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Sample records for acoustic nuclear magnetic resonance

  1. Metal and Metal Alloy Hydride Nuclear Acoustic Resonance and Nuclear Magnetic Resonance.

    Science.gov (United States)

    Hudson, Rebecca Scholz

    Effects of interstitial hydrogen on the quadrupole coupled nuclear acoustic resonance (NAR) and the (skin depth) nuclear magnetic resonance (NMR) line shapes and magnetic field positions of ('51)V and ('93)Nb were studied at 300K and 1 tesla in annealed single crystals of the transition metal alloys Nb(,.96)V(,.04)H(,x) (x (LESSTHEQ) .07), V(,.96)Nb(,.04)H(,x) (x (LESSTHEQ) .04), Ta(,.96)Nb(,.07)H(,x) (x (LESSTHEQ) .20) and Ta(,.68)Nb.04H(,x) (x (LESSTHEQ) .23), with the hydrogen in the gaseous (alpha) phase. This work was undertaken to further the understanding of the role of hydrogen in alloys. Static quadrupole effects dominate the line widths, with the ('51)V NMR in the NbV alloys exhibiting first order broadening, the ('93)Nb NMR line width broadened in second order in Nb(,.96)V(,.04),Ta(,.68)Nb(,.32) and Ta(,.93)Nb(,.07), and the ('93)Nb NAR in Nb(,.96)V(,.04) broadened more than an order of magnitude over the pure niobium NAR. No ('181)Ta NAR was observed, due to severe quadrupole effects coupled with its large quadrupole moment. As hydrogen is absorbed by Nb(,.96)V(,.04), the ('93)Nb NMR and NAR line widths narrow and the ('51)V Knight shift increases, in accord with a previous study which proposes the vanadium atoms trap hydrogen in their nearest neighboring tetrahedral sites. This is compatible with the increase seen in the ('51)V line width, thought to arise from the sharing of trapped hydrogen by neighboring vanadium atoms. The absorption of hydrogen by V(,.96)Nb(,.04) initially relieves the quadrupole broadening of ('51)V NMR but finally broadens the line width, while causing the ('51)V Knight shift to increase. This is consistent with a model in which hydrogen avoids sites near the Nb atoms. The absorption of hydrogen narrows the ('93)Nb line width in Ta(,93)Nb(,.07) but appears to have no effect on it in Ta(,.68)Nb(,.32), while the ('93)Nb Knight shift is increased slightly in both alloys. Also, the first measurement of the dipole coupled NAR of ('25

  2. Acoustic nuclear magnetic resonance due to generation of sound waves in metals

    International Nuclear Information System (INIS)

    Solovarov, N.K.

    1975-01-01

    Nuclear magnetic resonance (NMR) in a metallic plate is considered taking account of acoustic waves (AW) generated by an outer electromagnetic field. In observing the NMR in a conducting media it is suggested that only nuclear spins in a thin skin-layer, participate in the energy resonance absorption. Electromagnetic wave penetration into a sample in the presence of a constant magnetic field is followed by a direct sound generation. Acoustic NMR can be observed during interaction of excited AW with nuclear spins. Energy absorption by nuclear spins occurs over the whole volume of the sample by means of helicons and AW. In this case the NMR signal is the summarized absorption one. It is necessary to analize every time carefully the nature of the observed signal . Relative values of contributions into the NMR signal of the following mechanisms of sound absorption by the nuclear spin-system are estimated in the present paper: 1) electromagnetic absorption taking no account of sound generation; 2) the mechanism of the magnetic dipole absorption of AW, generated in the sample; 3) the mechanism of absorption of AW different from that of the magnetic dipole mechanism. The results of numerical estimates are represented graphically. The conclusions are as follows: 1) in the majority of cases it is necessary to take into account sound generation in metals in observing NMR; 2) contributions due to mechanisms diferent from the magnetic dipole mechanism of absorption of the sound, generated in the sample by the spin-system, may be significant

  3. Nuclear acoustic resonance in metals

    International Nuclear Information System (INIS)

    Mueller, V.; Bartell, U.

    1979-01-01

    A comprehensive quantum theoretical treatment of nuclear acoustic resonance (NAR) in metals is presented for the first time. Basic equations describing the NAR-absorption and NAR-dispersion are derived from the sound induced perturbation Hamiltonian ih(t) by applying a generalized form of the 'Kubo susceptibility'. It is shown that in metals, where a sound wave may induce nuclear magnetic dipole and nuclear electric quadrupole transitions simultaneously, the appearance of interference terms enables one to determine not only the absolute values but also the signs of the gradient-elastic tensor components. Explicit expressions are displayed for the dipolar, quadrupolar and interference contributions to the generalized NAR susceptibility in cubic metals. As an example the derivative of the expected 93 Nb NAR-absorption line ( Δm =1) is calculated for different signs of the gradient elastic tensor component S 44 . (orig.) [de

  4. Nuclear magnetic resonance gyroscope

    International Nuclear Information System (INIS)

    Grover, B.C.

    1984-01-01

    A nuclear magnetic resonance gyro using two nuclear magnetic resonance gases, preferably xenon 129 and xenon 131, together with two alkaline metal vapors, preferably rubidium, potassium or cesium, one of the two alkaline metal vapors being pumped by light which has the wavelength of that alkaline metal vapor, and the other alkaline vapor being illuminated by light which has the wavelength of that other alkaline vapor

  5. Nuclear Magnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    Nuclear magnetic resonance in condensed matter was discov- ered simultaneously by Edward Purcell at Harvard and Felix. Bloch at Stanford in 1946 using different instrumentation and techniques. Both groups observed the response of magnetic nuclei, placed in a uniform magnetic field, to a continuous radio frequency ...

  6. Nuclear Magnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 1. Nuclear Magnetic Resonance Spectroscopy. Susanta Das. General Article Volume 9 Issue 1 January 2004 pp 34-49. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/009/01/0034-0049. Keywords.

  7. Nuclear Magnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 9; Issue 1. Nuclear Magnetic Resonance Spectroscopy. Susanta Das. General Article Volume 9 Issue 1 January 2004 pp 34-49. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/009/01/0034-0049. Keywords.

  8. Advanced Nuclear Magnetic Resonance

    OpenAIRE

    Alonso, Diego A.

    2014-01-01

    Transparencias en inglés de la asignatura "Resonancia Magnética Nuclear Avanzada" (Advanced Nuclear Magnetic Resonance) (36643) que se imparte en el Máster de Química Médica como asignatura optativa de 3 créditos ECTS. En esta asignatura se completa el estudio iniciado en la asignatura de quinto curso de la licenciatura en Química "Determinación estructural" (7448) y en la del Grado de Química de tercer curso "Determinación estructural de los compuestos orgánicos" (26030) en lo referente a té...

  9. Nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Cremin, B.J.

    1981-01-01

    Recent advances in diagnostic imaging, have been the medical application of nuclear magnetic resonance (NMR). It's been used to study the structure of various compounds in chemistry and physics, and in the mid-1970 to produce images of rabbits and eventually of the human hand and head. The images are produced by making use of the nuclear magnetization of the hydrogen ion, or proton, that is present in biological material to record the density distribution of protons in cellular water and lipids. An exploration of the end-results of complicated free induction decay signals, that have been digitized and frequency-analysed by mathematical computerized techniques to produce an image of tissue density, is given. At present NMR produces images comparable to those of early computed tomography

  10. Nuclear Magnetic Resonance Gyroscope

    Science.gov (United States)

    Larsen, Michael; Bulatowicz, Michael; Clark, Philip; Griffith, Robert; Mirijanian, James; Pavell, James

    2015-05-01

    The Nuclear Magnetic Resonance Gyroscope (NMRG) is being developed by the Northrop Grumman Corporation (NGC). Cold and hot atom interferometer based gyroscopes have suffered from Size, Weight, and Power (SWaP) challenges and limits in bandwidth, scale factor stability, dead time, high rotation rate, vibration, and acceleration. NMRG utilizes the fixed precession rate of a nuclear spin in a constant magnetic field as a reference for determining rotation, providing continuous measurement, high bandwidth, stable scale factor, high rotation rate measurement, and low sensitivity to vibration and acceleration in a low SWaP package. The sensitivity to vibration has been partially tested and demonstrates no measured sensitivity within error bars. Real time closed loop implementation of the sensor significantly decreases environmental and systematic sensitivities and supports a compact and low power digital signal processing and control system. Therefore, the NMRG technology holds great promise for navigation grade performance in a low cost SWaP package. The poster will describe the history, operation, and design of the NMRG. General performance results will also be presented along with recent vibration test results.

  11. Fourier transform nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Geick, R.

    1981-01-01

    This review starts with the basic principles of resonance phenomena in physical systems. Especially, the connection is shown between the properties of these systems and Fourier transforms. Next, we discuss the principles of nuclear magnetic resonance. Starting from the general properties of physical systems showing resonance phenomena and from the special properties of nuclear spin systems, the main part of this paper reviews pulse and Fourier methods in nuclear magnetic resonance. Among pulse methods, an introduction will be given to spin echoes, and, apart from the principle of Fourier transform nuclear magnetic resonance, an introduction to the technical problems of this method, e.g. resolution in the frequency domain, aliasing, phase and intensity errors, stationary state of the spin systems for repetitive measurements, proton decoupling, and application of Fourier methods to systems in a nonequilibrium state. The last section is devoted to special applications of Fourier methods and recent developments, e.g. measurement of relaxation times, solvent peak suppression, 'rapid scan'-method, methods for suppressing the effects of dipolar coupling in solids, two-dimensional Fourier transform nuclear magnetic resonance, and spin mapping or zeugmatography. (author)

  12. 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...

  13. Nuclear Magnetic Resonance

    Indian Academy of Sciences (India)

    IAS Admin

    The method- ology went through vigorous growth and development during this time, laying the theoretical basis for understanding a wide array of applications. The stage was set for ... nance (NMR) is the experimental observation of the resonant absorption of ..... siveness, ranging from qualitative to quantitative. More signifi-.

  14. Nuclear magnetic resonance contrast agents

    Science.gov (United States)

    Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

    1997-12-30

    A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 10 figs.

  15. Simple and Inexpensive Classroom Demonstrations of Nuclear Magnetic Resonance and Magnetic Resonance Imaging.

    Science.gov (United States)

    Olson, Joel A.; Nordell, Karen J.; Chesnik, Marla A.; Landis, Clark R.; Ellis, Arthur B.; Rzchowski, M. S.; Condren, S. Michael; Lisensky, George C.

    2000-01-01

    Describes a set of simple, inexpensive, classical demonstrations of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) principles that illustrate the resonance condition associated with magnetic dipoles and the dependence of the resonance frequency on environment. (WRM)

  16. Nuclear Magnetic Resonance Trackbed Moisture Sensor System

    Science.gov (United States)

    2018-02-01

    In this initial phase, conducted from March 2015 through December 2016, Vista Clara and its subcontractor Zetica Rail successfully developed and tested a man-portable, non-invasive spot-check nuclear magnetic resonance (NMR) moisture sensor that dire...

  17. Generation of nuclear magnetic resonance images

    International Nuclear Information System (INIS)

    Beckmann, N.X.

    1986-01-01

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

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

    International Nuclear Information System (INIS)

    Quibilan, E.I.

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

  19. NMR magnetic field controller for pulsed nuclear magnetic resonance experiments

    International Nuclear Information System (INIS)

    Scheler, G.; Anacker, M.

    1975-01-01

    A nuclear magnetic resonance controller for magnetic fields, which can also be used for pulsed NMR investigations, is described. A longtime stability of 10 -7 is achieved. The control signal is generated by a modified time sharing circuit with resonance at the first side band of the 2 H signal. An exact calibration of the magnetic field is achieved by the variation of the H 1 - or of the time-sharing frequency. (author)

  20. Nuclear magnetic resonance - from molecules to man

    OpenAIRE

    Wüthrich, Kurt

    2017-01-01

    Initial observations of the physical phenomenon of nuclear magnetic resonance (NMR) date back to the late 1940s. In the following two decades high-resolution NMR in solution became an indispensible analytical tool in chemistry, and solid state NMR had an increasingly important role in physics. Some of the potentialities of the method for investigations of complex biological systems had also long been anticipated, and initial experiments with biological specimens were described already 30 year...

  1. Force-detected Nuclear Magnetic Resonance

    OpenAIRE

    Poggio, M.; Herzog, B. E.

    2017-01-01

    The drive to improve the sensitivity of nuclear magnetic resonance (NMR) to smaller and smaller sample volumes has led to the development of a variety of techniques distinct from conventional inductive detection. In this chapter, we focus on the technique of force-detected NMR as one of the most successful in yielding sensitivity improvements. We review the rationale for the technique, its basic principles, and give a brief history of its most important results. We then cover in greater detai...

  2. Nuclear Magnetic Resonance imaging; Resonance magnetique nucleaire

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-06-01

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

  3. An absolute nuclear magnetic resonance magnetometer

    International Nuclear Information System (INIS)

    Salvi, A.

    1961-10-01

    After an introduction in which the various work undertaken since the discovery of nuclear magnetic resonance is rapidly reviewed, the author describes briefly In the first chapter three types of NMR magnetometers, giving the advantages and disadvantages of each of them and deducing from this the design of the apparatus having the greatest number of qualities Chapter II is devoted to the crossed coil nuclear oscillator which operates continuously over a wide range (800 gamma). To avoid an error due to a carrying over the frequency, the measurement is carried out using bands of 1000 γ. Chapter III deals with frequency measurements. The author describes an original arrangement which makes possible the frequency-field conversion with an accuracy of ± 5 x 10 -6 , and the differential measurement between two nuclear oscillators. The report finishes with a conclusion and a few recordings. (author) [fr

  4. Nuclear magnetic resonance common laboratory, quadrennial report

    International Nuclear Information System (INIS)

    1994-01-01

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

  5. Nanoscale nuclear magnetic resonance with chemical resolution

    Science.gov (United States)

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

    2017-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Noyszewski, E.A.; Raman, J.; Trupin, S.R.; McFarlin, B.L.; Dawson, M.J. (Univ. of Illinois, Urbana-Champaign (USA))

    1989-08-01

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

  7. Nuclear resonance apparatus including means for rotating a magnetic field

    International Nuclear Information System (INIS)

    Sugimoto, H.

    1983-01-01

    A nuclear magnetic resonance apparatus including magnet apparatus for generating a homogeneous static magnetic field between its magnetic poles, shims of a magnetic substance mounted on the magnetic poles to apply a first gradient magnetic field intensity distribution in a direction orthogonal as to the direction of line of magnetic force of the static magnetic field, gradient magnetic field generating electromagnetic apparatus for generating a second gradient magnetic field having a gradient magnetic field intensity distribution in superimposition with the static magnetic field and for changing the magnetic field gradient of the first gradient magnetic field, an oscillator for generating an oscillating output having a frequency corresponding to the nuclear magnetic resonance condition of an atomic nucleus to be measured, a coil wound around a body to be examined for applying the output of said oscillator as electromagnetic waves upon the body, a receiver for detecting the nuclear magnetic resonance signals received by the coil, a gradient magnetic field controller making a magnetic field line equivalent to the combined gradient magnetic fields and for rotating the line along the section of the body to be examined by controlling said gradient magnetic field generating electromagnetic apparatus and devices for recording the nuclear magnetic resonance signals, for reconstructing the concentration distribution of the specific atomic nuclei in the section of the body, and a display unit for depicting the result of reconstruction

  8. Nuclear magnetic resonance and plant metabolic engineering.

    Science.gov (United States)

    Shachar-Hill, Yair

    2002-01-01

    Nuclear magnetic resonance (NMR) can be used to measure metabolite levels and metabolic fluxes, to probe the intracellular environment, and to follow transport and energetics nondestructively. NMR methods are therefore powerful aids to understanding plant metabolism and physiology. Both spectroscopy and imaging can help overcome the unique challenges that plants present to the metabolic engineer by detecting, identifying, quantifying, and localizing novel metabolites in vivo and in extracts; revealing the composition and physical state of cell wall and other polymers; allowing the identification of active pathways; providing quantitative measures of metabolic flux; and testing hypotheses about the effects of engineered traits on plant physiological function. The aim of this review is to highlight recent studies in which NMR has contributed to metabolic engineering of plants and to illustrate the unique characteristics of NMR measurements that give it the potential to make greater contributions in the future.

  9. Nuclear magnetic resonance imaging of the spine

    International Nuclear Information System (INIS)

    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

  10. Spatial localization in nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Keevil, Stephen F

    2006-01-01

    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)

  11. Chiral discrimination in nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Lazzeretti, Paolo

    2017-11-01

    Chirality is a fundamental property of molecules whose spatial symmetry is characterized by the absence of improper rotations, making them not superimposable to their mirror image. Chiral molecules constitute the elementary building blocks of living species and one enantiomer is favoured in general (e.g. L-aminoacids and D-sugars pervade terrestrial homochiral biochemistry) because most chemical reactions producing natural substances are enantioselective. Since the effect of chiral chemicals and drugs on living beings can be markedly different between enantiomers, the quest for practical spectroscopical methods to scrutinize chirality is an issue of great importance and interest. Nuclear magnetic resonance (NMR) is a topmost analytical technique, but spectrometers currently used are ‘blind’ to chirality, i.e. unable to discriminate the two mirror-image forms of a chiral molecule, because, in the absence of a chiral solvent, the spectral parameters, chemical shifts and spin-spin coupling constants are identical for enantiomers. Therefore, the development of new procedures for routine chiral recognition would offer basic support to scientists. However, in the presence of magnetic fields, a distinction between true and false chirality is mandatory. The former epitomizes natural optical activity, which is rationalized by a time-even pseudoscalar, i.e. the trace of a second-rank tensor, the mixed electric dipole/magnetic dipole polarizability. The Faraday effect, magnetic circular dichroism and magnetic optical activity are instead related to a time-odd axial vector. The present review summarizes recent theoretical and experimental efforts to discriminate enantiomers via NMR spectroscopy, with the focus on the deep connection between chirality and symmetry properties under the combined set of fundamental discrete operations, namely charge conjugation, parity (space inversion) and time (motion) reversal.

  12. Selectivity in multiple quantum nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Warren Sloan [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division

    1980-11-01

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

  13. Nuclear magnetic resonance imaging of the kidney

    International Nuclear Information System (INIS)

    Hricak, H.; Crooks, L.; Sheldon, P.; Kaufman, L.

    1983-01-01

    The role of nuclear magnetic resonance (NMR) imaging of the kidney was analyzed in 18 persons (6 normal volunteers, 3 patients with pelvocaliectasis, 2 with peripelvic cysts, 1 with renal sinus lipomatosis, 3 with renal failure, 1 with glycogen storage disease, and 2 with polycystic kidney disease). Ultrasound and/or computed tomography (CT) studies were available for comparison in every case. In the normal kidney distinct anatomical structures were clearly differentiated by NMR. The best anatomical detail ws obtained with spin echo (SE) imaging, using a pulse sequence interval of 1,000 msec and an echo delay time of 28 msec. However, in the evaluation of normal and pathological conditions, all four intensity images (SE 500/28, SE 500/56, SE 1,000/28, and SE 1,000/56) have to be analyzed. No definite advantage was found in using SE imaging with a pulse sequence interval of 1,500 msec. Inversion recovery imaging enhanced the differences between the cortex and medulla, but it had a low signal-to-noise level and, therefore, a suboptimal overall resolution. The advantages of NMR compared with CT and ultrasound are discussed, and it is concluded that NMR imaging will prove to be a useful modality in the evaluation of renal disease

  14. Nuclear magnetic resonance imaging of the kidney

    Energy Technology Data Exchange (ETDEWEB)

    Hricak, H.; Crooks, L.; Sheldon, P.; Kaufman, L.

    1983-02-01

    The role of nuclear magnetic resonance (NMR) imaging of the kidney was analyzed in 18 persons (6 normal volunteers, 3 patients with pelvocaliectasis, 2 with peripelvic cysts, 1 with renal sinus lipomatosis, 3 with renal failure, 1 with glycogen storage disease, and 2 with polycystic kidney disease). Ultrasound and/or computed tomography (CT) studies were available for comparison in every case. In the normal kidney distinct anatomical structures were clearly differentiated by NMR. The best anatomical detail ws obtained with spin echo (SE) imaging, using a pulse sequence interval of 1,000 msec and an echo delay time of 28 msec. However, in the evaluation of normal and pathological conditions, all four intensity images (SE 500/28, SE 500/56, SE 1,000/28, and SE 1,000/56) have to be analyzed. No definite advantage was found in using SE imaging with a pulse sequence interval of 1,500 msec. Inversion recovery imaging enhanced the differences between the cortex and medulla, but it had a low signal-to-noise level and, therefore, a suboptimal overall resolution. The advantages of NMR compared with CT and ultrasound are discussed, and it is concluded that NMR imaging will prove to be a useful modality in the evaluation of renal disease.

  15. Quantum information processing and nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Cummins, H.K.

    2001-01-01

    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 of composite rotations, tailored composite rotations, presented in Chapter 5. Chapter 6 describes some of the advantages and pitfalls of combining composite rotations. Experimental evaluations of the composite rotations are given in each case. An actual implementation of a quantum information protocol, approximate quantum cloning, is presented in Chapter 7. The dissertation ends with appendices which contain expansions of some equations and detailed calculations of certain composite rotation results, as well as spectrometer pulse sequence programs. (author)

  16. Nuclear magnetic resonance studies of metabolic regulation

    International Nuclear Information System (INIS)

    Sillerud, L.O.; Han, C.H.; Whaley, T.W.

    1983-01-01

    Nuclear magnetic resonance (NMR) techniques for the detection of the metabolic transformations of biological compounds labeled with stable isotopes, particularly carbon-13 have been explored. We have studied adipose tissue in the intact rat, the exteriorized epididymal fat pad, and the isolated adipocyte. Triacylglycerol metabolism in adipose tissue is regulated by lipogenic factors (insulin, corticosterone, thyroxine, and growth hormone) and lipolytic factors (glucagon and catecholamines). The synthesis of triglyceride from 5.5 mM glucose was stimulated by about 4-fold by 10 nM insulin. Triglyceride synthesis from glucose in the presence of insulin occurred at a rate of 330 nmol/hr/10 6 cells. Since the NMR signals from free and esterified fatty acids and glycerol are distinct, we could directly measure the rate of hormone-stimulated lipolysis. Epinephrine (10 μM) gave a lipolytic rate of 0.30 μmol/hr/10 6 cells as monitored by free-glycerol appearance in the medium. 13 C NMR provides a superior method for the measurement of triglyceride metabolism since it directly measures the changes in the substrates and products in situ

  17. Quantitative dosing by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Solomon, I.

    1958-01-01

    The measurement of the absolute concentration of a heavy water reference containing approximately 99.8 per cent of D 2 O has been performed, by an original magnetic resonance method ('Adiabatic fast passage method') with a precision of 5.10 -5 on the D 2 O concentration. (author) [fr

  18. 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)

  19. The Nuclear Magnetic Resonance and its utilization in image formation

    International Nuclear Information System (INIS)

    Bonagamba, T.J.; Tannus, A.; Panepucci, H.

    1987-01-01

    Some aspects about Nuclear Magnetic Resonance (as Larmor Theorem, radio frequency pulse, relaxation of spins system) and its utilization in two dimensional image processing with the necessity of a tomography plane are studied. (C.G.C.) [pt

  20. GEOCHEMICAL CONTROLS ON NUCLEAR MAGNETIC RESONANCE MEASUREMENTS

    International Nuclear Information System (INIS)

    Knight, Rosemary

    2008-01-01

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

  1. Nuclear magnetic resonance spectroscopy in food applications: a critical appraisal

    International Nuclear Information System (INIS)

    Divakar, S.

    1998-01-01

    Usefulness of Nuclear Magnetic Resonance (NMR) spectroscopy in food applications is presented in this review. Some of the basic concepts of NMR pertaining to one-dimensional and two-dimensional techniques, solid-state NMR and Magnetic Resonance Imaging (MRI) are discussed. Food applications dealt with encompass such diverse areas like nature and state of water in foods, detection and quantitation of important constituents of foods, intact food systems and NMR related to food biology. (author)

  2. Nuclear magnetic resonance in cardiology: cardiac MRI

    International Nuclear Information System (INIS)

    Fernandez, Claudio C.

    2003-01-01

    As a new gold standard for mass, volume and flow, the magnetic resonance imaging (MRI) is probably the most rapidly evolving technique in the cardiovascular diagnosis. An integrated cardiac MRI examination allows the evaluation of morphology, global and regional function, coronary anatomy, perfusion, viability and myocardial metabolism, all of them in only one diagnostic test and in a totally noninvasive manner. The surgeons can obtain relevant information on all aspects of diseases of the heart and great vessels, which include anatomical details and relationships with the greatest field of view, and may help to reduce the number of invasive procedures required in pre and postoperative evaluation. However, despite these excellent advantages the present clinical utilization of MRI is still too often restricted to few pathologies or case studies in which other techniques fail to identify the cardiac or cardiovascular abnormalities. If magnetic resonance is an excellent method for diagnosing so many different cardiac conditions, why is so little it used in routine cardiac practice? Cardiologists are still not very familiar with the huge possibilities or cardiovascular MRI utilities. Our intention is to give a comprehensive survey of many of the clinical applications of this challenger technique in the study of the heart and great vessels. Those who continue to ignore this important and mature imaging technique will rightly fail to benefit. (author) [es

  3. Dynamical Nuclear Magnetic Resonance Imaging of Micron-scale Liquids

    Science.gov (United States)

    Sixta, Aimee; Choate, Alexandra; Maeker, Jake; Bogat, Sophia; Tennant, Daniel; Mozaffari, Shirin; Markert, John

    We report our efforts in the development of Nuclear Magnetic Resonance Force Microscopy (NMRFM) for dynamical imaging of liquid media at the micron scale. Our probe contains microfluidic samples sealed in thin-walled (µm) quartz tubes, with a micro-oscillator sensor nearby in vacuum to maintain its high mechanical resonance quality factor. Using 10 µm spherical permalloy magnets at the oscillator tips, a 3D T1-resolved image of spin density can be obtained by reconstruction from our magnetostatics-modelled resonance slices; as part of this effort, we are exploring single-shot T1 measurements for faster dynamical imaging. We aim to further enhance imaging by using a 2 ω technique to eliminate artifact signals during the cyclic inversion of nuclear spins. The ultimate intent of these efforts is to perform magnetic resonance imaging of individual biological cells.

  4. Bipolar programmable current supply for superconducting nuclear magnetic resonance magnets

    Science.gov (United States)

    Koivuniemi, Jaakko; Luusalo, Reeta; Hakonen, Pertti

    1998-09-01

    In high resolution continuous-wave nuclear magnetic resonance (NMR) work well-reproducible, linear sweeps of current are needed. We have developed a microcontroller based programmable current supply, tested with superconducting magnets with inductance of 10 mH and 10 H. We achieved a resolution and noise of 4 ppm. The supply has an internal sweep with programmable ramping rate and a possibility for remote operation from a computer with either GPIB or RS232 interface. It is based on an 18-bit D/A converter. The maximum output current is ±10 A, the sweep rate can be set between 1 μA/s-140 mA/s, and the maximum output voltage is ±2.5 V. In work at ultralow temperatures, especially in superconducting quantum interference device NMR, all rf interference to the experiment should be avoided. One of the sources of this kind of unwanted input is the digital switching noise of fast logic devices. We discuss this problem in the context of our design.

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

    International Nuclear Information System (INIS)

    Jaturonrusmee, Wasna; Arthonvorakul, Areerat; Assateranuwat, Adisorn

    2005-10-01

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

  6. Acoustic characterization of Thiel liver for magnetic resonance-guided focused ultrasound treatment.

    Science.gov (United States)

    Karakitsios, Ioannis; Joy, Joyce; Mihcin, Senay; Melzer, Andreas

    2017-04-01

    The purpose of this work was to measure the essential acoustic parameters, i.e., acoustic impedance, reflection coefficient, attenuation coefficient, of Thiel embalmed human and animal liver. The Thiel embalmed tissue can be a promising, pre-clinical model to study liver treatment with Magnetic Resonance-guided Focused Ultrasound (MRgFUS). Using a single-element transducer and the contact pulse-echo method, the acoustic parameters, i.e., acoustic impedance, reflection coefficient and attenuation coefficient of Thiel embalmed human and animal liver were measured. The Thiel embalmed livers had higher impedance, similar reflection and lower attenuation compared to the fresh tissue. Embalming liver with Thiel fluid affects its acoustic properties. During MRgFUS sonication of a Thiel organ, more focused ultrasound (FUS) will be backscattered by the organ, and higher acoustic powers are required to reach coagulation levels (temperatures >56 °C).

  7. Nuclear magnetic resonance of randomly diluted magnetic materials

    International Nuclear Information System (INIS)

    Magon, C.J.

    1985-01-01

    The temperature dependence of the nuclear relaxation rates and line shapes of the F O resonance in the diluted antiferromagnet Fe x Zn 1-x F 2 and Mn x Zn 1-x F 2 are studied over a large temperature range T N 1 ) of the F O nuclei, which are not transfer hyperfine coupled to the Fe (or Mn) spins, have been measured and calculated as a function of the concentration x. Good agreement with experiment is found for the theoretical results, which have been obtained in the range 0.1 ≤ x ≤ 0.8. The temperature dependence of 1/T 1 for T N 1 data near T N was used to study Random Field Effects on the critical behavior of Mn .65 Zn . 3 5 F 2 , for fields applied parallel and perpendicular to the easy (C) axis. It was found that the transition temperature T N depressed substantially with field only for H o || C. The experimental results are in general accord with the theory for Random Field Effects in disordered, anisotropic antiferromagnets. The critical divergence of the inhomogeneously broadened F O NMR was studied in Fe .6 Zn .4 F 2 above T N . The experimental results agree with Heller's calculation of the NMR line broadening by Random Field Effects. With H o || C the line shape changes from Gaussian towards Lozentzian for t -2 and below T N its line width increase qualitatively following the increase in the sublattice magnetization. (author)

  8. 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

  9. Pulse sequence generator for nuclear magnetic resonance spectrometer

    International Nuclear Information System (INIS)

    Bartusek, K.

    1990-01-01

    The hardware and the properties are described of a pulsed sequence generator for a 200 MHz nuclear magnetic resonance spectrometer designed by the Institute for Research of Instrumentation of the Czechoslovak Academy of Sciences in Brno. The universal design of the generator meets the requirements of both NMR tomography and NMR microscopy. (author). 3 figs., 6 refs

  10. Selection of planes in nuclear magnetic resonance tomography

    International Nuclear Information System (INIS)

    Bonagamba, T.J.

    1986-01-01

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

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

    Science.gov (United States)

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

    2014-01-21

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

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

    International Nuclear Information System (INIS)

    2011-01-01

    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.

  13. 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.

  14. A Methodology to Integrate Magnetic Resonance and Acoustic Measurements for Reservoir Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Parra, J.O.

    2001-01-26

    The objective of this project was to develop an advanced imaging method, including pore scale imaging, to integrate magnetic resonance (MR) techniques and acoustic measurements to improve predictability of the pay zone in two hydrocarbon reservoirs. This was accomplished by extracting the fluid property parameters using MR laboratory measurements and the elastic parameters of the rock matrix from acoustic measurements to create poroelastic models of different parts of the reservoir. Laboratory measurements were compared with petrographic analysis results to determine the relative roles of petrographic elements such as porosity type, mineralogy, texture, and distribution of clay and cement in creating permeability heterogeneity.

  15. Real-time optimization of nuclear magnetic resonance experiments

    Science.gov (United States)

    Song, Y.-Q.; Tang, Yiqiao; Hürlimann, M. D.; Cory, D. G.

    2018-04-01

    Nuclear Magnetic Resonance (NMR) experiments are typically performed with predetermined pulse sequences and acquisition parameters, and are oftentimes sub-optimal for individual samples under investigation. Here we explore a class of real-time optimization methods that conducts stochastic analyses on the acquired data and in turn updates and optimizes the subsequent measurements. We show superiority of the method to static approaches, both in the efficiency and quality of data acquisition, for a wide range of experiments.

  16. Chemometric Analysis of Nuclear Magnetic Resonance Spectroscopy Data

    Energy Technology Data Exchange (ETDEWEB)

    ALAM,TODD M.; ALAM,M. KATHLEEN

    2000-07-20

    Chemometric analysis of nuclear magnetic resonance (NMR) spectroscopy has increased dramatically in recent years. A variety of different chemometric techniques have been applied to a wide range of problems in food, agricultural, medical, process and industrial systems. This article gives a brief review of chemometric analysis of NMR spectral data, including a summary of the types of mixtures and experiments analyzed with chemometric techniques. Common experimental problems encountered during the chemometric analysis of NMR data are also discussed.

  17. Application of blind source separation to nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Nuzillard, D.; Bourg, St.; Nuzillard, J.M.

    1999-01-01

    Blind source separation is intended to decompose signal mixtures into statistically independent components. Application of this technique to the analysis of organic molecules by nuclear magnetic resonance (NMR) are presented. The goal of this study is to demonstrate the simplification of spectral analysis in three cases: the analysis of mixtures of compounds, the analysis of a single mixture and the splitting of the spectrum of a pure compound into simpler sub-spectra. (authors)

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

    International Nuclear Information System (INIS)

    Newman, R.J.

    1984-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Newman, R.J. (Glasgow Western Infirmary (UK))

    1984-09-01

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

  20. Display of cross sectional anatomy by nuclear magnetic resonance imaging.

    Science.gov (United States)

    Hinshaw, W S; Andrew, E R; Bottomley, P A; Holland, G N; Moore, W S

    1978-04-01

    High definition cross-sectional images produced by a new nuclear magnetic resonance (NMR) technique are shown. The images are a series of thin section scans in the coronal plane of the head of a rabbit. The NMR images are derived from the distribution of the density of mobile hydrogen atoms. Various tissue types can be distinguished and a clear registration of gross anatomy is demonstrated. No known hazards are associated with the technique.

  1. Nuclear magnetic resonance tomography in Hallervorden-Spatz's syndrome

    International Nuclear Information System (INIS)

    Vogl, T.; Bauer, M.; Seiderer, M.; Rath, M.

    1984-01-01

    Two patients (mother and son) with Hallervorden-Spatz's syndrome were examined both via CT and Nuclear Magnetic Resonance (NMR), using different measuring modes. In the patient with progressing disease pathological findings were seen in the right and left putamen with CT and NMR. All examinations in the mother with a less progressive syndrome were without any result. Information obtained via NMR did not yield significantly more relevant data than computed tomography. (orig.) [de

  2. Nuclear magnetic resonance studies of biological systems

    International Nuclear Information System (INIS)

    Antypas, W.G. Jr.

    1988-01-01

    The difference between intracellular and extracellular proton relaxation rates provides the basis for the determination of the mean hemoglobin concentration (MHC) in red blood cells. The observed water T 1 relaxation data from red blood cell samples under various conditions were fit to the complete equation for the time-dependent decay of magnetization for a two-compartment system including chemical exchange. The MHC for each sample was calculated from the hematocrit and the intracellular water fraction as determined by NMR. The binding of the phosphorylcholine (PC) analogue, 2-(trimethylphosphonio)-ethylphosphate (phosphoryl-phosphocholine, PPC) to the PC binding myeloma proteins TEPC-15, McPC 603, and MOPC 167 was studied by 31 P NMR

  3. Pulse Design in Solid-State Nuclear Magnetic Resonance

    DEFF Research Database (Denmark)

    Palani, Ravi Shankar

    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...... been discussed in the past in literature. Generalised expressions for the effective Hamiltonian using AHT are derived in the frequency domain in this dissertation, to allow for appreciation of the equivalence with Floquet theory mediated effective Hamiltonian. The derivation relies on the ability...

  4. A novel power amplification scheme for nuclear magnetic resonance/nuclear quadrupole resonance systems

    Science.gov (United States)

    Zhang, Xinwang; Schemm, Nathan; Balkır, Sina

    2011-03-01

    Nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR)-based chemical analysis systems have been widely utilized in various areas such as medicine, security, and academic research. In these applications, the power amplifier stage plays a key role in generating the required oscillating magnetic fields within a radio frequency coil that serves as the probe. However, the bulky size and relatively low efficiency of the traditional power amplification schemes employed present a bottleneck for the realization of compact sized and portable NMR and NQR systems. To address this problem, this work presents a class D voltage-switching power amplification scheme with novel fast-start and fast-stop functions that are suitable for generating ideal NMR and NQR excitation signals. Compared to the traditional analog power amplifiers (PAs), the proposed switched-mode PA can achieve significant improvement on the power efficiency as well as the physical volume. A PA circuit for portable NQR-based explosive detection systems has been designed and built using the proposed scheme with 1 kW possible maximum output power and 10 MHz maximum operating frequency. Test results show that the presented PA achieves more than 60% measured efficiency within a highly compact volume while sustaining fast start and stop of excitation signals in the order of microseconds.

  5. High resolution spectroscopy in solids by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Bonagamba, T.J.

    1991-07-01

    The nuclear magnetic resonance (NMR) techniques for High Resolution Spectroscopy in Solids are described. Also the construction project of a partially home made spectrometer and its applications in the characterization of solid samples are shown in detail. The high resolution spectrometer used is implemented with the double resonance multiple pulses sequences and magic angle spinning (MAS) and can be used with solid and liquid samples. The maximum spinning frequency for the MAS experiment is in excess of 5 Khz, the double resonance sequences can be performed with any type of nucleus, in the variable temperature operating range with nitrogen gas: -120 0 C to +160 0 C, and is fully controlled by a Macintosh IIci microcomputer. (author)

  6. Nuclear Magnetic Resonance Applications to Unconventional Fossil Fuel Resources

    Science.gov (United States)

    Kleinberg, R. L.; Leu, G.

    2008-12-01

    Technical and economic projections strongly suggest that fossil fuels will continue to play a dominant role in the global energy market through at least the mid twenty-first century. However, low-cost conventional oil and gas will be depleted in that time frame. Therefore new sources of energy will be needed. We discuss two relatively untapped unconventional fossil fuels: heavy oil and gas hydrate. In both cases, nuclear magnetic resonance plays a key role in appraising the resource and providing information needed for designing production processes.

  7. Implementation of Quantum Private Queries Using Nuclear Magnetic Resonance

    International Nuclear Information System (INIS)

    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. (general)

  8. 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.

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

    International Nuclear Information System (INIS)

    Prestes, Rosilene A.; Almeida, Denise Milleo; Barison, Andersson; Pinheiro, Luis Antonio; Wosiacki, Gilvan

    2012-01-01

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

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

    International Nuclear Information System (INIS)

    Marmion, D.M.

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

  11. Real-time optimization of nuclear magnetic resonance experiments.

    Science.gov (United States)

    Song, Y-Q; Tang, Yiqiao; Hürlimann, M D; Cory, D G

    2018-04-01

    Nuclear Magnetic Resonance (NMR) experiments are typically performed with predetermined pulse sequences and acquisition parameters, and are oftentimes sub-optimal for individual samples under investigation. Here we explore a class of real-time optimization methods that conducts stochastic analyses on the acquired data and in turn updates and optimizes the subsequent measurements. We show superiority of the method to static approaches, both in the efficiency and quality of data acquisition, for a wide range of experiments. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. A highly integrated FPGA-based nuclear magnetic resonance spectrometer.

    Science.gov (United States)

    Takeda, Kazuyuki

    2007-03-01

    The digital circuits required for a nuclear magnetic resonance (NMR) spectrometer, including a pulse programmer, a direct digital synthesizer, a digital receiver, and a PC interface, have been built inside a single chip of the field-programmable gate-array (FPGA). By combining the FPGA chip with peripheral analog components, a compact, laptop-sized homebuilt spectrometer has been developed, which is capable of a rf output of up to 400 MHz with amplitude-, phase-, frequency-, and pulse-modulation. The number of rf channels is extendable up to three without further increase in size.

  13. Internal defect inspection in magnetic tile by using acoustic resonance technology

    Science.gov (United States)

    Xie, Luofeng; Yin, Ming; Huang, Qinyuan; Zhao, Yue; Deng, Zhenbo; Xiang, Zhaowei; Yin, Guofu

    2016-11-01

    This paper focuses on the validity of a nondestructive methodology for magnetic tile internal defect inspection based on acoustic resonance. The principle of this methodology is to analyze the acoustic signal collected from the collision of magnetic tile with a metal block. To accomplish the detection process, the separating part of the detection system is designed and discussed in detail in this paper. A simplified mathematical model is constructed to analyze the characteristics of the impact of magnetic tile with a metal block. The results demonstrate that calculating the power spectrum density (PSD) can diagnose the internal defect of magnetic tile. Two different data-driven multivariate algorithms are adopted to obtain the feature set, namely principal component analysis (PCA) and hierarchical nonlinear principal component analysis (h-NLPCA). Three different classifiers are then performed to deal with magnetic tile classification problem based on features extracted by PCA or h-NLPCA. The classifiers adopted in this paper are fuzzy neural networks (FNN), variable predictive model based class discrimination (VPMCD) method and support vector machine (SVM). Experimental results show that all six methods are successful in identifying the magnetic tile internal defect. In this paper, the effect of environmental noise is also considered, and the classification results show that all the methods have high immunity to background noise, especially PCA-SVM and h-NLPCA-SVM. Considering the accuracy rate, computation cost problem and the ease of implementation, PCA-SVM turns out to be the best method for this purpose.

  14. 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.

  15. Investigating the emotional response to room acoustics: A functional magnetic resonance imaging study.

    Science.gov (United States)

    Lawless, M S; Vigeant, M C

    2015-10-01

    While previous research has demonstrated the powerful influence of pleasant and unpleasant music on emotions, the present study utilizes functional magnetic resonance imaging (fMRI) to assess the positive and negative emotional responses as demonstrated in the brain when listening to music convolved with varying room acoustic conditions. During fMRI scans, subjects rated auralizations created in a simulated concert hall with varying reverberation times. The analysis detected activations in the dorsal striatum, a region associated with anticipation of reward, for two individuals for the highest rated stimulus, though no activations were found for regions associated with negative emotions in any subject.

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

    International Nuclear Information System (INIS)

    Charpentier, Th.

    2007-10-01

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

  17. Programmable quantum-state discriminator by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Gopinath, T.; Das, Ranabir; Kumar, Anil

    2005-01-01

    A programmable quantum-state discriminator is implemented by using nuclear magnetic resonance. We use a two-qubit spin-1/2 system, one for the data qubit and one for the ancilla (program) qubit. This device does the unambiguous (error-free) discrimination of a pair of states of the data qubit that are symmetrically located about a fixed state. The device is used to discriminate both linearly polarized states and elliptically polarized states. The maximum probability of successful discrimination is achieved by suitably preparing the ancilla qubit. It is also shown that the probability of discrimination depends on the angle of the unitary operator of the protocol and ellipticity of the data qubit state

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

    CERN Document Server

    MacKenzie, Kenneth J D

    2002-01-01

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

  19. Structural and conformational study of polysaccharides by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Bossennec, Veronique

    1989-01-01

    As some natural polysaccharides are involved in important biological processes, the use of nuclear magnetic resonance appears to be an adapted mean to determine their structure-activity relationship and is therefore the object of this research thesis. By using bi-dimensional proton-based NMR techniques, it is possible to identify minority saccharide units, to determine their conformation, and to identify units which they are bound to. The author reports the application of these methods to swine mucosa heparin, and to heparins displaying a high and low anticoagulant activity. The dermatan sulphate has also been studied, and the NMR analysis allowed some polymer structure irregularities to be identified. A molecular modelling of dermatan sulphate has been performed [fr

  20. 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.

  1. Applications of nuclear magnetic resonance imaging in process engineering

    Science.gov (United States)

    Gladden, Lynn F.; Alexander, Paul

    1996-03-01

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

  2. 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.

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

    International Nuclear Information System (INIS)

    Bertrand, P.

    1987-01-01

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

  4. 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.

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

    Science.gov (United States)

    Fan, Non Q.; Clarke, John

    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.

  6. Nuclear magnetic resonance experiments with dc SQUID amplifiers

    International Nuclear Information System (INIS)

    Heaney, M.B.

    1990-11-01

    The development and fabrication of dc SQUIDs (Superconducting QUantum Interference Devices) with Nb/Al 2 O 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 x 10 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 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

  7. 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. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Threedimensional imaging of organ structures by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Waters, W.; Smolorz, J.; Wellner, U.

    1985-01-01

    A simple method for threedimensional imaging of organ structures is presented. The method is based on a special acquisition mode in a nuclear resonance tomograph, exciting layers of 20 cm thickness at different angulations. The display is done by cinematography (which is usually used in nuclear cardiology) projecting the structures in a rotating movement. (orig.) [de

  9. Magnetic Resonance Force Microscopy System

    Data.gov (United States)

    Federal Laboratory Consortium — The Magnetic Resonance Force Microscopy (MRFM) system, developed by ARL, is the world's most sensitive nuclear magnetic resonance (NMR) spectroscopic analysis tool,...

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

    International Nuclear Information System (INIS)

    Colvin, M; Krishnan, V V

    2003-01-01

    The power of a quantum computer (QC) relies on the fundamental concept of the superposition in quantum mechanics and thus allowing an inherent large-scale parallelization of computation. In a QC, binary information embodied in a quantum system, such as spin degrees of freedom of a spin-1/2 particle forms the qubits (quantum mechanical bits), over which appropriate logical gates perform the computation. In classical computers, the basic unit of information is the bit, which can take a value of either 0 or 1. Bits are connected together by logic gates to form logic circuits to implement complex logical operations. The expansion of modern computers has been driven by the developments of faster, smaller and cheaper logic gates. As the size of the logic gates become smaller toward the level of atomic dimensions, the performance of such a system is no longer considered classical but is rather governed by quantum mechanics. Quantum computers offer the potentially superior prospect of solving computational problems that are intractable to classical computers such as efficient database searches and cryptography. A variety of algorithms have been developed recently, most notably Shor's algorithm for factorizing long numbers into prime factors in polynomial time and Grover's quantum search algorithm. The algorithms that were of only theoretical interest as recently, until several methods were proposed to build an experimental QC. These methods include, trapped ions, cavity-QED, coupled quantum dots, Josephson junctions, spin resonance transistors, linear optics and nuclear magnetic resonance. Nuclear magnetic resonance (NMR) is uniquely capable of constructing small QCs and several algorithms have been implemented successfully. NMR-QC differs from other implementations in one important way that it is not a single QC, but a statistical ensemble of them. Thus, quantum computing based on NMR is considered as ensemble quantum computing. In NMR quantum computing, the spins with

  11. A METHODOLOGY TO INTEGRATE MAGNETIC RESONANCE AND ACOUSTIC MEASUREMENTS FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Jorge O. Parra; Chris L. Hackert; Lorna L. Wilson

    2002-09-20

    The work reported herein represents the third year of development efforts on a methodology to interpret magnetic resonance and acoustic measurements for reservoir characterization. In this last phase of the project we characterize a vuggy carbonate aquifer in the Hillsboro Basin, Palm Beach County, South Florida, using two data sets--the first generated by velocity tomography and the second generated by reflection tomography. First, we integrate optical macroscopic (OM), scanning electron microscope (SEM) and x-ray computed tomography (CT) images, as well as petrography, as a first step in characterizing the aquifer pore system. This pore scale integration provides information with which to evaluate nuclear magnetic resonance (NMR) well log signatures for NMR well log calibration, interpret ultrasonic data, and characterize flow units at the field scale between two wells in the aquifer. Saturated and desaturated NMR core measurements estimate the irreducible water in the rock and the variable T{sub 2} cut-offs for the NMR well log calibration. These measurements establish empirical equations to extract permeability from NMR well logs. Velocity and NMR-derived permeability and porosity relationships integrated with velocity tomography (based on crosswell seismic measurements recorded between two wells 100 m apart) capture two flow units that are supported with pore scale integration results. Next, we establish a more detailed picture of the complex aquifer pore structures and the critical role they play in water movement, which aids in our ability to characterize not only carbonate aquifers, but reservoirs in general. We analyze petrography and cores to reveal relationships between the rock physical properties that control the compressional and shear wave velocities of the formation. A digital thin section analysis provides the pore size distributions of the rock matrix, which allows us to relate pore structure to permeability and to characterize flow units at the

  12. Nuclear Magnetic Resonance: new applications in the quantification and assessment of polysaccharide-based vaccine intermediates

    International Nuclear Information System (INIS)

    Garrido, Raine; Velez, Herman; Verez, Vicente

    2013-01-01

    Nuclear Magnetic Resonance has become the choice for structural studies, identity assays and simultaneous quantification of active pharmaceutical ingredient of different polysaccharide-based vaccine. In the last two decades, the application of quantitative Nuclear Magnetic Resonance had an increasing impact to support several quantification necessities. The technique involves experiments with several modified parameters in order to obtain spectra with quantifiable signals. The present review is supported by some recent relevant reports and it discusses several applications of NMR in carbohydrate-based vaccines. Moreover, it emphasizes and describes several parameters and applications of quantitative Nuclear Magnetic Resonance

  13. 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.

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

    International Nuclear Information System (INIS)

    Hricak, H.; Filly, R.A.; Margulis, A.R.; Moon, K.L.; Crooks, L.E.; Kaufman, L.

    1983-01-01

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

  15. 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.

  16. Visualization of cerebellopontine angle lesions by nuclear magnetic resonance imaging

    International Nuclear Information System (INIS)

    Ochiai, Chikayuki; Takakura, Kintomo; Machida, Tohru; Araki, Tsutomu; Iio, Masahiro; Basugi, Norihiko.

    1983-01-01

    The preliminary results from the clinical use a prototype whole body nuclear magnetic resonance (NMR) machine constructed by Toshiba Inc. are presented. Cranial NMR scans were performed on more than 30 cases with broad spectrum of neurologic diseases using saturation-recovery and inversion-recovery sequences with a field strength of 1500 Gauss. Selective excitation sequence was used for the slice selection and filtered backprojection was used to reconstruct the images. They were displayed on a 256 x 256 matrix as 12 mm thick sections. Data aquisition time varied between 3 and 12 minutes. Our initial experiences with six cases harboring cerebellopontine angle lesions discolsed advantages and disadvantages of NMR imaging in comparison with X-ray CT. The advantages were the absence of linear artifacts from the surrounding bone, the marked gray-white matter differentiation, and the variety of tomographic planes available. The disadvantages included the lack of bone detail, the lack of visualization of the major intracranial vessels, and the long time required for scanning (several minutes per slice). Although much continued evaluation is necessary, NMR seems to have vast potential as a diagnostic tool. (author)

  17. Updated methodology for nuclear magnetic resonance characterization of shales.

    Science.gov (United States)

    Washburn, Kathryn E; Birdwell, Justin E

    2013-08-01

    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. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. 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.

  19. Two-dimensional nuclear magnetic resonance of quadrupolar systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuanhu [Univ. of California, Berkeley, CA (United States)

    1997-09-01

    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.

  20. Novel nuclear magnetic resonance techniques for studying biological molecules

    International Nuclear Information System (INIS)

    Laws, David D.

    2000-01-01

    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 13 C 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 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.

  1. 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.

  2. Nuclear magnetic resonance imaging of the central nervous system

    International Nuclear Information System (INIS)

    Knaap, M.S. van der; Valk, J.

    1989-01-01

    In this article a review is given of the use of magnetic resonance imaging for the central nervous system. An example of the screening of the population for multiple scelerosis is given. A good preliminary examination and the supply of relevant information to the person which performs the imaging is necessary. (R.B.). 9 figs.; 4 tabs

  3. Optimal control of the inversion of two spins in Nuclear Magnetic Resonance

    International Nuclear Information System (INIS)

    Assémat, E.; Attar, L.; Penouilh, M.-J.; Picquet, M.; Tabard, A.; Zhang, Y.; Glaser, S.J.; Sugny, D.

    2012-01-01

    Highlights: ► We investigate the simultaneous optimal control of the inversion of two spins. ► We examine the energy minimum solution. ► We compare this solution with the time-minimum one. ► Experimental implementation using techniques of Nuclear Magnetic Resonance. -- Abstract: We investigate the optimal control of the inversion of two spin 1/2 particles in Nuclear Magnetic Resonance. The two spins, which differ by their resonance offset, are controlled by the same radio frequency magnetic field. Using the Pontryagin Maximum Principle, we compute the optimal control sequence which allows to reach the target state in a given time, while minimizing the energy of the magnetic field. A comparison with the time-optimal solution for bounded control amplitude realizing the same control in the same time is made. An experimental illustration is done using techniques of Nuclear Magnetic Resonance.

  4. Unconventional Tight Reservoirs Characterization with Nuclear Magnetic Resonance

    Science.gov (United States)

    Santiago, C. J. S.; Solatpour, R.; Kantzas, A.

    2017-12-01

    The increase in tight reservoir exploitation projects causes producing many papers each year on new, modern, and modified methods and techniques on estimating characteristics of these reservoirs. The most ambiguous of all basic reservoir property estimations deals with permeability. One of the logging methods that is advertised to predict permeability but is always met by skepticism is Nuclear Magnetic Resonance (NMR). The ability of NMR to differentiate between bound and movable fluids and providing porosity increased the capability of NMR as a permeability prediction technique. This leads to a multitude of publications and the motivation of a review paper on this subject by Babadagli et al. (2002). The first part of this presentation is dedicated to an extensive review of the existing correlation models for NMR based estimates of tight reservoir permeability to update this topic. On the second part, the collected literature information is used to analyze new experimental data. The data are collected from tight reservoirs from Canada, the Middle East, and China. A case study is created to apply NMR measurement in the prediction of reservoir characterization parameters such as porosity, permeability, cut-offs, irreducible saturations etc. Moreover, permeability correlations are utilized to predict permeability. NMR experiments were conducted on water saturated cores. NMR T2 relaxation times were measured. NMR porosity, the geometric mean relaxation time (T2gm), Irreducible Bulk Volume (BVI), and Movable Bulk Volume (BVM) were calculated. The correlation coefficients were computed based on multiple regression analysis. Results are cross plots of NMR permeability versus the independently measured Klinkenberg corrected permeability. More complicated equations are discussed. Error analysis of models is presented and compared. This presentation is beneficial in understanding existing tight reservoir permeability models. The results can be used as a guide for choosing

  5. Resolution Improvement in Multidimensional Nuclear Magnetic Resonance Spectroscopy of Proteins

    International Nuclear Information System (INIS)

    Duma, L.

    2004-01-01

    The work presented in this thesis is concerned with both liquid-state and solid-state nuclear magnetic resonance (NMR) spectroscopy. Most of this work is devoted to the investigation by solid-state NMR of C 13 -enriched compounds with the principal aim of presenting techniques devised for further improving the spectral resolution in multidimensional NMR of microcrystalline proteins. In fully C 13 -labelled compounds, the J-coupling induces a broadening of the carbon lineshapes. We show that spin-state-selective technique called IPAP can be successfully combined with standard polarisation transfer schemes in order to remove the J-broadening in multidimensional solid-state NMR correlation experiments of fully C 13 -enriched proteins. We present subsequently two techniques tailored for liquid-state NMR spectroscopy. The carbon directly detected techniques provide chemical shift information for all backbone hetero-nuclei. They are very attracting for the study of large bio-molecular systems or for the investigation of paramagnetic proteins. In the last part of this thesis, we study the spin-echo J-modulation for homonuclear two-spin 1/2 systems. Under magic-angle spinning, the theory of J-induced spin-echo modulation allows to derive a set of modulation regimes which give a spin-echo modulation exactly equal to the J-coupling. We show that the chemical-shift anisotropy and the dipolar interaction tend to stabilize the spin-echo J-modulation. The theoretical conclusions are supported by numerical simulations and experimental results obtained for three representative samples containing C 13 spin pairs. (author)

  6. Science and history explored by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Baias, Maria Antoaneta

    2009-01-01

    Nuclear Magnetic Resonance was chosen as the main tool for investigating different biological and chemical systems, as it is unique in providing the information details about the morphology and molecular structures and conformations by which the fundamental properties of these biological and chemical systems can be understood. Proton spin-diffusion experiments combined with 13 C CPMAS spectroscopy were successfully applied to characterize the changes that occur during the thermal denaturation of keratin fibers from wool and hair. A model describing both the effect of thermal denaturation and the effect of different chemical treatments on keratin fibers is presented. Proton NMR spectroscopy was used for studying the proton exchange in Sulfonated Polyether Ether Ketone proton exchange membranes revealing that the water exchange processes in hydrated SPEEK-silica membranes are more efficient when low concentrations of polyethoxysiloxane (PEOS) are used for the membrane preparation. Proton 1D exchange spectroscopy combined with transverse relaxation measurements offered good insight in the state of water in hydrated SPEEK/SiO 2 membranes revealing that concentrations of 5%-10% wt. PEOS could enhance the electrical conductivity of PEM. Hyperpolarized 129 Xe NMR spectroscopy was successfully applied for monitoring the free radical polymerization reactions of methyl methacrylate, methyl acrylate and the copolymerization of methyl methacrylate and methyl acrylate. The observation of Xe chemical shift and linewidths during the reactions reveal information about the polymer chain growths during the polymerizations. The successful application of the NMR-MOUSE to visualise the different anatomical layers with varying proton densities opens the possibility of its use in clinical studies such as osteoporosis for bone density measurements. The NMR-MOUSE was also successfully applied for the analysis of violins and bows and a classification of the violins and bows as a function of

  7. 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.

  8. Wavelet and adaptive filtration of the nuclear magnetic resonance signal

    Czech Academy of Sciences Publication Activity Database

    Bartušek, Karel

    2002-01-01

    Roč. 11, - (2002), s. 13 - 18 ISSN 0862-9846. [Datastat'01. Brno, 27.08.2001-30.08.2001] R&D Projects: GA ČR GA102/96/1136; GA AV ČR IAA2065201 Institutional research plan: CEZ:AV0Z2065902 Keywords : Wavelet filtration * adaptive filtration * magnetic resonance signal Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  9. Value of nuclear magnetic resonance imaging in cardiology

    International Nuclear Information System (INIS)

    Cabon-Martin, C.

    1987-01-01

    The present study summarizes an experience with Magnetic Resonance Imaging (MRI) in the evaluation of twelve patients with a variety of cardiac abnormalities (myocardial infarction, mural thrombi, obstructive cardiomyopathy, pericarditis). The results are compared with clinical data, with measurements from other techniques such as two-dimensional echocardiography and with the images in normal subjects. An anticipated advantage of MRI is the ability to provide better tissue characterization, than has been attained with other imaging techniques, by relaxation time measurement [fr

  10. Recent Trends in Low-Temperature Nuclear Orientation and Nuclear Magnetic Resonance on Oriented Nuclei

    International Nuclear Information System (INIS)

    Chaplin, D. H.; Hutchison, W. D.

    2001-01-01

    Recent trends in Low-Temperature Nuclear Orientation (LTNO) and its site-selective derivative, Nuclear Magnetic Resonance on Oriented Nuclei (NMRON), are reviewed. Traditional areas of endeavour using elemental ferromagnetic hosts remain strong with significant improvements in methodology since last reviewed [1]; but there are new emphases emerging in solid-state physics and especially magnetism. Exotic single crystals hosts and MBE-grown multi-layers are gaining increased prominence as the principal focus of LTNO study. Increasingly, in off-line work and very recent on-line implantation into insulators [2], the radioactive probes are often chosen to be isoelectronic with an abundant chemical species within the host, rather than representing an extremely dilute, electronic impurity spy. Recent NMRON on a heavy rare earth, isoelectronic probe in an ordered rare earth halide opens up new dimensions.

  11. 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.

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

    International Nuclear Information System (INIS)

    Goodson, Boyd M.

    1999-01-01

    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

  13. Nuclear Magnetic Resonance (NMR) Spectroscopic Characterization of Nanomaterials and Biopolymers

    Science.gov (United States)

    Guo, Chengchen

    Nanomaterials have attracted considerable attention in recent research due to their wide applications in various fields such as material science, physical science, electrical engineering, and biomedical engineering. Researchers have developed many methods for synthesizing different types of nanostructures and have further applied them in various applications. However, in many cases, a molecular level understanding of nanoparticles and their associated surface chemistry is lacking investigation. Understanding the surface chemistry of nanomaterials is of great significance for obtaining a better understanding of the properties and functions of the nanomaterials. Nuclear magnetic resonance (NMR) spectroscopy can provide a familiar means of looking at the molecular structure of molecules bound to surfaces of nanomaterials as well as a method to determine the size of nanoparticles in solution. Here, a combination of NMR spectroscopic techniques including one- and two-dimensional NMR spectroscopies was used to investigate the surface chemistry and physical properties of some common nanomaterials, including for example, thiol-protected gold nanostructures and biomolecule-capped silica nanoparticles. Silk is a natural protein fiber that features unique properties such as excellent mechanical properties, biocompatibility, and non-linear optical properties. These appealing physical properties originate from the silk structure, and therefore, the structural analysis of silk is of great importance for revealing the mystery of these impressive properties and developing novel silk-based biomaterials as well. Here, solid-state NMR spectroscopy was used to elucidate the secondary structure of silk proteins in N. clavipes spider dragline silk and B. mori silkworm silk. It is found that the Gly-Gly-X (X=Leu, Tyr, Gln) motif in spider dragline silk is not in a beta-sheet or alpha-helix structure and is very likely to be present in a disordered structure with evidence for 31-helix

  14. 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.

  15. Display of cross sectional anatomy by nuclear magnetic resonance imaging

    International Nuclear Information System (INIS)

    Hinshaw, W.S.; Andrew, E.R.; Bottomley, P.A.; Holland, G.N.; Moore, W.S.; Worthington, B.S.

    1978-01-01

    High definition cross-sectional images produced by a new nuclear magnetic resonace (NMR) technique are shown. The images are a series of thin section scans in the coronal plane of the head of a rabbit. The NMR images are derived from the distribution of the density of mobile hydrogen atoms. Various tissue types can be distinguished and a clear registration of gross anatomy is demonstrated. No known hazards are associated with the technique. (author)

  16. 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

    2016-12-02

    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.

  17. Microcomputer simulation of nuclear magnetic resonance imaging contrasts

    International Nuclear Information System (INIS)

    Le Bihan, D.

    1985-01-01

    The high information content of magnetic resonance images is due to the multiplicity of its parameters. However, this advantage introduces a difficulty in the interpretation of the contrast: an image is strongly modified according to the visualised parameters. The author proposes a micro-computer simulation program. After recalling the main intrinsic and extrinsic parameters, he shows how the program works and its interest as a pedagogic tool and as an aid for contrast optimisation of images as a function of the suspected pathology [fr

  18. Multiple-quantum nuclear magnetic resonance studies of sodium-23 in model and biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Pekar, J.J.

    1988-01-01

    Time-domain multiple-quantum nuclear magnetic resonance spectroscopy is applied to sodium-23 in gels, liquid crystals, cell suspensions, and intact human limbs. In many biological systems, interactions between the nuclear electric quadrupole moment and fluctuating electric field gradients cause the outer transitions, which contribute 60% of the nuclear magnetic resonance signal from the spin-3/2 nuclei, to relax faster than the central transition, which contributes the remains in 40% of the signal. New multiple-quantum experiments, designed specifically for quadrupolar spin-3/2 nuclei, reveal much information not usually available from conventional nuclear magnetic resonance spectroscopy, because they allow indirect measurement of the rapid relaxation rate of the outer transitions, and may highlight the distribution of sodium ions among microscopic physiological compartments such as intracellular space, the interstitium, and the vasculature. The use of venous occlusion plethysmography to alter this distribution is discussed.

  19. Ga nuclear magnetic resonance study of UTGa5(T = Ni,Pt)

    International Nuclear Information System (INIS)

    Kato, Harukazu; Sakai, Hironori; Tokunaga, Yo; Tokiwa, Yoshihumi; Ikeda, Shugo; Onuki, Yoshichika; Kambe, Shinsaku; Walstedt, Russell E

    2003-01-01

    Ga nuclear magnetic resonance measurements have been carried out for the 5f antiferromagnets UNiGa 5 and UPtGa 5 . The transferred field at the Ga nuclei has been evaluated. The magnetic structure in the antiferromagnetic region has been confirmed from the microscopic point of view. The mechanism of the hyperfine interaction is discussed

  20. Materials of the 39 Polish Seminar on Nuclear Magnetic Resonance and Its Applications - Abstracts

    International Nuclear Information System (INIS)

    2006-01-01

    The Report comprises abstracts of 78 communications presented during the 39 Polish Seminar on Nuclear Magnetic Resonance and Its Applications, held on November, 30 - December, 2006 in Cracow (PL). They cover a variety of research fields, including magnetic resonance imaging in vivo, applications of NMR spectroscopy to medical diagnosis, studies on molecular properties of different materials as well as quantum chemical calculations of NMR parameters

  1. 41 Polish Seminar on Nuclear Magnetic Resonance and Its Applications - Abstracts

    International Nuclear Information System (INIS)

    2008-01-01

    The Report consist of abstracts of 63 communications presented during the 41 Polish Seminar on Nuclear Magnetic Resonance and Its Applications, held on December 1-2, 2008 in Cracow. Presentations cover a variety of research fields, including magnetic resonance imaging in vivo, applications of NMR spectroscopy to medical diagnosis, studies on molecular properties of different materials as well as quantum chemical calculations of NMR parameters

  2. Towards a beyond 1 GHz solid-state nuclear magnetic resonance: External lock operation in an external current mode for a 500 MHz nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Takahashi, Masato; Maeda, Hideaki; Ebisawa, Yusuke; Tennmei, Konosuke; Yanagisawa, Yoshinori; Nakagome, Hideki; Hosono, Masami; Takasugi, Kenji; Hase, Takashi; Miyazaki, Takayoshi; Fujito, Teruaki; Kiyoshi, Tsukasa; Yamazaki, Toshio

    2012-01-01

    Achieving a higher magnetic field is important for solid-state nuclear magnetic resonance (NMR). But a conventional low temperature superconducting (LTS) magnet cannot exceed 1 GHz (23.5 T) due to the critical magnetic field. Thus, we started a project to replace the Nb 3 Sn innermost coil of an existing 920 MHz NMR (21.6 T) with a Bi-2223 high temperature superconducting (HTS) innermost coil. Unfortunately, the HTS magnet cannot be operated in persistent current mode; an external dc power supply is required to operate the NMR magnet, causing magnetic field fluctuations. These fluctuations can be stabilized by a field-frequency lock system based on an external NMR detection coil. We demonstrate here such a field-frequency lock system in a 500 MHz LTS NMR magnet operated in an external current mode. The system uses a 7 Li sample in a microcoil as external NMR detection system. The required field compensation is calculated from the frequency of the FID as measured with a frequency counter. The system detects the FID signal, determining the FID frequency, and calculates the required compensation coil current to stabilize the sample magnetic field. The magnetic field was stabilized at 0.05 ppm/3 h for magnetic field fluctuations of around 10 ppm. This method is especially effective for a magnet with large magnetic field fluctuations. The magnetic field of the compensation coil is relatively inhomogeneous in these cases and the inhomogeneity of the compensation coil can be taken into account.

  3. 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.

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

    Science.gov (United States)

    Bennett, George D.

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

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

    Science.gov (United States)

    Vegh, Viktor; Reutens, David C.

    2016-01-01

    Object 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. Materials and Methods 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. Results 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. Conclusions 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. PMID:27271886

  6. 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.

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

    Science.gov (United States)

    Vogel, Michael W; Giorni, Andrea; Vegh, Viktor; Pellicer-Guridi, Ruben; Reutens, David C

    2016-01-01

    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.

  8. Nuclear magnetic resonance determination of the dynamic molecular structure of the erythrocyte membrane

    International Nuclear Information System (INIS)

    Morariu, V.V.

    1980-01-01

    Nuclear magnetic resonance of 1 H, 2 H, 13 C, 31 P can give information about the molecular motion on the surface or in the depth of the erythrocyte membrane. In normal physiological conditions these information are restricted to polar head groups of the phospholipids and scialic acids. Resolved spectra of the hydrocarbon chains and proteins is possible only as a result of drastic physical or chemical treatments which removes the biomembrane from its physiological state. A major progress in this area could result by using the nuclear magnetic resonance techniques of high resolution in solids. There are also nuclear magnetic resonance methods for the investigation of water diffusional transport through the erythrocyte membranes. This can be used as a sensitive probe for the investigation of cooperative state transitions in normal or pathological altered biomembranes. (author)

  9. Development of nuclear magnetic resonance tomography technology - TORM

    International Nuclear Information System (INIS)

    Tannus, A.

    1987-01-01

    The development of hardware and software necessary to implement the Magnetic Resonance Imaging (MRI) techniques is described. The major subjects were the construction of an aquisition and control system which allowed the operation of a pulsed Fourier NMR spectrometer as a NMR Tomograph; further it was oriented the developing of a NMR spectrometer whose parameters could be easily reconfigured by the controlling system. As a result a sofisticated equipment which allows, more than the proposed, working with high resolution spectroscopic techniques and spectroscopy in solids, was obtained. Since the basic techniques employed in NMR and CT Tomographs are well known, a great emphasis was also given on the understanding of the image reconstruction techniques that constitutes today the frontier of research in this area. The results obtained with the system described here are considered good, comparable to the results from commercial units developed in cooperation with imaging groups located in universities abroad. (author) [pt

  10. Development and applications of NMR [nuclear magnetic resonance] in low fields and zero field

    International Nuclear Information System (INIS)

    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

  11. Nuclear magnetic resonance imaging in patients with hypertrophic and dilated cardiomyopathy

    International Nuclear Information System (INIS)

    Boisvieux, A.

    1987-01-01

    Patients with hypertrophic and dilated cardiomyopathy and normal subjects were investigated with nuclear magnetic resonance imaging. To evaluate the NMR scanner possibilities, the results were compared with the echocardiographic investigation of the same patients. The capabilities of NMR imaging to provide information about intracardiac anatomy are emphasized. This study is preceded by a description of the physical principles underlying the phenomenon of nuclear magnetic resonance and of the techniques used to obtain NMR images and a review of the clinical use of NMR imaging for cardiac diagnosis [fr

  12. The design of photoelectric signal processing system for a nuclear magnetic resonance gyroscope based on FPGA

    Science.gov (United States)

    Zhang, Xian; Zhou, Binquan; Li, Hong; Zhao, Xinghua; Mu, Weiwei; Wu, Wenfeng

    2017-10-01

    Navigation technology is crucial to the national defense and military, which can realize the measurement of orientation, positioning, attitude and speed for moving object. Inertial navigation is not only autonomous, real-time, continuous, hidden, undisturbed but also no time-limited and environment-limited. The gyroscope is the core component of the inertial navigation system, whose precision and size are the bottleneck of the performance. However, nuclear magnetic resonance gyroscope is characteristic of the advantage of high precision and small size. Nuclear magnetic resonance gyroscope can meet the urgent needs of high-tech weapons and equipment development of new generation. This paper mainly designs a set of photoelectric signal processing system for nuclear magnetic resonance gyroscope based on FPGA, which process and control the information of detecting laser .The photoelectric signal with high frequency carrier is demodulated by in-phase and quadrature demodulation method. Finally, the processing system of photoelectric signal can compensate the residual magnetism of the shielding barrel and provide the information of nuclear magnetic resonance gyroscope angular velocity.

  13. Seismic resonances of acoustic cavities

    Science.gov (United States)

    Schneider, F. M.; Esterhazy, S.; Perugia, I.; Bokelmann, G.

    2016-12-01

    The goal of an On-Site Inspection (OSI) is to clarify at a possible testsite whether a member state of the Comprehensive nuclear Test Ban Treaty (CTBT)has violated its rules by conducting a underground nuclear test. Compared toatmospheric and underwater tests underground nuclear explosions are the mostdifficult to detect.One primary structural target for the field team during an OSI is the detectionof an underground cavity, created by underground nuclear explosions. Theapplication of seismic-resonances of the cavity for its detection has beenproposed in the CTBT by mentioning "resonance seismometry" as possibletechnique during OSIs. We modeled the interaction of a seismic wave-field withan underground cavity by a sphere filled with an acoustic medium surrounded byan elastic full space. For this setting the solution of the seismic wave-fieldcan be computed analytically. Using this approach the appearance of acousticresonances can be predicted in the theoretical calculations. Resonance peaksappear in the spectrum derived for the elastic domain surrounding the acousticcavity, which scale in width with the density of the acoustic medium. For lowdensities in the acoustic medium as for an gas-filled cavity, the spectralpeaks become very narrow and therefore hard to resolve. The resonancefrequencies, however can be correlated to the discrete set of eigenmodes of theacoustic cavity and can thus be predicted if the dimension of the cavity isknown. Origin of the resonance peaks are internal reverberations of wavescoupling in the acoustic domain and causing an echoing signal that couples outto the elastic domain again. In the gas-filled case the amplitudes in timedomain are very low.Beside theoretical considerations we seek to find real data examples fromsimilar settings. As example we analyze a 3D active seismic data set fromFelsőpetény, Hungary that has been conducted between 2012 and 2014 on behalf ofthe CTBTO. In the subsurface of this area a former clay mine is

  14. Nuclear Magnetic Resonance Imaging in Endodontics: A Review.

    Science.gov (United States)

    Di Nardo, Dario; Gambarini, Gianluca; Capuani, Silvia; Testarelli, Luca

    2018-04-01

    This review analyzes the increasing role of magnetic resonance imaging (MRI) in dentistry and its relevance in endodontics. Limits and new strategies to develop MRI protocols for endodontic purposes are reported and discussed. Eligible studies were identified by searching the PubMed databases. Only original articles on dental structures, anatomy, and endodontics investigated by in vitro and in vivo MRI were included in this review. Original articles on MRI in dentistry not concerning anatomy and endodontics were excluded. All the consulted studies showed well-defined images of pathological conditions such as caries and microcracks. The enhanced contrast of pulp provided a high-quality reproduction of the tooth shape and root canal in vitro and in vivo. Assessment of periapical lesions is possible even without the use of contrast medium. MRI is a nonionizing technique characterized by high tissue contrast and high image resolution of soft tissues; it could be considered a valid and safe diagnostic investigation in endodontics because of its potential to identify pulp tissues, define root canal shape, and locate periapical lesions. Copyright © 2018 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  15. Ultra-low field nuclear magnetic resonance and magnetic resonance imaging to discriminate and identify materials

    Science.gov (United States)

    Kraus, Robert H.; Matlashov, Andrei N.; Espy, Michelle A.; Volegov, Petr L.

    2010-03-30

    An ultra-low magnetic field NMR system can non-invasively examine containers. Database matching techniques can then identify hazardous materials within the containers. Ultra-low field NMR systems are ideal for this purpose because they do not require large powerful magnets and because they can examine materials enclosed in conductive shells such as lead shells. The NMR examination technique can be combined with ultra-low field NMR imaging, where an NMR image is obtained and analyzed to identify target volumes. Spatial sensitivity encoding can also be used to identify target volumes. After the target volumes are identified the NMR measurement technique can be used to identify their contents.

  16. Methodology for nuclear magnetic resonance and ion cyclotron resonance mass spectrometry

    International Nuclear Information System (INIS)

    Sehgal, Akansha

    2014-01-01

    This thesis encompasses methodological developments in both nuclear magnetic resonance and Fourier transform ion cyclotron resonance mass spectrometry. The NMR section explores the effects of scalar relaxation on a coupled nucleus to measure fast exchange rates. In order to quantify these rates accurately, a precise knowledge of the chemical shifts of the labile protons and of the scalar couplings is normally required. We applied the method to histidine where no such information was available a priori, neither about the proton chemical shifts nor about the one-bond scalar coupling constants J( 1 H 15 N), since the protons were invisible due to fast exchange. We have measured the exchange rates of the protons of the imidazole ring and of amino protons in histidine by indirect detection via 15 N. Not only the exchange rate constants, but also the elusive chemical shifts of the protons and the coupling constants could be determined. For the mass spectrometry section, the ion isolation project was initiated to study the effect of phase change of radiofrequency pulses. Excitation of ions in the ICR cell is a linear process, so that the pulse voltage required for ejecting ions must be inversely proportional to the pulse duration. A continuous sweep pulse propels the ion to a higher radius, whereas a phase reversal causes the ion to come to the centre. This represents the principle of 'notch ejection', wherein the ion for which the phase is reversed is retained in the ICR cell, while the remaining ions are ejected. The manuscript also contains a theoretical chapter, wherein the ion trajectories are plotted by solving the Lorentzian equation for the three-pulse scheme used for two-dimensional ICR. Through our simulations we mapped the ion trajectories for different pulse durations and for different phase relations. (author)

  17. Development and optimization of resonators and ways of detection in nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Behr, Volker Christian

    2008-01-01

    Aims of this dissertation were to construct resonators for very high flux densities and to develop appropriate probe bases. These were successfully realized with numerous resonators as well as two kinds of probe bases. Furthermore, new techniques and methods of signal detection were developed and evaluated. Magnetic flux guides, which were unknown in NMR up until now were used for the first time for both transmission and reception. Moreover, an optical acquisition technique based on the Faraday effect was realized and evaluated

  18. 29Si-nuclear magnetic resonance on the etching products of silicon in potassium hydroxide solutions

    NARCIS (Netherlands)

    Nijdam, A.J.; van Veenendaal, E.; Gardeniers, Johannes G.E.; Kentgens, A.P.M.; Nachtegaal, G.H.; Elwenspoek, Michael Curt

    We present results of 29Si-nuclear magnetic resonance experiments on a large number of KOH solutions in which silicon has been dissolved. The goal of the experiments is to clarify the chemical composition of concentrated alkaline solutions after etching of silicon. It is confirmed that the initial

  19. 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...

  20. 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...

  1. 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.

  2. Time domain-nuclear magnetic resonance study of chars from southern hardwoods

    Science.gov (United States)

    Thomas Elder; Nicole Labbe; David Harper; Timothy Rials

    2006-01-01

    Chars from the thermal degradation of silver maple (Acer saccharinum), red maple (Acer rubrum), sugar maple (Acer saccharum), and white oak (Quercus spp.), performed at temperatures from 250 to 350 oC, were examined using time domain-nuclear magnetic resonance...

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

    DEFF Research Database (Denmark)

    Aru, Violetta; Lam, Chloie; Khakimov, Bekzod

    2017-01-01

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

  4. 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

  5. Interaction between adrenaline and dibenzo-18-crown-6: Electrochemical, nuclear magnetic resonance, and theoretical study

    Science.gov (United States)

    Yu, Zhang-Yu; Liu, Tao; Wang, Xue-Liang

    2014-12-01

    The interaction between adrenaline (Ad) and dibenzo-18-crown-6 (DB18C6) was studied by cyclic voltammetry, nuclear magnetic resonance spectroscopy, and the theoretical calculations, respectively. The results show that DB18C6 will affect the electron transfer properties of Ad. DB18C6 can form stable supramolecular complexes with Ad through ion-dipole and hydrogen bond interactions.

  6. Phenomena in J-coupled nuclear magnetic resonance spectroscopy in low magnetic fields

    International Nuclear Information System (INIS)

    Appelt, Stephan; Haesing, F. Wolfgang; Kuehn, Holger; Bluemich, Bernhard

    2007-01-01

    We present the theory and experimental results of phenomena associated to J-coupled nuclear magnetic resonance (NMR) spectroscopy at low magnetic fields ( -4 T). So far it was believed that in low field the chemical shift and with it the homonuclear J-coupling information is lost. This contribution shows that the network of all homo- and heteronuclear J-coupling constants can be measured in low magnetic fields, thus revealing the whole molecular structure even in the absence of any chemical shift information. The chemical group of the form YX N (Y=rare spin 1/2, X=observed spin 1/2, N=number of spins X) can be identified by the number of lines in the heteronuclear coupled X spectrum if the strong J-coupling condition is valid. If two molecular groups, such as YX N and AX M-N (A=group without nuclear spin, M=total number of coupled spinsX), are bound together then all homo- and heteronuclear J-coupling constants appear in the X-NMR spectrum as pairs of multiplets. A vector model is presented which explains the relation between the molecular structure and the number of observed lines in a multiplet pair. The linewidths of the different NMR lines inside one multiplet are measured to be substantially different and depend on the total spin state of the molecule. If M is an odd number and M-1 spins X of the molecule are coupled into (M-1)/2 singlets, then intramolecular dipole-dipole relaxation as well as J-coupling mediated relaxation processes are suppressed and very narrow lines are observed

  7. Correlation between magnetic properties and nuclear magnetic resonance observations in Sr2FeMoO6 double perovskite

    International Nuclear Information System (INIS)

    Colis, S.; Pourroy, G.; Panissod, P.; Meny, C.; Dinia, A.

    2004-01-01

    We present the influence of the sintering temperature on the magnetic properties of Sr 2 FeMoO 6 double perovskite, on the basis of magnetization and nuclear magnetic resonance (NMR) measurements. Interestingly, the saturation magnetization originating mainly from the Fe moments is correlated with the amount of Mo magnetic moments observed by NMR measurements. We show that there is an optimum temperature of 1000 deg. C for which the reaction leading to the double perovskite becomes more advanced and/or the number of antisite defects is minimum

  8. Nuclear magnetic resonance imaging of the knee: examples of normal anatomy and pathology.

    Science.gov (United States)

    Kean, D M; Worthington, B S; Preston, B J; Roebuck, E J; McKim-Thomas, H; Hawkes, R C; Holland, G N; Moore, W S

    1983-06-01

    Nuclear magnetic resonance images of the knee were obtained from three normal volunteers and from two patients. The pathology included an osteosarcoma of the distal femur and a fracture of the tibia. Steady State Free Precession (SSFP) techniques were used with a 0.15 Tesla resistive type magnet. Normal anatomy was well displayed and the size of the osteosarcoma was accurately predicted. Using SSFP techniques, the blood in the knee joint was not visualised, but the underlying tibial fracture was clearly outlined.

  9. Nuclear magnetic resonance of external protons using continuous dynamical decoupling with shallow NV centers

    Science.gov (United States)

    de Las Casas, Charles; Ohno, Kenichi; Awschalom, David D.

    2015-03-01

    The nitrogen vacancy (NV) center in diamond is a paramagnetic defect with excellent spin properties that can reside within a few nanometers of the diamond surface, enabling atomic-scale magnetic resonance sensing of external nuclear spins. Here we use rotating frame longitudinal spin relaxation (T1ρ) based sensing schemes, known as Continuous Dynamical Decoupling (CDD), to detect external nuclear spins with shallow NV centers (DIAMANT program.

  10. 43. Polish Seminar on Nuclear Magnetic Resonance and its Applications. Cracow. Abstracts

    International Nuclear Information System (INIS)

    2010-12-01

    42 Polish Seminar on Nuclear Magnetic Resonance and its Applications, held on 1-2 December 2010 in Cracow (Poland), was devoted to the development of different magnetic resonance techniques and application of such techniques as crucial part of the studies. The Report contains 58 short descriptions of the contributions submitted by the participants of the Seminar. They cover all areas of the NMR application in major branches of basic chemistry, structural biology, medicine and materials science. Also recent results of the quantum chemical calculations of the NMR parameters are presented.

  11. 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.

  12. Acoustic spin pumping in magnetoelectric bulk acoustic wave resonator

    Directory of Open Access Journals (Sweden)

    N. I. Polzikova

    2016-05-01

    Full Text Available We present the generation and detection of spin currents by using magnetoelastic resonance excitation in a magnetoelectric composite high overtone bulk acoustic wave (BAW resonator (HBAR formed by a Al-ZnO-Al-GGG-YIG-Pt structure. Transversal BAW drives magnetization oscillations in YIG film at a given resonant magnetic field, and the resonant magneto-elastic coupling establishes the spin-current generation at the Pt/YIG interface. Due to the inverse spin Hall effect (ISHE this BAW-driven spin current is converted to a dc voltage in the Pt layer. The dependence of the measured voltage both on magnetic field and frequency has a resonant character. The voltage is determined by the acoustic power in HBAR and changes its sign upon magnetic field reversal. We compare the experimentally observed amplitudes of the ISHE electrical field achieved by our method and other approaches to spin current generation that use surface acoustic waves and microwave resonators for ferromagnetic resonance excitation, with the theoretically expected values.

  13. Acoustic spin pumping in magnetoelectric bulk acoustic wave resonator

    Energy Technology Data Exchange (ETDEWEB)

    Polzikova, N. I., E-mail: polz@cplire.ru; Alekseev, S. G.; Pyataikin, I. I.; Kotelyanskii, I. M.; Luzanov, V. A.; Orlov, A. P. [Kotel’nikov Institute of Radio Engineering and Electronics of Russian Academy of Sciences, Mokhovaya 11, building 7, Moscow, 125009 (Russian Federation)

    2016-05-15

    We present the generation and detection of spin currents by using magnetoelastic resonance excitation in a magnetoelectric composite high overtone bulk acoustic wave (BAW) resonator (HBAR) formed by a Al-ZnO-Al-GGG-YIG-Pt structure. Transversal BAW drives magnetization oscillations in YIG film at a given resonant magnetic field, and the resonant magneto-elastic coupling establishes the spin-current generation at the Pt/YIG interface. Due to the inverse spin Hall effect (ISHE) this BAW-driven spin current is converted to a dc voltage in the Pt layer. The dependence of the measured voltage both on magnetic field and frequency has a resonant character. The voltage is determined by the acoustic power in HBAR and changes its sign upon magnetic field reversal. We compare the experimentally observed amplitudes of the ISHE electrical field achieved by our method and other approaches to spin current generation that use surface acoustic waves and microwave resonators for ferromagnetic resonance excitation, with the theoretically expected values.

  14. Advances in magnetic resonance 10

    CERN Document Server

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 10, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters that examine superoperators in magnetic resonance; ultrasonically modulated paramagnetic resonance; and the utility of electron paramagnetic resonance (EPR) and electron-nuclear double-resonance (ENDOR) techniques for studying low-frequency modes of atomic fluctuations and their significance for understanding the mechanism of structural phase transitions in solids.

  15. Nuclear magnetic resonance at 310 MHz in a superconducting solenoid

    International Nuclear Information System (INIS)

    Dunand, J.J.

    1970-01-01

    The realisation of an NMR spectrometer with a superconducting magnet is presented in the first section. The methods to attain the best possible homogeneity of the magnetic field and to minimize the error in the spectrometer are described. The second section is devoted to the study of elastomers and nitr-oxides free radicals. A shift of the transition temperature with the magnetic field appears for the elastomers. The increasing paramagnetic shift has allowed a complete study by NMR of piperidinic and pyrrolidinic nitroxide free radicals. (author) [fr

  16. On the Fer expansion: Applications in solid-state nuclear magnetic resonance and physics

    Energy Technology Data Exchange (ETDEWEB)

    Mananga, Eugene Stephane, E-mail: esm041@mail.harvard.edu

    2016-01-18

    Theoretical approaches are useful and powerful tools for more accurate and efficient spin dynamics simulation to understand experiments and devising new RF pulse sequence in nuclear magnetic resonance. Solid-state NMR is definitely a timely topic or area of research, and not many papers on the respective theories are available in the literature of nuclear magnetic resonance or physics reports. This report presents the power and the salient features of the promising theoretical approach called Fer expansion that is helpful to describe the evolution of the spin system in nuclear magnetic resonance. The report presents a broad view of algorithms of spin dynamics based on the Fer expansion which provides procedures to control and describe the spin dynamics in solid-state NMR. Significant applications of the Fer expansion are illustrated in NMR and in physics such as classical physics, nonlinear dynamics systems, celestial mechanics and dynamical astronomy, hydrodynamics, nuclear, atomic, molecular physics, and quantum mechanics, quantum field theory, high energy physics, electromagnetism. The aim of this report is to bring to the attention of the spin dynamics community, the bridge that exists between solid-state NMR and other related fields of physics and applied mathematics.

  17. On the Floquet–Magnus expansion: Applications in solid-state nuclear magnetic resonance and physics

    Energy Technology Data Exchange (ETDEWEB)

    Mananga, Eugene Stephane, E-mail: emananga@gradcenter.cuny.edu [Harvard Medical School and Massachusetts General Hospital, Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging Physics, Department of Radiology, 55 Fruit Street, Boston, Massachusetts 02114 (United States); Charpentier, Thibault, E-mail: thibault.charpentier@cea.fr [Commissariat à l’Energie Atomique, IRAMIS, Service interdisciplinaire sur les systèmes moléculaires et matériaux, CEA/CNRS UMR 3299, 91191, Gif-sur-Yvette (France)

    2016-01-22

    Theoretical approaches are useful and powerful tools for more accurate and efficient spin dynamics simulation to understand experiments and devising new RF pulse sequence in nuclear magnetic resonance. Solid-state NMR is definitely a timely topic or area of research, and not many papers on the respective theories are available in the literature of nuclear magnetic resonance or physics reports. This report presents the power and the salient features of the promising theoretical approach called Floquet–Magnus expansion that is helpful to describe the time evolution of the spin system at all times in nuclear magnetic resonance. The report presents a broad view of algorithms of spin dynamics, based on promising and useful theory of Floquet–Magnus expansion. This theory provides procedures to control and describe the spin dynamics in solid-state NMR. Major applications of the Floquet–Magnus expansion are illustrated by simple solid-state NMR and physical applications such as in nuclear, atomic, molecular physics, and quantum mechanics, NMR, quantum field theory and high energy physics, electromagnetism, optics, general relativity, search of periodic orbits, and geometric control of mechanical systems. The aim of this report is to bring to the attention of the spin dynamics community, the bridge that exists between solid-state NMR and other related fields of physics and applied mathematics. This review article also discusses future potential theoretical directions in solid-state NMR.

  18. 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.

  19. Design of Matrix Shim Coils System for Nuclear magnetic resonance

    Czech Academy of Sciences Publication Activity Database

    Konzbul, Pavel; Švéda, Karel; Srnka, Aleš

    2000-01-01

    Roč. 36, č. 4 (2000), s. 1732-1735 ISSN 0018-9464. [COMPUMAG /12./. Sapporo, 25.10.1999-28.10.1999] R&D Projects: GA MŠk ME 181 Institutional research plan: CEZ:AV0Z2065902 Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.720, year: 2000

  20. 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...

  1. Development of Millimeter Wave Fabry-Pérot Resonator for Simultaneous Electron-Spin and Nuclear Magnetic Resonance Measurement

    Science.gov (United States)

    Ishikawa, Yuya; Ohya, Kenta; Fujii, Yutaka; Fukuda, Akira; Miura, Shunsuke; Mitsudo, Seitaro; Yamamori, Hidetomo; Kikuchi, Hikomitsu

    2018-04-01

    We report a Fabry-Pérot resonator with spherical and flat mirrors to allow simultaneous electron-spin resonance (ESR) and nuclear magnetic resonance (NMR) measurements that could be used for double magnetic resonance (DoMR). In order to perform simultaneous ESR and NMR measurements, the flat mirror must reflect millimeter wavelength electromagnetic waves and the resonator must have a high Q value ( Q > 3000) for ESR frequencies, while the mirror must simultaneously let NMR frequencies pass through. This requirement can be achieved by exploiting the difference of skin depth for the two frequencies, since skin depth is inversely proportional to the square root of the frequency. In consideration of the skin depth, the optimum conditions for conducting ESR and NMR using a gold thin film are explored by examining the relation between the Q value and the film thickness. A flat mirror with a gold thin film was fabricated by sputtering gold on an epoxy plate. We also installed a Helmholtz radio frequency coil for NMR and tested the system both at room and low temperatures with an optimally thick gold film. As a result, signals were obtained at 0.18 K for ESR and at 1.3 K for NMR. A flat-mirrored resonator with a thin gold film surface is an effective way to locate NMR coils closer to the sample being examined with DoMR.

  2. High temperature furnace for nuclear magnetic resonance experiments

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, C.; Scheler, G. (Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Sektion Physik)

    1984-01-01

    A furnace is described for NMR experiments in the temperature range 300 to 1,100 K. It can be used both in a superconducting solenoid (Oxford Instruments, B/sub 0/ = 6.4 T, bore 52 mm) and in iron magnets with a gap d >= 48 mm. All for NMR experiments important nuclei can be measured without /sup 29/Si. The NMR probe can be used both for instationary and stationary experiments.

  3. Evaluation of poly(vinylpyrrolidone) and collagen by Low Field Nuclear Magnetic Resonance Spectroscopy

    International Nuclear Information System (INIS)

    Costa, Paula de M.; Tavares, Maria I.B.

    2005-01-01

    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)

  4. Organic Pollutants in Soils, as Studied by Nuclear Magnetic Resonance

    Science.gov (United States)

    1998-05-15

    fundamental behaviors of certain organic pollutants (e.g., benzene, CC1, trichloroethylene, ethylene glycol) when adsorbed in typical soils , as...represented in most of this study by the ’ following major soil components: humics (humic acid, fulvic acid, humin ), clays (montmorillonite, kaolinite...239.18 Designed using Perform Pro, WHS/DIOR, Oct 94 • • 2 2 NAY m^ FINAL TECHNICAL REPORT ORGANIC POLLUTANTS IN SOILS , AS STUDIED BY NUCLEAR

  5. Method and apparatus for imaging substances in biological samples by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Shaw, D.

    1984-01-01

    A method of determining the distribution of non-proton nuclei having a magnetic moment in a biological sample is described. It comprises subjecting the sample to a magnetic field, irradiating the sample with RF radiation at a proton magnetic resonance frequency and deriving a first NMR signal, indicative of electromagnetic absorption of the sample at the proton magnetic resonance frequency. A second such NMR signal at the proton resonance frequency is then derived from the sample in the presence of RF radiation at the nuclear magnetic resonance frequency of the non-proton nuclei so as to decouple protons in the sample from the non-proton nuclei. By applying an imaging technique, an image indicative of the spatial variation of the difference between the first and second signals can be produced. Imaging may be performed on the difference between the two NMR signals, or on each NMR signal followed by subtraction of the images. The method can be used to trace how a 13 C-labelled material introduced into a patient, and its breakdown products, become distributed. (author)

  6. Zero Quantum Nuclear Magnetic Resonance experiments utilizing a toroid cell and coil

    OpenAIRE

    Bebout, William Roach

    1989-01-01

    Over the past ten to fifteen years the area of Nuclear Magnetic Resonance (NMR) Spectroscopy has seen tremendous growth. For example, in conjunction with multiple quantum NMR, molecular structural mapping of a compound can be easily performed in a two dimensional (2D) experiment. However, only two kinds of detector coils have been typically used in NMR studies. These are the solenoid coil and the Helmholtz coil. The solenoid coil was very popular with the permanent and e...

  7. 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).

  8. Theory and applications of maps on SO(3) in nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Cho, H.M.

    1987-02-01

    Theoretical approaches and experimental work in the design of multiple pulse sequences in Nuclear Magnetic Resonance (NMR) are the subjects of this dissertation. Sequences of discrete pulses which reproduce the nominal effect of single pulses, but over substantially broader, narrower, or more selective ranges of transition frequencies, radiofrequency field amplitudes, and spin-spin couplings than the single pulses they replace, are developed and demonstrated. 107 refs., 86 figs., 6 tabs

  9. Solid-state nuclear-spin quantum computer based on magnetic resonance force microscopy

    International Nuclear Information System (INIS)

    Berman, G. P.; Doolen, G. D.; Hammel, P. C.; Tsifrinovich, V. I.

    2000-01-01

    We propose a nuclear-spin quantum computer based on magnetic resonance force microscopy (MRFM). It is shown that an MRFM single-electron spin measurement provides three essential requirements for quantum computation in solids: (a) preparation of the ground state, (b) one- and two-qubit quantum logic gates, and (c) a measurement of the final state. The proposed quantum computer can operate at temperatures up to 1 K. (c) 2000 The American Physical Society

  10. S100 lathe bed pulse generator applied to pulsed nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Cernicchiaro, G.R.C.; Rudge, M.G.; Albuquerque, M.P.

    1989-01-01

    The project and construction of four channel pulse generator in the S100 standard plate and its control software for microcomputer are described. The microcomputer has total control on the pulse generator, which has seven programable parameters, defining the position of four pulses and the width for the three first ones. This pulse generator is controlled by a software developed in c language, and is used in pulsed nuclear magnetic resonance experiences. (M.C.K.) [pt

  11. Advantages and disadvantages of nuclear magnetic resonance spectroscopy as a hyphenated technique

    International Nuclear Information System (INIS)

    Silva Elipe, Maria Victoria

    2003-01-01

    A general overview of the advancements and applications of nuclear magnetic resonance (NMR) hyphenated with other analytical techniques is given from a practical point of view. Details on the advantages and disadvantages of the hyphenation of NMR with liquid chromatography as LC-NMR and also with mass spectrometry as LC-MS-NMR are demonstrated with two examples. Current developments of NMR with other analytical separation techniques, especially with capillary liquid chromatography (capLC) are discussed

  12. Characterisation by nuclear magnetic resonance of the β catalytic subunit of the chloroplastic coupling factor

    International Nuclear Information System (INIS)

    Andre, Francois

    1986-09-01

    This academic work addressed the use of nuclear magnetic resonance (NMR) for the structural and dynamic study of the catalytic sub-unit of the extrinsic section of a membrane complex, the chloroplastic H+-ATPase. This work included the development of a protocol of preparation and quantitative purification of β subunits isolated from the CF1 for the elaboration of a concentrated sample for NMR, and then the study of the β subunit by using proton NMR

  13. Pulsed-field gradient nuclear magnetic resonance study of transport properties of fluid catalytic cracking catalysts

    Czech Academy of Sciences Publication Activity Database

    Kortunov, P.; Vasenkov, S.; Kärger, J.; Fé Elía, M.; Perez, M.; Stöcker, M.; Papadopoulos, G. K.; Theodorou, D.; Drescher, B.; McElhiney, G.; Bernauer, B.; Krystl, V.; Kočiřík, Milan; Zikánová, Arlette; Jirglová, Hana; Berger, C.; Gläser, R.; Weitkamp, J.; Hansen, E. W.

    2005-01-01

    Roč. 23, č. 2 (2005), s. 233-237 ISSN 0730-725X Grant - others:TROCAT project - European Community(DE) G5RD-CT-2001-00520 Institutional research plan: CEZ:AV0Z40400503 Keywords : pulsed-field gradient * nuclear magnetic resonance * fluid catalytic cracking catalyst Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.361, year: 2005

  14. Display of cross sectional anatomy by nuclear magnetic resonance imaging. 1978.

    Science.gov (United States)

    Hinshaw, W S; Andrew, E R; Bottomley, P A; Holland, G N; Moore, W S

    1995-12-01

    High definition cross-sectional images produced by a new nuclear magnetic resonance (NMR) technique are shown. The images are a series of thin section scans in the coronal plane of the head of a rabbit. The NMR images are derived from the distribution of the density of mobile hydrogen atoms. Various tissue types can be distinguished and a clear registration of gross anatomy is demonstrated. No known hazards are associated with the technique.

  15. Proceedings of the 37. Polish Seminar on Nuclear Magnetic Resonance and its Applications

    International Nuclear Information System (INIS)

    2004-11-01

    37. Polish Seminar on Nuclear Magnetic Resonance and Its Applications is Cyclically organised forum for discussing the actual problems, achievements and perspectives of methodology and interpretation of NMR. At presenting edition the problems of NMR imaging in medicine diagnostics, studies of biologically important organic molecules as well as inorganic compounds being interesting for microelectronics and catalysis have been especially emphasized. The progress in computerized simulation for NMR spectra interpretation has been also performed in numerous presentations

  16. Carbon and deuterium nuclear magnetic resonance in solids

    Energy Technology Data Exchange (ETDEWEB)

    Shattuck, Thomas Wayne [Univ. of California, Berkeley, CA (United States)

    1976-07-01

    In Chapter I we present the results on a study of cross polarization dynamics, between protons and carbon-13 in adamantane, by the direct observation of the dilute, carbon-13, spins. These dynamics are an important consideration in the efficiency of proton enhancement double-resonance techniques and they also provide good experimental models for statistical theories of cross relaxation. In order to test these theories we present a comparison of the experimental and theoretical proton dipolar fluctuation correlation time τc, which is experimentally 110 ± 15 μsec and theoretically 122 μsec for adamantane. These double resonance considerations provide the background for extensions to deuterium and double quantum effects discussed in Chapter II. In Chapter II an approach to high resolution nmr of deuterium in solids is described. The m = 1 → -1 transition is excited by a double quantum process and the decay of coherence Q(τ) is monitored. Fourier transformation yields a deuterium spectrum devoid of quadrupole splittings and broadening. If the deuterium nuclei are dilute and the protons are spin decoupled, the double-quantum spectrum is a high resolution one and yields information on the deuterium chemical shifts Δω. The relationship Q(τ) ~ cos 2Δωτ is checked and the technique is applied to a single crystal of oxalic acid dihydrate enriched to ~ 10% in deuterium. The carboxyl and the water deuterium shifts are indeed resolved and the anisotropy of the carboxyl shielding tensor is estimated to be Δσ = 32 ± 3 ppm. A complete theoretical analysis is presented. The extension of cross relaxation techniques, both direct and indirect, to proton-deuterium double resonance is also described. The m = 1 → -1 double quantum transition and the m = ± 1 → 0 single quantum transitions may all be polarized and we present the derivation of the Hartmann-Hahn cross polarization conditions for each case. In addition the dynamics of the double quantum process

  17. On the feasibility of neurocurrent imaging by low-field nuclear magnetic resonance

    Science.gov (United States)

    Burghoff, Martin; Albrecht, Hans-Helge; Hartwig, Stefan; Hilschenz, Ingo; Körber, Rainer; Höfner, Nora; Scheer, Hans-Jürgen; Voigt, Jens; Trahms, Lutz; Curio, Gabriel

    2010-06-01

    We describe a nuclear magnetic resonance (NMR) spectrometer operating at 20 μT with a frequency resolution of 2 mHz to determine the intrinsic linewidth of the proton resonance in the human brain to be about 3 Hz. Using the same system we measured a biomagnetic field of 0.5 to 1 pT amplitude, which was generated by sustained brain activity evoked during repetitive median nerve stimulation. From these data, the effect of neuronal currents on the proton NMR signal was estimated. We conclude that neuronal currents may cause a measurable shift of the proton NMR line of brain tissue in low-fields.

  18. The Co59 nuclear magnetic resonances in (Ysub(1-x)Gdsub(x))2Co17

    International Nuclear Information System (INIS)

    Nagai, Hiroyuki; Yoshie, Hiroshi; Unate, Takao; Tsujimura, Akira; Deportes, J.

    1976-01-01

    The nuclear magnetic resonances of Co 59 in (Ysub(1-x)Gdsub(x)) 2 Co 17 have been observed at 77 K as a function of x (0 2 Co 17 and Gd 2 Co 17 is at most 7 kOe in magnitude, which is comparable to that obtained in GdCo 5 . The sign of the obtained difference depends on the Co sites. The difference is qualitatively explained as the contribution of 4f electrons of Gd atoms to the hyperfine field. The temperature dependence of the resonance frequencies in Gd 2 Co 17 has also been measured. (auth.)

  19. Quantitative dosing by nuclear magnetic resonance; Dosages quantitatifs par resonance magnetique nucleaire

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, I. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The measurement of the absolute concentration of a heavy water reference containing approximately 99.8 per cent of D{sub 2}O has been performed, by an original magnetic resonance method ('Adiabatic fast passage method') with a precision of 5.10{sup -5} on the D{sub 2}O concentration. (author) [French] La determination du titre absolu d'une eau lourde etalon de teneur approximative de 99,8 pour cent de D{sub 2}O a pu etre effectuee par une methode originale de resonance magnetique ('Methode de passage rapide adiabatique') a une precision de 5.10{sup -5} sur le titre de D{sub 2}O. (auteur)

  20. Acoustic resonance spectroscopy intrinsic seals

    International Nuclear Information System (INIS)

    Olinger, C.T.; Burr, T.; Vnuk, D.R.

    1994-01-01

    We have begun to quantify the ability of acoustic resonance spectroscopy (ARS) to detect the removal and replacement of the lid of a simulated special nuclear materials drum. Conceptually, the acoustic spectrum of a container establishcs a baseline fingerprint, which we refer to as an intrinsic seal, for the container. Simply removing and replacing the lid changes some of the resonant frequencies because it is impossible to exactly duplicate all of the stress patterns between the lid and container. Preliminary qualitative results suggested that the ARS intrinsic seal could discriminate between cases where a lid has or has not been removed. The present work is directed at quantifying the utility of the ARS intrinsic seal technique, including the technique's sensitivity to ''nuisance'' effects, such as temperature swings, movement of the container, and placement of the transducers. These early quantitative tests support the potential of the ARS intrinsic seal application, but also reveal a possible sensitivity to nuisance effects that could limit environments or conditions under which the technique is effective

  1. 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.

  2. Two-dimensional nuclear magnetic resonance studies of molecular structure in liquids and liquid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Rucker, S.P.

    1991-07-01

    Magnetic couplings between protons, such as through-space dipole couplings, and scalar J-couplings depend sensitively on the structure of the molecule. Two dimensional nuclear magnetic resonance experiments provide a powerful tool for measuring these couplings, correlating them to specific pairs of protons within the molecule, and calculating the structure. This work discusses the development of NMR methods for examining two such classes of problems -- determination of the secondary structure of flexible molecules in anisotropic solutions, and primary structure of large biomolecules in aqueous solutions. 201 refs., 84 figs., 19 tabs.

  3. Electromagnetic Properties of Inner Double Walled Carbon Nanotubes Investigated by Nuclear Magnetic Resonance

    Directory of Open Access Journals (Sweden)

    M. Bouhrara

    2013-01-01

    Full Text Available 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 C60 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.

  4. A two-axis goniometer for low-temperature nuclear magnetic resonance measurements on single crystals.

    Science.gov (United States)

    Shiroka, T; Casola, F; Mesot, J; Bachmann, W; Ott, H-R

    2012-09-01

    We report on the construction of a two-axis goniometer intended for low-temperature, single-crystal nuclear magnetic resonance (NMR) measurements. With the use of home-made and commercially available parts, our simple probe-head design achieves good sensitivity, while maintaining a high angular precision and the ability to orient samples also when cooled to liquid helium temperatures. The probe with the goniometer is adapted to be inserted into a commercial (4)He-flow cryostat, which fits into a wide-bore superconducting solenoid magnet. Selected examples of NMR measurements illustrate the operation of the device.

  5. 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...... in Xe gas. Our best results, obtained with the piecewise approximation for the binary chemical shift combined with the previously published state of the art theoretical potential energy curve for Xe2, are in excellent agreement with the experiment for the first time. © 2007 American Institute of Physics...

  6. Longitudinal nuclear magnetic resonance of 3He-B superfluid

    International Nuclear Information System (INIS)

    Vibet, Claude.

    1979-06-01

    Experiments which contribute to a better understanding of the 3 He superfluid in the B phase are reported: a/ The first direct determinations of the gap parameter at zero temperature are given and the longitudinal N.M.R. frequency signal is measured for various pressures. b/ These experiments show a new saturation phenomenon in the ringing signal decay time Tsub(R)(T) at low temperatures. c/ Under conditions of slight non-linearity the excitation of 3 He-B longitudinal N.M.R. gives rise to a special system wherein the ringing signal decay is all the faster as the excitation is stronger. A so-called ''memory'' time is measured distinctly longer than the ringing time measured under quasi-linear excitation conditions. It was found that the ringing signal decay, at first exponential for weak excitations γH 1 approximately 7 10 -3 Ωsub(L), becomes quasi-linear when the excitation is about γH 1 approximately 10 -2 Ωsub(L). This abnormal behaviour cannot be explained by thermal effects related to N.M.R. excitation nor by inhomogeneity effects of the excitation magnetic field. Our interpretation is that excitations γH 1 approximately 10 -2 Ωsub(L) cause structural defects in the orientation of the vector n which are found to disappear according to an exponential law in times of around 10 ms [fr

  7. Magnetic resonance of phase transitions

    CERN Document Server

    Owens, Frank J; Farach, Horacio A

    1979-01-01

    Magnetic Resonance of Phase Transitions shows how the effects of phase transitions are manifested in the magnetic resonance data. The book discusses the basic concepts of structural phase and magnetic resonance; various types of magnetic resonances and their underlying principles; and the radiofrequency methods of nuclear magnetic resonance. The text also describes quadrupole methods; the microwave technique of electron spin resonance; and the Mössbauer effect. Phase transitions in various systems such as fluids, liquid crystals, and crystals, including paramagnets and ferroelectrics, are also

  8. Structural characterization by Nuclear Magnetic Resonance of ozonized triolein

    Directory of Open Access Journals (Sweden)

    F. Díaz, Maritza

    2008-09-01

    Full Text Available In the present study ozonized triolein with 739 mmolequiv/ kg peroxide index is characterized by NMR.The triolein and ozonized triolein show very similar 1H NMR spectra except for the resonances at δ 9.74 ppm, which correspond to aldehydic protons and δ 5.14 ppm (ozonides methylic protons. Other new signal assignments are based on the connectivities provided by the proton scalar coupling constants δ 2.41 ppm (methylenic group allylic to aldehydic protons and ozonides methynic protons and δ 1.67 ppm (methylenic protons in position with respect to ozonides methylic protons. From the 13C and 1H-13C spectrum of the ozonized triolein, the presence of ozonides was confirmed by the signals δ 104.2 and 104.3 ppm, respectively. Other new signals in δ 43.9 ppm confirm the presence of methylenic carbon ozonides. From the structural elucidation of ozonated triglycerides, relevant chemical information about ozonated vegetable oil can be found .En el presente estudio ha sido caracterizada por RMN la trioleina ozonizada con índice de peróxidos de 739 mmolequiv/ kg. La trioleina y la trioleina ozonizada muestran espectros muy similares exceptuando los valores de las resonancias δ 9,74 ppm de los protones aldehídicos, y δ 5,14 ppm (protones metínicos de los ozónidos. Otras nuevas asignaciones fueron basadas en las conectividades obtenidas por las constantes de acoplamiento escalar como δ 2,41 ppm (grupo metilénico alilico a los protones aldehídicos y protones metínicos de los ozónidos y δ 1,67 ppm (protones metilénicos en posición βcon respecto a los protones metínicos de los ozónidos. En los espectros 13C y 1H-13C de la trioleina ozonizada la presencia de ozónidos fue atribuida, respectivamente, por las señales δ 104,2 y δ 104,3 ppm. Una nueva señal en δ 43,9 ppm confirma la presencia de carbono metilénico de ozónidos. Estos resultados indican que la elucidación estructural de triglicéridos ozonizados, ofrece información qu

  9. Mathematical Development and Computational Analysis of Harmonic Phase-Magnetic Resonance Imaging (HARP-MRI) Based on Bloch Nuclear Magnetic Resonance (NMR) Diffusion Model for Myocardial Motion.

    Science.gov (United States)

    Dada, Michael O; Jayeoba, Babatunde; Awojoyogbe, Bamidele O; Uno, Uno E; Awe, Oluseyi E

    2017-09-13

    Harmonic Phase-Magnetic Resonance Imaging (HARP-MRI) is a tagged image analysis method that can measure myocardial motion and strain in near real-time and is considered a potential candidate to make magnetic resonance tagging clinically viable. However, analytical expressions of radially tagged transverse magnetization in polar coordinates (which is required to appropriately describe the shape of the heart) have not been explored because the physics required to directly connect myocardial deformation of tagged Nuclear Magnetic Resonance (NMR) transverse magnetization in polar geometry and the appropriate harmonic phase parameters are not yet available. The analytical solution of Bloch NMR diffusion equation in spherical geometry with appropriate spherical wave tagging function is important for proper analysis and monitoring of heart systolic and diastolic deformation with relevant boundary conditions. In this study, we applied Harmonic Phase MRI method to compute the difference between tagged and untagged NMR transverse magnetization based on the Bloch NMR diffusion equation and obtained radial wave tagging function for analysis of myocardial motion. The analytical solution of the Bloch NMR equations and the computational simulation of myocardial motion as developed in this study are intended to significantly improve healthcare for accurate diagnosis, prognosis and treatment of cardiovascular related deceases at the lowest cost because MRI scan is still one of the most expensive anywhere. The analysis is fundamental and significant because all Magnetic Resonance Imaging techniques are based on the Bloch NMR flow equations.

  10. Pre-polarization enhancement by dynamic nuclear polarization in SQUID-based ultra-low-field nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seong-Joo; Kim, Kiwoong; Kang, Chan Seok; Hwang, Seong-min; Lee, Yong-Ho, E-mail: kwkim@kriss.re.k [Brain and Cognition Measurement Laboratory, Korea Research Institute of Standards and Science (KRISS), Doryong-dong, Yuseong-gu, Daejeon 305-340 (Korea, Republic of)

    2010-11-15

    We achieved enhanced pre-polarization in a superconducting quantum interference device (SQUID)-based microtesla nuclear magnetic resonance (NMR) experiment by using dynamic nuclear polarization (DNP). The pre-polarization field is necessary to provide enough signal to noise to perform SQUID-based ultra-low-field (ULF) NMR/magnetic resonance imaging (MRI) experiments. However, it is quite tricky to deal with the strong transient magnetic field when operating the SQUID in a magnetically shielded room (MSR); besides the direct interference with the sensitive SQUID sensor, the strong magnetic field and its abrupt change generate magnetization in local areas in the MSR and eddy currents along the wall, which makes the NMR measurement difficult. The enhanced {sup 1}H NMR signals of water in TEMPOL and TEMPO solutions were obtained with a relatively weak radio-frequency (rf) field and double-relaxation oscillation SQUIDs (DROS) at a few mT pre-polarization fields. In our experimental condition, the enhancement factor was near ten in spite of the rf power far below the saturation in both samples.

  11. Pre-polarization enhancement by dynamic nuclear polarization in SQUID-based ultra-low-field nuclear magnetic resonance

    Science.gov (United States)

    Lee, Seong-Joo; Kim, Kiwoong; Kang, Chan Seok; Hwang, Seong-min; Lee, Yong-Ho

    2010-11-01

    We achieved enhanced pre-polarization in a superconducting quantum interference device (SQUID)-based microtesla nuclear magnetic resonance (NMR) experiment by using dynamic nuclear polarization (DNP). The pre-polarization field is necessary to provide enough signal to noise to perform SQUID-based ultra-low-field (ULF) NMR/magnetic resonance imaging (MRI) experiments. However, it is quite tricky to deal with the strong transient magnetic field when operating the SQUID in a magnetically shielded room (MSR); besides the direct interference with the sensitive SQUID sensor, the strong magnetic field and its abrupt change generate magnetization in local areas in the MSR and eddy currents along the wall, which makes the NMR measurement difficult. The enhanced 1H NMR signals of water in TEMPOL and TEMPO solutions were obtained with a relatively weak radio-frequency (rf) field and double-relaxation oscillation SQUIDs (DROS) at a few mT pre-polarization fields. In our experimental condition, the enhancement factor was near ten in spite of the rf power far below the saturation in both samples.

  12. Advances in magnetic resonance 11

    CERN Document Server

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 11, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains three chapters and begins with a discussion of the principles and applications of dynamic nuclear polarization, with emphasis on molecular motions and collisions, intermolecular couplings, and chemical interactions. Subsequent chapters focus on the assessment of a proposed broadband decoupling method and studies of time-domain (or Fourier transform) multiple-quantum nuclear magnetic resonance.

  13. Impact of acoustic window on accuracy of longitudinal global strain: a comparison study to cardiac magnetic resonance.

    Science.gov (United States)

    Macron, Laurent; Lairez, Olivier; Nahum, Julien; Berry, Mathieu; Deal, Leslie; Deux, Jean-François; Bensaid, Alexandre; Dubois Randé, Jean-Luc; Gueret, Pascal; Lim, Pascal

    2011-05-01

    To evaluate the impact of acoustic window on the feasibility and accuracy of longitudinal global strain (global-ε) by speckle tracking for assessing left ventricular (LV) systolic function. The study included 70 patients (57 ± 17 years, 64% men), 28 selected patients with a suboptimal image quality (IQ) defined by three or more segments (4 ± 3 segments/patient) with wall motion score not analysable visually and 42 patients with an optimal two-dimensional (2D) echocardiography IQ. Left ventricular ejection fraction (LVEF) by Simpson's biplane method (2D-EF), global-ε by speckle tracking, and peak systolic mitral annulus velocity [systolic tissue Doppler imaging (S-TDI)] were compared with LVEF by cardiac magnetic resonance (EF-CMR; 45 ± 18%, range 9-76%). Speckle-tracking analysis was feasible in all segments with an optimal acoustic window and in 85% (103/121) of segments poorly visualized. Global-ε similarly correlated with LVEF by CMR in patients with and without optimal IQ (r = 0.81 vs. 0.82 for good vs. poor IQ). In contrast, 2D-EF (r = 0.76) and S-TDI (r = 0.64) less correlated with LVEF by CMR in patients with a suboptimal IQ. Importantly, IQ only impacted on 2D-EF inter-observer reproducibility (9 ± 5 vs. 24 ± 22% for good vs. poor IQ) but not on global-ε reproducibility (9 ± 1 vs. 8 ± 7% for good vs. poor IQ). In patients with a limited acoustic window, longitudinal strain by speckle tracking remains accurate and reproducible for assessing global and regional LV systolic function.

  14. Assessment of tumor energy and oxygenation status by bioluminescence, nuclear magnetic resonance spectroscopy, and cryospectrophotometry.

    Science.gov (United States)

    Mueller-Klieser, W; Schaefer, C; Walenta, S; Rofstad, E K; Fenton, B M; Sutherland, R M

    1990-03-15

    The energy and oxygenation status of tumors from two murine sarcoma lines (KHT, RIF-1) and two human ovarian carcinoma xenograft lines (MLS, OWI) were assessed using three independent techniques. Tumor energy metabolism was investigated in vivo by 31P nuclear magnetic resonance spectroscopy. After nuclear magnetic resonance measurements, tumors were frozen in liquid nitrogen to determine the tissue ATP concentration by imaging bioluminescence and to register the intracapillary oxyhemoglobin (HbO2) saturation using the cryospectrophotometric method. There was a positive correlation between the nucleoside triphosphate beta/total resonance ratio or a negative correlation between the Pi/total resonance ratio and the model ATP concentration obtained by bioluminescence, respectively. This was true for small tumors with no extended necrosis irrespective of tumor type. Moreover, a positive correlation was obtained between the HbO2 saturations and the ATP concentration measured with bioluminescence. The results demonstrate the potential of combined studies using noninvasive, integrating methods and high-resolution imaging techniques for characterizing the metabolic milieu in tumors.

  15. Motor circuit computer model based on studies of functional Nuclear Magnetic Resonance

    International Nuclear Information System (INIS)

    Garcia Ramo, Karla Batista; Rodriguez Rojas, Rafael; Carballo Barreda, Maylen

    2012-01-01

    The basal ganglia are a complex network of subcortical nuclei involved in motor control, sensorimotor integration, and cognitive processes. Their functioning and interaction with other cerebral structures remains as a subject of debate. The aim of the present work was to simulate the basal ganglia-thalamus-cortex circuitry interaction in motor program selection, supported by functional connectivity pattern obtained by functional nuclear magnetic resonance imaging. Determination of connections weights between neural populations by functional magnetic resonance imaging, contributed to a more realistic formulation of the model; and consequently to obtain similar results to clinical and experimental data. The network allowed to describe the participation of the basal ganglia in motor program selection and the changes in Parkinson disease. The simulation allowed to demonstrate that dopamine depletion above to 40 % leads to a loss of action selection capability, and to reflect the system adaptation ability to compensate dysfunction in Parkinson disease, coincident with experimental and clinical studies

  16. 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.

  17. Magnetic Resonance Facility (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-03-01

    This fact sheet provides information about Magnetic Resonance Facility capabilities and applications at NREL's National Bioenergy Center. Liquid and solid-state analysis capability for a variety of biomass, photovoltaic, and materials characterization applications across NREL. NREL scientists analyze solid and liquid samples on three nuclear magnetic resonance (NMR) spectrometers as well as an electron paramagnetic resonance (EPR) spectrometer.

  18. Nuclear magnetic resonance common laboratory, quadrennial report; Laboratoire commun de resonance magnetique nucleaire, rapport quadriennal 1994-1997

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

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

  19. Proton nuclear magnetic resonance studies on the variant-3 neurotoxin from Centruroides sculpturatus Ewing: Sequential assignment of resonances

    International Nuclear Information System (INIS)

    Nettesheim, D.G.; Klevit, R.E.; Drobny, G.; Watt, D.D.; Krishna, N.R.

    1989-01-01

    The authors report the sequential assignment of resonances to specific residues in the proton nuclear magnetic resonance spectrum of the variant-3 neurotoxin from the scorpion Centruroides sculpturatus Ewing (range southwestern U.S.A.). A combination of two-dimensional NMR experiments such as 2D-COSY, 2D-NOESY, and single- and double-RELAY coherence transfer spectroscopy has been employed on samples of the protein dissolved in D 2 O and in H 2 O for assignment purposes. These studies provide a basis for the determination of the solution-phase conformation of this protein and for undertaking detailed structure-function studies of these neurotoxins that modulate the flow of sodium current by binding to the sodium channels of excitable membranes

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

    Science.gov (United States)

    Meier, Thomas; Herzig, Tobias; Haase, Jürgen

    2014-04-01

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

  1. 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.

  2. Advances in magnetic resonance 12

    CERN Document Server

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 12, presents a variety of contributions to the theory and practice of magnetic resonance. The book contains six chapters and begins with a discussion of diffusion and self-diffusion measurements by nuclear magnetic resonance. This is followed by separate chapters on spin-lattice relaxation time in hydrogen isotope mixtures; the principles of optical detection of nuclear spin alignment and nuclear quadropole resonance; and the spin-1 behavior, including the relaxation of the quasi-invariants of the motion of a system of pairs of dipolar coupled spin-1/2 nu

  3. 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. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. MRI (Magnetic Resonance Imaging)

    Science.gov (United States)

    ... Medical Imaging MRI (Magnetic Resonance Imaging) MRI (Magnetic Resonance Imaging) Share Tweet Linkedin Pin it More sharing options Linkedin Pin it Email Print Magnetic Resonance Imaging (MRI) is a medical imaging procedure for ...

  5. Dynamic Nuclear Polarization at low temperature and high magnetic eld for biomedical applications in Magnetic Resonance Spectroscopic Imaging

    International Nuclear Information System (INIS)

    Goutailler, Florent

    2011-01-01

    The aim of this thesis work was to design, build and optimize a large volume multi-samples DNP (Dynamic Nuclear Polarization) polarizer dedicated to Magnetic Resonance Spectroscopic Imaging applications. The experimental system is made up of a high magnetic field magnet (3,35 T) in which takes place a cryogenic system with a pumped bath of liquid helium ( 4 He) allowing temperatures lower than 1,2 K. A set of inserts is used for the different steps of DNP: irradiation of the sample by a microwave field (f=94 GHz and P=50 mW), polarization measurement by Nuclear Magnetic Resonance... With this system, up to three samples of 1 mL volume can be polarized to a rate of few per-cents. The system has a long autonomy of four hours, so it can be used for polarizing molecules with a long time constant of polarization. Finally, the possibility to get quasi-simultaneously, after dissolution, several samples with a high rate of polarization opens the way of new applications in biomedical imaging. (author) [fr

  6. Detection of nuclear magnetic resonance in the microtesla range using a high Tc dc-SQUID

    International Nuclear Information System (INIS)

    Wang Ning; Jin Yirong; Li Shao; Ren Yufeng; Tian Ye; Chen Yingfei; Li Jie; Chen Genghua; Zheng Dongning

    2012-01-01

    We have detected the ultra-low field nuclear magnetic resonance signal from water samples using a high-T c dc-SQUID sensor. The measurements were carried out in a homemade magnetically shielded room. Resonance spectra of 1 H from tap water and other substance samples were obtained in the field range from 7-110μT corresponding to resonance frequency 300-4.68kHz. Two kind of experimental systems were built, the first one is a directly coupled system, its signal to noise ratio in a single-shot measurement is around 4 for about 15 ml water. The second one used a Cu coil to transfer the flux to the SQUID sensor. Signal to noise ratio was improved to about 20 in a single-shot measurement for 5ml water, which benefits from the improvement of coupling efficiency. The effect of residual gradient in the magnetically shielded room was also investigated. J-coupling of 2,2,2-Trifluoroethyl alcohol was measured, the peaks are consistent with high field results.

  7. 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.

  8. Detection of nuclear magnetic resonance in the microtesla range using a high Tc dc-SQUID

    Science.gov (United States)

    Wang, Ning; Jin, Yirong; Li, Shao; Ren, Yufeng; Tian, Ye; Chen, Yingfei; Li, Jie; Chen, Genghua; Zheng, Dongning

    2012-12-01

    We have detected the ultra-low field nuclear magnetic resonance signal from water samples using a high-Tc dc-SQUID sensor. The measurements were carried out in a homemade magnetically shielded room. Resonance spectra of 1H from tap water and other substance samples were obtained in the field range from 7-110μT corresponding to resonance frequency 300-4.68kHz. Two kind of experimental systems were built, the first one is a directly coupled system, its signal to noise ratio in a single-shot measurement is around 4 for about 15 ml water. The second one used a Cu coil to transfer the flux to the SQUID sensor. Signal to noise ratio was improved to about 20 in a single-shot measurement for 5ml water, which benefits from the improvement of coupling efficiency. The effect of residual gradient in the magnetically shielded room was also investigated. J-coupling of 2,2,2-Trifluoroethyl alcohol was measured, the peaks are consistent with high field results.

  9. 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.

  10. Increase of the assistancial productivity of the nuclear magnetic resonance equipment TOMIKON BMT 1100

    International Nuclear Information System (INIS)

    Rodriguez, A.; Carbonell, G.; Hernandez, C.

    1992-01-01

    In the present work a revision of the physical parameters which take part in the obtained of the Nuclear Magnetic Resonance (NMR) is carried put. Image is obtained introducing changes on them given in the disminution of the matrix size from 256 x 256 to 128 pixels with the corresponding disminution of FOV in dependence of the analized region, showing theoretical and practically its great importance of the number of possible examination with the resulting augment of the productivity of the method and the possibility to carried out studies on little cooperative patients mantaining an adequate quality and diagnostic information of the images

  11. 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.

  12. Realization of quantum state privacy amplification in a nuclear magnetic resonance quantum system

    International Nuclear Information System (INIS)

    Hao, Liang; Wang, Chuan; Long, Gui Lu

    2010-01-01

    Quantum state privacy amplification (QSPA) is the quantum analogue of classical privacy amplification. If the state information of a series of single-particle states has some leakage, QSPA reduces this leakage by condensing the state information of two particles into the state of one particle. Recursive applications of the operations will eliminate the quantum state information leakage to a required minimum level. In this paper, we report the experimental implementation of a quantum state privacy amplification protocol in a nuclear magnetic resonance system. The density matrices of the states are constructed in the experiment, and the experimental results agree well with theory.

  13. 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...... divided into groups of three and each group was saturated either with deionized water, calcite equilibrated water, or sodium chloride, magnesium chloride and calcium chloride solutions of the same ionic strength. Saturation with solutions that contain divalent ions caused major shifts in the distribution...

  14. Time domain-nuclear magnetic resonance study of chars from southern hardwoods

    International Nuclear Information System (INIS)

    Elder, Thomas; Labbe, Nicole; Harper, David; Rials, Timothy

    2006-01-01

    Chars from the thermal degradation of silver maple (Acer saccharinum), red maple (Acer rubrum), sugar maple (Acer saccharum), and white oak (Quercus spp.), performed at temperatures from 250 to 350 o C, were examined using time domain-nuclear magnetic resonance spectroscopy. Prior to analysis, the chars were equilibrated under conditions insuring the presence of bound water only and both bound water and free water. Transverse relaxation times were found to be related to the moisture content of the chars, which varied with temperature. At elevated temperatures the number of signals assigned to free water decreased, indicative of an increase in pore size within the chars

  15. 1H nuclear magnetic resonance study of hydrated water dynamics in perfluorosulfonic acid ionomer Nafion

    International Nuclear Information System (INIS)

    Han, Jun Hee; Lee, Kyu Won; Jeon, G. W.; Lee, Cheol Eui; Park, W. K.; Choi, E. H.

    2015-01-01

    We have studied the dynamics of hydrated water molecules in the proton exchange membrane of Nafion by means of high-resolution 1 H nuclear magnetic resonance (NMR) measurements. “Bound” and “free” states of hydrated water clusters as well as the exchange protons were identified from the NMR chemical shift measurements, and their activation energies were obtained from the temperature-dependent laboratory- and rotating-frame spin-lattice relaxation measurements. Besides, a peculiar motional transition in the ultralow frequency region was observed at 373 K for the “free” hydrated water from the rotating-frame NMR spin-lattice relaxation time measurements

  16. Development of Nuclear Magnetic Resonance Imaging/spectroscopy for improved petroleum recovery. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barrufet, M.A.; Flumerfelt, F.W.; Walsh, M.P.; Watson, A.T.

    1994-04-01

    The overall objectives of this program are to develop and apply Nuclear Magnetic Resonance Imaging (NMRI) and CT X-Ray Scanning methods for determining rock, fluid, and petrophysical properties and for fundamental studies of multiphase flow behavior in porous media. Specific objectives are divided into four subtasks: (1) development of NMRI and CT scanning for the determination of rock-fluid and petrophysical properties; (2) development of NMRI and CT scanning for characterizing conventional multiphase displacement processes; (3) development of NMR and CT scanning for characterizing dispersed phase processes; and (4) miscible displacement studies.

  17. Quantification of Squalene in Olive Oil Using 13C Nuclear Magnetic Resonance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Anne-Marie Nam

    2017-11-01

    Full Text Available In the course of our ongoing work on the chemical characterization of Corsican olive oil, we have developed and validated a method for direct quantification of squalene using 13C Nuclear Magnetic Resonance (NMR spectroscopy without saponification, extraction, or fractionation of the investigated samples. Good accuracy, linearity, and precision of the measurements have been observed. The experimental procedure was applied to the quantification of squalene in 24 olive oil samples from Corsica. Squalene accounted for 0.35–0.83% of the whole composition.

  18. Chemical characterization of pigment gallstones using 13C nuclear magnetic resonance analysis

    International Nuclear Information System (INIS)

    Woolfenden, W.R.; Grant, D.M.; Straight, R.C.; Englert, E. Jr.

    1982-01-01

    The unique ability of Carbon-13 nuclear magnetic resonance analysis with cross polarization/magic angle spinning techniques to investigate chemical structures of solids is used to probe the chemical characteristics of several gallstone types. New pulse program techniques are used to distinguish various carbon atoms in studying the polymeric nature of the black bilirubinoid pigment of pigment gallstones. Evidence for the involvement of the carboxyl group and noninvolvement of vinyl groups of bilirubinoids in the polymeric bond formation is presented. Conjugated bilirubin structures are found to be present in some solid residues from pigment stones extracted with acidic methanol/chloroform

  19. Material degradation of liquid organic semiconductors analyzed by nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Tatsuya; Yamamoto, Junichi; Fukuchi, Masashi; Kaji, Hironori, E-mail: kaji@scl.kyoto-u.ac.jp [Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011 (Japan); Hirata, Shuzo; Jung, Heo Hyo; Adachi, Chihaya [Center for Organic Photonics and Electronics Research (OPERA), Kyusyu University, 744 Motooka, Nishi, Fukuoka 819-0395 (Japan); Hirata, Osamu; Shibano, Yuki [Nissan Chemical Industries, LTD, 722-1 Tsuboi, Funabashi 274-8507 (Japan)

    2015-08-15

    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.

  20. Immediate analysis of the oil content of seeds by carbon-13 nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Leal, K.Z.; Costa, V.E.U.; Seidl, P.R.; Campos, M.P.A.; Colnago, L.A.

    1981-01-01

    The carbon 13 nuclear magnetic resonance (CMR) spectra of a series of Brazilian oilseeds was registered. The main constituents of the oils are identified and signals for each carbon atom are assigned. Chemical shifts are estimated for the free fatty acids and compared to those observed from the seeds, with good results. Besides being non-destructive, the RMC method proves to be fast and is useful in the determination of the principal components of the oil fraction of different types of seeds. (Author) [pt

  1. A compact Class D RF power amplifier for mobile nuclear magnetic resonance systems

    Science.gov (United States)

    Zhen, J.; Dykstra, R.; Eccles, C.; Gouws, G.; Obruchkov, S.

    2017-07-01

    A 20 MHz Class D amplifier with an output of 100 W of RF power has been developed. The compact size printed circuit board area of 50 cm2 and efficiency of 73% make it suitable for mobile nuclear magnetic resonance (NMR) systems. Test results show that the rise and ring down times of the amplifier are less than 0.2 μs, and it is capable of producing constant amplitude pulses as short as 2 μs. Experiments using a Carr Purcell Meiboom Gill pulse sequence with a NMR MOUSE sensor confirm that the Class D amplifier is suitable for mobile NMR applications.

  2. Electron spin resonance and nuclear magnetic resonance of sodium macrostructures in strongly irradiated NaCl-K crystals: Manifestation of quasi-one-dimensional behavior of electrons

    NARCIS (Netherlands)

    Cherkasov, FG; Mustafin, RG; L'vov, SG; Denisenko, GA; den Hartog, HW; Vainshtein, D. I.

    1998-01-01

    Data from an investigation of electron spin resonance and nuclear magnetic resonance of NaCl-K (similar to 1 mole%) crystals strongly irradiated with electrons imply the observation of a metal-insulator transition with decreasing temperature and the manifestation of quasi-one-dimensional electron

  3. 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)

  4. 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

  5. Abstracts of Works Presented at 32 All-Polish Seminar on Nuclear Magnetic Resonance and its Application

    International Nuclear Information System (INIS)

    Hennel, J.

    1999-01-01

    The report consist of abstracts of works Presented at 32 All-Polish Seminar on Nuclear Magnetic Resonance and its Application which has been organized at the Henryk Niewodniczanski Institute of Nuclear Physics Cracow, Poland from 1st to 2nd December of 1999. The report covers wide range of NMR problems as measuring methods, its application in biology, medicine and solid state studies

  6. 40. Polish Seminar on Nuclear Magnetic Resonance and Its Applications. Cracow, 3-4 December 2007. Abstracts

    International Nuclear Information System (INIS)

    2007-01-01

    The Report comprises abstracts of 59 communications presented during the 40. Polish Seminar on Nuclear Magnetic Resonance and Its Applications, held on December 3-4, 2007 in Cracow (PL). They cover a variety of research fields, including magnetic resonance imaging in vivo, applications of NMR spectroscopy to medical diagnosis, studies on molecular properties of different materials as well as quantum chemical calculations of NMR parameters

  7. Nuclear magnetic resonance studies of intracellular ions in perfused from heart

    International Nuclear Information System (INIS)

    Burnstein, D.; Fossel, E.T.

    1987-01-01

    Intracellular sodium, potassium, and lithium were observed in a perfused frog heart by nuclear magnetic resonance (NMR) spectroscopy. A perfusate buffer containing the shift reagent, dysprosium tripolyphosphate, was used in combination with mathematical filtering or presaturation of the extracellular resonance to separate the intra- and extracellular sodium NMR signals. Addition of 10 μM ouabain to the perfusate, perfusion with a zero potassium, low-calcium buffer, and replacement of 66% of the perfusate sodium with lithium resulted in changes in the intracellular sodium levels. An increase of 45% in the intracellular sodium was observed when changing the pacing rate from 0 to 60 beats/min (with proportional changes for intermediate pacing rates). The ratio of intracellular potassium to sodium concentration was determined to be 2.3 by NMR, indicating that a substantial amount of the intracellular potassium is undetectable with these NMR method. In addition, intracellular lithium was observed during perfusion with a lithium-containing perfusate

  8. Determination of bound and unbound water in dental alginate irreversible hydrocolloid by nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Fellows, C M; Thomas, G A

    2009-04-01

    Alginate materials are considered unsuitable for precise fixed prosthetic rehabilitation due to their tendency to undergo spontaneous syneresis. Commercial alginate impression materials were investigated using Nuclear Magnetic Resonance (NMR) Spectroscopy to probe the relation between changes in the microscopic water environment and dimensional change to obtain a better understanding of spontaneous syneresis. NMR was used to measure the spin-lattice relaxation times (T(1)) of (1)H nuclei in water in alginate matrices to characterize changes in gel structure over time. These results were related to the dimensional stabilities of the alginate impression materials, their chemical compositions, and the Moisture Sorption Isotherms (MSI) obtained by incubation at fixed relative humidities. The rate of change of T(1) with time was found to be a better predictor of dimensional stability than MSI. The greatest dimensional stability for the alginate powders investigated was associated with a high filler:alginate ratio and a high Ca:Na ratio. Nuclear magnetic resonance spectroscopy may used to measure changes in alginate impression materials under conditions where no dimensional change can be observed directly. Changes occurred rapidly even at 100% humidity, suggesting the dimensional stability of alginate impression materials is partially independent of the rate of dehydration. The results may open a way to formulate alginate impression materials more suitable for precise fabrication of dental prostheses.

  9. Comparative Definitions for Moderate-Severe Ischemia in Stress Nuclear, Echocardiography, and Magnetic Resonance Imaging

    Science.gov (United States)

    Shaw, Leslee J.; Berman, Daniel S.; Picard, Michael H.; Friedrich, Matthias G.; Kwong, Raymond Y.; Stone, Gregg W.; Senior, Roxy; Min, James K.; Hachamovitch, Rory; Scherrer-Crosbie, Marielle; Mieres, Jennifer H.; Marwick, Thomas H.; Phillips, Lawrence M.; Chaudhry, Farooq A.; Pellikka, Patricia A.; Slomka, Piotr; Arai, Andrew E.; Iskandrian, Ami E.; Bateman, Timothy M.; Heller, Gary V.; Miller, Todd D.; Nagel, Eike; Goyal, Abhinav; Borges-Neto, Salvador; Boden, William E.; Reynolds, Harmony R.; Hochman, Judith S.; Maron, David J.; Douglas, Pamela S.

    2014-01-01

    The lack of standardized reporting of the magnitude of ischemia on noninvasive imaging contributes to variability in translating the severity of ischemia across stress imaging modalities. We identified the risk of coronary artery disease (CAD) death or myocardial infarction (MI) associated with ≥10% ischemic myocardium on stress nuclear imaging as the risk threshold for stress echocardiography and cardiac magnetic resonance. A narrative review revealed that ≥10% ischemic myocardium on stress nuclear imaging was associated with a median rate of CAD death or MI of 4.9%/year (interquartile range: 3.75% to 5.3%). For stress echocardiography, ≥3 newly dysfunctional segments portend a median rate of CAD death or MI of 4.5%/year (interquartile range: 3.8% to 5.9%). Although imprecisely delineated, moderate-severe ischemia on cardiac magnetic resonance may be indicated by ≥4 of 32 stress perfusion defects or ≥3 dobutamine-induced dysfunctional segments. Risk-based thresholds can define equivalent amounts of ischemia across the stress imaging modalities, which will help to translate a common understanding of patient risk on which to guide subsequent management decisions. PMID:24925328

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

    International Nuclear Information System (INIS)

    Diaz Gomez, Maritza F.

    2005-01-01

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

  11. Design of a triple resonance magic angle sample spinning probe for high field solid state nuclear magnetic resonance

    Science.gov (United States)

    Martin, Rachel W.; Paulson, Eric K.; Zilm, Kurt W.

    2003-06-01

    Standard design and construction practices used in building nuclear magnetic resonance (NMR) probes for the study of solid state samples become difficult if not entirely impractical to implement as the 1H resonance frequency approaches the self resonance frequency of commercial capacitors. We describe an approach that utilizes short variable transmission line segments as tunable reactances. Such an approach effectively controls stray reactances and provides a higher Q alternative to ceramic chip capacitors. The particular probe described is built to accommodate a 2.5 mm magic angle spinning rotor system, and is triply tuned to 13C, 15N, and 1H frequencies for use at 18.8 T (200, 80, and 800 MHz, respectively). Isolation of the three radio frequency (rf) channels is achieved using both a rejection trap and a transmission line notch filter. The compact geometry of this design allows three channels with high power handling capability to fit in a medium bore (63 mm) magnet. Extended time variable temperature operation is integral to the mechanical design, enabling the temperature control necessary for investigation of biological macromolecules. Accurate measurement of the air temperature near the sample rotor is achieved using a fiber optic thermometer, which does not interfere with the rf electronics. We also demonstrate that acceptable line shapes are only readily achieved using zero magnetic susceptibility wire in construction of the sample coil. Computer simulation of the circuit aided in the physical design of the probe. Representative data illustrating the efficiency, rf homogeneity, and signal to noise factor of the probe are presented.

  12. 13C nuclear magnetic resonance study of the complexation of calcium by taurine

    International Nuclear Information System (INIS)

    Irving, C.S.; Hammer, B.E.; Danyluk, S.S.; Klein, P.D.

    1980-01-01

    13 C Nuclear magnetic resonance chemical shifts, 1 J/sub c-c/ scalar coupling constants, spin-lattice relaxation times, and nuclear Overhauser effects were determined for taurine-[1, 2 13 C] and a taurine-[1 13 C] and taurine-[2 13 C] mixture in the presence and absence of calcium. Comparison of taurine titration shifts to values for related compounds reveals some unusual electronic properties of the taurine molecule. Stability constants of 1:1 calcium complexes with taurine zwitterions and anions, as well as their 13 C chemical shifts, were obtained by least squares analysis of titration curves measured in the presence of calcium. The stability constants of calcium-taurine complexes were significantly lower than previous values and led to estimates that only approximately one percent of intracellular calcium of mammalian myocardial cells would exist in a taurine complex

  13. Substitution effect in nuclear magnetic resonance of C-13: α methoxicyclohexanones

    International Nuclear Information System (INIS)

    Lopez Holland, M.A.G.

    1984-01-01

    Eletronic and steric interactions between the carbonyl and methoxyl groups in α-methoxicyclohexanones by H-1 and C-13 nuclear magnetic resonance spectroscopy (n.m.r) is studied. Interpretation of H-1 n.m.r measurements based on the carbonyl group anisotropy is made. The asigment of spectral lines to specific nuclear by Lanthanide Shift Reagent Experiments is confirmed. Interpretation of C-13 n.m.r. spectra with respect to molecular effects and emphirical relationships associated with the substituent was analysed. The C-13 chemical shift asignment by comparison with results of partially (SFORD) and fully decompled spectra and also by relating the measured chemical shift with values cited in the literature for similar compounds are made. A qualitative study using I.R. spectroscopy in attempt to evaluate the predominance of one the conformers of the studied compounds in solutions of n-hexan and chloroform is made. (M.J.C.) [pt

  14. How to analyze a nuclear magnetic resonance image. Application to the pelvis

    International Nuclear Information System (INIS)

    Parienty, R.; Lavayssiere, R.

    1983-01-01

    Nuclear magnetic resonance (NMR) is based on the behaviour of some atomic nuclei when they are placed in a magnetic field and subjected to radiofrequency waves of a specific length. The resonance signals they emit under such conditions are collected as localized digital data which are used to construct an image. The signals vary according to multiple tissue characteristics, notably proton density, relaxation times T1 and T2 and, where applicable, blood flow direction and velocity. The relative influences exerted by these tissue factors on resonance signals can be evaluated by altering the technical parameters of the examination, that is practically the radiofrequency wave sequence. Special formulae make it possible to predict signal variations and to increase, decrease or even reverse contrast, thus obtaining as many morphological or functional images of the different media in the body. NMR semiology therefore is copious, complex and variable, but a diagrammatic description of the interplay between parameters provides a key to elementary analysis. Images of pelvic structures taken as examples illustrate the necessity to select the exploratory procedure according to the purpose of the exploration or to manipulate sequences with greater safety [fr

  15. How to analyze a nuclear magnetic resonance image. Application to the pelvis

    Energy Technology Data Exchange (ETDEWEB)

    Parienty, R.; Lavayssiere, R.

    1983-01-01

    Nuclear magnetic resonance (NMR) is based on the behaviour of some atomic nuclei when they are placed in a magnetic field and subjected to radiofrequency waves of a specific length. The resonance signals they emit under such conditions are collected as localized digital data which are used to construct an image. The signals vary according to multiple tissue characteristics, notably proton density, relaxation times T1 and T2 and, where applicable, blood flow direction and velocity. The relative influences exerted by these tissue factors on resonance signals can be evaluated by altering the technical parameters of the examination, that is practically the radiofrequency wave sequence. Special formulae make it possible to predict signal variations and to increase, decrease or even reverse contrast, thus obtaining as many morphological or functional images of the different media in the body. NMR semiology therefore is copious, complex and variable, but a diagrammatic description of the interplay between parameters provides a key to elementary analysis. Images of pelvic structures taken as examples illustrate the necessity to select the exploratory procedure according to the purpose of the exploration or to manipulate sequences with greater safety.

  16. Small-scale instrumentation for nuclear magnetic resonance of porous media

    International Nuclear Information System (INIS)

    Bluemich, Bernhard; Casanova, Federico; Dabrowski, Martin; Danieli, Ernesto; Haber, Agnes; Van Landeghem, Maxime; Haber-Pohlmeier, Sabina; Olaru, Alexandra; Perlo, Juan; Sucre, Oscar; Evertz, Loribeth

    2011-01-01

    The investigation of fluids confined to porous media is the oldest topic of investigation with small-scale nuclear magnetic resonance (NMR) instruments, as such instruments are mobile and can be moved to the site of the object, such as the borehole of an oil well. While the analysis was originally restricted by the inferior homogeneity of the employed magnets to relaxation measurements, today, portable magnets are available for all types of NMR measurements concerning relaxometry, imaging and spectroscopy in two types of geometries. These geometries refer to closed magnets that surround the sample and open magnets, which are brought close to the object for measurement. The current state of the art of portable, small-scale NMR instruments is reviewed and recent applications of such instruments are featured. These include the porosity analysis and description of diesel particulate filters, the determination of the moisture content in walls from gray concrete, new approaches to analyze the pore space and moisture migration in soil, and the constitutional analysis of the mortar base of ancient wall paintings.

  17. Healt risks involved in clinical applications of Nuclear Magnetic Resonance Tomography

    International Nuclear Information System (INIS)

    De Crescenzo, S.; Tosi, G.; Scialfa, F.

    1987-01-01

    The use of Nuclear Magnetic Resonance Imaging for diagnostic purpose requires a careful analysis of potential risks for workers, patients and public. Aim of this work is a review of the most important biological effects produced by static magnetic fields, radiofrequency fields and field gradients. It's common opinion in fact that the use of magnetic and radiofrequency fields instead of ionizing radiations fields is surity warranty for patients and workers. Biological experiments in small animals and microorganisms show that also in this case some risks may be expected, due to the trend to employ as much high as possible magnetic fields (and therefore radiofrequency fields). The available data show that the normally used magnetic and radiofrequency fields are below the threshold for somatic effects but denote the necessity of a careful risks/benefit analysis for some patients group (pacemakers and small surgical metallic implants carriers) and the need of extended and deep studies to specify a possible synergy of different physical agents and incidental oncogenic and terathogenic consequence on the patient

  18. Small-scale instrumentation for nuclear magnetic resonance of porous media

    Energy Technology Data Exchange (ETDEWEB)

    Bluemich, Bernhard; Casanova, Federico; Dabrowski, Martin; Danieli, Ernesto; Haber, Agnes; Van Landeghem, Maxime; Haber-Pohlmeier, Sabina; Olaru, Alexandra; Perlo, Juan; Sucre, Oscar [Institute of Technical and Macromolecular Chemistry, RWTH Aachen University, D-542056 Aachen (Germany); Evertz, Loribeth, E-mail: bluemich@mc.rwth-aachen.de [Mechanical and Industrial Engineering, Montana State University, PO Box 173800, Bozeman, MT 59717-3800 (United States)

    2011-01-15

    The investigation of fluids confined to porous media is the oldest topic of investigation with small-scale nuclear magnetic resonance (NMR) instruments, as such instruments are mobile and can be moved to the site of the object, such as the borehole of an oil well. While the analysis was originally restricted by the inferior homogeneity of the employed magnets to relaxation measurements, today, portable magnets are available for all types of NMR measurements concerning relaxometry, imaging and spectroscopy in two types of geometries. These geometries refer to closed magnets that surround the sample and open magnets, which are brought close to the object for measurement. The current state of the art of portable, small-scale NMR instruments is reviewed and recent applications of such instruments are featured. These include the porosity analysis and description of diesel particulate filters, the determination of the moisture content in walls from gray concrete, new approaches to analyze the pore space and moisture migration in soil, and the constitutional analysis of the mortar base of ancient wall paintings.

  19. A Unilateral Nuclear Magnetic Resonance Sensor for Nondestructive Wood Moisture Measurements

    Directory of Open Access Journals (Sweden)

    YU Deng-jie

    2017-12-01

    Full Text Available An unilateral nuclear magnetic resonance (UMR sensor was designed to measure wood moisture nondestructively. The sensor consisted of a unilateral magnet, an anti-eddy current module, a radiofrequency (RF coil and an impedance matching and tuning circuit. The sensor produced a static magnetic field of 71.1 mT (resonant frequency:3.027 MHz in a 50 mm×50 mm plane locating 75 mm above the sensor's surface. Preliminary nondestructive measurement of wood moisture was carried out with the sensor. The moisture distribution in the radical direction of a cylindrical wood sample was scanned. Variations in transverse relaxation time (T2 from the bark to core were obtained. Evaporation of moisture during wood drying was also measured with the UMR sensor. Experimental results showed that:the peak of long T2 component in the T2 spectrum moved to left and the peak integral area decreased gradually during drying. The integral area was proportional to the moisture content of the sample. The work presents a portable UMR device for wood research which may potentially be used for nondestructive moisture measurement on living trees in situ.

  20. 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.

  1. Acoustic Resonance in School Hallways

    Science.gov (United States)

    Bucki, Elliot; Nagle, Matthew; Smith, Pearson; Taylor, Ken

    2010-03-01

    This paper takes the theory of acoustic standing waves for air columns and applies it to school hallways. By utilizing an audio generator and power amplifier/speaker the authors set up an experiment in a school hallway and studied the resonant patterns created for a range of driving frequencies. Data describing the various mode structures are presented.

  2. Advances in magnetic resonance 6

    CERN Document Server

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 6 focuses on the theoretical and practical aspects of applying magnetic resonance methods to various problems in physical chemistry, emphasizing the different aspects of the exegesis of these problems. This book discusses the gas phase magnetic resonance of electronically excited molecules; techniques for observing excited electronic states; NMR studies in liquids at high pressure; and effect of pressure on self-diffusion in liquids. The nuclear magnetic resonance investigations of organic free radicals; measurement of proton coupling constants by NMR; an

  3. Study on VCSEL laser heating chip in nuclear magnetic resonance gyroscope

    Science.gov (United States)

    Liang, Xiaoyang; Zhou, Binquan; Wu, Wenfeng; Jia, Yuchen; Wang, Jing

    2017-10-01

    In recent years, atomic gyroscope has become an important direction of inertial navigation. Nuclear magnetic resonance gyroscope has a stronger advantage in the miniaturization of the size. In atomic gyroscope, the lasers are indispensable devices which has an important effect on the improvement of the gyroscope performance. The frequency stability of the VCSEL lasers requires high precision control of temperature. However, the heating current of the laser will definitely bring in the magnetic field, and the sensitive device, alkali vapor cell, is very sensitive to the magnetic field, so that the metal pattern of the heating chip should be designed ingeniously to eliminate the magnetic field introduced by the heating current. In this paper, a heating chip was fabricated by MEMS process, i.e. depositing platinum on semiconductor substrates. Platinum has long been considered as a good resistance material used for measuring temperature The VCSEL laser chip is fixed in the center of the heating chip. The thermometer resistor measures the temperature of the heating chip, which can be considered as the same temperature of the VCSEL laser chip, by turning the temperature signal into voltage signal. The FPGA chip is used as a micro controller, and combined with PID control algorithm constitute a closed loop control circuit. The voltage applied to the heating resistor wire is modified to achieve the temperature control of the VCSEL laser. In this way, the laser frequency can be controlled stably and easily. Ultimately, the temperature stability can be achieved better than 100mK.

  4. Remote detection of oil spilled under ice and snow using nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Nedwed, T.; Srnka, L.; Thomann, H.

    2008-01-01

    The technical challenge of detecting oil that has been accidentally spilled under ice and snow was discussed with particular reference to the tools used to characterize the molecular composition of liquids and solids. One such tool is nuclear magnetic resonance (NMR) which works by releasing electromagnetic energy. The NMR signals from oil and water can be differentiated based on the inherent differences in the NMR signal responses from different fluid types. The method can also use the Earth's magnetic field as the static magnetic field and thereby eliminate the complexity and cost of generating an independent magnetic field for remotely detecting fluids below a surface. This study examined the feasibility of altering existing surface-based instruments and placing them in a helicopter for aerial monitoring. The goal of this research was to develop a tool for remote detection of oil under ice in a marine environment, or for detection of oil under snow on land using an inexpensive tool that can quickly inspect large areas. The proposed tool and technique produces a direct hydrocarbon signal that may not have interference from ice and snow. 9 refs., 6 figs

  5. Computed Tomography and Nuclear Magnetic Resonance to study the internal structure and measure weathering

    Science.gov (United States)

    Zornoza-Indart, A.; Lopez-Arce, P.; Alvarez de Buergo, M.; Fort, R.

    2012-04-01

    Outdoor stone heritage is prone to decay due to its direct exposure to weathering agents such us thermal shock caused by isolation processes, salt crystallization phenomena, atmospheric pollutants effects on stone surfaces, freezing and thawing cycles or biodeterioration o decay provoked by biogenic activity. These damages use to affect the surface of the objects or elements causing de-cohesions (flaking, spallings, grain disintegration), material loss or color changes, but also use to affect the internal structure of the objects, although they are not visible, causing internal pressures, fissures and fractures, mineral transformations or inner biodeterioration compromising objects conservation. For this reason, the study of the internal structure of the objects is necessary to establish its weathering and conservation state, to determine its restoration needs and achieve its conservation. Moreover, in cultural heritage where the originality of the objects and their historical or artistic values are so important the use of non-destructive techniques result necessary for their study without causing any damage by sampling. In this work X ray Computed Tomography (CT) and Nuclear Magnetic Resonance (NMR) are used to analyze rock samples (dolostones used in historical buildings from Central Spain and Madrid both in the city and in the province) subjected to different artificial accelerated ageing tests (thermal shock, salt crystallization, freezing and thawing cycles and marine aerosol) to simulate the most common outdoor heritage deterioration scenarios. The changes in the internal structure and pore system modifications are studied with these non-destructive techniques. Nuclear Magnetic Resonance (both imaging and relaxometry) experiments were performed in stone specimens to observe and to quantify the location and distribution of water inside the objects, been able to analyze pore size and location. X ray Computed Tomography was used for visualizing and locating

  6. SQUIDs vs. Faraday coils for ultlra-low field nuclear magnetic resonance: experimental and simulation comparison

    Energy Technology Data Exchange (ETDEWEB)

    Matlashov, Andrei N [Los Alamos National Laboratory; Espy, Michelle A [Los Alamos National Laboratory; Kraus, Robert H [Los Alamos National Laboratory; Sayukov, Igor M [Los Alamos National Laboratory; Schultz, Larry J [Los Alamos National Laboratory; Urbaitis, Algis V [Los Alamos National Laboratory; Volegov, Petr L [Los Alamos National Laboratory; Wurden, Caroline J [Los Alamos National Laboratory

    2010-01-01

    Nuclear magnetic resonance (NMR) methods are widely used in medicine, chemistry and industry. One application area is magnetic resonance imaging or MRI. Recently it has become possible to perform NMR and MRI in ultra-low field (ULF) regime that requires measurement field strengths only of the order of 1 Gauss. These techniques exploit the advantages offered by superconducting quantum interference devices or SQUIDs. Our group at LANL has built SQUID based MRI systems for brain imaging and for liquid explosives detection at airports security checkpoints. The requirement for liquid helium cooling limits potential applications of ULF MRI for liquid identification and security purposes. Our experimental comparative investigation shows that room temperature inductive magnetometers provide enough sensitivity in the 3-10 kHz range and can be used for fast liquid explosives detection based on ULF NMR/MRI technique. We describe an experimental and computer simulation comparison of the world's first multichannel SQUID based and Faraday coils based instruments that are capable of performing ULF MRI for liquids identification.

  7. The 31P nuclear magnetic resonance (NMR) study of the preserved kidneys, 4

    International Nuclear Information System (INIS)

    Kunikata, Seiji

    1987-01-01

    31 P nuclear magnetic resonance (NMR) provides much information about the energy metabolism of living systems. Although the NMR is nondestructive, most studies have been carried out on excised, perfused organs and tissues. However, it is necessary to study the metabolism in vivo of living systems. NMR spectra from a selected, localized place are obtained using topical magnetic resonance (TMR). The energy metabolism of a selected organ in a living animal can be measured with 31 P TMR. I report here on the energy metabolism of kidneys in live, anesthetized rabbits measured by 31 P TMR. Some phosphorylated metabolites could be detected. The ATP signal of a ischemic kidney disappeared within 30 minitutes, while the Pi signal increased. The recovery of the parameter of ATP intensity/Pi intensity on ischemic kidneys was studied. Kidneys subjected to ischemia for a shorter time than one hour mostly recovered. However, kidneys subjected to ischemia for a longer time than two hours recovered poorly. This result agreed with the ability to regenerate ATP in different ischemic kidneys measured by high pressure liquid chromatography. It seemed that the parameter of ATP intensity/Pi intensity was suitable for the assessment of the severity of ischemic kidney damage. I think that 31 P NMR can be a useful clinical tool. (author)

  8. Signal interferences from turbulent spin dynamics in solution nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Huang, Susie Y.; Lin, Yung-Ya; Lisitza, Natalia; Warren, Warren S.

    2002-06-01

    Artifacts arising from aperiodic turbulent spin dynamics in gradient-based nuclear magnetic resonance (NMR) applications are comprehensively surveyed and numerically simulated by a nonlinear Bloch equation. The unexpected dynamics, triggered by the joint action of radiation damping and the distant dipolar field, markedly deteriorate the performance of certain pulse sequences incorporating weak pulsed-field gradients and long evolution times. The effects are demonstrated in three general classes of gradient NMR applications: solvent signal suppression, diffusion measurements, and coherence pathway selection. Gradient-modulated solvent transverse magnetization can be partially rephased in a series of self-refocusing gradient echoes that blank out solute resonances in the CHESS (chemical-shift-selective spectroscopy) and WATERGATE (gradient-tailored water suppression) solvent suppression schemes. In addition, the discovered dynamics contribute to erratic echo attenuation in pulsed gradient spin echo (PGSE) and PGSE stimulated echo diffusion measurements and produce coherence leakage in gradient-selected DQFCOSY and HMQC experiments. Specific remedies for minimizing unwanted effects are presented.

  9. Characterization of polymer-type ionic conductors using nuclear magnetic resonance and thermal analysis. Humidity sensor

    International Nuclear Information System (INIS)

    Cavalcante, Maria Goretti.

    1992-04-01

    We report a study using Nuclear Magnetic Resonance (NMR), Thermogravimetry Analysis, Differential Scanning Calorimetry and Infrared Spectroscopy in polymeric complexes formed poly(ethylene oxide), (PEO), and lithium salts. These complexes have have shown a large potential for technological applications in batteries, sensors, etc. We developed and characterized humidity sensors and discussed how the humidity affects the conformation of the complexes, the mobility of ionic species, and the polymeric chains. The results indicate that the hydration affects the conformation of polymeric complexes by plasticizing the water, which induces a volumetric expansion in the PEO chain. The processes was completely reversible for the level of hydration studied. NMR was used to distinguish the movement of polymeric chains from the movement of the ionic species. From the analysis of the second moment of resonance lines from the study of the nuclear relaxation we were able to estimate the average distance between the ionic species and the proton in the complexes chains. The behaviour of spin -lattice relaxation of hydrogen and fluorine in the P(EO) - Li B F, as a function of temperature and frequency reflects the nature of the disorder and the complexity of the ionic conduction process in these materials. (author). 91 refs., 69 figs., 2 tabs

  10. Numerical simulation and experimental study on Resonant Acoustic Chambers-For novel, high-efficiency nuclear particle detectors

    International Nuclear Information System (INIS)

    Wang Jing; Archambault, Brian; Xu, Yiban; Taleyarkhan, Rusi P.

    2010-01-01

    Acoustic-structural-electromagnetic coupled models have been successfully set up for Resonant Acoustic Chambers (RACs). RACs have important applications in several areas such as radiation detection, sonoluminescence and sonofusion. The goal of this undertaking was able to simulate transient acoustically driven metastable states and structural responses so that the designs of RACs can be optimized for advanced applications. The simulation predictions have been benchmarked with experimental data in two designs of RACs, Open Chamber System (OCS) and Closed Chamber System (CCS). A framework was developed for benchmarking and validating the predicted resonant frequency and oscillatory pressure mapping profiles with and without scattering centers. Experiments were conducted with and without external neutron-induced cavitation bubble clusters. Comparison of measurements versus experimental data demonstrated the applicability of the modeling-cum-simulation framework. Studies have provided insights into the significant and complex influences of fluid-structure-electromagnetic coupling and on the influence of scattering center inclusions on the system's acoustic responses. The framework appears reasonable for design of advanced, high-powered RACs; however, significant technical challenges remain with respect to capturing the overall system performance upon evolution and transport of transient bubble clusters.

  11. The cosmic axion spin precession experiment (CASPEr): a dark-matter search with nuclear magnetic resonance

    Science.gov (United States)

    Garcon, Antoine; Aybas, Deniz; Blanchard, John W.; Centers, Gary; Figueroa, Nataniel L.; Graham, Peter W.; Kimball, Derek F. Jackson; Rajendran, Surjeet; Gil Sendra, Marina; Sushkov, Alexander O.; Trahms, Lutz; Wang, Tao; Wickenbrock, Arne; Wu, Teng; Budker, Dmitry

    2018-01-01

    The cosmic axion spin precession experiment (CASPEr) is a nuclear magnetic resonance experiment (NMR) seeking to detect axion and axion-like particles which could make up the dark matter present in the Universe. We review the predicted couplings of axions and axion-like particles with baryonic matter that enable their detection via NMR. We then describe two measurement schemes being implemented in CASPEr. The first method, presented in the original CASPEr proposal, consists of a resonant search via continuous-wave NMR spectroscopy. This method offers the highest sensitivity for frequencies ranging from a few Hz to hundreds of MHz, corresponding to masses {m}{{a}}∼ {10}-14–{10}-6 eV. Sub-Hz frequencies are typically difficult to probe with NMR due to the diminishing sensitivity of magnetometers in this region. To circumvent this limitation, we suggest new detection and data processing modalities. We describe a non-resonant frequency-modulation detection scheme, enabling searches from mHz to Hz frequencies ({m}{{a}}∼ {10}-17–{10}-14 eV), extending the detection bandwidth by three decades.

  12. Investigations into the adsorption behaviour of zeolites using nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Hennig, H.J.

    1973-01-01

    The interactions between adsorbed molecules and the walls of the cavities in faujasite have been investigated; even the sodium form of the A type zeolite was included in the investigation. The nuclear magnetic resonance measurements were performed with a varian DP-60 wide line resonance spectrometer. The measuring frequency was generally 16 MHg the modulation frequency 20 Hz. The resonance effect was recorded in the form of the derived absorption signal. It was found that the water molecules form hydrogen bonds to the oxygen ions of the alumozilicate structure, the hydrogen sulphide on the other hand splits off protons which under formation of OH groups bind in the oxygen ions of the alumosilicate structure. The results obtained with sulphur dioxide imply that these molecules bind onto the oxygen ions of the alumosilicate structure via sulphur and thus occupy their free electron pairs. The translation mobility of the absorbed molecules present at room temperature is very much reduced when cooling down to certain temperatures; this solidification temperature of the adsorbate lies below that of the pure liquids. Probably the absorbed molecules are deposited in one or several layers onto the walls of the cavity. Prefered sorption sites for the faujasites are the sodium ions in front of the six-membered rings on the walls fo the large cavities, with NaA, on the other hand, the sodium ions are in the eight-membered rings. (ORU) [de

  13. Acoustic Fano resonators

    KAUST Repository

    Amin, Muhammad

    2014-07-01

    The resonances with asymmetric Fano line-shapes were originally discovered in the context of quantum mechanics (U. Fano, Phys. Rev., 124, 1866-1878, 1961). Quantum Fano resonances were generated from destructive interference of a discrete state with a continuum one. During the last decade this concept has been applied in plasmonics where the interference between a narrowband polariton and a broader one has been used to generate electromagnetically induced transparency (EIT) (M. Rahmani, et al., Laser Photon. Rev., 7, 329-349, 2013).

  14. Magnetic resonance imaging (MRI

    Directory of Open Access Journals (Sweden)

    Takavar A

    1993-04-01

    Full Text Available Basic physical principles of nuclear magnetic resonance imaging (N.M.R.I, a nonionizing medical imaging technique, are described. Principles of NMRI with other conventional imaging methods, ie, isotope scanning, ultrasonography and radiography have been compared. T1 and T2 and spin density (S.D. factors and different image construction techniques based on their different combinations is discussed and at the end physical properties of some N.M.R images is mentioned.

  15. Magnetic resonance imaging (MRI)

    OpenAIRE

    Takavar A

    1993-01-01

    Basic physical principles of nuclear magnetic resonance imaging (N.M.R.I), a nonionizing medical imaging technique, are described. Principles of NMRI with other conventional imaging methods, ie, isotope scanning, ultrasonography and radiography have been compared. T1 and T2 and spin density (S.D.) factors and different image construction techniques based on their different combinations is discussed and at the end physical properties of some N.M.R images is mentioned.

  16. Phosphorus-31 nuclear magnetic resonance spectroscopic study of the canine pancreas: applications to acute alcoholic pancreatitis

    Energy Technology Data Exchange (ETDEWEB)

    Janes, N.; Clemens, J.A.; Glickson, J.D.; Cameron, J.L.

    1988-01-01

    The first nuclear magnetic resonance spectroscopic study of the canine pancreas is described. Both in-vivo, ex-vivo protocols and NMR observables are discussed. The stability of the ex-vivo preparation based on the NMR observables is established for at least four hours. The spectra obtained from the in-vivo and ex-vivo preparations exhibited similar metabolite ratios, further validating the model. Metabolite levels were unchanged by a 50% increase in perfusion rate. Only trace amounts of phosphocreatine were observed either in the intact gland or in extracts. Acute alcoholic pancreatitis was mimicked by free fatty acid infusion. Injury resulted in hyperamylasemia, edema (weight gain), increased hematocrit and perfusion pressure, and depressed levels of high energy phosphates.

  17. 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.

  18. Fluorine nuclear magnetic resonance-based assay in living mammalian cells.

    Science.gov (United States)

    Veronesi, Marina; Giacomina, Francesca; Romeo, Elisa; Castellani, Beatrice; Ottonello, Giuliana; Lambruschini, Chiara; Garau, Gianpiero; Scarpelli, Rita; Bandiera, Tiziano; Piomelli, Daniele; Dalvit, Claudio

    2016-02-15

    Nuclear magnetic resonance (NMR)-based screening has been recognized as a powerful approach for the identification and characterization of molecules interacting with pharmaceutical targets. Indeed, several NMR methods have been developed and successfully applied to many drug discovery projects. Whereas most of these approaches have targeted isolated biomolecular receptors, very few cases are reported with the screening performed in intact cells and cell extracts. Here we report the first successful application of the fluorine NMR-based assay n-FABS (n-fluorine atoms for biochemical screening) in living mammalian cells expressing the membrane protein fatty acid amide hydrolase (FAAH). This method allows the identification of both weak and potent inhibitors and the measurement of their potency in a physiological environment. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. A low noise photoelectric signal acquisition system applying in nuclear magnetic resonance gyroscope

    Science.gov (United States)

    Lu, Qilin; Zhang, Xian; Zhao, Xinghua; Yang, Dan; Zhou, Binquan; Hu, Zhaohui

    2017-10-01

    The nuclear magnetic resonance gyroscope serves as a new generation of strong support for the development of high-tech weapons, it solves the core problem that limits the development of the long-playing seamless navigation and positioning. In the NMR gyroscope, the output signal with atomic precession frequency is detected by the probe light, the final crucial photoelectric signal of the probe light directly decides the quality of the gyro signal. But the output signal has high sensitivity, resolution and measurement accuracy for the photoelectric detection system. In order to detect the measured signal better, this paper proposed a weak photoelectric signal rapid acquisition system, which has high SNR and the frequency of responded signal is up to 100 KHz to let the weak output signal with high frequency of the NMR gyroscope can be detected better.

  20. 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.

  1. 31P nuclear magnetic resonance surface coil study of ischemic preconditioned isolated perfused rat heart

    International Nuclear Information System (INIS)

    Yan Yongbin; Luo Xuechun; Zhang Riqing; Wang Xiaoyin; Zuo Lin; Liu Wei

    2000-01-01

    ischemic preconditioning (IPC) will protect the heart from the damage caused by a subsequent long ischemia period. 31 P spectra of isolated perfused rat heart measured by the nuclear magnetic resonance (NMR) surface coil technique can be used to continually, dynamically and noninvasively obtain metabolism information. This paper explores the IPC mechanisms by NMR. This study shows that IPC has no effect on enhancing the ATP and PCr levels during reperfusion but makes significantly slows and smooths the changes of intracellular pH and ATP during ischemia periods. The ATP and PCr recovery rate of the IPC group after ischemia is significantly higher than that of the control group. In conclusion, the above results support that IPC can protect the rat heart by reducing damage during the ischemia period

  2. 2H nuclear magnetic resonance spectroscopy of deuterium adsorption on single-walled carbon nanotubes

    Science.gov (United States)

    Shen, Kai; Pietraß, Tanja

    2004-03-01

    2H nuclear magnetic resonance (NMR) spectroscopy was employed to study the interaction between deuterated hydrogen gas and single walled carbon nanotubes before and after purification. Transmission electron micrographs revealed strong bundling of the tubes. After purification, very little amorphous carbon and no graphitic particles were present, implying that the interactions observed are truly due to the nanotubes. In the parent material, the NMR signal is dominated by interaction of hydrogen with residual metal catalyst particles. For purified material, hydrogen in the gas phase is discernible from adsorbed hydrogen. The two phases do not exchange with each other on a ms time scale. The hydrogen molecules move among different adsorption sites, presumably outer tube surfaces and interstitial channels. This process is diffusion limited in the pressure range investigated.

  3. 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.

  4. Evaluation of Possible Nuclear Magnetic Resonance Diagnostic Techniques for Tokamak Experiments

    International Nuclear Information System (INIS)

    S.J. Zweben; T.W. Kornack; D. Majeski; G. Schilling; C.H. Skinner; R. Wilson

    2002-01-01

    Potential applications of nuclear magnetic resonance (NMR) diagnostic techniques to tokamak experiments are evaluated. NMR frequencies for hydrogen isotopes and low-Z nuclei in such experiments are in the frequency range approximately equal to 20-200 MHz, so existing RF [radio-frequency] antennas could be used to rotate the spin polarization and to make the NMR measurements. Our tentative conclusion is that such measurements are possible if highly spin polarized H or (superscript)3He gas sources (which exist) are used to fuel these plasmas. In addition, NMR measurements of the surface layers of the first wall (without plasma) may also be possible, e.g., to evaluate the inventory of tritium inside the vessel

  5. 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...... composition. In this study we relate NMR data to changes in P-wave velocity and electrical resistivity. Core plugs from outcrop Stevns chalk, of 44% porosity, were divided into groups of three and saturated with deionized water, calcite equilibrated water, as well as sodium chloride and magnesium chloride...... solutions of the same ionic strength. Saturation with a solution that contained divalent ions caused a major shift on the distribution of the relaxation time. The changes were probably due to precipitats forming extra internal surface in the sample. Sonic velocities were relatively low in the MgCl2 solution...

  6. {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).

  7. Synthesis and Analysis of Methacryloyl-L-Alanine Methyl Ester using fourier Transform Nuclear Magnetic Resonance

    International Nuclear Information System (INIS)

    Tri Darwinto

    2008-01-01

    Methacryloyl-L-alanine methyl ester was synthesized by reacting methacrylic acid with L-alanine methyl ester hydrochloride in triethylamine at temperature of 90 o C. Hydrogel polymer of poly(methacryloyl-L-alanine methyl ester) was much used for diagnosis and therapy of vascular tumor. The molecular structure methacryloyl-L-alanine methyl ester analyzed by fourier transform nuclear magnetic resonance (FT-NMR) for analyzing of carbon atom ( 13 C) using Distortionless Enhancement by Polarization Transfer (DEPT) measurement mode with coupling as well as without coupling from proton atom ( 1 H). Molecular structure analysis result showed that DEPT FT-NMR measurement mode with coupling as well as without coupling from 1 H was very fast, exact and accurate method for molecular analysis of organic compound especially methacryloyl-L-alanine methyl ester. (author)

  8. Interaction between EDTA and sodium hypochlorite: a nuclear magnetic resonance analysis.

    Science.gov (United States)

    Grande, Nicola Maria; Plotino, Gianluca; Falanga, Alessandro; Pomponi, Massimo; Somma, Francesco

    2006-05-01

    Recent studies detected erosion of the dentinal walls following the use of EDTA as a final flush. Several authors have studied degradation of EDTA and it appears to be caused by an oxidation reaction. The objective of this paper was to verify through nuclear magnetic resonance (NMR) analysis if the oxidizing property of sodium hypochlorite inactivates EDTA. Solutions of sodium hypochlorite and EDTA were analyzed. EDTA tracing and the appearance of new signals indicative of by-products of the reaction, were studied at different time intervals with a NMR analysis. The tracings of NMR analysis confirmed that the reaction between sodium hypochlorite and EDTA lead to a very slow but progressive degradation of this compound. Mindful of the limitations of an in vitro study, the results of this study nevertheless demonstrated that a final flush with sodium hypochlorite cannot limit the chelating effects of EDTA in a clinically realistic time period.

  9. Enabling surface nuclear magnetic resonance at high-noise environments using a pre-polarization pulse

    Science.gov (United States)

    Lin, Tingting; Yang, Yujing; Teng, Fei; Müller-Petke, Mike

    2018-02-01

    The technique of surface nuclear magnetic resonance (SNMR) has been widely used for hydrological investigations in recent years. Unfortunately, the detected SNMR signals are limited to tens of nanovolts and are thus susceptible to environmental noise. While pre-polarization pulses to enhance the detected signal amplitudes are common in laboratory applications, SNMR field testing has only utilized excitation pulses until now. In conducting measurements in China, we demonstrate that adding a pre-polarization field to the SNMR pulse sequence is feasible and allows for the reliable detection of SNMR signals in noisy scenarios that otherwise prohibit signal detection. We introduce a forward modelling for pre-polarization using SNMR and present a three-layer model obtained from inverse modelling that satisfies the observed data from the field experiment. We expect this development to open up new applications for SNMR technology, especially in high-noise level places, such as active mines.

  10. NATO Advanced Research Workshop on 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...

  11. Conformational disorder in folded and intrinsically disordered proteins from nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Salmon, Loic

    2010-01-01

    Biological macromolecules are, by essence, dynamical systems. While the importance of this flexibility is nowadays well established, the accurate characterization of the conformational disorder of these systems remains an important challenge. Nuclear magnetic resonance spectroscopy is a unique tool to probe these motions at atomic level, through the analysis of spin relaxation or residual dipolar couplings. The latter allows all motions occurring at timescales faster than the millisecond to be investigated, including physiologically important timescales. The information presents in those couplings is interpreted here using mainly analytical approaches in order to quantify the amounts of dynamics present in folded protein, to determine the direction of those motions and to obtain structural information within this conformational disorder. These analytical approaches are complemented by numerical methods, that allowed the observation of phenomena from a different point of view or the investigation of other systems such as intrinsically disordered proteins. All of these studies demonstrate an important complementarity between structural order and conformational disorder. (author)

  12. 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...

  13. The design of nuclear magnetic resonance programmable pulsed source based SOPC

    International Nuclear Information System (INIS)

    Zhang Qingshun; Zhang Yakun; Wang Wenli

    2012-01-01

    The design of pulse source in the equipment of pulsed Nuclear Magnetic Resonance is studied based on SOPC. The strong processing power of Nios Ⅱ embedded processor and the design flexibility of FPGA are fully used. The SOPC system is built. The overall design plan for the pulse source is described. The design of programmable multi-pulse generation logic user-defined components in the FPGA is introduced mainly. Part of the implementation program and the task logic simulation waveforms are presented. The pulse source has better application value because a clear, stable and good quality multi-pulse output waveform can be shown on the oscilloscope finally. The system software and hardware are easy to be modified and upgraded, meeting different application of pulsed NMR pulse sequence in variety of requirements. (authors)

  14. 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.

  15. Recrystallization inhibition in ice due to ice binding protein activity detected by nuclear magnetic resonance.

    Science.gov (United States)

    Brown, Jennifer R; Seymour, Joseph D; Brox, Timothy I; Skidmore, Mark L; Wang, Chen; Christner, Brent C; Luo, Bing-Hao; Codd, Sarah L

    2014-09-01

    Liquid water present in polycrystalline ice at the interstices between ice crystals results in a network of liquid-filled veins and nodes within a solid ice matrix, making ice a low porosity porous media. Here we used nuclear magnetic resonance (NMR) relaxation and time dependent self-diffusion measurements developed for porous media applications to monitor three dimensional changes to the vein network in ices with and without a bacterial ice binding protein (IBP). Shorter effective diffusion distances were detected as a function of increased irreversible ice binding activity, indicating inhibition of ice recrystallization and persistent small crystal structure. The modification of ice structure by the IBP demonstrates a potential mechanism for the microorganism to enhance survivability in ice. These results highlight the potential of NMR techniques in evaluation of the impact of IBPs on vein network structure and recrystallization processes; information useful for continued development of ice-interacting proteins for biotechnology applications.

  16. Phosphor investigation in the production of Syrian phosphoric acid using Nuclear Magnetic Resonance

    International Nuclear Information System (INIS)

    Al-Hassanieh, O.; Al-Hameish, M.

    2009-06-01

    Nuclear magnetic resonance spectroscopy (NMR) was applied in this work to the industrial process of extraction of uranium from phosphoric acid and to the process of the purification of the phosphoric acid for food proposes. The structural changes of used extraction materials and the organic content of the final product was studied. 13 C , 1 H and 32 P-spectra of all material during the process were recorded. The spectra of the three used extraction materials Bis(2-ethylhexyl Phosphoric Acid)) DEHPA, TriOctyl Phosphine Oxide (TOPO) (C 8 H 1 7) 3 P=O and TriButyl Phosphate (TBP) (C 4 H 9 O) 3 P=O show a partial degradation during the process. The final product ( Phosphoric acid for Food proposes) doesn't contain any organic solvents or extraction material. (author)

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

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

    International Nuclear Information System (INIS)

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

    1981-01-01

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

  19. H-Nuclear Magnetic Resonance-Based Plasma Metabolic Profiling of Dairy Cows with Fatty Liver

    Directory of Open Access Journals (Sweden)

    Chuang Xu

    2016-02-01

    Full Text Available 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 1H 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.

  20. Monitoring of the insecticide trichlorfon by phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy

    International Nuclear Information System (INIS)

    Talebpour, Zahra; Ghassempour, Alireza; Zendehzaban, Mehdi; Bijanzadeh, Hamid Reza; Mirjalili, Mohammad Hossein

    2006-01-01

    Trichlorfon is an organophosphorus insecticide, which is extensively being used for protection of fruit crops. Trichlorfon is a thermal labile compound, which cannot be easily determined by gas chromatography (GC) and has no suitable group for sensitive detection by high performance liquid chromatography (HPLC). In this study, a 31 P nuclear magnetic resonance ( 31 P NMR) has been described for monitoring of trichlorfon without any separation step. The quantitative works of 31 P NMR spectroscopy has been performed in the presence of an internal standard (hexamethylphosphoramide). Limit of detection (LOD) for this method has been found to be 55 mg L -1 , without any sample preparation, and the linear working range was 150-5500 mg L -1 . Relative standard deviation (R.S.D.%) of the method for three replicates within and between days was obtained ≤9%. The average recovery efficiency was approximately 99-112%. This method was applied for monitoring trichlorfon in a commercial insecticide sample and tomato sample

  1. 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.

  2. 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...

  3. 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

  4. Estimation of water retention parameters from nuclear magnetic resonance relaxation time distributions.

    Science.gov (United States)

    Costabel, Stephan; Yaramanci, Ugur

    2013-04-01

    [1] For characterizing water flow in the vadose zone, the water retention curve (WRC) of the soil must be known. Because conventional WRC measurements demand much time and effort in the laboratory, alternative methods with shortened measurement duration are desired. The WRC can be estimated, for instance, from the cumulative pore size distribution (PSD) of the investigated material. Geophysical applications of nuclear magnetic resonance (NMR) relaxometry have successfully been applied to recover PSDs of sandstones and limestones. It is therefore expected that the multiexponential analysis of the NMR signal from water-saturated loose sediments leads to a reliable estimation of the WRC. We propose an approach to estimate the WRC using the cumulative NMR relaxation time distribution and approximate it with the well-known van-Genuchten (VG) model. Thereby, the VG parameter n , which controls the curvature of the WRC, is of particular interest, because it is the essential parameter to predict the relative hydraulic conductivity. The NMR curves are calibrated with only two conventional WRC measurements, first, to determine the residual water content and, second, to define a fixed point that relates the relaxation time to a corresponding capillary pressure. We test our approach with natural and artificial soil samples and compare the NMR-based results to WRC measurements using a pressure plate apparatus and to WRC predictions from the software ROSETTA. We found that for sandy soils n can reliably be estimated with NMR, whereas for samples with clay and silt contents higher than 10% the estimation fails. This is the case when the hydraulic properties of the soil are mainly controlled by the pore constrictions. For such samples, the sensitivity of the NMR method for the pore bodies hampers a plausible WRC estimation. Citation: Costabel, S., and U. Yaramanci (2013), Estimation of water retention parameters from nuclear magnetic resonance relaxation time distributions, Water

  5. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yuqing; Cai, Shuhui; Yang, Yu; Sun, Huijun; Lin, Yanqin, E-mail: linyq@xmu.edu.cn, E-mail: chenz@xmu.edu.cn; Chen, Zhong, E-mail: linyq@xmu.edu.cn, E-mail: chenz@xmu.edu.cn [Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, State Key Laboratory for Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005 (China); Lin, Yung-Ya [Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095 (United States)

    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.

  7. 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

  8. Proton nuclear magnetic resonance and spectrophotometric studies of nickel(II)-iron(II) hybrid hemoglobins

    International Nuclear Information System (INIS)

    Shibayama, N.; Inubushi, T.; Morimoto, H.; Yonetani, T.

    1987-01-01

    Ni(II)-Fe(II) hybrid hemoglobins, α(Fe) 2 β(Ni) 2 and α(Ni) 2 β(Fe) 2 , have been characterized by proton nuclear magnetic resonance with Ni(II) protoporphyrin IX (Ni-PP) incorporated in apoprotein, which serves as a permanent deoxyheme. α(Fe) 2 β(Ni) 2 , α(Ni) 2 β(Fe) 2 , and NiHb commonly show exchangeable proton resonances at 11 and 14 ppm, due to hydrogen-bonded protons in a deoxy-like structure. Upon binding of carbon monoxide (CO) to α(Fe) 2 β(Ni) 2 , these resonances disappear at pH 6.5 to pH 8.5. On the other hand, the complementary hybrid α(Ni) 2 β(Fe-CO) 2 showed the 11 and 14 ppm resonances at low pH. Upon raising pH, the intensities of both resonances are reduced, although these changes are not synchronized. Electronic absorption spectra and hyperfine-shifted proton resonances indicate that the ligation of CO in the β(Fe) subunits induced changes in the coordination and spin states of Ni-PP in the α subunits. In a deoxy-like structure, the coordination of Ni-PP in the α subunits is predominantly in a low-spin (S = 0) four-coordination state, whereas in an oxy-like structure the contribution of a high-spin (S = 1) five-coordination state markedly increased. Ni-PP in the β subunits always takes a high-spin five-coordination state regardless of solution conditions and the state of ligation in the partner α(Fe) subunits. In the β(Ni) subunits, a significant downfield shift of the proximal histidyl N/sub δ/H resonance and a change in the absorption spectrum of Ni-PP were detected, upon changing the quaternary structure of the hybrid. The chemical shifts were analyzed in terms of the E11-Val methyls vs. the porphyrin rings in hybrid Hbs

  9. Materials presented at the 27 All-Polish Seminar on the Nuclear Magnetic Resonance and its application

    International Nuclear Information System (INIS)

    Hennel, J.W.

    1995-01-01

    In this report the contributions to the 27 All-Polish seminar on the Nuclear Magnetic Resonance and its Application are presented. They cover wide range of problems as NMR instrumentation, the NMR and spin relaxation theory, image analysis and computerized control systems for NMR spectrometers. The results of investigation using NMR on different scientific fields are also presented

  10. Analysis of cocondensation of melamine and urea through carbon 13 enriched formaldehyde with C-13 nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Bunichiro Tomita; Chung-Yun Hse

    1995-01-01

    The urea-formaldehyde (UF) resins, melamine-formaldehyde (MF) resins, and melamine-ureaformaldehyde (MUF) cocondensed resins were synthesized using the labeling method with 13C enriched formaldehyde under neutral conditions and their 13C-NMR (nuclear magnetic resonance) spectra were analyzed. The remarkable down-field...

  11. Analyses of cocondensation of melamine and urea through carbon 13 enriched formaldehyde with carbon 13 nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Tomita Bunchiro; Chung-Yun Hse

    1995-01-01

    The urea-formaldehyde (UF) resins, melamine-formaldehyde (MF) resins, and melamine-urea-formaldehyde (MUF) cocondensed resins were synthesized using the labeling method with 13C enriched formaldehyde unde neutral conditions and their 13C-NMR (nuclear magnetic resonance) spectra were analyzed. The remarkable down-field...

  12. Analysis on cocondensation of melamine and urea through carbon 13 enriched formaldehyde with carbon 13 nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Bunichiro Tomita; Chung-Yun Hse

    1995-01-01

    The urea-formaldehyde (UF) resins, melamine-formaldehyde (MF) resins, and melamine-urea-formaldehyde (MUF) cocondensed resins were synthesized using the labeling method of 13C enriched formaldehyde udner neutral conditions and their 13C-NMR (nuclear magnetic resonance) spectra were analyzed. The remarkable down-field shifts...

  13. Materials presented at the 26. All-Polish Seminar on the Nuclear Magnetic Resonance and its application

    International Nuclear Information System (INIS)

    Hennel, J.W.

    1994-01-01

    In this report the contributions to the 26. All-Polish seminar on the Nuclear Magnetic Resonance and its Application are presented. They cover wide range of problems as NMR instrumentation, the NMR and spin relaxation theory, image analysis and computerized control systems for NMR spectrometers. The results of investigation using NMR on different scientific fields are also presented

  14. Control of porphyrin biosynthesis in Rhodopseudomonas spheroides and Propionibacterium shermanii. A direct 13C nuclear-magnetic-resonance spectroscopy study.

    Science.gov (United States)

    Burton, G; Jordan, P M; MacKenzie, N E; Fagerness, P E; Scott, A I

    1981-01-01

    The facultative anaerobes Rhodopseudomonas spheroides and Propionibacterium shermanii were grown under anaerobic and aerobic conditions. The effect of light was studied with the photosynthetic R. spheroides, and the adaptation of both species to dark anaerobic life was monitored by direct observation of 5-amino[5-13C]laevulinic acid metabolism by using 13C nuclear-magnetic-resonance spectroscopy. PMID:6975620

  15. 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.

  16. 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

  17. Differential measurement of the earth's magnetic field by nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Robach, F.

    1966-12-01

    MNR transducers using proton dynamic polarisation allows to convert into a phase measurement any variation of the earth magnetic field. There exist several versions of the instrument corresponding to various models of MNR transducers, which the author analyses in detail, devoting an important place to influence of their alignment with respect to the earth's magnetic field. The sensibility obtained is of one hundredth of a gamma over a bandwidth of (0-0,1 Hz). - This instrument is designed for measuring field gradients in airborne magnetic surveying, for detecting nearly magnetic anomalies, and for distinguishing between nearly and distant magnetic phenomena. (author) [fr

  18. Dynamics of solid alanine by means of nuclear magnetic resonance relaxometry

    Science.gov (United States)

    Kubica-Misztal, A.; Rochowski, P.; Florek-Wojciechowska, M.; Kruk, D.

    2017-04-01

    1H nuclear magnetic resonance relaxometry was applied to investigate the dynamics of l-alanine in the solid phase (powder). The experimental studies were carried out in a very broad frequency range, covering four orders of magnitude—from 4 kHz to 40 MHz (referring to the 1H resonance frequency) in order to probe motional processes of much different time scales by a single experiment. To get access to the dynamics of different proton groups of alanine, the 1H spin-lattice relaxation measurements were performed for non-deuterated and partially deuterated alanine. The experiments were carried out in the temperature range of 293 K-370 K (non-deuterated alanine) and 318 K-370 K (partially deuterated alanine). As a result of a thorough theoretical analysis of the extensive set of experimental results, three motional processes occurring on different time scales are identified and quantitatively described. The slowest process occurs on a time scale of μs and it is attributed to the collective dynamics of a 3D hydrogen bond network of alanine, while the intermediate, attributed to the dynamics of the NH3 group, corresponds to the range of tenths of ns. The fast process describes the rotation of the CH3 group.

  19. Identification of a probable new adrenergic agonist by nuclear magnetic resonance and mass spectrometry

    International Nuclear Information System (INIS)

    Boatto, Gianpiero; Culeddu, Nicola; Testa, Cecilia; Neri, Bruno; Brambilla, Gianfranco; Barbosa, Jorge; Cruz, Clara

    2007-01-01

    In animal production, it is consolidated the synthesis and the illegal use of growth promoters of new generation, able to skip routine screening and confirmatory analysis. In this work it is reported the nuclear magnetic resonance (NMR) and the mass spectrometry identification of a probable new adrenergic drug found in a feed premix. The substance was selectively purified on alpha 1 acid glycoprotein affinity columns; then its structure was first achieved by recording the 13 C NMR spectrum that gave the total number of carbons of the molecule, successively sorted by DEPT experiments into quaternary, CH, CH 2 , and CH 3 groups. However, the complete assignments of all resonances were derived from the bi-dimensional analysis and the crucial indications from the 1 H- 13 C reverse experiments. Further characterisation was performed by atmospheric pressure chemical ionisation both in positive and negative ion mode, matching the molecular ion and the fragmentation pattern with those of most recently described new adrenergic agonists. After the loss of a ter-butylic group, the structure shows an internal symmetry along with the presence of Chlorine clusters. The proposed formula of the compound, the 8,8'-diamino-9,9'-dichloro-1-terbutyl-1,1',4,4-tetrahydro-5H,5'H-2,2'-bi -1-benzazepine-5,5'-dione, partially resembles that of Zilpaterol for the presence of a heterocyclic ring; Further work is in progress to characterise the structure-activity relationship

  20. Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging.

    Science.gov (United States)

    Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles; Costa, Fernando Ferreira; Silveira, Paulo Augusto Achucarro; Wood, John; Hamerschlak, Nelson

    2013-12-01

    To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions.

  1. Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil); Costa, Fernando Ferreira [Universidade Estadual de Campinas, Campinas, SP (Brazil); Silveira, Paulo Augusto Achucarro [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil); Wood, John [University of Southern California, California (United States); Hamerschlak, Nelson [Hospital Israelita Albert Einstein, São Paulo, SP (Brazil)

    2013-07-01

    To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions.

  2. Iron overload in a teenager with xerocytosis: the importance of nuclear magnetic resonance imaging

    International Nuclear Information System (INIS)

    Assis, Reijâne Alves de; Kassab, Carolina; Seguro, Fernanda Salles; Costa, Fernando Ferreira; Silveira, Paulo Augusto Achucarro; Wood, John; Hamerschlak, Nelson

    2013-01-01

    To report a case of iron overload secondary to xerocytosis, a rare disease in a teenager, diagnosed, by T2* magnetic resonance imaging. We report the case of a symptomatic patient with xerocytosis, a ferritin level of 350ng/mL and a significant cardiac iron overload. She was diagnosed by T2* magnetic resonance imaging and received chelation therapy Ektacytometric analysis confirmed the diagnosis of hereditary xerocytosis. Subsequent T2* magnetic resonance imaging demonstrated complete resolution of the iron overload in various organs, as a new echocardiography revealed a complete resolution of previous cardiac alterations. The patient remains in chelation therapy. Xerocytosis is a rare autosomal dominant genetic disorder characterized by dehydrated stomatocytosis. The patient may present with intense fatigue and iron overload. We suggest the regular use of T2* magnetic resonance imaging for the diagnosis and control of the response to iron chelation in xerocytosis, and we believe it can be used also in other hemolytic anemia requiring transfusions

  3. Recent developments in the food quality detected by non-invasive nuclear magnetic resonance technology.

    Science.gov (United States)

    Fan, Kai; Zhang, Min

    2018-02-16

    Nuclear magnetic resonance (NMR) is a rapid, accurate and non-invasive technology and widely used to detect the quality of food, particularly to fruits and vegetables, meat and aquatic products. This review is a survey of recent developments in experimental results for the quality of food on various NMR technologies in processing and storage over the past decade. Following a discussion of the quality discrimination and classification of food, analysis of food compositions and detection of physical, chemical, structural and microbiological properties of food are outlined. Owing to high cost, low detection limit and sensitivity, the professional knowledge involved and the safety issues related to the maintenance of the magnetic field, so far the practical applications are limited to detect small range of food. In order to promote applications for a broader range of foods further research and development efforts are needed to overcome the limitations of NMR in the detection process. The needs and opportunities for future research and developments are outlined.

  4. Advances and applications of dynamic-angle spinning nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Baltisberger, Jay Harvey [Univ. of California, Berkeley, CA (United States)

    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. Advances and applications of dynamic-angle spinning nuclear magnetic resonance

    International Nuclear Information System (INIS)

    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 87 Rb and 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

  6. Evaluation of surface nuclear magnetic resonance-estimated subsurface water content

    International Nuclear Information System (INIS)

    Mueller-Petke, M; Dlugosch, R; Yaramanci, U

    2011-01-01

    The technique of nuclear magnetic resonance (NMR) has found widespread use in geophysical applications for determining rock properties (e.g. porosity and permeability) and state variables (e.g. water content) or to distinguish between oil and water. NMR measurements are most commonly made in the laboratory and in boreholes. The technique of surface NMR (or magnetic resonance sounding (MRS)) also takes advantage of the NMR phenomenon, but by measuring subsurface rock properties from the surface using large coils of some tens of meters and reaching depths as much as 150 m. We give here a brief review of the current state of the art of forward modeling and inversion techniques. In laboratory NMR a calibration is used to convert measured signal amplitudes into water content. Surface NMR-measured amplitudes cannot be converted by a simple calibration. The water content is derived by comparing a measured amplitude with an amplitude calculated for a given subsurface water content model as input for a forward modeling that must account for all relevant physics. A convenient option to check whether the measured signals are reliable or the forward modeling accounts for all effects is to make measurements in a well-defined environment. Therefore, measurements on top of a frozen lake were made with the latest-generation surface NMR instruments. We found the measured amplitudes to be in agreement with the calculated amplitudes for a model of 100 % water content. Assuming then both the forward modeling and the measurement to be correct, the uncertainty of the model is calculated with only a few per cent based on the measurement uncertainty.

  7. Diffusion tensor analysis with nuclear magnetic resonance in human central nervous system

    International Nuclear Information System (INIS)

    Nakayama, Naoki

    1998-01-01

    Nuclear magnetic resonance has been used to measure the diffusivity of water molecules. In central nervous system, anisotropic diffusion, which is characterized by apparent diffusion tensor D app ξ , is thought to be related to neuronal fiber tract orientation. For precise observation of anisotropic diffusion, it is needed to determine the diagonal and off-diagonal elements of D app ξ . Once D app ξ is estimated from a series of diffusion weighted images, a tissue's orthotropic principal axes and diffusivity of each direction are determined from eigenvalues and eigenvectors of D app ξ . There are several methods to represent anisotropic diffusion with D app ξ . Examples are diffusion ellipsoids constructed in each voxel depicting both these principal axes and the mean diffusion length in these directions, trace invariant values and its mapping image, largest eigenvalue, and ratio of largest eigenvalue to the other eigenvalue. In this study, the author investigated practical procedure to analyze diffusion tensor D app ξ using both of spin-echo end echo-planer diffusion weighted imagings with 3-tesla magnetic resonance machine in human brain. The ellipsoid representation provided particularly useful information about microanatomy including neuronal fiber tract orientation and molecular mobility reflective of microstructure. Furthermore, in the lesion of Wallerian degeneration, the loss of anisotropy of local apparent diffusion was observed. It is suggested that the function of axons can be observed via degree of anisotropy of apparent diffusion. Consequently, diffusion tensor analysis is expected to be a powerful, noninvasive method capable of quantitative and functional evaluation of the central nervous system. (author)

  8. Nuclear magnetic resonance technology in acupoint catgut embedding therapy for the treatment of menopausal panic disorder: its applications

    Science.gov (United States)

    Chen, Gui-zhen; Zhang, Sha-sha; Xu, Yun-xiang; Wang, Xiao-yun

    2012-03-01

    Nuclear Magnetic Resonance (NMR) is a diagnostic method which is non-invasive and non-ionizing irradiative to the human body. It not only suits structural, but also functional imaging. The NMR technique develops rapidly in its application in life science, which has become the hotspot in recent years. Menopausal panic disorder (MPD) is a typical psychosomatic disease during climacteric period, which may affect physical and mental health. Looking for a convenient, effective, and safe method, which is free of toxic-side effects to control the disease, is a modern medical issue. Based on reviewing the etiology and pathogenesis of MPD according to dual traditional Chinese medicine (TCM) and western medicine, further analyzed the advantages and principles for selecting acupoint prescription by tonifying kidney and benefiting marrow therapy for acupoint catgut-embedding to this disease. The application of Nuclear Magnetic Resonance Spectroscopy (NMRS) and Magnetic Resonance Imaging (MRI) technologies in mechanism research on acupoint catgut embedding for the treatment of MPD was discussed. It's pointed out that this intervention method is safe and effective to treat MPD. Breakthrough will be achieved from the research of the selection of acupoint prescription and therapeutic mechanism of acupoint catgut embedding for the treatment of menopausal panic disorder by utilizing the Functional Nuclear Magnetic Resonance Imaging (fMRI) and Metabonomics technologies.

  9. Educational simulator app and web page for exploring Nuclear and Compass Magnetic Resonance

    DEFF Research Database (Denmark)

    Hanson, Lars G.

    , the Larmor equation, Nuclear MR, resonant excitation (linear and quadrature), and off-resonance effects. Methods and implementation: The simulator is a complete HTML5/JavaScript[1,2] rewrite of the JavaCompass[3] so it now executes in modern browsers with no additional software needed. Spin dynamics...

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

    Energy Technology Data Exchange (ETDEWEB)

    Yeninas, Steven Lee [Iowa State Univ., Ames, IA (United States)

    2013-01-01

    This thesis emphasizes two frequency-domain techniques which uniquely employ radio frequency (RF) excitations to investigate the static and dynamic properties of novel magnetic and superconducting materials.

  11. Pairwise additivity in the nuclear magnetic resonance interactions of atomic xenon.

    Science.gov (United States)

    Hanni, Matti; Lantto, Perttu; Vaara, Juha

    2009-04-14

    Nuclear magnetic resonance (NMR) of atomic (129/131)Xe is used as a versatile probe of the structure and dynamics of various host materials, due to the sensitivity of the Xe NMR parameters to intermolecular interactions. The principles governing this sensitivity can be investigated using the prototypic system of interacting Xe atoms. In the pairwise additive approximation (PAA), the binary NMR chemical shift, nuclear quadrupole coupling (NQC), and spin-rotation (SR) curves for the xenon dimer are utilized for fast and efficient evaluation of the corresponding NMR tensors in small xenon clusters Xe(n) (n = 2-12). If accurate, the preparametrized PAA enables the analysis of the NMR properties of xenon clusters, condensed xenon phases, and xenon gas without having to resort to electronic structure calculations of instantaneous configurations for n > 2. The binary parameters for Xe(2) at different internuclear distances were obtained at the nonrelativistic Hartree-Fock level of theory. Quantum-chemical (QC) calculations at the corresponding level were used to obtain the NMR parameters of the Xe(n) (n = 2-12) clusters at the equilibrium geometries. Comparison of PAA and QC data indicates that the direct use of the binary property curves of Xe(2) can be expected to be well-suited for the analysis of Xe NMR in the gaseous phase dominated by binary collisions. For use in condensed phases where many-body effects should be considered, effective binary property functions were fitted using the principal components of QC tensors from Xe(n) clusters. Particularly, the chemical shift in Xe(n) is strikingly well-described by the effective PAA. The coordination number Z of the Xe site is found to be the most important factor determining the chemical shift, with the largest shifts being found for high-symmetry sites with the largest Z. This is rationalized in terms of the density of virtual electronic states available for response to magnetic perturbations.

  12. Nuclear magnetic resonance study of charge transfer complex formation between Silver Nitrate and Benzylcyanide in Solvent Ethylene Glycol

    CERN Document Server

    Modarress, H

    2003-01-01

    The formation constant for charge transfer complexes between electron acceptor (AgNo sub 3) and electron donor benzylcyanide (C sub 6 H sub 5 -CH sub 2 -C ident to N) in solvent ethyleneglycol [(CH sub 2 OH) sub 2] has been evaluated by using the nuclear magnetic resonance chemical shifts of aromatic group of benzylcyanide measured against external references, tetramethylsilane, hexamethyldisilane and cyclohexane at 20 sup d ig sup C. The external referencing procedure eliminated the interference of internal reference in the course of complexation. The necessary bulk magnetic susceptibility corrections on the measured chemical shifts have been made. The solution nationalised and their effects on the formation constant have been considered and a new equation has been suggested to obtain the main ionic activity coefficient of AgNO sub 3 from nuclear magnetic resonance results. The mean ionic activity coefficient has been taken into account in the formation constant calculations. The results indicated that the a...

  13. Structural, dielectric, magnetic, and nuclear magnetic resonance studies of multiferroic Y-type hexaferrites

    Science.gov (United States)

    Khanduri, H.; Chandra Dimri, M.; Kooskora, H.; Heinmaa, I.; Viola, G.; Ning, H.; Reece, M. J.; Krustok, J.; Stern, R.

    2012-10-01

    The effect of strontium substitution on structural, magnetic, and dielectric properties of a multiferroic Y-type hexaferrite (chemical formula Ba2-xSrxMg2Fe12O22 with 0 ≤ x ≤ 2) was investigated. Y-type hexaferrite phase formation was not affected by strontium substitution for barium, in the range 0 ≤ x ≤ 1.5, confirmed by x-ray diffraction and Raman spectroscopy measured at room temperature. Two intermediate magnetic spin phase transitions (at tempertures TI and TII) and a ferrimagnetic-paramagnetic transition (at Curie temperature TC) were identified from the temperature dependence of the magnetic susceptibility. Magnetic transition temperatures (TI, TII, and TC) increased with increasing strontium content. Magnetic hysteresis measurements indicated that by increasing strontium concentration, the coercivity increases, while the saturation magnetization decreases. The 57Fe NMR spectrum of the Y-type hexaferrite measured at 5 K and in zero magnetic field showed remarkable differences compared to that of other hexaferrites due to their different number of tetrahedral and octahedral iron sites. The temperature and frequency dependence of the dielectric permittivity evidenced broad peaks with frequency dispersion in correspondence of the Curie temperature.

  14. New Methodology For Use in Rotating Field Nuclear MagneticResonance

    Energy Technology Data Exchange (ETDEWEB)

    Jachmann, Rebecca C. [Univ. of California, Berkeley, CA (United States)

    2007-05-18

    High-resolution NMR spectra of samples with anisotropicbroadening are simplified to their isotropic spectra by fast rotation ofthe sample at the magic angle 54.7 circ. This dissertation concerns thedevelopment of novel Nuclear Magnetic Resonance (NMR) methodologies basedwhich would rotate the magnetic field instead of the sample, rotatingfield NMR. It provides an over of the NMR concepts, procedures, andexperiments needed to understand the methodologies that will be used forrotating field NMR. A simple two-dimensional shimming method based onharmonic corrector rings which can provide arbitrary multiple ordershimming corrections were developed for rotating field systems, but couldbe used in shimming other systems as well. Those results demonstrate, forexample, that quadrupolar order shimming improves the linewidth by up toan order of magnitude. An additional order of magnitude reduction is inprinciple achievable by utilizing this shimming method for z-gradientcorrection and higher order xy gradients. A specialized pulse sequencefor the rotating field NMR experiment is under development. The pulsesequence allows for spinning away from the magic angle and spinningslower than the anisotropic broadening. This pulse sequence is acombination of the projected magic angle spinning (p-MAS) and magic angleturning (MAT) pulse sequences. This will be useful to rotating field NMRbecause there are limits on how fast a field can be spun and spin at themagic angle is difficult. One of the goals of this project is forrotating field NMR to be used on biological systems. The p-MAS pulsesequence was successfully tested on bovine tissue samples which suggeststhat it will be a viable methodology to use in a rotating field set up. Aside experiment on steering magnetic particle by MRI gradients was alsocarried out. Some movement was seen in these experiment, but for totalcontrol over steering further experiments would need to bedone.

  15. New Methodology For Use in Rotating Field Nuclear MagneticResonance

    Energy Technology Data Exchange (ETDEWEB)

    Jachmann, Rebecca C. [Univ. of California, Berkeley, CA (United States)

    2007-01-01

    High-resolution NMR spectra of samples with anisotropicbroadening are simplified to their isotropic spectra by fast rotation ofthe sample at the magic angle 54.7 circ. This dissertation concerns thedevelopment of novel Nuclear Magnetic Resonance (NMR) methodologies basedwhich would rotate the magnetic field instead of the sample, rotatingfield NMR. It provides an over of the NMR concepts, procedures, andexperiments needed to understand the methodologies that will be used forrotating field NMR. A simple two-dimensional shimming method based onharmonic corrector rings which can provide arbitrary multiple ordershimming corrections were developed for rotating field systems, but couldbe used in shimming other systems as well. Those results demonstrate, forexample, that quadrupolar order shimming improves the linewidth by up toan order of magnitude. An additional order of magnitude reduction is inprinciple achievable by utilizing this shimming method for z-gradientcorrection and higher order xy gradients. A specialized pulse sequencefor the rotating field NMR experiment is under development. The pulsesequence allows for spinning away from the magic angle and spinningslower than the anisotropic broadening. This pulse sequence is acombination of the projected magic angle spinning (p-MAS) and magic angleturning (MAT) pulse sequences. This will be useful to rotating field NMRbecause there are limits on how fast a field can be spun and spin at themagic angle is difficult. One of the goals of this project is forrotating field NMR to be used on biological systems. The p-MAS pulsesequence was successfully tested on bovine tissue samples which suggeststhat it will be a viable methodology to use in a rotating field set up. Aside experiment on steering magnetic particle by MRI gradients was alsocarried out. Some movement was seen in these experiment, but for totalcontrol over steering further experiments would need to bedone.

  16. Profiling of some amoxicillin drugs in Ghana using Nuclear Magnetic Resonance Spectroscopy

    International Nuclear Information System (INIS)

    Aboagye, Mary Esi

    2016-07-01

    The prevalence of counterfeit drugs is seen as a problem faced in both developed and developing countries where Ghana is not an exception. Antibiotics are amongst the most counterfeit drugs in developing countries. What is less understood is that there are inadequate and ineffective quality control procedures in monitoring of drugs manufactured and imported into the country. This research work is aimed at contributing towards the development of routine analytical procedures that will facilitate distinguishing between fake and genuine amoxicillin drugs. This was accomplished by elaborating operating procedures for the analysis of specific antibiotic drug using nuclear magnetic resonance (NMR) spectroscopy and establishing the NMR profile of active principal ingredient (API) of amoxicillin drug and assessing the API in samples of amoxicillin drug purchased in Accra. Three brands of amoxicillin samples consisting of imported amoxicillin, National Health Insurance Scheme (NHIS) amoxicillin were purchased from a licensed pharmacy shop in Accra and amoxicillin purchased from Okaishie market were used for analysis. Standard amoxicillin known as amoxicillin trihydrate obtained from Ernest Chemist in Accra was also used analysed. The authenticity of the drugs was analysed using 1H and C-13 nuclear magnetic resonance spectroscopy. Upon analysis H-NMR and C-13 NMR profiles were obtained for the API (Amoxicillin Trihydrate) in amoxicillin. H NMR showed relatively higher sensitivities for the drug than C-13 NMR therefore analysis for the antibiotics was focused on H-NMR. After analysis amoxicillin trihydrate was identified as the API. A procedure suitable for NMR sample preparation of amoxicillin for NMR analysis was elaborated. Dimethyl sulfoxide was identified as a suitable solvent for the experiments. The samples were prepared by dissolving suitable quantities (10mg) of the drug in (1ml) of the chosen solvent. H-NMR technique was used to provide an NMR profile for the Active

  17. Probing beer aging chemistry by nuclear magnetic resonance and multivariate analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, J.A. [CICECO-Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Barros, A.S. [QOPNA-Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Carvalho, B.; Brandao, T. [UNICER, Bebidas de Portugal, Leca do Balio, 4466-955, S. Mamede de Infesta (Portugal); Gil, Ana M., E-mail: agil@ua.pt [CICECO-Department of Chemistry, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)

    2011-09-30

    Graphical abstract: The use of nuclear magnetic resonance (NMR) metabonomics for monitoring the chemical changes occurring in beer exposed to forced aging (at 45 deg. C for up to 18 days) is described. Both principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were applied to the NMR spectra of beer recorded as a function of aging and an aging trend was observed. Inspection of PLS-DA loadings and peak integration revealed the importance of well known markers (e.g. 5-HMF) as well as of other compounds: amino acids, higher alcohols, organic acids, dextrins and some still unassigned spin systems. 2D correlation analysis enabled relevant compound variations to be confirmed and inter-compound correlations to be assessed, thus offering improved insight into the chemical aspects of beer aging. Highlights: {center_dot} Use of NMR metabonomics for monitoring the chemical changes occurring in beer exposed to forced aging. {center_dot} Compositional variations evaluated by principal component analysis and partial least squares-discriminant analysis. {center_dot} Results reveal importance of known markers and other compounds: amino and organic acids, higher alcohols, dextrins. {center_dot} 2D correlation analysis reveals inter-compound relationships, offering insight into beer aging chemistry. - Abstract: This paper describes the use of nuclear magnetic resonance (NMR) spectroscopy, in tandem with multivariate analysis (MVA), for monitoring the chemical changes occurring in a lager beer exposed to forced aging (at 45 deg. C for up to 18 days). To evaluate the resulting compositional variations, both principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were applied to the NMR spectra of beer recorded as a function of aging and a clear aging trend was observed. Inspection of PLS-DA loadings and peak integration enabled the changing compounds to be identified, revealing the importance of well known

  18. Probing beer aging chemistry by nuclear magnetic resonance and multivariate analysis

    International Nuclear Information System (INIS)

    Rodrigues, J.A.; Barros, A.S.; Carvalho, B.; Brandao, T.; Gil, Ana M.

    2011-01-01

    Graphical abstract: The use of nuclear magnetic resonance (NMR) metabonomics for monitoring the chemical changes occurring in beer exposed to forced aging (at 45 deg. C for up to 18 days) is described. Both principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were applied to the NMR spectra of beer recorded as a function of aging and an aging trend was observed. Inspection of PLS-DA loadings and peak integration revealed the importance of well known markers (e.g. 5-HMF) as well as of other compounds: amino acids, higher alcohols, organic acids, dextrins and some still unassigned spin systems. 2D correlation analysis enabled relevant compound variations to be confirmed and inter-compound correlations to be assessed, thus offering improved insight into the chemical aspects of beer aging. Highlights: · Use of NMR metabonomics for monitoring the chemical changes occurring in beer exposed to forced aging. · Compositional variations evaluated by principal component analysis and partial least squares-discriminant analysis. · Results reveal importance of known markers and other compounds: amino and organic acids, higher alcohols, dextrins. · 2D correlation analysis reveals inter-compound relationships, offering insight into beer aging chemistry. - Abstract: This paper describes the use of nuclear magnetic resonance (NMR) spectroscopy, in tandem with multivariate analysis (MVA), for monitoring the chemical changes occurring in a lager beer exposed to forced aging (at 45 deg. C for up to 18 days). To evaluate the resulting compositional variations, both principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were applied to the NMR spectra of beer recorded as a function of aging and a clear aging trend was observed. Inspection of PLS-DA loadings and peak integration enabled the changing compounds to be identified, revealing the importance of well known markers such as 5-hydroxymethylfurfural (5

  19. Detection of Hydroxyl and Perhydroxyl Radical Generation from Bleaching Agents with Nuclear Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Sharma, Himanshu; Sharma, Divya S

    Children/adolescent's orodental structures are different in anatomy and physiology from that of adults, therefore require special attention for bleaching with oxidative materials. Hydroxyl radical (OH . ) generation from bleaching agents has been considered directly related to both its clinical efficacy and hazardous effect on orodental structures. Nonetheless bleaching agents, indirectly releasing hydrogen peroxide (H 2 O 2 ), are considered safer yet clinically efficient. Apart from OH . , perhydroxyl radicals (HO 2 . ) too, were detected in bleaching chemistry but not yet in dentistry. Therefore, the study aims to detect the OH . and HO 2 . from bleaching agents with their relative integral value (RIV) using 31 P nuclear magnetic resonance ( 31 PNMR) spectroscope. Radicals were generated with UV light in 30% H 2 O 2 , 35% carbamide peroxide (CP), sodium perborate tetrahydrate (SPT) and; neutral and alkaline 30% H 2 O 2 . Radicals were spin-trapped with DIPPMPO in NMR tubes for each test agents as a function of time (0, 1, 2, 3min) at their original pH. Peaks were detected for OH . and HO 2 . on NMR spectrograph. RIV were read and compared for individual radicals detected. Only OH . were detected from acidic and neutral bleaching agent (30% acidic and neutral H 2 O 2 , 35%CP); both HO 2 . and OH . from 30% alkaline H 2 O 2 ; while only HO 2 . from more alkaline SPT. RIV for OH . was maximum at 1min irradiation of acidic 30%H 2 O 2 and 35%CP and minimum at 1min irradiation of neutral 30%H 2 O 2 . RIV for HO 2 . was maximum at 0min irradiation of alkaline 30%H 2 O 2 and minimum at 2min irradiation of SPT. The bleaching agents having pH- neutral and acidic were always associated with OH . ; weak alkaline with both OH . and HO 2 . ; and strong alkaline with HO 2 . only. It is recommended to check the pH of the bleaching agents and if found acidic, should be made alkaline to minimize oxidative damage to enamel itself and then to pulp/periodontal tissues. H 2 O 2

  20. 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...

  1. Identification of a probable new adrenergic agonist by nuclear magnetic resonance and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Boatto, Gianpiero [Department of Toxicological Chemistry, University of Sassari, Sassari (Italy); Culeddu, Nicola [CNR Biomolecular Chemistry Institute, Sassari (Italy); Testa, Cecilia [IZS della Sardegna, Sassari (Italy); Neri, Bruno [IZS delle Regioni Lazio e Toscana, Rome (Italy); Brambilla, Gianfranco [Istituto Superiore di Sanita, Environment Department, Toxicological Chemistry Unit, Rome (Italy)]. E-mail: g.brambi@iss.it; Barbosa, Jorge [LNIV, Lisbon (Portugal); Cruz, Clara [LNIV, Lisbon (Portugal)

    2007-03-14

    In animal production, it is consolidated the synthesis and the illegal use of growth promoters of new generation, able to skip routine screening and confirmatory analysis. In this work it is reported the nuclear magnetic resonance (NMR) and the mass spectrometry identification of a probable new adrenergic drug found in a feed premix. The substance was selectively purified on alpha 1 acid glycoprotein affinity columns; then its structure was first achieved by recording the {sup 13}C NMR spectrum that gave the total number of carbons of the molecule, successively sorted by DEPT experiments into quaternary, CH, CH{sub 2}, and CH{sub 3} groups. However, the complete assignments of all resonances were derived from the bi-dimensional analysis and the crucial indications from the {sup 1}H-{sup 13}C reverse experiments. Further characterisation was performed by atmospheric pressure chemical ionisation both in positive and negative ion mode, matching the molecular ion and the fragmentation pattern with those of most recently described new adrenergic agonists. After the loss of a ter-butylic group, the structure shows an internal symmetry along with the presence of Chlorine clusters. The proposed formula of the compound, the 8,8'-diamino-9,9'-dichloro-1-terbutyl-1,1',4,4-tetrahydro-5H,5'H-2,2'-bi -1-benzazepine-5,5'-dione, partially resembles that of Zilpaterol for the presence of a heterocyclic ring; Further work is in progress to characterise the structure-activity relationship.

  2. Susceptibility effects in nuclear magnetic resonance imaging; Suszeptibilitaetseffekte in der Kernspinresonanzbildgebung

    Energy Technology Data Exchange (ETDEWEB)

    Ziener, Christian Herbert

    2008-07-01

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

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

    International Nuclear Information System (INIS)

    Khatib, Alfi; Wilson, Erica G.; Kim, Hye Kyong; Lefeber, Alfons W.M.; Erkelens, Cornelis; Choi, Young Hae; Verpoorte, Robert

    2006-01-01

    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. 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 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 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

  4. Fast determination of beef quality parameters with time-domain nuclear magnetic resonance spectroscopy and chemometrics.

    Science.gov (United States)

    Pereira, Fabíola Manhas Verbi; Bertelli Pflanzer, Sérgio; Gomig, Thaísa; Lugnani Gomes, Carolina; de Felício, Pedro Eduardo; Colnago, Luiz Alberto

    2013-04-15

    The noteworthy of this study is to predict seven quality parameters for beef samples using time-domain nuclear magnetic resonance (TD-NMR) relaxometry data and multivariate models. Samples from 61 Bonsmara heifers were separated into five groups based on genetic (breeding composition) and feed system (grain and grass feed). Seven sample parameters were analyzed by reference methods; among them, three sensorial parameters, flavor, juiciness and tenderness and four physicochemical parameters, cooking loss, fat and moisture content and instrumental tenderness using Warner Bratzler shear force (WBSF). The raw beef samples of the same animals were analyzed by TD-NMR relaxometry using Carr-Purcell-Meiboom-Gill (CPMG) and Continuous Wave-Free Precession (CWFP) sequences. Regression models computed by partial least squares (PLS) chemometric technique using CPMG and CWFP data and the results of the classical analysis were constructed. The results allowed for the prediction of aforementioned seven properties. The predictive ability of the method was evaluated using the root mean square error (RMSE) for the calibration (RMSEC) and validation (RMSEP) data sets. The reference and predicted values showed no significant differences at a 95% confidence level. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. The omics era: what can nuclear magnetic resonance tell us on metabolomics?

    Directory of Open Access Journals (Sweden)

    Franca Castiglione

    2018-02-01

    Full Text Available A brief overview of the potentiality and use of the metabolic fingerprint of a system or biological process is here proposed. The information on the type, quantity and variation of the pool of metabolites and its relationship with a given biological process is commonly referred to as metabolomics. One powerful analytical approach to the detection and quantitation of metabolites is by Nuclear Magnetic Resonance Spectroscopy (NMR. Additionally, the recently introduced High Resolution Magic Angle Spinning (HR-MAS NMR approach improved dramatically the potentiality of the method allowing direct sampling of ex vivo specimens, such as tissues and cells, without any pre-treatment or extraction steps. The NMR data can be processed towards the target or non-target analysis of the metabolites. The former passes through the identification of all the metabolites, the latter adopts a multivariate statistical approach such as Principal Components Analysis. In this article, the main methodological points of NMR analysis with multivariate statistics are briefly outlined and discussed. A final case-study on the discrimination of healthy and neoplastic tissues via HR-MAS NMR metabolomics is reported as a paradigmatic application.

  6. Microstructural Investigation and MolecularWeight Determination of 1, 2-Polybutadiene by Nuclear Magnetic Resonance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Farshid Ziaee

    2013-01-01

    Full Text Available In this research, the microstructural of low molecular weight 1,2-polybutadiene (1,2-PBD was conducted by 1H and 13C nuclear magnetic resonance spectroscopy (NMR to determine the isomeric contents of 1,4-cis, 1,4-trans and 1,2-vinyl in 1,2-PBD polymer structures. Number average molecular weight for low molecular weight 1,2-PBD was measured by NMR techniques and the results were compared with gel permeation chromatography. Due to the presence of methyl end group and its comparison with repeating units in 1,2-PBD microstructure, the number average molecular weight was calculated by NMR techniques. For calculation of surface areas, carbon and protons of methyl groups were characterized using distortion enhancement by polarization transfer (DEPT methods. For proton assignment of methyl end groups in 1H NMR spectral analysis the heteronuclear multiple quantum coherence (HMQC method was employed. Finally, stereoregularity and tacticity of 1,2-PBD were investigated through pentad and heptad sequences splitting of olefinic methylene and methine carbons pendant groups with various NMR acquisition temperatures from 20 to 50oC. 13C NMR spectra showed that with increasing of NMR acquisition temperature, the number of split peaks of two olefinic carbons increased.

  7. Characterization of proton exchange membrane materials for fuel cells by solid state nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Zueqian [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    Solid-state nuclear magnetic resonance (NMR) has been used to explore the nanometer-scale structure of Nafion, the widely used fuel cell membrane, and its composites. We have shown that solid-state NMR can characterize chemical structure and composition, domain size and morphology, internuclear distances, molecular dynamics, etc. The newly-developed water channel model of Nafion has been confirmed, and important characteristic length-scales established. Nafion-based organic and inorganic composites with special properties have also been characterized and their structures elucidated. The morphology of Nafion varies with hydration level, and is reflected in the changes in surface-to-volume (S/V) ratio of the polymer obtained by small-angle X-ray scattering (SAXS). The S/V ratios of different Nafion models have been evaluated numerically. It has been found that only the water channel model gives the measured S/V ratios in the normal hydration range of a working fuel cell, while dispersed water molecules and polymer ribbons account for the structures at low and high hydration levels, respectively.

  8. Probing gender-specific metabolism differences in humans by nuclear magnetic resonance-based metabonomics.

    Science.gov (United States)

    Kochhar, Sunil; Jacobs, Doris M; Ramadan, Ziad; Berruex, France; Fuerholz, Andreas; Fay, Laurent B

    2006-05-15

    The measurement of metabolite profiles that are interpreted to yield biomarkers using multivariate data analysis is now a well-established approach for gaining an improved understanding of the impact of genetic modifications, toxicological and therapeutic interventions, and exposure to stimuli (e.g., noxious agents, stressors, nutrients) on the network of transcripts, proteins, and metabolites present in cells, tissues, or whole organisms. This has been termed metabonomics. In this study, multivariate analysis of (1)H nuclear magnetic resonance (NMR) spectra of metabolite profiles of urine and plasma from 150 healthy humans revealed that in young people and/or individuals with low body mass indexes, females had higher rates of lipid biosynthesis than did males, whereas males had higher rates of protein turnover than did females. With increasing age, overall lipid biosynthesis decreased in females, whereas metabolism increasingly favored lipid synthesis over protein turnover in males. By relating the derived metabonomic data to known metabolic pathways and published biochemical data, it appears that females synthesize relatively more lipoproteins and unsaturated lipids than do males. Furthermore, the changes in lipid biosynthesis and urinary citrate excretion in females showed a positive correlation. Estrogen most likely plays an essential role in the regulation of, and communication between, protein and lipid biosynthesis by controlling pH in mitochondria and the cytoplasm and hence the observed altered citrate levels.

  9. Electronic properties of Cs-intercalated single-walled carbon nanotubes derived from nuclear magnetic resonance

    KAUST Repository

    Abou-Hamad, E

    2011-05-24

    We report on the electronic properties of Cs-intercalated single-walled carbon nanotubes (SWNTs). A detailed analysis of the 13C and 133Cs nuclear magnetic resonance (NMR) spectra reveals an increased metallization of the pristine SWNTs under Cs intercalation. The \\'metallization\\' of CsxC materials where x=0–0.144 is evidenced from the increased local electronic density of states (DOS) n(EF) at the Fermi level of the SWNTs as determined from spin–lattice relaxation measurements. In particular, there are two distinct electronic phases called α and β and the transition between these occurs around x=0.05. The electronic DOS at the Fermi level increases monotonically at low intercalation levels x<0.05 (α-phase), whereas it reaches a plateau in the range 0.05≤x≤0.143 at high intercalation levels (β-phase). The new β-phase is accompanied by a hybridization of Cs(6s) orbitals with C(sp2) orbitals of the SWNTs. In both phases, two types of metallic nanotubes are found with a low and a high local n(EF), corresponding to different local electronic band structures of the SWNTs.

  10. Assessment of structural changes of human teeth by low-field nuclear magnetic resonance (NMR)

    International Nuclear Information System (INIS)

    Ni, Qingwen; Chen, Shuo

    2010-01-01

    A technique of low-field pulsed proton nuclear magnetic resonance (NMR) spin relaxation is described for assessment of age-related structural changes (dentin and pulp) of human teeth in vitro. The technique involves spin–spin relaxation measurement and inversion spin–spin spectral analysis methods. The spin–spin relaxation decay curve is converted into a T 2 distribution spectrum by a sum of single exponential decays. The NMR spectra from the extracted dentin-portion-only and dental pulp-cells-only were compared with the whole extracted teeth spectra, for the dentin and pulp peak assignments. While dentin and pulp are highly significant parameters in determining tooth quality, variations in these parameters with age can be used as an effective tool for estimating tooth quality. Here we propose an NMR calibration method—the ratio of the amount of dentin to the amount of pulp obtained from NMR T 2 distribution spectra can be used for measuring the age-related structural changes in teeth while eliminating any variations in size of teeth. Eight teeth (third molars) extracted from humans, aged among 17–67 years old, were tested in this study. It is found that the intensity ratio of dentin to pulp sensitively changes from 0.48 to 3.2 approaching a linear growth with age. This indicates that age-related structural changes in human teeth can be detected using the low-field NMR technique

  11. Nuclear magnetic resonance imaging in a case of facial myokymia with multiple sclerosis

    International Nuclear Information System (INIS)

    Kojima, Shigeyuki; Yagishita, Toshiyuki; Kita, Kohei; Hirayama, Keizo; Ikehira, Hiroo; Fukuda, Nobuo; Tateno, Yukio.

    1985-01-01

    A 59-year-old female of facial myokymia with multiple sclerosis was reported. In this case, facial myokymia appeared at the same time as the first attack of multiple sclerosis, in association with paroxysmal pain and desesthesia of the neck, painful tonic seizures of the right upper and lower extremities and cervical transverse myelopathy. The facial myokymia consisted of grossly visible, continuous, fine and worm-like movement, which often began in the area of the left orbicularis oculi and spread to the other facial muscles on one side. Electromyographic studies revealed grouping of motor units and continuous spontaneous rhythmic discharges in the left orbicularis oris suggesting facial myokymia, but there were no abnormalities on voluntary contraction. Sometimes doublet or multiplet patterns occurred while at other times the bursts were of single motor potential. The respective frequencies were 3-4/sec and 40-50/sec. There was no evidence of fibrillation. The facial myokymia disappeared after 4-8 weeks of administration of prednisolone and did not recur. In the remission stage after disappearance of the facial myokymia, nuclear magnetic resonance (NMR) imaging by the inversion recovery method demonstrated low intensity demyelinated plaque in the left lateral tegmentum of the inferior pons, which was responsible for the facial myokymia, but X-ray computed tomography revealed no pathological findings. The demyelinated plaque demonstrated by NMR imaging seemed to be located in the infranuclear area of the facial nerve nucleus and to involve the intramedurally root. (J.P.N.)

  12. Determination of scutellarin in breviscapine preparations using quantitative proton nuclear magnetic resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Zhenzuo Jiang

    2016-04-01

    Full Text Available The objective of the present study was to develop the selection criteria of proton signals for the determination of scutellarin using quantitative nuclear magnetic resonance (qNMR, which is the main bioactive compound in breviscapine preparations for the treatment of cerebrovascular disease. The methyl singlet signal of 3-(trimethylsilylpropionic-2,2,3,3-d4 acid sodium salt was selected as the internal standard for quantification. The molar concentration of scutellarin was determined by employing different proton signals. To obtain optimum proton signals for the quantification, different combinations of proton signals were investigated according to two selection criteria: the recovery rate of qNMR method and quantitative results compared with those obtained with ultra-performance liquid chromatography. As a result, the chemical shift of H-2′ and H-6′ at δ 7.88 was demonstrated as the most suitable signal with excellent linearity range, precision, and recovery for determining scutellarin in breviscapine preparations from different manufacturers, batch numbers, and dosage forms. Hierarchical cluster analysis was employed to evaluate the determination results. The results demonstrated that the selection criteria of proton signals established in this work were reliable for the qNMR study of scutellarin in breviscapine preparations.

  13. Anti-saturation system for surface nuclear magnetic resonance in efficient groundwater detection

    Science.gov (United States)

    Lin, Jun; Zhang, Yang; Yang, Yujing; Sun, Yong; Lin, Tingting

    2017-06-01

    Compared to other geophysical techniques, the surface nuclear magnetic resonance (SNMR) method could provide unique insights into the hydrologic properties of groundwater in the subsurface. However, the SNMR signal is in the order of nanovolts (10-9 V), and the complex environmental noise, i.e., the spike and the harmony noise (10-4 V), can reach up to 105 times the signal amplitude. Saturation of the amplifier is therefore a serious problem in current SNMR systems. In this study, we propose an anti-saturation method based on an instantaneous floating-point amplifier. The gain of a programmable amplifier is controlled by the value of the input signal. A regulating speed of 50 kS/s is thus achieved to satisfy the self-adaptive adjustment of the real-time SNMR system, which replaces the original man-made setting gain. A large dynamic range of 192.65 dB with a 24-bit high speed analog-digital converter module is then implemented. Compared to traditional SNMR instruments, whose magnification factor is fixed during the experiment, our system can effectively inhibit the distortion of the SNMR signal in both laboratory and field settings. Furthermore, an improved SNR, which is realized by the real-time SNMR system, enables the accurate inversion of the aquifer. Our study broadens the applicability of SNMR systems to use in and around developed areas.

  14. Substructure elucidation and chemical shift estimation using the nuclear magnetic resonance spectral database

    International Nuclear Information System (INIS)

    Yamamoto, Osamu; Hayamizu, Kikuko; Yanagisawa, Masaru

    1989-01-01

    A computer system for substructure elucidation and chemical shift estimation by the use of nuclear magnetic resonance (NMR) spectra is described. In this system, substructures in a molecule can be elucidated by specifying chemical shift values or ranges, and conversely chemical shift values can be estimated by specifying substructures for both 1 H- and 13 C-NMR data. The retrieval of data can be performed interactively between 1 H- and 13 C-NMR data. It is possible to estimate all chemical shift values for a compound by giving its chemical structure. The search file for these purposes is created for signals (or signal groups) from a large number of 1 H- and 13 C-NMR spectra in our database. The information contained in the search file consists of substructures and the corresponding chemical shift values. A line notation system has been developed to plot chemical structures with spectral assignments of NMR signals and to extract substructures corresponding to particular chemical shift values. (author)

  15. Nuclear magnetic resonance studies of the regulation of the pentose phosphate pathway

    Energy Technology Data Exchange (ETDEWEB)

    Bolo, N.R.

    1991-11-01

    The goal of this work is to investigate the potential for and limitations of in vivo nuclear magnetic resonance (NMR) spectroscopy for quantitation of glucose flux through the pentose phosphate pathway (shunt). Interest in the shunt is motivated by the possibility that its activity may be greatly increased in cancer and in the pathological states of cardiac and cerebral ischemia. The ability to dynamically monitor flux through the pentose shunt can give new knowledge about metabolism in pathological states. {sup 13}C NMR spectroscopy was used to monitor shunt activity by determination of the ratios of ({sup 13}C-4) to ({sup 13}C-5)-glutamate, ({sup 13}C-3) to ({sup 13}C-2)-alanine or ({sup 13}C-3) to ({sup 13}C-2)-lactate produced when ({sup 13}C-2)-glucose is infused. These methods provide measures of the effect of oxidative stresses on shunt activity in systems ranging from cell free enzyme-substrate preparations to cell suspensions and whole animals. In anaerobic cell free preparations, the fraction of glucose flux through the shunt was monitored with a time resolution of 3 minutes. This work predicts the potential for in vivo human studies of pentose phosphate pathway activity based on the mathematical simulation of the {sup 13}C fractional enrichments of C4 and C5-glutamate as a function of shunt activity and on the signal-to- noise ratio acquired in {sup 13}C NMR human studies from the current literature.

  16. 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.

  17. Nuclear magnetic resonance provides a quantitative description of protein conformational flexibility on physiologically important time scales.

    Science.gov (United States)

    Salmon, Loïc; Bouvignies, Guillaume; Markwick, Phineus; Blackledge, Martin

    2011-04-12

    A complete description of biomolecular activity requires an understanding of the nature and the role of protein conformational dynamics. In recent years, novel nuclear magnetic resonance-based techniques that provide hitherto inaccessible detail concerning biomolecular motions occurring on physiologically important time scales have emerged. Residual dipolar couplings (RDCs) provide precise information about time- and ensemble-averaged structural and dynamic processes with correlation times up to the millisecond and thereby encode key information for understanding biological activity. In this review, we present the application of two very different approaches to the quantitative description of protein motion using RDCs. The first is purely analytical, describing backbone dynamics in terms of diffusive motions of each peptide plane, using extensive statistical analysis to validate the proposed dynamic modes. The second is based on restraint-free accelerated molecular dynamics simulation, providing statistically sampled free energy-weighted ensembles that describe conformational fluctuations occurring on time scales from pico- to milliseconds, at atomic resolution. Remarkably, the results from these two approaches converge closely in terms of distribution and absolute amplitude of motions, suggesting that this kind of combination of analytical and numerical models is now capable of providing a unified description of protein conformational dynamics in solution.

  18. Shale characteristics impact on Nuclear Magnetic Resonance (NMR fluid typing methods and correlations

    Directory of Open Access Journals (Sweden)

    Mohamed Mehana

    2016-06-01

    Full Text Available The development of shale reservoirs has brought a paradigm shift in the worldwide energy equation. This entails developing robust techniques to properly evaluate and unlock the potential of those reservoirs. The application of Nuclear Magnetic Resonance techniques in fluid typing and properties estimation is well-developed in conventional reservoirs. However, Shale reservoirs characteristics like pore size, organic matter, clay content, wettability, adsorption, and mineralogy would limit the applicability of the used interpretation methods and correlation. Some of these limitations include the inapplicability of the controlling equations that were derived assuming fast relaxation regime, the overlap of different fluids peaks and the lack of robust correlation to estimate fluid properties in shale. This study presents a state-of-the-art review of the main contributions presented on fluid typing methods and correlations in both experimental and theoretical side. The study involves Dual Tw, Dual Te, and doping agent's application, T1-T2, D-T2 and T2sec vs. T1/T2 methods. In addition, fluid properties estimation such as density, viscosity and the gas-oil ratio is discussed. This study investigates the applicability of these methods along with a study of the current fluid properties correlations and their limitations. Moreover, it recommends the appropriate method and correlation which are capable of tackling shale heterogeneity.

  19. Investigation of stroke in sickle cell disease by [sup 1]H nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Z. (Dept. of Radiology, Pennsylvania Univ., Philadelphia, PA (United States)); Bogdan, A.R. (Siemens Medical Systems, Aston, PA (United States)); Zimmermann, R.A. (Dept. of Radiology, Pennsylvania Univ., Philadelphia, PA (United States)); Gusnard, D.A. (Dept. of Radiology, Pennsylvania Univ., Philadelphia, PA (United States)); Leigh, J.S. (Dept. of Radiology, Pennsylvania Univ., Philadelphia, PA (United States)); Ohene-Frempong, K. (Div. of Hematology, Children' s Hospital, Pennsylvania Univ., Philadelphia, PA (United States))

    1992-12-01

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

  20. Nuclear magnetic resonance studies of the regulation of the pentose phosphate pathway

    International Nuclear Information System (INIS)

    Bolo, N.R.

    1991-11-01

    The goal of this work is to investigate the potential for and limitations of in vivo nuclear magnetic resonance (NMR) spectroscopy for quantitation of glucose flux through the pentose phosphate pathway (shunt). Interest in the shunt is motivated by the possibility that its activity may be greatly increased in cancer and in the pathological states of cardiac and cerebral ischemia. The ability to dynamically monitor flux through the pentose shunt can give new knowledge about metabolism in pathological states. 13 C NMR spectroscopy was used to monitor shunt activity by determination of the ratios of [ 13 C-4] to [ 13 C-5]-glutamate, [ 13 C-3] to [ 13 C-2]-alanine or [ 13 C-3] to [ 13 C-2]-lactate produced when [ 13 C-2]-glucose is infused. These methods provide measures of the effect of oxidative stresses on shunt activity in systems ranging from cell free enzyme-substrate preparations to cell suspensions and whole animals. In anaerobic cell free preparations, the fraction of glucose flux through the shunt was monitored with a time resolution of 3 minutes. This work predicts the potential for in vivo human studies of pentose phosphate pathway activity based on the mathematical simulation of the 13 C fractional enrichments of C4 and C5-glutamate as a function of shunt activity and on the signal-to- noise ratio acquired in 13 C NMR human studies from the current literature

  1. Structures of peptide families by nuclear magnetic resonance spectroscopy and distance geometry

    Energy Technology Data Exchange (ETDEWEB)

    Pease, J.H.

    1989-12-01

    The three dimensional structures of several small peptides were determined using a combination of {sup 1}H nuclear magnetic resonance (NMR) and distance geometry calculations. These techniques were found to be particularly helpful for analyzing structural differences between related peptides since all of the peptides' {sup 1}H NMR spectra are very similar. The structures of peptides from two separate classes are presented. Peptides in the first class are related to apamin, an 18 amino acid peptide toxin from honey bee venom. The {sup 1}H NMR assignments and secondary structure determination of apamin were done previously. Quantitative NMR measurements and distance geometry calculations were done to calculate apamin's three dimensional structure. Peptides in the second class are 48 amino acid toxins from the sea anemone Radianthus paumotensis. The {sup 1}H NMR assignments of toxin II were done previously. The {sup 1}H NMR assignments of toxin III and the distance geometry calculations for both peptides are presented.

  2. Nuclear Magnetic Resonance-Based Structural Characterization and Backbone Dynamics of Recombinant Bee Venom Melittin.

    Science.gov (United States)

    Ramirez, Lisa; Shekhtman, Alexander; Pande, Jayanti

    2018-04-30

    In recent years, there has been a resurgence of interest in melittin and its variants as their therapeutic potential has become increasingly evident. Melittin is a 26-residue peptide and a toxic component of honey bee venom. The versatility of melittin in interacting with various biological substrates, such as membranes, glycosaminoglycans, and a variety of proteins, has inspired a slew of studies that aim to improve our understanding of the structural basis of such interactions. However, these studies have largely focused on melittin solutions at high concentrations (>1 mM), even though melittin is generally effective at lower (micromolar) concentrations. Here we present high-resolution nuclear magnetic resonance studies in the lower-concentration regime using a novel method to produce isotope-labeled ( 15 N and 13 C) recombinant melittin. We provide residue-specific structural characterization of melittin in dilute aqueous solution and in 2,2,2-trifluoroethanol/water mixtures, which mimic melittin structure-function and interactions in aqueous and membrane-like environments, respectively. We find that the cis-trans isomerization of Pro14 is key to changes in the secondary structure of melittin. Thus, this study provides residue-specific structural information about melittin in the free state and in a model of the substrate-bound state. These results, taken together with published work from other laboratories, reveal the peptide's structural versatility that resembles that of intrinsically disordered proteins and peptides.

  3. Revealing the metabolome of animal tissues using 1H nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Viant, Mark R

    2007-01-01

    The measurement of tissue-specific metabolic fingerprints can be of particular interest when investigating disease processes, mechanisms of toxicity, or when knowledge of the metabolic interactions between different organs is required. This chapter presents several optimized protocols for the extraction of metabolites from animal tissues, their analysis by 1H nuclear magnetic resonance (NMR) spectroscopy, and the subsequent spectral preprocessing required for an NMR-based metabolomics experiment. First, the three critical steps in the preparation of tissue extracts for NMR analysis are described, including both a perchloric acid protocol for the extraction of polar metabolites, and a methanol:chloroform protocol for extraction of polar and lipophilic metabolites. Then a series of NMR experiments are described including a standard one-dimensional (1D) 1H NMR study, a 1D 1H Carr-Purcell-Meiboom-Gill spin-echo experiment, and a two-dimensional 1H-1H J-resolved NMR experiment. The advantages and limitations of each experiment for metabolomics research are discussed. Analysis of the resulting NMR datasets is typically conducted in two phases comprising "low level" spectral preprocessing and "high level" multivariate analysis. NMR spectral preprocessing is a critical step that converts raw NMR spectra into an appropriate data format for multivariate analysis. A detailed protocol for preprocessing NMR data, using ProMetab software, is presented. Because a plethora of algorithms exist for multivariate analyses, which can be used to construct classification models or for biomarker discovery, this is beyond the scope of the current chapter.

  4. Nuclear Magnetic Resonance structural studies of peptides and proteins from the vaso-regulatory System

    International Nuclear Information System (INIS)

    Sizun, Philippe

    1991-01-01

    The aim of the present work is to show how Nuclear Magnetic Resonance (NMR) allows to determine the 3D structure of peptides and proteins in solution. A comparative study of peptides involved in the vaso-regulatory System (form small hormonal peptide to the 65 amido-acid protein hirudin) has allowed to design most efficient NMR 1D and 2D strategies. It rapidly appeared that the size of the peptide plays a key role in the structuration of the molecule, smallest peptides being weakly structured owing to the lack of cooperative effects. As the molecular size increases or if conformational locks are present (disulfide bridges) the probability of stable secondary structure increases. For the protein hirudin, a combination of ail available NMR parameters deduced form dedicated experiments (chemical shifts, coupling constants, overhauser effects, accessibility of amide protons) and molecular modelling under constraints allows a clear 3D structure to be proposed for this protein in solution. Finally, a comparative study of the experimental structures and of those deduced form prediction rules has shed light on the concept of structural predisposition, the latter being of high value for a better understanding of structure-activity relationships. (author) [fr

  5. Phosphorus-31 NMR (nuclear magnetic resonance) analysis of gold plating baths

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.E.

    1990-01-01

    This report describes the nuclear magnetic resonance (NMR) analysis of the gold plating baths in the Micro-Miniature Electronic Assembly department of Allied-Signal Inc., Kansas City Division (KCD). The baths were analyzed for phosphorylated components. In freshly prepared gold plating baths, a 50-percent aqueous solution of aminotrimethylphosphonate (ATMP) is the principal compound observed. As the bath is used in production, the ATMP breaks down and new materials (phosphate, ADMP, and AMMP) are identified. The NMR method was used to monitor the concentrations of the ATMP and breakdown products for a nine-month period. The 225-liter bath had plated approximately 100 square feet of gold during the nine-month period. These results can be used to predict the performance of baths as they are used in production. The accuracy of the analysis is 96 percent for ATMP and 92 percent for phosphate. The precision (relative standard deviation) is 5.2 percent for ATMP and 4.5 percent for phosphate. 1 ref., 5 figs., 2 tabs.

  6. 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.

  7. First experimental demonstration of an exact quantum search algorithm in nuclear magnetic resonance system

    Science.gov (United States)

    Liu, Yang; Zhang, FeiHao

    2015-07-01

    The success probability of searching an objective item from an unsorted database using standard Grover's algorithm is usually not exactly 1. It is exactly 1 only when it is used to find the target state from a database with four items. Exact search is always important in theoretical and practical applications. The failure rate of Grover's algorithm becomes big when the database is small, and this hinders the use of the commonly used divide-and-verify strategy. Even for large database, the failure rate becomes considerably large when there are many marked items. This has put a serious limitation on the usability of the Grover's algorithm. An important improved version of the Grover's algorithm, also known as the improved Grover algorithm, solves this problem. The improved Grover algorithm searches arbitrary number of target states from an unsorted database with full success rate. Here, we give the first experimental realization of the improved Grover algorithm, which finds a marked state with certainty, in a nuclear magnetic resonance system. The optimal control theory is used to obtain an optimized control sequence. The experimental results agree well with the theoretical predictions.

  8. Recent developments in solution nuclear magnetic resonance (NMR)-based molecular biology.

    Science.gov (United States)

    Ziarek, Joshua J; Baptista, Diego; Wagner, Gerhard

    2018-01-01

    Visualizing post-translational modifications, conformations, and interaction surfaces of protein structures at atomic resolution underpins the development of novel therapeutics to combat disease. As computational resources expand, in silico calculations coupled with experimentally derived structures and functional assays have led to an explosion in structure-based drug design (SBDD) with several compounds in clinical trials. It is increasingly clear that "hidden" transition-state structures along activation trajectories can be harnessed to develop novel classes of allosteric inhibitors. The goal of this mini-review is to empower the clinical researcher with a general knowledge of the strengths and weaknesses of nuclear magnetic resonance (NMR) spectroscopy in molecular medicine. Although NMR can determine protein structures at atomic resolution, its unrivaled strength lies in sensing subtle changes in a nuclei's chemical environment as a result of intrinsic conformational dynamics, solution conditions, and binding interactions. These can be recorded at atomic resolution, without explicit structure determination, and then incorporated with static structures or molecular dynamics simulations to produce a complete biological picture.

  9. Detecting unfrozen sediments below thermokarst lakes with surface nuclear magnetic resonance

    Science.gov (United States)

    Parsekian, Andrew D.; Grosse, Guido; Walbrecker, Jan O.; Müller-Petke, Mike; Keating, Kristina; Liu, Lin; Jones, Benjamin M.; Knight, Rosemary

    2013-01-01

    A talik is a layer or body of unfrozen ground that occurs in permafrost due to an anomaly in thermal, hydrological, or hydrochemical conditions. Information about talik geometry is important for understanding regional surface water and groundwater interactions as well as sublacustrine methane production in thermokarst lakes. Due to the direct measurement of unfrozen water content, surface nuclear magnetic resonance (NMR) is a promising geophysical method for noninvasively estimating talik dimensions. We made surface NMR measurements on thermokarst lakes and terrestrial permafrost near Fairbanks, Alaska, and confirmed our results using limited direct measurements. At an 8 m deep lake, we observed thaw bulb at least 22 m below the surface; at a 1.4 m deep lake, we detected a talik extending between 5 and 6 m below the surface. Our study demonstrates the value that surface NMR may have in the cryosphere for studies of thermokarst lake hydrology and their related role in the carbon cycle.

  10. Rapid quantitation of lipid in microalgae by time-domain nuclear magnetic resonance.

    Science.gov (United States)

    Gao, Chunfang; Xiong, Wei; Zhang, Yiliang; Yuan, Wenqiao; Wu, Qingyu

    2008-12-01

    A specific strain of Chlorella protothecoides has been studied in heterotrophic fermentation for increasing cell growth rate and lipid content for biodiesel production. For optimizing the process of fermentation to reduce costs of alga-based biodiesel production, rapid determination of lipid content in microalgal cells is critical. Nile Red (NR) staining and time-domain nuclear magnetic resonance (TD-NMR) have been investigated to quantitate the lipid content in C. protothecoides. Both methods were found feasible and simpler than gravimetric methods that are commonly employed. The TD-NMR method showed better agreement (R(2)=0.9973) with the measured values from lipid extraction experiments than the NR staining method (R(2)=0.9067). Additionally, the smaller standard deviations of the samples (< or =0.36) analyzed by TD-NMR revealed that the method is accurate and reproducible. The application of TD-NMR for lipid quantitation in C. protothecoides opens up the possibility of determining lipid content in algal fermentation precisely and quickly.

  11. Boundary effects of molecular diffusion in nanoporous materials: A pulsed field gradient nuclear magnetic resonance study

    Science.gov (United States)

    Geier, Oliver; Snurr, Randall Q.; Stallmach, Frank; Kärger, Jörg

    2004-01-01

    The boundary conditions of intraparticle diffusion in nanoporous materials may be chosen to approach the limiting cases of either absorbing or reflecting boundaries, depending on the host-guest system under study and the temperature of measurement. Pulsed field gradient nuclear magnetic resonance is applied to monitor molecular diffusion of n-hexane and of an n-hexane-tetrafluoromethane mixture adsorbed in zeolite crystallites of type NaX under either of these limiting conditions. Taking advantage of the thus-established peculiarities of mass transfer at the interface between the zeolite bulk phase and the surrounding atmosphere, three independent routes for probing the crystal size are compared. These techniques are based on (i) the measurement of the effective diffusivity under complete confinement, (ii) the application of the so-called NMR tracer desorption technique, and (iii) an analysis of the time dependence of the effective diffusivity in the short-time limit where, by an appropriate variation of the adsorbate and the measuring conditions, the limiting cases of reflecting and adsorbing boundaries could be considered. All these techniques are found to yield coinciding results, which are in excellent agreement with the crystal sizes determined by microscopy.

  12. Metabolomics with Nuclear Magnetic Resonance Spectroscopy in a Drosophila melanogaster Model of Surviving Sepsis

    Science.gov (United States)

    Bakalov, Veli; Amathieu, Roland; Triba, Mohamed N.; Clément, Marie-Jeanne; Reyes Uribe, Laura; Le Moyec, Laurence; Kaynar, Ata Murat

    2016-01-01

    Patients surviving sepsis demonstrate sustained inflammation, which has been associated with long-term complications. One of the main mechanisms behind sustained inflammation is a metabolic switch in parenchymal and immune cells, thus understanding metabolic alterations after sepsis may provide important insights to the pathophysiology of sepsis recovery. In this study, we explored metabolomics in a novel Drosophila melanogaster model of surviving sepsis using Nuclear Magnetic Resonance (NMR), to determine metabolite profiles. We used a model of percutaneous infection in Drosophila melanogaster to mimic sepsis. We had three experimental groups: sepsis survivors (infected with Staphylococcus aureus and treated with oral linezolid), sham (pricked with an aseptic needle), and unmanipulated (positive control). We performed metabolic measurements seven days after sepsis. We then implemented metabolites detected in NMR spectra into the MetExplore web server in order to identify the metabolic pathway alterations in sepsis surviving Drosophila. Our NMR metabolomic approach in a Drosophila model of recovery from sepsis clearly distinguished between all three groups and showed two different metabolomic signatures of inflammation. Sham flies had decreased levels of maltose, alanine, and glutamine, while their level of choline was increased. Sepsis survivors had a metabolic signature characterized by decreased glucose, maltose, tyrosine, beta-alanine, acetate, glutamine, and succinate. PMID:28009836

  13. Structure and aqueous reactivity of silicate glasses high-resolution nuclear magnetic resonance contribution

    International Nuclear Information System (INIS)

    Angeli, F.

    2000-01-01

    This research aims at getting a better understanding of the relations which may exist between the chemical composition of the oxide silicate glasses, the structure and the aqueous reactivity. We study the cations present in most glasses, more particularly the radioactive waste glasses, and those which are more liable to bring information both about structure and reactivity. Among the experimental methods used, the nuclear magnetic resonance of multi-quantum magic-angle spinning (NMR MQ-MAS) has been carried out for the structural characterization of the pristine and altered glasses. In the first part, we discuss the possibility of deducting a type of information from a quantitative approach of the 23 Na, 27 Al and 17 O NMR MQ-MAS. In the second part, we apply this method to glasses containing between two and six oxides. The vitreous compositions studied permit to focus our attention on the influence of sodium, aluminum and calcium on their local structural environment. We point out an evolution of the distributions of bond distances and angles in relation to the glass chemical composition. We show the strong potentiality of the 17 O used to probe the pristine and altered glasses. The influence of the different cations studied on the rate of glass dissolution is debated from the alterations made on short periods. On the basis of all these data, we discuss the importance of the structural effect which may influence the kinetic phenomena of alteration. (author)

  14. A sex-specific metabolite identified in a marine invertebrate utilizing phosphorus-31 nuclear magnetic resonance.

    Directory of Open Access Journals (Sweden)

    Robert A Kleps

    Full Text Available Hormone level differences are generally accepted as the primary cause for sexual dimorphism in animal and human development. Levels of low molecular weight metabolites also differ between men and women in circulating amino acids, lipids and carbohydrates and within brain tissue. While investigating the metabolism of blue crab tissues using Phosphorus-31 Nuclear Magnetic Resonance, we discovered that only the male blue crab (Callinectes sapidus contained a phosphorus compound with a chemical shift well separated from the expected phosphate compounds. Spectra obtained from male gills were readily differentiated from female gill spectra. Analysis from six years of data from male and female crabs documented that the sex-specificity of this metabolite was normal for this species. Microscopic analysis of male and female gills found no differences in their gill anatomy or the presence of parasites or bacteria that might produce this phosphorus compound. Analysis of a rare gynandromorph blue crab (laterally, half male and half female proved that this sex-specificity was an intrinsic biochemical process and was not caused by any variations in the diet or habitat of male versus female crabs. The existence of a sex-specific metabolite is a previously unrecognized, but potentially significant biochemical phenomenon. An entire enzyme system has been synthesized and activated only in one sex. Unless blue crabs are a unique species, sex-specific metabolites are likely to be present in other animals. Would the presence or absence of a sex-specific metabolite affect an animal's development, anatomy and biochemistry?

  15. Composition and structure of natural organic matter through advanced nuclear magnetic resonance techniques

    Directory of Open Access Journals (Sweden)

    Dainan Zhang

    2017-02-01

    Full Text Available Abstract Natural organic matter (NOM plays important roles in biological, chemical, and physical processes within the terrestrial and aquatic ecosystem. Despite its importance, a clear and exhaustive knowledge on NOM chemistry still lacks. Aiming to prove that advanced solid-state 13C nuclear magnetic resonance (NMR techniques may contribute to fill such a gap, in this paper we reported relevant examples of its applicability to NOM components, such as biomass, deposition material, sediments, and kerogen samples. It is found that nonhydrolyzable organic carbons (NHC, chars, and polymethylene carbons are important in the investigated samples. The structure of each of the NHC fractions is similar to that of kerogens, highlighting the importance of selective preservation of NOM to the kerogen origin in the investigated aquatic ecosystems. Moreover, during the artificial maturation experiments of kerogen, the chemical and structural characteristics such as protonated aromatic, nonprotonated carbons, and aromatic cluster size play important roles in the origin and variation of nanoporosity during kerogen maturation. Graphical abstract NMR parameters of thermally stimulated kerogens

  16. New insights into pre-lithiation kinetics of graphite anodes via nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Holtstiege, Florian; Schmuch, Richard; Winter, Martin; Brunklaus, Gunther; Placke, Tobias

    2018-02-01

    Pre-lithiation of anode materials can be an effective method to compensate active lithium loss which mainly occurs in the first few cycles of a lithium ion battery (LIB), due to electrolyte decomposition and solid electrolyte interphase (SEI) formation at the surface of the anode. There are many different pre-lithiation methods, whereas pre-lithiation using metallic lithium constitutes the most convenient and widely utilized lab procedure in literature. In this work, for the first time, solid state nuclear magnetic resonance spectroscopy (NMR) is applied to monitor the reaction kinetics of the pre-lithiation process of graphite with lithium. Based on static 7Li NMR, we can directly observe both the dissolution of lithium metal and parallel formation of LiCx species in the obtained NMR spectra with time. It is also shown that the degree of pre-lithiation as well as distribution of lithium metal on the electrode surface have a strong impact on the reaction kinetics of the pre-lithiation process and on the remaining amount of lithium metal. Overall, our findings are highly important for further optimization of pre-lithiation methods for LIB anode materials, both in terms of optimized pre-lithiation time and appropriate amounts of lithium metal.

  17. Properties of Cs-intercalated single wall carbon nanotubes investigated by 133Cs Nuclear Magnetic resonance

    KAUST Repository

    Schmid, Marc R.

    2012-11-01

    In the present study, we investigated Cs-intercalated single wall carbon nanotubes (SWCNTs) using 133Cs Nuclear Magnetic resonance. We show that there are two types of Cs cations depending on the insertion level. Indeed, at low concentrations, Static spectra analysis shows that the Cs (α)+ species are fully ionized, i.e. α equal ca.1, while at higher concentrations a second paramagnetically shifted line appears, indicating the formation of Cs (β)+ ions with β < α ∼ +1. At low concentrations and low temperatures the Cs (α)+ ions exhibit a weak hyperfine coupling to the SWCNT conduction electrons, whereas, at higher temperatures, a thermally activated slow-motion diffusion process of the Cs (α)+ ions occurs along the interstitial channels present within the carbon nanotube bundles. At high concentrations, the Cs (β)+ ions seem to occupy well defined positions relative to the carbon lattice. As a matter of fact, the Korringa relaxation behavior suggests a strong hyperfine coupling between Cs nuclei and conduction electrons in the carbon nanotubes and a partial charge transfer, which suggest a plausible Cs(6s)-C(2p) hybridization. © 2012 Elsevier Ltd. All rights reserved.

  18. Novel 1H low field nuclear magnetic resonance applications for the field of biodiesel

    Science.gov (United States)

    2013-01-01

    Background Biodiesel production has increased dramatically over the last decade, raising the need for new rapid and non-destructive analytical tools and technologies. 1H Low Field Nuclear Magnetic Resonance (LF-NMR) applications, which offer great potential to the field of biodiesel, have been developed by the Phyto Lipid Biotechnology Lab research team in the last few years. Results Supervised and un-supervised chemometric tools are suggested for screening new alternative biodiesel feedstocks according to oil content and viscosity. The tools allowed assignment into viscosity groups of biodiesel-petrodiesel samples whose viscosity is unknown, and uncovered biodiesel samples that have residues of unreacted acylglycerol and/or methanol, and poorly separated and cleaned glycerol and water. In the case of composite materials, relaxation time distribution, and cross-correlation methods were successfully applied to differentiate components. Continuous distributed methods were also applied to calculate the yield of the transesterification reaction, and thus monitor the progress of the common and in-situ transesterification reactions, offering a tool for optimization of reaction parameters. Conclusions Comprehensive applied tools are detailed for the characterization of new alternative biodiesel resources in their whole conformation, monitoring of the biodiesel transesterification reaction, and quality evaluation of the final product, using a non-invasive and non-destructive technology that is new to the biodiesel research area. A new integrated computational-experimental approach for analysis of 1H LF-NMR relaxometry data is also presented, suggesting improved solution stability and peak resolution. PMID:23590829

  19. Characterization and Thermal Rearrangement Investigation of 1,4-Polybutadiene by Nuclear Magnetic Resonance Spectroscopy

    Directory of Open Access Journals (Sweden)

    F. Ziaee

    2009-12-01

    Full Text Available Microstructural investigation of low molecular weight 1,4-polybutadiene (1,4-PBD was studied by 1H and 13C nuclear magnetic resonance spectroscopy (NMR. The isomer contents of 1,4-cis, 1,4-trans and 1,2- vinyl in polybutadiene microstructure were determined. The number average molecular weight for low molecular weight polybutadiene was measured by NMR techniques and comparison was made with gel permeation chromatography (GPC results. Due to the presence of methyl end group and considering the repeating units in 1,4-PBD microstructure, the number average molecular weight was calculated by NMR techniques. This study was accomplished by obtaining cis-trans isomerization in non-pyrolytic anaerobic conditions at 200 to 250oC. The results showed that increase in heat treatment time increased the trans isomer and decreased the cis isomer contents respectively. The presence of 1,2-vinyl isomers increased the average molecular weights by heat treatment time at 250oC and did not lead to any chain scission in 1,4-PBD.

  20. The state of benzene in TIP slurry using nuclear magnetic resonance measurements

    International Nuclear Information System (INIS)

    Dworjanyn, L.O.

    1997-01-01

    Nuclear Magnetic Resonance (NMR) measurements on In-Tank Precipitation (ITP) simulated potassium tetraphenylborate (KTPB) slurries at Pacific Northwest National Laboratory have been completed. Most measurements were made on 4 wt percent KTPB slurry in 4 to 5 molar sodium salt solution. Liquid benzene was added volumetrically to the slurry in 25-mL vials and agitated to create a suspension. Earlier tests using dyed benzene showed that benzene remains suspended permanently in the slurry and the only visible change is overall slurry settling. Gentle vial agitation restores the original suspension state. To simulate in-situ uniformly dispersed benzene, benzene/KTPB samples were homogenized using a high speed rotor/stator biological homogenizer. Photomicrographs using homogenized samples containing dyed benzene showed no residual benzene droplets and fairly uniform coloration of the KTPB solids structure. All benzene concentration estimates are based on benzene addition since there is no available analytical method for benzene in slurry. Benzene losses could be significant, particularly at low concentrations and during homogenization

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

    International Nuclear Information System (INIS)

    Wang, Z.; Bogdan, A.R.; Zimmermann, R.A.; Gusnard, D.A.; Leigh, J.S.; Ohene-Frempong, K.

    1992-01-01

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

  2. Recent Advances in Characterization of Lignin Polymer by Solution-State Nuclear Magnetic Resonance (NMR Methodology

    Directory of Open Access Journals (Sweden)

    Run-Cang Sun

    2013-01-01

    Full Text Available The demand for efficient utilization of biomass induces a detailed analysis of the fundamental chemical structures of biomass, especially the complex structures of lignin polymers, which have long been recognized for their negative impact on biorefinery. Traditionally, it has been attempted to reveal the complicated and heterogeneous structure of lignin by a series of chemical analyses, such as thioacidolysis (TA, nitrobenzene oxidation (NBO, and derivatization followed by reductive cleavage (DFRC. Recent advances in nuclear magnetic resonance (NMR technology undoubtedly have made solution-state NMR become the most widely used technique in structural characterization of lignin due to its versatility in illustrating structural features and structural transformations of lignin polymers. As one of the most promising diagnostic tools, NMR provides unambiguous evidence for specific structures as well as quantitative structural information. The recent advances in two-dimensional solution-state NMR techniques for structural analysis of lignin in isolated and whole cell wall states (in situ, as well as their applications are reviewed.

  3. Echo planar imaging in paediatrics: real-time-nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Rzedzian, R.; Doyle, M.; Mansfield, P.; Chapman, B.; Guilfoyle, D.; Coupland, R.E.; Small, P. (Universite of Nottingham (UK)); Chrispin, A. (City Hospital, Nottingham (UK))

    In 1982 Ordidge, Mansfield, Doyle and Coupland reported the first EPI movie images which were obtained using rabbits. From this study the potential use of EPI in human beings became clear. EPI is a distinctive usage of Nuclear Magnetic Resonance. Transaxial images are acquired in a very short period of time and so they are not blurred. These images accumulate in rapid sequence at each level of the anatomical transection. Each image may be linked to the events of the cardiac cycle. Construction of images in the sagittal and coronal planes may be carried out. This technique is particularly appropriate in the examination of the intrathoracic content of the infant or child. The rapidly contracting heart and the events associated with respiratory movement do not constitute a handicap to imaging the heart and great vessels and the lungs. It is this aspect of EPI which will be presented. The chambers of the heart and the great vessels may be delineated by EPI, yielding both anatomical and functional information. The pulmonary vessels may be seen in the central parts of the lungs. Alterations in proton density in the lung fields may be investigated by EPI. EPI is particularly appropriate for the examination of children for it is rapidly carried out and devoid of known hazard. Access to the patient is excellent throughout the examination.

  4. Echo planar imaging in paediatrics: real-time-nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Rzedzian, R.; Doyle, M.; Mansfield, P.; Chapman, B.; Guilfoyle, D.; Coupland, R.E.; Small, P.; Chrispin, A.

    1984-01-01

    In 1982 Ordidge, Mansfield, Doyle and Coupland reported the first EPI movie images which were obtained using rabbits. From this study the potential use of EPI in human being became clear. EPI is a distinctive usage of Nuclear Magnetic Resonance. Transaxial images are acquired in a very short period of time and so they are not blurred. These images accumulate in rapid sequence at each level of the anatomical transection. Each image may be linked to the events of the cardiac cycle. Constuction of images in the sagittal and coronal planes may be carried out. This technique is particularly appropriate in the examination of the intrathoracic content of the infant or child. The rapidly contracting heart and the events associated with respiratory movement do not constitute a handicap to imaging the heart and great vessels and the lungs. It is this aspect of EPI which will be presented. The chambers of the heart and the great vessels may be delineated by EPI, yielding both anatomical and functional information. The pulmonary vessels may be seen in the central parts of the lungs. Alterations in proton density in the lung fields may be investigated by EPI. EPI is particularly appropriate for the examination of children for it is rapidly carried out and devoid of known hazard. Access to the patient is excellent throughout the examination [fr

  5. Gated in vivo examination of cardiac metabolites with 31P nuclear magnetic resonance

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  6. The state of benzene in TIP slurry using nuclear magnetic resonance measurements

    Energy Technology Data Exchange (ETDEWEB)

    Dworjanyn, L.O.

    1997-11-14

    Nuclear Magnetic Resonance (NMR) measurements on In-Tank Precipitation (ITP) simulated potassium tetraphenylborate (KTPB) slurries at Pacific Northwest National Laboratory have been completed. Most measurements were made on 4 wt percent KTPB slurry in 4 to 5 molar sodium salt solution. Liquid benzene was added volumetrically to the slurry in 25-mL vials and agitated to create a suspension. Earlier tests using dyed benzene showed that benzene remains suspended permanently in the slurry and the only visible change is overall slurry settling. Gentle vial agitation restores the original suspension state. To simulate in-situ uniformly dispersed benzene, benzene/KTPB samples were homogenized using a high speed rotor/stator biological homogenizer. Photomicrographs using homogenized samples containing dyed benzene showed no residual benzene droplets and fairly uniform coloration of the KTPB solids structure. All benzene concentration estimates are based on benzene addition since there is no available analytical method for benzene in slurry. Benzene losses could be significant, particularly at low concentrations and during homogenization.

  7. 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.

  8. Magnetic moment of Ag-104(m) and the hyperfine magnetic field of Ag in Fe using nuclear magnetic resonance on oriented nuclei

    CERN Document Server

    Golovko, V.V.; Phalet, T.; Delaure, B.; Beck, M.; Kozlov, V.Yu.; Coeck, S.; Wauters, F.; Herzog, P.; Tramm, Ch.; Zakoucky, D.; Venos, D.; Srnka, D.; Honusek, M.; Koster, U.; Severijns, N.

    2010-01-01

    Nuclear magnetic resonance (NMR/ON) measurements with beta- and gamma-ray detection have been performed on oriented Ag-104(g,m) nuclei with the NICOLE He-3-He-4 dilution refrigerator setup at ISOLDE/CERN. For Ag-104(g) (I-pi = 5(+)) the gamma-NMR/ON resonance signal was found at nu = 266.70(5) MHz. Combining this result with the known magnetic moment for this isotope, the magnetic hyperfine field of Ag impurities in an Fe host at low temperature (< 1 K) is found to be vertical bar B-hf(AgFe)vertical bar = 44.709(35) T. A detailed analysis of other relevant data available in the literature yields three more values for this hyperfine field. Averaging all four values yields a new and precise value for the hyperfine field of Ag in Fe; that is, vertical bar B-hf(AgFe)vertical bar = 44.692(30) T. For Ag-104(m) (I-pi = 2(+)), the anisotropy of the beta particles provided the NMR/ON resonance signal at nu = 627.7(4) MHz. Using the new value for the hyperfine field of Ag in Fe, this frequency corresponds to the mag...

  9. High resolution nuclear magnetic resonance: From chemical structure to food authenticity

    Directory of Open Access Journals (Sweden)

    Segre, Annalaura

    2002-03-01

    Full Text Available 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.La resonancia magnética nuclear (RMN es una técnica poderosa capaz de generar una contribución relevante en análisis de alimentos. En esta revisión, se describen algunos aspectos prácticos de la técnica (preparación de la muestra, tiempo de adquisición, retraso en la relajación, etc junto con algunos métodos espectrales de asignación del espectro (técnicas selectivas 2D y 1D. También se describen algunos ejemplos del análisis cuantitativo. En particular, se discuten los resultados relativos al estudio RMN de los aceites de oliva, entre estos: la comparación entre los análisis convencionales y los análisis por RMN en la caracterización del aceite de oliva; la determinación de componentes menores del aceite de oliva, como el escualeno, cicloartenol y clorofilas; el panel sensorial y su relación con los datos de RMN; y la caracterización geográfica de los aceites de oliva.

  10. Metabolic profiling of serum samples by 1H nuclear magnetic resonance spectroscopy as a potential diagnostic approach for septic shock.

    Science.gov (United States)

    Mickiewicz, Beata; Duggan, Gavin E; Winston, Brent W; Doig, Christopher; Kubes, Paul; Vogel, Hans J

    2014-05-01

    To determine whether a nuclear magnetic resonance-based metabolomics approach can be useful for the early diagnosis and prognosis of septic shock in ICUs. Laboratory-based study. University research laboratory. Serum samples from septic shock patients and ICU controls (ICU patients with systemic inflammatory response syndrome but not suspected of having an infection) were collected within 24 hours of admittance to the ICU. None. H nuclear magnetic resonance spectra of septic shock and ICU control samples were analyzed and quantified using a targeted profiling approach. By applying multivariate statistical analysis (e.g., orthogonal partial least squares discriminant analysis), we were able to distinguish the patient groups and detect specific metabolic patterns. Some of the metabolites were found to have a significant impact on the separation between septic shock and control samples. These metabolites could be interpreted in terms of a biological human response to septic shock and they might serve as a biomarker pattern for septic shock in ICUs. Additionally, nuclear magnetic resonance-based metabolomics was evaluated in order to detect metabolic variation between septic shock survivors and nonsurvivors and to predict patient outcome. The area under the receiver operating characteristic curve indicated an excellent predictive ability for the constructed orthogonal partial least squares discriminant analysis models (septic shock vs ICU controls: area under the receiver operating characteristic curve = 0.98; nonsurvivors vs survivors: area under the receiver operating characteristic curve = 1). Our results indicate that nuclear magnetic resonance-based metabolic profiling could be used for diagnosis and mortality prediction of septic shock in the ICU.

  11. Nontargeted nuclear magnetic resonance (NMR) analysis to detect hazardous substances including methanol in unrecorded alcohol from Novosibirsk, Russia

    OpenAIRE

    Hausler, Thomas; Okaru,  Alex O.; Neufeld, Maria; Rehm, Jürgen; Kuballa, Thomas; Luy, Burkhard; Lachenmeier, Dirk W.

    2016-01-01

    Nuclear magnetic resonance (NMR) spectroscopy was applied to the analysis of alcoholic products in the context of health and safety control. A total of 86 samples of unrecorded alcohol were collected in Novosibirsk and nearby cities in Russia. Sampling was based on interviews with alcohol dependent patients, and unrecorded alcohol thus defined included illegally or informally produced alcoholic products (e.g., counterfeit or home-made alcoholic beverages) or surrogate alcohol in the form of c...

  12. Solution structure of human insulin-like growth factor 1: A nuclear magnetic resonance and restrained molecular dynamics study

    International Nuclear Information System (INIS)

    Cooke, R.M.; Harvey, T.S.; Campbell, I.D.

    1991-01-01

    The solution structure of human insulin-like growth factor 1 has been investigated with a combination of nuclear magnetic resonance and restrained molecular dynamics methods. The results show that the solution structure is similar to that of insulin, but minor differences exist. The regions homologous to insulin are well-defined, while the remainder of the molecular exhibits greater disorder. The resultant structures have been used to visualize the sites for interaction with a number of physiologically important protein

  13. 1H nuclear magnetic resonance studies of sarcoplasmic oxygenation in the red cell-perfused rat heart

    OpenAIRE

    Jelicks, L.A.; Wittenberg, B.A.

    1995-01-01

    The proximal histidine N delta H proton of deoxymyoglobin experiences a large hyperfine shift resulting in its 1H nuclear magnetic resonance (NMR) signal appearing at approximately 76 ppm (at 35 degrees C), downfield of the diamagnetic spectral region. 1H NMR of this proton is used to monitor sarcoplasmic oxygen pressure in isolated perfused rat heart. This method monitors intracellular oxygenation in the whole heart and does not reflect oxygenation in a limited region. The deoxymyoglobin res...

  14. Technical Note: Compact three-tesla magnetic resonance imager with high-performance gradients passes ACR image quality and acoustic noise tests.

    Science.gov (United States)

    Weavers, Paul T; Shu, Yunhong; Tao, Shengzhen; Huston, John; Lee, Seung-Kyun; Graziani, Dominic; Mathieu, Jean-Baptiste; Trzasko, Joshua D; Foo, Thomas K-F; Bernstein, Matt A

    2016-03-01

    A compact, three-tesla magnetic resonance imaging (MRI) system has been developed. It features a 37 cm patient aperture, allowing the use of commercial receiver coils. Its design allows simultaneously for gradient amplitudes of 85 millitesla per meter (mT/m) sustained and 700 tesla per meter per second (T/m/s) slew rates. The size of the gradient system allows for these simultaneous performance targets to be achieved with little or no peripheral nerve stimulation, but also raises a concern about the geometric distortion as much of the imaging will be done near the system's maximum 26 cm field-of-view. Additionally, the fast switching capability raises acoustic noise concerns. This work evaluates the system for both the American College of Radiology's (ACR) MRI image quality protocol and the Food and Drug Administration's (FDA) nonsignificant risk (NSR) acoustic noise limits for MR. Passing these two tests is critical for clinical acceptance. In this work, the gradient system was operated at the maximum amplitude and slew rate of 80 mT/m and 500 T/m/s, respectively. The geometric distortion correction was accomplished by iteratively determining up to the tenth order spherical harmonic coefficients using a fiducial phantom and position-tracking software, with seventh order correction utilized in the ACR test. Acoustic noise was measured with several standard clinical pulse sequences. The system passes all the ACR image quality tests. The acoustic noise as measured when the gradient coil was inserted into a whole-body MRI system conforms to the FDA NSR limits. The compact system simultaneously allows for high gradient amplitude and high slew rate. Geometric distortion concerns have been mitigated by extending the spherical harmonic correction to higher orders. Acoustic noise is within the FDA limits.

  15. 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)

  16. A solid state nuclear magnetic resonance study of industrial inorganic pigments

    International Nuclear Information System (INIS)

    Dajda, Nick

    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 4 ) pigments were examined using 19 F, 23 Na, 29 Si, 51 V and 91 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 indicated that the V 4+ colouring ion probably substitutes into both the tetrahedral SiO 4 site, and at the dodecahedral ZrO 8 site. This is of current interest, and many other spectroscopic and computational experiments have also been performed to elucidate which of the two sites V 4+ is located at. A 17 O-enriched zircon sample was also synthesised through a sol-gel route, and the local environment at the oxygen sites was followed through zircon formation from the TEOS and Zr-isopropoxide precursors. A multinuclear approach looking at the 11 B, 23 Na, 27 Al and 29 Si isotopes within silver containing glasses was able to provide information about the coordination of the isotopes within the glasses. 109 Ag NMR was evaluated as an experimental technique for examining silver containing compounds. 119 Sn NMR was used to quantify the amount of Sn(ll) and Sn(IV) in orange coloured SnO-ZnO-TiO 2 (TZT) produced pigments, and the colour of the sample was found to correlate with the width of the Sn(IV) peak. The level of

  17. COHERENT RESONANT SCATTERING OF NUCLEAR RADIATION IN A PARAMAGNETIC ABSORBER PLACED IN A MAGNETIC-FIELD

    NARCIS (Netherlands)

    TENBROEK, F

    1993-01-01

    When a thick Mossbauer absorber of (paramagnetic) ferric alum enriched in Fe-57 is placed in a longitudinal magnetic field of 270 G, a reduction of the intensity of backscattered resonant radiation from a 57CORh is observed. This is interpreted as caused by an increase of the degree of coherence of

  18. {sup 29}Si nuclear magnetic resonance study of URu{sub 2}Si{sub 2} under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Shirer, K.R., E-mail: krshirer@ucdavis.edu [Department of Physics, University of California, Davis, CA 95616 (United States); Dioguardi, A.P.; Bush, B.T.; Crocker, J.; Lin, C.H.; Klavins, P. [Department of Physics, University of California, Davis, CA 95616 (United States); Cooley, J.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Maple, M.B. [Department of Physics and Institute for Pure and Applied Physical Sciences, University of California, San Diego, La Jolla, CA 92093-0319 (United States); Chang, K.B.; Poeppelmeier, K.R. [Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (United States); Curro, N.J. [Department of Physics, University of California, Davis, CA 95616 (United States)

    2016-01-15

    We report {sup 29}Si nuclear magnetic resonance measurements of single crystals and aligned powders of URu{sub 2}Si{sub 2} under pressure in the hidden order and paramagnetic phases. We find that the Knight shift decreases with applied pressure, consistent with previous measurements of the static magnetic susceptibility. Previous measurements of the spin lattice relaxation time revealed a partial suppression of the density of states below 30 K. This suppression persists under pressure, and the onset temperature is mildly enhanced.

  19. Magnetic resonance imaging the basics

    CERN Document Server

    Constantinides, Christakis

    2014-01-01

    Magnetic resonance imaging (MRI) is a rapidly developing field in basic applied science and clinical practice. Research efforts in this area have already been recognized with five Nobel prizes awarded to seven Nobel laureates in the past 70 years. Based on courses taught at The Johns Hopkins University, Magnetic Resonance Imaging: The Basics provides a solid introduction to this powerful technology. The book begins with a general description of the phenomenon of magnetic resonance and a brief summary of Fourier transformations in two dimensions. It examines the fundamental principles of physics for nuclear magnetic resonance (NMR) signal formation and image construction and provides a detailed explanation of the mathematical formulation of MRI. Numerous image quantitative indices are discussed, including (among others) signal, noise, signal-to-noise, contrast, and resolution. The second part of the book examines the hardware and electronics of an MRI scanner and the typical measurements and simulations of m...

  20. Acoustic resonance for nonmetallic mine detection

    Energy Technology Data Exchange (ETDEWEB)

    Kercel, S.W.

    1998-04-01

    The feasibility of acoustic resonance for detection of plastic mines was investigated by researchers at the Oak Ridge National Laboratory`s Instrumentation and Controls Division under an internally funded program. The data reported in this paper suggest that acoustic resonance is not a practical method for mine detection. Representative small plastic anti-personnel mines were tested, and were found to not exhibit detectable acoustic resonances. Also, non-metal objects known to have strong acoustic resonances were tested with a variety of excitation techniques, and no practical non-contact method of exciting a consistently detectable resonance in a buried object was discovered. Some of the experimental data developed in this work may be useful to other researchers seeking a method to detect buried plastic mines. A number of excitation methods and their pitfalls are discussed. Excitation methods that were investigated include swept acoustic, chopped acoustic, wavelet acoustic, and mechanical shaking. Under very contrived conditions, a weak response that could be attributed to acoustic resonance was observed, but it does not appear to be practical as a mine detection feature. Transfer properties of soil were investigated. Impulse responses of several representative plastic mines were investigated. Acoustic leakage coupling, and its implications as a disruptive mechanism were investigated.

  1. Advances in magnetic resonance 5

    CERN Document Server

    Waugh, John S

    2013-01-01

    Advances in Magnetic Resonance, Volume 5 deals with the interpretation of ESR spectra and provides descriptions of experimental apparatus. This book discusses the halogen hyperfine interactions; organic radicals in single crystals; pulsed-Fourier-transform nuclear magnetic resonance spectrometer; and inhomogenizer and decoupler. The spectrometers for multiple-pulse NMR; weak collision theory of relaxation in the rotating frame; and spin Hamiltonian for the electron spin resonance of irradiated organic single crystals are also deliberated. This text likewise covers the NMR in helium three and m

  2. Nuclear magnetic resonance analysis of freeze-thaw damage in natural pumice concrete

    Directory of Open Access Journals (Sweden)

    Wang, Xiaoxiao

    2016-06-01

    Full Text Available This paper presents an analysis of the damage propagation features of the pore structure of natural pumice lightweight aggregate concrete (LWC under freeze-thaw cyclic action. After freeze-thaw cycling, we conducted nuclear magnetic resonance (NMR tests on the concrete and acquired the porosity, distribution of transverse relaxation time T2, and magnetic resonance imaging (MRI results. The results showed the following. The T2 distribution of the LWC prior to freeze-thaw cycling presented four peaks representative of a preponderance of small pores. After 50, 100, 150, and 200 freeze-thaw cycles, the total area of the T2 spectrum and the porosity increased significantly. The MRI presented the changing spatial distribution of pores within the LWC during freeze-thaw cycling. Ultrasonic testing technology was applied simultaneously to analyze the NMR results, which verified that the new NMR technology demonstrated high accuracy and practicability for research regarding freeze-thaw concrete damage.En este trabajo se analiza la propagación de los daños que se producen en la estructura porosa de hormigón aligerado a base de piedra pómez natural sometido a la acción cíclica de hielo-deshielo. Después de realizarse los ensayos de hielo-deshielo, el hormigón se analizó mediante resonancia magnética nuclear (RMN, determinándose la porosidad y la distribución del tiempo de relajación transversal, T2, y registrándose las imágenes captadas por resonancia magnética. De acuerdo con los resultados obtenidos, antes de los ciclos de hielo-deshielo la distribución de T2 del hormigón aligerado presentaba cuatro picos, indicativos de un predominio de poros pequeños. Después de que se sometiera a 50, 100, 150, y 200 ciclos, se observó un aumento importante tanto de la porosidad como de la superficie total del espectro de T2. Las imágenes captadas por resonancia magnética evidenciaron la modificación de la distribución espacial de los poros del

  3. Islets of Meningioma in an Acoustic Schwannoma in a Patient with Neurofibromatosis-2: Pathology and Magnetic Resonance Imaging Findings

    International Nuclear Information System (INIS)

    Gelal, F.; Rezanko, T.; Uyaroglu, M.A.; Tunakan, M.; Bezircioglu, H.

    2005-01-01

    Mixed tumors of the cerebellopontine angle, composed of meningioma and schwannoma components, are extremely rare; so far, only 12 cases have been reported in the literature. They are thought to be exclusively associated with neurofibromatosis-2. We present a mixed tumor of schwannoma and meningioma in a patient with neurofibromatosis-2 and discuss the pathology and magnetic resonance imaging (MRI) findings in relation to the literature. Review of the literature shows that a typical MRI pattern has not been established for mixed tumors and it seems unlikely that a meningioma component can be differentiated within a schwannoma preoperatively

  4. 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.

  5. A proton nuclear magnetic resonance-based metabonomics study of metabolic profiling in immunoglobulin a nephropathy

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Weiguo; Che, Wenti; Guimai, Zuo; Chen, Jiejing [181st Hospital Guangxi, Central Laboratory, Laboratory of Metabolic Diseases Research, Guangxi Province (China); Li, Liping [Guangxi Normal University, The Life Science College, Guangxi Province (China); Li, Wuxian [Key Laboratory of Laboratory Medical Diagnostics of Education Ministry, Chongqiong Medical University, Chongqing (China); Dai, Yong [Clinical Medical Research Center, the Second Clinical Medical College of Jinan University (Shenzhen People' s Hospital), Shenzhen, Guangdong Province (China)

    2012-07-01

    Objectives: Immunoglobulin A nephropathy is the most common cause of chronic renal failure among primary glomerulonephritis patients. The ability to diagnose immunoglobulin A nephropathy remains poor. However, renal biopsy is an inconvenient, invasive, and painful examination, and no reliable biomarkers have been developed for use in routine patient evaluations. The aims of the present study were to identify immunoglobulin A nephropathy patients, to identify useful biomarkers of immunoglobulin A nephropathy and to establish a human immunoglobulin A nephropathy metabolic profile. Methods: Serum samples were collected from immunoglobulin A nephropathy patients who were not using immunosuppressants. A pilot study was undertaken to determine disease-specific metabolite biomarker profiles in three groups: healthy controls (N = 23), low-risk patients in whom immunoglobulin A nephropathy was confirmed as grades I-II by renal biopsy (N = 23), and high-risk patients with nephropathies of grades IV-V (N = 12). Serum samples were analyzed using proton nuclear magnetic resonance spectroscopy and by applying multivariate pattern recognition analysis for disease classification. Results: Compared with the healthy controls, both the low-risk and high-risk patients had higher levels of phenylalanine, myo-inositol, lactate, L6 lipids ( CH-CH{sub 2}-CH = O), L5 lipids (-CH{sub 2}-C = O), and L3 lipids (-CH{sub 2}-CH{sub 2}-C = O) as well as lower levels of {beta}-glucose, {alpha}-glucose, valine, tyrosine, phosphocholine, lysine, isoleucine, glycerolphosphocholine, glycine, glutamine, glutamate, alanine, acetate, 3-hydroxybutyrate, and 1-methylhistidine. Conclusions: These metabolites investigated in this study may serve as potential biomarkers of immunoglobulin A nephropathy. Point scoring of pattern recognition analysis was able to distinguish immunoglobulin A nephropathy patients from healthy controls. However, there were no obvious differences between the low-risk and high

  6. Relations between radiobiological hypoxia and nuclear magnetic resonance-imaged blood microcirculation in experimental tumors

    International Nuclear Information System (INIS)

    Koike, Sachiko; Ando, Koichi; Ikehira, Hiroo.

    1993-01-01

    Characteristics of hypoxic cells subjected to radiation were investigated and compared with those of microcirculation for two murine fibrosarcomas growing in C3H mice. Small NFSa tumors, growing in air-breathing mice, developed a radioresistant tail on the survival curve. The tail was indistinguishably parallel to a survival curve for an artificially hypoxic tumor. As the NFSa tumors increased in size, the hypoxic tail moved upward with no change of Do, resulting in increase of hypoxic fraction from 3.9% to 40%. The R1137 tumors had no radioresistant tail nor hypoxic fraction regardless of tumor size. However, large-sized R1137 tumors developed a significant number of radioresistant, hypoxic cells with an intermediate Do, and were effectively sensitized by administrating misonidazole before irradiation. Thus, the NFSa tumors were fractionally hypoxic, and the large R1137 tumors had intermediate hypoxia. Measurement of tumor microcirculation by gadolinium-enhanced nuclear magnetic resonance indicated that both blood flow and blood volume decreased significantly when the NFSa tumor grew large. Similar reduction in these microcirculation parameters was also observed for the R1137 tumor. The small-sized NFSa tumor had relatively larger blood volume and faster blood flow than the small-sized R1137 tumor. When large-sized tumors were compared to each other, the NFSa again had better blood flow than the R1137. However, the blood volume in the large-sized tumors was significantly (p<0.05) smaller for the NFSa tumor than for the R1137 tumor. It was concluded that blood flow could not be a single determinant for tumor hypoxia, and the difference between fractional hypoxia and intermediate hypoxia would be reflected in the ratio of blood flow to blood volume. (author)

  7. A proton nuclear magnetic resonance-based metabonomics study of metabolic profiling in immunoglobulin a nephropathy

    International Nuclear Information System (INIS)

    Sui, Weiguo; Che, Wenti; Guimai, Zuo; Chen, Jiejing; Li, Liping; Li, Wuxian; Dai, Yong

    2012-01-01

    Objectives: Immunoglobulin A nephropathy is the most common cause of chronic renal failure among primary glomerulonephritis patients. The ability to diagnose immunoglobulin A nephropathy remains poor. However, renal biopsy is an inconvenient, invasive, and painful examination, and no reliable biomarkers have been developed for use in routine patient evaluations. The aims of the present study were to identify immunoglobulin A nephropathy patients, to identify useful biomarkers of immunoglobulin A nephropathy and to establish a human immunoglobulin A nephropathy metabolic profile. Methods: Serum samples were collected from immunoglobulin A nephropathy patients who were not using immunosuppressants. A pilot study was undertaken to determine disease-specific metabolite biomarker profiles in three groups: healthy controls (N = 23), low-risk patients in whom immunoglobulin A nephropathy was confirmed as grades I-II by renal biopsy (N = 23), and high-risk patients with nephropathies of grades IV-V (N = 12). Serum samples were analyzed using proton nuclear magnetic resonance spectroscopy and by applying multivariate pattern recognition analysis for disease classification. Results: Compared with the healthy controls, both the low-risk and high-risk patients had higher levels of phenylalanine, myo-inositol, lactate, L6 lipids ( CH-CH 2 -CH = O), L5 lipids (-CH 2 -C = O), and L3 lipids (-CH 2 -CH 2 -C = O) as well as lower levels of β-glucose, α-glucose, valine, tyrosine, phosphocholine, lysine, isoleucine, glycerolphosphocholine, glycine, glutamine, glutamate, alanine, acetate, 3-hydroxybutyrate, and 1-methylhistidine. Conclusions: These metabolites investigated in this study may serve as potential biomarkers of immunoglobulin A nephropathy. Point scoring of pattern recognition analysis was able to distinguish immunoglobulin A nephropathy patients from healthy controls. However, there were no obvious differences between the low-risk and high-risk groups in our research

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

    Energy Technology Data Exchange (ETDEWEB)

    Tunnah, Susan K

    2000-07-01

    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 accommodate the interpolation of these molecules. The spatial arrangement adopted by each of these species appeared to dictate its effect on the lipids. Doxorubicin and menadione, both known to cause oxidative stress, were added to K562 cells. Although both agents are known to act by different mechanisms, the NMR data and scanning electron microscopy suggested that both caused similar alterations in the membrane organisation and lipid fluidity. Protrusions were formed indicating areas of weakness in the membrane. Spin-echo NMR was employed to investigate the action of the thiol-containing compounds, penicillamine, captopril and N-acetylcysteine in erythrocytes under conditions of oxidative stress. Results indicate that while captopril acts as a free radical scavenger, penicillamine may act as either oxidant or reductant. N-acetylcysteine was observed to act as a reducing agent. (author)

  9. Metabolic changes associated with papillary thyroid carcinoma: A nuclear magnetic resonance-based metabolomics study.

    Science.gov (United States)

    Li, Yanyun; Chen, Minjian; Liu, Cuiping; Xia, Yankai; Xu, Bo; Hu, Yanhui; Chen, Ting; Shen, Meiping; Tang, Wei

    2018-05-01

    Papillary thyroid carcinoma (PTC) is the most common thyroid cancer. Nuclear magnetic resonance (NMR)‑based metabolomic technique is the gold standard in metabolite structural elucidation, and can provide different coverage of information compared with other metabolomic techniques. Here, we firstly conducted NMR based metabolomics study regarding detailed metabolic changes especially metabolic pathway changes related to PTC pathogenesis. 1H NMR-based metabolomic technique was adopted in conju-nction with multivariate analysis to analyze matched tumor and normal thyroid tissues obtained from 16 patients. The results were further annotated with Kyoto Encyclopedia of Genes and Genomes (KEGG), and Human Metabolome Database, and then were analyzed using modules of pathway analysis and enrichment analysis of MetaboAnalyst 3.0. Based on the analytical techniques, we established the models of principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and orthogonal partial least-squares discriminant analysis (OPLS‑DA) which could discriminate PTC from normal thyroid tissue, and found 15 robust differentiated metabolites from two OPLS-DA models. We identified 8 KEGG pathways and 3 pathways of small molecular pathway database which were significantly related to PTC by using pathway analysis and enrichment analysis, respectively, through which we identified metabolisms related to PTC including branched chain amino acid metabolism (leucine and valine), other amino acid metabolism (glycine and taurine), glycolysis (lactate), tricarboxylic acid cycle (citrate), choline metabolism (choline, ethanolamine and glycerolphosphocholine) and lipid metabolism (very-low‑density lipoprotein and low-density lipoprotein). In conclusion, the PTC was characterized with increased glycolysis and inhibited tricarboxylic acid cycle, increased oncogenic amino acids as well as abnormal choline and lipid metabolism. The findings in this study provide new

  10. Non-destructive ripeness sensing by using proton NMR [Nuclear Magnetic Resonance

    International Nuclear Information System (INIS)

    Cho, Seong In; Krutz, G.W.; Stroshine, R.L.

    1990-01-01

    More than 80 kinds of fruits and vegetables are available in the United States. But only about 6 of them have their quality standards (Dull, 1986). In the 1990 Fresh Trends survey (Zind, 1990), consumers were asked to rate 16 characteristics important to their decision to purchase fresh produce. The four top ranking factors were ripeness/freshness, taste/flavor, appearance/condition and nutritional value. Of these surveyed, 96% rated ripeness/freshness as extremely important or very important. Therefore, the development of reliable grading or sorting techniques for fresh commodities is essential. Determination of fruit quality often involves cutting and tasting. Non-destructive quality control in fruit and vegetables is a goal of growers and distributors, as well as the food processing industry. Many nondestructive techniques have been evaluated including soft x-ray, optical transmission, near infrared radiation, and machine vision. However, there are few reports of successful non-destructive measurement of sugar content directly in fruit. Higher quality fruit could be harvested and available to consumers if a nondestructive sensor that detects ripeness level directly by measuring sugar content were available. Using proton Nuclear Magnetic Resonance (NMR) principle is the possibility. A nondestructive ripeness (or sweetness) sensor for fruit quality control can be developed with the proton NMR principle (Cho, 1989). Several feasibility studies were necessary for the ripeness sensor development. Main objectives in this paper was to investigate the feasibilities (1) to detect ripeness (or sweetness level) of raw fruit tissue with an high resolution proton NMR spectroscopy (200 MHz) and (2) to measure sugar content of intact fruit with a low resolution proton NMR spectroscopy (10 MHz). 7 refs., 4 figs

  11. Porosities and permeability of Paleozoic sandstones derived from Nuclear Magnetic Resonance measurements

    Science.gov (United States)

    Jorand, Rachel; Koch, Andreas; Mohnke, Oliver; Klitzsch, Norbert; Clauser, Christoph

    2010-05-01

    A major obstacle for an increased use of geothermal energy often lies in the high success risk for the development of geothermal reservoirs due to the unknown rock properties. In general, the ranges of porosity and permeability in existing compilations of rock properties are too large to be useful to constrain properties for specific sites. Usually, conservative assumptions are made about these properties, resulting in greater drilling depth and increased exploration cost. In this study, data from direct measurements on thirty-three sandstones from different borehole locations and depths enable to derive statistical values of the desired hydraulic properties for selected sandstones in the German subsurface. We used Nuclear Magnetic Resonance (NMR) measurements to estimate the porosity and the permeability of sandstones from North Rhine-Westphalia (Germany). Besides NMR standard poro-perm-measurements were performed on the samples to obtain independent data sets for comparison. Porosity was measured by Archimedes principle and pore-size distribution by mercury injection. Also permeability was determined by gas flow measurements taking into account the Klinkenberg effect. The porosities of the studied samples vary between 0 % and 16 %. NMR yields suitable porosity results whereas the porosities obtain by T1 relaxation measurements fit better to the Archimedes porosities than the porosities obtained by T2 relaxation measurements. For porosities up to 10 %, T2 relaxation measurements overestimate the porosity. Furthermore, we calculate the effective porosity using a cutoff time of 3 ms. This effective porosity agrees much better with Archimedes porosities, particularly for the low porosity samples. The gas permeability of studied sandstones varies between 10-21 m2 and 2.10-17 m2. A large number of empirical relationships between relaxation times and gas permeability have been published. We have applied several of these relationships to select the appropriate law for

  12. Effects of CO2 injection and Kerogen Maturation on Low-Field Nuclear Magnetic Resonance Response

    Science.gov (United States)

    Prasad, M.; Livo, K.

    2017-12-01

    Low-field Nuclear Magnetic Resonance (NMR) is commonly used in petrophysical analysis of petroleum reservoir rocks. NMR experiments record the relaxation and polarization of in-situ hydrogen protons present in gaseous phases such as free-gas intervals and solution gas fluids, bulk fluid phases such as oil and aquifer intervals, and immovable fractions of kerogen and bitumen. Analysis of NMR relaxation spectra is performed to record how fluid composition, maturity, and viscosity change NMR experimental results. We present T1-T2 maps as thermal maturity of a water-saturated, sub-mature Woodford shale is increased at temperatures from 125 to 400 degrees Celsius. Experiments with applied fluid pressure in paraffinic mineral oil and DI water with varying fluid pH have been performed to mimic reservoir conditions in analysis of the relaxation of bulk fluid phases. We have recorded NMR spectra, T1-T2 maps, and fluid diffusion coefficients using a low-field (2 MHz) MagritekTM NMR. CO2 was injected at a pressure of 900 psi in an in house developed NMR pressure vessel made of torlon plastic. Observable 2D NMR shifts in immature kerogen formations as thermal maturity is increased show generation of lighter oils with increased maturity. CO2 injection leads to a decrease in bulk fluid relaxation time that is attributed to viscosity modification with gas presence. pH variation with increased CO2 presence were shown to not effect NMR spectra. From this, fluid properties have been shown to greatly affect NMR readings and must be taken into account for more accurate NMR reservoir characterization.

  13. Clinical application of nuclear magnetic resonance imaging (resistive type) on cardiovascular disease

    International Nuclear Information System (INIS)

    Imai, Hitoshi; Yoshida, Katsuya; Watanabe, Shigeru; Masuda, Yoshiaki; Inagaki, Yoshiaki; Ikehira, Hiroo; Fukuda, Nobuo; Tateno, Yukio.

    1984-01-01

    In order to evaluate the usefulness of Nuclear Magnetic Resonance (NMR) imaging in diagnosing cardiovascular disease, 27 subjects were examined using a 0.1-Tesla resistive type (ASAHI MARK-J). In 10 normal subjects, four cardiac chambers, interventricular septum, aorta, pulmonary vessels and vena cava were clearly identified in NMR imaging. In two patients with old anteroseptal myocardial infarction, anteroseptal wall thinning and left ventricular aneurysm with mural thrombi were demonstrated. In two cases of antrolateral and posterolateral myocardial infarction, however, infarcted areas were not identified in NMR imaging. In one patient with congestive cardiomyopathy, enlarged left ventricle without hypertrophy was recognized. In two patients with hypertrophic obstructive cardiomyopathy, NMR imaging disclosed thickened left ventricular wall associated with its narrowed cavity. A mural thrombus in the right ventricle was distinctly visualized in one patient with cardio-vascular Behcet's disease. In two patients with mitral valve stenosis, enlarged left atrium with a mural thrombus was clearly demonstrated in both cross and longitudinal sections. In three patients with thoratic aortic aneurysm, local dilatation of aorta and mural thrombi were recognized. In four patients with dissecting aortic aneurysm, double channels with an intimal flap in the aorta were visualized in NMR imaging. Mean T 1 values and standard deviations of left ventricle, left ventricular wall, and thrombi were 593+-89, 341+-20, 316+-84 msec, respectively. Mean T 1 values of thrombi were ordinally shorter than those of left ventricule. But some thrombi which might be expected fresh had longer T 1 values. (J.P.N.)

  14. Predicting octane number using nuclear magnetic resonance spectroscopy and artificial neural networks

    KAUST Repository

    Abdul Jameel, Abdul Gani

    2018-04-17

    Machine learning algorithms are attracting significant interest for predicting complex chemical phenomenon. In this work, a model to predict research octane number (RON) and motor octane number (MON) of pure hydrocarbons, hydrocarbon-ethanol blends and gasoline-ethanol blends has been developed using artificial neural networks (ANN) and molecular parameters from 1H nuclear Magnetic Resonance (NMR) spectroscopy. RON and MON of 128 pure hydrocarbons, 123 hydrocarbon-ethanol blends of known composition and 30 FACE (fuels for advanced combustion engines) gasoline-ethanol blends were utilized as a dataset to develop the ANN model. The effect of weight % of seven functional groups including paraffinic CH3 groups, paraffinic CH2 groups, paraffinic CH groups, olefinic -CH=CH2 groups, naphthenic CH-CH2 groups, aromatic C-CH groups and ethanolic OH groups on RON and MON was studied. The effect of branching (i.e., methyl substitution), denoted by a parameter termed as branching index (BI), and molecular weight (MW) were included as inputs along with the seven functional groups to predict RON and MON. The topology of the developed ANN models for RON (9-540-314-1) and MON (9-340-603-1) have two hidden layers and a large number of nodes, and was validated against experimentally measured RON and MON of pure hydrocarbons, hydrocarbon-ethanol and gasoline-ethanol blends; a good correlation (R2=0.99) between the predicted and the experimental data was obtained. The average error of prediction for both RON and MON was found to be 1.2 which is close to the range of experimental uncertainty. This shows that the functional groups in a molecule or fuel can be used to predict its ON, and the complex relationship between them can be captured by tools like ANN.

  15. Nuclear magnetic resonance studies of the regulation of the pentose phosphate pathway

    Energy Technology Data Exchange (ETDEWEB)

    Bolo, Nicolas Robin [Univ. of California, Berkeley, CA (United States)

    1991-11-01

    The goal of this work is to investigate the potential for and limitations of in vivo nuclear magnetic resonance (NMR) spectroscopy for quantitation of glucose flux through the pentose phosphate pathway (shunt). Interest in the shunt is motivated by the possibility that its activity may be greatly increased in cancer and in the pathological states of cardiac and cerebral ischemia. The ability to dynamically monitor flux through the pentose shunt can give new knowledge about metabolism in pathological states. 13C NMR spectroscopy was used to monitor shunt activity by determination of the ratios of [13C-4] to [13C-5]-glutamate, [13C-3] to [13C-2]-alanine or [13C-3] to [13C-2]-lactate produced when [13C-2]-glucose is infused. These methods provide measures of the effect of oxidative stresses on shunt activity in systems ranging from cell free enzyme-substrate preparations to cell suspensions and whole animals. In anaerobic cell free preparations, the fraction of glucose flux through the shunt was monitored with a time resolution of 3 minutes. This work predicts the potential for in vivo human studies of pentose phosphate pathway activity based on the mathematical simulation of the 13C fractional enrichments of C4 and C5-glutamate as a function of shunt activity and on the signal-to- noise ratio acquired in 13C NMR human studies from the current literature.

  16. Radiation damping and reciprocity in nuclear magnetic resonance: the replacement of the filling factor.

    Science.gov (United States)

    Tropp, James; Van Criekinge, Mark

    2010-09-01

    The basic equation describing radiation damping in nuclear magnetic resonance (NMR) is rewritten by means of the reciprocity principle, to remove the dependence of the damping constant upon filling factor - a parameter which is neither uniquely defined for easily measured. The new equation uses instead the transceive efficiency, i.e. the peak amplitude of the radiofrequency B field in laboratory coordinates, divided by the square root of the resistance of the detection coil, for which a simple and direct means of measurement exists. We use the efficiency to define the intrinsic damping constant, i.e. that which obtains when both probe and preamplifier are perfectly matched to the system impedance. For imperfect matching of the preamp, it is shown that the damping constant varies with electrical distance to the probe, and equations are given and simulations performed, to predict the distance dependence, which (for lossless lines) is periodic modulo a half wavelength. Experimental measurements of the radiation-damped free induction NMR signal of protons in neat water are performed at a static B field strength of 14.1T; and an intrinsic damping constant measured using the variable line method. For a sample of 5mm diameter, in an inverse detection probe we measure an intrinsic damping constant of 204 s(-1), corresponding to a damping linewidth of 65 Hz for small tip angles. The predicted intrinsic linewidth, based upon three separate measurements of the efficiency, is 52.3 Hz, or 80% of the measured value. (c) 2010 Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-04-13

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

  18. 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.

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

    International Nuclear Information System (INIS)

    Tunnah, Susan 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. 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 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 accommodate the interpolation of these molecules. The spatial arrangement adopted by each of these species appeared to dictate its effect on the lipids. Doxorubicin and menadione, both known to cause oxidative stress, were added to K562 cells. Although both agents are known to act by different mechanisms, the NMR data and scanning electron microscopy suggested that both caused similar alterations in the membrane organisation and lipid fluidity. Protrusions were formed indicating areas of weakness in the membrane. Spin-echo NMR was employed to investigate the action of the thiol-containing compounds, penicillamine, captopril and N-acetylcysteine in erythrocytes under conditions of oxidative stress. Results indicate that while captopril acts as a free radical scavenger, penicillamine may act as either oxidant or reductant. N-acetylcysteine was observed to act as a reducing agent. (author)

  20. Non-destructive Ripeness Sensing by Using Proton NMR [Nuclear Magnetic Resonance

    Science.gov (United States)

    Cho, Seong In; Krutz, G. W.; Stroshine, R. L.; Bellon, V.

    1990-01-01

    More than 80 kinds of fruits and vegetables are available in the United States. But only about 6 of them have their quality standards (Dull, 1986). In the 1990 Fresh Trends survey (Zind, 1990), consumers were asked to rate 16 characteristics important to their decision to purchase fresh produce. The four top ranking factors were ripeness/freshness, taste/flavor, appearance/condition and nutritional value. Of these surveyed, 96% rated ripeness/freshness as extremely important or very important. Therefore, the development of reliable grading or sorting techniques for fresh commodities is essential. Determination of fruit quality often involves cutting and tasting. Non-destructive quality control in fruit and vegetables is a goal of growers and distributors, as well as the food processing industry. Many nondestructive techniques have been evaluated including soft x-ray, optical transmission, near infrared radiation, and machine vision. However, there are few reports of successful non-destructive measurement of sugar content directly in fruit. Higher quality fruit could be harvested and available to consumers if a nondestructive sensor that detects ripeness level directly by measuring sugar content were available. Using proton Nuclear Magnetic Resonance (NMR) principle is the possibility. A nondestructive ripeness (or sweetness) sensor for fruit quality control can be developed with the proton NMR principle (Cho, 1989). Several feasibility studies were necessary for the ripeness sensor development. Main objectives in this paper was to investigate the feasibilities (1) to detect ripeness (or sweetness level) of raw fruit tissue with an high resolution proton NMR spectroscopy (200 MHz) and (2) to measure sugar content of intact fruit with a low resolution proton NMR spectroscopy (10 MHz).

  1. Absolute quantitative analysis for sorbic acid in processed foods using proton nuclear magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Ohtsuki, Takashi; Sato, Kyoko; Sugimoto, Naoki; Akiyama, Hiroshi; Kawamura, Yoko

    2012-01-01

    Highlights: ► A method using qHNMR was applied and validated to determine SA in processed foods. ► This method has good accuracy, precision, selectiveness, and linearity. ► The proposed method is more rapid and simple than the conventional method. ► We found that the proposed method is reliable for the accurate determination of SA. ► This method can be used for the monitoring of SA in processed foods. - Abstract: An analytical method using solvent extraction and quantitative proton nuclear magnetic resonance (qHNMR) spectroscopy was applied and validated for the absolute quantification of sorbic acid (SA) in processed foods. The proposed method showed good linearity. The recoveries for samples spiked at the maximum usage level specified for food in Japan and at 0.13 g kg −1 (beverage: 0.013 g kg −1 ) were larger than 80%, whereas those for samples spiked at 0.063 g kg −1 (beverage: 0.0063 g kg −1 ) were between 56.9 and 83.5%. The limit of quantification was 0.063 g kg −1 for foods (and 0.0063 g kg −1 for beverages containing Lactobacillus species). Analysis of the SA content of commercial processed foods revealed quantities equal to or greater than those measured using conventional steam-distillation extraction and high-performance liquid chromatography quantification. The proposed method was rapid, simple, accurate, and precise, and provided International System of Units traceability without the need for authentic analyte standards. It could therefore be used as an alternative to the quantification of SA in processed foods using conventional method.

  2. [Applications of nuclear magnetic resonance in the study of soil-plant-atmosphere continuum].

    Science.gov (United States)

    Yao, Shi-jin; Du, Guang-yuan; Mou, Hong-mei; Feng, Hao; Bai, Jiang-ping; He, Jian-qiang

    2016-01-01

    Status and transport of water in plant body are the main contents of study of soil-plant-atmosphere continuum (SPAC), as well as the base for use and regulation of agricultural water. The process of water transport in plant can be deeply influenced by the environments. Thus, plant needs to adjust its water status to accommodate the environmental change to sustain its own growth and development. Traditional methods for plant water monitoring, such as evaporation flux, pressure chamber, high pressure flow meter, heat pulse, and so on, usually cause damage or even destruction of plant body and disturb the original water status. Thus, they are not able to truly and precisely detect and reflect the real water status of plant. Nuclear magnetic resonance (NMR) is a non-destructive and non-invasive technique which can be used for the measurement of water molecular displacement, and transportation. This study aimed to provide an overview of the applications of NMR technique in the study of water distribution and transport in plant roots and stems, as well as the water content in plant cells and tissues. In addition, the existing main problems and possible solutions were analyzed for the applications of NMR in SPAC studies. Several important issues were proposed for the acquisition of more precise and reliable detection signals. It was suggested that the NMR technique would probably make important progress in the relevant fields such as plant water physiology, plantenvironment interactions, and water metabolism. In general, the application of NMR in SPAC system study was still in its infancy in China. The deeper application and expansion of NMR in SPAC study would depend on the development of portable and open NMR equipment that could be easily applied for different plants in field.

  3. Interaction between lidocaine hydrochloride (with and without adrenaline) and various irrigants: A nuclear magnetic resonance analysis.

    Science.gov (United States)

    Vidhya, Nirmal; Karthikeyan, Balasubramanian Saravana; Velmurugan, Natanasabapathy; Abarajithan, Mohan; Nithyanandan, Sivasankaran

    2014-05-01

    Interaction between local anesthetic solution, lidocaine hydrochloride (with and without adrenaline), and root canal irrigants such as sodium hypochlorite (NaOCl), ethylene diamine tetra-acetic acid (EDTA), and chlorhexidine (CHX) has not been studied earlier. Hence, the purpose of this in vitro study was to evaluate the chemical interaction between 2% lidocaine hydrochloride (with and without adrenaline) and commonly used root canal irrigants, NaOCl, EDTA, and CHX. SAMPLES WERE DIVIDED INTO EIGHT EXPERIMENTAL GROUPS: Group I-Lidocaine hydrochloride (with adrenaline)/3% NaOCl, Group II-Lidocaine hydrochloride (with adrenaline)/17% EDTA, Group III- Lidocaine hydrochloride (with adrenaline)/2% CHX, Group IV-Lidocaine hydrochloride (without adrenaline)/3% NaOCl, Group V-Lidocaine hydrochloride (without adrenaline)/17% EDTA, Group VI-Lidocaine hydrochloride (without adrenaline)/2% CHX, and two control groups: Group VII-Lidocaine hydrochloride (with adrenaline)/deionized water and Group VIII-Lidocaine hydrochloride (without adrenaline)/deionized water. The respective solutions of various groups were mixed in equal proportions (1 ml each) and observed for precipitate formation. Chemical composition of the formed precipitate was then analysed by nuclear magnetic resonance spectroscopy (NMR) and confirmed with diazotation test. In groups I and IV, a white precipitate was observed in all the samples on mixing the respective solutions, which showed a color change to reddish brown after 15 minutes. This precipitate was then analysed by NMR spectroscopy and was observed to be 2,6-xylidine, a reported toxic compound. The experimental groups II, III, V, and VI and control groups VII and VIII showed no precipitate formation in any of the respective samples, until 2 hours. Interaction between lidocaine hydrochloride (with and without adrenaline) and NaOCl showed precipitate formation containing 2,6-xylidine, a toxic compound.

  4. Interaction between lidocaine hydrochloride (with and without adrenaline and various irrigants: A nuclear magnetic resonance analysis

    Directory of Open Access Journals (Sweden)

    Nirmal Vidhya

    2014-01-01

    Full Text Available Background: Interaction between local anesthetic solution, lidocaine hydrochloride (with and without adrenaline, and root canal irrigants such as sodium hypochlorite (NaOCl, ethylene diamine tetra-acetic acid (EDTA, and chlorhexidine (CHX has not been studied earlier. Hence, the purpose of this in vitro study was to evaluate the chemical interaction between 2% lidocaine hydrochloride (with and without adrenaline and commonly used root canal irrigants, NaOCl, EDTA, and CHX. Materials and Methods: Samples were divided into eight experimental groups: Group I-Lidocaine hydrochloride (with adrenaline/3% NaOCl, Group II-Lidocaine hydrochloride (with adrenaline/17% EDTA, Group III- Lidocaine hydrochloride (with adrenaline/2% CHX, Group IV-Lidocaine hydrochloride (without adrenaline/3% NaOCl, Group V-Lidocaine hydrochloride (without adrenaline/17% EDTA, Group VI-Lidocaine hydrochloride (without adrenaline/2% CHX, and two control groups: Group VII-Lidocaine hydrochloride (with adrenaline/deionized water and Group VIII-Lidocaine hydrochloride (without adrenaline/deionized water. The respective solutions of various groups were mixed in equal proportions (1 ml each and observed for precipitate formation. Chemical composition of the formed precipitate was then analysed by nuclear magnetic resonance spectroscopy (NMR and confirmed with diazotation test. Results: In groups I and IV, a white precipitate was observed in all the samples on mixing the respective solutions, which showed a color change to reddish brown after 15 minutes. This precipitate was then analysed by NMR spectroscopy and was observed to be 2,6-xylidine, a reported toxic compound. The experimental groups II, III, V, and VI and control groups VII and VIII showed no precipitate formation in any of the respective samples, until 2 hours. Conclusion: Interaction between lidocaine hydrochloride (with and without adrenaline and NaOCl showed precipitate formation containing 2,6-xylidine, a toxic

  5. A proton nuclear magnetic resonance-based metabonomics study of metabolic profiling in immunoglobulin a nephropathy

    Directory of Open Access Journals (Sweden)

    Weiguo Sui

    2012-01-01

    Full Text Available OBJECTIVES: Immunoglobulin A nephropathy is the most common cause of chronic renal failure among primary glomerulonephritis patients. The ability to diagnose immunoglobulin A nephropathy remains poor. However, renal biopsy is an inconvenient, invasive, and painful examination, and no reliable biomarkers have been developed for use in routine patient evaluations. The aims of the present study were to identify immunoglobulin A nephropathy patients, to identify useful biomarkers of immunoglobulin A nephropathy and to establish a human immunoglobulin A nephropathy metabolic profile. METHODS: Serum samples were collected from immunoglobulin A nephropathy patients who were not using immunosuppressants. A pilot study was undertaken to determine disease-specific metabolite biomarker profiles in three groups: healthy controls (N = 23, low-risk patients in whom immunoglobulin A nephropathy was confirmed as grades I-II by renal biopsy (N = 23, and high-risk patients with nephropathies of grades IV-V (N = 12. Serum samples were analyzed using proton nuclear magnetic resonance spectroscopy and by applying multivariate pattern recognition analysis for disease classification. RESULTS: Compared with the healthy controls, both the low-risk and high-risk patients had higher levels of phenylalanine, myo-Inositol, lactate, L6 lipids ( = CH-CH2-CH = O, L5 lipids (-CH2-C = O, and L3 lipids (-CH2-CH2-C = O as well as lower levels of β -glucose, α-glucose, valine, tyrosine, phosphocholine, lysine, isoleucine, glycerolphosphocholine, glycine, glutamine, glutamate, alanine, acetate, 3-hydroxybutyrate, and 1-methylhistidine. CONCLUSIONS: These metabolites investigated in this study may serve as potential biomarkers of immunoglobulin A nephropathy. Point scoring of pattern recognition analysis was able to distinguish immunoglobulin A nephropathy patients from healthy controls. However, there were no obvious differences between the low-risk and high-risk groups in our

  6. 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.

  7. Double-outlet right ventricle: morphologic demonstration using nuclear magnetic resonance imaging.

    Science.gov (United States)

    Parsons, J M; Baker, E J; Anderson, R H; Ladusans, E J; Hayes, A; Fagg, N; Cook, A; Qureshi, S A; Deverall, P B; Maisey, M N

    1991-07-01

    Sixteen patients with double-outlet right ventricle, aged 1 week to 29 years (median 5 months), were studied with a 1.5 tesla nuclear magnetic resonance (NMR) imaging scanner. Two-dimensional echocardiography was performed in all patients. Thirteen patients underwent angiography, including nine who underwent subsequent surgical correction. Three patients underwent postmortem examination. Small children and infants were scanned inside a 32 cm diameter proton head coil. Multiple 5 mm thick sections separated by 0.5 mm and gated to the patient's electrocardiogram were acquired with a spin-echo sequence and an echo time of 30 ms. A combination of standard and oblique imaging planes was used. Imaging times were less than 90 min. The NMR images were technically unsuitable in one patient because of excessive motion artifact. In the remaining patients, the diagnosis of double outlet right ventricle was confirmed and correlated with surgical and postmortem findings. The NMR images were particularly valuable in demonstrating the interrelations between the great arteries and the anatomy of the outlet septum and the spatial relations between the ventricular septal defect and the great arteries. Although the atrioventricular (AV) valves were not consistently demonstrated, NMR imaging in two patients identified abnormalities of the mitral valve that were not seen with two-dimensional echocardiography. In one patient who had a superoinferior arrangement of the ventricles, NMR imaging was the most useful imaging technique for demonstrating the anatomy. In patients with double-outlet right ventricle, NMR imaging can provide clinically relevant and accurate morphologic information that may contribute to future improvement in patient management.

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

    International Nuclear Information System (INIS)

    Um, So Young; Park, Jung Hyun; Chung, Myeon Woo; Kim, Kyu-Bong; Kim, Seon Hwa; Choi, Ki Hwan; Lee, Hwa Jeong

    2012-01-01

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

  9. Density functional theory computation of Nuclear Magnetic Resonance parameters in light and heavy nuclei

    Science.gov (United States)

    Sutter, Kiplangat

    This thesis illustrates the utilization of Density functional theory (DFT) in calculations of gas and solution phase Nuclear Magnetic Resonance (NMR) properties of light and heavy nuclei. Computing NMR properties is still a challenge and there are many unknown factors that are still being explored. For instance, influence of hydrogen-bonding; thermal motion; vibration; rotation and solvent effects. In one of the theoretical studies of 195Pt NMR chemical shift in cisplatin and its derivatives illustrated in Chapter 2 and 3 of this thesis. The importance of representing explicit solvent molecules explicitly around the Pt center in cisplatin complexes was outlined. In the same complexes, solvent effect contributed about half of the J(Pt-N) coupling constant. Indicating the significance of considering the surrounding solvent molecules in elucidating the NMR measurements of cisplatin binding to DNA. In chapter 4, we explore the Spin-Orbit (SO) effects on the 29Si and 13C chemical shifts induced by surrounding metal and ligands. The unusual Ni, Pd, Pt trends in SO effects to the 29Si in metallasilatrane complexes X-Si-(mu-mt)4-M-Y was interpreted based on electronic and relativistic effects rather than by structural differences between the complexes. In addition, we develop a non-linear model for predicting NMR SO effects in a series of organics bonded to heavy nuclei halides. In chapter 5, we extend the idea of "Chemist's orbitals" LMO analysis to the quantum chemical proton NMR computation of systems with internal resonance-assisted hydrogen bonds. Consequently, we explicitly link the relationship between the NMR parameters related to H-bonded systems and intuitive picture of a chemical bond from quantum calculations. The analysis shows how NMR signatures characteristic of H-bond can be explained by local bonding and electron delocalization concepts. One shortcoming of some of the anti-cancer agents like cisplatin is that they are toxic and researchers are looking for

  10. Acoustic transparency and slow sound using detuned acoustic resonators

    DEFF Research Database (Denmark)

    Santillan, Arturo Orozco; Bozhevolnyi, Sergey I.

    2011-01-01

    We demonstrate that the phenomenon of acoustic transparency and slowsound propagation can be realized with detuned acoustic resonators (DAR), mimicking thereby the effect of electromagnetically induced transparency (EIT) in atomic physics. Sound propagation in a pipe with a series of side...

  11. Rheo-NMR - how nuclear magnetic resonance is providing new insight regarding complex fluid rheology

    International Nuclear Information System (INIS)

    Callaghan, P.T.

    2000-01-01

    Over the past five decades, NMR has revolutionised chemistry, and has found widespread application in condensed matter physics, in molecular biology, in medicine and in food technology. Most recently NMR has made a significant impact in chemical engineering, where it is being extensively used for the non-invasive study of dispersion and flow in porous media. One of the most recent applications of NMR in materials science concerns its use in the study of the mechanical properties of complex fluids. This particular aspect of NMR has been extensively developed in research carried out at Massey University in New Zealand. In this short article, some of the ideas behind this work and the applications which have resulted, will be described. These examples provide a glimpse of possible applications of Nuclear Magnetic Resonance to the study of complex fluid rheology. While this is a very new field of research in which only a handful of groups presently participate, the potential exists for a substantial increase in Rheo-NMR research activity. Systems studied to date include polymer melts and semi-dilute solutions, thermotropic and lyotropic liquid crystals and liquid crystalline polymers, micellar solutions, food materials and colloidal suspensions. Rheo-NMR suffers in a number of respects by comparison with optical methods. It is expensive, it is difficult to use, it suffers from poor signal-to-noise ratios and the effective interpretation of spectra often depends on familiarity with the nuclear spin Hamiltonian and the associated effects of spin dynamics. Nonetheless NMR offers some unique advantages, including the ability to work with opaque materials, the ability to combine velocimetry with localised spectroscopy, and the ability to access a wide range of molecular properties relating to organisation, orientation and dynamics. Rheo-NMR has been able to provide a direct window on a variety of behaviours, including slip, shear-thinning, shear banding, yield stress

  12. High-pressure nuclear magnetic resonance studies of fuel cell membranes

    Science.gov (United States)

    Mananga, Eugene Stephane

    water at different concentrations: proton (1H) and phosphorus (31P) nuclei have been performed using the static field gradient spin-echo nuclear magnetic resonance. This study is expected to be helpful in improving the understanding of phosphoric acid fuel cell technology.

  13. Cardiac magnetic resonance imaging

    African Journals Online (AJOL)

    2011-03-06

    Mar 6, 2011 ... Cardiac magnetic resonance imaging. Cardiovascular magnetic resonance imaging is becoming a routine diagnostic technique. BRUCE s sPOTTiswOOdE, PhD. MRC/UCT Medical Imaging Research Unit, University of Cape Town, and Division of Radiology, Stellenbosch University. Bruce Spottiswoode ...

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

    International Nuclear Information System (INIS)

    Meyerspeer, M.

    2005-09-01

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

  15. Parameters and definitions in applied technique quality test for nuclear magnetic resonance imaging system (NMRI)

    International Nuclear Information System (INIS)

    Lin Zhikai; Zhao Lancai

    1999-08-01

    During the past two decades, medical diagnostic imaging technique has achieved dramatic development such as CT, MRI, PET, DSA and so on. The most striking examples of them are the application of X ray computerized tomography (CT) and magnetic resonance imaging in the field of medical diagnosis. It can be predicted that magnetic resonance imaging (MRI) will definitely have more widespread prospects of applications and play more and more important role in clinical diagnosis looking forward to the development of image diagnostic technique for 21 st century. The authors also present the measuring methods for some parameters. The parameters described can be used for reference by clinical diagnosticians, operators on MRI and medical physicists who engages in image quality assurance (QA) and control (QC) in performing MRI acceptance test and routine test

  16. 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)

  17. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses ... of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical ...

  18. Nuclear magnetic resonance investigation of water accessibility in cellulose of pretreated sugarcane bagasse.

    Science.gov (United States)

    Tsuchida, Jefferson Esquina; Rezende, Camila Alves; de Oliveira-Silva, Rodrigo; Lima, Marisa Aparecida; d'Eurydice, Marcel Nogueira; Polikarpov, Igor; Bonagamba, Tito José

    2014-01-01

    Enzymatic hydrolysis is a crucial step of biomass conversion into biofuels and different pretreatments have been proposed to improve the process efficiency. Amongst the various factors affecting hydrolysis yields of biomass samples, porosity and water accessibility stand out due to their intimate relation with enzymes accessibility to the cellulose and hemicellulose fractions of the biomass. In this work, sugarcane bagasse was subjected to acid and alkali pretreatments. The changes in the total surface area, hydrophilicity, porosity and water accessibility of cellulose were investigated by scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR). Changes in chemical and physical properties of the samples, caused by the partial removal of hemicellulose and lignin, led to the increase in porosity of the cell walls and unwinding of the cellulose bundles, as observed by SEM. (1)H NMR relaxation data revealed the existence of water molecules occupying the cores of wide and narrow vessels as well as the cell wall internal structure. Upon drying, the water molecules associated with the structure of the cell wall did not undergo significant dynamical and partial moisture changes, while those located in the cores of wide and narrow vessels kept continuously evaporating until reaching approximately 20% of relative humidity. This indicates that water is first removed from the cores of lumens and, in the dry sample, the only remaining water molecules are those bound to the cell walls. The stronger interaction of water with pretreated bagasse is consistent with better enzymes accessibility to cellulose and higher efficiency of the enzymatic hydrolysis. We were able to identify that sugarcane bagasse modification under acid and basic pretreatments change the water accessibility to different sites of the sample, associated with both bagasse structure (lumens and cell walls) and hydrophilicity (lignin removal). Furthermore, we show that the substrates with increased

  19. Measurement of soil carbon oxidation state and oxidative ratio by 13C nuclear magnetic resonance

    Science.gov (United States)

    Hockaday, W.C.; Masiello, C.A.; Randerson, J.T.; Smernik, R.J.; Baldock, J.A.; Chadwick, O.A.; Harden, J.W.

    2009-01-01

    The oxidative ratio (OR) of the net ecosystem carbon balance is the ratio of net O2 and CO2 fluxes resulting from photosynthesis, respiration, decomposition, and other lateral and vertical carbon flows. The OR of the terrestrial biosphere must be well characterized to accurately estimate the terrestrial CO2 sink using atmospheric measurements of changing O2 and CO2 levels. To estimate the OR of the terrestrial biosphere, measurements are needed of changes in the OR of aboveground and belowground carbon pools associated with decadal timescale disturbances (e.g., land use change and fire). The OR of aboveground pools can be measured using conventional approaches including elemental analysis. However, measuring the OR of soil carbon pools is technically challenging, and few soil OR data are available. In this paper we test three solid-state nuclear magnetic resonance (NMR) techniques for measuring soil OR, all based on measurements of the closely related parameter, organic carbon oxidation state (Cox). Two of the three techniques make use of a molecular mixing model which converts NMR spectra into concentrations of a standard suite of biological molecules of known C ox. The third technique assigns Cox values to each peak in the NMR spectrum. We assess error associated with each technique using pure chemical compounds and plant biomass standards whose Cox and OR values can be directly measured by elemental analyses. The most accurate technique, direct polarization solid-state 13C NMR with the molecular mixing model, agrees with elemental analyses to ??0.036 Cox units (??0.009 OR units). Using this technique, we show a large natural variability in soil Cox and OR values. Soil Cox values have a mean of -0.26 and a range from -0.45 to 0.30, corresponding to OR values of 1.08 ?? 0.06 and a range from 0.96 to 1.22. We also estimate the OR of the carbon flux from a boreal forest fire. Analysis of soils from nearby intact soil profiles imply that soil carbon losses associated

  20. Nano-Pore Characterization of Shale Using Nuclear Magnetic Resonance Cryoporometry

    Science.gov (United States)

    Dong, Y.; Zhang, Q.; Tong, S.

    2016-12-01

    Considering that most matrix pore sizes of shale rock are at scales of a few nanometers to microns, charactering nano-pore the pore structure are therefore significant and imperative for shale gas production. However, to accurately characterize the pore structure of shale remains a challenging task in geoscience community due to the complexity and heterogeneity of the shale pore structure. Various techniques such as Scanning Electron Microscope (SEM), Mercury Intrusion Porosimetry (MIP), Nitrogen Adsorption Method (NAM) and X-ray Computerized Tomography (XCT) all have a limited measuring range and could not cover the entire nanometer-range. This work reported nano-pore characterization of shale rock in Sichuan, China using nuclear magnetic resonance cryoporometry (NMRC), a novel and emerging technique which can probe pore size distributions from nano- to micro- scales. First, the method was validated using two materials with pre-known pore structures, a molecular sieve SBA-15 with a pore diameter of 8 nm and a controlled pore glass with a pore diameter of 24 nm. The NMRC results of two martials show a good accuracy for quantifying pore size distribution. Both bulk matrix specimens and pulverized shale samples were tested using NMRC, and two liquids, water and cyclohexane, were used to saturate the samples for NMRC experiments. MIP, NAM as well as NanoCT were also employed to validate the NMRC results. The results show that MIP was comparable to NMRC with bulk sample and NAM was similar to NMRC with pulverized sample. The porosity for bulk and pulverized sample is 3.2% and 5.7% respectively, showing that a lot of pores were connected during pulverizing process. The results for samples saturated with water and cyclohexane are similar, which demonstrates that water-rock interaction was not active during experiment due to the low temperature. However, cyclohexane has a greater Gibbs-Thomoson coefficient than water, meaning that NMRC with cyclohexane has a better

  1. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging (MRI) Safety Contrast Materials Children ...

  2. PARAMETERS OF NUCLEAR MAGNETIC RESONANCE IN PATIENTS WITH CONGENITAL NARROWING OF THE LUMBAR SPINAL CANAL

    Directory of Open Access Journals (Sweden)

    ELIU HAZAEL MORALES-RANGEL

    Full Text Available ABSTRACT Objective: To compare the morphological parameters of magnetic resonance in patients with congenital narrowing of the lumbar spinal canal with patients with low back pain. Methods: A descriptive, retrospective, observational study was conducted with measurements in the axial and sagittal magnetic resonance sections of the vertebral body and canal of the lumbar spine of 64 patients with diagnosis of low back pain, which were compared with resonance images taken from 31 Mexican patients with congenital narrowing of the lumbar spinal canal. Results: The results show that patients with congenital narrowing of the lumbar spinal canal in the axial sections have a difference in diameters, being L2<13.9 mm, L3<13.3 mm, L4<12.9 mm, L5<13.1 mm, compared with controls L2<20.5 mm, L3<20.5 mm, L4<19.3 mm, L5<18.1 mm with p = 0.000. Conclusions: We found different measurements in the Mexican population compared to those found by similar studies. With the parameters obtained, it would be possible to make the proper diagnosis, surgical planning, and treatment.

  3. Nuclear magnetic resonance applied to the study of polymeric nano composites

    International Nuclear Information System (INIS)

    Tavares, Maria Ines Bruno

    2011-01-01

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

  4. Humanitarian mine detection by acoustic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kercel, S.W.

    1998-03-01

    The JASON Committee at MITRE Corp. was tasked by DARPA to inquire into suitable technologies for humanitarian mine detection. Acoustic resonance was one of the very few technologies that the JASONs determined might be promising for the task, but was as yet unexplored at the time that they conducted their inquiry. The objective of this Seed Money investigation into acoustic resonance was to determine if it would be feasible to use acoustic resonance to provide an improvement to present methods for humanitarian mine detection. As detailed in this report, acoustic resonance methods do not appear to be feasible for this task. Although acoustic resonant responses are relatively easy to detect when they exist, they are very difficult to excite by the non-contact means that must be used for buried objects. Despite many different attempts, this research did not discover any practical means of using sound to excite resonant responses in objects known to have strong resonances. The shaker table experiments did see an effect that might be attributable to the resonance of the object under test, but the effect was weak, and exploited the a priori knowledge of the resonant frequency of the object under test to distinguish it from the background. If experiments that used objects known to have strong acoustic resonances produced such marginal results, this does not seem to be a practical method to detect objects with weak resonances or non-existent resonances. The results of this work contribute to the ORNL countermine initiative. ORNL is exploring several unconventional mine detection technologies, and is proposed to explore others. Since this research has discovered some major pitfalls in non-metallic mine detection, this experience will add realism to other strategies proposed for mine detection technologies. The experiment provided hands-on experience with inert plastic mines under field conditions, and gives ORNL additional insight into the problems of developing practical

  5. Application of electronic paramagnetic, nuclear magnetic, γ-nuclear magnetic resonance, and defibrillation in experimental biology and medecine

    Science.gov (United States)

    Piruzyan, L. A.

    2005-08-01

    Nowadays an attention is paid to pathbreaking approaches to the therapy of different pathologies with EPR, NMR and NGR dialysis and mechanisms of physical factors influence in prophylactics and therapy of a number of diseases. Any pathology is evidently begins its development in atomic-molecular levels earlier then any morphologic alterations in tissues can be detected. We have studied the alterations of FR content in liver, spleen and brain in hypoxia and hyperoxia conditions. Under hypoxia and hyperoxia the FR concentrations are equal in all organs and tissues. However this ratio is different for some forms of leucosis. For different leucosis types gas mixtures the most adequate for the current pathology should be developed. Then we represent the method of biologic objects treatment with the energy of super-high frequency field (SIT) and the instrument for its performance. The study of magnetic heterogeneity of biologic systems proposes the new approach and a set of methods for medical and scientific purpose. Application of combined with chemotherapy extraction of anionic and cationic radicals from bloodstream using EPRD, NMRD and NGRD influence and also the single ions separate extraction using NGRD are able to detect and perhaps to cure their appearance in a period before neoformation. These studies should be carried out experimentally and clinically.

  6. Synthesis and purification of some alkyl phenanthrenes and presentation of their infrared, ultraviolet, nuclear magnetic resonance and mass spectra

    International Nuclear Information System (INIS)

    Persaud, K.

    1965-01-01

    We have carried out the synthesis of: - phenanthrene - its five monomethyl derivatives - three dimethyl derivatives - two trimethyl derivatives. We have then purified these products as well as a certain number of others obtained from various sources. We have been able to obtain in the majority of cases, a purity of 99.5 per cent or over, these figures being obtained by low voltage mass spectrometry. Finally we have recorded the infrared, ultraviolet, nuclear magnetic resonance and mass spectra of these products for which an atlas has been drawn up. (author) [fr

  7. Cross polarization, magic-angle spinning /sup 13/C nuclear magnetic resonance spectroscopy of soil humic fractions

    Energy Technology Data Exchange (ETDEWEB)

    Saiz-Jimenez, C.; Hawkins, B.L.; Maciel, G.E.

    1986-01-01

    Cross polarization, magic-angle spinning /sup 13/C nuclear magnetic resonance spectroscopy was used to characterize humic fractions isolated from different soils. The humic acid fractions are more aromatic than the humin fractions, probably due to the higher polysaccharide content of humins. However, fulvic acid fractions are more aromatic than the corresponding humic acid and humin fractions. These results can be interpreted in terms of the isolation procedure, because the high affinity of Polyclar AT for phenols results in higher aromaticities as compared with other isolation methods (e.g. charcoal).

  8. 27Al Magic Angle Spinning–Nuclear Magnetic Resonance (MAS-NMR) Analyses Applied to Historical Mortars

    Czech Academy of Sciences Publication Activity Database

    Hanzlíček, Tomáš; Perná, Ivana; Brus, Jiří

    2013-01-01

    Roč. 7, č. 2 (2013), s. 153-164 ISSN 1558-3058 R&D Projects: GA AV ČR IAA300460702 Institutional research plan: CEZ:AV0Z30460519; CEZ:AV0Z40500505 Keywords : mortars * magic angle spinning –nuclear magnetic resonance (MAS-NMR) in solid state * alumina-silicates Subject RIV: DM - Solid Waste and Recycling Impact factor: 0.714, year: 2013 http://www.tandfonline.com/doi/abs/10.1080/15583058.2011.624253

  9. Detection of carbanions in aqueous solution by nuclear magnetic resonance spectroscopy. Hydrogen--deuterium exchange reactions of aromatic mercaptals

    International Nuclear Information System (INIS)

    Pesek, J.J.; Mitchell, S.J.

    1976-01-01

    Carbanions are detected in basic aqueous solution by hydrogen-deuterium exchange at the acidic carbon. Both proton and carbon-13 nuclear magnetic resonance spectroscopy can be used to observe the H-D exchange. The proton nmr spectra can be used to quantitatively determine the exchange rate. Mercaptals are studied because the two sulfur atoms adjacent to the acidic carbon favor carbanion formation. It is found that only when the acidic carbon has an aromatic substituent can hydrogen-deuterium exchange be observed

  10. Nuclear magnetic resonance in the neonatal period and prediction of the neuro development evolution in premature newborns

    International Nuclear Information System (INIS)

    Oreiro, Vilma

    2007-01-01

    The nuclear magnetic resonance (RMN) is outlined as a progressively more accessible study. The new technology allows, even to omit the sedation of children. In the last 10 years, we have had access to the knowledge of the modifications shown by the brain of the premature newborn in growth as well as in cerebral structures. In 2003, a detailed description was published concerning the technology used to evaluate the images of premature newborns and the evolution of these images according to the own modifications of the progress during the post-conception age [es

  11. Hydration effect on solid DNA-didecyldimethylammonium chloride complexes measured using 1H-nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Nizioł, J.; Harańczyk, H.; Kobierski, J.; Hebda, E.; Pielichowski, J.; Ostachowicz, B.

    2013-10-01

    Complexes like the studied DNA and didecyldimethylammonium chloride are promising materials for organic electronics and photonics. Water content in this material as the solid state is a key factor for its electronics properties and microstructure. DNA complex was subjected to controlled hydration from gaseous phase and next studied by 1H-nuclear magnetic resonance spectroscopy. Variations of spin-spin and spin-lattice relaxation times as a function of hydration level are reported. Formation of tightly and loosely bound water fractions at rehydration process is discussed.

  12. Designing and Fabrication of a New Radiofrequency Planar microcoil for mini-Nuclear Magnetic Resonance

    Directory of Open Access Journals (Sweden)

    Sayyede Batoul Shokouhian

    2016-09-01

    Full Text Available Introduction Radiofrequency planar microcoils are used to increase the resolution of magnetic resonance images of small samples. In this study, we aimed to design and fabricate a spiral planar microcoil constructed on a double-sided printed circuit board (PCB. It has four rings with an internal diameter of 241 microns tuned and matched at 63.8 MHz. Materials and Methods To achieve the maximum signal-to- noise ratio (SNR and quality factor of the coil, its geometry was optimized based on parameters such as width (w and thickness (h of the copper rings, the distance between the rings, inner radius of the microcoil  (Ri, and the number (N of coil rings by using COMSOL, ADS, and MATLAB software packages. Results Our findings indicated that the Q factor and SNR of the coil at resonance frequency of 63.8 MHz are 63.149 and 168.23, respectively, which are higher than the equivalent features of the pervious coils. In addition, to evaluate the function of matching and tuning circuit, reflection coefficient factor (S11 of the coil was experimentally measured to be -48 dB at resonance frequency of 63.8 MHz, which is consistent with the simulated value. Conclusion In this study, a new microcoil was designed and fabricated to produce images of very small samples and volumes in microliter dimensions. The results showed that this new microcoil has superior capability in imaging very small samples compared to the conventional coils applied in magnetic resonance imaging devices.

  13. Contribution of magnetic nuclear resonance to the diagnosis of Creutzfeldt-Jakob disease

    Directory of Open Access Journals (Sweden)

    Leonardo Cordenonzi Pedroso de Albuquerque

    2015-12-01

    Laboratory tests showed mild elevation in anti-TPO titer. Other laboratory studies were normal. EEG showed a semi-periodic pattern of widespread sharp-wave discharges with periods of an arrhythmic widespread theta waves. Brain magnetic resonance imaging (MRI showed hyperintensity on FLAIR and decreased diffusivity in the basal ganglia, specially in the head of caudate and putamen, as well as in the cortex of frontal lobes bilaterally, left parietal lobe and bilateral occipital lobes on diffusion weighted images (DWI and apparent diffusion map (ADC. There was no gadolinium enhancement. Diagnosis of probable Creutzfeldt-Jakob disease was made.

  14. Magnetic Resonance Cholangiopancreatography (MRCP)

    Science.gov (United States)

    ... cholangiopancreatography (ERCP). ERCP is a diagnostic procedure that combines endoscopy , which uses an illuminated optical instrument to ... The teddy bear denotes child-specific content. Related Articles and Media Magnetic Resonance Imaging (MRI) Safety Biliary ...

  15. Magnetic resonance angiography (MRA)

    International Nuclear Information System (INIS)

    Arlart, I.P.; Guhl, L.

    1992-01-01

    An account is given in this paper of the physical and technical principles underlying the 'time-of-flight' technique for imaging of vessels by magnetic resonance tomography. Major indications for the new procedure of magnetic resonance angiography at present are intracerebral and extracerebral vessels, with digital subtraction angiography quite often being required to cope with minor alterations (small aneurysms, small occlusions). Magnetic resonance angiography and digital subtraction angiography are compared to each other for advantages and disadvantages. Basically, replacement of radiological angiography by magnetic resonance angiography appears to be possible only within limits, since X-ray diagnostics primarily provides morphological information about vessels, whereas flow dynamics is visualized by the 'time-of-flight' technique. (orig.) [de

  16. Nuclear magnetic resonance investigation of the heavy fermion system Ce2CoAl7Ge4

    Science.gov (United States)

    Dioguardi, A. P.; Guzman, P.; Rosa, P. F. S.; Ghimire, N. J.; Eley, S.; Brown, S. E.; Thompson, J. D.; Bauer, E. D.; Ronning, F.

    2017-12-01

    We present nuclear magnetic resonance (NMR) and nuclear quadrupole resonance (NQR) measurements performed on single crystalline Ce2CoAl7Ge4 , a member of a recently discovered family of heavy fermion materials Ce2M Al7Ge4 (M =Co , Ir, Ni, or Pd). Previous measurements indicated a strong Kondo interaction as well as magnetic order below TM=1.8 K . Our NMR spectral measurements show that the Knight shift K is proportional to the bulk magnetic susceptibility χ at high temperatures. A clear Knight shift anomaly (K ¬∝χ ) is observed at coherence temperatures T*˜17.5 K for H0∥c ̂ and 10 K for H0∥a ̂ at the 59Co site, and T*˜12.5 K at the 27Al(3) site for H0∥a ̂ characteristic of the heavy fermion nature of this compound. At high temperatures, the 59Co NMR spin-lattice relaxation rate T1-1 is dominated by spin fluctuations of the 4 f local moments with a weak metallic background. The spin fluctuations probed by 59Co NMR are anisotropic and larger in the basal plane than in the c direction. Furthermore, we find (T1T K ) -1∝T-1 /2 at the 59Co site as expected for a Kondo system for T >T* and T >TK . 59Co NQR T1-1 measurements at low temperatures indicate slowing down of spin fluctuations above the magnetic ordering temperature TM˜1.8 K . A weak ferromagnetic character of fluctuations around q =0 is evidenced by an increase of χ T versus T above the magnetic ordering temperature. We also find good agreement between the observed and calculated electric field gradients at all observed sites.

  17. Magnetic resonance imaging

    International Nuclear Information System (INIS)

    Robertson, Angus

    1990-01-01

    An assessment is made of the clinical benefits of expensive diagnostic technology, such as the magnetic resonance imaging. It is concluded that to most radiologists, magnetic resonance imaging has a definite place in the diagnostic scenario, especially for demonstrating central nervous system lesions in multiple sclerosis. While it is recognized that medical and financial resources are limited, it is emphasised that the cost to society must be balanced against the patient benefit. 17 refs

  18. Laser magnetic resonance spectroscopy

    International Nuclear Information System (INIS)

    Ferrari, C.A.

    1985-01-01

    The technique of laser resonance magnetic resonance allows one to study the high-resolution spectroscopy of transient paramagnetic species, viz, atoms, radicals, and molecular ions. This article is a brief exposition of the method, describing the principles, instrumentation and applicability of the IR and FIR-LMR and shows results of HF + . (Author) [pt

  19. Nuclear magnetic resonance studies on bacterial dihydrofolate reductase containing (methyl-/sup 13/C)methionine

    Energy Technology Data Exchange (ETDEWEB)

    Blakley, R.L.; Cocco, L.; London, R.E.; Walker, T.E.; Matwiyoff, N.A.

    1978-06-13

    (methyl-/sup 13/C)Methionine has been incorporated with high efficiency by Streptococcus faecium var. Durans strain A into dihydrofolate reductase isoenzyme 2. In the /sup 13/C NMR spectrum of the purified enzyme the resonances corresponding to the seven methionine residues are partially resolved into three composite peaks. Denaturation with urea collapses these into a single peak centered at 15.32 ppm, whereas the resonance of free methionine is at 15.04 ppm. Spectra of the free enzyme, its complex with methotrexate, and its complex with methotrexate and reduced nicotinamide adenine dinucleotide phosphate (NADPH) have been simulated, permitting more accurate estimates of line widths and nuclear Overhauser enhancement (NOE) values. These, together with the T/sub 1/ values, cannot be explained solely by the effects of macromolecular tumbling and very rapid rotation of the methionine methyl group about its axis. A model assuming, in addition, the occurrence of free rotation about the methionine CH/sub 2/-S bond is also unsatisfactory, and it is concluded that internal rotation about the CH/sub 2/-S bond is highly restricted so that the methyl group oscillates through a relatively narrow angular range. Complex formation with NADPH produced rather small changes in the spectrum of the native enzyme, probably due to conformational transitions in the enzyme. However, NADP/sup +/ produced several changes,including movement of one resonance downfield by at least 1.7 ppM.

  20. Experimental nuclear magnetic resonance spectral assignments, 1H/13C GIAO calculations, molecular structure and molecular resonance states of 4-Methyl-1H-Indazole-5-Boronic acid

    Science.gov (United States)

    Dikmen, Gökhan

    2018-03-01

    Some molecules such as 4-Methyl-1H-Indazole-5-Boronic Acid (4M1HI5BA) have different resonance states under different temperatures. Henceforth, it is difficult to characterize these type of molecules. Since, in general one or more hydrogen atoms move through the molecule and molecular symmetry changes. The possible 3 different resonance forms and molecular structure of 4-Methyl-1H-Indazole-5-Boronic Acid (4M1HI5BA) molecule have been studied experimentally using nuclear magnetic resonance (NMR) spectroscopy. 13C cross-polarization magic-angle spinning, 11B, 1H, 13C, COSY, HMBC, NOESY, T1 relaxation time NMR spectra of 4M1HI5BA molecule have been reported. Moreover, 1H NMR spectra were obtained in different solvents and under variable temperatures. Results from experimental datas showed that title molecule has three different resonance states and these resonance states change with different temperature. In addition, 1H and 13C chemical shift values were calculated by GIAO method and computed values were compared with experimentally obtained values. There are good agreement between experimental and theoretical chemical shift values.

  1. Contrast agents in magnetic resonance imaging

    International Nuclear Information System (INIS)

    Karadjian, V.

    1987-01-01

    The origine of nuclear magnetic resonance signal is reminded and different ways for contrast enhancement in magnetic resonance imaging are presented, especially, modifications of tissus relaxation times. Investigations have focused on development of agents incorporating either paramagnetic ions or stable free radicals. Pharmacological and toxicological aspects are developed. The diagnostic potential of these substances is illustrated by the example of gadolinium complexes [fr

  2. Prediction of beef color using time-domain nuclear magnetic resonance (TD-NMR) relaxometry data and multivariate analyses.

    Science.gov (United States)

    Moreira, Luiz Felipe Pompeu Prado; Ferrari, Adriana Cristina; Moraes, Tiago Bueno; Reis, Ricardo Andrade; Colnago, Luiz Alberto; Pereira, Fabíola Manhas Verbi

    2016-05-19

    Time-domain nuclear magnetic resonance and chemometrics were used to predict color parameters, such as lightness (L*), redness (a*), and yellowness (b*) of beef (Longissimus dorsi muscle) samples. Analyzing the relaxation decays with multivariate models performed with partial least-squares regression, color quality parameters were predicted. The partial least-squares models showed low errors independent of the sample size, indicating the potentiality of the method. Minced procedure and weighing were not necessary to improve the predictive performance of the models. The reduction of transverse relaxation time (T 2 ) measured by Carr-Purcell-Meiboom-Gill pulse sequence in darker beef in comparison with lighter ones can be explained by the lower relaxivity Fe 2+ present in deoxymyoglobin and oxymyoglobin (red beef) to the higher relaxivity of Fe 3+ present in metmyoglobin (brown beef). These results point that time-domain nuclear magnetic resonance spectroscopy can become a useful tool for quality assessment of beef cattle on bulk of the sample and through-packages, because this technique is also widely applied to measure sensorial parameters, such as flavor, juiciness and tenderness, and physicochemical parameters, cooking loss, fat and moisture content, and instrumental tenderness using Warner Bratzler shear force. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  3. 57Fe internal field nuclear magnetic resonance and Mössbauer spectroscopy study of Li-Zn ferrites

    Science.gov (United States)

    Anupama, A. V.; Manjunatha, M.; Rathod, V.; Jali, V. M.; Damle, R.; Ramesh, K. P.; Sahoo, B.

    2018-01-01

    We report the internal field nuclear magnetic resonance (IFNMR) and Mössbauer spectroscopy study of Li-Zn ferrites at RT. The results were supported by the IFNMR data measured at 77 K. As Zn concentration increases the IFNMR echo amplitude decreases and below certain Zn concentration no signal was detected. At RT the echo amplitude vanishes at a lower Zn concentration, whereas at 77 K, the echo amplitude does not vanish completely (except for pure Zn-ferrite). However, in Mössbauer spectroscopy at RT, we have observed magnetically ordered state of all the Li-Zn ferrite samples. This discrepancy could be related to the difference between the time scale of detection of the spins by Mössbauer spectroscopy (10-7-10-10 s) and NMR spectroscopy (10-6 s). Hence, sensitivity of zero-field NMR depends on the magnetic hyperfine field, temperature and abundance of the magnetic cations at the lattice of the spinel ferrites. We have demonstrated that the 'two-equal-pulses' sequence leads to higher echo signal than the spin echo pulse sequence due to the presence of distribution of internal magnetic fields throughout the material. We obtained a limiting value for the fraction of spins needed to produce an echo signal at a particular temperature and at a particular site of the Li-Zn ferrite spinels that can be sensitively detected by pulsed IFNMR technique.

  4. 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.

  5. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses a powerful magnetic field, radio ...

  6. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful magnetic field, radio waves and a computer to produce ...

  7. Acoustic Resonance between Ground and Thermosphere

    Directory of Open Access Journals (Sweden)

    M Matsumura

    2009-04-01

    Full Text Available Ultra-low frequency acoustic waves called "acoustic gravity waves" or "infrasounds" are theoretically expected to resonate between the ground and the thermosphere. This resonance is a very important phenomenon causing the coupling of the solid Earth, neutral atmosphere, and ionospheric plasma. This acoustic resonance, however, has not been confirmed by direct observations. In this study, atmospheric perturbations on the ground and ionospheric disturbances were observed and compared with each other to confirm the existence of resonance. Atmospheric perturbations were observed with a barometer, and ionospheric disturbances were observed using the HF Doppler method. An end point of resonance is in the ionosphere, where conductivity is high and the dynamo effect occurs. Thus, geomagnetic observation is also useful, so the geomagnetic data were compared with other data. Power spectral density was calculated and averaged for each month. Peaks appeared at the theoretically expected resonance frequencies in the pressure and HF Doppler data. The frequencies of the peaks varied with the seasons. This is probably because the vertical temperature profile of the atmosphere varies with the seasons, as does the reflection height of infrasounds. These results indicate that acoustic resonance occurs frequently.

  8. Proton nuclear magnetic resonance characterization of resins from the family pinaceae.

    Science.gov (United States)

    Lambert, Joseph B; Kozminski, Michael A; Fahlstrom, Carl A; Santiago-Blay, Jorge A

    2007-02-01

    Proton magnetic resonance spectra were recorded for solutions of resinous materials harvested from 82 species in seven genera of the gymnospermous plant family Pinaceae. Data were recorded in both one and two (COSY) dimensions. Approximately 11 peaks in the 1D spectra and 10 cross-peaks in the 2D spectra were present in almost all pinacean spectra, providing a familial diagnostic. Some 40 1D peaks or peak clusters and 60 2D cross-peaks or clusters were considered significant and are reported, when present, for all species. Whereas previous solid-state 13C data were diagnostic primarily at the family level, the patterns of 1D and 2D peaks may provide diagnostic information at the genus and species levels. These spectra constitute the first broad use of 1H NMR to study plant exudates in general and to provide taxonomic characterization in particular.

  9. ZERO-FIELD NUCLEAR MAGNETIC RESONANCE FOR STUDY OF ANTIFERROMAGNETIC PROPERTIES OF FeF3 MATERIALS

    Directory of Open Access Journals (Sweden)

    G. R. F. Suwandi

    2016-01-01

    Full Text Available Nuclear Magnetic Resonance (NMR has been used as a research tool in many fields. In this study, the magnetic properties, especially anti-ferromagnetic properties of FeF3 materials were investigated. Zero-field custom-built NMR method was used to investigate the anti-ferromagnetic properties in the materials. Experiments have been carried out by varying the sample temperatures from 8 K to 220 K. Ordinary spin echo pulse sequence 90⁰RF–τ–180⁰RF were used. Using Fast Fourier Transform, the signals in NMR spectrum were analyzed and the peak showed the resonance frequency. The result showed that resonance frequencies decrease with increasing in temperature. The frequency of the spectrum was around 85.41 MHz in the zero-temperature limit, and this corresponds with Fe hyperfine field at zero-temperature limit was 2.14 T. The temperature dependence of the local magnetization does not fit T2 Bloch’s Law very well. Instead, it fits the exponential form having an energy gap in the dispersion relation of the spin wave. It is obtained from the result that FeF3 is antiferromagnetic materials with energy gap of 11.466 meV and anisotropy energy of 1.045 meV.Nuclear Magnetic Resonance (NMR telah banyak digunakan sebagai “research tool” pada berbagai bidang kajian di fisika. Pada studi ini, akan dilakukan eksperimen untuk menguji sifat magnetik, khususnya antiferromagnetik pada material FeF3. Telah dilakukan eksperimen dengan memvariasikan temperatur pada sampel dari 8 K hingga 220 K. Pulse sequence yang digunakan adalah 90⁰RF–τ–180⁰RF. Dengan memanfaatkan Fast Fourier Transform, sinyal echo ini dapat dianalisis dalam bentuk spektrum NMR dengan puncak spektrum menunjukkan frekuensi resonansinya. Diperoleh bahwa frekuensi resonansi akan menurun seiring dengan kenaikan temperatur. Posisi frekuensi pada temperatur 0 K adalah sebesar 85,41 MHz, hal ini memperlihatkan bahwa medan hyperfine dari Fe sebesar 2,14 T pada temperatur 0 K. Kurva

  10. Combined passive acoustic mapping and magnetic resonance thermometry for monitoring phase-shift nanoemulsion enhanced focused ultrasound therapy

    Science.gov (United States)

    Crake, Calum; Meral, F. Can; Burgess, Mark T.; Papademetriou, Iason T.; McDannold, Nathan J.; Porter, Tyrone M.

    2017-08-01

    Focused ultrasound (FUS) has the potential to enable precise, image-guided noninvasive surgery for the treatment of cancer in which tumors are identified and destroyed in a single integrated procedure. However, success of the method in highly vascular organs has been limited due to heat losses to perfusion, requiring development of techniques to locally enhance energy absorption and heating. In addition, FUS procedures are conventionally monitored using MRI, which provides excellent anatomical images and can map temperature, but is not capable of capturing the full gamut of available data such as the acoustic emissions generated during this inherently acoustically-driven procedure. Here, we employed phase-shift nanoemulsions (PSNE) embedded in tissue phantoms to promote cavitation and hence temperature rise induced by FUS. In addition, we incorporated passive acoustic mapping (PAM) alongside simultaneous MR thermometry in order to visualize both acoustic emissions and temperature rise, within the bore of a full scale clinical MRI scanner. Focal cavitation of PSNE could be resolved using PAM and resulted in accelerated heating and increased the maximum elevated temperature measured via MR thermometry compared to experiments without nanoemulsions. Over time, the simultaneously acquired acoustic and temperature maps show translation of the focus of activity towards the FUS transducer, and the magnitude of the increase in cavitation and focal shift both increased with nanoemulsion concentration. PAM results were well correlated with MRI thermometry and demonstrated greater sensitivity, with the ability to detect cavitation before enhanced heating was observed. The results suggest that PSNE could be beneficial for enhancement of thermal focused ultrasound therapies and that PAM could be a critical tool for monitoring this process.

  11. Combined passive acoustic mapping and magnetic resonance thermometry for monitoring phase-shift nanoemulsion enhanced focused ultrasound therapy.

    Science.gov (United States)

    Crake, Calum; Meral, F Can; Burgess, Mark T; Papademetriou, Iason T; McDannold, Nathan J; Porter, Tyrone M

    2017-07-13

    Focused ultrasound (FUS) has the potential to enable precise, image-guided noninvasive surgery for the treatment of cancer in which tumors are identified and destroyed in a single integrated procedure. However, success of the method in highly vascular organs has been limited due to heat losses to perfusion, requiring development of techniques to locally enhance energy absorption and heating. In addition, FUS procedures are conventionally monitored using MRI, which provides excellent anatomical images and can map temperature, but is not capable of capturing the full gamut of available data such as the acoustic emissions generated during this inherently acoustically-driven procedure. Here, we employed phase-shift nanoemulsions (PSNE) embedded in tissue phantoms to promote cavitation and hence temperature rise induced by FUS. In addition, we incorporated passive acoustic mapping (PAM) alongside simultaneous MR thermometry in order to visualize both acoustic emissions and temperature rise, within the bore of a full scale clinical MRI scanner. Focal cavitation of PSNE could be resolved using PAM and resulted in accelerated heating and increased the maximum elevated temperature measured via MR thermometry compared to experiments without nanoemulsions. Over time, the simultaneously acquired acoustic and temperature maps show translation of the focus of activity towards the FUS transducer, and the magnitude of the increase in cavitation and focal shift both increased with nanoemulsion concentration. PAM results were well correlated with MRI thermometry and demonstrated greater sensitivity, with the ability to detect cavitation before enhanced heating was observed. The results suggest that PSNE could be beneficial for enhancement of thermal focused ultrasound therapies and that PAM could be a critical tool for monitoring this process.

  12. Chromatographic and spectroscopic analysis of heavy crude oil mixtures with emphasis in nuclear magnetic resonance spectroscopy: A review

    International Nuclear Information System (INIS)

    Silva, Sandra L.; Silva, Artur M.S.; Ribeiro, Jorge C.; Martins, Fernando G.; Da Silva, Francisco A.; Silva, Carlos M.

    2011-01-01

    Graphical abstract: The chromatographic and spectroscopic techniques used to characterize heavy crude oils, although more focused in the nuclear magnetic resonance spectroscopy as the technique of choice, due to its capability to provide great information on the chemical nature of individual types of proton and carbon atoms in different and complex mixtures of crude oils are described. This review is based on 65 references and describes in a critical and interpretative ways the advantages of the NMR spectroscopy as a main technique to be used in crude oil refining industries that want to characterize crude oil fractions and the obtained refined products. Highlights: ► Chromatogrfaphic and spectroscopic techniques used to characterize heavy crude oils have been reviewed. ► This review describes in a critical and interpretative ways the advantages of the NMR spectroscopy as a main technique to be used in crude oil refining industries. ► The progress in the interpretation of the NMR spectra and of different multivariate data analyses and their potential in the identification and characterization of hydrocarbons and their physical and chemical properties have also been reviewed. - Abstract: The state of the art in the characterization of heavy crude oil mixtures is presented. This characterization can be done by different techniques, such as gas chromatography (GC), high performance liquid chromatography (HPLC), thin layer chromatography (TLC), infrared spectroscopy (IR), Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Nuclear magnetic resonance spectroscopy is the technique of choice due to its capability to provide information on the chemical nature of individual types of hydrogen and carbon atoms in different and complex mixtures of crude oils. The progress made in the interpretation of the NMR spectra with the development of new NMR techniques and different multivariate data analyses could give relevant

  13. 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.

  14. Nuclear magnetic resonance and electrical conductivity measurements of diffusion and disorder in LiBr

    International Nuclear Information System (INIS)

    Hamann, H.; Reininghaus, J.; Richtering, H.

    1980-01-01

    Electrical conductivity and nuclear magnetic relaxation rates were measured with pure and doped LiBr between 400 K and the melting point (824 K). Prevalent intrinsic disorder was observed down to 470 K. The degree of thermal disorder is 5 X 10 -7 at 470 K and 5 X 10 -3 at the melting point. From the relaxation rates of 7 Li, which are caused by Li-diffusion and nuclear dipole interaction, mean jump frequencies of the cations are derived. Conductivities calculated from these frequencies for a jump process via neighbouring cation vacancies are in perfect agreement with directly measured conductivities. From relaxation rates of 81 Br with MgBr 2 -doped crystals jump frequencies of vacancies were obtained which are again in good agreement with those derived from the conductivity data. From motional narrowing of the 81 Br absorption line the jump frequency of the anions is obtained, which is much smaller than for the cations. Since this motional narrowing is not influenced by any doping, it is concluded that anion transport mainly occurs via pairs of cation and anion vacancies. (Auth.)

  15. Third-generation site characterization: Cryogenic core collection, nuclear magnetic resonance, and electrical resistivity

    Science.gov (United States)

    Kiaalhosseini, Saeed

    In modern contaminant hydrology, management of contaminated sites requires a holistic characterization of subsurface conditions. Delineation of contaminant distribution in all phases (i.e., aqueous, non-aqueous liquid, sorbed, and gas), as well as associated biogeochemical processes in a complex heterogeneous subsurface, is central to selecting effective remedies. Arguably, a factor contributing to the lack of success of managing contaminated sites effectively has been the limitations of site characterization methods that rely on monitoring wells and grab sediment samples. The overarching objective of this research is to advance a set of third-generation (3G) site characterization methods to overcome shortcomings of current site characterization techniques. 3G methods include 1) cryogenic core collection (C3) from unconsolidated geological subsurface to improve recovery of sediments and preserving key attributes, 2) high-throughput analysis (HTA) of frozen core in the laboratory to provide high-resolution, depth discrete data of subsurface conditions and processes, 3) resolution of non-aqueous phase liquid (NAPL) distribution within the porous media using a nuclear magnetic resonance (NMR) method, and 4) application of a complex resistivity method to track NAPL depletion in shallow geological formation over time. A series of controlled experiments were conducted to develop the C 3 tools and methods. The critical aspects of C3 are downhole circulation of liquid nitrogen via a cooling system, the strategic use of thermal insulation to focus cooling into the core, and the use of back pressure to optimize cooling. The C3 methods were applied at two contaminated sites: 1) F.E. Warren (FEW) Air Force Base near Cheyenne, WY and 2) a former refinery in the western U.S. The results indicated that the rate of core collection using the C3 methods is on the order of 30 foot/day. The C3 methods also improve core recovery and limits potential biases associated with flowing sands

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

    Directory of Open Access Journals (Sweden)

    Chuanjiang Li

    2014-01-01

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

  17. Prototype acoustic resonance spectroscopy monitor

    International Nuclear Information System (INIS)

    Sinha, D.N.; Olinger, C.T.

    1996-03-01

    This report reports on work performed for the International Atomic Energy Agency (IAEA) through the Program Office for Technical Assistance (POTAS). In this work, we investigate possible applications of nondestructive acoustics measurements to facilitate IAEA safeguards at bulk processing facilities. Two different acoustic techniques for verifying the internal structure of a processing tank were investigated. During this effort we also examined two acoustic techniques for assessing the fill level within a processing tank. The fill-level measurements could be made highly portable and have an added safeguards advantage that they can also detect stratification of fill material. This later application may be particularly useful in confirming the absence of stratification in plutonium processing tanks before accountability samples are withdrawn

  18. Restricted lithium ion dynamics in PEO-based block copolymer electrolytes measured by high-field nuclear magnetic resonance relaxation

    Science.gov (United States)

    Huynh, Tan Vu; Messinger, Robert J.; Sarou-Kanian, Vincent; Fayon, Franck; Bouchet, Renaud; Deschamps, Michaël

    2017-10-01

    The intrinsic ionic conductivity of polyethylene oxide (PEO)-based block copolymer electrolytes is often assumed to be identical to the conductivity of the PEO homopolymer. Here, we use high-field 7Li nuclear magnetic resonance (NMR) relaxation and pulsed-field-gradient (PFG) NMR diffusion measurements to probe lithium ion dynamics over nanosecond and millisecond time scales in PEO and polystyrene (PS)-b-PEO-b-PS electrolytes containing the lithium salt LiTFSI. Variable-temperature longitudinal (T1) and transverse (T2) 7Li NMR relaxation rates were acquired at three magnetic field strengths and quantitatively analyzed for the first time at such fields, enabling us to distinguish two characteristic time scales that describe fluctuations of the 7Li nuclear electric quadrupolar interaction. Fast lithium motions [up to O (ns)] are essentially identical between the two polymer electrolytes, including sub-nanosecond vibrations and local fluctuations of the coordination polyhedra between lithium and nearby oxygen atoms. However, lithium dynamics over longer time scales [O (10 ns) and greater] are slower in the block copolymer compared to the homopolymer, as manifested experimentally by their different transverse 7Li NMR relaxation rates. Restricted dynamics and altered thermodynamic behavior of PEO chains anchored near PS domains likely explain these results.

  19. Three dimensional gel dosimetry by use of nuclear magnetic resonance imaging (MRI)

    Energy Technology Data Exchange (ETDEWEB)

    De Deene, Y.; De Wagter, C.; Van Duyse, B.; Achten, E.; De Neve, W. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; De Poorter, J. [Ghent Univ. (Belgium). Dept. of Magnetic Resonance

    1995-12-01

    As co-monomers are found to polymerize by radiation, they are eligible for constructing a three dimensional dosimeter. Another kind of three dimensional dosimeter, based on the radiation sensitivity of the ferrous ions in a Fricke solution, was tested in a previous study. However, a major problem that occurs in this kind of gel dosimeters is the diffusion of the ferric and ferrous ions. The co-monomer gels are more stable. The degree of polymerisation is visualized with a clinical MRI system. Acrylamide and N,N-methylene-bis-acrylamide are dissolved in a gel composed of gelatin and water. By irradiation the co-monomers are polymerized to polyacrylamide. The gel is casted in humanoid forms. As such, a simulation of the irradiation of the patient can be performed. Magnetic resonance relaxivity images of the irradiated gel display the irradiation dose. The images of the gel are fused with the radiological images of the patient. Quantitation of the dose response of the co-monomer gel is obtained through calibration by test tubes.

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

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  1. In situ nuclear magnetic resonance response of permafrost and active layer soil in boreal and tundra ecosystems

    Science.gov (United States)

    Kass, M. Andy; Irons, Trevor P.; Minsley, Burke J.; Pastick, Neal J.; Brown, Dana R. N.; Wylie, Bruce K.

    2017-12-01

    Characterization of permafrost, particularly warm and near-surface permafrost which can contain significant liquid water, is critical to understanding complex interrelationships with climate change, ecosystems, and disturbances such as wildfires. Understanding the vulnerability and resilience of permafrost requires an interdisciplinary approach, relying on (for example) geophysical investigations, ecological characterization, direct observations, remote sensing, and more. As part of a multiyear investigation into the impacts of wildfires on permafrost, we have collected in situ measurements of the nuclear magnetic resonance (NMR) response of the active layer and permafrost in a variety of soil conditions, types, and saturations. In this paper, we summarize the NMR data and present quantitative relationships between active layer and permafrost liquid water content and pore sizes and show the efficacy of borehole NMR (bNMR) to permafrost studies. Through statistical analyses and synthetic freezing simulations, we also demonstrate that borehole NMR is sensitive to the nucleation of ice within soil pore spaces.

  2. Selective carbon 13 enrichment of side chain carbons of ginkgo lignin traced by carbon 13 nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Y. (Nagoya Univ. (Japan). Faculty of Agriculture); Robert, D.R. (CEA Centre d' Etudes de Grenoble, 38 (France). Dept. de Recherche Fondamentale sur la Matiere Condensee); Terashima, N. (Forest Products Lab., Madison, WI (United States))

    Although carbon 13 nuclear magnetic resonance spectroscopy ([sup 13]C-NMR) is widely used in lignin structural studies, serious difficulties are encountered in the assignments of [sup 13]C signals because of their extensive overlaps resulting from the complex structure of lignin and of delicate detection of minor structures. To overcome these difficulties, specifically [sup 13]C-enriched precursors of lignin biosynthesis, coniferin-[side chain-[beta]-[sup 13]C] and coniferin-[side chain-[gamma]-[sup 13]C], were administered to growing stems of ginkgo (Ginkgo biloba). The NMR analysis of the milled wood lignins isolated from the newly formed xylem showed that selective enrichment of specific carbons of protolignin in the cell wall was achieved without seriously disturbing the lignin biosynthesis. The presence of saturated methylene side chains in the protolignin was shown for the first time by this selective enrichment technique in combination with NMR analysis. (authors). 23 refs., 3 figs., 1 tab.

  3. Characterization of moisture in acetylated and propionylated radiata pine using low-field nuclear magnetic resonance (LFNMR) relaxometry

    DEFF Research Database (Denmark)

    Beck, Greeley; Thybring, Emil Engelund; Thygesen, Lisbeth Garbrecht

    2018-01-01

    Moisture in radiata pine (Pinus radiata D. Don) earlywood (EW), which was acetylated or propionylated to various degrees, was measured by low-field nuclear magnetic resonance (LFNMR) relaxometry. Spin-spin relaxation times (T2) were determined for fully saturated samples at 22 and -18°C. T2 values...... for EW lumen water increased with increasing acetylation weight percentage gain (WPG), perhaps caused by the less hydrophilic acetylated wood (AcW) surface. Cell wall water (WCW) and the water in pits and small voids also showed increasing T2 values as a function of WPG but with a weaker tendency....... A possible explanation is the counteracting effects of decreased hydrophilicity and reduced moisture content (MC) of these water populations at higher levels of acetylation. The evaluation of propionylation on WCW T2 data was complicated by peak splitting in the relaxation spectrum. Constant T2 values...

  4. In situ nuclear magnetic resonance response of permafrost and active layer soil in boreal and tundra ecosystems

    Directory of Open Access Journals (Sweden)

    M. A. Kass

    2017-12-01

    Full Text Available Characterization of permafrost, particularly warm and near-surface permafrost which can contain significant liquid water, is critical to understanding complex interrelationships with climate change, ecosystems, and disturbances such as wildfires. Understanding the vulnerability and resilience of permafrost requires an interdisciplinary approach, relying on (for example geophysical investigations, ecological characterization, direct observations, remote sensing, and more. As part of a multiyear investigation into the impacts of wildfires on permafrost, we have collected in situ measurements of the nuclear magnetic resonance (NMR response of the active layer and permafrost in a variety of soil conditions, types, and saturations. In this paper, we summarize the NMR data and present quantitative relationships between active layer and permafrost liquid water content and pore sizes and show the efficacy of borehole NMR (bNMR to permafrost studies. Through statistical analyses and synthetic freezing simulations, we also demonstrate that borehole NMR is sensitive to the nucleation of ice within soil pore spaces.

  5. Roasting process of coffee beans as studied by nuclear magnetic resonance: time course of changes in composition.

    Science.gov (United States)

    Wei, Feifei; Furihata, Kazuo; Koda, Masanori; Hu, Fangyu; Miyakawa, Takuya; Tanokura, Masaru

    2012-02-01

    In this paper, we report a (1)H and (13)C nuclear magnetic resonance (NMR)-based comprehensive analysis of coffee bean extracts of different degrees of roast. The roasting process of coffee bean extracts was chemically characterized using detailed signal assignment information coupled with multivariate data analysis. A total of 30 NMR-visible components of coffee bean extracts were monitored simultaneously as a function of the roasting duration. During roasting, components such as sucrose and chlorogenic acids were degraded and components such as quinic acids, N-methylpyridinium, and water-soluble polysaccharides were formed. Caffeine and myo-inositol were relatively thermally stable. Multivariate data analysis indicated that some components such as sucrose, chlorogenic acids, quinic acids, and polysaccharides could serve as chemical markers during coffee bean roasting. The present composition-based quality analysis provides an excellent holistic method and suggests useful chemical markers to control and characterize the coffee-roasting process.

  6. In situ nuclear magnetic resonance response of permafrost and active layer soil in boreal and tundra ecosystems

    Science.gov (United States)

    Kass, Mason A.; Irons, Trevor P; Minsley, Burke J.; Pastick, Neal J.; Brown, Dana R N; Wylie, Bruce K.

    2017-01-01

    Characterization of permafrost, particularly warm and near-surface permafrost which can contain significant liquid water, is critical to understanding complex interrelationships with climate change, ecosystems, and disturbances such as wildfires. Understanding the vulnerability and resilience of permafrost requires an interdisciplinary approach, relying on (for example) geophysical investigations, ecological characterization, direct observations, remote sensing, and more. As part of a multi-year investigation into the impacts of wildfires to permafrost, we have collected in situ measurements of the nuclear magnetic resonance (NMR) response of active layer and permafrost in a variety of soil conditions, types, and saturations. In this paper, we summarize the NMR data and present quantitative relationships between active layer and permafrost liquid water content and pore sizes. Through statistical analyses and synthetic freezing simulations, we also demonstrate that borehole NMR can image the nucleation of ice within soil pore spaces.

  7. Nuclear Magnetic Resonance Spectroscopy Investigations of Naphthalene-Based 1,2,3-Triazole Systems for Anion Sensing

    Directory of Open Access Journals (Sweden)

    Karelle Aiken

    2018-02-01

    Full Text Available Detailed Nuclear Magnetic Resonance (NMR spectroscopy investigations on a novel naphthalene-substituted 1,2,3-triazole-based fluorescence sensor provided evidence for the “turn-on” detection of anions. The one-step, facile synthesis of the sensors was implemented using the “Click chemistry” approach in good yield. When investigated for selectivity and sensitivity against a series of anions (F−, Cl−, Br−, I−, H2PO4−, ClO4−, OAc−, and BF4−, the sensor displayed the strongest fluorometric response for the fluoride anion. NMR and fluorescence spectroscopic studies validate a 1:1 binding stoichiometry between the sensor and the fluoride anion. Single crystal X-ray diffraction evidence revealed the structure of the sensor in the solid state.

  8. 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).

  9. A carbon-13 and proton nuclear magnetic resonance study of some experimental referee broadened-specification /ERBS/ turbine fuels

    Science.gov (United States)

    Dalling, D. K.; Pugmire, R. J.

    1982-01-01

    Preliminary results of a nuclear magnetic resonance (NMR) spectroscopy study of alternative jet fuels are presented. A referee broadened-specification (ERBS) aviation turbine fuel, a mixture of 65 percent traditional kerosene with 35 percent hydrotreated catalytic gas oil (HCGO) containing 12.8 percent hydrogen, and fuels of lower hydrogen content created by blending the latter with a mixture of HCGO and xylene bottoms were studied. The various samples were examined by carbon-13 and proton NMR at high field strength, and the resulting spectra are shown. In the proton spectrum of the 12.8 percent hydrogen fuel, no prominent single species is seen while for the blending stock, many individual lines are apparent. The ERBS fuels were fractionated by high-performance liquid chromatography and the resulting fractions analyzed by NMR. The species found are identified.

  10. Pattern recognition analysis of proton nuclear magnetic resonance spectra of brain tissue extracts from rats anesthetized with propofol or isoflurane.

    Directory of Open Access Journals (Sweden)

    Hiroshi Kawaguchi

    Full Text Available BACKGROUND: General anesthesia is routinely used as a surgical procedure and its safety has been endorsed by clinical outcomes; however, its effects at the molecular level have not been elucidated. General anesthetics influence glucose metabolism in the brain. However, the effects of anesthetics on brain metabolites other than those related to glucose have not been well characterized. We used a pattern recognition analysis of proton nuclear magnetic resonance spectra to visualize the changes in holistic brain metabolic phenotypes in response to the widely used intravenous anesthetic propofol and the volatile anesthetic isoflurane. METHODOLOGY/PRINCIPAL FINDINGS: Rats were randomized into five groups (n = 7 each group. Propofol and isoflurane were administered to two groups each, for 2 or 6 h. The control group received no anesthesia. Brains were removed directly after anesthesia. Hydrophilic compounds were extracted from excised whole brains and measured by proton nuclear magnetic resonance spectroscopy. All spectral data were processed and analyzed by principal component analysis for comparison of the metabolite profiles. Data were visualized by plotting principal component (PC scores. In the plots, each point represents an individual sample. The propofol and isoflurane groups were clustered separately on the plots, and this separation was especially pronounced when comparing the 6-h groups. The PC scores of the propofol group were clearly distinct from those of the control group, particularly in the 6-h group, whereas the difference in PC scores was more subtle in the isoflurane group and control groups. CONCLUSIONS/SIGNIFICANCE: The results of the present study showed that propofol and isoflurane exerted differential effects on holistic brain metabolism under anesthesia.

  11. (1)H-Nuclear magnetic resonance-based plasma metabolic profiling of dairy cows with clinical and subclinical ketosis.

    Science.gov (United States)

    Sun, L W; Zhang, H Y; Wu, L; Shu, S; Xia, C; Xu, C; Zheng, J S

    2014-03-01

    The purpose of this study was to assess the metabolic profile of plasma samples from cows with clinical and subclinical ketosis. According to clinical signs and 3-hydroxybutyrate plasma levels, 81 multiparous Holstein cows were selected from a dairy farm 7 to 21 d after calving. The cows were divided into 3 groups: cows with clinical ketosis, cows with subclinical ketosis, and healthy control cows. (1)H-Nuclear magnetic resonance-based metabolomics was used to assess the plasma metabolic profiles of the 3 groups. The data were analyzed by principal component analysis, partial least squares discriminant analysis, and orthogonal partial least-squares discriminant analysis. The differences in metabolites among the 3 groups were assessed. The orthogonal partial least-squares discriminant analysis model differentiated the 3 groups of plasma samples. The model predicted clinical ketosis with a sensitivity of 100% and a specificity of 100%. In the case of subclinical ketosis, the model had a sensitivity of 97.0% and specificity of 95.7%. Twenty-five metabolites, including acetoacetate, acetone, lactate, glucose, choline, glutamic acid, and glutamine, were different among the 3 groups. Among the 25 metabolites, 4 were upregulated, 7 were downregulated, and 14 were both upregulated and downregulated. The results indicated that plasma (1)H-nuclear magnetic resonance-based metabolomics, coupled with pattern recognition analytical methods, not only has the sensitivity and specificity to distinguish cows with clinical and subclinical ketosis from healthy controls, but also has the potential to be developed into a clinically useful diagnostic tool that could contribute to a further understanding of the disease mechanisms. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Functional Magnetic Resonance Imaging

    Science.gov (United States)

    Voos, Avery; Pelphrey, Kevin

    2013-01-01

    Functional magnetic resonance imaging (fMRI), with its excellent spatial resolution and ability to visualize networks of neuroanatomical structures involved in complex information processing, has become the dominant technique for the study of brain function and its development. The accessibility of in-vivo pediatric brain-imaging techniques…

  13. Magnetic Resonance Imaging (MRI)

    Science.gov (United States)

    ... UltrasoundCT Head ScanElectrocardiogram (EKG or ECG)Pap Smear (Pap Test) Home Tests and Procedures Magnetic Resonance Imaging (MRI) ... SafetyRead Article >>Imaging and Medical Radiation SafetyPap Smear (Pap Test)Read Article >>Pap Smear (Pap Test)Preconception Carrier ...

  14. Properties of K,Rb-intercalated C60 encapsulated inside carbon nanotubes called peapods derived from nuclear magnetic resonance

    KAUST Repository

    Mahfouz, Remi

    2015-09-18

    We present a detailed experimental study on how magnetic and electronic properties of Rb,K-intercalated C60 encapsulated inside carbon nanotubes called peapods can be derived from 13C nuclear magnetic resonance investigations. Ring currents do play a basic role in those systems; in particular, the inner cavities of nanotubes offer an ideal environment to investigate the magnetism at the nanoscale. We report the largest diamagnetic shifts down to −68.3 ppm ever observed in carbon allotropes, which is connected to the enhancement of the aromaticity of the nanotube envelope upon intercalation. The metallization of intercalated peapods is evidenced from the chemical shift anisotropy and spin-lattice relaxation (T1) measurements. The observed relaxation curves signal a three-component model with two slow and one fast relaxing components. We assigned the fast component to the unpaired electrons charged C60 that show a phase transition near 100 K. The two slow components can be rationalized by the two types of charged C60 at two different positions with a linear regime following Korringa behavior, which is typical for metallic system and allow us to estimate the density of sate at Fermi level n(EF).

  15. Structural analysis of mixed alkali borosilicate glasses containing Cs+ and Na+ using strong magnetic field magic angle spinning nuclear magnetic resonance

    Directory of Open Access Journals (Sweden)

    S. Kaneko

    2017-03-01

    Full Text Available We have investigated the local structure of alkali atoms in mixed alkali silicate, borate, and borosilicate glasses, which contain Cs+ and Na+, using strong magnetic field magic angle spinning nuclear magnetic resonance (MAS NMR spectroscopy of 133Cs and 23Na. The spectral peaks of 133Cs in borosilicate (Si:B = 1:1 and Si-rich borosilicate (Si:B = 2:1 glasses shifted to upfield with increasing Cs+/(Na+ + Cs+ ratio, which implies that the coordination number of Cs+ decreased as in the case of silicate and borate glasses. However, this trend was not observed in the 23Na spectra of either borosilicate glass. This might be because the chemical shift of 23Na in borosilicate glass is strongly affected by nearby species such as Si or B, and not by the coordination number of Na+.

  16. A monitoring of superconducting magnets by acoustic emission

    International Nuclear Information System (INIS)

    Nomura, Harehiko; Tateishi, Hiroshi; Onishi, Toshitada

    1990-01-01

    Since superconducting magnets (SCM) are going to be indispensable to magnetic levitated train, nuclear fusion, magnetic resonating imaging, rotational machines, etc., they must be placed great reliance on its repetitional operations. But without appropriate evaluating methods, these promising techniques must remain still in science levels and hard to be transferable to real human technologies. SCM, being used under dynamical operation with linking other electro-magnetic systems as said above, induce high voltage from which monitoring superconducting to normal transitional voltage is difficult to distinguish. To solve this problem, monitoring SCM by Acoustic Emission (AE) from themselves, have been found effective, in particular, during the dynamical energizing of them. As for a demonstration, this paper will report mainly how to monitor 3 MJ-SCM and a few results of the experiments aquired both by counting and locational mode of AE in pulsed and repeated operations of the magnet. Some discussions on the AE monitorings are also made along the main issues to be solved in future. (author)

  17. The nuclear magnetic resonance in endocrinology. Spectroscopy and imaging, present and future. La Resonance Magnetique Nucleaire en Endocrinologie. Spectroscopie et Imagerie, present et avenir

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, M.; Zanca, M. (Hopital Lapeyronie, 34 - Montpellier (FR))

    1990-01-01

    The first part, after a brief historical reminder, gives an oversimplified and non rigorous approach to the Nuclear Magnetic Resonance (NMR) phenomenon; this physical introduction leads the clinician to know the essential about the spectral and imaging techniques in NMR, just to understand what is done... The second part of this paper shows some medical applications of these two aspects of NMR, with help of some examples, taken from the literature, according to what is concerned with endocrinology. Pure bio chemical applications (enzymology), or those concerning isolated (and perfused) organs, or living animals, and even human beings, are numerous and complementary, and there is no doubt that the applications of NMR technologies to medicine will know a promising future.

  18. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... Computed Tomography) Magnetic Resonance Imaging (MRI) Safety Contrast Materials Children and Radiation Safety Videos related to Children’s (Pediatric) Magnetic Resonance Imaging Sponsored by Please note RadiologyInfo.org ...

  19. Magnetic Resonance Imaging of Stroke

    NARCIS (Netherlands)

    Bouts, Mark. J. R. J.; Wu, O.; Dijkhuizen, R. M.

    2017-01-01

    Magnetic resonance imaging (MRI) provides a powerful (neuro)imaging modality for the diagnosis and outcome prediction after (acute) stroke. Since MRI allows noninvasive, longitudinal, and three-dimensional assessment of vessel occlusion (with magnetic resonance angiography (MRA)), tissue injury

  20. Children's (Pediatric) Magnetic Resonance Imaging

    Medline Plus

    Full Text Available ... the same effect. A very irregular heartbeat may affect the quality of images obtained using techniques that ... and Media Catheter Angiography Magnetic Resonance, Functional (fMRI) - Brain Children's (Pediatric) CT (Computed Tomography) Magnetic Resonance Imaging ( ...

  1. Magnetic Resonance Imaging (MRI) -- Head

    Medline Plus

    Full Text Available ... ports artificial limbs or metallic joint prostheses implanted nerve stimulators metal pins, screws, plates, stents or surgical ... Magnetic Resonance Imaging (MRI) Safety Alzheimer's Disease Head Injury Brain Tumors Images related to Magnetic Resonance Imaging ( ...

  2. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... for Brain Tumors Radiation Therapy for Head and Neck Cancer Others : American Stroke Association National Stroke Association ... MRA) Magnetic Resonance, Functional (fMRI) - Brain Head and Neck Cancer Treatment Brain Tumor Treatment Magnetic Resonance Imaging ( ...

  3. Comparison between Gradient Gel Electrophoresis and Nuclear Magnetic Resonance Spectroscopy in Estimating Coronary Heart Disease Risk Associated with LDL and HDL Particle Size

    NARCIS (Netherlands)

    Arsenault, Benoit J.; Lemieux, Isabelle; Després, Jean-Pierre; Wareham, Nicholas J.; Stroes, Erik S. G.; Kastelein, John J. P.; Khaw, Kay-Tee; Boekholdt, S. Matthijs

    2010-01-01

    BACKGROUND: Gradient gel electrophoresis (GGE) and nuclear magnetic resonance (NMR) spectroscopy are both widely accepted methods for measuring LDL and HDL particle size. However, whether or not GGE- or NMR-measured LDL or HDL particle size predicts coronary heart disease (CHD) risk to a similar

  4. In-Situ Nuclear Magnetic Resonance Investigation of Strain, Temperature, and Strain-Rate Variations of Deformation-Induced Vacancy Concentration in Aluminum

    NARCIS (Netherlands)

    Linga Murty, K.; Detemple, K.; Kanert, O.; Hosson, J.Th.M. De

    1998-01-01

    Critical strain to serrated flow in solid solution alloys exhibiting dynamic strain aging (DSA) or Portevin–LeChatelier effect is due to the strain-induced vacancy production. Nuclear magnetic resonance (NMR) techniques can be used to monitor in situ the dynamical behavior of point and line defects

  5. Effects of Cadmium(II) Ions on Early Somatic Embryos of Norway spruce Studied by Using Electrochemical Techniques and Nuclear Magnetic Resonance

    Czech Academy of Sciences Publication Activity Database

    Húska, D.; Zítka, O.; Kryštofová, O.; Adam, V.; Babula, P.; Zehnálek, J.; Bartušek, Karel; Beklová, M.; Havel, L.; Kizek, R.

    2010-01-01

    Roč. 5, č. 11 (2010), s. 1535-1549 ISSN 1452-3981 Institutional research plan: CEZ:AV0Z20650511 Keywords : plant * Norway spruce * somatic embryos * water * thiol * nuclear magnetic resonance * voltammetry Subject RIV: GF - Plant Pathology, Vermin, Weed, Plant Protection Impact factor: 2.808, year: 2010

  6. Nuclear magnetic resonance imaging in studies of gravitropism in soil mixtures.

    Science.gov (United States)

    Antonsen, F; Johnsson, A; Futsaether, C; Krane, J

    1999-04-01

    Gravitropic responses of oat coleoptiles were measured in different growth media; humid air, natural soil and artificial soil (glass beads). The oat coleoptiles in soil and glass beads were monitored by NMR imaging, while those in humid air were imaged in darkness with an infrared-sensitive charge-coupled device (CCD) camera. The present study shows for the first time that gravitropic experiments can be performed in artificial soil using NMR imaging as a convenient and suitable recording method. Not only was it possible to follow the gravitropic curvatures in natural soil, but the artificial soil allowed plant images of sufficient spatial and temporal resolution to be recorded. The advantages of using artificial soil in magnetic resonance imaging studies are that the iron content of glass beads is very low compared with natural soil, and that the artificial soil matrix can easily, be standardized with regard to particle size distribution and nutrient content. Two types of glass beads were used, the diameter of the small and the large beads being 300-400 and 420-840 micrometers, respectively. The growth rate of the coleoptiles in soil and in big beads was roughly the same and only slightly lower than in humid air, whereas small beads reduced the growth rate by approx. 16%. The bending rate of the coleoptiles during the gravitropic response was reduced by c. 65% in soil and 75% in bead mixtures relative to bending in air. It should be noted, however, that the maximum curvature of the coleoptile tip was of the same order in all cases, about 35 degrees. This value may represent the largest possible curvature of the organ. The potential of NMR imaging to study, how plant organs penetrate the soil under the influence of gravitropism, mechanical impedance and thigmotropism is also discussed.

  7. Diffuse vascular damage in a transplanted kidney: an indication for nuclear magnetic resonance?

    Science.gov (United States)

    Burdese, M; Consiglio, V; Mezza, E; Savio, D; Guarena, C; Rossetti, M; Messina, M; Soragna, G; Suriani, C; Rabbia, C; Segoloni, G P; Piccoli, G B

    2005-06-01

    Vascular lesions are an increasing challenge after renal transplantation due to the wider indications for recipients and acceptance criteria for donors. Diagnostic approach and prognostic interpretation are still matter of controversy. The case reported herein may summarize some of the issues in this regard. A 54-year-old woman, on renal replacement therapy since 1974, and a kidney graft recipient from 1975 to 1999, received a second graft in 2001. The donor age was 65 years (cold ischemia 22 hours; two mismatches). The early posttransplant follow-up was characterized by delayed graft function, hypertension, and diabetes. During the initial hypertension workup, renal graft ultrasound (US) Doppler demonstrated increased vascular resistances, stable over time (resistance index 0.74 to 0.77); renal scintiscan displayed homogeneously parenchymoa and angio-magnetic resonance imaging (MRI), an homogeneous parenchymal vascularization. Initial immunosuppression with tacrolimus and steroids was modulated by adding mycophenolate mofetil to taper tacrolimus (to reduce nephrotoxicity and hypertension). Despite this, kidney function slowly deteriorated; serum creatinine reached 3 to 3.5 mg/dL by the second year. After a severe hypertensive crisis with unchanged scintiscan and US doppler examinations, angio-MRI revealed the almost complete disappearance of parenchymal enhancement beyond the lobar arteries. A renal biopsy confirmed the severe vascular damage. The patient was switched to rapamycine and a low-dose of an angiotension converting enzyme (ACE) inhibitor. She did relatively well (serum creatinine 2.2 to 3 mg/dL) for 6 months, when rapid functional impairment forced her to restart hemodialysis. This case, almost paradigmatic of the problems occurring when the rigid vasculature of long-term dialysis patients is matched with "marginal kidneys," suggests that MRI may be a sensible good to define vascular damage in the grafted kidney.

  8. Continuous-Wave Operation of a Frequency-Tunable 460-GHz Second-Harmonic Gyrotron for Enhanced Nuclear Magnetic Resonance

    Science.gov (United States)

    Torrezan, Antonio C.; Han, Seong-Tae; Mastovsky, Ivan; Shapiro, Michael A.; Sirigiri, Jagadishwar R.; Temkin, Richard J.; Griffin, Robert G.; Barnes, Alexander B.

    2012-01-01

    The design, operation, and characterization of a continuous-wave (CW) tunable second-harmonic 460-GHz gyrotron are reported. The gyrotron is intended to be used as a submillimeter-wave source for 700-MHz nuclear magnetic resonance experiments with sensitivity enhanced by dynamic nuclear polarization. The gyrotron operates in the whispering-gallery mode TE11,2 and has generated 16 W of output power with a 13-kV 100-mA electron beam. The start oscillation current measured over a range of magnetic field values is in good agreement with theoretical start currents obtained from linear theory for successive high-order axial modes TE11,2,q. The minimum start current is 27 mA. Power and frequency tuning measurements as a function of the electron cyclotron frequency have also been carried out. A smooth frequency tuning range of 1 GHz was obtained for the operating second-harmonic mode either by magnetic field tuning or beam voltage tuning. Long-term CW operation was evaluated during an uninterrupted period of 48 h, where the gyrotron output power and frequency were kept stable to within ±0.7% and ±6 ppm, respectively, by a computerized control system. Proper operation of an internal quasi-optical mode converter implemented to transform the operating whispering-gallery mode to a Gaussian-like beam was also verified. Based on the images of the gyrotron output beam taken with a pyroelectric camera, the Gaussian-like mode content of the output beam was computed to be 92% with an ellipticity of 12%. PMID:23761938

  9. First national meeting of magnetic resonance and hyperfine interactions

    International Nuclear Information System (INIS)

    1985-07-01

    Works performed at CNEA's: Magnetic Resonance Division; Moessbauer Spectroscopy; Solid State Physics Division; Nuclear magnetic Resonance Laboratory and Theoretical Physics Group; Mossbauer Spectroscopy Group; Nuclear Quadrupole Resonance; Physics and Materials Group; Perturbed Angular Correlation and Moessbauer Spectroscopy and Physics Department. (M.E.L.) [es

  10. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head uses a powerful ... Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is a noninvasive medical test that ...

  11. Magnetic Resonance Imaging (MRI) -- Head

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    Full Text Available ... News Physician Resources Professions Site Index A-Z Magnetic Resonance Imaging (MRI) - Head Magnetic resonance imaging (MRI) of the head ... limitations of MRI of the Head? What is MRI of the Head? Magnetic resonance imaging (MRI) is ...

  12. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) uses a powerful ... of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive medical ...

  13. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... News Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging ( ... the limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a ...

  14. Children's (Pediatric) Magnetic Resonance Imaging

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

  15. Children's (Pediatric) Magnetic Resonance Imaging

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    Full Text Available ... Physician Resources Professions Site Index A-Z Children’s (Pediatric) Magnetic Resonance Imaging Children’s magnetic resonance imaging (MRI) ... limitations of Children’s (Pediatric) MRI? What is Children’s (Pediatric) MRI? Magnetic resonance imaging (MRI) is a noninvasive ...

  16. Hyperfine field distribution in the Heusler compound Co2FeAl probed by 59Co nuclear magnetic resonance

    International Nuclear Information System (INIS)

    Wurmehl, Sabine; Kohlhepp, Juergen T; Swagten, Henk J M; Koopmans, Bert

    2008-01-01

    The Heusler compound Co 2 FeAl is reported to occur in various structures ranging from the completely ordered L2 1 to the completely disordered A2 structure type. In this work, we use spin echo nuclear magnetic resonance (NMR) to probe the local structure of Co 2 FeAl bulk samples. The study of Co 2 FeAl bulk samples provides the unique possibility to verify the intrinsic generic structural properties. The 59 Co NMR measurements reveal a distribution of Fe and Al not only in the first neighbouring shells of the 59 Co nuclei but also in more distant shells. The analysis of 59 Co NMR main resonance lines with an underlying sub-structure confirms that the local structure of the as-cast Co 2 FeAl bulk samples consists of a B2 type structure with contributions of the L2 1 type structure of about 10%. The observed sub-lines, which are attributed to a distribution of Fe and Al atoms in more distant shells, were previously not resolved in NMR spectra of Co 2 FeAl thin films, pointing to better long range order in bulk material than in thin films. We also show that the individual contributions of the structure types can be influenced by annealing

  17. Fourier Transform Mass Spectrometry and Nuclear Magnetic Resonance Analysis for the Rapid and Accurate Characterization of Hexacosanoylceramide.

    Science.gov (United States)

    Ross, Charles W; Simonsick, William J; Bogusky, Michael J; Celikay, Recep W; Guare, James P; Newton, Randall C

    2016-06-28

    Ceramides are a central unit of all sphingolipids which have been identified as sites of biological recognition on cellular membranes mediating cell growth and differentiation. Several glycosphingolipids have been isolated, displaying immunomodulatory and anti-tumor activities. These molecules have generated considerable interest as potential vaccine adjuvants in humans. Accurate analyses of these and related sphingosine analogues are important for the characterization of structure, biological function, and metabolism. We report the complementary use of direct laser desorption ionization (DLDI), sheath flow electrospray ionization (ESI) Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and high-field nuclear magnetic resonance (NMR) analysis for the rapid, accurate identification of hexacosanoylceramide and starting materials. DLDI does not require stringent sample preparation and yields representative ions. Sheath-flow ESI yields ions of the product and byproducts and was significantly better than monospray ESI due to improved compound solubility. Negative ion sheath flow ESI provided data of starting materials and products all in one acquisition as hexacosanoic acid does not ionize efficiently when ceramides are present. NMR provided characterization of these lipid molecules complementing the results obtained from MS analyses. NMR data was able to differentiate straight chain versus branched chain alkyl groups not easily obtained from mass spectrometry.

  18. Fourier Transform Mass Spectrometry and Nuclear Magnetic Resonance Analysis for the Rapid and Accurate Characterization of Hexacosanoylceramide

    Directory of Open Access Journals (Sweden)

    Charles W. Ross

    2016-06-01

    Full Text Available Ceramides are a central unit of all sphingolipids which have been identified as sites of biological recognition on cellular membranes mediating cell growth and differentiation. Several glycosphingolipids have been isolated, displaying immunomodulatory and anti-tumor activities. These molecules have generated considerable interest as potential vaccine adjuvants in humans. Accurate analyses of these and related sphingosine analogues are important for the characterization of structure, biological function, and metabolism. We report the complementary use of direct laser desorption ionization (DLDI, sheath flow electrospray ionization (ESI Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS and high-field nuclear magnetic resonance (NMR analysis for the rapid, accurate identification of hexacosanoylceramide and starting materials. DLDI does not require stringent sample preparation and yields representative ions. Sheath-flow ESI yields ions of the product and byproducts and was significantly better than monospray ESI due to improved compound solubility. Negative ion sheath flow ESI provided data of starting materials and products all in one acquisition as hexacosanoic acid does not ionize efficiently when ceramides are present. NMR provided characterization of these lipid molecules complementing the results obtained from MS analyses. NMR data was able to differentiate straight chain versus branched chain alkyl groups not easily obtained from mass spectrometry.

  19. A discussion about the potentials and pitfalls of quantitative nuclear magnetic resonance (qNMR) spectroscopy in food science and beyond

    OpenAIRE

    Lachenmeier, Dirk W.; Schönberger, Torsten; Ehni, Sebastian; Schütz, Birk; Spraul, Manfred

    2016-01-01

    During the XIII International Conference on the Applications of Magnetic Resonance in Food Science, which was held in Karlsruhe, Germany, from 7th to 10th of June 2016, a discussion session entitled “Quantitative nuclear magnetic resonance (qNMR)” was organized. The conference participants had the opportunity to submit written questions as well as to ask ad-hoc questions during the session, which were to be answered by a panel of qNMR experts from several application fields. This article prov...

  20. Local structures of mesoporous bioactive glasses and their surface alterations in vitro: inferences from solid-state nuclear magnetic resonance

    Science.gov (United States)

    Gunawidjaja, Philips N.; Mathew, Renny; Lo, Andy Y. H.; Izquierdo-Barba, Isabel; García, Ana; Arcos, Daniel; Mattias Edén, María Vallet-Regí

    2012-01-01

    We review the benefits of using 29Si and 1H magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy for probing the local structures of both bulk and surface portions of mesoporous bioactive glasses (MBGs) of the CaO–SiO2−(P2O5) system. These mesoporous materials exhibit an ordered pore arrangement, and are promising candidates for improved bone and tooth implants. We discuss experimental MAS NMR results from three MBGs displaying different Ca, Si and P contents: the 29Si NMR spectra were recorded either directly by employing radio-frequency pulses to 29Si, or by magnetization transfers from neighbouring protons using cross polarization, thereby providing quantitative information about the silicate speciation present in the pore wall and at the MBG surface, respectively. The surface modifications were monitored for the three MBGs during their immersion in a simulated body fluid (SBF) for intervals between 30 min and one week. The results were formulated as a reaction sequence describing the interconversions between the distinct silicate species. We generally observed a depletion of Ca2+ ions at the MBG surface, and a minor condensation of the silicate-surface network over one week of SBF soaking. PMID:22349247