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Sample records for 31p nucleus polnaya

  1. 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.

  2. Determination of coordination modes and estimation of the 31P-31P distances in heterogeneous catalyst by solid state double quantum filtered 31P NMR spectroscopy.

    PubMed

    Zhang, Si-Yong; Wang, Mei-Tao; Liu, Qing-Hua; Hu, Bing-Wen; Chen, Qun; Li, He-Xing; Amoureux, Jean-Paul

    2011-04-01

    To overcome the separation difficulty of the palladium-based homogeneous catalyst, the palladium complex can be anchored on various supports such as silica. However, it is difficult to determine the amounts of the two coordination modes of the Pd nucleus, that is, Pd coordinates with one phosphorus atom and Pd coordinates with two phosphorus atoms. Here a (31)P double-quantum filtered (DQ-filtered) method in solid-state NMR is introduced for the palladium-based heterogenous catalyst system. With the DQ-filtered method, we can not only determine the amounts of the two different kinds of palladium coordination modes, we can also estimate the interatomic distance of two (31)P nuclei bonded to a palladium nucleus. With the help of this method, we can quickly estimate interatomic distances in our designed system and accurately re-design the palladium system to accommodate either one (31)P or two (31)P. PMID:21301702

  3. Feasibility Evaluation of Detecting Hydroxymethylphosphine Oxide In Vivo by (31)P-MRS.

    PubMed

    Doblas, Sabrina; Pathuri, Gopal; Towner, Rheal A; Gali, Hariprasad

    2010-09-01

    Application of organophosphorus compounds in biomedicine is attractive because the (31)P nucleus is very amenable to study by nuclear magnetic resonance (NMR) techniques, particularly, by in vivo (31)P magnetic resonance spectroscopy ((31)P-MRS). The water-soluble organophosphorus compounds that are non-toxic, exhibit metabolic stability, and show a unique resonance peak in (31)P NMR spectroscopy, which could be ideal to be used as probes for (31)P-MRS. Here we evaluated the in vivo feasibility of potentially using a hydroxymethylphosphine oxide as a novel probe for (31)P-MRS studies using tris (hydroxymethyl) phosphine oxide (THPO) as an example. THPO was synthesized, injected in the normal CF1 mice, and (31)P spectra were acquired before and after injection with the coil located on the regions of interest. The NMR signal from the region of interest appeared within one minute of THPO injection. The compound was stable in vivo as no metabolites of THPO were observed. No toxicity was observed after THPO injection in mice. The peak concentrations of THPO in liver and kidney were reached within 15 min and 60 min respectively. THPO was excreted exclusively in urine without undergoing any metabolism indicating that it is very stable under in vivo conditions. These initial studies in normal CF1 mice clearly demonstrate that THPO possess the essential characteristics required for a potential MRS probe. Based on the current preliminary results, we suggest that HMPs, when incorporated into targeted drugs (peptides, proteins, antibodies, etc.), may serve as novel (31)P probes for monitoring the drug distribution in vivo by MRS. PMID:23675197

  4. 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

  5. Accurate calculation of (31)P NMR chemical shifts in polyoxometalates.

    PubMed

    Pascual-Borràs, Magda; López, Xavier; Poblet, Josep M

    2015-04-14

    We search for the best density functional theory strategy for the determination of (31)P nuclear magnetic resonance (NMR) chemical shifts, δ((31)P), in polyoxometalates. Among the variables governing the quality of the quantum modelling, we tackle herein the influence of the functional and the basis set. The spin-orbit and solvent effects were routinely included. To do so we analysed the family of structures α-[P2W18-xMxO62](n-) with M = Mo(VI), V(V) or Nb(V); [P2W17O62(M'R)](n-) with M' = Sn(IV), Ge(IV) and Ru(II) and [PW12-xMxO40](n-) with M = Pd(IV), Nb(V) and Ti(IV). The main results suggest that, to date, the best procedure for the accurate calculation of δ((31)P) in polyoxometalates is the combination of TZP/PBE//TZ2P/OPBE (for NMR//optimization step). The hybrid functionals (PBE0, B3LYP) tested herein were applied to the NMR step, besides being more CPU-consuming, do not outperform pure GGA functionals. Although previous studies on (183)W NMR suggested that the use of very large basis sets like QZ4P were needed for geometry optimization, the present results indicate that TZ2P suffices if the functional is optimal. Moreover, scaling corrections were applied to the results providing low mean absolute errors below 1 ppm for δ((31)P), which is a step forward in order to confirm or predict chemical shifts in polyoxometalates. Finally, via a simplified molecular model, we establish how the small variations in δ((31)P) arise from energy changes in the occupied and virtual orbitals of the PO4 group. PMID:25738630

  6. 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%.

  7. 4 T Actively detuneable double-tuned 1H/31P head volume coil and four-channel 31P phased array for human brain spectroscopy.

    PubMed

    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. PMID:17379554

  8. 13C and 31P chemical shielding tensors of a single crystal of dipotassium α- D-glucose-1-phosphate dihydrate. An application of a 13C-{ 1H, 31P} triple-resonance technique

    NASA Astrophysics Data System (ADS)

    McDowell, C. A.; Naito, A.; Sastry, D. L.; Takegoshi, K.

    The 13C NMR spectra of a single crystal of dipotassium α- D-glucose-l-phosphate dehydrate for different orientations in the external magnetic field, were recorded by using 1H and 31P double nuclear decoupling. To overcome difficulties encountered because of the high 13C RF power required to achieve the Hartmann-Hahn condition, a new cross-polarization method (K. Takegoshi and C. A. McDowell, J. Magn. Reson.67, 356 (1986)) was used. The directions of the most shielded principal value of the 13C chemical shielding tensors for the C2-C6 carbon nuclei in the glucose group were along the CO bond, and that for the CI carbon nucleus made an angle of 42† with the C1-O5 bond direction in the O1-C1-O5 plane. The 31P chemical shielding tensors are axially symmetric and the direction of the least shielded principal value is almost parallel to the P-O1(R) bond, which is the longest among the four PO bonds in the phosphate moiety.

  9. 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.

  10. 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

  11. 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

  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. 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.

  14. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. Solid State FT-IR and (31)P NMR Spectral Features of Phosphate Compounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Solid-state spectroscopic techniques, including Fourier transform infrared (FT-IR) and solid-state 31P magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopies, are powerful tools for evaluating metal speciation and transformation mechanisms of P compounds in the environment. Studie...

  17. Structure and motion of phospholipids in human plasma lipoproteins. A sup 31 P NMR study

    SciTech Connect

    Fenske, D.B.; Chana, R.S.; Parmar, Y.I.; Treleaven, W.D.; Cushley, R.J. )

    1990-04-24

    The structure and motion of phospholipids in human plasma lipoproteins have been studied by using {sup 31}P NMR. Lateral diffusion coefficients, D{sub T}, obtained from the viscosity dependence of the {sup 31}P NMR line widths, were obtained for very low density lipoprotein (VLDL), low-density lipoprotein (LDL), high-density lipoproteins (HDL{sub 2}, HDL{sub 3}), and egg PC/TO microemulsions at 25{degree}C, for VLDL at 40{degree}C, and for LDL at 45{degree}C. In order to prove the orientation and/or order of the phospholipid head-group, estimates of the residual chemical shift anistropy, {Delta}{sigma}, have been obtained for all the lipoproteins and the microemulsions from the viscosity and field dependence for the {sup 31}P NMR line widths. These results suggest differences in the orientation and/or ordering of the head-group in the HDLs. The dynamic behavior of the phosphate moiety in LDL and HDL{sub 3} has been obtained from the temperature dependence of the {sup 31}P spin-lattice relaxation rates. Values of the correlation time for phosphate group reorientation and the activation energy for the motion are nearly identical in LDL and HDL{sub 3} and are similar to values obtained for phospholipid bilayers. This argues against long-lived protein-lipid interactions being the source of either the slow diffusion in LDL or the altered head-group orientation in the HDLs.

  18. Functional group analysis in coal by sup 31 P NMR spectroscopy

    SciTech Connect

    Verkade, J.G.

    1989-05-01

    The purpose of this research is to determine the labile-hydrogen functional group composition of coal and coal-derived materials by the nmr spectroscopy of their derivatives made with reagents containing the nmr-active nuclei {sup 31}P, {sup 119}Sn, or {sup 205}Tl. 7 refs.

  19. Accuracy and precision of quantitative 31P-MRS measurements of human skeletal muscle mitochondrial function.

    PubMed

    Layec, Gwenael; Gifford, Jayson R; Trinity, Joel D; Hart, Corey R; Garten, Ryan S; Park, Song Y; Le Fur, Yann; Jeong, Eun-Kee; Richardson, Russell S

    2016-08-01

    Although theoretically sound, the accuracy and precision of (31)P-magnetic resonance spectroscopy ((31)P-MRS) approaches to quantitatively estimate mitochondrial capacity are not well documented. Therefore, employing four differing models of respiratory control [linear, kinetic, and multipoint adenosine diphosphate (ADP) and phosphorylation potential], this study sought to determine the accuracy and precision of (31)P-MRS assessments of peak mitochondrial adenosine-triphosphate (ATP) synthesis rate utilizing directly measured peak respiration (State 3) in permeabilized skeletal muscle fibers. In 23 subjects of different fitness levels, (31)P-MRS during a 24-s maximal isometric knee extension and high-resolution respirometry in muscle fibers from the vastus lateralis was performed. Although significantly correlated with State 3 respiration (r = 0.72), both the linear (45 ± 13 mM/min) and phosphorylation potential (47 ± 16 mM/min) models grossly overestimated the calculated in vitro peak ATP synthesis rate (P < 0.05). Of the ADP models, the kinetic model was well correlated with State 3 respiration (r = 0.72, P < 0.05), but moderately overestimated ATP synthesis rate (P < 0.05), while the multipoint model, although being somewhat less well correlated with State 3 respiration (r = 0.55, P < 0.05), most accurately reflected peak ATP synthesis rate. Of note, the PCr recovery time constant (τ), a qualitative index of mitochondrial capacity, exhibited the strongest correlation with State 3 respiration (r = 0.80, P < 0.05). Therefore, this study reveals that each of the (31)P-MRS data analyses, including PCr τ, exhibit precision in terms of mitochondrial capacity. As only the multipoint ADP model did not overstimate the peak skeletal muscle mitochondrial ATP synthesis, the multipoint ADP model is the only quantitative approach to exhibit both accuracy and precision. PMID:27302751

  20. Surface coil localization of /sup 31/P NMR signals from orthotopic human kidney and liver

    SciTech Connect

    Jue, T.; Rothman, D.L.; Lohman, J.A.B.; Hughes, E.W.; Hanstock, C.C.; Shulman, R.G.

    1988-02-01

    By incorporating the hyperbolic secant inversion pulses with the image-selected in vivo spectroscopy localization technique and by applying a gradient-echo imaging method, the authors have selected only the /sup 31/P NMR signals from orthotopic human kidney and liver, using a single concentric /sup 1/H//sup 31/P surface coil. Corresponding to the experimental results on animal studies, the phosphocreatine signal is dramatically reduced in the localized spectra. The localization strategy also allows them to shim easily on the well-defined volume of interest and leads to high-resolution spectra that exhibit multiplet structure. The results indicate that they can obtain localized signals from deep small organs and point the way for other human metabolism studies.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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. PMID:27343937

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 ...

  8. In vivo 31P-NMR spectroscopy of right ventricle in pigs.

    PubMed

    Schwartz, G G; Steinman, S K; Weiner, M W; Matson, G B

    1992-06-01

    The energy metabolism of the right ventricle (RV) in vivo has been largely unexplored. The goal of this study was to develop and implement techniques for in vivo 31P nuclear magnetic resonance (NMR) spectroscopy of the RV free wall. A two-turn, crossover-design elliptical surface coil was constructed to provide high sensitivity across the thin RV wall but minimal sensitivity in the blood-filled RV cavity. In 36 open-chest, anesthetized pigs, 31P spectroscopy of the RV free wall was performed with this coil at a field strength of 2 Tesla. Spectra were obtained from 800 acquisitions in 24 min with an average signal-to-noise ratio of 13.2 for phosphocreatine (PCr). The PCr-to-ATP (PCr/ATP) ratio of porcine RV was 1.42 +/- 0.05 (mean +/- SE), uncorrected for saturation at a repetition time of 1.8 s. With the use of literature values of the time constant of longitudinal relaxation (T1) to correct for partial saturation, the RV PCr/ATP was estimated to lie between 1.7 and 2.3. Decreased RV PCr/ATP was observed during RV ischemia and pressure overload. Thus in vivo 31P spectroscopy of the RV is readily accomplished with an appropriate surface coil and can provide new information about RV energy metabolism. PMID:1621852

  9. [sup 31]P NMR study of immobilized artificial membrane surfaces. Structure and dynamics of immobilized phospholipids

    SciTech Connect

    Qiu, X.; Pidgeon, C. )

    1993-11-25

    Chromatography surfaces were prepared by immobilizing a single-chain ether phospholipid at approximately a monolayer density on silica particles. The chromatography particles are denoted as [sup ether]IAM.PC[sup C10/C3], and they are stable to all solvents. The structure and dynamics of the interphase created by immobilizing phospholipids on silica particles were studied by [sup 31]P NMR methods. [sup ether]IAM.PC[sup C10/C3] spontaneously wets when suspended in both aqueous and organic solvents, and [sup 31]P NMR spectra were obtained in water, methanol, chloroform, acetonitrile, and acetone. [sup 31]P NMR spectra were subjected to line-shape analysis. From line-shape analysis, the correlation times for rapid internal motion ([tau]-PLL) and wobbling ([tau]-PRP) of the phospholipid headgroup were calculated for each solvent. Immobilized phospholipid headgroups comprising the IAM interfacial region undergo rapid reorientation similar to the case of the phospholipids forming liposome membranes with [tau]-PLL approximately 1 ns. Phospholipids in liposome membranes exhibit slower wobbling motion ([tau]-PRP approximately 1 ms) in the plane of the membrane. However, the immobilized phospholipids on [sup ether]IAM.PC[sup C10/C3] surfaces wobble with correlation times [tau]-PRP that depend on the solvent bathing the [sup ether]IAM.PC[sup C10/C3] surface. 41 refs., 9 figs., 2 tabs.

  10. 31P MAS-NMR of human erythrocytes: independence of cell volume from angular velocity.

    PubMed

    Kuchel, P W; Bubb, W A; Ramadan, S; Chapman, B E; Philp, D J; Coen, M; Gready, J E; Harvey, P J; McLean, A J; Hook, J

    2004-09-01

    31P magic angle spinning NMR (MAS-NMR) spectra were obtained from suspensions of human red blood cells (RBCs) that contained the cell-volume-sensitive probe molecule, dimethyl methylphosphonate (DMMP). A mathematical representation of the spectral-peak shape, including the separation and width-at-half-height in the 31P NMR spectra, as a function of rotor speed, enabled us to explore the extent to which a change in cell volume would be reflected in the spectra if it occurred. We concluded that a fractional volume change in excess of 3% would have been detected by our experiments. Thus, the experiments indicated that the mean cell volume did not change by this amount even at the highest spinning rate of 7 kHz. The mean cell volume and intracellular 31P line-width were independent of the packing density of the cells and of the initial cell volume. The relationship of these conclusions to other non-NMR studies of pressure effects on cells is noted. PMID:15334588

  11. /sup 31/P nuclear magnetic resonance measurements of intracellular pH in giant barnacle muscle

    SciTech Connect

    Hamm, J.R.; Yue, G.M.

    1987-01-01

    The accuracy of intracellular pH (pH/sub i/) measurements by /sup 31/P nuclear magnetic resonance (NMR) spectroscopy was examined in single muscle fibers from the giant barnacle, Balanus nubilis. The pH/sub i/ was derived from the chemical shifts of 2-deoxy-D-glucose-6-phosphate and inorganic phosphate. In fibers superfused with sea water at pH 7.7, pH/sub i/ = 7.30 +/- 0.02 at 20/sup 0/C. Experimentally induced pH/sub i/ changes were followed with a time resolution of 3 min. Intracellular alkalinization was induced by exposure to NH/sub 3/Cl and intracellular acidification followed when NH/sub 3/ was removed. Then acid extrusion was stimulated by exposure to bicarbonate containing sea water. In single muscle fibers /sup 31/P NMR results were in excellent agreement with microelectrode studies over the pH range of 6.5 to 8.0. The initial acid extrusion rate was 1.7 +/- 0.3 mmol x 1/sup -1/ x min/sup -1/ at pH/sub i/ 6.75. The authors results showed that /sup 31/P NMR is a reliable in vivo pH probe.

  12. 31P nuclear magnetic resonance measurements of intracellular pH in giant barnacle muscle.

    PubMed

    Hamm, J R; Yue, G M

    1987-01-01

    The accuracy of intracellular pH (pHi) measurements by 31P nuclear magnetic resonance (NMR) spectroscopy was examined in single muscle fibers from the giant barnacle, Balanus nubilis. The pHi was derived from the chemical shifts of 2-deoxy-D-glucose-6-phosphate and inorganic phosphate. In fibers superfused with sea water at pH 7.7, pHi = 7.30 +/- 0.02 at 20 degrees C. Experimentally induced pHi changes were followed with a time resolution of 3 min. Intracellular alkalinization was induced by exposure to NH4Cl and intracellular acidification followed when NH3 was removed. Then acid extrusion was stimulated by exposure to bicarbonate containing sea water. In single muscle fibers 31P NMR results were in excellent agreement with microelectrode studies over the pH range of 6.5 to 8.0. The initial acid extrusion rate was 1.7 +/- 0.3 mmol X l-1 X min-1 at pHi 6.75. Our results showed that 31P NMR is a reliable in vivo pH probe. PMID:3812665

  13. Compatibility of Superparamagnetic Iron Oxide Nanoparticle Labeling for 1H MRI Cell Tracking with 31P MRS for Bioenergetic Measurements

    PubMed Central

    Zhang, Zhuoli; Hancock, Brynne; Leen, Stephanie; Ramaswamy, Sharan; Sollott, Steven J.; Boheler, Kenneth R.; Juhaszova, Magdalena; Lakatta, Edward G.; Spencer, Richard G.; Fishbein, Kenneth W.

    2011-01-01

    Labeling of cells with superparamagnetic iron oxide nanoparticles permits cell tracking by 1H MRI while 31P MRS allows non-invasive evaluation of cellular bioenergetics. We evaluated the compatibility of these two techniques by obtaining 31P NMR spectra of iron-labeled and unlabeled immobilized C2C12 myoblast cells in vitro. Broadened but usable 31P spectra were obtained, and peak area ratios of resonances corresponding to intracellular metabolites showed no significant differences between labeled and unlabeled cell populations. We conclude that 31P NMR spectra can be obtained from cells labeled with sufficient iron to permit visualization by 1H imaging protocols and that these spectra have sufficient quality to be used in assessing metabolic status. This result introduces the possibility of using localized 31P MRS to evaluate the viability of iron-labeled therapeutic cells as well as surrounding host tissue in vivo. PMID:20853523

  14. 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). PMID:26492089

  15. 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

  16. 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

  17. Prediction of 31P nuclear magnetic resonance chemical shifts for phosphines

    NASA Astrophysics Data System (ADS)

    Tong, Jianbo; Liu, Shuling; Zhang, Shengwan; Li, Shengshi Z.

    2007-07-01

    Quantitative relationships of the 31P NMR chemical shifts of the phosphorus atoms in 291 phosphines with the atomic ionicity index (INI) and stereoscopic effect parameters ( ɛα, ɛβ, ɛγ) were primarily investigated in this paper for modeling some fundamental quantitative structure-spectroscopy relationships (QSSR). The results indicated that the 31P NMR chemical shifts of phosphines can be described as the quantitative equation by multiple linear regression (MLR): δp (ppm) = -174.0197 - 2.6724 INI + 40.4755 ɛα + 15.1141 ɛβ - 3.1858 ɛγ, correlation coefficient R = 0.9479, root mean square error (rms) = 13.9, and cross-validated predictive correlation coefficient was found by using the leave-one-out procedure to be Q2 = 0.8919. Furthermore, through way of random sampling, the estimative stability and the predictive power of the proposed MLR model were examined by constructing data set randomly into both the internal training set and external test set of 261 and 30 compounds, respectively, and then the chemical shifts were estimated and predicted with the training correlation coefficient R = 0.9467 and rms = 13.4 and the external predicting correlation coefficient Qext = 0.9598 and rms = 10.8. A partial least square model was developed that produced R = 0.9466, Q = 0.9407 and Qext = 0.9599, respectively. Those good results provided a new, simple, accurate and efficient methodology for calculating 31P NMR chemical shifts of phosphines.

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

    SciTech Connect

    Verkade, J.G.

    1991-01-01

    The purpose of this research is to develop a convenient, reliable and rapid NMR method for the determination of labile-hydrogen functional groups and organic sulfur compounds which are components of coal and coal-derived materials. For this purpose, the former functional groups, including water molecules, are derivatized with reagents containing NMR-active nuclei such as {sup 31}P or {sup 119}Sn, while sulfur groups are derivatized with {sup 195}Pt NMR tagging reagents. Knowledge of the heteroatom composition of coals is necessary for the development of increasingly sophisticated coal processing technologies.

  19. Nuclear spin decoherence of neutral 31P donors in silicon: Effect of environmental 29Si nuclei

    NASA Astrophysics Data System (ADS)

    Petersen, Evan S.; Tyryshkin, A. M.; Morton, J. J. L.; Abe, E.; Tojo, S.; Itoh, K. M.; Thewalt, M. L. W.; Lyon, S. A.

    2016-04-01

    Spectral diffusion arising from 29Si nuclear spin flip-flops, known to be a primary source of electron spin decoherence in silicon, is also predicted to limit the coherence times of neutral donor nuclear spins in silicon. Here, the impact of this mechanism on 31P nuclear spin coherence is measured as a function of 29Si concentration using X -band pulsed electron nuclear double resonance. The 31P nuclear spin echo decays show that decoherence is controlled by 29Si flip-flops resulting in both fast (exponential) and slow (nonexponential) spectral diffusion processes. The decay times span a range from 100 ms in crystals containing 50% 29Si to 3 s in crystals containing 1% 29Si. These nuclear spin echo decay times for neutral donors are orders of magnitude longer than those reported for ionized donors in natural silicon. The electron spin of the neutral donors "protects" the donor nuclear spins by suppressing 29Si flip-flops within a "frozen core," as a result of the detuning of the 29Si spins caused by their hyperfine coupling to the electron spin.

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

    PubMed

    Clark, B J; Acker, M A; McCully, K; Subramanian, H V; Hammond, R L; Salmons, S; Chance, B; Stephenson, L W

    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 (31P-NMR) spectroscopy. After chronic electrical stimulation, five dogs underwent 31P-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 but 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. PMID:3348365

  1. Hypophosphite ion as a 31P nuclear magnetic resonance probe of membrane potential in erythrocyte suspensions.

    PubMed Central

    Kirk, K; Kuchel, P W; Labotka, R J

    1988-01-01

    Hypophosphorus acid has a single pKa of 1.1 and at physiological pH values it is therefore present almost entirely as the univalent hypophosphite ion. When added to a red cell suspension the ion crosses the cell membrane rapidly, via the anion exchange protein, and the intra- and extracellular populations of the ion give rise to separate 31P NMR resonances. From a single 31P NMR spectrum it was possible to determine the relative amounts of hypophosphite in the intra- and extracellular compartments and thereby estimate the corresponding concentrations. The ratio of intracellular to extracellular hypophosphite concentration was independent of the total hypophosphite concentration for cells suspended in NaCl solutions and was independent of hematocrit. The hypophosphite distribution ratio increased as extracellular NaCl was replaced iso-osmotically with citrate or sucrose, through it remained very similar to the corresponding hydrogen ion distribution ratio. Incorporation of the hypophosphite distribution ratio into the Nernst equation yielded an estimate of the membrane potential. For cells suspended in NaCl solutions the estimated potential was consistently around -10 mV. PMID:3207824

  2. In Vivo 31P Echo-Planar Spectroscopic Imaging of Human Calf Muscle

    NASA Astrophysics Data System (ADS)

    Wilhelm, Thomas; Bachert, Peter

    2001-03-01

    Localized phosphorus-31 NMR spectra of human calf muscle in vivo were obtained by means of echo-planar spectroscopic imaging (EPSI) with a 1.5-T whole-body scanner. The technique permits the measurement of two-dimensional 31P SI data at a minimum acquisition time of 2.4 s (8×8 voxels, TR=300 ms). With 9.4 min measurement time (TR=1100 ms, 64 averages) and 25×25×40 mm spatial resolution in vivo the 31P NMR signal-to-noise ratio (S/N) of the phosphocreatine (PCr) resonance was about 45; the multiplets of nucleoside 5‧-triphosphates were resolved. Spectral quality permits quantitative assessment of the PCr signal in a measurement time that is shorter by a factor of 2 or more than the minimum measurement time feasible with chemical-shift imaging. In a functional EPSI study with a time resolution of 20.5 s on the calf muscle of volunteers, spectra showed a 40% decrease of the PCr signal intensity (at rest: S/N≅12) upon exertion of the muscle.

  3. 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. PMID:27037615

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. The A31P missense mutation in cardiac myosin binding protein C alters protein structure but does not cause haploinsufficiency.

    PubMed

    van Dijk, Sabine J; Bezold Kooiker, Kristina; Mazzalupo, Stacy; Yang, Yuanzhang; Kostyukova, Alla S; Mustacich, Debbie J; Hoye, Elaine R; Stern, Joshua A; Kittleson, Mark D; Harris, Samantha P

    2016-07-01

    Mutations in MYBPC3, the gene encoding cardiac myosin binding protein C (cMyBP-C), are a major cause of hypertrophic cardiomyopathy (HCM). While most mutations encode premature stop codons, missense mutations causing single amino acid substitutions are also common. Here we investigated effects of a single proline for alanine substitution at amino acid 31 (A31P) in the C0 domain of cMyBP-C, which was identified as a natural cause of HCM in cats. Results using recombinant proteins showed that the mutation disrupted C0 structure, altered sensitivity to trypsin digestion, and reduced recognition by an antibody that preferentially recognizes N-terminal domains of cMyBP-C. Western blots detecting A31P cMyBP-C in myocardium of cats heterozygous for the mutation showed a reduced amount of A31P mutant protein relative to wild-type cMyBP-C, but the total amount of cMyBP-C was not different in myocardium from cats with or without the A31P mutation indicating altered rates of synthesis/degradation of A31P cMyBP-C. Also, the mutant A31P cMyBP-C was properly localized in cardiac sarcomeres. These results indicate that reduced protein expression (haploinsufficiency) cannot account for effects of the A31P cMyBP-C mutation and instead suggest that the A31P mutation causes HCM through a poison polypeptide mechanism that disrupts cMyBP-C or myocyte function. PMID:26777460

  9. 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 1-75mM 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). PMID:26838434

  10. 31P NMR Study of Filled Skutterudite CeOs4P12

    NASA Astrophysics Data System (ADS)

    Magishi, K.; Sugawara, H.; Saito, T.; Koyama, K.

    2012-12-01

    We report the results of the electrical resistivity ρ(T) and the 31P-NMR measurements on filled skutterudite CeOs4P12 in order to investigate the magnetic properties at low temperatures from a microscopic point of view. For the polycrystalline sample synthesized under high pressure (HP), ρ(T) increases with decreasing temperature. On the other hand, for the single crystal (SC), ρ(T) reveals a positive temperature dependence between room temperature and 200 K, and increases with decreasing temperature below 200 K. Also, 1/T1 obeys the activated temperature dependence 1/T1 propto exp(-Δ/kBT) above 160 K with an energy gap Δ/fB ~ 500 K and 540 K for the HP and the SC samples, which are slightly larger than that of a previous report.

  11. 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.

  12. 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. PMID:16830567

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

    PubMed

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

    2015-03-01

    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. PMID:25597861

  14. 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.

  15. Solid-State Quantitative (1)H and (31)P MRI of Cortical Bone in Humans.

    PubMed

    Seifert, Alan C; Wehrli, Felix W

    2016-06-01

    Magnetic resonance imaging (MRI) plays a pivotal role for assessment of the musculoskeletal system. It is currently the clinical modality of choice for evaluation of soft tissues including cartilage, ligaments, tendons, muscle, and bone marrow. By comparison, the study of calcified tissue by MRI is still in its infancy. In this article, we review the potential of the modality for assessment of cortical bone properties known to be affected in degenerative bone disease, with focus on parameters related to matrix and mineral densities, and porosity, by means of emerging solid-state (1)H and (31)P MRI techniques. In contrast to soft tissues, the MRI signal in calcified tissues has very short lifetime, on the order of 100 μs to a few milliseconds, demanding customized imaging approaches that allow capture of the signal almost immediately after excitation. The technologies described are suited for quantitatively imaging human cortical bone in specimens as well as in vivo in patients on standard clinical imagers, yielding either concentrations in absolute units when measured against a reference standard, or more simply, in the form of surrogate biomarkers. The two major water fractions in cortical bone are those of collagen-bound and pore water occurring at an approximately 3:1 ratio. Collagen-bound water density provides a direct quantitative measure of osteoid density. While at an earlier stage of development, quantification of mineral phosphorus by (31)P MRI yields mineral density and, together with knowledge of matrix density, should allow quantification of the degree of bone mineralization. PMID:27048472

  16. 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

  17. Abnormal skeletal muscle oxidative capacity after lung transplantation by 31P-MRS.

    PubMed

    Evans, A B; Al-Himyary, A J; Hrovat, M I; Pappagianopoulos, P; Wain, J C; Ginns, L C; Systrom, D M

    1997-02-01

    Although lung transplantation improves exercise capacity by removal of a ventilatory limitation, recipients' postoperative maximum oxygen uptake (VO2max) remains markedly abnormal. To determine if abnormal skeletal muscle oxidative capacity contributes to this impaired aerobic capacity, nine lung transplant recipients and eight healthy volunteers performed incremental quadriceps exercise to exhaustion with simultaneous measurements of pulmonary gas exchange, minute ventilation, blood lactate, and quadriceps muscle pH and phosphorylation potential by 31P-magnetic resonance spectroscopy (31P-MRS). Five to 38 mo after lung transplantation, peak VO2 was decreased compared with that of normal control subjects (6.7 +/- 0.4 versus 12.3 +/- 1.0 ml/min/kg, p < 0.001), even after accounting for differences in age and lean body weight. Neither ventilation, arterial O2 saturation nor mild anemia could account for the decrease in aerobic capacity. Quadriceps muscle intracellular pH (pH(i)) was more acidic at rest (7.07 +/- 0.01 versus 7.12 +/- 0.01 units, p < 0.05) and fell during exercise from baseline values at a lower metabolic rate (282 +/- 21 versus 577 +/- 52 ml/min, p < 0.001). Regressions for pH(i) versus VO2, phosphocreatine/inorganic phosphate ratio (PCr/Pi) versus VO2, and blood lactate versus pH(i) were not different. Among transplant recipients, the metabolic rate at which pH(i) fell correlated closely with VO2max (r = 0.87, p < 0.01). The persistent decrease in VO2max after lung transplantation may be related to abnormalities of skeletal muscle oxidative capacity. PMID:9032203

  18. 31P MRSI and 1H MRS at 7 T: initial results in human breast cancer.

    PubMed

    Klomp, Dennis W J; van de Bank, Bart L; Raaijmakers, Alexander; Korteweg, Mies A; Possanzini, Cecilia; Boer, Vincent O; van de Berg, Cornelius A T; van de Bosch, Maurice A A J; Luijten, Peter R

    2011-12-01

    This study demonstrates the feasibility of the noninvasive determination of important biomarkers of human (breast) tumor metabolism using high-field (7-T) MRI and MRS. (31) P MRSI at this field strength was used to provide a direct method for the in vivo detection and quantification of endogenous biomarkers. These encompass phospholipid metabolism, phosphate energy metabolism and intracellular pH. A double-tuned, dual-element transceiver was designed with focused radiofrequency fields for unilateral breast imaging and spectroscopy tuned for optimized sensitivity at 7 T. T(1) -weighted three-dimensional MRI and (1) H MRS were applied for the localization and quantification of total choline compounds. (31) P MRSI was obtained within 20 min per subject and mapped in three dimensions over the breast with pixel volumes of 10 mL. The feasibility of monitoring in vivo metabolism was demonstrated in two patients with breast cancer during neoadjuvant chemotherapy, validated by ex vivo high-resolution magic angle spinning NMR and compared with data from an age-matched healthy volunteer. Concentrations of total choline down to 0.4 mM could be detected in the human breast in vivo. Levels of adenosine and other nucleoside triphosphates, inorganic phosphate, phosphocholine, phosphoethanolamine and their glycerol diesters detected in glandular tissue, as well as in tumor, were mapped over the entire breast. Altered levels of these compounds were observed in patients compared with an age-matched healthy volunteer; modulation of these levels occurred in breast tumors during neoadjuvant chemotherapy. To our knowledge, this is the first comprehensive MRI and MRS study in patients with breast cancer, which reveals detailed information on the morphology and phospholipid metabolism from volumes as small as 10 mL. This endogenous metabolic information may provide a new method for the noninvasive assessment of prognostic and predictive biomarkers in breast cancer treatment. PMID

  19. 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. PMID:26832861

  20. 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.

  1. 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.

  2. 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

  3. A practical guide for the setup of a 1H-31P-13C double cross-polarization (DCP) experiment.

    PubMed

    Ciesielski, Wlodzimierz; Kassassir, Hassan; Potrzebowski, Marek J

    2011-01-01

    O-phospho-L-threonine is a convenient sample to setup a (1)H-(31)P-(13)C double cross-polarization (DCP) Hartmann-Hahn match. The (1)H-(31)P-(13)C technique is extremely sensitive to the rate of the sample spinning. Both zero-quantum (ZQ) and double-quantum (DQ) cross-polarization operate at an average spinning rate (6-7 kHz). At higher spinning rates (10 kHz), the DQCP mechanism dominates and leads to a reduction of signal intensity, in particular for lower (31)P RF field strength. The application of two shape pulses during the second cross-polarization greatly improves the signal to noise ratio allowing the recording of better quality spectra. (31)P-(13)C spectrally induced filtering in combination with cross-polarization (SPECIFIC-CP) experiments can be carried out under ZQCP and DQCP conditions if careful attention is paid to the choice of RF field amplitudes and carriers Ω. Application of 1D and 2D (1)H-(31)P-(13)C experiments is demonstrated on model samples; disodium ATP hydrate and O-phospho-L-tyrosine. PMID:21440422

  4. Metabolic engineering applications of in vivo sup 31 P and sup 13 C NMR studies of Saccharomyces cerevisiae

    SciTech Connect

    Shanks, J.V.

    1989-01-01

    With intent to quantify NMR measurements as much as possible, analysis techniques of the in vivo {sup 31}P NMR spectrum are developed. A systematic procedure is formulated for estimating the relative intracellular concentrations of the sugar phosphates in S. cerevisiae from the {sup 31}P NMR spectrum. In addition, in vivo correlation of inorganic phosphate chemical shift with the chemical shifts of 3-phosphoglycerate, {beta}-fructose 1,6-diphosphate, fructose 6-phosphate, and glucose 6-phosphate are determined. Also, a method was developed for elucidation of the cytoplasmic and vacuolar components of inorganic phosphate in the {sup 31}P NMR spectrum of S. cerevisiae. An in vivo correlation relating the inorganic phosphate chemical shift of the vacuole with the chemical shift of the resonance for pyrophosphate and the terminal phosphate of polyphosphate (PP{sub 1}) is established. Transient measurements provided by {sup 31}P NMR are applied to reg1 mutant and standard strains. {sup 31}P and {sup 13}C NMR measurements are used to analyze the performance of recombinant strains in which the glucose phosphorylation step had been altered.

  5. Contraction and recovery of living muscles studied by 31p nuclear magnetic resonance

    PubMed Central

    Gadian, D. G.; Dawson, M. Joan; Wilkie, D. R.

    1977-01-01

    1. Phosphorus nuclear magnetic resonance (31P NMR) can be used to measure the concentrations of phosphorus-containing metabolites within living tissue. We have developed methods for maintaining muscles in physiological condition, stimulating them and recording tension while at the same time accumulating their 31P NMR spectra. Experiments were performed on frog sartorii and frog and toad gastrocnemii at 4° C. 2. The NMR signals from 31P (the naturally occurring phosphorus) is weak, and signal averaging is required. In order to follow the time course of reactions it is necessary to maintain the muscles in a steady state for many hours while they are undergoing repeated contractions. Signals were accumulated in separate computer bins according to time after initiation of contraction. By these means spectra were obtained which corresponded to the different intervals during the contraction and recovery cycle. 3. In the absence of stimulation, the spectra of frog sartorius muscles and of their extracts indicated concentrations of adenosine triphosphate (ATP), phosphoryl creatine (PCr), inorganic orthophosphate (Pi) and sugar phosphates (sugar P) which are in reasonable agreement with the values obtained by chemical analysis. 4. We have confirmed that unidentified resonances representing unknown compounds appear in the spectra of both frog and toad muscle; one of these is much larger in spectra from toad than from frog. We have found an additional small, unidentified resonance which appears to be specific to toad muscle. 5. Spectra accumulated during actual contractions (1 s tetani every 2 min) did not differ dramatically from those accumulated throughout the 2 min cycle of contraction and partial recovery. 6. Following 25 s tetanii, approximately 20% of the PCr had been hydrolysed; it was then rebuilt exponentially with a half-time of about 10 min. The increase in [Pi] immediately after contraction and the time course of its disappearance corresponded to the changes in

  6. {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.

  7. Ex vivo identification of atherosclerotic plaque calcification by a 31P solid-state magnetic resonance imaging technique.

    PubMed

    Hallock, Kevin J; Hamilton, James A

    2006-12-01

    Calcified tissue is a common component of atherosclerotic plaques, and occurs most often in mature plaques. The process of calcification is a poorly understood risk factor that may contribute to a plaque's vulnerability to sudden rupture. In this study a solid-state imaging sequence, termed single-point imaging (SPI), was used to observe calcification directly in ex vivo atherosclerotic plaques. Standards were used to validate the ability of (31)P SPI to detect and differentiate calcification from crystalline cholesterol, phospholipids, and other plaque components. After suitable experimental parameters were found, human carotid specimens obtained by endarterectomy were imaged ex vivo by (31)P solid-state imaging and standard (1)H methods. In contrast to (1)H imaging methods, (31)P imaging detected only the calcification in the plaque. PMID:17089379

  8. 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

  9. A 13C{31P} REDOR NMR Investigation of the Role of Glutamic Acid Residues in Statherin-Hydroxyapatite Recognition

    PubMed Central

    Ndao, Moise; Ash, Jason T.; Breen, Nicholas F.; Goobes, Gil; Stayton, Patrick S.; Drobny, Gary P.

    2011-01-01

    The side chain carboxyl groups of acidic proteins found in the extra-cellular matrix (ECM) of mineralized tissues play a key role in promoting or inhibiting the growth of minerals such as hydroxyapatite (HAP), the principal mineral component of bone and teeth. Among the acidic proteins found in the saliva is statherin, a 43-residue tyrosine-rich peptide that is a potent lubricant in the salivary pellicle and an inhibitor of both HAP crystal nucleation and growth. Three acidic amino acids – D1, E4, and E5 – are located in the N-terminal 15 amino acid segment, with a fourth amino acid, E26, located outside the N-terminus. We have utilized 13C{31P} REDOR NMR to analyze the role played by acidic amino acids in the binding mechanism of statherin to the HAP surface by measuring the distance between the δ-carboxyl 13C spins of the three glutamic acid side chains of statherin (residues E4, E5, E26) and 31P spins of the phosphate groups at the HAP surface. 13C{31P} REDOR studies of glutamic-5-13C acid incorporated at positions E4 and E26 indicate a 13C–31P distance of more than 6.5 Å between the side chain carboxyl 13C spin of E4 and the closest 31P in the HAP surface. In contrast, the carboxyl 13C spin at E5 has a much shorter 13C–31P internuclear distance of 4.25±0.09 Å, indicating that the carboxyl group of this side chain interacts directly with the surface. 13C T1ρ and slow-spinning MAS studies indicate that the motions of the side chains of E4 and E5 are more restricted than that of E26. Together, these results provide further insight into the molecular interactions of statherin with HAP surfaces. PMID:19678690

  10. High energy nucleus-nucleus collisions

    NASA Technical Reports Server (NTRS)

    Wosiek, B.

    1986-01-01

    Experimental results on high energy nucleus-nucleus interactions are presented. The data are discussed within the framework of standard super-position models and from the point-of-view of the possible formation of new states of matter in heavy ion collisions.

  11. (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. PMID:20329795

  12. 31P NMR spectroscopy of rat organs, in situ, using chronically implanted radiofrequency coils.

    PubMed Central

    Koretsky, A P; Wang, S; Murphy-Boesch, J; Klein, M P; James, T L; Weiner, M W

    1983-01-01

    A technique for making 31P NMR spectroscopic measurements in rat kidney, heart, and liver in vivo is presented. Two-turn solenoid coils were surgically implanted around the organ sufficiently in advance of NMR experiments to allow recovery of the animal. These chronically implanted coils allowed acquisition of high-resolution spectra at 40.5 and 97.3 MHz. No resolution improvement occurred at the higher field. Spectra were stable for up to 24 hr, during which time a variety of experiments could be performed. By accumulating spectra at 10-min intervals, the effects of intraperitoneal fructose injections were monitored; in kidney and liver, a rapid increase in sugar phosphates at the expense of Pi and ATP resulted. Fructose had no effect on heart metabolite levels. Spectra from the heart in vivo were obtained at systole and diastole by gating the spectrometer to the aortic pressure wave; no differences in phosphate metabolites were detected. Finally, saturation transfer techniques were used to monitor the rate of ATP synthesis in the kidney. The unidirectional rate constant for the conversion of Pi to ATP was 0.12 +/- 0.03 sec-1. Images PMID:6584867

  13. 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.

  14. Molybdenum modified phosphate glasses studied by 31P MAS NMR and Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Szumera, Magdalena

    2015-02-01

    Glasses have been synthesized in the system P2O5sbnd SiO2sbnd K2Osbnd MgOsbnd CaO modified by addition of MoO3. Glasses were prepared by conventional fusion method from 40 g batches. The influence of Mo-cations on the analysed glass structure was investigated by means of Raman and 31P MAS-NMR techniques. It has been found that molybdate units can form Mo[MoO4/MoO6]sbnd Osbnd P and/or Mo[MoO4/MoO6]sbnd Osbnd Si bonds with non-bridging oxygens atoms of Q2 methaphosphate units, resulting in the transformation of chain methaphosphate structure into pyrophosphate and finally into orthophosphate structure. It has been also found that increasing amount of MoO3 in the structure of investigated glasses causes their gradual depolymerization and molybdenum ions in the analysed glass matrix act as modifying cations.

  15. 31P-nuclear magnetic resonance studies of chronic myocardial ischemia in the Yucatan micropig.

    PubMed

    Rath, D P; Bailey, M; Zhang, H; Jiang, Z; Abduljalil, A M; Weisbrode, S; Hamlin, R L; Robitaille, P M

    1995-01-01

    In this work, an x-irradiation/high fat/high cholesterol diet-induced atherogenic model was invoked to examine the effects of severe diffuse atherosclerosis on myocardial metabolism in the in vivo porcine heart. This model was studied using spatially localized 31P-nuclear magnetic resonance (NMR) to monitor pH and the levels of inorganic phosphate, phosphomonoesters, creatine phosphate, and adenosine triphosphate as a function of workload transmurally in control swine and in animals suffering from chronic ischemic heart disease. These preliminary studies revealed that the development of severe atherosclerosis and the accompanying chronically diseased state produce changes in high energy phosphates and that increases in rate pressure products result in demonstrable signs of ischemia in the myocardium which span the entire left ventricular wall. Ischemic changes include a global increase in inorganic phosphate and corresponding decreases in creatine phosphate, ATP, and pH. Importantly, changes in intracellular pH are noted with even the slightest increase in workload suggesting that these diseased hearts display elevated glycolytic activity. By challenging these animals with increased cardiac workload, we directly visualize how the chronically compromised heart responds to severe oxygen challenges in a clinically relevant model of this situation. PMID:7814609

  16. 31P-nuclear magnetic resonance studies of chronic myocardial ischemia in the Yucatan micropig.

    PubMed Central

    Rath, D P; Bailey, M; Zhang, H; Jiang, Z; Abduljalil, A M; Weisbrode, S; Hamlin, R L; Robitaille, P M

    1995-01-01

    In this work, an x-irradiation/high fat/high cholesterol diet-induced atherogenic model was invoked to examine the effects of severe diffuse atherosclerosis on myocardial metabolism in the in vivo porcine heart. This model was studied using spatially localized 31P-nuclear magnetic resonance (NMR) to monitor pH and the levels of inorganic phosphate, phosphomonoesters, creatine phosphate, and adenosine triphosphate as a function of workload transmurally in control swine and in animals suffering from chronic ischemic heart disease. These preliminary studies revealed that the development of severe atherosclerosis and the accompanying chronically diseased state produce changes in high energy phosphates and that increases in rate pressure products result in demonstrable signs of ischemia in the myocardium which span the entire left ventricular wall. Ischemic changes include a global increase in inorganic phosphate and corresponding decreases in creatine phosphate, ATP, and pH. Importantly, changes in intracellular pH are noted with even the slightest increase in workload suggesting that these diseased hearts display elevated glycolytic activity. By challenging these animals with increased cardiac workload, we directly visualize how the chronically compromised heart responds to severe oxygen challenges in a clinically relevant model of this situation. Images PMID:7814609

  17. 31P-NMR studies of isolated adult heart cells: effect of myoglobin inactivation.

    PubMed

    Gupta, R K; Wittenberg, B A

    1991-10-01

    31P nuclear magnetic resonance (NMR) studies of isolated adult rat heart cells revealed that the cells maintained high-energy phosphates for up to 6 h in polyamide hollow fibers perfused with well-oxygenated nutrient medium. Glucose plus pyruvate superfused heart cells maintained [phosphocreatine]/[ATP] at 1.4 +/- 0.1, internal pH at 7.09 +/- 0.04 (external pH = 7.25), and intracellular free Mg2+ at 0.51 +/- 0.04 mM. In glucose-containing media, hypoxia was accompanied by a reversible decrease in intracellular ATP and phosphocreatine of approximately 50% and 80%, respectively, while the intracellular free Mg2+ was reversibly increased by 40%. However, inhibition of glycolysis by iodoacetate in aerobic pyruvate-containing medium did not significantly alter high-energy phosphate content. Inactivation of intracellular myoglobin with 1-2 mM sodium nitrite, which reduces the steady-state respiratory oxygen consumption rate by 30%, caused a significant (30%) decrease in intracellular phosphocreatine peak, which was reversed upon removal of sodium nitrite. The nitrite-induced decrease in phosphocreatine was also observed in iodoacetate-treated myocytes but not in oligomycin-treated cells. These results indicate that functional myoglobin enhances high-energy phosphate synthesis in well-oxygenated myocytes. PMID:1928397

  18. 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.

  19. In vivo 31P and multilabel 13C NMR measurements for evaluation of plant metabolic pathways.

    PubMed

    Rijhwani, S K; Ho, C H; Shanks, J V

    1999-01-01

    Reliable measurements of intracellular metabolites are useful for effective plant metabolic engineering. This study explored the application of in situ 31P and 13C NMR spectroscopy for long-term measurements of intracellular pH and concentrations of several metabolites in glycolysis, glucan synthesis, and central carbon metabolic pathways in plant tissues. An NMR perfusion reactor system was designed to allow Catharanthus roseus hairy root cultures to grow for 3-6 weeks, during which time NMR spectroscopy was performed. Constant cytoplasmic pH (7.40+/-0.06), observed during the entire experiment, indicated adequate oxygenation. 13C NMR spectroscopy was performed on hairy root cultures grown in solutions containing 1-13C-, 2-13C-, and 3-13C-labeled glucose in separate experiments and the flow of label was monitored. Activities of pentose phosphate pathways, nonphotosynthetic CO2 fixation, and glucan synthesis pathways were evident from the experimental results. Scrambling of label in glucans also indicated recycling of triose phosphate and their subsequent conversion to hexose phosphates. PMID:10935751

  20. 31P magnetic resonance phospholipid profiles of neoplastic human breast tissues.

    PubMed Central

    Merchant, T. E.; Meneses, P.; Gierke, L. W.; Den Otter, W.; Glonek, T.

    1991-01-01

    Phospholipids from malignant, benign and noninvolved human breast tissues were extracted by chloroform-methanol (2:1) and analysed by 31P MR spectroscopy at 202.4 MHz. Thirteen phospholipids were identified as constituents of the profiles obtained among the 55 tissue specimens analysed. Observed patterns in phospholipid tissues profiles were distinct, allowing qualitative characterisation of the three tissue groups. Multivariate analysis of lysophosphatidylcholine (LPC) and an uncharacterised phospholipid were shown to be independently significant in predicting benign tissue histology as either fibrocystic disease or fibroadenoma in 92% of cases. Univariate analysis of relative mole-percentage of phosphorus concentrations of individual phospholipids using the Scheffé comparison procedure revealed that in malignant tissues, phosphatidylethanolamine was significantly elevated compared to benign (+ 32%) and noninvolved tissues (+ 22%). Phosphatidylinositol (+ 33%) and phosphatidylcholine plasmalogen (PC plas) (+ 25%) were increased in malignant compared to benign and LPC was decreased (-44%) in malignant compared to noninvolved. LPC was significantly depressed (-39%) in benign tissue compared to normal. Phospholipid indices computed to further characterise the three tissue groups showed PC plas/PC elevated in malignant tissue compared to benign and PE plas/PE depressed in malignant tissue compared to noninvolved. These findings support previous investigations reporting that the alkyl-phospholipid analogues of phosphatidylcholine are released by malignant tissues and that levels of ethanolamine are elevated in malignant tissues. Indices describing the choline-containing phospholipids showed that these lipids are depressed significantly in malignant tissue relative to healthy tissue. PMID:2039694

  1. Singlet-triplet separations measured by [sup 31]P[l brace][sup 1]H[r brace] NMR: Applications to quadruply bonded dimolybdenum and ditungsten complexes

    SciTech Connect

    Cotton, F.A.; Eglin, J.L.; Bo Hong; James, C.A. )

    1993-05-12

    A series of quadruply bonded dimolybdenum and ditungsten compounds M[sub 2]X[sub 4](PP)[sub 2] (M = Mo, W; PP = bidentate phosphine ligands; X = Cl, Br, I) with internal rotational angles [chi] varying from 0.0 to 69.4[degrees] have been studied. Their [sup 31]P[l brace][sup 1]H[r brace] NMR spectra are characterized by their temperature-dependent shifts and line widths that broaden with increasing temperature. A nonlinear, least-squares fit of this temperature dependence of the paramagnetic shifts for their NMR signals allows the evaluation of the singlet-triplet energy separation ([minus]2J), the diamagnetic shift (H[sub dia]), and the electron-nucleus hyperfine coupling constant (A). The singlet-triplet energy separations for all the compounds investigated are found to be in the range 1200-3000 cm[sup [minus]1]. It is now clearly established that the ground state remains [sup 1]A[sub 1g] ([delta][sup 2]) even at [chi] = 45[degrees], where [sup 3]A[sub 2u] ([delta][delta]*) lies 1230 cm[sup [minus]1] above it. The [delta]-bond energy and electronic [delta]-barrier can also be experimentally estimated as 13.8[+-]0.5 kcal mol[sup [minus]1] and 10.3[+-]0.5 kcal mol[sup [minus]1], respectively. 32 refs., 3 figs., 1 tab.

  2. [ 31P]NMR measurements of hexokinase activity in intact red blood cells with 2-deoxyglucose as substrate

    NASA Astrophysics Data System (ADS)

    Halabi, F.; Seguin, J. P.; Fonroget, J.; Goethals, G.

    [ 31P] NMR spectroscopy is demonstrated to be a suitable tool to follow the time course of 2-deoxyglucose-6-phosphate in intact human erythrocytes incubated with 2-deoxyglucose. It allowed to determine hexokinase Vmax and K m in near physiological conditions.

  3. 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.

  4. Intermolecular (119)Sn,(31)P Through-Space Spin-Spin Coupling in a Solid Bivalent Tin Phosphido Complex.

    PubMed

    Arras, Janet; Eichele, Klaus; Maryasin, Boris; Schubert, Hartmut; Ochsenfeld, Christian; Wesemann, Lars

    2016-05-01

    A bivalent tin complex [Sn(NP)2] (NP = [(2-Me2NC6H4)P(C6H5)](-)) was prepared and characterized by X-ray diffraction and solution and solid-state nuclear magnetic resonance (NMR) spectroscopy. In agreement with the X-ray structures of two polymorphs of the molecule, (31)P and (119)Sn CP/MAS NMR spectra revealed one crystallographic phosphorus and tin site with through-bond (1)J((117/119)Sn,(31)P) and through-space (TS)J((117/119)Sn,(31)P) spin-spin couplings. Density functional theory (DFT) calculations of the NMR parameters confirm the experimental data. The observation of through-space (TS)J((117/119)Sn,(31)P) couplings was unexpected, as the distances of the phosphorus atoms of one molecule and the tin atom of the neighboring molecule (>4.6 Å) are outside the sum of the van der Waals radii of the atoms P and Sn (4.32 Å). The intermolecular Sn···P separations are clearly too large for bonding interactions, as supported by a natural bond orbital (NBO) analysis. PMID:27071033

  5. Nuclear Spin Polarization of Phosphorus Donors in Silicon. Direct Evidence from 31P-Nuclear Magnetic Resonance

    NASA Astrophysics Data System (ADS)

    Gumann, Patryk; Ramanathan, Chandrasekhar; Patange, Om; Moussa, Osama; Thewalt, Mike; Riemann, Helge; Abrosimov, Nikolay; Becker, Peter; Pohl, Hans-Joachim; Itoh, Kohei; Cory, David G.

    2014-03-01

    We experimentally demonstrate the optical hyperpolarization and coherent control of 31P, nuclear spins in single crystal silicon via the inductive readout of the nuclear magnetic resonance (NMR) signal of 31P at a concentration of 1.5 x 1015 cc-1. The obtained polarization is sufficient the 31P spin polarization of 1.17 x 1015 in a 10 mm x 10 mm sample, observed in one FID with signal-to-noise ration of 113. The linewidth is 800 Hz. The Hahn echo pulse sequence reveals a 31P T2 time of 0.42 s at 1.6 K, which was extended by the Carr Purcell cycle to 1.2 s at the same temperature. The maximum build-up of the nuclear polarization was achieved within ~577 seconds, at 4.2 K, in 6.7 T, using optical excitations provided by an infra-red laser. This work has been supported by CERC Canada.

  6. 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. PMID:26248272

  7. 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

  8. Application of (31P) NMR in analyzing the degradation efficiency of organic phosphorus degrading-bacteria.

    PubMed

    Lu, Yang; Sun, Xin; Ji, Si-Yao; Wang, Jian-Feng; Huang, Yao-Jian; Zhao, Yu-Fen; Xu, Peng-Xiang

    2007-07-01

    HPLC and HPLC-MS are the fastest and most accurate techniques for analysis of organic phosphorus pesticide (OPP) at the present time. Using these techniques, 14 strains of methamidopho (MAP) degrading-bacteria from the area contaminated with MAP have been identified. The results from HPLC and HPLC-MS analyses showed that the highest degradation rate was 73% after 7 days. In order to determine what metabolites will be formed after degradation, a key issue that has been neglected for a long time, we used ((31)P) NMR to track the degradation process. The results showed that different strains produced different metabolites. Ten strains were divided into three groups (groups A, B and C) by their metabolic profiling. Strains in group A degraded MAP into phosphor acid by breaking down all P-N, P-O and P-S bonds in 7 days. Strains in groups B and C had only broken down partially P-N and P-S bonds at the same time. Therefore, the bacterial strains in group A had a greater application potential than the other two groups. In addition, most metal phosphates are unsolvable in water. The analysis of X-ray showed, that the phosphate radicals generated by bacterial degradation induce crystallogenesis of heavy metal salts in water phase and also cause the chemical sedimentation of their crystals. Furthermore, these crystals are hydrogen phosphates. The results suggested that the MAP-degrading bacteria could be used for cleaning up not only the organic phosphorous pesticide contamination but also the phosphorous and heavy metal contamination in water environment simultaneously. PMID:17072553

  9. Regional Differences of Metabolic Response During Dynamic Incremental Exercise by (31)P-CSI.

    PubMed

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

    2016-01-01

    The aim of this study was to detect the differences in muscle metabolic response of the quadriceps during incremental dynamic knee exercise using regional (31)Phosphorus Chemical Shift Imaging ((31)P-CSI). Sixteen healthy men participated in this study (age 28 ± 5 years, height 171.4 ± 3.9 cm, weight 67.1 ± 9.8 kg). The experiments were carried out with a 1.5-T superconducting magnet with a 5-in. diameter circular surface coil. The subjects performed isometric unilateral knee extension exercise to detect their maximum voluntary contraction (MVC) in prone position. Then they performed dynamic unilateral knee extension exercise in the magnet at 10, 20, 30 and 40 % of their MVC with the transmit-receive coil placed under the right quadriceps. The subjects pulled down a rope with the adjusted weight attached to the ankle at a frequency of 0.5 Hz for 380 s. Intracellular pH (pHi) was calculated from the median chemical shift of the inorganic phosphate (Pi) peak relative to phosphocreatine (PCr). The quadriceps were divided into three regions, (1) medial, (2) anterior, (3) lateral, and in comparison, there was no significant difference in Pi/PCr nor in pHi between regions, except Pi/PCr of the medial region was significantly higher than the anterior region at maximum intensity (p < 0.05). These results suggest that regional muscle metabolic response is similar in the quadriceps except at maximum intensity. PMID:27526153

  10. Multimodal neuroimaging provides a highly consistent picture of energy metabolism, validating 31P MRS for measuring brain ATP synthesis

    PubMed Central

    Chaumeil, Myriam M.; Valette, Julien; Guillermier, Martine; Brouillet, Emmanuel; Boumezbeur, Fawzi; Herard, Anne-Sophie; Bloch, Gilles; Hantraye, Philippe; Lebon, Vincent

    2009-01-01

    Neuroimaging methods have considerably developed over the last decades and offer various noninvasive approaches for measuring cerebral metabolic fluxes connected to energy metabolism, including PET and magnetic resonance spectroscopy (MRS). Among these methods, 31P MRS has the particularity and advantage to directly measure cerebral ATP synthesis without injection of labeled precursor. However, this approach is methodologically challenging, and further validation studies are required to establish 31P MRS as a robust method to measure brain energy synthesis. In the present study, we performed a multimodal imaging study based on the combination of 3 neuroimaging techniques, which allowed us to obtain an integrated picture of brain energy metabolism and, at the same time, to validate the saturation transfer 31P MRS method as a quantitative measurement of brain ATP synthesis. A total of 29 imaging sessions were conducted to measure glucose consumption (CMRglc), TCA cycle flux (VTCA), and the rate of ATP synthesis (VATP) in primate monkeys by using 18F-FDG PET scan, indirect 13C MRS, and saturation transfer 31P MRS, respectively. These 3 complementary measurements were performed within the exact same area of the brain under identical physiological conditions, leading to: CMRglc = 0.27 ± 0.07 μmol·g−1·min−1, VTCA = 0.63 ± 0.12 μmol·g−1·min−1, and VATP = 7.8 ± 2.3 μmol·g−1·min−1. The consistency of these 3 fluxes with literature and, more interestingly, one with each other, demonstrates the robustness of saturation transfer 31P MRS for directly evaluating ATP synthesis in the living brain. PMID:19234118

  11. Nucleus-nucleus scattering at high energies

    NASA Technical Reports Server (NTRS)

    Franco, V.; Varma, G. K.

    1977-01-01

    Nucleus-nucleus scattering is treated in the Glauber approximation. The usual optical limit result, generally thought to improve as the number of nucleons in the colliding nuclei increases, is found to be the first term of a series which diverges for large nuclei. Corrections to the optical limit are obtained which provide a means of performing realistic calculations for collisions involving light nuclei. Total cross section predictions agree well with recent measurements.

  12. Superiority of blood over saline resuscitation from hemorrhagic shock: a 31P magnetic resonance spectroscopy study.

    PubMed Central

    Mann, D V; Robinson, M K; Rounds, J D; DeRosa, E; Niles, D A; Ingwall, J S; Wilmore, D W; Jacobs, D O

    1997-01-01

    OBJECTIVE: To study the relation between blood and saline administration, postresuscitation hematocrit (Hct) level, and metabolic recovery after hemorrhagic shock. SUMMARY BACKGROUND DATA: It is generally believed that crystalloid can be substituted, in whole or in part, for blood during resuscitation of hemorrhagic shock. This is based on the belief that Hct can be safely reduced but should not fall below a critical level. METHODS: Male rats weighing 200 g were subjected to an isobaric hemorrhagic shock at a mean arterial pressure of 30 mmHg for 14 minutes, after which they were randomized to one of three resuscitation regimens. Control group (n = 36) were resuscitated by return of all shed blood. Mid-Hct (n = 39) and low-Hct (n = 60) groups were depleted of one third and one half of their circulating blood volumes, respectively, and were resuscitated with three times that volume of normal saline. Skeletal muscle intracellular energetics and pH were measured serially using 31P magnetic resonance spectroscopy at baseline, during shock, and after resuscitation. Arterial blood was sampled at the same time points. The number of surviving animals in each group at 24 hours was recorded. RESULTS: After resuscitation, surviving rats in the low-Hct group demonstrated a greater consumption of high-energy phosphocreatine stores than did the other groups (control = 0.479 +/- 0.003, mid-Hct = 0.465 +/- 0.004, low-Hct = 0.457 +/- 0.007, mean +/- standard error of the mean; p < 0.01 low-Hct vs. other groups by analysis of variance). The rats that received saline resuscitation developed a relative intracellular acidosis (control = 7.29 +/- 0.02, mid-Hct = 7.25 +/- 0.02, low-Hct = 7.23 +/- 0.02; p < 0.05 controls vs. other groups by analysis of variance). At 24 hours, the death rates were significantly different among the groups: control = 1 of 36 rats (2.8%), mid-Hct = 6 of 39 (15.4%), and low-Hct = 14 of 60 (23.3%) (p < 0.05 by chi square analysis). CONCLUSION: The oxygen

  13. Discovery and Classification of Nova in M31 : P60-M31-081230

    NASA Astrophysics Data System (ADS)

    Kasliwal, M. M.; Rau, A.; Salvato, M.; Cenko, S. B.; Ofek, E. O.; Quimby, R.; Kulkarni, S. R.

    2009-01-01

    On UT 2008 Dec 30.207, P60-FasTING (Palomar 60-inch Fast Transients In Nearby Galaxies) discovered an optical transient in M31 at RA(J2000) = 00:43:05.027, DEC(J2000)=+41:17:52.25, offset from the nucleus by 233.4"E,103.8"N. P60-M31-081230 had a brightness of g = 20.5 +/- 0.2 at discovery. It was not detected by P60 to g > 22.0 on Dec 29.140. There is no counterpart in SIMBAD. Follow-up spectroscopy with the Double Beam Spectrograph on the Palomar Hale telescope on Dec 31.104 revealed prominent Balmer emission and strong P Cygni profiles of several Fe II lines.

  14. Discovery of Possible Nova in M31 : P60-M31-080915

    NASA Astrophysics Data System (ADS)

    Kasliwal, M. M.; Cenko, S. B.; Rau, A.; Ofek, E. O.; Quimby, R.; Kulkarni, S. R.

    2008-09-01

    On UT 2008 Sep 15.36, P60-FasTING (Palomar 60-inch Fast Transients In Nearby Galaxies) discovered a possible nova in M31 at RA(J2000) = 00:42:51.42, DEC(J2000) = 41:01:54.0, offset from the nucleus by 1.34'E, 14.24'S. P60-M31-080915 has a brightness of g=19.1 +/- 0.2 at discovery (photometric calibration wrt NOMAD catalog). It is further confirmed to rise to g=17.6 on Sep 16.16. It is not detected, with 3-sigma upper limits of g > 20.5, g > 21.0, g > 21.7 on Sep 14.16, Sep 13.39 and Sep 11.39 respectively.

  15. Discovery of Possible Nova in M31 : P60-M31-080913

    NASA Astrophysics Data System (ADS)

    Kasliwal, M. M.; Cenko, S. B.; Rau, A.; Ofek, E. O.; Quimby, R.; Kulkarni, S. R.

    2008-09-01

    On UT 2008 Sep 13.18, P60-FasTING (Palomar 60-inch Fast Transients In Nearby Galaxies) discovered a possible nova in M31 at RA(J2000) = 00:41:46.72, DEC(J2000) = 41:07:52.1, offset from the nucleus by 10.8'W, 8.3'S. P60- M31-080913 has a brightness of g = 19.0 +/- 0.2 at discovery (photometric calibration wrt NOMAD catalog). It is further confirmed to rise to g=18.1 on Sep 14.18. It is not detected to g > 21.5 on images obtained on Sep 12.30.

  16. 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.

  17. Characterization of phosphorus in sludges and sludge amended soils using /sup 31/P nuclear magnetic resonance spectroscopy

    SciTech Connect

    Hinedi, Z.R.

    1987-01-01

    /sup 31/P NMR spectroscopy was an effective tool in the characterization of phosphorus (P) in municipal sewage sludges and sludge amended soils. Waste activated and aerobically digested sludges contained higher percentages of organic P than anaerobically digested sludges. The /sup 31/P Cross Polarization Magic Angle Spinning (/sup 31/P CP MAS) spectrum of an aerobically digested sludge indicated the presence of a significant organic P fraction over the inorganic P fraction. The /sup 31/P NMR spectra of sludge-borne phospholipids dissolved in cholate, to which a complexing agent was added, were found to be better resolved than those dissolved in chloroform. Phytic acid and ribonucleic acid were shown to be constituents of organic P in sludges based upon their susceptibility to different phosphoric ester hydrolases. Sludge amended soils were incubated to examine the transformations of sludge-borne P in soils. It was found that soil pH affected the biodegradation of organic P as well as that of pyrophosphate. Phosphorus-monoesters and pyrophosphates hydrolyzed after 70 days of incubation under alkaline soil condition while they persisted beyond 140 days of incubation under acid soil condition. The P-diesters completely hydrolyzed after 28 days of incubation under acid and alkaline soil conditions. The solubility study showed that the P in a sludge amended soil was undersaturated with respect to Ca-P, Fe-P and Al-P minerals considered. The finding suggested that the activity of the P solid phase under study might be less than unity which would be indicative of a coprecipitated solid solution.

  18. 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.

  19. 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

  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. Protein analysis by 31p NMR spectroscopy in ionic liquid: quantitative determination of enzymatically created cross-links.

    PubMed

    Monogioudi, Evanthia; Permi, Perttu; Filpponen, Ilari; Lienemann, Michael; Li, Bin; Argyropoulos, Dimitris; Buchert, Johanna; Mattinen, Maija-Liisa

    2011-02-23

    Cross-linking of β-casein by Trichoderma reesei tyrosinase (TrTyr) and Streptoverticillium mobaraense transglutaminase (Tgase) was analyzed by (31)P nuclear magnetic resonance (NMR) spectroscopy in ionic liquid (IL). According to (31)P NMR, 91% of the tyrosine side chains were cross-linked by TrTyr at high dosages. When Tgase was used, no changes were observed because a different cross-linking mechanism was operational. However, this verified the success of the phosphitylation of phenolics within the protein matrix in the IL. Atomic force microscopy (AFM) in solid state showed that disk-shaped nanoparticles were formed in the reactions with average diameters of 80 and 20 nm for TrTyr and Tgase, respectively. These data further advance the current understanding of the action of tyrosinases on proteins on molecular and chemical bond levels. Quantitative (31)P NMR in IL was shown to be a simple and efficient method for the study of protein modification. PMID:21218836

  2. (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

  3. 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

  4. Analysis of 31P MR spectroscopy data using artificial neural networks for longitudinal evaluation of muscle diseases: dermatomyositis.

    PubMed

    Park, J H; Kari, S; King, L E; Olsen, N J

    1998-01-01

    Classical myopathic dermatomyositis (DM) is a chronic autoimmune disease characterized by an erythematous rash and severe, proximal muscle weakness. A disease variant, amyopathic DM, presents with the typical rash but without clinical evidence of muscle weakness. Prednisone and immunosuppressive drugs alleviate symptoms in many patients. Accurate longitudinal evaluations of patients are important to limit serious side effects of these drugs, including osteoporosis, cataracts, and growth inhibition. Metabolic abnormalities detected with 31P magnetic resonance spectroscopy (MRS) provide the best quantitative data for evaluating these patients. With 31P MRS, the levels of inorganic phosphate (Pi), phosphocreatine (PCr), ATP, and phosphodiesters (PDE) were determined in the quadricep muscles of patients during rest and exercise. Artificial neural network (ANN) analyses of these data were previously used for accurate classification of patients with myopathic or amyopathic DM and normal controls. In the present investigation, an artificial neural network was employed for further analysis of the 31P metabolite levels in quantitative, longitudinal evaluations of the extent (percent) of clinical improvement or deterioration during treatment with prednisone and immunosuppressive drugs. The ANN results showed that adult patients in a severe myopathic state could improve with treatment to a clinical status of amyopathic DM. In contrast, severely weak juvenile patients in the myopathic state recovered to normal status. One juvenile patient did not improve and remained in the myopathic state. Additionally, a serious clinical relapse in an amyopathic patient was predicted with serial ANN analyses well in advance of the actual clinical event. These network analyses show potential utility for clinical applications in muscle diseases. PMID:9719579

  5. 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

  6. Intracellular pH of perfused single frog skin: combined 19F- and 31P-NMR analysis.

    PubMed

    Civan, M M; Lin, L E; Peterson-Yantorno, K; Taylor, J; Deutsch, C

    1984-11-01

    Intracellular pH (pHc) has been determined in frog skin by applying two different methods of pH measurement, 19F and 31P nuclear magnetic resonance (NMR) analysis, to the same tissues. Results from both NMR approaches confirm an observation by Lin, Shporer, and Civan [Am. J. Physiol. 248 (Cell Physiol. 17): 1985] that acidification of the extracellular medium reverses the sign of the pH gradient present under baseline conditions. The fluorinated probe, alpha-(difluoromethyl)-alanine methyl ester, was introduced into the epithelial cells by preincubating skins for 4.7-10.4 h at room temperature in Ringer solutions containing 1 mM ester. The free amino acid was subsequently released by intracellular esterase activity, thus providing a high enough probe concentration for NMR analysis to be practicable. From measurements of short-circuit current and transepithelial resistance under base-line and experimental conditions and the appearance of phosphocreatine (PCr) in the 31P spectrum of preloaded tissues, the fluorinated probe appears to be nontoxic to frog skin. Measurement of the chemical shift of methylphosphonate relative to PCr permitted calculation of extracellular pH. Estimation of the intracellular pH was performed both by measurement of the chemical shift of inorganic phosphate (Pi) relative to PCr and by measurement of the central peak spacing of the 19F spectrum. From four direct comparisons of the two techniques in two experiments, the difference in the estimated pH was only 0.03 +/- 0.07 pH units, supporting the concept that 31P-NMR analysis is a valid method of measuring pH in this tissue. PMID:6496729

  7. Local structure of spin Peierls compound TiPO4: 47/49Ti and 31P NMR study

    NASA Astrophysics Data System (ADS)

    Stern, Raivo; Heinmaa, Ivo; Leitmäe, Alexander; Joon, Enno; Tsirlin, Alexander; Kremer, Reinhard; Glaum, Robert

    TiPO4 structure is made of slightly corrugated TiO2 ribbon chains of edge-sharing TiO6 octahedra. The almost perfect 1D spin 1/2 Ti3 + chains are well separated by PO4 tetrahedra. By magnetic susceptibility and MAS-NMR measurements [1] it was shown that TiPO4 has nonmagnetic singlet ground state with remarkably high Spin-Peierls (SP) transition temperature. The high-T magnetic susceptibility of TiPO4 follows well that of a S =1/2 Heisenberg chain with very strong nearest-neighbor AF spin-exchange coupling constant of J =965K. On cooling TiPO4 shows two successive phase transitions at 111K and 74K, with incommensurate (IC) SP phase between them. We studied local structure and dynamics in TiPO4 single crystal using 47/49Ti and 31P NMR in the temperature range 40K to 300K, and determined the principal values and orientation of the magnetic shift tensors for 31P and 47,49Ti nuclei. Since 47,49Ti (S =5/2 and S =7/2, respectively) have quadrupolar moments, we also found the principal axis values and orientations of the electric field gradient (efg) tensor in SP phase and at 295K. In SP phase the structure contains 2 magnetically inequivalent P sites and only one Ti site. From the T-dependence of the relaxation rate of 31P and 47Ti nuclei we determined activation energy Ea = 550 K for spin excitations in SP phase. J. Law et al ., PRB 83, 180414(R) (2011).

  8. Measurement of changes in high-energy phosphates in the cardiac cycle using gated 31P nuclear magnetic renonance.

    PubMed Central

    Fossel, E T; Morgan, H E; Ingwall, J S

    1980-01-01

    Levels of the high-energy phosphate-containing compounds, ATP and creatine phosphate, and of inorganic phosphate (Pi) 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 31P 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. Pi varied inversely with the high-energy phosphates. PMID:6932041

  9. 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.

  10. [sup 31]P and [sup 27]Al NMR investigations of highly acidic, aqueous solutions containing aluminum and phosphorus

    SciTech Connect

    Mortlock, R.F.; Bell, A.T.; Radke, C.J. Univ. of California, Berkeley )

    1993-01-21

    [sup 31]P and [sup 27]Al NMR spectroscopies have been used to characterize acidic, aqueous solutions of orthophosphoric acid, aluminum chloride, and tetramethylammonium (TMA) hydroxide. The final compositions of the solutions range from 0.1 to 1 mol % P, 0.0 to 20 mol % HCl, P/Al = 0.1 to 20, and P/(TMA)[sub 2]O = 2 to 20. Soluble aluminophosphate cations form reactions of hexaaqua Al monomeric cations, [Al(H[sub 2]O)[sub 6

  11. The Nucleus Introduced

    PubMed Central

    Pederson, Thoru

    2011-01-01

    Now is an opportune moment to address the confluence of cell biological form and function that is the nucleus. Its arrival is especially timely because the recognition that the nucleus is extremely dynamic has now been solidly established as a paradigm shift over the past two decades, and also because we now see on the horizon numerous ways in which organization itself, including gene location and possibly self-organizing bodies, underlies nuclear functions. PMID:20660024

  12. A solid-state 31P-NMR investigation of the allosteric transition in glycogen phosphorylase b.

    PubMed Central

    Challoner, R; McDowell, C A; Stirtan, W; Withers, S G

    1993-01-01

    The catalytic role of the cofactor phosphate moiety at the active site of glycogen phosphorylase has been the subject of many investigations including solution-state high-resolution 31P-NMR studies. In this study the pyridoxal phosphate moiety in both the inactive and active forms of microcrystalline phosphorylase b has been investigated by high-resolution 31P magic-angle spinning NMR. The symmetry of the shielding tensor in model compounds at varying degrees of ionization is investigated and the results indicate a marked difference between the dianionic and monoanionic model compounds. Consequently the observed similarity in the principal tensor components describing the shielding tensor of the phosphorus nuclei present at the active site of both the R- and T-state conformations suggests that there is no change in ionization site upon activation in contrast to suggestions based upon isotropic shifts. Since previous relaxation measurements have pointed to the need to consider motional influences in such systems, several plausible models are considered. Subject to the assumption of congruency between the principal axis system describing the shielding interaction and molecular frame determined by the molecular symmetry axes, we conclude that the phosphate cofactor is dianionic in both forms. PMID:8457672

  13. The intact muscle lipid composition of bulls: an investigation by MALDI-TOF MS and 31P NMR.

    PubMed

    Dannenberger, Dirk; Süss, Rosmarie; Teuber, Kristin; Fuchs, Beate; Nuernberg, Karin; Schiller, Jürgen

    2010-02-01

    The analysis of beef lipids is normally based on chromatographic techniques and/or gas chromatography in combination with mass spectrometry (GC/MS). Modern techniques of soft-ionization MS were so far scarcely used to investigate the intact lipids in muscle tissues of beef. The objective of the study was to investigate whether matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) mass spectrometry and (31)P nuclear magnetic resonance (NMR) spectroscopy are useful tools to study the intact lipid composition of beef. For the MALDI-TOF MS and (31)P NMR investigations muscle samples were selected from a feeding experiment with German Simmental bulls fed different diets. Beside the triacylglycerols (TAGs), phosphatidylethanolamine (PE), phosphatidylcholine (PC) and phosphatidylinositol (PI) species the MALDI-TOF mass spectra of total muscle lipids gave also intense signals of cardiolipin (CL) species. The application of different matrix compounds, 2,5-dihydroxybenzoic acid (DHB) and 9-aminoacridine (9-AA), leads to completely different mass spectra: 9-AA is particularly useful for the detection of (polar) phospholipids, whereas apolar lipids, such as cholesterol and triacylglycerols, are exclusively detected if DHB is used. Finally, the quality of the negative ion mass spectra is much higher if 9-AA is used. PMID:19900429

  14. /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.

  15. 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

    2016-07-01

    (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. PMID:27117609

  16. Muscle phosphoglycerate mutase (PGAM) deficiency in the first Caucasian patient: biochemistry, muscle culture and 31P-MR spectroscopy.

    PubMed

    Vita, G; Toscano, A; Bresolin, N; Meola, G; Fortunato, F; Baradello, A; Barbiroli, B; Frassineti, C; Zaniol, P; Messina, C

    1994-03-01

    Muscle phosphoglycerate mutase (PGAM) deficiency has been so far identified in only six patients, five of these being African Americans. We report the results of clinical, morphological, biochemical, muscle culture and 31P-MR spectroscopy studies in the first Caucasian patient with muscle PGAM deficiency. A 23-year-old man had a 10-year history of cramps after physical exertion with one episode of pigmenturia. Neurological examination and EMG study were normal. ECG and echocardiography revealed hypertrophy of the interventricular septum and slight dilation of the left chambers of the heart. Muscle biopsy revealed increased glycogen content and some accumulation of mitochondria. Muscle PGAM activity was markedly decreased (6.5% and 9.7% of control value in two different biopsies). Citrate synthase and other mitochondrial respiratory chain enzyme activities were much higher than normal. In contrast to the marked decrease of PGAM activity observed in muscle biopsy, total enzyme activity in the patient's aneural muscle culture was normal, being represented exclusively by BB isoenzyme. The deficiency of PGAM-MM isoenzyme was reproduced in the patient's innervated muscle culture. Muscle 31P-MR spectroscopy showed accumulation of phosphomonoesters only on fast "glycolytic" exercise. On "aerobic" exercise, Vmax, calculated from the work-energy cost transfer function, showed an increase consistent with the morphological and biochemical evidence of mitochondrial proliferation. This might represent a sort of compensatory aerobic effort in an attempt to restore muscle power. PMID:8006681

  17. 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.

  18. FTIR and {sup 31}P-NMR spectroscopic analyses of surface species in phosphate-catalyzed lactic acid conversion

    SciTech Connect

    Gunter, G.C.; Tam, M.S.; Miller, D.J.

    1996-11-01

    The surface species present on silica/alumina-supported sodium phosphates, active catalysts for the conversion of lactic acid to acrylic acid and 2,3-pentanedione, are examined by pre- and postreaction MAS {sup 31}P-NMR and FTIR spectroscopies. Species present following lactic acid conversion are identified by transmission FTIR of phosphates supported on silicon disks (as a model catalyst system) and verified by {sup 31}P-NMR and diffuse reflectance IR spectroscopy of actual catalysts used in reaction. Monosodium phosphate (NaH{sub 2}PO{sub 4}) condenses to a mixture of sodium polyphosphate (NaPO{sub 3}){sub n} and sodium trimetaphosphate (Na{sub 3}P{sub 3}O{sub 9}), which exhibit little catalytic activity for converting lactic acid to desired products. Disodium phosphate (Na{sub 2}HPO{sub 4}) condenses to tetrasodium pyrophosphate (Na{sub 4}P{sub 2}O{sub 7}), and proton transfer from lactic acid to pyrophosphate results in the formation of sodium lactate. Trisodium phosphate (Na{sub 3}PO{sub 4}) accepts a proton from lactic acid to form sodium lactate and disodium phosphate, which condenses to pyrophosphate. The presence of pyrophosphate and sodium lactate on supported disodium and trisodium phosphates explains their similar catalytic properties; the larger quantity of sodium lactate present on trisodium phosphate leads to higher conversions at lower temperatures. 40 refs., 14 figs., 2 tabs.

  19. Lateralization effects of image-guided 31P magnetoresonance spectroscopic parameters in the frontal lobe of schizophrenics and healthy controls

    NASA Astrophysics Data System (ADS)

    Huebner, Gabriele; Volz, Hans-Peter; Riehemann, Stefan; Wenda, Berit; Roessger, Grit; Rzanny, Reinhard; Sauer, Heinrich

    1999-05-01

    Phosphorus-31 magnetic resonance spectroscopy (31P-MRS) has gained much interest in schizophrenia research in the last years since it allows the non-invasive measurement of high- energy phosphates and phospholipids in vivo. We investigated hemispherical differences of the concentrations of different phosphorus compounds in the frontal lobes. For this purpose, well defined volumes in the dorsolateral prefrontal cortex of 32 healthy controls and 51 schizophrenic patients were examined. Schizophrenic patients showed significant lateralization effects of phosphodiesters (PDE) and the intracellular pH-value. Differences in the lateralization of 31P-MRS parameters between patients and healthy volunteers were only detected for the pH-value. While healthy controls exhibit lower pH-values in the left frontal lobe (6.96), in schizophrenic patients we found lower pH-values in the right (6.89). Detailed examinations showed that this effect is mainly based on the subgroup of schizophrenics who received atypical neuroleptic medication.

  20. 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.

  1. 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.

  2. Time course of myocardial sodium accumulation after burn trauma: a (31)P- and (23)Na-NMR study.

    PubMed

    Sikes, P J; Zhao, P; Maass, D L; Horton, J W

    2001-12-01

    In this study, (23)Na- and (31)P- nuclear magnetic resonance (NMR) spectra were examined in perfused rat hearts harvested 1, 2, 4, and 24 h after 40% total body surface area burn trauma and lactated Ringer resuscitation, 4 ml. kg(-1). %(-1) burn. (23)Na-NMR spectroscopy monitored myocardial intracellular Na+ using the paramagnetic shift reagent thulium 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetra(methylenephosphonic acid). Left ventricular function, cardiac high-energy phosphates (ATP/PCr), and myocyte intracellular pH were studied by using (31)P NMR spectroscopy to examine the hypothesis that burn-mediated acidification of cardiomyocytes contributes to subsequent Na+ accumulation by this cell population. Intracellular Na+ accumulation was confirmed by sodium-binding benzofuran isophthalate loading and fluorescence spectroscopy in cardiomyocytes isolated 1, 2, 4, 8, 12, 18, and 24 h postburn. This myocyte Na+ accumulation as early as 2 h postburn occurred despite no changes in cardiac ATP/PCr and intracellular pH. Left ventricular function progressively decreased after burn trauma. Cardiomyocyte Na+ accumulation paralleled cardiac contractile dysfunction, suggesting that myocardial Na+ overload contributes, in part, to the progressive postburn decrease in ventricular performance. PMID:11717236

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

    PubMed

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

    2014-12-01

    During constant-power high-intensity exercise, the expected increase in oxygen uptake (V̇O2) is supplemented by a V̇O2 slow component (V̇O2 sc ), 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 (31)P magnetic resonance spectroscopy (MRS) and whole-body V̇O2 during moderate (MOD) and heavy (HVY) bilateral knee-extension exercise in healthy participants (n = 14). Unlocalized (31)P spectra were collected from the quadriceps throughout using a dual-tuned ((1)H and (31)P) 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 V̇O2 sc (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 V̇O2 sc 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 V̇O2 sc during HVY (r(2) = 0.06; P = n.s.). This lack of relationship between ΔATPtot and V̇O2 sc , together with a steepening of the [PCr]-V̇O2 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

  4. 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

  5. Kaon-nucleus scattering

    NASA Technical Reports Server (NTRS)

    Hong, Byungsik; Maung, Khin Maung; Wilson, John W.; Buck, Warren W.

    1989-01-01

    The derivations of the Lippmann-Schwinger equation and Watson multiple scattering are given. A simple optical potential is found to be the first term of that series. The number density distribution models of the nucleus, harmonic well, and Woods-Saxon are used without t-matrix taken from the scattering experiments. The parameterized two-body inputs, which are kaon-nucleon total cross sections, elastic slope parameters, and the ratio of the real to the imaginary part of the forward elastic scattering amplitude, are presented. The eikonal approximation was chosen as our solution method to estimate the total and absorptive cross sections for the kaon-nucleus scattering.

  6. Convergence of the nucleus-nucleus Glauber multiple scattering series

    SciTech Connect

    Usmani, A.A.; Ahmad, I. )

    1991-05-01

    The Glauber {ital S}-matrix operator for nucleus-nucleus scattering is expressed as a finite series of matrix elements involving Bell's polynomials. Analyzing {alpha}{sup 4}He elastic-scattering data at the incident momentum of 4.32 GeV/{ital c}, we infer that our expansion is appreciably converging. Further, by applying closure over target and projectile states and neglecting a certain class of terms involving intermediate excitations, we arrive at a recurrence relation for nucleus-nucleus multiple scattering series terms, which invites further study as it seems to provide a simple method for calculating the nucleus-nucleus elastic-scattering cross section.

  7. An efficient 1H/31P double-resonance solid-state NMR probe that utilizes a scroll coil

    PubMed Central

    Grant, Christopher V.; Sit, Siu-Ling; De Angelis, Anna A.; Khuong, Kelli S.; Wu, Chin H.; Plesniak, Leigh A.; Opella, Stanley J.

    2007-01-01

    The construction and performance of a scroll coil double-resonance probe for solid-state NMR on stationary samples is described. The advantages of the scroll coil at the high resonance frequencies of 1H and 31P include: high efficiency, minimal perturbations of tuning by a wide range of samples, minimal RF sample heating of high dielectric samples of biopolymers in aqueous solution, and excellent RF homogeneity. The incorporation of a cable tie cinch for mechanical stability of the scroll coil is described. Experimental results obtained on a Hunter Killer Peptide 1 (HKP1) interacting with phospholipid bilayers of varying lipid composition demonstrate the capabilities of this probe on lossy aqueous samples. PMID:17719813

  8. An efficient (1)H/(31)P double-resonance solid-state NMR probe that utilizes a scroll coil.

    PubMed

    Grant, Christopher V; Sit, Siu-Ling; De Angelis, Anna A; Khuong, Kelli S; Wu, Chin H; Plesniak, Leigh A; Opella, Stanley J

    2007-10-01

    The construction and performance of a scroll coil double-resonance probe for solid-state NMR on stationary samples is described. The advantages of the scroll coil at the high resonance frequencies of (1)H and (31)P include: high efficiency, minimal perturbations of tuning by a wide range of samples, minimal RF sample heating of high dielectric samples of biopolymers in aqueous solution, and excellent RF homogeneity. The incorporation of a cable tie cinch for mechanical stability of the scroll coil is described. Experimental results obtained on a Hunter Killer Peptide 1 (HKP1) interacting with phospholipid bilayers of varying lipid composition demonstrate the capabilities of this probe on lossy aqueous samples. PMID:17719813

  9. 31P NMR study of magnetic phase transitions of MnP single crystal under 2 GPa pressure

    NASA Astrophysics Data System (ADS)

    Fan, GuoZhi; Zhao, Bo; Wu, Wei; Zheng, Ping; Luo, JianLin

    2016-05-01

    Superconductivity on the border of the long-range magnetic order has been discovered in MnP under high pressures. In order to investigate the nature of the magnetic properties adjacent to the superconducting state, we performed zero-field 31P NMR for MnP single crystal under ambient and hydrostatic pressure of 2 GPa, respectively. Radio frequency power level was used to determine whether NMR signal originates from a helical state or not. When 2 GPa pressure was applied, the signal from helical state exists even above 160 K, while that from the ferromagnetic phase was not observed. Our NMR results indicate that the magnetic phase which is adjacent to the superconducting state is in a helical magnetic structure.

  10. 31P NMR study of daunorubicin-d(CGTACG) complex in solution. Evidence of the intercalation sites.

    PubMed

    Ragg, E; Mondelli, R; Battistini, C; Garbesi, A; Colonna, F P

    1988-08-15

    The interaction of daunorubicin with the self-complementary DNA fragment d(CGTACG) was studied by 31P NMR spectroscopy. The individual phosphates have been assigned for the nucleotide and the complex and signals from bound and free species in slow exchange at 19 degrees C were detected. In solution, the hexanucleotide binds two molecules of daunorubicin, which intercalate in the d(CG) sequence at both ends of the helix. Evidence for local deformations of the backbone at the sites of C5pG6, C1pG2 and G2pT3 phosphates is given. The binding constants for the stepwise equilibrium and the rate of dissociation of the intercalated duplex were also determined. PMID:3402614

  11. Analysis of 31P nuclear magnetic resonance lineshapes and transversal relaxation of bacteriophage M13 and tobacco mosaic virus.

    PubMed Central

    Magusin, P C; Hemminga, M A

    1993-01-01

    The experimentally observed 31P lineshapes and transversal relaxation of 15% (wt/wt) M13, 30% M13, and 30% tobacco mosaic virus (TMV) are compared with lineshapes and relaxation curves that are simulated for various types of rotational diffusion using the models discussed previously (Magusin, P. C. M. M., and M. A. Hemminga. 1993. Biophys. J. 64:1851-1860). It is found that isotropic diffusion cannot explain the observed lineshape effects. A rigid rod diffusion model is only successful in describing the experimental data obtained for 15% M13. For 30% M13 the experimental lineshape and relaxation curve cannot be interpreted consistently and the TMV lineshape cannot even be simulated alone, indicating that the rigid rod diffusion model does not generally apply. A combined diffusion model with fast isolated motions of the encapsulated nucleic acid dominating the lineshape and a slow overall rotation of the virion as a whole, which mainly is reflected in the transversal relaxation, is able to provide a consistent picture for the 15 and 30% M13 samples, but not for TMV. Strongly improved lineshape fits for TMV are obtained assuming that there are three binding sites with different mobilities. The presence of three binding sites is consistent with previous models of TMV. The best lineshapes are simulated for a combination of one mobile and two static sites. Although less markedly, the assumption that two fractions of DNA with different mobilities exist within M13 also improves the simulated lineshapes. The possible existence of two 31P fractions in M13 sheds new light on the nonintegral ratio 2.4:1 between the number of nucleotides and protein coat subunits in the phage: 83% of the viral DNA is less mobile, suggesting that the binding of the DNA molecule to the protein coat actually occurs at the integral ratio of two nucleotides per protein subunit. PMID:8369412

  12. 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.

  13. 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. PMID:26681323

  14. 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.

  15. /sup 31/P NMR probes of sipunculan erythrocytes containing the O/sub 2/-carying protein hemerythrin

    SciTech Connect

    Robitaille, P.M.L.; Kurtz, D.M. Jr

    1988-06-14

    Reported are the first examinations by /sup 31/P NMR of erythrocytes containing the non-heme iron O/sub 2/ carrying protein hemerythrin (Hr). Intact coelomic erythrocytes from the sipunculids Phascolopsis gouldii and Themiste zostericola were shown by /sup 31/P NMR to contain O-phosphorylethanolamine and 2-amino-ethylphosphonate as the major soluble phosphorus metabolites. This combination of major metabolites appears to be unique to sipunculan erythrocytes. Nucleoside triphosphates and mannose 1-phosphate were present in lower concentrations. The concentration of O-phosphorylethanolamine within P. gouldii erythrocytes was established to be > 20 mM. T. zostericola erythrocytes contained relatively high levels of 2-amino-ethylphosphonate and lower levels of O-phosphorylethanolamine compared with those of P. gouldii. For P. gouldii and T. zostericola the intracellular pHs were determined to be 7.2 +/- 0.1 and 7.1 +/- 0.1, respectively, in air-equilibrated erythrocytes, and 6.5 +/- 0.1 in anaerobic P. gouldii erythrocytes. O-Phosphorylethanolamine was found to bind weakly to P. gouldii metHr. This interaction is best characterized by either negative cooperativity or nonspecific binding. O-phosphorylethanolamine strongly inhibits azide binding to the iron site of P. gouldii metHr at pH 7.2. The rate of azide binding decreases by approx. 85-fold in the presence of 0.33 M O-phosphorylethanolamine. However, neither O-phosphorylethanolamine nor 2-aminoethylphosphonate at 0.33 M was found to have any significant effect on O/sub 2/ affinity of P. gouldii deoxyHr. Alternative functions for the two metabolites are suggested.

  16. Determination of neo- and D-chiro-inositol hexakisphosphate in soils by solution 31P NMR spectroscopy.

    PubMed

    Turner, Benjamin L; Cheesman, Alexander W; Godage, H Yasmin; Riley, Andrew M; Potter, Barry V L

    2012-05-01

    The inositol phosphates are an abundant but poorly understood group of organic phosphorus compounds found widely in the environment. Four stereoisomers of inositol hexakisphosphate (IP(6)) 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-IP(6) and used them to identify signals from these compounds in three soils from the Falkland Islands. Both compounds resisted hypobromite oxidation and gave quantifiable (31)P NMR signals at δ = 6.67 ppm (equatorial phosphate groups of the 4-equatorial/2-axial conformer of neo-IP(6)) and δ = 6.48 ppm (equatorial phosphate groups of the 2-equatorial/4-axial conformer of D-chiro-IP(6)) 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-IP(6) 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-IP(6) in the environment. The hypobromite oxidation and solution (31)P NMR spectroscopy procedure allows the simultaneous quantification of all four IP(6) stereoisomers in environmental samples and provides a platform for research into the origins and ecological significance of these enigmatic compounds. PMID:22489788

  17. Nucleus Course in Japanese.

    ERIC Educational Resources Information Center

    Akiyama, Nobuo; Flamm, Carol S.

    The "Nucleus Course in Japanese," based on the Institute of Modern Languages'"Situational Reinforcement" approach, is designed for 80 to 100 hours of instruction. Each lesson has several sections--Response drills, Appropriate Response Sequence, and Reading. Most of the lessons also include optional sections with Sentences for Repetition or a…

  18. Cell nucleus in context

    SciTech Connect

    Lelievre, Sophie A.; Bissell, Mina J.; Pujuguet, Philippe

    1999-11-11

    The molecular pathways that participate in regulation of gene expression are being progressively unraveled. Extracellular signals, including the binding of extracellular matrix and soluble molecules to cell membrane receptors, activate specific signal transducers that convey information inside the cell and can alter gene products. Some of these transducers when translocated to the cell nucleus may bind to transcription complexes and thereby modify the transcriptional activity of specific genes. However, the basic molecules involved in the regulation of gene expression are found in many different cell and tissue types; thus the mechanisms underlying tissue-specific gene expression are still obscure. In this review, we focus on the study of signals that are conveyed to the nucleus. We propose that the way in which extracellular signals are integrated may account for tissue-specific gene expression. We argue that the integration of signals depends on the structural organization of cells ( i.e., extracellular matrix, cell membrane, cytoskeleton, nucleus) which a particular cell type within a tissue. Putting the nuclei in context allows us to envision gene expression as being regulated not only by the communication between the extracellular environment and the nucleus, but also by the influence of organized assemblies of cells on extracellular-nuclear communications.

  19. Pyridoxal phosphate binding sites are similar in human heme-dependent and yeast heme-independent cystathionine beta-synthases. Evidence from 31P NMR and pulsed EPR spectroscopy that heme and PLP cofactors are not proximal in the human enzyme.

    PubMed

    Kabil, O; Toaka, S; LoBrutto, R; Shoemaker, R; Banerjee, R

    2001-06-01

    Two classes of cystathionine beta-synthases have been identified in eukaryotes, the heme-independent enzyme found in yeast and the heme-dependent form found in mammals. Both classes of enzymes catalyze a pyridoxal phosphate (PLP)-dependent condensation of serine and homocysteine to produce cystathionine. The role of the heme in the human enzyme and its location relative to the PLP in the active site are unknown. (31)P NMR spectroscopy revealed that spin-lattice relaxation rates of the phosphorus nucleus in PLP are similar in both the paramagnetic ferric (T(1) = 6.34 +/- 0.01 s) and the diamagnetic ferrous (T(1) = 5.04 +/- 0.06 s) enzyme, suggesting that the two cofactors are not proximal to each other. This is also supported by pulsed EPR studies that do not provide any evidence for strong or weak coupling between the phosphorus nucleus and the ferric iron. However, the (31)P signal in the reduced enzyme moved from 5.4 to 2.2 ppm, and the line width decreased from 73 to 16 Hz, providing the first structural evidence for transmission to the active site of an oxidation state change in the heme pocket. These results are consistent with a regulatory role for the heme as suggested by previous biochemical studies from our laboratory. The (31)P chemical shifts of the resting forms of the yeast and human enzymes are similar, suggesting that despite the difference in their heme content, the microenvironment of the PLP is similar in the two enzymes. The addition of the substrate, serine, resulted in an upfield shift of the phosphorus resonance in both enzymes, signaling formation of reaction intermediates. The resting enzyme spectra were recovered following addition of excess homocysteine, indicating that both enzymes retained catalytic activity during the course of the NMR experiment. PMID:11278994

  20. Onset of deconfinement in nucleus-nucleus collisions

    SciTech Connect

    Gazdzicki, M.; Gorenstein, M. I.; Seyboth, P.

    2012-05-15

    The energy dependence of hadron production in relativistic nucleus-nucleus collisions reveals anomalies-the kink, horn, and step. They were predicted as signals of the deconfinement phase transition and observed by the NA49 Collaboration in central PbPb collisions at the CERN SPS. This indicates the onset of the deconfinement in nucleus-nucleus collisions at about 30 A GeV.

  1. Dynamic interleaved 1H/31P STEAM MRS at 3 Tesla using a pneumatic force-controlled plantar flexion exercise rig

    PubMed Central

    Meyerspeer, M.; Krššák, M.; Kemp, G.J.; Roden, M.; Moser, E.

    2016-01-01

    1 Objective To develop a measurement method for interleaved acquisition of 1H and 31P STEAM localised spectra of exercising human calf muscle. 2 Materials and Methods A nonmagnetic exercise rig with a pneumatic piston and sensors for force and pedal angle was constructed to enable plantar flexion measured in the 3 Tesla MR scanner, which holds the dual tuned (1H,31P) surface coil used for signal transmission and reception. 3 Results 31P spectra acquired in interleaved mode benefit from higher SNR (factor of 1.34± 0.06 for PCr) compared to standard acquisition due to the Nuclear Overhauser effect (NOE) and substantial PCr/Pi changes during exercise can be observed in 31P spectra. 1H spectral quality is equal to that in single mode experiments and allows Cr2 changes to be monitored. 4 Conclusion The feasibility of dynamic interleaved localised 1H and 31P spectroscopy during plantar flexion exercise has been demonstrated using a custom-built pneumatic system for muscle activation. This opens the possibility of studying the dynamics of metabolism with multi nuclear MRS in a single run. PMID:16320091

  2. Evaluation of recombinant CXCL8(3-73)K11R/G31P in muscle fibrosis and Trichinella larvae encapsulation in a murine model of trichinellosis.

    PubMed

    Yan, Wenhui; Li, Fang; Qin, Yuanhua; Ren, Yixin; Zheng, Lili; Dai, Xiaodong; Mao, Weifeng; Cui, Yu

    2016-06-01

    Trichinella spiralis (T. spiralis) larvae in raw or inadequately cooked meat can cause chronic infections in a wide range of hosts including humans. During the development inside the skeletal muscles, T. spiralis larvae infect muscle cells accompanying with the infiltration of host inflammatory cells, eventually create a new type of cell known as nurse cell developing a surrounding vascular network to support the larvae development. Controlling of host inflammatory responses and angiogenesis influences both the nurse cell differentiation and the parasite larvae development. CXCL8 is a chemokine that acts on G-protein coupled receptors, of which activation contributes to fibrosis and angiogenesis. CXCL8(3-73)K11R/G31P (G31P) has been reported as a CXCL8 analogue. The aim of this study is to investigate the effect of G31P in inflammatory responses and the development of T. spiralis larvae in muscle tissues of mice infected with T. spiralis. The level of inflammatory factors and the morphology of T. spiralis larvae in infected tissues were investigated through ELISA and electron-microscopy analysis. G31P up-regulated IFN-γ and down-regulated CXCL8 level, and impaired the encapsulation of T. spiralis larvae in vivo. The results showed that G31P influenced the development of T. spiralis larvae in muscle tissues. PMID:27089392

  3. Proton Nucleus Elastic Scattering Data.

    Energy Science and Technology Software Center (ESTSC)

    1993-08-18

    Version 00 The Proton Nucleus Elastic Scattering Data file PNESD contains the numerical data and the related bibliography for the differential elastic cross sections, polarization and integral nonelastic cross sections for elastic proton-nucleus scattering.

  4. The effects of pregnancy and parturition on phosphorus metabolites in rat uterus studied by 31P nuclear magnetic resonance.

    PubMed Central

    Dawson, M J; Wray, S

    1985-01-01

    Concentrations of phosphorus metabolites and intracellular pH have been measured in non-pregnant, late-pregnant and post-partum rat uterus using 31P nuclear magnetic resonance (31P n.m.r.). Intact uterine tissue was superfused with oxygenated de-Jalon solution at 4, 20 or 37 degrees C while inside the n.m.r. spectrometer. The phosphocreatine concentration [PCr], was higher and the inorganic phosphate concentration [Pi], lower than values determined by chemical analysis of extracts from both pregnant and non-pregnant rat uterus. [PCr] was 1.4-fold greater in late-pregnant than in non-pregnant rat uterus. Following parturition, large changes were observed in [PCr], [Pi] and in an unidentified metabolite in the phosphomonoester (PME) region of the n.m.r. spectrum. The time course of the recovery of these metabolites to prepregnant values was determined. The [PCr] remained below the non-pregnant value for at least 1 week post-partum and the [Pi] was elevated, compared to the non-pregnant value, during this period. More rapid changes were seen in the [PME], which doubled on day 0 post-partum but almost returned to its non-pregnant value on day 1 post-partum. No significant difference was observed between intracellular pH values in late-pregnant and non-pregnant rat uterus; however, there was a large acid shift following parturition. Intracellular pH depended upon the temperature at which the tissue was maintained. The effect of muscular work during parturition was investigated by comparing Caesarian-sectioned uteri with uteri which had undergone normal parturition. Uteri examined 1 day after Caesarian operation showed no differences in metabolite levels from normal, 1 day post-partum uteri. We conclude that concentrations of phosphorus metabolites depend upon the physiological state of the uterus. We suggest that the changes following parturition are not a consequence of the mechanical work performed by the uterus, but must be caused by some other event associated with

  5. Rotation of Lipids in Membranes: Molecular Dynamics Simulation, 31P Spin-Lattice Relaxation, and Rigid-Body Dynamics

    PubMed Central

    Klauda, Jeffery B.; Roberts, Mary F.; Redfield, Alfred G.; Brooks, Bernard R.; Pastor, Richard W.

    2008-01-01

    Molecular dynamics simulations and 31P-NMR spin-lattice (\\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}R_{1}\\end{equation*}\\end{document}) relaxation rates from 0.022 to 21.1 T of fluid phase dipalmitoylphosphatidylcholine bilayers are compared. Agreement between experiment and direct prediction from simulation indicates that the dominant slow relaxation (correlation) times of the dipolar and chemical shift anisotropy spin-lattice relaxation are ∼10 ns and 3 ns, respectively. Overall reorientation of the lipid body, consisting of the phosphorus, glycerol, and acyl chains, is well described within a rigid-body model. Wobble, with \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}D_{{\\bot}}=\\end{equation*}\\end{document} 1–2 × 108 s−1, is the primary component of the 10 ns relaxation; this timescale is consistent with the tumbling of a lipid-sized cylinder in a medium with the viscosity of liquid hexadecane. The value for \\documentclass[10pt]{article} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{pmc} \\usepackage[Euler]{upgreek} \\pagestyle{empty} \\oddsidemargin -1.0in \\begin{document} \\begin{equation*}D_{{\\Vert}},\\end{equation*}\\end{document} the diffusion constant for rotation about the long axis of the lipid body, is difficult to determine precisely because of averaging by fast motions and wobble; it is tentatively estimated to be 1 × 107 s−1. The resulting D‖/D⊥

  6. Interactions of ciprofloxacin with DPPC and DPPG: fluorescence anisotropy, ATR-FTIR and 31P NMR spectroscopies and conformational analysis.

    PubMed

    Bensikaddour, Hayet; Snoussi, Karim; Lins, Laurence; Van Bambeke, Françoise; Tulkens, Paul M; Brasseur, Robert; Goormaghtigh, Erik; Mingeot-Leclercq, Marie-Paule

    2008-11-01

    The interactions between a drug and lipids may be critical for the pharmacological activity. We previously showed that the ability of a fluoroquinolone antibiotic, ciprofloxacin, to induce disorder and modify the orientation of the acyl chains is related to its propensity to be expelled from a monolayer upon compression [1]. Here, we compared the binding of ciprofloxacin on DPPC and DPPG liposomes (or mixtures of phospholipids [DOPC:DPPC], and [DOPC:DPPG]) using quasi-elastic light scattering and steady-state fluorescence anisotropy. We also investigated ciprofloxacin effects on the transition temperature (T(m)) of lipids and on the mobility of phosphate head groups using Attenuated Total Reflection Fourier Transform Infrared-Red Spectroscopy (ATR-FTIR) and (31)P Nuclear Magnetic Resonance (NMR) respectively. In the presence of ciprofloxacin we observed a dose-dependent increase of the size of the DPPG liposomes whereas no effect was evidenced for DPPC liposomes. The binding constants K(app) were in the order of 10(5) M(-1) and the affinity appeared dependent on the negative charge of liposomes: DPPG>DOPC:DPPG (1:1; M:M)>DPPC>DOPC:DPPC (1:1; M:M). As compared to the control samples, the chemical shift anisotropy (Deltasigma) values determined by (31)P NMR showed an increase of 5 and 9 ppm for DPPC:CIP (1:1; M:M) and DPPG:CIP (1:1; M:M) respectively. ATR-FTIR experiments showed that ciprofloxacin had no effect on the T(m) of DPPC but increased the order of the acyl chains both below and above this temperature. In contrast, with DPPG, ciprofloxacin induced a marked broadening effect on the transition with a decrease of the acyl chain order below its T(m) and an increase above this temperature. Altogether with the results from the conformational analysis, these data demonstrated that the interactions of ciprofloxacin with lipids depend markedly on the nature of their phosphate head groups and that ciprofloxacin interacts preferentially with anionic lipid compounds

  7. Mapping hypoxia-induced bioenergetic rearrangements and metabolic signaling by 18O-assisted 31P NMR and 1H NMR spectroscopy.

    PubMed

    Pucar, Darko; Dzeja, Petras P; Bast, Peter; Gumina, Richard J; Drahl, Carmen; Lim, Lynette; Juranic, Nenad; Macura, Slobodan; Terzic, Andre

    2004-01-01

    Brief hypoxia or ischemia perturbs energy metabolism inducing paradoxically a stress-tolerant state, yet metabolic signals that trigger cytoprotection remain poorly understood. To evaluate bioenergetic rearrangements, control and hypoxic hearts were analyzed with 18O-assisted 31P NMR and 1H NMR spectroscopy. The 18O-induced isotope shift in the 31P NMR spectrum of CrP, betaADP and betaATP was used to quantify phosphotransfer fluxes through creatine kinase and adenylate kinase. This analysis was supplemented with determination of energetically relevant metabolites in the phosphomonoester (PME) region of 31P NMR spectra, and in both aromatic and aliphatic regions of 1H NMR spectra. In control conditions, creatine kinase was the major phosphotransfer pathway processing high-energy phosphoryls between sites of ATP consumption and ATP production. In hypoxia, creatine kinase flux was dramatically reduced with a compensatory increase in adenylate kinase flux, which supported heart energetics by regenerating and transferring beta- and gamma-phosphoryls of ATP. Activation of adenylate kinase led to a build-up of AMP, IMP and adenosine, molecules involved in cardioprotective signaling. 31P and 1H NMR spectral analysis further revealed NADH and H+ scavenging by alpha-glycerophosphate dehydrogenase (alphaGPDH) and lactate dehydrogenase contributing to maintained glycolysis under hypoxia. Hypoxia-induced accumulation of alpha-glycerophosphate and nucleoside 5'-monophosphates, through alphaGPDH and adenylate kinase reactions, respectively, was mapped within the increased PME signal in the 31P NMR spectrum. Thus, 18O-assisted 31P NMR combined with 1H NMR provide a powerful approach in capturing rearrangements in cardiac bioenergetics, and associated metabolic signaling that underlie the cardiac adaptive response to stress. PMID:14977188

  8. 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

  9. (31)P Solid-State NMR study of the chemical setting process of a dual-paste injectable brushite cements.

    PubMed

    Legrand, A P; Sfihi, H; Lequeux, N; Lemaître, J

    2009-10-01

    The composition and evolution of a brushite-type calcium phosphate cement was investigated by Solid-State NMR and X-ray during the setting process. The cement is obtained by mixing beta-tricalcium phosphate [Ca(3)(PO(4))(2), beta-TCP] and monocalcium phosphate monohydrate [Ca(H(2)PO(4))(2).H(2)O, MCPM] in presence of water, with formation of dicalcium phosphate dihydrate or brushite [CaHPO(2).2H(2)O, DCPD]. Analysis of the initial beta-TCP paste has shown the presence of beta-calcium pyrophosphate [Ca(2)P(2)O(7), beta-CPy] and that of the initial MCPM a mixture of MCPM and dicalcium phosphate [CaHPO(4), DCP]. Follow-up of the chemical composition by (31)P Solid-State NMR enables to show that the chemical setting process appeared to reach an end after 20 min. The constant composition observed at the end of the process was similarly determined. PMID:19365821

  10. Metabolic responses to forced dives in Pekin duck measured by indirect calorimetry and 31P-MRS.

    PubMed

    Stephenson, R; Jones, D R

    1992-12-01

    We tested the hypothesis that forced-dived ducks experience a reduction in metabolic rate during prolonged submergence. Unidirectionally ventilated conscious ducks were subjected to forced dives by temporarily stopping the airflow in the ventilation system and simultaneously filling a face mask with cold water. A typical cardiovascular response to submergence was observed: bradycardia and maintained arterial blood pressure. Phosphorylated metabolite concentrations in the pectoral muscle were measured noninvasively by phosphorus magnetic resonance spectroscopy (31P-MRS). ATP content was constant, and phosphocreatine was depleted via the creatine kinase reaction at a rate similar to the resting rate of ATP turnover, which was estimated to be 0.9 mumol.min-1 x g-1 in resting perfused pectoral muscle of pentobarbital-anesthetized ducks. Oxygen from myoglobin supplied at most 12% of the ATP required by the resting muscle during dives. Whole animal postdive excess oxygen consumption and blood lactic acid accumulation suggested that the shortfall in aerobic metabolism during forced dives was compensated by an increase in anaerobic metabolism. PMID:1481944

  11. 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

  12. In vivo /sup 31/P NMR studies of corn root tissue and its uptake of toxic metals. [Zea mays L

    SciTech Connect

    Pfeffer, P.E.; Tu, S.I.; Gerasimowicz, W.V.; Cavanaugh, J.R.

    1986-01-01

    Excised corn root tissue has been evaluated for its viability, integrity of compartmentation, intracellular pH gradients, total mobile phosphorus content and nucleotide concentrations under different levels of acidity, and mineral stresses using in vivo /sup 31/P nuclear magnetic resonance spectroscopy at 21 to 23/sup 0/C. Perfusion with Al/sup 3 +/ ion at low pH (4.0) for 20 hours caused the overall concentration of nucleotides in the cytoplasm to decrease significantly relative to the control. Respiratory activity as measured by O/sub 2/ uptake decreased by a comparable amount over this time period. The addition of glucose to the Al-containing perfusate negated the inhibitory effects on the respiratory system. Treatment of the tissue with paramagnetic manganese ion while perfusing in the presence of O/sub 2/ allowed for the observation of the sequence of events leading to the irreversible trapping of Mn/sup 2 +/ in the vacuole. Pretreatment of the roots with Mg/sup 2 +/ prevented Mn/sup 2 +/ migration to the vacuole over the time period of this experiment. Hypoxia prevented all but a limited uptake of Mn/sup 2 +/ into the cytoplasm of the root tips. No evidence of Mn/sup 2 +/ complexation of either cytoplasmic or vacuole Pi suggests that the energy derived from O/sub 2/ consuming processes is necessary for the facilitated movement of this divalent cation.

  13. Centerband-only analysis of rotor-unsynchronized spin echo for measurement of lipid (31) P chemical shift anisotropy.

    PubMed

    Umegawa, Yuichi; Yamaguchi, Toshiyuki; Murata, Michio; Matsuoka, Shigeru

    2015-07-01

    Structural diversity and molecular flexibility of phospholipids are essential for biological membranes to play key roles in numerous cellular processes. Uncovering the behavior of individual lipids in membrane dynamics is crucial for understanding the molecular mechanisms underlying biological functions of cell membranes. In this paper, we introduce a simple method to investigate dynamics of lipid molecules in multi-component systems by measuring the (31) P chemical shift anisotropy (CSA) under magic angle spinning (MAS) conditions. For achieving both signal separation and CSA determination, we utilized a centerband-only analysis of rotor-unsynchronized spin echo (COARSE). This analysis is based on the curve fitting of periodic modulation of centerband intensity along the interpulse delay time in rotor-unsynchronized spin-echo experiments. The utility of COARSE was examined by using phospholipid vesicles, a three-component lipid raft model system, and archaeal purple membranes. We found that the apparent advantages of this method are high resolution and high sensitivity given by the moderate MAS speed and the one-dimensional acquisition with short spin-echo delays. COARSE provides an alternative method for CSA measurement that is effective in the investigation of lipid polymorphologies. PMID:26017552

  14. 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.

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

    PubMed

    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

    (31)P 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

  16. 13C/31P NMR studies on the role of glucose transport/phosphorylation in human glycogen supercompensation.

    PubMed

    Price, T B; Laurent, D; Petersen, K F

    2003-05-01

    This study measured muscle glycogen during a 7-day carbohydrate loading protocol. Twenty healthy subjects (12 male, 8 female) performed 1 hr treadmill/toe-raise exercise immediately before a 3-day low carbohydrate (LoCHO) diet (20 % carbohydrate, 60 % fat, 20 % protein). On day 3 they repeated the exercise and began a 4-day high carbohydrate (HiCHO) diet (90 % carbohydrate, 2 % fat, 8 % protein). The order of administration of the diet was reversed in a subpopulation (n = 3). Interleaved natural abundance 13C/ 31P NMR spectra were obtained before and immediately after exercise, and each day during the controlled diets in order to determine concentrations of glycogen (GLY), glucose-6-phosphate (G6P), and muscle pH. Following exercise, muscle GLY and pH were reduced (p < 0.001) while muscle G6P was elevated (p

  17. Effects of chloramphenicol on brain energy metabolism using 31P spectroscopy: influences on sleep-wake states in rat.

    PubMed

    Chahboune, Halima; Mahdjoub, Rachid; Desgoutte, Pierre; Rousset, Colette; Briguet, André; Cespuglio, Raymond

    2008-08-01

    Effects of chloramphenicol (antibiotic inhibiting complex-1 of respiratory chain) and thioamphenicol (TAP, a structural analog of CAP inactive on complex-1) were examined on cerebral energy metabolites and sleep-wake cycle architecture in rat. In the first group, animals were chronically equipped with a cranial surface resonator and (31)P spectroscopic measurements were performed using a 2 T magnetic resonance spectrometer (operating frequency 34.46 MHz). CAP administration (400 mg/kg, tail vein, light period) induced deficits in phosphocreatine (-30%, p < 0.01) and ATP (-40%, p < 0.01), whereas TAP (400 mg/kg) had no effect. In the second group, animals were chronically implanted with polygraphic electrodes for EEG and electromyogram recordings. CAP administered intraperitoneally at light-onset reduced rapid-eye movement (REM) sleep (-60% in the first 6 h of light period, p < 0.01), increased waking state (+65% in the first 6 h of light period, p < 0.01), and slightly affected slow-wave sleep (SWS). During waking state, theta and sigma power bands of the EEG were, respectively, increased and decreased (p < 0.05). During SWS, delta power band was reinforced (p < 0.05), while theta, alpha, and sigma bands were decreased (p < 0.05). No changes occurred during REM sleep. TAP had no effect on sleep-wake states and spectral components of the EEG. Overall, these data indicate that REM sleep occurrence is linked to an aerobic production of ATP. PMID:18507739

  18. Modulation of 2,3-diphosphoglycerate 31P-NMR resonance positions by red cell membrane shape.

    PubMed

    Fossel, E T; Solomon, A K

    1976-06-17

    Na+ transport in the red cells of the dog is dependent on cell volume, a 20% change in cell volume leading to a 25-fold increase in apparent Na+ flux; the effect is dependent upon metabolic energy. We have found that swelling and shrinking dog red cells causes a shift in the 31P-NMR peak of 2,3-diphosphoglycerate, which is present in dog red cells at 5.5 mM. Control experiments indicate that the 2,3-diphosphoglycerate resonance peak shifts may not be attributed to: interaction with hemoglobin, changes in cell pH, ionic strength, diamagnetic susceptibility or small changes in the Mg2+/2,3-diphosphoglycerate ratio. Experiments with chlorpromazine and pentanol which alter red cell membrane area by a mechanism different from osmotic swelling suggest that 2,3-diphosphoglycerate interacts with a binding site in the cell that is dependent upon the physical condition of the dog red cell membrane. PMID:1276226

  19. 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. PMID:22953921

  20. Analytic optical potentials for nucleon-nucleus nucleus-nucleus collisions involving light and medium nuclei

    NASA Technical Reports Server (NTRS)

    Bidasaria, H. B.; Townsend, L. W.

    1982-01-01

    Utilizing an optical model potential approximation to the exact nucleus-nucleus multiple-scattering series, optical potentials for nucleon-nucleus and nucleus-nucleus collisions are analytically derived. These expressions are applicable to light and medium cosmic ray nuclei as their single-particle density distributions are analytically determined, without approximation, from their actual harmonic well charge density distributions. Pauli correlation effects are included through the use of a simple Gaussian function to replace the usual expression obtained in the infinite nuclear matter approximation.

  1. Neutrino-nucleus interactions

    SciTech Connect

    Gallagher, H.; Garvey, G.; Zeller, G.P.; /Fermilab

    2011-01-01

    The study of neutrino oscillations has necessitated a new generation of neutrino experiments that are exploring neutrino-nuclear scattering processes. We focus in particular on charged-current quasi-elastic scattering, a particularly important channel that has been extensively investigated both in the bubble-chamber era and by current experiments. Recent results have led to theoretical reexamination of this process. We review the standard picture of quasi-elastic scattering as developed in electron scattering, review and discuss experimental results, and discuss additional nuclear effects such as exchange currents and short-range correlations that may play a significant role in neutrino-nucleus scattering.

  2. Nucleus from string theory

    NASA Astrophysics Data System (ADS)

    Hashimoto, Koji; Morita, Takeshi

    2011-08-01

    In generic holographic QCD, we find that baryons are bound to form a nucleus, and that its radius obeys the empirically-known mass-number (A) dependence r∝A1/3 for large A. Our result is robust, since we use only a generic property of D-brane actions in string theory. We also show that nucleons are bound completely in a finite volume. Furthermore, employing a concrete holographic model (derived by Hashimoto, Iizuka, and Yi, describing a multibaryon system in the Sakai-Sugimoto model), the nuclear radius is evaluated as O(1)×A1/3[fm], which is consistent with experiments.

  3. 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.

  4. 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.

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

    PubMed

    Koskela, Harri; Hakala, Ullastiina; Vanninen, Paula

    2010-06-15

    Decontamination solutions, which are usually composed of strong alkaline chemicals, are used for efficient detoxification of chemical warfare agents (CWAs). The analysis of CWA degradation products directly in decontamination solutions is challenging due to the nature of the matrix. Furthermore, occasionally an unforeseen degradation pathway can result in degradation products which could be eluded to in standard analyses. Here, we present the results of the application of proton band-selective (1)H-(31)P NMR spectroscopy, i.e., band-selective 1D (1)H-(31)P heteronuclear single quantum coherence (HSQC) and band-selective 2D (1)H-(31)P HSQC-total correlation spectroscopy (TOCSY), for ester side chain characterization of organophosphorus nerve agent degradation products in decontamination solutions. The viability of the approach is demonstrated with a test mixture of typical degradation products of nerve agents sarin, soman, and VX. The proton band-selective (1)H-(31)P NMR spectroscopy is also applied in characterization of unusual degradation products of VX in GDS 2000 solution. PMID:20507069

  7. 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

  8. sup 31 P NMR saturation-transfer study of the in situ kinetics of the mitochondrial adenine nucleotide translocase

    SciTech Connect

    Masiakos, P.T.; Williams, G.D.; Berkich, D.A.; Smith, M.B.; LaNoue, K.F. )

    1991-08-27

    The exchange of intramitochondrial ATP (ATP{sub in}) for extramitochondrial ATP (ATP{sub out}) was measured by using {sup 31}P NMR spectroscopy over a range of temperatures in isolated rat liver mitochondria oxidizing glutamate and succinate in the presence of external ATP but no added ADP (state 4). The rate of this exchange is more than an order of magnitude faster than rates reported previously that were determined by using isotopic techniques in the presence of oligomycin, the potent ATPase inhibitor. Differences are ascribed in part to the low levels of matrix ATP present in oligomycin-treated mitochondrial. Intramitochondrial ATP content regulates the rate of the ATP{sub in}/ATP{sub out} exchange. At 18C, the concentration of internal ATP that produces half-maximal transport rate is 6.6{plus minus}0.12 nmol/mg of mitochondrial protein. The relationship between substrate concentration and flux is sigmoidal and is 90% saturated at 11.3{plus minus}0.18 nmol/mg of mitochondrial protein. Since the measured rates of exchange of ATP{sub in} for ATP{sub out} are almost 10 times faster than the ATP synthase (ATP/P{sub i}) exchange rates, the translocase cannot limit net ATP/P{sub i} exchange in state 4. It may, nonetheless, limit net synthesis of ATP under other conditions when matrix ATP concentration is lower than in state 4 and when external ADP is present at higher concentrations than in these experiments.

  9. Decreased energy requirement of toad retina during light adaptation as demonstrated by 31P nuclear magnetic resonance.

    PubMed Central

    Apte, D V; Ebrey, T G; Dawson, M J

    1993-01-01

    1. The effect of light and dark adaptation on the levels of phosphorus metabolites (nucleotide di- and triphosphates, phosphocreatine, pyridine nucleotide, inorganic phosphate, phosphodiesters, phosphomonoesters, and uridine diphosphate-glucose) in the toad (Bufo marinus) retina and retinal extracts was studied by 31P nuclear magnetic resonance (NMR) spectroscopy. 2. Spectra were acquired using an NMR probe specifically designed for superfusion and illumination of a single retina. Retinae were maintained at a steady state for up to 10 h in an electrolyte solution containing 10 mM Hepes buffer and bubbled with 98% O2-2% CO2, pH 7.8 at 20 degrees C. 3. The intracellular concentrations of the phosphorus metabolites were measured in total darkness or during prolonged exposure to light. The concentration of nucleoside triphosphates (NTP) in the dark-adapted retina was about 1.5 mM and that of phosphocreatine (PCr) was about 0.7 mM. 4. In saturating levels of light, 6.0 x 10(11) or 1.5 x 10(13) quanta s-1 cm-2 at 520 nm, the levels of PCr and phosphomonoesters rose, the levels of NTP and protons (pH) were maintained, and the levels of pyridine nucleotides and nucleotide diphosphates (NDP) fell. 5. A rise in the level of PCr in the presence of an unchanged level of NTP in the light-adapted retina indicates that the energy consumption of the retina is greater in the dark. 6. These results are in agreement with the results of oxygen consumption, glucose dependence, and electrophysiological studies which also indicate that the metabolic energy requirement of the retina decreases in light. PMID:8229802

  10. 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.

  11. 31P nuclear magnetic resonance studies of the association of basic proteins with multilayers of diacyl phosphatidylserine.

    PubMed

    Smith, R; Cornell, B A; Keniry, M A; Separovic, F

    1983-08-10

    Lysozyme, cytochrome c, poly(L-lysine), myelin basic protein and ribonuclease were used to form multilayer dispersions containing about 50% protein (by weight) with bovine brain diacyl phosphatidylserine (PS). 31P nuclear magnetic resonance shift anisotropies, spin-spin (T2) and spin-lattice (T1) relaxation times for the lipid headgroup phosphorus were measured at 36.44 MHz. At pH 7.5, lysozyme, cytochrome c, poly(L-lysine) and ribonuclease were shown to increase the chemical shift anisotropy of PS by between 12-20%. Myelin basic protein altered the shape of the phosphate resonance, suggesting the presence of two lipid components, one of which had a modified headgroup conformation. The presence of cytochrome c led to the formation of a narrow spike at the isotropic shift position of the spectrum. Of the various proteins or peptides we have studied, only poly(L-lysine) and cytochrome c had any effect on the T1 of PS (1050 ms). Both caused a 20-30% decrease in T1 of the lamellar-phase phosphate peak. The narrow peak in the presence of cytochrome c had a very short T1 of 156 ms. The possibility is considered that the cytochrome Fe3+ contributes to the phosphate relaxation in this case. The effect of all proteins on the T2 of the phosphorus resonance was to cause an increase from the value for pure PS (1.6 ms) to between 2 and 5 ms. The results obtained with proteins are compared with the effects of small ions and intrinsic membrane proteins on the order and motion of the headgroups of lipids in bilayers. PMID:6191774

  12. 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

  13. 31P-NMR analysis of congestive heart failure in the SHHF/Mcc-facp rat heart.

    PubMed

    Michael O'Donnell, J; Narayan, P; Bailey, M Q; Abduljalil, A M; Altschuld, R A; McCune, S A; Robitaille, P M

    1998-02-01

    31P-NMR was used to monitor myocardial bioenergetics in compensated and failing SHHF/MCC-fa(cp) (SHF) rat hearts. The SHHF/Mcc-fa(cp) (spontaneous hypertension and heart failure) rat is a relatively new genetic model in which all individuals spontaneously develop congestive heart failure, most during the second year of life. Failing SHF rat hearts displayed a pronounced decrease in resting PCr:ATP ratios (P<0.001), which was explained by a significant (P<0. 0001) drop in total creatine (47.2+/-3.1 nmol/mg protein) v age matched controls (106+/-3 nmol/mg protein). In end stage failure, NMR determined PCr was 2.9+/-0.1 micro mol/g wet weight under basal conditions. In contrast, 6- and 20-month-old controls and compensated SHFs had PCr values of 5.3+/-0.1, and 5.1+/-0.5 and 5. 1+/-0.2 micro mol/g wet weight. Both compensated and failing SHF hearts were metabolically compromised when the rate pressure product (RPP) was increased, as evidenced by an increase in Pi and a drop in PCr. Compensated SHF hearts, however, were able to increase rate pressure products (RRP, mmHg X beats/min) from 44.5+/-1.4 to 66.6+/-3. 4 K with dobutamine infusion, whereas hearts in end-stage failure were able to increase their RPP from baseline values of 27+/-4 K to only 37+/-7 K. The data indicate that a pronounced decline in PCr and total creatine signals the transition from compensatory hypertrophy to decompensation and failure in the SHF rat model of hypertensive cardiomyopathy. PMID:9515000

  14. 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.

  15. Mitochondrial NAD(P)H In vivo: Identifying Natural Indicators of Oxidative Phosphorylation in the 31P Magnetic Resonance Spectrum

    PubMed Central

    Conley, Kevin E.; Ali, Amir S.; Flores, Brandon; Jubrias, Sharon A.; Shankland, Eric G.

    2016-01-01

    Natural indicators provide intrinsic probes of metabolism, biogenesis and oxidative protection. Nicotinamide adenine dinucleotide metabolites (NAD(P)) are one class of indicators that have roles as co-factors in oxidative phosphorylation, glycolysis, and anti-oxidant protection, as well as signaling in the mitochondrial biogenesis pathway. These many roles are made possible by the distinct redox states (NAD(P)+ and NAD(P)H), which are compartmentalized between cytosol and mitochondria. Here we provide evidence for detection of NAD(P)+ and NAD(P)H in separate mitochondrial and cytosol pools in vivo in human tissue by phosphorus magnetic resonance spectroscopy (31P MRS). These NAD(P) pools are identified by chemical standards (NAD+, NADP+, and NADH) and by physiological tests. A unique resonance reflecting mitochondrial NAD(P)H is revealed by the changes elicited by elevation of mitochondrial oxidation. The decline of NAD(P)H with oxidation is matched by a stoichiometric rise in the NAD(P)+ peak. This unique resonance also provides a measure of the improvement in mitochondrial oxidation that parallels the greater phosphorylation found after exercise training in these elderly subjects. The implication is that the dynamics of the mitochondrial NAD(P)H peak provides an intrinsic probe of the reversal of mitochondrial dysfunction in elderly muscle. Thus, non-invasive detection of NAD(P)+ and NAD(P)H in cytosol vs. mitochondria yields natural indicators of redox compartmentalization and sensitive intrinsic probes of the improvement of mitochondrial function with an intervention in human tissues in vivo. These natural indicators hold the promise of providing mechanistic insight into metabolism and mitochondrial function in vivo in a range of tissues in health, disease and with treatment. PMID:27065875

  16. Higgs-Boson Production in Nucleus-Nucleus Collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    1992-01-01

    Cross section calculations are presented for the production of intermediate-mass Higgs bosons produced in ultrarelativistic nucleus-nucleus collisions via two photon fusion. The calculations are performed in position space using Baur's method for folding together the Weizsacker-Williams virtual-photon spectra of the two colliding nuclei. It is found that two photon fusion in nucleus-nucleus collisions is a plausible way of finding intermediate-mass Higgs bosons at the Superconducting Super Collider or the CERN Large Hadron Collider.

  17. Higgs-boson production in nucleus-nucleus collisions

    NASA Technical Reports Server (NTRS)

    Norbury, J. W.; Townsend, L. W. (Principal Investigator)

    1990-01-01

    Cross-section calculations are presented for the production of intermediate-mass Higgs bosons produced in ultrarelativistic nucleus-nucleus collisions via two-photon fusion. The calculations are performed in position space using Baur's method for folding together the Weizsacker-Williams virtual-photon spectra of the two colliding nuclei. It is found that two-photon fusion in nucleus-nucleus collisions is a plausible way of finding intermediate-mass Higgs bosons at the Superconducting Super Collider or the CERN Large Hadron Collider.

  18. Networking the nucleus

    PubMed Central

    Rajapakse, Indika; Scalzo, David; Tapscott, Stephen J; Kosak, Steven T; Groudine, Mark

    2010-01-01

    The nuclei of differentiating cells exhibit several fundamental principles of self-organization. They are composed of many dynamical units connected physically and functionally to each other—a complex network—and the different parts of the system are mutually adapted and produce a characteristic end state. A unique cell-specific signature emerges over time from complex interactions among constituent elements that delineate coordinate gene expression and chromosome topology. Each element itself consists of many interacting components, all dynamical in nature. Self-organizing systems can be simplified while retaining complex information using approaches that examine the relationship between elements, such as spatial relationships and transcriptional information. These relationships can be represented using well-defined networks. We hypothesize that during the process of differentiation, networks within the cell nucleus rewire according to simple rules, from which a higher level of order emerges. Studying the interaction within and among networks provides a useful framework for investigating the complex organization and dynamic function of the nucleus. PMID:20664641

  19. Theoretical Studies on the Fe-M Interactions and 31P NMR in Fe(CO)3(EtPhPpy)2MX2 (X = NCS, SCN, Cl; M = Zn, Cd, Hg)

    NASA Astrophysics Data System (ADS)

    Huang, Xiao-xuan; Xu, Xuan; Xie, Mei-xiang

    2008-10-01

    To study the Fe-M interactions and their effects on 31P NMR, the structures of Fe(CO)3(EtPhPpy)2 1, Fe(CO)3(EtPhPpy)2M(NCS)2 (2: M = Zn, 3: M = Cd, 4: M = Hg) and Fe(CO)3(EtPhPpy)2CdX2 (5: X = C1, 6: X = SCN) were investigated by density functional theory (DFT) PBE0 method. The stabilities S of complexes follow S(2)>S(3)>S(4) and S(3)approxS(6)>S(5), indicating that 6 is stable and may be synthesized. The complexes with thiocyanate are more stable than that with chloride in Fe(CO)3(EtPhPpy)2CdX2. The strength / of Fe-M interactions follows I(2)approxI(3)nucleus is increased, and thus upfield 31P chemical shifts are caused (compared with mononuclear complex 1).

  20. Electric quadrupole excitations in relativistic nucleus-nucleus collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    1989-01-01

    Calculations are presented for electric quadrupole excitations in relativistic nucleus-nucleus collisions. The theoretical results are compared to an extensive data set and it is found that electric quadrupole effects provide substantial corrections to cross sections, especially for heavier nuclei.

  1. Meson multiplicity versus energy in relativistic nucleus-nucleus collisions

    NASA Technical Reports Server (NTRS)

    Atwater, T. W.; Freier, P. S.

    1986-01-01

    A systematic study of meson multiplicity as a function of energy at energies up to 100 GeV/u in nucleus-nucleus collisions has been made, using cosmic-ray data in nuclear emulsion. The data are consistent with simple nucleon-nucleon superposition models. Multiplicity per interacting nucleon in AA collisions does not appear to differ significantly from pp collisions.

  2. Scaling phenomenon in relativistic nucleus-nucleus collisions

    SciTech Connect

    Wong, C. Y.; Blankenbecler, R.

    1980-01-01

    New scaling variables for proton and pion production in relativistic nucleus-nucleus collisions are introduced which are the generalizations of the Feynmann scaling variable. They allow a simple description of the cross sections at forward and backward angles. 2 figures.

  3. Momentum loss in proton-nucleus and nucleus-nucleus collisions

    NASA Technical Reports Server (NTRS)

    Khan, Ferdous; Townsend, Lawrence W.

    1993-01-01

    An optical model description, based on multiple scattering theory, of longitudinal momentum loss in proton-nucleus and nucleus-nucleus collisions is presented. The crucial role of the imaginary component of the nucleon-nucleon transition matrix in accounting for longitudinal momentum transfer is demonstrated. Results obtained with this model are compared with Intranuclear Cascade (INC) calculations, as well as with predictions from Vlasov-Uehling-Uhlenbeck (VUU) and quantum molecular dynamics (QMD) simulations. Comparisons are also made with experimental data where available. These indicate that the present model is adequate to account for longitudinal momentum transfer in both proton-nucleus and nucleus-nucleus collisions over a wide range of energies.

  4. The Galactic Nucleus

    NASA Astrophysics Data System (ADS)

    Melia, Fulvio

    Exciting new broadband observations of the galactic nucleus have placed the heart of the Milky Way under intense scrutiny in recent years. This has been due in part to the growing interest from theorists motivated to study the physics of black hole accretion, magnetized gas dynamics, and unusual star formation. The center of our Galaxy is now known to harbor the most compelling supermassive black hole candidate, weighing in at 3-4 million solar masses. Its nearby environment is comprised of a molecular dusty ring, clusters of evolved and young stars, diffuse hot gas, ionized gas streamers, and several supernova remnants. This chapter will focus on the physical makeup of this dynamic region and the feasibility of actually imaging the black hole's shadow in the coming decade with mm interferometry.

  5. Interaction of Lipopolysaccharide and Phospholipid in Mixed Membranes: Solid-State 31P-NMR Spectroscopic and Microscopic Investigations

    PubMed Central

    Nomura, Kaoru; Inaba, Takehiko; Morigaki, Kenichi; Brandenburg, Klaus; Seydel, Ulrich; Kusumoto, Shoichi

    2008-01-01

    Lipopolysaccharide (LPS), which constitutes the outermost layer of Gram-negative bacterial cells as a typical component essential for their life, induces the first line defense system of innate immunity of higher animals. To understand the basic mode of interaction between bacterial LPS and phospholipid cell membranes, distribution patterns were studied by various physical methods of deep rough mutant LPS (ReLPS) of Escherichia coli incorporated in phospholipid bilayers as simple models of cell membranes. Solid-state 31P-NMR spectroscopic analysis suggested that a substantial part of ReLPS is incorporated into 1,2-dimyristoyl-sn-glycero-3-phosphocholine lipid bilayers when multilamellar vesicles were prepared from mixtures of these. In egg L-α-phosphatidylcholine (egg-PC)-rich membranes, ReLPS undergoes micellization. In phosphatidylethanolamine-rich membranes, however, micellization was not observed. We studied by microscopic techniques the location of ReLPS in membranes of ReLPS/egg-PC (1:10 M/M) and ReLPS/egg-PC/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) (1:9:1 M/M/M). The influence of ReLPS on the physicochemical properties of the membranes was studied as well. Microscopic images of both giant unilamellar vesicles and supported planar lipid bilayers showed that LPS was uniformly incorporated in the egg-PC lipid bilayers. In the egg-PC/POPG (9:1 M/M) lipid bilayers, however, ReLPS is only partially incorporated and becomes a part of the membrane in a form of aggregates (or as mixed aggregates with the lipids) on the bilayer surface. The lipid lateral diffusion coefficient measurements at various molar ratios of ReLPS/egg-PC/POPG indicated that the incorporated ReLPS reduces the diffusion coefficients of the phospholipids in the membrane. The retardation of diffusion became more significant with increasing POPG concentrations in the membrane at high ReLPS/phospholipid ratios. This work demonstrated that the phospholipid composition has critical

  6. 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

  7. Antiproton-nucleus interaction

    NASA Astrophysics Data System (ADS)

    Cugnon, J.; Vandermeulen, J.

    The antiproton-nucleus physics is reviewed. On the experimental side, the recent results obtained at the LEAR, BNL and KEK facilities are analyzed. A brief summary of the main pp and pn experimental data is also given. The antiproton-nucleus interaction can lead to elasic, inelastic and charge exchange scattering and to annihilation. The latter is very dominant. The scattering cross-sections are usually analyzed in terms of complex potential models. The relationship between potentials, charge conjugation and Dirac phenomenology is discussed. Much emphasis is put on the dynamics of the antiproton annihilation on nuclei. The energy transfer, pion absorption and target response are analyzed within the intranuclear cascade model. Special interest is devoted to strangeness production, hypernucleus formation and possible annihilation on two nucleons. Signatures for this new process are searched in experimental data. Finally, the highly debated question of quark-gluon formation is analyzed. Cet article constitue une revue de la physique antiproton-noyau. Du point de vue expérimental, cette revue porte particulièrement sur les récents résultats obtenus à LEAR, BNL et KEK. On y a aussi inclus une mise à jour des faits expérimentaux principaux pour pp et pn. L'interaction antiproton-noyau conduit à la diffusion élastique, inélastique et d'xA9change de charge et à des processus d'annihilation. Habituellement, les expériences de diffusion sont analysées en termes de potentiels complexes. La relation entre ces potentiels, la conjugaison de charge et la phénoménologie de Dirac est discutée. On s'est particulièrement intéressé à la dynamique de l'annihilation d'antiprotons sur des noyaux. Le transfert d'énergie, l'absorption de pions et la réponse de la cible sont analysés dans le cadre du modèle de cascade intranucléaire. Certains autres points sont discutés plus en détail: la production d'étrangeté, la formation d'hypernoyaux et l'annihilation sur

  8. In vivo (31) P MRS assessment of intracellular NAD metabolites and NAD(+) /NADH redox state in human brain at 4 T.

    PubMed

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

    2016-07-01

    NAD(+) and NADH play key roles in cellular respiration. Intracellular redox state defined by the NAD(+) /NADH ratio (RX) reflects the cellular metabolic and physiopathological status. By taking advantage of high/ultrahigh magnetic field strengths, we have recently established a novel in vivo (31) P MRS-based NAD assay for noninvasive and quantitative measurements of intracellular NAD concentrations and redox state in animal and human brains at 16.4 T, 9.4 T and 7 T. To explore its potential for clinical application, in this study we investigated the feasibility of assessing the NAD metabolism and redox state in human brain at a lower field of 4 T by incorporating the (1) H-decoupling technique with the in vivo (31) P NAD assay. The use of (1) H decoupling significantly narrowed the linewidths of NAD and α-ATP resonances, resulting in higher sensitivity and better spectral resolution as compared with the (1) H-coupled (31) P spectrum. These improvements made it possible to reliably quantify cerebral NAD concentrations and RX, consistent with previously reported results obtained from similar age human subjects at 7 T. In summary, this work demonstrates the capability and utility of the (1) H-decoupled (31) P MRS-based NAD assay at lower field strength; thus, it opens new opportunities for studying intracellular NAD metabolism and redox state in human brain at clinical settings. This conclusion is supported by the simulation results, indicating that similar performance and reliability as observed at 4T can be achieved at 3 T with the same signal-to-noise ratio. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27257783

  9. [31P-NMR analysis of high energy phosphorous compounds (ATP and phosphocreatine) in the living rat brain--effects of halothane anesthesia and a hypoxic condition].

    PubMed

    Yuasa, T; Miyatake, T; Kuwabara, T; Umeda, M; Eguchi, K

    1983-11-01

    31phosphorus nuclear magnetic resonance (31P-NMR) measurements have provided new and valuable insights for studying the metabolism of living systems. The aim of this paper is to introduce a technique of application of 31P-NMR measurements using a surface coil method, and to discuss the effects of halothane anesthesia and hypoxic hypoxia on the energetic metabolism of intact rat brains. All measurements were made using a JEOL FX 270 spectrometer with a super conducting magnet of 54-mm bore diameter. The magnetic field intensity of this machine is 6.3 tesla, and the resonance frequency used for 31P was 109.14 MHz. We remodelled an ordinary probe to take a live rat, and the animals were made to inhale anesthetic halothane or mixture of oxygen and nitrogen at various concentrations controlled by a flow regulator. The best conditions for measurements with our surface coil method were determined in this study as follows: (1) 90 degrees pulse width and selectivity, Fig. 1 shows signal selectivity in depthwise direction changed with 90 degrees pulse width, which was set to 20 microseconds. (2) Sensitivity and resolution; To obtain a spectrum of 31P-NMR from a rat brain 500 accumulations of free induction decays were considered suitable for both time and space resolution. Fig. 2 shows variations of signal intensity with pulse repetition time, which was set to 2 sec. It took about 17 min for averaging to get a spectrogram. (3) Quantitative accuracy and qualification; As shown in Fig. 3, a linear relationship was found between the signal intensity of beta-phosphate of ATP and the concentration of ATP solutions, thus proving the quantitative accuracy of our systems.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:6661335

  10. Assessment of Preparation Methods for Organic Phosphorus Analysis in Phosphorus-Polluted Fe/Al-Rich Haihe River Sediments Using Solution 31P-NMR

    PubMed Central

    Zhang, Wenqiang; Shan, Baoqing; Zhang, Hong; Tang, Wenzhong

    2013-01-01

    Fe/Al-rich river sediments that were highly polluted with phosphorus (P) were used in tests to determine the optimum preparation techniques for measuring organic P (Po) using solution 31P nuclear magnetic resonance spectroscopy (31P-NMR). The optimum pre-treatment, extraction time, sediment to solution ratio and sodium hydroxide-ethylenediaminetetraacetic acid (NaOH-EDTA) extractant solution composition were determined. The total P and Po recovery rates were higher from freeze- and air-dried samples than from fresh samples. An extraction time of 16 h was adequate for extracting Po, and a shorter or longer extraction time led to lower recoveries of total P and Po, or led to the degradation of Po. An ideal P recovery rate and good-quality NMR spectra were obtained at a sediment:solution ratio of 1∶10, showing that this ratio is ideal for extracting Po. An extractant solution of 0.25 M NaOH and 50 mM EDTA was found to be more appropriate than either NaOH on its own, or a more concentrated NaOH-EDTA mixture for 31P-NMR analysis, as this combination minimized interference from paramagnetic ions and was appropriate for the detected range of Po concentrations. The most appropriate preparation method for Po analysis, therefore, was to extract the freeze-dried and ground sediment sample with a 0.25 M NaOH and 50 mM EDTA solution at a sediment:solution ratio of 1∶10, for 16 h, by shaking. As lyophilization of the NaOH-EDTA extracts proved to be an optimal pre-concentration method for Po analysis in the river sediment, the extract was lyophilized as soon as possible, and analyzed by 31P-NMR. PMID:24143192

  11. 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

  12. Phosphorus speciation in agro-industrial byproducts: sequential fractionation, solution (31)P NMR, and P K- and L(2,3)-edge XANES spectroscopy.

    PubMed

    Negassa, Wakene; Kruse, Jens; Michalik, Dirk; Appathurai, Narayana; Zuin, Lucia; Leinweber, Peter

    2010-03-15

    Little is known about P species in agro-industrial byproducts from developing countries, which may be either pollutants or valuable soil amendments. The present study speciated P in dry (COD) and wet (COW) coffee, sisal (SIS), barley malt (BEB) and sugar cane processing (FIC) byproducts, and filter cakes of linseed (LIC) and niger seed (NIC)with sequential fractionation, solution (31)P nuclear magnetic resonance (NMR) spectroscopy, and P K- and L(2,3)-edge X-ray absorption near-edge structure (XANES) spectroscopy. The sequential P fractionation recovered 59% to almost 100% of total P (P(t)), and more than 50% of P(t) was extracted by H(2)O and NaHCO(3) in five out of seven samples. Similarly, the NaOH + EDTA extraction for solution (31)P NMR recovered 48-94% of P(t). The (31)P NMR spectra revealed orthophosphate (6-81%), pyrophosphate (0-10%), and orthophosphate monoesters (6-94%). Orthophosphate predominated in COD, COW, SIS, and FIC, whereas BEB, UC, and NIC were rich in orthophosphate monoesters. The concentrations of P(i), and P(o) determined in the sequential and NaOH + EDTA extractions and (31)P NMR spectra were strongly and positively correlated (r = 0.88-1.00). Furthermore, the P K- and L(2,3)-edge XANES confirmed the H(2)SO(4)--P(i) detected in the sequential fractionation by unequivocal identification of Ca--P phases in a few samples. The results indicate that the combined use of all four analytical methods is crucial for comprehensive P speciation in environmental samples and the application of these byproducts to soil. PMID:20146464

  13. Vacuolar glyphosate-sequestration correlates with glyphosate resistance in ryegrass (Lolium spp.) from Australia, South America, and Europe: a 31P NMR investigation.

    PubMed

    Ge, Xia; d'Avignon, D André; Ackerman, Joseph J H; Collavo, Alberto; Sattin, Maurizio; Ostrander, Elizabeth L; Hall, Erin L; Sammons, R Douglas; Preston, Christopher

    2012-02-01

    Lolium spp., ryegrass, variants from Australia, Brazil, Chile, and Italy showing differing levels of glyphosate resistance were examined by (31)P NMR. Extents of glyphosate (i) resistance (LD(50)), (ii) inhibition of 5-enopyruvyl-shikimate-3-phosphate synthase (EPSPS) activity (IC(50)), and (iii) translocation were quantified for glyphosate-resistant (GR) and glyphosate-sensitive (GS) Lolium multiflorum Lam. variants from Chile and Brazil. For comparison, LD(50) and IC(50) data for Lolium rigidum Gaudin variants from Italy were also analyzed. All variants showed similar cellular uptake of glyphosate by (31)P NMR. All GR variants showed glyphosate sequestration within the cell vacuole, whereas there was minimal or no vacuole sequestration in the GS variants. The extent of vacuole sequestration correlated qualitatively with the level of resistance. Previous (31)P NMR studies of horseweed ( Conyza canadensis (L.) Cronquist) revealed that glyphosate sequestration imparted glyphosate resistance. Data presented herein suggest that glyphosate vacuolar sequestration is strongly contributing, if not the major contributing, resistance mechanism in ryegrass as well. PMID:22224711

  14. {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.

  15. /sup 31/P NMR saturation-transfer and /sup 13/C NMR kinetic studies of glycolytic regulation during anaerobic and aerobic glycolysis

    SciTech Connect

    Campbell-Burk, S.L.; den Hollander, J.A.; Alger, J.R.; Shulman, R.G.

    1987-11-17

    /sup 31/P NMR saturation-transfer techniques have been employed in glucose-gown derepressed yeast to determine unidirectional fluxes in the upper part of the Embden-Meyerhof-Parnas pathway. The experiments were performed during anaerobic and aerobic glycolysis by saturating the ATP/sub ..gamma../ resonances and monitoring changes in the phosphomonoester signals from glucose 6-phosphate and fructose 1,6-bisphosphate. These experiments were supplemented with /sup 13/C NMR measurements of glucose utilization rates and /sup 13/C NMR label distribution studies. Combined with data obtained previously from radioisotope measurement, these /sup 31/P and /sup 13/C NMR kinetic studies allowed estimation of the net glycolytic flow in addition to relative flows through phosphofructokinase (PFK) and Fru-1,6-P/sub 2/ase during anaerobic and aerobic glycolysis. The /sup 31/P NMR saturation-transfer results are consistent with previous results obtained from measurements of metabolite levels, radioisotope data, and /sup 13/C NMR studies, providing additional support for in vivo measurement of the flows during glycolysis.

  16. Development of a CP 31P NMR broadline simulation methodology for studying the interactions of antihypertensive AT1 antagonist losartan with phospholipid bilayers.

    PubMed

    Fotakis, Charalambos; Christodouleas, Dionisios; Chatzigeorgiou, Petros; Zervou, Maria; Benetis, Nikolas-Ploutarch; Viras, Kyriakos; Mavromoustakos, Thomas

    2009-03-18

    A cross-polarization (CP) (31)P 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 AT(1) transmembrane receptors. The results were complemented and compared with those of differential scanning calorimetry, solid-state (13)C 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 (31)P 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 sigma(iso) of the (31)P 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

  17. Mechanics of the Nucleus

    PubMed Central

    Lammerding, Jan

    2015-01-01

    The nucleus is the distinguishing feature of eukaryotic cells. Until recently, it was often considered simply as a unique compartment containing the genetic information of the cell and associated machinery, without much attention to its structure and mechanical properties. This article provides compelling examples that illustrate how specific nuclear structures are associated with important cellular functions, and how defects in nuclear mechanics can cause a multitude of human diseases. During differentiation, embryonic stem cells modify their nuclear envelope composition and chromatin structure, resulting in stiffer nuclei that reflect decreased transcriptional plasticity. In contrast, neutrophils have evolved characteristic lobulated nuclei that increase their physical plasticity, enabling passage through narrow tissue spaces in their response to inflammation. Research on diverse cell types further demonstrates how induced nuclear deformations during cellular compression or stretch can modulate cellular function. Pathological examples of disturbed nuclear mechanics include the many diseases caused by mutations in the nuclear envelope proteins lamin A/C and associated proteins, as well as cancer cells that are often characterized by abnormal nuclear morphology. In this article, we will focus on determining the functional relationship between nuclear mechanics and cellular (dys-)function, describing the molecular changes associated with physiological and pathological examples, the resulting defects in nuclear mechanics, and the effects on cellular function. New insights into the close relationship between nuclear mechanics and cellular organization and function will yield a better understanding of normal biology and will offer new clues into therapeutic approaches to the various diseases associated with defective nuclear mechanics. PMID:23737203

  18. Two Neutron Removal in Relativistic Nucleus-Nucleus Reactions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    1992-01-01

    Significant discrepancies between theory and experiment have previously been noted for double neutron removal via electromagnetic processes in relativistic nucleus-nucleus collisions. The present work examines the cause of these discrepancies and systematically investigates whether the problem might be due to electromagnetic theory, nuclear contributions, or an underestimate of experimental error. Using cross section systematics from other reactions it is found that the discrepancies can be resolved in a plausible manner.

  19. Unexpected doubly-magic nucleus.

    SciTech Connect

    Janssens, R. V. F.; Physics

    2009-01-01

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

  20. Sensitivity of cross sections for elastic nucleus-nucleus scattering to halo nucleus density distributions

    SciTech Connect

    Alkhazov, G. D.; Sarantsev, V. V.

    2012-12-15

    In order to clear up the sensitivity of the nucleus-nucleus scattering to the nuclear matter distributions in exotic halo nuclei, we have calculated differential cross sections for elastic scattering of the {sup 6}He and {sup 11}Li nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon with different assumed nuclear density distributions in {sup 6}He and {sup 11}Li.

  1. 31P-nuclear magnetic resonance spectroscopy in vivo of six human melanoma xenograft lines: tumour bioenergetic status and blood supply.

    PubMed Central

    Lyng, H.; Olsen, D. R.; Southon, T. E.; Rofstad, E. K.

    1993-01-01

    Six human melanoma xenograft lines grown s.c. in BALB/c-nu/nu mice were subjected to 31P-nuclear magnetic resonance (31P-NMR) spectroscopy in vivo. The following resonances were detected: phosphomonoesters (PME), inorganic phosphate (Pi), phosphodiesters (PDE), phosphocreatine (PCr) and nucleoside triphosphate gamma, alpha and beta (NTP gamma, alpha and beta). The main purpose of the work was to search for possible relationships between 31P-NMR resonance ratios and tumour pH on the one hand and blood supply per viable tumour cell on the other. The latter parameter was measured by using the 86Rb uptake method. Tumour bioenergetic status [the (PCr + NTP beta)/Pi resonance ratio], tumour pH and blood supply per viable tumour cell decreased with increasing tumour volume for five of the six xenograft lines. The decrease in tumour bioenergetic status was due to a decrease in the (PCr + NTP beta)/total resonance ratio as well as an increase in the Pi/total resonance ratio. The decrease in the (PCr + NTP beta)/total resonance ratio was mainly a consequence of a decrease in the PCr/total resonance ratio for two lines and mainly a consequence of a decrease in the NTP beta/total resonance ratio for three lines. The magnitude of the decrease in the (PCr + NTP beta)/total resonance ratio and the magnitude of the decrease in tumour pH were correlated to the magnitude of the decrease in blood supply per viable tumour cell. Tumour pH decreased with decreasing tumour bioenergetic status, and the magnitude of this decrease was larger for the tumour lines showing a high than for those showing a low blood supply per viable tumour cell. No correlations across the tumour lines were found between tumour pH and tumour bioenergetic status or any other resonance ratio on the one hand and blood supply per viable tumour cell on the other. The differences in the 31P-NMR spectrum between the tumour lines were probably caused by differences in the intrinsic biochemical properties of the tumour

  2. 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.

  3. 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

  4. 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. PMID:26451872

  5. 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.

  6. 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. PMID:12724829

  7. Quantitative study of atomic ordering in Ga0.5In0.5P thin films by 31P nuclear magnetic resonance

    NASA Astrophysics Data System (ADS)

    Tycko, Robert; Dabbagh, Gary; Kurtz, Sarah R.; Goral, John P.

    1992-06-01

    We use 31P nuclear-magnetic-resonance (NMR) spectra to measure the degree of cation ordering in thin films of the semiconductor alloy Ga0.5In0.5P grown by organometallic vapor-phase epitaxy. We show that the five possible GanIn4-nP clusters in GaxIn1-xP give rise to resolved NMR lines under magic-angle spinning, allowing a determination of the degree of cation ordering from the relative areas of the five lines. The ordering is shown to be weak (order parameter <=0.6) even in films that appear highly ordered in transmission electron microscopy.

  8. ¹¹³Cd NMR experiments reveal an unusual metal cluster in the solution structure of the yeast splicing protein Bud31p.

    PubMed

    van Roon, Anne-Marie M; Yang, Ji-Chun; Mathieu, Daniel; Bermel, Wolfgang; Nagai, Kiyoshi; Neuhaus, David

    2015-04-13

    Establishing the binding topology of structural zinc ions in proteins is an essential part of their structure determination by NMR spectroscopy. Using (113)Cd NMR experiments with (113)Cd-substituted samples is a useful approach but has previously been limited mainly to very small protein domains. Here we used (113)Cd NMR spectroscopy during structure determination of Bud31p, a 157-residue yeast protein containing an unusual Zn3Cys9 cluster, demonstrating that recent hardware developments make this approach feasible for significantly larger systems. PMID:25703931

  9. {sup 31}P NMR analysis of coal moieties bearing -OH, -NH, and -SH functions. Quarterly report, June 1, 1991--August 31, 1991

    SciTech Connect

    Verkade, J.G.

    1991-12-31

    The purpose of this research is to develop a convenient, reliable and rapid NMR method for the determination of labile-hydrogen functional groups and organic sulfur compounds which are components of coal and coal-derived materials. For this purpose, the former functional groups, including water molecules, are derivatized with reagents containing NMR-active nuclei such as {sup 31}P or {sup 119}Sn, while sulfur groups are derivatized with {sup 195}Pt NMR tagging reagents. Knowledge of the heteroatom composition of coals is necessary for the development of increasingly sophisticated coal processing technologies.

  10. 113Cd NMR Experiments Reveal an Unusual Metal Cluster in the Solution Structure of the Yeast Splicing Protein Bud31p**

    PubMed Central

    van Roon, Anne-Marie M; Yang, Ji-Chun; Mathieu, Daniel; Bermel, Wolfgang; Nagai, Kiyoshi; Neuhaus, David

    2015-01-01

    Establishing the binding topology of structural zinc ions in proteins is an essential part of their structure determination by NMR spectroscopy. Using 113Cd NMR experiments with 113Cd-substituted samples is a useful approach but has previously been limited mainly to very small protein domains. Here we used 113Cd NMR spectroscopy during structure determination of Bud31p, a 157-residue yeast protein containing an unusual Zn3Cys9 cluster, demonstrating that recent hardware developments make this approach feasible for significantly larger systems. PMID:25703931

  11. Double Nucleus in M83

    NASA Astrophysics Data System (ADS)

    Mast, Damián; Díaz, Rubén J.; Agüero, M. Paz

    2006-03-01

    M83 is one of the nearest galaxies with enhanced nuclear star formation, and it presents one of the best opportunities to study the kinematics and physical properties of a circumnuclear starburst. Our three-dimensional spectroscopy data in the R band confirm the presence of a secondary nucleus or mass concentration (previously suggested by Thatte and coworkers). We determine the position of this hidden nucleus, which would be more massive than the visible one and was not detected in the optical Hubble Space Telescope images due, probably, to the strong dust extinction. Using a Keplerian approximation, we estimated for the optical nucleus a mass of (5.0+/-0.8)×106 Msolar/sini (r<1.5"), and for the hidden nucleus, located 4''+/-1'' to the northwest (position angle of 271deg+/-15deg) of the optical nucleus, a mass of (1.00+/-0.08)×107 Msolar/sini (r<1.5"). The emission-line ratio map also unveils the presence of a second circumnuclear ring structure, previously discovered by IR imaging (Elmegreen and coworkers). The data allow us to resolve the behavior of the interstellar medium inside the circumnuclear ring and around the binary mass concentration.

  12. Nucleus management with irrigating vectis.

    PubMed

    Srinivasan, Aravind

    2009-01-01

    The main objective in modern cataract surgery is to achieve a better unaided visual acuity with rapid post-surgical recovery and minimal surgery-related complications. Early visual rehabilitation and better unaided vision can be achieved only by reducing the incision size. In manual small incision cataract surgery (MSICS), incision is between 5.5 to 7 mm. Once the nucleus is prolapsed into the anterior chamber, it can be extracted through the tunnel. Nucleus extraction with an irrigating vectis is a very simple technique, which combines mechanical and hydrostatic forces to express out the nucleus. This technique is time-tested with good results and more than 95% of nuclei in MSICS are extracted in this way offering all the merits of phacoemulsification with the added benefits of having wider applicability, better safety, shorter learning curve and lower cost. PMID:19075403

  13. 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

  14. Temperature-dependent interconversion of phosphoramidite-Cu complexes detected by combined diffusion studies, 31P NMR, and low-temperature NMR spectroscopy.

    PubMed

    Schober, Katrin; Zhang, Hongxia; Gschwind, Ruth M

    2008-09-17

    For copper-catalyzed enantioselective conjugate additions, knowledge about the precatalytic and catalytic complexes has not yet been sufficiently developed to understand the strong influence of different temperatures on these famous reactions. Therefore, NMR experiments with four Cu(I) salts and two phosphoramidite ligands have been performed to elucidate the temperature dependence and the low-temperature structures of these copper complexes. The existence of the precatalytic binuclear complex with a mixed trigonal/tetrahedral coordination on copper is for the first time proven with direct NMR spectroscopic methods. Below 200 K, intermolecular interactions between free ligands and [Cu2X2L3] complexes induce binuclear [Cu2X2L4] complexes similar to the crystal structures. By combining diffusion experiments and (31)P integrals at different temperatures, it is for the first time possible to follow the formation of stoichiometrically different complexes, even under experimental conditions in which the (31)P signals of the complexes are spectroscopically not resolved due to exchange processes. This allows a first correlation between the complex species observed and the synthetic conditions reported. Furthermore, different preferences to build homo- or heterochiral complexes are detected for binaphthol and biphenol phosphoramidite complexes. PMID:18717560

  15. Trimethylphosphine-Assisted Surface Fingerprinting of Metal Oxide Nanoparticle by (31)P Solid-State NMR: A Zinc Oxide Case Study.

    PubMed

    Peng, Yung-Kang; Ye, Lin; Qu, Jin; Zhang, Li; Fu, Yingyi; Teixeira, Ivo F; McPherson, Ian James; He, Heyong; Tsang, Shik Chi Edman

    2016-02-24

    Nano metal oxides are becoming widely used in industrial, commercial and personal products (semiconductors, optics, solar cells, catalysts, paints, cosmetics, sun-cream lotions, etc.). However, the relationship of surface features (exposed planes, defects and chemical functionalities) with physiochemical properties is not well studied primarily due to lack of a simple technique for their characterization. In this study, solid state (31)P MAS NMR is used to map surfaces on various ZnO samples with the assistance of trimethylphosphine (TMP) as a chemical probe. As similar to XRD giving structural information on a crystal, it is demonstrated that this new surface-fingerprint technique not only provides qualitative (chemical shift) but also quantitative (peak intensity) information on the concentration and distribution of cations and anions, oxygen vacancies and hydroxyl groups on various facets from a single deconvoluted (31)P NMR spectrum. On the basis of this technique, a new mechanism for photocatalytic •OH radical generation from direct surface-OH oxidation is revealed, which has important implications regarding the safety of using nano oxides in personal care products. PMID:26812527

  16. 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

    2011-03-01

    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. PMID:21254775

  17. Coupling of Li motion and structural distortions in olivine LiMnPO4 from 7Li and 31P NMR

    NASA Astrophysics Data System (ADS)

    Rudisch, Christian; Grafe, Hans-Joachim; Geck, Jochen; Partzsch, Sven; Zimmermann, M. v.; Wizent, Nadja; Klingeler, Rüdiger; Büchner, Bernd

    2013-08-01

    We present a detailed 7Li- and 31P-NMR study on single crystalline LiMnPO4 in the paramagnetic and antiferromagnetic phase (AFM, TN˜34 K). This allows us to determine the spin directions in the field-induced spin-flop phase. In addition, the anisotropic dipolar hyperfine coupling tensor of the 7Li and 31P nuclei is also fully determined by orientation and temperature-dependent NMR experiments and compared to the calculated values from crystal structure data. Deviations of the experimental values from the theoretical ones are discussed in terms of Mn disorder which is induced by Li disorder. In fact, the disorder in the Mn sublattice is directly revealed by diffuse x-ray scattering data. The present results provide experimental evidence for the Li diffusion strongly coupling to structural distortions within the MnPO4 host, which is expected to significantly affect the Li mobility as well as the performance of batteries based on this material.

  18. Studies of uptake and suppresion of Mn/sup 2 +/ migration in highly vacuolated sycamore (Acer pseudoplatanus L) cells by /sup 31/P NMR

    SciTech Connect

    Roby, C.; Bligny, R.; Douce, R.; Pfeffer, P.E.

    1987-04-01

    Recent /sup 31/P NMR studies have demonstrated that Mn/sup 2 +/ appears to invade the cells of heterogeneous excised tissue of corn root tips sequentially, first entering the cytoplasmic compartment, where it complexes with nucleotides and P/sub i/. Under aerobic conditions, further migration across the tonoplast, followed by vacoule trapping was visualized through paramagnetic broadening of the vacoular P/sub i/ resonance. Cultured cells such as Acer pseudoplatanus L offer better opportunities for studying cellular activity by /sup 31/P NMR because of their homogeneity and uniformly rapid response to various metabolic disturbances. In contrast to excised root tissue, Mn/sup 2 +/ showed no measurable accumulation in the cytoplasmic compartments of these cells under aerobic conditions. However, a rapid crossing of the large tonoplast resulted in immediate vacuolar metal ion sequestration. Anoxia did not foster leakage of Mn/sup 2 +/ from the vacuole to the cytoplasm, while hypoxia completely halted all movement of Mn/sup 2 +/ across the plasmalema. This disparity in terms of cell and tissue morphology, membrane permeability and possible tissue trapping of metal ions will be discussed.

  19. Formations of hydroxyapatite and inositol hexakisphosphate in poultry litter during the composting period: sequential fractionation, P K-edge XANES and solution (31)P NMR investigations.

    PubMed

    Hashimoto, Yohey; Takamoto, Akira; Kikkawa, Ren; Murakami, Keiichi; Yamaguchi, Noriko

    2014-05-20

    Little is known about how the solubility and chemical speciation of phosphorus (P) in poultry litters are altered during the composting period. This study investigated the quantitative and qualitative changes in organic P (Po) and inorganic P (Pi) compositions in poultry litters during the seven-day composting period using sequential extraction in combination with P K-edge X-ray absorption near-edge structure (XANES) and solution (31)P nuclear magnetic resonance (NMR) spectroscopy. The result of sequential extraction illustrated that the significant decrease of H2O-P by 55% in poultry litters occurred concomitantly with the increase of HCl-Pi and HCl-Po during the composting period (p < 0.05). X-ray diffraction results for poultry litter samples showed three distinct peaks indicative of hydroxyapatite. Phosphorus K-edge XANES confirmed the increase of hydroxyapatite during the composting period, corresponding to the increase of HCl-Pi determined by the sequential extraction. The NaOH-EDTA extraction for solution (31)P NMR revealed that myo-inositol hexakisphosphate (IHP) constituted about 80% of phosphate monoesters and was increased from 16 to 28% in the poultry litter during the composting period. The combined applications of chemical extraction and molecular-spectroscopic techniques determined that water-soluble P in poultry litter was transformed into less soluble phases, primarily hydroxyapatite and IHP, during the composting period. PMID:24735189

  20. 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.

  1. 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

    2016-01-01

    (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. PMID:26902733

  2. Contribution of magnetic susceptibility effects to transmembrane chemical shift differences in the /sup 31/P NMR spectra of oxygenated erythrocyte suspensions

    SciTech Connect

    Kirk, K.; Kuchel, P.W.

    1988-01-05

    Triethyl phosphate, dimethyl methylphosphonate, and the hypophosphite ion all contain the phosphoryl functional group. When added to an oxygenated erythrocyte suspension, the former compound gives rise to a single /sup 31/P NMR resonance, whereas the latter compounds give rise to separate intra- and extracellular /sup 31/P NMR resonances. On the basis of experiments with intact oxygenated cell suspensions (in which the hematocrit was varied) and with oxygenated cell lysates (in which the lysate concentration was varied) it was concluded that the chemical shifts of the intra- and extracellular populations of triethyl phosphate differ as a consequence of the diamagnetic susceptibility of intracellular oxyhemoglobin but that this difference is averaged by the rapid exchange of the compound across the cell membrane. The difference is the magnetic susceptibility of the intra- and extracellular compartments contributes to the observed separation of the intra- and extracellular resonances of dimethyl methylphosphonate and hypophosphite. The magnitude of this contribution is, however, substantially less than that calculated using a simple two-compartment model and varies with the hematocrit of the suspension. Furthermore, it is insufficient to fully account for the transmembrane chemical shift differences observed for dimethyl methylphosphonate and hypophosphite. An additional effect is operating to move the intracellular resonances of these compounds to a lower chemical shift. The effect is mediated by an intracellular component, and the magnitude of the resultant chemical shift variations depends upon the chemical structure of the phosphoryl compound involved.

  3. 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

  4. 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

  5. The contribution of magnetic susceptibility effects to transmembrane chemical shift differences in the 31P NMR spectra of oxygenated erythrocyte suspensions.

    PubMed

    Kirk, K; Kuchel, P W

    1988-01-01

    Triethyl phosphate, dimethyl methylphosphonate, and the hypophosphite ion all contain the phosphoryl functional group. When added to an oxygenated erythrocyte suspension, the former compound gives rise to a single 31P NMR resonance, whereas the latter compounds give rise to separate intra- and extracellular 31P NMR resonances. On the basis of experiments with intact oxygenated cell suspensions (in which the hematocrit was varied) and with oxygenated cell lysates (in which the lysate concentration was varied), it was concluded that the chemical shifts of the intra- and extracellular populations of triethyl phosphate differ as a consequence of the diamagnetic susceptibility of intracellular oxyhemoglobin but that this difference is averaged by the rapid exchange of the compound across the cell membrane. The difference in the magnetic susceptibility of the intra- and extracellular compartments contributes to the observed separation of the intra- and extracellular resonances of dimethyl methylphosphonate and hypophosphite. The magnitude of this contribution is, however, substantially less than that calculated using a simple two-compartment model and varies with the hematocrit of the suspension. Furthermore, it is insufficient to fully account for the transmembrane chemical shift differences observed for dimethyl methylphosphonate and hypophosphite. An additional effect is operating to move the intracellular resonances of these compounds to a lower chemical shift. The effect is mediated by an intracellular component, and the magnitude of the resultant chemical shift variations depends upon the chemical structure of the phosphoryl compound involved. PMID:3275636

  6. Cometary nucleus and active regions

    NASA Technical Reports Server (NTRS)

    Whipple, F. L.

    1984-01-01

    On the basis of the icy conglomerate model of cometary nuclei, various observations demonstrate the spotted nature of many or most nuclei, i.e., regions of unusual activity, either high or low. Rotation periods, spin axes and even precession of the axes are determined. The observational evidence for variations in activity over the surfaces of cometary nuclei are listed and discussed. On June 11 the comet IRAS-ARAKI-ALCOCK approached the Earth to a distance of 0.031 AU, the nearest since C/Lexell, 1770 I, providing a unique opportunity for near-nucleus observations. Preliminary analysis of these images establishes the spin axis of the nucleus, with an oblioquity to the orbit plane of approximately 50 deg, and a lag angle of sublimation approximately 35 deg from the solar meridian on the nucleus. Asymmetries of the inner coma suggests a crazy-quilt distribution of ices with differing volatility over the surface of the nucleus. The observations of Comet P/Homes 1892 III, exhibiting two 8-10 magnitude bursts, are carefully analyzed. The grazing encounter produced, besides the first great burst, an active area on the nucleus, which was rotating retrograde with a period of 16.3hr and inclination nearly 180 deg. After the first burst the total magnitude fell less than two magnitudes from November 7 to November 30 (barely naked eye) while the nuclear region remained diffuse or complex, rarely if ever showing a stellar appearance. The fading was much more rapid after the second burst. The grazing encounter distributed a volume of large chunks in the neighborhood of the nucleus, maintaining activity for weeks.

  7. Non-invasive assessment of phosphate metabolism and oxidative capacity in working skeletal muscle in healthy young Chinese volunteers using 31P Magnetic Resonance Spectroscopy

    PubMed Central

    Wang, Huiting; Wu, Wenbo; Zhang, Xin; Tian, Chuanshuai; Yu, Haiping; Liu, Renyuan; Zhu, Bin

    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 31P Magnetic Resonance Spectroscopy (31P-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 31P-MRS coil was firmly placed under the middle of the quadriceps . 31P-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 higher

  8. 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

  9. Formin' actin in the nucleus.

    PubMed

    Baarlink, Christian; Grosse, Robert

    2014-01-01

    Many if not most proteins can, under certain conditions, change cellular compartments, such as, for example, shuttling from the cytoplasm to the nucleus. Thus, many proteins may exert functions in various and very different subcellular locations, depending on the signaling context. A large amount of actin regulatory proteins has been detected in the mammalian cell nucleus, although their potential roles are much debated and are just beginning to emerge. Recently, members of the formin family of actin nucleators were also reported to dynamically localize to the nuclear environment. Here we discuss our findings that specific diaphanous-related formins can promote nuclear actin assembly in a signal-dependent manner. PMID:24637338

  10. Acridine: a versatile heterocyclic nucleus.

    PubMed

    Kumar, Ramesh; Kaur, Mandeep; Kumari, Meena

    2012-01-01

    Acridine is a heterocyclic nucleus. It plays an important role in various medicines. A number of therapeutic agents are based on acridine nucleus such as quinacrine (antimalarial), acriflavine and proflavine (antiseptics), ethacridine (abortifacient), amsacrine and nitracine (anticancer), and tacrine. Acridine is obtained from high boiling fraction of coal tar. It is also obtained in nature from plant and marine sources. Acridine undergoes a number of reactions such as nucleophilic addition, electrophilic substitution, oxidation, reduction, reductive alkylation and photoalkylation. The present review article summarizes the synthesis, reaction, literature review and pharmaceutical importance of acridine. PMID:22574501

  11. Measurement of delta(1)J((199)Hg, (31)P) in [HgPCy3(OAc)2]2 and relativistic ZORA DFT investigations of mercury-phosphorus coupling tensors.

    PubMed

    Bryce, David L; Courchesne, Noémie Manuelle Dorval; Perras, Frédéric A

    2009-12-01

    Using 31P solid-state NMR spectroscopy, anisotropy in the indirect 199Hg-31P spin-spin coupling tensor (DeltaJ) for powdered [HgPCy3(OAc)2]2 (1) has been measured as 4700 +/- 300 Hz. Zeroth-order regular approximation (ZORA) density functional theory (DFT) calculations, including scalar and spin-orbit relativistic effects, performed on 1 and a series of other related compounds show that DeltaJ(199Hg, (31)P) arises entirely from the ZORA Fermi-contact-spin-dipolar cross term. The calculations validate assumptions made in the spectral analysis of 1 and in previous determinations of DeltaJ in powder samples, namely that J is axially symmetric and shares its principal axis system with the direct dipolar coupling tensor (D). Agreement between experiment and theory for various 199Hg, 31P spin-spin coupling anisotropies is reasonable; however, experimental values of 1J(199Hg, 31P)(iso) are significantly underestimated by the calculations. The most important improvements in the agreement were obtained as a result of including more of the crystal lattice in the model used for the calculations, e.g., a change of 43% was noted for 1J(199Hg, 31P)(iso) in [HgPPh3(NO3)2]2 depending on whether the two or three nearest nitrate ions are included in the model. Finally, we have written a computer program to simulate the effects of non-axial symmetry in J and of non-coincidence of the J and D on powder NMR spectra. Simulations clearly show that both of these effects have a pronounced impact on the 31P NMR spectrum of 199Hg-31P spin pairs, suggesting that the effects should be observable experimentally if a suitable compound can be identified. PMID:20056396

  12. Functionalized active-nucleus complex sensor

    DOEpatents

    Pines, Alexander; Wemmer, David E.; Spence, Megan; Rubin, Seth

    2003-11-25

    A functionalized active-nucleus complex sensor that selectively associates with one or more target species, and a method for assaying and screening for one or a plurality of target species utilizing one or a plurality of functionalized active-nucleus complexes with at least two of the functionalized active-nucleus complexes having an attraction affinity to different corresponding target species. The functionalized active-nucleus complex has an active-nucleus and a targeting carrier. The method involves functionalizing an active-nucleus, for each functionalized active-nucleus complex, by incorporating the active-nucleus into a macromolucular or molecular complex that is capable of binding one of the target species and then bringing the macromolecular or molecular complexes into contact with the target species and detecting the occurrence of or change in a nuclear magnetic resonance signal from each of the active-nuclei in each of the functionalized active-nucleus complexes.

  13. Higgs and Particle Production in Nucleus-Nucleus Collisions

    NASA Astrophysics Data System (ADS)

    Liu, Zhe

    We apply a diagrammatic approach to study Higgs boson, a color-neutral heavy particle, pro- duction in nucleus-nucleus collisions in the saturation framework without quantum evolution. We assume the strong coupling constant much smaller than one. Due to the heavy mass and colorless nature of Higgs particle, final state interactions are absent in our calculation. In order to treat the two nuclei dynamically symmetric, we use the Coulomb gauge which gives the appropriate light cone gauge for each nucleus. To further eliminate initial state interactions we choose specific prescriptions in the light cone propagators. We start the calculation from only two nucleons in each nucleus and then demonstrate how to generalize the calculation to higher orders diagrammatically. We simplify the diagrams by the Slavnov-Taylor-Ward identities. The resulting cross section is factorized into a product of two Weizsacker-Williams gluon distributions of the two nuclei when the transverse momentum of the produced scalar particle is around the saturation momentum. To our knowledge this is the first process where an exact analytic formula has been formed for a physical process, involving momenta on the order of the saturation momentum, in nucleus-nucleus collisions in the quasi-classical approximation. Since we have performed the calculation in an unconventional gauge choice, we further confirm our results in Feynman gauge where the Weizsacker-Williams gluon distribution is interpreted as a transverse momentum broadening of a hard gluons traversing a nuclear medium. The transverse momentum factorization manifests itself in light cone gauge but not so clearly in Feynman gauge. In saturation physics there are two different unintegrated gluon distributions usually encountered in the literature: the Weizsacker-Williams gluon distribution and the dipole gluon distribution. The first gluon distribution is constructed by solving classical Yang-Mills equation of motion in the Mc

  14. 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

  15. 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

    2015-01-01

    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

  16. Analysis of relativistic nucleus-nucleus interactions in emulsion chambers

    NASA Technical Reports Server (NTRS)

    Mcguire, Stephen C.

    1987-01-01

    The development of a computer-assisted method is reported for the determination of the angular distribution data for secondary particles produced in relativistic nucleus-nucleus collisions in emulsions. The method is applied to emulsion detectors that were placed in a constant, uniform magnetic field and exposed to beams of 60 and 200 GeV/nucleon O-16 ions at the Super Proton Synchrotron (SPS) of the European Center for Nuclear Research (CERN). Linear regression analysis is used to determine the azimuthal and polar emission angles from measured track coordinate data. The software, written in BASIC, is designed to be machine independent, and adaptable to an automated system for acquiring the track coordinates. The fitting algorithm is deterministic, and takes into account the experimental uncertainty in the measured points. Further, a procedure for using the track data to estimate the linear momenta of the charged particles observed in the detectors is included.

  17. Single nucleon emission in relativistic nucleus-nucleus reactions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Townsend, Lawrence W.

    1992-01-01

    Significant discrepancies between theory and experiment have previously been noted for nucleon emission via electromagnetic processes in relativistic nucleus-nucleus collisions. The present work investigates the hypothesis that these discrepancies have arisen due to uncertainties about how to deduce the experimental electromagnetic cross section from the total measured cross section. An optical-model calculation of single neutron removal is added to electromagnetic cross sections and compared to the total experimental cross sections. Good agreement is found thereby resolving some of the earlier noted discrepancies. A detailed comparison to the recent work of Benesh, Cook, and Vary is made for both the impact parameter and the nuclear cross section. Good agreement is obtained giving an independent confirmation of the parameterized formulas developed by those authors.

  18. Dynamical nucleus-nucleus potential at short distances

    SciTech Connect

    Jiang Yongying; Wang Ning; Li Zhuxia; Scheid, Werner

    2010-04-15

    The dynamical nucleus-nucleus potentials for fusion reactions {sup 40}Ca+{sup 40}Ca, {sup 48}Ca+{sup 208}Pb, and {sup 126}Sn+{sup 130}Te are studied with the improved quantum molecular dynamics model together with the extended Thomas-Fermi approximation for the kinetic energies of nuclei. The obtained fusion barrier for {sup 40}Ca+{sup 40}Ca is in good agreement with the extracted fusion barrier from the measured fusion excitation function, and the depths of the fusion pockets are close to the results of time-dependent Hartree-Fock calculations. The energy dependence of the fusion barrier is also investigated. The fusion pocket becomes shallow for a heavy fusion system and almost disappears for heavy nearly symmetric systems, and the obtained potential at short distances is higher than the adiabatic potential.

  19. Azimuthal correlation and collective behavior in nucleus-nucleus collisions

    SciTech Connect

    Mali, P.; Mukhopadhyay, A. Sarkar, S.; Singh, G.

    2015-03-15

    Various flow effects of nuclear and hadronic origin are investigated in nucleus-nucleus collisions. Nuclear emulsion data collected from {sup 84}Kr + Ag/Br interaction at an incident energy of 1.52 GeV per nucleon and from {sup 28}Si + Ag/Br interaction at an incident energy of 14.5 GeV per nucleon are used in the investigation. The transverse momentum distribution and the flow angle analysis show that collective behavior, like a bounce-off effect of the projectile spectators and a sidesplash effect of the target spectators, are present in our event samples. From an azimuthal angle analysis of the data we also see a direct flow of the projectile fragments and of the produced charged particles. On the other hand, for both data samples the target fragments exhibit a reverse flow, while the projectile fragments exhibit an elliptic flow. Relevant flow parameters are measured.

  20. Treatment of glycogenosys type V (McArdle disease) with creatine and ketogenic diet with clinical scores and with 31P-MRS on working leg muscle

    PubMed Central

    Vorgerd, M; Zange, J

    2007-01-01

    Summary McArdle’s disease is caused by genetic defects of the musclespecific 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 31PMRS visible changes in muscle energy metabolism. PMID:17915573

  1. Effects of decreased pH on membrane structural organization of Escherichia coli grown in different fatty acid-supplemented media: a 31P NMR study.

    PubMed

    Ianzini, F; Guidoni, L; Simone, G; Viti, V; Yatvin, M B

    1990-04-01

    Total membranes from Escherichia coli cells grown in different fatty acid-supplemented media have been examined by 31P NMR at different pH values. The isolated inner and outer membranes were also studied and compared to the liposomes formed with the corresponding extracted lipids. While the liposomes show structures that are correlated with lipid composition, degree of fatty acid unsaturation, and pH, the membrane structure is mainly bilayer. The presence of two bilayer phases characterized by different chemical shift anisotropy values (delta nu csa) is detectable at neutral pH; a perturbation of the bilayer phase characterized by the smallest delta nu csa is produced by low pH. Moreover, an isotropic peak is always present in the membrane NMR spectra: its attribution to cardiolipin molecules is discussed on the basis of digestion experiments with phospholipase C. PMID:2181934

  2. Hydration behaviour of POPC/C(12)-Bet mixtures investigated by sorption gravimetry, (31)P NMR spectroscopy and X-ray diffraction.

    PubMed

    Pfeiffer, H; Weichert, H; Klose, G; Heremans, K

    2012-02-01

    The hydration behaviour of mixtures of the zwitterionic phospholipid 1-palmitoyl-2-oleolyl-sn-glycero-3-phosphocholine (POPC) and the zwitterionic surfactant N,N-dimethyl-N-dodecyl-betain (C(12)-Bet) was investigated by sorption gravimetry, solid-state (31)P NMR-spectroscopy and small angle X-ray diffraction (SAXD). Negative excess hydration (dehydration) was found for almost all hydration degrees investigated. This behaviour is explained by the formation of an inner salt between the dipoles of phospholipid and surfactant headgroups that show a reverse sequence of partial charges with respect to the hydrocarbon backbone. The formation of an inner-salt most probably reduces potential water binding sites. Moreover, NMR data suggest that the incorporation of the zwitterionic surfactant into the phospholipid membrane is correlated with reorientation of the phosphate axis towards the membrane director as well as with reduced lateral and wobbling diffusion. PMID:22285958

  3. 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. PMID:23913630

  4. 31P NMR 2D Mapping of Creatine Kinase Forward Flux Rate in Hearts with Postinfarction Left Ventricular Remodeling in Response to Cell Therapy.

    PubMed

    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

  5. High-energy phosphate metabolism during incremental calf exercise in humans measured by 31 phosphorus magnetic resonance spectroscopy (31P MRS).

    PubMed

    Schocke, Michael F H; Esterhammer, Regina; Kammerlander, Christian; Rass, Anton; Kremser, Christian; Fraedrich, Gustav; Jaschke, Werner R; Greiner, Andreas

    2004-01-01

    Several previous 31 phosphorus magnetic resonance spectroscopy ((31)P MRS) studies performing incremental or progressive muscle exercises have observed that a decrease in pH is accompanied with an acceleration in phosphocreatine (PCr) hydrolysis. The purpose of this study was to investigate the relationship between PCr breakdown and pH during isotonic, exhaustive, incremental plantar flexion exercises. We included eight healthy, male volunteers into this study. Using a 1.5 Tesla MR scanner and a self-built exercise bench, we performed serial free induction decay (FID) (31)P MRS measurements with a time resolution of 1 min at rest, isotonic calf muscle exercise, and recovery. The exercise protocol consisted of 5-min intervals with 4.5, 6, 7.5, and 9 W workload followed by 9-min recovery. Changes in PCr and inorganic phosphate (Pi) were determined as percent changes in comparison to the baseline. In addition, pH values were calculated. This study obtained significant decreases in PCr corresponding to the gradual increases in workload. In each workload level that was succeeded by all volunteers, PCr hydrolysis passed into a steady state. After an early biphasic response, we detected a significant decrease in pH from the first to the second minute of the 6-W workload level followed by a further continuous decrease in pH up to the second minute of the recovery phase. The decrease in pH was not accompanied by acceleration in PCr hydrolysis. In conclusion, this study shows that PCr hydrolysis during incremental plantar flexion exercises passes into a steady state at different workload levels. The observed decrease in pH does not result in acceleration of PCr hydrolysis. PMID:14972400

  6. Roles of Arginine and Lysine Residues in the Translocation of a Cell-Penetrating Peptide from 13C, 31P and 19F Solid-State NMR

    PubMed Central

    Su, Yongchao; Doherty, Tim; Waring, Alan J.; Ruchala, Piotr; Hong, Mei

    2009-01-01

    Cell-penetrating peptides (CPPs) are small cationic peptides that cross the cell membrane while carrying macromolecular cargoes. We use solid-state NMR to investigate the structure and lipid interaction of two cationic residues, Arg10 and Lys13, in the CPP penetratin. 13C chemical shifts indicate that Arg10 adopts a rigid β-strand conformation in the liquid-crystalline state of anionic lipid membranes. This behavior contrasts with all other residues observed so far in this peptide, which adopt a dynamic β-turn conformation with coil-like chemical shifts at physiological temperature. Low-temperature 13C-31P distances between the peptide and the lipid phosphates indicate that both the Arg10 guanidinium Cζ and the Lys13 Cε lie in close proximity to the lipid 31P (4.0 - 4.2 Å), proving the existence of charge-charge interaction for both Arg10 and Lys13 in the gel-phase membrane. However, since lysine substitution in CPPs are known to reduce their translocation ability, we propose that low temperature stabilizes both lysine and arginine interactions with the phosphates, whereas at high temperature the lysine-phosphate interaction is much weaker than the arginine-phosphate interaction. This is supported by the unusually high rigidity of the Arg10 sidechain and its β-strand conformation at high temperature. The latter is proposed to be important for ion pair formation by allowing close approach of the lipid headgroups to guanidinium sidechains. 19F and 13C spin diffusion experiments indicate that penetratin is oligomerized into β-sheets in gel-phase membranes. These solid-state NMR data indicate that guanidinium-phosphate interactions exist in penetratin, and guanidinium groups play a stronger structural role than ammonium groups in the lipid-assisted translocation of CPPs across liquid-crystalline cell membranes. PMID:19364134

  7. Topographical analysis of regulatory and metal ion binding sites on glutamine synthetase from Escherichia coli: 13C and 31P nuclear magnetic resonance and fluorescence energy transfer study

    PubMed Central

    Villafranca, J. J.; Rhee, S. G.; Chock, P. B.

    1978-01-01

    The paramagnetic effect of Mn(II) on 13C and 31P nuclear magnetic resonance signals from the [2-13C]ATP adenylylated glutamine synthetase [L-glutamate:ammonia ligase (ADP-forming); EC 6.3.1.2] from Escherichia coli was measured. This effect permitted the determination of distances from the 2-C position and the phosphorus of covalently bound AMP to the two Mn(II) binding sites, n1 and n2. Binding of Mn(II) to the n1 site converts an inactive apo-enzyme to its active form, while the metal ion bound at n2 occupies the metal-nucleotide substrate site. The distances from Mn(II) at the n1 and n2 sites to phosphorus are ∼10 and ∼7 Å and to the 2-C position of the adenine ring are ∼12 and ∼11 Å, respectively. The fluorescence energy transfer method was used to determine distances between Co(II) at n1 and n2 and the adenylyl site. For this experiment the enzyme was adenylylated with ε-ATP. The distances between ε-adenine and Co(II) at n1 and n2 are ∼13 and ∼11 Å, respectively. Quantitation of the paramagnetic effect due to Co(II) on the 31P nuclear magnetic resonance signal yielded values of 8 and 6 Å for the distances between the phosphorus of the covalently bound AMP and the n1 and n2 sites, respectively. The results reveal that the covalent modification site is very close to the catalytic center of the enzyme. In this study both nuclear magnetic resonance and fluorescence energy transfer techniques have been used to determine distances between the same set of sites on an enzyme surface. PMID:26053

  8. 31P NMR analysis of intracellular pH of Swiss Mouse 3T3 cells: effects of extracellular Na+ and K+ and mitogenic stimulation.

    PubMed

    Civan, M M; Williams, S R; Gadian, D G; Rozengurt, E

    1986-01-01

    Swiss mouse 3T3 cells grown on microcarrier beads were superfused with electrolyte solution during continuous NMR analysis. Conventional 31P and 19F probes of intracellular pH (pHc) were found to be impracticable. Cells were therefore superfused with 1 to 4 mM 2-deoxyglucose, producing a large intracellular, pH-sensitive signal of 2-deoxyglucose phosphate (2DGP). The intracellular incorporation of 2DGP inhibited the Embden-Meyerhof pathway. However, intracellular ATP was at least in part retained and the cellular responsivity to changes in extracellular ionic composition and to the application of growth factors proved intact. Transient replacement of external Na+ with choline or K+ reversibly acidified the intracellular fluids. Quiescent cells and mitogenically stimulated cells displayed the same dependence of shifts in pHc on external Na+ concentration (CoNa). PHc also depended on intracellular Na+ concentration (CcNa). Increasing ccNa by withdrawing external K+ (thereby inhibiting the Na,K-pump) caused reversible intracellular acidification; subsequently reducing CoNa produced a larger acid shift in pHc than with external K+ present. Comparison of separate preparations indicated that pHc was higher in stimulated than in quiescent cells. Transient administration of mitogens also reversibly alkalinized quiescent cells studied continuously. This study documents the feasibility of monitoring pHc of Swiss mouse 3T3 cells using 31P NMR analysis of 2DGP. The results support the concept of a Na/H antiport operative in these cells, both in quiescence and after mitogenic stimulation. The data document by an independent technique that cytoplasmic alkalinization is an early event in mitogenesis, and that full activity of the Embden-Meyerhof pathway is not required for the expression of this event. PMID:3543375

  9. Adenosine triphosphate infusion increases liver energy status in advanced lung cancer patients: an in vivo 31P magnetic resonance spectroscopy study.

    PubMed

    Leij-Halfwerk, Susanne; Agteresch, Hendrik J; Sijens, Paul E; Dagnelie, Pieter C

    2002-02-01

    We recently observed inhibition of weight loss in patients with advanced nonsmall-cell lung cancer after intravenous infusion of ATP. Because liver ATP levels were found to be decreased in lung cancer patients with weight loss, the present 31P magnetic resonance spectroscopy (MRS) study was aimed at investigating whether ATP infusion restores liver energy status in these patients. Nine patients with advanced nonsmall-cell lung cancer (stage IIIB/IV) were studied 1 week before (baseline) and at 22 to 24 hours of continuous ATP infusion (37-75 microg/kg/min). Localized hepatic 31P MR spectra (repetition time 15 seconds), obtained in the overnight-fasted state, were analyzed for ATP and P(i) content. Ten healthy subjects (without ATP infusion) served as control. Liver ATP levels in lung cancer patients increased from 8.8 +/- 0.7% (relative to total MR-detectable phosphate; mean +/- SE) at baseline to 12.2 +/- 0.9% during ATP infusion (P <.05), i.e., a level similar to that in healthy subjects (11.9 +/- 0.9%). The increase in ATP level during ATP infusion was most prominent in patients with > or = 5% weight loss (baseline: 7.9 +/- 0.7%, during ATP infusion: 12.8 +/- 1.0%, P < 0.01). In conclusion, ATP infusion restores hepatic energy levels in patients with advanced lung cancer, especially in weight-losing patients. These changes may contribute to the previously reported beneficial effects of ATP infusion on the nutritional status of lung cancer patients. PMID:11826418

  10. 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