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Sample records for 1h nuclear magnetic

  1. 1H and 31P nuclear magnetic resonance spectroscopy of erythrocyte extracts in myotonic muscular dystrophy

    Extracts freshly prepared from erythrocytes of patients with myotonic muscular dystrophy, their unaffected siblings, and normal control subjects were examined with both 1H and 31P nuclear magnetic resonance spectroscopy. A moderate variability was found in the relative amounts of various nonphosphorylated compounds among patients and control subjects; however, no significant differences were found between the groups. As for the phosphorylated compounds, the sum of ADP+ATP was found significantly elevated in the myotonic muscular dystrophy patients

  2. A sup 1 H nuclear magnetic resonance study of structural and organisational changes in the cell

    Tunnah, S K

    2000-01-01

    Increasing importance is being placed on understanding the role of membrane lipids in many different areas of biochemistry. It is of interest to determine what interactions may occur between membrane lipids and drug species. Furthermore, an increasing body of evidence suggests that membrane lipids are involved in the pathology of numerous diseases such as rheumatoid arthritis, cancer and HIV. Clearly, the more information available on the mechanisms involved in diseases, the greater the potential for identifying a cure or even a prevention. sup 1 H nuclear magnetic resonance (NMR) spectroscopy was used to study the alterations in membrane lipid organisation and structure in intact, viable cultured cells. Changes in the sup 1 H NMR spectra and the spin-lattice relaxation measurements of the human K562 and the rat FRTL-5 cell lines were observed on the addition of the fatty acid species: triolein, evening primrose oil, arachidonic acid and ITF 1779. Results indicate that the membrane lipids are reorganised to a...

  3. Serum metabolic signature of minimal hepatic encephalopathy by (1)H-nuclear magnetic resonance.

    Jiménez, Beatriz; Montoliu, Carmina; MacIntyre, David A; Serra, Miguel A; Wassel, Abdallah; Jover, María; Romero-Gomez, Manuel; Rodrigo, Jose M; Pineda-Lucena, Antonio; Felipo, Vicente

    2010-10-01

    Minimal hepatic encephalopathy (MHE) reduces quality of life of cirrhotic patients, predicts overt hepatic encephalopathy, and is associated with poor prognosis. We hypothesized that MHE arises once metabolic alterations derived from the liver reach a particular threshold. Our aim was to assess whether metabolic profiling of serum samples by high-field (1)H-nuclear magnetic resonance spectroscopy ((1)H NMR) and subsequent multivariate analyses would be useful to characterize metabolic perturbations associated with MHE and to identify potential metabolic biomarkers. Metabolic serum profiles from controls (n = 69) and cirrhotic patients without MHE (n = 62) and with MHE (n = 39) were acquired using high field NMR. Supervised modeling of the data provided perfect discrimination between healthy controls and cirrhotic patients and allowed the generation of a predictive model displaying strong discrimination between patients with and without MHE (R(2)Y = 0.68, Q(2)Y = 0.63). MHE patients displayed increased serum concentrations of glucose, lactate, methionine, TMAO, and glycerol, as well as decreased levels of choline, branch amino acids, alanine, glycine, acetoacetate, NAC, and lipid moieties. Serum metabonomics by (1)H NMR offers a useful approach for characterizing underlying metabolic differences between patients with and without MHE. This procedure shows great potential as a diagnostic tool of MHE as it objectively reflects measurable biochemical differences between the patient groups and may facilitate monitoring of both disease progression and effects of therapeutic treatments. PMID:20690770

  4. A 1H nuclear magnetic resonance study of structural and organisational changes in the cell

    Increasing importance is being placed on understanding the role of membrane lipids in many different areas of biochemistry. It is of interest to determine what interactions may occur between membrane lipids and drug species. Furthermore, an increasing body of evidence suggests that membrane lipids are involved in the pathology of numerous diseases such as rheumatoid arthritis, cancer and HIV. Clearly, the more information available on the mechanisms involved in diseases, the greater the potential for identifying a cure or even a prevention. 1H nuclear magnetic resonance (NMR) spectroscopy was used to study the alterations in membrane lipid organisation and structure in intact, viable cultured cells. Changes in the 1H NMR spectra and the spin-lattice relaxation measurements of the human K562 and the rat FRTL-5 cell lines were observed on the addition of the fatty acid species: triolein, evening primrose oil, arachidonic acid and ITF 1779. Results indicate that the membrane lipids are reorganised to accommodate the interpolation of these molecules. The spatial arrangement adopted by each of these species appeared to dictate its effect on the lipids. Doxorubicin and menadione, both known to cause oxidative stress, were added to K562 cells. Although both agents are known to act by different mechanisms, the NMR data and scanning electron microscopy suggested that both caused similar alterations in the membrane organisation and lipid fluidity. Protrusions were formed indicating areas of weakness in the membrane. Spin-echo NMR was employed to investigate the action of the thiol-containing compounds, penicillamine, captopril and N-acetylcysteine in erythrocytes under conditions of oxidative stress. Results indicate that while captopril acts as a free radical scavenger, penicillamine may act as either oxidant or reductant. N-acetylcysteine was observed to act as a reducing agent. (author)

  5. Purity Assessment of Aryltetralin Lactone Lignans by Quantitative 1H Nuclear Magnetic Resonance

    Yan-Jun Sun

    2015-05-01

    Full Text Available In the present work, a quantitative 1H Nuclear Magnetic Resonance (qHNMR was established for purity assessment of six aryltetralin lactone lignans. The validation of the method was carried out, including specificity, selectivity, linearity, accuracy, precision, and robustness. Several experimental parameters were optimized, including relaxation delay (D1, scan numbers (NS, and pulse angle. 1,4-Dinitrobenzene was used as internal standard (IS, and deuterated dimethyl sulfoxide (DMSO-d6 as the NMR solvent. The purities were calculated by the area ratios of H-2,6 from target analytes vs. aromatic protons from IS. Six aryltetralin lactone lignans (deoxypodophyllotoxin, podophyllotoxin, 4-demethylpodophyllotoxin, podophyllotoxin-7′-O-β-d-glucopyranoside, 4-demethylpodophyllotoxin-7′-O-β-d-glucopyranoside, and 6′′-acetyl-podophyllotoxin-7′-O-β -d-glucopyranoside were analyzed. The analytic results of qHNMR were further validated by high performance liquid chromatography (HPLC. Therefore, the qHNMR method was a rapid, accurate, reliable tool for monitoring the purity of aryltetralin lactone lignans.

  6. Interleaved localized 1H/31P nuclear magnetic resonance spectroscopy of skeletal muscle

    Nuclear magnetic resonance (NMR) has been used as a spectroscopic method in physics and chemistry before it was developed to become a diagnostic imaging tool in medicine. When NMR spectroscopy is applied to human tissue, metabolism can be studied in normal physiological and pathological states in vivo. Metabolite concentrations and rates can be monitored dynamically and with localization of a defined region of interest. The 'window' which is opened for observation, i.e. which quantities are measured, depends on the nucleus used for RF excitation. Mechanisms of adenosine tri-phosphate (ATP) resynthesis, as a direct source of energy for muscle contraction, are phosphocreatine (PCr) splitting, glycolysis, beta-oxidation and, finally, oxidative phosphorylation. Whilst the dependency of these processes' fractional contribution to muscular energy supply on exercise type and duration is well known, quantitative models of the regulating mechanisms involved are still subject of current research. A large fraction of the established knowledge about metabolism is based on biochemical analysis of tissue acquired invasively (e.g. microdialysis and open-flow microperfusion) or representing averaged metabolic concentrations for the whole body (via serum metabolites or gas exchange analysis). Localized NMR spectroscopy, however, is capable of non-invasively acquiring time-resolved data from a defined volume of interest, in vivo. In contrast to the vast majority of MRS studies investigating metabolism, where spectra of a single nucleus (commonly 1H, 31P or 13C) were acquired or several MR spectra with different nuclei were measured in separate experiments, this work opens an additional 'window' on muscle metabolism by interleaved localized acquisition of 1H and 31P NMR spectra from human calf muscle in vivo, during rest, exercise and recovery, in a single experiment. Using this technique, the time courses of the concentrations of phosphocreatine, inorganic phosphate (Pi), ATP, total

  7. A sample preparation protocol for 1H nuclear magnetic resonance studies of water-soluble metabolites in blood and urine.

    Sheedy, John R; Ebeling, Peter R; Gooley, Paul R; McConville, Malcolm J

    2010-03-15

    We describe a general protocol for preparing protein-containing biofluids for (1)H nuclear magnetic resonance (NMR) metabolomic studies. In this protocol, untreated samples are diluted in deuterated solvents to precipitate proteins and recover metabolites quantitated relative to standard reference compounds such as 3-trimethylsilylpropionic acid (TSP) and 2,2-dimethyl-2-silapentane-5-sulfonic acid (DSS). The efficacy of this protocol was tested using a bovine serum albumin/metabolite mix and human serum samples. This sample preparation method can be readily applied to any protein-containing biofluid for (1)H NMR studies. PMID:19941831

  8. Application of cryoprobe 1H nuclear magnetic resonance spectroscopy and multivariate analysis for the verification of corsican honey.

    Donarski, James A; Jones, Stephen A; Charlton, Adrian J

    2008-07-23

    Proton nuclear magnetic resonance spectroscopy ((1)H NMR) and multivariate analysis techniques have been used to classify honey into two groups by geographical origin. Honey from Corsica (Miel de Corse) was used as an example of a protected designation of origin product. Mathematical models were constructed to determine the feasibility of distinguishing between honey from Corsica and that from other geographical locations in Europe, using (1)H NMR spectroscopy. Honey from 10 different regions within five countries was analyzed. (1)H NMR spectra were used as input variables for projection to latent structures (PLS) followed by linear discriminant analysis (LDA) and genetic programming (GP). Models were generated using three methods, PLS-LDA, two-stage GP, and a combination of PLS and GP (PLS-GP). The PLS-GP model used variables selected by PLS for subsequent GP calculations. All models were generated using Venetian blind cross-validation. Overall classification rates for the discrimination of Corsican and non-Corsican honey of 75.8, 94.5, and 96.2% were determined using PLS-LDA, two-stage GP, and PLS-GP, respectively. The variables utilized by PLS-GP were related to their (1)H NMR chemical shifts, and this led to the identification of trigonelline in honey for the first time. PMID:18564849

  9. Investigation of stroke in sickle cell disease by 1H nuclear magnetic resonance spectroscopy

    Localized proton nuclear magnetic resonance spectroscopy (MRS), obtained with stimulated echo and spin echo sequences, MR imaging (MRI) and MR angiography (MRA) were used to study the brain in 13 children and adolescents with sickle cell disease. Regions of interest (ROI) studied by MRS included regions appearing normal on MRI as well as regions showing complications of sickle cell disease, including focal deep white matter areas of high signal intensity (deep white matter ischemia, DWMI) seen on long TR images, focal atropic brain areas, and infarcts. The findings in these studies are summarized as follows: Normal-appearing regions on MRI have normal MRS. In ROI including small areas of DWMI, lactate elevation was not detected, but the levels of N-acetyl-aspartate (NAA) appeared slightly elevated. In areas of DWMI 1-2 cm in size, reduced blood flow could be seen on MRA and lactate elevation could be detected with MRS. When blood flow to a DWMI region was normal, NAA was reduced and there was little lactate elevation, as cell death had already occurred. ROI consisting of atrophic tissue had reduced NAA levels but total creatine levels were not changed. Sometimes lipids, presumably from broken cell membrane, could be detected. In regions of past massive stroke, all metabolites were absent except for small amounts of lactate or lipids. (orig.)

  10. Establishing 1H nuclear magnetic resonance based metabonomics fingerprinting profile for spinal cord injury: a pilot study

    JIANG Hua; PENG Jin; ZHOU Zhi-yuan; DUAN Yu; CHEN Wei; CAI Bin; YANG Hao; ZHANG Wei

    2010-01-01

    Background Spinal cord injury (SCI) is a complex trauma that consists of multiple pathological mechanisms involving cytotoxic, oxidation stress and immune-endocrine. This study aimed to establish plasma metabonomics fingerprinting atlas for SCI using 1H nuclear magnetic resonance (NMR) based metabonomics methodology and principal component analysis techniques.Methods Nine Sprague-Dawley (SD) male rats were randomly divided into SCI, normal and sham-operation control groups. Plasma samples were collected for 1H NMR spectroscopy 3 days after operation. The NMR data were analyzed using principal component analysis technique with Matlab software.Results Metabonomics analysis was able to distinguish the three groups (SCI, normal control, sham-operation). The fingerprinting atlas indicated that, compared with those without SCI, the SCI group demonstrated the following characteristics with regard to second principal component: it is made up of fatty acids, myc-inositol, arginine, very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), triglyceride (TG), glucose, and 3-methyl-histamine.Conclusions The data indicated that SCI results in several significant changes in plasma metabolism early on and that a metabonomics approach based on 1H NMR spectroscopy can provide a metabolic profile comprising several metabolite classes and allow for relative quantification of such changes. The results also provided support for further development and application of metabonomics technologies for studying SCI and for the utilization of multivariate models for classifying the extent of trauma within an individual.

  11. 1H Nuclear Magnetic Resonance Relaxometry Study of Water State in Milk Protein Mixtures

    Le Dean, A.; Mariette, F.; Marin, M

    2004-01-01

    1H NMR signal was used to characterize highly hydrated milk protein dispersions (3-20% dry matter) with various micellar casein concentrations (3-15%), whey protein concentrations (0-3%), lactose concentrations (0-7.5%), CaCl2 concentrations (0-2 mM), and pH (6.2-6.6). The results showed the predominant effect of micellar casein concentration on water state and were consistent with the three-site relaxation model in the absence of lactose. The relaxation rates observed for these dispersions w...

  12. Stereoelectronic effects on 1H nuclear magnetic resonance chemical shifts in methoxybenzenes

    Lambert, Maja; Olsen, Lars; Jaroszewski, Jerzy W

    2006-01-01

    differences are due to different conformational behavior of the OH and OCH3 groups; while the ortho-disubstituted OH group remains planar in polyphenols due to hydrogen bonding and conjugative stabilization, the steric congestion in ortho-disubstituted anisoles outweighs the conjugative effects and forces the......Investigation of all O-methyl ethers of 1,2,3-benzenetriol and 4-methyl-1,2,3-benzenetriol (3-16) by 1H NMR spectroscopy and density-functional calculations disclosed practically useful conformational effects on 1H NMR chemical shifts in the aromatic ring. While the conversion of phenol (2) to...... Ar-OCH3 torsion out of the ring plane, resulting in large stereoelectronic effects on the chemical shift of Hpara. Conformational searches and geometry optimizations for 3-16 at the B3LYP/6-31G** level, followed by B3LYP/6-311++G(2d,2p) calculations for all low-energy conformers, gave excellent...

  13. 1H and 19F nuclear magnetic resonance microimaging of water and chemical distribution in soil columns.

    Simpson, Myrna J; Simpson, André J; Gross, Dieter; Spraul, Manfred; Kingery, William L

    2007-07-01

    Nuclear magnetic resonance (NMR) microimaging is a noninvasive and nondestructive technique that has great potential for the study of soil processes. Hydrogen-1 NMR microimaging techniques were used to examine the distribution of water in four different soil cores. Fluorine-19 NMR microimaging is also used to study the transport of three model contaminants (hexafluorobenzene, sodium fluoride, and trifluralin) in soil columns. The 1H water distribution studies demonstrate that NMR microimaging can provide unique detail regarding the nature and location of water in soils. Image distortion (magnetic susceptibility) was observed for soil samples low in water (20-28% by weight) and that contained an iron content of 0.73 to 0.99%. Highly resolved images were obtained for the organic-rich soil (Croatan sample) and also facilitated the analysis of bound and unbound soil water through varying spin echo times. The contaminant studies with 19F NMR demonstrated that preferential flow processes can be observed in soil cores in as little as 16 h. Studies with hexafluorobenzene produced the highest quality images whereas the definition decreased over time with both trifluralin and sodium fluoride as the compounds penetrated the soil. Nonetheless, both 1H and 19F NMR microimaging techniques demonstrate great promise for studying soil processes. PMID:17665672

  14. (1)H-Nuclear Magnetic Resonance-Based Plasma Metabolic Profiling of Dairy Cows with Fatty Liver.

    Xu, Chuang; Sun, Ling-Wei; Xia, Cheng; Zhang, Hong-You; Zheng, Jia-San; Wang, Jun-Song

    2016-02-01

    Fatty liver is a common metabolic disorder of dairy cows during the transition period. Historically, the diagnosis of fatty liver has involved liver biopsy, biochemical or histological examination of liver specimens, and ultrasonographic imaging of the liver. However, more convenient and noninvasive methods would be beneficial for the diagnosis of fatty liver in dairy cows. The plasma metabolic profiles of dairy cows with fatty liver and normal (control) cows were investigated to identify new biomarkers using (1)H nuclear magnetic resonance. Compared with the control group, the primary differences in the fatty liver group included increases in β-hydroxybutyric acid, acetone, glycine, valine, trimethylamine-N-oxide, citrulline, and isobutyrate, and decreases in alanine, asparagine, glucose, γ-aminobutyric acid glycerol, and creatinine. This analysis revealed a global profile of endogenous metabolites, which may present potential biomarkers for the diagnosis of fatty liver in dairy cows. PMID:26732447

  15. 1H Nuclear Magnetic Resonance (NMR) metabonomic study of breast cancer in Indian population

    Breast cancer is the most common cancer diagnosed in women worldwide with over 1.3 million new cases per year. Recently it has been observed that breast cancer is increasing very rapidly in low income countries including India. Lipids not only play very important and vital role of prime structural component in human body they are also important functional components in cellular metabolism. Transformation from benign to malignant tissue involves several biochemical processes and understanding these processes provides very useful insight related to cancer prognosis. Thus study of lipids becomes very important and NMR spectroscopy is one of the techniques which can be utilized to identifying all lipid components simultaneously. The tissue specimens (35, benign 20 and malignant 15; patient age group 47 yrs) were collected after breast surgeries and were snap frozen in liquid nitrogen. Part of all tissues was sent for routine histopathology. Lipid extraction was performed by Folch method (Folch, 1957) using cholesterol and methanol (2:1 ratio). The NMR spectra of the extracted lipids were recorded immediately after the sample preparation. All NMR experiments were performed on a Bruker Avance 800 MHz spectrometer. 1H NMR analysis of lipid extract of breast tissue in Indian population shows there is significant elevation of phosphotidycholine, plasmalogen and esterified cholesterol with decrease in triacylglycerol in cancer breast compared to benign tissue implying that their metabolism is definitely altered during carcinogenesis. This study analyzes the role of NMR as an additional diagnostic tool on the basis of examination of lipid extract. (author)

  16. ~1H nuclear magnetic resonance-based metabolomics reveals sex-specific metabolic changes of gastrodin intervention in rats

    Xin; Li; Yuan-Wei; Jia; Jun-Song; Wang; Ming-Hua; Yang; Kelvin; D.G.Wang; Ling-Yi; Kong

    2014-01-01

    Objective:To explore~1H nuclear magnetic resonance-based metabolomics on sex-specific metabolic changes of gastrodin intervention in rats.Methods:In this research,~1H NMR-based metabolomics was used for the first time to investigate metabolic changes following chronic intervention with gastrodin in rats.Results:24 endogenous metabolites were identified.Body weight.daily diet and the total volume of urine in in each day of each rat were measured synchronously.Modifications in 12 metabolites were observsd following gastrodin intervention,indicating gastrodin-induced alterations in carbohydrate and energy metabolism.Interestingly,these metabolic changes were not totally identical in female and male rats.Some metabolic changes arising from gastrodin intervention showed sexual dimorphism including LDL/VLDL and lactate which were on the decrease in the female but on the increase in the male,together with arginine/ornithine,creatine,and glycerol which were on the increase in the female but on the decrease in the male.While the decrease in pyruvate,succinate and glutamate was only shown in the male and the increase in valine,α-ketoglutarate and glucose was only in the female.Conclusions:This resesrch shows the sex-specific metabolic response to GAS intervention,weather GAS is a healthy dietary supplement for the male merits further investigation

  17. 1H nuclear magnetic resonance-based metabolomics reveals sex-specific metabolic changes of gastrodin intervention in rats

    Xin Li; Yuan-Wei Jia; Jun-Song Wang; Ming-Hua Yang; Kelvin D G Wang; Ling-Yi Kong

    2014-01-01

    Objective:To explore1H nuclear magnetic resonance-based metabolomics on sex-specific metabolic changes of gastrodin intervention in rats.Methods:In this research,1HNMR-based metabolomics was used for the first time to investigate metabolic changes following chronic intervention with gastrodin in rats.Results:24 endogenous metabolites were identified.Body weight, daily diet and the total volume of urine in in each day of each rat were measured synchronously.Modifications in12 metabolites were observed following gastrodin intervention, indicating gastrodin-induced alterations in carbohydrate and energy metabolism.Interestingly, these metabolic changes were not totally identical in female and male rats.Some metabolic changes arising from gastrodin intervention showed sexual dimorphism includingLDL/VLDL and lactate which were on the decrease in the female but on the increase in the male, together with arginine/ornithine, creatine, and glycerol which were on the increase in the female but on the decrease in the male.While the decrease in pyruvate, succinate and glutamate was only shown in the male and the increase in valine,α-ketoglutarate, glycine and glucose was only in the female. Conclusions:This research shows the sex-specific metabolic response toGAS intervention, weatherGAS is a healthy dietary supplement for the male merits further investigation.

  18. Metabolic Alterations of the Zebrafish Brain after Acute Alcohol Treatment by 1H Nuclear Magnetic Resonance Spectroscopy

    Dong-Cheol Woo

    2013-01-01

    Full Text Available The purpose of this study is to investigate the metabolic alterations associated with acute alcohol treatment in zebrafish by 1H nuclear magnetic resonance spectroscopy (NMRS. The brain metabolism of zebrafish was investigated after acute alcohol treatment (one-hour long exposure of adult fish to 0.00%, 0.25%, 0.50%, or 1.00% ethyl alcohol with whole brain extraction. The results of this study showed that glutamate (Glu was significantly decreased, scyllo-inositol (sIns showed a small apparent increase only in the highest acute treatment dose group, and myoinositol (mIns showed a significant decrease. [Glu]/[tCr] and [mIns]/[tCr] levels were significantly reduced regardless of the alcohol dose, and [sIns]/[tCr] was increased in the highest alcohol treatment dose group. The present NMR study revealed that specific metabolites, such as Glu and mIns, were substantially decreased in case of acute alcohol exposed zebrafish brain.

  19. Early Biomarkers in 1H Nuclear Magnetic Resonance Spectroscopy of Striatal Pathological Mechanisms after Acute Carbon Monoxide Poisoning in Rats

    GUAN Li; LI Zong Yang; ZHANG Yan Lin; CONG Cui Cui; ZHAO Jin Yuan

    2015-01-01

    Objective In vivo Proton Magnetic Resonance Spectroscopy (1H-MRS) can be used to evaluate the levels of specific neurochemical biomarkers of pathological mechanisms in the brain. Methods We conducted T2-Weighted Magnetic Resonance Imaging (MRI) and 1H-MRS with a 3.0-Tesla animal MRI system to investigate the early microstructural and metabolic profiles in vivo in the striatum of rats following carbon monoxide (CO) poisoning. Results Compared to baseline, we found significant cortical surface deformation, cerebral edema changes, which were indicated by the unclear gray/white matter border, and lateral ventricular volume changes in the brain. A significant reduction in the metabolite to total creatine (Cr) ratios of N-acetylaspartate (NAA) was observed as early as 1 h after the last CO administration, while the lactate (Lac) levels increased marginally. Both the Lac/Cr and NAA/Cr ratios leveled off at 6 h and showed no subsequent significant changes. In addition, compared to the control, the choline (Cho)/Cr ratio was slightly reduced in the early stages and significantly increased after 6 h. In addition, a pathological examination revealed mild cerebral edema on cessation of the insult and more severe cerebral injury after additional CO poisoning. Conclusion The present study demonstrated that 1H-MRS of the brain identified early metabolic changes after CO poisoning. Notably, the relationship between the increased Cho/Cr ratio in the striatum and delayed neuropsychologic sequelae requires further research.

  20. Conformational requirement of signal sequences functioning in yeast: Circular dichroism and 1H nuclear magnetic resonance studies of synthetic peptides

    Recently, the authors have designed a series of simplified artificial signal sequences and have shown that a proline residue in the signal sequence plays an important role in the secretion of human lysozyme in yeast, presumably by altering the conformation of the signal sequence. To elucidate the conformational requirement of the signal sequence in more detail, functional and nonfunctional signal sequences connected to the N-terminal five residues of mature human lysozyme were chemically synthesized and their conformations in a lipophilic environment analyzed by circular dichroism (CD) and 1H nuclear magnetic resonance (NMR) spectroscopy. The helix content of the peptides, including functional (L8, CL10) and nonfunctional (L8PL, L8PG, L8PL2) signal sequences, was estimated from CD spectra to be 40-50% and 60-70%, respectively, indicating that the helical structure is more abundant in the nonfunctional signal sequences. Two-dimensional NMR analyses in 50% TFE/H2O revealed that each peptide adopted a helical conformation throughout the sequence except for a few residues at the N- and C-termini. Furthermore, H-D exchange experiments indicated that the helical structure of the C-terminal region of the functional signal sequences (L8 and CL10) was less stable than that of the nonfunctional signal sequences (L8PL and L8PL2). On the basis of these results, a model was developed in which the functional signal sequence is inserted in the membrane with a helical conformation and the C-terminal helix unraveled in an extended conformational form through an interaction with the signal peptidase

  1. Metabolic profiles using (1)H-nuclear magnetic resonance spectroscopy in postpartum dairy cows with ovarian inactivity.

    Xu, Chuchu; Xia, Cheng; Sun, Yuhang; Xiao, Xinhuan; Wang, Gang; Fan, Ziling; Shu, Shi; Zhang, Hongyou; Xu, Chuang; Yang, Wei

    2016-10-01

    To understand the differences in metabolic changes between cows with ovarian inactivity and estrus cows, we selected cows at 60-90 days postpartum from an intensive dairy farm. According to clinical manifestations, B-ultrasound scan, rectal examination, 10 cows were assigned to the estrus group (A) and 10 to the ovarian inactivity group (B). All plasma samples were analyzed by (1)H-nuclear magnetic resonance spectroscopy to compare plasma metabolomic profiles between the groups. We used multivariate pattern recognition to screen for different metabolites in plasma of anestrus cows. Compared with normal estrous cows, there were abnormalities in 12 kinds of metabolites in postpartum cows with ovarian inactivity (|r|> 0.602), including an increase in acetic acid (r = -0.817), citric acid (r = -0.767), and tyrosine (r = -0.714), and a decrease in low-density lipoprotein (r = 0.820), very low-density lipoprotein (r = 0.828), lipids (r = 0.769), alanine (r = 0.816), pyruvate (r = 0.721), creatine (r = 0.801), choline (r = 0.639), phosphorylcholine (r = 0.741), and glycerophosphorylcholine (r = 0.881). These metabolites were closely related to abnormality of glucose, amino acid, lipoprotein and choline metabolism, which may disturb the normal estrus. The decrease in plasma creatine and the increase in tyrosine were new changes for ovarian inactivity of postpartum cows. The decrease in plasma creatine and choline and the increase in tyrosine and p-hydroxyphenylalanine in cows with ovarian inactivity provide new directions for research on the mechanism of ovarian inactivity in cows. PMID:27291083

  2. High-speed magic angle spinning solid-state 1H nuclear magnetic resonance study of the conformation of gramicidin A in lipid bilayers.

    Bouchard, M.; Davis, J H; Auger, M.

    1995-01-01

    One- and two-dimensional solid-state 1H nuclear magnetic resonance spectra of gramicidin A incorporated in a dimyristoylphosphatidylcholine membrane have been obtained with use of high-speed magic angle spinning. By rotating the sample at 13 kHz, it is possible to observe signals in the 1H spectra between 6.0 and 9.0 ppm attributable to the aromatic protons of the tryptophan residues and the formyl group proton of gramicidin A. Two-dimensional solid-state COSY spectra provided information for...

  3. 1H nuclear magnetic resonance spectroscopy-based metabonomic study in patients with cirrhosis and hepatic encephalopathy

    Dabos, Konstantinos John; Parkinson, John Andrew; Sadler, Ian Howard; Plevris, John Nicholas; Hayes, Peter Clive

    2015-01-01

    AIM: To identify plasma metabolites used as biomarkers in order to distinguish cirrhotics from controls and encephalopathics. METHODS: A clinical study involving stable cirrhotic patients with and without overt hepatic encephalopathy was designed. A control group of healthy volunteers was used. Plasma from those patients was analysed using 1H - nuclear magnetic resonance spectroscopy. We used the Carr Purcell Meiboom Gill sequence to process the sample spectra at ambient probe temperature. We used a gated secondary irradiation field for water signal suppression. Samples were calibrated and referenced using the sodium trimethyl silyl propionate peak at 0.00 ppm. For each sample 128 transients (FID’s) were acquired into 32 K complex data points over a spectral width of 6 KHz. 30 degree pulses were applied with an acquisition time of 4.0 s in order to achieve better resolution, followed by a recovery delay of 12 s, to allow for complete relaxation and recovery of the magnetisation. A metabolic profile was created for stable cirrhotic patients without signs of overt hepatic encephalopathy and encephalopathic patients as well as healthy controls. Stepwise discriminant analysis was then used and discriminant factors were created to differentiate between the three groups. RESULTS: Eighteen stabled cirrhotic patients, eighteen patients with overt hepatic encephalopathy and seventeen healthy volunteers were recruited. Patients with cirrhosis had significantly impaired ketone body metabolism, urea synthesis and gluconeogenesis. This was demonstrated by higher concentrations of acetoacetate (0.23 ± 0.02 vs 0.05 ± 0.00, P < 0.01), and b-hydroxybutarate (0.58 ± 0.14 vs 0.08 ± 0.00, P < 0.01), lower concentrations of glutamine (0.44 ± 0.08 vs 0.63 ± 0.03, P < 0.05), histidine (0.16 ± 0.01 vs 0.36 ± 0.04, P < 0.01) and arginine (0.08 ± 0.01 vs 0.14 ± 0.02, P < 0.03) and higher concentrations of glutamate (1.36 ± 0.25 vs 0.58 ± 0.04, P < 0.01), lactate (1.53 ± 0

  4. Quantitative analysis of retinol and retinol palmitate in vitamin tablets using 1H-nuclear magnetic resonance spectroscopy

    1H-NMR spectrometry was applied to the quantitative analysis of Vitamin A in four different types of vitamin tablets without any chromatographic purification or saponification. The experiment was performed analysing the H-15 resonance, which appears at δ 4.32 for retinol and δ 4.69 for retinol palmitate, well separated from other resonances in the 1H-NMR spectrum. Compounds were quantified using the relative ratio of the integral of the H-15 signal to that of a known amount of internal standard (200 μg/ml), anthracene. In order to evaluate the feasibility of avoiding the saponification of retinol palmitate in the preparation of samples, several solvents such as dimethylsulfoxide, n-hexane, methanol, water, and 0.1 M of HCl were tested as possible extraction solvents. Among these, dimethylsulfoxide showed the best yield of retinol palmitate. This method, using dimethylsulfoxide extraction and 1H-NMR, allows rapid and simple quantitation of retinol palmitate in tablets avoiding tedious saponification

  5. Artificial neural networks for classification in metabolomic studies of whole cells using 1H nuclear magnetic resonance.

    Brougham, D F

    2011-01-01

    We report the successful classification, by artificial neural networks (ANNs), of (1)H NMR spectroscopic data recorded on whole-cell culture samples of four different lung carcinoma cell lines, which display different drug resistance patterns. The robustness of the approach was demonstrated by its ability to classify the cell line correctly in 100% of cases, despite the demonstrated presence of operator-induced sources of variation, and irrespective of which spectra are used for training and for validation. The study demonstrates the potential of ANN for lung carcinoma classification in realistic situations.

  6. 1H-Nuclear Magnetic Resonance Analysis of the Triacylglyceride Composition of Cold-Pressed Oil from Camellia japonica

    Salinero, Carmen; Feás, Xesús; Mansilla, J. Pedro; Seijas, Julio A.; Vázquez-Tato, M. Pilar; Vela, Pilar; Sainz, María J.

    2012-01-01

    Camellia japonica (CJ) has oil-rich seeds, but the study of these oils has received little attention and has mainly focused only on their health properties. In the present work the relative composition of the fatty acid (FA) components of the triglycerides in cold-pressed oil from CJ is studied by 1H-NMR. The results obtained were: 75.75%, 6.0%, 0.17% and 18.67%, for oleic, linoleic, linolenic and saturated FA respectively. Levels of C18 unsaturated FA found in CJ oil were similar to those re...

  7. Detection and quantification of phenolic compounds in olive oil by high resolution 1H nuclear magnetic resonance spectroscopy

    High resolution 1H NMR spectroscopy has been employed as a versatile and rapid method to analyze the polar fraction of extra virgin olive oils containing various classes of phenolic compounds. The strategy for identification of phenolic compounds is based on the NMR chemical shifts of a large number of model compounds assigned by using two-dimensional (2D) NMR spectroscopy. Furthermore, 2D NMR was applied to phenolic extracts in an attempt to discover additional phenolic compounds. The 1H NMR methodology was successful in detecting simple phenols, such as p-coumaric acid, vanillic acid, homovanillyl alcohol, vanillin, free tyrosol, and free hydroxytyrosol, the flavonols apigenin and luteolin, the lignans (+) pinoresinol, (+) 1-acetoxypinoresinol and syringaresinol, two isomers of the aldehydic form of oleuropein and ligstroside, the dialdehydic form of oleuropein and ligstroside lacking a carboxymethyl group, and finally total hydroxytyrosol and total tyrosol reflecting the total amounts of free and esterified hydroxytyrol and tyrosol, respectively. The absolute amount of each phenolic constituent was determined in the polar fraction by using anhydrous 1,3,5-triazine as an internal standard

  8. Detection and quantification of phenolic compounds in olive oil by high resolution {sup 1}H nuclear magnetic resonance spectroscopy

    Christophoridou, Stella [NMR Laboratory, Department of Chemistry, University of Crete, P.O. Box 2208, Voutes, 71003 Heraklion, Crete (Greece); Dais, Photis [NMR Laboratory, Department of Chemistry, University of Crete, P.O. Box 2208, Voutes, 71003 Heraklion, Crete (Greece)], E-mail: dais@chemistry.uoc.gr

    2009-02-09

    High resolution {sup 1}H NMR spectroscopy has been employed as a versatile and rapid method to analyze the polar fraction of extra virgin olive oils containing various classes of phenolic compounds. The strategy for identification of phenolic compounds is based on the NMR chemical shifts of a large number of model compounds assigned by using two-dimensional (2D) NMR spectroscopy. Furthermore, 2D NMR was applied to phenolic extracts in an attempt to discover additional phenolic compounds. The {sup 1}H NMR methodology was successful in detecting simple phenols, such as p-coumaric acid, vanillic acid, homovanillyl alcohol, vanillin, free tyrosol, and free hydroxytyrosol, the flavonols apigenin and luteolin, the lignans (+) pinoresinol, (+) 1-acetoxypinoresinol and syringaresinol, two isomers of the aldehydic form of oleuropein and ligstroside, the dialdehydic form of oleuropein and ligstroside lacking a carboxymethyl group, and finally total hydroxytyrosol and total tyrosol reflecting the total amounts of free and esterified hydroxytyrol and tyrosol, respectively. The absolute amount of each phenolic constituent was determined in the polar fraction by using anhydrous 1,3,5-triazine as an internal standard.

  9. Influence of fat and phytosterols concentration in margarines on their degradation at high temperature. A study by (1)H Nuclear Magnetic Resonance.

    Sopelana, P; Ibargoitia, María L; Guillén, María D

    2016-04-15

    The objective of this work was to study the influence of several factors, especially fat and phytosterols concentration, on the behavior of margarine under thermo-oxidative conditions. For this purpose, margarines with similar compositions in acyl groups, but differing in the concentration of both fat and phytosterols, were heated at 180°C. The changes in the main components of margarine lipids and the formation of new compounds throughout the thermal treatment were monitored by (1)H Nuclear Magnetic Resonance. The results show that the presence of high concentrations of phytosterols seems to have an antioxidant effect, since it slows down the thermo-oxidation rate of margarine and, consequently, the generation rate and concentrations of secondary oxidation products such as some aldehydes, epoxides and alcohols. The oil-water ratio also seems to have an important effect on margarine behavior, in such a way that the lower the fat concentration is, the higher its thermo-oxidation rate. PMID:26675865

  10. 1H nuclear magnetic resonance study of olive oils commercially available as Italian products in the United States of America.

    Del Coco, Laura; Schena, Francesco Paolo; Fanizzi, Francesco Paolo

    2012-05-01

    Multivariate analysis of (1)H NMR data has been used for the characterization of 12 blended olive oils commercially available in the U.S. as Italian products. Chemometric methods such as unsupervised Principal Component Analysis (PCA) allowed good discrimination and gave some affinity indications for the U.S. market olive oils compared to other single cultivars of extra virgin olive oil such as Coratina and Ogliarola from Apulia, one of Italy's leading olive oil producers, Picual (Spain), Kalamata (Greece) and Sfax (Tunisia). The olive oils commercially available as Italian products in the U.S. market clustered into 3 groups. Among them only the first (7 samples) and the second group (2 samples) showed PCA ranges similar to European references. Two oils of the third group (3 samples) were more similar to Tunisian references. In conclusion, our study revealed that most EVOO (extra virgin olive oils) tested were closer to Greek (in particular) and Spanish olive oils than Apulia EVOO. The PCA loadings disclose the components responsible for the discrimination as unsaturated (oleic, linoleic, linolenic) and saturated fatty acids. All are of great importance because of their nutritional value and differential effects on the oxidative stability of oils. It is evident that this approach has the potential to reveal the origin of EVOO, although the results support the need for a larger database, including EVOO from other Italian regions. PMID:22690321

  11. A program for semi-automatic sequential resonance assignments in protein 1H nuclear magnetic resonance spectra

    Billeter, M.; Basus, V. J.; Kuntz, I. D.

    A new approach to the sequential resonance assignment of protein 1H NMR spectra based on a computer program is presented. Two main underlying concepts were used in the design of this program. First, it considers at any time all possible assignments that are consistent with the currently available data. If new information is added then assignments that have become inconsistent are eliminated. Second, the process of the assignment is split into formal steps that follow strictly from the available data and steps that involve the interpretation of ambiguous NMR data. The first kind of step is safe in the sense that it never leads to false assignments provided that the input does not contain any error; these steps are executed automatically by the program when the input files are read and whenever new data have been entered interactively. The second kind of step is left to the user: An interactive dialog provides detailed information on the current situation of the assignment and indicates what kind of new data would be most promising for further assignment. The user then provides new data to the program and restarts the automatic part which will attempt to draw logical conclusions from the joint use of the new data and the earlier available information and will eliminate assignments that have become inconsistent. Results of test problems using simulated NMR data for proteins consisting of up to 99 residues as well as the application of the program to obtain the complete assignment of α-bungarotoxin, a 74-residue snake neurotoxin, are reported.

  12. An Evaluation of 1-Deoxynojirimycin Oral Administration in Eri Silkworm through Fat Body Metabolomics Based on 1H Nuclear Magnetic Resonance

    Wen, Chao-wei; Lin, Xiao-dong; Dong, Min-jian; Deng, Ming-jie

    2016-01-01

    1-Deoxynojirimycin (DNJ), the main hypoglycemic constituent in mulberry (Morus alba) latex, has been extensively researched. Although there is considerable interest in the biological effects of DNJ, the roles of 1-deoxynojirimycin (DNJ) in glycometabolism and energy metabolism in insects have received little attention. In this paper, 1H nuclear magnetic resonance (1H NMR) based metabonomic was performed to study the effects of the oral supplementation of 0.25% DNJ, 0.5% DNJ, latex, and the mixture of 0.5% DNJ and latex (1 : 1) on the fat body glycometabolism and energy metabolism of the fourth-instar larvae of Eri silkworms, Samia cynthia ricini. Metabolic pattern recognition analysis (partial least square-discriminant analysis, PLS-DA) of fat body extracts indicated that the groups of 0.25% DNJ, 0.5% DNJ, latex, and the mixture of 0.5% DNJ and latex (1 : 1) were significantly different from the control group. Further, compared to the control group, the metabolites levels of lactate, trehalose, succinate, malate, and fumarate were remarkably changed in experimental groups, which were involved in glycolysis, hydrolysis of trehalose, and tricarboxylic acid (TCA) cycle. Our results indicate that DNJ has a positive impact on the reverse energy metabolism of Eri silkworms and metabonomic analysis based on NMR can be used as a tool to identify potential biomarkers. PMID:27294120

  13. 1H and 31P nuclear magnetic resonance investigation of the interaction between 2,3-diphosphoglycerate and human normal adult hemoglobin

    High-resolution 1H and 31P nuclear magnetic resonance spectroscopy has been used to investigate the binding of 2,3-diphosphoglycerate to human normal adult hemoglobin and the molecular interactions involved in the allosteric effect of the 2,3-diphosphoglycerate molecule on hemoglobin. Individual hydrogen ion NMR titration curves have been obtained for 22-26 histidyl residues of hemoglobin and for each phosphate group of 2,3-diphosphoglycerate with hemoglobin in both the deoxy and carbonmonoxy forms. The results indicate that 2,3-diphosphoglycerate binds to deoxyhemoglobin at the central cavity between the two β chains and the binding involves the β2-histidyl residues. Moreover, the results suggest that the binding site of 2,3-diphosphoglycerate to carbonmonoxyhemoglobin contains the same (or at least some of the same) amino acid residues responsible for binding in the deoxy form. As a result of the specific interactions with 2,3-diphosphoglycerate, the β2-histidyl residues make a significant contribution to the alkaline Bohr effect under these experimental conditions. These results give the first experimental demonstration that long-range electrostatic and/or conformation effects of the binding could play an important role in the allosteric effect of 2,3-diphosphoglycerate on hemoglobin. The 31P nuclear magnetic resonance titration data for each phosphate group of 2,3-diphosphoglycerate have been used to calculate the pK values of the phosphate groups in 2,3-diphosphoglycerate bound to deoxy- and carbon-monoxyhemoglobin and the proton uptake by 2,3-diphosphoglycerate upon ligand binding to hemoglobin

  14. Dynamics of ferroelectric bis(imidazolium) pentachloroantimonate(III) by means of nuclear magnetic resonance 1H relaxometry and dielectric spectroscopy.

    Piecha-Bisiorek, A; Jakubas, R; Medycki, W; Florek-Wojciechowska, M; Wojciechowski, M; Kruk, D

    2014-05-22

    Some of haloantimonates(III) and halobismuthates(III) are ferroelectric. Bis(imidazolium) pentachloroantimonate(III), (C3N2H5)2SbCl5 (abbreviation: ICA) is the first example of such compounds with a one-dimensional anionic chain which exhibits ferroelectric properties. The relation between the ionic dynamics and network structure and the ferroelectric features is not clear. Here Nuclear Magnetic Resonance (NMR) (1)H spin-lattice relaxation experiments at 25 MHz are reported for ICA in the temperature range of 80 K-360 K, covering ferroelectric-paraelectric and structural phase transitions of the compound occurring at 180 and 342 K, respectively. The relaxation process is biexponential in the whole temperature range indicating two dynamically nonequivalent types of imidazolium cations. Temperature dependences of both relaxation contributions allow for identifying three motional processes. Two of them are cation-specific - i.e. they are attributed to the two types of imidazolium cations, respectively. The third process involves both types of cations, and it is characterized by much lower activation energy. Moreover, the relaxation data (combined with (1)H second moment measurements) show that the ferroelectric-paraelectric phase transition mechanism is governed, to a large extent, by the anionic network arrangement. The NMR studies are complemented by dielectric spectroscopy experiments performed in the vicinity of the Curie temperature, TC = 180 K, to get insight into the mechanism of the ferroelectric-paraelectric phase transition. The dielectric dispersion data show critical slowing down of the macroscopic relaxation time, τ, in ICA when approaching TC from the paraelectric side, indicating an order-disorder type of ferroelectrics. PMID:24804840

  15. Metabolic alterations produced by 3-nitropropionic acid in rat striata and cultured astrocytes: quantitative in vitro 1H nuclear magnetic resonance spectroscopy and biochemical characterization

    Quantitative high resolution in vitro 1H nuclear magnetic resonance spectroscopy was employed to study the metabolic effects of 3-nitropropionic acid associated with aging from perchloric acid extracts of rat striata. Systemic injection of 3-nitropropionic acid in rats at a dose of 10 mg/kg/day for seven consecutive days significantly impaired energy metabolism in rats one, four and eight months of age, as evidenced by a marked elevation of succinate and lactate levels. However, a significant decrease in N-acetyl-l-aspartate level, a neuronal marker, was observed in four- and eight-month-old rats but not in one-month-old rats. This would indicate that rats at four to eight months are more susceptible to 3-nitropropionic acid than those at one month. A significant decrease in GABA level was observed in four-month-old 3-nitropropionic acid-treated rats, which is consistent with the literature that GABAergic neurons are particularly vulnerable to 3-nitropropionic acid treatment. In addition, glutamine and glutamate levels were markedly decreased at four and eight months in 3-nitropropionic acid-treated rats. Since glutamine is synthesized predominantly in glia, the observation above suggests that 3-nitropropionic acid intoxication may involve perturbation of energy metabolism, glial injury and consequent neuronal damage. Astrocytes which are essential in the metabolism of glutamate and glutamine were used to further assess 3-nitropropionic acid-induced toxicity. Glial proliferation, mitochondrial metabolism and glutamine synthetase activity were all reduced by 3-nitropropionic acid treatment with a concomitant increase, in a dose-dependent manner, of lactate levels, suggesting that 3-nitropropionic acid is also detrimental to astrocytes in vivo and thus may affect metabolic interaction between neurons and glia.These results not only imply that 3-nitropropionic acid blocks energy metabolism prior to exerting neurotoxic damage but also demonstrate that the degree of

  16. Towards real-time metabolic profiling of a biopsy specimen during a surgical operation by 1H high resolution magic angle spinning nuclear magnetic resonance: a case report

    Piotto Martial

    2012-01-01

    Full Text Available Abstract Introduction Providing information on cancerous tissue samples during a surgical operation can help surgeons delineate the limits of a tumoral invasion more reliably. Here, we describe the use of metabolic profiling of a colon biopsy specimen by high resolution magic angle spinning nuclear magnetic resonance spectroscopy to evaluate tumoral invasion during a simulated surgical operation. Case presentation Biopsy specimens (n = 9 originating from the excised right colon of a 66-year-old Caucasian women with an adenocarcinoma were automatically analyzed using a previously built statistical model. Conclusions Metabolic profiling results were in full agreement with those of a histopathological analysis. The time-response of the technique is sufficiently fast for it to be used effectively during a real operation (17 min/sample. Metabolic profiling has the potential to become a method to rapidly characterize cancerous biopsies in the operation theater.

  17. Possibilities and limitations of sup 1 H and sup 13 C nuclear magnetic resonance spectroscopy for the identification and the quantitative determination of some naturally occurring carcinogenic risk factors. [Senecio vulgaris; Senecio vernalis; Senecio jacobaea; Euphorbia ingens

    Pieters, L.

    1988-01-01

    The aim of this work was to develop a phytochemical screening method for some selected carcinogenic or tumor-promoting principles in higher plants. The pyrrolizidine alkaloids from some Senecio species (Compositae or Asteraceae), and the diterpene ester from Croton tiglium L. and Euphorbia ingens E. Mey (Euphorbiaceae) were chosen as representatives of both groups. The possibilities and limitations of {sup 1}H and {sup 13}C nuclear magnetic resonance spectroscopy ({sup 1}H and {sup 13}C NMR) for the analysis of mixtures of carcinogenic pyrrolizidine alkaloids were compared with high performance liquid chromatography, and gas chromatography with high performance liquid chromatography, and gas chromatography was well as gas chromatography - mass spectrometry. Senecio vulgaris L., Senecio vernalis Waldst. and Kit. and Senecio jacobaea L. were investigated.

  18. Quantitative nuclear magnetic resonance spectrometry II. Purity of phosphorus-based agrochemicals glyphosate (N-(phosphonomethyl)-glycine) and profenofos (O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate) measured by 1H and 31P QNMR spectrometry

    The purities of the widely-used herbicide glyphosate (N-(phosphonomethyl)glycine), and the insecticide profenofos (O-(4-bromo-2-chlorophenyl) O-ethyl S-propyl phosphorothioate) were determined by 1H and 31P quantitative nuclear magnetic resonance (QNMR) spectrometry using an internal standard. QNMR does not need a standard reference of the same target analyte, in contrast to chromatographic methods, but only a compound containing the nucleus of interest. Sodium acetate and sodium phosphate of known purity were chosen as internal standards for 1H NMR and 31P NMR), respectively for the water soluble glyphosate and a single internal standard, trimethyl phosphate for both 1H and 31P NMR quantitative analysis of the organic soluble profenofos. These standards have NMR peaks that do not interfere with those of the analyte, they are chemically inert and are soluble in the deuterated solvent. The average purity of glyphosate obtained by 1H NMR (97.07%, σ=0.68) agreed with that by 31P NMR (96.53%, σ=0.90; ANOVA, P=0.074) for the five batches provided by the manufacturer according to the procedures for chemical registration in Australia. The standard deviations of seven independent analyses of a single batch by 1H NMR and 31P NMR were σ=0.24% and σ=0.33%, respectively, values which confirm the exceptional precision of the method. The purity of profenofos by 1H NMR (94.63%, σ=0.14) also agreed with that by 31P NMR (94.62%, σ=0.59; ANOVA, P=0.97). Uncertainty budgets for the measured purities of glyphosate and profenofos show that the uncertainty in the purity of the internal standard is a major contributor to the uncertainty of the result. NMR was also used to establish the impurity profile of both compounds, and quantify the impurities present

  19. Effects of time and temperature of firing on Fe-rich ceramics studied by Mössbauer spectroscopy and two-dimensional 1H-nuclear magnetic resonance relaxometry

    Casieri, Cinzia; De Luca, Francesco; Nodari, Luca; Russo, Umberto; Terenzi, Camilla; Tudisca, Valentina

    2012-10-01

    The combined effects of firing temperature and soaking time on the microstructure of iron-rich porous ceramics have been studied by 57Fe-Mössbauer spectroscopy and 2D 1H nuclear magnetic resonance (NMR) relaxometry using a single-sided probe. Examining water-saturated ceramics using the relaxation correlation method, where longitudinal (T1) and transverse (T2) relaxation times are measured concurrently, provides information about firing-induced changes in both porosity (related to T1) and magnetic properties (related to T2). Comparing the information obtained from 1H-NMR analyses with that obtained from Mössbauer spectroscopy (which characterizes changes in iron-bearing species) shows that the T1-T2 NMR correlation technique is very sensitive to even subtle modifications in the magnetic behavior of Fe-bearing species. Moreover, the single-sided NMR approach allows us to perform millimeter-scale depth-resolved measurements, which can be used to non-invasively study the microstructural heterogeneities associated with non-uniform firing effects inside ceramics. This is in contrast to Mössbauer spectroscopy, which requires that the ceramic samples be ground.

  20. Multivariate analysis of fingerprinting of majority secondary metabolites of propolis of Costa Rica using proton nuclear magnetic resonance (1H-NMR)

    Propolis is produced by Apis mellifera bees from resins of plants that are found around the apiary. The chemical composition is highly variable and Costa Rica has reported without studies of characterization to define the types of propolis in the country. 119 samples were collected from beekeeping areas of the country. The spectrum of 1H-NMR and its antioxidant activity against DPPH radical were measured. The spectra have been divided into 243 blocks of 0,04 ppm and processed with the Minitab software for multivariate analysis. 99 of the samples collected were used for construction of models for the valuation of the predictive ability of the model have been used coefficients of determination (R2) of prediction by the software and the remaining 20 samples. The existence of three types of propolis with chemically different metabolomes were determined by principal component analysis (PCA). A prediction model was constructed by analysis of partial least squares (PLS). The prediction model has allowed to classify a propolis according to the level of anti-oxidant activity (AAO), high (type I and II) or low (type III) from the spectrum of 1H-NMR. The R2 has been 0.88 and R2 prediction of 0, 718 for new samples. The n-coniferyl benzoate of group I and nemorosone of the group II as two discriminated antioxidants among the groups I and II were isolated and high concentration levels of these compounds have been differentiated with respect to type III. This has allowed the construction of a linear discriminant model with a success rate of 100% for the samples used for formulation and 92,9 for the prediction of different samples. The classification systems could be applied to the standardization of the quality of propolis from Costa Rica for future medicinal or cosmetic applications that take advantage of its antioxidant properties. Also, the methylated derivative has isolated and identified of the n-coniferyl benzoate thereof propolis than was obtained his counterpart

  1. 1H relaxation enhancement induced by nanoparticles in solutions: Influence of magnetic properties and diffusion

    Magnetic nanoparticles that induce nuclear relaxation are the most promising materials to enhance the sensitivity in Magnetic Resonance Imaging. In order to provide a comprehensive understanding of the magnetic field dependence of the relaxation enhancement in solutions, Nuclear Magnetic Resonance 1H spin-lattice relaxation for decalin and toluene solutions of various Fe2O3 nanoparticles was investigated. The relaxation experiments were performed in a frequency range of 10 kHz–20 MHz by applying Field Cycling method, and in the temperature range of 257–298 K, using nanoparticles differing in size and shape: spherical – 5 nm diameter, cubic – 6.5 nm diameter, and cubic – 9 nm diameter. The relaxation dispersion data were interpreted in terms of a theory of nuclear relaxation induced by magnetic crystals in solution. The approach was tested with respect to its applicability depending on the magnetic characteristics of the nanocrystals and the time-scale of translational diffusion of the solvent. The role of Curie relaxation and the contributions to the overall 1H spin-lattice relaxation associated with the electronic spin-lattice and spin-spin relaxation was thoroughly discussed. It was demonstrated that the approach leads to consistent results providing information on the magnetic (electronic) properties of the nanocrystals, i.e., effective electron spin and relaxation times. In addition, features of the 1H spin-lattice relaxation resulting from the electronic properties of the crystals and the solvent diffusion were explained

  2. Solution conformations of the B-loop fragments of human transforming growth factor α and epidermal growth factor by 1H nuclear magnetic resonance and restrained molecular dynamics

    A restrained molecular dynamics simulation approach that explicitly includes the effect of the surrounding solvent molecules is applied to the NMR determination of the conformations of the B-loop fragments of human transforming growth factor α and epidermal growth factor. Backbone interproton distance restraints are obtained by using two-dimensional rotating frame nuclear Overhauser effect spectroscopy (ROESY). The simulations are carried out both in vacuum and in water. The results are discussed in terms of the energetics, agreement with the NMR distances, and the flexibility of the peptides

  3. {sup 1}H relaxation enhancement induced by nanoparticles in solutions: Influence of magnetic properties and diffusion

    Kruk, D., E-mail: danuta.kruk@matman.uwm.edu.pl [Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Słoneczna 54, 10-710 Olsztyn (Poland); Experimentalphysik II, Universität Bayreuth, 95440 Bayreuth (Germany); Korpała, A. [Department of Biophysics, Jagiellonian University Medical College, Łazarza 16, 31-530 Kraków (Poland); Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków (Poland); Taheri, S. Mehdizadeh; Förster, S. [Department of Physical Chemistry I, Universität Bayreuth, 95440 Bayreuth (Germany); Kozłowski, A. [NU-MED Group Inc., Center of Radiotherapy and Improvements in Elbląg, Królewiecka 146, 82-300 Elbląg (Poland); Rössler, E. A. [Experimentalphysik II, Universität Bayreuth, 95440 Bayreuth (Germany)

    2014-05-07

    Magnetic nanoparticles that induce nuclear relaxation are the most promising materials to enhance the sensitivity in Magnetic Resonance Imaging. In order to provide a comprehensive understanding of the magnetic field dependence of the relaxation enhancement in solutions, Nuclear Magnetic Resonance {sup 1}H spin-lattice relaxation for decalin and toluene solutions of various Fe{sub 2}O{sub 3} nanoparticles was investigated. The relaxation experiments were performed in a frequency range of 10 kHz–20 MHz by applying Field Cycling method, and in the temperature range of 257–298 K, using nanoparticles differing in size and shape: spherical – 5 nm diameter, cubic – 6.5 nm diameter, and cubic – 9 nm diameter. The relaxation dispersion data were interpreted in terms of a theory of nuclear relaxation induced by magnetic crystals in solution. The approach was tested with respect to its applicability depending on the magnetic characteristics of the nanocrystals and the time-scale of translational diffusion of the solvent. The role of Curie relaxation and the contributions to the overall {sup 1}H spin-lattice relaxation associated with the electronic spin-lattice and spin-spin relaxation was thoroughly discussed. It was demonstrated that the approach leads to consistent results providing information on the magnetic (electronic) properties of the nanocrystals, i.e., effective electron spin and relaxation times. In addition, features of the {sup 1}H spin-lattice relaxation resulting from the electronic properties of the crystals and the solvent diffusion were explained.

  4. Unambiguous assigning of the signals of the nuclear magnetic resonance spectra of {sup 1} H and {sup 13} C of monoterpenes using computational methods; Asignacion inequivoca de las senales del espectro de resonancia magnetica nuclear de {sup 1} H y {sup 13} C de monoterpenos empleando metodos computacionales

    Cortes, F.; Cuevas, G.; Tenorio, J.; Rochin, A.L. [Universidad Nacional Autonoma de Mexico, Instituto de Quimica, A.P. 70213, 04510 Mexico D.F. (Mexico)

    2000-07-01

    Ab initio calculations, within the frame of Density Functional Theory were carried out on camphene and {alpha}-pinene. The {sup 1} H and {sup 13} C shifts were estimated according to the recently developed Sum-Over-States Density Functional Perturbation Theory (SOS-DFPT) as implemented in a modified deMon-KS program. The calculations not only reproduced the observed NMR chemical shifts, quantitatively in the case of {sup 1} H nuclei and qualitatively in the case of {sup 13} C nuclei, but also allow assigning unambiguously the signal on these spectra. (Author)

  5. 1H magnetic resonance spectroscopy of the prostate

    To provide a brief summary of important technical and biochemical aspects and current clinical applications of magnetic resonance spectroscopy (MRS) of the prostate.Material and methods Pertinent radiological and biochemical literature was searched and retrieved via electronic media (medline trademark, pubmed trademark). Basic concepts of MRS of the prostate and its clinical applications were extracted to provide an overview. The prostate lends itself to MRS due to its unique production, storage, and secretion of citrate. While healthy prostate tissue demonstrates high levels of citrate and low levels of choline that marks cell wall turnover, prostate cancer (PCA) utilizes citrate for energy metabolism and shows high levels of choline. The ratio of (choline + creatine)/citrate differentiates healthy prostate tissue and PCA. The combination of magnetic resonance imaging (MRI) and 3-dimensional MRS (3D-MRSI or 3D-CSI) of the prostate localizes PCA to a sextant of the peripheral zone of the prostate with sensitivity/specificity of up to 80/80%. Combined MRI and 3D-MRSI exceed the sensitivity and specificity of sextant biopsy of the prostate. When MRS and MRI agree on PCA presence, the positive predictive value is about 90%. In principle, combined MRI and 3D-MRSI recognize and localize remnant or recurrent cancer after hormone therapy, radiation therapy and cryo-surgery. Since it is non-invasive and radiation-free, combined MRI and 3D-MRSI lends itself to the planning of prostate biopsy and therapy as well as to post-therapeutic follow-up. For broad clinical application, it will be necessary to facilitate MRS examinations and their evaluation and make MRS available to a wider range of institutions. (orig.)

  6. Detection of kestoses and kestose-related oligosaccharides in extracts of Festuca arundinacea, Dactylis glomerate L. , and Asparagus officinalis L. root cultures and invertase by sup 13 C and sup 1 H nuclear magnetic resonance spectroscopy

    Forsythe, K.L.; Feather, M.S.; Gracz, H.; Wong, T.C. (Univ. of Missouri, Columbia (USA))

    1990-04-01

    Previous studies show that {sup 13}C nuclear magnetic resonance spectroscopy can be used to detect and identify mixtures of 1-kestose and neokestose after conversion to the acetate derivatives. In this study, unequivocal assignments are made for the anomeric carbon and proton signals for the above two trisaccharide acetates as well as for 6-kestose hendecaacetate and for nystose tetradecaacetate (a 1-kestose-derived tetrasaccharide). A number of oligosaccharide fractions were isolated from several plant species, converted to the acetates, and nuclear magnetic resonance spectra obtained. Using the above reference data, the following information was obtained. The trisaccharide fraction from Dactylis gomerata L. stem tissue and Asparagus officinalis L. roots contain both 1-kestose and neokestose, and the tetrasaccharide fractions contain three components, one of which is nystose. Penta- and hexasaccharide acetates were also isolated from A. officinalis L. roots and were found to contain, respectively, four and at least five components. All components of both of the above species appear to contain a kestose residue and to be produced by the sequential addition of fructofuranosyl units to these. The trisaccharide fraction from Festuca arundinacea is complex, and contains at least five different components, two of which appear to be 1-kestose and neokestose.

  7. 23Na and 1H NMR Relaxometry of Shale at High Magnetic Field

    Yang, Donghan

    2016-01-01

    Formation evaluation of unconventional reservoirs is challenging due to the coexistence of different phases such as kerogen, bitumen, movable and bound light hydrocarbon and water. Current low-frequency (0.05 T) nuclear magnetic resonance (NMR) laboratory and logging methods are incapable of quantitatively separating the different phases. We demonstrate the utility of high-field (9 T) NMR 2D T1-T2 measurements for separating hydrocarbon and the clay-interacting aqueous phases in shale based on the difference in the frequency dependence of the spin-lattice relaxation time. Furthermore, we demonstrate 23Na NMR as a promising complementary technique to conventional 1H NMR for shale fluid typing, taking advantage of the fact that sodium ions are only present in the aqueous phase. We validate high-field (9 T) 23Na-1H NMR relaxometry for assessing brine-filled porosity and brine salinity in various porous materials, including porous glass, conventional rocks, clays, and shale, and apply it for differentiating hydro...

  8. Nuclear reaction analysis of 1H and 2H in hafnium silicate films on Si

    The 1H(15N,αγ)12C and 2H(3He,p)4He nuclear reactions were employed to detect, respectively, 1H and 2H in hafnium silicates films on Si. The methods employed to achieve quantitative analyses are described. Moreover, by performing annealing sequences in vacuum or O2 followed by 1H2 or 2H2, it was observed that the O2-preanneled films incorporate less H, either 1H or 2H. This was explained by O-deficient, H-trapping sites that are eliminated by the O2 preannealing

  9. Two-dimensional 1H nuclear magnetic resonance study of AaH IT, an anti-insect toxin from the scorpion Androctonus australis Hector. Sequential resonance assignments and folding of the polypeptide chain

    Sequence-specific nuclear magnetic resonance assignments for the polypeptide backbone and for most of the amino acid side-chain protons, as well as the general folding of AaH IT, are described. AaH IT is a neurotoxin purified from the venom of the scorpion Androctonus australis Hector and is specifically active on the insect nervous system. The secondary structure and the hydrogen-bonding patterns in the regular secondary structure elements are deduced from nuclear Overhauser effects and the sequence locations of the slowly exchanging amide protons. The backbone folding is determined by distance geometry calculations with the DISMAN program. The regular secondary structure includes two and a half turns of α-helix running from residues 21 to 30 and a three-stranded antiparallel β-sheet including peptides 3-5, 34-38, and 41-46. Two tight turns are present, one connecting the end of the α-helix to an external strand of the β-sheet, i.e., turn 31-34, and another connecting this same strand to the central one, i.e., turn 38-41. The differences in the specificity of these related proteins, which are able to discriminate between mammalian and insect voltage-dependent sodium channels of excitable tissues, are most probably brought about by the position of the C-terminal peptide with regard to a hydrophobic surface common to all scorpion toxins examined thus far. Thus, the interaction of a given scorpion toxin with its receptor might well be governed by the presence of this solvent-exposed hydrophobic surface, whereas adjacent areas modulate the specificity of the interaction

  10. A conformational study of the adducts of 2'-deoxythymidine and 2,2,6,6-tetramethyl-1,4-piperidone-N-oxyl by sup(1)H and sup(13)C nuclear magnetic resonance

    γ-Irradiation of oxygen-free, aqueous solutions of 2'-deoxythymidine in the presence of the organic nitroxide free radical, 2,2,6,6-tetramethyl-1,4-piperidone-N-oxyl (TAN) leads to a complex mixture of products in which the TAN moiety is linked to the C5 or C6 position of a 5,6-saturated thymine ring. Extensive sup(1)H and sup(13)C nmr data are provided for the eight TAN-dT adducts which are produced in the largest amounts. The results show that the conformational properties of the sugar moiety are dependent on the point of attachment of the TAN group and the configuration of the standard thymine ring

  11. 15N-{1H} NOE experiment at high magnetic field strengths

    The heteronuclear 15N-{1H} NOE values are typically determined by taking the ratio of 15N signal intensities recorded in the presence and absence of 1H saturation prior to evolution of 15N magnetization. Since the intensity ratio of two independent experiments is taken, complete recovery of 15N magnetization during the scan repetition delay is critical to obtain reliable NOE values. Because it may not be practical to wait for the complete recovery of magnetization at high magnetic fields, Solomon equations may be used to correct measured NOE values. Here, based on experiments and simulations, we show that since the cross-correlation between 1H-15N dipole and 15N chemical shift anisotropy becomes significant at high fields for small or deuterated proteins, measured NOE values can not be accurately corrected based on the Solomon equations. We also discuss ranges of rotational correlation times and proton spin-flip rate, in which the NOE values can be corrected by the equations

  12. Intermolecular interactions in nuclear magnetic resonance: medium shifts of the 1H and 13C nuclei in methane in the gas phase and in solution and of gaseous 3He

    An analysis has been carried out of the continuum and the binary collision models used in the description of NMR solvent shifts caused by Van der Waals intermolecular interactions. The basic assumption underlying the models, i.e. σ sub(w)= -BE2 (I) is examined. The possible effects on I of such phenomena as B anisotropy and field gradients are discussed, as well as the inadequacy of I in representing the true intermolecular shielding. A new expression for E2 is proposed, which in connection with I forms the bais of a modified binary collision model. The new E2 expression takes into account the dynamic character of the interaction. The major obstacle to the binary collision model, the requirement for accurate parameters for the intermolecular potential employed in the statistical-mechanical averaging, is alleviated by the establishment of priority rules to be used in the selection of these paramters. The proposed binary collision model and a collision model are used to interpret the 1H and 13C medium shifts of methane in the gas phase and in solution. The proton shift data conform equally well to either model; the 13C data indicate that a large solvent-dependent term contributes to the observed medium shifts in addition to I. Proton and 13C B parameters of methane in the gas phase and in solution are discussed. Preliminary results of 3He medium shifts as a function of gas density are presented. An extracted B parameter based on the proposed binary collision model appears to agree well with the result of a quantum-mechanical calculation of B for a 3He atom in a uniform static electric field. (LL)

  13. Magnetic hyperthermia efficiency and 1H-NMR relaxation properties of iron oxide/paclitaxel-loaded PLGA nanoparticles

    Ruggiero, Maria R.; Geninatti Crich, Simonetta; Sieni, Elisabetta; Sgarbossa, Paolo; Forzan, Michele; Cavallari, Eleonora; Stefania, Rachele; Dughiero, Fabrizio; Aime, Silvio

    2016-07-01

    Magnetic iron oxide nanoparticles (Fe-NPs) can be exploited in biomedicine as agents for magnetic fluid hyperthermia (MFH) treatments and as contrast enhancers in magnetic resonance imaging. New, oleate-covered, iron oxide particles have been prepared either by co-precipitation or thermal decomposition methods and incorporated into poly(lactic-co-glycolic acid) nanoparticles (PLGA-Fe-NPs) to improve their biocompatibility and in vivo stability. Moreover, the PLGA-Fe-NPs have been loaded with paclitaxel to pursue an MFH-triggered drug release. Remarkably, it has been found that the nanoparticle formulations are characterized by peculiar 1H nuclear magnetic relaxation dispersion (NMRD) profiles that directly correlate with their heating potential when exposed to an alternating magnetic field. By prolonging the magnetic field exposure to 30 min, a significant drug release was observed for PLGA-Fe-NPs in the case of the larger-sized magnetic nanoparticles. Furthermore, the immobilization of lipophilic Fe-NPs in PLGA-NPs also made it possible to maintain Néel relaxation as the dominant relaxation contribution in the presence of large iron oxide cores (diameters of 15–20 nm), with the advantage of preserving their efficiency when they are entrapped in the intracellular environment. The results reported herein show that NMRD profiles are a useful tool for anticipating the heating capabilities of Fe-NPs designed for MFH applications.

  14. Magnetic hyperthermia efficiency and (1)H-NMR relaxation properties of iron oxide/paclitaxel-loaded PLGA nanoparticles.

    Ruggiero, Maria R; Crich, Simonetta Geninatti; Sieni, Elisabetta; Sgarbossa, Paolo; Forzan, Michele; Cavallari, Eleonora; Stefania, Rachele; Dughiero, Fabrizio; Aime, Silvio

    2016-07-15

    Magnetic iron oxide nanoparticles (Fe-NPs) can be exploited in biomedicine as agents for magnetic fluid hyperthermia (MFH) treatments and as contrast enhancers in magnetic resonance imaging. New, oleate-covered, iron oxide particles have been prepared either by co-precipitation or thermal decomposition methods and incorporated into poly(lactic-co-glycolic acid) nanoparticles (PLGA-Fe-NPs) to improve their biocompatibility and in vivo stability. Moreover, the PLGA-Fe-NPs have been loaded with paclitaxel to pursue an MFH-triggered drug release. Remarkably, it has been found that the nanoparticle formulations are characterized by peculiar (1)H nuclear magnetic relaxation dispersion (NMRD) profiles that directly correlate with their heating potential when exposed to an alternating magnetic field. By prolonging the magnetic field exposure to 30 min, a significant drug release was observed for PLGA-Fe-NPs in the case of the larger-sized magnetic nanoparticles. Furthermore, the immobilization of lipophilic Fe-NPs in PLGA-NPs also made it possible to maintain Néel relaxation as the dominant relaxation contribution in the presence of large iron oxide cores (diameters of 15-20 nm), with the advantage of preserving their efficiency when they are entrapped in the intracellular environment. The results reported herein show that NMRD profiles are a useful tool for anticipating the heating capabilities of Fe-NPs designed for MFH applications. PMID:27265726

  15. 1H magnetic resonance spectroscopy (1H MRS) in the initially differentiating recurrent brain gliomas after radiation therapy from delayed cerebral necrosis

    Objective: To evaluate 1H magnetic resonance spectroscopy (1H MRS) in the differentiating recurrent brain gliomas after radiation therapy from delayed cerebral necrosis. Methods: Fifteen patients who had clinical and CT, MRI changes that suggested a diagnosis of delayed cerebral necrosis or recurrent brain tumor after radiation therapy and 5 patients who had a definite clinical diagnosis of delayed cerebral necrosis underwent single MR spectroscopy simultaneously both in the lesion's region and the contralateral side. Results: Of the former 15 cases who proved by surgical pathology, 14 cases were gliomas, 1 case was delayed cerebral necrosis, and their etiologic diagnoses of 1H MRS were correct. (1) 1H MRS in 14 cases with gliomas exhibited specific spectral peaks including prominent choline-containing compounds (Cho), decreased or absent acetylaspartate (NAA) and total creatine (Cr), and the metabolic ratios showed significantly increased Cho/Cr, decreased NAA/Cr. Twelve cases showed abnormal lactate (Lac). (2) Among 6 cases with delayed cerebral necrosis, 5 cases exhibited decreased or absent Cho, NAA, Cr, and abnormal Lipid, 1 case showed absent Cho, NAA, and Cr with a flat curve without Lac. Conclusion: 1H MRS was positively claimed for differentiating recurrent brain gliomas after radiation therapy from delayed cerebral necrosis

  16. 1H-magnetic resonance spectroscopy of vascular endothelial growth factor-induced neuroprotection following acute cerebral ischemia and reperfusion

    Li Yi; Haiou Zhang; Hao Lei; Li Wei

    2008-01-01

    BACKGROUND: It has become generally accepted that measuring N-acetyI-L-aspartic acid through the use of 1H-magnetic resonance spectroscopy (1H-MRS) could be used to evaluate neuronal injury. OBJECTIVE: To study metabolic changes of N-acetyl-L-aspanic acid surrounding the acute cerebral ischcmia area following vascular endothelial growth factor (VEGF) treatment using 1H-MRS imaging, and to evaluate the neuroprotective effects of VEGE.DESIGN, TIME AND SETTING: Randomly controlled animal study, according to one-factor analysis of variance, was performed at the Shenzhen Hospital of Peking University and State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences from August 2003 to December 2005.MATERIALS: Twelve healthy, adult, Sprague Dawley rats were used to establish an ischemia/reperfusion model through the use of middle cerebral artery occlusion. The 4.7T superconducting nuclear magnetic resonance meter was provided by Brucker Company. VEGF164 was purchased from Shenzhen Jingmei Bioengineering Co., Ltd. Titus ancsthesia machine was purchased from Draeger Medical AG & Co. KG.METHODS: The rats were randomly divided into model control (n = 6) and VEGF-injected (n = 6) groups. All animals received 60-minute middle cerebral artery occlusion and 24-hour repcrfusion. Lateral cerebral ventricle injection was performed by stereotaxic technique at respective time points. The VEGF group received 0. 1 μ g/μ L VEGF (5 μL), and the model group received the same amount of normal saline, once daily for 3 days.MAIN OUTCOME MEASURES: Metabolic changes of N-acetyl-L-aspartic acid and lactic acid following cerebral ischemia and reperfusion were detected using 1H-MRS, and the ischemic volume was measured.RESULTS: Twelve rats were included in the final analysis. =H-MRS results revealed that the ischemic volume increased in the control group compared with prior to injection (P < 0.01). In the

  17. Application of 1H magnetic resonance spectroscopy in diagnosis and differential diagnosis of cerebral infection

    Objective: To study the application of single voxel proton magnetic resonance spectroscopy in diagnosis and differential diagnosis of cerebral infection according to manifestations of the 8 patients with cerebritis and 13 patients with gliomas. Methods: The patients including 8 cerebral abscess and 13 gliomas were examined with MRS. And the quantity of the NAA, Cho, Cr, Lip, Lac, AA were measured and compared. Results: There were differences between cerebral abscess and tumors on MRS. NAA/Cr and Cho/Cr of abscess were 4.114±3.637 and 3.084±0.933. NAA/Cr and Cho/Cr of tumors were 1.064±0.823 and 5.987±4.380. There was amino acids (AA) could be seen in some of cerebral abscess. Conclusion: 1H magnetic resonance spectroscopy can supply important information in diagnosis cerebral infection and differentiate information with tumor. (authors)

  18. Quantification of choline concentration following liver cell apoptosis using 1H magnetic resonance spectroscopy

    Zhi-Wei Shen; Zhen Cao; Ke-Zeng You; Zhong-Xian Yang; Ye-Yu Xiao; Xiao-Fang Cheng; Yao-Wen Chen

    2012-01-01

    AIM:To evaluate the feasibility of quantifying liver choline concentrations in both normal and apoptotic rabbit livers in vivo,using 1H magnetic resonance spectroscopy (1H-MRS).METHODS:1H-MRS was performed in 18 rabbits using a 1.5T GE MR system with an eight-channel head/neck receiving coil.Fifteen rabbits were injected with sodium selenite at a dose of 10 μmol/kg to induce the liver cell apoptosis.Point-resolved spectroscopy sequencelocalized spectra were obtained from 10 livers once before and once 24 h after sodium selenite injection in vivo.T1 and T2 relaxation time of water and choline was measured separately in the livers of three healthy rabbits and three selenite-treated rabbits.Hematoxylin and eosin and dUTP-biotin nick end labeling (TUNEL) staining was used to detect and confirm apoptosis.Choline peak areas were measured relative to unsuppressed water using LCModel.Relaxation attenuation was corrected using the average of T1 and T2 relaxation time.The choline concentration was quantified using a formula,which was tested by a phantom with a known concentration.RESULTS:Apoptosis of hepatic cells was confirmed by TUNEL assay.In phantom experiment,the choline concentration (3.01 mmol/L),measured by 1H-MRS,was in good agreement with the actual concentration (3 mmol/L).The average T1 and T2 relaxation time of choline was 612 ± 15 ms and 74 ± 4 ms in the control group and 670 ± 27 ms and 78 ± 5 ms in apoptotic livers in vivo,respectively.Choline was quantified in 10 rabbits,once before and once after the injection with sodium selenite.The choline concentration decreased from 14.5 ± 7.57 mmol/L before sodium selenite injection to 10.8 ± 6.58 mmol/L (mean ± SD,n =10) after treatment (Z =-2.395,P < 0.05,two-sample paired Wilcoxon test).CONCLUSION:1H-MRS can be used to quantify liver choline in vivo using unsuppressed water as an internal reference.Decreased liver choline concentrations are found in sodium selenite-treated rabbits undergoing liver cell

  19. Nuclear localization of human DNA mismatch repair protein exonuclease 1 (hEXO1)

    Knudsen, Nina Østergaard; Nielsen, Finn Cilius; Vinther, Lena;

    2007-01-01

    localization signals (NLSs) in hEXO1. Using fluorescent fusion proteins, we show that the sequence 418KRPR421, which exhibit strong homology to other monopartite NLS sequences, is responsible for correct nuclear localization of hEXO1. This NLS sequence is located in a region that is also required for hEXO1......Human exonuclease 1 (hEXO1) is implicated in DNA mismatch repair (MMR) and mutations in hEXO1 may be associated with hereditary nonpolyposis colorectal cancer (HNPCC). Since the subcellular localization of MMR proteins is essential for proper MMR function, we characterized possible nuclear...... interaction with hMLH1 and we show that defective nuclear localization of hEXO1 mutant proteins could be rescued by hMLH1 or hMSH2. Both hEXO1 and hMLH1 form complexes with the nuclear import factors importin beta/alpha1,3,7 whereas hMSH2 specifically recognizes importin beta/alpha3. Taken together, we infer...

  20. GHz nuclear magnetic resonance

    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.

  1. The nuclear reaction n + 3He -> 1H + 3H as proximity reaction

    The present thesis tries to give by means of the nuclear reaction n + 3He -> 1H + 3H as proximity reaction on the three-particle system 3He + 9Be -> 1H + 3H + 8Be an experimental verification to the second term of a multiple scattering series. The study of these rescattering effects is of great interest for the present theory of the final-state interaction. At three incident energies (7.08 MeV, 8.98 MeV, and 6.37 MeV) to detector telescopes identify the exit channel of the three-particle system in list-mode coincidence experiments according to protons and tritons. Peaks on the kinematical curves occur. The detailed study of their kinematic behaviour allows to exclude the inconcurrence to the proximity reaction lying cascade decays via intermediate states in 4He, 9B, and 11B. Regarding the Coulomb interaction the experimental results can be also explained in the sense of the classical kinematics by the proximity model. (orig.)

  2. In vivo research in astrocytoma cell proliferation with {sup 1}H-magnetic resonance spectroscopy: correlation with histopathology and immunohistochemistry

    Chen, Jun; Li, Tao; Chen, Xi-Lan [Renmin Hospital of Wuhan University, Department of Radiology, Wuhan, Hubei Province (China); Huang, Shu-Lan [Renmin Hospital of Wuhan University, Department of Neurosurgery, Wuhan, Hubei Province (China)

    2006-05-15

    Assessment of brain tumor proliferative potential provides important prognostic information that supplements standard histopathologic grading. Proton magnetic resonance spectroscopy ({sup 1}H-MRS) gives completely different information, relating to cell membrane proliferation, neuronal damage, energy metabolism and necrotic transformation of brain or tumor tissues. The aim of this study was to investigate the relationship between {sup 1}H-MRS and tumor proliferative potential in astrocytomas. We studied 34 patients with histologically verified astrocytomas using the {sup 1}H-MRS protocol following routine MRI preoperatively. The tumor in 26 of these patients was classified as grade I/II (low grade), and the tumor in the remaining patients as grade III/IV (high grade) according to the World Health Organization classification criteria of nervous system tumors (2000). The tumor in 21 patients was homogeneous astrocytoma, and of these 17 were classified as low grade and 4 as high grade. Expression of proliferating cell nuclear antigen (PCNA) was determined immunohistochemically using streptavidin-biotin-peroxidase complex (SP) staining. The ratios of choline (Cho) to N-acetylaspartate (NAA) and Cho to creatine (Cr) in those with high-grade astrocytomas (n=4) were significantly higher than in those with low-grade astrocytomas (n=17) (t=2.899, P=0.009; t=3.96, P=0.001, respectively), and were found to be significantly correlated with the expression of PCNA in 21 patients with homogeneous astrocytomas (r=0.455, P=0.038; r=0.633, P=0.002, respectively). (orig.)

  3. 1H magnetic resonance spectroscopy in the diagnosis of paediatric low grade brain tumours

    Introduction: Low grade gliomas are the commonest brain tumours in children but present in a myriad of ways, each with its own treatment challenges. Conventional MRI scans play an important role in their management but have limited ability to identify likely clinical behaviour. The aim of this study is to investigate 1H magnetic resonance spectroscopy (MRS) as a method for detecting differences between the various low grade gliomas and related tumours in children. Patients and methods: Short echo time single voxel 1H MRS at 1.5 or 3.0 T was performed prior to treatment on children with low grade brain tumours at two centres and five MR scanners, 69 cases had data which passed quality control. MRS data was processed using LCModel to give mean spectra and metabolite concentrations which were compared using T-tests, ANOVA, Receiver Operator Characteristic curves and logistic regression in SPSS. Results: Significant differences were found in concentrations of key metabolites between glioneuronal and glial tumours (T-test p < 0.05) and between most of the individual histological subtypes of low grade gliomas. The discriminatory metabolites identified, such as choline and myoinositol, are known tumour biomarkers. In the set of pilocytic astrocytomas and unbiopsied optic pathway gliomas, significant differences (p < 0.05, ANOVA) were found in metabolite profiles of tumours depending on location and patient neurofibromatosis type 1 status. Logistic regression analyses yielded equations which could be used to assess the probability of a tumour being of a specific type. Conclusions: MRS can detect subtle differences between low grade brain tumours in children and should form part of the clinical assessment of these tumours

  4. {sup 1}H magnetic resonance spectroscopy in the diagnosis of paediatric low grade brain tumours

    Orphanidou-Vlachou, E., E-mail: eleni.orphanidou@googlemail.com [School of Cancer Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Birmingham Children' s Hospital NHS Foundation Trust, Whittall Street, Birmingham, B4 6NH (United Kingdom); Auer, D., E-mail: dorothee.auer@nottingham.ac.uk [Division of Academic Radiology, School of Medical and Surgical Sciences, The University of Nottingham, University Park, Nottingham, NG7 2RD (United Kingdom); Children' s Brain Tumour Research Centre, Queens Medical Centre, University of Nottingham (United Kingdom); Brundler, M.A., E-mail: marie-anne.brundler@bch.nhs.uk [Birmingham Children' s Hospital NHS Foundation Trust, Whittall Street, Birmingham, B4 6NH (United Kingdom); Davies, N.P., E-mail: nigel.davies@nhs.net [School of Cancer Sciences, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT (United Kingdom); Birmingham Children' s Hospital NHS Foundation Trust, Whittall Street, Birmingham, B4 6NH (United Kingdom); Department of Medical Physics, University Hospitals Birmingham NHS Foundation Trust, Mindelsohn Way, Edgbaston, Birmingham, B15 2WB (United Kingdom); Jaspan, T., E-mail: tim.jaspan@nuh.nhs.uk [Children' s Brain Tumour Research Centre, Queens Medical Centre, University of Nottingham (United Kingdom); MacPherson, L., E-mail: Lesley.MacPherson@bch.nhs.uk [Birmingham Children' s Hospital NHS Foundation Trust, Whittall Street, Birmingham, B4 6NH (United Kingdom); Natarajan, K., E-mail: Kal.Natarajan@uhb.nhs.uk [Birmingham Children' s Hospital NHS Foundation Trust, Whittall Street, Birmingham, B4 6NH (United Kingdom); Department of Medical Physics, University Hospitals Birmingham NHS Foundation Trust, Mindelsohn Way, Edgbaston, Birmingham, B15 2WB (United Kingdom); and others

    2013-06-15

    Introduction: Low grade gliomas are the commonest brain tumours in children but present in a myriad of ways, each with its own treatment challenges. Conventional MRI scans play an important role in their management but have limited ability to identify likely clinical behaviour. The aim of this study is to investigate {sup 1}H magnetic resonance spectroscopy (MRS) as a method for detecting differences between the various low grade gliomas and related tumours in children. Patients and methods: Short echo time single voxel {sup 1}H MRS at 1.5 or 3.0 T was performed prior to treatment on children with low grade brain tumours at two centres and five MR scanners, 69 cases had data which passed quality control. MRS data was processed using LCModel to give mean spectra and metabolite concentrations which were compared using T-tests, ANOVA, Receiver Operator Characteristic curves and logistic regression in SPSS. Results: Significant differences were found in concentrations of key metabolites between glioneuronal and glial tumours (T-test p < 0.05) and between most of the individual histological subtypes of low grade gliomas. The discriminatory metabolites identified, such as choline and myoinositol, are known tumour biomarkers. In the set of pilocytic astrocytomas and unbiopsied optic pathway gliomas, significant differences (p < 0.05, ANOVA) were found in metabolite profiles of tumours depending on location and patient neurofibromatosis type 1 status. Logistic regression analyses yielded equations which could be used to assess the probability of a tumour being of a specific type. Conclusions: MRS can detect subtle differences between low grade brain tumours in children and should form part of the clinical assessment of these tumours.

  5. Single voxel 1 H magnetic resonance spectroscopy in the diagnosis of musculoskeletal mass lesions

    Shalini Agarwal

    2014-01-01

    Full Text Available Introduction: In vivo magnetic resonance spectroscopy (MRS is an established technique for evaluation of malignant tumors in brain, breast, prostate, etc., However, its efficacy in the diagnosis of musculoskeletal (MSK mass lesions is yet to be established. We present our experience with MRS of these lesions. Materials and Methods: Magnetic resonance imaging (MRI, dynamic contrast-enhanced MRI and single-voxel 1 H MRS was performed in 30 consecutive patients with histologically proven benign and malignant MSK tumors/mass lesions each, on a 1.5-T magnetic resonance scanner. MRS was performed with echo times (TE of 40, 135 and 270 ms. A clearly identifiable peak at 3.2 ppm in at least two of the three spectra acquired at the three TE was taken as positive for choline. MRS imaging and enhancement patterns were compared in these two groups and were analyzed by a Radiologist blinded to the histopathological findings. Results: Ages of patients in the malignant age group ranged from 2 to 65 years (M: F - 19:11 while that of patients in the benign group ranged from 7 months to 56 years (M: F - 17:13. There were two patients with Type I curve, 18 with Type II curve and 10 with Type III curve on dynamic contrast enhanced images in the malignant group while there were no patients with Type I curve, 5 with Type II curve and 25 with Type III curve in the benign group. The sensitivity of MRS for predicting malignancy was 60%, specificity was 93.33%, positive predictive value was 90%, negative predictive value was 70% and accuracy was 76.66%. Conclusion: MRS is a promising technique for evaluation of MSK mass lesions. The accuracy at present remains low. We recommend that it be used as an adjunct to routine MRI.

  6. Integration of 3D 1H-magnetic resonance spectroscopy data into neuronavigation systems for tumor biopsies

    Kanberoglu, Berkay; Moore, Nina Z.; Frakes, David; Karam, Lina J.; Debbins, Josef P.; Preul, Mark C.

    2013-03-01

    Many important applications in clinical medicine can benefit from the fusion of spectroscopy data with anatomical images. For example, the correlation of metabolite profiles with specific regions of interest in anatomical tumor images can be useful in characterizing and treating heterogeneous tumors that appear structurally homogeneous. Such applications can build on the correlation of data from in-vivo Proton Magnetic Resonance Spectroscopy Imaging (1HMRSI) with data from genetic and ex-vivo Nuclear Magnetic Resonance spectroscopy. To establish that correlation, tissue samples must be neurosurgically extracted from specifically identified locations with high accuracy. Toward that end, this paper presents new neuronavigation technology that enhances current clinical capabilities in the context of neurosurgical planning and execution. The proposed methods improve upon the current state-of-the-art in neuronavigation through the use of detailed three dimensional (3D) 1H-MRSI data. MRSI spectra are processed and analyzed, and specific voxels are selected based on their chemical contents. 3D neuronavigation overlays are then generated and applied to anatomical image data in the operating room. Without such technology, neurosurgeons must rely on memory and other qualitative resources alone for guidance in accessing specific MRSI-identified voxels. In contrast, MRSI-based overlays provide quantitative visual cues and location information during neurosurgery. The proposed methods enable a progressive new form of online MRSI-guided neuronavigation that we demonstrate in this study through phantom validation and clinical application.

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

    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)

  8. 1H-Magnetic resonance spectroscopy in Mb. Alzheimer's and MCI patients

    In this study a proton magnetic spectroscopy was conducted on 38 patients suffering from Alzheimer, 10 patients with MCI (mild cognitive impairment) and 21 elderly controls. The analyzed metabolites were N-acetyl-aspartate (NAA), creatine (Cr), choline (Cho) and myo-Inositol (Ins). 1H-MRS was conducted in the cingulated gyri and the centrum semiovale of 38 patients with AD, 10 patients with MCI and 21 elderly controls. A STEAM sequence was used at 1,5 Tesla. The values of NAA, Cho, Cr and Ins were measured and the ratios of NAA/Cr, NAA/Cho, Cho/Cr and Ins/Cr were statistically evaluated. The Ins/Cr Ratio in the posterior cingulated gyrus was significantly lower in the MCI group than in the DAT group (p=0,007), while the decrease of the Ins/Cr Ratio in the compared controls was not significant. The NAA/Cr ratio was not significantly different whether in patients with AD, MCI nor in the examined controls. NAA/Cho and Cho/Cr ratios were likewise not significantly different in the three groups. Our findings of an increased Ins/Cr Ratio in the AD group might indicate the beginning of glial activation in the posterior cingulated gyri. As the other examined ratios were not significantly different among the three groups, our patients may not have suffered significant neuronal loss yet. (author)

  9. Localization of hydrophobic ions in phospholipid bilayers using 1H nuclear Overhauser effect spectroscopy

    The binding location for the hydrophobic ions tetraphenylphosphonium (TPP+) and tetraphenylboron (TPB-) was studied in sonicated phosphatidylcholine (PC) vesicles by measuring time-dependent and steady-state intermolecular 1H nuclear Overhauser effects (NOE's). Intermolecular cross-relaxation was also investigated by two-dimensional NOE spectroscopy. Information on the distance and order parameter dependence of the NOE's was obtained from a simple simulation of the NOE's in the alkyl chain region. Taken together, the NOE data and the simulation provide strong evidence that TPB- and TPP+, at low concentrations (≤ 10 mol %), are localized in the alkyl chain region of the bilayer. At these lower concentrations of TPP+ or TPB-, no significant effect on lipid 13C T1 or T2 relaxation rates is detected. The proposed location is consistent with the expected free energy profiles for hydrophobic ions and with the carbonyl oxygens or interfacial water as the source of the membrane dipole potential. At higher ion/lipid ratios (≥ 20 mol %), TPB-/lipid NOE's increase. This results from a specific association of TPB- with the choline head group

  10. Non-invasive assessment of hepatic fat accumulation in chronic hepatitis C by 1H magnetic resonance spectroscopy

    Background: Liver biopsy is the standard method for diagnosis of hepatic steatosis, but is invasive and carries some risk of morbidity. Aims and methods: Quantification of hepatocellular lipid content (HCL) with non-invasive single voxel 1H magnetic resonance spectroscopy (MRS) at 3 T was compared with histological grading and biochemical analysis of liver biopsies in 29 patients with chronic hepatitis C. Body mass index, indices of insulin resistance (homeostasis model assessment index, HOMA-IR), serum lipids and serum liver transaminases were also quantified. Results: HCL as assessed by 1H MRS linearly correlated (r = 0.70, p 1H MRS (r = 0.63, p 1H MRS is a valid and useful method for quantification of HCL content in patients with chronic hepatitis C and can be easily applied to non-invasively monitoring of steatosis during repeated follow-up measurements in a clinical setting.

  11. Relativistic Force Field: Parametrization of (13)C-(1)H Nuclear Spin-Spin Coupling Constants.

    Kutateladze, Andrei G; Mukhina, Olga A

    2015-11-01

    Previously, we reported a reliable DU8 method for natural bond orbital (NBO)-aided parametric scaling of Fermi contacts to achieve fast and accurate prediction of proton-proton spin-spin coupling constants (SSCC) in (1)H NMR. As sophisticated NMR experiments for precise measurements of carbon-proton SSCCs are becoming more user-friendly and broadly utilized by the organic chemistry community to guide and inform the process of structure determination of complex organic compounds, we have now developed a fast and accurate method for computing (13)C-(1)H SSCCs. Fermi contacts computed with the DU8 basis set are scaled using selected NBO parameters in conjunction with empirical scaling coefficients. The method is optimized for inexpensive B3LYP/6-31G(d) geometries. The parametric scaling is based on a carefully selected training set of 274 ((3)J), 193 ((2)J), and 143 ((1)J) experimental (13)C-(1)H spin-spin coupling constants reported in the literature. The DU8 basis set, optimized for computing Fermi contacts, which by design had evolved from optimization of a collection of inexpensive 3-21G*, 4-21G, and 6-31G(d) bases, offers very short computational (wall) times even for relatively large organic molecules containing 15-20 carbon atoms. The most informative SSCCs for structure determination, i.e., (3)J, were computed with an accuracy of 0.41 Hz (rmsd). The new unified approach for computing (1)H-(1)H and (13)C-(1)H SSCCs is termed "DU8c". PMID:26414291

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

    Bachert, Peter; Bellemann, Matthias E.

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

  13. Longitudinal monitoring of metabolic alterations in cuprizone mouse model of multiple sclerosis using 1H-magnetic resonance spectroscopy.

    Orije, Jasmien; Kara, Firat; Guglielmetti, Caroline; Praet, Jelle; Linden, van der, M.; Ponsaerts, Peter; Verhoye, Marleen

    2015-01-01

    Non-invasive measures of well-known pathological hallmarks of multiple sclerosis (MS) such as demyelination, inflammation and axonal injury would serve as useful markers to monitor disease progression and evaluate potential therapies. To this end, in vivo localized proton magnetic resonance spectroscopy ((1)H-MRS) provides a powerful means to monitor metabolic changes in the brain and may be sensitive to these pathological hallmarks. In our study, we used the cuprizone mouse model to study pa...

  14. Interaction of apocytochrome c and derived polypeptide fragments with sodium dodecyl sulfate micelles monitored by photochemically induced dynamic nuclear polarization in 1H NMR and fluorescence spectroscopy

    The topology of apocytochrome c, the heme-free precursor of the mitochondrial protein cytochrome c, was investigated in a lipid-associated form. For this purpose photochemically induced dynamic nuclear polarization 1H nuclear magnetic resonance (CIDNP 1H NMR) spectroscopy and quenching of tryptophan and tyrosine fluorescence by acrylamide were applied to an apocytochrome c-sodium dodecyl sulfate (SDS) micellar system. A pH titration of the chemical shifts of the histidine C2 proton resonances of apocytochrome c, using conventional 1H NMR, yielded pKa's of 5.9 ± 0.1 and 6.2 ± 0.1, which were assigned to histidine-18 and -33 and histidine-26, respectively. In the presence of SDS micelles an average pKa of 8.1 ± 0.1 was obtained for all histidine C2 protons. Photo-CIDNP enhancements of the histidine, tryptophan, and tyrosine residues, contained in the intact apocytochrome c and in chemically and enzymatically prepared fragments of the precursor, were reduced in the presence of SDS micelles. Similarly, the quenching of the tryptophan fluorescence of the polypeptides by acrylamide was diminished in the presence of SDS. These results indicate the aromatic residues studied are localized in the interface of the SDS micelle

  15. Interaction of apocytochrome c and derived polypeptide fragments with sodium dodecyl sulfate micelles monitored by photochemically induced dynamic nuclear polarization in sup 1 H NMR and fluorescence spectroscopy

    Snel, M.M.E.; Kaptein, R.; de Kruijff, B. (Univ. of Utrecht (Netherlands))

    1991-04-09

    The topology of apocytochrome c, the heme-free precursor of the mitochondrial protein cytochrome c, was investigated in a lipid-associated form. For this purpose photochemically induced dynamic nuclear polarization {sup 1}H nuclear magnetic resonance (CIDNP {sup 1}H NMR) spectroscopy and quenching of tryptophan and tyrosine fluorescence by acrylamide were applied to an apocytochrome c-sodium dodecyl sulfate (SDS) micellar system. A pH titration of the chemical shifts of the histidine C2 proton resonances of apocytochrome c, using conventional {sup 1}H NMR, yielded pK{sub a}'s of 5.9 {plus minus} 0.1 and 6.2 {plus minus} 0.1, which were assigned to histidine-18 and -33 and histidine-26, respectively. In the presence of SDS micelles an average pK{sub a} of 8.1 {plus minus} 0.1 was obtained for all histidine C2 protons. Photo-CIDNP enhancements of the histidine, tryptophan, and tyrosine residues, contained in the intact apocytochrome c and in chemically and enzymatically prepared fragments of the precursor, were reduced in the presence of SDS micelles. Similarly, the quenching of the tryptophan fluorescence of the polypeptides by acrylamide was diminished in the presence of SDS. These results indicate the aromatic residues studied are localized in the interface of the SDS micelle.

  16. 1H magnetic resonance spectroscopy of the brain in paediatrics: The diagnosis of creatine deficiencies

    Sijens, P.E.; Oudkerk, M.

    2005-01-01

    The diagnosis of creatine deficiencies, a paediatric application of magnetic resonance spectroscopy that has already become a diagnostic tool in clinical practice, is reviewed and illustrated with results from recent examinations

  17. Magnetic catalysis in nuclear matter

    Haber, Alexander; Preis, Florian; Schmitt, Andreas

    2014-01-01

    A strong magnetic field enhances the chiral condensate at low temperatures. This so-called magnetic catalysis thus seeks to increase the vacuum mass of nucleons. We employ two relativistic field-theoretical models for nuclear matter, the Walecka model and an extended linear sigma model, to discuss the resulting effect on the transition between vacuum and nuclear matter at zero temperature. In both models we find that the creation of nuclear matter in a sufficiently strong magnetic field becom...

  18. A retunable surface coil for high field 31P and 1H magnetic resonance evaluations of the living mouse leg

    This study presents a retunable surface coil that can be adjusted to at least two Larmor frequencies sequentially without the need to remove the coil from the magnet and while avoiding interference between channels. A prototype 1H/31P surface coil for the analysis of the in vivo mouse leg under electrical stimulation was designed for operation at 11.75 T. The coil has a high-quality factor of over 100 for both operational frequencies. To demonstrate the capabilities of this simple design, in vivo experiments were conducted to acquire high-resolution 1H images and 31P spectra of the C57BL/6 mouse leg, both with high temporal resolution. Proton diffusion tensor imaging was also performed to evaluate rodent skeletal muscle architecture. This design makes the acquisition of physiological data about both muscle structure and energetics (PCr, ATP and Pi) possible in a single experimental session

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

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

    2013-03-05

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

  20. 1H-magnetic resonance spectroscopy screening for animals with acute cerebral infraction suitable for thrombolytic therapy

    Li Yi; Haiou Zhang; Hao Lei; Li Wei

    2007-01-01

    BACKGROUND: As a non-invasive technique which can provide comprehensive biological information, 'H-magnetic resonance spectroscopy ('H-MRS) may provide valuable reference data for irreversible recovery or reversible changes in ischemic tissue after stroke.OBJECTIVE: To monitor and evaluate the effect of the urokinase thrombolytic therapy after experimental acute cerebral ischemia by 'H-MRS technology and investigate its adaptability. DESIGN: Randomly controlled animal study. SETTINGS: Shenzhen Hospital of Peking University and National Key Laboratory of Pattern and Atom & Molecular Physics, Wuhan Physics and Mathematics Institute, Chinese Academy of Science. MATERIALS: Eleven healthy adult Sprague-Dawley (SD) rats, weighing 260 - 300 g and of both genders, were supplied by Experimental Animal Center of Tongji Medical Collage, Huazhong University of Science and Technology [SCXK (e) 2004-007]. 4.7T superconducting nuclear magnetic resonance meter was provided by Brucker Company. METHODS: The experiment was carried out in Shenzhen Hospital of Peking University and National Key Laboratory of Pattern and Atom & Molecular Physics, Wuhan Physics and Mathematics Institute, Chinese Academy of Science from August 2003 to December 2005. ① The rats were randomly divided into 30-minute self-thrombo-embolism group (n =6) and 60-minute self-thrombo-embolism group (n =5). Six rats in 30-minute self-thrombo-embolism group were occluded with clot embolus for 30 minutes and 5 rats in 60-minute self-thrombo-embolism group were occluded for 60 minutes. 10 000 1H/kg urokinase was dissolved in 2 Ml saline and the operation lasted for 5 minutes. ②1H-MRS was performed before thrombolysis and at 3 hours and 24 hours after successful embolization. The metabolic changes of N-acetyl-L-aspartic acid (NAA)/phosphocreatine (PCr) + creatine (Cr), choline phosphate (Cho)/PCr+Cr and lactic acid (Lac)/PCr+Cr in the region of interests were analyzed. ③The T2W image was conducted 24 hours after

  1. Proton magnetic resonance spectroscopy ((1H-MRS reveals geniculocalcarine and striate area degeneration in primary glaucoma.

    Yan Zhang

    Full Text Available BACKGROUND: Glaucoma is a collection of neurodegenerative diseases that affect both the retina and the central visual pathway. We investigated whether metabolites' concentrations changed in the geniculocalcarine (GCT and the striate area of occipital lobe by proton magnetic resonance spectroscopy ((1H-MRS, suggesting neurodegeneration of the central visual pathway in primary glaucoma. METHODOLOGY/PRINCIPAL FINDINGS: 20 patients with glaucoma in both eyes were paired with 20 healthy volunteers in same gender and an age difference less than 3 years. All the participants were examined by MR imaging including T1 Flair, T2 FSE and (1H-MRS. The T1 intensity and T2 intensity of their GCTs and striate areas were measured. The ratio of N-acetylaspartate (NAA/Creatine (Cr, Choline (Cho/Cr, glutamine and glutamate (Glx/Cr were derived by multi-voxels (1H-MRS in the GCT and the striate area of each brain hemisphere. The T1 intensity and T2 intensity had no difference between the groups. Significant decreases in NAA/Cr and Cho/Cr but no difference in Glx/Cr was found between the groups in both the GCT and the striate area. CONCLUSIONS/SIGNIFICANCE: Primary glaucoma affects metabolites' concentrations in the GCT and the striate area suggesting there is ongoing neurodegenerative process.

  2. Glutamatergic system dysfunction in schizophrenia. A proton magnetic resonance spectroscopy (1H MRS) study

    The present study was performed to determine whether there are any differences in metabolite levels as measured by 1 H MRS between chronic and first-episode schizophrenic patients. 17 patients with the diagnosis of chronic schizophrenia and 31 patients with first-episode schizophrenia (ICD-10) were included into the study. The patients were assessed by means of PANSS, CGI and Calgary scales.We also examined 13 healthy persons as control group. MRI and MRS procedures: Proton resonance spectroscopy was performed on a 1,5 MR scanner, PRESS sequence, TR=1500 ms, TE=35 ms, number of repetition=192 and included suppression of water by MOIST sequence. Each volume element (voxel) had dimension of 2x2x2 cm and was localised in the left frontal lobe, in the left temporal lobe and in left thalamus. Complex containing glutamine (Gln), glutamate (Glu) and gamma-aminobutyric acid (GABA) was measured. Ratios of metabolite to creatine and unsuppressed water signal were analysed. We didn't find any significant differences in Glx levels between chronic and first-episode patients and between chronic patients and controls in all studied regions.In the left temporal lobe Glx/Cr ratio was significantly higher in first-episode patients in comparison to controls.We observed significant positive correlation between Glx/Cr level in the left temporal lobe and CGI and PANSS-Negative scores, and negative correlation between Glx/H20 level in the left temporal lobe and PANSS-Positive score. Increased Glx level in the left temporal lobe in first-episode patients suggest that altered glutamatergic activity in this region is present at the onset of disease and doesn't progress over time. (author)

  3. The classification of benign and malignant human prostate tissue by multivariate analysis of {sup 1}H magnetic resonance spectra

    Hahn, P.; Smith, I.; Leboldus, L.; Littman, C.; Somorjai, L.; Bezabeh, T. [Institute for Biodiagnostic, National Research Council, Manitoba (Canada)

    1998-04-01

    {sup 1}H magnetic resonance spectroscopy studies (360 MHz) were performed on specimens of benign (n = 66) and malignant (n = 21) human prostate tissue from 50 patients and the spectral data were subjected to multivariate analysis, specifically linear-discriminant analysis. On the basis of histopathological assessments, an overall classification accuracy of 96.6 % was achieved, with a sensitivity of 100 % and a specificity of 95.5 % in classifying benign prostatic hyperplasia from prostatic cancer. Resonances due to citrate, glutamate, and taurine were among the six spectral subregions identified by our algorithm as having diagnostic potential. Significantly higher levels of citrate were observed in glandular than in stromal benign prostatic hyperplasia (P < 0.05). This method shows excellent promise for the possibility of in vivo assessment of prostate tissue by magnetic resonance. (author)

  4. Non-invasive assessment of hepatic fat accumulation in chronic hepatitis C by {sup 1}H magnetic resonance spectroscopy

    Krssak, Martin [Department of Internal Medicine III, Division of Endocrinology and Metabolism, Medical University of Vienna (Austria); Hofer, Harald [Department of Internal Medicine III, Division of Gastroenterology and Hepatology, Medical University of Vienna (Austria); Wrba, Fritz [Department of Clinical Pathology, Medical University of Vienna (Austria); Meyerspeer, Martin [MR Centre-of-Excellence, Department of Radiodiagnostics, Medical University of Vienna (Austria); Center for Biomedical Engineering and Physics, Medical University of Vienna (Austria); Brehm, Attila [Department of Internal Medicine III, Division of Endocrinology and Metabolism, Medical University of Vienna (Austria); Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center of Diabetes Research and Department of Medicine/Metabolic Diseases, Heinrich Heine University, Duesseldorf (Germany); Lohninger, Alfred [Department of Medical Chemistry, Center for Physiology and Pathophysiology, Medical University of Vienna (Austria); Steindl-Munda, Petra [Department of Internal Medicine III, Division of Endocrinology and Metabolism, Medical University of Vienna (Austria); MR Centre-of-Excellence, Department of Radiodiagnostics, Medical University of Vienna (Austria); Moser, Ewald [MR Centre-of-Excellence, Department of Radiodiagnostics, Medical University of Vienna (Austria); Center for Biomedical Engineering and Physics, Medical University of Vienna (Austria); Ferenci, Peter [Department of Internal Medicine III, Division of Gastroenterology and Hepatology, Medical University of Vienna (Austria); Roden, Michael, E-mail: michael.roden@ddz.uni-duesseldorf.d [Department of Internal Medicine III, Division of Endocrinology and Metabolism, Medical University of Vienna (Austria); Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center of Diabetes Research and Department of Medicine/Metabolic Diseases, Heinrich Heine University, Duesseldorf (Germany)

    2010-06-15

    Background: Liver biopsy is the standard method for diagnosis of hepatic steatosis, but is invasive and carries some risk of morbidity. Aims and methods: Quantification of hepatocellular lipid content (HCL) with non-invasive single voxel {sup 1}H magnetic resonance spectroscopy (MRS) at 3 T was compared with histological grading and biochemical analysis of liver biopsies in 29 patients with chronic hepatitis C. Body mass index, indices of insulin resistance (homeostasis model assessment index, HOMA-IR), serum lipids and serum liver transaminases were also quantified. Results: HCL as assessed by {sup 1}H MRS linearly correlated (r = 0.70, p < 0.001) with histological evaluation of liver biopsies and was in agreement with histological steatosis staging in 65% of the patients. Biochemically assessed hepatic triglyceride contents correlated with HCL measured with {sup 1}H MRS (r = 0.63, p < 0.03) and allowed discriminating between none or mild steatosis versus moderate or severe steatosis. Patients infected with hepatitis C virus genotype 3 had a higher prevalence of steatosis (62%) which was not explained by differences in body mass or whole body insulin resistance. When these patients were excluded from correlation analysis, hepatic fat accumulation positively correlated with insulin resistance in the remaining hepatitis C patients (HCL vs. HOMA-IR, r = 0.559, p < 0.020, n = 17). Conclusion: Localized {sup 1}H MRS is a valid and useful method for quantification of HCL content in patients with chronic hepatitis C and can be easily applied to non-invasively monitoring of steatosis during repeated follow-up measurements in a clinical setting.

  5. IN VIVO 1H MAGNETIC RESONANCE SPECTROSCOPY IN EVALUATION OF HEPATOCELLULAR CARCINOMA AND ITS EARLY RESPONSE TO TRANSCATHETER ARTERIAL CHEMOEMBOLIZATION

    Bin Wu; Wei-jun Peng; Pei-jun Wang; Ya-jia Gu; Wen-tao Li; Liang-pin Zhou; Feng Tang; Guo-ming Zhong

    2006-01-01

    Objective To investigate the value of in vivo proton magnetic resonance spectroscopy (MRS) in the assessment of hepatocellular carcinoma (HCC) and monitor its metabolic change shortly after transcatheter arterial chemoembolization (TACE).Methods In this prospective study,28 consecutive patients with large HCC (≥3 cm in diameter) confirmed by fine needle aspiration biopsy were recruited.The 1H MRS of all hepatic lesions and some uninvolved liver parenchyma were performed with 1.5T whole body MR scanner.Among them,15 cases were evaluated again about one week after TACE.The main metabolites such as choline and lipid before and after interventional therapy were measured to assess the early response of the tumor.Results The technical success rate of 1H MRS in liver was high (33/41,80%),closely related to breath motion,location of lesion,and size of voxel.In spectra,the choline compound peak of HCC elevated compared with uninvolved liver parenchyma.After TACE,both the amplitude and the area of choline resonance peak significantly descended (choline-to-lipid ratios from 0.352±0.080 to 0.167±0.030,P=0.026;from 0.205±0.060 to 0.070±0.020,P=0.042,respectively);yet lipid resonance peak ascended.Conclusions In vivo 1H MRS is technically feasible for the evaluation of large focal hepatic lesions,however,the reproducibility and stability are not as good as routine MR scan.1H MRS can monitor the early stage metabolic changes of HCC after TACE but limitation like quantification still exists.

  6. The use of dynamic nuclear polarization in 1H and 13C solid state NMR

    The Dynamic Nuclear Polarization (DNP) effect is used at room temperature in combination with 13C NMR. Due to the low natural abundance of 13C spins (1%) the signal is very weak, but when the DNP effect is used the 13C signal can be enhanced and therefore the number of scans and the measuring time considerably reduced. The theory is presented and the experimental set-up is described. Experiments on polystyrene, artificially doped with free radicals are described and it is examined whether the theory of the DNP effect can be used in a quantitative way. Applications of the use of the DNP effect in 13C NMR are shown. Excellent spectra are presented of artificial and natural diamonds, possibly to be used for diamond characterization purposes. 161 refs.; 61 figs.; 3 tabs

  7. The search for negative amplitude components in quasi-continuous distributions of relaxation times: the example of 1H magnetization exchange in articular cartilage and hydrated collagen

    When inverting nuclear magnetic resonance relaxation data in order to obtain quasi-continuous distributions of relaxation times for fluids in porous media, it is common practice to impose a non-negative (NN) constraint on the distributions. While this approach can be useful in reducing the effects of data distortion and/or preventing wild oscillations in the distributions, it may give misleading results in the presence of real negative amplitude components. Here, some examples of valid negative components for articular cartilage and hydrated collagen are given. Articular cartilage is a connective tissue, consisting mainly of collagen, proteoglycans and water, which can be considered, in many aspects, as a porous medium. Separate T1 relaxation data are obtained for low-mobility ('solid') macromolecular 1H and for higher-mobility ('liquid') 1H by the separation of these components in free induction decays, with α denoting the solid/liquid 1H ratio. When quasi-continuous distributions of relaxation times (T1) of the solid and liquid signal components of cartilage or collagen are computed from experimental relaxation data without imposing the usual NN constraint, valid negative peaks may appear. The features of the distributions, in particular negative peaks, and the fact that peaks at longer times for macromolecular and water protons are at essentially the same T1, are interpreted as the result of a magnetization exchange between these two spin pools. For the only-slightly-hydrated collagen samples, with α>1, the exchange leads to small negative peaks at short T1 times for the macromolecular component. However, for the cartilage, with substantial hydration or for a strongly hydrated collagen sample, both with α1H ratio, α. The solid-to-liquid exchange times are found to be in the range from 10 ms to a few tens of ms at all hydration levels. The results may be of interest for the application of magnetization exchange contrast in the imaging of articular cartilage

  8. Nuclear Current and Magnetic Rotation

    PENG Jing; XING Li-Feng

    2009-01-01

    The magnetic rotational bands based on the configuration πh211/2 ⊕Vh-211/2 in 142 Gd are investigated with the newly developed tilted axis cranking relativistic mean field (RMF) theory with and without nuclear current.The effect of the nuclear current is discussed by comparing the total Routhians,single particle levels,electromagnetic transition probabilities B(M1) and B(E2) in self-consistent tilted axis cranking RMF calculation with those obtained without the nuclear current.The nuclear currents are found to play an important role in the magnetic rotation of nuclei.

  9. 1H magnetic resonance spectroscopy of urine for the assessment of renal dysfunction in healthy pregnant women

    Background. Pregnancy is associated with adaptive alterations affecting almost all organs and systems of the female body and is also a time when pathologies appear which would otherwise remain asymptomatic for many years. 1H Magnetic Resonance Spectroscopy (1H-MRS) of urine, a modern diagnostic method, can disclose discrete changes in organ function. It seemed interesting to search for pregnancy-dependent renal pathology in healthy women and thus prognosticate progression to overt disease after pregnancy. Objectives. To determine whether physiological pregnancy is accompanied by alterations in renal structures detectable by 1H-MRS of urine and to assess the type and reversibility of alterations. Material and Methods. Eighty women were enrolled in two groups: a study group (B) consisting of 40 healthy pregnant women and a control group (K) of 40 healthy nulligravida women. Enrollment criteria included normal health status, unrevealing physical and gynecological examination, and normal results of laboratory tests (complete blood count, urea, creatinine, uric acid, urinalysis). MRS of urine and laboratory tests were done in group B during each trimester (B1, B2, and B3, i.e. the 1st, 2nd, and 3rd trimesters, respectively) and six weeks after delivery (BP). In group K, the tests were done only once. The spectra were processed with MestReC software and then multidimensional statistical analysis using Unscrambler software was performed. The results were presented as the distribution of the variables in multidimensional space. Results. The patterns in multidimensional space revealed a clustering of points when comparing the first and third trimesters of pregnancy and comparing the third trimester and the healthy non-pregnant women. Also, a partial clustering of points comparing healthy non-pregnant and pregnant women after the puerperium was noticeable. Conclusions. Differences in 1H-MRS profiles of urine between healthy pregnant and non-pregnant women reflect alterations

  10. Evaluation of invasiveness of astrocytoma using {sup 1}H-magnetic resonance spectroscopy: correlation with expression of matrix metalloproteinase-2

    Zhang, Kai; Li, Chuanfu; Ma, Xiangxing; Meng, Xiangshui; Feng, Dechao [Shandong University, Department of Radiology, Qilu Hospital, Jinan (China); Liu, Ying [Shandong University, Department of Radiology, Qilu Hospital, Jinan (China); Anhui Provincial Hospital, MRI Department, Hefei (China); Li, Li [Shandong University, Department of Pathology, Qilu Hospital, Jinan (China)

    2007-11-15

    Even low-grade astrocytomas infiltrate the entire brain, a feature that precludes their successful therapy. So to assess the invasive potential of astrocytoma is very important. The aim of this study was determine whether there is a significant correlation between the results of {sup 1}H-magnetic resonance spectroscopy ({sup 1}H-MRS) and tumor invasive potential of astrocytoma, which is reflected by expression of matrix metalloproteinase-2 (MMP-2). The {sup 1}H-MRS spectra of 41 histologically verified astrocytomas were obtained on a 3-T MR scanner. According to the World Health Organization classification criteria for central nervous system tumors, there were 16 low-grade astrocytomas (2 pilocytic astrocytomas, 14 grade II astrocytomas) and 25 high-grade astrocytomas (5 anaplastic astrocytomas, 20 glioblastomas).The choline/N-acetylaspartate (Cho/NAA) and choline/creatine (Cho/Cr) ratios were calculated. Of the 41 astrocytomas, 19 (8 low-grade and 11 high-grade) were analyzed immunohistochemically. Expression of MMP-2 was determined using streptavidin-peroxidase complex (SP) staining which was quantified by calculating its calibrated opacity density (COD) using an image analysis system. The correlations between metabolite ratios and the quantitative data from the immunohistochemical tests in the 19 astrocytomas were determined. The Cho/NAA and Cho/Cr ratios of high-grade astrocytoma were both significantly greater than those of low-grade astrocytoma (t = -6.222, P = 0.000; t = -6.533, P = 0.000, respectively). MMP-2 COD values of high-grade astrocytomas were also significantly greater than those of low-grade astrocytomas (t = -5.892, P = 0.000). There were strong positive correlations between Cho/NAA ratio and MMP-2 COD (r = 0.669, P = 0.002), and between Cho/Cr ratio and MMP-2 COD (r = 0.689, P = 0.001). {sup 1}H-MRS is helpful in evaluating the invasiveness of astrocytomas and predicting prognosis preoperatively by determining the Cho/NAA and Cho/Cr ratios

  11. Evaluation of invasiveness of astrocytoma using 1H-magnetic resonance spectroscopy: correlation with expression of matrix metalloproteinase-2

    Even low-grade astrocytomas infiltrate the entire brain, a feature that precludes their successful therapy. So to assess the invasive potential of astrocytoma is very important. The aim of this study was determine whether there is a significant correlation between the results of 1H-magnetic resonance spectroscopy (1H-MRS) and tumor invasive potential of astrocytoma, which is reflected by expression of matrix metalloproteinase-2 (MMP-2). The 1H-MRS spectra of 41 histologically verified astrocytomas were obtained on a 3-T MR scanner. According to the World Health Organization classification criteria for central nervous system tumors, there were 16 low-grade astrocytomas (2 pilocytic astrocytomas, 14 grade II astrocytomas) and 25 high-grade astrocytomas (5 anaplastic astrocytomas, 20 glioblastomas).The choline/N-acetylaspartate (Cho/NAA) and choline/creatine (Cho/Cr) ratios were calculated. Of the 41 astrocytomas, 19 (8 low-grade and 11 high-grade) were analyzed immunohistochemically. Expression of MMP-2 was determined using streptavidin-peroxidase complex (SP) staining which was quantified by calculating its calibrated opacity density (COD) using an image analysis system. The correlations between metabolite ratios and the quantitative data from the immunohistochemical tests in the 19 astrocytomas were determined. The Cho/NAA and Cho/Cr ratios of high-grade astrocytoma were both significantly greater than those of low-grade astrocytoma (t = -6.222, P = 0.000; t = -6.533, P = 0.000, respectively). MMP-2 COD values of high-grade astrocytomas were also significantly greater than those of low-grade astrocytomas (t = -5.892, P 0.000). There were strong positive correlations between Cho/NAA ratio and MMP-2 COD (r = 0.669, P = 0.002), and between Cho/Cr ratio and MMP-2 COD (r = 0.689, P = 0.001). 1H-MRS is helpful in evaluating the invasiveness of astrocytomas and predicting prognosis preoperatively by determining the Cho/NAA and Cho/Cr ratios. (orig.)

  12. Nuclear Bag Model and Nuclear Magnetic Moments

    Liu, Liang-Gang

    1999-01-01

    In 1991, we proposed a model in which nucleus is treated as a spherical symmetric MIT bag and nucleon satisfies the MIT bag model boundary condition. The model was employed to calculate nuclear magnetic moments. The results are in good agreement with experiment data. Now, we found this model is still interesting and illuminating.

  13. Absolute hydrogen depth profiling using the resonant $^{1}$H($^{15}$N,$\\alpha\\gamma$)$^{12}$C nuclear reaction

    Reinhardt, Tobias P; Bemmerer, Daniel; Stöckel, Klaus; Wagner, Louis

    2016-01-01

    Resonant nuclear reactions are a powerful tool for the determination of the amount and profile of hydrogen in thin layers of material. Usually, this tool requires the use of a standard of well-known composition. The present work, by contrast, deals with standard-less hydrogen depth profiling. This approach requires precise nuclear data, e.g. on the widely used $^{1}$H($^{15}$N,$\\alpha\\gamma$)$^{12}$C reaction, resonant at 6.4\\,MeV $^{15}$N beam energy. Here, the strongly anisotropic angular distribution of the emitted $\\gamma$-rays from this resonance has been re-measured, resolving a previous discrepancy. Coefficients of (0.38$\\pm$0.04) and (0.80$\\pm$0.04) have been deduced for the second and fourth order Legendre polynomials, respectively. In addition, the resonance strength has been re-evaluated to (25.0$\\pm$1.5)\\,eV, 10\\% higher than previously reported. A simple working formula for the hydrogen concentration is given for cases with known $\\gamma$-ray detection efficiency. Finally, the absolute approach i...

  14. Absolute hydrogen depth profiling using the resonant 1H(15N, αγ)12C nuclear reaction

    Reinhardt, Tobias P.; Akhmadaliev, Shavkat; Bemmerer, Daniel; Stöckel, Klaus; Wagner, Louis

    2016-08-01

    Resonant nuclear reactions are a powerful tool for the determination of the amount and profile of hydrogen in thin layers of material. Usually, this tool requires the use of a standard of well-known composition. The present work, by contrast, deals with standard-less hydrogen depth profiling. This approach requires precise nuclear data, e.g. on the widely used 1 H(15 N, αγ)12 C reaction, resonant at 6.4 MeV 15 N beam energy. Here, the strongly anisotropic angular distribution of the emitted γ -rays from this resonance has been re-measured, resolving a previous discrepancy. Coefficients of (0.38 ± 0.04) and (0.80 ± 0.04) have been deduced for the second and fourth order Legendre polynomials, respectively. In addition, the resonance strength has been re-evaluated to (25.0 ± 1.5) eV, 10% higher than previously reported. A simple working formula for the hydrogen concentration is given for cases with known γ -ray detection efficiency. Finally, the absolute approach is illustrated using two examples.

  15. Brain temperature measured by 1H-magnetic resonance spectroscopy in acute and subacute carbon monoxide poisoning

    Brain temperature (BT) is associated with the balance between cerebral blood flow and metabolism according to the ''heat-removal'' theory. The present study investigated whether BT is abnormally altered in acute and subacute CO-poisoned patients by using 1H-magnetic resonance spectroscopy (MRS). Eight adult CO-poisoned patients underwent 3-T magnetic resonance imaging in the acute and subacute phases after CO exposure. MRS was performed on deep cerebral white matter in the centrum semiovale, and MRS-based BT was estimated by the chemical shift difference between water and the N-acetyl aspartate signal. We defined the mean BT + 1.96 standard deviations of the BT in 15 healthy controls as the cutoff value for abnormal BT increases (p < 0.05) in CO-poisoned patients. BT of CO-poisoned patients in both the acute and subacute phases was significantly higher than that of the healthy control group. However, BT in the subacute phase was significantly lower than in the acute phase. On the other hand, no significant difference in body temperature was observed between acute and subacute CO-poisoned patients. BT weakly correlated with body temperature, but this correlation was not statistically significant (rho = 0.304, p = 0.2909). The present results suggest that BT in CO-poisoned patients is abnormally high in the acute phase and remains abnormal in the subacute phase. BT alteration in these patients may be associated with brain perfusion and metabolism rather than other factors such as systemic inflammation and body temperature. (orig.)

  16. Brain temperature measured by {sup 1}H-magnetic resonance spectroscopy in acute and subacute carbon monoxide poisoning

    Fujiwara, Shunrou; Nishimoto, Hideaki; Murakami, Toshiyuki; Ogawa, Akira; Ogasawara, Kuniaki [Iwate Medical University, Department of Neurosurgery, Morioka, Iwate (Japan); Yoshioka, Yoshichika [Osaka University, Laboratory of Biofunctional Imaging, WPI Immunology Frontier Research Center, Osaka (Japan); Matsuda, Tsuyoshi [MR Applications and Workflow Asia Pacific, GE Healthcare Japan, Tokyo (Japan); Beppu, Takaaki [Iwate Medical University, Department of Neurosurgery, Morioka, Iwate (Japan); Iwate Medical University, Department of Hyperbaric Medicine, Iwate (Japan)

    2016-01-15

    Brain temperature (BT) is associated with the balance between cerebral blood flow and metabolism according to the ''heat-removal'' theory. The present study investigated whether BT is abnormally altered in acute and subacute CO-poisoned patients by using {sup 1}H-magnetic resonance spectroscopy (MRS). Eight adult CO-poisoned patients underwent 3-T magnetic resonance imaging in the acute and subacute phases after CO exposure. MRS was performed on deep cerebral white matter in the centrum semiovale, and MRS-based BT was estimated by the chemical shift difference between water and the N-acetyl aspartate signal. We defined the mean BT + 1.96 standard deviations of the BT in 15 healthy controls as the cutoff value for abnormal BT increases (p < 0.05) in CO-poisoned patients. BT of CO-poisoned patients in both the acute and subacute phases was significantly higher than that of the healthy control group. However, BT in the subacute phase was significantly lower than in the acute phase. On the other hand, no significant difference in body temperature was observed between acute and subacute CO-poisoned patients. BT weakly correlated with body temperature, but this correlation was not statistically significant (rho = 0.304, p = 0.2909). The present results suggest that BT in CO-poisoned patients is abnormally high in the acute phase and remains abnormal in the subacute phase. BT alteration in these patients may be associated with brain perfusion and metabolism rather than other factors such as systemic inflammation and body temperature. (orig.)

  17. 1H and 31P magnetic resonance spectroscopic imaging of white matter signal hyperintensity areas in elderly subjects

    White matter signal hyperintensities (WMSH) are commonly seen on MRI of elderly subjects. The purpose of this study was to characterize metabolic changes in the white matter of elderly subjects with extensive WMSH. We used water-suppressed proton (1H) magnetic resonance spectroscopic imaging (MRSI) to compare six subjects with extensive WMSH with eight age-matched elderly subjects with minimal or absent WMSH, and phosphorus (31P) MRSI to compare nine subjects with extensive WMSH and seven age-matched elderly subjects without extensive WMSH. Relative to region-matched tissue in elderly controls, extensive WMSH were associated with increased signal from choline-containing metabolites, no significant change of signal from N-acetylaspartate, and a trend to a decreased phosphomonoester (PME) resonance. These findings suggest that WMSH may be associated with an alteration of brain myelin phospholipids in the absence of axonal damage. There were no differences in energy phosphates, consistent with lack of ongoing brain ischemia. Within the group with extensive WMSH, PME resonance measures were significantly lower in WMSH than in contralateral normal-appearing white matter. These results provide information on pathophysiology of WMSH and a basis for comparison with WMSH in Alzheimer's disease, vascular dementia, multiple sclerosis, and other diseases. (orig.). With 4 figs., 4 tabs

  18. Computer Assisted Instruction (Cain) For Nuclear Magnetic Resonance Spectroscopy

    A computer assisted instruction program for nuclear magnetic resonance spectroscopy was developed by using Author ware 5.0, Adobe Image Styler 1.0, Adobe Photo shop 7.0 and Flash MX. The contents included the basic theory of 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, the instrumentation of NMR spectroscopy, the two dimensional (2D) NMR spectroscopy and the interpretation of NMR spectra. The program was also provided examples, and exercises, with emphasis on NMR spectra interpretation to determine the structure of unknown compounds and solutions for self study. The questionnaire from students showed that they were very satisfied with the software

  19. Thin film hydrogen depth profiling using the 1H(15N,αγ)12C nuclear reaction

    An analytical method for hydrogen depth profiling in materials has been developped using the 1H(15N,αγ) nuclear reaction. Without elemental interferences less than 1014 at/cm2, are detectable in the surface layer, the lowest in depth concentration range reaching easily 0,1 at. %. Moreover concentration profiles obtained in a non-destructive manner have a typical depth resolution ranging from approximately 50 A at the surface to approximately 400 A to a 8000 A depth, the analyzing depth being at least one micron. Such an analytical tool has required the development of a multiply charged ion source and a specially designed irradiation-detection system. Two important physical phenomena have been investigated regarding their connection to the analysis. The first one deals with the evolution of the hydrogen attached to the surface in function of the bombarding ion dose. Such variations have been interpreted in the frame of a model based on adsorption and radiolysis of the hydrogen species under beam impact, allowing related cross sections to be extracted. A remarkable agreement with the experimental results is pointed out. The second phenomenon in depth hydrogen departure under beam impact, is fortunately not so systematic. From various correlations it apears that ionisation of weakly bound hydrogen is responsible for the observed effect but one cannot so infer of the destructive character of the method

  20. The search for negative amplitude components in quasi-continuous distributions of relaxation times: the example of {sup 1}H magnetization exchange in articular cartilage and hydrated collagen

    Fantazzini, Paola; Galassi, Francesca [Department of Physics, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna (Italy); Bortolotti, Villiam [Department of DICAM, University of Bologna, Viale del Risorgimento 2, 40136 Bologna (Italy); Brown, Robert J S [953 West Bonita Avenue, Claremont, CA 91711-4193 (United States); Vittur, Franco, E-mail: paola.fantazzini@unibo.it [Department of Life Sciences, University of Trieste, via Giorgeri 1, 24137 (Italy)

    2011-06-15

    When inverting nuclear magnetic resonance relaxation data in order to obtain quasi-continuous distributions of relaxation times for fluids in porous media, it is common practice to impose a non-negative (NN) constraint on the distributions. While this approach can be useful in reducing the effects of data distortion and/or preventing wild oscillations in the distributions, it may give misleading results in the presence of real negative amplitude components. Here, some examples of valid negative components for articular cartilage and hydrated collagen are given. Articular cartilage is a connective tissue, consisting mainly of collagen, proteoglycans and water, which can be considered, in many aspects, as a porous medium. Separate T{sub 1} relaxation data are obtained for low-mobility ('solid') macromolecular {sup 1}H and for higher-mobility ('liquid') {sup 1}H by the separation of these components in free induction decays, with {alpha} denoting the solid/liquid {sup 1}H ratio. When quasi-continuous distributions of relaxation times (T{sub 1}) of the solid and liquid signal components of cartilage or collagen are computed from experimental relaxation data without imposing the usual NN constraint, valid negative peaks may appear. The features of the distributions, in particular negative peaks, and the fact that peaks at longer times for macromolecular and water protons are at essentially the same T{sub 1}, are interpreted as the result of a magnetization exchange between these two spin pools. For the only-slightly-hydrated collagen samples, with {alpha}>1, the exchange leads to small negative peaks at short T{sub 1} times for the macromolecular component. However, for the cartilage, with substantial hydration or for a strongly hydrated collagen sample, both with {alpha}<<1, the behavior is reversed, with a negative peak for water at short times. The validity of a negative peak may be accepted (dismissed) by a high (low) cost of NN in error of fit

  1. Nuclear magnetic gamma double resonance

    A number of problems corresponding to different variants of experiments using nuclear magnetic-gamma double resonance (NMGDR) are theoretically investigated. Calculation is carried out and its results are compared to experimental ones concerning NMGDR for tantalum. Time dynamics of the source or scatterer nucleus sublevel populations under double resonance conditions with non-uniform initial population of this nucleus sublevels is studied

  2. Nuclear magnetic resonance characterization of apple juice containing enzyme preparations

    In this work, 1H nuclear magnetic resonance (1H NMR) was employed to evaluate changes in apple juice in response to the addition of Panzym Yieldmash and Ultrazym AFP-L enzymatic complexes and compare it with premium apple juice. The juice was processed at different temperatures and concentrations of enzymatic complexes. The differences in the results were attributed mainly to the enzyme concentrations, since temperature did not cause any variation. A quantitative analysis indicated that the concentration of fructose increased while the concentrations of sucrose and glucose decreased in response to increasing concentrations of the enzymatic complexes. (author)

  3. Magnetometer of nuclear magnetic resonance

    We present a nuclear magnetic resonance magnetometer that measures magnetic fields, between 2,500 gauss and 5,000 gauss, with an accuracy of a few parts per million. The circuit of the magnetometer, based on a marginal oscillator, permits a continuous tunning in the frequency range comprised between 10.0 MHz, with a signal to noise ratio of about 20. The radiofrequency amplifier is of the cascode type in integrated circuit and it operates with two 9V batteries. The modulation is at 35 Hz and it is provided by an external oscillator. The instrument is compact, inexpensive and easy to operate; it can also be used for didactic purposes to show the phenomenon of magnetic nuclear resonance and its main characteristics. (author)

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

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

    2011-01-01

    Bevacizumab shows unprecedented rates of response in recurrent glioblastomas (GBM), but the detailed mechanisms are still unclear. We employed in vivo magnetic resonance spectroscopic imaging (MRSI) and quantitative magnetic resonance imaging to investigate whether bevacizumab alters oxygen and energy metabolism and whether this effect has antitumoral activity in recurrent GBM. 31P and 1H MRSI, apparent diffusion coefficient (ADC), and high-resolution T2 and T2′ mapping (indirect marker of ox...

  5. γ-Fe2O3:A magnetic separable catalyst for synthesis of 5-substituted 1H-tetrazoles from nitriles and sodium azide

    Gang Qi; Yong Dai

    2010-01-01

    An efficient route for the synthesis of 5-substituted 1H-tetrazole via[2+3]cycloaddition of nitriles and sodium azide is reported using γ-Fe2O3 nanoparticles as a magnetic separable catalyst.Under optimized conditions,the moderate to good yields(71-95%)can be obtained.The catalyst can be easily separated by a magnet and reused for several circles.

  6. Quantitative {sup 1}H and hyperpolarized {sup 3}He magnetic resonance imaging: Comparison in chronic obstructive pulmonary disease and healthy never-smokers

    Owrangi, Amir M., E-mail: aowrangi@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Graduate Program in Biomedical Engineering, The University of Western Ontario, London (Canada); Wang, Jian X., E-mail: jxwang@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Applied Science Laboratories, General Electric Healthcare (Canada); Wheatley, Andrew, E-mail: awheat@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); McCormack, David G., E-mail: David.Mccormack@lhsc.on.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Division of Respirology, Department of Medicine, The University of Western Ontario, London (Canada); Parraga, Grace, E-mail: gparraga@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Graduate Program in Biomedical Engineering, The University of Western Ontario, London (Canada); Department of Medical Imaging, The University of Western Ontario, London (Canada); Department of Medical Biophysics, The University of Western Ontario, London (Canada)

    2014-01-15

    Objective: The aim of this study was to quantitatively evaluate the relationship between short echo time pulmonary {sup 1}H magnetic resonance imaging (MRI) signal intensity (SI) and {sup 3}He MRI apparent diffusion coefficients (ADC), high-resolution computed tomography (CT) measurements of emphysema, and pulmonary function measurements. Materials and methods: Nine healthy never-smokers and 11 COPD subjects underwent same-day plethysmography, spirometry, short echo time ((TE) = 1.2 ms) {sup 1}H and diffusion-weighted hyperpolarized {sup 3}He MRI (b = 1.6 s/cm{sup 2}) at 3.0 T. In addition, for COPD subjects only, CT densitometry was also performed. Results: Mean {sup 1}H SI was significantly greater for never-smokers (12.1 ± 1.1 arbitrary units (AU)) compared to COPD subjects (10.9 ± 1.3 AU, p = 0.04). The {sup 1}H SI AP-gradient was also significantly greater for never-smokers (0.40 AU/cm, R{sup 2} = 0.94) compared to COPD subjects (0.29 AU/cm, R{sup 2} = 0.968, p = 0.05). There was a significant correlation between {sup 1}H SI and {sup 3}He ADC (r = −0.58, p = 0.008) and significant correlations between {sup 1}H MR SI and CT measurements of emphysema (RA{sub 950}, r = −0.69, p = 0.02 and HU{sub 15}, r = 0.66, p = 0.03). Conclusions: The significant and moderately strong relationship between {sup 1}H SI and {sup 3}He ADC, as well as between {sup 1}H SI and CT measurements of emphysema suggests that these imaging methods and measurements may be quantifying similar tissue changes in COPD and that pulmonary {sup 1}H SI may be used to monitor emphysema as a complement to CT and noble gas MRI.

  7. Quantitative 1H and hyperpolarized 3He magnetic resonance imaging: Comparison in chronic obstructive pulmonary disease and healthy never-smokers

    Objective: The aim of this study was to quantitatively evaluate the relationship between short echo time pulmonary 1H magnetic resonance imaging (MRI) signal intensity (SI) and 3He MRI apparent diffusion coefficients (ADC), high-resolution computed tomography (CT) measurements of emphysema, and pulmonary function measurements. Materials and methods: Nine healthy never-smokers and 11 COPD subjects underwent same-day plethysmography, spirometry, short echo time ((TE) = 1.2 ms) 1H and diffusion-weighted hyperpolarized 3He MRI (b = 1.6 s/cm2) at 3.0 T. In addition, for COPD subjects only, CT densitometry was also performed. Results: Mean 1H SI was significantly greater for never-smokers (12.1 ± 1.1 arbitrary units (AU)) compared to COPD subjects (10.9 ± 1.3 AU, p = 0.04). The 1H SI AP-gradient was also significantly greater for never-smokers (0.40 AU/cm, R2 = 0.94) compared to COPD subjects (0.29 AU/cm, R2 = 0.968, p = 0.05). There was a significant correlation between 1H SI and 3He ADC (r = −0.58, p = 0.008) and significant correlations between 1H MR SI and CT measurements of emphysema (RA950, r = −0.69, p = 0.02 and HU15, r = 0.66, p = 0.03). Conclusions: The significant and moderately strong relationship between 1H SI and 3He ADC, as well as between 1H SI and CT measurements of emphysema suggests that these imaging methods and measurements may be quantifying similar tissue changes in COPD and that pulmonary 1H SI may be used to monitor emphysema as a complement to CT and noble gas MRI

  8. Nuclear Magnetic Resonance Imaging of Li-ion Battery

    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.

  9. Evanescent Waves Nuclear Magnetic Resonance

    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. Tomography by nuclear magnetic resonance

    Imaging methods based on nuclear magnetic resonance allow the production of sectional images of the human body without ionizing radiation. It is possible to measure the density and relaxation times of the water protons in body fluids or tissue. This allows not only to obtain morphological information but also to get some insight into the spatial distribution of physiological data. Starting with a review of the principles of nuclear magnetic resonance it is explained how the measured signal can be associated with an image point; it is also explained what type of apparatus is necessary and what the physical limitations are. Possible risks the patient may be exposed to in an examination using nuclear magnetic resonance are discussed. The present state of the technical development enables the production of whole-body sectional images of a living person within about one minute. By means of some typical examples the nature and properties of these images are explained. Although extensive clinical studies will be necessary before a more general assessment can be made of this method, an outlook is provided on expected further developments and possible future fields of application. (orig.)

  11. Analysis of metabolites in human brain tumors and cerebral infarctions using 31P- and 1H-magnetic resonance spectroscopy

    31P- and 1H-MRS with a 2.0 tesla MRI/S system was used to monitor the cerebral energy levels, phospholipid metabolism, intracellular pH, and lactate and amino acid levels in patients with brain tumors and cerebral infarctions. Studies of human brain tumors have suggested that the 31P-MRS of malignant brain tumors show low concentrations of phosphocreatine (PCr) and β-ATP, high levels of phosphomonoester (PME) and inorganic Pi, and an alkaline pH. The Pi, PME, and intracellular pH of malignant lymphoma were higher than those of other brain tumors. 1H-MRS showed an increase of lactate in malignant brain tumors and epidermoids. After ACNU administration, the tumor 31P-MRS showed transient reduction and elevation of Pi on five patients with malignant gliomas. Intracellular pH also showed a transient reduction during radiotherapy. 1H-MRS showed a reduction of lactate at the beginning of therapy and showed a marked re-elevation of lactate with tumor regrowth. After radiotherapy, the normal brain 31P-MRS showed transient elevation and reduction of Pi. Intracellular pH also showed a transient elevation during radiotherapy. To investigate the mechanism of hyperbaric oxygen therapy (HBO) in cerebral ischemia, changes of brain lactate level were estimated by 1H-MRS. Although the Lactate/Creatine ratio decreased consistently over time in all patients, it decreased more rapidly in the patients receiving HBO therapy than in those without such therapy. 1H-MRS demonstrated that HBO therapy may improve metabolism in the ischemic brain and reduces the lactate levels. 31P- and 1H-MRS are practical tools for the clinical analysis of cerebral disorders as well as for deciding on therapeutic procedures and evaluating the response. (K.H.)

  12. Tracing bacterial metabolism using multi-nuclear (1H, 2H, and 13C) Solid State NMR: Realizing an Idea Initiated by James Scott

    Cody, G.; Fogel, M. L.; Jin, K.; Griffen, P.; Steele, A.; Wang, Y.

    2011-12-01

    Approximately 6 years ago, while at the Geophysical Laboratory, James Scott became interested in the application of Solid State Nuclear Magnetic Resonance Spectroscopy to study bacterial metabolism. As often happens, other experiments intervened and the NMR experiments were not pursued. We have revisited Jame's question and find that using a multi-nuclear approach (1H, 2H, and 13C Solid State NMR) on laboratory cell culture has some distinct advantages. Our experiments involved batch cultures of E. coli (MG1655) harvested at stationary phase. In all experiments the growth medium consisted of MOPS medium for enterobacteria, where the substrate is glucose. In one set of experiments, 10 % of the water was D2O; in another 10 % of the glucose was per-deuterated. The control experiment used both water and glucose at natural isotopic abundance. A kill control of dead E. coli immersed in pure D2O for an extended period exhibited no deuterium incorporation. In both deuterium enriched experiments, considerable incorporation of deuterium into E. coli's biomolecular constituents was detected via 2H Solid State NMR. In the case of the D2O enriched experiment, 58 % of the incorporated deuterium is observed in a sharp peak at a frequency of 0.31 ppm, consistent with D incorporation in the cell membrane lipids, the remainder is observed in a broad peak at a higher frequency (centered at 5.4 ppm, but spanning out to beyond 10 ppm) that is consistent with D incorporation into predominantly DNA and RNA. In the case of the D-glucose experiments, 61 % of the deuterium is observed in a sharp resonance peak at 0.34 ppm, also consistent with D incorporation into membrane lipids, the remainder of the D is observed at a broad resonance peak centered at 4.3 ppm, consistent with D enrichment in glycogen. Deuterium abundance in the E. coli cells grown in 10 % D2O is nearly 2X greater than that grown with 10 % D-glucose. Very subtle differences are observed in both the 1H and 13C solid

  13. Wide-range nuclear magnetic resonance detector

    Sturman, J. C.; Jirberg, R. J.

    1972-01-01

    Compact and easy to use solid state nuclear magnetic resonance detector is designed for measuring field strength to 20 teslas in cryogenically cooled magnets. Extremely low noise and high sensitivity make detector applicable to nearly all types of analytical nuclear magnetic resonance measurements and can be used in high temperature and radiation environments.

  14. Analysis of Brain Metabolism by Proton-Magnetic-Resonance-Spectroscopy (1H-MRS) in Attention-Deficit/Hyperactivity Disorder Suggests a Generalized Differential Ontogenic Pattern from Controls

    Arcos-Burgos, Mauricio; Londoño, Ana C.; DAVID A PINEDA; Lopera, Francisco; Palacio, Juan David; Arbelaez, Andres; Acosta, Maria T.; Vélez, Jorge I.; Castellanos, Francisco Xavier; Muenke, Maximilian

    2012-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is the most common behavioral disorder of childhood. Preliminary studies with proton magnetic resonance spectroscopy (1HMRS) of the brain have reported differences in brain metabolite concentration-to-Cr ratios between individuals with ADHD and unaffected controls in several frontal brain regions including anterior cingulate cortex. Using multivoxel 1H-MRS, we compared 14 individuals affected with ADHD to 20 individuals without ADHD from the sam...

  15. Reduction in temporal N-acetylaspartate and creatine (or choline) ratio in temporal lobe epilepsy: does this 1H-magnetic resonance spectroscopy finding mean poor seizure control?

    Mendes-Ribeiro, J.; Soares, R.,; Simoes-Ribeiro, F.; Guimaraes, M

    1998-01-01

    BACKGROUND—Proton magnetic resonance spectroscopy (1H-MRS) is a potentially useful tool in the in vivo investigation of brain metabolites in intractable temporal lobe epilepsy (TLE). Focal N-acetylaspartatate (NAA) reductions have been correlated with mesial temporal sclerosis (MTS) in surgically resected epileptogenic foci.
OBJECTIVE—To evaluate the abnormalities in the metabolites NAA, creatine+ phosphocreatine (Cr), and choline containing compounds (Cho) in the tempora...

  16. Evanescent Waves Nuclear Magnetic Resonance.

    Halidi, El Mohamed; Nativel, Eric; Akel, Mohamad; Kenouche, Samir; Coillot, Christophe; Alibert, Eric; Jabakhanji, Bilal; Schimpf, Remy; Zanca, Michel; Stein, Paul; Goze-Bac, Christophe

    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 characterize and model evanescent electromagnetic fields originating from NMR phenomenon. We report that in this experimental configuration the available NMR signal is one order of magnitude larger and follows an exponential decay inversely proportional to the size of the emitters. Those investigations open a new road to a better understanding of the evanescent waves component in NMR with the opportunity to perform localized spectroscopy and imaging. PMID:26751800

  17. Nuclear magnetic ordering in silver

    Nuclear antiferromagnetic ordering has been observed by neutron diffraction in a single crystal of 109Ag. The critical temperature is found to 700 pK, and the critical field is 100 μT. 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

  18. Nuclear magnetic ordering in silver

    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.

  19. 1H magnetic resonance spectroscopy and diffusion weighted imaging findings of medulloblastoma in 3.0T MRI A retrospective analysis of 17 cases

    Guangyao Wu; Haopeng Pang; Prasanna Ghimire; Guobing Liu

    2012-01-01

    1H magnetic resonance spectroscopy and diffusion weighted imaging features of the cerebellar vermis in 17 medulloblastoma patients were retrospectively analyzed, and 17 healthy volunteers were selected as controls. 1H magnetic resonance spectroscopy showed that in all 17 medulloblastoma patients, N-acetyl aspartate and creatine peaks were significantly decreased, the choline peak was significantly increased, and there was evidence of a myo-inositol peak. Further, 11 patients showed a low taurine peak at 3.4 ppm, five patients showed a lipid peak at 0.9–1.3 ppm, and three patients showed a negative lactic acid peak at 1.33 ppm. Compared with the control group, the ratios of N-acetyl aspartate/choline and N-acetyl aspartate/creatine were significantly decreased, and the ratio of choline/creatine was increased, in medulloblastoma patients. Diffusion weighted imaging displayed hyperintensity and decreased apparent diffusion coefficient in medulloblastoma patients. These findings indicate that 1H magnetic resonance spectroscopy and diffusion weighted imaging are useful for qualitative diagnosis of medulloblastoma.

  20. Protein dynamics from nuclear magnetic relaxation.

    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. PMID:26932314

  1. A Metabolic Study on Colon Cancer Using 1H Nuclear Magnetic Resonance Spectroscopy

    Zahra Zamani

    2014-01-01

    Full Text Available Background. Colorectal carcinoma is the third cause of cancer deaths in the world. For diagnosis, invasive methods like colonoscopy and sigmoidoscopy are used, and noninvasive screening tests are not very accurate. We decided to study the potential of 1HNMR spectroscopy with metabolomics and chemometrics as a preliminary noninvasive test. We obtained a distinguishing pattern of metabolites and metabolic pathways between colon cancer patient and normal. Methods. Sera were obtained from confirmed colon cancer patients and the same number of healthy controls. Samples were sent for 1HNMR spectroscopy and analysis was carried out Chenomex and MATLAB software. Metabolites were identified using Human Metabolic Data Base (HDMB and the main metabolic cycles were identified using Metaboanalyst software. Results. 15 metabolites were identified such as pyridoxine, orotidine, and taurocholic acid. Main metabolic cycles involved were the bile acid biosynthesis, vitamin B6 metabolism, methane metabolism, and glutathione metabolism. Discussion. The main detected metabolic cycles were also reported earlier in different cancers. Our observations corroborated earlier studies that suggest the importance of lowering serum LCA/DCA and increasing vitamin B6 intake to help prevent colon cancer. This work can be looked upon as a preliminary step in using 1HNMR analysis as a screening test before invasive procedures.

  2. Measurement of the proton electric to magnetic form factor ratio from \\vec ^1H(\\vec e, e'p)

    Crawford, C B; Alarcon, R; Bertozzi, W; Booth, E; Botto, T; Calarco, J; Clasie, B; De Grush, A; Donnelly, T W; Dow, K; Dutta, D; Farkhondeh, M; Fatemi, R; Filoti, O; Franklin, W; Gao, H; Geis, E; Gilad, S; Haeberli, W; Hasell, D; Hersman, W; Holtrop, M; Karpius, P; Kolster, H; Köhl, M; Lee, T; Maschinot, A; Matthews, J; McIlhany, K; Meitanis, N; Milner, R G; Rapaport, J; Redwine, R P; Seely, J; Shinozaki, A; Sindile, A; Sirca, S; Six, E; Smith, T; Tonguc, B; Tschalär, C; Tsentalovich, E; Turchinetz, W E; Van den Brand, J F J; Wang, F; Wise, T; Xiao, Y; Xu, W; Zhang, C; Zhou, Z; Ziskin, V; Zwart, T; Van der Laan, J

    2006-01-01

    We report the first precision measurement of the proton electric to magnetic form factor ratio from spin-dependent elastic scattering of longitudinally polarized electrons from a polarized hydrogen internal gas target. The measurement was performed at the MIT-Bates South Hall Ring over a range of four-momentum transfer squared $Q^2$ from 0.15 to 0.65 (GeV/c)$^2$. Significantly improved results on the proton electric and magnetic form factors are obtained in combination with previous cross-section data on elastic electron-proton scattering in the same $Q^2$ region.

  3. Nuclear magnetic resonance studies of erythrocyte membranes

    Chapman, D.; Kamat, V.B.; Gier, J. de; Penkett, S.A.

    1968-01-01

    The use of nuclear magnetic resonance spectroscopy for studying molecular interactions in biological membranes has been investigated using erythrocyte membrane fragments. Sonic dispersion of these fragments produces a sharp and well-defined high-resolution nuclear magnetic resonance spectrum. The sp

  4. Contribution to nuclear magnetic resonance imager using permanent magnets

    After some recalls of nuclear magnetic resonance, ways to get a stable and homogeneous magnetic field are studied with permanent magnets. Development of correction coils on integrated circuits has been particularly stressed. Gradient coil specific systems have been studied taking in account ferromagnetic material presence. Antenna system has been improved and possibility of image obtention with the prototype realized has been shown

  5. Determination of nuclear distances and chemical-shift anisotropy from 1H MAS NMR sideband patterns of surface OH groups

    Fenzke, Dieter; Hunger, Michael; Pfeifer, Harry

    A procedure is described which allows a separate determination of the proton-aluminum distance and of the chemical-shift anisotropy for the bridging OH groups of crystalline molecular sieves from their 'H MAS NMR sideband patterns. For the bridging OH groups which point into the 6-rings of the framework (line "c"), the 1H- 27Al distance could be determined to be 0.237 ± 0.004 and 0.234 ± 0.004 nm for molecular sieves of type H-Y and SAPO-5, respectively. In contrast, for the bridging OH groups of the 12-rings (line "b"), the corresponding distances are equal and distinctly larger, 0.248 ± 0.004 nm. Within the limits of error, the values of the chemical-shift anisotropy are equal (about 19 ± 2 ppm) except for line b of SAPO-5, which exhibits a much smaller value of 14.5 ± 2 ppm.

  6. The 1H and 13C dynamic nuclear polarization (DNP) enhancement for novel silica phase immobilized nitroxide (SPIN) samples

    Gitti, Rossitza K.

    1991-01-01

    The solid/liquid intermolecular transfer (SLIT) flow dynamic nuclear polarization (DNP) experiment potentially provides new methodology for studying interfacial phenomena (e.g., weak hydrogen bonding). In addition, the high efficiency of the transfer also ensures dramatically enhanced NMR signals. These large DNP enhancements could alleviate sensitivity limitations in various flow NMR experiments. Previous studies have established that silica phase immobilized nitroxide (SPIN) ...

  7. Nuclear magnetic resonance studies of cytochromes c in solution

    Cytochromes c are small soluble proteins, which have been extensively studied by nuclear magnetic resonance spectroscopy. The specific NMR features of paramagnetic proteins are discussed for the oxidized form (paramagnetic shift and line broadening). Early NMR studies have focused on the electronic structure of the heme and its direct environment. The conformations of cytochromes c are now investigated by two-dimensional 1H NMR spectroscopy combined with restrained molecular dynamics. 15N and 13C NMR, which greatly benefit from isotopic enrichment, may help in obtaining reliable 1H assignments and thus high quality solution structure. Finally, hydrogen exchange rates provide insight in the rigidity (and stability) of cytochromes c in both redox states at the atomic level. (author). 50 refs., 1 fig., 1 tab

  8. Parahydrogen enhanced zero-field nuclear magnetic resonance

    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...

  9. Proton magnetic resonance spectroscopy (1H MRS) of human brain tumours: assessment of differences between tumour types and its applicability in brain tumour categorization

    Our objective was to evaluate the usefulness of proton magnetic resonance spectroscopy (1H MRS) in categorizing brain tumours. In vivo single-voxel 1H MRS at an echo time of 136 ms was performed in 108 patients with brain neoplasms that included 29 meningiomas (MEN), 15 low-grade astrocytomas (LGA), 12 anaplastic astrocytomas (AA), 25 glioblastomas (GBM) and 27 metastases (MET). Time-domain fitted areas of nine resonances were evaluated in all spectra. Twenty-five additional tumours were prospectively included as independent test set. Differences in at least two resonances were found in all pairwise comparisons of tumour groups except in GBM vs MET. Large lipid resonance at 1.30 ppm was found to be characteristic of GBM and MET, and alanine was characteristic of MEN. Significant differences were found between LGA and AA in choline-containing compounds and total creatine resonances. When implemented in a stepwise algorithm, these findings correctly classified 84% (21 of 25) tumours in the independent test set. Some additional utility was found in glycine/myo-inositol at 3.55 ppm for bilateral differentiation between GBM and MET (9 of 11, 82% correct classification in the test set). 1H MRS provides useful information to categorize the most common brain tumours that can be implemented in clinical practice with satisfactory results. (orig.)

  10. The Response of RIF-1 Fibrosarcomas to the Vascular-Disrupting Agent ZD6126 Assessed by In Vivo and Ex Vivo1H Magnetic Resonance Spectroscopy

    Basetti Madhu

    2006-07-01

    Full Text Available The response of radiation-induced fibrosarcoma1 (RIF-1 tumors treated with the vascular-disrupting agent (VDA ZD6126 was assessed by in vivo and ex vivo1H magnetic resonance spectroscopy (MRS methods. Tumors treated with 200 mg/kg ZD6126 showed a significant reduction in total choline (tCho in vivo 24 hours after treatment, whereas control tumors showed a significant increase in tCho. This response was investigated further within both ex vivo unprocessed tumor tissues and tumor tissue metabolite extracts. Ex vivo high-resolution magic angle spinning (HRMAS and 1H MRS of metabolite extracts revealed a significant reduction in phosphocholine and glycerophosphocholine in biopsies of ZD6126-treated tumors, confirming in vivo tCho response. ZD6126-induced reduction in choline compounds is consistent with a reduction in cell membrane turnover associated with necrosis and cell death following disruption of the tumor vasculature. In vivo tumor tissue water diffusion and lactate measurements showed no significant changes in response to ZD6126. Spin-spin relaxation times (T2 of water and metabolites also remained unchanged. Noninvasive 1H MRS measurement of tCho in vivo provides a potential biomarker of tumor response to VDAs in RIF-1 tumors.

  11. Metabolite concentrations in supraventricular white matter from teenage to early old age: A short echo time 1H magnetic resonance spectroscopy (MRS) study

    Raininko, Raili (Dept. of Radiology, Uppsala Univ., Uppsala (Sweden)), e-mail: raili.raininko@radiol.uu.se; Mattsson, Peter (Dept. of Neuroscience, Neurology, Uppsala Univ., Uppsala (Sweden))

    2010-04-15

    Background: Age- and sex-related changes of metabolites in healthy adult brains have been examined with different 1H magnetic resonance spectroscopy (MRS) methods in varying populations, and with differing results. A long repetition time and short echo time technique reduces quantification errors due to T1 and T2 relaxation effects and makes it possible to measure metabolites with short T2 relaxation times. Purpose: To examine the effect of age on the metabolite concentrations measured by 1H MRS in normal supraventricular white matter using a long repetition time (TR) and a short echo time (TE). Material and Methods: Supraventricular white matter of 57 healthy subjects (25 women, 32 men), aged 13 to 72 years, was examined with a single-voxel MRS at 1.5T using a TR of 6000 ms and a TE of 22 ms. Tissue water was used as a reference in quantification. Results: Myoinositol increased slightly and total N-acetyl aspartate (NAA) decreased slightly with increasing age. Glutamine/glutamate complex (Glx) showed U-shaped age dependence, with highest concentrations in the youngest and oldest subjects. No significant age dependence was found in total choline and total creatine. No gender differences were found. Macromolecule/ lipid (ML) fractions were reliably measurable only in 36/57 or even fewer subjects and showed very large deviations. Conclusion: The concentrations of several metabolites in cerebral supraventricular white matter are age dependent on 1H MRS, even in young and middle-aged people, and age dependency can be nonlinear. Each 1H MRS study of the brain should therefore take age into account, whereas sex does not appear to be so important. The use of macromolecule and lipid evaluations is compromised by less successful quantification and large variations in healthy people

  12. Metabolite concentrations in supraventricular white matter from teenage to early old age: A short echo time {sup 1}H magnetic resonance spectroscopy (MRS) study

    Raininko, Raili [Dept. of Radiology, Uppsala Univ., Uppsala (Sweden)], e-mail: raili.raininko@radiol.uu.se; Mattsson, Peter [Dept. of Neuroscience, Neurology, Uppsala Univ., Uppsala (Sweden)

    2010-04-15

    Background: Age- and sex-related changes of metabolites in healthy adult brains have been examined with different {sup 1}H magnetic resonance spectroscopy (MRS) methods in varying populations, and with differing results. A long repetition time and short echo time technique reduces quantification errors due to T1 and T2 relaxation effects and makes it possible to measure metabolites with short T2 relaxation times. Purpose: To examine the effect of age on the metabolite concentrations measured by 1H MRS in normal supraventricular white matter using a long repetition time (TR) and a short echo time (TE). Material and Methods: Supraventricular white matter of 57 healthy subjects (25 women, 32 men), aged 13 to 72 years, was examined with a single-voxel MRS at 1.5T using a TR of 6000 ms and a TE of 22 ms. Tissue water was used as a reference in quantification. Results: Myoinositol increased slightly and total N-acetyl aspartate (NAA) decreased slightly with increasing age. Glutamine/glutamate complex (Glx) showed U-shaped age dependence, with highest concentrations in the youngest and oldest subjects. No significant age dependence was found in total choline and total creatine. No gender differences were found. Macromolecule/ lipid (ML) fractions were reliably measurable only in 36/57 or even fewer subjects and showed very large deviations. Conclusion: The concentrations of several metabolites in cerebral supraventricular white matter are age dependent on 1H MRS, even in young and middle-aged people, and age dependency can be nonlinear. Each 1H MRS study of the brain should therefore take age into account, whereas sex does not appear to be so important. The use of macromolecule and lipid evaluations is compromised by less successful quantification and large variations in healthy people.

  13. Metabolite concentrations in supraventricular white matter from teenage to early old age: A short echo time 1H magnetic resonance spectroscopy (MRS) study

    Background: Age- and sex-related changes of metabolites in healthy adult brains have been examined with different 1H magnetic resonance spectroscopy (MRS) methods in varying populations, and with differing results. A long repetition time and short echo time technique reduces quantification errors due to T1 and T2 relaxation effects and makes it possible to measure metabolites with short T2 relaxation times. Purpose: To examine the effect of age on the metabolite concentrations measured by 1H MRS in normal supraventricular white matter using a long repetition time (TR) and a short echo time (TE). Material and Methods: Supraventricular white matter of 57 healthy subjects (25 women, 32 men), aged 13 to 72 years, was examined with a single-voxel MRS at 1.5T using a TR of 6000 ms and a TE of 22 ms. Tissue water was used as a reference in quantification. Results: Myoinositol increased slightly and total N-acetyl aspartate (NAA) decreased slightly with increasing age. Glutamine/glutamate complex (Glx) showed U-shaped age dependence, with highest concentrations in the youngest and oldest subjects. No significant age dependence was found in total choline and total creatine. No gender differences were found. Macromolecule/ lipid (ML) fractions were reliably measurable only in 36/57 or even fewer subjects and showed very large deviations. Conclusion: The concentrations of several metabolites in cerebral supraventricular white matter are age dependent on 1H MRS, even in young and middle-aged people, and age dependency can be nonlinear. Each 1H MRS study of the brain should therefore take age into account, whereas sex does not appear to be so important. The use of macromolecule and lipid evaluations is compromised by less successful quantification and large variations in healthy people

  14. A survey on quantitative analysis of organic compounds by nuclear magnetic resonance (NMR) spectroscopy

    Nuclear Magnetic Resonance (NMR) spectroscopy is known as a powerful analytical technique, which is used to determine the structure of small and macro organic compounds. In recent years, 1H NMR is being recognized more and more as a quantitative analytical method, which is based on the principle where the area under a 1H NMR signal peak in solution state is proportional to the number of nuclei contributing to the peak. In this report, the basic concepts, developmental history and current state of the quantitative 1H NMR (qNMR) method are described. Furthermore, future prospect of the qNMR method is presented. (author)

  15. (1)H-NMR and charge transport in metallic polypyrrole at ultra-low temperatures and high magnetic fields.

    Jugeshwar Singh, K; Clark, W G; Ramesh, K P; Menon, Reghu

    2008-11-19

    The temperature dependence of conductivity, proton spin relaxation time (T(1)) and magnetoconductance (MC) in metallic polypyrrole (PPy) doped with PF(6)(-) have been carried out at mK temperatures and high magnetic fields. At T50 K-relaxation is due to the dipolar interaction modulated by the reorientation of the symmetric PF(6) groups following the Bloembergen, Purcell and Pound (BPP) model. The data analysis shows that the Korringa ratio is enhanced by an order of magnitude. The positive and negative MC at TmK is due to the contributions from weak localization and Coulomb-correlated hopping transport, respectively. The role of EEI is observed to be consistent in conductivity, T(1) and MC data, especially at T<1 K. PMID:21693848

  16. DIFFERENTIATION BETWEEN BENIGN PROSTATIC HYPERPLASIA AND PROSTATE CANCER IN THE TRANSITIONAL ZONE EVALUATED BY 1H MAGNETIC RESONANCE SPECTROSCOPIC IMAGING

    Sa-ying Li; Min Chen; Rui Wang; Cheng Zhou

    2007-01-01

    To quantitatively evaluate the metabolic changes of benign prostatic hyperplasia (BPH) and prostate cancer in the transitional zone using magnetic resonance spectroscopic imaging ( MRSI), and to analyze the characteristics and differences of the spectra in this zonal area.Methods Eighteen patients with prostate cancer in the transitional zone underwent magnetic resonance imaging( MRI)/MRSI examinations. The ( Choline + Creatine)/Citrate (CC/Ci) ratio and the Choline/Creatine (Cho/Cr) ratio were evaluated in each voxel with cancer or BPH confirmed by pathological results. Discriminant analysis was used to determine the power of the two ratios in differentiation between cancer and BPH.Results The CC/Ci ratio and Cho/Cr ratio for cancer voxels were significantly higher than those in the voxels with BPH in the transitional zone ( CC/Ci: 2.36 ± 1.31 vs. 0.85 ± 0.29, P < 0.01; Cho/Cr: 4.14 ± 1.79 vs. 1.26 ±0.45, P < 0.01 ). As for the discriminant function with the CC/Ci ratio and the Cho/Cr ratio, the specificity, sensitivity, and accuracy were 98.6%, 85.7%, 92.9% respectively for the differentiation between cancer and BPH.Conclusions The prostate cancer is characterized by higher CC/Ci ratio and Cho/Cr ratio compared to BPH in the transitional zone. Both CC/Ci ratio and Cho/Cr ratio have high specificity, sensitivity, and accuracy in their discriminative power between cancer and BPH in this zonal area.

  17. Whole-brain patterns of (1)H-magnetic resonance spectroscopy imaging in Alzheimer's disease and dementia with Lewy bodies.

    Su, L; Blamire, A M; Watson, R; He, J; Hayes, L; O'Brien, J T

    2016-01-01

    Magnetic resonance spectroscopy has demonstrated metabolite changes in neurodegenerative disorders such as Alzheimer's disease (AD) and dementia with Lewy bodies (DLB); however, their pattern and relationship to clinical symptoms is unclear. To determine whether the spatial patterns of brain-metabolite changes in AD and DLB are regional or diffused, and to examine whether the key metabolite levels are associated with cognitive and non-cognitive symptoms, we acquired whole-brain spatially resolved 3T magnetic resonance spectroscopic imaging (MRSI) data from subjects with AD (N=36), DLB (N=35) and similarly aged controls (N=35). Voxel-wise measurement of N-acetylaspartate to creatine (NAA/Cr), choline to Cr (Cho/Cr), myo-inositol to Cr (mI/Cr) as well as glutamate and glutamine to Cr (Glx/Cr) ratios were determined using MRSI. Compared with controls, AD and DLB groups showed a significant decrease in most brain metabolites, with NAA/Cr, Cho/Cr and mI/Cr levels being reduced in posterior cingulate, thalamus, frontotemporal areas and basal ganglia. The Glx/Cr level was more widely decreased in DLB (posterior cingulate, hippocampus, temporal regions and caudate) than in AD (only in posterior cingulate). DLB was also associated with increased levels of Cho/Cr, NAA/Cr and mI/Cr in occipital regions. Changes in metabolism in the brain were correlated with cognitive and non-cognitive symptoms in the DLB but not in the AD group. The different patterns between AD and DLB may have implications for improving diagnosis, better understanding disease-specific neurobiology and targeting therapeutics. In addition, the study raised important questions about the role of occipital neuroinflammation and glial activation as well as the glutamatergic treatment in DLB. PMID:27576166

  18. Nuclear reactions in ultra-magnetized supernovae

    The statistical model is employed to investigate nuclear reactions in ultrastrong magnetic fields relevant for supernovae and neutron stars. For radiative capture processes the predominant mechanisms are argued to correspond to modifications of nuclear level densities, and γ-transition energies due to interactions of the field with magnetic moments of nuclei. The density of states reflects the nuclear structure and results in oscillations of reaction cross sections as a function of field strength, while magnetic interaction energy enhances radiative neutron capture process. Implications in the synthesis of r-process nuclei in supernova site are discussed. (author)

  19. Inductively coupled NMR probe for versatile dynamic nuclear polarization operation at 7 T: Observation of 61 ± 2% 1H polarization at 4 K

    Siaw, Ting Ann; Walker, Shamon A.; Armstrong, Brandon D.; Han, Song-I.

    2012-08-01

    We have performed dynamic nuclear polarization (DNP) experiments at liquid helium temperatures using a low-power (probe for the detection of 1H NMR signal at 300 MHz, as such coils are well suited for higher frequency NMR detection. The Alderman-Grant coil is inductively coupled to the rest of the radiofrequency (rf) circuit, whose design allows probe components to be placed away from the sample area, and also enables easy switching of coils with different diameters and resonance frequencies. We have tested our DNP instrument on a frozen nitroxide model system consisting of 4-Amino TEMPO dissolved in a glycerol:water mixture. The largest nuclear spin polarization observed was 61 ± 2% with a sample containing 20 mM 4-Amino TEMPO dissolved in deuterated glycerol (d-glycerol):D2O:H2O (50:40:10), amounting to record polarization measured to date at an easily amenable temperature of 4 K.

  20. Design and test of a double-nuclear RF coil for 1H MRI and 13C MRSI at 7 T

    Rutledge, Omar; Kwak, Tiffany; Cao, Peng; Zhang, Xiaoliang

    2016-06-01

    RF coil operation at the ultrahigh field of 7 T is fraught with technical challenges that limit the advancement of novel human in vivo applications at 7 T. In this work, a hybrid technique combining a microstrip transmission line and a lumped-element L-C loop coil to form a double-nuclear RF coil for proton magnetic resonance imaging and carbon magnetic resonance spectroscopy at 7 T was proposed and investigated. Network analysis revealed a high Q-factor and excellent decoupling between the coils. Proton images and localized carbon spectra were acquired with high sensitivity. The successful testing of this novel double-nuclear coil demonstrates the feasibility of this hybrid design for double-nuclear MR imaging and spectroscopy studies at the ultrahigh field of 7 T.

  1. Design and test of a double-nuclear RF coil for (1)H MRI and (13)C MRSI at 7T.

    Rutledge, Omar; Kwak, Tiffany; Cao, Peng; Zhang, Xiaoliang

    2016-06-01

    RF coil operation at the ultrahigh field of 7T is fraught with technical challenges that limit the advancement of novel human in vivo applications at 7T. In this work, a hybrid technique combining a microstrip transmission line and a lumped-element L-C loop coil to form a double-nuclear RF coil for proton magnetic resonance imaging and carbon magnetic resonance spectroscopy at 7T was proposed and investigated. Network analysis revealed a high Q-factor and excellent decoupling between the coils. Proton images and localized carbon spectra were acquired with high sensitivity. The successful testing of this novel double-nuclear coil demonstrates the feasibility of this hybrid design for double-nuclear MR imaging and spectroscopy studies at the ultrahigh field of 7T. PMID:27078089

  2. Chronic Cocaine Use and Its Association with Myocardial Steatosis Evaluated by 1H Magnetic Resonance Spectroscopy in African Americans

    Lai, Shenghan; Gerstenblith, Gary; Li, Ji; Zhu, Hong; Bluemke, David A.; Liu, Chia-Ying; Zimmerman, Stefan L.; Chen, Shaoguang; Lai, Hong; Treisman, Glenn

    2014-01-01

    Objectives Cardiac steatosis is a manifestation of ectopic fat deposition and is associated with obesity. The impact of chronic cocaine use on obesity measures and on the relationship between obesity measures and cardiac steatosis is not well-characterized. The objectives of this study were to compare obesity measures in chronic cocaine users and non-users, and to explore which factors, in addition to obesity measures, are associated with myocardial triglyceride in African Americans (AAs), using noninvasive magnetic resonance spectroscopy (MRS). Methods Between June 2004 and January 2014, 180 healthy AA adults without HIV infection, hypertension and diabetes were enrolled in an observational proton MRS and imaging study investigating factors associated with cardiac steatosis. Results Among these 180 participants, 80 were chronic cocaine users, and 100 were non-users. The median age (with IQR) was 42 (34-47) years. Obesity measures trended higher in cocaine users than non-users. The median myocardial triglyceride was 0.6% (IQR:0.4-1.1%). Among the factors investigated, years of cocaine use, leptin and visceral fat were independently associated with myocardial triglyceride. BMI and visceral fat, which were significantly associated with myocardial triglyceride in non-cocaine users, were not associated with myocardial triglycerides content in cocaine users. Conclusions This study shows (1) cocaine users may have more fat than nonusers and (2) myocardial triglyceride is independently associated with duration of cocaine use, leptin, and visceral fat in all subjects, while leptin and HDL-cholesterol, but not visceral fat or BMI, in cocaine users, suggesting that chronic cocaine use may modify the relationships between obesity measures and myocardial triglyceride. PMID:25325298

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

    The authors have developed an animal model to elucidate the acute effects of perfusion abnormalities on muscle metabolism induced by different density-defined classes of erythrocytes isolated from sickle cell anemia patients. Technetium-99m (99mTc)-labeled, saline-washed normal (AA), homozygous sickle (SS), or high-density SS (SS4) erythrocytes were injected into the femoral artery of the rat and quantitative 99mTc imaging, 31P magnetic resonance spectroscopy by surface coil at 2 teslas, and 1H magnetic resonance imaging at 0.15 tesla were performed. Between 5 and 25 μl of SS4 cells was trapped in the microcirculation of the thigh. In contrast, fewer SS discocytes (SS2) or AA cells were trapped. After injection of SS4 cells an initial increase in inorganic phosphate was observed in the region of the thigh served by the femoral artery, intracellular pH decreased, and subsequently the proton relaxation time T1 reached a broad maximum at 18-28 hr. When T1 obtained at this time was plotted against the volume of cells trapped, an increase of T1 over the control value of 411 ± 48 msec was found that was proportional to the number of cells trapped. They conclude that the densest SS cells are most effective at producing vasoocclusion. The extent of the change detected by 1H magnetic resonance imaging is dependent on the amount of cells trapped in the microcirculation and the magnitude of the initial increase of inorganic phosphate

  4. Nuclear Magnetic Resonance Imaging: Current Capabilities

    Davis, Peter L.; Crooks, Lawrence E.; Margulis, Alexander R.; Kaufman, Leon

    1982-01-01

    Nuclear magnetic resonance imaging can produce tomographic images of the body without ionizing radiation. Images of the head, chest, abdomen, pelvis and extremities have been obtained and normal structures and pathology have been identified. Soft tissue contrast with this method is superior to that with x-ray computerized tomography and its spatial resolution is approaching that of x-ray computerized tomography. In addition, nuclear magnetic resonance imaging enables us to image along the sag...

  5. Nuclear magnetic (ratio-frequency) tomography

    Physical foundations of nuclear magnetic tomography and factors limiting its spatial, contrast and time precision are considered. On the basis of analysis of literature data, it is established that using peculiarities of nuclear magnetic resonance (NMR) it is possible to detect malignant tumors and edemas, to investigate metabolic processes, to determine blood flow rate and to solve a number of other problems. The classification of methods of NMR - tomography is given

  6. Nuclear magnetic (radio-frequency) tomography

    Pavlov, A.S.; Gurvich, A.M.; Karyakina, N.F.; Revokatov, O.P.; Chikirdin, Eh.G. (Nauchno-Issledovatel' skij Inst. Rentgenologii i Radiologii, Moscow (USSR))

    Physical foundations of nuclear magnetic tomography and factors limiting its spatial, contrast and time precision are considered. On the basis of analysis of literature data, it is established that using peculiarities of nuclear magnetic resonance (NMR) it is possible to detect malignant tumors and edemas, to investigate metabolic processes, to determine blood flow rate and to solve a number of other problems. The classification of methods of NMR - tomography is given.

  7. Analysis of brain metabolism by proton magnetic resonance spectroscopy (1H-MRS) in attention-deficit/hyperactivity disorder suggests a generalized differential ontogenic pattern from controls.

    Arcos-Burgos, Mauricio; Londoño, Ana C; Pineda, David A; Lopera, Francisco; Palacio, Juan David; Arbelaez, Andres; Acosta, Maria T; Vélez, Jorge I; Castellanos, Francisco Xavier; Muenke, Maximilian

    2012-12-01

    Attention-deficit/hyperactivity disorder (ADHD) is the most common behavioral disorder of childhood. Preliminary studies with proton magnetic resonance spectroscopy ((1)H-MRS) of the brain have reported differences in brain metabolite concentration-to-Cr ratios between individuals with ADHD and unaffected controls in several frontal brain regions including anterior cingulate cortex. Using multivoxel (1)H-MRS, we compared 14 individuals affected with ADHD to 20 individuals without ADHD from the same genetic isolate. After controlling by sex, age, and multiple testing, we found significant differences at the right posterior cingulate of the Glx/Cr ratio density distribution function between ADHD cases and controls (P metabolite concentration-to-Cr ratio, age, and ADHD status: Ins/Cr and Glx/Cr ratios at the left posterior cingulate, and NAA/Cr at the splenius, right posterior cingulate, and at the left posterior cingulate. We also found a differential metabolite ratio interaction between ADHD cases and controls for Ins/Cr and NAA/Cr at the right striatum. These results show that: (1) NAA/Cr, Glx/Cr, and Ins/Cr ratios, as reported in other studies, exhibit significant differences between ADHD cases and controls; (2) differences of these metabolite ratios between ADHD cases and controls evolve in specific and recognizable patterns throughout age, a finding that replicates previous results obtained by structural MRI, where is demonstrated that brain ontogeny follows a different program in ADHD cases and controls; (3) Ins/Cr and NAA/Cr ratios, at the right striatum, interact in a differential way between ADHD cases and controls. As a whole, these results replicate previous 1H-MRS findings and add new intriguing differential metabolic and ontogeny patterns between ADHD cases and controls that warrant further pursue. PMID:23012086

  8. Generation of nuclear magnetic resonance images

    Two generation techniques of nuclear magnetic resonance images, the retro-projection and the direct transformation method are studied these techniques are based on the acquisition of NMR signals which phases and frequency components are codified in space by application of magnetic field gradients. The construction of magnet coils is discussed, in particular a suitable magnet geometry with polar pieces and air gap. The obtention of image contrast by T1 and T2 relaxation times reconstructed from generated signals using sequences such as spin-echo, inversion-recovery and stimulated echo, is discussed. The mathematical formalism of matrix solution for Bloch equations is also presented. (M.C.K.)

  9. Nuclear magnetic resonance (NMR): principles and applications

    The basis for the phenomenon of nuclear magnetic resonance (NMR) is the ability of certain nuclei possessing both intrinsic angular momentum or ''spin'' I and magnetic moment to absorb electromagnetic energy in the radio frequency range. In principle, there are approximately 200 nuclei which may be investigated using the NMR technique. The NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum provides a variety of qualitative and quantitative analytical applications. The most obvious applications consist of the measurements of nuclear properties, such as spin number and nuclear magnetic moment. In liquids, the fine structure of resonance spectra provides a tool for chemical identification and molecular structure analysis. Other applications include the measurements of self-diffusion coefficients, magnetic fields and field homogeneity, inter-nuclear distances, and, in some cases, the water content of biological materials. (author)

  10. Theory of nuclear magnetic moments - LT-35

    The purpose of these notes is to give an account of some attempts at interpreting the observed values of nuclear magnetic moments. There is no attempt at a complete summary of the field as that would take much more space than is used here. In many cases the arguments are only outlined and references are given for those interested in further details. A discussion of the theory of nuclear magnetic moments necessitates many excursions into the details of the nuclear models because the magnetic moments have a direct bearing on the validity of these models. However the main emphasis here is on those features which tend to explain the magnetic moments and other evidence is not discussed unless it has a direct bearing on the problem. In the first part of the discussion the Shell Model of the nucleus is used, as this model seems to correlate a large body of data relating to the heavier nuclei. Included here are the modifications proposed to explain the fact that the experimental magnetic moments do not fit quantitatively with the exact predictions of the Shell Model. The next sections deal with some of the more drastic modifications introduced to explain the large nuclear quadrupole moments and the effect of these modifications on the magnetic moments. Finally we turn to more detailed investigations of the light nuclei, in particular the - Conjugate nuclei. (author)

  11. Copper(II) tetrafluoroborate complexes with the N(3),N(4)-bridging coordination of 1-(tert-butyl)-1H-tetrazole: synthesis, crystal structure and magnetic properties.

    Degtyarik, Mikhail M; Lyakhov, Alexander S; Ivashkevich, Ludmila S; Matulis, Vitaly E; Matulis, Vadim E; Gruschinski, Sina; Voitekhovich, Sergei V; Kersting, Berthold; Ivashkevich, Oleg A

    2015-11-14

    1-(tert-Butyl)-1H-tetrazole (L) reacts with copper(ii) tetrafluoroborate hexahydrate to give the complexes [Cu2L8(H2O)2](BF4)4 (1) or [Cu3L6(H2O)6](BF4)6 (2) depending on the reaction conditions. These complexes, as well as compound L, were characterized using single crystal X-ray analysis. Complex 1 was found to comprise a dinuclear complex cation [Cu2L8(H2O)2](4+) (the Ci symmetry point group), with six tetrazole ligands L showing monodentate N(4)-coordination, and two ligands L providing two tetrazole ring N(3),N(4) bridges between the copper(ii) cations; water molecules complete the distorted octahedral coordination of the metal ions. Complex 2 includes a linear trinuclear complex cation [Cu3L6(H2O)6](6+) (the S6 symmetry point group), in which neighbouring copper(ii) cations are linked by three ligands L via tetrazole ring N(3),N(4) bridges; central and terminal metal ions show octahedral CuN6 and CuN3O3 coordination cores, respectively. The temperature-dependent magnetic susceptibility measurements of complex 2 revealed that the copper(ii) ions were weakly ferromagnetically coupled showing a coupling constant J of 2.2 cm(-1) {H = -2J(S1S2 + S2S3)}. The quantum-chemical investigation of the electronic structure and basicity of ligand L was carried out. PMID:26442910

  12. Analysis of Brain Metabolism by Proton-Magnetic-Resonance-Spectroscopy (1H-MRS) in Attention-Deficit/Hyperactivity Disorder Suggests a Generalized Differential Ontogenic Pattern from Controls

    Arcos-Burgos, Mauricio; Londoño, Ana C.; Pineda, David A.; Lopera, Francisco; Palacio, Juan David; Arbelaez, Andres; Acosta, Maria T.; Vélez, Jorge I.; Castellanos, Francisco Xavier; Muenke, Maximilian

    2012-01-01

    Attention-deficit/hyperactivity disorder (ADHD) is the most common behavioral disorder of childhood. Preliminary studies with proton magnetic resonance spectroscopy (1HMRS) of the brain have reported differences in brain metabolite concentration-to-Cr ratios between individuals with ADHD and unaffected controls in several frontal brain regions including anterior cingulate cortex. Using multivoxel 1H-MRS, we compared 14 individuals affected with ADHD to 20 individuals without ADHD from the same genetic isolate. After controlling by sex, age and multiple testing, we found significant differences at the right posterior cingulate of the Glx/Cr ratio density distribution function between ADHD cases and controls (P<0.05). Furthermore, we found several interactions of metabolite concentration-to-Cr ratio, age, and ADHD status: Ins/Cr and Glx/Cr ratios at the left posterior cingulate, and NAA/Cr at the splenius, right posterior cingulate, and at the left posterior cingulate. We also found a differential metabolite ratio interaction between ADHD cases and controls for Ins/Cr and NAA/Cr at the right striatum. These results show that: 1) NAA/Cr, Glx/Cr and Ins/Cr ratios, as reported in other studies, exhibit significant differences between ADHD cases and controls; 2) differences of these metabolite ratios between ADHD cases and controls evolve in specific and recognizable patterns throughout age, a finding that replicates previous results obtained by structural MRI, where is demonstrated that brain ontogeny follows a different program in ADHD cases and controls; 3) Ins/Cr and NAA/Cr ratios, at the right striatum, interact in a differential way between ADHD cases and controls. As a whole, these results replicate previous 1H-MRS findings and add new intriguing differential metabolic and ontogeny patterns between ADHD cases and controls that warrant further pursue. PMID:23012086

  13. Pulsed nuclear-electronic magnetic resonance

    Morley, Gavin W; Mohammady, M Hamed; Aeppli, Gabriel; Kay, Christopher W M; Jeschke, Gunnar; Monteiro, Tania S

    2011-01-01

    Pulsed magnetic resonance is a wide-reaching technology allowing the quantum state of electronic and nuclear spins to be controlled on the timescale of nanoseconds and microseconds respectively. The time required to flip either dilute electronic or nuclear spins is orders of magnitude shorter than their decoherence times, leading to several schemes for quantum information processing with spin qubits. We investigate instead the novel regime where the eigenstates approximate 50:50 superpositions of the electronic and nuclear spin states forming "nuclear-electronic" qubits. Here we demonstrate quantum control of these states, using bismuth-doped silicon, in just 32 ns: orders of magnitude shorter than previous experiments where pure nuclear states were used. The coherence times of our states are over four orders of magnitude longer, being 1 ms or more at 8 K, and are limited by the naturally-occurring 29Si nuclear spin impurities. There is quantitative agreement between our experiments and no-free-parameter anal...

  14. Progress in nuclear magnetic resonance spectroscopy

    Emsley, J W; Sutcliffe, L H

    2013-01-01

    Progress in Nuclear Magnetic Resonance Spectroscopy, Part 1 is a two-chapter text that reviews significant developments in nuclear magnetic resonance (NMR) applications.The first chapter discusses NMR studies of molecules physisorbed on homogeneous surfaces. This chapter also describes the phase changes in the adsorbed layer detected by following the variation in the NMR parameters. The second chapter examines the process to obtain a plotted, data reduced Fourier transform NMR spectrum. This chapter highlights the pitfalls that can cause a decrease in information content in a NMR spectrum. The

  15. Nuclear magnetic resonance of thermally oriented nuclei

    The more recent developments in the spectroscopy of Nuclear Magnetic Resonance on Oriented Nuclei (NMRON) are reviewed; both theoretical and experimental advances are summarised with applications to On-Line and Off-Line determination of magnetic dipole and electric quadrupole hyperfine parameters. Some emphasis is provided on solid state considerations with indications of where likely enhancements in technique will lead in conventional hyperfine studies. (orig.)

  16. Nuclear magnetic resonance in Kondo lattice systems

    Curro, Nicholas J.

    2016-06-01

    Nuclear magnetic resonance has emerged as a vital tool to explore the fundamental physics of Kondo lattice systems. Because nuclear spins experience two different hyperfine couplings to the itinerant conduction electrons and to the local f moments, the Knight shift can probe multiple types of spin correlations that are not accessible via other techniques. The Knight shift provides direct information about the onset of heavy electron coherence and the emergence of the heavy electron fluid.

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

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

    2011-12-01

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

  18. magnetic order studied by nuclear methods

    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...

  19. Characterization of Maytenus ilicifolia samples by {sup 1}H NMR relaxation in the solid state; Caracterizacao dos constituintes polimericos da Maytenus ilicifolia por relaxacao nuclear de {sup 1}H por RMN no estado solido

    Preto, Monica S. de M.; Tavares, Maria I.B., E-mail: mibt@ima.ufrj.br [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano. Lab de Ressonancia Magnetica Nuclear; Sebastiao, Pedro J.O. [Departamento de Fisica, Instituto Superior Tecnico, Lisboa (Portugal)

    2011-07-01

    The Maytenus ilicifolia (espinheira-santa) is a popular medicinal plant with different uses. It is native of South America and can be found in Brazil. In the Brazilian market it is possible found products labeled as M. ilicifolia. So far, the studies published in the literature involve the modification of the natural materials and do not concern the comparison between commercial the raw natural materials. Different non-destructive NMR techniques can be used to study natural materials. In this work it is presented a characterization study by Fast Field Cycling of the {sup 1}H spin-lattice relaxation time (T{sub 1}) NMR, in the frequency range 100 khz-10 MHz. The results obtained in two commercial M. ilicifolia samples and one control sample collected in natura are compared. It was intended to study the possibility to elaborate a characterization method using FFCNMR suitable for the verification of authenticity and/or evaluation of tampering on products. The differences detected by FFCNMR relaxometry were confirmed by thermogravimetric analysis and infrared spectroscopy. (author)

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

    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. Serum metabonomics of acute leukemia using nuclear magnetic resonance spectroscopy

    Musharraf, Syed Ghulam; Siddiqui, Amna Jabbar; Shamsi, Tahir; Choudhary, M. Iqbal; Rahman, Atta-ur

    2016-01-01

    Acute leukemia is a critical neoplasm of white blood cells. In order to differentiate between the metabolic alterations associated with two subtypes of acute leukemia, acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML), we investigated the serum of ALL and AML patients and compared with two controls (healthy and aplastic anemia) using 1H NMR (nuclear magnetic resonance) spectroscopy. Thirty-seven putative metabolites were identified using Carr-Purcell-Meiboom-Gill (CPMG) sequence. The use of PLS-DA and OPLS-DA models gave results with 84.38% and 90.63% classification rate, respectively. The metabolites responsible for classification are mainly lipids, lactate and glucose. Compared with controls, ALL and AML patients showed serum metabonomic differences involving aberrant metabolism pathways including glycolysis, TCA cycle, lipoprotein changes, choline and fatty acid metabolisms. PMID:27480133

  2. Nuclear magnetic resonance spectroscopy of single subnanoliter ova

    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.

  3. Phosphonate Based High Nuclearity Magnetic Cages.

    Sheikh, Javeed Ahmad; Jena, Himanshu Sekhar; Clearfield, Abraham; Konar, Sanjit

    2016-06-21

    Transition metal based high nuclearity molecular magnetic cages are a very important class of compounds owing to their potential applications in fabricating new generation molecular magnets such as single molecular magnets, magnetic refrigerants, etc. Most of the reported polynuclear cages contain carboxylates or alkoxides as ligands. However, the binding ability of phosphonates with transition metal ions is stronger than the carboxylates or alkoxides. The presence of three oxygen donor sites enables phosphonates to bridge up to nine metal centers simultaneously. But very few phosphonate based transition metal cages were reported in the literature until recently, mainly because of synthetic difficulties, propensity to result in layered compounds, and also their poor crystalline properties. Accordingly, various synthetic strategies have been followed by several groups in order to overcome such synthetic difficulties. These strategies mainly include use of small preformed metal precursors, proper choice of coligands along with the phosphonate ligands, and use of sterically hindered bulky phosphonate ligands. Currently, the phosphonate system offers a library of high nuclearity transition metal and mixed metal (3d-4f) cages with aesthetically pleasing structures and interesting magnetic properties. This Account is in the form of a research landscape on our efforts to synthesize and characterize new types of phosphonate based high nuclearity paramagnetic transition metal cages. We quite often experienced synthetic difficulties with such versatile systems in assembling high nuclearity metal cages. Few methods have been emphasized for the self-assembly of phosphonate systems with suitable transition metal ions in achieving high nuclearity. We highlighted our journey from 2005 until today for phosphonate based high nuclearity transition metal cages with V(IV/V), Mn(II/III), Fe(III), Co(II), Ni(II), and Cu(II) metal ions and their magnetic properties. We observed that

  4. Identification, synthesis and characterization of an unknown process related impurity in eslicarbazepine acetate active pharmaceutical ingredient by LC/ESI-IT/MS, 1H, 13C and 1H-1H COSY NMR

    Saji Thomas; Saroj Kumar Paul; Subhash Chandra Joshi; Vineet Kumar; Ashutosh Agarwal; Dharam Vir

    2014-01-01

    A new impurity was detected during high performance liquid chromatographic (HPLC) analysis of eslicarbazepine acetate active pharmaceutical ingredient. The structure of unknown impurity was postulated based on liquid chromatography mass spectrometry using electrospray ionization and ion trap analyzer (LC/ESI-IT/MS) analysis. Proposed structure of impurity was unambiguously confirmed by synthesis followed by characterization using 1H, 13C nuclear magnetic resonance spectrometry (NMR), 1H-1H correlation spectro-scopy (COSY) and infrared spectroscopy (IR). Based on the spectroscopic and spectrometric data, unknown impurity was characterized as 5-carbamoyl-10,11-dihydro-5H-dibenzo[b,f]azepin-10-yl propionate.

  5. H nuclear magnetic resonance spectroscopy-based metabonomic study in patients with cirrhosis and hepatic encephalopathy

    Dabos, Konstantinos John; Parkinson, John Andrew; Sadler, Ian Howard; Plevris, John Nicholas; Hayes, Peter Clive

    2015-01-01

    AIM: To identify plasma metabolites used as biomarkers in order to distinguish cirrhotics from controls and encephalopathics. METHODS: A clinical study involving stable cirrhotic patients with and without overt hepatic encephalopathy was designed. A control group of healthy volunteers was used. Plasma from those patients was analysed using 1H - nuclear magnetic resonance spectroscopy. We used the Carr Purcell Meiboom Gill sequence to process the sample spectra at ambient probe temperature. We...

  6. High resolution nuclear magnetic resonance spectroscopy (NMR) studies on meat components: potentialities and prospects

    Antonio Sacco; Gino Vonghia; Francesco Giannico; Daniela Sacco; Vincenzo di Martino; Anna Caputi Jambrenghi; Maria Antonietta Brescia

    2010-01-01

    In recent years, increasing application of nuclear magnetic resonance (NMR) spectroscopy in the study of the agricultur-  al food products has been remarked, thanks to the advantages of this technique over other conventional analytical tech-  niques. This preliminary work presents, for the first time, the application of an innovative NMR technique, the  proton  high resolution magic angle spinning (1H HR-MAS), for studying meat features. It stresses that this method makes ...

  7. Studies of phospholipid hydration by high-resolution magic-angle spinning nuclear magnetic resonance.

    Zhou, Z.; Sayer, B G; Hughes, D. W.; Stark, R E; Epand, R M

    1999-01-01

    A sample preparation method using spherical glass ampoules has been used to achieve 1.5-Hz resolution in 1H magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of aqueous multilamellar dispersions of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), serving to differentiate between slowly exchanging interlamellar and bulk water and to reveal new molecular-level information about hydration phenomena in these model biolo...

  8. Thermal transition of ribonuclease a observed using proton nuclear magnetic resonance

    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

  9. Electron and nuclear magnetic resonances in compounds and metallic hydrides

    Proton pulsed Nuclear Magnetic Resonance measurements were performed on the metallic hydrides ZrCr2Hx (x = 2, 3, 4) and ZrV2Hy (y = 2, 3, 4, 5) as a function of temperature between 180 and 400K. The ultimate aim was the investigation of the relaxation mechanisms in these systems by means of the measurement of both the proton (1H) spin-lattice (T1) and spin-spin (T2) relaxation times and to use these data to obtain information about the diffusive motion of the hydrogen atoms. The diffusional activation energies, the jump frequencies and the Korringa constant, Ck, related with the conduction electron contribution to the 1H relaxation were determined for the above hydrides as a function of hydrogen concentration. Our results were analysed in terms of the relaxation models described by Bloembergen, Purcell and Pound (BPP model) and by Torrey. The Korringa type relaxation due to the conduction electrons in metallic systems was also used to interpret the experimental results. We also present the Electron Paramagnetic Ressonance (EPR) study of Gd3+, Nd3+ and Er3+ ions as impurities in several AB3 intermetallic compounds where A = LA, Ce, Y, Sc, Th, Zr and B = Rh, Ir, Pt. The results were analysed in terms of the multiband model previously suggested to explain the behaviour of the resonance parameter in AB2 Laves Phase compounds. (author)

  10. Nuclear magnetic resonance as a petrophysical measurement

    Nuclear magnetic resonance (NMR) of hydrogen nuclei in fluids which saturate porous rocks is important in oil exploration and production, since NMR logs can provide good estimates of permeability and fluid flow. This paper reviews developments which connect the NMR properties of rocks with petrophysical properties, and particularly those relating to fluid flow. The recent advances in the use of NMR in boreholes which have spurred these developments are also discussed. The relevance of other NMR measurements on geological samples, including magnetic resonance imaging, is briefly referred to. (author)

  11. Nuclear magnetic ordering ''avant toute chose''

    We give an overview of the research initiated at Saclay to study cooperative phenomena between nuclear spins in the presence of a high magnetic field. These systems exhibit a wealth of different orderings including antiferromagnetism, ferromagnetism with domains and transverse structures rotating about the static magnetic field. These states have been characterized by NMR of the ordered nuclei, NMR of dilute probe nuclei, double resonance methods and neutron diffraction. Some related phenomena involving the coupling of spins with the lattice are reported. Finally we outline future experiments which will benefit of the insight brought by the study of dipolar ordering. (authors). 30 refs., 11 figs

  12. Thin layer and nuclear magnetic resonance magnetometers

    In the first part of this text, magnetometers with sensitive elements in the form of thin cylindrical ferromagnetic layers are described. These layers are anisotropic, uniaxial, C orientated and single domains. In the second part of the text, the principles of the nuclear magnetic resonance magnetometer realized at the LETI are presented. This instrument is accurate, of high efficiency, and isotropic. Very small variations in magnetic field intensity (10-7 oersteds) can be detected with a 1Hz pass band at zero frequency

  13. Two-Dimensional Nuclear Magnetic Resonance Structure Determination Module for Introductory Biochemistry: Synthesis and Structural Characterization of Lyso-Glycerophospholipids

    Garrett, Teresa A.; Rose, Rebecca L.; Bell, Sidney M.

    2013-01-01

    In this laboratory module, introductory biochemistry students are exposed to two-dimensional [superscript 1]H-nuclear magnetic resonance of glycerophospholipids (GPLs). Working in groups of three, students enzymatically synthesized and purified a variety of 2-acyl lyso GPLs. The structure of the 2-acyl lyso GPL was verified using [superscript…

  14. Spin-Glass Behavior, Magnetic, and IR Spectroscopy Analysis of Multimetallic Compound Ni0.25Mn1.25[Fe(CN6]·6.1H2O

    Qing Lin

    2015-01-01

    Full Text Available Multimetallic Prussian blue compound Ni0.25Mn1.25[Fe(CN6]·6.1H2O has been prepared by coprecipitation. The temperature-dependent magnetic susceptibilities show the magnet transition for the compound at 8.5 K. According to DC variable-temperature magnetic susceptibility paramagnetic Curie temperature θ is −9.32 K. The observed value of coercive field (Hc and the remanent magnetization (Mr for the compound are 0.32 KOe and 0.36 μB. According to study of zero-field-cooled (ZFC and field-cooled (FC magnetization curves and AC magnetization curves, there exists a spin-glass behaviour in the compound, which exhibits freezing temperature Tg=7.76 K, below magnetic transition TC=8.5 K; that glass behavior is termed “reentrant” spin glass.

  15. Quantitative study of diet reversal in rat galactosemic cataract via nuclear magnetic resonance relaxation times

    The diet-reversal phenomenon in rat galactosemic cataract seems similar to the cataract reversal caused by aldose-reductase (AR) inhibitors. In previous studies, we reported this phenomenon morphologically and biochemically, and described a new method of evaluating cataractous changes via proton nuclear magnetic resonance (1H-NMR) relaxation times (T1, T2). In the present study, we fed 25% galactose chow to SD-strain male rats (body weight 50 g) for 1 or 2 weeks, changed the galactose chow to a normal diet (diet reversal), and then measured relaxation times (T1, T2) over time. The results showed that 1H-NMR relaxation times were useful in evaluating the healing of galactosemic cataract after diet reversal. Thus, 1H-NMR may be useful in evaluating the effectiveness of AR inhibitors. (author)

  16. Magnetic property and thermal analysis of a Mn(II) complex with [Mn(CO2)]n chains based on 4,4‧-bis(1H-imidazol-1-yl-methyl)biphenyl

    Zhang, Ming-Dao; Zheng, Bao-Hui; Wang, Zhe; Jiao, Yan; Chen, Min-Dong

    2014-11-01

    Magnetic coordination polymers have attracted considerable interest due to their novel structures and potential applications. In this paper, one new 2D magnetic manganese coordination polymer {[Mn(bimb)(OBA)]}n (1) was synthesized under solvothermal conditions based on 4,4‧-bis(1H-imidazol-1-yl-methyl)biphenyl (bimb) and 4,4‧-oxybis(benzoate) (H2OBA). Complex 1 contains [Mn(CO2)]n 1D chains and magnetic susceptibility measurements indicate that compound 1 exhibits an antiferromagnetic coupling interaction. In addition, complex 1 exhibits solid-state photoluminescence and high thermal stability.

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

    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 place

  18. Nuclear magnetic moments measured by nuclear magnetic resonance on oriented nuclei

    The configurations of nuclei near the shell closures N=40 and Z=40 were studied. The nuclear magnetic moments have been measured by nuclear magnetic resonance on oriented nuclei (NMR/ON). We have determined the ground state spin of 73Se and magnetic moments of isotopes 73Se(9/2+), 77Br3/2-) and 74Brm(4). The 9/2+ spin and parity assignment to the parent state of 73Se is perfectly compatible with the systematics of N + 39 and N = 41 isotones. The bromine moments around the shell closure N = 40, show a change in protonic configuration. In the second part of this work a precise hyperfine field value of zinc in iron has been determined. The relaxation constant of Zn in iron is established. The new hyperfine field value of zinc in iron allows a more precise reevaluation of the magnetic moments of 69Znm and 71Znm measured with NMR/ON

  19. Analysis of metabolites in human brain tumors and cerebral infarctions using {sup 31}P- and {sup 1}H-magnetic resonance spectroscopy

    Hirakawa, Wataru [Kagoshima Univ. (Japan). Faculty of Medicine

    1996-08-01

    {sup 31}P- and {sup 1}H-MRS with a 2.0 tesla MRI/S system was used to monitor the cerebral energy levels, phospholipid metabolism, intracellular pH, and lactate and amino acid levels in patients with brain tumors and cerebral infarctions. Studies of human brain tumors have suggested that the {sup 31}P-MRS of malignant brain tumors show low concentrations of phosphocreatine (PCr) and {beta}-ATP, high levels of phosphomonoester (PME) and inorganic Pi, and an alkaline pH. The Pi, PME, and intracellular pH of malignant lymphoma were higher than those of other brain tumors. {sup 1}H-MRS showed an increase of lactate in malignant brain tumors and epidermoids. After ACNU administration, the tumor {sup 31}P-MRS showed transient reduction and elevation of Pi on five patients with malignant gliomas. Intracellular pH also showed a transient reduction during radiotherapy. {sup 1}H-MRS showed a reduction of lactate at the beginning of therapy and showed a marked re-elevation of lactate with tumor regrowth. After radiotherapy, the normal brain {sup 31}P-MRS showed transient elevation and reduction of Pi. Intracellular pH also showed a transient elevation during radiotherapy. To investigate the mechanism of hyperbaric oxygen therapy (HBO) in cerebral ischemia, changes of brain lactate level were estimated by {sup 1}H-MRS. Although the Lactate/Creatine ratio decreased consistently over time in all patients, it decreased more rapidly in the patients receiving HBO therapy than in those without such therapy. {sup 1}H-MRS demonstrated that HBO therapy may improve metabolism in the ischemic brain and reduces the lactate levels. {sup 31}P- and {sup 1}H-MRS are practical tools for the clinical analysis of cerebral disorders as well as for deciding on therapeutic procedures and evaluating the response. (K.H.)

  20. Nuclear magnetic resonance common laboratory, quadrennial report

    This quadrennial report of the nuclear magnetic resonance common laboratory gives an overview of the main activities. Among the different described activities, only one is interesting for the INIS database: it concerns the Solid NMR of cements used for radioactive wastes storage. In this case, the NMR is used to characterize the structure of the material and the composition, structure and kinetics of formation of the alteration layer which is formed at the surface of concrete during water leaching conditions. The NMR methodology is given. (O.M.)

  1. Nuclear Magnetic Resonance in Liquids and Solids

    The paper outlines the basic principles of nuclear magnetic resonance, trying wherever possible to compare and contrast the method with that of slow neutron scattering as a technique for studying the properties of condensed phases and especially of molecular and atomic motions. It is emphasized that this is not a review of nmr for an expert audience but has a pedagogical aim. It is hoped to give persons with a main interest in neutron scattering some appreciation of the scope and limitations of the nmr method. This is illustrated by recent results on one substance which covers many but by no means all of the important points. (author)

  2. Connection of nuclear magnetic and infiltration parameters of porous rocks

    The infiltration parameters of porous rocks are determined among others by the specific pore surface. In the case of the sandostones the nuclear magnetic behaviour of the water influx is also influenced by the specific surface of the pores. On this basis the nuclear magnetic and the infiltration parameters of the rocks can be brought into connection with each other. The paper deals with the rock-physics of the nuclear magnetic logging. (author)

  3. Nuclear magnetic resonance in hexaferrite/maghemite composite nanoparticles

    Kříšťan, P.; Hondlík, O.; Štěpánková, H.; Chlan, V.; Kouřil, K.; Řezníček, R.; Pollert, Emil; Veverka, Pavel

    Warszawa: Polish Academy of Sciences, 2015, s. 514-516. ISSN 0587-4246. [The European Conference PHYSICS OF MAGNETISM 2014/PM'14/. Poznań (PL), 23.06.2014-27.06.2014] Institutional support: RVO:68378271 Keywords : nuclear magnetic resonance and relaxation * ferrimagnetics * fine-particle systems * nanocrystalline materials * magnetic oxides * inorganic compounds Subject RIV: BM - Solid Matter Physics ; Magnetism

  4. Nuclear magnetic resonance (NMR) studies of homeopathic solutions.

    Aabel, S; Fossheim, S; Rise, F

    2001-01-01

    The efficacy of homeopathy is controversial. Nuclear magnetic resonance (NMR) has been used to study homeopathic solutions, showing provocative results. We examined the reproducibility of one of the allegedly positive studies. 1H NMR spectra were recorded for Sulphur D4, diluted and succussed up to D30 (called potentization) at two different frequencies (300 and 500 MHz). The Sulphur solution had been potentiated according to homeopathic principles with deionized water and alcohol. Water proton T1 relaxation measurements were performed also at 20 MHz for the different potentiated Sulphur solutions. Furthermore, the homeopathic remedy Betula alba 30c (birch pollen extract) and appropriate control solution (deionized water, unsuccussed solutions and placebo globules) were measured analogously, both with frequencies giving spectra and T1 relaxometry. The Sulphur remedies showed identical one dimensional proton spectra (1H NMR) at 300 and 500 MHz, regardless of dilution/succussion stage, from D4 to D30. Furthermore, Betula 30c as a potentiated solution and its controls (ethanol dilutions and Betula diluted but not succussed) showed identical spectra. Nor were there any statistically significant differences in longitudinal (T1) relaxation times between deionized water and Sulphur D10 to D30 preparations. The shorter T1 of the Sulphur D4 preparation could be ascribed to the higher microviscosity within the sample matrix caused by the high concentration of dissolved material. Also, the T1 values of the Betula alba 30c preparation (in globular form) and control placebo globules were identical. In conclusion, published results from NMR research on homeopathy indicating differences between homeopathic solutions and control samples could not be reproduced. PMID:11212083

  5. 1H Nuclear Magnetic Resonance Study of Olive Oils Commercially Available as Italian Products in the United States of America

    Laura Del Coco; Francesco Paolo Schena; Francesco Paolo Fanizzi

    2012-01-01

    Multivariate analysis of 1H NMR data has been used for the characterization of 12 blended olive oils commercially available in the U.S. as Italian products. Chemometric methods such as unsupervised Principal Component Analysis (PCA) allowed good discrimination and gave some affinity indications for the U.S. market olive oils compared to other single cultivars of extra virgin olive oil such as Coratina and Ogliarola from Apulia, one of Italy’s leading olive oil producers...

  6. Selective inversion of 1H resonances in solid-state nuclear magnetic resonance: Use of double-DANTE pulse sequence

    Mithu, Venus Singh; Tan, Kong Ooi; Madhu, P. K.

    2013-12-01

    We here present a method based on DANTE pulses and homonuclear dipolar decoupling scheme to invert selectively any desired resonance in a proton spin system under magic-angle spinning. Experimental results are reported on a sample of L-histidine·HCl·H2O at magic-angle spinning frequencies of 15 and 60 kHz. The results are also substantiated numerically.

  7. 1H Nuclear Magnetic Resonance Study of Olive Oils Commercially Available as Italian Products in the United States of America

    Laura Del Coco

    2012-05-01

    Full Text Available Multivariate analysis of 1H NMR data has been used for the characterization of 12 blended olive oils commercially available in the U.S. as Italian products. Chemometric methods such as unsupervised Principal Component Analysis (PCA allowed good discrimination and gave some affinity indications for the U.S. market olive oils compared to other single cultivars of extra virgin olive oil such as Coratina and Ogliarola from Apulia, one of Italy’s leading olive oil producers, Picual (Spain, Kalamata (Greece and Sfax (Tunisia. The olive oils commercially available as Italian products in the U.S. market clustered into 3 groups. Among them only the first (7 samples and the second group (2 samples showed PCA ranges similar to European references. Two oils of the third group (3 samples were more similar to Tunisian references. In conclusion, our study revealed that most EVOO (extra virgin olive oils tested were closer to Greek (in particular and Spanish olive oils than Apulia EVOO. The PCA loadings disclose the components responsible for the discrimination as unsaturated (oleic, linoleic, linolenic and saturated fatty acids. All are of great importance because of their nutritional value and differential effects on the oxidative stability of oils. It is evident that this approach has the potential to reveal the origin of EVOO, although the results support the need for a larger database, including EVOO from other Italian regions.

  8. The (1) H NMR spectrum of pyrazole in a nematic phase.

    Provasi, Patricio; Jimeno, María Luisa; Alkorta, Ibon; Reviriego, Felipe; Elguero, José; Jokisaari, Jukka

    2016-08-01

    The experimental (1) H nuclear magnetic resonance (NMR) spectrum of 1H-pyrazole was recorded in thermotropic nematic liquid crystal N-(p-ethoxybenzylidene)-p-butylaniline (EBBA) within the temperature range of 299-308 K. Two of three observable dipolar DHH -couplings appeared to be equal at each temperature because of fast prototropic tautomerism. Analysis of the Saupe orientational order parameters using fixed geometry determined by computations and experimental dipolar couplings results in a situation in which the molecular orientation relative to the magnetic field (and the liquid crystal director) can be described exceptionally by a single parameter. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26947581

  9. Nuclear magnetic resonance spectrometer and method

    A nuclear magnetic resonance techniis described that allows simultaneous temperature determination and spectral acquisition. The technique employs a modification of the lock circuit of a varian xl-100 spectrometer which permits accurate measurement of the difference in resonance frequency between a primary lock nucleus and another , secondary, nucleus. The field stabilization function of the main lock circuit is not compromised. A feedback signal having a frequency equal to the frequency difference is substituted for the normal power supply in the spectrometer's existing radio frequency transmitter to modulate that transmitter. Thus, the transmitter's radio frequency signal is enhanced in a frequency corresponding to the resonance peak of the secondary nucleus. Determination of the frequency difference allows the determination of temperature without interference with the observed spectrum. The feedback character of the circuit and the presence of noise make the circuit self-activating

  10. Two-dimensional nuclear magnetic resonance petrophysics.

    Sun, Boqin; Dunn, Keh-Jim

    2005-02-01

    Two-dimensional nuclear magnetic resonance (2D NMR) opens a wide area for exploration in petrophysics and has significant impact to petroleum logging technology. When there are multiple fluids with different diffusion coefficients saturated in a porous medium, this information can be extracted and clearly delineated from CPMG measurements of such a system either using regular pulsing sequences or modified two window sequences. The 2D NMR plot with independent variables of T2 relaxation time and diffusion coefficient allows clear separation of oil and water signals in the rocks. This 2D concept can be extended to general studies of fluid-saturated porous media involving other combinations of two or more independent variables, such as chemical shift and T1/T2 relaxation time (reflecting pore size), proton population and diffusion contrast, etc. PMID:15833623

  11. Phosphorus 31 nuclear magnetic resonance examination of female reproductive tissues

    Nuclear magnetic resonance spectroscopy is a powerful method of investigating the relationship between metabolism and function in living tissues. We present evidence that the phosphorus 31 spectra of myometrium and placenta are functions of physiologic state and gestational age. Specific spectroscopic abnormalities are observed in association with disorders of pregnancy and gynecologic diseases. Our results suggest that noninvasive nuclear magnetic resonance spectroscopy examinations may sometimes be a useful addition to magnetic resonance imaging examinations, and that nuclear magnetic resonance spectroscopy of biopsy specimens could become a cost-effective method of evaluating certain biochemical abnormalities

  12. Structural Characterization of Amadori Rearrangement Product of Glucosylated Nα-Acetyl-Lysine by Nuclear Magnetic Resonance Spectroscopy

    Chuanjiang Li

    2014-01-01

    Full Text Available Maillard reaction is a nonenzymatic reaction between reducing sugars and free amino acid moieties, which is known as one of the most important modifications in food science. It is essential to characterize the structure of Amadori rearrangement products (ARPs formed in the early stage of Maillard reaction. In the present study, the Nα-acetyl-lysine-glucose model had been successfully set up to produce ARP, Nα-acetyl-lysine-glucose. After HPLC purification, ARP had been identified by ESI-MS with intense [M+H]+ ion at 351 m/z and the purity of ARP was confirmed to be over 90% by the relative intensity of [M+H]+ ion. Further structural characterization of the ARP was accomplished by using nuclear magnetic resonance (NMR spectroscopy, including 1D 1H NMR and 13C NMR, the distortionless enhancement by polarization transfer (DEPT-135 and 2D 1H-1H and 13C-1H correlation spectroscopy (COSY and 2D nuclear overhauser enhancement spectroscopy (NOESY. The complexity of 1D 1H NMR and 13C NMR was observed due to the presence of isomers in glucose moiety of ARP. However, DEPT-135 and 2D NMR techniques provided more structural information to assign the 1H and 13C resonances of ARP. 2D NOESY had successfully confirmed the glycosylated site between 10-N in Nα-acetyl-lysine and 7′-C in glucose.

  13. Tumor Metabolism and Perfusion in Head and Neck Squamous Cell Carcinoma: Pretreatment Multimodality Imaging With 1H Magnetic Resonance Spectroscopy, Dynamic Contrast-Enhanced MRI, and [18F]FDG-PET

    Purpose: To correlate proton magnetic resonance spectroscopy (1H-MRS), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and 18F-labeled fluorodeoxyglucose positron emission tomography ([18F]FDG PET) of nodal metastases in patients with head and neck squamous cell carcinoma (HNSCC) for assessment of tumor biology. Additionally, pretreatment multimodality imaging was evaluated for its efficacy in predicting short-term response to treatment. Methods and Materials: Metastatic neck nodes were imaged with 1H-MRS, DCE-MRI, and [18F]FDG PET in 16 patients with newly diagnosed HNSCC, before treatment. Short-term patient radiological response was evaluated at 3 to 4 months. Correlations among 1H-MRS (choline concentration relative to water [Cho/W]), DCE-MRI (volume transfer constant [Ktrans]; volume fraction of the extravascular extracellular space [ve]; and redistribution rate constant [kep]), and [18F]FDG PET (standard uptake value [SUV] and total lesion glycolysis [TLG]) were calculated using nonparametric Spearman rank correlation. To predict short-term responses, logistic regression analysis was performed. Results: A significant positive correlation was found between Cho/W and TLG (ρ = 0.599; p = 0.031). Cho/W correlated negatively with heterogeneity measures of standard deviation std(ve) (ρ = −0.691; p = 0.004) and std(kep) (ρ = −0.704; p = 0.003). Maximum SUV (SUVmax) values correlated strongly with MRI tumor volume (ρ = 0.643; p = 0.007). Logistic regression indicated that std(Ktrans) and SUVmean were significant predictors of short-term response (p 1H-MRS, DCE-MRI, and [18F]FDG PET is feasible in HNSCC patients with nodal metastases. Additionally, combined DCE-MRI and [18F]FDG PET parameters were predictive of short-term response to treatment.

  14. Moissanite anvil cell design for giga-pascal nuclear magnetic resonance

    A new design of a non-magnetic high-pressure anvil cell for nuclear magnetic resonance (NMR) experiments at Giga-Pascal pressures is presented, which uses a micro-coil inside the pressurized region for high-sensitivity NMR. The comparably small cell has a length of 22 mm and a diameter of 18 mm, so it can be used with most NMR magnets. The performance of the cell is demonstrated with external-force vs. internal-pressure experiments, and the cell is shown to perform well at pressures up to 23.5 GPa using 800 μm 6H-SiC large cone Boehler-type anvils. 1H, 23Na, 27Al, 69Ga, and 71Ga NMR test measurements are presented, which show a resolution of better than 4.5 ppm, and an almost maximum possible signal-to-noise ratio

  15. Moissanite anvil cell design for giga-pascal nuclear magnetic resonance

    Meier, Thomas; Herzig, Tobias; Haase, Jürgen

    2014-04-01

    A new design of a non-magnetic high-pressure anvil cell for nuclear magnetic resonance (NMR) experiments at Giga-Pascal pressures is presented, which uses a micro-coil inside the pressurized region for high-sensitivity NMR. The comparably small cell has a length of 22 mm and a diameter of 18 mm, so it can be used with most NMR magnets. The performance of the cell is demonstrated with external-force vs. internal-pressure experiments, and the cell is shown to perform well at pressures up to 23.5 GPa using 800 μm 6H-SiC large cone Boehler-type anvils. 1H, 23Na, 27Al, 69Ga, and 71Ga NMR test measurements are presented, which show a resolution of better than 4.5 ppm, and an almost maximum possible signal-to-noise ratio.

  16. Enhanced nuclear magnetism: some novel features and prospective experiments

    It is shown that methods used for studying nuclear magnetism and nuclear magnetic ordering can be extended to 'enhanced nuclear magnetism'. These methods include the use of r.f. fields for adiabatic demagnetization in the rotating frame (a.d.r.f) and beams of neutrons whose spins interact with the nuclear spins. The 'enhancement' of the nuclear moment arises from the electronic magnetization M1 induced through the hyperfine interaction. It is shown that the spatial distribution of M1 is the same as that of The Van Vleck magnetization induced by an external field, provided that J is a good quantum number. The spatial distributions are not in general the same in Russell-Saunders coupling, eg. in the 3d group. The Bloch equations are extended to include anisotropic nuclear moments. The 'truncated' spin Hamiltonian is derived for spin-spin interaction between enhanced moments. A general cancellation theorem for second-order processes in spin-lattice relaxation is derived. The interactions of neutrons with the true nuclear moment, the Van Vleck moment, the 'pseudonuclear' moment and the 'pseudomagnetic' nuclear moment are discussed. Ordered states of enhanced nuclear moment systems are considered, together with the conditions under which they might be produced by a.d.r.f. following dynamic nuclear polarization. (U.K.)

  17. Evaluation of sample preparation methods for nuclear magnetic resonance metabolic profiling studies with Eisenia fetida.

    Brown, Sarah A E; Simpson, André J; Simpson, Myrna J

    2008-04-01

    The earthworm Eisenia fetida is frequently used in ecotoxicological studies; however, it has not yet been investigated using proton nuclear magnetic resonance ((1)H NMR) metabolic profiling methods. The present study investigates the impact of depuration time, sample homogenization, and different extraction solvents on the quality and reproducibility of the (1)H NMR spectra of E. fetida with the goal of determining whether this species is suitable for future metabonomic studies. A depuration time of 96 h, followed by intact lyophilization before homogenization and extraction into a deuterium oxide (D(2)O)-based phosphate buffer, was found to produce extracts with excellent (1)H NMR reproducibility. The D(2)O buffer extracted the largest quantity of the widest variety of earthworm metabolites, which is consistent with the results from other studies using different earthworm species. Nuclear magnetic resonance assignments of the major metabolites in the D(2)O-based buffer also were performed and found to be similar to those for other earthworm species, such as Eisenia veneta, but also to have characteristic attributes in E. fetida. The major metabolites identified include amino acids (alanine, arginine, glutamic acid, glutamine, glycine, leucine, lysine, phenylalanine, serine, tyrosine, and valine), two sugars (glucose and maltose), the sugar alcohol mannitol, and the polyalcohol inositol. Two other earthworm species (Lumbricus rubellus and Lumbricus terrestris) also were examined using protocols developed for E. fetida, and of the three species, the (1)H NMR spectra of E. fetida had the least variation, indicating this species is well-suited for future metabolomic-based ecotoxicity studies. PMID:18333692

  18. Nuclear magnetic resonance of randomly diluted magnetic materials

    The temperature dependence of the nuclear relaxation rates and line shapes of the FO resonance in the diluted antiferromagnet Fex Zn1-x F2 and Mnx Zn1-x F2 are studied over a large temperature range TN 1) of the FO nuclei, which are not transfer hyperfine coupled to the Fe (or Mn) spins, have been measured and calculated as a function of the concentration x. Good agreement with experiment is found for the theoretical results, which have been obtained in the range 0.1 ≤ x ≤ 0.8. The temperature dependence of 1/T1 for TN1 data near TN was used to study Random Field Effects on the critical behavior of Mn.65 Zn.35 F2, for fields applied parallel and perpendicular to the easy (C) axis. It was found that the transition temperature TN depressed substantially with field only for Ho || C. The experimental results are in general accord with the theory for Random Field Effects in disordered, anisotropic antiferromagnets. The critical divergence of the inhomogeneously broadened FO NMR was studied in Fe.6 Zn.4 F2 above TN. The experimental results agree with Heller's calculation of the NMR line broadening by Random Field Effects. With Ho || C the line shape changes from Gaussian towards Lozentzian for t -2 and below TN its line width increase qualitatively following the increase in the sublattice magnetization. (author)

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

    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...

  20. Search for magnetic monopoles with nuclear track detectors

    Giorgini, M

    2000-01-01

    This paper describes an experimental search for GUT magnetic monopoles in the MACRO experiment using the nuclear track subdetector CR39. After discussing the working principle, the charge resolution and the calibration of the detector, the experimental procedure for searching for magnetic monopoles is described. Since no candidates were found, the upper flux limits obtained by the MACRO CR39 used as a "stand alone detector" for magnetic monopoles of different magnetic charges are presented.

  1. Insula-specific 1H magnetic resonance spectroscopy reactions in heavy smokers under acute nicotine withdrawal and after oral nicotine substitution

    Gutzeit, Andreas; Froehlich, Johannes M; Hergan, Klaus; Graf, Nicole; Binkert, Christoph A; Meier, Dieter; Brügger, Mike; Reischauer, Carolin; Sutter, Reto; Herdener, Marcus; Schubert, Tillmann; Kos, Sebastian; Grosshans, Martin; Straka, Matus; Mutschler, Jochen

    2013-01-01

    The aim of this study was to clarify whether addiction-specific neurometabolic reaction patterns occur in the insular cortex during acute nicotine withdrawal in tobacco smokers in comparison to nonsmokers. Fourteen male smokers and 10 male nonsmokers were included. Neurometabolites of the right and the left insular cortices were quantified by magnetic resonance spectroscopy (MRS) on a 3-Tesla scanner. Three separate MRS measurements were performed in each subject: among the smokers, the first...

  2. The emergence of proton nuclear magnetic resonance metabolomics in the cardiovascular arena as viewed from a clinical perspective

    Rankin, Naomi J.; Preiss, David; Welsh, Paul; Burgess, Karl E. V.; Nelson, Scott M; Lawlor, Debbie A.; Sattar, Naveed

    2014-01-01

    The ability to phenotype metabolic profiles in serum has increased substantially in recent years with the advent of metabolomics. Metabolomics is the study of the metabolome, defined as those molecules with an atomic mass less than 1.5 kDa. There are two main metabolomics methods: mass spectrometry (MS) and proton nuclear magnetic resonance (1H NMR) spectroscopy, each with its respective benefits and limitations. MS has greater sensitivity and so can detect many more metabolites. However, its...

  3. Identification, synthesis and characterization of an unknown process related impurity in eslicarbazepine acetate active pharmaceutical ingredient by LC/ESI–IT/MS, 1H, 13C and 1H–1H COSY NMR

    Saji Thomas; Saroj Kumar Paul; Subhash Chandra Joshi; Vineet Kumar; Ashutosh Agarwal; Dharam Vir

    2014-01-01

    A new impurity was detected during high performance liquid chromatographic (HPLC) analysis of eslicarbazepine acetate active pharmaceutical ingredient. The structure of unknown impurity was postulated based on liquid chromatography mass spectrometry using electrospray ionization and ion trap analyzer (LC/ESI–IT/MS) analysis. Proposed structure of impurity was unambiguously confirmed by synthesis followed by characterization using 1H, 13C nuclear magnetic resonance spectrometry (NMR), 1H–1H co...

  4. Least Squares Magnetic-Field Optimization for Portable Nuclear Magnetic Resonance Magnet Design

    Single-sided and mobile nuclear magnetic resonance (NMR) sensors have the advantages of portability, low cost, and low power consumption compared to conventional high-field NMR and magnetic resonance imaging (MRI) systems. We present fast, flexible, and easy-to-implement target field algorithms for mobile NMR and MRI magnet design. The optimization finds a global optimum in a cost function that minimizes the error in the target magnetic field in the sense of least squares. When the technique is tested on a ring array of permanent-magnet elements, the solution matches the classical dipole Halbach solution. For a single-sided handheld NMR sensor, the algorithm yields a 640 G field homogeneous to 16,100 ppm across a 1.9 cc volume located 1.5 cm above the top of the magnets and homogeneous to 32,200 ppm over a 7.6 cc volume. This regime is adequate for MRI applications. We demonstrate that the homogeneous region can be continuously moved away from the sensor by rotating magnet rod elements, opening the way for NMR sensors with adjustable 'sensitive volumes'

  5. Development of low field nuclear magnetic resonance system using HTS rf SQUID

    We constructed a low-field (LF) nuclear magnetic resonance (NMR) system using a HTS rf SQUID and room-temperature (RT) coils. In the system, a measurement field coil, a polarizing coil and ac pulse coil were employed. In addition, gradient coils were introduced to compensate the remnant field gradient around the sample and to improve the homogeneity of Bm. With gradient coils, the spin-spin relaxation time T2* of a free induction decay (FID) signals of 1H was 2.2 s, 1.7 times longer than that without gradient coil in an experiment employing Bm of 44.8 μT and Bp of 36.8 mT. The conditions of Bac (amplitude, duration) to rotate the magnetized vector of 1H by a certain angle were experimentally studied for application of a 900 - 1800 spin echo sequence. It was also found that the minimum delay time for applying the 1800 pulse to obtain the spin echo signal of 1H was approximately 2.5 s.

  6. Correlative and quantitative 1H NMR-based metabolomics reveals specific metabolic pathway disturbances in diabetic rats

    Zhang, Shucha; Gowda, G. A. Nagana; Asiago, Vincent; Shanaiah, Narasimhamurthy; Barbas, Coral; Raftery, Daniel

    2008-01-01

    Type 1 diabetes was induced in Sprague–Dawley rats using streptozotocin. Rat urine samples (8 diabetic and 10 control) were analyzed by 1H nuclear magnetic resonance (NMR) spectroscopy. The derived metabolites using univariate and multivariate statistical analysis were subjected to correlative analysis. Plasma metabolites were measured by a series of bioassays. A total of 17 urinary metabolites were identified in the 1H NMR spectra and the loadings plots after principal components analysis. D...

  7. Nuclear magnetic resonance studies of metabolic regulation

    Nuclear magnetic resonance (NMR) techniques for the detection of the metabolic transformations of biological compounds labeled with stable isotopes, particularly carbon-13 have been explored. We have studied adipose tissue in the intact rat, the exteriorized epididymal fat pad, and the isolated adipocyte. Triacylglycerol metabolism in adipose tissue is regulated by lipogenic factors (insulin, corticosterone, thyroxine, and growth hormone) and lipolytic factors (glucagon and catecholamines). The synthesis of triglyceride from 5.5 mM glucose was stimulated by about 4-fold by 10 nM insulin. Triglyceride synthesis from glucose in the presence of insulin occurred at a rate of 330 nmol/hr/106 cells. Since the NMR signals from free and esterified fatty acids and glycerol are distinct, we could directly measure the rate of hormone-stimulated lipolysis. Epinephrine (10 μM) gave a lipolytic rate of 0.30 μmol/hr/106 cells as monitored by free-glycerol appearance in the medium. 13C NMR provides a superior method for the measurement of triglyceride metabolism since it directly measures the changes in the substrates and products in situ

  8. Nuclear Composition of Magnetized GRB Jets

    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...

  9. Nuclear magnetic resonance (NMR)-based metabolomics.

    Keun, Hector C; Athersuch, Toby J

    2011-01-01

    Biofluids are by far the most commonly studied sample type in metabolic profiling studies, encompassing blood, urine, cerebrospinal fluid, cell culture media and many others. A number of these fluids can be obtained at a high sampling frequency with minimal invasion, permitting detailed characterisation of dynamic metabolic events. One of the attractive properties of solution-state metabolomics is the ability to generate profiles from these fluids following simple preparation, allowing the analyst to gain a naturalistic, largely unbiased view of their composition that is highly representative of the in vivo situation. Solution-state samples can also be generated from the extraction of tissue or cellular samples that can be tailored to target metabolites with particular properties. Nuclear magnetic resonance (NMR) provides an excellent technique for profiling these fluids and is especially adept at characterising complex solutions. Profiling biofluid samples by NMR requires appropriate preparation and experimental conditions to overcome the demands of varied sample matrices, including those with high protein, lipid or saline content, as well as the presence of water in aqueous samples. PMID:21207299

  10. Selectivity in multiple quantum nuclear magnetic resonance

    The observation of multiple-quantum nuclear magnetic resonance transitions in isotropic or anisotropic liquids is shown to give readily interpretable information on molecular configurations, rates of motional processes, and intramolecular interactions. However, the observed intensity of high multiple-quantum transitions falls off dramatically as the number of coupled spins increases. The theory of multiple-quantum NMR is developed through the density matrix formalism, and exact intensities are derived for several cases (isotropic first-order systems and anisotropic systems with high symmetry) to shown that this intensity decrease is expected if standard multiple-quantum pulse sequences are used. New pulse sequences are developed which excite coherences and produce population inversions only between selected states, even though other transitions are simultaneously resonant. One type of selective excitation presented only allows molecules to absorb and emit photons in groups of n. Coherent averaging theory is extended to describe these selective sequences, and to design sequences which are selective to arbitrarily high order in the Magnus expansion. This theory and computer calculations both show that extremely good selectivity and large signal enhancements are possible

  11. Nuclear magnetic tomography in the differential diagnosis of liver disease

    Roedl, W.

    1985-05-01

    In evaluating nuclear magnetic tomography for the diagnosis of liver disease, one must differentiate between circumscribed and diffuse lesions. Nuclear magnetic tomography provides additional information for lesions which are echogenic on ultrasound and can differentiate between metastases, haemangiomas and hamartomas. In diffuse parenchymal disease measurement of relaxation time can differentiate between fatty liver, cirrhosis (alcoholic, primary biliary), haemochromatosis (cirrhotic transformation) and hepatoma. NMR spectroscopy is a method for the future.

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

    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.

  13. GEOCHEMICAL CONTROLS ON NUCLEAR MAGNETIC RESONANCE MEASUREMENTS

    Proton nuclear magnetic resonance (NMR) is used in the Earth Sciences as a means of obtaining information about the molecular-scale environment of fluids in porous geological materials. Laboratory experiments were conducted to advance our fundamental understanding of the link between the NMR response and the geochemical properties of geological materials. In the first part of this research project, we studied the impact of both the surface-area-to-volume ratio (S/V) of the pore space and the surface relaxivity on the NMR response of fluids in sand-clay mixtures. This study highlighted the way in which these two parameters control our ability to use NMR measurements to detect and quantify fluid saturation in multiphase saturated systems. The second part of the project was designed to explore the way in which the mineralogic form of iron, as opposed to simply the concentration of iron, affects the surface relaxation rate and, more generally, the NMR response of porous materials. We found that the magnitude of the surface relaxation rate was different for the various iron-oxide minerals because of changes in both the surface-area-to-volume ratio of the pore space, and the surface relaxivity. Of particular significance from this study was the finding of an anomalously large surface relaxivity of magnetite compared to that of the other iron minerals. Differences in the NMR response of iron minerals were seen in column experiments during the reaction of ferrihydrite-coated quartz sand with aqueous Fe(II) solutions to form goethite, lepidocrocite and magnetite; indicating the potential use of NMR as a means of monitoring geochemical reactions. The final part of the research project investigated the impact of heterogeneity, at the pore-scale, on the NMR response. This work highlighted the way in which the geochemistry, by controlling the surface relaxivity, has a significant impact on the link between NMR data and the microgeometry of the pore space.

  14. Magnetic La{sub 1−x}Sr{sub x}MnO{sub 3} nanoparticles as contrast agents for MRI: the parameters affecting {sup 1}H transverse relaxation

    Veverka, P.; Kaman, O., E-mail: kamano@seznam.cz; Kačenka, M. [AS CR, v. v. i., Institute of Physics (Czech Republic); Herynek, V. [Institute for Clinical and Experimental Medicine (Czech Republic); Veverka, M.; Šantavá, E. [AS CR, v. v. i., Institute of Physics (Czech Republic); Lukeš, I. [Charles University, Department of Inorganic Chemistry, Faculty of Science (Czech Republic); Jirák, Z. [AS CR, v. v. i., Institute of Physics (Czech Republic)

    2015-01-15

    Magnetic nanoparticles of the La{sub 1−x}Sr{sub x}MnO{sub 3} perovskite phase (x = 0.20–0.45) were synthesized by a sol–gel method followed by thermal and mechanical treatments. The particles were coated with a uniform silica shell, and differential centrifugation yielded a product with high colloidal stability in water. X-ray powder diffraction (XRD) data showed that the mechanical processing did not affect the lattice parameters of the magnetic cores but only reduced their mean size d{sub XRD}. The magnetic properties of the bare particles were mainly controlled by the chemical composition and were also affected by the size of the particles. Subsequent silica coating led to an effective decrease in magnetization. Relaxometry measurements were focused primarily on colloids using magnetic cores of the same size (d{sub XRD} ≈ 20 nm) and different compositions, and coated with a shell measuring approximately 20 nm in thickness. The exceedingly high transverse relaxivities [r{sub 2}(20 °C) = 290–430 s{sup −1} mmol{sup −1} L at B{sub 0} = 0.5 T] of the samples exhibited pronounced temperature dependence and correlated very well with the magnetic data. Additional samples differing in the size of the cores and silica shell thickness were prepared as well to analyze the effect of the particles on {sup 1}H transverse relaxation. The results suggest that the dominant regime of transverse relaxation is the static dephasing regime.

  15. 170 Nanometer Nuclear Magnetic Resonance Imaging using Magnetic Resonance Force Microscopy

    Thurber, K R; Smith, D D; Thurber, Kent R.; Harrell, Lee E.; Smith, Doran D.

    2003-01-01

    We demonstrate one-dimensional nuclear magnetic resonance imaging of the semiconductor GaAs with 170 nanometer slice separation and resolve two regions of reduced nuclear spin polarization density separated by only 500 nanometers. This is achieved by force detection of the magnetic resonance, Magnetic Resonance Force Microscopy (MRFM), in combination with optical pumping to increase the nuclear spin polarization. Optical pumping of the GaAs creates spin polarization up to 12 times larger than the thermal nuclear spin polarization at 5 K and 4 T. The experiment is sensitive to sample volumes containing $\\sim 4 \\times 10^{11}$ $^{71}$Ga$/\\sqrt{Hz}$. These results demonstrate the ability of force-detected magnetic resonance to apply magnetic resonance imaging to semiconductor devices and other nanostructures.

  16. 1H-Magnetic resonance spectroscopy study of stimulant medication effect on brain metabolites in French Canadian children with attention deficit hyperactivity disorder

    BenAmor L

    2014-01-01

    Full Text Available Leila BenAmor1,21Department of Psychiatry Sainte-Justine Hospital, Montreal, Quebec, Canada; 2Department of Psychiatry, University of Montreal, Montreal, Quebec, CanadaBackground: Attention deficit hyperactivity disorder (ADHD is a common neurodevelopmental disorder in school aged children. Functional abnormalities have been reported in brain imaging studies in ADHD populations. Psychostimulants are considered as the first line treatment for ADHD. However, little is known of the effect of stimulants on brain metabolites in ADHD patients.Objectives: To compare the brain metabolite concentrations in children with ADHD and on stimulants with those of drug naïve children with ADHD, versus typically developed children, in a homogenous genetic sample of French Canadians.Methods: Children with ADHD on stimulants (n=57 and drug naïve children with ADHD (n=45 were recruited, as well as typically developed children (n=38. The presence or absence of ADHD diagnosis (Diagnostic and Statistical Manual of Mental Disorders IV criteria was based on clinical evaluation and The Diagnostic Interview Schedule for Children IV. All children (n=140 underwent a proton magnetic resonance spectroscopy session to measure the ratio of N-acetyl-aspartate, choline, glutamate, and glutamate–glutamine to creatine, respectively, in the left and right prefrontal and striatal regions of the brain, as well as in the left cerebellum.Results: When compared with drug naïve children with ADHD, children with ADHD on stimulants and children typically developed were found to have higher choline ratios in the left prefrontal region (P=0.04 and lower N-acetyl-aspartate ratios in the left striatum region (P=0.01, as well as lower glutamate–glutamine ratios in the left cerebellum (P=0.05. In these three regions, there was no difference between children with ADHD on stimulants and typically developed children.Conclusion: Therapeutic psychostimulant effects in children with ADHD may be

  17. Thalamus in Patients with Obsessive-Compulsive Disorder:1H Magnetic Resonance Spectroscopy Study%丘脑1H磁共振波谱成像在强迫症中的应用

    尤超; 谭令; 范青; 丁蓓; 肖泽萍; 陈克敏

    2011-01-01

    目的 基于强迫症前额叶-纹状体-丘脑环路障碍假说,采用磁共振波谱成像(1H-MRS)研究成人强迫症(OCD)患者双侧丘脑1H-MRS表现及其与临床症状的关系.方法 13例经临床确诊的强迫症患者和与之相匹配的14例健康志愿者,分别行11.5TMRI的MRS检查,采用单体素点回波成像序列,采集双侧丘脑的波谱图像.所获图像经Sage软件后处理相应代谢指标N-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)、肌醇(Mi),测量NAA/Cr,Cho/Cr,Mi/Cr峰高相对值;并分析上述各值与OCD患者临床评分及病程时间的相关性.结果 与健康对照相比,OCD患者双侧丘脑的Mi/Cr、NAA/Cr明显降低,具有显著统计学差异;并且右侧丘脑NAA/Cr与强迫症病程时间呈负相关(r=-0.963,P<0.001).结论 OCD患者双侧丘脑NAA及Mi代谢物含量降低,1H-MRS可反映OCD患者丘脑代谢物的变化特征,并且可以证实OCD前额叶-纹状体-丘脑环路障碍的假说.%Objective On the basis of the hypothesis that patients with obsessive-compulsive disorder( OCD) have dysfunction of fronto-striato-thalamocortical circuitry, to study the metabolism change in the bilateral thalamic region with 1H magnetic resonance spectroscopy ( 1 H- MRS) and its correlations with clinical scale. Methods 13 patients with OCD and 14 matched healthy volunteers were enrolled in this study. Single voxel proton magnetic resonance spectroscopy was used to examine the bilateral thalamus for each subject. N-acetylaspartate(NAA), creatine(Cr), choline( Cho) and myo-inositol( mI) value of bilateral thalamus were acquired by using Sage software. Then the relativity of the MRS results and clinical scale were analyzed. Results A significant reduction in NAA/Cr and mI/Cr were observed in bilateral thalamus, and NAA/Cr of right thalamu was negative correlated with the course of OCD(r= -0. 963,P<0. 001). Conclusion Neuronal loss and NAA and ml decreased can be detected by using proton MRS in OCD

  18. Susceptibility effects in nuclear magnetic resonance imaging

    The properties of dephasing and the resulting relaxation of the magnetization are the basic principle on which all magnetic resonance imaging methods are based. The signal obtained from the gyrating spins is essentially determined by the properties of the considered tissue. Especially the susceptibility differences caused by magnetized materials (for example, deoxygenated blood, BOLD-effect) or magnetic nanoparticles are becoming more important for biomedical imaging. In the present work, the influence of such field inhomogeneities on the NMR-signal is analyzed. (orig.)

  19. Nuclear magnetic resonance spectroscopy in pancreatic disorders

    Ofer Kaplan

    1997-03-01

    Full Text Available Nuclear magnetic resonance spectroscopy (NMRS is a powerful technique that enables continuous monitoring of biochemical processes in tissues and organs in a non-invasive manner. A model of isolated perfused rat pancreas, suitable for NMRS studies, was developed. Acute pancreatitis was induced by injections of either 0.5 ml 5% sodium taurocholate (TC into the bile duets, or 1.0 ml 10% TC injections into the pancreatic parenchyma. Phosphorous (31P NMRS of experimental pancreatitis were characterized by a transient signal at -0.18±0.04 ppm which was assigned as solubilized lecithin, and can be used as an indicator of the early phases of the discase. Depletion of the high energy phosphorous compounds, phosphocreatine and ATP, were also found during acute pancreatitis, and paralleled the extension of the pathological damage. The role of NMRS in pancreatic cancer diagnosis and its treatment were assessed in three models of pancreatic neoplasms. Perfused MIA PaCa-2 human pancreatic cancer cells, subcutancously implanted pancreatic tumors in hamsters, and pancreatic tumors induced in-situ in rats by direct appiication of the carcinogen 7,12-dimethyl benzanthracene, were studied by phosphorous (31P, sodium (23Na and proton (¹H NMRS. 31P spectra of pancreatic cancer were qualitatively similar to those of intact organs. However, 31P NMRS was found to be useful for monitoring the effects of treatment. Total (infra- and extracellular sodium concentrations, measured in the solid tumors, were similar in both the normal pancreas and the pancreatic tumors (39-40 mmol/g wet weight. Proton spectra of perchloric acid extracts revealed several differences between tumors and control pancreases. The principal findings were elevated levels of the amino acid taurine, from I.17±O.39 mmol/g wet weight in healthy pancreases, to 2.79±0.71 mmol/g wet weight in pancreatic carcinoma in rats, and lactate levels which increased from 0.92±0.2 to 6.19±1.93 mmol/g wet weight

  20. New Approaches to Quantum Computing using Nuclear Magnetic Resonance Spectroscopy

    non-zero nuclear moments (spin 1/2 nuclei such as 1H or 13C) in an organic molecule dissolved in a solvent constitute the required qubits. The logic gates and algorithms correspond to set of instructions containing radio frequency (r.f) pulses and delays that manipulate the qubits and the final spectrum reflects the outcome of the algorithm. Three years ago, when we initiated proposal on NMR-QC, the foremost of the aim is to develop quantum computing as part of LLNL research programs and hence cultivate an interdisciplinary working group in the area of quantum computing. Our success in the proposal is in part responsible for the formation of the laboratory-wide exploratory group on ''quantum computing and information''. The PI's play an integral role in promoting the work performed using the LDRD funded project and hence acquire the attention within the lab as well outside. In specific goals of the project were to (a) develop experimental and sample based methods to improve the performance of NMR-QC, (b) define and estimate actual time cost or efficiency of a QCs, and (c) construct a comprehensive simulator of QC based on the principles of ensemble quantum computing. We were able to accomplish these goals and in particular we have reached some significant milestones in defining the QC efficiency and development of the QC-simulator. These developments have resulted to three publications

  1. LC-MS and 1H NMR as an improved dereplication tool to identify antifungal diterpenoids from Sagittaria latifolia

    A dereplication strategy using a combination of liquid chromatography-mass spectrometry (LC-MS) and proton nuclear magnetic resonance spectroscopy (1H NMR) to facilitate compound identification towards antifungal natural product discovery is presented. This analytical approach takes advantage of th...

  2. The emergence of proton nuclear magnetic resonance metabolomics in the cardiovascular arena as viewed from a clinical perspective.

    Rankin, Naomi J; Preiss, David; Welsh, Paul; Burgess, Karl E V; Nelson, Scott M; Lawlor, Debbie A; Sattar, Naveed

    2014-11-01

    The ability to phenotype metabolic profiles in serum has increased substantially in recent years with the advent of metabolomics. Metabolomics is the study of the metabolome, defined as those molecules with an atomic mass less than 1.5 kDa. There are two main metabolomics methods: mass spectrometry (MS) and proton nuclear magnetic resonance ((1)H NMR) spectroscopy, each with its respective benefits and limitations. MS has greater sensitivity and so can detect many more metabolites. However, its cost (especially when heavy labelled internal standards are required for absolute quantitation) and quality control is sub-optimal for large cohorts. (1)H NMR is less sensitive but sample preparation is generally faster and analysis times shorter, resulting in markedly lower analysis costs. (1)H NMR is robust, reproducible and can provide absolute quantitation of many metabolites. Of particular relevance to cardio-metabolic disease is the ability of (1)H NMR to provide detailed quantitative data on amino acids, fatty acids and other metabolites as well as lipoprotein subparticle concentrations and size. Early epidemiological studies suggest promise, however, this is an emerging field and more data is required before we can determine the clinical utility of these measures to improve disease prediction and treatment. This review describes the theoretical basis of (1)H NMR; compares MS and (1)H NMR and provides a tabular overview of recent (1)H NMR-based research findings in the atherosclerosis field, describing the design and scope of studies conducted to date. (1)H NMR metabolomics-CVD related research is emerging, however further large, robustly conducted prospective, genetic and intervention studies are needed to advance research on CVD risk prediction and to identify causal pathways amenable to intervention. PMID:25299963

  3. Measurements of the neutron electric to magnetic form-factor ratio GEn/GMn via the 2H((rvec e), e(prime)(rvec n)) 1H reaction to Q2 = 1.45-(GeV/c)2

    We report values for the neutron electric to magnetic form factor ratio, GEn/GMn, deduced from measurements of the neutron's recoil polarization in the quasielastic 2H((rvec e), e(prime)(rvec n)) 1H reaction, at three Q2 values of 0.45, 1.13, and 1.45 (GeV/c)2. The data at Q2 = 1.13 and 1.45 (GeV/c)2 are the first direct experimental measurements of GEn employing polarization degrees of freedom in the Q2 > 1 (GeV/c)2 region and stand as the most precise determinations of GEn for all values of Q2

  4. Determining diffusion coefficients of ionic liquids by means of field cycling nuclear magnetic resonance relaxometry

    Field Cycling Nuclear Magnetic Resonance (FC NMR) relaxation studies are reported for three ionic liquids: 1-ethyl-3- methylimidazolium thiocyanate (EMIM-SCN, 220–258 K), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF4, 243–318 K), and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF6, 258–323 K). The dispersion of 1H spin-lattice relaxation rate R1(ω) is measured in the frequency range of 10 kHz–20 MHz, and the studies are complemented by 19F spin-lattice relaxation measurements on BMIM-PF6 in the corresponding frequency range. From the 1H relaxation results self-diffusion coefficients for the cation in EMIM-SCN, BMIM-BF4, and BMIM-PF6 are determined. This is done by performing an analysis considering all relevant intra- and intermolecular relaxation contributions to the 1H spin-lattice relaxation as well as by benefiting from the universal low-frequency dispersion law characteristic of Fickian diffusion which yields, at low frequencies, a linear dependence of R1 on square root of frequency. From the 19F relaxation both anion and cation diffusion coefficients are determined for BMIM-PF6. The diffusion coefficients obtained from FC NMR relaxometry are in good agreement with results reported from pulsed- field-gradient NMR. This shows that NMR relaxometry can be considered as an alternative route of determining diffusion coefficients of both cations and anions in ionic liquids

  5. Nuclear magnetic resonance-based study reveals the metabolomics profile of nasopharyngeal carcinoma.

    Wang, Y; Luo, X; Zhang, G H; Li, S L

    2016-01-01

    Proton nuclear magnetic resonance ([(1)H]-NMR) spectroscopy has been used to investigate metabolites in serum and several types of tissue. We used NMR spectroscopy to explore the differential metabolic profiles in serum from nasopharyngeal carcinoma (NPC) patients. Moreover, metabolites with potential as biomarkers for identifying NPC patients were primarily identified. Serum samples were collected from 40 enrolled participants comprising 20 healthy subjects and 20 NPC patients. Samples were analyzed using a 600-MHz NMR spectrometer. The [(1)H]-NMR spectra were further analyzed with partial least squares-discriminant analysis for screening differential metabolites. NMR spectroscopy identified a total of eight metabolites that were present at different levels when the sera of NPC patients were compared with those of healthy individuals. Methionine, taurine (P < 0.05), and choline-like metabolites (P < 0.05) were mostly elevated in the sera of NPC patients. In contrast, the levels of lipids (P < 0.01), isoleucine (P < 0.05), unsaturated lipids (P < 0.01), trimethylamine oxidase (P < 0.05), and carbohydrates (P < 0.05) were lower in the sera of the NPC patients than in the healthy controls. We explored the differential metabolic profiles in sera from NPC patients. [(1)H]-NMR spectroscopy can be used to identify specific metabolites, and is capable of distinguishing between NPC patients and healthy individuals. PMID:27323073

  6. Source attribution of water-soluble organic aerosol by nuclear magnetic resonance spectroscopy.

    Decesari, Stefano; Mircea, Mihaiela; Cavalli, Fabrizia; Fuzzi, Sandro; Moretti, Fabio; Tagliavini, Emilio; Facchini, Maria Cristina

    2007-04-01

    The functional group compositions of atmospheric aerosol water-soluble organic compoundswere obtained employing proton nuclear magnetic resonance (1H NMR) spectroscopy in a series of recent experiments in several areas of the world characterized by different aerosol sources and pollution levels. Here, we discuss the possibility of using 1H NMR functional group distributions to identifythe sources of aerosol in the different areas. Despite the limited variability of functional group compositions of atmospheric aerosol samples, characteristic 1H NMR fingerprints were derived for three major aerosol sources: biomass burning, secondary formation from anthropogenic and biogenic VOCs, and emission from the ocean. The functional group patterns obtained in areas characterized by one of the above dominant source processes were then compared to identify the dominant sources for samples coming from mixed sources. This analysis shows that H NMR spectroscopy can profitably be used as a valuable tool for aerosol source identification. In addition, compared to other existing methodologies, it is able to relate the source fingerprints to integral chemical properties of the organic mixtures, which determine their reactivity and their physicochemical properties and ultimately the fate of the organic particles in the atmosphere. PMID:17438803

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

    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

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

    Tomimatsu, Toru, E-mail: tomimatsu@ils.uec.ac.jp; Shirai, Shota; Hashimoto, Katsushi, E-mail: hashi@m.tohoku.ac.jp; Sato, Ken [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Hirayama, Yoshiro [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2015-08-15

    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.

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

    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.

  10. Effective Giromagnetic Ratios in Artifical Nuclear Magnetization Pumping of the Noble Gases Mix

    Popov E.N.

    2015-01-01

    Full Text Available Dynamic of the nuclear magnetization of the two noble gases mix was studied in this research. Nuclear magnetization pumped along the induction of external magnetic field. Vector of nuclear magnetization is given a tilt by the week rotational magnetic field, which makes NMR for noble gases. Interaction between the nuclear magnetic moments of the different noble gases adducted to shifts at the frequency of nuclear moments precession in external magnetic field. Effective gyromagnetic ratios of the nuclear of noble gases is defined and it different from the tabulated value. There is theoretical calculation of effective gyromagnetic ratios in this research.

  11. 23Na and 1H NMR studies on melittin channels activated by tricyclic tranquilizers.

    Tanaka, H.; Matsunaga, K.; Kawazura, H

    1992-01-01

    A dynamic 23Na nuclear magnetic resonance (NMR) technique was applied to the exchange system of Na+ ions present inside and outside large unilamellar vesicles at an equivalent concentration. Addition of melittin to phosphatidylcholine vesicles did not induce any detectable Na+ transport across the membrane but subsequent addition of a trace of chlorpromazine or imipramine did induce Na+ transport. Because the formation of a drug-melittin adduct in a solution was detected by 1H NMR, the activa...

  12. Metabonomic signature analysis of cervical carcinoma and precancerous lesions in women by 1H NMR spectroscopy

    Hasim, Ayshamgul; ALI, MAYINUER; MAMTIMIN, BATUR; Ma, Jun-Qi; Li, Qiao-Zhi; ABUDULA, ABULIZI

    2012-01-01

    1H nuclear magnetic resonance (NMR)-based metabonomics has been used to characterize the metabolic profiles of cervical intraepithelial neoplasia (CIN) and cervical squamous cell carcinoma (CSCC). Principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) were used to model the systematic variation related to patients with CIN or CSCC with healthy controls. Potential metabolic biomarkers were identified using database comparisons, and the one-way a...

  13. Metabolic phenotyping of blood plasma by 1H-NMR spectroscopy to detect lung cancer?

    Louis,Evelyne; MESOTTEN, Liesbet; Thomeer, Michiel; Vanhove, Karolien; Vandeurzen, K.; Sadowska, A.; Reekmans, Gunter; Adriaensens, Peter

    2013-01-01

    Introduction. Lung cancer is the leading cause of cancer death worldwide. An effective method which allows to detect lung cancer is urgently needed. Accumulating evidence shows that the metabolism of cancer cells differs from that of normal cells(1). Disturbances in biochemical pathways which occur during the development of cancer provoke changes in the metabolic phenotype(2). Objective. To determine the metabolic phenotype of lung cancer by means of proton nuclear magnetic resonance (1H-...

  14. Magnet Design Considerations for Fusion Nuclear Science Facility

    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.

  15. Magnet design considerations for Fusion Nuclear Science Facility

    The Fusion Nuclear Science Facility (FNSF) is a nuclear confinement facility to provide a fusion environment with components of the reactor integrated together to bridge the technical gaps of burning plasma and nuclear science between ITER and the demonstration power plant (DEMO). Compared to ITER, the FNSF is smaller in size but generates much higher magnetic field, 30 times higher neutron fluence with 3 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 plasma major radius of 4.8 m and minor radius of 1.2 m, and a peak field of 15.5 T on the TF coils for FNSF. Both low temperature superconductor (LTS) and high temperature superconductor (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 Restack Rod Process (RRP) Nb3Sn strands for toroidal field (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. As a result, the material radiation limits for FNSF magnets are defined as part of the conceptual design studies for FNSF magnets

  16. Nuclear Magnetic Resonance imaging; Resonance magnetique nucleaire

    Thibierge, M.; Sevestre, L.; Slupecki, P. [Centre Hospitalier de Charleville-Mezieres, 08 (France)

    1998-06-01

    After many years of low profile business in the USA, MRI is back. Improvements are focused on high field magnets and on low field magnets. The former, are dedicated to high quality imaging. The new scanners are more and more efficient because of the spreading use of real time imaging. They can do now, procedures that just could not be imagined some years ago. Vascular imaging is done routinely. Abdominal imaging in apnea of EPI, perfusion and diffusion imaging, and, last not least, all the field of functional imaging are on the verge of coming out. The new magnets unveiled in 1997 are lighter, smaller, more, user friendly, less impressive for patients subject to claustrophobia. They also need less helium to operate and less space to be sited. The latter, are dedicated to interventional procedures. The new magnets are wide opened and a lot of companies show off. Though Picker unveiled a new light superconductive 0.5 Tesla magnet, it seems that this kind of machines are about to disappear. No significant progress was noticed in the field of dedicated MRI devices. Some features can be highlighted: the new Siemens short bore and its table integrates the Panoramic Array Coil Concept. It will allow simultaneous scanning with up to four coils; the excellent homogeneity of the new Picker magnet that will allow spectroscopy at 1 Tesla; the twin gradients of the Elscint Prisma that will open the field of microscopy MRI; the Philips `floppy gradients` that could speed up 4 or 6 times, the time needed for imaging; some new sequences sensitive to temperature are studied as WIP; a lot of work is achieved on 3 or 4 Tesla scanners etc. (author)

  17. Proton solid-state nuclear magnetic resonance studies of zeolite catalysts

    The goal of the research presented was to develop and demonstrate variable-temperature 1H magic-angle spinning (MAS) nuclear magnetic resonance (NMR) methods for the study of zeolites, both in the absence and presence of catalytically important adsorbates. This approach allowed simultaneous spectroscopic observation of both the catalyst and adsorbates. Reliable sample preparation techniques were developed which allowed routine characterization by NMR methods over a wide temperature range while preserving sample integrity. Other developments associated with this project including high-temperature NMR investigations of cracking chemistry, methods for sensitivity enhancement, and variable-temperature 1H combined rotation and multiple-pulse NMR spectroscopy are described. The structure and dynamics of hydrogen-bonded adsorption complexes between various adsorbates and the Bronsted acid site in zeolite H-ZSM5 were determined using variable-temperature 1H MAS NMR. The chemical shift of the Bronsted acid site was found to be extremely sensitive to the amount and type of molecule adsorbed. NMR experiments previously developed revealed a specific hydrogen-bonding interaction between the adsorbate and the strong acid site only. Quantitative treatment of the observed changes in the Bronsted chemical shift upon introduction of adsorbates resulted in the determination of equilibrium constants for the formation of the complex as well as hydrogen-bond distances. The spectroscopic properties of H-ZSM5 were characterized in detail using one- and two-dimensional MAS 1H NMR methods. These experiments revealed thermally-activated chemical exchange occurs between Bronsted acid protons and weakly acidic protons of the zeolite. Upon adsorption of ammonia, proton chemical exchange between all three types of protons was observed. These experiments revealed proton NMR spectroscopy may be used to monitor diffusion in zeolites on a macroscopic and microscopic level

  18. Contribution to studies of magnetic nuclear dipolar order

    The magnetic nuclear dipolar order concept is first introduced. Two original studies on the 19F spin system of CaF2 are then presented; the first deals with the behavior of a dipolar nuclear antiferromagnetic material in the presence of an effective nonnull field and leads to the determination of the ''field-entropy'' phase diagram of the system; the second study reveals the existence of rotating transverse structures

  19. Evaluation of nuclear magnetic resonance spectroscopy variability

    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)

  20. Evaluation of nuclear magnetic resonance spectroscopy variability

    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)

  1. Quantitative dosing by nuclear magnetic resonance

    The measurement of the absolute concentration of a heavy water reference containing approximately 99.8 per cent of D2O has been performed, by an original magnetic resonance method ('Adiabatic fast passage method') with a precision of 5.10-5 on the D2O concentration. (author)

  2. Solid state nuclear magnetic resonance: investigating the spins of nuclear related materials

    The author reviews his successive research works: his research thesis work on the Multiple Quantum Magic Angle Spinning (MQMAS) which is a quadric-polar nucleus multi-quanta correlation spectroscopy method, the modelling of NMR spectra of disordered materials, the application to materials of interest for the nuclear industry (notably the glasses used for nuclear waste containment). He presents the various research projects in which he is involved: storing glasses, nuclear magnetic resonance in paramagnetism, solid hydrogen storing matrices, methodological and instrument developments in high magnetic field and high resolution solid NMR, long range distance measurement by solid state Tritium NMR (observing the structure and dynamics of biological complex systems at work)

  3. Electron-nuclear magnetism of praseodymium and its compounds

    A consistent theory of electron-nuclear spin ordering in singlet magnetics is developed. The results of some recent experiments with PrNi5 are exlained. The effect of a magnetic field perpendicular to the basal plane on the phase transition is investigated. Depending on the magnitude of the exchange interaction, the magnetic field may either increase or decrease the transition temperature. An increase of the transition temperature on application of the field should occur, for example, in the hexagonal modification of praseodymium

  4. High Radiation Environment Nuclear Fragment Separator Magnet

    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

  5. Optimization and Construction of Single-side Nuclear Magnetic Resonance Magnet

    Ji Yongliang

    2013-10-01

    Full Text Available Single-sided NMR devices can operate under conditions inaccessible to conventional NMR while featuring portability and the ability to analyze arbitrary-sized objects. In this paper, a semi-elliptic Halbach magnet array was designed and built for single-side Nuclear Magnetic Resonance (NMR. We present an easy-to-implement target field algorithm for single-side NMR magnet design based on Gram-Schmidt Orthogonal method. The creating magnetic field of designed magnet structure could achieve best flatness in the region of interesting for NMR applications. The optimizing result shows that the best magnet structure can generate magnetic fields which flatly distributed in the horizontal direction and the gradient was distributed in the vertical direction with gradient of 2mT/mm. The field strength and gradient were measured by a three dimensions Hall probe and agreed well with the simulations.  

  6. Acoustic nuclear magnetic resonance in easy-axis antiferromagnets

    Obtained and investigated is the dispersion equation which shows that in the rouge of the tipping field at low temperatures the study of effects conditioned by the bond between the oscillations of electron and nuclear spins depends upon the fact, whethe the interaction of the sound with a nuclear spin subsystem is taken into account. The same concerns the effects conditioned by a strong bond between the oscillations of the lattice and electron spins. Shown is the effect of anisotropy of magnitostriction relative part on the nature of orientation phase transitions and the value of the coefficient of strengthening nuclear magnetic resonance

  7. The study of 1H-Magnetic resonance spectroscope (1H-MRS) in the anterior cingulate cortex (ACC) in depressive patients with childhood neglect%伴儿童期忽略的抑郁症患者前扣带回氢质子波谱对照研究

    彭红军; 李凌江; 贺忠

    2013-01-01

    目的 探讨伴儿童期忽略抑郁症患者前扣带回氢质子波谱物质代谢的特点.方法 采用儿童期创伤问卷(childhood trauma questionnaire,CTQ)对40例抑郁症患者进行儿童期忽略评估和分组,伴儿童期忽略抑郁症组19例患者和不伴儿童期忽略抑郁症组21例患者,以及20名正常对照行磁共振氢质子波谱(hydrogen magnetic resonance spectroscopy,1H-MRS)扫描,兴趣区选取双侧前扣带回(anterior cingulate cortex,ACC),检测N-乙酰天门冬氨酸(N-acetyl aspartate,NAA)、谷氨酸复合物(glutamate/glutamine,Glx)、胆碱(choline,Cho)、肌醇(myo-inositol,mI)及肌酸(creatine,Cr)水平,比较3组NAA/Cr、Glx/Cr、Cho/Cr和mI/Cr比值的差异.结果 伴与不伴儿童期忽略抑郁症组分别与对照组比较,左右两侧ACC均表现NAA/Cr降低(均P<0.010);2组右侧Glx/Cr均低于对照组(均P<0.001);伴儿童期忽略抑郁症组较不伴儿童期忽略抑郁症组左右两侧NAA/Cr差异均有统计学意义(左P<0.005,右P<0.01).结论 抑郁症患者前扣带回物质代谢不同于正常人;伴儿童期忽略抑郁症患者ACC的物质代谢存在特异性改变.

  8. Nuclear magnetic resonance imaging in brain tumors

    Full text: Magnetic resonance imaging (MRI) is a non-invasive imaging method based on the detecting signal from hydrogen nuclei of water molecules and fat. Performances of MRI are continuously increasing, and its domains of investigation of the human body are growing in both morphological and functional study. MRI also allows It also performing advanced management of tumours especially in the brain, by combining anatomical information (morphological MRI), functional (diffusion, perfusion and BOLD contrast) and metabolic (tissue composition in magnetic resonance spectroscopy (MRS)). The MRI techniques have an important role in cancerology. These techniques allow essential information for the diagnosis and answering therapist's questions before, during or after the treatment. The MR allows clarifying the localization of expanding processes, the differential diagnosis between brain tumour and a lesion confined by another structural aspect, the diagnosis of the tumoral aspect of a lesion, the histological ranking in case of glial tumour and the extension of its localization as well as the therapeutic follow-up (pre-therapeutic and post-therapeutics assessments). A better combination between the morphological, functional and metabolic studies, as well as integrating new technical developments, especially while using a multichannel bird cage coils the 3T magnet and suitable computing software, would allow significant improvements of the exploration strategies and management of brain tumors.

  9. Selection of planes in nuclear magnetic resonance tomography

    A prototype aiming to obtain images in nuclear magnetic resonance tomography was developed, by adjusting NMR spectrometer in the IFQSC Laboratory. The techniques for selecting planes were analysed by a set of computer codes, which were elaborated from Bloch equation solutions to simulate the spin system behaviour. Images were obtained using planes with thickness inferior to 1 cm. (M.C.K.)

  10. Nuclear magnetic response imaging of sap flow in plants

    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 k

  11. Yeast Lipid Estimation by Enzymatic and Nuclear Magnetic Resonance Methods

    Moreton, R. S.

    1989-01-01

    Low-resolution nuclear magnetic resonance and enzymatic glycerol estimation were compared with a solvent extraction method for estimating the intracellular lipid content of lipid-accumulating yeasts. Both methods correlated well with the solvent extraction procedure and were more convenient with large numbers of samples.

  12. Observation of the uranium 235 nuclear magnetic resonance signal

    Le Bail, H.; Chachaty, C.; Rigny, P.; Bougon, R.

    1983-01-01

    The first observation of the nuclear magnetic resonance of the uranium 235 is reported. It has been performed on pure liquid uranium hexafluoride at 380 K. The measured magnetogyric ratio is | γ(235U) | = 492.6 ± 0.2 rad.s-1 G-1.

  13. High resolution nuclear magnetic resonance spectroscopy (NMR studies on meat components: potentialities and prospects

    Antonio Sacco

    2010-01-01

    Full Text Available In recent years, increasing application of nuclear magnetic resonance (NMR spectroscopy in the study of the agricultur-  al food products has been remarked, thanks to the advantages of this technique over other conventional analytical tech-  niques. This preliminary work presents, for the first time, the application of an innovative NMR technique, the  proton  high resolution magic angle spinning (1H HR-MAS, for studying meat features. It stresses that this method makes it pos-  sible to acquire qualitative and quantitative information about chemical composition, both quickly and without any par-  ticular preparation of the sample to be analysed. Finally, the study highlights the potentiality of this method in defining  the origin of meat and the possibility of identifying meat adulteration. 

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

    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.

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

    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.

  16. General anesthesia for nuclear magnetic resonance imaging

    The core of the MAGNETOM diagnostic device is a liquid helium-cooled cryogenic magnet, having the shape of a hollow cylinder about 2 m long, 50 to 60 cm i.d. Its inner space is designed to accommodate a bench with the patient, whose part examined, usually the head, is enclosed in a smaller coil and is located roughly in the center of the magnet. The examination takes 4 to 20 minutes, during which the patient must be fixed to prevent any motion. Inhalation anesthesia with spontaneous ventilation using the Jackson-Rees or Bain's system and a laryngeal mask is considered the safest way where no special equipment is employed. If artificial ventilation is necessary, balanced anesthesia with either manual ventilation using Bain's system or a fluidic type ventilator seems to be the best choice. The preparation of the patient prior to the examination, the premedication, and the monitoring equipment are described. (J.B.). 1 tab., 5 figs., 11 refs

  17. Nuclear magnetic resonance imaging and prostatic cancer

    The diagnosis of prostatic cancer is histological. Apart from rectal examination, only imaging techniques allow evaluation of the extension of the cancer. Magnetic Resonance imaging (MRI) was performed with a Magniscan 5000 (Thomson C.G.R., France) apparatus. Three types of sequences were used: a short RT sequence (30/500, a multi-echo sequence with a long RT (40/2500) and echo gradient sequences (12 scans in less than 3 minutes). The MRI study of the pelvis is favoured by the abundance of fat which gives good contrast, spontaneous visualization of the vessels and the presence of the bladder with a high signal for urine in T2. This provides a very good anatomical study in three planes. In prostatic cancer, the study of the long sequence signal reveals heterogeneity of the prostatic signal on the second echo, but this is a non-specific variation. The staging of prostatic cancer is facilitated by scans in three planes. Different examples are presented in relation to various stages of the disease. Three clinical cases demonstrate that Magnetic Resonance may become an important element in the choice of treatment

  18. Characteristic properties of high- and low-spin-state five-coordinate σ-bonded aryl-, alkyl-, and perfluoroaryliron(III) porphyrins: 1H NMR, ESR, Moessbauer, and magnetic studies

    The magnetic behavior of σ-alkyliron(III) (or σ-aryliron(III)) porphyrins is studied in solution and in solution and in solid state by various spectroscopic methods: 1H NMR, ESR, and 57Fe Moessbauer spectroscopies. Variable-temperature magnetic susceptibility measurements were also performed on these complexes. The iron(III) atom of these compounds is present in different spin states. These are high (S = 5/2) or low spin (S = 1/2) at room temperature. Several factors can affect the spin state, the major parameter being the nature of the axial ligand. The perfluoroaryl axial groups (C6F4H, C6F5) lead to complexes in a pure high-spin state whatever the temperature. In contrast, the (P)Fe(R(Ar)) complexes where R = CH3, Ar = C6H5 and p-MeC6H4, and P = OEP, TPP, T(m-Me)PP, T(p-Me)PP, T(p-Et2N)PP, and (β-CN)4TPP behave differently and are in a low-spin state at room temperature. However, for the latter compounds in frozen solution or in the solid state, some high-spin sites are observed by ESR spectroscopy. The amount is critically dependent on the nature of the axial and porphyrin ligands. Moreover, the solvent matrix appears very important. In the solid state and on the basis of ESR data, the spin mixture could be slightly modified by grinding of the crystalline sample, leading to high-spin entity increase. The effect of these parameters is examined with respect to the nature of the metal-porphyrin and metal-ligand bond. Correlations between stereochemistry, spin state, and the nature of ligands are discussed. 64 refs., 9 figs., 8 tabs

  19. Differentiation of Organically and Conventionally Grown Tomatoes by Chemometric Analysis of Combined Data from Proton Nuclear Magnetic Resonance and Mid-infrared Spectroscopy and Stable Isotope Analysis.

    Hohmann, Monika; Monakhova, Yulia; Erich, Sarah; Christoph, Norbert; Wachter, Helmut; Holzgrabe, Ulrike

    2015-11-01

    Because the basic suitability of proton nuclear magnetic resonance spectroscopy ((1)H NMR) to differentiate organic versus conventional tomatoes was recently proven, the approach to optimize (1)H NMR classification models (comprising overall 205 authentic tomato samples) by including additional data of isotope ratio mass spectrometry (IRMS, δ(13)C, δ(15)N, and δ(18)O) and mid-infrared (MIR) spectroscopy was assessed. Both individual and combined analytical methods ((1)H NMR + MIR, (1)H NMR + IRMS, MIR + IRMS, and (1)H NMR + MIR + IRMS) were examined using principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), linear discriminant analysis (LDA), and common components and specific weight analysis (ComDim). With regard to classification abilities, fused data of (1)H NMR + MIR + IRMS yielded better validation results (ranging between 95.0 and 100.0%) than individual methods ((1)H NMR, 91.3-100%; MIR, 75.6-91.7%), suggesting that the combined examination of analytical profiles enhances authentication of organically produced tomatoes. PMID:26457410

  20. Potential of human saliva for nuclear magnetic resonance-based metabolomics and for health-related biomarker identification

    Bertram, Hanne Christine; Eggers, Nina; Eller, Nanna

    2009-01-01

    In the present study, the ability of (1)H nuclear magnetic resonance (NMR) for metabolic profiling of human saliva samples was investigated. High-resolution (1)H NMR spectra were obtained, and signals were assigned to various metabolites mainly representing small organic acids and amino acids. In...... addition, the use of human saliva for metabolomic studies was evaluated, and multivariate data analysis revealed that the 92 morning and night samples from 46 subjects could be discriminated with a predictability of 85%. The diurnal effect on the salivary metabolite profile were ascribed to changes in...... intensities of several metabolites including trimethylamine oxide (TMAO), choline, propionate, alanine, methanol, and N-acetyl groups. No effects of gender and body mass index (BMI) on the salivary metabolite profile were detected. The relationships between the salivary metabolome and glycated hemoglobin...

  1. Sunflower oil ozonation. Following of the reaction by proton Nuclear Magnetic Resonance

    Previous studies have demonstrated that the technique of Proton Nuclear Magnetic Resonance can be used for the pursuit of the reaction between the ozone and the unsaturated fatty acids. It's carried out the sunflower oil ozonization to different applied dose of ozone and the index of peroxides and the concentration of aldehydes are determined. The main reaction products were identified by Proton Nuclear Magnetic Resonance Spectroscopy (NMR 1 H). The intensities of the signs were used to follow the advance of the reaction between the ozone and the sunflower oil. It is was carried out until obtaining an index of peroxides of 1 202 mmol-equiv/kg. The intensities of the signs of the olefinic protons diminish with a gradual increment in the dose of applied ozone, but without ending up disappearing completely. The ozonides of Criegee obtained to applied dose of ozone of 107,1 mg/g were approximately bigger 7,4 times that those obtained at the beginning from the reaction to applied dose of ozone of 15,3 mg/g. The aldehydes protons were observed as a sign of weak intensity in all the spectra. The signs belonging to the olenifics protons of the hydroperoxides in d = 5,55 ppm increases with the increment of the applied dose of ozone. You concludes that to higher applied dose of ozone, haggler is the advance of the ozonization reaction, what belongs together with a bigger formation of oxygenated compounds

  2. Nuclear magnetic resonance spectroscopy for determining the functional content of organic aerosols: A review

    The knowledge deficit of organic aerosol (OA) composition has been identified as the most important factor limiting our understanding of the atmospheric fate and implications of aerosol. The efforts to chemically characterize OA include the increasing utilization of nuclear magnetic resonance spectroscopy (NMR). Since 1998, the functional composition of different types, sizes and fractions of OA has been studied with one-dimensional, two-dimensional and solid state proton and carbon-13 NMR. This led to the use of functional group ratios to reconcile the most important sources of OA, including secondary organic aerosol and initial source apportionment using positive matrix factorization. Future research efforts may be directed towards the optimization of experimental parameters, detailed NMR experiments and analysis by pattern recognition methods to identify the chemical components, determination of the NMR fingerprints of OA sources and solid state NMR to study the content of OA as a whole. - Highlights: • Organic aerosol composition by 1H- and 13C-NMR spectroscopy. • NMR fingerprints of specific sources, types and sizes of organic aerosol. • Source reconciliation and apportionment using NMR spectroscopy. • Research priorities towards understanding organic aerosol composition and origin. - This review presents the recent advances on the characterization of organic aerosol composition using nuclear magnetic resonance spectroscopy

  3. Nuclear magnetic resonance studies of biological systems

    The difference between intracellular and extracellular proton relaxation rates provides the basis for the determination of the mean hemoglobin concentration (MHC) in red blood cells. The observed water T1 relaxation data from red blood cell samples under various conditions were fit to the complete equation for the time-dependent decay of magnetization for a two-compartment system including chemical exchange. The MHC for each sample was calculated from the hematocrit and the intracellular water fraction as determined by NMR. The binding of the phosphorylcholine (PC) analogue, 2-(trimethylphosphonio)-ethylphosphate (phosphoryl-phosphocholine, PPC) to the PC binding myeloma proteins TEPC-15, McPC 603, and MOPC 167 was studied by 31P NMR

  4. Nuclear magnetic resonance imaging at microscopic resolution

    Johnson, G. Allan; Thompson, Morrow B.; Gewalt, Sally L.; Hayes, Cecil E.

    Resolution limits in NMR imaging are imposed by bandwidth considerations, available magnetic gradients for spatial encoding, and signal to noise. This work reports modification of a clinical NMR imaging device with picture elements of 500 × 500 × 5000 μm to yield picture elements of 50 × 50 × 1000 μm. Resolution has been increased by using smaller gradient coils permitting gradient fields >0.4 mT/cm. Significant improvements in signal to noise are achieved with smaller rf coils, close attention to choice of bandwidth, and signal averaging. These improvements permit visualization of anatomical structures in the rat brain with an effective diameter of 1 cm with the same definition as is seen in human imaging. The techniques and instrumentation should open a number of basic sciences such as embryology, plant sciences, and teratology to the potentials of NMR imaging.

  5. Enhanced Nuclear Magnetism: Some Novel Features and Prospective Experiments

    Abragam, A.; Bleaney, B.

    1983-06-01

    This review of enhanced nuclear magnetism discusses a number of features not previously considered, with special reference to new experiments that use dynamic methods to produce high nuclear polarization, followed by adiabatic demagnetization in the rotating frame (a.d.r.f.) to produce nuclear ordered states that may be investigated by the scattering of beams of neutrons. Section 2. The 'enhancement' of the nuclear moment arises from the electronic magnetization M_I induced through the hyperfine interaction. It is shown that the spatial distribution of M_I is the same as that of M_H, the Van Vleck magnetization induced by an external field, provided that J is a good quantum number. The spatial distributions are not in general the same in Russell-Saunders coupling, e.g. in the 3d group. Section 3. The Bloch equations are extended to include anisotropic nuclear moments. Section 4. The 'truncated' spin Hamiltonian is derived for spin-spin interaction between enhanced moments. Section 5. A general cancellation theorem for second-order processes in spin-lattice relaxation is derived, showing that the intrinsic direct process must be of third order. The relaxation rate obeys an equation similar to that for Kramers electronic ions, but reduced as the fifth power of the resonance frequencies. The relaxation rates observed experimentally (except in very high fields) are ascribed to paramagnetic impurities, so that these can be used to produce dynamic nuclear polarization (d.n.p.). Section 6. The interactions of neutrons with the true nuclear moment μ_I, the Van Vleck moment M_H, the 'pseudonuclear' moment M_I and the 'pseudomagnetic' nuclear moment μ *_I are discussed. It is shown that the four contributions can be observed separately by measurement of the form factor for neutron scattering as a function of temperature and direction of the applied magnetic field. Precession of the neutron spin in the 'pseudomagnetic' field H* is discussed with reference to the case of Ho

  6. Windowed direct exponential curve resolution quantification of nuclear magnetic resonance spectroscopy with applications to amniotic fluid metabonomics

    Botros, L.L

    2007-07-01

    This thesis presents a quantitative protocol of proton nuclear magnetic resonance ({sup 1}H NMR) that allows the determination of human amniotic fluid metabolite concentrations, which are then used in a metabonomic study to establish patient health during gestation. {sup 1}H NMR free inductive decays (FIDs) of 258 human amniotic fluid samples from a 500MHz spectrometer are acquired. Quantitative analyses methods in both the frequency- and time-domain are carried out and compared. Frequency-domain analysis is accomplished by integration of the metabolite peaks before and after the inclusion of a known standard addition of alanine. Time-domain analysis is accomplished by the direct exponential curve resolution algorithm (DECRA). Both techniques are assessed by applications to calibration biological solutions and a simulated data set. The DECRA method proves to be a more accurate and precise route for quantitative analysis, and is included in the developed protocol. Well-defined peaks of various components are visible in the frequency-domain {sup 1}H NMR spectra, including lactate, alanine, acetate, citrate, choline, glycine, and glucose. All are quantified with the proposed protocol. Statistical t-test and notched box and whisker plots are used to compare means of metabolite concentrations for diabetic and normal patients. Glucose, glycine, and choline are all found to correlate with gestational diabetes mellitus early in gestation. With further development, time-domain quantitative {sup 1}H NMR has potential to become a robust diagnostic tool for gestational health. (author)

  7. Windowed direct exponential curve resolution quantification of nuclear magnetic resonance spectroscopy with applications to amniotic fluid metabonomics

    This thesis presents a quantitative protocol of proton nuclear magnetic resonance (1H NMR) that allows the determination of human amniotic fluid metabolite concentrations, which are then used in a metabonomic study to establish patient health during gestation. 1H NMR free inductive decays (FIDs) of 258 human amniotic fluid samples from a 500MHz spectrometer are acquired. Quantitative analyses methods in both the frequency- and time-domain are carried out and compared. Frequency-domain analysis is accomplished by integration of the metabolite peaks before and after the inclusion of a known standard addition of alanine. Time-domain analysis is accomplished by the direct exponential curve resolution algorithm (DECRA). Both techniques are assessed by applications to calibration biological solutions and a simulated data set. The DECRA method proves to be a more accurate and precise route for quantitative analysis, and is included in the developed protocol. Well-defined peaks of various components are visible in the frequency-domain 1H NMR spectra, including lactate, alanine, acetate, citrate, choline, glycine, and glucose. All are quantified with the proposed protocol. Statistical t-test and notched box and whisker plots are used to compare means of metabolite concentrations for diabetic and normal patients. Glucose, glycine, and choline are all found to correlate with gestational diabetes mellitus early in gestation. With further development, time-domain quantitative 1H NMR has potential to become a robust diagnostic tool for gestational health. (author)

  8. Characterization of urban aerosol using aerosol mass spectrometry and proton nuclear magnetic resonance spectroscopy

    Cleveland, M. J.; Ziemba, L. D.; Griffin, R. J.; Dibb, J. E.; Anderson, C. H.; Lefer, B.; Rappenglück, B.

    2012-07-01

    Particulate matter was measured during August and September of 2006 in Houston as part of the Texas Air Quality Study II Radical and Aerosol Measurement Project. Aerosol size and composition were determined using an Aerodyne quadrupole aerosol mass spectrometer. Aerosol was dominated by sulfate (4.1 ± 2.6 μg m-3) and organic material (5.5 ± 4.0 μg m-3), with contributions of organic material from both primary (˜32%) and secondary (˜68%) sources. Secondary organic aerosol appears to be formed locally. In addition, 29 aerosol filter samples were analyzed using proton nuclear magnetic resonance (1H NMR) spectroscopy to determine relative concentrations of organic functional groups. Houston aerosols are less oxidized than those observed elsewhere, with smaller relative contributions of carbon-oxygen double bonds. These particles do not fit 1H NMR source apportionment fingerprints for identification of secondary, marine, and biomass burning organic aerosol, suggesting that a new fingerprint for highly urbanized and industrially influenced locations be established.

  9. Nuclear magnetic resonance in pulse radiolysis. Chemically induced dynamic nuclear polarization

    Nuclear magnetic resonance and chemically induced dynamic nuclear polarization (CIDNP) were applied to the study of pulse radiolysis. Samples were irradiated with a 3-MeV electron beam from the Argonne Van de Graaff accelerator in an EPR magnet (approximately 4000 G) which had axial holes for beam access. A fast flow system transferred the irradiated solution to the rotating 5-mm NMR sample tube. The NMR spectra of mixtures of sodium acetate and methanol were presented to demonstrate the features of the CIDNP in pulse radiolysis

  10. Nuclear magnetic resonance method for observation of ferromagnetic pulmonary contaminants

    A method is proposed for measurement of tissue concentration of asbestos and other contaminants containing magnetite. The method uses nuclear magnetic resonance (NMR) of protons as a means of detection of the magnetic particles present in the dust. Results of the study of the effect of concentration of iron particles and particle size on the NMR signal are presented. The NMR signal had linear relationship to the concentration particles. Experiments with different particle size indicated that the signal was proportional to the mass of particles rather than to their number. Quantitative detection of 7RF02 chrysotile asbestos in gel and in rat lungs was demonstrated

  11. Algorithmic cooling in liquid-state nuclear magnetic resonance

    Atia, Yosi; Elias, Yuval; Mor, Tal; Weinstein, Yossi

    2016-01-01

    Algorithmic cooling is a method that employs thermalization to increase qubit purification level; namely, it reduces the qubit system's entropy. We utilized gradient ascent pulse engineering, an optimal control algorithm, to implement algorithmic cooling in liquid-state nuclear magnetic resonance. Various cooling algorithms were applied onto the three qubits of C132-trichloroethylene, cooling the system beyond Shannon's entropy bound in several different ways. In particular, in one experiment a carbon qubit was cooled by a factor of 4.61. This work is a step towards potentially integrating tools of NMR quantum computing into in vivo magnetic-resonance spectroscopy.

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

    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. PMID:10335581

  13. Determining diffusion coefficients of ionic liquids by means of field cycling nuclear magnetic resonance relaxometry

    Kruk, D. [Faculty of Mathematics and Computer Science, University of Warmia and Mazury in Olsztyn, Słoneczna 54, PL-10710 Olsztyn (Poland); Universität Bayreuth, Experimentalphysik II, 95440 Bayreuth (Germany); Meier, R.; Rössler, E. A. [Universität Bayreuth, Experimentalphysik II, 95440 Bayreuth (Germany); Rachocki, A. [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań (Poland); Korpała, A. [Department of Biophysics, Jagiellonian University Medical College, Łazarza 16, 31-530 Kraków, Poland and Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków (Poland); Singh, R. K. [Ionic Liquid and Solid State Ionics Laboratory, Department of Physics, Banaras Hindu University, Varanasi 221 005 (India)

    2014-06-28

    Field Cycling Nuclear Magnetic Resonance (FC NMR) relaxation studies are reported for three ionic liquids: 1-ethyl-3- methylimidazolium thiocyanate (EMIM-SCN, 220–258 K), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM-BF{sub 4}, 243–318 K), and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIM-PF{sub 6}, 258–323 K). The dispersion of {sup 1}H spin-lattice relaxation rate R{sub 1}(ω) is measured in the frequency range of 10 kHz–20 MHz, and the studies are complemented by {sup 19}F spin-lattice relaxation measurements on BMIM-PF{sub 6} in the corresponding frequency range. From the {sup 1}H relaxation results self-diffusion coefficients for the cation in EMIM-SCN, BMIM-BF{sub 4}, and BMIM-PF{sub 6} are determined. This is done by performing an analysis considering all relevant intra- and intermolecular relaxation contributions to the {sup 1}H spin-lattice relaxation as well as by benefiting from the universal low-frequency dispersion law characteristic of Fickian diffusion which yields, at low frequencies, a linear dependence of R{sub 1} on square root of frequency. From the {sup 19}F relaxation both anion and cation diffusion coefficients are determined for BMIM-PF{sub 6}. The diffusion coefficients obtained from FC NMR relaxometry are in good agreement with results reported from pulsed- field-gradient NMR. This shows that NMR relaxometry can be considered as an alternative route of determining diffusion coefficients of both cations and anions in ionic liquids.

  14. Solid state nuclear magnetic resonance investigations of advanced energy materials

    Bennett, George D.

    In order to better understand the physical electrochemical changes that take place in lithium ion batteries and asymmetric hybrid supercapacitors solid state nuclear magnetic resonance (NMR) spectroscopy has been useful to probe and identify changes on the atomic and molecular level. NMR is used to characterize the local environment and investigate the dynamical properties of materials used in electrochemical storage devices (ESD). NMR investigations was used to better understand the chemical composition of the solid electrolyte interphase which form on the negative and positive electrodes of lithium batteries as well as identify the breakdown products that occur in the operation of the asymmetric hybrid supercapacitors. The use of nano-structured particles in the development of new materials causes changes in the electrical, structural and other material properties. NMR was used to investigate the affects of fluorinated and non fluorinated single wall nanotubes (SWNT). In this thesis three experiments were performed using solid state NMR samples to better characterize them. The electrochemical reactions of a lithium ion battery determine its operational profile. Numerous means have been employed to enhance battery cycle life and operating temperature range. One primary means is the choice and makeup of the electrolyte. This study focuses on the characteristics of the solid electrolyte interphase (SEI) that is formed on the electrodes surface during the charge discharge cycle. The electrolyte in this study was altered with several additives in order to determine the influence of the additives on SEI formation as well as the intercalation and de-intercalation of lithium ions in the electrodes. 7Li NMR studies where used to characterize the SEI and its composition. Solid state NMR studies of the carbon enriched acetonitrile electrolyte in a nonaqueous asymmetric hybrid supercapacitor were performed. Magic angle spinning (MAS) coupled with cross polarization NMR

  15. Identification, synthesis and characterization of an unknown process related impurity in eslicarbazepine acetate active pharmaceutical ingredient by LC/ESI–IT/MS, 1H, 13C and 1H–1H COSY NMR

    Saji Thomas

    2014-10-01

    Full Text Available A new impurity was detected during high performance liquid chromatographic (HPLC analysis of eslicarbazepine acetate active pharmaceutical ingredient. The structure of unknown impurity was postulated based on liquid chromatography mass spectrometry using electrospray ionization and ion trap analyzer (LC/ESI–IT/MS analysis. Proposed structure of impurity was unambiguously confirmed by synthesis followed by characterization using 1H, 13C nuclear magnetic resonance spectrometry (NMR, 1H–1H correlation spectroscopy (COSY and infrared spectroscopy (IR. Based on the spectroscopic and spectrometric data, unknown impurity was characterized as 5-carbamoyl-10,11-dihydro-5H-dibenzo[b,f]azepin-10-yl propionate.

  16. The Use and Evaluation of Scaffolding, Student Centered-Learning, Behaviorism, and Constructivism to Teach Nuclear Magnetic Resonance and IR Spectroscopy in a Two-Semester Organic Chemistry Course

    Livengood, Kimberly; Lewallen, Denver W.; Leatherman, Jennifer; Maxwell, Janet L.

    2012-01-01

    Since 2002, infrared spectroscopy (IR) and nuclear magnetic resonance (NMR) spectrometry have been introduced at the beginning of the first-semester organic chemistry lab course at this university. Starting in 2008, each individual student was given 20 unique homework problems that consisted of multiple-choice [superscript 1]H NMR and IR problems…

  17. Nuclear chiral and magnetic rotation in covariant density functional theory

    Meng, Jie; Zhao, Pengwei

    2016-05-01

    Excitations of chiral rotation observed in triaxial nuclei and magnetic and/or antimagnetic rotations (AMR) seen in near-spherical nuclei have attracted a lot of attention. Unlike conventional rotation in well-deformed or superdeformed nuclei, here the rotational axis is not necessary coinciding with any principal axis of the nuclear density distribution. Thus, tilted axis cranking (TAC) is mandatory to describe these excitations self-consistently in the framework of covariant density functional theory (CDFT). We will briefly introduce the formalism of TAC–CDFT and its application for magnetic and AMR phenomena. Configuration-fixed CDFT and its predictions for nuclear chiral configurations and for favorable triaxial deformation parameters are also presented, and the discoveries of the multiple chiral doublets in 133Ce and 103Rh are discussed.

  18. Nuclear chiral and magnetic rotation in covariant density functional theory

    Meng, Jie

    2016-01-01

    Excitations of chiral rotation observed in triaxial nuclei and magnetic and/or antimagnetic rotations seen in near-spherical nuclei have attracted a lot of attention. Unlike conventional rotation in well-deformed or superdeformed nuclei, here the rotational axis is not necessary coinciding with any principal axis of the nuclear density distribution. Thus, tilted axis cranking is mandatory to describe these excitations self-consistently in the framework of covariant density functional theory (CDFT). We will briefly introduce the formalism of tilted axis cranking CDFT and its application for magnetic and antimagnetic rotation phenomena. Configuration-fixed CDFT and its predictions for nuclear chiral configurations and for favorable triaxial deformation parameters are also presented, and the discoveries of the multiple chiral doublets (M\\c{hi}D) in 133Ce and 103Rh are discussed.

  19. Clinical applications of nuclear magnetic resonance spectroscopy: a review

    The advantages and present limitations of the clinical applications of nuclear magnetic resonance spectroscopy are reviewed in outline, with passing references to skeletal muscular studies, in particular a group of children with advanced Duchenne dystrophy, and the applications to the study of cerebral metabolism of neonates, excised kidneys, biopsy studies of breast and axillary lymph node samples, and NMR spectroscopy performed during chemotherapy of a secondary rhabdomyosarcoma in the skin. (U.K.)

  20. Nuclear magnetic response imaging of sap flow in plants

    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 known about the dynamics of long distance transport inside the living plant. The latter is caused by the fact that the two pathways in which transport takes place, the xylem and the phloem, are virt...

  1. Nuclear magnetic resonance in LaNi/sub 5/

    Rubinstein, M.; Swartzendruber, L.J.; Bennett, L.H.

    1979-03-01

    Proton and La/sup 139/ nuclear magnetic resonance measurements have been performed on LaNi/sub 5/, LaNi/sub 5/ hydrides, and LaNi/sub 5/H/sub x/ with ternary additions. With ternary additions, the activation energy for proton diffusion remained unchanged, but the motionally narrowed linewidth broadened. The quadrupole interaction on the La site has been determined in LaNi/sub 5/ and LaNi/sub 5/H/sub x/.

  2. Science and history explored by nuclear magnetic resonance

    Baias, Maria Antoaneta

    2009-01-01

    Nuclear Magnetic Resonance was chosen as the main tool for investigating different biological and chemical systems, as it is unique in providing the information details about the morphology and molecular structures and conformations by which the fundamental properties of these biological and chemical systems can be understood. Proton spin-diffusion experiments combined with 13C CPMAS spectroscopy were successfully applied to characterize the changes that occur during the thermal denaturation ...

  3. Experimental Implementation of Remote State Preparation by Nuclear Magnetic Resonance

    Peng, Xinhua; Zhu, Xiwen; Fang, Ximing; Feng, Mang; Liu, Maili; Gao, Kelin

    2002-01-01

    We have experimentally implemented remote state preparation (RSP) of a qubit from a hydrogen to a carbon nucleus in molecules of carbon-13 labeled chloroform $^{13}$CHCl$_{3}$ over interatomic distances using liquid-state nuclear magnetic resonance (NMR) technique. Full RSP of a special ensemble of qubits, i.e., a qubit chosen from equatorial and polar great circles on a Bloch sphere with Pati's scheme, was achieved with one cbit communication. Such a RSP scheme can be generalized to prepare ...

  4. Experimental implementation of remote state preparation by nuclear magnetic resonance

    Peng Xinhua; Zhu Xiwen; Fang Ximing; Feng Mang; Liu Maili; Gao Kelin

    2003-01-13

    We have experimentally implemented remote state preparation of a qubit from a hydrogen to a carbon nucleus in molecules of carbon-13 labeled chloroform {sup 13}CHCl{sub 3} over interatomic distances using liquid-state nuclear magnetic resonance techniques. Full RSP of a special ensemble of qubits, i.e., a qubit chosen from either an equatorial or a polar great circle on a Bloch sphere with Pati's scheme, was achieved with one cbit communication.

  5. PWM high frequency oscillator in Nuclear Magnetic Resonance

    In this article we propose a new architecture for pulsed oscillator, in the area of radio frequency (RF), which operates with pulses of few microseconds in spectrometers of Nuclear Magnetic Resonance Pulsed. This new topology substitutes the classic amplifying systems with valves by field effect semiconductors of the type MOS-FET channel N, allowing a larger compacting and efficiency. This oscillator possibly reaching potencies of the order of 103 Watts at a low cost. (author)

  6. Optimal grouping for a nuclear magnetic resonance (NMR) scanner

    VANDAELE, Nico; VAN NIEUWENHUYSE, Inneke; CUPERS, Sascha

    2001-01-01

    In this paper we analyze how a Nuclear Magnetic Resonance Scanner can be managed more efficiently, simultaneously improving patient comfort (in terms of total time spent in the system) and increasing availability in case of emergency calls. By means of a superposition approach, all relevant data on the arrival and service process of different patient types are transformed into a general single server, single class queueing model. The objective function consists of the weighted average patient...

  7. Nonadiabatic Geometric Angle in Nuclear Magnetic Resonance Connection

    Cherbal, Omar; Maamache, Mustapha; Drir, Mahrez

    2005-01-01

    By using the Grassmannian invariant-angle coherents states approach, the classical analogue of the Aharonov-Anandan nonadiabatic geometrical phase is found for a spin one-half in Nuclear Magnetic Resonance (NMR). In the adiabatic limit, the semi-classical relation between the adiabatic Berry’s phase and Hannay’s angle gives exactly the experimental result observed by Suter et al[12].

  8. Fat fraction value measured by proton magnetic resonance spectroscopy in osteoporosis:a Meta analysis%骨质疏松症1H-MRS脂肪分数定量研究:Meta分析

    张慈慈; 沈思; 汪飞; 邱麟; 刘斯润

    2015-01-01

    Objective To have a systemic review of the association between fat fraction value measured by proton magnetic resonance spectroscopy and osteoporosis bone mineral density, and to explore if fat fraction can be a reliable indicator for the diagnosis osteoporosis like bone mineral density. Methods Pubmed, Cochrane library, Medline, and China National Knowledge Infrastructure (CNKI) datebases (from January, 2000 to December, 2014) were searched to collect articles about proton magnetic resonance spectroscopy assessing osteoporosis. The data of fat fraction in osteoporosis group and normal group and Pearson correlation coefficient between bone mineral density and fat fraction were extracted from the articles. Pooled weighted mean difference (WMD) and 95%confidence interval, Pearson correlation coefficient between bone mineral density and fat fraction were done using review manager 5. 0 software. Results Nine articles (seven English articles, two Chinese articles) were included with 499 cases (210 normal and 289 osteoporosis). The fat fraction value was higher in osteoporosis than normal (WMD 9.25, 95%CI:6.95 to 11.56). A negative correlation was found between fat fraction value and bone mineral density (-0.59,95%CI:-0.76~-0.42). Conclusion Fat fraction measured by Proton magnetic resonance spectroscopy has certain clinical value in the assessment of osteoporosis, it can be used as a supplemental examination of DXA. Whether it can be a reliable indicator for the diagnosis osteoporosis like bone mineral density, the feasibility and accuracy need more research.%目的:采用Meta 分析的方法综合评价1H-MRS 相对定量指标脂肪分数与骨质疏松症骨密度的关系,探索脂肪分数能否如骨密度一样成为诊断骨质疏松症的可靠指标。方法检索 Pubmed、Cochrane 图书馆、Medline、中国知网(CNKI)等数据库中2000年1月—2014年12月公开发表的有关1H-MRS评价骨质疏松的中英文文献,提取文献中骨质疏

  9. Magnetic Flux Compression Concept for Nuclear Pulse Propulsion and Power

    Litchford, Ronald J.

    2000-01-01

    The desire for fast, efficient interplanetary transport requires propulsion systems having short acceleration times and very high specific impulse attributes. Unfortunately, most highly efficient propulsion systems which are within the capabilities of present day technologies are either very heavy or yield very low impulse such that the acceleration time to final velocity is too long to be of lasting interest, One exception, the nuclear thermal thruster, could achieve the desired acceleration but it would require inordinately large mass ratios to reach the range of desired final velocities. An alternative approach, among several competing concepts that are beyond our modern technical capabilities, is a pulsed thermonuclear device utilizing microfusion detonations. In this paper, we examine the feasibility of an innovative magnetic flux compression concept for utilizing microfusion detonations, assuming that such low yield nuclear bursts can be realized in practice. In this concept, a magnetic field is compressed between an expanding detonation driven diamagnetic plasma and a stationary structure formed from a high temperature superconductor (HTSC). In general, we are interested in accomplishing two important functions: (1) collimation of a hot diamagnetic plasma for direct thrust production; and (2) pulse power generation for dense plasma ignition. For the purposes of this research, it is assumed that rnicrofusion detonation technology may become available within a few decades, and that this approach could capitalize on recent advances in inertial confinement fusion ICF) technologies including magnetized target concepts and antimatter initiated nuclear detonations. The charged particle expansion velocity in these detonations can be on the order of 10 (exp 6)- 10 (exp 7) meters per second, and, if effectively collimated by a magnetic nozzle, can yield the Isp and the acceleration levels needed for practical interplanetary spaceflight. The ability to ignite pure

  10. Quantitative velocity distributions via nuclear magnetic resonance flow metering

    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.

  11. Imaging using long range dipolar field effects Nuclear magnetic resonance

    Gutteridge, S

    2002-01-01

    The work in this thesis has been undertaken by the except where indicated in reference, within the Magnetic Resonance Centre, at the University of Nottingham during the period from October 1998 to March 2001. This thesis details the different characteristics of the long range dipolar field and its application to magnetic resonance imaging. The long range dipolar field is usually neglected in nuclear magnetic resonance experiments, as molecular tumbling decouples its effect at short distances. However, in highly polarised samples residual long range components have a significant effect on the evolution of the magnetisation, giving rise to multiple spin echoes and unexpected quantum coherences. Three applications utilising these dipolar field effects are documented in this thesis. The first demonstrates the spatial sensitivity of the signal generated via dipolar field effects in structured liquid state samples. The second utilises the signal produced by the dipolar field to create proton spin density maps. Thes...

  12. Design and construction of a nuclear magnetic resonator circuit

    It is described the operation of a feedback circuit that it using the nuclear resonance phenomena and that covers a broad sweeping interval in frequency with a minimum adjustment of the circuit elements and it produces an appropriate nuclear absorption for a sign relation at reasonable noise. The circuit is an oscillator amplifier modulated that it is based its sensibility and stability in an inductive-capacitive arrangement in parallel and always operate in resonant condition, in such a way that the quality factor of Q arrangement has been very elevated. Thus when the nuclear absorption occurs it is producing a fall of Q effective. The oscillation amplitude is controllable and it maintains in a convenient value over the operation interval using control by feedback. The circuit uses a configuration 'Auto dyne Hop kin' that it suffers as a follower of inductive charge, which have the main characteristic of to cause a negative resistance that it appears through the tuning circuit. It is introduced a control for feedback via two trajectories, the first by differential pair for to maintain the amplitude level in RF and the second for to stability a band wide interval in the modulation condition. It is necessary since the RF signal value must have a value to excite the specimen nucleus without to carry to saturate it and that the permanence in the absorption region was appropriate. Between applications of the nuclear magnetic resonance phenomena we have the magnetic fields measurements, physicochemical molecular properties studies, training and medical instrumentation. (Author)

  13. Nuclear magnetic and electric dipole moments of neon-19

    This thesis presents a detailed discussion of a series of experiments designed to measure the magnetic and electric dipole moments of the β-emitting nucleus 19Ne. The 19Ne is generated in the reaction 19F(p,n)19Ne and is polarized by a ''stern-Gerlach'' magnet in a rare gas atomic beams machine. The atoms are stored in a cell for many seconds without depolarizing. The parity violating asymmetry in the β angular distribution is used to monitor the nuclear polarization. The polarized atoms are stored in a cell in a uniform magnetic field. The β-asymmetry is monitored by a pair of β-detectors located on either side of the cell. Transitions between the M/sub J/ = +1/2 and M/sub J/ = -1/2 spin states are induced by an rf field generated by a small Helmholtz coil pair surrounding the cell. Nuclear magnetic resonance lines are observed and the magnetic moment of 19Ne measured to be μ(19Ne) = -1.88542(8)μ/sub N/. A new magnet, cell and detectors were designed to give narrow resonance lines. The equipment is described in detail and several resonance line shapes are discussed. The narrowest resonance line achieved with this system was 0.043 Hz FWHM. This width is primarily due to the 19Ne lifetime. Pulsed NMR lineshapes were also observed. The narrow NMR lines observed in the previous experiment were then used as a probe to look for an electric dipole moment (EDM) in 19Ne. Any shift in the resonance frequency correlated with changes in an externally applied electric field would be evidence for an EDM. The EDM of the 19Ne atom was measured to (7.2 +/- 6.2 X 10-22 e-cm. This experiment and possible improvements are discussed in detail

  14. Nuclear magnetic resonance study of metallic scandium chlorides

    The 45Sc nuclear magnetic resonance was studied in samples having the general composition CsSc/sub x/Cl3 (0.67 less than or equal to x less than or equal to 1.0) in the CsCl-ScCl3-Sc system. In particular the structure of CsScCl3 suggests that it may be a one-dimensional conductor, and an attempt was therefore made to detect the occurrence of a metal-insulator transition of the type characteristic of one-dimensional conductors. Conventional crossed-coil (nuclear induction) techniques were employed. The 45Sc resonance was studied over a wide frequency range (4 to 24 MHz) at 300K, these measurements yielding the Knight shift and nuclear electric quadrupole coupling parameters. No significant variation in the spectra occurred from 4.2K to 450K, indicating the absence of a metal-insulator transition in this temperature range

  15. Analysis of ringing due to magnetic core materials used in pulsed nuclear magnetic resonance applications

    Prabhu Gaunkar, Neelam; Nlebedim, Cajetan; Hadimani, Ravi; Bulu, Irfan; Song, Yi-Qiao; Mina, Mani; Jiles, David

    Oil-field well logging instruments employ pulsed nuclear magnetic resonance (NMR) techniques and use inductive sensors to detect and evaluate the presence of particular fluids in geological formations. Acting as both signal transmitters and receivers most inductive sensors employ magnetic cores to enhance the quality and amplitude of signals recorded during field measurements. It is observed that the magnetic core also responds to the applied input signal thereby generating a signal (`ringing') that interferes with the measurement of the signals from the target formations. This causes significant noise and receiver dead time and it is beneficial to eliminate/suppress the signals received from the magnetic core. In this work a detailed analysis of the magnetic core response and in particular loading of the sensor due to the presence of the magnetic core is presented. Pulsed NMR measurements over a frequency band of 100 kHz to 1MHz are used to determine the amplitude and linewidth of the signals acquired from different magnetic core materials. A lower signal amplitude and a higher linewidth are vital since these would correspond to minimal contributions from the magnetic core to the inductive sensor response and thus leading to minimized receiver dead time.

  16. Transformation of Symmetrization Order to Nuclear-Spin Magnetization by Chemical Reaction and Nuclear Magnetic Resonance

    Bowers, C. Russell; Weitekamp, Daniel P.

    1986-01-01

    A method of obtaining very large nuclear-spin polarizations is proposed and illustrated by density-operator calculations. The prediction is that chemical reaction and rf irradiation can convert the scalar parahydrogen state into polarization of order unity on the nuclear spins of the products of molecular-hydrogen addition reactions. A means of extending the resultant sensitivity enhancement to other spins is proposed in which the transfer of order occurs through population differences not as...

  17. Proton-detected 3D 1H/13C/1H correlation experiment for structural analysis in rigid solids under ultrafast-MAS above 60 kHz

    Zhang, Rongchun; Nishiyama, Yusuke; Ramamoorthy, Ayyalusamy

    2015-10-01

    A proton-detected 3D 1H/13C/1H chemical shift correlation experiment is proposed for the assignment of chemical shift resonances, identification of 13C-1H connectivities, and proximities of 13C-1H and 1H-1H nuclei under ultrafast magic-angle-spinning (ultrafast-MAS) conditions. Ultrafast-MAS is used to suppress all anisotropic interactions including 1H-1H dipolar couplings, while the finite-pulse radio frequency driven dipolar recoupling (fp-RFDR) pulse sequence is used to recouple dipolar couplings among protons and the insensitive nuclei enhanced by polarization transfer technique is used to transfer magnetization between heteronuclear spins. The 3D experiment eliminates signals from non-carbon-bonded protons and non-proton-bonded carbons to enhance spectral resolution. The 2D (F1/F3) 1H/1H and 2D 13C/1H (F2/F3) chemical shift correlation spectra extracted from the 3D spectrum enable the identification of 1H-1H proximity and 13C-1H connectivity. In addition, the 2D (F1/F2) 1H/13C chemical shift correlation spectrum, incorporated with proton magnetization exchange via the fp-RFDR recoupling of 1H-1H dipolar couplings, enables the measurement of proximities between 13C and even the remote non-carbon-bonded protons. The 3D experiment also gives three-spin proximities of 1H-1H-13C chains. Experimental results obtained from powder samples of L-alanine and L-histidine ṡ H2O ṡ HCl demonstrate the efficiency of the 3D experiment.

  18. Characterisation of black carbon-rich samples by (13)C solid-state nuclear magnetic resonance.

    Novotny, Etelvino H; Hayes, Michael H B; Deazevedo, Eduardo R; Bonagamba, Tito J

    2006-09-01

    There are difficulties in quantifying and characterising the organic matter (OM) in soils that contain significant amounts of partially oxidised char or charcoal materials. The anthropogenic black carbon (BC), such as that found in the Terra Preta de Indio soils of the Amazon region, is a good example of the OM that is difficult to analyse in such soils. (13)C direct polarisation/magic angle spinning (DP/MAS) at high MAS frequency, (1)H-(13)C cross polarisation (CP)/MAS with total suppression of spinning sidebands (TOSS), and chemical shift anisotropy (CSA) filter nuclear magnetic resonance techniques have been applied successfully for quantifying the different components of OM. However, because pyrogenic materials present strong local magnetic susceptibility heterogeneities, the use of CSA-filter and TOSS make the pulse sequences very sensitive to imperfections in the pi pulses. In this study, the DP/MAS pulse sequence was replaced by a CP with a radio frequency ramp--variable amplitude CP (VACP)--VACP/MAS pulse sequence, and composite pi pulses were used in the CSA-filter and TOSS pulse sequences. In that way, the component functionalities in a humic acid from a BC soil were successfully determined. The spectrometer time needed was greatly decreased by employing this VACP/MAS technique. This development provides an accurate method for characterising BC-rich samples from different origins. PMID:16688435

  19. Characterisation of black carbon-rich samples by 13C solid-state nuclear magnetic resonance

    Novotny, Etelvino H.; Hayes, Michael H. B.; Deazevedo, Eduardo R.; Bonagamba, Tito J.

    2006-09-01

    There are difficulties in quantifying and characterising the organic matter (OM) in soils that contain significant amounts of partially oxidised char or charcoal materials. The anthropogenic black carbon (BC), such as that found in the Terra Preta de Índio soils of the Amazon region, is a good example of the OM that is difficult to analyse in such soils. 13C direct polarisation/magic angle spinning (DP/MAS) at high MAS frequency, 1H-13C cross polarisation (CP)/MAS with total suppression of spinning sidebands (TOSS), and chemical shift anisotropy (CSA) filter nuclear magnetic resonance techniques have been applied successfully for quantifying the different components of OM. However, because pyrogenic materials present strong local magnetic susceptibility heterogeneities, the use of CSA-filter and TOSS make the pulse sequences very sensitive to imperfections in the π pulses. In this study, the DP/MAS pulse sequence was replaced by a CP with a radio frequency ramp—variable amplitude CP (VACP)—VACP/MAS pulse sequence, and composite π pulses were used in the CSA-filter and TOSS pulse sequences. In that way, the component functionalities in a humic acid from a BC soil were successfully determined. The spectrometer time needed was greatly decreased by employing this VACP/MAS technique. This development provides an accurate method for characterising BC-rich samples from different origins.

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

    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 T2 relaxation time at 0.5 T (≈21.7 MHz). In case of a specific binding the particles cluster and the T2 relaxation time of the sample changes. The detection limit in buffer for FITC-avidin was determined to be 1.35 nM and 107 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

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

    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.

  2. Rotating-frame gradient fields for magnetic resonance imaging and nuclear magnetic resonance in low fields

    Bouchard, Louis-Serge; Pines, Alexander; Demas, Vasiliki

    2014-01-21

    A system and method for Fourier encoding a nuclear magnetic resonance (NMR) signal is disclosed. A static magnetic field B.sub.0 is provided along a first direction. An NMR signal from the sample is Fourier encoded by applying a rotating-frame gradient field B.sub.G superimposed on the B.sub.0, where the B.sub.G comprises a vector component rotating in a plane perpendicular to the first direction at an angular frequency .omega.in a laboratory frame. The Fourier-encoded NMR signal is detected.

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

    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.

  4. 1H MAS NMR spectra of hy- droxyl species on diatomite surface

    2001-01-01

    High spinning speed 1H magic-angle spinning nuclear magnetic resonance (1H MAS NMR) was used to detect surface hydroxyl groups of diatomite, which include isolated hydroxyl groups and hydrogen-bonded hydroxyl groups, and water adsorbed on diatomite surface that include pore water and hydrogen-bonded water. The corresponding proton chemical shifts of above species are ca. 2.0, 6.0-7.1, 4.9 and 3.0 respectively. Accompanied by thermal treatment temperature ascending, the pore water and hydrogen-bonded water are desorbed successively. As a result, the relative intensities of the peaks assigned to protons of isolat-ed hydroxyl groups and hydrogen-bonded hydroxyl groups increase gradually and reach their maxima at 1000℃. After 1100℃ calcination, the hydroxyl groups that classified to strongly hydrogen-bonded ones and the isolated hydroxyl groups condense basically. But some weakly hydrogen-bonded hydroxyl groups may still persist in the micropores.

  5. Discrimination of sugarcane according to cultivar by 1H NMR and chemometric analyses

    Alves Filho, Elenilson G.; Silva, Lorena M.A.; Choze, Rafael; Liao, Luciano M. [Laboratorio de Ressonancia Magnetica Nuclear, Instituto de Quimica, Universidade Federal de Goias (UFG), Goiania, GO (Brazil); Honda, Neli K.; Alcantara, Glaucia B. [Departamento de Quimica, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil)

    2012-07-01

    Several technologies for the development of new sugarcane cultivars have mainly focused on the increase in productivity and greater disease resistance. Sugarcane cultivars are usually identified by the organography of the leaves and stems, the analysis of peroxidase and esterase isoenzyme activities and the total soluble protein as well as soluble solid content. Nuclear magnetic resonance (NMR) associated with chemometric analysis has proven to be a valuable tool for cultivar assessment. Thus, this article describes the potential of chemometric analysis applied to 1H high resolution magic angle spinning (HRMAS) and NMR in solution for the investigation of sugarcane cultivars. For this purpose, leaves from eight different cultivars of sugarcane were investigated by {sup 1}H NMR spectroscopy in combination with chemometric analysis. The approach shows to be a useful tool for the distinction and classification of different sugarcane cultivars as well as to access the differences on its chemical composition. (author)

  6. Direct detection of solanesol in tobacco by 1H and 13C magic angle spinning NMR

    1H and 13C NMR have been used to detect solanesol directly in tobacco without destroying or modifying the sample. Magic angle sample spinning was employed to remove the resonance line broadening due to variations of magnetic susceptibility within the sample. 13C line widths of ca . 10 Hz were obtained. The 1H MAS spectrum of tobacco allows the solanesol signals to be resolved from the broad signal of exchangeable protons. 13C spin-lattice relaxation times (T3) and nuclear Overhauser enhancements (NOE) of solanesol in chloroform solution, in intact tobacco, and as nest oil indicate that the polyisoprene chain motion in tobacco is restricted relative to the motion in solution but still sufficient to average out the dipolar couplings between protons and carbons. (author)

  7. Nuclear spin relaxation in systems of magnetic spheres

    A new approach to the NMR relaxation theory for a system of magnetic spheres (sufficiently big spherical molecules) is presented. In this paper the NMR spin-lattice relaxation time T1 and spin-spin relaxation time T2 are calculated for nuclear spins I→j, taking into account intermolecular dipole-dipole interactions between the spins I→j, and spins S→k in the magnetic spheres. By an expansion of the dipole-dipole interaction in a series of spherical harmonics, it is possible to separate spatial variables of the interacting spins in a laboratory frame. A simultaneous effect of isotropic rotational and translation diffusion of the spins and relaxation rate of spins S→k is also taken into account

  8. Nuclear magnetic resonance force microscopy with a microwire rf source

    The authors use a 1.0 μm wide patterned Cu wire with an integrated nanomagnetic tip to measure the statistical nuclear polarization of 19F in CaF2 by magnetic resonance force microscopy. With less than 350 μW of dissipated power, the authors achieve rf magnetic fields over 4 mT at 115 MHz for a sample positioned within 100 nm of the 'microwire' rf source. A 200 nm diameter FeCo tip integrated onto the wire produces field gradients greater than 105 T/m at the same position. The large rf fields from the broadband microwire enable long rotating-frame spin lifetimes of up to 15 s at 4 K

  9. Nuclear Magnetic Resonance with the Distant Dipolar Field

    Corum, C A

    2005-01-01

    Distant dipolar field (DDF)-based nuclear magnetic resonance is an active research area with many fundamental properties still not well understood. Already several intriguing applications have developed, like HOMOGENIZED and IDEAL spectroscopy, that allow high resolution spectra to be obtained in inhomogeneous fields, such as in-vivo. The theoretical and experimental research in this thesis concentrates on the fundamental signal properties of DDF-based sequences in the presence of relaxation (T1 and T2) and diffusion. A general introduction to magnetic resonance phenomenon is followed by a more in depth introduction to the DDF and its effects. A novel analytical signal equation has been developed to describe the effects of T2 relaxation and diffusing spatially modulated longitudinal spins during the signal build period of an HOMOGENIZED cross peak. Diffusion of the longitudinal spins results in a lengthening of the effective dipolar demagnetization time, delaying the re-phasing of coupled anti-phase states in...

  10. 2.3 Tomography using nuclear magnetic resonance

    The use of nuclear magnetic resonance (NMR) not only allows the tomographic imaging of tissues but also the identification of the biochemical structure of tissues. The principles of the method are described as is a NMR examination unit based on a giant magnet with a central opening in which is placed the patient. The application of the said method allows to distinguish in the skull structures 2 mm in size, in the trunk 3 mm in size. The morphological image may be obtained in 2 mins, data on chemical composition in 7 mins. The method may be applied for diagnosing edemas of the brain, hematomas, for distinguishing benign and malignant tumours, for measuring blood vessel flow and for monitoring biochemical processes. The advantage of the method is that it does not load the patient with radioactive radiation. (J.P.)

  11. A personal computer-based nuclear magnetic resonance spectrometer

    Job, Constantin; Pearson, Robert M.; Brown, Michael F.

    1994-11-01

    Nuclear magnetic resonance (NMR) spectroscopy using personal computer-based hardware has the potential of enabling the application of NMR methods to fields where conventional state of the art equipment is either impractical or too costly. With such a strategy for data acquisition and processing, disciplines including civil engineering, agriculture, geology, archaeology, and others have the possibility of utilizing magnetic resonance techniques within the laboratory or conducting applications directly in the field. Another aspect is the possibility of utilizing existing NMR magnets which may be in good condition but unused because of outdated or nonrepairable electronics. Moreover, NMR applications based on personal computer technology may open up teaching possibilities at the college or even secondary school level. The goal of developing such a personal computer (PC)-based NMR standard is facilitated by existing technologies including logic cell arrays, direct digital frequency synthesis, use of PC-based electrical engineering software tools to fabricate electronic circuits, and the use of permanent magnets based on neodymium-iron-boron alloy. Utilizing such an approach, we have been able to place essentially an entire NMR spectrometer console on two printed circuit boards, with the exception of the receiver and radio frequency power amplifier. Future upgrades to include the deuterium lock and the decoupler unit are readily envisioned. The continued development of such PC-based NMR spectrometers is expected to benefit from the fast growing, practical, and low cost personal computer market.

  12. On the quantumness of correlations in nuclear magnetic resonance

    Soares-Pinto, D O; Maziero, J; Gavini-Viana, A; Serra, R M; Céleri, L C

    2012-01-01

    Nuclear Magnetic Resonance (NMR) was successfully employed to test several protocols and ideas in Quantum Information Science. In most of these implementations the existence of entanglement was ruled out. This fact introduced concerns and questions about the quantum nature of such bench tests. In this article we address some issues related to the non-classical aspects of NMR systems. We discuss some experiments where the quantum aspects of this system are supported by quantum correlations of separable states. Such quantumness, beyond the entanglement-separability paradigm, is revealed via a departure between the quantum and the classical versions of information theory. In this scenario, the concept of quantum discord seems to play an important role. We also present an experimental implementation of an analogous of the single-photon Mach-Zehnder interferometer employing two nuclear spins to encode the interferometric paths. This experiment illustrate how non-classical correlations of separable states may be us...

  13. Applications of nuclear magnetic resonance spectroscopy to certifiable food colors

    Nuclear magnetic resonance spectroscopy was found suitable for the identification of individual colours, for distinguishing individual colours from colour mixtures, for the identification and semi-quantitative determination of the individual colours in mixtures and for proofs of the adulteration of certified colours adding noncertified colours. The method is well suited for observing the purity of colours and may also be used as the control method in the manufacture of colours and in assessing their stability and their resistance to increased temperature and light. (M.K.)

  14. Nuclear magnetic resonance imaging of the posterior fossa disorders

    Ikeda, Toshiaki; Fukaya, Takashi; Nomura, Yasuya; Yoshikawa, Kouki

    1985-03-01

    Nuclear magnetic resonance scans (NMR-CT) were performed on patients with posterior fossa disorders such as acoustic neurinoma, cerebellar tumour (gangliocytoma), epidermoid tumour and spinocerebellar degeneration, and compared with X-ray computed tomography (CT) scans. The advantages of NMR-CT include lack of bone artifact, variety of image planes, transverse, sagital and coronal imaging, and high ability to differentiate tissues. The disadvantages include prolonged data accumulation time, lack of bone detail and calcification, limited spatial resolution and suitability of patients. (author).

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

    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

  16. Experimental Implementation of Remote State Preparation by Nuclear Magnetic Resonance

    Peng, X; Fang, X; Feng, M; Liu, M; Gao, K; Peng, Xinhua; Zhu, Xiwen; Fang, Ximing; Feng, Mang; Liu, Maili; Gao, Kelin

    2003-01-01

    We have experimentally implemented remote state preparation (RSP) of a qubit from a hydrogen to a carbon nucleus in molecules of carbon-13 labeled chloroform $^{13}$CHCl$_{3}$ over interatomic distances using liquid-state nuclear magnetic resonance (NMR) technique. Full RSP of a special ensemble of qubits, i.e., a qubit chosen from equatorial and polar great circles on a Bloch sphere with Pati's scheme, was achieved with one cbit communication. Such a RSP scheme can be generalized to prepare a large number of qubit states and may be used in other quantum information processing and quantum computing.

  17. Neutron studies of nuclear magnetism at ultralow temperature

    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...... phase diagram in applied fields. The low-and the high-field structures are of type I, while in intermediate fields the unconventional ordering vector q = 2 pi(1,1/3,1/3) is observed. Strong hysteresis effects indicate first-order phase boundaries in copper. (C) 1998 Elsevier Science B.V. All rights...

  18. Implementation of Quantum Private Queries Using Nuclear Magnetic Resonance

    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.

  19. Implementation of Quantum Private Queries Using Nuclear Magnetic Resonance

    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. (general)

  20. Proton-detected 3D 14N/14N/1H isotropic shift correlation experiment mediated through 1H-1H RFDR mixing on a natural abundant sample under ultrafast MAS

    Pandey, Manoj Kumar; Nishiyama, Yusuke

    2015-09-01

    In this contribution, we have demonstrated a proton detection-based approach on a natural abundant powdered L-Histidine HCl-H2O sample at ultrafast magic angle spinning (MAS) to accomplish 14N/14N correlation from a 3D 14N/14N/1H isotropic shift correlation experiment mediated through 1H finite-pulse radio frequency-driven recoupling (fp-RFDR). Herein the heteronuclear magnetization transfer between 14N and 1H has been achieved by HMQC experiment, whereas 14N/14N correlation is attained through enhanced 1H-1H spin diffusion process due to 1H-1H dipolar recoupling during the RFDR mixing. While the use of ultrafast MAS (90 kHz) provides sensitivity enhancement through increased 1H transverse relaxation time (T2), the use of micro-coil probe which can withstand strong 14N radio frequency (RF) fields further improves the sensitivity per unit sample volume.

  1. Development of Metallic Magnetic Calorimeters for Nuclear Safeguards Applications

    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

  2. Enhanced nuclear magnetic resonance in a non-magnetic cubic doublet

    In this thesis two lanthanide compounds are studied which show enhanced nuclear magnetism at low temperatures: Rb2NaHoF6 and CsNaHoF6. Chapter II gives a description of the 4He-circulating refrigerator, which was built to provide the low temperatures required for the polarization of the enhanced nuclear moments. This type of dilution refrigerator was chosen because of its simple design and large cooling power. Chapter III is devoted to a comparison of the different types of dilution refrigerators. A theoretical discussion is given of their performance, starting from the differential equations, which govern the temperature distribution in the refrigerator. In chapter IV the actual performance of the refrigerator, described in chapter II is discussed. In chapter V a description of the NMR-apparatus, developed for very-low-temperature NMR experiments is given. In chapter VI experimental results on the compound Rb2NaHoF6 are presented. The CEF-ground state of this compound is probably the non-magnetic doublet GAMMA3, but at a temperature of 170 K a structural phase transition lowers the crystal symmetry from cubic to tetragonal and the doublet is split into two singlets. In chapter VII specific heat, (enhanced) nuclear magnetic resonance and magnetization measurements on the compound Cs2NaHoF6 are presented which also has a GAMMA3-doublet ground state. In zero magnetic field the degeneracy of the doublet is removed at a temperature of 393 mK, where a phase transition is induced by quadrupolar interactions. (Auth.)

  3. Measurement of magnetic field strengths in the Mirror Fusion Test Facility using nuclear magnetic resonance techniques

    The production of the proper magnetic field profile is fundamental to plasma confinement in magnetic mirror systems. The knowledge of this profile is important for the control of a variety of physical processes which affect particle confinement, including thermal barrier and potential well formation. A system of probes using the nuclear magnetic resonance of protons in magnetic fields is used to measure the field strengths at various points in the Mirror Fusion Test Facility (MFTF-B). The system operates at high fields (1-12 T) with significant nonuniformity (≤ 1.5 T/m) by taking advantage of the phenomenon of spin echo. In addition, the probes can operate in the MFTF-B environment where low temperature capability and remote operation is necessary. These probes have been tested with laboratory magnets to develop an engineering model which relates probe signal-to-noise (S/N) ratio to probe parameters and magnetic field strengths and gradients. Engineering design formula and techniques are presented as well as data from laboratory test stands

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

    Rezaei, Z

    2016-01-01

    Different saturation properties of cold symmetric nuclear matter in the strong magnetic field have been considered. We have seen that for magnetic fields about $B> 3 \\times 10 ^ {17}\\ G$, {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 $B 3 \\times 10 ^ {17}\\ G$, {the softening of 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 applying the experimental observable.

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

    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.

  6. Translational diffusion in paramagnetic liquids by 1H NMR relaxometry: Nitroxide radicals in solution

    Kruk, D.; Korpała, A.; Kubica, A.; Meier, R.; Rössler, E. A.; Moscicki, J.

    2013-01-01

    For nitroxide radicals in solution one can identify three frequency regimes in which 1H spin-lattice relaxation rate of solvent molecules depend linearly on square root of the 1H resonance frequency. Combining a recently developed theory of nuclear (proton) spin-lattice relaxation in solutions of nitroxide radicals [D. Kruk et al., J. Chem. Phys. 137, 044512 (2012)], 10.1063/1.4736854 with properties of the spectral density function associated with translational dynamics, relationships between the corresponding linear changes of the relaxation rate (for 14N spin probes) and relative translational diffusion coefficient of the solvent and solute molecules have been derived (in analogy to 15N spin probes [E. Belorizky et al., J. Phys. Chem. A 102, 3674 (1998)], 10.1021/jp980397h). This method allows a simple and straightforward determination of diffusion coefficients in spin-labeled systems, by means of 1H nuclear magnetic resonance (NMR) relaxometry. The approach has thoroughly been tested by applying to a large set of experimental data—1H spin-lattice relaxation dispersion results for solutions of different viscosity (decalin, glycerol, propylene glycol) of 14N and 15N spin probes. The experiments have been performed versus temperature (to cover a broad range of translational diffusion coefficients) using field cycling spectrometer which covers three decades in 1H resonance frequency, 10 kHz-20 MHz. The limitations of NMR relaxometry caused by the time scale of the translational dynamics as well as electron spin relaxation have been discussed. It has been shown that for spin-labeled systems NMR relaxometry gives access to considerably faster diffusion processes than for diamagnetic systems.

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

    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.

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

    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...

  9. 1H NMR determination of urinary betaine in patients with premature vascular disease and mild homocysteinemia.

    Lundberg, P; Dudman, N P; Kuchel, P W; Wilcken, D E

    1995-02-01

    Urinary N,N,N-trimethylglycine (betaine) and N,N-dimethylglycine (DMG) have been identified and quantified for clinical purposes by proton nuclear magnetic resonance (1H NMR) measurement in previous studies. We have assessed these procedures by using both one-dimensional (1-D) and 2-D NMR spectroscopy, together with pH titration of urinary extracts to help assign 1H NMR spectral peaks. The betaine calibration curve linearity was excellent (r = 0.997, P = 0.0001) over the concentration range 0.2-1.2 mmol/L, and CVs for replicate betaine analyses ranged from 7% (n = 10) at the lowest concentration to 1% (n = 9) at the highest. The detection limit for betaine was < 15 mumol/L. Urinary DMG concentrations were substantially lower than those of betaine. Urinary betaine and DMG concentrations measured by 1H NMR spectroscopy from 13 patients with premature vascular disease and 17 normal controls provided clinically pertinent data. We conclude that 1H NMR provides unique advantages as a research tool for determination of urinary betaine and DMG concentrations. PMID:7533065

  10. Molecular water motions of skim milk powder solutions during acidification studied by 17O and 1H nuclear magnetic resonance and rheology

    Møller, S M; Whittaker, A. K.; Stokes, J. R.;

    2011-01-01

    The molecular motion of water was studied in glucono-δ-lactone-acidified skim milk powder (SMP) solutions with various pH values and dry matter contents. NMR relaxometry measurements revealed that lowering the pH in SMP solutions affected 17O and 1HT2 relaxation rates almost identically...

  11. Metabonomic Response to Milk Proteins after a Single Bout of Heavy Resistance Exercise Elucidated by 1H Nuclear Magnetic Resonance Spectroscopy.

    Yde, Christian Clement; Ditlev, Ditte Bruun; Reitelseder, Søren; Bertram, Hanne Christine

    2013-01-01

    In the present study, proton NMR-based metabonomics was applied on femoral arterial plasma samples collected from young male subjects (milk protein n = 12 in a crossover design; non-caloric control n = 8) at different time intervals (70, 220, 370 min) after heavy resistance training and intake of either a whey or calcium caseinate protein drink in order to elucidate the impact of the protein source on post-exercise metabolism, which is important for muscle hypertrophy. Dynamic changes in the post-exercise plasma metabolite profile consisted of fluctuations in alanine, beta-hydroxybutyrate, branched amino acids, creatine, glucose, glutamine, glutamate, histidine, lipids and tyrosine. In comparison with the intake of a non-caloric drink, the same pattern of changes in low-molecular weight plasma metabolites was found for both whey and caseinate intake. However, the study indicated that whey and caseinate protein intake had a different impact on low-density and very-low-density lipoproteins present in the blood, which may be ascribed to different effects of the two protein sources on the mobilization of lipid resources during energy deficiency. In conclusion, no difference in the effects on low-molecular weight metabolites as measured by proton NMR-based metabonomics was found between the two protein sources. PMID:24957889

  12. Metabonomic Response to Milk Proteins after a Single Bout of Heavy Resistance Exercise Elucidated by 1H Nuclear Magnetic Resonance Spectroscopy

    Hanne Christine Bertram

    2013-01-01

    Full Text Available In the present study, proton NMR-based metabonomics was applied on femoral arterial plasma samples collected from young male subjects (milk protein n = 12 in a crossover design; non-caloric control n = 8 at different time intervals (70, 220, 370 min after heavy resistance training and intake of either a whey or calcium caseinate protein drink in order to elucidate the impact of the protein source on post-exercise metabolism, which is important for muscle hypertrophy. Dynamic changes in the post-exercise plasma metabolite profile consisted of fluctuations in alanine, beta-hydroxybutyrate, branched amino acids, creatine, glucose, glutamine, glutamate, histidine, lipids and tyrosine. In comparison with the intake of a non-caloric drink, the same pattern of changes in low-molecular weight plasma metabolites was found for both whey and caseinate intake. However, the study indicated that whey and caseinate protein intake had a different impact on low-density and very-low-density lipoproteins present in the blood, which may be ascribed to different effects of the two protein sources on the mobilization of lipid resources during energy deficiency. In conclusion, no difference in the effects on low-molecular weight metabolites as measured by proton NMR-based metabonomics was found between the two protein sources.

  13. Characterization of polymers by nuclear magnetic resonance (NMR)

    After having recalled some generalities which are necessary for the obtention of a spectrum and the method to be chosen, the author considers the use of the hydrogen 1 and carbon 13 high resolution nuclear magnetic resonance (in liquid and solid phase) on some examples in the field of polymers. In the case of the polymers in solution, this technology seems to be limited to liquid or soluble polymers and to insoluble polymers which are inflatable in some solvents. The other polymers (infusible and non-inflatable) require the use of the CP-MAS solid phase NMR (cross polarization magic angle spinning nuclear magnetic resonance). For liquids, the NMR allows to better know the microstructure of these compounds and to better understand the reaction mechanisms (in the case of poly-condensation, polymerization, degradation..) which can control the polymerization. The CP-MAS solid phase NMR is a particularly interesting method for the determination of insoluble three-dimensional polymers structures and for the study of the conformations and configurations of the chain carbonated skeleton. (O.M.). 46 refs., 18 figs

  14. Nuclear magnetic relaxation of liquids in porous media

    Nuclear magnetic relaxation is useful for probing physical and chemical properties of liquids in porous media. Examples are given on high surface area porous materials including calibrated porous silica glasses, granular packings, plaster pastes, cement-based materials and natural porous materials, such as sandstone and carbonate rocks. Here, we outline our recent NMR relaxation work for these very different porous materials. For instance, low field NMR relaxation of water in calibrated granular packings leads to striking different pore-size dependencies of the relaxation times T1 and T2 when changing the amount of surface paramagnetic impurities. This allows separation of the diffusion and surface limited regimes of relaxation in these macroporous media. The magnetic field dependence of the nuclear spin-lattice relaxation rate 1/T1(ω0) is also a rich source of dynamical information for characterizing the molecular dynamics of liquids in porous media. This allows a continuous characterization of the evolving microstructure of various cementitious materials. Our recent applications of two-dimensional (2D) T1-T2 and T2-z-store-T2 correlation experiments have evidenced the water exchange in connected micropores of cement pastes. The direct probing of water adsorption time on a solid surface gives access to an original characterization of the surface nano-wettability of porous plaster pastes. We show that such a parameter depends directly on the physical chemistry of the pore surfaces. Lastly, we outline our recent measurements of wettability in oil/brine/reservoir carbonate rocks.

  15. Inlfuence of Hemolysis on Analytic Results of Nuclear Magnetic Resonance-based Metabonomics

    LIU Qiao

    2015-01-01

    Objective:To explore the changes of small molecular metabolites and their content in plasma samples due to hemolysis so as to analyze the influence of hemolysis of plasma samples on metabonomic study. Methods: Healthy adult males undergoing physical examination without drug administration history in recent period were selected to collect 10 hemolytic plasma samples and 10 hemolysis-free samples from them. Spectrograms of hydrogen nuclear magnetic resonance (1H-NMR) were collected and Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence was used to inhibit the production of broad peak by protein and lipid, and SIMCA-P+12.0 software was applied to conduct mode recognition and Pearson correlation analysis. Results: CPMG-1H NMR plasma metabolism spectrums showed that compared with hemolysis-free samples, hemolytic samples were evidently higher in the contents of acetate, acetone and pyruvic acid, but markedly lower in that of glucose. In addition, the chemical shift of glycine-CH2 in hemolysis group moved to the lower ifeld. Orthogonal partial least-square discriminant analysis (OPLS-DA) was further applied to initiate mode recognition analysis and the results demonstrated that hemolysis group was prominently higher in the contents of metabolites, such as leucine, valine, lysine, acetate, proline, acetone, pyruvic acid, creatine, creatinine, glycine, glycerol, serine and lactic acid, but obviously lower in the contents of isoleucine and glucose than hemolysis-free group. Pearson correlation analysis indicated that in hemolytic samples, the contents of eucine, valine, lysine, proline, N-acetyl-glycoprotein, creatine, creatinine, glycerol and serine were higher but that of isoleucine was lower. Conclusion: Hemolysis can lead to the changes of multiple metabolite content and inlfuence the analytic results of metabonomics, so in practical operation, hemolytic samples should be excluded from the study.

  16. Nuclear magnetic resonance-based metabolomics for prediction of gastric damage induced by indomethacin in rats

    Highlights: ► NMR based metabolomics – gastric damage by indomethacin. ► Pattern recognition analysis was performed to biomarkers of gastric damage. ► 2-Oxoglutarate, acetate, taurine and hippurate were selected as putative biomarkers. ► The gastric damage induced by NSAIDs can be screened in the preclinical step of drug. - Abstract: Non-steroidal anti-inflammatory drugs (NSAIDs) have side effects including gastric erosions, ulceration and bleeding. In this study, pattern recognition analysis of the 1H-nuclear magnetic resonance (NMR) spectra of urine was performed to develop surrogate biomarkers related to the gastrointestinal (GI) damage induced by indomethacin in rats. Urine was collected for 5 h after oral administration of indomethacin (25 mg kg−1) or co-administration with cimetidine (100 mg kg−1), which protects against GI damage. The 1H-NMR urine spectra were divided into spectral bins (0.04 ppm) for global profiling, and 36 endogenous metabolites were assigned for targeted profiling. The level of gastric damage in each animal was also determined. Indomethacin caused severe gastric damage; however, indomethacin administered with cimetidine did not. Simultaneously, the patterns of changes in their endogenous metabolites were different. Multivariate data analyses were carried out to recognize the spectral pattern of endogenous metabolites related to indomethacin using partial least square-discrimination analysis. In targeted profiling, a few endogenous metabolites, 2-oxoglutarate, acetate, taurine and hippurate, were selected as putative biomarkers for the gastric damage induced by indomethacin. These metabolites changed depending on the degree of GI damage, although the same dose of indomethacin (10 mg kg−1) was administered to rats. The results of global and targeted profiling suggest that the gastric damage induced by NSAIDs can be screened in the preclinical stage of drug development using a NMR based metabolomics approach.

  17. Nuclear magnetic resonance-based metabolomics for prediction of gastric damage induced by indomethacin in rats

    Um, So Young [Department of Pharmacology, National Institute of Toxicological Research, Korea Food and Drug Administration, 643 Yeonje-ri, Gangoe-myeon, Cheongwon-gun, Chungbuk (Korea, Republic of); Division of Life and Pharmaceutical Science and College of Pharmacy, Ewha Womans University, 52 Ewahyeodae-gil, Seodaemun-gu, Seoul (Korea, Republic of); Park, Jung Hyun [Division of Life and Pharmaceutical Science and College of Pharmacy, Ewha Womans University, 52 Ewahyeodae-gil, Seodaemun-gu, Seoul (Korea, Republic of); Chung, Myeon Woo [Department of Pharmacology, National Institute of Toxicological Research, Korea Food and Drug Administration, 643 Yeonje-ri, Gangoe-myeon, Cheongwon-gun, Chungbuk (Korea, Republic of); Kim, Kyu-Bong [College of Pharmacy, Dankook University, Dandae-ro, Cheonan, Chungnam (Korea, Republic of); Kim, Seon Hwa [Department of Pharmacology, National Institute of Toxicological Research, Korea Food and Drug Administration, 643 Yeonje-ri, Gangoe-myeon, Cheongwon-gun, Chungbuk (Korea, Republic of); Division of Life and Pharmaceutical Science and College of Pharmacy, Ewha Womans University, 52 Ewahyeodae-gil, Seodaemun-gu, Seoul (Korea, Republic of); College of Pharmacy, Dankook University, Dandae-ro, Cheonan, Chungnam (Korea, Republic of); Choi, Ki Hwan, E-mail: hyokwa11@korea.kr [Department of Pharmacology, National Institute of Toxicological Research, Korea Food and Drug Administration, 643 Yeonje-ri, Gangoe-myeon, Cheongwon-gun, Chungbuk (Korea, Republic of); Lee, Hwa Jeong, E-mail: hwalee@ewha.ac.kr [Division of Life and Pharmaceutical Science and College of Pharmacy, Ewha Womans University, 52 Ewahyeodae-gil, Seodaemun-gu, Seoul (Korea, Republic of)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer NMR based metabolomics - gastric damage by indomethacin. Black-Right-Pointing-Pointer Pattern recognition analysis was performed to biomarkers of gastric damage. Black-Right-Pointing-Pointer 2-Oxoglutarate, acetate, taurine and hippurate were selected as putative biomarkers. Black-Right-Pointing-Pointer The gastric damage induced by NSAIDs can be screened in the preclinical step of drug. - Abstract: Non-steroidal anti-inflammatory drugs (NSAIDs) have side effects including gastric erosions, ulceration and bleeding. In this study, pattern recognition analysis of the {sup 1}H-nuclear magnetic resonance (NMR) spectra of urine was performed to develop surrogate biomarkers related to the gastrointestinal (GI) damage induced by indomethacin in rats. Urine was collected for 5 h after oral administration of indomethacin (25 mg kg{sup -1}) or co-administration with cimetidine (100 mg kg{sup -1}), which protects against GI damage. The {sup 1}H-NMR urine spectra were divided into spectral bins (0.04 ppm) for global profiling, and 36 endogenous metabolites were assigned for targeted profiling. The level of gastric damage in each animal was also determined. Indomethacin caused severe gastric damage; however, indomethacin administered with cimetidine did not. Simultaneously, the patterns of changes in their endogenous metabolites were different. Multivariate data analyses were carried out to recognize the spectral pattern of endogenous metabolites related to indomethacin using partial least square-discrimination analysis. In targeted profiling, a few endogenous metabolites, 2-oxoglutarate, acetate, taurine and hippurate, were selected as putative biomarkers for the gastric damage induced by indomethacin. These metabolites changed depending on the degree of GI damage, although the same dose of indomethacin (10 mg kg{sup -1}) was administered to rats. The results of global and targeted profiling suggest that the gastric damage induced by

  18. Fatty acids profile of Sacha Inchi oil and blends by 1H NMR and GC-FID.

    Vicente, Juarez; de Carvalho, Mario Geraldo; Garcia-Rojas, Edwin E

    2015-08-15

    This study aimed at the characterization of blends of Sacha Inchi oil (SIO) with different ratios of SO (soybean oil) and CO (corn oil) by nuclear magnetic resonance ((1)H NMR), compared with the data obtained by gas chromatography with a flame ionization detector (GC-FID). The (1)H NMR and GC-FID data from different ratios of SIO were adjusted by a second order polynomial equation. The two techniques were highly correlated (R(2) values ranged from 0.995 to 0.999), revealing that (1)H NMR is an efficient methodology for the quantification of omega-3 fatty acids in oils rich in omega-6 fatty acids or vice versa such as SO and CO and, on the other hand, can be used to quantify ω-6 in oils rich in ω-3, such as SIO. PMID:25794742

  19. Ehrlich and sarcoma 180 tumour characterisation and early detection by {sup 1}H NMR-based metabonomics of mice serum

    Grandizoli, Caroline W.P. da S.; Simonelli, Fabio; Nagata, Noemi; Barison, Andersson, E-mail: andernmr@ufpr.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica; Carrenho, Luise Z.B.; Francisco, Thais M.G. de; Campos, Francinete R. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Farmacia; Santana Filho, Arquimedes P. de; Sassaki, Guilherme L. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Bioquimica; Kreuger, Maria R.O. [Universidade do Vale do Itajai (UNIVALI), (Brazil). Centro de Ciencias da Saude

    2014-05-15

    The success of cancer treatment is directly related to early detection before symptoms emerge, although nowadays few cancers can be detected early. In this sense, {sup 1}H nuclear magnetic resonance ({sup 1}H NMR)-based metabonomics was used to identify metabolic changes in biofluid as a consequence of tumours growing in mice. Through partial least squares discriminant analysis (PLS-DA) analysis of {sup 1}H NMR spectra from serum samples it was possible to diagnose Ehrlich ascites and Sarcoma 180 tumours five and ten days after cell inoculation, respectively. Lipids, lipoproteins and lactate were the main biomarkers at onset as well as in the progress of carcinogenic process. Thus, NMR-based metabonomics can be a valuable tool to study the effects of tumour establishment on the chemical composition of biofluids. (author)

  20. The use of Nuclear Magnetic Resonance to characterize and evaluate rubber degradation

    Somers, A. E.; Bastow, T. J.; Burgar, M. I.; Forsyth, M.; Hill, A. J.

    1999-12-01

    Nuclear Magnetic Resonance (NMR) is a characterization technique in which the (non-zero spin) nuclei of the constituent elements in the material can be excited to resonance in an applied magnetic field around a frequency specific to each NMR active nucleus. The power of this technique stems from its ability to distinguish between like atoms in magnetically/chemically unique environments. For 1H NMR in natural and synthetic rubbers designed for industrial use, the transverse (or spin-spin) relaxation time, T2, of the resonance can be used to determine the degree of sulfur (or other) cross-linking between the polymer chains. In this work, NMR is used to monitor the degradation of natural rubber due to oxidation and/or ozonolysis. This degradation causes bond cleavage and increases the cross-link density within the material. These processes lead to a rubber becoming brittle, to the point where it can no longer withstand the operating conditions. These structural/chemical changes in a degraded rubber liner used in service are characterized by 13C NMR spectroscopy. Although the work here is laboratory based and has been performed on relatively sophisticated NMR equipment, another less accurate, but potentially more useful NMR method is also being investigated for in-service, non-destructive testing. For this work low powered NMR equipment was used to follow the changes in 1H T2 as a function of degradation time in rubber samples placed aged at 100 °C. This latter technique measures the average (over all similar nuclei) relaxation times, and hence loses its specificity. However our work has shown that even this simpler method is sensitive to structural changes in the rubber. As rubber degrades it becomes stiffer and this overall bond relaxation time decreases. This type of equipment is simple enough to be made portable to be used in the field. This monitoring of degradation could then lead to using NMR to determine the performance of a part in service. The residual life

  1. Main: 1H82 [RPSD[Archive

    Full Text Available 1H82 トウモロコシ Corn Zea mays L. Polyamine Oxidase Precursor Name=Pao; Zea Mays Molecul...PEGKGREFFLYASSRRGYYGVWQEFEKQYPDANVLLVTVTDEESRRIEQQSDEQTKAEIMQVLRKMFPGKDVPDATDILVPRWWSDRFYKGTFSNWPVGVNRYEYDQLRAPVGRVYFTGEHTSEHYNGYVHGAYLSGIDSAEILINCAQKKMCKYHVQGKYD corn_1H82.jpg ...

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    Full Text Available 1H84 トウモロコシ Corn Zea mays L. Polyamine Oxidase Precursor Name=Pao; Zea Mays Molecul...GYYGVWQEFEKQYPDANVLLVTVTDEESRRIEQQSDEQTKAEIMQVLRKMFPGKDVPDATDILVPRWWSDRFYKGTFSNWPVGVNRYEYDQLRAPVGRVYFTGEHTSEHYNGYVHGAYLSGIDSAEILINCAQKKMCKYHVQGKYD corn_1H84.jpg ...

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    Full Text Available 1H86 トウモロコシ Corn Zea mays L. Polyamine Oxidase Precursor Name=Pao; Zea Mays Molecul...PEGKGREFFLYASSRRGYYGVWQEFEKQYPDANVLLVTVTDEESRRIEQQSDEQTKAEIMQVLRKMFPGKDVPDATDILVPRWWSDRFYKGTFSNWPVGVNRYEYDQLRAPVGRVYFTGEHTSEHYNGYVHGAYLSGIDSAEILINCAQKKMCKYHVQGKYD corn_1H86.jpg ...

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    Full Text Available 1H83 トウモロコシ Corn Zea mays L. Polyamine Oxidase Precursor Name=Pao; Zea Mays Molecul...GYYGVWQEFEKQYPDANVLLVTVTDEESRRIEQQSDEQTKAEIMQVLRKMFPGKDVPDATDILVPRWWSDRFYKGTFSNWPVGVNRYEYDQLRAPVGRVYFTGEHTSEHYNGYVHGAYLSGIDSAEILINCAQKKMCKYHVQGKYD corn_1H83.jpg ...

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    Full Text Available 1H81 トウモロコシ Corn Zea mays L. Polyamine Oxidase Precursor Name=Pao; Zea Mays Molecul...PEGKGREFFLYASSRRGYYGVWQEFEKQYPDANVLLVTVTDEESRRIEQQSDEQTKAEIMQVLRKMFPGKDVPDATDILVPRWWSDRFYKGTFSNWPVGVNRYEYDQLRAPVGRVYFTGEHTSEHYNGYVHGAYLSGIDSAEILINCAQKKMCKYHVQGKYD corn_1H81.jpg ...

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    Full Text Available 1H49 トウモロコシ Corn Zea mays L. Beta-Glucosidase, Chloroplast Precursor Name=Glu1; Zea...NPWIYMYPEGLKDLLMIMKNKYGNPPIYITENGIGDVDTKETPLPMEAALNDYKRLDYIQRHIATLKESIDLGSNVQGYFAWSLLDNFEWFAGFTERYGIVYVDRNNNCTRYMKESAKWLKEFNTAKKPSKKILTPA corn_1H49.jpg ...

  7. 1H NMR spectroscopic identification of a glue sniffing biomarker.

    Kwon, Bobae; Kim, Siwon; Kim, Sosun; Lee, Dong-Kye; Park, Yu-Jin; Kim, Myung-Duck; Lee, Jae-Shin; Kim, Suhkmann

    2011-06-15

    Organic solvent abuse typically involves sniffing organic solvents to experience the mind-altering conditions they induce. In Republic of Korea, organic solvent abuse is a serious social problem, especially among teenagers. Several studies have addressed the effects of organic solvent abuse on mind and body, but there are no simple methods by which such abuse can be positively identified. In this report, we describe a method for analyzing toluene metabolites (toluene is the main ingredient of glue) in glue-sniffers' urine using (1)H NMR spectroscopy. Toluene is a commonly used solvent in the rubber, paint, plastics, leather, printing, and chemical industries. Inhaled toluene is metabolized to hippuric acid in the liver and excreted in the urine. Hippuric acid is known as a good biomarker for biological monitoring of toluene exposure. We have scanned hippuric acid and other toluene metabolites by NMR spectroscopy and performed statistical multivariate analysis of the data. Based on this analysis, we sought to determine parameters by which glue-sniffing (toluene inhalation) behavior may be verified. We also demonstrate the use of a pattern recognition method for accurate and efficient analysis of NMR data. In comparison to conventional methods, such as mass spectroscopy coupled with liquid chromatography or gas chromatography, nuclear magnetic resonance spectroscopy has several advantages, including simple sample preparation, non-destructive sampling, accuracy, short acquisition time, and reproducibility in the determination of urinary hippuric acid. PMID:21316881

  8. Nuclear orientation with combined electric and magnetic interactions

    The combined interaction of a static electric field gradient and a static magnetic field with the electromagnetic moments of a nucleus is considered for the case of nuclear orientation at low temperature. The general expression of the angular distribution of a radiation emitted from the oriented state is developed for polycrystalline samples, where the principal axis of the electric field gradients are randomly distributed with respect to a fixed magnetic direction. Due to axial symmetry of the ensemble the effect of the quadrupole interaction is reduced to an attenuation factor on the usual Bsub(K) coefficients. Numerical calculations of these attenuation factors, for K=1, 2, 4 have been performed in the case of symmetric electric field gradient for a wide range of the electric to magnetic interactions ratio and spin values I=1/2, 1, 3/2, ...8. Typical attenuation curves for spin 5/2 and 9/2 are presented. Comparing the experimental anisotropies with the tabulated values, one can extract the quadrupole interaction value hωsub(Q)

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

    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)

  10. π-π Stacking, Hydrogen Bonding and Magnetic Coupling Mechanism on a Mono-nuclear Cu^Ⅱ Complex

    LI Hong; YU Li; ZHANG Shi-Guo; WANG Yu-Qing; SHI Jing-Min

    2012-01-01

    A new mono-nuclear CuII complex [Cu(DPP)(DP)Br](ClO4)H2O (DPP = 2-(3,5- dimethyl-1H-pyrazol-1-yl)-1,10-phenanthroline, DP = 3,5-dimethyl-1H-pyrazole) has been syn- thesized with 2-(3,5-dimethyl-1H-pyrazol-1-yl)-1,10-phenanthroline and 3,5-dimethyl-1H-pyrazole as ligands, and its crystal structure was determined by X-ray crystallography. The crystal is of monoclinic system, space group P21/c with a = 13.765(2), b = 17.044(3), c = 10.9044(16), β= 97.112(2)°, V = 2538.5(6)3, Z = 4, C22H24BrClCuN6O5, Mr = 631.37, Dc = 1.652 g/cm3, F(000) = 1276 and μ= 2.585 mm-1. In the crystal, DPP functions as a tridentate ligand and CuII ions assume a distorted square pyramidal geometry with Br atom lying on the apex, and at the same time, there is π-π stacking between adjacent complexes, which deals with two 1,10-phenanthroline plane rings. In addition to the π-π stacking, there are C-H···Br non-classic hydrogen bonds between adjacent complexes. The theoretical calculations reveal that the π-π stacking and C-H···Br non-classic hydrogen bond result in a weak anti-ferromagnetic interaction with 2J = -5.34 cm-1 and a weak ferromagnetic 2J = 5.92 cm-1, respectively. The magnetic coupling sign from the π-π stacking could be explained with McConnell I spin-polarization mechanism.

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

    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.

  12. Tunnel-diode resonator and nuclear magnetic resonance studies of low-dimensional magnetic and superconducting systems

    Yeninas, Steven Lee

    for the geometrically frustrated magnetic molecule W72V30 , and for BaMn2As2 and Ba1--x KxMn2As2 (with K-concentration x = 0.04 - 0.40) which are analogs of the high Tc iron arsenides. For the magnetic molecule W72V30, 1H and 51 V NMR and DC magnetization were used to investigate geometric frustration arising from antiferromagnetic interactions between 30 V 4+ ions occupying the edge sites of an icosidodecahedron. This system serves as a molecular representation of the 2-dimensional kagome lattice whose finite-size allows precise quantum calculations. Analysis of W72V 30 data suggests a large distribution of exchange values are necessary to characterize the field and temperature-dependent magnetic properties. For the insulating BaMn2As2 and hole-doped metallic Ba 1--xKxMn2As 2, both local moment antiferromagnets, 55Mn and 75As NMR spectra and spin-lattice relaxation rates 1/T 1 were conducted to investigate the local magnetic and electronic properties as a function of K-concentration x. NMR independently confirms G-type antiferromagnetism from spectra measurements, while a Korringa relation in 1/T1 indicates conduction electrons in both the Mn-3d and As-4d orbitals. The observation of ferromagnetic enhancement of the 55Mn NMR signal and no appreciable shift observed in the 75As spectra, combined with the absence of a structural phase transition in neutron diffraction measurements suggests, the K-doped system may exhibit a previously unseen coexistence of local-moment antiferromagnetism from the Mn2+ moments and weak ferromagnetism, possibly arising from the Mn-3d orbitals. In summary, the data presented in this work demonstrates the diversity of novel materials and physical properties which can be investigated by the RF techniques TDR and NMR.

  13. Magnetic La.sub.1-x./sub.Sr.sub.x./sub.MnO.sub.3./sub. nanoparticles as contrast agents for MRI: the parameters affecting 1H transverse relaxation

    Veverka, Pavel; Kaman, Ondřej; Kačenka, Michal; Herynek, V.; Veverka, Miroslav; Šantavá, Eva; Lukeš, I.; Jirák, Zdeněk

    2015-01-01

    Roč. 17, č. 1 (2015), s. 1-11. ISSN 1388-0764 R&D Projects: GA MPO FR-TI3/521; GA ČR(CZ) GAP108/11/0807 Institutional support: RVO:68378271 Keywords : manganese perovskites * manganite * magnetic nanoparticles * magnetic resonance imaging * relaxivity * core–shell particles Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.184, year: 2014

  14. Nuclear magnetic resonance wide-line study of hydrogen in the yttrium-yttrium dihydride system

    The 1H nuclear magnetic resonance was studied in the yttrium-hydrogen system YH/sub x/ in the composition range 0.20 less than or equal to x less than or equal to 1.98 and temperature range 77 K less than or equal to T less than or equal to 4900K. Both α- and β-phases of YH/sub x/ were investigated in polycrystalline (powdered) specimens. Rigid lattice proton resonance second moments were obtained for both α- and β-phase samples. Analysis of the second moment for α-YH/sub x/ (α-phase) indicates that the hydrogen resides in both the tetrahedral and octahedral interstitial sites of the hcp Y lattice. Second moment values for β-YH/sub x/ (β-phase) indicate that a sizeable fraction of the octahedral interstitial sites in the fcc yttrium metal lattice are occupied by hydrogen, while a nonnegligible fraction of the tetrahedral interstitial sites are vacant. For example, in YH/sub 1.98/, 28% of the octahedral sites are occupied, while 15% of the tetrahedral sites are vacant. The results for β-YH/sub x/ also indicate that as the H concentration increases, the probability of H occupation of octahedral sites increases

  15. Rapid detection of peanut oil adulteration using low-field nuclear magnetic resonance and chemometrics.

    Zhu, Wenran; Wang, Xin; Chen, Lihua

    2017-02-01

    (1)H low-field nuclear magnetic resonance (LF-NMR) and chemometrics were employed to screen the quality changes of peanut oil (PEO) adulterated with soybean oil (SO), rapeseed oil (RO), or palm oil (PAO) in ratios ranging from 0% to 100%. Significant differences in the LF-NMR parameters, single component relaxation time (T2W), and peak area proportion (S21 and S22), were detected between pure and adulterated peanut oil samples. As the ratio of adulteration increased, the T2W, S21, and S22 changed linearly; however, the multicomponent relaxation times (T21 and T22) changed slightly. The established principal component analysis or discriminant analysis models can correctly differentiate authentic PEO from fake and adulterated samples with at least 10% of SO, RO, or PAO. The binary blends of oils can be clearly classified by discriminant analysis when the adulteration ratio is above 30%, illustrating possible applications in screening the oil species in peanut oil blends. PMID:27596419

  16. Modelling studies in aqueous solution of lanthanide (III) chelates designed for nuclear magnetic resonance biomedical applications

    Henriques, E. S.; Geraldes, C. F. G. C.; Ramos, M. J.

    Molecular dynamics simulations and complementary modelling studies have been carried out for the [Gd(DOTA)·(H2O)]- and [Tm(DOTP)]5- chelates in aqueous media, to provide a better understanding of several structural and dynamical properties of these versatile nuclear magnetic resonance (NMR) probes, including coordination shells and corresponding water exchange mechanisms, and interactions of these complexes with alkali metal ions. This knowledge is of key importance in the areas of 1H relaxation and shift reagents for NMR applications in medical diagnosis. A new refinement of our own previously developed set of parameters for these Ln(III) chelates has been used, and is reported here. Calculations of water mean residence times suggest a reassessment of the characterization of the chelates' second coordination shell, one where the simple spherical distribution model is discarded in favour of a more detailed approach. Na+ probe interaction maps are in good agreement with the available site location predictions derived from 23Na NMR shifts.

  17. Investigation of reinforcement of the modified carbon black from wasted tires by nuclear magnetic resonance

    ZHOU Jie; YANG Yong-rong; REN Xiao-hong; STAPF Siegfried

    2006-01-01

    Pyrolysis has the potential of transforming waste into recyclable products. Pyrolytic carbon black (PCB) is one of the most important products from the pyrolysis of used tires. Techniques for surface modifications of PCB have been developed. One of the most significant applications for modified PCB is to reinforce the rubber matrix to obtain high added values. The transverse relaxation and the chain dynamics of vulcanized rubber networks with PCB and modified PCB were studied and compared with those of the commercial carbon blacks using selective 1H transverse relaxation (T2) experiments and dipolar correlation effect (DCE) experiments on the stimulated echo. Demineralization and coupling agent modification not only intensified the interactions between the modified PCB and the neighboring polyisoprene chains, but also increased the chemical cross-link density of the vulcanized rubber with modified PCB. The mechanical testing of the rubbers with different kinds of carbon blacks showed that the maximum strain of the rubber with modified PCB was improved greatly. The mechanical testing results confirmed the conclusion obtained by nuclear magnetic resonance (NMR). PCB modified by the demineralization and NDZ-105 titanate coupling agent could be used to replace the commercial semi-reinforcing carbon black.

  18. H-1 Nuclear Magnetic Resonance Metabolomics Analysis Identifies Novel Urinary Biomarkers for Lung Function

    Chronic obstructive pulmonary disease (COPD), characterized by chronic airflow limitation, is a serious and growing public health concern. The major environmental risk factor for COPD is tobacco smoking, but the biological mechanisms underlying COPD are not well understood. In this study, we used proton nuclear magnetic resonance (1H-NMR) spectroscopy to identify and quantify metabolites associated with lung function in COPD. Plasma and urine were collected from 197 adults with COPD and from 195 adults without COPD. Samples were assayed using a 600 MHz NMR spectrometer, and the resulting spectra were analyzed against quantitative spirometric measures of lung function. After correcting for false discoveries and adjusting for covariates (sex, age, smoking) several spectral regions in urine were found to be significantly associated with baseline lung function. These regions correspond to the metabolites trigonelline, hippurate and formate. Concentrations of each metabolite, standardized to urinary creatinine, were associated with baseline lung function (minimum p-value = 0.0002 for trigonelline). No significant associations were found with plasma metabolites. Two of the three urinary metabolites positively associated with baseline lung function, i.e. hippurate and formate, are often related to gut microflora. This suggests that the microbiome composition is variable between individuals with different lung function. Alternatively, the nature and origins of all three associated metabolites may reflect lifestyle differences affecting overall health. Our results will require replication and validation, but demonstrate the utility of NMR metabolomics as a screening tool for identifying novel biomarkers of lung disease or disease risk.

  19. Application of nuclear magnetic resonance spectroscopy of human serum to leukaemia clinical study

    To study metabolism of phospholipid and lipoprotein and lactic acid by nuclear magnetic resonance spectroscopy, and investigate the feasibility in leukaemia clinical study, serum sample of leukaemia patients and healthy controls were collected and measured with MSL-300 MHz spectrometer. The phospholipid contents were known by contrast relatively integral area of PC signal and (PE + SM) signal with 31P-NMRS. A lineshape fitting model was used to analyze various lipoprotein and lactic acid changes by methyl and methylene groups in 1H-NMR spectrum of leukaemia serum. In spectra of serum of leukaemia patients, the phospholipid signals strength were significantly decreased. It reflected lower phosphatidylcholine and phosphatidylcholine and sphingomyelin content in serum of leukemia patients, especially for original un-treatment patient. The various lipoprotein contents were difference and lactic acid was significantly higher than normal control. NMR technique is a convenience method. It can primely reflect the difference of phospholipid and lipoprotein and lactic acid between leukaemia patients and normal control from molecule level. It provided a new method for study of leukaemia and is worthy to further study

  20. Sedimentary rock porosity studied by electromagnetic techniques: nuclear magnetic resonance and dielectric permittivity

    Ramia, M. E.; Martín, C. A.

    2015-02-01

    The present work involves a comprehensive experimental study of porosity and pore size distribution of sedimentary rocks, from oil fields formations, by means of two electromagnetic techniques, namely proton (1H) nuclear magnetic resonance (NMR) and dielectric complex constant (DCC) as function of the frequency, both providing complementary results. The NMR yields an accurate determination of the relative pore size distribution and both movable and irreducible fluids. The DCC measurement provides the direct current electrical resistivity of the samples with different degrees of hydration. Thus, combining the results of both techniques allows the determination of the tortuosity index, by means of Archie's relation, and from it the average pore channel length. These measurements are performed on fully hydrated (saturated), centrifuged, dried, and cleaned rocks and also on samples with the irreducible fluids. Finally, the results are complemented with capillary pressure measurements to obtain the total volume associated with the pore channels related to the rock permeability. Additionally, the work presents a particular method to use a network analyzer to measure the DCC.

  1. H-1 Nuclear Magnetic Resonance Metabolomics Analysis Identifies Novel Urinary Biomarkers for Lung Function

    MCClay, Joseph L.; Adkins, Daniel E.; Isern, Nancy G.; O' Connell, Thomas M.; Wooten, Jan B.; Zedler, Barbara K.; Dasika, Madhukar S.; Webb, B. T.; Webb-Robertson, Bobbie-Jo M.; Pounds, Joel G.; Murrelle, Edward L.; Leppert, Mark F.; van den Oord, Edwin J.

    2010-06-04

    Chronic obstructive pulmonary disease (COPD), characterized by chronic airflow limitation, is a serious and growing public health concern. The major environmental risk factor for COPD is tobacco smoking, but the biological mechanisms underlying COPD are not well understood. In this study, we used proton nuclear magnetic resonance (1H-NMR) spectroscopy to identify and quantify metabolites associated with lung function in COPD. Plasma and urine were collected from 197 adults with COPD and from 195 adults without COPD. Samples were assayed using a 600 MHz NMR spectrometer, and the resulting spectra were analyzed against quantitative spirometric measures of lung function. After correcting for false discoveries and adjusting for covariates (sex, age, smoking) several spectral regions in urine were found to be significantly associated with baseline lung function. These regions correspond to the metabolites trigonelline, hippurate and formate. Concentrations of each metabolite, standardized to urinary creatinine, were associated with baseline lung function (minimum p-value = 0.0002 for trigonelline). No significant associations were found with plasma metabolites. Two of the three urinary metabolites positively associated with baseline lung function, i.e. hippurate and formate, are often related to gut microflora. This suggests that the microbiome composition is variable between individuals with different lung function. Alternatively, the nature and origins of all three associated metabolites may reflect lifestyle differences affecting overall health. Our results will require replication and validation, but demonstrate the utility of NMR metabolomics as a screening tool for identifying novel biomarkers of lung disease or disease risk.

  2. Nuclear magnetic resonance metabonomic profiling using tO2PLS

    Graphical abstract: -- Highlights: •Transposition of O2PLS input matrix (tO2PLS) to analyze metabonomics data. •tO2PLS specific components describe features that separate and define sample groups. •Application of tO2PLS to a 1H NMR metabonomics study of black bream fish. -- Abstract: Blood plasma collected from adult fish (black bream, Sparidae) exposed to a dose of 5 mg kg−1 17β-estradiol underwent metabonomic profiling using nuclear magnetic resonance (NMR). An extension of the orthogonal 2 projection to latent structure (O2PLS) analysis, tO2PLS, was proposed and utilized to classify changes between the control and experimental metabolic profiles. As a bidirectional modeling tool, O2PLS examines the (variable) commonality between two different data blocks, and extracts the joint correlations as well as the unique variations present within each data block. tO2PLS is a proposed matrix transposition of O2PLS to allow for commonality between experiments (spectral profiles) to be observed, rather than between sample variables. tO2PLS analysis highlighted two potential biomarkers, trimethylamine-N-oxide (TMAO) and choline, that distinguish between control and 17β-estradiol exposed fish. This study presents an alternative way of examining spectroscopic (metabolite) data, providing a method for the visual assessment of similarities and differences between control and experimental spectral features in large data sets

  3. A proton nuclear magnetic resonance assignment and secondary structure determination of recombinant human thioredoxin

    Two-dimensional 1H NMR spectroscopy has been applied to a structural analysis of the reduced form of a recombinant human thioredoxin, a ubiquitous dithiol oxidoreductase recently isolated from an immunocompetent lymphoblastoid cell line. The sequential assignment of the spectrum, including all proline residues, has been accomplished by using experiments to demonstrate through-bond and through-space connectivities. The secondary structure has been determined by a qualitative interpretation of nuclear Overhauser effects, NH exchange data, and 3JHNα coupling constants. The secondary structure was found to be similar to that of the X-ray structure of Escherichia coli thioredoxin, consisting of a mixed five-stranded β-sheet surrounded by four α-helices. The assignment and structural characterization of human thioredoxin was facilitated by the increased resolution and sensitivity afforded by a magnetic field strength of 600 MHz and required the use of two temperatures and two pH conditions to resolve ambiguities caused by a duplication of resonances. This duplication, extending from Phe-41 to Val-59, and including Lys-3-Ile-5, Val-24, Val-25, Asn-39, and Ile-101-Glu-103, appears to be due to heterogeneity arising from the presence or absence of the N-terminal methionine

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

    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

  5. Magnetism and superconductivity in iron-based superconductors as probed by nuclear magnetic resonance

    Hammerath, Franziska

    2012-07-01

    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 LaO{sub 1-x}F{sub x}FeAs and LiFeAs.

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

    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.

  7. Nuclear magnetic resonance. Present results and its application to renal pathology. Experimental study of hydronephrosis

    Results of proton nuclear magnetic resonance imaging and relaxation time measurement of experimental hydronephrosis in mice are presented. The study is preceded by a description of the physical principles underlying the phenomenon of nuclear magnetic resonance and of its biomedical applications and with a review of the clinical use of NMR imaging in renal pathology

  8. Nuclear magnetic shielding in molecules. The application of GIAO's in LCAO-Xα-calculations

    A nonempirical method for the calculation of nuclear magnetic shielding based on the four current density functional formalism is presented. Using SCF-LCAO-Xα-calculations with application of GIAO's effective one particle equations are solved. The results for nuclear magnetic shielding in diatomic molecules are of good quality, compared with other theoretical and experimental data. (orig.)

  9. Applications of nuclear magnetic resonance imaging in process engineering

    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.

  10. Nuclear Magnetic Resonance Study of Nanoscale Ionic Materials

    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.

  11. Phosphorus-31 nuclear magnetic resonance studies of photosynthesizing Chlorella

    Phosphorus-31 nuclear magnetic resonance studies of intact Chlorella cells under light and dark conditions are described. Psub(i), ATP, NAD, UDP-glucose and polyphosphate were observed in the cell. The presence of two compartments was postulated from two intracellular Psub(i) signals, whose chemical shift values were dependent on illumination. These two Psub(i) signals were assigned to those in the stroma of chloroplasts and in the cytoplasm based on their response to the light and dark cycle, and to the treatment of cells with 3-(3,4-dichlorophenyl)-1,1-dimethylurea. In the light the chloroplastic pH became more alkaline, while the cytoplasmic pH became more acidic. An increase in ATP was also observed upon illumination. (orig.)

  12. Explosives Detection Using Magnetic and Nuclear Resonance Techniques

    Fraissard, Jacques

    2009-01-01

    Nuclear quadrupole resonance (NQR) a highly promising new technique for bulk explosives detection: relatively inexpensive, more compact than NMR, but with considerable selectivity. Since the NQR frequency is insensitive to long-range variations in composition, mixing explosives with other materials, such as the plasticizers in plastic explosives, makes no difference. The NQR signal strength varies linearly with the amount of explosive, and is independent of its distribution within the volume monitored. NQR spots explosive types in configurations missed by the X-ray imaging method. But if NQR is so good, why it is not used everywhere? Its main limitation is the low signal-to-noise ratio, particularly with the radio-frequency interference that exists in a field environment, NQR polarization being much weaker than that from an external magnetic field. The distinctive signatures are there, but are difficult to extract from the noise. In addition, the high selectivity is partly a disadvantage, as it is hard to bui...

  13. High resolution spectroscopy in solids by nuclear magnetic resonance

    The nuclear magnetic resonance (NMR) techniques for High Resolution Spectroscopy in Solids are described. Also the construction project of a partially home made spectrometer and its applications in the characterization of solid samples are shown in detail. The high resolution spectrometer used is implemented with the double resonance multiple pulses sequences and magic angle spinning (MAS) and can be used with solid and liquid samples. The maximum spinning frequency for the MAS experiment is in excess of 5 Khz, the double resonance sequences can be performed with any type of nucleus, in the variable temperature operating range with nitrogen gas: -1200 C to +1600 C, and is fully controlled by a Macintosh IIci microcomputer. (author)

  14. High field nuclear magnetic resonance application to polysaccharide chemistry

    Nuclear magnetic resonance has been applied to polysaccharide chemistry using time averaging technique and high fields (100 and 250 MHz). The three methyl signals of methyl cellulose and cellulose triacetate are separated, and the C-6 substituent has been identified. Biosynthesis of bacterial cellulose has been performed using deuterium labelled D-glucose and Acetobacter xylinum. Per-acetylated derivative of bacterial cellulose has been studied by NMR; this study permitted us to determine the quantity of deuterium on each position of the anhydro-glucose unit in the polymer. NMR has also been used to see the anomeric end chain of cellulose and amylose derivatives and to show the fixation of bromine and t-butyl group on the free anomeric end chain of cellulose triacetate. (author)

  15. State interrogation in nuclear magnetic resonance quantum-information processing

    Reconstruction of a reduced density operator for weakly coupled systems of spins (1/2) from fits to nuclear magnetic resonance spectra is described in detail. Particular emphasis is placed on data treatment procedures that specify fewer than the 3n complete spectra that are implicitly prescribed in published references to state tomography on n-spin systems. It is shown that if the density operator is expanded in the so-called product-operator basis, it is always possible to estimate a desired coefficient in the expansion by measuring a single spectral multiplet. This simple observation can substantially reduce the experimental effort required for either complete density-matrix reconstruction or estimation of subsets of the coefficients in the product-operator expansion. A simple iterative algorithm can be used to produce reduced measurement procedures for experiments involving small numbers of qubits

  16. Physical principles of medical applications of nuclear magnetic resonance

    The theoretical principles of zeumatography a new method of visualization of internal organs in the human body are discussed. Zeumatography is a method based on the phenomenon of Nuclear Magnetic Resonance. It opens fairly broad possibilities in diagnosis as well as in theoretical research. Its sensitivity and accuracy will probably be equal to those of X-ray emission and computer tomography. The main advantage of the method which will make its future use particularly widespread is that it eliminates exposure to ionizing radiation, makes possible determination of the character of the tissue based on the content of hydrogen nucleus in a given area and enables differentiation of the tissues with different interatomic bonds, that is those which contain different chemical compounds. (author)

  17. NMR in pulsed magnetic field

    Abou-Hamad, Edy

    2011-09-01

    Nuclear magnetic resonance (NMR) experiments in pulsed magnetic fields up to 30.4 T focused on 1H and 93Nb nuclei are reported. Here we discuss the advantage and limitation of pulsed field NMR and why this technique is able to become a promising research tool. © 2011 Elsevier Inc. All Rights Reserved.

  18. Method to calculate reservoir permeability using nuclear magnetic resonance logging and capillary pressure data

    In view of the problems of SDR and Tim-Coates models in calculating permeability using nuclear magnetic resonance logging data, based on the fact that nuclear magnetic resonance T2 distribution and capillary pressure curves reflect the reservoir pore structure, a method was presented to calculate reservoir permeability using nuclear magnetic resonance logging and capillary pressure data. The correlation between Swanson parameter and permeability was established by comparing 31 core samples which were measured by mercury penetration and nuclear magnetic resonance logging. Considering the problem that capillary pressure data are limited by their quantity, the good correlativity between T2 geometric mean value of lateral relaxation time of nuclear magnetic resonance and Swanson parameter can be used to determine the Swanson parameter and to calculate reservoir permeability consecutively. The processing of the data in well A yields a permeability closer to the result of core analysis, and this indicates the accuracy of the method. (authors)

  19. 脑胶质瘤的1H MRS

    杨桂芬; 田伟

    2005-01-01

    活体质子磁共振波谱(proton magnetic resonance spectroscopy,1H MRS)由于能够无创性检测肿瘤组织及正常表观组织代谢物的变化,目前在胶质瘤的分级、诊断、范围确定及鉴别诊断中有积极的应用价值。本文主要介绍1H MRS在胶质瘤中的研究现状。

  20. Thermogravimetric analysis of petroleum asphaltenes along with estimation of average chemical structure by nuclear magnetic resonance spectroscopy

    Combining with the 1H and 13C nuclear magnetic resonance (NMR) determinations, elemental analysis and molecular weight measurement, average molecular formula of the chemical unit for the asphaltenes from Chinese Daqing crude oil were calculated. Thermal pyrolysis kinetics of the asphaltenes had been studied using thermogravimetric analysis (TGA). The distributed activation energy model (DAEM) was used to analyze these complex systems. The results show that the peak activation energy for pyrolysis of the asphaltenes is 245 kJ mol-1 and the pre-exponential factor is 5.88 x 1014 s-1. The DAEM method presented reasonably good results of the prediction of the weight loss curves. A linear relationship can be found from the plots of logarithm of the pre-exponential factor against the activation energy at selected conversion values. This phenomenon known as the compensation effect was explained and it was in agreement with the estimated chemical structure determined by NMR

  1. Molecular interactions between green tea catechins and cheese fat studied by solid-state nuclear magnetic resonance spectroscopy.

    Rashidinejad, Ali; Birch, Edward J; Hindmarsh, Jason; Everett, David W

    2017-01-15

    Molecular integrations between green tea catechins and milk fat globules in a cheese matrix were investigated using solid-state magic angle spinning nuclear magnetic resonance spectroscopy. Full-fat cheeses were manufactured containing free catechin or free green tea extract (GTE), and liposomal encapsulated catechin or liposomal encapsulated GTE. Molecular mobility of the carbon species in the cheeses was measured by a wide-line separation technique. The (1)H evolution frequency profile of the (13)C peak at 16ppm obtained for the control cheese and cheeses containing encapsulated polyphenols (catechin or GTE) were similar, however, the spectrum was narrower for cheeses containing free polyphenols. Differences in spectral width indicates changes in the molecular mobility of --CH3- or -C-C-PO4- species through hydrophobic and/or cation-π associations between green tea catechins and cheese fat components. However, the similar spectral profile suggests that encapsulation protects cheese fat from interaction with catechins. PMID:27542471

  2. Density functional theory (DFT) calculations of the proton nuclear magnetic resonance (NMR) spin-Hamiltonian parameters for serine

    1H nuclear magnetic resonance spin-Hamiltonian parameters: chemical shifts δ and indirect spin–spin coupling constants J, have been calculated for serine, a brain metabolite. Serine molecules in the gas-phase as well as in solution in water have been investigated using density functional theory. Solvent and conformer effects as well as zero-point vibrational corrections have been taken into account. For the non-vibrating molecule, the best agreement is obtained when solvent and conformer effects are included. Zero-point vibrational corrections improve the agreement with experimental values, leading to a root mean square deviation of 0.05 ppm for chemical shifts and 0.7 Hz for spin–spin coupling constants

  3. Study of the reinforcement of rubber styrene-butadiene with mesoporous silices by solid-state nuclear magnetic resonance

    The knowledge about the interaction rubber/filler for the rubber reinforced with carbon black of silica is important to understand the physical properties, which determine the reinforcement. This paper presents a comparative study of the interactions between styrene butadiene rubber (SBR) and silica for a silica Ultrasil type and mesoporous silica MCM-41 type prepared by different procedures, based on solid state nuclear magnetic resonance: 1H MAS NMR; 13C MAS NMR, 13C CP/MAS, 29Si MAS and 29Si CP/MAS NMR. Mesoporous silica synthesized under certain specific conditions showed better interaction with the rubber than the ultrasil VN3 silica, commonly used as a reinforcement load. Mechanical tests for the SBR vulcanised with this silica indicate an important increase for values of elongation and tearing resistance, but an increase in the vulcanization time in it is compared with the SBR vulcanise with Ultrasil

  4. Nuclear magnetic resonance studies of materials for spintronic applications

    Since its discovery in liquids and also in solid matter in 1946, nuclear magnetic resonance (NMR) has been widely established as a standard tool for structural analysis of a wide range of materials. This review outlines recent NMR studies on materials considered to be useful in spintronic applications. Spintronics is a new research field which combines the use of both the charge and the spin of an electron as information carriers, which promises distinct advantages over conventional electronics which makes use only of the charge of electrons. A successful application of materials in spintronic devices requires a detailed knowledge of the interplay between the structure and the magnetic and electronic properties on an atomic scale. NMR probes the local environments of the active nuclei. This local character of NMR arises from local contributions to the hyperfine field, namely, the transferred field which depends on the nearest neighbour atoms and their magnetic moments. This enables NMR to study the structural properties of bulk samples as well as of thin films of spin polarized materials. Moreover, NMR spectroscopy also provides an indirect tool to measure the density of states of spin polarized materials via a measurement of the temperature dependence of the spin-lattice relaxation time. This review starts with an introduction into the basic concepts of NMR followed by a description of the important aspects of a pulsed NMR experiment. Thereafter, information obtained by an NMR experiment is addressed. In the subsequent main part, selected recent NMR studies (published roughly after the year 2000) of materials for spintronic applications are presented including NMR studies of, for example, Co thin films, Heusler compounds, double perovskites and pyrites. (topical review)

  5. Theoretical study on nuclear structure by the multiple Coulomb scattering and magnetic scattering of relativistic electrons

    Liu, Jian; Zhang, Xin; Xu, Chang; Ren, Zhongzhou

    2016-04-01

    Electron scattering is an effective method to study the nuclear structure. For the odd-A nuclei with proton holes in the outmost orbits, we investigate the contributions of proton holes to the nuclear quadrupole moments Q and magnetic moments μ by the multiple Coulomb scattering and magnetic scattering. The deformed nuclear charge densities are constructed by the relativistic mean-field (RMF) models. Comparing the theoretical Coulomb and magnetic form factors with the experimental data, the nuclear quadrupole moments Q and nuclear magnetic moments μ are investigated. From the electron scattering, the wave functions of the proton holes of odd-A nuclei can be tested, which can also reflect the validity of the nuclear structure model.

  6. Tracking Transitions in Spider Wrapping Silk Conformation and Dynamics by (19)F Nuclear Magnetic Resonance Spectroscopy.

    Sarker, Muzaddid; Orrell, Kathleen E; Xu, Lingling; Tremblay, Marie-Laurence; Bak, Jessi J; Liu, Xiang-Qin; Rainey, Jan K

    2016-05-31

    Aciniform silk protein (AcSp1) is the primary component of wrapping silk, the toughest of the spider silks because of a combination of high tensile strength and extensibility. Argiope trifasciata AcSp1 contains a core repetitive domain with at least 14 homogeneous 200-amino acid units ("W" units). Upon fibrillogenesis, AcSp1 converts from an α-helix-rich soluble state to a mixed α-helical/β-sheet conformation. Solution-state nuclear magnetic resonance (NMR) spectroscopy allowed demonstration of variable local stability within the W unit, but comprehensive characterization was confounded by spectral overlap, which was exacerbated by decreased chemical shift dispersion upon denaturation. Here, (19)F NMR spectroscopy, in the context of a single W unit (W1), is applied to track changes in structure and dynamics. Four strategic positions in the W unit were mutated to tryptophan and biosynthetically labeled with 5-fluorotryptophan (5F-Trp). Simulated annealing-based structure calculations implied that these substitutions should be tolerated, while circular dichroism (CD) spectroscopy and (1)H-(15)N chemical shift displacements indicated minimal structural perturbation in W1 mutants. Fiber formation by W2 concatemers containing 5F-Trp substitutions in both W units demonstrated retention of functionality, a somewhat surprising finding in light of sequence conservation between species. Each 5F-Trp-labeled W1 exhibited a unique (19)F chemical shift, line width, longitudinal relaxation time constant (T1), and solvent isotope shift. Perturbation to (19)F chemical shift and nuclear spin relaxation parameters reflected changes in the conformation and dynamics at each 5F-Trp site upon addition of urea and dodecylphosphocholine (DPC). (19)F NMR spectroscopy allowed unambiguous localized tracking throughout titration with each perturbant, demonstrating distinct behavior for each perturbant not previously revealed by heteronuclear NMR experiments. PMID:27153372

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

    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.

  8. Nuclear orientation experiments on the magnetic moments of europium and gadolinium nuclei

    In this thesis, experimental results on the ground state nuclear magnetic moments of europium and gadolinium isotopes are presented. The nuclear orientation experiments were performed on europium and gadolinium nuclei embedded in several host lattices. Attention is paid to the hyperfine interactions of the ions. Nuclear moments are discussed in the context of nuclear shell model. The theoretical framework is described for nuclear structure and low temperature nuclear orientation. Furthermore, the experimental techniques, the technical arrangement of the orientation apparatus, the methods for radiative detection and the use of nuclear orientation thermometry are described. (Auth.)

  9. Study of hydrogen in coals, polymers, oxides, and muscle water by nuclear magnetic resonance; extension of solid-state high-resolution techniques. [Hydrogen molybdenum bronze

    Ryan, L.M.

    1981-10-01

    Nuclear magnetic resonance (NMR) spectroscopy has been an important analytical and physical research tool for several decades. One area of NMR which has undergone considerable development in recent years is high resolution NMR of solids. In particular, high resolution solid state /sup 13/C NMR spectra exhibiting features similar to those observed in liquids are currently achievable using sophisticated pulse techniques. The work described in this thesis develops analogous methods for high resolution /sup 1/H NMR of rigid solids. Applications include characterization of hydrogen aromaticities in fossil fuels, and studies of hydrogen in oxides and bound water in muscle.

  10. Density functional theory calculations of the nuclear magnetic resonance spin-Hamiltonian parameters for two polyamines of prostate tissue: spermidine and spermine

    1H nuclear magnetic resonance (NMR) spin-Hamiltonian parameters: chemical shifts δ and spin–spin coupling constants J have been calculated for the two polyamines: spermidine and spermine present in prostate tissue. Molecules in the gas phase as well as in solution in water have been investigated using density functional theory calculations. From calculated δ and J values, NMR spectra have been simulated and compared to the experimental ones we acquired at 400 MHz for each polyamine in solution in D2O. From these comparisons, reliable NMR parameters are proposed for spermidine and spermine, among which the J constants were until now unknown for these two molecules

  11. Nuclear magnetic resonance study of the ferroelastic phase transition of order-disorder type in [N(C2H5)4]2CdCl4

    Lim, Ae Ran; Kim, Min Soo; Lim, Kye-Young

    2016-08-01

    This study uses nuclear magnetic resonance (NMR) techniques to examine the detailed changes in [N(C2H5)4]2CdCl4 around its phase transition at the temperature TC = 284 K. The chemical shifts and spin-lattice relaxation times in the rotating frame (T1ρ) were determined from 1H magic angle spinning (MAS) NMR and 13C cross-polarization (CP)/MAS NMR spectra. The two sets of inequivalent 1H and 13C nuclei in CH3 and CH2 were distinguished. A ferroelastic phase transition was observed at TC, without structural symmetry change. The phase transition is mainly attributed to the orientational ordering of the [N(C2H5)4]+ cations, and the spectral splitting at low temperature is associated with different ferroelastic domains.

  12. On phase separation in La1.89Sr0.11CuO4H0.11 by 1H NMR

    Nuclear magnetic resonance measurements of the 1H spectra in La1.89Sr0.11CuO4H0.11 have been made. Results are reported for temperatures 5 K ≤ T ≤ 150 K at a field of 7.05 T. The two narrow and broad, 1H resonance lines were observed. The linewidths and intensities of these lines were discussed in terms of the hydrogen concentration and properties of the earlier reported phases in La1.89Sr0.11Cu0.995Fe0.005 O4Hy. (orig.)

  13. {sup 1}H MR spectroscopy in epilepsy

    Hajek, Milan [MR Unit, Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague (Czech Republic)], E-mail: miha@medicon.cz; Dezortova, Monika [MR Unit, Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague (Czech Republic)], E-mail: mode@medicon.cz; Krsek, Pavel [Department of Pediatric Neurology, Charles University, Second Medical School, Motol Hospital, V Uvalu 84, 150 06 Prague 5 (Czech Republic)], E-mail: pavel.krsek@post.cz

    2008-08-15

    The introduction to the application of {sup 1}H MR spectroscopy for clinical and research studies of mesial temporal and extratemporal epilepsies is done. The techniques of single voxel and spectroscopic imaging are discussed and the analysis of {sup 1}H MR spectra together with basic metabolic descriptions is presented.

  14. 1H MR spectroscopy in epilepsy

    The introduction to the application of 1H MR spectroscopy for clinical and research studies of mesial temporal and extratemporal epilepsies is done. The techniques of single voxel and spectroscopic imaging are discussed and the analysis of 1H MR spectra together with basic metabolic descriptions is presented

  15. Analysis of the Thermal Degradation of the Individual Anthocyanin Compounds of Black Carrot (Daucus carota L.): A New Approach Using High-Resolution Proton Nuclear Magnetic Resonance Spectroscopy.

    Iliopoulou, Ioanna; Thaeron, Delphine; Baker, Ashley; Jones, Anita; Robertson, Neil

    2015-08-12

    The black carrot dye is a mixture of cyanidin molecules, the nuclear magnetic resonance (NMR) spectrum of which shows a highly overlapped aromatic region. In this study, the (1)H NMR (800 MHz) aromatic chemical shifts of the mixture were fully assigned by overlaying them with the characterized (1)H NMR chemical shifts of the separated compounds. The latter were isolated using reverse-phase high-performance liquid chromatography (RP-HPLC), and their chemical shifts were identified using (1)H and two-dimensional (2D) correlation spectroscopy (COSY) NMR spectroscopy. The stability of the black carrot mixture to heat exposure was investigated at pH 3.6, 6.8, and 8.0 by heat-treating aqueous solutions at 100 °C and the powdered material at 180 °C. From integration of high-resolution (1)H NMR spectra, it was possible to follow the relative degradation of each compound, offering advantages over the commonly used ultraviolet/visible (UV/vis) and HPLC approaches. UV/vis spectroscopy and CIE color measurements were used to determine thermally induced color changes, under normal cooking conditions. PMID:26160425

  16. Nuclear magnetic resonance and relaxation studies of the structure and segmental motions of 4-vinyl-pyridinic polymers in solution

    The poly 4-vinylpyridine, its quaternized products from HBr and n-alkyl-bromides, and its N-oxide form have been investigated by nuclear magnetic resonance of proton at 100 and 250 MHz and carbon-13 at 25.15 MHz, The 1H and 13C relaxation data of poly-vinylpyridine and its ionized form have been correlated with conformational calculations. They have been interpreted in terms of an isotropic motion of the macromolecular segments introducing a correlation times distribution and of an oscillation motion of the pyridyl groups. The same treatment have been used for the 13C relaxation data of the poly 4- vinyl-pyridines quaternized at various rates by n-alkyl-bromides. The 13C relaxation times in the side-chains have been interpreted first by semi-empirical equations assuming an exponential gradient of the diffusion coefficients along them, and also by a Monte Carlo simulation of the motions. The results have shown that the quaternization induces a strong rigidity of the macromolecular backbone and that the dominant effect is the electrostatic interactions. On the other hand it seems that the motion of pyridyl rings is not affected. Moreover we have found a range of oscillation amplitudes in agreement with conformational energy calculations and the results obtained from a conformational study of the poly 4-vinylpyridine N-oxide by 1H and 13C NMR contact shifts induced by Ni II paramagnetic ions. (author)

  17. Screening Brazilian commercial gasoline quality by hydrogen nuclear magnetic resonance spectroscopic fingerprintings and pattern-recognition multivariate chemometric analysis.

    Flumignan, Danilo Luiz; Boralle, Nivaldo; de Oliveira, José Eduardo

    2010-06-30

    The identification of gasoline adulteration by organic solvents is not an easy task, because compounds that constitute the solvents are already in gasoline composition. In this work, the combination of Hydrogen Nuclear Magnetic Resonance ((1)H NMR) spectroscopic fingerprintings with pattern-recognition multivariate Soft Independent Modeling of Class Analogy (SIMCA) chemometric analysis provides an original and alternative approach to screening Brazilian commercial gasoline quality in a Monitoring Program for Quality Control of Automotive Fuels. SIMCA was performed on spectroscopic fingerprints to classify the quality of representative commercial gasoline samples selected by Hierarchical Cluster Analysis (HCA) and collected over a 6-month period from different gas stations in the São Paulo state, Brazil. Following optimized the (1)H NMR-SIMCA algorithm, it was possible to correctly classify 92.0% of commercial gasoline samples, which is considered acceptable. The chemometric method is recommended for routine applications in Quality-Control Monitoring Programs, since its measurements are fast and can be easily automated. Also, police laboratories could employ this method for rapid screening analysis to discourage adulteration practices. PMID:20685442

  18. Hydration kinetics of cements by Time-Domain Nuclear Magnetic Resonance: Application to Portland-cement-derived endodontic pastes

    Time-Domain Nuclear Magnetic Resonance (TD-NMR) of 1H nuclei is used to monitor the maturation up to 30 days of three different endodontic cement pastes. The “Solid–liquid” separation of the NMR signals and quasi-continuous distributions of relaxation times allow one to follow the formation of chemical compounds and the build-up of the nano- and subnano-structured C–S–H gel. 1H populations, distinguished by their different mobilities, can be identified and assigned to water confined within the pores of the C–S–H gel, to crystallization water and Portlandite, and to hydroxyl groups. Changes of the TD-NMR parameters during hydration are in agreement with the expected effects of the different additives, which, as it is known, can substantially modify the rate of reactions and the properties of cementitious pastes. Endodontic cements are suitable systems to check the ability of this non-destructive technique to give insight into the complex hydration process of real cement pastes.

  19. Novel nuclear magnetic resonance techniques for studying biological molecules

    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.

  20. Novel nuclear magnetic resonance techniques for studying biological molecules

    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.

  1. Nuclear magnetic resonance experiments with dc SQUID amplifiers

    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 1017 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

  2. 轻度认知功能障碍和轻度Alzheimer病的1H-MRS研究%Brain proton magnetic resonance spectroscopy in mild cognitive impairment and mild Alzheimer disease

    丁萍; 苗华栋; 嵇鸣; 魏文石

    2008-01-01

    目的 探讨质子磁共振波谱(1H-MRS)对轻度认知功能障碍(MCI)和轻度Alzheimer病(AD)的诊断和鉴别诊断的作用.方法 采用刺激回波序列(STEAM),对30例MCI患者、30例轻度AD患者和30例性别、年龄、文化程度匹配健康对照的双侧内侧颞叶1H-MRS进行分析,比较各组间N-乙酰天门冬氨酸/肌酸(NAA/Cr)、胆碱,肌酸(Cho/Cr)和肌醇/肌酸(MI/Cr)、N-乙酰天门冬氨酸/肌醇(NAA/MI)比值及不对称指数的差别,并对MCI和轻度AD组的简易智能精神状态量表(MMSE)评分与NAA/Cr、Cho/Cr、MI/Cr、NAA/MI进行相关分析. 结果 MCI组的左侧NAA/Cr及轻度AD组的两侧NAA/Cr显著低于对照组(P<0.05),MCI组和轻度AD组的两侧NAA/Cr无显著差异(P>0.05).三组间的Cho/Cr无差异(P>0.05).MCI组和轻度AD组的两侧MI/Cr显著高于对照组(P<0.05),MCI组和轻度AD组的左侧MI/Cr有显著差异(P<0.05).MCI组和轻度AD组的两侧NAA/MI显著低于对照组(P<0.05),MCI组和轻度AD组的左侧NAA/MI有显著差异(P<0.05).MCI、轻度AD和对照组的NAA/Cr、MI/Cr、NAA/MI有一定的左侧偏性,但三组之间的代谢物不对称指数无显著差异(P>0.05).MCI和轻度AD两组的MMSE评分与两侧NAA/Cr明显正相关(P0.<05).轻度AD组的MMSE评分与右NAA/MI明显正相关(P<0.05).两组合并的MMSE评分与左NAA/Cr、MI/Cr、NAA/MI明显正相关(P<0.05).结论 MCI、轻度AD患者内侧颞叶NAA/Cr、NAA/MI比值的降低与MI/Cr比值的升高,以及MCI和轻度AD患者的左侧MI/Cr、NAA/MI有显著差异,为MCI和AD的早期诊断和鉴别诊断提供参考.MCI和轻度AD患者NAA/Cr、NAA/MI的变化与痴呆严重程度的相关性,对MCI和AD的疾病进展和治疗监测有重要作用.1H-MRS是MCI和AD的诊断、鉴别诊断和疾病监测的有用工具.

  3. A nuclear magnetic resonance study of water in aggrecan solutions

    Foster, Richard J.; Damion, Robin A.; Baboolal, Thomas G.; Smye, Stephen W.; Ries, Michael E.

    2016-01-01

    Aggrecan, a highly charged macromolecule found in articular cartilage, was investigated in aqueous salt solutions with proton nuclear magnetic resonance. The longitudinal and transverse relaxation rates were determined at two different field strengths, 9.4 T and 0.5 T, for a range of temperatures and aggrecan concentrations. The diffusion coefficients of the water molecules were also measured as a function of temperature and aggrecan concentration, using a pulsed field gradient technique at 9.4 T. Assuming an Arrhenius relationship, the activation energies for the various relaxation processes and the translational motion of the water molecules were determined from temperature dependencies as a function of aggrecan concentration in the range 0–5.3% w/w. The longitudinal relaxation rate and inverse diffusion coefficient were approximately equally dependent on concentration and only increased by upto 20% from that of the salt solution. The transverse relaxation rate at high field demonstrated greatest concentration dependence, changing by an order of magnitude across the concentration range examined. We attribute this primarily to chemical exchange. Activation energies appeared to be approximately independent of aggrecan concentration, except for that of the low-field transverse relaxation rate, which decreased with concentration. PMID:27069663

  4. Work in progress: nuclear magnetic resonance imaging of the gallbladder

    A preliminary study of the relation between food intake and intensity of gallbladder bile on nuclear magnetic resonance (NMR) images was made. Twelve subjects (seven volunteers, five patients) were imaged following a minimum of 14 hours of fasting. Six of seven volunteers were reimaged one hour after stimulation by either a fatty meal or an alcoholic beverage. An additional seven patients were imaged two hours after a hospital breakfast. It was found that concentrated bile emits a high-intensity spin echo signal (SE), while hepatic bile in the gallbladder produces a low-intensity SE signal. Following ingestion of cholecystogogue, dilute hepatic bile settles on top of the concentrated bile, each emitting SE signals of different intensity. The average T1 value of concentrated bile was 594 msec, while the T1 vaue of dilute hepatic bile was 2,646 msec. The average T2 values were 104 msec for concentrated bile and 126 msec for dilute bile. The most likely cause for the different SE intensities of bile is the higher water content, and therefore longer T1 or T2 relaxation times, of hepatic bile. It is suggested that NMR imaging has the ability to provide physiological information about the gallbladder and that it may prove to be a simple and safe clinical test of gallbladder function

  5. Discrete decoding based ultrafast multidimensional nuclear magnetic resonance spectroscopy

    The three-dimensional (3D) nuclear magnetic resonance (NMR) spectroscopy constitutes an important and powerful tool in analyzing chemical and biological systems. However, the abundant 3D information arrives at the expense of long acquisition times lasting hours or even days. Therefore, there has been a continuous interest in developing techniques to accelerate recordings of 3D NMR spectra, among which the ultrafast spatiotemporal encoding technique supplies impressive acquisition speed by compressing a multidimensional spectrum in a single scan. However, it tends to suffer from tradeoffs among spectral widths in different dimensions, which deteriorates in cases of NMR spectroscopy with more dimensions. In this study, the discrete decoding is proposed to liberate the ultrafast technique from tradeoffs among spectral widths in different dimensions by focusing decoding on signal-bearing sites. For verifying its feasibility and effectiveness, we utilized the method to generate two different types of 3D spectra. The proposed method is also applicable to cases with more than three dimensions, which, based on the experimental results, may widen applications of the ultrafast technique

  6. Measurement of total lung water from nuclear magnetic resonance images

    Nuclear magnetic resonance (NMR) spectroscopy was used to show that the water content of lung tissue could be predicted accurately from the intensity of signal resulting from a 900 saturation recovery sequence. The water contained in an image section may, therefore, be calculated by reference to a 100% water standard. Lung water was obtained by imaging the lung in continuous sections and summing the water contents of the component sections. The method performed well when applied to a sponge phantom, but underestimated by up to 30% in excised sheep lung. The total (vascular and extravascular) pulmonary water measured by NMR in six healthy volunteers was 292 g (SD 58 g) or 4.6 g/kg body weight, less than predicted by some other indirect methods and post-mortem values. A briefer examination comprising two axial sections at standardised levels was also devised. In 15 healthy volunteers the mean water content of a 1.6 cm-thick axial section through the right lung was 17.8 g at the sternal angle, and 23.3 g 5 cm caudally. In the left lung, the values were 16.4 g and 16.3 g, respectively. (author)

  7. Discrete decoding based ultrafast multidimensional nuclear magnetic resonance spectroscopy

    Wei, Zhiliang; Lin, Liangjie; Ye, Qimiao; Li, Jing; Cai, Shuhui; Chen, Zhong

    2015-07-01

    The three-dimensional (3D) nuclear magnetic resonance (NMR) spectroscopy constitutes an important and powerful tool in analyzing chemical and biological systems. However, the abundant 3D information arrives at the expense of long acquisition times lasting hours or even days. Therefore, there has been a continuous interest in developing techniques to accelerate recordings of 3D NMR spectra, among which the ultrafast spatiotemporal encoding technique supplies impressive acquisition speed by compressing a multidimensional spectrum in a single scan. However, it tends to suffer from tradeoffs among spectral widths in different dimensions, which deteriorates in cases of NMR spectroscopy with more dimensions. In this study, the discrete decoding is proposed to liberate the ultrafast technique from tradeoffs among spectral widths in different dimensions by focusing decoding on signal-bearing sites. For verifying its feasibility and effectiveness, we utilized the method to generate two different types of 3D spectra. The proposed method is also applicable to cases with more than three dimensions, which, based on the experimental results, may widen applications of the ultrafast technique.

  8. Multinuclear nuclear magnetic resonance spectroscopic study of cartilage proteoglycans

    Hyaline cartilage is a composite material whose major function is to withstand compression while retaining flexibility. Its mechanical properties are affected by tissue hydration and ionic composition. Models of the mechanical behavior of cartilage have incorporated certain assumptions about the interactions of the major components of cartilage: collagen, proteoglycans, water, and cations. To determine the validity of these assumption, the authors have used nuclear magnetic resonance spectroscopy (NMR). Two approaches have been used: (a) natural abundance carbon-13 NMR; and (b) NMR of sodium-23, potassium-39, magnesium-25, and calcium-43. Evidence from studies in intact tissues are reinforced by extensive measurements on solutions of proteoglycans and other relevant macromolecules. Based on the measurements of NMR relaxation rates and lineshapes reported here, it is concluded that neither sodium nor potassium interact strongly with bovine nasal proteoglycan aggregates or their substituent glycosaminoglycan chains in solution. Proteoglycans do bind magnesium and calcium. Therefore there is a qualitative difference between monovalent and divalent cations, which is not taken into account by polyelectrolyte models or models for the ionic dependence of mechanical properties. Cation binding to heparin, which has a higher charge density than cartilage proteoglycans, was also studied. The results presented here establish that heparin binds sodium, magnesium, and calcium

  9. Nuclear magnetic resonance metabonomics: methods for drug discovery and development.

    Ott, Karl-Heinz; Aranibar, Nelly

    2007-01-01

    Nuclear magnetic resonance (NMR)-based metabonomics is gaining popularity in drug discovery and development and in academia in a variety of settings, ranging from toxicology, preclinical, and clinical approaches to nutrition research, studies on microorganisms, and research on plants. This chapter focuses on the basic steps in a metabonomics study and emphasizes experience and lessons learned in our lab where we focused on metabonomic analyses of plant extracts, cell lines, and a variety of animal tissues and biofluids. We emphasize that a comprehensive and suitable study design is pivotal for a correct biological interpretation of the results, as well as highly controlled experimental conditions. Sample preparation and NMR protocols are detailed for a wide range of sample types. We discuss alternative data processing strategies and considerations for a general data analysis approach, paying particular attention to the statistical interpretation and validation of the results while also highlighting approaches to avoid possible pitfalls resulting from systematic and random errors. A tutorial written for the R statistical package and other small utilities are available from the authors upon request. PMID:17035690

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

    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. PMID:23733702

  11. Cardiac energy metabolism probed with nuclear magnetic resonance. Chapter 12

    Nuclear magnetic resonance (NMR) spectroscopy possesses great potential for studying myocardial energy metabolism. To ensure that the observed NMR signal predominantly originates from the heart, localization is required, which can be achieved by excision or exposure of the heart, or by means of sophisticated NMR localization techniques. A number of different atomic nuclei have been employed. H-1 NMR has been mainly used to follow lactate accumulation is ischemic or anoxic hearts. C-13 NMR has been applied to study the fate of different substrates in the citric acid cycle and amino acid pools, and the role of glycogen metabolism in ischemia or anoxia. F-19, Na-23 and K-39 have been employed to investigate the consequences of altered energy metabolism for myocardial intracellular concentrations of Ca2+, Na+ and K+. The most abundantly used nucleus for studying myocardial energy metabolism is P-31. Numerous contributions have been made to the investigation of ischemia and reperfusion, protection of the heart against the consequences of ischemia and reperfusion, contractile failure, variation of high-energy phosphate levels over the cardiac cycle, regulation of oxidative phosphorylation and intracellular enzyme kinetics of both isolated perfused hearts and hearts in situ. Even human myocardial metabolism can be assessed by P-31 NMR, which is on the verge of becoming a clinical tool for investigating heart disease. 106 refs.; 3 figs.; 1 table

  12. Distinguishing Carbonate Reservoir Pore Facies with Nuclear Magnetic Resonance Measurements

    Characterization of carbonate rocks may involve identifying the important pore types which are present. In the past, this task has required detailed petrographic analysis of many core samples. Here, we describe a method which uses nuclear magnetic resonance (NMR) measurements to reduce the amount of petrographic analysis needed for porosity typing of carbonate reservoir rocks.For a rock sample which has been measured with NMR, our method decomposes the log(T2) spectrum into at most three Gaussian-shaped components and gives a set of nine parameters. Two characteristic quantities having geological significance are extracted from the nine parameters. Values of the two quantities are compared with a reference set, established from samples having both NMR and petrographic evaluations of porosity types. We use a Bayesian approach to the classification of the dominant porosity type.Tests of our method on 103 samples show a correct prediction in 60 to 90 percent of the samples. The lower success rate was obtained for samples with five porosity types from three fields; the higher success rate obtained with samples with three porosity types from one well. The use of geologically significant quantities extracted from the decomposition gives comparable success rate to those obtained using a standard, non-geological approach such as canonical variates

  13. Synthesis and physical studies of thiophospholipids using nuclear magnetic resonance

    1,2-Dipalmitoyl-sn-glycero-3-thiophosphocholine, DPPsC, and 1,2-dipalmitoyl-sn-glycero-3-thiophospho-L-serine, DPPsS, were synthesized and used to probe bilayer structural properties and enzymatic stereoselectivity. Using resolved diastereomers of DPPsC, the effect of a chiral phosphorus center on the thermotropic properties of lipid dispersions was probed. 31P and 2H nuclear magnetic resonance, NMR, were utilized to confirm the thermotropic phase assignments for DPPsC diastereomers observed by differential scanning calorimetry. 31P NMR of the thiophosphate analogs revealed a more rigid subgel and Lβ' gel phase than DPPC, in regard to the phosphate rotational motion. In the Pβ' gel phase, the degree of motion of Sp and (Rp+Sp) was similar to DPPC. The tiophosphate analogs in the liquid crystalline phase experienced a freer rotational environment compared to DPPC. 2H NMR was performed on DPPsC diastereomers deuterated at the three choline carbons, α, β, γ. The liquid crystalline phase was used to detect differences between the diastereomers along the choline moiety. The diastereomeric mixture of DPPsS was used as a substrate for two stereoselective enzymes, phospholipases A2 and C. Phospholipase A2 hydrolyzed (Rp)-DPPsS, while no apparent reaction was detected for the hydrolysis of (Sp)-DPPsS with phospholipase C

  14. Determination of reservoir effective porosity using nuclear magnetic logging data

    In connection with the development of nuclear magnetic logging (NML) the possibility has occurred to determine the effective porosity coefficient for rocks directly under the conditions of their occurrence. The initial amplitude of a signal of free precession of NML is proportional to the quantity of free fluid in the rock volume, which is determined by the index of free fluid (IFF). On the basis of the laboratory studies it is shown that the relation between IFF and free water content is always linear and doesn't depend on lithological characteristics of rocks, porous dimensions and distribution. Using this relation it's possible to estimate bound water content. While filling the reservoir with weakly mineralized water the IFF value coincides numerically with the effective porosity coefficient. Otherwise the content of hydrogen nuclei in a volume unit is much less; while calculating the effective porosity coefficient this fact is recorded by the index of the amplitude decrease which depends on temperature and increases with its growth (for oils). In strata containing intercalations of reservoirs and non-reservoirs the averaged according to stratum IFF value determines the mean-weighted values of effective porosity

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

    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.

  16. Two-dimensional nuclear magnetic resonance of quadrupolar systems

    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.

  17. Some concepts of the advanced mass spectrometry at the COMBAS magnetic separator of nuclear reaction products

    Proposed is an in-flight measurement method of recoil nuclei masses with the help of a Penning trap located behind the COMBAS magnetic separator for nuclear reaction products. The method is based on the following operations: (i) Accepting the recoil nuclear reaction products by the magnetic separator and decreasing their kinetic energy by degraders. (ii) In-flight transportation of the retarded nuclei into the magnetic field of the Penning trap's solenoid and transforming their remaining longitudinal momentum into orbital rotation by the fringing magnetic field of the solenoid. (iii) Cooling the orbital rotation of the ions by the high-frequency azimuthal electric field of the Penning trap's electric hyperboloid. (orig.)

  18. Synthesis and GIAO NMR Calculations for Some Novel 4-Heteroarylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-one Derivatives: Comparison of Theoretical and Experimental 1Hand 13C- Chemical Shifts

    Haci Baykara

    2005-08-01

    Full Text Available Abstract: 3-Alkyl(aryl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1 reacted with 5-methylfuran-2-carboxyaldehyde to afford the corresponding 3-alkyl(aryl-4-(5-methyl-2-furylmethylenamino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2. Four newly synthesized compounds have been characterized by elemental analyses, IR, 1H-NMR, 13C-NMR and UV spectral data. In addition, isotropic 1H- and 13C-nuclear magnetic shielding constants of compounds 3 were calculated by employing the direct implementation of the gaugeincluding-atomic-orbital (GIAO method at the B3LYP density functional and HF levels of the theory. The geometry of each compound has been optimized using a 6-311G basis set. Nuclear shielding constants were also calculated by using 6-311G basis set. Theoretical values are compared to the experimental data.

  19. Scaling of transverse nuclear magnetic relaxation due to magnetic nanoparticle aggregation

    Brown, Keith A. [Harvard School of Engineering and Applied Science, 29 Oxford Street, Cambridge, MA 02138 (United States); Vassiliou, Christophoros C. [Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Issadore, David; Berezovsky, Jesse [Harvard School of Engineering and Applied Science, 29 Oxford Street, Cambridge, MA 02138 (United States); Cima, Michael J. [Massachusetts Institute of Technology, Department of Materials Science and Engineering and Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue Cambridge, MA 02139 (United States); Westervelt, R.M., E-mail: westervelt@seas.harvard.ed [Harvard School of Engineering and Applied Science, 29 Oxford Street, Cambridge, MA 02138 (United States); Harvard University, Department of Physics, 17 Oxford Street, Cambridge, MA 02138 (United States)

    2010-10-15

    The aggregation of superparamagnetic iron oxide (SPIO) nanoparticles decreases the transverse nuclear magnetic resonance (NMR) relaxation time T{sub 2}{sup CP} of adjacent water molecules measured by a Carr-Purcell-Meiboom-Gill (CPMG) pulse-echo sequence. This effect is commonly used to measure the concentrations of a variety of small molecules. We perform extensive Monte Carlo simulations of water diffusing around SPIO nanoparticle aggregates to determine the relationship between T{sub 2}{sup CP} and details of the aggregate. We find that in the motional averaging regime T{sub 2}{sup CP} scales as a power law with the number N of nanoparticles in an aggregate. The specific scaling is dependent on the fractal dimension d of the aggregates. We find T{sub 2}{sup CP{proportional_to}{Nu}-0.44} for aggregates with d=2.2, a value typical of diffusion limited aggregation. We also find that in two-nanoparticle systems, T{sub 2}{sup CP} is strongly dependent on the orientation of the two nanoparticles relative to the external magnetic field, which implies that it may be possible to sense the orientation of a two-nanoparticle aggregate. To optimize the sensitivity of SPIO nanoparticle sensors, we propose that it is best to have aggregates with few nanoparticles, close together, measured with long pulse-echo times.

  20. Scaling of transverse nuclear magnetic relaxation due to magnetic nanoparticle aggregation.

    Brown, Keith A; Vassiliou, Christophoros C; Issadore, David; Berezovsky, Jesse; Cima, Michael J; Westervelt, R M

    2010-10-01

    The aggregation of superparamagnetic iron oxide (SPIO) nanoparticles decreases the transverse nuclear magnetic resonance (NMR) relaxation time T2CP of adjacent water molecules measured by a Carr-Purcell-Meiboom-Gill (CPMG) pulse-echo sequence. This effect is commonly used to measure the concentrations of a variety of small molecules. We perform extensive Monte Carlo simulations of water diffusing around SPIO nanoparticle aggregates to determine the relationship between T2CP and details of the aggregate. We find that in the motional averaging regime T2CP scales as a power law with the number N of nanoparticles in an aggregate. The specific scaling is dependent on the fractal dimension d of the aggregates. We find T2CP∝N-0.44 for aggregates with d = 2.2, a value typical of diffusion limited aggregation. We also find that in two-nanoparticle systems, T2CP is strongly dependent on the orientation of the two nanoparticles relative to the external magnetic field, which implies that it may be possible to sense the orientation of a two-nanoparticle aggregate. To optimize the sensitivity of SPIO nanoparticle sensors, we propose that it is best to have aggregates with few nanoparticles, close together, measured with long pulse-echo times. PMID:20689678

  1. Magnetic resonance imaging and nuclear magnetic resonance investigations of bentonite systems

    This report summarizes results from a set of magnetic resonance imaging (MRI) and nuclear magnetic resonance (NMR) experiments performed on Ca and Na montmorillonite samples interacting with water. The primary goal with these studies was to provide, in a non-invasive manner, a quantitative measure of bentonite distribution in extended samples during and after different physical processes such as swelling and sedimentation and on the time scale from minutes to years. Additionally, we also studied the distribution of foreign particles (such as native minerals as well as magnetic model particles) within bentonite systems and performed some diffusion NMR experiments with the aim of characterizing the state of colloids that form after clay dissolution. Both natural montmorillonites and purified and ion-exchanged montmorillonite clays were investigated. The primary variables were clay composition and water ionic strength. Bulk samples confined in a vertical tube and in a horizontal channel were investigated. A critical issue for the stability of clay buffer layer in deep underground repository is to prevent or minimize the release of clay particles into the water phase. In our experiments, the most significant particle losses were found for Na-MX80 clay exposed to water with low ionic strength. With increasing the concentration of CaCl2 in the water phase both swelling and particle release are slowed down but not completely eliminated due probably to gradual change of water ion content via ion exchange with the clay itself. For natural MX80 samples, in spite of significant swelling expansion, no clay particle release above the sensitivity limit of 0.001 volume% was observed. Ca-MX80 exhibited the smallest expansion and no trace of clay particle released into the aqueous phase

  2. Applications of 1H-NMR relaxometry in experimental liver studies

    Purpose of this study was to investigate applications of proton nuclear magnetic resonance (1H-NMR) relaxometry in experimental medicine. Relaxometry was performed by measurements of spin-lattice (T1) and spin-spin (T2) relaxation time parameters on liver biopsies up to four hours after biopsy excision. Variations of relaxation times due to species and strain, different sample handling and different liver damage models, ethionine fatty liver and paracetamol liver necrosis, were investigated. Cell integrity effects were studied on homogenized liver samples. Relaxation time parameters, especially 'main' components T1A and T2A of biexponential model fit, were identified to react very sensitive after tissue damages as well as to cell viability. Thus, investigation of stored liver grafts was performed in order to evaluate the possibility of a rapid liver graft viability testing method for human liver transplantation surgery by 1H-NMR relaxometry. Another series of measurements was performed to investigate the applicability of isoflurane anesthesia for in vivo NMR experiments. This study proved the good appropriateness of isoflurane for that purpose provided that physiological monitoring and individual adjustment of anesthesia are performed. In these investigations it could be revealed that mainly T1A and T2A are influenced by tissue condition and that different information is inherent in these two parameters, with T2A reflecting tissue viability and changes of tissue conditions very sensitively but rather unspecifically in respect to the damage applied. Based on these results the following future applications of 1H-NMR relaxometry are suggested : (1) model investigations, (2) investigation of given pathologies, (3) investigation of basic requirements for in vivo NMR and (4) application in a liver graft viability testing protocol, which seems to be the most important future application of 1H-NMR relaxometry in medicine. (author)

  3. Application of 1H-NMR metabolomic profiling for reef-building corals.

    Emilia M Sogin

    Full Text Available In light of global reef decline new methods to accurately, cheaply, and quickly evaluate coral metabolic states are needed to assess reef health. Metabolomic profiling can describe the response of individuals to disturbance (i.e., shifts in environmental conditions across biological models and is a powerful approach for characterizing and comparing coral metabolism. For the first time, we assess the utility of a proton-nuclear magnetic resonance spectroscopy (1H-NMR-based metabolomics approach in characterizing coral metabolite profiles by 1 investigating technical, intra-, and inter-sample variation, 2 evaluating the ability to recover targeted metabolite spikes, and 3 assessing the potential for this method to differentiate among coral species. Our results indicate 1H-NMR profiling of Porites compressa corals is highly reproducible and exhibits low levels of variability within and among colonies. The spiking experiments validate the sensitivity of our methods and showcase the capacity of orthogonal partial least squares discriminate analysis (OPLS-DA to distinguish between profiles spiked with varying metabolite concentrations (0 mM, 0.1 mM, and 10 mM. Finally, 1H-NMR metabolomics coupled with OPLS-DA, revealed species-specific patterns in metabolite profiles among four reef-building corals (Pocillopora damicornis, Porites lobata, Montipora aequituberculata, and Seriatopora hystrix. Collectively, these data indicate that 1H-NMR metabolomic techniques can profile reef-building coral metabolomes and have the potential to provide an integrated picture of the coral phenotype in response to environmental change.

  4. Application of 1H-NMR Metabolomic Profiling for Reef-Building Corals

    Sogin, Emilia M.; Anderson, Paul; Williams, Philip; Chen, Chii-Shiarng; Gates, Ruth D.

    2014-01-01

    In light of global reef decline new methods to accurately, cheaply, and quickly evaluate coral metabolic states are needed to assess reef health. Metabolomic profiling can describe the response of individuals to disturbance (i.e., shifts in environmental conditions) across biological models and is a powerful approach for characterizing and comparing coral metabolism. For the first time, we assess the utility of a proton-nuclear magnetic resonance spectroscopy (1H-NMR)-based metabolomics approach in characterizing coral metabolite profiles by 1) investigating technical, intra-, and inter-sample variation, 2) evaluating the ability to recover targeted metabolite spikes, and 3) assessing the potential for this method to differentiate among coral species. Our results indicate 1H-NMR profiling of Porites compressa corals is highly reproducible and exhibits low levels of variability within and among colonies. The spiking experiments validate the sensitivity of our methods and showcase the capacity of orthogonal partial least squares discriminate analysis (OPLS-DA) to distinguish between profiles spiked with varying metabolite concentrations (0 mM, 0.1 mM, and 10 mM). Finally, 1H-NMR metabolomics coupled with OPLS-DA, revealed species-specific patterns in metabolite profiles among four reef-building corals (Pocillopora damicornis, Porites lobata, Montipora aequituberculata, and Seriatopora hystrix). Collectively, these data indicate that 1H-NMR metabolomic techniques can profile reef-building coral metabolomes and have the potential to provide an integrated picture of the coral phenotype in response to environmental change. PMID:25354140

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

    Goodson, Boyd M.

    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.

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

    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

  7. Nuclear magnetic resonance data of C8H10N4O2

    Jain, M.

    This document is part of Subvolume C `Chemical Shifts and Coupling Constants for Hydrogen-1, Heterocycles' of Landolt-Börnstein III/40 `Nuclear Magnetic Resonance Data', Group III `Condensed Matter'.

  8. Methodology for nuclear magnetic resonance and ion cyclotron resonance mass spectrometry

    This thesis encompasses methodological developments in both nuclear magnetic resonance and Fourier transform ion cyclotron resonance mass spectrometry. The NMR section explores the effects of scalar relaxation on a coupled nucleus to measure fast exchange rates. In order to quantify these rates accurately, a precise knowledge of the chemical shifts of the labile protons and of the scalar couplings is normally required. We applied the method to histidine where no such information was available a priori, neither about the proton chemical shifts nor about the one-bond scalar coupling constants J(1H15N), since the protons were invisible due to fast exchange. We have measured the exchange rates of the protons of the imidazole ring and of amino protons in histidine by indirect detection via 15N. Not only the exchange rate constants, but also the elusive chemical shifts of the protons and the coupling constants could be determined. For the mass spectrometry section, the ion isolation project was initiated to study the effect of phase change of radiofrequency pulses. Excitation of ions in the ICR cell is a linear process, so that the pulse voltage required for ejecting ions must be inversely proportional to the pulse duration. A continuous sweep pulse propels the ion to a higher radius, whereas a phase reversal causes the ion to come to the centre. This represents the principle of 'notch ejection', wherein the ion for which the phase is reversed is retained in the ICR cell, while the remaining ions are ejected. The manuscript also contains a theoretical chapter, wherein the ion trajectories are plotted by solving the Lorentzian equation for the three-pulse scheme used for two-dimensional ICR. Through our simulations we mapped the ion trajectories for different pulse durations and for different phase relations. (author)

  9. Three dimensional nuclear magnetic resonance spectroscopic imaging of sodium ions using stochastic excitation and oscillating gradients

    Frederick, B.deB. [California Univ., Berkeley, CA (United States)]|[Lawrence Berkeley Lab., CA (United States)

    1994-12-01

    Nuclear magnetic resonance (NMR) spectroscopic imaging of {sup 23}Na holds promise as a non-invasive method of mapping Na{sup +} distributions, and for differentiating pools of Na{sup +} ions in biological tissues. However, due to NMR relaxation properties of {sup 23}Na in vivo, a large fraction of Na{sup +} is not visible with conventional NMR imaging methods. An alternate imaging method, based on stochastic excitation and oscillating gradients, has been developed which is well adapted to measuring nuclei with short T{sub 2}. Contemporary NMR imaging techniques have dead times of up to several hundred microseconds between excitation and sampling, comparable to the shortest in vivo {sup 23}Na T{sub 2} values, causing significant signal loss. An imaging strategy based on stochastic excitation has been developed which greatly reduces experiment dead time by reducing peak radiofrequency (RF) excitation power and using a novel RF circuit to speed probe recovery. Continuously oscillating gradients are used to eliminate transient eddy currents. Stochastic {sup 1}H and {sup 23}Na spectroscopic imaging experiments have been performed on a small animal system with dead times as low as 25{mu}s, permitting spectroscopic imaging with 100% visibility in vivo. As an additional benefit, the encoding time for a 32x32x32 spectroscopic image is under 30 seconds. The development and analysis of stochastic NMR imaging has been hampered by limitations of the existing phase demodulation reconstruction technique. Three dimensional imaging was impractical due to reconstruction time, and design and analysis of proposed experiments was limited by the mathematical intractability of the reconstruction method. A new reconstruction method for stochastic NMR based on Fourier interpolation has been formulated combining the advantage of a several hundredfold reduction in reconstruction time with a straightforward mathematical form.

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

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

  11. Energetics of endurance exercise in young horses determined by nuclear magnetic resonance metabolomics

    Margaux Marie-Hélène, Olivia Luck

    2015-07-01

    Full Text Available Long-term endurance exercise severely affects metabolism in both human and animal athletes resulting in serious risk of metabolic disorders during or after competition. Young horses (up to 6 years old can compete in races up to 90 km despite limited scientific knowledge of energetic metabolism responses to long distance exercise in these animals. The hypothesis of this study was that there would be a strong effect of endurance exercise on the metabolomic profiles of young horses and that the energetic metabolism response in young horses would be different from that of more experienced horses. Metabolomic profiling is a powerful method that combines Nuclear magnetic resonance (NMR spectrometry with supervised orthogonal projection on latent structure (OPLS statistical analysis. 1H-NMR spectra were obtained from plasma samples drawn from young horses (before and after competition. The spectra obtained before and after the race from the same horse (92 samples were compared using OPLS. The statistical parameters showed the robustness of the model (R2Y=0.947, Q2Y=0.856 and CV-ANOVA p-value < 0.001. For confirmation of the predictive value of the model, a test set of 104 sample spectra were projected by the model, which provided perfect predictions as the area under the receiving-operator curve was 1. The metabolomic profile determined with the OPLS model showed that glycemia after the race was lower than glycemia before the race, despite the involvement of lipid and protein catabolism. An OPLS model was calculated to compare spectra obtained on plasma taken after the race from 6-year-old horses and from experienced horses (cross-validated ANOVA p-value < 0.001. The comparison of metabolomic profiles in young horses to those from experienced horses showed that experienced horses maintained their glycemia with higher levels of lactate and a decrease of plasma lipids after the race.

  12. Three dimensional nuclear magnetic resonance spectroscopic imaging of sodium ions using stochastic excitation and oscillating gradients

    Nuclear magnetic resonance (NMR) spectroscopic imaging of 23Na holds promise as a non-invasive method of mapping Na+ distributions, and for differentiating pools of Na+ ions in biological tissues. However, due to NMR relaxation properties of 23Na in vivo, a large fraction of Na+ is not visible with conventional NMR imaging methods. An alternate imaging method, based on stochastic excitation and oscillating gradients, has been developed which is well adapted to measuring nuclei with short T2. Contemporary NMR imaging techniques have dead times of up to several hundred microseconds between excitation and sampling, comparable to the shortest in vivo 23Na T2 values, causing significant signal loss. An imaging strategy based on stochastic excitation has been developed which greatly reduces experiment dead time by reducing peak radiofrequency (RF) excitation power and using a novel RF circuit to speed probe recovery. Continuously oscillating gradients are used to eliminate transient eddy currents. Stochastic 1H and 23Na spectroscopic imaging experiments have been performed on a small animal system with dead times as low as 25μs, permitting spectroscopic imaging with 100% visibility in vivo. As an additional benefit, the encoding time for a 32x32x32 spectroscopic image is under 30 seconds. The development and analysis of stochastic NMR imaging has been hampered by limitations of the existing phase demodulation reconstruction technique. Three dimensional imaging was impractical due to reconstruction time, and design and analysis of proposed experiments was limited by the mathematical intractability of the reconstruction method. A new reconstruction method for stochastic NMR based on Fourier interpolation has been formulated combining the advantage of a several hundredfold reduction in reconstruction time with a straightforward mathematical form

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

    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.

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

    Afanasjev, A. V.; Ring, P.

    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 effecti...

  15. Nuclear Spin Maser at Highly Stabilized Low Magnetic Field and Search for Atomic EDM

    A nuclear spin maser is operated at a low static field through an active feedback scheme based on an optical nuclear spin detection and succeeding spin control by a transverse field application. The frequency stability of this optical-coupling spin maser is improved by installation of a low-noise current source for a solenoid magnet producing a static magnetic field in the maser operation. Experimental devices for application of the maser to EDM experiment are being developed.

  16. Nuclear and magnetic structures of nonpolar ferrofluids by small-angle neutron scattering

    Small-angle scattering of nonpolarized and polarized neutrons has proved to be a powerful technique for studying features of nuclear and magnetic structures of ferrofluids at nanoscale. The paper presents our recent results on application of the technique for comparative analysis of nonpolar ferrofluids (d-cyclohexane) stabilized by different surfactants, which are oleic and myristic acids. Qualitative difference both in nuclear and magnetic structural organization is observed and discussed

  17. Effect of rootstock on the scion of Hevea brasiliensis through metabolic analysis of latex samples by 1H NMR

    Eduardo Sanches Pereira do Nascimento

    2011-01-01

    Full Text Available In this study, the effect of rootstock on grafting through metabolomic analysis of latex (Hevea brasiliensis samples was verified by 1H nuclear magnetic resonance (NMR and multivariate data analysis. Sixteen metabolites present in the latex cytosol were characterized by NMR. PCA analysis showed that the latex samples of the RR and GR groups can be differentiated. The GR group samples present a metabolic profile similar to the RR group samples, while the RG group is in an intermediate position between RR and GG groups. Sucrose and formate contributed greatly to the separation obtained by PCA, presenting a good correlation between the results. 1H NMR was an efficient technique to differentiate latex samples from different types of rootstocks and grafting and in the future could be used to predict rubber production by latex analysis.

  18. A study by (1)H NMR on the influence of some factors affecting lipid in vitro digestion.

    Nieva-Echevarría, Bárbara; Goicoechea, Encarnación; Manzanos, María J; Guillén, María D

    2016-11-15

    This article focuses on the impact of several experimental factors, including gastric acidification, intestinal transit time, presence of gastric lipase, sample/digestive fluids ratio, concentration and nature of the enzymes in intestinal juice, and bile concentration, on the extent of in vitro lipolysis when using a static model that simulates human digestion processes in mouth, stomach and small intestine. The study was carried out by Proton Nuclear Magnetic Resonance ((1)H NMR). This technique provides a complete molecular picture of lipolysis, evidencing for the first time, whether preferential hydrolysis of certain glycerides over others occurs. A lipolysis degree similar to that reported in vivo was reached by varying certain variables within a physiological range; among them, bile concentration was found to be crucial. The holistic view of this (1)H NMR study provides information of paramount importance to design sound in vitro digestion models to determine the bioaccessibility and bioavailability of lipophilic compounds. PMID:27283602

  19. Science and history explored by nuclear magnetic resonance

    Nuclear Magnetic Resonance was chosen as the main tool for investigating different biological and chemical systems, as it is unique in providing the information details about the morphology and molecular structures and conformations by which the fundamental properties of these biological and chemical systems can be understood. Proton spin-diffusion experiments combined with 13C CPMAS spectroscopy were successfully applied to characterize the changes that occur during the thermal denaturation of keratin fibers from wool and hair. A model describing both the effect of thermal denaturation and the effect of different chemical treatments on keratin fibers is presented. Proton NMR spectroscopy was used for studying the proton exchange in Sulfonated Polyether Ether Ketone proton exchange membranes revealing that the water exchange processes in hydrated SPEEK-silica membranes are more efficient when low concentrations of polyethoxysiloxane (PEOS) are used for the membrane preparation. Proton 1D exchange spectroscopy combined with transverse relaxation measurements offered good insight in the state of water in hydrated SPEEK/SiO2 membranes revealing that concentrations of 5%-10% wt. PEOS could enhance the electrical conductivity of PEM. Hyperpolarized 129Xe NMR spectroscopy was successfully applied for monitoring the free radical polymerization reactions of methyl methacrylate, methyl acrylate and the copolymerization of methyl methacrylate and methyl acrylate. The observation of Xe chemical shift and linewidths during the reactions reveal information about the polymer chain growths during the polymerizations. The successful application of the NMR-MOUSE to visualise the different anatomical layers with varying proton densities opens the possibility of its use in clinical studies such as osteoporosis for bone density measurements. The NMR-MOUSE was also successfully applied for the analysis of violins and bows and a classification of the violins and bows as a function of

  20. Nuclear magnetic resonance studies of macroscopic morphology and dynamics

    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

  1. Nuclear magnetic resonance studies of macroscopic morphology and dynamics

    Barrall, G A [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.

  2. Resolution Improvement in Multidimensional Nuclear Magnetic Resonance Spectroscopy of Proteins

    The work presented in this thesis is concerned with both liquid-state and solid-state nuclear magnetic resonance (NMR) spectroscopy. Most of this work is devoted to the investigation by solid-state NMR of C13-enriched compounds with the principal aim of presenting techniques devised for further improving the spectral resolution in multidimensional NMR of microcrystalline proteins. In fully C13-labelled compounds, the J-coupling induces a broadening of the carbon lineshapes. We show that spin-state-selective technique called IPAP can be successfully combined with standard polarisation transfer schemes in order to remove the J-broadening in multidimensional solid-state NMR correlation experiments of fully C13-enriched proteins. We present subsequently two techniques tailored for liquid-state NMR spectroscopy. The carbon directly detected techniques provide chemical shift information for all backbone hetero-nuclei. They are very attracting for the study of large bio-molecular systems or for the investigation of paramagnetic proteins. In the last part of this thesis, we study the spin-echo J-modulation for homonuclear two-spin 1/2 systems. Under magic-angle spinning, the theory of J-induced spin-echo modulation allows to derive a set of modulation regimes which give a spin-echo modulation exactly equal to the J-coupling. We show that the chemical-shift anisotropy and the dipolar interaction tend to stabilize the spin-echo J-modulation. The theoretical conclusions are supported by numerical simulations and experimental results obtained for three representative samples containing C13 spin pairs. (author)

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

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

    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 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. PMID:27294925

  4. Dynamic stereochemistry of erigeroside by measurement of 1H- 1H and 13C- 1H coupling constants

    Tafazzoli, Mohsen; Ghiasi, Mina; Moridi, Mahdi

    2008-07-01

    Erigeroside was extracted from Satureja khuzistanica Jamzad (Marzeh Khuzistani in Persian, family of lamiaceae), and 1H, 13C, 13C{ 1H}, 1H- 1H COSY, HMQC and J-HMBC were obtained to identify this compound and determine a complete set of J-coupling constants ( 1JC-H, 2JC-H, 3JC-H and 3JH-H) values within the exocyclic hydroxymethyl group (CH 2OH) and anomeric center. In parallel, density functional theory (DFT) using B3LYP functional and split-valance 6-311++G** basis set has been used to optimized the structures and conformers of erigeroside. In all calculations solvent effects were considered using a polarized continuum (overlapping spheres) model (PCM). The dependencies of 1J, 2J and 3J involving 1H and 13C on the C 5'-C 6' ( ω), C 6'-O 6' ( θ) and C 1'-O 1' ( φ) torsion angles in erigeroside were computed using DFT method. Complete hyper surfaces for 1JC1',H1', 2JC5',H6'R, 2JC5',H6'S, 2JC6',H5', 3JC4',H6'R, 3JC4',H6'S and 2JH6'R-H5'S as well as 3JH5',H6'R were obtained and used to derive Karplus equations to correlate these couplings to ω, θ and φ. These calculated J-couplings are in agreement with experimental values. These results confirm the reliability of DFT calculated coupling constants in aqueous solution.

  5. Development and applications of NMR [nuclear magnetic resonance] in low fields and zero field

    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

  6. Nuclear magnetic relaxation and origins of RMN signals from GdAl2

    The intermetallic compound GdAl2 crystallizes in the cubic Laves phase C15. It is a simple ferromagnet below 176K. The easy direction of magnetization in this compound is such that the Al ions are distributed among two magnetically inequivalent sites. The pulsed NMR technique was used to study the origin of the signals from these two sites and the nuclear magnetic relaxation. (author)

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

    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.

  8. Classification of Wines Based on Combination of 1H NMR Spectroscopy and Principal Component Analysis

    DU, Yuan-Yuan; BAI, Guo-Yun; ZHANG, Xu; LIU, Mai-Li

    2007-01-01

    A combination of 1H nuclear magnetic resonance (NMR) spectroscopy and principal component analysis (PCA)has shown the potential for being a useful method for classification of type, production origin or geographic origin of wines. In this preliminary study, twenty-one bottled wines were classified/separated for their location of production in Shacheng, Changli and Yantai, and the types of the blended, medium dry, dry white and dry red wines, using the NMR-PCA method. The wines were produced by three subsidiary companies of an enterprise according to the same national standard. The separation was believed to be mainly due to the fermentation process for different wines and environmental variations, such as local climate, soil, underground water, sunlight and rainfall. The major chemicals associated with the separation were identified.

  9. Nuclear magnetic resonance studies in solid polymeric electrolyte

    Solid complexes formed between Poly (ethylene oxide) and various alkali metal salts, are generally referred to as polymer electrolytes conductivity and NMR properties were investigated in POE - Li Cl sub(7)O sub(4) and POE - Li BF sub(4) complexes. Our sup(1)H, Li and sup(19)F relaxation study suggest that cation motion is controlled by segmental motions of the polymer chain while the anion have additional mobility associated with BG sub(4) rotation. (author)

  10. Neutron Fermi Liquids under the presence of a strong magnetic field with effective nuclear forces

    Perez-Garcia, M Angeles; Polls, A

    2009-01-01

    Landau's Fermi Liquid parameters are calculated for non-superfluid pure neutron matter in the presence of a strong magnetic field at zero temperature. The particle-hole interactions in the system, where a net magnetization may be present, are characterized by these parameters in the framework of a multipolar formalism. We use either zero- or finite-range effective nuclear forces to describe the nuclear interaction. Using the obtained Fermi Liquid parameters, the effect of a strong magnetic field on some bulk magnitudes such as isothermal compressibility and spin susceptibility is also investigated.

  11. No change in N-acetyl aspartate in first episode of moderate depression after antidepressant treatment: 1H magnetic spectroscopy study of left amygdala and left dorsolateral prefrontal cortex

    Bajs Janović M

    2014-09-01

    Full Text Available Maja Bajs Janović,1,3 Petra Kalember,2 Špiro Janović,1,3 Pero Hrabač,2 Petra Folnegović Grošić,1 Vladimir Grošić,4 Marko Radoš,5 Neven Henigsberg2,61University Department of Psychiatry, Clinical Hospital Center Zagreb, Zagreb, 2Polyclinic Neuron, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Zagreb, 3University North, Varaždin, 4Psychiatric Hospital Sveti Ivan, Zagreb, 5University Department of Radiology, Clinical Hospital Center Zagreb, Zagreb, 6Psychiatric Clinic Vrapče, Zagreb, CroatiaBackground: The role of brain metabolites as biological correlates of the intensity, symptoms, and course of major depression has not been determined. It has also been inconclusive whether the change in brain metabolites, measured with proton magnetic spectroscopy, could be correlated with the treatment outcome. Methods: Proton magnetic spectroscopy was performed in 29 participants with a first episode of moderate depression occurring in the left dorsolateral prefrontal cortex and left amygdala at baseline and after 8 weeks of antidepressant treatment with escitalopram. The Montgomery-Asberg Depression Rating Scale, the Hamilton Rating Scale for Depression, and the Beck Depression Inventory were used to assess the intensity of depression at baseline and at the endpoint of the study. At endpoint, the participants were identified as responders (n=17 or nonresponders (n=12 to the antidepressant therapy. Results: There was no significant change in the N-acetyl aspartate/creatine ratio (NAA/Cr after treatment with antidepressant medication. The baseline and endpoint NAA/Cr ratios were not significantly different between the responder and nonresponder groups. The correlation between NAA/Cr and changes in the scores of clinical scales were not significant in either group. Conclusion: This study could not confirm any significant changes in NAA after antidepressant treatment in the first episode of moderate depression, or in

  12. MEMS-Based Force-Detected Nuclear Magnetic Resonance (FDNMR) Spectrometer

    Lee, Choonsup; Butler, Mark C.; Elgammal, Ramez A.; George, Thomas; Hunt, Brian; Weitekamp, Daniel P.

    2006-01-01

    Nuclear Magnetic Resonance (NMR) spectroscopy allows assignment of molecular structure by acquiring the energy spectrum of nuclear spins in a molecule, and by interpreting the symmetry and positions of resonance lines in the spectrum. As such, NMR has become one of the most versatile and ubiquitous spectroscopic methods. Despite these tremendous successes, NMR experiments suffer from inherent low sensitivity due to the relatively low energy of photons in the radio frequency (rt) region of the electromagnetic spectrum. Here, we describe a high-resolution spectroscopy in samples with diameters in the micron range and below. We have reported design and fabrication of force-detected nuclear magnetic resonance (FDNMR).

  13. Neutron experiments on nuclear magnetism in copper and silver. Doctoral thesis

    Tuoriniemi, J.T.

    1995-12-15

    This thesis adds to the series of investigations on nuclear magnetism in metals performed during the past 20 years at the Low Temperature Laboratory of the Helsinki University of Technology. Collective behavior of nuclear spins is expected only at very low temperatures because the mutual interactions are extremely weak. To learn what the spin structure below the transition point in these metals is, neutron-diffraction experiments have been performed. The subject of this thesis is to present the results of neutron experiments on nuclear magnetism in copper and silver.

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

    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.

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

    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.

  16. Nuclear spin magnetic resonance force microscopy using slice modulation

    We report a Boltzmann polarization nuclear spins detection of cycle adiabatic inversion based on resonance slice thickness modulation. The nano-scale localized spin scanning NMRFM is applied using spins locked and anti-locked in the cycling frame. We also create a number of polarization spins among 1012 observing the spin relaxation and dipole-dipole interaction at gradient field 1520 T/m. The changes of nuclear spin signal intensity and relaxation time could be evidence for the nuclear collective excitation and predictions of nuclear spin collective excitation energy

  17. Proton-detected 3D {sup 1}H/{sup 13}C/{sup 1}H correlation experiment for structural analysis in rigid solids under ultrafast-MAS above 60 kHz

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy, E-mail: ramamoor@umich.edu [Biophysics and Department of Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1055 (United States); Nishiyama, Yusuke [JEOL RESONANCE Inc., Musashino, Akishima, Tokyo 196-8558 (Japan); RIKEN CLST-JEOL Collaboration Center, RIKEN, Yokohama, Kanagawa 230-0045 (Japan)

    2015-10-28

    A proton-detected 3D {sup 1}H/{sup 13}C/{sup 1}H chemical shift correlation experiment is proposed for the assignment of chemical shift resonances, identification of {sup 13}C-{sup 1}H connectivities, and proximities of {sup 13}C-{sup 1}H and {sup 1}H-{sup 1}H nuclei under ultrafast magic-angle-spinning (ultrafast-MAS) conditions. Ultrafast-MAS is used to suppress all anisotropic interactions including {sup 1}H-{sup 1}H dipolar couplings, while the finite-pulse radio frequency driven dipolar recoupling (fp-RFDR) pulse sequence is used to recouple dipolar couplings among protons and the insensitive nuclei enhanced by polarization transfer technique is used to transfer magnetization between heteronuclear spins. The 3D experiment eliminates signals from non-carbon-bonded protons and non-proton-bonded carbons to enhance spectral resolution. The 2D (F1/F3) {sup 1}H/{sup 1}H and 2D {sup 13}C/{sup 1}H (F2/F3) chemical shift correlation spectra extracted from the 3D spectrum enable the identification of {sup 1}H-{sup 1}H proximity and {sup 13}C-{sup 1}H connectivity. In addition, the 2D (F1/F2) {sup 1}H/{sup 13}C chemical shift correlation spectrum, incorporated with proton magnetization exchange via the fp-RFDR recoupling of {sup 1}H-{sup 1}H dipolar couplings, enables the measurement of proximities between {sup 13}C and even the remote non-carbon-bonded protons. The 3D experiment also gives three-spin proximities of {sup 1}H-{sup 1}H-{sup 13}C chains. Experimental results obtained from powder samples of L-alanine and L-histidine ⋅ H{sub 2}O ⋅ HCl demonstrate the efficiency of the 3D experiment.

  18. Quantification of dextrose in model solution by 1H MR spectroscopy at 1.5T

    To evaluate the feasibility of proton magnetic resonance spectroscopy (1H-MRS) using a 1.5T magnetic resonance (MR) imager for quantification of the contents of model solutions. We prepared model solutions of dextrose +water and dextrose +water + ethanol at dextrose concentrations of 0.01% to 50% and 0.01% to 20%, respectively. Using these solutions and a 1.5T MR imager together with a high-resolution nuclear magnetic resonance (NMR) spectroscope, we calculated the ratios of dextrose to water peak, (dextrose +ethanol) to water peak, and (dextrose + ethanol) to ethanol peak, as seen on MR and NMR spectra, analysing the relationships between dextrose concentration and the ratios of peaks, and between the ratios of the peaks seen on MR spectra and those seen on NMR spectra. Changes in the ratios between dextrose concentration and dextrose to water peak, (dextrose + ethanol) to water peak and (dextrose + ethanol) to ethanol peak, as seen on MR spectra, were statistically significant, and there was good linear regression. There was also close correlation between the ratios of the observed on MR and NMR spectra. The results depict the quantification of dextrose concentration according to the ratios of spectral peaks obtained by proton MRS at 1.5T. Using proton MRS at 1.5T, and on the basis of the ratios of spectcal peaks, it was possible to quantify the concentration of dextrose in model solutions of dextrose + water and dextrose + water+ ethanol. The results of this study suggest that for quantifying the contents of biofluids, the use of low-tesla 1H-MRS is feasible

  19. {sup 1}H and {sup 10}B NMR and MRI investigation of boron- and gadolinium-boron compounds in boron neutron capture therapy

    Bonora, M., E-mail: marco.bonora@unipv.it [Physics Department ' A. Volta' , University of Pavia, Via Bassi 6, 27100 Pavia (Italy)] [CNISM Unit (Italy); Corti, M.; Borsa, F. [Physics Department ' A. Volta' , University of Pavia, Via Bassi 6, 27100 Pavia (Italy)] [CNISM Unit (Italy); Bortolussi, S.; Protti, N.; Santoro, D.; Stella, S.; Altieri, S. [Nuclear and Theoretical Physics Department, University of Pavia, Via Bassi 6, 27100 Pavia (Italy)] [INFN Pavia (Italy); Zonta, C.; Clerici, A.M.; Cansolino, L.; Ferrari, C.; Dionigi, P. [Surgical Sciences Department, Experimental Surgery Laboratory, University of Pavia, Pavia (Italy); Porta, A.; Zanoni, G.; Vidari, G. [Organic Chemistry Department, University of Pavia, Via Taramelli 10, 27100 Pavia (Italy)

    2011-12-15

    {sup 10}B molecular compounds suitable for Boron Neutron Capture Therapy (BNCT) are tagged with a Gd(III) paramagnetic ion. The newly synthesized molecule, Gd-BPA, is investigated as contrast agent in Magnetic Resonance Imaging (MRI) with the final aim of mapping the boron distribution in tissues. Preliminary Nuclear Magnetic Resonance (NMR) measurements, which include {sup 1}H and {sup 10}B relaxometry in animal tissues, proton relaxivity of the paramagnetic Gd-BPA molecule in water and its absorption in tumoral living cells, are reported.

  20. Neutron Diffraction Studies of Nuclear Magnetic Ordering in Copper

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

    1989-01-01

    neutrons. By observing the (100) Bragg reflection, we have unambiguously proven antiferromagnetic ordering of the copper nuclear spins. Using a linear, position-sensitive detector, the time evolution of this peak was followed during the warm-up of the nuclear spin system. The peak intensity was found to...

  1. Nuclear magnetic resonance at 310 MHz in a superconducting solenoid

    The realisation of an NMR spectrometer with a superconducting magnet is presented in the first section. The methods to attain the best possible homogeneity of the magnetic field and to minimize the error in the spectrometer are described. The second section is devoted to the study of elastomers and nitr-oxides free radicals. A shift of the transition temperature with the magnetic field appears for the elastomers. The increasing paramagnetic shift has allowed a complete study by NMR of piperidinic and pyrrolidinic nitroxide free radicals. (author)

  2. (1)H NMR Spectroscopy of Fecal Extracts Enables Detection of Advanced Colorectal Neoplasia.

    Amiot, Aurelien; Dona, Anthony C; Wijeyesekera, Anisha; Tournigand, Christophe; Baumgaertner, Isabelle; Lebaleur, Yann; Sobhani, Iradj; Holmes, Elaine

    2015-09-01

    Colorectal cancer (CRC) is a growing cause of mortality in developing countries, warranting investigation into its etiopathogenesis and earlier diagnosis. Here, we investigated the fecal metabolic phenotype of patients with advanced colorectal neoplasia and controls using (1)H-nuclear magnetic resonance (NMR) spectroscopy and multivariate modeling. The fecal microbiota composition was assessed by quantitative real-time PCR as well as Wif-1 methylation levels in stools, serum, and urine and correlated to the metabolic profile of each patient. The predictivity of the model was 0.507 (Q(2)Y), and the explained variance was 0.755 (R(2)Y). Patients with advanced colorectal neoplasia demonstrated increased fecal concentrations of four short-chain fatty acids (valerate, acetate, propionate, and butyrate) and decreased signals relating to β-glucose, glutamine, and glutamate. The predictive accuracy of the multivariate (1)H NMR model was higher than that of the guaiac-fecal occult blood test and the Wif-1 methylation test for predicting advanced colorectal neoplasia. Correlation analysis between fecal metabolites and bacterial profiles revealed strong associations between Faecalibacterium prausnitzii and Clostridium leptum species with short-chain fatty acids concentration and inverse correlation between Faecalibacterium prausnitzii and glucose. These preliminary results suggest that fecal metabonomics may potentially have a future role in a noninvasive colorectal screening program and may contribute to our understanding of the role of these dysregulated molecules in the cross-talk between the host and its bacterial microbiota. PMID:26211820

  3. 1H NMR-based metabolite profiling of diet-induced obesity in a mouse mode

    Jee-youn Jung1,2,#, Il Yong Kim3,#, Yo Na Kim3,#, Jin-sup Kim1,5, Jae Hoon Shin3, Zi-hey Jang1,5, Ho-Sub Lee2, Geum-Sook Hwang1,5,* & Je Kyung Seong3,4,*

    2012-07-01

    Full Text Available High-fat diets (HFD and high-carbohydrate diets (HCD-induced obesity through different pathways, but the metabolicdifferences between these diets are not fully understood.Therefore, we applied proton nuclear magnetic resonance (1HNMR-based metabolomics to compare the metabolic patternsbetween C57BL/6 mice fed HCD and those fed HFD. Principalcomponent analysis derived from 1H NMR spectra of urineshowed a clear separation between the HCD and HFD groups.Based on the changes in urinary metabolites, the slow rate ofweight gain in mice fed the HCD related to activation of thetricarboxylic acid cycle (resulting in increased levels of citrateand succinate in HCD mice, while the HFD affected nicotinamidemetabolism (increased levels of 1-methylnicotineamide,nicotinamide-N-oxide in HFD mice, which leads to systemicoxidative stress. In addition, perturbation of gut microflorametabolism was also related to different metabolic patterns ofthose two diets. These findings demonstrate that 1H NMRbasedmetabolomics can identify diet-dependent perturbationsin biological pathways.

  4. Force-detected nuclear magnetic resonance: recent advances and future challenges

    We review recent efforts to detect small numbers of nuclear spins using magnetic resonance force microscopy. Magnetic resonance force microscopy (MRFM) is a scanning probe technique that relies on the mechanical measurement of the weak magnetic force between a microscopic magnet and the magnetic moments in a sample. Spurred by the recent progress in fabricating ultrasensitive force detectors, MRFM has rapidly improved its capability over the last decade. Today it boasts a spin sensitivity that surpasses conventional, inductive nuclear magnetic resonance detectors by about eight orders of magnitude. In this review we touch on the origins of this technique and focus on its recent application to nanoscale nuclear spin ensembles, in particular on the imaging of nanoscale objects with a three-dimensional (3D) spatial resolution better than 10 nm. We consider the experimental advances driving this work and highlight the underlying physical principles and limitations of the method. Finally, we discuss the challenges that must be met in order to advance the technique towards single nuclear spin sensitivity-and perhaps-to 3D microscopy of molecules with atomic resolution. (topical review)

  5. Nuclear magnetic relaxation studies of semiconductor nanocrystals and solids

    Sachleben, J. R. [Lawrence Berkeley Lab., CA (United States); California Univ., Berkeley, CA (United States). Dept. of Chemistry

    1993-09-01

    Semiconductor nanocrystals, small biomolecules, and {sup 13}C enriched solids were studied through the relaxation in NMR spectra. Surface structure of semiconductor nanocrystals (CdS) was deduced from high resolution {sup 1}H and {sup 13}C liquid state spectra of thiophenol ligands on the nanocrystal surfaces. The surface coverage by thiophenol was found to be low, being 5.6 and 26% for nanocrystal radii of 11.8 and 19.2 {angstrom}. Internal motion is estimated to be slow with a correlation time > 10{sup {minus}8} s{sup {minus}1}. The surface thiophenol ligands react to form a dithiophenol when the nanocrystals were subjected to O{sub 2} and ultraviolet. A method for measuring {sup 14}N-{sup 1}H J-couplings is demonstrated on pyridine and the peptide oxytocin; selective 2D T{sub 1} and T{sub 2} experiments are presented for measuring relaxation times in crowded spectra with overlapping peaks in 1D, but relaxation effects interfere. Possibility of carbon-carbon cross relaxation in {sup 13}C enriched solids is demonstrated by experiments on zinc acetate and L-alanine.

  6. Introduction to the controlled nuclear fusion (magnetic containment systems)

    The magnetic containment systems, their more important features, and their potentiality to became thermonuclear reactors is described. The work is based upon the first part of a set of lectures dedicated to Plasma and Fusion Physics. (author)

  7. Structural characterization of Kraft lignins from different spent cooking liquors by 1D and 2D Nuclear Magnetic Resonance spectroscopy

    Three Kraft lignins isolated from black liquors of several paper pulp mills of the North of Spain and Portugal were structurally characterized by using monodimensional (1H and 13C) and bidimensional Nuclear Magnetic Resonance (NMR) spectrometry. From the latter, 13C–1H heteronuclear single quantum correlation (HSQC) and heteronuclear multiple bond correlation (HMBC) were employed. Lignins from black liquors are usually burned for power generation. Nevertheless, they could become high value added products within a biorefinery context. In that case, a good understanding of their structure is a prior step to transform them. From all the NMR techniques studied, HSQC has risen as the most powerful tool in lignin characterization. Kraft cooking conditions and the type of wood seem to be the main factors that determine the differences observed in the lignins. All the samples have shown an important decrease in the number of β–O–4′ linkages, due to the Kraft process, and resinol has become the most resistant linkage to the process. Moreover, all samples seem to be mainly linked to a one polysaccharide: xylan. Several parameters like S/G ratio, portion of phenolic and aliphatic hydroxyls, amount of aromatic protons and other structural aspects were also estimated. - Highlights: • Lignins from three Kraft spent liquors were obtained by acid precipitation. • Structural characterization of the dissolved lignins was performed by NMR. • Wood source and pulping conditions determine the lignin characteristics. • Kraft process implies cleavage of β–O–4 linkages and survival of resinol linkages. • Comparison of the samples would aid decisions on its future revalorization

  8. Development of magnetic dynamic damper for nuclear power plant

    This paper describes a magnetic dynamic damper (MDD), which is a passive vibration absorber employing a permanent magnet and a conductor for both the restoring and damping force. The basic characteristics of this magnetic spring and damper system are examined through static loading tests and vibration tests using a pair of double cylindrical magnets. It is confirmed that the magnetic force analysis accurately simulates these test results. Application of this system to a rotating machinery model shows that the MDD can effectively reduce two-dimensional vibration. Moreover, through the forced vibration test in which MDD is attached to the bottom of vertical pump, it is examined that the proposed MDD can be applicable for seismic response reduction over the wide region of pump casing displacement. The top heavy valve equipped on piping vibrates biaxially at different frequencies. In this case, it is confirmed from the vibration tests using a valve-piping model that the MDD with multiple rectangular magnets is effective in reducing two-dimensional vibration with different frequencies. (author)

  9. Identification of fucans from four species of sea cucumber by high temperature 1H NMR

    Wu, Nian; Chen, Shiguo; Ye, Xingqian; Li, Guoyun; Yin, Li'ang; Xue, Changhu

    2014-10-01

    Acidic polysaccharide, which has various biological activities, is one of the most important components of sea cucumber. In the present study, crude polysaccharide was extracted from four species of sea cucumber from three different geographical zones, Pearsonothuria graeffei ( Pg) from Indo-Pacific, Holothuria vagabunda ( Hv) from Norwegian Coast, Stichopus tremulu ( St) from Western Indian Ocean, and Isostichopus badionotu ( Ib) from Western Atlantic. The polysaccharide extract was separated and purified with a cellulose DEAE anion-exchange column to obtain corresponding sea cucumber fucans (SC-Fucs). The chemical property of these SC-Fucs, including molecular weight, monosaccharide composition and sulfate content, was determined. Their structure was compared simply with fourier infrared spectrum analyzer and identified with high temperature 1H nuclear magnetic resonance spectrum analyzer (NMR) and room temperature 13C NMR. The results indicated that Fuc- Pg obtained from the torrid zone mainly contained 2,4-O-disulfated and non-sulfated fucose residue, whereas Fuc- Ib from the temperate zone contained non-, 2-O- and 2,4-O-disulfated fucose residue; Fuc- St from the frigid zone and Fuc- Hv from the torrid zone contained mainly non-sulfated fucose residue. The proton of SC-Fucs was better resolved via high temperature 1H NMR than via room temperature 1H NMR. The fingerprint of sea cucumber in different sea regions was established based on the index of anomer hydrogen signal in SC-Fucs. Further work will help to understand whether there exists a close relationship between the geographical area of sea cucumber and the sulfation pattern of SC-Fucs.

  10. Nuclear magnetic resonance detection and spectroscopy of single proteins using quantum logic

    Lovchinsky, I.; Sushkov, A. O.; Urbach, E.; de Leon, N. P.; Choi, S.; De Greve, K.; Evans, R.; Gertner, R.; Bersin, E.; Müller, C.; McGuinness, L.; Jelezko, F.; Walsworth, R. L.; Park, H.; Lukin, M. D.

    2016-02-01

    Nuclear magnetic resonance spectroscopy is a powerful tool for the structural analysis of organic compounds and biomolecules but typically requires macroscopic sample quantities. We use a sensor, which consists of two quantum bits corresponding to an electronic spin and an ancillary nuclear spin, to demonstrate room temperature magnetic resonance detection and spectroscopy of multiple nuclear species within individual ubiquitin proteins attached to the diamond surface. Using quantum logic to improve readout fidelity and a surface-treatment technique to extend the spin coherence time of shallow nitrogen-vacancy centers, we demonstrate magnetic field sensitivity sufficient to detect individual proton spins within 1 second of integration. This gain in sensitivity enables high-confidence detection of individual proteins and allows us to observe spectral features that reveal information about their chemical composition.

  11. Structural characterization by Nuclear Magnetic Resonance of ozonized triolein

    F. Díaz, Maritza

    2008-09-01

    Full Text Available In the present study ozonized triolein with 739 mmolequiv/ kg peroxide index is characterized by NMR.The triolein and ozonized triolein show very similar 1H NMR spectra except for the resonances at δ 9.74 ppm, which correspond to aldehydic protons and δ 5.14 ppm (ozonides methylic protons. Other new signal assignments are based on the connectivities provided by the proton scalar coupling constants δ 2.41 ppm (methylenic group allylic to aldehydic protons and ozonides methynic protons and δ 1.67 ppm (methylenic protons in position with respect to ozonides methylic protons. From the 13C and 1H-13C spectrum of the ozonized triolein, the presence of ozonides was confirmed by the signals δ 104.2 and 104.3 ppm, respectively. Other new signals in δ 43.9 ppm confirm the presence of methylenic carbon ozonides. From the structural elucidation of ozonated triglycerides, relevant chemical information about ozonated vegetable oil can be found .En el presente estudio ha sido caracterizada por RMN la trioleina ozonizada con índice de peróxidos de 739 mmolequiv/ kg. La trioleina y la trioleina ozonizada muestran espectros muy similares exceptuando los valores de las resonancias δ 9,74 ppm de los protones aldehídicos, y δ 5,14 ppm (protones metínicos de los ozónidos. Otras nuevas asignaciones fueron basadas en las conectividades obtenidas por las constantes de acoplamiento escalar como δ 2,41 ppm (grupo metilénico alilico a los protones aldehídicos y protones metínicos de los ozónidos y δ 1,67 ppm (protones metilénicos en posición βcon respecto a los protones metínicos de los ozónidos. En los espectros 13C y 1H-13C de la trioleina ozonizada la presencia de ozónidos fue atribuida, respectivamente, por las señales δ 104,2 y δ 104,3 ppm. Una nueva señal en δ 43,9 ppm confirma la presencia de carbono metilénico de ozónidos. Estos resultados indican que la elucidación estructural de triglicéridos ozonizados, ofrece información qu

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

    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.

  13. Nuclear magnetic resonance imaging in patients with hypertrophic and dilated cardiomyopathy

    Patients with hypertrophic and dilated cardiomyopathy and normal subjects were investigated with nuclear magnetic resonance imaging. To evaluate the NMR scanner possibilities, the results were compared with the echocardiographic investigation of the same patients. The capabilities of NMR imaging to provide information about intracardiac anatomy are emphasized. This study is preceded by a description of the physical principles underlying the phenomenon of nuclear magnetic resonance and of the techniques used to obtain NMR images and a review of the clinical use of NMR imaging for cardiac diagnosis

  14. Diamond-nitrogen-vacancy electronic and nuclear spin-state anticrossings under weak transverse magnetic fields

    Clevenson, Hannah; Chen, Edward H.; Dolde, Florian; Teale, Carson; Englund, Dirk; Braje, Danielle

    2016-08-01

    We report on detailed studies of electronic and nuclear spin states in the diamond-nitrogen-vacancy (NV) center under weak transverse magnetic fields. We numerically predict and experimentally verify a previously unobserved NV hyperfine level anticrossing (LAC) occurring at bias fields of tens of gauss—two orders of magnitude lower than previously reported LACs at ˜500 and ˜1000 G axial magnetic fields. We then discuss how the NV ground-state Hamiltonian can be manipulated in this regime to tailor the NV's sensitivity to environmental factors and to map into the nuclear spin state.

  15. Nuclear magnetic resonance analysis of freeze-thaw damage in natural pumice concrete

    Wang, Xiaoxiao; Shen, Xiangdong; Wang, Hailong; Gao, Chu; Zhang, Tong

    2016-01-01

    This paper presents an analysis of the damage propagation features of the pore structure of natural pumice lightweight aggregate concrete (LWC) under freeze-thaw cyclic action. After freeze-thaw cycling, we conducted nuclear magnetic resonance (NMR) tests on the concrete and acquired the porosity, distribution of transverse relaxation time T2, and magnetic resonance imaging (MRI) results. The results showed the following. The T2 distribution of the LWC prior to freeze-thaw cycling presented f...

  16. SQUIDs vs. Induction Coils for Ultra-Low Field Nuclear Magnetic Resonance: Experimental and Simulation Comparison

    Matlashov, Andrei N.; Schultz, Larry J.; Espy, Michelle A.; Kraus, Robert H.; Savukov, Igor M.; Volegov, Petr L.; Wurden, Caroline J.

    2011-01-01

    Nuclear magnetic resonance (NMR) is widely used in medicine, chemistry and industry. One application area is magnetic resonance imaging (MRI). Recently it has become possible to perform NMR and MRI in the ultra-low field (ULF) regime requiring measurement field strengths of the order of only 1 Gauss. This technique exploits the advantages offered by superconducting quantum interference devices or SQUIDs. Our group has built SQUID based MRI systems for brain imaging and for liquid explosives d...

  17. Materials of the 39 Polish Seminar on Nuclear Magnetic Resonance and Its Applications - Abstracts

    The Report comprises abstracts of 78 communications presented during the 39 Polish Seminar on Nuclear Magnetic Resonance and Its Applications, held on November, 30 - December, 2006 in Cracow (PL). They cover a variety of research fields, including magnetic resonance imaging in vivo, applications of NMR spectroscopy to medical diagnosis, studies on molecular properties of different materials as well as quantum chemical calculations of NMR parameters

  18. Determination of the Defining Boundary in Nuclear Magnetic Resonance Diffusion Experiments

    Laun, Frederik Bernd; Kuder, Tristan Anselm; Semmler, Wolfhard; Stieltjes, Bram

    2010-01-01

    While nuclear magnetic resonance diffusion experiments are widely used to resolve structures confining the diffusion process, it has been elusive whether they can exactly reveal these structures. This question is closely related to X-ray scattering and to Kac's "hear the drum" problem. Although the shape of the drum is not "hearable", we show that the confining boundary of closed pores can indeed be detected using modified Stejskal-Tanner magnetic field gradients that preserve the phase infor...

  19. 41 Polish Seminar on Nuclear Magnetic Resonance and Its Applications - Abstracts

    The Report consist of abstracts of 63 communications presented during the 41 Polish Seminar on Nuclear Magnetic Resonance and Its Applications, held on December 1-2, 2008 in Cracow. Presentations cover a variety of research fields, including magnetic resonance imaging in vivo, applications of NMR spectroscopy to medical diagnosis, studies on molecular properties of different materials as well as quantum chemical calculations of NMR parameters

  20. 1H MR spectroscopy characteristics of cerebral alveolar echinococcosis

    Objective: To investigate the characteristics of proton magnetic resonance spectroscopy (1H MRS) in patients with cerebral alveolar echinococcosis (CAE). Methods: Thirteen patients with 33 lesions proven to be CAE histologically and clinically were examined by conventional MRI and 2D multi-voxel spectroscopy with a 3.0 T double gradient superconductivity magnetic resonance scanner. Concentrations of the metabolites containing N-acetyl-aspartic-acid (NAA), Choline (Cho), Creatine (Cr), lipids and lactic acid (Lip + Lac), myo-Inositol (mI) were detected and the value of Cho/Cr, NAA/Cr, (Lip + Lac)/Cr, mI/Cr were calculated. The values of Cho/Cr, NAA/Cr, (Lip + Lac)/Cr, mI/Cr were compared between the lesions and the contralateral normal brain parenchyma. Statistical analysis was performed using the Wilcoxon signed-rank test. Results: CAE 1H MRS in the lesions was characterized by the decrease of Cho, NAA to varying degrees, and a visible lipid with or without lactate peak. Compared with the control group, the ratio of NAA/Cr was decreased markedly, whereas Cho/Cr, mI/Cr increased mildly and (Lip + Lac)/Cr increased markedly in the lesions. The medians and interquartile ranges of Cho/Cr, NAA/Cr, (Lip + Lac)/Cr and mI/Cr in the lesions were: 1.88 (1.24-2.23), 1.32 (1.07-1.58), 32.96 (24.59-47.30) and 0.91 (0.67-1.08), respectively. The medians and interquartile ranges of Cho/Cr, NAA/Cr, (Lip + Lac)/Cr and mI/Cr of control group were 0.84 (0.704-0.98), 2.00 (1.80-2.18), 0.90 (0.74-0.99) and 0.26 (0.18-0.31), respectively. There were statistically significant differences of the measures between the lesions and the control regions (Z=-5.932, -6.086, -6.946, -6.984, P<0.01). Conclusions: Multi-voxel 1H MRS can reflect pathological characteristics of CAE. 1H MRS provides metabolic information for diagnosis of CAE and may be a supplement to conventional magnetic resonance examination. (authors)

  1. Quantum Computation Based on Magic-Angle-Spinning Solid State Nuclear Magnetic Resonance Spectroscopy

    Ding, Shangwu; McDowell, Charles A.; Ye, Chaohui; Zhan, Mingsheng; Zhu, Xiwen; Gao, Kelin; Sun, Xianping; Mao, Xi-An; Liu, Maili

    2001-01-01

    Magic-angle spinning (MAS) solid state nuclear magnetic resonance (NMR) spectroscopy is shown to be a promising technique for implementing quantum computing. The theory underlying the principles of quantum computing with nuclear spin systems undergoing MAS is formulated in the framework of formalized quantum Floquet theory. The procedures for realizing state labeling, state transformation and coherence selection in Floquet space are given. It suggests that by this method, the largest number o...

  2. Nuclear magnetic resonance relaxation and diffusion in the presence of internal gradients: the effect of magnetic field strength.

    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. PMID:20365625

  3. 59Co NMR and nuclear magnetic relaxation study of the magnetic superconductor Y9Co7

    The magnetic superconductor Y9Co7 presented in its structure magnetic and non-magnetic Co atoms. A search was made of the 59Co NMR lines attributed in the literature to magnetic Co atoms, With negative results. For the strong 59Co NMR line arising from nuclei of non-magnetic Co atoms the relaxation times T1 and T2 versus temperature were measured directly at 6.5 MHz and 9.0 MHz. A linear dependence on temperature was observed for 1/T1 which can be attributed to interactions with conduction electrons. 1/T2 is not linear with temperature, an effect that is related to the temperature dependence of the magnetization. (Authors)

  4. Nuclear magnetic resonance imaging of the central nervous system

    In this article a review is given of the use of magnetic resonance imaging for the central nervous system. An example of the screening of the population for multiple scelerosis is given. A good preliminary examination and the supply of relevant information to the person which performs the imaging is necessary. (R.B.). 9 figs.; 4 tabs

  5. Design of Matrix Shim Coils System for Nuclear magnetic resonance

    Konzbul, Pavel; Švéda, Karel; Srnka, Aleš

    2000-01-01

    Roč. 36, č. 4 (2000), s. 1732-1735. ISSN 0018-9464. [COMPUMAG /12./. Sapporo, 25.10.1999-28.10.1999] R&D Projects: GA MŠk ME 181 Institutional research plan: CEZ:AV0Z2065902 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.720, year: 2000

  6. Preparation, GIAO NMR Calculations and Acidic Properties of Some Novel 4,5-dihydro-1H-1,2,4-triazol-5-one Derivatives with Their Antioxidant Activities

    Havva Aksu

    2008-01-01

    Full Text Available Six novel 3-alkyl(aryl-4-(p-nitrobenzoylamino-4,5-dihydro-1H-1,2,4-triazol-5- ones (2a-f were synthesized by the reactions of 3-alkyl(aryl-4-amino-4,5-dihydro-1H- 1,2,4-triazol-5-ones (1a-f with p-nitrobenzoyl chloride and characterized by elemental analyses and IR, 1H-NMR, 13C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as acetone, isopropyl alcohol, tert-butyl alcohol and N,Ndimethylformamide, and the half-neutralization potential values and the corresponding pKa values were determined for all cases. Thus, the effects of solvents and molecular structure upon acidity were investigated. In addition, isotropic 1H and 13C nuclear magnetic shielding constants of compounds 2 were obtained by the gauge-including-atomic-orbital (GIAO method at the B3LYP density functional level. The geometry of each compound has been optimized using the 6-311G basis set. Theoretical values were compared to the experimental data. Furthermore, these new compounds and five recently reported 3-alkyl-4-(2- furoylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones (3a-c,e,f were screened for their antioxidant activities.

  7. Nuclear magnetic resonance investigation of dynamics in poly(ethylene oxide)-based lithium polyether-ester-sulfonate ionomers

    Nuclear magnetic resonance (NMR) spectroscopy has been utilized to investigate the dynamics of poly(ethylene oxide)-based lithium sulfonate ionomer samples that have low glass transition temperatures. 1H and 7Li spin-lattice relaxation times (T1) of the bulk polymer and lithium ions, respectively, were measured and analyzed in samples with a range of ion contents. The temperature dependence of T1 values along with the presence of minima in T1 as a function of temperature enabled correlation times and activation energies to be obtained for both the segmental motion of the polymer backbone and the hopping motion of lithium cations. Similar activation energies for motion of both the polymer and lithium ions in the samples with lower ion content indicate that the polymer segmental motion and lithium ion hopping motion are correlated in these samples, even though their respective correlation times differ significantly. A divergent trend is observed for correlation times and activation energies of the highest ion content sample with 100% lithium sulfonation due to the presence of ionic aggregation. Details of the polymer and cation dynamics on the nanosecond timescale are discussed and complement the findings of X-ray scattering and Quasi Elastic Neutron Scattering experiments

  8. Comparison of electrochemical- and nuclear magnetic resonance spectroscopy methods for determination of diffusion coefficients in gel environment

    Two advanced methods: one based on chronoamperometry in solution of any ionic strength and the second one related to nuclear magnetic resonance spectroscopy (NMR) were used to determine the difusion coefficients of the selected species in complex polymeric gels. For this purpose a series of polyacrylamide gels with different content of monomer and crosslinker were synthesized. Rod shaped samples of polymers were swelled with solutions of either 1,1'-ferrocenedimethanol, or 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt or cis-dichlorobis(2,2′-bipyridine) ruthenium(II) in D2O. These compounds were good probes for examining the transport in the gel medium due to electrochemical reaction and well-defined signals in 1H NMR spectroscopy. The values of diffusion coefficients obtained by both methods were compared and the limitations of the methods were discussed. The measurements were done at three temperatures: 25, 35 and 45 °C

  9. Development of new methods for assessing solidification/stabilization of hazardous waste using solid-state nuclear magnetic resonance techniques

    New methods for assessing solidification/stabilization (S/S) of hazardous waste using solid-state nuclear magnetic resonance are developed for the purpose of diagnosing on a microscopic level the performance of S/S as a hazardous waste disposal technique. There are four techniques developed and described in this dissertation: (1) Solid-state deuterium NMR spectroscopy is used to determine if a particular deuterated organic waste is effectively solidified/stabilized and to determine the lower limit of the bond strength between the waste and the cement matrix; (2) Constant time pulsed field gradient 1H NMR spectroscopy is tested on a liquid waste encapsulated within a solidified matrix to determine if droplets of liquid waste are entrapped within a solidified matrix. It yields a size distribution image of vesicles containing fluids, and measures the diffusion rate of organic materials in solid matrices; (3) Three-dimensional NMR imaging of a hazardous waste/cement sample is tested for the determination of the pore structure connectivity pattern and the observation of waste leaching; (4) NMR hole-burning spectroscopy is attempted for the study of the microscopic motions of waste in the cement matrix. These NMR techniques give information on the microscopic waste/cement interactions while providing a nondestructive evaluation of the quality of S/S process much superior to the destructive techniques such as leaching

  10. Serum nuclear magnetic resonance-based metabolomics and outcome in diffuse large B-cell lymphoma patients - a pilot study.

    Stenson, Martin; Pedersen, Anders; Hasselblom, Sverker; Nilsson-Ehle, Herman; Karlsson, Bengt Göran; Pinto, Rui; Andersson, Per-Ola

    2016-08-01

    The prognosis for diffuse large B-cell lymphoma (DLBCL) patients with early relapse or refractory disease is dismal. To determine if clinical outcome correlated to diverse serum metabolomic profiles, we used (1)H nuclear magnetic resonance (NMR) spectroscopy and compared two groups of DLBCL patients treated with immunochemotherapy: i) refractory/early relapse (REF/REL; n=27) and ii) long-term progression-free (CURED; n = 60). A supervised multivariate analysis showed a separation between the groups. Among discriminating metabolites higher in the REF/REL group were the amino acids lysine and arginine, the degradation product cadaverine and a compound in oxidative stress (2-hydroxybutyrate). In contrast, the amino acids aspartate, valine and ornithine, and a metabolite in the glutathione cycle, pyroglutamate, were higher in CURED patients. Together, our data indicate that NMR-based serum metabolomics can identify a signature for DLBCL patients with high-risk of failing immunochemotherapy, prompting for larger validating studies which could lead to more individualized treatment of this disease. PMID:26887805

  11. Nuclear magnetic resonance J coupling constant polarizabilities of hydrogen peroxide

    Kjær, Hanna; Nielsen, Monia R.; Pagola, Gabriel I.;

    2012-01-01

    In this paper we present the so far most extended investigation of the calculation of the coupling constant polarizability of a molecule. The components of the coupling constant polarizability are derivatives of the NMR indirect nuclear spin-spin coupling constant with respect to an external elec...

  12. One-pion exchange current corrections for nuclear magnetic moments in relativistic mean field theory

    Li, Jian; Meng, J; Arima, A

    2010-01-01

    The one-pion exchange current corrections to isoscalar and isovector magnetic moments of double-closed shell nuclei plus and minus one nucleon with $A=15,17,39$ and 41 have been studied in the relativistic mean field (RMF) theory and compared with previous relativistic and non-relativistic results. It has been found that the one-pion exchange current gives a negligible contribution to the isoscalar magnetic moments but a significant correction to the isovector ones. However, the one-pion exchange current doesn't improve the description of nuclear isovector magnetic moments for the concerned nuclei.

  13. 3T磁共振氢质子波谱在骨与软组织肿瘤诊断中的应用价值%Application Value of 3T 1H-Magnetic Resonance Spectroscopy in Diagnosing Tumors of Bone and Soft Tissue

    齐滋华; 李传福; 马祥兴; 李振峰; 张凯; 于德新

    2011-01-01

    Objective To study benign and malignant bone and soft tissue tumors with H-magnetic resonance spectroscopy ( H-MRS) at 3 Tesla MR scanner and assess the value of H-MRS in diagnosing bone and soft tissue tumors and distinguishing benign from malignant tumors. Methods Totally 49 patients with clinically and pathologically confirmed bone and soft tissue tumors were enrolled in this study. H-MRS was performed before treatment with point-resolved spectroscopy sequence. The imaging characteristics of 'H-MRS for bone and soft tissue tumors were observed and the possible differences between benign and malignant tumors was compared. Since spectra were directly found under single-voxel proton MRS brain examination, the peak height of choline containing compounds ( Cho) opposite to the creatine ( Cr) and the Cho peak were observed, and then the malignancies of the tumors were judged. Cho/Cr value was calculated and used to distinguishing benign tumors from malignancies. Results 'H-MRS spectra of bone and soft tissue tumors were different from those of the normal muscles, and such difference also existed between benign and malignant tumors. The Cho\\peak disappeared or was extremely low among benign tumors. The Cho/Cr values of malignant tumors and benign tumors were 3. 13 ±0. 9 and 1. 34 ± 1. 02 , respectively ( P = 0. 02). Using 1.79 as the threshold value, the Cho/Cr value had sensitivity, specificity, and accuracy of 94% , 80% , and 90% , respectively, in diagnosing malignancies. Conclusions The increased Cho level, as measured by ' H-MRS, is related with the bone and soft tissue malignant tumor. Cho/Cr value is useful in distinguishing benign tumors from malignancies. H-MRS can be an important supplement to the conventional magnetic resonance imaging.%目的 应用超高场3T磁共振机对良、恶性骨与软组织肿瘤进行磁共振氢质子波谱(1 H-MRS)研究,探讨1 H-MRS对骨与软组织肿瘤的成像特点,及对良、恶性骨与软组织肿瘤鉴

  14. Bohr-Weisskopf effect: influence of the distributed nuclear magnetization on hfs

    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 (B-W) 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 nuclear magnetic moments. A novel atomic beam magnetic resonance (ABMR) method, combining rf and laser excitation, has been developed for a systematic study and initially applied to stable isotopes. Difficulties in adapting the experiment to the ISOLDE radioactive ion beam, which have now been surmounted, are discussed. A first radioactive beam measurement for this study, the precision hfs of 126Cs, has been obtained recently. The result is 3629.515( 0.001) MHz. The ability of ABMR to determine with high precision nuclear magnetic moments in free atoms is a desideratum for the extraction of QED effects from the hfs of the hydrogen-like ions. We also point out manifestations of B-W in condensed matter and atomic physics

  15. Progress on tilted axis cranking covariant density functional theory for nuclear magnetic and antimagnetic rotation

    孟杰; 彭婧; 张双全; 赵鹏巍

    2013-01-01

    Magnetic rotation and antimagnetic rotation are exotic rotational phenomena observed in weakly deformed or near-spherical nuclei, which are respectively interpreted in terms of the shears mechanism and two shearslike mechanism. Since their observations, magnetic rotation and antimagnetic rotation phenomena have been mainly investigated in the framework of tilted axis cranking based on the pairing plus quadrupole model. For the last decades, the covariant density functional theory and its extension have been proved to be successful in describing series of nuclear ground-states and excited states properties, including the binding energies, radii, single-particle spectra, reso- nance states, halo phenomena, magnetic moments, magnetic rotation, low-lying excitations, shape phase transitions, collective rotation and vibrations, etc. This review will mainly focus on the tilted axis cranking covariant density functional theory and its application for the magnetic rotation and antimagnetic rotation phenomena.

  16. Synthesis of fatty trichloromethyl-{beta}-diketones and new 1H-Pyrazoles as unusual FAMEs and FAEEs

    Flores, Alex F.C.; Souto, Alynne A.; Malavolta, Juliana L.; Flores, Darlene C., E-mail: alex.fcf@ufsm.br [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Departamento de Quimica; Blanco, Rogerio F. [Uniao de Ensino do Sudoeste do Parana (UNISEP), Dois Vizinhos, PR (Brazil). Faculdade de Farmacia

    2013-12-01

    The efficient synthesis of new fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones [Cl{sub 3}CC(O)C(R{sup 2})=C(R{sup 1})OMe, where R{sup 1} = n-hexyl, heptyl, nonyl, undecyl, tridecyl and R{sup 2} = H] and 1,1,1-trichloro-2,4-alkanediones [Cl{sub 3}CC(O)CHR{sup 2}C(O)R{sup 1}, where R{sup 1} = n-pentyl and R{sup 2} = Me, R{sup 1} = Et and R{sup 2} = n-butyl, R{sup 1} = n-butyl and R{sup 2} = n-propyl] in good yields (85-95%) from acetal acylation with trichloroacetyl chloride is reported. The fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones and 1,1,1-trichloro-2,4-alkanediones were reacted with hydrazine hydrochloride, leading to respective {sup 1}H-pyrazole-5-carboxylates, unusual class of fatty acid methyl (FAMEs) and ethyl (FAEEs) esters. Their structures were confirmed by elemental analysis and {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR). The fatty 1,1,1-trichloro-4-methoxy-3-alken-2-ones and {sup 1}H-pyrazole derivatives are new oleochemicals with potentially interesting and differential properties. (author)

  17. Nuclear magnetic relaxation studies on polyelectrolytes with water

    Studies on the longitudinal and transverse relaxation times (T1 and T2) of 1H and 23Na in water-polyelectrolytes systems were carried out. The polyelectrolyte samples used were sodium polystyrene sulfonate, sodium lignosulfonate and sodium cellulose sulfate. The water content (Wc's) of the samples was varied from 0 to 2.0 (grams of water per gram of polyelectrolyte). A minimum value for 1HT1 values of water in the system was observed at a temperature ranging from -25 to -40 degree C. The temperature where the 1HT1 minimum value was observed depended on Wc, corresponding to the crystallization of water in each system. From 1HT1 two groups of water molecules (bound and free water) are considered to exist in water-polyelectrolyte systems. The calculated τc values of bound water increased with decreasing temperature from the order of 10-7 sec to 10-6 sec. The observed 23Na in the water-polyelectrolyte systems relaxed with a single T1. 23NaT2 values showed that the relaxation process was separated into two fractions

  18. Nuclear magnetic resonance spectroscopy, analytical chemistry by open learning

    This elementary text on NMR spectroscopy is designed for self-study, primarily by those studying to be chemical technicians. The style is informal and direct. The basic elements of chemical shifts, spin-spin coupling, integrated intensities, and relaxation times are discussed briefly, with examples, but the emphasis is much more on this is the way it is than on providing a satisfying rationale. Quick introduction to sample preparation, NMR instrumentation, and signal enhancement techniques are included, but these are very sketchy. Only four pages are devoted to the Fourier Transform technique, hardly enough to give anyone a reasonable basis for understanding the technique and its power. About a third of the main part of the text is devoted to practical applications of 1H and 13C NMR spectroscopy, including structural assignments of peaks in the spectra of simple molecules and quantitative measurements of simple mixtures. The author provides a variety of questions and problems throughout the book, some of the simple memory-retention type but some more thought-provoking. The last 90 pages of the book are devoted to answering the questions and problems posed in the five chapters

  19. Applications of multi-nuclear magnetic resonance spectroscopy at 7T

    Mary C Stephenson

    2011-04-01

    Full Text Available AIM: To discuss the advantages of ultra-high field (7T for 1H and 13C magnetic resonance spectroscopy (MRS studies of metabolism.METHODS: Measurements of brain metabolites were made at both 3 and 7T using 1H MRS. Measurements of glycogen and lipids in muscle were measured using 13C and 1H MRS respectively.RESULTS: In the brain, increased signal-to-noise ratio (SNR and dispersion allows spectral separation of the amino-acids glutamate, glutamine and γ-aminobutyric acid (GABA, without the need for sophisticated editing sequences. Improved quantification of these metabolites is demonstrated at 7T relative to 3T. SNR was 36% higher, and measurement repeatability (% coefficients of variation was 4%, 10% and 10% at 7T, vs 8%, 29% and 21% at 3T for glutamate, glutamine and GABA respectively. Measurements at 7T were used to compare metabolite levels in the anterior cingulate cortex (ACC and insula. Creatine and glutamate levels were found to be significantly higher in the insula compared to the ACC (P < 0.05. In muscle, the increased SNR and spectral resolution at 7T enables interleaved studies of glycogen (13C and intra-myocellular lipid (IMCL and extra-myocellular lipid (EMCL (1H following exercise and re-feeding. Glycogen levels were significantly decreased following exercise (-28% at 50% VO2 max; -58% at 75% VO2 max. Interestingly, levels of glycogen in the hamstrings followed those in the quadriceps, despite reduce exercise loading. No changes in IMCL and EMCL were found in the study.CONCLUSION: The demonstrated improvements in brain and muscle MRS measurements at 7T will increase the potential for use in investigating human metabolism and changes due to pathologies.

  20. Nuclear magnetic resonance imaging in diseases of the white matter

    The progress made in the field of medical imaging since the advent of magnetic resonance tomography is particularly evident in many disorders that are a domain of neuroradiology. The diagnosis and differential diagnosis of diseases of the white matter not only require accurate examination techniques but must just as well be based on the clinical symptoms observed. In the detection of diseases of the white matter magnetic resonance tomography is much more sensitive a tool than computed tomography. As it is normal for the images of any lesions to be isointense or hypointense as a result of T1 weighting and hyperintense in connection with T2 weighting, they may lead to a doubtful diagnosis, unless the interpretation is made by an experienced investigator taking account also of the pattern of structural changes and the neurologic-psychiatric manifestations of the disease. (orig.)