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Sample records for 1h nuclear magnetic

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

    CERN Document Server

    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...

  2. Characterisation of human embryonic stem cells conditioning media by 1H-nuclear magnetic resonance spectroscopy.

    Directory of Open Access Journals (Sweden)

    David A MacIntyre

    Full Text Available BACKGROUND: Cell culture media conditioned by human foreskin fibroblasts (HFFs provide a complex supplement of protein and metabolic factors that support in vitro proliferation of human embryonic stem cells (hESCs. However, the conditioning process is variable with different media batches often exhibiting differing capacities to maintain hESCs in culture. While recent studies have examined the protein complement of conditioned culture media, detailed information regarding the metabolic component of this media is lacking. METHODOLOGY/PRINCIPAL FINDINGS: Using a (1H-Nuclear Magnetic Resonance ((1H-NMR metabonomics approach, 32 metabolites and small compounds were identified and quantified in media conditioned by passage 11 HFFs (CMp11. A number of metabolites were secreted by HFFs with significantly higher concentration of lactate, alanine, and formate detected in CMp11 compared to non-conditioned media. In contrast, levels of tryptophan, folate and niacinamide were depleted in CMp11 indicating the utilisation of these metabolites by HFFs. Multivariate statistical analysis of the (1H-NMR data revealed marked age-related differences in the metabolic profile of CMp11 collected from HFFs every 24 h over 72 h. Additionally, the metabolic profile of CMp11 was altered following freezing at -20°C for 2 weeks. CM derived from passage 18 HFFs (CMp18 was found to be ineffective at supporting hESCs in an undifferentiated state beyond 5 days culture. Multivariate statistical comparison of CMp11 and CMp18 metabolic profiles enabled rapid and clear discrimination between the two media with CMp18 containing lower concentrations of lactate and alanine as well as higher concentrations of glucose and glutamine. CONCLUSIONS/SIGNIFICANCE: (1H-NMR-based metabonomics offers a rapid and accurate method of characterising hESC conditioning media and is a valuable tool for monitoring, controlling and optimising hESC culture media preparation.

  3. Serum Metabolomic Profiling of Sulphur Mustard-Exposed Individuals Using (1)H Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Zamani, Zahra; Ghanei, Mostafa; Panahi, Yunus; Arjmand, Mohammad; Sadeghi, Sedigheh; Mirkhani, Fatemeh; Parvin, Shahram; Salehi, Maryam; Sahebkar, Amirhossein; Vahabi, Farideh

    2016-01-01

    Sulphur mustard is an alkylating agent that reacts with different cellular components, causing acute and delayed complications that may remain for decades after exposure. This study aimed to identify differentially expressed metabolites between mustard-exposed individuals suffering from chronic complications compared with unexposed individuals as the control group. Serum samples were obtained from 15 mustard-exposed individuals and 15 apparently healthy unexposed individuals. Metabolomic profiling was performed using (1)H nuclear magnetic resonance spectroscopy, and analyses were carried out using Chenomex and MATLAB softwares. Metabolites were identified using Human Metabolome Database, and the main metabolic pathways were identified using MetaboAnalyst software. Chemometric analysis of serum samples identified 11 differentially expressed metabolites between mustard-exposed and unexposed groups. The main pathways that were influenced by sulphur mustard exposure were related to vitamin B6 (down-regulation), bile acid (up-regulation) and tryptophan (down-regulation) metabolism. Metabolism of vitamin B6, bile acids and tryptophan are the most severely impaired pathways in individuals suffering from chronic mustard-induced complications. These findings may find implications in the monitoring of exposed patients and identification of new therapeutic approaches.

  4. (1)H nuclear magnetic resonance-based metabolomics study of earthworm Perionyx excavatus in vermifiltration process.

    Science.gov (United States)

    Wang, Lei; Huang, Xulei; Laserna, Anna Karen Carrasco; Li, Sam Fong Yau

    2016-10-01

    In this study, (1)H nuclear magnetic resonance (NMR)-based metabolomics approach was used to characterize the metabolic response of the earthworm Perionyx excavatus in continuous vermifiltration for two months under hydraulic loading rates of 1m(3)m(-2)d(-1) (VF1) and 1.5m(3)m(-2)d(-1) (VF1.5). Both VF1 and VF1.5 showed higher removal of chemical oxygen demand and total nitrogen than the biofilter without earthworms. Principal component analysis of the NMR spectra of earthworm metabolites showed significant separations between those not subjected to wastewater filtration (control) and VF1 or VF1.5. Temporal variations of earthworm biomass, and the identified metabolites that are significantly different between control, VF1 and VF1.5 revealed that worms underwent increasing metabolic activity within 20days in VF1 and 14days in VF1.5, then decreasing metabolic activity. The use of NMR-based metabolomics in monitoring earthworm metabolism was demonstrated to be a novel approach in studying engineered vermifiltration systems.

  5. 1H nuclear magnetic resonance spectroscopy-basedmetabonomic study in patients with cirrhosis and hepaticencephalopathy

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    AIM To identify plasma metabolites used as biomarkersin order to distinguish cirrhotics from controls and encephalopathics.METHODS: A clinical study involving stable cirrhoticpatients with and without overt hepatic encephalopathywas designed. A control group of healthy volunteers wasused. Plasma from those patients was analysed using1H - nuclear magnetic resonance spectroscopy. Weused the Carr Purcell Meiboom Gill sequence to processthe sample spectra at ambient probe temperature. Weused a gated secondary irradiation field for water signalsuppression. Samples were calibrated and referencedusing the sodium trimethyl silyl propionate peak at0.00 ppm. For each sample 128 transients (FID's)were acquired into 32 K complex data points over aspectral width of 6 KHz. 30 degree pulses were appliedwith an acquisition time of 4.0 s in order to achievebetter resolution, followed by a recovery delay of 12s, to allow for complete relaxation and recovery ofthe magnetisation. A metabolic profile was created forstable cirrhotic patients without signs of overt hepaticencephalopathy and encephalopathic patients as wellas healthy controls. Stepwise discriminant analysis wasthen used and discriminant factors were created todifferentiate between the three groups.RESULTS: Eighteen stabled cirrhotic patients, eighteenpatients with overt hepatic encephalopathy and seventeenhealthy volunteers were recruited. Patients with cirrhosishad significantly impaired ketone body metabolism, ureasynthesis and gluconeogenesis. This was demonstratedby higher concentrations of acetoacetate (0.23 ± 0.02vs 0.05 ± 0.00, P 〈 0.01), and b-hydroxybutarate (0.58± 0.14 vs 0.08 ± 0.00, P 〈 0.01), lower concentrationsof 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) andarginine (0.08 ± 0.01 vs 0.14 ± 0.02, P 〈 0.03) andhigher concentrations of glutamate (1.36 ± 0.25 vs0.58 ± 0.04, P 〈 0.01), lactate (1

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

    DEFF Research Database (Denmark)

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

    2006-01-01

    the 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......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 anisole (1) causes only small positive changes of 1H NMR chemical shifts (Delta delta Hmeta > Hpara, the experimental O-methylation induced shifts in ortho-disubstituted phenols are largest for Hpara, Delta delta equals; 0.19 +/- 0.02 ppm (n = 11...

  7. The importance of 1H-nuclear magnetic resonance spectroscopy for reference standard validation in analytical sciences.

    Directory of Open Access Journals (Sweden)

    Dovi Kelman

    Full Text Available This paper highlights the importance of recording at least a (1H nuclear magnetic resonance (NMR spectrum to verify identity of standards used in analyses of organic materials irrespective of source. We show the importance of this approach with an example of a quantitative high-performance liquid chromatography (HPLC study undertaken with green tea extracts that required the use of several polyphenols as standards. In the course of the study one of these standards [(--epigallocatechin, EGC], although having the physical appearance and appropriate HPLC chromatographic behavior of EGC, proved by (1H-NMR to be a completely different class of molecule. For us, this raised significant questions concerning validity of many published pieces of research that used quantitative HPLC methods without first performing rigorous validation of the employed standards prior to their use. This paper clearly illustrates the importance of validation of all standards used in analysis of organic materials by recording at least a (1H-NMR spectrum of them prior to their use.

  8. Binding of thiocyanate to lactoperoxidase: 1H and 15N nuclear magnetic resonance studies

    Energy Technology Data Exchange (ETDEWEB)

    Modi, S.; Behere, D.V.; Mitra, S. (Tata Institute of Fundamental Research, Bombay (India))

    1989-05-30

    The binding of thiocyanate to lactoperoxidase (LPO) has been investigated by 1H and 15N NMR spectroscopy. 1H NMR of LPO shows that the major broad heme methyl proton resonance at about 61 ppm is shifted upfield by addition of the thiocyanate, indicating binding of the thiocyanate to the enzyme. The pH dependence of line width of 15N resonance of SC15N- in the presence of the enzyme has revealed that the binding of the thiocyanate to the enzyme is facilitated by protonation of an ionizable group (with pKa of 6.4), which is presumably distal histidine. Dissociation constants (KD) of SC15N-/LPO, SC15N-/LPO/I-, and SC15N-/LPO/CN- equilibria have been determined by 15N T1 measurements and found to be 90 +/- 5, 173 +/- 20, and 83 +/- 6 mM, respectively. On the basis of these values of KD, it is suggested that the iodide ion inhibits the binding of the thiocyanate but cyanide ion does not. The thiocyanate is shown to bind at the same site of LPO as iodide does, but the binding is considerably weaker and is away from the ferric ion. The distance of 15N of the bound thiocyanate ion from the iron is determined to be 7.2 +/- 0.2 A from the 15N T1 measurements.

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

    Science.gov (United States)

    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.

  10. Mild hydration of didecyldimethylammonium chloride modified DNA by 1H-nuclear magnetic resonance and by sorption isotherm

    Science.gov (United States)

    Harańczyk, H.; Kobierski, J.; Nizioł, J.; Hebda, E.; Pielichowski, J.; Zalitacz, D.; Marzec, M.; El-Ghayoury, A.

    2013-01-01

    The gaseous phase hydration of deoxyribonucleic acid and didecyldimethylammonium chloride (C19H42ClN) complexes (DNA-DDCA) was observed using hydration kinetics, sorption isotherm, and high power nuclear magnetic resonance. Three bound water fractions were distinguished: (i) a very tightly bound water not removed by incubation over silica gel, (ii) a tightly bound water saturating with the hydration time t1h = (0.59 ± 0.04) h, and a loosely bound water fraction, (iii) with the hydration time t2h = (20.9 ± 1.3) h. Proton free induction decay was decomposed into the signal associated with the solid matrix of DNA-DDCA complex (T2S∗≈ 30 μs) and two liquid signal components coming from tightly bound (T2L1∗≈ 100 μs) and from loosely bound water fraction (T2L2∗≈ 1000 μs).

  11. 1H nuclear magnetic resonance-based metabolomics reveals sex-specific metabolic changes of gastrodin intervention in rats

    Institute of Scientific and Technical Information of China (English)

    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.

  12. Fingerprinting Analysis of Rhizoma Chuanxiong of Commercial Types using 1H Nuclear Magnetic Resonance Spectroscopy and High Performance Liquid Chromatography Method

    Institute of Scientific and Technical Information of China (English)

    Hai-Lin Qin; An-Jun Deng; Guan-Hua Du; Peng Wang; Jin-Lan Zhang; Zhi-Hong Li

    2009-01-01

    The 1H nuclear magnetic resonance (1H NMR) fingerprints of fractionated non-polar extracts (control substance for a plant drug (CSPD) A) from Rhizoma chuanxiong, the rhizomes of Ligusticum chuanxiong Hort., of seven specimens from different sources were measured on Fourier Transform (FT)-NMR spectrometer and assigned by comparing them with the 1H NMR spectra of the isolated pure compounds. The 1H NMR fingerprints showed exclusively characteristic resonance signals of the major special constituents of the plant. Although the differences in the relative intensity of the 1H NMR signals due to a discrepancy in the ratio of the major constituents among these samples could be confirmed by high performance liquid chromatography analysis, the general features of the 1H NMR fingerprint established for an authentic sample of the rhizomes of L. chuanxiong exhibited exclusive data from those special compounds and can be used for authenticating L. Chuanxiong species.

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

    Science.gov (United States)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  15. (1)H-Nuclear magnetic resonance-based metabolic profiling of nonsteroidal anti-inflammatory drug-induced adverse effects in rats.

    Science.gov (United States)

    Um, So Young; Park, Jung Hyun; Chung, Myeon Woo; Choi, Ki Hwan; Lee, Hwa Jeong

    2016-09-10

    Nonsteroidal anti-inflammatory drugs (NSAIDs), which are globally prescribed, exhibit mainly anti-inflammatory and analgesic effects but also can cause adverse effects including gastrointestinal erosions, ulceration, bleeding, and perforation. The purpose of this study was to investigate surrogate biomarkers associated with the gastrointestinal (GI) damage caused by NSAID treatment using pattern recognition analysis of (1)H-nuclear magnetic resonance ((1)H NMR) spectra of rat urine. Urine was collected for 5h after oral administration of the following NSAIDs at low or high doses: acetylsalicylic acid (10 or 200mgkg(-1)), diclofenac (0.5 or 15mgkg(-1)), piroxicam (1 or 10mgkg(-1)), indomethacin (1 or 25mgkg(-1)), or ibuprofen (10, or 150mgkg(-1)) as nonselective COX inhibitors and celecoxib (10 or 100mgkg(-1)) as a COX-2 selective inhibitor. The urine was analyzed using 500MHz (1)H NMR for spectral binning and targeted profiling and the level of gastric damage was examined. The nonselective COX inhibitors caused severe gastric damage while no lesions were observed in the celecoxib-treated rats. The (1)H NMR urine spectra were divided into spectral bins (0.04ppm) for global profiling, and a total of 44 endogenous metabolites were assigned for targeted profiling. Multivariate data analyses were performed to recognize the spectral pattern of endogenous metabolites related to NSAIDs using partial least square-discrimination analysis (PLS-DA). The (1)H NMR spectra clustered differently according to gastric damage score in global profiling. In targeted profiling, the endogenous metabolites of citrate, allantoin, 2-oxoglutarate, acetate, benzoate, glycine, and trimethylamine N-oxide were selected as putative biomarkers for gastric damage caused by NSAIDs. These putative biomarkers might be useful for predicting the risk of adverse effects caused by NSAIDs in the early stage of drug development process.

  16. Metabonomic Analysis of Water Extracts from Different Angelica Roots by 1H-Nuclear Magnetic Resonance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Pui Hei Chan

    2014-03-01

    Full Text Available Angelica Radix, the roots of the genus Angelica, has been used for more than 2,000 years as a traditional medicine in Eastern Asia. The Chinese Pharmacopoeia records more than 100 herbal formulae containing Angelica roots. There are two common sources of Angelica roots, Angelica sinensis from China and A. gigas from Korea. The two species of Angelica roots differ in their chemical compositions, pharmacological properties and clinical efficacy. 1H-NMR metabolic profiling has recently emerged as a promising quality control method for food and herbal chemistry. We explored the use of 1H-NMR metabolic profiling for the quality control of Angelica Radix. Unlike previous work, we performed the metabolic profiling on hot water extracts, so as to mimic the clinically relevant preparation method. Unsupervised principle component analyses of both the full spectral profile and a selection of targeted molecules revealed a clear differentiation of three types of Angelica roots. In addition, the levels of 13 common metabolites were measured. Statistically significant differences in the levels of glucose, fructose and threonine were found between different sources of Angelica. Ferulic acid, a marker commonly used to evaluate Angelica root, was detected in our samples, but the difference in ferulic acid levels between the samples was not statistically significant. Overall, we successfully applied 1H-NMR metabolic profiling with water extraction to discriminate all three sources of Angelica roots, and obtained quantitative information of many common metabolites.

  17. Identification and quantification by (1)H nuclear magnetic resonance spectroscopy of seven plasticizers in PVC medical devices.

    Science.gov (United States)

    Genay, Stéphanie; Feutry, Frédéric; Masse, Morgane; Barthélémy, Christine; Sautou, Valérie; Odou, Pascal; Décaudin, Bertrand; Azaroual, Nathalie

    2017-02-01

    Medical devices are generally made of polyvinyl chloride plasticized by six authorized plasticizers as alternatives to di-(2-ethylhexyl)-phthalate (DEHP) classified as reprotoxic class 1b. These are acetyl tri-n-butyl citrate (ATBC), di-(2-ethylhexy) adipate (DEHA), di-(2-ethylhexyl) terephthalate (DEHT), di-isononyl cyclohexane-1,2-dicarboxylate (DINCH), di-isononyl phthalate (DINP), and tri-octyl trimellitate (TOTM). The main objective of this study was to propose a new method using (1)H NMR spectroscopy to determine and quantify these seven plasticizers in PVC sheets, standard infusion tubings, and commercially available medical devices. Two techniques were compared: dissolution in deuterated tetrahydrofuran and extraction by deuterated chloroform. Plasticizer (1)H NMR spectra were very similar in both deuterated solvents; dissolution and extraction provided similar results. The sensitivity of this method enabled us to detect and quantify the presence of minor plasticizers in PVC. In nine commercially available samples, the major plasticizer was identified and quantified by (1)H NMR. In six samples, one, two, or three minor plasticizers were identified and also quantified. DEHP was detected in only one tubing. NMR is therefore very convenient for studying plasticizers contained in medical devices. Only small quantities of solvents and sample are required. It is not necessary to dilute samples to enter a quantification range, and it is sufficiently sensitive to detect contaminants.

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

    LENUS (Irish Health Repository)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Soybean biodiesel methyl esters, free glycerin and acid number quantification by 1H nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Coral, Natasha; Rodrigues, Elizabeth; Rumjanek, Victor; Zamian, José Roberto; da Rocha Filho, Geraldo Narciso; da Costa, Carlos Emmerson Ferreira

    2013-02-01

    Production of alternative fuels, such as biodiesel, from transesterification of vegetable oil driven by heterogeneous catalysts is a promising alternative to fossil diesel. However, achieving a successful substitution for a new renewable fuel depends on several quality parameters. (1)H NMR spectroscopy was used to determine the amount of methyl esters, free glycerin and acid number in the transesterification of soybean oil with methanol in the presence of hydrotalcite-type catalyst to produce biodiesel. Reaction parameters, such as temperature and time, were used to evaluate soybean oil methyl esters rate conversion. Temperatures of 100 to 180 °C and times of 20 to 240 min were tested on a 1 : 12 molar ratio soybean oil/methanol reaction. At 180 °C/240 min conditions, a rate of 94.5 wt% of methyl esters was obtained, where free glycerin and free fatty acids were not detected.

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

    Science.gov (United States)

    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.

  2. Urinary (1)H Nuclear Magnetic Resonance Metabolomic Fingerprinting Reveals Biomarkers of Pulse Consumption Related to Energy-Metabolism Modulation in a Subcohort from the PREDIMED study.

    Science.gov (United States)

    Madrid-Gambin, Francisco; Llorach, Rafael; Vázquez-Fresno, Rosa; Urpi-Sarda, Mireia; Almanza-Aguilera, Enrique; Garcia-Aloy, Mar; Estruch, Ramon; Corella, Dolores; Andres-Lacueva, Cristina

    2017-04-07

    Little is known about the metabolome fingerprint of pulse consumption. The study of robust and accurate biomarkers for pulse dietary assessment has great value for nutritional epidemiology regarding health benefits and their mechanisms. To characterize the fingerprinting of dietary pulses (chickpeas, lentils, and beans), spot urine samples from a subcohort from the PREDIMED study were stratified using a validated food frequency questionnaire. Urine samples of nonpulse consumers (≤4 g/day of pulse intake) and habitual pulse consumers (≥25 g/day of pulse intake) were analyzed using a (1)H nuclear magnetic resonance (NMR) metabolomics approach combined with multi- and univariate data analysis. Pulse consumption showed differences through 16 metabolites coming from (i) choline metabolism, (ii) protein-related compounds, and (iii) energy metabolism (including lower urinary glucose). Stepwise logistic regression analysis was applied to design a combined model of pulse exposure, which resulted in glutamine, dimethylamine, and 3-methylhistidine. This model was evaluated by a receiver operating characteristic curve (AUC > 90% in both training and validation sets). The application of NMR-based metabolomics to reported pulse exposure highlighted new candidates for biomarkers of pulse consumption and the impact on energy metabolism, generating new hypotheses on energy modulation. Further intervention studies will confirm these findings.

  3. 360-MHz 1H nuclear-magnetic-resonance spectroscopy of sialyl-oligosaccharides from patients with sialidosis (mucolipidosis I and II)

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Dorland, L.; Haverkamp, J.; Strecker, G.; Michalski, J.-C.; Fournet, b.; Spik, G.; Montreuil, J.

    1978-01-01

    360-MHz proton nuclear magnetic resonance spectra were recorded of 10 sialyl-oligosaccharides isolated form urine of sialidosis patients. Their structures are related to the complex aspareagine-linked glydan chains of glycoproteins. By correlation of these spectra and comparison with spectra of refe

  4. Observation of 1H-13C and 1H-1H proximities in a paramagnetic solid by NMR at high magnetic field under ultra-fast MAS

    Science.gov (United States)

    Li, Shenhui; Trébosc, Julien; Lafon, Olivier; Zhou, Lei; Shen, Ming; Pourpoint, Frédérique; Amoureux, Jean-Paul; Deng, Feng

    2015-02-01

    The assignment of NMR signals in paramagnetic solids is often challenging since: (i) the large paramagnetic shifts often mask the diamagnetic shifts specific to the local chemical environment, and (ii) the hyperfine interactions with unpaired electrons broaden the NMR spectra and decrease the coherence lifetime, thus reducing the efficiency of usual homo- and hetero-nuclear NMR correlation experiments. Here we show that the assignment of 1H and 13C signals in isotopically unmodified paramagnetic compounds with moderate hyperfine interactions can be facilitated by the use of two two-dimensional (2D) experiments: (i) 1H-13C correlations with 1H detection and (ii) 1H-1H double-quantum ↔ single-quantum correlations. These methods are experimentally demonstrated on isotopically unmodified copper (II) complex of L-alanine at high magnetic field (18.8 T) and ultra-fast Magic Angle Spinning (MAS) frequency of 62.5 kHz. Compared to 13C detection, we show that 1H detection leads to a 3-fold enhancement in sensitivity for 1H-13C 2D correlation experiments. By combining 1H-13C and 1H-1H 2D correlation experiments with the analysis of 13C longitudinal relaxation times, we have been able to assign the 1H and 13C signals of each L-alanine ligand.

  5. Bulk magnetization and {sup 1}H NMR spectra of magnetically heterogeneous model systems

    Energy Technology Data Exchange (ETDEWEB)

    Levin, E.M., E-mail: levin@iastate.edu [Division of Materials Sciences and Engineering, Ames Laboratory of US DOE (United States); Department of Physics and Astronomy, Iowa State University, Iowa, IA 50011-3020 (United States); Bud' ko, S.L. [Division of Materials Sciences and Engineering, Ames Laboratory of US DOE (United States); Department of Physics and Astronomy, Iowa State University, Iowa, IA 50011-3020 (United States)

    2011-10-15

    Bulk magnetization and {sup 1}H static and magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of two magnetically heterogeneous model systems based on laponite (LAP) layered silicate or polystyrene (PS) with low and high proton concentration, respectively, and ferrimagnetic Fe{sub 2}O{sub 3} nano- or micro-particles have been studied. In LAP+Fe{sub 2}O{sub 3}, a major contribution to the NMR signal broadening is due to the dipolar coupling between the magnetic moments of protons and magnetic particles. In PS+Fe{sub 2}O{sub 3}, due to the higher proton concentration in polystyrene and stronger proton-proton dipolar coupling, an additional broadening is observed, i.e. {sup 1}H MAS NMR spectra of magnetically heterogeneous systems are sensitive to both proton-magnetic particles and proton-proton dipolar couplings. An increase of the volume magnetization by {approx}1 emu/cm{sup 3} affects the {sup 1}H NMR signal width in a way that is similar to an increase of the proton concentration by {approx}2x10{sup 22}/cm{sup 3}. {sup 1}H MAS NMR spectra, along with bulk magnetization measurements, allow the accurate determination of the hydrogen concentration in magnetically heterogeneous systems. - Highlights: > {sup 1}H NMR and magnetization allow study of dipolar interactions in magnetically heterogeneous systems. > Both the proton-proton and proton-magnetic particle dipolar interactions affect {sup 1}H NMR spectra. > {sup 1}H NMR and magnetization can be used for the accurate determination of the hydrogen concentration.

  6. 1H nuclear magnetic resonance study of low-temperature water dynamics in a water-soaked perfluorosulfonic acid ionomer Nafion film

    Science.gov (United States)

    Han, Jun Hee; Lee, Kyu Won; Lee, Cheol Eui

    2017-01-01

    We have employed proton nuclear magnetic resonance (NMR) spectroscopy in order to study the low-temperature water dynamics in a water-soaked perfluorosulfonic acid ionomer Nafion (NR-211) film. According to the recent models, Nafion may comprise water strongly bound to the sulfonic acid group, hydration water, and condensed water species. In this work, three separate NMR peaks from the water species revealing distinct behaviors were identified. A significant portion of the "bound" water remained unfrozen down to 200 K, whereas a slow-to-fast motional limit transition was observed at TM=220 K from the relaxation measurements.

  7. 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

    Directory of Open Access Journals (Sweden)

    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.

  8. Bulk magnetization and 1H NMR spectra of magnetically heterogeneous model systems

    Science.gov (United States)

    Levin, E. M.; Bud'ko, S. L.

    2011-10-01

    Bulk magnetization and 1H static and magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of two magnetically heterogeneous model systems based on laponite (LAP) layered silicate or polystyrene (PS) with low and high proton concentration, respectively, and ferrimagnetic Fe2O3 nano- or micro-particles have been studied. In LAP+Fe2O3, a major contribution to the NMR signal broadening is due to the dipolar coupling between the magnetic moments of protons and magnetic particles. In PS+Fe2O3, due to the higher proton concentration in polystyrene and stronger proton-proton dipolar coupling, an additional broadening is observed, i.e. 1H MAS NMR spectra of magnetically heterogeneous systems are sensitive to both proton-magnetic particles and proton-proton dipolar couplings. An increase of the volume magnetization by ∼1 emu/cm3 affects the 1H NMR signal width in a way that is similar to an increase of the proton concentration by ∼2×1022/cm3. 1H MAS NMR spectra, along with bulk magnetization measurements, allow the accurate determination of the hydrogen concentration in magnetically heterogeneous systems.

  9. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-02-01

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

  11. Primary and secondary biomass burning aerosols determined by proton nuclear magnetic resonance (1H-NMR) spectroscopy during the 2008 EUCAARI campaign in the Po Valley (Italy)

    Science.gov (United States)

    Paglione, M.; Saarikoski, S.; Carbone, S.; Hillamo, R.; Facchini, M. C.; Finessi, E.; Giulianelli, L.; Carbone, C.; Fuzzi, S.; Moretti, F.; Tagliavini, E.; Swietlicki, E.; Eriksson Stenström, K.; Prévôt, A. S. H.; Massoli, P.; Canaragatna, M.; Worsnop, D.; Decesari, S.

    2014-05-01

    Atmospheric organic aerosols are generally classified as primary and secondary (POA and SOA) according to their formation processes. An actual separation, however, is challenging when the timescales of emission and gas-to-particle formation overlap. The presence of SOA formation in biomass burning plumes leads to scientific questions about whether the oxidized fraction of biomass burning aerosol is rather of secondary or primary origin, as some studies would suggest, and about the chemical compositions of oxidized biomass burning POA and SOA. In this study, we apply nuclear magnetic resonance (NMR) spectroscopy to investigate the functional group composition of fresh and aged biomass burning aerosols during an intensive field campaign in the Po Valley, Italy. The campaign was part of the EUCAARI project and was held at the rural station of San Pietro Capofiume in spring 2008. Factor analysis applied to the set of NMR spectra was used to apportion the wood burning contribution and other organic carbon (OC) source contributions, including aliphatic amines. Our NMR results, referred to the polar, water-soluble fraction of OC, show that fresh wood burning particles are composed of polyols and aromatic compounds, with a sharp resemblance to wood burning POA produced in wood stoves, while aged samples are clearly depleted of alcohols and are enriched in aliphatic acids with a smaller contribution of aromatic compounds. The comparison with biomass burning organic aerosols (BBOA) determined by high-resolution aerosol mass spectrometry (HR-TOF-AMS) at the site shows only a partial overlap between NMR BB-POA and AMS BBOA, which can be explained by either the inability of BBOA to capture all BB-POA composition, especially the alcohol fraction, or the fact that BBOA account for insoluble organic compounds unmeasured by the NMR. Therefore, an unambiguous composition for biomass burning POA could not be derived from this study, with NMR analysis indicating a higher O / C ratio

  12. New structural information on a humic acid from two-dimensional 1H-13C correlation solid-state nuclear magnetic resonance.

    Science.gov (United States)

    Mao, J D; Xing, B; Schmidt-Rohr, K

    2001-05-15

    New information on the chemical structure of a peat humic acid has been obtained using a series of two-dimensional 1H-13C heteronuclear correlation solid-state NMR (HETCOR) experiments with different contact times and with spectral editing by dipolar dephasing and 13C transverse relaxation filtering. Carbon-bonded methyl groups (C-CH3) are found to be near both aliphatic and O-alkyl but not aromatic groups. The spectra prove that most OCH3 groups are connected directly with the aromatic rings, as is typical in lignin. As a result, about one-third of the aromatic C-O groups is not phenolic C-OH but C-OCH3. Both protonated and unprotonated anomeric O-C-O carbons are identified in the one- and two-dimensional spectra. COO groups are found predominantly in OCHn-COO environments, but some are also bonded to aromatic rings and aliphatic groups. All models of humic acids in the literature lack at least some of the features observed here. Compositional heterogeneity was studied by introducing 1H spin diffusion into the HETCOR experiment. Comparison with data for a synthetic polymer, polycarbonate, indicates that the separation between O-alkyl and aromatic groups in the humic acid is less than 1.5 nm. However, transverse 13C relaxation filtering under 1H decoupling reveals heterogeneity on a nanometer scale, with the slow-relaxing component being rich in lignin-like aromatic-C-O-CH3 moieties and poor in COO groups.

  13. Arsenic-boron derivatives. Part 5. A /sup 1/H and /sup 11/B nuclear magnetic resonance study of the methylated arsine adducts of boron trihalides

    Energy Technology Data Exchange (ETDEWEB)

    Chehayber, J.M.; Drake, J.E.

    1986-02-17

    The /sup 1/H NMR chemical shifts for the adduct series (CH/sub 3/)/sub n/AsH/sub 3-n/BX/sub 3/ and the /sup 11/B NMR chemical shifts for the adduct series (CH/sub 3/)/sub n/AsH/sub 3-n/BX/sub 3/, (CH/sub 3/)/sub n/AsH/sub 3-n/BX/sub 2/Y and (CH/sub 3/)/sub n/AsH/sub 3-n/BXYZ (where n=1, 2, 3; Xnot =Ynot =Z=Cl, Br or I) have been reported. The values of the chemical shifts are examined in view of their use as indicators of acid-base strength. The /sup 11/B chemical shifts were found to fit Malinowsky's criteria of pairwise additivity.

  14. Liquid chromatography "on-flow" 1H nuclear magnetic resonance on native glycosphingolipid mixtures together with gas chromatography/mass spectrometry on the released oligosaccharides for screening and characterisation of carbohydrate-based antigens from pig lungs.

    Science.gov (United States)

    Bäcker, A E; Thorbert, S; Rakotonirainy, O; Hallberg, E C; Olling, A; Gustavsson, M; Samuelsson, B E; Soussi, B

    1999-01-01

    Glycosphingolipids were prepared from pig lung and pooled into two fractions with (i) or = 3 sugar residues. Oligosaccharides were prepared and used for gas chromatography, gas chromatography/mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry. The glycolipid fractions i and ii were further characterised and purified using a novel method based on high performance liquid chromatography "on-flow" proton nuclear magnetic resonance. The LC "on-flow" NMR technique showed good chromatographic separation and gave NMR spectral information which could be used as guidance for pooling of the separated mixture glycolipids. Conventional 1H NMR, thin layer immunostaining, gas chromatography, gas chromatography/mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry were used to characterise the glycolipids and to validate LC-NMR spectral data.

  15. Common Degradative Pathways of Morpholine, Thiomorpholine, and Piperidine by Mycobacterium aurum MO1: Evidence from 1H-Nuclear Magnetic Resonance and Ionspray Mass Spectrometry Performed Directly on the Incubation Medium

    Science.gov (United States)

    Combourieu, Bruno; Besse, Pascale; Sancelme, Martine; Godin, Jean-Philippe; Monteil, André; Veschambre, Henri; Delort, Anne-Marie

    2000-01-01

    In order to see if the biodegradative pathways for morpholine and thiomorpholine during degradation by Mycobacterium aurum MO1 could be generalized to other heterocyclic compounds, the degradation of piperidine by this strain was investigated by performing 1H-nuclear magnetic resonance directly with the incubation medium. Ionspray mass spectrometry, performed without purification of the samples, was also used to confirm the structure of some metabolites during morpholine and thiomorpholine degradation. The results obtained with these two techniques suggested a general pathway for degradation of nitrogen heterocyclic compounds by M. aurum MO1. The first step of the degradative pathway is cleavage of the C—N bond; this leads formation of an intermediary amino acid, which is followed by deamination and oxidation of this amino acid into a diacid. Except in the case of thiodiglycolate obtained from thiomorpholine degradation, the dicarboxylates are completely mineralized by the bacterial cells. A comparison with previously published data showed that this pathway could be a general pathway for degradation by other strains of members of the genus Mycobacterium. PMID:10919768

  16. Nuclear receptor NR1H3 in familial multiple sclerosis

    Science.gov (United States)

    Wang, Zhe; Sadovnick, A. Dessa; Traboulsee, Anthony L.; Ross, Jay P.; Bernales, Cecily Q.; Encarnacion, Mary; Yee, Irene M.; de Lemos, Madonna; Greenwood, Talitha; Lee, Joshua D.; Wright, Galen; Ross, Colin J.; Zhang, Si; Song, Weihong; Vilariño-Güell, Carles

    2016-01-01

    SUMMARY Multiple sclerosis (MS) is an inflammatory disease characterized by myelin loss and neuronal dysfunction. Despite the aggregation observed in some families, pathogenic mutations have remained elusive. In this study we describe the identification of NR1H3 p.Arg415Gln in seven MS patients from two multi-incident families presenting severe and progressive disease, with an average age at onset of 34 years. Additionally, association analysis of common variants in NR1H3 identified rs2279238 conferring a 1.35-fold increased risk of developing progressive MS. The p.Arg415Gln position is highly conserved in orthologs and paralogs, and disrupts NR1H3 heterodimerization and transcriptional activation of target genes. Protein expression analysis revealed that mutant NR1H3 (LXRA) alters gene expression profiles, suggesting a disruption in transcriptional regulation as one of the mechanisms underlying MS pathogenesis. Our study indicates that pharmacological activation of LXRA or its targets may lead to effective treatments for the highly debilitating and currently untreatable progressive phase of MS. PMID:27253448

  17. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  18. Bulk magnetization and 1H NMR spectra of magnetically heterogeneous model systems

    Energy Technology Data Exchange (ETDEWEB)

    Levin, E M; Bud& #x27; ko, S L

    2011-04-28

    Bulk magnetization and ¹H static and magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of two magnetically heterogeneous model systems based on laponite (LAP) layered silicate or polystyrene (PS) with low and high proton concentration, respectively, and ferrimagnetic Fe₂O₃ nano- or micro-particles have been studied. In LAP+Fe₂O₃, a major contribution to the NMR signal broadening is due to the dipolar coupling between the magnetic moments of protons and magnetic particles. In PS+Fe₂O₃, due to the higher proton concentration in polystyrene and stronger proton–proton dipolar coupling, an additional broadening is observed, i.e. ¹H MAS NMR spectra of magnetically heterogeneous systems are sensitive to both proton–magnetic particles and proton–proton dipolar couplings. An increase of the volume magnetization by ~1 emu/cm³ affects the ¹H NMR signal width in a way that is similar to an increase of the proton concentration by ~2×10²²/cm³. ¹H MAS NMR spectra, along with bulk magnetization measurements, allow the accurate determination of the hydrogen concentration in magnetically heterogeneous systems.

  19. Nuclear magnetic resonance, fluorescence correlation spectroscopy and time-resolved fluorescence anisotropy studies of intermolecular interactions in bis(1-methyl-1H-imidazol-3-ium-3-yl)dihydroborate bis(trifluoromethylsulfonyl)amide and its mixtures with various cosolvents

    Science.gov (United States)

    Sahu, Prabhat Kumar; Nanda, Raju; Seth, Sudipta; Ghosh, Arindam; Sarkar, Moloy

    2016-09-01

    Keeping in mind the potential usefulness of mixed ionic liquid (IL)-cosolvents systems in several industrial applications, intermolecular interactions between a borate-based IL, bis(1-methyl-1H-imidazol-3-ium-3-yl)dihydroborate bis(trifluoromethylsulfonyl)amide ([BIMIMDBA][TF2N]), and its binary mixtures with several molecular solvents has been investigated through NMR and fluorescence spectroscopy. Analysis of the 1H chemical shifts (δ/ppm) and translational diffusion coefficients (D) of the IL in different solvent mixtures demonstrate interplay of nonspecific (ion-dipole) and specific (hydrogen bonding) interactions in governing the properties of these mixtures. Fluorescence correlation spectroscopy (FCS) and time-resolved fluorescence anisotropy data provide evidence in favour of different IL-solvent interaction for different IL-cosolvent systems.

  20. 23Na and 1H NMR Relaxometry of Shale at High Magnetic Field

    CERN Document Server

    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...

  1. GHz nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-12-01

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

  2. 葵花籽油热氧化过程的1H-NMR指纹图谱与LF-NMR弛豫特性研究%1H Nuclear Magnetic Resonance (NMR) Fingerprints and Low-Field-NMR Relaxation Properties of Sunflower Oil during Thermal Oxidation

    Institute of Scientific and Technical Information of China (English)

    卢海燕; 王欣; 赵婷婷; 刘宝林

    2014-01-01

    论文应用1H-NMR研究了葵花籽油65℃贮藏过程中氧化产物(共轭烯、醛类、氧化物、芳香烃、游离酸相对含量)的变化规律,并与低场核磁共振(LF-NMR)弛豫特性中的S21的变化进行了相关性分析.1H-NMR结果表明,在65℃贮藏过程中,油样的初级氧化产物随贮藏时间的延长呈先增加后减小的趋势,与氢过氧化物相比,氢过氧化物-共轭二烯优先降解;次级氧化产物及水解产物如醛、环氧化物、游离脂肪酸等随贮藏时间呈良好指数关系(R2>0.96),芳香烃则随贮藏时间呈先增加后减小的趋势.而LF-NMR检测所得到的油样的S21随贮藏时间延长呈良好的指数增加趋势(R2=0.99).相关性分析表明,氧化物、游离脂肪酸与S21的相关性最高,模型验证合理可靠.该结果可为研究S21特征峰的表征物质、提高LF-NMR油脂品质判别率提供研究参考及有益思路.

  3. Nuclear Magnetic Resonance Gyroscope

    Science.gov (United States)

    Larsen, Michael; Griffith, Robert; Bulatowicz, Michael

    2014-03-01

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

  4. 1H and 15N Dynamic Nuclear Polarization Studies of Carbazole

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian Zhi; Solum, Mark S.; Wind, Robert A.; Nilsson, Brad L.; Peterson, Matt A.; Pugmire, Ronald J.; Grant, David M.

    2000-01-01

    15N NMR experiments, combined with dynamic nuclear polarization (DNP), are reported on carbazole doped with the stable free radical 1,3 bisdiphenylene-2 phenylally1 (BDPA). Doping shortens the nuclear relaxation times and provides paramagnetic centers that can be used to enhance the nuclear signal by means of DNP so that 15 N NMR experiments can be done in minutes. The factors were measured in a 1.4 T external field, using both unlabeled and 98% 15N labeled carbazole with doping levels varying between 0.65 and 5.0 wt % BDPA. A doping level of approximately 1 wt % produced optimal results. DNP enhancement factors of 35 and 930 were obtained for 1H and 15N, respectively making it possible to perform 15N DNP NMR experiments at the natural abundance level.

  5. Lateral diffusion of PEG-Lipid in magnetically aligned bicelles measured using stimulated echo pulsed field gradient 1H NMR.

    Science.gov (United States)

    Soong, Ronald; Macdonald, Peter M

    2005-01-01

    Lateral diffusion measurements of PEG-lipid incorporated into magnetically aligned bicelles are demonstrated using stimulated echo (STE) pulsed field gradient (PFG) proton (1H) nuclear magnetic resonance (NMR) spectroscopy. Bicelles were composed of dimyristoyl phosphatidylcholine (DMPC) plus dihexanoyl phosphatidylcholine (DHPC) (q = DMPC/DHPC molar ratio = 4.5) plus 1 mol % (relative to DMPC) dimyristoyl phosphatidylethanolamine-N-[methoxy(polyethylene glycol)-2000] (DMPE-PEG 2000) at 25 wt % lipid. 1H NMR STE spectra of perpendicular aligned bicelles contained only resonances assigned to residual HDO and to overlapping contributions from a DMPE-PEG 2000 ethoxy headgroup plus DHPC choline methyl protons. Decay of the latter's STE intensity in the STE PFG 1H NMR experiment (g(z) = 244 G cm(-1)) yielded a DMPE-PEG 2000 (1 mol %, 35 degrees C) lateral diffusion coefficient D = 1.35 x 10(-11) m2 s(-1). Hence, below the "mushroom-to-brush" transition, DMPE-PEG 2000 lateral diffusion is dictated by its DMPE hydrophobic anchor. D was independent of the diffusion time, indicating unrestricted lateral diffusion over root mean-square diffusion distances of microns, supporting the "perforated lamellae" model of bicelle structure under these conditions. Overall, the results demonstrate the feasibility of lateral diffusion measurements in magnetically aligned bicelles using the STE PFG NMR technique.

  6. Increasing 14N NQR signal by 1H-14N level crossing with small magnetic fields.

    Science.gov (United States)

    Thurber, Kent R; Sauer, Karen L; Buess, Michael L; Klug, Christopher A; Miller, Joel B

    2005-11-01

    NQR detection of materials, such as TNT, is hindered by the low signal-to-noise ratio at low NQR frequencies. Sweeping small (0-26 mT) magnetic fields to shift the (1)H NMR frequency relative to the (14)N NQR frequencies can provide a significant increase of the (14)N NQR signal-to-noise ratio. Three effects of (1)H-(14)N level crossing are demonstrated in diglycine hydrochloride and TNT. These effects are (1) transferring (1)H polarization to one or more of the (14)N transitions, including the use of an adiabatic flip of the (1)H polarization during the field sweep, (2) shortening the effective (14)N T(1) by the interaction of (1)H with the (14)N transitions, (3) "level transfer" effect where the third (14)N (spin 1) energy level or other (14)N sites with different NQR frequency are used as a reservoir of polarization which is transferred to the measured (14)N transition by the (1)H. The (14)N NQR signal-to-noise ratio can be increased by a factor of 2.5 for one (14)N site in diglycine hydrochloride (and 2.2 in TNT), even though the maximum (1)H frequency used in this work, 111 6 kHz, is only 30% larger than the measured (14)N frequencies (834 kHz for diglycine hydrochloride and 843 kHz for TNT).

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

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    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.

  9. 19F-{ 1H} Nuclear Overhauser Effect and Proton Decoupling of 5-Fluorouracil and α-Fluoro-β-Alanine

    Science.gov (United States)

    Krems, B.; Bachert, P.; Zabel, H. J.; Lorenz, W. J.

    19F-{ 1H} magnetic double-resonance experiments were performed on model solutions of the antitumor drug 5-fluorouracil (5-FU) and of α-fluoro-β-alanine (FBAL) in order to improve 19F NMR sensitivity for the application in pharmacokinetic studies in vivo. Upon driving the proton spins into saturation, a fluorine signal enhancement (nuclear Overhauser effect) was observed on the order of the theoretical NOE maximum γ H/2γ F, = 53% for purely dipolar coupled 19F- 1H spin systems in extreme narrowing. The dependence of the effect on proton excitation frequency and temporal parameters was measured and cross-relaxation rate constants of 0.07 s -1 (5-FU) and 0.19 s -1 (FBAL) were determined. Irradiation of the proton spin system by a broad pulse during the 19F signal detection period removed FBAL multiplet splittings completely and narrowed the linewidth of this resonance band by a factor of six, Application of proton presaturation in the 19F NMR examination of a patient undergoing 5-FU chemotherapy enhanced the signal-to-noise ratio of the major 5-FU catabolite FBAL detected noninvasively in the liver.

  10. 1H-magnetic resonance spectroscopy of vascular endothelial growth factor-induced neuroprotection following acute cerebral ischemia and reperfusion

    Institute of Scientific and Technical Information of China (English)

    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

  11. Magnetic resonance imaging and {sup 1}H-magnetic resonance spectroscopy in amyotrophic lateral sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Sarchielli, P.; Gallai, V. [Neurological Clinic, Policlinico Monte Luce, Perugia (Italy); Pelliccioli, G.P.; Chiarini, P. [Dept. of Neuroradiology, Azienda Ospedaliera, Perugia (Italy); Tarducci, R.; Presciutti, O.; Gobbi, G. [Dept. of Medical Physics, Azienda Ospedaliera, Perugia (Italy)

    2001-03-01

    We aimed to increase confidence in the combined use of MRI and proton MR spectroscopy ({sup 1}H-MRS) in diagnosis of amyotrophic lateral sclerosis (ALS). We investigated 12 patients with ALS, seven definite and five probable, taking into account clinical measures of motor neuron function. On T2-weighted images we found high signal in the corticospinal tract in six and low signal in the primary motor cortex in seven of the 12 patients. Atrophy of the precentral gyrus was apparent in all the patients apart from one with probable ALS. Absolute quantification of cerebral metabolites using {sup 1}H-MRS demonstrated a significantly lower mean concentration of N-acetylaspartate (NAA) in the precentral gyrus of patients with probable and definite ALS (8.5 {+-} 0.62) than in control subjects (10.4 {+-} 0.71; P < 0.001). NAA concentration in primary motor cortex correlated with Norris scale scores (r = 0.30; P < 0.0001) but not with the ALS Functional Rating Scale score or disease duration. Significantly lower levels of NAA were detected in patients with low signal in the motor cortex than in those without (P < 0.01). Mean choline (Cho) and creatine (Cr) values did not differ between patients with ALS and controls. (orig.)

  12. 1H NMR spectra. Part 30(+): 1H chemical shifts in amides and the magnetic anisotropy, electric field and steric effects of the amide group.

    Science.gov (United States)

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

    2013-03-01

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

  13. 1H magnetic resonance spectroscopy studies on subclinical neurocysticercosis%脑实质囊虫病亚临床期的1H-MRS成像研究

    Institute of Scientific and Technical Information of China (English)

    王青; 张承志; 李信响; 徐鲲; 苏洁

    2016-01-01

    Objective: To evaluate the clinical application of single voxel 1H magnetic resonance spectroscopy in diagnosis of subclinical neurocysticercosis. Materials and Methods: One hundred and ten cases of subclinical neurocysticercosis and 130 cases of cerebral cysticercosis (live worms stage) with contrast enhanced single voxel 1H magnetic resonance spectroscopy were screened for this study. Observation of the change in ratio of the lesions of the subclinical neurocysticercosis and some trace metabolites around the lesions was done. Results: The group of subclinical neurocysticercosis has no significant difference with normal control group in various biochemical metabolites. The ratios of NAA/Cho, Cho/Cr and Lip/Cr have statistical significance in the analysis and evaluation of subclinical neurocysticercosis group and live worms stage group. The ratio of NAA/Cho in subclinical neurocysticercosis group is higher than live worms stage group. The ratios of Cho/Cr and Lip/Cr of the former are lower than that of the latter. The ratios of NAA/Cho and Lip/Cr evaluate the differential diagnosis efficiency between subclinical neurocysticercosis stage and live worms stage on ROC curve. Conclusions: 1H-MRS reveals the changes in characteristics of subclinical neurocysticercosis stage and live worms stage so as to evaluate the corresponding diagnosis index of the ratios of NAA/Cho and Lip/Cr, which are of great value to early diagnosis and treatment of the neurocysticercosis.%目的:应用单体素1H-MRS波谱成像前瞻性研究对其脑实质囊虫病亚临床期的诊断价值。材料与方法筛选110例脑实质囊虫病亚临床期为研究对象,并与130例脑实质囊虫病活虫期为对照,进行单体素1H-MRS波谱成像检查,观测脑实质囊虫(亚临床期)病灶及其周围区域某些微量代谢产物比值的变化,并进行对照评价。结果脑实质囊虫病亚临床期与正常镜像区组各生化代谢物比值结果均无显著性差异

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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".

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

    Science.gov (United States)

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

    1998-11-01

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

  18. Regional age-related effects in the monkey brain measured with 1H magnetic resonance spectroscopy.

    Science.gov (United States)

    Ronen, Itamar; Fan, Xiaoying; Schettler, Steve; Jain, Sahil; Murray, Donna; Kim, Dae-Shik; Killiany, Ronald; Rosene, Douglas

    2011-06-01

    The rhesus monkey is a useful model for examining age-related effects on the brain, because of the extensive neuroanatomical homology between the monkey and the human brain, the tight control for neurological diseases as well as the possibility of obtaining relevant behavioral data and post-mortem tissue for histological analyses. Here, proton magnetic resonance spectroscopy ((1)H-MRS) was used together with high-resolution anatomical MRI images to carefully assess regional concentrations of brain metabolites in a group of 20 rhesus monkeys. In an anterior volume of interest (VOI) that covered frontal and prefrontal areas, significant positive correlations of myo-inositol and of total creatine concentrations with age were detected, whereas N-acetyl aspartate (NAA) and choline compounds (Cho) were not significantly correlated with age. In an occipito-parietal VOI, all metabolites showed no statistically significant age-dependent trend. Strong correlations were found between NAA concentration and gray matter fraction in the VOIs as well as between choline compounds and white matter fraction.

  19. Evanescent Waves Nuclear Magnetic Resonance

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  20. A Classical Approach in Simple Nuclear Fusion Reaction 1H2 + 1H3 using Two-Dimension Granular Molecular Dynamics Model

    CERN Document Server

    Viridi, Sparisoma; Waris, Abdul; Perkasa, Yudha Satya

    2011-01-01

    Molecular dynamics in 2-D accompanied by granular model provides an opportunity to investigate binding between nuclei particles and its properties that arises during collision in a fusion reaction. A fully classical approach is used to observe the influence of initial angle of nucleus orientation to the product yielded by the reaction. As an example, a simplest fusion reaction between 1H2 and 1H3 is observed. Several products of the fusion reaction have been obtained, even the unreported ones, including temporary 2He4 nucleus.

  1. Tunable 13C/1H dual channel matching circuit for dynamic nuclear polarization system with cross-polarization

    DEFF Research Database (Denmark)

    Rybalko, Oleksandr; Bowen, Sean; Zhurbenko, Vitaliy

    2016-01-01

    In this paper we report initial results of design and practical implementation of tuning and matching circuit to estimate a performance of Dynamic Nuclear Polarization (DNP) at a magnetic field of 6.7 T. It is shown that developed circuit for signal observation is compact, easy to make and provides...

  2. Nuclear magnetic ordering in silver

    Energy Technology Data Exchange (ETDEWEB)

    Lefmann, K.

    1995-12-01

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

  3. Evanescent Waves Nuclear Magnetic Resonance.

    Science.gov (United States)

    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.

  4. Introduction to Nuclear Magnetic Resonance

    Science.gov (United States)

    Manatt, Stanley L.

    1985-01-01

    The purpose of this paper is to try to give a short overview of what the status is on nuclear magnetic resonance (NMR). It's a subject where one really has to spend some time to look at the physics in detail to develop a proper working understanding. I feel it's not appropriate to present to you density matrices, Hamiltonians of all sorts, and differential equations representing the motion of spins. I'm really going to present some history and status, and show a few very simple concepts involved in NMR. It is a form of radio frequency spectroscopy and there are a great number of nuclei that can be studied very usefully with the technique. NMR requires a magnet, a r.f. transmitter/receiver system, and a data acquisition system.

  5. Protein dynamics from nuclear magnetic relaxation.

    Science.gov (United States)

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

    2016-05-01

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

  6. 1H magnetic resonance spectroscopy of the brain in paediatrics: The diagnosis of creatine deficiencies

    NARCIS (Netherlands)

    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

  7. Nuclear Magnetic Resonance Imaging of Li-ion Battery

    Directory of Open Access Journals (Sweden)

    D. Ohno

    2010-12-01

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

  8. Detection of inflammatory bowel disease by proton magnetic resonance spectroscopy (1H MRS using an animal model

    Directory of Open Access Journals (Sweden)

    Dolenko Brion

    2007-11-01

    Full Text Available Abstract Background The aim of this study was to analyze the potential of proton magnetic resonance spectroscopy (1H MRS in diagnosing early inflammatory bowel disease (IBD. Methods Thirty male Sprague Dawley rats were fed 2% carrageenan in their diet for either 1 or 2 weeks. 1H MRS was performed ex-vivo on colonic mucosal samples (n = 123 and the spectra were analyzed by a multivariate method of analysis. The results of the multivariate analysis were correlated with histological analysis performed using H & E stain for the presence of inflammation in the samples from each group. Results Multivariate analysis classified the samples in their respective groups with an accuracy of 82%. Our region selection algorithm identified four regions in the spectra as being discriminatory. The metabolites assigned to these regions include creatine, phosphatidylcholine, the -CH2HC= group in fatty acyl chain, and the glycerol backbone of lipids. The differences in concentration of these metabolites in each group offer insight into the biochemical changes occurring during IBD and confer diagnostic potential to 1H MRS as a tool to study colonic inflammation in conjunction with biopsy. Conclusion 1H MRS is a sensitive tool to detect early colonic inflammation in an animal model of IBD.

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

    CERN Document Server

    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...

  10. High-field (9.4 T) ~1H magnetic resonance microscopy of mouse brain

    Institute of Scientific and Technical Information of China (English)

    丁广良; 胡红兵; 李丽云; 叶朝辉

    1997-01-01

    The FLASH and STEAM pulse sequences were used to perform the microimaging and localized spectroscopy of brain of living and dead mice, respectively. The phase-shift presaturation approach was used to sup-press water NMR signal. The experimental results show that the differences in localized spectra and MR images of brain between live and dead mice can be observed by means of magnetic resonance microscopy.

  11. 1H-magnetic resonance spectroscopy screening for animals with acute cerebral infraction suitable for thrombolytic therapy

    Institute of Scientific and Technical Information of China (English)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  14. In vivo (1)H magnetic resonance spectroscopy in young-adult daily marijuana users.

    Science.gov (United States)

    Muetzel, Ryan L; Marjańska, Małgorzata; Collins, Paul F; Becker, Mary P; Valabrègue, Romain; Auerbach, Edward J; Lim, Kelvin O; Luciana, Monica

    2013-01-01

    To date, there has been little work describing the neurochemical profile of young, heavy marijuana users. In this study, we examined 27 young-adult marijuana users and 26 healthy controls using single-voxel magnetic resonance spectroscopy on a 3 T scanner. The voxel was placed in the dorsal striatum, and estimated concentrations of glutamate + glutamine, myo-inositol, taurine + glucose, total choline and total N-acetylaspartate were examined between groups. Therewere no overall group effects, but two metabolites showed group by sex interactions. Lower levels of glutamate + glutamine (scaled to total creatine) were observed in female, but not male, marijuana users compared to controls. Higher levels of myo-inositol were observed in female users compared to female non-users and to males in both groups. Findings are discussed in relation to patterns of corticostriatal connectivity and function, in the context of marijuana abuse.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  17. 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

    Science.gov (United States)

    Fantazzini, Paola; Galassi, Francesca; Bortolotti, Villiam; Brown, Robert J. S.; Vittur, Franco

    2011-06-01

    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 αLt1, 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. Computed distributions for simulated data using observed signal

  18. NUCLEAR MAGNETIC RESONANCE STUDIES OF URANOCENES

    Energy Technology Data Exchange (ETDEWEB)

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

    1979-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  20. Parahydrogen enhanced zero-field nuclear magnetic resonance

    CERN Document Server

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.)

  3. Age-Associated Reduction of Asymmetry in Human Central Auditory Function: A 1H-Magnetic Resonance Spectroscopy Study

    Directory of Open Access Journals (Sweden)

    Xianming Chen

    2013-01-01

    Full Text Available The aim of this study was to investigate the effects of age on hemispheric asymmetry in the auditory cortex after pure tone stimulation. Ten young and 8 older healthy volunteers took part in this study. Two-dimensional multivoxel 1H-magnetic resonance spectroscopy scans were performed before and after stimulation. The ratios of N-acetylaspartate (NAA, glutamate/glutamine (Glx, and γ-amino butyric acid (GABA to creatine (Cr were determined and compared between the two groups. The distribution of metabolites between the left and right auditory cortex was also determined. Before stimulation, left and right side NAA/Cr and right side GABA/Cr were significantly lower, whereas right side Glx/Cr was significantly higher in the older group compared with the young group. After stimulation, left and right side NAA/Cr and GABA/Cr were significantly lower, whereas left side Glx/Cr was significantly higher in the older group compared with the young group. There was obvious asymmetry in right side Glx/Cr and left side GABA/Cr after stimulation in young group, but not in older group. In summary, there is marked hemispheric asymmetry in auditory cortical metabolites following pure tone stimulation in young, but not older adults. This reduced asymmetry in older adults may at least in part underlie the speech perception difficulties/presbycusis experienced by aging adults.

  4. Facile Preparation of a New Gadofullerene-Based Magnetic Resonance Imaging Contrast Agent with High 1H Relaxivity

    Science.gov (United States)

    Shu, Chunying; Corwin, Frank D.; Zhang, Jianfei; Chen, Zhijian; Reid, Jonathan E.; Sun, Minghao; Xu, Wei; Sim, Jae Hyun; Wang, Chunru; Fatouros, Panos P.; Esker, Alan R.; Gibson, Harry W.; Dorn, Harry C.

    2009-01-01

    A new magnetic resonance imaging (MRI) contrast agent based on the trimetallic nitride templated (TNT) metallofullerene, Gd3N@C80, was synthesized by a facile method in high yield. The observed longitudinal and transverse relaxivities, r1 and r2, for water hydrogens in the presence of the water-soluble gadofullerene 2, Gd3N@C80(OH)~26(CH2CH2COOM)~16 (M = Na or H), are 207 and 282 mM-1s-1 (per C80 cage) at 2.4 T, respectively; these values are 50 times larger than those of Gd3+ poly(aminocarboxylate) complexes, such as commercial Omniscan® and Magnevist®. This high 1H relaxivity for this new hydroxylated and carboxylated gadofullerene derivative provides high signal enhancement at significantly lower Gd concentration as demonstrated by in vitro and in vivo MRI studies. Dynamic light scattering data reveal a unimodal size distribution with an average hydrodynamic radius of ca. 78 nm in pure water (pH = 7), which is significantly different from other hydroxylated or carboxylated fullerene and metallofullerene derivatives reported to date. Agarose gel infusion results indicate that the gadofullerene 2 displayed diffusion properties different from that of commercial Omniscan® and those of PEG5000 modified Gd3N@C80. The reactive carboxyl functionality present on this highly efficient contrast agent may also serve as a precursor for biomarker tissue-targeting purposes. PMID:19445504

  5. AN INTERMOLECULAR 13C{1H} NUCLEAR OVERHAUSER EFFECT FOR THE CARBON OF CCl4 IN POLYMER SOLUTIONS

    Institute of Scientific and Technical Information of China (English)

    YAN Xin; WANG Dehua; QIAN Baogong

    1991-01-01

    An intermolecular 13C{1H} NOE of CCl4 in the solutions of polystyrene and polybutadiene and their copolymers was observed. The results show that the defined polymer-CCl4 interaction variable has a linear relation with the polymer composition and the difference of solubility parameters and exponentially depends on the reciprocal of temperature.

  6. 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

    Energy Technology Data Exchange (ETDEWEB)

    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

  7. Progress in nuclear magnetic resonance spectroscopy

    CERN Document Server

    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

  8. Near-zero-field nuclear magnetic resonance

    OpenAIRE

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

    2011-01-01

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

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

    Science.gov (United States)

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

    1999-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Nuclear Magnetic Resonance Technology for Medical Studies.

    Science.gov (United States)

    Budinger, Thomas F.; Lauterbur, Paul C.

    1984-01-01

    Reports on the status of nuclear magnetic resonance (NMR) from theoretical and clinical perspectives, reviewing NMR theory and relaxation parameters relevant to NMR imaging. Also reviews literature related to modern imaging strategies, signal-to-noise ratio, contrast agents, in vivo spectroscopy, spectroscopic imaging, clinical applications, and…

  12. magnetic order studied by nuclear methods

    CERN Document Server

    Reichl, C

    2001-01-01

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

  13. Diagnosis of breast tumors with 1H-MRS and dynamic contrast-enhanced magnetic resonance imaging%联合应用1H-MRS与MR动态增强成像诊断乳腺肿瘤

    Institute of Scientific and Technical Information of China (English)

    周欣; 张婷婷; 胡国清

    2012-01-01

    Objective To compare the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) alone and combined with 1 H-MRS in diagnosis of breast tumors. Methods ' H-MRS and DCE-MRI of 50 patients with breast tumors including 33 malignant lesions and 17 benign lesions were retrospectively analyzed. The diagnostic results of ' H-MRS and DCE-MRI were compared with pathological and clinical follow-up results. All patients underwent pre-enhanced conventional scanning, 1 H-MRS scanning and DCE-MR scanning after injection of contrast agent. The type of time-intensity curves (TIC) and display of choline (Cho) peak for all lesions were calculated. Results The diagnostic sensitivity, specificity and accuracy rate for TIC alone was 100% (33/33), 58. 82% (10/17) and 66. 00% (33/50), respectively, while was 100% (33/33), 88.24% (15/17) and 96.00% (48/50) respectively for combined application of 1H-MRS and DCE-MRI. There was statistical difference in diagnostic specificity and accuracy rate between the two methods (both P<0. 02). Conclusion DCE-MRI has lower specificity and accuracy rate for diagnosis of breast tumors. Combination of ' H-MRS and DCE-MRI can improve the diagnostic accuracy rate of breast tumors.%目的 比较应用MR动态增强成像(DCE-MRI)与联合应用1H-MRS及DCE-MRI对乳腺肿瘤的诊断价值.方法 回顾性分析50例乳腺肿瘤患者的1H-MRS及DCE-MRI表现,包括恶性肿瘤33例,良性肿瘤17例,并与病理及临床随诊结果进行对比.对所有患者分别行常规扫描、1H-MRS扫描及注射对比剂后动态增强扫描,分析时间-信号曲线(TIC)类型和胆碱(Cho)峰的显示情况.结果 以TIC类型判断肿瘤的良恶性,诊断的敏感度为100%(33/33),特异度为58.82%(10/17),准确率为66.00%(33/50);应用1H-MRS联合DCE-MRI诊断的敏感度为100%(33/33),特异度为88.24%(15/17),准确率为96.00%(48/50),与单纯DCE-MRI诊断的特异度和准确率差异有统计学意义(P均<0.02).结论 DCE

  14. 1H-NMR and photochemically-induced dynamic nuclear polarization studies on bovine pancreatic phospholipase A2

    NARCIS (Netherlands)

    Egmond, M.R.; Slotboom, A.J.; Haas, G.H. de; Dijkstra, Klaas; Kaptein, R.

    1980-01-01

    Proton-NMR resonances of trytophan 3 and tyrosine 69 in bovine pancreatic phospholipase A2, its pro-enzyme and in Ala1-transaminated protein were assigned using photochemically-induced dynamic nuclear polarization (photo-CIDNP) as such or in combination with spin-echo measurements. In addition assig

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. 1H-NMR and photochemically-induced dynamic nuclear polarization studies on bovine pancreatic phospholipase A2.

    Science.gov (United States)

    Egmond, M R; Slotboom, A J; De Haas, G H; Dijkstra, K; Kaptein, R

    1980-06-26

    Proton-NMR resonances of trytophan 3 and tyrosine 69 in bovine pancreatic phospholipase A2, its pro-enzyme and in Ala1-transaminated protein were assigned using photochemically-induced dynamic nuclear polarization (photo-CIDNP) as such or in combination with spin-echo measurements. In addition assignments were made by suppression of cross-relaxation effects using short (0.1 s) high-power laser pulses.

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

    Science.gov (United States)

    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.

  18. Using microcontact printing to fabricate microcoils on capillaries for high resolution proton nuclear magnetic resonance on nanoliter volumes

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.A.; Jackman, R.J.; Whitesides, G.M. [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States); Olson, D.L.; Sweedler, J.V. [Beckman Institute and Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    1997-05-01

    This letter describes a method for producing conducting microcoils for high resolution proton nuclear magnetic resonance ({sup 1}H-NMR) spectroscopy on nanoliter volumes. This technique uses microcontact printing and electroplating to form coils on microcapillaries. Nuclear magnetic resonance spectra collected using these microcoils, have linewidths less than 1 Hz for model compounds and a limit of detection (signal-to-noise ratio=3) for ethylbenzene of 2.6 nmol in 13 min. {copyright} {ital 1997 American Institute of Physics.}

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-02-26

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

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

    Science.gov (United States)

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

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

  1. Nuclear magnetic resonance spectroscopy of single subnanoliter ova

    CERN Document Server

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

    2015-01-01

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

  2. Nuclear magnetic resonance properties of lunar samples.

    Science.gov (United States)

    Kline, D.; Weeks, R. A.

    1972-01-01

    Nuclear magnetic resonance spectra of Na-23, Al-27, and P-31 in fines samples 10084,60 and 14163,168 and in crystalline rock samples 12021,55 and 14321,166, have been recorded over a range of frequencies up to 20 MHz. A shift in the field at which maximum absorption occurs for all of the spectra relative to the field at which maximum absorption occurs for terrestrial analogues is attributed to a sample-dependent magnetic field at the Na, Al, and P sites opposing the laboratory field. The magnitude of these fields internal to the samples is sample dependent and varies from 5 to 10 G. These fields do not correlate with the iron content of the samples. However, the presence of single-domain particles of iron distributed throughout the plagioclase fraction that contains the principal fraction of Na and Al is inferred from electron magnetic resonance spectra shapes.

  3. 轻度认知功能损害患者1H-MRS的研究%The study of brain proton magnetic resonance spectroscopy(1H-MRS) in patients with mild cognitive impairment

    Institute of Scientific and Technical Information of China (English)

    张立苹; 蒋根娣; 苗迎春; 谭中建

    2011-01-01

    目的:探讨氢质子磁共振波谱(1H-MRS)对遗忘型轻度认知功能损害(aMCI)患者,Alzheimer病(AD)和正常对照组的诊断和鉴别诊断的作用.方法:采用德国Siemens公司生产的Novus 1.5T磁共振成像系统,对入选的研究对象行相应的常规MRI扫描.脑内感兴趣区的1H-MRS采集,采用SVS-SE-30序列,对12例aMCI患者、12例AD患者和12例性别、年龄、文化程度相匹配健康对照的双侧内侧颞叶和左后扣带回1H-MRS进行分析,比较各组间N-L酰天门冬氨酸(NAA)/肌酸(Cr),胆碱(Cho)/Cr,肌醇(mI)/Cr,NAA/mI及不对称指数的差别.结果:左内侧颢叶aMCI和AD组的NAA/Cr均明显低于NC组(P0.05);aMCI组和AD组的NAA/mI低于NC组(P0.05).右内侧颞叶AD组和aMCI的NAA/mI显著低于NC组(P0.05).结论:左内侧颞叶NAMCr的变化在aMCI、AD与NC鉴别诊断中有重要价值:双内侧颞叶NAA/mI比值的变化早于NAA/Cr的改变,可能神经胶质的增生早于神经元的丢失.1H-MRS是aMCI、AD与NC的诊断、鉴别诊断和监测的有用工具.%Objective: To evaluate the roles of proton magnetic resonance spectroscopy(1H-MRS) in the diagnosis and differential diagnosis of amnestic mild cognitive impairment (aMCI), Alzheimer disease (AD) and normal control group. Methods: Normal scanning, 1H-MRS of VOI are acquired by Siemens Novus 1.5T MRI system. A 1H-MRS was performed in the bilateral medial temporal lobes (MITS) and left posterior cingulated contex (PCC) of the 12 aMCI patients, 12 AD patients and 12 healthy age and sex-matched controls using single voxel sequence mode (SVS-SE-30). The ratios of NAA/Ct, Cho/Cr, mI/Cr, NAA/mI and metabolite asymmetries were compared among the groups. Results: NAA/Cr of left medial temporal lobe in the aMCI and AD groups were lower than that of the NC group with statistical significance (P<0.05), AD group and the aMCI group had no statistically significant difference(P>0.05); NAA/mI in aMCI and AD group was lower than that in the NC

  4. 1H magnetic resonance spectroscopy and diffusion weighted imaging findings of medulloblastoma in 3.0T MRI A retrospective analysis of 17 cases

    Institute of Scientific and Technical Information of China (English)

    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.

  5. Near-zero-field nuclear magnetic resonance

    CERN Document Server

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

    2011-01-01

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

  6. Near-zero-field nuclear magnetic resonance.

    Science.gov (United States)

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

    2011-09-02

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

  7. Thermal Transition of Ribonuclease A Observed Using Proton Nuclear Magnetic Resonance

    Institute of Scientific and Technical Information of China (English)

    闫永彬; 罗雪春; 周海梦; 张日清

    2001-01-01

    The thermal transition of bovine pancreatic ribonuclease A (RNase A) was investigated using proton nuclear magnetic resonance (NMR). Significant resonance overlap in the large native protein limits accurate assignments in the 1H NMR spectrum. This study proposes extending the investigation of large proteins by dynamic analysis. Comparison of the traditional method and the correlation coefficient method suggests successful application of spectrum image analysis in dynamic protein studies by NMR.

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

    Institute of Scientific and Technical Information of China (English)

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

    2001-01-01

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

  9. Experiments in Nuclear Magnetic Resonance Microscopy

    Science.gov (United States)

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

    2006-03-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1991-12-31

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

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

    Science.gov (United States)

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

    2017-03-13

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

  12. Spatial localization in nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-08-21

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

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

    Science.gov (United States)

    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. Facile Preparation of a New Gadofullerene-Based Magnetic Resonance Imaging Contrast Agent with High 1H Relaxivity

    OpenAIRE

    Shu, Chunying; Corwin, Frank D.; Zhang, Jianfei; Chen, Zhijian; Reid, Jonathan E.; Sun, Minghao; Xu, Wei; Sim, Jae Hyun; Wang, Chunru; Fatouros, Panos P.; Alan R Esker; Gibson, Harry W.; Dorn, Harry C.

    2009-01-01

    A new magnetic resonance imaging (MRI) contrast agent based on the trimetallic nitride templated (TNT) metallofullerene, Gd3N@C80, was synthesized by a facile method in high yield. The observed longitudinal and transverse relaxivities, r1 and r2, for water hydrogens in the presence of the water-soluble gadofullerene 2, Gd3N@C80(OH)~26(CH2CH2COOM)~16 (M = Na or H), are 207 and 282 mM-1s-1 (per C80 cage) at 2.4 T, respectively; these values are 50 times larger than those of Gd3+ poly(aminocarbo...

  15. Quantum information processing and nuclear magnetic resonance

    CERN Document Server

    Cummins, H K

    2001-01-01

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

  16. Nuclear magnetic resonance imaging of the spine

    Energy Technology Data Exchange (ETDEWEB)

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

    1984-01-01

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

  17. In vivo proton magnetic resonance spectroscopy (1H-MRS) evaluation of the metabolite concentration of optic radiation in primary open angle glaucoma

    Energy Technology Data Exchange (ETDEWEB)

    Sidek, Sabrilhakim [University of Malaya, Department of Biomedical Imaging, University Malaya Research Imaging Centre (UMRIC), Kuala Lumpur (Malaysia); Universiti Teknologi MARA, Medical Imaging Unit, Faculty of Medicine, Sg Buloh, Selangor (Malaysia); Ramli, Norlisah; Rahmat, Kartini; Kuo, Tan Li [University of Malaya, Department of Biomedical Imaging, University Malaya Research Imaging Centre (UMRIC), Kuala Lumpur (Malaysia); Ramli, Norlina Mohd; Abdulrahman, Fadzlina [University of Malaya, Department of Ophthalmology, Faculty of Medicine, Kuala Lumpur (Malaysia)

    2016-12-15

    To compare the metabolite concentration of optic radiation in glaucoma patients with that of healthy subjects using Proton Magnetic Resonance Spectroscopy (1H-MRS). 1H-MRS utilising the Single-Voxel Spectroscopy (SVS) technique was performed using a 3.0Tesla MRI on 45 optic radiations (15 from healthy subjects, 15 from mild glaucoma patients, and 15 from severe glaucoma patients). A standardised Volume of Interest (VOI) of 20 x 20 x 20 mm was placed in the region of optic radiation. Mild and severe glaucoma patients were categorised based on the Hodapp-Parrish-Anderson (HPA) classification. Mean and multiple group comparisons for metabolite concentration and metabolite concentration ratio between glaucoma grades and healthy subjects were obtained using one-way ANOVA. The metabolite concentration and metabolite concentration ratio between the optic radiations of glaucoma patients and healthy subjects did not demonstrate any significant difference (p > 0.05). Our findings show no significant alteration of metabolite concentration associated with neurodegeneration that could be measured by single-voxel 1H-MRS in optic radiation among glaucoma patients. (orig.)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  20. Structural and Quantitative Analysis of Three C-Glycosylflavones by Variable Temperature Proton Quantitative Nuclear Magnetic Resonance

    Directory of Open Access Journals (Sweden)

    Jing Liu

    2017-01-01

    Full Text Available Quantitative nuclear magnetic resonance is a powerful tool in drug analysis because of its speed, precision, and efficiency. In present study, the application of variable temperature proton quantitative nuclear magnetic resonance (VT-1H-qNMR for the calibration of three C-glycosylflavones including orientin, isoorientin, and schaftoside as reference substances was reported. Since there was conformational equilibrium due to the restricted rotation around the C(sp3-C(sp2 bond in C-glycosylflavones, the conformational behaviors were investigated by VT-NMR and verified by molecular mechanics (MM calculation. The VT-1H-qNMR method was validated including the linearity, limit of quantification, precision, and stability. The results were consistent with those obtained from mass balance approach. VT-1H-qNMR can be deployed as an effective tool in analyzing C-glycosylflavones.

  1. Structural and Quantitative Analysis of Three C-Glycosylflavones by Variable Temperature Proton Quantitative Nuclear Magnetic Resonance

    Science.gov (United States)

    Liu, Yang; Dai, Zhong

    2017-01-01

    Quantitative nuclear magnetic resonance is a powerful tool in drug analysis because of its speed, precision, and efficiency. In present study, the application of variable temperature proton quantitative nuclear magnetic resonance (VT-1H-qNMR) for the calibration of three C-glycosylflavones including orientin, isoorientin, and schaftoside as reference substances was reported. Since there was conformational equilibrium due to the restricted rotation around the C(sp3)-C(sp2) bond in C-glycosylflavones, the conformational behaviors were investigated by VT-NMR and verified by molecular mechanics (MM) calculation. The VT-1H-qNMR method was validated including the linearity, limit of quantification, precision, and stability. The results were consistent with those obtained from mass balance approach. VT-1H-qNMR can be deployed as an effective tool in analyzing C-glycosylflavones. PMID:28243484

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

    CERN Document Server

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

    2012-01-01

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

  3. Dynamic nuclear polarization in a magnetic resonance force microscope experiment.

    Science.gov (United States)

    Issac, Corinne E; Gleave, Christine M; Nasr, Paméla T; Nguyen, Hoang L; Curley, Elizabeth A; Yoder, Jonilyn L; Moore, Eric W; Chen, Lei; Marohn, John A

    2016-04-01

    We report achieving enhanced nuclear magnetization in a magnetic resonance force microscope experiment at 0.6 tesla and 4.2 kelvin using the dynamic nuclear polarization (DNP) effect. In our experiments a microwire coplanar waveguide delivered radiowaves to excite nuclear spins and microwaves to excite electron spins in a 250 nm thick nitroxide-doped polystyrene sample. Both electron and proton spin resonance were observed as a change in the mechanical resonance frequency of a nearby cantilever having a micron-scale nickel tip. NMR signal, not observable from Curie-law magnetization at 0.6 T, became observable when microwave irradiation was applied to saturate the electron spins. The resulting NMR signal's size, buildup time, dependence on microwave power, and dependence on irradiation frequency was consistent with a transfer of magnetization from electron spins to nuclear spins. Due to the presence of an inhomogeneous magnetic field introduced by the cantilever's magnetic tip, the electron spins in the sample were saturated in a microwave-resonant slice 10's of nm thick. The spatial distribution of the nuclear polarization enhancement factor ε was mapped by varying the frequency of the applied radiowaves. The observed enhancement factor was zero for spins in the center of the resonant slice, was ε = +10 to +20 for spins proximal to the magnet, and was ε = -10 to -20 for spins distal to the magnet. We show that this bipolar nuclear magnetization profile is consistent with cross-effect DNP in a ∼10(5) T m(-1) magnetic field gradient. Potential challenges associated with generating and using DNP-enhanced nuclear magnetization in a nanometer-resolution magnetic resonance imaging experiment are elucidated and discussed.

  4. Nuclear magnetic shielding constants of liquid water: insights from hybrid quantum mechanics/molecular mechanics models.

    Science.gov (United States)

    Kongsted, Jacob; Nielsen, Christian B; Mikkelsen, Kurt V; Christiansen, Ove; Ruud, Kenneth

    2007-01-21

    We present a gauge-origin independent method for the calculation of nuclear magnetic shielding tensors of molecules in a structured and polarizable environment. The method is based on a combination of density functional theory (DFT) or Hartree-Fock wave functions with molecular mechanics. The method is unique in the sense that it includes three important properties that need to be fulfilled in accurate calculations of nuclear magnetic shielding constants: (i) the model includes electron correlation effects, (ii) the model uses gauge-including atomic orbitals to give gauge-origin independent results, and (iii) the effect of the environment is treated self-consistently using a discrete reaction-field methodology. The authors present sample calculations of the isotropic nuclear magnetic shielding constants of liquid water based on a large number of solute-solvent configurations derived from molecular dynamics simulations employing potentials which treat solvent polarization either explicitly or implicitly. For both the (17)O and (1)H isotropic shielding constants the best predicted results compare fairly well with the experimental data, i.e., they reproduce the experimental solvent shifts to within 4 ppm for the (17)O shielding and 1 ppm for the (1)H shielding.

  5. Neutron Diffraction Studies of Nuclear Magnetic Ordering in Copper

    DEFF Research Database (Denmark)

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

    1989-01-01

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

  6. Nuclear Composition of Magnetized GRB Jets

    CERN Document Server

    Shibata, Sanshiro

    2015-01-01

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

  7. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  8. 1H-MRS在遗传性脑白质营养不良中的研究进展%Application of 1H-magnetic resonance spectroscopy in inherited leukodystrophies

    Institute of Scientific and Technical Information of China (English)

    程爱兰; 金彪

    2015-01-01

    Inherited leukodystrophies are a heterogeneous group of diseases caused by enzyme or gene deficiencies, resulting in abnormal formation, turnover or destruction of myelin. As lack of clinical and imaging specificities, diagnosis of leukodystrophies is still a challenge. MRS is the only noninvasive tool to detect metabolites in vivo which can be used in the diagnosis and prognosis of leukodystrophies. Here we reviewed the application of 1H-MRS used in different inherited leukodystrophies.%遗传性脑白质营养不良是一组由于相关酶和基因缺乏导致的髓鞘形成障碍、延迟及破坏的疾病总称。其临床及影像表现缺乏特异性,因此诊断该组疾病对医生仍然是一个挑战。1H-MRS是目前检测活体生物代谢唯一的无创性手段,可以定量检测脑代谢物,进而辅助诊断及鉴别不同类型的遗传性脑白质营养不良。就1H-MRS在遗传性脑白质营养不良中的应用作一综述。

  9. Nuclear magnetic resonance data of C9H11ITe

    Science.gov (United States)

    Mikhova, B. M.

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

  10. Nuclear magnetic resonance data of C10H13ITe

    Science.gov (United States)

    Mikhova, B. M.

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2000-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Toru Tomimatsu

    2015-08-01

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

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

    Science.gov (United States)

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

    2010-12-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-02-01

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

  16. Pulse Design in Solid-State Nuclear Magnetic Resonance

    DEFF Research Database (Denmark)

    Palani, Ravi Shankar

    2017-01-01

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

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

    NARCIS (Netherlands)

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

    1998-01-01

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

  18. Superconducting quantum interference device microsusceptometer balanced over a wide bandwidth for nuclear magnetic resonance applications

    Energy Technology Data Exchange (ETDEWEB)

    Vinante, A., E-mail: anvinante@fbk.eu; Falferi, P. [Istituto di Fotonica e Nanotecnologie, CNR - Fondazione Bruno Kessler, I-38123 Povo, Trento (Italy); Mezzena, R. [Dipartimento di Fisica, Università di Trento, I-38123 Povo, Trento (Italy)

    2014-10-15

    Superconducting Quantum Interference Device (SQUID) microsusceptometers have been widely used to study magnetic properties of materials at microscale. As intrinsically balanced devices, they could also be exploited for direct SQUID-detection of nuclear magnetic resonance (NMR) from micron sized samples, or for SQUID readout of mechanically detected NMR from submicron sized samples. Here, we demonstrate a double balancing technique that enables achievement of very low residual imbalance of a SQUID microsusceptometer over a wide bandwidth. In particular, we can generate ac magnetic fields within the SQUID loop as large as 1 mT, for frequencies ranging from dc up to a few MHz. As an application, we demonstrate direct detection of NMR from {sup 1}H spins in a glycerol droplet placed directly on top of the 20 μm SQUID loops.

  19. Electron transport through nuclear pasta in magnetized neutron stars

    CERN Document Server

    Yakovlev, D G

    2015-01-01

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

  20. Parahydrogen enhanced zero-field nuclear magnetic resonance

    OpenAIRE

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

    2011-01-01

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

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

    Science.gov (United States)

    King, Roy W.; Williams, Kathryn R.

    1989-01-01

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

  2. Prefrontal grey and white matter neurometabolite changes after atomoxetine and methylphenidate in children with attention deficit/hyperactivity disorder: a (1)H magnetic resonance spectroscopy study.

    Science.gov (United States)

    Husarova, Veronika; Bittsansky, Michal; Ondrejka, Igor; Dobrota, Dusan

    2014-04-30

    Attention deficit/hyperactivity disorder (ADHD) is the most common neurobehavioral childhood disorder. Dysfunction of prefrontal neural circuits which are responsible for executive and attentional functions has been previously shown in ADHD. We investigated the neurometablite changes in areas included in dorsolateral prefrontal neural circuits after 2 months of long-acting methylphenidate or atomoxetine medication in children with ADHD who were responders to treatment. Twenty-one ADHD children were examined by single voxel (1)H-magnetic resonance spectroscopy (MRS) before and after 2 months of medication with OROS methylphenidate (n=10) or atomoxetine (n=11). The spectra were taken from the dorsolateral prefrontal cortex (DLPFC, 8ml) and white matter behind the DLPFC (anterior semioval center, 7.5ml), bilaterally. NAA and NAA/Cr (N-acetylaspartate/creatine) decreased in the left DLPFC and Cho/Cr (choline/creatine) increased in the right DLPFC after atomoxetine medication. Glu+Gln and Glu+Gln/Cr (glutamate/glutamine) increased in the left white matter after methylphenidate medication. We hypothesize that atomoxetine could decrease hyperactivation of DLPFC neurons and methylphenidate could lead to increased activation of cortical glutamatergic projections with the consequences of increased tonic dopamine release in the mesocortical system.

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

    Science.gov (United States)

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

    2011-03-01

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

  4. Magnet Design Considerations for Fusion Nuclear Science Facility

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-01

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

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

    Science.gov (United States)

    Lens, P N; Hemminga, M A

    1998-01-01

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

  6. Evaluation of nuclear magnetic resonance spectroscopy variability

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  8. High Radiation Environment Nuclear Fragment Separator Magnet

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-31

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

  9. In vivo nuclear magnetic resonance imaging

    Science.gov (United States)

    Leblanc, A.

    1986-01-01

    During the past year the Woodlands Baylor Magnetic Resonance Imaging (MRI) facility became fully operational. A detailed description of this facility is given. One significant instrument addition this year was the 100 MHz, 40cm bore superconducting imaging spectrometer. This instrument gives researchers the capability to acquire high energy phosphate spectra. This will be used to investigate ATP, phosphocreatinine and inorganic phosphate changes in normal and atrophied muscle before, during and after exercise. An exercise device for use within the bore of the imaging magnet is under design/construction. The results of a study of T sub 1 and T sub 2 changes in atrophied muscle in animals and human subjects are given. The imaging and analysis of the lower leg of 15 research subjects before and after 5 weeks of complete bedrest was completed. A compilation of these results are attached.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-04-01

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

  11. Zero-Field Nuclear Magnetic Resonance

    OpenAIRE

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

    1983-01-01

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

  12. Zero-field nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

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

    1983-05-30

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

  14. Neutron studies of nuclear magnetism at ultralow temperature

    DEFF Research Database (Denmark)

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

    1998-01-01

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

  15. C-13 nuclear magnetic resonance in organic geochemistry.

    Science.gov (United States)

    Balogh, B.; Wilson, D. M.; Burlingame, A. L.

    1972-01-01

    Study of C-13 nuclear magnetic resonance (NMR) spectra of polycyclic fused systems. The fingerprint qualities of the natural abundance in C-13 NMR spectra permitting unequivocal identification of these compounds is discussed. The principle of structural additivity of C-13 NMR information is exemplified on alpha and beta androstanes, alpha and beta cholestanes, ergostanes, sitostanes, and isodecanes.

  16. Nuclear Magnetic Resonance Coupling Constants and Electronic Structure in Molecules.

    Science.gov (United States)

    Venanzi, Thomas J.

    1982-01-01

    Theory of nuclear magnetic resonance spin-spin coupling constants and nature of the three types of coupling mechanisms contributing to the overall spin-spin coupling constant are reviewed, including carbon-carbon coupling (neither containing a lone pair of electrons) and carbon-nitrogen coupling (one containing a lone pair of electrons).…

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

    Science.gov (United States)

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

    2006-01-01

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

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

    NARCIS (Netherlands)

    Wit, de J.L.

    1978-01-01

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

  19. Nuclear magnetic resonance imaging of water motion in plants

    NARCIS (Netherlands)

    Scheenen, T.W.J.

    2001-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

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

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

    Science.gov (United States)

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

    2013-07-01

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

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

    Science.gov (United States)

    Kruk, D.; Meier, R.; Rachocki, A.; Korpała, A.; Singh, R. K.; Rössler, E. A.

    2014-06-01

    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.

  3. High-resolution proton nuclear magnetic resonance spectroscopy of ovarian cyst fluid.

    Science.gov (United States)

    Boss, E A; Moolenaar, S H; Massuger, L F; Boonstra, H; Engelke, U F; de Jong, J G; Wevers, R A

    2000-08-01

    Most ovarian tumors are cystic structures containing variable amounts of fluid. Several studies of ovarian cyst fluid focus on one specific metabolite using conventional assay systems. We examined the potential of (1)H-nuclear magnetic resonance spectroscopy in evaluation of the overall metabolic composition of cyst fluid from different ovarian tumors. Ovarian cyst fluid samples obtained from 40 patients with a primary ovarian tumor (12 malignant and 28 benign) were examined. After deproteinization and pD standardization, we performed (1)H-NMR spectroscopy on a 600 MHz instrument. With (1)H-NMR spectroscopy we found detectable concentrations of 36 metabolites with high intersample variation. A number of unassigned resonances as well as unexpected metabolites were found. We introduce an overall inventory of the low-molecular-weight metabolites in ovarian cyst fluid with corresponding resonances. Significant differences in concentration (p overview of low-molecular-weight proton-containing metabolities present in ovarian cyst fluid samples. The metabolic composition of cyst fluid differs significantly between benign and malignant ovarian tumors. Furthermore, differences between benign subgroups possibly related to histopathological behaviour can be detected. The presence of N-acetyl aspartic acid and 5-oxoproline exclusively in serous cystadenoma samples is remarkable. Future studies will concentrate on these findings and explore the possibilities of extrapolating information from the in vitro studies to in vivo practice, in which metabolic differences between malignant and benign subtypes can be of great importance in a pre-operative phase.

  4. Application of two-dimensional J-resolved nuclear magnetic resonance spectroscopy to differentiation of beer

    Energy Technology Data Exchange (ETDEWEB)

    Khatib, Alfi [Division of Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands); Wilson, Erica G. [Division of Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands); Kim, Hye Kyong [Division of Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands); Lefeber, Alfons W.M. [Division of NMR, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands); Erkelens, Cornelis [Division of NMR, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands); Choi, Young Hae [Division of Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands)]. E-mail: y.choi@chem.leidenuniv.nl; Verpoorte, Robert [Division of Pharmacognosy, Section Metabolomics, Institute of Biology, Leiden University, P.O. Box 9502, 2300 RA Leiden (Netherlands)

    2006-02-16

    A number of ingredients in beer that directly or indirectly affect its quality require an unbiased wide-spectrum analytical method that allows for the determination of a wide array of compounds for its efficient control. {sup 1}H nuclear magnetic resonance (NMR) spectroscopy is a method that clearly meets this description as the broad range of compounds in beer is detectable. However, the resulting congestion of signals added to the low resolution of {sup 1}H NMR spectra makes the identification of individual components very difficult. Among two-dimensional (2D) NMR techniques that increase the resolution, J-resolved NMR spectra were successfully applied to the analysis of 2-butanol extracts of beer as overlapping signals in {sup 1}H NMR spectra were fully resolved by the additional axis of the coupling constant. Principal component analysis based on the projected J-resolved NMR spectra showed a clear separation between all of the six brands of pilsner beer evaluated in this study. The compounds responsible for the differentiation were identified by 2D NMR spectra including correlated spectroscopy and heteronuclear multiple bond correlation spectra together with J-resolved spectra. They were identified as nucleic acid derivatives (adenine, uridine and xanthine), amino acids (tyrosine and proline), organic acid (succinic and lactic acid), alcohol (tyrosol and isopropanol), cholines and carbohydrates.

  5. Effect of fertilizers on galanthamine and metabolite profiles in narcissus bulbs by 1H NMR

    NARCIS (Netherlands)

    Lubbe, A.; Choi, Y.H.; Vreeburg, P.J.M.; Verpoorte, R.

    2011-01-01

    Narcissus bulbs contain the biologically active alkaloid galanthamine, and Narcissus is being developed as a natural source of the molecule for the pharmaceutical industry. The effect of fertilizer on galanthamine production was investigated in a field study using a 1H nuclear magnetic resonance (NM

  6. Unconventional nuclear magnetic resonance techniques using nanostructured diamond surfaces

    Science.gov (United States)

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

    2014-03-01

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

  7. Monitoring tumor response of prostate cancer to radiation therapy by multi-parametric 1H and hyperpolarized 13C magnetic resonance imaging

    Science.gov (United States)

    Zhang, Vickie Yi

    Radiation therapy is one of the most common curative therapies for patients with localized prostate cancer, but despite excellent success rates, a significant number of patients suffer post- treatment cancer recurrence. The accurate characterization of early tumor response remains a major challenge for the clinical management of these patients. Multi-parametric MRI/1H MR spectroscopy imaging (MRSI) has been shown to increase the diagnostic performance in evaluating the effectiveness of radiation therapy. 1H MRSI can detect altered metabolic profiles in cancerous tissue. In this project, the concentrations of prostate metabolites from snap-frozen biopsies of recurrent cancer after failed radiation therapy were correlated with histopathological findings to identify quantitative biomarkers that predict for residual aggressive versus indolent cancer. The total choline to creatine ratio was significantly higher in recurrent aggressive versus indolent cancer, suggesting that use of a higher threshold tCho/Cr ratio in future in vivo 1H MRSI studies could improve the selection and therapeutic planning for patients after failed radiation therapy. Varying radiation doses may cause a diverse effect on prostate cancer micro-environment and metabolism, which could hold the key to improving treatment protocols for individual patients. The recent development and clinical translation of hyperpolarized 13C MRI have provided the ability to monitor both changes in the tumor micro-environment and its metabolism using a multi-probe approach, [1-13C]pyruvate and 13C urea, combined with 1H Multi-parametric MRI. In this thesis, hyperpolarized 13C MRI, 1H dynamic contrast enhancement, and diffusion weighted imaging were used to identify early radiation dose response in a transgenic prostate cancer model. Hyperpolarized pyruvate to lactate metabolism significantly decreased in a dose dependent fashion by 1 day after radiation therapy, prior to any changes observed using 1H DCE and diffusion

  8. Monte Carlo Simulation of Adiabatic Cooling and Nuclear Magnetism

    DEFF Research Database (Denmark)

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

    1988-01-01

    in experimental studies of nuclear magnetism using adiabatic demagnetization methods. It is found that, although fluctuations reduce the transition temperatures by 40%, the isentropes are reduced by less than 10% relative to those calculated by mean-field theory. The dynamics of the ordering process following...... constant-temperature or constant-magnetic-field quenches into the antiferromagnetic phase is found at late times to obey the classical Allen-Cahn growth law. The qualitative features of isentropic quenches and the nonequilibrium ordering phenomena during controlled heating treatments at constant rate...

  9. Lower "N"-Acetyl-Aspartate Levels in Prefrontal Cortices in Pediatric Bipolar Disorder: A (Superscript 1]H Magnetic Resonance Spectroscopy Study

    Science.gov (United States)

    Caetano, Sheila C.; Olvera, Rene L.; Hatch, John P.; Sanches, Marsal; Chen, Hua Hsuan; Nicoletti, Mark; Stanley, Jeffrey A.; Fonseca, Manoela; Hunter, Kristina; Lafer, Beny; Pliszka, Steven R.; Soares, Jair C.

    2011-01-01

    Objective: The few studies applying single-voxel [superscript 1]H spectroscopy in children and adolescents with bipolar disorder (BD) have reported low "N"-acetyl-aspartate (NAA) levels in the dorsolateral prefrontal cortex (DLPFC), and high myo-inositol/phosphocreatine plus creatine (PCr+Cr) ratios in the anterior cingulate. The aim of this study…

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-11-01

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

  11. Advances in Zero-Field Nuclear Magnetic Resonance Spectroscopy

    OpenAIRE

    Theis, Thomas

    2012-01-01

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

  12. Demonstration of Quantum Entanglement Control Using Nuclear Magnetic Resonance

    Institute of Scientific and Technical Information of China (English)

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

    2004-01-01

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

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

    OpenAIRE

    Hossein Pourmodheji; Ebrahim Ghafar-Zadeh; Sebastian Magierowski

    2016-01-01

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

  14. Nuclear magnetic resonance spectroscopy and chemometrics to identify pine nuts that cause taste disturbance.

    Science.gov (United States)

    Kobler, Helmut; Monakhova, Yulia B; Kuballa, Thomas; Tschiersch, Christopher; Vancutsem, Jeroen; Thielert, Gerhard; Mohring, Arne; Lachenmeier, Dirk W

    2011-07-13

    Nontargeted 400 MHz (13)C and (1)H nuclear magnetic resonance (NMR) spectroscopy was used in the context of food surveillance to reveal Pinus species whose nuts cause taste disturbance following their consumption, the so-called pine nut syndrome (PNS). Using principal component analysis, three groups of pine nuts were distinguished. PNS-causing products were found in only one of the groups, which however also included some normal products. Sensory analysis was still required to confirm PNS, but NMR allowed the sorting of 53% of 57 samples, which belong to the two groups not containing PNS species. Furthermore, soft independent modeling of class analogy was able to classify the samples between the three groups. NMR spectroscopy was judged as suitable for the screening of pine nuts for PNS. This process may be advantageous as a means of importation control that will allow the identification of samples suitable for direct clearance and those that require further sensory analysis.

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

    Science.gov (United States)

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

    2016-05-01

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

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

    Directory of Open Access Journals (Sweden)

    Mahmoud Rasly

    2016-05-01

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

  17. Chronic viral hepatitis C in pediatric age group; assessment of viral activity and hepatic fibrosis by 1H magnetic resonance spectroscopy and diffusion weighted imaging in asymptomatic

    Directory of Open Access Journals (Sweden)

    Shereen Mansour Galal

    2016-09-01

    Conclusion: Early diagnosis of asymptomatic chronic hepatitis C is essential to prevent or delay end stage chronic parenchymal liver disease. 1H MRS may be a potential noninvasive helpful diagnostic tool in the assessment of staging and fibrosis of asymptomatic chronic hepatitis C. The increase in metabolites were correlated with histopathological changes. DW-MRI can be considered as an effective predictor in the assessment of activity in chronic hepatitis C.

  18. Quantitative velocity distributions via nuclear magnetic resonance flow metering

    Science.gov (United States)

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

    2016-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Fan, N.Q.; Clarke, J.

    1993-10-19

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

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

    Science.gov (United States)

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

    2006-12-11

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

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

    Science.gov (United States)

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

    2015-12-01

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

  3. Proton Nuclear Magnetic Resonance-Spectroscopic Discrimination of Wines Reflects Genetic Homology of Several Different Grape (V. vinifera L.) Cultivars

    Science.gov (United States)

    Zhu, Yong; Wen, Wen; Zhang, Fengmin; Hardie, Jim W.

    2015-01-01

    Background and Aims Proton nuclear magnetic resonance spectroscopy coupled multivariate analysis (1H NMR-PCA/PLS-DA) is an important tool for the discrimination of wine products. Although 1H NMR has been shown to discriminate wines of different cultivars, a grape genetic component of the discrimination has been inferred only from discrimination of cultivars of undefined genetic homology and in the presence of many confounding environmental factors. We aimed to confirm the influence of grape genotypes in the absence of those factors. Methods and Results We applied 1H NMR-PCA/PLS-DA and hierarchical cluster analysis (HCA) to wines from five, variously genetically-related grapevine (V. vinifera) cultivars; all grown similarly on the same site and vinified similarly. We also compared the semi-quantitative profiles of the discriminant metabolites of each cultivar with previously reported chemical analyses. The cultivars were clearly distinguishable and there was a general correlation between their grouping and their genetic homology as revealed by recent genomic studies. Between cultivars, the relative amounts of several of the cultivar-related discriminant metabolites conformed closely with reported chemical analyses. Conclusions Differences in grape-derived metabolites associated with genetic differences alone are a major source of 1H NMR-based discrimination of wines and 1H NMR has the capacity to discriminate between very closely related cultivars. Significance of the Study The study confirms that genetic variation among grape cultivars alone can account for the discrimination of wine by 1H NMR-PCA/PLS and indicates that 1H NMR spectra of wine of single grape cultivars may in future be used in tandem with hierarchical cluster analysis to elucidate genetic lineages and metabolomic relations of grapevine cultivars. In the absence of genetic information, for example, where predecessor varieties are no longer extant, this may be a particularly useful approach. PMID

  4. Line broadening interference for high-resolution nuclear magnetic resonance spectra under inhomogeneous magnetic fields.

    Science.gov (United States)

    Wei, Zhiliang; Yang, Jian; Chen, Youhe; Lin, Yanqin; Chen, Zhong

    2015-04-01

    Nuclear magnetic resonance spectroscopy serves as an important tool for analyzing chemicals and biological metabolites. However, its performance is subject to the magnetic-field homogeneity. Under inhomogeneous fields, peaks are broadened to overlap each other, introducing difficulties for assignments. Here, we propose a method termed as line broadening interference (LBI) to provide high-resolution information under inhomogeneous magnetic fields by employing certain gradients in the indirect dimension to interfere the magnetic-field inhomogeneity. The conventional spectral-line broadening is thus interfered to be non-diagonal, avoiding the overlapping among adjacent resonances. Furthermore, an inhomogeneity correction algorithm is developed based on pattern recognition to recover the high-resolution information from LBI spectra. Theoretical deductions are performed to offer systematic and detailed analyses on the proposed method. Moreover, experiments are conducted to prove the feasibility of the proposed method for yielding high-resolution spectra in inhomogeneous magnetic fields.

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

    Science.gov (United States)

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

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

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

    Science.gov (United States)

    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.

  7. Quantitative produced water analysis using mobile 1H NMR

    Science.gov (United States)

    Wagner, Lisabeth; Kalli, Chris; Fridjonsson, Einar O.; May, Eric F.; Stanwix, Paul L.; Graham, Brendan F.; Carroll, Matthew R. J.; Johns, Michael L.

    2016-10-01

    Measurement of oil contamination of produced water is required in the oil and gas industry to the (ppm) level prior to discharge in order to meet typical environmental legislative requirements. Here we present the use of compact, mobile 1H nuclear magnetic resonance (NMR) spectroscopy, in combination with solid phase extraction (SPE), to meet this metrology need. The NMR hardware employed featured a sufficiently homogeneous magnetic field, such that chemical shift differences could be used to unambiguously differentiate, and hence quantitatively detect, the required oil and solvent NMR signals. A solvent system consisting of 1% v/v chloroform in tetrachloroethylene was deployed, this provided a comparable 1H NMR signal intensity for the oil and the solvent (chloroform) and hence an internal reference 1H signal from the chloroform resulting in the measurement being effectively self-calibrating. The measurement process was applied to water contaminated with hexane or crude oil over the range 1-30 ppm. The results were validated against known solubility limits as well as infrared analysis and gas chromatography.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-11

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

  9. Implementation of Quantum Private Queries Using Nuclear Magnetic Resonance

    Institute of Scientific and Technical Information of China (English)

    WANG Chuan; HAO Liang; ZHAO Lian-Jie

    2011-01-01

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

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

    Science.gov (United States)

    Lacelle, S

    1984-01-01

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

  11. Applications of Nuclear Magnetic Resonance Sensors to Cultural Heritage

    Directory of Open Access Journals (Sweden)

    Noemi Proietti

    2014-04-01

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

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

    Science.gov (United States)

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

    2014-04-21

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

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

    Science.gov (United States)

    Arvanitaki, Asimina; Geraci, Andrew A

    2014-10-17

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

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

    CERN Document Server

    Maidana, Carlos O

    2014-01-01

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

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

    Science.gov (United States)

    Lenevich, Stepan; Distefano, Mark D

    2011-01-15

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

  16. 11B nuclear magnetic resonance in boron-doped diamond

    Directory of Open Access Journals (Sweden)

    Miwa Murakami, Tadashi Shimizu, Masataka Tansho and Yoshihiko Takano

    2008-01-01

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

  17. Development of Metallic Magnetic Calorimeters for Nuclear Safeguards Applications

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-03-11

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

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

    Science.gov (United States)

    Ilisca, Ernest; Ghiglieno, Filippo

    2016-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    Smith, Matthias; Muon g-2 Collaboration Collaboration

    2016-03-01

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

  1. Marrow adiposity assessed on transiliac crest biopsy samples correlates with noninvasive measurement of marrow adiposity by proton magnetic resonance spectroscopy (1H-MRS) at the spine but not the femur

    Science.gov (United States)

    Shen, W.; Dempster, D. W.; Zhou, H.; Recker, R. R.; Lappe, J. M.; Kepley, A.; Kamanda-Kosseh, M.; Bucovsky, M.; Stein, E. M.; Nickolas, T. L.; Shane, E.

    2016-01-01

    Summary Measurement of marrow fat (MF) is important to the study of bone fragility. We measured MF on iliac biopsies and by spine/hip magnetic resonance spectroscopy in the same subjects. Noninvasively assessed spine MF a nd histomorphometrically assessed MF correlated well. MF quantity and relationships with bone volume differed by measurement site. Introduction Excess marrow fat has been implicated in the pathogenesis of osteoporosis in several populations. In the bone marrow, adipocytes and osteoblasts share a common precursor and are reciprocally regulated. In addition, adipocytes may secrete toxic fatty acids and adipokines that adversely affect osteoblasts. Measurement of marrow fat is important to the study of mechanisms of bone fragility. Marrow fat can be quantified on bone biopsy samples by histomorphometry and noninvasively by proton magnetic resonance spectroscopy (1H-MRS). In this study, we evaluate relationships between marrow fat assessed using both methods in the same subjects for the first time. Methods Sixteen premenopausal women, nine with idiopathic osteoporosis and seven normal controls, had marrow fat measured at the iliac crest by bone biopsy and at the lumbar spine (L3) and proximal femur by 1H-MRS. Results At L3, fat fraction by 1H-MRS correlated directly and significantly with marrow fat variables on iliac crest biopsies (r=0.5–0.8). In contrast, there were no significant correlations between fat fraction at the femur and marrow fat on biopsies. Marrow fat quantity (%) was greater at the femur than at L3 and the iliac crest and correlated inversely with total hip and femoral neck BMD by DXA. Conclusions In summary, measurement of marrow fat in transiliac crest biopsies correlates with marrow fat at the spine but not the proximal femur by 1H-MRS. There were site-specific differences in marrow fat quantity and in the relationships between marrow fat and bone volume. PMID:25986383

  2. Nonaqueous magnetic nanoparticle suspensions with controlled particle size and nuclear magnetic resonance properties.

    Science.gov (United States)

    Meledandri, Carla J; Stolarczyk, Jacek K; Ghosh, Swapankumar; Brougham, Dermot F

    2008-12-16

    We report the preparation of monodisperse maghemite (gamma-Fe2O3) nanoparticle suspensions in heptane, by thermal decomposition of iron(III) acetylacetonate in the presence of oleic acid and oleylamine surfactants. By varying the surfactant/Fe precursor mole ratio during synthesis, control was exerted both over the nanocrystal core size, in the range from 3 to 6 nm, and over the magnetic properties of the resulting nanoparticle dispersions. We report field-cycling 1H NMR relaxation analysis of the superparamagnetic relaxation rate enhancement of nonaqueous suspensions for the first time. This approach permits measurement of the relaxivity and provides information on the saturation magnetization and magnetic anisotropy energy of the suspended particles. The saturation magnetization was found to be in the expected range for maghemite particles of this size. The anisotropy energy was found to increase significantly with decreasing particle size, which we attribute to increased shape anisotropy. This study can be used as a guide for the synthesis of maghemite nanoparticles with selected magnetic properties for a given application.

  3. Investigation of the neuroprotective effects of bee-venom acupuncture in a mouse model of Parkinson's disease by using immunohistochemistry and In-vivo 1H magnetic resonance spectroscopy at 9.4 T

    Science.gov (United States)

    Yoon, Moon-Hyun; Lee, Do-Wan; Kim, Hyun-Jin; Chung, Jin-Yeung; Doo, Ah-Reum; Park, Hi-Joon; Kim, Seung-Nam; Choe, Bo-Young

    2013-01-01

    Neuroprotective therapeutics slows down the degeneration process in animal models of Parkinson's disease (PD). The neuronal survival in PD animal models is often measured by using immunohistochemistry. However, dynamic changes in the pathology of the brain cannot be explored with this technique. Application of in-vivo 1H magnetic resonance spectroscopy (1H MRS) can cover this shortcoming, as these techniques are non-invasive and can be repeated over time in the same animal. Thus, the sensitivity of both techniques to measure changes in the PD pathology was explored in an experiment studying the neuroprotective effects of the vigilance enhancer bee-venom (BV) in a mouse model of PD. The mice were pre-treated with 0.02-ml BV administered to the acupuncture point GB34 (Yangneungcheon) once every 3 days for 2 weeks. Three groups were classified as control, MPTP-intoxicated PD model and BV-treated mice. Outer volume suppression combined with the ultra-short echo-time STEAM (TE = 2.2 ms, TM = 20 ms, TR = 5000 ms) was used for localized in-vivo 1H MRS. Based on the 1H MRS spectral analysis, substantial changes of the neurochemical profiles were evaluated in the three investigated groups. In particular, the glutamate complex (Glx)/creatine (Cr) ratio (7.72 ± 1.25) in the PD group was significantly increased compared to that in the control group (3.93 ± 2.21, P = 0.001). Compared to the baseline values, the Glx/Cr ratio of the BV-treated group was significantly decreased 2 weeks after MPTP intoxication (one-way ANOVA, p acupuncture in a mouse model of PD could be quantified by using immunohistochemistry and 1H MRS.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-04-15

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

  6. 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

    Science.gov (United States)

    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…

  7. "Solvent Effects" in 1H NMR Spectroscopy.

    Science.gov (United States)

    Cavaleiro, Jose A. S.

    1987-01-01

    Describes a simple undergraduate experiment in chemistry dealing with the "solvent effects" in nuclear magnetic resonance (NMR) spectroscopy. Stresses the importance of having students learn NMR spectroscopy as a tool in analytical chemistry. (TW)

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  9. Safety of implantable coronary stents during 1H-magnetic resonance imaging at 1.0 and 1.5 T.

    Science.gov (United States)

    Strohm, O; Kivelitz, D; Gross, W; Schulz-Menger, J; Liu, X; Hamm, B; Dietz, R; Friedrich, M G

    1999-01-01

    The safety of most available implantable intracoronary stents during magnetic resonance imaging (MRI) has not been sufficiently tested. Minor, but possibly clinically significant, increases in temperature have not been excluded. We measured temperature changes of 14 different stents clinically in use or currently tested for release on the world market. Stents were examined in 1.0- and 1.5-T MR scanners with multiple sequences used in routine cardiac and thoracic MRI examinations ("clinical worst case") and after implantation of the stents into the coronary arteries of excised pig hearts (1.5-T scanner only). We used a highly sensitive infrared camera with a thermal resolution of 10 mK and did not see significant heating of any stent during the examinations. We conclude that MRI is safe in patients with the currently available intracoronary stents.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-07

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

  11. Early increase in marker of neuronal integrity with antidepressant treatment of major depression: 1H-magnetic resonance spectroscopy of N-acetyl-aspartate.

    Science.gov (United States)

    Taylor, Matthew J; Godlewska, Beata R; Norbury, Ray; Selvaraj, Sudhakar; Near, Jamie; Cowen, Philip J

    2012-11-01

    Increasing interest surrounds potential neuroprotective or neurotrophic actions of antidepressants. While growing evidence points to important early clinical and neuropsychological effects of antidepressants, the time-course of any effect on neuronal integrity is unclear. This study used magnetic resonance spectroscopy to assess effects of short-term treatment with escitalopram on N-acetyl-aspartate (NAA), a marker of neuronal integrity. Thirty-nine participants with major depression were randomly assigned to receive either 10 mg escitalopram or placebo daily in a double-blind, parallel group design. On the seventh day of treatment, PRESS data were obtained from a 30×30×20 mm voxel placed in medial frontal cortex. Age and gender-matched healthy controls who received no treatment were also scanned. Levels of NAA were significantly higher in patients treated with escitalopram than in either placebo-treated patients (p<0.01) or healthy controls (p<0.01). Our findings are consistent with the proposition that antidepressant treatment in depressed patients can produce early changes in neuronal integrity.

  12. Nuclear Magnetic Resonance Study of Nanoscale Ionic Materials

    KAUST Repository

    Oommen, Joanna Mary

    2010-08-13

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

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

    Science.gov (United States)

    Terskikh, Victor; Kermode, Allison R

    2011-01-01

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

  14. Explosives Detection Using Magnetic and Nuclear Resonance Techniques

    CERN Document Server

    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...

  15. Nuclear magnetic resonance tomography of the cervical canal

    Energy Technology Data Exchange (ETDEWEB)

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

    1985-12-01

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

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

    CERN Document Server

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-01-01

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

  18. Single crystal nuclear magnetic resonance in spinning powders

    Science.gov (United States)

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

    2011-10-01

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

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

    Science.gov (United States)

    Fan, N. Q.; Clarke, John

    1991-06-01

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

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

    CERN Document Server

    Kanegae, Y

    2003-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-05-15

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

  2. 1H-Magnetic resonance spectroscopy study of stimulant medication effect on brain metabolites in French Canadian children with attention deficit hyperactivity disorder

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    Michael W Vogel

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-07

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

  5. Influence of Hemolysis on Analytic Results of Nuclear Magnetic Resonance-based Metabonomics

    Directory of Open Access Journals (Sweden)

    Qiao LIU

    2015-09-01

    Full Text Available 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 field. 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 influence the analytic results of metabonomics, so in practical operation, hemolytic samples should be excluded from the study.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    CERN Document Server

    Singh, Harpreet; Dahiya, Harleen

    2016-01-01

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

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

    Science.gov (United States)

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

    2010-02-26

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-02-24

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

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

    CERN Document Server

    Hammerath, Franziska

    2012-01-01

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

  11. 脑缺血后脑温变化的1氢磁共振波谱脑温测量观察%Evolution of brain temperature in ischemic tissues by 1H magnetic resonance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    孙志华; 陈英敏; 张敬; 郭宏; 张云亭

    2014-01-01

    目的 应用1氢磁共振波谱(1H MRS)脑温测量技术评价猴大脑中动脉闭塞再灌注模型不同缺血区的脑温变化.方法 制备MR兼容恒温控制系统,利用脑生理液体模修正温度-化学位移方程,检测正常猴脑脑温.制作猴大脑中动脉闭塞再灌注模型,行动脉闭塞期及再灌注后1、3、6、12、24 h MR DWI、PWI、T2 WI及1H MRS检查,计算不同缺血区的脑温.结果 修正后的温度-NAA化学位移方程为T=37+ 100(CSNAA-2.039).正常猴脑平均脑温37.16℃.动脉闭塞期,不同缺血区脑温均高于对侧半球(P<0.05),缺血半暗带(IP)脑温升高最明显.再灌注后核心坏死区脑温先迅速下降而后升高,IP和低灌注区脑温缓慢下降,逐渐恢复正常.结论 1H MRS可无创性测量脑温,可评估脑组织的缺血程度.%Objective To explore the application of temperature measurement technique by 1H magnetic resonance spectroscopy (MRS) in an ischemia monkey model.Methods A MRI-compatible thermostatic control system was developed.And the equation was corrected between brain temperature and the chemical shift of N-acetyl-L-aspartic acid (NAA) through in vitro experiment.The normal brain temperature of monkey brain was measured.And a monkey model of middle cerebral artery occlusion (MCAO) and reperfusion was established.MR diffusion weighted imaging (DWI),perfusion weighted imaging (PWI),T2 weighted imaging and 1H MRS were performed at artery occlusion stage,1h,3h,6h,12h and 24h post-recanalization.The brain temperatures of different ischemic regions were calculated by the modified brain temperature-chemical shift equation.Results The modified equation was as follows:T =37 + 100(CSNAA-2.039).The normal brain temperature was 37.16 ℃.The models were successfully established in 4 monkeys.During arterial occlusion stage,the brain temperature of different ischemic tissue was higher than the contralateral hemisphere (P < 0.05),including infarct core,ischemic penumbra (IP

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-21

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

  13. Measurements of the neutron electric to magnetic form factor ratio GEn/GMn via the ^2H(\\vec{e},e'\\vec{n})^1H reaction to Q^2 = 1.45 (GeV/c)^2

    CERN Document Server

    Plaster, B; Aghalaryan, A; Crouse, E; MacLachlan, G; Tajima, S; Tireman, W; Ahmidouch, A; Anderson, B D; Arenhövel, H; Asaturyan, R; Baker, O K; Baldwin, A R; Barkhuff, D; Breuer, H; Carlini, R; Christy, E; Churchwell, S; Cole, L; Danagulyan, S; Day, D; Eden, T; Elaasar, M; Ent, R; Farkhondeh, M; Fenker, H; Finn, J M; Gan, L; Gasparian, A; Garrow, K; Gueye, P; Howell, C R; Hu, B; Jones, M K; Kelly, J J; Keppel, C; Khandaker, M; Kim, W Y; Kowalski, S; Lung, A; Mack, D; Madey, R; Manley, D M; Markowitz, P; Mitchell, J; Mkrtchyan, H; Opper, A K; Perdrisat, C; Punjabi, V; Raue, B A; Reichelt, T; Reinhold, J; Roche, J; Sato, Y; Savvinov, N; Semenova, I A; Seo, W; Simicevic, N; Smith, G; Stepanyan, S; Tadevosyan, V; Tang, L; Taylor, S; Ulmer, P E; Vulcan, W; Watson, J W; Wells, S; Wesselmann, F; Wood, S; Yan, C; Yang, S; Yuan, L; Zhang, W M; Zhu, H; Zhu, X

    2003-01-01

    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(\\vec{e},e'\\vec{n})1H reaction, at three Q^2 values of 0.45, 1.13, and 1.45 (GeV/c)^2. The data at Q^2 = 1.13 and 1.45 (GeV/c)^2 are the first direct experimental measurements of GEn employing polarization degrees of freedom in the Q^2 > 1 (GeV/c)^2 region and stand as the most precise determinations of GEn for all values of Q^2.

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

    Science.gov (United States)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. Nuclear Magnetic Resonance (NMR) as a tool for the study of the metabolism of Rickettsia slovaca.

    Science.gov (United States)

    García-Álvarez, Lara; Busto, Jesús H; Peregrina, Jesús M; Santibáñez, Sonia; Portillo, Aránzazu; Avenoza, Alberto; Oteo, José A

    2015-01-01

    Rickettsial infections are caused by intracellular bacteria. They do not grow in standard culture media so there are limitations in routine practice to study their metabolism. Nuclear Magnetic Resonance (NMR) spectroscopy is used for identification of metabolites in biological samples. Vero cells infected with Rickettsia slovaca as well as uninfected cells were monitored by (1)H NMR showing the presence of ethanol and lactic acid. As no differences were observed, labeled compounds were added into cultures. When D-[1-13C]glucose was monitored by (13)C NMR no differences among infected and uninfected cells were observed in metabolic profiles. Glucose was transformed into ethanol in all cultures. Monitored experiments carried out with [2-13C]glycine showed differences between infected and uninfected cell cultures spectra. Glycine was partially transformed into serine, but the amount of the serine formed was larger in those infected. Moreover, L-[2-13C]leucine, L-[1-13C]isoleucine and L-[15N]tyrosine were evaluated. No differences among infected and uninfected cells were observed in the metabolic profiles when tyrosine and leucine were monitored. The amino acid L-[1-13C]isoleucine exhibited different metabolism in presence of the R. slovaca, showing a promising behavior as biomarker. In this work we focused on finding one or more compounds that could be metabolized specifically by R. slovaca and could be used as an indicator of its activity.

  17. Nuclear magnetic resonance metabonomic profiling using tO2PLS

    Energy Technology Data Exchange (ETDEWEB)

    Kirwan, Gemma M., E-mail: gemma.kirwan@gmail.com [Department of Chemistry, School of Applied Sciences, RMIT University, City Campus, Vic 3001 (Australia); Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho Uji, Kyoto (Japan); Hancock, Timothy [Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho Uji, Kyoto (Japan); Hassell, Kathryn [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Vic 3083 (Australia); Niere, Julie O. [Department of Chemistry, School of Applied Sciences, RMIT University, City Campus, Vic 3001 (Australia); Nugegoda, Dayanthi [Biotechnology and Environmental Biology, School of Applied Sciences, RMIT University, PO Box 71, Bundoora, Vic 3083 (Australia); Goto, Susumu [Bioinformatics Center, Institute for Chemical Research, Kyoto University, Gokasho Uji, Kyoto (Japan); Adams, Michael J. [Department of Chemistry, School of Applied Sciences, RMIT University, City Campus, Vic 3001 (Australia)

    2013-06-05

    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 {sup 1}H 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{sup −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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  19. High-throughput nuclear magnetic resonance metabolomic footprinting for tissue engineering.

    Science.gov (United States)

    Seagle, Christopher; Christie, Megan A; Winnike, Jason H; McClelland, Randall E; Ludlow, John W; O'Connell, Thomas M; Gamcsik, Michael P; MacDonald, Jeffrey M

    2008-06-01

    We report a high-throughput (HTP) nuclear magnetic resonance (NMR) method for analysis of media components and a metabolic schematic to help easily interpret the data. Spin-lattice relaxation values and concentrations were measured for 19 components and 2 internal referencing agents in pure and 2-day conditioned, hormonally defined media from a 3-dimensional (3D) multicoaxial human bioartificial liver (BAL). The (1)H NMR spectral signal-to-noise ratio is 21 for 0.16 mM alanine in medium and is obtained in 12 min using a 400 MHz NMR spectrometer. For comparison, 2D gel cultures and 3D multicoaxial BALs were batch cultured, with medium changed every day for 15 days after inoculation with human liver cells in Matrigel-collagen type 1 gels. Glutamine consumption was higher by day 8 in the BAL than in 2D culture; lactate production was lower through the 15-day culture period. Alanine was the primary amino acid produced and tracked with lactate or urea production. Glucose and pyruvate consumption were similar in the BAL and 2D cultures. NMR analysis permits quality assurance of the bioreactor by identifying contaminants. Ethanol was observed because of a bioreactor membrane "wetting" procedure. A biochemical scheme is presented illustrating bioreactor metabolomic footprint results and demonstrating how this can be translated to modify bioreactor operational parameters or quality assurance issues.

  20. Nuclear magnetic resonance experiments with dc SQUID amplifiers

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-11-01

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

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

    Science.gov (United States)

    Friedrich, Jan O.

    1988-12-01

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

  2. Novel nuclear magnetic resonance techniques for studying biological molecules

    Energy Technology Data Exchange (ETDEWEB)

    Laws, David D.

    2000-06-01

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

  3. Nuclear magnetic resonance experiments with DC SQUID amplifiers

    Science.gov (United States)

    Heaney, M. B.

    1990-11-01

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

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

    Institute of Scientific and Technical Information of China (English)

    WANG; Weimin(

    2001-01-01

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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2016-12-01

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

  7. Advances in Nuclear Magnetic Resonance for Drug Discovery

    Science.gov (United States)

    Powers, Robert

    2010-01-01

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

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

    Science.gov (United States)

    Maltsev, Sergey; Lorigan, Gary A

    2011-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    J. Hendricks; T. Yao; A. Kearns

    1999-01-21

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

  10. Updated methodology for nuclear magnetic resonance characterization of shales

    Science.gov (United States)

    Washburn, Kathryn E.; Birdwell, Justin E.

    2013-01-01

    Unconventional petroleum resources, particularly in shales, are expected to play an increasingly important role in the world’s energy portfolio in the coming years. Nuclear magnetic resonance (NMR), particularly at low-field, provides important information in the evaluation of shale resources. Most of the low-field NMR analyses performed on shale samples rely heavily on standard T1 and T2 measurements. We present a new approach using solid echoes in the measurement of T1 and T1–T2 correlations that addresses some of the challenges encountered when making NMR measurements on shale samples compared to conventional reservoir rocks. Combining these techniques with standard T1 and T2 measurements provides a more complete assessment of the hydrogen-bearing constituents (e.g., bitumen, kerogen, clay-bound water) in shale samples. These methods are applied to immature and pyrolyzed oil shale samples to examine the solid and highly viscous organic phases present during the petroleum generation process. The solid echo measurements produce additional signal in the oil shale samples compared to the standard methodologies, indicating the presence of components undergoing homonuclear dipolar coupling. The results presented here include the first low-field NMR measurements performed on kerogen as well as detailed NMR analysis of highly viscous thermally generated bitumen present in pyrolyzed oil shale.

  11. Two-dimensional nuclear magnetic resonance of quadrupolar systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuanhu

    1997-09-17

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

  12. Effect of fertilizers on galanthamine and metabolite profiles in Narcissus bulbs by 1H NMR.

    Science.gov (United States)

    Lubbe, Andrea; Choi, Young Hae; Vreeburg, Peter; Verpoorte, Robert

    2011-04-13

    Narcissus bulbs contain the biologically active alkaloid galanthamine, and Narcissus is being developed as a natural source of the molecule for the pharmaceutical industry. The effect of fertilizer on galanthamine production was investigated in a field study using a (1)H nuclear magnetic resonance (NMR) metabolite profiling approach. Galanthamine was quantitated and major metabolites in the bulbs were identified. The application of standard fertilization levels of nitrogen and potassium caused a significant increase in galanthamine as compared to a control. Multivariate data analysis of the (1)H NMR data revealed that applying double the standard level of nitrogen fertilizer resulted in production of more amino acids and citric acid cycle intermediates, but not more galanthamine. The results indicated that standard levels of fertilizer currently applied in The Netherlands are sufficient for optimal galanthamine accumulation in the bulbs. This study shows how (1)H NMR-based metabolic profiling can provide insight into the response of plant metabolism to agricultural practices.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Science.gov (United States)

    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.

  15. ¹H Nuclear Magnetic Resonance monitoring of the degradation of margarines of varied compositions when heated to high temperature.

    Science.gov (United States)

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

    2014-12-15

    In this study, (1)H Nuclear Magnetic Resonance was used to monitor the evolution of three margarines of varied compositions when submitted to heating at 180°C in an oven with aeration. Heating causes degradation of polyunsaturated acyl groups and this depends not only on their unsaturation degree, but also on the concentration of the different acyl groups. The evolution of monounsaturated groups varies depending on the disappearance rate of the groups with higher unsaturation degree. Heat treatment also causes hydrolysis reactions that lead to a reduction in 1-monoglycerides and an increase in 1,2-diglycerides, especially in the margarines with higher water content, as well as degradation of some vegetable sterols. Different types of aldehydes and epoxides were identified and quantified, above all in the margarine with the highest proportion of polyunsaturated groups, especially linoleic; some of these are toxic, such as 4-hydroxy- and 4,5-epoxy-2-alkenals.

  16. Nuclear Magnetic Resonance-Based Metabolic Comparative Analysis of Two Apple Varieties with Different Resistances to Apple Scab Attacks.

    Science.gov (United States)

    Sciubba, Fabio; Di Cocco, Maria Enrica; Gianferri, Raffaella; Capuani, Giorgio; De Salvador, Flavio Roberto; Fontanari, Marco; Gorietti, Daniela; Delfini, Maurizio

    2015-09-23

    Apple scab, caused by the fungus Venturia inaequalis, is the most serious disease of the apple worldwide. Two cultivars (Malus domestica), having different degrees of resistance against fungi attacks, were analyzed by (1)H and (13)C nuclear magnetic resonance (NMR) spectroscopy. Aqueous and organic extracts of both apple flesh and skin were studied, and over 30 metabolites, classified as organic acids, amino acids, carbohydrates, phenolic compounds, lipids, sterols, and other metabolites, were quantified by means of one-dimensional (1D) and two-dimensional (2D) NMR experiments. The metabolic profiles of the two apple cultivars were compared, and the differences were correlated with the different degrees of resistance to apple scab by means of univariate analysis. Levels of metabolites with known antifungal activity were observed not only to be higher in the Almagold cultivar but also to show different correlation patterns in comparison to Golden Delicious, implying a difference in the metabolic network involved in their biosynthesis.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

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

  18. Novel nuclear magnetic resonance techniques for studying biological molecules

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-06-01

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

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

    Science.gov (United States)

    Cleveland, Zackary I.

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

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

    CERN Document Server

    Afanasiev, A V

    2000-01-01

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

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

    CERN Document Server

    Bordbar, G H

    2015-01-01

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

  2. Nuclear magnetic resonance studies of macroscopic morphology and dynamics

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-09-01

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

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

    Directory of Open Access Journals (Sweden)

    Hossein Pourmodheji

    2016-06-01

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

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

    Science.gov (United States)

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

    2016-06-09

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-12-31

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

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

    Directory of Open Access Journals (Sweden)

    Fraceto Leonardo Fernandes

    2004-01-01

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

  7. Relativistic effects in the intermolecular interaction-induced nuclear magnetic resonance parameters of xenon dimer

    DEFF Research Database (Denmark)

    Hanni, Matti; Lantto, Perttu; Ilias, Miroslav;

    2007-01-01

    Relativistic effects on the 129Xe nuclear magnetic resonance shielding and 131Xe nuclear quadrupole coupling (NQC) tensors are examined in the weakly bound Xe2 system at different levels of theory including the relativistic four-component Dirac-Hartree-Fock (DHF) method. The intermolecular...

  8. Profiling formulated monoclonal antibodies by (1)H NMR spectroscopy.

    Science.gov (United States)

    Poppe, Leszek; Jordan, John B; Lawson, Ken; Jerums, Matthew; Apostol, Izydor; Schnier, Paul D

    2013-10-15

    Nuclear magnetic resonance (NMR) is arguably the most direct methodology for characterizing the higher-order structure of proteins in solution. Structural characterization of proteins by NMR typically utilizes heteronuclear experiments. However, for formulated monoclonal antibody (mAb) therapeutics, the use of these approaches is not currently tenable due to the requirements of isotope labeling, the large size of the proteins, and the restraints imposed by various formulations. Here, we present a new strategy to characterize formulated mAbs using (1)H NMR. This method, based on the pulsed field gradient stimulated echo (PGSTE) experiment, facilitates the use of (1)H NMR to generate highly resolved spectra of intact mAbs in their formulation buffers. This method of data acquisition, along with postacquisition signal processing, allows the generation of structural and hydrodynamic profiles of antibodies. We demonstrate how variation of the PGSTE pulse sequence parameters allows proton relaxation rates and relative diffusion coefficients to be obtained in a simple fashion. This new methodology can be used as a robust way to compare and characterize mAb therapeutics.

  9. (13C-(13c homonuclear recoupling in solid-state nuclear magnetic resonance at a moderately high magic-angle-spinning frequency.

    Directory of Open Access Journals (Sweden)

    Venus Singh Mithu

    Full Text Available Two-dimensional (13C-(13C correlation experiments are widely employed in structure determination of protein assemblies using solid-state nuclear magnetic resonance. Here, we investigate the process of (13C-(13C magnetisation transfer at a moderate magic-angle-spinning frequency of 30 kHz using some of the prominent second-order dipolar recoupling schemes. The effect of isotropic chemical-shift difference and spatial distance between two carbons and amplitude of radio frequency on (1H channel on the magnetisation transfer efficiency of these schemes is discussed in detail.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

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

    2016-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Bielecki, A.

    1987-05-01

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

  13. H Nuclear magnetic resonance based metabonomics data analysis in rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Mohammad Arjmand

    2014-05-01

    Full Text Available Background: Rheumatoid arthritis (RA is a chronic, systematic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints and it is a common rheumatic disease with many subtypes. Nuclear Magnetic resonance (1H NMR spectrometers with high sensitivity, resolution and dynamic range has permitted the rapid, simultaneous investigation of complex mixtures of endogenous or exogenous components present in biological materials. Metabonomics is the systematic study of chemical finger print resulted from cell reactions and could be used as a new biomarker for early disease diagnosis. In the present investigation, we studied serum metabolic profile in rheumatoid arthritis (RA in order to find out the metabolic finger print pattern of the disease. Materials and methods: In our metabonomics study serum samples were collected from 16 patients with active RA, and from equal number of healthy subjects. They were evaluated during a one-year follow-up with the assessment of disease activity and 1H NMR spectroscopy of sera samples. In all the cases, the presence of active rheumatoid arthritis was shown by an increase in the T1 values of the synovium of the joints. We specified and classified all metabolites using PCA, PLSDA chemometrics methods. Chenomx (Trail Version and ProMetab codes in Matlab software environments were used for our data analysis. Results were compared with the NMR metabolite data bank (www.metabolomics.ca. Anti-CCP, ANA and urea were also analyzed by ElISA and colorimetric methods respectively. Results: The most changes identified in this study were in the biosynthesis pathways of steroid hormones, biotin, fatty acids, amino acids (Leucine, Valin and isoleucine and also linoleic acid. Conclusion: In rheumatoid arthritis disease, the activation of the immune system consumes larg amounts of energy. The main donor of free energy in cells is ATP, which is generated by both glycolysis and oxidative

  14. Sensitivity of 1H NMR analysis of rat urine in relation to toxicometabonomics. Part I: Dose-dependent toxic fffects of Bromobenzene and paracetamol

    NARCIS (Netherlands)

    Schoonen, W.G.E.J.; Kloks, C.P.A.M.; Ploemen, J.P.H.T.M.; Horbach, G.J.; Smit, M.J.; Zandberg, P.; Mellema, J.R.; Zuylen, C.T. van; Tas, A.C.; Nesselrooij, J.H.J. van; Vogels, J.T.W.E.

    2007-01-01

    1H nuclear magnetic resonance (NMR) spectroscopy of rat urine in combination with pattern recognition analysis was evaluated for early noninvasive detection of toxicity of investigational chemical entities. Bromobenzene (B) and paracetamol (P) were administered at five single oral dosages between 2

  15. Kinetic and equilibrium constants of phytic acid and ferric and ferrous phytate derived from nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Heighton, Lynne; Schmidt, Walter F; Siefert, Ronald L

    2008-10-22

    Inositol phosphates are metabolically derived organic phosphates (P) that increasingly appear to be an important sink and source of P in the environment. Salts of myo-inositol hexakisdihydrogen phosphate (IHP) or more commonly phytate are the most common inositol phosphates in the environment. IHP resists acidic dephosphorylation and enzymatic dephosphorylation as ferric or ferrous IHP. Mobility of IHP iron complexes is potentially pH and redox responsive, making the time scale and environmental fate and transport of the P associated with the IHP of interest to the mass balance of phosphorus. Ferric and ferrous complexes of IHP were investigated by proton nuclear magnetic resonance spectroscopy ( (1)H NMR) and enzymatic dephosphorylation. Ferrous IHP was found to form quickly and persist for a longer period then ferric IHP. Dissociation constants derived from (1)H NMR experiments of chemically exchanging systems at equilibrium were 1.11 and 1.19 and formation constants were 0.90 and 0.84 for ferric and ferrous IHP, respectively. The recovery of P from enzymatic dephosphorylation of ferric and ferrous IHP was consistent with the magnitude of the kinetic and equilibrium rate constants.

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

    Science.gov (United States)

    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.

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

    CERN Document Server

    Aguirre, R

    2014-01-01

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

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

    CERN Document Server

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

    2009-01-01

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

  19. Rotor Design for High Pressure Magic Angle Spinning Nuclear Magnetic Resonance

    Energy Technology Data Exchange (ETDEWEB)

    Turcu, Romulus VF; Hoyt, David W.; Rosso, Kevin M.; Sears, Jesse A.; Loring, John S.; Felmy, Andrew R.; Hu, Jian Z.

    2013-01-01

    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.

  20. Rotor design for high pressure magic angle spinning nuclear magnetic resonance

    Science.gov (United States)

    Turcu, Romulus V. F.; Hoyt, David W.; Rosso, Kevin M.; Sears, Jesse A.; Loring, John S.; Felmy, Andrew R.; Hu, Jian Zhi

    2013-01-01

    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 °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.

  1. Three dimensional nuclear magnetic resonance spectroscopic imaging of sodium ions using stochastic excitation and oscillating gradients

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Energetics of endurance exercise in young horses determined by nuclear magnetic resonance metabolomics

    Directory of Open Access Journals (Sweden)

    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.

  3. 1 H-Magnetic Resonance Spectroscopy Study of Auditory Cortex Metabolism in Patients with Type 2 Diabetes%2型糖尿病患者听皮层区磁共振氢质子波谱分析

    Institute of Scientific and Technical Information of China (English)

    宋冬梅; 徐英霞; 刘涛; 吕欣; 王宝山

    2015-01-01

    Objective To investigate the characteristic changes of the metabolism products in the auditory cortex (transverse temporal gyrus) in diabetes combined with nerve deafness using 1 H magnetic resonance spectros‐copy (1 H -MRS) ,and to discover the early warning indicator of nerve deafness in type 2 diabetes .Methods PTA was performed in 98 patients with type 2 diabetes (diagnosed by Endocrinology Department) ,and in 15 healthy sub‐jects in the control group .The patients were classified into four groups :the group of type 2 diabetes;type 2 diabe‐tes with unilateral and bilateral deafness ,and the normal control group .Cerebral metabolism was studied by assess‐ing the ratios of nitro -acetyl aspartate contrast to choline (NAA/Cho) as well as to creatine (NAA/Cr) ,myo-in‐ositol to creatine (mI/Cr) and choline to creatine (Cho/Cr) ratios in the auditory cortical separately in these groups . The Pearson correlation analysis was applied to determine blood glucose value with the nerve metabolites while the ROC curves were made for those metabolism markers to find the best diagnostic threshold .Results NAA/Cr and NAA/Cho were negatively correlated with AHI index and Cho/Cr ,mI/Cr was positively correlated with blood glu‐cose value .Significantly lower values of NAA/Cho ratio were found in patients'(diabetes without deafness) auditory cortex compared with 15 age-matched control subjects (P<0 .05) .NAA/Cr and NAA/Cho ratio in diabetes with deafness were significantly lower than those in control group (P< 0 .05) ,Cho/Cr higher than those of in other groups (P<0 .05) .NAA/Cr and NAA/Cho ratio in injured and uninjured auditory cortex of diabetes with unilateral deafness were significantly lower than those of in control group (P<0 .05) ,then we made a self -comparison be‐tween the injured and uninjured auditory cortex ,finding that NAA/Cho ratio had a significant difference .All of the metabolisms were tested by the curve of ROC .The area of NAA/Cho under the ROC

  4. Bulk carbohydrate grain filling of barley ß-glucan mutants studied by 1H HR MAS NMR

    DEFF Research Database (Denmark)

    Seefeldt, Helene Fast; Larsen, Flemming Hofmann; Viereck, Nanna;

    2008-01-01

    ) during grain filling. For the first time, 1H HR MAS NMR spectra of flour from immature barley seeds are analyzed. Spectral assignments are made using two-dimensional (2D) NMR methods. Both α- and β-glucan biosynthesis were characterized by inspection of the spectra as well as by calibration......Temporal and genotypic differences in bulk carbohydrate accumulation in three barley genotypes differing in the content of mixed linkage β-(1→3),(1→4)-D-glucan (β-glucan) and starch were investigated using proton high-resolution, magic angle spinning, nuclear magnetic resonance (1H HR MAS NMR...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    DEFF Research Database (Denmark)

    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. Conseque...

  7. Quantitative determination Of etimicin sulfate by nuclear magnetic resonance%核磁共振法测定硫酸依替米星含量

    Institute of Scientific and Technical Information of China (English)

    于小波; 相秉仁; 王国华; 宋喆; 沈文斌

    2011-01-01

    Qualitative and quantitative analysis of etimicin sulfate were reported by nuclear magnetic resonance(NMR).The 1H-NMR and 13C-NMR spectra of etimicin sulfate have been assigned by means of 1D and 2D spectroscopy including DEPT, COSY, HSQC and HMBC.On the basis of assignment, a novel approach was developed for the determination of purity of etimicin sulfate by proton-nuclear magnetic resonance (1H-NMR)using p-hydroquinone as internal standard.The result showed that the purity of etimicin was 59.19%, and its relative standard deviations(RSD) was 0.24%, this method was relative accuracy, precision, and ease of application.%通过核磁共振法对硫酸依替米星进行定性和定量分析.利用一维及二维核磁共振谱(DEPT、COSY、HSQC、HMBC),对H-NMR谱和C-NMR谱信号进行完整归属.在此基础上,采用氢核磁共振定量法,以对苯二酚为内标,测得硫酸依替米星中依替米星的含量为59.19%,RSD为0.24%,方法准确可靠,简便快速.

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

    Science.gov (United States)

    Makulski, Włodzimierz

    2015-04-01

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

  9. Nuclear magnetic resonance detection and spectroscopy of single proteins using quantum logic.

    Science.gov (United States)

    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

    2016-02-19

    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.

  10. Nuclear magnetic relaxation studies of semiconductor nanocrystals and solids

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    CERN Document Server

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

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  13. Nuclear magnetic resonance J coupling constant polarizabilities of hydrogen peroxide

    DEFF Research Database (Denmark)

    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...

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

    Science.gov (United States)

    Okvátovity, Zoltán; Simon, Ferenc; Dóra, Balázs

    2016-12-01

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

  15. NMR in pulsed magnetic field

    KAUST Repository

    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.

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

    Science.gov (United States)

    Blanchard, John Woodland

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

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

    Science.gov (United States)

    2015-11-01

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

  18. 1H MAS NMR spectra of hy- droxyl species on diatomite surface

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

  20. Translational diffusion in paramagnetic liquids by 1H NMR relaxometry: nitroxide radicals in solution.

    Science.gov (United States)

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

    2013-01-14

    For nitroxide radicals in solution one can identify three frequency regimes in which (1)H spin-lattice relaxation rate of solvent molecules depend linearly on square root of the (1)H 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)] with properties of the spectral density function associated with translational dynamics, relationships between the corresponding linear changes of the relaxation rate (for (14)N spin probes) and relative translational diffusion coefficient of the solvent and solute molecules have been derived (in analogy to (15)N spin probes [E. Belorizky et al., J. Phys. Chem. A 102, 3674 (1998)]). This method allows a simple and straightforward determination of diffusion coefficients in spin-labeled systems, by means of (1)H nuclear magnetic resonance (NMR) relaxometry. The approach has thoroughly been tested by applying to a large set of experimental data-(1)H spin-lattice relaxation dispersion results for solutions of different viscosity (decalin, glycerol, propylene glycol) of (14)N and (15)N 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 (1)H 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.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Watkins, Joel C.; Fukushima, Eiichi

    1988-06-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-14

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

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

    Institute of Scientific and Technical Information of China (English)

    杨保联; 冯继文; 周建威; 李丽云; 叶朝辉

    1999-01-01

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

  5. Quantitative Analysis of Nail Polish Remover Using Nuclear Magnetic Resonance Spectroscopy Revisited

    Science.gov (United States)

    Hoffmann, Markus M.; Caccamis, Joshua T.; Heitz, Mark P.; Schlecht, Kenneth D.

    2008-01-01

    Substantial modifications are presented for a previously described experiment using nuclear magnetic resonance (NMR) spectroscopy to quantitatively determine analytes in commercial nail polish remover. The revised experiment is intended for a second- or third-year laboratory course in analytical chemistry and can be conducted for larger laboratory…

  6. The Complexation of the Na(super +) by 18-Crown-6 Studied via Nuclear Magnetic Resonance

    Science.gov (United States)

    Peters, Steven J.; Stevenson, Cheryl D.

    2004-01-01

    A student friendly experiment that teaches several important concepts of modern nuclear magnetic resonance (NMR), like multinuclear capabilities, the NMR time scale, and time-averaged signals, is described along with some important concepts of thermo chemical equilibria. The mentioned experiment involves safe and inexpensive compounds, such as…

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

    NARCIS (Netherlands)

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

    2004-01-01

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

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

    Science.gov (United States)

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

    1980-09-01

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

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

    Institute of Scientific and Technical Information of China (English)

    林东海; 吴钦义

    1994-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-04-24

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

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

    DEFF Research Database (Denmark)

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

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

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

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

    Science.gov (United States)

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

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

    Science.gov (United States)

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

    2008-02-19

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

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    Science.gov (United States)

    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.

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

    CERN Document Server

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

    2008-01-01

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

  19. Chemical structures in pyrodextrin determined by nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Bai, Yanjie; Shi, Yong-Cheng

    2016-10-20

    Glycosidic linkages in a pyrodextrin were identified by NMR spectroscopy for the first time. Pyrodextrin was prepared by slurrying waxy maize starch at pH 3, filtering and drying at 40°C to 10-15% moisture content, then heating at 170°C for 4h. (1)H and (13)C NMR resonances of the pyrodextrin were assigned with the assistance of 2D techniques including COSY, TOCSY, HSQC, and HMBC, all measured on a 500MHz instrument. During dextrinization, native waxy maize starch was hydrolyzed and extensively branched with new glycosidic linkages. The resulting pyrodextrin became 100% soluble in water and produced lower viscosity solutions at 30% solids. There were only 1.2% reducing ends (α-form) detected in the pyrodextrin, but 1,6-anhydro-β-d-glucopyranosyl units accounted for 5.2% of repeating units and they were thought to be at the potential reducing end. New glycosyl linkages including α-1,6, β-1,6, α-1,2, and β-1,2 were identified. The total non-α-1,4 linkages in the pyrodextrin were about 17.8% compared to 5.8% in a maltodextrin prepared by α-amylase digestion. Transglycosidation and depolymerization occurred during dextrinization, and the resulting pyrodextrin was highly branched.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-21

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

  1. Nuclear magnetic resonance relaxation and diffusion in the presence of internal gradients: the effect of magnetic field strength.

    Science.gov (United States)

    Mitchell, J; Chandrasekera, T C; Johns, M L; Gladden, L F; Fordham, E J

    2010-02-01

    It is known that internal magnetic field gradients in porous materials, caused by susceptibility differences at the solid-fluid interfaces, alter the observed effective Nuclear Magnetic Resonance transverse relaxation times T2,eff. The internal gradients scale with the strength of the static background magnetic field B0. Here, we acquire data at various magnitudes of B0 to observe the influence of internal gradients on T2-T2 exchange measurements; the theory discussed and observations made are applicable to any T2-T2 analysis of heterogeneous materials. At high magnetic field strengths, it is possible to observe diffusive exchange between regions of local internal gradient extrema within individual pores. Therefore, the observed exchange pathways are not associated with pore-to-pore exchange. Understanding the significance of internal gradients in transverse relaxation measurements is critical to interpreting these results. We present the example of water in porous sandstone rock and offer a guideline to determine whether an observed T2,eff relaxation time distribution reflects the pore size distribution for a given susceptibility contrast (magnetic field strength) and spin echo separation. More generally, we confirm that for porous materials T1 provides a better indication of the pore size distribution than T2,eff at high magnetic field strengths (B0>1 T), and demonstrate the data analysis necessary to validate pore size interpretations of T2,eff measurements.

  2. The prowess of proton magnetic resonance spectroscopy on the radiation-induced injury of brain%放射性脑损伤1H-MRS研究进展

    Institute of Scientific and Technical Information of China (English)

    王宏琢; 邱士军

    2009-01-01

    放射性脑损伤是颅内肿瘤放射治疗后的常见并发症,近年来1H-MRS在放射性脑损伤的早期诊断及与肿瘤复发鉴别方面的研究发展迅速.就放射性脑损伤的发病机制、1H-MRS研究进展及存在的问题予以综述.

  3. Nuclear magnetic resonance on selected lithium based compounds

    Energy Technology Data Exchange (ETDEWEB)

    Rudisch, Christian

    2013-11-26

    This thesis presents the NMR measurements on the single crystals LiMnPO{sub 4} and Li{sub 0.9}FeAs. Therefore, the thesis is divided into two separated sections. The first part reports on the competitive next generation cathode material LiMnPO{sub 4} with a stable reversible capacity up to 145 mAh/g and a rather flat discharge voltage curve at 4.1 V. For the basic understanding of the material the magnetic properties have been investigated by a Li and P NMR study in the paramagnetic and antiferromagnetic phase. LiMnPO{sub 4} shows a strong anisotropy of the dipolar hyperfine coupling due to the strong local magnetic moments at the Mn site. The corresponding dipole tensor of the Li- and P-nuclei is fully determined by orientation and temperature dependent NMR experiments and compared to the calculated values from crystal structure data. Deviations of the experimentally determined values from the theoretical ones are discussed in terms of Mn disorder which could have an impact on the mobility of the Li ions. The disorder is corroborated by diffuse X-ray diffraction experiments which indicate a shift of the heavy elements in the lattice, namely the Mn atoms. Furthermore, the spin arrangement in the relative strong field of 7.0494 T in the antiferromagnetic state is understood by the NMR measurements. In order to obtain parameters of the Li ion diffusion in LiMnPO{sub 4} measurements of the spin lattice relaxation rate were performed. Due to the strong dipolar coupling between the Li-nuclei and the magnetic moments at the Mn site it is difficult to extract parameters which can characterize the diffusive behavior of the Li ions. The second section reports on the AC/DC susceptibility and NMR/NQR studies on Li deficit samples labeled as Li{sub 0.9}FeAs. LiFeAs belongs to the family of the superconducting Pnictides which are discovered in 2008 by H. Hosono et al. In recent studies the stoichiometric compound reveals triplet superconductivity below T{sub c}-18 K which

  4. Nuclear Magnetic Resonance Quantum Computing Using Liquid Crystal Solvents

    CERN Document Server

    Yannoni, C S; Vandersypen, L M K; Miller, D C; Kubinec, M G; Chuang, I L; Yannoni, Costantino S.; Sherwood, Mark H.; Vandersypen, Lieven M.K.; Miller, Dolores C.; Kubinec, Mark G.; Chuang, Isaac L.

    1999-01-01

    Liquid crystals offer several advantages as solvents for molecules used for NMR quantum computing (NMRQC). The dipolar coupling between nuclear spins manifest in the NMR spectra of molecules oriented by a liquid crystal permits a significant increase in clock frequency, while short spin-lattice relaxation times permit fast recycling of algorithms, and save time in calibration and signal-enhancement experiments. Furthermore, the use of liquid crystal solvents offers scalability in the form of an expanded library of spin-bearing molecules suitable for NMRQC. These ideas are demonstrated with the successful execution of a 2-qubit Grover search using a molecule ($^{13}$C$^{1}$HCl$_3$) oriented in a liquid crystal and a clock speed eight times greater than in an isotropic solvent. Perhaps more importantly, five times as many logic operations can be executed within the coherence time using the liquid crystal solvent.

  5. Characterization of metabolic profile of intact non-tumor and tumor breast cells by high-resolution magic angle spinning nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Maria, Roberta M; Altei, Wanessa F; Andricopulo, Adriano D; Becceneri, Amanda B; Cominetti, Márcia R; Venâncio, Tiago; Colnago, Luiz A

    2015-11-01

    (1)H high-resolution magic angle spinning nuclear magnetic resonance ((1)H HR-MAS NMR) spectroscopy was used to analyze the metabolic profile of an intact non-tumor breast cell line (MCF-10A) and intact breast tumor cell lines (MCF-7 and MDA-MB-231). In the spectra of MCF-10A cells, six metabolites were assigned, with glucose and ethanol in higher concentrations. Fifteen metabolites were assigned in MCF-7 and MDA-MB-231 (1)H HR-MAS NMR spectra. They did not show glucose and ethanol, and the major component in both tumor cells was phosphocholine (higher in MDA-MB-231 than in MCF-7), which can be considered as a tumor biomarker of breast cancer malignant transformation. These tumor cells also show acetone signal that was higher in MDA-MB-231 cells than in MCF-7 cells. The high acetone level may be an indication of high demand for energy in MDA-MB-231 to maintain cell proliferation. The higher acetone and phosphocholine levels in MDA-MB-231 cells indicate the higher malignance of the cell line. Therefore, HR-MAS is a rapid reproducible method to study the metabolic profile of intact breast cells, with minimal sample preparation and contamination, which are critical in the analyses of slow-growth cells.

  6. (1)H, (13)C and (15)N resonance assignment of the first N-terminal RNA recognition motif (RRM) of the human heterogeneous nuclear ribonucleoprotein H (hnRNP H).

    Science.gov (United States)

    Cabal, Stéphanie; van Heijenoort, Carine; Guittet, Eric

    2007-12-01

    Human heterogeneous nuclear ribonucleoprotein H (hnRNP H) regulates alternative splicing of HIV-1 Tat pre-mRNA. The structure of the first N-terminal domain (residues 1-104) of hnRNP H was solved and its binding to an exonic splicing silencer (pESS2) studied. For this, all backbone and 85% of side-chain resonance frequencies were assigned.

  7. Energy Moment Method Applied to Nuclear Quadrupole Splitting of Nuclear Magnetic Resonance Lines

    DEFF Research Database (Denmark)

    Frank, V

    1962-01-01

    Expressions giving the sum of the energy values, raised to the second and third power, for a nucleus interacting with a static magnetic field and a static electric field gradient are derived. Several applications of this method for obtaining the values of the components of the electric field...

  8. 1H MAS and 1H --> 31P CP/MAS NMR study of human bone mineral.

    Science.gov (United States)

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

    2003-11-01

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

  9. Solid State Nuclear Magnetic Resonance Investigation of Polymer Backbone Dynamics in Poly(Ethylene Oxide) Based Lithium and Sodium Polyether-ester-sulfonate Ionomers

    Energy Technology Data Exchange (ETDEWEB)

    Roach, David J.; Dou, Shichen; Colby, Ralph H.; Mueller, Karl T.

    2013-01-01

    Polymer backbone dynamics of single ion conducting poly(ethylene oxide) (PEO)-based ionomer samples with low glass transition temperatures (Tg) have been investigated using solid-state nuclear magnetic resonance (NMR). Experiments detecting 13C with 1H decoupling under magic angle spinning (MAS) conditions identified the different components of the polymer backbone (PEO spacer and isophthalate groups) and their relative mobilities for a suite of lithium- and sodium-containing ionomer samples with varying cation contents. Variable temperature (203-373 K) 1H-13C cross-polarization MAS (CP-MAS) experiments also provided qualitative assessment of the differences in the motions of the polymer backbone components as a function of cation content and identity. Each of the main backbone components exhibit distinct motions, following the trends expected for motional characteristics based on earlier Quasi Elastic Neutron Scattering and 1H spin-lattice relaxation rate measurements. Previous 1H and 7Li spin-lattice relaxation measurements focused on both the polymer backbone and cation motion on the nanosecond timescale. The studies presented here assess the slower timescale motion of the polymer backbone allowing for a more comprehensive understanding of the polymer dynamics. The temperature dependences of 13C linewidths were used to both qualitatively and quantitatively examine the effects of cation content and identity on PEO spacer mobility. Variable contact time 1H-13C CP-MAS experiments were used to further assess the motions of the polymer backbone on the microsecond timescale. The motion of the PEO spacer, reported via the rate of magnetization transfer from 1H to 13C nuclei, becomes similar for T ≳ 1.1 Tg in all ionic samples, indicating that at similar elevated reduced temperatures the motions of the polymer backbones on the microsecond timescale become insensitive to ion interactions. These results present an improved picture, beyond those of previous findings, for

  10. Nuclear Magnetic Resonance Investigation of Dynamics in Poly(Ethylene Oxide) Based Lithium Polyether-ester-sulfonate Ionomers

    Energy Technology Data Exchange (ETDEWEB)

    Roach, David J.; Dou, Shichen; Colby, Ralph H.; Mueller, Karl T.

    2012-01-07

    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 analyzed in samples with a range of ion contents. The temperature dependence of T1 values along with the presence of minima in T1 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 of both the polymer and lithium ions in the lower ion content samples indicate that the polymer segmental motion and lithium ion hopping motion are correlated 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 due to the presence of ionic aggregation. Details about 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.

  11. Evaluation of cartilage composition and degradation by high-resolution magic-angle spinning nuclear magnetic resonance.

    Science.gov (United States)

    Schiller, Jürgen; Huster, Daniel; Fuchs, Beate; Naji, Lama; Kaufmann, Jörn; Arnold, Klaus

    2004-01-01

    Rheumatic diseases are accompanied by a progressive destruction of the cartilage layers of the joints. Although the number of patients suffering from rheumatic diseases is steadily increasing, degradation mechanisms of cartilage are not yet understood, and methods for early diagnosis are not available. Although some information on pathogenesis could be obtained from the nuclear magnetic resonance (NMR) spectra of degradation products in the supernatants of cartilage specimens incubated with degradation-causing agents, the most direct information on degradation processes would come from the native cartilage as such. To obtain highly resolved NMR spectra of cartilage, application of the recently developed high-resolution magic-angle spinning (HR-MAS) NMR technique is advisable to obtain small line-widths of individual cartilage resonances. This technique is nowadays commercially available for most NMR spectrometers and has the considerable advantage that the same pulse sequences as in high-resolution NMR can be applied. Except for a MAS spinning equipment, no solid-state NMR hardware is required. Therefore, this method can be easily implemented. Here, we describe the most important requirements that are necessary to record HR-MAS NMR spectra. The capabilities of the HR-MAS technique are discussed for the 1H and 13C NMR spectra of cartilage.

  12. Zebrafish brain lipid characterization and quantification by ¹H nuclear magnetic resonance spectroscopy and MALDI-TOF mass spectrometry.

    Science.gov (United States)

    van Amerongen, Yvonne F; Roy, Upasana; Spaink, Herman P; de Groot, Huub J M; Huster, Daniel; Schiller, Jürgen; Alia, A

    2014-06-01

    Lipids play an important role in many neurodegenerative diseases, such as Parkinson's disease, Alzheimer's disease, and Huntington's disease. Zebrafish models for these diseases have been recently developed. The detailed brain lipid composition of the adult zebrafish is not known, and therefore, the representativeness of these models cannot be properly evaluated. In this study, we characterized the total lipid composition of healthy adult zebrafish using (1)H nuclear magnetic resonance spectroscopy. A close resemblance of the zebrafish brain composition is shown in comparison to the human brain. Moreover, several lipids involved in the pathogenesis of neurodegenerative diseases (i.e., cholesterol, phosphatidylcholine, docosahexaenoic acid, and further, polyunsaturated fatty acids) are detected and quantified. These lipids might represent useful biomarkers in future research toward human therapies. Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry coupled with high-performance thin-layer chromatography was used for further characterization of zebrafish brain lipids. Our results show that the lipid composition of the zebrafish brain is rather similar to the human brain and thus confirms that zebrafish represents a good model for studying various brain diseases.

  13. Clustering dynamics in water/methanol mixtures: a nuclear magnetic resonance study at 205 k

    Science.gov (United States)

    Corsaro, Carmelo; Spooren, Jeroen; Branca, Caterina; Leone, Nancy; Broccio, Matteo; Kim, Chansoo; Chen, Sow-Hsin; Stanley, H Eugene; Mallamace, Francesco

    2008-08-28

    Proton nuclear magnetic resonance (1H NMR) experiments have been performed to measure the spin-lattice, T1, and spin-spin, T2, relaxation times of the three functional groups in water/methanol mixtures at different methanol molar fractions (XMeOH=0, 0.04, 0.1, 0.24, 0.5, 1) as a function of temperature in the range 205 K

  14. Structural characterization of a poly(methacrylic acid)-poly(methyl methacrylate) copolymer by nuclear magnetic resonance and mass spectrometry.

    Science.gov (United States)

    Giordanengo, Rémi; Viel, Stéphane; Hidalgo, Manuel; Allard-Breton, Béatrice; Thévand, André; Charles, Laurence

    2009-11-03

    Mass spectrometry (MS) and nuclear magnetic resonance (NMR) have been combined to achieve the complete microstructural characterization of a poly(methacrylic acid)-poly(methyl methacrylate) (PMAA-PMMA) copolymer synthesized by nitroxide-mediated polymerization. Various PMAA-PMMA species could be identified which mainly differ in terms of terminaisons. 1H and 13C NMR experiments revealed the structure of the end-groups as well as the proportion of each co-monomer in the copolymers. These end-group masses were further confirmed from m/z values of doubly charged copolymer anions detected in the single stage mass spectrum. In contrast, copolymer composition derived from MS data was not consistent with NMR results, obviously due to strong mass bias well known to occur during electrospray ionization of these polymeric species. Tandem mass spectrometry could reveal the random nature of the copolymer based on typical dissociation reactions, i.e., water elimination occurred from any two contiguous MAA units while MAA-MMA pairs gave rise to the loss of a methanol molecule. Polymer backbone cleavages were also observed to occur and gave low abundance fragment ions which allowed the structure of the initiating end-group to be confirmed.

  15. Structural characterization of a poly(methacrylic acid)-poly(methyl methacrylate) copolymer by nuclear magnetic resonance and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Giordanengo, Remi [Universites Aix-Marseille I, II et III - CNRS, UMR 6264: Laboratoire Chimie Provence, Spectrometries Appliquees a la Chimie Structurale, F-13397 Marseille (France); Viel, Stephane [Aix-Marseille Universite - CNRS, UMR 6263: Institut des Sciences Moleculaires de Marseille, Chimiometrie et Spectrometries, F-13397 Marseille (France); Hidalgo, Manuel; Allard-Breton, Beatrice [ARKEMA, Centre de Recherche Rhone Alpes, Rue Henri Moissan, F-69493 Pierre-Benite (France); Thevand, Andre [Universites Aix-Marseille I, II et III - CNRS, UMR 6264: Laboratoire Chimie Provence, Spectrometries Appliquees a la Chimie Structurale, F-13397 Marseille (France); Charles, Laurence, E-mail: laurence.charles@univ-provence.fr [Universites Aix-Marseille I, II et III - CNRS, UMR 6264: Laboratoire Chimie Provence, Spectrometries Appliquees a la Chimie Structurale, F-13397 Marseille (France)

    2009-11-03

    Mass spectrometry (MS) and nuclear magnetic resonance (NMR) have been combined to achieve the complete microstructural characterization of a poly(methacrylic acid)-poly(methyl methacrylate) (PMAA-PMMA) copolymer synthesized by nitroxide-mediated polymerization. Various PMAA-PMMA species could be identified which mainly differ in terms of terminaisons. {sup 1}H and {sup 13}C NMR experiments revealed the structure of the end-groups as well as the proportion of each co-monomer in the copolymers. These end-group masses were further confirmed from m/z values of doubly charged copolymer anions detected in the single stage mass spectrum. In contrast, copolymer composition derived from MS data was not consistent with NMR results, obviously due to strong mass bias well known to occur during electrospray ionization of these polymeric species. Tandem mass spectrometry could reveal the random nature of the copolymer based on typical dissociation reactions, i.e., water elimination occurred from any two contiguous MAA units while MAA-MMA pairs gave rise to the loss of a methanol molecule. Polymer backbone cleavages were also observed to occur and gave low abundance fragment ions which allowed the structure of the initiating end-group to be confirmed.

  16. Nuclear magnetic resonance system with continuous flow of polarized water to obtain the traceability to static magnetic fields; Sistema de ressonancia magnetica nuclear com fluxo continuo de agua polarizada para obtencao da rastreabilidade para campos magneticos estaticos

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Ramon Valls; Nazarre, Diego Joriro, E-mail: ramon@ipt.br [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

    2013-07-01

    We have developed a system to obtain the traceability of field or magnetic induction intensity in the range of 2 μT up to 2 T, even in the presence of magnetic field gradients or noisy environments. The system is based on a nuclear magnetic resonance magnetometer, built in streaming water. The calibration procedure of a coil for magnetic field generation is described, as well as the results obtained and the estimated uncertainty (author)

  17. Experimental quantum simulation of Avian Compass in a nuclear magnetic resonance system

    Science.gov (United States)

    Pearson, Jason; Feng, GuanRu; Zheng, Chao; Long, GuiLu

    2016-12-01

    Avian magnetoreception is the capacity for avians to sense the direction of the Earth's magnetic field. Discovered more than forty years ago, it has attracted intensive studies over the years. One promising model for describing this capacity in avians is the widely used reference-and-probe model where radical pairs within the eyes of bird combines to form singlet and triplet quantum states. The yield depends on the angle between the Earth's magnetic field and the molecules' axis, hence the relative value of yield of the singlet state or triplet state enables avians to sense the direction. Here we report the experimental demonstration of avian magnetoreception in a nuclear magnetic resonance quantum information processor. It is shown clearly from the experiment that the yield of the singlet state attains maximum when it is normal to the Earth's magnetic field, and the experimental results agree with theory very well.

  18. Four-component relativistic theory for nuclear magnetic shielding: magnetically balanced gauge-including atomic orbitals.

    Science.gov (United States)

    Cheng, Lan; Xiao, Yunlong; Liu, Wenjian

    2009-12-28

    It is recognized only recently that the incorporation of the magnetic balance condition is absolutely essential for four-component relativistic theories of magnetic properties. Another important issue to be handled is the so-called gauge problem in calculations of, e.g., molecular magnetic shielding tensors with finite bases. It is shown here that the magnetic balance can be adapted to distributed gauge origins, leading to, e.g., magnetically balanced gauge-including atomic orbitals (MB-GIAOs) in which each magnetically balanced atomic orbital has its own local gauge origin placed on its center. Such a MB-GIAO scheme can be combined with any level of theory for electron correlation. The first implementation is done here at the coupled-perturbed Dirac-Kohn-Sham level. The calculated molecular magnetic shielding tensors are not only independent of the choice of gauge origin but also converge rapidly to the basis set limit. Close inspections reveal that (zeroth order) negative energy states are only important for the expansion of first order electronic core orbitals. Their contributions to the paramagnetism are therefore transferable from atoms to molecule and are essentially canceled out for chemical shifts. This allows for simplifications of the coupled-perturbed equations.

  19. Development of nuclear magnetic and quadrupole resonance spectroscopy under 10 GPa class pressure

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, R; Uchida, Y; Hirayama, K; Yamazaki, T; Fukazawa, H; Kohori, Y [Department of Physics, Graduate School of Science, Chiba University, Chiba 263-8522 (Japan); Takeshita, N, E-mail: hideto@nmr.s.chiba-u.ac.j [JST, TRIP, Chiyoda-ku, Tokyo 102-0075 (Japan)

    2010-03-01

    The high pressure nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) are conventionally performed up to 3 GPa using piston cylinder cell. However, the NMR/NQR measurements beyond this pressure range are scarcely performed owing to the technical difficulty. Recently, we developed new high pressure NMR/NQR technique using cubic anvil apparatus in which highly hydrostatic pressure was obtained. Using the new method, the {sup 63}Cu-NQR signal of Cu{sub 2}O was observed up to 7.2GPa with high sensitivity. The use of MgO gasket in mini-cubic anvil apparatus was examined for enlarging pressure range.

  20. Nuclear magnetic resonance studies of DNP-ready trehalose obtained by solid state mechanochemical amorphization.

    Science.gov (United States)

    Filibian, M; Elisei, E; Colombo Serra, S; Rosso, A; Tedoldi, F; Cesàro, A; Carretta, P

    2016-06-22

    (1)H nuclear spin-lattice relaxation and Dynamic Nuclear Polarization (DNP) have been studied in amorphous samples of trehalose sugar doped with TEMPO radicals by means of mechanical milling, in the 1.6-4.2 K temperature range. The radical concentration was varied between 0.34 and 0.81%. The highest polarization of 15% at 1.6 K, observed in the sample with concentration 0.50%, is of the same order of magnitude of that reported in standard frozen solutions with TEMPO. The temperature and concentration dependence of the spin-lattice relaxation rate 1/T1, dominated by the coupling with the electron spins, were found to follow power laws with an exponent close to 3 in all samples. The observed proportionality between 1/T1 and the polarization rate 1/Tpol, with a coefficient related to the electron polarization, is consistent with the presence of Thermal Mixing (TM) and a good contact between the nuclear and the electron spins. At high electron concentration additional relaxation channels causing a decrease in the nuclear polarization must be considered. These results provide further support for a more extensive use of amorphous DNP-ready samples, obtained by means of comilling, in dissolution DNP experiments and possibly for in vivo metabolic imaging.

  1. Residual Dipolar Couplings in Zero-to-Ultra-Low-Field Nuclear Magnetic Resonance

    CERN Document Server

    Blanchard, John W; King, Jonathan P; Ledbetter, Micah P; Levine, Emma H; Bajaj, Vikram S; Budker, Dmitry; Pines, Alexander

    2015-01-01

    Zero-to-ultra-low-field nuclear magnetic resonance (ZULF-NMR) provides a new regime for the measurement of nuclear spin-spin interactions free from effects of large magnetic fields, such as truncation of terms that do not commute with the Zeeman Hamiltonian. One such interaction, the magnetic dipole-dipole coupling, is a valuable source of spatial information in NMR, though many terms are unobservable in high-field NMR, and the interaction averages to zero under isotropic molecular tumbling. Under partial orientational ordering, this information is retained in the form of so-called residual dipolar couplings. We report zero-to-ultra-low-field NMR measurements of residual dipolar couplings in acetonitrile-2-$^{13}$C aligned in stretched polyvinyl acetate gels. This represents the first investigation of dipolar couplings as a perturbation on the indirect spin-spin $J$-coupling in the absence of an applied magnetic field. As a consequence of working at zero magnetic field, we observe terms of the dipole-dipole c...

  2. Magnetic Lenz lenses increase the limit-of-detection in nuclear magnetic resonance

    CERN Document Server

    Spengler, Nils; Meissner, Markus V; Wallrabe, Ulrike; Korvink, Jan G

    2016-01-01

    A high NMR detection sensitivity is indispensable when dealing with mass and volume-limited samples, or whenever a high spatial resolution is required. The use of miniaturised RF coils is a proven way to increase sensitivity, but may be impractical and is not applicable to every experimental situation. We present the use of magnetic lenses, denoted as Lenz lenses due to their working principle, to focus the magnetic flux of a macroscopic RF coil into a smaller volume and thereby locally enhance the sensitivity of the NMR experiment - at the expense of the total sensitive volume. Besides focusing, such lenses facilitate re-guiding or re-shaping of magnetic fields much like optical lenses do with light beams. For the first time we experimentally demonstrate the use of Lenz lenses in magnetic resonance and provide a compact mathematical description of the working principle. Through simulations we show that optimal arrangements can be found.

  3. A method for mechanical generation of radio frequency fields in nuclear magnetic resonance force microscopy

    CERN Document Server

    Wagenaar, J J T; Donkersloot, R J; Marsman, F; de Wit, M; Bossoni, L; Oosterkamp, T H

    2016-01-01

    We present an innovative method for magnetic resonance force microscopy (MRFM) with ultra-low dissipation, by using the higher modes of the mechanical detector as radio frequency (rf) source. This method allows MRFM on samples without the need to be close to an rf source. Furthermore, since rf sources require currents that give dissipation, our method enables nuclear magnetic resonance experiments at ultra-low temperatures. Removing the need for an on-chip rf source is an important step towards a MRFM which can be widely used in condensed matter physics.

  4. Generation of low-frequency electric and magnetic fields during large- scale chemical and nuclear explosions

    Energy Technology Data Exchange (ETDEWEB)

    Adushkin, V.V. [Academy of Sciences, Moscow (Russian Federation). Inst. for Dynamics of the Geospheres; Dubinya, V.A.; Karaseva, V.A.; Soloviev, S.P.; Surkov, V.V. [Lawrence Livermore National Lab., CA (United States)

    1995-06-01

    We discuss the main parameters of the electric field in the surface layer of the atmosphere and the results of the investigations of the natural electric field variations. Experimental investigations of the electromagnetic field for explosions in air are presented. Electromagnetic signals generated by underground nuclear and chemical explosions are discussed and explosions for 1976--1991 are listed. Long term anomalies of the earth`s electromagnetic field in the vicinity of underground explosions were also investigated. Study of the phenomenon of the irreversible shock magnetization showed that in the zone nearest to the explosion the quasistatic magnetic field decreases in inverse proportion to the distance.

  5. Electromagnetic properties of inner double walled carbon nanotubes investigated by nuclear magnetic resonance

    KAUST Repository

    Bouhrara, M.

    2013-01-01

    The nuclear magnetic resonance (NMR) analytical technique was used to investigate the double walled carbon nanotubes (DWNTs) electromagnetic properties of inner walls. The local magnetic and electronic properties of inner nanotubes in DWNTs were analyzed using 25% 13C enriched C 60 by which the effect of dipolar coupling could be minimized. The diamagnetic shielding was determined due to the ring currents on outer nanotubes in DWNTs. The NMR chemical shift anisotropy (CSA) spectra and spin-lattice relaxation studies reveal the metallic properties of the inner nanotubes with a signature of the spin-gap opening below 70 K.

  6. Discrimination of Aurantii Fructus Immaturus and Fructus Poniciri Trifoliatae Immaturus by Flow Injection UV Spectroscopy (FIUV) and 1H NMR using Partial Least-squares Discriminant Analysis (PLS-DA)

    Science.gov (United States)

    Two simple fingerprinting methods, flow-injection UV spectroscopy (FIUV) and 1H nuclear magnetic resonance (NMR), for discrimination of Aurantii FructusImmaturus and Fructus Poniciri TrifoliataeImmaturususing were described. Both methods were combined with partial least-squares discriminant analysis...

  7. Main: 1H49 [RPSD[Archive

    Lifescience Database Archive (English)

    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 ...

  8. Main: 1H81 [RPSD[Archive

    Lifescience Database Archive (English)

    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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    Lifescience Database Archive (English)

    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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    Lifescience Database Archive (English)

    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 ...

  11. Main: 1H83 [RPSD[Archive

    Lifescience Database Archive (English)

    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 ...

  12. Main: 1H82 [RPSD[Archive

    Lifescience Database Archive (English)

    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 ...

  13. Simulation of general three-body interactions in a nuclear magnetic resonance ensemble quantum computer

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Three-body interaction plays an important role in many-body physics,and quantum computer is efficient in simulating many-body interactions. We have experimentally demonstrated the general three-body interactions in a three-qubit nuclear magnetic resonance ensemble quantum computer. Using a nuclear magnetic resonance computer we implemented general forms of three-body interactions including σ 1x σ z2 σ x3 and σ 1x σ z2 σ y3 . The results show good agreement between theory and experiment. We have also given a concise and practical formula for a general n-body interaction in terms of one-and two-body interactions.

  14. Use of Nuclear Spin Noise Spectroscopy to Monitor Slow Magnetization Buildup at Millikelvin Temperatures

    Science.gov (United States)

    Pöschko, Maria Theresia; Peat, David; Owers‐Bradley, John

    2016-01-01

    Abstract At ultralow temperatures, longitudinal nuclear magnetic relaxation times become exceedingly long and spectral lines are very broad. These facts pose particular challenges for the measurement of NMR spectra and spin relaxation phenomena. Nuclear spin noise spectroscopy is used to monitor proton spin polarization buildup to thermal equilibrium of a mixture of glycerol, water, and copper oxide nanoparticles at 17.5 mK in a static magnetic field of 2.5 T. Relaxation times determined in such a way are essentially free from perturbations caused by excitation radiofrequency pulses, radiation damping, and insufficient excitation bandwidth. The experimental spin‐lattice relaxation times determined on resonance by saturation recovery with spin noise detection are consistently longer than those determined by using pulse excitation. These longer values are in better accordance with the expected field dependence trend than those obtained by on‐resonance experiments with pulsed excitation. PMID:27305629

  15. Analysis of antimycin A by reversed-phase liquid chromatography/nuclear magnetic-resonance spectrometry

    Science.gov (United States)

    Ha, Steven T.K.; Wilkins, Charles L.; Abidi, Sharon L.

    1989-01-01

    A mixture of closely related streptomyces fermentation products, antimycin A, Is separated, and the components are identified by using reversed-phase high-performance liquid chromatography with directly linked 400-MHz proton nuclear magnetic resonance detection. Analyses of mixtures of three amino acids, alanine, glycine, and valine, are used to determine optimal measurement conditions. Sensitivity increases of as much as a factor of 3 are achieved, at the expense of some loss in chromatographic resolution, by use of an 80-μL NMR cell, Instead of a smaller 14-μL cell. Analysis of the antimycin A mixture, using the optimal analytical high performance liquid chromatography/nuclear magnetic resonance conditions, reveals it to consist of at least 10 closely related components.

  16. Negotiated identities of chemical instrumentation: the case of nuclear magnetic resonance spectroscopy, 1956-1969.

    Science.gov (United States)

    Roberts, Jody A

    2003-05-01

    What is an NMR spectrometer? Beginning with this seemingly simple question, I will explore the development of nuclear magnetic resonance spectroscopy between the years 1956 and 1969 from two vantage points: the organic chemists who used the new instrument, and Varian Associates-the makers of the first NMR spectrometers-. Through an examination of the articles and advertisements published in the Journal of Organic Chemistry, I will draw two conclusions. First, organic chemists and Varian Associates (along with other actors) are co-responsible for the development of nuclear magnetic resonance spectroscopy (i.e., NMR spectroscopy was not created by a single actor). Second, by changing the way NMR spectrometers are used, organic chemists attempted to change to the identity of the instrument. Similarly, when Varian Associates advertised their NMR spectrometers in a different way, they, too, attempted to change the identity of the instrument.

  17. Self-energy Effects on Nuclear Magnetic Resonance Parameters within Quantum Electrodynamics Perturbation Theory

    Directory of Open Access Journals (Sweden)

    Gustavo A. Aucar

    2002-08-01

    Full Text Available Abstract: A theory for the calculation of self-energy corrections to the nuclear magnetic parameters is given in this paper. It is based on the S-matrix formulation of bound-state quantum electrodynamics (QED. Explicit expressions for the various terms of the S-matrix are given. The interpretation of the self-energy, one- and two-vertex terms and some perspective for possible future developments are discussed.

  18. Transition-Selective Pulses in Zero-Field Nuclear Magnetic Resonance.

    Science.gov (United States)

    Sjolander, Tobias F; Tayler, Michael C D; King, Jonathan P; Budker, Dmitry; Pines, Alexander

    2016-06-30

    We use low-amplitude, ultralow frequency pulses to drive nuclear spin transitions in zero and ultralow magnetic fields. In analogy to high-field NMR, a range of sophisticated experiments becomes available as these allow narrow-band excitation. As a first demonstration, pulses with excitation bandwidths 0.5-5 Hz are used for population redistribution, selective excitation, and coherence filtration. These methods are helpful when interpreting zero- and ultralow-field NMR spectra that contain a large number of transitions.

  19. Solid state nuclear magnetic resonance studies of prion peptides and proteins

    Energy Technology Data Exchange (ETDEWEB)

    Heller, Jonathan [Univ. of California, Berkeley, CA (United States)

    1997-08-01

    High-resolution structural studies using x-ray diffraction and solution nuclear magnetic resonance (NMR) are not feasible for proteins of low volubility and high tendency to aggregate. Solid state NMR (SSNMR) is in principle capable of providing structural information in such systems, however to do this efficiently and accurately, further SSNMR tools must be developed This dissertation describes the development of three new methods and their application to a biological system of interest, the priori protein (PrP).

  20. Simulation of the four-body interaction in a nuclear magnetic resonance quantum information processor

    Institute of Scientific and Technical Information of China (English)

    LIU WenZhang; ZHANG JingFu; LONG GuiLu

    2009-01-01

    The four-body interaction plays an important role in many-body systems,and it can exhibit interesting phase transition behaviors.In this letter,we report the experimental demonstration of a four-body interaction in a four-qubit nuclear magnetic resonance quantum information processor.The strongly modulating pulse is used to implement spin selective excitation.The results show a good agreement between theory and experiment.

  1. Simulating decoherence behavior of a system in entangled state using nuclear magnetic resonance

    CERN Document Server

    Zhang, J; Shan, L; Deng, Z; Zhang, Jingfu; Lu, Zhiheng; Shan, Lu; Deng, Zhiwei

    2002-01-01

    By choosing H nucleus in Carbon-13 labelled trichloroethylene as one qubit environment, and two C nuclei as a two-qubit system, we have simulated quantum decoherence when the system lies in an entangled state using nuclear magnetic resonance (NMR). Decoupling technique is used to trace over the environment degrees of freedom. Experimental results show agreements with the theoretical predictions. Our experiment scheme can be generalized to the case that environment is composed of multiple qubits.

  2. Fabrication and Magnetic Properties of Co-Doped TiO2 Powders Studied by Nuclear Magnetic Resonance

    Institute of Scientific and Technical Information of China (English)

    GE Shi-Hui; WANG Xin-Wei; KOU Xiao-Ming; ZHOU Xue-Yun; XI Li; ZUO Ya-Lu; YANG Xiao-Lin; ZHAO Yu-Xuan

    2005-01-01

    @@ Co0.04 Ti0.96 O2 powders are fabricated by sol-gel method. The structure and magnetic properties are investigated under different annealing conditions systematically with emphasis on the influence of oxygen pressure. Pure anatase structure was acquired for all the samples annealed at 450 ℃ for one hour. The samples annealed in air exhibit evident room-temperature ferromagnetism (RTFM) with a small magnetic moment of 0.029μB per Co atom and coercivity Hc of 26 Oe, while the samples annealed in vacuum have strong RTFM with a larger magnetic moment of 1.18 μB per Co atom and Hc of 430 Oe. The zero-field spin echo nuclear magnetic resonance spectrum of 59 Co is obtained to prove the existence of Co clusters in the latter samples, implying that the Co clusters are responsible for the strong RTFM in the samples annealed in vacuum. No Co cluster could be observed using both XPS and NMR techniques in the samples annealed in air, implying that the RTFM found in these samples is intrinsic.

  3. High-resolution nuclear magnetic resonance measurements in inhomogeneous magnetic fields: A fast two-dimensional J-resolved experiment.

    Science.gov (United States)

    Huang, Yuqing; Lin, Yung-Ya; Cai, Shuhui; Yang, Yu; Sun, Huijun; Lin, Yanqin; Chen, Zhong

    2016-03-14

    High spectral resolution in nuclear magnetic resonance (NMR) is a prerequisite for achieving accurate information relevant to molecular structures and composition assignments. The continuous development of superconducting magnets guarantees strong and homogeneous static magnetic fields for satisfactory spectral resolution. However, there exist circumstances, such as measurements on biological tissues and heterogeneous chemical samples, where the field homogeneity is degraded and spectral line broadening seems inevitable. Here we propose an NMR method, named intermolecular zero-quantum coherence J-resolved spectroscopy (iZQC-JRES), to face the challenge of field inhomogeneity and obtain desired high-resolution two-dimensional J-resolved spectra with fast acquisition. Theoretical analyses for this method are given according to the intermolecular multiple-quantum coherence treatment. Experiments on (a) a simple chemical solution and (b) an aqueous solution of mixed metabolites under externally deshimmed fields, and on (c) a table grape sample with intrinsic field inhomogeneity from magnetic susceptibility variations demonstrate the feasibility and applicability of the iZQC-JRES method. The application of this method to inhomogeneous chemical and biological samples, maybe in vivo samples, appears promising.

  4. Advances in high-resolution nuclear magnetic resonance methods in inhomogeneous magnetic fields using intermolecular multiple quantum coherences

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Strong and extremely homogeneous static magnetic field is usually required for high-resolution nu-clear magnetic resonance (NMR). However, in the cases of in vivo and so on, the magnetic field inho-mogeneity owing to magnetic susceptibility variation in samples is unavoidable and hard to eliminate by conventional methods such as shimming. Recently, intermolecular multiple quantum coherences (iMQCs) have been employed to eliminate inhomogeneous broadening and obtain high-resolution NMR spectra, especially for in vivo samples. Compared to other high-resolution NMR methods, iMQC method exhibits its unique feature and advantage. It simultaneously holds information of chemical shifts, multiplet structures, coupling constants, and relative peak areas. All the information is often used to analyze and characterize molecular structures in conventional one-dimensional NMR spec-troscopy. In this work, recent technical developments including our results in this field are summarized; the high-resolution mechanism is analyzed and comparison with other methods based on interactions between spins is made; comments on the current situation and outlook on the research directions are also made.

  5. Nuclear magnetic shielding constants of liquid water: Insights from hybrid quantum mechanics/molecular mechanics models

    Science.gov (United States)

    Kongsted, Jacob; Nielsen, Christian B.; Mikkelsen, Kurt V.; Christiansen, Ove; Ruud, Kenneth

    2007-01-01

    We present a gauge-origin independent method for the calculation of nuclear magnetic shielding tensors of molecules in a structured and polarizable environment. The method is based on a combination of density functional theory (DFT) or Hartree-Fock wave functions with molecular mechanics. The method is unique in the sense that it includes three important properties that need to be fulfilled in accurate calculations of nuclear magnetic shielding constants: (i) the model includes electron correlation effects, (ii) the model uses gauge-including atomic orbitals to give gauge-origin independent results, and (iii) the effect of the environment is treated self-consistently using a discrete reaction-field methodology. The authors present sample calculations of the isotropic nuclear magnetic shielding constants of liquid water based on a large number of solute-solvent configurations derived from molecular dynamics simulations employing potentials which treat solvent polarization either explicitly or implicitly. For both the O17 and H1 isotropic shielding constants the best predicted results compare fairly well with the experimental data, i.e., they reproduce the experimental solvent shifts to within 4ppm for the O17 shielding and 1ppm for the H1 shielding.

  6. (83)Kr nuclear magnetic moment in terms of that of (3)He.

    Science.gov (United States)

    Makulski, Włodzimierz

    2014-08-01

    High resolution NMR spectroscopy was applied to precisely determine the (83)Kr nuclear magnetic dipole moment on the basis of new results available for nuclear magnetic shielding in krypton and helium-3 atoms. Small amounts of (3)He as the solutes and (83)Kr as the buffer gas were observed in (3)He and (83)Kr NMR spectra at the constant external field, B0 = 11.7578 T. In each case, the resonance frequencies (ν(He) and ν(Kr)) were linearly dependent on the density of gaseous solvent. The extrapolation of experimental points to the zero density of gaseous krypton allowed for the evaluation of both resonance frequencies free from intermolecular interactions. By combining these measurements with the recommended (83)Kr chemical shielding value, the nuclear magnetic moment could be determined with much better precision than ever before, μ((83)Kr) = -0.9707297(32)μN, with the improvement due to the greater accuracy of the spectral data.

  7. NMR absolute shielding scale and nuclear magnetic dipole moment of (207)Pb.

    Science.gov (United States)

    Adrjan, Bożena; Makulski, Włodzimierz; Jackowski, Karol; Demissie, Taye B; Ruud, Kenneth; Antušek, Andrej; Jaszuński, Michał

    2016-06-28

    An absolute shielding scale is proposed for (207)Pb nuclear magnetic resonance (NMR) spectroscopy. It is based on ab initio calculations performed on an isolated tetramethyllead Pb(CH3)4 molecule and the assignment of the experimental resonance frequency from the gas-phase NMR spectra of Pb(CH3)4, extrapolated to zero density of the buffer gas to obtain the result for an isolated molecule. The computed (207)Pb shielding constant is 10 790 ppm for the isolated molecule, leading to a shielding of 10799.7 ppm for liquid Pb(CH3)4 which is the accepted reference standard for (207)Pb NMR spectra. The new experimental and theoretical data are used to determine μ((207)Pb), the nuclear magnetic dipole moment of (207)Pb, by applying the standard relationship between NMR frequencies, shielding constants and nuclear moments of two nuclei in the same external magnetic field. Using the gas-phase (207)Pb and (reference) proton results and the theoretical value of the Pb shielding in Pb(CH3)4, we find μ((207)Pb) = 0.59064 μN. The analysis of new experimental and theoretical data obtained for the Pb(2+) ion in water solutions provides similar values of μ((207)Pb), in the range of 0.59000-0.59131 μN.

  8. Nuclear magnetic biosignatures in the carbonaceous matter of ancient cherts: comparison with carbonaceous meteorites.

    Science.gov (United States)

    Gourier, Didier; Delpoux, Olivier; Binet, Laurent; Vezin, Hervé

    2013-10-01

    The search for organic biosignatures is motivated by the hope of understanding the conditions of emergence of life on Earth and the perspective of finding traces of extinct life in martian sediments. Paramagnetic radicals, which exist naturally in amorphous carbonaceous matter fossilized in Precambrian cherts, were used as local structural probes and studied by electron paramagnetic resonance (EPR) spectroscopy. The nuclear magnetic resonance transitions of elements inside and around these radicals were detected by monitoring the nuclear modulations of electron spin echo in pulsed EPR. We found that the carbonaceous matter of fossilized microorganisms with age up to 3.5 billion years gives specific nuclear magnetic signatures of hydrogen (¹H), carbon (¹³C), and phosphorus (³¹P) nuclei. We observed that these potential biosignatures of extinct life are found neither in the carbonaceous matter of carbonaceous meteorites (4.56 billion years), the most ancient objects of the Solar System, nor in any carbonaceous matter resulting from carbonization of organic and bioorganic precursors. These results indicate that these nuclear signatures are sensitive to thermal episodes and can be used for Archean cherts with metamorphism not higher than the greenschist facies.

  9. Bioengineered Magnetoferritin Nanoprobes for Single-Dose Nuclear-Magnetic Resonance Tumor Imaging.

    Science.gov (United States)

    Zhao, Yanzhao; Liang, Minmin; Li, Xiao; Fan, Kelong; Xiao, Jie; Li, Yanli; Shi, Hongcheng; Wang, Fei; Choi, Hak Soo; Cheng, Dengfeng; Yan, Xiyun

    2016-04-26

    Despite all the advances in multimodal imaging, it remains a significant challenge to acquire both magnetic resonance and nuclear imaging in a single dose because of the enormous difference in sensitivity. Indeed, nuclear imaging is almost 10(6)-fold more sensitive than magnetic resonance imaging (MRI); thus, repeated injections are generally required to obtain sufficient MR signals after nuclear imaging. Here, we show that strategically engineered magnetoferritin nanoprobes can image tumors with high sensitivity and specificity using SPECT and MRI in living mice after a single intravenous injection. The magnetoferritin nanoprobes composed of (125)I radionuclide-conjugated human H-ferritin iron nanocages ((125)I-M-HFn) internalize robustly into cancer cells via a novel tumor-specific HFn-TfR1 pathway. In particular, the endocytic recycling characteristic of TfR1 transporters solves the nuclear signal blocking issue caused by the high dose nanoprobes injected for MRI, thus enabling simultaneous functional and morphological tumor imaging without reliance on multi-injections.

  10. Bohr-Weisskopf effect influence of the distributed nuclear magnetization on hfs

    CERN Document Server

    Stroke, Hinko Henry; Pinard, J

    2000-01-01

    Nuclear magnetic moments provide a sensitive test of nuclear wave functions, in particular those of neutrons, which are not readily obtainable from other nuclear data. These are taking added importance by recent proposals to study parity non-conservation (PNC) effects in alkali atoms in isotopic series. By taking ratios of the PNC effects in pairs of isotopes, uncertainties in the atomic wave functions are largely cancelled out at the cost of knowledge of the change in the neutron wave function, the Bohr-Weisskopf effect (1950) in the hyperfine structure interaction of atoms measures the influence of the spatial distribution of the nuclear magnetization, and thereby provides an additional constraint on the determination of the neutron wave function. The added great importance of B-W in the determination of QED effects from the hfs in hydrogen-like ions of heavy elements, as measured recently at GSI, is noted, the B-W experiments require precision measurements of the hfs interactions and, independently, of the...

  11. Enhanced affinity of ketotifen toward tamarind seed polysaccharide in comparison with hydroxyethylcellulose and hyaluronic acid: a nuclear magnetic resonance investigation.

    Science.gov (United States)

    Uccello-Barretta, Gloria; Nazzi, Samuele; Balzano, Federica; Di Colo, Giacomo; Zambito, Ylenia; Zaino, Chiara; Sansò, Marco; Salvadori, Eleonora; Benvenuti, Marco

    2008-08-01

    Nuclear magnetic resonance (NMR) spectroscopy demonstrated that, in aqueous solution, ketotifen fumarate bound more strongly to tamarind seed polysaccharide (TSP) than to hydroxyethylcellulose or hyaluronic acid. Results were confirmed by dynamic dialysis technique.

  12. Application of nuclear magnetic resonance in osteoporosis evaluation; Aplicacoes de ressonancia magnetica nuclear na avaliacao de osteoporose

    Energy Technology Data Exchange (ETDEWEB)

    Giannoni, Ricardo A., E-mail: giannoni@ird.gov.br [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Montrazi, Elton T.; Bonagamba, Tito J., E-mail: elton.montrazi@gmail.com, E-mail: tito@ifsc.usp.br [Universidade de Sao Paulo (IFSC/USP), Sao Carlos, SP (Brazil). Inst. de Fisica; Cesar, Reinaldo, E-mail: reinaldofisica@gmail.com [Universidade de Sao Paulo (EESC/USP), Sao Carlos, SP (Brazil). Escola de Engenharia

    2013-07-01

    In this work, initially ceramic samples of known porosity were used. These ceramic samples were saturated with water. The nuclear magnetic resonance signal due to relaxation processes that the hydrogen nucleus water contained in the pores of this ceramic material was measured. Then these samples were subjected to a process of drying and measures successively. As the water contained in pores greater evaporates the intensity of signal decreases and shows the sign because of the smaller pores. The analysis of this drying process gives a qualitative assessment of the pore size of the material. In a second step, bones of animals of unknown porosity underwent the same methodology for evaluating osteoporosis. Also a sample of human vertebra in a unique manner, with the same purpose was measured. Combined with other techniques is a quantitative evaluation of the possible porosity.

  13. Nuclear magnetic relaxation induced by exchange-mediated orientational randomization: Longitudinal relaxation dispersion for a dipole-coupled spin-1/2 pair

    Science.gov (United States)

    Chang, Zhiwei; Halle, Bertil

    2013-10-01

    In complex biological or colloidal samples, magnetic relaxation dispersion (MRD) experiments using the field-cycling technique can characterize molecular motions on time scales ranging from nanoseconds to microseconds, provided that a rigorous theory of nuclear spin relaxation is available. In gels, cross-linked proteins, and biological tissues, where an immobilized macromolecular component coexists with a mobile solvent phase, nuclear spins residing in solvent (or cosolvent) species relax predominantly via exchange-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings. The physical or chemical exchange processes that dominate the MRD typically occur on a time scale of microseconds or longer, where the conventional perturbation theory of spin relaxation breaks down. There is thus a need for a more general relaxation theory. Such a theory, based on the stochastic Liouville equation (SLE) for the EMOR mechanism, is available for a single quadrupolar spin I = 1. Here, we present the corresponding theory for a dipole-coupled spin-1/2 pair. To our knowledge, this is the first treatment of dipolar MRD outside the motional-narrowing regime. Based on an analytical solution of the spatial part of the SLE, we show how the integral longitudinal relaxation rate can be computed efficiently. Both like and unlike spins, with selective or non-selective excitation, are treated. For the experimentally important dilute regime, where only a small fraction of the spin pairs are immobilized, we obtain simple analytical expressions for the auto-relaxation and cross-relaxation rates which generalize the well-known Solomon equations. These generalized results will be useful in biophysical studies, e.g., of intermittent protein dynamics. In addition, they represent a first step towards a rigorous theory of water 1H relaxation in biological tissues, which is a prerequisite for unravelling the molecular basis of soft

  14. Low-field nuclear magnetic resonance for the in vivo study of water content in trees

    Energy Technology Data Exchange (ETDEWEB)

    Yoder, Jacob, E-mail: jlyoder@lanl.gov [Inorganic, Isotope and Actinide Chemistry, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Malone, Michael W.; Espy, Michelle A. [Applied Modern Physics, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Sevanto, Sanna [Earth Systems Observations, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-09-15

    Nuclear magnetic resonance (NMR) and magnetic resonance imaging have long been used to study water content in plants. Approaches have been primarily based on systems using large magnetic fields (∼1 T) to obtain NMR signals with good signal-to-noise. This is because the NMR signal scales approximately with the magnetic field strength squared. However, there are also limits to this approach in terms of realistic physiological configuration or those imposed by the size and cost of the magnet. Here we have taken a different approach – keeping the magnetic field low to produce a very light and inexpensive system, suitable for bulk water measurements on trees less than 5 cm in diameter, which could easily be duplicated to measure on many trees or from multiple parts of the same tree. Using this system we have shown sensitivity to water content in trees and their cuttings and observed a diurnal signal variation in tree water content in a greenhouse. We also demonstrate that, with calibration and modeling of the thermal polarization, the system is reliable under significant temperature variation.

  15. Nuclear relaxation in an electric field enables the determination of isotropic magnetic shielding

    Science.gov (United States)

    Garbacz, Piotr

    2016-08-01

    It is shown that in contrast to the case of nuclear relaxation in a magnetic field B, simultaneous application of the magnetic field B and an additional electric field E causes transverse relaxation of a spin-1/2 nucleus with the rate proportional to the square of the isotropic part of the magnetic shielding tensor. This effect can contribute noticeably to the transverse relaxation rate of heavy nuclei in molecules that possess permanent electric dipole moments. Relativistic quantum mechanical computations indicate that for 205Tl nucleus in a Pt-Tl bonded complex, Pt(CN)5Tl, the transverse relaxation rate induced by the electric field is of the order of 1 s-1 at E = 5 kV/mm and B = 10 T.

  16. A Neutron Diffraction Study of the Nuclear and Magnetic Structure of MnNb2O6

    DEFF Research Database (Denmark)

    Nielsen, Oliver Vindex; Lebech, Bente; Krebs Larsen, F.;

    1976-01-01

    A neutron diffraction study was made of the nuclear and the magnetic structure of MnNb2O6 single crystals. The thirteen nuclear parameters (space group Pbcn) were determined from 304 reflections at room temperature. The antiferromagnetic structure (Neel temperature=4.4K), determined at 1.2K, is a...

  17. [Recent progress in nuclear magnetic resonance spectrum for drug research and development].

    Science.gov (United States)

    Zhong, Jun; Jiang, Xue-mei

    2015-01-01

    In the process of modern drug research, the new methods and technologies which can detect drug molecules' chemical composition, structure and interaction with biomolecules are always the key scientific problems people care about. Spectra (including IR, UV and NMR) are the most common analytical methods, of which NMR can obtain detailed parameter about the nucleus of organic molecules through researching the laws of nuclear transition in the impact of surrounding chemical environment. The parameter contains rich information about the chemical composition, structure and interaction with other molecules of organic molecules. In many complex environments, such as liquid, solid or gas state, even biological in situ environment, NMR can provide molecules' chemical composition, atomic-resolution three-dimensional structure, information of interaction with each other and dynamic process, especially the information about drug interacting with biomacromolecules. In recent years, the applications of nuclear magnetic resonance spectrum in drug research and development are more and more widespread. This paper reviewed its recent progress in structure and dynamic of targeted biological macromolecules, drug design and screening and drug metabolism in drug research and development. In the first part, we gave a brief introduction of nuclear magnetic resonance technology and its applications in drug research. In the second part, we explained the basic principles briefly and summarized progress in methods and techniques for drug research. In the third part, we discussed applications of nuclear magnetic resonance ir structure and dynamic of targeted biological macromolecules, drug design and screening and drug metabolism in detail. The conclusions were stated in the last part.

  18. Direct current superconducting quantum interference device spectrometer for pulsed nuclear magnetic resonance and nuclear quadrupole resonance at frequencies up to 5 MHz

    Science.gov (United States)

    TonThat, Dinh M.; Clarke, John

    1996-08-01

    A spectrometer based on a dc superconducting quantum interference device (SQUID) has been developed for the direct detection of nuclear magnetic resonance (NMR) or nuclear quadrupole resonance (NQR) at frequencies up to 5 MHz. The sample is coupled to the input coil of the niobium-based SQUID via a nonresonant superconducting circuit. The flux locked loop involves the direct offset integration technique with additional positive feedback in which the output of the SQUID is coupled directly to a low-noise preamplifier. Precession of the nuclear quadrupole spins is induced by a magnetic field pulse with the feedback circuit disabled; subsequently, flux locked operation is restored and the SQUID amplifies the signal produced by the nuclear free induction signal. The spectrometer has been used to detect 27Al NQR signals in ruby (Al2O3[Cr3+]) at 359 and 714 kHz.

  19. Homometallic and Heterometallic Antiferromagnetic Rings: Magnetic Properties Studied by Nuclear Magnetic Resonance

    Energy Technology Data Exchange (ETDEWEB)

    Casadei, Cecilia [Univ. of Pavia (Italy)

    2011-01-01

    The aim of the present thesis is to investigate the local magnetic properties of homometallic Cr8 antiferromagnetic (AFM) ring and the changes occurring by replacing one Cr3+ ion with diamagnetic Cd2+ (Cr7Cd) and with Ni2+ (Cr7Ni). In the heterometallic ring a redistribution of the local magnetic moment is expected in the low temperature ground state. We have investigated those changes by both 53Cr-NMR and 19F-NMR. We have determined the order of magnitude of the transferred hyperfine coupling constant 19F - M+ where M+ = Cr3+, Ni2+ in the different rings. This latter result gives useful information about the overlapping of the electronic wavefunctions involved in the coordinative bond.

  20. High-resolution liquid- and solid-state nuclear magnetic resonance of nanoliter sample volumes using microcoil detectors

    NARCIS (Netherlands)

    Kentgens, A.P.M.; Bart, J.; Bentum, van P.J.M.; Brinkmann, A.; Eck, van E.R.H.; Gardeniers, J.G.E.; Janssen, J.W.G.; Knijn, P.J.; Vasa, S.; Verkuijlen, M.H.W.

    2008-01-01

    The predominant means to detect nuclear magnetic resonance(NMR) is to monitor the voltage induced in a radiofrequency coil by the precessing magnetization. To address the sensitivity of NMR for mass-limited samples it is worthwhile to miniaturize this detector coil. Although making smaller coils see

  1. Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Jeffry Todd

    2004-12-21

    Experimental and theoretical research conducted in two areas in the field of nuclear magnetic resonance (NMR) spectroscopy is presented: (1) studies of the coherent quantum-mechanical control of the angular momentum dynamics of quadrupolar (spin I > 1/2) nuclei and its application to the determination of molecular structure; and (2) applications of the long-range nuclear dipolar field to novel NMR detection methodologies.The dissertation is organized into six chapters. The first two chapters and associated appendices are intended to be pedagogical and include an introduction to the quantum mechanical theory of pulsed NMR spectroscopy and the time dependent theory of quantum mechanics. The third chapter describes investigations of the solid-state multiple-quantum magic angle spinning (MQMAS) NMR experiment applied to I = 5/2 quadrupolar nuclei. This work reports the use of rotary resonance-matched radiofrequency irradiation for sensitivity enhancement of the I = 5/2 MQMAS experiment. These experiments exhibited certain selective line narrowing effects which were investigated theoretically.The fourth chapter extends the discussion of multiple quantum spectroscopy of quadrupolar nuclei to a mostly theoretical study of the feasibility of enhancing the resolution of nitrogen-14 NMR of large biomolecules in solution via double-quantum spectroscopy. The fifth chapter continues to extend the principles of multiple quantum NMR spectroscopy of quadrupolar nuclei to make analogies between experiments in NMR/nuclear quadrupolar resonance (NQR) and experiments in atomic/molecular optics (AMO). These analogies are made through the Hamiltonian and density operator formalism of angular momentum dynamics in the presence of electric and magnetic fields.The sixth chapter investigates the use of the macroscopic nuclear dipolar field to encode the NMR spectrum of an analyte nucleus indirectly in the magnetization of a sensor nucleus. This technique could potentially serve as an

  2. Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Jeffry Todd [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    Experimental and theoretical research conducted in two areas in the field of nuclear magnetic resonance (NMR) spectroscopy is presented: (1) studies of the coherent quantum-mechanical control of the angular momentum dynamics of quadrupolar (spin I > 1/2) nuclei and its application to the determination of molecular structure; and (2) applications of the long-range nuclear dipolar field to novel NMR detection methodologies.The dissertation is organized into six chapters. The first two chapters and associated appendices are intended to be pedagogical and include an introduction to the quantum mechanical theory of pulsed NMR spectroscopy and the time dependent theory of quantum mechanics. The third chapter describes investigations of the solid-state multiple-quantum magic angle spinning (MQMAS) NMR experiment applied to I = 5/2 quadrupolar nuclei. This work reports the use of rotary resonance-matched radiofrequency irradiation for sensitivity enhancement of the I = 5/2 MQMAS experiment. These experiments exhibited certain selective line narrowing effects which were investigated theoretically.The fourth chapter extends the discussion of multiple quantum spectroscopy of quadrupolar nuclei to a mostly theoretical study of the feasibility of enhancing the resolution of nitrogen-14 NMR of large biomolecules in solution via double-quantum spectroscopy. The fifth chapter continues to extend the principles of multiple quantum NMR spectroscopy of quadrupolar nuclei to make analogies between experiments in NMR/nuclear quadrupolar resonance (NQR) and experiments in atomic/molecular optics (AMO). These analogies are made through the Hamiltonian and density operator formalism of angular momentum dynamics in the presence of electric and magnetic fields.The sixth chapter investigates the use of the macroscopic nuclear dipolar field to encode the NMR spectrum of an analyte nucleus indirectly in the magnetization of a sensor nucleus. This technique could potentially serve as an

  3. Modeling the nuclear magnetic resonance behavior of lung: from electrical engineering to critical care medicine.

    Science.gov (United States)

    Cutillo, A G; Ailion, D C

    1999-01-01

    The present article reviews the basic principles of a new approach to the characterization of pulmonary disease. This approach is based on the unique nuclear magnetic resonance (NMR) properties of the lung and combines experimental measurements (using specially developed NMR techniques) with theoretical simulations. The NMR signal from inflated lungs decays very rapidly compared with the signal from completely collapsed (airless) lungs. This phenomenon is due to the presence of internal magnetic field inhomogeneity produced by the alveolar air-tissue interface (because air and water have different magnetic susceptibilities). The air-tissue interface effects can be detected and quantified by magnetic resonance imaging (MRI) techniques using temporally symmetric and asymmetric spin-echo sequences. Theoretical models developed to explain the internal (tissue-induced) magnetic field inhomogeneity in aerated lungs predict the NMR lung behavior as a function of various technical and physiological factors (e.g., the level of lung inflation) and simulate the effects of various lung disorders (in particular, pulmonary edema) on this behavior. Good agreement has been observed between the predictions obtained from the mathematical models and the results of experimental NMR measurements in normal and diseased lungs. Our theoretical and experimental data have important pathophysiological and clinical implications, especially with respect to the characterization of acute lung disease (e.g., pulmonary edema) and the management of critically ill patients.

  4. Nuclear moments

    CERN Document Server

    Kopferman, H; Massey, H S W

    1958-01-01

    Nuclear Moments focuses on the processes, methodologies, reactions, and transformations of molecules and atoms, including magnetic resonance and nuclear moments. The book first offers information on nuclear moments in free atoms and molecules, including theoretical foundations of hyperfine structure, isotope shift, spectra of diatomic molecules, and vector model of molecules. The manuscript then takes a look at nuclear moments in liquids and crystals. Discussions focus on nuclear paramagnetic and magnetic resonance and nuclear quadrupole resonance. The text discusses nuclear moments and nucl

  5. Selection of Annonaceae Species for the Control of Spodoptera frugiperda (Lepidoptera: Noctuidae) and Metabolic Profiling of Duguetia lanceolata Using Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Alves, D S; Machado, A R T; Campos, V A C; Oliveira, D F; Carvalho, G A

    2016-04-01

    This study was performed to investigate the activity of 19 dichloromethane-soluble fractions obtained from the methanolic extracts of 10 Annonaceae species against the fall armyworm, Spodoptera frugiperda (J. E. Smith). The stem bark of Duguetia lanceolata A. St.-Hil. showed the highest insecticidal activity, with a median lethal time (LT50) of 61.4 h and a median lethal concentration (LC50) of 946.5 µg/ml of diet. The dichloromethane-soluble fractions from six D. lanceolata specimens were subjected to evaluation of their activities against S. frugiperda and metabolomic analysis using hydrogen (1H) nuclear magnetic resonance (NMR) spectroscopy. Although all of the samples affected S. frugiperda mortality, their insecticidal activities varied according to the sample used in the experiments. Using partial least squares regression of the results, the D. lanceolata specimens were grouped according to their metabolite profile and insecticidal activity. A detailed analysis via uni- and bidimensional NMR spectroscopy showed that the peaks in the 1H NMR spectra associated with increased insecticidal activity could be attributed to 2,4,5-trimethoxystyrene, which suggests that this substance is involved in the insecticidal activity of the stem bark fraction of D. lanceolata.

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

    Science.gov (United States)

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

    2014-12-01

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

  7. Nonionic homopolymeric amphipols: application to membrane protein folding, cell-free synthesis, and solution nuclear magnetic resonance.

    Science.gov (United States)

    Bazzacco, Paola; Billon-Denis, Emmanuelle; Sharma, K Shivaji; Catoire, Laurent J; Mary, Sophie; Le Bon, Christel; Point, Elodie; Banères, Jean-Louis; Durand, Grégory; Zito, Francesca; Pucci, Bernard; Popot, Jean-Luc

    2012-02-21

    Nonionic amphipols (NAPols) synthesized by homotelomerization of an amphiphatic monomer are able to keep membrane proteins (MPs) stable and functional in the absence of detergent. Some of their biochemical and biophysical properties and applications have been examined, with particular attention being paid to their complementarity with the classical polyacrylate-based amphipol A8-35. Bacteriorhodopsin (BR) from Halobacterium salinarum and the cytochrome b(6)f complex from Chlamydomonas reinhardtii were found to be in their native state and highly stable following complexation with NAPols. NAPol-trapped BR was shown to undergo its complete photocycle. Because of the pH insensitivity of NAPols, solution nuclear magnetic resonance (NMR) two-dimensional (1)H-(15)N heteronuclear single-quantum coherence spectra of NAPol-trapped outer MP X from Escherichia coli (OmpX) could be recorded at pH 6.8. They present a resolution similar to that of the spectra of OmpX/A8-35 complexes recorded at pH 8.0 and give access to signals from solvent-exposed rapidy exchanging amide protons. Like A8-35, NAPols can be used to fold MPs to their native state as demonstrated here with BR and with the ghrelin G protein-coupled receptor GHS-R1a, thus extending the range of accessible folding conditions. Following NAPol-assisted folding, GHS-R1a bound four of its specific ligands, recruited arrestin-2, and activated binding of GTPγS by the G(αq) protein. Finally, cell-free synthesis of MPs, which is inhibited by A8-35 and sulfonated amphipols, was found to be very efficient in the presence of NAPols. These results open broad new perspectives on the use of amphipols for MP studies.

  8. Time-Reversal Symmetry Violation in Molecules Induced by Nuclear Magnetic Quadrupole Moments

    Science.gov (United States)

    Flambaum, V. V.; DeMille, D.; Kozlov, M. G.

    2014-09-01

    Recent measurements in paramagnetic molecules improved the limit on the electron electric dipole moment (EDM) by an order of magnitude. Time-reversal (T) and parity (P) symmetry violation in molecules may also come from their nuclei. We point out that nuclear T, P-odd effects are amplified in paramagnetic molecules containing deformed nuclei, where the primary effects arise from the T, P-odd nuclear magnetic quadrupole moment (MQM). We perform calculations of T, P-odd effects in the molecules TaN, ThO, ThF+, HfF+, YbF, HgF, and BaF induced by MQMs. We compare our results with those for the diamagnetic TlF molecule, where the T, P-odd effects are produced by the nuclear Schiff moment. We argue that measurements in molecules with MQMs may provide improved limits on the strength of T, P-odd nuclear forces, on the proton, neutron, and quark EDMs, on quark chromo-EDMs, and on the QCD θ term and CP-violating quark interactions.

  9. Billion-Fold Enhancement in Sensitivity of Nuclear Magnetic Resonance Spectroscopy for Magnesium Ions in Solution

    CERN Document Server

    Gottberg, Alexander; Kowalska, Magdalena; Bissell, Mark L; Arcisauskaite, Vaida; Blaum, Klaus; Helmke, Alexander; Johnston, Karl; Kreim, Kim; Larsen, Flemming H; Neugart, Rainer; Neyens, Gerda; Garcia Ruiz, Ronald F; Szunyogh, Daniel; Thulstrup, Peter W; Yordanov, Deyan T; Hemmingsen, Lars

    2014-01-01

    β-nuclear magnetic resonance (NMR) spectroscopy is highly sensitive compared to conventional NMR spectroscopy, and may be applied for several elements across the periodic table. β-NMR has previously been successfully applied in the fields of nuclear and solid-state physics. In this work, β-NMR is applied, for the first time, to record an NMR spectrum for a species in solution. 31Mg β-NMR spectra are measured for as few as 107 magnesium ions in ionic liquid (EMIM-Ac) within minutes, as a prototypical test case. Resonances are observed at 3882.9 and 3887.2 kHz in an external field of 0.3 T. The key achievement of the current work is to demonstrate that β-NMR is applicable for the analysis of species in solution, and thus represents a novel spectroscopic technique for use in general chemistry and potentially in biochemistry.

  10. high resolution nuclear magnetic resonance spectroscopy in studies of Picrotoxanolides of Coriaria. Coryamyrtin

    Directory of Open Access Journals (Sweden)

    Aguirre Galvis Luis Enrique

    1987-06-01

    Full Text Available Spectral evidence by Protonic Nuclear Magnetic Resonance (400
    MAHz and 90 MHz of the analeptic sesquiterpene lactone coriamyrtin, isolated from the colombian plant Coriaria microphyUn, Poir., is discussed, and analogies are made with the spectra of authentic samples of picrotin and picrotoxinin.Se discute la evidencia espectroscópica de Resonancia Magnética
    Nuclear Protónica (400MHz y 90 MHz para coriamirtina, una lactona sesquiterpénica de carácter analéptico, aislada de la planta colombiana Coriasia microphyUn, Poir., mediante analogías con espectros de muestras autenticadas de picrotina y picrotoxinina.

  11. Antisymmetric Couplings Enable Direct Observation of Chirality in Nuclear Magnetic Resonance Spectroscopy

    CERN Document Server

    King, Jonathan P; Blanchard, John W

    2016-01-01

    Here we demonstrate that a term in the nuclear spin Hamiltonian, the antisymmetric \\textit{J}-coupling, is fundamentally connected to molecular chirality. We propose and simulate a nuclear magnetic resonance (NMR) experiment to observe this interaction and differentiate between enantiomers without adding any additional chiral agent to the sample. The antisymmetric \\textit{J}-coupling may be observed in the presence of molecular orientation by an external electric field. The opposite parity of the antisymmetric coupling tensor and the molecular electric dipole moment yields a sign change of the observed coupling between enantiomers. We show how this sign change influences the phase of the NMR spectrum and may be used to discriminate between enantiomers.

  12. Billion-fold enhancement in sensitivity of nuclear magnetic resonance spectroscopy for magnesium ions in solution.

    Science.gov (United States)

    Gottberg, Alexander; Stachura, Monika; Kowalska, Magdalena; Bissell, Mark L; Arcisauskaite, Vaida; Blaum, Klaus; Helmke, Alexander; Johnston, Karl; Kreim, Kim; Larsen, Flemming H; Neugart, Rainer; Neyens, Gerda; Garcia Ruiz, Ronald F; Szunyogh, Daniel; Thulstrup, Peter W; Yordanov, Deyan T; Hemmingsen, Lars

    2014-12-15

    β-nuclear magnetic resonance (NMR) spectroscopy is highly sensitive compared to conventional NMR spectroscopy, and may be applied for several elements across the periodic table. β-NMR has previously been successfully applied in the fields of nuclear and solid-state physics. In this work, β-NMR is applied, for the first time, to record an NMR spectrum for a species in solution. (31)Mg β-NMR spectra are measured for as few as 10(7) magnesium ions in ionic liquid (EMIM-Ac) within minutes, as a prototypical test case. Resonances are observed at 3882.9 and 3887.2 kHz in an external field of 0.3 T. The key achievement of the current work is to demonstrate that β-NMR is applicable for the analysis of species in solution, and thus represents a novel spectroscopic technique for use in general chemistry and potentially in biochemistry.

  13. Metabolite profiling of Clinacanthus nutans leaves extracts obtained from different drying methods by 1H NMR-based metabolomics

    Science.gov (United States)

    Hashim, Noor Haslinda Noor; Latip, Jalifah; Khatib, Alfi

    2016-11-01

    The metabolites of Clinacanthus nutans leaves extracts and their dependence on drying process were systematically characterized using 1H nuclear magnetic resonance spectroscopy (NMR) multivariate data analysis. Principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA) were able to distinguish the leaves extracts obtained from different drying methods. The identified metabolites were carbohydrates, amino acid, flavonoids and sulfur glucoside compounds. The major metabolites responsible for the separation in PLS-DA loading plots were lupeol, cycloclinacosides, betulin, cerebrosides and choline. The results showed that the combination of 1H NMR spectroscopy and multivariate data analyses could act as an efficient technique to understand the C. nutans composition and its variation.

  14. Partial-Homogeneity-Based Two-Dimensional High-Resolution Nuclear Magnetic Resonance Spectroscopy under Inhomogeneous Magnetic Fields.

    Science.gov (United States)

    Qiu, Wenqi; Wei, Zhiliang; Ding, Nan; Yang, Yu; Ye, Qimiao; Lin, Yulan; Chen, Zhong

    2016-05-18

    High-resolution multidimensional nuclear magnetic resonance (NMR) spectroscopy serves as an irreplaceable and versatile tool in various chemical investigations. In this study, a method based on the concept of partial homogeneity is developed to offer two-dimensional (2D) high-resolution NMR spectra under inhomogeneous fields. Oscillating gradients are exerted to encode the high-resolution information, and a field-inhomogeneity correction algorithm based on pattern recognition is designed to recover high-resolution spectra. Under fields where inhomogeneity primarily distributes along a single orientation, the proposed method will improve performances of 2D NMR spectroscopy without increasing the experimental duration or significant loss in sensitivity, and thus may open important perspectives for studies of inhomogeneous chemical systems.

  15. Recent Advances in Computational Methods for Nuclear Magnetic Resonance Data Processing

    KAUST Repository

    Gao, Xin

    2013-01-11

    Although three-dimensional protein structure determination using nuclear magnetic resonance (NMR) spectroscopy is a computationally costly and tedious process that would benefit from advanced computational techniques, it has not garnered much research attention from specialists in bioinformatics and computational biology. In this paper, we review recent advances in computational methods for NMR protein structure determination. We summarize the advantages of and bottlenecks in the existing methods and outline some open problems in the field. We also discuss current trends in NMR technology development and suggest directions for research on future computational methods for NMR.

  16. Implementation of a multiple round quantum dense coding using nuclear magnetic resonance

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Jingfu; XIE; Jingyi; WANG; Chuan; DENG; Zhiwei; LU

    2005-01-01

    A multiple round quantum dense coding scheme based on the quantum phase estimation algorithm is proposed and implemented in a three qubit nuclear magnetic resonance (NMR) quantum computer. Using an m + 1 qubit system, Bob can transmit one of 2m+1 messages to Alice, through manipulating only one qubit and exchanging it between Alice and Bob for m rounds. The information capacity is enhanced to m + 1 bits as compared to m bits in a classical scheme. The scheme has been demonstrated in NMR system, and the experimental results show a good agreement between theory and experiment.

  17. Molecular Structure Laboratory. Fourier Transform Nuclear Magnetic Resonance (FTNMR) Spectrometer and Ancillary Instrumentation at SUNY Geneseo

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, David K [State Univ. of New York (SUNY), Geneseo, NY (United States)

    2015-12-31

    An Agilent 400-MR nuclear magnetic resonance (NMR) spectrometer and ancillary equipment were purchased, which are being used for molecular structure elucidation.  The instrumentation is housed in a pre-existing facility designed specifically for its use. This instrument package is being used to expand the research and educational efforts of the faculty and students at SUNY-Geneseo and is made available to neighboring educational institutions and business concerns.  Funds were also used for training of College personnel, maintenance of the instrumentation, and installation of the equipment.

  18. Isotropic proton-detected local-field nuclear magnetic resonancein solids

    Energy Technology Data Exchange (ETDEWEB)

    Havlin, Robert H.; Walls, Jamie D.; Pines, Alexander

    2004-08-04

    A new nuclear magnetic resonance (NMR) method is presented which produces linear, isotropic proton-detected local-field spectra for InS spin systems in powdered samples. The method, HETeronuclear Isotropic Evolution (HETIE), refocuses the anisotropic portion of the heteronuclear dipolar coupling frequencies by evolving the system under a series of specially designed Hamiltonians and evolution pathways. The theory behind HETIE is represented along with experimental studies conducted on a powdered sample of ferrocene, demonstrating the methodology outlined in this paper. Applications of HETIE for structural determination in solid-state NMR are discussed.

  19. Combining Nuclear Magnetic Resonance Spectroscopy and Density Functional Theory Calculations to Characterize Carvedilol Polymorphs.

    Science.gov (United States)

    Rezende, Carlos A; San Gil, Rosane A S; Borré, Leandro B; Pires, José Ricardo; Vaiss, Viviane S; Resende, Jackson A L C; Leitão, Alexandre A; De Alencastro, Ricardo B; Leal, Katia Z

    2016-09-01

    The experiments of carvedilol form II, form III, and hydrate by (13)C and (15)N cross-polarization magic-angle spinning (CP MAS) are reported. The GIPAW (gauge-including projector-augmented wave) method from DFT (density functional theory) calculations was used to simulate (13)C and (15)N chemical shifts. A very good agreement was found for the comparison between the global results of experimental and calculated nuclear magnetic resonance (NMR) chemical shifts for carvedilol polymorphs. This work aims a comprehensive understanding of carvedilol crystalline forms employing solution and solid-state NMR as well as DFT calculations.

  20. Experimental study of quantum simulation for quantum chemistry with a nuclear magnetic resonance simulator.

    Science.gov (United States)

    Lu, Dawei; Xu, Nanyang; Xu, Boruo; Li, Zhaokai; Chen, Hongwei; Peng, Xinhua; Xu, Ruixue; Du, Jiangfeng

    2012-10-13

    Quantum computers have been proved to be able to mimic quantum systems efficiently in polynomial time. Quantum chemistry problems, such as static molecular energy calculations and dynamical chemical reaction simulations, become very intractable on classical computers with scaling up of the system. Therefore, quantum simulation is a feasible and effective approach to tackle quantum chemistry problems. Proof-of-principle experiments have been implemented on the calculation of the hydrogen molecular energies and one-dimensional chemical isomerization reaction dynamics using nuclear magnetic resonance systems. We conclude that quantum simulation will surpass classical computers for quantum chemistry in the near future.

  1. Development of Nuclear Magnetic Resonance Imaging/spectroscopy for improved petroleum recovery. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barrufet, M.A.; Flumerfelt, F.W.; Walsh, M.P.; Watson, A.T.

    1994-04-01

    The overall objectives of this program are to develop and apply Nuclear Magnetic Resonance Imaging (NMRI) and CT X-Ray Scanning methods for determining rock, fluid, and petrophysical properties and for fundamental studies of multiphase flow behavior in porous media. Specific objectives are divided into four subtasks: (1) development of NMRI and CT scanning for the determination of rock-fluid and petrophysical properties; (2) development of NMRI and CT scanning for characterizing conventional multiphase displacement processes; (3) development of NMR and CT scanning for characterizing dispersed phase processes; and (4) miscible displacement studies.

  2. Geometric optimal control of the contrast imaging problem in Nuclear Magnetic Resonance

    CERN Document Server

    Bonnard, B; Glaser, S J; Lapert, M; Sugny, D; Zhang, Y

    2012-01-01

    The objective of this article is to introduce the tools to analyze the contrast imaging problem in Nuclear Magnetic Resonance. Optimal trajectories can be selected among extremal solutions of the Pontryagin Maximum Principle applied to this Mayer type optimal problem. Such trajectories are associated to the question of extremizing the transfer time. Hence the optimal problem is reduced to the analysis of the Hamiltonian dynamics related to singular extremals and their optimality status. This is illustrated by using the examples of cerebrospinal fluid / water and grey / white matter of cerebrum.

  3. Differentiation in vitro of inflammatory from non inflammatory synovial fluid by nuclear magnetic relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Teyssier, R.; Teyssier, M.; Colson, F.

    1987-01-01

    The differentiation between inflammatory and non inflammatory states has been performed using Nuclear Magnetic Resonance (NMR) in vitro by measuring relaxation times T/sub 1/ and T/sub 2/ in 84 synovials fluids obtained from various rheumatologic diseases. The results show that the T/sub 1//T/sub 2/ ratio is more sensitive to distinguish these two situations rather than the isolated T/sub 1/ or T/sub /2 values. In particular, high values of T/sub 1//T/sub 2/ ratio are found in septic arthritis.

  4. A Magnetic Carbon Sorbent for Radioactive Material from the Fukushima Nuclear Accident

    Science.gov (United States)

    Yamaguchi, Daizo; Furukawa, Kazumi; Takasuga, Masaya; Watanabe, Koki

    2014-08-01

    Here we present the first report of a carbon-γ-Fe2O3 nanoparticle composite of mesoporous carbon, bearing COOH- and phenolic OH- functional groups on its surface, a remarkable and magnetically separable adsorbent, for the radioactive material emitted by the Fukushima Daiichi nuclear power plant accident. Contaminated water and soil at a level of 1,739 Bq kg-1 (134Cs and 137Cs at 509 Bq kg-1 and 1,230 Bq kg-1, respectively) and 114,000 Bq kg-1 (134Cs and 137Cs at 38,700 Bq kg-1 and 75,300 Bq kg-1, respectively) were decontaminated by 99% and 90% respectively with just one treatment carried out in Nihonmatsu city in Fukushima. Since this material is remarkably high performance, magnetically separable, and a readily applicable technology, it would reduce the environmental impact of the Fukushima accident if it were used.

  5. [sup 27]Al nuclear magnetic resonance spectra in CeAl[sub 3] at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Hunziker, J. (Lab. fuer Festkoerperphysik, ETH-Hoenggerberg, Zuerich (Switzerland)); Gavilano, J.L. (Lab. fuer Festkoerperphysik, ETH-Hoenggerberg, Zuerich (Switzerland)); Buechi, S. (Lab. fuer Festkoerperphysik, ETH-Hoenggerberg, Zuerich (Switzerland)); Ott, H.R. (Lab. fuer Festkoerperphysik, ETH-Hoenggerberg, Zuerich (Switzerland))

    1994-02-01

    We have measured the nuclear magnetic resonance, NMR, spectra of CeAl[sub 3] at 3.964 MHz, 2.095 MHz and 0.937 MHz in the temperature range between 0.04 K and 20 K. The complicated NMR absorption line of CeAl[sub 3] powder is shown to have more than one component, corresponding to at least two inequivalent Al sites. Below 0.9 K the relative intensity of a broad asymmetric structure increases, and the width of the NMR spectrum shows a rapid increase. At fields of the order of two kilogauss the asymmetry is strongly supressed. The temperature dependence of the asymmetry and width of the spectrum below 0.9 K, can neither be explained in terms of a temperature dependent Knight shift nor in terms of conventional magnetic ordering. (orig.)

  6. Sub-nanoliter nuclear magnetic resonance coils fabricated with multilayer soft lithography

    Science.gov (United States)

    Lam, Matthew H. C.; Homenuke, Mark A.; Michal, Carl A.; Hansen, Carl L.

    2009-09-01

    We describe the fabrication and characterization of sub-nanoliter volume nuclear magnetic resonance (NMR) transceiver coils that are easily amenable to integration within PDMS-based microfluidics. NMR coils were constructed by the injection of liquid metal into solenoidal cavities created around a microchannel using consecutive replica molding and bonding of PDMS layers. This construction technique permits the integration of NMR coils with solenoidal, toroidal or other three-dimensional geometries within highly integrated microfluidic systems and are one step toward NMR-based chemical screening and analysis on chip. The current proof-of-principle implementation displays limited sensitivity and resolution due to the conductivity and magnetic susceptibilities of the construction materials. However, NMR measurements and finite-element simulations made with the current device geometry indicate that optimization of these materials will allow for the collection of spectra from sub-millimolar concentration samples in less than 1 nL of solution.

  7. Device for measurement of power and shape of radio frequency pulses in nuclear magnetic resonance

    Science.gov (United States)

    Pfeffer, M.; Řezníček, R.; Křišťan, P.; Štěpánková, H.

    2012-05-01

    A design of an instrument to measure the power and shape of radio frequency (RF) pulses operating in a broad frequency range is described. The device is capable of measuring the pulse power up to 500 W of both CW and extremely short (˜1 μs) RF pulses of arbitrary period. The pulse envelope can be observed on a logarithmic scale on a corresponding instrument output using an inexpensive storage oscilloscope. The instrument consists of a coaxial measurement head, the RF processing circuits and an AD conversion and display unit. The whole device is based on widely available integrated circuits; thus, good reproducibility and adaptability of the design is ensured. Since the construction is intended to be used in particular (but not solely) in nuclear magnetic resonance spectroscopy, we found it useful to provide a demonstration of two typical usage scenarios. Other application fields may comprise magnetic resonance imaging, radar and laser technology, power amplifier testing, etc.

  8. Classification of Wines Based on Combination of 1H NMR Spectroscopy and Principal Component Analysis

    Institute of Scientific and Technical Information of China (English)

    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. Assessing Heterogeneity of Osteolytic Lesions in Multiple Myeloma by 1H HR-MAS NMR Metabolomics

    Directory of Open Access Journals (Sweden)

    Laurette Tavel

    2016-10-01

    Full Text Available Multiple myeloma (MM is a malignancy of plasma cells characterized by multifocal osteolytic bone lesions. Macroscopic and genetic heterogeneity has been documented within MM lesions. Understanding the bases of such heterogeneity may unveil relevant features of MM pathobiology. To this aim, we deployed unbiased 1H high-resolution magic-angle spinning (HR-MAS nuclear magnetic resonance (NMR metabolomics to analyze multiple biopsy specimens of osteolytic lesions from one case of pathological fracture caused by MM. Multivariate analyses on normalized metabolite peak integrals allowed clusterization of samples in accordance with a posteriori histological findings. We investigated the relationship between morphological and NMR features by merging morphological data and metabolite profiling into a single correlation matrix. Data-merging addressed tissue heterogeneity, and greatly facilitated the mapping of lesions and nearby healthy tissues. Our proof-of-principle study reveals integrated metabolomics and histomorphology as a promising approach for the targeted study of osteolytic lesions.

  10. Contributed review: nuclear magnetic resonance core analysis at 0.3 T.

    Science.gov (United States)

    Mitchell, Jonathan; Fordham, Edmund J

    2014-11-01

    Nuclear magnetic resonance (NMR) provides a powerful toolbox for petrophysical characterization of reservoir core plugs and fluids in the laboratory. Previously, there has been considerable focus on low field magnet technology for well log calibration. Now there is renewed interest in the study of reservoir samples using stronger magnets to complement these standard NMR measurements. Here, the capabilities of an imaging magnet with a field strength of 0.3 T (corresponding to 12.9 MHz for proton) are reviewed in the context of reservoir core analysis. Quantitative estimates of porosity (saturation) and pore size distributions are obtained under favorable conditions (e.g., in carbonates), with the added advantage of multidimensional imaging, detection of lower gyromagnetic ratio nuclei, and short probe recovery times that make the system suitable for shale studies. Intermediate field instruments provide quantitative porosity maps of rock plugs that cannot be obtained using high field medical scanners due to the field-dependent susceptibility contrast in the porous medium. Example data are presented that highlight the potential applications of an intermediate field imaging instrument as a complement to low field instruments in core analysis and for materials science studies in general.

  11. Two lanthanide-hydroxo clusters with different nuclearity: Synthesis, structures, luminescent and magnetic properties

    Science.gov (United States)

    Li, Xi-Li; Zhu, Cancan; Zhang, Xue-Li; Hu, Ming; Wang, Ai-Ling; Xiao, Hong-Ping

    2017-01-01

    Under the identical reaction conditions, two new TbIII and SmIII-hydroxo clusters with different nuclearity have been prepared and characterized by X-ray crystallography, spectroscopic methods and magnetic measurements. Solid-state structure analyses reveal that the TbIII cluster shows a pentanuclear square pyramidal shape of the composition [Tb5(μ3-OH)4(μ4-OH)(dbm)10]·2H2O (1, dbm- = dibenzoylmethanate) with the dbm ligands presenting two types of coordination modes [η2-and (μ-O)-η2-]. The SmIII species presents a tetranuclear parallelogram structure formulated as [Sm4(μ3-OH)2(dbm)10]·12H2O (2), and three types of coordination modes [η2-, (μ-O)-η2- and (μ-O)2-η2-] for dbm ligands are observed. The measurements of magnetic properties indicate that the direct-current (dc) magnetic behaviors of two clusters mainly result from the thermal depopulation of the Stark sublevels of the TbIII and SmIII ions, respectively. Meanwhile, alternating current (ac) magnetic susceptibility of 1 is also assessed. Investigations on luminescence properties show that 2 displays characteristic emission of the SmIII ion in visible range, while 1 does not exhibit any detectable emission. The interpretations of different emission behaviors for 1 and 2 are also presented in detail.

  12. Contributed Review: Nuclear magnetic resonance core analysis at 0.3 T

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Jonathan, E-mail: JMitchell16@slb.com; Fordham, Edmund J. [Schlumberger Gould Research, High Cross, Madingley Road, Cambridge CB3 0EL (United Kingdom)

    2014-11-15

    Nuclear magnetic resonance (NMR) provides a powerful toolbox for petrophysical characterization of reservoir core plugs and fluids in the laboratory. Previously, there has been considerable focus on low field magnet technology for well log calibration. Now there is renewed interest in the study of reservoir samples using stronger magnets to complement these standard NMR measurements. Here, the capabilities of an imaging magnet with a field strength of 0.3 T (corresponding to 12.9 MHz for proton) are reviewed in the context of reservoir core analysis. Quantitative estimates of porosity (saturation) and pore size distributions are obtained under favorable conditions (e.g., in carbonates), with the added advantage of multidimensional imaging, detection of lower gyromagnetic ratio nuclei, and short probe recovery times that make the system suitable for shale studies. Intermediate field instruments provide quantitative porosity maps of rock plugs that cannot be obtained using high field medical scanners due to the field-dependent susceptibility contrast in the porous medium. Example data are presented that highlight the potential applications of an intermediate field imaging instrument as a complement to low field instruments in core analysis and for materials science studies in general.

  13. Direct Analysis of Free and Sulfite-Bound Carbonyl Compounds in Wine by Two-Dimensional Quantitative Proton and Carbon Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Nikolantonaki, Maria; Magiatis, Prokopios; Waterhouse, Andrew L

    2015-11-03

    Recent developments that have accelerated 2D NMR methods and improved quantitation have made these methods accessible analytical procedures, and the large signal dispersion allows for the analysis of complex samples. Few natural samples are as complex as wine, so the application to challenges in wine analysis look promising. The analysis of carbonyl compounds in wine, key oxidation products, is complicated by a multitude of kinetically reversible adducts, such as acetals and sulfonates, so that sample preparation steps can generate complex interferences. These challenges could be overcome if the compounds could be quantified in situ. Here, two-dimensional ((1)H-(1)H) homonuclear and heteronuclear ((13)C-(1)H) single quantum correlations (correlation spectroscopy, COSY, and heteronuclear single quantum coherence, HSQC) nuclear magnetic resonance spectra of undiluted wine samples were observed at natural abundance. These techniques achieve simultaneous direct identification and quantitation of acetaldehyde, pyruvic acid, acetoin, methylglyoxal, and α-ketoglutaric acid in wine with only a small addition of D2O. It was also possible to observe and sometimes quantify the sulfite, hydrate, and acetal forms of the carbonyl compounds. The accuracy of the method was tested in wine samples by spiking with a mixture of all analytes at different concentrations. The method was applied to 15 wine samples of various vintages and grape varieties. The application of this method could provide a powerful tool to better understand the development, evolution, and perception of wine oxidation and insight into the impact of these sulfite bound carbonyls on antimicrobial and antioxidant action by SO2.

  14. 1H-MRS结合LCModel软件对原发性帕金森病的诊断价值%Diagnostic value of proton magnetic resonance spectroscopy and LCModei in idiopathic Parkinson disease

    Institute of Scientific and Technical Information of China (English)

    钟小梅; 黄飚; 梁长虹; 罗海营; 王丽娟; 王广谊; 张玉虎

    2012-01-01

    目的 应用1 H-MRS结合LCModel软件对原发性帕金森病(PD)患者的脑代谢物浓度进行定量分析,并探讨其在PD诊断中的价值.方法 选取原发性PD患者31例(PD组)及正常对照组20名,采用单体素点解析波谱序列扫描对大脑一侧豆状核及双侧黑质的脑代谢物进行测定,利用MR仪自带的Sage波谱处理软件及LCModel软件分别对采集的数据进行后处理,并将PD组及正常对照组的数据进行比较.结果 PD组豆状核及黑质的tNAA浓度、黑质的tCr浓度均低于正常对照组(P均<0.05).两组豆状核及黑质的tCho浓度及tNAA/tCr、tCho/tCr浓度比的差异均无统计学意义.此外,由MR自带的Sage软件计算的豆状核及黑质的NAA/Cr、Cho/Cr比值,PD组与正常对照组比较差异均无统计学意义.结论 1H-MRS结合LCModel软件可以对脑代谢物浓度进行定量分析,其在原发性PD的诊断中具有一定应用前景.%Objective To explore the diagnostic value of ' H-MRS and LCModel software in idiopathic Parkinson disease (PD). Methods 'H-MRS of the lentiform nucleus and substantia nigra were performed on 31 patients with PD (PD group) and 20 healthy subjects (control group). Single voxel PRESS sequence was used to assess the metabolic changes. The data of spectra were post-processed using LCModel software and Sage software in 3. 0T MR scanner and compared between two groups. Results Compared with the control group, both the concentrations of tNAA in the lentiform nucleus and substantia nigra, as well as the concentrations of tCr in the substantia nigra were significantly lower in PD group (all P <0. 05). No significant differences between two groups were found in tCho concentrations, tNAA/tCr, tCho/tCr and the ratios of NAA/Cr and Cho/Cr in the lentiform nucleus and substantia nigra which were calculated by Sage software. Conclusion ' H-MRS combined with LCModel software can quantify the concentration of brain metabolite and detect the abnormal

  15. 联合应用ESI MS和1H NMR分析含笑属植物种子磷脂%Application of ESI-MS combined with 1 H NMR in analyzing seed phospolipids of six species of Michelia

    Institute of Scientific and Technical Information of China (English)

    唐安军; Naomichi BAbA

    2012-01-01

    To date,there was no example to authenticate seed phospholipids based on their fingerprinting.By means of electrospray ionization mass spectrometry(ESI MS)and proton nuclear magnetic resonance(1 H NMR)spectroscopy,phospholipids fraction extracted from seeds of six species from the genus Michelia were detected.It was firstly found that distinct difference in spectral fingerprinting region between m/z 895-910 in ESI MS and 5.30-5.40 mg/L in 1 H NMR among these six species.Thus,it suggested that the spectral differences shown by ESI MS and 1 H NMR among seeds of these six species could be applied to identify them.And in a wider sense,for analyzing seed phospholipids of other plant species,a combination of ESI MS AND NMR was an effective tool.%首次尝试利用电喷雾电离质谱(ESI MS)和氢原子核磁共振(1 H NMR)技术分析了含笑属六种植物种子的磷脂特性,发现在两个指纹图谱区发现明显的差异,即在质荷比(m/z)895-910(ESI MS)和5.30~5.40mg/L(1 H NMR)两个特异的区域存在显著差异.这些源于种子磷脂ESI/MS和1 H NMR的谱带差异可以被用来分析不同植物的种子的磷脂特征.而且,相似地,在更广的层面上,特异性的谱带差异可用于分析其他植物种子的磷脂组成和特性,辅助鉴定种子.

  16. Angstrom-Resolution Magnetic Resonance Imaging of Single Molecules via Wave-Function Fingerprints of Nuclear Spins

    Science.gov (United States)

    Ma, Wen-Long; Liu, Ren-Bao

    2016-08-01

    Single-molecule sensitivity of nuclear magnetic resonance (NMR) and angstrom resolution of magnetic resonance imaging (MRI) are the highest challenges in magnetic microscopy. Recent development in dynamical-decoupling- (DD) enhanced diamond quantum sensing has enabled single-nucleus NMR and nanoscale NMR. Similar to conventional NMR and MRI, current DD-based quantum sensing utilizes the "frequency fingerprints" of target nuclear spins. The frequency fingerprints by their nature cannot resolve different nuclear spins that have the same noise frequency or differentiate different types of correlations in nuclear-spin clusters, which limit the resolution of single-molecule MRI. Here we show that this limitation can be overcome by using "wave-function fingerprints" of target nuclear spins, which is much more sensitive than the frequency fingerprints to the weak hyperfine interaction between the targets and a sensor under resonant DD control. We demonstrate a scheme of angstrom-resolution MRI that is capable of counting and individually localizing single nuclear spins of the same frequency and characterizing the correlations in nuclear-spin clusters. A nitrogen-vacancy-center spin sensor near a diamond surface, provided that the coherence time is improved by surface engineering in the near future, may be employed to determine with angstrom resolution the positions and conformation of single molecules that are isotope labeled. The scheme in this work offers an approach to breaking the resolution limit set by the "frequency gradients" in conventional MRI and to reaching the angstrom-scale resolution.

  17. [Value of the nuclear magnetic cholangio resonance in the study of the patient with jaundice].

    Science.gov (United States)

    Gramática, L; Struni, M; Carranza, D; Verasay, G; Taborda, B; Caballero, F; Gramática, L

    1999-01-01

    This report analyse the results about forty three (43) patients, thirty six (36) of which showed an extrahepatic obstructive biliary Syndrome was made evident by ultrasonography, five (5) with a cholecistolithiasis and doubtful history of jaundice were evaluated to carry out a video-surgery procedure and two (2) patients whom hepatic-yeyunostomy had been practiced, a control of anastomosis in postoperative period was required. Nuclear Magnetic Resonance and Operative Cholangiography findings were correlated and afterward with the anatomopathological studies when they arrived. In all cases the Nuclear Magnetic Cholangio Resonance (NMCR) let us prove the diagnosis of extrahepatic biliary obstruction determining with precision furthermore the topographical site of the lesion. Respecting the aetiology of obstruction, NMCR was accurate in 34 out of 36 cases (94.4%). In conclusion Cholangio-Resonance is an excellent diagnostic method to evaluate biliary ductal system including anatomic changes. However, there are some limitations yet in order to determine the aetiology of lesions about extrahepatic biliary via extremes. We emphasize its features such as non-invasive, little operating dependent, and without morbimortality that become it as a method of choice to study the biliary via from a diagnostic viewpoint.

  18. Charge order and low frequency spin dynamics in lanthanum cuprates revealed by Nuclear Magnetic Resonance

    Energy Technology Data Exchange (ETDEWEB)

    Grafe, H.J.; Vyalikh, A.; Vavilova, J.; Buchner, B. [IFW Dresden, Institute for Solid State Research, Dresden (Germany); Curro, N.J. [Department of Physics, University of California, Davis, CA (United States); Young, B.L. [Department of Electrophysics, National Chiao Tung University, Hsinchu, Taiwan (China); Gu, G.D.; Hucker, M. [Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY (United States); Vavilova, J. [Kazan Zavoiskiy Physical-Technical Institute, Kazan (Russian Federation)

    2010-10-15

    We report detailed {sup 17}O, {sup 139}La, and {sup 63,65}Cu Nuclear Magnetic Resonance (NMR) and Nuclear Quadrupole Resonance (NQR) measurements in a stripe ordered La{sub 1.875}Ba{sub 0.125}CuO{sub 4} single crystal and in oriented powder samples of La{sub 1.8-x}Eu{sub 0.2}Sr{sub x}CuO{sub 4}. We observe a partial wipe out of the {sup 17}O NMR intensity and a simultaneous drop of the {sup 17}O electric field gradient (EFG) at low temperatures where the spin stripe order sets in. In contrast, the {sup 63,65}Cu intensity is completely wiped out at the same temperature. The drop of the {sup 17}O quadrupole frequency is compatible with a charge stripe order. The {sup 17}O spin lattice relaxation rate shows a peak similar to that of the {sup 139}La, which is of magnetic origin. This peak is doping dependent and is maximal at x {approx} 1/8. (authors)

  19. Nanoscale β-nuclear magnetic resonance depth imaging of topological insulators.

    Science.gov (United States)

    Koumoulis, Dimitrios; Morris, Gerald D; He, Liang; Kou, Xufeng; King, Danny; Wang, Dong; Hossain, Masrur D; Wang, Kang L; Fiete, Gregory A; Kanatzidis, Mercouri G; Bouchard, Louis-S

    2015-07-14

    Considerable evidence suggests that variations in the properties of topological insulators (TIs) at the nanoscale and at interfaces can strongly affect the physics of topological materials. Therefore, a detailed understanding of surface states and interface coupling is crucial to the search for and applications of new topological phases of matter. Currently, no methods can provide depth profiling near surfaces or at interfaces of topologically inequivalent materials. Such a method could advance the study of interactions. Herein, we present a noninvasive depth-profiling technique based on β-detected NMR (β-NMR) spectroscopy of radioactive (8)Li(+) ions that can provide "one-dimensional imaging" in films of fixed thickness and generates nanoscale views of the electronic wavefunctions and magnetic order at topological surfaces and interfaces. By mapping the (8)Li nuclear resonance near the surface and 10-nm deep into the bulk of pure and Cr-doped bismuth antimony telluride films, we provide signatures related to the TI properties and their topological nontrivial characteristics that affect the electron-nuclear hyperfine field, the metallic shift, and magnetic order. These nanoscale variations in β-NMR parameters reflect the unconventional properties of the topological materials under study, and understanding the role of heterogeneities is expected to lead to the discovery of novel phenomena involving quantum materials.

  20. Principles and some applications of ''zero field nuclear magnetic resonance''

    Energy Technology Data Exchange (ETDEWEB)

    Llor, A.; Virlet, J.

    1987-10-01

    The method known as ''zero field NMR'' is reviewed. The technique allows the observation of nuclear dipolar and quadrupolar interactions in powder samples, which may otherwise be possible in high field on monocristals only. The anisotropy due to the magnetic field is removed although sensitivity is preserved. This method is compared to other Nuclear Resonance spectroscopies: its originality lies in the measurement of the coherent evolution of the system in zero field after a perturbation induced by suddenly switching the magnetic field. The Fourier transform of the ''zero field free induction decay'' then gives the ''zero field spectrum''. The ideal experiment is described with its adaptations due to experimental constraints, as realized in our laboratory at Saclay and in the laboratory of A. Pines at Berkeley. We present with our first measurements a review of most of the results published to date on spin 1/2 as well as spin 1/2 (quadrupolar) nuclei. Possible future developments of the method are also discussed.

  1. Monitoring lactic acid production during milk fermentation by in situ quantitative proton nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Bouteille, R; Gaudet, M; Lecanu, B; This, H

    2013-04-01

    When fermenting milk, lactic bacteria convert part of α- and β-lactoses into d- and l- lactic acids, causing a pH decrease responsible for casein coagulation. Lactic acid monitoring during fermentation is essential for the control of dairy gel textural and organoleptic properties, and is a way to evaluate strain efficiency. Currently, titrations are used to follow the quantity of acids formed during jellification of milk but they are not specific to lactic acid. An analytical method without the use of any reagent was investigated to quantify lactic acid during milk fermentation: in situ quantitative proton nuclear magnetic resonance spectroscopy. Two methods using in situ quantitative proton nuclear magnetic resonance spectroscopy were compared: (1) d- and l-lactic acids content determination, using the resonance of their methyl protons, showing an increase from 2.06 ± 0.02 to 8.16 ± 0.74 g/L during 240 min of fermentation; and (2) the determination of the α- and β-lactoses content, decreasing from 42.68 ± 0.02 to 30.76 ± 1.75 g/L for the same fermentation duration. The ratio between the molar concentrations of produced lactic acids and consumed lactoses enabled cross-validation, as the value (2.02 ± 0.18) is consistent with lactic acid bacteria metabolism.

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

    Science.gov (United States)

    Roy, Beas

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

  3. Relativistic theory of nuclear magnetic resonance parameters in a Gaussian basis representation.

    Science.gov (United States)

    Kutzelnigg, Werner; Liu, Wenjian

    2009-07-28

    The calculation of NMR parameters from relativistic quantum theory in a Gaussian basis expansion requires some care. While in the absence of a magnetic field the expansion in a kinetically balanced basis converges for the wave function in the mean and for the energy with any desired accuracy, this is not necessarily the case for magnetic properties. The results for the magnetizability or the nuclear magnetic shielding are not even correct in the nonrelativistic limit (nrl) if one expands the original Dirac equation in a kinetically balanced Gaussian basis. This defect disappears if one starts from the unitary transformed Dirac equation as suggested by Kutzelnigg [Phys. Rev. A 67, 032109 (2003)]. However, a new difficulty can arise instead if one applies the transformation in the presence of the magnetic field of a point nucleus. If one decomposes certain contributions, the individual terms may diverge, although their sum is regular. A controlled cancellation may become difficult and numerical instabilities can arise. Various ways exist to avoid these singularities and at the same time get the correct nrl. There are essentially three approaches intermediate between the transformed and the untransformed formulation, namely, the bispinor decomposition, the decomposition of the lower component, and the hybrid unitary transformation partially at operator and partially at matrix level. All three possibilities were first considered by Xiao et al. [J. Chem. Phys. 126, 214101 (2007)] in a different context and in a different nomenclature. Their analysis and classification in a more general context are given here for the first time. Use of an extended balanced basis has no advantages and has other drawbacks and is not competitive, while the use of a restricted magnetic balance basis can be justified.

  4. Cardiovascular imaging in the diagnosis and monitoring of cardiotoxicity: cardiovascular magnetic resonance and nuclear cardiology.

    Science.gov (United States)

    Pepe, Alessia; Pizzino, Fausto; Gargiulo, Paola; Perrone-Filardi, Pasquale; Cadeddu, Christian; Mele, Donato; Monte, Ines; Novo, Giuseppina; Zito, Concetta; Di Bella, Gianluca

    2016-05-01

    Chemotherapy-induced cardiotoxicity (CTX) is a determining factor for the quality of life and mortality of patients administered potentially cardiotoxic drugs and in long-term cancer survivors. Therefore, prevention and early detection of CTX are highly desirable, as is the exploration of alternative therapeutic strategies and/or the proposal of potentially cardioprotective treatments. In recent years, cardiovascular imaging has acquired a pivotal role in this setting. Although echocardiography remains the diagnostic method most used to monitor cancer patients, the need for more reliable, reproducible and accurate detection of early chemotherapy-induced CTX has encouraged the introduction of second-line advanced imaging modalities, such as cardiac magnetic resonance (CMR) and nuclear techniques, into the clinical setting. This review of the Working Group on Drug Cardiotoxicity and Cardioprotection of the Italian Society of Cardiology aims to afford an overview of the most important findings from the literature about the role of CMR and nuclear techniques in the management of chemotherapy-treated patients, describe conventional and new parameters for detecting CTX from both diagnostic and prognostic perspectives and provide integrated insight into the role of CMR and nuclear techniques compared with other imaging tools and versus the positions of the most important international societies.

  5. Structure, spectra and antioxidant action of ascorbic acid studied by density functional theory, Raman spectroscopic and nuclear magnetic resonance techniques.

    Science.gov (United States)

    Singh, Gurpreet; Mohanty, B P; Saini, G S S

    2016-02-15

    Structure, vibrational and nuclear magnetic resonance spectra, and antioxidant action of ascorbic acid towards hydroxyl radicals have been studied computationally and in vitro by ultraviolet-visible, nuclear magnetic resonance and vibrational spectroscopic techniques. Time dependant density functional theory calculations have been employed to specify various electronic transitions in ultraviolet-visible spectra. Observed chemical shifts and vibrational bands in nuclear magnetic resonance and vibrational spectra, respectively have been assigned with the help of calculations. Changes in the structure of ascorbic acid in aqueous phase have been examined computationally and experimentally by recording Raman spectra in aqueous medium. Theoretical calculations of the interaction between ascorbic acid molecule and hydroxyl radical predicted the formation of dehydroascorbic acid as first product, which has been confirmed by comparing its simulated spectra with the corresponding spectra of ascorbic acid in presence of hydrogen peroxide.

  6. Structure, spectra and antioxidant action of ascorbic acid studied by density functional theory, Raman spectroscopic and nuclear magnetic resonance techniques

    Science.gov (United States)

    Singh, Gurpreet; Mohanty, B. P.; Saini, G. S. S.

    2016-02-01

    Structure, vibrational and nuclear magnetic resonance spectra, and antioxidant action of ascorbic acid towards hydroxyl radicals have been studied computationally and in vitro by ultraviolet-visible, nuclear magnetic resonance and vibrational spectroscopic techniques. Time dependant density functional theory calculations have been employed to specify various electronic transitions in ultraviolet-visible spectra. Observed chemical shifts and vibrational bands in nuclear magnetic resonance and vibrational spectra, respectively have been assigned with the help of calculations. Changes in the structure of ascorbic acid in aqueous phase have been examined computationally and experimentally by recording Raman spectra in aqueous medium. Theoretical calculations of the interaction between ascorbic acid molecule and hydroxyl radical predicted the formation of dehydroascorbic acid as first product, which has been confirmed by comparing its simulated spectra with the corresponding spectra of ascorbic acid in presence of hydrogen peroxide.

  7. Nuclear magnetic resonance as a method of fluid mobility detection in porous media

    Science.gov (United States)

    Zhakov, Sergey; Loskutov, Valentin

    2016-04-01

    The nuclear magnetic resonance (NMR) method is widely used for studying the structure of porous media and processes taking place in such media. This method permits to determine porosity and pore-size distributions, which have direct practical application in various areas. The problem of porous media permeability determination is connected directly with extraction of hydrocarbons from pays and water from aquiferous layers. But it is impossible to measure directly amount of fluid past through the fixes cross section for determination of bed permeability. So various indirect approaches are used to find correlation of permeability value with porosity and pore size distribution which can be determined directly using NMR relaxometry. In contrast to porosity, permeability is dynamic characteristic of porous media so it may be measured correctly only in conditions of moving fluid. Natural porous medium has branched pore structure, so a chaotic component of fluid velocity will occur even for constant mean filtration fluid velocity. In the presence of magnetic field gradient this chaotic fluid velocity will produce additional spin dephasing and decrease of relaxation time [1]. Direct detecting of fluid movement in porous core samples through the Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence has been demonstrated and theoretical model and analysis was given. Experiments were made on a set of sandstone samples (Berea, Bentheimer, Castle Gate, Leopard) and with synthetic high-perm samples made of abrasive material. The experiments show that the NMR spin echo measurements permit to fix mean fluid velocity mm/sec. The experiments and the theoretical model show that for low fluid velocities the mean relaxation rate is proportional to fluid velocity . The results may serve as the basis for determination of mobility of liquids in porous media and permeability. 1. P.T.Callaghan. Principles of Nuclear Magnetic Resonance Microscopy. 1991, Oxford University Press.

  8. 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

    Directory of Open Access Journals (Sweden)

    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

  9. Subsecond spin relaxation times in quantum dots at zero applied magnetic field due to a strong electron-nuclear interaction.

    Science.gov (United States)

    Oulton, R; Greilich, A; Verbin, S Yu; Cherbunin, R V; Auer, T; Yakovlev, D R; Bayer, M; Merkulov, I A; Stavarache, V; Reuter, D; Wieck, A D

    2007-03-09

    A key to ultralong electron spin memory in quantum dots (QDs) at zero magnetic field is the polarization of the nuclei, such that the electron spin is stabilized along the average nuclear magnetic field. We demonstrate that spin-polarized electrons in n-doped (In,Ga)As/GaAs QDs align the nuclear field via the hyperfine interaction. A feedback onto the electrons occurs, leading to stabilization of their polarization due to formation of a nuclear spin polaron [I. A. Merkulov, Phys. Solid State 40, 930 (1998)]. Spin depolarization of both systems is consequently greatly reduced, and spin memory of the coupled electron-nuclear spin system is retained over 0.3 sec at temperature of 2 K.

  10. Multi-dimensional Inversion Modeling of Surface Nuclear Magnetic Resonance (SNMR Data for Groundwater Exploration

    Directory of Open Access Journals (Sweden)

    Warsa

    2014-07-01

    Full Text Available Groundwater is an important economic source of water supply for drinking water and irrigation water for agriculture. Surface nuclear magnetic resonance (SNMR sounding is a relatively new geophysical method that can be used to determine the presence of culturally and economically important substances, such as subsurface water or hydrocarbon distribution. SNMR sounding allows the determination of water content and pore size distribution directly from the surface. The SNMR method is performed by stimulating an alternating current pulse through an antenna at the surface in order to confirm the existence of water in the subsurface. This paper reports the development of a 3-D forward modeling code for SNMR amplitudes and decay times, after which an improved 2-D and 3-D inversion algorithm is investigated, consisting of schemes for regularizing model parameterization. After briefly reviewing inversion schemes generally used in geophysics, the special properties of SNMR or magnetic resonance sounding (MRS inversion are evaluated. We present an extension of MRS to magnetic resonance tomography (MRT, i.e. an extension for 2-D and 3-D investigation, and the appropriate inversions.

  11. On-line monitoring of chemical reactions by using bench-top nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Danieli, E; Perlo, J; Duchateau, A L L; Verzijl, G K M; Litvinov, V M; Blümich, B; Casanova, F

    2014-10-06

    Real-time nuclear magnetic resonance (NMR) spectroscopy measurements carried out with a bench-top system installed next to the reactor inside the fume hood of the chemistry laboratory are presented. To test the system for on-line monitoring, a transfer hydrogenation reaction was studied by continuously pumping the reaction mixture from the reactor to the magnet and back in a closed loop. In addition to improving the time resolution provided by standard sampling methods, the use of such a flow setup eliminates the need for sample preparation. Owing to the progress in terms of field homogeneity and sensitivity now available with compact NMR spectrometers, small molecules dissolved at concentrations on the order of 1 mmol L(-1) can be characterized in single-scan measurements with 1 Hz resolution. Owing to the reduced field strength of compact low-field systems compared to that of conventional high-field magnets, the overlap in the spectrum of different NMR signals is a typical situation. The data processing required to obtain concentrations in the presence of signal overlap are discussed in detail, methods such as plain integration and line-fitting approaches are compared, and the accuracy of each method is determined. The kinetic rates measured for different catalytic concentrations show good agreement with those obtained with gas chromatography as a reference analytical method. Finally, as the measurements are performed under continuous flow conditions, the experimental setup and the flow parameters are optimized to maximize time resolution and signal-to-noise ratio.

  12. High field nuclear magnetic resonance in transition metal substituted BaFe2As2

    Science.gov (United States)

    Garitezi, T. M.; Lesseux, G. G.; Rosa, P. F. S.; Adriano, C.; Reyes, A. P.; Kuhns, P. L.; Pagliuso, P. G.; Urbano, R. R.

    2014-05-01

    We report high field 75As nuclear magnetic resonance (NMR) measurements on Co and Cu substituted BaFe2As2 single crystals displaying same structural/magnetic transition T0≃128 K. From our anisotropy studies in the paramagnetic state, we strikingly found virtually identical quadrupolar splitting and consequently the quadrupole frequency νQ≃2.57(1) MHz for both compounds, despite the claim that each Cu delivers 2 extra 3d electrons in BaFe2As2 compared to Co substitution. These results allow us to conclude that a subtle change in the crystallographic structure, particularly in the Fe-As tetrahedra, must be the most probable tuning parameter to determine T0 in this class of superconductors rather than electronic doping. Furthermore, our NMR data around T0 suggest coexistence of tetragonal/paramagnetic and orthorhombic/antiferromagnetic phases between the structural and the spin density wave magnetic phase transitions, similarly to what was reported for K-doped BaFe2As2 [Urbano et al., Phys. Rev. Lett. 105, 107001 (2010)].

  13. A solid state nuclear magnetic resonance study of industrial inorganic pigments

    CERN Document Server

    Dajda, N

    2002-01-01

    Nuclear magnetic resonance has been used to look at a number of colourful ceramic pigment systems, most of which are sold commercially in large quantities. Doped zircon (ZrSiO sub 4) pigments were examined using sup 1 sup 9 F, sup 2 sup 3 Na, sup 2 sup 9 Si, sup 5 sup 1 V and sup 9 sup 1 Zr NMR. In these systems, paramagnetic species are incorporated into the sample in small quantities creating the colourful pigment. The impurity dopants in the systems studied either dope directly into lattice sites in the zircon, or form an extra chemical phase. NMR was able to distinguish between these two doping mechanisms in a number of doped zircon pigments. Most spectra showed effects which were due to the magnetic influence of paramagnetic colouring species, and the strength of the interaction depended on the magnetic moment of the ion containing the unpaired electron. In the case of vanadium doped zircon, the moment was small enough that it allowed extra contact shifted peaks to be resolved in the spectra which indica...

  14. Diamond nitrogen vacancy electronic and nuclear spin-state anti-crossings under weak transverse magnetic fields

    Science.gov (United States)

    Clevenson, Hannah; Chen, Edward; Dolde, Florian; Teale, Carson; Englund, Dirk; Braje, Danielle

    2016-05-01

    We report on detailed studies of electronic and nuclear spin states in the diamond nitrogen vacancy (NV) center under moderate transverse magnetic fields. We numerically predict and experimentally verify a previously unobserved NV ground state hyperfine anti-crossing occurring at magnetic bias fields as low as tens of Gauss - two orders of magnitude lower than previously reported hyperfine anti-crossings at ~ 510 G and ~ 1000 G axial magnetic fields. We then discuss how this regime can be optimized for magnetometry and other sensing applications and propose a method for how the nitrogen-vacancy ground state Hamiltonian can be manipulated by small transverse magnetic fields to polarize the nuclear spin state. Acknowlegement: The Lincoln Laboratory portion of this work is sponsored by the Assistant Secretary of Defense for Research & Engineering under Air Force Contract #FA8721-05-C-0002. Opinions, interpretations, conclusions and recommendations are those of the authors and are not necessarily endorsed by the United States Government.

  15. 1H NMR Studies of MgH2

    Science.gov (United States)

    Itoh, Yutaka; Kado, Ryoichi

    We report on 1H NMR studies of commercially available powder MgH2 exposed to air and maybe humidity, which has been believed to be a promising material for hydrogen storage. The Fourier transform of the free-induction decay of the protons indicatesd superposition of broad and narrow components in the NMR spectrum, while the Fourier transform of the 1H nuclear spin-echo reproduced the narrow component. With cooling down below room temperature, the ratio of the narrow peak to the broad spectrum decreased. The broad spectrum is associated with direct dipolar coupled protons on an inhomogeneous rigid lattice. The narrow peak is associated with interstitial protons with more inhomogeneous surroundings.

  16. 1H NMR-based serum metabolic profiling in compensated and decompensated cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Su-Wen Qi; Zhi-Guang Tu; Wu-Jian Peng; Lin-Xian Wang; Xin Ou-Yang; An-Ji Cai; Yong Dai

    2012-01-01

    AIM: To study the metabolic profiling of serum samples from compensated and decompensated cirrhosis patients.METHODS: A pilot metabolic profiling study was conducted using three groups: compensated cirrhosis patients (n = 30), decompensated cirrhosis patients (n = 30) and healthy controls (n = 30). A 1H nuclear magnetic resonance (NMR)-based metabonomics approach was used to obtain the serum metabolic profiles of the samples. The acquired data were processed by multivariate principal component analysis and orthogonal partial least-squares discriminant analysis (OPLS-DA). RESULTS: The OPLS-DA model was capable of distinguishing between decompensated and compensated cirrhosis patients, with an R2Y of 0.784 and a Q2Y of 0.598. Twelve metabolites, such as pyruvate, phenylalanine and succinate, were identified as the most influential factors for the difference between the two groups. The validation of the diagnosis prediction showed that the accuracy of the OPLSDA model was 85% (17/20). CONCLUSION: 1H NMR spectra combined with pattern recognition analysis techniques offer a new way to diagnose compensated and decompensated cirrhosis in the future.

  17. Environmentally Benign Syntheses and Characterization of 4- Aryldihydropyrimidin-2(1H-ones

    Directory of Open Access Journals (Sweden)

    Shafqat Syed Salman

    2017-01-01

    Full Text Available A general, simple, efficient, cost-effective and environmental benign procedure for the syntheses of 4-aryl-3,4-dihydropyrimidin-2(1H-ones (DHPMs has been developed. The reaction is efficiently catalysed by using various amino acids viz., glycine, L-proline, L-cysteine, leucine and tryptophan. Reactions give excellent yields under reflux conditions. The chemical structures of these compounds were identified by Fourier Transform-Infra Red Spectroscopy (FT-IR, Gas Chromatography-Mass Spectroscopy (GC-MS and Nuclear Magnetic Resonance Spectroscopy (1H NMR. Physical parameters such as m.p., mixed m.p. as well as TLC also helped to characterize the expected products. The progress of the reaction time and purity was checked by TLC and the products were purified by recrystallization using ethyl acetate as a solvent. The synthesized molecule has numerous biological applications as it is anti-microbial, anti-inflammatory and anti-hypertensive in character.

  18. 1H-NMR characterization of poly(ethylene glycol) and polydimethylsiloxane copolymer

    Science.gov (United States)

    Zainuddin, Ain Athirah; Othaman, Rizafizah; Noor, Wan Syaidatul Aqma Wan Mohd; Anuar, Farah Hannan

    2016-11-01

    This paper describes the synthesis and characterization of poly(ethylene glycol) (PEG) and polydimethylsiloxane (PDMS) copolymers. The copolymers were synthesized by reacting hydroxyl group (-OH) of poly(ethylene glycol) (PEG) and polydimetylsiloxane (PDMS) with isocyanate group (R-N=C=O) of 1,6-hexamethylene diisocyanate (HMDI). The reaction was carried out at room temperature. The copolymers were synthesized in three different compositions which differ in molar ratios of PEG to PDMS. The ratios (PEG:PDMS) used were 2:6. 3:5 and 4:4. The formation of the copolymers was characterized by 1H Nuclear Magnetic Resonance (1H-NMR) for structural determination. The presence of proton signal at 4.80 ppm which belongs to the proton of urethane group indicates the formation of urethane links. The formation of urethane links showed that two homopolymers were linked together by HMDI to form longer copolymer chains. It is worth to note that the sequence of PEG and PDMS along the copolymer chain is random.

  19. Rationale for the combination of nuclear medicine with magnetic resonance for pre-clinical imaging.

    Science.gov (United States)

    Wagenaar, Douglas J; Kapusta, Maciej; Li, Junqiang; Patt, Bradley E

    2006-08-01

    Multi-modality combinations of SPECT/CT and PET/CT have proven to be highly successful in the clinic and small animal SPECT/CT and PET/CT are becoming the norm in the research and drug development setting. However, the use of ionizing radiation from a high-resolution CT scanner is undesirable in any setting and particularly in small animal imaging (SAI), in laboratory experiments where it can result in radiation doses of sufficient magnitude that the experimental results can be influenced by the organism's response to radiation. The alternative use of magnetic resonance (MR) would offer a high-resolution, non-ionizing method for anatomical imaging of laboratory animals. MR brings considerably more than its 3D anatomical capability, especially regarding the imaging of laboratory animals. Dynamic MR imaging techniques can facilitate studies of perfusion, oxygenation, and diffusion amongst others. Further, MR spectroscopy can provide images that can be related to the concentration of endogenous molecules in vivo. MR imaging of injected contrast agents extends MR into the domain of molecular imaging. In combination with nuclear medicine (NM) SPECT and PET modalities in small animal imaging, MR would facilitate studies of dynamic processes such as biodistribution, pharmacokinetics, and pharmacodynamics. However, the detectors for nearly all PET and SPECT systems are still based on vacuum tube technology, namely: photomultiplier tubes (PMT's) in which the signal is generated by transporting electrons over a substantial distance within an evacuated glass tube, making them inoperable in even small magnetic fields. Thus the combination of SPECT or PET with MR has not been practical until the recent availability of semiconductor detectors such as silicon avalanche photodiodes (APD's) for PET and CdZnTe (CZT) detectors for SPECT coupled with the availability of high-density low noise ASIC electronics to read out the semiconductor detectors. The strong advantage of these

  20. Characteristics of 1H-magnetic resonance spectroscopy of the radiation injury of brain%放射性脑损伤的磁共振氢质子波谱特点

    Institute of Scientific and Technical Information of China (English)

    罗柏宁; 郭媛; 张波; 梁康福; 孙庚喜

    2004-01-01

    背景:放射性脑损伤是鼻咽癌放射性治疗(简称放疗)后的严重并发症,其早期诊断目前仍有一定困难,而磁共振波谱(magnetic resonance spectroscopy,MRS)能无创性地检测脑组织细胞代谢,是对放疗后脑损伤检测较理想的手段和方法.目的:探讨磁共振波谱对放射性脑损伤的表达.设计:以诊断为依据,非随机化同期对照研究.单位:中山大学附属第一医院放射科.对象:对1998-10/2002-12临床证实因鼻咽癌行颈部鼻咽部放疗后,在中山大学附属第一医院放射科追踪治疗并行MRI和MRS检测76例(病变组).同期选择无鼻咽癌及放疗史的健康者25例用同样的方法进行检测作对照组.干预:用1.5T MR成像系统和氢波谱采集分析软件,对两组对象行常规?骀 MRI和MRS检测.波谱检测序列:单容积波谱定位序列,激励回波探测法,扫描参数TR 2 000 ms,TE 135 ms,FOV 180 mm×180 mm,感兴趣区取20 mm×20 mm×20 mm(8 cm3),采集时间6.5 min.MRS波峰形态分析,按NAA,Cr,Cho波峰的高低排列不同组合,分Ⅰ型、Ⅱ型和Ⅲ型.波峰积分值分析,取病变中央区、边沿区和正常区的3个主要波峰:NAA峰,Cr峰,Cho峰,用随机的软件包测各自的积分值并分别计算NAA/Cr,NAA/(Cr+Cho)和Cho/Cr的积分值比.主要观察指标:①病变组和对照组不同部位波型.②病变组和对照组不同部位各波峰积分值及其比值.结果:健康对照组MRS波峰形态主要呈Ⅰ型86.67%.病变组:病灶中央区以Ⅱ型为主68.42%,边缘区波形组合以Ⅰ型44.74%和Ⅲ型39.47%为多,正常区以Ⅰ型为主84.21%.病变组各区间的NAA,Cr,Cho,NAA/Cr,sNAA/(Cr+Cho)和Cho/Cr的积分值及比值有统计学差异(P<0.01).结论:MRS的波形及脑化合物的积分值变化能提示放射性脑损伤的程度.Ⅱ型提示已有放射性脑损伤的存在,Ⅲ型加NAA/Cr,NAA/(Cr+Cho)的比值<1,则要考虑有放射性脑损伤可能.%BACKGROUND: The radiation injury of brain

  1. Measurement of {sup 1}H-{sup 15}N and {sup 1}H-{sup 13}C residual dipolar couplings in nucleic acids from TROSY intensities

    Energy Technology Data Exchange (ETDEWEB)

    Ying Jinfa [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States); Wang Jinbu [National Cancer Institute, National Institutes of Health, Structural Biophysics Laboratory (United States); Grishaev, Alex [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States); Yu Ping; Wang Yunxing [National Cancer Institute, National Institutes of Health, Structural Biophysics Laboratory (United States); Bax, Ad, E-mail: bax@nih.gov [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)

    2011-09-15

    Analogous to the recently introduced ARTSY method for measurement of one-bond {sup 1}H-{sup 15}N residual dipolar couplings (RDCs) in large perdeuterated proteins, we introduce methods for measurement of base {sup 13}C-{sup 1}H and {sup 15}N-{sup 1}H RDCs in protonated nucleic acids. Measurements are based on quantitative analysis of intensities in {sup 1}H-{sup 15}N and {sup 13}C-{sup 1}H TROSY-HSQC spectra, and are illustrated for a 71-nucleotide adenine riboswitch. Results compare favorably with those of conventional frequency-based measurements in terms of completeness and convenience of use. The ARTSY method derives the size of the coupling from the ratio of intensities observed in two TROSY-HSQC spectra recorded with different dephasing delays, thereby minimizing potential resonance overlap problems. Precision of the RDC measurements is limited by the signal-to-noise ratio, S/N, achievable in the 2D TROSY-HSQC reference spectrum, and is approximately given by 30/(S/N) Hz for {sup 15}N-{sup 1}H and 65/(S/N) Hz for {sup 13}C-{sup 1}H. The signal-to-noise ratio of both {sup 1}H-{sup 15}N and {sup 1}H-{sup 13}C spectra greatly benefits when water magnetization during the experiments is not perturbed, such that rapid magnetization transfer from bulk water to the nucleic acid, mediated by rapid amino and hydroxyl hydrogen exchange coupled with {sup 1}H-{sup 1}H NOE transfer, allows for fast repetition of the experiment. RDCs in the mutated helix 1 of the riboswitch are compatible with nucleotide-specifically modeled, idealized A-form geometry and a static orientation relative to the helix 2/3 pair, which differs by ca 6 Degree-Sign relative to the X-ray structure of the native riboswitch.

  2. Observation of Time-Invariant Coherence in a Nuclear Magnetic Resonance Quantum Simulator.

    Science.gov (United States)

    Silva, Isabela A; Souza, Alexandre M; Bromley, Thomas R; Cianciaruso, Marco; Marx, Raimund; Sarthour, Roberto S; Oliveira, Ivan S; Lo Franco, Rosario; Glaser, Steffen J; deAzevedo, Eduardo R; Soares-Pinto, Diogo O; Adesso, Gerardo

    2016-10-14

    The ability to live in coherent superpositions is a signature trait of quantum systems and constitutes an irreplaceable resource for quantum-enhanced technologies. However, decoherence effects usually destroy quantum superpositions. It was recently predicted that, in a composite quantum system exposed to dephasing noise, quantum coherence in a transversal reference basis can stay protected for an indefinite time. This can occur for a class of quantum states independently of the measure used to quantify coherence, and it requires no control on the system during the dynamics. Here, such an invariant coherence phenomenon is observed experimentally in two different setups based on nuclear magnetic resonance at room temperature, realizing an effective quantum simulator of two- and four-qubit spin systems. Our study further reveals a novel interplay between coherence and various forms of correlations, and it highlights the natural resilience of quantum effects in complex systems.

  3. Nuclear magnetic polarizability and the slope of the Thomas-Reiche-Kuhn-Levinger-Bethe sum rule

    CERN Document Server

    Gorchtein, Mikhail

    2015-01-01

    Thomas-Reiche-Kuhn-Levinger-Bethe sum rule that relates the strength of the photoexcitation of the giant dipole resonance in a nucleus to the number of elementary scatterers-protons within that nucleus by means of a subtracted forward dispersion relation. I extend this dispersion relation consideration to the case of virtual photons and show that the size of the magnetic polarizability of a nucleus, under the assumption of a separation between the nuclear and hadronic scales, may be related to the slope of the transverse virtual photoabsorption cross section integrated over the energy. I check this approximate sum rule for the deuteron where necessary data is available, discuss possible applications and connection with other sum rules postulated in the literature.

  4. Theoretical approaches to control spin dynamics in solid-state nuclear magnetic resonance

    Indian Academy of Sciences (India)

    Eugene Stephane Mananga

    2015-12-01

    This article reviews theoretical approaches for controlling spin dynamics in solid-state nuclear magnetic resonance. We present fundamental theories in the history of NMR, namely, the average Hamiltonian and Floquet theories. We also discuss emerging theories such as the Fer and Floquet-Magnus expansions. These theories allow one to solve the time-dependent Schrodinger equation, which is still the central problem in spin dynamics of solid-state NMR. Examples from the literature that highlight several applications of these theories are presented, and particular attention is paid to numerical integrators and propagator operators. The problem of time propagation calculated with Chebychev expansion and the future development of numerical directions with the Cayley transformation are considered. The bibliography includes 190 references.

  5. Impurity detection in alkali-metal vapor cells via nuclear magnetic resonance

    Science.gov (United States)

    Patton, B.; Ishikawa, K.

    2016-11-01

    We use nuclear magnetic resonance spectroscopy of alkali metals sealed in glass vapor cells to perform in situ identification of chemical contaminants. The alkali Knight shift varies with the concentration of the impurity, which in turn varies with temperature as the alloy composition changes along the liquidus curve. Intentional addition of a known impurity validates this approach and reveals that sodium is often an intrinsic contaminant in cells filled with distilled, high-purity rubidium or cesium. Measurements of the Knight shift of the binary Rb-Na alloy confirm prior measurements of the shift's linear dependence on Na concentration, but similar measurements for the Cs-Na system demonstrate an unexpected nonlinear dependence of the Knight shift on the molar ratio. This non-destructive approach allows monitoring and quantification of ongoing chemical processes within the kind of vapor cells which form the basis for precise sensors and atomic frequency standards.

  6. Time-Domain Nuclear Magnetic Resonance Investigation of Water Dynamics in Different Ginger Cultivars.

    Science.gov (United States)

    Huang, Chongyang; Zhou, Qi; Gao, Shan; Bao, Qingjia; Chen, Fang; Liu, Chaoyang

    2016-01-20

    Different ginger cultivars may contain different nutritional and medicinal values. In this study, a time-domain nuclear magnetic resonance method was employed to study water dynamics in different ginger cultivars. Significant differences in transverse relaxation time T2 values assigned to the distribution of water in different parts of the plant were observed between Henan ginger and four other ginger cultivars. Ion concentration and metabolic analysis showed similar differences in Mn ion concentrations and organic solutes among the different ginger cultivars, respectively. On the basis of Pearson's correlation analysis, many organic solutes and 6-gingerol, the main active substance of ginger, exhibited significant correlations with water distribution as determined by NMR T2 relaxation, suggesting that the organic solute differences may impact water distribution. Our work demonstrates that low-field NMR relaxometry provides useful information about water dynamics in different ginger cultivars as affected by the presence of different organic solutes.

  7. 13C Solid State Nuclear Magnetic Resonance and µ-Raman Spectroscopic Characterization of Sicilian Amber.

    Science.gov (United States)

    Barone, Germana; Capitani, Donatella; Mazzoleni, Paolo; Proietti, Noemi; Raneri, Simona; Longobardo, Ugo; Di Tullio, Valeria

    2016-08-01

    (13)C cross-polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) and µ-Raman spectroscopy were applied to characterize Sicilian amber samples. The main goal of this work was to supply a complete study of simetite, highlighting discriminating criteria useful to distinguish Sicilian amber from fossil resins from other regions and laying the foundations for building a spectroscopic database of Sicilian amber. With this aim, a private collection of unrefined simetite samples and fossil resins from the Baltic region and Dominican Republic was analyzed. Overall, the obtained spectra permitted simetite to be distinguished from the other resins. In addition, principal component analysis (PCA) was applied to the spectroscopic data, allowing the clustering of simetite samples with respect to the Baltic and Dominican samples and to group the simetite samples in two sets, depending on their maturity. Finally, the analysis of loadings allowed for a better understanding of the spectral features that mainly influenced the discriminating characteristics of the investigated ambers.

  8. Disordered nuclear pasta, magnetic field decay, and crust cooling in neutron stars

    CERN Document Server

    Horowitz, C J; Briggs, C M; Caplan, M E; Cumming, A; Schneider, A S

    2014-01-01

    Nuclear pasta, with non-spherical shapes, is expected near the base of the crust in neutron stars. Large scale molecular dynamics simulations of pasta show long lived topological defects that could increase electron scattering and reduce both the thermal and electrical conductivities. We model a possible low conductivity pasta layer by increasing an impurity parameter Q_{imp}. Predictions of light curves for the low mass X-ray binary MXB 1659-29, assuming a large Q_{imp}, find continued late time cooling that is consistent with Chandra observations. The electrical and thermal conductivities are likely related. Therefore observations of late time crust cooling can provide insight on the electrical conductivity and the possible decay of neutron star magnetic fields (assuming these are supported by currents in the crust).

  9. The fragile-to-strong dynamic crossover transition in confined water: nuclear magnetic resonance results.

    Science.gov (United States)

    Mallamace, F; Broccio, M; Corsaro, C; Faraone, A; Wanderlingh, U; Liu, L; Mou, C-Y; Chen, S H

    2006-04-28

    By means of a nuclear magnetic resonance experiment, we give evidence of the existence of a fragile-to-strong dynamic crossover transition (FST) in confined water at a temperature T(L)=223+/-2 K. We have studied the dynamics of water contained in 1D cylindrical nanoporous matrices (MCM-41-S) in the temperature range 190-280 K, where experiments on bulk water were so far hampered by crystallization. The FST is clearly inferred from the T dependence of the inverse of the self-diffusion coefficient of water (1D) as a crossover point from a non-Arrhenius to an Arrhenius behavior. The combination of the measured self-diffusion coefficient D and the average translational relaxation time tau(T), as measured by neutron scattering, shows the predicted breakdown of Stokes-Einstein relation in deeply supercooled water.

  10. Solid state nuclear magnetic resonance studies of cross polarization from quadrupolar nuclei

    Energy Technology Data Exchange (ETDEWEB)

    De Paul, Susan M. [Univ. of California, Berkeley, CA (United States)

    1997-08-01

    The development of solid-state Nuclear Magnetic Resonance (NMR) has, to a large extent, focused on using spin-1/2 nuclei as probes to investigate molecular structure and dynamics. For such nuclei, the technique of cross polarization is well-established as a method for sensitivity enhancement. However, over two-thirds of the nuclei in the periodic table have a spin-quantum number greater than one-half and are known as quadrupolar nuclei. Such nuclei are fundamental constituents of many inorganic materials including minerals, zeolites, glasses, and gels. It is, therefore, of interest to explore the extent to which polarization can be transferred from quadrupolar nuclei. In this dissertation, solid-state NMR experiments involving cross polarization from quadrupolar nuclei to spin-1/2 nuclei under magic-angle spinning (MAS) conditions are investigated in detail.

  11. Observation of intermolecular double-quantum coherence signal dips in nuclear magnetic resonance

    Institute of Scientific and Technical Information of China (English)

    Shen Gui-Ping; Cai Cong-Bo; Cai Shu-Hui; Chen Zhong

    2011-01-01

    The correlated spectroscopy revamped by asymmetric Z-gradient echo detection (CRAZED) sequence is modified to investigate intermolecular double-quantum coherence nuclear magnetic resonance signal dips in highly polarized spin systems.It is found that the occurrence of intermolecular double-quantum coherence signal dips is related to sample geometry,field inhomogeneity and dipolar correlation distance.If the field inhomogeneity is refocused,the signal dip occurs at a fixed position whenever the dipolar correlation distance approaches the sample dimension.However,the position is shifted when the field inhomogeneity exists.Experiments and simulations are performed to validate our theoretic analysis.These signal features may offer a unique way to investigate porous structures and may find applications in biomedicine and material science.

  12. Investigation on Mechanisms of Polymer Enhanced Oil Recovery by Nuclear Magnetic Resonance and Microscopic Theoretical Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ji-Cheng; SONG Kao-Ping; LIU Li; YANG Er-Long

    2008-01-01

    Polymer flooding is an efficient technique to enhance oil recovery over water flooding.There are lots of discussions regarding the mechanisms for polymer flooding enhancing oil recovery. The main focus is whether polymer flooding can increase sweep effciency alone,or can increase both of sweep efficiency and displacement efficiency.We present a study on this problem.Oil displacement experiments on 4 natural cores show that polymer flooding can increase oil recovery efficiency by more than 12% over water.Moreover,photos are taken by the nuclear magnetic resonance (NMR) method both after water flooding and after polymer flooding,which show remaining oil saturation distribution at the middle cross section and the central longitudinal section.Analyses of these photos demonstrate that polymer flooding can increase both sweep efficiency and displacement efficiency.

  13. Chirality-sensitive nuclear magnetic resonance effects induced by indirect spin-spin coupling

    Science.gov (United States)

    Garbacz, P.; Buckingham, A. D.

    2016-11-01

    It is predicted that, for two spin-1/2 nuclei coupled by indirect spin-spin coupling in a chiral molecule, chirality-sensitive induced electric polarization can be observed at the frequencies equal to the sum and difference between the spin resonance frequencies. Also, an electric field oscillating at the difference frequency can induce spin coherences which allow the direct discrimination between enantiomers by nuclear magnetic resonance. The dominant contribution to the magnitude of these expected chiral effects is proportional to the permanent electric dipole moment and to the antisymmetric part of the indirect spin-spin coupling tensor of the chiral molecule. Promising compounds for experimental tests of the predictions are derivatives of 1,3-difluorocyclopropene.

  14. High Resolution Nuclear Magnetic Resonance: From Chemical Structure to Food Authenticity

    Energy Technology Data Exchange (ETDEWEB)

    Mannina, L.; Segre, A.

    2002-07-01

    Nuclear magnetic resonance (NMR) is a powerful technique able to give us a relevant contribution in food analysis. In this review, some practical aspects of this technique (sample preparation, acquisition time, relaxation delay, etc) as well as some methods of spectral assignment of the spectra (2D and 1D selective technique) are reported. Some examples of NMR quantitative analyses are reported. In particular, the results relative to the NMR study of olive oils are discussed, among these: the comparison between conventional analyses and the NMR analysis in the olive oil characterization; the NMR determination of minor components such as squalene, cyclo-arthenol and chlorophyll in olive oil; the panel test and its relationship with NMR data: the geographical characterization of olive oils. (Author) 26 refs.

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

    Science.gov (United States)

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

    2009-01-01

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

  16. Nuclear magnetic resonance measurements of velocity distributions in an ultrasonically vibrated granular bed.

    Science.gov (United States)

    Huntley, J M; Tarvaz, T; Mantle, M D; Sederman, A J; Gladden, L F; Sheikh, N A; Wildman, R D

    2014-05-13

    We report the results of nuclear magnetic resonance imaging experiments on granular beds of mustard grains fluidized by vertical vibration at ultrasonic frequencies. The variation of both granular temperature and packing fraction with height was measured within the three-dimensional cell for a range of vibration frequencies, amplitudes and numbers of grains. Small increases in vibration frequency were found--contrary to the predictions of classical 'hard-sphere' expressions for the energy flux through a vibrating boundary--to result in dramatic reductions in granular temperature. Numerical simulations of the grain-wall interactions, using experimentally determined Hertzian contact stiffness coefficients, showed that energy flux drops significantly as the vibration period approaches the grain-wall contact time. The experiments thus demonstrate the need for new models for 'soft-sphere' boundary conditions at ultrasonic frequencies.

  17. NMR (Nuclear Magnetic Resonance) and macromolecular migration in a melt or in concentrated solutions

    Science.gov (United States)

    Addad, J. P. C.

    1983-01-01

    The purpose of this paper is to analyze the migration process of long polymer molecules in a melt or in concentrated solutions as it may be observed from the dynamics of the transverse magnetization of nuclear spins linked to these chains. The low frequency viscoelastic relaxation of polymer systems is known to be mainly controlled by the mechanism of dissociation of topological constraints excited on chains and which are called entanglements. This mechanism exhibits a strong dependence upon the chain molecular weight. These topological constraints also govern the diffusion process of polymer chains. So, the accurate description of the diffusion motion of a chain may be a convenient way to characterize disentanglement processes necessarily involved in any model proposed to explain viscoelastic effects.

  18. Nuclear magnetic resonance (NMR) imaging of Arnold-Chiari type I malformation with hydromyelia

    Energy Technology Data Exchange (ETDEWEB)

    DeLaPaz, R.L.; Brady, T.J.; Buonanno, F.S.; New, P.F.; Kistler, J.P.; McGinnis, B.D.; Pykett, I.L.; Taveras, J.M.

    1983-02-01

    Saturation recovery nuclear magnetic resonance (NMR) images and metrizamide computed tomography (CT) scans were obtained in an adult patient with a clinical history suggestive of syringomyelia. Both NMR and CT studies showed low lying cerebellar tonsils. The CT study demonstrated central cavitation of the spinal cord from the midthoracic to midcervical levels but could not exclude an intramedullary soft tissue mass at the cervico-medullary junction. The NMR images in transverse, coronal, and sagittal planes demonstrated extension of an enlarged central spinal cord cerebrospinal fluid space to the cervico-medullary junction. This was felt to be strong evidence for exclusion of an intramedullary soft tissue mass and in favor of a diagnosis of Arnold-Chiari Type I malformation with hydromyelia. The noninvasive nature of spinal cord and cervico-medullary junction evaluation with NMR is emphasized.

  19. The fragile-to-strong dynamic crossover transition in confined water: nuclear magnetic resonance results

    Science.gov (United States)

    Mallamace, F.; Broccio, M.; Corsaro, C.; Faraone, A.; Wanderlingh, U.; Liu, L.; Mou, C.-Y.; Chen, S. H.

    2006-04-01

    By means of a nuclear magnetic resonance experiment, we give evidence of the existence of a fragile-to-strong dynamic crossover transition (FST) in confined water at a temperature TL=223±2K. We have studied the dynamics of water contained in 1D cylindrical nanoporous matrices (MCM-41-S) in the temperature range 190-280K, where experiments on bulk water were so far hampered by crystallization. The FST is clearly inferred from the T dependence of the inverse of the self-diffusion coefficient of water (1/D) as a crossover point from a non-Arrhenius to an Arrhenius behavior. The combination of the measured self-diffusion coefficient D and the average translational relaxation time ⟨τT⟩, as measured by neutron scattering, shows the predicted breakdown of Stokes-Einstein relation in deeply supercooled water.

  20. Structure, Dynamics, and Assembly of Filamentous Bacteriophages by Nuclear Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Opella, Stanley J.; Zeri, Ana Carolina; Park, Sang Ho

    2008-05-01

    Filamentous bacteriophages serve as model systems for the development and implementation of spectroscopic methods suitable for biological supramolecular assemblies. Not only are their coat proteins small and readily prepared in the laboratory, but they also have two primary roles as membrane proteins and as the principal structural element of the virus particles. As a bacterial system, they are readily labeled with stable isotopes, and this has opened possibilities for the many nuclear magnetic resonance (NMR) studies described in this review. In particular, solid-state NMR of aligned samples has been used to determine the three-dimensional structures of both the membrane-bound forms of coat proteins in phospholipid bilayers and structural forms in virus particles, which has led to an analysis of the assembly mechanism for virus particles as they are extruded through the cell membrane.

  1. Application of Nuclear Magnetic Resonance and Hybrid Methods to Structure Determination of Complex Systems.

    Science.gov (United States)

    Prischi, Filippo; Pastore, Annalisa

    2016-01-01

    The current main challenge of Structural Biology is to undertake the structure determination of increasingly complex systems in the attempt to better understand their biological function. As systems become more challenging, however, there is an increasing demand for the parallel use of more than one independent technique to allow pushing the frontiers of structure determination and, at the same time, obtaining independent structural validation. The combination of different Structural Biology methods has been named hybrid approaches. The aim of this review is to critically discuss the most recent examples and new developments that have allowed structure determination or experimentally-based modelling of various molecular complexes selecting them among those that combine the use of nuclear magnetic resonance and small angle scattering techniques. We provide a selective but focused account of some of the most exciting recent approaches and discuss their possible further developments.

  2. Characterization of yogurts made with milk solids nonfat by rheological behavior and nuclear magnetic resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Hai-Yan Yu

    2016-10-01

    Full Text Available The effect of adding milk solids nonfat (MSNF on the physical properties and microstructure of yogurts was investigated. The physical properties of fat free yogurt, fat free with MSNF yogurt, whole fat yogurt, and whole fat with MSNF yogurt were analyzed using shear viscosity, viscoelasticity, and texture analysis. The two yogurts with MSNF had higher consistency coefficient (K, storage modulus (G′, yield stress, and hardness. To gain insight into the multiphase system, nuclear magnetic resonance (NMR and brightfield microscope images were acquired. The addition of MSNF significantly modified NMR relaxation time; T1 values were reduced significantly. Brightfield microscope images showed that the size of the protein network of the two yogurts with MSNF added was greater than that of the two yogurts without MSNF added. The microstructural information supported the physical information. The results showed that the increase in MSNF contributed positively to strengthening the physical/mechanical properties of yogurt.

  3. Information flow and protein dynamics: the interplay between nuclear magnetic resonance spectroscopy and molecular dynamics simulations

    Science.gov (United States)

    Pastor, Nina; Amero, Carlos

    2015-01-01

    Proteins participate in information pathways in cells, both as links in the chain of signals, and as the ultimate effectors. Upon ligand binding, proteins undergo conformation and motion changes, which can be sensed by the following link in the chain of information. Nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics (MD) simulations represent powerful tools for examining the time-dependent function of biological molecules. The recent advances in NMR and the availability of faster computers have opened the door to more detailed analyses of structure, dynamics, and interactions. Here we briefly describe the recent applications that allow NMR spectroscopy and MD simulations to offer unique insight into the basic motions that underlie information transfer within and between cells. PMID:25999971

  4. 77Se nuclear magnetic resonance of topological insulator Bi2Se3

    Science.gov (United States)

    Georgieva, Nataliya M.; Rybicki, Damian; Guehne, Robin; Williams, Grant V. M.; Chong, Shen V.; Kadowaki, Kazuo; Garate, Ion; Haase, Jürgen

    2016-05-01

    Topological insulators constitute a new class of materials with an energy gap in the bulk and peculiar metallic states on the surface. We report on new features resulting from the bulk electronic structure, based on a comprehensive nuclear magnetic resonance (NMR) study of 77Se on Bi2Se3 and Cu0.15Bi2Se3 single crystals. First, we find two resonance lines and show that they originate from the two inequivalent Se lattice sites. Second, we observe unusual field-independent linewidths and attribute them to an unexpectedly strong internuclear coupling mediated by bulk electrons. In order to support this interpretation, we present a model calculation of the indirect internuclear coupling and show that the Bloembergen-Rowland coupling is much stronger than the Ruderman-Kittel-Kasuya-Yosida coupling. Our results call for a revision of earlier NMR studies and add information concerning the bulk electronic properties.

  5. Information Flow and Protein Dynamics: the Interplay Between Nuclear Magnetic Resonance Spectroscopy and Molecular Dynamics Simulations

    Directory of Open Access Journals (Sweden)

    Nina ePastor

    2015-05-01

    Full Text Available Proteins participate in information pathways in cells, both as links in the chain of signals, and as the ultimate effectors. Upon ligand binding, proteins undergo conformation and motion changes, which can be sensed by the following link in the chain of information. Nuclear magnetic resonance (NMR spectroscopy and molecular dynamics (MD simulations represent powerful tools for examining the time-dependent function of biological molecules. The recent advances in NMR and the availability of faster computers have opened the door to more detailed analyses of structure, dynamics and interactions. Here we briefly describe the recent applications that allow NMR spectroscopy and MD simulations to offer unique insight into the basic motions that underlie information transfer within and between cells.

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

    Science.gov (United States)

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

    2012-10-01

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

  7. Interaction of Divalent Metal Ions with the Adenosine Triphosphate Measured Using Nuclear Magnetic Resonance

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The interaction of adenosine triphosphate with divalent metal ions is important in biochemical functions. The effects of pH and metal ions Mg2+, Ca2+, Zn2+, Mn2+, and Co2+ on the chemical shift of the phosphate group of ATP have been studied using Nuclear Magnetic Resonance. The chemical shift of the β-phosphate of ATP is the most sensitive to pH. Ca2+ and Mg2+ bind with the α- and β-phosphate groups of ATP. Zn2+ binds to the adenosine ring hydrogen as well as to phosphate. The paramagnetic ions Mn2+ and Co2+ do not cause chemical shifts of the phosphate or proton peak. Mn2+ and Co2+ broaden the resonance peak only.

  8. Nuclear Magnetic Resonance Identification of New Sulfonic Acid Metabolites of Chloroacetanilide Herbicides

    Science.gov (United States)

    Morton, M.D.; Walters, F.H.; Aga, D.S.; Thurman, E.M.; Larive, C.K.

    1997-01-01

    The detection of the sulfonic acid metabolites of the chloroacetanilide herbicides acetochlor, alachlor, butachlor, propachlor, and, more recently, metolachlor in surface and ground water suggests that a common mechanism for dechlorination exists via the glutathione conjugation pathway. The identification of these herbicides and their metabolites is important due to growing public awareness and concern about pesticide levels in drinking water. Although these herbicides are regulated, little is known about the fate of their metabolites in soil. The sulfonic acid metabolites were synthesized by reaction of the parent compounds with an excess of sodium sulfite. Acetochlor, alachlor, butachlor, metolachlor, and propachlor and their sulfonic acid metabolites were studied by nuclear magnetic resonance spectroscopy and fast atom bombardment mass spectrometry. This paper provides a direct method for the preparation and characterization of these compounds that will be useful in the analysis and study of chloracetanilide herbicides and their metabolites.

  9. A reactor for high-throughput high-pressure nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Beach, N. J.; Knapp, S. M. M.; Landis, C. R.

    2015-10-01

    The design of a reactor for operando nuclear magnetic resonance (NMR) monitoring of high-pressure gas-liquid reactions is described. The Wisconsin High Pressure NMR Reactor (WiHP-NMRR) design comprises four modules: a sapphire NMR tube with titanium tube holder rated for pressures as high as 1000 psig (68 atm) and temperatures ranging from -90 to 90 °C, a gas circulation system that maintains equilibrium concentrations of dissolved gases during gas-consuming or gas-releasing reactions, a liquid injection apparatus that is capable of adding measured amounts of solutions to the reactor under high pressure conditions, and a rapid wash system that enables the reactor to be cleaned without removal from the NMR instrument. The WiHP-NMRR is compatible with commercial 10 mm NMR probes. Reactions performed in the WiHP-NMRR yield high quality, information-rich, and multinuclear NMR data over the entire reaction time course with rapid experimental turnaround.

  10. Developments in quantum information processing by nuclear magnetic resonance: Use of quadrupolar and dipolar couplings

    Indian Academy of Sciences (India)

    Anil Kumar; K V Ramanathan; T S Mahesh; Neeraj Sinha; K V R Murali

    2002-08-01

    Use of dipolar and quadrupolar couplings for quantum information processing (QIP) by nuclear magnetic resonance (NMR) is described. In these cases, instead of the individual spins being qubits, the 2 energy levels of the spin-system can be treated as an -qubit system. It is demonstrated that QIP in such systems can be carried out using transition-selective pulses, in CH3CN, 13CH3CN, 7Li ( = 3/2) and 133Cs ( = 7/2), oriented in liquid crystals yielding 2 and 3 qubit systems. Creation of pseudopure states, implementation of logic gates and arithmetic operations (half-adder and subtractor) have been carried out in these systems using transition-selective pulses.

  11. Nuclear magnetic resonance study of epoxy- based polymer-dispersed liquid crystal droplets

    CERN Document Server

    Han, J W

    1998-01-01

    In this work, polymer-dispersed liquid crystals (PDLC) samples were prepared and studied by nuclear magnetic resonance. Proton NMR spectra and spin-lattice relaxations of 4-cyano-4'-pentylbiphenyl(5CB) and p-methoxybenzylidene-p-n-butylaniline (MBBA) liquid crystals confined in microdroplets were measured. The experimental results were compared with those of the liquid crystals in the pores of silica-gels and with those of the mixing components. The experimental results indicated that the nematic ordering in the microdroplets differed markedly from that observed in bulk nematic crystals. In addition, we examined spin-lattice relaxation mechanisms. The proton spin-lattice relaxation mechanisms in bulk nematic liquid crystals are well established. However, when nematic liquid crystals are confined in microdroplets, the relaxation mechanisms are expected to be affected. We examined possible relaxation mechanisms to explain the observed increase in the spin-lattice relaxation rate of liquid crystals confined in m...

  12. Nonideal rotations in nuclear magnetic resonance: Estimation of coherence transfer leakage

    Energy Technology Data Exchange (ETDEWEB)

    Jerschow, Alexej [Materials Sciences Division, 11-D62, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); Chemistry Department, D62 Hildebrand, University of California at Berkeley, Berkeley, California 94720 (United States)

    2000-07-15

    When spherical tensors are rotated by certain angles, coherence transfer selection rules may apply. For example, a {pi} rotation cleanly inverts the coherence order. A {pi}/2 rotation of a T{sub 0}{sup 1} tensor creates only T{sub {+-}}{sub 1}{sup 1} tensors. In this work estimations are given for the coherence transfer leakage under the action of rotations with small errors in the rotation angle or axis. Although the theory is stated with particular applications to NMR (nuclear magnetic resonance) in mind it is equally applicable wherever nonideal rotations of spherical tensors are considered (e.g., quantum computing and relaxation theory). In NMR it is useful for the estimation of coherence transfer leakage, especially in pulse sequences with many n{pi} pulses. The results are also applicable to spinors and half-integer representations of the rotation group. (c) 2000 American Institute of Physics.

  13. Material degradation of liquid organic semiconductors analyzed by nuclear magnetic resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Tatsuya Fukushima

    2015-08-01

    Full Text Available Liquid organic light-emitting diodes (liquid OLEDs are unique devices consisting only of liquid organic semiconductors in the active layer, and the device performances have been investigated recently. However, the device degradation, especially, the origin has been unknown. In this study, we show that material degradation occurs in liquid OLEDs, whose active layer is composed of carbazole with an ethylene glycol chain. Nuclear magnetic resonance (NMR experiments clearly exhibit that the dimerization reaction of carbazole moiety occurs in the liquid OLEDs during driving the devices. In contrast, cleavages of the ethylene glycol chain are not detected within experimental error. The dimerization reaction is considered to be related to the device degradation.

  14. {sup 23}Na nuclear magnetic resonance study of the structure and dynamic of natrolite

    Energy Technology Data Exchange (ETDEWEB)

    Paczwa, Mateusz; Olszewski, Marcin; Sergeev, Nikolaj [Szczecin Univ. (Poland). Inst. of Physics; Sapiga, Aleksej A.; Sapiga, Aleksej V. [Taurida National V.I. Vernadsky Univ., Simferopol, Crimea (Ukraine)

    2015-07-01

    The temperature dependences of nuclear magnetic resonance (NMR) and magic angle spinning (MAS) NMR spectra of {sup 23}Na nuclei in natrolite (Na{sub 2}Al{sub 2}Si{sub 3}O{sub 10} . 2H{sub 2}O) have been studied. The temperature dependences of the spin-lattice relaxation times T{sub 1} in natrolite have also been studied. It has been shown that the spin-lattice relaxation of the {sup 23}Na is governed by the electric quadrupole interaction with the crystal electric field gradients modulated by translational motion of H{sub 2}O molecules in the natrolite pores. The dipolar interactions with paramagnetic impurities become significant as a relaxation mechanism of the {sup 23}Na nuclei only at low temperature (<270 K).

  15. Nuclear magnetic resonance in contemporary art: the case of "Moon Surface" by Turcato

    Science.gov (United States)

    Proietti, Noemi; Di Tullio, Valeria; Capitani, Donatella; Tomassini, Roberta; Guiso, Marcella

    2013-12-01

    Nuclear Magnetic Resonance (NMR) methodologies were applied to characterize the constitutive materials and the state of degradation of a contemporary painting. The investigation was mandatory to plan a suitable restoration. Noninvasive, portable NMR allowed the detection of degraded regions of the painting based on the measurement of longitudinal relaxation time. A few samples were investigated by high resolution solid state NMR and NMR in solution, which allowed us to identify the polyurethane constituting the artefact, to investigate the microstructure in detail, and to assess that the degradation process mostly affected the ethylene units used to cap the polypropylene oxide polymeric chain. As a matter of fact, a shortening of longitudinal relaxation time was accompanied by a degradation of ethylene units. The degradation of the inorganic loading was investigated by 27Al MAS, which evidenced the absence of penta-coordinated aluminum in degraded samples.

  16. Nuclear magnetic resonance investigation of erythrocyte membranes in chronic myeloproliferative disorders.

    Science.gov (United States)

    Morariu, V V; Petrov, L

    1986-07-01

    The temperature dependence of the apparent water diffusional exchange through erythrocyte membranes in cases of policitemia vera, chronic granulocytic leukemia and primary myelofibrosis was measured by using a nuclear magnetic resonance method in the presence of Mn2+. The thermal transition shifted to lower temperatures in all cases, regardless of the stage of the disease, suggesting a structural alteration of the membrane. The shift of transition indirectly suggests a lower penetration of the erythrocytes by Mn2+. The water exchange time at 37 degrees C also increased, mainly in the blast crisis; it seems to have a prognostic value of some clinical interest. No simple correlation of the water exchange and the following clinical investigations was observed: the white count, the percentage of promyelocites and myeloblasts, the sedimentation rate of blood, the osmotic fragility of erythrocytes, the total concentration of proteins, albumin and immunoglobulins, respectively, in plasma.

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

    Science.gov (United States)

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

    2002-01-01

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

  18. Evaluation of poly(vinylpyrrolidone) and collagen by Low Field Nuclear Magnetic Resonance Spectroscopy; Avaliacao da polivinilpirrolidona e do colageno por ressonancia magnetica nuclear de baixo campo

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Paula de M.; Tavares, Maria I.B. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano]. E-mail: pmcosta@ima.ufrj.br

    2005-07-01

    Blends of natural and synthetic polymers represent a new class of materials with better mechanical properties and biocompatibility than those of the single components. Collagen and poly(vinylpyrrolidone) are well known for their important biological properties. The blending of collagen with poly(vinylpyrrolidone) makes it possible to obtain new materials in which strong interactions between the synthetic and biological components occur. Do to the excellent biocompatibility of these polymers, this blend has been much studied intending biomedical applications. And a one technique that can provide important information on molecular mobility, compatibility and even evaluate the interactions that can occur with these polymers is the Low Field Nuclear Magnetic Resonance Spectroscopy. Thus, the purpose of this work is to evaluate collagen and poly(vinylpyrrolidone) by Low Field Nuclear Magnetic Resonance Spectroscopy. From the values of relaxation times obtained, we can conclude that these materials have different interactions, and different mobility domains, confirming the heterogeneity and complexity of these materials. (author)

  19. Quantification of aquifer properties with surface nuclear magnetic resonance in the Platte River valley, central Nebraska, using a novel inversion method

    Science.gov (United States)

    Irons, Trevor P.; Hobza, Christopher M.; Steele, Gregory V.; Abraham, Jared D.; Cannia, James C.; Woodward, Duane D.

    2012-01-01

    Surface nuclear magnetic resonance, a noninvasive geophysical method, measures a signal directly related to the amount of water in the subsurface. This allows for low-cost quantitative estimates of hydraulic parameters. In practice, however, additional factors influence the signal, complicating interpretation. The U.S. Geological Survey, in cooperation with the Central Platte Natural Resources District, evaluated whether hydraulic parameters derived from surface nuclear magnetic resonance data could provide valuable input into groundwater models used for evaluating water-management practices. Two calibration sites in Dawson County, Nebraska, were chosen based on previous detailed hydrogeologic and geophysical investigations. At both sites, surface nuclear magnetic resonance data were collected, and derived parameters were compared with results from four constant-discharge aquifer tests previously conducted at those same sites. Additionally, borehole electromagnetic-induction flowmeter data were analyzed as a less-expensive surrogate for traditional aquifer tests. Building on recent work, a novel surface nuclear magnetic resonance modeling and inversion method was developed that incorporates electrical conductivity and effects due to magnetic-field inhomogeneities, both of which can have a substantial impact on the data. After comparing surface nuclear magnetic resonance inversions at the two calibration sites, the nuclear magnetic-resonance-derived parameters were compared with previously performed aquifer tests in the Central Platte Natural Resources District. This comparison served as a blind test for the developed method. The nuclear magnetic-resonance-derived aquifer parameters were in agreement with results of aquifer tests where the environmental noise allowed data collection and the aquifer test zones overlapped with the surface nuclear magnetic resonance testing. In some cases, the previously performed aquifer tests were not designed fully to characterize

  20. High Resolution Nuclear Magnetic Resonance Studies of the Active Site of Chymotrypsin. I. The Hydrogen Bonded Protons of the “Charge Relay” System

    NARCIS (Netherlands)

    Robillard, G.; Shulman, R.G.

    1974-01-01

    High resolution proton nuclear magnetic resonance has been used to observe protons at the active site of chymotrypsin Aδ and at the same region of chymotrypsinogen A. A single resonance with the intensity of one proton is located in the low field region of the nuclear magnetic resonance spectrum. Th

  1. Discriminating poststroke depression from stroke by nuclear magnetic resonance spectroscopy-based metabonomic analysis

    Directory of Open Access Journals (Sweden)

    Xiao J

    2016-08-01

    Full Text Available Jianqi Xiao,1,* Jie Zhang,2,* Dan Sun,3,* Lin Wang,4,* Lijun Yu,5 Hongjing Wu,5 Dan Wang,5 Xuerong Qiu5 1Department of Neurosurgery, The First Hospital of Qiqihar City, Qiqihar, 2Department of Internal Medicine, Central Hospital of Jiamusi City, Jiamusi, 3Department of Geriatrics, General Hospital of Daqing Oil Field, Daqing, 4Department of Nursing, 5Department of Neurology, The First Hospital of Qiqihar City, Qiqihar, Heilongjiang, People’s Republic of China *These authors contributed equally to this work Abstract: Poststroke depression (PSD, the most common psychiatric disease that stroke survivors face, is estimated to affect ~30% of poststroke patients. However, there are still no objective methods to diagnose PSD. In this study, to explore the differential metabolites in the urine of PSD subjects and to identify a potential biomarker panel for PSD diagnosis, the nuclear magnetic resonance-based metabonomic method was applied. Ten differential metabolites responsible for discriminating PSD subjects from healthy control (HC and stroke subjects were found, and five of these metabolites were identified as potential biomarkers (lactate, α-hydroxybutyrate, phenylalanine, formate, and arabinitol. The panel consisting of these five metabolites provided excellent performance in discriminating PSD subjects from HC and stroke subjects, achieving an area under the receiver operating characteristic curve of 0.946 in the training set (43 HC, 45 stroke, and 62 PSD subjects. Moreover, this panel could classify the blinded samples from the test set (31 HC, 33 stroke, and 32 PSD subjects with an area under the curve of 0.946. These results laid a foundation for the future development of urine-based objective methods for PSD diagnosis and investigation of PSD pathogenesis. Keywords: poststroke depression, PSD, stroke, nuclear magnetic resonance, NMR, metabonomic

  2. Identification of fucans from four species of sea cucumber by high temperature 1H NMR

    Science.gov (United States)

    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.

  3. Effect of Magnetic Field on the Phase Transition from Nuclear Matter to Quark Matter during Proto-Neutron Star Evolution

    CERN Document Server

    Gupta, V K; Singh, S; Anand, J D; Gupta, Asha

    2002-01-01

    We have studied phase transition from hadron matter to quark matter in the presence of high magnetic fields incorporating the trapped electron neutrinos at finite temperatures. We have used the density dependent quark mass (DDQM) model for the quark phase while the hadron phase is treated in the frame-work of relativistic mean field theory. It is seen that the nuclear energy at phase transition decreases with both magnetic field and temperature. A brief discussion of the effect of magnetic field in supernova explosions and proto-neutron star evolution is given.

  4. Advances and applications of dynamic-angle spinning nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Baltisberger, J.H.

    1993-06-01

    This dissertation describes nuclear magnetic resonance experiments and theory which have been developed to study quadrupolar nuclei (those nuclei with spin greater than one-half) in the solid state. Primarily, the technique of dynamic-angle spinning (DAS) is extensively reviewed and expanded upon in this thesis. Specifically, the improvement in both the resolution (two-dimensional pure-absorptive phase methods and DAS angle choice) and sensitivity (pulse-sequence development), along with effective spinning speed enhancement (again through choice of DAS conditions or alternative multiple pulse schemes) of dynamic-angle spinning experiment was realized with both theory and experimental examples. The application of DAS to new types of nuclei (specifically the {sup 87}Rb and {sup 85}Rb nuclear spins) and materials (specifically amorphous solids) has also greatly expanded the possibilities of the use of DAS to study a larger range of materials. This dissertation is meant to demonstrate both recent advances and applications of the DAS technique, and by no means represents a comprehensive study of any particular chemical problem.

  5. A 1H magnetic resonance spectroscopy study on dorsolateral prefrontal cortex in patients with bipolar mania%双相障碍躁狂发作患者背外侧前额叶皮质氢质子磁共振波谱研究

    Institute of Scientific and Technical Information of China (English)

    马海波; 李国海; 宁厚梅; 王冬青; 李一云

    2013-01-01

    Objective:To measure the metabolic features of the dorsolateral prefrontal cortex in patients with bipolar mania by using proton magnetic resonance spectroscopy(1H-MRS).Methods:1H-MRS was performed on dorsolateral prefrontal cortex in 20 unmediated patients with bipolar mania and 20 healthy controls.The levels of N-acetylaspartate(NAA),glutamate/glutamine(Glx) and creatine(Cr) were measured,and ratios of NAA/Cr and Glx/Cr were calculated.The 1H-MRS metabolites levels in dorsolateral prefrontal cortex between patients and healthy controls were compared.The associations between the metabolite levels and the course of disease or the Beth Rafaelsen Mania Scale (BRMS)score were examined.Results:Bipolar mania patients had significantly lower NAA/Cr ratios in bilateral dorsolateral prefrontal cortex than healthy controls,The Glx/Cr ratios from left dorsolateral prefrontal cortex were significantly higher in patients than healthy controis.There were no significant differences in Glx/Cr ratios in right dorsolateral prefrontal cortex between the two groups (P > 0.05).There were no significant relationships between all the metabolic indexes and the course of disease or the BRMS score(P > 0.05).Conclusion:There might be nerve biochemical dysfunction in the dorsolateral prefrontal cortex of patients with bipolar mania.%目的:研究双相障碍躁狂发作患者背外侧前额叶皮质氢质子磁共振波谱(1H magnetic resonance spectroscoPy,1 H-MRS)的特点.方法:选择20例双相躁狂发作未服药患者(双相躁狂组)和20例健康志愿者(正常对照组),对其背外侧前额叶皮质行1 H-MRS扫描,检测N-乙酰天门冬氨酸(NAA)、谷氨酸复合物(Glx)和肌酸(Cr)3种代谢物含量.比较两组代谢物含量,计算NAA/Cr、Glx/Cr值,并对代谢指标与病程及Bech-Rafaelsen躁狂最表(BRMS)评分的相关性进行分析.结果:双相躁狂组左侧和右侧背外侧前额叶皮质NAA/Cr值明显低于正常对照组.双相躁狂组左侧背外

  6. Use of relativistic hadronic mechanics for the exact representation of nuclear magnetic moments and the prediction of new recycling of nuclear waste

    CERN Document Server

    Santilli, R M

    1997-01-01

    We present a new realization of relativistic hadronic me- chanics and its underlying iso-Poincar'e symmetry specifically constructed for nuclear physics which: 1) permits the representation of nucleons as ex- tended, nonspherical and deformable charge distributions with alterable mag- netic moments yet conventional angular momentum and spin; 2) results to be a nonunitary ``completion'' of relativistic quantum mechanics much along the EPR argument; yet 3) is axiom-preserving, thus preserves conventional quantum laws and the axioms of the special relativity. We show that the proposed new formalism permits the apparently first exact representation of the total magnetic moments of new-body nuclei under conventional physical laws. We then point out that, if experimentally confirmed the alterability of the intrinsic characteristics of nucleons would imply new forms of recycling nuclear waste by the nuclear power plants in their own site, thus avoiding its transportation and storage in a (yet unidentified) dumping a...

  7. Anomalous magnetic fluctuations in superconducting Sr2RuO4 revealed by 101Ru nuclear spin-spin relaxation

    Science.gov (United States)

    Manago, Masahiro; Yamanaka, Takayoshi; Ishida, Kenji; Mao, Zhiqiang; Maeno, Yoshiteru

    2016-10-01

    We carried out 101Ru nuclear quadrupole resonance (NQR) measurement on superconducting (SC) Sr2RuO4 under zero magnetic field (H =0 ) and found that the nuclear spin-spin relaxation rate 1 /T2 is enhanced in the SC state. The 1 /T2 measurement in the SC state under H =0 is effective for detecting slow magnetic fluctuations parallel to the quantized axis of the nuclear spin. Our results indicate that low-energy magnetic fluctuations perpendicular to the RuO2 plane emerge when the superconductivity sets in, which is consistent with the previous 17O-NQR result that the nuclear spin-lattice relaxation rate 1 /T1 of the in-plane O site exhibits anomalous behavior in the SC state. The enhancement of the magnetic fluctuations in the SC state is unusual and suggests that the fluctuations are related to the unconventional SC pairing. We suggest that this phenomenon is a consequence of the spin degrees of freedom of the spin-triplet pairing.

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

    OpenAIRE

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

    1983-01-01

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

  9. The phase diagram and the magnetic structure of nuclear spins in elemental copper below 60 nK

    DEFF Research Database (Denmark)

    Siemensmeyer, K.; Steiner, M.; Weinfurther, H.;

    1992-01-01

    The phase diagram for nuclear magnetic order is elemental copper and the corresponding ordering vectors were investigated by neutron diffraction at nanokelvin temperatures. The intermediate phase is characterized by an ordering vector (O 2/3 2/3). This is the first time that this type of order is...... is observed in an fcc antiferromagnet....

  10. 轻度认知功能损害氢质子磁共振波谱变化及其意义%Changes of 1H-Magnetic resonance spectroscopy in patients with mild cognitive impairment and its signifi cance

    Institute of Scientific and Technical Information of China (English)

    刘森; 王长富; 郭亚

    2009-01-01

    目的:研究轻度认知功能损害(mild cognitive impairment,MCI)脑内代谢变化及其与认知功能间的关系,寻求诊断MCI之客观指标,并探讨其对防治老年性痴呆(Alzheimet's disease,AD)之重要意义.方法:选择20例MCI患者,按照1:1配对,挑选20例健康志愿者作为对照组,利用氢质子磁共振波谱(1 H-magnetic resonance spectroscopy,1H-MRS)的方法,分别检测额叶、颞叶海马区域NAA,ml及Cho等代谢产物波峰的峰高,并以Cr峰高作为标准,计算各代谢产物与其比值,比较两组间的差别;同时,对MCI组的MMSE评分和NAA/Cr,ml/Cr及Cho/Cr进行相关分析.结果:MCI组患者脑内额叶和颞叶海马区域NAA/Cr较正常对照组显著下降,而ml/Cr和Cho/Cr与对照组间无显著差异.MCI组MMSE评分与额叶和海马区域NAA/Cr间均呈正相关关系,与nd/Cr及Cho/Cr间均无显著相关关系.结论:利用1H-MRS可以检测MCI患者脑内代谢变化,为MCI之诊断提供客观指标,且NAA/Cr变化可作为认知损害程度的客观指标,对AD早期防治具有重要意义.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-10-21

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

  12. Anvil cell gasket design for high pressure nuclear magnetic resonance experiments beyond 30 GPa.

    Science.gov (United States)

    Meier, Thomas; Haase, Jürgen

    2015-12-01

    Nuclear magnetic resonance (NMR) experiments are reported at up to 30.5 GPa of pressure using radiofrequency (RF) micro-coils with anvil cell designs. These are the highest pressures ever reported with NMR, and are made possible through an improved gasket design based on nano-crystalline powders embedded in epoxy resin. Cubic boron-nitride (c-BN), corundum (α-Al2O3), or diamond based composites have been tested, also in NMR experiments. These composite gaskets lose about 1/2 of their initial height up to 30.5 GPa, allowing for larger sample quantities and preventing damages to the RF micro-coils compared to precipitation hardened CuBe gaskets. It is shown that NMR shift and resolution are less affected by the composite gaskets as compared to the more magnetic CuBe. The sensitivity can be as high as at normal pressure. The new, inexpensive, and simple to engineer gaskets are thus superior for NMR experiments at high pressures.

  13. Anvil cell gasket design for high pressure nuclear magnetic resonance experiments beyond 30 GPa

    Energy Technology Data Exchange (ETDEWEB)

    Meier, Thomas; Haase, Jürgen [Faculty of Physics and Earth Sciences, University of Leipzig, Linnéstrasse 5, Leipzig 04103 (Germany)

    2015-12-15

    Nuclear magnetic resonance (NMR) experiments are reported at up to 30.5 GPa of pressure using radiofrequency (RF) micro-coils with anvil cell designs. These are the highest pressures ever reported with NMR, and are made possible through an improved gasket design based on nano-crystalline powders embedded in epoxy resin. Cubic boron-nitride (c-BN), corundum (α-Al{sub 2}O{sub 3}), or diamond based composites have been tested, also in NMR experiments. These composite gaskets lose about 1/2 of their initial height up to 30.5 GPa, allowing for larger sample quantities and preventing damages to the RF micro-coils compared to precipitation hardened CuBe gaskets. It is shown that NMR shift and resolution are less affected by the composite gaskets as compared to the more magnetic CuBe. The sensitivity can be as high as at normal pressure. The new, inexpensive, and simple to engineer gaskets are thus superior for NMR experiments at high pressures.

  14. Parameter analysis for a nuclear magnetic resonance gyroscope based on 133Cs–129Xe/131Xe

    Science.gov (United States)

    Zhang, Da-Wei; Xu, Zheng-Yi; Zhou, Min; Xu, Xin-Ye

    2017-02-01

    We theoretically investigate several parameters for the nuclear magnetic resonance gyroscope based on 133Cs–129Xe/131Xe. For a cell containing a mixture of 133Cs at saturated pressure, we investigate the optimal quenching gas (N2) pressure and the corresponding pump laser intensity to achieve 30% 133Cs polarization at the center of the cell when the static magnetic field B 0 is 5 {{μ }}{{T}} with different 129Xe/131Xe pressure. The effective field produced by spin-exchange polarized 129Xe or 131Xe sensed by 133Cs can also be discussed in different 129Xe/131Xe pressure conditions. Furthermore, the relationship between the detected signal and the probe laser frequency is researched. We obtain the optimum probe laser detuning from the D2 (6{}2{{S}}1/2\\to 6{}2{{P}}3/2) resonance with different 129Xe/131Xe pressure owing to the pressure broadening. Project supported by the National High Technology Research and Development Program of China (Grant No. 2014AA123401), the National Key Basic Research and Development Program of China (Grant Nos. 2016YFA0302103 and 2012CB821302), the National Natural Science Foundation of China (Grant 11134003), and Shanghai Excellent Academic Leaders Program of China (Grant No. 12XD1402400).

  15. Study on signal intensity of low field nuclear magnetic resonance via an indirect coupling measurement

    Institute of Scientific and Technical Information of China (English)

    Jiang Feng-Ying; Wang Ning; Jin Yi-Rong; Deng Hui; Tian Ye; Lang Pei-Lin; Li Jie

    2013-01-01

    We carry out an ultra-low-field nuclear magnetic resonance (NMR) experiment based on high-Tc superconducting quantum interference devices (SQUIDs).The measurement field is in a micro-tesla range (~10 μT-100 μT) and the experiment is conducted in a home-made magnetically-shielded-room (MSR).The measurements are performed by the indirect coupling method in which the signal of nuclei precession is indirectly coupled to the SQUID through a tuned copper coil transformer.In such an arrangement,the interferences of applied measurement and polarization field to the SQUID sensor are avoided and the performance of the SQUID is not destroyed.In order to compare the detection sensitivity obtained by using the SQUID with that achieved using a conventional low-noise-amplifier,we perform the measurements using a connercial room temperature amplifier.The results show that in a wide frequency range (~1 kHz-10 kHz) the measurements with the SQUID sensor exhibit a higher signal-to-noise ratio,Further,we discuss the dependence of NMR peak magnitude on measurement frequency.We attribute the reduction of the peak magnitude at high frequency to the increased field inhomogeneity as the measurement field increases.This is verified by compensating the field gradient using three sets of gradient coils.

  16. Cesium removal from nuclear waste using a magnetical CuHCNPAN nano composite

    Science.gov (United States)

    Mobtaker, Hossein Ghasemi; Yousefi, Taher; Pakzad, Seyed Mohammadreza

    2016-12-01

    A nano-composite of copper hexacyanoferrate@polyacrylonitrile@magnetite (CuHCNPAN) was synthesized through chemical co-precipitation. The product were characterized using FT IR, XRD, SEM and TG techniques. The results of FTIR, XRD confirmed the composite formation. The SEM images showed that the particles are 20-60 nm in diameter. The composite showed high mechanical, chemical and thermal stability. The nano composite was used for removal of cesium ions from waste solutions. Effect of various parameters such as contact time, initial concentration, pH, competition ions and temperature were studied. After the metal ion adsorption process the magnetic separation of adsorbent from absorbents was carried out through external magnetic field. Maximum sorption capacity was about 260 mg/g. The kinetic studies showed that the equilibrium was achieved at 5 h and the experimental data fitted by the second order model. The adsorption isotherm was best modeled by Longmuir isotherm. The endothermic and spontaneous (and entropy increasing) nature of sorption process were approved by thermodynamic results. The results cleared which the synthesized CuHCNPAM composite is promising adsorbent for removal of cesium ions from nuclear waste.

  17. Solid-state 27Al nuclear magnetic resonance investigation of three aluminum-centered dyes

    KAUST Repository

    Mroué, Kamal H.

    2010-02-01

    We report the first solid-state 27Al NMR study of three aluminum phthalocyanine dyes: aluminum phthalocyanine chloride, AlPcCl (1); aluminum-1,8,15,22-tetrakis(phenylthio)-29H,31H-phthalocyanine chloride, AlPc(SPh)4Cl (2); and aluminum-2,3-naphthalocyanine chloride, AlNcCl (3). Each of these compounds contains Al3+ ions coordinating to four nitrogen atoms and a chlorine atom. Solid-state 27Al NMR spectra, including multiple-quantum magic-angle spinning (MQMAS) spectra and quadrupolar Carr-Purcell-Meiboom-Gill (QCPMG) spectra of stationary powdered samples have been acquired at multiple high magnetic field strengths (11.7, 14.1, and 21.1 T) to determine their composition and number of aluminum sites, which were analyzed to extract detailed information on the aluminum electric field gradient (EFG) and nuclear magnetic shielding tensors. The quadrupolar parameters for each 27Al site were determined from spectral simulations, with quadrupolar coupling constants (CQ) ranging from 5.40 to 10.0 MHz and asymmetry parameters (η) ranging from 0.10 to 0.50, and compared well with the results of quantum chemical calculations of these tensors. We also report the largest 27Al chemical shielding anisotropy (CSA), with a span of 120 ± 10 ppm, observed directly in a solid material. The combination of MQMAS and computational predictions are used to interpret the presence of multiple aluminum sites in two of the three samples.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-01-01

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

  19. 1H-magnetic resonance spectroscopy in diagnosis of vascular dementia after stroke%氢质子磁共振波谱分析对脑卒中后血管性痴呆患者的诊断价值

    Institute of Scientific and Technical Information of China (English)

    李瑾; 乐先杰; 何迎春

    2011-01-01

    目的 利用氢质子磁共振波谱分析(1H-MRS)技术研究脑卒中后血管性痴呆(VD)患者颞叶海马区细胞代谢水平及其用于临床诊断的价值.方法 对年龄相匹配的脑卒中后VD患者18例、脑卒中非VD患者13例及来源于门诊就诊者14例正常对照组,行双侧颞叶海马区1H-MRS检测,3组患者双侧颞叶海马区N-乙酰天门冬氨酸盐(NAA)/肌酸(Cr)比值、胆碱复合物(Cho)/Cr比值.结果 脑卒中后VD组患者NAA/C比值较正常对照组及脑卒中非VD组均下降(P<0.05 或0.01);而Cho/Cr比值较正常对照组明显升高(P<0.05 ),较脑卒中非VD组左侧升高(P<0.05),但右侧的差异无统计学意义(P >0.05).脑卒中非VD组NAA/Cr比值及Cho/Cr比值较正常对照组虽有变化,但差异无统计学意义(P >0.05).脑卒中后VD组MMSE评分与双侧颞叶海马区NAA/Cr及Cho/Cr比值有相关性(P<0.05),且MMSE分数越低,NAA/Cr比值越低,而Cho/Cr比值越高.结论 利用1H-MRS技术研究脑卒中后VD患者双侧颞叶海马区细胞代谢水平,有助于早期发现脑卒中后VD.%To investigate the diagnostic value of 1H-magnetic resonance spectroscopy (1H-MRS) for vas-cular dementia! VD) in stroke patients.MethodsEighteen stroke patients with VD, 13 stroke patients without VD and 14 healthysubjects matched for age were enrolled in the study. 1H-MRS examinations of bilateral hippocampus were conducted in all patients; the N-acetylaspartate( NAA),choline(Cho)and creatine(Cr)were measured and the ratios of NAA/Cr and Cho/Cr were compared among groups.The patients with VD had a significantly lower NAA/Cr ratio in bilateral temporal hippocam-pus regions than normal controls and the stroke patients without VD (P0.05). There were no significant differences in NAA/Cr ratio and Cho/Cr ratio between patients without VD and normal controls. Relative-regression analysis found that MMSE scores were positively correlated with NAA/Cr and negatively correlated with Cho/Cr in

  20. Nobel Prize in Chemistry 1991 "for his contributions to the development of the methodology of high resolution nuclear magnetic resonance (NMR) spectroscopy": Richard R. Ernst

    CERN Multimedia

    1992-01-01

    Prof. Richard R. Ernst presents "The domestication of nuclear spins by chemists and biologists".The usage of nuclear spins in chemistry and biology for exploring the structure and dynamics of matter is discussed. The main emphasis is put on the methodological aspects of multidimensional nuclear magnetic resonance (NMR) spectroscopy that are responsible for the success of this powerful analytical technique.