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Sample records for 31p nuclear magnetic

  1. /sup 31/P nuclear magnetic resonance study of renal allograft rejection in the rat

    Energy Technology Data Exchange (ETDEWEB)

    Shapiro, J.I.; Haug, C.E.; Shanley, P.F.; Weil, R. III; Chan, L.

    1988-01-01

    Phosphorus (/sup 31/P) nuclear magnetic resonance (NMR) spectroscopy was used to serially evaluate heterotopic renal allograft rejection in the rat. Renal allografts transplanted to the groin of recipient animals were studied using a 1.89 Tesla horizontal bore magnet. The relative intracellular concentrations of phosphorus metabolites such as adenosine triphosphate and inorganic phosphate as well as intracellular pH were determined by /sup 31/P NMR on days 4, 7, 10, and 14 following transplantation across a major histocompatibility mismatch. Recipient rats chosen to be rejectors received no immunosuppression while animals chosen to be nonrejectors received cyclosporine during the first 7 days following transplantation. By day 7, all rejector rats could be distinguished from nonrejector rats by their higher relative concentration of inorganic phosphate and their lower relative concentration of adenosine triphosphate. These NMR findings correlated with histologic findings of renal infarction probably related to vascular rejection in the allografts. /sup 31/P NMR spectroscopy may have application as a noninvasive tool in the differential diagnosis of posttransplantation renal insufficiency.

  2. In vivo 31P nuclear magnetic resonance investigation of tellurite toxicity in Escherichia coli.

    Science.gov (United States)

    Lohmeier-Vogel, Elke M; Ung, Shiela; Turner, Raymond J

    2004-12-01

    Here we compare the physiological state of Escherichia coli exposed to tellurite or selenite by using the noninvasive technique of phosphorus-31 nuclear magnetic resonance (NMR) spectroscopy. We studied glucose-fed Escherichia coli HB101 cells containing either a normal pUC8 plasmid with no tellurite resistance determinants present or the pTWT100 plasmid which contains the resistance determinants tehAB. No differences could be observed in intracellular ATP levels, the presence or absence of a transmembrane pH gradient, or the levels of phosphorylated glycolytic intermediates when resistant cells were studied by 31P NMR in the presence or absence of tellurite. In the sensitive strain, we observed that the transmembrane pH gradient was dissipated and intracellular ATP levels were rapidly depleted upon exposure to tellurite. Only the level of phosphorylated glycolytic intermediates remained the same as observed with resistant cells. Upon exposure to selenite, no differences could be observed by 31P NMR between resistant and sensitive strains, suggesting that the routes for selenite and tellurite reduction within the cells differ significantly, since only tellurite is able to collapse the transmembrane pH gradient and lower ATP levels in sensitive cells. The presence of the resistance determinant tehAB, by an as yet unidentified detoxification event, protects the cells from uncoupling by tellurite.

  3. Phytate Hydrolysis in Rat Gastrointestinal Tracts, as Observed by 31P Fourier Transform Nuclear Magnetic Resonance Spectroscopy

    OpenAIRE

    Wise, Alan; Richards, Colin P.; Trimble, Mary L.

    1983-01-01

    Phytate hydrolysis was followed through rat gastrointestinal tracts by 31P nuclear magnetic resonance spectroscopy. No phytate hydrolysis products were detected in the diet, stomach, or small intestine. It was concluded that cecal bacteria were responsible for phytate hydrolysis, which continued in the colon and fecal pellet.

  4. Phospholipid composition and organization of cytochrome c oxidase preparations as determined by 31P-nuclear magnetic resonance.

    Science.gov (United States)

    Seelig, A; Seelig, J

    1985-05-14

    The molecular organization as well as the composition of the phospholipids in cytochrome c oxidase preparations (bovine heart) were investigated by 31P-nuclear magnetic resonance. In the so-called 'lipid-rich' preparation the lipids were found to form a fluid bilayer around the enzyme since the 31P-NMR spectrum was characteristic of a fast, axially symmetric motion of the phosphate groups with a chemical shift anisotropy of delta sigma = -45 ppm. In contrast, the 'lipid-depleted' cytochrome c oxidase gave rise to a broader spectrum where the motion of the phospholipids was no longer axially symmetric. Nevertheless, the total width of the spectrum was still considerably narrower than observed for immobilized phospholipids in solid crystals. Both enzyme preparations were dissolved in 1% detergent solution and used for high-resolution 31P-NMR spectroscopy. Narrow lines of about 20 Hz linewidth were obtained for both types of enzyme preparations, and well-resolved resonances could be assigned to cardiolipin, phosphatidylethanolamin and phosphatidylcholine. The major differences between lipid-rich and lipid-depleted cytochrome c oxidase were the absolute amount of phospholipid associated with the protein and the relative contribution of the individual lipid classes to the 31P-NMR spectrum. For lipid-rich cytochrome c oxidase about 130 molecules phospholipid were bound per enzyme (approx. 11 cardiolipins, 54 phosphatidylethanolamines and 64 phosphatidylcholines). For lipid-depleted cytochrome c oxidase only 6-18 lipids were bound per enzyme (1 or 2 cardiolipins, 3-8 phosphatidylethanolamines and 2-8 phosphatidylcholines). In contrast to earlier suggestions that cardiolipin is the only remaining lipid in lipid-depleted cytochrome c oxidase, the 31P-NMR studies demonstrate that all three lipids remain associated with the protein.

  5. Simultaneous electromyography and 31P nuclear magnetic resonance spectroscopy--with application to muscle fatigue

    DEFF Research Database (Denmark)

    Vestergaard-Poulsen, P; Thomsen, C; Sinkjaer, T;

    1992-01-01

    The electromyogram (EMG) is often used to study human muscle fatigue, but the changes in the electromyographic signals during muscle contraction are not well understood in relation to muscle metabolism. The 31P NMR spectroscopy is a semi-quantitative non-invasive method for studying the metabolic...... changes in human muscle. The aim of this study was to develop a method by which EMG and NMR spectroscopy measurements could be performed simultaneously. All measurements were performed in a whole body 1.5 Tesla NMR scanner. A calf muscle ergometer, designed for use in a whole body NMR scanner, was used....... The subject had the left foot strapped to the ergometer. The anterior tibial EMG was recorded by bipolar surface electrodes. A surface coil was strapped to the anterior tibial muscle next to the EMG electrodes. Simultaneous measurements of surface EMG and surface coil 31P NMR spectroscopy were performed...

  6. Blood flow and muscle bio-energetics by 31P-nuclear magnetic resonance after local cold acclimation.

    Science.gov (United States)

    Savourey, G; Clerc, L; Vallerand, A L; Leftheriotis, G; Mehier, H; Bittel, J H

    1992-01-01

    To clarify the origin of local cold adaptation and to define precisely its influence on muscle bio-energetics during local exercise, five subjects were subjected to repeated 5 degrees C cold water immersion of the right hand and forearm. The first aim of our investigation was therefore carried out by measuring local skin temperatures and peripheral blood flow during a cold hand test (5 degrees C, 5 min) followed by a 10-min recovery period. The 31P by nuclear magnetic resonance (31PNMR) muscle bio-energetic changes, indicating possible heat production changes, were measured during the recovery period. The second aim of our investigation was carried out by measuring 31PNMR muscle bioenergetics during handgrip exercise (10% of the maximal voluntary contraction for 5 min followed by a 10-min recovery period) performed both at a comfortable ambient temperature (22 degrees C; E) and after a cold hand test (EC), before and after local cold adaptation. Local cold adaptation, confirmed by warmer skin temperatures of the extremities (+30%, P less than 0.05), was related more to an increased peripheral blood flow, as shown by the smaller decrease in systolic peak [-245 (SEM 30) Hz vs -382 (SEM 95) Hz, P less than 0.05] than to a change in local heat production, because muscle bioenergetics did not vary. Acute local cold immersion decreased the inorganic phosphate:phosphocreatine (PC) ratio during EC compared to E [+0.006 (SEM 0.010) vs +0.078 (SEM 0.002) before acclimation and +0.029 (SEM 0.002) vs +0.090 (SEM 0.002) after acclimation respectively, P less than 0.05] without significant change in the PC:beta-adenosine triphosphate ratio and pH. Local adaptation did not modify these results statistically. The recovery of PC during E increased after acclimation [9.0 (SEM 0.2) min vs 3.0 (SEM 0.4) min, P less than 0.05]. These results suggested that local cold adaptation is related more to peripheral blood flow changes than to increased metabolic heat production in the muscle.

  7. Methylamine metabolism in Hansenula polymorpha: an in vivo 13C and 31P nuclear magnetic resonance study.

    OpenAIRE

    Jones, J G; Bellion, E

    1991-01-01

    Methylamine uptake, oxidation, and assimilation were studied in Hansenula polymorpha, a methylotrophic yeast. The constitutive ammonia transport system was shown to be effective at accumulating methylamine within cells cultured with methylamine or ammonia as a nitrogen source. [13C]methylamine oxidation rates were measured in vivo in methylamine-adapted cells by 13C nuclear magnetic resonance and were found to be lower than its uptake rate into the cells. The 13C label of methylamine was foun...

  8. In Vivo 31P-Nuclear Magnetic Resonance Studies of Glyphosate Uptake, Vacuolar Sequestration, and Tonoplast Pump Activity in Glyphosate-Resistant Horseweed1[W

    Science.gov (United States)

    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

  9. 31P-saturation-transfer nuclear-magnetic-resonance measurements of phosphocreatine turnover in guinea-pig brain slices.

    Science.gov (United States)

    Morris, P G; Feeney, J; Cox, D W; Bachelard, H S

    1985-05-01

    The technique of 31P saturation-transfer n.m.r. was used to determine the forward and the reverse rate constants of creatine phosphotransferase in superfused guinea-pig cerebral tissues in vitro. The calculated forward rate constant of 0.22 +/- 0.03s-1 compared well with a previously reported value for rat brain in vivo [Shoubridge, Briggs & Radda (1982) FEBS Lett. 140, 288-292]. The reverse rate constant was found to be 0.55 +/- 0.10s-1. 3. By using concentrations of ATP and phosphocreatine estimated previously for this superfused preparation [Cox, Morris, Feeney & Bachelard (1983) Biochem. J. 212, 365-370], forward and reverse flux rates were calculated to be 0.68 and 0.72 mumol X s-1 X g-1 respectively. The concordance of forward and reverse fluxes contrasts with the situation observed in vitro in other tissues, and suggests that the creatine phosphotransferase reaction is at equilibrium under the conditions used here. 4. Lowering the concentration of glucose in the superfusing medium from 10mM to 0.5mM had no significant effect on phosphocreatine concentration or on the forward (ATP-generating) flux through creatine phosphotransferase. The results indicate that a normal phosphocreatine content in the presence of lowered glucose availability is reflected by an unchanged turnover rate.

  10. 31P nuclear magnetic resonance in vivo spectroscopy of the metabolic changes induced in the awake rat brain during KCN intoxication and its reversal by hydroxocobalamine.

    Science.gov (United States)

    Benabid, A L; Decorps, M; Remy, C; Le Bas, J F; Confort, S; Leviel, J L

    1987-03-01

    Radiofrequency surface coils were chronically implanted in rats, which were subsequently subjected to 31P nuclear magnetic resonance (NMR) investigations at 4.7 T. The implanted coil allowed study of the animals without need for anesthesia, which is a prerequisite for studies of normal brain metabolism. The animals may be kept in the NMR probe for several hours. During subsequent experiments, they may be placed in the same position, therefore allowing follow-up studies for periods as long as 2 months. This method has been used in the study of sublethal KCN intoxication. KCN, a cytochrome c oxidase inhibitor, induces a blockade of cell respiratory processes, which is reflected, in a dose-dependent manner, by a decrease in phosphocreatine content and pH and an increase in inorganic phosphate content, whereas ATP levels remain constant until high doses of KCN (6 mg/kg i.p.) are reached. 31P NMR allows the time course of these metabolic changes to be followed. For high KCN doses, a new peak, termed X, is observed, which is interpreted as being due to a pool of inorganic phosphate at very low pH (5.65), corresponding to a subset of cells that did not survive KCN injury. Hydroxocobalamine, a specific antidote of KCN, suppresses the metabolic changes due to 6 mg/kg of KCN.

  11. Effects of depleting ionic strength on (31)P nuclear magnetic resonance spectra of micellar casein during membrane separation and diafiltration of skim milk.

    Science.gov (United States)

    Boiani, Mattia; McLoughlin, Padraig; Auty, Mark A E; FitzGerald, Richard J; Kelly, Phil M

    2017-09-01

    Membrane separation processes used in the concentration and isolation of micellar casein-based milk proteins from skim milk rely on extensive permeation of its soluble serum constituents, especially lactose and minerals. Whereas extensive literature exists on how these processes influence the gross composition of milk proteins, we have little understanding of the effects of such ionic depletion on the core structural unit of micellar casein [i.e., the casein phosphate nanocluster (CPN)]. The (31)P nuclear magnetic resonance (NMR) is an analytical technique that is capable of identifying soluble and organic forms of phosphate in milk. Thus, our objective was to investigate changes to the (31)P NMR spectra of skim milk during microfiltration (MF) and diafiltration (DF) by tracking movements in different species of phosphate. In particular, we examined the peak at 1.11 ppm corresponding to inorganic phosphate in the serum, as well as the low-intensity broad signal between 1.5 and 3.0 ppm attributed to casein-associated phosphate in the retentate. The MF concentration and DF using water caused a shift in the relevant (31)P NMR peak that could be minimized if orthophosphate was added to the DF water. However, this did not resolve the simultaneous change in retentate pH and increased solubilization of micellar casein protein. The addition of calcium in combination with orthophosphate prevented micellar casein solubilization and simultaneously contributed to preservation of the CPN structure, except for overcorrection of retentate pH in the acidic direction. A more complex DF solution, involving a combination of phosphate, calcium, and citrate, succeeded in both CPN and micellar casein structure preservation while maintaining retentate pH in the region of the original milk pH. The combination of (31)P NMR as an analytical technique and experimental probe during MF/DF processes provided useful insights into changes occurring to CPN while retaining the micellar state of

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

    Science.gov (United States)

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

    2017-04-01

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

  13. Ab Initio Calculation of Nuclear Magnetic Resonance Chemical Shift Anisotropy Tensors 1. Influence of Basis Set on the Calculation of 31P Chemical Shifts

    Energy Technology Data Exchange (ETDEWEB)

    Alam, T.M.

    1998-09-01

    The influence of changes in the contracted Gaussian basis set used for ab initio calculations of nuclear magnetic resonance (NMR) phosphorous chemical shift anisotropy (CSA) tensors was investigated. The isotropic chemical shitl and chemical shift anisotropy were found to converge with increasing complexity of the basis set at the Hartree-Fock @IF) level. The addition of d polarization function on the phosphorous nucIei was found to have a major impact of the calculated chemical shi~ but diminished with increasing number of polarization fimctions. At least 2 d polarization fimctions are required for accurate calculations of the isotropic phosphorous chemical shift. The introduction of density fictional theory (DFT) techniques through tie use of hybrid B3LYP methods for the calculation of the phosphorous chemical shift tensor resulted in a poorer estimation of the NMR values, even though DFT techniques result in improved energy and force constant calculations. The convergence of the W parametem with increasing basis set complexity was also observed for the DFT calculations, but produced results with consistent large deviations from experiment. The use of a HF 6-31 l++G(242p) basis set represents a good compromise between accuracy of the simulation and the complexity of the calculation for future ab initio calculations of 31P NMR parameters in larger complexes.

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

    Science.gov (United States)

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

    2008-02-01

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

  15. Ascorbic acid prolongs the viability and stability of isolated perfused lungs: A mechanistic study using 31P and hyperpolarized 13C nuclear magnetic resonance.

    Science.gov (United States)

    Shaghaghi, Hoora; Kadlecek, Stephen; Siddiqui, Sarmad; Pourfathi, Mehrdad; Hamedani, Hooman; Clapp, Justin; Profka, Harrilla; Rizi, Rahim

    2015-12-01

    Ex vivo lung perfusion (EVLP) has recently shown promise as a means of more accurately gauging the health of lung grafts and improving graft performance post-transplant. However, reperfusion of ischemic lung promotes the depletion of high-energy compounds and a progressive loss of normal mitochondrial function, and it remains unclear how and to what extent the EVLP approach contributes to this metabolic decline. Although ascorbate has been used to mitigate the effects of ischemia-reperfusion injury, the nature of its effects during EVLP are also not clear. To address these uncertainties, this study monitored the energy status of lungs during EVLP and after the administration of ascorbate using (31)P and hyperpolarized (13)C NMR (nuclear magnetic resonance). Our experiments demonstrated that the oxidative phosphorylation capacity and pyruvate dehydrogenase flux of lungs decline during ex vivo perfusion. The addition of ascorbate to the perfusate prolonged lung viability by 80% and increased the hyperpolarized (13)C bicarbonate signal by a factor of 2.7. The effect of ascorbate is apparently due not to its antioxidant quality but rather to its ability to energize cellular respiration given that it increased the lung's energy charge significantly, whereas other antioxidants (glutathione and α-lipoic acid) did not alter energy metabolism. During ascorbate administration, inhibition of mitochondrial complex I with rotenone depressed energy charge and shifted the metabolic state of the lung toward glycolysis; reenergizing the electron transport chain with TMPD (N,N,N',N'-tetramethyl-p-phenylenediamine) recovered metabolic activity. This indicates that ascorbate slows the decline of the ex vivo perfused lung's mitochondrial activity through an independent interaction with the electron transport chain complexes.

  16. Local anesthetics: interaction with human erythrocyte membranes as studied by {sup 1}H and {sup 31}P nuclear magnetic resonance; Anestesicos locais: interacao com membranas de eritrocitos de sangue humano, estudada por ressonancia magnetica nuclear de {sup 1}H e {sup 31}P

    Energy Technology Data Exchange (ETDEWEB)

    Fraceto, Leonardo Fernandes; Paula, Eneida de [Universidade Estadual de Campinas, SP (Brazil). Inst. de Biologia. Dept. de Bioquimica]. E-mail: depaula@unicamp.br

    2004-02-01

    The literature carries many theories about the mechanism of action of local anesthetics (LA). We can highlight those focusing the direct effect of LA on the sodium channel protein and the ones that consider the interaction of anesthetic molecules with the lipid membrane phase. The interaction between local anesthetics and human erythrocyte membranes has been studied by {sup 1}H and {sup 31}P nuclear magnetic resonance spectroscopy. It was found that lidocaine (LDC) and benzocaine (BZC) bind to the membranes, increase the mobility of the protons of the phospholipids acyl chains, and decrease the mobility and/or change the structure of the polar head groups. The results indicate that lidocaine molecules are inserted across the polar and liquid interface of the membrane, establishing both electrostatic (charged form) and hydrophobic (neutral form) interactions. Benzocaine locates itself a little deeper in the bilayer, between the interfacial glycerol region and the hydrophobic core. These changes in mobility or conformation of membrane lipids could affect the Na{sup +}-channel protein insertion in the bilayer, stabilizing it in the inactivated state, thus causing anesthesia. (author)

  17. Energy metabolism during microsurgical transfer of human skeletal muscle assessed by high-pressure liquid chromatography and by 31P-nuclear magnetic resonance.

    Science.gov (United States)

    Lundberg, Jonas; Elander, Anna; Rakotonirainy, Olivier; Zetterlund, Therese; Fogdestam, Ingemar; Soussi, Bassam

    2002-01-01

    The effect of ischaemia and reperfusion on human skeletal muscle was studied during free vascularised muscle transfer. Muscle biopsy specimens were taken from patients having microsurgical muscle transfer, 18 cases (17 patients; 12 men, 5 women). The biopsies were taken three times: before transfer of the muscle (control), at maximum ischaemic time, and one hour after revascularisation. The biopsy specimens were analysed for purine nucleotides, by high-pressure liquid chromatography (HPLC), and by nuclear magnetic resonance (NMR) at 500 MHz. Phosphocreatine (PCr) recovered only partially (79%) and adenosine triphosphate (ATP) did not differ significantly from normal control after revascularisation and a mean ischaemic time of 114 minutes. NMR measurements showed an accumulation of glucose-6-phosphate (G-6-P) during the ischaemic period, indicating anaerobic metabolism. After three hours of ischaemia and one hour of reperfusion the PCr recovery was less than 60% (r = 0.7). The results confirm those of previous animal studies, which set three hours normothermic ischaemia as a safe limit for tissue preservation when transferring skeletal muscle. Longer ischaemic times may cause serious postoperative healing problems and reduced muscle function.

  18. 31P magnetic resonance spectroscopy of skeletal muscle in patients with fibromyalgia

    DEFF Research Database (Denmark)

    Jacobsen, Søren; Jensen, K E; Thomsen, C

    1992-01-01

    phosphate (Pi/PCr) and pH were calculated from the collected 31P NMR spectra. Resting values of Pi/PCr were normal in the patients. Patients delivered only 49% of the muscle power of the controls (p = 0.005). Patients and controls had similar rates of Pi/PCr and pH changes during work and recovery......31Phosphorous nuclear magnetic resonance (31P NMR) spectroscopy of painful calf muscle was performed in 12 patients with fibromyalgia (FS) and 7 healthy subjects during rest, aerobic and anaerobic exercising conditions, and postexercise recovery. Ratios of inorganic phosphate and creatinine...

  19. T(1) measurement of (31)P metabolites at rest and during steady-state dynamic exercise using a clinical nuclear magnetic resonance scanner.

    Science.gov (United States)

    Cettolo, V; Piorico, C; Francescato, M P

    2006-03-01

    This article illustrates some problems and possible solutions to determine the apparent spin-lattice relaxation time (T(1)) of the muscular (31)P metabolites at rest and during dynamic steady-state exercise using a clinical 1.5 T NMR scanner and a surface coil. T(1) was first estimated on a phosphates solution (phantom) using four different acquisition protocols, all based on the multiple-point "progressive saturation" method, and by fitting each data set with two different mathematical models. Subsequently, two of the four protocols and both models were used to estimate T(1) both at rest and during exercise on the calf muscles of 10 healthy volunteers. Experimental results obtained on the phantom showed that T(1) is greatly affected by the longest nominal explored repetition time (P<0.001) and by the mathematical model (P<0.001), ranging from 0.65+/-0.10 to 8.4+/-0.8 s. The two acquisition protocols applied on volunteers yielded significantly different T(1) (P<0.001), which were also rather different from the literature values for the same metabolites. Nevertheless, independently of the acquisition protocol and/or the fitting procedure, T(1) of all muscular phosphagens did not change statistically from rest to steady-state aerobic exercise.

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

    Science.gov (United States)

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

    2012-02-01

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

  1. 31P NMR first spectral moment study of the partial magnetic orientation of phospholipid membranes.

    Science.gov (United States)

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

    1999-01-01

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

  2. Comparing localized and nonlocalized dynamic (31) P magnetic resonance spectroscopy in exercising muscle at 7T

    NARCIS (Netherlands)

    Meyerspeer, M.; Robinson, S.; Nabuurs, C.I.H.C.; Scheenen, T.W.; Schoisengeier, A.; Unger, E.; Kemp, G.J.; Moser, E.

    2012-01-01

    By improving spatial and anatomical specificity, localized spectroscopy can enhance the power and accuracy of the quantitative analysis of cellular metabolism and bioenergetics. Localized and nonlocalized dynamic (31) P magnetic resonance spectroscopy using a surface coil was compared during aerobic

  3. Comparing localized and nonlocalized dynamic (31) P magnetic resonance spectroscopy in exercising muscle at 7T

    NARCIS (Netherlands)

    Meyerspeer, M.; Robinson, S.; Nabuurs, C.I.H.C.; Scheenen, T.W.; Schoisengeier, A.; Unger, E.; Kemp, G.J.; Moser, E.

    2012-01-01

    By improving spatial and anatomical specificity, localized spectroscopy can enhance the power and accuracy of the quantitative analysis of cellular metabolism and bioenergetics. Localized and nonlocalized dynamic (31) P magnetic resonance spectroscopy using a surface coil was compared during aerobic

  4. Hyperpolarization of 29Si by Resonant Nuclear Spin Transfer from Optically Hyperpolarized 31P Donors

    Science.gov (United States)

    Dluhy, Phillip; Salvail, Jeff; Saeedi, Kamyar; Thewalt, Mike; Simons, Stephanie

    2014-03-01

    Recent developments in nanomedicine have allowed nanoparticles of silicon containing hyperpolarized 29Si to be imaged in vivo using magnetic resonance imaging. The extremely long relaxation times and isotropy of the Si lattice make polarized 29Si isotopes ideal for these sorts of imaging methods. However, one of the major difficulties standing in the path of widespread adoption of these techniques is the slow rate at which the 29Si is hyperpolarized and the limited maximum hyperpolarization achievable. In this talk, I will describe an effective method for hyperpolarization of the 29Si isotopes using resonant optical pumping of the donor bound exciton transitions to polarize the 31P donor nuclei, and a choice of static magnetic field that conserves energy during spin flip flops between donor nuclear and 29Si spins to facilitate diffusion of this polarization. Using this method, we are able to polarize greater than 10% of the 29Si centers in 64 hours without seeing saturation of the 29Si polarization.

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

    Science.gov (United States)

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

    1987-10-24

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

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

    Science.gov (United States)

    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

  7. Repeatability of (31) P MRSI in the human brain at 7 T with and without the nuclear Overhauser effect

    NARCIS (Netherlands)

    Lagemaat, M.W.; Bank, B.L. van de; Sati, P.; Li, S.; Maas, M.C.; Scheenen, T.W.J.

    2016-01-01

    An often-employed strategy to enhance signals in (31) P MRS is the generation of the nuclear Overhauser effect (NOE) by saturation of the water resonance. However, NOE allegedly increases the variability of the (31) P data, because variation is reported in NOE enhancements. This would negate the

  8. Feasibility of Rapid-Sequence {sup 31}P Magnetic Resonance Spectroscopy in Cardiac Patients

    Energy Technology Data Exchange (ETDEWEB)

    Chida, K.; Otani, H.; Saito, H.; Nagasaka, T.; Kagaya, Y.; Kohzuki, M.; Zuguchi, M.; Shirato, K. [Tohoku Univ., School of Health Sciences, Sendai (Japan). Dept. of Radiological Technology

    2005-07-01

    Purpose: To determine the clinical feasibility of rapid-sequence phosphorus-31 magnetic resonance spectroscopy ({sup 31}P -MRS) of the heart with cardiac patients using a 5T clinical MR system. Material and Methods: Twenty cardiac patients, i.e. dilated cardiomyopathy (DCM)3 cases, hypertrophic cardiomyopathy (HCM) 3 cases, hypertensive heart diseases (HHD) 3 cases, and aortic regurgitation (AR) case were examined using rapid cardiac {sup 31}P-MRS. Complete three-dimensional localization was performed using a two-dimensional phosphorus chemical-shift imaging sequence in combination with 30-mm axial slice-selective excitation. The rapid-sequence {sup 31}P-MRS procedure was phase encoded in arrays of 8x8 steps with an average of 4 acquisitions. The total examination time, including proton imaging and shimming, for the rapid cardiac {sup 31}P-MRS procedure, ranged from 0 to 5 min, depending on the heart rate. Student's t test was used to compare creatine phosphate (PCr)/adenosine triphosphate (ATP) ratios from the cardiac patients with those of the control subjects (n{approx_equal}13). Results: The myocardial PCr/ATP ratio obtained by rapid {sup 31}P-MRS was significantly lower (P <0.001) in DCM patients (1.82{+-}0.33, mean{+-}SD), and in patients with global myocardial dysfunction (combined data for 20 patients:.89{+-}0.32) than in normal volunteers (2.96{+-}0.59). These results are similar to previous studies. Conclusion: Rapid-sequence {sup 31}P-MRS may be a valid diagnostic tool for patients with cardiac disease.

  9. Semi-LASER localized dynamic 31P magnetic resonance spectroscopy in exercising muscle at ultra-high magnetic field.

    NARCIS (Netherlands)

    Meyerspeer, M.; Scheenen, T.W.J.; Schmid, A.I.; Mandl, T.; Unger, E.; Moser, E.

    2011-01-01

    Magnetic resonance spectroscopy (MRS) can benefit from increased signal-to-noise ratio (SNR) of high magnetic fields. In this work, the SNR gain of dynamic 31P MRS at 7 T was invested in temporal and spatial resolution. Using conventional slice selective excitation combined with localization by adia

  10. Solid-state nuclear magnetic resonance measurements of HIV fusion peptide 13CO to lipid 31P proximities support similar partially inserted membrane locations of the α helical and β sheet peptide structures.

    Science.gov (United States)

    Gabrys, Charles M; Qiang, Wei; Sun, Yan; Xie, Li; Schmick, Scott D; Weliky, David P

    2013-10-03

    Fusion of the human immunodeficiency virus (HIV) membrane and the host cell membrane is an initial step of infection of the host cell. Fusion is catalyzed by gp41, which is an integral membrane protein of HIV. The fusion peptide (FP) is the ∼25 N-terminal residues of gp41 and is a domain of gp41 that plays a key role in fusion catalysis likely through interaction with the host cell membrane. Much of our understanding of the FP domain has been accomplished with studies of "HFP", i.e., a ∼25-residue peptide composed of the FP sequence but lacking the rest of gp41. HFP catalyzes fusion between membrane vesicles and serves as a model system to understand fusion catalysis. HFP binds to membranes and the membrane location of HFP is likely a significant determinant of fusion catalysis perhaps because the consequent membrane perturbation reduces the fusion activation energy. In the present study, many HFPs were synthesized and differed in the residue position that was (13)CO backbone labeled. Samples were then prepared that each contained a singly (13)CO labeled HFP incorporated into membranes that lacked cholesterol. HFP had distinct molecular populations with either α helical or oligomeric β sheet structure. Proximity between the HFP (13)CO nuclei and (31)P nuclei in the membrane headgroups was probed by solid-state NMR (SSNMR) rotational-echo double-resonance (REDOR) measurements. For many samples, there were distinct (13)CO shifts for the α helical and β sheet structures so that the proximities to (31)P nuclei could be determined for each structure. Data from several differently labeled HFPs were then incorporated into a membrane location model for the particular structure. In addition to the (13)CO labeled residue position, the HFPs also differed in sequence and/or chemical structure. "HFPmn" was a linear peptide that contained the 23 N-terminal residues of gp41. "HFPmn_V2E" contained the V2E mutation that for HIV leads to greatly reduced extent of fusion and

  11. In vivo magnetic resonance imaging and 31P spectroscopy of large human brain tumours at 1.5 tesla

    DEFF Research Database (Denmark)

    Thomsen, C; Jensen, K E; Achten, E

    1988-01-01

    31P MR spectroscopy of human brain tumours is one feature of magnetic resonance imaging. Eight patients with large superficial brain tumours and eight healthy volunteers were examined with 31P spectroscopy using an 8 cm surface coil for volume selection. Seven frequencies were resolved in our spe...

  12. In vivo magnetic resonance imaging and 31P spectroscopy of large human brain tumours at 1.5 tesla

    DEFF Research Database (Denmark)

    Thomsen, C; Jensen, K E; Achten, E;

    1988-01-01

    31P MR spectroscopy of human brain tumours is one feature of magnetic resonance imaging. Eight patients with large superficial brain tumours and eight healthy volunteers were examined with 31P spectroscopy using an 8 cm surface coil for volume selection. Seven frequencies were resolved in our spe...

  13. In vivo magnetic resonance imaging and 31P spectroscopy of large human brain tumours at 1.5 tesla

    DEFF Research Database (Denmark)

    Thomsen, C; Jensen, K E; Achten, E

    1988-01-01

    31P MR spectroscopy of human brain tumours is one feature of magnetic resonance imaging. Eight patients with large superficial brain tumours and eight healthy volunteers were examined with 31P spectroscopy using an 8 cm surface coil for volume selection. Seven frequencies were resolved in our...... and after chemotherapy. The spectra showed considerable changes during chemotherapy. It is concluded that 31P spectroscopy using surface coils is of limited value for tumour characterization, but may add useful information in monitoring the effect of chemotherapy....

  14. Investigation of phosphorous in thin films using the {sup 31}P(α,p){sup 34}S nuclear reaction

    Energy Technology Data Exchange (ETDEWEB)

    Pitthan, E., E-mail: eduardo.pitthan@ufrgs.br [PGMICRO, UFRGS, 91509-900 Porto Alegre, RS (Brazil); Gobbi, A.L. [Laboratório Nacional de Nanotecnologia, 13083-100 Campinas, SP (Brazil); Stedile, F.C. [PGMICRO, UFRGS, 91509-900 Porto Alegre, RS (Brazil); Instituto de Química, UFRGS, 91509-900 Porto Alegre, RS (Brazil)

    2016-03-15

    Phosphorus detection and quantification were obtained, using the {sup 31}P(α,p){sup 34}S nuclear reaction and Rutherford Backscattering Spectrometry, in deposited silicon oxide films containing phosphorus and in carbon substrates implanted with phosphorus. It was possible to determine the total amount of phosphorus using the resonance at 3.640 MeV of the {sup 31}P(α,p){sup 34}S nuclear reaction in samples with phosphorus present in up to 23 nm depth. Phosphorous amounts as low as 4 × 10{sup 14} cm{sup −2} were detected. Results obtained by nuclear reaction were in good agreement with those from RBS measurements. Possible applications of phosphorus deposition routes used in this work are discussed.

  15. Investigation of phosphorous in thin films using the 31P(α,p)34S nuclear reaction

    Science.gov (United States)

    Pitthan, E.; Gobbi, A. L.; Stedile, F. C.

    2016-03-01

    Phosphorus detection and quantification were obtained, using the 31P(α,p)34S nuclear reaction and Rutherford Backscattering Spectrometry, in deposited silicon oxide films containing phosphorus and in carbon substrates implanted with phosphorus. It was possible to determine the total amount of phosphorus using the resonance at 3.640 MeV of the 31P(α,p)34S nuclear reaction in samples with phosphorus present in up to 23 nm depth. Phosphorous amounts as low as 4 × 1014 cm-2 were detected. Results obtained by nuclear reaction were in good agreement with those from RBS measurements. Possible applications of phosphorus deposition routes used in this work are discussed.

  16. In Vivo (31) P magnetic resonance spectroscopic imaging (MRSI) for metabolic profiling of human breast cancer xenografts

    NARCIS (Netherlands)

    Esmaeili, M.; Moestue, S.A.; Hamans, B.C.; Veltien, A.A.; Kristian, A.; Engebraaten, O.; Maelandsmo, G.M.; Gribbestad, I.S.; Bathen, T.F.; Heerschap, A.

    2015-01-01

    To study cancer associated with abnormal metabolism of phospholipids, of which several have been proposed as biomarkers for malignancy or to monitor response to anticancer therapy. We explored 3D (31) P magnetic resonance spectroscopic imaging (MRSI) at high magnetic field for in vivo assessment of

  17. {sup 1}H and {sup 31}P-magnetic resonance spectroscopy of cerebral infarction in rats

    Energy Technology Data Exchange (ETDEWEB)

    Yamamuro, Manabu; Katayama, Yasuo; Igarashi, Hironaka; Terashi, Akiro [Nippon Medical School, Tokyo (Japan)

    1997-04-01

    Magnetic resonance spectroscopy (MRS) allows the noninvasive study of metabolism in vivo. In order to further understand the time course of biochemical changes during cerebral infarction, we performed the MRS study with pathological analysis. The left middle cerebral artery (MCA) was occluded in spontaneously hypertensive male rats (SHR) by the method of Tamura et al. The spectra were obtained from the infarcted hemisphere by placing the surface coils over the left side of the calvarium. {sup 31}P and {sup 1}H-MRS were performed at 3 hours, 24 hours and 7 days after MCA occlusion. Ischemic lesions caused by the left MCA occlusion extended into the parietal lobe and caudate putamen. After 3 hours of ischemia, vacuolated neurophils and shrunken neurons were observed. At 24 hours, these changes were severe. After 7 days, infiltration of monocytes and capillary hyperplasia were seen, and neurons had disappeared. At the acute stage of ischemia the phosphocreatine/inorganic phosphate (PCr/Pi) peak ratio decreased. After 7 days of ischemia, these changes became obscure. The intracellular pH (pHi) decreased after 3 hours of ischemia and recovered almost to the control level at 24 hours post ischemia. Alkalosis was apparent 7 days after ischemia. This alkalosis might be due to increased permeability of the deteriorated blood brain barrier. Although the lactate level was high 24 hours post ischemia, the pHi was almost normal. The N-acetyl-aspartate/creatine ratio decreased significantly from the acute stage of stroke. This decrease correlated with pathological changes. The correlation of the magnetic resonance spectra with the histological results may open aspects for monitoring stroke therapy and a new approach to tissue characterization. (author)

  18. INVIVO 31P MAGNETIC-RESONANCE SPECTROSCOPY (MRS) OF TENDER POINTS IN PATIENTS WITH PRIMARY FIBROMYALGIA SYNDROME

    NARCIS (Netherlands)

    DEBLECOURT, AC; WOLF, RF; VANRIJSWIJK, MH; KAMMAN, RL; KNIPPING, AA; MOOYAART, EL

    1991-01-01

    31P Magnetic Resonance-Spectroscopy was performed at the site of tender points in the trapezius muscle of patients with primary fibromyalgia syndrome. Earlier, in vitro studies have reported changes in the high energy phosphate-metabolism in biopsies taken from tender points of fibromyalgia patients

  19. Semi-LASER localized dynamic 31P magnetic resonance spectroscopy in exercising muscle at ultra-high magnetic field.

    Science.gov (United States)

    Meyerspeer, Martin; Scheenen, Tom; Schmid, Albrecht Ingo; Mandl, Thomas; Unger, Ewald; Moser, Ewald

    2011-05-01

    Magnetic resonance spectroscopy (MRS) can benefit from increased signal-to-noise ratio (SNR) of high magnetic fields. In this work, the SNR gain of dynamic 31P MRS at 7 T was invested in temporal and spatial resolution. Using conventional slice selective excitation combined with localization by adiabatic selective refocusing (semi-LASER) with short echo time (TE = 23 ms), phosphocreatine quantification in a 38 mL voxel inside a single exercising muscle becomes possible from single acquisitions, with SNR = 42 ± 4 in resting human medial gastrocnemius. The method was used to quantify the phosphocreatine time course during 5 min of plantar flexion exercise and recovery with a temporal resolution of 6 s (the chosen repetition time for moderate T1 saturation). Quantification of inorganic phosphate and pH required accumulation of consecutively acquired spectra when (resting) Pi concentrations were low. The localization performance was excellent while keeping the chemical shift displacement acceptably small. The SNR and spectral line widths with and without localization were compared between 3T and 7 T systems in phantoms and in vivo. The results demonstrate that increased sensitivity of ultra-high field can be used to dynamically acquire metabolic information from a clearly defined region in a single exercising muscle while reaching a temporal resolution previously available with MRS in non-localizing studies only. The method may improve the interpretation of dynamic muscle MRS data.

  20. 31P NMR study of magnetic phase transitions of MnP single crystal under 2 GPa pressure

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2008-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Seegmiller, J.E. (John Radcliffe Hospital, Oxford (England) Univ. of California, San Diego (United States)); Dixon, R.M.; Kemp, G.J.; Rajagopalan, B.; Radda, G.K. (John Radcliffe Hospital, Oxford (England)); Angus, P.W. (John Radcliffe Hospital, Oxford (England) Austin Hospital, Heidelburg, Victoria (Australia)); McAlindon, T.E.; Dieppe, P. (Univ. of Bristol (England))

    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.

  3. Biochemical metabolic changes assessed by 31P magnetic resonance spectroscopy after radiation-induced hepatic injury in rabbits

    Institute of Scientific and Technical Information of China (English)

    Ri-Sheng Yu; Liang Hao; Fei Dong; Jian-Shan Mao; Jian-Zhong Sun; Ying Chen; Min Lin; Zhi-Kang Wang; Wen-Hong Ding

    2009-01-01

    AIM:To compare the features of biochemical metabolic changes detected by hepatic phosphorus-31 magnetic resonance spectroscopy (31P MRS) with the liver damage score (LDS) and pathologic changes in rabbits and to investigate the diagnostic value of 31P MRS in acute hepatic radiation injury.METHODS:A total of 30 rabbits received different radiation doses (ranging 5-20 Gy) to establish acute hepatic injury models.Blood biochemical tests,31P MRS and pathological examinations were carried out 24 h after irradiation.The degree of injury was evaluated according to LDS and pathology.Ten healthy rabbits served as controls.The MR examination was performed on a 1.5 T imager using a 1H/31P surface coil by the 2D chemical shift imaging technique.The relative quantities of phosphomonoesters (PME),phosphodiesters (PDE),inorganic phosphate (Pi) and adenosine triphosphate (ATP) were measured.The data were statistically analyzed.RESULTS:(1) Relative quantification of phosphorus metabolites:(a) ATP:there were significant differences (P<0.05) (LDS-groups:control group vs mild group vs moderate group vs severe group,1.83±0.33 vs 1.55±0.24 vs 1.27±0.09 vs 0.98±0.18;pathological groups:control group vs mild group vs moderate group vs severe group,1.83±0.33 vs 1.58±0.25 vs 1.32±0.07 vs 1.02 ± 0.18) of ATP relative quantification among control group,mild injured group,moderate injured group,and severe injured group according to both LDS grading and pathological grading,respectively,and it decreased progressively with the increased degree of injury (r=-0.723,P=0.000).(b) PME and Pi;the relative quantification of PME and Pi decreased significantly in the severe injured group,and the difference between the control group and severe injured group was significant (P<0.05) (PME:LDScontrol group vs LDS-severe group,0.86±0.23 vs 0.58±0.22,P=0.031;pathological control group vs pathological severe group,0.86±0.23 vs 0.60±0.21,P=0.037;Pi:LDS-control group vs LDS-severe group,0.74±0.18 vs

  4. Phosphorus-doped thin silica films characterized by magic-angle spinning nuclear magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Jacobsen, H.J.; Skibsted, J.; Kristensen, Martin

    2001-01-01

    Magic-angle spinning nuclear magnetic resonance spectra of 31P and 29Si have been achieved for a thin silica film doped with only 1.8% 31P and deposited by plasma enhanced chemical vapor deposition on a pure silicon wafer. The observation of a symmetric 31P chemical shift tensor is consistent...

  5. Different early effect of irradiation in brain and small cell lung cancer examined by in vivo 31P-magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Kristjansen, P E; Pedersen, A G; Quistorff, B

    1992-01-01

    Early effects of irradiation were evaluated by non-invasive in vivo 31P-magnetic resonance spectroscopy (31P-MRS) of two small cell lung cancer (SCLC) tumor lines CPH SCCL 54A and 54B, in nude mice. The tumors were originally derived from the same patient and have similar morphology and growth...... characteristics, but a different radiosensitivity. The 54A tumors are twice as radiosensitive as the 54B's. In the present study the tumors were treated with 2.5, 10, and 40 Gy. For comparison, nude mice were given cranial irradiation at the same three doses, and the effect was evaluated by in vivo 31P-MRS...... in ATP/Pi. The differential effect on tumors and brain might be relevant for monitoring irradiation effects by in vivo 31P-MRS in patients with brain metastases....

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

    Science.gov (United States)

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

    2006-12-11

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

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

    Science.gov (United States)

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

    1994-08-01

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

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

    Science.gov (United States)

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

    1999-01-01

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

  9. Different early effect of irradiation in brain and small cell lung cancer examined by in vivo 31P-magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Kristjansen, P E; Pedersen, A G; Quistorff, B

    1992-01-01

    Early effects of irradiation were evaluated by non-invasive in vivo 31P-magnetic resonance spectroscopy (31P-MRS) of two small cell lung cancer (SCLC) tumor lines CPH SCCL 54A and 54B, in nude mice. The tumors were originally derived from the same patient and have similar morphology and growth......-MRS. No effect was observed in brain at any dose level. In contrast, 40 Gy induced a statistically significant reduction in ATP/Pi ratio during the 12-h post-irradiation period. This effect was more pronounced in 54A than in 54B. Some reduction was observed following 10 Gy, whereas 2.5 Gy induced no changes...... in ATP/Pi. The differential effect on tumors and brain might be relevant for monitoring irradiation effects by in vivo 31P-MRS in patients with brain metastases....

  10. Different early effect of irradiation in brain and small cell lung cancer examined in vivo [sup 31]P-magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kristjansen, P.E.G. (Finseninstitutet, Copenhagen (Denmark) Copenhagen University, Panum Institute (Denmark). Department of Biochemistry, NMR-Center, Institute of Pathological Anatomy); Pedersen, A.G. (Finseninstitutet, Copenhagen (Denmark)); Quistorff, B. (Copenhagen University, Panum Institute (Denmark). Department of Biochemistry, NMR-Center); Spang-Thomsen, M. (Copenhagen University (Denmark). Institute of Pathological Anatomy)

    1992-07-01

    Early effects of irradiation were evaluated by non-invasive in vivo [sup 31]P-magnetic resonance spectroscopy ([sup 31]P-MRS) of 2 small cell lung cancer (SCLC) tumor lines CPH SCCL 54A and 54B, in nude mice. The tumors were originally derived from the same patient and have similar morphology and growth characteristics, but a different radiosensitivity. The 54A tumors are twice as radiosensitive as the 54B's. In the present study the tumors were treated with 2.5, 10 and 40 Gy. For comparison, nude mice were given cranial irradiation at the same 3 doses, and the effect was evaluated by in vivo [sup 31]P-MRS. No effect was observed in brain at any dose level. In contrast, 40 Gy induced a statistically significant reduction in ATP/p[sub i] ratio during the 12-h post-irradiation period. This effect was more pronounced in 54A than in 54B. Some reduction was observed following 10 Gy, whereas 2.5 Gy induced no changes in ATP/P[sub i]. The differential effect on tumors and brain might be relevant for monitoring irradiation effects by in vivo [sup 31]P-MRS in patients with brain metastases. (author). 11 refs.; 1 fig.; 2 tabs.

  11. ({sup 1} H, {sup 13} C and {sup 31} P) NMR of phosphonic acid derivatives; Ressonancia magnetica nuclear ({sup 1} H, {sup 13} C, {sup 31} P) de derivados do acido fosfonico

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Valdevino; Costa, Valentim E. Uberti [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Quimica

    1991-12-31

    In the last years the development of phosphates analogues in the medical and agricultural pesticides has being very expressive. {sup 1} H, {sup 13} C and mainly {sup 31} P NMR are used for stereochemical and conformational analysis, and reactivity studies on the compounds resulting from those chemical processes 2 refs., 4 figs., 1 tab.

  12. Improved energy kinetics following high protein diet in McArdle's syndrome. A 31P magnetic resonance spectroscopy study

    DEFF Research Database (Denmark)

    Jensen, K E; Jakobsen, J; Thomsen, C

    1990-01-01

    A patient with McArdle's syndrome was examined using bicycle ergometry and 31P NMR spectroscopy during exercise. The patients working capacity was approximately half the expected capacity of controls. Muscle energy kinetics improved significantly during intravenous glucose infusion and after 6...... weeks of high protein diet. During intravenous infusion of amino acids, no changes in working capacity could be detected. No decrease was seen in intracellular muscle pH during aerobic exercise. A significant decrease in muscle pH during aerobic exercise was detected in all controls....

  13. Localized Semi-LASER Dynamic 31P Magnetic Resonance Spectroscopy of the Soleus During and Following Exercise at 7 T

    CERN Document Server

    Fiedler, Georg B; Schmid, Albrecht I; Goluch, Sigrun; Schewzow, Kiril; Laistler, Elmar; Mirzahosseini, Arash; Niess, Fabian; Unger, Ewald; Wolzt, Michael; Moser, Ewald

    2015-01-01

    Object This study demonstrates the applicability of semi-LASER localized dynamic $^{31}$P MRS to deeper lying areas of the exercising human soleus muscle (SOL). The effect of accurate localization and high temporal resolution on data specificity is investigated. Materials and Methods To achieve high signal-to-noise ratio (SNR) at a temporal resolution of 6 s, a custom-built calf coil array was used at 7T. The kinetics of phosphocreatine (PCr) and intracellular pH were quantified separately in SOL and gastrocnemius medialis (GM) muscle of 9 volunteers, during rest, plantar flexion exercise and recovery. Results The average SNR of PCr at rest was 64$\\pm$15 in SOL (83$\\pm$12 in GM). End exercise PCr depletion in SOL (19$\\pm$9%) was far lower than in GM (74$\\pm$14%). pH in SOL increased rapidly and, in contrast to GM, remained elevated until the end of exercise. Conclusion $^{31}$P MRS in single-shots every 6 s localized in the deeper lying SOL enabled quantification of PCr recovery times at low depletions and of...

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

    Science.gov (United States)

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

    2014-04-01

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

  15. Value of dynamic 31p magnetic resonance spectroscopy technique in in vivo assessment of the skeletal muscle mitochondrial function in type 2 diabetes

    Institute of Scientific and Technical Information of China (English)

    WU Fei-yun; TU Hui-juan; QIN Bin; CHEN Ting; XU Hua-feng; QI Jing; WANG De-hang

    2012-01-01

    Background Phosphorous magnetic resonance spectroscopy (31p-MRS) has been successfully applied to study intracellular membrane compounds and high-energy phosphate metabolism.This study aimed to evaluate the capability of dynamic 31p-MRS for assessing energy metabolism and mitochondrial function in skeletal muscle from type 2 diabetic patients.Methods Dynamic 31p-MRS was performed on 22 patients with type 2 diabetes and 26 healthy volunteers.Spectra were acquired from quadriceps muscle while subjects were in a state of rest,at exercise and during recovery.The peak areas of inorganic phosphate (Pi),phosphocreatine (PCr),and adenosine triphosphate (ATP) were measured.The concentration of adenosine diphosphate (ADP) and the intracellular pH value were calculated from the biochemistry reaction equilibrium.The time constant and recovery rates of Pi,PCr,and ADP were analyzed using exponential curve fitting.Results As compared to healthy controls,type 2 diabetes patients had significantly lower skeletal muscle concentrations of Pi,PCr and β-ATP,and higher levels of ADP and Pi/PCr.During exercise,diabetics experienced a significant Pi peak increase and PCr peak decrease,and once the exercise was completed both Pi and PCr peaks returned to resting levels.Quantitatively,the mean recovery rates of Pi and PCr in diabetes patients were (10.74±1.26) mmol/s and (4.74±2.36) mmol/s,respectively,which was significantly higher than in controls.Conclusions Non-invasive quantitative 31P-MRS is able to detect energy metabolism inefficiency and mitochondrial function impairment in skeletal muscle of type 2 diabetics.

  16. {sup 31}P magnetic resonance spectroscopy to measure in vivo cardiac energetics in normal myocardium and hypertrophic cardiomyopathy: Experiences at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Shivu, Ganesh Nallur [Department of Cardiovascular Medicine, University of Birmingham, Vincent Drive, Edgbaston, Birmingham B15 2TT (United Kingdom)], E-mail: drgani23@gmail.com; Abozguia, Khalid; Phan, Thanh Trung; Ahmed, Ibrar [Department of Cardiovascular Medicine, University of Birmingham, Vincent Drive, Edgbaston, Birmingham B15 2TT (United Kingdom); Henning, Anke [Institute for Biomedical Engineering, University and ETH Zurich, Gloriastrasse 35, CH-8092, Zurich CH ETZ F97 (Switzerland); Frenneaux, Michael [Department of Cardiovascular Medicine, University of Birmingham, Vincent Drive, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2010-02-15

    Background: {sup 31}P magnetic resonance spectroscopy (MRS) allows measurement of in vivo high-energy phosphate kinetics in the myocardium. While traditionally {sup 31}P cardiac spectroscopy is performed at 1.5 T, cardiac MRS at higher field strength can theoretically increase signal to noise ratio (SNR) and spectral resolution therefore improving sensitivity and specificity of the cardiac spectra. The reproducibility and feasibility of performing cardiac spectroscopy at 3 T is presented here in this study in healthy volunteers and patients with hypertrophic cardiomyopathy. Methods: Cardiac spectroscopy was performed using a Phillips 3T Achieva scanner in 37 healthy volunteers and 26 patients with hypertrophic cardiomyopathy (HCM) to test the feasibility of the protocol. To test the reproducibility a single volunteer was scanned eight times on separate occasions. A single voxel {sup 31}P MRS was performed using Image Selected In vivo Spectroscopy (ISIS) volume localization. Results: The mean phosphocreatine/adenosine triphosphate (PCr/ATP) ratio of the eight measurements performed on one individual was 2.11 {+-} 0.25. Bland Altman plots showed a variance of 12% in the measurement of PCr/ATP ratios. The PCr/ATP ratio was significantly reduced in HCM patients compared to controls, 1.42 {+-} 0.51 and 2.11 {+-} 0.57, respectively, P < 0.0001. (All results are expressed as mean {+-} standard deviation). Conclusions: Here we demonstrate that cardiac {sup 31}P MRS at 3 T is a reliable method of measuring in vivo high-energy phosphate kinetics in the myocardium for clinical studies and diagnostics. Based on our data an impairment of cardiac energetic state in patients with hypertrophic cardiomyopathy is indisputable.

  17. Separation of advanced from mild fibrosis in diffuse liver disease using {sup 31}P magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Noren, Bengt [Department of Radiology, Linkoeping University, SE-581 85 Linkoeping (Sweden); Dahlqvist, Olof [Department of Radiation Physics, Linkoeping University, SE-581 85 Linkoeping (Sweden); Center for Medical Image Science and Visualization (CMIV), Linkoeping University, SE-581 85 Linkoeping (Sweden); Lundberg, Peter [Department of Radiology, Linkoeping University, SE-581 85 Linkoeping (Sweden); Department of Radiation Physics, Linkoeping University, SE-581 85 Linkoeping (Sweden); Center for Medical Image Science and Visualization (CMIV), Linkoeping University, SE-581 85 Linkoeping (Sweden)], E-mail: Peter.Lundberg@imv.liu.se; Almer, Sven [Department of Gastroenterology and Hepatology, Linkoeping University, SE-581 85 Linkoeping (Sweden); Kechagias, Stergios [Department of Internal Medicine, Linkoeping University, SE-581 85 Linkoeping (Sweden); Ekstedt, Mattias [Department of Gastroenterology and Hepatology, Linkoeping University, SE-581 85 Linkoeping (Sweden); Franzen, Lennart [Medilab, SE-183 53 Taeby Sweden (Sweden); Wirell, Staffan [Department of Radiology, Linkoeping University, SE-581 85 Linkoeping (Sweden); Smedby, Orjan [Department of Radiology, Linkoeping University, SE-581 85 Linkoeping (Sweden); Center for Medical Image Science and Visualization (CMIV), Linkoeping University, SE-581 85 Linkoeping (Sweden)

    2008-05-15

    {sup 31}P-MRS using DRESS was used to compare absolute liver metabolite concentrations (PME, Pi, PDE, {gamma}ATP, {alpha}ATP, {beta}ATP) in two distinct groups of patients with chronic diffuse liver disorders, one group with steatosis (NAFLD) and none to moderate inflammation (n = 13), and one group with severe fibrosis or cirrhosis (n = 16). All patients underwent liver biopsy and extensive biochemical evaluation. A control group (n = 13) was also included. Absolute concentrations and the anabolic charge, AC = {l_brace}PME{r_brace}/({l_brace}PME{r_brace} + {l_brace}PDE{r_brace}), were calculated. Comparing the control and cirrhosis groups, lower concentrations of PDE (p = 0.025) and a higher AC (p < 0.001) were found in the cirrhosis group. Also compared to the NAFLD group, the cirrhosis group had lower concentrations of PDE (p = 0.01) and a higher AC (p = 0.009). No significant differences were found between the control and NAFLD group. When the MRS findings were related to the fibrosis stage obtained at biopsy, there were significant differences in PDE between stage F0-1 and stage F4 and in AC between stage F0-1 and stage F2-3. Using a PDE concentration of 10.5 mM as a cut-off value to discriminate between mild, F0-2, and advanced, F3-4, fibrosis the sensitivity and specificity were 81% and 69%, respectively. An AC cut-off value of 0.27 showed a sensitivity of 93% and a specificity of 54%. In conclusion, the results suggest that PDE is a marker of liver fibrosis, and that AC is a potentially clinically useful parameter in discriminating mild fibrosis from advanced.

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

    Science.gov (United States)

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

    2006-04-01

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

  19. Simultaneous electromyography and 31P nuclear magnetic resonance spectroscopy--with application to muscle fatigue

    DEFF Research Database (Denmark)

    Vestergaard-Poulsen, P; Thomsen, C; Sinkjaer, T

    1992-01-01

    changes in human muscle. The aim of this study was to develop a method by which EMG and NMR spectroscopy measurements could be performed simultaneously. All measurements were performed in a whole body 1.5 Tesla NMR scanner. A calf muscle ergometer, designed for use in a whole body NMR scanner, was used...

  20. Bioenergy recovery phenomenon in the myocardium following ischemia and factors contributing to the recovery studied by /sup 31/P magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yoshiyama, Minoru

    1988-10-01

    Metabolism in ischemic and post-ischemic myocardium was studied by the use of /sup 31/P magnetic resonance spectroscopy (/sup 31/P-MRS) to identify factors that cause recovery of ATP levels in post-ischemic hearts. Perfused guinea-pig hearts were treated to 30 or 60 min of ischemia and reperfused by one of three perfusates, one with 200 ..mu..M adenosine (ADO30 for 30 min ischemia), one with 200 ..mu..M inosine (INO30 for 30 min ischemia, and INO60 for 60 min ischemia), and the third without adenine uncleoside. After 4 hours of reperfusion, ATP levels in INO30 were 95.5% of preischemic level, and in ADO30, 113.5% at 4 hours. However, ATP levels in the control increased only up to 70.2%. ATP levels in INO60 improved to 73.4% after 4 hours and then became stable. Left ventricular maximal positive dp/dt also recovered to 82.4% (control, 43.1%) after 6 hours. In an in vivo study, ATP levels depressed after ischemia did not recover after 4 hours of reperfusion. However, ATP levels recovered from 70.2% to 86.6% after the administration of adenosine into the left ventricle (0.1 mmol of adenosine per hour) for 2 hours. Administration of inosine or adenosine to the post-ischemic heart should be useful to improve the myocardial metabolism and cardiac function.

  1. Gray matter-specific changes in brain bioenergetics after acute sleep deprivation: a 31P magnetic resonance spectroscopy study at 4 Tesla.

    Science.gov (United States)

    Plante, David T; Trksak, George H; Jensen, J Eric; Penetar, David M; Ravichandran, Caitlin; Riedner, Brady A; Tartarini, Wendy L; Dorsey, Cynthia M; Renshaw, Perry F; Lukas, Scott E; Harper, David G

    2014-12-01

    A principal function of sleep may be restoration of brain energy metabolism caused by the energetic demands of wakefulness. Because energetic demands in the brain are greater in gray than white matter, this study used linear mixed-effects models to examine tissue-type specific changes in high-energy phosphates derived using 31P magnetic resonance spectroscopy (MRS) after sleep deprivation and recovery sleep. Experimental laboratory study. Outpatient neuroimaging center at a private psychiatric hospital. A total of 32 MRS scans performed in eight healthy individuals (mean age 35 y; range 23-51 y). Phosphocreatine (PCr) and β-nucleoside triphosphate (NTP) were measured using 31P MRS three dimensional-chemical shift imaging at high field (4 Tesla) after a baseline night of sleep, acute sleep deprivation (SD), and 2 nights of recovery sleep. Novel linear mixed-effects models were constructed using spectral and tissue segmentation data to examine changes in bioenergetics in gray and white matter. PCr increased in gray matter after 2 nights of recovery sleep relative to SD with no significant changes in white matter. Exploratory analyses also demonstrated that increases in PCr were associated with increases in electroencephalographic slow wave activity during recovery sleep. No significant changes in β-NTP were observed. These results demonstrate that sleep deprivation and subsequent recovery-induced changes in high-energy phosphates primarily occur in gray matter, and increases in PCr after recovery sleep may be related to sleep homeostasis. © 2014 Associated Professional Sleep Societies, LLC.

  2. Comparison of the clinical state and its changes in patients with Duchenne and Becker muscular dystrophy with results of in vivo {sup 31}P magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hajek, M. [MR Unit, Inst. for Clinical and Experimental Medicine, Prague (Czech Republic); Grosmanova, A. [Dept. of Neuropediatrics, Thomayer`s Hospital, Prague (Czech Republic); Horska, A. [MR Unit, Inst. for Clinical and Experimental Medicine, Prague (Czech Republic); Urban, P. [Dept. of Analytical Chemistry, Prague Inst. of Chemical Technology (Czech Republic)

    1993-12-01

    A total of 14 boys with the Duchenne and Becker forms of muscular dystrophy (DMD, BMD) were examined using {sup 31}P magnetic resonance (MR) spectroscopy; 12 boys were examined repeatedly. The results were correlated with clinical findings (including those of genetic tests) and with data obtained from examinations of an age-matched control group. Evaluation of results using principal component analysis revealed maximum variability in the following ratios: phosphocreatine/inorganic phosphate (PCr/Pi), phosphocreatine/phosphodiesters (PCr/PDe) and phosphocreatine/phosphomonoesters (PCr/PMe). A decrease in PCr/Pi correlates with weakness of the hip girdle and of the lower part of the shoulder girdle in DMD/BMD patients. The values of all ratios in the group of patients with the DMD phenotype differ significantly from results obtained in the group with the BMD phenotype. Continuous follow-up of patients using {sup 31}P MR spectroscopy revealed a marked decrease in PCr/Pi in DMD/BMD patients at an age that could be expected in subjects with a typical clinical course of DMD/BMD. An attempt to manage a concomitant disease with prednisone and carnitene was followed by an increase in PCr/Pi in 3 cases. A rise in the PCr/Pi ratio signalled clinical improvement in the patients. A decrease in PCr/Pi was found after controlled physical training, a finding consistent with data obtained from clinical observations describing an adverse effect of physical stress on the dystrophic process. (orig.)

  3. Changes in energy metabolism in the quadriceps femoris after a single bout of acute exhaustive swimming in rats: a 31p-magnetic resonance spectroscopy study

    Institute of Scientific and Technical Information of China (English)

    Sun Yingwei; Pan Shinong; Chen Zhian; Zhao Heng; Ma Ying; Zheng Liqiang; Li Qi

    2014-01-01

    Background Little is known about the value of 31P-magnetic resonance spectroscopy (31P-MRS) in in vivo assessment of exhaustive exercise-induced injury in skeletal muscle.We aimed to evaluate the value of a 31P-MRS study using the quadriceps femoris after a single bout of acute exhaustive swimming in rats,and the correlation between 31P-MRS and histological changes.Methods Sixty male Sprague-Dawley rats were randomly assigned to control,half-exhaustive,and exhaustive exercise groups.31P-MRS of the quadriceps femoris of the right lower limb was performed immediately after swimming exercise to detect Pi,PCr,and β-ATP.The Pi/PCr,Pi/β-ATP,PCr/β-ATP,and PCr/(PCr+Pi) were calculated and pH measured.Areas under the receiver operating characteristic curve (AUCs) were calculated to evaluate the diagnostic potential of 31P-MRS in identifying and distinguishing the three groups.HE staining,electron microscopy and desmin immunostaining after imaging of the muscle were used as a reference standard.The correlation between 31P-MRS and the mean absorbance (A value) of desmin staining were analyzed with the Pearson correlation test.Results Pi,PCr,Pi/PCr,and PCr/(PCr+Pi) showed statistically significant intergroup differences (P<0.05).AUCs of Pi,PCr,Pi/PCr,and PCr/(PCr+Pi) were 0.905,0.848,0.930,and 0.930 for the control and half-exhaustive groups,while sensitivity and specificity were 90%/85%,95%/55%,95%/80%,and 90%/85%,respectively.The AUCs of Pi,PCr,Pi/PCr and PCr/(PCr+Pi) were 0.995,0.980,1.000,and 1.000 for the control and exhaustive groups,while sensitivity and specificity were 95%/90%,100%/90%,100%/95%,and 100%/95%,respectively.The AUCs of Pi,PCr,Pi/PCr,and PCr/(PCr+Pi) were 0.735,0.865,0.903,and 0.903 for the half-exhaustive and exhaustive groups,while sensitivity and specificity were 80%/60%,90%/75%,95%/65%,and 95%/70%,respectively.In the half-exhaustive group,some muscle fibers exhibited edema in HE staining,and the

  4. Metabolic Changes in Rats with Photochemically Induced Cerebral Infarction and the Effects of Batroxobin: A Study by Magnetic Resonance Imaging, 1H- and 31P- Magnetic Resonance Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    管兴志; 吴卫平; 匡培根; 匡培梓; 高杨; 管林初; 李丽云; 毛希安; 刘买利

    2001-01-01

    Metabolic changes in rats with photochemically induced cerebral infarction and the effects of batroxobin were investigated 1, 3, 5 and 7 days after infarction by means of magnetic resonance imaging (MRI), 1H- and 31P- magnetic resonance spectroscopy (MRS). A region of T2 hyperintensity was observed in left temporal neocortex in infarction group and batroxobin group 1, 3, 5 and 7 days after infarction. The volume of the region gradually decreased from 1 day to 7 days after infarction. The ratio of NAA/Cho+Cr in the region of T2 hyperintensity in the infarction group was significantly lower than that in the corresponding region in the sham-operated group 3, 5 and 7 days after infarction respectively (P<0.05). Lac appeared in the region of T2 hyperintensity in the infarction group 1, 3, 5 and 7 days after infarction, but it was not observed in the corresponding region in sham-operated group at all time points. Compared with the sham-operated group, the ratios of bATP/PME+PDE and PCr/PME+PDE of the whole brain in the infarction group were significantly lower 1, 3 and 5 days after infarction respectively (P<0.05), and the ratio of bATP/PCr also was significantly lower 1 day after infarction (P<0.05). Batroxobin significantly decreased the volume of the region of T2 hyperintensity 1 and 3 days after infarction (P<0.05), significantly increased the ratio of NAA/Cho+Cr in the region 5 and 7 days after infarction (P<0.05), significantly decreased the ratios of Lac/Cho+Cr and Lac/NAA in the region 5 and 7 days after infarction (P<0.05), and significantly increased the ratios of bATP/PME+PDE and bATP/PCr in the whole brain 1 day after infarction (P<0.05). The results indicated that the infracted region had severe edema, increased Lac and apparent neuronal dysfunction and death, and energy metabolism of the whole brain decreased after focal infarction, and that batroxobin effectively ameliorated the above-mentioned abnormal changes.

  5. Optically detected NMR of optically hyperpolarized 31P neutral donors in 28Si

    CERN Document Server

    Steger, M; Yang, A; Saeedi, K; Hayden, M E; Thewalt, M L W; Itoh, K M; Riemann, H; Abrosimov, N V; Becker, P; Pohl, H -J

    2010-01-01

    The electron and nuclear spins of the shallow donor 31P are promising qubit candidates invoked in many proposed Si-based quantum computing schemes. We have recently shown that the near-elimination of inhomogeneous broadening in highly isotopically enriched 28Si enables an optical readout of both the donor electron and nuclear spins by resolving the donor hyperfine splitting in the near-gap donor bound exciton transitions. We have also shown that pumping these same transitions can very quickly produce large electron and nuclear hyperpolarizations at low magnetic fields, where the equilibrium electron and nuclear polarizations are near zero. Here we show preliminary results of the measurement of 31P neutral donor NMR parameters using this optical nuclear hyperpolarization mechanism for preparation of the 31P nuclear spin system, followed by optical readout of the resulting nuclear spin population after manipulation with NMR pulse sequences. This allows for the observation of single-shot NMR signals with very hi...

  6. Investigation of the cerebral energy status in patients with glutaric aciduria type I by 31P magnetic resonance spectroscopy.

    Science.gov (United States)

    Möller, H E; Koch, H G; Weglage, J; Freudenberg, F; Ullrich, K

    2003-04-01

    In vivo phosphorus magnetic resonance spectroscopy (MRS) was used to investigate markers of the cerebral energy status in two patients with glutaric aciduria type I (GA-I). Besides an increased concentration of phosphomonoesters in one patient, no other significant alterations from controls were found. This might indicate increased resynthesis of dendritic processes secondary to preceding metabolic crises. In contrast to previous cell-culture studies, no cerebral depletion of phosphocreatine (PCr) was observed. In conclusion, a severe global and permanent depletion of cerebral energy supplies must be ruled out. The benefit of a permanent creatine substitution to stabilize mitochondrial energy metabolism seems thus questionable. However, as MRS was performed during stable clinical conditions, the possibility of a PCr decrease during acute metabolic crises cannot be assessed.

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

    Directory of Open Access Journals (Sweden)

    Ming Li

    2016-07-01

    Full Text Available 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

  8. Nuclear Magnetic Resonance Gyroscope

    Science.gov (United States)

    Larsen, Michael; Griffith, Robert; Bulatowicz, Michael

    2014-03-01

    The navigation grade micro Nuclear Magnetic Resonance Gyroscope (micro-NMRG) being developed by the Northrop Grumman Corporation (NGC) has concluded the fourth and final phase of the DARPA Navigation Grade Integrated Micro Gyro (NGIMG) program. Traditional MEMS gyros utilize springs as an inherent part of the sensing mechanism, leading to bias and scale factor sensitivity to acceleration and vibration. As a result, they have not met performance expectations in real world environments and to date have been limited to tactical grade applications. The Nuclear Magnetic Resonance Gyroscope (NMRG) utilizes the fixed precession rate of a nuclear spin in a constant magnetic field as an inertial reference for determining rotation. The nuclear spin precession rate sensitivity to acceleration and vibration is negligible for most applications. Therefore, the application of new micro and batch fabrication methods to NMRG technology holds great promise for navigation grade performance in a low cost and compact gyro. This presentation will describe the operational principles, design basics, and demonstrated performance of the NMRG including an overview of the NGC designs developed and demonstrated in the DARPA gyro development program.

  9. Analyzing Ph value, energy and phospholipid metabolism of various cerebral tumors and normal brain tissue with 31P magnetic resonance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Wei Tan; Guangyao Wu; Junmo Sun

    2006-01-01

    BACKGROUND: 31P magnetic resonance spectroscopy (31P MRS) can be used to non-injuredly and dynamicly detect various metabolites including phosphorus in organis and reflect changes of phospholipid metabolism and energy metabolism in tissue and pH value in cells.OBJECTIVE: To observe changes of pH value, phospholipid metabolism and energy metabolism of various cerebral tumors and normal brain tissue with 31P MRS.DESIGN: Semi-quantitative contrast observation.PARTICIPANTS: A total of 44 patients with cerebral tumor diagnosed with surgery operation were selected from the Department of Magnetic Resonance, Central South Hospital, Wuhan University from September 2004 to June 2006. All the subjects had complete 31P MRS data before steroid and operation. Among them,16 patients had glioma of grade Ⅱ-Ⅲ, 12 spongioblastoma and 16 meningioma. The mean age was (45±6)years. Another 36 subjects without focus on cerebral MRI were regarded as normal group, including 19 males and 18 females, and the mean age was (41±4) years. Included subjects were consent.METHODS: Eclipse1.5T MRS (Philips Company) was used to collect wave spectrum; jMRUI(1.3) was used to analyze experimental data and calculate pH value in voxel and ratios of phosphocreatine (PCr)/inorganic phosphate (Pi), PCr/phosphodiesterase (PDE) and phosphomonoesterase (PME)/β-adenosine triphosphate (β-ATP) of various metabolites. 31P MRS results were compared with t test between tumor patients and normal subjects.MAIN OUTCOME MEASURES: Changes of phospholipid metabolism (PME/PDE), energy metabolism (PCr/ATP) and pH value of various cerebral tumors and normal brain tissues.RESULTS: A total of 44 cases with cerebral tumor and 36 normal subjects were involved in the final analysis. pH value and semi-quantitative measurements of normal brain tissues and various cerebral tumors: ① pH value at top occipital region and temple occipital region of normal brain tissue was 7.04±0.02;PCt/β-ATP was 1.51 ±0.03; PCt/Pi was 2.85

  10. Evidence for a "metabolically inactive" inorganic phosphate pool in adenosine triphosphate synthase reaction using localized 31P saturation transfer magnetic resonance spectroscopy in the rat brain at 11.7 T.

    Science.gov (United States)

    Tiret, Brice; Brouillet, Emmanuel; Valette, Julien

    2016-09-01

    With the increased spectral resolution made possible at high fields, a second, smaller inorganic phosphate resonance can be resolved on (31)P magnetic resonance spectra in the rat brain. Saturation transfer was used to estimate de novo adenosine triphosphate synthesis reaction rate. While the main inorganic phosphate pool is used by adenosine triphosphate synthase, the second pool is inactive for this reaction. Accounting for this new pool may not only help us understand (31)P magnetic resonance spectroscopy metabolic profiles better but also better quantify adenosine triphosphate synthesis.

  11. Anestésicos locais: interação com membranas de eritrócitos de sangue humano, estudada por ressonância magnética nuclear de 1H e 31P

    Directory of Open Access Journals (Sweden)

    Fraceto Leonardo Fernandes

    2004-01-01

    Full Text Available The literature carries many theories about the mechanism of action of local anesthetics (LA. We can highlight those focusing the direct effect of LA on the sodium channel protein and the ones that consider the interaction of anesthetic molecules with the lipid membrane phase. The interaction between local anesthetics and human erythrocyte membranes has been studied by ¹H and 31P nuclear magnetic resonance spectroscopy. It was found that lidocaine (LDC and benzocaine (BZC bind to the membranes, increase the mobility of the protons of the phospholipid's acyl chains, and decrease the mobility and/or change the structure of the polar head groups. The results indicate that lidocaine molecules are inserted across the polar and liquid interface of the membrane, establishing both electrostatic (charged form and hydrophobic (neutral form interactions. Benzocaine locates itself a little deeper in the bilayer, between the interfacial glycerol region and the hydrophobic core. These changes in mobility or conformation of membrane lipids could affect the Na+-channel protein insertion in the bilayer, stabilizing it in the inactivated state, thus causing anesthesia.

  12. Shell effects in nuclear magnetization

    Energy Technology Data Exchange (ETDEWEB)

    Kondratyev, V.N.; Maruyama, Toshiki; Chiba, Satoshi [Advanced Science Research Center, Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan)

    2000-08-01

    The magnetization of nuclei in strong magnetic fields associated with magnetars' is considered within the shell model. It is demonstrated that the magnetic field gives rise to a phase-shift of the shell-oscillations in nuclear masses shifting significantly the nuclear magic numbers of the iron region towards smaller mass numbers. Shell-effects are found to result in anomalies of the nuclear magnetization. Such anomalies resemble the behavior associated with a phase transition. (author)

  13. Changes of liver metabolite concentrations in adults with disorders of fructose metabolism after intravenous fructose by 31P magnetic resonance spectroscopy.

    Science.gov (United States)

    Boesiger, P; Buchli, R; Meier, D; Steinmann, B; Gitzelmann, R

    1994-10-01

    A novel 31P magnetic resonance spectroscopy procedure allows the estimation of absolute concentrations of certain phosphorus-containing compounds in liver. We have validated this approach by measuring ATP, phosphomonesters, and inorganic phosphate (Pi) during fasting and after an i.v. fructose bolus in healthy adults and in three adults with disorders of fructose metabolism and by comparing results with known metabolic concentrations measured chemically. During fasting, the ATP concentration averaged 2.7 +/- 0.3 (SD, n = 9) mmol/L, which, after due correction for other nucleoside triphosphates, was 2.1 mmol/L and corresponded well with known concentrations. Fructose-1-phosphate (F-1-P) could not be measured during fasting; its concentration after fructose was calculated from the difference of the phosphomonester signals before (2.9 +/- 0.2 mmol/L) and after fructose. Pi was 1.4 +/- 0.3 mmol/L and represented the one fourth of Pi visible in magnetic resonance spectra. In the three healthy controls after fructose (200 mg/kg, 20% solution, 2.5 min), the fructokinase-mediated increase of F-1-P was rapid, reaching 4.9 mmol/L within 3 min, whereas the uncorrected ATP decreased from 2.7 to 1.8 mmol/L and the Pi from 1.4 to 0.3 mmol/L. The subsequent decrease of F-1-P, mediated by fructaldolase, was accompanied by an overshooting rise of Pi to 2.7 mmol/L. In the patient with essential fructosuria, the concentrations of F-1-P, ATP, and Pi remained unchanged, confirming that fructokinase was indeed inactive. In the patient with hereditary fructose intolerance, initial metabolic changes were the same as in the controls, but baseline concentrations were not yet reestablished after 7 h, indicating weak fructaldolase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. 31P magnetic resonance spectroscopic imaging with polarisation transfer of phosphomono- and diesters at 3 T in the human brain: relation with age and spatial differences.

    NARCIS (Netherlands)

    Wijnen, J.P.; Scheenen, T.W.J.; Klomp, D.W.J.; Heerschap, A.

    2010-01-01

    Tissue levels of the compounds phosphocholine (PC), phosphoethanolamine (PE), glycerophosphocholine (GPC) and glycerophosphoethanolamine (GPE) can be studied by in vivo 31P MRS. However, the detection of the signals of these compounds suffers from low sensitivity and contamination by underlying

  15. 2006 Rose Site 31P

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Underwater Site 31P was established off Rose Atoll, American Samoa by Dr. James Maragos, U.S. Fish & Wildlife Service, on August 22, 1999. The site was...

  16. 1999 Rose Site 31P

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Underwater Site 31P was established off Rose Atoll, American Samoa by Dr. James Maragos, U.S. Fish & Wildlife Service, on August 22, 1999. The site was...

  17. 2005 Rose Site 31P

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Underwater Site 31P was established off Rose Atoll, American Samoa by Dr. James Maragos, U.S. Fish (5) = between meters 4 and 5). Quantitative analysis of the...

  18. 2012 Rose Site 31P

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Underwater Site 31P was established off Rose Atoll, American Samoa by Dr. James Maragos, U.S. Fish & Wildlife Service, on August 22, 1999. The site was...

  19. 2004 Rose Site 31P

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Underwater Site 31P was established off Rose Atoll, American Samoa by Dr. James Maragos, U.S. Fish & Wildlife Service, on August 22, 1999. The site was...

  20. 31P-MRS评价肝细胞癌代谢水平及其与临床、病理特征的关系%Relationship between clinical-pathological features and metabolic status of hepatocellular carcinoma detected by 31p magnetic resonance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    于德新; 马祥兴; 李笃民; 张晓明; 王茜; 李传福

    2011-01-01

    Objective To examine the relationship between clinical-pathological features and metabolic status of hepato-cellular carcinoma (HCC) using in vivo 3IP magnetic resonance spectroscopy (31P-MRS). Methods 31P-MRS scanning with a single voxel was carried out on 32 HCC lesions. Groups were formed for the following: with and without capsula, with and without cirrhosis, and with and without infiltration (intrahepatic daughter foci, tumor-emboli in portal veins and lymphatic metastasis). Another group was formed according to the pathological grades of the lesions. Intra-cellular pH value (pHi), and metabolic parameters including phosphomonoester (PME), phosphodiester (PDE), inorganic phosphate (Pi), y-ATP, 0-ATP, a-ATP, lower energetic phosphate (LEP), and the ratios PME/ATP, Pi/ ATP, PME/PDE, PME/Pi, PDE/Pi and PDE/ATP were calculated. Differences in the metabolic parameters between different groups were analyzed. Results HCC exhibited higher values for pHi, Pi, Pi/ATP and LEP, but lower values for o-ATP and PDE/Pi, than the liver (P 0.05). Conclusion Some phosphorus metabolites in HCC are related to clinical-pathological features, and 3IP-MRS can be used to evaluate the biological behavior of HCC in a non-invasive fashion.%目的 利用31 P-MRS检测肝细胞癌(HCC),探讨各代谢参数与临床及病理特征的关系.方法 对32个肝细胞癌病灶进行单体素31P-MRS扫描.根据手术及病理结果显示有无包膜、肝硬化、侵袭转移性以及恶性程度分别进行分组.根据31P-MRS扫描结果计算肝细胞内pH值(pHi)、磷酸单脂(PME)、磷酸双脂(PDE)、无机磷(Pi)、γ-ATP、β-ATP、α-ATP、PME/ATP、Pi/ATP、PME/PDE、PME/Pi、PDE/Pi、PDE/ATP和低能磷酸盐(LEP)等参数.分析以上代谢参数在各分组之间差异.结果 HCC的pHi、Pi、Pi/ATP、LEP均明显大于周围肝组织,α-ATP和PDE/Pi则相反(P<0.05).包膜组病灶的β-ATP小于无包膜组(t=2.290,P=0.029).肝硬化组HCC病灶pHi大于无

  1. GHz nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Cross, T.A.; Drobny, G.; Trewhella, J.

    1994-12-01

    For the past dozen years, 500- and 600-MHz spectrometers have become available in many laboratories. The first 600-MHz NMR spectrometer (at Carnegie Mellon University) was commissioned more than 15 years ago and, until 1994, represented the highest field available for high-resolution NMR. This year, we have witnessed unprecedented progress in the development of very high field magnets for NMR spectroscopy, including the delivery of the first commercial 750-MHz NMR spectrometers. In addition, NMR signals have been obtained from 20-Tesla magnets (850 MHz for {sup 1}H`s) at both Los Alamos National Laboratory and Florida State University in the NHMFL (National High Magnetic Field Laboratory). These preliminary experiments have been performed in magnets with 100-ppm homogeneity, but a 20-Tesla magnet developed for the NHMFL will be brought to field this year with a projected homogeneity of 0.1 ppm over a 1-cm-diam spherical volume.

  2. Nuclear magnetic resonance-based quantification of organic diphosphates.

    Science.gov (United States)

    Lenevich, Stepan; Distefano, Mark D

    2011-01-15

    Phosphorylated compounds are ubiquitous in life. Given their central role, many such substrates and analogs have been prepared for subsequent evaluation. Prior to biological experiments, it is typically necessary to determine the concentration of the target molecule in solution. Here we describe a method where concentrations of stock solutions of organic diphosphates and bisphosphonates are quantified using (31)P nuclear magnetic resonance (NMR) spectroscopy with standard instrumentation using a capillary tube with a secondary standard. The method is specific and is applicable down to a concentration of 200 μM. The capillary tube provides the reference peak for quantification and deuterated solvent for locking.

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

    Science.gov (United States)

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

  4. Transport and compartmentation of phosphite in higher plant cells - kinetic and 31P nuclear magnetic resonance studies

    NARCIS (Netherlands)

    Danova-Alt, R.; Dijkema, C.; Waard, de P.; Köck, M.

    2008-01-01

    Phosphite (Phi, H(2)PO(3)(-)), being the active part of several fungicides, has been shown to influence not only the fungal metabolism but also the development of phosphate-deficient plants. However, the mechanism of phosphite effects on plants is still widely unknown. In this paper we analysed upta

  5. 31P Magnetic resonance spectroscopyによるラット精巣機能の評価法の検討

    OpenAIRE

    鈴木, 裕志; 蟹本, 雄右; 岡田, 謙一郎; 石井, 靖

    1995-01-01

    精巣の血流遮断と解除,放射線照射,およびホルモン投与の3つの条件下で31P MRSを測定した。1)血流遮断後,ATPはすみやかに減少し60分以内に完全に消失した。2) 3時間までの血流遮断では遮断解除後にATPの回復が認められたが,4時間以上の遮断では解除後もATPの回復は認められなかった。3)放射線照射2週間後ではPME/β-ATP比およびPME/PDE比の減少が認められ,PMEの減少は造精機能障害の指標として有用と考えられた。4)ホルモン投与によるgonadotropin抑制モデルでは,PME/PDE比の減少とPDE/β-ATPの増加を認め,PDEの増加も造精機能障害の第二の指標となりうる...

  6. Efficient dynamic nuclear polarization of phosphorus in silicon in strong magnetic fields and at low temperatures

    Science.gov (United States)

    Järvinen, J.; Ahokas, J.; Sheludyakov, S.; Vainio, O.; Lehtonen, L.; Vasiliev, S.; Zvezdov, D.; Fujii, Y.; Mitsudo, S.; Mizusaki, T.; Gwak, M.; Lee, SangGap; Lee, Soonchil; Vlasenko, L.

    2014-12-01

    Efficient manipulation of nuclear spins is important for utilizing them as qubits for quantum computing. In this work we report record high polarizations of 31P and 29Si nuclear spins in P-doped silicon in a strong magnetic field (4.6 T) and at temperatures below 1 K. We reached 31P nuclear polarization values exceeding 98 % after 20 min of pumping the high-field electron spin resonance (ESR) line with a very small microwave power of 0.4 μ W . We evaluate that the ratio of the hyperfine-state populations increases by three orders of magnitude after 2 hours of pumping, and an extremely pure nuclear spin state can be created, with less than 0.01 ppb impurities. A negative dynamic nuclear polarization has been observed by pumping the low-field ESR line of 31P followed by the flip-flip cross relaxation, the transition which is fully forbidden for isolated donors. We estimate that while pumping the ESR transitions of 31P also the nuclei of 29Si get polarized, and polarization exceeding 60 % has been obtained. We performed measurements of relaxation rates of flip-flop and flip-flip transitions which turned out to be nearly temperature independent. Temperature dependence of the 31P nuclear relaxation was studied down to 0.75 K, below which the relaxation time became too long to be measured. We found that the polarization evolution under pumping and during relaxation deviates substantially from a simple exponential function of time. We suggest that the nonexponential polarization dynamics of 31P donors is mediated by the orientation of 29Si nuclei, which affect the transition probabilities of the forbidden cross-relaxation processes.

  7. Evanescent Waves Nuclear Magnetic Resonance

    DEFF Research Database (Denmark)

    Halidi, El Mohamed; Nativel, Eric; Akel, Mohamad

    2016-01-01

    Nuclear Magnetic Resonance spectroscopy and imaging can be classified as inductive techniques working in the near- to far-field regimes. We investigate an alternative capacitive detection with the use of micrometer sized probes positioned at sub wavelength distances of the sample in order...

  8. Germination of Dictyotelium discoideum spores. A sup 31 P NMR analysis

    Energy Technology Data Exchange (ETDEWEB)

    Klein, G.; Martin, J.B.; Bof, M.; Satre, M. (Centre d' Etudes Nucleaires, Grenoble (France)); Cotter, D.A. (Univ. of Windsor, Ontario (Canada))

    1988-10-18

    Perchloric acid extracts of Dictyostelium spores have been investigated by {sup 31}P nuclear magnetic resonance (NMR) spectroscopy. This analysis has allowed the assignment of all the {sup 31}P resonances observed in vivo to specific compounds. Dormant spores have been found to contain as prominent phosphorylated metabolites two phosphomonoesters, phosphoethanolamine and inositol hexakis(phosphate), two phosphodiesters, glycerophosphocholine and glycerophosphoethanolamine, as well as nucleoside triphosphates and polyphosphates. The very large amounts of glycerophosphocholine, glycerophosphoethanolamine, and phosphoethanolamine in spores were the most remarkable differences from Dictyostelium amoebae. In vivo {sup 31}P NMR has shown that the peak of nucleoside triphosphates in dormant spores was maintained metabolically since it disappeared completely upon anaerobiosis. The pH-sensitive {sup 31}P NMR signal of phosphoethanolamine was used to determine internal pH, and a value of pH 6.5 was found in aerobic Dictyostelium dormant spores. Spore germination, induced by activation with heat shock treatment, was monitored noninvasively by {sup 31}P NMR. No change in phosphorylated components was observed to have occurred during the activation step. The major modifications in phosphorylated metabolites observed upon germination of the activated spores were the progressive disappearance of the two phosphodiesters glycerophosphocholine and glycerophosphoethanolamine.

  9. Evanescent Waves Nuclear Magnetic Resonance

    DEFF Research Database (Denmark)

    Halidi, El Mohamed; Nativel, Eric; Akel, Mohamad

    2016-01-01

    Nuclear Magnetic Resonance spectroscopy and imaging can be classified as inductive techniques working in the near- to far-field regimes. We investigate an alternative capacitive detection with the use of micrometer sized probes positioned at sub wavelength distances of the sample in order to char...... a new road to a better understanding of the evanescent waves component in NMR with the opportunity to perform localized spectroscopy and imaging....

  10. Ab Initio Calculations of 31P NMR Chemical Shielding Anisotropy Tensors in Phosphates: Variations Due to Ring Formation

    Directory of Open Access Journals (Sweden)

    Todd M. Alam

    2002-08-01

    Full Text Available Abstract: Ring formation in phosphate systems is expected to influence both the magnitude and orientation of the phosphorus (31P nuclear magnetic resonance (NMR chemical shielding anisotropy (CSA tensor. Ab initio calculations of the 31P CSA tensor in both cyclic and acyclic phosphate clusters were performed as a function of the number of phosphate tetrahedral in the system. The calculation of the 31P CSA tensors employed the GAUSSIAN 98 implementation of the gauge-including atomic orbital (GIAO method at the Hartree-Fock (HF level. It is shown that both the 31P CSA tensor anisotropy, and the isotropic chemical shielding can be used for the identification of cyclic phosphates. The differences between the 31P CSA tensor in acyclic and cyclic phosphate systems become less pronounced with increasing number of phosphate groups within the ring. The orientation of the principal components for the 31P CSA tensor shows some variation due to cyclization, most notably with the smaller, highly strained ring systems.

  11. Nuclear magnetic ordering in silver

    Energy Technology Data Exchange (ETDEWEB)

    Lefmann, K.

    1995-12-01

    Nuclear antiferromagnetic ordering has been observed by neutron diffraction in a single crystal of {sup 109}Ag. The critical temperature is found to 700 pK, and the critical field is 100 {mu}T. From the paramagnetic phase a second order phase transition leads into a type-I 1-k structure with long range order. The experiments have taken place at the Hahn-Meitner Institut in Berlin in collaboration with the low Temperature Laboratory in Helsinki, the Niels Bohr Institute in Copenhagen, and Risoe National Laboratory, Roskilde. The present report is a Ph.D. thesis which has been successfully defended at the Niels Bohr Institute. Besides the results of the nuclear ordering experiments the thesis contains a description of the theoretical background for nuclear magnetism and a review of earlier nuclear ordering experiments as well as theoretical work. The principles for studying polarized nuclei with use of polarized and unpolarized neutrons are presented, as well as the results of such experiments. (au) 11 tabs., 59 ills., 143 refs.

  12. Protein dynamics from nuclear magnetic relaxation.

    Science.gov (United States)

    Charlier, Cyril; Cousin, Samuel F; Ferrage, Fabien

    2016-05-01

    Nuclear magnetic resonance is a ubiquitous spectroscopic tool to explore molecules with atomic resolution. Nuclear magnetic relaxation is intimately connected to molecular motions. Many methods and models have been developed to measure and interpret the characteristic rates of nuclear magnetic relaxation in proteins. These approaches shed light on a rich and diverse range of motions covering timescales from picoseconds to seconds. Here, we introduce some of the basic concepts upon which these approaches are built and provide a series of illustrations.

  13. 31P NMR for the study of P metabolism and translocation in arbuscular mycorrhizal fungi

    DEFF Research Database (Denmark)

    Rasmussen, N.; Lloyd, D.C.; Ratcliffe, R.G.

    2000-01-01

    P-31 nuclear magnetic resonance (NMR) spectroscopy was used to study phosphate (P) metabolism in mycorrhizal and nonmycorrhizal roots of cucumber (Cucumis sativus L) and in external mycelium of the arbuscular mycorrhizal (AM) fungus Glomus intraradices Schenck & Smith. The in vivo NMR method allows...... biological systems to be studied non-invasively and non-destructively. (3)1P NMR experiments provide information about cytoplasmic and vacuolar pH, based on the pH-dependent chemical shifts of the signals arising from the inorganic P (P-i) located in the two compartments. Similarly, the resonances arising...... from alpha, beta and gamma phosphates of nucleoside triphosphates (NTP) and nucleoside diphosphates (NDP) supply knowledge about the metabolic activity and the energetic status of the tissue. In addition, the kinetic behaviour of P uptake and storage can be determined with this method. The (3)1P NMR...

  14. 31-P-Magnetresonanztomographie der menschlichen Leber

    OpenAIRE

    2006-01-01

    Die 31-P-Magnetresonanz-Spektroskopie (31-P-MRS) ist eine nicht-invasive Methode, welche einen direkten Einblick in den Phospholipid-Haushalt der menschlichen Leber erlaubt. Mit der 31-P-MR-Spektroskopie wurden Spektren von 10 Patienten mit Leberzirrhose sowie von 13 gesunden Probanden in Kombination mit dem Lokalisationsverfahren 3D-CSI und dem Nachbearbeitungsprogramm SLOOP (Spectral Localization with Optimal Pointspread Funktion) gewonnen. Die Ergebnisse dieser Studie ergaben signifikante ...

  15. 31-phosphorus magnetic resonance spectroscopy in diagnosis of the benign and malignant masses in liver%~(31)P-MRS在肝脏良、恶性占位性病变中的诊断价值

    Institute of Scientific and Technical Information of China (English)

    于德新; 刘成; 李传福; 张晓明; 马祥兴

    2009-01-01

    目的 探讨~(31)P磁共振波谱成像(MRS)在肝脏良、恶性占位性病变诊断中的价值.方法分别对35个(其中肝脓肿13个)肝脏良性病灶及62个恶性病灶进行单体素~(31)P-MRS扫描,计算肝细胞内pH值(pHi)、磷酸单脂(PME)、磷酸双脂(PDE)、无机磷(Pi)、γ-、β-、及α-三磷酸腺苷(ATP)、PME/ATP、Pi/ATP、PME/PDE、PME/Pi、PDE/Pi、PDE/ATP和低能磷酸盐(LEP)等参数.分析以上代谢参数在良、恶性病变之间差异.结果在良、恶性病变之间,γ-ATP分别为1279.46±432.21和758.22±240.79,Pi/A1P分别为3.98±0.86和5.36±0.96,差异均有统计学意义(P0.05).结论~(31)P-MRS代谢物γ-ATP和Pi/ATP可作为鉴别肝脏良、恶性病变的参数,pHi值有助于肝脓肿与肝脏肿瘤的鉴别.%Objective To probe the clinical value of 31-phosphorus magnetic resonance spectroscopy(~(31)P-MRS) in vivo at 3.0 Tesla in diagnosis of the benign and malignant masses. Methods~(31)P-MRS scanning with a single voxel was carried out on 35 benign tumors, 62 malignant ones and 13 hepatic abscesses. Intracellular pH value (pHi), and some metabolic parameters in-cluding phosphomonoester (PME), phosphodiester (PDE), inorganic phosphate (Pi), γ-,β-, and α- adenosine triphosphate (ATP), lower energetic phosphate (LEP), and the ratios of PME/ATP, Pi/ATP, PME/PDE, PME/Pi, PDE/Pi and PDE/ATP were calculated. The differences in the metabolic parameters above between benign and malignant groups were analyzed. Results The differences inγ-ATP, which were 1279.46±432.21 and 758.22±240.79 in benign and malignant lesions respectively, and Pi/ATP, 3.98±0.8 and 5.36±0.96, were identified statistically (P0.05). Conclusion Such phosphorus metabolites as γ-ATP and Pi/ATP in HCC may be used to differentiate the benign and malignant masses, while pHi is helpful for the diagnosis of hepatic abscesses.

  16. In vivo 31P magnetic resonance spectroscopy and 1H magnetic resonance imaging of human bladder carcinoma on nude mice: effects of tumour growth and treatment with cis-dichloro-diamine platinum

    DEFF Research Database (Denmark)

    De Certaines, J D; Albrectsen, J; Larsen, V A;

    1993-01-01

    phosphate and phosphomonoesters and a decrease of phosphocreatine. Fast growing tumours and early stage of regrowth after treatment presented a higher phosphocreatine/beta NTP ratio. Following CDDP treatment, 31P metabolite ratios and pH were significantly altered compared with age-matched controls......, as early as 6 hours after treatment. Although necrotic area was clearly visible in MRI, no treatment effect could be detected on the images of treated tumours....

  17. In vivo 31P magnetic resonance spectroscopy and 1H magnetic resonance imaging of human bladder carcinoma on nude mice: effects of tumour growth and treatment with cis-dichloro-diamine platinum

    DEFF Research Database (Denmark)

    De Certaines, J D; Albrectsen, J; Larsen, V A;

    1992-01-01

    phosphate and phosphomonoesters and a decrease of phosphocreatine. Fast growing tumours and early stage of regrowth after treatment presented a higher phosphocreatine/beta NTP ratio. Following CDDP treatment, 31P metabolite ratios and pH were significantly altered compared with age-matched controls......, as early as 6 hours after treatment. Although necrotic area was clearly visible in MRI, no treatment effect could be detected on the images of treated tumours....

  18. In vivo measurement of intracellular pH in human brain during different tensions of carbon dioxide in arterial blood. A 31P-NMR study

    DEFF Research Database (Denmark)

    Jensen, K E; Thomsen, C; Henriksen, O

    1988-01-01

    The effect of changes in carbon dioxide tension in arterial blood upon intracellular pH in brain tissue was studied in seven healthy volunteers, aged 22-45 years. The pH changes were monitored by use of 31P nuclear magnetic resonance spectroscopy, performed on a whole-body 1.5 Tesla Siemens imaging...

  19. Nuclear magnetic resonance. Tomography of tomorrow

    Energy Technology Data Exchange (ETDEWEB)

    Ethier, R.; Melanson, D.; Peters, T.M. (Montreal Neurological Inst., Quebec (Canada))

    1983-10-01

    Ten years following computerized tomography, a new technique called nuclear magnetic resonance revolutionizes the field of diagnostic imaging. A major advantage of nuclear magnetic resonance is that the danger of radiation is non-existent as compared to computerized tomography. When parts of the human body are subject to radio-frequencies while in a fixed magnetic field, its most detailed structures are revealed. The quality of images, the applications, as well as the indications are forever increasing. Images obtained at the level of the brain and spinal cord through nuclear magnetic resonance supercede those obtained through computerized tomography. Hence, it is most likely that myelography, along with pneumoencephalography will be eliminated as a diagnostic means. It is without a doubt that nuclear magnetic resonance is tomorrow's computerized tomography.

  20. Evaluation of liver function status in patients with obstructive jaundice using in vivo 31-phosphorus magnetic resonance spectroscopy%31p-MRS无创评估梗阻性黄疸肝功能损害的价值

    Institute of Scientific and Technical Information of China (English)

    于德新; 马祥兴; 张晓明; 张宗利; 李传福

    2009-01-01

    目的:探讨31P-MRS技术评价梗阳性黄疸旰功能损害的价值.方法:对36例梗阻性黄疸患者(黄疸组)进行单体素31P-MRS扫描,计算肝细胞内pH值(pHi)、磷酸单脂(PME)、磷酸双脂(PDE)、无机磷(Pi)、γ-ATP、β-ATP、α-ATP、PME/ATP、Pi/ATP、PME/PDE、PME/Pi、PDE/Pi、PDE/ATP和低能磷酸盐(LEP)等.检测临床肝功能血清学指标.以40例正常人为对照组,分析黄疸对31P-MRS检测参数的影响及其与肝功能血清检测指标之间的关系.结果:黄疸组肝脏PME、PDE、PME,ATP、PME/Pi、PDE/ATP及LEP均明显大于对照组,两组差异有统计学意义(P0.05).结论:31P-MRS可以对梗阻性黄疸导致的肝功能损害进行无创性评估,PME和PDE代谢物可能是反映肝功能损害较为敏感的指标.

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

    Science.gov (United States)

    Agiomyrgianaki, Alexia; Dais, Photis

    2012-11-01

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

  2. Human in vivo phosphate metabolite imaging with 31P NMR.

    Science.gov (United States)

    Bottomley, P A; Charles, H C; Roemer, P B; Flamig, D; Engeseth, H; Edelstein, W A; Mueller, O M

    1988-07-01

    Phosphorus (31P) spectroscopic images showing the distribution of high-energy phosphate metabolites in the human brain have been obtained at 1.5 T in scan times of 8.5 to 34 min at 27 and 64 cm3 spatial resolution using pulsed phase-encoding gradient magnetic fields and three-dimensional Fourier transform (3DFT) techniques. Data were acquired as free induction decays with a quadrature volume NMR detection coil of a truncated geometry designed to optimize the signal-to-noise ratio on the coil axis on the assumption that the sample noise represents the dominant noise source, and self-shielded magnetic field gradient coils to minimize eddy-current effects. The images permit comparison of metabolic data acquired simultaneously from different locations in the brain, as well as metabolite quantification by inclusion of a vial containing a standard of known 31P concentration in the image array. Values for the NMR visible adenosine triphosphate in three individuals were about 3 mM of tissue. The ratio of NMR detectable phosphocreatine to ATP in brain was 1.15 +/- 0.17 SD in these experiments. Potential sources of random and systematic error in these and other 31P measurements are identified.

  3. Near-zero-field nuclear magnetic resonance

    OpenAIRE

    Ledbetter, Micah; Theis, Thomas; Blanchard, John; Ring, Hattie; Ganssle, Paul; Appelt, Stephan; Bluemich, Bernhard; Pines, Alex; Budker, Dmitry

    2011-01-01

    We investigate nuclear magnetic resonance (NMR) in near-zero-field, where the Zeeman interaction can be treated as a perturbation to the electron mediated scalar interaction (J-coupling). This is in stark contrast to the high field case, where heteronuclear J-couplings are normally treated as a small perturbation. We show that the presence of very small magnetic fields results in splitting of the zero-field NMR lines, imparting considerable additional information to the pure zero-field spectr...

  4. Using solid 13C NMR coupled with solution 31P NMR spectroscopy to investigate molecular species and lability of organic carbon and phosphorus from aquatic plants in Tai Lake, China

    Science.gov (United States)

    Aquatic plants are involved in the storage and release capacity for organic matter and nutrients. In this study, solid 13C and solution 31P nuclear magnetic resonance (NMR) spectroscopy were used to characterize the biomass samples of six aquatic plants. Solid 13C NMR spectroscopy revealed the domin...

  5. magnetic order studied by nuclear methods

    CERN Document Server

    Reichl, C

    2001-01-01

    investigated within the frame of this work. The studies on the highly concentrated deuterides revealed a gradual loss in local field due to a distribution of 'local Curie temperatures' depending on the number of Fe neighbours and their distances from the Moessbauer nucleus. On rising the temperature, during a magnetic transition, an increasing number of Fe sites with different local environment loose their hyperfine fields, whereas bulk measurements showed a relatively sharp, however, incomplete transition. By using a combination of neutron diffraction- and muon spin relaxation studies the complex magnetic phase diagram of the system Ce(Rh,Ru) sub 3 B sub 2 , where weak magnetic moments exist, could be studied. There, transitions from para- to ferromagnetism, and more complicated magnetic structures could be observed. Due to the existence of several isotopes of B and Ru, each carrying different nuclear spins and magnetic moment, particularly complicated second moment simulations for interpreting the muon data...

  6. Fractioning of sodium polyphosphate and characterization by {sup 31}P NMR: a experience to physical-chemistry lessons; Fracionamento de polifosfato de sodio e caracterizacao por RMN de 31P: um experimento para aulas de Fisico-Quimica

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Emilia Celma de Oliveira; Alcantara, Glaucia Braz Alcantara; Damasceno, Fernando Cruvinel, E-mail: elima@quimica.ufg.b [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Inst. de Quimica; Moita Neto, Jose Machado [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil). Dept. de Quimica; Galembeck, Fernando [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica

    2010-07-01

    This text describes an experiment on fractional precipitation of a polymer together with determination of average degree of polymerization by NMR. Commercial sodium polyphosphate was fractionated by precipitation from aqueous solution by adding increasing amounts of acetone. The polydisperse salt and nine fractions obtained from it were analyzed by {sup 31}P nuclear magnetic resonance and the degree of polymerization of the salts and of the fractions were calculated. Long-chain sodium polyphosphate was also synthesized and analyzed. This experiment was tested in a PChem lab course but it can be used also to illustrate topics of inorganic polymers and analytical chemistry. (author)

  7. Musculoskeletal metabolism in patients with liver cirrhosis by 31-phosphorus magnetic resonance spectroscopy at 3.0 Tesla in vivo%~(31)P-MR波谱对肝硬化时骨骼肌能量代谢的评估

    Institute of Scientific and Technical Information of China (English)

    于德新; 马祥兴; 李笃民; 张晓明; 王茜; 李传福

    2009-01-01

    目的 探讨~(31)P-MRS技术评估肝硬化对骨骼肌代谢的影响.方法 分别对35例肝硬化患者及30例正常对照组的大腿后方骨骼肌进行单体素~(31)P-MRS扫描,计算骨骼肌细胞内pH值(pHi)、磷酸单酯(PME)、磷酸双酯(PDE)、无机磷(Pi)、磷酸肌酸(PCr)、γ-ATP、β-ATP、α-ATP、Pi/ATP、PCr/ATP、PCr/PME、PCr/PDE、PCr/Pi、PME/ATP、PME/PDE、PME/Pi、PDE/ATP、PDE/Pi等指标.分析肝硬化及其分级对骨骼肌~(31)P-MRS指标的影响.结果 肝硬化组骨骼肌的PME、PCr、β-ATP、PME/PDE及Pcr/PDE均大于正常对照组,而PDE/ATP则相反(P<0.05).在Child-Pugh分级A、B、C级患者骨骼肌的pHi分别为7.18±0.10、7.20±0.10、7.41±0.08,具有统计学差异(P=0.041,F=4.629);PME/PDE分别为0.57±0.26、0.68±0.24、1.16±0.24,也存在明显差异(P=0.047,F=4.254),而其余代谢物指标未见统计学差异(P>0.05).结论 ~(31)P-MRS可以对肝硬化患者骨骼肌的异常代谢进行无创评估,骨骼肌pHi及PME/PDE随肝硬化Child-Pugh分级的增加而上升.

  8. Evaluation of Liver Cirrhosis and Its Child-Pugh Stage Using Vivo 31-phosphorus Magnetic Resonance Spectroscopy at 3.0 Tesla%31P-MRS在评估肝硬化及其分级中的价值

    Institute of Scientific and Technical Information of China (English)

    于德新; 马祥兴; 李笃民; 张晓明; 王茜; 李传福

    2009-01-01

    目的 探讨31P-磁共振波谱(MRS)无创评估肝硬化及其分级的价值.资料与方法 分别对53例肝硬化患者及28名正常对照组进行单体素31P-MRS扫描,计算肝细胞内pH值(pHi)、磷酸单酯(PME)、磷酸双酯(PDE)、无机磷(Pi)、磷酸肌酸(PCr)、γ-ATP、β-ATP、α-ATP、PME/ATP、Pi/ATP、PCr/ATP、PME/PDE、PME/Pi、PDE/Pi、PDE/ATP比值和低能磷酸盐(LEP)等代谢指标.探讨以上各参数在肝硬化及其Child-Pugh分级中的异同.结果 在肝硬化组,PME、PME/ATP、PME/PDE及PME/Pi均大于正常对照组(P0.05).结论 肝硬化时PME相关参数明显升高,PME、Pi和PME/Pi可对肝硬化的程度进行评估.

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

    Science.gov (United States)

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

    2016-09-01

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

  10. Animal manure phosphorus characterization by sequential chemical fractionation, release kinetics and 31P-NMR analysis

    Directory of Open Access Journals (Sweden)

    Tales Tiecher

    2014-10-01

    Full Text Available Phosphate release kinetics from manures are of global interest because sustainable plant nutrition with phosphate will be a major concern in the future. Although information on the bioavailability and chemical composition of P present in manure used as fertilizer are important to understand its dynamics in the soil, such studies are still scarce. Therefore, P extraction was evaluated in this study by sequential chemical fractionation, desorption with anion-cation exchange resin and 31P nuclear magnetic resonance (31P-NMR spectroscopy to assess the P forms in three different dry manure types (i.e. poultry, cattle and swine manure. All three methods showed that the P forms in poultry, cattle and swine dry manures are mostly inorganic and highly bioavailable. The estimated P pools showed that organic and recalcitrant P forms were negligible and highly dependent on the Ca:P ratio in manures. The results obtained here showed that the extraction of P with these three different methods allows a better understanding and complete characterization of the P pools present in the manures.

  11. Experimental test of nuclear magnetization distribution and nuclear structure models

    Energy Technology Data Exchange (ETDEWEB)

    Beirsdorfer, P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lopez-Urrutia, J Crespo R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Utter, S. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1999-02-26

    Models exist that ascribe the nuclear magnetic fields to the presence of a single nucleon whose spin is not neutralized by pairing it up with that of another nucleon; other models assume that the generation of the magnetic field is shared among some or all nucleons throughout the nucleus. All models predict the same magnetic field external to the nucleus since this is an anchor provided by experiments. The models differ, however, in their predictions of the magnetic field arrangement within the nucleus for which no data exist. The only way to distinguish which model gives the correct description of the nucleus would be to use a probe inserted into the nucleus. The goal of our project was to develop exactly such a probe and to use it to measure fundamental nuclear quantities that have eluded experimental scrutiny. The need for accurately knowing such quantities extends far beyond nuclear physics and has ramifications in parity violation experiments on atomic traps and the testing of the standard model in elementary particle physics. Unlike scattering experiments that employ streams of free particles, our technique to probe the internal magnetic field distribution of the nucleus rests on using a single bound electron. Quantum mechanics shows that an electron in the innermost orbital surrounding the nucleus constantly dives into the nucleus and thus samples the fields that exist inside. This sampling of the nucleus usually results in only minute shifts in the electron' s average orbital, which would be difficult to detect. By studying two particular energy states of the electron, we can, however, dramatically enhance the effects of the distribution of the magnetic fields in the nucleus. In fact about 2% of the energy difference between the two states, dubbed the hyperfine splitting, is determined by the effects related to the distribution of magnetic fields in the nucleus, A precise measurement of this energy difference (better than 0.01%) would then allow us to

  12. 1H MAS and 1H --> 31P CP/MAS NMR study of human bone mineral.

    Science.gov (United States)

    Kaflak-Hachulska, A; Samoson, A; Kolodziejski, W

    2003-11-01

    Chemical structure of human bone mineral was studied by solid-state nuclear magnetic resonance (NMR) with magic-angle spinning (MAS). Trabecular and cortical bone samples from adult subjects were compared with mineral standards: hydroxyapatite (HA), hydrated and calcined, carbonatoapatite of type B with 9 wt% of CO3(2-) (CHA-B), brushite (BRU) and mixtures of HA with BRU. Proton spectra were acquired with excellent spectral resolution provided by ultra-high speed MAS at 40 kHz. 2D 1H-31P NMR heteronuclear correlation was achieved by cross-polarization (CP) under fast MAS at 12 kHz. 31P NMR was applied with CP from protons under slow MAS at 1 kHz. Appearance of 31P rotational sidebands together with their CP kinetics were analyzed. It was suggested that the sidebands of CP spectra are particularly suitable for monitoring the state of apatite crystal surfaces. The bone samples appeared to be deficient in structural hydroxyl groups analogous to those in HA. We found no direct evidence that the HPO4(2-) brushite-like ions are present in bone mineral. The latter problem is extensively discussed in the literature. The study proves there is a similarity between CHA-B and bone mineral expressed by their similar NMR behavior.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2016-11-01

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

  15. Evaluation of cerebro-circulatory metabolic conditions and prognosis in hypertensive putaminal hemorrhage by {sup 31}P-MRS

    Energy Technology Data Exchange (ETDEWEB)

    Deguchi, Itaru [Tokyo Medical Coll. (Japan)

    2000-07-01

    Phosphorus-31 nuclear magnetic resonance spectroscopy ({sup 31}P-MRS) provides a non-invasive means to obtain metabolic information. We studied cerebro-circulatory metabolic conditions in the subacute phase of hypertensive putaminal hemorrhage with {sup 31}P-MRS and N-isopropyl-I-(123)-p-Iodoamphetamine single photon emission computed tomography ({sup 123}I-IMP SPECT). The subjects consisted of 33 cases of hypertensive putaminal hemorrhage. Upon evaluation of cerebral blood flow (CBF) around the ipsilateral frontal lobe cortex and examination by {sup 123}I-IMP SPECT, they would broadly divided into the following three groups: (A) a group with high uptake on both the early image and delayed image, (B) a group with low uptake on the early image but with good redistribution, and (C) a group with low uptake on both images. In these groups {sup 31}P-MRS in the ipsilateral frontal lobe cortex was measured for comparative analysis. In group A, the PCr/Pi ratio was 3.12{+-}0.14 as opposed to 2.87{+-}0.13 in group B, and the ratio was extremely depressed in group C, 1.96{+-}0.16. These observations implied that a high level circulatory metabolic disorder was present in group C and that local viability or metabolic activity was relatively well maintained despite the low perfusion in group B with a satisfactory prognosis being expected due to their high functional level. (author)

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

    Science.gov (United States)

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

    2008-07-23

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

  17. Nonuniform backbone conformation of deoxyribonucleic acid indicated by phosphorus-31 nuclear magnetic resonance chemical shift anisotropy.

    Science.gov (United States)

    Shindo, H; Wooten, J B; Pheiffer, B H; Zimmerman, S B

    1980-02-05

    31P nuclear magnetic resonance of highly oriented DNA fibers has been observed for three different conformations, namely, the A, B, and C forms of DNA. At a parallel orientation of the fiber axis with respect to the magnetic field, DNA fibers in both the A and B forms exhibit a single, abnormally broad resonance; in contrast, fibers in the C form show almost the full span of the chemical shift anisotropy (170 ppm). The spectra of the fibers oriented perpendicular indicate that the DNA molecules undergo a considerable rotational motion about the helical axis, with a rate of greater than 2 x 10(3) s-1 for the B-form DNA. Theoretical considerations indicate that the 31P chemical shift data for the B-form DNA fibers are consistent with the atomic coordinates of the phosphodiester group proposed by Langridge et al. [Langridge, R., Wilson, H. R. Hooper, C. W., Wilkins, M. H. F., & Hamilton, L. D. (1960) J. Mol. Biol. 2, 19--37] but not with the corresponding coordinates proposed by Arnott and Hukins [Arnott, S., & Hukins, D. W. L. (1972) Biochem. Biophys. Res. Coomun. 47, 1504--1509], and also lead to the conclusion that the phosphodiester orientation must vary significantly along the DNA molecule. The latter result suggests that DNA has significant variations in its backbone conformation along the molecule.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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%.

  20. Near-zero-field nuclear magnetic resonance

    CERN Document Server

    Ledbetter, Micah; Blanchard, John; Ring, Hattie; Ganssle, Paul; Appelt, Stephan; Bluemich, Bernhard; Pines, Alex; Budker, Dmitry

    2011-01-01

    We investigate nuclear magnetic resonance (NMR) in near-zero-field, where the Zeeman interaction can be treated as a perturbation to the electron mediated scalar interaction (J-coupling). This is in stark contrast to the high field case, where heteronuclear J-couplings are normally treated as a small perturbation. We show that the presence of very small magnetic fields results in splitting of the zero-field NMR lines, imparting considerable additional information to the pure zero-field spectra. Experimental results are in good agreement with first-order perturbation theory and with full numerical simulation when perturbation theory breaks down. We present simple rules for understanding the splitting patterns in near-zero-field NMR, which can be applied to molecules with non-trivial spectra.

  1. Near-zero-field nuclear magnetic resonance.

    Science.gov (United States)

    Ledbetter, M P; Theis, T; Blanchard, J W; Ring, H; Ganssle, P; Appelt, S; Blümich, B; Pines, A; Budker, D

    2011-09-02

    We investigate nuclear magnetic resonance (NMR) in near zero field, where the Zeeman interaction can be treated as a perturbation to the electron mediated scalar interaction (J coupling). This is in stark contrast to the high-field case, where heteronuclear J couplings are normally treated as a small perturbation. We show that the presence of very small magnetic fields results in splitting of the zero-field NMR lines, imparting considerable additional information to the pure zero-field spectra. Experimental results are in good agreement with first-order perturbation theory and with full numerical simulation when perturbation theory breaks down. We present simple rules for understanding the splitting patterns in near-zero-field NMR, which can be applied to molecules with nontrivial spectra.

  2. Nanoscale nuclear magnetic resonance with chemical resolution

    Science.gov (United States)

    Aslam, Nabeel; Pfender, Matthias; Neumann, Philipp; Reuter, Rolf; Zappe, Andrea; Fávaro de Oliveira, Felipe; Denisenko, Andrej; Sumiya, Hitoshi; Onoda, Shinobu; Isoya, Junichi; Wrachtrup, Jörg

    2017-07-01

    Nuclear magnetic resonance (NMR) spectroscopy is a key analytical technique in chemistry, biology, and medicine. However, conventional NMR spectroscopy requires an at least nanoliter-sized sample volume to achieve sufficient signal. We combined the use of a quantum memory and high magnetic fields with a dedicated quantum sensor based on nitrogen vacancy centers in diamond to achieve chemical shift resolution in 1H and 19F NMR spectroscopy of 20-zeptoliter sample volumes. We demonstrate the application of NMR pulse sequences to achieve homonuclear decoupling and spin diffusion measurements. The best measured NMR linewidth of a liquid sample was ~1 part per million, mainly limited by molecular diffusion. To mitigate the influence of diffusion, we performed high-resolution solid-state NMR by applying homonuclear decoupling and achieved a 20-fold narrowing of the NMR linewidth.

  3. Simultaneous 31P NMR spectroscopy and EMG in exercising and recovering human skeletal muscle: technical aspects

    DEFF Research Database (Denmark)

    Vestergaard-Poulsen, P; Thomsen, C; Sinkjaer, T

    1994-01-01

    . A nonmagnetic ergometer was used for ankle dorsiflexions that activated only the anterior tibial muscle as verified by post exercise imaging. The coil design and the adiabatic sech/tanh pulse improved sensitivity by 45% and 56% respectively, compared with standard techniques. Simultaneous electromyographic......The bioenergetics of human skeletal muscle can be studied by 31P NMR spectroscopy (31P-MRS) and by surface electromyography (SEMG). Simultaneous 31P-MRS and SEMG permit accurate and noninvasive studies of the correlation between metabolic and electrical changes in exercising and recovering human...... skeletal muscle, a relationship that is still poorly understood. This study describes the optimization of skeletal muscle 31P-MRS in a whole-body magnet, involving surface coil design, utilization of adiabatic radio frequency pulses and advanced time-domain fitting, to the technical design of SEMG...

  4. Experiments in Nuclear Magnetic Resonance Microscopy

    Science.gov (United States)

    Lee, Yong; Lu, Wei; Choi, J.-H.; Chia, H. J.; Mirsaidov, U. M.; Guchhait, S.; Cambou, A. D.; Cardenas, R.; Park, K.; Markert, J. T.

    2006-03-01

    We report our group's effort in the construction of an 8-T, ^3 He cryostat based nuclear magnetic resonance force microscope (NMRFM). The probe has two independent 3-D of piezoelectric x-y-z positioners for precise positioning of a fiber optic interferometer and a sample/gradient-producing magnet with respect to a micro-cantilever. The piezoelectric positioners have a very uniform controllable step size with virtually no backlash. A novel RF tuning circuit board design is implemented which allows us to simply swap out one RF component board with another for experiments involving different nuclear species. We successfully fabricated and are characterizing 50μm x50μm x0.2μm double torsional oscillators. We have also been characterizing ultrasoft cantilevers whose spring constant is on the order of 10-4 N/m. We also report NMRFM data for ammonium dihydrogen phosphate(ADP) at room temperature using our 1.2-T system. Observed features include the correct shift of the NMR peak with carrier frequency, increases in signal amplitude with both RF field strength and frequency modulation amplitude, and signal oscillation (spin nutation) as a function of tipping RF pulse length. Experiments in progress on NH4MgF3 (at 1.2 T) and MgB2 (at 8.1 T) will also be briefly reviewed. Robert A. Welch Foundation grant No.F-1191 and the National Science Foundation grant No. DMR-0210383.

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

    NARCIS (Netherlands)

    Bank, B.L. van de; Orzada, S.; Smits, F.; Lagemaat, M.W.; Rodgers, C.T.; Bitz, A.K.; Scheenen, T.W.J.

    2015-01-01

    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 consis

  6. Spatial localization in nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Keevil, Stephen F [Department of Medical Physics, Guy' s and St Thomas' NHS Foundation Trust, Guy' s Hospital, London, SE1 9RT (United Kingdom); Division of Imaging Sciences, King' s College London, Guy' s Campus, London, SE1 9RT (United Kingdom)

    2006-08-21

    The ability to select a discrete region within the body for signal acquisition is a fundamental requirement of in vivo NMR spectroscopy. Ideally, it should be possible to tailor the selected volume to coincide exactly with the lesion or tissue of interest, without loss of signal from within this volume or contamination with extraneous signals. Many techniques have been developed over the past 25 years employing a combination of RF coil properties, static magnetic field gradients and pulse sequence design in an attempt to meet these goals. This review presents a comprehensive survey of these techniques, their various advantages and disadvantages, and implications for clinical applications. Particular emphasis is placed on the reliability of the techniques in terms of signal loss, contamination and the effect of nuclear relaxation and J-coupling. The survey includes techniques based on RF coil and pulse design alone, those using static magnetic field gradients, and magnetic resonance spectroscopic imaging. Although there is an emphasis on techniques currently in widespread use (PRESS, STEAM, ISIS and MRSI), the review also includes earlier techniques, in order to provide historical context, and techniques that are promising for future use in clinical and biomedical applications. (topical review)

  7. Nature versus nurture: functional assessment of restoration effects on wetland services using Nuclear Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Sundareshwar, P.V.; Richardson, C.J.; Gleason, R.A.; Pellechia, P.J.; Honomichl, S.

    2009-01-01

    Land-use change has altered the ability of wetlands to provide vital services such as nutrient retention. While compensatory practices attempt to restore degraded wetlands and their functions, it is difficult to evaluate the recovery of soil biogeochemical functions that are critical for restoration of ecosystem services. Using solution 31P Nuclear Magnetic Resonance Spectroscopy, we examined the chemical forms of phosphorus (P) in soils from wetlands located across a land-use gradient. We report that soil P diversity, a functional attribute, was lowest in farmland, and greatest in native wetlands. Soil P diversity increased with age of restoration, indicating restoration of biogeochemical function. The trend in soil P diversity was similar to documented trends in soil bacterial taxonomic composition but opposite that of soil bacterial diversity at our study sites. These findings provide insights into links between ecosystem structure and function and provide a tool for evaluating the success of ecosystem restoration efforts. Copyright 2009 by the American Geophysical Union.

  8. General and hybrid correlation nuclear magnetic resonance analysis of phosphorus in Phytophthora palmivora.

    Science.gov (United States)

    Kirwan, Gemma M; Fernandez, David I; Niere, Julie O; Adams, Michael J

    2012-10-01

    Generalized two-dimensional (Gen2D) correlation analysis and hybrid correlation analysis have been applied to a series of dynamic (31)P nuclear magnetic resonance (NMR) spectra to monitor the in vivo metabolic changes of the plant pathogen Phytophthora palmivora in the presence and absence of phosphonate over an 18-h period. Results indicate that phosphonate exposure causes cleavage in organism polyphosphate chains as well as an increase in total sugar phosphates. In the presence of phosphonate, the NMR resonances attributed to terminal polyphosphate phosphorus reduced at a lower rate than those of middle polyphosphate phosphorus, indicating a change in average chain length and suggesting cleavage in the middle of the chain as well as at the ends. The correlation analysis techniques serve to identify and confirm spectral regions undergoing major change in the time-series data and facilitate the analysis of these dynamic changes.

  9. Solid state 31phosphorus nuclear magnetic resonance of iron-, manganese-, and copper-containing synthetic hydroxyapatites

    Science.gov (United States)

    Sutter, B.; Taylor, R. E.; Hossner, L. R.; Ming, D. W.

    2002-01-01

    The incorporation of micronutrients into synthetic hydroxyapatite (SHA) is proposed for slow release of these nutrients to crops in the National Aeronautics and Space Administration's (NASA's) Advanced Life Support (ALS) program for Lunar or Martian outposts. Solid state 31P nuclear magnetic resonance (NMR) was utilized to examine the paramagnetic effects of Fe3+, Mn2+, and Cu2+ to determine if they were incorporated into the SHA structure. Separate Fe3+, Mn2+, and Cu2+ containing SHA materials along with a transition metal free SHA (pure-SHA) were synthesized using a precipitation method. The proximity (concentrations were incorporated in the SHA structure. Iron-, Mn-, and Cu-containing SHA are potential slow release sources of Fe, Mn, and Cu in the ALS cropping system.

  10. Quantum information processing through nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Bulnes, J.D.; Sarthour, R.S.; Oliveira, I.S. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Bonk, F.A.; Azevedo, E.R. de; Bonagamba, T.J. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica; Freitas, J.C.C. [Espirito Santo Univ., Vitoria, ES (Brazil). Dept. de Fisica

    2005-09-15

    We discuss the applications of Nuclear Magnetic Resonance (NMR) to quantum information processing, focusing on the use of quadrupole nuclei for quantum computing. Various examples of experimental implementation of logic gates are given and compared to calculated NMR spectra and their respective density matrices. The technique of Quantum State Tomography for quadrupole nuclei is briefly described, and examples of measured density matrices in a two-qubit I = 3/2 spin system are shown. Experimental results of density matrices representing pseudo-Bell states are given, and an analysis of the entropy of theses states is made. Considering an NMR experiment as a depolarization quantum channel we calculate the entanglement fidelity and discuss the criteria for entanglement in liquid state NMR quantum information. A brief discussion on the perspectives for NMR quantum computing is presented at the end. (author)

  11. Quantum information processing and nuclear magnetic resonance

    CERN Document Server

    Cummins, H K

    2001-01-01

    as spectrometer pulse sequence programs. Quantum computers are information processing devices which operate by and exploit the laws of quantum mechanics, potentially allowing them to solve problems which are intractable using classical computers. This dissertation considers the practical issues involved in one of the more successful implementations to date, nuclear magnetic resonance (NMR). Techniques for dealing with systematic errors are presented, and a quantum protocol is implemented. Chapter 1 is a brief introduction to quantum computation. The physical basis of its efficiency and issues involved in its implementation are discussed. NMR quantum information processing is reviewed in more detail in Chapter 2. Chapter 3 considers some of the errors that may be introduced in the process of implementing an algorithm, and high-level ways of reducing the impact of these errors by using composite rotations. Novel general expressions for stabilising composite rotations are presented in Chapter 4 and a new class o...

  12. Nuclear magnetic resonance imaging of the spine

    Energy Technology Data Exchange (ETDEWEB)

    Modic, M.T.; Weinstein, M.A.; Pavlicek, W.; Starnes, D.L.; Duchesneau, P.M.; Boumphrey, F.; Hardy, R.J. Jr.

    1984-01-01

    Forty subjects were examined to determine the accuracy and clinical usefulness of nuclear magnetic resonance (NMR) examination of the spine. The NMR images were compared with plain radiographs, high-resolution computed tomograms, and myelograms. The study included 15 patients with normal spinal cord anatomy and 25 patients whose pathological conditions included canal stenosis, herniated discs, metastatic tumors, primary cord tumor, trauma, Chiari malformations, syringomyelia, and developmental disorders. Saturation recovery images were best in differentiating between soft tissue and cerebrospinal fluid. NMR was excellent for the evaluation of the foramen magnum region and is presently the modality of choice for the diagnosis of syringomyelia and Chiari malformation. NMR was accurate in diagnosing spinal cord trauma and spinal canal block.

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

    Science.gov (United States)

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

    2015-04-01

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

  14. Sensitive Magnetic Control of Ensemble Nuclear Spin Hyperpolarisation in Diamond

    CERN Document Server

    Wang, Hai-Jing; Avalos, Claudia E; Seltzer, Scott J; Budker, Dmitry; Pines, Alexander; Bajaj, Vikram S

    2012-01-01

    Dynamic nuclear polarisation, which transfers the spin polarisation of electrons to nuclei, is routinely applied to enhance the sensitivity of nuclear magnetic resonance; it is also critical in spintronics, particularly when spin hyperpolarisation can be produced and controlled optically or electrically. Here we show the complete polarisation of nuclei located near the optically-polarised nitrogen-vacancy (NV) centre in diamond. When approaching the ground-state level anti-crossing condition of the NV electron spins, 13C nuclei in the first-shell are polarised in a pattern that depends sensitively and sharply upon the magnetic field. Based on the anisotropy of the hyperfine coupling and of the optical polarisation mechanism, we predict and observe a complete reversal of the nuclear spin polarisation with a few-mT change in the magnetic field. The demonstrated sensitive magnetic control of nuclear polarisation at room temperature will be useful for sensitivity-enhanced NMR, nuclear-based spintronics, and quant...

  15. Neutron Diffraction Studies of Nuclear Magnetic Ordering in Copper

    DEFF Research Database (Denmark)

    Jyrkkiö, T.A.; Huiku, M.T.; Siemensmeyer, K.;

    1989-01-01

    to depend strongly on the external magnetic field between zero and the critical fieldB c=0.25 mT, indicating the existence of at least two antiferromagnetic phases. The results are compared to previous measurements of the magnetic susceptibility. Theoretical calculations do not provide a full explanation......We have constructed a two-stage nuclear demagnetization cryostat for neutron diffraction studies of nuclear magnetism in copper. The cryostat is combined with a two-axis neutron spectrometer which can use both polarized and unpolarized neutrons. By demagnetizing highly polarized copper nuclear...

  16. Nuclear Composition of Magnetized GRB Jets

    CERN Document Server

    Shibata, Sanshiro

    2015-01-01

    We investigate the fraction of metal nuclei in the relativistic jets of gamma-ray bursts associated with core-collapse supernovae. We simulate the fallback in jet-induced explosions with two-dimensional relativistic hydrodynamics calculations and the jet acceleration with steady, radial, relativistic magnetohydrodynamics calculations, and derive detail nuclear composition of the jet by postprocessing calculation. We found that if the temperature at the jet launch site is above $4.7\\times 10^9$K, quasi-statistical equilibrium (QSE) is established and heavy nuclei are dissociated to light particles such as $^4$He during the acceleration of the jets. The criterion for the survival of metal nuclei is written in terms of the isotropic jet luminosity as $L_{\\rm j}^{\\rm iso} \\lesssim 3.9\\times 10^{50}(R_{\\rm i}/10^7{\\rm cm})^2 (1+\\sigma_{\\rm i})~{\\rm erg~s^{-1}}$, where $R_{\\rm i}$ and $\\sigma_{\\rm i}$ are the initial radius of the jets and the initial magnetization parameter, respectively. If the jet is initially d...

  17. NUCLEAR MAGNETIC RESONANCE STUDIES OF URANOCENES

    Energy Technology Data Exchange (ETDEWEB)

    Luke, Wayne D.; Streitwieser, Jr., Andrew

    1979-12-01

    In the past several years a substantial amount of work has been devoted toward evaluation of the contact and pseudocontact contributions to the observed isotropic shifts in H nuclear magnetic resonance (NMR) spectra of uranium(IV) organometallic compounds. One reason for interest in this area arises from using the presence of contact shifts as a prcbe for covalent character in the uranium carbon bonds in these compounds. Several extensive {sup 1}H NNR studies on Cp{sub 3} U-X compounds and less extensive studies on uranocenes have been reported. Interpretation of these results suggests that contact shifts-contribute significantly to the observed isotropic shifts. Their presence has been taken as indicative of covalent character of metal carbon bonds in these systems, but agreement is not complete. In this paper we shall review critically the work reported on uranocenes in the light of recent results and report recent work on attempted separation of the observed isotropic shifts in alkyluranocenes into contact and pseudocontact components.

  18. Intracellular pH and inorganic phosphate content of heart in vivo: A sup 31 P-NMR study

    Energy Technology Data Exchange (ETDEWEB)

    Katz, L.A.; Swain, J.A.; Portman, M.A.; Balaban, R.S. (National Heart, Lung, and Blood Institute, Bethesda, MD (USA))

    1988-07-01

    Studies were performed to determine the contribution of red blood cells to the {sup 31}P-nuclear magnetic resonance (NMR) spectrum of the canine heart in vivo and the feasibility of measuring myocardial intracellular phosphate and pH. This was accomplished by replacing whole blood with a perfluorochemical perfusion emulsion blood substitute, Oxypherol, and noting the difference in the {sup 31}P-NMR spectrum of the heart. NMR data were collected with a NMR transmitter-receiver coil on the surface of the distal portion of the left ventricle. These studies demonstrated that a small contribution from 2,3-diphosphoglycerate (2,3-DPG) and phosphodiesters in the blood could be detected. The magnitude and shift of these blood-borne signals permitted the relative quantification of intracellular inorganic phosphate (P{sub i}) content as well as intracellular pH. Under resting conditions, the intracellular ATP/P{sub i} was 7.0 {plus minus} 0.08. This corresponds to a free intracellular P{sub 1} content of {approx} 0.8 {mu}mol./g wet wt. The intracellular pH was 7.10 {plus minus} 0.01. Acute respiratory alkalosis and acidosis, with the arterial pH ranging from {approximately}7.0 to 7.7, resulted in only small changes in the intracellular pH. These latter results demonstrate an effective myocardial intracellular proton-buffering mechanism in vivo.

  19. 31P saturation transfer spectroscopy predicts differential intracellular macromolecular association of ATP and ADP in skeletal muscle.

    NARCIS (Netherlands)

    Nabuurs, C.I.H.C.; Huijbregts, B.; Wieringa, B.; Hilbers, C.W.; Heerschap, A.

    2010-01-01

    The kinetics of phosphoryl exchange involving ATP and ADP have been investigated successfully by in vivo (31)P magnetic resonance spectroscopy using magnetization transfer. However, magnetization transfer effects seen on the signals of ATP also could arise from intramolecular cross-relaxation. This

  20. Nuclear magnetic resonance data of C9H11ITe

    Science.gov (United States)

    Mikhova, B. M.

    This document is part of Part 6 `Organic Metalloid Compounds' of Subvolume D 'Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 'Nuclear Magnetic Resonance Data', Group III 'Condensed Matter'.

  1. Nuclear magnetic resonance data of C10H13ITe

    Science.gov (United States)

    Mikhova, B. M.

    This document is part of Part 6 `Organic Metalloid Compounds' of Subvolume D 'Chemical Shifts and Coupling Constants for Carbon-13' of Landolt-Börnstein III/35 'Nuclear Magnetic Resonance Data', Group III 'Condensed Matter'.

  2. Implementation of Quantum Logic Gates by Nuclear Magnetic Resonance Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    DU Jiang-Feng; WU Ji-Hui; SHI Ming-Jun; HAN Liang; ZHOU Xian-Yi; YE Bang-Jiao; WENG Hui-Ming; HAN Rong-Dian

    2000-01-01

    Using nuclear magnetic resonance techniques with a solution of cytosine molecules, we show an implementation of certain quantum logic gates (including NOT gate, square-root of NOT gate and controlled-NOT gate), which have central importance in quantum computing. In addition, experimental results show that nuclear magnetic resonance spectroscopy can efficiently measure the result of quantum computing without attendant wave-function collapse.

  3. Evaluation of mitochondrial function of skeletal muscle in type 2 diabetic patients offspring using dynamic 31p magnetic resonance spectroscopy%磁共振动态磷谱技术评估2型糖尿病患者子女的骨骼肌线粒体功能

    Institute of Scientific and Technical Information of China (English)

    涂慧娟; 吴飞云; 秦斌; 陈婷; 齐静

    2012-01-01

    目的:评价磁共振动态磷谱技术对评估2型糖尿病患者子女骨骼肌能量代谢和线粒体功能的价值.方法:对21名2型糖尿病患者子女和18名健康志愿者的股四头肌进行磁共振动态磷谱检查,获取静息、运动、恢复3个状态的波谱数据.对无机磷(Pi)、磷酸肌酸(PCr)、三磷酸腺苷(ATP)等化合物的峰下面积进行定量分析,通过生化反应平衡公式计算二磷酸腺苷(ADP)和细胞内pH值,并利用指数曲线拟合分析Pi、PCr和ADP的时间常数和恢复速率.结果:糖尿病患者子女组及正常对照组静息期Pi、PCr、ADP、β-ATP的含量及Pi/PCr无统计学差异.运动末期糖尿病患者子女组β-ATP低于正常对照组.恢复期糖尿病患者子女组多帧波谱PCr、β-ATP、pH均低于正常对照组,第3帧Pi/PCr比值比对照组高.恢复期糖尿病患者子女组PCr恢复速率明显低于正常对照组PCr恢复速率.结论:磁共振动态磷谱技术可以无创性检测2型糖尿病患者子女的能量代谢受损及线粒体功能状态.%Objective: To evaluate the energy metabolism and mitochondrial function of skeletal muscle in type 2 diabetic patients offspring using dynamic 31P magnetic resonance spectroscopy(31P-MRS). Methods; Dynamic 31P-MRS was performed on 21 type 2 diabetes patients offsprings and 18 healthy volunteers. Spectra were acquired from quadriceps muscle while subjects were at rest,exercise and recovery. The peak area of inorganic phosphate (Pi),phosphocreatine (PCr) and adenosine triphosphate (ATP) were measured. The concentration of adenosine diphosphate (ADP) and intracellular pH value were calculated from the biochemistry reaction equilibrium. The time constant and recovery rate of PCr,Pi and ADP were analyzed using exponential curve fit. Results; There were no significance differences of Pi,PCr,ADP,β-ATP and the ratio of Pi/PCr between the type 2 diabetes patients offsprings and the healthy volunteers at rest. The type 2

  4. 31P NMR Study on Some Phosphorus-Containing Compounds

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    31P NMR has become a widely applied spectroscopic probe of the structure of phosphorus-containing compounds. Meanwhile, the application of 31P NMR has been rapidly expanded to biochemistry and medicinal chemistry of phosphorus-containing compounds because the growing importance of the phosphorus compounds is now widely realized. We report here the results of 31P NMR study on some phosphorus-containing compounds, namely, O-alkyl O-4-nitrophenyl methyl phosphonates with different alkyl chain-length (MePO-n), 4-nitrophenyl alkylphenylphosphinates with different alkyl chain-length (PhP-n), diethyl phosphono- acetonitrile anion and diethyl phosphite anion . Our results indicate that 31P NMR can not only be applied to not only the study of the hydrolytic reactions of MePO-8 and PhP-8 but also be applied to the study of the presence of the anions of diethylphosphonoacetonitrile and diethyl phosphite in nucleophilic reactions.

  5. Comparison of nuclear electric resonance and nuclear magnetic resonance in integer and fractional quantum Hall states

    Directory of Open Access Journals (Sweden)

    Toru Tomimatsu

    2015-08-01

    Full Text Available Electric-field-induced nuclear resonance (NER: nuclear electric resonance involving quantum Hall states (QHSs was studied at various filling factors by exploiting changes in nuclear spins polarized at quantum Hall breakdown. Distinct from the magnetic dipole interaction in nuclear magnetic resonance, the interaction of the electric-field gradient with the electric quadrupole moment plays the dominant role in the NER mechanism. The magnitude of the NER signal strongly depends on whether electronic states are localized or extended. This indicates that NER is sensitive to the screening capability of the electric field associated with QHSs.

  6. Dynamic nuclear polarization and nuclear magnetic resonance in the simplest pseudospin quantum Hall ferromagnet

    Science.gov (United States)

    Liu, H. W.; Yang, K. F.; Mishima, T. D.; Santos, M. B.; Hirayama, Y.

    2010-12-01

    We present dynamic nuclear polarization (DNP) in the simplest pseudospin quantum Hall ferromagnet (QHF) of an InSb two-dimensional electron gas with a large g factor using tilted magnetic fields. The DNP-induced amplitude change in a resistance spike of the QHF at large current enables observation of the resistively detected nuclear magnetic resonance of the high nuclear spin isotope I115n with nine quadrupole splittings. Our results demonstrate the importance of domain structures in the DNP process. The nuclear spin relaxation time T1 in this QHF was relatively short (˜120s) and almost temperature independent.

  7. Nuclear magnetization in gallium arsenide quantum dots at zero magnetic field.

    Science.gov (United States)

    Sallen, G; Kunz, S; Amand, T; Bouet, L; Kuroda, T; Mano, T; Paget, D; Krebs, O; Marie, X; Sakoda, K; Urbaszek, B

    2014-01-01

    Optical and electrical control of the nuclear spin system allows enhancing the sensitivity of NMR applications and spin-based information storage and processing. Dynamic nuclear polarization in semiconductors is commonly achieved in the presence of a stabilizing external magnetic field. Here we report efficient optical pumping of nuclear spins at zero magnetic field in strain-free GaAs quantum dots. The strong interaction of a single, optically injected electron spin with the nuclear spins acts as a stabilizing, effective magnetic field (Knight field) on the nuclei. We optically tune the Knight field amplitude and direction. In combination with a small transverse magnetic field, we are able to control the longitudinal and transverse components of the nuclear spin polarization in the absence of lattice strain--that is, in dots with strongly reduced static nuclear quadrupole effects, as reproduced by our model calculations.

  8. Nuclear magnetization in gallium arsenide quantum dots at zero magnetic field

    Science.gov (United States)

    Sallen, G.; Kunz, S.; Amand, T.; Bouet, L.; Kuroda, T.; Mano, T.; Paget, D.; Krebs, O.; Marie, X.; Sakoda, K.; Urbaszek, B.

    2014-02-01

    Optical and electrical control of the nuclear spin system allows enhancing the sensitivity of NMR applications and spin-based information storage and processing. Dynamic nuclear polarization in semiconductors is commonly achieved in the presence of a stabilizing external magnetic field. Here we report efficient optical pumping of nuclear spins at zero magnetic field in strain-free GaAs quantum dots. The strong interaction of a single, optically injected electron spin with the nuclear spins acts as a stabilizing, effective magnetic field (Knight field) on the nuclei. We optically tune the Knight field amplitude and direction. In combination with a small transverse magnetic field, we are able to control the longitudinal and transverse components of the nuclear spin polarization in the absence of lattice strain—that is, in dots with strongly reduced static nuclear quadrupole effects, as reproduced by our model calculations.

  9. Pulse Design in Solid-State Nuclear Magnetic Resonance

    DEFF Research Database (Denmark)

    Palani, Ravi Shankar

    2017-01-01

    The work presented in this dissertation is centred on the theory of experimental methods in solid-state Nuclear Magnetic Resonance (NMR) spectroscopy, which deals with interaction of electromagnetic radiation with nuclei in a magnetic field and possessing a fundamental quantum mechanical property...

  10. Nuclear magnetic resonance in environmental engineering: principles and applications.

    NARCIS (Netherlands)

    Lens, P.N.L.; Hemminga, M.A.

    1998-01-01

    This paper gives an introduction to nuclear magnetic resonance spectroscopy (NMR) and magnetic resonance imaging (MRI) in relation to applications in the field of environmental science and engineering. The underlying principles of high resolution solution and solid state NMR, relaxation time measure

  11. Phosphatidylcholine contributes to in vivo {sup 31}P MRS signal from the human liver

    Energy Technology Data Exchange (ETDEWEB)

    Chmelik, Marek; Bogner, Wolfgang; Gajdosik, Martin; Gruber, Stephan; Trattnig, Siegfried [Medical University of Vienna, MR Centre of Excellence, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Valkovic, Ladislav [Medical University of Vienna, MR Centre of Excellence, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Institute of Measurement Science, Slovak Academy of Sciences, Department of Imaging Methods, Bratislava (Slovakia); Wolf, Peter; Krebs, Michael [Medical University of Vienna, Division of Endocrinology and Metabolism, Department of Internal Medicine III, Vienna (Austria); Halilbasic, Emina; Trauner, Michael [Medical University of Vienna, Division of Gastroenterology and Hepatology, Department of Internal Medicine III, Vienna (Austria); Krssak, Martin [Medical University of Vienna, MR Centre of Excellence, Department of Biomedical Imaging and Image-guided Therapy, Vienna (Austria); Medical University of Vienna, Division of Endocrinology and Metabolism, Department of Internal Medicine III, Vienna (Austria)

    2015-07-15

    To demonstrate the overlap of the hepatic and bile phosphorus ({sup 31}P) magnetic resonance (MR) spectra and provide evidence of phosphatidylcholine (PtdC) contribution to the in vivo hepatic {sup 31}P MRS phosphodiester (PDE) signal, suggested in previous reports to be phosphoenolpyruvate (PEP). Phantom measurements to assess the chemical shifts of PEP and PtdC signals were performed at 7 T. A retrospective analysis of hepatic 3D {sup 31}P MR spectroscopic imaging (MRSI) data from 18 and five volunteers at 3 T and 7 T, respectively, was performed. Axial images were inspected for the presence of gallbladder, and PDE signals in representative spectra were quantified. Phantom experiments demonstrated the strong pH-dependence of the PEP chemical shift and proved the overlap of PtdC and PEP (∝2 ppm relative to phosphocreatine) at hepatic pH. Gallbladder was covered in seven of 23 in vivo 3D-MRSI datasets. The PDE{sub gall}/γ-ATP{sub liver} ratio was 4.8-fold higher (p = 0.001) in the gallbladder (PDE{sub gall}/γ-ATP{sub liver} = 3.61 ± 0.79) than in the liver (PDE{sub liver}/γ-ATP{sub liver} = 0.75 ± 0.15). In vivo 7 T {sup 31}P MRSI allowed good separation of PDE components. The gallbladder is a strong source of contamination in adjacent {sup 31}P MR hepatic spectra due to biliary phosphatidylcholine. In vivo {sup 31}P MR hepatic signal at 2.06 ppm may represent both phosphatidylcholine and phosphoenolpyruvate, with a higher phosphatidylcholine contribution due to its higher concentration. (orig.)

  12. Electron transport through nuclear pasta in magnetized neutron stars

    CERN Document Server

    Yakovlev, D G

    2015-01-01

    We present a simple model for electron transport in a possible layer of exotic nuclear clusters (in the so called nuclear pasta layer) between the crust and liquid core of a strongly magnetized neutron star. The electron transport there can be strongly anisotropic and gyrotropic. The anisotropy is produced by different electron effective collision frequencies along and across local symmetry axis in domains of exotic ordered nuclear clusters and by complicated effects of the magnetic field. We also calculate averaged kinetic coefficients in case local domains are freely oriented. Possible applications of the obtained results and open problems are outlined.

  13. Parahydrogen enhanced zero-field nuclear magnetic resonance

    OpenAIRE

    Theis, Thomas; Ganssle, Paul; Kervern, Gwendal; Knappe, Svenja; Kitching, John; Ledbetter, Micah; Budker, Dmitry; Pines, Alex

    2011-01-01

    Nuclear magnetic resonance (NMR), conventionally detected in multi-tesla magnetic fields, is a powerful analytical tool for the determination of molecular identity, structure, and function. With the advent of prepolarization methods and alternative detection schemes using atomic magnetometers or superconducting quantum interference devices (SQUIDs), NMR in very low- (~earth's field), and even zero-field, has recently attracted considerable attention. Despite the use of SQUIDs or atomic magnet...

  14. Low-temperature nuclear magnetic resonance investigation of systems frustrated by competing exchange interactions

    Science.gov (United States)

    Roy, Beas

    This doctoral thesis emphasizes on the study of frustrated systems which form a very interesting class of compounds in physics. The technique used for the investigation of the magnetic properties of the frustrated materials is Nuclear Magnetic Resonance (NMR). NMR is a very novel tool for the microscopic study of the spin systems. NMR enables us to investigate the local magnetic properties of any system exclusively. The NMR experiments on the different systems yield us knowledge of the static as well as the dynamic behavior of the electronic spins. Frustrated systems bear great possibilities of revelation of new physics through the new ground states they exhibit. The vandates AA'VO(PO4)2 [AA' ≡ Zn2 and BaCd] are great prototypes of the J1-J2 model which consists of magnetic ions sitting on the corners of a square lattice. Frustration is caused by the competing nearest-neighbor (NN) and next-nearest neighbor (NNN) exchange interactions. The NMR investigation concludes a columnar antiferromagnetic (AFM) state for both the compounds from the sharp peak of the nuclear spin-lattice relaxation rate (1/T1) and a sudden broadening of the 31P-NMR spectrum. The important conclusion from our study is the establishment of the first H-P-T phase diagram of BaCdVO(PO4)2. Application of high pressure reduces the saturation field (HS) in BaCdVO(PO4)2 and decreases the ratio J2/J1, pushing the system more towards a questionable boundary (a disordered ground state) between the columnar AFM and a ferromagnetic ground state. A pressure up to 2.4 GPa will completely suppress HS. The Fe ions in the `122' iron-arsenide superconductors also sit on a square lattice thus closely resembling the J1-J2 model. The 75As-NMR and Nuclear Quadrupole Resonance (NQR) experiments are conducted in the compound CaFe2As2 prepared by two different heat treatment methods (`as-grown' and `annealed'). Interestingly the two samples show two different ground states. While the ground state of the `as

  15. The Fourier Transform in Chemistry. Part 1. Nuclear Magnetic Resonance: Introduction.

    Science.gov (United States)

    King, Roy W.; Williams, Kathryn R.

    1989-01-01

    Using fourier transformation methods in nuclear magnetic resonance has made possible increased sensitivity in chemical analysis. This article describes these methods as they relate to magnetization, the RF magnetic field, nuclear relaxation, the RF pulse, and free induction decay. (CW)

  16. Development of Nuclear Magnetic Resonance Pulse Sequences and Probes to Study Biomacromolecules

    Energy Technology Data Exchange (ETDEWEB)

    Cosman, M; Krishnan, V V; Maxwell, R

    2001-02-26

    The determination of the three dimensional structures at high resolution of biomolecules, such as proteins and nucleic acids, enables us to understand their function at the molecular level. At the present time, there are only two methods available for determining such structures, nuclear magnetic resonance (NMR) spectroscopy and X-ray diffraction. Compared to well-established X-ray diffraction techniques, NMR methodology is relatively new and has many areas in which improvement can still be attained. In this project, we focused on the development of new NMR probes and pulse sequences that were tailored to tackle specific problems that are not adequately addressed by current technology. Probes are the hardware that contain the radio frequency (RF) circuitry used to both excite and detect the NMR signals. Pulse sequences are composed of a series of RF pulses and delays, which are applied to the sample held within the magnetic field by the probe, so as to manipulate the nuclear spins. Typically, a probe is developed for a specific set of nuclei and types of experiments and the pulse sequences are then written to use the probe in an optimal manner. In addition, the inter-development of instrumentation and methods are determined by the specific biological question to be examined. Thus our efforts focused on addressing an area of importance in NMR Structural Biology namely more effective ways to use the phosphorus ({sup 31}P) nucleus. Phosphorus is a very important biological element that is strategically located in nucleic acids, where it imparts negative charge and flexibility to RNA and DNA. It is also a component of the cellular membrane and thus interacts with membrane proteins. It is used in mechanisms to signal, activate or deactivate enzymes; and participates in energy storage and release. However, the phosphorus nucleus exhibits certain properties, such as poor spectral dispersion, low sensitivity of detection, and fast relaxation, which limit its effective use

  17. Assessment of preparation methods for organic phosphorus analysis in phosphorus-polluted Fe/Al-rich Haihe river sediments using solution 31P-NMR.

    Directory of Open Access Journals (Sweden)

    Wenqiang Zhang

    Full Text Available 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.

  18. The use of {sup 1}H-{sup 31}P GHMBC and covariance NMR to unambiguously determine phosphate ester linkages in complex polysaccharide mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Zartler, Edward R., E-mail: teddyzartler@gmail.com [Merck Research Labs, Merck and Co., Vaccine Analytical Development (United States); Martin, Gary E. [Merck Research Labs, Merck and Co., Structure Elucidation Group (United States)

    2011-11-15

    Poly- and oligo-saccharides are commonly employed as antigens in many vaccines. These antigens contain phosphoester structural elements that are crucial to the antigenicity, and hence the effectiveness of the vaccine. Nuclear Magnetic Resonance (NMR) is a powerful tool for the site-specific identification of phosphoesters in saccharides. We describe here two advances in the characterization of phosphoesters in saccharides: (1) the use of {sup 1}H-{sup 31}P GHMBC to determine the site-specific identity of phosphoester moieties in heterogeneous mixtures and (2) the use of Unsymmetrical/Generalized Indirect Covariance (U/GIC) to calculate a carbon-phosphorus 2D spectrum. The sensitivity of the {sup 1}H-{sup 31}P GHMBC is far greater than the 'standard' {sup 1}H-{sup 31}P GHSQC and allows long-range {sup 3-5}J{sub HP} couplings to be readily detected. This is the first example to be reported of using U/GIC to calculate a carbon-phosphorus spectrum. The U/GIC processing affords, in many cases, a fivefold to tenfold or greater increase in signal-to-noise ratios in the calculated spectrum. When coupled with the high sensitivity of {sup 1}H-{sup 31}P HMBC, U/GIC processing allows the complete and unambiguous assignments of phosphoester moieties present in heterogeneous samples at levels of {approx}5% (or less) of the total sample, expanding the breadth of samples that NMR can be used to analyze. This new analytical technique is generally applicable to any NMR-observable phosphoester.

  19. Capacitor-based detection of nuclear magnetization: nuclear quadrupole resonance of surfaces.

    Science.gov (United States)

    Gregorovič, Alan; Apih, Tomaž; Kvasić, Ivan; Lužnik, Janko; Pirnat, Janez; Trontelj, Zvonko; Strle, Drago; Muševič, Igor

    2011-03-01

    We demonstrate excitation and detection of nuclear magnetization in a nuclear quadrupole resonance (NQR) experiment with a parallel plate capacitor, where the sample is located between the two capacitor plates and not in a coil as usually. While the sensitivity of this capacitor-based detection is found lower compared to an optimal coil-based detection of the same amount of sample, it becomes comparable in the case of very thin samples and even advantageous in the proximity of conducting bodies. This capacitor-based setup may find its application in acquisition of NQR signals from the surface layers on conducting bodies or in a portable tightly integrated nuclear magnetic resonance sensor.

  20. Magnet Design Considerations for Fusion Nuclear Science Facility

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Y. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Kessel, C. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); El-Guebaly, L. [Univ. of Wisconsin, Madison, WI (United States) Fusion Technology Institute; Titus, P. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

    2016-06-01

    The Fusion Nuclear Science Facility (FNSF) is a nuclear confinement facility that provides a fusion environment with components of the reactor integrated together to bridge the technical gaps of burning plasma and nuclear science between the International Thermonuclear Experimental Reactor (ITER) and the demonstration power plant (DEMO). Compared with ITER, the FNSF is smaller in size but generates much higher magnetic field, i.e., 30 times higher neutron fluence with three orders of magnitude longer plasma operation at higher operating temperatures for structures surrounding the plasma. Input parameters to the magnet design from system code analysis include magnetic field of 7.5 T at the plasma center with a plasma major radius of 4.8 m and a minor radius of 1.2 m and a peak field of 15.5 T on the toroidal field (TF) coils for the FNSF. Both low-temperature superconductors (LTS) and high-temperature superconductors (HTS) are considered for the FNSF magnet design based on the state-of-the-art fusion magnet technology. The higher magnetic field can be achieved by using the high-performance ternary restacked-rod process Nb3Sn strands for TF magnets. The circular cable-in-conduit conductor (CICC) design similar to ITER magnets and a high-aspect-ratio rectangular CICC design are evaluated for FNSF magnets, but low-activation-jacket materials may need to be selected. The conductor design concept and TF coil winding pack composition and dimension based on the horizontal maintenance schemes are discussed. Neutron radiation limits for the LTS and HTS superconductors and electrical insulation materials are also reviewed based on the available materials previously tested. The material radiation limits for FNSF magnets are defined as part of the conceptual design studies for FNSF magnets.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1987-05-01

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

  2. {sup 31}P-MR spectroscopy in children and adolescents with a familial risk of schizophrenia

    Energy Technology Data Exchange (ETDEWEB)

    Rzanny, R.; Reichenbach, J.R.; Pfleiderer, S.O.R.; Kaiser, W.A. [Institut fuer Diagnostische und Interventionelle Radiologie, Abteilung MT, Klinikum der Friedrich-Schiller-Universitaet Jena, Philosophenweg 3, 07741 Jena (Germany); Klemm, S.; Blanz, B. [Klinik fuer Kinder- und Jugendpsychiatrie, Klinikum der Friedrich-Schiller-Universitaet Jena, Bachstrasse 18, 07741 Jena (Germany); Schmidt, B.; Volz, H.-P. [Klinik fuer Psychiatrie, Klinikum der Friedrich-Schiller-Universitaet Jena, Bachstrasse 18, 07741 Jena (Germany)

    2003-04-01

    Based on a previous report [9] on alterations of membrane phosphorus metabolism in asymptomatic family members of schizophrenic patients, the aim of the present study was to extend and improve the evaluation and data processing of {sup 31}P spectroscopic data obtained from a larger study population by including an analysis of the broad spectral component (BC) of membrane phospholipids (PL). Eighteen children and siblings of patients with schizophrenia and a gender- and age-matched control group of 18 healthy subjects without familial schizophrenia were investigated with phosphorus magnetic resonance spectroscopy ({sup 31}P-MRS) by using image selected in vivo spectroscopy (ISIS) in the dorsolateral prefrontal regions (DLPFR) of the brain. Spectral analysis was performed by using both the full and truncated FID to estimate metabolic peak ratios of different {sup 31}P metabolites and the intensity and linewidth of the broad component. A significantly higher PDE level (p<0.01) and increased linewidth of the PDE components were observed for the high-risk group compared with the control group (p=0.02). No significant differences were observed for PME as well as for other {sup 31}P-metabolites. No differences were observed between the left and right hemispheres for different normalised {sup 31}P-metabolic levels. Decreased intensities (p=0.03) and smaller linewidths (p=0.01) were obtained for the broad component in the high-risk group. Impairments of membrane metabolism that are typical for schizophrenic patients are partially observed in adolescent asymptomatic family members of schizophrenics, including increased levels of low molecular PDE compounds indicating increased membrane degradation processes, no changes for PME, and decreased intensities and linewidths of the BC indicating changes in the composition and fluidity of membrane phospholipids. Despite limitations to completely suppress fast-relaxing components by dismissing initial FID data points, the

  3. Importance of the 31-p-nmr-spectroscopy for prediction and early detection of coronary heart disease in patients with diabetes mellitus type I

    CERN Document Server

    Steinboeck, P

    2001-01-01

    Microvascular abnormalities and dysfunction via thickening of the basement membrane are known to occur in diabetic patients. Myocardial high energy phosphates have been shown to be reduced by ischemia and alterations of the cardiac metabolism are the primary consequence of myocardial ischemia. The present study involved 30 male patients with diabetes mellitus type I and 36 healthy male volunteers as age-matched controls. Phosphorus-31-P-nuclear-magnetic-resonance-spectroscopic-imaging of the heart was performed in all subjects using a 1.5 Tesla whole-body-magnetic-resonance-scanner. The ratios of phosphocreatinine (PCr) to adenosine-triphosphate (ATP) were calculated. Moreover, echocardiographic evaluation and stress tests were performed in all individuals. The myocardium of patients with diabetes mellitus type I showed significantly decreased ratios of PCr/ATP compared with healthy controls. This study demonstrates for the first time a decreased ratio of PCr/ATP in the myocardium of patients with diabetes me...

  4. Nuclear magnetic resonance in environmental engineering: principles and applications.

    Science.gov (United States)

    Lens, P N; Hemminga, M A

    1998-01-01

    This paper gives an introduction to nuclear magnetic resonance spectroscopy (NMR) and magnetic resonance imaging (MRI) in relation to applications in the field of environmental science and engineering. The underlying principles of high resolution solution and solid state NMR, relaxation time measurements and imaging are presented. Then, the use of NMR is illustrated and reviewed in studies of biodegradation and biotransformation of soluble and solid organic matter, removal of nutrients and xenobiotics, fate of heavy metal ions, and transport processes in bioreactor systems.

  5. Evaluation of nuclear magnetic resonance spectroscopy variability

    Energy Technology Data Exchange (ETDEWEB)

    Barreto, Felipe Rodrigues; Salmon, Carlos Ernesto Garrido, E-mail: garrido@ffclrp.usp.br [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Filisofia, Ciencias e Letras; Otaduy, Maria Concepcion Garcia [Universidade de Sao Paulo (FAMUS/USP), Sao Paulo, SP (Brazil). Fac. de Medicina. Departamento de Radiologia

    2014-11-01

    Introduction: the intrinsically high sensitivity of Magnetic Resonance Spectroscopy (MRS) causes considerable variability in metabolite quantification. In this study, we evaluated the variability of MRS in two research centers using the same model of magnetic resonance image scanner. Methods: two metabolic phantoms were created to simulate magnetic resonance spectra from in vivo hippocampus. The phantoms were filled with the same basic solution containing the following metabolites: N-acetyl-aspartate, creatine, choline, glutamate, glutamine and inositol. Spectra were acquired over 15 months on 26 acquisition dates, resulting in a total of 130 spectra per center. Results: the phantoms did not undergo any physical changes during the 15-month period. Temporal analysis from both centers showed mean metabolic variations of 3.7% in acquisitions on the same day and of 8.7% over the 15-month period. Conclusion: The low deviations demonstrated here, combined with the high specificity of Magnetic Resonance Spectroscopy, confirm that it is feasible to use this technique in multicenter studies in neuroscience research. (author)

  6. High Radiation Environment Nuclear Fragment Separator Magnet

    Energy Technology Data Exchange (ETDEWEB)

    Kahn, Stephen [Muons, Inc., Batavia, IL (United States); Gupta, Ramesh [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-01-31

    Superconducting coils wound with HTS conductor can be used in magnets located in a high radiation environment. NbTi and Nb3Sn superconductors must operate at 4.5 K or below where removal of heat is less efficient. The HTS conductor can carry significant current at higher temperatures where the Carnot efficiency is significantly more favorable and where the coolant heat capacity is much larger. Using the HTS conductor the magnet can be operated at 40 K. This project examines the use of HTS conductor for the Michigan State University Facility For Rare Isotope Beams (FRIB) fragment separator dipole magnet which bends the beam by 30° and is located in a high radiation region that will not be easily accessible. Two of these magnets are needed to select the chosen isotope. There are a number of technical challenges to be addressed in the design of this magnet. The separator dipole is 2 m long and subtends a large angle. The magnet should keep a constant transverse field profile along its beam reference path. Winding coils with a curved inner segment is difficult as the conductor will tend to unwind during the process. In the Phase I project two approaches to winding the conductor were examined. The first was to wind the coils with curved sections on the inner and outer segments with the inner segment wound with negative curvature. The alternate approach was to use a straight segment on the inner segment to avoid negative curvature. In Phase I coils with a limited number of turns were successfully wound and tested at 77 K for both coil configurations. The Phase II program concentrated on the design, coil winding procedures, structural analysis, prototyping and testing of an HTS curved dipole coil at 40 K with a heat load representative of the radiation environment. One of the key criteria of the design of this magnet is to avoid the use of organic materials that would degrade rapidly in radiation. The Lorentz forces expected from the coils interacting with the

  7. DC SQUID Spectrometers for Nuclear Quadrupole and Low-Field Nuclear Magnetic Resonance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    TonThat, Dinh M. [Univ. of California, Berkeley, CA (United States)

    1998-04-01

    The dc Superconducting Quantum Interference Device (SQUJD) is a very sensitive detector of magnetic flux, with a typical flux noise of the order of 1 μΦ0Hz-1/2 at liquid helium temperature (Φ0=h/2e). This inherent flux sensitivity of the SQUID is used in a spectrometer for the detection of nuclear magnetic resonance (NMR.)and nuclear quadruple resonance (NQR). The processing magnetic field from the nuclear spins is coupled to the SQUID by mean of a flux transformer. The SQUID NMR spectrometer is used to measure the longitudinal relaxation time T1 of solid 129Xe at 4.2 K down to 0.1 mT.

  8. Zero-Field Nuclear Magnetic Resonance

    OpenAIRE

    Weitekamp, D.P.; Bielecki, A.; Zax, D.; Zilm, K.; Pines, A.

    1983-01-01

    In polycrystalline samples, NMR "powder spectra" are broad and much structural information is lost as a result of the orientational disorder. In this Letter Fourier-transform NMR in zero magnetic field is described. With no preferred direction in space, all crystallites contribute equivalently and resolved dipolar splittings can be interpreted directly in terms of internuclear distances. This opens the possiblity of molecular structure determination without the need for single crystals or ori...

  9. Zero-field nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Weitekamp, D.P.; Bielecki, A.; Zax, D.; Zilm, K.; Pines, A.

    1983-05-30

    In polycrystalline samples, NMR ''powder spectra'' are broad and much structural information is lost as a result of the orientational disorder. In this Letter Fourier transform NMR in zero magnetic field is described. With no preferred direction in space, all crystallites contribute equivalently and resolved dipolar splittings can be interpreted directly in terms of internuclear distances. This opens the possibility of molecular structure determination without the need for single crystals or oriented samples.

  10. Realization of a Quantum Scheduling Algorithm Using Nuclear Magnetic Resonance

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jing-Fu; DENG Zhi-Wei; PAN Yan-Na; LU Zhi-Heng

    2004-01-01

    The quantum scheduling algorithm proposed by Grover is generalized to extend its scope of applications. The generalized algorithm proposed here is realized on a nuclear magnetic resonance quantum computer. The experimental results show that the generalized algorithm can work efficiently in the case that Grover's scheduling algorithm is completely invalid, and represent the quantum advantages when qubits replace classical bits.

  11. Nuclear magnetic resonance imaging of water motion in plants

    NARCIS (Netherlands)

    Scheenen, T.W.J.

    2001-01-01

    This Thesis treats one of the new techniques in plant science i.e. nuclear magnetic resonance imaging (NMRi) applied to water motion in plants. It is a challenge, however, to measure this motion in intact plants quantitatively, because plants impose specific problems when studied using

  12. NMR of TMV. Nuclear magnetic resonance of tobacco mosaic virus

    NARCIS (Netherlands)

    Wit, de J.L.

    1978-01-01

    This Thesis describes the application of conventional 13 C and 1 H high resolution Fourier Transform Nuclear Magnetic resonance (HR FT NMR) to Tobacco Mosaic Virus (TMV) and its protein oligo- and polymers and some other largebiological systems. The rod-like (TMV) consists of 2

  13. Neutron studies of nuclear magnetism at ultralow temperature

    DEFF Research Database (Denmark)

    Siemensmeyer, K.; Clausen, K.N.; Lefmann, K.

    1998-01-01

    Nuclear magnetic order in copper and silver has been investigated by neutron diffraction. Antiferromagnetic order is observed in these simple, diamagnetic metals at temperatures below 50 nK and 560 pK, respectively. Both crystallize in the FCC-symmetry which is fully frustrated for nearest...

  14. Using Nuclear Magnetic Resonance Spectroscopy for Measuring Ternary Phase Diagrams

    Science.gov (United States)

    Woodworth, Jennifer K.; Terrance, Jacob C.; Hoffmann, Markus M.

    2006-01-01

    A laboratory experiment is presented for the upper-level undergraduate physical chemistry curriculum in which the ternary phase diagram of water, 1-propanol and n-heptane is measured using proton nuclear magnetic resonance (NMR) spectroscopy. The experiment builds upon basic concepts of NMR spectral analysis, typically taught in the undergraduate…

  15. Nuclear magnetic response imaging of sap flow in plants

    NARCIS (Netherlands)

    Windt, C.W.

    2007-01-01

    This thesis deals with Nuclear Magnetic Resonance (NMR) imaging of long distance transport in plants. Long distance transport in plants is an enigmatic process. The theoretical framework that describes its basic properties has been in place for almost a century, yet at the same time only little is

  16. Nuclear magnetic resonance imaging of water motion in plants

    NARCIS (Netherlands)

    Scheenen, T.W.J.

    2001-01-01

    This Thesis treats one of the new techniques in plant science i.e. nuclear magnetic resonance imaging (NMRi) applied to water motion in plants. It is a challenge, however, to measure this motion in intact plants quantitatively, because plants impose specific problems when studied using NMRi. At high

  17. 13. Nuclear magnetic resonance users meeting. Extended abstracts book

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This annual meeting, held in Brazil from May 2 - 6, 2011 comprised seventeen lectures, given by invited speakers from Brazil and other countries, about the use of nuclear magnetic resonance for various analytical purposes; results from ninety five research works, most being carried out by scientific groups from various Brazilian R and D institutions, presented as congress panels/posters. A General Assembly meeting of AUREMN, the Brazilian Association of Nuclear Magnetic Resonance Users, also took place during the event. Main topics of the research works presented at this meeting were thus distributed: 54% in analytical chemistry (mainly organic chemistry, both experimental and theoretical works), 18% in applied life sciences (agricultural and food sciences, biological sciences and medicine), 15% in materials science (including nanostructures, petroleum and alternative fuels), 10% in mathematical methods and computing for the interpretation of NMR data, and the remaining 3% in improvements in instrumentation interfaces or magnetic field configurations.

  18. In vivo ³¹P-nuclear magnetic resonance studies of glyphosate uptake, vacuolar sequestration, and tonoplast pump activity in glyphosate-resistant horseweed.

    Science.gov (United States)

    Ge, Xia; d'Avignon, D André; Ackerman, Joseph J H; Sammons, R Douglas

    2014-11-01

    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. (31)P-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. (31)P-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.

  19. Development of a miniature permanent magnetic circuit for nuclear magnetic resonance chip

    Science.gov (United States)

    Lu, Rongsheng; Yi, Hong; Wu, Weiping; Ni, Zhonghua

    2013-07-01

    The existing researches of miniature magnetic circuits focus on the single-sided permanent magnetic circuits and the Halbach permanent magnetic circuits. In the single-sided permanent magnetic circuits, the magnetic flux density is always very low in the work region. In the Halbach permanent magnetic circuits, there are always great difficulties in the manufacturing and assembly process. The static magnetic flux density required for nuclear magnetic resonance(NMR) chip is analyzed based on the signal noise ratio(SNR) calculation model, and then a miniature C-shaped permanent magnetic circuit is designed as the required magnetic flux density. Based on Kirchhoff's law and magnetic flux refraction principle, the concept of a single shimming ring is proposed to improve the performance of the designed magnetic circuit. Using the finite element method, a comparative calculation is conducted. The calculation results demonstrate that the magnetic circuit improved with a single shimming has higher magnetic flux density and better magnetic field homogeneity than the one improved with no shimming ring or double shimming rings. The proposed magnetic circuit is manufactured and its experimental test platform is also built. The magnetic flux density measured in the work region is 0.7 T, which is well coincided with the theoretical design. The spatial variation of the magnetic field is within the range of the instrument error. At last, the temperature dependence of the magnetic flux density produced by the proposed magnetic circuit is investigated through both theoretical analysis and experimental study, and a linear functional model is obtained. The proposed research is crucial for solving the problem in the application of NMR-chip under different environmental temperatures.

  20. Unconventional nuclear magnetic resonance techniques using nanostructured diamond surfaces

    Science.gov (United States)

    Acosta, Victor; Jarmola, Andrey; Budker, Dmitry; Santori, Charles; Huang, Zhihong; Beausoleil, Raymond

    2014-03-01

    Nuclear magnetic resonance (NMR) technologies rely on obtaining high nuclear magnetization, motivating low operating temperatures and high magnetic fields. Dynamic nuclear polarization (DNP) techniques traditionally require another superconducting magnet and THz optics. We seek to use chip-scale devices to polarize nuclei in liquids at room temperature. The technique relies on optical pumping of nitrogen-vacancy (NV) centers and subsequent transfer of polarization to nuclei via hyperfine interaction, spin diffusion, and heteronuclear polarization transfer. We expect efficient polarization transfer will be realized by maximizing the diamond surface area. We have fabricated densely-packed (50 % packing fraction), high-aspect-ratio (10+) nanopillars over mm2 regions of the diamond surface. Pillars designed to have a few-hundred-nanometer diameter act as optical antennas, reducing saturation intensity. We also report progress in using nanopillar arrays as sensitive optical detectors of nano-scale NMR by measuring NV center Zeeman shifts produced by nearby external nuclei. The enhanced surface area increases the effective density of NV centers which couple to external nuclei. Combining these techniques may enable, e.g., identification of trace analytes and molecular imaging.

  1. Structural studies of A-form sodium deoxyribonucleic acid: phosphorus-31 nuclear magnetic resonance of oriented fibers.

    Science.gov (United States)

    Nall, B T; Rothwell, W P; Waugh, J S; Rupprecht, A

    1981-03-31

    A highly oriented sample of A-form sodium deoxyribonucleic acid (DNA) has been investigated by using proton-enhanced 31P nuclear magnetic resonance (NMR). Proton-decoupled spectra taken with different angles between the magnetic field direction and the fiber direction are compared to theoretical spectra which are calculated by assuming the following: (1) the orientation of the phosphate groups in the fiber is given by the A-form DNA coordinates suggested by Arnott & Hukins [Arnott, S., & Hukins, D. W. L. (1972) Biochem. Biophys. Res. Commun. 47, 1504-1509]; (2) the DNA phosphate groups may be considered stationary on the NMR time scale; (3) the relevant features of the spectra are determined solely by chemical shift anisotropy of the phosphorus atoms. The experimental and calculated spectra are in excellent agreement and support the validity of the above assumptions contrary to conclusions drawn in another investigation [Shindo, H., Wooton, J. B., Pheiffer, B. H., & Zimmerman, S. B. (1980) Biochemistry 19, 518-526]. In particular, we find no evidence to support the notion of a highly irregular phosphodiester backbone. Comparison of observed and simulated spectra allows the determination of the orientation of the 31P chemical shielding tensor relative to the bonding framework of the phosphodiester group. The orientation agrees with that expected from NMR studies of phosphodiester model compounds [Kohler, S. J., & Klein, M. P. (1976) Biochemistry 15, 967-973; Herzfeld, J., Griffin, R. G., & Haberkorn, R. A. (1978) Biochemistry 17, 2711-2718] and X-ray diffraction of oriented fibers [Arnott, S., & Hukins, D. W. L. (1972) Biochem. Biophys. Res. Commun. 47, 1504-1509].

  2. Nuclear magnetic and quadrupole resonance studies of the stripes materials

    Energy Technology Data Exchange (ETDEWEB)

    Grafe, H.-J., E-mail: h.grafe@ifw-dresden.de [IFW Dresden, Institute for Solid State Research, P.O. Box 270116, D-01171 Dresden (Germany)

    2012-11-01

    Nuclear Magnetic and Quadrupole Resonance (NMR/NQR) is a powerful tool to probe electronic inhomogeneities in correlated electron systems. Its local character allows for probing different environments due to spin density modulations or inhomogeneous doping distributions emerging from the correlations in these systems. In fact, NMR/NQR is not only sensitive to magnetic properties through interaction of the nuclear spin, but also allows to probe the symmetry of the charge distribution and its homogeneity, as well as structural modulations, through sensitivity to the electric field gradient (EFG). We review the results of NMR and NQR in the cuprates from intrinsic spatial variations of the hole concentration in the normal state to stripe order at low temperatures, thereby keeping in mind the influence of doping induced disorder and inhomogeneities. Finally, we briefly discuss NQR evidence for local electronic inhomogeneities in the recently discovered iron pnictides, suggesting that electronic inhomogeneities are a common feature of correlated electron systems.

  3. Observation of nuclear magnetic order in solid 3He

    DEFF Research Database (Denmark)

    Halperin, W.P.; Archie, C.N.; Rasmussen, Finn Berg

    1974-01-01

    Measurements of T dp/dT have been made along the He3 melting curve near an anomaly at Ts=1.17 mK. It is found that the solid-He3 entropy decreases by 80% in an interval of 100 μK at Ts. This is attributed to onset of nuclear magnetic order.......Measurements of T dp/dT have been made along the He3 melting curve near an anomaly at Ts=1.17 mK. It is found that the solid-He3 entropy decreases by 80% in an interval of 100 μK at Ts. This is attributed to onset of nuclear magnetic order....

  4. Advances in Zero-Field Nuclear Magnetic Resonance Spectroscopy

    OpenAIRE

    Theis, Thomas

    2012-01-01

    In the course of the last century, Nuclear magnetic resonance (NMR) has become a powerful and ubiquitous analytical tool for the determination of molecular identity, structure, and function. Traditionally, the great analytical power of NMR comes at the cost of mobility and large expenses for cryogenic cooling. This thesis presents how zero-field NMR detected with an atomic magnetometer is emerging as a new, potentially portable and cost-effective modality of NMR with the ability of providing ...

  5. A Multidisciplinary Approach to High Throughput Nuclear Magnetic Resonance Spectroscopy

    OpenAIRE

    Hossein Pourmodheji; Ebrahim Ghafar-Zadeh; Sebastian Magierowski

    2016-01-01

    Nuclear Magnetic Resonance (NMR) is a non-contact, powerful structure-elucidation technique for biochemical analysis. NMR spectroscopy is used extensively in a variety of life science applications including drug discovery. However, existing NMR technology is limited in that it cannot run a large number of experiments simultaneously in one unit. Recent advances in micro-fabrication technologies have attracted the attention of researchers to overcome these limitations and significantly accelera...

  6. Demonstration of Quantum Entanglement Control Using Nuclear Magnetic Resonance

    Institute of Scientific and Technical Information of China (English)

    XIE Jing-Yi; ZHANG Jing-Fu; DENG Zhi-Wei; LU Zhi-Heng

    2004-01-01

    @@ With the two forms of the quantum entanglement control, the quantum entanglement swapping and preservation are demonstrated in a three-qubit nuclear magnetic resonance quantum computer. The pseudopure state is prepared to represent the quantum entangled states through macroscopic signals. Entanglement swapping is directly realized by a swap operation. By controlling the interactions between the system and its environment,we can preserve an initial entangled state for a longer time. The experimental results are in agreement with the experiment.

  7. Analysis of the transient response of nuclear spins in GaAs with/without nuclear magnetic resonance

    Science.gov (United States)

    Rasly, Mahmoud; Lin, Zhichao; Yamamoto, Masafumi; Uemura, Tetsuya

    2016-05-01

    As an alternative to studying the steady-state responses of nuclear spins in solid state systems, working within a transient-state framework can reveal interesting phenomena. The response of nuclear spins in GaAs to a changing magnetic field was analyzed based on the time evolution of nuclear spin temperature. Simulation results well reproduced our experimental results for the transient oblique Hanle signals observed in an all-electrical spin injection device. The analysis showed that the so called dynamic nuclear polarization can be treated as a cooling tool for the nuclear spins: It works as a provider to exchange spin angular momentum between polarized electron spins and nuclear spins through the hyperfine interaction, leading to an increase in the nuclear polarization. In addition, a time-delay of the nuclear spin temperature with a fast sweep of the external magnetic field produces a possible transient state for the nuclear spin polarization. On the other hand, the nuclear magnetic resonance acts as a heating tool for a nuclear spin system. This causes the nuclear spin temperature to jump to infinity: i.e., the average nuclear spins along with the nuclear field vanish at resonant fields of 75As, 69Ga and 71Ga, showing an interesting step-dip structure in the oblique Hanle signals. These analyses provide a quantitative understanding of nuclear spin dynamics in semiconductors for application in future computation processing.

  8. Analysis of the transient response of nuclear spins in GaAs with/without nuclear magnetic resonance

    Directory of Open Access Journals (Sweden)

    Mahmoud Rasly

    2016-05-01

    Full Text Available As an alternative to studying the steady-state responses of nuclear spins in solid state systems, working within a transient-state framework can reveal interesting phenomena. The response of nuclear spins in GaAs to a changing magnetic field was analyzed based on the time evolution of nuclear spin temperature. Simulation results well reproduced our experimental results for the transient oblique Hanle signals observed in an all-electrical spin injection device. The analysis showed that the so called dynamic nuclear polarization can be treated as a cooling tool for the nuclear spins: It works as a provider to exchange spin angular momentum between polarized electron spins and nuclear spins through the hyperfine interaction, leading to an increase in the nuclear polarization. In addition, a time-delay of the nuclear spin temperature with a fast sweep of the external magnetic field produces a possible transient state for the nuclear spin polarization. On the other hand, the nuclear magnetic resonance acts as a heating tool for a nuclear spin system. This causes the nuclear spin temperature to jump to infinity: i.e., the average nuclear spins along with the nuclear field vanish at resonant fields of 75As, 69Ga and 71Ga, showing an interesting step-dip structure in the oblique Hanle signals. These analyses provide a quantitative understanding of nuclear spin dynamics in semiconductors for application in future computation processing.

  9. Oxidative stress-induced metabolic changes in mouse C2C12 myotubes studied with high-resolution 13C, 1H, and 31P NMR spectroscopy

    DEFF Research Database (Denmark)

    Straadt, Ida K; Young, Jette F; Petersen, Bent O;

    2010-01-01

    In this study, stress in relation to slaughter was investigated in a model system by the use of (13)C, (1)H, and (31)P nuclear magnetic resonance (NMR) spectroscopy for elucidating changes in the metabolites in C2C12 myotubes exposed to H(2)O(2)-induced stress. Oxidative stress resulted in lower...... to lower levels of the unlabeled ((12)C) lactate were identified in the (1)H spectra after stress exposure. These data indicate an increase in de novo synthesis of alanine, concomitant with a release of lactate from the myotubes to the medium at oxidative stress conditions. The changes in the metabolite...... levels of several metabolites, mainly amino acids; however, higher levels of alanine were apparent in the (13)C spectra after incubation with [(13)C(1)]glucose. In the (13)C spectra [(13)C(3)]lactate tended to increase after exposure to increasing concentrations of H(2)O(2); conversely, a tendency...

  10. Quantitative 31P NMR for Simultaneous Trace Analysis of Organophosphorus Pesticides in Aqueous Media Using the Stir Bar Sorptive Extraction Method

    Science.gov (United States)

    Ansari, S.; Talebpour, Z.; Molaabasi, F.; Bijanzadeh, H. R.; Khazaeli, S.

    2016-09-01

    The analysis of pesticides in water samples is of primary concern for quality control laboratories due to the toxicity of these compounds and their associated public health risk. A novel analytical method based on stir bar sorptive extraction (SBSE), followed by 31P quantitative nuclear magnetic resonance (31P QNMR), has been developed for simultaneously monitoring and determining four organophosphorus pesticides (OPPs) in aqueous media. The effects of factors on the extraction efficiency of OPPs were investigated using a Draper-Lin small composite design. An optimal sample volume of 4.2 mL, extraction time of 96 min, extraction temperature of 42°C, and desorption time of 11 min were obtained. The results showed reasonable linearity ranges for all pesticides with correlation coefficients greater than 0.9920. The limit of quantification (LOQ) ranged from 0.1 to 2.60 mg/L, and the recoveries of spiked river water samples were from 82 to 94% with relative standard deviation (RSD) values less than 4%. The results show that this method is simple, selective, rapid, and can be applied to other sample matrices.

  11. Distribution and mobility of phosphates and sodium ions in cheese by solid-state 31P and double-quantum filtered 23Na NMR spectroscopy.

    Science.gov (United States)

    Gobet, Mallory; Rondeau-Mouro, Corinne; Buchin, Solange; Le Quéré, Jean-Luc; Guichard, Elisabeth; Foucat, Loïc; Moreau, Céline

    2010-04-01

    The feasibility of solid-state magic angle spinning (MAS) (31)P nuclear magnetic resonance (NMR) spectroscopy and (23)Na NMR spectroscopy to investigate both phosphates and Na(+) ions distribution in semi-hard cheeses in a non-destructive way was studied. Two semi-hard cheeses of known composition were made with two different salt contents. (31)P Single-pulse excitation and cross-polarization MAS experiments allowed, for the first time, the identification and quantification of soluble and insoluble phosphates in the cheeses. The presence of a relatively 'mobile' fraction of colloidal phosphates was evidenced. The detection by (23)Na single-quantum NMR experiments of all the sodium ions in the cheeses was validated. The presence of a fraction of 'bound' sodium ions was evidenced by (23)Na double-quantum filtered NMR experiments. We demonstrated that NMR is a suitable tool to investigate both phosphates and Na(+) ions distributions in cheeses. The impact of the sodium content on the various phosphorus forms distribution was discussed and results demonstrated that NMR would be an important tool for the cheese industry for the processes controls.

  12. Exercise-induced 31P-NMR metabolic response of human wrist flexor muscles during partial neuromuscular blockade.

    Science.gov (United States)

    Mizuno, M; Horn, A; Secher, N H; Quistorff, B

    1994-08-01

    The effects of a depolarizing (decamethonium, DECA) and a nondepolarizing neuromuscular blocking agent (vecuronium, VECU) on the phosphorus-31 nuclear magnetic resonance (31P-NMR)-detected metabolic response to muscle contractions were studied separately in six healthy untrained males. Subjects who showed splitting of the P(i) peak during graded rhythmic forearm exercise without the drugs were selected. It was found that both drugs abolished the P(i) peak splitting during exercise. Despite a similar reduction in phosphocreatine (PCr) during exercise with each drug, a smaller increase in P(i) was observed with DECA than with VECU (P VECU (6.79 +/- 0.11) (P VECU, respectively (P < 0.05). On the basis of the concept that depolarizing and nondepolarizing agents have a preferential effect on fast- and slow-twitch muscle fibers, respectively, the present results support the hypothesis that the NMR-observed splitting of the P(i) peak reflects the metabolic differences between the two major fiber types of human skeletal muscle.

  13. Nuclear Magnetic Resonance Imaging of Li-ion Battery

    Directory of Open Access Journals (Sweden)

    D. Ohno

    2010-12-01

    Full Text Available Nuclear magnetic resonance (NMR imaging has high sensitivity to proton (1H and lithium (7Li. It is a useful measurement for electrolyte in Li-ion battery. 1H NMR images of lithium ion battery which is composed of LiMn2O4 / LiClO4 + propylene carbonate (PC / Li-metal have been studied. 1H NMR images of electrolyte near cathode material (LiMn2O4 showed anomalous intensity distribution, which was quite inhomogeneous. From NMR images as a function of repetition time (TR, it was concluded that the anomalous intensity distribution was not due to change of relaxation time but an indirect (spatial para-magnetization effect from cathode material. The paramagnetization induced by high magnetic field distorts linearity of magnetic gradient field, leading to apparent intensity variance. This functional image is an easy diagnostic measurement for magnetization of cathode material, which allows the possibility to check uniformity of cathode material and change of magnetization under electrochemical process.

  14. Quantitative velocity distributions via nuclear magnetic resonance flow metering

    Science.gov (United States)

    O'Neill, Keelan T.; Fridjonsson, Einar O.; Stanwix, Paul L.; Johns, Michael L.

    2016-08-01

    We demonstrate the use of Tikhonov regularisation as a data inversion technique to determine the velocity distributions of flowing liquid streams. Regularisation is applied to the signal produced by a nuclear magnetic resonance (NMR) flow measurement system consisting of a pre-polarising permanent magnet located upstream of an Earth's magnetic field NMR detection coil. A simple free induction decay (FID) NMR signal is measured for the flowing stream in what is effectively a 'time-of-flight' measurement. The FID signal is then modelled as a function of fluid velocity and acquisition time, enabling determination of the velocity probability distributions via regularisation. The mean values of these velocity distributions were successfully validated against in-line rotameters. The ability to quantify multi-modal velocity distributions was also demonstrated using a two-pipe system.

  15. Parahydrogen enhanced zero-field nuclear magnetic resonance

    CERN Document Server

    Theis, Thomas; Kervern, Gwendal; Knappe, Svenja; Kitching, John; Ledbetter, Micah; Budker, Dmitry; Pines, Alex

    2011-01-01

    Nuclear magnetic resonance (NMR), conventionally detected in multi-tesla magnetic fields, is a powerful analytical tool for the determination of molecular identity, structure, and function. With the advent of prepolarization methods and alternative detection schemes using atomic magnetometers or superconducting quantum interference devices (SQUIDs), NMR in very low- (~earth's field), and even zero-field, has recently attracted considerable attention. Despite the use of SQUIDs or atomic magnetometers, low-field NMR typically suffers from low sensitivity compared to conventional high-field NMR. Here we demonstrate direct detection of zero-field NMR signals generated via parahydrogen induced polarization (PHIP), enabling high-resolution NMR without the use of any magnets. The sensitivity is sufficient to observe spectra exhibiting 13C-1H J-couplings in compounds with 13C in natural abundance in a single transient. The resulting spectra display distinct features that have straightforward interpretation and can be...

  16. DC superconducting quantum interference device usable in nuclear quadrupole resonance and zero field nuclear magnetic spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Non Q. (San Diego, CA); Clarke, John (Berkeley, CA)

    1993-01-01

    A spectrometer for measuring the nuclear quadrupole resonance spectra or the zero-field nuclear magnetic resonance spectra generated by a sample is disclosed. The spectrometer uses an amplifier having a dc SQUID operating in a flux-locked loop for generating an amplified output as a function of the intensity of the signal generated by the sample. The flux-locked loop circuit includes an integrator. The amplifier also includes means for preventing the integrator from being driven into saturation. As a result, the time for the flux-locked loop to recover from the excitation pulses generated by the spectrometer is reduced.

  17. DC superconducting quantum interference device usable in nuclear quadrupole resonance and zero field nuclear magnetic spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Fan, N.Q.; Clarke, J.

    1993-10-19

    A spectrometer for measuring the nuclear quadrupole resonance spectra or the zero-field nuclear magnetic resonance spectra generated by a sample is disclosed. The spectrometer uses an amplifier having a dc SQUID operating in a flux-locked loop for generating an amplified output as a function of the intensity of the signal generated by the sample. The flux-locked loop circuit includes an integrator. The amplifier also includes means for preventing the integrator from being driven into saturation. As a result, the time for the flux-locked loop to recover from the excitation pulses generated by the spectrometer is reduced. 7 figures.

  18. Measurement of untruncated nuclear spin interactions via zero- to ultralow-field nuclear magnetic resonance

    Science.gov (United States)

    Blanchard, J. W.; Sjolander, T. F.; King, J. P.; Ledbetter, M. P.; Levine, E. H.; Bajaj, V. S.; Budker, D.; Pines, A.

    2015-12-01

    Zero- to ultralow-field nuclear magnetic resonance (ZULF NMR) provides a new regime for the measurement of nuclear spin-spin interactions free from the effects of large magnetic fields, such as truncation of terms that do not commute with the Zeeman Hamiltonian. One such interaction, the magnetic dipole-dipole coupling, is a valuable source of spatial information in NMR, though many terms are unobservable in high-field NMR, and the coupling averages to zero under isotropic molecular tumbling. Under partial alignment, this information is retained in the form of so-called residual dipolar couplings. We report zero- to ultralow-field NMR measurements of residual dipolar couplings in acetonitrile-2-13C aligned in stretched polyvinyl acetate gels. This permits the investigation of dipolar couplings as a perturbation on the indirect spin-spin J coupling in the absence of an applied magnetic field. As a consequence of working at zero magnetic field, we observe terms of the dipole-dipole coupling Hamiltonian that are invisible in conventional high-field NMR. This technique expands the capabilities of zero- to ultralow-field NMR and has potential applications in precision measurement of subtle physical interactions, chemical analysis, and characterization of local mesoscale structure in materials.

  19. Decoherence and fluctuation dynamics of the quantum dot nuclear spin bath probed by nuclear magnetic resonance

    Science.gov (United States)

    Chekhovich, Evgeny A.

    2017-06-01

    Dynamics of nuclear spin decoherence and nuclear spin flip-flops in self-assembled InGaAs/GaAs quantum dots are studied experimentally using optically detected nuclear magnetic resonance (NMR). Nuclear spin-echo decay times are found to be in the range 1-4 ms. This is a factor of ~3 longer than in strain-free GaAs/AlGaAs structures and is shown to result from strain-induced quadrupolar effects that suppress nuclear spin flip-flops. The correlation times of the flip-flops are examined using a novel frequency-comb NMR technique and are found to exceed 1 s, a factor of ~1000 longer than in strain-free structures. These findings complement recent studies of electron spin coherence and reveal the paradoxical dual role of the quadrupolar effects in self-assembled quantum dots: large increase of the nuclear spin bath coherence and at the same time significant reduction of the electron spin-qubit coherence. Approaches to increasing electron spin coherence are discussed. In particular the nanohole filled GaAs/AlGaAs quantum dots are an attractive option: while their optical quality matches the self-assembled dots the quadrupolar effects measured in NMR spectra are a factor of 1000 smaller.

  20. Characterization via nuclear magnetic resonance of Portland cement and related materials

    Science.gov (United States)

    Edwards, Christopher Lane

    The physicochemical and engineering performance properties of several API class G and H ordinary Portland cements (OPCs) from various foreign and domestic sources have been investigated. The engineering performance properties are found to vary from sample to sample, and sources for this variation were sought out and identified. Magic angle spinning (MAS) 29Si nuclear magnetic resonance (NMR) experiments were marked by unusual relaxation behavior due to paramagnetism inherent in OPCs. A model system was created to mimic the paramagnetism of the cements and the system's relaxation behavior was analyzed. The iron in the calcium aluminoferrite (C4AF) provides the paramagnetism sufficient to substantially increase the relaxation rates of the 29Si in the tricalcium silicate (C3S) and dicalcium silicate (C2S) of cement. Several relaxation techniques were evaluated for analyzing cement relaxation, and saturation recovery was identified as the preferred technique. Correlations of data from the saturation recovery experiments with engineering performance properties, especially the strength development of cement pastes, were obtained facilely. An error analysis of the NMR and engineering performance testing techniques was conducted, which indicated that NMR measurements produced less error than the engineering performance tests. A best practice, modified from the saturation recovery experiment, is proposed for use in property correlations. Additionally, 13C MAS NMR was used to characterize various fluorinated single-walled carbon nanotubes (F-SWNTs), which proved surprisingly effective in attenuating 13C-19F dipolar interactions and quantifying the extent of functionalization present at high degrees of reaction. The mixed-metal nanocluster known as FeMoC was also characterized by MAS NMR. The impact of the paramagnetic Fe3+ in the Keplerate cage on the 31P nuclei in the caged Keggin ion of FeMoC was evident in the greatly reduced relaxation times measured.

  1. Highly sensitive detection of protein biomarkers via nuclear magnetic resonance biosensor with magnetically engineered nanoferrite particles.

    Science.gov (United States)

    Jeun, Minhong; Park, Sungwook; Lee, Hakho; Lee, Kwan Hyi

    Magnetic-based biosensors are attractive for on-site detection of biomarkers due to the low magnetic susceptibility of biological samples. Here, we report a highly sensitive magnetic-based biosensing system that is composed of a miniaturized nuclear magnetic resonance (NMR) device and magnetically engineered nanoferrite particles (NFPs). The sensing performance, also identified as the transverse relaxation (R2) rate, of the NMR device is directly related to the magnetic properties of the NFPs. Therefore, we developed magnetically engineered NFPs (MnMg-NFP) and used them as NMR agents to exhibit a significantly improved R2 rate. The magnetization of the MnMg-NFPs was increased by controlling the Mn and Mg cation concentration and distribution during the synthesis process. This modification of the Mn and Mg cation directly contributed to improving the R2 rate. The miniaturized NMR system, combined with the magnetically engineered MnMg-NFPs, successfully detected a small amount of infectious influenza A H1N1 nucleoprotein with high sensitivity and stability.

  2. Light nuclear charge measurement with Alpha Magnetic Spectrometer Electromagnetic Calorimeter

    Energy Technology Data Exchange (ETDEWEB)

    Basara, Laurent [Trento Institute for Fundamental Physics and Applications, Povo 38123 (Italy); Choutko, Vitaly [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Li, Qiang, E-mail: q.li@cern.ch [Harbin Institute of Technology, Harbin, 150001 (China)

    2016-06-11

    The Alpha Magnetic Spectrometer (AMS) is a high energy particle detector installed and operating on board of the International Space Station (ISS) since May 2011. So far more than 70 billion cosmic ray events have been recorded by AMS. In the present paper the Electromagnetic Calorimeter (ECAL) detector of AMS is used to measure cosmic ray nuclear charge magnitudes up to Z=10. The obtained charge magnitude resolution is about 0.1 and 0.3 charge unit for Helium and Carbon, respectively. These measurements are important for an accurate determination of the interaction probabilities of various nuclei with the AMS materials. The ECAL charge calibration and measurement procedures are presented.

  3. Thermo-magnetic systems for space nuclear reactors an introduction

    CERN Document Server

    Maidana, Carlos O

    2014-01-01

    Introduces the reader to engineering magnetohydrodynamics applications and presents a comprehensive guide of how to approach different problems found in this multidisciplinary field. An introduction to engineering magnetohydrodynamics, this brief focuses heavily on the design of thermo-magnetic systems for liquid metals, with emphasis on the design of electromagnetic annular linear induction pumps for space nuclear reactors. Alloy systems that are liquid at room temperature have a high degree of thermal conductivity far superior to ordinary non-metallic liquids. This results in their use for

  4. Resonantly detecting axion-mediated forces with nuclear magnetic resonance.

    Science.gov (United States)

    Arvanitaki, Asimina; Geraci, Andrew A

    2014-10-17

    We describe a method based on precision magnetometry that can extend the search for axion-mediated spin-dependent forces by several orders of magnitude. By combining techniques used in nuclear magnetic resonance and short-distance tests of gravity, our approach can substantially improve upon current experimental limits set by astrophysics, and probe deep into the theoretically interesting regime for the Peccei-Quinn (PQ) axion. Our method is sensitive to PQ axion decay constants between 10(9) and 10(12) GeV or axion masses between 10(-6) and 10(-3) eV, independent of the cosmic axion abundance.

  5. Applications of nuclear magnetic resonance sensors to cultural heritage.

    Science.gov (United States)

    Proietti, Noemi; Capitani, Donatella; Di Tullio, Valeria

    2014-04-21

    In recent years nuclear magnetic resonance (NMR) sensors have been increasingly applied to investigate, characterize and monitor objects of cultural heritage interest. NMR is not confined to a few specific applications, but rather its use can be successfully extended to a wide number of different cultural heritage issues. A breakthrough has surely been the recent development of portable NMR sensors which can be applied in situ for non-destructive and non-invasive investigations. In this paper three studies illustrating the potential of NMR sensors in this field of research are reported.

  6. Implementation of Quantum Private Queries Using Nuclear Magnetic Resonance

    Institute of Scientific and Technical Information of China (English)

    WANG Chuan; HAO Liang; ZHAO Lian-Jie

    2011-01-01

    @@ We present a modified protocol for the realization of a quantum private query process on a classical database.Using one-qubit query and CNOT operation,the query process can be realized in a two-mode database.In the query process,the data privacy is preserved as the sender would not reveal any information about the database besides her query information,and the database provider cannot retain any information about the query.We implement the quantum private query protocol in a nuclear magnetic resonance system.The density matrix of the memory registers are constructed.

  7. Applications of Nuclear Magnetic Resonance Sensors to Cultural Heritage

    Directory of Open Access Journals (Sweden)

    Noemi Proietti

    2014-04-01

    Full Text Available In recent years nuclear magnetic resonance (NMR sensors have been increasingly applied to investigate, characterize and monitor objects of cultural heritage interest. NMR is not confined to a few specific applications, but rather its use can be successfully extended to a wide number of different cultural heritage issues. A breakthrough has surely been the recent development of portable NMR sensors which can be applied in situ for non-destructive and non-invasive investigations. In this paper three studies illustrating the potential of NMR sensors in this field of research are reported.

  8. Random matrix theory in biological nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Lacelle, S

    1984-01-01

    The statistical theory of energy levels or random matrix theory is presented in the context of the analysis of chemical shifts of nuclear magnetic resonance (NMR) spectra of large biological systems. Distribution functions for the spacing between nearest-neighbor energy levels are discussed for uncorrelated, correlated, and random superposition of correlated energy levels. Application of this approach to the NMR spectra of a vitamin, an antibiotic, and a protein demonstrates the state of correlation of an ensemble of energy levels that characterizes each system. The detection of coherent and dissipative structures in proteins becomes feasible with this statistical spectroscopic technique. PMID:6478032

  9. 11B nuclear magnetic resonance in boron-doped diamond

    Directory of Open Access Journals (Sweden)

    Miwa Murakami, Tadashi Shimizu, Masataka Tansho and Yoshihiko Takano

    2008-01-01

    Full Text Available This review summarizes recent results obtained by 11B solid-state nuclear magnetic resonance (NMR on boron-doped diamond, grown by the high-pressure high-temperature (HPHT or chemical vapor deposition techniques. Simple single-pulse experiments as well as advanced two-dimensional NMR experiments were applied to the boron sites in diamond. It is shown that magic-angle spinning at magnetic fields above 10 T is suitable for observation of high-resolution 11B spectra of boron-doped diamond. For boron-doped HPHT diamonds, the existence of the excess boron that does not contribute to electrical conductivity was confirmed and its 11B NMR signal was characterized. The point-defect structures (B+H complexes and -B-B-/-B-C-B- clusters, postulated previously for the excess boron, were discarded and graphite-like structures were assigned instead.

  10. Development of Metallic Magnetic Calorimeters for Nuclear Safeguards Applications

    Energy Technology Data Exchange (ETDEWEB)

    Bates, Cameron Russell [Univ. of California, Berkeley, CA (United States)

    2015-03-11

    Many nuclear safeguards applications could benefit from high-resolution gamma-ray spectroscopy achievable with metallic magnetic calorimeters. This dissertation covers the development of a system for these applications based on gamma-ray detectors developed at the University of Heidelberg. It demonstrates new calorimeters of this type, which achieved an energy resolution of 45.5 eV full-width at half-maximum at 59.54 keV, roughly ten times better than current state of the art high purity germanium detectors. This is the best energy resolution achieved with a gamma-ray metallic magnetic calorimeter at this energy to date. In addition to demonstrating a new benchmark in energy resolution, an experimental system for measuring samples with metallic magnetic calorimeters was constructed at Lawrence Livermore National Laboratory. This system achieved an energy resolution of 91.3 eV full-width at half-maximum at 59.54 keV under optimal conditions. Using this system it was possible to characterize the linearity of the response, the count-rate limitations, and the energy resolution as a function of temperature of the new calorimeter. With this characterization it was determined that it would be feasible to measure 242Pu in a mixed isotope plutonium sample. A measurement of a mixed isotope plutonium sample was performed over the course of 12 days with a single two-pixel metallic magnetic calorimeter. The relative concentration of 242Pu in comparison to other plutonium isotopes was determined by direct measurement to less than half a percent accuracy. This is comparable with the accuracy of the best-case scenario using traditional indirect methods. The ability to directly measure the relative concentration of 242Pu in a sample could enable more accurate accounting and detection of indications of undeclared activities in nuclear safeguards, a better constraint on source material in forensic samples containing plutonium, and improvements in verification in a future plutonium

  11. Nuclear conversion theory: molecular hydrogen in non-magnetic insulators

    Science.gov (United States)

    Ilisca, Ernest; Ghiglieno, Filippo

    2016-09-01

    The hydrogen conversion patterns on non-magnetic solids sensitively depend upon the degree of singlet/triplet mixing in the intermediates of the catalytic reaction. Three main `symmetry-breaking' interactions are brought together. In a typical channel, the electron spin-orbit (SO) couplings introduce some magnetic excitations in the non-magnetic solid ground state. The electron spin is exchanged with a molecular one by the electric molecule-solid electron repulsion, mixing the bonding and antibonding states and affecting the molecule rotation. Finally, the magnetic hyperfine contact transfers the electron spin angular momentum to the nuclei. Two families of channels are considered and a simple criterion based on the SO coupling strength is proposed to select the most efficient one. The denoted `electronic' conversion path involves an emission of excitons that propagate and disintegrate in the bulk. In the other denoted `nuclear', the excited electron states are transients of a loop, and the electron system returns to its fundamental ground state. The described model enlarges previous studies by extending the electron basis to charge-transfer states and `continui' of band states, and focuses on the broadening of the antibonding molecular excited state by the solid conduction band that provides efficient tunnelling paths for the hydrogen conversion. After working out the general conversion algebra, the conversion rates of hydrogen on insulating and semiconductor solids are related to a few molecule-solid parameters (gap width, ionization and affinity potentials) and compared with experimental measures.

  12. Dynamics of asymmetric non-polymeric binary glass formers—A nuclear magnetic resonance and dielectric spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Pötzschner, B.; Mohamed, F.; Lichtinger, A.; Bock, D.; Rössler, E. A., E-mail: ernst.roessler@uni-bayreuth.de [Experimentalphysik II, Universität Bayreuth, 95440 Bayreuth (Germany)

    2015-10-21

    We study a dynamically asymmetric binary glass former with the low-T{sub g} component m-tri-cresyl phosphate (m-TCP: T{sub g} = 206 K) and a spirobichroman derivative as a non-polymeric high-T{sub g} component (T{sub g} = 382 K) by means of {sup 1}H nuclear magnetic resonance (NMR), {sup 31}P NMR, and dielectric spectroscopy which allow component-selectively probing the dynamics. The entire concentration range is covered, and two main relaxation processes with two T{sub g} are identified, T{sub g1} and T{sub g2}. The slower one is attributed to the high-T{sub g} component (α{sub 1}-process), and the faster one is related to the m-TCP molecules (α{sub 2}-process). Yet, there are indications that a small fraction of m-TCP is associated also with the α{sub 1}-process. While the α{sub 1}-relaxation only weakly broadens upon adding m-TCP, the α{sub 2}-relaxation becomes extremely stretched leading to quasi-logarithmic correlation functions at low m-TCP concentrations—as probed by {sup 31}P NMR stimulated echo experiments. Frequency-temperature superposition does not apply for the α{sub 2}-process and it reflects an isotropic, liquid-like motion which is observed even below T{sub g1}, i.e., in the matrix of the arrested high-T{sub g} molecules. As proven by 2D {sup 31}P NMR, the corresponding dynamic heterogeneities are of transient nature, i.e., exchange occurs within the distribution G(lnτ{sub α2}). At T{sub g1} a crossover is found for the temperature dependence of (mean) τ{sub α2}(T) from non-Arrhenius above to Arrhenius below T{sub g1} which is attributed to intrinsic confinement effects. This “fragile-to-strong” transition also leads to a re-decrease of T{sub g2}(c{sub m−TCP}) at low concentration c{sub m−TCP}, i.e., a maximum is observed in T{sub g2}(c{sub m−TCP}) while T{sub g1}(c{sub m−TCP}) displays the well-known plasticizer effect. Although only non-polymeric components are involved, we re-discover essentially all features previously

  13. Dynamics of asymmetric non-polymeric binary glass formers-A nuclear magnetic resonance and dielectric spectroscopy study.

    Science.gov (United States)

    Pötzschner, B; Mohamed, F; Lichtinger, A; Bock, D; Rössler, E A

    2015-10-21

    We study a dynamically asymmetric binary glass former with the low-Tg component m-tri-cresyl phosphate (m-TCP: Tg = 206 K) and a spirobichroman derivative as a non-polymeric high-Tg component (Tg = 382 K) by means of (1)H nuclear magnetic resonance (NMR), (31)P NMR, and dielectric spectroscopy which allow component-selectively probing the dynamics. The entire concentration range is covered, and two main relaxation processes with two Tg are identified, Tg 1 and Tg 2. The slower one is attributed to the high-Tg component (α1-process), and the faster one is related to the m-TCP molecules (α2-process). Yet, there are indications that a small fraction of m-TCP is associated also with the α1-process. While the α1-relaxation only weakly broadens upon adding m-TCP, the α2-relaxation becomes extremely stretched leading to quasi-logarithmic correlation functions at low m-TCP concentrations-as probed by (31)P NMR stimulated echo experiments. Frequency-temperature superposition does not apply for the α2-process and it reflects an isotropic, liquid-like motion which is observed even below Tg 1, i.e., in the matrix of the arrested high-Tg molecules. As proven by 2D (31)P NMR, the corresponding dynamic heterogeneities are of transient nature, i.e., exchange occurs within the distribution G(lnτα 2). At Tg 1 a crossover is found for the temperature dependence of (mean) τα 2(T) from non-Arrhenius above to Arrhenius below Tg 1 which is attributed to intrinsic confinement effects. This "fragile-to-strong" transition also leads to a re-decrease of Tg 2(cm - TCP) at low concentration cm - TCP, i.e., a maximum is observed in Tg 2(cm - TCP) while Tg 1(cm - TCP) displays the well-known plasticizer effect. Although only non-polymeric components are involved, we re-discover essentially all features previously reported for polymer-plasticizer systems.

  14. Dynamics of asymmetric non-polymeric binary glass formers—A nuclear magnetic resonance and dielectric spectroscopy study

    Science.gov (United States)

    Pötzschner, B.; Mohamed, F.; Lichtinger, A.; Bock, D.; Rössler, E. A.

    2015-10-01

    We study a dynamically asymmetric binary glass former with the low-Tg component m-tri-cresyl phosphate (m-TCP: Tg = 206 K) and a spirobichroman derivative as a non-polymeric high-Tg component (Tg = 382 K) by means of 1H nuclear magnetic resonance (NMR), 31P NMR, and dielectric spectroscopy which allow component-selectively probing the dynamics. The entire concentration range is covered, and two main relaxation processes with two Tg are identified, Tg1 and Tg2. The slower one is attributed to the high-Tg component (α1-process), and the faster one is related to the m-TCP molecules (α2-process). Yet, there are indications that a small fraction of m-TCP is associated also with the α1-process. While the α1-relaxation only weakly broadens upon adding m-TCP, the α2-relaxation becomes extremely stretched leading to quasi-logarithmic correlation functions at low m-TCP concentrations—as probed by 31P NMR stimulated echo experiments. Frequency-temperature superposition does not apply for the α2-process and it reflects an isotropic, liquid-like motion which is observed even below Tg1, i.e., in the matrix of the arrested high-Tg molecules. As proven by 2D 31P NMR, the corresponding dynamic heterogeneities are of transient nature, i.e., exchange occurs within the distribution G(lnτα2). At Tg1 a crossover is found for the temperature dependence of (mean) τα2(T) from non-Arrhenius above to Arrhenius below Tg1 which is attributed to intrinsic confinement effects. This "fragile-to-strong" transition also leads to a re-decrease of Tg2(cm-TCP) at low concentration cm-TCP, i.e., a maximum is observed in Tg2(cm-TCP) while Tg1(cm-TCP) displays the well-known plasticizer effect. Although only non-polymeric components are involved, we re-discover essentially all features previously reported for polymer-plasticizer systems.

  15. Measuring the Muon g-2 Magnetic Storage Field Via Proton Nuclear Magnetic Resonance

    Science.gov (United States)

    Smith, Matthias; Muon g-2 Collaboration Collaboration

    2016-03-01

    The Muon g - 2 experiment at Fermilab aims to measure the muon anomalous magnetic moment, aμ, to a precision of 140 ppb, using a technique that determines the muon spin precession frequency in the highly uniform magnetic field of a storage ring. Both precession frequency and field determination contribute equally to the final systematic uncertainty. The magnetic field is determined from the measurement of free induction decay (FID) signals provided by a matrix of custom proton nuclear magnetic resonance (pNMR) probes. FID simulations show that we can achieve the required precision for extraction of field values compared to systematic contributions. The recently powered muon storage ring is providing data to evaluate the pNMR measurement results. We will describe the performance to date of this system.

  16. COMPARATIVE ASSESSMENT OF NUCLEAR MAGNETIC RELAXATION CHARACTERISTICS OF SUNFLOWER AND RAPESEED LECITHIN

    OpenAIRE

    Lisovaya E. V.; Victorova E. P.; Agafonov O. S.; Kornen N. N.; Shahray T. A.

    2015-01-01

    The article presents a comparative assessment and peculiarities of nuclear magnetic relaxation characteristics of rapeseed and sunflower lecithin. It was established, that lecithin’s nuclear magnetic relaxation characteristics, namely, protons’ spin-spin relaxation time and amplitudes of nuclear magnetic relaxation signals of lecithin components, depend on content of oil’s fat acids and phospholipids, contained in the lecithin. Comparative assessment of protons’ spin-spin relaxation time of r...

  17. Investigation of the curvature induction and membrane localization of the influenza virus M2 protein using static and off-magic-angle spinning solid-state nuclear magnetic resonance of oriented bicelles.

    Science.gov (United States)

    Wang, Tuo; Hong, Mei

    2015-04-07

    A wide variety of membrane proteins induce membrane curvature for function; thus, it is important to develop new methods to simultaneously determine membrane curvature and protein binding sites in membranes with multiple curvatures. We introduce solid-state nuclear magnetic resonance (NMR) methods based on magnetically oriented bicelles and off-magic-angle spinning (OMAS) to measure membrane curvature and the binding site of proteins in mixed-curvature membranes. We demonstrate these methods on the influenza virus M2 protein, which not only acts as a proton channel but also mediates virus assembly and membrane scission. An M2 peptide encompassing the transmembrane (TM) domain and an amphipathic helix, M2(21-61), was studied and compared with the TM peptide (M2TM). Static (31)P NMR spectra of magnetically oriented 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)/1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) bicelles exhibit a temperature-independent isotropic chemical shift in the presence of M2(21-61) but not M2TM, indicating that the amphipathic helix confers the ability to generate a high-curvature phase. Two-dimensional (2D) (31)P spectra indicate that this high-curvature phase is associated with the DHPC bicelle edges, suggestive of the structure of budding viruses from the host cell. (31)P- and (13)C-detected (1)H relaxation times of the lipids indicate that the majority of M2(21-61) is bound to the high-curvature phase. Using OMAS experiments, we resolved the (31)P signals of lipids with identical headgroups based on their distinct chemical shift anisotropies. On the basis of this resolution, 2D (1)H-(31)P correlation spectra show that the amide protons in M2(21-61) correlate with the DMPC but not DHPC (31)P signal of the bicelle, indicating that a small percentage of M2(21-61) partitions into the planar region of the bicelles. These results show that the amphipathic helix induces high membrane curvature and localizes the protein to this phase, in good

  18. Detection of molecules and cells using nuclear magnetic resonance with magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Rümenapp, Christine, E-mail: ruemenapp@tum.de [Zentralinstitut für Medizintechnik (IMETUM), Technische Universität München, Garching (Germany); Gleich, Bernhard [Zentralinstitut für Medizintechnik (IMETUM), Technische Universität München, Garching (Germany); Mannherz, Hans Georg [Abteilung für Anatomie und Molekulare Embryologie, Ruhr Universität Bochum, Bochum (Germany); Haase, Axel [Zentralinstitut für Medizintechnik (IMETUM), Technische Universität München, Garching (Germany)

    2015-04-15

    For the detection of small molecules, proteins or even cells in vitro, functionalised magnetic nanoparticles and nuclear magnetic resonance measurements can be applied. In this work, magnetic nanoparticles with the size of 5–7 nm were functionalised with antibodies to detect two model systems of different sizes, the protein avidin and Saccharomyces cerevisiae as the model organism. The synthesised magnetic nanoparticles showed a narrow size distribution, which was determined using transmission electron microscopy and dynamic light scattering. The magnetic nanoparticles were functionalised with the according antibodies via EDC/NHS chemistry. The binding of the antigen to magnetic nanoparticles was detected through the change in the NMR T{sub 2} relaxation time at 0.5 T (≈21.7 MHz). In case of a specific binding the particles cluster and the T{sub 2} relaxation time of the sample changes. The detection limit in buffer for FITC-avidin was determined to be 1.35 nM and 10{sup 7} cells/ml for S. cerevisiae. For fluorescent microscopy the avidin molecules were labelled with FITC and for the detection of S. cerevisiae the magnetic nanoparticles were additionally functionalised with rhodamine. The binding of the particles to S. cerevisiae and the resulting clustering was also seen by transmission electron microscopy.

  19. Analysis of ringing effects due to magnetic core materials in pulsed nuclear magnetic resonance circuits

    Energy Technology Data Exchange (ETDEWEB)

    Prabhu Gaunkar, N., E-mail: neelampg@iastate.edu; Bouda, N. R. Y.; Nlebedim, I. C.; Hadimani, R. L.; Mina, M.; Jiles, D. C. [Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011 (United States); Bulu, I.; Ganesan, K.; Song, Y. Q. [Schlumberger-Doll Research, Cambridge, Massachusetts 02139 (United States)

    2015-05-07

    This work presents investigations and detailed analysis of ringing in a non-resonant pulsed nuclear magnetic resonance (NMR) circuit. Ringing is a commonly observed phenomenon in high power switching circuits. The oscillations described as ringing impede measurements in pulsed NMR systems. It is therefore desirable that those oscillations decay fast. It is often assumed that one of the causes behind ringing is the role of the magnetic core used in the antenna (acting as an inductive load). We will demonstrate that an LRC subcircuit is also set-up due to the inductive load and needs to be considered due to its parasitic effects. It is observed that the parasitics associated with the inductive load become important at certain frequencies. The output response can be related to the response of an under-damped circuit and to the magnetic core material. This research work demonstrates and discusses ways of controlling ringing by considering interrelationships between different contributing factors.

  20. Nuclear magnetic resonance spectral analysis and molecular properties of berberine

    Science.gov (United States)

    Huang, Ming-Ju; Lee, Ken S.; Hurley, Sharon J.

    An extensive theoretical study of berberine has been performed at the ab initio HF/6-31G**, HF/6-311G**, and B3LYP/6-311G** levels with and without solvent effects. The optimized structures are compared with X-ray data. We found that the optimized structures with solvent effects are in slightly better agreement with X-ray data than those without solvent effects. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of berberine were calculated by using the gauge-independent atomic orbital (GIAO) (with and without solvent effects), CSGT, and IGAIM methods. The calculated chemical shifts were compared with the two-dimensional NMR experimental data. Overall, the calculated chemical shifts show very good agreement with the experimental results. The harmonic vibrational frequencies for berberine were calculated at the B3LYP/6-311G** level.

  1. Multinuclear solid-state nuclear magnetic resonance of inorganic materials

    CERN Document Server

    MacKenzie, Kenneth J D

    2002-01-01

    Techniques of solid state nuclear magnetic resonance (NMR) spectroscopy are constantly being extended to a more diverse range of materials, pressing into service an ever-expanding range of nuclides including some previously considered too intractable to provide usable results. At the same time, new developments in both hardware and software are being introduced and refined. This book covers the most important of these new developments. With sections addressed to non-specialist researchers (providing accessible answers to the most common questions about the theory and practice of NMR asked by novices) as well as a more specialised and up-to-date treatment of the most important areas of inorganic materials research to which NMR has application, this book should be useful to NMR users whatever their level of expertise and whatever inorganic materials they wish to study.

  2. Applications of nuclear magnetic resonance imaging in process engineering

    Science.gov (United States)

    Gladden, Lynn F.; Alexander, Paul

    1996-03-01

    During the past decade, the application of nuclear magnetic resonance (NMR) imaging techniques to problems of relevance to the process industries has been identified. The particular strengths of NMR techniques are their ability to distinguish between different chemical species and to yield information simultaneously on the structure, concentration distribution and flow processes occurring within a given process unit. In this paper, examples of specific applications in the areas of materials and food processing, transport in reactors and two-phase flow are discussed. One specific study, that of the internal structure of a packed column, is considered in detail. This example is reported to illustrate the extent of new, quantitative information of generic importance to many processing operations that can be obtained using NMR imaging in combination with image analysis.

  3. Nuclear Magnetic Resonance Study of Nanoscale Ionic Materials

    KAUST Repository

    Oommen, Joanna Mary

    2010-08-13

    Nanoscale ionic materials (NIMs) are a new class of nanomaterials that exhibit interesting properties including negligible vapor pressures and tunable physical states, among others. In this study, we analyzed the temperature-wise performance of NIMs using nuclear magnetic resonance (NMR) spectroscopy. NIMs are relatively stable over a temperature range from 300 to 383 K, rendering them usable in high temperature applications. We confirmed the presence of covalent bonds between the SiO2 core and the sulfonate group and determined relative concentrations of aromatic and aliphatic hydrocarbons. These findings serve as first hand proof-of-concept for the usefulness of NMR analyses in further studies on the diffusive properties of NIMs. © 2010 The Electrochemical Society.

  4. In vivo nuclear magnetic resonance metabolite profiling in plant seeds.

    Science.gov (United States)

    Terskikh, Victor; Kermode, Allison R

    2011-01-01

    Nuclear magnetic resonance (NMR) spectroscopy has been successfully applied to profile a variety of primary and secondary metabolites in whole intact plant seeds in vivo. The nondestructive nature of NMR spectroscopy allows direct metabolic studies to be performed on the same seed throughout a given physio-logical process or key lifecycle transition, such as dormancy breakage, germination, and early postgerminative growth. Multinuclear NMR is capable of evaluating seed quality by assessing nondestructively nutrient reserves and seed protectants at seed maturity and to further monitor reserve mobilization following germination, which is critical for seedling emergence. In this chapter, we illustrate the use of several in vivo NMR techniques for metabolite profiling in seeds. Importantly, some of these methods have potential for the screening of single seeds or seed populations to identify seedlots with compromised viability either due to developmental problems or as a result of deterioration during prolonged storage.

  5. Nuclear magnetic resonance tomography of the cervical canal

    Energy Technology Data Exchange (ETDEWEB)

    Terwey, B.; Koschorek, F.; Jensen, H.P.

    1985-12-01

    170 patients with suspected lesions of the cervical part of the medulla were examined using nuclear magnetic resonance (NMR) tomography. 27 cases revealed no pathological changes in the regions of the cervical medulla, the cervical canal and of the cervical spine. 143 cases produced pathological findings whose diagnoses determined therapeutical approach. Verified pathological changes comprised anomalies of the cranio-cervical junction like basilar impression and Arnold-Chiari malformation, various types of cavity formation in the cervical medulla (syringomyelia, hydromyelia), demyelinization processes, intramedullary and extramedullary tumours, intervertebral disk degeneration processes, dislocation of intervertebral disks and spondylophytes with spinal stenoses. Sagittal sections in different functional positions allowed to demonstrate the biomechanical effects of extramedullary masses on the cervical medulla. However, proven tumours could not be differentiated successfully using histological methods. Nevertheless, NMR tomography will replace invasive methods like conventional cervical myelography and CT myelography in diagnostic clarification of diseases of the cervical medulla.

  6. Nuclear magnetic resonance spectroscopy of single subnanoliter ova

    CERN Document Server

    Grisi, Marco; Guidetti, Roberto; Harris, Nicola; Boero, Giovanni

    2015-01-01

    Nuclear magnetic resonance (NMR) spectroscopy is, in principle, a promising candidate to study the intracellular chemistry of single microscopic living entities. However, due to sensitivity limitations, NMR experiments were reported only on very few and relatively large single cells down to a minimum volume of 10 nl. Here we show NMR spectroscopy of single ova at volume scales (0.1 and 0.5 nl) where life development begins for a broad variety of animals, humans included. We demonstrate that the sensitivity achieved by miniaturized inductive NMR probes (few pmol of 1H nuclei in some hours at 7 T) is sufficient to observe chemical heterogeneities among subnanoliter ova of tardigrades. Such sensitivities should allow to non-invasively monitor variations of concentrated intracellular compounds, such as glutathione, in single mammalian zygotes.

  7. Diffusion Pore Imaging by Hyperpolarized Xenon-129 Nuclear Magnetic Resonance

    CERN Document Server

    Kuder, Tristan Anselm; Windschuh, Johannes; Laun, Frederik Bernd

    2012-01-01

    Nuclear magnetic resonance (NMR) diffusion measurements are widely used to derive parameters indirectly related to the microstructure of biological tissues and porous media. However, a direct imaging of cell or pore shapes and sizes would be of high interest. For a long time, determining pore shapes by NMR diffusion acquisitions seemed impossible, because the necessary phase information could not be preserved. Here we demonstrate experimentally using the measurement technique which we have recently proposed theoretically that the shape of arbitrary closed pores can be imaged by diffusion acquisitions, which yield the phase information. For this purpose, we use hyperpolarized xenon gas in well-defined geometries. The signal can be collected from the whole sample which mainly eliminates the problem of vanishing signal at increasing resolution of conventional NMR imaging. This could be used to non-invasively gain structural information inaccessible so far such as pore or cell shapes, cell density or axon integri...

  8. Effect of a strong magnetic field on the energy yield of nuclear reactions in dense nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Sekerzhitskii, V.S. [Pushkin Pedagogical Institute, Brest (Belarus)

    1995-01-01

    According to modern concepts, the electron-neutron-nuclear (Aen) phase of dense highly degenerate matter can be realized in the shells of neutron stars. This phase has relatively stable and absolutely stable states of thermodynamic equilibrium. Strong magnetic fields can exist in neutron stars. For this reason, analysis of their effect on the characteristics of the Aen phase is of great interest. It is specially important to study the influence of strong magnetic fields on the energy yield of nuclear reactions in dense nuclear matter because the transition to the absolute equilibrium state proceeds through these reactions.

  9. Single crystal nuclear magnetic resonance in spinning powders

    Science.gov (United States)

    Pell, Andrew J.; Pintacuda, Guido; Emsley, Lyndon

    2011-10-01

    We present a method for selectively exciting nuclear magnetic resonances (NMRs) from well-defined subsets of crystallites from a powdered sample under magic angle spinning. Magic angle spinning induces a time dependence in the anisotropic interactions, which results in a time variation of the resonance frequencies which is different for different crystallite orientations. The proposed method exploits this by applying selective pulses, which we refer to as XS (for crystallite-selective) pulses, that follow the resonance frequencies of nuclear species within particular crystallites, resulting in the induced flip angle being orientation dependent. By selecting the radiofrequency field to deliver a 180 ○ pulse for the target orientation and employing a train of such pulses combined with cogwheel phase cycling, we obtain a high degree of orientational selectivity with the resulting spectrum containing only contributions from orientations close to the target. Typically, this leads to the selection of between 0.1% and 10% of the crystallites, and in extreme cases to the excitation of a single orientation resulting in single crystal spectra of spinning powders. Two formulations of this method are described and demonstrated with experimental examples on [1 - 13C]-alanine and the paramagnetic compound Sm2Sn2O7.

  10. Low-frequency nuclear magnetic resonance and nuclear quadrupole resonance spectrometer based on a dc superconducting quantum interference device

    Science.gov (United States)

    Fan, N. Q.; Clarke, John

    1991-06-01

    A sensitive spectrometer, based on a dc superconducting quantum interference device, for the direct detection of low-frequency pulsed nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR), is described. The frequency response extends from about 10 to 200 kHz, and the recovery time after the magnetic pulse is removed is typically 50 μs. As examples, NMR spectra are shown from Pt and Cu metal powders in a magnetic field of 6 mT, and NQR spectra are shown from 2D in a tunneling methyl group and 14N in NH4ClO4.

  11. Nuclear magnetic shieldings of stacked aromatic and antiaromatic molecules.

    Science.gov (United States)

    Sundholm, Dage; Rauhalahti, Markus; Özcan, Nergiz; Mera-Adasme, Raul; Kussmann, Jörg; Luenser, Arne; Ochsenfeld, Christian

    2017-03-13

    Nuclear magnetic shieldings have been calculated at the density functional theory (DFT) level for stacks of benzene, hexadehydro[12]annulene, dodecadehydro[18]annulene and hexabenzocoronene. The magnetic shieldings due to the ring currents in the adjacent molecules have been estimated by calculating nucleus independent molecular shieldings for the monomer in the atomic positions of neighbor molecules. The calculations show that the independent shielding model works reasonable well for the (1)H NMR shieldings of benzene and hexadehydro[12]annulene, whereas for the larger molecules and for the (13)C NMR shieldings the interaction between the molecules leads to shielding effects that are at least of the same size as the ring current contributions from the adjacent molecules. A better agreement is obtained when the nearest neighbors are also considered at full quantum mechanical (QM) level. The calculations suggest that the nearest solvent molecules must be included in the quantum mechanical system, at least when estimating solvent shifts at the molecular mechanics (MM) level. Current density calculations show that the stacking does not significantly affect the ring current strengths of the individual molecules, whereas the shape of the ring current for a single molecule differs from that of the stacked molecules.

  12. Saturation properties of nuclear matter in the presence of strong magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Rezaei, Z. [Shiraz University, Department of Physics and Biruni Observatory, Shiraz (Iran, Islamic Republic of); Bordbar, G.H. [Shiraz University, Department of Physics and Biruni Observatory, Shiraz (Iran, Islamic Republic of); Center for Excellence in Astronomy and Astrophysics (CEAA-RIAAM)-Maragha, P.O. Box 55134-441, Maragha (Iran, Islamic Republic of)

    2016-05-15

    Different saturation properties of cold symmetric nuclear matter in strong magnetic field have been considered. We have seen that for magnetic fields about B>3 x 10{sup 17} G, for both cases with and without nucleon anomalous magnetic moments, the saturation density and saturation energy grow by increasing the magnetic field. It is indicated that the magnetic susceptibility of symmetric nuclear matter becomes negative showing the diamagnetic response especially at B<3 x 10{sup 17} G. We have found that for the nuclear matter, the magnitude of orbital magnetization reaches higher values comparing to the spin magnetization. Our results for the incompressibility show that at high enough magnetic fields, i.e. B>3 x 10{sup 17} G, the softening of the equation of state caused by Landau quantization is overwhelmed by stiffening due to the magnetization of nuclear matter. We have shown that the effects of strong magnetic field on nuclear matter may affect the constraints on the equation of state of symmetric nuclear matter obtained by applying the experimental observables. (orig.)

  13. Nuclear magnetic resonance in atomic-scale superconductor/magnet multilayered systems

    CERN Document Server

    Kanegae, Y

    2003-01-01

    We investigate the nuclear spin-lattice relaxation rate (T sub 1 T) sup - sup 1 in atomic-scale superconductor/magnet multilayered systems and discuss the discrepancy between two recent (T sub 1 T) sup - sup 1 experiments on Ru in RuSr sub 2 YCu sub 2 O sub 8. When the magnetic layers is are in the antiferromagnetic state, (T sub 1 T) sup - sup 1 in the magnetic layers is shown to decrease with decreasing due to the excitation gap associated with the magnetic ordering. The proximity effect of superconductivity on (T sub 1 T) sup - sup 1 in the magnetic layer is negligibly small. Our result indicates that the temperature dependence of (T sub 1 T) sup - sup 1 on Ru in RuSr sub 2 YCu sub 2 O sub 8 likely originates from the antiferromagnetism in the RuO sub 2 layers, but not from the superconductivity in the CuO sub 2 layers. (author)

  14. High temperature spin dynamics in linear magnetic chains, molecular rings, and segments by nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Adelnia, Fatemeh; Lascialfari, Alessandro [Dipartimento di Fisica, Università degli Studi di Milano and INSTM, Milano (Italy); Dipartimento di Fisica, Università degli Studi di Pavia and INSTM, Pavia (Italy); Mariani, Manuel [Dipartimento di Fisica e Astronomia, Università di Bologna, Bologna (Italy); Ammannato, Luca; Caneschi, Andrea; Rovai, Donella [Dipartimento di Chimica, Università degli Studi di Firenze and INSTM, Firenze (Italy); Winpenny, Richard; Timco, Grigore [School of Chemistry, The University of Manchester, Manchester (United Kingdom); Corti, Maurizio, E-mail: maurizio.corti@unipv.it; Borsa, Ferdinando [Dipartimento di Fisica, Università degli Studi di Pavia and INSTM, Pavia (Italy)

    2015-05-07

    We present the room temperature proton nuclear magnetic resonance (NMR) nuclear spin-lattice relaxation rate (NSLR) results in two 1D spin chains: the Heisenberg antiferromagnetic (AFM) Eu(hfac){sub 3}NITEt and the magnetically frustrated Gd(hfac){sub 3}NITEt. The NSLR as a function of external magnetic field can be interpreted very well in terms of high temperature spin dynamics dominated by a long time persistence of the decay of the two-spin correlation function due to the conservation of the total spin value for isotropic Heisenberg chains. The high temperature spin dynamics are also investigated in Heisenberg AFM molecular rings. In both Cr{sub 8} closed ring and in Cr{sub 7}Cd and Cr{sub 8}Zn open rings, i.e., model systems for a finite spin segment, an enhancement of the low frequency spectral density is found consistent with spin diffusion but the high cut-off frequency due to intermolecular anisotropic interactions prevents a detailed analysis of the spin diffusion regime.

  15. Rotatable Small Permanent Magnet Array for Ultra-Low Field Nuclear Magnetic Resonance Instrumentation: A Concept Study.

    Directory of Open Access Journals (Sweden)

    Michael W Vogel

    Full Text Available We studied the feasibility of generating the variable magnetic fields required for ultra-low field nuclear magnetic resonance relaxometry with dynamically adjustable permanent magnets. Our motivation was to substitute traditional electromagnets by distributed permanent magnets, increasing system portability.The finite element method (COMSOL® was employed for the numerical study of a small permanent magnet array to calculate achievable magnetic field strength, homogeneity, switching time and magnetic forces. A manually operated prototype was simulated and constructed to validate the numerical approach and to verify the generated magnetic field.A concentric small permanent magnet array can be used to generate strong sample pre-polarisation and variable measurement fields for ultra-low field relaxometry via simple prescribed magnet rotations. Using the array, it is possible to achieve a pre-polarisation field strength above 100 mT and variable measurement fields ranging from 20-50 μT with 200 ppm absolute field homogeneity within a field-of-view of 5 x 5 x 5 cubic centimetres.A dynamic small permanent magnet array can generate multiple highly homogeneous magnetic fields required in ultra-low field nuclear magnetic resonance (NMR and magnetic resonance imaging (MRI instruments. This design can significantly reduce the volume and energy requirements of traditional systems based on electromagnets, improving portability considerably.

  16. Nuclear forward scattering of synchrotron radiation in pulsed high magnetic fields.

    Science.gov (United States)

    Strohm, C; Van der Linden, P; Rüffer, R

    2010-02-26

    We report the demonstration of nuclear forward scattering of synchrotron radiation from 57Fe in ferromagnetic alpha iron in pulsed high magnetic fields up to 30 T. The observed magnetic hyperfine field follows the calculated high field bulk magnetization within 1%, establishing the technique as a precise tool for the study of magnetic solids in very high magnetic fields. To perform these experiments in pulsed fields, we have developed a detection scheme for fully time resolved nuclear forward scattering applicable to other pump probe experiments.

  17. Magnetic Moments of Octet Baryons in Hot and Dense Nuclear Matter

    CERN Document Server

    Singh, Harpreet; Dahiya, Harleen

    2016-01-01

    We have calculated the in-medium magnetic moments of octet baryons in the presence of hot and dense symmetric nuclear matter. Effective magnetic moments of baryons have been derived from medium modified quark masses within chiral SU(3) quark mean field model.Further, for better insight of medium modification of baryonic magnetic moments, we have considered the explicit contributions from the valence as well as sea quark effects. These effects have been successful in giving the description of baryonic magnetic moments in vacuum. The magnetic moments of baryons are found to vary significantly as a function of density of nuclear medium.

  18. Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods

    Energy Technology Data Exchange (ETDEWEB)

    Keating, Kristina [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Slater, Lee [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Ntarlagiannis, Dimitris [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Williams, Kenneth H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division

    2015-02-24

    This documents contains the final report for the project "Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods" (DE-SC0007049) Executive Summary: Our research aimed to develop borehole measurement techniques capable of monitoring subsurface processes, such as changes in pore geometry and iron/sulfur geochemistry, associated with remediation of heavy metals and radionuclides. Previous work has demonstrated that geophysical method spectral induced polarization (SIP) can be used to assess subsurface contaminant remediation; however, SIP signals can be generated from multiple sources limiting their interpretation value. Integrating multiple geophysical methods, such as nuclear magnetic resonance (NMR) and magnetic susceptibility (MS), with SIP, could reduce the ambiguity of interpretation that might result from a single method. Our research efforts entails combining measurements from these methods, each sensitive to different mineral forms and/or mineral-fluid interfaces, providing better constraints on changes in subsurface biogeochemical processes and pore geometries significantly improving our understanding of processes impacting contaminant remediation. The Rifle Integrated Field Research Challenge (IFRC) site was used as a test location for our measurements. The Rifle IFRC site is located at a former uranium ore-processing facility in Rifle, Colorado. Leachate from spent mill tailings has resulted in residual uranium contamination of both groundwater and sediments within the local aquifer. Studies at the site include an ongoing acetate amendment strategy, native microbial populations are stimulated by introduction of carbon intended to alter redox conditions and immobilize uranium. To test the geophysical methods in the field, NMR and MS logging measurements were collected before, during, and after acetate amendment. Next, laboratory NMR, MS, and SIP measurements

  19. Magnetism and Superconductivity in Iron-based Superconductors as Probed by Nuclear Magnetic Resonance

    CERN Document Server

    Hammerath, Franziska

    2012-01-01

    Nuclear Magnetic Resonance (NMR) has been a fundamental player in the studies of superconducting materials for many decades. This local probe technique allows for the study of the static electronic properties as well as of the low energy excitations of the electrons in the normal and the superconducting state. On that account it has also been widely applied to Fe-based superconductors from the very beginning of their discovery in February 2008. This dissertation comprises some of these very first NMR results, reflecting the unconventional nature of superconductivity and its strong link to magnetism in the investigated compounds LaO1–xFxFeAs and LiFeAs.

  20. Nuclear spin conversion of water inside fullerene cages detected by low-temperature nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Mamone, Salvatore, E-mail: s.mamone@soton.ac.uk; Concistrè, Maria; Carignani, Elisa; Meier, Benno; Krachmalnicoff, Andrea; Johannessen, Ole G.; Denning, Mark; Carravetta, Marina; Whitby, Richard J.; Levitt, Malcolm H., E-mail: mhl@soton.ac.uk [School of Chemistry, University of Southampton, Southampton SO17 1BJ (United Kingdom); Lei, Xuegong; Li, Yongjun [Department of Chemistry, Columbia University, New York, New York 10027 (United States); Goh, Kelvin; Horsewill, Anthony J. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom)

    2014-05-21

    The water-endofullerene H{sub 2}O@C{sub 60} provides a unique chemical system in which freely rotating water molecules are confined inside homogeneous and symmetrical carbon cages. The spin conversion between the ortho and para species of the endohedral H{sub 2}O was studied in the solid phase by low-temperature nuclear magnetic resonance. The experimental data are consistent with a second-order kinetics, indicating a bimolecular spin conversion process. Numerical simulations suggest the simultaneous presence of a spin diffusion process allowing neighbouring ortho and para molecules to exchange their angular momenta. Cross-polarization experiments found no evidence that the spin conversion of the endohedral H{sub 2}O molecules is catalysed by {sup 13}C nuclei present in the cages.

  1. Nuclear magnetic resonance experiments with dc SQUID amplifiers

    Energy Technology Data Exchange (ETDEWEB)

    Heaney, M.B. (California Univ., Berkeley, CA (USA). Dept. of Physics Lawrence Berkeley Lab., CA (USA))

    1990-11-01

    The development and fabrication of dc SQUIDs (Superconducting QUantum Interference Devices) with Nb/Al{sub 2}O{sub 3}/Nb Josephson junctions is described. A theory of the dc SQUID as a radio-frequency amplifier is presented, with an optimization strategy that accounts for the loading and noise contributions of the postamplifier and maximizes the signal-to-noise ratio of the total system. The high sensitivity of the dc SQUID is extended to high field NMR. A dc SQUID is used as a tuned radio-frequency amplifier to detect pulsed nuclear magnetic resonance at 32 MHz from a metal film in a 3.5 Tesla static field. A total system noise temperature of 11 K has been achieved, at a bath temperature of 4.2 K. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse is about 2 {times} 10{sup 17} in a bandwidth of 25 kHz. In a separate experiment, a dc SQUID is used as a rf amplifier in a NQR experiment to observe a new resonance response mechanism. The net electric polarization of a NaClO{sub 3} crystal due to the precessing electric quadrupole moments of the Cl nuclei is detected at 30 MHz. The sensitivity of NMR and NQR spectrometers using dc SQUID amplifiers is compared to the sensitivity of spectrometers using conventional rf amplifiers. A SQUID-based spectrometer has a voltage sensitivity which is comparable to the best achieved by a FET-based spectrometer, at these temperatures and operating frequencies.

  2. Novel nuclear magnetic resonance techniques for studying biological molecules

    Energy Technology Data Exchange (ETDEWEB)

    Laws, David D.

    2000-06-01

    Over the fifty-five year history of Nuclear Magnetic Resonance (NMR), considerable progress has been made in the development of techniques for studying the structure, function, and dynamics of biological molecules. The majority of this research has involved the development of multi-dimensional NMR experiments for studying molecules in solution, although in recent years a number of groups have begun to explore NMR methods for studying biological systems in the solid-state. Despite this new effort, a need still exists for the development of techniques that improve sensitivity, maximize information, and take advantage of all the NMR interactions available in biological molecules. In this dissertation, a variety of novel NMR techniques for studying biomolecules are discussed. A method for determining backbone ({phi}/{psi}) dihedral angles by comparing experimentally determined {sup 13}C{sub a}, chemical-shift anisotropies with theoretical calculations is presented, along with a brief description of the theory behind chemical-shift computation in proteins and peptides. The utility of the Spin-Polarization Induced Nuclear Overhauser Effect (SPINOE) to selectively enhance NMR signals in solution is examined in a variety of systems, as are methods for extracting structural information from cross-relaxation rates that can be measured in SPINOE experiments. Techniques for the production of supercritical and liquid laser-polarized xenon are discussed, as well as the prospects for using optically pumped xenon as a polarizing solvent. In addition, a detailed study of the structure of PrP 89-143 is presented. PrP 89-143 is a 54 residue fragment of the prion proteins which, upon mutation and aggregation, can induce prion diseases in transgenic mice. Whereas the structure of the wild-type PrP 89-143 is a generally unstructured mixture of {alpha}-helical and {beta}-sheet conformers in the solid state, the aggregates formed from the PrP 89-143 mutants appear to be mostly {beta}-sheet.

  3. Frequency and Spatial Selectivity in Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Friedrich, Jan O.

    1988-12-01

    Available from UMI in association with The British Library. Requires signed TDF. The techniques presented in this thesis are concerned with the high resolution nuclear magnetic resonance spectra of liquids. A selective pulse, shaped according to the first half of a Gaussian curve, is developed; it gives a very narrow absorption-mode excitation profile. This characteristics is used in developing selective coherence transfer experiments in which an individual transition is irradiated by the selective pulse followed by irradiation with an intense non-selective pulse. By stepping the irradiation frequency of the selective pulse along in small increments, this experiment produces results similar to conventional two-dimensional homonuclear correlation spectroscopy. Such a method allows selected spectral regions of a conventional two-dimensional spectrum to be examined under higher resolution while avoiding the restrictions imposed by the sampling theorem. The technique is also extended to a third frequency dimension by irradiating two transitions simultaneously before applying a non-selective pulse which yields correlations between three coupled nuclei. The remainder of this thesis introduces a spatial localisation method based on a "straddle coil": two parallel coaxial surface coils, one on each side of the sample and supplied with radiofrequency pulses of opposite phase. This configuration can be used for spatial localisation experiments by applying a sequence of equal and opposite prepulses before acquiring the signal. The prepulses saturate the nuclear spins in all sample regions except the sensitive volume close to the median plane where the radiofrequency fields from the two coils cancel. Pulse sequences are proposed that are insensitive to radiofrequency offset over an appreciable range. The location of the sensitive volume can be tracked across the sample in the axial dimension by changing the ratio of the radiofrequency currents in the two coils.

  4. Nuclear magnetic resonance experiments with DC SQUID amplifiers

    Science.gov (United States)

    Heaney, M. B.

    1990-11-01

    The development and fabrication of dc SQUIDs (Superconducting Quantum Interference Devices) with Nb/Al2O3/Nb Josephson junctions is described. A theory of the dc SQUID as a radio-frequency amplifier is presented, with an optimization strategy that accounts for the loading and noise contributions of the postamplifier and maximizes the signal-to-noise ratio of the total system. The high sensitivity of the dc SQUID is extended to high field NMR. A dc SQUID is used as a tuned radio-frequency amplifier to detect pulsed nuclear magnetic resonance at 32 MHz from a metal film in a 3.5 Tesla static field. A total system noise temperature of 11 K has been achieved, at a bath temperature of 4.2 K. The minimum number of nuclear Bohr magnetons observable from a free precession signal after a single pulse is about 2 x 10(exp 17) in a bandwidth of 25 kHz. In a separate experiment, a dc SQUID is used as a rf amplifier in a NQR experiment to observe a new resonance response mechanism. The net electric polarization of a NaClO3 crystal due to the precessing electric quadrupole moments of the Cl nuclei is detected at 30 MHz. The sensitivity of NMR and NQR spectrometers using dc SQUID amplifiers is compared to the sensitivity of spectrometers using conventional rf amplifiers. A SQUID-based spectrometer has a voltage sensitivity which is comparable to the best achieved by a FET-based spectrometer, at these temperatures and operating frequencies.

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

    Science.gov (United States)

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

    2017-02-28

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

  6. Multi-exponential inversions of nuclear magnetic resonance relaxation signal

    Institute of Scientific and Technical Information of China (English)

    WANG; Weimin(

    2001-01-01

    [1]Kenyon, W. E. , Petrophysical principles of applications of NMR logging, The Log Analyst, 1997, March-April: 21-43.[2]Timur, A., Producible porosity and permeability of sandstone investigated through nuclear magnetic resonance principles,Journal of Petroleum Technology, 1969, 21: 775-786.[3]Chakrabarty, T. , Longo, J. , A new method for mineral quantification to aid in hydrocarbon exploration and exploitation,Journal of Canadian Petroleum Technology, 1997, 36(11 ): 15-21.[4]Kleinberg, R. L. , Vinegar, H. J. , NMR properties of reservoir fluids, The Log Analyst, 1996, November-December: 20-32.[5]Wahba, G. , Practical approximate solutions to linear operator equations when the data are noisy, SIAM. J. Numer. Anal. ,1977, 14(4): 651-667.[6]Butler, J. P. , Reeds, J. A. , Dawson, S. V. , Estimating solutions of first kind integral equations with nonnegative constraints and optimal smoothing, SIAM J. Numer. Anal. , 1981, 18(3): 381-397.[7]Munn, K. , Smith, D. M., A NMR technique for the analysis of pore structure: Numerical inversion of relaxation measurements, Journal of Colloid and Interface Science, 1987,19(1): 117-126.[8]Provencher, S. W., A constrained regularization method for inverting data represented by linear algebraic or integral equations, Computer Physics Communications, 1982, 27: 213-227.[9]Bergman, D. J., Dunn, K. J., Magnetic susceptibility contrasted fixed field gradient effects on the spin-echo amplitude in a periodic porous media with diffusion, Phys. Soc., 1995, 40: 695-702.[10]Wang Weimin, The basic experiment studies of NMR logging, Well Logging Technology, 1997, 21 (6): 385-392.

  7. Nuclear magnetic resonance imaging of water content in the subsurface

    Energy Technology Data Exchange (ETDEWEB)

    J. Hendricks; T. Yao; A. Kearns

    1999-01-21

    Previous theoretical and experimental studies indicated that surface nuclear magnetic resonance (NMR) has the potential to provide cost-effective water content measurements in the subsurface and is a technology ripe for exploitation in practice. The objectives of this investigation are (a) to test the technique under a wide range of hydrogeological conditions and (b) to generalize existing NMR theories in order to correctly model NMR response from conductive ground and to assess properties of the inverse problem. Twenty-four sites with different hydrogeologic settings were selected in New Mexico and Colorado for testing. The greatest limitation of surface NMR technology appears to be the lack of understanding in which manner the NMR signal is influenced by soil-water factors such as pore size distribution, surface-to-volume ratio, paramagnetic ions dissolved in the ground water, and the presence of ferromagnetic minerals. Although the theoretical basis is found to be sound, several advances need to be made to make surface NMR a viable technology for hydrological investigations. There is a research need to investigate, under controlled laboratory conditions, how the complex factors of soil-water systems affect NMR relaxation times.

  8. Nuclear magnetic resonance studies of bovine γB-crystallin

    Science.gov (United States)

    Thurston, George; Mills, Jeffrey; Michel, Lea; Mathews, Kaylee; Zanet, John; Payan, Angel; van Nostrand, Keith; Kotlarchyk, Michael; Ross, David; Wahle, Christopher; Hamilton, John

    Anisotropy of shape and/or interactions play an important role in determining the properties of concentrated solutions of the eye lens protein, γB-crystallin, including its liquid-liquid phase transition. We are studying γB anisotropic interactions with use of nuclear magnetic resonance (NMR) concentration- and temperature-dependent chemical shift perturbations (CSPs). We analyze two-dimensional heteronuclear spin quantum coherence (HSQC) spectra on backbone nitrogen and attached hydrogen nuclei for CSPs, up to 3 percent volume fraction. Cumulative distribution functions of the CSPs show a concentration and temperature-dependent spread. Many peaks that are highly shifted with either concentration or temperature are close (i) crystal intermolecular contacts (ii) locations of cataractogenic point mutations of a homologous human protein, human γD-crystallin, and (iii) charged amino-acid residues. We also discuss the concentration- and temperature-dependence of NMR and quasielastic light scattering measurements of rotational and translational diffusion of γB crystallin in solution, affected by interprotein attractions. Supported by NIH EY018249.

  9. Two-dimensional nuclear magnetic resonance of quadrupolar systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuanhu

    1997-09-17

    This dissertation describes two-dimensional nuclear magnetic resonance theory and experiments which have been developed to study quadruples in the solid state. The technique of multiple-quantum magic-angle spinning (MQMAS) is extensively reviewed and expanded upon in this thesis. Specifically, MQMAS is first compared with another technique, dynamic-angle spinning (DAS). The similarity between the two techniques allows us to extend much of the DAS work to the MQMAS case. Application of MQMAS to a series of aluminum containing materials is then presented. The superior resolution enhancement through MQMAS is exploited to detect the five- and six-coordinated aluminum in many aluminosilicate glasses. Combining the MQMAS method with other experiments, such as HETCOR, greatly expands the possibility of the use of MQMAS to study a large range of problems and is demonstrated in Chapter 5. Finally, the technique switching-angle spinning (SAS) is applied to quadrupolar nuclei to fully characterize a quadrupolar spin system in which all of the 8 NMR parameters are accurately determined. This dissertation is meant to demonstrate that with the combination of two-dimensional NMR concepts and new advanced spinning technologies, a series of multiple-dimensional NMR techniques can be designed to allow a detailed study of quadrupolar nuclei in the solid state.

  10. Membrane proteins structure and dynamics by nuclear magnetic resonance.

    Science.gov (United States)

    Maltsev, Sergey; Lorigan, Gary A

    2011-10-01

    Membrane proteins represent a challenging class of biological systems to study. They are extremely difficult to crystallize and in most cases they retain their structure and functions only in membrane environments. Therefore, commonly used diffraction methods fail to give detailed molecular structure and other approaches have to be utilized to obtain biologically relevant information. Nuclear magnetic resonance (NMR) spectroscopy, however, can provide powerful structural and dynamical constraints on these complicated systems. Solution- and solid-state NMR are powerful methods for investigating membrane proteins studies. In this work, we briefly review both solution and solid-state NMR techniques for membrane protein studies and illustrate the applications of these methods to elucidate proteins structure, conformation, topology, dynamics, and function. Recent advances in electronics, biological sample preparation, and spectral processing provided opportunities for complex biological systems, such as membrane proteins inside lipid vesicles, to be studied faster and with outstanding quality. New analysis methods therefore have emerged, that benefit from the combination of sample preparation and corresponding specific high-end NMR techniques, which give access to more structural and dynamic information.

  11. Advances in Nuclear Magnetic Resonance for Drug Discovery

    Science.gov (United States)

    Powers, Robert

    2010-01-01

    Background Drug discovery is a complex and unpredictable endeavor with a high failure rate. Current trends in the pharmaceutical industry have exasperated these challenges and are contributing to the dramatic decline in productivity observed over the last decade. The industrialization of science by forcing the drug discovery process to adhere to assembly-line protocols is imposing unnecessary restrictions, such as short project time-lines. Recent advances in nuclear magnetic resonance are responding to these self-imposed limitations and are providing opportunities to increase the success rate of drug discovery. Objective/Method A review of recent advancements in NMR technology that have the potential of significantly impacting and benefiting the drug discovery process will be presented. These include fast NMR data collection protocols and high-throughput protein structure determination, rapid protein-ligand co-structure determination, lead discovery using fragment-based NMR affinity screens, NMR metabolomics to monitor in vivo efficacy and toxicity for lead compounds, and the identification of new therapeutic targets through the functional annotation of proteins by FAST-NMR. Conclusion NMR is a critical component of the drug discovery process, where the versatility of the technique enables it to continually expand and evolve its role. NMR is expected to maintain this growth over the next decade with advancements in automation, speed of structure calculation, in-cell imaging techniques, and the expansion of NMR amenable targets. PMID:20333269

  12. Dynamic nuclear magnetic resonance field sensing with part-per-trillion resolution

    Science.gov (United States)

    Gross, Simon; Barmet, Christoph; Dietrich, Benjamin E.; Brunner, David O.; Schmid, Thomas; Pruessmann, Klaas P.

    2016-12-01

    High-field magnets of up to tens of teslas in strength advance applications in physics, chemistry and the life sciences. However, progress in generating such high fields has not been matched by corresponding advances in magnetic field measurement. Based mostly on nuclear magnetic resonance, dynamic high-field magnetometry is currently limited to resolutions in the nanotesla range. Here we report a concerted approach involving tailored materials, magnetostatics and detection electronics to enhance the resolution of nuclear magnetic resonance sensing by three orders of magnitude. The relative sensitivity thus achieved amounts to 1 part per trillion (10-12). To exemplify this capability we demonstrate the direct detection and relaxometry of nuclear polarization and real-time recording of dynamic susceptibility effects related to human heart function. Enhanced high-field magnetometry will generally permit a fresh look at magnetic phenomena that scale with field strength. It also promises to facilitate the development and operation of high-field magnets.

  13. A comparison of MR elastography and {sup 31}P MR spectroscopy with histological staging of liver fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Godfrey, Edmund M. [St James' Hospital, Leeds (United Kingdom); St James' Hospital, Department of Radiology, Leeds (United Kingdom); Patterson, Andrew J.; Priest, Andrew N.; Davies, Susan E.; Joubert, Ilse; Krishnan, Anant S.; Shaw, Ashley S.; Alexander, Graeme J.; Allison, Michael E.; Griffiths, William J.H.; Gimson, Alexander E.S. [Addenbrooke' s Hospital, Cambridge (United Kingdom); Griffin, Nyree [St Thomas' s Hospital, London (United Kingdom); Lomas, David J. [University of Cambridge, Department of Radiology, Cambridge (United Kingdom)

    2012-12-15

    Conventional imaging techniques are insensitive to liver fibrosis. This study assesses the diagnostic accuracy of MR elastography (MRE) stiffness values and the ratio of phosphomonoesters (PME)/phosphodiesters (PDE) measured using {sup 31}P spectroscopy against histological fibrosis staging. The local research ethics committee approved this prospective, blinded study. A total of 77 consecutive patients (55 male, aged 49 {+-} 11.5 years) with a clinical suspicion of liver fibrosis underwent an MR examination with a liver biopsy later the same day. Patients underwent MRE and {sup 31}P spectroscopy on a 1.5 T whole body system. The liver biopsies were staged using an Ishak score for chronic hepatitis or a modified NAS fibrosis score for fatty liver disease. MRE increased with and was positively associated with fibrosis stage (Spearman's rank = 0.622, P < 0.001). PME/PDE was not associated with fibrosis stage (Spearman's rank = -0.041, p = 0.741). Area under receiver operating curves for MRE stiffness values were high (range 0.75-0.97). The diagnostic utility of PME/PDE was no better than chance (range 0.44-0.58). MRE-estimated liver stiffness increases with fibrosis stage and is able to dichotomise fibrosis stage groupings. We did not find a relationship between {sup 31}P MR spectroscopy and fibrosis stage. circle Magnetic resonance elastography (MRE) and MR spectroscopy can both assess the liver. (orig.)

  14. Novel nuclear magnetic resonance techniques for studying biological molecules

    Energy Technology Data Exchange (ETDEWEB)

    Laws, David Douglas [Univ. of California, Berkeley, CA (United States)

    2000-06-01

    Over the fifty-five year history of Nuclear Magnetic Resonance (NMR), considerable progress has been made in the development of techniques for studying the structure, function, and dynamics of biological molecules. The majority of this research has involved the development of multi-dimensional NMR experiments for studying molecules in solution, although in recent years a number of groups have begun to explore NMR methods for studying biological systems in the solid-state. Despite this new effort, a need still exists for the development of techniques that improve sensitivity, maximize information, and take advantage of all the NMR interactions available in biological molecules. In this dissertation, a variety of novel NMR techniques for studying biomolecules are discussed. A method for determining backbone (Φ/Ψ) dihedral angles by comparing experimentally determined 13Ca, chemical-shift anisotropies with theoretical calculations is presented, along with a brief description of the theory behind chemical-shift computation in proteins and peptides. The utility of the Spin-Polarization Induced Nuclear Overhauser Effect (SPINOE) to selectively enhance NMR signals in solution is examined in a variety of systems, as are methods for extracting structural information from cross-relaxation rates that can be measured in SPINOE experiments. Techniques for the production of supercritical and liquid laser-polarized xenon are discussed, as well as the prospects for using optically pumped xenon as a polarizing solvent. In addition, a detailed study of the structure of PrP 89-143 is presented. PrP 89-143 is a 54 residue fragment of the prion proteins which, upon mutation and aggregation, can induce prion diseases in transgenic mice. Whereas the structure of the wild-type PrP 89-143 is a generally unstructured mixture of α-helical and β-sheet conformers in the solid state, the aggregates formed from the PrP 89-143 mutants appear to be mostly β-sheet.

  15. Nuclear magnetic resonance of laser-polarized noble gases in molecules, materials and organisms

    Energy Technology Data Exchange (ETDEWEB)

    Goodson, Boyd McLean [Univ. of California, Berkeley, CA (United States)

    1999-12-01

    Conventional nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) are fundamentally challenged by the insensitivity that stems from the ordinarily low spin polarization achievable in even the strongest NMR magnets. However, by transferring angular momentum from laser light to electronic and nuclear spins, optical pumping methods can increase the nuclear spin polarization of noble gases by several orders of magnitude, thereby greatly enhancing their NMR sensitivity. This dissertation is primarily concerned with the principles and practice of optically pumped nuclear magnetic resonance (OPNMR). The enormous sensitivity enhancement afforded by optical pumping noble gases can be exploited to permit a variety of novel NMR experiments across many disciplines. Many such experiments are reviewed, including the void-space imaging of organisms and materials, NMR and MRI of living tissues, probing structure and dynamics of molecules in solution and on surfaces, and zero-field NMR and MRI.

  16. Quantification of lipoprotein profiles by nuclear magnetic resonance spectroscopy and multivariate data analysis

    DEFF Research Database (Denmark)

    Aru, Violetta; Lam, Chloie; Khakimov, Bekzod

    2017-01-01

    Lipoproteins and their subfraction profiles have been associated to diverse diseases including Cardio Vascular Disease (CVD). There is thus a great demand for measuring and quantifying the lipoprotein profile in an efficient and accurate manner. Nuclear Magnetic Resonance (NMR) spectroscopy...

  17. QED calculation of the nuclear magnetic shielding for hydrogen-like ions

    CERN Document Server

    Yerokhin, V A; Harman, Z; Keitel, C H

    2012-01-01

    We report an ab initio calculation of the shielding of the nuclear magnetic moment by the bound electron in hydrogen-like ions. This investigation takes into account several effects that have not been calculated before (electron self-energy, vacuum polarization, nuclear magnetization distribution), thus bringing the theory to the point where further progress is impeded by the uncertainty due to nuclear-structure effects. The QED corrections are calculated to all orders in the nuclear binding strength parameter and, independently, to the leading order in the expansion in this parameter. The results obtained lay the ground for the high-precision determination of nuclear magnetic dipole moments from measurements of the g-factor of hydrogen-like ions.

  18. Developing hyperpolarized krypton-83 for nuclear magnetic resonance spectroscopy and magnetic resonance imaging

    Science.gov (United States)

    Cleveland, Zackary I.

    This dissertation discusses the production of highly nonequilibrium nuclear spin polarization, referred to as hyperpolarization or hp, in the nuclear spin I = 9/2 noble gas isotope krypton-83 using spin exchange optical pumping (SEOP). This nonequilibrium polarization yields nuclear magnetic resonance (NMR) signals that are enhanced three or more orders of magnitude above those of thermally polarized krypton and enables experiments that would otherwise be impossible. Krypton-83 possesses a nuclear electric quadrupole moment that dominates the longitudinal (T1) relaxation due to coupling of the quadrupole moment to fluctuating electric field gradients generated by distortions to the spherical symmetry of the electronic environment. Relaxation slows polarization buildup and limits the maximum signal intensity but makes krypton-83 a sensitive probe of its environment. The gas-phase krypton-83 longitudinal relaxation rate increases linearly with total gas density due to binary collisions. Density independent relaxation, caused by the formation of krypton-krypton van der Waals molecules and surface adsorption, also contributes to the observed rate. Buffer gases suppress van der Waals molecule mediated relaxation by breaking apart the weakly bound krypton dimers. Surface relaxation is gas composition independent and therefore more difficult to suppress. However, this relaxation mechanism makes hp krypton-83 sensitive to important surface properties including surface-to-volume ratio, surface chemistry, and surface temperature. The presence of surfaces with high krypton adsorption affinities (i.e. hydrophobic surfaces) accelerates the relaxation times and can produce T1 contrast in hp krypton-83 magnetic resonance imaging (MRI). Tobacco smoke deposited on surfaces generates strong T1 contrast allowing the observation of smoke deposition with spatial resolution. Conversely, water adsorption on surfaces significantly lengths the T1 times due competitive surface adsorption

  19. Time-odd mean fields in the rotating frame microscopic nature of nuclear magnetism

    CERN Document Server

    Afanasiev, A V

    2000-01-01

    The microscopic role of nuclear magnetism in rotating frame is investigated for the first time in the framework of the cranked relativistic mean field theory. It is shown that nuclear magnetism modifies the expectation values of single-particle spin, orbital and total angular momenta along the rotational axis effectively creating additional angular momentum. This effect leads to the increase of kinematic and dynamic moments of inertia at given rotational frequency and has an impact on effective alignments.

  20. A Multidisciplinary Approach to High Throughput Nuclear Magnetic Resonance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Hossein Pourmodheji

    2016-06-01

    Full Text Available Nuclear Magnetic Resonance (NMR is a non-contact, powerful structure-elucidation technique for biochemical analysis. NMR spectroscopy is used extensively in a variety of life science applications including drug discovery. However, existing NMR technology is limited in that it cannot run a large number of experiments simultaneously in one unit. Recent advances in micro-fabrication technologies have attracted the attention of researchers to overcome these limitations and significantly accelerate the drug discovery process by developing the next generation of high-throughput NMR spectrometers using Complementary Metal Oxide Semiconductor (CMOS. In this paper, we examine this paradigm shift and explore new design strategies for the development of the next generation of high-throughput NMR spectrometers using CMOS technology. A CMOS NMR system consists of an array of high sensitivity micro-coils integrated with interfacing radio-frequency circuits on the same chip. Herein, we first discuss the key challenges and recent advances in the field of CMOS NMR technology, and then a new design strategy is put forward for the design and implementation of highly sensitive and high-throughput CMOS NMR spectrometers. We thereafter discuss the functionality and applicability of the proposed techniques by demonstrating the results. For microelectronic researchers starting to work in the field of CMOS NMR technology, this paper serves as a tutorial with comprehensive review of state-of-the-art technologies and their performance levels. Based on these levels, the CMOS NMR approach offers unique advantages for high resolution, time-sensitive and high-throughput bimolecular analysis required in a variety of life science applications including drug discovery.

  1. A Multidisciplinary Approach to High Throughput Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Pourmodheji, Hossein; Ghafar-Zadeh, Ebrahim; Magierowski, Sebastian

    2016-06-09

    Nuclear Magnetic Resonance (NMR) is a non-contact, powerful structure-elucidation technique for biochemical analysis. NMR spectroscopy is used extensively in a variety of life science applications including drug discovery. However, existing NMR technology is limited in that it cannot run a large number of experiments simultaneously in one unit. Recent advances in micro-fabrication technologies have attracted the attention of researchers to overcome these limitations and significantly accelerate the drug discovery process by developing the next generation of high-throughput NMR spectrometers using Complementary Metal Oxide Semiconductor (CMOS). In this paper, we examine this paradigm shift and explore new design strategies for the development of the next generation of high-throughput NMR spectrometers using CMOS technology. A CMOS NMR system consists of an array of high sensitivity micro-coils integrated with interfacing radio-frequency circuits on the same chip. Herein, we first discuss the key challenges and recent advances in the field of CMOS NMR technology, and then a new design strategy is put forward for the design and implementation of highly sensitive and high-throughput CMOS NMR spectrometers. We thereafter discuss the functionality and applicability of the proposed techniques by demonstrating the results. For microelectronic researchers starting to work in the field of CMOS NMR technology, this paper serves as a tutorial with comprehensive review of state-of-the-art technologies and their performance levels. Based on these levels, the CMOS NMR approach offers unique advantages for high resolution, time-sensitive and high-throughput bimolecular analysis required in a variety of life science applications including drug discovery.

  2. Nuclear magnetic resonance studies of macroscopic morphology and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Barrall, Geoffrey Alden [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1995-09-01

    Nuclear magnetic resonance techniques are traditionally used to study molecular level structure and dynamics with a noted exception in medically applied NMR imaging (MRI). In this work, new experimental methods and theory are presented relevant to the study of macroscopic morphology and dynamics using NMR field gradient techniques and solid state two-dimensional exchange NMR. The goal in this work is not to take some particular system and study it in great detail, rather it is to show the utility of a number of new and novel techniques using ideal systems primarily as a proof of principle. By taking advantage of the analogy between NMR imaging and diffraction, one may simplify the experiments necessary for characterizing the statistical properties of the sample morphology. For a sample composed of many small features, e.g. a porous medium, the NMR diffraction techniques take advantage of both the narrow spatial range and spatial isotropy of the sample`s density autocorrelation function to obtain high resolution structural information in considerably less time than that required by conventional NMR imaging approaches. The time savings of the technique indicates that NMR diffraction is capable of finer spatial resolution than conventional NMR imaging techniques. Radio frequency NMR imaging with a coaxial resonator represents the first use of cylindrically symmetric field gradients in imaging. The apparatus as built has achieved resolution at the micron level for water samples, and has the potential to be very useful in the imaging of circularly symmetric systems. The study of displacement probability densities in flow through a random porous medium has revealed the presence of features related to the interconnectedness of the void volumes. The pulsed gradient techniques used have proven successful at measuring flow properties for time and length scales considerably shorter than those studied by more conventional techniques.

  3. Nuclear magnetic resonance of D(-)-{alpha}-amino-benzyl penicillin; Ressonancia magnetica nuclear da D(-)-{alpha}-amino-benzil penicilina

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Monica R.M.P.; Gemal, Andre L.; San Gil, Rosane A.S. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Menezes, Sonia M.C. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    1995-12-31

    The development of new drugs from penicillins has induced the study of this substances by nuclear magnetic resonance. Several samples of D(-)-{alpha}-amino-benzyl penicillin were analysed using {sup 13} C NMR techniques in aqueous solution and solid state. Spectral data of this compounds were shown and the results were presented and analysed 7 figs., 4 tabs.

  4. Calculation of nuclear matter in the presence of strong magnetic field using LOCV technique

    CERN Document Server

    Bordbar, G H

    2015-01-01

    In the present work, we are interested in the properties of nuclear matter at zero temperature in the presence of strong magnetic fields using the lowest order constraint variational (LOCV) method employing $AV_{18}$ nuclear potential. Our results indicate that in the absence of a magnetic field, the energy per particle is a symmetric function of the spin polarization parameter. This shows that for the nuclear matter, the spontaneous phase transition to a ferromagnetic state does not occur. However, we have found that for the magnetic fields $ B\\gtrsim 10 ^ {18}\\ G$, the symmetry of energy is broken and the energy has a minimum at a positive value of the spin polarization parameter. We have also found that the effect of magnetic field on the value of energy is more significant at the low densities. Our calculations show that at lower densities, the spin polarization parameter is more sensitive to the magnetic field.

  5. Altered phospholipid metabolism in schizophrenia: a phosphorus 31 nuclear magnetic resonance spectroscopy study.

    Science.gov (United States)

    Weber-Fahr, Wolfgang; Englisch, Susanne; Esser, Andrea; Tunc-Skarka, Nuran; Meyer-Lindenberg, Andreas; Ende, Gabriele; Zink, Mathias

    2013-12-30

    Phospholipid (PL) metabolism is investigated by in vivo 31P magnetic resonance spectroscopy (MRS). Inconsistent alterations of phosphocholine (PC), phosphoethanolamine (PE), glycerophosphocholine (GPC) and glycerophosphoethanolamine (GPE) have been described in schizophrenia, which might be overcome by specific editing techniques. The selective refocused insensitive nuclei-enhanced polarization transfer (RINEPT) technique was applied in a cross-sectional study involving 11 schizophrenia spectrum disorder patients (SZP) on stable antipsychotic monotherapy and 15 matched control subjects. Metabolite signals were found to be modulated by cerebrospinal fluid (CSF) content and gray matter/brain matter ratio. Corrected metabolite concentrations of PC, GPC and PE differed between patients and controls in both subcortical and cortical regions, whereas antipsychotic medication exerted only small effects. Significant correlations were found between the severity of clinical symptoms and the assessed signals. In particular, psychotic symptoms correlated with PC levels in the cerebral cortex, depression with PC levels in the cerebellum and executive functioning with GPC in the insular and temporal cortices. In conclusion, after controlling for age and tissue composition, this investigation revealed alterations of metabolite levels in SZP and correlations with clinical properties. RINEPT 31P MRS should also be applied to at-risk-mental-state patients as well as drug-naïve and chronically treated schizophrenic patients in order to enhance the understanding of longitudinal alterations of PL metabolism in schizophrenia. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  6. Usefulness of waveform analysis of popliteal artery in Type Ⅱ diabetic patients using gated magnetic resonance 2D-cine-PC imaging and 31P spectros copy%利用门控磁共振2D-cine-PC显像和31P扫描分析Ⅱ型糖尿病患者动脉波形的有用性

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ 缺血、神经功能紊乱、足底机械力学异常是糖尿病足病变的易患因素.灌注压低、动脉阻力高使下肢血供差,处于缺血状态,导致足部皮下、肌肉组织损伤.因此,对下肢周围循环进行评估有助于明确易发生足部病变的高危患者. 超声检查、踝/臂比值的测定、体积描记法、经皮测定足背氧张力和温度描记法常用来评估下肢周围循环血流动力学改变.然而,由于各种全身和局部因素,如足部骨密度高、血管壁钙化、皮肤增厚、炎症或局限性水肿等,使这些方法都有一定的局限性.而这些情况在合并足病变的糖尿病患者身上尤其常见.动脉造影可用来了解周围动脉的形态改变,但由于造影剂有肾毒性,常不能用于有并发症的糖尿病患者.磁共振血管成像不使用造影剂,为通过较厚的组织了解深部血管以及走行范围较大的单支血管形态异常提供了一个好方法.最近,我们报道了1H和31P磁共振扫描成像对糖尿病神经性足溃疡是一个有价值的新诊断方 法,而且门控磁共振二维时差成像可提供血流方向、速度和容量等数据. 本研究的目的是使用门控磁共振2D-cine-PC成像和动脉血流分析技术了解下肢闭塞性动脉病变或动脉阻力增高所致的异常的周围循环.同时对这些结果进行分析,通过31P 磁共振扫描以了解足底肌肉的能量代谢,有助于确定易发生足病变的病危患者.

  7. 核磁共振磷谱在有机化合物草甘膦合成过程中的监控%The Application of 31^P-NMR Spectrum in Monitoring the Synthesis of Glyphosate

    Institute of Scientific and Technical Information of China (English)

    赵黎黎; 王敏; 钟江春; 林吉柏

    2012-01-01

    The 31^P-NMR is one of important technologies of Nuclear magnetic resonance; it plays a very important role in the quality and quantity of compound in organic chemistry and monitoring the synthesis. The article makes a brief introduction for the tested method in the Synthesis of Glyphosate by 31^P-NMR to supply a reference for the application of NMR in the field of organic pesticide.%磷谱是核磁共振的一项重要应用,它在有机化学的定性、定量以及合成过程的监控实验中具有非常重要的作用。本文开发了利用核磁共振磷谱进行有机农药草甘磷部分合成过程监控的实验方法。为草甘膦质量控制和品质提升提供方法支持,同时为进一步扩大核磁共振在有机农药化合物研究领域中的应用提供参考。

  8. Oxidative stress-induced metabolic changes in mouse C2C12 myotubes studied with high-resolution 13C, 1H, and 31P NMR spectroscopy.

    Science.gov (United States)

    Straadt, Ida K; Young, Jette F; Petersen, Bent O; Duus, Jens Ø; Gregersen, Niels; Bross, Peter; Oksbjerg, Niels; Theil, Peter K; Bertram, Hanne C

    2010-02-10

    In this study, stress in relation to slaughter was investigated in a model system by the use of (13)C, (1)H, and (31)P nuclear magnetic resonance (NMR) spectroscopy for elucidating changes in the metabolites in C2C12 myotubes exposed to H(2)O(2)-induced stress. Oxidative stress resulted in lower levels of several metabolites, mainly amino acids; however, higher levels of alanine were apparent in the (13)C spectra after incubation with [(13)C(1)]glucose. In the (13)C spectra [(13)C(3)]lactate tended to increase after exposure to increasing concentrations of H(2)O(2); conversely, a tendency to lower levels of the unlabeled ((12)C) lactate were identified in the (1)H spectra after stress exposure. These data indicate an increase in de novo synthesis of alanine, concomitant with a release of lactate from the myotubes to the medium at oxidative stress conditions. The changes in the metabolite levels could possibly be useful as markers for meat quality traits.

  9. Intra- and extracellular pH of the brain in vivo studied by 31P-NMR during hyper- and hypocapnia

    DEFF Research Database (Denmark)

    Portman, M A; Lassen, N A; Cooper, T G

    1991-01-01

    .05 for extracellular pH (pHe) vs. arterial pH, 0.43 +/- 0.078 for intracellular pH (pHi) vs. pHe, and 0.23 +/- 0.056 for pHi vs. arterial pH. These data indicate that CO2 buffering capacity is different and decreases from the intracellular to extracellular to arterial blood compartments. Separation......Studies were performed to determine the pH relationships among the extracellular, intracellular, and arterial blood compartments in the brain in vivo. Resolution of the extracellular monophosphate resonance peak from the intracellular peak in 31P nuclear magnetic resonance (NMR) spectra of sheep...... brain with the calvarium intact enabled pH measurement in these respective compartments. Sheep were then subjected to both hyper- and hypoventilation, which resulted in a wide range of arterial PCO2 and pH values. Linear regression analysis of pH in these compartments yielded slopes of 0.56 +/- 0...

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

    Science.gov (United States)

    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.

  11. 31P-MRS of skeletal muscle is not a sensitive diagnostic test for mitochondrial myopathy

    DEFF Research Database (Denmark)

    Jeppesen, Tina Dysgaard; Quistorff, Bjørn; Wibrand, Flemming

    2007-01-01

    impaired citrate synthase-corrected complex I activity. Resting PCr/P(i) ratio and leg P(i) recovery were lower in MM patients vs. healthy subjects. PCr and ATP production after exercise were similar in patients and healthy subjects. Although the specificity for MM of some (31)P-MRS variables was as high...... as 100%, the sensitivity was low (0-63%) and the diagnostic strength of (31)P-MRS was inferior to the other diagnostic tests for MM. Thus, (31)P-MRS should not be a routine test for MM, but may be an important research tool....

  12. Surface chemistry of group 11 atomic layer deposition precursors on silica using solid-state nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Pallister, Peter J.; Barry, Seán T.

    2017-02-01

    The use of chemical vapour deposition (CVD) and atomic layer deposition (ALD) as thin film deposition techniques has had a major impact on a number of fields. The deposition of pure, uniform, conformal thin films requires very specific vapour-solid reactivity that is largely unknown for the majority of ALD and CVD precursors. This work examines the initial chemisorption of several thin film vapour deposition precursors on high surface area silica (HSAS) using 13C, 31P, and quantitative 29Si nuclear magnetic resonance spectroscopy (NMR). Two copper metal precursors, 1,3-diisopropyl-imidazolin-2-ylidene copper (I) hexamethyldisilazide (1) and 1,3-diethyl-imidazolin-2-ylidene copper(I) hexamethyldisilazide (2), and one gold metal precursor, trimethylphosphine gold(III) trimethyl (3), are examined. Compounds 1 and 2 were found to chemisorb at the hydroxyl surface-reactive sites to form a ||-O-Cu-NHC surface species and fully methylated silicon (||-SiMe3, due to reactivity of the hexamethyldisilazane (HMDS) ligand on the precursor) at 150 °C and 250 °C. From quantitative 29Si solid-state NMR (SS-NMR) spectroscopy measurements, it was found that HMDS preferentially reacts at geminal disilanol surface sites while the copper surface species preferentially chemisorbed to lone silanol surface species. Additionally, the overall coverage was strongly dependent on temperature, with higher overall coverage of 1 at higher temperature but lower overall coverage of 2 at higher temperature. The chemisorption of 3 was found to produce a number of interesting surface species on HSAS. Gold(III) trimethylphosphine, reduced gold phosphine, methylated phosphoxides, and graphitic carbon were all observed as surface species. The overall coverage of 3 on HSAS was only about 10% at 100 °C and, like the copper compounds, had a preference for lone silanol surface reactive sites. The overall coverage and chemisorbed surface species have implications to the overall growth rate and purity of

  13. Nuclear magnetic resonance at millitesla fields using a zero-field spectrometer

    Science.gov (United States)

    Tayler, Michael C. D.; Sjolander, Tobias F.; Pines, Alexander; Budker, Dmitry

    2016-09-01

    We describe new analytical capabilities for nuclear magnetic resonance (NMR) experiments in which signal detection is performed with chemical resolution (via spin-spin J couplings) in the zero to ultra-low magnetic field region, below 1 μT. Using magnetic fields in the 100 μT to 1 mT range, we demonstrate the implementation of conventional NMR pulse sequences with spin-species selectivity.

  14. Development and applications of NMR (nuclear magnetic resonance) in low fields and zero field

    Energy Technology Data Exchange (ETDEWEB)

    Bielecki, A.

    1987-05-01

    This dissertation is about nuclear magnetic resonance (NMR) spectroscopy in the absence of applied magnetic fields. NMR is usually done in large magnetic fields, often as large as can be practically attained. The motivation for going the opposite way, toward zero field, is that for certain types of materials, particularly powdered or polycrystalline solids, the NMR spectra in zero field are easier to interpret than those obtained in high field. 92 refs., 60 figs., 1 tab.

  15. Nuclear ground-state spin and magnetic moment of 21Mg

    CERN Document Server

    Krämer, J; De Rydt, M; Flanagan, K T; Geppert, Ch; Kowalska, M; Lievens, P; Neugart, R; Neyens, G; Nörtershäuser, W; Stroke, H H; Vingerhoets, P; Yordanov, D T

    2009-01-01

    We present the results of combined laser spectroscopy and nuclear magnetic resonance studies of 21Mg. The nuclear ground-state spin was measured to be I=5/2 with a magnetic moment of μ=−0.983(7)μN. The isoscalar magnetic moment of the mirror pair is evaluated and compared to the extreme single-particle prediction and to nuclear shell-model calculations. We determine an isoscalar spin expectation value of σ=1.15(2), which is significantly greater than the empirical limit of unity given by the Schmidt values of the magnetic moments. Shell-model calculations taking into account isospin non-conserving effects, are in agreement with our experimental results.

  16. Coexistence of phases in asymmetric nuclear matter under strong magnetic fields

    CERN Document Server

    Aguirre, R

    2014-01-01

    The equation of state of nuclear matter is strongly affected by the presence of a magnetic field. Here we study the equilibrium configuration of asymmetric nuclear matter for a wide range of densities, isospin composition, temperatures and magnetic fields. Special attention is paid to the low density and low temperature domain, where a thermodynamical instability exists. Neglecting fluctuations of the Coulomb force, a coexistence of phases is found under such conditions, even for extreme magnetic intensities. We describe the nuclear interaction by using the non--relativistic Skyrme potential model within a Hartree--Fock approach. We found that the coexistence of phases modifies the equilibrium configuration, masking most of the manifestations of the spin polarized matter. However, the compressibility and the magnetic susceptibility show clear signals of this fact. Thermal effects are significative for both quantities, mainly out of the coexistence region.

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

    Science.gov (United States)

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

    2000-10-01

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

  18. Solid-state NMR (31)P paramagnetic relaxation enhancement membrane protein immersion depth measurements.

    Science.gov (United States)

    Maltsev, Sergey; Hudson, Stephen M; Sahu, Indra D; Liu, Lishan; Lorigan, Gary A

    2014-04-24

    Paramagnetic relaxation enhancement (PRE) is a widely used approach for measuring long-range distance constraints in biomolecular solution NMR spectroscopy. In this paper, we show that (31)P PRE solid-state NMR spectroscopy can be utilized to determine the immersion depth of spin-labeled membrane peptides and proteins. Changes in the (31)P NMR PRE times coupled with modeling studies can be used to describe the spin-label position/amino acid within the lipid bilayer and the corresponding helical tilt. This method provides valuable insight on protein-lipid interactions and membrane protein structural topology. Solid-state (31)P NMR data on the 23 amino acid α-helical nicotinic acetylcholine receptor nAChR M2δ transmembrane domain model peptide followed predicted behavior of (31)P PRE rates of the phospholipid headgroup as the spin-label moves from the membrane surface toward the center of the membrane. Residue 11 showed the smallest changes in (31)P PRE (center of the membrane), while residue 22 shows the largest (31)P PRE change (near the membrane surface), when compared to the diamagnetic control M2δ sample. This PRE SS-NMR technique can be used as a molecular ruler to measure membrane immersion depth.

  19. 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

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R.E.; Smith, D.L. [Argonne National Lab., IL (United States). Technology Development Div.

    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.

  20. Nuclear magnetic resonance applied to the study of polymeric nano composites; Ressonancia magnetica nuclear aplicada do estudo de nanocompositos polimericos

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Maria Ines Bruno [Instituto de Macromoleculas Professora Eloisa Mano da Universidade Federal do Rio de Janeiro, UFRJ - RJ (Brazil)

    2011-07-01

    Polymers and nanoparticles based nano composites were prepared by intercalation by solution. The obtained nano composites were characterized mainly by the nuclear magnetic spectroscopy (NMR), applying the analysis of carbon-13 (polymeric matrix), silicon-29 (nanoparticle), and by determination of spin-lattice relaxation of the hydrogen nucleus (T{sub 1}H) (polymeric matrix). The NMR have presented a promising technique in the characterization of the nano charge dispersion in the studied polymeric matrixes.

  1. 新型有机磷阻燃剂的31P NMR分析%The Analysis of the 31P NMR of Novel Organic Phosphorus Flame Retardants

    Institute of Scientific and Technical Information of China (English)

    王小芳; 范润兰; 王利生

    2008-01-01

    利用31P核磁共振仪对7种新型有机磷阻燃剂(CEPPA、DPPA、ODOPB、TODP、PPDC、PPDCO和DCPP)进行了测定和分析,提供了这些阻燃剂的31P NMR化学位移数据,这些数据可用于鉴定阻燃剂结构,通过峰的数量及面积可测定阻燃剂的纯度和杂质含量.结果表明31P NMR分析是检验有机磷阻燃剂纯度的有效方法.

  2. COMPRESSION GARMENTS AND RECOVERY FROM ECCENTRIC EXERCISE: A 31P-MRS STUDY

    Directory of Open Access Journals (Sweden)

    Michael I. Trenell

    2006-03-01

    Full Text Available The low oxidative demand and muscular adaptations accompanying eccentric exercise hold benefits for both healthy and clinical populations. Compression garments have been suggested to reduce muscle damage and maintain muscle function. This study investigated whether compression garments could benefit metabolic recovery from eccentric exercise. Following 30-min of downhill walking participants wore compression garments on one leg (COMP, the other leg was used as an internal, untreated control (CONT. The muscle metabolites phosphomonoester (PME, phosphodiester (PDE, phosphocreatine (PCr, inorganic phosphate (Pi and adenosine triphosphate (ATP were evaluated at baseline, 1-h and 48-h after eccentric exercise using 31P-magnetic resonance spectroscopy. Subjective reports of muscle soreness were recorded at all time points. The pressure of the garment against the thigh was assessed at 1-h and 48-h following exercise. There was a significant increase in perceived muscle soreness from baseline in both the control (CONT and compression (COMP leg at 1-h and 48-h following eccentric exercise (p < 0.05. Relative to baseline, both CONT and COMP showed reduced pH at 1-h (p < 0.05. There was no difference between CONT and COMP pH at 1-h. COMP legs exhibited significantly (p < 0.05 elevated skeletal muscle PDE 1-h following exercise. There was no significant change in PCr/Pi, Mg2+ or PME at any time point or between CONT and COMP legs. Eccentric exercise causes disruption of pH control in skeletal muscle but does not cause disruption to cellular control of free energy. Compression garments may alter potential indices of the repair processes accompanying structural damage to the skeletal muscle following eccentric exercise allowing a faster cellular repair

  3. Muscle energetics changes throughout maturation: a quantitative 31P-MRS analysis.

    Science.gov (United States)

    Tonson, Anne; Ratel, Sébastien; Le Fur, Yann; Vilmen, Christophe; Cozzone, Patrick J; Bendahan, David

    2010-12-01

    We quantified energy production in 7 prepubescent boys (11.7 ± 0.6 yr) and 10 men (35.6 ± 7.8 yr) using (31)P-magnetic resonance spectroscopy to investigate whether development affects muscle energetics, given that resistance to fatigue has been reported to be larger before puberty. Each subject performed a finger flexions exercise at 0.7 Hz against a weight adjusted to 15% of their maximal voluntary strength for 3 min, followed by a 15-min recovery period. The total energy cost was similar in both groups throughout the exercise bout, whereas the interplay of the different metabolic pathways was different. At the onset of exercise, children exhibited a higher oxidative contribution (50 ± 15% in boys and 25 ± 8% in men, P contribution was reduced (40 ± 10% in boys and 53 ± 12% in men, P mechanism. The anaerobic glycolysis activity was unaffected by maturation. The recovery phase also disclosed differences regarding the rates of proton efflux (6.2 ± 2.5 vs. 3.8 ± 1.9 mM · pH unit(-1) · min(-1), in boys and men, respectively, P < 0.05), and phosphocreatine recovery, which was significantly faster in boys than in men (rate constant of phosphocreatine recovery: 1.3 ± 0.5 vs. 0.7 ± 0.4 min(-1); V(max): 37.5 ± 14.5 vs. 21.1 ± 12.2 mM/min, in boys and men, respectively, P < 0.05). Our results obtained in vivo clearly showed that maturation affects muscle energetics. Children relied more on oxidative metabolism and less on creatine kinase reaction to meet energy demand during exercise. This phenomenon can be explained by a greater oxidative capacity, probably linked to a higher relative content in slow-twitch fibers before puberty.

  4. (129) Xe and (131) Xe nuclear magnetic dipole moments from gas phase NMR spectra.

    Science.gov (United States)

    Makulski, Włodzimierz

    2015-04-01

    (3) He, (129) Xe and (131) Xe NMR measurements of resonance frequencies in the magnetic field B0=11.7586 T in different gas phase mixtures have been reported. Precise radiofrequency values were extrapolated to the zero gas pressure limit. These results combined with new quantum chemical values of helium and xenon nuclear magnetic shielding constants were used to determine new accurate nuclear magnetic moments of (129) Xe and (131) Xe in terms of that of the (3) He nucleus. They are as follows: μ((129) Xe) = -0.7779607(158)μN and μ((131) Xe) = +0.6918451(70)μN . By this means, the new 'helium method' for estimations of nuclear dipole moments was successfully tested. Gas phase NMR spectra demonstrate the weak intermolecular interactions observed on the (3) He and (129) Xe and (131) Xe shielding in the gaseous mixtures with Xe, CO2 and SF6 .

  5. Wilson's disease: {sup 31}P and {sup 1}H MR spectroscopy and clinical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Sanjib; Taly, A.B.; Prashanth, L.K. [National Institute of Mental Health and Neurosciences (NIMHANS), Department of Neurology, Bangalore (India); Ravishankar, S.; Vasudev, M.K. [National Institute of Mental Health and Neurosciences (NIMHANS), Department of Neuroimaging and Interventional Radiology, Bangalore (India)

    2010-11-15

    Proton ({sup 1}H) magnetic resonance spectroscopy (MRS) changes are noted in Wilson's disease (WD). However, there are no studies regarding membrane phospholipid abnormality using {sup 31}P MRS in these patients. We aimed to analyze the striatal spectroscopic abnormalities using {sup 31}P and {sup 1}H MRS in WD. Forty patients of WD (treated, 29; untreated,11) and 30 controls underwent routine MR image sequences and in vivo 2-D {sup 31}P and {sup 1}H MRS of basal ganglia using an image-selected technique on a 1.5-T MRI scanner. Statistical analysis was done using Student's t test. The mean durations of illness and treatment were 6.2 {+-} 7.4 and 4.8 {+-} 5.9 years, respectively. MRI images were abnormal in all the patients. {sup 1}H MRS revealed statistically significant reduction of N-acetyl aspartate (NAA)/choline (Cho) and NAA/creatine ratios in striatum ({sup 1}H MRS) of treated patients compared to controls. The mean values of phosphomonoesters (PME) (p < 0.0001), phosphodiesters (PDE) (p < 0.0001), and total phosphorus (TPh) (p < 0.0001) were elevated in patients compared to controls. Statistically significant elevated levels of ratio of PME/PDE (p = 0.05) observed in the striatum were noted in treated patients as compared to controls in the {sup 31}P MRS study. The duration of illness correlated well with increased PME/PDE [p < 0.001], PME/TPh [p < 0.05], and PDE/TPh [p < 0.05] and decreased NAA/Cho [p < 0.05] ratios. There was correlation of MRI score and reduced NAA/Cho ratio with disease severity. The PME/PDE ratio (right) was elevated in the treated group [p < 0.001] compared to untreated group. There is reduced breakdown and/or increased synthesis of membrane phospholipids and increased neuronal damage in basal ganglia in patients with WD. (orig.)

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

    Directory of Open Access Journals (Sweden)

    Alexander C Phillips

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

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

    Science.gov (United States)

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

    2013-01-01

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

  8. Nuclear structure in strong magnetic fields: nuclei in the crust of a magnetar

    CERN Document Server

    Arteaga, Daniel Pena; Khan, Elias; Ring, Peter

    2011-01-01

    Covariant density functional theory is used to study the effect of strong magnetic fields, up to the limit predicted for neutron stars (for magnetars $B \\approx10^{18}$G), on nuclear structure. All new terms in the equation of motion resulting from time reversal symmetry breaking by the magnetic field and the induced currents, as well as axial deformation, are taken into account in a self-consistent fashion. For nuclei in the iron region of the nuclear chart it is found that fields in the order of magnitude of $10^{17}$G significantly affect bulk properties like masses and radii.

  9. Anomalous hyperfine coupling and nuclear magnetic relaxation in Weyl semimetals

    Science.gov (United States)

    Okvátovity, Zoltán; Simon, Ferenc; Dóra, Balázs

    2016-12-01

    The electron-nuclear hyperfine interaction shows up in a variety of phenomena including, e.g., NMR studies of correlated states and spin decoherence effects in quantum dots. Here we focus on the hyperfine coupling and the NMR spin relaxation time T1 in Weyl semimetals. Since the density of states in Weyl semimetals varies with the square of the energy around the Weyl point, a naive power counting predicts a 1 /T1T ˜E4 scaling, with E the maximum of temperature (T ) and chemical potential. By carefully investigating the hyperfine interaction between nuclear spins and Weyl fermions, we find that while its spin part behaves conventionally, its orbital part diverges unusually, with the inverse of the energy around the Weyl point. Consequently, the nuclear spin relaxation rate scales in a graphenelike manner as 1 /T1T ˜E2ln(E /ω0) , with ω0 the nuclear Larmor frequency. This allows us to identify an effective hyperfine coupling constant, which is tunable by gating or doping. This is relevant for the decoherence effect in spintronics devices and double quantum dots, where hyperfine coupling is the dominant source of spin-blockade lifting.

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

    Science.gov (United States)

    Vyssotski, Mikhail; MacKenzie, Andrew; Scott, Dawn

    2009-04-01

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

  11. 31P Solid-state NMR based monitoring of permeation of cell penetrating peptides into skin

    Science.gov (United States)

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

    2013-01-01

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

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

    Science.gov (United States)

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

    2014-02-01

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

  13. Nuclear magnetic resonance study of pure and Ni/Co doped LiFeAs

    Energy Technology Data Exchange (ETDEWEB)

    Grafe, Hans-Joachim; Baek, Seung-Ho; Hammerath, Franziska; Graefe, Uwe; Utz, Yannic; Harnagea, L.; Nacke, Claudia; Aswartham, Saicharan; Wurmehl, Sabine; Buechner, Bernd [Leibniz-Institut fuer Festkoerper- und Werkstoffforschung, Dresden (Germany)

    2011-07-01

    We present Nuclear Magnetic and Nuclear Quadrupole Resonance (NMR/NQR) measurements on pure, Ni and Co doped LiFeAs single crystals. The parent compound LiFeAs exhibits unconventional superconductivity with a transition temperature of about 17 K. Unlike other Fe based superconductors, where superconductivity is induced or stabilized by Co or Ni doping, replacement of Fe by these elements leads to a suppression of the superconducting transition temperature in LiFeAs. In case of Ni doping, a bulk magnetic order is induced below about 160 K. In contrast, for Co doping, the superconducting transition temperature is only reduced, but no magnetic order is observed. We discuss the nature and the origin of this magnetic order and its relation to unconventional superconductivity in pure LiFeAs.

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

    Science.gov (United States)

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

    2016-01-01

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

  15. Zero and Ultra-Low-Field Nuclear Magnetic Resonance Spectroscopy Via Optical Magnetometry

    Science.gov (United States)

    Blanchard, John Woodland

    Nuclear magnetic resonance (NMR) is among the most powerful analytical tools available to the chemical and biological sciences for chemical detection, characterization, and structure elucidation. NMR experiments are usually performed in large magnetic fields in order to maximize sensitivity and increase chemical shift resolution. However, the high magnetic fields required for conventional NMR necessitate large, immobile, and expensive superconducting magnets, limiting the use of the technique. New hyperpolarization and non-inductive detection methods have recently allowed for NMR measurements in the inverse regime of extremely low magnetic fields. Whereas a substantial body of research has been conducted in the high-field regime, taking advantage of the efficient coherent control afforded by a spectroscopy dominated by coupling to the spectrometer, the zero- and ultra-low-field (ZULF) regime has remained mostly unexplored. In this dissertation, we investigate the applicability of ZULF-NMR as a novel spectroscopic technique complimentary to high-field NMR. In particular, we consider various aspects of the ZULF-NMR experiment and the dynamics of nuclear spins under various local spin coupling Hamiltonians. We first survey zero-field NMR experiments on systems dominated by the electron-mediated indirect spin-spin coupling (J-coupling). The resulting J-spectra permit precision measurement of chemically relevant information due to the exquisite sensitivity of J-couplings to subtle changes in molecular geometry and electronic structure. We also consider the effects of weak magnetic fields and residual dipolar couplings in anisotropic media, which encode information about nuclear magnetic moments and geometry, and further resolve topological ambiguities by lifting degeneracies. By extending the understanding of the interactions that contribute to ZULF-NMR spectra, this work represents a significant advancement towards a complete description of zero- and ultra

  16. High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HRMAS NMR) for Studies of Reactive Fabrics

    Science.gov (United States)

    2015-11-01

    Magnetic Resonance (HRMAS NMR) for Studies of Reactive Fabrics 5a. CONTRACT NUMBER W911SR-11-C-0047 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...ECBC-TR-1326 HIGH RESOLUTION MAGIC ANGLE SPINNING NUCLEAR MAGNETIC RESONANCE (HRMAS NMR) FOR STUDIES OF REACTIVE FABRICS David J. McGarvey...unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT An analytical chemistry method is described for measuring the reactivity and permeation of

  17. Monte Carlo Simulation of Adiabatic Cooling and Nuclear Magnetism

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker; Viertiö, H. E.; Mouritsen, Ole G.

    1988-01-01

    constant-temperature or constant-magnetic-field quenches into the antiferromagnetic phase is found at late times to obey the classical Allen-Cahn growth law. The qualitative features of isentropic quenches and the nonequilibrium ordering phenomena during controlled heating treatments at constant rate...

  18. Estudo do metabolismo energético muscular em atletas por 31P-ERM Muscular energetic metabolism study in athletes by 31P-MRS

    Directory of Open Access Journals (Sweden)

    Maria Gisele dos Santos

    2004-04-01

    Full Text Available OBJETIVO: Caracterizar as reservas energéticas de metabólitos fosforilados no músculo esquelético de atletas mediante 31P-ERM. MÉTODOS: Amostra deste estudo foi formada por 14 atletas de alto nível do Centro de Alto Rendimento Esportivo (CAR, Sant Cugat del Vallés, Espanha. O padrão de metabólitos fosforilados foi medido no músculo vasto medial por 31P-ERM. A suplementação oral foi realizada durante 14 dias, na forma de 20g de monohidrato de creatina. Os atletas foram determinados conforme as suas características físicas (peso, altura, índice de massa corporal (IMC, consumo máximo de oxigênio (VO2 Max. em dois grupos: placebo (maltodextrina e suplementação com creatina. O protocolo de exercício foi realizado no interior do túnel de ressonância (160 x 52 cm, a 60 ciclos por minuto para ambas as pernas. RESULTADOS: Os resultados demonstraram um aumento significativo da fosfocreatina (PCr durante o exercício, após o período de suplementação, denotando uma redução do seu consumo no grupo que recebeu suplementação com creatina; não houve diminuição significativa do pH intracelular e fosfato inorgânico após a suplementação. CONCLUSÃO: O protocolo de exercício realizado pelos fundistas no Centro de Diagnóstico de Pedralbes permitiu detectar mediante 31P-ERM, no grupo que foi suplementado com creatina, uma diminuição do consumo de PCr durante os períodos de exercício.BACKGROUND: The aim of this study was to characterize the muscular reservoirs of phosphorilated energetic components of athletes using 31P-MRS. METHODS: The sample was formed by 14 elite athletes from the Center for High Sportive Performance (CAR, Sant Cugat del Vallés, Spain. The pattern of the phosphorilated metabolites was measured from the muscle vastus medialis by 31P-MRS. Oral supplementation of 20 g of Creatine monohydrate was given during 14 days. Two groups of athletes were formed according to their physical characteristics (weight

  19. High-pass bird-cage coil for nuclear-magnetic resonance

    Science.gov (United States)

    Watkins, Joel C.; Fukushima, Eiichi

    1988-06-01

    Cylindrical bird-cage coils generate uniform magnetic fields transverse to the cylinder axis for use in the large sample nuclear-magnetic resonance (NMR) experiments. We describe the design and construction of an eight-rung high-pass bird-cage coil to operate at 80 MHz in a cylindrical bore of a superconducting magnet. The coil is 12.7 cm in diameter by 30.5 cm long and has a 7-cm-diam region in the center where the field intensity is within 10% of the average.

  20. Impact of steam explosion on the wheat straw lignin structure studied by solution-state nuclear magnetic resonance and density functional methods.

    Science.gov (United States)

    Heikkinen, Harri; Elder, Thomas; Maaheimo, Hannu; Rovio, Stella; Rahikainen, Jenni; Kruus, Kristiina; Tamminen, Tarja

    2014-10-29

    Chemical changes of lignin induced by the steam explosion (SE) process were elucidated. Wheat straw was studied as the raw material, and lignins were isolated by the enzymatic mild acidolysis lignin (EMAL) procedure before and after the SE treatment for analyses mainly by two-dimensional (2D) [heteronuclear single-quantum coherence (HSQC) and heteronuclear multiple-bond correlation (HMBC)] and (31)P nuclear magnetic resonance (NMR). The β-O-4 structures were found to be homolytically cleaved, followed by recoupling to β-5 linkages. The homolytic cleavage/recoupling reactions were also studied by computational methods, which verified their thermodynamic feasibility. The presence of the tricin bound to wheat straw lignin was confirmed, and it was shown to participate in lignin reactions during the SE treatment. The preferred homolytic β-O-4 cleavage reaction was calculated to follow bond dissociation energies: G-O-G (guaiacyl) (69.7 kcal/mol) > G-O-S (syringyl) (68.4 kcal/mol) > G-O-T (tricin) (67.0 kcal/mol).

  1. Characterization of very young mineral phases of bone by solid state 31phosphorus magic angle sample spinning nuclear magnetic resonance and X-ray diffraction.

    Science.gov (United States)

    Roberts, J E; Bonar, L C; Griffin, R G; Glimcher, M J

    1992-01-01

    The properties of bone mineral change with age and maturation. Several investigators have suggested the presence of an initial or "precursor" calcium phosphate phase to help explain these differences. We have used solid state 31P magic angle sample spinning (MASS) nuclear magnetic resonance (NMR) and X-ray radial distribution function (RDF) analyses to characterize 11- and 17-day-old embryonic chick bone and fractions obtained from them by density fractionation. Density fractionation provides samples of bone containing Ca-P solid-phase deposits even younger and more homogeneous with respect to the age of mineral than the calcium phosphate (Ca-P) deposits in the whole bone samples. The analytical techniques yield no evidence for any distinct phase other than the poorly crystalline hydroxyapatite phase characteristic of mature bone mineral. In particular, there is no detectable crystalline brushite [DCPD, CaHPO4 2H2O less than 1%] or amorphous calcium phosphate (less than 8-10%) in the most recently formed bone mineral. A sizeable portion of the phosphate groups exist as HPO4(2-) in a brushite (DCPD)-like configuration. These acid phosphate moieties are apparently incorporated into the apatitic lattice. The most likely site for the brushite-like configuration is probably on the surface of the crystals.

  2. Detection of phosphorus species in sediments of artificial landscape lakes in China by fractionation and phosphorus-31 nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu Jinyong [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Wang Hui [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China)], E-mail: wanghui@tsinghua.edu.cn; Yang Haijun [Department of Chemistry, Tsinghua University, Beijing 100084 (China); Ma Yanjun; Cai Ouchen [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2009-01-15

    Phosphorus (P) pollution in the sediments of seven artificial landscape lakes was studied via fractionation and phosphorus-31 nuclear magnetic resonance ({sup 31}P NMR) spectroscopy. The lake sediments accumulated significant amounts of P from supplementation with reclaimed water and from runoff from the golf course lawns. The differences in total sediment P among lakes were correlated to the varied pollution extent from the lawns. One striking feature of the artificial lake sediments was the insufficiency of NaOH-extracted Al, which plays an important role in avoiding internal P release during anoxia. Another characteristic was the dominance of orthophosphate in the NaOH-EDTA extractants of the sediments, due to the heavy external P pollution. Phytate, considered prevalent in many soils and lake sediments, as well as polyphosphates and phosphonates which have appeared in some natural lake sediments, was not detected. The rank order of present biogenic P species was monoester-P > DNA-P > pyrophosphate > lipid-P. - Mineral fixation and biological conversion of phosphorus were investigated in artificial lake sediments in China.

  3. Analytical model for relativistic corrections to the nuclear magnetic shielding constant in atoms

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Rodolfo H. [Facultad de Ciencias Exactas, Universidad Nacional del Nordeste, Avenida Libertad 5500 (3400), Corrientes (Argentina)]. E-mail: rhromero@exa.unne.edu.ar; Gomez, Sergio S. [Facultad de Ciencias Exactas, Universidad Nacional del Nordeste, Avenida Libertad 5500 (3400), Corrientes (Argentina)

    2006-04-24

    We present a simple analytical model for calculating and rationalizing the main relativistic corrections to the nuclear magnetic shielding constant in atoms. It provides good estimates for those corrections and their trends, in reasonable agreement with accurate four-component calculations and perturbation methods. The origin of the effects in deep core atomic orbitals is manifestly shown.

  4. In vivo imaging of the rat anatomy with nuclear magnetic resonance.

    Science.gov (United States)

    Hansen, G; Crooks, L E; Davis, P; De Groot, J; Herfkens, R; Margulis, A R; Gooding, C; Kaufman, L; Hoenninger, J; Arakawa, M; McRee, R; Watts, J

    1980-09-01

    Live rats were imaged by nuclear magnetic resonance (NMR). These images demonstrated fine detail and high object contrast. Motion artifacts are not apparent in 4-minute images, and major blood vessels are demonstrated as regions of low signal intensity because of blood flow. Selective contrast enhancement is possible by varying NMR imager accumulation parameters.

  5. A New Density Operator Formalism for Describing Nuclear Magnetic Resonance Experiments

    Institute of Scientific and Technical Information of China (English)

    林东海; 吴钦义

    1994-01-01

    A density operator formalism has been proposed to describe the evolution of two-spin-1/2 systems in nuclear magnetic resonance experiments:The formalism is particularly convenient and has distinct physical meaning for describing the evolution of spin systems under the Hamiltonian containing non-commutable terms. Some examples are presented to demonstrate the new formalism.

  6. Nuclear magnetic resonance spectroscopy of living systems : Applications in comparative physiology

    NARCIS (Netherlands)

    VanDenThillart, G; VanWaarde, A

    The most attractive feature of nuclear magnetic resonance spectroscopy (MRS) is the noninvasive and nondestructive measurement of chemical compounds in intact tissues. MRS already has many applications in comparative physiology, usually based on observation of P-31, since the levels of phosphorus

  7. 19F-nuclear magnetic resonance spectroscopy as a tool to ...

    African Journals Online (AJOL)

    Purpose: 19F-Nuclear magnetic resonance spectroscopy (19F-NMR) was used to study host-guest ... least-squares curve fitting program, KINFIT, to obtain the formation constant of CD-drug complex. ..... It is interesting to note that, methylated.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-14

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

  9. Study of coals by high resolution solid state nuclear magnetic resonance

    Institute of Scientific and Technical Information of China (English)

    杨保联; 冯继文; 周建威; 李丽云; 叶朝辉

    1999-01-01

    By using high resolution solid state nuclear magnetic resonance method, six coal samples coming from four countries were investigated. Twelve structural parameters of these samples were measured and compared with those of Chinese coals. Spectral editing experiment was carried out and 15N NMR spectrum was obtained.

  10. Towards nuclear magnetic resonance micro-spectroscopy and micro-imaging.

    NARCIS (Netherlands)

    Bentum, P.J.M. van; Janssen, J.W.G.; Kentgens, A.P.M.

    2004-01-01

    The first successful experiments demonstrating Nuclear Magnetic Resonance (NMR) were a spin-off from the development of electromagnetic technology and its introduction into civilian life in the late forties. It was soon discovered that NMR spectra held chemically relevant information making it usefu

  11. Nuclear Magnetic Resonance and Elastic Wave Velocity of Chalk Saturated with Brines Containing Divalent Ions

    DEFF Research Database (Denmark)

    Katika, Konstantina; Alam, Mohammad Monzurul; Fabricius, Ida Lykke

    Nuclear magnetic resonance (NMR) has proven a good technique for measuring pore size distribution in reservoir rocks. The use of low field NMR together with sonic and electrical resistivity measurements, can contribute to illustrate the effect of adsorbing ions on chalk elasticity. NMR is useful...

  12. Nuclear magnetic resonance and sound velocity measurements of chalk saturated with magnesium rich brine

    DEFF Research Database (Denmark)

    Katika, Konstantina; Alam, Mohammad Monzurul; Fabricius, Ida Lykke

    2013-01-01

    The use of low field Nuclear Magnetic Resonance (NMR) to determine petrophysical properties of reservoirs has proved to be a good technique. Together with sonic and electrical resistivity measurements, NMR can contribute to illustrate the changes on chalk elasticity due to different pore water...

  13. A Noninvasive Method to Study Regulation of Extracellular Fluid Volume in Rats Using Nuclear Magnetic Resonance

    Science.gov (United States)

    Time-domain nuclear magnetic resonance (TD-NMR)-based measurement of body composition of rodents is an effective method to quickly and repeatedly measure proportions of fat, lean, and fluid without anesthesia. TD-NMR provides a measure of free water in a living animal, termed % f...

  14. Metabolism of perfused pig intercostal muscles evaluated by 31P-magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Pedersen, Brian Lindegaard; Arendrup, Henrik; Secher, Niels H

    2006-01-01

    This study presents a perfused preparation for evaluation of metabolism in pig intercostal muscle in vitro. Preserved vessels and nerves to an intercostal segment including two adjacent ribs allowed for tissue perfusion and electrical stimulation with measurement of contraction force, oxygen...... and 3.5 +/- 0.5 micromol min(-1) g(-1) during the two last minutes, corresponding to the drop in force. When the preparation was left unperfused, anaerobic ATP turnover averaged 0.40 +/- 0.15 micromol min(-1) g(-1) for the first 10 min. The preparation can also be applied to human intercostal muscles......, as demonstrated in one preliminary experiment. The results demonstrate a stable and functional in vitro preparation of intact perfused intercostal muscles in the pig....

  15. Non-polymeric asymmetric binary glass-formers. I. Main relaxations studied by dielectric, (2)H NMR, and (31)P NMR spectroscopy.

    Science.gov (United States)

    Pötzschner, B; Mohamed, F; Bächer, C; Wagner, E; Lichtinger, A; Minikejew, R; Kreger, K; Schmidt, H-W; Rössler, E A

    2017-04-28

    In Paper I of this series of two papers we study the main relaxations of a binary glass former made of the low-Tg component tripropyl phosphate (TPP, Tg = 134 K) and of a specially synthesized (deuterated) spirobichroman derivative (SBC, Tg = 356 K) as the non-polymeric high-Tg component for the full concentration range. A large Tg contrast of the neat components is put into effect. Dielectric spectroscopy and different techniques of (2)H nuclear magnetic resonance (NMR) as well as of (31)P NMR spectroscopy allow to selectively probe the dynamics of the components. For all concentrations, two well separated liquid-like processes are identified. The faster α2-process associated with the low-Tg component TPP shows pronounced dynamic heterogeneities reflected by quasi-logarithmic correlation functions at low TPP concentrations. The slower α1-process involves the reorientation of the high-Tg component SBC. Its correlation function is Kohlrausch-like as in neat glass formers. The corresponding time constants and consequently their glass transition temperatures Tg1 and Tg2 differ more the lower the TPP concentration is. Plasticizer and anti-plasticizer effect, respectively, is observed. At low temperatures a situation arises that the TPP molecules isotropically reorient in an arrested SBC matrix (Tg2 < T < Tg1). At T < Tg2 the liquid-like reorientation of TPP gets arrested too. We find indications that a fraction of the TPP molecule takes part in the slower α1-process of the high-Tg component. All the features known from polymer-plasticizer systems are rediscovered in this non-polymeric highly asymmetric binary mixture. In Paper II [B. Pötzschner et al., J. Chem. Phys. 146, 164504 (2017)] we study the secondary (β-) relaxations of the mixtures.

  16. Non-polymeric asymmetric binary glass-formers. I. Main relaxations studied by dielectric, 2H NMR, and 31P NMR spectroscopy

    Science.gov (United States)

    Pötzschner, B.; Mohamed, F.; Bächer, C.; Wagner, E.; Lichtinger, A.; Minikejew, R.; Kreger, K.; Schmidt, H.-W.; Rössler, E. A.

    2017-04-01

    In Paper I of this series of two papers we study the main relaxations of a binary glass former made of the low-Tg component tripropyl phosphate (TPP, Tg = 134 K) and of a specially synthesized (deuterated) spirobichroman derivative (SBC, Tg = 356 K) as the non-polymeric high-Tg component for the full concentration range. A large Tg contrast of the neat components is put into effect. Dielectric spectroscopy and different techniques of 2H nuclear magnetic resonance (NMR) as well as of 31P NMR spectroscopy allow to selectively probe the dynamics of the components. For all concentrations, two well separated liquid-like processes are identified. The faster α2-process associated with the low-Tg component TPP shows pronounced dynamic heterogeneities reflected by quasi-logarithmic correlation functions at low TPP concentrations. The slower α1-process involves the reorientation of the high-Tg component SBC. Its correlation function is Kohlrausch-like as in neat glass formers. The corresponding time constants and consequently their glass transition temperatures Tg1 and Tg2 differ more the lower the TPP concentration is. Plasticizer and anti-plasticizer effect, respectively, is observed. At low temperatures a situation arises that the TPP molecules isotropically reorient in an arrested SBC matrix (Tg2 < T < Tg1). At T < Tg2 the liquid-like reorientation of TPP gets arrested too. We find indications that a fraction of the TPP molecule takes part in the slower α1-process of the high-Tg component. All the features known from polymer-plasticizer systems are rediscovered in this non-polymeric highly asymmetric binary mixture. In Paper II [B. Pötzschner et al., J. Chem. Phys. 146, 164504 (2017)] we study the secondary (β-) relaxations of the mixtures.

  17. Effect of prior exercise in Pi/PC ratio and intracellular pH during a standardized exercise. A study on human muscle using [31P]NMR.

    Science.gov (United States)

    Laurent, D; Authier, B; Lebas, J F; Rossi, A

    1992-01-01

    Seven subjects underwent a standard localized exercise of calf muscles in order to investigate whether the metabolic exercise-induced steady-state, as revealed by the evaluation of inorganic phosphate/phosphocreatine ratio, depends on the conditioning of the muscle just prior to the exercise. The experimental protocols consisted of two separate experiments using first [31P]nuclear magnetic resonance spectroscopy and second (on 3 subjects) infrared oxyphotometry to respectively follow variation of energy metabolism and tissular deoxygenation. The exercise consisted of 240 successive plantar flexions (0.5 Hz frequency) against a high load equivalent to 80% of the maximal voluntary contraction. This exercise was accomplished before cold exercise and after warm exercise, a warming-up period bringing to approximately 50% of VO2max. The results showed that: (1) steady-state level of phosphate/phosphocreatine and intracellular acidosis was significantly lowered by warming-up; (2) cold and warm exercise steady-state of calculated adenosine diphosphate values were not significantly different; (3) cold exercise rapidly induced a high tissular deoxygenation that is not observed during warm exercise; and (4) time-constant of phosphocreatine resynthesis is lowered after warm exercise but the initial slope of time-evolution is not modified. Parallel experiments also showed that phosphate/phosphocreatine steady-state was not modified in comparison with warm exercise when the same power of exercise was reached by stepwise incrementation of the charge. From these results we postulate that a better tissue oxygenation due to a global or localized warming-up allows to reach the same mechanical performance with a lower decrease of PCr content, owing to a faster adjustment of oxidative metabolism during the transitional period.(ABSTRACT TRUNCATED AT 250 WORDS)

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

    Science.gov (United States)

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

    2013-02-15

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

  19. High resolution in vivo 31P-MRS of the liver: potential advantages in the assessment of non-alcoholic fatty liver disease.

    Science.gov (United States)

    Jeon, Min Jeong; Lee, Yunjung; Ahn, Sangdoo; Lee, Chulhyun; Kim, Ok-Hee; Oh, Byung-Chul; Yu, Ungsik; Kim, Hyeonjin

    2015-09-01

    Biopsy remains the current gold-standard for assessing non-alcoholic fatty liver disease (NAFLD). To develop a non-invasive means of assessing the disease, 31P magnetic resonance spectroscopy (31P-MRS) has been explored, but the severe spectral overlaps and low signal-to-noise-ratio in 31P-MRS spectra at clinical field strength are clearly limiting factors. To investigate potential advantages of high resolution in vivo 31P-MRS in assessing NAFLD. The study was conducted at 9.4T in control and carbon tetrachloride (CCl4)-treated rats. Rats were divided according to histopathologic findings into a control group (n = 15), a non-alcoholic steatohepatitis group (n = 17), and a cirrhosis group (n = 12). Data were presented with different reference peaks that are commonly used for peak normalization such as total phosphorous signal, phosphomonoester + phosphodiester (PME + PDE), and nucleotide triphosphate (NTP). Then, multivariate analyses were performed. In all spectra PME and PDE were well resolved into phosphoethanolamine (PE) and phosphocholine (PC), and into glycerophosphorylethanolamine (GPE) and glycerophosphorylcholine (GPC), respectively. Those MRS measures quantifiable only in highly resolved spectra had higher correlations with histology than those conventional MRS measures such as PME, PDE, and NTP. The optimized partial least-squares discriminant analysis (PLS-DA) model correctly classified 79% (22/28) of the rats in the training set and correctly predicted 69% (11/16) of the rats in the test set. PE, PC, GPE, GPC, and nicotinamide adenine dinucleotide phosphate (NADP) that can be separately quantifiable in highly resolved spectra may further improve the potential efficacy of 31P-MRS in the diagnosis of NAFLD. © The Foundation Acta Radiologica 2014.

  20. Remote detection of nuclear magnetic resonance with an anisotropic magnetoresistive sensor.

    Science.gov (United States)

    Verpillat, F; Ledbetter, M P; Xu, S; Michalak, D J; Hilty, C; Bouchard, L-S; Antonijevic, S; Budker, D; Pines, A

    2008-02-19

    We report the detection of nuclear magnetic resonance (NMR) using an anisotropic magnetoresistive (AMR) sensor. A "remote-detection" arrangement was used in which protons in flowing water were prepolarized in the field of a superconducting NMR magnet, adiabatically inverted, and subsequently detected with an AMR sensor situated downstream from the magnet and the adiabatic inverter. AMR sensing is well suited for NMR detection in microfluidic "lab-on-a-chip" applications because the sensors are small, typically on the order of 10 mum. An estimate of the sensitivity for an optimized system indicates that approximately 6 x 10(13) protons in a volume of 1,000 mum(3), prepolarized in a 10-kG magnetic field, can be detected with a signal-to-noise ratio of 3 in a 1-Hz bandwidth. This level of sensitivity is competitive with that demonstrated by microcoils in superconducting magnets and with the projected sensitivity of microfabricated atomic magnetometers.

  1. Origin of the magnetic-field dependence of the nuclear spin-lattice relaxation in iron

    CERN Document Server

    Seewald, G; Körner, H J; Borgmann, D; Dietrich, M

    2008-01-01

    The magnetic-field dependence of the nuclear spin-lattice relaxation at Ir impurities in Fe was measured for fields between 0 and 2 T parallel to the [100] direction. The reliability of the applied technique of nuclear magnetic resonance on oriented nuclei was demonstrated by measurements at different radio-frequency (rf) field strengths. The interpretation of the relaxation curves, which used transition rates to describe the excitation of the nuclear spins by a frequency-modulated rf field, was confirmed by model calculations. The magnetic-field dependence of the so-called enhancement factor for rf fields, which is closely related to the magnetic-field dependence of the spin-lattice relaxation, was also measured. For several magnetic-field-dependent relaxation mechanisms, the form and the magnitude of the field dependence were derived. Only the relaxation via eddy-current damping and Gilbert damping could explain the observed field dependence. Using reasonable values of the damping parameters, the field depe...

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

    Energy Technology Data Exchange (ETDEWEB)

    Mance, Deni; Baldus, Marc, E-mail: m.baldus@uu.nl [NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Department of Chemistry, Faculty of Science, Utrecht University, 3584 CH Utrecht (Netherlands); Gast, Peter; Huber, Martina [Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden (Netherlands); Ivanov, Konstantin L., E-mail: ivanov@tomo.nsc.ru [International Tomography Center, Siberian Branch of the Russian Academy of Science, Institutskaya 3a, Novosibirsk 630090, Russia and Novosibirsk State University, Pirogova 2, Novosibirsk 63009 (Russian Federation)

    2015-06-21

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

  3. Rose Atoll Site 31P 7/30/2004 0-1M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 0 and 1 meters along a permanent transect.

  4. Rose Atoll Site 31P 7/30/2004 22-23M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 22 and 23 meters along a permanent transect.

  5. Rose Atoll Site 31P 7/30/2004 50-51M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 50 and 51 meters along a permanent transect.

  6. Rose Atoll Site 31P 7/30/2004 4-5M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 4 and 5 meters along a permanent transect.

  7. Rose Atoll Site 31P 7/30/2004 39-40M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 39 and 40 meters along a permanent transect.

  8. Rose Atoll Site 31P 7/30/2004 44-45M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 44 and 45 meters along a permanent transect.

  9. Rose Atoll Site 31P 7/30/2004 21-22M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 21 and 22 meters along a permanent transect.

  10. Rose Atoll Site 31P 7/30/2004 45-46M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 45 and 46 meters along a permanent transect.

  11. Rose Atoll Site 31P 7/30/2004 46-47M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 46 and 47 meters along a permanent transect.

  12. Rose Atoll Site 31P 7/30/2004 32-33M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 32 and 33 meters along a permanent transect.

  13. Rose Atoll Site 31P 6/21/2005 (6)M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), at meter 6 along a permanent transect.

  14. Rose Atoll Site 31P 6/21/2005 (31)M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), at meter 31 along a permanent transect.

  15. Rose Atoll Site 31P 3/6/2006 37-38M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 37 and 38 meters along a permanent transect.

  16. Rose Atoll Site 31P 6/21/2005 (18)M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), at meter 18 along a permanent transect.

  17. Rose Atoll Site 31P 3/6/2006 27-28M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 27 and 28 meters along a permanent transect.

  18. Rose Atoll Site 31P 6/21/2005 (34)M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), at meter 34 along a permanent transect.

  19. Rose Atoll Site 31P 7/30/2004 41-42M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 41 and 42 meters along a permanent transect.

  20. Rose Atoll Site 31P 2/22/2012 47-48M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 47 and 48 meters along a permanent transect.

  1. Rose Atoll Site 31P 7/30/2004 20-21M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 20 and 21 meters along a permanent transect.

  2. Rose Atoll Site 31P 7/30/2004 40-41M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 40 and 41 meters along a permanent transect.

  3. Rose Atoll Site 31P 7/30/2004 37-38M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 37 and 38 meters along a permanent transect.

  4. Rose Atoll Site 31P 7/30/2004 8-9M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 8 and 9 meters along a permanent transect.

  5. Rose Atoll Site 31P 7/30/2004 47-48M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 47 and 48 meters along a permanent transect.

  6. Rose Atoll Site 31P 7/30/2004 2-3M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 2 and 3 meters along a permanent transect.

  7. Rose Atoll Site 31P 7/30/2004 43-44M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 43 and 44 meters along a permanent transect.

  8. Rose Atoll Site 31P 7/30/2004 5-6M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 5 and 6 meters along a permanent transect.

  9. Rose Atoll Site 31P 7/30/2004 3-4M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 3 and 4 meters along a permanent transect.

  10. Rose Atoll Site 31P 7/30/2004 27-28M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 27 and 28 meters along a permanent transect.

  11. Rose Atoll Site 31P 7/30/2004 30-31M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 30 and 31 meters along a permanent transect.

  12. Rose Atoll Site 31P 7/30/2004 13-14M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 13 and 14 meters along a permanent transect.

  13. Rose Atoll Site 31P 7/30/2004 18-19M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 18 and 19 meters along a permanent transect.

  14. Rose Atoll Site 31P 7/30/2004 6-7M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 6 and 7 meters along a permanent transect.

  15. Rose Atoll Site 31P 7/30/2004 7-8M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 7 and 8 meters along a permanent transect.

  16. Rose Atoll Site 31P 7/30/2004 48-49M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 48 and 49 meters along a permanent transect.

  17. Rose Atoll Site 31P 7/30/2004 25-26M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 25 and 26 meters along a permanent transect.

  18. Rose Atoll Site 31P 7/30/2004 15-16M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 15 and 16 meters along a permanent transect.

  19. Rose Atoll Site 31P 7/30/2004 23-24M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 23 and 24 meters along a permanent transect.

  20. Rose Atoll Site 31P 7/30/2004 9-10M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 9 and 10 meters along a permanent transect.

  1. Rose Atoll Site 31P 7/30/2004 17-18M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 17 and 18 meters along a permanent transect.

  2. Rose Atoll Site 31P 7/30/2004 12-13M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 12 and 13 meters along a permanent transect.

  3. Rose Atoll Site 31P 7/30/2004 29-30M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 29 and 30 meters along a permanent transect.

  4. Rose Atoll Site 31P 7/30/2004 28-29M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 28 and 29 meters along a permanent transect.

  5. Rose Atoll Site 31P 7/30/2004 35-36M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 35 and 36 meters along a permanent transect.

  6. Rose Atoll Site 31P 7/30/2004 1-2M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 1 and 2 meters along a permanent transect.

  7. Rose Atoll Site 31P 7/30/2004 24-25M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 24 and 25 meters along a permanent transect.

  8. Rose Atoll Site 31P 7/30/2004 38-39M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 38 and 39 meters along a permanent transect.

  9. Rose Atoll Site 31P 7/30/2004 26-27M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 26 and 27 meters along a permanent transect.

  10. Rose Atoll Site 31P 7/30/2004 31-32M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 31 and 32 meters along a permanent transect.

  11. Rose Atoll Site 31P 7/30/2004 36-37M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 36 and 37 meters along a permanent transect.

  12. Rose Atoll Site 31P 7/30/2004 49-50M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 49 and 50 meters along a permanent transect.

  13. Rose Atoll Site 31P 7/30/2004 11-12M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 11 and 12 meters along a permanent transect.

  14. Rose Atoll Site 31P 7/30/2004 42-43M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 42 and 43 meters along a permanent transect.

  15. Rose Atoll Site 31P 7/30/2004 33-34M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 33 and 34 meters along a permanent transect.

  16. Rose Atoll Site 31P 7/30/2004 16-17M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 16 and 17 meters along a permanent transect.

  17. Rose Atoll Site 31P 7/30/2004 14-15M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 14 and 15 meters along a permanent transect.

  18. Rose Atoll Site 31P 7/30/2004 34-35M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 34 and 35 meters along a permanent transect.

  19. Rose Atoll Site 31P 7/30/2004 19-20M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 19 and 20 meters along a permanent transect.

  20. Rose Atoll Site 31P 2/22/2012 16-17M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 16 and 17 meters along a permanent transect.

  1. Rose Atoll Site 31P 8/22/1999 10-11M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 10 and 11 meters along a permanent transect.

  2. Rose Atoll Site 31P 8/22/1999 8-9M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 8 and 9 meters along a permanent transect.

  3. Rose Atoll Site 31P 3/6/2006 38-39M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 38 and 39 meters along a permanent transect.

  4. Rose Atoll Site 31P 3/6/2006 24-25M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 24 and 25 meters along a permanent transect.

  5. Rose Atoll Site 31P 3/6/2006 25-26M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 25 and 26 meters along a permanent transect.

  6. Rose Atoll Site 31P 2/22/2012 28-29M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 28 and 29 meters along a permanent transect.

  7. Rose Atoll Site 31P 6/21/2005 (27)M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), at meter 27 along a permanent transect.

  8. Rose Atoll Site 31P 3/6/2006 10-11M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 10 and 11 meters along a permanent transect.

  9. Rose Atoll Site 31P 3/6/2006 18-19M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 18 and 19 meters along a permanent transect.

  10. Rose Atoll Site 31P 3/6/2006 31-32M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 31 and 32 meters along a permanent transect.

  11. Rose Atoll Site 31P 3/6/2006 23-24M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 23 and 24 meters along a permanent transect.

  12. Rose Atoll Site 31P 3/6/2006 9-10M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 9 and 10 meters along a permanent transect.

  13. Rose Atoll Site 31P 3/6/2006 47-48M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 47 and 48 meters along a permanent transect.

  14. Rose Atoll Site 31P 3/6/2006 1-2M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 1 and 2 meters along a permanent transect.

  15. Rose Atoll Site 31P 3/6/2006 33-34M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 33 and 34 meters along a permanent transect.

  16. Rose Atoll Site 31P 7/30/2004 10-11M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 10 and 11 meters along a permanent transect.

  17. Rose Atoll Site 31P 2/22/2012 23-24M

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — One-meter-square (1 meter x 1 meter) benthic substrate at Rose Atoll, site 31P (14 32.568S, 168 09.417W), between 23 and 24 meters along a permanent transect.

  18. Nuclear magnetic resonance relaxation and diffusion in the presence of internal gradients: the effect of magnetic field strength.

    Science.gov (United States)

    Mitchell, J; Chandrasekera, T C; Johns, M L; Gladden, L F; Fordham, E J

    2010-02-01

    It is known that internal magnetic field gradients in porous materials, caused by susceptibility differences at the solid-fluid interfaces, alter the observed effective Nuclear Magnetic Resonance transverse relaxation times T2,eff. The internal gradients scale with the strength of the static background magnetic field B0. Here, we acquire data at various magnitudes of B0 to observe the influence of internal gradients on T2-T2 exchange measurements; the theory discussed and observations made are applicable to any T2-T2 analysis of heterogeneous materials. At high magnetic field strengths, it is possible to observe diffusive exchange between regions of local internal gradient extrema within individual pores. Therefore, the observed exchange pathways are not associated with pore-to-pore exchange. Understanding the significance of internal gradients in transverse relaxation measurements is critical to interpreting these results. We present the example of water in porous sandstone rock and offer a guideline to determine whether an observed T2,eff relaxation time distribution reflects the pore size distribution for a given susceptibility contrast (magnetic field strength) and spin echo separation. More generally, we confirm that for porous materials T1 provides a better indication of the pore size distribution than T2,eff at high magnetic field strengths (B0>1 T), and demonstrate the data analysis necessary to validate pore size interpretations of T2,eff measurements.

  19. Nuclear Magnetic Resonance Quantum Computing Using Liquid Crystal Solvents

    CERN Document Server

    Yannoni, C S; Vandersypen, L M K; Miller, D C; Kubinec, M G; Chuang, I L; Yannoni, Costantino S.; Sherwood, Mark H.; Vandersypen, Lieven M.K.; Miller, Dolores C.; Kubinec, Mark G.; Chuang, Isaac L.

    1999-01-01

    Liquid crystals offer several advantages as solvents for molecules used for NMR quantum computing (NMRQC). The dipolar coupling between nuclear spins manifest in the NMR spectra of molecules oriented by a liquid crystal permits a significant increase in clock frequency, while short spin-lattice relaxation times permit fast recycling of algorithms, and save time in calibration and signal-enhancement experiments. Furthermore, the use of liquid crystal solvents offers scalability in the form of an expanded library of spin-bearing molecules suitable for NMRQC. These ideas are demonstrated with the successful execution of a 2-qubit Grover search using a molecule ($^{13}$C$^{1}$HCl$_3$) oriented in a liquid crystal and a clock speed eight times greater than in an isotropic solvent. Perhaps more importantly, five times as many logic operations can be executed within the coherence time using the liquid crystal solvent.

  20. Nuclear magnetic resonance on selected lithium based compounds

    Energy Technology Data Exchange (ETDEWEB)

    Rudisch, Christian

    2013-11-26

    This thesis presents the NMR measurements on the single crystals LiMnPO{sub 4} and Li{sub 0.9}FeAs. Therefore, the thesis is divided into two separated sections. The first part reports on the competitive next generation cathode material LiMnPO{sub 4} with a stable reversible capacity up to 145 mAh/g and a rather flat discharge voltage curve at 4.1 V. For the basic understanding of the material the magnetic properties have been investigated by a Li and P NMR study in the paramagnetic and antiferromagnetic phase. LiMnPO{sub 4} shows a strong anisotropy of the dipolar hyperfine coupling due to the strong local magnetic moments at the Mn site. The corresponding dipole tensor of the Li- and P-nuclei is fully determined by orientation and temperature dependent NMR experiments and compared to the calculated values from crystal structure data. Deviations of the experimentally determined values from the theoretical ones are discussed in terms of Mn disorder which could have an impact on the mobility of the Li ions. The disorder is corroborated by diffuse X-ray diffraction experiments which indicate a shift of the heavy elements in the lattice, namely the Mn atoms. Furthermore, the spin arrangement in the relative strong field of 7.0494 T in the antiferromagnetic state is understood by the NMR measurements. In order to obtain parameters of the Li ion diffusion in LiMnPO{sub 4} measurements of the spin lattice relaxation rate were performed. Due to the strong dipolar coupling between the Li-nuclei and the magnetic moments at the Mn site it is difficult to extract parameters which can characterize the diffusive behavior of the Li ions. The second section reports on the AC/DC susceptibility and NMR/NQR studies on Li deficit samples labeled as Li{sub 0.9}FeAs. LiFeAs belongs to the family of the superconducting Pnictides which are discovered in 2008 by H. Hosono et al. In recent studies the stoichiometric compound reveals triplet superconductivity below T{sub c}-18 K which

  1. Energy Moment Method Applied to Nuclear Quadrupole Splitting of Nuclear Magnetic Resonance Lines

    DEFF Research Database (Denmark)

    Frank, V

    1962-01-01

    Expressions giving the sum of the energy values, raised to the second and third power, for a nucleus interacting with a static magnetic field and a static electric field gradient are derived. Several applications of this method for obtaining the values of the components of the electric field...

  2. Investigations into the Structure and Dynamics of Chalcogenide Glasses using High-Resolution Nuclear Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Kaseman, Derrick Charles

    Chalcogenide glasses constitute an important class of materials that are sulfides, selenides or tellurides of group IV and/or V elements, namely Ge, As, P and Si with minor concentrations of other elements such as Ga, Sb, In. Because of their infrared transparency that can be tuned by changing chemistry and can be actively altered by exposure to band gap irradiation, chalcogenide glasses find use in passive and active optical devices for applications in the areas of photonics, remote sensing and memory technology. Therefore, it is important to establish predictive models of structure-property relationships for these materials for optimization of their physical properties for various applications. Structural elucidation of chalcogenide glasses is experimentally challenging and in order to make predictive structural models, structural units at both short and intermediate -range length scales must be identified and quantified. Nuclear Magnetic Resonance (NMR) spectroscopy is an element-specific structural probe that is uniquely suited for this task, but resolution and sensitivity issues have severely limited the applications of such techniques in the past. The recent development of multi-dimensional solid-state NMR techniques, such as Phase Adjusted Spinning Sidebands (PASS) and Magic Angle Turning (MAT) can potentially alleviate such issues. In this study novel two-dimensional, high-resolution 77Se and 125Te MATPASS NMR spectroscopic techniques are utilized to elucidate quantitatively the compositional evolution of the short- and intermediate- range atomic structure in three binary chalcogenide glass-forming systems, namely: GexSe100-x, AsxSe100-x , and AsxTe100-x. The spectroscopic results provide unambiguous site speciation and quantification for short- and intermediate-range structural motifs present in these glasses. In turn, for all systems, robust structural models and the corresponding structure-property relationships are successfully established as a function

  3. In vivo 31P MRS of human brain at high/ultrahigh fields: a quantitative comparison of NMR detection sensitivity and spectral resolution between 4 T and 7 T.

    Science.gov (United States)

    Qiao, Hongyan; Zhang, Xiaoliang; Zhu, Xiao-Hong; Du, Fei; Chen, Wei

    2006-12-01

    The primary goal of this study was to establish a rigorous approach for determining and comparing the NMR detection sensitivity of in vivo 31P MRS at different field strengths (B0). This was done by calculating the signal-to-noise ratio (SNR) achieved within a unit sampling time at a given field strength. In vivo 31P spectra of human occipital lobe were acquired at 4 and 7 T under similar experimental conditions. They were used to measure the improvement of the human brain 31P MRS when the field strength increases from 4 to 7 T. The relaxation times and line widths of the phosphocreatine (PCr) resonance peak and the RF coil quality factors (Q) were also measured at these two field strengths. Their relative contributions to SNR at a given field strength were analyzed and discussed. The results show that in vivo 31P sensitivity was significantly improved at 7 T as compared with 4 T. Moreover, the line-width of the PCr resonance peak showed less than a linear increase with increased B0, which leads to a significant improvement in 31P spectral resolution. These findings indicate the advantage of high-field strength to improve in vivo 31P MRS quality in both sensitivity and spectral resolution. This advantage should improve the reliability and applicability of in vivo 31P MRS in studying high-energy phosphate metabolism, phospholipid metabolism and cerebral biogenetics in the human at both normal and diseased states noninvasively. Finally, the approach used in this study for calculating in vivo 31P MRS sensitivity provides a general tool in estimating the relative NMR detection sensitivity for any nuclear spin at a given field strength.

  4. Nuclear magnetic resonance imaging of lipid in living plants.

    Science.gov (United States)

    Borisjuk, Ljudmilla; Rolletschek, Hardy; Neuberger, Thomas

    2013-10-01

    This review highlights technological developments in magnetic resonance imaging (MRI), which are creating opportunities for the three dimensional visualization and quantification of lipids in plant materials. A major feature of MRI is that it is a non-invasive platform, and thus can be used for the analysis of living organisms. An overview of the theoretical aspects of MRI is provided, followed by a description of the various analytical modes available, and an explanation of how MRI can be applied to plant samples and what it can achieve. Various lipid maps and three dimensional models of seeds and fruits are included to demonstrate the potential of MRI and to exemplify recent cutting-edge advances in the field. The importance and prospects of the imaging of lipids in living plants, as well as the integration of lipid imaging with other emerging techniques, are outlined to provide impetus for future plant lipid research. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. On the Floquet–Magnus expansion: Applications in solid-state nuclear magnetic resonance and physics

    Energy Technology Data Exchange (ETDEWEB)

    Mananga, Eugene Stephane, E-mail: emananga@gradcenter.cuny.edu [Harvard Medical School and Massachusetts General Hospital, Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging Physics, Department of Radiology, 55 Fruit Street, Boston, Massachusetts 02114 (United States); Charpentier, Thibault, E-mail: thibault.charpentier@cea.fr [Commissariat à l’Energie Atomique, IRAMIS, Service interdisciplinaire sur les systèmes moléculaires et matériaux, CEA/CNRS UMR 3299, 91191, Gif-sur-Yvette (France)

    2016-01-22

    Theoretical approaches are useful and powerful tools for more accurate and efficient spin dynamics simulation to understand experiments and devising new RF pulse sequence in nuclear magnetic resonance. Solid-state NMR is definitely a timely topic or area of research, and not many papers on the respective theories are available in the literature of nuclear magnetic resonance or physics reports. This report presents the power and the salient features of the promising theoretical approach called Floquet–Magnus expansion that is helpful to describe the time evolution of the spin system at all times in nuclear magnetic resonance. The report presents a broad view of algorithms of spin dynamics, based on promising and useful theory of Floquet–Magnus expansion. This theory provides procedures to control and describe the spin dynamics in solid-state NMR. Major applications of the Floquet–Magnus expansion are illustrated by simple solid-state NMR and physical applications such as in nuclear, atomic, molecular physics, and quantum mechanics, NMR, quantum field theory and high energy physics, electromagnetism, optics, general relativity, search of periodic orbits, and geometric control of mechanical systems. The aim of this report is to bring to the attention of the spin dynamics community, the bridge that exists between solid-state NMR and other related fields of physics and applied mathematics. This review article also discusses future potential theoretical directions in solid-state NMR.

  6. 31P MAS-NMR study of flux-grown rare-earth element orthophosphate (monazite/xenotime) solid solutions: Evidence of random cation distribution from paramagnetically shifted NMR resonances

    Energy Technology Data Exchange (ETDEWEB)

    Palke, A. C. [Stanford University; Stebbins, J. F. [Stanford University; Boatner, Lynn A [ORNL

    2013-01-01

    We present 31P magic angle spinning nuclear magnetic resonance (MAS-NMR) spectra of flux-grown solid solutions of La1-xCexPO4 ( x between 0.027 and 0.32) having the monoclinic monazite structure, and of Y1-xMxPO4 (M = Vn+, Ce3+, Nd3+, x between 0.001 and 0.014) having the tetragonal zircon structure. Paramagnetically shifted NMR resonances are observed in all samples due to the presence of paramagnetic Vn+, Ce3+, and Nd3+ in the diamagnetic LaPO4 or YPO4. As a first-order observation, the number and relative intensity of these peaks is related to the symmetry and structure of the diamagnetic host phase. The presence of paramagnetic shifts allows for increased resolution between NMR resonances for distinct atomic species which leads to the observation of low intensity peaks related to PO4 species having more than one paramagnetic neighbor two or four atomic bonds away. Through careful analysis of peak areas and comparison with predictions for simple models, it was determined that solid solutions in the systems examined here are characterized by complete disorder (random distribution) of diamagnetic La3+ or Y3+ with the paramagnetic substitutional species Ce3+ and Nd3+. The increased resolution given by the paramagnetic interactions also leads to the observation of splitting of specific resonances in the 31P NMR spectra that may be caused by local, small-scale distortions from the substitution of ions having dissimilar ionic radii.

  7. 31P magic angle spinning NMR study of flux-grown rare-earth element orthophosphate (monazite/xenotime) solid solutions: evidence of random cation distribution from paramagnetically shifted NMR resonances.

    Science.gov (United States)

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

    2013-11-04

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

  8. Using solid (13)C NMR coupled with solution (31)P NMR spectroscopy to investigate molecular species and lability of organic carbon and phosphorus from aquatic plants in Tai Lake, China.

    Science.gov (United States)

    Liu, Shasha; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Wang, Hao; He, Zhongqi; Guo, Wenjing; Song, Fanhao; Giesy, John P

    2017-01-01

    Forms and labilities of plant-derived organic matters (OMs) including carbon (C) and phosphorus (P) were fundamental for understanding their release, degradation and environmental behaviour in lake ecosystems. Thus, solid (13)C and solution (31)P nuclear magnetic resonance (NMR) spectroscopy were used to characterize biomass of six aquatic plants in Tai Lake, China. The results showed that carbohydrates (61.2% of the total C) were predominant C functional group in the solid (13)C NMR spectra of plant biomass, which may indicate high lability and bioavailability of aquatic plants-derived organic matter in lakes. There was 72.6-103.7% of the total P in aquatic plant biomass extracted by NaOH-EDTA extracts. Solution (31)P NMR analysis of these NaOH-EDTA extracts further identified several molecular species of P including orthophosphate (50.1%), orthophosphate monoesters (46.8%), DNA (1.6%) and pyrophosphate (1.4%). Orthophosphate monoesters included β-glycerophosphate (17.7%), hydrolysis products of RNA (11.7%), α-glycerophosphate (9.2%) and other unknown monoesters (2.1%). Additionally, phytate, the major form of organic P in many lake sediments, was detected in floating plant water poppy. These inorganic P (e.g. orthophosphate and pyrophosphate) and organic P (e.g. diester and its degradation products) identified in plant biomass were all labile and bioavailable P, which would play an important role in recycling of P in lakes. These results increased knowledge of chemical composition and bioavailability of OMs derived from aquatic plants in lakes.

  9. Magnetic field effect on nuclear shell structure and implications to physics of neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Kondratyev, V.N.; Maruyama, Toshiki; Chiba, Satoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1999-12-01

    The effect of the magnetic field on the shell structure of nuclei is considered by employing the shell-correction method. The shift of a phase in shell-oscillations is shown to represent the main feature of the field effect. Such a phase-change is originating from the Pauli-magnetic response associated with the relative shift of spin-up and spin-down energy levels. The neutron shell-correction energy behaves almost periodically as a function of the field strength with a slightly enhanced amplitude of the shell-oscillations at a large field. The period of the sign change is determined by the energy difference between neighbour levels. The proton shell-correction energy displays an anomalous dependence on the field. The proton orbital magnetism enhances the nuclear shell effect especially when the field influence is comparable to the spin-orbit coupling. The nuclear magic numbers are demonstrated to depend considerably on the magnetic field on the strength scale B {approx} 10{sup 16} - 10{sup 17} G relevant for neutron stars and supernovas. Such a field is found to shift significantly nuclear magics of the iron region towards smaller mass numbers. (author)

  10. Experimental quantum simulation of Avian Compass in a nuclear magnetic resonance system

    Science.gov (United States)

    Pearson, Jason; Feng, GuanRu; Zheng, Chao; Long, GuiLu

    2016-12-01

    Avian magnetoreception is the capacity for avians to sense the direction of the Earth's magnetic field. Discovered more than forty years ago, it has attracted intensive studies over the years. One promising model for describing this capacity in avians is the widely used reference-and-probe model where radical pairs within the eyes of bird combines to form singlet and triplet quantum states. The yield depends on the angle between the Earth's magnetic field and the molecules' axis, hence the relative value of yield of the singlet state or triplet state enables avians to sense the direction. Here we report the experimental demonstration of avian magnetoreception in a nuclear magnetic resonance quantum information processor. It is shown clearly from the experiment that the yield of the singlet state attains maximum when it is normal to the Earth's magnetic field, and the experimental results agree with theory very well.

  11. Nuclear magnetic resonance system with continuous flow of polarized water to obtain the traceability to static magnetic fields; Sistema de ressonancia magnetica nuclear com fluxo continuo de agua polarizada para obtencao da rastreabilidade para campos magneticos estaticos

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Ramon Valls; Nazarre, Diego Joriro, E-mail: ramon@ipt.br [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

    2013-07-01

    We have developed a system to obtain the traceability of field or magnetic induction intensity in the range of 2 μT up to 2 T, even in the presence of magnetic field gradients or noisy environments. The system is based on a nuclear magnetic resonance magnetometer, built in streaming water. The calibration procedure of a coil for magnetic field generation is described, as well as the results obtained and the estimated uncertainty (author)

  12. Development of nuclear magnetic and quadrupole resonance spectroscopy under 10 GPa class pressure

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, R; Uchida, Y; Hirayama, K; Yamazaki, T; Fukazawa, H; Kohori, Y [Department of Physics, Graduate School of Science, Chiba University, Chiba 263-8522 (Japan); Takeshita, N, E-mail: hideto@nmr.s.chiba-u.ac.j [JST, TRIP, Chiyoda-ku, Tokyo 102-0075 (Japan)

    2010-03-01

    The high pressure nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) are conventionally performed up to 3 GPa using piston cylinder cell. However, the NMR/NQR measurements beyond this pressure range are scarcely performed owing to the technical difficulty. Recently, we developed new high pressure NMR/NQR technique using cubic anvil apparatus in which highly hydrostatic pressure was obtained. Using the new method, the {sup 63}Cu-NQR signal of Cu{sub 2}O was observed up to 7.2GPa with high sensitivity. The use of MgO gasket in mini-cubic anvil apparatus was examined for enlarging pressure range.

  13. Four-component relativistic theory for nuclear magnetic shielding: magnetically balanced gauge-including atomic orbitals.

    Science.gov (United States)

    Cheng, Lan; Xiao, Yunlong; Liu, Wenjian

    2009-12-28

    It is recognized only recently that the incorporation of the magnetic balance condition is absolutely essential for four-component relativistic theories of magnetic properties. Another important issue to be handled is the so-called gauge problem in calculations of, e.g., molecular magnetic shielding tensors with finite bases. It is shown here that the magnetic balance can be adapted to distributed gauge origins, leading to, e.g., magnetically balanced gauge-including atomic orbitals (MB-GIAOs) in which each magnetically balanced atomic orbital has its own local gauge origin placed on its center. Such a MB-GIAO scheme can be combined with any level of theory for electron correlation. The first implementation is done here at the coupled-perturbed Dirac-Kohn-Sham level. The calculated molecular magnetic shielding tensors are not only independent of the choice of gauge origin but also converge rapidly to the basis set limit. Close inspections reveal that (zeroth order) negative energy states are only important for the expansion of first order electronic core orbitals. Their contributions to the paramagnetism are therefore transferable from atoms to molecule and are essentially canceled out for chemical shifts. This allows for simplifications of the coupled-perturbed equations.

  14. Residual Dipolar Couplings in Zero-to-Ultra-Low-Field Nuclear Magnetic Resonance

    CERN Document Server

    Blanchard, John W; King, Jonathan P; Ledbetter, Micah P; Levine, Emma H; Bajaj, Vikram S; Budker, Dmitry; Pines, Alexander

    2015-01-01

    Zero-to-ultra-low-field nuclear magnetic resonance (ZULF-NMR) provides a new regime for the measurement of nuclear spin-spin interactions free from effects of large magnetic fields, such as truncation of terms that do not commute with the Zeeman Hamiltonian. One such interaction, the magnetic dipole-dipole coupling, is a valuable source of spatial information in NMR, though many terms are unobservable in high-field NMR, and the interaction averages to zero under isotropic molecular tumbling. Under partial orientational ordering, this information is retained in the form of so-called residual dipolar couplings. We report zero-to-ultra-low-field NMR measurements of residual dipolar couplings in acetonitrile-2-$^{13}$C aligned in stretched polyvinyl acetate gels. This represents the first investigation of dipolar couplings as a perturbation on the indirect spin-spin $J$-coupling in the absence of an applied magnetic field. As a consequence of working at zero magnetic field, we observe terms of the dipole-dipole c...

  15. Generation of low-frequency electric and magnetic fields during large- scale chemical and nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Adushkin, V.V. [Academy of Sciences, Moscow (Russian Federation). Inst. for Dynamics of the Geospheres; Dubinya, V.A.; Karaseva, V.A.; Soloviev, S.P.; Surkov, V.V. [Lawrence Livermore National Lab., CA (United States)

    1995-06-01

    We discuss the main parameters of the electric field in the surface layer of the atmosphere and the results of the investigations of the natural electric field variations. Experimental investigations of the electromagnetic field for explosions in air are presented. Electromagnetic signals generated by underground nuclear and chemical explosions are discussed and explosions for 1976--1991 are listed. Long term anomalies of the earth`s electromagnetic field in the vicinity of underground explosions were also investigated. Study of the phenomenon of the irreversible shock magnetization showed that in the zone nearest to the explosion the quasistatic magnetic field decreases in inverse proportion to the distance.

  16. A method for mechanical generation of radio frequency fields in nuclear magnetic resonance force microscopy

    CERN Document Server

    Wagenaar, J J T; Donkersloot, R J; Marsman, F; de Wit, M; Bossoni, L; Oosterkamp, T H

    2016-01-01

    We present an innovative method for magnetic resonance force microscopy (MRFM) with ultra-low dissipation, by using the higher modes of the mechanical detector as radio frequency (rf) source. This method allows MRFM on samples without the need to be close to an rf source. Furthermore, since rf sources require currents that give dissipation, our method enables nuclear magnetic resonance experiments at ultra-low temperatures. Removing the need for an on-chip rf source is an important step towards a MRFM which can be widely used in condensed matter physics.

  17. Electromagnetic properties of inner double walled carbon nanotubes investigated by nuclear magnetic resonance

    KAUST Repository

    Bouhrara, M.

    2013-01-01

    The nuclear magnetic resonance (NMR) analytical technique was used to investigate the double walled carbon nanotubes (DWNTs) electromagnetic properties of inner walls. The local magnetic and electronic properties of inner nanotubes in DWNTs were analyzed using 25% 13C enriched C 60 by which the effect of dipolar coupling could be minimized. The diamagnetic shielding was determined due to the ring currents on outer nanotubes in DWNTs. The NMR chemical shift anisotropy (CSA) spectra and spin-lattice relaxation studies reveal the metallic properties of the inner nanotubes with a signature of the spin-gap opening below 70 K.

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

    Science.gov (United States)

    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.

  19. Magnetic Lenz lenses increase the limit-of-detection in nuclear magnetic resonance

    CERN Document Server

    Spengler, Nils; Meissner, Markus V; Wallrabe, Ulrike; Korvink, Jan G

    2016-01-01

    A high NMR detection sensitivity is indispensable when dealing with mass and volume-limited samples, or whenever a high spatial resolution is required. The use of miniaturised RF coils is a proven way to increase sensitivity, but may be impractical and is not applicable to every experimental situation. We present the use of magnetic lenses, denoted as Lenz lenses due to their working principle, to focus the magnetic flux of a macroscopic RF coil into a smaller volume and thereby locally enhance the sensitivity of the NMR experiment - at the expense of the total sensitive volume. Besides focusing, such lenses facilitate re-guiding or re-shaping of magnetic fields much like optical lenses do with light beams. For the first time we experimentally demonstrate the use of Lenz lenses in magnetic resonance and provide a compact mathematical description of the working principle. Through simulations we show that optimal arrangements can be found.

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

    Science.gov (United States)

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

    2016-11-01

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

  1. Analysis of antimycin A by reversed-phase liquid chromatography/nuclear magnetic-resonance spectrometry

    Science.gov (United States)

    Ha, Steven T.K.; Wilkins, Charles L.; Abidi, Sharon L.

    1989-01-01

    A mixture of closely related streptomyces fermentation products, antimycin A, Is separated, and the components are identified by using reversed-phase high-performance liquid chromatography with directly linked 400-MHz proton nuclear magnetic resonance detection. Analyses of mixtures of three amino acids, alanine, glycine, and valine, are used to determine optimal measurement conditions. Sensitivity increases of as much as a factor of 3 are achieved, at the expense of some loss in chromatographic resolution, by use of an 80-μL NMR cell, Instead of a smaller 14-μL cell. Analysis of the antimycin A mixture, using the optimal analytical high performance liquid chromatography/nuclear magnetic resonance conditions, reveals it to consist of at least 10 closely related components.

  2. Negotiated identities of chemical instrumentation: the case of nuclear magnetic resonance spectroscopy, 1956-1969.

    Science.gov (United States)

    Roberts, Jody A

    2003-05-01

    What is an NMR spectrometer? Beginning with this seemingly simple question, I will explore the development of nuclear magnetic resonance spectroscopy between the years 1956 and 1969 from two vantage points: the organic chemists who used the new instrument, and Varian Associates-the makers of the first NMR spectrometers-. Through an examination of the articles and advertisements published in the Journal of Organic Chemistry, I will draw two conclusions. First, organic chemists and Varian Associates (along with other actors) are co-responsible for the development of nuclear magnetic resonance spectroscopy (i.e., NMR spectroscopy was not created by a single actor). Second, by changing the way NMR spectrometers are used, organic chemists attempted to change to the identity of the instrument. Similarly, when Varian Associates advertised their NMR spectrometers in a different way, they, too, attempted to change the identity of the instrument.

  3. Simulation of general three-body interactions in a nuclear magnetic resonance ensemble quantum computer

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Three-body interaction plays an important role in many-body physics,and quantum computer is efficient in simulating many-body interactions. We have experimentally demonstrated the general three-body interactions in a three-qubit nuclear magnetic resonance ensemble quantum computer. Using a nuclear magnetic resonance computer we implemented general forms of three-body interactions including σ 1x σ z2 σ x3 and σ 1x σ z2 σ y3 . The results show good agreement between theory and experiment. We have also given a concise and practical formula for a general n-body interaction in terms of one-and two-body interactions.

  4. Use of Nuclear Spin Noise Spectroscopy to Monitor Slow Magnetization Buildup at Millikelvin Temperatures

    Science.gov (United States)

    Pöschko, Maria Theresia; Peat, David; Owers‐Bradley, John

    2016-01-01

    Abstract At ultralow temperatures, longitudinal nuclear magnetic relaxation times become exceedingly long and spectral lines are very broad. These facts pose particular challenges for the measurement of NMR spectra and spin relaxation phenomena. Nuclear spin noise spectroscopy is used to monitor proton spin polarization buildup to thermal equilibrium of a mixture of glycerol, water, and copper oxide nanoparticles at 17.5 mK in a static magnetic field of 2.5 T. Relaxation times determined in such a way are essentially free from perturbations caused by excitation radiofrequency pulses, radiation damping, and insufficient excitation bandwidth. The experimental spin‐lattice relaxation times determined on resonance by saturation recovery with spin noise detection are consistently longer than those determined by using pulse excitation. These longer values are in better accordance with the expected field dependence trend than those obtained by on‐resonance experiments with pulsed excitation. PMID:27305629

  5. Muscle metabolism of professional athletes using {sup 31}P-spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Maeurer, J.; Soellner, O.; Ehrenstein, T.; Knollmann, F.; Vogl, T.J.; Felix, R. [Humboldt-Universitaet, Berlin (Germany). Strahlenklinik und Poliklinik; Konstanczak, P. [Medizinische Univ. Luebeck (Germany). Inst. fuer Radiologie; Wolff, R. [Humboldt-Universitaet Berlin (Germany). Dept. of Sports Medicine

    1999-01-01

    Purpose: The aim of the study was to examine muscle metabolism in athletes by {sup 31}P-spectroscopy (MRS) and to evaluate to what degree the respective resonance spectrum correlates with the kind of muscle exercise. Material and Methods: Twelve runners and 12 young ice skaters were studied by {sup 31}P-spectroscopy of the gastrocnemic medialis muscle and the vastus medialis muscle using a surface coil at 1.5 T. Results: Sprinters displayed a higher phosphocreatinine/inorganic phosphate (PCr/Pi) and PCr/{beta}-ATP ratios than marathon runners. The respective parameters for middle distance runners were in between. Ice skaters could prospectively be divided into sprint- and long-distance runners by our results which correlated with the athletes` training performance. Conclusion: {sup 31}P-spectroscopy can evaluate the distribution of muscle fiber types. Thus, the athlete`s potential for sprint- or long-distance running can be determined. Additional studies will have to demonstrate to what extent training may change muscle fiber distribution. (orig.)

  6. Transition-Selective Pulses in Zero-Field Nuclear Magnetic Resonance.

    Science.gov (United States)

    Sjolander, Tobias F; Tayler, Michael C D; King, Jonathan P; Budker, Dmitry; Pines, Alexander

    2016-06-30

    We use low-amplitude, ultralow frequency pulses to drive nuclear spin transitions in zero and ultralow magnetic fields. In analogy to high-field NMR, a range of sophisticated experiments becomes available as these allow narrow-band excitation. As a first demonstration, pulses with excitation bandwidths 0.5-5 Hz are used for population redistribution, selective excitation, and coherence filtration. These methods are helpful when interpreting zero- and ultralow-field NMR spectra that contain a large number of transitions.

  7. Thermal Transition of Ribonuclease A Observed Using Proton Nuclear Magnetic Resonance

    Institute of Scientific and Technical Information of China (English)

    闫永彬; 罗雪春; 周海梦; 张日清

    2001-01-01

    The thermal transition of bovine pancreatic ribonuclease A (RNase A) was investigated using proton nuclear magnetic resonance (NMR). Significant resonance overlap in the large native protein limits accurate assignments in the 1H NMR spectrum. This study proposes extending the investigation of large proteins by dynamic analysis. Comparison of the traditional method and the correlation coefficient method suggests successful application of spectrum image analysis in dynamic protein studies by NMR.

  8. Simulation of the four-body interaction in a nuclear magnetic resonance quantum information processor

    Institute of Scientific and Technical Information of China (English)

    LIU WenZhang; ZHANG JingFu; LONG GuiLu

    2009-01-01

    The four-body interaction plays an important role in many-body systems,and it can exhibit interesting phase transition behaviors.In this letter,we report the experimental demonstration of a four-body interaction in a four-qubit nuclear magnetic resonance quantum information processor.The strongly modulating pulse is used to implement spin selective excitation.The results show a good agreement between theory and experiment.

  9. Solid state nuclear magnetic resonance studies of prion peptides and proteins

    Energy Technology Data Exchange (ETDEWEB)

    Heller, Jonathan [Univ. of California, Berkeley, CA (United States)

    1997-08-01

    High-resolution structural studies using x-ray diffraction and solution nuclear magnetic resonance (NMR) are not feasible for proteins of low volubility and high tendency to aggregate. Solid state NMR (SSNMR) is in principle capable of providing structural information in such systems, however to do this efficiently and accurately, further SSNMR tools must be developed This dissertation describes the development of three new methods and their application to a biological system of interest, the priori protein (PrP).

  10. Nuclear magnetic resonance study of changes induced by the energy of ultrasonic field in the lungs.

    Science.gov (United States)

    Gaită, A; Andru-Vangheli, D; Nagy, I; Coman, M; Covlescu, H

    156 laboratory mice were exposed to ultrasonic (US) waves under 12 different conditions. After exposure to ultrasounds, the left lung of each animal was studied morphopathologically and then analysed by nuclear magnetic resonance (NMR) spectroscopy. The study emphasized the possibility of hemorrhagical lesions in the lung through US and the fact that both measurement techniques (for T1 and T2) are alike in sensitivity. The effect on the lung is depending on the intensity and time of exposure to US.

  11. Self-energy Effects on Nuclear Magnetic Resonance Parameters within Quantum Electrodynamics Perturbation Theory

    Directory of Open Access Journals (Sweden)

    Gustavo A. Aucar

    2002-08-01

    Full Text Available Abstract: A theory for the calculation of self-energy corrections to the nuclear magnetic parameters is given in this paper. It is based on the S-matrix formulation of bound-state quantum electrodynamics (QED. Explicit expressions for the various terms of the S-matrix are given. The interpretation of the self-energy, one- and two-vertex terms and some perspective for possible future developments are discussed.

  12. Glass transition temperatures of epoxy resins by pulsed nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rutenberg, A.C.; Dorsey, G.F.; Peck, C.G.

    1976-04-21

    Pulsed nuclear magnetic resonance spectroscopy has been used to measure the glass transition temperatures of cured epoxy resins. These measurements make it possible to monitor the cure and determine the glass transition temperature as a function of the curing conditions and the concentration of the components. Knowledge of the glass transition temperature of the cured epoxies allows screening of them for a number of uses, including adhesives and coatings operations.

  13. Simulating decoherence behavior of a system in entangled state using nuclear magnetic resonance

    CERN Document Server

    Zhang, J; Shan, L; Deng, Z; Zhang, Jingfu; Lu, Zhiheng; Shan, Lu; Deng, Zhiwei

    2002-01-01

    By choosing H nucleus in Carbon-13 labelled trichloroethylene as one qubit environment, and two C nuclei as a two-qubit system, we have simulated quantum decoherence when the system lies in an entangled state using nuclear magnetic resonance (NMR). Decoupling technique is used to trace over the environment degrees of freedom. Experimental results show agreements with the theoretical predictions. Our experiment scheme can be generalized to the case that environment is composed of multiple qubits.

  14. NMR absolute shielding scale and nuclear magnetic dipole moment of (207)Pb.

    Science.gov (United States)

    Adrjan, Bożena; Makulski, Włodzimierz; Jackowski, Karol; Demissie, Taye B; Ruud, Kenneth; Antušek, Andrej; Jaszuński, Michał

    2016-06-28

    An absolute shielding scale is proposed for (207)Pb nuclear magnetic resonance (NMR) spectroscopy. It is based on ab initio calculations performed on an isolated tetramethyllead Pb(CH3)4 molecule and the assignment of the experimental resonance frequency from the gas-phase NMR spectra of Pb(CH3)4, extrapolated to zero density of the buffer gas to obtain the result for an isolated molecule. The computed (207)Pb shielding constant is 10 790 ppm for the isolated molecule, leading to a shielding of 10799.7 ppm for liquid Pb(CH3)4 which is the accepted reference standard for (207)Pb NMR spectra. The new experimental and theoretical data are used to determine μ((207)Pb), the nuclear magnetic dipole moment of (207)Pb, by applying the standard relationship between NMR frequencies, shielding constants and nuclear moments of two nuclei in the same external magnetic field. Using the gas-phase (207)Pb and (reference) proton results and the theoretical value of the Pb shielding in Pb(CH3)4, we find μ((207)Pb) = 0.59064 μN. The analysis of new experimental and theoretical data obtained for the Pb(2+) ion in water solutions provides similar values of μ((207)Pb), in the range of 0.59000-0.59131 μN.

  15. Nuclear magnetic shielding constants of liquid water: Insights from hybrid quantum mechanics/molecular mechanics models

    Science.gov (United States)

    Kongsted, Jacob; Nielsen, Christian B.; Mikkelsen, Kurt V.; Christiansen, Ove; Ruud, Kenneth

    2007-01-01

    We present a gauge-origin independent method for the calculation of nuclear magnetic shielding tensors of molecules in a structured and polarizable environment. The method is based on a combination of density functional theory (DFT) or Hartree-Fock wave functions with molecular mechanics. The method is unique in the sense that it includes three important properties that need to be fulfilled in accurate calculations of nuclear magnetic shielding constants: (i) the model includes electron correlation effects, (ii) the model uses gauge-including atomic orbitals to give gauge-origin independent results, and (iii) the effect of the environment is treated self-consistently using a discrete reaction-field methodology. The authors present sample calculations of the isotropic nuclear magnetic shielding constants of liquid water based on a large number of solute-solvent configurations derived from molecular dynamics simulations employing potentials which treat solvent polarization either explicitly or implicitly. For both the O17 and H1 isotropic shielding constants the best predicted results compare fairly well with the experimental data, i.e., they reproduce the experimental solvent shifts to within 4ppm for the O17 shielding and 1ppm for the H1 shielding.

  16. Nuclear magnetic shielding constants of liquid water: insights from hybrid quantum mechanics/molecular mechanics models.

    Science.gov (United States)

    Kongsted, Jacob; Nielsen, Christian B; Mikkelsen, Kurt V; Christiansen, Ove; Ruud, Kenneth

    2007-01-21

    We present a gauge-origin independent method for the calculation of nuclear magnetic shielding tensors of molecules in a structured and polarizable environment. The method is based on a combination of density functional theory (DFT) or Hartree-Fock wave functions with molecular mechanics. The method is unique in the sense that it includes three important properties that need to be fulfilled in accurate calculations of nuclear magnetic shielding constants: (i) the model includes electron correlation effects, (ii) the model uses gauge-including atomic orbitals to give gauge-origin independent results, and (iii) the effect of the environment is treated self-consistently using a discrete reaction-field methodology. The authors present sample calculations of the isotropic nuclear magnetic shielding constants of liquid water based on a large number of solute-solvent configurations derived from molecular dynamics simulations employing potentials which treat solvent polarization either explicitly or implicitly. For both the (17)O and (1)H isotropic shielding constants the best predicted results compare fairly well with the experimental data, i.e., they reproduce the experimental solvent shifts to within 4 ppm for the (17)O shielding and 1 ppm for the (1)H shielding.

  17. (83)Kr nuclear magnetic moment in terms of that of (3)He.

    Science.gov (United States)

    Makulski, Włodzimierz

    2014-08-01

    High resolution NMR spectroscopy was applied to precisely determine the (83)Kr nuclear magnetic dipole moment on the basis of new results available for nuclear magnetic shielding in krypton and helium-3 atoms. Small amounts of (3)He as the solutes and (83)Kr as the buffer gas were observed in (3)He and (83)Kr NMR spectra at the constant external field, B0 = 11.7578 T. In each case, the resonance frequencies (ν(He) and ν(Kr)) were linearly dependent on the density of gaseous solvent. The extrapolation of experimental points to the zero density of gaseous krypton allowed for the evaluation of both resonance frequencies free from intermolecular interactions. By combining these measurements with the recommended (83)Kr chemical shielding value, the nuclear magnetic moment could be determined with much better precision than ever before, μ((83)Kr) = -0.9707297(32)μN, with the improvement due to the greater accuracy of the spectral data.

  18. Bohr-Weisskopf effect influence of the distributed nuclear magnetization on hfs

    CERN Document Server

    Stroke, Hinko Henry; Pinard, J

    2000-01-01

    Nuclear magnetic moments provide a sensitive test of nuclear wave functions, in particular those of neutrons, which are not readily obtainable from other nuclear data. These are taking added importance by recent proposals to study parity non-conservation (PNC) effects in alkali atoms in isotopic series. By taking ratios of the PNC effects in pairs of isotopes, uncertainties in the atomic wave functions are largely cancelled out at the cost of knowledge of the change in the neutron wave function, the Bohr-Weisskopf effect (1950) in the hyperfine structure interaction of atoms measures the influence of the spatial distribution of the nuclear magnetization, and thereby provides an additional constraint on the determination of the neutron wave function. The added great importance of B-W in the determination of QED effects from the hfs in hydrogen-like ions of heavy elements, as measured recently at GSI, is noted, the B-W experiments require precision measurements of the hfs interactions and, independently, of the...

  19. Nuclear magnetic biosignatures in the carbonaceous matter of ancient cherts: comparison with carbonaceous meteorites.

    Science.gov (United States)

    Gourier, Didier; Delpoux, Olivier; Binet, Laurent; Vezin, Hervé

    2013-10-01

    The search for organic biosignatures is motivated by the hope of understanding the conditions of emergence of life on Earth and the perspective of finding traces of extinct life in martian sediments. Paramagnetic radicals, which exist naturally in amorphous carbonaceous matter fossilized in Precambrian cherts, were used as local structural probes and studied by electron paramagnetic resonance (EPR) spectroscopy. The nuclear magnetic resonance transitions of elements inside and around these radicals were detected by monitoring the nuclear modulations of electron spin echo in pulsed EPR. We found that the carbonaceous matter of fossilized microorganisms with age up to 3.5 billion years gives specific nuclear magnetic signatures of hydrogen (¹H), carbon (¹³C), and phosphorus (³¹P) nuclei. We observed that these potential biosignatures of extinct life are found neither in the carbonaceous matter of carbonaceous meteorites (4.56 billion years), the most ancient objects of the Solar System, nor in any carbonaceous matter resulting from carbonization of organic and bioorganic precursors. These results indicate that these nuclear signatures are sensitive to thermal episodes and can be used for Archean cherts with metamorphism not higher than the greenschist facies.

  20. Fabrication and Magnetic Properties of Co-Doped TiO2 Powders Studied by Nuclear Magnetic Resonance

    Institute of Scientific and Technical Information of China (English)

    GE Shi-Hui; WANG Xin-Wei; KOU Xiao-Ming; ZHOU Xue-Yun; XI Li; ZUO Ya-Lu; YANG Xiao-Lin; ZHAO Yu-Xuan

    2005-01-01

    @@ Co0.04 Ti0.96 O2 powders are fabricated by sol-gel method. The structure and magnetic properties are investigated under different annealing conditions systematically with emphasis on the influence of oxygen pressure. Pure anatase structure was acquired for all the samples annealed at 450 ℃ for one hour. The samples annealed in air exhibit evident room-temperature ferromagnetism (RTFM) with a small magnetic moment of 0.029μB per Co atom and coercivity Hc of 26 Oe, while the samples annealed in vacuum have strong RTFM with a larger magnetic moment of 1.18 μB per Co atom and Hc of 430 Oe. The zero-field spin echo nuclear magnetic resonance spectrum of 59 Co is obtained to prove the existence of Co clusters in the latter samples, implying that the Co clusters are responsible for the strong RTFM in the samples annealed in vacuum. No Co cluster could be observed using both XPS and NMR techniques in the samples annealed in air, implying that the RTFM found in these samples is intrinsic.

  1. Advances in high-resolution nuclear magnetic resonance methods in inhomogeneous magnetic fields using intermolecular multiple quantum coherences

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Strong and extremely homogeneous static magnetic field is usually required for high-resolution nu-clear magnetic resonance (NMR). However, in the cases of in vivo and so on, the magnetic field inho-mogeneity owing to magnetic susceptibility variation in samples is unavoidable and hard to eliminate by conventional methods such as shimming. Recently, intermolecular multiple quantum coherences (iMQCs) have been employed to eliminate inhomogeneous broadening and obtain high-resolution NMR spectra, especially for in vivo samples. Compared to other high-resolution NMR methods, iMQC method exhibits its unique feature and advantage. It simultaneously holds information of chemical shifts, multiplet structures, coupling constants, and relative peak areas. All the information is often used to analyze and characterize molecular structures in conventional one-dimensional NMR spec-troscopy. In this work, recent technical developments including our results in this field are summarized; the high-resolution mechanism is analyzed and comparison with other methods based on interactions between spins is made; comments on the current situation and outlook on the research directions are also made.

  2. Correction of environmental magnetic fields for the acquisition of Nuclear magnetic relaxation dispersion profiles below Earth's field

    Science.gov (United States)

    Zampetoulas, Vasileios; Lurie, David J.; Broche, Lionel M.

    2017-09-01

    T1 relaxation times can be measured at a range of magnetic field strengths by Fast Field-Cycling (FFC) NMR relaxometry to provide T1-dispersion curves. These are valuable tools for the investigation of material properties as they provide information about molecular dynamics non-invasively. However, accessing information at fields below 230 μT (10 kHz proton Larmor frequency) requires careful correction of unwanted environmental magnetic fields. In this work a novel method is proposed that compensates for the environmental fields on a FFC-NMR relaxometer and extends the acquisition of Nuclear Magnetic Relaxation Dispersion profiles to 2.3 μT (extremely low field region), with direct application in the study of slow molecular motions. Our method is an improvement of an existing technique, reported by Anoardo and Ferrante in 2003, which exploits the non-adiabatic behaviour of the magnetisation in rapidly-varying magnetic fields and makes use of the oscillation of the signal amplitude to estimate the field strength. This increases the accuracy in measuring the environmental fields and allows predicting the optimal correction values by applying simple equations to fit the data acquired. Validation of the method is performed by comparisons with well-known dispersion curves obtained from polymers and benzene.

  3. Nonaqueous magnetic nanoparticle suspensions with controlled particle size and nuclear magnetic resonance properties.

    Science.gov (United States)

    Meledandri, Carla J; Stolarczyk, Jacek K; Ghosh, Swapankumar; Brougham, Dermot F

    2008-12-16

    We report the preparation of monodisperse maghemite (gamma-Fe2O3) nanoparticle suspensions in heptane, by thermal decomposition of iron(III) acetylacetonate in the presence of oleic acid and oleylamine surfactants. By varying the surfactant/Fe precursor mole ratio during synthesis, control was exerted both over the nanocrystal core size, in the range from 3 to 6 nm, and over the magnetic properties of the resulting nanoparticle dispersions. We report field-cycling 1H NMR relaxation analysis of the superparamagnetic relaxation rate enhancement of nonaqueous suspensions for the first time. This approach permits measurement of the relaxivity and provides information on the saturation magnetization and magnetic anisotropy energy of the suspended particles. The saturation magnetization was found to be in the expected range for maghemite particles of this size. The anisotropy energy was found to increase significantly with decreasing particle size, which we attribute to increased shape anisotropy. This study can be used as a guide for the synthesis of maghemite nanoparticles with selected magnetic properties for a given application.

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

    Science.gov (United States)

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

    2014-06-01

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

  5. Application of nuclear magnetic resonance in osteoporosis evaluation; Aplicacoes de ressonancia magnetica nuclear na avaliacao de osteoporose

    Energy Technology Data Exchange (ETDEWEB)

    Giannoni, Ricardo A., E-mail: giannoni@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Montrazi, Elton T.; Bonagamba, Tito J., E-mail: elton.montrazi@gmail.com, E-mail: tito@ifsc.usp.br [Universidade de Sao Paulo (IFSC/USP), Sao Carlos, SP (Brazil). Inst. de Fisica; Cesar, Reinaldo, E-mail: reinaldofisica@gmail.com [Universidade de Sao Paulo (EESC/USP), Sao Carlos, SP (Brazil). Escola de Engenharia

    2013-07-01

    In this work, initially ceramic samples of known porosity were used. These ceramic samples were saturated with water. The nuclear magnetic resonance signal due to relaxation processes that the hydrogen nucleus water contained in the pores of this ceramic material was measured. Then these samples were subjected to a process of drying and measures successively. As the water contained in pores greater evaporates the intensity of signal decreases and shows the sign because of the smaller pores. The analysis of this drying process gives a qualitative assessment of the pore size of the material. In a second step, bones of animals of unknown porosity underwent the same methodology for evaluating osteoporosis. Also a sample of human vertebra in a unique manner, with the same purpose was measured. Combined with other techniques is a quantitative evaluation of the possible porosity.

  6. Enhanced affinity of ketotifen toward tamarind seed polysaccharide in comparison with hydroxyethylcellulose and hyaluronic acid: a nuclear magnetic resonance investigation.

    Science.gov (United States)

    Uccello-Barretta, Gloria; Nazzi, Samuele; Balzano, Federica; Di Colo, Giacomo; Zambito, Ylenia; Zaino, Chiara; Sansò, Marco; Salvadori, Eleonora; Benvenuti, Marco

    2008-08-01

    Nuclear magnetic resonance (NMR) spectroscopy demonstrated that, in aqueous solution, ketotifen fumarate bound more strongly to tamarind seed polysaccharide (TSP) than to hydroxyethylcellulose or hyaluronic acid. Results were confirmed by dynamic dialysis technique.

  7. Low-field nuclear magnetic resonance for the in vivo study of water content in trees

    Energy Technology Data Exchange (ETDEWEB)

    Yoder, Jacob, E-mail: jlyoder@lanl.gov [Inorganic, Isotope and Actinide Chemistry, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Malone, Michael W.; Espy, Michelle A. [Applied Modern Physics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Sevanto, Sanna [Earth Systems Observations, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-09-15

    Nuclear magnetic resonance (NMR) and magnetic resonance imaging have long been used to study water content in plants. Approaches have been primarily based on systems using large magnetic fields (∼1 T) to obtain NMR signals with good signal-to-noise. This is because the NMR signal scales approximately with the magnetic field strength squared. However, there are also limits to this approach in terms of realistic physiological configuration or those imposed by the size and cost of the magnet. Here we have taken a different approach – keeping the magnetic field low to produce a very light and inexpensive system, suitable for bulk water measurements on trees less than 5 cm in diameter, which could easily be duplicated to measure on many trees or from multiple parts of the same tree. Using this system we have shown sensitivity to water content in trees and their cuttings and observed a diurnal signal variation in tree water content in a greenhouse. We also demonstrate that, with calibration and modeling of the thermal polarization, the system is reliable under significant temperature variation.

  8. Using microcontact printing to fabricate microcoils on capillaries for high resolution proton nuclear magnetic resonance on nanoliter volumes

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.A.; Jackman, R.J.; Whitesides, G.M. [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States); Olson, D.L.; Sweedler, J.V. [Beckman Institute and Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    1997-05-01

    This letter describes a method for producing conducting microcoils for high resolution proton nuclear magnetic resonance ({sup 1}H-NMR) spectroscopy on nanoliter volumes. This technique uses microcontact printing and electroplating to form coils on microcapillaries. Nuclear magnetic resonance spectra collected using these microcoils, have linewidths less than 1 Hz for model compounds and a limit of detection (signal-to-noise ratio=3) for ethylbenzene of 2.6 nmol in 13 min. {copyright} {ital 1997 American Institute of Physics.}

  9. Superconducting quantum interference device microsusceptometer balanced over a wide bandwidth for nuclear magnetic resonance applications

    Energy Technology Data Exchange (ETDEWEB)

    Vinante, A., E-mail: anvinante@fbk.eu; Falferi, P. [Istituto di Fotonica e Nanotecnologie, CNR - Fondazione Bruno Kessler, I-38123 Povo, Trento (Italy); Mezzena, R. [Dipartimento di Fisica, Università di Trento, I-38123 Povo, Trento (Italy)

    2014-10-15

    Superconducting Quantum Interference Device (SQUID) microsusceptometers have been widely used to study magnetic properties of materials at microscale. As intrinsically balanced devices, they could also be exploited for direct SQUID-detection of nuclear magnetic resonance (NMR) from micron sized samples, or for SQUID readout of mechanically detected NMR from submicron sized samples. Here, we demonstrate a double balancing technique that enables achievement of very low residual imbalance of a SQUID microsusceptometer over a wide bandwidth. In particular, we can generate ac magnetic fields within the SQUID loop as large as 1 mT, for frequencies ranging from dc up to a few MHz. As an application, we demonstrate direct detection of NMR from {sup 1}H spins in a glycerol droplet placed directly on top of the 20 μm SQUID loops.

  10. Nuclear relaxation in an electric field enables the determination of isotropic magnetic shielding

    Science.gov (United States)

    Garbacz, Piotr

    2016-08-01

    It is shown that in contrast to the case of nuclear relaxation in a magnetic field B, simultaneous application of the magnetic field B and an additional electric field E causes transverse relaxation of a spin-1/2 nucleus with the rate proportional to the square of the isotropic part of the magnetic shielding tensor. This effect can contribute noticeably to the transverse relaxation rate of heavy nuclei in molecules that possess permanent electric dipole moments. Relativistic quantum mechanical computations indicate that for 205Tl nucleus in a Pt-Tl bonded complex, Pt(CN)5Tl, the transverse relaxation rate induced by the electric field is of the order of 1 s-1 at E = 5 kV/mm and B = 10 T.

  11. NUCLEAR-MAGNETIC MINI-RELAXOMETER FOR LIQUID AND VISCOUS MEDIA CONTROL

    Directory of Open Access Journals (Sweden)

    V. V. Davydov

    2015-01-01

    Full Text Available The paper deals with a new method for registration of nuclear magnetic resonance signal of small volume liquid and viscous media being studied (0.5 ml in a weak magnetic field (0.06 –0.08 T, and measuring of longitudinal T1 and transverse T2 relaxation constants. A new construction of NMR mini-relaxometer magnetic system is developed for registration of NMR signal. The nonuniformity of a magnetic field in a pole where registration coil is located is 0,410–3 sm–1 (the induction is В0 = 0.079 T. An electrical circuit of autodyne receiver (weak fluctuations generator has been developed with usage of low noise differential amplifier and NMR signal operating and control scheme (based on microcontroller STM32 for measuring of relaxation constants of liquid and viscous media in automatic operating mode. New technical decisions made it possible to improve relaxometer response time and dynamic range of measurements for relaxation constants T1 and T2 in comparison with small sized nuclear-magnetic spectrometer developed by the authors earlier (with accuracy characteristics conservation. The developed schemes for self-tuning of registration frequency, generating amplitude of magnetic field H1 in registration coil, and amplitude and frequency of modulating field provide measuring of T1 and T2 with error less than 0.5 % and signal to noise ratio about 1.2 in temperature range from 3 to 400 C. A new construction of mini-relaxometer reduced the weight of the device to 4 kg (with independent supply unit and increased transportability and operating convenience.

  12. Direct current superconducting quantum interference device spectrometer for pulsed nuclear magnetic resonance and nuclear quadrupole resonance at frequencies up to 5 MHz

    Science.gov (United States)

    TonThat, Dinh M.; Clarke, John

    1996-08-01

    A spectrometer based on a dc superconducting quantum interference device (SQUID) has been developed for the direct detection of nuclear magnetic resonance (NMR) or nuclear quadrupole resonance (NQR) at frequencies up to 5 MHz. The sample is coupled to the input coil of the niobium-based SQUID via a nonresonant superconducting circuit. The flux locked loop involves the direct offset integration technique with additional positive feedback in which the output of the SQUID is coupled directly to a low-noise preamplifier. Precession of the nuclear quadrupole spins is induced by a magnetic field pulse with the feedback circuit disabled; subsequently, flux locked operation is restored and the SQUID amplifies the signal produced by the nuclear free induction signal. The spectrometer has been used to detect 27Al NQR signals in ruby (Al2O3[Cr3+]) at 359 and 714 kHz.

  13. A Neutron Diffraction Study of the Nuclear and Magnetic Structure of MnNb2O6

    DEFF Research Database (Denmark)

    Nielsen, Oliver Vindex; Lebech, Bente; Krebs Larsen, F.;

    1976-01-01

    A neutron diffraction study was made of the nuclear and the magnetic structure of MnNb2O6 single crystals. The thirteen nuclear parameters (space group Pbcn) were determined from 304 reflections at room temperature. The antiferromagnetic structure (Neel temperature=4.4K), determined at 1.2K, is a...

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

    Science.gov (United States)

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

    2015-03-01

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

  15. Homometallic and Heterometallic Antiferromagnetic Rings: Magnetic Properties Studied by Nuclear Magnetic Resonance

    Energy Technology Data Exchange (ETDEWEB)

    Casadei, Cecilia [Univ. of Pavia (Italy)

    2011-01-01

    The aim of the present thesis is to investigate the local magnetic properties of homometallic Cr8 antiferromagnetic (AFM) ring and the changes occurring by replacing one Cr3+ ion with diamagnetic Cd2+ (Cr7Cd) and with Ni2+ (Cr7Ni). In the heterometallic ring a redistribution of the local magnetic moment is expected in the low temperature ground state. We have investigated those changes by both 53Cr-NMR and 19F-NMR. We have determined the order of magnitude of the transferred hyperfine coupling constant 19F - M+ where M+ = Cr3+, Ni2+ in the different rings. This latter result gives useful information about the overlapping of the electronic wavefunctions involved in the coordinative bond.

  16. Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Jeffry Todd

    2004-12-21

    Experimental and theoretical research conducted in two areas in the field of nuclear magnetic resonance (NMR) spectroscopy is presented: (1) studies of the coherent quantum-mechanical control of the angular momentum dynamics of quadrupolar (spin I > 1/2) nuclei and its application to the determination of molecular structure; and (2) applications of the long-range nuclear dipolar field to novel NMR detection methodologies.The dissertation is organized into six chapters. The first two chapters and associated appendices are intended to be pedagogical and include an introduction to the quantum mechanical theory of pulsed NMR spectroscopy and the time dependent theory of quantum mechanics. The third chapter describes investigations of the solid-state multiple-quantum magic angle spinning (MQMAS) NMR experiment applied to I = 5/2 quadrupolar nuclei. This work reports the use of rotary resonance-matched radiofrequency irradiation for sensitivity enhancement of the I = 5/2 MQMAS experiment. These experiments exhibited certain selective line narrowing effects which were investigated theoretically.The fourth chapter extends the discussion of multiple quantum spectroscopy of quadrupolar nuclei to a mostly theoretical study of the feasibility of enhancing the resolution of nitrogen-14 NMR of large biomolecules in solution via double-quantum spectroscopy. The fifth chapter continues to extend the principles of multiple quantum NMR spectroscopy of quadrupolar nuclei to make analogies between experiments in NMR/nuclear quadrupolar resonance (NQR) and experiments in atomic/molecular optics (AMO). These analogies are made through the Hamiltonian and density operator formalism of angular momentum dynamics in the presence of electric and magnetic fields.The sixth chapter investigates the use of the macroscopic nuclear dipolar field to encode the NMR spectrum of an analyte nucleus indirectly in the magnetization of a sensor nucleus. This technique could potentially serve as an

  17. Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Jeffry Todd [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    Experimental and theoretical research conducted in two areas in the field of nuclear magnetic resonance (NMR) spectroscopy is presented: (1) studies of the coherent quantum-mechanical control of the angular momentum dynamics of quadrupolar (spin I > 1/2) nuclei and its application to the determination of molecular structure; and (2) applications of the long-range nuclear dipolar field to novel NMR detection methodologies.The dissertation is organized into six chapters. The first two chapters and associated appendices are intended to be pedagogical and include an introduction to the quantum mechanical theory of pulsed NMR spectroscopy and the time dependent theory of quantum mechanics. The third chapter describes investigations of the solid-state multiple-quantum magic angle spinning (MQMAS) NMR experiment applied to I = 5/2 quadrupolar nuclei. This work reports the use of rotary resonance-matched radiofrequency irradiation for sensitivity enhancement of the I = 5/2 MQMAS experiment. These experiments exhibited certain selective line narrowing effects which were investigated theoretically.The fourth chapter extends the discussion of multiple quantum spectroscopy of quadrupolar nuclei to a mostly theoretical study of the feasibility of enhancing the resolution of nitrogen-14 NMR of large biomolecules in solution via double-quantum spectroscopy. The fifth chapter continues to extend the principles of multiple quantum NMR spectroscopy of quadrupolar nuclei to make analogies between experiments in NMR/nuclear quadrupolar resonance (NQR) and experiments in atomic/molecular optics (AMO). These analogies are made through the Hamiltonian and density operator formalism of angular momentum dynamics in the presence of electric and magnetic fields.The sixth chapter investigates the use of the macroscopic nuclear dipolar field to encode the NMR spectrum of an analyte nucleus indirectly in the magnetization of a sensor nucleus. This technique could potentially serve as an

  18. High-resolution liquid- and solid-state nuclear magnetic resonance of nanoliter sample volumes using microcoil detectors

    NARCIS (Netherlands)

    Kentgens, A.P.M.; Bart, J.; Bentum, van P.J.M.; Brinkmann, A.; Eck, van E.R.H.; Gardeniers, J.G.E.; Janssen, J.W.G.; Knijn, P.J.; Vasa, S.; Verkuijlen, M.H.W.

    2008-01-01

    The predominant means to detect nuclear magnetic resonance(NMR) is to monitor the voltage induced in a radiofrequency coil by the precessing magnetization. To address the sensitivity of NMR for mass-limited samples it is worthwhile to miniaturize this detector coil. Although making smaller coils see

  19. Modeling the nuclear magnetic resonance behavior of lung: from electrical engineering to critical care medicine.

    Science.gov (United States)

    Cutillo, A G; Ailion, D C

    1999-01-01

    The present article reviews the basic principles of a new approach to the characterization of pulmonary disease. This approach is based on the unique nuclear magnetic resonance (NMR) properties of the lung and combines experimental measurements (using specially developed NMR techniques) with theoretical simulations. The NMR signal from inflated lungs decays very rapidly compared with the signal from completely collapsed (airless) lungs. This phenomenon is due to the presence of internal magnetic field inhomogeneity produced by the alveolar air-tissue interface (because air and water have different magnetic susceptibilities). The air-tissue interface effects can be detected and quantified by magnetic resonance imaging (MRI) techniques using temporally symmetric and asymmetric spin-echo sequences. Theoretical models developed to explain the internal (tissue-induced) magnetic field inhomogeneity in aerated lungs predict the NMR lung behavior as a function of various technical and physiological factors (e.g., the level of lung inflation) and simulate the effects of various lung disorders (in particular, pulmonary edema) on this behavior. Good agreement has been observed between the predictions obtained from the mathematical models and the results of experimental NMR measurements in normal and diseased lungs. Our theoretical and experimental data have important pathophysiological and clinical implications, especially with respect to the characterization of acute lung disease (e.g., pulmonary edema) and the management of critically ill patients.

  20. Zero-field NMR and NQR studies of magnetically ordered state in charge-ordered EuPtP

    Science.gov (United States)

    Koyama, T.; Maruyama, T.; Ueda, K.; Mito, T.; Mitsuda, A.; Umeda, M.; Sugishima, M.; Wada, H.

    2015-03-01

    EuPtP undergoes two valence transitions and has two kinds of valence states of Eu ions at low temperatures. In the charge-ordered state, this compound shows an antiferromagnetic order ascribed to magnetic divalent Eu ions. We investigated the antiferromagnetically ordered state of EuPtP by nuclear magnetic resonance (NMR) measurement and nuclear quadrupole resonance (NQR) measurement in a zero external magnetic field. The observed 153Eu NMR signals of a magnetic divalent state and Eu,153151 NQR signals of a nonmagnetic trivalent state clearly demonstrate that the spins order in the hexagonal basal plane and the internal magnetic field is not canceled out, even at the Eu3 + layers which are in the middle of magnetic Eu2 + layers. In addition, the observation of 31P and 195Pt NMR spectra allowed us to discuss a possible magnetic structure. We also evaluated the nuclear quadrupole frequencies for both Eu2 + and Eu3 + ion states.

  1. High-sensitivity cooled coil system for nuclear magnetic resonance in kHz range.

    Science.gov (United States)

    Lin, Tingting; Zhang, Yi; Lee, Yong-Ho; Krause, Hans-Joachim; Lin, Jun; Zhao, Jing

    2014-11-01

    In several low-field Nuclear Magnetic Resonance (LF-NMR) and surface nuclear magnetic resonance applications, i.e., in the frequency range of kHz, high sensitivity magnetic field detectors are needed. Usually, low-Tc superconducting quantum interference devices (SQUIDs) with a high field sensitivity of about 1 fT/Hz(1/2) are employed as detectors. Considering the flux trapping and operational difficulties associated with low-Tc SQUIDs, we designed and fabricated liquid-nitrogen-cooled Cu coils for NMR detection in the kHz range. A cooled coil system consisting of a 9-cm diameter Cu coil and a low noise preamplifier was systematically investigated and reached a sensitivity of 2 fT/Hz(1/2) at 77 K, which is 3 times better compared to the sensitivity at 300 K. A Q-switch circuit as an essential element for damping the ringing effects of the pickup coil was developed to acquire free induction decay signals of a water sample with minimum loss of signal. Our studies demonstrate that cooled Cu coils, if designed properly, can provide a comparable sensitivity to low-Tc SQUIDs.

  2. Muscle bio-energetics in acute glycolytic block: in vivo phosphorus-nuclear magnetic resonance study of iodo-acetate injected rats.

    Science.gov (United States)

    Argov, Z; Nagle, D; Giger, U; Leigh, J S

    1989-01-01

    In vivo phosphorus nuclear magnetic resonance spectroscopy of muscle was performed at rest, during work and during postexercise recovery in rats injected with iodo-acetate (IA) (35-40 mg.kg-1, intra-arterially), in order to follow bio-energetic changes in muscle with acute glycolytic block. Three animals with contracture had very low ratios of phosphocreatine:inorganic phosphate (PCr:Pi) at rest (0.5-0.9). The PCr:Pi were normal at rest (6.9 +/- 2.0, +/- 2 SD) in all other rats. Exercise-induced continuous accumulation of phosphomonoesters (PME), the characteristic finding of glycolytic block, was observed. The end-exercise levels of PME correlated with the degree of block measured in vitro. During steady-state work, induced by nerve stimulation at four frequencies, PCr:Pi values were significantly lower (p less than 0.02) than the control values at 0.25, 1.0 and 2.0 Hz. The ATP levels fell during exercise to reach 75% +/- 7% of initial values. The recovery of PCr:Pi from exercise and the disappearance of PME were slow. Two animals which survived the IA injection demonstrated much lower PME accumulation 18 h later. It is concluded that in acute muscle glycolytic block: (1) energy metabolism is impaired during exercise and also at rest, (2) accumulating PME can serve as an indicator of the degree of glycolytic block, (3) ATP levels fall during work, and (4) postexercise recovery is slow. The findings are compared with 31P-NMR observations in chronic muscle glycolytic disorders.

  3. Metabolic Pathway for Propionate Utilization by Phosphorus-Accumulating Organisms in Activated Sludge: 13C Labeling and In Vivo Nuclear Magnetic Resonance

    Science.gov (United States)

    Lemos, Paulo C.; Serafim, Luísa S.; Santos, Margarida M.; Reis, Maria A. M.; Santos, Helena

    2003-01-01

    In vivo 13C and 31P nuclear magnetic resonance techniques were used to study propionate metabolism by activated sludge in enhanced biological phosphorus removal systems. The fate of label supplied in [3-13C]propionate was monitored in living cells subjected to anaerobic/aerobic cycles. During the anaerobic phase, propionate was converted to polyhydroxyalkanoates (PHA) with the following monomer composition: hydroxyvalerate, 74.2%; hydroxymethylvalerate, 16.9%; hydroxymethylbutyrate, 8.6%; and hydroxybutyrate, 0.3%. The isotopic enrichment in the different carbon atoms of hydroxyvalerate (HV) produced during the first anaerobic stage was determined: HV5, 59%; HV4, 5.0%; HV3, 1.1%; HV2, 3.5%; and HV1, 2.8%. A large proportion of the supplied label ended up on carbon C-5 of HV, directly derived from the pool of propionyl-coenzyme A (CoA), which is primarily labeled on C-3; useful information on the nature of operating metabolic pathways was provided by the extent of labeling on C-1, C-2, and C-4. The labeling pattern on C-1 and C-2 was explained by the conversion of propionyl-CoA to acetyl-CoA via succinyl-CoA and the left branch of the tricarboxylic acid cycle, which involves scrambling of label between the inner carbons of succinate. This constitutes solid evidence for the operation of succinate dehydrogenase under anaerobic conditions. The labeling in HV4 is explained by backflux from succinate to propionyl-CoA. The involvement of glycogen in the metabolism of propionate was also demonstrated; moreover, it was shown that the acetyl moiety to the synthesis of PHA was derived preferentially from glycogen. According to the proposed metabolic scheme, the decarboxylation of pyruvate is coupled to the production of hydrogen, and the missing reducing equivalents should be derived from a source other than glycogen metabolism. PMID:12514001

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

    Science.gov (United States)

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

    2012-10-01

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

  5. Study of the thermal neutron radiative capture sup 31 P( n ,. gamma. ) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Zeng Xiantang; Shi Zongren; Zhang Ming; Li Guohua; Ding Dazhao (Institute of Atomic Energy, P. O. Box 275, Beijing (CN))

    1989-05-01

    The measurement of the {gamma}-ray spectrum of the {sup 31}P({ital n},{gamma}) reaction induced by thermal neutrons from the heavy water reactor is performed by using three crystal pair spectrometer'', Ge(Li) and HPGe detectors. 128 {gamma}-rays are identified, 24 of them are recognized as primary {gamma}-transitions. The excitation energies of 32 levels are deduced. Two possible levels of 5451.44 keV and 5021.10 keV have not been reported previously. The neutron separation energy is determined to be 7936.65(8) keV and partial cross sections are measured. The thermal neutron capture cross section of {sup 31}P is obtained to be 177(5) mb by comparison with Au({ital n}{sub th}, {gamma}) cross section standard. With the formula of the Lane-Lynn direct interaction, the partial capture cross sections of eight strong primary E1-transitions are calculated and compared with their experimental values, leading to the conclusion that the theoretical values are in coincidence with the experimental ones and the E1-transitions mainly come from 1+ capture state. The correlation analyses of the reduced strengths of E1 and M1 transitions with the spectroscopic factors of (d, p) reaction are performed and the reaction mechanisms discussed.

  6. Time-Reversal Symmetry Violation in Molecules Induced by Nuclear Magnetic Quadrupole Moments

    Science.gov (United States)

    Flambaum, V. V.; DeMille, D.; Kozlov, M. G.

    2014-09-01

    Recent measurements in paramagnetic molecules improved the limit on the electron electric dipole moment (EDM) by an order of magnitude. Time-reversal (T) and parity (P) symmetry violation in molecules may also come from their nuclei. We point out that nuclear T, P-odd effects are amplified in paramagnetic molecules containing deformed nuclei, where the primary effects arise from the T, P-odd nuclear magnetic quadrupole moment (MQM). We perform calculations of T, P-odd effects in the molecules TaN, ThO, ThF+, HfF+, YbF, HgF, and BaF induced by MQMs. We compare our results with those for the diamagnetic TlF molecule, where the T, P-odd effects are produced by the nuclear Schiff moment. We argue that measurements in molecules with MQMs may provide improved limits on the strength of T, P-odd nuclear forces, on the proton, neutron, and quark EDMs, on quark chromo-EDMs, and on the QCD θ term and CP-violating quark interactions.

  7. Effects of temperature and extracellular pH on metabolites: kinetics of anaerobic metabolism in resting muscle by 31P- and 1H-NMR spectroscopy.

    Science.gov (United States)

    Vezzoli, Alessandra; Gussoni, Maristella; Greco, Fulvia; Zetta, Lucia

    2003-09-01

    Environmental stress, such as low temperature, extracellular acidosis and anoxia, is known to play a key role in metabolic regulation. The aim of the present study was to gain insight into the combined temperature-pH regulation of metabolic rate in frog muscle, i.e. an anoxia-tolerant tissue. The rate of exergonic metabolic processes occurring in resting isolated muscles was determined at 15 degrees C and 25 degrees C as well as at extracellular pH values higher (7.9), similar (7.3) and lower (7.0) than the physiological intracellular pH. (31)P and (1)H nuclear magnetic resonance spectroscopy high-resolution measurements were carried out at 4.7 T in isolated frog (Rana esculenta) gastrocnemius muscle during anoxia to assess, by means of reference compounds, the concentration of all phosphate metabolites and lactate. Intra- and extracellular pH was also determined. In the range of examined temperatures (15-25 degrees C), the temperature dependence of anaerobic glycolysis was found to be higher than that of PCr depletion (Q(10)=2.3). High-energy phosphate metabolism was confirmed to be the initial and preferential energy source. The rate of phosphocreatine hydrolysis did not appear to be affected by extracellular pH changes. By contrast, independent of the intracellular pH value, at the higher temperature (25 degrees C) a lowering of the extracellular pH from 7.9 to 7.0 caused a depression in lactate accumulation. This mechanism was ascribed to the transmembrane proton concentration gradient. This parameter was demonstrated to regulate glycolysis, probably through a reduced lactate efflux, depending on the activity of the lactate-H(+) co-transporter. The calculated intracellular buffer capacity was related to intra- and extracellular pH and temperature. At the experimental extracellular pH of 7.9 and at a temperature of 15 degrees C and 25 degrees C, calculated intracellular buffering capacity was 29.50 micromol g(-1) pH unit(-1) and 69.98 micromol g(-1) pH unit(-1

  8. high resolution nuclear magnetic resonance spectroscopy in studies of Picrotoxanolides of Coriaria. Coryamyrtin

    Directory of Open Access Journals (Sweden)

    Aguirre Galvis Luis Enrique

    1987-06-01

    Full Text Available Spectral evidence by Protonic Nuclear Magnetic Resonance (400
    MAHz and 90 MHz of the analeptic sesquiterpene lactone coriamyrtin, isolated from the colombian plant Coriaria microphyUn, Poir., is discussed, and analogies are made with the spectra of authentic samples of picrotin and picrotoxinin.Se discute la evidencia espectroscópica de Resonancia Magnética
    Nuclear Protónica (400MHz y 90 MHz para coriamirtina, una lactona sesquiterpénica de carácter analéptico, aislada de la planta colombiana Coriasia microphyUn, Poir., mediante analogías con espectros de muestras autenticadas de picrotina y picrotoxinina.

  9. Billion-Fold Enhancement in Sensitivity of Nuclear Magnetic Resonance Spectroscopy for Magnesium Ions in Solution

    CERN Document Server

    Gottberg, Alexander; Kowalska, Magdalena; Bissell, Mark L; Arcisauskaite, Vaida; Blaum, Klaus; Helmke, Alexander; Johnston, Karl; Kreim, Kim; Larsen, Flemming H; Neugart, Rainer; Neyens, Gerda; Garcia Ruiz, Ronald F; Szunyogh, Daniel; Thulstrup, Peter W; Yordanov, Deyan T; Hemmingsen, Lars

    2014-01-01

    β-nuclear magnetic resonance (NMR) spectroscopy is highly sensitive compared to conventional NMR spectroscopy, and may be applied for several elements across the periodic table. β-NMR has previously been successfully applied in the fields of nuclear and solid-state physics. In this work, β-NMR is applied, for the first time, to record an NMR spectrum for a species in solution. 31Mg β-NMR spectra are measured for as few as 107 magnesium ions in ionic liquid (EMIM-Ac) within minutes, as a prototypical test case. Resonances are observed at 3882.9 and 3887.2 kHz in an external field of 0.3 T. The key achievement of the current work is to demonstrate that β-NMR is applicable for the analysis of species in solution, and thus represents a novel spectroscopic technique for use in general chemistry and potentially in biochemistry.

  10. Antisymmetric Couplings Enable Direct Observation of Chirality in Nuclear Magnetic Resonance Spectroscopy

    CERN Document Server

    King, Jonathan P; Blanchard, John W

    2016-01-01

    Here we demonstrate that a term in the nuclear spin Hamiltonian, the antisymmetric \\textit{J}-coupling, is fundamentally connected to molecular chirality. We propose and simulate a nuclear magnetic resonance (NMR) experiment to observe this interaction and differentiate between enantiomers without adding any additional chiral agent to the sample. The antisymmetric \\textit{J}-coupling may be observed in the presence of molecular orientation by an external electric field. The opposite parity of the antisymmetric coupling tensor and the molecular electric dipole moment yields a sign change of the observed coupling between enantiomers. We show how this sign change influences the phase of the NMR spectrum and may be used to discriminate between enantiomers.

  11. Relativistic effects in the intermolecular interaction-induced nuclear magnetic resonance parameters of xenon dimer

    DEFF Research Database (Denmark)

    Hanni, Matti; Lantto, Perttu; Ilias, Miroslav

    2007-01-01

    Relativistic effects on the 129Xe nuclear magnetic resonance shielding and 131Xe nuclear quadrupole coupling (NQC) tensors are examined in the weakly bound Xe2 system at different levels of theory including the relativistic four-component Dirac-Hartree-Fock (DHF) method. The intermolecular...... interaction-induced binary chemical shift d, the anisotropy of the shielding tensor ?s, and the NQC constant along the internuclear axis ?ll are calculated as a function of the internuclear distance. DHF shielding calculations are carried out using gauge-including atomic orbitals. For comparison, the full...... leading-order one-electron Breit-Pauli perturbation theory (BPPT) is applied using a common gauge origin. Electron correlation effects are studied at the nonrelativistic (NR) coupled-cluster singles and doubles with perturbational triples [CCSD(T)] level of theory. The fully relativistic second...

  12. Billion-fold enhancement in sensitivity of nuclear magnetic resonance spectroscopy for magnesium ions in solution.

    Science.gov (United States)

    Gottberg, Alexander; Stachura, Monika; Kowalska, Magdalena; Bissell, Mark L; Arcisauskaite, Vaida; Blaum, Klaus; Helmke, Alexander; Johnston, Karl; Kreim, Kim; Larsen, Flemming H; Neugart, Rainer; Neyens, Gerda; Garcia Ruiz, Ronald F; Szunyogh, Daniel; Thulstrup, Peter W; Yordanov, Deyan T; Hemmingsen, Lars

    2014-12-15

    β-nuclear magnetic resonance (NMR) spectroscopy is highly sensitive compared to conventional NMR spectroscopy, and may be applied for several elements across the periodic table. β-NMR has previously been successfully applied in the fields of nuclear and solid-state physics. In this work, β-NMR is applied, for the first time, to record an NMR spectrum for a species in solution. (31)Mg β-NMR spectra are measured for as few as 10(7) magnesium ions in ionic liquid (EMIM-Ac) within minutes, as a prototypical test case. Resonances are observed at 3882.9 and 3887.2 kHz in an external field of 0.3 T. The key achievement of the current work is to demonstrate that β-NMR is applicable for the analysis of species in solution, and thus represents a novel spectroscopic technique for use in general chemistry and potentially in biochemistry.

  13. Implementation of a multiple round quantum dense coding using nuclear magnetic resonance

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Jingfu; XIE; Jingyi; WANG; Chuan; DENG; Zhiwei; LU

    2005-01-01

    A multiple round quantum dense coding scheme based on the quantum phase estimation algorithm is proposed and implemented in a three qubit nuclear magnetic resonance (NMR) quantum computer. Using an m + 1 qubit system, Bob can transmit one of 2m+1 messages to Alice, through manipulating only one qubit and exchanging it between Alice and Bob for m rounds. The information capacity is enhanced to m + 1 bits as compared to m bits in a classical scheme. The scheme has been demonstrated in NMR system, and the experimental results show a good agreement between theory and experiment.

  14. Recent Advances in Computational Methods for Nuclear Magnetic Resonance Data Processing

    KAUST Repository

    Gao, Xin

    2013-01-11

    Although three-dimensional protein structure determination using nuclear magnetic resonance (NMR) spectroscopy is a computationally costly and tedious process that would benefit from advanced computational techniques, it has not garnered much research attention from specialists in bioinformatics and computational biology. In this paper, we review recent advances in computational methods for NMR protein structure determination. We summarize the advantages of and bottlenecks in the existing methods and outline some open problems in the field. We also discuss current trends in NMR technology development and suggest directions for research on future computational methods for NMR.

  15. Determination of alkylbenzenesulfonate surfactants in groundwater using macroreticular resins and carbon-13 nuclear magnetic resonance spectrometry

    Science.gov (United States)

    Thurman, E.M.; Willoughby, T.; Barber, L.B.; Thorn, K.A.

    1987-01-01

    Alkylbenzenesulfonate surfactants were determined in groundwater at concentrations as low as 0.3 mg/L. The method uses XAD-8 resin for concentration, followed by elution with methanol, separation of anionic and nonionic surfactants by anion exchange, quantitation by titration, and identification by 13C nuclear magnetic resonance spectrometry. Laboratory standards and field samples containing straight-chain and branched-chain alkylbenzenesulfonates, sodium dodecyl sulfate, and alkylbenzene ethoxylates were studied. The XAD-8 extraction of surfactants from groundwater was completed in the field, which simplified sample preservation and reduced the cost of transporting samples.

  16. Development of Nuclear Magnetic Resonance Imaging/spectroscopy for improved petroleum recovery. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barrufet, M.A.; Flumerfelt, F.W.; Walsh, M.P.; Watson, A.T.

    1994-04-01

    The overall objectives of this program are to develop and apply Nuclear Magnetic Resonance Imaging (NMRI) and CT X-Ray Scanning methods for determining rock, fluid, and petrophysical properties and for fundamental studies of multiphase flow behavior in porous media. Specific objectives are divided into four subtasks: (1) development of NMRI and CT scanning for the determination of rock-fluid and petrophysical properties; (2) development of NMRI and CT scanning for characterizing conventional multiphase displacement processes; (3) development of NMR and CT scanning for characterizing dispersed phase processes; and (4) miscible displacement studies.

  17. Geometric optimal control of the contrast imaging problem in Nuclear Magnetic Resonance

    CERN Document Server

    Bonnard, B; Glaser, S J; Lapert, M; Sugny, D; Zhang, Y

    2012-01-01

    The objective of this article is to introduce the tools to analyze the contrast imaging problem in Nuclear Magnetic Resonance. Optimal trajectories can be selected among extremal solutions of the Pontryagin Maximum Principle applied to this Mayer type optimal problem. Such trajectories are associated to the question of extremizing the transfer time. Hence the optimal problem is reduced to the analysis of the Hamiltonian dynamics related to singular extremals and their optimality status. This is illustrated by using the examples of cerebrospinal fluid / water and grey / white matter of cerebrum.

  18. Differentiation in vitro of inflammatory from non inflammatory synovial fluid by nuclear magnetic relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Teyssier, R.; Teyssier, M.; Colson, F.

    1987-01-01

    The differentiation between inflammatory and non inflammatory states has been performed using Nuclear Magnetic Resonance (NMR) in vitro by measuring relaxation times T/sub 1/ and T/sub 2/ in 84 synovials fluids obtained from various rheumatologic diseases. The results show that the T/sub 1//T/sub 2/ ratio is more sensitive to distinguish these two situations rather than the isolated T/sub 1/ or T/sub /2 values. In particular, high values of T/sub 1//T/sub 2/ ratio are found in septic arthritis.

  19. Isotropic proton-detected local-field nuclear magnetic resonancein solids

    Energy Technology Data Exchange (ETDEWEB)

    Havlin, Robert H.; Walls, Jamie D.; Pines, Alexander

    2004-08-04

    A new nuclear magnetic resonance (NMR) method is presented which produces linear, isotropic proton-detected local-field spectra for InS spin systems in powdered samples. The method, HETeronuclear Isotropic Evolution (HETIE), refocuses the anisotropic portion of the heteronuclear dipolar coupling frequencies by evolving the system under a series of specially designed Hamiltonians and evolution pathways. The theory behind HETIE is represented along with experimental studies conducted on a powdered sample of ferrocene, demonstrating the methodology outlined in this paper. Applications of HETIE for structural determination in solid-state NMR are discussed.

  20. Molecular Structure Laboratory. Fourier Transform Nuclear Magnetic Resonance (FTNMR) Spectrometer and Ancillary Instrumentation at SUNY Geneseo

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, David K [State Univ. of New York (SUNY), Geneseo, NY (United States)

    2015-12-31

    An Agilent 400-MR nuclear magnetic resonance (NMR) spectrometer and ancillary equipment were purchased, which are being used for molecular structure elucidation.  The instrumentation is housed in a pre-existing facility designed specifically for its use. This instrument package is being used to expand the research and educational efforts of the faculty and students at SUNY-Geneseo and is made available to neighboring educational institutions and business concerns.  Funds were also used for training of College personnel, maintenance of the instrumentation, and installation of the equipment.

  1. Experimental study of quantum simulation for quantum chemistry with a nuclear magnetic resonance simulator.

    Science.gov (United States)

    Lu, Dawei; Xu, Nanyang; Xu, Boruo; Li, Zhaokai; Chen, Hongwei; Peng, Xinhua; Xu, Ruixue; Du, Jiangfeng

    2012-10-13

    Quantum computers have been proved to be able to mimic quantum systems efficiently in polynomial time. Quantum chemistry problems, such as static molecular energy calculations and dynamical chemical reaction simulations, become very intractable on classical computers with scaling up of the system. Therefore, quantum simulation is a feasible and effective approach to tackle quantum chemistry problems. Proof-of-principle experiments have been implemented on the calculation of the hydrogen molecular energies and one-dimensional chemical isomerization reaction dynamics using nuclear magnetic resonance systems. We conclude that quantum simulation will surpass classical computers for quantum chemistry in the near future.

  2. Development of Nuclear Magnetic Resonance Imaging/spectroscopy for improved petroleum recovery. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barrufet, M.A.; Flumerfelt, F.W.; Walsh, M.P.; Watson, A.T.

    1994-04-01

    The overall objectives of this program are to develop and apply Nuclear Magnetic Resonance Imaging (NMRI) and CT X-Ray Scanning methods for determining rock, fluid, and petrophysical properties and for fundamental studies of multiphase flow behavior in porous media. Specific objectives are divided into four subtasks: (1) development of NMRI and CT scanning for the determination of rock-fluid and petrophysical properties; (2) development of NMRI and CT scanning for characterizing conventional multiphase displacement processes; (3) development of NMR and CT scanning for characterizing dispersed phase processes; and (4) miscible displacement studies.

  3. Combining Nuclear Magnetic Resonance Spectroscopy and Density Functional Theory Calculations to Characterize Carvedilol Polymorphs.

    Science.gov (United States)

    Rezende, Carlos A; San Gil, Rosane A S; Borré, Leandro B; Pires, José Ricardo; Vaiss, Viviane S; Resende, Jackson A L C; Leitão, Alexandre A; De Alencastro, Ricardo B; Leal, Katia Z

    2016-09-01

    The experiments of carvedilol form II, form III, and hydrate by (13)C and (15)N cross-polarization magic-angle spinning (CP MAS) are reported. The GIPAW (gauge-including projector-augmented wave) method from DFT (density functional theory) calculations was used to simulate (13)C and (15)N chemical shifts. A very good agreement was found for the comparison between the global results of experimental and calculated nuclear magnetic resonance (NMR) chemical shifts for carvedilol polymorphs. This work aims a comprehensive understanding of carvedilol crystalline forms employing solution and solid-state NMR as well as DFT calculations.

  4. In situ nuclear magnetic resonance microimaging of live biofilms in a microchannel

    Energy Technology Data Exchange (ETDEWEB)

    Renslow, Ryan S.; Marshall, Matthew J.; Tucker, Abigail E.; Chrisler, William B.; Yu, Xiao-Ying

    2017-01-01

    Nuclear magnetic resonance (NMR) microimaging and spectroscopy was used to interrogate fluids of biological importance (e.g., water, buffer, medium solution) and live biofilms in a microchannel compatible for analyses at ambient pressure and under vacuum. Studies using buffer, growth medium, and actively growing Shewanella oneidensis biofilms were used to demonstrate in situ NMR microimaging measurement capabilities including velocity mapping, diffusion coefficient mapping, relaxometry, localized spectroscopy, and 2D and 3D imaging within a microchannel suitable for different analytical platforms. This technique is promising for diverse applications of correlative imaging using a portable microfluidic platform.

  5. Nuclear Magnetic Resonance and Elastic Wave Velocity of Chalk Saturated with Brines Containing Divalent Ions

    DEFF Research Database (Denmark)

    Katika, Konstantina; Alam, Mohammad Monzurul; Fabricius, Ida Lykke

    Nuclear magnetic resonance (NMR) has proven a good technique for measuring pore size distribution in reservoir rocks. The use of low field NMR together with sonic and electrical resistivity measurements, can contribute to illustrate the effect of adsorbing ions on chalk elasticity. NMR is useful...... of the relaxation time. Core samples saturated with calcium chloride solution relaxed slower and those saturated with magnesium chloride solution relaxed faster than the rest of the samples. Along with the changes in relaxation the samples experienced smaller velocities of elastic waves when saturated with MgCl2...

  6. Device for measurement of power and shape of radio frequency pulses in nuclear magnetic resonance

    Science.gov (United States)

    Pfeffer, M.; Řezníček, R.; Křišťan, P.; Štěpánková, H.

    2012-05-01

    A design of an instrument to measure the power and shape of radio frequency (RF) pulses operating in a broad frequency range is described. The device is capable of measuring the pulse power up to 500 W of both CW and extremely short (˜1 μs) RF pulses of arbitrary period. The pulse envelope can be observed on a logarithmic scale on a corresponding instrument output using an inexpensive storage oscilloscope. The instrument consists of a coaxial measurement head, the RF processing circuits and an AD conversion and display unit. The whole device is based on widely available integrated circuits; thus, good reproducibility and adaptability of the design is ensured. Since the construction is intended to be used in particular (but not solely) in nuclear magnetic resonance spectroscopy, we found it useful to provide a demonstration of two typical usage scenarios. Other application fields may comprise magnetic resonance imaging, radar and laser technology, power amplifier testing, etc.

  7. Educational simulator app and web page for exploring Nuclear and Compass Magnetic Resonance

    DEFF Research Database (Denmark)

    Hanson, Lars G.

    A graphical app and browser-based simulator, CompassMR, was developed for initial Magnetic Resonance (MR) education. It is available at http://drcmr.dk/CompassMR/ and executes directly in most browsers with no further need for software. Easy access and a simple user interface invite student...... experimentation that improves understanding of basic MR phenomena. The simulator is used to introduce and explore electromagnetism, magnetic dipoles, static and radiofrequency fields, Compass MR, the free induction decay (FID), relaxation, the Fourier transform (FFT), the resonance condition, spin, precession......, the Larmor equation, Nuclear MR, resonant excitation (linear and quadrature), and off-resonance effects. Methods and implementation: The simulator is a complete HTML5/JavaScript[1,2] rewrite of the JavaCompass[3] so it now executes in modern browsers with no additional software needed. Spin dynamics...

  8. Sub-nanoliter nuclear magnetic resonance coils fabricated with multilayer soft lithography

    Science.gov (United States)

    Lam, Matthew H. C.; Homenuke, Mark A.; Michal, Carl A.; Hansen, Carl L.

    2009-09-01

    We describe the fabrication and characterization of sub-nanoliter volume nuclear magnetic resonance (NMR) transceiver coils that are easily amenable to integration within PDMS-based microfluidics. NMR coils were constructed by the injection of liquid metal into solenoidal cavities created around a microchannel using consecutive replica molding and bonding of PDMS layers. This construction technique permits the integration of NMR coils with solenoidal, toroidal or other three-dimensional geometries within highly integrated microfluidic systems and are one step toward NMR-based chemical screening and analysis on chip. The current proof-of-principle implementation displays limited sensitivity and resolution due to the conductivity and magnetic susceptibilities of the construction materials. However, NMR measurements and finite-element simulations made with the current device geometry indicate that optimization of these materials will allow for the collection of spectra from sub-millimolar concentration samples in less than 1 nL of solution.

  9. A Magnetic Carbon Sorbent for Radioactive Material from the Fukushima Nuclear Accident

    Science.gov (United States)

    Yamaguchi, Daizo; Furukawa, Kazumi; Takasuga, Masaya; Watanabe, Koki

    2014-08-01

    Here we present the first report of a carbon-γ-Fe2O3 nanoparticle composite of mesoporous carbon, bearing COOH- and phenolic OH- functional groups on its surface, a remarkable and magnetically separable adsorbent, for the radioactive material emitted by the Fukushima Daiichi nuclear power plant accident. Contaminated water and soil at a level of 1,739 Bq kg-1 (134Cs and 137Cs at 509 Bq kg-1 and 1,230 Bq kg-1, respectively) and 114,000 Bq kg-1 (134Cs and 137Cs at 38,700 Bq kg-1 and 75,300 Bq kg-1, respectively) were decontaminated by 99% and 90% respectively with just one treatment carried out in Nihonmatsu city in Fukushima. Since this material is remarkably high performance, magnetically separable, and a readily applicable technology, it would reduce the environmental impact of the Fukushima accident if it were used.

  10. [sup 27]Al nuclear magnetic resonance spectra in CeAl[sub 3] at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Hunziker, J. (Lab. fuer Festkoerperphysik, ETH-Hoenggerberg, Zuerich (Switzerland)); Gavilano, J.L. (Lab. fuer Festkoerperphysik, ETH-Hoenggerberg, Zuerich (Switzerland)); Buechi, S. (Lab. fuer Festkoerperphysik, ETH-Hoenggerberg, Zuerich (Switzerland)); Ott, H.R. (Lab. fuer Festkoerperphysik, ETH-Hoenggerberg, Zuerich (Switzerland))

    1994-02-01

    We have measured the nuclear magnetic resonance, NMR, spectra of CeAl[sub 3] at 3.964 MHz, 2.095 MHz and 0.937 MHz in the temperature range between 0.04 K and 20 K. The complicated NMR absorption line of CeAl[sub 3] powder is shown to have more than one component, corresponding to at least two inequivalent Al sites. Below 0.9 K the relative intensity of a broad asymmetric structure increases, and the width of the NMR spectrum shows a rapid increase. At fields of the order of two kilogauss the asymmetry is strongly supressed. The temperature dependence of the asymmetry and width of the spectrum below 0.9 K, can neither be explained in terms of a temperature dependent Knight shift nor in terms of conventional magnetic ordering. (orig.)

  11. Contributed Review: Nuclear magnetic resonance core analysis at 0.3 T

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Jonathan, E-mail: JMitchell16@slb.com; Fordham, Edmund J. [Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL (United Kingdom)

    2014-11-15

    Nuclear magnetic resonance (NMR) provides a powerful toolbox for petrophysical characterization of reservoir core plugs and fluids in the laboratory. Previously, there has been considerable focus on low field magnet technology for well log calibration. Now there is renewed interest in the study of reservoir samples using stronger magnets to complement these standard NMR measurements. Here, the capabilities of an imaging magnet with a field strength of 0.3 T (corresponding to 12.9 MHz for proton) are reviewed in the context of reservoir core analysis. Quantitative estimates of porosity (saturation) and pore size distributions are obtained under favorable conditions (e.g., in carbonates), with the added advantage of multidimensional imaging, detection of lower gyromagnetic ratio nuclei, and short probe recovery times that make the system suitable for shale studies. Intermediate field instruments provide quantitative porosity maps of rock plugs that cannot be obtained using high field medical scanners due to the field-dependent susceptibility contrast in the porous medium. Example data are presented that highlight the potential applications of an intermediate field imaging instrument as a complement to low field instruments in core analysis and for materials science studies in general.

  12. Experimental investigations on the splitting of coherent population trapping resonances by the nuclear magnetic moment

    Energy Technology Data Exchange (ETDEWEB)

    Lammegger, Roland; Vasari, Ivan; Neureiter, Christian; Windholz, Laurentius [Inst. f. Experimentalphysik, Techn. Univ. Graz (Austria)

    2007-07-01

    Coherent population trapping (CPT) is a resonance phenomenon due to a quantum mechanical interference effect within an atomic system. The resonantly driven atomic level population is being trapped into a superpositional dark state, yielding the atomic medium transparent for the exciting electromagnetic fields. The observation of this effect requires a special electronic structure ({lambda}-system) and suitable lifetimes which can be found e.g. in alkali atoms. We present experimental investigations on the behavior of the CPT resonances split by the nuclear magnetic moment under different external magnetic fields, laser polarizations and laser intensities. We focus our considerations on a special type of the {lambda}-System formation. In this case the center of gravity of the pair of split CPT resonances (called pseudoresonance) is sensitive to external magnetic fields only to second order in the magnetic field strength. The short term frequency stability of this pseudoresonance approaches the level of 10{sup -14}/{radical}({tau}). Thus such resonances seems to be a good candidate for applications in compact atomic clocks used e.g. in GPS receivers and Satellites.

  13. Two lanthanide-hydroxo clusters with different nuclearity: Synthesis, structures, luminescent and magnetic properties

    Science.gov (United States)

    Li, Xi-Li; Zhu, Cancan; Zhang, Xue-Li; Hu, Ming; Wang, Ai-Ling; Xiao, Hong-Ping

    2017-01-01

    Under the identical reaction conditions, two new TbIII and SmIII-hydroxo clusters with different nuclearity have been prepared and characterized by X-ray crystallography, spectroscopic methods and magnetic measurements. Solid-state structure analyses reveal that the TbIII cluster shows a pentanuclear square pyramidal shape of the composition [Tb5(μ3-OH)4(μ4-OH)(dbm)10]·2H2O (1, dbm- = dibenzoylmethanate) with the dbm ligands presenting two types of coordination modes [η2-and (μ-O)-η2-]. The SmIII species presents a tetranuclear parallelogram structure formulated as [Sm4(μ3-OH)2(dbm)10]·12H2O (2), and three types of coordination modes [η2-, (μ-O)-η2- and (μ-O)2-η2-] for dbm ligands are observed. The measurements of magnetic properties indicate that the direct-current (dc) magnetic behaviors of two clusters mainly result from the thermal depopulation of the Stark sublevels of the TbIII and SmIII ions, respectively. Meanwhile, alternating current (ac) magnetic susceptibility of 1 is also assessed. Investigations on luminescence properties show that 2 displays characteristic emission of the SmIII ion in visible range, while 1 does not exhibit any detectable emission. The interpretations of different emission behaviors for 1 and 2 are also presented in detail.

  14. Contributed review: nuclear magnetic resonance core analysis at 0.3 T.

    Science.gov (United States)

    Mitchell, Jonathan; Fordham, Edmund J

    2014-11-01

    Nuclear magnetic resonance (NMR) provides a powerful toolbox for petrophysical characterization of reservoir core plugs and fluids in the laboratory. Previously, there has been considerable focus on low field magnet technology for well log calibration. Now there is renewed interest in the study of reservoir samples using stronger magnets to complement these standard NMR measurements. Here, the capabilities of an imaging magnet with a field strength of 0.3 T (corresponding to 12.9 MHz for proton) are reviewed in the context of reservoir core analysis. Quantitative estimates of porosity (saturation) and pore size distributions are obtained under favorable conditions (e.g., in carbonates), with the added advantage of multidimensional imaging, detection of lower gyromagnetic ratio nuclei, and short probe recovery times that make the system suitable for shale studies. Intermediate field instruments provide quantitative porosity maps of rock plugs that cannot be obtained using high field medical scanners due to the field-dependent susceptibility contrast in the porous medium. Example data are presented that highlight the potential applications of an intermediate field imaging instrument as a complement to low field instruments in core analysis and for materials science studies in general.

  15. Tunnel-diode resonator and nuclear magnetic resonance studies of low-dimensional magnetic and superconducting systems

    Science.gov (United States)

    Yeninas, Steven Lee

    This thesis emphasizes two frequency-domain techniques which uniquely employ radio frequency (RF) excitations to investigate the static and dynamic properties of novel magnetic and superconducting materials. The first technique is a tunnel-diode resonator (TDR) which detects bulk changes in the dynamic susceptibility, chi = dM/dH. The capability of TDR to operate at low temperatures (less than 100 mK) and high fields (up to 65 T in pulsed fields) was critical for investigations of the antiferromagnetically correlated magnetic molecules Cr12Cu2 and Cr12 Ln4 (Ln = Y, Eu, Gd, Tb, Dy, Ho, Er, Yb), and the superconductor SrFe2(As1--xPx) 2 (x = 0.35). Investigations of Cr12Cu 2 and Cr12Ln4 demonstrates the first implementation of TDR to experimentally investigate the lowlying energy spectra of magnetic molecules in pulsed magnetic fields. Zeeman splitting of the quantum spin states results in transitions between field-dependent ground state energy levels observed as peaks in dM/dH at 600 mK, and demonstrate good agreement with theoretical calculations using a isotropic Heisenberg spin Hamiltonian. Increasing temperature to 2.5 K, TDR reveals a rich spectrum of frequency-dependent level crossings from thermally populated excited states which cannot be observed by conventional static magnetometry techniques. The last study presented uses TDR in pulsed fields to determine the temperature-dependent upper-critical field Hc2 to investigate the effects of columnar defects arising from heavy ion irradiation of SrFe2(As 1--xPx)2. Results suggest irradiation uniformly suppresses Tc and Hc2, and does not introduce additional features on H c2(T) and the shapes of the anisotropic Hc2 curves indicates a nodal superconducting gap. The second technique is nuclear magnetic resonance (NMR) which yields site specific magnetic and electronic information arising from hyperfine interactions for select magnetic nuclei. NMR spectra and nuclear spin-lattice relaxation measurements are reported

  16. (31)P NMR of apicomplexans and the effects of risedronate on Cryptosporidium parvum growth.

    Science.gov (United States)

    Moreno, B; Bailey, B N; Luo, S; Martin, M B; Kuhlenschmidt, M; Moreno, S N; Docampo, R; Oldfield, E

    2001-06-15

    High-resolution 303.6 MHz (31)P NMR spectra have been obtained of perchloric acid extracts of Plasmodium berghei trophozoites, Toxoplasma gondii tachyzoites, and Cryptosporidium parvum oocysts. Essentially complete resonance assignments have been made based on chemical shifts and by coaddition of authentic reference compounds. Signals corresponding to inorganic pyrophosphate were detected in all three species. In T. gondii and C. parvum, additional resonances were observed corresponding to linear triphosphate as well as longer chain polyphosphates. Spectra of P. berghei and T. gondii also indicated the presence of phosphomonoesters and nucleotide phosphates. We also report that the pyrophosphate analog drug, risedronate (used in bone resorption therapy), inhibits the growth of C. parvum in a mouse xenograft model. When taken together, our results indicate that all the major disease-causing apicomplexan parasites contain extensive stores of condensed phosphates and that as with Plasmodium falciparum and T. gondii, the pyrophosphate analog drug risedronate is an inhibitor of C. parvum cell growth.

  17. Effects of anoxia on 31P NMR spectra of Phycomyces blakesleeanus during development

    Directory of Open Access Journals (Sweden)

    Stanić Marina

    2009-01-01

    Full Text Available The method of 31P NMR spectroscopy was used to investigate the effects of anoxia on Phycomyces blakesleea­nus mycelium during development. The greatest changes were recorded in the PPc, NADH, and α-ATP signals. Decrease of PPc signal intensity is due to chain length reduction and reduction in number of PPn molecules. Smaller decrease of β-ATP compared to α-ATP signal intensity can be attributed to maintenance of ATP concentration at the expense of PPn hydrolysis. Sensitivity to anoxia varies with the growth stage. It is greatest in 32-h and 44-h mycelium, in which PPn is used as an additional energy source, while the smallest effect was noted for 36-h fungi.

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

    Science.gov (United States)

    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.

  19. 31P NMR Studies on the Ligand Dissociation of Trinuclear Molybde-num Cluster Compounds

    Institute of Scientific and Technical Information of China (English)

    李兆基; 覃业燕; 姚元根; 唐艳红; 康遥; 夏继波; 陈忠; 吴棱

    2003-01-01

    A series of carboxylate-substituted trinudear molybdenum dus-ter compounds formulated as Mo3S4(DTP)3(RCO2)(L), where RffiH, CH3, C2H5, CH2Cl, CCl3, R1C6H4(R1 is the group on the benzene ring of aromatic carboxylate ), L=pyridine,CH3CN, DMF, have been synthesized by the ligand substitu-tion reaction. The dissociation of the loosely-coordinated ligand L from the cluster core was studied by 31p NMR. The dissocia-tion process of L is related to the solvent, temperature, and acidity of carboxylate groups, so as to affect the solution struc-ture and reactive properties of the duster. The long-distance in-teraction between ligands RCO2 and L is transported by Mo3S4 core.

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

    Science.gov (United States)

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

    2015-03-04

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