  11. Theory for ^77Se and ^125Te Nuclear Quadrupole Interactions in Selenium and Tellurium.

    NASA Astrophysics Data System (ADS)

    Suck-Cho, Hwa; Oh, Young-Kee; Park, Jin-Ho; Das, T. P.

    1998-03-01

    The electric field gradient(efg) tensors at ^77Se and ^125Te nuclei have been studied for the four systems involving each of these nuclei in both Selenium and Tellurium crystals utilizing the first principles Hartee-Fock Cluster procedure. Using the calculated efg for the pure systems and the experimental quadrupole coupling constants (e^2qQ), the quadrupole moments are determined to be Q(^77Se)=0.74±0,07(b) and Q(^125Te)=0.35±0.04(b). Comparison will be made with earlier values for the Q of the two nuclei. Using our values of Q and the calculated efg for ^77Se in tellurium and ^125Te in selenium, our values of e^2qQ agree within 15 per cent with that of experiment. The asymmetry parametrs η also agree reasonably well with experiment, but not as closely as the e^2qQ. Experimental results for η for ^125Te in selenium are needed to compare with theory.

  12. Band inversion amplifies (31) P-(31) P nuclear overhauser effects: Relaxation mechanism and dynamic behavior of ATP in the human brain by (31) P MRS at 7 T.

    PubMed

    Ren, Jimin; Sherry, A Dean; Malloy, Craig R

    2017-04-01

    To develop an improved method to measure the (31) P nuclear Overhauser effect (NOE) for evaluation of adenosine triphosphate (ATP) dynamics in terms of correlation time (τc ), and contribution of dipole-dipole (DD) and chemical shift anisotropy (CSA) mechanisms to T1 relaxation of ATP in human brain. The NOE of ATP in human brain was evaluated by monitoring changes in magnetization in the β-ATP signal following a band inversion of all downfield (31) P resonances. The magnetization changes observed were analyzed using the Bloch-McConnell-Solomon formulation to evaluate the relaxation and motion dynamic parameters that describe interactions of ATP with cellular solids in human brain tissue. The maximal transient NOE, observed as a reduction in the β-ATP signal, was 24 ± 2% upon band inversion of γ- and α-ATP, which is 2-3-fold higher than achievable by frequency-selective inversion of either γ- or α-ATP. The rate of (31) P-(31) P cross relaxation (0.21 ± 0.02 s(-1) ) led to a τc value of (9.1 ± 0.8) × 10(-8) s for ATP in human brain. The T1 relaxation of β-ATP is dominated by CSA over the DD mechanism (60%: 40%). The band inversion method proved effective in amplifying (31) P NOE, and thus facilitating ATP τc and relaxation measurements. This technique renders ATP a potentially useful reporter molecule for cellular environments. Magn Reson Med 77:1409-1418, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  13. 31P NMR Relaxation of Cortical Bone Mineral at Multiple Magnetic Field Strengths and Levels of Demineralization

    PubMed Central

    Seifert, Alan C.; Wright, Alexander C.; Wehrli, Suzanne L.; Ong, Henry H.; Li, Cheng; Wehrli, Felix W.

    2013-01-01

    Purpose Recent work has shown that solid-state 1H and 31P MRI can provide detailed insight into bone matrix and mineral properties, thereby potentially enabling differentiation of osteoporosis from osteomalacia. However, 31P MRI of bone mineral is hampered by unfavorable relaxation properties. Hence, accurate knowledge of these properties is critical to optimizing MRI of bone phosphorus. Methods In this work, 31P MRI signal-to-noise ratio (SNR) was predicted on the basis of T1 and T2* (effective transverse relaxation time) measured in lamb bone at six field strengths (1.5 – 11.7 T) and subsequently verified by 3-D ultra-short echo-time and zero echo-time imaging. Further, T1 was measured in deuterium-exchanged bone and partially demineralized bone. Results 31P T2* was found to decrease from 220.3 ± 4.3 μs to 98.0 ± 1.4 μs from 1.5 to 11.7 T, and T1 to increase from 12.8 ± 0.5 s to 97.3 ± 6.4 s. Deuteron substitution of exchangeable water showed that 76% of the 31P longitudinal relaxation rate is due to 1H-31P dipolar interactions. Lastly, hypomineralization was found to decrease T1, which may have implications for 31P MRI based mineralization density quantification. Conclusion Despite the steep decrease in the T2*/T1 ratio, SNR should increase with field strength as Bo0.4 for sample-dominated noise and as Bo1.1 for coil-dominated noise. This was confirmed by imaging experiments. PMID:23505120

  14. (31) P MR spectroscopic imaging of the human prostate at 7 T: T1 relaxation times, Nuclear Overhauser Effect, and spectral characterization.

    PubMed

    Lagemaat, Miriam W; Maas, Marnix C; Vos, Eline K; Bitz, Andreas K; Orzada, Stephan; Weiland, Elisabeth; van Uden, Mark J; Kobus, Thiele; Heerschap, Arend; Scheenen, Tom W J

    2015-03-01

    Optimization of phosphorus ((31) P) MR spectroscopic imaging (MRSI) of the human prostate at 7 T by the evaluation of T1 relaxation times and the Nuclear Overhauser Effect (NOE) of phosphorus-containing metabolites. Twelve patients with prostate cancer and one healthy volunteer were scanned on a 7 T whole-body system using a (31) P endorectal coil combined with an eight-channel (1) H body array coil. T1 relaxation times were measured using progressive saturation in a two-dimensional localization sequence. (31) P MRSI was performed twice: once without NOE and once with NOE using low-power continuous wave (1) H irradiation to determine NOE enhancements. T1 relaxation times of (31) P metabolites in the human prostate at 7 T varied between 3.0 and 8.3 s. Positive but variable NOE enhancements were measured for most metabolites. Remarkably, the (31) P MR spectra showed two peaks in chemical shift range of inorganic phosphate. Knowledge of T1 relaxation times and NOE enhancements enables protocol optimization for (31) P MRSI of the prostate at 7 T. With a strongly reduced (31) P flip angle (≤ 45°), a (31) P MRSI dataset with optimal signal-to-noise ratio per unit time can be obtained within 15 minutes. The NOE enhancement can improve fitting accuracy, but its variability requires further investigation. © 2014 Wiley Periodicals, Inc.

  15. Selenium-tellurium sequences in binary glasses as depicted by 77Se and 125Te NMR.

    PubMed

    Bureau, Bruno; Boussard-Plédel, Catherine; LeFloch, Marie; Troles, Johann; Smektala, Frédéric; Lucas, Jacques

    2005-04-07

    Some resolved solid state (77)Se NMR spectra are presented in the Te(x)Se(1-x) vitreous system at ambient temperature. They exhibit three different kinds of Se lines assigned to the following Se atom neighborhoods: Se-Se-Se, Se-Se-Te, and Te-Se-Te. Different models were considered to describe the way the Se and Te atoms are linked into the chains: clustering process, homogeneous distribution, random distribution. Finally, thanks to the measurements of the relative intensities of the lines, it appears that Se and Te atoms are mainly randomly distributed with a small preference for heteropolar bonds. The (125)Te spectra are also shown but their resolution is too weak to be informative concerning the vitreous network.

  16. ^77Se NMR in the Spin Density Wave state of (TMTSF)_2PF_6

    NASA Astrophysics Data System (ADS)

    Valfells, S.; Kuhns, P.; Kleinhammes, A.; Moulton, W.; Brooks, J. S.; Anzai, H.; Takasaki, S.; Yamada, J.

    1996-03-01

    We have measured the linewidth, T1 and T2 of the ^77Se nuclei in the quasi-1D conductor (TMTSF)_2PF6 above and below the Spin Density Wave transition temperature, T_SDW ≈ 12 K, at ambient pressure. We observe four distinct lines at T>T_SDW attributable to four non-equivalent Selenium sites and shifted by Δ ω / ω ≈ 0.7, 1.9, 3.8 and 4.5 × 10^4, respectively; they broaden to form a single, broad (≈ 900 kHz) line below T_SDW. The data, however, show no evidence of additional phase transitions at T

  17. Human cardiac 31P magnetic resonance spectroscopy at 7 tesla

    PubMed Central

    Rodgers, Christopher T; Clarke, William T; Snyder, Carl; Vaughan, J Thomas; Neubauer, Stefan; Robson, Matthew D

    2014-01-01

    Purpose Phosphorus magnetic resonance spectroscopy (31P-MRS) affords unique insight into cardiac energetics but has a low intrinsic signal-to-noise ratio (SNR) in humans. Theory predicts an increased 31P-MRS SNR at 7T, offering exciting possibilities to better investigate cardiac metabolism. We therefore compare the performance of human cardiac 31P-MRS at 7T to 3T, and measure T1s for 31P metabolites at 7T. Methods Matched 31P-MRS data were acquired at 3T and 7T, on nine normal volunteers. A novel Look-Locker CSI acquisition and fitting approach was used to measure T1s on six normal volunteers. Results T1s in the heart at 7T were: phosphocreatine (PCr) 3.05 ± 0.41s, γ-ATP 1.82 ± 0.09s, α-ATP 1.39 ± 0.09s, β-ATP 1.02 ± 0.17s and 2,3-DPG (2,3-diphosphoglycerate) 3.05 ± 0.41s (N = 6). In the field comparison (N = 9), PCr SNR increased 2.8× at 7T relative to 3T, the Cramer-Ráo uncertainty (CRLB) in PCr concentration decreased 2.4×, the mean CRLB in PCr/ATP decreased 2.7× and the PCr/ATP SD decreased 2×. Conclusion Cardiac 31P-MRS at 7T has higher SNR and the spectra can be quantified more precisely than at 3T. Cardiac 31P T1s are shorter at 7T than at 3T. We predict that 7T will become the field strength of choice for cardiac 31P-MRS. Magn Reson Med 72:304–315, 2014. © 2013 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited. PMID:24006267

  18. Location of protons in anhydrous Keggin heteropolyacids H(3)PMo(12)O(40) and H(3)PW(12)O(40) by (1)H[(31)P]/(31)P[(1)H] REDOR NMR and DFT quantum chemical calculations.

    PubMed

    Ganapathy, S; Fournier, M; Paul, J F; Delevoye, L; Guelton, M; Amoureux, J P

    2002-07-03

    HeteroPolyAcids (HPA's) are a class of solid acids that have broad applications in many fields of science and technology, including catalysis and chemical engineering. The proton locations within the thermally stable and commonly known Keggin unit, which is the primary structure building unit/block, has remained undetermined in anhydrous HPAs, despite numerous theoretical and experimental efforts. However, Rotational Echo DOuble Resonance (REDOR) NMR and Density Functional Theory (DFT) quantum chemical calculations offer a new opportunity to determine the exact locations of protons within the Keggin unit. The crucial experimental evidence is provided for the basic and very extensively studied acidic form of H(8-n)X(n+)M(12)O(40), X = Si, P and M = Mo, W, belonging to the Keggin structure. While showing that the acidic protons are located in the bridging oxygen positions (R(P-H) = 520 +/- 20 pm) in H(3)PMo(12)O(40) and in the terminal oxygen positions (R(P-H) = 570 +/- 20 pm) in H(3)PW(12)O(40), REDOR measurements also provide for the first time the structural basis to consistently rank the acid strength for the important class of Keggin solid catalysts.

  19. Kinetics of 1H --> 31P NMR cross-polarization in bone apatite and its mineral standards.

    PubMed

    Kaflak, Agnieszka; Kolodziejski, Waclaw

    2008-04-01

    Kinetics of NMR cross-polarization (CP) from protons to phosphorus-31 nuclei was studied in the following samples: mineral of whole human bone, apatite prepared from bone, natural brushite, synthetic hydroxyapatite (hydrated and calcined), and synthetic carbonatoapatite of type B with 9 wt% of CO(3) (2-). In order to avoid an effect of magic angle spinning on CP and relaxation, the experiments were carried out on static samples. Parameters of the CP kinetics were discussed for trabecular and cortical bone tissue from adult subjects in comparison to the synthetic mineral standards. It was found that carbonatoapatite shows similar CP behavior to the bone mineral. Both materials undergo two-component CP kinetics. The fast-relaxing classical component is from the surface of apatite crystals and the slow-relaxing nonclassical component comes from the crystal interior. The components have been unambiguously assigned using inverse CP from phosphorus-31 to protons. The study provides information on a structured water layer, which covers crystal surface of carbonato- and bone apatite. The layer encompasses ca 40% of apatite phosphorus and its thickness is more than ca 2 nm. Copyright (c) 2008 John Wiley & Sons, Ltd.

  20. CNS metabolism in high-risk drug abuse : Insights gained from (1)H-, (31)P-MRS and PET.

    PubMed

    Bodea, S

    2017-07-10

    High-risk drug consumption is a matter of great concern for public health actors in industrialised countries. The latest trends show a market tendency towards diversification and increasing demand for high-purity synthetic drugs. While most consumers seek medical help after cannabis use, it is high-risk drugs like cocaine, heroin and amphetamines that account for most of the 1000 drug-related deaths that occur in Germany every year. This article presents the most prominent in vivo cerebral metabolic information in cocaine, heroin and methamphetamine users provided by MRI spectroscopy and PET imaging. We reviewed the literature reporting neuroimaging studies of in vivo metabolic data for methamphetamine, cocaine and heroin consumption published up to March 2017. The search was conducted using PubMed and a combination of the following key words: methamphetamine, cocaine, heroin, MR spectroscopy, PET. MRI and PET are indispensable tools in gauging brain metabolic response to illegal drug abuse. Future breakthroughs in this field will most likely come from the investigation of novel neurotransmitter systems in PET and imaging phosphorus and carbon metabolites in MRI.

  1. Combined (Super 31)P and (Super 1)H NMR Experiments in the Structural Elucidation of Polynuclear Thiolate Complexes

    ERIC Educational Resources Information Center

    Cerrada, Elena; Laguna, Mariano

    2005-01-01

    A facile synthesis of two gold(I) complexes with 1,2-benzenedithiolate ligand and two different bidentate phosphines are described. A detailed sequence of NMR experiments is suggested to determine the structure of the compounds.

  2. High spin structure and intruder configurations in 31P

    NASA Astrophysics Data System (ADS)

    Ionescu-Bujor, M.; Iordachescu, A.; Napoli, D. R.; Lenzi, S. M.; Mărginean, N.; Otsuka, T.; Utsuno, Y.; Ribas, R. V.; Axiotis, M.; Bazzacco, D.; Bizzeti-Sona, A. M.; Bizzeti, P. G.; Brandolini, F.; Bucurescu, D.; Cardona, M. A.; De Angelis, G.; De Poli, M.; Della Vedova, F.; Farnea, E.; Gadea, A.; Hojman, D.; Kalfas, C. A.; Kröll, Th.; Lunardi, S.; Martínez, T.; Mason, P.; Pavan, P.; Quintana, B.; Alvarez, C. Rossi; Ur, C. A.; Vlastou, R.; Zilio, S.

    2006-02-01

    The nucleus 31P has been studied in the 24Mg(16O,2αp) reaction with a 70-MeV 16O beam. A complex level scheme extended up to spins 17/2+ and 15/2-, on positive and negative parity, respectively, has been established. Lifetimes for the new states have been investigated by the Doppler shift attenuation method. Two shell-model calculations have been performed to describe the experimental data, one by using the code ANTOINE in a valence space restricted to the sd shell, and the other by applying the Monte Carlo shell model in a valence space including the sd-fp shells. The latter calculation indicates that intruder excitations, involving the promotion of a T=0 proton-neutron pair to the fp shell, play a dominant role in the structure of the positive-parity high-spin states of 31P.

  3. Exploring new Routes for Identifying Phosphorus Species in Terrestrial and Aquatic Ecosystems with 31P NMR

    NASA Astrophysics Data System (ADS)

    Vestergren, Johan; Persson, Per; Sundman, Annelie; Ilstedt, Ulrik; Giesler, Reiner; Schleucher, Jürgen; Gröbner, Gerhard

    2014-05-01

    Phosphorus (P) is the primary growth-limiting nutrient in some of the world's biomes. Rock phosphate is a non-renewable resource and the major source of agricultural fertilizers. Predictions of P consumption indicate that rock phosphate mining may peak within 35 years, with severe impacts on worldwide food production1. Organic P compounds constitute a major fraction of soil P, but little is known about the dynamics and bioavailability of organic P species. Our aim is to develop new liquid and solid state 31P-NMR (nuclear magnetic resonance) techniques to identify P-species in water and soils; information required for correlating P speciation with plant and soil processes2, and eventually to improve P use. Soil organic P is frequently extracted using NaOH/EDTA, followed by characterization of the extract by solution 31P-NMR. However, the obtained NMR spectra usually have poor resolution due to line broadening caused by the presence of paramagnetic ions. Therefore, we successfully developed an approach to avoid paramagnetic line broadening by precipitation of metal sulfides. Sulfide precipitation dramatically reduces NMR line widths for soil extracts, without affecting P-composition. The resulting highly improved resolution allowed us to apply for the first time 2D 1H,31P-NMR methods to identify different P monoesters in spectral regions which are extremely crowded in 1D NMR spectra.3 By exploiting 2D 1H-31P NMR spectra of soil extracts we were able to unambiguously identify individual organic P species by combining 31P and 1H chemical shifts and coupling constants. This approach is even suitable for a structural characterization of unknown P-components and for tracing degradation pathways between diesters and monoesters3,4.Currently we apply our approach on boreal4 and tropical soils with focus on Burkina Faso. In addition we also monitor P-species in aqueos ecosystems. For this purpose stream water from the Krycklan catchment in northern Sweden5 has been used to

  4. Proton-decoupled 31P MRS in untreated pediatric brain tumors.

    PubMed

    Albers, Mark J; Krieger, Mark D; Gonzalez-Gomez, Ignacio; Gilles, Floyd H; McComb, J Gordon; Nelson, Marvin D; Blüml, Stefan

    2005-01-01

    Proton-decoupled (31)P and (1)H MRS was used to quantify markers of membrane synthesis and breakdown in eight pediatric patients with untreated brain tumors and in six controls. Quantitation of these compounds in vivo in humans may provide important indicators for tumor growth and malignancy, tumor classification, and provide prognostic information. The ratios of phosphoethanolamine to glycerophosphoethanolamine (PE/GPE) and phosphocholine to glycerophosphocholine (PC/GPC) were significantly higher in primitive neuroectodermal tumors (PNET) (16.30 +/- 5.73 and 2.97 +/- 0.93) when compared with controls (3.42 +/- 1.62, P < 0.0001 and 0.45 +/- 0.13, P < 0.0001) and with other tumors (3.93 +/- 3.42, P < 0.001 and 0.65 +/- 0.30, P < 0.0001). Mean PC/PE was elevated in tumors relative to controls (0.48 +/- 0.11 versus 0.24 +/- 0.05, P < 0.001), but there was no difference between PNET and other tumors. Total choline concentration determined with quantitative (1)H MRS was significantly elevated (4.78 +/- 3.33 versus 1.73 +/- 0.56 mmol/kg, P < 0.05), whereas creatine was reduced in tumors (4.89 +/- 1.83 versus 8.28 +/- 1.50 mmol/kg, P < 0.05). A quantitative comparison of total phosphorylated cholines (PC+GPC)/ATP measured with (31)P MRS and total choline measured with (1)H MRS showed that in tumors a large fraction of the choline signal (>54 +/- 36%) was not accounted for by PC and GPC. The fraction of unaccounted choline was particularly large in PNET (>78 +/- 7%). The pH of tumor tissue was higher than the pH of normal brain tissue (7.06 +/- 0.03 versus. 6.98 +/- 0.03, P < 0.001).

  5. Incorporation of phosphorus guest ions in the calcium silicate phases of Portland cement from 31P MAS NMR spectroscopy.

    PubMed

    Poulsen, Søren L; Jakobsen, Hans J; Skibsted, Jørgen

    2010-06-21

    Portland cements may contain small quantities of phosphorus (typically below 0.5 wt % P(2)O(5)), originating from either the raw materials or alternative sources of fuel used to heat the cement kilns. This work reports the first (31)P MAS NMR study of anhydrous and hydrated Portland cements that focuses on the phase and site preferences of the (PO(4))(3-) guest ions in the main clinker phases and hydration products. The observed (31)P chemical shifts (10 to -2 ppm), the (31)P chemical shift anisotropy, and the resemblance of the lineshapes in the (31)P and (29)Si MAS NMR spectra strongly suggest that (PO(4))(3-) units are incorporated in the calcium silicate phases, alite (Ca(3)SiO(5)) and belite (Ca(2)SiO(4)), by substitution for (SiO(4))(4-) tetrahedra. This assignment is further supported by a determination of the spin-lattice relaxation times for (31)P in alite and belite, which exhibit the same ratio as observed for the corresponding (29)Si relaxation times. From simulations of the intensities, observed in inversion-recovery spectra for a white Portland cement, it is deduced that 1.3% and 2.1% of the Si sites in alite and belite, respectively, are replaced by phosphorus. Charge balance may potentially be achieved to some extent by a coupled substitution mechanism where Ca(2+) is replaced by Fe(3+) ions, which may account for the interaction of the (31)P spins with paramagnetic Fe(3+) ions as observed for the ordinary Portland cements. A minor fraction of phosphorus may also be present in the separate phase Ca(3)(PO(4))(2), as indicated by the observation of a narrow resonance at delta((31)P) = 3.0 ppm for two of the studied cements. (31)P{(1)H} CP/MAS NMR spectra following the hydration of a white Portland cement show that the resonances from the hydrous phosphate species fall in the same spectral range as observed for (PO(4))(3-) incorporated in alite. This similarity and the absence of a large (31)P chemical shift ansitropy indicate that the hydrous (PO(4

  6. Pressure response of (31)P chemical shifts of adenine nucleotides.

    PubMed

    Karl, Matthias; Spoerner, Michael; Pham, Thuy-Vy; Narayanan, Sunilkumar Puthenpurackal; Kremer, Werner; Kalbitzer, Hans Robert

    2017-03-30

    High pressure NMR spectroscopy is a powerful method for identifying rare conformational states of proteins from the pressure response of their chemical shifts. Many proteins have bound adenine nucleotides at their active centers, in most cases in a complex with Mg(2+)-ions. The (31)P NMR signals of phosphate groups of the nucleotides can be used as probes for conformational transitions in the proteins themselves. For distinguishing protein specific pressure effects from trivial pressure responses not due to the protein interaction, data of the pressure response of the free nucleotides must be available. Therefore, the pressure response of (31)P chemical shifts of the adenine nucleotides AMP, ADP, and ATP and their Mg(2+)-complexes has been determined at pH values several units distant from the respective pK-values. It is clearly non-linear for most of the resonances. A negative first order pressure coefficient B1 was determined for all (31)P resonances except Mg(2+)·AMP indicating an upfield shift of the resonances with pressure. The smallest and largest negative values are obtained for the α-phosphate group of ADP and β-phosphate group of Mg(2+)·ATP with -0.32 and -4.59ppm/GPa, respectively. With exception of the α-phosphate group of Mg(2+)·AMP the second order pressure coefficients are positive leading to a saturation like behaviour. The pressure response of the adenine nucleotides is similar but not identical to that observed earlier for guanine nucleotides. The obtained data show that the chemical shift pressure response of the different phosphate groups is rather different dependent on the position of phosphate group in the nucleotide and the nucleotide used. Copyright © 2016. Published by Elsevier B.V.

  7. Magnetic properties of the magnetoelectric compound Cu2OSeO3: Magnetization and 77Se NMR study

    NASA Astrophysics Data System (ADS)

    Belesi, M.; Philippe, T.; Rousochatzakis, I.; Wu, H. C.; Berger, H.; Granville, S.; Shvets, I. V.; Ansermet, J.-Ph

    2011-07-01

    We present magnetization and 77Se Nuclear Magnetic Resonance (NMR) measurements in single crystals of the magneteoelectric compound Cu2OSeO3. The temperature and field dependence of the magnetization suggest a ferrimagnetic ordering at Tc ≃ 60 K in a 3up-1down configuration. The easy axis of the magnetization is along the [100] crystallographic direction. The 77Se NMR line shape data collected at 14.09 T are consistent with the symmetries imposed by the cubic P213 space group in the temperature range 20-290 K and confirm that the magnetic transition is not accompanied by any lowering of the crystal symmetry as has recently been proposed by Bos et al. [Phys. Rev. B 78 094416 (2008)].

  8. Structure of Amorphous Selenium by 2D (77) Se NMR Spectroscopy: An End to the Dilemma of Chain versus Ring.

    PubMed

    Marple, Maxwell; Badger, Jackson; Hung, Ivan; Gan, Zhehong; Kovnir, Kirill; Sen, Sabyasachi

    2017-08-07

    Amorphous selenium, owing to its tremendous technological importance and perhaps to its chemical simplicity, has been studied for nearly a century and yet an unequivocal structural description of this material remains lacking to date. The primary controversy regarding the structure of amorphous Se relates to the relative fraction of Se atoms residing in ∞1Se chains versus in Se8 rings. Herein we present the results of a two-dimensional solid-state (77) Se nuclear magnetic resonance (NMR) spectroscopic study of the chain and ring crystalline allotropes of Se as well as of amorphous Se to unequivocally demonstrate that 1) the Se8 rings and the ∞1Se chains are characterized by their unique (77) Se NMR signatures and 2) the structure of amorphous Se consists exclusively of ∞1Se chains. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Applications of 31P NMR to clinical biochemistry.

    PubMed

    Chance, B

    1984-01-01

    In summary, phosphorus NMR presents a well documented, continuous, and noninvasive assay of cell energy metabolism in a variety of body organs. In the form used here, it is appropriate to the study of vascular and genetic diseases of the skeletal tissues of adults and energy-related diseases of the body organs in neonates. Under these conditions, 31P NMR is not an expensive installation, has a small up-keep cost, and one which in our experience can be operated by a college graduate technician with ease. We foresee a significant and generalized application to tissue biochemistry in humans.

  10. 31P NMR spectroscopy of in vivo tumors

    NASA Astrophysics Data System (ADS)

    Ng, T. C.; Evanochko, W. T.; Hiramoto, R. N.; Ghanta, V. K.; Lilly, M. B.; Lawson, A. J.; Corbett, T. H.; Durant, J. R.; Glickson, J. D.

    A probe, suitable for any wide-bore NMR spectrometer, was constructed for monitoring high-resolution spectra of in vivo subcutaneously implanted tumors in mice. Preliminary studies of a variety of murine tumors (MOPC 104E myeloma, Dunn osteosarcoma, colon-26, ovarian M5, and mammary adenocarcinoma as well as human colon, mammary, and lung tumors in athymic mice) indicate that the 31P NMR spectrum is a sensitive monitor of progressive metabolic changes that occur during untreated tumor growth and an early indicator of tumor response to chemotherapy, hyperthermia, and X radiation. Response to each of these therapeutic modalities is accompanied by distinctly different spectral changes.

  11. Method development in quantitative NMR towards metrologically traceable organic certified reference materials used as (31)P qNMR standards.

    PubMed

    Weber, Michael; Hellriegel, Christine; Rueck, Alexander; Wuethrich, Juerg; Jenks, Peter; Obkircher, Markus

    2015-04-01

    Quantitative nuclear magnetic resonance (qNMR) spectroscopy is employed by an increasing number of analytical and industrial laboratories for the assignment of content and quantitative determination of impurities. Within the last few years, it was demonstrated that (1)H qNMR can be performed with high accuracy leading to measurement uncertainties below 1 % relative. It was even demonstrated that the combination of (1)H qNMR with metrological weighing can lead to measurement uncertainties below 0.1 % when highly pure substances are used. Although qNMR reference standards are already available as certified reference materials (CRM) providing traceability on the basis of (1)H qNMR experiments, there is an increasing demand for purity assays on phosphorylated organic compounds and metabolites requiring CRM for quantification by (31)P qNMR. Unfortunately, the number of available primary phosphorus standards is limited to a few inorganic CRM which only can be used for the analysis of water-soluble analytes but fail when organic solvents must be employed. This paper presents the concept of value assignment by (31)P qNMR measurements for the development of CRM and describes different approaches to establish traceability to primary Standard Reference Material from the National Institute of Standards and Technology (NIST SRM). Phosphonoacetic acid is analyzed as a water-soluble CRM candidate, whereas triphenyl phosphate is a good candidate for the use as qNMR reference material in organic solvents. These substances contain both nuclei, (1)H and (31)P, and the concept is to show that it is possible to indirectly quantify a potential phosphorus standard via its protons using (1)H qNMR. The same standard with its assigned purity can then be used for the quantification of an analyte via its phosphorus using (31)P qNMR. For the validation of the concept, triphenyl phosphate and phosphonoacetic acid have been used as (31)P qNMR standards to determine the purity of the analyte

  12. Whole-body radiofrequency coil for (31) P MRSI at 7 T.

    PubMed

    Löring, J; van der Kemp, W J M; Almujayyaz, S; van Oorschot, J W M; Luijten, P R; Klomp, D W J

    2016-06-01

    Widespread use of ultrahigh-field (31) P MRSI in clinical studies is hindered by the limited field of view and non-uniform radiofrequency (RF) field obtained from surface transceivers. The non-uniform RF field necessitates the use of high specific absorption rate (SAR)-demanding adiabatic RF pulses, limiting the signal-to-noise ratio (SNR) per unit of time. Here, we demonstrate the feasibility of using a body-sized volume RF coil at 7 T, which enables uniform excitation and ultrafast power calibration by pick-up probes. The performance of the body coil is examined by bench tests, and phantom and in vivo measurements in a 7-T MRI scanner. The accuracy of power calibration with pick-up probes is analyzed at a clinical 3-T MR system with a close to identical (1) H body coil integrated at the MR system. Finally, we demonstrate high-quality three-dimensional (31) P MRSI of the human body at 7 T within 5 min of data acquisition that includes RF power calibration. Copyright © 2016 John Wiley & Sons, Ltd.

  13. Lateral diffusion of bilayer lipids measured via (31)P CODEX NMR.

    PubMed

    Saleem, Qasim; Lai, Angel; Morales, Hannah H; Macdonald, Peter M

    2012-10-01

    We have employed (31)P CODEX (centre-band-only-detection-of-exchange) NMR to measure lateral diffusion coefficients of phospholipids in unilamellar lipid bilayer vesicles consisting of 1-palmitoyl-2-oleoyl-phosphatidylcholine (POPC), alone or in mixtures with 30 mol% 1-palmitoyl-2-oleoyl-phosphatidylglycerol (POPG) or cholesterol (CHOL). The lateral diffusion coefficients of POPC and POPG were extracted from experimental CODEX signal decays as a function of increasing mixing time, after accounting for the vesicle's size and size distribution, as determined via dynamic light scattering, and the viscosity of the vesicular suspension, as determined via (1)H pulsed field gradient NMR. Lateral diffusion coefficients for POPC and POPG determined in this fashion fell in the range 1.0-3.2 × 10(-12) m(2) s(-1) at 10 °C, depending on the vesicular composition, in good agreement with accepted values. Thus, two advantages of (31)P CODEX NMR for phospholipid lateral diffusion measurements are demonstrated: no labelling of the molecule of interest is necessary, and multiple lateral diffusion coefficients can be measured simultaneously. It is expected that this approach will prove particularly useful in diagnosing heterogeneities in lateral diffusion behaviours, such as might be expected for specific lipid-lipid or lipid-protein interactions, and thermotropic or electrostatically induced phase inhomogeneities.

  14. Nuclear-Overhauser-enhanced MR imaging of (31)P-containing metabolites: multipoint-Dixon vs. frequency-selective excitation.

    PubMed

    Rink, Kristian; Berger, Moritz C; Korzowski, Andreas; Breithaupt, Mathies; Biller, Armin; Bachert, Peter; Nagel, Armin M

    2015-12-01

    The purpose of this study is to develop nuclear-Overhauser-enhanced (NOE) [(1)H]-(31)P magnetic resonance imaging (MRI) based on 3D fully-balanced steady-state free precession (fbSSFP). Therefore, two implementations of a 3D fbSSFP sequence are compared using frequency-selective excitation (FreqSel) and multipoint-Dixon (MP-Dixon). (31)P-containing model solutions and four healthy volunteers were examined at field strengths of B0=3T and 7T. Maps of the distribution of phosphocreatine (PCr), inorganic phosphate (Pi), and adenosine 5´-triphosphate (ATP) in the human calf were obtained with an isotropic resolution of 1.5cm (1.0cm) in an acquisition time of 5min (10min). NOE-pulses had the highest impact on the PCr acquisitions enhancing the signal up to (82 ± 13) % at 3T and up to (37 ± 9) % at 7T. An estimation of the level of PCr in muscle tissue from [(1)H]-(31)P MRI data yielded a mean value of (33 ± 8) mM. In conclusion, direct [(1)H]-(31)P imaging using FreqSel as well as MP-Dixon is possible in clinically feasible acquisition times. FreqSel should be preferred for measurements where only a single metabolite resonance is considered. MP-Dixon performs better in terms of SNR if a larger spectral width is of interest. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Differential cross sections measurement of 31P(p,pγ1)31P reaction for PIGE applications

    NASA Astrophysics Data System (ADS)

    Jokar, A.; Kakuee, O.; Lamehi-Rachti, M.

    2016-09-01

    Differential cross sections of proton induced gamma-ray emission from the 31P(p,pγ1)31P (Eγ = 1266 keV) nuclear reaction were measured in the proton energy range of 1886-3007 keV at the laboratory angle of 90°. For these measurements a thin Zn3P2 target evaporated onto a self-supporting C film was used. The gamma-rays and backscattered protons were detected simultaneously. An HPGe detector placed at an angle of 90° with respect to the beam direction was employed to collect gamma-rays while an ion implanted Si detector placed at a scattering angle of 165° was used to detect backscattered protons. Simultaneous collection of gamma-rays and RBS spectra is a great advantage of this approach which makes differential cross-section measurements independent on the collected beam charge. The obtained cross-sections were compared with the previously only measured data in the literature. The validity of the measured differential cross sections was verified through a thick target benchmarking experiment. The overall systematic uncertainty of cross section values was estimated to be better than ±9%.

  16. U1h Superstructure

    SciTech Connect

    Glen Sykes

    2000-11-01

    The U1H Shaft Project is a design build subcontract to supply the U. S. Department of Energy (DOE) a 1,045 ft. deep, 20 ft. diameter, concrete lined shaft for unspecified purposes. The subcontract awarded to Atkinson Construction by Bechtel Nevada to design and construct the shaft for the DOE has been split into phases with portions of the work being released as dictated by available funding. The first portion released included the design for the shaft, permanent hoist, headframe, and collar arrangement. The second release consisted of constructing the shaft collar to a depth of 110 ft., the service entry, utility trenches, and installation of the temporary sinking plant. The temporary sinking plant included the installation of the sinking headframe, the sinking hoist, two deck winches, the shaft form, the sinking work deck, and temporary utilities required to sink the shaft. Both the design and collar construction were completed on schedule. The third release consisted of excavating and lining the shaft to the station depth of approximately 950 feet. Work is currently proceeding on this production sinking phase. At a depth of approximately 600 feet, Atkinson has surpassed production expectation and is more than 3 months ahead of schedule. Atkinson has employed the use of a Bobcat 331 excavator as the primary means of excavation. the shaft is being excavated entirely in an alluvial deposit with varying degrees of calcium carbonate cementation. Several more work packages are expected to be released in the near future. The remaining work packages include, construction of the shaft station a depth of 975 ft. and construction of the shaft sump to a depth of 1,045 ft., installation of the loading pocket and station steel and equipment, installation of the shaft steel and guides, installation of the shaft utilities, and installation of the permanent headframe, hoist, collar utilities, and facilities.

  17. Decreased brain PME/PDE ratio in bipolar disorder: a preliminary (31) P magnetic resonance spectroscopy study.

    PubMed

    Shi, Xian-Feng; Carlson, Paul J; Sung, Young-Hoon; Fiedler, Kristen K; Forrest, Lauren N; Hellem, Tracy L; Huber, Rebekah S; Kim, Seong-Eun; Zuo, Chun; Jeong, Eun-Kee; Renshaw, Perry F; Kondo, Douglas G

    2015-11-01

    The aim of the present study was to measure brain phosphorus-31 magnetic resonance spectroscopy ((31) P MRS) metabolite levels and the creatine kinase reaction forward rate constant (kf ) in subjects with bipolar disorder (BD). Subjects with bipolar euthymia (n = 14) or depression (n = 11) were recruited. Healthy comparison subjects (HC) (n = 23) were recruited and matched to subjects with BD on age, gender, and educational level. All studies were performed on a 3-Tesla clinical magnetic resonance imaging system using a (31) P/(1) H double-tuned volume head coil. (31) P spectra were acquired without (1) H-decoupling using magnetization-transfer image-selected in vivo spectroscopy. Metabolite ratios from a brain region that includes the frontal lobe, corpus callosum, thalamus, and occipital lobe are expressed as a percentage of the total phosphorus (TP) signal. Brain pH was also investigated. Beta-nucleoside-triphosphate (β-NTP/TP) in subjects with bipolar depression was positively correlated with kf (p = 0.039, r(2) = 0.39); similar correlations were not observed in bipolar euthymia or HC. In addition, no differences in kf and brain pH were observed among the three diagnostic groups. A decrease in the ratio of phosphomonoesters to phosphodiesters (PME/PDE) was observed in subjects with bipolar depression relative to HC (p = 0.032). We also observed a trend toward an inverse correlation in bipolar depression characterized by decreased phosphocreatine and increased depression severity. In our sample, kf was not altered in the euthymic or depressed mood state in BD. However, decreased PME/PDE in subjects with bipolar depression was consistent with differences in membrane turnover. These data provide preliminary support for alterations in phospholipid metabolism and mitochondrial function in bipolar depression. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Selenium Chain Length Distribution in GexSe100-x Glasses: Insights from (77)Se NMR Spectroscopy and Quantum Chemical Calculations.

    PubMed

    Kaseman, Derrick C; Oliveira, Karina Moreira; Palazzo, Teresa; Sen, Sabyasachi

    2016-05-19

    The statistics of selenium chain length distribution in GexSe100-x glasses with 5 ≤ x ≤ 20 are investigated using a combination of high-resolution, two-dimensional (77)Se nuclear magnetic resonance (NMR) spectroscopy and quantum chemical calculations. This combined approach allows for the distinction of various selenium chain environments on the basis of subtle but systematic effects of next-nearest neighbors of Se atoms in -Se-Se-Se- linkages on the (77)Se chemical shift tensor parameters. Simulation of the experimental (77)Se NMR spectral line shapes indicates that Se chain speciation in these chalcogenide glasses follows the Flory-Schulz distribution, originally developed for organic chain polymers.

  19. Tendencies of 31P chemical shifts changes in NMR spectra of nucleotide derivatives.

    PubMed Central

    Lebedev, A V; Rezvukhin, A I

    1984-01-01

    31P NMR chemical shifts of the selected mono- and oligonucleotide derivatives, including the compounds with P-N, P-C, P-S bonds and phosphite nucleotide analogues have been presented. The influence of substituents upon 31P chemical shifts has been discussed. The concrete examples of 31P chemical shifts data application in the field of nucleotide chemistry have been considered. PMID:6087290

  20. Solid state {sup 31}P/{sup 27}Al and {sup 31}P/{sup 23}Na MAS NMR dipolar dephasing investigations of connectivity in sodium aluminophosphate glasses

    SciTech Connect

    LANG,DAVID P.; ALAM,TODD M.; BENCOE,DENISE N.

    2000-05-01

    Solid state {sup 31}P/{sup 27}Al and {sup 31}P/{sup 23}Na MAS NMR dipolar dephasing experiments have been used to investigate the spatial distribution of aluminum and sodium cations with respect to the phosphate backbone for a series of sodium aluminophosphate glasses, xAl{sub 2}O{sub 3}{center_dot}50Na{sub 2}O{center_dot}(50{minus}x)P{sub 2}O{sub 5} (0{le} x {le} 17.5). From the {sup 31}P/{sup 27}Al and {sup 31}P/{sup 23}Na connectivity data gathered, information about the medium range order in these glasses is obtained. The expanded connectivity data allows for better identification and interpretation of the new resonances observed in the {sup 31}P MAS NMR spectra with the addition of alumina. The results of the dipolar dephasing experiments show that the sodium-phosphate distribution remains relatively unchanged for the glass series, and that the addition of aluminum occurs primarily through the depolymerization of the phosphate tetrahedral backbone.

  1. The effects of intramolecular and intermolecular coordination on (31)P nuclear shielding: phosphorylated azoles.

    PubMed

    Chernyshev, Kirill A; Larina, Ludmila I; Chirkina, Elena A; Krivdin, Leonid B

    2012-02-01

    The effects of intramolecular and intermolecular coordination on (31)P nuclear shielding have been investigated in the series of tetracoordinated, pentacoordinated and hexacoordinated N-vinylpyrazoles and intermolecular complexes of N-vinylimidazole and 1-allyl-3,5-dimethylpyrazole with phosphorous pentachloride both experimentally and theoretically. It was shown that either intramolecular or intermolecular coordination involving phosphorous results in a dramatic (31)P nuclear shielding amounting to approximately 150 ppm on changing the phosphorous coordination number by one. A major importance of solvent effects on (31)P nuclear shielding of intramolecular and intermolecular complexes involving N → P coordination bond has been demonstrated. It was found that the zeroth-order regular approximation-gauge-including atomic orbital-B1PW91/DZP method was sufficiently accurate for the calculation of (31)P NMR chemical shifts, provided relativistic corrections are taken into account, the latter being of crucial importance in the description of (31)P nuclear shielding.

  2. Quantitative (31)P HR-MAS MR spectroscopy for detection of response to PI3K/mTOR inhibition in breast cancer xenografts.

    PubMed

    Esmaeili, Morteza; Bathen, Tone F; Engebråten, Olav; Mælandsmo, Gunhild M; Gribbestad, Ingrid S; Moestue, Siver A

    2014-06-01

    Phospholipid metabolites are of importance in cancer studies, and have been suggested as candidate metabolic biomarkers for response to targeted anticancer drugs. The purpose of this study was to develop a phosphorus ((31) P) high resolution magic angle spinning magnetic resonance spectroscopy protocol for quantification of phosphorylated metabolites in intact cancer tissue. (31) P spectra were acquired on a 14.1 T spectrometer with a triplet (1) H/(13) C/(31) P MAS probe. Quantification of metabolites was performed using the PULCON principle. Basal-like and luminal-like breast cancer xenografts were treated with the dual PI3K/mTOR inhibitor BEZ235, and the impact of treatment on the concentration of phosphocholine, glycerophosphocholine, phosphoethanolamine and glycerophosphoethanolamine was evaluated. In basal-like xenografts, BEZ235 treatment induced a significant decrease in phosphoethanolamine (-25.6%, P = 0.01) whilst phosphocholine (16.5%, P = 0.02) and glycerophosphocholine (37.3%, P < 0.001) were significantly increased. The metabolic changes could partially be explained by increased levels of phospholipase A2 group 4A (PLA2G4A). (31) P high resolution magic angle spinning magnetic resonance spectroscopy is a useful method for quantitative assessment of metabolic responses to PI3K inhibition. Using the PULCON principle for quantification, the levels of phosphocholine, glycerophosphocholine, phosphoethanolamine, and glycerophosphoethanolamine could be evaluated with high precision and accuracy. Copyright © 2013 Wiley Periodicals, Inc.

  3. Chiral trimethylsilylated C2-symmetrical diamines as phosphorous derivatizing agents for the determination of the enantiomeric excess of chiral alcohols by 1H NMR

    PubMed Central

    Chauvin, Anne-Sophie; Alexakis, Alexandre

    2006-01-01

    The use of organophosphorus derivatising agents, prepared from C2 symmetric trimethylsilylated diamines, for the 1H NMR and 31P NMR determination of the enantiomeric composition of chiral alcohols is described. PMID:16566844

  4. 31P nuclear magnetic resonance study of the proton-irradiated KTiOPO4

    NASA Astrophysics Data System (ADS)

    Kim, Se-Hun; Lee, Cheol Eui

    2013-08-01

    31P nuclear magnetic resonance (NMR) was employed to study the effects of proton irradiation on KTiOPO4 (KTP) in view of the previously studied paramagnetic impurity doping effects. High-resolution 31P NMR measurements showed significant increase in the isotropic chemical shifts of the two inequivalent phosphorus sites in the proton-irradiated KTP system, indicating decrease in the electron density around the phosphorous nuclei. The 31P NMR linewidths of the KTP system manifested anomalies associated with the superionic transition and with the polaron formation, which became much weaker after proton irradiation. Besides, the activation energy of the charge carriers increased significantly after proton irradiation.

  5. Study of hereditary fructose intolerance by use of 31P magnetic resonance spectroscopy.

    PubMed

    Oberhaensli, R D; Rajagopalan, B; Taylor, D J; Radda, G K; Collins, J E; Leonard, J V; Schwarz, H; Herschkowitz, N

    1987-10-24

    The effect of fructose on liver metabolism in patients with hereditary fructose intolerance (HFI) and in heterozygotes for HFI was studied by 31P magnetic resonance spectroscopy (31P-MRS). In patients with HFI (n = 5) ingestion of small amounts of fructose was followed by an increase in sugar phosphates and decrease in inorganic phosphate (Pi) in the liver that could be detected by 31P-MRS. 31P-MRS could be used to diagnose fructose intolerance and to monitor the patients' compliance with a fructose-restricted diet. In heterozygotes (n = 8) 50 g fructose given orally led to accumulation of sugar phosphates and depletion of Pi in the liver. Fructose also induced a larger increase in plasma urate in heterozygotes than in control subjects. The effect of fructose on liver Pi and plasma urate was most pronounced in heterozygotes with gout (n = 3). Heterozygosity for HFI may predispose to hyperuricaemia.

  6. Quantitation of Localized 31P Magnetic Resonance Spectra Based on the Reciprocity Principle

    NASA Astrophysics Data System (ADS)

    Kreis, R.; Slotboom, J.; Pietz, J.; Jung, B.; Boesch, C.

    2001-04-01

    There is a need for absolute quantitation methods in 31P magnetic resonance spectroscopy, because none of the phosphorous-containing metabolites is necessarily constant in pathology. Here, a method for absolute quantitation of in vivo31P MR spectra that provides reproducible metabolite contents in institutional or standard units is described. It relies on the reciprocity principle, i.e., the proportionality between the B1 field map and the map of reception strength for a coil with identical relative current distributions in receive and transmit mode. Cerebral tissue contents of 31P metabolites were determined in a predominantly white matter-containing location in healthy subjects. The results are in good agreement with the literature and the interexamination coefficient of variance is better than that in most previous studies. A gender difference found for some of the 31P metabolites may be explained by different voxel composition.

  7. Kinetics of the in vivo31P 1H nuclear overhauser effect of the human-calf-muscle phosphocreatine resonance

    NASA Astrophysics Data System (ADS)

    Bachert, Peter; Bellemann, Matthias E.

    In 31P 1H double-resonance experiments in a 1.5 T whole-body MR system, we observed in vivo the truncated driven, transient, and steady-state 31P- 1H nuclear Overhauser effect of the phosphocreatine resonance in 31P MR spectra of human gastrocnemius muscle. Maximum signal enhancements of 0.52 ± 0.01, 0.20 ± 0.01, and 0.79 ± 0.02 were measured, respectively. Fitting the data with theoretical functions which solve the multispin Solomon equations for N protons (S spins) dipolar coupled to a 31P nucleus (I spin) yields cross-relaxation times {2}/{[Σ i=1-N σIS(i) ] } in the order of 20 s. In vivo experiments are feasible for studying relaxation mechanisms in coupled 31P 1H spin systems in intact tissue.

  8. Combined MRI and 31P-MRS Investigations of the ACTA1(H40Y) Mouse Model of Nemaline Myopathy Show Impaired Muscle Function and Altered Energy Metabolism

    PubMed Central

    Gineste, Charlotte; Le Fur, Yann; Vilmen, Christophe; Le Troter, Arnaud; Pecchi, Emilie; Cozzone, Patrick J.; Hardeman, Edna C.; Bendahan, David; Gondin, Julien

    2013-01-01

    Nemaline myopathy (NM) is the most common disease entity among non-dystrophic skeletal muscle congenital diseases. Mutations in the skeletal muscle α-actin gene (ACTA1) account for ∼25% of all NM cases and are the most frequent cause of severe forms of NM. So far, the mechanisms underlying muscle weakness in NM patients remain unclear. Additionally, recent Magnetic Resonance Imaging (MRI) studies reported a progressive fatty infiltration of skeletal muscle with a specific muscle involvement in patients with ACTA1 mutations. We investigated strictly noninvasively the gastrocnemius muscle function of a mouse model carrying a mutation in the ACTA1 gene (H40Y). Skeletal muscle anatomy (hindlimb muscles and fat volumes) and energy metabolism were studied using MRI and 31Phosphorus magnetic resonance spectroscopy. Skeletal muscle contractile performance was investigated while applying a force-frequency protocol (from 1–150 Hz) and a fatigue protocol (80 stimuli at 40 Hz). H40Y mice showed a reduction of both absolute (−40%) and specific (−25%) maximal force production as compared to controls. Interestingly, muscle weakness was associated with an improved resistance to fatigue (+40%) and an increased energy cost. On the contrary, the force frequency relationship was not modified in H40Y mice and the extent of fatty infiltration was minor and not different from the WT group. We concluded that the H40Y mouse model does not reproduce human MRI findings but shows a severe muscle weakness which might be related to an alteration of intrinsic muscular properties. The increased energy cost in H40Y mice might be related to either an impaired mitochondrial function or an alteration at the cross-bridges level. Overall, we provided a unique set of anatomic, metabolic and functional biomarkers that might be relevant for monitoring the progression of NM disease but also for assessing the efficacy of potential therapeutic interventions at a preclinical level. PMID:23613869

  9. [CNS metabolism in high-risk drug abuse, German version : Insights gained from (1)H- and (31)P MRS and PET].

    PubMed

    Bodea, S V

    2017-06-01

    High-risk drug consumption is a considerable problem for public health actors in industrialised countries. The latest trends show a market tendency towards diversification and increasing demand for high-purity synthetic drugs. Whilst most consumers seek medical help after cannabis use, it is high-risk drugs like cocaine, heroin and amphetamines that account for most of the 1000 drug-related deaths that occur in Germany every year. This article presents the most prominent in vivo cerebral metabolic information in cocaine, heroin and methamphetamine users provided by MRI spectroscopy and PET imaging. We reviewed the literature reporting neuroimaging studies of in vivo metabolic data for methamphetamine, cocaine and heroin consumption published up to March 2017. The search was conducted using PubMed with the following key words: methamphetamine, cocaine, heroin, MR spectroscopy, PET. MRI and PET are indispensable tools in gauging brain metabolic response to illegal drug abuse. Future breakthroughs in this field will most likely come from the investigation of novel neurotransmitter systems in PET and imaging phosphorus and carbon metabolites in MRI.

  10. Availability and metabolism of 77Se-methylseleninic acid compared simultaneously with those of three related selenocompounds.

    PubMed

    Suzuki, Kazuo T; Ohta, Yuki; Suzuki, Noriyuki

    2006-11-15

    Nutritional selenocompounds are considered to be transformed into the common intermediate selenide for utilization as selenoenzymes and/or for excretion as selenosugar and trimethylselenonium (TMSe). Therefore, selenocompounds can only be traced with a labeled selenium atom. Methylseleninic (MSA(IV)) has been proposed to be a third nutritional selenium source, the other two being inorganic selenocompounds and organic selenoamino acids, and to be a proximate selenochemical for producing the assumed biologically active form methylselenol. Here we applied a new tracer method to compare the availability and metabolism of MSA(IV) with those of three related selenocompounds under exactly identical host and tracing conditions. (82)Se-Selenite, (78)Se-selenate, (77)Se-MSA(IV) and (76)Se-methylselenonic acids (MSA(VI)) were simultaneously administered orally, each at the dose of 25 microg Se/kg body weight, to rats that had been depleted of endogenous natural abundance selenium with a single stable isotope ((80)Se). Time-related changes in the concentrations and/or distributions of the four labeled isotopes in the serum, liver, kidney, pancreas, lung and urine were determined simultaneously by inductively coupled argon plasma mass spectrometry (ICP MS) and/or HPLC-ICP MS. The availability with different isotope ratios was in the decreasing order of selenate>selenite=MSA(IV)>MSA(VI). Although selenate and MSA(VI) were distributed in organs and urine partly in their intact forms, MSA(IV) and selenite were not detected in the intact forms at all. MSA(IV) and MSA(VI) but not selenite or selenate produced TMSe in organs other than the liver, suggesting the transformation of MSA(IV) into methylselenol, and then either into selenide for the synthesis of selenoproteins and selenosugar or directly into TMSe. Thus, selenosugar and TMSe were produced widely in the organs. However, TMSe was not detected in the liver. The organ- and selenium source-specific production of TMSe was

  11. Metabolism of 76Se-methylselenocysteine compared with that of 77Se-selenomethionine and 82Se-selenite.

    PubMed

    Suzuki, Kazuo T; Doi, Chiaki; Suzuki, Noriyuki

    2006-12-01

    Se-Methylated selenoamino acids, Se-methylselenocysteine (MeSeCys) and selenomethionine (SeMet), are chemically inert storage forms of selenium in selenium-accumulators, and a nutritional and supplemental source. The metabolic pathway for MeSeCys was precisely traced by referring to those for SeMet and selenite by applying a new tracer method involving multiple homo-elemental stable isotopes. Male Wistar rats were depleted of endogenous natural abundance selenium with a single (80)Se-enriched isotope, and then (76)Se-MeSeCys, (77)Se-SeMet and (82)Se-selenite were orally administered simultaneously at 25 microg Se/kg body weight each. Organs and body fluids were obtained at 3, 6, 9 and 12 h, and 1 and 2 days later, and subjected to speciation analysis. The main characteristics of the metabolism were as follows; MeSeCys was incorporated into selenoprotein P slightly more than or at a comparable level to that of SeMet but less than that of selenite. MeSeCys and SeMet but not selenite was taken up by organs in their intact forms. MeSeCys and SeMet were delivered specifically to the pancreas and present in a form bound to an identical or similar protein. Trimethylselenonium (TMSe) was only produced from MeSeCys, i.e., not from SeMet or selenite, in the kidneys. Both selenosugars A and B of MeSeCys, SeMet and selenite origin were detected in the liver but only selenosugar B in the kidneys. These results suggest that MeSeCys can be a similar or better selenium source than SeMet, and supplies methylselenol much more efficiently in organs than SeMet and selenite. TMSe was produced much efficiently from MeSeCys than from SeMet and selenite, suggesting a role of methylselenol through the beta-lyase reaction in the metabolism of Se-methylated selenoamino acids.

  12. Advancement of 31P Magnetic Resonance Spectroscopy Using GRAPPA Reconstruction on a 3D Volume

    NASA Astrophysics Data System (ADS)

    Clevenger, Tony

    The overall objective of this research is to improve currently available metabolic imaging techniques for clinical use in monitoring and predicting treatment response to radiation therapy in liver cancer. Liver metabolism correlates with inflammatory and neoplastic liver diseases, which alter the intracellular concentration of phosphorus- 31 (31P) metabolites [1]. It is assumed that such metabolic changes occur prior to physical changes of the tissue. Therefore, information on regional changes of 31P metabolites in the liver, obtained by Magnetic Resonance Spectroscopic Imaging (MRSI) [1,2], can help in diagnosis and follow-up of various liver diseases. Specifically, there appears to be an immediate need of this technology for both the assessment of tumor response in patients with Hepatocellular Carcinoma (HCC) treated with Stereotactic Body Radiation Therapy (SBRT) [3--5], as well as assessment of radiation toxicity, which can result in worsening liver dysfunction [6]. Pilot data from our lab has shown that 31P MRSI has the potential to identify treatment response five months sooner than conventional methods [7], and to assess the biological response of liver tissue to radiation 24 hours post radiation therapy [8]. While this data is very promising, commonly occurring drawbacks for 31P MRSI are patient discomfort due to long scan times and prone positioning within the scanner, as well as reduced data quality due to patient motion and respiration. To further advance the full potential of 31P MRSI as a clinical diagnostic tool in the management of liver cancer, this PhD research project had the following aims: I) Reduce the long acquisition time of 3D 31P MRS by formulating and imple- menting an appropriate GRAPPA undersampling scheme and reconstruction on a clinical MRI scanner II) Testing and quantitative validation of GRAPPA reconstruction on 3D 31P MRSI on developmental phantoms and healthy volunteers At completion, this work should considerably advance 31P MRSI

  13. TLC and 31P-NMR analysis of low polarity phospholipids.

    PubMed

    Vyssotski, Mikhail; MacKenzie, Andrew; Scott, Dawn

    2009-04-01

    High-performance TLC and (31)P-NMR were assessed as methods of observing the presence of numerous low polarity phospholipids: bis-phosphatidic acid (BPA), semi-lyso bis-phosphatidic acid (SLBPA), N-acyl phosphatidylethanolamine (NAPE), N-(1,1-dimethyl-3-oxo-butyl)-phosphatidylethanolamine (diacetone adduct of PE, DOBPE), N-acetyl PE, phosphatidylmethanol (PM), phosphatidylethanol (PEt), phosphatidyl-n-propanol (PP), phosphatidyl-n-butanol (PB). Both techniques are non-discriminative and do not require the prior isolation of individual lipids. It appears that 2D TLC is superior to (31)P NMR in the analysis of low polarity phospholipids. All phosphatidylalcohols were well separated by 2D TLC. However, some compounds which can present difficulty in separation by 2D-TLC (e.g., SLBPA and NAPE; or DOBPE and N-acetyl PE) were easily distinguished using (31)P NMR so the methods are complimentary. A disadvantage of 2D TLC is that Rf values can vary with different brands and batches of TLC plates. The chemical shifts of (31)P NMR were less variable, and so a library of standards may not be necessary for peak identification. Another advantage of (31)P NMR is the ease of quantification of phospholipids. The applicability of the methods was tested on natural extracts of fish brain and cabbage stem.

  14. (31)P solid-state NMR based monitoring of permeation of cell penetrating peptides into skin.

    PubMed

    Desai, Pinaki R; Cormier, Ashley R; Shah, Punit P; Patlolla, Ram R; Paravastu, Anant K; Singh, Mandip

    2014-02-01

    The main objective of the current study was to investigate penetration of cell penetrating peptides (CPPs: TAT, R8, R11, and YKA) through skin intercellular lipids using (31)P magic angle spinning (MAS) solid-state NMR. In vitro skin permeation studies were performed on rat skin, and sections (0-60, 61-120, and 121-180μm) were collected and analyzed for (31)P NMR signal. The concentration-dependent shift of 0, 25, 50, 100, and 200mg/ml of TAT on skin layers, diffusion of TAT, R8, R11, and YKA in the skin and time dependent permeation of R11 was measured on various skin sections using (31)P solid-state NMR. Further, CPPs and CPP-tagged fluorescent dye encapsulate liposomes (FLip) in skin layers were tagged using confocal microscopy. The change in (31)P NMR chemical shift was found to depend monotonically on the amount of CPP applied on skin, with saturation behavior above 100mg/ml CPP concentration. R11 and TAT caused more shift in solid-state NMR peaks compared to other peptides. Furthermore, NMR spectra showed R11 penetration up to 180μm within 30min. The results of the solid-state NMR study were in agreement with confocal microscopy studies. Thus, (31)P solid-state NMR can be used to track CPP penetration into different skin layers. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. 31P Solid-state NMR based monitoring of permeation of cell penetrating peptides into skin

    PubMed Central

    Desai, Pinaki R.; Cormier, Ashley R.; Shah, Punit P.; Patlolla, Ram R.; Paravastu, Anant K.; Singh, Mandip

    2013-01-01

    The main objective of the current study was to investigate penetration of cell penetrating peptides (CPPs: TAT, R8, R11 and YKA) through skin intercellular lipids using 31P magic angle spinning (MAS) solid-state NMR. In vitro skin permeation studies were performed on rat skin, sections (0–60, 61–120 and 121–180 µm) were collected and analyzed for 31P NMR signal. The concentration dependent shift of 0, 25, 50, 100 and 200 mg/ml of TAT on skin layers, diffusion of TAT, R8, R11 and YKA in the skin and time dependent permeation of R11 was measured on various skin sections using 31P solid-state NMR. Further, CPPs and CPP-tagged fluorescent dye encapsulate liposomes (FLip) in skin layers were tagged using confocal microscopy. The change in 31P NMR chemical shift was found to depend monotonically on the amount of CPP applied on skin, with saturation behavior above 100 mg/ml CPP concentration. R11 and TAT caused more shift in solid-state NMR peaks compared to other peptides. Furthermore, NMR spectra showed R11 penetration up to 180 µm within 30 min. The results of the solid-state NMR study were in agreement with confocal microscopy studies. Thus, 31P solid-state NMR can be used to track CPP penetration into different skin layers. PMID:23702274

  16. Skeletal muscle ATP turnover by 31P magnetic resonance spectroscopy during moderate and heavy bilateral knee extension

    PubMed Central

    Cannon, Daniel T; Bimson, William E; Hampson, Sophie A; Bowen, T Scott; Murgatroyd, Scott R; Marwood, Simon; Kemp, Graham J; Rossiter, Harry B

    2014-01-01

    During constant-power high-intensity exercise, the expected increase in oxygen uptake () is supplemented by a  slow component (), reflecting reduced work efficiency, predominantly within the locomotor muscles. The intracellular source of inefficiency is postulated to be an increase in the ATP cost of power production (an increase in P/W). To test this hypothesis, we measured intramuscular ATP turnover with 31P magnetic resonance spectroscopy (MRS) and whole-body during moderate (MOD) and heavy (HVY) bilateral knee-extension exercise in healthy participants (n = 14). Unlocalized 31P spectra were collected from the quadriceps throughout using a dual-tuned (1H and 31P) surface coil with a simple pulse-and-acquire sequence. Total ATP turnover rate (ATPtot) was estimated at exercise cessation from direct measurements of the dynamics of phosphocreatine (PCr) and proton handling. Between 3 and 8 min during MOD, there was no discernable (mean ± SD, 0.06 ± 0.12 l min−1) or change in [PCr] (30 ± 8 vs. 32 ± 7 mm) or ATPtot (24 ± 14 vs. 17 ± 14 mm min−1; each P = n.s.). During HVY, the was 0.37 ± 0.16 l min−1 (22 ± 8%), [PCr] decreased (19 ± 7 vs. 18 ± 7 mm, or 12 ± 15%; P < 0.05) and ATPtot increased (38 ± 16 vs. 44 ± 14 mm min−1, or 26 ± 30%; P < 0.05) between 3 and 8 min. However, the increase in ATPtot (ΔATPtot) was not correlated with the during HVY (r2 = 0.06; P = n.s.). This lack of relationship between ΔATPtot and , together with a steepening of the [PCr]– relationship in HVY, suggests that reduced work efficiency during heavy exercise arises from both contractile (P/W) and mitochondrial sources (the O2 cost of ATP resynthesis; P/O). PMID:25281731

  17. sup 31 P NMR analysis of coal moieties bearing -OH, -NH, and -SH functions

    SciTech Connect

    Verkade, J.G.

    1991-08-31

    NMR reagents for the speciation and quantitation of labile-hydrogen functional groups and sulfur groups in coal ligands have been synthesized and evaluated. These reagents, which contain the NMR-active nuclei {sup 31}p, {sup 119}Sn or {sup 195}pt, were designed to possess improved chemical shift resolution over reagents reported in the literature. Our efforts were successful in the case of the new {sup 31}p and {sup 119}Sn reagents we developed, but the {sup 195}pt work on sulfur groups was only partially successful in as much as the grant came to a close and was not renewed. Our success with {sup 31}P and {sup 119}Sn NMR reagents came to the attention of Amoco and they have recently expressed interest in further supporting that work. A further measure of the success of our efforts can be seen in the nine publications supported by this grant which are cited in the reference list.

  18. High-resolution dynamic (31) P-MRSI using a low-rank tensor model.

    PubMed

    Ma, Chao; Clifford, Bryan; Liu, Yuchi; Gu, Yuning; Lam, Fan; Yu, Xin; Liang, Zhi-Pei

    2017-08-01

    To develop a rapid (31) P-MRSI method with high spatiospectral resolution using low-rank tensor-based data acquisition and image reconstruction. The multidimensional image function of (31) P-MRSI is represented by a low-rank tensor to capture the spatial-spectral-temporal correlations of data. A hybrid data acquisition scheme is used for sparse sampling, which consists of a set of "training" data with limited k-space coverage to capture the subspace structure of the image function, and a set of sparsely sampled "imaging" data for high-resolution image reconstruction. An explicit subspace pursuit approach is used for image reconstruction, which estimates the bases of the subspace from the "training" data and then reconstructs a high-resolution image function from the "imaging" data. We have validated the feasibility of the proposed method using phantom and in vivo studies on a 3T whole-body scanner and a 9.4T preclinical scanner. The proposed method produced high-resolution static (31) P-MRSI images (i.e., 6.9 × 6.9 × 10 mm(3) nominal resolution in a 15-min acquisition at 3T) and high-resolution, high-frame-rate dynamic (31) P-MRSI images (i.e., 1.5 × 1.5 × 1.6 mm(3) nominal resolution, 30 s/frame at 9.4T). Dynamic spatiospectral variations of (31) P-MRSI signals can be efficiently represented by a low-rank tensor. Exploiting this mathematical structure for data acquisition and image reconstruction can lead to fast (31) P-MRSI with high resolution, frame-rate, and SNR. Magn Reson Med 78:419-428, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  19. Monitoring changes of paramagnetically-shifted 31P signals in phospholipid vesicles

    NASA Astrophysics Data System (ADS)

    Joyce, Rebecca E.; Williams, Thomas L.; Serpell, Louise C.; Day, Iain J.

    2016-03-01

    Phospholipid vesicles are commonly used as biomimetics in the investigation of the interaction of various species with cell membranes. In this letter we present a 31P NMR investigation of a simple vesicle system using a paramagnetic shift reagent to probe the inner and outer layers of the lipid bilayer. Time-dependent changes in the 31P NMR signal are observed, which differ whether the paramagnetic species is inside or outside the vesicle, and on the choice of buffer solution used. An interpretation of these results is given in terms of the interaction of the paramagnetic shift reagent with the lipids.

  20. Organic matter and pH affect the analysis efficiency of (31)P-NMR.

    PubMed

    Zhang, Wenqiang; Jin, Xin; Rong, Nan; Li, Jie; Shan, Baoqing

    2016-05-01

    Solution (31)P nuclear magnetic resonance spectroscopy ((31)P-NMR) is a useful method to analyze organic phosphorus (Po), but a general procedure for the analysis method is lacking. The authors used solution (31)P-NMR, which was found to be an effective method for analysis of Po in Haihe River sediment, to analyze the Po in the surface sediment in Eastern China at the regional scale, and found that the NaOH-ethylenediaminetetraacetic acid (EDTA) extraction rate was affected by environmental factors. At the regional scale, the extraction rate showed a positive relationship with loss on ignition, when the extraction rate was lower than 60%. The extraction rate had no relationship with the loss on ignition when the extraction rate was higher than 60%. The extraction rate showed a negative relationship with pH, which means that the extraction rate was higher in acidic sediment and lower in alkaline sediment. The ratio of TC/TN (the ratio of total carbon to total nitrogen) was considered to represent the origin of organic matter in the sediment. The extraction rate was high when the TC/TN ratio was lower than 20, meanwhile the extraction rate decreased as the TC/TN ratio increased. The results show that the origin of organic matter in sediment significantly affects the NaOH-EDTA extraction rate. This study will give theoretical support for building an effective and general solution (31)P-NMR analysis method. Copyright © 2015. Published by Elsevier B.V.

  1. Comparison of phosphorus forms in three extracts of dairy feces by solution 31P NMR analysis

    USDA-ARS?s Scientific Manuscript database

    Using solution 31P NMR spectroscopy, we compared three extractants, deionized water, sodium acetate buffer (pH 5.0) with fresh sodium dithionite (NaAc-SD), and 0.25 M NaOH-0.05 M EDTA (NaOH-EDTA), for the profile of P compounds in two dairy fecal samples. Phosphorus extracted was 35% for water, and...

  2. Nuclear spin coherence of neutral 31P donors in isotopically enriched 28Si

    NASA Astrophysics Data System (ADS)

    Petersen, E. S.; Tyryshkin, A. M.; Lyon, S. A.; Tojo, S.; Itoh, K. M.; Thewalt, M. L. W.; Riemann, H.; Abrosimov, N. V.; Becker, P.; Pohl, H.-J.

    2014-03-01

    In natural silicon the nuclear spin coherence of neutral 31P donors is limited to about 1 second by flip-flopping 29Si nuclear spins. Here we eliminate this process by using isotopically enriched 28Si with 50 ppm of 29Si. This allows us to examine other processes which may decohere the 31P nuclear spins. We use X-band pulsed ENDOR at 1.7 K to examine isotopically enriched Si crystals with donor concentrations from 1014 to 4x1015 P/cm3 and find a dependence of 31P nuclear spin coherence time on donor concentration. The measured nuclear spin echo decays are fit by a stretched exponential function, exp(-(t/T2)n) , with n ranging from 0.7 to 1. This differs from n of about 2 commonly seen for spectral diffusion due to indirect spin flip-flops. The measured T2 times decrease significantly when the donor concentration increases, changing from 8 s at 1014 to 0.2 s at 4x1015 P/cm3. From the observed donor concentration dependence at higher densities, we conclude that direct electron spin flip-flops are responsible for 31P donor nuclear spin decoherence. This work was supported in part by NSF through the Materials World Network program (DMR-1107606) and the Princeton MRSEC (DMR-0819860), and in part by the U.S. Army Research Office (W911NF-13-1-0179).

  3. /sup 31/P-NMR differentiation between intracellular phosphate pools in Cosmarium (chlorophyta)

    SciTech Connect

    Elgavish, A.; Elgavish, G.A.

    1980-09-01

    /sup 31/P nuclear magnetic resonance (NMR) spectroscopy of intact Cosmarium sp. cells is presented as a suitable tool for the differentiation of intracellular accumulation pools of polyphosphates. The cold trichloroacetic acid (TCA) insoluble fraction is shown to contain most of the total cellular phosphate in the phosphate rich Cosmarium cells. Moreover, evidence from a /sup 31/P-NMR study and electron microscopic observations of cold TCA treated Cosmarium cells indicate that this fraction consists mostly of polyphosphates which seem to retain the native morphological structure observed in the untreated cells. The determination of orthophosphate in the hot water extract of Cosmarium cells did not measure the polyphosphate pools. Determination of total phosphorus content in the hot water extract rendered a value three times higher than the frequently used orthophosphate determination procedure. However, as revealed by the /sup 31/P-NMR spectra and the chemical analyses of the extract and of the treated cells, even total phosphorus in the extract measured only 30% of the total cellular phosphorus. /sup 31/P-NMR enabled the unequivocal chemical identification of the major phosphate compounds in the hot water extract (Surplus P) as orthophosphate and polyphosphates of about 10 phosphate units chainlength. More than 70% of the accumulation pool of polyphosphates was still in the cells after extraction. However, the electron microscopy study revealed that the native granular structure of polyphosphates had been destroyed by the hot water extraction procedure.

  4. Overestimation of orthophosphate monoesters in lake sediment by solution (31)P-NMR analysis.

    PubMed

    Zhang, Wenqiang; Jin, Xin; Tang, Wenzhong; Shan, Baoqing

    2017-09-30

    Solution (31)P nuclear magnetic resonance spectroscopy ((31)P-NMR) is a useful method for analyzing organic phosphorus (Po). Unfortunately, the extraction conditions, which are highly alkaline and require long extraction times, make this analysis less effective. In this research, according to the lability of orthophosphate monoesters (mono-Po) and orthophosphate diesters (diesters-Po), we verified the hypothesized overestimation of mono-Po in lake sediment using solution (31)P-NMR. We set three scenes to redistribute the mono-Po and diesters-Po. Six components, including eight mono-Po species, were detected in the NaOH-EDTA extracts of sediment samples using (31)P-NMR. The results showed that mono-Po (212.7 mg kg(-1)) was the dominant Po in the surface sediment. In the three scenes, mono-Po decreased from 212.7 to 112.0 mg kg(-1), and diesters-Po increased from 31.9 to 132.7 mg kg(-1). The ratio of mono-Po to diesters-Po increased from 6.7 to 0.8. Therefore, we deduced that the concentration of mono-Po was overestimated, while that of diesters-Po was underestimated, in most research because of the high pH and long extraction process. Diesters-Po might be an important labile P source during the P "exhausted" period.

  5. [Optimizing the method for 31P-NMR analysis of organic phosphorus from wetland sediments].

    PubMed

    Lu, Jin; Wang, Hai-Wen; Hao, Hong; Gao, Bo; Jia, Jian-Li

    2013-11-01

    Solution 31P-Nuclear Magnetic Resonance (NMR) is an analysis technology which has been an effective means for the analysis of environmental organic phosphorus. However, the method is rarely applied in the study of wetlands so that the corresponding researches about wetland sediment sample preparation method also very deficient. The present study was aimed to find the most suitable sample preparation method for 31P-NMR analysis of the artificial wetland sediments, using different extractant (NaOH or 0.25 mol x L(-1) NaOH + 0.05 mol x L(-1) EDTA as main extractant, and 1M HCl as pre-extractant or not), sample to extractant ratio (1 : 8 or 1 : 10), centrifugation conditions and scans time and so on. The results showed that the best 31P-NMR spectrum could be obtained with freeze-ried, ground and sieved sediments, 1M HCl as pre-extractant for 16 h, NaOH + 0.05 mol x L(-1) EDTA as main extractant for 16 h, extraction ratio of 1 : 8, and low temperature and high-speed centrifugation (4 degrees C, 10 000 r x min(-1) for 30 min) for avoiding hydrolysis of certain components. Besides, choosing much longer NMR scan time, as 14-16 h (scans about 25 000 times), could get more complete spectral signals spectrum. And finally, four kinds of P-compounds (orthophosphate, orthophosphate monoesters, orthophosphate diesters and pyrophosphate) were detected in the NMR spectrum. But neither polyphosphate nor phosphonates was not found in all these experiments, which need further study. Compared with the traditional chemical analysis method, 31P-NMR method of sample preparation is relatively simple. Then it is less destructive with components distinguished completely. Using 31P-NMR technology, the cognition of wetland phosphorus cycle, especially organophosphate, will be expected to get new breakthrough.

  6. 31P-dephased, 13C-detected REDOR for NMR crystallography at natural isotopic abundance

    NASA Astrophysics Data System (ADS)

    Greenwood, Alexander I.; Clay, Mary C.; Rienstra, Chad M.

    2017-05-01

    Typically, the process of NMR-based structure determination relies on accurately measuring a large number of internuclear distances to serve as restraints for simulated annealing calculations. In solids, the rotational-echo double-resonance (REDOR) experiment is a widely used approach to determine heteronuclear dipolar couplings corresponding to distances usually in the range of 1.5-8 Å. A challenge in the interpretation of REDOR data is the degeneracy of symmetric subunits in an oligomer or equivalent molecules in a crystal lattice, which produce REDOR trajectories that depend explicitly on two or more distances instead of one. This degeneracy cannot be overcome by either spin dilution (for molecules containing 31P, 19F and other highly abundant nuclei) or selective pulses (in the case where there is chemical shift degeneracy). For small, crystalline molecules, such as phosphoserine, we demonstrate that as many as five inter-molecular distances must be considered to model 31P-dephased REDOR data accurately. We report excellent agreement between simulation and experiment once lattice couplings, 31P chemical shift anisotropy, and radio-frequency field inhomogeneity are all taken into account. We also discuss the systematic inaccuracies that may result from approximations that consider only the initial slope of the REDOR trajectory and/or that utilize a two- or three-spin system. Furthermore, we demonstrate the applicability of 31P-dephased REDOR for validation or refinement of candidate crystal structures and show that this approach is especially informative for NMR crystallography of 31P-containing molecules.

  7. Low-lying levels of 77Se studied by thermal neutron capture and evidence for a new term in the E2 operator of RQM (IBM)

    NASA Astrophysics Data System (ADS)

    Tokunaga, Y.; Seyfarth, H.; Meyer, R. A.; Schult, O. W. B.; Börner, H. G.; Barreau, G.; Faust, H. R.; Schreckenbach, K.; Brant, S.; Paar, V.; Vouk, M.; Vretenar, D.

    1985-06-01

    A high-resolution study of the 76Se(n, γ) reaction was carried out with curved-crystal and pair spectrometers and conversion electrons were measured following slow-neutron capture. The resulting data yield very precise level energies and spin and parity assignments for most of the levels. The neutron separation energy of 77Se was measured as 7418.85 ± 0.07 keV. The experimental data were compared with theoretical results for the level energies in 77Se and the E2, M1 and E1 branching ratios obtained from the SU(6) particle-vibration model (PTQM). We used 76Se as a slightly perturbed SU(5) vibrational core and the particle-vibration interaction strengths from the PTQM calculation for 75Se. In this frame there is evidence for a Δn = 2 term in the E2 operator. This term has not been included so far in TQM and IBM calculations.

  8. In situ determination of lignin phenolics and wood solubility in imidazolium chlorides using (31)P NMR.

    PubMed

    King, Alistair W T; Zoia, Luca; Filpponen, Ilari; Olszewska, Anna; Xie, Haibo; Kilpeläinen, Ilkka; Argyropoulos, Dimitris S

    2009-09-23

    Corn stover, Norway spruce, and Eucalyptus grandis were pulverized to different degrees. These samples were subjected to quantitative analyses, upon the basis of predissolution into the imidazolium chloride-based ionic liquids [amim]Cl and [bnmim]Cl followed by labeling of hydroxyl groups as phosphite esters and quantitative (31)P NMR analysis. Analysis of different pulverization degrees provided semiempirical data to chart the solubility of Norway spruce in these ionic liquids. Further method refinment afforded an optimized method of analysis of the lignin phenolic functionalities, without prior isolation of the lignin from the fiber. The lignin in these samples was further enriched using cellulase and acidolysis treatments, allowing for comparison with the fibrous samples. Analysis of all samples charts the polymerized-monomer availability for each stage of the treatment. Conditions required for adequate signal-to-noise ratios in the (31)P NMR analysis were established with a notable improvement observed upon the lignin enrichment steps.

  9. Erythrocytes in muscular dystrophy. Investigation with 31P nuclear magnetic resonance spectroscopy

    SciTech Connect

    Sarpel, G.; Lubansky, H.J.; Danon, M.J.; Omachi, A.

    1981-05-01

    Phosphorus 31 nuclear magnetic resonance (31P NMR) signals were recorded from intact human erythrocytes for 16 hours. Total phosphate concentration, which was estimated as the sum of the individual 31P signals, was 25% lower in erythrocytes from men with myotonic dystrophy than in control erythrocytes. The inorganic-phosphate fraction contained the highest average phosphate concentration over the 16-hour period, and made the major contribution to the difference in total phosphate between the two groups. This result was not observed in erythrocytes from either women with myotonic dystrophy or patients with Duchenne's dystrophy and may be due to a change in cell membrane permeability to inorganic phosphate, which lead to lower steady-state concentrations of the intracellular phosphates.

  10. Erythrocytes in muscular dystrophy. Investigation with /sup 31/P nuclear magnetic resonance spectroscopy

    SciTech Connect

    Sarpel, G.; Lubansky, H.J.; Danon, M.J.; Omachi, A.

    1981-05-01

    Phosphorus 31 nuclear magnetic resonance (/sup 31/P NMR) signals were recorded from intact human erythrocytes for 16 hours. Total phosphate concentration, which was estimated as the sum of the individual /sup 31/P signals, was 25% lower in erythrocytes from men with myotonic dystrophy than in control erythrocytes. The inorganic-phosphate fraction contained the highest average phosphate concentration over the 16-hour period, and made the major contribution to the difference in total phosphate between the two groups. This result was not observed in erythrocytes from either women with myotonic dystrophy or patients with Duchenne's dystrophy and may be due to a change in cell membrane permeability to inorganic phosphate, which leads to lower steady-state concentrations of the intracellular phosphates.

  11. Excitation functions for actinides produced in the interactions of sup 31 P with sup 248 Cm

    SciTech Connect

    Leyba, J.D.; Henderson, R.A.; Hall, H.L.; Czerwinski, K.R.; Kadkhodayan, B.A.; Kreek, S.A.; Brady, E.K.; Gregorich, K.E.; Lee, D.M.; Nurmia, M.J.; Hoffman, D.C. Nuclear Science Division, Lawrence Berkeley Laboratory, University of California, Berkeley, California )

    1991-11-01

    Excitation functions have been measured for the production of various isotopes of Bk, Cf, Es, and Fm from the interactions of 174- and 239-MeV {sup 31}P projectiles with {sup 248}Cm. The isotopic distributions were symmetric and displayed full widths at half maximum of 2.5, 2.5, and 2.25 mass units for Bk, Cf, and Fm, respectively. The maxima of the isotopic distributions occur for those reaction channels which involve the exchange of the fewest number of nucleons between the target and projectile for which the calculated excitation energy is a positive quantity. The maxima of the excitation functions occur at those projectile energies which are consistent with the calculated reaction barriers based upon a binary reaction mechanism. The effects of the odd proton in the {sup 31}P projectile on the final isotopic distributions are discussed.

  12. CD and 31P NMR studies of tachykinin and MSH neuropeptides in SDS and DPC micelles

    NASA Astrophysics Data System (ADS)

    Schneider, Sydney C.; Brown, Taylor C.; Gonzalez, Javier D.; Levonyak, Nicholas S.; Rush, Lydia A.; Cremeens, Matthew E.

    2016-02-01

    Secondary structural characteristics of substance P (SP), neurokinin A (NKA), neurokinin B (NKB), α-melanocyte stimulating hormone peptide (α-MSH), γ1-MSH, γ2-MSH, and melittin were evaluated with circular dichroism in phosphite buffer, DPC micelles, and SDS micelles. CD spectral properties of γ1-MSH and γ2-MSH as well as 31P NMR of DPC micelles with all the peptides are reported for the first time. Although, a trend in the neuropeptide/micelle CD data appears to show increased α-helix content for the tachykinin peptides (SP, NKA, NKB) and increased β-sheet content for the MSH peptides (α-MSH, γ1-MSH, γ2-MSH) with increasing peptide charge, the lack of perturbed 31P NMR signals for all neuropeptides could suggest that the reported antimicrobial activity of SP and α-MSH might not be related to a membrane disruption mode of action.

  13. 31P NMR Characterization of Tricin and Its Structurally Similar Flavonoids

    DOE PAGES

    Li, Mi; Pu, Yunqiao; Tschaplinski, Timothy J.; ...

    2017-04-24

    Tricin, a flavonoid metabolite, has been recently identified as a component of lignin in select monocot plants. This finding has initiated consideration on updating the lignin biosynthesis pathway. Here, we report a rapid method of determination of tricin in corn stover lignin, based on 31P nuclear magnetic resonance (NMR) spectroscopy by phosphitylating with 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane (TMDP). Nine other flavonoids, with similar structure to tricin, have also been examined using the current method. The application of 31P NMR enables rapid identification of tricin-like flavonoids in the heterogeneous lignin polymer. The well resolved spectroscopic peaks from these derivatized flavonoids and lignin functional groupsmore » provide important information for the determination of flavonoids individually or their association with lignin.« less

  14. Characterization of two forms of cadmium phosphide by magic-angle spinning 31P NMR.

    PubMed

    Holl, S M; Kowalewski, T; Schaefer, J

    1996-02-01

    Annealing of commercial grade cadmium phosphide (CD3P2) at 600 K produces a material which, in magic-angle spinning spin-lattice 31P NMR relaxation experiments, has broad lines and multiple T1 values. By contrast, sublimation at 900 K results in a crystalline material with narrow lines and a single T1. However, both materials have the same Cd-P lattice spacings as determined by rotational-echo, double-resonance 31P NMR with 113Cd dephasing. Both materials also have closely similar X-ray diffraction powder patterns. These results are interpreted in terms of a distribution of lattice vacancies in the annealed material, creating structural heterogeneity but with no substantial change in lattice parameters from those of the sublimed cadmium phosphide.

  15. In-depth investigation on quantitative characterization of pyrolysis oil by 31P NMR

    DOE PAGES

    Ben, Haoxi; Ferrell, III, Jack R.

    2016-01-29

    The characterization of different heteroatom functional groups by employing 31P NMR has been developed for almost 30 years. In this study, an in-depth investigation of this commonly used method has been accomplished for the analysis of pyrolysis oil. Several commonly used internal standards for 31P NMR have been examined by in situ monitoring. The results indicated that endo-N-hydroxy-5-norbornene-2,3-dicarboximide (NHND) is not stable after a long period of storage or experiment (>12 hours), but both cyclohexanol and triphenylphosphine oxide (TPPO) can be used as internal standards if a long experiment or storage is required. The pyrolysis oil has also been investigatedmore » by both short time (16 hours) in situ monitoring and long time (14 days) ex situ monitoring. The results showed that aliphatic OH, carboxylic acids and water contents are not very stable after 2 hours, and thus a short time of preparation, storage, and experiment need to be considered to ensure a precise quantitative measurement. The decomposition products are still unclear, but some preliminary investigations for different acids, (e.g. formic acid) have been accomplished. The results indicated that the aromatic carboxylic acids (benzoic acid and vanillic acid) are more stable than formic acid and acetic acid. Interestingly, the formic acid will even decompose to some other compounds at the very beginning of the in situ monitoring test. Further characterization found that water is one of the major products for the decomposition of formic acid in the 31P NMR solution. Finally, as far as we know, this is the first report on such time-dependent changes when using 31P NMR to analyze the pyrolysis oil, and these results show that proper application of this method is essential to achieve reliable quantitative data.« less

  16. Pyrolysis temperature affects phosphorus transformation in biochar: Chemical fractionation and (31)P NMR analysis.

    PubMed

    Xu, Gang; Zhang, You; Shao, Hongbo; Sun, Junna

    2016-11-01

    Phosphorus (P) recycling or reuse by pyrolyzing crop residue has recently elicited increased research interest. However, the effects of feedstock and pyrolysis conditions on P species have not been fully understood. Such knowledge is important in identifying the agronomic and environmental uses of biochar. Residues of three main Chinese agricultural crops and the biochars (produced at 300°C-600°C) derived from these crops were used to determine P transformations during pyrolysis. Hedley sequential fractionation and (31)P NMR analyses were used in the investigation. Our results showed that P transformation in biochar was significantly affected by pyrolysis temperature regardless of feedstock (Wheat straw, maize straw and peanut husk). Pyrolysis treatment transformed water soluble P into a labile (NaHCO3-Pi) or semi-labile pool (NaOH-Pi) and into a stable pool (Dil. HCl P and residual-P). At the same time, organic P was transformed into inorganic P fractions which was identified by the rapid decomposition of organic P detected with solution (31)P NMR. The P transformation during pyrolysis process suggested more stable P was formed at a higher pyrolysis temperature. This result was also evidenced by the presence of less soluble or stable P species, such as such as poly-P, crandallite (CaAl3(OH)5(PO4)2) and Wavellite (Al3(OH)3(PO4)2·5H2O), as detected by solid-state (31)P NMR in biochars formed at a higher pyrolysis temperature. Furthermore, a significant proportion of less soluble pyrophosphate was identified by solution (2%-35%) and solid-state (8%-53%) (31)P NMR, which was also responsible for the stable P forms at higher pyrolysis temperature although their solubility or stability requires further investigation. Results suggested that a relatively lower pyrolysis temperature retains P availability regardless of feedstock during pyrolysis process. Copyright © 2016. Published by Elsevier B.V.

  17. Intermediate valence behavior of Yb2Ni12P7 studied by using 31P NMR

    NASA Astrophysics Data System (ADS)

    Koyama, T.; Sugiura, K.; Ueda, K.; Mito, T.; Kohara, T.; Satoh, R.; Tsuchiya, K.; Nakano, T.; Takeda, N.

    2013-08-01

    The Yb-based heavy-fermion compound Yb2Ni12P7 with a hexagonal Zr2Fe12P7-type crystal structure was investigated by using the 31P nuclear magnetic resonance (NMR) technique. The complicated NMR line changes its shape gradually with decreasing temperature, implying the presence of some Knight shift components. The temperature dependences of the Knight shift and the nuclear spin-lattice relaxation rate 1/ T 1 suggest the delocalization of 4 f electrons.

  18. Biochemical phosphates observed using hyperpolarized (31)P in physiological aqueous solutions.

    PubMed

    Nardi-Schreiber, Atara; Gamliel, Ayelet; Harris, Talia; Sapir, Gal; Sosna, Jacob; Gomori, J Moshe; Katz-Brull, Rachel

    2017-08-24

    The dissolution-dynamic nuclear polarization technology had previously enabled nuclear magnetic resonance detection of various nuclei in a hyperpolarized state. Here, we show the hyperpolarization of (31)P nuclei in important biological phosphates (inorganic phosphate and phosphocreatine) in aqueous solutions. The hyperpolarized inorganic phosphate showed an enhancement factor >11,000 (at 5.8 T, 9.3% polarization) in D2O (T1 29.4 s). Deuteration and the solution composition and pH all affected the lifetime of the hyperpolarized state. This capability opens up avenues for real-time monitoring of phosphate metabolism, distribution, and pH sensing in the live body without ionizing radiation. Immediate changes in the microenvironment pH have been detected here in a cell-free system via the chemical shift of hyperpolarized inorganic phosphate. Because the (31)P nucleus is 100% naturally abundant, future studies on hyperpolarized phosphates will not require expensive isotope labeling as is usually required for hyperpolarization of other substrates.Real-time monitoring of phosphate metabolism and distribution in the live body without ionizing radiation is highly desirable. Here, the authors show dissolution-dynamic nuclear polarization technology can enable nuclear magnetic resonance detection of hyperpolarized (31)P of important biological phosphates in aqueous solutions.

  19. [Muscular energetic metabolism study in athletes using 31P-MRS].

    PubMed

    Santos, Maria Gisele dos; González de Suso, Jose Manuel; Moreno, Angel; Cabanas, Miquel; Arus, Carles

    2004-01-01

    The aim of this study was to characterize the muscular reservoirs of phosphorilated energetic components of athletes using 31P-MRS. The sample was formed by 14 elite athletes from the Center for High Sportive Performance (CAR, Sant Cugat del Vallés, Spain). The pattern of the phosphorilated metabolites was measured from the muscle vastus medialis by 31P-MRS. Oral supplementation of 20 g of Creatine monohydrate was given during 14 days. Two groups of athletes were formed according to their physical characteristics (weight, height, body mass index, maximum O2 uptake). The first group received a placebo (maltodextrine), while the second group received a diet of creatine supplement. The exercise was performed inside the resonance tunnel with a frequency of 60 RPM with both legs. The results showed that significant decrease occurred in phosphocreatine (PCr), inorganic phosphate (Pi) and intracellular pH after supplementation. It was concluded that the exercise performed by the long distance runners recruited in this study, detected by 31P-MRS, reduced the consumption of PCr during exercise owing to creatine supplementation diet.

  20. Assessing crop residue phosphorus speciation using chemical fractionation and solution 31P nuclear magnetic resonance spectroscopy.

    PubMed

    Noack, Sarah R; Smernik, Ronald J; McBeath, Therese M; Armstrong, Roger D; McLaughlin, Mike J

    2014-08-01

    At physiological maturity, nutrients in crop residues can be released to the soil where they are incorporated into different labile and non-labile pools while the remainder is retained within the residue itself. The chemical speciation of phosphorus (P) in crop residues is an important determinant of the fate of this P. In this study, we used chemical fractionation and (31)P nuclear magnetic resonance (NMR) spectroscopy, first separately and then together, to evaluate the P speciation of mature oat (Avena sativa) residue. Two water extracts (one employing shaking and the other sonication) and two acid extracts (0.2N perchloric acid and 10% trichloroacetic acid) of these residues contained similar concentrations of orthophosphate (molybdate-reactive P determined by colorimetry) as NaOH-EDTA extracts of whole plant material subsequently analysed by solution (31)P NMR spectroscopy. However, solution (31)P NMR analysis of the extracts and residues isolated during the water/acid extractions indicated that this similarity resulted from a fortuitous coincidence as the orthophosphate concentration in the water/acid extracts was increased by the hydrolysis of pyrophosphate and organic P forms while at the same time there was incomplete extraction of orthophosphate. Confirmation of this was the absence of pyrophosphate in both water and acid fractions (it was detected in the whole plant material) and the finding that speciation of organic P in the fractions differed from that in the whole plant material. Evidence for incomplete extraction of orthophosphate was the finding that most of the residual P in the crop residues following water/acid extractions was detected as orthophosphate using (31)P NMR. Two methods for isolating and quantifying phospholipid P were also tested, based on solubility in ethanol:ether and ethanol:ether:chloroform. While these methods were selective and appeared to extract only phospholipid P, they did not extract all phospholipid P, as some was

  1. Evaluation of Phosphorus Characterization in Broiler Ileal Digesta, Manure, and Litter Samples: 31P-NMR vs. HPLC

    USDA-ARS?s Scientific Manuscript database

    Using 31-Phosphorus Nuclear Magnetic Resosonance Spectroscopy (31P-NMR) to characterize phosphorus (P) in manures and litter has become prevalent in the area of nutrient management. To date, there has been no published work evaluating P quantification in manure/litter samples with 31P-NMR compared t...

  2. Measurement of the {sup 77}Se, {sup 99}Ru, {sup 101}Ru and {sup 123}Te(n,{alpha}) Cross Sections with Thermal Neutrons

    SciTech Connect

    Wagemans, Cyriel; Wagemans, Jan; Geltenbort, Peter

    2009-01-28

    Results of (n,{alpha}) cross section measurements performed at the high flux reactor of the Institute Laue-Langevin in Grenoble (France) are reported. Cross section values are given for the {alpha}{sub 0}, {alpha}{sub 1} and {alpha}{sub 2} transitions in {sup 77}Se(n,{alpha}){sup 74}Ge, the {alpha}{sub 0} and {alpha}{sub 1} transitions in {sup 99}Ru(n,{alpha}){sup 96}Mo, the {alpha}{sub 0} and {alpha}{sub 1} transitions in {sup 101}Ru(n,{alpha}){sup 98}Mo and the {alpha}{sub 0}, {alpha}{sub 1} and {gamma}{alpha} transitions in {sup 123}Te(n,{alpha}){sup 120}Sn. Corresponding resonance data reported in the literature are confronted with these results.

  3. 31P nuclear magnetic resonance spectroscopy: noninvasive biochemical analysis of the ischemic extremity.

    PubMed

    Zatina, M A; Berkowitz, H D; Gross, G M; Maris, J M; Chance, B

    1986-03-01

    The biochemical effects of peripheral vascular disease on skeletal muscle have not been characterized precisely because of the lack of satisfactory noninvasive analytic methods. 31P nuclear magnetic resonance (NMR) spectroscopy was used to measure the high-energy phosphate compounds, phosphocreatine (PCr) and adenosine triphosphate, as well as metabolic byproducts, such as inorganic phosphates (Pi) and phosphate monoesters in calf muscles of 214 limbs with peripheral vascular disease. Intracellular pH was also measured. The NMR index (Pi[PCr + Pi]) was used to quantitate the impairment of oxidative phosphorylation as a result of ischemia. Studies done at rest documented the impairment of oxidative metabolism only in limbs with severe ischemia (ankle-brachial pressure index (API) less than 0.4). Exercise resulted in a significant elevation of the NMR index in all limbs and the rate of return of this value toward normal following exercise was prolonged even in limbs with moderate ischemia (0.4 less than or equal to API less than or equal to 0.9). Correlation of 31P NMR parameters with arteriograms showed that infrapopliteal occlusions resulted in prolonged recovery times only when the superficial femoral artery was occluded and emphasized the metabolic consequences of multisegmental disease. Accumulation of glycolytic pathway intermediates correlated with the decrease in muscle cell pH observed with exercise. Despite immediate improvement in symptoms and hemodynamic parameters following revascularization, return to normal biochemical function occurs over a prolonged period of time. This study demonstrates that 31P NMR spectroscopy can successfully measure noninvasively the important phosphorus-containing compounds involved in the bioenergetics of skeletal muscle in vivo rapidly enough to permit real-time determination during exercise and recovery.

  4. Membrane interactions in small fast-tumbling bicelles as studied by 31P NMR.

    PubMed

    Bodor, Andrea; Kövér, Katalin E; Mäler, Lena

    2015-03-01

    Small fast-tumbling bicelles are ideal for studies of membrane interactions at molecular level; they allow analysis of lipid properties using solution-state NMR. In the present study we used 31P NMR relaxation to obtain detailed information on lipid head-group dynamics. We explored the effect of two topologically different membrane-interacting peptides on bicelles containing either dimyristoylphosphocholine (DMPC), or a mixture of DMPC and dimyristoylphosphoglycerol (DMPG), and dihexanoylphosphocholine (DHPC). KALP21 is a model transmembrane peptide, designed to span a DMPC bilayer and dynorphin B is a membrane surface active neuropeptide. KALP21 causes significant increase in bicelle size, as evidenced by both dynamic light scattering and 31P T2 relaxation measurements. The effect of dynorphin B on bicelle size is more modest, although significant effects on T2 relaxation are observed at higher temperatures. A comparison of 31P T1 values for the lipids with and without the peptides showed that dynorphin B has a greater effect on lipid head-group dynamics than KALP21, especially at elevated temperatures. From the field-dependence of T1 relaxation data, a correlation time describing the overall lipid motion was derived. Results indicate that the positively charged dynorphin B decreases the mobility of the lipid molecules--in particular for the negatively charged DMPG--while KALP21 has a more modest influence. Our results demonstrate that while a transmembrane peptide has severe effects on overall bilayer properties, the surface bound peptide has a more dramatic effect in reducing lipid head-group mobility. These observations may be of general importance for understanding peptide-membrane interactions. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Evaporation residue excitation function and spin distribution for 31P + 170Er

    NASA Astrophysics Data System (ADS)

    Mohanto, G.; Madhavan, N.; Nath, S.; Gehlot, J.; Mukul, Ish; Jhingan, A.; Varughese, T.; Roy, A.; Bhowmik, R. K.; Mazumdar, I.; Gothe, D. A.; Chavan, P. B.; Sadhukhan, J.; Pal, S.; Kaur, Maninder; Singh, Varinderjit; Sinha, A. K.; Ramamurthy, V. S.

    2013-09-01

    Background: Synthesis of a doubly magic spherical nucleus beyond 82208Pb126 is a key question in contemporary nuclear physics. Such nuclei can exist solely because of shell stabilization. As the formation cross section of super heavy elements is prohibitively low, attempts have been made to understand stabilizing effects of closed proton (Z) and neutron (N) shells in the vicinity of 82208Pb126.Purpose: The present work attempts to elucidate the stabilizing effect of shell closure, in general, and the same of Z=82, in particular.Methods: The evaporation residue (ER) excitation function and ER-gated γ-multiplicity distribution have been measured for the reaction 31P + 170Er at a laboratory energy range of 134-172 MeV. The measurements have been carried out using the HYbrid Recoil mass Analyzer (HYRA) in gas-filled mode and a 4π spin spectrometer consisting of 29 NaI(Tl) detectors. Results of the present reaction have been compared with those of the reaction 30Si + 170Er. Statistical model calculation has been performed for both the systems.Results: The two reactions, induced by 30Si and 31P projectiles, resulted in compound nuclei (CN) 200Pb (Z=82) and 201Bi (Z=83), respectively. To reproduce experimental ER cross sections, the liquid drop fission barrier (Bf) had to be scaled in the statistical model calculation. The scaling factor (Kf) varies from 0.75 to 1.05 and 0.90 to 1.05 for 30Si and 31P induced reactions, respectively. No significant differences have been found between γ-multiplicity distribution and the distribution moments of the two systems.Conclusions: No clear signature has been observed in favor of extra stability of the ERs with closed proton shell (Z=82) as Kf values of the two systems match within errors. More exclusive measurements and comparison between more systems forming CN/ER around Z=82 are desirable.

  6. Quantitative monitoring of extracellular matrix production in bone implants by 13C and 31P solid-state nuclear magnetic resonance spectroscopy.

    PubMed

    Schulz, J; Pretzsch, M; Khalaf, I; Deiwick, A; Scheidt, H A; Salis-Soglio, G; Bader, A; Huster, D

    2007-04-01

    We used (31)P and (13)C solid-state nuclear magnetic resonance (NMR) spectroscopy to detect and analyze the major organic and inorganic components (collagen type I and bioapatite) in natural rabbit bone and beta-tricalcium phosphate implants loaded with osteogenically differentiated mesenchymal stem cells. High-resolution solid-state NMR spectra were obtained using the magic-angle spinning (MAS) technique. The (31)P NMR spectra of bone specimens showed a single line characteristic of bone calcium phosphate. (13)C cross-polarization (CP) MAS NMR spectra of bone exhibited the characteristic signatures of collagen type I with good resolution for all major amino acids in collagen. Quantitative measurements of (13)C-(1)H dipolar couplings indicated that the collagen segments are very rigid, undergoing only small amplitude fluctuations with correlation times in the nanosecond range. In contrast, directly polarized (13)C MAS NMR spectra of rabbit bone were dominated by signals of highly mobile triglycerides. These quantitative investigations of natural bone may provide the basis for a quality control of various osteoinductive bone substitutes. We studied the formation of extracellular bone matrix in artificial mesenchymal stem cell-loaded beta-tricalcium phosphate matrices that were implanted into the femoral condyle of rabbits. The NMR spectra of these bone grafts were acquired 3 months after implantation. In the (31)P NMR spectra, beta-tricalcium phosphate and bone calcium phosphate could be distinguished quantitatively, allowing recording of the formation of the natural bone matrix. Further, (13)C CPMAS allowed detection of collagen type I that had been produced in the implants. Comparison with the spectroscopic data from natural bone allowed assessment of the quality of the bone substitute material.

  7. sup 31 P NMR analysis of coal moieties bearing -OH, -NH and -SH functions

    SciTech Connect

    Verkade, J.G.

    1990-01-01

    Research continues on the structural analysis of coal. In attempting to derivatize solid coal for solid state NMR analysis, we observed {sup 31}P NMR shifts in an unexpected region; these interesting leads will be pursued on the chance that the reaction we have evoked holds potential for yielding new coal characterizational information. Two very gratifying results have emerged from our {sup 119}Sn chemical shift measurements of a limited set of model compounds in pyridine. Firstly, the chemical shift dispersion is very large for phenols, alcohols and amides. Secondly, unlike {sup 119}Sn chemical shifts in hexane or chloroform, the shifts in pyridine are concentration independent.

  8. How Bonding in Manganous Phosphates Affects their Mn(II)-(31)P Hyperfine Interactions.

    PubMed

    Un, Sun; Bruch, Eduardo M

    2015-11-02

    Manganous phosphates have been postulated to play an important role in cells as antioxidants. In situ Mn(II) electron-nuclear double resonance (ENDOR) spectroscopy has been used to measure their speciation in cells. The analyses of such ENDOR spectra and the quantification of cellular Mn(II) phosphates has been based on comparisons to in vitro model complexes and heuristic modeling. In order to put such analyses on a more physical and theoretical footing, the Mn(II)-(31)P hyperfine interactions of various Mn(II) phosphate complexes have been measured by 95 GHz ENDOR spectroscopy. The dipolar components of these interactions remained relatively constant as a function of pH, esterification, and phosphate chain length, while the isotropic contributions were significantly affected. Counterintuitively, although the manganese-phosphate bonds are weakened by protonation and esterification, they lead to larger isotropic values, indicating higher unpaired-electron spin densities at the phosphorus nuclei. By comparison, extending the phosphate chain with additional phosphate groups lowers the spin density. Density functional theory calculations of model complexes quantitatively reproduced the measured hyperfine couplings and provided detailed insights into how bonding in Mn(II) phosphate complexes modulates the electron-spin polarization and consequently their isotropic hyperfine couplings. These results show that various classes of phosphates can be identified by their ENDOR spectra and provide a theoretical framework for understanding the in situ (31)P ENDOR spectra of cellular Mn(II) complexes.

  9. Evaluation of cerebral 31-P chemical shift images utilizing statistical parametric mapping

    NASA Astrophysics Data System (ADS)

    Riehemann, Stefan; Gaser, Christian; Volz, Hans-Peter; Sauer, Heinrich

    1999-05-01

    We present an evaluation technique of two dimensional (2D) nuclear magnetic resonance (NMR) chemical shift images (CSI) to analyze spatial differences of metabolite distributions and/or concentrations between groups of probands. Thus, chemical shift imaging is not only used as localization technique for NMR-spectroscopy, but the information of the complete spectroscopic image is used for the evaluation process. 31P CSI of the human brain were acquired with a Philips Gyroscan ACSII whole-body scanner at 1.5 T. CSI for different phosphorus metabolites were generated, all representing the same anatomical location. For each metabolite the CSI of two groups of subjects were compared with each other using the general linear model implemented in the widely distributed SPM96 software package. With this approach, even covariates or confounding variables like age or medication can be considered. As an example for the application of this technique, variations in the distribution of the 31P metabolite phosphocreatin between unmedicated schizophrenic patients and healthy controls were visualized. To our knowledge, this is the first approach to analyze spatial variations in metabolite concentrations between groups of subjects on the basis of chemical shift images. The presented technique opens a new perspective in the evaluation of 2D NMR spectroscopic data.

  10. In vivo sup 31 P-NMR spectroscopy of chronically stimulated canine skeletal muscle

    SciTech Connect

    Clark, B.J. III; McCully, A.K.; Subramanian, H.V.; Hammond, R.L.; Salmons, S.; Chance, B.; Stephenson, L.W. Univ. of Pennsylvania School of Medicine, Philadelphia Univ. of Birmingham )

    1988-02-01

    Chronic stimulation converts skeletal muscle of mixed fiber type to a uniform muscle made up of type I, fatigue-resistant fibers. Here, the bioenergetic correlates of fatigue resistance in conditioned canine latissimus dorsi are assessed with in vivo phosphorus-31 nuclear magnetic resonance ({sup 31}P-NMR) spectroscopy. After chronic electrical stimulation, five dogs underwent {sup 31}P-NMR spectroscopic and isometric tension measurements on conditioned and contralateral control muscle during stimulation for 200, 300, 500, and 800 ms of an 1,100-ms duty cycle. With stimulation, phosphocreatine (PCr) fell proportional to the degree of stimulation in both conditioned and control muscle but fell significantly less in conditioned muscle at all the least intense stimulation period (200 ms). Isometric tension, expressed as a tension time index per gram muscle, was significantly greater in the conditioned muscle at the two longest stimulation periods. The overall small change in PCr and the lack of a plateau in tension observed in the conditioned muscle are similar to that seen in cardiac muscle during increased energy demand. This study indicates that the conditioned muscle's markedly enhanced resistance to fatigue is in part the result of its increased capacity for oxidative phosphorylation.

  11. 13C and 31P NMR for the diagnosis of muscular phosphorylase-kinase deficiency

    NASA Astrophysics Data System (ADS)

    Jehenson, P.; Duboc, D.; Laforet, P.; Eymard, B.; Lombès, A.; Fardeau, M.; Brunet, P.; Syrota, A.

    1998-02-01

    To further develop and specify the range of medical applications of in vivo NMR spectroscopy for the study of myopathies, it is ncessary to study the largest number of well characterized cases. We here report on the 31P and 13C NMR study of a purely muscular form of phosphorylase-kinase (PK) deficiency. Abnormalities were observed that agree with and increase our pathophysiological knowledge, in particular on the activation of phosphorylase and PK. Also, the abnormalities are different from those found in other clinically similar metabolic myopathies and could be used for the differential diagnosis. Afin de continuer à développer et préciser les applications médicales de la spectroscopie RMN in vivo, il faut étudier le plus grand nombre possible de cas bien caractérisés. Nous avons étudié ici une forme purement musculaire de déficit en phosphorylase-kinase (PK) par RMN du phosphore 31 et du carbone 13. Les altérations observées sont en accord avec et augmentent nos connaissances physiopathologiques, par exemple concernant l'activation de la phosphorylase et PK. Par ailleurs, la combinaison d'altérations observées en 31P et 13C est différente de celle retrouvée dans d'autres myopathies métaboliques cliniquement semblables et pourrait être utilisée pour le diagnostic différentiel.

  12. 31P NMR conformational studies of non-palindromic DNA duplexes related to HIV-1 enhancer

    NASA Astrophysics Data System (ADS)

    Tisne, C.; Simenel, C.; Hantz, E.; Delepierre, M.

    1998-02-01

    Assignment of all 31P resonances of 16 base-pair DNA duplexes, 5' d(CTGGGGACTTTCCAGG)3' 5' d(CCTGGAAAGTCCCCAG)3', related to the DNA kappaB site of the HIV-1 LTR together with a mutated sequence 5' d(CTGCTCACTTTCCAGG)3' 5' d(CCTGGAAAGTGAGCAG)3' was determined by 2D heteronuclear inverse NMR spectroscopy (HSQC-TOCSY and heteronuclear COSY). ^3JH{3'}-P coupling constants for most of the phosphates of the mutated oligomer were obtained using heteronuclear selective COSY. L'attribution des résonances 31P du fragment d'ADN de seize paires de base 5' d(CTGGGGACTTTCCAGG)3' 5' d(CCTGGAAAGTCCCCAG)3' (16N) correspondant au site kappaB du LTR du HIV-1 et de la séquence mutée 5' d(CTGCTCACTTTCCAGG)3' 5' d(CCTGGAAAGTGAGCAG)3' (16M) a été déterminée à l'aide de méthodes 2D hétéronucléaires à détection indirecte (HSQC-TOCSY et COSY hétéronucléaires). Les constantes de couplage ^3JH{3'}-P ont été mesurées pour la plupart des phosphates de 16 M à l'aide d'expérience COSY hétéronucléaires sélectives.

  13. 2D exchange 31P NMR spectroscopy of bacteriophage M13 and tobacco mosaic virus.

    PubMed Central

    Magusin, P C; Hemminga, M A

    1995-01-01

    Two-dimensional (2D) exchange 31P nuclear magnetic resonance spectroscopy is used to study the slow overall motion of the rod-shaped viruses M13 and tobacco mosaic virus in concentrated gels. Even for short mixing times, observed diagonal spectra differ remarkably from projection spectra and one-dimensional spectra. Our model readily explains this to be a consequence of the T2e anisotropy caused by slow overall rotation of the viruses about their length axis. 2D exchange spectra recorded for 30% (w/w) tobacco mosaic virus with mixing times < 1 s do not show any off-diagonal broadening, indicating that its overall motion occurs in the sub-Hz frequency range. In contrast, the exchange spectra obtained for 30% M13 show significant off-diagonal intensity for mixing times of 0.01 s and higher. A log-gaussian distribution around 25 Hz of overall diffusion coefficients mainly spread between 1 and 10(3) Hz faithfully reproduces the 2D exchange spectra of 30% M13 recorded at various mixing times in a consistent way. A small but notable change in diagonal spectra at increasing mixing time is not well accounted for by our model and is probably caused by 31P spin diffusion. PMID:7756532

  14. Quantitative 31P nuclear magnetic resonance analysis of metabolite concentrations in Langendorff-perfused rabbit hearts.

    PubMed Central

    Gard, J K; Kichura, G M; Ackerman, J J; Eisenberg, J D; Billadello, J J; Sobel, B E; Gross, R W

    1985-01-01

    The quantitative analysis of the mobile high-energy phosphorus metabolites in isovolumic Langendorff-perfused rabbit hearts has been performed by 31P NMR utilizing rapid pulse repetition to optimize sensitivity. Absolute quantification required reference to an external standard, determination of differential magnetization saturation and resonance peak area integration by Lorentzian lineshape analysis. Traditionally accepted hemodynamic indices (LVDP, dp/dt) and biochemical indices (lactate, pyruvate) of myocardial function were measured concomitantly with all NMR determinations. Hemodynamically and biochemically competent Langendorff-perfused rabbit hearts were found to have intracellular PCr, ATP, GPC, and Pi concentrations of 14.95 +/- 0.25, 8.08 +/- 0.13, 5.20 +/- 0.58 and 2.61 +/- 0.47 mM respectively. Intracellular pH was 7.03 +/- 0.01. Cytosolic ADP concentration was derived from a creatine kinase equilibrium model and determined to be approximately 36 microM. Reduction of perfusate flow from 20 to 2.5 ml/min demonstrated statistically significant decreases in PCr, ATP, and pH as well as an increase in Pi that correlated closely with the independent hemodynamic and biochemical indices of myocardial function. The decrease in ATP and PCr concentrations precisely matched the increase in Pi during reduced flow. These results constitute the first quantitative determination of intracellular metabolite concentrations by 31P NMR in intact rabbit myocardium under physiologic and low flow conditions. PMID:4074839

  15. Internuclear 31P-51V Distance Measurements in Polyoxoanionic Solids Using REAPDOR NMR Spectroscopy

    PubMed Central

    Huang, Wenlin; Vega, Alexander J.; Gullion, Terry; Polenova, Tatyana

    2014-01-01

    We report the first results establishing REAPDOR experiments for distance measurements between a spin-1/2 (31P) and spin-7/2 (51V) pair in a series of vanadium-substituted polyoxoanionic solids from the Keggin and Wells-Dawson families. We have quantitatively measured 31P-51V distances in mono-vanadium substituted K4PVW11O40, 1-K7P2VW17O62, and 4-K7P2VW17O62. Numerical simulations of the experimental data yield very good agreement with the averaged P-W/P-V distances determined from the X-ray diffraction measurements in the same or related compounds. REAPDOR is therefore a very sensitive P-V distance probe anticipated to be especially useful in the absence of long-range order. Our results suggest that REAPDOR spectroscopy could be broadly applicable for interatomic distance measurements in other spin-7/2-spin-1/2 nuclear pairs. PMID:17918932

  16. Gated in vivo examination of cardiac metabolites with /sup 31/P nuclear magnetic resonance

    SciTech Connect

    Kantor, H.L.; Briggs, R.W.; Metz, K.R.; Balaban, R.S.

    1986-07-01

    Phosphorus-31 nuclear magnetic resonance (/sup 31/P NMR) spectroscopy was used to study the temporal aspects of metabolism of canine heart in vivo. An NMR catheter coil was passed through the jugular vein of a dog into the apex of the right ventricle and spectra were recorded at four points in the cardiac cycle by triggering from the blood pressure trace of the animal. The /sup 31/P spin-lattice relaxation times of phosphocreatine (PC) and the ..gamma../sup -/,..cap alpha../sup -/, and ..beta..-phosphates of ATP at 1.89 Tesla are 4.4, 1.8, 1.7, and 1.6 s, respectively. The ratio of PC to ATP is 2.0. No changes in PC/ATP were noted in any of the four portions of the cardiac cycle examined, and difference spectra exhibited no observable signals, in contrast to previously reported results for glucose-perfused rat hearts. On the assumption that intracellular pH and the total creatine pool were constant, the expression for the creatine kinase reaction was used to deduce that free ADP concentrations were invariant throughout the cardiac cycle. This is in apparent disagreement with the proposed regulatory role for ADP in heart oxidative phosphorylation.

  17. 31P-NMR study of resting in vitro rat diaphragm exposed to hypercapnia.

    PubMed

    Fitzgerald, R S; Howell, S; Jacobus, W E

    1988-11-01

    We have reported previously that, when exposed to hypercapnia of various intensities, the diaphragm reduces its force of twitch and tetanic contractions in the in vitro rat preparation as well as in the in vivo dog preparation. The experiments reported here with 31P nuclear magnetic resonance (31P-NMR) spectroscopy attempt to examine cellular mechanisms that might be responsible for this deterioration in mechanical performance. Specifically they describe certain characteristics of this preparation and cautions needed to study the resting in vitro rat diaphragm with such techniques. Second, they report the response of intracellular pH (pHi), phosphocreatine (PCr), ATP, and inorganic phosphate (Pi) in the resting in vitro rat diaphragm exposed to long-term normocapnia or to long-term hypercapnia. The results show that 1) to maintain a viable preparation, it was necessary to keep the diaphragm extended to an area approximating that at functional residual capacity, 2) the diaphragm seemed quite capable of maintaining a constant pHi and constant contents of ATP and Pi during normocapnia, but there was a gradual decline in PCr, and 3) during hypercapnia there was a significant decrease in pHi, but the behavior of the phosphate metabolites was exactly as during normocapnia. The results suggest that the decrease in mechanical performance of the diaphragm is probably not due to a decrease in the availability of the high-energy phosphates, although they do not completely exclude this possibility or possibilities related to regional compartmentation.

  18. Dynamics of phosphorus in suspended particles in a shallow eutrophic lake: a 31P NMR study

    NASA Astrophysics Data System (ADS)

    Shinohara, R.; Imai, A.; Kohzu, A.; Tomioka, N.; Furusato, E.; Satou, T.; Sano, T.; Komatsu, K.; Miura, S.; Shimotori, K.

    2016-12-01

    Particulate P (PP) concentration in shallow lakes is often controlled by two kinds of processes: physical (e.g., sediment resuspension) and biological (e.g., phytoplankton production). We analyzed in shallow, eutrophic Lake Kasumigaura about whether the concentration of PP is controlled by biogenic P or resuspension of inorganic P in sediment. Increases in wind velocity and turbidity were observed when bottom shear stress exceeds the critical value for the lake. However, concentrations of PP, particulate inorgnaic P in PP (PIP), and particulate organic P in PP (POP) were not correlated with wind velocity. The POP concentration accounted for approximately 79% of the PP concentration, and the concentrations of PP, PIP, and POP were correlated with that of particulate organic carbon (POC). 31P nuclear magnetic resonance (NMR) spectroscopy analysis clarified that mononucleotides accounted for the largest proportion among the detected P compound classes. Concentrations of mononucleotides, orthophosphate, and pyrophosphate were significantly higher in the samples with high POC concentrations, whereas the DNA-P concentration was not. The correlations suggest that biogenic P affects PP concentrations more strongly than does sediment resuspension. Furthermore, the 31P NMR analysis suggests that the production of biogenic P creates a pool of easily degradable P in shallow, eutrophic Lake Kasumigaura.

  19. 31P-Magnetization Transfer Magnetic Resonance Spectroscopy Measurements of In Vivo Metabolism

    PubMed Central

    Befroy, Douglas E.; Rothman, Douglas L.; Petersen, Kitt Falk; Shulman, Gerald I.

    2012-01-01

    Magnetic resonance spectroscopy offers a broad range of noninvasive analytical methods for investigating metabolism in vivo. Of these, the magnetization-transfer (MT) techniques permit the estimation of the unidirectional fluxes associated with metabolic exchange reactions. Phosphorus (31P) MT measurements can be used to examine the bioenergetic reactions of the creatine-kinase system and the ATP synthesis/hydrolysis cycle. Observations from our group and others suggest that the inorganic phosphate (Pi) → ATP flux in skeletal muscle may be modulated by certain conditions, including aging, insulin resistance, and diabetes, and may reflect inherent alterations in mitochondrial metabolism. However, such effects on the Pi → ATP flux are not universally observed under conditions in which mitochondrial function, assessed by other techniques, is impaired, and recent articles have raised concerns about the absolute magnitude of the measured reaction rates. As the application of 31P-MT techniques becomes more widespread, this article reviews the methodology and outlines our experience with its implementation in a variety of models in vivo. Also discussed are potential limitations of the technique, complementary methods for assessing oxidative metabolism, and whether the Pi → ATP flux is a viable biomarker of metabolic function in vivo. PMID:23093656

  20. Synthesis of prostanoids; enantiomeric purity of alcohols by a /sup 31/P NMR technique

    SciTech Connect

    Penning, T.D.

    1985-01-01

    The enone, 2,2-diemthyl-3a..beta.., 6a..beta..-dihydro-4H-cyclopenta-1,3-dioxol-4-one, has been synthesized in six steps from cyclopentadiene, resolved using sulfoximine chemistry, and converted into (-)-prostaglandin E/sub 2/ methyl ester in three steps. Introduction of the optically pure omega side-chain using a conjugate addition of a stabilized organocopper reagent, followed by direct alkylation of the enolate with the ..cap alpha.. side-chain allylic iodide in the presence of hexamethylphosphoramide, afforded a trans, vicinally disubstituted cyclopentanone. Deprotection of the C-15 alcohol, followed by aluminum amalgam reduction of the C-10/oxygen bond, provided (-)-PGE/sub 2/ methyl ester in 47% overall yield from the enone. In an extension of previously described work, 2-chloro-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine 2-sulfide, prepared from l-ephedrine and thiophosphoryl chloride, was used to determine the enantiomeric excess of chiral alcohols in conjunction with /sup 31/P NMR. Chiral primary and secondary alcohols added quantitatively to the phospholidine to give diastereomers which could be analyzed by /sup 31/P NMR and HPLC. A number of other phosphorus heterocycles were also explored as potential chiral derivatizing reagents.

  1. Phospholipid composition of plasma and erythrocyte membranes in animal species by 31P NMR.

    PubMed

    Ferlazzo, Alida Maria; Bruschetta, Giuseppe; Di Pietro, Patrizia; Medica, Pietro; Notti, Anna; Rotondo, Enrico

    2011-12-01

    The aim of this study was to provide basal values of phospholipid (PL) composition in different animal species by 31P NMR analysis using detergents. This fast and accurate method allowed a quantitative analysis of PLs without any previous separation. Plasma and erythrocyte membrane PLs were investigated in mammals (pig, cow, horse). Moreover, for the first time, the composition of plasma PLs in avian (chicken and ostrich) was performed by 31P NMR. Significant qualitative and quantitative interspecies differences in plasma PL levels were found. Phosphatidilcholine (PC) and sphingomyelin (SPH) levels were significantly higher (P < 0.001) in chicken plasma than all the other species tested. In erythrocytes, cow PC and phosphatidylcholine diarachidoyl were significantly lower (P < 0.001) than for pigs and horses, whereas pig PC presented intermediate values among cows and horses. Inorganic phosphate and 2,3-diphosphoglycerate levels were also significantly different between the species under investigation. The [SPH/total PLs] molar ratios in erythrocytes confirmed interspecies differences in phospholipid composition while the PC/SPH molar ratios could be related to a distinct erythrocyte flexibility and aggregability. Diet and nutrition may contribute primarily to the interspecies differences in plasma PL amounts detected. Significant differences between chicken plasma PC and SPH levels and those of the other animal species could be ascribed to a fat metabolism specific to egg production.

  2. Compartmentation of Nucleotides in Corn Root Tips Studied by 31P-NMR and HPLC 1

    PubMed Central

    Hooks, Mark A.; Clark, Robert A.; Nieman, Richard H.; Roberts, Justin K. M.

    1989-01-01

    Corn (Zea mays L.) root tips were subjected to different conditions so that nucleotide levels varied over a wide range. Levels of nucleotides in corn root tips were measured using 31P nuclear magnetic resonance (NMR) spectroscopy and high performance liquid chromatography. Results indicate: (a) Similar amounts of NTP and sugar nucleotides were observed by in vivo NMR and in extracts. In contrast, a significant amount of NDP observed in root tip extracts was not detected by in vivo NMR. Thus, for a given sample, [NTP]/[NDP] ratios determined in vivo by 31P-NMR are always higher than ratios observed in extracts, deviating by ∼4-fold at the highest ratios. The NMR-invisible pool of NDP appeared quite metabolically inert, barely changing in size as total cell NDP changed. We conclude that NDP in corn root tips is compartmented with respect to NMR visibility, and that it is the NMR-visible pool which responds dynamically to metabolic state. The NMR-invisible NDP could either be immobilized (and so have broad, undetectable NMR signals), or be complexed with species that cause the chemical shift of NDP to change (so it does not contribute to the NMR signal of free NDP), or both. (b) 31P-NMR cannot distinguish between bases (A, U, C, and G) of nucleotides. HPLC analysis of root tip extracts showed that the relative amount of each base in the NTP and NDP pools was quite constant in the different samples. (c) In extracts, for each of the nonadenylate nucleotides, [NTP]/[NDP] was linearly proportional to [ATP]/[ADP], indicating near equilibrium in the nucleoside diphosphokinase (NDPK) reaction. However, the apparent equilibrium constants for the phosphorylation of GDP and UDP by ATP were significantly lower than 1, the true equilibrium constant for the NDPK reaction. Thus, for a given sample, [ATP]/[ADP] ∼ [CTP]/[CDP] > [UTP]/[UDP] > [GTP]/[GDP]. This result suggests that the different NDPs in corn root tips do not have equal access to NDPK. PMID:16666649

  3. 77Se NMR Investigation of the KxFe2−ySe2 high-Tc Superconductor (Tc = 33 K)

    SciTech Connect

    Petrovic, C.; Torchetti, D.A. Fu, M.; Christensen, D.C.; Nelson, K.J.; Imai, T.; Lei, H.C.

    2011-03-18

    We report comprehensive {sup 77}Se NMR measurements on a single crystalline sample of the recently discovered FeSe-based high-temperature superconductor K{sub x}Fe{sub 2-y}Se{sub 2} (T{sub c} = 33 K) in a broad temperature range up to 290 K. Despite deviations from the stoichiometric KFe{sub 2}Se{sub 2} composition, we observed {sup 77}Se NMR line shapes as narrow as 4.5 kHz under a magnetic field applied along the crystal c axis, and found no evidence for co-existence of magnetic order with superconductivity. On the other hand, the {sup 77}Se NMR line shape splits into two peaks with equal intensities at all temperatures when we apply the magnetic field along the ab plane. This suggests that K vacancies may have a superstructure and that the local symmetry of the Se sites is lower than the tetragonal fourfold symmetry of the average structure. This effect might be a prerequisite for stabilizing the s{sub {+-}} symmetry of superconductivity in the absence of the hole bands at the Brillouin zone center. From the increase of NMR linewidth below T{sub c} induced by the Abrikosov lattice of superconducting vortices, we estimate the in-plane penetration depth {lambda}{sub ab} {approx} 290 nm and the carrier concentration n{sub e} {approx} 1 x 10{sup +21} cm{sup -3}. Our Knight shift {sup 77}K data indicate that the uniform spin susceptibility decreases progressively with temperature, in analogy with the case of FeSe (T{sub c} {approx} 9 K) as well as other FeAs high-T{sub c} systems. The strong suppression of {sup 77}K observed immediately below T{sub c} for all crystal orientations is consistent with a singlet pairing of Cooper pairs. We do not however observe the Hebel-Slichter coherence peak of the nuclear spin-lattice relaxation rate 1/T1 immediately below T{sub c}, expected for conventional BCS s-wave superconductors. In contrast with the case of FeSe, we do not observe evidence for an enhancement of low-frequency antiferromagnetic spin fluctuations near T{sub c

  4. Estimation of the specific surface area of apatites in human mineralized tissues using 31P MAS NMR.

    PubMed

    Kolmas, Joanna; Slósarczyk, Anna; Wojtowicz, Andrzej; Kolodziejski, Waclaw

    2007-10-01

    Specific surface areas of apatites in whole human mineralized tissues were estimated from (31)P MAS NMR linewidths: 77 m(2)g(-1) for enamel and 94 m(2)g(-1) for dentin, dental cementum and cortical bone.

  5. 31P NMR first spectral moment study of the partial magnetic orientation of phospholipid membranes.

    PubMed Central

    Picard, F; Paquet, M J; Levesque, J; Bélanger, A; Auger, M

    1999-01-01

    Structural data can be obtained on proteins inserted in magnetically oriented phospholipid membranes such as bicelles, which are most often made of a mixture of long and short chain phosphatidylcholine. Possible shapes for these magnetically oriented membranes have been postulated in the literature, such as discoidal structures with a thickness of one bilayer and with the short acyl chain phosphatidylcholine on the edges. In the present paper, a geometrical study of these oriented structures is done to determine the validity of this model. The method used is based on the determination of the first spectral moment of solid-state (31)P nuclear magnetic resonance spectra. From this first moment, an order parameter is defined that allows a quantitative analysis of partially oriented spectra. The validity of this method is demonstrated in the present study for oriented samples made of DMPC, DMPC:DHPC, DMPC:DHPC:gramicidin A and adriamycin:cardiolipin. PMID:10423434

  6. sup 31 P saturation transfer and phosphocreatine imaging in the monkey brain

    SciTech Connect

    Mora, B.; Narasimhan, P.T.; Ross, B.D. California Inst. of Tech., Pasadena ); Allman, J. ); Barker, P.B. )

    1991-10-01

    {sup 31}P magnetic resonance imaging with chemical-shift discrimination by selective excitation has been employed to determine the phosphocreatine (PCr) distribution in the brains of three juvenile macaque monkeys. PCr images were also obtained while saturating the resonance of the {gamma}-phosphate of ATP, which allowed the investigation of the chemical exchange between PCr and the {gamma}-phosphate of ATP catalyzed by creatine kinase. Superposition of the PCr images over the proton image of the same monkey brain revealed topological variations in the distribution of PCr and creatine kinase activity. PCr images were also obtained with and without visual stimulation. In two out of four experiments, an apparently localized decrease in PCr concentration was noted in visual cortex upon visual stimulation. This result is interpreted in terms of a possible role for the local ADP concentration in stimulating the accompanying metabolic response.

  7. Degradation of black phosphorus: a real-time 31P NMR study

    NASA Astrophysics Data System (ADS)

    Wang, Yue; Yang, Bingchao; Wan, Bensong; Xi, Xuekui; Zeng, Zhongming; Liu, Enke; Wu, Guangheng; Liu, Zhongyuan; Wang, Wenhong

    2016-09-01

    In this work, degradation behaviors and mechanisms of black phosphorus (BP) crystals in air under ambient conditions were investigated by nuclear magnetic resonance spectroscopy. It has been found that the 31P NMR line intensity for BP decreases exponentially during aging even at the very first several hours, suggesting the origin of the degradation of transport properties. In addition to phosphoric acid, new phosphorous acid was also well resolved in the final aging products. Moreover, BP has been found to be stable in water without the presence of oxygen molecules. These findings are relevant for better understanding of degradation behaviors of BP upon aging and should be helpful for overcoming a barrier that might hamper progress toward applications of BP as a 2D material.

  8. Detoxification of organophosphorus pesticides and nerve agents through RSDL: efficacy evaluation by (31)P NMR spectroscopy.

    PubMed

    Elsinghorst, Paul W; Worek, Franz; Koller, Marianne

    2015-03-04

    Intoxication by organophosphorus compounds, especially by pesticides, poses a considerable risk to the affected individual. Countermeasures involve both medical intervention by means of antidotes as well as external decontamination to reduce the risk of dermal absorption. One of the few decontamination options available is Reactive Skin Decontamination Lotion (RSDL), which was originally developed for military use. Here, we present a (31)P NMR spectroscopy based methodology to evaluate the detoxification efficacy of RSDL with respect to a series of organophosphorus pesticides and nerve agents. Kinetic analysis of the obtained NMR data provided degradation half-lives proving that RSDL is also reasonably effective against organophosphorus pesticides. Unexpected observations of different RSDL degradation patterns are presented in view of its reported oximate-catalyzed mechanism of action.

  9. High-fidelity adiabatic inversion of a {sup 31}P electron spin qubit in natural silicon

    SciTech Connect

    Laucht, Arne Kalra, Rachpon; Muhonen, Juha T.; Dehollain, Juan P.; Mohiyaddin, Fahd A.; Hudson, Fay; Dzurak, Andrew S.; Morello, Andrea; McCallum, Jeffrey C.; Jamieson, David N.

    2014-03-03

    The main limitation to the high-fidelity quantum control of spins in semiconductors is the presence of strongly fluctuating fields arising from the nuclear spin bath of the host material. We demonstrate here a substantial improvement in single-qubit inversion fidelities for an electron spin qubit bound to a {sup 31}P atom in natural silicon, by applying adiabatic sweeps instead of narrow-band pulses. We achieve an inversion fidelity of 97%, and we observe signatures in the spin resonance spectra and the spin coherence time that are consistent with the presence of an additional exchange-coupled donor. This work highlights the effectiveness of simple adiabatic inversion techniques for spin control in fluctuating environments.

  10. Decomposition of adsorbed VX on activated carbons studied by {sup 31}P MAS NMR

    SciTech Connect

    Ishay Columbus; Daniel Waysbort; Liora Shmueli; Ido Nir; Doron Kaplan

    2006-06-15

    The fate of the persistent OP nerve agent O-ethyl S-(2-(diisopropylamino)ethyl) methylphosphonothioate (VX) on granular activated carbons that are used for gas filtration was studied by means of 31P magic angle spinning (MAS) NMR spectroscopy. Four types of activated carbon were used, including coal-based BPL. VX as vapor or liquid was adsorbed on carbon granules, and MAS NMR spectra were recorded periodically. The results show that at least 90% of the adsorbed VX decomposes within 20 days or less to the nontoxic ethyl methylphosphonic acid (EMPA) and bis(S-2-diisopropylaminoethane) ((DES){sub 2}). Decomposition occurred irrespective of the phase from which VX was loaded, the presence of metal impregnation on the carbon surface, and the water content of the carbon. Theoretical and practical aspects of the degradation are discussed. 17 refs., 6 figs., 3 tabs.

  11. Decomposition of adsorbed VX on activated carbons studied by 31P MAS NMR.

    PubMed

    Columbus, Ishay; Waysbort, Daniel; Shmueli, Liora; Nir, Ido; Kaplan, Doron

    2006-06-15

    The fate of the persistent OP nerve agent O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX) on granular activated carbons that are used for gas filtration was studied by means of 31P magic angle spinning (MAS) NMR spectroscopy. VX as vapor or liquid was adsorbed on carbon granules, and MAS NMR spectra were recorded periodically. The results show that at least 90% of the adsorbed VX decomposes within 20 days or less to the nontoxic ethyl methylphosphonic acid (EMPA) and bis(S-2-diisopropylaminoethane) {(DES)2}. Decomposition occurred irrespective of the phase from which VX was loaded, the presence of metal impregnation on the carbon surface, and the water content of the carbon. Theoretical and practical aspects of the degradation are discussed.

  12. Field dependence study of in vivo brain (31) P MRS up to 16.4 T.

    PubMed

    Lu, Ming; Chen, Wei; Zhu, Xiao-Hong

    2014-09-01

    In vivo (31) P MRS provides a unique tool for studying bioenergetics of living organs. Although its utility has been limited by the relatively low (31) P NMR sensitivity, increasing magnetic field strength (B0 ) could significantly improve the quality and reliability of the (31) P MR spectra for biomedical research. To quantitatively understand the field dependence of in vivo (31) P MRS for brain applications, (31) P NMR sensitivity of phosphocreatine (PCr) in rat brains was measured and compared at 9.4 T and 16.4 T. Additionally, the linewidths and T1 relaxation times of PCr and adenosine triphosphate (ATP) resonances obtained from human and animal brains over a wide B0 range from 4 T, 7 T, and 9.4 T to 16.4 T were examined and their field dependences were quantified. The results indicate an approximate 1.74-fold (31) P signal-to-noise ratio (SNR) gain for PCr at 16.4 T compared with 9.4 T. An approximate power 1.4 dependence of (31) P SNR on B0 was concluded. Substantial improvements in spectral resolution and significantly shortened T1 values of brain PCr and ATP were observed at high/ultrahigh fields, contributing to an additional sensitivity gain and spectral improvement. In summary, the overall findings from this study suggest that in vivo (31) P MRS should greatly benefit from high/ultrahigh fields for noninvasive assessment of altered bioenergetics and metabolic processes associated with brain function and neurological diseases. Copyright © 2014 John Wiley & Sons, Ltd.

  13. Optical hyperpolarization and inductive readout of 31P donor nuclei in natural abundance single crystal 29Si

    NASA Astrophysics Data System (ADS)

    Alexander, Thomas; Haas, Holger; Deshpande, Rahul; Gumann, Patryk; Cory, David

    2016-05-01

    We optically polarize and inductively detect 31P donor nuclei in single crystal silicon at high magnetic fields (6 . 7T). Samples include both natural abundance 29Si and an isotopically purified 28Si sample. We observe dipolar order in the 29Si nuclear spins through a spin-locking measurement. This provides a means of characterizing spin transport in the vicinity of the 31P donors.

  14. 39K, 23Na, and 31P NMR Studies of Ion Transport in Saccharomyces cerevisiae

    NASA Astrophysics Data System (ADS)

    Ogino, T.; den Hollander, J. A.; Shulman, R. G.

    1983-09-01

    The relationship between efflux and influx of K+, Na+, and intracellular pH (pHin) in yeast cells upon energizing by oxygenation was studied by using the noninvasive technique of 39K, 23Na, and 31P NMR spectroscopy. By introducing an anionic paramagnetic shift reagent, Dy3+(P3O105-)2, into the medium, NMR signals of intra- and extracellular K+ and Na+ could be resolved, enabling us to study ion transport processes by NMR. Measurements showed that 40% of the intracellular K+ and Na+ in yeast cells contributed to the NMR intensities. By applying this correction factor, the intracellular ion concentrations were determined to be 130-170 mM K+ and 2.5 mM Na+ for fresh yeast cells. With the aid of a home-built solenoidal coil probe for 39K and a double-tuned probe for 23Na and 31P, we could follow time courses of K+ and Na+ transport and of pHin with a time resolution of 1 min. It was shown that H+ extrusion is correlated with K+ uptake and not with Na+ uptake upon energizing yeast cells by oxygenation. When the cells were deenergized after the aerobic period, K+ efflux, H+ influx, and Na+ influx were calculated to be 1.6, 1.5, and 0.15 μ mol/min per ml of cell water, respectively. Therefore, under the present conditions, K+ efflux is balanced by exchange for H+ with an approximate stoichiometry of 1:1.

  15. 31P magnetization transfer measurements of Pi→ATP flux in exercising human muscle

    PubMed Central

    Savage, David B.; Williams, Guy B.; Porter, David; Carpenter, T. Adrian; Brindle, Kevin M.; Kemp, Graham J.

    2016-01-01

    Fundamental criticisms have been made over the use of 31P magnetic resonance spectroscopy (MRS) magnetization transfer estimates of inorganic phosphate (Pi)→ATP flux (VPi-ATP) in human resting skeletal muscle for assessing mitochondrial function. Although the discrepancy in the magnitude of VPi-ATP is now acknowledged, little is known about its metabolic determinants. Here we use a novel protocol to measure VPi-ATP in human exercising muscle for the first time. Steady-state VPi-ATP was measured at rest and over a range of exercise intensities and compared with suprabasal oxidative ATP synthesis rates estimated from the initial rates of postexercise phosphocreatine resynthesis (VATP). We define a surplus Pi→ATP flux as the difference between VPi-ATP and VATP. The coupled reactions catalyzed by the glycolytic enzymes GAPDH and phosphoglycerate kinase (PGK) have been shown to catalyze measurable exchange between ATP and Pi in some systems and have been suggested to be responsible for this surplus flux. Surplus VPi-ATP did not change between rest and exercise, even though the concentrations of Pi and ADP, which are substrates for GAPDH and PGK, respectively, increased as expected. However, involvement of these enzymes is suggested by correlations between absolute and surplus Pi→ATP flux, both at rest and during exercise, and the intensity of the phosphomonoester peak in the 31P NMR spectrum. This peak includes contributions from sugar phosphates in the glycolytic pathway, and changes in its intensity may indicate changes in downstream glycolytic intermediates, including 3-phosphoglycerate, which has been shown to influence the exchange between ATP and Pi catalyzed by GAPDH and PGK. PMID:26744504

  16. Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (/sup 31/P NMR)

    SciTech Connect

    Watters, T.; Wikman-Coffelt, J.; Wu, S.; Wendland, M.; James, T.; Sievers, R.; Botvinick, E.; Parmley, W.

    1986-03-05

    The authors assessed the metabolic and mechanical effects of changes in coronary perfusion pressure (CPP) and afterload (A) in isolated working apex-ejecting rat hearts perfused with Krebs-Henseleit solution containing an excess of O/sub 2/ and substrate. Log(phosphorylation potential) or log (ATP)/(ADP)x (Pi), designated (L), and log (PCR)/(Pi), designated (L*), were calculated from HPLC measurements after rapid freeze-clamping. Increasing CPP from 80-140 cm H/sub 2/O caused an increase in coronary flow(flow), developed pressure(DevP), O/sub 2/ consumption (VO/sub 2/), L, L*, and CO. L and L* were directly related to VO/sub 2/ and CO. Increasing A from 80-140 cm H/sub 2/O caused an increase in DevP and VO/sub 2/, but a decrease in L, L*, and CO. L and L* were inversely linearly related to VO/sub 2/ but were directly linearly related to CO. In both experiments, L and L* are directly related to CO, suggesting that determination of L* (which can be done with /sup 31/P NMR spectroscopy) may be a useful non-invasive method for determining cardiac pump function curves. L and L* may be related to the Frank-Starling mechanism. In a separate experiment using /sup 31/P NMR spectroscopy of isovolumic (left ventricular balloon) perfused rat hearts, increasing CPP caused a direct linear increase in flow, DevP, and L*, confirming the L* results reported above with CPP experiments using the rapid freeze-clamp technique.

  17. Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (31-P NMR)

    SciTech Connect

    Watters, T.; Wikman-Coffelt, J.; Wu, S.; Wendland, M.; James, T.; Sievers, R.; Botvinick, E.; Parmley, W.

    1986-03-05

    The authors assessed the metabolic and mechanical effects of changes in coronary perfusion pressure (CPP) and afterload (A) in isolated working apex-ejecting rat hearts perfused with Krebs-Henseleit solution containing an excess of O/sub 2/ and substrate. Log (phosphorylation potential) or log (ATP)/(ADP)x (Pi), designated (L), and log (PCR)/(Pi), designated (L*), were calculated from HPLC measurements after rapid freeze-clamping. Increasing CPP from 80-140 cm H/sub 2/O caused an increase in coronary flow (flow), developed pressure (DevP), O/sub 2/ consumption (VO/sub 2/), L, L*, and CO. L and L* were directly related to VO/sub 2/ and CO. Increasing A from 80-140 cm H/sub 2/O caused an increase in DevP and VO/sub 2/, but a decrease in L, L*, and CO. L and L* were inversely linearly related to VO/sub 2/ but were directly linearly related to CO. In both experiments, L and L* are directly related to CO, suggesting that determination of L* (which can be done with 31-P NMR spectroscopy) may be a useful non-invasive method for determining cardiac pump function curves. L and L* may be related to the Frank-Starling mechanism. In a separate experiment using 31-P NMR spectroscopy of isovolumic (left ventricular balloon) perfused rat hearts, increasing CPP caused a direct linear increase in flow, DevP, and L*, confirming the L* results reported above with CPP experiments using the rapid freeze-clamp technique.

  18. Composition of phosphorus in wetland soils determined by SMT and solution 31P-NMR analyses.

    PubMed

    Zhang, Wenqiang; Jin, Xin; Ding, Yuekui; Zhu, Xiaolei; Rong, Nan; Li, Jie; Shan, Baoqing

    2016-05-01

    In Eastern China, wetlands are common in the lower reaches of catchments or in coastal zones. Wetlands are at risk from eutrophication because of the large quantities of phosphorus (P) they receive from rivers. They are also decreasing in size. In this contribution, we present information about the composition of P in wetland soils, obtained using the Standards, Measurements, and Testing (SMT) protocol and (31)P-nuclear magnetic resonance (NMR) spectroscopy. Average P concentrations varied in the different wetland soils and, in four of the five wetlands sampled, exceeded 500 mg∙kg(-1). HCl-inorganic P (Pi) was the main Pi fraction in wetland soils. The percentage contribution of Pi (89.7 %) to total P was the highest in the Yangtze River estuary wetland. Six P components were detected by (31)P-NMR analysis. Mono-P was the main organic P (Po) in wetland soils. Orthophosphate (Ortho-P) was positively and negatively related to NaOH-Pi (R (2) = 0.957, p < 0.001) and HCl-Pi (R (2) = -0.689, p < 0.001), respectively. Orthophosphate monoesters (Mono-P) were positively related to Po (R (2) = 0.617, p < 0.001) and ortho-P (R (2) = 0.624, p < 0.001), respectively. The main Po component was Mono-P, and it may be mineralized to ortho-P under the frequently changing redox conditions in wetland soils. The information from this study will support the development of robust scientific and effective policy for P management in wetlands.

  19. Evaluation of phosphorus characterization in broiler ileal digesta, manure, and litter samples: (31)P-NMR vs. HPLC.

    PubMed

    Leytem, A B; Kwanyuen, P; Plumstead, P W; Maguire, R O; Brake, J

    2008-01-01

    Using 31-phosphorus nuclear magnetic resonance spectroscopy ((31)P-NMR) to characterize phosphorus (P) in animal manures and litter has become a popular technique in the area of nutrient management. To date, there has been no published work evaluating P quantification in manure/litter samples with (31)P-NMR compared to other accepted methods such as high performance liquid chromatography (HPLC). To evaluate the use of (31)P-NMR to quantify myo-inositol hexakisphosphate (phytate) in ileal digesta, manure, and litter from broilers, we compared results obtained from both (31)P-NMR and a more traditional HPLC method. The quantification of phytate in all samples was very consistent between the two methods, with linear regressions having slopes ranging from 0.94 to 1.07 and r(2) values of 0.84 to 0.98. We compared the concentration of total monoester P determined with (31)P-NMR with the total inositol P content determined with HPLC and found a strong linear relationship between the two measurements having slopes ranging from 0.91 to 1.08 and r(2) values of 0.73 to 0.95. This suggests that (31)P-NMR is a very reliable method for quantifying P compounds in manure/litter samples.

  20. 77Se solid-state NMR of As2Se3, As4Se4 and As4Se3 crystals: a combined experimental and computational study.

    PubMed

    Sykina, Kateryna; Yang, Guang; Roiland, Claire; Le Pollès, Laurent; Le Fur, Eric; Pickard, Chris J; Bureau, Bruno; Furet, Eric

    2013-05-07

    (77)Se NMR parameters for three prototypical crystalline compounds (As2Se3, As4Se4 and As4Se3) have been determined from solid-state NMR spectra in the framework of an investigation concerning AsxSe(1-x) glass structure understanding. Density functional NMR calculations using the gauge including projector augmented wave methodology have been performed on X-ray and optimized crystal structures for a set of selenium-based crystals. These theoretical results have been combined with the experimental data in order to achieve a precise assignment of the spectral lines. This work and the high sensitivity of solid-state NMR to local order show that the structure of As4Se3 should be reinvestigated using state-of-the-art diffraction techniques. Calculations performed on several molecules derived from the crystal structures have demonstrated the limited effect of interlayer or intermolecular interactions on the isotropic chemical shifts. These interactions are therefore not responsible for the unexpected large chemical shift difference observed between these three systems that could mostly be attributed to the presence of short rings.

  1. Phosphodiester content measured in human liver by in vivo (31) P MR spectroscopy at 7 tesla.

    PubMed

    Purvis, Lucian A B; Clarke, William T; Valkovič, Ladislav; Levick, Christina; Pavlides, Michael; Barnes, Eleanor; Cobbold, Jeremy F; Robson, Matthew D; Rodgers, Christopher T

    2017-02-28

    Phosphorus ((31) P) metabolites are emerging liver disease biomarkers. Of particular interest are phosphomonoester and phosphodiester (PDE) "peaks" that comprise multiple overlapping resonances in (31) P spectra. This study investigates the effect of improved spectral resolution at 7 Tesla (T) on quantifying hepatic metabolites in cirrhosis. Five volunteers were scanned to determine metabolite T1 s. Ten volunteers and 11 patients with liver cirrhosis were scanned at 7T. Liver spectra were acquired in 28 min using a 16-channel (31) P array and 3D chemical shift imaging. Concentrations were calculated using γ-adenosine-triphosphate (γ-ATP) = 2.65 mmol/L wet tissue. T1 means ± standard deviations: phosphatidylcholine 1.05 ± 0.28 s, nicotinamide-adenine-dinucleotide (NAD(+) ) 2.0 ± 1.0 s, uridine-diphosphoglucose (UDPG) 3.3 ± 1.4 s. Concentrations in healthy volunteers: α-ATP 2.74 ± 0.11 mmol/L wet tissue, inorganic phosphate 2.23 ± 0.20 mmol/L wet tissue, glycerophosphocholine 2.34 ± 0.46 mmol/L wet tissue, glycerophosphoethanolamine 1.50 ± 0.28 mmol/L wet tissue, phosphocholine 1.06 ± 0.16 mmol/L wet tissue, phosphoethanolamine 0.77 ± 0.14 mmol/L wet tissue, NAD(+) 2.37 ± 0.14 mmol/L wet tissue, UDPG 2.00 ± 0.22 mmol/L wet tissue, phosphatidylcholine 1.38 ± 0.31 mmol/L wet tissue. Inorganic phosphate and phosphatidylcholine concentrations were significantly lower in patients; glycerophosphoethanolamine concentrations were significantly higher (P < 0.05). We report human in vivo hepatic T1 s for phosphatidylcholine, NAD(+) , and UDPG for the first time at 7T. Our protocol allows high signal-to-noise, repeatable measurement of metabolite concentrations in human liver. The splitting of PDE into its constituent peaks at 7T may allow more insight into changes in metabolism. Magn Reson Med, 2017. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of

  2. Structural transitions in short-chain lipid assemblies studied by (31)P-NMR spectroscopy.

    PubMed

    Kleinschmidt, Jörg H; Tamm, Lukas K

    2002-08-01

    The self-assembled supramolecular structures of diacylphosphatidylcholine (diC(n)PC), diacylphosphatidylethanolamine (diC(n)PE), diacylphosphatidyglycerol (diC(n)PG), and diacylphosphatidylserine (diC(n)PS) were investigated by (31)P nuclear magnetic resonance (NMR) spectroscopy as a function of the hydrophobic acyl chain length. Short-chain homologs of these lipids formed micelles, and longer-chain homologs formed bilayers. The shortest acyl chain lengths that supported bilayer structures depended on the headgroup of the lipids. They increased in the order PE (C(6)) < PC (C(9)) < or = PS (C(9) or C(10)) < PG (C(11) or C(12)). This order correlated with the effective headgroup area, which is a function of the physical size, charge, hydration, and hydrogen-bonding capacity of the four headgroups. Electrostatic screening of the headgroup charge with NaCl reduced the effective headgroup area of PS and PG and thereby decreased the micelle-to-bilayer transition of these lipid classes to shorter chain lengths. The experimentally determined supramolecular structures were compared to the assembly states predicted by packing constraints that were calculated from the hydrocarbon-chain volume and effective headgroup area of each lipid. The model accurately predicted the chain-length threshold for bilayer formation if the relative displacement of the acyl chains of the phospholipid were taken into account. The model also predicted cylindrical rather than spherical micelles for all four diacylphospholipid classes and the (31)P-NMR spectra provided evidence for a tubular network that appeared as an intermediate phase at the micelle-to-bilayer transition. The free energy of micellization per methylene group was independent of the structure of the supramolecular assembly, but was -0.95 kJ/mol (-0.23 kcal/mol) for the PGs compared to -2.5 kJ/mol (-0.60 kcal/mol) for the PCs. The integral membrane protein OmpA did not change the bilayer structure of thin (diC(10)PC) bilayers.

  3. On Neglecting Chemical Exchange Effects When Correcting in Vivo 31P MRS Data for Partial Saturation

    NASA Astrophysics Data System (ADS)

    Ouwerkerk, Ronald; Bottomley, Paul A.

    2001-02-01

    Signal acquisition in most MRS experiments requires a correction for partial saturation that is commonly based on a single exponential model for T1 that ignores effects of chemical exchange. We evaluated the errors in 31P MRS measurements introduced by this approximation in two-, three-, and four-site chemical exchange models under a range of flip-angles and pulse sequence repetition times (TR) that provide near-optimum signal-to-noise ratio (SNR). In two-site exchange, such as the creatine-kinase reaction involving phosphocreatine (PCr) and γ-ATP in human skeletal and cardiac muscle, errors in saturation factors were determined for the progressive saturation method and the dual-angle method of measuring T1. The analysis shows that these errors are negligible for the progressive saturation method if the observed T1 is derived from a three-parameter fit of the data. When T1 is measured with the dual-angle method, errors in saturation factors are less than 5% for all conceivable values of the chemical exchange rate and flip-angles that deliver useful SNR per unit time over the range T1/5 ≤ TR ≤ 2T1. Errors are also less than 5% for three- and four-site exchange when TR ≥ T1*/2, the so-called "intrinsic" T1's of the metabolites. The effect of changing metabolite concentrations and chemical exchange rates on observed T1's and saturation corrections was also examined with a three-site chemical exchange model involving ATP, PCr, and inorganic phosphate in skeletal muscle undergoing up to 95% PCr depletion. Although the observed T1's were dependent on metabolite concentrations, errors in saturation corrections for TR = 2 s could be kept within 5% for all exchanging metabolites using a simple interpolation of two dual-angle T1 measurements performed at the start and end of the experiment. Thus, the single-exponential model appears to be reasonably accurate for correcting 31P MRS data for partial saturation in the presence of chemical exchange. Even in systems where

  4. Modified Prony Method to Resolve and Quantify in Vivo31P NMR Spectra of Tumors

    NASA Astrophysics Data System (ADS)

    Barone, P.; Guidoni, L.; Ragona, R.; Viti, V.; Furman, E.; Degani, H.

    Prony's method, successfully used in processing NMR signals, performs poorly at low signal-to-noise ratios. To overcome this problem, a statistical approach has been adopted by using Prony's method as a sampling device from the distribution associated with the true spectrum. Specifically, Prony's method is applied for each regression order p and number of data points n, both considered in a suitable range, and the estimates of frequencies, amplitudes, and decay factors are pooled separately. A histogram of the pooled frequencies is computed and, looking at the histogram, a lower and an upper frequency bound for each line of interest is determined. All frequency estimates in each of the determined intervals as well as associated decay factors and amplitudes are considered to be independent normal variates. A mean value and a corresponding 95% confidence interval are computed for each parameter. 31P NMR signals from MCF7 human breast cancer cells, inoculated into athymic mice and which developed into tumors, have been processed with traditional methods and with this modified Prony's method. The main components of the phosphomonoester peak, namely those deriving from phosphorylcholine and phosphorylethanolamine, are always well resolved with this new approach and their relative amplitudes can be consequently evaluated. Peak intensities of these two signals show different behavior during treatment of tumors with the antiestrogenic drug tamoxifen. The results of this new approach are compared with those obtainable with traditional techniques.

  5. Ongoing Dual-Angle Measurements for the Correction of Partial Saturation in 31P MR Spectroscopy

    PubMed Central

    Tyler, Damian J.; Lopez, Orlando; Cole, Mark A.; Carr, Carolyn A.; Stuckey, Daniel J.; Lakatta, Edward; Clarke, Kieran; Spencer, Richard G.

    2010-01-01

    Use of a repetition time similar to, or shorter than, metabolite T1's is common in NMR spectroscopy of biological samples to improve the signal–to–noise ratio. Conventionally, the partial saturation that results from this is corrected using saturation factors. However, this can lead to erroneous results in the presence of chemical exchange or non-constant T1's. We describe an alternative approach to correction for saturation, based on ongoing dual–angle T1 measurements (O-DAM). Using 31P MR spectroscopy of the perfused rat heart undergoing ischaemia-reperfusion, we demonstrate that signal alternations in the data acquired by the dual-angle approach are eliminated by the O-DAM correction scheme, meaning that metabolite concentration and T1 measurements can be made throughout the course of the ischaemia-reperfusion protocol. Simulations, based on parameters pertinent to the perfused rat heart, demonstrate that accurate saturation correction is possible with this method except at times of rapid concentration change. Additionally, compared to the conventional saturation factor correction method, the O-DAM correction scheme results in improved accuracy in determining the [PCr] recovery time constant. Thus, the O-DAM procedure permits accurate monitoring of metabolite concentrations even in the setting of chemical exchange and T1 changes, and allows more accurate analysis of bioenergetic status. PMID:20740663

  6. (31)P NMR phospholipid profiling of soybean emulsion recovered from aqueous extraction.

    PubMed

    Yao, Linxing; Jung, Stephanie

    2010-04-28

    The quantity and composition of phospholipids in full-fat soybean flour, flakes, and extruded flakes and in the cream fraction recovered after aqueous extraction (AEP) and enzyme-assisted aqueous extraction (EAEP) of these substrates were studied with (31)P NMR. Extruded flakes had significantly more phosphatidic acid (PA) than flakes and flour prior to aqueous extraction. The PA content of the cream recovered after AEP and EAEP of extruded flakes was similar to that of the starting material, whereas the PA content of the creams from flour and flakes significantly increased. Changes in the PA content could be explained by the action of phospholipase D during the processing step and aqueous extraction. Total phospholipids in the oil recovered from the creams varied from 0.09 to 0.75%, and free oil yield, which is an indicator of cream stability, varied from 6 to 78%. Total phospholipid did not correlate with emulsion stability when it was lower than 0.20%. Inactivation of phospholipase D prior to aqueous extraction of flour resulted in a cream emulsion less stable toward enzymatic demulsification and containing less PA and total phospholipids than untreated flour. The phospholipid distributions in the cream, skim, and insolubles obtained from AEP flour were 7, 51, and 42%, respectively.

  7. Effect of glyphosate on plant cell metabolism. 31P and 13C NMR studies.

    PubMed

    Gout, E; Bligny, R; Genix, P; Tissut, M; Douce, R

    1992-01-01

    The effect of glyphosate (N-phosphonomethyl glycine; the active ingredient of Roundup herbicide) on plant cells metabolism was analysed by 31P and 13C NMR using suspension-cultured sycamore (Acer pseudoplatanus L) cells. Cells were compressed in the NMR tube and perfused with an original arrangement enabling a tight control of the circulating nutrient medium. Addition of 1 mM glyphosate to the nutrient medium triggered the accumulation of shikimate (20-30 mumol g-1 cell wet weight within 50 h) and shikimate 3-phosphate (1-1.5 mumol g-1 cell wet weight within 50 h). From in vivo spectra it was demonstrated that these two compounds were accumulated in the cytoplasm where their concentrations reached potentially lethal levels. On the other hand, glyphosate present in the cytoplasmic compartment was extensively metabolized to yield aminomethylphosphonic acid which also accumulated in the cytoplasm. Finally, the results presented in this paper indicate that although the cell growth was stopped by glyphosate the cell respiration rates and the level of energy metabolism intermediates remained unchanged.

  8. Transport of phosphocholine in higher plant cells: 31P nuclear magnetic resonance studies.

    PubMed Central

    Gout, E; Bligny, R; Roby, C; Douce, R

    1990-01-01

    Phosphocholine (PC) is an abundant primary form of organic phosphate that is transported in plant xylem sap. Addition of PC to the perfusate of compressed Pi-starved sycamore cells monitored by 31P NMR spectroscopy resulted in an accumulation of PC and all the other phosphate esters in the cytoplasmic compartment. Addition of hemicholinium-3, an inhibitor of choline uptake, to the perfusate inhibited PC accumulation but not inorganic phosphate (Pi). When the Pi-starved cells were perfused with a medium containing either Pi or PC, the resulting Pi distribution in the cell was the same. Addition of choline instead of PC to the perfusate of compressed cells resulted in an accumulation of PC in the cytoplasmic compartment from choline kinase activity. In addition, PC phosphatase activity has been discovered associated with the cell wall. These results indicate that PC was rapidly hydrolyzed outside the cell and that choline and Pi entered the cytosolic compartment where choline kinase re-forms PC. PMID:11607080

  9. The structure of phosphate glass biomaterials from neutron diffraction and (31)P nuclear magnetic resonance data.

    PubMed

    Pickup, D M; Ahmed, I; Guerry, P; Knowles, J C; Smith, M E; Newport, R J

    2007-10-17

    Neutron diffraction and (31)P nuclear magnetic resonance spectroscopy were used to probe the structure of phosphate glass biomaterials of general composition (CaO)0.5-x(Na2O)x(P2O5)0.5 (x = 0, 0.1 and 0.5). The results suggest that all three glasses have structures based on chains of Q(2) phosphate groups. Clear structural differences are observed between the glasses containing Na2O and CaO. The P-O bonds to bridging and non-bridging oxygens are less well resolved in the neutron data from the samples containing CaO, suggesting a change in the nature of the bonding as the field strength of the cation increases [Formula: see text]. In the (CaO)0.5(P2O5)0.5 glass most of the Ca(2+) ions are present in isolated CaOx polyhedra whereas in the (Na2O)0.5(P2O5)0.5 glass the NaOx polyhedra share edges leading to a Na-Na correlation. The results of the structural study are related to the properties of the (CaO)0.4(Na2O)0.1(P2O5)0.5 biomaterial.

  10. Transport of phosphocholine in higher plant cells: sup 31 P nuclear magnetic resonance studies

    SciTech Connect

    Gout, E.; Bligny, R.; Roby, C.; Douce, R. )

    1990-06-01

    Phosphocholine (PC) is an abundant primary form of organic phosphate that is transported in plant xylem sap. Addition of PC to the perfusate of compressed P{sub i}-starved sycamore cells monitored by {sup 31}P NMR spectroscopy resulted in an accumulation of PC and all the other phosphate esters in the cytoplasmic compartment. Addition of hemicholinium-3, an inhibitor of choline uptake, to the perfusate inhibited PC accumulation but not inorganic phosphate (P{sub i}). When the P{sub i}-starved cells were perfused with a medium containing either P{sub i} or PC, the resulting P{sub i} distribution in the cell was the same. Addition of choline instead of PC to the perfusate of compressed cells resulted in an accumulation of PC in the cytoplasmic compartment from choline kinase activity. In addition, PC phosphatase activity has been discovered associated with the cell wall. These results indicate that PC was rapidly hydrolyzed outside the cell and that choline and P{sub i} entered the cytosolic compartment where choline kinase re-forms PC.

  11. β,γ-CHF- and β,γ-CHCl-dGTP diastereomers: synthesis, discrete 31P NMR signatures and absolute configurations of new stereochemical probes for DNA polymerases

    PubMed Central

    Wu, Yue; Zakharova, Valeria M.; Kashemirov, Boris A.; Goodman, Myron F.; Batra, Vinod K.; Wilson, Samuel H.; McKenna, Charles E.

    2012-01-01

    Deoxynucleoside 5′-triphosphate analogues in which the β,γ-bridging oxygen has been replaced with a CXY group are useful chemical probes to investigate DNA polymerase catalytic and base selection mechanisms. A limitation of such probes has been that conventional synthetic methods generate a mixture of diastereomers when the bridging carbon substitution is non-equivalent (X ≠ Y). We report here a general solution to this long-standing problem with four examples of individual β,γ-CXY dNTP diastereomers: (S)- and (R)-β,γ-CHCl dGTP (12a-1, 12a-2) and (S)- and (R)-β,γ-CHF dGTP (12b-1, 12b-2). Central to their preparation was conversion of the achiral parent bisphosphonic acids to P,C-dimorpholinamide derivatives (7) of their (R)-mandelic acid monoesters (6), which provided access to the individual diastereomers 7a-1, 7a-2, 7b-1, and 7b-2 by preparative HPLC. Selective acidic hydrolysis of the P-N bond then afforded the “ portal ” diastereomers 10, which were readily coupled to morpholine-activated dGMP. Removal of the chiral auxiliary by H2 (Pd/C) afforded the four individual diastereomeric nucleotides (12), which were characterized by 31P, 1H and 19F NMR, and by MS. After treatment with Chelex®-100 to remove traces of paramagnetic ions, at pH ~10 the diastereomer pairs 12a and 12b exhibit discrete Pα and Pβ 31P resonances. The more upfield Pα and more downfield Pβ resonances (and also the more upfield 19F NMR resonance in 12b) are assigned to the (R) configuration at the Pβ-CHX-Pγ carbons, based on the absolute configurations of the individual diastereomers as determined by X-ray crystallographic structures of their ternary complexes with DNA-pol β. PMID:22397499

  12. {sup 31}P NMR analysis of coal moieties bearing -OH, -NH, and -SH functions. Final technical report

    SciTech Connect

    Verkade, J.G.

    1991-08-31

    NMR reagents for the speciation and quantitation of labile-hydrogen functional groups and sulfur groups in coal ligands have been synthesized and evaluated. These reagents, which contain the NMR-active nuclei {sup 31}p, {sup 119}Sn or {sup 195}pt, were designed to possess improved chemical shift resolution over reagents reported in the literature. Our efforts were successful in the case of the new {sup 31}p and {sup 119}Sn reagents we developed, but the {sup 195}pt work on sulfur groups was only partially successful in as much as the grant came to a close and was not renewed. Our success with {sup 31}P and {sup 119}Sn NMR reagents came to the attention of Amoco and they have recently expressed interest in further supporting that work. A further measure of the success of our efforts can be seen in the nine publications supported by this grant which are cited in the reference list.

  13. Gated /sup 31/P NMR study of tetanic contraction in rat muscle depleted of phosphocreatine

    SciTech Connect

    Shoubridge, E.A.; Radda, G.K.

    1987-05-01

    Rats were fed a diet containing 1% ..beta..-guanidino-propionic acid (GPA) for 6-12 wk to deplete their muscles of phosphocreatine (PCr). Gated /sup 31/P nuclear magnetic resonance (NMR) spectra were obtained from the gastrocnemius-plantaris muscle at various time points during either a 1- or 3-s isometric tetanic contraction using a surface coil. The energy cost of a 1-s tetanus in unfatigued control rat muscle was 48.4 ..mu..mol ATP x g dry wt/sup -1/ x s/sup -1/ and was largely supplied by PCr; anaerobic glycogenolysis was negligible. In GPA-fed rats PCr was undetectable after 400 ms. This had no effect on initial force generated per gram, which was not significantly different from controls. Developed tension in a 3-s tetanus in GPA-fed rats could be divided into a peak phase (duration 0.8-0.9 s) and a plateau phase (65% peak tension) in which PCr was undetectable and the (ATP) was < 20% of that in control muscle. Energy from glycogenolysis was sufficient to maintain force generation at this submaximal level. Mean net glycogen utilization per 3-s tetanus was 78% greater than in control muscle. However, the observed decrease in intracellular pH was less than that expected from energy budget calculations, suggesting either increased buffering capacity or modulation of ATP hydrolysis in the muscles of GPA-fed rats. The results demonstrate that the transport role of PCr is not essential in contracting muscle in GPA-fed rats. PCr is probably important in this regard in the larger fibers of control muscle. Although fast-twitch muscles depleted of PCr have nearly twice the glycogen reserves of control muscle, glycogenolysis is limited in its capacity to fill the role of PCr as an energy buffer under conditions of maximum ATP turnover.

  14. 31P NMR study of erythrocytes from a patient with hereditary pyrimidine-5'-nucleotidase deficiency.

    PubMed Central

    Swanson, M S; Angle, C R; Stohs, S J; Wu, S T; Salhany, J M; Eliot, R S; Markin, R S

    1983-01-01

    The composition of phosphate metabolites and the intracellular pH in erythrocytes from a patient with hereditary pyrimidine-5'-nucleotidase deficiency were examined using 31P NMR spectroscopy. Several resonances were identified in spectra from intact cells and from extracts. The 2,3-bisphosphoglycerate line intensities were normal but the NTP resonances were about twice normal due to the presence of millimolar quantities of pyrimidine phosphates. Several intense resonances were also observed in the diphosphodiester region of the spectrum. One compound contributing to these lines has been identified as cytidine diphosphocholine. The resonances of NTPs were in a position indicating that the additional triphosphates were also bound by Mg2+. Direct measurement shows that there is a nearly proportional increase in total cell Mg2+ in the patient's cells, in agreement with the interpretation of the spectra. The intracellular pH was about 0.2 unit lower in the patient's erythrocytes. This lower pH is due to the elevation in intracellular fixed negative charges and the shift in permeable anions consequent to the Donnan equilibrium. We suggest that the lower intracellular pH may explain the lower oxygen affinity of these cells in the presence of otherwise normal 2,3-bisphosphoglycerate levels and the increased Mg2+ triphosphates level, because the Mg2+ form of NTPs is known not to alter the oxygen affinity of hemoglobin under physiologic conditions. Furthermore, the lower intracellular pH can also explain the abnormalities in glycolytic intermediates observed for these cells. PMID:6296865

  15. Interaction between beta-Purothionin and dimyristoylphosphatidylglycerol: a (31)P-NMR and infrared spectroscopic study.

    PubMed Central

    Richard, Julie-Andrée; Kelly, Isabelle; Marion, Didier; Pézolet, Michel; Auger, Michèle

    2002-01-01

    The interaction of beta-purothionin, a small basic and antimicrobial protein from the endosperm of wheat seeds, with multilamellar vesicles of dimyristoylphosphatidylglycerol (DMPG) was investigated by (31)P solid-state NMR and infrared spectroscopy. NMR was used to study the organization and dynamics of DMPG in the absence and presence of beta-purothionin. The results indicate that beta-purothionin does not induce the formation of nonlamellar phases in DMPG. Two-dimensional exchange spectroscopy shows that beta-purothionin decreases the lateral diffusion of DMPG in the fluid phase. Infrared spectroscopy was used to investigate the perturbations, induced by beta-purothionin, of the polar and nonpolar regions of the phospholipid bilayers. At low concentration of beta-purothionin, the temperature of the gel-to-fluid phase transition of DMPG increases from 24 degrees C to ~33 degrees C, in agreement with the formation of electrostatic interactions between the cationic protein and the anionic phospholipid. At higher protein concentration, the lipid transition is slightly shifted toward lower temperature and a second transition is observed below 20 degrees C, suggesting an insertion of the protein in the hydrophobic core of the lipid bilayer. The results also suggest that the presence of beta-purothionin significantly modifies the lipid packing at the surface of the bilayer to increase the accessibility of water molecules in the interfacial region. Finally, orientation measurements indicate that the alpha-helices and the beta-sheet of beta-purothionin have tilt angles of ~60 degrees and 30 degrees, respectively, relative to the normal of the ATR crystal. PMID:12324425

  16. 1H-detected 1H- 1H correlation spectroscopy of a stereo-array isotope labeled amino acid under fast magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Takahashi, Hiroki; Kainosho, Masatsune; Akutsu, Hideo; Fujiwara, Toshimichi

    2010-04-01

    The combined use of selective deuteration, stereo-array isotope labeling (SAIL), and fast magic-angle spinning effectively suppresses the 1H-1H dipolar couplings in organic solids. This method provided the high-field 1H NMR linewidths comparable to those achieved by combined rotation and multiple-pulse spectroscopy. This technique was applied to two-dimensional 1H-detected 1H-1H polarization transfer CHH experiments of valine. The signal sensitivity for the 1H-detected CHH experiments was greater than that for the 13C-detected 1H-1H polarization transfer experiments by a factor of 2-4. We obtained the 1H-1H distances in SAIL valine by CHH experiments with an accuracy of about 0.2 Å by using a theory developed for 1H-1H polarization transfer in 13C-labeled organic compounds.

  17. Characterization of heroin samples by 1H NMR and 2D DOSY 1H NMR.

    PubMed

    Balayssac, Stéphane; Retailleau, Emmanuel; Bertrand, Geneviève; Escot, Marie-Pierre; Martino, Robert; Malet-Martino, Myriam; Gilard, Véronique

    2014-01-01

    Twenty-four samples of heroin from different illicit drug seizures were analyzed using proton Nuclear Magnetic Resonance ((1)H NMR) and two-dimensional diffusion-ordered spectroscopy (2D DOSY) (1)H NMR. A careful assignment and quantification of (1)H signals enabled a comprehensive characterization of the substances present in the samples investigated: heroin, its main related impurities (6-acetylmorphine, acetylcodeine, morphine, noscapine and papaverine) and cutting agents (caffeine and acetaminophen in nearly all samples as well as lactose, lidocaine, mannitol, piracetam in one sample only), and hence to establish their spectral signatures. The good agreement between the amounts of heroin, noscapine, caffeine and acetaminophen determined by (1)H NMR and gas chromatography, the reference method in forensic laboratories, demonstrates the validity of the (1)H NMR technique. In this paper, 2D DOSY (1)H NMR offers a new approach for a whole characterization of the various components of these complex mixtures.

  18. Enhanced Y1H Assays for Arabidopis

    USDA-ARS?s Scientific Manuscript database

    Transcription regulation plays a key role in development and response to environment. To understand this mechanism, we need to know which transcription factor (TFs) would bind to which promoter, thus regulate their target gene expression. Yeast one-hybrid (Y1H) technique can be used to map this kind...

  19. Chemical Characterization and Water Content Determination of Bio-Oils Obtained from Various Biomass Species using 31P NMR Spectroscopy

    SciTech Connect

    David, K.; Ben, H.; Muzzy, J.; Feik, C.; Iisa, K.; Ragauskas, A.

    2012-03-01

    Pyrolysis is a promising approach to utilize biomass for biofuels. One of the key challenges for this conversion is how to analyze complicated components in the pyrolysis oils. Water contents of pyrolysis oils are normally analyzed by Karl Fischer titration. The use of 2-chloro-4,4,5,5,-tetramethyl-1,3,2-dioxaphospholane followed by {sup 31}P NMR analysis has been used to quantitatively analyze the structure of hydroxyl groups in lignin and whole biomass. Results: {sup 31}P NMR analysis of pyrolysis oils is a novel technique to simultaneously characterize components and analyze water contents in pyrolysis oils produced from various biomasses. The water contents of various pyrolysis oils range from 16 to 40 wt%. The pyrolysis oils obtained from Loblolly pine had higher guaiacyl content, while that from oak had a higher syringyl content. Conclusion: The comparison with Karl Fischer titration shows that {sup 31}P NMR could also reliably be used to measure the water content of pyrolysis oils. Simultaneously with analysis of water content, quantitative characterization of hydroxyl groups, including aliphatic, C-5 substituted/syringyl, guaiacyl, p-hydroxyl phenyl and carboxylic hydroxyl groups, could also be provided by {sup 31}P NMR analysis.

  20. Anisotropic indirect nuclear spin-spin coupling in InP: 31P CP NMR study under slow MAS condition

    NASA Astrophysics Data System (ADS)

    Iijima, Takahiro; Hashi, Kenjiro; Goto, Atsushi; Shimizu, Tadashi; Ohki, Shinobu

    2006-02-01

    The indirect nuclear spin-spin interaction tensor between neighboring 113,115In- 31P spins in Fe-doped InP semiconductor has been studied by 31P NMR spectra measured using CP of 113In → 31P and 115In → 31P under slow MAS condition. The isotropic ( Jiso) and anisotropic ( Janiso = 2/3[ J∥ - J⊥]) parts of the indirect interaction tensor are obtained from the spectral simulation. The acceptable combinations of these values are found to be as follows: ( Jiso, Janiso) = (224 ± 5, 500 ± 100 Hz) or (-224 ± 5, 2100 ± 100 Hz). Although, the coupling constants estimated in this study are slightly different from previously reported values of ∣ Jiso∣ = 350 Hz, Janiso = 1298 Hz [M. Engelsberg, R.E. Norberg, Phys. Rev. B 5 (1972) 3395] and of ∣ Jiso∣ = 225 ± 10, Janiso = (813 ± 50) or (1733 ± 50) Hz [M. Tomaselli et al., Phys. Rev. B 58 (1998) 8627], all of these has the trend that Janiso is rather larger than Jiso.

  1. Forms and lability of phosphorus in algae and aquatic macrophytes characterized by solution 31P NMR coupled with enzymatic hydrolysis

    USDA-ARS?s Scientific Manuscript database

    Increased information on forms and lability of phosphorus (P) in aquatic macrophytes and algae is crucial for better understanding of P biogeochemical cycling in eutrophic lakes. In this work, solution 31P nuclear magnetic resonance (NMR) spectroscopy coupled with enzymatic hydrolysis (EH) was used ...

  2. Detergent-like properties of magainin antibiotic peptides: a 31P solid-state NMR spectroscopy study.

    PubMed

    Bechinger, Burkhard

    2005-06-15

    (31)P solid-state NMR spectroscopy has been used to investigate the macroscopic phase behavior of phospholipid bilayers in the presence of increasing amounts of magainin antibiotic peptides. Addition of >1 mol% magainin 2 to gel-phase DMPC or liquid crystalline POPC membranes respectively, results in (31)P NMR spectra that are characterized by the coexistence of isotropic signals and line shapes typical for phospholipid bilayers. The isotropic signal intensity is a function of temperature and peptide concentration. At peptide concentrations >4 mol% of the resulting phospholipid (31)P NMR spectra are characteristic of magnetically oriented POPC bilayers suggesting the formation of small disk-like micelles or perforated sheets. In contrast, addition of magainin to acidic phospholipids results in homogenous bilayer-type (31)P NMR spectra with reduced chemical shift anisotropies. The results presented are in good agreement with the interfacial insertion of magainin helices with an alignment parallel to the surface of the phospholipid bilayers. The resulting curvature strain results in detergent-like properties of the amphipathic helical peptides.

  3. Simultaneous determination of phenolic compounds and triterpenic acids in oregano growing wild in Greece by 31P NMR spectroscopy.

    PubMed

    Agiomyrgianaki, Alexia; Dais, Photis

    2012-11-01

    (31)P nuclear magnetic resonance (NMR) spectroscopy was used to detect and quantify simultaneously a large number of phenolic compounds and the two triterpenic acids, ursolic acid and oleanolic acid, extracted from two oregano species Origanum onites and Origanum vulgare ssp. Hirtum using two different organic solvents ethanol and ethyl acetate. This analytical method is based on the derivatization of the hydroxyl and carboxyl groups of these compounds with the phosphorous reagent 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxa phospholane and the identification of the phosphitylated compounds on the basis of the (31)P chemical shifts. Unambiguous assignment of the (31)P NMR chemical shifts of the dihydroxy- and polyhydroxy-phenols in oregano species as well as those of the triterpenic acids was achieved upon comparison with the chemical shifts of model compounds assigned by using two-dimensional NMR techniques. Furthermore, the integration of the appropriate signals of the hydroxyl derivatives in the corresponding (31)P NMR spectra and the use of the phosphitylated cyclohexanol as an internal standard allowed the quantification of these compounds. The validity of this technique for quantitative measurements was thoroughly examined.

  4. Metabolism of {sup 76}Se-methylselenocysteine compared with that of {sup 77}Se-selenomethionine and {sup 82}Se-selenite

    SciTech Connect

    Suzuki, Kazuo T. . E-mail: ktsuzuki@p.chiba-u.ac.jp; Doi, Chiaki; Suzuki, Noriyuki

    2006-12-01

    Se-Methylated selenoamino acids, Se-methylselenocysteine (MeSeCys) and selenomethionine (SeMet), are chemically inert storage forms of selenium in selenium-accumulators, and a nutritional and supplemental source. The metabolic pathway for MeSeCys was precisely traced by referring to those for SeMet and selenite by applying a new tracer method involving multiple homo-elemental stable isotopes. Male Wistar rats were depleted of endogenous natural abundance selenium with a single {sup 8}Se-enriched isotope, and then {sup 76}Se-MeSeCys, {sup 77}Se-SeMet and {sup 82}Se-selenite were orally administered simultaneously at 25 {mu}g Se/kg body weight each. Organs and body fluids were obtained at 3, 6, 9 and 12 h, and 1 and 2 days later, and subjected to speciation analysis. The main characteristics of the metabolism were as follows; MeSeCys was incorporated into selenoprotein P slightly more than or at a comparable level to that of SeMet but less than that of selenite. MeSeCys and SeMet but not selenite was taken up by organs in their intact forms. MeSeCys and SeMet were delivered specifically to the pancreas and present in a form bound to an identical or similar protein. Trimethylselenonium (TMSe) was only produced from MeSeCys, i.e., not from SeMet or selenite, in the kidneys. Both selenosugars A and B of MeSeCys, SeMet and selenite origin were detected in the liver but only selenosugar B in the kidneys. These results suggest that MeSeCys can be a similar or better selenium source than SeMet, and supplies methylselenol much more efficiently in organs than SeMet and selenite. TMSe was produced much efficiently from MeSeCys than from SeMet and selenite, suggesting a role of methylselenol through the {beta}-lyase reaction in the metabolism of Se-methylated selenoamino acids.

  5. Sublethal actions of copper in abalone (Haliotis rufescens) as characterized by in vivo 31P NMR.

    PubMed

    Viant, Mark R; Walton, Jeffrey H; TenBrook, Patti L; Tjeerdema, Ronald S

    2002-05-01

    The sublethal biochemical actions of copper in live, intact red abalone (Haliotis rufescens) were characterized by in vivo 31P nuclear magnetic resonance spectroscopy (NMR). This non-invasive technique is ideal for examining cellular respiration since critical metabolite concentrations, including phosphoarginine ([PA]), inorganic phosphate ([P(i)]) and [ATP], and the arginine kinase (AK) rate constant, can be monitored in real time. Both metabolite concentrations and enzyme rate constants were measured in abalone during 8-h exposures to 66 microg l(-1) (1.04 microM) and 126 microg l(-1) (1.98 microM) copper (as CuCl2). Significant decreases in [PA] and corresponding increases in [P(i)] resulted, while [ATP] remained constant. In controls [PA], [P(i)] and [ATP] all remained unchanged. Furthermore, both copper concentrations induced a significant elevation in the forward AK rate constant over the basal value of 0.020 +/- 0.002 s(-1). Metabolite levels and enzyme rate constants were also measured during 8-h 66 microg l(-1) copper exposures both before and after a 2-week subchronic exposure to 36 microg l(-1) (0.57 microM) copper. Unlike before the subchronic exposure, no significant changes in [PA], [P(i)] or [ATP] were observed after the 36 microg l(-1) copper treatment, compared with controls. This induced tolerance was also evident from the forward AK rate constant data. Finally, copper accumulation was determined in gill, digestive gland and foot muscle samples. Whereas acute exposure only led to significant accumulation in the gill, copper levels in subchronically exposed abalone were significantly elevated in both the gill and digestive gland, and marginally so in foot muscle. Overall, the gill appears to be the primary site of copper accumulation and toxicity, while the foot and adductor muscles maybe secondarily impacted. The observed metabolic changes may result from insufficient oxygen delivery to the muscles, resulting from mucus accumulation or cytological

  6. Regional Differences in Muscle Energy Metabolism in Human Muscle by 31P-Chemical Shift Imaging.

    PubMed

    Kime, Ryotaro; Kaneko, Yasuhisa; Hongo, Yoshinori; Ohno, Yusuke; Sakamoto, Ayumi; Katsumura, Toshihito

    2016-01-01

    Previous studies have reported significant region-dependent differences in the fiber-type composition of human skeletal muscle. It is therefore hypothesized that there is a difference between the deep and superficial parts of muscle energy metabolism during exercise. We hypothesized that the inorganic phosphate (Pi)/phosphocreatine (PCr) ratio of the superficial parts would be higher, compared with the deep parts, as the work rate increases, because the muscle fiber-type composition of the fast-type may be greater in the superficial parts compared with the deep parts. This study used two-dimensional 31Phosphorus Chemical Shift Imaging (31P-CSI) to detect differences between the deep and superficial parts of the human leg muscles during dynamic knee extension exercise. Six healthy men participated in this study (age 27±1 year, height 169.4±4.1 cm, weight 65.9±8.4 kg). The experiments were carried out with a 1.5-T superconducting magnet with a 5-in. diameter circular surface coil. The subjects performed dynamic one-legged knee extension exercise in the prone position, with the transmit-receive coil placed under the right quadriceps muscles in the magnet. The subjects pulled down an elastic rubber band attached to the ankle at a frequency of 0.25, 0.5 and 1 Hz for 320 s each. The intracellular pH (pHi) was calculated from the median chemical shift of the Pi peak relative to PCr. No significant difference in Pi/PCr was observed between the deep and the superficial parts of the quadriceps muscles at rest. The Pi/PCr of the superficial parts was not significantly increased with increasing work rate. Compared with the superficial areas, the Pi/PCr of the deep parts was significantly higher (p<0.05) at 1 Hz. The pHi showed no significant difference between the two parts. These results suggest that muscle oxidative metabolism is different between deep and superficial parts of quadriceps muscles during dynamic exercise.

  7. Towards the versatile DFT and MP2 computational schemes for 31P NMR chemical shifts taking into account relativistic corrections.

    PubMed

    Fedorov, Sergey V; Rusakov, Yury Yu; Krivdin, Leonid B

    2014-11-01

    The main factors affecting the accuracy and computational cost of the calculation of (31)P NMR chemical shifts in the representative series of organophosphorous compounds are examined at the density functional theory (DFT) and second-order Møller-Plesset perturbation theory (MP2) levels. At the DFT level, the best functionals for the calculation of (31)P NMR chemical shifts are those of Keal and Tozer, KT2 and KT3. Both at the DFT and MP2 levels, the most reliable basis sets are those of Jensen, pcS-2 or larger, and those of Pople, 6-311G(d,p) or larger. The reliable basis sets of Dunning's family are those of at least penta-zeta quality that precludes their practical consideration. An encouraging finding is that basically, the locally dense basis set approach resulting in a dramatic decrease in computational cost is justified in the calculation of (31)P NMR chemical shifts within the 1-2-ppm error. Relativistic corrections to (31)P NMR absolute shielding constants are of major importance reaching about 20-30 ppm (ca 7%) improving (not worsening!) the agreement of calculation with experiment. Further better agreement with the experiment by 1-2 ppm can be obtained by taking into account solvent effects within the integral equation formalism polarizable continuum model solvation scheme. We recommend the GIAO-DFT-KT2/pcS-3//pcS-2 scheme with relativistic corrections and solvent effects taken into account as the most versatile computational scheme for the calculation of (31)P NMR chemical shifts characterized by a mean absolute error of ca 9 ppm in the range of 550 ppm.

  8. Noninvasive Monitoring of Training Induced Muscle Adaptation with 31P-MRS: Fibre Type Shifts Correlate with Metabolic Changes

    PubMed Central

    Hoff, Eike; Brechtel, Lars; Strube, Patrick; Konstanczak, Paul; Stoltenburg-Didinger, Gisela; Perka, Carsten; Putzier, Michael

    2013-01-01

    Purpose. To evaluate training induced metabolic changes noninvasively with 31P magnetic resonance spectroscopy (31P-MRS) for measuring muscle fibre type adaptation. Methods. Eleven volunteers underwent a 24-week training, consisting of speed-strength, endurance, and detraining (each 8 weeks). Prior to and following each training period, needle biopsies and 31P-MRS of the resting gastrocnemius muscle were performed. Fibre type distribution was analyzed histologically and tested for correlation with the ratios of high energy phosphates ([PCr]/[Pi], [PCr]/[βATP] and [PCr + Pi]/[βATP]). The correlation between the changes of the 31P-MRS parameters during training and the resulting changes in fibre composition were also analysed. Results. We observed an increased type-II-fibre proportion after speed-strength and detraining. After endurance training the percentage of fast-twitch fibres was reduced. The progression of the [PCr]/[Pi]-ratio was similar to that of the fast-twitch fibres during the training. We found a correlation between the type-II-fibre proportion and [PCr]/[Pi] (r = 0.70, P < 0.01) or [PCr]/[βATP] (r = 0.69, P < 0.01); the correlations between its changes (delta) and the fibre-shift were significant as well (delta[PCr]/[Pi] r = 0.66, delta[PCr]/[βATP] r = 0.55, P < 0.01). Conclusion. Shifts in fibre type composition and high energy phosphate metabolite content covary in human gastrocnemius muscle. Therefore 31P-MRS might be a feasible method for noninvasive monitoring of exercise-induced fibre type transformation. PMID:23998123

  9. Calculating the response of NMR shielding tensor σ(31P) and 2J(31P,13C) coupling constants in nucleic acid phosphate to coordination of the Mg2+ cation.

    PubMed

    Benda, Ladislav; Schneider, Bohdan; Sychrovský, Vladimír

    2011-03-24

    Dependence of NMR (31)P shielding tensor and (2)J(P,C) coupling constants on solvation of nucleic acid phosphate by Mg(2+) and water was studied using methods of bioinformatic structural analyses of crystallographic data and DFT B3LYP calculations of NMR parameters. The effect of solvent dynamics on NMR parameters was calculated using molecular dynamic. The NMR calculations for representative solvation patterns determined in crystals of B-DNA and A-RNA molecules pointed out the crucial importance of local Mg(2+) coordination geometry, including hydration by explicit water molecules and necessity of dynamical averaging over the solvent reorientation. The dynamically averaged (31)P chemical shift decreased by 2-9.5 ppm upon Mg(2+) coordination, the chemical shielding anisotropy increased by 0-20 ppm, and the (2)J(P,C5') coupling magnitude decreased by 0.2-1.8 Hz upon Mg(2+) coordination. The calculated decrease of the (31)P chemical shift is in excellent agreement with the 1.5-10 ppm decrease of the phosphorothioate (31)P chemical shift upon Cd(2+) coordination probed experimentally in hammerhead ribozyme (Suzumura; et al. J. Am. Chem. Soc. 2002, 124, 8230-8236; Osborne; et al., Biochemistry 2009, 48, 10654-10664). None of the dynamically averaged NMR parameters unequivocally distinguishes the site-specific Mg(2+) coordination to one of the two nonesterified phosphate oxygen atoms of the phosphate determined by bioinformatic analyses. By comparing the limit cases of static and dynamically averaged solvation, we propose that mobility of the solvent has a dramatic impact on NMR parameters of nucleic acid phosphate and must be taken into account for their accurate modeling.

  10. Site-specificity of ethanol-induced dephosphorylation of rat hepatocyte keratins 8 and 18: A 31P NMR study.

    PubMed

    Eckert, B S; Yeagle, P L

    1996-01-01

    Chronic feeding of ethanol to rats results in disorganization of the keratin intermediate filament network within hepatocytes. Previous studies from this laboratory have shown that intermediate filament organization in cultured cells is related to the phosphorylation state of the proteins. Therefore, we have examined the phosphorylation state of hepatocyte keratins from control and ethanol-fed rats. Feeding ethanol to rats results in dephosphorylation of one site on keratin 8 and one site on keratin 18 at all time points beginning with 6 weeks of ethanol treatment. Dephosphorylation was detected by phosphate analysis and by two-dimensional electrophoresis in which a change in isoelectric point of keratins from ethanol-fed rats was observed. These observations indicate that dephosphorylation of keratins in ethanol-fed animals may be an early step in alcoholic hepatitis which has occurred by 6 weeks of ethanol treatment. To further characterize keratin dephosphorylation in ethanol-fed rats, we used 31P NMR spectroscopy to classify the dephosphorylation site(s). Hepatocyte keratins were purified and solubilized in 9.5 M urea, 10 mM Tris-Cl, pH 8.1. 31P NMR spectra were obtained at 109 MHz, in 10 mm tubes at 30 degrees C. Samples of hepatocyte keratins were phosphorylated with A-kinase, protein kinase C, casein kinase II or Ca/CAM kinase and these samples were analyzed by 31P NMR spectroscopy. The resulting spectra were used as standards to compare the 31P chemical shifts of the resonances produced by these kinases with the phosphorus resonances of control and experimental samples. The 31P NMR spectrum of control hepatocyte keratins shows three resonances at 0.7, 4 and 5 ppm. In vitro phosphorylation by A-kinase produces a resonance at 4 ppm which is distinctly different from the resonance produced by each of the other kinases. In hepatocyte keratins from ethanol-fed animals, the resonance at 4 ppm was missing from the spectrum. These observations indicate that the

  11. 2D 31P solid state NMR spectroscopy, electronic structure and thermochemistry of PbP7

    NASA Astrophysics Data System (ADS)

    Benndorf, Christopher; Hohmann, Andrea; Schmidt, Peer; Eckert, Hellmut; Johrendt, Dirk; Schäfer, Konrad; Pöttgen, Rainer

    2016-03-01

    Phase pure polycrystalline PbP7 was prepared from the elements via a lead flux. Crystalline pieces with edge-lengths up to 1 mm were obtained. The assignment of the previously published 31P solid state NMR spectrum to the seven distinct crystallographic sites was accomplished by radio-frequency driven dipolar recoupling (RFDR) experiments. As commonly found in other solid polyphosphides there is no obvious correlation between the 31P chemical shift and structural parameters. PbP7 decomposes incongruently under release of phosphorus forming liquid lead as remainder. The thermal decomposition starts at T>550 K with a vapor pressure almost similar to that of red phosphorus. Electronic structure calculations reveal PbP7 as a semiconductor according to the Zintl description and clearly shows the stereo-active Pb-6s2 lone pairs in the electron localization function ELF.

  12. 31P and 19F NMR studies of glycophorin-reconstituted membranes: preferential interaction of glycophorin with phosphatidylserine

    SciTech Connect

    Ong, R.L.

    1984-01-01

    Glycophorin A, a major glycoprotein of the erythrocyte membrane, has been incorporated into small unilamellar vesicles composed of a variety of pure and mixed phospholipids. Nuclear spin labels including 31P and 19F have been used at natural abundance or have been synthetically incorporated in lipids to act as probes of lipid-protein interaction. Interactions produce broadening of resonances in several cases and it can be used to demonstrate preferential interaction of certain lipids with glycophorin. 31P and 19F probes show a strong preferential interaction of glycophorin with phosphatidylserine over phosphatidylcholine. There is some evidence that interactions are more pronounced at the inner surface of the bilayer and these results are rationalized in terms of the asymmetric distribution of protein and lipid.

  13. A simple ergometer for 31P NMR spectroscopy during dynamic forearm exercise in a whole body magnetic resonance imaging system.

    PubMed

    Nishijima, H; Nishida, M; Anzai, T; Yonezawa, K; Fukuda, H; Sato, I; Yasuda, H

    1992-03-01

    The purpose of this study was to construct a simple ergometer for the 31P NMR spectroscopic study of dynamic forearm exercise in a whole body magnetic resonance imaging system and to evaluate the total system and the physiological response to this type of exercise using a multistage protocol. The system consisted of a completely nonmagnetic assembly including a rope, pulley and weights. The work of lifting weights was quantitated. The exercise protocol of 1-min increments in work load enabled subjects to reach maximal effort. Phosphocreatine decreased linearly with an increase in work load and was accompanied by a fall in pH and an increase in lactate level in the antecubital vein of the exercising forearm; concomitantly, there was a slight increase in whole body oxygen uptake and heart rate. Spectroscopy gave reproducible results using this exercise protocol. These results demonstrate that this system provides a reliable means for performing 31P magnetic resonance spectroscopy studies during forearm exercise.

  14. Complete (1) H NMR assignment of cedranolides.

    PubMed

    Perez-Hernandez, Nury; Gordillo-Roman, Barbara; Arrieta-Baez, Daniel; Cerda-Garcia-Rojas, Carlos M; Joseph-Nathan, Pedro

    2017-03-01

    Complete and unambiguous (1) H NMR chemical shift assignment of α-cedrene (2) and cedrol (9), as well as for α-pipitzol (1), isocedrol (10), and the six related compounds 3-8 has been established by iterative full spin analysis using the PERCH NMR software (PERCH Solutions Ltd., Kuopio, Finland). The total sets of coupling constants are described and correlated with the conformational equilibria of the five-membered ring of 1-10, which were calculated using the complete basis set method. Copyright © 2015 John Wiley & Sons, Ltd.

  15. Crystallinity and compositional changes in carbonated apatites: Evidence from {sup 31}P solid-state NMR, Raman, and AFM analysis

    SciTech Connect

    McElderry, John-David P.; Zhu, Peizhi; Mroue, Kamal H.; Xu, Jiadi; Pavan, Barbara; Fang, Ming; Zhao, Guisheng; McNerny, Erin; Kohn, David H.; Franceschi, Renny T.; Holl, Mark M.Banaszak; Tecklenburg, Mary M.J.; Ramamoorthy, Ayyalusamy; Morris, Michael D.

    2013-10-15

    Solid-state (magic-angle spinning) NMR spectroscopy is a useful tool for obtaining structural information on bone organic and mineral components and synthetic model minerals at the atomic-level. Raman and {sup 31}P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse {sup 31}P NMR linewidth and inverse Raman PO{sub 4}{sup 3−}ν{sub 1} bandwidth were both correlated with powder XRD c-axis crystallinity over the 0.3–10.3 wt% CO{sub 3}{sup 2−} range investigated. Comparison with bone powder crystallinities showed agreement with values predicted by NMR and Raman calibration curves. Carbonate content was divided into two domains by the {sup 31}P NMR chemical shift frequency and the Raman phosphate ν{sub 1} band position. These parameters remain stable except for an abrupt transition at 6.5 wt% carbonate, a composition which corresponds to an average of one carbonate per unit cell. This near-binary distribution of spectroscopic properties was also found in AFM-measured particle sizes and Ca/P molar ratios by elemental analysis. We propose that this transition differentiates between two charge-balancing ion-loss mechanisms as measured by Ca/P ratios. These results define a criterion for spectroscopic characterization of B-type carbonate substitution in apatitic minerals. - Graphical abstract: Carbonated apatite shows an abrupt change in spectral (NMR, Raman) and morphological (AFM) properties at a composition of about one carbonate substitution per unit cell. Display Omitted - Highlights: • Crystallinity (XRD), particle size (AFM) of carbonated apatites and bone mineral. • Linear relationships among crystallinity, {sup 31}P NMR and Raman inverse bandwidths. • Low and high carbonated apatites use different charge-balancing ion-loss mechanism.

  16. In-Vivo 31P NMR Spectroscopy Assessment of Skeletal Muscle Bioenergetics after Spinal Cord Contusion in Rats

    PubMed Central

    Shah, Prithvi K; Ye, Fan; Liu, Min; Jayaraman, Arun; Walter, Glenn; Vandenborne, Krista

    2014-01-01

    Purpose Muscle paralysis after spinal cord injury (SCI) leads to muscle atrophy, enhanced muscle fatigue, and increased energy demands for functional activities. Phosphorus magnetic resonance spectroscopy (31P-MRS) offers a unique non-invasive alternative of measuring energy metabolism in skeletal muscle and is especially suitable for longitudinal investigations. We determined the impact of spinal cord contusion on in-vivo muscle bioenergetics of the rat hindlimb muscle using 31P-MRS. Methods A moderate spinal cord contusion injury (cSCI) was induced at the T8-T10 thoracic spinal segments. 31P-MRS measurements were performed weekly in the rat hindlimb muscles for three weeks. Spectra were acquired in a Bruker 11T/470 MHz spectrometer using a 31P surface coil. The sciatic nerve was electrically stimulated by subcutaneous needle electrodes. Spectra were acquired at rest (5 min), during stimulation (6 min), and recovery (20 min). Phosphocreatine (PCr) depletion rates and the pseudo-first-order rate constant for PCr recovery (kPCr) were determined. The maximal rate of PCr resynthesis, the in-vivo maximum oxidative capacity (Vmax) and oxidative ATP synthesis rate (Qmax), were subsequently calculated. Results One week after cSCI, there was a decline in the resting [TCr] of the paralyzed muscle. There was a significant reduction (~24%) in kPCr measures of the paralyzed muscle, maximum in-vivo mitochondrial capacity (Vmax) and the maximum oxidative ATP synthesis rate (Qmax) at 1week post-cSCI. Conclusions Using in-vivo MRS assessments, we reveal an acute oxidative metabolic defect in the paralyzed hind limb muscle. These altered muscle bioenergetics might contribute to the host of motor dysfunctions seen after cSCI. PMID:24399112

  17. Distinguishing Bicontinuous Lipid Cubic Phases from Isotropic Membrane Morphologies Using 31P Solid-State NMR Spectroscopy

    PubMed Central

    Yang, Yu; Yao, Hongwei

    2015-01-01

    Nonlamellar lipid membranes are frequently induced by proteins that fuse, bend, and cut membranes. Understanding the mechanism of action of these proteins requires the elucidation of the membrane morphologies that they induce. While hexagonal phases and lamellar phases are readily identified by their characteristic solid-state NMR lineshapes, bicontinuous lipid cubic phases are more difficult to discern, since the static NMR spectra of cubic-phase lipids consist of an isotropic 31P or 2H peak, indistinguishable from the spectra of isotropic membrane morphologies such as micelles and small vesicles. To date, small-angle X-ray scattering is the only method to identify bicontinuous lipid cubic phases. To explore unique NMR signatures of lipid cubic phases, we first describe the orientation distribution of lipid molecules in cubic phases and simulate the static 31P chemical shift lineshapes of oriented cubic-phase membranes in the limit of slow lateral diffusion. We then show that 31P T2 relaxation times differ significantly between isotropic micelles and cubic-phase membranes: the latter exhibit two-orders-of magnitude shorter T2 relaxation times. These differences are explained by the different timescales of lipid lateral diffusion on the cubic-phase surface versus the timescales of micelle tumbling. Using this relaxation NMR approach, we investigated a DOPE membrane containing the transmembrane domain (TMD) of a viral fusion protein. The static 31P spectrum of DOPE shows an isotropic peak, whose T2 relaxation times correspond to that of a cubic phase. Thus, the viral fusion protein TMD induces negative Gaussian curvature, which is an intrinsic characteristic of cubic phases, to the DOPE membrane. This curvature induction has important implications to the mechanism of virus-cell fusion. This study establishes a simple NMR diagnostic probe of lipid cubic phases, which is expected to be useful for studying many protein-induced membrane remodeling phenomena in biology

  18. Analysis of monoglycerides, diglycerides, sterols, and free fatty acids in coconut (Cocos nucifera L.) oil by 31P NMR spectroscopy.

    PubMed

    Dayrit, Fabian M; Buenafe, Olivia Erin M; Chainani, Edward T; de Vera, Ian Mitchelle S

    2008-07-23

    Phosphorus-31 nuclear magnetic resonance spectroscopy ( (31)P NMR) was used to differentiate virgin coconut oil (VCO) from refined, bleached, deodorized coconut oil (RCO). Monoglycerides (MGs), diglycerides (DGs), sterols, and free fatty acids (FFAs) in VCO and RCO were converted into dioxaphospholane derivatives and analyzed by (31)P NMR. On the average, 1-MG was found to be higher in VCO (0.027%) than RCO (0.019%). 2-MG was not detected in any of the samples down to a detection limit of 0.014%. On the average, total DGs were lower in VCO (1.55%) than RCO (4.10%). When plotted in terms of the ratio [1,2-DG/total DGs] versus total DGs, VCO and RCO samples grouped separately. Total sterols were higher in VCO (0.096%) compared with RCO (0.032%), and the FFA content was 8 times higher in VCO than RCO (0.127% vs 0.015%). FFA determination by (31)P NMR and titration gave comparable results. Principal components analysis shows that the 1,2-DG, 1,3-DG, and FFAs are the most important parameters for differentiating VCO from RCO.

  19. Improvement of (31)P NMR spectral resolution by 8-hydroxyquinoline precipitation of paramagnetic Fe and Mn in environmental samples.

    PubMed

    Ding, Shiming; Xu, Di; Li, Bin; Fan, Chengxin; Zhang, Chaosheng

    2010-04-01

    Solution (31)P nuclear magnetic resonance (NMR) spectroscopy is currently the main method for the characterization of phosphorus (P) forms in environment samples. However, identification and quantification of P compounds may be hampered by poor resolution of spectra caused by paramagnetic Fe and Mn. In this study, a novel technique was developed to improve spectral resolution by removing paramagnetic Fe and Mn from alkaline extracts via 8-hydroxyquinoline (8-HOQ) precipitation. Batch experiments showed that both Fe and Mn were effectively removed by the precipitation at pH 9.0, with the removal efficiencies of 83-91% for Fe and 67-78% for Mn from the extracts of five different environmental samples, while little effect was found on concentration of total P. The (31)P NMR analysis of a model P solution showed that addition of 8-HOQ and its precipitation with metal ions did not alter P forms. Further analyses of the five extracts with (31)P NMR spectroscopy demonstrated that the 8-HOQ precipitation was an ideal method compared with the present postextraction techniques, such as bicarbonate dithionate (BD), EDTA and Chelex-100 treatments, by improving spectral resolution to a large extent with no detrimental effects on P forms.

  20. Ab initio and DFT study of 31P-NMR chemical shifts of sphingomyelin and dihydrosphingomyelin lipid molecule

    NASA Astrophysics Data System (ADS)

    Sugimori, K.; Kawabe, H.; Nagao, H.; Nishikawa, K.

    One of the phospholipids, sphingomyelin (SM, N-acyl-sphingosine-1-phosphorylcholine) is the most abundant component of mammalian membranes in brain, nervous tissues, and human ocular lens. It plays an important role for apoptosis, aging, and signal transduction. Recently, Yappert and coworkers have shown that human lens sphingomyelin and its hydrogenated derivative, dihydrosphingomyelin (DHSM) are interacted with Ca2+ ions to develop human cataracts. Previously, we have investigated conformational differences between an isolated SM/DHSM molecule and Ca2+-coordinated form by using density functional theory (DFT) for geometry optimization and normal mode analysis. As a result, one of stable conformers of SMs has a hydrogen bonding between hydroxyl group and phosphate group, whereas another conformer has a hydrogen bonding between hydroxyl and phosphate amide group. In this study, 31P-Nuclear Magnetic Resonance (NMR) shielding constants of the obtained conformers are investigated by using ab initio and DFT with NMR-gauge invariant atomic orbitals (NMR-GIAO) calculations. The experimental 31P-NMR chemical shifts of SMs and DHSMs have significant small value around 0.1 ppm. We consider the relative conformational changes between SMs and DHSMs affect the slight deviations of 31P-NMR chemical shifts, and discuss intramolecular hydrogen bondings and the solvent effect in relation to NMR experimental reference.

  1. Forms and Lability of Phosphorus in Algae and Aquatic Macrophytes Characterized by Solution 31P NMR Coupled with Enzymatic Hydrolysis

    PubMed Central

    Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; He, Zhongqi; Zhang, Chen; Giesy, John P.

    2016-01-01

    Solution Phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy coupled with enzymatic hydrolysis (EH) with commercially available phosphatases was used to characterize phosphorus (P) compounds in extracts of the dominant aquatic macrophytes and algae in a eutrophic lake. Total extractable organic P (Po) concentrations ranged from 504 to 1643 mg kg−1 and 2318 to 8395 mg kg−1 for aquatic macrophytes and algae, respectively. Using 31P NMR spectroscopy, 11 Po species were detected in the mono- and diester region. Additionally, orthophosphate, pyrophosphate and phosphonates were also detected. Using EH, phytate-like P was identified as the prevalent class of enzyme-labile Po, followed by labile monoester- and diester-P. Comparison of the NMR and EH data indicated that the distribution pattern of major P forms in the samples determined by the two methods was similar (r = 0.712, p < 0.05). Additional 31P NMR spectroscopic analysis of extracts following EH showed significant decreases in the monoester and pyrophosphate regions, with a corresponding increase in the orthophosphate signal, as compared to unhydrolyzed extracts. Based on these quantity and hydrolysis data, we proposed that recycling of Po in vegetative biomass residues is an important mechanism for long-term self-regulation of available P for algal blooming in eutrophic lakes. PMID:27849040

  2. Crystallinity and compositional changes in carbonated apatites: Evidence from (31)P solid-state NMR, Raman, and AFM analysis.

    PubMed

    McElderry, John-David P; Zhu, Peizhi; Mroue, Kamal H; Xu, Jiadi; Pavan, Barbara; Fang, Ming; Zhao, Guisheng; McNerny, Erin; Kohn, David H; Franceschi, Renny T; Holl, Mark M Banaszak; Tecklenburg, Mary M J; Ramamoorthy, Ayyalusamy; Morris, Michael D

    2013-10-01

    Solid-state (magic-angle spinning) NMR spectroscopy is a useful tool for obtaining structural information on bone organic and mineral components and synthetic model minerals at the atomic-level. Raman and (31)P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse (31)P NMR linewidth and inverse Raman PO4(3-) ν1 bandwidth were both correlated with powder XRD c-axis crystallinity over the 0.3-10.3 wt% CO3(2-) range investigated. Comparison with bone powder crystallinities showed agreement with values predicted by NMR and Raman calibration curves. Carbonate content was divided into two domains by the (31)P NMR chemical shift frequency and the Raman phosphate ν1 band position. These parameters remain stable except for an abrupt transition at 6.5 wt% carbonate, a composition which corresponds to an average of one carbonate per unit cell. This near-binary distribution of spectroscopic properties was also found in AFM-measured particle sizes and Ca/P molar ratios by elemental analysis. We propose that this transition differentiates between two charge-balancing ion-loss mechanisms as measured by Ca/P ratios. These results define a criterion for spectroscopic characterization of B-type carbonate substitution in apatitic minerals.

  3. Crystallinity and compositional changes in carbonated apatites: Evidence from 31P solid-state NMR, Raman, and AFM analysis

    PubMed Central

    McElderry, John-David P.; Zhu, Peizhi; Mroue, Kamal H.; Xu, Jiadi; Pavan, Barbara; Fang, Ming; Zhao, Guisheng; McNerny, Erin; Kohn, David H.; Franceschi, Renny T.; Holl, Mark M. Banaszak; Tecklenburg, Mary M.J.; Ramamoorthy, Ayyalusamy; Morris, Michael D.

    2013-01-01

    Solid-state (magic-angle spinning) NMR spectroscopy is a useful tool for obtaining structural information on bone organic and mineral components and synthetic model minerals at the atomic-level. Raman and 31P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse 31P NMR linewidth and inverse Raman PO43− ν1 bandwidth were both correlated with powder XRD c-axis crystallinity over the 0.3–10.3 wt% CO32− range investigated. Comparison with bone powder crystallinities showed agreement with values predicted by NMR and Raman calibration curves. Carbonate content was divided into two domains by the 31P NMR chemical shift frequency and the Raman phosphate ν1 band position. These parameters remain stable except for an abrupt transition at 6.5 wt% carbonate, a composition which corresponds to an average of one carbonate per unit cell. This near-binary distribution of spectroscopic properties was also found in AFM-measured particle sizes and Ca/P molar ratios by elemental analysis. We propose that this transition differentiates between two charge-balancing ion-loss mechanisms as measured by Ca/P ratios. These results define a criterion for spectroscopic characterization of B-type carbonate substitution in apatitic minerals. PMID:24273344

  4. Forms and Lability of Phosphorus in Algae and Aquatic Macrophytes Characterized by Solution 31P NMR Coupled with Enzymatic Hydrolysis

    NASA Astrophysics Data System (ADS)

    Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; He, Zhongqi; Zhang, Chen; Giesy, John P.

    2016-11-01

    Solution Phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy coupled with enzymatic hydrolysis (EH) with commercially available phosphatases was used to characterize phosphorus (P) compounds in extracts of the dominant aquatic macrophytes and algae in a eutrophic lake. Total extractable organic P (Po) concentrations ranged from 504 to 1643 mg kg-1 and 2318 to 8395 mg kg-1 for aquatic macrophytes and algae, respectively. Using 31P NMR spectroscopy, 11 Po species were detected in the mono- and diester region. Additionally, orthophosphate, pyrophosphate and phosphonates were also detected. Using EH, phytate-like P was identified as the prevalent class of enzyme-labile Po, followed by labile monoester- and diester-P. Comparison of the NMR and EH data indicated that the distribution pattern of major P forms in the samples determined by the two methods was similar (r = 0.712, p < 0.05). Additional 31P NMR spectroscopic analysis of extracts following EH showed significant decreases in the monoester and pyrophosphate regions, with a corresponding increase in the orthophosphate signal, as compared to unhydrolyzed extracts. Based on these quantity and hydrolysis data, we proposed that recycling of Po in vegetative biomass residues is an important mechanism for long-term self-regulation of available P for algal blooming in eutrophic lakes.

  5. Energy Deregulation Precedes Alteration in Heart Energy Balance in Young Spontaneously Hypertensive Rats: A Non Invasive In Vivo 31P-MR Spectroscopy Follow-Up Study

    PubMed Central

    Deschodt-Arsac, Veronique; Arsac, Laurent; Magat, Julie; Naulin, Jerome; Quesson, Bruno; Dos Santos, Pierre

    2016-01-01

    Introduction Gradual alterations in cardiac energy balance, as assessed by the myocardial PCr/ATP-ratio, are frequently associated with the development of cardiac disease. Despite great interest for the follow-up of myocardial PCr and ATP content, cardiac MR-spectroscopy in rat models in vivo is challenged by sensitivity issues and cross-contamination from other organs. Methods Here we combined MR-Imaging and MR-Spectroscopy (Bruker BioSpec 9.4T) to follow-up for the first time in vivo the cardiac energy balance in the SHR, a genetic rat model of cardiac hypertrophy known to develop early disturbances in cytosolic calcium dynamics. Results We obtained consistent 31P-spectra with high signal/noise ratio from the left ventricle in vivo by using a double-tuned (31P/1H) surface coil. Reasonable acquisition time (<3.2min) allowed assessing the PCr/ATP-ratio comparatively in SHR and age-matched control rats (WKY): i) weekly from 12 to 21 weeks of age; ii) in response to a bolus injection of the ß-adrenoreceptor agonist isoproterenol at age 21 weeks. Discussion Along weeks, the cardiac PCr/ATP-ratio was highly reproducible, steady and similar (2.35±0.06) in SHR and WKY, in spite of detectable ventricular hypertrophy in SHR. At the age 21 weeks, PCr/ATP dropped more markedly (-17.1%±0.8% vs. -3,5%±1.4%, P<0.001) after isoproterenol injection in SHR and recovered slowly thereafter (time constant 21.2min vs. 6.6min, P<0.05) despite similar profiles of tachycardia among rats. Conclusion The exacerbated PCr/ATP drop under ß-adrenergic stimulation indicates a defect in cardiac energy regulation possibly due to calcium-mediated abnormalities in the SHR heart. Of note, defects in energy regulation were present before detectable abnormalities in cardiac energy balance at rest. PMID:27622548

  6. (31)P-MRS of healthy human brain: ATP synthesis, metabolite concentrations, pH, and T1 relaxation times.

    PubMed

    Ren, Jimin; Sherry, A Dean; Malloy, Craig R

    2015-11-01

    The conventional method for measuring brain ATP synthesis is (31)P saturation transfer (ST), a technique typically dependent on prolonged pre-saturation with γ-ATP. In this study, ATP synthesis rate in resting human brain is evaluated using EBIT (exchange kinetics by band inversion transfer), a technique based on slow recovery of γ-ATP magnetization in the absence of B1 field following co-inversion of PCr and ATP resonances with a short adiabatic pulse. The unidirectional rate constant for the Pi → γ-ATP reaction is 0.21 ± 0.04 s(-1) and the ATP synthesis rate is 9.9 ± 2.1 mmol min(-1)  kg(-1) in human brain (n = 12 subjects), consistent with the results by ST. Therefore, EBIT could be a useful alternative to ST in studying brain energy metabolism in normal physiology and under pathological conditions. In addition to ATP synthesis, all detectable (31)P signals are analyzed to determine the brain concentration of phosphorus metabolites, including UDPG at around 10 ppm, a previously reported resonance in liver tissues and now confirmed in human brain. Inversion recovery measurements indicate that UDPG, like its diphosphate analogue NAD, has apparent T1 shorter than that of monophosphates (Pi, PMEs, and PDEs) but longer than that of triphosphate ATP, highlighting the significance of the (31)P-(31)P dipolar mechanism in T1 relaxation of polyphosphates. Another interesting finding is the observation of approximately 40% shorter T1 for intracellular Pi relative to extracellular Pi, attributed to the modulation by the intracellular phosphoryl exchange reaction Pi ↔ γ-ATP. The sufficiently separated intra- and extracellular Pi signals also permit the distinction of pH between intra- and extracellular environments (pH 7.0 versus pH 7.4). In summary, quantitative (31)P MRS in combination with ATP synthesis, pH, and T1 relaxation measurements may offer a promising tool to detect biochemical alterations at early stages of brain dysfunctions and diseases.

  7. Anthropomorphic 1H MRS head phantom.

    PubMed

    Rice, J R; Milbrandt, R H; Madsen, E L; Frank, G R; Boote, E J; Blechinger, J C

    1998-07-01

    An anthropomorphic 1H MRS head phantom has been developed which mimics the in vivo structure, metabolite concentrations, and relaxation times (for both water and metabolites) of human brain tissue. Different brain regions and two tumor types, fluid-containing ventricles, and air-filled sinus, and subcutaneous fat are all simulated. The main tissue-mimicking materials are gelatin/agar mixtures with metabolites and several other ingredients added. Their composition and method of production are thoroughly described. T1's and T2's of water in the phantom are very close to in vivo values, and metabolite T1's and T2's are considerably more realistic than those in aqueous solutions. Spectra and relaxation times for the pig brain were also acquired and compare well with those of the phantom. The realistic properties of this phantom should be useful for testing spectral quantitation and localization.

  8. (1)H and (31)P benchtop NMR of liquids and solids used in and/or produced during the manufacture of methamphetamine by the HI reduction of pseudoephedrine/ephedrine.

    PubMed

    Bogun, Ben; Moore, Sarah

    2017-09-01

    In this study, the use of benchtop NMR spectroscopy in the analysis of solids and liquids used and/or produced during the HI reduction of pseudoephedrine was evaluated. The study focused on identifying organic precursors and phosphorus containing compounds used in and/or produced during the manufacturing process. Samples taken from clandestine laboratories, where this synthesis process was suspected of occurring, were also analysed and evaluated. Benchtop NMR was able to distinguish between ephedrine, pseudoephedrine and methamphetamine as the free base and hydrochloride salt. This technique was also effective at identifying and distinguishing between phosphorus containing compounds used and/or produced during the manufacture of methamphetamine. Benchtop NMR was also determined to be effective at analysing samples from suspected clandestine laboratories. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Effects of sleep deprivation on sleep homeostasis and restoration during methadone-maintenance: a [31] P MRS brain imaging study

    PubMed Central

    Trksak, George H.; Jensen, J. Eric; Plante, David T.; Penetar, David M.; Tartarini, Wendy L.; Maywalt, Melissa A.; Brendel, Michael; Dorsey, Cynthia M.; Renshaw, Perry F.; Lukas, Scott E.

    2009-01-01

    SUMMARY Insomnia afflicts many individuals, but particularly those in chronic methadone treatment. Studies examining sleep deprivation (SD) have begun to identify sleep restoration processes involving brain bioenergetics. The technique [31]P magnetic resonance spectroscopy (MRS) can measure brain changes in the high-energy phosphates: alpha-, beta-, and gamma-nucleoside triphosphate (NTP). In the present study, 21 methadone-maintained (MM) and 16 control participants underwent baseline (BL), SD (40 wakeful hrs), recovery1 (RE1), and recovery2 (RE2) study nights. Polysomnographic sleep was recorded each night and [31]P MRS brain scanning conducted each morning using a 4T MR scanner (dual-tuned proton/phosphorus headcoil). Interestingly, increases in total sleep time (TST) and sleep efficiency index (SEI) commonly associated with RE sleep were not apparent in MM participants. Analysis of methadone treatment duration revealed that the lack of RE sleep increases in TST and SEI were primarily exhibited by short-term MM participants (methadone<12 months), while RE sleep in long-term MM (methadone>12 months) participants was more comparable to control participants. Slow wave sleep increased during RE1, but there was no difference between MM and control participants. Spectral power analysis revealed that compared to control participants; MM participants had greater delta, theta, and alpha spectral power during BL and RE sleep. [31]P MRS revealed that elevations in brain beta-NTP (a direct measure of ATP) following RE sleep were greater in MM compared to control participants. Results suggest that differences in sleep and brain chemistry during RE in MM participants may be reflective of a disruption in homeostatic sleep function. PMID:19775835

  10. Using 31P-NMR to investigate dynamics of soil phosphorus compounds in the Rothamsted Long Term Experiments

    NASA Astrophysics Data System (ADS)

    Blackwell, Martin; Turner, Ben; Granger, Steve; Hooper, Tony; Darch, Tegan; Hawkins, Jane; Yuan, Huimin; McGrath, Steve

    2015-04-01

    The technique of 31P-NMR spectroscopy has done more to advance the knowledge of phosphorus forms (especially organic phosphorus) in environmental samples than any other method. The technique has advanced such that specific compounds can be identified where previously only broad categories such as orthophosphate monoesters and diesters were distinguishable. The Soil Archive and Long Term Experiments at Rothamsted Research, UK, potentially provides an unequalled opportunity to use this technique to observe changes in soil phosphorus compounds with time and under different treatments, thereby enhancing our understanding of phosphorus cycling and use by plants. Some of the earliest work using this technique on soils was carried out by Hawkes et al. in 1984 and this used soils from two of the oldest Rothamsted Long Term Experiments, namely Highfield and Park Grass. Here we revisit the samples studied in this early work and reanalyse them using current methodology to demonstrate how the 31P-NMR technique has advanced. We also present results from a study on the phosphorus chemistry in soils along the Hoosfield acid strip (Rothamsted, UK), where a pH gradient from 3.7 to 7.8 occurs in a single soil with little variation in total phosphorus (mean ± standard deviation 399 ± 27 mg P kg-1). Soil pH was found to be an important factor in determining the proportion of phosphomonoesters and phosphodiesters in the soil organic phosphorus, although total organic phosphorus concentrations were a relatively consistent proportion of the total soil phosphorus (36 ± 2%) irrespective of soil pH. Key words. 31P-NMR, soil organic phosphorus, long term experiments, Hoosfield acid strip

  11. γ spectroscopy of states in Cl32 relevant for the S31(p,γ)Cl32 reaction rate

    DOE PAGES

    Afanasieva, L.; Blackmon, J. C.; Deibel, C. M.; ...

    2017-09-01

    Background: The 31S(p,gamma) 32Cl reaction becomes important for sulfur production in novae if the P-31(p, alpha)Si-28 reaction rate is somewhat greater than currently accepted. The rate of the S-31(p,gamma) Cl-32 reaction is uncertain, primarily due to the properties of resonances at E-c.m. = 156 and 549 keV. Purpose: We precisely determined the excitation energies of states in Cl-32 through high-resolution. spectroscopy including the two states most important for the S-31(p,gamma) Cl-32 reaction at nova temperatures. Method: Excited states in Cl-32 were populated using the B-10(Mg-24, 2n) Cl-32 reaction with a Mg-24 beam from the ATLAS facility at Argonne National Laboratory.more » The reaction channel of interest was selected using recoils in the Fragment Mass Analyzer, and we determined precise level energies by detecting. rays with Gammasphere. Results: We also observed. rays from the decay of six excited states in Cl-32. The excitation energies for two unbound levels at E-x = 1738.1 (6) keV and 2130.5 (10) keV were determined and found to be in agreement with a previous high-precision measurement of the S-32(He-3, t) Cl-32 reaction [1]. Conclusions: An updated 31S(p,gamma) Cl-32 reaction rate is presented. With the excitation energies of important levels firmly established, the dominant uncertainty in the reaction rate at nova temperatures is due to the strength of the resonance corresponding to the 2131-keV state in Cl-32.« less

  12. Quantitative ATP synthesis in human liver measured by localized 31P spectroscopy using the magnetization transfer experiment.

    PubMed

    Schmid, A I; Chmelík, M; Szendroedi, J; Krssák, M; Brehm, A; Moser, E; Roden, M

    2008-06-01

    The liver plays a central role in intermediate metabolism. Accumulation of liver fat (steatosis) predisposes to various liver diseases. Steatosis and abnormal muscle energy metabolism are found in insulin-resistant and type-2 diabetic states. To examine hepatic energy metabolism, we measured hepatocellular lipid content, using proton MRS, and rates of hepatic ATP synthesis in vivo, using the 31P magnetization transfer experiment. A suitable localization scheme was developed and applied to the measurements of longitudinal relaxation times (T1) in six healthy volunteers and the ATP-synthesis experiment in nine healthy volunteers. Liver 31P spectra were modelled and quantified successfully using a time domain fit and the AMARES (advanced method for accurate, robust and efficient spectral fitting of MRS data with use of prior knowledge) algorithm describing the essential components of the dataset. The measured T1 relaxation times are comparable to values reported previously at lower field strengths. All nine subjects in whom saturation transfer was measured had low hepatocellular lipid content (1.5 +/- 0.2% MR signal; mean +/- SEM). The exchange rate constant (k) obtained was 0.30 +/- 0.02 s(-1), and the rate of ATP synthesis was 29.5 +/- 1.8 mM/min. The measured rate of ATP synthesis is about three times higher than in human skeletal muscle and human visual cortex, but only about half of that measured in perfused rat liver. In conclusion, 31P MRS at 3 T provides sufficient sensitivity to detect magnetization transfer effects and can therefore be used to assess ATP synthesis in human liver.

  13. sup 31 P and sup 2 H NMR studies of structure and motion in bilayers of phosphatidylcholine and phosphatidylethanolamine

    SciTech Connect

    Ghosh, R. )

    1988-10-04

    The structural and motional properties of mixed bilayers of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) have been examined by using wide-line {sup 31}P, {sup 14}N, and {sup 2H} NMR. {sup 2}H and {sup 14}N NMR data showed that in mixed bilayers containing both PC and PE the conformations of the head-group moieties are essentially identical with those observed for bilayers containing a single phospholipid species. Equimolar amounts of cholesterol induce also only a small change in head-group conformation. For all phospholipid mixtures studied, the {sup 31}P T{sub 1} relaxation was homogeneous over the whole powder spectrum and could be fitted to a single-exponential decay. The {sup 31}P vs temperature profiles were analyzed by a simple correlation model. The presence of equimolar amounts of PE containing either the same (POPE) or a different (Escherichia coli PE) fatty acid composition had essentially no effect on the rate of rotational diffusion of the phosphate groups, with the correlation time being found to be 0.68 ns at 20{degree}C. The presence of equimolar amounts of cholesterol decreased the correlation time to 0.65 ns, and also the activation energy was reduced to 22.6 kJ mol{sup {minus}1}. The authors interpret the decrease in activation energy as being due to the spacing effect of cholesterol which reduces the H-bonding interactions between head-groups, allowing them to rotate more freely. For all cases examined, the rotational diffusion of the phosphate moieties was slower than that observed for the rigid glycerol backbone of the molecule, the latter probably corresponding to overall phospholipid rotation.

  14. Real-Time Analysis of Tenofovir Release Kinetics Using Quantitative Phosphorus ((31)P) Nuclear Magnetic Resonance Spectroscopy.

    PubMed

    Agrahari, Vivek; Meng, Jianing; Purohit, Sudhaunshu S; Oyler, Nathan A; Youan, Bi-Botti C

    2017-10-01

    The dialysis method is classically used for drug separation before analysis, but does not provide direct and real-time drug quantification and has limitations affecting the dialysis rate. In this study, a phosphorus nuclear magnetic resonance ((31)P-qNMR) method is developed for the real-time quantification of therapeutic molecules in vitro. The release kinetics of model drug, tenofovir (anti-HIV microbicide), was analyzed in vaginal fluid simulant (VFS), seminal fluid simulant (SFS), and human plasma (HP) from chitosan nanofibers (size ∼100-200 nm) using the NMR (direct) method and compared with dialysis/UV-Vis (indirect) method. The assay was linear in VFS/SFS (0.20-5.0 mM), HP (0.30-5.0 mM of drug concentration range) and specific no drug (31)P-qNMR chemical shift [∼15 ppm] interference with formulation/media components. Limit of detection values were 0.075/0.10/0.20 mM, whereas limit of quantification values were 0.20/0.20/0.30 mM in VFS/SFS/HP, respectively. The method was robust, precise (%RSE <2%), and accurate (%mean recovery 90%-110%). After 12 h, ∼77%/72%/70% wt/wt of tenofovir release was observed with direct, compared to ∼47%/52%/52% wt/wt by indirect method in VFS/SFS/HP, respectively. Approximately 20% decrease in %drug release observed with dialysis method suggested an interference with drug transport process due to the dialysis membrane and the Gibbs-Donnan effect. Overall, (31)P-qNMR provides more accurate, real-time, and direct drug quantification for effective in vitro-in vivo correlation. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  15. Detection of Phosphomonoester Signals in Proton-Decoupled 31P NMR Spectra of the Myocardium of Patients with Myocardial Hypertrophy

    NASA Astrophysics Data System (ADS)

    Jung, Wulf-Ingo; Sieverding, Ludger; Breuer, Johannes; Schmidt, Oliver; Widmaier, Stefan; Bunse, Michael; van Erckelens, Franz; Apitz, Jürgen; Dietze, Guenther J.; Lutz, Otto

    1998-07-01

    Proton-decoupled31P NMR spectroscopy at 1.5 T of the anterior left ventricular myocardium was used to monitor myocardial phosphate metabolism in asymptomatic patients with hypertrophic cardiomyopathy (HCM,n= 14) and aortic stenosis (AS,n= 12). In addition to the well-known phosphorus signals a phosphomonoester (PME) signal was detected at about 6.9 ppm in 7 HCM and 2 AS patients. This signal was not observed in the spectra of normal controls (n= 11). We suggest that in spectra of patients with myocardial hypertrophy the presence of a PME signal reflects alterations in myocardial glucose metabolism.

  16. Morphology, 31P Spin Diffusion, and Phase Transitions in a Representative Semicrystalline Polyphosphazene by Solid-State NMR

    DTIC Science & Technology

    1992-01-01

    NMR 12. PERSONAL AUTHOR(S) S. Taylor, J. White, N. Elbaum, R. Crosby, G. Gampbell, J. Haw and G. Hatfield 13a. TYPE OF REPORT 13b. TIMr y§;YPD 5/14 DATE...by block numoer) Solid-state NMR spectroscopy was used to investigate the morphology and molecular dynamics of poly[bis(3-methylphenoxy)phosphazene...PB3MP, a representative semicrystalline polyphospha-zene. Variable temperature 31p magic-angle spinning (MAS) NMR spectra revealed two well resolved

  17. Assessment of membrane protection by /sup 31/P-NMR effects of lidocaine on calcium-paradox in myocardium

    SciTech Connect

    Sakai, Hirosumi; Yoshiyama, Minoru; Teragaki, Masakazu; Takeuchi, Kazuhide; Takeda, Takeda; Ikata, Mari; Ishikawa, Makoto; Miura, Iwao

    1989-01-01

    In studying calcium paradox, perfused rat hearts were used to investigate the myocardial protective effects of lidocaine. Intracellular contents of phosphates were measured using the /sup 31/P-NMR method. In hearts reexposed to calcium, following 3 minute calcium-free perfusion, a rapid contracture occurred, followed by rapid and complete disappearance of intracellular phosphates with no resumption of cardiac function. In hearts where lidocaine was administered from the onset of the calcium-free perfusion until 2 minutes following the onset of reexposure to calcium, both intracellular phosphates and cardiac contractility were maintained. Therefore, it can be said that cell membranes were protected by lidocaine.

  18. Phytate degradation by lactic acid bacteria and yeasts during the wholemeal dough fermentation: a 31P NMR study.

    PubMed

    Reale, Anna; Mannina, Luisa; Tremonte, Patrizio; Sobolev, Anatoli P; Succi, Mariantonietta; Sorrentino, Elena; Coppola, Raffaele

    2004-10-06

    myo-Inositol hexaphosphate (IP6) is the main source of phosphorus in cereal grains, and therefore, in bakery products. Different microorganisms such as yeasts and lactic acid bacteria have phytase enzymes able to hydrolyze IP6 during the wholemeal breadmaking. In this paper, the phytase activity of Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus curvatus, and Saccharomyces cerevisiae strains, isolated from southern Italian sourdoughs, is assayed using the (31)P NMR technique. The sourdough technology based on the use of lactic acid bacteria in the breadmaking is finally suggested.

  19. Influence of surfactants and humic acids on Artemia Franciscana's embryonic phospho-metabolite profile as measured by (31)P NMR.

    PubMed

    Deese, Rachel D; Weldeghiorghis, Thomas K; Haywood, Benjamin J; Cook, Robert L

    2017-05-01

    Surfactants, such as triton X-100 (Tx-100), cetylpyridinium chloride (CPC), and sodium dodecyl sulfate (SDS) are known to be toxic to Artemia Franciscana (Artemia) - an organism, frequently used to monitor the health of the aquatic environment. The phospho-metabolite profile of a living organism is often indicative of imbalances that may have been caused by environmental stressors, such as surfactants. This study utilizes in vivo(31)P NMR to monitor temporal changes in the phospho-metabolite profile of Artemia caused by Tx-100, CPC, and SDS and the ability of humic acid (HA) to mitigate the toxicity of these surfactants. It was found that, while Tx-100 does not have any effect on the phospho-metabolite profile, both CPC and SDS cause a complete retardation in growth of the phosphodiester (PDE) peak in the (31)P NMR spectrum, which is indicative of the inhibited cell replication. This growth inhibition was independently verified by the decreased guanosine triphosphate (GTP) concentration in the CPC and SDS-exposed Artemia. In addition, upon introduction of HA to the CPC and SDS-exposed Artemia, an increase of PDE peak over time is indicative of HA mitigating toxicity. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Solid state {sup 31}P NMR study of phosphonate binding sites in guanidine-functionalized, molecular imprinted silica xerogels

    SciTech Connect

    Sasaki, D.Y.; Alam, T.D.

    2000-01-03

    Phosphonate binding sites in guanidine and ammonium surface-functionalized silica xerogels were prepared via the molecular imprinting technique and characterized using solid state {sup 31}P MAS NMR. One-point, two-point, and non-specific host-guest interactions between phenylphosphonic acid (PPA) and the functionalized gels were distinguished by characteristic chemical shifts of the observed absorption peaks. Using solid state as well as solution phase NMR analyses, absorptions observed at 15.5 ppm and 6.5 ppm were identified as resulting from the 1:1 (one-point) and 2:1 (two-point) guanidine to phosphonate interactions, respectively. Similar absorptions were observed with the ammonium functionalized gels. By examining the host-guest interactions within the gels, the efficiency of the molecular imprinting procedure with regard to the functional monomer-to-template interaction could be readily assessed. Template removal followed by substrate adsorption studies conducted on the guanidine functionalized gels provided a method to evaluate the binding characteristics of the receptor sites to a phosphonate substrate. During these experiments, {sup 29}Si and {sup 31}P MAS NMR acted as diagnostic monitors to identify structural changes occurring in the gel matrix and at the receptor site from solvent mediated processes.

  1. 31P electron-nuclear double resonance of the PIn antisite in InP:Zn detected via luminescence

    NASA Astrophysics Data System (ADS)

    Crookham, H. C.; Kennedy, T. A.; Treacy, D. J.

    1992-07-01

    Optically detected electron-nuclear double resonance (ODENDOR) has been observed via photoluminescence from the first-neighbor 31P shell of the phosphorus antisite in zinc-doped InP. Analysis of the ENDOR data confirms a tetrahedral arrangement of 31P nuclei. The hyperfine interaction for each of these nuclei is axial with ||A∥||/h=368.0+/-0.5 MHz and ||A⊥||/h=247.8+/-0.5 MHz. These parameters are slightly different from those reported by Jeon et al. [Phys. Rev. B 36, 1324 (1987)]. A shift of the ENDOR frequencies correlated with a change in the central nuclear-spin state has also been observed. We have been able to account for this shift with a perturbation treatment in which the electronic spin and central nuclear spin are treated exactly and a neighboring nuclear spin provides the perturbation. The best ENDOR signals are obtained with low optical-excitation-power density (~0.1 W/cm2) and low microwave modulation frequency (17 Hz). These conditions emphasize the contributions to the optically detected magnetic-resonance signal from distant donor-acceptor pairs.

  2. In vivo 31P-NMR studies of age and energy metabolism in an animal flap model.

    PubMed

    Schweizer, M P; Sylvester, J; Chick, L R; Tang, P P

    1995-08-01

    Changes in phosphate energy metabolism with time in a rat flap model were followed noninvasively with in vivo 31P-NMR. The influence of age on high-energy phosphate metabolites in perfused and ischemic ends of 3 x 10 cm dorsal flaps was noted from 30 minutes to 7 days after closure in 6-, 12-, and 24-month-old (n = 4, 7, and 8, respectively) male Fischer 344 rats. Phosphocreatine to inorganic phosphate ratios showed younger animals exhibiting significant returns to preinjury energy status in 2- and 3-mm ischemic layers. This behavior, 24 to 72 hours after closure, coincides with neovascularization of the flap tissue. By contrast, 12- and 24-month-old animals experienced statistically significantly lesser high-energy rebound, developing greater necrosis in the ischemic regions. Early intracellular pH lowering, indicative of lactate production, was somewhat greater in the flaps of younger animals. The in vivo 31P-NMR methods thus provide metabolic insights into flap behavior correlating with physiologic influences of aging.

  3. Defective mitochondrial function in vivo in skeletal muscle in adults with Down's syndrome: a 31P-MRS study.

    PubMed

    Phillips, Alexander C; Sleigh, Alison; McAllister, Catherine J; Brage, Soren; Carpenter, T Adrian; Kemp, Graham J; Holland, Anthony J

    2013-01-01

    Down's syndrome (DS) is a developmental disorder associated with intellectual disability (ID). We have previously shown that people with DS engage in very low levels of exercise compared to people with ID not due to DS. Many aspects of the DS phenotype, such as dementia, low activity levels and poor muscle tone, are shared with disorders of mitochondrial origin, and mitochondrial dysfunction has been demonstrated in cultured DS tissue. We undertook a phosphorus magnetic resonance spectroscopy ((31)P-MRS) study in the quadriceps muscle of 14 people with DS and 11 non-DS ID controls to investigate the post-exercise resynthesis kinetics of phosphocreatine (PCr), which relies on mitochondrial respiratory function and yields a measure of muscle mitochondrial function in vivo. We found that the PCr recovery rate constant was significantly decreased in adults with DS compared to non-DS ID controls (1.7 ± 0.1 min(-1) vs 2.1 ± 0.1 min(-1) respectively) who were matched for physical activity levels, indicating that muscle mitochondrial function in vivo is impaired in DS. This is the first study to investigate mitochondrial function in vivo in DS using (31)P-MRS. Our study is consistent with previous in vitro studies, supporting a theory of a global mitochondrial defect in DS.

  4. Solid state 31P cross-polarization/magic angle sample spinning nuclear magnetic resonance studies of crystalline glycogen phosphorylase b

    PubMed Central

    Taguchi, Jocelyn E.; Heyes, Stephen J.; Barford, David; Johnson, Louise N.; Dobson, Christopher M.

    1993-01-01

    31P cross-polarization/magic angle sample spinning nuclear magnetic resonance spectra have been obtained for pyridoxal 5′-phosphate (PLP) bound to glycogen phosphorylase b (GPb) in two different crystalline forms, monoclinic and tetragonal. Analysis of the intensities of the spinning sidebands in the nuclear magnetic resonance spectra has enabled estimates of the principal values of the 31P chemical shift tensors to be obtained. Differences between the two sets of values suggest differences in the environment of the phosphate moiety of the pyridoxal phosphate in the two crystalline forms. The tensor for the tetragonal crystalline form, T state GPb, is fully consistent with those found for dianionic phosphate groups in model compounds. The spectrum for the monoclinic crystalline form, R state GPb, although closer to that of dianionic than monoanionic model phosphate compounds, deviates significantly from that expected for a simple dianion or monoanion. This is likely to result from specific interactions between the PLP phosphate group and residues in its binding site in the protein. A possible explanation for the spectrum of the monoclinic crystals is that the shift tensor is averaged by a proton exchange process between different ionization states of the PLP associated with the presence of a sulfate ion bound in the vicinity of the PLP. PMID:8457673

  5. 2D {sup 31}P solid state NMR spectroscopy, electronic structure and thermochemistry of PbP{sub 7}

    SciTech Connect

    Benndorf, Christopher; Hohmann, Andrea; Schmidt, Peer; Eckert, Hellmut; Johrendt, Dirk; and others

    2016-03-15

    Phase pure polycrystalline PbP{sub 7} was prepared from the elements via a lead flux. Crystalline pieces with edge-lengths up to 1 mm were obtained. The assignment of the previously published {sup 31}P solid state NMR spectrum to the seven distinct crystallographic sites was accomplished by radio-frequency driven dipolar recoupling (RFDR) experiments. As commonly found in other solid polyphosphides there is no obvious correlation between the {sup 31}P chemical shift and structural parameters. PbP{sub 7} decomposes incongruently under release of phosphorus forming liquid lead as remainder. The thermal decomposition starts at T>550 K with a vapor pressure almost similar to that of red phosphorus. Electronic structure calculations reveal PbP{sub 7} as a semiconductor according to the Zintl description and clearly shows the stereo-active Pb-6s{sup 2} lone pairs in the electron localization function ELF. - Graphical abstract: Coordination of the lead atoms in PbP{sub 7}.

  6. Analysis of the bond-valence method for calculating (29) Si and (31) P magnetic shielding in covalent network solids.

    PubMed

    Holmes, Sean T; Alkan, Fahri; Iuliucci, Robbie J; Mueller, Karl T; Dybowski, Cecil

    2016-07-05

    (29) Si and (31) P magnetic-shielding tensors in covalent network solids have been evaluated using periodic and cluster-based calculations. The cluster-based computational methodology employs pseudoatoms to reduce the net charge (resulting from missing co-ordination on the terminal atoms) through valence modification of terminal atoms using bond-valence theory (VMTA/BV). The magnetic-shielding tensors computed with the VMTA/BV method are compared to magnetic-shielding tensors determined with the periodic GIPAW approach. The cluster-based all-electron calculations agree with experiment better than the GIPAW calculations, particularly for predicting absolute magnetic shielding and for predicting chemical shifts. The performance of the DFT functionals CA-PZ, PW91, PBE, rPBE, PBEsol, WC, and PBE0 are assessed for the prediction of (29) Si and (31) P magnetic-shielding constants. Calculations using the hybrid functional PBE0, in combination with the VMTA/BV approach, result in excellent agreement with experiment. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  7. Growth studies of subcutaneous rat tumours: comparison of 31P-NMR spectroscopy, acid extracts and histology.

    PubMed

    Stubbs, M; Rodrigues, L M; Griffiths, J R

    1989-11-01

    31P-NMP, surface coil spectra of three subcutaneously implanted rat tumours (Morris hepatoma 7777, GH3 prolactinoma, Walker carcinosarcoma) and an N-methyl-N-nitrosourea induced rat mammary adenocarcinoma at different stages of growth were obtained and compared with histological sections taken immediately after NMR acquisitions. Metabolite ratios (phosphocreatine (PCr)/beta nucleoside triphosphate (beta NTP), PCr/Pi, beta NTP/Pi) calculated from the NMR spectra were compared with ratios obtained from acid extracts of tumours of similar size. Measurements of creatine and ADP were also made. Three of the tumours showed positive correlations between increasing tumour size and decreasing metabolite ratios measured both by NMR and in extracts, whereas the Walker carcinosarcoma showed no correlation between size and any parameters measured. Phosphorus metabolite ratios, measured in extracts of skin overlying the tumours, indicated a fall in high energy phosphate when there was histological evidence of skin invasion by the tumour. Surface coil 31P-NMR spectra of subcutaneously grown or induced tumours in the rat represent a slowly changing steady state as the tumour increases in size. We conclude that increasing numbers of hypoxic tumour cells, rather than large areas of necrotic tissue, contribute largely to the NMR spectrum.

  8. Magic-angle-spinning 31P NMR spectra of solid dihydrogen phosphates. Comparison of ordered and dynamically disordered compounds.

    PubMed

    Lagier, C M; Olivieri, A C; Apperley, D C; Harris, R K

    1992-11-01

    High-resolution 31P NMR spectra are reported for several dihydrogen phosphates in the solid state. Shielding tensor components were retrieved by analysis of the sideband intensities. The results, together with previously published data, can be grouped according to the presence and type of proton exchange occurring in the crystals. Static MH2PO4 samples (M = Na, Li) show a shielding anisotropy delta sigma of approximately 120 ppm. In the case of M = Cs (one static P-OH bond and two oxygens attached to "half" hydrogens on the average) delta sigma is smaller (approximately 75 ppm) and can be understood in terms of the accepted, proton-exchange model. For highly disordered samples (M = K, NH4, Rb), where all four oxygens have nearby hydrogens with 50% occupancy, delta sigma is even smaller (approximately 30 ppm) but not zero. In the last-mentioned cases, 31P NMR information suggests that local PO4 environments may not have the symmetry that could be expected on the basis of the known crystal structures.

  9. /sup 31/P NMR analysis of membrane phospholipid organization in viable, reversibly electropermeabilized Chinese hamster ovary cells

    SciTech Connect

    Lopez, A.; Rols, M.P.; Teissie, J.

    1988-02-23

    Chinese hamster ovary (CHO) cells were reversibly permeabilized by submitting them to short, high-intensity, square wave pulses (1.8 kV/cm, 100 ..mu..s). The cells remained in a permeable state without loss of viability for several hours at 4/sup 0/C. A new anisotropic peak with respect to control cells was observed on /sup 31/P NMR spectroscopic analysis of the phospholipid components. This peak is only present when the cells are permeable, and normal anisotropy is recovered after resealing. Taking into account the fusogenicity of electropermeabilized cells, comparative studies were performed on 5% poly(ethylene glycol) treated cells. The /sup 31/P NMR spectra of the phospholipids displayed the same anisotropic peak as in the case of the electropermeabilized cells. In the two cases, this anisotropic peak was located downfield from the main peak associated to the phospholipids when organized in bilayers. The localization of this anisotropic peak is very different from the one of a hexagonal phase. The authors proposed a reorganization of the polar head group region leading to a weakening of the hydration layer to account for these observations. This was also thought to explain the electric field induced fusogenicity of these cells.

  10. Evaluation of [sup 31]P magnetic resonance spectroscopy localization techniques in human myocardium and soft-tissue sarcomas

    SciTech Connect

    Li, Chun-Wei.

    1993-01-01

    The overall goals of this thesis are to establish and evaluate [sup 31]P MR spectroscopy localization techniques for their application to the study of human myocardium and sarcomas. Several localization techniques which include 1D-CSI, ISIS, ISIS/CSI, and 2D-CSI were evaluated in the myocardial muscle of normal subjects and patients receiving 5-fluorouracil (5-FU) chemotherapy. Among these localization techniques, 2D-CSI is recommended since it shows good selectivity, good flexibility and a good compromise between sensitivity patient toleration limits. These localization techniques were also evaluated in patients with osteosarcoma and soft-tissue sarcomas. Among these localization techniques, 1D-CSI is recommended for big and superficial tumors. Further definition of the voxel is provided by using 2D-CSI or 3D-CSI in the case of small or deep seated tumors. Several techniques that should improve the [sup 31]P MR spectroscopic study of patients in the future are evaluated on the phantom. These include the presaturation of the chest wall muscle for improved myocardial spectral using the CSI sequence, implementation of the BIR-4 pulse for variable angle adjustable pulse, and the proton decoupling technique for improved resolution and sensitivity. The good performance of the phantoms studies show that these techniques can be further extended to the normal subject and patient studies.

  11. Fluorescence anisotropy, FT-IR spectroscopy and 31-P NMR studies on the interaction of paclitaxel with lipid bilayers.

    PubMed

    Dhanikula, Anand Babu; Panchagnula, Ramesh

    2008-06-01

    To understand the bilayer interaction with paclitaxel, fluorescence polarization, Fourier transform infrared spectroscopy (FT-IR) and 31-phosphorus nuclear magnetic resonance (31P-NMR) studies were performed on paclitaxel bearing liposomes. Fluorescence anisotropy of three probes namely, 1,6-diphenyl-1,3,5-hexatriene (DPH), 12-(9-anthroyloxy) stearic acid (12AS) and 8-anilino-1-naphthalene sulfonate (ANS) were monitored as a function of paclitaxel concentration in the unsaturated bilayers. The incorporation of paclitaxel decreased anisotropy of 12AS and ANS probes, while slightly increased anisotropy of DPH. Paclitaxel has a fluidizing effect in the upper region of the bilayer whereas the hydrophobic core is slightly rigidized. FT-IR spectroscopy showed an increase in the asymmetric and symmetric methylene stretching frequencies, splitting of methylene scissoring band and broadening of carbonyl stretching mode. These studies collectively ascertained that paclitaxel mainly occupies the cooperativity region and interact with the interfacial region of unsaturated bilayers and induces fluidity in the headgroup region of bilayer. At higher loadings (>3 mol%), paclitaxel might gradually tend to accumulate at the interface and eventually partition out of bilayer as a result of solute exclusion phenomenon, resulting in crystallization; seed non-bilayer phases, as revealed by 31P-NMR, thereby destabilizing liposomal formulations. In general, any membrane component which has a rigidization effect will decrease, while that with a fluidizing effect will increase, with a bearing on headgroup interactions, partitioning of paclitaxel into bilayers and stability of the liposomes.

  12. Characterization of the testicular cell types present in the rat by in vivo 31P magnetic resonance spectroscopy

    SciTech Connect

    van der Grond, J.; Van Pelt, A.M.; van Echteld, C.J.; Dijkstra, G.; Grootegoed, J.A.; de Rooij, D.G.; Mali, W.P. )

    1991-07-01

    Testes of vitamin A-deficient Wistar rats before and after vitamin A replacement, of rats irradiated in utero, and of control rats were investigated by in vivo 31P magnetic resonance (MR) spectroscopy. The testicular phosphomonoester/ATP (PM/ATP) ratio ranged from 0.79 {plus minus} 0.05 for testes that contained only interstitial tissue and Sertoli cells to 1.64 {plus minus} 0.04 for testes in which spermatocytes were the most advanced cell types present. When new generations of spermatids entered the seminiferous epithelium, this ratio decreased. The testicular phosphodiester/ATP (PD/ATP) ratio amounted to 0.16 {plus minus} 0.06 for testes in which Sertoli cells, spermatogonia, or spermatocytes were the most advanced cell type present. When new generations of spermatids entered the seminiferous epithelium, the PD/ATP ratio rapidly increased and finally reached a value of 0.71 {plus minus} 0.06 for fully developed testes. Taken together, specific patterns of the PM/ATP ratio, the PD/ATP ratio, and pH were obtained that were correlated to the presence of spermatogonia, spermatocytes, round spermatids, and elongated spermatids or to the absence of spermatogenic cells. Hence, a good impression of the status of the seminiferous epithelium in the rat can be obtained by in vivo 31P MR spectroscopy.

  13. Relationship between /sup 31/P nuclear magnetic resonance spectra and pulmonary vasomotor tone in hypoxic pig lobes

    SciTech Connect

    Buescher, P.; Pillain, R.; Pearse, D.; Eichhorn, G.; Sylvester, J.

    1986-03-01

    To investigate the relationship between lung tissue energy state and vasomotor tone, the authors measured /sup 31/P NMR spectra during repeated exposures to hypoxia in 5 isolated degassed left lower lobes perfused with blood at a constant flow (500ml/min) and left atrial pressure (<0mmHg). Perfusate O/sub 2/ tension (PpO/sub 2/) was changed by varying the gas mixtures (40, 7, 0% O/sub 2/) flowing through a bubble oxygenator in the perfusion circuit. /sup 31/P spectra obtained after stabilization of pulmonary artery pressure (Ppa) at each PpO/sub 2/ revealed peaks for ATP, inorganic phosphate (Pi) phosphomono and diesters (PME and PDE). During 7% O/sub 2/, Ppa and ATP increased but Pi did not change suggesting that lung tissue energy state improved during hypoxic vasoconstriction. During 0% O/sub 2/, there was a reversible deterioration of energy state (high Pi, low ATP). Thus, it appears that lung tissue energy state and vasomotor tone were related, but the precise nature of the relationship remains to be determined.

  14. Inhibition mechanisms of Zn precipitation on aluminum oxide by glyphosate: a 31P NMR and Zn EXAFS study.

    PubMed

    Li, Wei; Wang, Yu-Jun; Zhu, Mengqiang; Fan, Ting-Ting; Zhou, Dong-Mei; Phillips, Brian L; Sparks, Donald L

    2013-05-07

    In this research, the effects of glyphosate (GPS) on Zn sorption/precipitation on γ-alumina were investigated using a batch technique, Zn K-edge EXAFS, and (31)P NMR spectroscopy. The EXAFS analysis revealed that, in the absence of glyphosate, Zn adsorbed on the aluminum oxide surface mainly as bidentate mononuclear surface complexes at pH 5.5, whereas Zn-Al layered double hydroxide (LDH) precipitates formed at pH 8.0. In the presence of glyphosate, the EXAFS spectra of Zn sorption samples at pH 5.5 and 8.0 were very similar, both of which demonstrated that Zn did not directly bind to the mineral surface but bonded with the carboxyl group of glyphosate. Formation of γ-alumina-GPS-Zn ternary surface complexes was further suggested by (31)P solid state NMR data which indicated the glyphosate binds to γ-alumina via a phosphonate group, bridging the mineral surface and Zn. Additionally, we showed the sequence of additional glyphosate and Zn can influence the sorption mechanism. At pH 8, Zn-Al LDH precipitates formed if Zn was added first, and no precipitates formed if glyphosate was added first or simultaneously with Zn. In contrast, at pH 5.5, only γ-alumina-GPS-Zn ternary surface complexes formed regardless of whether glyphosate or Zn was added first or both were added simultaneously.

  15. Fructose-induced aberration of metabolism in familial gout identified by sup 31 P magnetic resonance spectroscopy

    SciTech Connect

    Seegmiller, J.E. Univ. of California, San Diego ); Dixon, R.M.; Kemp, G.J.; Rajagopalan, B.; Radda, G.K. ); Angus, P.W. Austin Hospital, Heidelburg, Victoria ); McAlindon, T.E.; Dieppe, P. )

    1990-11-01

    The hyperuricemia responsible for the development of gouty arthritis results from a wide range of environmental factors and underlying genetically determined aberrations of metabolism. {sup 31}P magnetic resonance spectroscopy studies of children with hereditary fructose intolerance revealed a readily detectable rise in phosphomonoesters with a marked fall in inorganic phosphate in their liver in vivo and a rise in serum urate in response to very low doses of oral fructose. Parents and some family members heterozygous for this enzyme deficiency showed a similar pattern when given a substantially larger dose of fructose. Three of the nine heterozygotes thus identified also had clinical gout, suggesting the possibility of this defect being a fairly common cause of gout. In the present study this same noninvasive technology was used to identify the same spectral pattern in 2 of the 11 families studied with hereditary gout. In one family, the index patient's three brothers and his mother all showed the fructose-induced abnormality of metabolism, in agreement with the maternal inheritance of metabolism, in agreement with the maternal inheritance of the gout in this family group. The test dose of fructose used produced a significantly larger increment in the concentration of serum urate in the patients showing the changes in {sup 31}P magnetic resonance spectra than in the other patients with familial gout or in nonaffected members, thus suggesting a simpler method for initial screening for the defect.

  16. Fast and simultaneous determination of (1) H-(1) H and (1) H-(19) F scalar couplings in complex spin systems: Application of PSYCHE homonuclear broadband decoupling.

    PubMed

    Kakita, Veera Mohana Rao; Rachineni, Kavitha; Hosur, Ramakrishna V

    2017-07-21

    The present manuscript focuses on fast and simultaneous determination of (1) H-(1) H and (1) H-(19) F scalar couplings in fluorinated complex steroid molecules. Incorporation of broadband PSYCHE homonuclear decoupling in the indirect dimension of zero-quantum filtered diagonal experiments (F1-PSYCHE-DIAG) suppresses (1) H-(1) H scalar couplings; however, it retains (1) H-(19) F scalar couplings (along F1 dimension) for the (19) F coupled protons while preserving the pure-shift nature for (1) H resonances uncoupled to (19) F. In such cases, along the direct dimensions, (1) H-(1) H scalar coupling multiplets deconvolute and they appear as duplicated multiplets for the (19) F coupled protons, which facilitates unambiguous discrimination of (19) F coupled (1) H chemical sites from the others. Further, as an added advantage, data acquisition has been accelerated by invoking the known ideas of spectral aliasing in the F1-PSYCHE-DIAG scheme and experiments demand only ~10 min of spectrometer times. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Crystalline 1H-1,2,3-triazol-5-ylidenes

    SciTech Connect

    Bertrand, Guy; Gulsado-Barrios, Gregorio; Bouffard, Jean; Donnadieu, Bruno

    2016-08-02

    The present invention provides novel and stable crystalline 1H-1,2,3 triazolium carbenes and metal complexes of 1H-1,2,3 triazolium carbenes. The present invention also provides methods of making 1H-1,2,3 triazolium carbenes and metal complexes of 1H-1,2,3 triazolium carbenes. The present invention also provides methods of using 1H-1,2,3 triazolium carbenes and metal complexes of 1H-1,2,3 triazolium carbenes in catalytic reactions.

  18. An (1)H-MRS evaluation of the phosphocreatine/creatine pool (tCr) in human muscle.

    PubMed

    Trump, M E; Hanstock, C C; Allen, P S; Gheorghiu, D; Hochachka, P W

    2001-03-01

    The human gastrocnemius was examined with and without creatine supplementation under the conditions of rest, ischemic fatigue (IF), and recovery to perturb the pool sizes and equilibrium between phosphocreatine (PCr) and creatine (Cr). (1)H- and (31)P-magnetic resonance spectroscopy (MRS) were used to examine the total creatine (tCr) pool in each of the metabolic states. (31)P-MRS monitored the depletion of the PCr peak during IF to <5% of that at rest. (1)H-MRS focused on the tCr methyl peak at 3.02 ppm (dipolar coupled triplet), at which point it was expected that the triplet peak intensity would be similar both in IF and rest. Initial (1)H-MRS data showed the peak intensity during IF decreased, suggesting a change in tCr pool size. Subsequent studies of transverse relaxation time (T(2)) revealed that this decline was primarily due to a more rapid T(2) decay of the tCr peak in IF (T(2) approximately 40 ms) compared with at rest (T(2) approximately 162 ms). Because Cr is the major contributor to tCr in IF, it is possible that there is a pool of Cr displaying reduced mobility in vivo. Moreover, the residual dipolar coupled triplet observed at rest collapsed into a broad singlet during IF, suggestive of significant changes in the ordered environment experienced at rest for PCr compared with when it is converted to Cr during IF. In addition, these data suggest that in (1)H-MRS studies whose goals include quantitative estimates of tCr pool sizes, standardized metabolic conditions or careful T(2) evaluations will be required.

  19. Brain and muscle energy metabolism studied in vivo by 31P-magnetic resonance spectroscopy in NARP syndrome.

    PubMed Central

    Lodi, R; Montagna, P; Iotti, S; Zaniol, P; Barboni, P; Puddu, P; Barbiroli, B

    1994-01-01

    Phosphorus magnetic resonance spectroscopy (31P-MRS) was used to study in vivo the energy metabolism of brain and skeletal muscle in two members of an Italian pedigree with NARP syndrome due to a point mutation at bp 8993 of mtDNA. In the youngest patient, a 13 year old girl with retinitis pigmentosa, ataxia, and psychomotor retardation, there was an alteration of brain energy metabolism shown by a decreased phosphocreatine content, increased [ADP] and decreased phosphorylation potential. The energy metabolism of her skeletal muscle was also abnormal, as shown by resting higher inorganic phosphate and lower phosphocreatine concentrations than in normal subjects. Her mother, a 41 year old woman with minimal clinical involvement, showed a milder derangement of brain energy metabolism and normal skeletal muscle. Findings with MRS showed that this point mutation of mtDNA is responsible for a derangement of energy metabolism in skeletal muscle and even more so in the brain. PMID:7798979

  20. Small angle X-ray scattering and 31P NMR studies on the phase behavior of phospholipid bilayered mixed micelles

    NASA Astrophysics Data System (ADS)

    Bolze, Jörg; Fujisawa, Tetsuro; Nagao, Takashi; Norisada, Kazushi; Saitô, Hazime; Naito, Akira

    2000-10-01

    The phase behavior of lipid bilayered micelles (`bicelles') (dimyristoyl-phosphatidylcholine, DMPC/dihexanoyl-phosphatidyl-choline, DHPC 2.6/1) has been studied by small angle X-ray scattering and 31P NMR. Below 3% w/v the bilayers are arranged in tightly packed stacks. At intermediate concentrations single units are observed, whereas at 24% w/v and higher, weak stacking occurs again. The DMPC/DHPC ratio in the bicelles strongly increases at low concentration, which is correlated with an increase in the bicelle size and stacking. The increase of the order parameter in a magnetic field is related to the stack formation. Below 297 K there is no stacking at any concentration and no magnetic alignment.

  1. 31P MAS NMR: a useful tool for the evaluation of VX natural weathering in various urban matrixes.

    PubMed

    Mizrahi, Dana M; Columbus, Ishay

    2005-11-15

    The fate of chemical warfare agent VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate) in various urban matrixes was monitored utilizing 31P MAS NMR. Chosen matrixes represent buildings, roads, pavement, and earth found in urban environments. In view of the high toxicity of VX, solid state NMR afforded a fairly safe experimental mode, omitting any chance for evaporation. Moreover, due to the nondestructive nature of these experiments, measurements could be repeated over and over using the same samples. Degradation rates of VX were obtained and compared to provide a list of relative reactivity toward VX: concrete > desert sand > beach sand > asphalt approximately to bitumen sheet. Chemical interactions between VX, its degradation products, and the matrixes were often expressed by widening of the peaks to the extent that mass balance could not be achieved. It is noteworthy that these experiments were usually carried out on crushed or milled specimens, allowing high reactivity and rapid reactions.

  2. A comparison of in vivo and in vitro 31P NMR spectra from human breast tumours: variations in phospholipid metabolism.

    PubMed Central

    Smith, T. A.; Glaholm, J.; Leach, M. O.; Machin, L.; Collins, D. J.; Payne, G. S.; McCready, V. R.

    1991-01-01

    An in vivo 31P NMR spectrum was obtained from each of four human breast tumours. The phosphomonoester and phosphodiester region of each spectrum consisted of a broad peak. Chemical extracts from samples of each of the tumours obtained at resection were examined on a high field strength NMR system. The phosphomonoester region in the spectrum from each extract resolved into three peaks consisting of phosphocholine, phosphoethanolamine and a nucleoside monophosphate. The phosphodiester region resolved into two components, glycerophosphorylcholine and glycerophosphorylethanolamine. Comparing the in vivo and in vitro data from each tumour showed that the contribution of phosphodiester was much lower in the in vitro spectra. We believe this to be a consequence of phospholipid, which would not appear in the aqueous extract, contributing to the phosphodiester peak in vivo. PMID:2021535

  3. Effects of aluminum treatment on phosphorus, carbon, and nitrogen distribution in lake sediment: a 31P NMR study.

    PubMed

    Reitzel, Kasper; Ahlgren, Joakim; Gogoll, Adolf; Rydin, Emil

    2006-02-01

    The effects of aluminum (Al) treatment on sediment composition of carbon (C), nitrogen (N) and phosphorus (P) were investigated in sediment representing pre- and post-treatment years in the Danish Lake Sønderby. 31P NMR spectroscopy analysis of EDTA-NaOH extracts revealed six functional P groups. Direct effects of the Al treatment were reflected in the orthophosphate profile revealing increased amounts of Al-P in the sediment layers representing the post-treatment period, as well as changes in organic P groups due to precipitation of phytoplankton and bacteria at the time of Al addition. Furthermore, changes in phytoplankton community structure and lowered production due to the Al treatment resulted in decreased concentrations of sediment organic P groups and total C. Exponential regressions were used to describe the diagenesis of C, N, and P in the sediment. From these regressions, half-life degradation times and C, N, and P burial rates were determined.

  4. In vivo (31)P magnetic resonance spectroscopy of the human liver at 7 T: an initial experience.

    PubMed

    Chmelik, Marek; Považan, Michal; Krššák, Martin; Gruber, Stephan; Tkačov, Martin; Trattnig, Siegfried; Bogner, Wolfgang

    2014-04-01

    Phosphorus ((31) P) MRS is a powerful tool for the non-invasive investigation of human liver metabolism. Four in vivo (31) P localization approaches (single voxel image selected in vivo spectroscopy (3D-ISIS), slab selective 1D-ISIS, 2D chemical shift imaging (CSI), and 3D-CSI) with different voxel volumes and acquisition times were demonstrated in nine healthy volunteers. Localization techniques provided comparable signal-to-noise ratios normalized for voxel volume and acquisition time differences, Cramer-Rao lower bounds (8.7 ± 3.3%1D-ISIS , 7.6 ± 2.5%3D-ISIS , 8.6 ± 4.2%2D-CSI , 10.3 ± 2.7%3D-CSI ), and linewidths (50 ± 24 Hz1D-ISIS , 34 ± 10 Hz3D-ISIS , 33 ± 10 Hz2D-CSI , 34 ± 11 Hz3D-CSI ). Longitudinal (T1 ) relaxation times of human liver metabolites at 7 T were assessed by 1D-ISIS inversion recovery in the same volunteers (n = 9). T1 relaxation times of hepatic (31) P metabolites at 7 T were the following: phosphorylethanolamine - 4.41 ± 1.55 s; phosphorylcholine - 3.74 ± 1.31 s; inorganic phosphate - 0.70 ± 0.33 s; glycerol 3-phosphorylethanolamine - 6.19 ± 0.91 s; glycerol 3-phosphorylcholine - 5.94 ± 0.73 s; γ-adenosine triphosphate (ATP) - 0.50 ± 0.08 s; α-ATP - 0.46 ± 0.07 s; β-ATP - 0.56 ± 0.07 s. The improved spectral resolution at 7 T enabled separation of resonances in the phosphomonoester and phosphodiester spectral region as well as nicotinamide adenine dinucleotide and uridine diphosphoglucose signals. An additional resonance at 2.06 ppm previously assigned to phosphoenolpyruvate or phosphatidylcholine is also detectable. These are the first (31) P metabolite relaxation time measurements at 7 T in human liver, and they will help in the exploration of new, exciting questions in metabolic research with 7 T MR. Copyright © 2014 John Wiley & Sons, Ltd.

  5. Measurement of intracellular pH of maize seeds (Zea mays) during germination by 31P nuclear magnetic resonance spectroscopy.

    PubMed

    Barba, I; Gasparovic, C; Cabañas, M E; Alonso, J; Murillo, I; San Segundo, B; Arús, C

    1997-07-01

    The 31P NMR spectra of germinating maize seeds showed a single broad resonance that shifted its position as germination proceeded (studied between 0 and 10 days). The resonance was shown to originate from the phosphate groups of phytine (Mg2+, Ca2+ and K+ salt of myoinositol hexakisphosphate) in a subcellular compartment of the embryo scutellar cells. A series of calibration curves for the chemical shift dependence of the phytate resonance in the presence of Mg2+ and Ca2+ were constructed. These calibration curves allowed us to determine that an acidification of the phytate containing compartment in the seed embryo takes place, reaching a minimum at about pH 4 after three days of germination. This acidification could be important in allowing phytate solubilization for export to growing parts of the maize seedling.

  6. Formation of Po isotopes in the reactions {sup 27}Al + {sup 175}Lu and {sup 31}P + {sup 169}Tm

    SciTech Connect

    Andreev, A.N.; Bogdanov, D.D.; Eremin, A.V.

    1995-05-01

    The excitation functions and the cross sections for the formation of {sup 192-198}Po isotopes in the reactions {sup 27}Al + {sup 175}Lu and {sup 31}P + {sup 169}Tm are measured. A comparison of the results obtained for these reactions with the data on the cross sections for the formation of Po isotopes in the reaction {sup 100}Mo + {sup 92-100}Mo leads to the conclusion that the characteristics of the evaporation channel do not depend on the mass of the bombarding ion up to the complete symmetry in the input channel. It is shown that the experimental data can be adequately described using the statistical approach to the deexcitation of a compound nucleus only under the assumption that the liquid-drop fission barrier is reduced significantly for neutron-deficient Po isotopes. 21 refs., 5 figs., 2 tabs.

  7. sup 31 P NMR measurements of the ADP concentration in yeast cells genetically modified to express creatine kinase

    SciTech Connect

    Brindle, K.; Braddock, P.; Fulton, S. )

    1990-04-03

    Rabbit muscle creatine kinase has been introduced into the yeast Saccharomyces cerevisiae by transforming cells with a multicopy plasmid containing the coding sequence for the enzyme under the control of the yeast phosphoglycerate kinase promoter. The transformed cells showed creating kinase activities similar to those found in mammalian heart muscle. {sup 31}P NMR measurements of the near-equilibrium concentrations of phosphocreatine and cellular pH together with measurements of the total extractable concentrations of phosphocreatine and creatine allowed calculation of the free ADP/ATP ratio in the cell. The calculated ratio of approximately 2 was considerably higher than the ratio of between 0.06 and 0.1 measured directly in cell extracts.

  8. NMR shielding constants in PH3, absolute shielding scale, and the nuclear magnetic moment of 31P.

    PubMed

    Lantto, Perttu; Jackowski, Karol; Makulski, Włodzimierz; Olejniczak, Małgorzata; Jaszuński, Michał

    2011-09-29

    Ab initio values of the absolute shielding constants of phosphorus and hydrogen in PH(3) were determined, and their accuracy is discussed. In particular, we analyzed the relativistic corrections to nuclear magnetic resonance (NMR) shielding constants, comparing the constants computed using the four-component Dirac-Hartree-Fock approach, the four-component density functional theory (DFT), and the Breit-Pauli perturbation theory (BPPT) with nonrelativistic Hartree-Fock or DFT reference functions. For the equilibrium geometry, we obtained σ(P) = 624.309 ppm and σ(H) = 29.761 ppm. Resonance frequencies of both nuclei were measured in gas-phase NMR experiments, and the results were extrapolated to zero density to provide the frequency ratio for an isolated PH(3) molecule. This ratio, together with the computed shielding constants, was used to determine a new value of the nuclear magnetic dipole moment of (31)P: μ(P) = 1.1309246(50) μ(N).

  9. Use of 31P nuclear magnetic resonance spectroscopy and electron microscopy to study phosphorus metabolism of microorganisms from wastewaters.

    PubMed

    Florentz, M; Granger, P; Hartemann, P

    1984-03-01

    We used 31P nuclear magentic resonance to study the transfer of phosphorus between Pis and polyphosphates in microorganisms involved in wastewater treatment. We showed that the transfer process is reversible and of the first order in accordance with the polyphosphate concentration. The presence of nitrates in the anoxic phase led to results similar to those obtained during the aerobic phase. (Anoxic implies absence of oxygen but presence of nitrate, whereas anaerobic implies absence of oxygen and nitrate. In bacteriology, the term anoxic is not common, and the term anaerobic implies absence of oxygen and includes the conditions under which nitrate is present.) We observed that carbon dioxide lowers the pH, which entails a hydrolysis of polyphosphates, and helium seems to stop the evolution of the cells. Further, 2,4-dinitrophenol decouples the oxidative phosphorylation and brings about a decrease in the polyphosphate pool.

  10. Distance measurements in disodium ATP hydrates by means of 31P double quantum two-dimensional solid-state NMR spectroscopy.

    PubMed

    Potrzebowski, M J; Gajda, J; Ciesielski, W; Montesinos, I M

    2006-04-01

    POST-C7 measurements provide constraints allowing distinguishing crystal lattice organization and establishing intra and/or intermolecular distances between phosphorus atoms of triphosphate chains for different hydrates of disodium ATP salts. Double-quantum efficiency in function of excitation time obtained from series of two-dimensional spectra for POST-C7 experiments was used to set up of buildup curves and semi-quantitative measure of 31P-31P length.

  11. Characterization of phosphorus forms in lake macrophytes and algae by solution (31)P nuclear magnetic resonance spectroscopy.

    PubMed

    Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Giesy, John P; He, Zhongqi; Song, Lirong; Fan, Mingle

    2016-04-01

    Debris from aquatic macrophytes and algae are important recycling sources of phosphorus (P), which can result in continuing blooms of algae by recycling bioavailable P in the eutrophic lakes. However, knowledge of forms of P in aquatic macrophytes and algae and their contribution to internal loads of P in lakes is limited. Without such knowledge, it is difficult to develop appropriate strategies to remediate and or restore aquatic ecosystems that have become eutrophic. Therefore, in this work, P was extracted from six types of aquatic macrophytes and algae collected from Tai Lake of China and characterized by use of solution (31)P-nuclear magnetic resonance (NMR) spectroscopy. When extracted by 0.5 M NaOH-25 mM EDTA, extraction recovery of total P(TP) and organic P(Po) exceeded 90 %. Concentrations of Po in algae and aquatic macrophytes were 5552 mg kg(-1) and 1005 mg kg(-1) and accounted for 56.0 and 47.2 % of TP, respectively. When Po, including condensed P, was characterized by solution (31)P-NMR Po in algae included orthophosphate monoesters (79.8 %), pyrophosphate (18.2 %), and orthophosphate diester (2.0 %), and Po in aquatic macrophytes included orthophosphate monoesters (90.3 %), pyrophosphate (4.2 %), and orthophosphate diester (5.5 %). Additionally, orthophosphate monoesters in algal debris mainly included β-glycerophosphate (44.1 %), α-glycerophosphate (13.5 %), and glucose 6-phosphate (13.5 %). Orthophosphate monoesters in aquatic macrophytes mainly included β-glycerophosphate (27.9 %), α-glycerophosphate (24.6 %), and adenosine 5' monophosphate (8.2 %). Results derived from this study will be useful in better understanding nutrient cycling, relevant eutrophication processes, and pollution control for freshwater lakes.

  12. Determination of neo- and d-chiro-Inositol Hexakisphosphate in Soils by Solution 31P NMR Spectroscopy

    PubMed Central

    2012-01-01

    The inositol phosphates are an abundant but poorly understood group of organic phosphorus compounds found widely in the environment. Four stereoisomers of inositol hexakisphosphate (IP6) occur, although for three of these (scyllo, neo, and d-chiro) the origins, dynamics, and biological function remain unknown, due in large part to analytical limitations in their measurement in environmental samples. We synthesized authentic neo- and d-chiro-IP6 and used them to identify signals from these compounds in three soils from the Falkland Islands. Both compounds resisted hypobromite oxidation and gave quantifiable 31P NMR signals at δ = 6.67 ppm (equatorial phosphate groups of the 4-equatorial/2-axial conformer of neo-IP6) and δ = 6.48 ppm (equatorial phosphate groups of the 2-equatorial/4-axial conformer of d-chiro-IP6) in soil extracts. Inositol hexakisphosphate accounted for 46–54% of the soil organic phosphorus, of which the four stereoisomers constituted, on average, 55.9% (myo), 32.8% (scyllo), 6.1% (neo), and 5.2% (d-chiro). Reappraisal of the literature based on the new signal assignments revealed that neo- and d-chiro-IP6 occur widely in both terrestrial and aquatic ecosystems. These results confirm that the inositol phosphates can constitute a considerable fraction of the organic phosphorus in soils and reveal the prevalence of neo- and d-chiro-IP6 in the environment. The hypobromite oxidation and solution 31P NMR spectroscopy procedure allows the simultaneous quantification of all four IP6 stereoisomers in environmental samples and provides a platform for research into the origins and ecological significance of these enigmatic compounds. PMID:22489788

  13. Analysis of 31P MAS NMR spectra and transversal relaxation of bacteriophage M13 and tobacco mosaic virus.

    PubMed Central

    Magusin, P C; Hemminga, M A

    1994-01-01

    Phosphorus magic angle spinning nuclear magnetic resonance (NMR) spectra and transversal relaxation of M13 and TMV are analyzed by use of a model, which includes both local backbone motions of the encapsulated nucleic acid molecules and overall rotational diffusion of the rod-shaped virions about their length axis. Backbone motions influence the sideband intensities by causing a fast restricted reorientation of the phosphodiesters. To evaluate their influence on the observed sideband patterns, we extend the model that we used previously to analyze nonspinning 31P NMR lineshapes (Magusin, P.C.M.M., and M. A. Hemminga. 1993a. Biophys. J. 64:1861-1868) to magic angle spinning NMR experiments. Backbone motions also influence the conformation of the phosphodiesters, causing conformational averaging of the isotropic chemical shift, which offers a possible explanation for the various linewidths of the centerband and the sidebands observed for M13 gels under various conditions. The change of the experimental lineshape of M13 as a function of temperature and hydration is interpreted in terms of fast restricted fluctuation of the dihedral angles between the POC and the OCH planes on both sides of the 31P nucleus in the nucleic acid backbone. Backbone motions also seem to be the main cause of transversal relaxation measured at spinning rates of 4 kHz or higher. At spinning rates less than 2 kHz, transversal relaxation is significantly faster. This effect is assigned to slow, overall rotation of the rod-shaped M13 phage about its length axis. Equations are derived to simulate the observed dependence of T2e on the spinning rate. PMID:8038391

  14. Direct Speciation of Phosphorus in Alum-Amended Poultry Litter: Solid-State 31P NMR Investigation

    SciTech Connect

    Hunger, Stefan; Cho, Herman M.; Sims, James T.; Sparks, Donald L.

    2004-02-01

    Amending poultry litter (PL) with aluminum sulfate (alum) has proven to be effective in reducing water-soluble phosphorus (P) in the litter and in runoff from fields that have received PL applications; it has therefore been suggested as a best management practice. Although its effectiveness has been demonstrated on a macroscopic scale in the field, little is known about P speciation in either alumamended or unamended litter. This knowledge is important for the evaluation of the long-term stability and bioavailability of P, which is a necessary prerequisite for the assessment of the sustainability of intensive poultry operations. Both solid state MAS and CP-MAS {sup 31}P NMR as well as {sup 31}P({sup 27}Al) TRAPDOR were used to investigate P speciation in alumamended and unamended PL. The results indicate the presence of a complex mixture of organic and inorganic orthophosphate phases. A calcium phosphate phase, probably a surface precipitate on calcium carbonate, could be identified in both unamended and alum-amended PL, as well as physically bound HPO{sub 4}{sup 2-}. Phosphate associated with Al was found in the alum-amended PL, most probably a mixture of a poorly ordered wavellite and phosphate surface complexes on aluminum hydroxide that had been formed by the hydrolysis of alum. However, a complex mixture of organic and inorganic phosphate species could not be resolved. Phosphate associated with Al comprised on average 40{+-}14% of the total P in alum-amended PL, whereas calcium phosphate phases comprised on average 7{+-}4% in the alum-amended PL and 14{+-}5% in the unamended PL.

  15. sup 31 P nuclear magnetic resonance study of the effect of azide on xylose fermentation by Candida tropicalis

    SciTech Connect

    Lohmeier-Vogel, E.; Vogel, H. ); Skoog, K.; Hahn-Haegerdal, B. )

    1989-08-01

    Maximal ethanol production by Candida tropicalis grown on xylose was obtained at an oxygen transfer rate of 5 to 7 mmol/liter per h. Addition of 0.2 mM azide increased the ethanol yield by a factor of 3 to 4, based on the cell mass produced, and decreased the formation of the by-product xylitol by 80%. In the presence of azide, ethanol was reassimilated before the carbon source was depleted. At all oxygenation levels studied, azide caused 25 to 60% of the carbon to be lost, most probable as carbon dioxide. Identical spectra were obtained with {sup 31}P nuclear magnetic resonance spectroscopy performed on extracts of C. tropicalis grown on xylose in the absence and presence of azide. Azide lowered the levels of sugar phosphates. Enzymatic analysis showed extremely low levels of fructose 1,6-diphosphate compared with the levels obtained in the absence of azide, while the level of malate, a citric acid cycle intermediate, was not influenced by azide. {sup 31}P nuclear magnetic resonance spectroscopy performed on xylose-grown whole cells of C. tropicalis showed that azide lowered the intracellular pH, inhibited the uptake of external P{sub i}, and decreased the buildup of polyphosphate in relation to results with untreated cells. Similar results were obtained with the uncoupler of oxidative phosphorylation carbonyl cyanide m-chlorophenylhydrazone (CCCP), except that CCCP treatment led to extremely high levels of internal P{sub i}. The dual effect of azide as a respiratory inhibitor and as an uncoupler is discussed with respect to the metabolism and product formation in xylose-assimilating C. tropicalis.

  16. Preservation of bilayer structure in human erythrocytes and erythrocyte ghosts after phospholipase treatment. A 31P-NMR study.

    PubMed

    van Meer, G; de Kruijff, B; op den Kamp, J A; van Deenen, L L

    1980-02-15

    1. Fresh human erythrocytes were treated with lytic and non-lytic combinations of phospholipases A2, C and sphingomyelinase. The 31P-NMR spectra of ghosts derived from such erythrocytes show that, in all cases, the residual phospholipids and lysophospholipids remain organized in a bilayer configuration. 2. A bilayer configuration of the (lyso)phospholipids was also observed after treatment of erythrocyte ghosts with various phospholipases even in the case that 98% of the phospholipid was converted into lysophospholipid (72%) and ceramides (26%). 3. A slightly decreased order of the phosphate group of phospholipid molecules, seen as reduced effective chemical shift anisotropy in the 31P-NMR spectra, was found following the formation of diacyglycerols and ceramides in the membrane of intact erythrocytes. Treatment of ghosts always resulted in an extensive decrease in the order of the phosphate groups. 4. The results allow the following conclusions to made: a. Hydrolysis of phospholipids in intact red cells and ghosts does not result in the formation of non-bilayer configuration of residual phospholipids and lysophospholipids. b. Haemolysis, which is obtained by subsequent treatment of intact cells with sphingomyelinase and phospholipase A2, or with phospholipase C, cannot be ascribed to the formation of non-bilayer configuration of phosphate-containing lipids. c. Preservation of bilayer structure, even after hydrolysis of all phospholipid, shows that other membrane constitutents, e.g. cholesterol and/or membrane proteins play an important role in stabilizing the structure of the erythrocyte membrane. d. A major prerequisite for the application of phospholipases in lipid localization studies, the preservation of a bilayer configuration during phospholipid hydrolysis, is met for the erythrocyte membrane.

  17. Some properties of the sum C1(h, k)

    NASA Astrophysics Data System (ADS)

    Cetin, Elif

    2017-07-01

    In [10], we have investigated properties of the sum C1(h, k). In this paper, we will give some other arithmetic properties of the sum C1(h, k). Moreover, in the light of the sum B1(h, k), which has also defined in [10], we will give specific values of the sum C1(h, k) when h + k is an odd number. Finally, we will give a relation between the sum C1(h, k) and the Hardy-Berndt sum s5(h, k) for a special case.

  18. Use of (77)Se and (125)Te NMR Spectroscopy to Probe Covalency of the Actinide-Chalcogen Bonding in [Th(En){N(SiMe3)2}3](-) (E = Se, Te; n = 1, 2) and Their Oxo-Uranium(VI) Congeners.

    PubMed

    Smiles, Danil E; Wu, Guang; Hrobárik, Peter; Hayton, Trevor W

    2016-01-27

    Reaction of [Th(I)(NR2)3] (R = SiMe3) (1) with 1 equiv of either [K(18-crown-6)]2[Se4] or [K(18-crown-6)]2[Te2] affords the thorium dichalcogenides, [K(18-crown-6)][Th(η(2)-E2)(NR2)3] (E = Se, 2; E = Te, 3), respectively. Removal of one chalcogen atom via reaction with Et3P, or Et3P and Hg, affords the monoselenide and monotelluride complexes of thorium, [K(18-crown-6)][Th(E)(NR2)3] (E = Se, 4; E = Te, 5), respectively. Both 4 and 5 were characterized by X-ray crystallography and were found to feature the shortest known Th-Se and Th-Te bond distances. The electronic structure and nature of the actinide-chalcogen bonds were investigated with (77)Se and (125)Te NMR spectroscopy accompanied by detailed quantum-chemical analysis. We also recorded the (77)Se NMR shift for a U(VI) oxo-selenido complex, [U(O)(Se)(NR2)3](-) (δ((77)Se) = 4905 ppm), which features the highest frequency (77)Se NMR shift yet reported, and expands the known (77)Se chemical shift range for diamagnetic substances from ∼3300 ppm to almost 6000 ppm. Both (77)Se and (125)Te NMR chemical shifts of given chalcogenide ligands were identified as quantitative measures of the An-E bond covalency within an isoelectronic series and supported significant 5f-orbital participation in actinide-ligand bonding for uranium(VI) complexes in contrast to those involving thorium(IV). Moreover, X-ray diffraction studies together with NMR spectroscopic data and density functional theory (DFT) calculations provide convincing evidence for the actinide-chalcogen multiple bonding in the title complexes. Larger An-E covalency is observed in the [U(O)(E)(NR2)3](-) series, which decreases as the chalcogen atom becomes heavier.

  19. Intracellular pH measured by (31) P-MR-spectroscopy might predict site of progression in recurrent glioblastoma under antiangiogenic therapy.

    PubMed

    Wenger, Katharina J; Hattingen, Elke; Franz, Kea; Steinbach, Joachim P; Bähr, Oliver; Pilatus, Ulrich

    2017-02-06

    In solid tumors, changes in the expression/activity of plasma membrane ion transporters facilitate proton efflux and enable tumor cells to maintain a higher intracellular pH (pHi ), while the microenvironment (pHe ) is commonly more acidic. This supports various tumor-promoting mechanisms. We propose that these changes in pH take place before a magnetic resonance imaging (MRI)-detectable brain tumor recurrence occurs. We enrolled 66 patients with recurrent glioblastoma, treated with bevacizumab. Patients received a baseline and 8-week follow-up MRI including (1) H/(31) P MRSI (spectroscopy) on a 3T clinical scanner, until progressive disease according to Response Assessment in Neuro-Oncology (RANO) criteria occurred. Fourteen patients showed a distant or diffuse tumor recurrence (subsequent tumor) during treatment and were therefore selected for further evaluation. At the site of the subsequent tumor, an area of interest for MRSI voxel selection was retrospectively defined on radiographically unaffected baseline MRI sequences. Before treatment, pHi in the area of interest (subsequent tumor) was significantly higher than pHi of the contralateral normal-appearing tissue (control; P < 0.001). It decreased at the time of best response (P = 0.06), followed by a significant increase at progression (P = 0.03; baseline mean: 7.06, median: 7.068, SD: 0.032; best response mean: 7.044, median: 7.036, SD: 0.025; progression mean: 7.08, median: 7.095, SD 0.035). Until progression, the subsequent tumor was not detectable on standard MRI sequences. The area of existing tumor responded similar, but changes were not significant (decrease P = 0.22; increase P = 0.28). Elevated pHi in radiographically unaffected tissue at baseline might precede MRI-detectable progression in patients with recurrent glioblastoma treated with bevacizumab. 2 J. Magn. Reson. Imaging 2017. © 2017 International Society for Magnetic Resonance in Medicine.

  20. Localized Spectroscopy from Anatomically Matched Compartments: Improved Sensitivity and Localization for Cardiac 31P MRS in Humans

    NASA Astrophysics Data System (ADS)

    Löffler, Ralf; Sauter, Rolf; Kolem, Heinrich; Haase, Axel; von Kienlin, Markus

    1998-10-01

    Several pioneering studies have demonstrated that localized31P NMR spectroscopy of the human heart might become an important diagnostic tool in cardiology. The main limitation is due to the low sensitivity of these experiments, allowing only crude spatial resolution. We have implemented a three-dimensional version of SLOOP ("spectral localization with optimal pointspread function") on a clinical instrument. SLOOP takes advantage of all availablea prioriinformation to match the size and the shape of the sensitive volumes to the anatomical structures in the examined subject. Thus, SLOOP reduces the contamination from adjacent organs and improves the sensitivity compared to conventional techniques such as ISIS or chemical shift imaging (CSI). Initial studies were performed on six healthy volunteers at 1.5 T. The good localization properties are demonstrated by the absence of resonances from blood in the heart spectra, and by PCr-free spectra from the liver. Compared to conventional CSI, the signal-to-noise ratio of the SLOOP heart spectra was improved by approximately 30%. Taking into account the varying excitation angle in the inhomogeneous B1field of the surface coil, the SLOOP model computes the local spin saturation at every point in space. Therefore, no global saturation correction is required in the quantitative evaluation of local spectra. In this study, we found a PCr/γ-ATP ratio in the left ventricular wall of 1.90 ± 0.33 (mean ± standard deviation).

  1. Quantitative 31P NMR analysis of solid wood offers an insight into the acetylation of its components.

    PubMed

    Sadeghifar, Hasan; Dickerson, James P; Argyropoulos, Dimitris S

    2014-11-26

    As a solid substrate, wood and its components are almost invariably examined via spectroscopic or indirect methods of analysis. Unlike earlier approaches, in this effort we dissolve pulverized wood in ionic liquid and then directly derive its functional group contents by quantitative (31)P NMR. As such, this novel analytical methodology is thoroughly examined and an insight into the detailed way acetylation proceeds on solid wood and its components is provided as a function of wood density and within its various anatomical features. As anticipated, the efficiency of acetylation was found to be greater within low density wood than in high density wood. The lignin, the cellulose and the hemicelluloses of the low density wood was found to be acetylated nearly twice as fast with remarkable differences in their quantitative degree of acetylation amongst them. This direct analytical data validates the applied methodology and confirms, for the first time, that the order of acetylation in solid wood is lignin>hemicellulose>cellulose and no reactivity differences exist between early wood and late wood.

  2. Skeletal muscle ATP synthesis and cellular H+ handling measured by localized 31P-MRS during exercise and recovery

    PubMed Central

    Fiedler, Georg B.; Schmid, Albrecht I.; Goluch, Sigrun; Schewzow, Kiril; Laistler, Elmar; Niess, Fabian; Unger, Ewald; Wolzt, Michael; Mirzahosseini, Arash; Kemp, Graham J.; Moser, Ewald; Meyerspeer, Martin

    2016-01-01

    31P magnetic resonance spectroscopy (MRS) is widely used for non-invasive investigation of muscle metabolism dynamics. This study aims to extend knowledge on parameters derived from these measurements in detail and comprehensiveness: proton (H+) efflux, buffer capacity and the contributions of glycolytic (L) and oxidative (Q) rates to ATP synthesis were calculated from the evolutions of phosphocreatine (PCr) and pH. Data are reported for two muscles in the human calf, for each subject and over a wide range of exercise intensities. 22 subjects performed plantar flexions in a 7T MR-scanner, leading to PCr changes ranging from barely noticeable to almost complete depletion, depending on exercise protocol and muscle studied by localized MRS. Cytosolic buffer capacity was quantified for the first time non-invasively and individually, as was proton efflux evolution in early recovery. Acidification started once PCr depletion reached 60–75%. Initial and end-exercise L correlated with end-exercise levels of PCr and approximately linear with pH. Q calculated directly from PCr and pH derivatives was plausible, requiring fewer assumptions than the commonly used ADP-model. In conclusion, the evolution of parameters describing cellular energy metabolism was measured over a wide range of exercise intensities, revealing a relatively complete picture of muscle metabolism. PMID:27562396

  3. Compartment syndrome: A quantitative study of high-energy phosphorus compounds using sup 31 P-magnetic resonance spectroscopy

    SciTech Connect

    Heppenstall, R.B.; Sapega, A.A.; Izant, T.; Fallon, R.; Shenton, D.; Park, Y.S.; Chance, B. )

    1989-08-01

    The purpose of this study was to quantitate the intracellular high-energy phosphate compounds during 6 hours of tissue ischemia in the anterior tibial compartment of beagles subjected to an induced traumatized compartment syndrome. The goal of this work was to provide clinicians with objective criteria to augment clinical judgment regarding surgical intervention in the impending compartment syndrome. A beagle model was utilized in which the Delta pressure (difference between the mean arterial pressure and compartment pressure) could be controlled. The model, in conjunction with {sup 31}P-magnetic resonance spectroscopy (MRS), allowed a measure of high-energy phosphate compounds and pH in the compartment at various Delta pressures. The extent of ischemic metabolic insult in the compartment was then quantitated. Our data suggest the following: (1) lower Delta pressures result in a proportionally greater drop in the intracellular phosphocreatine ratio and pH; (2) at lower Delta pressures, there is proportionally greater decline in the percentage recovery post-fasciotomy; (3) blood pressure is extremely important and periods of hypotension may result in increased muscle damage at lower compartment pressures.

  4. Modification of the 31P magnetic resonance spectra of a rat tumour using vasodilators and its relationship to hypotension.

    PubMed Central

    Tozer, G. M.; Maxwell, R. J.; Griffiths, J. R.; Pham, P.

    1990-01-01

    The effects of different doses of hydralazine and prostacyclin on the 31P magnetic resonance spectra of the LBDS1 fibrosarcoma were investigated and related to their effects on mean arterial blood pressure (MABP) and heart rate. The effect of reducing MABP by bleeding the animals, via the tail artery, was also investigated. Tumour spectral changes following high dose drug treatment (an increase in inorganic phosphate, a reduction in nucleotide triphosphates and a reduction in pH) were consistent with nutrient deprivation. These changes were dose dependent. Changes in MABP and heart rate were consistent with vasodilatation in normal tissues. However, for the same fall in MABP, hydralazine produced a greater rise in tumour inorganic phosphate (Pi) and a greater fall in tumour pH than did prostacyclin. Controlled bleeding was effective in reducing MABP. It also reduced tumour pH but had no significant effect on tumour Pi. The clinical application of the two drugs for reducing tumour blood flow and pH for therapy is likely to be limited by the large degree of hypotension necessary to produce an effect. The differential effect of the two drugs for the same fall in MABP may be related to different degrees of direct tumour vasodilatation or to a direct effect of hydralazine on tumour energy metabolism. The observation that controlled bleeding does not change tumour Pi is further evidence indicating that the degree of arterial hypotension is not the sole factor in determining tumour energy status. PMID:2223572

  5. Two protocols to measure mitochondrial capacity in women and adolescent girls: a 31P-MRS preliminary study.

    PubMed

    Willcocks, Rebecca Jane; Fulford, Jon; Barker, Alan Robert; Armstrong, Neil; Williams, Craig Anthony

    2014-05-01

    The phosphocreatine (PCr) recovery time constant (τ) following exercise provides a measure of mitochondrial oxidative capacity. The purpose of this investigation was to use 2 different protocols to determine τ in adolescent females. 31P-MR spectra were collected during 2 exercise tests in 6 adolescent girls (13.8 ± 0.3 y) and 7 women (23.2 ± 3.4 y). The first test consisted of 23 repeated 4 seconds maximal isometric calf contractions separated by 12-second recovery; PCr recovery between the final 18 contractions was used to calculate τ. The second test was a sustained 20-second maximal contraction; recovery was fitted with an exponential function to measure τ. PCr τ did not significantly differ between groups: (gated exercise: 4 girls: 16 ± 5 s, 7 women: 17 ± 5 s, p; sustained exercise: 6 girls: 19 ± 6 s, 7 women: 19 ± 4 s). Bland-Altman analysis demonstrated a close agreement between sustained and gated exercise. Both gated and sustained exercise appear feasible in a pediatric population, and offer a noninvasive evaluation of mitochondrial oxidative capacity.

  6. A 31P magnetic resonance spectroscopy study of mitochondrial function in skeletal muscle of patients with Parkinson's disease.

    PubMed

    Taylor, D J; Krige, D; Barnes, P R; Kemp, G J; Carroll, M T; Mann, V M; Cooper, J M; Marsden, C D; Schapira, A H

    1994-08-01

    The activity of complex I of the respiratory chain is decreased in the substantia nigra of patients with Parkinson's disease (PD) but the presence of this defect in skeletal muscle is controversial. Therefore, the mitochondrial function of skeletal muscle in patients with PD was investigated in vivo using 31P magnetic resonance spectroscopy. Results from 7 PD patients, 11 age matched controls and 9 mitochondrial myopathy patients with proven complex I deficiency were obtained from finger flexor muscle at rest, during exercise and in recovery from exercise. In resting muscle, the patients with mitochondrial myopathy showed a low PCr/ATP ratio, a low phosphorylation potential, a high P(i)/PCr ratio and a high calculated free [ADP]. During exercise, stores of high energy phosphate were depleted more rapidly than normal, while in recovery, the concentration of phosphocreatine and free ADP returned to pre-exercise values more slowly than normal. In contrast, the patients with PD were not significantly different from normal for any of these variables, and no abnormality of muscle energetics was detected. Three of the PD patients also had mitochondrial function assessed biochemically in muscle biopsies. No respiratory chain defect was identified in any of these patients by polarography or enzyme analysis when compared with age-matched controls. These results suggest that skeletal muscle is not a suitable tissue for the investigation and identification of the biochemical basis of the nigral complex I deficiency in PD.

  7. 31P Magic Angle Spinning NMR Spectroscopy of Paramagnetic Rare Earth-Substituted Keggin and Wells-Dawson Solids

    PubMed Central

    Huang, Wenlin; Schopfer, Mark; Zhang, Cheng; Howell, Robertha C.; Todaro, Louis; Gee, Becky A.; Francesconi, Lynn C.; Polenova, Tatyana

    2008-01-01

    Paramagnetic rare-earth elements have been examined as NMR structural probes in polyoxoanionic solids, which have a variety of applications as luminescent materials that are usually disordered and therefore intractable by traditional structural methods. Thirteen Keggin and Wells-Dawson polyoxotungstates containing substitutions with lanthanides of different effective magnetic moments have been examined by 31P magic angle spinning NMR spectroscopy. The electron-nuclear dipolar interaction dominating the spinning sideband envelopes is determined by the lanthanide’s magnetic moment and was found to be a sensitive probe of the nature of the polyoxoanion, of the positional isomerism, and of the ion stoichiometry. Electron-nuclear dipolar anisotropies computed based on the point-dipole approximation are generally in good agreement with the experimental results. The choice of a specific lanthanide as a structural probe can be tailored to the desired distance range between the phosphorus atoms and the paramagnetic centers to be probed. This approach is expected to be particularly useful in the paramagnetic polyoxoanionic materials lacking long-range order. PMID:18095677

  8. Characterization of the phosphoserine of pepsinogen using /sup 31/P nuclear magnetic resonance: corroboration of X-ray crystallographic results

    SciTech Connect

    Williams, S.P.; Bridger, W.A.; James, M.N.G.

    1986-10-21

    The endogenous phosphoserine residue in porcine pepsinogen has been titrated with use of phosphorus-31 nuclear magnetic resonance (/sup 31/P NMR). It has an observed pK/sub a/sub 2// of 6.7 and a narrow line width (approx. =10 Hz). The phosphate can be readily removed by an acid phosphatase from potato; however, it is resistant to hydrolysis by several alkaline phosphatases. The X-ray crystal structure of porcine pepsinogen at 1.8-A resolution shows a rather weak and diffuse region of electron density in the vicinity of the phosphorylated serine residue. This suggests considerable dynamic mobility or conformational disorder of the phosphate. In order to define more fully this behavior the NMR data have been used to corroborate these crystallographic results. All these physical data are consistent with a highly mobile phosphoserine residue on the surface of the zymogen and freely exposed to solvent. In addition, certain properties of this phosphoserine moiety on pepsinogen are similar to those of one of the phosphorylated residues of ovalbumin. The possible significance of this is discussed.

  9. Linking phosphorus sequestration to carbon humification in wetland soils by 31P and 13C NMR spectroscopy.

    PubMed

    Hamdan, Rasha; El-Rifai, Hasan M; Cheesman, Alexander W; Turner, Benjamin L; Reddy, K Ramesh; Cooper, William T

    2012-05-01

    Phosphorus sequestration in wetland soils is a prerequisite for long-term maintenance of water quality in downstream aquatic systems, but can be compromised if phosphorus is released following changes in nutrient status or hydrological regimen. The association of phosphorus with relatively refractory natural organic matter (e.g., humic substances) might protect soil phosphorus from such changes. Here we used hydrofluoric acid (HF) pretreatment to remove phosphorus associated with metals or anionic sorption sites, allowing us to isolate a pool of phosphorus associated with the soil organic fraction. Solution (31)P and solid state (13)C NMR spectra for wetland soils were acquired before and after hydrofluoric acid pretreatment to assess quantitatively and qualitatively the changes in phosphorus and carbon functional groups. Organic phosphorus was largely unaffected by HF treatment in soils dominated by refractory alkyl and aromatic carbon groups, indicating association of organic phosphorus with stable, humified soil organic matter. Conversely, a considerable decrease in organic phosphorus following HF pretreatment was detected in soils where O-alkyl groups represented the major fraction of the soil carbon. These correlations suggest that HF treatment can be used as a method to distinguish phosphorus fractions that are bound to the inorganic soil components from those fractions that are stabilized by incorporation into soil organic matter. © 2012 American Chemical Society

  10. Metal-insulator transition and magnetic fluctuations in polycrystalline Ru1 -xRhxP investigated by 31P NMR

    NASA Astrophysics Data System (ADS)

    Li, Shang; Kobayashi, Yoshiaki; Itoh, Masayuki; Hirai, Daigorou; Takagi, Hidenori

    2017-04-01

    31P NMR measurements have been made on polycrystalline samples to study a metal-insulator (MI) transition and magnetic fluctuations in Ru1 -xRhxP which has metallic (M), pseudogap (PG), insulating (I), and superconducting (SC) phases. We find that RuP undergoes a crossover from the high-temperature (high-T ) M phase to the PG phase with the pseudo spin-gap behavior probed by the nuclear spin-lattice relaxation rate at TPG=330 K . The first-order MI transition is observed to take place from the PG phase to the low-T nonmagnetic I phase with the spin-gap energy of 1250 K at TMI=270 K . In the PG phase of Ru1 -xRhxP with 0 ≤x <0.45 , an analysis based on the modified Korringa relation, which is applicable to an itinerant paramagnet with weak electron correlation, shows that antiferromagnetic (AFM) fluctuations described in the random-phase approximation are enhanced in the low-T and low-x region. Around the PG-M phase boundary at xc˜0.45 , there is the SC phase whose normal state has negligible electron-electron interaction. We discuss the MI transition, the crossover from the M phase to the PG phase, and the magnetic properties of each phase based on the band structure.

  11. Muscle fatigue in McArdle's disease studied by 31P-NMR: effect of glucose infusion.

    PubMed

    Lewis, S F; Haller, R G; Cook, J D; Nunnally, R L

    1985-12-01

    In muscle phosphorylase deficiency (McArdle's disease) there is an abnormally rapid fatigue during strenuous exercise. Increasing substrate availability to working muscle can improve exercise tolerance but the effect on muscle energy metabolism has not been studied. Using phosphorus-31 nuclear magnetic resonance (31P-NMR) we examined forearm muscle ATP, phosphocreatine (PCr), inorganic phosphate (Pi) and pH in a McArdle patient (MP) and two healthy subjects (HS) at rest and during intermittent maximal effort handgrip contractions under control conditions (CC) and during intravenous glucose infusion (GI). Under CC, MP gripped to impending forearm muscle contracture in 130 s with a marked decline in muscle PCr and a dramatic elevation in Pi. During GI, MP exercised easily for greater than 420 s at higher tensions and with attenuated PCr depletion and Pi accumulation. In HS, muscle PCr and Pi changed more modestly and were not affected by GI. In MP and HS, ATP changed little or not at all with exercise. The results suggest that alterations in the levels of muscle PCr and Pi but not ATP are involved in the muscle fatigue in McArdle's disease and the improved exercise performance during glucose infusion.

  12. Phospholipid fingerprints of milk from different mammalians determined by 31P NMR: towards specific interest in human health.

    PubMed

    Garcia, Cyrielle; Lutz, Norbert W; Confort-Gouny, Sylviane; Cozzone, Patrick J; Armand, Martine; Bernard, Monique

    2012-12-01

    Our objective was to identify and quantify phospholipids in milk from different species (human HM, cow CoM, camel CaM, and mare MM) using an optimised (31)P NMR spectroscopy procedure. The phospholipid fingerprints were species-specific with a broader variety of classes found in HM and MM; HM and CaM were richer in sphingomyelin (78.3 and 117.5μg/ml) and plasmalogens (27.3 and 24μg/ml), possibly important for infant development. Total phospholipid content was higher in CaM (0.503mM) and lower in MM (0.101mM) compared to HM (0.324mM) or CoM (0.265mM). Our optimised method showed good sensitivity, high resolution, and easy sample preparation with minimal loss of target molecules. It is suitable for determining the accurate composition of a large number of bioactive phospholipids with putative health benefits, including plasmalogens, and should aid in selecting appropriate ingredient sources for infant milk substitutes or fortifiers, and for functional foods dedicated to adults.

  13. Simple and effective exercise design for assessing in vivo mitochondrial function in clinical applications using 31P magnetic resonance spectroscopy

    PubMed Central

    Sleigh, Alison; Lupson, Victoria; Thankamony, Ajay; Dunger, David B.; Savage, David B.; Carpenter, T. Adrian; Kemp, Graham J.

    2016-01-01

    The growing recognition of diseases associated with dysfunction of mitochondria poses an urgent need for simple measures of mitochondrial function. Assessment of the kinetics of replenishment of the phosphocreatine pool after exercise using 31P magnetic resonance spectroscopy can provide an in vivo measure of mitochondrial function; however, the wider application of this technique appears limited by complex or expensive MR-compatible exercise equipment and protocols not easily tolerated by frail participants or those with reduced mental capacity. Here we describe a novel in-scanner exercise method which is patient-focused, inexpensive, remarkably simple and highly portable. The device exploits an MR-compatible high-density material (BaSO4) to form a weight which is attached directly to the ankle, and a one-minute dynamic knee extension protocol produced highly reproducible measurements of post-exercise PCr recovery kinetics in both healthy subjects and patients. As sophisticated exercise equipment is unnecessary for this measurement, our extremely simple design provides an effective and easy-to-implement apparatus that is readily translatable across sites. Its design, being tailored to the needs of the patient, makes it particularly well suited to clinical applications, and we argue the potential of this method for investigating in vivo mitochondrial function in new cohorts of growing clinical interest. PMID:26751849

  14. Simple and effective exercise design for assessing in vivo mitochondrial function in clinical applications using (31)P magnetic resonance spectroscopy.

    PubMed

    Sleigh, Alison; Lupson, Victoria; Thankamony, Ajay; Dunger, David B; Savage, David B; Carpenter, T Adrian; Kemp, Graham J

    2016-01-11

    The growing recognition of diseases associated with dysfunction of mitochondria poses an urgent need for simple measures of mitochondrial function. Assessment of the kinetics of replenishment of the phosphocreatine pool after exercise using (31)P magnetic resonance spectroscopy can provide an in vivo measure of mitochondrial function; however, the wider application of this technique appears limited by complex or expensive MR-compatible exercise equipment and protocols not easily tolerated by frail participants or those with reduced mental capacity. Here we describe a novel in-scanner exercise method which is patient-focused, inexpensive, remarkably simple and highly portable. The device exploits an MR-compatible high-density material (BaSO4) to form a weight which is attached directly to the ankle, and a one-minute dynamic knee extension protocol produced highly reproducible measurements of post-exercise PCr recovery kinetics in both healthy subjects and patients. As sophisticated exercise equipment is unnecessary for this measurement, our extremely simple design provides an effective and easy-to-implement apparatus that is readily translatable across sites. Its design, being tailored to the needs of the patient, makes it particularly well suited to clinical applications, and we argue the potential of this method for investigating in vivo mitochondrial function in new cohorts of growing clinical interest.

  15. 31P-magnetic resonance spectroscopy assessment of subnormal oxidative metabolism in skeletal muscle of renal failure patients.

    PubMed Central

    Moore, G E; Bertocci, L A; Painter, P L

    1993-01-01

    In hemodialysis patients, erythropoietin increases hemoglobin, but often the corresponding increase in peak oxygen uptake is low. The disproportionality may be caused by impaired energy metabolism. 31P-magnetic resonance spectroscopy was used to study muscle energy metabolism in 11 hemodialysis patients, 11 renal transplant recipients, and 9 controls. Measurements were obtained during rest, static hand-grip, and rhythmic hand-grip; recoveries were followed to baseline. During static hand-grip, there were no between-group differences in phosphocreatine (PCr), inorganic phosphate (Pi), or PCr/(PCr + Pi), although intracellular pH was higher in hemodialysis patients than transplant recipients. During rhythmic hand-grip, hemodialysis patients exhibited greater fatigue than transplant recipients or controls, and more reduction in PCr/(PCr + Pi) than transplant recipients. Intracellular pH was higher in controls than either hemodialysis patients or transplant recipients. Recoveries from both exercises were similar in all groups, indicating that subnormal oxidative metabolism was not caused by inability to make ATP. The rhythmic data suggest transplantation normalizes PCr/(PCr + Pi), but not pH. In hemodialysis patients, subnormal oxidative metabolism is apparently caused by limited exchange of metabolites between blood and muscle, rather than intrinsic oxidative defects in skeletal muscle. PMID:8432850

  16. Examination of P-OR bridging bond orders in phosphate monoesters using (18)O isotope shifts in 31P NMR.

    PubMed

    Sorensen-Stowell, Kerensa; Hengge, Alvan C

    2005-06-10

    Evidence indicates that phosphate monoesters undergo hydrolysis by a loose transition state with extensive bond fission to the leaving group. It has been proposed that part of the high dependence of the rate on the leaving group pKa (betalg = -1.23) arises from weaker ester bonds in the reactants as the pKa of the leaving group decreases, on the basis of X-ray structures and calculations. In contrast, IR and Raman studies suggest that the leaving group has little effect on the length of the P-OR bridging bond in solution. To gather additional data on this issue, we have used (18)O isotopic shifts in 31P NMR to monitor the bond order of P-O bonds in a range of phosphate esters with different leaving groups. Using this technique, we have been able to evaluate whether significant changes are observed in the P-O bond orders for the bridging and nonbridging positions of methyl, ethyl, phenethyl, propargyl, phenyl, and p-nitrophenyl phosphate using [(16)O(18)O] labeled species in deuterium oxide. The results indicate that the bridging and nonbridging bond orders to phosphorus in phosphate monoesters are not significantly altered by differences in the pKa of the leaving group or by the counterion of the phosphate ester dianion.

  17. Probing potential medium effects on phosphate ester bonds using 18O isotope shifts on 31P NMR.

    PubMed

    Sorensen-Stowell, Kerensa; Hengge, Alvan C

    2005-10-14

    Dipolar aprotic cosolvents, such as DMSO and acetonitrile, accelerate the rates of hydrolysis of phosphate monoester dianions. It has been speculated that the rate acceleration arises from the disruption of hydrogen bonding to the phosphoryl group. An aqueous solvation shell can stabilize the dianionic phosphoryl group by forming hydrogen bonds to the phosphoryl oxygens, whereas solvents such as DMSO are incapable of forming such bonds. It has been proposed that the loss of stabilization could result in a weakened P-OR ester bond, contributing to the observed faster rate of hydrolysis. Computational results support this notion. We have used the 18O-induced perturbation to the 31P chemical shift to ascertain whether solvent changes result in alterations to the P-O(R) bond. We have studied 16O18O-labeled methyl, ethyl, phenyl, p-nitrophenyl, diethyl p-nitrophenyl, triphenyl, and di-tert-butyl ethyl phosphate in the solvents water, methanol, chloroform, acetonitrile, dioxane, and DMSO. The results suggest no significant solvent-induced weakening of the phosphate ester bonds in any of the solvents tested, and this is unlikely to be a significant source for the acceleration of hydrolysis in mixed solvents.

  18. Interrelations of muscle functional MRI, diffusion-weighted MRI and (31) P-MRS in exercised lower back muscles.

    PubMed

    Hiepe, Patrick; Gussew, Alexander; Rzanny, Reinhard; Anders, Christoph; Walther, Mario; Scholle, Hans-Christoph; Reichenbach, Jürgen R

    2014-08-01

    Exercise-induced changes of transverse proton relaxation time (T2 ), tissue perfusion and metabolic turnover were investigated in the lower back muscles of volunteers by applying muscle functional MRI (mfMRI) and diffusion-weighted imaging (DWI) before and after as well as dynamic (31) P-MRS during the exercise. Inner (M. multifidus, MF) and outer lower back muscles (M. erector spinae, ES) were examined in 14 healthy young men performing a sustained isometric trunk-extension. Significant phosphocreatine (PCr) depletions ranging from 30% (ES) to 34% (MF) and Pi accumulations between 95% (left ES) and 120%-140% (MF muscles and right ES) were observed during the exercise, which were accompanied by significantly decreased pH values in all muscles (∆pH ≈ -0.05). Baseline T2 values were similar across all investigated muscles (approximately 27 ms at 3 T), but revealed right-left asymmetric increases (T2 ,inc ) after the exercise (right ES/MF: T2 ,inc  = 11.8/9.7%; left ES/MF: T2 ,inc  = 4.6/8.9%). Analyzed muscles also showed load-induced increases in molecular diffusion D (p = .007) and perfusion fraction f (p = .002). The latter parameter was significantly higher in the MF than in the ES muscles both at rest and post exercise. Changes in PCr (p = .03), diffusion (p < .01) and perfusion (p = .03) were strongly associated with T2,inc , and linear mixed model analysis revealed that changes in PCr and perfusion both affect T2,inc (p < .001). These findings support previous assumptions that T2 changes are not only an intra-cellular phenomenon resulting from metabolic stress but are also affected by increased perfusion in loaded muscles.

  19. Effect of Ca:Mg ratio on precipitated P species identified using 31P solid state NMR

    NASA Astrophysics Data System (ADS)

    Manimel Wadu, M.

    2009-04-01

    M.C.W. Manimel Wadu1, O.O Akinremi1, S. Kroeker2 1Department of Soil Science, University of Manitoba, Winnipeg, R3T 2N2, Canada 2Department of Chemistry, University of Manitoba, Winnipeg, R3T 2N2, Canada Agronomic efficiency of added P fertilizer is reduced by the precipitation reactions with the exchangeable Ca and Mg in calcareous soils. We hypothesized that the ratio of Ca to Mg on the soil exchange complex will affect the species of P that is precipitated and its solubility in the soil. A laboratory experiment was conducted using a model calcareous soil system which was composed of resin (Amberlite IRP69) and sand coated with CaCO3 packed into a column. The resin was pre saturated with Ca and Mg in order to achieve five different saturation ratios of Ca:Mg approximately as 100:0, 70:30, 50:50, 30:70 and 0:100. Monoammonium Phosphate was applied to the soil surface to simulate one-dimensional diffusive transport. The column was then incubated for 2 weeks. Chemical analysis for water and acid soluble P, pH, NH4, Ca and Mg was performed on 2mm sections of the soil to a depth of 10 cm. This paper will present and discuss the distribution of P along the soil column. Unlike similar studies that have speculated on the precipitation of P, this study will identify and quantify the P species that is formed using 31P solid state NMR technique. Such knowledge will be helpful in understanding the effect of Ca and Mg on P availability in calcareous system and the role of each cation on P precipitation. Key words: P fertilizers, Ca, Mg, model system, solid state NMR

  20. Dietary fat modulation of mammary tumor growth and metabolism demonstrated by /sup 31/P-nuclear magnetic resonance

    SciTech Connect

    Erickson, K.L.; Buckman, D.K.; Hubbard, N.E.; Ross, B.

    1986-03-05

    The relationship of dietary fat concentration and saturation on the growth and metabolic activity of line 168 was studied using syngeneic mice fed 6 experimental diets before and during tumor growth. Tumor latency was significantly greater for mice fed a diet containing the minimum of essential fatty acids (EFA, 0.5% corn oil) or 8% coconut oil (SF) than for mice fed 8 or 20% safflower oil (PUF) or 20% SF. Changes in dietary fat resulted in alterations of tumor cell and serum fatty acid composition but not the number of inflammatory cells infiltrating the tumor. /sup 31/P-surface coil NMR was used to measure possible changes in tumor metabolism in vivo. Although pH decreased from 7.2 to 6.6 as the tumor volume increased, there was no difference in pH among dietary groups. There was an inverse relationship between both sugar phosphate (SP)/Pi and ATP/Pi ratios and tumor volume; those ratios for mice fed an EFA deficient or minimal EFA diet decreased at a different rate than ratios for mice fed diets with additional fat. Tumors of mice fed diets containing no or a low level (0.3%) of 18:2 had higher SP/ATP ratios than mice fed diets containing a moderate level (approx. 4%) of 18:2. Thus, high levels of dietary fat had a significant effect on promotion of mammary tumors during early stages of tumor growth. Differences in tumor volume associated with dietary fat may be related to changes in the levels of high energy phosphate metabolites.

  1. Energetics of acute pressure overload of the porcine right ventricle. In vivo 31P nuclear magnetic resonance.

    PubMed Central

    Schwartz, G G; Steinman, S; Garcia, J; Greyson, C; Massie, B; Weiner, M W

    1992-01-01

    In vivo 31P nuclear magnetic resonance (NMR) spectroscopy of the right ventricular (RV) free wall was employed to determine (a) whether phosphorus energy metabolites vary reciprocally with workload in the RV and (b) the mechanisms that limit RV contractile function in acute pressure overload. In 20 open-chest pigs, phosphocreatine (PCr)/ATP ratio (an index of energy metabolism inversely related to free ADP concentration), myocardial blood flow (microspheres), and segment shortening (sonomicrometry, n = 14) were measured at control (RV systolic pressure 31 +/- 1 mm Hg), and with pulmonary artery constriction to produce moderate pressure overload (RV systolic pressure 45 +/- 1 mm Hg), and maximal pressure overload before overt RV failure and systemic hypotension (RV systolic pressure 60 +/- 1 mm Hg). With moderate pressure overload, PCr/ATP declined to 89% of control (P = 0.01), while contractile function increased. Adenosine (n = 10, mean dose 0.16 mg/kg-min) increased RV blood flow by an additional 41% without increasing PCr/ATP, indicating that coronary reserve was not depleted and that the decrease in PCr/ATP from control was not due to ischemia. With maximal pressure overload and incipient RV failure, PCr/ATP fell further to 81% of control and RV blood flow did not increase further, even with adenosine. Thus: (a) The decline in PCr/ATP with moderate RV pressure overload, without evident ischemia or contractile dysfunction, supports the positive regulation of oxidative phosphorylation by ATP hydrolysis products. (b) Depletion of RV coronary flow reserve accompanies the onset of RV failure at maximal pressure overload. Images PMID:1541681

  2. Partial trisomy 2q due to a maternal balanced translocation t(2;22) (q31;p12)

    SciTech Connect

    Steinberg, L.S.; Bleiman, M.; Punnett, H.H.

    1994-09-01

    Features consistent among reported patients with 2q duplications due to familial translocations or de novo duplications include pre- and postnatal growth failure, ocular defects such as congenital glaucoma, cardiac defects, micrognathia, urogenital defects, renal defects, connective tissue laxity, neurologic defects, and dermatologic abnormalities. Genotype/phenotype correlations of patients with trisomy 2q due to familial translocations are complicated by the presence of the deletions of the other chromosome involved. We have had the opportunity to observe `pure` trisomy 2q31-qter resulting from adjacent-1 segregation from 46,XX,t(2;22)(q31;p12) in a carrier mother with apparent loss of the 22 NOR region. He was the 2453 gm product of a gestation complicated by gestational diabetes to a 29-year-old G1 P0 mother and a 30-year-old father. At birth, he was noted to have hypotonia, micrognathia, microphthalmia, left cryptorchidism, hypospadias, bilateral clinodactyly of the fifth digits, mild hyperextensibility of the joints, dry skin disorder, and bilateral hydronephrosis by ultrasound. He was treated for hypoglycemia in the nursery and had a vesicostomy at two months for vesicoureteral reflux. A hearing test at two months found moderate hearing loss in the right ear and mild to moderate hearing loss in the left ear. At 3 months he had surgery for a PDA and bilateral glaucoma and was treated for periods of hypothermia and type IV renal tubular acidosis. This patient and others with unbalanced translocations involving the NOR region of an acrocentric chromosome allow for genotype/phenotype correlation of the `pure` trisomic region.

  3. Forearm muscle metabolism studied using (31)P-MRS during progressive exercise to fatigue after Acz administration.

    PubMed

    Kowalchuk, J M; Smith, S A; Weening, B S; Marsh, G D; Paterson, D H

    2000-07-01

    The effects of acetazolamide (Acz)-induced carbonic anhydrase inhibition (CAI) on muscle intracellular thresholds (T) for intracellular pH (pH(i)) and inorganic phosphate-to-phosphate creatine ratio (P(i)/PCr) and the plasma lactate (La(-)) threshold were examined in nine adult male subjects performing forearm wrist flexion exercise to fatigue. Exercise consisted of raising and lowering (1-s contraction, 1-s relaxation) a cylinder whose volume increased at a rate of 200 ml/min. The protocol was performed during control (Con) and after 45 min of CAI with Acz (10 mg/kg body wt iv). T(pH(i)) and T(P(i)/PCr), determined using (31)P-labeled magnetic resonance spectroscopy (MRS), were similar in Acz (722 +/- 50 and 796 +/- 75 mW, respectively) and Con (855 +/- 211 and 835 +/- 235 mW, respectively). The pH(i) was similar at end-exercise (6.38 +/- 0.10 Acz and 6.43 +/- 0.22 Con), but pH(i) recovery was slowed in Acz. In a separate experiment, blood was sampled from a deep arm vein at the elbow for determination of plasma lactate concentration ([La(-)](pl)) and T(La(-)). [La(-)](pl) was lower (P < 0.05) in Acz than Con (3.7 +/- 1.7 vs. 5.0 +/- 1.7 mmol/l) at end-exercise and in early recovery, but T(La(-)) was higher (1,433 +/- 243 vs. 1,041 +/- 414 mW, respectively). These data suggest that the lower [La(-)](pl) seen with CAI was not due to a delayed onset or rate of muscle La(-) accumulation but may be related to impaired La(-) removal from muscle.

  4. Response of a non-Hodgkin lymphoma to /sup 60/Co therapy monitored by 31P MRS in situ

    SciTech Connect

    Ng, T.C.; Vijayakumar, S.; Majors, A.W.; Thomas, F.J.; Meaney, T.F.; Baldwin, N.J.

    1987-10-01

    High quality /sup 31/P MR spectra (signal to noise ratio (S/N) approximately 18, 15 min acquisition for each spectrum) were consistently obtained with surface coils over a period of 6-week RT. Both transient and steady state alterations in metabolites in response to RT were found in this case. The transient changes occurred during the first 3 hr immediately after the 3rd fractionated RT, these changes include the transient elevation of the PCr resonance, a decrease in PDE and an increase in intracellular pH. The monitoring showed that the metabolites approached steady state approximately 2 hr after the fractionated radiation intervention, suggesting that in vivo MRS can be useful for studying the dynamics of tumor response to RT such as repair of potential lethal damage, growth delay, and reoxygenation etc. The steady-state MR spectra showed the net response to each intervention and can clinically be useful for predicting and measuring the result of the fractionated RT. In this case study, the PDE peak which contains the phospholipid metabolites GPC and GPE, is the most sensitive resonance in response to RT. After the 3rd RT, prior to tumor size reduction, the PDE to ATP ratio decreased 33% and intracellular pH increased to 7.34 +/- 0.05 from 7.27 +/- 0.05. In the subsequent RT interventions, both the tumor size and PDE/ATP ratio continually decreased whereas the pH values remained alkaline and fluctuated around 7.34 to 7.65. The data suggest that the phospholipid metabolite PDE may signal important alterations in membrane metabolism that eventually lead to cell death.

  5. Brief Report: Approaches to [Superscript 31]P-MRS in Awake, Non-Sedated Children with and without Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Erickson, Laura C.; Scott-Van Zeeland, Ashley A.; Hamilton, Gavin; Lincoln, Alan; Golomb, Beatrice A.

    2012-01-01

    We piloted a suite of approaches aimed to facilitate a successful series of up to four brain and muscle [superscript 31]Phosphorus-Magnetic Resonance Spectroscopy ([superscript 31]P-MRS) scans performed in one session in 12 "awake", non-sedated subjects (ages 6-18), 6 with autism spectrum disorders (ASD) and 6 controls. We targeted advanced…

  6. Brief Report: Approaches to [Superscript 31]P-MRS in Awake, Non-Sedated Children with and without Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Erickson, Laura C.; Scott-Van Zeeland, Ashley A.; Hamilton, Gavin; Lincoln, Alan; Golomb, Beatrice A.

    2012-01-01

    We piloted a suite of approaches aimed to facilitate a successful series of up to four brain and muscle [superscript 31]Phosphorus-Magnetic Resonance Spectroscopy ([superscript 31]P-MRS) scans performed in one session in 12 "awake", non-sedated subjects (ages 6-18), 6 with autism spectrum disorders (ASD) and 6 controls. We targeted advanced…

  7. Coal liquefaction process streams characterization and evaluation: Estimation of total phenol concentrations in coal liquefaction resids by [sup 31]P NMR spectroscopy

    SciTech Connect

    Mohan, J.T.; Verkade, J.G. )

    1992-11-01

    In this study, Iowa State University researchers used [sub 31]P-tagged reagents to derivatize the labile hydrogen functional groups in the THF-soluble portion of 850[degrees]F[sup +] distillation resid materials and the THF-soluble portion of process oils derived from direct coal liquefaction.[sup 31]P-NMR was used to analyze the derivatized samples. NMR peak assignments can be made by comparison to model compounds similarly derivatized. Species can be quantified by integration of the NMR signals. Different [sup 31]P-NMR tagged reagents can be used to produce different degrees of peak resolution in the NMR spectrum. This, in turn, partially dictates the degree of speciation and/or quantification of species, or classes of compounds, that can be accomplished. Iowa State chose a [sup 31]P-tagged reagent (ClPOCMe[sub 2]CMe[sub 2]O) which was shown previously to be particularly useful in the derivatization of phenols. The derivatized samples all exhibited a small group of peaks attributed to amines and a broad group of peaks in the phenol region. The presence of paramagnetic species in the samples caused the NMR signals to broaden. Electron paramagnetic resonance (EPR) spectra confirmed the presence of paramagnetic organic free radicals in selected samples. Various methods were employed to process the NMR data. The complexity and broadness of the phenol peak, however, made speciation of the phenols impractical.

  8. Coal liquefaction process streams characterization and evaluation: Estimation of total phenol concentrations in coal liquefaction resids by {sup 31}P NMR spectroscopy

    SciTech Connect

    Mohan, J.T.; Verkade, J.G.

    1992-11-01

    In this study, Iowa State University researchers used {sub 31}P-tagged reagents to derivatize the labile hydrogen functional groups in the THF-soluble portion of 850{degrees}F{sup +} distillation resid materials and the THF-soluble portion of process oils derived from direct coal liquefaction.{sup 31}P-NMR was used to analyze the derivatized samples. NMR peak assignments can be made by comparison to model compounds similarly derivatized. Species can be quantified by integration of the NMR signals. Different {sup 31}P-NMR tagged reagents can be used to produce different degrees of peak resolution in the NMR spectrum. This, in turn, partially dictates the degree of speciation and/or quantification of species, or classes of compounds, that can be accomplished. Iowa State chose a {sup 31}P-tagged reagent (ClPOCMe{sub 2}CMe{sub 2}O) which was shown previously to be particularly useful in the derivatization of phenols. The derivatized samples all exhibited a small group of peaks attributed to amines and a broad group of peaks in the phenol region. The presence of paramagnetic species in the samples caused the NMR signals to broaden. Electron paramagnetic resonance (EPR) spectra confirmed the presence of paramagnetic organic free radicals in selected samples. Various methods were employed to process the NMR data. The complexity and broadness of the phenol peak, however, made speciation of the phenols impractical.

  9. Blood flow and muscle bio-energetics by 31P-nuclear magnetic resonance after local cold acclimation.

    PubMed

    Savourey, G; Clerc, L; Vallerand, A L; Leftheriotis, G; Mehier, H; Bittel, J H

    1992-01-01

    To clarify the origin of local cold adaptation and to define precisely its influence on muscle bio-energetics during local exercise, five subjects were subjected to repeated 5 degrees C cold water immersion of the right hand and forearm. The first aim of our investigation was therefore carried out by measuring local skin temperatures and peripheral blood flow during a cold hand test (5 degrees C, 5 min) followed by a 10-min recovery period. The 31P by nuclear magnetic resonance (31PNMR) muscle bio-energetic changes, indicating possible heat production changes, were measured during the recovery period. The second aim of our investigation was carried out by measuring 31PNMR muscle bioenergetics during handgrip exercise (10% of the maximal voluntary contraction for 5 min followed by a 10-min recovery period) performed both at a comfortable ambient temperature (22 degrees C; E) and after a cold hand test (EC), before and after local cold adaptation. Local cold adaptation, confirmed by warmer skin temperatures of the extremities (+30%, P less than 0.05), was related more to an increased peripheral blood flow, as shown by the smaller decrease in systolic peak [-245 (SEM 30) Hz vs -382 (SEM 95) Hz, P less than 0.05] than to a change in local heat production, because muscle bioenergetics did not vary. Acute local cold immersion decreased the inorganic phosphate:phosphocreatine (PC) ratio during EC compared to E [+0.006 (SEM 0.010) vs +0.078 (SEM 0.002) before acclimation and +0.029 (SEM 0.002) vs +0.090 (SEM 0.002) after acclimation respectively, P less than 0.05] without significant change in the PC:beta-adenosine triphosphate ratio and pH. Local adaptation did not modify these results statistically. The recovery of PC during E increased after acclimation [9.0 (SEM 0.2) min vs 3.0 (SEM 0.4) min, P less than 0.05]. These results suggested that local cold adaptation is related more to peripheral blood flow changes than to increased metabolic heat production in the muscle.

  10. In vivo mouse myocardial (31)P MRS using three-dimensional image-selected in vivo spectroscopy (3D ISIS): technical considerations and biochemical validations.

    PubMed

    Bakermans, Adrianus J; Abdurrachim, Desiree; van Nierop, Bastiaan J; Koeman, Anneke; van der Kroon, Inge; Baartscheer, Antonius; Schumacher, Cees A; Strijkers, Gustav J; Houten, Sander M; Zuurbier, Coert J; Nicolay, Klaas; Prompers, Jeanine J

    2015-10-01

    (31)P MRS provides a unique non-invasive window into myocardial energy homeostasis. Mouse models of cardiac disease are widely used in preclinical studies, but the application of (31)P MRS in the in vivo mouse heart has been limited. The small-sized, fast-beating mouse heart imposes challenges regarding localized signal acquisition devoid of contamination with signal originating from surrounding tissues. Here, we report the implementation and validation of three-dimensional image-selected in vivo spectroscopy (3D ISIS) for localized (31)P MRS of the in vivo mouse heart at 9.4 T. Cardiac (31)P MR spectra were acquired in vivo in healthy mice (n = 9) and in transverse aortic constricted (TAC) mice (n = 8) using respiratory-gated, cardiac-triggered 3D ISIS. Localization and potential signal contamination were assessed with (31)P MRS experiments in the anterior myocardial wall, liver, skeletal muscle and blood. For healthy hearts, results were validated against ex vivo biochemical assays. Effects of isoflurane anesthesia were assessed by measuring in vivo hemodynamics and blood gases. The myocardial energy status, assessed via the phosphocreatine (PCr) to adenosine 5'-triphosphate (ATP) ratio, was approximately 25% lower in TAC mice compared with controls (0.76 ± 0.13 versus 1.00 ± 0.15; P < 0.01). Localization with one-dimensional (1D) ISIS resulted in two-fold higher PCr/ATP ratios than measured with 3D ISIS, because of the high PCr levels of chest skeletal muscle that contaminate the 1D ISIS measurements. Ex vivo determinations of the myocardial PCr/ATP ratio (0.94 ± 0.24; n = 8) confirmed the in vivo observations in control mice. Heart rate (497 ± 76 beats/min), mean arterial pressure (90 ± 3.3 mmHg) and blood oxygen saturation (96.2 ± 0.6%) during the experimental conditions of in vivo (31)P MRS were within the normal physiological range. Our results show that respiratory-gated, cardiac-triggered 3D ISIS allows for non-invasive assessments of in vivo

  11. Hypertrophic cardiomyopathy in young Maine Coon cats caused by the p.A31P cMyBP-C mutation - the clinical significance of having the mutation

    PubMed Central

    2011-01-01

    Background In Maine Coon (MC) cats the c.91G > C mutation in the gene MYBPC3, coding for cardiac myosin binding protein C (cMyBP-C), is associated with feline hypertrophic cardiomyopathy (fHCM). The mutation causes a substitution of an alanine for a proline at residue 31 (p.A31P) of cMyBP-C. The pattern of inheritance has been considered autosomal dominant based on a single pedigree. However, larger studies are needed to establish the significance of cats being heterozygous or homozygous for the mutation with respect to echocardiographic indices and the probability of developing fHCM. The objective of the present study was to establish the clinical significance of being homozygous or heterozygous for the p.A31P cMyBP-C mutation in young to middle-aged cats. Methods The cohort consisted of 332 MC cats, 282 cats < 4 years (85%). All cats were examined by 2-D and M-mode echocardiography. DNA was extracted from blood samples or buccal swabs and screened for the p.A31P cMyBP-C mutation in exon 3 of the gene, using polymerase chain reaction followed by DNA sequencing. Results The fHCM prevalence was 6.3% in the cohort. Eighteen cats were homozygous and 89 cats were heterozygous for the mutation. The odds ratio for having fHCM for homozygous cats was 21.6 (95% confidence interval 7.01-66.2) - when the group of equivocal cats was categorized as non-affected. Overall, 50% of the cats that were homozygous for the mutation had fHCM. p.A31P heterozygosity was not associated with a significant odds ratio for fHCM. In cats in the 4 to 6 years of age range a similar, non significant, odds ratio was seen in heterozygous cats. Only two cats over four years were homozygous and both were diagnosed with fHCM. Conclusion As there is no significant odds ratio associated with being heterozygous for the pA31P cMyBP-C mutation at this age, the mutation must have a very low penetrance in this group. From our data it would appear that most MC cats that develop fHCM due to the p.A31P mutation

  12. Differences in nucleotide compartmentation and energy state in isolated and in situ rat heart: assessment by 31P-NMR spectroscopy.

    PubMed

    Williams, J P; Headrick, J P

    1996-08-07

    Free cytosolic concentrations of ATP, PCr, ADP and 5'-AMP, and the cytosolic [ATP]/[ADP].[Pi] ratio, were determined in isolated and in situ rat hearts using 31P-NMR spectroscopy. Total tissue metabolite concentrations were determined by HPLC analysis of freeze-clamped, perchloric acid-extracted tissue. In in situ myocardium the PCr/ATP ratio was 2.7 +/- 0.2 determined from 31P-NMR data (using either PCr/beta-NTP or PCr/gamma-NTP), and 1.9 +/- 0.1 (P < 0.01) determined from total tissue concentrations. 31P-NMR-determined and total tissue [PCr] were in excellent agreement (49.6 +/- 8.4 and 49.5 +/- 1.0 mumol.g-1 dry wt, respectively), whereas 31P-NMR-determined [ATP] (18.6 +/- 3.2 mumol.g-1 dry wt) was only 71% of the total tissue concentration (26.1 +/- 1.7 mumol.g-1 dry wt, P < 0.01). Isolation and Langendorff perfusion of rat hearts with glucose as substrate reduced total tissue [ATP] and [PCr] and the 31P-NMR-determined PCr/ATP ratio fell to 1.5 +/- 0.1. This value agreed well with the total tissue ratio of 1.4 +/- 0.1, and there was excellent agreement between 31P-NMR-determined and total tissue [PCr] and [ATP] values in the perfused heart. Addition of pyruvate to perfusate increased the 31P-NMR-determined PCr/ATP ratio to 1.7 +/- 0.1 due to elevated [PCr], and there remained excellent agreement between NMR-determined and total tissue [PCr] and [ATP] values. Free cytosolic [ADP] (from the creatine kinase equilibrium) was 5% of total tissue ADP, and free cytosolic [5'-AMP] (from the adenylate kinase equilibrium) ranged from 0.2-0.3% of total tissue 5'-AMP. Bioenergetic state, indexed by [ATP]/[ADP].[Pi], was much lower in isolated perfused hearts (30 mM-1) vs. in situ myocardium (approximately 150 mM-1). In summary, we observe a substantial disproportionality between total tissue PCr/ATP and 31P-NMR-determined PCr/ATP in highly energised in situ myocardium but not in isolated perfused hearts. This appears due to an NMR invisible ATP compartment approximating 29

  13. Repeatability of 31P MR spectroscopic imaging in the human brain at 7 T with and without the Nuclear Overhauser Effect

    PubMed Central

    Lagemaat, Miriam W.; van de Bank, Bart L.; Sati, Pascal; Li, Shizhe; Maas, Marnix C.; Scheenen, Tom W.J.

    2015-01-01

    An often employed strategy to enhance signals in 31P MR spectroscopy is the generation of the nuclear Overhauser effect (NOE) by saturating the water resonance. However, NOE allegedly increases the variability of the 31P data, because variation is reported in NOE enhancements. This would negate the SNR gain it generates. We hypothesized that variation in NOE enhancement values is not due to variability in the NOE itself, but that it is attributable to measurement uncertainties in the values used to calculate the enhancement. If true, the expected increase in SNR with NOE would improve the repeatability of 31P MR spectroscopy measurements. To verify this hypothesis, a repeatability study of native and NOE-enhanced 31P MRSI was performed in the brain of 7 healthy volunteers at 7T. The repeatability coefficient (RC) and the coefficient of variation in repeated measurements (CoVrepeat) were determined per method, and the 95% limits of agreement (LoA) between native and NOE-enhanced signals were calculated. The variation between the methods, defined by the LoA, is at least as great as that predicted by the RC of each method. The sources of variation in NOE enhancements were determined using variance component analysis. In the 7 metabolites with a positive NOE enhancement (9 metabolite resonances assessed), CoVrepeat improved on average by 15%. The LoAs could be explained by the RCs of the individual methods for the majority of the metabolites, generally confirming our hypothesis. Variation in NOE enhancement was mainly attributable to the factor repeat, but between-voxel effects were also present for phoshpoethanolamine and (glycero)phosphocholine. CoVrepeat and fitting error were strongly correlated and improved with positive NOE. Our findings generally indicate that NOE enhances the signal of the metabolites, improving the repeatability of metabolite measurements. Additional variability due to NOE was minimal. These findings encourage the use of NOE-enhanced 31P MRSI

  14. Myosin-binding protein C DNA variants in domestic cats (A31P, A74T, R820W) and their association with Hypertrophic Cardiomyopathy

    PubMed Central

    LONGERI, M.; FERRARI, P.; KNAFELZ, P.; MEZZELANI, A.; MARABOTTI, A.; MILANESI, L.; PERTICA, G.; POLLI, M.; BRAMBILLA, P.G.; KITTLESON, M.; LYONS, L.A.; PORCIELLO, F.

    2012-01-01

    Background Two mutations in the MYBPC3 gene have been identified in Maine Coon (MCO) and Ragdoll (RD) cats with hypertrophic cardiomyopathy (HCM). Objective The present study examines the frequency of these mutations and of the A74T polymorphism to describe their worldwide distribution and correlation with echocardiography. Animals 1855 cats representing 28 breeds and random bred cats world-wide of which 446 underwent echocardiographic examination. Methods This is a prospective cross sectional study. Polymorphisms were genotyped using Illumina VeraCode GoldenGate or by direct sequencing. The disease status was defined by echocardiography according to established guidelines. Odds ratios for the joint probability of having HCM and the alleles were calculated by meta-analysis. Functional analysis was simulated. Results The MYBPC3 A31P and R820W were restricted to MCO and RD respectively. Both purebred and random bred cats had HCM and the incidence increased with age. The A74T polymorphism was not associated with any phenotype. HCM was most prevalent in MCO homozygote for the A31P mutation and the penetrance increased with age. The penetrance of the heterozygote genotype was lower (0.08) compared to the P/P genotype (0.58) in MCO. Conclusions and Clinical Importance A31P mutation occurs frequently in MCO cats. The high incidence of HCM in homozygotes for the mutation supports the causal nature of the A31P mutation. Penetrance is incomplete for heterozygotes at A31P locus, at least at a young age. The A74T variant does not appear to be correlated with HCM. PMID:23323744

  15. High resolution in vivo 31P-MRS of the liver: potential advantages in the assessment of non-alcoholic fatty liver disease.

    PubMed

    Jeon, Min Jeong; Lee, Yunjung; Ahn, Sangdoo; Lee, Chulhyun; Kim, Ok-Hee; Oh, Byung-Chul; Yu, Ungsik; Kim, Hyeonjin

    2015-09-01

    Biopsy remains the current gold-standard for assessing non-alcoholic fatty liver disease (NAFLD). To develop a non-invasive means of assessing the disease, 31P magnetic resonance spectroscopy (31P-MRS) has been explored, but the severe spectral overlaps and low signal-to-noise-ratio in 31P-MRS spectra at clinical field strength are clearly limiting factors. To investigate potential advantages of high resolution in vivo 31P-MRS in assessing NAFLD. The study was conducted at 9.4T in control and carbon tetrachloride (CCl4)-treated rats. Rats were divided according to histopathologic findings into a control group (n = 15), a non-alcoholic steatohepatitis group (n = 17), and a cirrhosis group (n = 12). Data were presented with different reference peaks that are commonly used for peak normalization such as total phosphorous signal, phosphomonoester + phosphodiester (PME + PDE), and nucleotide triphosphate (NTP). Then, multivariate analyses were performed. In all spectra PME and PDE were well resolved into phosphoethanolamine (PE) and phosphocholine (PC), and into glycerophosphorylethanolamine (GPE) and glycerophosphorylcholine (GPC), respectively. Those MRS measures quantifiable only in highly resolved spectra had higher correlations with histology than those conventional MRS measures such as PME, PDE, and NTP. The optimized partial least-squares discriminant analysis (PLS-DA) model correctly classified 79% (22/28) of the rats in the training set and correctly predicted 69% (11/16) of the rats in the test set. PE, PC, GPE, GPC, and nicotinamide adenine dinucleotide phosphate (NADP) that can be separately quantifiable in highly resolved spectra may further improve the potential efficacy of 31P-MRS in the diagnosis of NAFLD. © The Foundation Acta Radiologica 2014.

  16. Myosin-binding protein C DNA variants in domestic cats (A31P, A74T, R820W) and their association with hypertrophic cardiomyopathy.

    PubMed

    Longeri, M; Ferrari, P; Knafelz, P; Mezzelani, A; Marabotti, A; Milanesi, L; Pertica, G; Polli, M; Brambilla, P G; Kittleson, M; Lyons, L A; Porciello, F

    2013-01-01

    Two mutations in the MYBPC3 gene have been identified in Maine Coon (MCO) and Ragdoll (RD) cats with hypertrophic cardiomyopathy (HCM). This study examined the frequency of these mutations and of the A74T polymorphism to describe their worldwide distribution and correlation with echocardiography. 1855 cats representing 28 breeds and random-bred cats worldwide, of which 446 underwent echocardiographic examination. This is a prospective cross-sectional study. Polymorphisms were genotyped by Illumina VeraCode GoldenGate or by direct sequencing. The disease status was defined by echocardiography according to established guidelines. Odds ratios for the joint probability of having HCM and the alleles were calculated by meta-analysis. Functional analysis was simulated. The MYBPC3 A31P and R820W were restricted to MCO and RD, respectively. Both purebred and random-bred cats had HCM and the incidence increased with age. The A74T polymorphism was not associated with any phenotype. HCM was most prevalent in MCO homozygote for the A31P mutation and the penetrance increased with age. The penetrance of the heterozygote genotype was lower (0.08) compared with the P/P genotype (0.58) in MCO. A31P mutation occurs frequently in MCO cats. The high incidence of HCM in homozygotes for the mutation supports the causal nature of the A31P mutation. Penetrance is incomplete for heterozygotes at A31P locus, at least at a young age. The A74T variant does not appear to be correlated with HCM. Copyright © 2013 by the American College of Veterinary Internal Medicine.

  17. Teaching 1H NMR Spectrometry Using Computer Modeling.

    ERIC Educational Resources Information Center

    Habata, Yoichi; Akabori, Sadatoshi

    2001-01-01

    Molecular modeling by computer is used to display stereochemistry, molecular orbitals, structure of transition states, and progress of reactions. Describes new ideas for teaching 1H NMR spectroscopy using computer modeling. (Contains 12 references.) (ASK)

  18. Hydrogen storage in fragmented carbon nanotubes: 1H NMR

    NASA Astrophysics Data System (ADS)

    Schmid, M.; Krämer, S.; Mehring, M.; Roth, S.; Haluska, M.; Bernier, P.

    2001-11-01

    We report 1H Nuclear Magnetic Resonance (NMR) studies on single walled carbon nanotubes, ball milled under hydrogen atmosphere. We have measured field and temperature dependence of proton spectra, linewidth and spin-lattice relaxation rates (T1-1). The results are interpreted by applying a quantitative model for 1H linewidth and spin-lattice relaxation rates induced by remanent dilute paramagnetic impurities. By using a calibration method with a reference sample we were able to quantify the hydrogen content.

  19. Comparison of (31)P saturation and inversion magnetization transfer in human liver and skeletal muscle using a clinical MR system and surface coils.

    PubMed

    Buehler, Tania; Kreis, Roland; Boesch, Chris

    2015-02-01

    (31)P MRS magnetization transfer ((31)P-MT) experiments allow the estimation of exchange rates of biochemical reactions, such as the creatine kinase equilibrium and adenosine triphosphate (ATP) synthesis. Although various (31)P-MT methods have been successfully used on isolated organs or animals, their application on humans in clinical scanners poses specific challenges. This study compared two major (31)P-MT methods on a clinical MR system using heteronuclear surface coils. Although saturation transfer (ST) is the most commonly used (31)P-MT method, sequences such as inversion transfer (IT) with short pulses might be better suited for the specific hardware and software limitations of a clinical scanner. In addition, small NMR-undetectable metabolite pools can transfer MT to NMR-visible pools during long saturation pulses, which is prevented with short pulses. (31)P-MT sequences were adapted for limited pulse length, for heteronuclear transmit-receive surface coils with inhomogeneous B1 , for the need for volume selection and for the inherently low signal-to-noise ratio (SNR) on a clinical 3-T MR system. The ST and IT sequences were applied to skeletal muscle and liver in 10 healthy volunteers. Monte-Carlo simulations were used to evaluate the behavior of the IT measurements with increasing imperfections. In skeletal muscle of the thigh, ATP synthesis resulted in forward reaction constants (k) of 0.074 ± 0.022 s(-1) (ST) and 0.137 ± 0.042 s(-1) (IT), whereas the creatine kinase reaction yielded 0.459 ± 0.089 s(-1) (IT). In the liver, ATP synthesis resulted in k = 0.267 ± 0.106 s(-1) (ST), whereas the IT experiment yielded no consistent results. ST results were close to literature values; however, the IT results were either much larger than the corresponding ST values and/or were widely scattered. To summarize, ST and IT experiments can both be implemented on a clinical body scanner with heteronuclear transmit-receive surface coils; however, ST results are

  20. Syntheses, structures, and 1H, 13C{1H} and 119Sn{1H} NMR chemical shifts of a family of trimethyltin alkoxide, amide, halide and cyclopentadienyl compounds

    DOE PAGES

    Lichtscheidl, Alejandro G.; Janicke, Michael T.; Scott, Brian L.; ...

    2015-08-21

    The synthesis and full characterization, including Nuclear Magnetic Resonance (NMR) data (1H, 13C{1H} and 119Sn{1H}), for a series of Me3SnX (X = O-2,6-tBu2C6H3 (1), (Me3Sn)N(2,6-iPr2C6H3) (3), NH-2,4,6-tBu3C6H2 (4), N(SiMe3)2 (5), NEt2, C5Me5 (6), Cl, Br, I, and SnMe3) compounds in benzene-d6, toluene-d8, dichloromethane-d2, chloroform-d1, acetonitrile-d3, and tetrahydrofuran-d8 are reported. The X-ray crystal structures of Me3Sn(O-2,6-tBu2C6H3) (1), Me3Sn(O-2,6-iPr2C6H3) (2), and (Me3Sn)(NH-2,4,6-tBu3C6H2) (4) are also presented. As a result, these compiled data complement existing literature data and ease the characterization of these compounds by routine NMR experiments.

  1. Following Metabolism in Living Microorganisms by Hyperpolarized (1)H NMR.

    PubMed

    Dzien, Piotr; Fages, Anne; Jona, Ghil; Brindle, Kevin M; Schwaiger, Markus; Frydman, Lucio

    2016-09-21

    Dissolution dynamic nuclear polarization (dDNP) is used to enhance the sensitivity of nuclear magnetic resonance (NMR), enabling monitoring of metabolism and specific enzymatic reactions in vivo. dDNP involves rapid sample dissolution and transfer to a spectrometer/scanner for subsequent signal detection. So far, most biologically oriented dDNP studies have relied on hyperpolarizing long-lived nuclear spin species such as (13)C in small molecules. While advantages could also arise from observing hyperpolarized (1)H, short relaxation times limit the utility of prepolarizing this sensitive but fast relaxing nucleus. Recently, it has been reported that (1)H NMR peaks in solution-phase experiments could be hyperpolarized by spontaneous magnetization transfers from bound (13)C nuclei following dDNP. This work demonstrates the potential of this sensitivity-enhancing approach to probe the enzymatic process that could not be suitably resolved by (13)C dDNP MR. Here we measured, in microorganisms, the action of pyruvate decarboxylase (PDC) and pyruvate formate lyase (PFL)-enzymes that catalyze the decarboxylation of pyruvate to form acetaldehyde and formate, respectively. While (13)C NMR did not possess the resolution to distinguish the starting pyruvate precursor from the carbonyl resonances in the resulting products, these processes could be monitored by (1)H NMR at 500 MHz. These observations were possible in both yeast and bacteria in minute-long kinetic measurements where the hyperpolarized (13)C enhanced, via (13)C → (1)H cross-relaxation, the signals of protons binding to the (13)C over the course of enzymatic reactions. In addition to these spontaneous heteronuclear enhancement experiments, single-shot acquisitions based on J-driven (13)C → (1)H polarization transfers were also carried out. These resulted in higher signal enhancements of the (1)H resonances but were not suitable for multishot kinetic studies. The potential of these (1)H-based approaches for

  2. Ionization behavior of polyphosphoinositides determined via the preparation of pH titration curves using solid-state 31P NMR.

    PubMed

    Graber, Zachary T; Kooijman, Edgar E

    2013-01-01

    Detailed knowledge of the degree of ionization of lipid titratable groups is important for the evaluation of protein-lipid and lipid-lipid interactions. The degree of ionization is commonly evaluated by acid-base titration, but for lipids localized in a multicomponent membrane interface this is not a suitable technique. For phosphomonoester-containing lipids such as the polyphosphoinositides, phosphatidic acid, and ceramide-1-phosphate, this is more conveniently accomplished by (31)P NMR. Here, we describe a solid-state (31)P NMR procedure to construct pH titration curves to determine the degree of ionization of phosphomonoester groups in polyphosphoinositides. This procedure can also be used, with suitable sample preparation conditions, for other important signaling lipids. Access to a solid-state, i.e., magic angle spinning, capable NMR spectrometer is assumed. The procedures described here are valid for a Bruker instrument, but can be adapted for other spectrometers as needed.

  3. 31P NMR spectroscopy in the quality control and authentication of extra-virgin olive oil: a review of recent progress.

    PubMed

    Dais, Photis; Spyros, Apostolos

    2007-05-01

    This review is a brief account on the application of a novel methodology to the quality control and authentication of extra-virgin olive oil. This methodology is based on the derivatization of the labile hydrogens of functional groups, such as hydroxyl and carboxyl groups, of olive oil constituents with the phosphorus reagent 2-chloro-4,4,5,5-tetramethyldioxaphospholane, and the use of the (31)P chemical shifts to identify the phosphitylated compounds. Various experimental aspects such as pertinent instrumentation, sample preparation, acquisition parameters and properties of the phosphorus reagent are reviewed. The strategy to assign the (31)P signals of the phosphitylated model compounds and olive oil constituents by employing 1D and 2D NMR experiments is presented. Finally, the capability of this technique to assess the quality and the genuineness of extra-virgin olive oil and to detect fraud is discussed.

  4. A compilation of information on the {sup 31}P(p,{alpha}){sup 28}Si reaction and properties of excited levels in the compound nucleus {sup 32}S

    SciTech Connect

    Miller, R.E.; Smith, D.L.

    1997-11-01

    This report documents a survey of the literature, and provides a compilation of data contained therein, for the {sup 31}P(p,{alpha}){sup 28}Si reaction. Attention is paid here to resonance states in the compound-nuclear system {sup 32}S formed by {sup 31}P + p, with emphasis on the alpha-particle decay channels, {sup 28}Si + {alpha} which populate specific levels in {sup 28}Si. The energy region near the proton separation energy for {sup 32}S is especially important in this context for applications in nuclear astrophysics. Properties of the excited states in {sup 28}Si are also considered. Summaries of all the located references are provided and numerical data contained in them are compiled in EXFOR format where applicable.

  5. Treatment of glycogenosys type V (McArdle disease) with creatine and ketogenic diet with clinical scores and with 31P-MRS on working leg muscle.

    PubMed

    Vorgerd, M; Zange, J

    2007-07-01

    McArdle's disease is caused by genetic defects of the muscle-specific isozyme of glycogen phosphorylase, which block ATP formation from glycogen in skeletal muscle. Creatine supplementation and ketogenic diet have been tested as potential supplements for muscle energy metabolism which may improve muscle symptomatic. Outcome measures were clinical scores describing muscle symptomatic and parameters derived from 31P-MRS examinations on working muscle. In two placebo controlled cross-over studies low dose creatine showed beneficial effects on muscle symptoms and performance whereas high dose creatine distinctly worsened muscle symptomatic in patients. In both studies, however, the absence of an elevation in phosphocreatine indicated the absence of a creatine uptake by the muscle fibre. The effects of creatine on muscle symptomatic may be independent from energy metabolism in muscle. In a case study, ketogenic diet improved muscle symptomatic and performance. However, these effects again did not result in 31P-MRS visible changes in muscle energy metabolism.

  6. Glycerophosphocholine and Glycerophosphoethanolamine Are Not the Main Sources of the In Vivo (31)P MRS Phosphodiester Signals from Healthy Fibroglandular Breast Tissue at 7 T.

    PubMed

    van der Kemp, Wybe J M; Stehouwer, Bertine L; Runge, Jurgen H; Wijnen, Jannie P; Nederveen, Aart J; Luijten, Peter R; Klomp, Dennis W J

    2016-01-01

    The identification of the phosphodiester (PDE) (31)P MR signals in the healthy human breast at ultra-high field. In vivo (31)P MRS measurements at 7 T of the PDE signals in the breast were performed investigating the chemical shifts, the transverse- and the longitudinal relaxation times. Chemical shifts and transverse relaxation times were compared with non-ambiguous PDE signals from the liver. The chemical shifts of the PDE signals are shifted -0.5 ppm with respect to glycerophosphocholine (GPC) and glycerophosphoethanolamine (GPE), and the transverse and longitudinal relaxation times for these signals are a factor 3 to 4 shorter than expected for aqueous GPC and GPE. The available experimental evidence suggests that GPC and GPE are not the main source of the PDE signals measured in fibroglandular breast tissue at 7 T. These signals may predominantly originate from mobile phospholipids.

  7. Electron spray ionization mass spectrometry and 2D 31P NMR for monitoring 18O/16O isotope exchange and turnover rates of metabolic oligophosphates

    PubMed Central

    Nemutlu, Emirhan; Juranic, Nenad; Zhang, Song; Ward, Lawrence E.; Dutta, Tumpa; Nair, K. Sreekumaran; Terzic, Andre; Macura, Slobodan; Dzeja, Petras P.

    2012-01-01

    A new method was here developed for determination of 18O labeling ratios in metabolic oligophosphates, such as ATP, at different phosphoryl moieties (α-, β-, and γ-ATP) using sensitive and rapid electrospray ionization mass spectrometry (ESI-MS). The ESI-MS based method for monitoring of 18O/16O exchange was validated with GC-MS and 2D 31P NMR correlation spectroscopy, the current standard methods in labeling studies. Significant correlation was found between isotopomer selective 2D 31P NMR spectroscopy and isotopomer less selective ESI-MS method. Results demonstrate that ESI-MS provides a robust analytical platform for simultaneous determination of levels, 18O-labeling kinetics and turnover rates of α-, β-, and γ-phosphoryls in ATP molecule. Such method is advantageous for large scale dynamic phosphometabolomic profiling of metabolic networks and acquiring information on the status of probed cellular energetic system. PMID:22427058

  8. Electron spray ionization mass spectrometry and 2D 31P NMR for monitoring 18O/16O isotope exchange and turnover rates of metabolic oligophosphates.

    PubMed

    Nemutlu, Emirhan; Juranic, Nenad; Zhang, Song; Ward, Lawrence E; Dutta, Tumpa; Nair, K Sreekumaran; Terzic, Andre; Macura, Slobodan; Dzeja, Petras P

    2012-05-01

    A new method was here developed for the determination of (18)O-labeling ratios in metabolic oligophosphates, such as ATP, at different phosphoryl moieties (α-, β-, and γ-ATP) using sensitive and rapid electrospray ionization mass spectrometry (ESI-MS). The ESI-MS-based method for monitoring of (18)O/(16)O exchange was validated with gas chromatography-mass spectrometry and 2D (31)P NMR correlation spectroscopy, the current standard methods in labeling studies. Significant correlation was found between isotopomer selective 2D (31)P NMR spectroscopy and isotopomer less selective ESI-MS method. Results demonstrate that ESI-MS provides a robust analytical platform for simultaneous determination of levels, (18)O-labeling kinetics and turnover rates of α-, β-, and γ-phosphoryls in ATP molecule. Such method is advantageous for large scale dynamic phosphometabolomic profiling of metabolic networks and acquiring information on the status of probed cellular energetic system.

  9. Muscle metabolism and activation heterogeneity by combined 31P chemical shift and T2 imaging, and pulmonary O2 uptake during incremental knee-extensor exercise.

    PubMed

    Cannon, Daniel T; Howe, Franklyn A; Whipp, Brian J; Ward, Susan A; McIntyre, Dominick J; Ladroue, Christophe; Griffiths, John R; Kemp, Graham J; Rossiter, Harry B

    2013-09-01

    The integration of skeletal muscle substrate depletion, metabolite accumulation, and fatigue during large muscle-mass exercise is not well understood. Measurement of intramuscular energy store degradation and metabolite accumulation is confounded by muscle heterogeneity. Therefore, to characterize regional metabolic distribution in the locomotor muscles, we combined 31P magnetic resonance spectroscopy, chemical shift imaging, and T2-weighted imaging with pulmonary oxygen uptake during bilateral knee-extension exercise to intolerance. Six men completed incremental tests for the following: (1) unlocalized 31P magnetic resonance spectroscopy; and (2) spatial determination of 31P metabolism and activation. The relationship of pulmonary oxygen uptake to whole quadriceps phosphocreatine concentration ([PCr]) was inversely linear, and three of four knee-extensor muscles showed activation as assessed by change in T2. The largest changes in [PCr], [inorganic phosphate] ([Pi]) and pH occurred in rectus femoris, but no voxel (72 cm3) showed complete PCr depletion at exercise cessation. The most metabolically active voxel reached 11 ± 9 mM [PCr] (resting, 29 ± 1 mM), 23 ± 11 mM [Pi] (resting, 7 ± 1 mM), and a pH of 6.64 ± 0.29 (resting, 7.08 ± 0.03). However, the distribution of 31P metabolites and pH varied widely between voxels, and the intervoxel coefficient of variation increased between rest (∼10%) and exercise intolerance (∼30-60%). Therefore, the limit of tolerance was attained with wide heterogeneity in substrate depletion and fatigue-related metabolite accumulation, with extreme metabolic perturbation isolated to only a small volume of active muscle (<5%). Regional intramuscular disturbances are thus likely an important requisite for exercise intolerance. How these signals integrate to limit muscle power production, while regional "recruitable muscle" energy stores are presumably still available, remains uncertain.

  10. Muscle metabolism and activation heterogeneity by combined 31P chemical shift and T2 imaging, and pulmonary O2 uptake during incremental knee-extensor exercise

    PubMed Central

    Cannon, Daniel T.; Howe, Franklyn A.; Whipp, Brian J.; Ward, Susan A.; McIntyre, Dominick J.; Ladroue, Christophe; Griffiths, John R.; Kemp, Graham J.

    2013-01-01

    The integration of skeletal muscle substrate depletion, metabolite accumulation, and fatigue during large muscle-mass exercise is not well understood. Measurement of intramuscular energy store degradation and metabolite accumulation is confounded by muscle heterogeneity. Therefore, to characterize regional metabolic distribution in the locomotor muscles, we combined 31P magnetic resonance spectroscopy, chemical shift imaging, and T2-weighted imaging with pulmonary oxygen uptake during bilateral knee-extension exercise to intolerance. Six men completed incremental tests for the following: 1) unlocalized 31P magnetic resonance spectroscopy; and 2) spatial determination of 31P metabolism and activation. The relationship of pulmonary oxygen uptake to whole quadriceps phosphocreatine concentration ([PCr]) was inversely linear, and three of four knee-extensor muscles showed activation as assessed by change in T2. The largest changes in [PCr], [inorganic phosphate] ([Pi]) and pH occurred in rectus femoris, but no voxel (72 cm3) showed complete PCr depletion at exercise cessation. The most metabolically active voxel reached 11 ± 9 mM [PCr] (resting, 29 ± 1 mM), 23 ± 11 mM [Pi] (resting, 7 ± 1 mM), and a pH of 6.64 ± 0.29 (resting, 7.08 ± 0.03). However, the distribution of 31P metabolites and pH varied widely between voxels, and the intervoxel coefficient of variation increased between rest (∼10%) and exercise intolerance (∼30–60%). Therefore, the limit of tolerance was attained with wide heterogeneity in substrate depletion and fatigue-related metabolite accumulation, with extreme metabolic perturbation isolated to only a small volume of active muscle (<5%). Regional intramuscular disturbances are thus likely an important requisite for exercise intolerance. How these signals integrate to limit muscle power production, while regional “recruitable muscle” energy stores are presumably still available, remains uncertain. PMID:23813534

  11. Analysis of the urinary excretion of ifosfamide and its N-dechloroethylated metabolites in children using 31P-NMR spectroscopy.

    PubMed

    Misiura, Konrad; Zubowska, Małgorzata; Zielińska, Elzbieta

    2003-01-01

    Amounts of ifosfamide (CAS 3778-73-2) and its N-dechloroethylated metabolites excreted in the urine were measured using 31P-NMR spectroscopy in 26 cancer children treated with this drug. Strong inter-patient variation in levels of these compounds were found. These differences were independent from patients age, body surface area, and sex, the dose of the drug, suggesting genetic base of observed variations in ifosfamide metabolism.

  12. Development of a CP 31P NMR Broadline Simulation Methodology for Studying the Interactions of Antihypertensive AT1 Antagonist Losartan with Phospholipid Bilayers

    PubMed Central

    Fotakis, Charalambos; Christodouleas, Dionisios; Chatzigeorgiou, Petros; Zervou, Maria; Benetis, Nikolas-Ploutarch; Viras, Kyriakos; Mavromoustakos, Thomas

    2009-01-01

    A cross-polarization (CP) 31P NMR broadline simulation methodology was developed for studying the effects of drugs in phospholipids bilayers. Based on seven-parameter fittings, this methodology provided information concerning the conformational changes and dynamics effects of losartan in the polar region of the dipalmitoylphosphatidylcholine bilayers. The test molecule for this study was losartan, an antihypertensive drug known to exert its effect on AT1 transmembrane receptors. The results were complemented and compared with those of differential scanning calorimetry, solid-state 13C NMR spectroscopy, Raman spectroscopy, and electron spin resonance. More specifically, these physical chemical methodologies indicated that the amphipathic losartan molecule interacts with the hydrophilic-head zone of the lipid bilayers. The CP 31P NMR broadline simulations showed that the lipid molecules in the bilayers containing losartan displayed greater collective tilt compared to the tilt displayed by the load-free bilayers, indicating improved packing. The Raman results displayed a decrease in the trans/gauche ratio and increased intermolecular interactions of the acyl chains in the liquid crystalline phase. Additional evidence, suggesting that losartan possibly anchors in the realm of the headgroup, was derived from upfield shift of the average chemical shift σiso of the 31P signal in the presence of losartan and from shift of the observed peak at 715 cm−1 attributed to C-N stretching in the Raman spectra. PMID:19289049

  13. Detailed Chemical Composition of Condensed Tannins via Quantitative (31)P NMR and HSQC Analyses: Acacia catechu, Schinopsis balansae, and Acacia mearnsii.

    PubMed

    Crestini, Claudia; Lange, Heiko; Bianchetti, Giulia

    2016-09-23

    The chemical composition of Acacia catechu, Schinopsis balansae, and Acacia mearnsii proanthocyanidins has been determined using a novel analytical approach that rests on the concerted use of quantitative (31)P NMR and two-dimensional heteronuclear NMR spectroscopy. This approach has offered significant detailed information regarding the structure and purity of these complex and often elusive proanthocyanidins. More specifically, rings A, B, and C of their flavan-3-ol units show well-defined and resolved absorbance regions in both the quantitative (31)P NMR and HSQC spectra. By integrating each of these regions in the (31)P NMR spectra, it is possible to identify the oxygenation patterns of the flavan-3-ol units. At the same time it is possible to acquire a fingerprint of the proanthocyanidin sample and evaluate its purity via the HSQC information. This analytical approach is suitable for both the purified natural product proanthocyanidins and their commercial analogues. Overall, this effort demonstrates the power of the concerted use of these two NMR techniques for the structural elucidation of natural products containing labile hydroxy protons and a carbon framework that can be traced out via HSQC.

  14. Effects of pH and cholesterol on DMPA membranes: a solid state 2H- and 31P-NMR study.

    PubMed Central

    Pott, T; Maillet, J C; Dufourc, E J

    1995-01-01

    The effect of pH and cholesterol on the dimyristoylphosphatidic acid (DMPA) model membrane system has been investigated by solid state 2H- and 31P-NMR. It has been shown that each of the three protonation states of the DMPA molecule corresponds to a 31P-NMR powder pattern with characteristic delta sigma values; this implies additionally that the proton exchange on the membrane surface is slow on the NMR time scale (millisecond range). Under these conditions, the 2H-labeled lipid chains sense only one magnetic environment, indicating that the three spectra detected by 31P-NMR are related to charge-dependent local dynamics or orientations of the phosphate headgroup or both. Chain ordering in the fluid phase is also found to depend weakly on the charge at the interface. In addition, it has also been found that the first pK of the DMPA membrane is modified by changes in the lipid lateral packing (gel or fluid phases or in the presence of cholesterol) in contrast to the second pK. The incorporation of 30 mol% cholesterol affects the phosphatidic acid bilayer in a way similar to what has been reported for phosphatidylcholine/cholesterol membranes, but to an extent comparable to 10-20 mol % sterol in phosphatidylcholines. However, the orientation and molecular order parameter of cholesterol in DMPA are similar to those found in dimyristoylphosphatidylcholine. PMID:8580333

  15. Effects of pH and cholesterol on DMPA membranes: a solid state 2H- and 31P-NMR study.

    PubMed

    Pott, T; Maillet, J C; Dufourc, E J

    1995-11-01

    The effect of pH and cholesterol on the dimyristoylphosphatidic acid (DMPA) model membrane system has been investigated by solid state 2H- and 31P-NMR. It has been shown that each of the three protonation states of the DMPA molecule corresponds to a 31P-NMR powder pattern with characteristic delta sigma values; this implies additionally that the proton exchange on the membrane surface is slow on the NMR time scale (millisecond range). Under these conditions, the 2H-labeled lipid chains sense only one magnetic environment, indicating that the three spectra detected by 31P-NMR are related to charge-dependent local dynamics or orientations of the phosphate headgroup or both. Chain ordering in the fluid phase is also found to depend weakly on the charge at the interface. In addition, it has also been found that the first pK of the DMPA membrane is modified by changes in the lipid lateral packing (gel or fluid phases or in the presence of cholesterol) in contrast to the second pK. The incorporation of 30 mol% cholesterol affects the phosphatidic acid bilayer in a way similar to what has been reported for phosphatidylcholine/cholesterol membranes, but to an extent comparable to 10-20 mol % sterol in phosphatidylcholines. However, the orientation and molecular order parameter of cholesterol in DMPA are similar to those found in dimyristoylphosphatidylcholine.

  16. Differently saturated fatty acids can be differentiated by 31P NMR subsequent to derivatization with 2-chloro-4,4,5,5-tetramethyldioxaphospholane: a cautionary note.

    PubMed

    Eibisch, Mandy; Riemer, Thomas; Fuchs, Beate; Schiller, Jürgen

    2013-03-20

    The analysis of free fatty acid (FFA) mixtures is a very important but, even nowadays, challenging task. This particularly applies as the so far most commonly used technique-gas chromatography/mass spectrometry (GC/MS)-is tedious and time-consuming. It has been convincingly shown ( Spyros, A.; Dais, P. J. Agric. Food Chem. 2000, 48, 802 - 5) that FFA may be analyzed by (31)P NMR subsequent to derivatization with 2-chloro-4,4,5,5-tetramethyldioxaphospholane (CTDP). However, it was also indicated that differently unsaturated FFAs result in the same (31)P NMR chemical shift and cannot be differentiated. Therefore, only the overall fatty acid content of a sample can be determined by the CTDP assay. In contrast, we will show here by using high-field NMR (600 MHz spectrometer, i.e., 242.884 MHz for (31)P) that the CTDP assay may be used to differentiate FFAs that have pronounced differences in their double bond contents: saturated fatty acids (16:0), moderately unsaturated (18:1, 18:2), highly unsaturated (20:4), and extremely unsaturated fatty acids (22:6) result in slightly different chemical shifts. The same applies for oxidized fatty acids. Finally, it will also be shown that the CTDP derivatization products decompose in a time-dependent manner. Therefore, all investigations must adhere to a strict time regime.

  17. A Chinese benign adult familial myoclonic epilepsy pedigree suggesting linkage to chromosome 5p15.31-p15.1.

    PubMed

    Li, Jia; Hu, Xinyu; Chen, Qiuhui; Zhang, Yizhi; Zhang, Ying; Hu, Guohua

    2014-07-01

    Benign adult familial myoclonic epilepsy (BAFME) has been mapped to chromosome 8q23.3-q24.1, 2p11.1-q12.1, 5p15.31-p15.1, and 3q26.32-3q28, in Japanese, Italian, Thai, and French pedigrees, respectively. Recently, we investigated a Chinese BAFME family. Clinical and electrophysiological studies revealed that nine individuals were affected with BAFME. We aimed to establish the causative gene for this pedigree. We genotyped 17 microsatellite markers covering the four previously identified chromosome regions and performed linkage analyses. The linkage analysis data showed that the LOD score was 2.80 for D5S486 at no recombination. This suggested linkage to 5p15.31-p15.1 and excluded linkage to the other three loci (LOD score <0 at no recombination). Our study suggests that the causative gene responsible for BAFME in the Chinese pedigree may be located on chromosome 5p15.31-p15.1.

  18. Insights on the Interactions of Synthetic Amphipathic Peptides with Model Membranes as Revealed by 31P and 2H Solid-State NMR and Infrared Spectroscopies

    PubMed Central

    Ouellet, Marise; Bernard, Geneviève; Voyer, Normand; Auger, Michèle

    2006-01-01

    We studied the interaction between synthetic amphipathic peptides and model membranes by solid-state NMR and infrared spectroscopies. Peptides with 14 and 21 amino acids composed of leucines and phenylalanines modified by the addition of crown ethers were synthesized. The 14-mer and 21-mer peptides both possess a helical amphipathic structure. To shed light on their membrane interaction, 31P and 2H solid-state NMR experiments were performed on both peptides in interaction with dimyristoylphosphatidylcholine vesicles in the absence and presence of cholesterol, dimyristoylphosphatidylglycerol vesicles, and oriented bicelles. 31P NMR experiments on multilamellar vesicles reveal that the dynamics and/or orientation of the polar headgroups are weakly yet markedly affected by the presence of the peptides, whereas 31P NMR experiments on bicelles indicate no significant changes in the morphology and orientation of the bicelles. On the other hand, 2H NMR experiments on vesicles reveal that the acyl chain order is affected differently depending on the membrane lipidic composition and on the peptide hydrophobic length. Finally, infrared spectroscopy was used to study the interfacial region of the bilayer. Based on these studies, mechanisms of membrane perturbation are proposed for the 14-mer and 21-mer peptides in interaction with model membranes depending on the bilayer composition and peptide length. PMID:16533836

  19. {sup 31}P NMR study of the complexation of TBP with lanthanides and actinides in solution and in a clay matrix

    SciTech Connect

    Hartzell, C.J.

    1994-07-24

    Goal was to use NMR to study TBP/lanthanide complexes in the interlayer or on edge sites of clays. Work in this laboratory yielded details of the complexation of Eu(NO{sub 3}){sub 3} and Pr(NO{sub 3}){sub 3} with TBP in hexane solution; this information is crucial to interpretation of results of NMR studies of the complexes exchanged into clays. The solution {sup 31}P-chemical shift values were improved by repeating the studies on the lanthanide salts dissolved directly into neat TBP. NMR studies of these neat solutions of the Eu(NO{sub 3}){sub 3}{lg_bullet}3TBP-complex and the Pr(NO{sub 3}){sub 3}{lg_bullet}3TBP-complex show that the {sup 31}P chemical shift remains relatively constant for TBP: lanthanide ratios below 3: 1. At higher ratios, the chemical shift approaches that of free TBP, indicating rapid exchange of TBP between the free and complexed state. Exchange of these complexes into the clay hectorite yielded discrete {sup 31}P-NMR signals for the Eu{lg_bullet}TBP complex at -190 ppm and free TBP at -6 ppm. Adsorption of the Pr{lg_bullet}TBP complex yielded broad signals at 76 ppm for the complex and -6 ppm for free TBP. There was no evidence of exchange between the incorporated complex and the free TBP.

  20. A Solid-State Study of a Novel 31P Spin Pair Using Magic-Angle-Spinning Nuclear Magnetic Resonance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Challoner, R.; Mcdowell, C. A.; Yoshifuji, M.; Toyota, K.; Tossell, J. A.

    The present investigation concerns the solid-state nuclear magnetic resonance spectroscopy of the 31P spin pair in the novel three-membered heterocyclic compound 3-(dichloromethylene)- trans-1,2-bis( 2,4,6-tri- tert-butylphenyl)- 1,2-diphosphirane using the magic-angle-spinning (MAS) technique. The homogeneous 31P lineshapes are analyzed to extract the principal components of the shielding tensors using the Maricq and Waugh description of homonuclear spin-pair systems by average-Hamiltonian theory, modified to encompass the n = 0 rotational resonance situation. The experimental values of the shielding-tensor components are compared with those obtained from ab initio calculations performed on the model molecule P 2C 2H 4 to aid further the interpretation of the 31P MAS NMR spectrum of the chloromethylene-diphosphirane. The magnitudes and orientations of calculated shielding-tensor components of the model compound methylene-diphosphirane P 2C 2H 4 are compared with those for the phosphorus spin pair in the molecular environments of P 2, P 2H 2, and P 2H 4. The electronic structures and bonding in all of those molecular species are discussed.

  1. Localized double-quantum-filtered 1H NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Thomas, M. A.; Hetherington, H. P.; Meyerhoff, D. J.; Twieg, D. B.

    The image-guided in vivo spectroscopic (ISIS) pulse sequence has been combined with a double-quantum-filter scheme in order to obtain localized and water-suppressed 1H NMR spectra of J-coupled metabolites. The coherence-transfer efficiency associated with the DQ filter for AX and A 3X spin systems is described. Phantom results of carnosine, alanine, and ethanol in aqueous solution are presented. For comparison, the 1H NMR spectrum of alanine in aqueous solution with the binomial (1331, 2662) spin-echo sequence is also shown.

  2. Quantitative analysis of norfloxacin by 1H NMR and HPLC.

    PubMed

    Frackowiak, Anita; Kokot, Zenon J

    2012-01-01

    1H NMR and developed previously HPLC methods were applied to quantitative determination of norfloxacin in veterinary solution form for pigeon. Changes in concentration can lead to significant changes in the 1H chemical shifts of non-exchangeable aromatic protons as a result of extensive self-association phenomena. This chemical shift variation of protons was analyzed and applied in the quantitative determination of norfloxacin. The method is simple, rapid, precise and accurate, and can be used for quality control of this drug.

  3. Repeatability of (31) P MRSI in the human brain at 7 T with and without the nuclear Overhauser effect.

    PubMed

    Lagemaat, Miriam W; van de Bank, Bart L; Sati, Pascal; Li, Shizhe; Maas, Marnix C; Scheenen, Tom W J

    2016-03-01

    An often-employed strategy to enhance signals in (31) P MRS is the generation of the nuclear Overhauser effect (NOE) by saturation of the water resonance. However, NOE allegedly increases the variability of the (31) P data, because variation is reported in NOE enhancements. This would negate the signal-to-noise (SNR) gain it generates. We hypothesized that the variation in NOE enhancement values is not caused by the variability in NOE itself, but is attributable to measurement uncertainties in the values used to calculate the enhancement. If true, the expected increase in SNR with NOE would improve the repeatability of (31) P MRS measurements. To verify this hypothesis, a repeatability study of native and NOE-enhanced (31) P MRSI was performed in the brains of seven healthy volunteers at 7 T. The repeatability coefficient (RC) and the coefficient of variation in repeated measurements (CoVrepeat ) were determined for each method, and the 95% limits of agreement (LoAs) between native and NOE-enhanced signals were calculated. The variation between the methods, defined by the LoA, is at least as great as that predicted by the RC of each method. The sources of variation in NOE enhancements were determined using variance component analysis. In the seven metabolites with a positive NOE enhancement (nine metabolite resonances assessed), CoVrepeat improved, on average, by 15%. The LoAs could be explained by the RCs of the individual methods for the majority of the metabolites, generally confirming our hypothesis. Variation in NOE enhancement was mainly attributable to the factor repeat, but between-voxel effects were also present for phosphoethanolamine and (glycero)phosphocholine. CoVrepeat and fitting error were strongly correlated and improved with positive NOE. Our findings generally indicate that NOE enhances the signal of metabolites, improving the repeatability of metabolite measurements. Additional variability as a result of NOE was minimal. These findings

  4. Detection of cerebral NAD(+) by in vivo (1)H NMR spectroscopy.

    PubMed

    de Graaf, Robin A; Behar, Kevin L

    2014-07-01

    Nicotinamide adenine dinucleotide (NAD(+)) plays a central role in cellular metabolism both as a coenzyme for electron-transfer enzymes as well as a substrate for a wide range of metabolic pathways. In the current study NAD(+) was detected on rat brain in vivo at 11.7T by 3D localized (1)H MRS of the NAD(+) nicotinamide protons in the 8.7-9.5 ppm spectral region. Avoiding water perturbation was critical to the detection of NAD(+) as strong, possibly indirect cross-relaxation between NAD(+) and water would lead to a several-fold reduction of the NAD(+) intensity in the presence of water suppression. Water perturbation was minimized through the use of localization by adiabatic spin-echo refocusing (LASER) in combination with frequency-selective excitation. The NAD(+) concentration in the rat cerebral cortex was determined at 296 ± 28 μm, which is in good agreement with recently published (31) P NMR-based results as well as results from brain extracts in vitro (355 ± 34 μm). The T1 relaxation time constants of the NAD(+) nicotinamide protons as measured by inversion recovery were 280 ± 65 and 1136 ± 122 ms in the absence and presence of water inversion, respectively. This confirms the strong interaction between NAD(+) nicotinamide and water protons as observed during water suppression. The T2 relaxation time constants of the NAD(+) nicotinamide protons were determined at 60 ± 13 ms after confounding effects of scalar coupling evolution were taken into account. The simplicity of the MR sequence together with the robustness of NAD(+) signal detection and quantification makes the presented method a convenient choice for studies on NAD(+) metabolism and function. As the method does not critically rely on magnetic field homogeneity and spectral resolution it should find immediate applications in rodents and humans even at lower magnetic fields.

  5. Nuclear receptor NR1H3 in familial multiple sclerosis

    PubMed Central

    Wang, Zhe; Sadovnick, A. Dessa; Traboulsee, Anthony L.; Ross, Jay P.; Bernales, Cecily Q.; Encarnacion, Mary; Yee, Irene M.; de Lemos, Madonna; Greenwood, Talitha; Lee, Joshua D.; Wright, Galen; Ross, Colin J.; Zhang, Si; Song, Weihong; Vilariño-Güell, Carles

    2016-01-01

    SUMMARY Multiple sclerosis (MS) is an inflammatory disease characterized by myelin loss and neuronal dysfunction. Despite the aggregation observed in some families, pathogenic mutations have remained elusive. In this study we describe the identification of NR1H3 p.Arg415Gln in seven MS patients from two multi-incident families presenting severe and progressive disease, with an average age at onset of 34 years. Additionally, association analysis of common variants in NR1H3 identified rs2279238 conferring a 1.35-fold increased risk of developing progressive MS. The p.Arg415Gln position is highly conserved in orthologs and paralogs, and disrupts NR1H3 heterodimerization and transcriptional activation of target genes. Protein expression analysis revealed that mutant NR1H3 (LXRA) alters gene expression profiles, suggesting a disruption in transcriptional regulation as one of the mechanisms underlying MS pathogenesis. Our study indicates that pharmacological activation of LXRA or its targets may lead to effective treatments for the highly debilitating and currently untreatable progressive phase of MS. PMID:27253448

  6. Applications of 1H-NMR to Biodiesel Research

    USDA-ARS?s Scientific Manuscript database

    Biodiesel is an alternative diesel fuel derived from vegetable oils, animal fats, or used cooking oils. It is produced by reacting these materials with an alcohol in the presence of a catalyst to give the corresponding mono-alkyl esters. 1H-NMR is a routine analytical method that has been used for...

  7. Complete 1H and 13C spectral assignment of floridoside.

    PubMed

    Simon-Colin, Christelle; Kervarec, Nelly; Pichon, Roger; Deslandes, Eric

    2002-02-11

    Floridoside (2-O-alpha-D-galactopyranosylglycerol) was extracted from the red marine alga Rhodymenia palmata, and purified by ion-exchange chromatography: 1D and 2D NMR spectroscopy experiments were used to unambiguously assign the complete 1H and 13C spectra.

  8. 1H Magnetic Resonance Spectroscopy of live human sperm.

    PubMed

    Reynolds, S; Calvert, S J; Paley, M N; Pacey, A A

    2017-07-01

    Can 1H Magnetic Resonance Spectroscopy (MRS) be used to obtain information about the molecules and metabolites in live human spermatozoa? Percoll-based density gradient centrifugation (DGC) followed by a further two washing steps, yielded enough sperm with minimal contamination (<0.01%) from seminal fluid to permit effective MRS which detected significant differences (P < 0.05) in the choline/glycerophosphocholine (GPC), lipid and lactate regions of the 1H MRS spectrum between sperm in the pellet and those from the 40%/80% interface. Current methods to examine sperm are either limited in their value (e.g. semen analysis) or are destructive (e.g. immunohistochemistry, sperm DNA testing). A few studies have previously used MRS to examine sperm, but these have either looked at seminal plasma from men with different ejaculate qualities or at the molecules present in pooled samples of lyophilized sperm. Sperm suspended in phosphate buffered saline (PBS) at 37°C were examined by 1H MRS scanning using a 1H excitation-sculpting solvent suppression sequence after recovery from fresh ejaculates by one of three different methods: (i) simple centrifugation; (ii) DGC with one wash; or (iii) DGC with two washes. In the case of DGC, sperm were collected both from the pellet ('80%' sperm) and the 40/80 interface ('40%' sperm). Spectrum processing was carried out using custom Matlab scripts to determine; the degree of seminal plasma/Percoll contamination, the minimum sperm concentration for 1H MRS detection and differences between the 1H MRS spectra of '40%' and '80%' sperm. DGC with two washes minimized the 1H MRS peak intensity for both seminal plasma and Percoll/PBS solution contamination while retaining sperm specific peaks. For the MRS scanner used in this study, the minimum sperm concentration required to produce a choline/GPC 1H MRS peak greater than 3:1 signal to noise ratio (SNR) was estimated at ~3 × 106/ml. The choline/GPC and lactate/lipid regions of the 1H spectrum

  9. Brain temperature and pH measured by 1H chemical shift imaging of a thulium agent

    PubMed Central

    Coman, Daniel; Trubel, Hubert K.; Rycyna, Robert E.; Hyder, Fahmeed

    2009-01-01

    Temperature and pH are two of the most important physiological parameters and are believed to be tightly regulated because they are intricately related to energy metabolism in living organisms. Temperature and/or pH data in mammalian brain are scarce, however, mainly due to lack of precise and non-invasive methods. At 11.7T, we demonstrate that a thulium-based macrocyclic complex infused through the blood stream can be used to obtain temperature and pH maps of rat brain in vivo by 1H chemical shift imaging (CSI) of the sensor itself in conjunction with a multi-parametric model that depends on several proton resonances of the sensor. Accuracies of temperature and pH determination with the thulium sensor – which has a predominantly extracellular presence – depend on stable signals during the course of the CSI experiment as well as redundancy for temperature and pH sensitivities contained within the observed signals. The thulium-based method compared well with other methods for temperature (1H magnetic resonance spectroscopy (MRS) of N-acetyl aspartate and water; copper-constantan thermocouple wire) and pH (31P MRS of inorganic phosphate and phosphocreatine) assessment, as established by in vitro and in vivo studies. In vitro studies in phantoms with two compartments of differing pH values observed under different ambient temperature conditions generated precise temperature and pH distribution maps. In vivo studies in α-chloralose anesthetized and renal-ligated rats revealed temperature (33–34 °C) and pH (7.3–7.4) distributions in the cerebral cortex which are in agreement with observations by other methods. These results demonstrate that the thulium sensor can be used to measure temperature and pH distributions in rat brain in vivo simultaneously and accurately with 1H CSI. PMID:19130468

  10. HIST1H2AA — EDRN Public Portal

    Cancer.gov

    HIST1H2AA, a member of the histone 2A family, is a core component of the nucleosome. The nucleosome is a histone octamer containing two molecules each of H2A, H2B, H3 and H4 assembled in one H3-H4 heterotetramer and two H2A-H2B heterodimers. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template (the octamer wraps approximately 147 bp of DNA). Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. The HIST1H2AA gene is intronless and encodes a member of the histone H2A family. Transcripts from this gene contain a palindromic termination element.

  11. 1H NMR Studies of MgH2

    NASA Astrophysics Data System (ADS)

    Itoh, Yutaka; Kado, Ryoichi

    We report on 1H NMR studies of commercially available powder MgH2 exposed to air and maybe humidity, which has been believed to be a promising material for hydrogen storage. The Fourier transform of the free-induction decay of the protons indicatesd superposition of broad and narrow components in the NMR spectrum, while the Fourier transform of the 1H nuclear spin-echo reproduced the narrow component. With cooling down below room temperature, the ratio of the narrow peak to the broad spectrum decreased. The broad spectrum is associated with direct dipolar coupled protons on an inhomogeneous rigid lattice. The narrow peak is associated with interstitial protons with more inhomogeneous surroundings.

  12. 31P-magnetic resonance spectroscopy and 2H-magnetic resonance imaging studies of a panel of early-generation transplanted murine tumour models.

    PubMed Central

    Robinson, S. P.; van den Boogaart, A.; Maxwell, R. J.; Griffiths, J. R.; Hamilton, E.; Waterton, J. C.

    1998-01-01

    The objective of this study was first to determine whether three slowly growing early-generation murine transplantable tumours, the T40 fibrosarcoma, T115 mammary carcinoma and T237 lung carcinoma, exhibit patterns of energetics and blood flow during growth that are different from those of the faster growing RIF-1 fibrosarcoma. Serial measurements were made with 31P-magnetic resonance spectroscopy (MRS), relating to nutritive blood flow and 2H-magnetic resonance imaging (MRI), which is sensitive to both nutritive and large-vessel (non-nutritive) flow. All four tumour lines showed a decrease in betaNTP/Pi and pH with growth; however, each line showed a different pattern of blood flow that did not correlate with the decrease in energetics. Qualitative histological analysis strongly correlated with the 2H-MRI. Second, their response to 5 mg kg(-1) hydralazine i.v. was monitored by 31P-MRS. A marked decrease in betaNTP/Pi and pH was observed in both the RIF-1 fibrosarcoma and the third-generation T115 mammary carcinoma after hydralazine challenge. In contrast, the fourth generation T40 fibrosarcoma and T237 lung carcinoma showed no change in 31P-MRS parameters. However, a fifth-generation T237 cohort, which grew approximately three times faster than fourth-generation T237 cohorts, exhibited a significant deterioration in betaNTP/Pi and pH in response to hydralazine. These data are consistent with a decoupling between large-vessel and nutritive blood flow and indicate that early-generation transplants that have a slow growth rate and vascular tone are more appropriate models of human tumour vasculature than more rapidly growing, repeatedly transplanted tumours. Images Figure 2 PMID:9667643

  13. Gray Matter-Specific Changes in Brain Bioenergetics after Acute Sleep Deprivation: A 31P Magnetic Resonance Spectroscopy Study at 4 Tesla

    PubMed Central

    Plante, David T.; Trksak, George H.; Jensen, J. Eric; Penetar, David M.; Ravichandran, Caitlin; Riedner, Brady A.; Tartarini, Wendy L.; Dorsey, Cynthia M.; Renshaw, Perry F.; Lukas, Scott E.; Harper, David G.

    2014-01-01

    Study Objectives: A principal function of sleep may be restoration of brain energy metabolism caused by the energetic demands of wakefulness. Because energetic demands in the brain are greater in gray than white matter, this study used linear mixed-effects models to examine tissue-type specific changes in high-energy phosphates derived using 31P magnetic resonance spectroscopy (MRS) after sleep deprivation and recovery sleep. Design: Experimental laboratory study. Setting: Outpatient neuroimaging center at a private psychiatric hospital. Participants: A total of 32 MRS scans performed in eight healthy individuals (mean age 35 y; range 23-51 y). Interventions: Phosphocreatine (PCr) and β-nucleoside triphosphate (NTP) were measured using 31P MRS three dimensional-chemical shift imaging at high field (4 Tesla) after a baseline night of sleep, acute sleep deprivation, and 2 nights of recovery sleep. Novel linear mixed-effects models were constructed using spectral and tissue segmentation data to examine changes in bioenergetics in gray and white matter. Measurements and Results: PCr increased in gray matter after 2 nights of recovery sleep relative to sleep deprivation with no significant changes in white matter. Exploratory analyses also demonstrated that increases in PCr were associated with increases in electroencephalographic slow wave activity during recovery sleep. No significant changes in β-NTP were observed. Conclusions: These results demonstrate that sleep deprivation and subsequent recovery-induced changes in high-energy phosphates primarily occur in gray matter, and increases in phosphocreatine after recovery sleep may be related to sleep homeostasis. Citation: Plante DT, Trksak GH, Jensen JE, Penetar DM, Ravichandran C, Riedner BA, Tartarini WL, Dorsey CM, Renshaw PF, Lukas SE, Harper DG. Gray matter-specific changes in brain bioenergetics after acute sleep deprivation: a 31P magnetic resonance spectroscopy study at 4 Tesla. SLEEP 2014

  14. Carbon-13, sup 15 N, and sup 31 P NMR studies on 6-hydroxy-L-nicotine oxidase from Arthrobacter oxidans

    SciTech Connect

    Pust, S.; Vervoort, J.; Decker, K.; Bacher, A.; Mueller, F. )

    1989-01-24

    The interaction between the apoprotein of 6-hydroxy-L-nicotine oxidase from Arthrobacter oxidans and the prosthetic group FAD has been investigated by {sup 13}C, {sup 15}N and {sup 31}P NMR techniques. The FAD prosthetic group was selectively enriched in {sup 13}C and {sup 15}N isotopes by adding isotopically labeled riboflavin derivatives to the growth medium of riboflavin-requiring mutant cells. In the oxidized state the chemical shift of the C(7) and C(8) atoms indicates that the xylene moiety of the isoalloxazine ring is embedded in a hydrophobic environment. The binding of the competitive inhibitor, 6-hydroxy-D-nicotine, influences the resonances of the C(4a) and the N(5) atom strongly. It is suggested that these shifts are due to a strong hydrogen-bonding interaction between the N(5) atom and the inhibitor. On reduction all resonances, except those of the C(10a) and the N(1) atoms, shift upfield, indicating the increased electron density in the ring system. It can unambiguously be concluded from the chemical shift of the N(1) atom that the reduced flavin is anionic. The doublet character of the N(3) and N(5) resonances suggests that bulk water has no access to the active center. The strong downfield shift of the N(1) position indicates that this atom is embedded in a polar environment, but it does not indicate the presence of a positively charged residue. The {sup 31}P NMR spectra show that the resonances of the pyrophosphate group of the bound FAD differ slightly from those of free FAD. Besides the {sup 31}P resonances from FAD, four peaks around 0 ppm are observed that belongs to bound phosphorus residues. The residues are not located close to the isoalloxazine ring.

  15. Phosphate ions in bone: identification of a calcium-organic phosphate complex by 31P solid-state NMR spectroscopy at early stages of mineralization.

    PubMed

    Wu, Y; Ackerman, J L; Strawich, E S; Rey, C; Kim, H-M; Glimcher, M J

    2003-05-01

    Previous 31P cross-polarization and differential cross-polarization magic angle spinning (CP/MAS and DCP/MAS) solid-state NMR spectroscopy studies of native bone and of the isolated crystals of the calcified matrix synthesized by osteoblasts in cell culture identified and characterized the major PO(-3)(4) phosphate components of the mineral phase. The isotropic and anisotropic chemical shift parameters of the minor HPO(-2)(4) component in bone mineral and in mineral deposited in osteoblast cell cultures were found to differ significantly from those of brushite, octacalcium phosphate, and other synthetic calcium phosphates. However, because of in vivo and in vitro evidence that phosphoproteins may play a significant role in the nucleation of the solid mineral phase of calcium phosphate in bone and other vertebrate calcified tissues, the focus of the current solid-state 31P NMR experiments was to detect the possible presence of and characterize the phosphoryl groups of phosphoproteins in bone at the very earliest stages of bone mineralization, as well as the possible presence of calcium-phosphoprotein complexes. The present study demonstrates that by far the major phosphate components identified by solid-state 31P NMR in the very earliest stages of mineralization are protein phosphoryl groups which are not complexed with calcium. However, very small amounts of calcium-complexed protein phosphoryl groups as well as even smaller, trace amounts of apatite crystals were also present at the earliest phases of mineralization. These data support the hypothesis that phosphoproteins complexed with calcium play a significant role in the initiation of bone calcification.

  16. Phosphatidylinositol-specific phospholipase C from Bacillus cereus combines intrinsic phosphotransferase and cyclic phosphodiesterase activities: A sup 31 P NMR study

    SciTech Connect

    Shashidhar, M.S.; Kuppe, A. ); Volwerk, J.J.; Griffith, O.H.

    1990-09-04

    The inositol phosphate products formed during the cleavage of phosphatidylinositol by phosphatidylinositol-specific phospholipase C from Bacillus cereus were analyzed by {sup 31}P NMR. {sup 31}P NMR spectroscopy can distinguish between the inositol phosphate species and phosphatidylinositol. Chemical shift values (with reference to phosphoric acid) observed are {minus}0.41, 3.62, 4.45, and 16.30 ppm for phosphatidylinositol, myo-inositol 1-monophosphate, myo-inositol 2-monophosphate, and myo-inositol 1,2-cyclic monophosphate, respectively. It is shown that under a variety of experimental conditions this phospholipase C cleaves phosphatidylinositol via an intramolecular phosphotransfer reaction producing diacylglycerol and D-myo-inositol 1,2-cyclic monophosphate. The authors also report the new and unexpected observation that the phosphatidylinositol-specific phospholipase C from B. cereus is able to hydrolyze the inositol cyclic phosphate to form D-myo-inositol 1-monophosphate. The enzyme, therefore, possesses phosphotransferase and cyclic phosphodiesterase activities. The second reaction requires thousandfold higher enzyme concentrations to be observed by {sup 31}P NMR. This reaction was shown to be regiospecific in that only the 1-phosphate was produced and stereospecific in that only D-myo-inositol 1,2-cyclic monophosphate was hydrolyzed. Inhibition with a monoclonal antibody specific for the B.cereus phospholipase C showed that the cyclic phosphodiesterase activity is intrinsic to the bacterial enzyme. They propose a two-step mechanism for the phosphatidyl-inositol-specific phospholipase C from B. cereus involving sequential phosphotransferase and cyclic phosphodiesterase activities. This mechanism bears a resemblance to the well-known two-step mechanism of pancreatic ribonuclease, RNase A.

  17. Ultrasonic degradation of 1-H-benzotriazole in water.

    PubMed

    Zúñiga-Benítez, Henry; Soltan, Jafar; Peñuela, Gustavo

    2014-01-01

    This paper reports on the effect of different parameters of ultrasonic power, pollutant initial concentration, pH and the presence of co-existing chemical species (oxygen, nitrogen, ozone, and radical scavengers) on the ultrasonic degradation of the endocrine disruptor 1-H-benzotriazole. Increasing the 1-H-benzotriazole initial concentration from 41.97 to 167.88 μM increased the pollutant degradation rate by 40%. Likewise, a high applied ultrasonic power enhanced the extent of 1-H-benzotriazole removal and its initial degradation rate, which was accelerated in the presence of ozone and oxygen, but inhibited by nitrogen. The most favorable pH for the ultrasonic degradation was acidic media, reaching ∼90% pollutant removal in 2 h. The hydroxyl free radical concentration in the reaction medium was proportional to the ultrasound power and the irradiation time. Kinetic models based on a Langmuir-type mechanism were used to predict the pollutant sonochemical degradation. It was concluded that degradation takes place at both the bubble-liquid interfacial region and in the bulk solution, and OH radicals were the main species responsible for the reaction. Hydroxyl free radicals were generated by water pyrolysis and then diffused into the interfacial region and the bulk solution where most of the solute molecules were present.

  18. Quantitative produced water analysis using mobile 1H NMR

    NASA Astrophysics Data System (ADS)

    Wagner, Lisabeth; Kalli, Chris; Fridjonsson, Einar O.; May, Eric F.; Stanwix, Paul L.; Graham, Brendan F.; Carroll, Matthew R. J.; Johns, Michael L.

    2016-10-01

    Measurement of oil contamination of produced water is required in the oil and gas industry to the (ppm) level prior to discharge in order to meet typical environmental legislative requirements. Here we present the use of compact, mobile 1H nuclear magnetic resonance (NMR) spectroscopy, in combination with solid phase extraction (SPE), to meet this metrology need. The NMR hardware employed featured a sufficiently homogeneous magnetic field, such that chemical shift differences could be used to unambiguously differentiate, and hence quantitatively detect, the required oil and solvent NMR signals. A solvent system consisting of 1% v/v chloroform in tetrachloroethylene was deployed, this provided a comparable 1H NMR signal intensity for the oil and the solvent (chloroform) and hence an internal reference 1H signal from the chloroform resulting in the measurement being effectively self-calibrating. The measurement process was applied to water contaminated with hexane or crude oil over the range 1-30 ppm. The results were validated against known solubility limits as well as infrared analysis and gas chromatography.

  19. {sup 31}P NMR analysis of coal moieties bearing -OH, -NH and -SH functions. Quarterly report, January 1, 1990--March 31, 1990

    SciTech Connect

    Verkade, J.G.

    1990-12-31

    Research continues on the structural analysis of coal. In attempting to derivatize solid coal for solid state NMR analysis, we observed {sup 31}P NMR shifts in an unexpected region; these interesting leads will be pursued on the chance that the reaction we have evoked holds potential for yielding new coal characterizational information. Two very gratifying results have emerged from our {sup 119}Sn chemical shift measurements of a limited set of model compounds in pyridine. Firstly, the chemical shift dispersion is very large for phenols, alcohols and amides. Secondly, unlike {sup 119}Sn chemical shifts in hexane or chloroform, the shifts in pyridine are concentration independent.

  20. Effects of depleting ionic strength on (31)P nuclear magnetic resonance spectra of micellar casein during membrane separation and diafiltration of skim milk.

    PubMed

    Boiani, Mattia; McLoughlin, Padraig; Auty, Mark A E; FitzGerald, Richard J; Kelly, Phil M

    2017-09-01

    Membrane separation processes used in the concentration and isolation of micellar casein-based milk proteins from skim milk rely on extensive permeation of its soluble serum constituents, especially lactose and minerals. Whereas extensive literature exists on how these processes influence the gross composition of milk proteins, we have little understanding of the effects of such ionic depletion on the core structural unit of micellar casein [i.e., the casein phosphate nanocluster (CPN)]. The (31)P nuclear magnetic resonance (NMR) is an analytical technique that is capable of identifying soluble and organic forms of phosphate in milk. Thus, our objective was to investigate changes to the (31)P NMR spectra of skim milk during microfiltration (MF) and diafiltration (DF) by tracking movements in different species of phosphate. In particular, we examined the peak at 1.11 ppm corresponding to inorganic phosphate in the serum, as well as the low-intensity broad signal between 1.5 and 3.0 ppm attributed to casein-associated phosphate in the retentate. The MF concentration and DF using water caused a shift in the relevant (31)P NMR peak that could be minimized if orthophosphate was added to the DF water. However, this did not resolve the simultaneous change in retentate pH and increased solubilization of micellar casein protein. The addition of calcium in combination with orthophosphate prevented micellar casein solubilization and simultaneously contributed to preservation of the CPN structure, except for overcorrection of retentate pH in the acidic direction. A more complex DF solution, involving a combination of phosphate, calcium, and citrate, succeeded in both CPN and micellar casein structure preservation while maintaining retentate pH in the region of the original milk pH. The combination of (31)P NMR as an analytical technique and experimental probe during MF/DF processes provided useful insights into changes occurring to CPN while retaining the micellar state of

  1. Measurement of changes in high-energy phosphates in the cardiac cycle by using gated /sup 31/P nuclear magnetic resonance. [Rats

    SciTech Connect

    Fossel, E.T.; Morgan, H.E.; Ingwall, J.S.

    1980-06-01

    Levels of the high-energy phosphate-containing compounds, ATP and creatine phosphate, and of inorganic phosphate (P/sub i/ were measured as a function of position in the cardiac cycle. Measurements were made on isolated, perfused, working rat hearts through the use of gated /sup 31/P nuclear magnetic resonance spectroscopy. Levels of ATP and creatine phosphate were found to vary during the cardiac cycle and were maximal at minimal aortic pressure and minimal at maximal aortic pressure. P/sub i/ varied inversely with the high-energy phosphates.

  2. (1)H-magnetic resonance spectroscopy ((1)H-MRS) in methamphetamine dependence and methamphetamine induced psychosis.

    PubMed

    Howells, Fleur M; Uhlmann, Anne; Temmingh, Henk; Sinclair, Heidi; Meintjes, Ernesta; Wilson, Don; Stein, Dan J

    2014-03-01

    Methamphetamine (MA) use has been shown to decrease n-acetyl-aspartate (NAA), a marker of neuronal integrity and viability, on (1)H magnetic resonance spectroscopy ((1)H-MRS). However, little work has compared (1)H-MRS in MA dependent individuals and MA dependent individuals with MA induced psychotic disorder (MAP). Twenty six participants with MA dependence (sixteen without psychosis, ten with psychosis - MAP) and nineteen healthy controls underwent 2D-chemical shift imaging (1)H-MRS, which included voxels in the anterior cingulate cortices (ACC), dorsolateral prefrontal cortices (DLPFC), and frontal white matter. We compared metabolite concentrations relative to phosphocreatine+creatine (PCr+Cr) for n-acetyl-aspartate (NAA), n-acetyl-aspartate+n-acetyl-aspartyl-glutamate (NAA+NAAG), glutamate (Glu), glutamate+glutamine (Glu+Gln), myo-inositol, and glycerophosphocholine+phosphocholine (GPC+PCh) across groups. The MA groups showed significantly decreased relative NAA metabolite concentrations for right ACC and right DLPFC, compared with control group. The MA dependent group only showed significantly decreased choline metabolites for right DLPFC, compared with control group. The MAP group's relative NAA metabolite concentrations were significantly correlated with age of initial use and duration of MA use, these correlates were not apparent in MA dependent group. MA use is associated with decreased neuronal integrity and viability, specifically in the right ACC and right DLPFC. MA dependence showed active neurodegeneration in the right DLPFC, this was not apparent in the MAP group and may be related to the use of antipsychotic medication in the MAP group. The effects of MA use in MAP suggest that age of initial use presents a mismatch of neuronal plasticity, in frontal white vs. gray matter and duration of use relates to decreased neuronal integrity and viability. Further study is warranted from this initial study of (1)H-MRS in MAP, in particular longitudinal

  3. Proton-detected 3D (1)H/(13)C/(1)H correlation experiment for structural analysis in rigid solids under ultrafast-MAS above 60 kHz.

    PubMed

    Zhang, Rongchun; Nishiyama, Yusuke; Ramamoorthy, Ayyalusamy

    2015-10-28

    A proton-detected 3D (1)H/(13)C/(1)H chemical shift correlation experiment is proposed for the assignment of chemical shift resonances, identification of (13)C-(1)H connectivities, and proximities of (13)C-(1)H and (1)H-(1)H nuclei under ultrafast magic-angle-spinning (ultrafast-MAS) conditions. Ultrafast-MAS is used to suppress all anisotropic interactions including (1)H-(1)H dipolar couplings, while the finite-pulse radio frequency driven dipolar recoupling (fp-RFDR) pulse sequence is used to recouple dipolar couplings among protons and the insensitive nuclei enhanced by polarization transfer technique is used to transfer magnetization between heteronuclear spins. The 3D experiment eliminates signals from non-carbon-bonded protons and non-proton-bonded carbons to enhance spectral resolution. The 2D (F1/F3) (1)H/(1)H and 2D (13)C/(1)H (F2/F3) chemical shift correlation spectra extracted from the 3D spectrum enable the identification of (1)H-(1)H proximity and (13)C-(1)H connectivity. In addition, the 2D (F1/F2) (1)H/(13)C chemical shift correlation spectrum, incorporated with proton magnetization exchange via the fp-RFDR recoupling of (1)H-(1)H dipolar couplings, enables the measurement of proximities between (13)C and even the remote non-carbon-bonded protons. The 3D experiment also gives three-spin proximities of (1)H-(1)H-(13)C chains. Experimental results obtained from powder samples of L-alanine and L-histidine ⋅ H2O ⋅ HCl demonstrate the efficiency of the 3D experiment.

  4. Proton-detected 3D 1H/13C/1H correlation experiment for structural analysis in rigid solids under ultrafast-MAS above 60 kHz

    NASA Astrophysics Data System (ADS)

    Zhang, Rongchun; Nishiyama, Yusuke; Ramamoorthy, Ayyalusamy

    2015-10-01

    A proton-detected 3D 1H/13C/1H chemical shift correlation experiment is proposed for the assignment of chemical shift resonances, identification of 13C-1H connectivities, and proximities of 13C-1H and 1H-1H nuclei under ultrafast magic-angle-spinning (ultrafast-MAS) conditions. Ultrafast-MAS is used to suppress all anisotropic interactions including 1H-1H dipolar couplings, while the finite-pulse radio frequency driven dipolar recoupling (fp-RFDR) pulse sequence is used to recouple dipolar couplings among protons and the insensitive nuclei enhanced by polarization transfer technique is used to transfer magnetization between heteronuclear spins. The 3D experiment eliminates signals from non-carbon-bonded protons and non-proton-bonded carbons to enhance spectral resolution. The 2D (F1/F3) 1H/1H and 2D 13C/1H (F2/F3) chemical shift correlation spectra extracted from the 3D spectrum enable the identification of 1H-1H proximity and 13C-1H connectivity. In addition, the 2D (F1/F2) 1H/13C chemical shift correlation spectrum, incorporated with proton magnetization exchange via the fp-RFDR recoupling of 1H-1H dipolar couplings, enables the measurement of proximities between 13C and even the remote non-carbon-bonded protons. The 3D experiment also gives three-spin proximities of 1H-1H-13C chains. Experimental results obtained from powder samples of L-alanine and L-histidine ṡ H2O ṡ HCl demonstrate the efficiency of the 3D experiment.

  5. On the use of 31P NMR for the quantification of hydrosoluble phosphorus-containing compounds in coral host tissues and cultured zooxanthellae

    PubMed Central

    Godinot, Claire; Gaysinski, Marc; Thomas, Olivier P.; Ferrier-Pagès, Christine; Grover, Renaud

    2016-01-01

    31P Nuclear Magnetic Resonance (NMR) was assessed to investigate the phosphorus-containing compounds present in the tissues of the scleractinian coral Stylophora pistillata as well as of cultured zooxanthellae (CZ). Results showed that phosphorus-containing compounds observed in CZ were mainly phosphate and phosphate esters. Phosphate accounted for 19 ± 2% of the total phosphorus compounds observed in CZ maintained under low P-levels (0.02 μM). Adding 5 mM of dissolved inorganic phosphorus (KH2PO4) to the CZ culture medium led to a 3.1-fold increase in intracellular phosphate, while adding 5 mM of dissolved organic phosphorus led to a reduction in the concentration of phosphorus compounds, including a 2.5-fold intracellular phosphate decrease. In sharp contrast to zooxanthellae, the host mainly contained phosphonates, and to a lesser extent, phosphate esters and phosphate. Two-months of host starvation decreased the phosphate content by 2.4 fold, while bleaching of fed corals did not modify this content. Based on 31P NMR analyses, this study highlights the importance of phosphonates in the composition of coral host tissues, and illustrates the impact of phosphorus availability on the phosphorus composition of host tissues and CZ, both through feeding of the host and inorganic phosphorus enrichment of the CZ. PMID:26902733

  6. In vivo 31P NMR Study of the Metabolism of Murine Mammary 16/C Adenocarcinoma and Its Response to Chemotherapy, X-Radiation, and Hyperthermia

    NASA Astrophysics Data System (ADS)

    Evanochko, W. T.; Ng, T. C.; Lilly, M. B.; Lawson, A. J.; Corbett, T. H.; Durant, J. R.; Glickson, J. D.

    1983-01-01

    31P NMR spectroscopy with surface coils has been used to monitor, in vivo, the phosphate metabolism of subcutaneously implanted mammary 16/C adenocarcinoma in C3H/He mice. This model tumor was studied during untreated tumor growth and after treatment with adriamycin, hyperthermia, and x-radiation. The mammary 16/C tumor exhibited a Gompertzian growth pattern. Levels of high-energy phosphate metabolites--phosphocreatine and ATP--decreased with increases in tumor mass. There was a concomitant increase in the level of Pi and a decrease in the apparent pH of the tumor. These spectral changes appear to reflect changes in tumor vascularization that accompany tumor growth, the tumor becoming progressively more hypoxic. Partial response of this tumor to chemotherapy with adriamycin was reflected in a small but measurable increase in the phosphocreatine resonance, a decrease in Pi, and a return of the intratumor pH to neutral. Hyperthermia resulted in progressive conversion of the 31P NMR spectrum to that of a dead tumor (high levels of Pi, small levels of residual sugar phosphates and pyridine dinucleotides, and acidic pH). X-irradiation (14.0 Gy) led to disappearance of the phosphocreatine peak within 15 min of treatment. Subsequently, this resonance grew back beyond its pretreatment level. As the tumor receded, its spectrum reflected the characteristics of aerobically metabolizing tissue (high levels of phosphocreatine and ATP and low levels of Pi and sugar phosphates).

  7. 31P NMR characterization and efficiency of new types of water-insoluble phosphate fertilizers to supply plant-available phosphorus in diverse soil types.

    PubMed

    Erro, Javier; Baigorri, Roberto; Yvin, Jean-Claude; Garcia-Mina, Jose M

    2011-03-09

    Hydroponic plant experiments demonstrated the efficiency of a type of humic acid-based water-insoluble phosphate fertilizers, named rhizosphere controlled fertilizers (RCF), to supply available phosphorus (P) to different plant species. This effect was well correlated to the root release of specific organic acids. In this context, the aims of this study are (i) to study the chemical nature of RCF using solid-state (31)P NMR and (ii) to evaluate the real efficiency of RCF matrix as a source of P for wheat plants cultivated in an alkaline and acid soil in comparison with traditional water-soluble (simple superphosphate, SSP) and water-insoluble (dicalcium phosphate, DCP) P fertilizers. The (31)P NMR study revealed the formation of multimetal (double and triple, MgZn and/or MgZnCa) phosphates associated with chelating groups of the humic acid through the formation of metal bridges. With regard to P fertilizer efficiency, the results obtained show that the RCF matrix produced higher plant yields than SSP in both types of soil, with DCP and the water-insoluble fraction from the RCF matrix (WI) exhibiting the best results in the alkaline soil. By contrast, in the acid soil, DCP showed very low efficiency, WI performed on a par with SSP, and RCF exhibited the highest efficiency, thus suggesting a protector effect of humic acid from soil fixation.

  8. In vivo and in vitro 31P magnetic resonance spectroscopic studies of the hepatic response of healthy rats and rats with acute hepatic damage to fructose loading.

    PubMed

    Lu, W; Locke, S J; Brauer, M

    1994-05-01

    The hepatic response to a fructose challenge for control rats, and rats subjected to an acute sublethal dose of carbon tetrachloride (CCl4) or bromobenzene (BB), was compared using dynamic in vivo 31P MRS. Fructose loading conditions were used in which control rats showed only a modest increase in hepatic phosphomonoester (PME), and a small decrease in ATP, Pi, and intracellular pH after fructose administration. Both CCl4 and BB-treated rats showed a much greater fructose-induced accumulation of PME than did controls. Trolox C, a free radical scavenger, prevented most of this PME increase. BB-treated rats, given sufficient time to recover from the hepatotoxic insult, responded to the fructose load similarly to controls. Liver aldolase activities of control, toxicant-treated rats, and toxicant plus Trolox C-treated rats correlated inversely with PME accumulation after fructose loading (correlation coefficient: -0.834, P < 0.05). Perchloric acid extracts of rat livers studied by in vitro 31P MRS confirmed that the PME accumulation after fructose loading is mainly due to an increase in fructose 1-phosphate. These studies are consistent with the aldolase-catalyzed cleavage of fructose 1-phosphate being rate-limiting in hepatic fructose metabolism, and that the CCl4 and BB treatment modify and inactivate the aldolase enzyme.

  9. Structural study, 31P NMR and europium photoluminescence properties of a new synthetic fillowite-type phosphate: Na3SrMg11(PO4)9

    NASA Astrophysics Data System (ADS)

    Boukhris, Amal; Ben Hamed, Teycir; Glorieux, Benoit; Ben Amara, Mongi

    2017-05-01

    A new phosphate compound, Na3SrMg11(PO4)9 was synthesized as single crystals by flux method and as powdered sample by Pechini technique and investigated by X-ray diffraction, 31P NMR and photoluminescence spectroscopies. This compound crystallizes in the rhombohedral space group R 3 bar and its equivalent hexagonal cell has the following parameters: a = 14.941(1) Ǻ, c = 42.478(2) Ǻ and Z = 12. The structure consisted of MgOx (x = 5,6), NaOx (x = 6,7) and (Na,Sr)Ox (x = 8,9) polyhedra which are linked either directly through common corners, edges and faces and by means of the PO4 tetrahedra via common corners and edges, giving rise to a three-dimensional framework, similar to that of the fillowite-like structure. 31P NMR spectroscopy confirmed the presence of six distinct phosphors sites in the structure. Finally, strontium was partially substitute by divalent europium in order to examine whether this material could be used in optical applications. Optical studies were performed on the Na3Sr0.98Eu2+0.02Mg11(PO4)9 compound. The photoluminescence are consistent with the crystal structural and show various properties as a function of the excitation wavelength.

  10. Emergence of Novel Antiferromagnetic Order Intervening between Two Superconducting Phases in LaFe(As1-xPx)O: 31P-NMR Studies

    NASA Astrophysics Data System (ADS)

    Mukuda, Hidekazu; Engetsu, Fuko; Shiota, Takayoshi; Lai, Kwing To; Yashima, Mitsuharu; Kitaoka, Yoshio; Miyasaka, Shigeki; Tajima, Setsuko

    2014-08-01

    Systematic 31P-NMR studies of LaFe(As1-xPx)O compounds have revealed the emergence of a novel antiferromagnetic ordered phase (AFM-2) at 0.4 ≤ x ≤ 0.7 that intervenes between two superconductivity (SC) phases. This AFM-2 phase with Néel temperature TN = 35 K for x = 0.6 is in strong contrast to the AFM order (AFM-1) at x = 0 exhibiting TN of 140 K. Previous 31P-NMR studies of LaFe(As1-xPx)(O1-yFy) have revealed that Tc reaches a maximum of 24 K for x = 0.6 as a result of the marked enhancement of AFM spin fluctuations at low energies due to electron doping by the flourine substitution of y = 0.05 for oxygen. The reason for this unexpected result has been found in the present work, that is, the emergence of AFM-2 at 0.4 ≤ x ≤ 0.7 without electron doping. We note that AFM spin fluctuations arising from interband nesting on the dXZ/dYZ orbits must be a key factor for the occurrence of SC around AFM-2.

  11. In Vivo 31P-Nuclear Magnetic Resonance Studies of Glyphosate Uptake, Vacuolar Sequestration, and Tonoplast Pump Activity in Glyphosate-Resistant Horseweed1[W

    PubMed Central

    Ge, Xia; d’Avignon, D. André; Ackerman, Joseph J.H.; Sammons, R. Douglas

    2014-01-01

    Horseweed (Conyza canadensis) is considered a significant glyphosate-resistant (GR) weed in agriculture, spreading to 21 states in the United States and now found globally on five continents. This laboratory previously reported rapid vacuolar sequestration of glyphosate as the mechanism of resistance in GR horseweed. The observation of vacuole sequestration is consistent with the existence of a tonoplast-bound transporter. 31P-Nuclear magnetic resonance experiments performed in vivo with GR horseweed leaf tissue show that glyphosate entry into the plant cell (cytosolic compartment) is (1) first order in extracellular glyphosate concentration, independent of pH and dependent upon ATP; (2) competitively inhibited by alternative substrates (aminomethyl phosphonate [AMPA] and N-methyl glyphosate [NMG]), which themselves enter the plant cell; and (3) blocked by vanadate, a known inhibitor/blocker of ATP-dependent transporters. Vacuole sequestration of glyphosate is (1) first order in cytosolic glyphosate concentration and dependent upon ATP; (2) competitively inhibited by alternative substrates (AMPA and NMG), which themselves enter the plant vacuole; and (3) saturable. 31P-Nuclear magnetic resonance findings with GR horseweed are consistent with the active transport of glyphosate and alternative substrates (AMPA and NMG) across the plasma membrane and tonoplast in a manner characteristic of ATP-binding cassette transporters, similar to those that have been identified in mammalian cells. PMID:25185124

  12. Quantitative 31P NMR for Simultaneous Trace Analysis of Organophosphorus Pesticides in Aqueous Media Using the Stir Bar Sorptive Extraction Method

    NASA Astrophysics Data System (ADS)

    Ansari, S.; Talebpour, Z.; Molaabasi, F.; Bijanzadeh, H. R.; Khazaeli, S.

    2016-09-01

    The analysis of pesticides in water samples is of primary concern for quality control laboratories due to the toxicity of these compounds and their associated public health risk. A novel analytical method based on stir bar sorptive extraction (SBSE), followed by 31P quantitative nuclear magnetic resonance (31P QNMR), has been developed for simultaneously monitoring and determining four organophosphorus pesticides (OPPs) in aqueous media. The effects of factors on the extraction efficiency of OPPs were investigated using a Draper-Lin small composite design. An optimal sample volume of 4.2 mL, extraction time of 96 min, extraction temperature of 42°C, and desorption time of 11 min were obtained. The results showed reasonable linearity ranges for all pesticides with correlation coefficients greater than 0.9920. The limit of quantification (LOQ) ranged from 0.1 to 2.60 mg/L, and the recoveries of spiked river water samples were from 82 to 94% with relative standard deviation (RSD) values less than 4%. The results show that this method is simple, selective, rapid, and can be applied to other sample matrices.

  13. Distribution and mobility of phosphates and sodium ions in cheese by solid-state 31P and double-quantum filtered 23Na NMR spectroscopy.

    PubMed

    Gobet, Mallory; Rondeau-Mouro, Corinne; Buchin, Solange; Le Quéré, Jean-Luc; Guichard, Elisabeth; Foucat, Loïc; Moreau, Céline

    2010-04-01

    The feasibility of solid-state magic angle spinning (MAS) (31)P nuclear magnetic resonance (NMR) spectroscopy and (23)Na NMR spectroscopy to investigate both phosphates and Na(+) ions distribution in semi-hard cheeses in a non-destructive way was studied. Two semi-hard cheeses of known composition were made with two different salt contents. (31)P Single-pulse excitation and cross-polarization MAS experiments allowed, for the first time, the identification and quantification of soluble and insoluble phosphates in the cheeses. The presence of a relatively 'mobile' fraction of colloidal phosphates was evidenced. The detection by (23)Na single-quantum NMR experiments of all the sodium ions in the cheeses was validated. The presence of a fraction of 'bound' sodium ions was evidenced by (23)Na double-quantum filtered NMR experiments. We demonstrated that NMR is a suitable tool to investigate both phosphates and Na(+) ions distributions in cheeses. The impact of the sodium content on the various phosphorus forms distribution was discussed and results demonstrated that NMR would be an important tool for the cheese industry for the processes controls.

  14. Probing the PI3K/Akt/mTor pathway using 31P-NMR spectroscopy: routes to glycogen synthase kinase 3

    PubMed Central

    Phyu, Su M.; Tseng, Chih-Chung; Fleming, Ian N.; Smith, Tim A. D.

    2016-01-01

    Akt is an intracellular signalling pathway that serves as an essential link between cell surface receptors and cellular processes including proliferation, development and survival. The pathway has many downstream targets including glycogen synthase kinase3 which is a major regulatory kinase for cell cycle transit as well as controlling glycogen synthase activity. The Akt pathway is frequently up-regulated in cancer due to overexpression of receptors such as the epidermal growth factor receptor, or mutation of signalling pathway kinases resulting in inappropriate survival and proliferation. Consequently anticancer drugs have been developed that target this pathway. MDA-MB-468 breast and HCT8 colorectal cancer cells were treated with inhibitors including LY294002, MK2206, rapamycin, AZD8055 targeting key kinases in/associated with Akt pathway and the consistency of changes in 31P-NMR-detecatable metabolite content of tumour cells was examined. Treatment with the Akt inhibitor MK2206 reduced phosphocholine levels in MDA-MB-468 cells. Treatment with either the phosphoinositide-3-kinase inhibitor, LY294002 and pan-mTOR inhibitor, AZD8055 but not pan-Akt inhibitor MK2206 increased uridine-5′-diphosphate-hexose cell content which was suppressed by co-treatment with glycogen synthase kinase 3 inhibitor SB216763. This suggests that there is an Akt-independent link between phosphoinositol-3-kinase and glycogen synthase kinase3 and demonstrates the potential of 31P-NMR to probe intracellular signalling pathways. PMID:27811956

  15. Gray matter-specific changes in brain bioenergetics after acute sleep deprivation: a 31P magnetic resonance spectroscopy study at 4 Tesla.

    PubMed

    Plante, David T; Trksak, George H; Jensen, J Eric; Penetar, David M; Ravichandran, Caitlin; Riedner, Brady A; Tartarini, Wendy L; Dorsey, Cynthia M; Renshaw, Perry F; Lukas, Scott E; Harper, David G

    2014-12-01

    A principal function of sleep may be restoration of brain energy metabolism caused by the energetic demands of wakefulness. Because energetic demands in the brain are greater in gray than white matter, this study used linear mixed-effects models to examine tissue-type specific changes in high-energy phosphates derived using 31P magnetic resonance spectroscopy (MRS) after sleep deprivation and recovery sleep. Experimental laboratory study. Outpatient neuroimaging center at a private psychiatric hospital. A total of 32 MRS scans performed in eight healthy individuals (mean age 35 y; range 23-51 y). Phosphocreatine (PCr) and β-nucleoside triphosphate (NTP) were measured using 31P MRS three dimensional-chemical shift imaging at high field (4 Tesla) after a baseline night of sleep, acute sleep deprivation (SD), and 2 nights of recovery sleep. Novel linear mixed-effects models were constructed using spectral and tissue segmentation data to examine changes in bioenergetics in gray and white matter. PCr increased in gray matter after 2 nights of recovery sleep relative to SD with no significant changes in white matter. Exploratory analyses also demonstrated that increases in PCr were associated with increases in electroencephalographic slow wave activity during recovery sleep. No significant changes in β-NTP were observed. These results demonstrate that sleep deprivation and subsequent recovery-induced changes in high-energy phosphates primarily occur in gray matter, and increases in PCr after recovery sleep may be related to sleep homeostasis. © 2014 Associated Professional Sleep Societies, LLC.

  16. On the use of 31P NMR for the quantification of hydrosoluble phosphorus-containing compounds in coral host tissues and cultured zooxanthellae.

    PubMed

    Godinot, Claire; Gaysinski, Marc; Thomas, Olivier P; Ferrier-Pagès, Christine; Grover, Renaud

    2016-02-23

    (31)P Nuclear Magnetic Resonance (NMR) was assessed to investigate the phosphorus-containing compounds present in the tissues of the scleractinian coral Stylophora pistillata as well as of cultured zooxanthellae (CZ). Results showed that phosphorus-containing compounds observed in CZ were mainly phosphate and phosphate esters. Phosphate accounted for 19 ± 2% of the total phosphorus compounds observed in CZ maintained under low P-levels (0.02 μM). Adding 5 mM of dissolved inorganic phosphorus (KH2PO4) to the CZ culture medium led to a 3.1-fold increase in intracellular phosphate, while adding 5 mM of dissolved organic phosphorus led to a reduction in the concentration of phosphorus compounds, including a 2.5-fold intracellular phosphate decrease. In sharp contrast to zooxanthellae, the host mainly contained phosphonates, and to a lesser extent, phosphate esters and phosphate. Two-months of host starvation decreased the phosphate content by 2.4 fold, while bleaching of fed corals did not modify this content. Based on (31)P NMR analyses, this study highlights the importance of phosphonates in the composition of coral host tissues, and illustrates the impact of phosphorus availability on the phosphorus composition of host tissues and CZ, both through feeding of the host and inorganic phosphorus enrichment of the CZ.

  17. Free magnesium levels in normal human brain and brain tumors: sup 31 P chemical-shift imaging measurements at 1. 5 T

    SciTech Connect

    Taylor, J.S.; Vigneron, D.B.; Murphy-Boesch, J.; Nelson, S.J.; Kessler, H.B.; Coia, L.; Curran, W.; Brown, T.R. )

    1991-08-01

    The authors have studied a series of normal subjects and patients with brain tumors, by using {sup 31}P three-dimensional chemical shift imaging to obtain localized {sup 31}P spectra of the brain. A significant proportion of brain cytosolic ATP in normal brain is not complexed to Mg{sup 2+}, as indicated by the chemical shift {delta} of the {beta}-P resonance of ATP. The ATP {beta}P resonance position in brain thus is sensitive to changes in intracellular free Mg{sup 2+} concentration and in the proportion of ATP complexed with Mg because this shift lies on the rising portion of the {delta} vs. Mg{sup 2+} titration curve for ATP. They have measured the ATP {beta}-P shift and compared intracellular free Mg{sup 2+} concentration and fractions of free ATP for normal individuals and a limited series of patients with brain tumors. In four of the five spectra obtained from brain tissue containing a substantial proportion of tumor, intracellular free Mg{sup 2+} was increased, and the fraction of free ATP was decreased, compared with normal brain.

  18. On the use of 31P NMR for the quantification of hydrosoluble phosphorus-containing compounds in coral host tissues and cultured zooxanthellae

    NASA Astrophysics Data System (ADS)

    Godinot, Claire; Gaysinski, Marc; Thomas, Olivier P.; Ferrier-Pagès, Christine; Grover, Renaud

    2016-02-01

    31P Nuclear Magnetic Resonance (NMR) was assessed to investigate the phosphorus-containing compounds present in the tissues of the scleractinian coral Stylophora pistillata as well as of cultured zooxanthellae (CZ). Results showed that phosphorus-containing compounds observed in CZ were mainly phosphate and phosphate esters. Phosphate accounted for 19 ± 2% of the total phosphorus compounds observed in CZ maintained under low P-levels (0.02 μM). Adding 5 mM of dissolved inorganic phosphorus (KH2PO4) to the CZ culture medium led to a 3.1-fold increase in intracellular phosphate, while adding 5 mM of dissolved organic phosphorus led to a reduction in the concentration of phosphorus compounds, including a 2.5-fold intracellular phosphate decrease. In sharp contrast to zooxanthellae, the host mainly contained phosphonates, and to a lesser extent, phosphate esters and phosphate. Two-months of host starvation decreased the phosphate content by 2.4 fold, while bleaching of fed corals did not modify this content. Based on 31P NMR analyses, this study highlights the importance of phosphonates in the composition of coral host tissues, and illustrates the impact of phosphorus availability on the phosphorus composition of host tissues and CZ, both through feeding of the host and inorganic phosphorus enrichment of the CZ.

  19. In vivo 31P nuclear magnetic resonance spectroscopy of experimental murine tumours and human tumour xenografts: effects of blood flow modification.

    PubMed Central

    Bremner, J. C.; Counsell, C. J.; Adams, G. E.; Stratford, I. J.; Wood, P. J.; Dunn, J. F.; Radda, G. K.

    1991-01-01

    The effect of hydralazine on tumours appears to vary depending on tumour type. Blood flow and radiation sensitivity decrease more in murine tumours than human tumour xenografts. In this study a comparison between various tumour types has been made using in vivo 31P nuclear magnetic resonance spectroscopy (NMRS) to follow the metabolic responses occurring after clamping or intravenous administration of hydralazine (5 mg kg-1). Large increases in the Pi/total phosphate ratio were found with the murine sarcomas, KHT and RIF-1 implanted into C3H/He mice. However little or no effect was seen for the two human xenografted tumours, HX118 and HT29 implanted in MFI nu/nu/01a mice. An intermediate response was observed for KHT tumours grown in nu/nu mice. All tumours showed a large response to clamping. The anaesthetic Hypnorm/Hypnovel has a great influence on the response of the tumour metabolism to hydralazine appearing to both prolong and increase the changes induced. There is evidence to support the theory that the changes in 31P spectra are related to the oxygen status of the tumours. PMID:1931606

  20. Proton-detected 3D 14N/14N/1H isotropic shift correlation experiment mediated through 1H-1H RFDR mixing on a natural abundant sample under ultrafast MAS

    NASA Astrophysics Data System (ADS)

    Pandey, Manoj Kumar; Nishiyama, Yusuke

    2015-09-01

    In this contribution, we have demonstrated a proton detection-based approach on a natural abundant powdered L-Histidine HCl-H2O sample at ultrafast magic angle spinning (MAS) to accomplish 14N/14N correlation from a 3D 14N/14N/1H isotropic shift correlation experiment mediated through 1H finite-pulse radio frequency-driven recoupling (fp-RFDR). Herein the heteronuclear magnetization transfer between 14N and 1H has been achieved by HMQC experiment, whereas 14N/14N correlation is attained through enhanced 1H-1H spin diffusion process due to 1H-1H dipolar recoupling during the RFDR mixing. While the use of ultrafast MAS (90 kHz) provides sensitivity enhancement through increased 1H transverse relaxation time (T2), the use of micro-coil probe which can withstand strong 14N radio frequency (RF) fields further improves the sensitivity per unit sample volume.

  1. Complete assignment of NMR data of 22 phenyl-1H-pyrazoles' derivatives.

    PubMed

    de Oliveira, Aline Lima; Alves de Oliveira, Carlos Henrique; Mairink, Laura Maia; Pazini, Francine; Menegatti, Ricardo; Lião, Luciano Morais

    2011-08-01

    Complete assignment of (1)H and (13)C NMR chemical shifts and J((1)H/(1)H and (1)H/(19)F) coupling constants for 22 1-phenyl-1H-pyrazoles' derivates were performed using the concerted application of (1)H 1D and (1)H, (13)C 2D gs-HSQC and gs-HMBC experiments. All 1-phenyl-1H-pyrazoles' derivatives were synthesized as described by Finar and co-workers. The formylated 1-phenyl-1H-pyrazoles' derivatives were performed under Duff's conditions.

  2. Non-invasive assessment of phosphate metabolism and oxidative capacity in working skeletal muscle in healthy young Chinese volunteers using (31)P Magnetic Resonance Spectroscopy.

    PubMed

    Li, Ming; Chen, Fei; Wang, Huiting; Wu, Wenbo; Zhang, Xin; Tian, Chuanshuai; Yu, Haiping; Liu, Renyuan; Zhu, Bin; Zhang, Bing; Dai, Zhenyu

    2016-01-01

    Background. Generally, males display greater strength and muscle capacity than females while performing a task. Muscle biopsy is regarded as the reference method of evaluating muscle functions; however, it is invasive and has sampling errors, and is not practical for longitudinal studies and dynamic measurement during excise. In this study, we built an in-house force control and gauge system for quantitatively applying force to quadriceps while the subjects underwent (31)P Magnetic Resonance Spectroscopy ((31)P-MRS); our aim was to investigate if there is a sex difference of phosphate metabolite change in working muscles in young heathy Chinese volunteers. Methods. Volunteers performed knee-extending excises using a force control and gauge system while lying prone in a Philips 3T Magnetic Resonance (MR) scanner. The (31)P-MRS coil was firmly placed under the middle of the quadriceps . (31)P-MRS measurements of inorganic phosphate (Pi), phosphocreatine (PCr) and adenosine triphosphate (ATP) were acquired from quadriceps while subjects were in a state of pre-, during- and post-exercise. The PCr, Pi, PCr/Pi, PCr/ATP, pH, work/energy cost ratio (WE), kPCr and oxidative capacity were compared between males and females. Results. A total of 17 volunteers underwent the study. Males: N = 10, age = 23.30 ± 1.25years; females: N = 7, age = 23.57 ± 0.79 years. In this study, males had significantly greater WE (16.33 ± 6.46 vs. 7.82 ± 2.16, p = 0.002) than females. Among PCr, Pi, PCr/Pi, PCr/ATP, pH, kPCr and oxidative capacity at different exercise status, only PCr/Pi (during-exercise, males = 5.630 ± 1.647, females = 4.014 ± 1.298, p = 0.047), PCr/ATP (during-exercise, males =1.273 ± 0.219, females = 1.523 ± 0.167, p = 0.025), and ATP (post-exercise, males = 24.469 ± 3.911 mmol/kg, females = 18.353 ± 4.818 mmol/kg, p = 0.035) had significant sex differences. Males had significantly greater PCr/Pi, but less PCr/ATP than females during exercise, suggesting males had

  3. (1)H-magnetic resonance spectroscopy in social anxiety disorder.

    PubMed

    Howells, Fleur M; Hattingh, Coenraad J; Syal, Supriya; Breet, Elsie; Stein, Dan J; Lochner, Christine

    2015-04-03

    Social anxiety disorder (SAD) is characterized by excessive anxiety about social interaction or performance situations, leading to avoidance and clinically significant distress. A growing literature on the neurobiology of SAD has suggested that the reward/avoidance basal ganglia circuitry in general and the glutamatergic system in particular may play a role. In the current study, we investigated (1)H-magnetic resonance spectroscopy ((1)H-MRS) concentrations in cortical, striatal, and thalamic circuitry, as well as their associations with measures of social anxiety and related symptoms, in patients with primary SAD. Eighteen adult individuals with SAD and 19 age- and sex- matched controls participated in this study. (1)H-MRS was used to determine relative metabolite concentrations in the anterior cingulate cortex (ACC) using single voxel spectroscopy (reporting relative N-acetyl-aspartate (NAA), N-acetyl-aspartate with N-acetyl-aspartyl-glutamate (NAA+NAAG), glycerophosphocholine with phosphocholine (GPC+PCh), myo-inositol, glutamate (Glu), and glutamate with its precursor glutamine (Glu+Gln)), and the caudate, putamen and thalami bilaterally using two dimensional chemical shift imaging (reporting relative NAA+NAAG and GPC+PCh). Relationships between metabolite concentrations and measures of social anxiety and related symptoms were also determined. Measures of social anxiety included symptom severity, blushing propensity, and gaze anxiety/avoidance. We found, first, decreased relative glutamate concentration in the ACC of SAD and changes in myo-inositol with measures of social anxiety. Second, NAA metabolite concentration was increased in thalamus of SAD, and choline metabolite concentrations were related to measures of social anxiety. Lastly, choline metabolite concentration in the caudate and putamen showed changes in relation to measures of social anxiety. These findings are consistent with evidence that the reward/avoidance basal ganglia circuitry, as well as

  4. Differentiation between cortical atrophy and hydrocephalus using 1H MRS.

    PubMed

    Bluml, S; McComb, J G; Ross, B D

    1997-03-01

    Quantitative 1H MRS to determine cerebral metabolite patterns and MRI to determine CSF flow were applied to 12 patients with ventricular dilation-Group A, cortical atrophy (N = 5); or Group B, hydrocephalus (N = 7)- and in 9 normal controls. While mean brain water (Group A = 80% +/- 6; Group B = 86% +/- 5; normal = 85% +/- 4) did not differ between the two groups of patients and controls, 1H MRS distinguished those patients with cortical atrophy (Group A) (N-acetylaspartate/ creatine (NAA/Cr) = 0.69 +/- 0.17, versus normal = 1.06 +/- 0.16; P < 0.002; [NAA] = 5.9 +/- 1.3 mmoles/kg, versus normal 8.0 +/- 1.4; P < 0.02) from those with hydrocephalus (Group B) (NAA/Cr = 1.16 +/- 0.11; [NAA] = 9.2 +/- 1.2; P > 0.13 and P > 0.07). Lactate levels were elevated in 3/5 patients with cortical atrophy, but in 0/7 of those with hydrocephalus. Mean absolute concentrations (mmoles/kg) of the five major cerebral osmolytes were 41 +/- 4 (Group A), 43 +/- 6 (Group B), and 42 +/- 4 (normal), so that despite massive brain deformation, constant osmolality was maintained. 1H MRS may directly benefit surgical planning in hydrocephalus infants by clearly identifying those with cortical atrophy who do not require CSF diversion. Thinning of the cortical mantle in hydrocephalus may result from osmotically driven reduction in individual cell volumes, (shrinkage), rather than brain-compression.

  5. 23Na and (1)H NMR microimaging of intact plants.

    PubMed

    Olt, S; Krötz, E; Komor, E; Rokitta, M; Haase, A

    2000-06-01

    (23)Na NMR microimaging is described to map, for the first time, the sodium distribution in living plants. As an example, the response of 6-day-old seedlings of Ricinus communis to exposure to sodium chloride concentrations from 5 to 300 mM was observed in vivo using (23)Na as well as (1)H NMR microimaging. Experiments were performed at 11.75 T with a double resonant (23)Na-(1)H probehead. The probehead was homebuilt and equipped with a climate chamber. T(1) and T(2) of (23)Na were measured in the cross section of the hypocotyl. Within 85 min (23)Na images with an in-plane resolution of 156 x 156 micrometer were acquired. With this spatial information, the different types of tissue in the hypocotyl can be discerned. The measurement time appears to be short compared to the time scale of sodium uptake and accumulation in the plant so that the kinetics of salt stress can be followed. In conclusion, (23)Na NMR microimaging promises great potential for physiological studies of the consequences of salt stress on the macroscopic level and thus may become a unique tool for characterizing plants with respect to salt tolerance and salt sensitivity. Copyright 2000 Academic Press.

  6. 23Na and 1H NMR Microimaging of Intact Plants

    NASA Astrophysics Data System (ADS)

    Olt, Silvia; Krötz, Eva; Komor, Ewald; Rokitta, Markus; Haase, Axel

    2000-06-01

    23Na NMR microimaging is described to map, for the first time, the sodium distribution in living plants. As an example, the response of 6-day-old seedlings of Ricinus communis to exposure to sodium chloride concentrations from 5 to 300 mM was observed in vivo using 23Na as well as 1H NMR microimaging. Experiments were performed at 11.75 T with a double resonant 23Na-1H probehead. The probehead was homebuilt and equipped with a climate chamber. T1 and T2 of 23Na were measured in the cross section of the hypocotyl. Within 85 min 23Na images with an in-plane resolution of 156 × 156 μm were acquired. With this spatial information, the different types of tissue in the hypocotyl can be discerned. The measurement time appears to be short compared to the time scale of sodium uptake and accumulation in the plant so that the kinetics of salt stress can be followed. In conclusion, 23Na NMR microimaging promises great potential for physiological studies of the consequences of salt stress on the macroscopic level and thus may become a unique tool for characterizing plants with respect to salt tolerance and salt sensitivity.

  7. Metabolomic insight into soy sauce through (1)H NMR spectroscopy.

    PubMed

    Ko, Bong-Kuk; Ahn, Hyuk-Jin; van den Berg, Frans; Lee, Cherl-Ho; Hong, Young-Shick

    2009-08-12

    Soy sauce, a well-known seasoning in Asia and throughout the world, consists of many metabolites that are produced during fermentation or aging and that have various health benefits. However, their comprehensive assessment has been limited due to targeted or instrumentally specific analysis. This paper presents for the first time a metabolic characterization of soy sauce, especially that aged up to 12 years, to obtain a global understanding of the metabolic variations through (1)H NMR spectroscopy coupled with multivariate pattern recognition techniques. Elevated amino acids and organic acids and the consumption of carbohydrate were associated with continuous involvement of microflora in aging for 12 years. In particular, continuous increases in the levels of betaine were found during aging for up to 12 years, demonstrating that microbial- or enzyme-related metabolites were also coupled with osmotolerant or halophilic bacteria present during aging. This work provides global insights into soy sauce through a (1)H NMR-based metabolomic approach that enhances the current understanding of the holistic metabolome and allows assessment of soy sauce quality.

  8. The 1H NMR Profile of Healthy Dog Cerebrospinal Fluid

    PubMed Central

    Musteata, Mihai; Nicolescu, Alina; Solcan, Gheorghe; Deleanu, Calin

    2013-01-01

    The availability of data for reference values in cerebrospinal fluid for healthy humans is limited due to obvious practical and ethical issues. The variability of reported values for metabolites in human cerebrospinal fluid is quite large. Dogs present great similarities with humans, including in cases of central nervous system pathologies. The paper presents the first study on healthy dog cerebrospinal fluid metabolomic profile using 1H NMR spectroscopy. A number of 13 metabolites have been identified and quantified from cerebrospinal fluid collected from a group of 10 mix breed healthy dogs. The biological variability as resulting from the relative standard deviation of the physiological concentrations of the identified metabolites had a mean of 18.20% (range between 9.3% and 44.8%). The reported concentrations for metabolites may be used as normal reference values. The homogeneity of the obtained results and the low biologic variability show that the 1H NMR analysis of the dog’s cerebrospinal fluid is reliable in designing and interpreting clinical and therapeutic trials in dogs with central nervous system pathologies. PMID:24376499

  9. Profiling formulated monoclonal antibodies by (1)H NMR spectroscopy.

    PubMed

    Poppe, Leszek; Jordan, John B; Lawson, Ken; Jerums, Matthew; Apostol, Izydor; Schnier, Paul D

    2013-10-15

    Nuclear magnetic resonance (NMR) is arguably the most direct methodology for characterizing the higher-order structure of proteins in solution. Structural characterization of proteins by NMR typically utilizes heteronuclear experiments. However, for formulated monoclonal antibody (mAb) therapeutics, the use of these approaches is not currently tenable due to the requirements of isotope labeling, the large size of the proteins, and the restraints imposed by various formulations. Here, we present a new strategy to characterize formulated mAbs using (1)H NMR. This method, based on the pulsed field gradient stimulated echo (PGSTE) experiment, facilitates the use of (1)H NMR to generate highly resolved spectra of intact mAbs in their formulation buffers. This method of data acquisition, along with postacquisition signal processing, allows the generation of structural and hydrodynamic profiles of antibodies. We demonstrate how variation of the PGSTE pulse sequence parameters allows proton relaxation rates and relative diffusion coefficients to be obtained in a simple fashion. This new methodology can be used as a robust way to compare and characterize mAb therapeutics.

  10. Synthesis, {sup 77}Se and {sup 119}Sn NMR study, and X-ray crystal structure of the Sn{sub 4}Se{sub 10}{sup 4-} anion and Raman spectra of SnSe{sub 4}{sup 4-} and Sn{sub 4}Se{sub 10}{sup 4-}

    SciTech Connect

    Campbell, J.; DiCiommo, D.P.; Pirani, A.M.

    1995-12-06

    The novel selenostannate(IV) anion, Sn{sub 4}Se{sub 10}{sup 4-}, has been obtained by extracting the ternary alloy KSn{sub 0.67}Se{sub 1.93} in ethylenediamine (en) and liquid NH{sub 3} in the presence of 2, 2, 2-crypt (4, 7, 13, 16, 21, 24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane) and characterized in solution by {sup 77}Se and {sup 119}Sn NMR spectroscopy and in the solid state by X-ray crystallography and Raman spectroscopy. The scalar couplings, {sup 1}J({sup 119}Sn-{sup 77}Se) and {sup 2}J({sup 119}Sn-{sup 77}Sn), have been determined and compared with those of related systems. The salt, (2, 2, 2-crypt-K{sup +}){sub 4}Sn{sub 4}Se{sub 10}{sup 4-}, crystallizes in the triclinic system, space group P{bar 1}, with Z = 2 and a = 14.769(2) {Angstrom}, b = 15.580(1) {Angstrom}, c = 26.275(4) {Angstrom}, {alpha} = 79.19(1){degrees}, {beta} = 85.65(1){degrees}, and {gamma} = 85.870(8){degrees} at 24 {degrees}C. The solid state and solution anion geometry is of the adamantanoid type where the Sn{sup IV} atoms occupy the bridgehead positions and the Se atoms occupy the bridging and terminal sites. The terminal [average, 2.425(2) {Angstrom}] and bridging [average, 2.425(2){Angstrom}] and bridging [average, 2.548(2) {Angstrom}] Sn-Se bond distances were found to correlate with their respective {sup 1}J({sup 119}Sn-{sup 77}Se) coupling constants. The Raman spectrum of the Sn{sub 4}Se{sub 10}{sup 4-} anion has been assigned and compared to those of related adamantanoid systems and SnSe{sub 4}{sup -4}.

  11. Dynamics-based selective 2D 1H/1H chemical shift correlation spectroscopy under ultrafast MAS conditions

    NASA Astrophysics Data System (ADS)

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2015-05-01

    Dynamics plays important roles in determining the physical, chemical, and functional properties of a variety of chemical and biological materials. However, a material (such as a polymer) generally has mobile and rigid regions in order to have high strength and toughness at the same time. Therefore, it is difficult to measure the role of mobile phase without being affected by the rigid components. Herein, we propose a highly sensitive solid-state NMR approach that utilizes a dipolar-coupling based filter (composed of 12 equally spaced 90° RF pulses) to selectively measure the correlation of 1H chemical shifts from the mobile regions of a material. It is interesting to find that the rotor-synchronized dipolar filter strength decreases with increasing inter-pulse delay between the 90° pulses, whereas the dipolar filter strength increases with increasing inter-pulse delay under static conditions. In this study, we also demonstrate the unique advantages of proton-detection under ultrafast magic-angle-spinning conditions to enhance the spectral resolution and sensitivity for studies on small molecules as well as multi-phase polymers. Our results further demonstrate the use of finite-pulse radio-frequency driven recoupling pulse sequence to efficiently recouple weak proton-proton dipolar couplings in the dynamic regions of a molecule and to facilitate the fast acquisition of 1H/1H correlation spectrum compared to the traditional 2D NOESY (Nuclear Overhauser effect spectroscopy) experiment. We believe that the proposed approach is beneficial to study mobile components in multi-phase systems, such as block copolymers, polymer blends, nanocomposites, heterogeneous amyloid mixture of oligomers and fibers, and other materials.

  12. A theoretical study of rotational diffusion models for rod-shaped viruses. The influence of motion on 31P nuclear magnetic resonance lineshapes and transversal relaxation.

    PubMed Central

    Magusin, P C; Hemminga, M A

    1993-01-01

    Information about the interaction between nucleic acids and coat proteins in intact virus particles may be obtained by studying the restricted backbone dynamics of the incapsulated nucleic acids using 31P nuclear magnetic resonance (NMR) spectroscopy. In this article, simulations are carried out to investigate how reorientation of a rod-shaped virus particle as a whole and isolated nucleic acid motions within the virion influence the 31P NMR lineshape and transversal relaxation dominated by the phosphorus chemical shift anisotropy. Two opposite cases are considered on a theoretical level. First, isotropic rotational diffusion is used as a model for mobile nucleic acids that are loosely or partially bound to the protein coat. The effect of this type of diffusion on lineshape and transversal relaxation is calculated by solving the stochastic Liouville equation by an expansion in spherical functions. Next, uniaxial rotational diffusion is assumed to represent the mobility of phosphorus in a virion that rotates as a rigid rod about its length axis. This type of diffusion is approximated by an exchange process among discrete sites. As turns out from these simulations, the amplitude and the frequency of the motion can only be unequivocally determined from experimental data by a combined analysis of the lineshape and the transversal relaxation. In the fast motional region both the isotropic and the uniaxial diffusion model predict the same transversal relaxation as the Redfield theory. For very slow motion, transversal relaxation resembles the nonexponential relaxation as observed for water molecules undergoing translational diffusion in a magnetic field gradient. In this frequency region T2e is inversely proportional to the cube root of the diffusion coefficient. In addition to the isotropic and uniaxial diffusion models, a third model is presented, in which fast restricted nucleic acid backbone motions dominating the lineshape are superimposed on a slow rotation of the

  13. Depth-resolved surface coil MRS (DRESS)-localized dynamic (31) P-MRS of the exercising human gastrocnemius muscle at 7 T.

    PubMed

    Valkovič, Ladislav; Chmelík, Marek; Just Kukurová, Ivica; Jakubová, Michaela; Kipfelsberger, Monika Christina; Krumpolec, Patrik; Tušek Jelenc, Marjeta; Bogner, Wolfgang; Meyerspeer, Martin; Ukropec, Jozef; Frollo, Ivan; Ukropcová, Barbara; Trattnig, Siegfried; Krššák, Martin

    2014-11-01

    Dynamic (31) P-MRS with sufficiently high temporal resolution enables the non-invasive evaluation of oxidative muscle metabolism through the measurement of phosphocreatine (PCr) recovery after exercise. Recently, single-voxel localized (31) P-MRS was compared with surface coil localization in a dynamic fashion, and was shown to provide higher anatomical and physiological specificity. However, the relatively long TE needed for the single-voxel localization scheme with adiabatic pulses limits the quantification of J-coupled spin systems [e.g. adenosine triphosphate (ATP)]. Therefore, the aim of this study was to evaluate depth-resolved surface coil MRS (DRESS) as an alternative localization method capable of free induction decay (FID) acquisition for dynamic (31) P-MRS at 7 T. The localization performance of the DRESS sequence was tested in a phantom. Subsequently, two dynamic examinations of plantar flexions at 25% of maximum voluntary contraction were conducted in 10 volunteers, one examination with and one without spatial localization. The DRESS slab was positioned obliquely over the gastrocnemius medialis muscle, avoiding other calf muscles. Under the same load, significant differences in PCr signal drop (31.2 ± 16.0% versus 43.3 ± 23.4%), end exercise pH (7.06 ± 0.02 versus 6.96 ± 0.11), initial recovery rate (0.24 ± 0.13 mm/s versus 0.35 ± 0.18 mm/s) and maximum oxidative flux (0.41 ± 0.14 mm/s versus 0.54 ± 0.16 mm/s) were found between the non-localized and DRESS-localized data, respectively. Splitting of the inorganic phosphate (Pi) signal was observed in several non-localized datasets, but in none of the DRESS-localized datasets. Our results suggest that the application of the DRESS localization scheme yielded good spatial selection, and provided muscle-specific insight into oxidative metabolism, even at a relatively low exercise load. In addition, the non-echo-based FID acquisition allowed for reliable detection of ATP resonances, and therefore

  14. Characterizing phosphorus speciation of Chesapeake Bay sediments using chemical extraction, 31P NMR, and X-ray absorption fine structure spectroscopy.

    PubMed

    Li, Wei; Joshi, Sunendra R; Hou, Guangjin; Burdige, David J; Sparks, Donald L; Jaisi, Deb P

    2015-01-06

    Nutrient contamination has been one of the lingering issues in the Chesapeake Bay because the bay restoration is complicated by temporally and seasonally variable nutrient sources and complex interaction between imported and regenerated nutrients. Differential reactivity of sedimentary phosphorus (P) pools in response to imposed biogeochemical conditions can record past sediment history and therefore a detailed sediment P speciation may provide information on P cycling particularly the stability of a P pool and the formation of one pool at the expense of another. This study examined sediment P speciation from three sites in the Chesapeake Bay: (i) a North site in the upstream bay, (ii) a middle site in the central bay dominated by seasonally hypoxic bottom water, and (iii) a South site at the bay-ocean boundary using a combination of sequential P extraction (SEDEX) and spectroscopic techniques, including (31)P NMR, P X-ray absorption near edge structure spectroscopy (XANES), and Fe extended X-ray absorption fine structure (EXAFS). Results from sequential P extraction reveal that sediment P is composed predominantly of ferric Fe-bound P and authigenic P, which was further confirmed by solid-state (31)P NMR, XANES, and EXAFS analyses. Additionally, solution (31)P NMR results show that the sediments from the middle site contain high amounts of organic P such as monoesters and diesters, compared to the other two sites, but that these compounds rapidly decrease with sediment depth indicating remineralized P could have precipitated as authigenic P. Fe EXAFS enabled to identify the changes in Fe mineral composition and P sinks in response to imposed redox condition in the middle site sediments. The presence of lepidocrocite, vermiculite, and Fe smectite in the middle site sediments indicates that some ferric Fe minerals can still be present along with pyrite and vivianite, and that ferric Fe-bound P pool can be a major P sink in anoxic sediments. These results provide

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

    NASA Astrophysics Data System (ADS)

    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

  16. Genetic Variation in Myosin 1H Contributes to Mandibular Prognathism

    PubMed Central

    Tassopoulou-Fishell, Maria; Deeley, Kathleen; Harvey, Erika M.; Sciote, James; Vieira, Alexandre R.

    2013-01-01

    Introduction Several candidate loci have been suggested as influencing mandibular prognathism (1p22.1, 1p22.2, 1p36, 3q26.2, 5p13-p12, 6q25, 11q22.2-q22.3, 12q23, 12q13.13, and 19p13.2). The goal of this study was to replicate these results in a well-characterized homogeneous sample set. Methods Thirty-three single nucleotide polymorphisms spanning all candidate regions were studied in 44 prognathic and 35 Class I subjects from the University of Pittsburgh School of Dental Medicine Dental Registry and DNA Repository. The 44 mandibular prognathism subjects had an average age of 18.4 years, 31 were females and 13 males, and 24 were White, 15 African American, two Hispanic, and three Asian. The 35 Class I subjects had an average age of 17.6 years, 27 were females and 9 males, and 27 were White, six African Americans, one Hispanic, and two Asian. Skeletal mandibular prognathism diagnosis included cephalometric values indicative of Class III such as ANB smaller than two degrees, negative Witts appraisal, and positive A–B plane. Additional mandibular prognathism criteria included negative OJ and visually prognathic (concave) profile as determined by the subject's clinical evaluation. Orthognathic subjects without jaw deformations were used as a comparison group. Mandibular prognathism and orthognathic subjects were matched based on race, sex and age. Genetic markers were tested by polymerase chain reaction using TaqMan chemistry. Chi-square and Fisher exact tests were used to determine overrepresentation of marker allele with alpha of 0.05. Results An association was unveiled between a marker in MYO1H (rs10850110) and the mandibular prognathism phenotype (p=0.03). MYO1H is a Class-I myosin that is in a different protein group than the myosin isoforms of muscle sarcomeres, which are the basis of skeletal muscle fiber typing. Class I myosins are necessary for cell motility, phagocytosis and vesicle transport. Conclusions More strict clinical definitions may increase

  17. Brain temperature and pH measured by (1)H chemical shift imaging of a thulium agent.

    PubMed

    Coman, Daniel; Trubel, Hubert K; Rycyna, Robert E; Hyder, Fahmeed

    2009-02-01

    Temperature and pH are two of the most important physiological parameters and are believed to be tightly regulated because they are intricately related to energy metabolism in living organisms. Temperature and/or pH data in mammalian brain are scarce, however, mainly because of lack of precise and non-invasive methods. At 11.7 T, we demonstrate that a thulium-based macrocyclic complex infused through the bloodstream can be used to obtain temperature and pH maps of rat brain in vivo by (1)H chemical shift imaging (CSI) of the sensor itself in conjunction with a multi-parametric model that depends on several proton resonances of the sensor. Accuracies of temperature and pH determination with the thulium sensor - which has a predominantly extracellular presence - depend on stable signals during the course of the CSI experiment as well as redundancy for temperature and pH sensitivities contained within the observed signals. The thulium-based method compared well with other methods for temperature ((1)H MRS of N-acetylaspartate and water; copper-constantan thermocouple wire) and pH ((31)P MRS of inorganic phosphate and phosphocreatine) assessment, as established by in vitro and in vivo studies. In vitro studies in phantoms with two compartments of different pH value observed under different ambient temperature conditions generated precise temperature and pH distribution maps. In vivo studies in alpha-chloralose-anesthetized and renal-ligated rats revealed temperature (33-34 degrees C) and pH (7.3-7.4) distributions in the cerebral cortex that are in agreement with observations by other methods. These results show that the thulium sensor can be used to measure temperature and pH distributions in rat brain in vivo simultaneously and accurately using Biosensor Imaging of Redundant Deviation in Shifts (BIRDS).

  18. Crystal structure of 1H,1'H-[2,2'-biimid-azol]-3-ium hydrogen tartrate hemi-hydrate.

    PubMed

    Gao, Xiao-Li; Bian, Li-Fang; Guo, Shao-Wei

    2014-11-01

    In the crystal of the title hydrated salt, C6H7N4 (+)·C4H5O6 (-)·0.5H2O, the bi-imidazole monocation, 1H,1'H-[2,2'-biimidazol]-3-ium, is hydrogen bonded, via N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds, to the hydrogen tartrate anion and the water mol-ecule, which is located on a twofold rotation axis, forming sheets parallel to (001). The sheets are linked via C-H⋯O hydrogen bonds, forming a three-dimensional structure. There are also C=O⋯π inter-actions present [O⋯π distances are 3.00 (9) and 3.21 (7) Å], involving the carbonyl O atoms and the imidazolium ring, which may help to consolidate the structure. In the cation, the dihedral angle between the rings is 11.6 (2)°.

  19. One dimensional 1H, 2H and 3H

    NASA Astrophysics Data System (ADS)

    Vidal, A. J.; Astrakharchik, G. E.; Vranješ Markić, L.; Boronat, J.

    2016-05-01

    The ground-state properties of one-dimensional electron-spin-polarized hydrogen 1H, deuterium 2H, and tritium 3H are obtained by means of quantum Monte Carlo methods. The equations of state of the three isotopes are calculated for a wide range of linear densities. The pair correlation function and the static structure factor are obtained and interpreted within the framework of the Luttinger liquid theory. We report the density dependence of the Luttinger parameter and use it to identify different physical regimes: Bogoliubov Bose gas, super-Tonks-Girardeau gas, and quasi-crystal regimes for bosons; repulsive, attractive Fermi gas, and quasi-crystal regimes for fermions. We find that the tritium isotope is the one with the richest behavior. Our results show unambiguously the relevant role of the isotope mass in the properties of this quantum system.

  20. Observation of fatigue unrelated to gross energy reserve of skeletal muscle during tetanic contraction--an application of 31P-MRS.

    PubMed

    Takata, S; Takai, H; Ikata, T; Miura, I

    1988-11-30

    The mechanism of muscle fatigue was studied by 31P-MRS. During tetanic contraction for 2 minutes(min), the tension measured with a strain gauge and Phosphocreatine(PCr)/Inorganic phosphate(Pi)+ Phosphomonoester(PME) ratio decreased to 31.5 +/- 4.4% of the control value and 0.6 +/- 0.1, respectively. The intracellular pH(pH) also decreased to 6.62 +/- 0.04. Toward the end of the stimulation, the tension decreased to 25.3 +/- 1.9% of the control value. However, during 20min stimulation, the PCr/(Pi+PME) ratio increased to 2.5 +/- 0.5 and the pH to 6.91 +/- 0.04. These results show that muscular fatigue is ascribable not to a decreased level of high energy metabolites required for actomyosin ATPase, but to an increase in the threshold intensity of excitation in excitation-contraction coupling.

  1. Structural, optical and luminescence properties of Dy3+ doped bismuth phosphate glasses: Insights from 31P MAS NMR, absorption and photoluminescence

    NASA Astrophysics Data System (ADS)

    Damodaraiah, S.; Prasad, V. Reddy; Ratnakaram, Y. C.

    2017-05-01

    An investigation was carried out to observe structural and optical properties of 0.5 mol% Dy3+ doped different compositions of bismuth phosphate glasses (5, 10, 15 and 20 mol% Bi2O3). The structural characterization was accomplished by X-ray diffraction (XRD), 31P magic angle spin nuclear magnetic resonance (MAS NMR) spectroscopy. The optical properties were studied using absorption and photo luminescence (PL) spectroscopy. Judd-Ofelt intensity parameters Ωλ (λ=2, 4 and 6) were evaluated from absorption spectra. From photoluminescence spectra, experimental branching ratios (βexp) and stimulated emission cross-sections (σP) were calculated. The decay profiles for 4F9/2 level were recorded and were fit exponential. The obtained results show the prepared Dy3+ doped bismuth phosphate glasses might be useful as good optical material for yellow emission.

  2. 31P nuclear magnetic resonance measurements of phosphate metabolites and intracellular pH in turbot Psetta maxima red blood cells using a novel flow method.

    PubMed

    Thebault, M T; Pichavant, K; Kervarec, N

    2009-08-01

    A method for oxygenating and mixing suspensions of turbot Psetta maxima red blood cells (RBC) was tested in (31)P nuclear magnetic resonance (NMR) spectroscopy. In normoxia, the levels of inorganic phosphate (Pi) and nucleoside triphosphates (NTP) were stable up to 140 min and intracellular pH (pHi) was maintained and decreased oxygen partial pressure (P(O ( 2) )) from 30 to 15 and 600 Pa produced a significant fall in the intensity of NTP resonance, balanced by an increase in the Pi signal. Treatment of RBC with 0. 5 M isoproterenol during hypoxia exposure did not affect the pattern of changes in NTP or pHi induced by hypoxia and the effect was manifest only on Pi levels.

  3. Dynamic 31P MR spectroscopy of plantar flexion: influence of ergometer design, magnetic field strength (3 and 7 T), and RF-coil design.

    PubMed

    Šedivý, Petr; Kipfelsberger, Monika Christina; Dezortová, Monika; Krššák, Martin; Drobný, Miloslav; Chmelík, Marek; Rydlo, Jan; Trattnig, Siegfried; Hájek, Milan; Valkovič, Ladislav

    2015-04-01

    Dynamic phosphorus magnetic resonance spectroscopy ((31)P MRS) during and after acute exercise enables the noninvasive in vivo determination of the mitochondrial capacity of skeletal muscle. Nevertheless, the lack of standardization in experimental setups leads to significant variations in published values of maximal aerobic capacity, even in the population of healthy volunteers. Thus, in this study, we aimed to assess the impact of the ergometer type (pneumatic and mechanical resistance construction), radiofrequency (RF)-coil diameter, and different magnetic field strengths (3 and 7 T) on the metabolic parameters measured by dynamic (31)P MRS during a plantar flexion isotonic exercise protocol within the same group of healthy volunteers. Dynamic (31)P MRS measurements of the calf muscle in 11 volunteers (mean age, 36  ±  13 yrs; mean BMI, 23.5 ± 2.5 kg/m(2)), on a 3 T MR system with a custom-made mechanical ergometer in the first research laboratory (RL1) and on 3 and 7 T MR systems equipped with a commercial pneumatic ergometer in the second research laboratory (RL2), were performed at three different workloads. RF-coils differed slightly between the sites and MR systems used. The repeatability of the experimental protocol was tested in every setup. The basal concentrations of phosphocreatine (PCr), exercise-induced depletion of PCr (ΔPCr), initial PCr resynthesis rate (VPCr), and mitochondrial capacity (Qmax) were calculated and compared between the research sites and field strengths. High repeatability of the measurement protocol was found in every experimental setup. No significant differences at any workload were found in these metabolic parameters assessed at different magnetic field strengths (3 T vs 7 T), using the same ergometer (in RL2) and a similar RF-coil. In the inter-research laboratory comparison at the same field strength (3 T), but with using different ergometers and RF-coils, differences were found in the concentration of PCr measured at

  4. Structural and {sup 31}P NMR investigation of Bi(MM'){sub 2}PO{sub 6} statistic solid solutions: Deconvolution of lattice constraints and cationic influences

    SciTech Connect

    Colmont, Marie; Delevoye, Laurent; Ketatni, El Mostafa; Montagne, Lionel; Mentre, Olivier . E-mail: mentre@ensc-lille.fr

    2006-07-15

    Two solid solutions BiM{sub x} Mg{sub (2-x)}PO{sub 6} (with M {sup 2+}=Zn or Cd) have been studied through {sup 31}P MAS NMR. The analysis has been performed on the basis of refined crystal structures through X-ray diffraction and neutron diffraction. The BiZn {sub x} Mg{sub (2-x)}PO{sub 6} does not provide direct evidence for sensitive changes in the phosphorus local symmetry. This result is in good agreement with structural data which show nearly unchanged lattices and atomic separations through the Zn{sup 2+} for Mg{sup 2+} substitution. On the other hand, the Cd{sup 2+} for Mg{sup 2+} substitution behaves differently. Indeed, up to five resonances are observed, each corresponding to one of the five first-cationic neighbour distributions, i.e. 4Mg/0Cd, 3Mg/1Cd, 2Mg/2Cd, 1Mg/3Cd and 0Mg/4Cd. Their intensities match rather well the expected weight for each configuration of the statistical Cd{sup 2+}/Mg{sup 2+} mixed occupancy. The match is further improved when one takes into account the influence of the 2nd cationic sphere that is available from high-field NMR data (18.8 T). Finally, the fine examination of the chemical shift for each resonance versus x allows to de-convolute the mean Z/a {sup 2} effective field into two sub-effects: a lattice constraint-only term and a chemical-only term whose effects are directly quantifiable. - Graphical abstract: First (CdMg){sub 4} cationic sphere influence on the {sup 31}P NMR signal in Bi(Cd,Mg){sub 2}PO{sub 6}. Display Omitted.

  5. Effects of Coenzyme Q10 on Skeletal Muscle Oxidative Metabolism in Statin Users Assessed Using 31P Magnetic Resonance Spectroscopy: a Randomized Controlled Study

    PubMed Central

    Buettner, Catherine; Greenman, Robert L.; Ngo, Long H.; Wu, Jim S.

    2016-01-01

    Objectives Statins partially block the production of coenzyme Q10 (CoQ10), an essential component for mitochondrial function. Reduced skeletal muscle mitochondrial oxidative capacity has been proposed to be a cause of statin myalgia and can be measured using 31phosphorus magnetic resonance spectroscopy (31P-MRS). The purpose of this study is to assess the effect of CoQ10 oral supplementation on mitochondrial function in statin users using 31P-MRS. Design/Setting In this randomized, double-blind, placebo-controlled pilot study, 21 adults aged 47–73 were randomized to statin+placebo (n=9) or statin+CoQ10 (n=12). Phosphocreatine (PCr) recovery kinetics of calf muscles were assessed at baseline (off statin and CoQ10) and 4 weeks after randomization to either statin+CoQ10 or statin+placebo. Results Baseline and post-treatment PCr recovery kinetics were assessed for 19 participants. After 4 weeks of statin+ CoQ10 or statin+placebo, the overall relative percentage change (100*(baseline−follow up)/baseline) in PCr recovery time was −15.1% compared with baseline among all participants, (p-value=0.258). Participants randomized to statin+placebo (n=9) had a relative percentage change in PCr recovery time of −18.9%, compared to −7.7% among participants (n=10) receiving statin+CoQ10 (p-value=0.448). Conclusions In this pilot study, there was no significant change in mitochondrial function in patients receiving 4 weeks of statin+CoQ10 oral therapy when compared to patients on statin+placebo. PMID:27610419

  6. 31P NMR 2D Mapping of Creatine Kinase Forward Flux Rate in Hearts with Postinfarction Left Ventricular Remodeling in Response to Cell Therapy

    PubMed Central

    Gao, Ling; Cui, Weina; Zhang, Pengyuan; Jang, Albert; Zhu, Wuqiang; Zhang, Jianyi

    2016-01-01

    Utilizing a fast 31P magnetic resonance spectroscopy (MRS) 2-dimensional chemical shift imaging (2D-CSI) method, this study examined the heterogeneity of creatine kinase (CK) forward flux rate of hearts with postinfarction left ventricular (LV) remodeling. Immunosuppressed Yorkshire pigs were assigned to 4 groups: 1) A sham-operated normal group (SHAM, n = 6); 2) A 60 minutes distal left anterior descending coronary artery ligation and reperfusion (MI, n = 6); 3) Open patch group; ligation injury plus open fibrin patch over the site of injury (Patch, n = 6); and 4) Cell group, hiPSCs-cardiomyocytes, -endothelial cells, and -smooth muscle cells (2 million, each) were injected into the injured myocardium pass through a fibrin patch (Cell+Patch, n = 5). At 4 weeks, the creatine phosphate (PCr)/ATP ratio, CK forward flux rate (Flux PCr→ATP), and k constant of CK forward flux rate (kPCr→ATP) were severely decreased at border zone myocardium (BZ) adjacent to MI. Cell treatment results in significantly increase of PCr/ATP ratio and improve the value of kPCr→ATP and Flux PCr→ATP in BZ myocardium. Moreover, the BZ myocardial CK total activity and protein expression of CK mitochondria isozyme and CK myocardial isozyme were significantly reduced, but recovered in response to cell treatment. Thus, cell therapy results in improvement of BZ bioenergetic abnormality in hearts with postinfarction LV remodeling, which is accompanied by significantly improvements in BZ CK activity and CK isozyme expression. The fast 2D 31P MR CSI mapping can reliably measure the heterogeneity of bioenergetics in hearts with post infarction LV remodeling. PMID:27606901

  7. Dynamic in vivo (31)P nuclear magnetic resonance study of Saccharomyces cerevisiae in glucose-limited chemostat culture during the aerobic-anaerobic shift.

    PubMed

    Gonzalez, B; de Graaf, A; Renaud, M; Sahm, H

    2000-04-01

    The purpose of this work was to analyse in vivo the influence of sudden oxygen depletion on Saccharomyces cerevisiae, grown in glucose-limited chemostat culture, using a recently developed cyclone reactor coupled with (31)P NMR spectroscopy. Before, during and after the transition, intracellular and extracellular phosphorylated metabolites as well as the pHs in the different cellular compartments were monitored with a time resolution of 2.5 min. The employed integrated NMR bioreactor system allowed the defined glucose-limited continuous cultivation of yeast at a density of 75 g DW/l and a p(O(2)) of 30% air saturation. A purely oxidative metabolism was maintained at all times. In vivo (31)P NMR spectra obtained were of excellent quality and even allowed the detection of phosphoenolpyruvate (PEP). During the switch from aerobic to anaerobic conditions, a rapid, significant decrease of intracellular ATP and PEP levels was observed and the cytoplasmic pH decreased from 7.5 to 6.8. This change, which was accompanied by a transient influx of extracellular inorganic phosphate (P(i)), appeared to correlate linearly with the decrease of the ATP concentration, suggesting that the cause of the partial collapse of the plasma membrane pH gradient was a reduced availability of ATP. The complete phosphorous balance established from our measurement data showed that polyphosphate was not the source of the increased intracellular P(i). The derived intracellular P(i), ATP and ADP concentration data confirmed that the glycolytic flux at the level of glyceraldehyde-3-phosphate dehydrogenase, 3-phosphoglycerate kinase and enolase enzymes is mainly controlled by thermodynamic constraints.

  8. Mitochondria-targeted antioxidant promotes recovery of skeletal muscle mitochondrial function after burn trauma assessed by in vivo 31P nuclear magnetic resonance and electron paramagnetic resonance spectroscopy

    PubMed Central

    Righi, Valeria; Constantinou, Caterina; Mintzopoulos, Dionyssios; Khan, Nadeem; Mupparaju, S. P.; Rahme, Laurence G.; Swartz, Harold M.; Szeto, Hazel H.; Tompkins, Ronald G.; Tzika, A. Aria

    2013-01-01

    Burn injury causes a major systemic catabolic response that is associated with mitochondrial dysfunction in skeletal muscle. We investigated the effects of the mitochondria-targeted peptide antioxidant Szeto-Schiller 31 (SS-31) on skeletal muscle in a mouse burn model using in vivo phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy to noninvasively measure high-energy phosphate levels; mitochondrial aconitase activity measurements that directly correlate with TCA cycle flux, as measured by gas chromatography mass spectrometry (GC-MS); and electron paramagnetic resonance (EPR) to assess oxidative stress. At 6 h postburn, the oxidative ATP synthesis rate was increased 5-fold in burned mice given a single dose of SS-31 relative to untreated burned mice (P=0.002). Furthermore, SS-31 administration in burned animals decreased mitochondrial aconitase activity back to control levels. EPR revealed a recovery in redox status of the SS-31-treated burn group compared to the untreated burn group (P<0.05). Our multidisciplinary convergent results suggest that SS-31 promotes recovery of mitochondrial function after burn injury by increasing ATP synthesis rate, improving mitochondrial redox status, and restoring mitochondrial coupling. These findings suggest use of noninvasive in vivo NMR and complementary EPR offers an approach to monitor the effectiveness of mitochondrial protective agents in alleviating burn injury symptoms.—Righi, V., Constantinou, C., Mintzopoulos, D., Khan, N., Mupparaju, S. P., Rahme, L. G., Swartz, H. M., Szeto, H. H., Tompkins, R. G., and Tzika, A. A. Mitochondria-targeted antioxidant promotes recovery of skeletal muscle mitochondrial function after burn trauma assessed by in vivo 31P nuclear magnetic resonance and electron paramagnetic resonance spectroscopy. PMID:23482635

  9. In vitro (31)P NMR studies on biopsy skeletal muscle samples compared with meat quality of normal and heterozygous malignant hyperthermia pigs.

    PubMed

    Lahucky, R; Baulain, U; Henning, M; Demo, P; Krska, P; Liptaj, T

    2002-07-01

    Phosphorus nuclear magnetic resonance ((31)P NMR) measurements were made to determine muscle energetic metabolism on muscle biopsy samples of heterozygote malignant hyperthermia (Nn) and normal (NN) pigs DNA tested on occurrence of mutation in RYR 1 gene. Biopsy samples (approx. 1 g) were obtained by spring-loaded biopsy instrument (Biotech, Slovakia) from Longissimus dorsi (LD) muscle at 80 kg live weight. The spectra were recorded at 121 MHz on a VXR 300 (Varian) spectrometer in 10 mm diameter tube (maintained at 39 °C) for 50 min. pH of bioptates after NMR measurements were also measured at 60 min. The changes in inorganic phosphate (Pi), phosophocreatine (PCr) and adenosine triphosphate (ATP) were faster in heterozygote malignant hyperthermia (MH; 29 crossbred White Meaty×Pietrain) than in normal (13 Duroc, Yorkshire and White Meaty). The values of PCr at 20 min and pH at 60 min after taking biopsy allowed discrimination between NN and Nn pigs and significant (P<0.05) differences were also found between two subgroups in heterozygote MH pigs with different rate of post mortem muscle metabolism. The values of PCr and pH as measured at definite time on the biopsies, were significantly (P<0.05) correlated with the rate of post mortem metabolism (pH) and with meat quality traits (r approx. 0.4-0.6). The (31)P NMR measurements pointed to impaired muscle energetic metabolism connected with the occurrence of mutation on the RYR 1 gene in heterozygote MH pigs.

  10. Effect of glass-forming biopreservatives on head group rotational dynamics in freeze-dried phospholipid bilayers: a 31P NMR study.

    PubMed

    Jain, P; Sen, S; Risbud, S H

    2009-07-14

    (31)P NMR spectroscopy has been used to elucidate the role of glass-forming sugars in the preservation of dipalmitoylphosphatidylcholine (DPPC) lipid bilayers. (31)P wideline NMR spectra of freeze-dried pure DPPC, DPPC/trehalose, DPPC/glucose, and DPPC/hydroxyethyl starch (HES) mixtures collected in the temperature range of 25-80 degrees C have been simulated to obtain quantitative information about rotational dynamics and orientation of the lipid head groups in these media. In the case of pure DPPC, DPPC/glucose, and DPPC/HES, the gel-to-liquid crystalline phase transition of DPPC bilayer is characterized by a sudden increase in the rate of rotational diffusion of the PO(4) head groups near 40 degrees C. The corresponding rotational jump frequency increases from a few kilohertz in the gel phase to at least several megahertz in the liquid crystalline phase. On the other hand, in the case of DPPC/trehalose mixture the temperature of this onset of rapid head group dynamics is increased by approximately 10 degrees C. Trehalose reduces the lipid head group motions most effectively in the temperature range of T < or = 50 degrees C relevant for biopreservation. Additionally, and possibly more importantly, trehalose is found to strongly restrict any change in the orientation of the diffusion axis of the PO(4) head groups during the phase transformation. This unique ability of trehalose to maintain the dynamical and orientational rigidity of lipid head groups is likely to be responsible for its superior ability in biopreservation.

  11. Conformation and dynamics of melittin bound to magnetically oriented lipid bilayers by solid-state (31)P and (13)C NMR spectroscopy.

    PubMed Central

    Naito, A; Nagao, T; Norisada, K; Mizuno, T; Tuzi, S; Saitô, H

    2000-01-01

    The conformation and dynamics of melittin bound to the dimyristoylphosphatidylcholine (DMPC) bilayer and the magnetic orientation in the lipid bilayer systems were investigated by solid-state (31)P and (13)C NMR spectroscopy. Using (31)P NMR, it was found that melittin-lipid bilayers form magnetically oriented elongated vesicles with the long axis parallel to the magnetic field above the liquid crystalline-gel phase transition temperature (T(m) = 24 degrees C). The conformation, orientation, and dynamics of melittin bound to the membrane were further determined by using this magnetically oriented lipid bilayer system. For this purpose, the (13)C NMR spectra of site-specifically (13)C-labeled melittin bound to the membrane in the static, fast magic angle spinning (MAS) and slow MAS conditions were measured. Subsequently, we analyzed the (13)C chemical shift tensors of carbonyl carbons in the peptide backbone under the conditions where they form an alpha-helix and reorient rapidly about the average helical axis. Finally, it was found that melittin adopts a transmembrane alpha-helix whose average axis is parallel to the bilayer normal. The kink angle between the N- and C-terminal helical rods of melittin in the lipid bilayer is approximately 140 degrees or approximately 160 degrees, which is larger than the value of 120 degrees determined by x-ray diffraction studies. Pore formation was clearly observed below the T(m) in the initial stage of lysis by microscope. This is considered to be caused by the association of melittin molecules in the lipid bilayer. PMID:10777736

  12. Grey and white matter differences in brain energy metabolism in first episode schizophrenia: 31P-MRS chemical shift imaging at 4 Tesla.

    PubMed

    Jensen, J Eric; Miller, Jodi; Williamson, Peter C; Neufeld, Richard W J; Menon, Ravi S; Malla, Ashok; Manchanda, Rahul; Schaefer, Betsy; Densmore, Maria; Drost, Dick J

    2006-03-31

    Altered high energy and membrane metabolism, measured with phosphorus magnetic resonance spectroscopy (31P-MRS), has been inconsistently reported in schizophrenic patients in several anatomical brain regions implicated in the pathophysiology of this illness, with little attention to the effects of brain tissue type on the results. Tissue regression analysis correlates brain tissue type to measured metabolite levels, allowing for the extraction of "pure" estimated grey and white matter compartment metabolite levels. We use this tissue analysis technique on a clinical dataset of first episode schizophrenic patients and matched controls to investigate the effect of brain tissue specificity on altered energy and membrane metabolism. In vivo brain spectra from two regions, (a) the fronto-temporal-striatal region and (b) the frontal-lobes, were analyzed from 12 first episode schizophrenic patients and 11 matched controls from a (31)P chemical shift imaging (CSI) study at 4 Tesla (T) field strength. Tissue regression analyses using voxels from each region were performed relating metabolite levels to tissue content, examining phosphorus metabolite levels in grey and white matter compartments. Compared with controls, the first episode schizophrenic patient group showed significantly increased adenosine triphosphate levels (B-ATP) in white matter and decreased B-ATP levels in grey matter in the fronto-temporal-striatal region. No significant metabolite level differences were found in grey or white matter compartments in the frontal cortex. Tissue regression analysis reveals grey and white matter specific aberrations in high-energy phosphates in first episode schizophrenia. Although past studies report inconsistent regional differences in high-energy phosphate levels in schizophrenia, the present analysis suggests more widespread differences that seem to be strongly related to tissue type. Our data suggest that differences in grey and white matter tissue content between past

  13. Effect of chronic magnesium supplementation on magnesium distribution in healthy volunteers evaluated by 31P-NMRS and ion selective electrodes

    PubMed Central

    Wary, C; Brillault-Salvat, C; Bloch, G; Leroy-Willig, A; Roumenov, D; Grognet, J-M; Leclerc, J H; Carlier, P G

    1999-01-01

    Aims The role of magnesium (Mg) intake in the prevention and treatment of diseases is greatly debated. Mg biodistribution after chronic Mg supplementation was investigated, using state-of-the-art technology to detect changes in free ionized Mg, both at extra- and intracellular levels. Methods Thirty young healthy male volunteers participated in a randomised, placebo (P)-controlled, double-blind trial. The treated group (MgS) took 12 mmol magnesium lactate daily for 1 month. Subjects underwent in vivo31P-NMR spectroscopy and complete clinical and biological examinations, on the first and last day of the trial. Total Mg was measured in plasma, red blood cells and 24 h urine ([Mg]U). Plasma ionized Mg was measured by ion-selective electrodes. Intracellular free Mg concentrations of skeletal muscle and brain tissues were determined noninvasively by in vivo31P-NMR at 3T. NMR data were automatically processed with the dedicated software MAGAN. Results Only [Mg]U changed significantly after treatment (in mmol/24 h, for P, from 4.2±1.4 before to 4.1±1.3 after and, for MgS, from 3.9±1.1 before to 5.1±1.1 after, t =2.15, P =0.04). The two groups did not differ, either before or after the trial, in any other parameter, whether clinical, biological or in relation with the Mg status. Conclusions Chronic oral administration of Mg tablets to young healthy male volunteers at usual pharmaceutical doses does not alter Mg biodistribution. This study shows that an adequate and very complete noninvasive methodology is now available and compatible with the organization of clinical protocols which aim at a thorough evaluation of Mg biodistribution. PMID:10594466

  14. 31P Magnetic Resonance Spectroscopy Assessment of Muscle Bioenergetics as a Predictor of Gait Speed in the Baltimore Longitudinal Study of Aging.

    PubMed

    Choi, Seongjin; Reiter, David A; Shardell, Michelle; Simonsick, Eleanor M; Studenski, Stephanie; Spencer, Richard G; Fishbein, Kenneth W; Ferrucci, Luigi

    2016-12-01

    Aerobic fitness and muscle bioenergetic capacity decline with age; whether such declines explain age-related slowing of walking speed is unclear. We hypothesized that muscle energetics and aerobic capacity are independent correlates of walking speed in simple and challenging performance tests and that they account for the observed age-related decline in walking speed in these same tests. Muscle bioenergetics was assessed as postexercise recovery rate of phosphocreatine (PCr), k PCr, using phosphorus magnetic resonance spectroscopy ((31)P-MRS) in 126 participants (53 men) of the Baltimore Longitudinal Study of Aging aged 26-91 years (mean = 72 years). Four walking tasks were administered-usual pace over 6 m and 150 seconds and fast pace over 6 m and 400 m. Separately, aerobic fitness was assessed as peak oxygen consumption (peak VO2) using a graded treadmill test. All gait speeds, k PCr, and peak VO2 were lower with older age. Independent of age, sex, height, and weight, both k PCr and peak VO2 were positively and significantly associated with fast pace and long distance walking but only peak VO2 and not k PCr was significantly associated with usual gait speed over 6 m. Both k PCr and peak VO2 substantially attenuated the association between age and gait speed for all but the least stressful walking task of 6 m at usual pace. Muscle bioenergetics assessed using (31)P-MRS is highly correlated with walking speed and partially explains age-related poorer performance in fast and long walking tasks. Published by Oxford University Press on behalf of The Gerontological Society of America 2016. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  15. Complete (1)H and (13)C NMR chemical shift assignments of mono-, di-, and trisaccharides as basis for NMR chemical shift predictions of polysaccharides using the computer program casper.

    PubMed

    Roslund, Mattias U; Säwén, Elin; Landström, Jens; Rönnols, Jerk; Jonsson, K Hanna M; Lundborg, Magnus; Svensson, Mona V; Widmalm, Göran

    2011-08-16

    The computer program casper uses (1)H and (13)C NMR chemical shift data of mono- to trisaccharides for the prediction of chemical shifts of oligo- and polysaccharides. In order to improve the quality of these predictions the (1)H and (13)C, as well as (31)P when applicable, NMR chemical shifts of 30 mono-, di-, and trisaccharides were assigned. The reducing sugars gave two distinct sets of NMR resonances due to the α- and β-anomeric forms. In total 35 (1)H and (13)C NMR chemical shift data sets were obtained from the oligosaccharides. One- and two-dimensional NMR experiments were used for the chemical shift assignments and special techniques were employed in some cases such as 2D (1)H,(13)C-HSQC Hadamard Transform methodology which was acquired approximately 45 times faster than a regular t(1) incremented (1)H,(13)C-HSQC experiment and a 1D (1)H,(1)H-CSSF-TOCSY experiment which was able to distinguish spin-systems in which the target protons were only 3.3Hz apart. The (1)H NMR chemical shifts were subsequently refined using total line-shape analysis with the PERCH NMR software. The acquired NMR data were then utilized in the casper program (http://www.casper.organ.su.se/casper/) for NMR chemical shift predictions of the O-antigen polysaccharides from Klebsiella O5, Shigella flexneri serotype X, and Salmonella arizonae O62. The data were compared to experimental data of the polysaccharides from the two former strains and the lipopolysaccharide of the latter strain showing excellent agreement between predicted and experimental (1)H and (13)C NMR chemical shifts.

  16. Liver Metabolite Concentrations Measured with 1H MR Spectroscopy

    PubMed Central

    Pettigrew, Roderic I.; Gharib, Ahmed M.

    2012-01-01

    Purpose: To determine the feasibility of measuring choline and glycogen concentrations in normal human liver in vivo with proton (hydrogen 1 [1H]) magnetic resonance (MR) spectroscopy. Materials and Methods: Signed consent to participate in an institutional review board–approved and HIPAA-compliant study was obtained from 46 subjects (mean age, 46 years ± 17 [standard deviation]; 24 women) consecutively recruited during 285 days. Navigator-gated MR images were used to select 8-mL volumes for point-resolved spectroscopy (PRESS) with a 35-msec echo time. Line widths were minimized with fast breath-hold B0 field mapping and further manual shimming. Navigator-gated spectra were recorded with and without water suppression to determine metabolite concentrations with water signals as an internal reference. In three subjects, echo time was varied to determine the glycogen and choline T2. Linear regression analysis was used to examine relations between choline, hepatic lipid content, body mass index, glycogen content, and age. Results: Choline concentrations could be determined in 46 of 48 studies and was found to be 8.6 mmol per kilogram of wet weight ± 3.1 (range, 3.8–17.6; n = 44). Twenty-seven spectra in 25 individuals with narrow line widths and low lipid content were adequate for quantitation of glycogen. The glycogen (glucosyl unit) concentration was 38.1 mmol/kg wet weight ± 14.4. The T2 of combined glycogen peaks in the liver of three subjects was 36 msec ± 8. Choline levels showed a weak but significant correlation with glycogen (r2 = 0.15; P < .05) but not with lipid content. Conclusion: Navigator-gated and gradient-echo shimmed PRESS 1H MR spectroscopy may allow quantification of liver metabolites that are important for understanding and identifying disorders of glucose and lipid metabolism. © RSNA, 2012 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12112344/-/DC1 PMID:22891360

  17. Hexamethyldisiloxane-based nanoprobes for (1) H MRI oximetry.

    PubMed

    Gulaka, Praveen K; Rastogi, Ujjawal; McKay, Madalyn A; Wang, Xianghui; Mason, Ralph P; Kodibagkar, Vikram D

    2011-12-01

    Quantitative in vivo oximetry has been reported using (19) F MRI in conjunction with reporter molecules, such as perfluorocarbons, for tissue oxygenation (pO(2) ). Recently, hexamethyldisiloxane (HMDSO) has been proposed as a promising alternative reporter molecule for (1) H MRI-based measurement of pO(2) . To aid biocompatibility for potential systemic administration, we prepared various nanoemulsion formulations using a wide range of HMDSO volume fractions and HMDSO to surfactant ratios. Calibration curves (R(1) versus pO(2) ) for all emulsion formulations were found to be linear and similar to neat HMDSO for low surfactant concentrations (<10% v/v). A small temperature dependence in the calibration curves was observed, similar to previous reports on neat HMDSO, and was characterized to be approximately 1 Torr/ °C under hypoxic conditions. To demonstrate application in vivo, 100 µL of this nanoemulsion was administered to healthy rat thigh muscle (Fisher 344, n=6). Dynamic changes in mean thigh tissue pO(2) were measured using the PISTOL (proton imaging of siloxanes to map tissue oxygenation levels) technique in response to oxygen challenge. Changing the inhaled gas to oxygen for 30 min increased the mean pO(2) significantly (p<0.001) from 39 ± 7 to 275 ± 27 Torr. When the breathing gas was switched back to air, the tissue pO(2) decreased to a mean value of 45 ± 6 Torr, not significantly different from baseline (p>0.05), in 25 min. A first-order exponential fit to this part of the pO(2) data (i.e. after oxygen challenge) yielded an oxygen consumption-related kinetic parameter k=0.21 ± 0.04 min(-1) . These results demonstrate the feasibility of using HMDSO nanoemulsions as nanoprobes of pO(2) and their utility to assess oxygen dynamics in vivo, further developing quantitative (1) H MRI oximetry.

  18. 3-hydroxy-2(1H)-pyridinone chelating agents

    DOEpatents

    Raymond, Kenneth N.; Xu, Jide

    1997-01-01

    Disclosed is a series of improved metal chelating agents, which are highly effective upon both injection and oral administration; several of the most effective are of low toxicity. These chelating agents incorporate within their structure 1-hydroxy-2-pyridinone (1,2-HOPO) and 3-hydroxy-2-pyridinone (3,2-HOPO) moieties with a substituted carbamoyl group ortho to the hydroxy or oxo groups of the hydroxypyridinone ring. The electron-withdrawing carbamoyl group increases the acidity of the hydroxypyridinones. In the metal complexes of said chelating agents, the amide protons form very strong hydrogen bonds with its adjacent HOPO oxygen donor, making these complexes very stable at physiological conditions. The terminal N-substituents provides a certain degree of lipophilicity to said 3,2-HOPO, increasing oral activity. Also disclosed is a method of making the chelating agents and a method of producing a known compound, 3-hydroxy-1-alkyl-2(1H)pyridinone, used as a precursor to the chelating agent, safely and in large quantities.

  19. 1H NMR Metabolomics Analysis of Glioblastoma Subtypes

    PubMed Central

    Cuperlovic-Culf, Miroslava; Ferguson, Dean; Culf, Adrian; Morin, Pier; Touaibia, Mohamed

    2012-01-01

    Glioblastoma multiforme (GBM) is the most common form of malignant glioma, characterized by unpredictable clinical behaviors that suggest distinct molecular subtypes. With the tumor metabolic phenotype being one of the hallmarks of cancer, we have set upon to investigate whether GBMs show differences in their metabolic profiles. 1H NMR analysis was performed on metabolite extracts from a selection of nine glioblastoma cell lines. Analysis was performed directly on spectral data and on relative concentrations of metabolites obtained from spectra using a multivariate regression method developed in this work. Both qualitative and quantitative sample clustering have shown that cell lines can be divided into four groups for which the most significantly different metabolites have been determined. Analysis shows that some of the major cancer metabolic markers (such as choline, lactate, and glutamine) have significantly dissimilar concentrations in different GBM groups. The obtained lists of metabolic markers for subgroups were correlated with gene expression data for the same cell lines. Metabolic analysis generally agrees with gene expression measurements, and in several cases, we have shown in detail how the metabolic results can be correlated with the analysis of gene expression. Combined gene expression and metabolomics analysis have shown differential expression of transporters of metabolic markers in these cells as well as some of the major metabolic pathways leading to accumulation of metabolites. Obtained lists of marker metabolites can be leveraged for subtype determination in glioblastomas. PMID:22528487

  20. The Conformations and Structures of 1H-NONAFLUOROBUTANE

    NASA Astrophysics Data System (ADS)

    Fournier, Joseph A.; Bohn, Robert K.; Montgomery, John A.; , Jr.

    2012-06-01

    The all trans conformers of perfluorocarbons, unlike hydrocarbons, are helical with C-C-C-C dihedral angles about 1640. Fluorocarbons with H substitution can replace chlorofluorocarbons as propellants and compressor fluids without the disadvantage of causing ozone depletion in the upper atmosphere. 1H-perfluorobutane, CHF_2CF_2CF_2CF_3, has been studied by pulsed-jet Fourier transform microwave spectroscopy. The spectrum is very rich. Quantum chemical calculations identify five stable conformers with relative energies up to 1.1 kcal/mol. Thus far three conformers have been characterized and many lines remain unassigned. The assigned species have CCCCanti/CCCH gauche as well as the anti/anti and gauche/anti forms. Rotational constant values are 1428.9501(2) MHz, 593.323877(6) MHz, and 546.43578(6) MHz for the anti/gauche species, 1323.664(3) MHz, 617.6051(5) MHz for the ant/anti species, and 1066.9384(4) MHz, 768.4736(4) MHz, and 671.3145(4) MHz for the gauche/anti form.

  1. 3-hydroxy-2(1H)-pyridinone chelating agents

    DOEpatents

    Raymond, K.N.; Xu, J.

    1997-04-29

    Disclosed is a series of improved metal chelating agents, which are highly effective upon both injection and oral administration; several of the most effective are of low toxicity. These chelating agents incorporate within their structure 1-hydroxy-2-pyridinone (1,2-HOPO) and 3-hydroxy-2-pyridinone (3,2-HOPO) moieties with a substituted carbamoyl group ortho to the hydroxy or oxo groups of the hydroxypyridinone ring. The electron-withdrawing carbamoyl group increases the acidity of the hydroxypyridinones. In the metal complexes of the chelating agents, the amide protons form very strong hydrogen bonds with its adjacent HOPO oxygen donor, making these complexes very stable at physiological conditions. The terminal N-substituents provides a certain degree of lipophilicity to the 3,2-HOPO, increasing oral activity. Also disclosed is a method of making the chelating agents and a method of producing a known compound, 3-hydroxy-1-alkyl-2(1H)pyridinone, used as a precursor to the chelating agent, safely and in large quantities. 2 figs.

  2. Mapping of prostate cancer by 1H MRSI.

    PubMed

    Kobus, Thiele; Wright, Alan J; Scheenen, Tom W J; Heerschap, Arend

    2014-01-01

    In many studies, it has been demonstrated that (1)H MRSI of the human prostate has great potential to aid prostate cancer management, e.g. in the detection and localisation of cancer foci in the prostate or in the assessment of its aggressiveness. It is particularly powerful in combination with T2 -weighted MRI. Nevertheless, the technique is currently mainly used in a research setting. This review provides an overview of the state-of-the-art of three-dimensional MRSI, including the specific hardware required, dedicated data acquisition sequences and information on the spectral content with background on the MR-visible metabolites. In clinical practice, it is important that relevant MRSI results become available rapidly, reliably and in an easy digestible way. However, this functionality is currently not fully available for prostate MRSI, which is a major obstacle for routine use by inexperienced clinicians. Routine use requires more automation in the processing of raw data than is currently available. Therefore, we pay specific attention in this review on the status and prospects of the automated handling of prostate MRSI data, including quality control. The clinical potential of three-dimensional MRSI of the prostate is illustrated with literature examples on prostate cancer detection, its localisation in the prostate, its role in the assessment of cancer aggressiveness and in the selection and monitoring of therapy.

  3. Preliminary 1H NMR study on archaeological waterlogged wood.

    PubMed

    Maccotta, Antonella; Fantazzini, Paola; Garavaglia, Carla; Donato, Ines D; Perzia, Patrizia; Brai, Maria; Morreale, Filippa

    2005-01-01

    Magnetic Resonance Relaxation (MRR) and Magnetic Resonance Imaging (MRI) are powerful tools to obtain detailed information on the pore space structure that one is unlikely to obtain in other ways. These techniques are particularly suitable for Cultural Heritage materials, because they use water 1H nuclei as a probe. Interaction with water is one of the main causes of deterioration of materials. Porous structure in wood, for example, favours the penetration of water, which can carry polluting substances and promote mould growth. A particular case is waterlogged wood from underwater discoveries and moist sites; in fact, these finds are very fragile because of chemical, physical and biological decay from the long contact with the water. When wood artefacts are brought to the surface and directly dried in air, there is the collapse of the cellular structures, and wood loses its original form and dimensions and cannot be used for study and museum exhibits. In this work we have undertaken the study of some wood finds coming from Ercolano's harbour by MRR and MRI under different conditions, and we have obtained a characterization of pore space in wood and images of the spatial distribution of the confined water in the wood.

  4. Effect of Oxygen Concentration on Viability and Metabolism in a Fluidized-Bed Bioartificial Liver Using 31P and 13C NMR Spectroscopy

    PubMed Central

    Jeffries, Rex E.; Gamcsik, Michael P.; Keshari, Kayvan R.; Pediaditakis, Peter; Tikunov, Andrey P.; Young, Gregory B.; Lee, Haakil; Watkins, Paul B.

    2013-01-01

    Many oxygen mass-transfer modeling studies have been performed for various bioartificial liver (BAL) encapsulation types; yet, to our knowledge, there is no experimental study that directly and noninvasively measures viability and metabolism as a function of time and oxygen concentration. We report the effect of oxygen concentration on viability and metabolism in a fluidized-bed NMR-compatible BAL using in vivo 31P and 13C NMR spectroscopy, respectively, by monitoring nucleotide triphosphate (NTP) and 13C-labeled nutrient metabolites, respectively. Fluidized-bed bioreactors eliminate the potential channeling that occurs with packed-bed bioreactors and serve as an ideal experimental model for homogeneous oxygen distribution. Hepatocytes were electrostatically encapsulated in alginate (avg. diameter, 500 μm; 3.5×107 cells/mL) and perfused at 3 mL/min in a 9-cm (inner diameter) cylindrical glass NMR tube. Four oxygen treatments were tested and validated by an in-line oxygen electrode: (1) 95:5 oxygen:carbon dioxide (carbogen), (2) 75:20:5 nitrogen:oxygen:carbon dioxide, (3) 60:35:5 nitrogen:oxygen:carbon dioxide, and (4) 45:50:5 nitrogen:oxygen:carbon dioxide. With 20% oxygen, β-NTP steadily decreased until it was no longer detected at 11 h. The 35%, 50%, and 95% oxygen treatments resulted in steady β-NTP levels throughout the 28-h experimental period. For the 50% and 95% oxygen treatment, a 13C NMR time course (∼5 h) revealed 2-13C-glycine and 2-13C-glucose to be incorporated into [2-13C-glycyl]glutathione (GSH) and 2-13C-lactate, respectively, with 95% having a lower rate of lactate formation. 31P and 13C NMR spectroscopy is a noninvasive method for determining viability and metabolic rates. Modifying tissue-engineered devices to be NMR compatible is a relatively easy and inexpensive process depending on the bioreactor shape. PMID:22835003

  5. Characteristics of phosphorus components in surface sediments from a Chinese shallow eutrophic lake (Lake Taihu): new insights from chemical extraction and (31)P NMR spectroscopy.

    PubMed

    Zhang, Runyu; Chen, Jingan; Wang, Liying; Wu, Fengchang

    2017-08-28

    As a primary factor responsible for lake eutrophication, a deeper understanding of the phosphorus (P) composition and its turnover in sediment is urgently needed. In this study, P species in surface sediments from a Chinese large eutrophic lake (Lake Taihu) were characterized by traditional fractionation and (31)P nuclear magnetic resonance (NMR) spectroscopy, and their contributions to the overlying water were also discussed. Fractionation results show that NaOH-P predominated in the algal-dominated zone, accounting for 60.1% to total P in Zhushan Bay. Whereas, refractory fractions including HCl-P and residual-P were the main P burial phases in the macrophyte-dominated zone, the center and lakeshore. Recovery rates of the total P and organic P were greatly improved by using a modified single-step extraction of NaOH-EDTA, ranging from 22.6 to 66.1% and from 15.0 to 54.0%. Ortho-P, monoester-P, and pyro-P are identified as the major P components in the NaOH-EDTA extracts by (31)P NMR analysis. Trace amount of DNA-P appeared only in sediments from algal- and macrophyte-dominated zones, ascribing to its biological origin. The relative content of ortho-P is the highest in the algal-dominated zone, while the biogenic P including ester-P and pyro-P is the highest in the macrophyte-dominated zone. Moreover, ortho-P and pyro-P correlated positively with TP and chlorophyll a in the overlying water, whereas only significant relationships were found between monoester-P, biogenic P, and chlorophyll a. These discrepancies imply that inorganic P, mainly ortho-P, plays a vital role in sustaining the trophic level of water body and algal bloom, while biogenic P makes a minor contribution to phytoplankton growth. This conclusion was supported by the results of high proportion of biogenic P in algae, aquatic macrophytes, and suspended particulate from the published literature. This study has significant implication for better understanding of the biogeochemical cycling of endogenous

  6. The reproducibility of different metabolic markers for muscle fiber type distributions investigated by functional (31)P-MRS during dynamic exercise.

    PubMed

    Rzanny, Reinhard; Stutzig, Norman; Hiepe, Patrick; Gussew, Alexander; Thorhauer, Hans-Alexander; Reichenbach, Jürgen R

    2016-12-01

    The objective of the study was to investigate the reproducibility of exercise induced pH-heterogeneity by splitting of the inorganic phosphate (Pi) signal in the corresponding (31)P-MRS spectra and to compare results of this approach with other fiber-type related markers, like phosphocreatine/adenosine triphosphate (PCr/ATP) ratio, and PCr-recovery parameters. Subjects (N=3) with different sportive background were tested in 10 test sessions separated by at least 3 days. A MR-compatible pedal ergometer was used to perform the exercise and to induce a pH-based splitting of the Pi-signal in (31)P-MR spectra of the medial gastrocnemius muscle. The PCr recovery was analyzed using a non-negative least square algorithm (NNLS) and multi-exponential regression analysis to estimate the number of non-exponential components as well as their amplitude and time constant. The reproducibility of the estimated metabolic marker and the resulting fiber-type distributions between the 10 test sessions were compared. The reproducibility (standard deviation between measurements) based on (1) Pi components varied from 2% to 4%, (2) PCr recovery time components varied from 10% to 12% and (3) phosphate concentrations at rest varied from 8% to 11% between test sessions. Due to the sportive activity differences between the 3 subjects were expected in view of fiber type distribution. All estimated markers indicate the highest type I percentage for volunteer 3 medium for volunteer 2 and the lowest for volunteer 1. The relative high reproducibility of pH dependent Pi components during exercise indicates a high potential of this method to estimate muscle fiber-type distributions in vivo. To make this method usable not only to detect differences in muscle fiber distributions but also to determine individual fiber-type volume contents it is therefore recommended to validate this marker by histological methods and to reveal the effects of muscle fiber recruitments and fiber-type specific Pi

  7. Phosphide oxides RE2AuP2O (RE = La, Ce, Pr, Nd): synthesis, structure, chemical bonding, magnetism, and 31P and 139La solid state NMR.

    PubMed

    Bartsch, Timo; Wiegand, Thomas; Ren, Jinjun; Eckert, Hellmut; Johrendt, Dirk; Niehaus, Oliver; Eul, Matthias; Pöttgen, Rainer

    2013-02-18

    Polycrystalline samples of the phosphide oxides RE(2)AuP(2)O (RE = La, Ce, Pr, Nd) were obtained from mixtures of the rare earth elements, binary rare earth oxides, gold powder, and red phosphorus in sealed silica tubes. Small single crystals were grown in NaCl/KCl fluxes. The samples were studied by powder X-ray diffraction, and the structures were refined from single crystal diffractometer data: La(2)AuP(2)O type, space group C2/m, a = 1515.2(4), b = 424.63(8), c = 999.2(2) pm, β = 130.90(2)°, wR2 = 0.0410, 1050 F(2) values for Ce(2)AuP(2)O, and a = 1503.6(4), b = 422.77(8), c = 993.0(2) pm, β = 130.88(2)°, wR2 = 0.0401, 1037 F(2) values for Pr(2)AuP(2)O, and a = 1501.87(5), b = 420.85(5), c = 990.3(3) pm, β = 131.12(1)°, wR2 = 0.0944, 1143 F(2) values for Nd(2)AuP(2)O with 38 variables per refinement. The structures are composed of [RE(2)O](4+) polycationic chains of cis-edge-sharing ORE(4/2) tetrahedra and polyanionic strands [AuP(2)](4-), which contain gold in almost trigonal-planar phosphorus coordination by P(3-) and P(2)(4-) entities. The isolated phosphorus atoms and the P(2) pairs in La(2)AuP(2)O could clearly be distinguished by (31)P solid state NMR spectroscopy and assigned on the basis of a double quantum NMR technique. Also, the two crystallographically inequivalent La sites could be distinguished by static (139)La NMR in conjunction with theoretical electric field gradient calculations. Temperature-dependent magnetic susceptibility measurements show diamagnetic behavior for La(2)AuP(2)O. Ce(2)AuP(2)O and Pr(2)AuP(2)O are Curie-Weiss paramagnets with experimental magnetic moments of 2.35 and 3.48 μ(B) per rare earth atom, respectively. Their solid state (31)P MAS NMR spectra are strongly influenced by paramagnetic interactions. Ce(2)AuP(2)O orders antiferromagnetically at 13.1(5) K and shows a metamagnetic transition at 11.5 kOe. Pr(2)AuP(2)O orders ferromagnetically at 7.0 K.

  8. Energy metabolism of the untrained muscle of elite runners as observed by 31P magnetic resonance spectroscopy: evidence suggesting a genetic endowment for endurance exercise.

    PubMed Central

    Park, J H; Brown, R L; Park, C R; Cohn, M; Chance, B

    1988-01-01

    The purpose of this study was to investigate whether genetically determined properties of muscle metabolism contribute to the exceptional physical endurance of world-class distance runners. ATP, phosphocreatine, inorganic phosphate, and pH were quantitatively determined by 31P nuclear magnetic resonance spectroscopy in the wrist flexor muscles of elite long-distance runners and sedentary control subjects. These muscles had not been exposed to any specific program of exercise training in either group of subjects. The "untrained" muscles were examined at rest, during two cycles of three grades of exercise, and in recovery. The flexor muscles of the athletes had higher concentrations of phosphocreatine and ATP than did those of the control subjects at rest and during exercise. The athletes' muscles possessed a higher capacity for generation of ATP by oxidative metabolism than did control subjects' muscles according to the following criteria: (i) high force output, 60% of maximum voluntary contraction, was more easily reached and better maintained in both exercise cycles; (ii) the ratio of inorganic phosphate to phosphocreatine rose less during exercise and recovered faster in the postexercise period; (iii) there was no loss of adenine nucleotides or total phosphate from the athletes' muscles but significant losses from the control subjects' muscles; and (iv) the pH decreased no more than 0.1 unit in the athletes' muscles during exercise, attesting to a relatively slow glycolysis and/or a rapid oxidation of lactate. In the muscles of the control subjects, on the other hand, the pH decreased nearly 0.4 unit early in the first exercise cycle, indicating a relatively fast glycolysis and/or slower oxidation of lactate. In the second exercise cycle, the pH returned to near normal in the control subjects' muscles, reflecting diminished lactate formation because of glycogen depletion and lactate washout by the high blood flow induced by exercise. By the end of the exercise

  9. Non-polymeric asymmetric binary glass-formers. II. Secondary relaxation studied by dielectric, 2H NMR, and 31P NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Pötzschner, B.; Mohamed, F.; Bächer, C.; Wagner, E.; Lichtinger, A.; Bock, D.; Kreger, K.; Schmidt, H.-W.; Rössler, E. A.

    2017-04-01

    We investigate the secondary (β-) relaxations of an asymmetric binary glass former consisting of a spirobichroman derivative (SBC; Tg = 356 K) as the high-Tg component and the low-Tg component tripropyl phosphate (TPP; Tg = 134 K). The main relaxations are studied in Paper I [B. Pötzschner et al., J. Chem. Phys. 146, 164503 (2017)]. A high Tg contrast of ΔTg = 222 K is put into effect in a non-polymeric system. Component-selective studies are carried out by combining results from dielectric spectroscopy (DS) for mass concentrations cTPP ≥ 60% and those from different methods of 2H and 31P NMR spectroscopy. In the case of NMR, the full concentration range (10% ≤ cTPP ≤ 100%) is covered. The neat components exhibit a β-relaxation (β1 (SBC) and β2 (TPP)). The latter is rediscovered by DS in the mixtures for all concentrations with unchanged time constants. NMR spectroscopy identifies the β-relaxations as being alike to those in neat glasses. A spatially highly restricted motion with angular displacement below ±10° encompassing all molecules is involved. In the low temperature range, where TPP shows the typical 31P NMR echo spectra of the β2-process, very similar spectral features are observed for the (deuterated) SBC component by 2H NMR, in addition to its "own" β1-process observed at high temperatures. Apparently, the small TPP molecules enslave the large SBC molecules to perform a common hindered reorientation. The temperature dependence of the spin-lattice relaxation time of both components is the same and reveals an angular displacement of the SBC molecules somewhat smaller than that of TPP, though the time constants τβ2 are the same. Furthermore, T1(T) of TPP in the temperature region of the β2-process is absolutely the same as in the mixture TPP/polystyrene investigated previously. It appears that the manifestations of the β-process introduced by one component are essentially independent of the second component. Finally, at cTPP ≤ 20% one

  10. Early estrogen-induced metabolic changes and their inhibition by actinomycin D and cycloheximide in human breast cancer cells: sup 31 P and sup 13 C NMR studies

    SciTech Connect

    Neeman, M.; Degani, H. )

    1989-07-01

    Metabolic changes following estrogen stimulation and the inhibition of these changes in the presence of actinomycin D and cycloheximide were monitored continuously in perfused human breast cancer T47D clone 11 cells with {sup 31}P and {sup 13}C NMR techniques. The experiments were performed by estrogen rescue of tamoxifen-treated cells. Immediately after perfusion with estrogen-containing medium, a continuous enhancement in the rates of glucose consumption, lactate production by glycolysis, and glutamate synthesis by the Krebs cycle occurred with a persistent 2-fold increase at 4 hr. Pretreatment with either actinomycin D or cycloheximide, at concentrations known to inhibit mRNA and protein synthesis, respectively, and simultaneous treatment with estrogen and each inhibitor prevented the estrogen-induced changes in glucose metabolism. This suggested that the observed estrogen stimulation required synthesis of mRNA and protein. These inhibitors also modulated several metabolic activities that were not related to estrogen stimulation. The observed changes in the in vivo kinetics of glucose metabolism may provide a means for the early detection of the response of human breast cancer cells to estrogen versus tamoxifen treatment.

  11. The Vps13p–Cdc31p complex is directly required for TGN late endosome transport and TGN homotypic fusion

    PubMed Central

    De, Mithu; Oleskie, Austin N.; Ayyash, Mariam; Dutta, Somnath; Mancour, Liliya; Brace, Eddy J.; Skiniotis, Georgios

    2017-01-01

    Yeast VPS13 is the founding member of a eukaryotic gene family of growing interest in cell biology and medicine. Mutations in three of four human VPS13 genes cause autosomal recessive neurodegenerative or neurodevelopmental disease, making yeast Vps13p an important structural and functional model. Using cell-free reconstitution with purified Vps13p, we show that Vps13p is directly required both for transport from the trans-Golgi network (TGN) to the late endosome/prevacuolar compartment (PVC) and for TGN homotypic fusion. Vps13p must be in complex with the small calcium-binding protein Cdc31p to be active. Single-particle electron microscopic analysis of negatively stained Vps13p indicates that this 358-kD protein is folded into a compact rod-shaped density (20 × 4 nm) with a loop structure at one end with a circular opening ∼6 nm in diameter. Vps13p exhibits ATP-stimulated binding to yeast membranes and specific interactions with phosphatidic acid and phosphorylated forms of phosphatidyl inositol at least in part through the binding affinities of conserved N- and C-terminal domains. PMID:28122955

  12. Effect of sugars on headgroup mobility in freeze-dried dipalmitoylphosphatidylcholine bilayers: solid-state 31P NMR and FTIR studies.

    PubMed Central

    Tsvetkova, N M; Phillips, B L; Crowe, L M; Crowe, J H; Risbud, S H

    1998-01-01

    The effect of the carbohydrates trehalose, glucose, and hydroxyethyl starch (HES) on the motional properties of the phosphate headgroup of freeze-dried dipalmitoylphosphatidylcholine (DPPC) liposomes was studied by means of 31P NMR, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). The results show that trehalose, which is a strong glass former (Tg = 115 degreesC), elevates the onset of the lipid headgroup rotations and preserves some rotational mobility of the phosphate headgroups after cooling from the liquid-crystalline state. Glucose (Tg = 30 degreesC), a very effective depressant of the phase transition temperature of freeze-dried DPPC, markedly elevates the initiation of the temperature of headgroup rotations. On the other hand, the monosaccharide does not preserve the headgroup disordering when cooled from the liquid-crystalline state. These effects are consistent with formation of hydrogen bonds between the OH groups of the sugar and the polar headgroups of DPPC. They show, however, that hydrogen bonding is not sufficient for preservation of the dynamic properties of freeze-dried DPPC. HES, although a very good glass former (Tg > 110 degreesC), does not depress the phase transition temperature and affects only slightly the rotational properties of freeze-dried DPPC. This lack of effect of HES is associated with the absence of direct interactions with the lipid phosphates, as evidenced by the FTIR results. These data show that vitrification of the additive is not sufficient to affect the dynamic properties of dried DPPC. PMID:9826615

  13. Time Averaging and Fitting of Nonlinear Metabolic Changes: The Issue of the Time Index Choice Applied to 31P MRS Investigation of Muscle Energetics

    NASA Astrophysics Data System (ADS)

    Simond, G.; Bendahan, D.; Cozzone, P. J.

    2001-03-01

    We present an exact analytical method dedicated to fitting time-dependent exponential-like changes in MR spectra. As an illustration, this method has been applied to fitting metabolic changes recorded by 31P MRS in human skeletal muscle occurring during a rest-exercise-recovery protocol. When recording metabolic changes with the accumulative method, the time averaging of the MR signals implies the choice of a time index for fitting any changes in the features of the associated MR spectra. A critical examination of the different ways (constant, linear, and exponential) of choosing the time index is reported. By numerical analysis, we have calculated the errors generated by the three methods and we have compared their sensitivity to noise. In the case of skeletal muscle, both constant and linear methods introduce large and uncontrolled errors for the whole set of metabolic parameters derived from [PCr] changes. In contrast, the exponential method affords a reliable estimation of critical parameters in muscle bioenergetics in both normal and pathological situations. This method is very easy to implement and provides an exact analytical solution to fitting changes in MR spectra recorded by the accumulative method.

  14. Concurrent quantification of tissue metabolism and blood flow via 2H/31P NMR in vivo. III. Alterations of muscle blood flow and metabolism during sepsis.

    PubMed

    Song, S K; Hotchkiss, R S; Karl, I E; Ackerman, J J

    1992-05-01

    In the conclusion of this series of reports, the application of 31P/2H NMR to investigate the pathophysiology of sepsis in rat hindlimb muscle is demonstrated. Sepsis decreased muscle [PCr] by 18%, 18 +/- 4 SD vs 22 +/- 4 SD mmol/kg tissue wet wt (P = 0.01) in control rats but [ATP] was unchanged, 6 mmol/kg tissue wet wt (P = 0.2). The derived free cytosolic [ADP] in the two groups was similar, [ADP]septic = 0.023 +/- 0.004 SD and [ADP]control = 0.021 +/- 0.003 SD mmol/kg tissue wet wt, and not statistically different (P = 0.14). Likewise [Pi] in the septic and control groups was not statistically different, [Pi]septic = 1.1 +/- 0.5 SD and [Pi]control = 1.2 +/- 0.4 SD mmol/kg tissue wet wt (P = 0.2). Septic rats presented the symptom of respiratory alkalosis evidenced by elevated blood pH. Sepsis decreased muscle blood flow by 33%, P = 0.003, but examination of individual subjects did not demonstrate a correlation with the reduction in [PCr]. Thus, a metabolic energy deficit caused by cellular ischemia/hypoxia is not a likely cause of cellular abnormality in rat hindlimb muscle during sepsis.

  15. Studies of vanadium-phosphorus-oxygen selective oxidation catalysts by sup 31 P and sup 51 V NMR spin-echo and volume susceptibility measurements

    SciTech Connect

    Li, Juan.

    1991-10-01

    The purpose of this work is to characterize the vanadium-phosphorous oxide (V-P-O) catalysts for the selective oxidation of n-butane and 1-butene to maleic anhydride. The utility of solid state nuclear magnetic resonance as an analytical tool in this investigation lies in its sensitivity to the electronic environment surrounding the phosphorous and vanadium nuclei, and proximity of paramagnetic species. Spin-echo mapping NMR of {sup 31}p and {sup 51}v and volume magnetic susceptibility measurements were used as local microscopic probes of the presence of V{sup 5+}, V{sup 4+}, V{sup 3+} species in the model compounds: {beta}-VOPO{sub 4}, {beta}-VOPO{sub 4} treated with n-butane/1-butene, (VO){sub 2}P{sub 2}O{sub 7} treated with n-butane/1-butene; and industrial catalysts with P/V (phosphorus to vanadium) ratio of 0.9, 1.0 and 1.1, before and after treatment with n-butane and 1-butene. The NMR spectra provide a picture of how the oxidation states of vanadium are distributed in these catalysts. 73 refs., 32 figs., 8 tabs.

  16. Insulin Resistance Is Associated With Reduced Mitochondrial Oxidative Capacity Measured by 31P-Magnetic Resonance Spectroscopy in Participants Without Diabetes From the Baltimore Longitudinal Study of Aging.

    PubMed

    Fabbri, Elisa; Chia, Chee W; Spencer, Richard G; Fishbein, Kenneth W; Reiter, David A; Cameron, Donnie; Zane, Ariel C; Moore, Zenobia A; Gonzalez-Freire, Marta; Zoli, Marco; Studenski, Stephanie A; Kalyani, Rita R; Egan, Josephine M; Ferrucci, Luigi

    2017-01-01

    Whether individuals with insulin resistance (IR) but without criteria for diabetes exhibit reduced mitochondrial oxidative capacity is unclear; addressing this question could guide research for new therapeutics. We investigated 248 participants without diabetes from the Baltimore Longitudinal Study of Aging (BLSA) to determine whether impaired mitochondrial capacity is associated with prediabetes, IR, and duration and severity of hyperglycemia exposure. Mitochondrial capacity was assessed as the postexercise phosphocreatine recovery time constant (τPCr) by (31)P-magnetic resonance spectroscopy, with higher τPCr values reflecting reduced capacity. Prediabetes was defined using the American Diabetes Association criteria from fasting and 2-h glucose measurements. IR and sensitivity were calculated using HOMA-IR and Matsuda indices. The duration and severity of hyperglycemia exposure were estimated as the number of years from prediabetes onset and the average oral glucose tolerance test (OGTT) 2-h glucose measurement over previous BLSA visits. Covariates included age, sex, body composition, physical activity, and other confounders. Higher likelihood of prediabetes, higher HOMA-IR, and lower Matsuda index were associated with longer τPCr. Among 205 participants with previous OGTT data, greater severity and longer duration of hyperglycemia were independently associated with longer τPC In conclusion, in individuals without diabetes a more impaired mitochondrial capacity is associated with greater IR and a higher likelihood of prediabetes.

  17. Reemergent phase of antiferromagnetic order in iron-based superconductor LaFe(As1-xPx)O probed by 31P-NMR

    NASA Astrophysics Data System (ADS)

    Engetsu, F.; Shiota, T.; Lai, K. T.; Mukuda, H.; Yashima, M.; Kitaoka, Y.; Miyasaka, S.; Tajima, S.

    2015-03-01

    We report 31P-NMR studies of LaFe(As1-xPx)O compounds that revealed the reemergence of a novel antiferromagnetic(AFM) order phase (AFM2) at 0.4 <= x <= 0.7 intervening between two superconductivity phases. The AFM2 state at x=0.6 is characterized by low Néel temperature TN = 35 K and small AFM moment ~0.18μB, which is in strong contrast to the AFM order phase(AFMl) at x=0 with larger AFM moment and higher TN. This finding provides a reasonable explanation for the previous experimental fact that the AFM spin fluctuations and Tc are unexpectedly enhanced in x=0.6 of LaFe(As1-xPx)(O0.95F0.05) even though its lattice parameters deviate from the optimum values, that is, the AFM spin fluctuations at low energies are enhanced as a result of the depression of AFM2 by electron doping through fluorine substitution.

  18. Superconductivity and Antiferromagnetic Spin Fluctuations in LaFe(As1-xPx)(O1-yFy) probed by 31P-NMR

    NASA Astrophysics Data System (ADS)

    Shiota, T.; Mukuda, H.; Uekubo, M.; Engetsu, F.; Yashima, M.; Kitaoka, Y.; Lai, K. T.; Usui, H.; Kuroki, K.; Miyasaka, S.; Tajima, S.

    2017-04-01

    31P-NMR study on LaFe(As1-xPx)(O0.86F0.14) unraveled that antiferromagnetic spin fluctuations (AFMSFs) emerge significantly at x=0.4 where the Tc is markedly enhanced, indicating that the AFMSFs are one of the important factors for raising Tc. From extensive comparison over wide compositions for 0 ≤ x ≤1 and 0 ≤ y ≤ 0.14, we revealed that there are two different types in temperature evolution of the AFMSFs: One is enhanced particularly at low energies that evolves only at low temperatures, which mainly derives from the two orbitals of dxz/yz. The other is distributed broadly at finite energies that appears up to high temperatures, which derives from three orbitals of dxy and dxz/yz. The highest Tc(=27 K) state in the present compositions appears at (x, y)=(0.4, 0.1) where two characteristics of AFMSFs merge, suggesting the contribution of the AFMSFs over wide energies to the onset of SC. The nonmonotonic variation of Tc in LaFe(As1-xPx)(O1-yFy) is attributed to the AFMSFs from degenarated multiple-3d-orbitals on iron-pnictide superconductors.

  19. Integrating muscle cell biochemistry and whole-body physiology in humans:31P-MRS data from the InSight trial

    PubMed Central

    Edwards, Lindsay M.; Kemp, Graham J.; Dwyer, Renee M.; Walls, Justin T.; Fuller, Huddy; Smith, Steven R.; Earnest, Conrad P.

    2013-01-01

    We acquired 31P-MRS data from skeletal muscle of subjects of mixed gender and ethnicity, combined with a panel of physiological characteristics, and tested several long-standing hypotheses regarding relationships between muscle cell biochemistry and whole-body physiology with unusually high statistical power. We hypothesized that i) whole-body VO2max would correlate with muscle respiratory capacity, ii) resting muscle phosphocreatine concentration ([PCr]) would negatively correlate with delta efficiency and iii) muscle mitochondrial function would positively correlate with both resting VO2 and total daily energy expenditure (TDEE). Muscle respiratory capacity explained a quarter of the variation in VO2max (r2 = 26, p < .001, n = 87). There was an inverse correlation between muscle [PCr] and delta efficiency (r = −23, p = 046, n = 87). There was also a correlation between [PCr] recovery halftime and TDEE (r = −23, p = 035, n = 87). Our data not only provide insights into muscle cell chemistry and whole-body physiology but our mixed cohort means that our findings are broadly generalizable. PMID:23378914

  20. Synthesis, structure, and /sup 31/P and /sup 183/W NMR spectra of P/sub 4/W/sub 14/O/sub 58//sup 12/minus//

    SciTech Connect

    Thouvenot, R.; Teze, A.; Contant, R.; Herve, G.

    1988-02-10

    The P/sub 4/W/sub 14/O/sub 58//sup 12/minus// anion was obtained from the reaction of sodium tungstate and sodium phosphate in acetic acid. The structure of K/sub 12/P/sub 4/W/sub 14/O/sub 58/ /times/ 21H/sub 2/O (monoclinic, C2/c; a = 22.145 (6) /angstrom/, b = 15.823 (2) /angstrom/, c = 21.860 (4) /angstrom/, /beta/ = 109.54 (2)/degree/; Z = 4) has been refined to final indices R and R/sub w/ of 0.048 and 0.055. The polyanion consists on two PW/sub 7/O/sub 29/ subunits linked by two phosphorus atoms. This dimeric structure is preserved in aqueous solution as shown by /sup 183/W and /sup 31/P NMR spectra. Unusual spin-spin coupling constants, i.e. /sup 2/J/sub W-P/ = 18, 10.2 Hz and /sup 2/J/sub W-W/ = 37 Hz, as well as a four-bond coupling (/sup 4/j/sub W-P/ of about 2 Hz) are discussed in relation to the structural parameters. Some characteristic features of the vibrational (IR and Raman) spectra are also discussed. 20 refs., 6 figs., 4 tabs.

  1. Synthesis, crystal structure, vibrational and 31P-NMR spectroscopy of the thiophosphate NaMg[PO3S]·9H2O

    NASA Astrophysics Data System (ADS)

    Höppe, Henning A.; Scharinger, Stefan W.; Heck, Joachim G.; Gross, Peter; Netzsch, Philip; Kazmierczak, Karolina

    2016-12-01

    NaMg[PO3S]·9H2O was obtained as single-phase crystalline powder starting from NaOH, PSCl3 and MgCl2·6H2O. At room temperature NaMg[PO3S]·9H2O crystallises in space group Cmc21 (no. 36) (a=638.58(4) pm, b=1632.31(10) pm, c=1217.16(7) pm, Z = 4; Rint = 0.032, Rσ = 0.034, R1 = 0.036, wR2 = 0.071). The data collection at 100 K reveals an ordering of the PO3S tetrahedra by undergoing a symmetry reduction to P21 (no. 4) and an according formation of twins (C1121, unconv. setting of P21, a=631.41(3) pm, b=1630.00(7) pm, c=1219.24(5) pm, γ=90.00(2)°, Z = 4; Rint = 0.115, Rσ = 0.064, R1 = 0.045, wR2 = 0.070). NaMg[PO3S]·9H2O comprises isolated PO3S tetrahedra, distorted MgO6 octahedra and trigonal NaO6 prisms. 31P NMR spectroscopy showed a chemical shift of 33.7 ppm. The vibrational spectra of NaMg[PO3S]·9H2O were recorded and the relevant bands were assigned.

  2. In vivo (31)P magnetic resonance spectroscopy and morphometric analysis of the perfused vascular architecture of human glioma xenografts in nude mice.

    PubMed Central

    van der Sanden, B. P.; Rijken, P. F.; Heerschap, A.; Bernsen, H. J.; van der Kogel, A. J.

    1997-01-01

    The relationship between the bioenergetic status of human glioma xenografts in nude mice and morphometric parameters of the perfused vascular architecture was studied using (31)P magnetic resonance spectroscopy (MRS), fluorescence microscopy and two-dimensional digital image analysis. Two tumour lines with a different vascular architecture were used for this study. Intervascular distances and non-perfused area fractions varied greatly between tumours of the same line and tumours of different lines. The inorganic phosphate-nucleoside triphosphate (P(i)/NTP) ratio increased rapidly as mean intervascular distances increased from 100 microm to 300 microm. Two morphometric parameters - the percentage of intervascular distances larger than 200 microm (ivd200) and the non-perfused area fraction at a distance larger than 100 microm from a nearest perfused vessel (area100), - were deduced from these experiments and related to the P(i)/NTP ratio of the whole tumour. It is assumed that an aerobic to anaerobic transition influences the bioenergetic status, i.e. the P(i)/NTP ratio increased linearly with the percentage of ivd200 and the area100. PMID:9166934

  3. Phospholipid compositions of sera and synovial fluids from dog, human and horse: a comparison by 31P-NMR and MALDI-TOF MS.

    PubMed

    Fuchs, B; Bondzio, A; Wagner, U; Schiller, J

    2009-08-01

    Alterations of the phospholipid (PL) compositions of body fluids are assumed to be indicative of inflammatory diseases, e.g. rheumatoid arthritis (RA). Recently, we have shown that particularly the phosphatidylcholine/lysophosphatidylcholine (PC/LPC) ratio determined in human synovial fluids (SF) and sera represents a reliable measure of the inflammatory state in RA patients. However, it is not yet clear to what extent the PC/LPC ratio is also affected by nutrition habits. In the present study, the PL and the corresponding acyl chain compositions of human body fluids (SF and serum of RA patients as well as serum from healthy volunteers) are compared with those of two other mammalian species (horses and dogs suffering from degenerative joint diseases as well as healthy controls) by high-resolution 31P-nuclear magnetic resonance (NMR) spectroscopy and matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS). The most important result of this study is that the PL compositions of SF and serum of horse and dog are comparable with those of human body fluids. Compared with humans, however, the horse body fluid contains less PCs with highly unsaturated arachidonoyl residues, while that of dogs possesses the highest content of arachidonoyl-containing PC. These species-related differences stem primarily from different nutrition habits (meat vs. plants).

  4. Relationship between Superconductivity and Antiferromagnetism in LaFe(As1-xPx)O Revealed by 31P-NMR

    NASA Astrophysics Data System (ADS)

    Kitagawa, Shunsaku; Iye, Tetsuya; Nakai, Yusuke; Ishida, Kenji; Wang, Cao; Cao, Guang-Han; Xu, Zhu-An

    2014-02-01

    We performed 31P-NMR measurements on LaFe(As1-xPx)O to investigate the relationship between antiferromagnetism and superconductivity. The antiferromagnetic (AFM) ordering temperature TN and the moment µord are continuously suppressed with increasing P content x and disappear at x = 0.3 where bulk superconductivity appears. At this superconducting x = 0.3, quantum critical AFM fluctuations are observed, indicative of the intimate relationship between superconductivity and low-energy AFM fluctuations associated with the quantum-critical point in LaFe(As1-xPx)O. The relationship is similar to those observed in other isovalent-substitution systems, e.g., BaFe2(As1-xPx)2 and SrFe2(As1-xPx)2, with the "122" structure. Moreover, the AFM order reappears with further P substitution (x > 0.4). The variation of the ground state with respect to the P substitution is considered to be linked to the change in the band character of Fe-3d orbitals around the Fermi level.

  5. The investigation of membrane binding by amphibian peptide agonists of CCK2R using (31)P and (2)H solid-state NMR.

    PubMed

    Sherman, Patrick J; Separovic, Frances; Bowie, John H

    2014-05-01

    It has been proposed that some neuropeptides may be anchored to the cell membranes prior to attaching to the adjacent active sites of transmembrane receptors. The three amphibian skin neuropeptides signiferin 1 [RLCIPYIIPC(OH)] (smooth muscle active and immunomodulator), riparin 1.1 [[RLCIPVIFPC(OH)] (immunomodulator) and rothein 1 [SVSNIPESIGF(OH)] (immunomodulator) act via CCK2 transmembrane receptors. A combination of (31)P and (2)H solid state NMR studies of each of these three peptides in eukaryotic phospholipid models at 25°C shows that rothein 1 does not interact with the membrane at all. In contrast, both of the cyclic disulfides signiferin 1 and riparin 1.1 interact with phospholipid head groups and partially penetrate into the upper leaflet of the model bilayer, but to different extents. These interactions are not sufficiently effective to cause disruption of the lipid bilayer since the peptides are not antimicrobial, anticancer, antifungal nor active against enveloped viruses. Copyright © 2014. Published by Elsevier Inc.

  6. The effect of ethanol on hydroxyl and carbonyl groups in biopolyol produced by hydrothermal liquefaction of loblolly pine: (31)P-NMR and (19)F-NMR analysis.

    PubMed

    Celikbag, Yusuf; Via, Brian K; Adhikari, Sushil; Buschle-Diller, Gisela; Auad, Maria L

    2016-08-01

    The goal of this study was to investigate the role of ethanol and temperature on the hydroxyl and carbonyl groups in biopolyol produced from hydrothermal liquefaction of loblolly pine (Pinus spp.) carried out at 250, 300, 350 and 390°C for 30min. Water and water/ethanol mixture (1/1, wt/wt) were used as liquefying solvent in the HTL experiments. HTL in water and water/ethanol is donated as W-HTL and W/E-HTL, respectively. It was found that 300°C and water/ethanol solvent was the optimum liquefaction temperature and solvent, yielding up to 68.1wt.% bio-oil and 2.4wt.% solid residue. (31)P-NMR analysis showed that biopolyol produced by W-HTL was rich in phenolic OH while W/E-HTL produced more aliphatic OH rich biopolyols. Moreover, biopolyols with higher hydroxyl concentration were produced by W/E-HTL. Carbonyl groups were analyzed by (19)F-NMR, which showed that ethanol reduced the concentration of carbonyl groups. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Intermolecular protein-RNA interactions revealed by 2D 31P-15N magic angle spinning solid-state NMR spectroscopy.

    PubMed

    Jehle, Stefan; Falb, Melanie; Kirkpatrick, John P; Oschkinat, Hartmut; van Rossum, Barth-Jan; Althoff, Gerhard; Carlomagno, Teresa

    2010-03-24

    The structural investigation of large RNP complexes by X-ray crystallography can be a difficult task due to the flexibility of the RNA and of the protein-RNA interfaces, which may hinder crystallization. In these cases, NMR spectroscopy is an attractive alternative to crystallography, although the large size of typical RNP complexes may limit the applicability of solution NMR. Solid-state NMR spectroscopy, however, is not subject to any intrinsic limitations with respect to the size of the object under investigation, with restrictions imposed solely by the sensitivity of the instrumentation. In addition, it does not require large, well-ordered crystals and can therefore be applied to flexible, partially disordered complexes. Here we show for the first time that solid-state NMR spectroscopy can be used to probe intermolecular interactions at the protein-RNA interface in RNP complexes. Distances between the (15)N nuclei of the protein backbone and the (31)P nuclei of the RNA backbone can be measured in TEDOR experiments and used as restraints in structure calculations. The distance measurement is accurate, as proven for the test case of the L7Ae-box C/D RNA complex, for which a crystal structure is available. The results presented here reveal the as yet unexplored potential of solid-state NMR spectroscopy in the investigation of large RNP complexes.

  8. In vivo evidence of abnormal mechanical and oxidative functions in the exercised muscle of dystrophic hamsters by 31P-NMR.

    PubMed

    Le Rumeur, E; Le Tallec, N; Lewa, C J; Ravalec, X; de Certaines, J D

    1995-11-01

    Mechanical properties and metabolic adaptation to exercise in skeletal muscle of dystrophic hamsters were studied with an in vivo 31P-NMR multistep fatigue test. Three successive 20-min steps with increasing rhythms of tetanic stimulation were followed by a 20-min recovery period. Fatigue in dystrophic hamsters (DH) developed more rapidly and was greater than in normal hamsters (NH); total mechanical performance per min increased step by step in NH while it decreased in DH, showing a progressive mechanical impairment of the dystrophic muscles. ADP and PCr recovery rates were significantly reduced in DH muscles. Acidosis appeared in both DH and NH and persisted in DH throughout the test, suggesting reduced mitochondrial oxidative capacity of the dystrophic muscle. The pH recovery rate was reduced in DH muscles suggesting a reduction in export protons capacity. These results provide evidence of impaired mitochondrial function and intracellular ionic regulation in the dystrophic muscle, associated with the lack of dystrophin and dystrophin-associated glycoproteins in the DH.

  9. High Resolution NMR ^15N and ^31P NMR Of Antiferroelectric Phase Transition in Ammonium Dihydrogen Arsenate and Ammonium Dihydrogen Phosphate

    NASA Astrophysics Data System (ADS)

    Gunaydin-Sen, Ozge

    2005-03-01

    Natural abundance ^15N CPMAS NMR has been used to investigate the paraelectric-antiferroelectric phase transition of NH4H2AsO4 (ADA) (TN˜216K) and of NH4H2PO4 (ADP) (148K), with a focus on the role of the NH4^+ ion. Isotropic chemical shift of ^15N for ADA exhibits an almost linear temperature dependence to within TN±1K, and then changes discontinuously, followed by another almost linear dependence. The spectra of the paraelectric and antiferroelectric phases coexist around the TN. The sharp anomaly around TN implies that the NH4^+ ions undergo a displacive transition, whereas the protons in the O-HO bonds undergo an order-disorder transition. The ^15N data thus support a mixed order-disorder-displacive mechanism for this transition. The ^15N data on ADP exhibit somewhat different behavior. ^31P CPMAS measurements will also be presented and discussed in terms of the above model.

  10. Interaction of Alamethicin with Ether-Linked Phospholipid Bilayers: Oriented Circular Dichroism, 31P Solid-State NMR, and Differential Scanning Calorimetry Studies

    PubMed Central

    Dave, Paresh C.; Billington, Emma; Pan, Yeang-Ling; Straus, Suzana K.

    2005-01-01

    The arrangement of the antimicrobial peptide alamethicin was studied by oriented circular dichroism, 31P solid-state NMR, and differential scanning calorimetry in ether-linked phospholipid bilayers composed of 1,2-O-dihexadecyl-sn-glycero-3-phosphocholine (DHPC). The measurements were performed as a function of alamethicin concentration relative to the lipid concentration, and results were compared to those reported in the literature for ester-linked phospholipid bilayers. At ambient temperature, alamethicin incorporates into the hydrophobic core of DHPC bilayers but results in more lipid disorder than observed for ester-linked 1-palmitoyl, 2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) lipid bilayers. This orientational disorder appears to depend on lipid properties such as bilayer thickness. Moreover, the results suggest that alamethicin inserts into the hydrophobic core of the bilayers (at high peptide concentration) for both ether- and ester-linked lipids but using a different mechanism, namely toroidal for DHPC and barrel-stave for POPC. PMID:16055546

  11. Variations of different dissolved and particulate phosphorus classes during an algae bloom in a eutrophic lake by (31)P NMR spectroscopy.

    PubMed

    Bai, Xiuling; Sun, Jinhua; Zhou, Yunkai; Gu, Lei; Zhao, Hongyan; Wang, Jiehua

    2017-02-01

    Characterization of phosphorus (P) pools is vital to understanding the contribution of P to water eutrophication. In this study, dissolved and particulate P classes during an algae bloom in Lake Taihu, as well as their relationships with the main environmental factors, were analyzed based on solution (31)P NMR. The results showed that dissolved P was dominated by orthophosphate (Ortho-P) in heavily polluted regions and by orthophosphate monoester (Mono-P) and orthophosphate diester (Diester-P) in lightly polluted regions, indicating that the main dissolved P classes varied with the degree of lake pollution. The difference in the temporal variation patterns of dissolved P classes revealed that dissolved Ortho-P is the preferred class, and its concentration may be affected by major primary producers. It also revealed that dissolved Mono-P is prone to accumulation under the effects of algal blooms, especially in heavily polluted regions. The main particulate P classes were similar to those of dissolved P, but their variation trends were the same in different lake regions. There were significant positive correlations between the major particulate P classes and Chl a during the majority of the sampling period, indicating that living algal cells have a major contribution to particulate P. Obvious temporal variations of P classes may affect the bioavailability and dynamics of P in the water of Lake Taihu, but the particle reactivities of the main inorganic and organic P classes were similar. Therefore, they have little effect on P partitioning between the dissolved and particulate phases.

  12. Rate equation for creatine kinase predicts the in vivo reaction velocity: /sup 31/P NMR surface coil studies in brain, heart, and skeletal muscle of the living rat

    SciTech Connect

    Bittl, J.A.; DeLayre, J.; Ingwall, J.S.

    1987-09-22

    Brain, heart, and skeletal muscle contain four different creatine kinase isozymes and various concentrations of substrates for the creatine kinase reaction. To identify if the velocity of the creatine kinase reaction under cellular conditions is regulated by enzyme activity and substrate concentrations as predicted by the rate equation, the authors used /sup 31/P NMR and spectrophotometric techniques to measure reaction velocity, enzyme content, isozyme distribution, and concentrations of substrates in brain, heart, and skeletal muscle of living rat under basal or resting conditions. The total tissue activity of creatine kinase in the direction of MgATP synthesis provided an estimate for V/sub max/ and exceeded the NMR-determined in vivo reaction velocities by an order of magnitude. The isozyme composition varied among the three tissues: >99% BB for brain; 14% MB, 61% MM, and 25% mitochondrial for heart; and 98% MM and 2% mitochondrial for skeletal muscle. The NMR-determined reaction velocities agreed with predicted values from the creatine kinase rate equation. The concentrations of free creatine and cytosolic MgADP, being less than or equal to the dissociation constants for each isozyme, were dominant terms in the creatine kinase rate equation for predicting the in vivo reaction velocity. Thus, they observed that the velocity of the creatine kinase reaction is regulated by total tissue enzyme activity and by the concentrations of creatine and MgADP in a manner that is independent of isozyme distribution.

  13. Cooperation and Competition between Adenylate Kinase, Nucleoside Diphosphokinase, Electron Transport, and ATP Synthase in Plant Mitochondria Studied by 31P-Nuclear Magnetic Resonance.

    PubMed Central

    Roberts, JKM.; Aubert, S.; Gout, E.; Bligny, R.; Douce, R.

    1997-01-01

    Nucleotide metabolism in potato (Solanum tuberosum) mitochondria was studied using 31P-nuclear magnetic resonance spectroscopy and the O2 electrode. Immediately following the addition of ADP, ATP synthesis exceeded the rate of oxidative phosphorylation, fueled by succinate oxidation, due to mitochondrial adenylate kinase (AK) activity two to four times the maximum activity of ATP synthase. Only when the AK reaction approached equilibrium was oxidative phosphorylation the primary mechanism for net ATP synthesis. A pool of sequestered ATP in mitochondria enabled AK and ATP synthase to convert AMP to ATP in the presence of exogenous inorganic phosphate. During this conversion, AK activity can indirectly influence rates of oxidation of both succinate and NADH via changes in mitochondrial ATP. Mitochondrial nucleoside diphosphokinase, in cooperation with ATP synthase, was found to facilitate phosphorylation of nucleoside diphosphates other than ADP at rates similar to the maximum rate of oxidative phosphorylation. These results demonstrate that plant mitochondria contain all of the machinery necessary to rapidly regenerate nucleoside triphosphates from AMP and nucleoside diphosphates made during cellular biosynthesis and that AK activity can affect both the amount of ADP available to ATP synthase and the level of ATP regulating electron transport. PMID:12223600

  14. Facilitated transport of Mn2+ in sycamore (Acer pseudoplatanus) cells and excised maize root tips. A comparative 31P n.m.r. study in vivo.

    PubMed Central

    Roby, C; Bligny, R; Douce, R; Tu, S I; Pfeffer, P E

    1988-01-01

    Movement of paramagnetic Mn2+ into sycamore (Acer pseudoplatanus) cells has been indirectly examined by observing the line broadening exhibited in its 31P n.m.r. spectra. Mn2+ was observed to pass into the vacuole, while exhibiting a very minor accumulation in the cytoplasm. With time, gradual leakage of phosphate from the vacuole to the cytoplasm was observed along with an increase in glucose-6-phosphate. Anoxia did not appear to affect the relative distribution of Mn2+ in the cytoplasm and vacuole. Under hypoxic conditions restriction of almost all movement of Mn2+ across the plasmalemma as well as the tonoplast was observed. In contrast, maize root tips showed entry and complete complexation of nucleotide triphosphate by Mn2+ during hypoxia. The rate of passage of Mn2+ across the tonoplast in both sycamore and maize root cells is approximately the same. However, the rates of facilitated movement across the respective plasma membranes appear to differ. More rapid movement of Mn2+ across the plasmalemma in maize root tip cells allows a gradual build-up of metal ion in the cytoplasm prior to its diffusion across the tonoplast. Sycamore cells undergo a slower uptake of Mn2+ into their cytoplasms (comparable with the rate of diffusion through the tonoplast), so little or no observable accumulation of Mn2+ is observed in this compartment. PMID:3415663

  15. In vivo sup 23 Na and sup 31 P NMR measurement of a tonoplast Na sup + /H sup + exchange process and its characteristics in two barley cultivars

    SciTech Connect

    Fan, T.W.M.; Norlyn, J.; Epstein, E. ); Higashi, R.M. )

    1989-12-01

    A Na{sup +} uptake-associated vacuolar alkalinization was observed in roots of two barley cultivars (Arivat and the more salt-tolerant California Mariout) by using {sup 23}Na and {sup 31}P in vivo NMR spectroscopy. A NaCl uptake-associated broadening was also noted for both vacuolar P{sub i} and intracellular Na NMR peaks, consistent with Na{sup +} uptake into the same compartment as the vacuolar P{sub i}. A close coupling of Na{sup +} with H{sup +} transport (presumably the Na{sup +}/H{sup +} antiport) in vivo was evidence by qualitative and quantitative correlations between Na{sup +} accumulation and vacuolar alkalinization for both cultivars. Prolongation of the low NaCl pretreatment (30 mM) increased the activity of the putative anti